WorldWideScience

Sample records for experimental functional neurosurgery

  1. Functional neurosurgery

    African Journals Online (AJOL)

    It is a great honour to write the editorial for this month's CME component of the SAMJ. Functional neurosurgery is a subdivision of neurosurgery that does not always receive the recognition we feel that it deserves among general medical practitioners. It is definitely the less 'sexy' component of neurosurgery compared with ...

  2. History of Chinese stereotactic and functional neurosurgery.

    Science.gov (United States)

    Sun, B; Lang, L Q; Cong, P Y; Liu, K Y; Pan, L

    2001-01-01

    Chinese stereotactic and functional neurosurgery started in 1963. Dr. Jian-Ping Xu did stereotactic surgery for Parkinson's disease with a small Cartesian coordinate stereotactic device which he designed. In 1983, the first Chinese Institute of Stereotactic and Functional Neurosurgery was established by Dr. Jian-Ping Xu and Dr. Ye-Han Wang in the Anhui Provincial Hospital in the city of Hefei. Since then, the Institute has hosted an annual National Workshop on Stereotactic and Functional Neurosurgery, where more than 80% of the functional neurosurgeons now practicing in China have been trained. In 1986, the Chinese Society of Stereotactic and Functional Neurosurgery was established, and the first issue of the Chinese Journal of Stereotactic and Functional Neurosurgery was published. With more than 35 years of development, stereotactic and functional neurosurgery has become a very important branch of surgery in China. More than 5,000 functional neurosurgery procedures and more than 8,000 stereotactic radiosurgery procedures are now performed annually. Copyright 2002 S. Karger AG, Basel

  3. Stereotactic imaging in functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Hirabayashi, Hidehiro

    2012-07-01

    Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. Initially, these procedures were largely based on the same imaging technique that had been used since the birth of this technique, and that is still used in some centers. The introduction of new imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided new potentials, but also new challenges for accurate identification and visualisation of the targets in the basal ganglia and the thalamus with an urge to thoroughly evaluate and optimize the stereotactic targeting technique, as well as evaluate accurately in stereotactic space the location and extent of stereotactic Radiofrequency (RF) lesions and the position of deep brain stimulation (DBS) electrodes. Aims: To study the differences between CT and MRI regarding indirect atlas coordinates in thalamic and pallidal procedures and to evaluate and validate visualisation of the pallidum and the subthalamic nucleus in view of direct targeting irrespective of atlas-derived coordinates. Furthermore, to evaluate the contribution of RF parameters on the size of stereotactic lesions, as well as the impact of size and location on clinical outcome. Method: The coordinates in relation to the landmarks of the 3{sup rd} ventricle of the targets in the pallidum and ventrolateral thalamus were compared between CT and MRI in 34 patients. In another 48 patients direct visualization of the pallidum was evaluated and compared to indirect atlas based targeting. The possibility and versatility of visualizing the Subthalamic Nucleus (STN) on short acquisition MRI were evaluated in a multicentre study, and the use of alternative landmarks in identification of the STN was demonstrated in another study. In 46 patients CT and

  4. Advances in functional neurosurgery for Parkinson's disease.

    Science.gov (United States)

    Metman, Leo Verhagen; Slavin, Konstantin V

    2015-09-15

    Functional neurosurgery for Parkinson's disease has become a mainstream concept with DBS as the prime modality. This article reviews the latest and, in the eyes of the authors, the most important developments in DBS, lesioning and gene therapy. In DBS, emerging advances have focused on the timing of surgery relative to disease duration and severity, and new targets, technologies, and equipment. For lesions, new ultrasound techniques are emerging based on successes in other movement disorders. Gene and cellular therapies, including stem cells, remain only in the research realm. © 2015 International Parkinson and Movement Disorder Society.

  5. Resurgence of functional neurosurgery for Parkinson's disease: a historical perspective

    NARCIS (Netherlands)

    Speelman, J. D.; Bosch, D. A.

    1998-01-01

    The history of functional neurosurgery for the treatment of Parkinson's disease is reviewed. Two major stages may be distinguished: (1) open functional neurosurgery, which started in 1921 with bilateral cervical rhizotomy by Leriche. In 1937 Bucy performed the first motor cortectomy in a tremor

  6. Minimizing brain shift in stereotactic functional neurosurgery.

    Science.gov (United States)

    Petersen, Erika A; Holl, Etienne M; Martinez-Torres, Irene; Foltynie, Thomas; Limousin, Patricia; Hariz, Marwan I; Zrinzo, Ludvic

    2010-09-01

    Stereotactic functional neurosurgical interventions depend on precise anatomic targeting before lesioning or deep brain stimulation (DBS) electrode placement. To examine the degree of subcortical brain shift observed when adopting an image-guided approach to stereotactic functional neurosurgery. Coordinates for the anterior and posterior commissural points (AC and PC) were recorded on thin-slice stereotactic magnetic resonance imaging (MRI) scans performed before and immediately after DBS electrode implantation in 136 procedures. The changes in length of AC-PC and in stereotactic coordinates for AC and PC were calculated for each intervention. In patients with Parkinson disease undergoing bilateral subthalamic nucleus (STN) DBS with at least 6 months of follow-up, pre- and postoperative scores of the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS-III) were reviewed. Mean (SD) change in AC-PC length (DeltaAC-PC) was 0.6 (0.4) mm. There was no statistically significant difference in DeltaAC-PC between groups when examining anatomic target subgroups (P =.95), age subgroups (P = .63), sex (P = .59), and unilateral versus bilateral implantation (P =.15). The mean (SD) vector changes for the commissural points were: -0.1 (0.3) mm in X, -0.4 (0.6) mm in Y, and -0.1 (0.7) mm in Z for the AC; and -0.1 (0.3) mm in X, -0.2 (0.7) mm in Y, and 0.0 (0.7) mm in Z for the PC. There was a negligible correlation between the magnitude of brain shift and percentage improvement in UPDRS-III off-medication in patients undergoing STN DBS for PD (R <0.01). Brain shift has long been considered an issue in stereotactic targeting during DBS procedures. However, with the image-guided approach and surgical technique used in this study, subcortical brain shift was extremely limited and did not appear to adversely affect clinical outcome.

  7. Cranial nerve functional neurosurgery : Evaluation of surgical practice

    NARCIS (Netherlands)

    Le Guerinel, C.; Sindou, M.; Auque, J.; Blondet, E.; Brassier, G.; Chazal, J.; Cuny, E.; Devaux, B.; Fontaine, D.; Finiels, P. -J.; Fuentes, J. -M.; D'Haens, J.; Massager, N.; Mercier, Ph.; Mooij, J.; Nuti, C.; Rousseaux, P.; Serrie, A.; Stecken, J.; de Waele, L.; Keravel, Y.

    We report the results of an investigation carried out on the activity of functional neurosurgery of the cranial nerves in the French-speaking countries, based on the analysis of a questionnaire addressed to all the members of the SNCLF Eighteen centers responded to this questionnaire., which showed

  8. Experimental and clinical standards, and evolution of lasers in neurosurgery.

    Science.gov (United States)

    Devaux, B C; Roux, F X

    1996-01-01

    From initial experiments of ruby, argon and CO2 lasers on the nervous system so far, dramatic progress was made in delivery systems technology as well as in knowledge of laser-tissue interaction effects and hazards through various animal experiments and clinical experience. Most surgical effects of laser light on neural tissue and the central nervous system (CNS) are thermal lesions. Haemostasis, cutting and vaporization depend on laser emission parameters--wavelength, fluence and mode--and on the exposed tissues optical and thermal properties--water and haemoglobin content, thermal conductivity and specific heat. CO2 and Nd-YAG lasers have today a large place in the neurosurgical armamentarium, while new laser sources such as high power diode lasers will have one in the near future. Current applications of these lasers derive from their respective characteristics, and include CNS tumour and vascular malformation surgery, and stereotactic neurosurgery. Intracranial, spinal cord and intra-orbital meningiomas are the best lesions for laser use for haemostasis, dissection and tissue vaporization. Resection of acoustic neuromas, pituitary tumours, spinal cord neuromas, intracerebral gliomas and metastases may also benefit from lasers as accurate, haemostatic, non-contact instruments which reduce surgical trauma to the brain and eloquent structures such as brain stem and cranial nerves. Coagulative lasers (1.06 microns and 1.32 microns Nd-YAG, argon, or diode laser) will find an application for arteriovenous malformations and cavernomas. Any fiberoptic-guided laser will find a use during stereotactic neurosurgical procedures, including image-guided resection of tumours and vascular malformations and endoscopic tumour resection and cysts or entry into a ventricle. Besides these routine applications of lasers, laser interstitial thermotherapy (LITT) and photodynamic therapy (PDT) of brain tumours are still in the experimental stage. The choice of a laser in a

  9. What Have We Learned About Movement Disorders from Functional Neurosurgery?

    Science.gov (United States)

    Lozano, Andres M; Hutchison, William D; Kalia, Suneil K

    2017-07-25

    Modern functional neurosurgery for movement disorders such as Parkinson's disease, tremor, and dystonia involves the placement of focal lesions or the application of deep brain stimulation (DBS) within circuits that modulate motor function. Precise targeting of these motor structures can be further refined by the use of electrophysiological approaches. In particular, microelectrode recordings enable the delineation of neuroanatomic structures. In the course of these operations, there is an opportunity not only to map basal ganglia structures but also to gain insights into how disturbances in neural activity produce movement disorders. In this review, we aim to highlight what the field has uncovered thus far about movement disorders through DBS. The work to date lays the foundation for future studies that will shed further light on dysfunctional circuits mediating diseases of the nervous system and how we might modulate these circuits therapeutically.

  10. Russell Meyers (1905-1999): pioneer of functional and ultrasonic neurosurgery.

    Science.gov (United States)

    Abel, Taylor J; Walch, Timothy; Howard, Matthew A

    2016-12-01

    Advances in functional neurosurgery, including neuromodulation and more recently ultrasonic ablation of basal ganglia structures, have improved the quality of life for patients with debilitating movement disorders. What is little known, however, is that both of these neurosurgical advances, which remain on the cutting edge, have their origin in the pioneering work of Russell Meyers, whose contributions are documented in this paper. Meyers' published work and professional correspondence are reviewed, in addition to documents held by the Department of Neurosurgery at the University of Iowa. Meyers was born in Brooklyn, New York, and received his neurosurgical training at hospitals in New York City under Jefferson Browder. In 1939, a chance encounter with a young woman with damaged bilateral ventral striata convinced Meyers that the caudate could be resected to treat Parkinsonism without disrupting consciousness. Shortly thereafter, he performed the first caudate resection for postencephalitic Parkinsonism. In 1946, Meyers became the first chairman of neurosurgery at the State University of Iowa (now the University of Iowa), which led to the recruitment of 8 faculty members and the training of 18 residents during his tenure (1946-1963). Through collaboration with the Fry brothers at the University of Illinois, Meyers performed the first stereotactic ultrasonic ablations of deep brain structures to treat tremor, choreoathetosis, dystonia, intractable pain, and hypothalamic hamartoma. Meyers left academic neurosurgery in 1963 for reasons that are unclear, but he continued clinical neurosurgery work for several more years. Despite his early departure from academic medicine, Meyers' contributions to functional neurosurgery provided a lasting legacy that has improved the lives of many patients with movement disorders.

  11. Paradoxes of functional neurosurgery: clues from basal ganglia recordings.

    Science.gov (United States)

    Brown, Peter; Eusebio, Alexandre

    2008-01-01

    Deep brain stimulation (DBS) can be remarkably effective in treating movement disorders such as Parkinson's disease, dystonia, and essential tremor. Yet these effects remain essentially unexplained, even paradoxical. Equally challenging is the fact that DBS of motor targets in the basal ganglia appears to reverse abnormalities of movement without any obvious deleterious effects on remaining aspects of movement. Here, we explore the extent to which the noisy signal hypothesis might help solve some of these apparent paradoxes. Essentially the hypothesis, first tentatively advanced by Marsden and Obeso (1994), suggests that disease leads to a pattern of basal ganglia activity that disrupts local and distant function and that surgery acts to suppress or override this noisy signal. Critical to the success this theory is that different disease phenotypes are associated with different patterns of noisy signal, and we survey the evidence to support this contention, with specific emphasis on different types of pathological synchronization. However, just as DBS may suppress or override noisy signals in the basal ganglia, it must equally antagonize any remaining physiological functioning in these key motor structures. We argue that the latter effect of DBS becomes manifest when baseline motor performance is relatively preserved, i.e., when pathological activity is limited. Under these circumstances, the deleterious effects of DBS are no longer obscured by its therapeutic actions in suppressing noisy signals. Whether true, oversimplified or simply incorrect, the noisy signal hypothesis has served to focus attention on the detailed character of basal ganglia discharge and its variation with disease and therapy. 2007 Movement Disorder Society

  12. [A new operational method of functional neurosurgery combining micro-recording and MRI stereotaxy for the treatment of Parkinson's disease].

    Science.gov (United States)

    Nishimura, H; Hirai, T

    1993-02-01

    We have developed a new operational method for stereotactic functional neurosurgery using MRI stereotaxy combined with microelectrode recording. MRI stereotaxy shows us the individual variations of thalamic configurations. The tentative target points were determined using the MRI stereotaxy assisted software system which revised the distortion of MRI images. Consequently, the accuracy and safety of the microelectrode recording were increased. This, in turn, increased the accuracy of stereotactic thalamotomy while producing encouraging operational outcomes. The effectiveness of stereotactic thalamotomy for Parkinson's disease was confirmed by these excellent operative results. The symptoms improved and the dosage of medications, including L-DOPA, decreased. Furthermore, our results indicate that the distributing area of deep sensory neurons in the thalamus extended more posteriorly and upward than previously expected. Therefore, the functional and anatomical similarity between the human and monkey thalamus was reaffirmed. In this report, based on the above data, we reevaluated the neural mechanism of tremor and the role of stereotactic functional neurosurgery for Parkinson's disease.

  13. Combined x-ray and magnetic resonance imaging facility: application to image-guided stereotactic and functional neurosurgery.

    Science.gov (United States)

    Hunsche, Stefan; Sauner, Dieter; Maarouf, Mohammad; Lackner, Klaus; Sturm, Volker; Treuer, Harald

    2007-04-01

    To assess the feasibility of a hybrid imaging setup combining x-ray and magnetic resonance imaging (MRI) in the setting of both stereotactic and functional neurosurgery. A combined x-ray and MRI scanning facility with a trolley system for a fast patient transfer between both modalities was installed in a neurosurgical setting. A registration algorithm for fusion of MRI scans and x-ray images was derived for augmentation of fluoroscopic x-ray projection images with MRI scan data, such as anatomic structures and planned probe trajectories. Phantom measurements were obtained between both modalities for estimation of registration accuracy. Practical application of our system in stereotactic and functional neurosurgery was tested in brachytherapy, deep brain stimulation, and motor cortex stimulation. Phantom measurements yielded a mean spatial deviation of 0.7 +/- 0.3 mm with a maximum deviation of 1.1 mm for MRI scans versus x-rays. Augmentation of x-ray images with MRI scan data allowed intraoperative verification of the planned trajectory and target in three types of neurosurgical procedures: positioning iodine seeds in brachytherapy in one case with cerebellar metastasis, placement of electrodes for deep brain stimulation in two cases of advanced Parkinson's disease, and placement of an epidural grid for motor cortex stimulation in two cases of intractable pain. Combined x-ray and MRI-guided stereotactic and functional neurosurgery is feasible. Augmentation of x-ray projection images with MRI scan data, such as planned probe trajectories and MRI scan segmented anatomic structures may be beneficial for probe guidance in stereotactic and functional neurosurgery.

  14. Human pallidothalamic and cerebellothalamic tracts: anatomical basis for functional stereotactic neurosurgery

    Science.gov (United States)

    Gallay, Marc N.; Jeanmonod, Daniel; Liu, Jian

    2008-01-01

    Anatomical knowledge of the structures to be targeted and of the circuitry involved is crucial in stereotactic functional neurosurgery. The present study was undertaken in the context of surgical treatment of motor disorders such as essential tremor (ET) and Parkinson’s disease (PD) to precisely determine the course and three-dimensional stereotactic localisation of the cerebellothalamic and pallidothalamic tracts in the human brain. The course of the fibre tracts to the thalamus was traced in the subthalamic region using multiple staining procedures and their entrance into the thalamus determined according to our atlas of the human thalamus and basal ganglia [Morel (2007) Stereotactic atlas of the human thalamus and basal ganglia. Informa Healthcare Inc., New York]. Stereotactic three-dimensional coordinates were determined by sectioning thalamic and basal ganglia blocks parallel to stereotactic planes and, in two cases, by correlation with magnetic resonance images (MRI) from the same brains prior to sectioning. The major contributions of this study are to provide: (1) evidence that the bulks of the cerebellothalamic and pallidothalamic tracts are clearly separated up to their thalamic entrance, (2) stereotactic maps of the two tracts in the subthalamic region, (3) the possibility to discriminate between different subthalamic fibre tracts on the basis of immunohistochemical stainings, (4) correlations of histologically identified fibre tracts with high-resolution MRI, and (5) evaluation of the interindividual variability of the fibre systems in the subthalamic region. This study should provide an important basis for accurate stereotactic neurosurgical targeting of the subthalamic region in motor disorders such as PD and ET. PMID:18193279

  15. A comparison of two surgical approaches in functional neurosurgery: individualized versus conventional stereotactic frames.

    Science.gov (United States)

    Matzke, Cornelia; Lindner, Dirk; Schwarz, Johannes; Classen, Joseph; Hammer, Niels; Weise, David; Rumpf, Jost-Julian; Fritzsch, Dominik; Meixensberger, Jürgen; Winkler, Dirk

    2015-01-01

    The individualized Starfix® miniframe belongs to a new generation of stereotactic systems enabling high-precision electrode placement with considerably better time-efficiency in deep brain stimulation (DBS). We evaluated the usability and reliability of this novel technique in patients with idiopathic Parkinson's disease (IPD) and compared surgical and clinical results with those obtained in a historical group in which a conventional stereotactic frame was employed. Sixty patients underwent surgery for implantation of DBS electrodes in the subthalamic nucleus. In 31 of them (group I) a conventional Zamorano-Dujovny frame was used and in 29 of them (group II) a Starfix® miniframe was used. Image fusion of preoperatively acquired 3D T1w and T2w 1.5 T MR-image series was used for the targeting procedure. Placement of the test electrodes and permanent electrodes corresponded to standard functional neurosurgery and included microelectrode recording and macrostimulation. Clinical (L-Dopa equivalent dose, United Parkinson's disease rating scale part III) and time for surgical electrode implantation were evaluated postoperatively in a 3-, 6- and 12-month follow-up. Twelve months postoperatively, L-Dopa dose was significantly reduced from 685.19 to 205.88 mg/day and from 757.92 to 314.42 mg/day in groups I and II, respectively. A comparable reduction of the LED could be observed 1 year after surgery. Motor function has improved in a significant and identical manner with 59% (group I) and 61% (group II). Besides clinical effects by stimulation therapy there was a significantly reduced surgery time required for electrode implantation using the Starfix® miniframe (group I: 234.1 min, group II: 173.6 min; p < 0.001). Individualized miniframes such as the Starfix® miniframe allow implantation of DBS electrodes in IPD that is equally effective as conventional systems. The time efficiency achieved in surgery using of the Starfix® system helps to minimize

  16. Seeking tools for image fusion between computed tomography, structural and functional magnetic resonance methods for applications in neurosurgery

    Directory of Open Access Journals (Sweden)

    Liana Guerra Sanches da Rocha

    2012-06-01

    Full Text Available Objective: To evaluate tools for the fusion of images generatedby tomography and structural and functional magnetic resonanceimaging. Methods: Magnetic resonance and functional magneticresonance imaging were performed while a volunteer who hadpreviously undergone cranial tomography performed motor andsomatosensory tasks in a 3-Tesla scanner. Image data were analyzedwith different programs, and the results were compared. Results:We constructed a flow chart of computational processes that allowedmeasurement of the spatial congruence between the methods. Therewas no single computational tool that contained the entire set offunctions necessary to achieve the goal. Conclusion: The fusion ofthe images from the three methods proved to be feasible with the useof four free-access software programs (OsiriX, Register, MRIcro andFSL. Our results may serve as a basis for building software that willbe useful as a virtual tool prior to neurosurgery.

  17. Functional lesional neurosurgery for tremor—a protocol for a systematic review and meta-analysis

    Science.gov (United States)

    Krauss, Joachim K; Chang, Jin Woo; Bhatia, Kailash P; Kägi, Georg

    2017-01-01

    Introduction The recent introduction of incision-less lesional neurosurgery using Gamma Knife and MRI-guided focused ultrasound has revived interest in lesional treatment options for tremor disorders. Preliminary literature researches reveal that the consistency of treatment effects after lesional neurosurgery for tremor has not formally been assessed yet. Similarly, the efficacy of different targets for lesional treatment and incidence of persistent side effects of lesional neurosurgical interventions has not been comprehensively assessed. This work therefore aims to describe a suitable process how to review the existing literature on efficacy and persistent side effects of lesional neurosurgical treatment for tremor due to Parkinson’s disease, essential tremor, multiple sclerosis and midbrain/rubral tremor. Methods and analysis We will search electronic databases (Medline, Cochrane) and reference lists of included articles for studies reporting lesional interventions for tremor in cohorts homogeneous for tremor aetiology and intervention (technique and target). We will include cohorts with a minimum number of five subjects and follow-up of 2 months. One investigator will perform the initial literature search and two investigators then independently decide which references to include for final efficacy and safety analysis. After settling of disagreement, data will be extracted from articles using a standardised template. We will perform a random-effect meta-analysis calculating standardised mean differences (Hedge’s g) for comparison in Forest plots and subgroup analysis after assessment of heterogeneity using I2 statistics. Ethics and dissemination This study will summarise the available evidence on the efficacy of lesional interventions for the most frequent tremor disorders, as well as for the incidence rate of persisting side effects after unilateral lesional treatment. This data will be useful to guide future work on incision-less lesional interventions

  18. Functional MRI for planning in neurosurgery; Funktionelle MR-Bildgebung fuer die neurochirurgische Operationsplanung

    Energy Technology Data Exchange (ETDEWEB)

    Erb, M. [Sektion fuer Experimentelle Kernspinresonanz des ZNS, Abt. Neuroradiologie, Universitaetsklinikum Tuebingen (Germany); Saur, R. [Sektion fuer Experimentelle Kernspinresonanz des ZNS, Abt. Neuroradiologie, Universitaetsklinikum Tuebingen (Germany); Augenklinik des Universitaetsklinikums Tuebingen (Germany); Klinik fuer Psychiatrie und Psychotherapie des Universitaetsklinikums Tuebingen (Germany)

    2007-07-01

    Beside structural images from CT and MR, functional data about localization of brain activations with different tasks becomes more and more important for presurgical planning. With this method, it's possible to depict mainly primary sensory and motoric areas, but also higher functions like speech and memory. To judge this information adequately, one has to be aware of the variability of activation pattern dependent on chosen threshold. Especially, the absence of such activation at a given location does not necessary mean that this area has no function. The reliability of a measurement strongly depends on efficiency of experimental design and cooperation of the patient. Therefore, short and easy tasks which can be performed in a block design should be preferred. Information about localization of functions determined by fMRI can mainly be used for presurgical planning. Intraoperative usage in the navigation system is problematic due to the brain shift. Therefore, intraoperative imaging together with dynamic adaptation using nonlinear deformation algorithms may improve the value of fMRI in the future. (orig.)

  19. Functional Neurosurgery in the Human Thalamus by Transcranial Magnetic Resonance Guided Focused Ultrasound

    Science.gov (United States)

    Werner, Beat; Morel, Anne; Jeanmonod, Daniel; Martin, Ernst

    2009-04-01

    Potential applications of Transcranial Magnetic Resonance guided Focused Ultrasound (TcMRgFUS) include treatment of functional brain disorders, such as Parkinson's disease, dystonia and tremor, neurogenic pain and tinnitus, neuropsychiatric disorders and epilepsy. In this study we demonstrate the feasibility of non-invasive TcMRgFUS ablation of clinically well established targets in the human thalamus that are currently accessed stereotactically by interventional strategies based on the concept of the thalamocortical dysrhythmia (TCD). Thermal hotspots suitable for clinical intervention were created successfully in anatomical preparations of human ex-vivo heads under pseudo clinical conditions. The hotspots could be positioned at the target locations as needed and local energy deposition was sufficient to create tissue ablation. Numerical simulations based on these experimental data predict that the acoustic energy needed to create ablative lesions in-vivo will be within limits that can safely applied.

  20. Discovering neurosurgery: new frontiers.

    Science.gov (United States)

    Rutka, James T

    2011-12-01

    Over the centuries, discoveries of lands unknown, treasures lost and buried, and formulas to delineate physicochemical processes have led to advancements in our understanding of how the world is structured and governed. In science and medicine, discoveries are frequently made following deliberate periods of observation and experimentation to test hypotheses. However, in some instances, discoveries may arise either following a "eureka moment" that transcends rigorous scientific experimentation or following a serendipitous observation. In many instances, scientific discoveries will lead to new inventions that are aimed at improving the manner in which tasks or operations are performed. In this address, some of the key discoveries in science and medicine that have impacted significantly on the field of neurosurgery are described. Some of these include discoveries in neuroanatomy, anesthesiology, infectious diseases, antisepsis, and radiology. Discoveries in the field of molecular science, from the discovery of DNA to next-generation DNA sequencing, which have helped improve the diagnosis and prognosis of neurosurgical patients with conditions such as brain tumors, are also described. In the end, these discoveries have led us to new frontiers in the subspecialty practice of neurosurgery. Navigating our way through these new frontiers will undoubtedly lead to additional discoveries that are unimaginable at present but bound to improve the future care of neurosurgical patients.

  1. [Deep brain recording and length of surgery in stereotactic and functional neurosurgery for movement disorders].

    Science.gov (United States)

    Teijeiro, Juan; Macías, Raúl J; Maragoto, Carlos; García, Iván; Alvarez, Mario; Quintanal, Nelson E

    2014-01-01

    Our objectives were to study the length of multi-unit recordings (MURs) of brain activity in 20 years of movement disorder neurosurgeries and to determine the number of times in which it was necessary for the teams using single-unit recording (SUR) to explore all the electrode tracks in the simultaneously recorded sites (SRS). This was a retrospective descriptive statistical analysis of MUR length on 4,296 tracks in 952 surgeries. The exclusion criteria were: tracks with fewer than 5 recorded signals, tracks that had a signal length different from the habitual 2s, or there being unusual situations not related to the MUR, as well as the first 20 surgeries of each surgical target. This yielded a total of 3,448 tracks in 805 surgeries. We also determined the number of the total 952 surgeries in which all the tracks in the SURs of the SRS were explored. The mean and its confidence interval (P=.05) of time per MUR track were 5.49±0.16min in subthalamic nucleus surgery, 8.82±0.24min in the medial or internal globus pallidus) and 18.51±1.31min in the ventral intermediate nucleus of the thalamus. For the total sum of tracks per surgery, in 75% of cases the total time was less than 39min in subthalamic nucleus, almost 42min in the medial or internal globus pallidus and less than 1h and 17min in ventral intermediate nucleus of the thalamus. All the tracks in the SUR SRS were explored in only 4.2% of the surgeries. The impact of MUR on surgical time is acceptable for this guide in objective localization for surgical targets, without having to use several simultaneous electrodes (not all indispensable in most of the cases). Consequently, there is less risk for the patient. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  2. Laser applications in neurosurgery

    Science.gov (United States)

    Cerullo, Leonard J.

    1985-09-01

    The "false start" of the laser in neurosurgery should not be misconstrued as a denial of the inherent advantages of precision and gentleness in dealing with neural tissue. Rather, early investigators were frustrated by unrealistic expectations, cumbersome equipment, and a general ignorance of microtechnique. By the early 70s, microneurosurgery was well established, surgical laser equipment for free hand and microlinked application had been developed, and a more realistic view of the limitations of the laser had been established. Consequently, the late 70s really heralded the renaissance of the laser in neurosurgery. Since then, there has been an overwhelming acceptance of the tool in a variety of clinical situations, broadly categorized in five groups. 1)|Perhaps the most generally accepted area is in the removal of extra-axial tumors of the brain and spinal cord. These tumors, benign by histology but treacherous by location, do not present until a significant amount of neurological compensation has already occurred. The application of additional trauma to the neural tissue, whether by further tumor growth or surgical manipulation, frequently results in irreversible damage. Here, the ability of the laser to vaporize tissue, in a fairly hemostatic fashion, without mechanical or thermal damage to sensitive surrounding tissues, is essential. 2)|The ability to incise delicate neural tissue with minimal spread of thermal destruction to adjacent functioning tissue makes the laser the ideal instrument when tumors deep under the surface are encountered in the brain or spinal cord. Thus, the second group of applications is in the transgression of normal neural structures to arrive at deeper pathological tissue. 3)|The third area of benefit for the laser in neurosurgery has been in the performance of neuroablative procedures, calling for deliberate destruction of functioning neural tissue in a controlled fashion. Again, the precision and shape confinement of the destructive

  3. The emerging role of transcranial magnetic resonance imaging-guided focused ultrasound in functional neurosurgery.

    Science.gov (United States)

    Weintraub, David; Elias, W Jeffrey

    2017-01-01

    To review the emerging role of transcranial MR-guided focused ultrasound as a treatment and research modality for functional neurological disorders, we summarize recent clinical and preclinical studies. Clinical trials have investigated the safety and efficacy of thermal lesions created by transcranial, high-intensity focused ultrasound. Preclinical work has additionally investigated the ability to disrupt the blood-brain barrier and to produce reversible neuromodulation with focused ultrasound utilizing lower intensities. We discuss ongoing trials and future avenues of investigation. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  4. Functional neurosurgery in Parkinson's disease: a long journey from destruction over modulation towards restoration.

    Science.gov (United States)

    Nikkhah, Guido; Carvalho, Gustavo Adolpho; Pinsker, Marcus

    2013-01-01

    Neurosurgical treatment of Parkinson's disease (PD) has re-gained considerable attention over the last two decades due to a better understanding of the pathophysiology of the basal ganglia, the long-term complications of medical treatment, and advances in neuroimaging and neurosurgical techniques. The introduction of deep brain stimulation (DBS) has created new perspectives for the surgical management of PD patients, due to the low morbidity, reversibility and improvement of both motor function and quality of life as compared to the lesioning techniques. We present an overview of basic principles, history, indications, and results of current neurosurgical techniques available in PD.

  5. Noninvasive functional neurosurgery using transcranial MR imaging-guided focused ultrasound.

    Science.gov (United States)

    Bauer, Ronald; Martin, Ernst; Haegele-Link, Stefan; Kaegi, Georg; von Specht, Moritz; Werner, Beat

    2014-01-01

    Transcranial magnetic resonance imaging-guided focused ultrasound (tcMRgFUS) is a novel technique to supplement the spectrum of established neurosurgical interventions. In contrast to traditional ablative procedures, tcMRgFUS is noninvasive and entirely imaging-guided with continuous temperature measurements at and around the target in real time. It has no trajectory restrictions and does not involve ionizing radiation. Since no device is implanted into the brain or the body, there is no restriction to future diagnostic work-up with MR imaging. The ability to treat a variety of chronic, therapy-resistant neurological diseases by precisely focusing ultrasound energy to desired targets in the thalamus, subthalamus and basal ganglia while avoiding collateral tissue damage is certainly attractive. Ongoing clinical studies on over 130 patients with neuropathic pain, essential tremor, Parkinson's disease and obsessive-compulsive disorder are very promising and demonstrate that ultrasound energy can precisely be focused through the intact skull, without overheating it. Varying the ultrasound parameters allows not only to ablate pathological tissue, or silence dysfunctional neuronal circuits, but also to modulate neural functions, as shown in preclinical studies. Transcranial magnetic resonance imaging-guided focused ultrasound is a novel, noninvasive, alternative treatment option for patients with therapy-resistant movement disorders, such as essential tremor and Parkinson's disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Functional neurosurgery (part 2)

    African Journals Online (AJOL)

    are added, followed by pain-modification agents such as tricyclic antidepressants and some selective anticonvulsants. Throughout the treatment process, adjuncts to medication should be employed, such as psychotherapy, electrotherapy as used by physiotherapists, and play and music therapy. These contribute a great ...

  7. History of Korean Neurosurgery.

    Science.gov (United States)

    Hwang, Sung-nam

    2015-08-01

    The year 2012 was the 50th anniversary of the Korean Neurosurgical Society, and in 2013, the 15th World Congress of Neurosurgery took place in Seoul, Korea. Thus, it is an appropriate occasion to introduce the world to the history of the Korean Neurosurgical Society and the foundation, development, and growth of Korean neurosurgery. Historical materials and pictures were collected and reviewed from the history book and photo albums of the Korean Neurosurgical Society. During the last 50 years, the Korean Neurosurgical Society and Korean neurosurgery have developed and grown enormously not only in quantity but also in quality. In every aspect, the turning point from the old to the new era of the Korean Neurosurgical Society and Korean neurosurgery was the year 1980. Copyright © 2015. Published by Elsevier Inc.

  8. Computers and neurosurgery.

    Science.gov (United States)

    Shaikhouni, Ammar; Elder, J Bradley

    2012-11-01

    At the turn of the twentieth century, the only computational device used in neurosurgical procedures was the brain of the surgeon. Today, most neurosurgical procedures rely at least in part on the use of a computer to help perform surgeries accurately and safely. The techniques that revolutionized neurosurgery were mostly developed after the 1950s. Just before that era, the transistor was invented in the late 1940s, and the integrated circuit was invented in the late 1950s. During this time, the first automated, programmable computational machines were introduced. The rapid progress in the field of neurosurgery not only occurred hand in hand with the development of modern computers, but one also can state that modern neurosurgery would not exist without computers. The focus of this article is the impact modern computers have had on the practice of neurosurgery. Neuroimaging, neuronavigation, and neuromodulation are examples of tools in the armamentarium of the modern neurosurgeon that owe each step in their evolution to progress made in computer technology. Advances in computer technology central to innovations in these fields are highlighted, with particular attention to neuroimaging. Developments over the last 10 years in areas of sensors and robotics that promise to transform the practice of neurosurgery further are discussed. Potential impacts of advances in computers related to neurosurgery in developing countries and underserved regions are also discussed. As this article illustrates, the computer, with its underlying and related technologies, is central to advances in neurosurgery over the last half century. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Establishing reconstructive neurosurgery as a subspecialty.

    Science.gov (United States)

    Brown, Justin M; Mahan, Mark A; Mandeville, Ross; Carter, Bob S

    2017-07-01

    Neurosurgery is experiencing the emergence of a new subspecialty focused on function restoration. New, evolving, and reappraised surgical procedures have provided an opportunity to restore function to many patients with previously undertreated disorders. Candidates for reconstruction were previously limited to those with peripheral nerve and brachial plexus injuries, but this has been expanded to include stroke, spinal cord injury, and a host of other paralyzing disorders affecting both upper and lower motor neurons. Similar to the recent evolution of the well-established subdisciplines of spinal and vascular neurosurgery, reconstructive neurosurgery requires the adaptation of techniques and skills that were not traditionally a part of neurosurgical training. Neurosurgeons-as the specialists who already manage this patient population and possess the requisite surgical skills to master the required techniques-have a unique opportunity to lead the development of this field. The full development of this subspecialty will lay the foundation for the subsequent addition of emerging treatments, such as neuroprosthetics and stem cell-based interventions. As such, reconstructive neurosurgery represents an important aspect of neurosurgical training that can ameliorate many of the deficits encountered in the traditional practice of neurosurgery.

  10. [Neurosurgery in the elderly patient: Geriatric neurosurgery].

    Science.gov (United States)

    González-Bonet, Luis Germán; Tarazona-Santabalbina, Francisco-José; Lizán Tudela, Luis

    2016-01-01

    Between 2000 and 2050, the proportion of the world's population over 60 years will double, and the number of people aged 80 and older will quadruple. Health professional training does not include instructions about specific care for older people. The World Health Organization maintains that all health providers should be trained on ageing issues. Thus, it is proposed to analyse the effect of ageing on Neurosurgery in our country. A retrospective historical cohort study was performed on individuals age 70 years or older admitted to the Neurosurgery or the Intensive Care Unit of our hospital, with neurosurgical disease, between two periods: 1999-2000 and 2010-2011. An analysis was made on variables such as: age, pathology, length of stay, comorbidity, performance status, re-admissions and mortality. Similar numbers of patients were admitted during the two periods: 409 and 413. However, there was an increase of 77.5% in patients older than 70 years: 80 versus 142. Statistically significant differences were observed in the Charlson Comorbidity Index, the admission Glasgow Coma Scale (GCS) score, length of stay, and re-admissions. Comorbidity and admission GCS score were particularly worse in the second period. Nevertheless, the mean length of stay was lower in that period, but showing more hospital re-admissions. After multivariate analysis, it was observed that re-admissions were associated with comorbidity, but not with early hospital discharge. No differences were found in performance status or mortality. A very considerable increase in percentage of patients older than 70 years old was found. There were no differences in performance status or mortality, which was probably due to the multidisciplinary management of these patients. The results of this study support the development of an interdisciplinary work group dedicated to Geriatric Neurosurgery. Copyright © 2015 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  11. Functional Magnetic Resonance Imaging (fMRI), Pre-intraoperative Tractography in Neurosurgery: The Experience of Sant' Andrea Rome University Hospital.

    Science.gov (United States)

    D'Andrea, Giancarlo; Trillo', Giuseppe; Picotti, Veronica; Raco, Antonino

    2017-01-01

    The goal of neurosurgery for cerebral intraparenchymal neoplasms of the eloquent areas is maximal resection with the preservation of normal functions, and minimizing operative risk and postoperative morbidity. Currently, modern technological advances in neuroradiological tools, neuronavigation, and intraoperative magnetic resonance imaging (MRI) have produced great improvements in postoperative morbidity after the surgery of cerebral eloquent areas. The integration of preoperative functional MRI (fMRI), intraoperative MRI (volumetric and diffusion tensor imaging [DTI]), and neuronavigation, defined as "functional neuronavigation" has improved the intraoperative detection of the eloquent areas. We reviewed 142 patients operated between 2004 and 2010 for intraparenchymal neoplasms involving or close to one or more major white matter tracts (corticospinal tract [CST], arcuate fasciculus [AF], optic radiation). All the patients underwent neurosurgery in a BrainSUITE equipped with a 1.5 T MR scanner and were preoperatively studied with fMRI and DTI for tractography for surgical planning. The patients underwent MRI and DTI during surgery after dural opening, after the gross total resection close to the white matter tracts, and at the end of the procedure. We evaluated the impact of fMRI on surgical planning and on the selection of the entry point on the cortical surface. We also evaluated the impact of preoperative and intraoperative DTI, in order to modify the surgical approach, to define the borders of resection, and to correlate this modality with subcortical neurophysiological monitoring. We evaluated the impact of the preoperative fMRI by intraoperative neurophysiological monitoring, performing "neuronavigational" brain mapping, following its data to localize the previously elicited areas after brain shift correction by intraoperative MRI. The mean age of the 142 patients (89 M/53 F) was 59.1 years and the lesion involved the CST in 66 patients (57 %), the language

  12. Medical errors in neurosurgery.

    Science.gov (United States)

    Rolston, John D; Zygourakis, Corinna C; Han, Seunggu J; Lau, Catherine Y; Berger, Mitchel S; Parsa, Andrew T

    2014-01-01

    Medical errors cause nearly 100,000 deaths per year and cost billions of dollars annually. In order to rationally develop and institute programs to mitigate errors, the relative frequency and costs of different errors must be documented. This analysis will permit the judicious allocation of scarce healthcare resources to address the most costly errors as they are identified. Here, we provide a systematic review of the neurosurgical literature describing medical errors at the departmental level. Eligible articles were identified from the PubMed database, and restricted to reports of recognizable errors across neurosurgical practices. We limited this analysis to cross-sectional studies of errors in order to better match systems-level concerns, rather than reviewing the literature for individually selected errors like wrong-sided or wrong-level surgery. Only a small number of articles met these criteria, highlighting the paucity of data on this topic. From these studies, errors were documented in anywhere from 12% to 88.7% of cases. These errors had many sources, of which only 23.7-27.8% were technical, related to the execution of the surgery itself, highlighting the importance of systems-level approaches to protecting patients and reducing errors. Overall, the magnitude of medical errors in neurosurgery and the lack of focused research emphasize the need for prospective categorization of morbidity with judicious attribution. Ultimately, we must raise awareness of the impact of medical errors in neurosurgery, reduce the occurrence of medical errors, and mitigate their detrimental effects.

  13. History of Neurosurgery in Palestine.

    Science.gov (United States)

    Darwazeh, Rami; Darwazeh, Mazhar; Sun, Xiaochuan

    2017-08-01

    Palestinian neurosurgery started with Dr. Antone Tarazi as the first Palestinian neurosurgeon. Before that, there was no organized neurosurgery specialty, and general surgeons performed neurosurgical procedures. Here we review the history of neurosurgery and neurosurgical applications in Palestine, evaluate some limitations of the current system, and discuss major challenges to improving this system. We collected information from various sources in either English or Arabic. The development of neurosurgery and neurosurgical training in Palestine began in 1960 with the first center established in Jerusalem, which provided much-needed neurosurgical services and training in the fields of neurosurgery and neurology. Palestine has produced a number of its own neurosurgeons and has promoted further progress by establishing the Palestinian Neurosurgical Society in 2014. Today, there are 34 neurosurgeons (including 1 female neurosurgeon) and 17 residents providing expert care in 17 centers across Palestine, along with 1 neurosurgical residency program. Neurosurgery in Palestine has faced many challenges, some of which have been overcome. However, there remain many challenges, which will require much time and effort to surmount. Political stabilization is a significant factor in the progress of neurosurgery in Palestine. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. A Master-Slave Haptic System for Neurosurgery

    Directory of Open Access Journals (Sweden)

    Vanni Zanotto

    2011-01-01

    Full Text Available In recent years, new surgical tools have been designed to improve treatment results and lower patient trauma. Nevertheless, the dexterity and accuracy required for the positioning of new tools are often unreachable, if surgeons are not assisted by suitable systems. Significant advantages are derived from the introduction of computer and robot technologies. For that reason, the interaction between robotic systems and surgeons today is producing new interest worldwide both in medical and engineering fields. In particular, medical robotics has found fruitful ground in neurosurgical applications, since the high functional density of the central nervous system requires strict accuracy constraints on tool positioning. As a matter of fact, the major benefits of robots, such as precision, accuracy and repeatability, make them ideal as neurosurgeons’ assistants. This paper presents a master-slave haptic robotic system for minimally invasive neurosurgery, which can aid surgeons in performing safer and more accurate stereotactic neurosurgical treatments. The design of the proposed system is based on LANS (Linear Actuator for NeuroSurgery, which has been developed by our Research Group. Experimental test aimed at showing the added value of the DAANS system over its predecessor, the effectiveness of conformational caps and of the added rotational degree of freedom are scheduled for the upcoming months.

  15. Functional MR imaging of working memory before neurosurgery; Funktionelle MR-Bildgebung des Arbeitsgedaechtnisses vor neurochirurgischen Eingriffen

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, A.P. [Abt. Diagnostische Radiologie, Universitaetsklinikum Ulm (Germany); Groen, G. [Abt. Psychiatrie III, Universitaetsklinikum Ulm (Germany); Braun, V. [Neurochirurgie, Ev. Jung-Stilling-Krankenhaus Siegen (Germany)

    2007-07-01

    Information concerning the tissue adjacent to a brain tumour is crucial for planning and performing a neurosurgical intervention. In this study, we evaluated the usefulness of functional imaging of working memory in terms of working memory preservation. Working memory performance of 14 patients with prefrontal tumours was tested preoperatively by means of a standardized neuropsychological test battery. Also, functional magnetic resonance imaging (fMRI) using a so-called two-back paradigm was performed to visualize brain areas related to that task. Working memory areas were reliably detected in all patients. Surgery was then planned on the basis of this information, and the data were used for intra-operative cranial neuronavigation. Three to twelve months after surgery, patients were tested again with the test battery in order to detect possible changes in working memory performance. In 13 cases the memory performance was unchanged, only one female patient had a slight impairment of working memory compared to the pre-operative status. (orig.)

  16. The history of neurosurgery at the University of Sao Paulo

    Directory of Open Access Journals (Sweden)

    Manoel Jacobsen Teixeira

    2014-03-01

    Full Text Available The history of neurosurgery at University of São Paulo comes from 1918, since its origins under the Department of Neurology from Chair of Psychiatric Clinic and Nervous Diseases. Professor Enjolras Vampré was the great inspiration for such medical specialty in the State of Sao Paulo. In 1929, the first neurosurgical procedures were performed in the recently (at time organized Section of Neurosurgery. The official inauguration of the Division of Functional Neurosurgery occurred at June 1977, with the presence of worldwide well-known neuroscientists. The division suffered a deep streamlining under the leadership of Professor Raul Marino Jr., between the decades of 1990 and 2000. At this time, it was structured with the sections of neurological surgery, functional neurosurgery and neurosurgical emergency. Since 2008, Professor Manoel Jacobsen Teixeira is the Chairman of the Division and has provided the Division with the best available technological resources, performing more than 3,000 surgeries a year and training professionals who will, certainly, be some of the future leaders of brazilian neurosurgery.

  17. The history of neurosurgery at the University of Sao Paulo.

    Science.gov (United States)

    Teixeira, Manoel Jacobsen; Figueiredo, Eberval Gadelha; Taricco, Mario Augusto; Plese, José Píndaro P; Flores, Camila; Teixeira, Saulo A; Luzio, José

    2014-03-01

    The history of neurosurgery at University of São Paulo comes from 1918, since its origins under the Department of Neurology from Chair of Psychiatric Clinic and Nervous Diseases. Professor Enjolras Vampré was the great inspiration for such medical specialty in the State of Sao Paulo. In 1929, the first neurosurgical procedures were performed in the recently (at time) organized Section of Neurosurgery. The official inauguration of the Division of Functional Neurosurgery occurred at June 1977, with the presence of worldwide well-known neuroscientists. The division suffered a deep streamlining under the leadership of Professor Raul Marino Jr., between the decades of 1990 and 2000. At this time, it was structured with the sections of neurological surgery, functional neurosurgery and neurosurgical emergency. Since 2008, Professor Manoel Jacobsen Teixeira is the Chairman of the Division and has provided the Division with the best available technological resources, performing more than 3,000 surgeries a year and training professionals who will, certainly, be some of the future leaders of brazilian neurosurgery.

  18. Neurosurgery and Music; Effect of Wolfgang Amadeus Mozart.

    Science.gov (United States)

    Gasenzer, Elena Romana; Kanat, Ayhan; Neugebauer, Edmund

    2017-06-01

    The nervous system works like a great orchestra. Specifically, the music of Mozart with its "Mozart effect" is appropriate to use in neurosurgery. We investigated the relationship between Mozart's music and neurosurgery. We used digital catalogs like "PubMed" and the libraries of universities. Key words were "Wolfgang Amadeus Mozart" and "neurosurgery and music." In the first half of the 20th century, performing neurosurgery on some musicians, such as Maurice Ravel, Josef Hassid, and George Gershwin, resulted in a fatal outcome. The cause of this is probably that neurosurgery had not been developed yet in the first half of the 20th century. In the past 3 decades, the neurosurgical operations of musicians show that musicians have rich associations among auditory, somatic, and sensorial systems. It is clear that we have much to learn from studies about music and brain function that derive from our surgical experiences with patients. The neuronal plasticity of musicians' brains may be different from that of nonmusicians' brains. Musicians with enhanced motor skills have greater capacity for plasticity because of enriched interhemispheric connections. Listening to music and the effect of Mozart in neurosurgical practice, intensive care, or rehabilitation were documented in many studies. As authors, we mean something different: Its effectiveness should be studied. We concluded that in current neurosurgical practice, Mozart has an effect. More research and clinical studies are needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Seeking tools for image fusion between computed tomography, structural and functional magnetic resonance methods for applications in neurosurgery; Ferramentas para fusao de imagens dos metodos de tomografia computadorizada, ressonancia magnetica e ressonancia magnetica funcional para aplicacao pre-neurocirurgica

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Liana Guerra Sanches da, E-mail: liana@einstein.br [Departamento de Diagnostico por Imagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo (SP) (Brazil); Amaro Junior, Edson [Faculdade de Medicina, Universidade de Sao Paulo - USP, Sao Paulo, SP (Brazil). Deptartamento de Diagnostico por Imagem; Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    To evaluate tools for the fusion of images generated by tomography and structural and functional magnetic resonance imaging. Methods: Magnetic resonance and functional magnetic resonance imaging were performed while a volunteer who had previously undergone cranial tomography performed motor and somatosensory tasks in a 3-Tesla scanner. Image data were analyzed with different programs, and the results were compared. Results: We constructed a flow chart of computational processes that allowed measurement of the spatial congruence between the methods. There was no single computational tool that contained the entire set of functions necessary to achieve the goal. Conclusion: The fusion of the images from the three methods proved to be feasible with the use of four free-access software programs (OsiriX, Register, MRIcro and FSL). Our results may serve as a basis for building software that will be useful as a virtual tool prior to neurosurgery. (author)

  20. Cerebrovascular neurosurgery in evolution: the endovascular paradigm.

    Science.gov (United States)

    Sorkin, Grant C; Dumont, Travis M; Eller, Jorge L; Mokin, Maxim; Snyder, Kenneth V; Levy, Elad I; Siddiqui, Adnan H; Hopkins, L Nelson

    2014-02-01

    Endovascular technique represents an important, minimally invasive approach to treating cerebrovascular disease. In this article, we discuss the origins of endovascular neurosurgery as a discipline in the context of important technical milestones, evidence-based medicine, and future cerebrovascular neurosurgical training. Cerebrovascular neurosurgery has seen a steady, convergent evolution toward the surgeon capable of seamless incorporation of open and endovascular approaches to any complex vascular disease affecting the central nervous system. Neurosurgery must assume the leadership role in the multidisciplinary neurovascular team.

  1. Assessing the Relevancy of "Citation Classics" in Neurosurgery. Part II: Foundational Papers in Neurosurgery.

    Science.gov (United States)

    Bohl, Michael A; Turner, Jay D; Little, Andrew S; Nakaji, Peter; Ponce, Francisco A

    2017-08-01

    The second part of this study reanalyzes Ponce and Lozano's (2010) list of classics to create a new list of "foundational" articles in neurosurgery. Ponce and Lozano (2010) previously published a list of 106 neurosurgery classics, as defined by Garfield and his 400 citation criterion. We used the Web of Science citation reports to create graphs for each study showing the total citations it received as a function of time. Each graph was subjectively analyzed independently and scored as "foundational" or "classic only," based on whether the trend of citations received per year was uptrending, neutral, or downtrending. Of the 101 evaluated classics, 53 qualified as foundational. Over half of these studies were published in Journal of Neurosurgery (13), New England Journal of Medicine (12), or Lancet (5). Grading systems, randomized trials, and prospective studies were most likely to achieve foundational status. Only 30% of functional and 17% of endovascular classics qualified as foundational (compared with 100% of spine classics), suggesting that these fields are rapidly changing or less mature subspecialties still developing a foundational literature base. By assessing citation counts as a function of time, we are able to differentiate classic neurosurgical studies that are critical to modern-day practice from those that are primarily of historic interest. Given the exponential growth of literature in our field, analyses such as these will become increasingly important to both trainees and senior neurosurgeons who strive to educate themselves on the data that drive modern-day clinical decision making. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery.

    Science.gov (United States)

    Dyster, Timothy G; Mikell, Charles B; Sheth, Sameer A

    2016-01-01

    The role of neuroimaging in psychiatric neurosurgery has evolved significantly throughout the field's history. Psychiatric neurosurgery initially developed without the benefit of information provided by modern imaging modalities, and thus lesion targets were selected based on contemporary theories of frontal lobe dysfunction in psychiatric disease. However, by the end of the 20th century, the availability of structural and functional magnetic resonance imaging (fMRI) allowed for the development of mechanistic theories attempting to explain the anatamofunctional basis of these disorders, as well as the efficacy of stereotactic neuromodulatory treatments. Neuroimaging now plays a central and ever-expanding role in the neurosurgical management of psychiatric disorders, by influencing the determination of surgical candidates, allowing individualized surgical targeting and planning, and identifying network-level changes in the brain following surgery. In this review, we aim to describe the coevolution of psychiatric neurosurgery and neuroimaging, including ways in which neuroimaging has proved useful in elucidating the therapeutic mechanisms of neuromodulatory procedures. We focus on ablative over stimulation-based procedures given their historical precedence and the greater opportunity they afford for post-operative re-imaging, but also discuss important contributions from the deep brain stimulation (DBS) literature. We conclude with a discussion of how neuroimaging will transition the field of psychiatric neurosurgery into the era of precision medicine.

  3. Experimental functional realization of attribute grammar system

    Directory of Open Access Journals (Sweden)

    I. Attali

    2002-07-01

    Full Text Available In this paper we present an experimental functional realization of attribute grammar(AG system for personal computers. For AG system functioning only Turbo Prolog compiler is required. The system functioning is based on a specially elaborated metalanguage for AG description, universal syntactic and semantic constructors. The AG system provides automatic generation of target compiler (syntax--oriented software using Turbo Prolog as object language.

  4. Neurosurgery apps: novel knowledge boosters.

    Science.gov (United States)

    Tripathi, Manjul; Deo, Rama Chandra; Srivastav, Vinkle; Baby, Britty; Singh, Ramandeep; Damodaran, Natesan; Suri, Ashish

    2014-01-01

    The utilization of technology for purpose of imparting knowledge, especially in high-end branches like neurosurgery, has gained prominence in the contemporary academic scenario. The technological advancements have brought about outstanding transformation to education and patient care. The connectivity through smartphone applications (apps) has transcended the spatial and temporal limitations, thereby enabling easy access to virtually infinite storehouse of knowledge. Although there are numerous neurosurgery related apps, yet there is still a dearth of quality apps that may serve the purpose. Relevant apps were searched and evaluated on PlayStore and Apple App store, based on their content, user interface, performance, and utility in routine practice and compared with their cost, size and popularity. They were categorized into apps related to textbooks, scoring systems, patient education, operative procedures, blogs, journals, conferences and promotional. 159 relevant apps were hosted on App stores; 54.7% apps were free of cost. "Neuromind" was the most downloaded app because of its simplicity, free access and applicability. Students and practitioners prefer various apps linked to scoring systems, textbooks and operative illustrations. Apps have helped patients in better understanding of their diseases and management options. Development of web-based technologies has divided medical professionals into traditional and modernized learners. Mobile apps permit knowledge to be structured visually to facilitate its easy diffusion in the peer community. A technologically demanding branch like Neurosurgery inevitably needs innovative, cost effective apps with trust worthy content. Relevant apps have a high potential to be used as an excellent resource for effectual neurosurgical education beyond the limitations of time and place.

  5. Neurosurgery for Chronic Neuropathic Pain

    Directory of Open Access Journals (Sweden)

    Jung Y Park

    2000-01-01

    Full Text Available Neurosurgery can play a role in the management of patients with refractory chronic neuropathic pain. However, selecting patients as candidates for surgery and choosing the most appropriate surgical procedure is challenging, and surgical interventions often have limited efficacy. When considering surgery, neuroaugmentative or neuromodulative procedures (eg, peripheral, spinal, motor cortex or deep brain stimulation are generally preferred over ablative procedures as initial modalities. With better understanding of specific pain mechanisms, surgery will have more to offer patients with chronic neuropathic pain.

  6. NEUROSURGERY

    African Journals Online (AJOL)

    . 37. • Passenger. 13. • Ejection from the cargo area of a open pick-up truck. 10. Falls. 57. 38. Assault. 20. 13.4. Bicycle accidents. 6. 4. Object falling on the head. 5. 3.3. Child abuse. 2. 1.3. *RTC= road traffic crashes. Table 2: CT scan findings.

  7. NEUROSURGERY

    African Journals Online (AJOL)

    % for. DSC. Hospital mortality for NO was 33% versus 6% for DSC. Wound infection occurred in. NO in 46% versus 10% for DSC. At 2 years in NO, there were no survivors versus 52 surviving children in DSC. This study suggests treatment by ...

  8. Renaissance Neurosurgery: Italy's Iconic Contributions.

    Science.gov (United States)

    Nanda, Anil; Khan, Imad Saeed; Apuzzo, Michael L

    2016-03-01

    Various changes in the sociopolitical milieu of Italy led to the increasing tolerance of the study of cadavers in the late Middle Ages. The efforts of Mondino de Liuzzi (1276-1326) and Guido da Vigevano (1280-1349) led to an explosion of cadaver-centric studies in centers such as Bologna, Florence, and Padua during the Renaissance period. Legendary scientists from this era, including Leonardo Da Vinci, Andreas Vesalius, Bartolomeo Eustachio, and Costanzo Varolio, furthered the study of neuroanatomy. The various texts produced during this period not only helped increase the understanding of neuroanatomy and neurophysiology but also led to the formalization of medical education. With increased understanding came new techniques to address various neurosurgical problems from skull fractures to severed peripheral nerves. The present study aims to review the major developments in Italy during the vibrant Renaissance period that led to major progress in the field of neurosurgery. Published by Elsevier Inc.

  9. [Stereotactic target identification for neurosurgery of Parkinson disease].

    Science.gov (United States)

    Fernández-González, F; Seijo, F; Menéndez-Guisasola, L; Salvador, C; Roger, R L; González-García, F J; Fernández-Martínez, J M; Bulla, B; Fernández-García, C; González-González, S; Galindo, A

    The use of applied neurophysiological methods to improve the stereotactic localization of devices in the deep human brain is a high and systematic technology in Parkinson's neurosurgery today. The available standard equipment for clinical neurophysiology practice may constitute the basic set for high tech functional neurosurgery. Free run and event related multiunit recording, naturalistic and electrical evoked potentials, and deep brain microstimulation responses are the basic methodological set to neurophysiological target localization. This article is concerned with the topic: set out a high technology using low cost equipment. So our 41 cases experienced in pallidal and thalamic nucleolisis and thalamus and subthalamus DBS results suggest that the proposed equipment and methods are the required to assure accuracy and safety for target location.

  10. Smartphone use in neurosurgery? APP-solutely!

    OpenAIRE

    Zaki, Michael; Drazin, Doniel

    2014-01-01

    Background: A number of smartphone medical apps have recently emerged that may be helpful for the neurosurgical patient, practitioner, and trainee. This study aims to review the current neurosurgery-focused apps available for the iPhone, iPad, and Android platforms as of December 2013. Methods: Two of the most popular smartphone app stores (Apple Store and Android Google Play Store) were surveyed for neurosurgery-focused apps in December 2013. Search results were categorized based on thei...

  11. Tracking Career Paths of Women in Neurosurgery.

    Science.gov (United States)

    Renfrow, Jaclyn J; Rodriguez, Analiz; Wilson, Taylor A; Germano, Isabelle M; Abosch, Aviva; Wolfe, Stacey Quintero

    2017-05-16

    Women represent a growing cohort of US neurosurgeons. To describe postresidency fellowship, practice environment, and updated academic rank among female neurosurgeons. Databases from the American Association of Neurological Surgeons (AANS) and the American Board of Neurological Surgery (ABNS) from 1964 to 2013 were reviewed for female neurosurgery residency graduates. Data on postresidency fellowships, practice environment (private vs academic), academic rank, board certification, and AANS/CNS (Congress of Neurological Surgeons) Joint Section on Women in Neurosurgery (WINS) membership were collected in 2016. Academic rank was verified from program websites and electronic correspondence. Faculty members were asked to report directorships and tenure. The AANS/CNS Joint Section on Women in Neurosurgery verified WINS membership. A total of 379 female neurosurgery residency graduates were identified in this 50-yr span. Of these, 70% became ABNS certified, and 2.1% left neurosurgery. Twenty-seven percent of women (n = 103) pursued fellowships, with pediatric neurosurgery (33%) the most common. Regarding practice environment, 26% entered academic medicine (n = 91), with 42 at the rank of assistant professor, 33 at the rank of associate professor, and 16 reaching the rank of full professor. Upon completion of training, 27% of women pursue fellowships. The distribution of women in private vs academic practice environments is proportionate to male neurosurgeons; however, the number women in academic leadership positions remains exceedingly low, with disproportionate representation in higher academic ranks. Women in national organized neurosurgery are increasing. Tracking the career paths of women in neurosurgery is a necessary step to identifying current achievements and opportunities for future progress.

  12. Reflections on a career in neurosurgery

    OpenAIRE

    Heimburger, Robert F.; Heimburger, Douglas C.

    2013-01-01

    Robert Heimburger recounts his career in neurosurgery, including some of the early years of modern neurosurgery and some of the contributions he made, particularly in the areas of early repair of myelomeningocele and spinal cord tethering, high-intensity focused ultrasound for the brain, stereotactic surgery, washing hair and scalps instead of shaving for cranial surgery, and neurosurgical consultation in Asian countries. Now aged 96, he continues to have a keen mind and thorough commitment t...

  13. INFORMATION SYSTEM FOR DEPARTMENT OF RECONSTRUCTIVE NEUROSURGERY

    Directory of Open Access Journals (Sweden)

    V. I. Tsymbaliuk

    2015-05-01

    Full Text Available This article is about creating information system for the rehabilitation Department of Neurosurgery. To develop the information system needs to explore the work of department, examine the medical documentation and statistical reporting forms which doctors using in their work. Determine the sequence of making records into documentation. And finally make list of requirements for application with help of medical staff. The software was developed by using C# language and the database server MySQL. It has five major systems and several ancillary subsystems. The major systems are: saving personal and clinical patient information, editing inputted data, showing data, ensuring the integrity and accuracy of database, the implementation of access to the same database from different computers. Auxiliary subsystems include: creating medical documentation, blocking form’s elements, searching for patient through database, making statistic over some period of time, creating folders for every patient and others. There was designed user interface that allows doctors to reduce time for learning functionality of application. Information system has positive effect. It saves time for medical staff and reduces the possibility of inputting wrong information. Application does not require high hardware characteristics of computer.

  14. Technological innovation in neurosurgery: a quantitative study.

    Science.gov (United States)

    Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

    2015-07-01

    Technological innovation within health care may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technology-intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical techniques. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation, respectively. The authors searched a patent database for articles published between 1960 and 2010 using the Boolean search term "neurosurgeon OR neurosurgical OR neurosurgery." The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top-performing technology cluster was then selected as an exemplar for a more detailed analysis of individual patents. In all, 11,672 patents and 208,203 publications related to neurosurgery were identified. The top-performing technology clusters during these 50 years were image-guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes, and endoscopes. In relation to image-guidance and neuromodulation devices, the authors found a highly correlated rapid rise in the numbers of patents and publications, which suggests that these are areas of technology expansion. An in-depth analysis of neuromodulation-device patents revealed that the majority of well-performing patents were related to deep brain stimulation. Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery.

  15. Patient Satisfaction and Short-Term Outcome in Elective Cranial Neurosurgery.

    Science.gov (United States)

    Reponen, Elina; Tuominen, Hanna; Hernesniemi, Juha; Korja, Miikka

    2015-11-01

    Patient-reported experience is often used as a measure for quality of care, but no reports on patient satisfaction after cranial neurosurgery exist. To study the association of overall patient satisfaction and surgical outcome and to evaluate the applicability of overall patient satisfaction as a proxy for quality of care in elective cranial neurosurgery. We conducted an observational study on the relationship of overall patient satisfaction at 30 postoperative days with surgical and functional outcome (modified Rankin Scale [mRS] score) in a prospective, consecutive, and unselected cohort of 418 adult elective craniotomy patients enrolled between December 2011 and December 2012 at Helsinki University Hospital, Helsinki, Finland. Postoperative overall (subjective and objective) morbidity was present in 194 (46.4%) patients; yet almost 94% of all study patients reported high overall satisfaction. Low overall patient satisfaction at 30 days was not associated with postoperative major morbidity in elective cranial neurosurgery. Dependent functional status (mRS score ≥3) at 30 days, minor infections, poor postoperative subjective overall health status, and patient-reported severe symptoms (double vision, poor balance) may contribute to unsatisfactory patient experience. Overall patient satisfaction with elective cranial neurosurgery is high. Even 9 of 10 patients with postoperative major morbidity rated high overall patient satisfaction at 30 days. Overall patient satisfaction may merely reflect patient experience and subjective postoperative health status, and therefore it is a poor proxy for quality of care in elective cranial neurosurgery.

  16. Simulation and resident education in spinal neurosurgery

    Science.gov (United States)

    Bohm, Parker E.; Arnold, Paul M.

    2015-01-01

    Background: A host of factors have contributed to the increasing use of simulation in neurosurgical resident education. Although the number of simulation-related publications has increased exponentially over the past two decades, no studies have specifically examined the role of simulation in resident education in spinal neurosurgery. Methods: We performed a structured search of several databases to identify articles detailing the use of simulation in spinal neurosurgery education in an attempt to catalogue potential applications for its use. Results: A brief history of simulation in medicine is given, followed by current trends of spinal simulation utilization in residency programs. General themes from the literature are identified that are integral for implementing simulation into neurosurgical residency curriculum. Finally, various applications are reported. Conclusion: The use of simulation in spinal neurosurgery education is not as ubiquitous in comparison to other neurosurgical subspecialties, but many promising methods of simulation are available for augmenting resident education. PMID:25745588

  17. Simulation and resident education in spinal neurosurgery.

    Science.gov (United States)

    Bohm, Parker E; Arnold, Paul M

    2015-01-01

    A host of factors have contributed to the increasing use of simulation in neurosurgical resident education. Although the number of simulation-related publications has increased exponentially over the past two decades, no studies have specifically examined the role of simulation in resident education in spinal neurosurgery. We performed a structured search of several databases to identify articles detailing the use of simulation in spinal neurosurgery education in an attempt to catalogue potential applications for its use. A brief history of simulation in medicine is given, followed by current trends of spinal simulation utilization in residency programs. General themes from the literature are identified that are integral for implementing simulation into neurosurgical residency curriculum. Finally, various applications are reported. The use of simulation in spinal neurosurgery education is not as ubiquitous in comparison to other neurosurgical subspecialties, but many promising methods of simulation are available for augmenting resident education.

  18. Experimental Fracture Measurements of Functionally Graded Materials

    Science.gov (United States)

    Carpenter, Ray Douglas

    The primary objective of this research was to extend established fracture toughness testing methods to a new class of engineering materials known as functionally graded materials (FGMs). Secondary goals were to compare experimental results to those predicted by finite element models and to provide fracture test results as feedback toward optimizing processing parameters for the in-house synthesis of a MoSi2/SiC FGM. Preliminary experiments were performed on commercially pure (CP) Ti and uniform axial tensile tests resulted in mechanical property data including yield strength, 268 MPa, ultimate tensile strength, 470 MPa and Young's modulus, 110 GPa. Results from 3-point bending fracture experiments on CP Ti demonstrated rising R-curve behavior and experimentally determined JQ fracture toughness values ranged between 153 N/mm and 254 N/mm. Similar experimental protocols were used for fracture experiments on a 7- layered Ti/TiB FGM material obtained from Cercom in Vista, California. A novel technique for pre-cracking in reverse 4-point bending was developed for this ductile/brittle FGM material. Fracture test results exhibited rising R-curve behavior and estimated JQ fracture toughness values ranged from 0.49 N/mm to 2.63 N/mm. A 5- layered MoSi2/SiC FGM was synthesized using spark plasma sintering (SPS). Samples of this material were fracture tested and the results again exhibited a rising R-curve with KIC fracture toughness values ranging from 2.7 MPa-m1/2 to 6.0 MPa-m1/2. Finite Element Models predicted rising R-curve behavior for both of the FGM materials tested. Model results were in close agreement for the brittle MoSi2/SiC FGM. For the relatively more ductile Ti/TiB material, results were in close agreement at short crack lengths but diverged at longer crack lengths because the models accounted for fracture toughening mechanisms at the crack tip but not those acting in the crack wake.

  19. The future of neurosurgery: a white paper on the recruitment and retention of women in neurosurgery.

    Science.gov (United States)

    Benzil, Deborah L; Abosch, Aviva; Germano, Isabelle; Gilmer, Holly; Maraire, J Nozipo; Muraszko, Karin; Pannullo, Susan; Rosseau, Gail; Schwartz, Lauren; Todor, Roxanne; Ullman, Jamie; Zusman, Edie

    2008-09-01

    The leadership of Women in Neurosurgery (WINS) has been asked by the Board of Directors of the American Association of Neurological Surgeons (AANS) to compose a white paper on the recruitment and retention of female neurosurgical residents and practitioners. Neurosurgery must attract the best and the brightest. Women now constitute a larger percentage of medical school classes than men, representing approximately 60% of each graduating medical school class. Neurosurgery is facing a potential crisis in the US workforce pipeline, with the number of neurosurgeons in the US (per capita) decreasing. The number of women entering neurosurgery training programs and the number of board-certified female neurosurgeons is not increasing. Personal anecdotes demonstrating gender inequity abound among female neurosurgeons at every level of training and career development. Gender inequity exists in neurosurgery training programs, in the neurosurgery workplace, and within organized neurosurgery. The consistently low numbers of women in neurosurgery training programs and in the workplace results in a dearth of female role models for the mentoring of residents and junior faculty/practitioners. This lack of guidance contributes to perpetuation of barriers to women considering careers in neurosurgery, and to the lack of professional advancement experienced by women already in the field. There is ample evidence that mentors and role models play a critical role in the training and retention of women faculty within academic medicine. The absence of a critical mass of female neurosurgeons in academic medicine may serve as a deterrent to female medical students deciding whether or not to pursue careers in neurosurgery. There is limited exposure to neurosurgery during medical school. Medical students have concerns regarding gender inequities (acceptance into residency, salaries, promotion, and achieving leadership positions). Gender inequity in academic medicine is not unique to neurosurgery

  20. Quantum computing: a prime modality in neurosurgery's future.

    Science.gov (United States)

    Lee, Brian; Liu, Charles Y; Apuzzo, Michael L J

    2012-11-01

    With each significant development in the field of neurosurgery, our dependence on computers, small and large, has continuously increased. From something as mundane as bipolar cautery to sophisticated intraoperative navigation with real-time magnetic resonance imaging-assisted surgical guidance, both technologies, however simple or complex, require computational processing power to function. The next frontier for neurosurgery involves developing a greater understanding of the brain and furthering our capabilities as surgeons to directly affect brain circuitry and function. This has come in the form of implantable devices that can electronically and nondestructively influence the cortex and nuclei with the purpose of restoring neuronal function and improving quality of life. We are now transitioning from devices that are turned on and left alone, such as vagus nerve stimulators and deep brain stimulators, to "smart" devices that can listen and react to the body as the situation may dictate. The development of quantum computers and their potential to be thousands, if not millions, of times faster than current "classical" computers, will significantly affect the neurosciences, especially the field of neurorehabilitation and neuromodulation. Quantum computers may advance our understanding of the neural code and, in turn, better develop and program implantable neural devices. When quantum computers reach the point where we can actually implant such devices in patients, the possibilities of what can be done to interface and restore neural function will be limitless. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Frameless image-guided neurosurgery in motion

    NARCIS (Netherlands)

    Woerdeman, P.A.|info:eu-repo/dai/nl/304818844

    2008-01-01

    The general objective of this thesis was the enhancement of image-guidance system use by optimizing “man-machine” interaction in frameless image-guided neurosurgery. Part I. The application of frameless stereotaxy in the neurosurgical practice We aimed to compare three patient-to-image registration

  2. A relational database in neurosurgery.

    Science.gov (United States)

    Sicurello, F; Marchetti, M R; Cazzaniga, P

    1995-01-01

    This paper describes teh automatic procedure for a clinical record management in a Neurosurgery ward. The automated record allows the storage, querying and effective management of clinical data. This is useful during the patient stay and also for data processing and analysis aiming at clinical research and statistical studies. The clinical record is problem-oriented. It contains a minimum data set regarding every patient and a data set which is defined by a classification nomenclature (using an inner protocol). The main parts of the clinical record are the following tables: PERSONAL DATA: contains the fields relating to personal and admission data of the patient. The compilation of some fields is compulsory because they serve as input for the automated discharge letter. This table is used as an identifier for patient retrieval. composed of five different tables according to the kind of data. They are: familiar anamnesis, physiological anamnesis, past and next pathology anamnesis, and trauma anamnesis. GENERAL OBJECTIVITY: contains the general physical information of a patient. The field hold default values, which quickens the compilation and assures the recording of normal values. NEUROLOGICAL EXAMINATION: contains information about the neurological status of the patient. Also in this table, ther are default values in the fields. COMA: contains standardized ata and classifications. The multiple choices are automated and driven and belong to homogeneous classes. SURGICAL OPERATIONS: the information recording is made defining the general kind of operation and then defining the peculiar kind of operation. INSTRUMENTAL EXAMINATIONS: some examination results are recorded in a free structure, while other ones (TAC, etc.) follow codified structure. In order to identify a pathology by means of TAC, it is enough to record three values corresponding to three variables. THis classification fully describes a lot of neurosurgical pathologies. DISCHARGE: contains conclusions

  3. Curriculum-based neurosurgery digital library.

    Science.gov (United States)

    Langevin, Jean-Philippe; Dang, Thai; Kon, David; Sapo, Monica; Batzdorf, Ulrich; Martin, Neil

    2010-11-01

    Recent work-hour restrictions and the constantly evolving body of knowledge are challenging the current ways of teaching neurosurgery residents. To develop a curriculum-based digital library of multimedia content to face the challenges in neurosurgery education. We used the residency program curriculum developed by the Congress of Neurological Surgeons to structure the library and Microsoft Sharepoint as the user interface. This project led to the creation of a user-friendly and searchable digital library that could be accessed remotely and throughout the hospital, including the operating rooms. The electronic format allows standardization of the content and transformation of the operating room into a classroom. This in turn facilitates the implementation of a curriculum within the training program and improves teaching efficiency. Future work will focus on evaluating the efficacy of the library as a teaching tool for residents.

  4. Minimalism in Art, Medical Science and Neurosurgery.

    Science.gov (United States)

    Okten, Ali Ihsan

    2018-01-01

    The word "minimalism" is a word derived from French the word "minimum". Whereas the lexical meaning of minimum is "the least or the smallest quantity necessary for something", its expression in mathematics can be described as "the lowest step a variable number can descend, least, minimal". Minimalism, which advocates an extreme simplicity of the artistic form, is a current in modern art and music whose origins go to 1960s and which features simplicity and objectivity. Although art, science and philosophy are different disciplines, they support each other from time to time, sometimes they intertwine and sometimes they copy each other. A periodic schools or teaching in one of them can take the others into itself, so, they proceed on their ways empowering each other. It is also true for the minimalism in art and the minimal invasive surgical approaches in science. Concepts like doing with less, avoiding unnecessary materials and reducing the number of the elements in order to increase the effect in the expression which are the main elements of the minimalism in art found their equivalents in medicine and neurosurgery. Their equivalents in medicine or neurosurgery have been to protect the physical integrity of the patient with less iatrogenic injury, minimum damage and the same therapeutic effect in the most effective way and to enable the patient to regain his health in the shortest span of time. As an anticipation, we can consider that the minimal approaches started by Richard Wollheim and Barbara Rose in art and Lars Leksell, Gazi Yaşargil and other neurosurgeons in neurosurgery in the 1960s are the present day equivalents of the minimalist approaches perhaps unconsciously started by Kazimir Malevich in art and Victor Darwin L"Espinasse in neurosurgery in the early 1900s. We can also consider that they have developed interacting with each other, not by chance.

  5. [The origins of the French neurosurgery].

    Science.gov (United States)

    Brunon, J

    2016-06-01

    Modern French neurosurgery starts at the beginning of the XXth century under the motivation of Joseph Babinski. He submitted his patients to Thierry de Martel who had learned this new specialized area of medicine with H. Cushing in the États-Unis and V. Horsey in Great Britain. His first successfully treated case of an intracranial tumor was published in 1909. But the true founding father was Clovis Vincent, initially a neurologist and collaborator of de Martel, who became the first chairman in 1933 of the neurosurgical department at the Pitié hospital of Paris and the first professor of neurosurgery in 1938. After the Second World War, many departments were created outside of Paris. Neurosurgery was definitively recognized as a specialized area in medicine in 1948. Currently, more than 400 neurosurgeons work in France. Because I had the very great privilege to be present at the birth of this society in 1970 and to still be in contact with some of the second and third generation of French neurosurgeons who led it to its high international recognition, the Chairman of the French Neurosurgical Society asked me to write this short historical vignette. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. The functions of language: an experimental study.

    Science.gov (United States)

    Redhead, Gina; Dunbar, R I M

    2013-08-14

    We test between four separate hypotheses (social gossip, social contracts, mate advertising and factual information exchange) for the function(s) of language using a recall paradigm. Subjects recalled the social content of stories (irrespective of whether this concerned social behavior, defection or romantic events) significantly better than they did ecological information. Recall rates were no better on ecological stories if they involved flamboyant language, suggesting that, if true, Miller's "Scheherazade effect" may not be independent of content. One interpretation of these results might be that language evolved as an all-purpose social tool, and perhaps acquired specialist functions (sexual advertising, contract formation, information exchange) at a later date through conventional evolutionary windows of opportunity.

  7. The Functions of Language: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Gina Redhead

    2013-10-01

    Full Text Available We test between four separate hypotheses (social gossip, social contracts, mate advertising and factual information exchange for the function(s of language using a recall paradigm. Subjects recalled the social content of stories (irrespective of whether this concerned social behavior, defection or romantic events significantly better than they did ecological information. Recall rates were no better on ecological stories if they involved flamboyant language, suggesting that, if true, Miller's “Scheherazade effect” may not be independent of content. One interpretation of these results might be that language evolved as an all-purpose social tool, and perhaps acquired specialist functions (sexual advertising, contract formation, information exchange at a later date through conventional evolutionary windows of opportunity.

  8. Considerations Related to Interpolation of Experimental Data Using Piecewise Functions

    Directory of Open Access Journals (Sweden)

    Stelian Alaci

    2016-12-01

    Full Text Available The paper presents a method for experimental data interpolation by means of a piecewise function, the points where the form of the function changes being found simultaneously with the other parameters utilized in an optimization criterion. The optimization process is based on defining the interpolation function using a single expression founded on the Heaviside function and regarding the optimization function as a generalised infinitely derivable function. The exemplification of the methodology is made via a tangible example.

  9. Publication patterns of comparative effectiveness research in spine neurosurgery.

    Science.gov (United States)

    Hueng, Dueng-Yuan; Tsai, Chia-Lin; Hsu, Shih-Wei; Ma, Hsin-I

    2012-07-01

    The purpose of this study was to investigate publication patterns for comparative effectiveness research (CER) on spine neurosurgery. The authors searched the PubMed database for the period 1980-2012 using the key words "cost analysis," "utility analysis," "cost-utility," "outcomes research," "practical clinical research," "comparator trial," and "comparative effectiveness research," linked with "effectiveness" and "spine neurosurgery." From 1980 through April 9, 2012, neurosurgery CER publications accounted for 1.38% of worldwide CER publications (8657 of 626,330 articles). Spine neurosurgery CER accounted for only 0.02%, with 132 articles. The journal with the greatest number of publications on spine neurosurgery CER was Spine, followed by the Journal of Neurosurgery: Spine. The average annual publication rate for spine neurosurgery CER during this period was 4 articles (132 articles in 33 years), with 68 (51.52%) of the 132 articles being published within the past 5 years and a rising trend beginning in 2008. The top 3 contributing countries were the US, Turkey, and Japan, with 68, 8, and 7 articles, respectively. Only 8 regular articles (6.06%) focused on cost analysis. There is a paucity of publications using CER methodology in spine neurosurgery. Few articles address the issue of cost analysis. The promotion of continuing medical education in CER methodology is warranted. Further investigations to address cost analysis in comparative effectiveness studies of spine neurosurgery are crucial to expand the application of CER in public health.

  10. [Perceived quality in hospitals of the Andalusia Healthcare System. The case of neurosurgery departments].

    Science.gov (United States)

    Cordero Tous, N; Horcajadas Almansa, Á; Bermúdez González, G J; Tous Zamora, D

    2014-01-01

    To analyse the characteristics of the perceived quality in hospitals of the Andalusia healthcare system and compare this with that in Andalusian Neurosurgery departments. Randomised surveys, adjusted for working age, were performed in Andalusia using a telephone questionnaire based on the SERVQUAL model with the appropriate modification, with the subsequent selection of a subgroup associated with neurosurgery. Perceived quality was classified as; technical, functional and infrastructure quality. The overall satisfaction was 76.3%. Frequency analysis found that variables related to the technical quality (good doctors, successful operations, trained staff, etc.) obtained more favourable outcomes. Those related to time (wait, consulting, organizing schedules) obtained worse outcomes. The care of families variables obtained poor results. There was no difference between the overall Andalusian healthcare system and neurosurgery departments. In the mean analysis, women and older people gave more favourable responses, especially for variables related to infrastructure quality. In the "cluster" analysis, there were more favourable responses by elderly people, with no differences in gender (P<.009). There is no difference in perceived quality between the Andalusian healthcare system overall and neurosurgery departments. The perceived quality of the Andalusian healthcare system is higher in the elderly people. The analysis of perceived quality is useful for promoting projects to improve clinical management. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.

  11. Obedience as a function of experimenter competence.

    Science.gov (United States)

    Penner, L A; Hawkins, H L; Dertke, M C; Spector, P; Stone, A

    1973-09-01

    The purpose of this study was to investigate obedience to an E's commands as a function of E competency. Based upon Orne's (1962, 1969) discussion of the demand characteristics inherent in the typical aggression study, it was hypothesized that E incompetence would decrease S obedience. Competence was manipulated by: (1) presenting some Ss with a nervous and inexperienced E, and (2)"accidentally" killing the victim (a rat) midway through the experiment. Thirty-two undergraduate female Ss participated in the experiment-supposedly a study on the physiological effects of stress. Obedi6nce was operationalized as the difference, in simple reaction time, between trials on which Ss were told that their response might result in shock to the rat and trials on which they were told that their response might save the rat from shock. Significant differences in obedience were obtained between competent and incompetent E conditions, and a significant "kill" effect was found in the competent E conditidn. The results of this study suggested that the extreme acts of obedience observed in the laboratory (e.g., Milgram, 1963) occur only when E is perceived as competent. This finding imposes limits on the generalizability of laboratory studies of obedience.

  12. Smartphone use in neurosurgery? APP-solutely!

    Science.gov (United States)

    Zaki, Michael; Drazin, Doniel

    2014-01-01

    A number of smartphone medical apps have recently emerged that may be helpful for the neurosurgical patient, practitioner, and trainee. This study aims to review the current neurosurgery-focused apps available for the iPhone, iPad, and Android platforms as of December 2013. Two of the most popular smartphone app stores (Apple Store and Android Google Play Store) were surveyed for neurosurgery-focused apps in December 2013. Search results were categorized based on their description page. Data were collected on price, rating, app release date, target audience, and medical professional involvement in app design. A review of the top apps in each category was performed. The search resulted in 111 unique apps, divided into these 7 categories: 16 (14%) clinical tools, 17 (15%) conference adjunct, 27 (24%) education, 18 (16%) literature, 15 (14%) marketing, 10 (9%) patient information, and 8 (7%) reference. The average cost of paid apps was $23.06 (range: $0.99-89.99). Out of the 111 apps, 71 (64%) were free, 48 (43%) had reviews, and 14 (13%) had more than 10 reviews. Seventy-three (66%) apps showed evidence of medical professional involvement. The number of apps being released every year has been increasing since 2009. There are a number of neurosurgery-themed apps available to all audiences. There was a lack of patient information apps for nonspinal procedures. Most apps did not have enough reviews to evaluate their quality. There was also a lack of oversight to validate the accuracy of medical information provided in these apps.

  13. Hippocrates' influence on the origins of neurosurgery.

    Science.gov (United States)

    Chang, Anna; Lad, Eleonora M; Lad, Shivanand P

    2007-01-01

    Hippocrates is widely considered the father of medicine. His contributions revolutionized the practice of medicine and laid the foundation for modern-day neurosurgery. He inspired several generations to follow his vision, by pioneering the rigorous clinical evaluation of cranial and spinal disorders and combining this approach with a humanistic and ethical perspective focused on the individuality of the patient. His legacy has forever shaped the field of medicine and his cumulative works on head injuries and spinal deformities led to the basic understanding of many of the fundamental neurosurgical principles in use today.

  14. Genealogy of training in vascular neurosurgery.

    Science.gov (United States)

    Chowdhry, Shakeel A; Spetzler, Robert F

    2014-02-01

    Remarkable advances and changes in the landscape of neurovascular disease have occurred recently. Concurrently, a paradigm shift in training and resident education is underway. This crossroad of unique opportunities and pressures necessitates creative change in the training of future vascular neurosurgeons to allow incorporation of surgical advances, new technology, and supplementary treatment modalities in a setting of reduced work hours and increased public scrutiny. This article discusses the changing landscape in neurovascular disease treatment, followed by the recent changes in resident training, and concludes with our view of the future of training in vascular neurosurgery.

  15. Management of hyperglycemia in the neurosurgery patient.

    Science.gov (United States)

    Daniel, Rene; Villuri, Satya; Furlong, Kevin

    2017-10-01

    Hyperglycemia is associated with adverse outcomes in patients who are candidates for or underwent neurosurgical procedures. Specific concerns and settings that relate to these patients are preoperative glycemic control, intraoperative control, management in the neurological intensive care unit (NICU), and postoperative control. In each of these settings, physicians have to ensure appropriate glycemic control to prevent or minimize adverse events. The glycemic control is usually managed by a neurohospitalist in co-management with the neurosurgery team pre- and post-operatively, and by the neurocritical care team in the setting of NICU. In this review article, we outline current standards of care for neurosurgery patients with diabetes mellitus and/or and hyperglycemia and discuss results of most recent clinical trials. We highlight specific concerns with regards to glycemic controls in these patients including enteral tube feeding and parenteral nutrition, the issues of the transition to the outpatient care, and management of steroid-induced hyperglycemia. We also note lack of evidence in some important areas, and the need for more research addressing these gaps. Where possible, we provide suggestions how to manage these patients when there is no underlying guideline.

  16. Experimental generation of Bessel-Gauss coherence functions

    Science.gov (United States)

    Reddy, Salla Gangi; Singh, R. P.; Miyamoto, Yoko

    2017-04-01

    We experimentally generate the Bessel-Gauss coherence functions using the cross-correlations between the two speckle patterns obtained using the perfect optical vortices (POV) of different orders. POV beams are generated using the Fourier transform of Bessel-Gauss beams by displaying the axicon hologram on spatial light modulator. A ground glass plate is used for scattering POV beams and the speckles are recorded. The cross-correlation function of two speckle patterns is Bessel-Gauss functions whose order is given by the difference in the orders of two POV beams used for scattering. The auto-correlation function of these speckles is Bessel-Gauss function of order zero.

  17. The Prevalence of Burnout Among US Neurosurgery Residents.

    Science.gov (United States)

    Shakir, Hakeem J; McPheeters, Matthew J; Shallwani, Hussain; Pittari, Joseph E; Reynolds, Renée M

    2017-10-27

    Burnout is a syndrome of emotional exhaustion, depersonalization, and reduced personal accomplishment. Its prevalence among US physicians exceeds 50% and is higher among residents/fellows. This is important to the practice of neurosurgery, as burnout is associated with adverse physical health, increased risk of substance abuse, and increased medical errors. To date, no study has specifically addressed the prevalence of burnout among neurosurgery residents. To determine and compare the prevalence of burnout among US neurosurgery residents with published rates for residents/fellows and practicing physicians from other specialties. We surveyed 106 US neurosurgery residency training programs to perform a descriptive analysis of the prevalence of burnout among residents. Data on burnout among control groups were used to perform a cross-sectional analysis. Nonparametric tests assessed differences in burnout scores among neurosurgery residents, and the 2-tailed Fisher's exact test assessed burnout between neurosurgery residents and control populations. Of approximately 1200 US neurosurgery residents, 255 (21.3%) responded. The prevalence of burnout was 36.5% (95% confidence interval: 30.6%-42.7%). There was no significant difference in median burnout scores between gender (P = .836), age (P = .183), or postgraduate year (P = .963) among neurosurgery residents. Neurosurgery residents had a significantly lower prevalence of burnout (36.5%) than other residents/fellows (60.0%; P burnout than other residents/fellows and practicing physicians. The underlying causes for these findings were not assessed and are likely multifactorial. Future studies should address possible causes of these findings.

  18. The internal medicine specialist and neurosurgery

    Directory of Open Access Journals (Sweden)

    A. Pizzini

    2013-05-01

    Full Text Available BACKGROUND The neurosurgical patient is often a real challenge for the physicians, because of a frequent multimorbidity and a higher risk for severe complications. Cooperation between internal medicine specialist and neurosurgeon is essential to prevent the fatal effects of cranial and spinal injuries. The topic issues of medical interest in neurosurgery are the disorders of sodium balance, the glycemic control, the thromboembolic risk, the intracerebral bleeding management and the infective problems. The neurosurgeons could be worried by treating these complications that are mostly of internal medicine interest and that could unfortunately rise the risk of death or irreversible insults. AIM OF THE REVIEW This review summarizes the modality of diagnosis and therapy of the foremost concerns in neurosurgical field.

  19. Overview of intraoperative MRI in neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Shiino, Akihiko; Matsuda, Masayuki [Shiga Univ. of Medical Science, Otsu (Japan)

    2002-01-01

    This review describes usefulness, prospect and present problems of intraoperative MRI in neurosurgery. MRI equipments for the surgery have to have a wide, open space and have those magnets of short cylindrical, biplanar (clam shell), dual air core superconducting solenoidal (double doughnut) and targeted FOV (field of view) type. Devices required for the surgery are specific and in author's facility, they are classified into 4 zones depending on the region of their use. Application of the surgery involves biopsy, drainage of cyst and abscess, hematoma evacuation, nerve block, thermotherapy (interstitial laser, RF ablation, focused untrasonic and cryosurgery), local drug therapy, chemoablation, vascular intervention and tumor extraction, of which actual procedures and pictures are presented together with, in particular, MR-guided thermotherapy, ablation therapy of brain tumors, endoscopic surgery and minimally invasive therapy of the spine. A navigation software, 3D SlicerTM system, is introduced for interventional imaging. Safety measures are emphasized for the operation. (K.H.)

  20. Evidence for the use of preoperative risk assessment scores in elective cranial neurosurgery: a systematic review of the literature.

    Science.gov (United States)

    Reponen, Elina; Tuominen, Hanna; Korja, Miikka

    2014-08-01

    neurosurgery. It appears, however, that the patient's preoperative physical and functional status can be used to predict the short- and long-term outcome in elective cranial neurosurgery.

  1. an unusual self-damaging behavior mandating neurosurgery

    African Journals Online (AJOL)

    3. Neurosurgery related cases of Munchausen's syndrome generally involve chronic back pain4, post- surgery Munchausen's syndrome5, or head trauma and intracranial hemorrhage.6 These patients spend most of their lives in hospitals with ...

  2. Experimental manipulation of infant temperament affects amygdala functional connectivity

    NARCIS (Netherlands)

    Hendricx-Riem, M.M.E.; Van Ijzendoorn, M.H.; Parsons, C.E.; Young, K.S.; De Carli, P.; Kringelbach, M.L.; Bakermans-Kranenburg, M. J.

    2017-01-01

    In this functional magnetic resonance imaging (fMRI) study we examined neural processing of infant faces associated with a happy or a sad temperament in nulliparous women. We experimentally manipulated adult perception of infant temperament in a probabilistic learning task. In this task,

  3. Medieval neurosurgery: contributions from the Middle East, Spain, and Persia.

    Science.gov (United States)

    Rahimi, Scott Y; McDonnell, Dennis E; Ahmadian, Amir; Vender, John R

    2007-01-01

    Modern neurological and spinal surgical techniques have been developed on the foundations established by predecessors. Modern 21st century neurosurgery begins in the Babylonian period, with the Edwin Smith papyrus. Throughout history, periods of enlightenment have resulted in advances in knowledge and understanding that have served as stepping stones for generations to come. As in other fields, in neurosurgery these periods of "enlightenment" have occurred in a variety of civilizations and time periods.

  4. Studying Behaviors Among Neurosurgery Residents Using Web 2.0 Analytic Tools.

    Science.gov (United States)

    Davidson, Benjamin; Alotaibi, Naif M; Guha, Daipayan; Amaral, Sandi; Kulkarni, Abhaya V; Lozano, Andres M

    2017-06-02

    Web 2.0 technologies (e.g., blogs, social networks, and wikis) are increasingly being used by medical schools and postgraduate training programs as tools for information dissemination. These technologies offer the unique opportunity to track metrics of user engagement and interaction. Here, we employ Web 2.0 tools to assess academic behaviors among neurosurgery residents. We performed a retrospective review of all educational lectures, part of the core Neurosurgery Residency curriculum at the University of Toronto, posted on our teaching website (www.TheBrainSchool.net). Our website was developed using publicly available Web 2.0 platforms. Lecture usage was assessed by the number of clicks, and associations were explored with lecturer academic position, timing of examinations, and lecture/subspecialty topic. The overall number of clicks on 77 lectures was 1079. Most of these clicks were occurring during the in-training examination month (43%). Click numbers were significantly higher on lectures presented by faculty (mean = 18.6, standard deviation ± 4.1) compared to those delivered by residents (mean = 8.4, standard deviation ± 2.1) (p = 0.031). Lectures covering topics in functional neurosurgery received the most clicks (47%), followed by pediatric neurosurgery (22%). This study demonstrates the value of Web 2.0 analytic tools in examining resident study behavior. Residents tend to "cram" by downloading lectures in the same month of training examinations and display a preference for faculty-delivered lectures. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  5. Bulgarian military neurosurgery: from Warsaw Pact to the North Atlantic Treaty Organization.

    Science.gov (United States)

    Enchev, Yavor; Eftimov, Tihomir

    2010-05-01

    After 45 years as a closest ally of the Soviet Union in the Warsaw Pact, founded mainly against the US and the Western Europe countries, and 15 years of democratic changes, since 2004 Bulgaria has been a full member of NATO and an equal and trusted partner of its former enemies. The unprecedented transformation has affected all aspects of the Bulgarian society. As a function of the Bulgarian Armed Forces, Bulgarian military medicine and in particular Bulgarian military neurosurgery is indivisibly connected with their development. The history of Bulgarian military neurosurgery is the history of the transition from the Union of Soviet Socialist Republics military system and military medicine to NATO standards in every aspect. The career of the military neurosurgeon in Bulgaria is in many ways similar to that of the civilian neurosurgeon, but there are also many peculiarities. The purpose of this study was to outline the background and the history of Bulgarian military neurosurgery as well as its future trends in the conditions of world globalization.

  6. Neurosurgery and brain shift: review of the state of the art and main contributions of robotics

    Directory of Open Access Journals (Sweden)

    Karin Correa-Arana

    2017-09-01

    Full Text Available This paper presents a review about neurosurgery, robotic assistants in this type of procedure, and the approach to the problem of brain tissue displacement, including techniques for obtaining medical images. It is especially focused on the phenomenon of brain displacement, commonly known as brain shift, which causes a loss of reference between the preoperative images and the volumes to be treated during image-guided surgery. Hypothetically, with brain shift prediction and correction for the neuronavigation system, minimal invasion trajectories could be planned and shortened. This would reduce damage to functional tissues and possibly lower the morbidity and mortality in delicate and demanding medical procedures such as the removal of a brain tumor. This paper also mentions other issues associated with neurosurgery and shows the way robotized systems have helped solve these problems. Finally, it highlights the future perspectives of neurosurgery, a branch of medicine that seeks to treat the ailments of the main organ of the human body from the perspective of many disciplines.

  7. The Preferred Learning Styles of Neurosurgeons, Neurosurgery Residents, and Neurology Residents: Implications in the Neurosurgical Field.

    Science.gov (United States)

    Lai, Hung-Yi; Lee, Ching-Yi; Chiu, Angela; Lee, Shih-Tseng

    2014-01-01

    To delineate the learning style that best defines a successful practitioner in the field of neurosurgery by using a validated learning style inventory. The Kolb Learning Style Inventory, a validated assessment tool, was administered to all practicing neurosurgeons, neurosurgical residents, and neurology residents employed at Chang Gung Memorial Hospital, an institution that provides primary and tertiary clinical care in 3 locations, Linkou, Kaohsiung, and Chiayi. There were 81 participants who entered the study, and all completed the study. Neurosurgeons preferred the assimilating learning style (52%), followed by the diverging learning style (39%). Neurosurgery residents were slightly more evenly distributed across the learning styles; however, they still favored assimilating (32%) and diverging (41%). Neurology residents had the most clearly defined preferred learning style with assimilating (76%) obtaining the large majority and diverging (12%) being a distant second. The assimilating and diverging learning styles are the preferred learning styles among neurosurgeons, neurosurgery residents, and neurology residents. The assimilating learning style typically is the primary learning style for neurosurgeons and neurology residents. Neurosurgical residents start off with a diverging learning style and progress toward an assimilating learning style as they work toward becoming practicing neurosurgeons. The field of neurosurgery has limited opportunities for active experimentation, which may explain why individuals who prefer reflective observation are more likely to succeed in this field. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Introduction: military neurosurgery, past and present.

    Science.gov (United States)

    Klimo, Paul; Ragel, Brian T

    2010-05-01

    For a physician has the worth of many other warriors, both for the excision of arrows and for the administration of soothing drugs. Homer, Iliad XI.514-515 Ever since armed conflict has been used as a means to settle disputes among men, there have been those who have been tasked to mend the wounds that ravage a soldier's body from the weapons of war. The Iliad portrays the pivotal 10th year of the legendary Trojan War, during which a schism in the Greek leadership prolongs the extended siege of the city of Troy. In the midst of this martial epic come the lines quoted above, quietly attesting to the value of the military physician, even under the crude conditions of the Greek Dark Age. They are uttered by Idomeneus, one of the foremost Greeks, when he is enjoining one of his comrades, Nestor, to rescue the injured Greek physician Machaon and take him back from the line to treat his wounds. He is afraid that Machaon will be captured by the Trojans, a loss far greater than that of any other single warrior. Duty to country has helped shape the careers of many neurosurgeons, including iconic US figures such as Harvey Cushing and Donald Matson. This issue of Neurosurgical Focus celebrates the rich history of military neurosurgery from the wars of yesterday to the conflicts of today. We have been humbled by the tremendous response to this topic. The 25 articles within this issue will provide the reader with both a broad and an in-depth look at the many facets of military neurosurgery. We have attempted to group articles based on their predominant topic. We also encourage our audience to read other recently published articles. The first 8 articles relate to the current conflicts in Afghanistan and Iraq. The lead article, written by Randy Bell and colleagues from the National Naval Medical Center and Walter Reed Army Medical Center, discusses what is arguably one of the most important contributions by military neurosurgeons from these 2 conflicts: the rapid and aggressive

  9. [Competency-based Neurosurgery Residency Programme].

    Science.gov (United States)

    Lobato, Ramiro D; Jiménez Roldan, Luis; Alen, José F; Castaño, Ana M; Munarriz, Pablo M; Cepeda, Santiago; Lagares, Alfonso

    2016-01-01

    A programme proposal for competency-based Neurosurgery training adapted to the specialization project is presented. This proposal has been developed by a group of neurosurgeons commissioned by the SENEC (Spanish Society of Neurosurgery) and could be modified to generate a final version that could come into force coinciding with the implementation of the specialization programme. This document aims to facilitate the test of the new programme included in the online version of our journal. Total training period is 6 years; initial 2 years belong to the surgery specialization and remaining 4 years belong to core specialty period. It is a competency-based programmed based on the map used by the US Accreditation Council for Graduate Medical Education (ACGME) including the following domains of clinical competency: Medical knowledge, patient care, communication skills, professionalism, practice-based learning and improvement, health systems, interprofessional collaboration and professional and personal development. Subcompetencies map in the domains of Knowledge and Patient care (including surgical competencies) was adapted to the one proposed by AANS and CNS (annex 1 of the programme). A subcompetency map was also used for the specialization rotations. Resident's training is based on personal study (self-learning) supported by efficient use of information sources and supervised clinical practice, including bioethical instruction, clinical management, research and learning techniques. Resident evaluation proposal includes, among other instruments, theoretical knowledge tests, objective and structured evaluation of the level of clinical competency with real or standardised patients, global competency scales, 360-degree evaluation, clinical record audits, milestones for residents progress and self-assessment (annex 2). Besides, residents periodically assess the teaching commitment of the department's neurosurgeons and other professors participating in rotations, and annually

  10. Neurosurgery of the future: Deep brain stimulations and manipulations.

    Science.gov (United States)

    Nicolaidis, Stylianos

    2017-04-01

    Important advances are afoot in the field of neurosurgery-particularly in the realms of deep brain stimulation (DBS), deep brain manipulation (DBM), and the newly introduced refinement "closed-loop" deep brain stimulation (CLDBS). Use of closed-loop technology will make both DBS and DBM more precise as procedures and will broaden their indications. CLDBS utilizes as feedback a variety of sources of electrophysiological and neurochemical afferent information about the function of the brain structures to be treated or studied. The efferent actions will be either electric, i.e. the classic excitatory or inhibitory ones, or micro-injection of such things as neural proteins and transmitters, neural grafts, implants of pluripotent stem cells or mesenchymal stem cells, and some variants of gene therapy. The pathologies to be treated, beside Parkinson's disease and movement disorders, include repair of neural tissues, neurodegenerative pathologies, psychiatric and behavioral dysfunctions, i.e. schizophrenia in its various guises, bipolar disorders, obesity, anorexia, drug addiction, and alcoholism. The possibility of using these new modalities to treat a number of cognitive dysfunctions is also under consideration. Because the DBS-CLDBS technology brings about a cross-fertilization between scientific investigation and surgical practice, it will also contribute to an enhanced understanding of brain function. Copyright © 2017. Published by Elsevier Inc.

  11. Integrating multimodal information for intraoperative assistance in neurosurgery

    Directory of Open Access Journals (Sweden)

    Eisenmann U.

    2015-09-01

    Full Text Available Computer-assisted planning of complex neurosurgical interventions benefits from a variety of specific functions and tools. However, commercial planning- and neuronavigation systems are rather restrictive concerning the availability of innovative methods such as novel imaging modalities, fiber tracking algorithms or electrical dipole mapping. In this respect there is a demand for modular neurosurgical planning systems offering flexible interfaces for easy enhancement. Furthermore all relevant planning information should be available within neuron-avigation. In this work we present a planning system providing these capabilities and its suitability and application in a clinical setting. Our Multimodal Planning System (MOPS 3D offers a variety of tools such as definition of trajectories for minimally invasive surgery, segmentation of ROIs, integration of functional information from atlas maps or magnetoencephalography. It also supplies plugin interfaces for future extensions. For intraoperative application MOPS is coupled with the neuronavigation system Brainlab Vector Vision Cranial/ENT (VVC. We evaluated MOPS in the Department of Neurosurgery at the University Hospital Heidelberg. Surgical planning and navigation was performed in 5 frequently occurring clinical cases. The time necessary for planning was between 5 and 15 minutes including data import, segmentation and planning tasks. The additional information intraoperatively provided by MOPS 3D was highly appreciated by the neurosurgeons and the performance was satisfactory.

  12. Neurosurgery in rural Nigeria: A prospective study

    Directory of Open Access Journals (Sweden)

    Taopheeq Bamidele Rabiu

    2016-01-01

    Full Text Available Background: Africa has very few neurosurgeons. These are almost exclusively in urban centers. Consequently, people in rural areas, most of the African population, have poor or no access to neurosurgical care. We have recently pioneered rural neurosurgery in Nigeria. Objectives: This report details our initial experiences and the profile of neurosurgical admissions in our center. Methods: A prospective observational study of all neurosurgical patients managed at a rural tertiary health institution in Nigeria from December 2010 to May 2012 was done. Simple descriptive data analysis was performed. Results: A total of 249 males (75.2% and 82 females (24.8% were managed. The median age was 37 years (range: Day of birth – 94 years. Trauma was the leading cause of presentation with 225 (68.0% and 35 (10.6% having sustained head and spinal injuries, respectively. Operative intervention was performed in 54 (16.3%. Twenty-four (7.2% patients discharged against medical advice, mostly for economic reasons. Most patients (208, 63.4% had satisfactory outcome while 30 (9.1% died. Conclusion: Trauma is the leading cause of rural neurosurgical presentations. There is an urgent need to improve access to adequate neurosurgical care in the rural communities.

  13. Options for perioperative pain management in neurosurgery

    Directory of Open Access Journals (Sweden)

    Vadivelu N

    2016-02-01

    Full Text Available Nalini Vadivelu,1 Alice M Kai,2 Daniel Tran,1 Gopal Kodumudi,3 Aron Legler,1 Eugenia Ayrian,4 1Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, 2Stony Brook University School of Medicine, Stony Brook, NY, 3California Northstate University College of Medicine, Elk Grove, 4Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA Abstract: Moderate-to-severe pain following neurosurgery is common but often does not get attention and is therefore underdiagnosed and undertreated. Compounding this problem is the traditional belief that neurosurgical pain is inconsequential and even dangerous to treat. Concerns about problematic effects associated with opioid analgesics such as nausea, vomiting, oversedation, and increased intracranial pressure secondary to elevated carbon dioxide tension from respiratory depression have often led to suboptimal postoperative analgesic strategies in caring for neurosurgical patients. Neurosurgical patients may have difficulty or be incapable of communicating their need for analgesics due to neurologic deficits, which poses an additional challenge. Postoperative pain control should be a priority, because pain adversely affects recovery and patient outcomes. Inconsistent practices and the quality of current analgesic strategies for neurosurgical patients still leave room for improvement. Given the complexity of postoperative pain management for these patients, multimodal strategies are often required to optimize pain control and at the same time limit undesired side effects. Keywords: acute pain, post surgical pain, post craniotomy analgesia

  14. Finite Element and Experimental Analysis of Function of Plastic Clips

    OpenAIRE

    Honarpardaz, Mohammad Mahdi

    2011-01-01

    The aim of this work is to investigate the function of plastic clips which are used to join different parts, during mounting and dismounting processes. The clips are made of POM and will be mounted on steel plates. The study is undertaken using experimental and numerical methods. In experiments, the mounting and dismounting forces are measured with respect to vertical displacement of the clips related to the plate. The numerical method is performed using structural implicit non-linear quasi-s...

  15. What can functional neuroimaging tell the experimental psychologist?

    Science.gov (United States)

    Henson, Richard

    2005-02-01

    I argue here that functional neuroimaging data--which I restrict to the haemodynamic techniques of fMRI and PET--can inform psychological theorizing, provided one assumes a "systematic" function-structure mapping in the brain. In this case, imaging data simply comprise another dependent variable, along with behavioural data, that can be used to test competing theories. In particular, I distinguish two types of inference: function-to-structure deduction and structure-to-function induction. With the former inference, a qualitatively different pattern of activity over the brain under two experimental conditions implies at least one different function associated with changes in the independent variable. With the second type of inference, activity of the same brain region(s) under two conditions implies a common function, possibly not predicted a priori. I illustrate these inferences with imaging studies of recognition memory, short-term memory, and repetition priming. I then consider in greater detail what is meant by a "systematic" function-structure mapping and argue that, particularly for structure-to-function induction, this entails a one-to-one mapping between functional and structural units, although the structural unit may be a network of interacting regions and care must be taken over the appropriate level of functional/structural abstraction. Nonetheless, the assumption of a systematic function-structure mapping is a "working hypothesis" that, in common with other scientific fields, cannot be proved on independent grounds and is probably best evaluated by the success of the enterprise as a whole. I also consider statistical issues such as the definition of a qualitative difference and methodological issues such as the relationship between imaging and behavioural data. I finish by reviewing various objections to neuroimaging, including neophrenology, functionalism, and equipotentiality, and by observing some criticisms of current practice in the imaging

  16. YouTube as a Source of Information on Neurosurgery.

    Science.gov (United States)

    Samuel, Nardin; Alotaibi, Naif M; Lozano, Andres M

    2017-09-01

    The importance of videos in social media communications in the context of health care and neurosurgery is becoming increasingly recognized. However, there has not yet been a systematic analysis of these neurosurgery-related communications. Accordingly, this study was aimed at characterizing the online video content pertaining to neurosurgery. Neurosurgery-related videos uploaded on YouTube were collected using a comprehensive search strategy. The following metrics were extracted for each video: number of views, likes, dislikes, comments, shares, date of upload, and geographic region of origin where specified. A quantitative and qualitative evaluation was performed on all videos included in the study. A total of 713 nonduplicate videos met the inclusion criteria. The overall number of views for all videos was 90,545,164. Videos were most frequently uploaded in 2016 (n = 348), with a 200% increase in uploads compared with the previous year. Of the videos that were directly relevant to clinical neurosurgery, the most frequent video categories were "educational videos" (25%), followed by "surgical and procedure overview" (20%), "promotional videos" (17%), and "patient experience" (16%). The remainder of the videos consisted primarily of unrealistic simulations of cranial surgery for entertainment purposes (20%). The findings from this study highlight the increasing use of video communications related to neurosurgery and show that institutions, neurosurgeons, and patients are using YouTube as an educational and promotional platform. As online communications continue to evolve, it will be important to harness this tool to advance patient-oriented communication and knowledge dissemination in neurosurgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Experimental Phase Functions of Millimeter-sized Cosmic Dust Grains

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, O.; Moreno, F.; Guirado, D.; Escobar-Cerezo, J. [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Vargas-Martín, F. [Department of Electromagnetism and Electronics, University of Murcia, E-30100 Murcia (Spain); Min, M. [SRON Netherlands Institute for Space Research, Sobornnelaan 2, 3584 CA Utrecht (Netherlands); Hovenier, J. W. [Astronomical Institute “Anton Pannekoek,” University of Amsterdam, Science Park 904, 1098 XH, Amsterdam (Netherlands)

    2017-09-01

    We present the experimental phase functions of three types of millimeter-sized dust grains consisting of enstatite, quartz, and volcanic material from Mount Etna, respectively. The three grains present similar sizes but different absorbing properties. The measurements are performed at 527 nm covering the scattering angle range from 3° to 170°. The measured phase functions show two well-defined regions: (i) soft forward peaks and (ii) a continuous increase with the scattering angle at side- and back-scattering regions. This behavior at side- and back-scattering regions is in agreement with the observed phase functions of the Fomalhaut and HR 4796A dust rings. Further computations and measurements (including polarization) for millimeter-sized grains are needed to draw some conclusions about the fluffy or compact structure of the dust grains.

  18. Attitudes and perceptions of medical students toward neurosurgery.

    Science.gov (United States)

    Akhigbe, Taiwo; Sattar, Mohammad

    2014-02-01

    To evaluate the attitudes and perceptions of medical student toward neurosurgery. A cross-sectional survey comprising questions based on a Likert scale was used to analyze the attitudes and perceptions of third-year, fourth-year, and fifth-year medical students from the Royal College of Surgeons in Ireland. An anonymous questionnaire containing 15 items was administered and scored following a Likert ranking scale (1, disagree; 2, agree somewhat; 3, agree moderately; 4, agree strongly). This prospective study included 60 students 20-26 years old (mean age, 23 years old). Most of the students agreed that their neurosurgery teaching is inadequate, neurosurgical history is difficult to obtain, neurosurgical signs are difficult to elicit, the neurosurgery training period is long, neurosurgical illnesses have poor outcomes, and neurosurgery can impede family life (70%-100%). The findings identify some areas that may be targeted to stimulate and improve medical students' interest and passion toward the pursuit of neurosurgery as a specialty and ultimately to improve their learning experience. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  19. Evidence-based medicine in neurosurgery: an academic publication view.

    Science.gov (United States)

    Liu, Weiming; Ni, Ming; Jia, Wang; Wan, Weiqing; Tang, Jie

    2018-01-01

    Although evidence-based medicine (EBM) has been progressively developing for decades in neurosurgery, there remains a lack of data to fully understand this topic. This study was aimed to evaluate extensively EBM related to neurosurgery through the analysis of neurosurgical EBM publications. We searched the Web of Science (WoS) Core Collection database for all EBM publications related to neurosurgery. The number of publications and other information were obtained. Data were extracted from the search results to obtain the following information: document type, countries/territories, funding agencies, organizations, publication year, source of titles, and research area. From among all of the publications, we extracted randomized controlled trials (RCTs) for further analysis at RCT characteristic and funding agencies. According to the search strategy, 6907 publications were related to EBM in neurosurgery. A total of 91 countries/territories participated in neurosurgical EBM publications. English-speaking countries (USA, England, and Canada) contributed most of the publications. "University of Toronto" is the organization which published the most EBM publications. In total, 1654 neurosurgical RCTs were found. We summarize their characteristics and record the highest cited (more than 400) RCTs, which we descript the distribution in different neurosurgical fields and stages. We also found that more than half of the RCTs were directly funded by industrial companies, and government-funded agencies accounted for no more than one fifth of the RCTs. EBM in neurosurgery has a good foundation but also needs to be constantly revised and improved to synchronize with evidence-based medicine development.

  20. Advanced registered nurse practitioners and physician assistants in the practice of pediatric neurosurgery: a clinical report.

    Science.gov (United States)

    James, Hector E; MacGregor, Teresa L; Postlethwait, Richard A; Hofrichter, Paul B; Aldana, Phillip R

    2011-01-01

    research projects. They have presented posters in a total of 9 national and 2 international meetings, and have co-authored 8 manuscripts published in peer review journals. The ARNP/PA members have been active participants in all functions of the Division of Pediatric Neurosurgery. They have facilitated the work of the faculty in day-to-day activities and enhanced the scope of divisional activities, providing a team approach for the care of the patients, families, and caretakers. Copyright © 2012 S. Karger AG, Basel.

  1. Augmented reality in neurosurgery: a systematic review.

    Science.gov (United States)

    Meola, Antonio; Cutolo, Fabrizio; Carbone, Marina; Cagnazzo, Federico; Ferrari, Mauro; Ferrari, Vincenzo

    2017-10-01

    Neuronavigation has become an essential neurosurgical tool in pursuing minimal invasiveness and maximal safety, even though it has several technical limitations. Augmented reality (AR) neuronavigation is a significant advance, providing a real-time updated 3D virtual model of anatomical details, overlaid on the real surgical field. Currently, only a few AR systems have been tested in a clinical setting. The aim is to review such devices. We performed a PubMed search of reports restricted to human studies of in vivo applications of AR in any neurosurgical procedure using the search terms "Augmented reality" and "Neurosurgery." Eligibility assessment was performed independently by two reviewers in an unblinded standardized manner. The systems were qualitatively evaluated on the basis of the following: neurosurgical subspecialty of application, pathology of treated lesions and lesion locations, real data source, virtual data source, tracking modality, registration technique, visualization processing, display type, and perception location. Eighteen studies were included during the period 1996 to September 30, 2015. The AR systems were grouped by the real data source: microscope (8), hand- or head-held cameras (4), direct patient view (2), endoscope (1), and X-ray fluoroscopy (1) head-mounted display (1). A total of 195 lesions were treated: 75 (38.46 %) were neoplastic, 77 (39.48 %) neurovascular, and 1 (0.51 %) hydrocephalus, and 42 (21.53 %) were undetermined. Current literature confirms that AR is a reliable and versatile tool when performing minimally invasive approaches in a wide range of neurosurgical diseases, although prospective randomized studies are not yet available and technical improvements are needed.

  2. Experimental research of limits for thermal modulation transfer function

    Directory of Open Access Journals (Sweden)

    Tomić Ljubiša D.

    2009-01-01

    Full Text Available The paper presented testing of surface defects by pulse video thermography techniques. Such techniques rely on transient infrared radiation from the sample heated by the short duration flux initiated by flesh. Experimental measurements are realized by infrared sensor (FLIR camera. Testing results are considered for the samples with controlled designed defects beyond observed surfaces. The effects of response through the transparent wall are measured as infrared visible radiance. Researches with controlled samples are performed to verify visibility threshold of defect dimensions and forms, for possible use as modulation transfer function of defects hidden beyond the surfaces of thin metal walls. Dimensionless coefficients are derived for method estimations as the results from experimental research.

  3. Neurosurgery in the realm of 10(-9), Part 2: applications of nanotechnology to neurosurgery--present and future.

    Science.gov (United States)

    Elder, James B; Liu, Charles Y; Apuzzo, Michael L J

    2008-02-01

    Neurosurgery in the future will witness an increasing influx of novel technologies, many of which will be based on developments in the emerging science of nanotechnology. Additionally, the continued trend in medicine toward minimally invasive diagnostic and surgical techniques will be aided by incorporation of applications of nanotechnology. Neurosurgeons of the future must facilitate the development of nanotechnology and nanomedicine in their clinical practice and research efforts to optimize patient benefit and facilitate scientific advancement. The fields of nanotechnology and nanomedicine remain in their infancy. Recently, however, the literature regarding nanoscience has rapidly expanded. This article is the second of two and provides a review of recent nanotechnology research relevant to clinical neurosurgery and neurology. The first article reviewed recent developments and issues in nanotechnology with a particular focus on applications to the neurosciences. This article also discusses current developments in nanotechnology and nanomedicine that may yield applications in neurosurgery in the future. Additional attention is given to other emerging technologies that are not truly nanotechnology, such as microelectromechanical systems, which will influence the future of medicine and neurosurgery. The goal is to provide the reader with a brief outline and description of some of the new developments in nanotechnology that may affect the clinical practice or operative experience of neurosurgeons. Continued innovation in nanotechnology presents novel opportunities for translation to the clinical arena. Neuroscience, neurology, and neurosurgery will be greatly affected by the influx of nanoscience and its applications. Through continued collaboration, physicians, scientists, and engineers will shape the futures of nanomedicine and nanoneurosurgery.

  4. Simulation in Neurosurgery-A Brief Review and Commentary.

    Science.gov (United States)

    Cobb, Mary In-Ping Huang; Taekman, Jeffrey M; Zomorodi, Ali R; Gonzalez, L Fernando; Turner, Dennis A

    2016-05-01

    Neurosurgery is one of the most technically demanding and liable of all medical professionals. More than 75% of neurosurgical errors are deemed as preventable and technical in nature. Yet in a specialty that requires such high level of technical expertise, with large consequences for error, there are even fewer opportunities for residents in training to practice on the most complicated cases. Although there is no replacement for actual experiences in the operating room, interpersonal mentorship, coaching, and training, there is room to supplement residency education through simulation. Here we review the evidence to support surgical simulation, describe the strengths and weaknesses of existing technologies in direct neurosurgery specific and indirect simulation applications, and advocate for the development of more neurosurgery-specific applications using emerging kinetic technologies. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. History of Neurosurgery in Democratic People's Republic of Korea.

    Science.gov (United States)

    Park, Kee B; Roh, Young Han; Lee-Park, Owen; Park, Sophie

    2015-09-01

    Neurosurgery in Democratic People's Republic of Korea (DPRK) has undergone remarkable progress since its beginning in the 1950s. With the initial support from socialist countries of the Soviet bloc, especially Professor Constantin Arseni of Romania, the nation has consistently produced a number of its own neurosurgeons each year and fostered further advancement by establishing the Korean Neurosurgery Association (DPRK). Despite the recent international collaborative activity for North Korean neurosurgery-namely with Foundation for International Education in Neurological Surgery, World Federation of Neurological Surgeons, and Korean American Medical Association-the sparse exchange of information, knowledge, and surgical skills still remains largely inadequate. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Functional complexity and ecosystem stability: an experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Van Voris, P.; O' Neill, R.V.; Shugart, H.H.; Emanuel, W.R.

    1978-01-01

    The complexity-stability hypothesis was experimentally tested using intact terrestrial microcosms. Functional complexity was defined as the number and significance of component interactions (i.e., population interactions, physical-chemical reactions, biological turnover rates) influenced by nonlinearities, feedbacks, and time delays. It was postulated that functional complexity could be nondestructively measured through analysis of a signal generated from the system. Power spectral analysis of hourly CO/sub 2/ efflux, from eleven old-field microcosms, was analyzed for the number of low frequency peaks and used to rank the functional complexity of each system. Ranking of ecosystem stability was based on the capacity of the system to retain essential nutrients and was measured by net loss of Ca after the system was stressed. Rank correlation supported the hypothesis that increasing ecosystem functional complexity leads to increasing ecosystem stability. The results indicated that complex functional dynamics can serve to stabilize the system. The results also demonstrated that microcosms are useful tools for system-level investigations.

  7. MINOP: development of a miniaturized endoscopic operation system for neurosurgery

    Science.gov (United States)

    Guber, Andreas E.; Wieneke, Paul

    1996-04-01

    Within the framework of R&D activities in the field of microsystems technology, the Institute for Microstructure Technology of Karlsruhe Research Center among others has started to improve the functionality of existing medicotechnical instruments by increased integration of microtechnical components. On the basis of microsystems fabrication techniques, completely novel medical endoscope systems have become feasible. In cooperation with clinical, technical and industrial partners, a novel endoscopic operation system based on microsystems technology is being developed by the Institute for Microstructure Technology and the Aesculap AG company, Tuttlingen within the framework of the MINOP joint project. This new system shall be applied above all in the field of neurosurgery. This newly conceived endosystem is characterized by a multitude of novelties. It can perform a number of both sensor and actor functions. Due to its extremely small outer diameter, it can be applied through minute openings. As a result of the integrated microfluidic control system, the flexible endoscope can be moved to the actual site of operation on a previously specified path. This will allow future bi- and triportal neuro-endoscopic interventions for critical operations in the brain area. The different lumina of the flexible endoscope fulfill various functions. Via the optical fibers, laser radiation may be led to the distal end of the endoscope. Using microtechnical fabrication methods, special plastic microlenses have been produced. The working channel can be applied for rinsing and removal. Furthermore, the cleaning of the optics or the taking of tissue samples are possible. If required, another laser fiber can be driven forward through the working channel for selective therapy. For the first time, high-performance microinstruments have been developed on the basis of novel materials. These instruments can be applied either through the working channel or through an additional trocar.

  8. Mobile pediatric neurosurgery: rapid response neurosurgery for remote or urgent pediatric patients.

    Science.gov (United States)

    Owler, Brian K; Carmo, Kathryn A Browning; Bladwell, Wendy; Fa'asalele, T Arieta; Roxburgh, Jane; Kendrick, Tina; Berry, Andrew

    2015-09-01

    Time-critical neurosurgical conditions require urgent operative treatment to prevent death or neurological deficits. In New South Wales/Australian Capital Territory patients' distance from neurosurgical care is often great, presenting a challenge in achieving timely care for patients with acute neurosurgical conditions. A protocol was developed to facilitate consultant neurosurgery locally. Children with acute, time-critical neurosurgical emergencies underwent operations in hospitals that do not normally offer neurosurgery. The authors describe the developed protocol, the outcome of its use, and the lessons learned in the 9 initial cases where the protocol has been used. Three cases are discussed in detail. Nine children were treated by a neurosurgeon at 5 rural hospitals, and 2 children were treated at a smaller metropolitan hospital. Road ambulance, fixed wing aircraft, and medical helicopters were used to transport the Newborn and Paediatric Emergency Transport Service (NETS) team, neurosurgeon, and patients. In each case, the time to definitive neurosurgical intervention was significantly reduced. The median interval from triage at the initial hospital to surgical start time was 3:55 hours, (interquartile range [IQR] 03:29-05:20 hours). The median distance traveled to reach a patient was 232 km (range 23-637 km). The median interval from the initial NETS call requesting patient retrieval to surgical start time was 3:15 hours (IQR 00:47-03:37 hours). The estimated median "time saved" was approximately 3:00 hours (IQR 1:44-3:15 hours) compared with the travel time to retrieve the child to the tertiary center: 8:31 hours (IQR 6:56-10:08 hours). Remote urgent neurosurgical interventions can be performed safely and effectively. This practice is relevant to countries where distance limits urgent access for patients to tertiary pediatric care. This practice is lifesaving for some children with head injuries and other acute neurosurgical conditions.

  9. Unsung hero: Donald Darrow Matson's legacy in pediatric neurosurgery.

    Science.gov (United States)

    Rehder, Roberta; Lohani, Subash; Cohen, Alan R

    2015-07-31

    Donald Darrow Matson made seminal contributions to the field of pediatric neurosurgery. Born in 1913 in Fort Hamilton, New York, Matson was the youngest of four sons of an army colonel. He graduated from Cornell University and, years later, from Harvard Medical School. Matson selected Peter Bent Brigham Hospital for his neurosurgical training, which was interrupted during World War II. As a neurosurgeon, he worked close to the front lines under Brigadier General Elliot Cutler in Europe, earning a Bronze Star. Matson returned to Boston to become Franc Ingraham's fellow and partner. He was a masterful surgeon and, with Ingraham, published Neurosurgery of Infancy and Childhood in 1954, the first pediatric neurosurgery textbook in the world. Upon Ingraham's retirement, Matson became chairman of the department of neurosurgery at Boston Children's Hospital and Peter Bent Brigham. In 1968, he became the inaugural Franc D. Ingraham Professor of Neurological Surgery at Harvard Medical School. Among his neurosurgical accomplishments, Matson served as President of the Harvey Cushing Society, later known as the American Association of Neurological Surgeons. He was unable to preside at the 1969 meeting that marked the 100th anniversary of Cushing's birth, having contracted Creutzfeldt-Jakob disease. Matson died at the age of 55, surviving his mentor Ingraham by only 4 years.

  10. Water balance disorders after neurosurgery: The triphasic response revisited

    NARCIS (Netherlands)

    E.J. Hoorn (Ewout); R. Zietse (Bob)

    2010-01-01

    textabstractWater balance disorders after neurosurgery are well recognized, but detailed reports of the triphasic response are scarce. We describe a 55-year-old woman, who developed the triphasic response with severe hyper- and hyponatraemia after resection of a suprasellar meningioma. The case

  11. Infectious agents and antibiotic susceptibility in neurosurgery intensive care unit

    Directory of Open Access Journals (Sweden)

    Aslan Güzel

    2009-01-01

    Full Text Available Aim: Knowing the most frequent causative agents and their sensitivities to antibiotics may contribute to use of appropriate antibiotics. In this study, we aimed to inves-tigate the agents and their antibiotic sensitivity which is isolated from intensive care unit of neurosurgery clinic.Materials and Methods: This retrospective study was performed from 2001 to 2005 at the Neurosurgery inten-sive care unit of Dicle University, Diyarbakir. The pa-tients charts who were followed up more than 48 hours in intensive care unit and their culture results were inves-tigated.Results: There was 457 of 2197 patients which were operated in neurosurgery clinic and it was obtained 1155 culture samples from these patients in five years period. 317 positive cultures were obtained from 123 patients including 73 cerebrospinal fluid, 45 wound, 47 deep tra-cheal aspirate, 96 were urine samples, 27 blood sam-ples and 29 venous catheters samples. Mostly Staphilo-coccus aureus and coagulase negative staphylococcus (CNS were growth in cultures. From the cerebrospinal fluidd, blood and wound the most growth bacteria was coagulase negative staphilococcus, from the urine Es-chericha coli, from deep tracheal aspiration. Klebsiella pnömonia, and from venous catheters Pseudomonas au-reginosa was mostly showed reproduction.Conclusion: S. aureus, CNS and P. aureginosa were mostly isolated bacteria in neurosurgery intensive care unit. Nosocomial intensive care unit infections can be decreased by appropriate preventive measures

  12. Experimental investigations of the functional morphology of dragonfly wings

    Science.gov (United States)

    Rajabi, H.; Darvizeh, A.

    2013-08-01

    Nowadays, the importance of identifying the flight mechanisms of the dragonfly, as an inspiration for designing flapping wing vehicles, is well known. An experimental approach to understanding the complexities of insect wings as organs of flight could provide significant outcomes for design purposes. In this paper, a comprehensive investigation is carried out on the morphological and microstructural features of dragonfly wings. Scanning electron microscopy (SEM) and tensile testing are used to experimentally verify the functional roles of different parts of the wings. A number of SEM images of the elements of the wings, such as the nodus, leading edge, trailing edge, and vein sections, which play dominant roles in strengthening the whole structure, are presented. The results from the tensile tests indicate that the nodus might be the critical region of the wing that is subjected to high tensile stresses. Considering the patterns of the longitudinal corrugations of the wings obtained in this paper, it can be supposed that they increase the load-bearing capacity, giving the wings an ability to tolerate dynamic loading conditions. In addition, it is suggested that the longitudinal veins, along with the leading and trailing edges, are structural mechanisms that further improve fatigue resistance by providing higher fracture toughness, preventing crack propagation, and allowing the wings to sustain a significant amount of damage without loss of strength.

  13. Multitrophic functional diversity predicts ecosystem functioning in experimental assemblages of estuarine consumers.

    Science.gov (United States)

    Lefcheck, Jonathan S; Duffy, J Emmett

    2015-11-01

    The use of functional traits to explain how biodiversity affects ecosystem functioning has attracted intense interest, yet few studies have a priori altered functional diversity, especially in multitrophic communities. Here, we manipulated multivariate functional diversity of estuarine grazers and predators within multiple levels of species richness to test how species richness and functional diversity predicted ecosystem functioning in a multitrophic food web. Community functional diversity was a better predictor than species richness for the majority of ecosystem properties, based on generalized linear mixed-effects models. Combining inferences from eight traits into a single multivariate index increased prediction accuracy of these models relative to any individual trait. Structural equation modeling revealed that functional diversity of both grazers and predators was important in driving final biomass within trophic levels, with stronger effects observed for predators. We also show that different species drove different ecosystem responses, with evidence for both sampling effects and complementarity. Our study extends experimental investigations of functional trait diversity to a multilevel food web, and demonstrates that functional diversity can be more accurate and effective than species richness in predicting community biomass in a food web context.

  14. [The reproductive function in experimentally-produced monozygotic twin bulls].

    Science.gov (United States)

    Braun, J; Schams, D; Brem, G

    1990-06-01

    Reproductive functions were evaluated in 12 experimentally derived monozygotic cattle twins (6 pairs). In 4 twin pairs GnRH (20 micrograms Receptal i.m.) was administered in monthly intervals from 6 through 12 months of age. LH-secretion was determined by radioimmunoassay up to 6 hours after the GnRH-challenge in hourly collected peripheral blood samples. In 5 twin pairs (age 14 to 20 months) semen was collected 5 times and processed for cryoconservation. In fresh and in frozen-thawed semen samples sperm motility was determined by means of a computerized system. Twins showed a remarkable uniform response to the GnRH-challenge. One set of twins (HF-breed) had a significantly reduced response compared to the other pairs (DFV-breed). Both individuals of this particular pair had a low percentage of progressively motile spermatozoa. In pairs with physiological sperm motility, variance of this parameter within pairs and between pairs was not different. In contrast, twin uniformity concerning the average velocity of motile spermatozoa was high; differences between set of twins explained most of the total variance. According to this study, reproductive parameters in monozygotic cattle twins are strongly influenced by twin uniformity.

  15. Critical Zone Experimental Design to Assess Soil Processes and Function

    Science.gov (United States)

    Banwart, Steve

    2010-05-01

    experimental design studies soil processes across the temporal evolution of the soil profile, from its formation on bare bedrock, through managed use as productive land to its degradation under longstanding pressures from intensive land use. To understand this conceptual life cycle of soil, we have selected 4 European field sites as Critical Zone Observatories. These are to provide data sets of soil parameters, processes and functions which will be incorporated into the mathematical models. The field sites are 1) the BigLink field station which is located in the chronosequence of the Damma Glacier forefield in alpine Switzerland and is established to study the initial stages of soil development on bedrock; 2) the Lysina Catchment in the Czech Republic which is representative of productive soils managed for intensive forestry, 3) the Fuchsenbigl Field Station in Austria which is an agricultural research site that is representative of productive soils managed as arable land and 4) the Koiliaris Catchment in Crete, Greece which represents degraded Mediterranean region soils, heavily impacted by centuries of intensive grazing and farming, under severe risk of desertification.

  16. Straight trajectory planning for keyhole neurosurgery in sheep with automatic brain structures segmentation

    Science.gov (United States)

    Favaro, Alberto; Lad, Akash; Formenti, Davide; Zani, Davide Danilo; De Momi, Elena

    2017-03-01

    In a translational neuroscience/neurosurgery perspective, sheep are considered good candidates to study because of the similarity between their brain and the human one. Automatic planning systems for safe keyhole neurosurgery maximize the probe/catheter distance from vessels and risky structures. This work consists in the development of a trajectories planner for straight catheters placement intended to be used for investigating the drug diffusivity mechanisms in sheep brain. Automatic brain segmentation of gray matter, white matter and cerebrospinal fluid is achieved using an online available sheep atlas. Ventricles, midbrain and cerebellum segmentation have been also carried out. The veterinary surgeon is asked to select a target point within the white matter to be reached by the probe and to define an entry area on the brain cortex. To mitigate the risk of hemorrhage during the insertion process, which can prevent the success of the insertion procedure, the trajectory planner performs a curvature analysis of the brain cortex and wipes out from the poll of possible entry points the sulci, as part of brain cortex where superficial blood vessels are naturally located. A limited set of trajectories is then computed and presented to the surgeon, satisfying an optimality criteria based on a cost function which considers the distance from critical brain areas and the whole trajectory length. The planner proved to be effective in defining rectilinear trajectories accounting for the safety constraints determined by the brain morphology. It also demonstrated a short computational time and good capability in segmenting gyri and sulci surfaces.

  17. Neurosurgery In Nigeria - An Evaluation Of The Perception Of ...

    African Journals Online (AJOL)

    Most of the respondents were females 59.1%, and most were in the 20 30 year age group, 57.3%; more than 96% stated that they have heard of neurosurgery previously, but rated the available services in Nigeria as inadequate 50.6%, and quality of services as fair 39.6% or poor 36.6%, respectively. In their opinion, political ...

  18. Three-dimensional, computer simulated navigation in endoscopic neurosurgery

    Directory of Open Access Journals (Sweden)

    Roberta K. Sefcik, BHA

    2017-06-01

    Conclusion: Three-dimensional, frameless neuronavigation systems are useful in endoscopic neurosurgery to assist in the pre-operative planning of potential trajectories and to help localize the pathology of interest. Neuronavigation appears to be accurate to <1–2 mm without issues related to brain shift. Further work is necessary in the investigation of the effect of neuronavigation on operative time, cost, and patient-centered outcomes.

  19. Simulation training in neurosurgery: advances in education and practice

    Directory of Open Access Journals (Sweden)

    Konakondla S

    2017-07-01

    Full Text Available Sanjay Konakondla, Reginald Fong, Clemens M Schirmer Department of Neurosurgery and Neuroscience Institute, Geisinger Medical Center, Geisinger Health System, Danville, PA, USA Abstract: The current simulation technology used for neurosurgical training leaves much to be desired. Significant efforts are thoroughly exhausted in hopes of developing simulations that translate to give learners the “real-life” feel. Though a respectable goal, this may not be necessary as the application for simulation in neurosurgical training may be most useful in early learners. The ultimate uniformly agreeable endpoint of improved outcome and patient safety drives these investments. We explore the development, availability, educational taskforces, cost burdens and the simulation advancements in neurosurgical training. The technologies can be directed at achieving early resident milestones placed by the Accreditation Council for Graduate Medical Education. We discuss various aspects of neurosurgery disciplines with specific technologic advances of simulation software. An overview of the scholarly landscape of the recent publications in the realm of medical simulation and virtual reality pertaining to neurologic surgery is provided. We analyze concurrent concept overlap between PubMed headings and provide a graphical overview of the associations between these terms. Keywords: residency education, simulation, neurosurgery training, virtual reality, haptic feedback, task analysis, ACGME 

  20. A technique to identify core journals for neurosurgery using citation scatter analysis and the Bradford distribution across neurosurgery journals.

    Science.gov (United States)

    Madhugiri, Venkatesh S; Ambekar, Sudheer; Strom, Shane F; Nanda, Anil

    2013-11-01

    The volume of scientific literature doubles approximately every 7 years. The coverage of this literature provided by online compendia is variable and incomplete. It would hence be useful to identify "core" journals in any field and validate whether the h index and impact factor truly identify the core journals in every subject. The core journals in every medical specialty would be those that provide a current and comprehensive coverage of the science in that specialty. Identifying these journals would make it possible for individual physicians to keep abreast of research and clinical progress. The top 10 neurosurgical journals (on the basis of impact factor and h index) were selected. A database of all articles cited in the reference lists of papers published in issues of these journals published in the first quarter of 2012 was generated. The journals were ranked based on the number of papers cited from each. This citation rank list was compared with the h index and impact factor rank lists. The rank list was also examined to see if the concept of core journals could be validated for neurosurgical literature using Bradford's law. A total of 22,850 papers spread across 2522 journals were cited in neurosurgical literature over 3 months. Although the top 10 journals were the same, irrespective of ranking criterion (h index, impact factor, citation ranking), the 3 rank lists were not congruent. The top 25% of cited articles obeyed the Bradford distribution; beyond this, there was a zone of increased scatter. Six core journals were identified for neurosurgery. The core journals for neurosurgery were identified to be Journal of Neurosurgery, Neurosurgery, Spine, Acta Neurochirurgica, Stroke, and Journal of Neurotrauma. A list of core journals could similarly be generated for every subject. This would facilitate a focused reading to keep abreast of current knowledge. Collated across specialties, these journals could depict the current status of medical science.

  1. Bradford's law: identification of the core journals for neurosurgery and its subspecialties.

    Science.gov (United States)

    Venable, Garrett T; Shepherd, Brandon A; Loftis, Christopher M; McClatchy, S Gray; Roberts, Mallory L; Fillinger, Meghan E; Tansey, James B; Klimo, Paul

    2016-02-01

    Bradford's law describes the scatter of citations for a given subject or field. It can be used to identify the most highly cited journals for a field or subject. The objective of this study was to use currently accepted formulations of Bradford's law to identify core journals of neurosurgery and neurosurgical subspecialties. All original research publications from 2009 to 2013 were analyzed for the top 25 North American academic neurosurgeons from each subspecialty. The top 25 were chosen from a ranked career h-index list identified from previous studies. Egghe's formulation and the verbal formulation of Bradford's law were applied to create specific citation density zones and identify the core journals for each subspecialty. The databases were then combined to identify the core journals for all of academic neurosurgery. Using Bradford's verbal law with 4 zone models, the authors were able to identify the core journals of neurosurgery and its subspecialties. The journals found in the most highly cited first zone are presented here as the core journals. For neurosurgery as a whole, the core included the following journals: Journal of Neurosurgery, Neurosurgery, Spine, Stroke, Neurology, American Journal of Neuroradiology, International Journal of Radiation Oncology Biology Physics, and New England Journal of Medicine. The core journals for each subspecialty are presented in the manuscript. Bradford's law can be used to identify the core journals of neurosurgery and its subspecialties. The core journals vary for each neurosurgical subspecialty, but Journal of Neurosurgery and Neurosurgery are among the core journals for each neurosurgical subspecialty.

  2. Experimental Economics for Teaching the Functioning of Electricity Markets

    Science.gov (United States)

    Guevara-Cedeno, J. Y.; Palma-Behnke, R.; Uribe, R.

    2012-01-01

    In the field of electricity markets, the development of training tools for engineers has been extremely useful. A novel experimental economics approach based on a computational Web platform of an electricity market is proposed here for the practical teaching of electrical engineering students. The approach is designed to diminish the gap that…

  3. Image guidance and neuromonitoring in neurosurgery.

    Science.gov (United States)

    Ng, Wai Hoe; Mukhida, Karim; Rutka, James T

    2010-04-01

    The localization of tumors and epileptogenic foci within the somatosensory or language cortex of the brain of a child poses unique neurosurgical challenges. In the past, lesions in these regions were not treated aggressively for fear of inducing neurological deficits. As a result, while function may have been preserved, the underlying disease may not have been optimally treated, and repeat neurosurgical procedures were frequently required. Today, with the advent of preoperative brain mapping, image guidance or neuronavigation, and intraoperative monitoring, peri-Rolandic and language cortex lesions can be approached directly and definitively with a high degree of confidence that neurosurgical function will be maintained. The preoperative brain maps can now be achieved with magnetic resonance imaging (MRI), functional MRI, magnetoencephalography, and diffusion tensor imaging. Image guidance systems have improved significantly and include the use of the intraoperative MRI. Somatosensory, motor, and brainstem auditory-evoked potentials are used as standard neuromonitoring techniques in many centers around the world. Added to this now is the use of continuous train-of-five monitoring of the integrity of the corticospinal tract while operating in the peri-Rolandic region. We are in an era where continued advancements can be expected in mapping additional pathways such as visual, memory, and hearing pathways. With these new advances, neurosurgeons can expect to significantly improve their surgical outcomes further.

  4. The historical origin of the term "meningioma" and the rise of nationalistic neurosurgery.

    Science.gov (United States)

    Barthélemy, Ernest Joseph; Sarkiss, Christopher A; Lee, James; Shrivastava, Raj K

    2016-11-01

    "tumeurs cancéreuses de la duremère," and the work of histopathologists, such as Hermann Lebert, who were influenced by Pasteur's germ theory and by Bernard's experimental medicine. The final development of the meningioma nomenclature corresponded to the rise of American neurosurgery as a formal academic discipline. This historical period of growth is chronicled in Cushing's text Meningiomas, and it set the scientific stage for the modern developments in meningioma research and surgery that are conducted and employed today.

  5. Animal Structures and Functions, Science (Experimental): 5314.13.

    Science.gov (United States)

    Silver, Barbara A.

    This unit of instruction was designed to introduce the student to the relationship between structure and function in the animal kingdom, with emphasis given to: (1) the evolution of physiological systems in the major animal phyla, (2) the complementarity of structure and function, and (3) the concept of homeostasis. The booklet lists the relevant…

  6. Freezing vibrational energy flow: a fitness function for interchangeable computational and experimental control.

    Science.gov (United States)

    Weidinger, D; Engel, M F; Gruebele, M

    2009-04-23

    We develop a fitness functional for freezing molecular energy flow that relies only on experimental observables. The functional allows us to implement a modular control algorithm where simulation data and experimental data can be used interchangeably. This interchangeability could be useful as a spectroscopic tool and for reactive control because the controllability of the experimental system and its model can be compared directly. The fitness functional performs as well as functionals based on complete knowledge of the wave function. We compare our simulation results with an analytical theory of control, and find good agreement between the simulated and predicted times over which the system can be controlled.

  7. Planning and Executing the Neurosurgery Boot Camp: The Bolivia Experience.

    Science.gov (United States)

    Ament, Jared D; Kim, Timothy; Gold-Markel, Judah; Germano, Isabelle M; Dempsey, Robert; Weaver, John P; DiPatri, Arthur J; Andrews, Russell J; Sanchez, Mary; Hinojosa, Juan; Moser, Richard P; Glick, Roberta

    2017-08-01

    The neurosurgical boot camp has been fully incorporated into U.S. postgraduate education. This is the first implementation of the neurosurgical boot in a developing country. To advance neurosurgical education, we developed a similar boot camp program, in collaboration with Bolivian neurosurgeons, to determine its feasibility and effectiveness in an international setting. In a collective effort, the Bolivian Society for Neurosurgery, Foundation for International Education in Neurological Surgery, Solidarity Bridge, and University of Massachusetts organized and executed the first South American neurosurgical boot camp in Bolivia in 2015. Both U.S. and Bolivian faculty led didactic lectures followed by a practicum day using mannequins and simulators. South American residents and faculty were surveyed after the course to determine levels of enthusiasm and their perceived improvement in fund of knowledge and course effectiveness. Twenty-four neurosurgery residents from 5 South American countries participated. Average survey scores ranged between 4.2 and 4.9 out of 5. Five Bolivian neurosurgeons completed the survey with average scores of 4.5-5. This event allowed for Bolivian leaders in the field to unify around education, resulting in the formation of an institute to continue similar initiatives. Total cost was estimated at $40 000 USD; however, significant faculty, industry, and donor support helped offset this amount. The first South American neurosurgical boot camp had significant value and was well received in Bolivia. This humanitarian model provides a sustainable solution to education needs and should be expanded to other regions as a means for standardizing the core competencies in neurosurgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. High functional diversity stimulates diversification in experimental microbial communities

    NARCIS (Netherlands)

    Jousset, Alexandre|info:eu-repo/dai/nl/370632656; Eisenhauer, Nico; Merker, Monika; Mouquet, Nicolas; Scheu, Stefan

    There is a growing awareness that biodiversity not only drives ecosystem services but also affects evolutionary dynamics. However, different theories predict contrasting outcomes on when do evolutionary processes occur within a context of competition. We tested whether functional diversity can

  9. eLearning resources to supplement postgraduate neurosurgery training.

    Science.gov (United States)

    Stienen, Martin N; Schaller, Karl; Cock, Hannah; Lisnic, Vitalie; Regli, Luca; Thomson, Simon

    2017-02-01

    In an increasingly complex and competitive professional environment, improving methods to educate neurosurgical residents is key to ensure high-quality patient care. Electronic (e)Learning resources promise interactive knowledge acquisition. We set out to give a comprehensive overview on available eLearning resources that aim to improve postgraduate neurosurgical training and review the available literature. A MEDLINE query was performed, using the search term "electronic AND learning AND neurosurgery". Only peer-reviewed English-language articles on the use of any means of eLearning to improve theoretical knowledge in postgraduate neurosurgical training were included. Reference lists were crosschecked for further relevant articles. Captured parameters were the year, country of origin, method of eLearning reported, and type of article, as well as its conclusion. eLearning resources were additionally searched for using Google. Of n = 301 identified articles by the MEDLINE search, n = 43 articles were analysed in detail. Applying defined criteria, n = 28 articles were excluded and n = 15 included. Most articles were generated within this decade, with groups from the USA, the UK and India having a leadership role. The majority of articles reviewed existing eLearning resources, others reported on the concept, development and use of generated eLearning resources. There was no article that scientifically assessed the effectiveness of eLearning resources (against traditional learning methods) in terms of efficacy or costs. Only one article reported on satisfaction rates with an eLearning tool. All authors of articles dealing with eLearning and the use of new media in neurosurgery uniformly agreed on its great potential and increasing future use, but most also highlighted some weaknesses and possible dangers. This review found only a few articles dealing with the modern aspects of eLearning as an adjunct to postgraduate neurosurgery training. Comprehensive

  10. Neurosurgery Education and Development program to treat hydrocephalus and to develop neurosurgery in Africa using mobile neuroendoscopic training.

    Science.gov (United States)

    Piquer, José; Qureshi, Mubashir Mahmood; Young, Paul H; Dempsey, Robert J

    2015-06-01

    OBJECT A shortage of neurosurgeons and a lack of knowledge of neuroendoscopic management of hydrocephalus limits modern care in sub-Saharan Africa. Hence, a mobile teaching project for endoscopic third ventriculostomy (ETV) procedures and a subsequent program to develop neurosurgery as a permanent specialty in Kenya and Zanzibar were created and sponsored by the Neurosurgery Education and Development (NED) Foundation and the Foundation for International Education in Neurological Surgery. The objective of this work was to evaluate the results of surgical training and medical care in both projects from 2006 to 2013. METHODS Two portable neuroendoscopy systems were purchased and a total of 38 ETV workshops were organized in 21 hospitals in 7 different countries. Additionally, 49 medical expeditions were dispatched to the Coast General Hospital in Mombasa, Kenya, and to the Mnazi Moja Hospital in Zanzibar. RESULTS From the first project, a total of 376 infants with hydrocephalus received surgery. Six-month follow-up was achieved in 22%. In those who received follow-up, ETV efficacy was 51%. The best success rates were achieved with patients 1 year of age or older with aqueductal stenosis (73%). The main causes of hydrocephalus were infection (56%) and spina bifida (23%). The mobile education program interacted with 72 local surgeons and 122 nurses who were trained in ETV procedures. The second project involved 49 volunteer neurosurgeons who performed a total of 360 nonhydrocephalus neurosurgical operations since 2009. Furthermore, an agreement with the local government was signed to create the Mnazi Mmoja NED Institute in Zanzibar. CONCLUSIONS Mobile endoscopic treatment of hydrocephalus in East Africa results in reasonable success rates and has also led to major developments in medicine, particularly in the development of neurosurgery specialty care sites.

  11. The Identification of an Educational Production Function by Experimental Means.

    Science.gov (United States)

    Garner, William T.

    Eighth grade students, randomly assigned to three criterion performance levels, studied matrix algebra in three programed lessons. Student achievement, ability, time spent, and other measures were obtained; and minimal variance criterion performance levels, analogous to production isoquants, were attained. A Cobb-Douglas (log-linear) function was…

  12. Relationships between the decoupled and coupled transfer functions: Theoretical studies and experimental validation

    Science.gov (United States)

    Wang, Zengwei; Zhu, Ping; Liu, Zhao

    2018-01-01

    A generalized method for predicting the decoupled transfer functions based on in-situ transfer functions is proposed. The method allows predicting the decoupled transfer functions using coupled transfer functions, without disassembling the system. Two ways to derive relationships between the decoupled and coupled transfer functions are presented. Issues related to immeasurability of coupled transfer functions are also discussed. The proposed method is validated by numerical and experimental case studies.

  13. The Current Use of Social Media in Neurosurgery.

    Science.gov (United States)

    Alotaibi, Naif M; Badhiwala, Jetan H; Nassiri, Farshad; Guha, Daipayan; Ibrahim, George M; Shamji, Mohammed F; Lozano, Andres M

    2016-04-01

    To measure the presence and popularity of neurosurgical departments, journals, and nonprofit organizations on 3 major social networks. A systematic 2-pronged search strategy was used in June 2015 to identify all accounts on Facebook, Twitter, and YouTube that were relevant to neurosurgery. Online search was conducted by 2 independent authors. All accounts were ranked according to their popularity data. Our search yielded 158 social media accounts (86 Facebook, 59 Twitter, and 13 YouTube) of neurosurgical private and academic practice departments. Of the 158 accounts we retrieved, 117 were for private practice centers (74%). Accounts of academic and private departments had a similar median number of "likes" and "followers" on Facebook and Twitter, respectively. Seven neurosurgical journals only had active Facebook and Twitter accounts (of 20 screened journals). When compared with studies of social media in other medical subspecialties, the use of these networks in neurosurgery followed a similar pattern in their presence and popularity. The current study shows different uses of social media platforms and numbers of users of the online neurosurgical community. Content optimization, advanced metrics of user engagement, and their subsequent effects on academic impact remain unanswered queries and require further prospective study. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Supplementary Educational Models in Canadian Neurosurgery Residency Programs.

    Science.gov (United States)

    Ryu, Won Hyung A; Chan, Sonny; Sutherland, Garnette R

    2017-03-01

    The proposed implementation of work hour restrictions has presented a significant challenge of maintaining the quality of resident education and ensuring adequate hands-on experience that is essential for novice surgeons. To maintain the level of resident surgical competency, revision of the apprentice model of surgical education to include supplementary educational methods, such as laboratory and virtual reality (VR) simulations, have become frequent topics of discussion. We aimed to better understand the role of supplementary educational methods in Canadian neurosurgery residency training. An online survey was sent to program directors of all 14 Canadian neurosurgical residency programs and active resident members of the Canadian Neurosurgical Society (N=85). We asked 16 questions focusing on topics of surgeon perception, current implementation and barriers to supplementary educational models. Of the 99 surveys sent, 8 out of 14 (57%) program directors and 37 out of 85 (44%) residents completed the survey. Of the 14 neurosurgery residency programs across Canada, 7 reported utilizing laboratory-based teaching within their educational plan, while only 3 programs reported using VR simulation as a supplementary teaching method. The biggest barriers to implementing supplementary educational methods were resident availability, lack of resources, and cost. Work-hour restrictions threaten to compromise the traditional apprentice model of surgical training. The potential value of supplementary educational methods for surgical education is evident, as reported by both program directors and residents across Canada. However, availability and utilization of laboratory and VR simulations are limited by numerous factors such as time constrains and lack of resources.

  15. W. W. Keen and the dawn of American neurosurgery.

    Science.gov (United States)

    Bingham, W F

    1986-05-01

    Before the turn of the century, W. W. Keen was the most celebrated neurosurgeon in the United States. During the Civil War he served as a surgeon in the Union Army. He collaborated with Mitchell and Morehouse in clinical studies that culminated in their publishing Gunshot Wounds and Other Injuries of Nerves. In 1887, he was the first surgeon in the Americas to remove a benign brain tumor. He perfected a technique for ventricular puncture, devised operations for spasmodic torticollis, microcephalus, and tic douloureaux, and introduced many European neurosurgical techniques to the United States. An astute clinician and excellent teacher, Keen had no research interests other than anatomical and pathological dissections. He published over 50 papers on neurosurgical topics, in addition to articles on numerous other subjects. Although recognized as a pioneer in neurosurgery, he is not usually considered a founder of neurosurgery in the United States because of his failure to develop the specialty further than his contemporaries in the remainder of the neurosurgical world. This failure related not to his abilities, but probably to the fact that he was elderly before it became technically possible to perform safe and effective intracranial procedures.

  16. [Current use of Social Media in Neurosurgery in Spain].

    Science.gov (United States)

    Mata-Gómez, Jacinto; Gilete-Tejero, Ignacio Javier; Rico-Cotelo, María; Royano-Sánchez, Manuel; Ortega-Martínez, Marta

    2018-02-24

    To analyze the current situation in Spain of the use of Social Media in Neurosurgery. We made an observational transversal study between February and March 2017, with a systematic search of the Facebook, Twitter and Youtube accounts from public and private neurosurgical units, scientific societies, peer-reviewed publications and patients groups in relation with Neurosurgical pathologies. We rank them according their popularity. According of our search only 5 public neurosurgical services have social media accounts, being their popularity inferior to the private units accounts. In relation with the scientific societies and neurosurgical publications their presence in social media is marginal, even more in comparison to the accounts of other medical specialities. The popularity of associations of patients and supporting groups is high, especially among patients, finding there more information about their disease. The use in Spain of Social Media about Neurosurgery is low in comparison to other medical specialities. There is a huge field to improve the popularity of the accounts, making in them promotion of health and extend the diffusion of the scientific society and the peer-reviewed publication Neurocirugía. Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Rhabdomyolysis after neurosurgery: a review and a framework for prevention.

    Science.gov (United States)

    De Tommasi, Claudio; Cusimano, Michael D

    2013-04-01

    Rhabdomyolysis (RM) is a potentially fatal or disabling clinical syndrome resulting in muscle necrosis and leakage of muscle constituents into the blood. Lactic acidosis and more serious complications such as acute renal failure may occur in up to half of recognized cases, so accurate diagnosis is required. We present three cases in which RM occurred in patients undergoing neurosurgical procedures performed in the lateral position. A review of the literature is provided together with a framework for the prevention of this surgical complication. Three patients underwent neurosurgical procedures in the lateral position for left facial/glossopharyngeal neuralgia, for jugular foramen tumor, and for a petroclival meningioma, respectively. All patients were obese and all three showed massive postoperative elevation in creatine kinase (CK) levels characteristic of RM. Myoglobinuria was identified in two patients and all three showed hyperintensity of the hip gird muscles in the short tau inversion recovery sequence magnetic resonance imaging. All recovered spontaneously and none went on to develop renal failure. A literature review showed that RM has been rarely reported after neurosurgery. However, the duration of procedures of the cases of reported RM indicates that the prevalence of the condition is likely highly under-recognized in neurosurgery. This is particularly important given the rising obesity rates seen in many countries. Obese patients undergoing long neurosurgical procedures, particularly in the lateral position, should be suspected of RM and should be closely monitored for CK levels, myoglobinuria, and acidosis. We outline a framework of strategies for the prevention of the condition.

  18. Advances in the indirect, descriptive, and experimental approaches to the functional analysis of problem behavior.

    Science.gov (United States)

    Wightman, Jade; Julio, Flávia; Virués-Ortega, Javier

    2014-05-01

    Experimental functional analysis is an assessment methodology to identify the environmental factors that maintain problem behavior in individuals with developmental disabilities and in other populations. Functional analysis provides the basis for the development of reinforcement-based approaches to treatment. This article reviews the procedures, validity, and clinical implementation of the methodological variations of functional analysis and function-based interventions. We present six variations of functional analysis methodology in addition to the typical functional analysis: brief functional analysis, single-function tests, latency-based functional analysis, functional analysis of precursors, and trial-based functional analysis. We also present the three general categories of function-based interventions: extinction, antecedent manipulation, and differential reinforcement. Functional analysis methodology is a valid and efficient approach to the assessment of problem behavior and the selection of treatment strategies.

  19. Lymphatic vessel density and function in experimental bladder cancer

    Directory of Open Access Journals (Sweden)

    Maier Julie

    2007-11-01

    Full Text Available Abstract Background The lymphatics form a second circulatory system that drains the extracellular fluid and proteins from the tumor microenvironment, and provides an exclusive environment in which immune cells interact and respond to foreign antigen. Both cancer and inflammation are known to induce lymphangiogenesis. However, little is known about bladder lymphatic vessels and their involvement in cancer formation and progression. Methods A double transgenic mouse model was generated by crossing a bladder cancer-induced transgenic, in which SV40 large T antigen was under the control of uroplakin II promoter, with another transgenic mouse harboring a lacZ reporter gene under the control of an NF-κB-responsive promoter (κB-lacZ exhibiting constitutive activity of β-galactosidase in lymphatic endothelial cells. In this new mouse model (SV40-lacZ, we examined the lymphatic vessel density (LVD and function (LVF during bladder cancer progression. LVD was performed in bladder whole mounts and cross-sections by fluorescent immunohistochemistry (IHC using LYVE-1 antibody. LVF was assessed by real-time in vivo imaging techniques using a contrast agent (biotin-BSA-Gd-DTPA-Cy5.5; Gd-Cy5.5 suitable for both magnetic resonance imaging (MRI and near infrared fluorescence (NIRF. In addition, IHC of Cy5.5 was used for time-course analysis of co-localization of Gd-Cy5.5 with LYVE-1-positive lymphatics and CD31-positive blood vessels. Results SV40-lacZ mice develop bladder cancer and permitted visualization of lymphatics. A significant increase in LVD was found concomitantly with bladder cancer progression. Double labeling of the bladder cross-sections with LYVE-1 and Ki-67 antibodies indicated cancer-induced lymphangiogenesis. MRI detected mouse bladder cancer, as early as 4 months, and permitted to follow tumor sizes during cancer progression. Using Gd-Cy5.5 as a contrast agent for MRI-guided lymphangiography, we determined a possible reduction of lymphatic

  20. The prognostic value of histopathology on lingual nerve neurosensory recovery after micro-neurosurgery

    DEFF Research Database (Denmark)

    Hørberg, Mette; Reibel, Jesper; Kragelund, Camilla

    2016-01-01

    OBJECTIVE: Micro-neurosurgical repair is considered in permanent nerve damage but the outcome is unpredictable. We examined if histopathologic parameters of traumatic neuromas have a prognostic value for recovery in relation to lingual nerve micro-neurosurgery. MATERIALS AND METHODS: Retrospective...... case study on neurosensory recovery after micro-neurosurgery. Outcome variables were as follows: pain perception, two-point discrimination, and sum score of perception, before and 12 months after micro-neurosurgery. Predictive histopathology variables included size, nerve tissue, and inflammation...

  1. Simulation and augmented reality in endovascular neurosurgery: lessons from aviation.

    Science.gov (United States)

    Mitha, Alim P; Almekhlafi, Mohammed A; Janjua, Major Jameel J; Albuquerque, Felipe C; McDougall, Cameron G

    2013-01-01

    Endovascular neurosurgery is a discipline strongly dependent on imaging. Therefore, technology that improves how much useful information we can garner from a single image has the potential to dramatically assist decision making during endovascular procedures. Furthermore, education in an image-enhanced environment, especially with the incorporation of simulation, can improve the safety of the procedures and give interventionalists and trainees the opportunity to study or perform simulated procedures before the intervention, much like what is practiced in the field of aviation. Here, we examine the use of simulators in the training of fighter pilots and discuss how similar benefits can compensate for current deficiencies in endovascular training. We describe the types of simulation used for endovascular procedures, including virtual reality, and discuss the relevant data on its utility in training. Finally, the benefit of augmented reality during endovascular procedures is discussed, along with future computerized image enhancement techniques.

  2. Balloons in endovascular neurosurgery: history and current applications.

    Science.gov (United States)

    Alaraj, Ali; Wallace, Adam; Dashti, Reza; Patel, Prasad; Aletich, Victor

    2014-02-01

    The use of balloons in the field of neurosurgery is currently an essential part of our clinical practice. The field has evolved over the last 40 years since Serbinenko used balloons to test the feasibility of occluding cervical vessels for intracranial pathologies. Since that time, indications have expanded to include sacrificing cervical and intracranial vessels with detachable balloons, supporting the coil mass in wide-necked aneurysms (balloon remodeling technique), and performing intracranial and cervical angioplasty for atherosclerotic disease, as well as an adjunct to treat arteriovenous malformations. With the rapid expansion of endovascular technologies, it appears that the indications and uses for balloons will continue to expand. In this article, we review the history of balloons, the initial applications, the types of balloons available, and the current applications available for endovascular neurosurgeons.

  3. Experimental drying shrinkage of hardened cement pastes as a function of relative humidity

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Baroghel, V.B.

    1996-01-01

    The results of an experimental study concerning drying shrinkage measured as a function of relative humidity on thin specimens of mature hardened cement pastes are presented. The results obtained at two laboratories are compared.......The results of an experimental study concerning drying shrinkage measured as a function of relative humidity on thin specimens of mature hardened cement pastes are presented. The results obtained at two laboratories are compared....

  4. Intraoperative Eptifibatide Administration During Urgent Arterial Bypass in Neurosurgery.

    Science.gov (United States)

    Stambolija, Vasilije; Mrak, Goran; Lozic, Marin; Ljevak, Josip; Miklic Bublic, Martina; Scap, Miroslav

    2017-07-01

    In some cases when risk of occlusion of a blood vessel is greater than risk of bleeding when patients undergo urgent or unplanned bypass during neurosurgery, the use of eptifibatide may be an option. We describe 2 patients who underwent arterial bypass in whom eptifibatide was used successfully intraoperatively during neurosurgery for prevention of bypass occlusion. The first patient presented with a right middle cerebral artery (MCA) aneurysm with subocclusive stenosis of the M1 branch. After right-sided osteoplastic frontotemporal craniotomy, the MCA bifurcation was exposed with a bifurcational 6-mm aneurysm with a wide neck. Prebifurcation stenosis was found, with yellow calcification of the vessel wall, and postbifurcation calcification was found on the upper M2 branch. Superficial temporal artery-MCA bypass and occlusion of the MCA aneurysm was done. Before the bypass, continuous intravenous infusion of eptifibatide 1 μg/kg/minute was administered. The patient recovered normally without hemorrhage or neurologic deficit. The second patient presented with a left-sided lateral sphenoid wing meningioma. Left-sided frontotemporal craniotomy was performed, and the tumor was completely removed from the arachnoid layer. The temporal M3 branch was invaded by the meningioma. As there was no flow through the invaded segment of the aforementioned artery, termino-terminal M3 arterial anastomosis was done. Continuous intravenous infusion of eptifibatide 1 μg/kg/minute was administered. Indocyanine green angiography showed normal flow through the anastomosis, and the patient recovered normally. Future studies are needed to test the safety and potential efficacy of eptifibatide in intraoperative settings. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Diversity-dependent temporal divergence of ecosystem functioning in experimental ecosystems.

    Science.gov (United States)

    Guerrero-Ramírez, Nathaly R; Craven, Dylan; Reich, Peter B; Ewel, John J; Isbell, Forest; Koricheva, Julia; Parrotta, John A; Auge, Harald; Erickson, Heather E; Forrester, David I; Hector, Andy; Joshi, Jasmin; Montagnini, Florencia; Palmborg, Cecilia; Piotto, Daniel; Potvin, Catherine; Roscher, Christiane; van Ruijven, Jasper; Tilman, David; Wilsey, Brian; Eisenhauer, Nico

    2017-11-01

    The effects of biodiversity on ecosystem functioning generally increase over time, but the underlying processes remain unclear. Using 26 long-term grassland and forest experimental ecosystems, we demonstrate that biodiversity-ecosystem functioning relationships strengthen mainly by greater increases in functioning in high-diversity communities in grasslands and forests. In grasslands, biodiversity effects also strengthen due to decreases in functioning in low-diversity communities. Contrasting trends across grasslands are associated with differences in soil characteristics.

  6. Academic Productivity of US Neurosurgery Residents as Measured by H-Index: Program Ranking with Correlation to Faculty Productivity.

    Science.gov (United States)

    Sarkiss, Christopher A; Riley, Kyle J; Hernandez, Christopher M; Oermann, Eric K; Ladner, Travis R; Bederson, Joshua B; Shrivastava, Raj K

    2017-06-01

    Engagement in research and academic productivity are crucial components in the training of a neurosurgeon. This process typically begins in residency training. In this study, we analyzed individual resident productivity as it correlated to publications across all Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgery training programs in an attempt to identify how programs have developed and fostered a research culture and environment. We obtained a list of current neurosurgery residents in ACGME-accredited programs from the American Association of Neurological Surgeons database. An expanded PubMed and Scopus search was conducted for each resident through the present time. We tabulated all articles attributed to each resident. We then categorized the publications based on each neurosurgical subspecialty while in residency. A spreadsheet-based statistical analysis was performed. This formulated the average number of resident articles, h-indices, and most common subspecialty categories by training program. We analyzed 1352 current neurosurgery residents in 105 programs. There were a total of 10 645 publications, of which 3985 were resident first-author publications during the period of study. The most common subspecialties among all resident publications were vascular (24.9%), spine (16.9%), oncology (16.1%), pediatric (5.6%), functional (4.9%), and trauma (3.8%). The average resident published 2.9 first-author papers with average of 38.0 first-author publications by total residents at each program (range 0-241). The average h-index per resident is 2.47 ± 3.25. When comparing previously published faculty h-index program rankings against our resident h-index rankings, there is a strong correlation between the 2 datasets with a clear delineation between Top-20 productivity and that of other programs (average h-index 4.2 vs 1.7, respectively, P productivity on both the resident and faculty level (average h-index 1.6, 1.9, 3.9 for 1, 2, and

  7. Cognitive eloquence in neurosurgery: Insight from graph theoretical analysis of complex brain networks.

    Science.gov (United States)

    Lang, Stefan

    2017-01-01

    The structure and function of the brain can be described by complex network models, and the topological properties of these models can be quantified by graph theoretical analysis. This has given insight into brain regions, known as hubs, which are critical for integrative functioning and information transfer, both fundamental aspects of cognition. In this manuscript a hypothesis is put forward for the concept of cognitive eloquence in neurosurgery; that is regions (cortical, subcortical and white matter) of the brain which may not necessarily have readily identifiable neurological function, but if injured may result in disproportionate cognitive morbidity. To this end, the effects of neurosurgical resection on cognition is reviewed and an overview of the role of complex network analysis in the understanding of brain structure and function is provided. The literature describing network, behavioral, and cognitive effects resulting from lesions to, and disconnections of, centralized hub regions will be emphasized as evidence for the espousal of the concept of cognitive eloquence. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Experimental evidence for strong stabilizing forces at high functional diversity of aquatic microbial communities.

    Science.gov (United States)

    Carrara, Francesco; Giometto, Andrea; Seymour, Mathew; Rinaldo, Andrea; Altermatt, Florian

    2015-05-01

    Unveiling the mechanisms that promote coexistence in biological communities is a fundamental problem in ecology. Stable coexistence of many species is commonly observed in natural communities. Most of these natural communities, however, are composed of species from multiple trophic and functional groups, while theory and experiments on coexistence have been focusing on functionally similar species. Here, we investigated how functional diversity affects the stability of species coexistence and productivity in multispecies communities by characterizing experimentally all pairwise species interactions in a pool of 11 species of eukaryotes (10 protists and one rotifer) belonging to three different functional groups. Species within the same functional group showed stronger competitive interactions compared to among-functional group interactions. This often led to competitive exclusion between species that had higher functional relatedness, but only at low levels of species richness. Communities with higher functional diversity resulted in increased species coexistence and community biomass production. Our experimental findings and the results of a stochastic model tailored to the experimental interaction matrix suggest the emergence of strong stabilizing forces when species from different functional groups interact in a homogeneous environment. By combining theoretical analysis with experiments we could also disentangle the relationship between species richness and functional diversity, showing that functional diversity per se is a crucial driver of productivity and stability in multispecies community.

  9. Harvey Cushing and "birth hemorrhage": early pediatric neurosurgery at The Johns Hopkins Hospital.

    Science.gov (United States)

    Mehta, Vivek A; Wijesekera, Olindi; Pendleton, Courtney; Quiñones-Hinojosa, Alfredo; Jallo, George I; Ahn, Edward S

    2011-12-01

    Of Harvey Cushing's many contributions to neurosurgery, one of the least documented is his early surgical intervention in children and his pioneering efforts to establish pediatric neurosurgery as a subspecialty. Between 1896 and 1912 Cushing conducted nearly 200 operations in children at The Johns Hopkins Hospital. A review of his records suggests that the advances he made in neurosurgery were significantly influenced by his experience with children. In this historical article, the authors describe Cushing's treatment of 6 children, in all of whom Cushing established a diagnosis of "birth hemorrhage." By reviewing Cushing's operative indications, techniques, and outcomes, the authors aim to understand the philosophy of his pediatric neurosurgical management and how this informed his development of neurosurgery as a new specialty.

  10. Candida infection of the central nervous system following neurosurgery: a 12-year review.

    LENUS (Irish Health Repository)

    O'Brien, Deirdre

    2011-06-01

    Candida infection of the central nervous system (CNS) following neurosurgery is relatively unusual but is associated with significant morbidity and mortality. We present our experience with this infection in adults and discuss clinical characteristics, treatment options, and outcome.

  11. Zig-zag bicoronal scalp incision for cranio-facial cases in paediatric neurosurgery.

    Science.gov (United States)

    Leach, Paul; Rutherford, S; Likhith, A; Leggate, J

    2004-07-01

    We present the use of a zig-zag bicoronal scalp incision for cranial-facial cases in paediatric neurosurgery. The authors believe that this technique leads to improved cosmesis, especially when the hair is wet.

  12. Examining the Function of Problem Behavior in Fragile X Syndrome: Preliminary Experimental Analysis

    Science.gov (United States)

    Langthorne, Paul; McGill, Peter; O'Reilly, Mark F.; Lang, Russell; Machalicek, Wendy; Chan, Jeffrey Michael; Rispoli, Mandy

    2011-01-01

    Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis…

  13. Utilizing virtual and augmented reality for educational and clinical enhancements in neurosurgery.

    Science.gov (United States)

    Pelargos, Panayiotis E; Nagasawa, Daniel T; Lagman, Carlito; Tenn, Stephen; Demos, Joanna V; Lee, Seung J; Bui, Timothy T; Barnette, Natalie E; Bhatt, Nikhilesh S; Ung, Nolan; Bari, Ausaf; Martin, Neil A; Yang, Isaac

    2017-01-01

    Neurosurgery has undergone a technological revolution over the past several decades, from trephination to image-guided navigation. Advancements in virtual reality (VR) and augmented reality (AR) represent some of the newest modalities being integrated into neurosurgical practice and resident education. In this review, we present a historical perspective of the development of VR and AR technologies, analyze its current uses, and discuss its emerging applications in the field of neurosurgery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Computational and experimental studies of reassociating RNA/DNA hybrids containing split functionalities.

    Science.gov (United States)

    Afonin, Kirill A; Bindewald, Eckart; Kireeva, Maria; Shapiro, Bruce A

    2015-01-01

    Recently, we developed a novel technique based on RNA/DNA hybrid reassociation that allows conditional activation of different split functionalities inside diseased cells and in vivo. We further expanded this idea to permit simultaneous activation of multiple different functions in a fully controllable fashion. In this chapter, we discuss some novel computational approaches and experimental techniques aimed at the characterization, design, and production of reassociating RNA/DNA hybrids containing split functionalities. We also briefly describe several experimental techniques that can be used to test these hybrids in vitro and in vivo. 2015 Published by Elsevier Inc.

  15. Postoperative intracranial neurosurgery infection rates in North America versus Europe: a systematic analysis.

    Science.gov (United States)

    McClelland, Shearwood

    2008-10-01

    Postoperative wound infection (PWI) after intracranial neurosurgery remains a significant worldwide problem, resulting in substantial morbidity/mortality if not combatted quickly and energetically. Although the danger of PWI is universally recognized, the reported incidence of PWI after intracranial neurosurgery remains variable, ranging from 1% to 8% in published series. The impact of geography on this reported variability has not been previously investigated. To address this issue, published comprehensive intracranial neurosurgery series were reviewed, segregating findings geographically between North American and European series. A comprehensive literature search was conducted using the Entrez gateway of the PubMed database. Studies conducted in North America and Europe reporting the incidence of PWI after intracranial neurosurgery were subjected to a thorough review. Data from studies meeting inclusion criteria (minimum of 500 cases with no systematic exclusion of procedures) were categorized by origin (North American/European) and design (retrospective/prospective). Recorded incidences were then compared using chi(2) analysis, and estimates of the relative risk of PWI were calculated. Seven studies (4 North American, 3 European) met all of the inclusion criteria, with a 2.6-fold greater PWI incidence reported in the European studies (P PWI for Europeans versus North Americans per operative case was 2.60. PWI after intracranial neurosurgery was nearly 3 times more likely in European versus North American studies. These findings should be considered by clinicians when estimating the risks of intracranial neurosurgery, and highlight the need for future prospective studies to provide evidence-based explanations for these differences.

  16. MATHEMATICAL MODELLING OF PREFERED SOLUTIONS CHOICE FUNCTION FOR TUBULAR GAS HEATERS BY EXPERIMENTAL INFORMATIONS

    Directory of Open Access Journals (Sweden)

    BARSUK R. V.

    2016-08-01

    Full Text Available Annotation. Problems formulation. The article deals with choice functions building of preferred solutions by experimental information for tubular gas heater working on fuel granules - pellets.Further choice functions using for making technical solutions by tubular gas heaters construction and designing. Recently research analysis. There are works about choice functions construction by separate presents are examined. But full chose functions building by separate presents are not examined. Aims and tasks. There are setting aim to develop full choice functions mathematical model on separate presents by authors. The expert are connect to primary experimental data’s evaluation that estimates separate results by output functions (criteria. Its evaluations issue in experimental points paired comparison’s table form. Thus, there are necessary construct binary choice relations presents on experimental “points” set by expert that then using for full choice function’s constructing. Conclusions. There are choice function’s construction’s sequence are sets. There are posed point comparison results that characterized tubular gas heater’s condition with expert’s evaluation using. Also posed output functions comparisons by which can be characterized improving tubular gas heater’s performance or vice versa.

  17. Experimentation on accuracy of non functional requirement prioritization approaches for different complexity projects

    Directory of Open Access Journals (Sweden)

    Raj Kumar Chopra

    2016-09-01

    Full Text Available Non functional requirements must be selected for implementation together with functional requirements to enhance the success of software projects. Three approaches exist for performing the prioritization of non functional requirements using the suitable prioritization technique. This paper performs experimentation on three different complexity versions of the industrial software project using cost-value prioritization technique employing three approaches. Experimentation is conducted to analyze the accuracy of individual approaches and the variation of accuracy with the complexity of the software project. The results indicate that selecting non functional requirements separately, but in accordance with functionality has higher accuracy amongst the other two approaches. Further, likewise other approaches, it witnesses the decrease in accuracy with increase in software complexity but the decrease is minimal.

  18. Augmented-reality integrated robotics in neurosurgery: are we there yet?

    Science.gov (United States)

    Madhavan, Karthik; Kolcun, John Paul G; Chieng, Lee Onn; Wang, Michael Y

    2017-05-01

    Surgical robots have captured the interest-if not the widespread acceptance-of spinal neurosurgeons. But successful innovation, scientific or commercial, requires the majority to adopt a new practice. "Faster, better, cheaper" products should in theory conquer the market, but often fail. The psychology of change is complex, and the "follow the leader" mentality, common in the field today, lends little trust to the process of disseminating new technology. Beyond product quality, timing has proven to be a key factor in the inception, design, and execution of new technologies. Although the first robotic surgery was performed in 1985, scant progress was seen until the era of minimally invasive surgery. This movement increased neurosurgeons' dependence on navigation and fluoroscopy, intensifying the drive for enhanced precision. Outside the field of medicine, various technology companies have made great progress in popularizing co-robots ("cobots"), augmented reality, and processor chips. This has helped to ease practicing surgeons into familiarity with and acceptance of these technologies. The adoption among neurosurgeons in training is a "follow the leader" phenomenon, wherein new surgeons tend to adopt the technology used during residency. In neurosurgery today, robots are limited to computers functioning between the surgeon and patient. Their functions are confined to establishing a trajectory for navigation, with task execution solely in the surgeon's hands. In this review, the authors discuss significant untapped technologies waiting to be used for more meaningful applications. They explore the history and current manifestations of various modern technologies, and project what innovations may lie ahead.

  19. Historical perspective on the Department of Neurosurgery at the Henry Ford Hospital.

    Science.gov (United States)

    Kole, M K; O'Leary, S T; Malik, G M; Rosenblum, M L

    2001-02-01

    The Henry Ford Hospital (HFH) was founded in 1915 as a philanthropic gift from Henry Ford, the automobile magnate and inventor of the Model T. The hospital and its organizational structure represented a nonsectarian facility that would provide care for all members of society. The system was patterned after the newest and most modern medical centers at the time in Europe, Canada, and the United States, including the German Krankenhauser, the Johns Hopkins Hospital, the Mayo Clinic, and the Peter Bent Brigham Hospital in Boston. The HFH grew into the Henry Ford Health System in the 1970s to 1990s, with the acquisition of other hospitals, the development of a multiple-region-based clinic system through southeastern Michigan, and the development of comprehensive, vertically integrated health care systems. The Division of Neurosurgery at HFH was established by Albert Crawford in 1926. The tradition of training residents in neurosurgery began in 1946, and the residency training program was accredited by the American Board of Neurosurgery in 1954. In 1970, the Division of Neurosurgery of the Department of Surgery was combined with the Division of Neurology to create the joint Department of Neurology and Neurosurgery. A separate Department of Neurosurgery was established in 1981. Four individuals have served as chairmen of the Department of Neurosurgery at HFH, i.e., Albert Crawford (1926-1952), Robert Knighton (1952-1978), James Ausman (1978-1991), and Mark Rosenblum (1992 to the present). During the 1980s and 1990s, HFH evolved into the vertically integrated, regionally distributed Henry Ford Health System. Under the current direction of Dr. Rosenblum, the Department of Neurosurgery at HFH has grown to include 11 full-time neurosurgeons, 2 neuro-oncologists, and 3 investigators with Ph.D. degrees and has recently expanded into three additional hospitals in southeastern Michigan, paralleling the growth of the system. The faculty annually treats more than 2,000 cases in

  20. Autonomic nervous system function in patients with functional abdominal pain. An experimental study

    DEFF Research Database (Denmark)

    Jørgensen, L S; Christiansen, P; Raundahl, U

    1993-01-01

    as the mean square successive differences of the R-R intervals (MSSD), indicating a higher basal parasympathetic neural activity (mean MSSD +/- SEM = 64 +/- 6 msec in the functional group, 46 +/- 6 msec in the healthy group, and 49 +/- 6 msec in the organic group; P = 0.03). A reduced sympathetic neural......Functional abdominal pain--that is, pain without demonstrable organic abnormalities--has often been associated with psychologic stress. The aim of the present study was to investigate whether sympathetic nervous system response to laboratory stress and basal parasympathetic neural activity were...... disturbed in 22 patients with functional abdominal pain (functional group) as compared with 14 healthy controls (healthy group) and 26 patients with organic abdominal pain (organic group) due to duodenal ulcer (DU), gallstones, or urinary tract calculi. Plasma adrenocorticotrophic hormone (ACTH) and serum...

  1. Surgical expertise in neurosurgery: integrating theory into practice.

    Science.gov (United States)

    Gélinas-Phaneuf, Nicholas; Del Maestro, Rolando F

    2013-10-01

    : The development of technical skills is a major goal of any neurosurgical training program. Residency programs in North America are focused on achieving an adequate level of training to produce technically competent surgeons. The training requirements and educational environments needed to produce expert surgeons are incompletely understood. This review explores the theoretical implications of training technical skills to expertise rather than competency in a complex field such as neurosurgery. First, the terms technical expertise and technical competency are defined. Definitions of these qualities are lacking in all surgical specialties. Second, the assessment of technical skills of neurosurgeons are investigated using an expert performance approach. This approach entails the design of tasks that can capture the level of expertise in a reproducible manner. One method to accomplish this involves the use of novel simulators with validated performance metrics. Third, the training of technical skills using simulation is studied in the optic of developing training curricula that would target the development of expertise rather than simple competency. Such curricula should include objective assessments of technical skills, appropriate feedback, and a distributed schedule of deliberate practice. Implementing a focus on the development of expertise rather than simple competency in surgical performance will lead to innovative developments in the field of neurosurgical education. Novel technologies, such as simulation, will play important roles in the training of future expert surgeons, and focused technical skills curricula with a sound theoretical basis should guide the development of all such programs.

  2. Turkish Contribution to Journal of Neurosurgery and Acta Neurochirurgica.

    Science.gov (United States)

    Altinors, Nur; Comert, Serhat; Sonmez, Erkin; Altinel, Faruk

    2017-01-01

    To evaluate the contribution of Turkish scientists to four journals published by Journal of Neurosurgery (JNS) Publishing Group and to Acta Neurochirurgica (AN) and to its Supplement (ANS). We reviewed every issue of those journals to December 2015 for the total number of articles, articles produced from studies performed entirely in Turkey, and for publications overseas co-authored by the Turkish scientists using the websites of these journals. Citations were searched using "Web of Science" and "Google Scholar" databases. The total number of articles published was 19822 for JNS, 3227 for JNS Spine, 2526 for JNS Pediatrics and 2997 for Neurosurgical Focus. Turkish contribution was 556 articles. 337 (60.61%) articles were the products of studies performed entirely in Turkey, while 219 (39.38%) articles came from overseas, co-authored by Turkish scientists. Overall contribution was 1.94%. A total of 6469 articles were published in AN. 340 papers were the products of studies performed entirely in Turkey. Turkish scientists working overseas co-authored 37 articles. Total contribution was 377 articles (5.82%). 4134 papers had been published in ANS. Contribution was 69 articles (1.66%). Turkish contribution to these journals has started late. The gap has been compensated with publications in the last two decades. Manuscripts of higher scientific level with greater number of citations are needed to increase Turkish contribution to such journals.

  3. Three-dimensional printing: technologies, applications, and limitations in neurosurgery.

    Science.gov (United States)

    Pucci, Josephine U; Christophe, Brandon R; Sisti, Jonathan A; Connolly, Edward S

    2017-09-01

    Three-dimensional (3D) printers are a developing technology penetrating a variety of markets, including the medical sector. Since its introduction to the medical field in the late 1980s, 3D printers have constructed a range of devices, such as dentures, hearing aids, and prosthetics. With the ultimate goals of decreasing healthcare costs and improving patient care and outcomes, neurosurgeons are utilizing this dynamic technology, as well. Digital Imaging and Communication in Medicine (DICOM) can be translated into Stereolithography (STL) files, which are then read and methodically built by 3D Printers. Vessels, tumors, and skulls are just a few of the anatomical structures created in a variety of materials, which enable surgeons to conduct research, educate surgeons in training, and improve pre-operative planning without risk to patients. Due to the infancy of the field and a wide range of technologies with varying advantages and disadvantages, there is currently no standard 3D printing process for patient care and medical research. In an effort to enable clinicians to optimize the use of additive manufacturing (AM) technologies, we outline the most suitable 3D printing models and computer-aided design (CAD) software for 3D printing in neurosurgery, their applications, and the limitations that need to be overcome if 3D printers are to become common practice in the neurosurgical field. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Numerical and experimental study of the characteristic functions of polygon scanners

    Science.gov (United States)

    Duma, Virgil-Florin; Nicolov, Mirela

    2009-06-01

    A MathCad analysis of the mathematical functions and parameters of polygonal scanning heads is achieved. The results of a previous, rigorous analytical study we have performed are used. A scanning system for dimensional measurements has been considered. However, most of the results obtained are valid for any application of polygon mirror (PM) scanners. The characteristic functions and parameters of the PM scanner in the dimensional measurements setup, i.e. i.e. scanning function and velocity, characteristic angles and duty cycle are discussed. The analysis is performed with regard to the constructive parameters of the polygonal scanning system. An experimental stall is designed and constructed, and some of the experimental results concerning the scanning function, relevant for the analysis performed are presented.

  5. Autonomic nervous system function in patients with functional abdominal pain. An experimental study

    DEFF Research Database (Denmark)

    Jørgensen, L S; Christiansen, P; Raundahl, U

    1993-01-01

    Functional abdominal pain--that is, pain without demonstrable organic abnormalities--has often been associated with psychologic stress. The aim of the present study was to investigate whether sympathetic nervous system response to laboratory stress and basal parasympathetic neural activity were...

  6. Structure and function of zooplankton colonization in twelve new experimental ponds

    OpenAIRE

    Jenkins, David Glenn

    1990-01-01

    This study examined the structural and functional development of zooplankton communities in 12 new experimental ponds for one year and tested four predictions derived from the Random Placement Hypothesis (Coleman 1981). Physico-chemistry, zooplankton colonization dynamics, zooplankton community structure and function were analyzed every two weeks from 5 February 1988 to 10 February 1989. Ponds varied in physico-chemistry at points in time but followed similar patter...

  7. Cortically evoked responses of human pallidal neurons recorded during stereotactic neurosurgery.

    Science.gov (United States)

    Nishibayashi, Hiroki; Ogura, Mitsuhiro; Kakishita, Koji; Tanaka, Satoshi; Tachibana, Yoshihisa; Nambu, Atsushi; Kita, Hitoshi; Itakura, Toru

    2011-02-15

    Responses of neurons in the globus pallidus (GP) to cortical stimulation were recorded for the first time in humans. We performed microelectrode recordings of GP neurons in 10 Parkinson's disease (PD) patients and 1 cervical dystonia (CD) patient during surgeries to implant bilateral deep brain stimulation electrodes in the GP. To identify the motor territories in the external (GPe) and internal (GPi) segments of the GP, unitary responses evoked by stimulation of the primary motor cortex were observed by constructing peristimulus time histograms. Neurons in the motor territories of the GPe and GPi responded to cortical stimulation. Response patterns observed in the PD patients were combinations of an early excitation, an inhibition, and a late excitation. In addition, in the CD patient, a long-lasting inhibition was prominent, suggesting increased activity along the cortico-striato-GPe/GPi pathways. The firing rates of GPe and GPi neurons in the CD patient were lower than those in the PD patients. Many GPe and GPi neurons of the PD and CD patients showed burst or oscillatory burst activity. Effective cathodal contacts tended to be located close to the responding neurons. Such unitary responses induced by cortical stimulation may be of use to target motor territories of the GP for stereotactic functional neurosurgery. Future findings utilizing this method may give us new insights into understanding the pathophysiology of movement disorders. Copyright © 2011 Movement Disorder Society.

  8. Development of Experimental Protocol for Visual Cognitive Function Evaluation in Children with Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Pereverzeva D.S.,

    2016-10-01

    Full Text Available The article aims to present experimental protocol for investigation of visual cognitive function in children and adolescents with autism spectrum disorders. Description of experimental design is introduced by theoretical review of visual attention, perception and visual-motor control development in children with idiopathic autism and those with Fragile X mental retardation syndrome. Research method presented in the article is based on recent studies of visual cognitive function development under normal and pathological condition. The protocol includes three experimental paradigms: “antisaccade test”, “big/ figures”, and “photos test” performed by making use of eye tracking recording. This work was supported by grant RFBR 14-06-31284

  9. Experimental parameterization of an energy function for the simulation of unfolded proteins

    DEFF Research Database (Denmark)

    Norgaard, A.B.; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, K.

    2008-01-01

    and employs a fast and efficient gradient descent method to find the set of parameters of the energy function that best explain the experimental data. We first validate the method by using synthetic reference data, and subsequently apply the algorithms to data from nuclear magnetic resonance spin...

  10. An experimental study on nonlinear function computation for neural/fuzzy hardware design.

    Science.gov (United States)

    Basterretxea, Koldo; Tarela, José Manuel; del Campo, Inés; Bosque, Guillermo

    2007-01-01

    An experimental study on the influence of the computation of basic nodal nonlinear functions on the performance of (NFSs) is described in this paper. Systems' architecture size, their approximation capability, and the smoothness of provided mappings are used as performance indexes for this comparative paper. Two widely used kernel functions, the sigmoid-logistic function and the Gaussian function, are analyzed by their computation through an accuracy-controllable approximation algorithm designed for hardware implementation. Two artificial neural network (ANN) paradigms are selected for the analysis: backpropagation neural networks (BPNNs) with one hidden layer and radial basis function (RBF) networks. Extensive simulation of simple benchmark approximation problems is used in order to achieve generalizable conclusions. For the performance analysis of fuzzy systems, a functional equivalence theorem is used to extend obtained results to fuzzy inference systems (FISs). Finally, the adaptive neurofuzzy inference system (ANFIS) paradigm is used to observe the behavior of neurofuzzy systems with learning capabilities.

  11. History of the Neurosurgery Department of Pontificia Universidad Catolica, Santiago, Chile.

    Science.gov (United States)

    Sfeir, Felipe; Villanueva, Pablo; Tagle, Patricio

    2017-01-01

    Pontificia Universidad Católica de Chile's medical school was founded in 1929. An interest in neurosurgical development arose in the minds of the Dean, Dr. Cristobal Espíldora, and the Chief of Surgery, Dr. Rodolfo Rencoret, in 1946. They encouraged and supported Dr. J. Ricardo Olivares to specialize in Neurosurgery with Professor H. Olivecrona in Stockholm, Sweden. The first neurosurgical procedure in the Hospital Clínico de la Universidad Católica was performed in 1950. Since then, intensive efforts have been made to develop neurosurgery and its science. As a result, it is now a center capable of achieving high-quality standards in vascular, oncologic, and endoscopic neurosurgery; stereotactic and radiosurgery; complex spine surgery; pediatric neurosurgery; and epilepsy surgery. This article tells the story of a university hospital neurosurgery service in a country at the southern end of the world and how it became one of the most important neurosurgical centers in Chile and South America. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Crisis Management Simulation: Establishing a Dual Neurosurgery and Anesthesia Training Experience.

    Science.gov (United States)

    Ciporen, Jeremy; Gillham, Haley; Noles, Michele; Dillman, Dawn; Baskerville, Mark; Haley, Caleb; Spight, Donn; Turner, Ryan C; Lucke-Wold, Brandon P

    2018-01-01

    Simulation training has been shown to be an effective teaching tool. Learner management of an intraoperative crisis such as a major cerebrovascular bleed requires effective teamwork, communication, and implementation of key skill sets at appropriate time points. This study establishes a first of a kind simulation experience in a neurosurgery/anesthesia resident (learners) team working together to manage an intraoperative crisis. Using a cadaveric cavernous carotid injury perfusion model, 7 neurosurgery and 6 anesthesia learners, were trained on appropriate vascular injury management using an endonasal endoscopic technique. Learners were evaluated on communication skills, crisis management algorithms, and implementation of appropriate skill sets at the right time. A preanatomic and postanatomic examination and postsimulation survey was administered to neurosurgery learners. Anesthesia learners provided posttraining evaluation through a tailored realism and teaching survey. Neurosurgery learners' anatomic examination score improved from presimulation (33.89%) to postsimulation (86.11%). No significant difference between learner specialties was observed for situation awareness, decision making, communications and teamwork, or leadership evaluations. Learners reported the simulation realistic, beneficial, and highly instructive. Realistic, first of kind, clinical simulation scenarios were presented to a neurosurgery/anesthesia resident team who worked together to manage an intraoperative crisis. Learners were effectively trained on crisis management, the importance of communication, and how to develop algorithms for future implementation in difficult scenarios. Learners were highly satisfied with the simulation training experience and requested that it be integrated more consistently into their residency training programs.

  13. Preliminary Results on the Experimental Investigation of the Structure Functions of Bound Nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Bodek, Arie [Univ. of Rochester, NY (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-08-01

    We present preliminary results on an experimental study of the nuclear modification of the longitudinal ($\\sigma_L$) and transverse ($\\sigma_T$) structure functions of nucleons bound in nuclear targets. The origin of these modifications (commonly referred as as the EMC effect) is not fully understood. Our measurements of R= $\\sigma_L / \\sigma_T$ for nuclei ($R_A$) and for deuterium ($R_D$) indicate that nuclear modifications of the structure functions of bound nucleons are different for the longitudinal and transverse structure functions, and that contrary to expectation from several theoretical models, $R_A< R_D$.

  14. National survey on postoperative care and treatment circuits in neurosurgery.

    Science.gov (United States)

    Valero, R; Carrero, E; Fàbregas, N; Iturri, F; Saiz-Sapena, N; Valencia, L

    2017-10-01

    The analysis of surgical processes should be a standard of health systems. We describe the circuit of care and postoperative treatment for neurosurgical interventions in the centres of our country. From June to October 2014, a survey dealing with perioperative treatments and postoperative circuits after neurosurgical procedures was sent to the chiefs of Anaesthesiology of 73 Spanish hospitals with neurosurgery and members of the Neuroscience Section of SEDAR. We obtained 45 responses from 30 centres (41.09%). Sixty percent of anaesthesiologists perform preventive locoregional analgesic treatment. Pain intensity is systematically assessed by 78%. Paracetamol, non-steroidal anti-inflammatory and morphine combinations are the most commonly used. A percentage of 51.1 are aware of the incidence of postoperative nausea after craniotomy and 86.7% consider multimodal prophylaxis to be necessary. Dexamethasone is given as antiemetic (88.9%) and/or anti-oedema treatment (68.9%). A percentage of 44.4 of anaesthesiologists routinely administer anticonvulsive prophylaxis in patients with supratentorial tumours (levetiracetam, 88.9%), and 73.3% of anaesthesiologists have postoperative surveillance protocols. The anaesthesiologist (73.3%) decides the patient's destination, which is usually ICU (83.3%) or PACU (50%). Postoperative neurological monitoring varied according to the type of intervention, although strength and sensitivity were explored in between 70-80%. There is great variability in the responses, probably attributable to the absence of guidelines, different structures and hospital equipment, type of surgery and qualified personnel. We need consensual protocols to standardize the treatment and the degree of monitoring needed during the postoperative period. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Smartphones in remote medicine and daily neurosurgery: The Sabah update.

    Science.gov (United States)

    Perumall, Vinodh Vayara; Sellamuthu, Pulivendhan; Harun, Rahmat; Zenian, Mohd Sofan

    2015-01-01

    Healthcare costs continue to rise every day as the demand outgrows the supply of surgeons. The application of telephone consultation for immediate management is needed as most neurosurgeons are technology orientated. This enables a specialist at a remote mobile site to receive the necessary information and reduce transmission time, from the second the patient is seen till the management is obtained. We conducted a survey on smartphone ownership among doctors and gathered cases that needed neurosurgical input from 1(st) November 2012 till 30(th) April 2013 from all 24 district hospitals in Sabah, Malaysia. The percentage of smartphone ownership among doctors surveyed and usage of it for remote and daily medicine at various departments at Queen Elizabeth Hospital, Kota Kinabalu, which shows at least 90% smartphone ownership and proves 100% ownership of cross-platform instant messaging applications and its usage for remote and daily medicine. It also proves to be a more popular mode of referral compared to "teleconsultation" (TC). In Sabah, the TC service is used for remote medical consultation and only available at four hospitals. The sender needs direct access to a computer with the TC software, and it causes delay whereas doctors using smartphones will just need to discuss the case on the spot and obtain the appropriate management within minutes. Smartphone usage is also important in daily neurosurgery especially at the department level to promote efficient communication, organization, and interaction between all the staff. As for the department's administrative sector, it is useful to notify if anyone is on leave, attending courses or even meetings as the shortage can be avoided, and redistribution easily done. It also allows us to transfer simple intra-departmental data at any time, and any place whenever required. With all the given fact, it is clear that a day without utilizing this service in our daily life will leave us handicapped and struggling with time

  16. Sensors management in robotic neurosurgery: the ROBOCAST project.

    Science.gov (United States)

    Vaccarella, Alberto; Comparetti, Mirko Daniele; Enquobahrie, Andinet; Ferrigno, Giancarlo; De Momi, Elena

    2011-01-01

    Robot and computer-aided surgery platforms bring a variety of sensors into the operating room. These sensors generate information to be synchronized and merged for improving the accuracy and the safety of the surgical procedure for both patients and operators. In this paper, we present our work on the development of a sensor management architecture that is used is to gather and fuse data from localization systems, such as optical and electromagnetic trackers and ultrasound imaging devices. The architecture follows a modular client-server approach and was implemented within the EU-funded project ROBOCAST (FP7 ICT 215190). Furthermore it is based on very well-maintained open-source libraries such as OpenCV and Image-Guided Surgery Toolkit (IGSTK), which are supported from a worldwide community of developers and allow a significant reduction of software costs. We conducted experiments to evaluate the performance of the sensor manager module. We computed the response time needed for a client to receive tracking data or video images, and the time lag between synchronous acquisition with an optical tracker and ultrasound machine. Results showed a median delay of 1.9 ms for a client request of tracking data and about 40 ms for US images; these values are compatible with the data generation rate (20-30 Hz for tracking system and 25 fps for PAL video). Simultaneous acquisitions have been performed with an optical tracking system and US imaging device: data was aligned according to the timestamp associated with each sample and the delay was estimated with a cross-correlation study. A median value of 230 ms delay was calculated showing that realtime 3D reconstruction is not feasible (an offline temporal calibration is needed), although a slow exploration is possible. In conclusion, as far as asleep patient neurosurgery is concerned, the proposed setup is indeed useful for registration error correction because the brain shift occurs with a time constant of few tens of minutes.

  17. Experimentally reduced hip abductor function during walking: Implications for knee joint loads

    DEFF Research Database (Denmark)

    Henriksen, Marius; Aaboe, Jens; Simonsen, Erik B

    2009-01-01

    medius (GM) muscle would lead to increased external knee adduction moment during level walking in healthy subjects. Reduced GM muscle function was induced experimentally, by means of intramuscular injections of hypertonic saline that produced an intense short-term muscle pain and reduced muscle function......Hip and knee functions are intimately connected and reduced hip abductor function might play a role in development of knee osteoarthritis (OA) by increasing the external knee adduction moment during walking. The purpose of this study was to test the hypothesis that reduced function of the gluteus......-dimensional trunk and lower extremity joint kinematics and kinetics. Surface electromyography (EMG) of the glutei, quadriceps, and hamstring muscles were also measured. The peak GM EMG activity had temporal concurrence with peaks in frontal plane moments at both hip and knee joints. The EMG activity in the GM...

  18. Neurosurgery in Turkish poetry: three poets, two poems and two neurosurgeons.

    Science.gov (United States)

    Kahilogullari, Gokmen

    2015-01-01

    Poems are essential in art and vital organs in literature. Similarly, surgery (and neurosurgery) is also regarded to be an art in medicine. From Hippocrates to nowadays, there is a debate on whether medicine -especially surgery- is a kind of an art or a field of science or a combination of both. This close relation becomes clearer during the practice of surgery, especially in neurosurgery. Herein, the relation between Turkish poetry and Turkish neurosurgery is being presented by researching the interesting and exciting stories about three poets (Can Yücel, Hasan Hüseyin Korkmazgil, Nazım Hikmet), their poems; and two Turkish neurosurgeons (Gazi Yaşargil, Yücel Kanpolat).

  19. Clinical Outcomes of Wulingsan Subtraction Decoction Treatment of Postoperative Brain Edema and Fever as a Complication of Glioma Neurosurgery

    Directory of Open Access Journals (Sweden)

    Wei-rong Jin

    2016-01-01

    Full Text Available Objective. To evaluate the efficacy of Wulingsan subtraction (五苓散加减 WLSS decoction in the treatment of postoperative brain edema and fever as a complication of glioma neurosurgery. Methods. This retrospective study was conducted at the Department of Neurosurgery of Liaocheng People’s Hospital. Patients hospitalized between March 2011 and December 2014 were divided into three groups: Group A received WLSS oral liquid (50 mL, twice a day; Group B received an intravenous infusion of mannitol; and Group C received WLSS combined with mannitol (n=30 patients per group. All patients were treated for 10 days continuously. Therapeutic efficacy was evaluated by measuring body temperature and indicators of renal function before and 3, 5, and 10 days after treatment. Results. Compared to the other two groups, significantly greater clinical efficacy was observed in the patients treated with mannitol (Group B; P<0.05, although marked clinical efficacy was also observed over time in patients treated with WLSS (Group A. After 5 days, the quantifiable effects of the WLSS and mannitol combination group (Group C were substantial (P<0.05. The renal damage in Group B was more obvious after 5 days and 10 days. Conclusion. Compared with mannitol treatment alone, WLSS combined with mannitol induced a more rapid reduction in body temperature. Our findings suggest that patients should be started on mannitol for 3 days and then switched to WLSS to achieve obvious antipyretic effects and protect renal function. This method of treatment should be considered for clinical applications.

  20. Byron Stookey: "the old lion"--an unsung giant of neurosurgery.

    Science.gov (United States)

    Kaufman, H H; Goodrich, J T

    1997-02-01

    BYRON POLK STOOKEY, an outstanding clinician and teacher, served as Director and Chief of Neurosurgery at the Neurological Institute of New York Columbia-Presbyterian Medical Center. Highlights of his clinical contributions include improved peripheral nerve and spine surgery and subtemporal trigeminal nerve section for tic douloureux. Through diverse activities in both the political and academic arenas of patient care, education, and research, stookey helped to build and strengthen neurosurgery between the world wars and helped to prepare the foundation for the accomplishments of recent decades.

  1. [Characteristics of perioperative period in Xenon-based combined general anaesthesia in neurosurgery].

    Science.gov (United States)

    Viatkin, A A; Petrosian, L G; Mizikov, V M; Vasil'ev, S A

    2013-01-01

    Neuroprotection could be the aim to use Xenon for general anesthesia. However the experience of Xenon anesthesia in neurosurgery is quite limited. The appraisal of Xenon based anesthesia was accomplished in 12 patients during various brain surgery. Xe in concentration 65% was used to maintenance of anesthesia, other medication was avoided. As a resuIt there were 8 cases of arterial hypertension and 2 cases of superficial hypnotic state. Excitation (n = 3), hyperdynamic reaction (n = 8), PONV (n = 8) were detected in early postoperative period. An analysis of this study suggests a conclusion that studied method of Xenon-based anesthesia is inexpedient for neurosurgery.

  2. Comparison between experimental and predicted specific absorption rate of functionalized iron oxide nanoparticle suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yuan [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Tasciuc, Diana-Andra Borca, E-mail: borcad@rpi.edu [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2011-10-15

    Radio-frequency heated magnetic nanoaparticle suspensions have potential applications in cancer hyperthermia. To optimize these systems for hyperthermia applications it is important to be able to predict how their heat generation or specific absorption rate (SAR) is influenced by various factors, including nanoparticle coating or functionalization and aggregation. However, at present it is unclear how well-existing models predict experimental SAR results. Direct comparisons between predicted and measured SAR are scarce, despite an abundance of works reporting on heat generation rate of various magnetic nanoparticles suspensions. The main objective of this paper is to experimentally assess the validity of current models for SAR and extract information on the effects of coating and aggregation on heat generation rate. In this context, AC susceptibility and magnetization of suspensions of uncoated particles, as well as particles with aminosilane and carboxymethyl-dextran functionalizations, were measured. These properties were then used to predict the heat generation rate in alternating magnetic field starting from first principles, which was then compared to measured SAR. It was found that experimental SAR agrees relatively well with predictions (by a factor of two) when using experimental susceptibility values for the SAR calculation. However, for uncoated and amine-functionalized particles poor agreement (more than an order of magnitude difference) was found when the experimental susceptibility was substituted with predictions based on the Debye model. This apparent discrepancy is attributed to dipolar interactions between nanoparticles within aggregates in these samples, which enhances the imaginary part of the susceptibility and, consequently, the SAR values. The results also suggest that the thermal resistance effect of the coating has little influence on the SAR. - Highlights: > Thermal resistance of nanoparticle coating has little impact on heat dissipation

  3. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Ploetz, Elizabeth A.; Smith, Paul E. [Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506 (United States)

    2015-03-07

    Kirkwood-Buff or Fluctuation Solution Theory can be used to provide experimental pair fluctuations, and/or integrals over the pair distribution functions, from experimental thermodynamic data on liquid mixtures. Here, this type of approach is used to provide triplet and quadruplet fluctuations, and the corresponding integrals over the triplet and quadruplet distribution functions, in a purely thermodynamic manner that avoids the use of structure factors. The approach is then applied to binary mixtures of water + methanol and benzene + methanol over the full composition range under ambient conditions. The observed correlations between the different species vary significantly with composition. The magnitude of the fluctuations and integrals appears to increase as the number of the most polar molecule involved in the fluctuation or integral also increases. A simple physical picture of the fluctuations is provided to help rationalize some of these variations.

  4. Frequency response function of motors for switching noise energy with a new experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunsu [Ensemble Center for Automotive Research, Seoul (Korea, Republic of); Yoon, Jong-Yun [Incheon National University, Incheon (Korea, Republic of)

    2017-06-15

    Switching energy in electrical vehicles can create serious noise from the motors. However, the characteristics of switching noise in vehicle motors are not clear due to the complexity of measuring them. This study proposes a new experimental method to investigate the switching noise energy of a vehicle motor based on frequency response functions. A function generator-amplifier system is used to gen- erate the switching energy instead of the complex battery-inverter system that has previously been used to examine the noise energy characteristics. Even though newly adapted experimental method is simple, the switching noise energy was explicitly investigated under various input signals. Thus, this simple new method can be used to investigate the dynamic characteristics of noise energy in a vehicle motor.

  5. Experimental-confirmation and functional-annotation of predicted proteins in the chicken genome

    Directory of Open Access Journals (Sweden)

    McCarthy Fiona M

    2007-11-01

    Full Text Available Abstract Background The chicken genome was sequenced because of its phylogenetic position as a non-mammalian vertebrate, its use as a biomedical model especially to study embryology and development, its role as a source of human disease organisms and its importance as the major source of animal derived food protein. However, genomic sequence data is, in itself, of limited value; generally it is not equivalent to understanding biological function. The benefit of having a genome sequence is that it provides a basis for functional genomics. However, the sequence data currently available is poorly structurally and functionally annotated and many genes do not have standard nomenclature assigned. Results We analysed eight chicken tissues and improved the chicken genome structural annotation by providing experimental support for the in vivo expression of 7,809 computationally predicted proteins, including 30 chicken proteins that were only electronically predicted or hypothetical translations in human. To improve functional annotation (based on Gene Ontology, we mapped these identified proteins to their human and mouse orthologs and used this orthology to transfer Gene Ontology (GO functional annotations to the chicken proteins. The 8,213 orthology-based GO annotations that we produced represent an 8% increase in currently available chicken GO annotations. Orthologous chicken products were also assigned standardized nomenclature based on current chicken nomenclature guidelines. Conclusion We demonstrate the utility of high-throughput expression proteomics for rapid experimental structural annotation of a newly sequenced eukaryote genome. These experimentally-supported predicted proteins were further annotated by assigning the proteins with standardized nomenclature and functional annotation. This method is widely applicable to a diverse range of species. Moreover, information from one genome can be used to improve the annotation of other genomes and

  6. Experimental demonstration of programmable multi-functional spin logic cell based on spin Hall effect

    Science.gov (United States)

    Zhang, X.; Wan, C. H.; Yuan, Z. H.; Fang, C.; Kong, W. J.; Wu, H.; Zhang, Q. T.; Tao, B. S.; Han, X. F.

    2017-04-01

    Confronting with the gigantic volume of data produced every day, raising integration density by reducing the size of devices becomes harder and harder to meet the ever-increasing demand for high-performance computers. One feasible path is to actualize more logic functions in one cell. In this respect, we experimentally demonstrate a prototype spin-orbit torque based spin logic cell integrated with five frequently used logic functions (AND, OR, NOT, NAND and NOR). The cell can be easily programmed and reprogrammed to perform desired function. Furthermore, the information stored in cells is symmetry-protected, making it possible to expand into logic gate array where the cell can be manipulated one by one without changing the information of other undesired cells. This work provides a prospective example of multi-functional spin logic cell with reprogrammability and nonvolatility, which will advance the application of spin logic devices.

  7. Experimental Measurement of Relative Permeability Functions for Fuel Cell GDL Materials

    KAUST Repository

    Hussaini, Irfan

    2009-01-01

    Gas diffusion layer in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex-situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented. Significant departure from the generally assumed cubic function of saturation is observed. ©The Electrochemical Society.

  8. THE INFLUENCE OF THE EXPERIMENTAL PROGRAMME OF PHYSICAL EDUCATION CURRICULUM ON PUPILS FUNCTIONAL ABILITIES

    Directory of Open Access Journals (Sweden)

    Nevenka Zrnzević

    2010-09-01

    Full Text Available The purpose of this research is to determine how much is the specially suggested experimental program of physical education, with increased demands and application of additional exercises, influenting the functional abbilities. The applied experimental program was composed of athletics exercises, sports games, exercises on the pieces of equipment and on the floor, rhythmics and dancing exercises. Six metrical instruments were used for evaluation of functional abbilities of schoolboys and schoolgirls. The experimental program was carried out on the sample of 106 first-grade pupils of the elementary school, age of 7 years ± 6 months. Basic statistic parametars were calculated by processing of data during initial and final measuring. Final data processing included only the examinees that participated at initial and final measurement. Multivariant and univariant analisys of variance for repeated measures (MANOVA and ANOVA – repeated measures were applied for determination of eventual differences between initial and final measuring. Based on retrieved results it could be concluded that specially programed performance of physical education had a significant influence on changing the most functional abbilities of pupils.

  9. Downregulation of FoxC2 Increased Susceptibility to Experimental Colitis: Influence of Lymphatic Drainage Function?

    Science.gov (United States)

    Becker, Felix; Potepalov, Sergey; Shehzahdi, Romana; Bernas, Michael; Witte, Marlys; Abreo, Fleurette; Traylor, James; Orr, Wayne A.; Tsunoda, Ikuo

    2015-01-01

    Background: Although inflammation-induced expansion of the intestinal lymphatic vasculature (lymphangiogenesis) is known to be a crucial event in limiting inflammatory processes, through clearance of interstitial fluid and immune cells, considerably less is known about the impact of an impaired lymphatic clearance function (as seen in inflammatory bowel diseases) on this cascade. We aimed to investigate whether the impaired intestinal lymphatic drainage function observed in FoxC2(+/−) mice would influence the course of disease in a model of experimental colitis. Methods: Acute dextran sodium sulfate colitis was induced in wild-type and haploinsufficient FoxC2(+/−) mice, and survival, disease activity, colonic histopathological injury, neutrophil, T-cell, and macrophage infiltration were evaluated. Functional and structural changes in the intestinal lymphatic vessel network were analyzed, including submucosal edema, vessel morphology, and lymphatic vessel density. Results: We found that FoxC2 downregulation in FoxC2(+/−) mice significantly increased the severity and susceptibility to experimental colitis, as displayed by lower survival rates, increased disease activity, greater histopathological injury, and elevated colonic neutrophil, T-cell, and macrophage infiltration. These findings were accompanied by structural (dilated torturous lymphatic vessels) and functional (greater submucosal edema, higher immune cell burden) changes in the intestinal lymphatic vasculature. Conclusions: These results indicate that sufficient lymphatic clearance plays a crucial role in limiting the initiation and perpetuation of experimental colitis and those disturbances in the integrity of the intestinal lymphatic vessel network could intensify intestinal inflammation. Future therapies might be able to exploit these processes to restore and maintain adequate lymphatic clearance function in inflammatory bowel disease. PMID:25822012

  10. Downregulation of FoxC2 Increased Susceptibility to Experimental Colitis: Influence of Lymphatic Drainage Function?

    Science.gov (United States)

    Becker, Felix; Potepalov, Sergey; Shehzahdi, Romana; Bernas, Michael; Witte, Marlys; Abreo, Fleurette; Traylor, James; Orr, Wayne A; Tsunoda, Ikuo; Alexander, Jonathan Steven

    2015-06-01

    Although inflammation-induced expansion of the intestinal lymphatic vasculature (lymphangiogenesis) is known to be a crucial event in limiting inflammatory processes, through clearance of interstitial fluid and immune cells, considerably less is known about the impact of an impaired lymphatic clearance function (as seen in inflammatory bowel diseases) on this cascade. We aimed to investigate whether the impaired intestinal lymphatic drainage function observed in FoxC2 mice would influence the course of disease in a model of experimental colitis. Acute dextran sodium sulfate colitis was induced in wild-type and haploinsufficient FoxC2 mice, and survival, disease activity, colonic histopathological injury, neutrophil, T-cell, and macrophage infiltration were evaluated. Functional and structural changes in the intestinal lymphatic vessel network were analyzed, including submucosal edema, vessel morphology, and lymphatic vessel density. We found that FoxC2 downregulation in FoxC2 mice significantly increased the severity and susceptibility to experimental colitis, as displayed by lower survival rates, increased disease activity, greater histopathological injury, and elevated colonic neutrophil, T-cell, and macrophage infiltration. These findings were accompanied by structural (dilated torturous lymphatic vessels) and functional (greater submucosal edema, higher immune cell burden) changes in the intestinal lymphatic vasculature. These results indicate that sufficient lymphatic clearance plays a crucial role in limiting the initiation and perpetuation of experimental colitis and those disturbances in the integrity of the intestinal lymphatic vessel network could intensify intestinal inflammation. Future therapies might be able to exploit these processes to restore and maintain adequate lymphatic clearance function in inflammatory bowel disease.

  11. A Comparison of Experimental Functional Analysis and the Questions about Behavioral Function (QABF) in the Assessment of Challenging Behavior of Individuals with Autism

    Science.gov (United States)

    Healy, Olive; Brett, Denise; Leader, Geraldine

    2013-01-01

    We compared two functional behavioral assessment methods: the Questions About Behavioral Function (QABF; a standardized test) and experimental functional analysis (EFA) to identify behavioral functions of aggressive/destructive behavior, self-injurious behavior and stereotypy in 32 people diagnosed with autism. Both assessments found that self…

  12. Examining the function of problem behavior in fragile X syndrome: preliminary experimental analysis.

    Science.gov (United States)

    Langthorne, Paul; McGill, Peter; O'Reilly, Mark F; Lang, Russell; Machalicek, Wendy; Chan, Jeffrey Michael; Rispoli, Mandy

    2011-01-01

    Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis methodology with 8 children with fragile X. No child met criteria for attention-maintained problem behavior, 5 children met criteria for escape-maintained problem behavior, and 4 children met criteria for tangible-maintained problem behavior. Results are discussed and compared with previous findings on the function of problem behavior in fragile X syndrome, and implications for intervention are discussed. It is noted that the external validity of these findings is limited by the small sample size.

  13. Experiential Learning of Robotics Fundamentals Based on a Case Study of Robot-Assisted Stereotactic Neurosurgery

    Science.gov (United States)

    Faria, Carlos; Vale, Carolina; Machado, Toni; Erlhagen, Wolfram; Rito, Manuel; Monteiro, Sérgio; Bicho, Estela

    2016-01-01

    Robotics has been playing an important role in modern surgery, especially in procedures that require extreme precision, such as neurosurgery. This paper addresses the challenge of teaching robotics to undergraduate engineering students, through an experiential learning project of robotics fundamentals based on a case study of robot-assisted…

  14. Neurosurgical Skills Assessment: Measuring Technical Proficiency in Neurosurgery Residents Through Intraoperative Video Evaluations.

    Science.gov (United States)

    Sarkiss, Christopher A; Philemond, Steven; Lee, James; Sobotka, Stanislaw; Holloway, Terrell D; Moore, Maximillian M; Costa, Anthony B; Gordon, Errol L; Bederson, Joshua B

    2016-05-01

    Although technical skills are fundamental in neurosurgery, there is little agreement on how to describe, measure, or compare skills among surgeons. The primary goal of this study was to develop a quantitative grading scale for technical surgical performance that distinguishes operator skill when graded by domain experts (residents, attendings, and nonsurgeons). Scores provided by raters should be highly reliable with respect to scores from other observers. Neurosurgery residents were fitted with a head-mounted video camera while performing craniotomies under attending supervision. Seven videos, 1 from each postgraduate year (PGY) level (1-7), were anonymized and scored by 16 attendings, 8 residents, and 7 nonsurgeons using a grading scale. Seven skills were graded: incision, efficiency of instrument use, cauterization, tissue handling, drilling/craniotomy, confidence, and training level. A strong correlation was found between skills score and PGY year (P Technical skills of neurosurgery residents recorded during craniotomy can be measured with high interrater reliability. Surgeons and nonsurgeons alike readily distinguish different skill levels. This type of assessment could be used to coach residents, to track performance over time, and potentially to compare skill levels. Developing an objective tool to evaluate surgical performance would be useful in several areas of neurosurgery education. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. TREATMENT OF SINGLE BRAIN METASTASIS - RADIOTHERAPY ALONE OR COMBINED WITH NEUROSURGERY

    NARCIS (Netherlands)

    VECHT, CJ; HAAXMAREICHE, H; NOORDIJK, EM; PADBERG, GW; VOORMOLEN, JHC; HOEKSTRA, FH; TANS, JTJ; LAMBOOIJ, N; METSAARS, JAL; WATTENDORFF, AR; BRAND, R; HERMANS, J

    Most patients treated for single or multiple brain metastases die from progression of extracranial tumor activity. This makes it uncertain whether the combination of neurosurgery and radiotherapy for treatment of single brain metastasis will lead to better results than less invasive treatment with

  16. Frugal Malleable Micro-Dissectors and Arachnoid Knives for Micro-neurosurgery.

    Science.gov (United States)

    Jha, Deepak K

    2018-01-25

    Like most of the other medical and surgical fields, neurosurgery too has changed drastically in last couple of decades, especially in the fields of understanding, instrumentation and equipments. Safety, scope of treating initially considered non-treatable neurosurgical conditions, and prognosis of most of the neurosurgical procedures have improved significantly. Barrage of newer instruments and equipments are exponential for last many years leading to tremendous cost escalation of the treatment. However, equitable distribution of the neurosurgical services in the society is far from reality. There were many tools and techniques being used by our teachers and forefathers of neurosurgery, which we need to look back and learn their innovative ways to accomplish difficult procedures without advanced tools and techniques. Micro-neurosurgery is considered highly skilled job and instruments used for it are equally delicate, precise and at the same time costlier than similar macro-instruments of neurosurgery. Author shares his experience of using frugal innovative techniques and tools, for making stainless steel wire and plate-micro-dissectors, equally effective for microneurosurgical procedures and can be helpful for neurosurgeons working in the settings of scarce resources. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. The Spectrum of Altmetrics in Neurosurgery: The Top 100 "Trending" Articles in Neurosurgical Journals.

    Science.gov (United States)

    Wang, Justin; Alotaibi, Naif M; Ibrahim, George M; Kulkarni, Abhaya V; Lozano, Andres M

    2017-07-01

    Social media are increasingly used for the dissemination of scientific publications by most medical journals. The role of social media in increasing awareness of published works in neurosurgery has not been previously explored. Here, we present a qualitative analysis of the highest trending works in neurosurgery along with a correlation analysis with their social media metrics. We performed a comprehensive search for neurosurgical publications using the Altmetric database. The Altmetric database provides a weighted total score of all online mentions for an article received on Facebook, Twitter, blogs, and mainstream media sources. Our search was limited to articles published within the social media era (January 2010-January 2017). Descriptive and correlational statistics were performed for all articles. The top 100 articles in altmetrics were selected for qualitative analysis. A total of 5794 articles were included in this study. The average Altmetric score in neurosurgical articles was 4.7 (standard deviation ±22.4). Journals with a social media account had significantly higher Altmetric scores for their articles compared with those without an account (P articles in altmetrics belonged primarily to the Journal of Neurosurgery (33%) followed by Neurosurgery (29%). This is the first study that details the spectrum of Altmetric scores among neurosurgical journals. Social media presence for journals is important for greater outreach and engagement. Prediction of traditional citation using altmetrics data requires a future prospective study. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Elevated Amylase and Lipase Levels in the Neurosurgery Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Cheng-Chia Lee

    2010-01-01

    Conclusion: Various neurosurgery events and diagnoses may lead to different degrees of serum pancreatic enzyme elevation. Patients with elevated pancreatic enzyme levels have a higher mortality rate than those with normal enzyme levels. We believe that abdominal CT should be indicated for patients if their amylase levels are more than 3-fold the upper normal limit and lipase levels are more than 5-fold.

  19. Experimental and theoretical investigation of thermal conductivity of ethylene glycol containing functionalized single walled carbon nanotubes

    Science.gov (United States)

    Hemmat Esfe, Mohammad; Firouzi, Masoumeh; Afrand, Masoud

    2018-01-01

    In this paper, functionalized single walled carbon nanotubes (FSWCNTs) were suspended in Ethylene Glycol (EG) at different volume fractions. A KD2 pro thermal conductivity meter was used to measure the thermal conductivity in the temperature range from 30 to 50 °C. Nanofluids were prepared in solid volume fraction of 0.02, 0.05, 0.075, 0.1, 0.25, 0.5 and, 0.75%. Experimental results revealed that the thermal conductivity of the nanofluid is a non-linear function of temperature and SWCNTs volume fraction in the range of this investigation. Thermal conductivity increases with temperature and nanoparticles volume fraction as usual for this type of nanofluid. Maximum increment in thermal conductivity of the nanofluids was found to be about 45% at 0.75 vol fractions loading at 50 °C. Finally, a new correlation based on artificial neural network (ANN) approach has been proposed for SWCNT-EG thermal conductivity in terms of nanoparticles volume fraction and temperature using the experimental data. Used ANN approach has estimated the experimental values of thermal conductivity with the absolute average relative deviation lower than 0.9%, mean square error of 3.67 × 10-5 and regression coefficient of 0.9989. Comparison between the suggested techniques with various used correlation in the literatures established that the ANN approach is better to other presented methods and therefore can be proposed as a useful means for predicting of the nanofluids thermal conductivity.

  20. Developing a new model for the invention and translation of neurotechnologies in academic neurosurgery.

    Science.gov (United States)

    Leuthardt, Eric C

    2013-01-01

    There is currently an acceleration of new scientific and technical capabilities that create new opportunities for academic neurosurgery. To engage these changing dynamics, the Center for Innovation in Neuroscience and Technology (CINT) was created on the premise that successful innovation of device-related ideas relies on collaboration between multiple disciplines. The CINT has created a unique model that integrates scientific, medical, engineering, and legal/business experts to participate in the continuum from idea generation to translation. To detail the method by which this model has been implemented in the Department of Neurological Surgery at Washington University in St. Louis and the experience that has been accrued thus far. The workflow is structured to enable cross-disciplinary interaction, both intramurally and extramurally between academia and industry. This involves a structured method for generating, evaluating, and prototyping promising device concepts. The process begins with the "invention session," which consists of a structured exchange between inventors from diverse technical and medical backgrounds. Successful ideas, which pass a separate triage mechanism, are then sent to industry-sponsored multidisciplinary fellowships to create functioning prototypes. After 3 years, the CINT has engaged 32 clinical and nonclinical inventors, resulting in 47 ideas, 16 fellowships, and 12 patents, for which 7 have been licensed to industry. Financial models project that if commercially successful, device sales could have a notable impact on departmental revenue. The CINT is a model that supports an integrated approach from the time an idea is created through its translational development. To date, the approach has been successful in creating numerous concepts that have led to industry licenses. In the long term, this model will create a novel revenue stream to support the academic neurosurgical mission.

  1. Automatic deformable MR-ultrasound registration for image-guided neurosurgery.

    Science.gov (United States)

    Rivaz, Hassan; Chen, Sean Jy-Shyang; Collins, D Louis

    2015-02-01

    In this work, we present a novel algorithm for registration of 3-D volumetric ultrasound (US) and MR using Robust PaTch-based cOrrelation Ratio (RaPTOR). RaPTOR computes local correlation ratio (CR) values on small patches and adds the CR values to form a global cost function. It is therefore invariant to large amounts of spatial intensity inhomogeneity. We also propose a novel outlier suppression technique based on the orientations of the RaPTOR gradients. Our deformation is modeled with free-form cubic B-splines. We analytically derive the derivatives of RaPTOR with respect to the transformation, i.e., the displacement of the B-spline nodes, and optimize RaPTOR using a stochastic gradient descent approach. RaPTOR is validated on MR and tracked US images of neurosurgery. Deformable registration of the US and MR images acquired, respectively, preoperation and postresection is of significant clinical significance, but challenging due to, among others, the large amount of missing correspondences between the two images. This work is also novel in that it performs automatic registration of this challenging dataset. To validate the results, we manually locate corresponding anatomical landmarks in the US and MR images of tumor resection in brain surgery. Compared to rigid registration based on the tracking system alone, RaPTOR reduces the mean initial mTRE over 13 patients from 5.9 to 2.9 mm, and the maximum initial TRE from 17.0 to 5.9 mm. Each volumetric registration using RaPTOR takes about 30 sec on a single CPU core. An important challenge in the field of medical image analysis is the shortage of publicly available dataset, which can both facilitate the advancement of new algorithms to clinical settings and provide a benchmark for comparison. To address this problem, we will make our manually located landmarks available online.

  2. Virtual reality training in neurosurgery: Review of current status and future applications.

    Science.gov (United States)

    Alaraj, Ali; Lemole, Michael G; Finkle, Joshua H; Yudkowsky, Rachel; Wallace, Adam; Luciano, Cristian; Banerjee, P Pat; Rizzi, Silvio H; Charbel, Fady T

    2011-01-01

    Over years, surgical training is changing and years of tradition are being challenged by legal and ethical concerns for patient safety, work hour restrictions, and the cost of operating room time. Surgical simulation and skill training offer an opportunity to teach and practice advanced techniques before attempting them on patients. Simulation training can be as straightforward as using real instruments and video equipment to manipulate simulated "tissue" in a box trainer. More advanced virtual reality (VR) simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations. A PubMed review of the literature was performed for the MESH words "Virtual reality, "Augmented Reality", "Simulation", "Training", and "Neurosurgery". Relevant articles were retrieved and reviewed. A review of the literature was performed for the history, current status of VR simulation in neurosurgery. Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and credential surgeons as technically competent. The number of published literature discussing the application of VR simulation in neurosurgery training has evolved over the last decade from data visualization, including stereoscopic evaluation to more complex augmented reality models. With the revolution of computational analysis abilities, fully immersive VR models are currently available in neurosurgery training. Ventriculostomy catheters insertion, endoscopic and endovascular simulations are used in neurosurgical residency training centers across the world. Recent studies have shown the coloration of proficiency with those simulators and levels of experience in the real world. Fully immersive technology is starting to be applied to the practice of neurosurgery. In the near future, detailed VR neurosurgical modules

  3. Integration of patient specific modeling and advanced image processing techniques for image-guided neurosurgery

    Science.gov (United States)

    Archip, Neculai; Fedorov, Andriy; Lloyd, Bryn; Chrisochoides, Nikos; Golby, Alexandra; Black, Peter M.; Warfield, Simon K.

    2006-03-01

    A major challenge in neurosurgery oncology is to achieve maximal tumor removal while avoiding postoperative neurological deficits. Therefore, estimation of the brain deformation during the image guided tumor resection process is necessary. While anatomic MRI is highly sensitive for intracranial pathology, its specificity is limited. Different pathologies may have a very similar appearance on anatomic MRI. Moreover, since fMRI and diffusion tensor imaging are not currently available during the surgery, non-rigid registration of preoperative MR with intra-operative MR is necessary. This article presents a translational research effort that aims to integrate a number of state-of-the-art technologies for MRI-guided neurosurgery at the Brigham and Women's Hospital (BWH). Our ultimate goal is to routinely provide the neurosurgeons with accurate information about brain deformation during the surgery. The current system is tested during the weekly neurosurgeries in the open magnet at the BWH. The preoperative data is processed, prior to the surgery, while both rigid and non-rigid registration algorithms are run in the vicinity of the operating room. The system is tested on 9 image datasets from 3 neurosurgery cases. A method based on edge detection is used to quantitatively validate the results. 95% Hausdorff distance between points of the edges is used to estimate the accuracy of the registration. Overall, the minimum error is 1.4 mm, the mean error 2.23 mm, and the maximum error 3.1 mm. The mean ratio between brain deformation estimation and rigid alignment is 2.07. It demonstrates that our results can be 2.07 times more precise then the current technology. The major contribution of the presented work is the rigid and non-rigid alignment of the pre-operative fMRI with intra-operative 0.5T MRI achieved during the neurosurgery.

  4. The Experimental Tobacco Marketplace I: Substitutability as a Function of the Price of Conventional Cigarettes.

    Science.gov (United States)

    Quisenberry, Amanda J; Koffarnus, Mikhail N; Hatz, Laura E; Epstein, Leonard H; Bickel, Warren K

    2016-07-01

    Behavioral economic studies of nicotine product consumption have traditionally examined substitution between two products and rarely examined substitution with more products. Increasing numbers of tobacco products available for commercial sale leads to more possible cross-product interactions, indicating a need to examine substitution in more complex arrangements that closely mirror the tobacco marketplace. The experimental tobacco marketplace (ETM) is an experimental online store that displays pictures, information, and prices for several tobacco products. Smokers were endowed with an account balance based on their weekly tobacco purchases. Participants then made potentially real purchases for seven (Experiment 1) or six (Experiment 2) tobacco/nicotine products under four price conditions for conventional cigarettes while prices for other products remained constant. Smokers returned 1 week later to report tobacco/nicotine use and return unused products for a refund. In Experiment 1 (n = 22), cigarette purchasing decreased as a function of price. Substitution was greatest for electronic cigarettes and cigarillos and significant for electronic cigarettes. Experiment 2 (n = 34) was a replication of Experiment 1, but with cigarillos unavailable in the ETM. In Experiment 2, cigarette purchases decreased as a function of price. Substitution was robust and significant for electronic cigarettes and Camel Snus. The ETM is a novel, practical assay that mimics the real-world marketplace, and functions as a simple research tool for both researchers and participants. Across the two experiments the product mix in the ETM altered which products functioned as substitutes suggesting complex interactions between purchasing and product availability. This article adds a novel method of collecting purchasing data that mimics real world purchasing to the existing literature. The ETM is a practical avenue by which to study both hypothetical and potentially real purchasing. © The Author

  5. Methodological principles for optimising functional MRI experiments; Methodische Grundlagen der Optimierung funktioneller MR-Experimente

    Energy Technology Data Exchange (ETDEWEB)

    Wuestenberg, T. [Georg-August-Universitaet Goettingen, Abteilung fuer Medizinische Psychologie (Germany); Georg-August-Universitaet, Abteilung fuer Medizinische Psychologie, Goettingen (Germany); Giesel, F.L. [Deutsches Kebsforschungszentrum (DKFZ) Heidelberg, Abteilung fuer Radiologische Diagnostik (Germany); Strasburger, H. [Georg-August-Universitaet Goettingen, Abteilung fuer Medizinische Psychologie (Germany)

    2005-02-01

    Functional magnetic resonance imaging (fMRI) is one of the most common methods for localising neuronal activity in the brain. Even though the sensitivity of fMRI is comparatively low, the optimisation of certain experimental parameters allows obtaining reliable results. In this article, approaches for optimising the experimental design, imaging parameters and analytic strategies will be discussed. Clinical neuroscientists and interested physicians will receive practical rules of thumb for improving the efficiency of brain imaging experiments. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) des Zentralnervensystems ist eine der meistgenutzten Methoden zur Lokalisierung neuronaler Aktivitaet im Gehirn. Obwohl die Sensitivitaet der fMRT vergleichsweise gering ist, kann durch die Auswahl geeigneter experimenteller Parameter die Empfindlichkeit dieses bildgebenden Verfahrens gesteigert und die Reliabilitaet der Ergebnisse gewaehrleistet werden. In diesem Artikel werden deshalb Ansaetze fuer die Optimierung des Paradigmendesigns, der MR-Bildgebung und der Datenauswertung diskutiert. Klinischen Forschern und interessierten Aerzten sollen dadurch Richtgroessen fuer die Durchfuehrung effektiver fMRT-Experimente vermittelt werden. (orig.)

  6. Imaging samples in silica aerogel using an experimental point spread function.

    Science.gov (United States)

    White, Amanda J; Ebel, Denton S

    2015-02-01

    Light microscopy is a powerful tool that allows for many types of samples to be examined in a rapid, easy, and nondestructive manner. Subsequent image analysis, however, is compromised by distortion of signal by instrument optics. Deconvolution of images prior to analysis allows for the recovery of lost information by procedures that utilize either a theoretically or experimentally calculated point spread function (PSF). Using a laser scanning confocal microscope (LSCM), we have imaged whole impact tracks of comet particles captured in silica aerogel, a low density, porous SiO2 solid, by the NASA Stardust mission. In order to understand the dynamical interactions between the particles and the aerogel, precise grain location and track volume measurement are required. We report a method for measuring an experimental PSF suitable for three-dimensional deconvolution of imaged particles in aerogel. Using fluorescent beads manufactured into Stardust flight-grade aerogel, we have applied a deconvolution technique standard in the biological sciences to confocal images of whole Stardust tracks. The incorporation of an experimentally measured PSF allows for better quantitative measurements of the size and location of single grains in aerogel and more accurate measurements of track morphology.

  7. In silico modeling and experimental evidence of coagulant protein interaction with precursors for nanoparticle functionalization.

    Science.gov (United States)

    Okoli, Chuka; Sengottaiyan, Selvaraj; Arul Murugan, N; Pavankumar, Asalapuram R; Agren, Hans; Kuttuva Rajarao, Gunaratna

    2013-10-01

    The design of novel protein-nanoparticle hybrid systems has applications in many fields of science ranging from biomedicine, catalysis, water treatment, etc. The main barrier in devising such tool is lack of adequate information or poor understanding of protein-ligand chemistry. Here, we establish a new strategy based on computational modeling for protein and precursor linkers that can decorate the nanoparticles. Moringa oleifera (MO2.1) seed protein that has coagulation and antimicrobial properties was used. Superparamagnetic nanoparticles (SPION) with precursor ligands were used for the protein-ligand interaction studies. The molecular docking studies reveal that there are two binding sites, one is located at the core binding site; tetraethoxysilane (TEOS) or 3-aminopropyl trimethoxysilane (APTES) binds to this site while the other one is located at the side chain residues where trisodium citrate (TSC) or Si60 binds to this site. The protein-ligand distance profile analysis explains the differences in functional activity of the decorated SPION. Experimentally, TSC-coated nanoparticles showed higher coagulation activity as compared to TEOS- and APTES-coated SPION. To our knowledge, this is the first report on in vitro experimental data, which endorses the computational modeling studies as a powerful tool to design novel precursors for functionalization of nanomaterials; and develop interface hybrid systems for various applications.

  8. Urban artificial light emission function determined experimentally using night sky images

    Science.gov (United States)

    Solano Lamphar, Héctor Antonio; Kocifaj, Miroslav

    2016-09-01

    To date, diverse approximations have been developed to interpret the radiance of a night sky due to light emissions from ground-based light sources. The radiant intensity distribution as a function of zenith angle is one of the most unknown properties because of the collective effects of all artificial, private and public lights. The emission function (EF) is, however, a key property in modeling the skyglow under arbitrary conditions, and thus it is equally required by modelers, light pollution researchers, and also experimentalists who are using specialized devices to study the diffuse light of a night sky. In this paper, we present the second generation of a dedicated measuring system intended for routine monitoring of a night sky in any region. The experimental technology we have developed is used to interpret clear sky radiance data recorded at a set of discrete distances from a town (or city) with the aim to infer the fraction of upwardly emitted light (F), that is a parameter scaling the bulk EF. The retrieval of the direct upward emissions has been improved by introducing a weighting factor that is used to eliminate imperfections of experimental data and thus to make the computation of F more stable when processing the radiance data taken at two adjacent measuring points. The field experiments made in three Mexican cities are analyzed and the differences found are discussed.

  9. Neuromorphological and wiring pattern alterations effects on brain function: a mixed experimental and computational approach.

    Directory of Open Access Journals (Sweden)

    Linus Manubens-Gil

    2015-04-01

    In addition, the study of fixed intact brains (by means of the state of the art CLARITY technique brings us closer to biologically and medically relevant situations, allowing not only to confirm whether the functional links in neuronal cultures are also present in vivo, but also enabling the introduction of functional information (like behavioral studies and functional imaging and another layer of structural alterations such as brain region morphology, neuronal density, and long-range connectivity. Taking together the experimental information from these systems we want to feed self-developed computational models that allow us to understand what are the fundamental characteristics of the observed connectivity patterns and the impact of each of the alterations on neuronal network function. These models will also provide a framework able to account for the emergent properties that bridge the gap between spontaneous electrical activity arousal/transmission and higher order information processing and memory storage capacities in the brain. As an additional part of the project we are now working on the application of the clearing, labeling and imaging protocols to human biopsy samples. Our aim is to obtain neuronal architecture and connectivity information from focal cortical dysplasia microcircuits using samples from intractable temporal lobe epilepsy patients that undergo deep-brain electrode recording diagnosis and posterior surgical extraction of the tissue. Our computational models can allow us to discern the contributions of the observed abnormalities to neuronal hyperactivity and epileptic seizure generation.

  10. [Functional models of movement disorders of basal ganglia origin and effects of functional neurosurgery].

    Science.gov (United States)

    Hashimoto, Takao

    2007-01-01

    The rate model regarding the development of movement disorders of basal ganglia origin suggests that hyperkinetic and hypokinetic disorders occur as a result of changes in the firing rates in the GPi and SNr, which in turn suppress thalamocortical output. Dopamine depletion in Parkinson's disease increases basal ganglia output, then decreases thalamocortical output, leading to bradykinesia. This model, however, cannot explain a lack of deterioration of parkinsonian signs following thalamic coagulation surgery. Instead of the rate model, the beta oscillation hypothesis has been proposed, explaining that synchronized oscillation in the beta frequency in the basal ganglia disturbs initiation of voluntary movement. We observed that effective high-frequency STN stimulation in parkinsonian monkeys was associated with increase in the firing rate and the pattern shift from irregular burst firing to regular high-frequency firing in the projecting sites. High-frequency neural activation by deep brain stimulation is supposed to cancel lower frequency oscillation including beta oscillation, leading to improvement of bradykinesia. Our observation supports the significance of the neural activity pattern, rather than the tonic activity level, in the development of movement disorders. The rate model cannot explain the improvement of ballismus and chorea by pallidotomy because pallidotomy increases the disinhibition of the thalamocortical projection, which should increase the movements. We observed repetitive bursts or pauses of neuronal firing of the globus pallidus synchronized to ballistic movements in patients with hemiballism or chorea, suggesting that phasic neuronal driving in the basal ganglia is important as their pathophysiology.

  11. Annulus fibrosus functional extrafibrillar and fibrous mechanical behaviour: experimental and computational characterisation.

    Science.gov (United States)

    Mengoni, Marlène; Kayode, Oluwasegun; Sikora, Sebastien N F; Zapata-Cornelio, Fernando Y; Gregory, Diane E; Wilcox, Ruth K

    2017-08-01

    The development of current surgical treatments for intervertebral disc damage could benefit from virtual environment accounting for population variations. For such models to be reliable, a relevant description of the mechanical properties of the different tissues and their role in the functional mechanics of the disc is of major importance. The aims of this work were first to assess the physiological hoop strain in the annulus fibrosus in fresh conditions ( n  = 5) in order to extract a functional behaviour of the extrafibrillar matrix; then to reverse-engineer the annulus fibrosus fibrillar behaviour ( n  = 6). This was achieved by performing both direct and global controlled calibration of material parameters, accounting for the whole process of experimental design and in silico model methodology. Direct-controlled models are specimen-specific models representing controlled experimental conditions that can be replicated and directly comparing measurements. Validation was performed on another six specimens and a sensitivity study was performed. Hoop strains were measured as 17 ± 3% after 10 min relaxation and 21 ± 4% after 20-25 min relaxation, with no significant difference between the two measurements. The extrafibrillar matrix functional moduli were measured as 1.5 ± 0.7 MPa. Fibre-related material parameters showed large variability, with a variance above 0.28. Direct-controlled calibration and validation provides confidence that the model development methodology can capture the measurable variation within the population of tested specimens.

  12. FUNCTIONAL-ASPECTS OF DEVELOPMENTAL TOXICITY OF POLYHALOGENATED AROMATIC-HYDROCARBONS IN EXPERIMENTAL-ANIMALS AND HUMAN INFANTS

    NARCIS (Netherlands)

    BROUWER, A; AHLBORG, UG; VANDENBERG, M; BIRNBAUM, LS; BOERSMA, ER; BOSVELD, B; DENISON, MS; GRAY, LE; HAGMAR, L; HOLENE, E; HUISMAN, M; JACOBSON, SW; JACOBSON, JL; KOOPMANESSEBOOM, C; KOPPE, JG; KULIG, BM; MORSE, DC; MUCKLE, G; PETERSON, RE; SAUER, PJJ; SEEGAL, RF; SMITSVANPROOIJE, AE; TOUWEN, BCL; WEISGLASKUPERUS, N; WINNEKE, G

    1995-01-01

    A scientific evaluation was made of functional aspects of developmental toxicity of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in experimental animals and in human infants. Persistent neurobehavioral, reproductive and

  13. Probing the Mutational Interplay between Primary and Promiscuous Protein Functions: A Computational-Experimental Approach

    Science.gov (United States)

    Garcia-Seisdedos, Hector; Ibarra-Molero, Beatriz; Sanchez-Ruiz, Jose M.

    2012-01-01

    Protein promiscuity is of considerable interest due its role in adaptive metabolic plasticity, its fundamental connection with molecular evolution and also because of its biotechnological applications. Current views on the relation between primary and promiscuous protein activities stem largely from laboratory evolution experiments aimed at increasing promiscuous activity levels. Here, on the other hand, we attempt to assess the main features of the simultaneous modulation of the primary and promiscuous functions during the course of natural evolution. The computational/experimental approach we propose for this task involves the following steps: a function-targeted, statistical coupling analysis of evolutionary data is used to determine a set of positions likely linked to the recruitment of a promiscuous activity for a new function; a combinatorial library of mutations on this set of positions is prepared and screened for both, the primary and the promiscuous activities; a partial-least-squares reconstruction of the full combinatorial space is carried out; finally, an approximation to the Pareto set of variants with optimal primary/promiscuous activities is derived. Application of the approach to the emergence of folding catalysis in thioredoxin scaffolds reveals an unanticipated scenario: diverse patterns of primary/promiscuous activity modulation are possible, including a moderate (but likely significant in a biological context) simultaneous enhancement of both activities. We show that this scenario can be most simply explained on the basis of the conformational diversity hypothesis, although alternative interpretations cannot be ruled out. Overall, the results reported may help clarify the mechanisms of the evolution of new functions. From a different viewpoint, the partial-least-squares-reconstruction/Pareto-set-prediction approach we have introduced provides the computational basis for an efficient directed-evolution protocol aimed at the simultaneous

  14. An experimental investigation of the functional hypothesis and evolutionary advantage of stone-tipped spears.

    Directory of Open Access Journals (Sweden)

    Jayne Wilkins

    Full Text Available Stone-tipped weapons were a significant innovation for Middle Pleistocene hominins. Hafted hunting technology represents the development of new cognitive and social learning mechanisms within the genus Homo, and may have provided a foraging advantage over simpler forms of hunting technology, such as a sharpened wooden spear. However, the nature of this foraging advantage has not been confirmed. Experimental studies and ethnographic reports provide conflicting results regarding the relative importance of the functional, economic, and social roles of hafted hunting technology. The controlled experiment reported here was designed to test the functional hypothesis for stone-tipped weapons using spears and ballistics gelatin. It differs from previous investigations of this type because it includes a quantitative analysis of wound track profiles and focuses specifically on hand-delivered spear technology. Our results do not support the hypothesis that tipped spears penetrate deeper than untipped spears. However, tipped spears create a significantly larger inner wound cavity that widens distally. This inner wound cavity is analogous to the permanent wound cavity in ballistics research, which is considered the key variable affecting the relative 'stopping power' or 'killing power' of a penetrating weapon. Tipped spears conferred a functional advantage to Middle Pleistocene hominins, potentially affecting the frequency and regularity of hunting success with important implications for human adaptation and life history.

  15. Augmented Reality in Neurosurgery: A Review of Current Concepts and Emerging Applications.

    Science.gov (United States)

    Guha, Daipayan; Alotaibi, Naif M; Nguyen, Nhu; Gupta, Shaurya; McFaul, Christopher; Yang, Victor X D

    2017-05-01

    Augmented reality (AR) superimposes computer-generated virtual objects onto the user's view of the real world. Among medical disciplines, neurosurgery has long been at the forefront of image-guided surgery, and it continues to push the frontiers of AR technology in the operating room. In this systematic review, we explore the history of AR in neurosurgery and examine the literature on current neurosurgical applications of AR. Significant challenges to surgical AR exist, including compounded sources of registration error, impaired depth perception, visual and tactile temporal asynchrony, and operator inattentional blindness. Nevertheless, the ability to accurately display multiple three-dimensional datasets congruently over the area where they are most useful, coupled with future advances in imaging, registration, display technology, and robotic actuation, portend a promising role for AR in the neurosurgical operating room.

  16. 100 Years of British military neurosurgery: on the shoulders of giants.

    Science.gov (United States)

    Roberts, S A G

    2015-01-01

    Death from head injuries has been a feature of conflicts throughout the world for centuries. The burden of mortality has been variously affected by the evolution in weaponry from war-hammers to explosive ordnance, the influence of armour on survivability and the changing likelihood of infection as a complicating factor. Surgery evolved from haphazard trephination to valiant, yet disjointed, neurosurgery by a variety of great historical surgeons until the Crimean War of 1853-1856. However, it was events initiated by the Great War of 1914-1918 that not only marked the development of modern neurosurgical techniques, but our approach to military surgery as a whole. Here the author describes how 100 years of conflict and the input and intertwining relationships between the 20th century's great neurosurgeons established neurosurgery in the United Kingdom and beyond.

  17. Stereotactic neurosurgery in the United Kingdom: the hundred years from Horsley to Hariz.

    Science.gov (United States)

    Pereira, Erlick A C; Green, Alexander L; Nandi, Dipankar; Aziz, Tipu Z

    2008-09-01

    The history of stereotactic neurosurgery in the United Kingdom of Great Britain and Northern Ireland is reviewed. Horsley and Clarke's primate stereotaxy at the turn of the 20th century and events surrounding it are described, including Mussen's development of a human version of the apparatus. Stereotactic surgery after the Second World War is reviewed, with an emphasis on the pioneering work of Gillingham, Hitchcock, Knight, and Watkins and the contributions from Bennett, Gleave, Hughes, Johnson, McKissock, McCaul, and Dutton after the influences of Dott, Cairns, and Jefferson. Forster's introduction of gamma knife radiosurgery is summarized, as is the application of computed tomography by Hounsfield and Ambrose. Contemporary contributions to the present day from Bartlett, Richardson, Miles, Thomas, Gill, Aziz, Hariz, and others are summarized. The current status of British stereotactic neurosurgery is discussed.

  18. Fit of a sum of exponential functions to experimental data points

    Science.gov (United States)

    Monjoie, F. S.; Garnir, H. P.

    1993-01-01

    Expfit is a program aimed at the analysis of light decay curves in beam-foil spectroscopy experiments. It fits, using the least-squares method, a sum of exponential functions to experimental data points. A new technique, based on statistical tests, has been implemented to find the best number of parameters so that in most cases the fit is fully automatized. However, the user may give the initial parameters and determine the number of parameters to be adjusted or let Expfit find the best number of needed parameters. Expfit can print a report presenting the results of the fit under tabular and graphical format. Thanks to its graphic interface, built following the Apple Macintosh human interface guidelines, the program is easy to use.

  19. The pelvic ileal reservoir: an experimental assessment of its function compared with that of normal rectum.

    Science.gov (United States)

    Cranley, B; McKelvey, S T

    1982-08-01

    The function of the 3-loop pelvic ileal reservoir as an alternative to total proctocolectomy and ileostomy is assessed experimentally in dogs and compared with normal rectum under identical conditions. No difference was found between the pelvic ileal reservoir and normal rectum in their ability to maintain continence. The efficiency of evacuation, however, is significantly better in normal rectum (P less than 0.01). Observations made over a prolonged period of time suggest that frequency of defecation, tenesmus and incomplete evacuation are persistent problems with an ileal reservoir. The results of the experiments concur with clinical findings that satisfactory continence may be achieved by using the ileal reservoir but that it does not possess the ability of normal rectum to evacuate completely. Hence the frequent need for self-catheterization.

  20. What happens inside a fuel cell? Developing an experimental functional map of fuel cell performance.

    Science.gov (United States)

    Brett, Daniel J L; Kucernak, Anthony R; Aguiar, Patricia; Atkins, Stephen C; Brandon, Nigel P; Clague, Ralph; Cohen, Lesley F; Hinds, Gareth; Kalyvas, Christos; Offer, Gregory J; Ladewig, Bradley; Maher, Robert; Marquis, Andrew; Shearing, Paul; Vasileiadis, Nikos; Vesovic, Velisa

    2010-09-10

    Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an 'experimental functional map' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models.

  1. Dietary sodium modulation of aldosterone activation and renal function during the progression of experimental heart failure.

    Science.gov (United States)

    Miller, Wayne L; Borgeson, Daniel D; Grantham, J Aaron; Luchner, Andreas; Redfield, Margaret M; Burnett, John C

    2015-02-01

    Aldosterone activation is central to the sodium–fluid retention that marks the progression of heart failure (HF). The actions of dietary sodium restriction, a mainstay in HF management, on cardiorenal and neuroendocrine adaptations during the progression of HF are poorly understood. The study aim was to assess the role of dietary sodium during the progression of experimental HF. Experimental HF was produced in a canine model by rapid right ventricular pacing which evolves from early mild HF to overt, severe HF. Dogs were fed one of three diets: (i) high sodium [250 mEq (5.8 g) per day, n =6]; (ii) standard sodium [58 mEq (1.3 g) per day, n =6]; and (iii) sodium restriction [11 mEq (0.25 g) per day, n =6]. During the 38-day study, haemodynamics, renal function, plasma renin activity (PRA), and aldosterone were measured. Changes in haemodynamics at 38 days were similar in all three groups, as were changes in renal function. Aldosterone activation was demonstrated in all three groups; however, dietary sodium restriction, in contrast to high sodium, resulted in early (10 days) activation of PRA and aldosterone. High sodium demonstrated significant suppression of aldosterone activation over the course of HF progression. Excessive dietary sodium restriction particularly in early stage HF results in early aldosterone activation, while normal and excess sodium intake are associated with delayed or suppressed activation. These findings warrant evaluation in humans to determine if dietary sodium manipulation, particularly during early stage HF, may have a significant impact on neuroendocrine disease progression.

  2. The impact of experimental sleep restriction on affective functioning in social and nonsocial contexts among adolescents.

    Science.gov (United States)

    McMakin, Dana L; Dahl, Ronald E; Buysse, Daniel J; Cousins, Jennifer C; Forbes, Erika E; Silk, Jennifer S; Siegle, Greg J; Franzen, Peter L

    2016-09-01

    Short sleep duration is highly prevalent in adolescence, and it prospectively predicts problems with emotional adjustment and psychiatric health. To move beyond epidemiological associations and inform models of developmental psychopathology, we experimentally restricted sleep to observe impacts on affective functioning. Based on the importance of social contexts to adolescent emotional experiences, we also examined the impact of restricted sleep on socioaffective functioning in an ecologically valid peer interaction task. In Study 1, adolescents (ages 11.5-15.0, n = 48) were randomly assigned to two nights of polysomnography-monitored sleep restriction (4 hr in bed) or extension (10 hr in bed). One week later, they completed the other sleep manipulation. Affective functioning was assessed by self-report and pupil response to standardized affective sounds. Study 2 used a similar protocol and invited adolescents (ages 12-15.0, n = 16) to the sleep laboratory along with 2-4 friends to observe affective behavior in a social context primed for peer conflict. Mixed effects models were used to evaluate the effect of sleep condition on affective outcomes. Study 1 demonstrated increased negative affect following sleep restriction, relative to extension, on self-report (p = .02) and pupil measures (p = .01). Study 2 replicated these effects (both p = .04) and demonstrated greater negative affective behavior in a peer social context (p = .01). Exploratory analyses for positive affect showed reductions as assessed by self-report (p = .005), but not pupil (p = .81), in Study 1; and no significant effects in Study 2 (self-report, p = .14; pupil, p = .29; positive affective behavior, p = .43). Experimental sleep restriction in adolescence impacts negative affective functioning as evidenced by self-report and pupil reactivity, as well as observed behavior in a social context primed for peer conflict. Implications for the impact of short sleep on

  3. Neurosurgery in the realm of 10(-9), part 1: stardust and nanotechnology in neuroscience.

    Science.gov (United States)

    Elder, James B; Liu, Charles Y; Apuzzo, Michael L J

    2008-01-01

    Nanotechnology as a science has evolved from notions and speculation to emerge as a prominent combination of science and engineering that stands to impact innumerable aspects of technology. Medicine in general and neurosurgery in particular will benefit greatly in terms of improved diagnostic and therapeutic capabilities. The recent explosion in nanotechnology products, including diverse applications such as beauty products and medical contrast agents, has been accompanied by an ever increasing volume of literature. Recent articles from our institution provided an historical and scientific background of nanotechnology, with a purposeful focus on nanomedicine. Future applications of nanotechnology to neuroscience and neurosurgery were briefly addressed. The present article is the first of two that will further this discussion by providing specific details of current nanotechnology applications and research related to neuroscience and clinical neurosurgery. This article also provides relevant perspective in scale, history, economics, and toxicology. Topics of specific importance to developments or advances of technologies used by neuroscientists and neurosurgeons are presented. In addition, advances in the field of microelectromechanical systems technology are discussed. Although larger than nanoscale, microelectromechanical systems technologies will play an important role in the future of medicine and neurosurgery. The second article will discuss current nanotechnologies that are being, or will be in the near future, incorporated into the armamentarium of the neurosurgeon. The goal of these articles is to keep the neuroscience community abreast of current developments in nanotechnology, nanomedicine, and, in particular, nanoneurosurgery, and to present possibilities for future applications of nanotechnology. As applications of nanotechnology permeate all forms of scientific and medical research, clinical applications will continue to emerge. Physicians of the

  4. Assessing residents' operative skills for external ventricular drain placement and shunt surgery in pediatric neurosurgery.

    Science.gov (United States)

    Aldave, Guillermo; Hansen, Daniel; Briceño, Valentina; Luerssen, Thomas G; Jea, Andrew

    2017-04-01

    OBJECTIVE The authors previously demonstrated the use of a validated Objective Structured Assessment of Technical Skills (OSATS) tool for evaluating residents' operative skills in pediatric neurosurgery. However, no benchmarks have been established for specific pediatric procedures despite an increased need for meaningful assessments that can either allow for early intervention for underperforming trainees or allow for proficient residents to progress to conducting operations independently with more passive supervision. This validated methodology and tool for assessment of operative skills for common pediatric neurosurgical procedures-external ventricular drain (EVD) placement and shunt surgery- was applied to establish its procedure-based feasibility and reliability, and to document the effect of repetition on achieving surgical skill proficiency in pediatric EVD placement and shunt surgery. METHODS A procedure-based technical skills assessment for EVD placements and shunt surgeries in pediatric neurosurgery was established through the use of task analysis. The authors enrolled all residents from 3 training programs (Baylor College of Medicine, Houston Methodist Hospital, and University of Texas-Medical Branch) who rotated through pediatric neurosurgery at Texas Children's Hospital over a 26-month period. For each EVD placement or shunt procedure performed with a resident, the faculty and resident (for self-assessment) completed an evaluation form (OSATS) based on a 5-point Likert scale with 7 categories. Data forms were then grouped according to faculty versus resident (self) assessment, length of pediatric neurosurgery rotation, postgraduate year level, and date of evaluation ("beginning of rotation," within 1 month of start date; "end of rotation," within 1 month of completion date; or "middle of rotation"). Descriptive statistical analyses were performed with the commercially available SPSS statistical software package. A p value pediatric procedures. The

  5. Virtual reality training in neurosurgery: Review of current status and future applications

    Science.gov (United States)

    Alaraj, Ali; Lemole, Michael G.; Finkle, Joshua H.; Yudkowsky, Rachel; Wallace, Adam; Luciano, Cristian; Banerjee, P. Pat; Rizzi, Silvio H.; Charbel, Fady T.

    2011-01-01

    Background: Over years, surgical training is changing and years of tradition are being challenged by legal and ethical concerns for patient safety, work hour restrictions, and the cost of operating room time. Surgical simulation and skill training offer an opportunity to teach and practice advanced techniques before attempting them on patients. Simulation training can be as straightforward as using real instruments and video equipment to manipulate simulated “tissue” in a box trainer. More advanced virtual reality (VR) simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations. Methods: A PubMed review of the literature was performed for the MESH words “Virtual reality, “Augmented Reality”, “Simulation”, “Training”, and “Neurosurgery”. Relevant articles were retrieved and reviewed. A review of the literature was performed for the history, current status of VR simulation in neurosurgery. Results: Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and credential surgeons as technically competent. The number of published literature discussing the application of VR simulation in neurosurgery training has evolved over the last decade from data visualization, including stereoscopic evaluation to more complex augmented reality models. With the revolution of computational analysis abilities, fully immersive VR models are currently available in neurosurgery training. Ventriculostomy catheters insertion, endoscopic and endovascular simulations are used in neurosurgical residency training centers across the world. Recent studies have shown the coloration of proficiency with those simulators and levels of experience in the real world. Conclusion: Fully immersive technology is starting to be applied to the practice of

  6. Diabetes insipidus following neurosurgery at a university hospital in Western Saudi Arabia.

    Science.gov (United States)

    Qari, Faiza A; AbuDaood, Elaff A; Nasser, Tariq A

    2016-02-01

    To review the incidence, spectrum of clinical manifestation, course, risk factors, as well as treatment of diabetes insipidus (DI) following neurosurgery of the pituitary gland. The files of 24 patients that underwent neurosurgery for sellar lesions, or tumor near the hypothalamus or pituitary gland at the Department of Neurosurgery, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia were retrospectively reviewed between January 2011 to December 2014. A total of 24 patients were studied, and were divided into 2 groups namely; DI and non-DI. Patient characteristics were studied using descriptive statistics. The differences in proportion between the 2 groups were found out using Z-test for proportion in 2 populations. The mean differences in the hormonal abnormalities for the 2 groups were assessed using independent t-test. All statistics are considered statistically significant when p less than 0.05. During hospitalization, 13 (54.2%) out of 24 patient that underwent neurosurgery had manifestations of DI, which was transient in 5 (38.8%) and permanent in 8 (61.2%). The DI subgroup contained higher prevalence of prolactinoma, craniopharyngioma, pre-operative panhypopituitarism, and macroadenoma in MRI imaging and transphenoidal surgery. Furthermore, urine osmolality was significantly lower in the DI group post-operatively with a significant p=0.023. It was recognized that the permanent DI documented more significant numbers than other studies. In our study group, it was recognized that permanent DI meant that our patients needed desmopressin for more than 3 months, which documented a more significant number than other studies.

  7. Quantifying workspace and forces of surgical dissection during robot-assisted neurosurgery.

    Science.gov (United States)

    Maddahi, Yaser; Gan, Liu Shi; Zareinia, Kourosh; Lama, Sanju; Sepehri, Nariman; Sutherland, Garnette R

    2016-09-01

    A prerequisite for successful robot-assisted neurosurgery is to use a hand-controller matched with characteristics of real robotic microsurgery. This study reports quantified data pertaining to the required workspace and exerted forces of surgical tools during robot-assisted microsurgery. A surgeon conducted four operations in which the neuroArm surgical system, an image-guided computer-assisted manipulator specifically designed to perform robot-assisted neurosurgery, was employed to surgically remove brain tumors. The position, orientation, and exerted force of surgical tools were measured during operations. Workspace of the neuroArm manipulators, for the cases studied, was 60×60×60 mm(3) while it offered orientation ranges of 103°, 62° and 112°. The surgical tools exerted a maximum force of 1.86 N with frequency band of less than 20 Hz. This data provides important information specific to neurosurgery that can be used to select among commercially available, or further design a customized, haptic hand-controller for robot-assisted neurosurgical systems. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Laser neurosurgery: A systematic analysis of magnetic resonance-guided laser interstitial thermal therapies.

    Science.gov (United States)

    Lagman, Carlito; Chung, Lawrance K; Pelargos, Panayiotis E; Ung, Nolan; Bui, Timothy T; Lee, Seung J; Voth, Brittany L; Yang, Isaac

    2017-02-01

    Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a novel minimally invasive modality that uses heat from laser probes to destroy tissue. Advances in probe design, cooling mechanisms, and real-time MR thermography have increased laser utilization in neurosurgery. The authors perform a systematic analysis of two commercially available MRgLITT systems used in neurosurgery: the Visualase® thermal therapy and NeuroBlate® Systems. Data extraction was performed in a blinded fashion. Twenty-two articles were included in the quantitative synthesis. A total of 223 patients were identified with the majority having undergone treatment with Visualase (n=154, 69%). Epilepsy was the most common indication for Visualase therapy (n=8 studies, 47%). Brain mass was the most common indication for NeuroBlate therapy (n=3 studies, 60%). There were no significant differences, except in age, wherein the NeuroBlate group was nearly twice as old as the Visualase group (plength-of-stay (LOS) were non-significant when adjusted for age and number of patients. Laser neurosurgery has evolved over recent decades. Clinical indications are currently being defined and will continue to emerge as laser technologies become more sophisticated. Head-to-head comparison of these systems was difficult given the variance in indications (and therefore patient population) and disparate literature. Copyright © 2016. Published by Elsevier Ltd.

  9. Candida infection of the central nervous system following neurosurgery: a 12-year review.

    LENUS (Irish Health Repository)

    O'Brien, Deirdre

    2012-02-01

    BACKGROUND: Candida infection of the central nervous system (CNS) following neurosurgery is relatively unusual but is associated with significant morbidity and mortality. We present our experience with this infection in adults and discuss clinical characteristics, treatment options, and outcome. METHODS: All episodes of Candida isolated from the central nervous system were identified by searching our laboratory database. Review of the cases was performed by means of a retrospective chart review. RESULTS: Eleven episodes of Candida CSF infection following neurosurgery were identified over a 12-year period. Candida albicans was the predominant species isolated (n = 8, 73%). All infections were associated with foreign intracranial material, nine with external ventricular drains (82%), one with a ventriculoperitoneal shunt, one with a lumbar drain, and one with Gliadel wafers (1,3-bis [2-chloroethyl]-1-nitrosurea). Fluconazole or liposomal amphotericin B were the most common anti-fungal agents used. The mortality rate identified in our series was 27%. CONCLUSIONS: Candida infection following neurosurgery remains a relatively rare occurrence but one that causes significant mortality. These are complex infections, the management of which benefits from a close liaison between the clinical microbiologist and neurosurgeon. Prompt initiation of antifungal agents and removal of infected devices offers the best hope of a cure.

  10. Malnutrition and brain function: experimental studies using the phenomenon of cortical spreading depression.

    Science.gov (United States)

    Guedes, R C; Monteiro, J S; Teodósio, N R

    1996-12-01

    Depending on its intensity and duration, nutritional deficiency can disrupt the structure and function of the nervous system of humans and other mammals, with consequences more or less devastating for the whole organism, particularly in the early postnatal life, when body growth is very rapid and the need for proteins, calories and other nutrients is greatest. In this review, electrophysiological data are presented regarding the use of the phenomenon of cortical spreading depression (CSD) to study effects of malnutrition on the brain. Several conditions of clinical importance and that are known to alter brain function are shown also to influence CSD features in experimental animals. Some of these conditions, (e.g., pharmacological manipulation of neurotransmitter systems, dietary treatment with Lithium, acute hyperglycemia, hypothyroidism, aging and environmental stimulation) decrease CSD susceptibility, while other conditions increase it, as, for example, systemic reduction of extracellular chloride levels, deprivation of REM-sleep, acute hypoglycemia, treatment with diazepam, consumption of ethanol and malnutrition. Particular emphasis is laid on the effect of early environmental enrichment on CSD in normal and malnourished animals. Our results suggest that such effect is more evident in the malnourished brain, as compared to the well-nourished one. The data also show that malnutrition alters the brain responsivity to some CSD-facilitatory or inhibitory agents. The underlying mechanisms to explain the observed effects are discussed.

  11. Experimental removal and recovery of subtidal grazers highlights the importance of functional redundancy and temporal context.

    Directory of Open Access Journals (Sweden)

    Robin Elahi

    Full Text Available The extent to which different grazers are functionally redundant has strong implications for the maintenance of community structure and function. Grazing by red urchins (Strongylocentrotus franciscanus on temperate rocky reefs can initiate a switch from invertebrate or macroalgal dominance to an algal crust state, but can also cause increases in the density of molluscan mesograzers. In this study, we tested the hypothesis that red urchins and lined chitons (Tonicella spp. are redundant in the maintenance of available space, defined as encrusting algae and bare rock. In a factorial field experiment replicated at three sites, we reduced the densities of urchins and chitons on subtidal rock walls for nine months. The effects of grazers were interpreted in the context of natural temporal variation by monitoring the benthic community one year before, during, and after grazer removal. The removal of each grazer in isolation had no effect on the epilithic community, but the removal of both grazers caused an increase in sessile invertebrates. The increase was due primarily to clonal ascidians, which displayed a large (∼75% relative increase in response to the removal of both grazers. However, the observed non-additive responses to grazer removal were temporary and smaller than seasonal fluctuations. Our data demonstrate that urchins and chitons can be redundant in the maintenance of available space, and highlight the value of drawing conclusions from experimental manipulations within an extended temporal context.

  12. Connectivity, non-random extinction and ecosystem function in experimental metacommunities.

    Science.gov (United States)

    Staddon, Philip; Lindo, Zoë; Crittenden, Peter D; Gilbert, Francis; Gonzalez, Andrew

    2010-05-01

    The spatial insurance hypothesis indicates that connectivity is an important attribute of natural ecosystems that sustains both biodiversity and ecosystem function. We tested the hypothesis by measuring the impact of manipulating connectivity in experimental metacommunties of a natural and diverse microecosystem. Isolation led to the extinction of large-bodied apex predators, subsequently followed by increases in prey species abundance. This trophic cascade was associated with significantly altered carbon and nitrogen fluxes in fragmented treatments. The ecosystem impacts were characteristic of a function debt because they persisted for several generations after the initial loss of connectivity. Local extinctions and disruption of ecosystem processes were mitigated, and even reversed, by the presence of corridors in the connected metacommunities, although these beneficial effects were unexpectedly delayed. We hypothesized that corridors maintained grazer movement between fragments, which enhanced microbial activity, and decomposition in comparison to isolated fragments. Our results indicate that knowledge of habitat connectivity and spatial processes is essential to understand the magnitude and timing of ecosystem perturbation in fragmented landscapes.

  13. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids

    Energy Technology Data Exchange (ETDEWEB)

    Ploetz, Elizabeth A.; Karunaweera, Sadish; Smith, Paul E. [Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506 (United States)

    2015-01-28

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined.

  14. Lingo-1 inhibited by RNA interference promotes functional recovery of experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Wang, Chun-Juan; Qu, Chuan-Qiang; Zhang, Jie; Fu, Pei-Cai; Guo, Shou-Gang; Tang, Rong-Hua

    2014-12-01

    Lingo-1 is a negative regulator of myelination. Repairment of demyelinating diseases, such as multiple sclerosis (MS)/experimental autoimmune encephalomyelitis (EAE), requires activation of the myelination program. In this study, we observed the effect of RNA interference on Lingo-1 expression, and the impact of Lingo-1 suppression on functional recovery and myelination/remyelination in EAE mice. Lentiviral vectors encoding Lingo-1 short hairpin RNA (LV/Lingo-1-shRNA) were constructed to inhibit Lingo-1 expression. LV/Lingo-1-shRNA of different titers were transferred into myelin oligodendrocyte glycoprotein-induced EAE mice by intracerebroventricular (ICV) injection. Meanwhile, lentiviral vectors carrying nonsense gene sequence (LVCON053) were used as negative control. The Lingo-1 expression was detected and locomotor function was evaluated at different time points (on days 1,3,7,14,21, and 30 after ICV injection). Myelination was investigated by luxol fast blue (LFB) staining.LV/Lingo-1-shRNA administration via ICV injection could efficiently down-regulate the Lingo-1 mRNA and protein expression in EAE mice on days 7,14,21, and 30 (P RNA interference is, therefore, a promising approach for the treatment of demyelinating diseases, such as MS/EAE. © 2014 Wiley Periodicals, Inc.

  15. Capabilities of the WinLTP data acquisition program extending beyond basic LTP experimental functions.

    Science.gov (United States)

    Anderson, William W; Collingridge, Graham L

    2007-05-15

    WinLTP is a Windows data acquisition program designed for the investigation of long-term potentiation (LTP), long-term depression (LTD), and synaptic responses in general. The capabilities required for basic LTP and LTD experiments include alternating two-input extracellular pathway stimulation, LTP induction by single train, theta burst, and primed burst stimulation, and LTD induction by low frequency stimulation. WinLTP provides on-line analyses of synaptic waveforms including measurement of slope, peak amplitude, population-spike amplitude, average amplitude, area, rise time, decay time, duration, cell input resistance, and series resistance. WinLTP also has many advanced capabilities that extend beyond basic LTP experimental capabilities: (1) analysis of all the evoked synaptic potentials individually within a sweep, and the analysis of the entire train-evoked synaptic response as a single entity. (2) Multitasking can be used to run a Continuous Acquisition task (saving data to a gap-free Axon Binary File), while concurrently running the Stimulation/Acquisition Sweeps task. (3) Dynamic Protocol Scripting can be used to make more complicated protocols involving nested Loops (with counters), Delays, Sweeps (with various stimulations), and Run functions (which execute a block of functions). Protocol flow can be changed while the experiment is running. WinLTP runs on National Instruments M-Series and Molecular Devices Digidata 132x boards, and is available at www.winltp.com.

  16. Vitamin D(3 availability and functional activity of peripheral blood phagocytes in experimental type 1 diabetes

    Directory of Open Access Journals (Sweden)

    D. О. Labudzynskyi

    2014-04-01

    Full Text Available The study was devoted to identifying the relation between vitamin D3 availability (assessed by the level of circulatory 25OHD3, content of vitamin D3 25-hydroxylase isozymes CYP27A1 and CYP2R1 in hepatic tissue and functional activity of peripheral blood phagocytes in mice with experimental type 1 diabetes. It has been shown that diabetes is accompanied by the development of vitamin D3-deficiency which is characterized by decreased 25OHD3 content in blood serum and determined by changes in tissue expression of the major isoforms of vitamin D3 25-hydroxylase. The level of hepatic CYP27A1 was revealed to be markedly reduced with a concurrent significant augmentation of CYP2R1. Cholecalciferol administration resulted in normalization of tissue levels of both isoforms of vitamin D3 25-hydroxylase and blood serum 25OHD3 content. Diabetes-associated vitamin D3 deficiency correlated with a decrease in phagocytic activity of granulocytes and monocytes, and their ability to produce antibacterial biooxidants such as reactive oxygen and nitrogen forms. Vitamin D3 efficacy to attenuate these abnormalities of immune function was established, indicating an important immunoregulatory role of cholecalciferol in the phagocytic mechanism of antigens elimination implemented by granulocytes and monocytes.

  17. Modulation of Gut Microbiome Composition and Function in Experimental Colitis Treated with Sulfasalazine.

    Science.gov (United States)

    Zheng, Haihui; Chen, Mingyi; Li, Yuan; Wang, Yuanyuan; Wei, Lin; Liao, Ziqiong; Wang, Mengxia; Ma, Fangli; Liao, Qiongfeng; Xie, Zhiyong

    2017-01-01

    Inflammatory bowel disease (IBD) results from alterations in intestinal flora and the immune system. Sulfasalazine (SASP) is a sulfa antimicrobial used to treat IBD in clinic for years. However, how SASP affects gut microbes and its potential functions remains unclear. To investigate the relationships of SASP, IBD, and gut microbiome, we used 2,4,6-trinitrobenzenesulfonic acid (TNBS) to induce experimental colitis in rats, and analyzed the microbiota in the fecal samples, which come from the control group (treated with ethanol + saline), the model group (treated with TNBS-ethanol + saline) and the SASP group (treated with TNBS-ethanol + SASP), with 16S gene sequencing and followed up a subset sample using shotgun sequencing. The study found that SASP treatment could not only restore the TNBS-induced gut dysbiosis, which was proved by the increasing amount of SCFAs-producing bacteria and lactic acid-producing bacteria as well as the decreasing amount of Proteobacteria, but also modulate the dysregulated function of the TNBS-induced colitis to resemble that of the control group, including an increased capacity for basic metabolism (carbohydrate metabolism, citrate cycle) and a decrease in the oxidative stress (riboflavin, sulfur, cysteine) as well as bacterial pathogenesis (cell motility and secretion, bacterial motility proteins, flagellar assembly). Moreover, a higher proportion of Mycoplasma was observed in the SASP group, which may associate with infertility. In all, the study provides insight into specific microbial clades and pathways linked with SASP treatment to elaborate the mechanism for treatment of IBD.

  18. Comparison between skin-mounted fiducials and bone-implanted fiducials for image-guided neurosurgery

    Science.gov (United States)

    Rost, Jennifer; Harris, Steven S.; Stefansic, James D.; Sillay, Karl; Galloway, Robert L., Jr.

    2004-05-01

    Point-based registration for image-guided neurosurgery has become the industry standard. While the use of intrinsic points is appealing because of its retrospective nature, affixing extrinsic objects to the head prior to scanning has been demonstrated to provide much more accurate registrations. Points of reference between image space and physical space are called fiducials. The extrinsic objects which generate those points are fiducial markers. The markers can be broken down into two classifications: skin-mounted and bone-implanted. Each has distinct advantages and disadvantages. Skin-mounted fiducials require simply sticking them on the patient in locations suggested by the manufacturer, however, they can move with tractions placed on the skin, fall off and perhaps the most dangerous problem, they can be replaced by the patient. Bone implanted markers being rigidly affixed to the skull do not present such problems. However, a minor surgical intervention (analogous to dental work) must be performed to implant the markers prior to surgery. Therefore marker type and use has become a decision point for image-guided surgery. We have performed a series of experiments in an attempt to better quantify aspects of the two types of markers so that better informed decisions can be made. We have created a phantom composed of a full-size plastic skull [Wards Scientific Supply] with a 500 ml bag of saline placed in the brain cavity. The skull was then sealed. A skin mimicking material, DragonSkinTM [SmoothOn Company] was painted onto the surface and allowed to dry. Skin mounted fiducials [Medtronic-SNT] and bone-implanted markers [Z-Kat]were placed on the phantom. In addition, three additional bone-implanted markers were placed (two on the base of the skull and one in the eye socket for use as targets). The markers were imaged in CT and 4 MRI sequences (T1-weighted, T2 weighted, SPGR, and a functional series.) The markers were also located in physical space using an Optotrak

  19. Experimental validation of response function of a NaI (Tl) detector modeled with Monte Carlo codes

    Science.gov (United States)

    Hajheidari, M. T.; Safari, M. J.; Afarideh, H.; Rouhi, H.

    2016-06-01

    This paper reports on the simulation of the response function of a Ø3"× 3" NaI (Tl) detector, using the FLUKA and MCNPX codes. These models were validated against extensive experimental data and used to benchmark various aspects of the response function. Comparisons show good agreement between both codes and experiments for different geometrical arrangements and gamma-ray energies.

  20. Experimental deep brain stimulation in animal models.

    Science.gov (United States)

    Tan, Sonny Kh; Vlamings, Rinske; Lim, Leewei; Sesia, Thibault; Janssen, Marcus Lf; Steinbusch, Harry Wm; Visser-Vandewalle, Veerle; Temel, Yasin

    2010-10-01

    DEEP BRAIN STIMULATION (DBS) as a therapy in neurological and psychiatric disorders is widely applied in the field of functional and stereotactic neurosurgery. In this respect, experimental DBS in animal models is performed to evaluate new indications and new technology. In this article, we review our experience with the concept of experimental DBS, including its development and validation. An electrode construction was developed using clinical principles to perform DBS unilaterally or bilaterally in freely moving rats. The stimulation parameters were adjusted for the rat using current density calculations. We performed validation studies in 2 animal models: a rat model of Parkinson's disease (bilateral 6-hydroxydopamine infusion in the striatum) and a rat model of Huntington's disease (transgenic rats). The effects of DBS were evaluated in different behavioral tasks measuring motor and cognitive functions. The electrode construction developed allows experimental DBS to be performed in freely moving rats. With the current setup, electrodes are placed in the target in 70% to 95% of the cases. Using a rat model, we showed that bilateral DBS of the subthalamic nucleus improves parkinsonian motor disability, but can induce behavioral side effects, similar to the clinical situation. In addition, we showed that DBS of the globus pallidus can improve motor and cognitive symptoms in a rat model of Huntington's disease. Nevertheless, during the process of the development and validation of experimental DBS, we encountered specific problems. These are discussed in detail. Experimental DBS in freely moving animals is an adequate tool to explore new indications for DBS and to refine DBS technology.

  1. Effect of melatonin on the functional recovery from experimental traumatic compression of the spinal cord

    Directory of Open Access Journals (Sweden)

    A. Schiaveto-de-Souza

    2013-12-01

    Full Text Available Spinal cord injury is an extremely severe condition with no available effective therapies. We examined the effect of melatonin on traumatic compression of the spinal cord. Sixty male adult Wistar rats were divided into three groups: sham-operated animals and animals with 35 and 50% spinal cord compression with a polycarbonate rod spacer. Each group was divided into two subgroups, each receiving an injection of vehicle or melatonin (2.5 mg/kg, intraperitoneal 5 min prior to and 1, 2, 3, and 4 h after injury. Functional recovery was monitored weekly by the open-field test, the Basso, Beattie and Bresnahan locomotor scale and the inclined plane test. Histological changes of the spinal cord were examined 35 days after injury. Motor scores were progressively lower as spacer size increased according to the motor scale and inclined plane test evaluation at all times of assessment. The results of the two tests were correlated. The open-field test presented similar results with a less pronounced difference between the 35 and 50% compression groups. The injured groups presented functional recovery that was more evident in the first and second weeks. Animals receiving melatonin treatment presented more pronounced functional recovery than vehicle-treated animals as measured by the motor scale or inclined plane. NADPH-d histochemistry revealed integrity of the spinal cord thoracic segment in sham-operated animals and confirmed the severity of the lesion after spinal cord narrowing. The results obtained after experimental compression of the spinal cord support the hypothesis that melatonin may be considered for use in clinical practice because of its protective effect on the secondary wave of neuronal death following the primary wave after spinal cord injury.

  2. Desmopressin improves intestinal functional capillary density and decreases leukocyte activation in experimental endotoxemia.

    Science.gov (United States)

    Wafa, K; Lehmann, C; Wagner, L; Drzymulski, I; Wegner, A; Pavlovic, D

    2015-01-01

    Blood flow to the intestine is decreased in sepsis in favor of vital organs resulting in ischemic damage of the gut mucosa. Once the mucosa is damaged, increased translocation of intestinal bacteria to the systemic circulation may occur. This in turn aggravates the inflammatory response contributing to the development of multi-organ failure. Desmopressin is a synthetic analog of vasopressin, an anti-diuretic hormone which has been shown to induce vasodilation and is thought to be implicated in immunomodulation. In this study, we investigate the effects of desmopressin on the intestinal microcirculation during sepsis in an experimental endotoxemia model in rats using intravital microscopy. In addition, we investigate the effects of desmopressin on systemic inflammation. Forty Lewis rats were subdivided into four groups, where rats received intravenous saline (control), desmopressin (1μg/kg/ml), lipopolysaccharide (5mg/kg) or lipopolysaccharide followed by desmopressin. Inflammatory response was assessed by quantifying the number of temporary and firmly adherent leukocytes in submucosal venules. Capillary perfusion was determined by assessing the number of functional, non-functional and dysfunctional capillaries in the intestinal wall layers (muscularis longitudinalis, muscularis circularis and mucosa). Additionally, inflammatory cytokine levels were determined by multiplex assays. The number of firmly adhering leukocytes in V1 venules of rats receiving lipopolysaccharide and treated with desmopressin was significantly reduced compared to lipopolysaccharide only group (LPS: 259±25.7 vs. LPS+DDAVP: 203±17.2; n/mm(2); pdesmopressin treatment improved impaired intestinal microcirculation by improving functional capillary density following lipopolysaccharide administration in all examined layers of the intestinal wall. We also observed a significant decrease in TNF-α levels in rats which received desmopressin in endotoxemia compared to untreated rats (LPS: 383±64

  3. Effect of melatonin on the functional recovery from experimental traumatic compression of the spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Schiaveto-de-Souza, A. [Departamento de Morfofisiologia, Universidade Federal do Mato Grosso do Sul, Campo Grande, MS (Brazil); Silva, C.A. da [Departamento de Morfologia,Estomatologia e Fisiologia, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Defino, H.L.A. [Departamento de Orthopedia e Traumatologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Bel, E.A.Del [Departamento de Morfologia,Estomatologia e Fisiologia, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2013-04-12

    Spinal cord injury is an extremely severe condition with no available effective therapies. We examined the effect of melatonin on traumatic compression of the spinal cord. Sixty male adult Wistar rats were divided into three groups: sham-operated animals and animals with 35 and 50% spinal cord compression with a polycarbonate rod spacer. Each group was divided into two subgroups, each receiving an injection of vehicle or melatonin (2.5 mg/kg, intraperitoneal) 5 min prior to and 1, 2, 3, and 4 h after injury. Functional recovery was monitored weekly by the open-field test, the Basso, Beattie and Bresnahan locomotor scale and the inclined plane test. Histological changes of the spinal cord were examined 35 days after injury. Motor scores were progressively lower as spacer size increased according to the motor scale and inclined plane test evaluation at all times of assessment. The results of the two tests were correlated. The open-field test presented similar results with a less pronounced difference between the 35 and 50% compression groups. The injured groups presented functional recovery that was more evident in the first and second weeks. Animals receiving melatonin treatment presented more pronounced functional recovery than vehicle-treated animals as measured by the motor scale or inclined plane. NADPH-d histochemistry revealed integrity of the spinal cord thoracic segment in sham-operated animals and confirmed the severity of the lesion after spinal cord narrowing. The results obtained after experimental compression of the spinal cord support the hypothesis that melatonin may be considered for use in clinical practice because of its protective effect on the secondary wave of neuronal death following the primary wave after spinal cord injury.

  4. UV-Vis optoelectronic properties of α-SnWO4: A comparative experimental and density functional theory based study

    KAUST Repository

    Ziani, Ahmed

    2015-09-03

    We report a combined experimental and theoretical study on the optoelectronic properties of α-SnWO4 for UV-Vis excitation. The experimentally measured values for thin films were systematically compared with high-accuracy density functional theory and density functional perturbation theory using the HSE06 functional. The α-SnWO4 material shows an indirect bandgap of 1.52 eV with high absorption coefficient in the visible-light range (>2 × 105 cm−1). The results show relatively high dielectric constant (>30) and weak diffusion properties (large effective masses) of excited carriers.

  5. What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

    KAUST Repository

    Brett, Daniel J. L.

    2010-08-20

    Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an \\'experimental functional map\\' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models. © 2010 Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim.

  6. An experimental evaluation of self-interference in Narcissus assoanus: functional and evolutionary implications.

    Science.gov (United States)

    Cesaro, A C; Barrett, S C H; Maurice, S; Vaissiere, B E; Thompson, J D

    2004-11-01

    Floral traits that reduce self-pollination in hermaphroditic plants have usually been interpreted as mechanisms that limit the genetic consequences of self-fertilization. However, the avoidance of sexual conflict between female and male function (self-interference) may also represent an important selection pressure for the evolution of floral traits, particularly in self-incompatible species. Here, we use experimental manipulations to investigate self-interference in Narcissus assoanus, a self-incompatible species with a stigma-height dimorphism in which the degree of spatial separation between sex organs (herkogamy) differs strikingly between the long- and short-styled morphs (hereafter L- and S-morphs). We predicted that weak herkogamy in the L-morph would cause greater self-pollination and hence self-interference. Experimental self-pollination reduced seed set when it occurred prior to, or simultaneously with, cross-pollination in the L-morph, but only if it occurred prior to cross-pollination in the S-morph. In the field, autonomous self-pollination was greater in the L-morph than the S-morph, but we found no evidence that self-interference reduced maternal or paternal fitness in either morph. One-day-old flowers of the L-morph have reduced stigma receptivity and hence exhibit protandry, whereas stigma receptivity and anther dehiscence are concurrent in the S-morph. This suggests that the two style morphs have alternative strategies for reducing self-interference: dichogamy in the L-morph and herkogamy in the S-morph. These results provide insight into the mechanisms that reduce sexual conflict in hermaphrodite plants and are of significance for understanding the evolution and maintenance of sexual polymorphisms.

  7. Admissions for isolated nonoperative mild head injuries: Sharing the burden among trauma surgery, neurosurgery, and neurology.

    Science.gov (United States)

    Zhao, Ting; Mejaddam, Ali Y; Chang, Yuchiao; DeMoya, Marc A; King, David R; Yeh, Daniel D; Kaafarani, Haytham M A; Alam, Hasan B; Velmahos, George C

    2016-10-01

    Isolated nonoperative mild head injuries (INOMHI) occur with increasing frequency in an aging population. These patients often have multiple social, discharge, and rehabilitation issues, which far exceed the acute component of their care. This study was aimed to compare the outcomes of patients with INOMHI admitted to three services: trauma surgery, neurosurgery, and neurology. Retrospective case series (January 1, 2009 to August 31, 2013) at an academic Level I trauma center. According to an institutional protocol, INOMHI patients with Glasgow Coma Scale (GCS) of 13 to 15 were admitted on a weekly rotational basis to trauma surgery, neurosurgery, and neurology. The three populations were compared, and the primary outcomes were survival rate to discharge, neurological status at hospital discharge as measured by the Glasgow Outcome Score (GOS), and discharge disposition. Four hundred eighty-eight INOMHI patients were admitted (trauma surgery, 172; neurosurgery, 131; neurology, 185). The mean age of the study population was 65.3 years, and 58.8% of patients were male. Seventy-seven percent of patients has a GCS score of 15. Age, sex, mechanism of injury, Charlson Comorbidity Index, Injury Severity Score, Abbreviated Injury Scale in head and neck, and GCS were similar among the three groups. Patients who were admitted to trauma surgery, neurosurgery and neurology services had similar proportions of survivors (98.8% vs 95.7% vs 94.7%), and discharge disposition (home, 57.0% vs 61.6% vs 55.7%). The proportion of patients with GOS of 4 or 5 on discharge was slightly higher among patients admitted to trauma (97.7% vs 93.0% vs 92.4%). In a logistic regression model adjusting for Charlson Comorbidity Index CCI and Abbreviated Injury Scale head and neck scores, patients who were admitted to neurology or neurosurgery had significantly lower odds being discharged with GOS 4 or 5. While the trauma group had the lowest proportion of repeats of brain computed tomography (61

  8. CHANGING METABOLIC FUNCTIONS IN EXPERIMENTAL ANIMALS AFTER INTRODUCTION OF THE XENOBIOTIC, IMMUNOTROPIC DRUG AND PROBIOTIC

    Directory of Open Access Journals (Sweden)

    Zvyagintseva O.V.

    2015-05-01

    Full Text Available The aim of the study was to evaluate in vivo changes in metabolic and barrier function of the resistance factors (activity of enzymes of neutrophils, the efficiency of phagocytosis, some biochemical parameters (concentration of ceruloplasmin and haptoglobin and proliferate activity in vitro cells after introduction of copper sulfate, probiotics and immunostimulant "Fungidol" the experimental animals. Material and methods. The in vivo experiments were performed on 6-month-old male rats of Wistar line. Identified the following groups: group 1 - control animals, which were intraperitoneally injected with saline (n = 5; group 2 - animals that were administered saline per os and 48 hours a solution of copper sulphate intraperitoneally (n = 5; group 3 - animals, which were injected with immunotropic drug "Fungidol" per os and 48 hours a solution of copper sulphate intraperitoneally (n = 5; group 4 animals, which were injected with a solution of probiotics per os and 48 hours a solution of copper sulphate intraperitoneally (n = 5. As a probiotic used capsules firm Yogurt that contains active Lactobacillus acidophilus, Lactobacillus rhamnosus, Streptococcus thermophillus, Lactobacillus bulgaricus. The concentration of haptoglobin and ceruloplasmin were determined spectrophotometrically. Oxygen-dependent metabolism of neutrophils was investigated by microscopy according to their ability to absorb nitroblue tetrazolium (NBT-test and restore it to deformazione in the form of granules blue color under the influence of superoxide anion, which is formed in the NADP-oxidase reaction, initiating the process of stimulation of phagocytosis (NBT-test. To determine the barrier function of phagocytic cells by light microscopy to evaluate the activity of phagocytosis of neutrophilic granulocytes with subsequent determination of phagocytic index, phagocytic number and the index of completeness of phagocytosis. As a microbial agent used is a suspension culture of

  9. Experimental Analysis of Functional Variation within Protein Families: Receiver Domain Autodephosphorylation Kinetics.

    Science.gov (United States)

    Page, Stephani C; Immormino, Robert M; Miller, Thane H; Bourret, Robert B

    2016-09-15

    Plants and microorganisms use two-component signal transduction systems (TCSs) to mediate responses to environmental stimuli. TCSs mediate responses through phosphotransfer from a conserved histidine on a sensor kinase to a conserved aspartate on the receiver domain of a response regulator. Typically, signal termination occurs through dephosphorylation of the receiver domain, which can catalyze its own dephosphorylation. Despite strong structural conservation between receiver domains, reported autodephosphorylation rate constants (kdephos) span a millionfold range. Variable receiver domain active-site residues D + 2 and T + 2 (two amino acids C terminal to conserved phosphorylation site and Thr/Ser, respectively) influence kdephos values, but the extent and mechanism of influence are unclear. We used sequence analysis of a large database of naturally occurring receiver domains to design mutant receiver domains for experimental analysis of autodephosphorylation kinetics. When combined with previous analyses, kdephos values were obtained for CheY variants that contained D + 2/T + 2 pairs found in 54% of receiver domain sequences. Tested pairs of amino acids at D + 2/T + 2 generally had similar effects on kdephos in CheY, PhoBN, or Spo0F. Acid or amide residues at D + 2/T + 2 enhanced kdephos CheY variants altered at D + 2/T + 2 exhibited rate constants for autophosphorylation with phosphoramidates and autodephosphorylation that were inversely correlated, suggesting that D + 2/T + 2 residues interact with aspects of the ground or transition states that differ between the two reactions. kdephos of CheY variants altered at D + 2/T + 2 correlated significantly with kdephos of wild-type receiver domains containing the same D + 2/T + 2 pair. Additionally, particular D + 2/T + 2 pairs were enriched in different response regulator subfamilies, suggesting functional significance. One protein family, defined by a conserved domain, can include hundreds of thousands of known

  10. Quality control and assurance in functional near infrared spectroscopy (fNIRS) experimentation

    Energy Technology Data Exchange (ETDEWEB)

    Orihuela-Espina, F; Leff, D R; James, D R C; Darzi, A W [Division of Surgery, Oncology, Reproductive Biology and Anaesthetics (SORA), Imperial College, London (United Kingdom); Yang, G Z, E-mail: f.orihuela-espina@imperial.ac.u [Institute of Biomedical Engineering, Imperial College, London (United Kingdom)

    2010-07-07

    Functional near infrared spectroscopy (fNIRS) is a rapidly developing neuroimaging modality for exploring cortical brain behaviour. Despite recent advances, the quality of fNIRS experimentation may be compromised in several ways: firstly, by altering the optical properties of the tissues encountered in the path of light; secondly, through adulteration of the recovered biological signals (noise) and finally, by modulating neural activity. Currently, there is no systematic way to guide the researcher regarding these factors when planning fNIRS studies. Conclusions extracted from fNIRS data will only be robust if appropriate methodology and analysis in accordance with the research question under investigation are employed. In order to address these issues and facilitate the quality control process, a taxonomy of factors influencing fNIRS data have been established. For each factor, a detailed description is provided and previous solutions are reviewed. Finally, a series of evidence-based recommendations are made with the aim of improving consistency and quality of fNIRS research.

  11. Experimental Validation of Depth Cameras for the Parameterization of Functional Balance of Patients in Clinical Tests

    Directory of Open Access Journals (Sweden)

    Francisco-Ángel Moreno

    2017-02-01

    Full Text Available In clinical practice, patients’ balance can be assessed using standard scales. Two of the most validated clinical tests for measuring balance are the Timed Up and Go (TUG test and the MultiDirectional Reach Test (MDRT. Nowadays, inertial sensors (IS are employed for kinematic analysis of functional tests in the clinical setting, and have become an alternative to expensive, 3D optical motion capture systems. In daily clinical practice, however, IS-based setups are yet cumbersome and inconvenient to apply. Current depth cameras have the potential for such application, presenting many advantages as, for instance, being portable, low-cost and minimally-invasive. This paper aims at experimentally validating to what extent this technology can substitute IS for the parameterization and kinematic analysis of the TUG and the MDRT tests. Twenty healthy young adults were recruited as participants to perform five different balance tests while kinematic data from their movements were measured by both a depth camera and an inertial sensor placed on their trunk. The reliability of the camera’s measurements is examined through the Interclass Correlation Coefficient (ICC, whilst the Pearson Correlation Coefficient (r is computed to evaluate the correlation between both sensor’s measurements, revealing excellent reliability and strong correlations in most cases.

  12. Quantitative MRI predicts long-term structural and functional outcome after experimental traumatic brain injury.

    Science.gov (United States)

    Immonen, Riikka J; Kharatishvili, Irina; Gröhn, Heidi; Pitkänen, Asla; Gröhn, Olli H J

    2009-03-01

    In traumatic brain injury (TBI) the initial impact causes both immediate damage and also launches a cascade of slowly progressive secondary damage. The chronic outcome disabilities vary greatly and can occur several years later. The aim of this study was to find predictive factors for the long-term outcome using multiparametric, non-invasive magnetic resonance imaging (MRI) methodology and a clinically relevant rat model of fluid percussion induced TBI. Our results demonstrated that the multiparametric quantitative MRI (T(2), T(1rho), trace of the diffusion tensor D(av), the extent of hyperintense lesion and intracerebral hemorrhage) acquired during acute and sub acute phases 3 h, 3 days, 9 days and 23 days post-injury has potential to predict the functional and histopathological outcome 6 to 12 months later. The acute D(av) changes in the ipsilateral hippocampus correlated with the chronic spatial learning and memory impairment evaluated using the Morris water maze (phelp to predict the long-term outcome after experimental TBI.

  13. Physiology of cerebral venous blood flow: from experimental data in animals to normal function in humans.

    Science.gov (United States)

    Schaller, B

    2004-11-01

    In contrast to the cerebroarterial system, the cerebrovenous system is not well examined and only partly understood. The cerebrovenous system represents a complex three-dimensional structure that is often asymmetric and considerably represent more variable pattern than the arterial anatomy. Particular emphasis is devoted to the venous return to extracranial drainage routes. As the state-of-the-art-imaging methods are playing a greater role in visualizing the intracranial venous system at present, its clinically pertinent anatomy and physiology has gain increasing interest, even so only few data are available. For this reason, experimental research on specific biophysical (fluid dynamic, rheologic factors) and hemodynamic (venous pressure, cerebral venous blood flow) parameters of the cerebral venous system is more on the focus; especially as these parameters are different to the cerebral arterial system. Particular emphasis is devoted to the venous return to extracranial drainage routes. From the present point of view, it seems that the cerebrovenous system may be one of the most important factors that guarantee normal brain function. In the light of this increasing interest in the cerebral venous system, the authors have summarized the current knowledge of the physiology of the cerebrovenous system and discuss it is in the light of its clinical relevance.

  14. Effects of Physical Activity on Children’s Executive Function: Contributions of Experimental Research on Aerobic Exercise

    Science.gov (United States)

    Best, John R.

    2011-01-01

    Executive function refers to the cognitive processes necessary for goal-directed cognition and behavior, which develop across childhood and adolescence. Recent experimental research indicates that both acute and chronic aerobic exercise promote children’s executive function. Furthermore, there is tentative evidence that not all forms of aerobic exercise benefit executive function equally: Cognitively-engaging exercise appears to have a stronger effect than non-engaging exercise on children’s executive function. This review discusses this evidence as well as the mechanisms that may underlie the association between exercise and executive function. Research from a variety of disciplines is covered, including developmental psychology, kinesiology, cognitive neuroscience, and biopsychology. Finally, these experimental findings are placed within the larger context of known links between action and cognition in infancy and early childhood, and the clinical and practical implications of this research are discussed. PMID:21818169

  15. The application of quality control circle in neurosurgery ICU nurses in raising compliance of the head of a bed

    Directory of Open Access Journals (Sweden)

    Na LI

    2014-11-01

    Full Text Available Objective: To explore the application of quality control circle in raising compliance of the head of a bed in neurosurgery ICU nurses. Methods: The quality control circle was made up of 4 ICU nurses, determine the subject in order to improve the neurosurgery ICU nurses in raising compliance of the head of a bed, according to the QCC activity steps to formulate plans, including grasp the current situation, goal setting, through analysis, circle members develop strategy and plan implementation and review, finally compared the situation before and after neurosurgery ICU nurses raised bed activities compliance. Results: After implementation of QCC, neurosurgery ICU nurses raised bed to 30 ~ 45 degrees. After activities, circle members in the team cooperation ability, cohesion, to accept new things ability, and innovative thinking ability and to raise the understanding of the relevant knowledge of the head of a bed has improved significantly. Conclusion: The application of quality management circle activity improves the neurosurgery ICU nurses effectively raise the compliance of the head of a bed, improve the comprehensive quality of the clinical nurses.

  16. Understanding brain, mind and soul: contributions from neurology and neurosurgery.

    Science.gov (United States)

    Pandya, Sunil K

    2011-01-01

    Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca's area or the movement of limbs to the contralateral motor cortex. Galen's localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units-neurones-lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of 'the cocktail of brain soup and spark' in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here.

  17. German Emergency Care in Neurosurgery and Military Neurology during World War II, 1939-1945.

    Science.gov (United States)

    Stahnisch, Frank W

    2016-01-01

    A critical analysis of the historical involvement of neurology and neurosurgery in military emergency care services enables us to better contextualize and appreciate the development of modern neurology at large. Wartime neurosurgery and civil brain science during the German Nazi period tightly coalesced in examining the specific injury types, which military neurosurgeons such as Wilhelm Toennis, Klaus Joachim Zuelch, and Georg Merrem encountered and treated based on their neurophysiological understanding gained from earlier peacetime research. Collaborative associations with Dr. Toennis in particular proved to be highly beneficial to other military neurologists and neurosurgeons during World War II and beyond. This article also discusses the prewar developments and considers the fate of German neurosurgeons and military neurologists after the war. The envisaged dynamic concepts of fast action, reaction, and recycling, which contemporary physicians had intensively studied in the preceding scientific experiments in their neurophysiological laboratories, had already been introduced into neurological surgery during the interwar period. In retrospect, World War II emergency rescue units greatly strengthened military operations through an active process of 'recycling' indispensable army personnel. Neurosurgical emergency chains thereby introduced another decisive step in the modernization of warfare, in that they increased the momentum of military mobility in the field. Notwithstanding the violence of warfare and the often inhumane ways in which such knowledge in the field of emergency neurology was gained, the protagonists among the group of experts in military neurology and neurosurgery strongly contributed to the postwar clinical neuroscience community in Germany. In differing political pretexts, this became visible in both East Germany and West Germany after the war, while the specific military and political conditions under which this knowledge of emergency medicine

  18. Preoperative Frailty Score for 30-Day Morbidity and Mortality After Cranial Neurosurgery.

    Science.gov (United States)

    Tomlinson, Samuel B; Piper, Keaton; Kimmell, Kristopher T; Vates, G Edward

    2017-11-01

    Evaluating preoperative frailty is critical for guiding shared surgical decision-making. The purpose of this study was to develop a novel preoperative frailty index for classification of adverse outcomes following cranial neurosurgery procedures. The American College of Surgeons National Surgical Quality Improvement Program database was queried for all cranial neurosurgery cases from 2006 to 2014. Sequential univariate and multivariate testing was used to identify significant independent predictors of 30-day mortality. Frailty scores were computed by summating across weighted predictors. Receiver operating characteristic curve analysis quantified the discriminative capacity of the frailty score for classifying mortality and other major adverse outcomes. List-wise exclusion of patients with incomplete datasets yielded a final sample of 27,098 patients (mortality rate = 3.9%). Multivariate regression testing identified 19 independent predictors of 30-day mortality. Receiver operating characteristic curve analysis revealed impressive outcome discrimination (area under the curve = 0.87, P mortality (15.4%) and major adverse outcomes (32.0%) compared with patients in the "low-risk" group (n = 21,943, mortality = 1.2%, major adverse outcomes = 4.0%). The frailty score remained highly discriminative across all age groups examined. Neurosurgical patients undergo extensive preoperative evaluation, but the field currently lacks a robust bedside scoring system for quantifying patient frailty. In this study, we introduced a novel preoperative frailty index capable of classifying 30-day morbidity and mortality outcomes following cranial neurosurgeries. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A novel augmented reality system of image projection for image-guided neurosurgery.

    Science.gov (United States)

    Mahvash, Mehran; Besharati Tabrizi, Leila

    2013-05-01

    Augmented reality systems combine virtual images with a real environment. To design and develop an augmented reality system for image-guided surgery of brain tumors using image projection. A virtual image was created in two ways: (1) MRI-based 3D model of the head matched with the segmented lesion of a patient using MRIcro software (version 1.4, freeware, Chris Rorden) and (2) Digital photograph based model in which the tumor region was drawn using image-editing software. The real environment was simulated with a head phantom. For direct projection of the virtual image to the head phantom, a commercially available video projector (PicoPix 1020, Philips) was used. The position and size of the virtual image was adjusted manually for registration, which was performed using anatomical landmarks and fiducial markers position. An augmented reality system for image-guided neurosurgery using direct image projection has been designed successfully and implemented in first evaluation with promising results. The virtual image could be projected to the head phantom and was registered manually. Accurate registration (mean projection error: 0.3 mm) was performed using anatomical landmarks and fiducial markers position. The direct projection of a virtual image to the patients head, skull, or brain surface in real time is an augmented reality system that can be used for image-guided neurosurgery. In this paper, the first evaluation of the system is presented. The encouraging first visualization results indicate that the presented augmented reality system might be an important enhancement of image-guided neurosurgery.

  20. Fundamentals of neurosurgery: virtual reality tasks for training and evaluation of technical skills.

    Science.gov (United States)

    Choudhury, Nusrat; Gélinas-Phaneuf, Nicholas; Delorme, Sébastien; Del Maestro, Rolando

    2013-11-01

    Technical skills training in neurosurgery is mostly done in the operating room. New educational paradigms are encouraging the development of novel training methods for surgical skills. Simulation could answer some of these needs. This article presents the development of a conceptual training framework for use on a virtual reality neurosurgical simulator. Appropriate tasks were identified by reviewing neurosurgical oncology curricula requirements and performing cognitive task analyses of basic techniques and representative surgeries. The tasks were then elaborated into training modules by including learning objectives, instructions, levels of difficulty, and performance metrics. Surveys and interviews were iteratively conducted with subject matter experts to delimitate, review, discuss, and approve each of the development stages. Five tasks were selected as representative of basic and advanced neurosurgical skill. These tasks were: 1) ventriculostomy, 2) endoscopic nasal navigation, 3) tumor debulking, 4) hemostasis, and 5) microdissection. The complete training modules were structured into easy, intermediate, and advanced settings. Performance metrics were also integrated to provide feedback on outcome, efficiency, and errors. The subject matter experts deemed the proposed modules as pertinent and useful for neurosurgical skills training. The conceptual framework presented here, the Fundamentals of Neurosurgery, represents a first attempt to develop standardized training modules for technical skills acquisition in neurosurgical oncology. The National Research Council Canada is currently developing NeuroTouch, a virtual reality simulator for cranial microneurosurgery. The simulator presently includes the five Fundamentals of Neurosurgery modules at varying stages of completion. A first pilot study has shown that neurosurgical residents obtained higher performance scores on the simulator than medical students. Further work will validate its components and use in a

  1. Evidence-based clinical management and utilization of new technology in European neurosurgery.

    Science.gov (United States)

    Weber, Clemens; Jakola, Asgeir S; Gulati, Sasha; Nygaard, Oystein P; Solheim, Ole

    2013-04-01

    Evidence-based medicine (EBM) has become one of the pillars of modern patient care. However, neurosurgery has always been an experience-based and technology-driven discipline, and it remains unknown to which extent European neurosurgeons follow high-level evidence-based recommendations. We conducted a Web-based survey with a 15-item questionnaire about evidence-based clinical management and utilization of new technology among European neurosurgeons. Two different sum scores were calculated from the questions concerning clinical practice; evidence-based treatment score and new technology score. A high evidence-based treatment score means that more clinical conditions (i.e., study questions) were managed in compliance with the available highest levels of evidence from published clinical trials. A high new technology score reflects the use of a high number of modern tools in neurosurgical practice. A total of 239 neurosurgeons from 30 different European countries answered the questionnaire. There were large variations among European neurosurgeons in providing evidence-based care and in utilization of various modern tools. There were significant regional differences in evidence-based treatment scores and modern technology scores with higher scores in northern and western Europe. High-volume institutions were not associated with better evidence-based treatment scores, but had significantly higher new technology scores. There were significantly higher new technology scores at university hospitals and a trend towards higher evidence-based treatment scores compared to other hospitals. Clinical management in neurosurgery does not always comply with the best available evidence and there are large regional differences in clinical management and in utilization of various modern tools. The position of evidence-based medicine in European neurosurgery seems weak and this may be a threat to the quality of care.

  2. Innovation in Neurosurgery: Intellectual Property Strategy and Academia/Industrial Collaboration.

    Science.gov (United States)

    Murayama, Yuichi

    2016-09-15

    Neurosurgery has tremendous possibilities for development of innovative medical devices. However, most of the neurosurgical devices used in Japan are imported products. Promotion and development of domestic medical devices is highly encouraged and it is one of the pillars of Prime Minister Shinzo Abe's growth strategy of Japanese economy. Innovative "Made in Japan" medical devices can be developed by interdisciplinary collaboration between industries and academic institutions. Proper orientation of medical and engineering education, social and administrative awareness of the need of facilitating the medical devices creative process with corresponding regulatory changes, and appropriate medical and technological infrastructure establishment are needed for stimulating medical device innovation.

  3. Objective skill analysis and assessment in neurosurgery by using an ultra-miniaturized inertial measurement unit WB-3--pilot tests.

    Science.gov (United States)

    Lin, Z; Zecca, M; Sessa, S; Sasaki, T; Suzuki, T; Itoh, K; Iseki, H; Takanishi, A

    2009-01-01

    In recent years there has been an ever increasing amount of research and development of technologies and methods to improve the quality and the performance of advanced surgery. In several fields, such as laparoscopy, various training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess her/his skills. For neurosurgery, however, the extremely small movements and target operating space involved have prevented until now the development of similar methodologies and systems. In this paper we present the development of an ultra-miniaturized Inertial Measurement Unit (IMU) and its application for neurosurgery skill assessment in a simple pick and place scenario. This analysis is a preliminary yet fundamental step to realize a better training/evaluation system for neurosurgeons, and to objectively evaluate and understand how the neurosurgery is performed.

  4. Current Applications and Future Perspectives of the Use of 3D Printing in Anatomical Training and Neurosurgery.

    Science.gov (United States)

    Baskaran, Vivek; Štrkalj, Goran; Štrkalj, Mirjana; Di Ieva, Antonio

    2016-01-01

    3D printing is a form of rapid prototyping technology, which has led to innovative new applications in biomedicine. It facilitates the production of highly accurate three dimensional objects from substrate materials. The inherent accuracy and other properties of 3D printing have allowed it to have exciting applications in anatomy education and surgery, with the specialty of neurosurgery having benefited particularly well. This article presents the findings of a literature review of the Pubmed and Web of Science databases investigating the applications of 3D printing in anatomy and surgical education, and neurosurgery. A number of applications within these fields were found, with many significantly improving the quality of anatomy and surgical education, and the practice of neurosurgery. They also offered advantages over existing approaches and practices. It is envisaged that the number of useful applications will rise in the coming years, particularly as the costs of this technology decrease and its uptake rises.

  5. THE INFLUENCE OF EXPERIMENTAL MODEL OF SPRINT ON DEVELOPMENT OF MOTOR AND FUNCTIONAL ABILITIES OF YOUNG FOOTBALLERS

    Directory of Open Access Journals (Sweden)

    Niko Raičković

    2008-08-01

    Full Text Available At the sample of 34 examinees, Elementary school students at the age of 14 and 15, involved in the training process in football clubs in Podgorica,was applied the experimental model for improving of sprint.The goal was to determine influence of experimental model on development of motor and functional abilities of examinees. Instruments for measuring of motor abilities were consisted of Segmental Speed dimensions,Explosive and Repetitive Strength dimensions,and of variables:Absolute Value of Maximal Consumption of Oxygen (FAV MCO, Maximal Aerobic Power (FMARP, Vital Capacity (FVI CA and Puls in Stationary Position (FPUSP, for measuring of functional abilities. Canonical Discriminative Analisis was used for testing differences between inicial and final measuring of examinees at the end of experimental period. The results of examination point at statistically significant increase in Explosive and Repetitive Strength, at Absolute Values of Maximal Oxygen Consumption and Maximal Anaerobic Power.

  6. Risk factors for the incidence of delirium in cerebrovascular patients in a Neurosurgery Intensive Care Unit: A prospective study.

    Science.gov (United States)

    Wang, Jun; Ji, Yuanyuan; Wang, Ning; Chen, Wenjin; Bao, Yuehong; Qin, Qinpu; Xiao, Qian; Li, Shulan

    2018-01-01

    To explore the incidence of delirium in cerebrovascular patients admitted in our Neurosurgery Intensive Care Unit and analyse the risk factors leading to delirium. Delirium is one of the most common mental disorders in general hospitals, but the incidence of different kinds of diseases and studies varies. Cerebrovascular patients in our Neurosurgery Intensive Care Unit are high-risk groups for delirium; identifying risk factors for delirium and taking early interventions are crucial for patient prognosis. A prospective study. A convenience sampling method was used to collect data from 128 patients in the Neurosurgery Intensive Care Unit of Xuanwu Hospital, Capital Medical University, Beijing, China, between May 2016-January 2017. Researchers used Confusion Assessment Method for the Intensive Care Unit (Chinese version) to assess each patient's delirium statement twice a day at regular times. We also collected other independent data variables and followed up the short-term clinical outcomes daily. On the basis of Confusion Assessment Method for the Intensive Care Unit evaluation, patients were divided into a delirium group and a nondelirium group. The prevalence of delirium among the 128 patients was 42.2%. Multivariate analysis showed that severity of illness, fever, the use of physical restraints and sleep deprivation were independent predictors of delirium in cerebrovascular patients in the Neurosurgery Intensive Care Unit. Cerebrovascular patients in the Neurosurgery Intensive Care Unit with a critical condition, fever or use of physical restraints or experiencing sleep deprivation were more prone to delirium. Cerebrovascular patients in the Neurosurgery Intensive Care Unit showed a high incidence of delirium. There are many risk factors leading to delirium, some of which are independent predictors of intensive care delirium. Patients with delirium will suffer various adverse effects upon their short-term clinical outcomes. Therefore, nurses should pay close

  7. An analysis of tracking error in image-guided neurosurgery.

    Science.gov (United States)

    Gerard, Ian J; Collins, D Louis

    2015-10-01

    This study quantifies some of the technical and physical factors that contribute to error in image-guided interventions. Errors associated with tracking, tool calibration and registration between a physical object and its corresponding image were investigated and compared with theoretical descriptions of these errors. A precision milled linear testing apparatus was constructed to perform the measurements. The tracking error was shown to increase in linear fashion with distance normal to the camera, and the tracking error ranged between 0.15 and 0.6 mm. The tool calibration error increased as a function of distance from the camera and the reference tool (0.2-0.8 mm). The fiducial registration error was shown to improve when more points were used up until a plateau value was reached which corresponded to the total fiducial localization error ([Formula: see text]0.8 mm). The target registration error distributions followed a [Formula: see text] distribution with the largest error and variation around fiducial points. To minimize errors, tools should be calibrated as close as possible to the reference tool and camera, and tools should be used as close to the front edge of the camera throughout the intervention, with the camera pointed in the direction where accuracy is least needed during surgery.

  8. Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats

    Directory of Open Access Journals (Sweden)

    Olavo Biraghi Letaif

    2015-10-01

    Full Text Available OBJECTIVES:To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion.METHODS:In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day.RESULTS:The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers.CONCLUSIONS:Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury.

  9. An experimental framework to identify community functional components driving ecosystem processes and services delivery

    Czech Academy of Sciences Publication Activity Database

    Dias, A. T. C.; Berg, M. P.; de Bello, Francesco; Oosten, A. R. V.; Bílá, Karolína; Morreti, M.

    2013-01-01

    Roč. 101, č. 1 (2013), s. 29-37 ISSN 0022-0477 R&D Projects: GA ČR GAP505/12/1296 Institutional support: RVO:67985939 ; RVO:67179843 Keywords : CWM * ecosystem functioning * ecosystem processes * ecosystem services * functional divergence * functional diversity * functional evenness * functional richness * mass ratio hypothesis * Rao index Subject RIV: EH - Ecology, Behaviour; EF - Botanics (BU-J) Impact factor: 5.694, year: 2013

  10. The hypothalamus at the crossroads of psychopathology and neurosurgery.

    Science.gov (United States)

    Barbosa, Daniel A N; de Oliveira-Souza, Ricardo; Monte Santo, Felipe; de Oliveira Faria, Ana Carolina; Gorgulho, Alessandra A; De Salles, Antonio A F

    2017-09-01

    The neurosurgical endeavor to treat psychiatric patients may have been part of human history since its beginning. The modern era of psychosurgery can be traced to the heroic attempts of Gottlieb Burckhardt and Egas Moniz to alleviate mental symptoms through the ablation of restricted areas of the frontal lobes in patients with disabling psychiatric illnesses. Thanks to the adaptation of the stereotactic frame to human patients, the ablation of large volumes of brain tissue has been practically abandoned in favor of controlled interventions with discrete targets. Consonant with the role of the hypothalamus in the mediation of the most fundamental approach-avoidance behaviors, some hypothalamic nuclei and regions, in particular, have been selected as targets for the treatment of aggressiveness (posterior hypothalamus), pathological obesity (lateral or ventromedial nuclei), sexual deviations (ventromedial nucleus), and drug dependence (ventromedial nucleus). Some recent improvements in outcomes may have been due to the use of stereotactically guided deep brain stimulation and the change of therapeutic focus from categorical diagnoses (such as schizophrenia) to dimensional symptoms (such as aggressiveness), which are nonspecific in terms of formal diagnosis. However, agreement has never been reached on 2 related issues: 1) the choice of target, based on individual diagnoses; and 2) reliable prediction of outcomes related to individual targets. Despite the lingering controversies on such critical aspects, the experience of the past decades should pave the way for advances in the field. The current failure of pharmacological treatments in a considerable proportion of patients with chronic disabling mental disorders is reminiscent of the state of affairs that prevailed in the years before the early psychosurgical attempts. This article reviews the functional organization of the hypothalamus, the effects of ablation and stimulation of discrete hypothalamic regions, and the

  11. Experimental generation of two-index Bessel-Gauss beams by engineering their angular spectrum functions

    Science.gov (United States)

    Yao, Hainan; Wang, Fei; Cai, Yangjian

    2018-01-01

    Two-index Bessel beams (TIBBs) was introduced by Ornigotti and Aiello (2014) theoretically. In this paper, we propose a simple experimental scheme for generation of two-index Bessel-Gauss beams (TIBGBs), as an extension of the TIBBs. The scheme is based on manipulating the amplitude and phase in the Fourier plane with the use of a spatial light modulator and a spiral phase plate. Furthermore, we experimentally report the generation of the several examples of the TIBGBs based on the proposed optical system. The focusing properties of the TIBGB with indices p = 1 and l = 2 passing through a single lens are investigated both theoretically and experimentally. The experimental results agree well with theoretical predictions.

  12. The beginnings of neurosurgery in California during the pre-Cushing era: 1850-1900.

    Science.gov (United States)

    Keller, T M

    1998-11-01

    The end of the present millennium marks the centennial of Harvey Cushing's European study year, after the completion of his surgical residency under William Stewart Halsted at the Johns Hopkins Hospital and just before beginning his surgical practice in Baltimore, Maryland. The year 2000 marks the sesquicentennial of California's admission to the Union as the 31st state. This report documents a number of the events and achievements that occurred during this "pre-Cushing era" (1850-1900) that contributed to the ultimate development of neurological surgery in California. The historical milestones of the California gold rush, the completion of the Transcontinental Railroad across the Sierra Nevada Mountains, and the careers of early California physicians and educators, including those of Hugh Toland and Levi Cooper Lane, were instrumental in building a foundation for the modern discipline of neurosurgery in the Golden State. This foundation would serve as a cornerstone for surgeons trained by Harvey Cushing (including Howard Naffziger, Carl Rand, and Edward Towne) who would arrive in California early in the 20th century and would define the specialty of neurosurgery. The legacy left by these physicians enhances the celebration of the closure of the millennium.

  13. Preresidency Publication Number Does Not Predict Academic Career Placement in Neurosurgery.

    Science.gov (United States)

    Daniels, Marcus; Garzon-Muvdi, Tomas; Maxwell, Russell; Tamargo, Rafael J; Huang, Judy; Witham, Tim; Bettegowda, Chetan; Chaichana, Kaisorn L

    2017-05-01

    It is unclear if preresidency and/or residency research work impacts academic neurosurgery placement post residency. The goal of this study is to evaluate the impact that preresidency and residency research publication has on attaining academic faculty positions. Alumni information was collected from 65 of the 108 (60%) neurosurgery residency websites. Graduates from these programs between 2005 and 2015 (n = 949) were analyzed to determine factors associated with an academic career. Information on publications, citations, and H-index were obtained from Web of Science. Current position was designated as academic if the physician had a teaching position at a university hospital and private if the physician was not affiliated with a university hospital. Univariate and multivariate logistic regression models were used to identify factors associated with academic faculty positions post residency. Of the 949 physicians included in the analysis, 339 (36%) were in academic positions, 518 (55%) in private practice, and 92 (10%) were still in training. More than a fifth (212, or 22%) of physicians performed a research fellowship (8.2%) or attained a Ph.D. (14.1%) during medical school. Among those who had completed training, an academic career was associated with having 2 or more publications during residency (odds ratio [OR] [95% confidence interval, CI]: 3.87 [1.59-9.45]; P academic placement. These findings may help guide residency programs to identify and/or cultivate neurosurgeons to become academic neurosurgeons. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. da Vinci robot-assisted keyhole neurosurgery: a cadaver study on feasibility and safety.

    Science.gov (United States)

    Marcus, Hani J; Hughes-Hallett, Archie; Cundy, Thomas P; Yang, Guang-Zhong; Darzi, Ara; Nandi, Dipankar

    2015-04-01

    The goal of this cadaver study was to evaluate the feasibility and safety of da Vinci robot-assisted keyhole neurosurgery. Several keyhole craniotomies were fashioned including supraorbital subfrontal, retrosigmoid and supracerebellar infratentorial. In each case, a simple durotomy was performed, and the flap was retracted. The da Vinci surgical system was then used to perform arachnoid dissection towards the deep-seated intracranial cisterns. It was not possible to simultaneously pass the 12-mm endoscope and instruments through the keyhole craniotomy in any of the approaches performed, limiting visualization. The articulated instruments provided greater dexterity than existing tools, but the instrument arms could not be placed in parallel through the keyhole craniotomy and, therefore, could not be advanced to the deep cisterns without significant clashing. The da Vinci console offered considerable ergonomic advantages over the existing operating room arrangement, allowing the operating surgeon to remain non-sterile and seated comfortably throughout the procedure. However, the lack of haptic feedback was a notable limitation. In conclusion, while robotic platforms have the potential to greatly enhance the performance of transcranial approaches, there is strong justification for research into next-generation robots, better suited to keyhole neurosurgery.

  15. The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part II--concepts for future development, 2003 and beyond.

    Science.gov (United States)

    Liu, Charles Y; Spicer, Mark; Apuzzo, Michael L J

    2003-01-01

    The future development of the neurosurgical operative environment is driven principally by concurrent development in science and technology. In the new millennium, these developments are taking on a Jules Verne quality, with the ability to construct and manipulate the human organism and its surroundings at the level of atoms and molecules seemingly at hand. Thus, an examination of currents in technology advancement from the neurosurgical perspective can provide insight into the evolution of the neurosurgical operative environment. In the future, the optimal design solution for the operative environment requirements of specialized neurosurgery may take the form of composites of venues that are currently mutually distinct. Advances in microfabrication technology and laser optical manipulators are expanding the scope and role of robotics, with novel opportunities for bionic integration. Assimilation of biosensor technology into the operative environment promises to provide neurosurgeons of the future with a vastly expanded set of physiological data, which will require concurrent simplification and optimization of analysis and presentation schemes to facilitate practical usefulness. Nanotechnology derivatives are shattering the maximum limits of resolution and magnification allowed by conventional microscopes. Furthermore, quantum computing and molecular electronics promise to greatly enhance computational power, allowing the emerging reality of simulation and virtual neurosurgery for rehearsal and training purposes. Progressive minimalism is evident throughout, leading ultimately to a paradigm shift as the nanoscale is approached. At the interface between the old and new technological paradigms, issues related to integration may dictate the ultimate emergence of the products of the new paradigm. Once initiated, however, history suggests that the process of change will proceed rapidly and dramatically, with the ultimate neurosurgical operative environment of the future

  16. Cancelation of transducer effects from frequency response functions: Experimental case study on the steel plate

    Directory of Open Access Journals (Sweden)

    Pedram Zamani

    2016-04-01

    Full Text Available Modal analysis is a progressive science in the experimental evaluation of dynamic properties of the structures. Mechanical devices such as accelerometers are one of the sources of lack of quality in measuring modal testing parameters. In this article, elimination of the accelerometer’s mass effect of the frequency response of the structure is studied. So, a strategy is used for eliminating the mass effect using sensitivity analysis. In this method, the amount of mass change and the place to measure the structure’s response with least error in frequency correction is chosen. Experimental modal testing is carried out on a steel plate, and the effect of accelerometer’s mass is omitted using this strategy. Finally, a good agreement is achieved between numerical and experimental results.

  17. Differential Effects of Testosterone and Estradiol on Clitoral Function: An Experimental Study in Rats.

    Science.gov (United States)

    Comeglio, Paolo; Cellai, Ilaria; Filippi, Sandra; Corno, Chiara; Corcetto, Francesca; Morelli, Annamaria; Maneschi, Elena; Maseroli, Elisa; Mannucci, Edoardo; Fambrini, Massimiliano; Maggi, Mario; Vignozzi, Linda

    2016-12-01

    Female sexual response is a complex phenomenon in which psychological, neurologic, and vascular mechanisms and hormonal factors interact. During the arousal phase, they cooperate to increase genital blood flow, thus inducing engorgement of the clitoris and lubrication of the vagina. Regulation of vascular and non-vascular smooth muscle tone is the crucial event in the erectile process. Preclinical studies have suggested that nitric oxide (NO) is the main vasodilator neurotransmitter modulating, through the second messenger cyclic guanosine monophosphate (cGMP), clitoral flow vessels. To investigate the effects of sexual steroid hormones on pro-erectile and relaxant (mediated by NO and cGMP) and anti-erectile and contractile (mediated by ras homolog gene family member A [RhoA] and Rho-associated protein kinase [ROCK]) mechanisms in the clitoris using a validated animal model of female ovariectomized Sprague-Dawley rats. Subgroups of ovariectomized rats were treated with 17β-estradiol, progesterone, testosterone, or testosterone and letrozole for 6 weeks. The experimental groups were compared with a control group of intact rats. Sex steroids plasma levels were assessed and in vitro contractility studies were carried out in order to investigate the effect of ovariectomy and in vivo treatments on clitoris smooth muscle activity. Smooth muscle cells (SMCs) from rat clitoral biopsies were isolated and characterized. RhoA activity was determined in SMCs cell cultures. RNA from tissues and cells was analyzed by quantitative real-time RT-PCR. Using real-time polymerase chain reaction, testosterone treatment upregulated the expression of NO-mediated pathway genes (endothelial and neuronal NO synthase, guanylate cyclase soluble subunit-α3, guanylate cyclase soluble subunit-β3, cGMP-dependent protein kinase 1, and phosphodiesterase type 5). Conversely, estrogen replacement upregulated the expression of calcium-sensitizing RhoA-ROCK pathway genes. In vitro contractility

  18. Experimental models of testicular development and function using human tissue and cells

    DEFF Research Database (Denmark)

    Tharmalingam, Melissa D; Jorgensen, Anne; Mitchell, Rod T

    2018-01-01

    . In this review, we outline experimental approaches used to sustain cells and tissue from human testis at different developmental time-points and discuss relevant end-points. These include survival, proliferation and differentiation of cell lineages within the testis as well as autocrine, paracrine and endocrine...

  19. Establishing a generic training programme for future junior doctors: a role for neurosurgery within the framework of clinical neurosciences.

    Science.gov (United States)

    Nadarajah, Ramesh; Amin, Amit; Aldlyami, Ehabb; Kang, Niel; Wong, James Min-Leong; Selway, Richard; Gullan, Richard

    2005-01-01

    INTRODUCTION: To describe the opinion of junior doctors in neurosurgery in the UK and Eire about future reforms to training, and to relate this to the establishment of a generic neurosciences training programme. METHODS: A postal questionnaire survey of neurosurgery units in UK and Eire (36 units). All senior house officers (SHOs) taking part in a neurosurgery on-call rota during the 6 months between February and August 2003 (n=236); 190 respondents (response rate 81% overall, 90% neurosurgery SHOs and 55% neurology SHOs. The questionnaire covered most aspects of provision of training, working pattern and job satisfaction gained from the post. Also included were questions on future reforms for training. RESULTS: There is an overwhelming acceptance amongst SHOs for training to be centred on generic programmes. The audit also identified that there are many aspects of neurosurgical training which will be very suitable for trainees from other fields, thus supporting the establishment of a generic neurosciences training programme. CONCLUSIONS: The establishment of a generic training programme would encourage an improvement in training standards for the whole SHO grade. To ensure the success of this proposed generic training programme, support from junior doctors and all those involved in postgraduate education is required. Neurosciences teaching has the excellent potential to move towards the planning and formation of a generic neurosciences training programme in-line with the proposed reforms. PMID:16053687

  20. George Gershwin -- a case of new ways in neurosurgery as well as in the history of Western music.

    Science.gov (United States)

    Gasenzer, Elena; Neugebauer, Edmund A M

    2014-06-01

    George Gershwin, the famous American composer, died in 1937 of a temporal lobe glioma. An emergency surgery was performed by R. Nafziger and W. E. Dandy. The case of George Gershwin indicates the beginning of a new era in music history as well as in the history of neurosurgery.

  1. A Three-Dimensional Image Of The Cerebral Blood Vessels And Tumor For Use In Stereotactic Neurosurgery

    Science.gov (United States)

    Suetens, P.; Gybels, J.; Oosterlinck, A.; Haegemans, A.; Dierckx, P.

    1983-12-01

    A useful method that makes stereotactic neurosurgery safer, is developed. It yields an integrated stereoscopic image of the cerebral blood vessels, CT view of tumor and simulated electrode trajectory, allowing the surgeon to choose any electrode direction that looks convenient to him, without imminent danger of causing a haemorrhage.

  2. Preoperative imaging as the basis for image-guided neurosurgery. EN; Praeoperative Bildgebung. Grundlage der navigationsgestuetzten Neurochirurgie

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, D. (Klinik und Poliklinik fuer Neurochirurgie, Universitaet Leipzig; Klinik fuer Neurochirurgie, Universitaet Leipzig, Liebigstrasse 20, 04103, Leipzig); Strauss, G. (Klinik fuer HNO-Krankheiten, Universitaet Leipzig); Hesse, S.; Sabri, O. (Klinik fuer Nuklearmedizin, Universitaet Leipzig); Goldammer, A.; Meixensberger, J. (Klinik und Poliklinik fuer Neurochirurgie, Universitaet Leipzig); Hund-Georgiadis, M. (Max-Planck-Institut fuer Neuropsychologische Forschung, Leipzig); Richter, A.; Kahn, T. (Klinik fuer Diagnostische Radiologie, Universitaet Leipzig)

    2004-07-01

    With the progressive development of soft- and hardware, the acceptance of image-guided neurosurgery has increased dramatically. Additional image data are required to analyze the nature and the dimensions of pathological processes and the surrounding tissue. In this context, fMRI, SPECT, PET, as well as special modalities of CT and MR imaging, are routinely used. Secondary post-processing options are used to detect intracerebral lesions as well as adjacent functional eloquent regions in the parenchymatous organ pre- and intraoperatively. The integration of different image information guarantees the precise planning and realization of surgical maneuvers. The segmentation of interesting structures and risk structures, as well as their implementation in the neuronavigation systems, help to avoid additional intraoperative traumatization and offer a higher level of safety and precision. In this article the value and limitations of presurgical imaging will be discussed. (orig.) [German] Die bildgestuetzte Neurochirurgie erfaehrt mit der Entwicklung von Soft- und Hardware eine sprunghafte Akzeptanz. Zusaetzliche Bilddaten dienen der Beurteilung von Charakter und Ausdehnung von pathologischen Prozessen und dem Umgebungsgewebe. In diesem Kontext sind fMRT, SPECT, PET und spezielle Modalitaeten der CT- und MRT-Diagnostik zu nennen. Mittels sekundaerer Bildbearbeitung koennen intrazerebrale Laesionen und benachbarte, funktionell eloquente Regionen im parenchymatoesen Organ Gehirn prae- und intraoperativ detektiert werden. Die Integration verschiedener Bildinformationen garantiert eine praezise Planung und Realisierung von chirurgischen Manoevern. Die Segmentation interessierender Strukturen, von Risikostrukturen und deren Implementation in Systeme der Neuronavigation helfen, eine zusaetzliche intraoperative Traumatisierung zu vermeiden, und bieten eine groessere Sicherheit und Praezision. Mit diesem Artikel werden der Wert und die Grenzen praeoperativer Bilddiagnostik

  3. Altered contralateral sensorimotor system organization after experimental hemispherectomy: a structural and functional connectivity study

    Science.gov (United States)

    Otte, Willem M; van der Marel, Kajo; van Meer, Maurits P A; van Rijen, Peter C; Gosselaar, Peter H; Braun, Kees P J; Dijkhuizen, Rick M

    2015-01-01

    Hemispherectomy is often followed by remarkable recovery of cognitive and motor functions. This reflects plastic capacities of the remaining hemisphere, involving large-scale structural and functional adaptations. Better understanding of these adaptations may (1) provide new insights in the neuronal configuration and rewiring that underlies sensorimotor outcome restoration, and (2) guide development of rehabilitation strategies to enhance recovery after hemispheric lesioning. We assessed brain structure and function in a hemispherectomy model. With MRI we mapped changes in white matter structural integrity and gray matter functional connectivity in eight hemispherectomized rats, compared with 12 controls. Behavioral testing involved sensorimotor performance scoring. Diffusion tensor imaging and resting-state functional magnetic resonance imaging were acquired 7 and 49 days post surgery. Hemispherectomy caused significant sensorimotor deficits that largely recovered within 2 weeks. During the recovery period, fractional anisotropy was maintained and white matter volume and axial diffusivity increased in the contralateral cerebral peduncle, suggestive of preserved or improved white matter integrity despite overall reduced white matter volume. This was accompanied by functional adaptations in the contralateral sensorimotor network. The observed white matter modifications and reorganization of functional network regions may provide handles for rehabilitation strategies improving functional recovery following large lesions. PMID:25966942

  4. Experimental Study Using Functional Size Measurement in Building Estimation Models for Software Project Size

    NARCIS (Netherlands)

    Condori-Fernandez, Nelly; Daneva, Maia; Buglione, Luigi; Ormandjieva, Olga; Ormandjieva, O.; Constantinides, C.; Abran, A.; Lee, R.

    2010-01-01

    This paper reports on an experiment that investigates the predictability of software project size from software product size. The predictability research problem is analyzed at the stage of early requirements by accounting the size of functional requirements as well as the size of non-functional

  5. The first evaluation of brain shift during functional neurosurgery by deformation field analysis

    OpenAIRE

    Winkler, D; Tittgemeyer, M; Schwarz, J; Preul, C; Strecker, K; Meixensberger, J

    2005-01-01

    Stereotactic surgery is based on a high degree of accuracy in defining and localising intracranial targets and placing surgical tools. Brain shift can influence its accuracy significantly. Deep brain stimulation of the subthalamic nucleus can markedly change the quality of life of patients with advanced Parkinson's disease, but the outcome depends on the quality of electrode placement. A patient is reported in whom the placement of the second electrode was not successful. Deformation field an...

  6. The first evaluation of brain shift during functional neurosurgery by deformation field analysis.

    Science.gov (United States)

    Winkler, D; Tittgemeyer, M; Schwarz, J; Preul, C; Strecker, K; Meixensberger, J

    2005-08-01

    Stereotactic surgery is based on a high degree of accuracy in defining and localising intracranial targets and placing surgical tools. Brain shift can influence its accuracy significantly. Deep brain stimulation of the subthalamic nucleus can markedly change the quality of life of patients with advanced Parkinson's disease, but the outcome depends on the quality of electrode placement. A patient is reported in whom the placement of the second electrode was not successful. Deformation field analysis of pre- and postoperative three dimensional magnetic resonance images showed an intraoperative brain movement of 2 mm in the region of the subthalamic nucleus (the target point). Electrode repositioning resulted in efficient stimulation effects. This case report shows the need to reduce risk factors for intraoperative brain movement and demonstrates the ability of deformation field analysis to quantify this complication.

  7. Use of a formal assessment instrument for evaluation of resident operative skills in pediatric neurosurgery.

    Science.gov (United States)

    Hadley, Caroline; Lam, Sandi K; Briceño, Valentina; Luerssen, Thomas G; Jea, Andrew

    2015-08-28

    OBJECT Currently there is no standardized tool for assessment of neurosurgical resident performance in the operating room. In light of enhanced requirements issued by the Accreditation Council for Graduate Medical Education's Milestone Project and the Matrix Curriculum Project from the Society of Neurological Surgeons, the implementation of such a tool seems essential for objective evaluation of resident competence. Beyond compliance with governing body guidelines, objective assessment tools may be useful to direct early intervention for trainees performing below the level of their peers so that they may be given more hands-on teaching, while strong residents can be encouraged by faculty members to progress to conducting operations more independently with passive supervision. The aims of this study were to implement a validated assessment tool for evaluation of operative skills in pediatric neurosurgery and determine its feasibility and reliability. METHODS All neurosurgery residents completing their pediatric rotation over a 6-month period from January 1, 2014, to June 30, 2014, at the authors' institution were enrolled in this study. For each procedure, residents were evaluated by means of a form, with one copy being completed by the resident and a separate copy being completed by the attending surgeon. The evaluation form was based on the validated Objective Structured Assessment of Technical Skills for Surgery (OSATS) and used a 5-point Likert-type scale with 7 categories: respect for tissue; time and motion; instrument handling; knowledge of instruments; flow of operation; use of assistants; and knowledge of specific procedure. Data were then stratified by faculty versus resident (self-) assessment; postgraduate year level; and difficulty of procedure. Descriptive statistics (means and SDs) were calculated, and the results were compared using the Wilcoxon signed-rank test and Student t-test. A p value evaluations for 299 procedures, including 32

  8. Role of Inhibitors of Apoptosis Proteins in Testicular Function and Male Fertility: Effects of Polydeoxyribonucleotide Administration in Experimental Varicocele

    Directory of Open Access Journals (Sweden)

    Letteria Minutoli

    2015-01-01

    Full Text Available Neuronal apoptosis inhibitory protein (NAIP and survivin might play an important role in testicular function. We investigated the effect of PDRN, an agonist of adenosine A2A receptor, on testicular NAIP and survivin expression in an experimental model of varicocele. After the creation of experimental varicocele (28 days, adolescent male Sprague-Dawley rats were randomized to one of the following treatments lasting 21 days: vehicle, PDRN (8 mg/kg i.p., daily, PDRN + 3,7-dimethyl-propargylxanthine (DMPX, a specific adenosine A2A-receptor antagonist, 0.1 mg/kg i.p., daily, varicocelectomy, and varicocelectomy + PDRN (8 mg/kg i.p., daily. Sham-operated animals were used as controls. Animals were then euthanized and testis expression of NAIP and survivin was evaluated through qRT-PCR, western blot, and immunohistochemical analysis. Spermatogenetic activity was also assessed. NAIP and survivin expressions were significantly reduced following varicocele induction when compared to sham animals whereas PDRN-treated rats showed an increase in NAIP and survivin levels. Immunohistochemistry revealed an enhanced expression of NAIP and survivin with a characteristic pattern of cellular localization following PDRN treatment. Moreover, administration of PDRN significantly restored spermatogenic function in varicocele rats. PDRN may represent a rational therapeutic option for accelerating recovery from depressed testicular function through a strategic modulation of apoptosis in experimental varicocele.

  9. The Synthesis of Structural Responses Using Experimentally Measured Frequency Response Functions and Field Test Data

    Energy Technology Data Exchange (ETDEWEB)

    CAP,JEROME S.; NELSON,CURTIS F.

    2000-11-17

    This paper presents an analysis technique used to generate the structural response at locations not measured during the ejection of a captive-carried store. The ejection shock event is complicated by the fact that forces may be imparted to the store at eight distinct locations. The technique derives forcing functions by combining the initial field test data for a limited number of measurement locations with Frequency Response Functions (FRFs) measured using a traditional modal-type impact (tap) test at the same locations. The derived forcing functions were then used with tap test FRFs measured at additional locations of interest to produce the desired response data.

  10. Biodiversity and Complexity Influence Seagrass Functioning: A Comparative-Experimental Approach Across the Northern Hemisphere

    Science.gov (United States)

    Reynolds, P. L.

    2016-02-01

    Coastal ecosystems are mediated by interactions between resource supply, consumer pressure, and community composition, with the balance shifting along environmental gradients. Comparative-experimental approaches, including observational and experimental networks, are a promising way forward to organizing this complexity into predictive models and to quantify the role of biodiversity on ocean processes. Through the Zostera Experimental Network we utilize this approach to study the community ecology of eelgrass (Zostera marina), the most widespread marine plant and foundation of important but threatened coastal ecosystems throughout the northern hemisphere. In 2014, parallel field surveys and experiments were conducted at 50 field sites to measure correlations between mesograzer species diversity, eelgrass genetic diversity, predation pressure, and seagrass dynamics. Biodiversity was positively correlated with plant and grazer biomass across sites. Predation pressure in these systems decreased with grazer biomass and latitude. In subsequent experiments in 2015, habitat complexity influenced the grazer community. These results suggest that the impacts of biodiversity loss on ecosystems will be of comparable magnitude to those of other global change factors and should be accounted for in relevant monitoring and restoration activities.

  11. Functional work breaks in a high-demanding work environment: an experimental field study.

    Science.gov (United States)

    Scholz, André; Ghadiri, Argang; Singh, Usha; Wendsche, Johannes; Peters, Theo; Schneider, Stefan

    2018-02-01

    Work breaks are known to have positive effects on employees' health, performance and safety. Using a sample of twelve employees working in a stressful and cognitively demanding working environment, this experimental field study examined how different types of work breaks (boxing, deep relaxation and usual breaks) affect participants' mood, cognitive performance and neurophysiological state compared to a control condition without any break. In a repeated measures experimental design, cognitive performance was assessed using an auditory oddball test and a Movement Detection Test. Brain cortical activity was recorded using electroencephalography. Individual's mood was analysed using a profile of mood state. Although neurophysiological data showed improved relaxation of cortical state after boxing (vs. 'no break' and 'deep relaxation'), neither performance nor mood assessment showed similar results. It remains questionable whether there is a universal work break type that has beneficial effects for all individuals. Practitioner Summary: Research on work breaks and their positive effects on employees' health and performance often disregards break activities. This experimental field study in a stressful working environment investigated the effect of different work break activities. A universal work break type that is beneficial for this workplace could not be identified.

  12. Impulse-response function of splanchnic circulation with model-independent constraints: theory and experimental validation

    DEFF Research Database (Denmark)

    Munk, O L; Keiding, S; Bass, L

    2003-01-01

    from constraining the regression fits by parameters estimated independently. This is strong evidence for the physiological relevance of the impulse-response function, which includes asymptotically, and thereby justifies kinetically, a useful and simple power law. Similarity between our parameter...

  13. Effects of plant diversity, functional group composition, and fertilization on soil microbial properties in experimental grassland.

    Directory of Open Access Journals (Sweden)

    Tanja Strecker

    Full Text Available Loss of biodiversity and increased nutrient inputs are two of the most crucial anthropogenic factors driving ecosystem change. Although both received considerable attention in previous studies, information on their interactive effects on ecosystem functioning is scarce. In particular, little is known on how soil biota and their functions are affected by combined changes in plant diversity and fertilization.We investigated the effects of plant diversity, functional community composition, and fertilization on the biomass and respiration of soil microbial communities in a long-term biodiversity experiment in semi-natural grassland (Jena Experiment. Plant species richness enhanced microbial basal respiration and microbial biomass, but did not significantly affect microbial specific respiration. In contrast, the presence of legumes and fertilization significantly decreased microbial specific respiration, without altering microbial biomass. The effect of legumes was superimposed by fertilization as indicated by a significant interaction between the presence of legumes and fertilization. Further, changes in microbial stoichiometry (C-to-N ratio and specific respiration suggest the presence of legumes to reduce N limitation of soil microorganisms and to modify microbial C use efficiency.Our study highlights the role of plant species and functional group diversity as well as interactions between plant community composition and fertilizer application for soil microbial functions. Our results suggest soil microbial stoichiometry to be a powerful indicator of microbial functioning under N limited conditions. Although our results support the notion that plant diversity and fertilizer application independently affect microbial functioning, legume effects on microbial N limitation were superimposed by fertilization, indicating significant interactions between the functional composition of plant communities and nutrient inputs for soil processes.

  14. Effects of plant diversity, functional group composition, and fertilization on soil microbial properties in experimental grassland.

    Science.gov (United States)

    Strecker, Tanja; Barnard, Romain L; Niklaus, Pascal A; Scherer-Lorenzen, Michael; Weigelt, Alexandra; Scheu, Stefan; Eisenhauer, Nico

    2015-01-01

    Loss of biodiversity and increased nutrient inputs are two of the most crucial anthropogenic factors driving ecosystem change. Although both received considerable attention in previous studies, information on their interactive effects on ecosystem functioning is scarce. In particular, little is known on how soil biota and their functions are affected by combined changes in plant diversity and fertilization. We investigated the effects of plant diversity, functional community composition, and fertilization on the biomass and respiration of soil microbial communities in a long-term biodiversity experiment in semi-natural grassland (Jena Experiment). Plant species richness enhanced microbial basal respiration and microbial biomass, but did not significantly affect microbial specific respiration. In contrast, the presence of legumes and fertilization significantly decreased microbial specific respiration, without altering microbial biomass. The effect of legumes was superimposed by fertilization as indicated by a significant interaction between the presence of legumes and fertilization. Further, changes in microbial stoichiometry (C-to-N ratio) and specific respiration suggest the presence of legumes to reduce N limitation of soil microorganisms and to modify microbial C use efficiency. Our study highlights the role of plant species and functional group diversity as well as interactions between plant community composition and fertilizer application for soil microbial functions. Our results suggest soil microbial stoichiometry to be a powerful indicator of microbial functioning under N limited conditions. Although our results support the notion that plant diversity and fertilizer application independently affect microbial functioning, legume effects on microbial N limitation were superimposed by fertilization, indicating significant interactions between the functional composition of plant communities and nutrient inputs for soil processes.

  15. Functional Analysis and Discovery of Microbial Genes Transforming Metallic and Organic Pollutants: Database and Experimental Tools

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence P. Wackett; Lynda B.M. Ellis

    2004-12-09

    Microbial functional genomics is faced with a burgeoning list of genes which are denoted as unknown or hypothetical for lack of any knowledge about their function. The majority of microbial genes encode enzymes. Enzymes are the catalysts of metabolism; catabolism, anabolism, stress responses, and many other cell functions. A major problem facing microbial functional genomics is proposed here to derive from the breadth of microbial metabolism, much of which remains undiscovered. The breadth of microbial metabolism has been surveyed by the PIs and represented according to reaction types on the University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD): http://umbbd.ahc.umn.edu/search/FuncGrps.html The database depicts metabolism of 49 chemical functional groups, representing most of current knowledge. Twice that number of chemical groups are proposed here to be metabolized by microbes. Thus, at least 50% of the unique biochemical reactions catalyzed by microbes remain undiscovered. This further suggests that many unknown and hypothetical genes encode functions yet undiscovered. This gap will be partly filled by the current proposal. The UM-BBD will be greatly expanded as a resource for microbial functional genomics. Computational methods will be developed to predict microbial metabolism which is not yet discovered. Moreover, a concentrated effort to discover new microbial metabolism will be conducted. The research will focus on metabolism of direct interest to DOE, dealing with the transformation of metals, metalloids, organometallics and toxic organics. This is precisely the type of metabolism which has been characterized most poorly to date. Moreover, these studies will directly impact functional genomic analysis of DOE-relevant genomes.

  16. An Intelligent Robotic Hospital Bed for Safe Transportation of Critical Neurosurgery Patients Along Crowded Hospital Corridors.

    Science.gov (United States)

    Wang, Chao; Savkin, Andrey V; Clout, Ray; Nguyen, Hung T

    2015-09-01

    We present a novel design of an intelligent robotic hospital bed, named Flexbed, with autonomous navigation ability. The robotic bed is developed for fast and safe transportation of critical neurosurgery patients without changing beds. Flexbed is more efficient and safe during the transportation process comparing to the conventional hospital beds. Flexbed is able to avoid en-route obstacles with an efficient easy-to-implement collision avoidance strategy when an obstacle is nearby and to move towards its destination at maximum speed when there is no threat of collision. We present extensive simulation results of navigation of Flexbed in the crowded hospital corridor environments with moving obstacles. Moreover, results of experiments with Flexbed in the real world scenarios are also presented and discussed.

  17. A novel registration method for image-guided neurosurgery system based on stereo vision.

    Science.gov (United States)

    An, Yong; Wang, Manning; Song, Zhijian

    2015-01-01

    This study presents a novel spatial registration method of Image-guided neurosurgery system (IGNS) based on stereo-vision. Images of the patient's head are captured by a video camera, which is calibrated and tracked by an optical tracking system. Then, a set of sparse facial data points are reconstructed from them by stereo vision in the patient space. Surface matching method is utilized to register the reconstructed sparse points and the facial surface reconstructed from preoperative images of the patient. Simulation experiments verified the feasibility of the proposed method. The proposed method it is a new low-cost and easy-to-use spatial registration method for IGNS, with good prospects for clinical application.

  18. The role of executive functioning in children's attentional pain control: an experimental analysis.

    Science.gov (United States)

    Verhoeven, Katrien; Dick, Bruce; Eccleston, Christopher; Goubert, Liesbet; Crombez, Geert

    2014-02-01

    Directing attention away from pain is often used in children's pain treatment programs to control pain. However, empirical evidence concerning its effectiveness is inconclusive. We therefore sought to understand other influencing factors, including executive function and its role in the pain experience. This study investigates the role of executive functioning in the effectiveness of distraction. School children (n=164) completed executive functioning tasks (inhibition, switching, and working memory) and performed a cold-pressor task. One half of the children simultaneously performed a distracting tone-detection task; the other half did not. Results showed that participants in the distraction group were engaged in the distraction task and were reported to pay significantly less attention to pain than controls. Executive functioning influenced distraction task engagement. More specifically, participants with good inhibition and working memory abilities performed the distraction task better; participants with good switching abilities reported having paid more attention to the distraction task. Furthermore, distraction was found to be ineffective in reducing pain intensity and affect. Executive functioning did not influence the effectiveness of distraction. However, a relationship was found between executive functioning and pain affect, indicating that participants with good inhibition and working memory abilities experienced the cold-pressor task as less stressful and unpleasant. Our findings suggest that distraction as a process for managing pain is complex. While it appears that executive function may play a role in adult distraction, in this study it did not direct attention away from pain. It may instead be involved in the overall pain experience. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  19. Effect of land use change on ecosystem function of dung beetles: experimental evidence from Wallacea Region in Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    SHAHABUDDIN

    2011-07-01

    Full Text Available Shahabuddin (2011 Effect of land use change on ecosystem function of dung beetles: experimental evidence from Wallacea Region in Sulawesi, Indonesia. Biodiversitas 12: 177-181. The deforestation of tropical forests and their subsequent conversion to human-dominated land-use systems is one of the most significant causes of biodiversity loss. However clear understanding of the links between ecological functions and biodiversity is needed to evaluate and predict the true environmental consequences of human activities. This study provided experimental evidence comparing ecosystem function of dung beetles across a land use gradient ranging from natural tropical forest and agroforestry systems to open cultivated areas in Central Sulawesi. Therefore, standardized dung pats were exposed at each land-use type to assess dung removal and parasite suppression activity by dung beetles. The results showed that ecosystem function of dung beetles especially dung burial activity were remarkably disrupted by land use changes from natural forest to open agricultural area. Dung beetles presence enhanced about 53% of the total dung removed and reduced about 83% and 63% of fly population and species number respectively, indicating a pronounce contribution of dung beetles in our ecosystem.

  20. Paediatric day-case neurosurgery in a resource challenged setting: Pattern and practice

    Directory of Open Access Journals (Sweden)

    Afolabi Muyiwa Owojuyigbe

    2016-01-01

    Full Text Available Background: It has been generally observed that children achieve better convalescence in the home environment especially if discharged same day after surgery. This is probably due to the fact that children generally tend to feel more at ease in the home environment than in the hospital setting. Only few tertiary health institutions provide routine day-case surgery for paediatric neurosurgical patients in our sub-region. Objective: To review the pattern and practice of paediatric neurosurgical day-cases at our hospital. Patients and Methods: A prospective study of all paediatric day-case neurosurgeries carried out between June 2011 and June 2014. Results: A total of 53 patients (34 males and 19 females with age ranging from 2 days to 14 years were seen. Majority of the patients (77.4% presented with congenital lesions, and the most common procedure carried out was spina bifida repair (32% followed by ventriculoperitoneal shunt insertion (26.4% for hydrocephalus. Sixty-eight percentage belonged to the American Society of Anesthesiologists physical status class 2, whereas the rest (32% belonged to class 1. General anaesthesia was employed in 83% of cases. Parenteral paracetamol was used for intra-operative analgesia for most of the patients. Two patients had post-operative nausea and vomiting and were successfully managed. There was no case of emergency re-operation, unplanned admission, cancellation or mortality. Conclusion: Paediatric day-case neurosurgery is feasible in our environment. With careful patient selection and adequate pre-operative preparation, good outcome can be achieved.

  1. Neurosurgical Resident Error: A Survey of U.S. Neurosurgery Residency Training Program Directors' Perceptions.

    Science.gov (United States)

    Gupta, Raghav; Moore, Justin M; Adeeb, Nimer; Griessenauer, Christoph J; Schneider, Anna M; Gandhi, Chirag D; Harsh, Griffith R; Thomas, Ajith J; Ogilvy, Christopher S

    2018-01-01

    Efforts to address resident errors and to enhance patient safety have included systemic reforms, such as the Accreditation Council for Graduate Medical Education's (ACGME's) mandated duty-hour restrictions, and specialty-specific initiatives such as the neurosurgery Milestone Project. However, there is currently little data describing the basis for these errors or outlining trends in neurosurgical resident error. An online questionnaire was distributed to program directors of 108 U.S. neurosurgery residency training programs to assess the frequency, most common forms and causes of resident error, the resulting patient outcomes, and the steps taken by residency programs to address these errors. Thirty-one (28.7%) responses were received. Procedural/surgical error was the most commonly observed type of error. Transient injury and no injury to the patient were perceived to be the 2 most frequent outcomes. Inexperience or resident mistake despite adequate training were cited as the most common causes of error. Twenty-three (74.2%) respondents stated that a lower post graduate year level correlated with an increased incidence of errors. There was a trend toward an association between an increased number of residents within a program and the number of errors attributable to a lack of supervision (r = 0.36; P = 0.06). Most (93.5%) program directors do not believe that mandated duty-hour restrictions reduce error frequency. Program directors believe that procedural error is the most commonly observed form of error, with post graduate year level believed to be an important predictor of error frequency. The perceived utility of systemic reforms that aim to reduce the incidence of resident error remains unclear. Copyright © 2017. Published by Elsevier Inc.

  2. Impact of insurance precertification on neurosurgery practice and health care delivery.

    Science.gov (United States)

    Menger, Richard P; Thakur, Jai Deep; Jain, Gary; Nanda, Anil

    2017-08-01

    OBJECTIVE Insurance preauthorization is used as a third-party tool to reduce health care costs. Given the expansion of managed care, the impact of the insurance preauthorization process in delaying health care delivery warrants investigation through a diversified neurosurgery practice. METHODS Data for 1985 patients were prospectively gathered over a 12-month period from July 1, 2014, until June 30, 2015. Information regarding attending, procedure, procedure type, insurance type, need for insurance approval, number of days for authorization, or insurance denial was obtained. Delay in authorization was defined as any wait period greater than 7 days. Some of the parameters were added retrospectively to enhance this study; hence, the total number of subjects may vary for different variables. RESULTS The most common procedure was back surgery with instrumentation (28%). Most of the patients had commercial insurance (57%) while Medicaid was the least common (1%). Across all neurosurgery procedures, insurance authorization, on average, was delayed 9 days with commercial insurance, 10.7 days with Tricare insurance, 8.5 days with Medicare insurance, 11.5 days with Medicaid, and 14.4 days with workers' compensation. Two percent of all patients were denied insurance preauthorization without any statistical trend or association. Of the 1985 patients, 1045 (52.6%) patients had instrumentation procedures. Independent of insurance type, instrumentation procedures were more likely to have delays in authorization (p = 0.001). Independent of procedure type, patients with Tricare (military) insurance were more likely to have a delay in approval for surgery (p = 0.02). Predictably, Medicare insurance was protective against a delay in surgery (p = 0.001). CONCLUSIONS Choice of insurance provider and instrumentation procedures were independent risk factors for a delay in insurance preauthorization. Neurosurgeons, not just policy makers, must take ownership to analyze, investigate, and

  3. Augmented reality-guided neurosurgery: accuracy and intraoperative application of an image projection technique.

    Science.gov (United States)

    Besharati Tabrizi, Leila; Mahvash, Mehran

    2015-07-01

    An augmented reality system has been developed for image-guided neurosurgery to project images with regions of interest onto the patient's head, skull, or brain surface in real time. The aim of this study was to evaluate system accuracy and to perform the first intraoperative application. Images of segmented brain tumors in different localizations and sizes were created in 10 cases and were projected to a head phantom using a video projector. Registration was performed using 5 fiducial markers. After each registration, the distance of the 5 fiducial markers from the visualized tumor borders was measured on the virtual image and on the phantom. The difference was considered a projection error. Moreover, the image projection technique was intraoperatively applied in 5 patients and was compared with a standard navigation system. Augmented reality visualization of the tumors succeeded in all cases. The mean time for registration was 3.8 minutes (range 2-7 minutes). The mean projection error was 0.8 ± 0.25 mm. There were no significant differences in accuracy according to the localization and size of the tumor. Clinical feasibility and reliability of the augmented reality system could be proved intraoperatively in 5 patients (projection error 1.2 ± 0.54 mm). The augmented reality system is accurate and reliable for the intraoperative projection of images to the head, skull, and brain surface. The ergonomic advantage of this technique improves the planning of neurosurgical procedures and enables the surgeon to use direct visualization for image-guided neurosurgery.

  4. Integrating risk management data in quality improvement initiatives within an academic neurosurgery department.

    Science.gov (United States)

    McLaughlin, Nancy; Garrett, Matthew C; Emami, Leila; Foss, Sarah K; Klohn, Johanna L; Martin, Neil A

    2016-01-01

    OBJECT While malpractice litigation has had many negative impacts on health care delivery systems, information extracted from lawsuits could potentially guide toward venues to improve care. The authors present a comprehensive review of lawsuits within a tertiary academic neurosurgical department and report institutional and departmental strategies to mitigate liability by integrating risk management data with quality improvement initiatives. METHODS The Comprehensive Risk Intelligence Tool database was interrogated to extract claims/suits abstracts concerning neurosurgical cases that were closed from January 2008 to December 2012. Variables included demographics of the claimant, type of procedure performed (if any), claim description, insured information, case outcome, clinical summary, contributing factors and subfactors, amount incurred for indemnity and expenses, and independent expert opinion in regard to whether the standard of care was met. RESULTS During the study period, the Department of Neurosurgery received the most lawsuits of all surgical specialties (30 of 172), leading to a total incurred payment of $4,949,867. Of these lawsuits, 21 involved spinal pathologies and 9 cranial pathologies. The largest group of suits was from patients with challenging medical conditions who underwent uneventful surgeries and postoperative courses but filed lawsuits when they did not see the benefits for which they were hoping; 85% of these claims were withdrawn by the plaintiffs. The most commonly cited contributing factors included clinical judgment (20 of 30), technical skill (19 of 30), and communication (6 of 30). CONCLUSIONS While all medical and surgical subspecialties must deal with the issue of malpractice and liability, neurosurgery is most affected both in terms of the number of suits filed as well as monetary amounts awarded. To use the suits as learning tools for the faculty and residents and minimize the associated costs, quality initiatives addressing the

  5. Factors associated with burnout among US neurosurgery residents: a nationwide survey.

    Science.gov (United States)

    Attenello, Frank J; Buchanan, Ian A; Wen, Timothy; Donoho, Daniel A; McCartney, Shirley; Cen, Steven Y; Khalessi, Alexander A; Cohen-Gadol, Aaron A; Cheng, Joseph S; Mack, William J; Schirmer, Clemens M; Swartz, Karin R; Prall, J Adair; Stroink, Ann R; Giannotta, Steven L; Klimo, Paul

    2018-02-09

    OBJECTIVE Excessive dissatisfaction and stress among physicians can precipitate burnout, which results in diminished productivity, quality of care, and patient satisfaction and treatment adherence. Given the multiplicity of its harms and detriments to workforce retention and in light of the growing physician shortage, burnout has garnered much attention in recent years. Using a national survey, the authors formally evaluated burnout among neurosurgery trainees. METHODS An 86-item questionnaire was disseminated to residents in the American Association of Neurological Surgeons database between June and November 2015. Questions evaluated personal and workplace stressors, mentorship, career satisfaction, and burnout. Burnout was assessed using the previously validated Maslach Burnout Inventory. Factors associated with burnout were determined using univariate and multivariate logistic regression. RESULTS The response rate with completed surveys was 21% (346/1643). The majority of residents were male (78%), 26-35 years old (92%), in a stable relationship (70%), and without children (73%). Respondents were equally distributed across all residency years. Eighty-one percent of residents were satisfied with their career choice, although 41% had at some point given serious thought to quitting. The overall burnout rate was 67%. In the multivariate analysis, notable factors associated with burnout included inadequate operating room exposure (OR 7.57, p = 0.011), hostile faculty (OR 4.07, p = 0.008), and social stressors outside of work (OR 4.52, p = 0.008). Meaningful mentorship was protective against burnout in the multivariate regression models (OR 0.338, p = 0.031). CONCLUSIONS Rates of burnout and career satisfaction are paradoxically high among neurosurgery trainees. While several factors were predictive of burnout, including inadequate operative exposure and social stressors, meaningful mentorship proved to be protective against burnout. The documented negative effects of

  6. [Experimental endolymphatic hydrops and its related morphological and functional changes in guinea pigs].

    Science.gov (United States)

    Ye, Y

    1990-04-01

    The endolymphatic hydrops was induced successfully in 13 guinea pigs by blocking the endolymphatic duct and sac, and the morphological and functional alterations (especially on semicircular canal function) after hydrops were studied by means of ENG, EcochG and serial section techniques. Hydrops in the cochlear duct was evident in the apical and/or near apical turns, especially in earlier stages. Dilation of the saccule was seen in all samples, but was barely noticeable in the utricle and semicircular canal's endolymphatic space. Degeneration in the corti's apparatus, stria vasculi and spiral ganglion occurred late. No evident changes of the sensory components in the saccule, utricle and semicircular canals were seen under the light microscope. The hearing loss in earlier stages of hydrops was evident at lower frequencies: later stages showed effects at all frequencies. The cochlear recruitment and fluctuation phenomena were observed in a few of the operated animals. The value of -SP/CAP in a few animals was significantly after operation. The functional changes of semicircular canals were demonstrated by the semicircular paralysis (CP), directional preponderance (DP), vestibular recruitment (VR) and elevated threshold of nystagmus to angular acceleration stimuli. There was no significant correlation between the degrees of hearing loss and impaired semicircular function. The criteria of ENG elicited by the quantitative angular acceleration stimuli for evaluating the semicircular canal function in guinea pigs is proposed for the first time in our experiment.

  7. Experimental and clinical studies with radiofrequency-induced thermal endometrial ablation for functional menorrhagia

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, J.H.; Lewis, B.V.; Prior, M.V.; Roberts, T. (Watford General Hospital, Herts (England))

    1990-11-01

    A method of ablating the endometrium has been introduced into clinical practice that uses radiofrequency electromagnetic energy to heat the endometrium, using a probe inserted through the cervix. Preliminary studies suggest that over 80% of patients treated will develop either amenorrhea or a significant reduction in flow. The advantages of radiofrequency endometrial ablation over laser ablation or resection are the avoidance of intravascular fluid absorption, simplicity (no special operative hysteroscopic skills are required), speed of operation, and reduced cost compared with the Nd:YAG laser. In this paper, we describe the experimental studies performed during development of this new technique.

  8. Selberg zeta functions and transfer operators an experimental approach to singular perturbations

    CERN Document Server

    Fraczek, Markus Szymon

    2017-01-01

    This book presents a method for evaluating Selberg zeta functions via transfer operators for the full modular group and its congruence subgroups with characters. Studying zeros of Selberg zeta functions for character deformations allows us to access the discrete spectra and resonances of hyperbolic Laplacians under both singular and non-singular perturbations. Areas in which the theory has not yet been sufficiently developed, such as the spectral theory of transfer operators or the singular perturbation theory of hyperbolic Laplacians, will profit from the numerical experiments discussed in this book. Detailed descriptions of numerical approaches to the spectra and eigenfunctions of transfer operators and to computations of Selberg zeta functions will be of value to researchers active in analysis, while those researchers focusing more on numerical aspects will benefit from discussions of the analytic theory, in particular those concerning the transfer operator method and the spectral theory of hyperbolic spac...

  9. Experimental Approaches for Defining Functional Roles of Microbes in the Human Gut

    DEFF Research Database (Denmark)

    Dantas, Gautam; Sommer, Morten; Degnan, Patrick H.

    2013-01-01

    ofmicrobial genome and community profiling projects, and the loss-of-function and gain-of-function strategies long employed in model organisms are now being extended to microbial genes, species, and communities from the human gut. These developments promise to deepen our understanding of human gut host–microbiota......The complex and intimate relationship between humans and their gut microbial communities is becoming less obscure, due in part to large-scale gut microbial genome-sequencing projects and culture-independent surveys of the composition and gene content of these communities.These studies build upon...

  10. The influence of iron deficiency on the functioning of skeletal muscles: experimental evidence and clinical implications.

    Science.gov (United States)

    Stugiewicz, Magdalena; Tkaczyszyn, Michał; Kasztura, Monika; Banasiak, Waldemar; Ponikowski, Piotr; Jankowska, Ewa A

    2016-07-01

    Skeletal and respiratory myopathy not only constitutes an important pathophysiological feature of heart failure and chronic obstructive pulmonary disease, but also contributes to debilitating symptomatology and predicts worse outcomes in these patients. Accumulated evidence from laboratory experiments, animal models, and interventional studies in sports medicine suggests that undisturbed systemic iron homeostasis significantly contributes to the effective functioning of skeletal muscles. In this review, we discuss the role of iron status for the functioning of skeletal muscle tissue, and highlight iron deficiency as an emerging therapeutic target in chronic diseases accompanied by a marked muscle dysfunction. © 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.

  11. Experimental excitation functions of deuteron induced reactions on natural thallium up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Adam Rebeles, R., E-mail: radamreb@vub.ac.be [Cyclotron Laboratory, Vrije Universiteit Brussel, B-1090 Brussels (Belgium); Van den Winkel, P.; Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel, B-1090 Brussels (Belgium); Tarkanyi, F.; Takacs, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen H-4026 (Hungary)

    2012-10-01

    Excitation functions of deuteron induced reactions on natural thallium leading to the formation of {sup 204m,203m2+m1+g,202m,201m+g,200}Pb and {sup 202,201m+g,200m+g}Tl isotopes were determined up to 50 MeV. The cross sections were measured by an activation technique using stacked foil irradiation. The excitation functions of the investigated reactions are compared with data reported in literature and also with the theoretical results of TALYS nuclear reaction code. From the measured cross section data, the thick target yield for the medical interesting {sup 203}Pb isotope is calculated.

  12. Experimental and theoretical spectroscopic studies of anticancer drug rosmarinic acid using HF and density functional theory

    Science.gov (United States)

    Mariappan, G.; Sundaraganesan, N.; Manoharan, S.

    2012-11-01

    In this work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and NBO analysis of anticancer drug of rosmarinic acid. The optimized molecular structure, atomic charges, vibrational frequencies, natural bond orbital analysis and ultraviolet-visible spectral interpretation of rosmarinic acid have been studied by performing HF and DFT/B3LYP/6-31G(d,p) level of theory. The FT-IR (solid and solution phase), FT-Raman (solid phase) spectra were recorded in the region 4000-400 and 3500-50 cm-1, respectively. The UV-Visible absorption spectra of the compound that dissolved in ethanol were recorded in the range of 200-800 nm. The scaled wavenumbers are compared with the experimental values. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The formation of hydrogen bond was investigated in terms of the charge density by the NBO calculations. Based on the UV spectra and TD-DFT calculations, the electronic structure and the assignments of the absorption bands were carried out. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations.

  13. Experimental use of the obturator internus muscle as a functioning pelvic floor muscle in dogs.

    Science.gov (United States)

    Shafik, A; El-Sibai, O; Shafik, A A

    2001-10-01

    To investigate the possibility of using the obturator internus muscle instead of the levator ani as a pelvic floor muscle. Experimental study. Teaching hospital, Egypt. 7 male and 3 female mongrel dogs. Through a para-anal incision both muscles were exposed; the levator ani was excised and the lower border of the obturator internus was mobilised and sutured to the anorectal junction, the vesical neck, and the vaginal fornix. Rectal and anal pressures and electromyographic (EMG) activity recorded before and during transposition, and 1, 3, and 6 months later. Histological examination of biopsy specimens taken from the levator ani before, and from the obturator internus before, and 3, 6, and 12 months after, transposition. Stimulation of the levator ani caused anal pressure to decline significantly (p obturator internus did not change anal pressure before transposition but caused a decline after it. There was EMG activity in the levator ani at rest, but not in the obturator internus before transposition though it was evident by 6 months afterwards. Levator ani consisted of skeletal muscle fibres with smooth muscle fibres in places, whereas the obturator internus consisted of skeletal fibres alone. Six months after operation examination of the obturator internus showed the presence of some smooth muscle fibres. These results suggest that the obturator internus might be suitable both anatomically and physiologically to replace the levator ani. However, before it can be suggested as a treatment for levator dysfunction syndrome further experimental studies are necessary.

  14. Aberrant function of myeloid-derived suppressor cells (MDSCs) in experimental colitis and in inflammatory bowel disease (IBD) immune responses.

    Science.gov (United States)

    Kontaki, Eleni; Boumpas, Dimitrios T; Tzardi, Maria; Mouzas, Ioannis A; Papadakis, Konstantinos A; Verginis, Panayotis

    2017-05-01

    Myeloid-derived suppressor cells (MDSCs) encompass a novel population of suppressor cells and a potential candidate for cell-based therapies in inflammatory diseases. Herein, we investigated their immunomodulatory properties in experimental inflammatory colitis and T cell-mediated immune responses in inflammatory bowel disease (IBD) patients. MDSCs (defined as CD14 - HLA - DR -/low CD33 + CD15 + ) numbers were determined in peripheral blood (PB) from IBD patients. PB MDSC function was assessed in vitro. Experimental colitis was induced upon 2,4,6-trinitrobenzene sulfonic acid (TNBS) treatment and MDSCs were characterized by flow cytometry. The in vivo suppressive potential of bone marrow (BM)-derived MDSCs (BM-MDSCs) was tested by using both depleting and adoptive transfer strategies. MDSCs were enriched in the periphery of IBD patients during active disease. TNBS colitis induced amplification of MDSCs, particularly of the granulocytic (Ly6G + ) subset during the effector phase of disease. Of interest, BM-MDSCs potently suppressed CD4 +  T cell responses under steady state but failed to control colitis-associated immune responses in vivo. Mechanistically, under the colonic inflammatory milieu MDSCs switched phenotype (decreased proportion of Gr1 high and increased numbers of Gr1 low ) and downregulated CCAAT/enhancer-binding protein beta (CEBPβ) expression, a critical transcription factor for the suppressive function of MDSCs. In accordance with the murine data, human CD33  +  CD15 +  MDSCs from peripheral blood of IBD patients not only failed to suppress autologous T cell responses but instead enhanced T cell proliferation in vitro. Our findings demonstrate an aberrant function of MDSCs in experimental inflammatory colitis and in IBD-associated immune responses in vitro. Delineation of the mechanisms that underlie the loss of MDSCs function in IBD may provide novel therapeutic targets.

  15. The sigma-1 receptor enhances brain plasticity and functional recovery after experimental stroke

    DEFF Research Database (Denmark)

    Ruscher, Karsten; Shamloo, Mehrdad; Rickhag, Karl Mattias

    2011-01-01

    Stroke leads to brain damage with subsequent slow and incomplete recovery of lost brain functions. Enriched housing of stroke-injured rats provides multi-modal sensorimotor stimulation, which improves recovery, although the specific mechanisms involved have not been identified. In rats housed in ...

  16. Biliary obstruction and wound healing, infection, renal function and bloodcoagulation : an experimental study in rats

    NARCIS (Netherlands)

    J.P. Snellen

    1984-01-01

    textabstractThe purpose of the study reported in this thesis, was to investigate the effects of biliary obstruction on wound healing, resistance to infection, renal function and blood coagulation. Disturbances in these processes are often reported in patients with obstructive jaundice, and may lead

  17. Effects of amlodipine on endothelial function in rats with chronic heart failure after experimental myocardial infarction

    NARCIS (Netherlands)

    deVries, RJM; Anthonio, R; vanVeldhuisen, DJ; Buikema, H; vanGilst, WH

    1997-01-01

    In chronic heart failure, the role of endothelial dysfunction is not yet well established. As calcium metabolism plays an important role in the endothelium, it might be suggested that calcium channel blockers influence endothelial function. Although calcium channel blockers are generally

  18. Experimental characterization of the Green’s function in a room using sparse reconstruction principles

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Christiansen, Rasmus Ellebæk

    2017-01-01

    Measuring the Green’s function over the entire volume of a room would typically require an unfeasible number of measurements, due to requirements on spatial sampling. To alleviate the need for excessive measurements, sparse reconstruction methods can be employed, as they make it possible to recon...

  19. Cardiac Function Remains Impaired Despite Reversible Cardiac Remodeling after Acute Experimental Viral Myocarditis

    Directory of Open Access Journals (Sweden)

    Peter Moritz Becher

    2017-01-01

    Full Text Available Background. Infection with Coxsackievirus B3 induces myocarditis. We aimed to compare the acute and chronic phases of viral myocarditis to identify the immediate effects of cardiac inflammation as well as the long-term effects after resolved inflammation on cardiac fibrosis and consequently on cardiac function. Material and Methods. We infected C57BL/6J mice with Coxsackievirus B3 and determined the hemodynamic function 7 as well as 28 days after infection. Subsequently, we analyzed viral burden and viral replication in the cardiac tissue as well as the expression of cytokines and matrix proteins. Furthermore, cardiac fibroblasts were infected with virus to investigate if viral infection alone induces profibrotic signaling. Results. Severe cardiac inflammation was determined and cardiac fibrosis was consistently colocalized with inflammation during the acute phase of myocarditis. Declined cardiac inflammation but no significantly improved hemodynamic function was observed 28 days after infection. Interestingly, cardiac fibrosis declined to basal levels as well. Both cardiac inflammation and fibrosis were reversible, whereas the hemodynamic function remains impaired after healed viral myocarditis in C57BL/6J mice.

  20. Experimental and theoretical excitation functions for natBr(p,x) reactions.

    Science.gov (United States)

    de Villiers, Dawid; Nortier, Meiring; Richter, Werner

    2002-12-01

    The excitation functions for protons incident on natBr were measured from threshold up to 100 MeV by means of the stacked-foil technique. Where applicable, the measured cross-section values are compared with previously published values. Theoretical cross-sections were also calculated by means of the computer code ALICE (IPPE) for comparison purposes.

  1. Lidocaine Stimulates the Function of Natural Killer Cells in Different Experimental Settings.

    Science.gov (United States)

    Cata, Juan P; Ramirez, Maria F; Velasquez, Jose F; Di, A I; Popat, Keyuri U; Gottumukkala, Vijaya; Black, Dahlia M; Lewis, Valerae O; Vauthey, Jean N

    2017-09-01

    One of the functions of natural killer (NK) cells is to eliminate cancer cells. The cytolytic activity of NK cells is tightly regulated by inhibitory and activation receptors located in the surface membrane. Lidocaine stimulates the function of NK cells at clinically relevant concentrations. It remains unknown whether this effect of lidocaine has an impact on the expression of surface receptors of NK cells, can uniformly stimulate across different cancer cell lines, and enhances the function of cells obtained during oncological surgery. NK cells from healthy donors and 43 patients who had undergone surgery for cancer were isolated. The function of NK cells was measured by lactate dehydrogenase release assay. NK cells were incubated with clinically relevant concentrations of lidocaine. By flow cytometry, we determined the impact of lidocaine on the expression of galactosylgalactosylxylosylprotein3-beta-glucuronosytranferase 1, marker of cell maturation (CD57), killer cell lectin like receptor A, inhibitory (NKG2A) receptors and killer cell lectin like receptor D, activation (NKG2D) receptors of NK cells. Differences in expression at pLidocaine increased the expression of NKG2D receptors and stimulated the function of NK cells against ovarian, pancreatic and ovarian cancer cell lines. Lidocaine also increased the cytolytic activity of NK cells from patients who underwent oncological surgery, except for those who had orthopedic procedures. Lidocaine showed an important stimulatory activity on NK cells. Our findings suggest that lidocaine might be used perioperatively to minimize the impact of surgery on NK cells. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  2. Experimental and Simulative Study on Accumulator Function in The Process of Wave Energy Conversion

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2016-09-01

    Full Text Available In this paper, a floating-buoy wave energy converter using hydrostatic transmission system is studied. The entire work progress of wave energy power generation device is introduced, and the hydraulic transmission principles are emphasized through the simulation to verify the feasibility of design principle of hydraulic transmission system. The mathematical model of the accumulator is established and applied in the AMEsim simulation. The simulation results show that the accumulator plays an important role in the wave power hydraulic transmission system and that the correct configuration of accumulator parameters can improve the rapidity and stability of the system work. Experimental results are compared with the simulation results to validate the correctness of the simulation results. This would provide a valuable reference to the optimal design of wave power generation.

  3. Deuteron induced reactions on Ho and La: Experimental excitation functions and comparison with code results

    Energy Technology Data Exchange (ETDEWEB)

    Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussel 1090 (Belgium); Adam-Rebeles, R. [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussel 1090 (Belgium); Tarkanyi, F.; Takacs, S.; Csikai, J. [Institute for Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Takacs, M.P. [Institute of Physics, University of Debrecen, 4026 Debrecen (Hungary); Ignatyuk, A. [Institute of Physics and Power Engineering, Obninsk 246020 (Russian Federation)

    2013-09-15

    Activation products of rare earth elements are gaining importance in medical and technical applications. In stacked foil irradiations, followed by high resolution gamma spectroscopy, the cross-sections for production of {sup 161,165}Er, {sup 166g}Ho on {sup 165}Ho and {sup 135,137m,137g,139}Ce, {sup 140}La, {sup 133m,133g,cum}Ba and {sup 136}Cs on {sup nat}La targets were measured up to 50 MeV. Reduced uncertainty is obtained by simultaneous remeasurement of the {sup 27}Al(d,x){sup 24,22}Na monitor reactions over the whole energy range. A comparison with experimental literature values and results from updated theoretical codes (ALICE-D, EMPIRE-D and the TENDL2012 online library) is discussed.

  4. Natural dye extracted from karkadah and its application in dye-sensitized solar cells: experimental and density functional theory study.

    Science.gov (United States)

    Reda, S M; Soliman, K A

    2016-02-01

    This work presents an experimental and theoretical study of cyanidin natural dye as a sensitizer for ZnO dye-sensitized solar cells. ZnO nanoparticles were prepared using ammonia and oxalic acid as a capping agent. The calculated average size of the synthesized ZnO with different capping agents was found to be 32.1 nm. Electronic properties of cyanidin and delphinidin dye were studied using density functional theory (DFT) and time-dependent DFT with a B3LYP/6-31G(d,p) level. By comparing the theoretical results with the experimental data, the cyanidin dye can be used as a sensitizer in dye-sensitized solar cells. An efficiency of 0.006% under an AM-1.5 illumination at 100  mW/cm(2) was attained. The influence of dye adsorption time on the solar cell performance is discussed.

  5. Monte Carlo calculation of the spatial response (Modulated Transfer Function) of a scintillation flat panel and comparison with experimental results

    Science.gov (United States)

    Juste, Belén; Miró, Rafael; Monasor, Paula; Verdú, Gumersindo

    2015-11-01

    Phosphor screens are commonly used in many X-ray imaging applications. The design and optimization of these detectors can be achieved using Monte Carlo codes to simulate radiation transport in scintillation materials and to improve the spatial response. This work presents an exhaustive procedure to measure the spatial resolution of a scintillation flat panel image and to evaluate the agreement with data obtained by simulation. To evaluate the spatial response we have used the Modulated Transfer Function (MTF) parameter. According to this, we have obtained the Line Spread Function (LSF) of the system since the Fourier Transform (FT) of the LSF gives the MTF. The experimental images were carried out using a medical X-ray tube (Toshiba E7299X) and a flat panel (Hammamatsu C9312SK). Measurements were based on the slit methodology experimental implementation, which measures the response of the system to a line. LSF measurements have been performed using a 0.2 mm wide lead slit superimposed over the flat panel. The detector screen was modelled with MCNP (version 6) Monte Carlo simulation code in order to analyze the effect of the acquisition setup configuration and to compare the response of scintillator screens with the experimental results. MCNP6 offers the possibility of studying the optical physics parameters (optical scattering and absorption coefficients) that occur in the phosphor screen. The study has been tested for different X-ray tube voltages, from 100 to 140 kV. An acceptable convergence between the MTF results obtained with MCNP6 and the experimental measurements have been obtained.

  6. Functional recovery after experimental RPE debridement, mfERG studies in a porcine model

    DEFF Research Database (Denmark)

    Sørensen, Nina Buus; Lassota, Nathan; Kyhn, Maria Voss

    2013-01-01

    BACKGROUND: The correlation between histologically identified regeneration of retinal pigment epithelium (RPE) and functional outcome measured by multifocal electroretinography (mfERG) following surgical debridement is examined in a porcine model. In humans, visual acuity is reduced in diseases...... with RPE loss such as RPE tears and geographic atrophy. Hypopigmented RPE is known to cover the lesion after RPE debridement in the pig, but it is unclear whether this leads to a return of photoreceptor function. METHODS: RPE debridement was performed in ten pigs by vitrectomy and retinotomy......, and by brushing the Bruch's membrane with a silicone catheter. Immediately following surgery (baseline) and after 2 and 6 weeks respectively, the animals were examined by mfERG, fundus photographs (FPs), fluorescein angiograms (FAs), and histopathology. RESULTS: The mfERG P1 amplitude was decreased 2 weeks (T2...

  7. [Paraplegic cycling using functional electrical stimulation. Experimental and model-based study of power output].

    Science.gov (United States)

    Szecsi, J; Krafczyk, S; Quintern, J; Fiegel, M; Straube, A; Brandt, T

    2004-12-01

    Cycling using functional electrical stimulation offers paraplegics the possibility of muscle and cardiovascular training as well as the chance for independent locomotion. To investigate whether this method might be suitable for a large group of paraplegics, the first German feasibility study of functional electrical stimulation (FES) cycling with seven paraplegic patients was started at the beginning of 2003. Even at the beginning of the study, and without training, these patients were able to drive distances of 0.5-1.6 km. To stimulate cardiovascular adaptation processes in the case of FES ergometer training or to cover useful distances in the case of FES cycling, a minimum amount of generated mechanical output power is required, which as a rule cannot be achieved yet. In this study, we point out two particular aspects of FES cycling, which impair power output: prolonged fatigue mode and viscous joint friction of the paraplegic FES cyclist. We discuss current possibilities for increasing output power and endurance.

  8. Fast detection of renal ischemia in transplanted kidneys with delayed graft function-an experimental study.

    Science.gov (United States)

    Keller, Anna K; Jørgensen, Troels M; Vittrup, Dorthe M; Kjerkegaard, Ulrik K; Jespersen, Bente; Krag, Søren R P; Bibby, Bo M; Stolle, Lars B

    2013-01-27

    The newly transplanted kidney is difficult to monitor with regard to postoperative vascular thrombosis, especially when there is delayed graft function. We evaluated microdialysis as a tool for early ischemia detection in porcine kidneys with delayed graft function early after transplantation. Sixteen pigs were transplanted with 26-hr cold ischemia kidneys. A microdialysis catheter was placed in the lateral renal cortex. Five hours after graft reperfusion, the pigs were randomized to renal arterial clamping or open artery, n=8 in each group, and further observed for 2 hr. The diuresis and glomerular filtration rate were low and decreasing throughout the study, with no significant differences between groups. Until arterial clamping, there were no significant differences in the development of local renal metabolites between the two groups. Renal artery clamping immediately caused significantly different development of all metabolites (Pmonitoring and detection of thrombosis after renal transplantation.

  9. Experimental functional analysis of severe skin-picking behavior in Prader-Willi syndrome.

    Science.gov (United States)

    Hall, Scott S; Hustyi, Kristin M; Chui, Clara; Hammond, Jennifer L

    2014-10-01

    Skin picking is an extremely distressing and treatment resistant behavior commonly shown by individuals with Prader-Willi syndrome (PWS). However, with the exception of a limited number of published single-case and survey studies, little is known about the environmental determinants of skin picking in this population. In this study, functional analyses were conducted with thirteen individuals with PWS, aged 6-23 years, who engaged in severe skin-picking behavior. In addition to the conditions typically employed in a functional analysis (i.e., alone, attention, play, demand), we included an ignore condition to examine potential effects of stimulus control by the presence of an adult. Twelve participants engaged in skin picking during the functional analysis, with the highest levels occurring in the alone and ignore conditions for eight participants, suggesting that skin picking in these participants was maintained by automatic reinforcement. For the remaining four participants, an undifferentiated pattern of low-rate skin picking was observed across conditions. These data confirm previous studies indicating that skin picking in PWS may be maintained most often by automatically produced sensory consequences. There were no associations between demographic characteristics of the participants (e.g., sex, age, IQ or BMI) and levels of skin picking observed in the functional analysis. Additional investigations are needed to identify the nature of the sensory consequences produced during episodes of skin picking in PWS. Behavioral interventions designed to extinguish or compete with the potential sensory consequences arising from skin picking in PWS are also warranted. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Experimental-confirmation and functional-annotation of predicted proteins in the chicken genome

    OpenAIRE

    McCarthy Fiona M; Buza Teresia J; Burgess Shane C

    2007-01-01

    Abstract Background The chicken genome was sequenced because of its phylogenetic position as a non-mammalian vertebrate, its use as a biomedical model especially to study embryology and development, its role as a source of human disease organisms and its importance as the major source of animal derived food protein. However, genomic sequence data is, in itself, of limited value; generally it is not equivalent to understanding biological function. The benefit of having a genome sequence is tha...

  11. Toxicity of mercury in macrophages. Structure and function of macrophages after experimental mercury exposure

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, M.M.

    1995-12-31

    Mercury is recognized as an environmental heavy metal pollutant with a toxic effect on living organisms. The toxicity of this heavy metal at cellular level is described for many types of cells. Macrophages are ubiquitous in the organism and play a central role in the non-specific defence barrier against intruding micro-organisms. As a first line of defence, macrophages are crucial for the course of generalized infection, for instance with herpes simplex virus. Functions such as phagocytosis, migration, activation during infection and cytokine production are important in this context. Mercury, detectable by auto metallography, is found in the lysosomes of macrophages and this accumulation is dependent upon dose and length of time of mercury exposure. But higher concentrations cause auto interference, which indicates that mercury accumulation is dependent on lysosome functional integrity and that mercury inhibits lysosome functions. In mice intraperitoneally exposed to mercury chloride, mercury is found localized in the lysosomes of macrophages in the spleen, thymus, lymph nodes and liver as well as in peritoneal macrophages. The effect of mercury on a virus infection was examined in studies of the course of infection in mice treated with mercury and infected with herpes simplex virus type 2 (HSV-2) under further exposure to mercury. To further elucidate aspects of interactions between heavy metals and macrophages and their eventual significance for the antiviral effect of macrophages, the effect of mercury on cell respiratory burst capacity and the influence of mercury on cell production of and reaction to cytokines was examined. This thesis shows that mercury is immunotoxic in that it affects macrophages both with regard to the viability and function of the cells. This is also valid for mercury concentrations that do not result in apparent pathological changes. (EG) 98 refs.

  12. Cardiovascular Magnetic Resonance Relaxometry Predicts Regional Functional Outcome After Experimental Myocardial Infarction.

    Science.gov (United States)

    Haberkorn, Sebastian M; Jacoby, Christoph; Ding, Zhaoping; Keul, Petra; Bönner, Florian; Polzin, Amin; Levkau, Bodo; Schrader, Jürgen; Kelm, Malte; Flögel, Ulrich

    2017-08-01

    Cardiovascular magnetic resonance with gadolinium-based contrast agents has established as gold standard for tissue characterization after myocardial infarction (MI). Beyond accurate diagnosis, the value of cardiovascular magnetic resonance to predict the outcome after MI has yet to be substantiated. Recent cardiovascular magnetic resonance approaches were systematically compared for quantification of tissue injury and functional impairment after MI using murine models with permanent left anterior descending coronary artery ligation (n=14) or 50 minutes ischemia/reperfusion (n=13). Cardiovascular magnetic resonance included native/postcontrast T1 maps, T2 maps, and late gadolinium enhancement at days 1 and 21 post-MI. For regional correlation of parametric and functional measures, the left ventricle was analyzed over 200 sectors. For T1 mapping, we used retrospective triggering with variable flip angle analysis. Sectoral analysis of native T1 maps already revealed in the acute phase after MI substantial discrepancies in myocardial tissue texture between the 2 MI models (native T1 day 1: permanent ligation, 1280.0±162.6 ms; ischemia/reperfusion, 1115.0±140.5 ms; Pfunctional outcome (left ventricular ejection fraction day 21: permanent ligation, 24.5±7.0%; ischemia/reperfusion, 33.7±11.6%; Pfunction in corresponding areas at day 21 demonstrated for early native T1 values the best correlation with the later functional impairment (R2 =0.94). The present T1 mapping approach permits accurate characterization of local tissue injury and holds the potential for sensitive and graduated prognosis of the functional outcome after MI without gadolinium-based contrast agents. © 2017 American Heart Association, Inc.

  13. Experimental verification of modified synthetic discriminant function filters for rotation invariance.

    Science.gov (United States)

    Reid, M B; Ma, P W; Downie, J D; Ochoa, E

    1990-03-10

    A modified binary synthetic discriminant function filter designed to recognize objects over a range of rotated views has been verified on a laboratory optical correlator. A binary synthetic discriminant function filter has been previously described that will produce a specified correlation response for a set of training images. [See D. A. Jared and D. J. Ennis, "Inclusion of Filter Modulation in Synthetic-Discriminant-Function Construction," Appl. Opt. 28, 232-239 (1989).] In the filter design, the modulation characteristics of the device onto which the filter is mapped are included in the synthesis equations. The system of nonlinear equations is then solved using an iteration procedure based on the Newton-Raphson algorithm. The development of the filter-SDF (fSDF) method was driven by the practical concern to make currently available spatial light modulators with limited modulation capabilities functional for distortion invariant pattern recognition. This technique is used to synthesize filters for a binary magnetooptic spatial light modulator (MOSLM), the Sight-MOD produced by Semetex. Two MOSLMs are used in the laboratory correlator, one in the filter plane and one in the input plane. We demonstrate that a single filter produces equal correlation peaks for a sample object (a Shuttle Orbiter in these tests) over in-plane and out-of-plane rotation ranges up to 75 degrees . The correlator is able to track dynamically the shuttle as it moves along a curved path across the input field. Views of the object in between those in the training set are also recognized when training images are sufficiently close in angle (~5 degrees apart).

  14. Can CF3-Functionalized La@C60 Be Isolated Experimentally and Become Superconducting?

    Science.gov (United States)

    Guan, Jie; Tománek, David

    2017-06-01

    Superconducting behavior even under harsh ambient conditions is expected to occur in La@C(60) if it could be isolated from the primary metallofullerene soot when functionalized by CF(3) radicals. We use ab initio density functional theory calculations to compare the stability and electronic structure of C(60) and the La@C(60) endohedral metallofullerene to their counterparts functionalized by CF(3). We found that CF(3) radicals favor binding to C(60) and La@C(60), and have identified the most stable isomers. Structures with an even number m of radicals are energetically preferred for C(60) and structures with odd m for La@C(60) due to the extra charge on the fullerene. This is consistent with a wide HOMO-LUMO gap in La@C(60)(CF(3))(m) with odd m, causing extra stabilization in the closed-shell electronic configuration. CF(3) radicals are both stabilizing agents and molecular separators in a metallic crystal, which could increase the critical temperature for superconductivity.

  15. Intestinal flora imbalance results in altered bacterial translocation and liver function in rats with experimental cirrhosis.

    Science.gov (United States)

    Zhang, Wei; Gu, Yurong; Chen, Youming; Deng, Hong; Chen, Lubiao; Chen, Sui; Zhang, Genglin; Gao, Zhiliang

    2010-12-01

    The intestinal microflora plays a major role in human health. Intestinal flora imbalances are seen in clinical settings, such as cirrhosis, in which bacterial translocation (BT) results in migration of bacteria or bacterial products from the intestinal lumen to extraintestinal sites. In this study, we explored the effect of alterations in gut flora on BT and liver function in cirrhotic rats. In this study, we used a carbon tetrachloride-induced cirrhotic rat model to compare the abundance of major aerobic and anaerobic bacterial species in healthy and cirrhotic rats. We used antibiotic (norfloxacin) and different probiotic treatments to change the status of gut flora in the cirrhotic rats and evaluated BT, liver function, and endotoxemia in the different models. We found higher levels of Enterobacteriaceae in cirrhotic rats when compared with healthy rats. Bifidobacteria treatment resulted in lower levels of Enterobacteriaceae along with increased levels of Lactobacillus when compared with the normal saline group. Both Bifidobacteria and Enterococcus treatments resulted in lower endotoxin levels than in the normal saline group. Gut flora imbalances in cirrhotic rats result in significant changes in BT and liver function in cirrhotic rats.

  16. Pycnogenol® and its fractions influence the function of isolated heart in rats with experimental diabetes mellitus.

    Science.gov (United States)

    Kralova, Eva; Jankyova, Stanislava; Mucaji, Pavel; Gresakova, Eva; Stankovicova, Tatiana

    2015-02-01

    The aim of this study was to test the effect of Pycnogenol(®) (PYC) mixture and its three fractions (buthanolic, water, ethyl acetate) on heart function in rats with experimental diabetes mellitus (DM) and compare their effects to the diabetic group. Their antioxidant activity "in vitro" was also determined. DM rats (streptozotocin over 3 consecutive days at a dose of 25 mg/kg of body weight) had increased systolic blood pressure, thicker left ventriculi wall (LV) and weaker myocardial contraction, prolonged QT interval in comparison to controls rats. In comparison to the diabetic group, PYC (20 mg/kg b.w./day) suppressed the influence of DM on the LV, improved contraction, increased coronary flow and displayed negative effect on electrical activity of hearts. The most effective of PYC's fractions was the water fraction. It improved biometric parameters and hemodynamic function of the DM hearts, enhanced shortening the QT interval, reduced the amount of dysrhythmias of the DM hearts and had the strongest antioxidant activity. In conclusion, DM damaged isolated rat heart function. Only the water fraction improved the function of the diabetic heart. The different results of three fractions and PYC on myocardial function may be caused by a various lipo- and hydro-philic action of the PYC components. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. [Experimental study of the influence of mandibular distraction osteogenesis on inferior alveolar nerve function].

    Science.gov (United States)

    Wang, Xiaoxia; Wang, Xing; Li, Zili; Yang, Zhaohui

    2002-01-01

    To evaluate the influence of mandibular distraction osteogenesis on inferior alveolar nerve function. 16 young Macaca rhesus monkeys were used as experiment animals. 5 days after mandibular osteotomy under general anesthesia, 10 male monkeys were distracted at right side and 6 females were bilaterally distracted at a rate of 0.5 mm x 2/day, for 15 days. The mandible was lengthened to an average of 13.5 mm. The Sensory Nerve Action Potential (SNAP) test was successfully applied in 16 monkeys before operation and at 0, 2, 4, 6, 9 and 12 weeks after distraction finished. Eight-channel EMG equipment was used for SNAP wave recording. The recordings were made with needle electrodes at foramen ovale and the stimulation was done at the mental foramen with two surface electrodes. The metal ground electrode was fixed on the right forearm. The stimulation intensities were five times of thresholds of each animal. The latency was measured at the first wave peak and the amplitude was measured between two wave peaks. Just after distraction finished, the latency period was 22.18% longer than before operation and gradually shortened as time lapsed. When distraction finished, the amplitude of SNAP wave was only 28.54% of that before operation, and after 12 weeks, it increased to the level of 99.84% of that before operation. The mandibular distraction osteogenesis has temporary influence on the function of inferior alveolar nerve, but it is little and reversible, along with the regeneration of nerve sheath and axon, the nerve function can gradually return to normal level.

  18. Functional properties of butter oil made from bovine milk with experimentally altered fat composition.

    Science.gov (United States)

    Ortiz-Gonzalez, G; Jimenez-Flores, R; Bremmer, D R; Clark, J H; DePeters, E J; Schmidt, S J; Drackley, J K

    2007-11-01

    Modification of milk fat composition might be desirable to alter manufacturing characteristics or produce low saturated fat dairy products that more closely meet consumer dietary preferences. The aim of this research was to evaluate functional properties of butter oil obtained from milks with fat composition modified by altering the profile of long-chain fatty acids (FA) absorbed from the small intestine of cows. A control and 5 mixtures of long-chain free FA were infused into the abomasum of lactating dairy cows in a 6 x 6 Latin square design with 21-d periods. Treatments were 1) control (no FA infused), 2) mostly saturated FA (C16:C18 = 0.72), 3) low-linoleic palm FA (C16:C18 = 0.85), 4) palm FA (C16:C18 = 0.72), 5) soy FA (C16:C18 = 0.10), and 6) high-palmitic soy FA (C16:C18 = 0.68). All treatments included meat solubles and Tween 80 as emulsifiers. Solid fat content (from 0 to 40 degrees C), melting point, and force at fracture were determined in butter oil. Milk fat from cows infused with palm FA (treatment 4) exhibited functionality equal to or better than control butter oil. Infusion with palm FA increased amounts of triglyceride (TG) fractions with 48, 52, and 54 carbon numbers but decreased TG with 32, 34, 36, and 42 carbon numbers. Infusion with soy FA increased TG with 26, 38, 40, 52, and 54 carbon numbers but decreased TG with 34, 42, and 46 carbons. Infusion of the mostly saturated FA increased TG with 38, 50, 52, and 54 carbon numbers but decreased TG with 32, 34, and 42 carbon numbers. These TG groups were consistently correlated with functional properties of butter oils from different treatments. The content of palmitic acid is important for maintaining functionality in the presence of increased polyunsaturated FA. The composition of milk fat may be able to be optimized through nutritional manipulation of diets for dairy cows if the optimal composition of FA and TG is defined for a particular dairy product.

  19. [Biochemical and functional changes in experimental acute pancreatitis in the rat].

    Science.gov (United States)

    Díez Miralles, M; Pardo Correcher, J M; González Santos, J; Graells Ferrer, M L; Ferrando Marco, J; Regalado Pareja, R I; Medrano Heredia, J

    1989-10-01

    To discover the biochemical alterations occurring in the first 24 hours of acute pancreatitis (PA), we made an experimental study using rats. We used 90 animals in which necrosis and hemorrhage were induced by closing the choledochus. Animals underwent evolutive periods of 1, 2, 3, 4, 5, 6, 12, 18 and 24 hours. They were sacrificed and plasma (to determine amylase, lipase, creatinine and calcium), urine (amylase and creatinine), ascitic and pleural liquid (amylase and lipase) were obtained from 6 animals of each evolutive period. We made a post-mortem study of the pancreas of three animals of each subgroup. There was a significant increase in the amylasemia from the third hour (p less than 0.005) and of plasmatic lipase from the first hour (p less than 0.0001). Creatinine values remained in normal range and calcemia fell after the sixth hour (p less than 0.001). There was an increase in amylase concentration in urine and in ascitic and pleural liquids, and of the lipase in the last two. These changes correlated with the duration of the disease and with the histologic changes of the gland, which consist in edema, acinar necrosis, vasculitis and hemorrhage, which are present from the first hour and increase as time passes.

  20. Experimental Gestational Diabetes Mellitus Induces Blunted Vasoconstriction and Functional Changes in the Rat Aorta

    Directory of Open Access Journals (Sweden)

    Cecilia Tufiño

    2014-01-01

    Full Text Available Diabetic conditions increase vascular reactivity to angiotensin II in several studies but there are scarce reports on cardiovascular effects of hypercaloric diet (HD induced gestational diabetes mellitus (GDM, so the objective of this work was to determine the effects of HD induced GDM on vascular responses. Angiotensin II as well as phenylephrine induced vascular contraction was tested in isolated aorta rings with and without endothelium from rats fed for 7 weeks (4 before and 3 weeks during pregnancy with standard (SD or hypercaloric (HD diet. Also, protein expression of AT1R, AT2R, COX-1, COX-2, NOS-1, and NOS-3 and plasma glucose, insulin, and angiotensin II levels were measured. GDM impaired vasoconstrictor response (P<0.05 versus SD in intact (e+ but not in endothelium-free (e− vessels. Losartan reduced GDM but not SD e− vasoconstriction (P<0.01 versus SD. AT1R, AT2R, and COX-1 and COX-2 protein expression were significantly increased in GDM vessels (P<0.05 versus SD. Results suggest an increased participation of endothelium vasodilator mediators, probably prostaglandins, as well as of AT2 vasodilator receptors as a compensatory mechanism for vasoconstrictor changes generated by experimental GDM. Considering the short term of rat pregnancy findings can reflect early stage GDM adaptations.

  1. Senolytic drugs target alveolar epithelial cell function and attenuate experimental lung fibrosis ex vivo.

    Science.gov (United States)

    Lehmann, Mareike; Korfei, Martina; Mutze, Kathrin; Klee, Stephan; Skronska-Wasek, Wioletta; Alsafadi, Hani N; Ota, Chiharu; Costa, Rita; Schiller, Herbert B; Lindner, Michael; Wagner, Darcy E; Günther, Andreas; Königshoff, Melanie

    2017-08-01

    Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor prognosis and limited therapeutic options. The incidence of IPF increases with age, and ageing-related mechanisms such as cellular senescence have been proposed as pathogenic drivers. The lung alveolar epithelium represents a major site of tissue injury in IPF and senescence of this cell population is probably detrimental to lung repair. However, the potential pathomechanisms of alveolar epithelial cell senescence and the impact of senolytic drugs on senescent lung cells and fibrosis remain unknown. Here we demonstrate that lung epithelial cells exhibit increased P16 and P21 expression as well as senescence-associated β-galactosidase activity in experimental and human lung fibrosis tissue and primary cells.Primary fibrotic mouse alveolar epithelial type (AT)II cells secreted increased amounts of senescence-associated secretory phenotype (SASP) factors in vitro, as analysed using quantitative PCR, mass spectrometry and ELISA. Importantly, pharmacological clearance of senescent cells by induction of apoptosis in fibrotic ATII cells or ex vivo three-dimensional lung tissue cultures reduced SASP factors and extracellular matrix markers, while increasing alveolar epithelial markers.These data indicate that alveolar epithelial cell senescence contributes to lung fibrosis development and that senolytic drugs may be a viable therapeutic option for IPF. Copyright ©ERS 2017.

  2. Protective effect of theophylline on renal functions in experimental pneumoperitoneum model.

    Science.gov (United States)

    Ozturk, Sefa Alperen; Ceylan, Cavit; Serel, Tekin Ahmet; Doluoglu, Omer Gokhan; Soyupek, Arap Sedat; Guzel, Ahmet; Özorak, Alper; Uz, Efkan; Savas, Hasan Basri; Baspinar, Sirin

    2015-07-01

    Our objective in this experimental study is to research the effect of the intra-abdominal pressure which rises following pneumoperitoneum and whether Theophylline has a possible protective activity on this situation. In our study, 24 Wistar Albino rats were used. Rats were divided into two groups. The first group was set for only pneumoperitoneum model. The second group was given 15 mg/kg of Theophylline intraperitoneally before setting pneumoperitoneum model. Then urea, creatinine, cystatin-C, tissue and serum total antioxidant capacity, total oxidant capacity and oxidative stress index in two groups were measured and compared with each other. Apoptosis and histopathological conditions in the renal tissues were examined. The differences between the groups were analyzed with the Mann-Whitney U test. Results were considered significant at p 0.05). The mean value of urea were similar in pneumoperitoneum and pneumoperitoneum + theophylline groups (p = 0.12). The mean cystatin-C value was 2.2 ± 0.3 µg/mL in pneumoperitoneum, 1.74 ± 0.33 µg/mL in pneumoperitoneum + theophylline (p = 0.002). According to our study, lower cystatin-C levels in the group, where Theophylline was given, are suggestive of lower renal injury in this group. However, this opinion is interrogated as there is no difference in terms of tissue and serum TAS, TOS, OSI and urea values between the groups.

  3. Experimental study on the effects of massive bowel resection on liver function and hepatocyte apoptosis.

    Science.gov (United States)

    Bostanoğlu, Akın; Oruğ, Taner; Yıldız, Barış Doğu; Işık, Sevil; Zengin, Neslihan İnci; Evren, Ebru; Saydam, Gül Sevim

    2014-12-01

    The effects of short-bowel syndrome on liver function and liver morphology independent of parenteral nutrition have not been thoroughly investigated. Our aim was to investigate the effects of massive bowel resection on hepatocyte apoptosis and liver function in rats. A total of 37 female Sprague-Dawley rats were randomly assigned to five groups: Control (no procedure); Sham 1 [laparotomy (LT)/enterotomy (ET); evaluated on postoperative day (POD) 1]; Sham 2 (LT/ET; evaluated on POD7; Group 1 (80% bowel resection after LT/ET; POD1); and Group 2 (80% bowel resection; POD7). Blood samples were obtained for measuring aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase levels. For assessing hepatocyte apoptosis, liver tissue samples from the median lobe were obtained and used for a terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assay. Aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase levels showed statistically significant differences among the five groups. Apoptotic hepatocyte counts there were statistically significant differences among groups for counts made in 20 consecutive high-power fields. However, liver sinusoidal cell apoptosis rates among groups showed statistically significant differences for counts made in 20 consecutive high-power fields, particularly on POD7 in rats undergoing massive bowel resection. Parenteral nutrition is not the only factor involved in liver dysfunction after massive bowel resection. Massive bowel resection alone can cause liver abnormalities. Rats undergoing massive small intestinal resection show significant temporal increases in liver sinusoidal cell apoptosis rates.

  4. Ascitic fluid of experimental severe acute pancreatitis modulates the function of peritoneal macrophages.

    Science.gov (United States)

    Satoh, A; Shimosegawa, T; Masamune, A; Fujita, M; Koizumi, M; Toyota, T

    1999-10-01

    Although the pathophysiology of acute pancreatitis appears to be greatly influenced by the production of ascites, little is known about the mechanism. To investigate the effects of pancreatitis-associated ascitic fluid (PAAF) on macrophage function, we examined the effects of PAAF obtained from a rat model of severe acute pancreatitis on the ability of peritoneal macrophages to produce tumor necrosis factor-alpha (TNF-alpha). In addition, we compared the responses of PAAF-treated and PAAF-untreated macrophages to lipopolysaccharide (LPS) by evaluating their TNF-alpha production and nuclear factor-kappaB (NFkappaB) activation. Incubation of peritoneal macrophages with the PAAF led to the rapid and prolonged activation of NF-kappaB and to TNF-alpha production. Pyrrolidine dithiocarbamate, a potent inhibitor of NF-kappaB activation, attenuated the macrophage TNF-alpha production by PAAF. Macrophages produced TNF-alpha in response to LPS, but the cytokine production was significantly reduced when macrophages were pretreated with PAAF. The suppression of TNF-alpha production by PAAF pretreatment accompanied the impairment of NF-kappaB activation in response to LPS. These results indicate that the PAAF of severe acute pancreatitis may play important roles in the pathologic course of this disease through its effects on macrophage function.

  5. Determination of renal function and injury using near-infrared fluorimetry in experimental cardiorenal syndrome.

    Science.gov (United States)

    Ikeda, Mizuko; Wakasaki, Rumie; Schenning, Katie J; Swide, Thomas; Lee, Jeong Heon; Miller, M Bernie; Choi, Hak Soo; Anderson, Sharon; Hutchens, Michael P

    2017-04-01

    Cardiorenal syndrome type 1 causes acute kidney injury but is poorly understood; animal models and diagnostic aids are lacking. Robust noninvasive measurements of glomerular filtration rate are required for injury models and clinical use. Several have been described but are untested in translational models and suffer from biologic interference. We developed a mouse model of cardiorenal syndrome and tested the novel near-infrared fluorophore ZW800-1 to assess renal and cardiac function. We performed murine cardiac arrest and cardiopulmonary resuscitation followed by transthoracic echocardiography, 2 and 24 h later. Transcutaneous fluorescence of ZW800-1 bolus dispersion and clearance was assessed with whole animal imaging and compared with glomerular filtration rate (GFR; inulin clearance), tubular cell death (using unbiased stereology), and serum creatinine. Correlation, Bland-Altman, and polar analyses were used to compare GFR with ZW800-1 clearance. Cardiac arrest and cardiopulmonary resuscitation caused reversible cardiac failure, halving fractional shortening of the left ventricle (n = 12, P = 0.03). Acute kidney injury resulted with near-zero GFR and sixfold increase in serum creatinine 24 h later (n = 16, P cardiorenal syndrome type 1. ZW800-1, a small near-infrared fluorophore being developed for clinical intraoperative imaging, is favorable for evaluating cardiac and renal function noninvasively. Copyright © 2017 the American Physiological Society.

  6. Experimental insights on the function of ancillary pollen and stigma polymorphisms in plants with heteromorphic incompatibility.

    Science.gov (United States)

    Costa, Joana; Castro, Sílvia; Loureiro, João; Barrett, Spencer C H

    2017-01-01

    Most heterostylous plants possess a reciprocal arrangement of stigmas and anthers (reciprocal herkogamy), heteromorphic self-incompatibility, and ancillary polymorphisms of pollen and stigmas. The topographical complementarity hypothesis proposes that ancillary polymorphisms function in the rejection of incompatible pollen thus promoting disassortative pollination. Here, we test this hypothesis by investigating patterns of pollen transfer and capture in populations of dimorphic Armeria maritima and A. pubigera and distylous Limonium vulgare (Plumbaginaceae), and by studying pollen adherence and germination patterns in A. maritima following controlled hand-pollinations. Armeria lacks reciprocal herkogamy allowing the evaluation of the extent to which ancillary polymorphisms affect the composition of pollen loads. We compared the amounts of compatible and incompatible pollen on stigmas in natural populations and calculated the proficiencies of pollen transfer for each mating type. We detected disassortative pollination in each species, and mating types did not differ in compatible pollen capture, although cob stigmas captured more incompatible pollen. Controlled hand-pollinations revealed the failure of incompatible pollen to adhere and germinate on stigmas. Our results provided evidence that, while structural in nature, pollen-stigma dimorphisms are tightly associated with heteromorphic incompatibility and likely function to promote disassortative pollination, especially in the absence of reciprocal herkogamy. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  7. Inhibition of LINGO-1 promotes functional recovery after experimental spinal cord demyelination.

    Science.gov (United States)

    Zhang, Yongjie; Zhang, Yi Ping; Pepinsky, Blake; Huang, Guanrong; Shields, Lisa B E; Shields, Christopher B; Mi, Sha

    2015-04-01

    Blocking LINGO-1 has been shown to enhance remyelination in the rat lysolecithin-induced focal spinal cord demyelination model. We used transcranial magnetic motor-evoked potentials (tcMMEPs) to assess the effect of blocking LINGO-1 on recovery of axonal function in a mouse lysolecithin model at 1, 2 and 4weeks after injury. The role of LINGO-1 was assessed using LINGO-1 knockout (KO) mice and in wild-type mice after intraperitoneal administration of anti-LINGO-1 antagonist monoclonal antibody (mAb3B5). Response rates (at 2 and 4weeks) and amplitudes (at 4weeks) were significantly increased in LINGO-1 KO and mAb3B5-treated mice compared with matched controls. The latency of potentials at 4weeks was significantly shorter in mAb3B5-treated mice compared with controls. Lesion areas in LINGO-1 KO and mAb3B5-treated mice were reduced significantly compared with matched controls. The number of remyelinated axons within the lesions was increased and the G-ratios of the axons were decreased in both LINGO-1 KO and mAb3B5-treated mice compared with matched controls. These data provide morphometric and functional evidence of enhancement of remyelination associated with antagonism of LINGO-1. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Evaluation of wetland methyl mercury export as a function of experimental manipulations.

    Science.gov (United States)

    Gustin, Mae Sexauer; Chavan, Prithviraj V; Dennett, Keith E; Marchand, Eric A; Donaldson, Susan

    2006-01-01

    Mercury associated with natural enrichment, historic mining, and ore processing is a contaminant of concern in watersheds of the western USA. In this region, water is a highly managed resource and wetlands, known to be important sites of methyl mercury production, are often an integral component of watersheds. This study applied controlled manipulations of four replicated experimental wetland designs with different water and soil mercury concentrations to determine the potential impacts on methyl mercury export. Wetlands were manipulated by drying and wetting, changing hydraulic retention time, and adding sulfate and nitrate to influent waters. In a summer drying and wetting manipulation, an immediate increase in total methyl mercury release was observed with rewetting, however, concentrations decreased quickly. Drying all wetlands over the winter and rewetting in the spring resulted in high net methyl mercury output relative to that observed before drying. Net methyl mercury output was not influenced by changes in hydraulic retention time from 4 to 8 h or to 30 min, or by increasing the nitrate concentration from 0.1 to 10 mg L(-1). The addition of sulfate to the inlet waters of two mesocosms to increase concentrations from approximately 100 to 250 mg L(-1) did not result in a clear effect on methyl mercury output, most likely due to sulfate concentrations being higher than optimal for methyl mercury production. Despite the lack of response to sulfate amendments, the change in sulfate concentration between the inlet and outlet of the mesocosms and temperature were the parameters best correlated with methyl mercury outputs.

  9. Experimental design and multiple response optimization. Using the desirability function in analytical methods development.

    Science.gov (United States)

    Candioti, Luciana Vera; De Zan, María M; Cámara, María S; Goicoechea, Héctor C

    2014-06-01

    A review about the application of response surface methodology (RSM) when several responses have to be simultaneously optimized in the field of analytical methods development is presented. Several critical issues like response transformation, multiple response optimization and modeling with least squares and artificial neural networks are discussed. Most recent analytical applications are presented in the context of analytLaboratorio de Control de Calidad de Medicamentos (LCCM), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.C. 242, S3000ZAA Santa Fe, ArgentinaLaboratorio de Control de Calidad de Medicamentos (LCCM), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.C. 242, S3000ZAA Santa Fe, Argentinaical methods development, especially in multiple response optimization procedures using the desirability function. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Proton and deuteron induced reactions on natGa: Experimental and calculated excitation functions

    Science.gov (United States)

    Hermanne, A.; Adam-Rebeles, R.; Tárkányi, F.; Takács, S.; Ditrói, F.

    2015-09-01

    Cross-sections for reactions on natGa, induced by protons (up to 65 MeV) and deuterons (up to 50 MeV), producing γ-emitting radionuclides with half-lives longer than 1 h were measured in a stacked-foil irradiation using thin Ga-Ni alloy (70-30%) targets electroplated on Cu or Au backings. Excitation functions for generation of 68,69Ge, 66,67,68,72Ga and 65,69mZn on natGa are discussed, relative to the monitor reactions natAl(d,x)24,22Na, natAl(p,x)24,22Na, natCu(p,x)62Zn and natNi(p,x)57Ni. The results are compared to our earlier measurements, the scarce literature values and to the results of the code TALYS 1.6 (online database TENDL-2014).

  11. Confronting QCD with the experimental hadronic spectral functions from tau decay

    Science.gov (United States)

    Dominguez, C. A.; Nasrallah, N. F.; Schilcher, K.

    2009-09-01

    The (nonstrange) vector and axial-vector spectral functions extracted from τ decay by the ALEPH Collaboration are confronted with QCD in the framework of a finite energy sum rule involving a polynomial kernel tuned to suppress the region beyond the kinematical end point where there is no longer data. This effectively allows for a QCD finite energy sum rule analysis to be performed beyond the region of the existing data. Results show excellent agreement between data and perturbative QCD in the remarkably wide energy range s=3-10GeV2, leaving room for a dimension d=4 vacuum condensate consistent with values in the literature. A hypothetical dimension d=2 term in the operator product expansion is found to be extremely small, consistent with zero. Fixed order and contour improved perturbation theory are used, with both leading to similar results within errors. Full consistency is found between vector and axial-vector channel results.

  12. Experimental and density functional study of Mn doped Bi2Te3 topological insulator

    Directory of Open Access Journals (Sweden)

    A. Ghasemi

    2016-12-01

    Full Text Available We present a nanoscale structural and density functional study of the Mn doped 3D topological insulator Bi2Te3. X-ray absorption near edge structure shows that Mn has valency of nominally 2+. Extended x-ray absorption fine structure spectroscopy in combination with electron energy loss spectroscopy (EELS shows that Mn is a substitutional dopant of Bi and Te and also resides in the van der Waals gap between the quintuple layers of Bi2Te3. Combination of aberration-corrected scanning transmission electron microscopy and EELS shows that Mn substitution of Te occurs in film regions with increased Mn concentration. First-principles calculations show that the Mn dopants favor octahedral sites and are ferromagnetically coupled.

  13. Using density functional theory to increase the accuracy of experimental crystal structures: The case of potassium peroxocarbonate

    Science.gov (United States)

    Faccio, Ricardo; Saenz-Méndez, Patricia; Kieninger, Martina; Ventura, Oscar N.

    2017-10-01

    A first principles simulation of the crystal structure of potassium peroxocarbonate is presented, using density functional methods (both local and semilocal) for the calculations. An experimental crystal structure with a seemingly inconsistent disposition of the peroxide bonds was used as initial input. Both geometry optimizations of the molecular structure and optimization of the cell size were performed. While cell parameters and heavier atom positions determined at the GGA level are very close to the experimental ones, there are important discrepancies in the positioning of the hydrogen atoms. As a result of these calculations, it was shown that the assignment of the peroxydic hydrogens and the peroxydic bond in the experimental structure was incorrect. A more accurate structure is presented and geometrical as well as cell parameters described. It is also shown that LDA is not accurate enough to describe this type of ionic crystals, because of overbinding of the ions, leading to incorrect cell parameters and volume. Our methodology was validated using DFT methods with several basis sets.

  14. Experimental evidence for friction-enhancing integumentary modifications of chameleons and associated functional and evolutionary implications

    Science.gov (United States)

    Khannoon, Eraqi R.; Endlein, Thomas; Russell, Anthony P.; Autumn, Kellar

    2014-01-01

    The striking morphological convergence of hair-like integumentary derivatives of lizards and arthropods (spiders and insects) demonstrates the importance of such features for enhancing purchase on the locomotor substrate. These pilose structures are responsible for the unique tractive abilities of these groups of animals, enabling them to move with seeming ease on overhanging and inverted surfaces, and to traverse inclined smooth substrates. Three groups of lizards are well known for bearing adhesion-promoting setae on their digits: geckos, anoles and skinks. Similar features are also found on the ventral subdigital and distal caudal skin of chameleons. These have only recently been described in any detail, and structurally and functionally are much less well understood than are the setae of geckos and anoles. The seta-like structures of chameleons are not branched (a characteristic of many geckos), nor do they terminate in spatulate tips (which is characteristic of geckos, anoles and skinks). They are densely packed and have attenuated blunt, globose tips or broad, blade-like shafts that are flattened for much of their length. Using a force transducer, we tested the hypothesis that these structures enhance friction and demonstrate that the pilose skin has a greater frictional coefficient than does the smooth skin of these animals. Our results are consistent with friction being generated as a result of side contact of the integumentary filaments. We discuss the evolutionary and functional implications of these seta-like structures in comparison with those typical of other lizard groups and with the properties of seta-mimicking synthetic structures. PMID:24285195

  15. Impact of Cardiopulmonary Bypass on Respiratory Mucociliary Function in an Experimental Porcine Model.

    Directory of Open Access Journals (Sweden)

    Rodrigo Sánchez-Véliz

    Full Text Available The impact of cardiac surgery using cardiopulmonary bypass (CPB on the respiratory mucociliary function is unknown. This study evaluated the effects of CPB and interruption of mechanical ventilation on the respiratory mucociliary system.Twenty-two pigs were randomly assigned to the control (n = 10 or CPB group (n = 12. After the induction of anesthesia, a tracheostomy was performed, and tracheal tissue samples were excised (T0 from both groups. All animals underwent thoracotomy. In the CPB group, an aorto-bicaval CPB was installed and maintained for 90 minutes. During the CPB, mechanical ventilation was interrupted, and the tracheal tube was disconnected. A second tracheal tissue sample was obtained 180 minutes after the tracheostomy (T180. Mucus samples were collected from the trachea using a bronchoscope at T0, T90 and T180. Ciliary beat frequency (CBF and in situ mucociliary transport (MCT were studied in ex vivo tracheal epithelium. Mucus viscosity (MV was assessed using a cone-plate viscometer. Qualitative tracheal histological analysis was performed at T180 tissue samples.CBF decreased in the CPB group (13.1 ± 1.9 Hz vs. 11.1 ± 2.1 Hz, p < 0.05 but not in the control group (13.1 ± 1 Hz vs. 13 ± 2.9 Hz. At T90, viscosity was increased in the CPB group compared to the control (p < 0.05. No significant differences were observed in in situ MCT. Tracheal histology in the CPB group showed areas of ciliated epithelium loss, submucosal edema and infiltration of inflammatory cells.CPB acutely contributed to alterations in tracheal mucocilliary function.

  16. Functionality Evaluation of a Novel Smart Expandable Pedicle Screw to Mitigate Osteoporosis Effect in Bone Fixation: Modeling and Experimentation

    Directory of Open Access Journals (Sweden)

    Ahmadreza Eshghinejad

    2013-01-01

    Full Text Available This paper proposes a novel expandable-retractable pedicle screw and analyzes its functionality. A specially designed pedicle screw is described which has the ability to expand and retract using nitinol elements. The screw is designed to expand in body temperature and retract by cooling the screw. This expansion-retraction function is verified in an experiment designed in larger scale using a nitinol antagonistic assembly. The results of this experiment are compared to the results of a finite element model developed in Abaqus in combination with a user material subroutine (UMAT. This code has been developed to analyze the nonlinear thermomechanical behavior of shape memory alloy materials. The functionality of the proposed screw is evaluated with simulation and experimentation in a pullout test as well. The pullout force of a normal screw inserted in a normal bone was simulated, and the result is compared with the results of the expandable screw in osteoporotic bone. Lastly, strength of the designed pedicle screw in a foam block is also verified with experiment. The reported finite element simulations and experiments are the proof for the concept of nitinol expandable-retractable elements on a pedicle screw which validate the functionality in a pullout test.

  17. Stylus: a system for evolutionary experimentation based on a protein/proteome model with non-arbitrary functional constraints.

    Directory of Open Access Journals (Sweden)

    Douglas D Axe

    Full Text Available The study of protein evolution is complicated by the vast size of protein sequence space, the huge number of possible protein folds, and the extraordinary complexity of the causal relationships between protein sequence, structure, and function. Much simpler model constructs may therefore provide an attractive complement to experimental studies in this area. Lattice models, which have long been useful in studies of protein folding, have found increasing use here. However, while these models incorporate actual sequences and structures (albeit non-biological ones, they incorporate no actual functions--relying instead on largely arbitrary structural criteria as a proxy for function. In view of the central importance of function to evolution, and the impossibility of incorporating real functional constraints without real function, it is important that protein-like models be developed around real structure-function relationships. Here we describe such a model and introduce open-source software that implements it. The model is based on the structure-function relationship in written language, where structures are two-dimensional ink paths and functions are the meanings that result when these paths form legible characters. To capture something like the hierarchical complexity of protein structure, we use the traditional characters of Chinese origin. Twenty coplanar vectors, encoded by base triplets, act like amino acids in building the character forms. This vector-world model captures many aspects of real proteins, including life-size sequences, a life-size structural repertoire, a realistic genetic code, secondary, tertiary, and quaternary structure, structural domains and motifs, operon-like genetic structures, and layered functional complexity up to a level resembling bacterial genomes and proteomes. Stylus is a full-featured implementation of the vector world for Unix systems. To demonstrate the utility of Stylus, we generated a sample set of

  18. Metabolite profiles correlate closely with neurobehavioral function in experimental spinal cord injury in rats.

    Directory of Open Access Journals (Sweden)

    Yusuke Fujieda

    Full Text Available Traumatic spinal cord injury (SCI results in direct physical damage and the generation of local factors contributing to secondary pathogenesis. Untargeted metabolomic profiling was used to uncover metabolic changes and to identify relationships between metabolites and neurobehavioral functions in the spinal cord after injury in rats. In the early metabolic phase, neuronal signaling, stress, and inflammation-associated metabolites were strongly altered. A dynamic inflammatory response consisting of elevated levels of prostaglandin E2 and palmitoyl ethanolamide as well as pro- and anti-inflammatory polyunsaturated fatty acids was observed. N-acetyl-aspartyl-glutamate (NAAG and N-acetyl-aspartate (NAA were significantly decreased possibly reflecting neuronal cell death. A second metabolic phase was also seen, consistent with membrane remodeling and antioxidant defense response. These metabolomic changes were consistent with the pathology and progression of SCI. Several metabolites, including NAA, NAAG, and the ω-3 fatty acids docosapentaenoate and docosahexaenoate correlated greatly with the established Basso, Beattie and Bresnahan locomotive score (BBB score. Our findings suggest the possibility of a biochemical basis for BBB score and illustrate that metabolites may correlate with neurobehavior. In particular the NAA level in the spinal cord might provide a meaningful biomarker that could help to determine the degree of injury severity and prognosticate neurologic recovery.

  19. Lobate geometries as a function of upstream channel hydraulics: experimental results from supercritical alluvial fans

    Science.gov (United States)

    Hamilton, P.; Strom, K. B.; Hoyal, D. C.

    2012-12-01

    Channel and lobe mechanics represent the morphodynamic signature of distributive systems over intermediate time and length scales (mesoscales). Whereas the microscale (e.g., bedforms) is governed by turbulent interaction with the sediment bed and the macroscale (e.g., basin filling) is influenced by shifts in tectonic activity and climate, mesoscale mechanics are governed by non-linear morphodynamic feedbacks between the mobile sediment bed and fluid flow. As an interrelated feedback mechanism, variations in bed morphology drive changes in the fluid mechanics that are propagated solely downstream in the supercritical case. Here, a series of supercritical fan experiments were run to better understand the interaction and relationship between distributive channels and their terminal lobes. Lobe geometries are considered in terms of the maximum length, width, and thickness along with the variation of width and thickness as a function of distance down lobe. Channel hydraulics are measured using the combination of Large Scale Particle Image Velocimetry (LSPIV) for velocity and an apparent dye-intensity method for depth. Planform lobe dimensions are measured from overhead images and thicknesses are measured from a terrestrial LiDAR unit. From the collected data, lobe geometries are correlated to the upstream distributive channel hydraulics to better understand the autogenic morphodynamic feedback cycle.; lobe dimensions measured from autogenic cylces

  20. EXPERIMENTAL DETERMINATION OF CONTAMINANT METAL MOBILITY AS A FUNCTION OF TEMPERATURE, TIME, AND SOLUTION CHEMISTRY

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Susan A.; O' Day, Peggy A.

    1999-12-31

    During the FY96-FY99 funding cycle we examined the uptake of aqueous strontium onto goethite, kaolinite, and amorphous silica surfaces as a function of pH, total strontium, and temperature. Our overall goal was to produce a mechanistic sorption model that can be used in reaction-transport calculations to predict the mobility and attenuation of radioactive strontium (90Sr) in the environment. Our approach was to combine structural information derived from synchrotron-based x-ray absorption spectroscopic analysis together with macroscopic uptake data and surface complexation models to clarify the physical and chemical structure of sorbed complexes. We chose to study these solids because of the prevalence of clays and iron hydroxides in natural systems, and because silica colloids probably form beneath leaking tanks at Hanford as caustic waste is neutralized. We have published the spectroscopic work in two papers in the Journal of Colloid and Interface Science [1, 2], and will soon submit at third manuscript to Geochemical Transactions [3] combining the sorption and spectroscopic data with a mechanistic complexation model.

  1. [The outlook for the experimental study of the network functions of cortical cells during learning].

    Science.gov (United States)

    Gasanov, U G

    1992-01-01

    The main outcome of the experiments described in the paper is an idea on the gnostic cortical microset. Multineuronal activity recorded from the motor cortex of cats with a conditioned response to time and the following cross-correlation analysis revealed a strict distribution of interneuronal connections within the microsystems (between the adjacent neurons) and variable connections between the remote neurons during the active waiting stage of two minute interval. Additional analysis of the narrow (0.5 ms) peaks of the histograms allowed to form a view on the synaptic interaction in time. It was found that there was different temporal distribution of the spikes in the peak obtained due to correlograms of neuronal pairs. Some cortical neurons demonstrated a visible synaptic activation at the end of the waiting period when other signs of the temporary behaviour were absent. Pharmacological testing functional interneuronal connections with acetylcholine and Ca(2+)-suppressing drug EGTA have raised a question on the neurochemical specificity of the intra- and extracortical synapses.

  2. Functional MMP-10 is required for efficient tissue repair after experimental hind limb ischemia.

    Science.gov (United States)

    Gomez-Rodriguez, Violeta; Orbe, Josune; Martinez-Aguilar, Esther; Rodriguez, Jose A; Fernandez-Alonso, Leopoldo; Serneels, Jens; Bobadilla, Miriam; Perez-Ruiz, Ana; Collantes, Maria; Mazzone, Massimiliano; Paramo, Jose A; Roncal, Carmen

    2015-03-01

    We studied the role of matrix metalloproteinase-10 (MMP-10) during skeletal muscle repair after ischemia using a model of femoral artery excision in wild-type (WT) and MMP-10 deficient (Mmp10(-/-)) mice. Functional changes were analyzed by small animal positron emission tomography and tissue morphology by immunohistochemistry. Gene expression and protein analysis were used to study the molecular mechanisms governed by MMP-10 in hypoxia. Early after ischemia, MMP-10 deficiency resulted in delayed tissue reperfusion (10%, P < 0.01) and in increased necrosis (2-fold, P < 0.01), neutrophil (4-fold, P < 0.01), and macrophage (1.5-fold, P < 0.01) infiltration. These differences at early time points resulted in delayed myotube regeneration in Mmp10(-/-) soleus at later stages (regenerating myofibers: 30 ± 9% WT vs. 68 ± 10% Mmp10(-/-), P < 0.01). The injection of MMP-10 into Mmp10(-/-) mice rescued the observed phenotype. A molecular analysis revealed higher levels of Cxcl1 mRNA (10-fold, P < 0.05) and protein (30%) in the ischemic Mmp10(-/-) muscle resulting from a lack of transcriptional inhibition by MMP-10. This was further confirmed using siRNA against MMP-10 in vivo. Our results demonstrate an important role of MMP-10 for proper muscle repair after ischemia, and suggest that chemokine regulation such as Cxcl1 by MMP-10 is involved in muscle regeneration. © FASEB.

  3. Proton and deuteron induced reactions on {sup nat}Ga: Experimental and calculated excitation functions

    Energy Technology Data Exchange (ETDEWEB)

    Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Adam-Rebeles, R. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Tárkányi, F.; Takács, S.; Ditrói, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (Atomki), Debrecen (Hungary)

    2015-09-15

    Cross-sections for reactions on {sup nat}Ga, induced by protons (up to 65 MeV) and deuterons (up to 50 MeV), producing γ-emitting radionuclides with half-lives longer than 1 h were measured in a stacked-foil irradiation using thin Ga–Ni alloy (70–30%) targets electroplated on Cu or Au backings. Excitation functions for generation of {sup 68,69}Ge, {sup 66,67,68,72}Ga and {sup 65,69m}Zn on {sup nat}Ga are discussed, relative to the monitor reactions {sup nat}Al(d,x){sup 24,22}Na, {sup nat}Al(p,x){sup 24,22}Na, {sup nat}Cu(p,x){sup 62}Zn and {sup nat}Ni(p,x){sup 57}Ni. The results are compared to our earlier measurements, the scarce literature values and to the results of the code TALYS 1.6 (online database TENDL-2014)

  4. Minimally invasive neurosurgery with interventional magnetic resonance. Its present and future

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Takuo [Jikei Univ., Tokyo (Japan). School of Medicine

    2000-01-01

    We have used X-ray fluoroscopy, ultrasonography, and computed tomography in treatment. However, these methods do not provide precise image. Since magnetic resonance (MR) provides high-resolution images, it is more suitable in treatment. Recently open-type MR has been introduced for clinical diagnosis and treatment. Interventional MR provides a real-time images, high-resolutional images, and thermal distribution. Open MR can be used for minimally invasive neurosurgery. Interventional MR (I-MR) can be used in treatment and is extremely useful for minimally invasive surgery of the brain and spinal cord. We have used an open-type permanent MR scanner (Airis, Hitachi), for minimally invasive neurosurgery. Stereotactic brain tumor biopsy, aspiration of intracerebral hematoma, and percutaneous laser disc hernia ablation under MR guidance has been performed in our department. I-MR provided precise, and less-invasive treatment. Stereotactic biopsy was done in 12 patients with brain tumors. Precise, accurate biopsy is possible with MR fluoroscopic guidance. Hematomas were also aspirated safely and precisely by monitoring real-time image. Percutaneous laser disc hernia ablation (PLDA) was done in 201 patients with lumbar disc herniation (127 at L4/5 and 48 at L5/S1). Patients ranged in age from 17 to 72 years. A MR-compatible 18-gauge 15-cm-long titanium needle was clearly visualized and safety and accurately inserted into the disc herniation from multiple directions. Laser ablation was done (mean, 1,000 J). Signs and symptoms improved immediately after ablation. The overall success rate was 90.5% (MacNab's criteria). Two patients (1.0%) had discitis after PLDA. I-MR and fluoroscopy provide near-real-time images for treatment of brain tumors and hematoma. Precise treatment can be performed with the Patil MR-compatible stereotactic system. PLDA was performed safety and accurately with I-MR. The results were satisfactory. I-MR-PLDA is a safe, precise, and minimally

  5. Parental Evaluation of a Nurse Practitioner-Developed Pediatric Neurosurgery Website

    Science.gov (United States)

    Vogel, Tina Kovacs; Kleib, Manal; Davidson, Sandra J

    2016-01-01

    Background Parents often turn to the Internet to seek health information about their child’s diagnosis and condition. Information, support, and resources regarding pediatric neurosurgery are scarce, hard to find, and difficult to comprehend. To address this gap, a pediatric nurse practitioner designed a website called the Neurosurgery Kids Fund (NKF). Analyzing the legitimacy of the NKF website for parents seeking health information and fulfilling their social and resource needs is critical to the website’s future development and success. Objective To explore parental usage of the NKF website, track visitor behavior, evaluate usability and design, establish ways to improve user experience, and identify ways to redesign the website. The aim of this study was to assess and evaluate whether a custom-designed health website could meet parents’ health information, support, and resource needs. Methods A multimethod approach was used. Google Analytic usage reports were collected and analyzed for the period of April 23, 2013, to November 30, 2013. Fifty-two online questionnaires that targeted the website’s usability were collected between June 18, 2014, and July 30, 2014. Finally, a focus group was conducted on August 20, 2014, to explore parents’ perceptions and user experiences. Findings were analyzed using an inductive content analysis approach. Results There were a total of 2998 sessions and 8818 page views, with 2.94 pages viewed per session, a 56.20% bounce rate, an average session duration of 2 minutes 24 seconds, and a 56.24% new sessions rate. Results from 52 eligible surveys included that the majority of NKF users were Caucasian (90%), females (92%), aged 36-45 years (48%), with a university or college degree or diploma (69%). Half plan to use the health information. Over half reported turning to the Internet for health information and spending 2 to 4 hours a day online. The most common reasons for using the NKF website were to (1) gather information

  6. Health impact and economic analysis of NGO-supported neurosurgery in Bolivia.

    Science.gov (United States)

    Ament, Jared D; Greene, Kevin R; Flores, Ivan; Capobianco, Fernando; Salas, Gueider; Uriona, Maria Ines; Weaver, John P; Moser, Richard

    2014-04-01

    Bolivia, one of the poorest countries in the world, ranks 108th on the 2013 Human Development Index. With approximately 1 neurosurgeon per 200,000 people, access to neurosurgery in Bolivia is a growing health concern. Furthermore, neurosurgery in nonindustrialized countries has been considered both cost-prohibitive and lacking in outcomes evaluation. A non-governmental organization (NGO) supports spinal procedures in Bolivia (Solidarity Bridge), and the authors sought to determine its impact and cost-effectiveness. In a retrospective review of prospectively collected data, 19 patients were identified prior to spinal instrumentation and followed over 12 months. For inclusion, patients required interviewing prior to surgery and during at least 2 follow-up visits. All causes of spinal pathology were included. Sixteen patients met inclusion criteria and were therefore part of the analysis. Outcomes measured included assessment of activities of daily living, pain, ambulation, return to work/school, and satisfaction. Cost-effectiveness was determined by cost-utility analysis. Utilities were derived using the Health Utilities Index. Complications were incorporated into an expected value decision tree. Median (± SD) preoperative satisfaction was 2.0 ± 0.3 (on a scale of 0-10), while 6-month postoperative satisfaction was 7 ± 1.4 (p Bolivia appears to be cost-effective, especially when compared with the conventional $50,000/QALY benchmark and the WHO endorsed country-specific threshold of $16,026/QALY. However, with a gross domestic product per capita in Bolivia equaling $4800 per year and 30.3% of the population living on less than $2 per day, this cost continues to appear unrealistic. Additionally, the study has several significant limitations, namely its limited sample size, follow-up period, the assumption that patients not receiving surgical intervention would not make any clinical improvement, the reliance on the NGO for patient selection and sustainable practices

  7. Functional characterization of a dehydrin protein from Fagus sylvatica seeds using experimental and in silico approaches.

    Science.gov (United States)

    Kalemba, Ewa Marzena; Litkowiec, Monika

    2015-12-01

    A strong increase in the level of dehydrin/response ABA transcripts expression reported from the 14th week after flowering coincident with the accumulation of 26 and 44 kDa dehydrins in the embryonic axes of developing beech (Fagus sylvatica L.) seeds. Both transcript and protein levels were strongly correlated with maturation drying. These results suggest that the 44-kDa dehydrin protein is a putative dimer of dehydrin/response ABA protein migrating as a 26-kDa protein. Dehydrins and dehydrin-like proteins form large oligomeric complexes under native conditions and are shown as several spots differing in pI through isoelectrofocusing analyses. Detailed prediction of specific sites accessible for various post-translational modifications (PTMs) in the dehydrin/response ABA protein sequence revealed sites specific to acetylation, amidation, glycosylation, methylation, myristoylation, nitrosylation, O-linked β-N-acetylglucosamination and Yin-O-Yang modification, palmitoylation, phosphorylation, sumoylation, sulfation, and ubiquitination. Thus, these results suggest that specific PTMs might play a role in switching dehydrin function or activity, water binding ability, protein-membrane interactions, transport and subcellular localization, interactions with targeted molecules, and protein stability. Despite the ability of two Cys residues to form a disulfide bond, -SH groups are likely not involved in dimer arrangement. His-rich regions and/or polyQ-tracts are potential candidates as spatial organization modulators. Dehydrin/response ABA protein is an intrinsically disordered protein containing low complexity regions. The lack of a fixed structure and exposition of amino acids on the surface of the protein structure enhances the accessibility to 40 predicted PTM sites, thereby facilitating dehydrin multifunctionality, which is discussed in the present study. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Structural and functional aspects of trypsin–gold nanoparticle interactions: An experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Nidhin, Marimuthu [Department of Chemistry, Amity School of Applied Sciences, Center for Nanoscience and Technology, Amity University Haryana Amity Education Valley, Gurgaon, Haryana 122413 (India); Ghosh, Debasree [Department of Nanotechnology, Amity School of Applied Sciences, Center for Nanoscience and Technology, Amity University Haryana Amity Education Valley, Gurgaon, Haryana 122413 (India); Yadav, Himanshu; Yadav, Nitu [Department of Chemistry, Amity School of Applied Sciences, Center for Nanoscience and Technology, Amity University Haryana Amity Education Valley, Gurgaon, Haryana 122413 (India); Majumder, Sudip, E-mail: sudip22m@gmail.com [Department of Chemistry, Amity School of Applied Sciences, Center for Nanoscience and Technology, Amity University Haryana Amity Education Valley, Gurgaon, Haryana 122413 (India)

    2015-12-15

    Highlights: • Trypsin undergoes activation on incubation with gold nanoparticles. • Enhanced activity depends on the stoichiometry of the mixture. • Higher concentration of nanoparticles damage stability and conformation of trypsin. • Gold nanoparticles undergo morphological change on incubation with trypsin. - Abstract: Trypsin (Trp) is arguably the most important member of the serine proteases. Constructs made up of gold nanoparticles (GNP) with trypsin have been known to exhibit increased efficiency and stability in various experiments. Here we report simple Trp–GNP constructs mixed in different trypsin-to-GNP ratios which exhibit higher efficiencies in biochemical assay, varying resistance to autolysis and higher ability in cell trypsinization. Trp–GNP constructs in different trypsin-to-GNP ratios exhibit prolonged and sustained activity compared to native trypsin in N-α-p-benzoyl-p-nitroanilide (BAPNA) assay as monitored by UV-Visible spectroscopy. The activity was monitored as a function of decreasing rate of linear release of p-nitro aniline (resulting from the cleavage of BAPNA by trypsin) with time during the assay, whose absorbance was measured at 410 nm (λ{sub max} p-nitro aniline). We have done extensive studies to understand structural basis of this trypsin GNP interaction by using atomic force microscopy (AFM), transmission electron microscopy (TEM) and circular dichroism (CD) techniques. Our findings suggest that on interaction, the gold nanoparticles probably form an adherent layer on trypsin that effectively changes the morphology and dimensions of the nanoconstructs. However, trypsin-to-GNP ratio is extremely important, as higher concentration of GNP might damage the conformation of protein. Stability studies related to denaturation show that 1:1 Trp–GNP constructs exhibit maximum stability and high efficiency in all assays performed.

  9. Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury.

    Science.gov (United States)

    West, Christopher R; Crawford, Mark A; Poormasjedi-Meibod, Malihe-Sadat; Currie, Katharine D; Fallavollita, Andre; Yuen, Violet; McNeill, John H; Krassioukov, Andrei V

    2014-04-15

    Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day(-1), 5 days week(-1) for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFβ1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFβ1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI.

  10. Prenatal intestinal obstruction affects the myenteric plexus and causes functional bowel impairment in fetal rat experimental model of intestinal atresia.

    Directory of Open Access Journals (Sweden)

    Naziha Khen-Dunlop

    Full Text Available BACKGROUND: Intestinal atresia is a rare congenital disorder with an incidence of 3/10,000 birth. About one-third of patients have severe intestinal dysfunction after surgical repair. We examined whether prenatal gastrointestinal obstruction might effect on the myenteric plexus and account for subsequent functional disorders. METHODOLOGY/PRINCIPAL FINDINGS: We studied a rat model of surgically induced antenatal atresia, comparing intestinal samples from both sides of the obstruction and with healthy rat pups controls. Whole-mount preparations of the myenteric plexus were stained for choline acetyltransferase (ChAT and nitric oxide synthase (nNOS. Quantitative reverse transcription PCR was used to analyze mRNAs for inflammatory markers. Functional motility and permeability analyses were performed in vitro. Phenotypic studies were also performed in 8 newborns with intestinal atresia. In the experimental model, the proportion of nNOS-immunoreactive neurons was similar in proximal and distal segments (6.7±4.6% vs 5.6±4.2%, p = 0.25, but proximal segments contained a higher proportion of ChAT-immunoreactive neurons (13.2±6.2% vs 7.5±4.3%, p = 0.005. Phenotypic changes were associated with a 100-fold lower concentration-dependent contractile response to carbachol and a 1.6-fold higher EFS-induced contractile response in proximal compared to distal segments. Transcellular (p = 0.002 but not paracellular permeability was increased. Comparison with controls showed that modifications involved not only proximal but also distal segments. Phenotypic studies in human atresia confirmed the changes in ChAT expression. CONCLUSION: Experimental atresia in fetal rat induces differential myenteric plexus phenotypical as well as functional changes (motility and permeability between the two sides of the obstruction. Delineating these changes might help to identify markers predictive of motility dysfunction and to define guidelines for post

  11. Experimental analyses of the function of the proepicardium using a new microsurgical procedure to induce loss-of-proepicardial-function in chick embryos.

    Science.gov (United States)

    Männer, Jörg; Schlueter, Jan; Brand, Thomas

    2005-08-01

    The proepicardium (PE) is a primarily extracardiac progenitor cell population that colonizes the embryonic heart and delivers the epicardium, the subepicardial and intramyocardial fibroblasts, and the coronary vessels. Recent data show that PE-derived cells additionally play important regulatory roles in myocardial development and possibly in the normal morphogenesis of the heart. Developmental Dynamics 233, 2005. Research on the latter topics profits from the fact that loss-of-PE-function can be experimentally induced in chick embryos. So far, two microsurgical techniques were used to produce such embryos: (1) blocking of PE cell transfer with pieces of the eggshell membrane, and (2) mechanical excision of PE. Both of these techniques, however, have their shortcomings. We have searched, therefore, for new techniques to eliminate the PE. Here, we show that loss-of-PE-function can be induced by photoablation of the PE. Chick embryos were treated in ovo by means of a window in the eggshell at Hamburger and Hamilton (HH) stage 16 (iday 3). The pericardial coelom was opened, and the PE was externally stained with a 1% solution of Rose Bengal by means of a micropipette. Photoactivation of the dye was accomplished by illumination of the operation field with visible light. Examination on postoperative day 1 (iday 4, HH stages 19/20) disclosed complete removal of PE in every experimental embryo. On iday 9 (HH stages 33/34), the survival rate of experimental embryos was 35.7% (15 of 42). Development of the PE-derivatives was compromised in the heart of every survivor. The abnormalities encompassed hydro- or hemopericardium, epicardium-free areas with aneurysmatic outward bulging of the ventricular wall, thin myocardium, defects of the coronary vasculature, and abnormal tissue bridges between the ventricles and the pericardial wall. Our results show that photoablation of the PE is a powerful technique to induce long-lasting loss-of-PE-function in chick embryos. We have

  12. [Experimental studies on the question of an adjuvant function of bromhexine].

    Science.gov (United States)

    GOtz, V H

    1975-04-01

    On a possible adjuvant function of a bronchosecretolytic preparation commercially available, N-cyclohexyl-N-methyl-(2-amino-3,5-dibromobenzyl)-amine-hydrochloride (bromhexine, Bisolvon-R), sensibilization tests on 30 rabbits were undertaken. 5 animals received Bisolvon and human albumin as antigen, 5 rabbits human albumin only, 5 rabbits Bisolvon and human lymphocytes, 5 rabbits human lymphocytes only, 5 rabbits Bisolvon alone, and 5 received neither Bisolvon nor any antigen. The techniques in these studies, such as two-dimensional double immunodiffusion in agar gel, lymphocytotoxicity test, mixed lymphocyte culture test, electrophoresis on cellulose-acetate foil were used as well as histologic preparations. It could be ascertained that sensitizing with human albumin and simultaneous application of Bisolvon led to a higher concentration of antibodies against albumin than did sensitizing with human albumin alone. Rabbits sensitized with human lymphocytes showed no obvious difference in their antibody rates whether they had received Bisolvon or not. This applied to cell mediated antibodies as well as to the rate of cytotoxic antibodies against human lymphocytes. Among the histologic findings of spleen, bone marrow showed the morphologic equivalences expected from xenosensitization. Comparing the results of sensitized rabbits with and without Bisolvon there were no positive differences as to intensity and/or type of reactivity to be seen. Liver and kidney showed no considerable pathologic phenomena with the exception of some cases with coccidiosis in the bile ductuli. Concerning the bronchial mucosa, in all rabbits treated with Bisolvon an increase of mucine enriched goblet cells as well as a hypergranulation of different epithelial cell types could be observed. Moreover in all animals, including the controls, an intense lymphatic infilitration in the subepithelial and submucous area was identified. The increased antibody concentration in the sera of animals from

  13. Variability in Tidal Volume Affects Lung and Cardiovascular Function Differentially in a Rat Model of Experimental Emphysema

    Directory of Open Access Journals (Sweden)

    Caio G. R. S. Wierzchon

    2017-12-01

    Full Text Available In experimental elastase-induced emphysema, mechanical ventilation with variable tidal volumes (VT set to 30% coefficient of variation (CV may result in more homogenous ventilation distribution, but might also impair right heart function. We hypothesized that a different CV setting could improve both lung and cardiovascular function. Therefore, we investigated the effects of different levels of VT variability on cardiorespiratory function, lung histology, and gene expression of biomarkers associated with inflammation, fibrogenesis, epithelial cell damage, and mechanical cell stress in this emphysema model. Wistar rats (n = 35 received repeated intratracheal instillation of porcine pancreatic elastase to induce emphysema. Seven animals were not ventilated and served as controls (NV. Twenty-eight animals were anesthetized and assigned to mechanical ventilation with a VT CV of 0% (BASELINE. After data collection, animals (n = 7/group were randomly allocated to VT CVs of 0% (VV0; 15% (VV15; 22.5% (VV22.5; or 30% (VV30. In all groups, mean VT was 6 mL/kg and positive end-expiratory pressure was 3 cmH2O. Respiratory system mechanics and cardiac function (by echocardiography were assessed continuously for 2 h (END. Lung histology and molecular biology were measured post-mortem. VV22.5 and VV30 decreased respiratory system elastance, while VV15 had no effect. VV0, VV15, and VV22.5, but not VV30, increased pulmonary acceleration time to pulmonary ejection time ratio. VV22.5 decreased the central moment of the mean linear intercept (D2 of Lm while increasing the homogeneity index (1/β compared to NV (77 ± 8 μm vs. 152 ± 45 μm; 0.85 ± 0.06 vs. 0.66 ± 0.13, p < 0.05 for both. Compared to NV, VV30 was associated with higher interleukin-6 expression. Cytokine-induced neutrophil chemoattractant-1 expression was higher in all groups, except VV22.5, compared to NV. IL-1β expression was lower in VV22.5 and VV30 compared to VV0. IL-10 expression was higher

  14. Genetic Linkage of Soil Carbon Pools and Microbial Functions in Subtropical Freshwater Wetlands in Response to Experimental Warming

    Science.gov (United States)

    Wang, Hang; He, Zhili; Lu, Zhenmei; Zhou, Jizhong; Van Nostrand, Joy D.; Xu, Xinhua

    2012-01-01

    Rising climate temperatures in the future are predicted to accelerate the microbial decomposition of soil organic matter. A field microcosm experiment was carried out to examine the impact of soil warming in freshwater wetlands on different organic carbon (C) pools and associated microbial functional responses. GeoChip 4.0, a functional gene microarray, was used to determine microbial gene diversity and functional potential for C degradation. Experimental warming significantly increased soil pore water dissolved organic C and phosphorus (P) concentrations, leading to a higher potential for C emission and P export. Such losses of total organic C stored in soil could be traced back to the decomposition of recalcitrant organic C. Warming preferentially stimulated genes for degrading recalcitrant C over labile C. This was especially true for genes encoding cellobiase and mnp for cellulose and lignin degradation, respectively. We confirmed this with warming-enhanced polyphenol oxidase and peroxidase activities for recalcitrant C acquisition and greater increases in recalcitrant C use efficiency than in labile C use efficiency (average percentage increases of 48% versus 28%, respectively). The relative abundance of lignin-degrading genes increased by 15% under warming; meanwhile, soil fungi, as the primary decomposers of lignin, were greater in abundance by 27%. This work suggests that future warming may enhance the potential for accelerated fungal decomposition of lignin-like compounds, leading to greater microbially mediated C losses than previously estimated in freshwater wetlands. PMID:22923398

  15. Fusion imaging for intra-operative ultrasound-based navigation in neurosurgery.

    Science.gov (United States)

    Prada, Francesco; Del Bene, Massimiliano; Mattei, Luca; Casali, Cecilia; Filippini, Assunta; Legnani, Federico; Mangraviti, Antonella; Saladino, Andrea; Perin, Alessandro; Richetta, Carla; Vetrano, Ignazio; Moiraghi, Alessandro; Saini, Marco; DiMeco, Francesco

    2014-09-01

    The major shortcoming of image-guided navigation systems is the use of presurgically acquired image data, which does not account for intra-operative changes such as brain shift, tissue deformation and tissue removal occurring during the surgical procedure. Intra-operative ultrasound (iUS) is becoming widely used in neurosurgery but they lack orientation and panoramic view. In this article, we describe our procedure for US-based real-time neuro-navigation during surgery. We used fusion imaging between preoperative magnetic resonance imaging (MRI) and iUS for brain lesion removal in 67 patients so far. Surgical planning is based on preoperative MRI only. iUS images obtained during surgery are fused with the preoperative MRI. Surgery is performed under intra-operative US control. Relying on US imaging, it is possible to recalibrate navigated MRI imaging, adjusting distortion due to brain shift and tissue resection, continuously updating the two modalities. Ultrasound imaging provides excellent visualization of targets, their margins and surrounding structures. The use of navigated MRI is helpful in better understanding cerebral ultrasound images, providing orientation and panoramic view. Intraoperative US-guided neuro-navigation adjustments are very accurate and helpful in the event of brain shift. The use of this integrated system allows for a true real-time feedback during surgery.

  16. Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.

    Science.gov (United States)

    Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L

    2015-06-01

    Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.

  17. Santiago Ramón y Cajal and Harvey Cushing: two forefathers of neuroscience and neurosurgery.

    Science.gov (United States)

    Zamora-Berridi, Grettel J; Pendleton, Courtney; Ruiz, Gabriel; Cohen-Gadol, Aaron A; Quiñones-Hinojosa, Alfredo

    2011-11-01

    To summarize the extraordinary accomplishments, and the commonalities, between Santiago Ramon y Cajal and Harvey Williams Cushing. Existing literature describing the lives and achievements of Ramón y Cajal and Cushing, as well as personal communication, and the surgical records of the Johns Hopkins Hospital, from 1896 to 1912, were reviewed. Both Ramón y Cajal and Cushing were men of unusually broad interests and talents, and these shared characteristics undoubtedly influenced the career paths and scientific investigations they pursued. Although Santiago Ramón y Cajal and Harvey Williams Cushing never directly interacted, the links between them can be traced through some of their disciples, including Pío del Río Hortega, Wilder Penfield, and Percival Bailey. Ramón y Cajal and Cushing are widely considered the forefathers of neuroscience and neurosurgery, respectively, and their discoveries have made lasting impressions on both the scientific and medical communities. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. [Medico-economic analysis of a neurosurgery department at a university hospital].

    Science.gov (United States)

    Lemaire, J-J; Delom, C; Coste, A; Khalil, T; Jourdy, J-C; Pontier, B; Gabrillargues, J; Sinardet, D; Chabanne, A; Achim, V; Sakka, L; Coste, J; Chazal, J; Salagnac, A; Coll, G; Irthum, B

    2015-02-01

    Economic and societal constraints require to take into account the economic dimension and medical performance of hospital departments. We carried out a self-assessment study, which we thought could be useful to share with the neurosurgical community. Care and research activities were assessed from 2009 to 2013. We used institutional and assessment-body parameters in order to describe activities and perform a financial evaluation. It was a retrospective descriptive study based on the guidelines of the DHOS/O4 circular No. 2007/390 of October 29, 2007. The average annual, analytic income statement was +1.39 millions euros, for 63 beds with a 92% occupancy rate, including 6.7 full-time equivalent neurosurgeons (and assistants), for 2553 patients and 1975 surgeries. The average mortality rate was 2.74%. The annual mean length of stay was 6.82 days. Per year, on average 15.6% of patients were admitted in emergency and 76.9% returned home. The annual, act-related-pricing and publication-related incomes represented 77% and 0.6%, respectively of the total funding. Difficulties to find downstream beds for the most severe patients induced 1401 "waiting days" in 2012. Medico-economic analysis of a neurosurgery department at a university hospital was useful in order to take into account the care, teaching and research activities, as well as its related financial value. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Augmented virtuality based on stereoscopic reconstruction in multimodal image-guided neurosurgery: methods and performance evaluation.

    Science.gov (United States)

    Paul, Perrine; Fleig, Oliver; Jannin, Pierre

    2005-11-01

    Displaying anatomical and physiological information derived from preoperative medical images in the operating room is critical in image-guided neurosurgery. This paper presents a new approach referred to as augmented virtuality (AV) for displaying intraoperative views of the operative field over three-dimensional (3-D) multimodal preoperative images onto an external screen during surgery. A calibrated stereovision system was set up between the surgical microscope and the binocular tubes. Three-dimensional surface meshes of the operative field were then generated using stereopsis. These reconstructed 3-D surface meshes were directly displayed without any additional geometrical transform over preoperative images of the patient in the physical space. Performance evaluation was achieved using a physical skull phantom. Accuracy of the reconstruction method itself was shown to be within 1 mm (median: 0.76 mm +/- 0.27), whereas accuracy of the overall approach was shown to be within 3 mm (median: 2.29 mm +/- 0.59), including the image-to-physical space registration error. We report the results of six surgical cases where AV was used in conjunction with augmented reality. AV not only enabled vision beyond the cortical surface but also gave an overview of the surgical area. This approach facilitated understanding of the spatial relationship between the operative field and the preoperative multimodal 3-D images of the patient.

  20. Trajectory planning method for reduced patient risk in image-guided neurosurgery: concept and preliminary results

    Science.gov (United States)

    Shamir, Reuben R.; Joskowicz, Leo; Antiga, Luca; Foroni, Roberto I.; Shoshan, Yigal

    2010-02-01

    We present a new preoperative planning method to quantify and help reduce the risk associated with needle and tool insertion trajectories in image-guided keyhole neurosurgery. The goal is to quantify the risk of a proposed straight trajectory, and/or to find the trajectory with the lowest risk to nearby brain structures based on pre-operative CT/MRI images. The method automatically computes the risk associated with a given trajectory, or finds the trajectory with the lowest risk to nearby brain structures based on preoperative image segmentation and on a risk volume map. The surgeon can revise the suggested trajectory, add a new one using interactive 3D visualization, and obtain a quantitative risk measure. The trajectory risk is evaluated based on the tool placement uncertainty, on the proximity of critical brain structures, and on a predefined table of quantitative geometric risk measures. Our preliminary results on a clinical dataset with eight targets show a significant reduction in trajectory risk and a shortening of the preoperative planning time as compared to the conventional method.

  1. Towards estimating fiducial localization error of point-based registration in image-guided neurosurgery.

    Science.gov (United States)

    Zhi, Deng

    2015-01-01

    Fiducial Localization Error (FLE) is one of the major reasons of inaccuracy in point-based spatial registration of Image-Guided Neurosurgery System (IGNS), and minimizing FLE is the fundamental way to improve spatial registration accuracy. A reliable estimation of FLE is needed, as it cannot be measured directly in real application of IGNS. In this paper, we propose a method to estimate the FLE in a point-based registration of IGNS. Test fiducial point sets were generated in one coordinate system around the given fiducial point set by utilizing simple random sampling. Further, these points were registered to the fiducial point set in the other coordinate system. The average position of the test fiducial point sets with small FRE are calculated and its displacement from the given fiducial point set is the parameter used to estimate the FLE of each fiducial point. The correlation between the displacement and the FLE of each fiducial point is greater than 0.75 when nine or more fiducial points were utilized. This correlation gradually increases up to 0.9 with the increase of the number of fiducial points.

  2. Center of excellence in research reporting in neurosurgery--diagnostic ontology.

    Directory of Open Access Journals (Sweden)

    Amrapali Zaveri

    Full Text Available MOTIVATION: Evidence-based medicine (EBM, in the field of neurosurgery, relies on diagnostic studies since Randomized Controlled Trials (RCTs are uncommon. However, diagnostic study reporting is less standardized which increases the difficulty in reliably aggregating results. Although there have been several initiatives to standardize reporting, they have shown to be sub-optimal. Additionally, there is no central repository for storing and retrieving related articles. RESULTS: In our approach we formulate a computational diagnostic ontology containing 91 elements, including classes and sub-classes, which are required to conduct Systematic Reviews-Meta Analysis (SR-MA for diagnostic studies, which will assist in standardized reporting of diagnostic articles. SR-MA are studies that aggregate several studies to come to one conclusion for a particular research question. We also report high percentage of agreement among five observers as a result of the interobserver agreement test that we conducted among them to annotate 13 articles using the diagnostic ontology. Moreover, we extend our existing repository CERR-N to include diagnostic studies. AVAILABILITY: The ontology is available for download as an.owl file at: http://bioportal.bioontology.org/ontologies/3013.

  3. A retrospective case series of computer-controlled total intravenous anaesthesia in dogs presented for neurosurgery

    Directory of Open Access Journals (Sweden)

    K.E. Joubert

    2004-06-01

    Full Text Available This article describes the anaesthetic management and use of total intravenous anaesthesia (TIVA for neurosurgery in 4 dogs. Propofol in conjunction with morphine was used for the maintenance of anaesthesia. Anaesthesia was induced with either thiopentone or propofol. The program Stelpump (a target-controlled infusion program was run on a laptop and connected to a syringe driver via an RS 232 cable. The program was found to be reliable and safe for the administration of TIVA in dogs. Invasive monitoring was required in order to monitor cardiovascular changes during surgery. Ventilation was controlled to maintain the end-tidal carbon dioxide below 40 mm Hg. The anaesthesia was characterised by haemodynamic stability. The haemodynamic stability was probably the result of the choice of TIVA and balanced anaesthesia. Intracranial pressure and oedema was controlled with dexamethasone, mannitol and ventilatory management either in combination or alone. Three dogs survived to hospital discharge and 1 dog was euthanased 2 weeks later due to tumour metastasis. The development and characterisation of the anaesthetic effects of TIVA needs to be elucidated in order to provide clinicians with rational guidelines for the appropriate use of TIVA in veterinary medicine.

  4. Neurosurgery and Telemedicine in the United States: Assessment of the Risks and Opportunities.

    Science.gov (United States)

    Kahn, Elyne N; La Marca, Frank; Mazzola, Catherine A

    2016-05-01

    Telemedicine has seen substantial growth in the past 20 years, related to technologic advancements and evolving reimbursement policies. The risks and opportunities of neurosurgical telemedicine are nuanced. We reviewed general and peer-reviewed literature as it relates to telemedicine and neurosurgery, with particular attention to best practices, relevant state and federal policy conditions, economic evaluations, and prospective clinical studies. Despite technologic development, growing interest, and increasing reimbursement opportunities, telemedicine's utilization remains limited because of concerns regarding an apparent lack of need for telemedicine services, lack of widespread reimbursement, lack of interstate licensure reciprocity, lack of universal access to necessary technology, concerns about maintaining patient confidentiality, and concerns and limited precedent regarding liability issues. The Veterans Health Administration, a component of the U.S. Department of Veterans Affairs, represents a setting in which these concerns can be largely obviated and is a model for telemedicine best practices. Results from the VA demonstrate substantial cost savings and patient satisfaction with remote care for chronic neurologic conditions. Overall, the economic and clinical benefits of telemedicine will likely come from 1) diminished travel times and lost work time for patients; 2) remote consultation of subspecialty experts, such as neurosurgeons; and 3) remote consultation to assist with triage and care in time-sensitive scenarios, including acute stroke care and "teletrauma." Telemedicine is effective in many health care scenarios and will become more relevant to neurosurgical patient care. We favor proceeding with legislation to reduce barriers to telemedicine's growth. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. "Extremely minimally invasive": recent advances in nanotechnology research and future applications in neurosurgery.

    Science.gov (United States)

    Mattei, Tobias A; Rehman, Azeem A

    2015-01-01

    The term "nanotechnology" refers to the development of materials and devices that have been designed with specific properties at the nanometer scale (10(-9) m), usually being less than 100 nm in size. Recent advances in nanotechnology have promised to enable visualization and intervention at the subcellular level, and its incorporation to future medical therapeutics is expected to bring new avenues for molecular imaging, targeted drug delivery, and personalized interventions. Although the central nervous system presents unique challenges to the implementation of new therapeutic strategies involving nanotechnology (such as the heterogeneous molecular environment of different CNS regions, the existence of multiple processing centers with different cytoarchitecture, and the presence of the blood-brain barrier), numerous studies have demonstrated that the incorporation of nanotechnology resources into the armamentarium of neurosurgery may lead to breakthrough advances in the near future. In this article, the authors present a critical review on the current 'state-of-the-art' of basic research in nanotechnology with special attention to those issues which present the greatest potential to generate major therapeutic progresses in the neurosurgical field, including nanoelectromechanical systems, nano-scaffolds for neural regeneration, sutureless anastomosis, molecular imaging, targeted drug delivery, and theranostic strategies.

  6. Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery.

    Science.gov (United States)

    Aguirre-Cruz, Lucinda; Rangel-López, Edgar; Cruz-Aguilera, Dora Luz de la; Rodríguez-Pérez, Citlali Ekaterina; Ruano, Luis; Velásquez-Pérez, Leora; Martínez-Moreno, Mauricio; Garduño-Espinosa, Juan; Sotelo, Julio

    2016-04-01

    To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

  7. Rivaling Paradigms in Psychiatric Neurosurgery: Adjustability versus Quick Fix versus Minimal-Invasiveness

    Directory of Open Access Journals (Sweden)

    Müller eSabine

    2015-04-01

    Full Text Available In the wake of deep brain stimulation (DBS development, ablative neurosurgical procedures are seeing a comeback, although they had been discredited and nearly completely abandoned in the 1970ies because of their unethical practice. Modern stereotactic ablative procedures as thermal or radiofrequency ablation, and particularly radiosurgery (e.g., Gamma Knife are much safer than the historical procedures, so that a re-evaluation of this technique is required. The different approaches of modern psychiatric neurosurgery refer to different paradigms: Microsurgical ablative procedures is based on the paradigm ‘quick fix’, radiosurgery on the paradigm ‘minimal-invasiveness’, and DBS on the paradigm ‘adjustability’.From a mere medical perspective, none of the procedures is absolutely superior; rather, they have different profiles of advantages and disadvantages. Therefore, individual factors are crucial in decision-making, particularly the patients’ social situation, individual preferences, and individual attitudes.The different approaches are not only rivals, but also enriching mutually. DBS is preferable for exploring new targets, which may become candidates for ablative microsurgery or radiosurgery.

  8. Use of Modern Chemical Protein Synthesis and Advanced Fluorescent Assay Techniques to Experimentally Validate the Functional Annotation of Microbial Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Kent, Stephen [University of Chicago

    2012-07-20

    The objective of this research program was to prototype methods for the chemical synthesis of predicted protein molecules in annotated microbial genomes. High throughput chemical methods were to be used to make large numbers of predicted proteins and protein domains, based on microbial genome sequences. Microscale chemical synthesis methods for the parallel preparation of peptide-thioester building blocks were developed; these peptide segments are used for the parallel chemical synthesis of proteins and protein domains. Ultimately, it is envisaged that these synthetic molecules would be ‘printed’ in spatially addressable arrays. The unique ability of total synthesis to precision label protein molecules with dyes and with chemical or biochemical ‘tags’ can be used to facilitate novel assay technologies adapted from state-of-the art single molecule fluorescence detection techniques. In the future, in conjunction with modern laboratory automation this integrated set of techniques will enable high throughput experimental validation of the functional annotation of microbial genomes.

  9. Effects of experimentally elevated traffic noise on nestling white-crowned sparrow stress physiology, immune function and life history.

    Science.gov (United States)

    Crino, Ondi L; Johnson, Erin E; Blickley, Jessica L; Patricelli, Gail L; Breuner, Creagh W

    2013-06-01

    Roads have been associated with behavioral and physiological changes in wildlife. In birds, roads decrease reproductive success and biodiversity and increase physiological stress. Although the consequences of roads on individuals and communities have been well described, the mechanisms through which roads affect birds remain largely unexplored. Here, we examine one mechanism through which roads could affect birds: traffic noise. We exposed nestling mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) to experimentally elevated traffic noise for 5 days during the nestling period. Following exposure to traffic noise we measured nestling stress physiology, immune function, body size, condition and survival. Based on prior studies, we expected the traffic noise treatment to result in elevated stress hormones (glucocorticoids), and declines in immune function, body size, condition and survival. Surprisingly, nestlings exposed to traffic noise had lower glucocorticoid levels and improved condition relative to control nests. These results indicate that traffic noise does affect physiology and development in white-crowned sparrows, but not at all as predicted. Therefore, when evaluating the mechanisms through which roads affect avian populations, other factors (e.g. edge effects, pollution and mechanical vibration) may be more important than traffic noise in explaining elevated nestling stress responses in this species.

  10. Experimental coccidiosis influences the expression of the ABCB1 gene, a physiological important functional marker of intestinal integrity in chickens.

    Science.gov (United States)

    Haritova, Aneliya; Koinarski, Vencislav; Stanilova, Spaska

    2013-01-01

    Efflux transporters belonging to the family of ABC transporters have an important functional role in the maintenance of the intestinal barrier. As efflux transporters they prevent the absorption of toxic substances from feed, while at the same time facilitating the excretion of metabolic waste products as well as drugs from the circulation into the intestinal lumen. As Eimeria tenella infection significantly affects the integrity of caecum, the effects of experimental E. tenella infection on the levels of expression of ABCB1 mRNAs in the intestines and livers of broilers were evaluated. ABCB1 mRNA expression was quantified by qRT-PCR. Its expression levels were significantly down-regulated in the caecum of infected animals. The levels of ABCB1 mRNA were not changed in the duodenum and the liver. After treatment of the animals with sulfapyrazine for three days, not only a significant improvement of the clinical appearance but also a normalization of the P-gp expression was noticed. Although the current study cannot distinguish between the direct effect of the drug on the host and the drug action on the parasite, these results suggest that the treatment of coccidiosis with sulfachlorpyrazine also restored the expression of the investigated efflux transporter in the caecum. This is of clinical significance as P-glycoproteins contribute to the integrity of intestines and their function as important biological barriers, protecting poultry from pathogens and toxic compounds in animal feeds.

  11. Experimental Determination of the Dynamic Hydraulic Transfer Function for the J-2X Oxidizer Turbopump. Part One; Methodology

    Science.gov (United States)

    Zoladz, Tom; Patel, Sandeep; Lee, Erik; Karon, Dave

    2011-01-01

    An advanced methodology for extracting the hydraulic dynamic pump transfer matrix (Yp) for a cavitating liquid rocket engine turbopump inducer+impeller has been developed. The transfer function is required for integrated vehicle pogo stability analysis as well as optimization of local inducer pumping stability. Laboratory pulsed subscale waterflow test of the J-2X oxygen turbo pump is introduced and our new extraction method applied to the data collected. From accurate measures of pump inlet and discharge perturbational mass flows and pressures, and one-dimensional flow models that represents complete waterflow loop physics, we are able to derive Yp and hence extract the characteristic pump parameters: compliance, pump gain, impedance, mass flow gain. Detailed modeling is necessary to accurately translate instrument plane measurements to the pump inlet and discharge and extract Yp. We present the MSFC Dynamic Lump Parameter Fluid Model Framework and describe critical dynamic component details. We report on fit minimization techniques, cost (fitness) function derivation, and resulting model fits to our experimental data are presented. Comparisons are made to alternate techniques for spatially translating measurement stations to actual pump inlet and discharge.

  12. 2,3-Pyridine dicarboxylic acid functionalized gold nanoparticles: Insight into experimental conditions for Cr3 + sensing

    Science.gov (United States)

    Shaikh, Ruqaya; Memon, Najma; Solangi, Amber R.; Shaikh, Huma I.; Agheem, Muhammad Hassan; Ali, Syed Abid; Shah, Muhammad Raza; Kandhro, Aftab

    2017-02-01

    Selectivity of gold nanoparticles (AuNPs) depends upon surface functionality; small changes in structure or concentration bring significant changes in the behavior of AuNPs. In this study, citrate-capped AuNPs were functionalized with ortho-dicarboxylate substituted pyridine (2,3-PDCA) and detailed studies on experimental conditions were carried out to check the stability of AuNPs and response for Cr3 +. Stability of PDCA-AuNPs was found sensitive to the pH, ionic strength of buffer and its type. Capping behavior of PDCA on C-AuNPs was examined by FTIR spectroscopy. Surface morphology and size of synthesized AuNPs were confirmed by AFM, XRD, and DLS techniques where particles were found 11 nm in size, monodisperse and spherical in shape. Interaction of stabilized AuNPs was tested with various metal ions; where Cr3 + induced the changes in localized surface plasmon band (LSPR) of PDCA-AuNPs which leads to a color change from wine red to violet blue. The phenomenon is explained as cooperative effect of citrate and pyridine nitrogen on surface of AuNPs in contrary to meta-dicarboxylate substituted pyridine derivatives. Further, under optimized and controlled conditions Cr3 + shows linear response with decrease in absorbance at LSPR intensity of AuNPs (518 nm). Moreover, to demonstrate the applicability of method, Cr3 + was determined in the presence of Cr (VI) which shows 96% recovery.

  13. Evaluation of a density functional with account of van der Waals forces using experimental data of H2 physisorption on Cu(111)

    DEFF Research Database (Denmark)

    Lee, Kyuho; Kelkkanen, Kari André; Berland, Kristian

    2011-01-01

    Detailed experimental data for physisorption potential-energy curves of H2 on low-indexed faces of Cu challenge theory. Recently, density-functional theory has been developed to also account for nonlocal correlation effects, including van der Waals forces. We show that one functional, denoted vd...

  14. Perceived benefits and barriers to a career in pediatric neurosurgery: a survey of neurosurgical residents.

    Science.gov (United States)

    Dias, Mark S; Sussman, Jeffrey S; Durham, Susan; Iantosca, Mark R

    2013-11-01

    Research suggests that there may be a growing disparity between the supply of and demand for both pediatric specialists and neurosurgeons. Whether pediatric neurosurgeons are facing such a disparity is disputable, but interest in pediatric neurosurgery (PNS) has waxed and waned as evidenced by the number of applicants for PNS fellowships. The authors undertook a survey to analyze current neurosurgical residents' perceptions of both benefits and deterrents to a pediatric neurosurgical career. All residents and PNS fellows in the United States and Canada during the academic year 2008-2009 were invited to complete a Web-based survey that assessed 1) demographic and educational information about residents and their residency training, particularly as it related to training in PNS; 2) residents' exposure to mentoring opportunities from pediatric neurosurgical faculty and their plans for the future; and 3) residents' perceptions about how likely 40 various factors were to influence their decision about whether to pursue a PNS career. Four hundred ninety-six responses were obtained: 89% of the respondents were male, 63% were married, 75% were in at least their 3rd year of postgraduate training, 61% trained in a children's hospital and 29% in a children's "hospital within a hospital," and 72% were in programs having one or more dedicated PNS faculty members. The residencies of 56% of respondents offered 6-11 months of PNS training and nearly three-quarters of respondents had completed 2 months of PNS training. During medical school, 92% had been exposed to neurosurgery and 45% to PNS during a clinical rotation, but only 7% identified a PNS mentor. Nearly half (43%) are considering a PNS career, and of these, 61% are definitely or probably considering post-residency fellowship. On the other hand, 68% would prefer an enfolded fellowship during residency. Perceived strengths of PNS included working with children, developing lasting relationships, wider variety of operations

  15. MAOA-uVNTR genotype predicts interindividual differences in experimental aggressiveness as a function of the degree of provocation.

    Science.gov (United States)

    Kuepper, Yvonne; Grant, Phillip; Wielpuetz, Catrin; Hennig, Juergen

    2013-06-15

    The MAOA-uVNTR has been suggested to play a role regarding aggression, however, results are inconsistent. We aimed at further elucidating potential effects of the MAOA-uVNTR on aggressiveness with respect to potential modulators: sex, experimental vs. trait aggressiveness and type of aggressiveness (proactive vs. reactive aggressiveness). We tested 239 healthy young adults (88 men/151 women). Participants were genotyped for the MAOA-uVNTR and performed a modified version of a competitive reaction time task - a commonly used and well established tool to elicit and measure aggressiveness. Furthermore, they completed a self-report scale measuring trait aggressiveness. We found a main effect of MAOA-uVNTR on a measure of reactive aggressiveness for both men and women, whereby the low-activity alleles of the MAOA-uVNTR were associated with substantially increased aggressive reactions (paggressiveness. Measures of proactive aggressiveness or self reports were not associated with the MAOA-uVNTR-genotype. Our data are in line with earlier studies and indicate the MAOA-uVNTR-genotype to be specifically associated with measures of reactive impulsive experimental aggressiveness in healthy men and women. Furthermore the association between the MAOA-uVNTR genotype and aggressive responses increases in a fashion linear to the degree of provocation. This indicates that the low-functional alleles of the MAOA-uVNTR are not associated with increased aggressive behavior per se, but rather with an increased aggressive reactivity to provocation. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Generating information-rich high-throughput experimental materials genomes using functional clustering via multitree genetic programming and information theory.

    Science.gov (United States)

    Suram, Santosh K; Haber, Joel A; Jin, Jian; Gregoire, John M

    2015-04-13

    High-throughput experimental methodologies are capable of synthesizing, screening and characterizing vast arrays of combinatorial material libraries at a very rapid rate. These methodologies strategically employ tiered screening wherein the number of compositions screened decreases as the complexity, and very often the scientific information obtained from a screening experiment, increases. The algorithm used for down-selection of samples from higher throughput screening experiment to a lower throughput screening experiment is vital in achieving information-rich experimental materials genomes. The fundamental science of material discovery lies in the establishment of composition-structure-property relationships, motivating the development of advanced down-selection algorithms which consider the information value of the selected compositions, as opposed to simply selecting the best performing compositions from a high throughput experiment. Identification of property fields (composition regions with distinct composition-property relationships) in high throughput data enables down-selection algorithms to employ advanced selection strategies, such as the selection of representative compositions from each field or selection of compositions that span the composition space of the highest performing field. Such strategies would greatly enhance the generation of data-driven discoveries. We introduce an informatics-based clustering of composition-property functional relationships using a combination of information theory and multitree genetic programming concepts for identification of property fields in a composition library. We demonstrate our approach using a complex synthetic composition-property map for a 5 at. % step ternary library consisting of four distinct property fields and finally explore the application of this methodology for capturing relationships between composition and catalytic activity for the oxygen evolution reaction for 5429 catalyst compositions in a

  17. Risk factors for surgical site infections after neurosurgery: A focus on the postoperative period.

    Science.gov (United States)

    Cassir, Nadim; De La Rosa, Silvestre; Melot, Anthony; Touta, Adamou; Troude, Lucas; Loundou, Anderson; Richet, Hervé; Roche, Pierre-Hugues

    2015-12-01

    Surgical site infection (SSI) after neurosurgery has potentially devastating consequences. A prospective cohort study was conducted over a period of 24 months in a university center. All adult patients undergoing neurosurgical procedures, with exception of open skull fractures, were included. Multivariate logistic regression analysis was used to identify independent risk factors. We included 949 patients. Among them, 43 were diagnosed with SSI (4.5%). A significant reduction in postneurosurgical SSI from 5.8% in 2009 to 3.0% in 2010 (P = .04) was observed. During that period, an active surveillance with regular feedback was established. The most common microorganisms isolated from SSI were Staphylococcus aureus (23%), Enterobacteriaceae (21%), and Propionibacterium acnes (12%). We identified the following independent risk factors for SSI postcranial surgery: intensive care unit (ICU) length of stay ≥7 days (odds ratio [OR] = 6.1; 95% confidence interval [CI], 1.7-21.7), duration of drainage ≥3 days (OR = 3.3; 95% CI, 1.1-11), and cerebrospinal fluid leakage (OR = 5.6; 95% CI, 1.1-30). For SSIs postspinal surgery, we identified the following: ICU length of stay ≥7 days (OR = 7.2; 95% CI, 1.6-32.1), coinfection (OR = 9.9; 95% CI, 2.2-43.4), and duration of drainage ≥3 days (OR = 5.7; 95% CI, 1.5-22). Active surveillance with regular feedback proved effective in reducing SSI rates. The postoperative period is associated with overlooked risk factors for neurosurgical SSI. Infection control measures targeting this period are therefore promising. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  18. The 2009 devaluation of radiosurgery and its impact on the neurosurgery-radiation oncology partnership.

    Science.gov (United States)

    Heilbrun, M Peter; Adler, John R

    2010-07-01

    Neurosurgeons, radiation oncologists, and, increasingly, other surgical specialists recognize that radiosurgery is an important tool for managing selected disorders throughout the body. The partnership between neurosurgeons and radiation oncologists has resulted in collaborative studies that have established the clinical benefits of radiosurgery. Today, however, a range of political and financial issues is straining this relationship and thereby undermining the practice of radiosurgery. Neurosurgeons and radiation oncologists recently restricted the definition of radiosurgery to include only cranial- and spine-focused radiation treatments. Meanwhile, organized radiation oncology decided unilaterally that radiosurgery administered to other parts of the body would be termed stereotactic body radiation therapy. Finally, neurosurgical and radiation oncology coding experts developed new Current Procedural Terminology codes for cranial vault and spine radiosurgery, which were approved for use by the Relative Value Scale Update Committee as of 2009. The authors suggest that the neurosurgery strategy-which included 1) reasserting that all of the tasks of a radiosurgery procedure remain bundled, and 2) agreeing to limit the definition of radiosurgery to cranial vault and spine-has failed neurosurgeons who perform radiosurgery, and it may jeopardize patient access to this procedure in the future. The authors propose that all of the involved medical specialties recognize that the application of image-guided, focused radiation therapy throughout the body requires a partnership between radiation and surgical disciplines. They also urge surgeons to reexamine their coding methods, and they maintain that Current Procedural Terminology codes should be consistent across all of the different specialties involved in these procedures. Finally, surgeons should consider appropriate training in medical physics and radiobiology to perform the tasks involved in these specific procedures

  19. Financial and clinical governance implications of clinical coding accuracy in neurosurgery: a multidisciplinary audit.

    Science.gov (United States)

    Haliasos, N; Rezajooi, K; O'neill, K S; Van Dellen, J; Hudovsky, Anita; Nouraei, Sar

    2010-04-01

    Clinical coding is the translation of documented clinical activities during an admission to a codified language. Healthcare Resource Groupings (HRGs) are derived from coding data and are used to calculate payment to hospitals in England, Wales and Scotland and to conduct national audit and benchmarking exercises. Coding is an error-prone process and an understanding of its accuracy within neurosurgery is critical for financial, organizational and clinical governance purposes. We undertook a multidisciplinary audit of neurosurgical clinical coding accuracy. Neurosurgeons trained in coding assessed the accuracy of 386 patient episodes. Where clinicians felt a coding error was present, the case was discussed with an experienced clinical coder. Concordance between the initial coder-only clinical coding and the final clinician-coder multidisciplinary coding was assessed. At least one coding error occurred in 71/386 patients (18.4%). There were 36 diagnosis and 93 procedure errors and in 40 cases, the initial HRG changed (10.4%). Financially, this translated to pound111 revenue-loss per patient episode and projected to pound171,452 of annual loss to the department. 85% of all coding errors were due to accumulation of coding changes that occurred only once in the whole data set. Neurosurgical clinical coding is error-prone. This is financially disadvantageous and with the coding data being the source of comparisons within and between departments, coding inaccuracies paint a distorted picture of departmental activity and subspecialism in audit and benchmarking. Clinical engagement improves accuracy and is encouraged within a clinical governance framework.

  20. Computer-assisted neurosurgery system: Wayne State University hardware and software configuration.

    Science.gov (United States)

    Zamorano, L; Jiang, Z; Kadi, A M

    1994-01-01

    Computer-assisted neurosurgery uses the latest technological advancements in imaging, computers, mechanics, and electronics to improve the accuracy and reduce the invasiveness and risk of neurosurgical procedures. We describe the Wayne State University, Detroit, Michigan, computer-assisted neurosurgical system with the emphasis on software and discuss the theory guiding the development of this system and its application in real-time position tracking systems. Our system consists of the Neurological Surgery Planning System (NSPS) software which we developed at our medical center and three types of position tracking systems: the Zamorano-Dujovny (Z-D) are digitizer for frame-based procedures, an articulated arm, and an infrared-based digitizer for frameless procedures. The NSPS software is designed to offer neurosurgeons a safe and accurate method to approach intracranial lesions by preoperatively planning a surgical trajectory. Software consisting of the most advanced technologies in computer vision, computer imaging/graphics, and stereotactic numeric analysis forms the core of the system. Capabilities for correlating data from imaging studies to facilitate image reconstruction, image mapping, and three-dimensional (3D) visualization of target volumes enable the neurosurgeon to simulate surgical procedures into a preoperative protocol to be used during surgery, both to follow the preplanned trajectory and to track the position of surgical instruments in real-time on the computer monitor. The tracking systems position and orient the surgical instruments relative to the patient's head. With these devices, the display of the surgical instruments together with the virtual images create an excellent intraoperative tool.

  1. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    Energy Technology Data Exchange (ETDEWEB)

    Alva-Sánchez, Héctor, E-mail: halva@ciencias.unam.mx [Unidad de Imagen Molecular PET/CT, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F. (Mexico); Reynoso-Mejía, Alberto [Unidad de Imagen Molecular PET/CT, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F., Mexico and Departamento de Neuroimagen, Instituto Nacional de (Mexico); Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús [Departamento de Neuroimagen, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F. (Mexico)

    2014-11-07

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  2. 335 A Modular, Multimodality Integrative Pipeline for Neurosurgery Simulation and Visualization.

    Science.gov (United States)

    Costa, Anthony Beardsworth; Bederson, Joshua B

    2016-08-01

    The practice of pre- and intraoperative interactive visualization and modeling continues to grow as its value to clinical practice is augmented by new technologies, such as virtual and augmented reality, or 3D printing. Current tools that extract the necessary structural information from medical imaging modalities and allow virtual or other interrogation of the data are either difficult to use in a practical clinical setting, or sufficiently simple as to limit the knowledge available to the operator. Nonetheless, the broader medical visualization and simulation communities have invented tools that enable automated segmentation and interrogation of structures critical to the success of surgery, such as cranial nerves, vasculature, and cortical and subcortical parcellations. We leverage these tools as inputs to a novel pipeline for neurosurgery simulation. Our pipeline is compatible with ATLAS-based subcortical volumetric segmentation (eg, Freesurfer, ANTS), or any structural input in mesh- or voxel-based formats, together with volumetric data. The visualizer, based on VTK7's OpenGL3x rendering backend, is efficient enough to display an arbitrary number of input structures or volumes at interactive refresh rates. Structures can be manipulated by adjusting parameters for each structure independently (eg, color, opacity). Standard ATLAS-based and ITK/VTK-based tools are included in the pipeline directly. Also included is a novel volumetric shift-based segmentation tool, allowing an operating scientist to easily include information detailing aberrant pathologies rapidly and with minimal semantic information. We demonstrate these tools for a variety of cases, including tumor, vascular, hemorrhagic stroke, and spine. Its performance sufficient to run and be used on a laptop computer and capabilities for preoperative planning through 3D printing the generated structures. We find that repurposing the power of existing segmentation tools within a novel modular, multimodal

  3. Max Brödel: his art, legacy, and contributions to neurosurgery through medical illustration.

    Science.gov (United States)

    Patel, Smruti K; Couldwell, William T; Liu, James K

    2011-07-01

    Max Brödel is considered the father of modern medical illustration. This report reviews his contributions to neurosurgery as a medical illustrator. Max Brödel, a young artist from Leipzig, Germany, was hired at Johns Hopkins Hospital in 1894, where he illustrated an operative textbook of gynecology for Howard A. Kelly. Although Brödel did not have any formal medical training, he quickly acquired knowledge of anatomy, pathology, physiology, and surgery. Brödel's extraordinary illustrations were characterized by an aerial perspective that conveyed the surgeon's operative viewpoint and precise surgical anatomy. He masterfully incorporated tissue realism with cross-sectional anatomy to accentuate concepts while maintaining topographical accuracy. Brödel's reputation spread quickly and resulted in collaborations with prominent surgeons, such as Cushing, Halsted, and Dandy. Cushing, who also possessed artistic talent, became a pupil of Brödel and remained a very close friend. In 1911, Brödel was appointed the director of the Department of Art as Applied to Medicine at Johns Hopkins, the first academic department of its kind in the world. For the next several decades, he trained generations of renowned medical illustrators. Just as Osler, Halsted, and Cushing passed their skills and knowledge to future leaders of medicine and surgery, Brödel did the same for the field of medical illustration. The advancement of neurosurgical education has been greatly facilitated by Max Brödel's artistic contributions. His unique ability to synthesize art and medicine resulted in timeless illustrations that remain indispensable to surgeons. The art produced by his legacy of illustrators continues to flourish in neurosurgical literature today.

  4. Intracranial meningiomas managed at Memfys hospital for neurosurgery in Enugu, Nigeria

    Directory of Open Access Journals (Sweden)

    Wilfred C Mezue

    2012-01-01

    Full Text Available Introduction: The epidemiology and pathology of meningioma in Nigeria are still evolving and little has been published about this tumor in Nigeria, especially in the southeast region. The aim of this paper is to compare the characteristics of intracranial meningioma managed in our center with the pattern reported in the literature worldwide. Materials and Methods: Retrospective analysis of prospectively recorded data of patients managed for intracranial meningioma between January 2002 and December 2010 at a Private neurosurgery Hospital in Enugu, Nigeria. We excluded patients whose histology results were inconclusive. Results: Meningiomas constituted 23.8% of all intracranial tumors seen in the period. The male to female ratio was 1:1.1. The peak age range for males and females were in the fifth and sixth decades, respectively. The most common location is the Olfactory groove in 26.5% of patients followed by convexity in 23.5%. Presentation varied with anatomical location of tumor. Patients with olfactory groove meningioma (OGM mostly presented late with personality changes and evidence of raised ICP. Tuberculum sellar and sphenoid region tumors presented earlier with visual impairment with or without hormonal abnormalities. Seizures occurred in 30.9% of all patients and in 45% of those with convexity meningiomas. Only 57.4% of the patients were managed surgically and there was no gender difference in this group. WHO grade1 tumors were the most common histological types occurring in 84.6%. One patient had atypical meningioma and two had anaplastic tumors. Conclusion: The pattern of meningioma in our area may have geographical differences in location and histology. Childhood meningioma was rare.

  5. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    Science.gov (United States)

    Alva-Sánchez, Héctor; Reynoso-Mejía, Alberto; Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús

    2014-11-01

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  6. Laser range scanning for image-guided neurosurgery: investigation of image-to-physical space registrations.

    Science.gov (United States)

    Cao, Aize; Thompson, R C; Dumpuri, P; Dawant, B M; Galloway, R L; Ding, S; Miga, M I

    2008-04-01

    In this article a comprehensive set of registration methods is utilized to provide image-to-physical space registration for image-guided neurosurgery in a clinical study. Central to all methods is the use of textured point clouds as provided by laser range scanning technology. The objective is to perform a systematic comparison of registration methods that include both extracranial (skin marker point-based registration (PBR), and face-based surface registration) and intracranial methods (feature PBR, cortical vessel-contour registration, a combined geometry/intensity surface registration method, and a constrained form of that method to improve robustness). The platform facilitates the selection of discrete soft-tissue landmarks that appear on the patient's intraoperative cortical surface and the preoperative gadolinium-enhanced magnetic resonance (MR) image volume, i.e., true corresponding novel targets. In an 11 patient study, data were taken to allow statistical comparison among registration methods within the context of registration error. The results indicate that intraoperative face-based surface registration is statistically equivalent to traditional skin marker registration. The four intracranial registration methods were investigated and the results demonstrated a target registration error of 1.6 +/- 0.5 mm, 1.7 +/- 0.5 mm, 3.9 +/- 3.4 mm, and 2.0 +/- 0.9 mm, for feature PBR, cortical vessel-contour registration, unconstrained geometric/intensity registration, and constrained geometric/intensity registration, respectively. When analyzing the results on a per case basis, the constrained geometric/intensity registration performed best, followed by feature PBR, and finally cortical vessel-contour registration. Interestingly, the best target registration errors are similar to targeting errors reported using bone-implanted markers within the context of rigid targets. The experience in this study as with others is that brain shift can compromise extracranial

  7. Cerebrospinal fluid and blood propofol concentration during total intravenous anaesthesia for neurosurgery.

    Science.gov (United States)

    Dawidowicz, A L; Fijałkowska, A; Nestorowicz, A; Kalityński, R; Trojanowski, T

    2003-01-01

    The aim of this paper is to compare the propofol concentration in blood and cerebrospinal fluid (CSF) in patients scheduled for different neurosurgical procedures and anaesthetized using propofol as part of a total intravenous anaesthesia technique. Thirty-nine patients (ASA I-III) scheduled for elective intracranial procedures, were studied. Propofol was infused initially at 12 mg kg(-1) h(-1) and then reduced in steps to 9 and 6 mg kg(-1) h(-1). During anaesthesia, bolus doses of fentanyl and cis-atracurium were administered as necessary. After tracheal intubation the lungs were ventilated to achieve normocapnia with an oxygen-air mixture (FI(O(2))=0.33). Arterial blood and CSF samples for propofol examination were obtained simultaneously directly after intracranial drainage insertion and measured using high-performance liquid chromatography. The patients were divided into two groups depending on the type of neurosurgery. The Aneurysm group consisted of 13 patients who were surgically treated for ruptured intracranial aneurysm. The Tumour group was composed of 26 patients who were undergoing elective posterior fossa extra-axial tumour removal. Blood propofol concentrations in both groups did not differ significantly (P>0.05). The propofol concentration in CSF was 86.62 (SD 37.99) ng ml(-1) in the Aneurysm group and 50.81 (26.10) ng ml(-1) in the Tumour group (P<0.005). Intracranial pathology may influence CSF propofol concentration. However, the observed discrepancies may also result from quantitative differences in CSF composition and from restricted diffusion of the drug in the CSF.

  8. In situ synthesis and surface functionalization of gold nanoparticles with curcumin and their antioxidant properties: an experimental and density functional theory investigation

    Science.gov (United States)

    Singh, Dheeraj K.; Jagannathan, Ramya; Khandelwal, Puneet; Abraham, Priya Mary; Poddar, Pankaj

    2013-02-01

    Curcumin ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) is an active component of turmeric; it is responsible for its characteristic yellow color and therapeutic potential, but its poor bioavailability remains a major challenge. In order to improve the bioavailability of curcumin, various approaches have been used. One of the possible approaches to increase the bioavailability of curcumin is its conjugation on the surface of metal nanoparticles. Therefore, in the present study, we report the binding of curcumin on the surface of gold nanoparticles (AuNPs). The AuNPs were synthesized by the direct reduction of HAuCl4 using curcumin in the aqueous phase, without the use of any other reducing agents. We found that curcumin acts both as a reducing and capping agent, stabilizing the gold sol for many months. Moreover, these curcumin-capped AuNPs also show good antioxidant activity which was confirmed by the DPPH (2,2-diphenyl-l-picrylhydrazyl) radical test. Thus, the surface functionalization of AuNPs with curcumin may pave a new way of using the curcuminoids towards possible drug delivery and therapeutics. Apart from the experimental study, a detailed quantum chemical calculation using density functional theory (DFT) has been performed, in order to investigate the formation of a complex of curcumin with Au3+ ions in different possible conformational isomeric forms. Our theoretical calculations indicate the evidence of electron transfer from curcumin into the Au center and essentially indicate that as a consequence of complexation, Au3+ ions are reduced to Au0. Our theoretical results also propose that it is the breakage of intramolecular H-bonding that probably leads to the increased availability of curcumin in the presence of gold ions and water molecules.Curcumin ((1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) is an active component of turmeric; it is responsible for its characteristic yellow color and therapeutic

  9. Experimental determination of organic liquid fuels heating value as function of the humidity; Determinacao experimental do poder calorifico de combustiveis organicos liquidos em funcao da umidade

    Energy Technology Data Exchange (ETDEWEB)

    Lyrio, Aristoteles Alves; Dalvi, Elias Antonio; Vieira, Renata da Cruz Araujo [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Engenharia Mecanica

    1998-07-01

    This work presents experimental results for higher heating value (HHV) and lower heating value (LHV) of organic liquid fuels sold in gas stations situated at Vitoria Metropolitan Area in the state of Espirito Santo, Brazil. Experiments were conduced showing the influence of fuel water contents on the HHV and LHV such as gasoline, diesel oil, kerosene and alcohol, covering a wide range of humidity (0 to 70%). A correlation between higher heating value and the water content in the fuel was determined for the experimental data obtained. The main conclusion of the present work has shown that the content of water in the fuel makes its higher heating value to decrease in the same proportion as the value of the humidity (ratio between mass of water and mass of fuel mass of water), and so, it is very important to control the level of humidity in the fuel in order to avoid significant losses of heat released during the fuel combustion. (author)

  10. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo; Mukdsi, Jorge Humberto [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela [Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Av. Haya de la Torre y Medina Allende, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Gutiérrez, Silvina; Torres, Alicia Inés [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); De Paul, Ana Lucía, E-mail: adepaul@cmefcm.uncor.edu [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina)

    2013-11-15

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  11. Association of increased morbidity with the occurrence of hyperglycemia in the immediate postoperative period after elective pediatric neurosurgery.

    Science.gov (United States)

    Filho, Nazel Oliveira; Alves, Rodrigo L; Fernandes, Adriano T; Castro, Fernanda S P; Melo, José Roberto Tude; Módolo, Norma S P

    2016-05-01

    OBJECTIVE The acute elevation of blood glucose in perioperative pediatric patients subjected to cardiac surgery and in victims of head trauma is associated with higher rates of postoperative complications. Data on the occurrence of hyperglycemia and its association with unfavorable outcomes among patients who have undergone elective neurosurgery are scarce in the literature. This study aimed to determine whether the occurrence of hyperglycemia during the perioperative period of elective neurosurgery for the resection of tumors of the CNS in children is associated with increased morbidity. METHODS This retrospective cohort analysis included 105 children up to 12 years of age who underwent elective neurosurgery for resection of supratentorial and infratentorial CNS tumors between January 2005 and December 2010 at the São Rafael Hospital, a tertiary care medical center in Salvador, Brazil. Demographic data and intraoperative and postoperative information were collected from the medical records. Differences in blood glucose levels during the perioperative period were evaluated with nonparametric tests. RESULTS The patients who developed postoperative complications exhibited higher blood glucose levels on admission to the intensive care unit (ICU) (162.0 ± 35.8 mg/dl vs 146.3 ± 43.3 mg/dl; p = 0.016) and peak blood glucose levels on postoperative Day 1 (171.9 ± 30.2 mg/dl vs 156.1 ± 43.2 mg/dl; p = 0.008). Multivariate analysis showed that peak blood glucose levels on postoperative Day 1 were independently associated with a higher odds ratio for postoperative complication (OR 1.05). The occurrence of hyperglycemia (>150 mg/dl) upon admission to the ICU was associated with longer ICU (p = 0.003) and hospital (p = 0.001) stays. CONCLUSIONS The occurrence of hyperglycemia during the postoperative period after elective pediatric neurosurgery for the resection of CNS tumors was associated with longer hospital and ICU stays. Postoperative complications were associated

  12. Functional interleukin-17 receptor A is expressed in central nervous system glia and upregulated in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Das Sarma, Jayasri; Ciric, Bogoljub; Marek, Ryan; Sadhukhan, Sanjoy; Caruso, Michael L; Shafagh, Jasmine; Fitzgerald, Denise C; Shindler, Kenneth S; Rostami, Am

    2009-04-28

    Interleukin-17A (IL-17A) is the founding member of a novel family of inflammatory cytokines that plays a critical role in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood. EAE was induced in C57Bl/6 mice by immunization with myelin oligodendroglial glycoprotein. IL-17RA expression in the CNS was compared between control and EAE mice using RT-PCR, in situ hybridization, and immunohistochemistry. Cell-type specific expression was examined in isolated astrocytic and microglial cell cultures. Cytokine and chemokine production was measured in IL-17A treated cultures to evaluate the functional status of IL-17RA. Here we report increased IL-17RA expression in the CNS of mice with EAE, and constitutive expression of functional IL-17RA in mouse CNS tissue. Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion. Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA. IL-17RA expression is significantly increased in the CNS of mice with EAE compared to healthy mice, suggesting that IL-17RA signaling in glial cells can play an important role in autoimmune inflammation of the CNS and may be a potential pathway to target for therapeutic interventions.

  13. Functional interleukin-17 receptor A is expressed in central nervous system glia and upregulated in experimental autoimmune encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Shafagh Jasmine

    2009-04-01

    Full Text Available Abstract Background Interleukin-17A (IL-17A is the founding member of a novel family of inflammatory cytokines that plays a critical role in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS and its animal model, experimental autoimmune encephalomyelitis (EAE. IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS and its role in CNS inflammation are not well understood. Methods EAE was induced in C57Bl/6 mice by immunization with myelin oligodendroglial glycoprotein. IL-17RA expression in the CNS was compared between control and EAE mice using RT-PCR, in situ hybridization, and immunohistochemistry. Cell-type specific expression was examined in isolated astrocytic and microglial cell cultures. Cytokine and chemokine production was measured in IL-17A treated cultures to evaluate the functional status of IL-17RA. Results Here we report increased IL-17RA expression in the CNS of mice with EAE, and constitutive expression of functional IL-17RA in mouse CNS tissue. Specifically, astrocytes and microglia express IL-17RA in vitro, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion. Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA. Conclusion IL-17RA expression is significantly increased in the CNS of mice with EAE compared to healthy mice, suggesting that IL-17RA signaling in glial cells can play an important role in autoimmune inflammation of the CNS and may be a potential pathway to target for therapeutic interventions.

  14. Dependence of invadopodia function on collagen fiber spacing and cross-linking: computational modeling and experimental evidence.

    Science.gov (United States)

    Enderling, Heiko; Alexander, Nelson R; Clark, Emily S; Branch, Kevin M; Estrada, Lourdes; Crooke, Cornelia; Jourquin, Jérôme; Lobdell, Nichole; Zaman, Muhammad H; Guelcher, Scott A; Anderson, Alexander R A; Weaver, Alissa M

    2008-09-01

    Invadopodia are subcellular organelles thought to be critical for extracellular matrix (ECM) degradation and the movement of cells through tissues. Here we examine invadopodia generation, turnover, and function in relation to two structural aspects of the ECM substrates they degrade: cross-linking and fiber density. We set up a cellular automaton computational model that simulates ECM penetration and degradation by invadopodia. Experiments with denatured collagen (gelatin) were used to calibrate the model and demonstrate the inhibitory effect of ECM cross-linking on invadopodia degradation and penetration. Incorporation of dynamic invadopodia behavior into the model amplified the effect of cross-linking on ECM degradation, and was used to model feedback from the ECM. When the model was parameterized with spatial fibrillar dimensions that closely matched the organization, in real life, of native ECM collagen into triple-helical monomers, microfibrils, and macrofibrils, little or no inhibition of invadopodia penetration was observed in simulations of sparse collagen gels, no matter how high the degree of cross-linking. Experimental validation, using live-cell imaging of invadopodia in cells plated on cross-linked gelatin, was consistent with simulations in which ECM cross-linking led to higher rates of both invadopodia retraction and formation. Analyses of invadopodia function from cells plated on cross-linked gelatin and collagen gels under standard concentrations were consistent with simulation results in which sparse collagen gels provided a weak barrier to invadopodia. These results suggest that the organization of collagen, as it may occur in stroma or in vitro collagen gels, forms gaps large enough so as to have little impact on invadopodia penetration/degradation. By contrast, dense ECM, such as gelatin or possibly basement membranes, is an effective obstacle to invadopodia penetration and degradation, particularly when cross-linked. These results provide a

  15. Impact of nutrient enrichment and fish introductions on the structure and function of experimental shallow littoral lagoons

    Directory of Open Access Journals (Sweden)

    Oriol Cano-Rocabayera

    2015-12-01

    Full Text Available Mediterranean coastal lagoons are probably one of the most singular and endangered ecosystems worldwide. Common threats to other aquatic ecosystems are nutrient enrichment and species introductions. In shallow and warm areas, the environmental concern may be even exacerbated by an increase in nutrient levels and biotic interactions due to the low water flow, coupled to the temperature-sensitivity of ectotherms’ metabolism and hence ecological processes. Nutrient enrichment can benefit ecosystem productivity when the bottom-up effect of nutrients is counteracted by top-down controllers such as macro-invertebrates and/or fish. This balance can, however, be directly and indirectly disrupted by excessive fertilization and/or the release of exotic species. Ammonia and nitrite has long been considered a water quality hazard but the toxic effects of nitrates are still poorly studied. The present study examined experimentally the multi-trophic impacts of chronic nitrate exposure and/or the invasive eastern mosquitofish (Gambusia holbrooki on the structure and function of shallow littoral lagoons. Specifically, we monitored ecosystem metabolism (primary production and leaf litter decomposition and the community structure of pelagic and benthonic macro-invertebrates during 2 months. Preliminary results show that chronic nitrate pollution and/or G. holbrooki can profoundly alter the structure and function of coastal lagoon ecosystems, and that pelagic and benthonic sub-systems are coupled in response to these anthropogenic stressors. Although the long-term consequences of these findings remain to be examined in detail, this study will increase our mechanistic understanding of how the top-down and bottom-up controllers of aquatic ecosystems are affected by major drivers of global change typified by nitrate pollution and an invasive species.

  16. Experimental drought induces short-term changes in soil functionality and microbial community structure after fire in a Mediterranean shrubland

    Science.gov (United States)

    Hinojosa, M. B.; Parra, A.; Laudicina, V. A.; Moreno, J. M.

    2014-10-01

    Fire is a major ecosystem driver, causing significant changes in soil nutrients and microbial community structure and functionality. Post-fire soil dynamics can vary depending on rainfall patterns, although variations in response to drought are poorly known. This is particularly important in areas with poor soils and limited rainfall, like arid and semiarid ones. Furthermore, climate change projections in many such areas anticipate reduced precipitation and longer drought, together with an increase in fire severity. The effects of experimental drought and fire were studied on soils in a Mediterranean Cistus-Erica shrubland in Central Spain. A replicated (n = 4) field experiment was carried out in which four levels of rainfall pattern were implemented by means of a rain-out shelters and irrigation system. The treatments were: environmental control (natural rainfall), historical control (long-term average rainfall, 2 months drought), moderate drought (25% reduction of historical control, 5 months drought) and severe drought (45% reduction, 7 months drought). After one growing season, the plots were burned with high fire intensity, except a set of unburned plots that served as control. Soils were collected seasonally during one year and variables related to soil nutrient availability and microbial community structure and functionality were studied. Burned soils increased nutrient availability (P, N, K) with respect to unburned ones, but drought reduced such an increase in P, while it further increased N and K. Such changes in available soil nutrients were short-lived. Drought caused a further decrease of enzyme activities, carbon mineralization rate and microbial biomass. Fire decreased the relative abundance of fungi and actinomycetes. However, fire and drought caused a further reduction in fungi, with bacteria becoming relatively more abundant. Arguably, increasing drought and fires due to climate change will likely shift soil recovery after fire.

  17. Experimental and modeling investigation on the rheological behavior of collagen solution as a function of acetic acid concentration.

    Science.gov (United States)

    Yang, Huan; Duan, Lian; Li, Qian; Tian, Zhenhua; Li, Guoying

    2017-09-05

    Systematic analysis of the rheological behavior of collagen solution (10mg/mL) as a function of acetic acid (AA) concentration (0.1-10M) was performed to achieve a deeper understanding about the interaction between collagen molecules and acidic solvent. Steady shear tests showed that all samples exhibited pseudo-plasticity with shear-thinning behavior. Viscosity decreased from 236.448 to 0.792Pa·s at 0.1s(-1) suggesting the flow ability of collagen solution improved with increasing AA concentration. Dynamic frequency sweep analysis revealed that the storage modulus, loss modulus, and complex viscosity decreased with the increased AA concentration due to the disentanglement of collagen molecules, while the loss tangent increased. Hysteresis loop areas of collagen solutions were determined by thixotropic measurement, which demonstrated that weaker thixotropic behavior was associated with higher AA concentrations. Furthermore, the ability to resist deformation and elasticity was lower at higher AA concentration. Maximum compliance values increased from 0.042 to 376.407Pa(-1), and the recovery percentage decreased from 97.670% to 0.315%. Finally, corresponding mathematical models were employed to simulate and quantitatively assess the experimental data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Non-enzymatic glucose sensing properties of MoO3 nanorods: experimental and density functional theory investigations

    Science.gov (United States)

    Sharma, Maneesha; Gangan, Abhijeet; Chakraborty, Brahmananda; Sekhar Rout, Chandra

    2017-11-01

    We report the growth of monoclinic MoO3 nanorods by a simple and highly reproducible hydrothermal method. Structural and morphological studies provide significant insights about the phase and crystalline structure of the synthesized samples. Further, the non-enzymatic glucose sensing properties were investigated and the MoO3 nanorods exhibited a sensitivity of 15.4 µA µM‑1 cm‑2 in the 5–175 µM linear range. Also, a quick response time of 8 s towards glucose molecules was observed, exhibiting an excellent electrochemical activity. We have also performed density functional theory (DFT) simulations to qualitatively support our experimental observations by investigating the interactions and charge-transfer mechanism of glucose on MoO3. There is a strong interaction between glucose and the MoO3 surface due to charge transfer from a bonded O atom of glucose to a Mo atom of MoO3 resulting in a strong hybridization between the p orbital of O and d orbital of Mo. Thus, the MoO3 nanorod-based electrodes are found to be good glucose sensing materials for practical industrial applications.

  19. Scaffold microstructure effects on functional and mechanical performance: Integration of theoretical and experimental approaches for bone tissue engineering applications.

    Science.gov (United States)

    Cavo, Marta; Scaglione, Silvia

    2016-11-01

    The really nontrivial goal of tissue engineering is combining all scaffold micro-architectural features, affecting both fluid-dynamical and mechanical performance, to obtain a fully functional implant. In this work we identified an optimal geometrical pattern for bone tissue engineering applications, best balancing several graft needs which correspond to competing design goals. In particular, we investigated the occurred changes in graft behavior by varying pore size (300μm, 600μm, 900μm), interpore distance (equal to pore size or 300μm fixed) and pores interconnection (absent, 45°-oriented, 90°-oriented). Mathematical considerations and Computational Fluid Dynamics (CFD) tools, here combined in a complete theoretical model, were carried out to this aim. Poly-lactic acid (PLA) based samples were realized by 3D printing, basing on the modeled architectures. A collagen (COL) coating was also realized on grafts surface and the interaction between PLA and COL, besides the protein contribution to graft bioactivity, was evaluated. Scaffolds were extensively characterized; human articular cells were used to test their biocompatibility and to evaluate the theoretical model predictions. Grafts fulfilled both the chemical and physical requirements. Finally, a good agreement was found between the theoretical model predictions and the experimental data, making these prototypes good candidates for bone graft replacements. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Both functional LTbeta receptor and TNF receptor 2 are required for the development of experimental cerebral malaria.

    Directory of Open Access Journals (Sweden)

    Dieudonnée Togbe

    Full Text Available BACKGROUND: TNF-related lymphotoxin alpha (LTalpha is essential for the development of Plasmodium berghei ANKA (PbA-induced experimental cerebral malaria (ECM. The pathway involved has been attributed to TNFR2. Here we show a second arm of LTalpha-signaling essential for ECM development through LTbeta-R, receptor of LTalpha1beta2 heterotrimer. METHODOLOGY/PRINCIPAL FINDINGS: LTbetaR deficient mice did not develop the neurological signs seen in PbA induced ECM but died at three weeks with high parasitaemia and severe anemia like LTalphabeta deficient mice. Resistance of LTalphabeta or LTbetaR deficient mice correlated with unaltered cerebral microcirculation and absence of ischemia, as documented by magnetic resonance imaging and angiography, associated with lack of microvascular obstruction, while wild-type mice developed distinct microvascular pathology. Recruitment and activation of perforin(+ CD8(+ T cells, and their ICAM-1 expression were clearly attenuated in the brain of resistant mice. An essential contribution of LIGHT, another LTbetaR ligand, could be excluded, as LIGHT deficient mice rapidly succumbed to ECM. CONCLUSIONS/SIGNIFICANCE: LTbetaR expressed on radioresistant resident stromal, probably endothelial cells, rather than hematopoietic cells, are essential for the development of ECM, as assessed by hematopoietic reconstitution experiment. Therefore, the data suggest that both functional LTbetaR and TNFR2 signaling are required and non-redundant for the development of microvascular pathology resulting in fatal ECM.

  1. Optimal electron irradiation as a tool for functionalization of MoS{sub 2}: Theoretical and experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Karmakar, Debjani, E-mail: karmakar.debjani@gmail.com; Padma, N.; Ghosh, M.; Kaur, M.; Chandrasekhar Rao, T. V. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Halder, Rumu; Abraham, Geogy [Material Science Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Vaibhav, K. [Computer Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bhattacharya, D. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-04-07

    We demonstrate the utility of electron irradiation as a tool to enhance device functionality of graphene-analogous MoS{sub 2}. With the help of first-principles based calculations, vacancy-induced changes of various electronic properties are shown to be a combined result of crystal-field modification and spin-orbital coupling. A comparative theoretical study of various possible vacancy configurations both in bulk and monolayer MoS{sub 2} and related changes in their respective band-structures help us to explain plausible irradiation induced effects. Experimentally, various structural forms of MoS{sub 2} in bulk, few layered flakes, and nanocrystals are observed to exhibit important modification of their magnetic, transport, and vibrational properties, following low doses of electron irradiation. While irradiated single crystals and nanocrystals show an enhanced magnetization, transport properties of few-layered devices show a significant increase in their conductivity, which can be very useful for fabrication of electronic devices. Our theoretical calculations reveal that this increase in n-type conductivity and magnetization can be correlated with the presence of sulfur and molybdenum vacancies.

  2. Lung Functional and Biologic Responses to Variable Ventilation in Experimental Pulmonary and Extrapulmonary Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Samary, Cynthia S; Moraes, Lillian; Santos, Cintia L; Huhle, Robert; Santos, Raquel S; Ornellas, Debora S; Felix, Nathane S; Capelozzi, Vera L; Schanaider, Alberto; Pelosi, Paolo; de Abreu, Marcelo Gama; Rocco, Patricia R M; Silva, Pedro L

    2016-07-01

    The biologic effects of variable ventilation may depend on the etiology of acute respiratory distress syndrome. We compared variable and conventional ventilation in experimental pulmonary and extrapulmonary acute respiratory distress syndrome. Prospective, randomized, controlled experimental study. University research laboratory. Twenty-four Wistar rats. Acute respiratory distress syndrome was induced by Escherichia coli lipopolysaccharide administered intratracheally (pulmonary acute respiratory distress syndrome, n = 12) or intraperitoneally (extrapulmonary acute respiratory distress syndrome, n = 12). After 24 hours, animals were randomly assigned to receive conventional (volume-controlled ventilation, n = 6) or variable ventilation (n = 6). Nonventilated animals (n = 4 per etiology) were used for comparison of diffuse alveolar damage, E-cadherin, and molecular biology variables. Variable ventilation was applied on a breath-to-breath basis as a sequence of randomly generated tidal volume values (n = 600; mean tidal volume = 6 mL/kg), with a 30% coefficient of variation (normal distribution). After randomization, animals were ventilated for 1 hour and lungs were removed for histology and molecular biology analysis. Variable ventilation improved oxygenation and reduced lung elastance compared with volume-controlled ventilation in both acute respiratory distress syndrome etiologies. In pulmonary acute respiratory distress syndrome, but not in extrapulmonary acute respiratory distress syndrome, variable ventilation 1) decreased total diffuse alveolar damage (median [interquartile range]: volume-controlled ventilation, 12 [11-17] vs variable ventilation, 9 [8-10]; p ventilation, 21.5 [18.3-23.3] vs variable ventilation, 5.6 [4.6-12.1]; p ventilation, 2.0 [1.3-2.1] vs variable ventilation, 0.7 [0.6-1.4]; p ventilation, 0.3 [0.2-0.5] vs variable ventilation, 0.8 [0.5-1.3]; p ventilation increased vascular cell adhesion molecule-1 messenger RNA expression (volume

  3. Experimental and theoretical investigation of the effect of SiO2 content in gate dielectrics on work function shift induced by nanoscale capping layers

    KAUST Repository

    Caraveo-Frescas, J. A.

    2012-09-10

    The impact of SiO2 content in ultrathin gate dielectrics on the magnitude of the effective work function (EWF) shift induced by nanoscale capping layers has been investigated experimentally and theoretically. The magnitude of the effective work function shift for four different capping layers (AlN, Al2O3, La2O3, and Gd2O3) is measured as a function of SiO2 content in the gate dielectric. A nearly linear increase of this shift with SiO2 content is observed for all capping layers. The origin of this dependence is explained using density functional theory simulations.

  4. Surface modification of carbon nanotubes using 3-aminopropyltriethoxysilane to improve mechanical properties of nanocomposite based polymer matrix: Experimental and Density functional theory study

    Science.gov (United States)

    Hamed Mashhadzadeh, A.; Fereidoon, Ab.; Ghorbanzadeh Ahangari, M.

    2017-10-01

    In current study we combined theoretical and experimental studies to evaluate the effect of functionalization and silanization on mechanical behavior of polymer-based/CNT nanocomposites. Epoxy was selected as thermoset polymer, polypropylene and poly vinyl chloride were selected as thermoplastic polymers. The whole procedure is divided to two sections . At first we applied density functional theory (DFT) to analyze the effect of functionalization on equilibrium distance and adsorption energy of unmodified, functionalized by sbnd OH group and silanized epoxy/CNT, PP/CNT and PVC/CNT nanocomposites and the results showed that functionalization increased adsorption energy and reduced the equilibrium distance in all studied nanocomposites and silanization had higher effect comparing to OH functionalizing. Then we prepared experimental samples of all mentioned nanocomposites and tested their tensile and flexural strength properties. The obtained results showed that functionalization increased the studied mechanical properties in all evaluated nanocomposites. Finally we compared the results of experimental and theoretical sections with each other and estimated a suitable agreement between these parts.

  5. Anatomy of the sphenopalatine artery and its implications for transnasal neurosurgery.

    Science.gov (United States)

    Eordogh, M; Grimm, A; Gawish, I; Patonay, L; Reisch, R; Briner, H R; Baksa, G

    2017-11-22

    The knowledge of sinonasal vasculature is inevitable in transnasal neurosurgery. We performed an anatomical study on the sphenopalatine artery from the perspective of skull base procedures. To analyse the anatomical landmarks of the sphenopalatine artery, arterial skull corrosion casts (26 head halves) underwent endoscopic transnasal phantom surgery. Furthermore, we performed microsurgical dissection on formaldehyde-fixated cadavers with arterial perfusion (14 head halves) as well as studied Cone Beam CT-scans of anonymised patients and cadavers (115 head sides). In our cadaveric material, the sphenopalatine foramen is located at the transition of the superior and middle nasal meatus (95.0%) or in the superior nasal meatus (5.0%). It is the main entry point of the branches of the sphenopalatine artery into the nasal cavity. In most cadaveric cases (25.0%), at this level there are 2 branches superiorly and 1 vessel inferiorly to the ethmoid crest. An average of 2.4 vessels leave the sphenopalatine foramen superiorly to the ethmoid crest, 97.8% of them belong to the sphenopalatine arterys posterior septal branches. An average of 2.1 branches leave the sphenopalatine foramen inferiorly to the ethmoid crest; all of them belong to the posterior lateral nasal branches. There are no cases with a single artery at the plane of the sphenopalatine foramen. We describe a triangular bony structure bordering the sphenopalatine foramen anteriorly which is built up by the palatine and ethmoid bone as well as the maxilla. According to the radiographic studies, this triangular prominence is surrounded superiorly by a posterior ethmoid cell (57.4%), the sphenoid sinus (41.7%) or the orbit (0.9%) with a varying contribution of the superior nasal meatus; inferolaterally by the maxillary sinus (98.3%) or the pterygopalatine and infratemporal fossa (1.7%) and inferomedially by the middle nasal meatus. The medial vertex of the bony triangle corresponds to the ethmoid crest of the palatine

  6. Uso de dexmedetomidina em neurocirurgia Uso de dexmedetomidina en neurocirugía The use of dexmedetomidine in neurosurgery

    Directory of Open Access Journals (Sweden)

    Bernardo Aloisio Grings Herbert

    2007-04-01

    aneurisma y la retirada de tumores va en aumento. Además, su uso en intervenciones quirúrgicas funcionales es promisorio.BACKGROUND AND OBJECTIVES: The use of alpha2-adrenergic agonists is increasingly more frequent in Anesthesiology, as adjuvant or the sole anesthetic drug. Currently, dexmedetomidine is gaining popularity due to its greater selectivity for the alpha2-adrenergic receptors and its pharmacokinetic profile. The aim of this review was to analyze the use of dexmedetomidine in neurosurgery. CONTENTS: Besides considerations and review of the literature regarding the use of dexmedetomidine, specifically in neurosurgical procedures, its effects on the different organ systems are described. CONCLUSIONS: The pharmacokinetic and pharmacodynamic profile of dexmedetomidine favors its use in several neurosurgical procedures. Its use in craniotomy for the treatment of aneurysms and tumor removal is recent. Besides, its use in functional surgical interventions is promising.

  7. Impact of a Vascular Neurosurgery Simulation-Based Course on Cognitive Knowledge and Technical Skills in European Neurosurgical Trainees.

    Science.gov (United States)

    Zammar, Samer G; El Tecle, Najib E; El Ahmadieh, Tarek Y; Adelson, P David; Veznedaroglu, Erol; Surdell, Daniel L; Harrop, James S; Benes, Vladimir; Rezai, Ali R; Resnick, Daniel K; Bendok, Bernard R

    2015-08-01

    To assess microsurgical and diagnostic cerebral angiography modules and their corresponding objective assessment scales as educational tools for European neurosurgical residents at the European Association of Neurosurgical Societies Resident Vascular Neurosurgery course, which was held in Prague, Czech Republic, on September 2013. Microsurgical skills and cerebral angiography are fundamental skills in vascular neurosurgery. There is a need to develop a simulation-based curriculum focusing on these skills for neurosurgical trainees worldwide. The course consisted of 2 modules: microanastomosis and diagnostic cerebral angiography. In addition to an initial screening survey, each module was divided into 3 components: 1) a before didactic cognitive knowledge and technical skills testing, 2) a didactic lecture, and 3) an after didactic cognitive knowledge and technical skills testing. We compared the trainees' cognitive and technical scores from the before and after testing phases. Wilcoxon sum rank test was used to test statistical significance. The knowledge test median scores increased from 63% and 68% to 80% and 88% (P technical proficiency. Copyright © 2015. Published by Elsevier Inc.

  8. Topical vancomycin to reduce surgical-site infections in neurosurgery: Study protocol for a multi-center, randomized controlled trial.

    Science.gov (United States)

    Jonokuchi, Alexander J; Knopman, Jared; Radwanski, Ryan E; Martinez, Moises A; Taylor, Blake Eaton Samuel; Rothbaum, Michael; Sullivan, Sean; Robison, Trae R; Lo, Eric; Christophe, Brandon R; Bruce, Eliza M; Khan, Sabrina; Kellner, Christopher P; Sigounas, Dimitri; Youngerman, Brett; Bagiella, Emilia; Angevine, Peter D; Lowy, Franklin D; Sander Connolly, E

    2018-01-01

    Surgical-site infections (SSIs) account for 20% of all healthcare-associated infections, are the most common nosocomial infection among surgical patients, and are a focus of quality improvement initiatives. Despite implementation of many quality care measures (e.g. prophylactic antibiotics), SSIs remain a significant cause of morbidity, mortality, and economic burden, particularly in the field of neurosurgery. Topical vancomycin is increasingly utilized in instrumented spinal and cardiothoracic procedures, where it has been shown to reduce the risk of SSIs. However, a randomized controlled trial assessing its efficacy in the general neurosurgical population has yet to be done. The principle aim of "Topical Vancomycin for Neurosurgery Wound Prophylaxis" (NCT02284126) is to determine whether prophylactic, topical vancomycin reduces the risk of SSIs in the adult neurosurgical population. This prospective, multicenter, patient-blinded, randomized controlled trial will enroll patients to receive the standard of care plus topical vancomycin, or the standard of care alone. The primary endpoint of this study is a SSI by postoperative day (POD) 30. Patients must be over 18years of age. Patients are excluded for renal insufficiency, vancomycin allergy, and some ineligible procedures. Univariate analysis and logistic regression will determine the effect of topical vancomycin on SSIs at 30days. A randomized controlled trial is needed to determine the efficacy of this treatment. Results of this trial are expected to directly influence the standard of care and prevention of SSIs in neurosurgical patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. A real-time artifact reduction algorithm based on precise threshold during short-separation optical probe insertion in neurosurgery

    Directory of Open Access Journals (Sweden)

    Weitao Li

    2017-01-01

    Full Text Available During neurosurgery, an optical probe has been used to guide the micro-electrode, which is punctured into the globus pallidus (GP to create a lesion that can relieve the cardinal symptoms. Accurate target localization is the key factor to affect the treatment. However, considering the scattering nature of the tissue, the “look ahead distance (LAD” of optical probe makes the boundary between the different tissues blurred and difficult to be distinguished, which is defined as artifact. Thus, it is highly desirable to reduce the artifact caused by LAD. In this paper, a real-time algorithm based on precise threshold was proposed to eliminate the artifact. The value of the threshold was determined by the maximum error of the measurement system during the calibration procession automatically. Then, the measured data was processed sequentially only based on the threshold and the former data. Moreover, 100μm double-fiber probe and two-layer and multi-layer phantom models were utilized to validate the precision of the algorithm. The error of the algorithm is one puncture step, which was proved in the theory and experiment. It was concluded that the present method could reduce the artifact caused by LAD and make the real boundary sharper and less blurred in real-time. It might be potentially used for the neurosurgery navigation.

  10. Variable ventilation improves pulmonary function and reduces lung damage without increasing bacterial translocation in a rat model of experimental pneumonia.

    Science.gov (United States)

    de Magalhães, Raquel F; Samary, Cynthia S; Santos, Raquel S; de Oliveira, Milena V; Rocha, Nazareth N; Santos, Cintia L; Kitoko, Jamil; Silva, Carlos A M; Hildebrandt, Caroline L; Goncalves-de-Albuquerque, Cassiano F; Silva, Adriana R; Faria-Neto, Hugo C; Martins, Vanessa; Capelozzi, Vera L; Huhle, Robert; Morales, Marcelo M; Olsen, Priscilla; Pelosi, Paolo; de Abreu, Marcelo Gama; Rocco, Patricia R M; Silva, Pedro L

    2016-11-25

    Variable ventilation has been shown to improve pulmonary function and reduce lung damage in different models of acute respiratory distress syndrome. Nevertheless, variable ventilation has not been tested during pneumonia. Theoretically, periodic increases in tidal volume (VT) and airway pressures might worsen the impairment of alveolar barrier function usually seen in pneumonia and could increase bacterial translocation into the bloodstream. We investigated the impact of variable ventilation on lung function and histologic damage, as well as markers of lung inflammation, epithelial and endothelial cell damage, and alveolar stress, and bacterial translocation in experimental pneumonia. Thirty-two Wistar rats were randomly assigned to receive intratracheal of Pseudomonas aeruginosa (PA) or saline (SAL) (n = 16/group). After 24-h, animals were anesthetized and ventilated for 2 h with either conventional volume-controlled (VCV) or variable volume-controlled ventilation (VV), with mean VT = 6 mL/kg, PEEP = 5cmH2O, and FiO2 = 0.4. During VV, tidal volume varied randomly with a coefficient of variation of 30% and a Gaussian distribution. Additional animals assigned to receive either PA or SAL (n = 8/group) were not ventilated (NV) to serve as controls. In both SAL and PA, VV improved oxygenation and lung elastance compared to VCV. In SAL, VV decreased interleukin (IL)-6 expression compared to VCV (median [interquartile range]: 1.3 [0.3-2.3] vs. 5.3 [3.6-7.0]; p = 0.02) and increased surfactant protein-D expression compared to NV (2.5 [1.9-3.5] vs. 1.2 [0.8-1.2]; p = 0.0005). In PA, compared to VCV, VV reduced perivascular edema (2.5 [2.0-3.75] vs. 6.0 [4.5-6.0]; p < 0.0001), septum neutrophils (2.0 [1.0-4.0] vs. 5.0 [3.3-6.0]; p = 0.0008), necrotizing vasculitis (3.0 [2.0-5.5] vs. 6.0 [6.0-6.0]; p = 0.0003), and ultrastructural lung damage scores (16 [14-17] vs. 24 [14-27], p < 0.0001). Blood colony-forming-unit (CFU) counts

  11. Cancer treatment and gonadal function: experimental and established strategies for fertility preservation in children and young adults.

    Science.gov (United States)

    Anderson, Richard A; Mitchell, Rod T; Kelsey, Thomas W; Spears, Norah; Telfer, Evelyn E; Wallace, W Hamish B

    2015-07-01

    Preservation of gonadal function is an important priority for the long-term health of cancer survivors of both sexes and all ages at treatment. Loss of opportunity for fertility is a prime concern in both male and female cancer survivors, but endocrine effects of gonadal damage are likewise central to long-term health and wellbeing. Some fertility preservation techniques, such as semen and embryo cryopreservation, are established and successful in adults, and development of oocyte vitrification has greatly improved the potential to cryopreserve unfertilised oocytes. Despite being recommended for all pubertal male patients, sperm banking is not universally practised in paediatric oncology centres, and very few adolescent-friendly facilities exist. All approaches to fertility preservation have specific challenges in children and teenagers, including ethical, practical, and scientific issues. For young women, cryopreservation of ovarian cortical tissue with later replacement has resulted in at least 40 livebirths, but is still regarded as experimental in most countries. For prepubertal boys, testicular biopsy cryopreservation is offered in some centres, but how that tissue might be used in the future is unclear, and so far no evidence suggests that fertility can be restored. For both sexes, these approaches involve an invasive procedure and have an uncertain risk of tissue contamination in haematological and other malignancies. Decision making for all these approaches needs assessment of the individual's risk of fertility loss, and is made at a time of emotional distress. Development of this specialty needs better provision of information for patients and their medical teams, and improvements in service provision, to match technical and scientific advances. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    Roberta Hack Mendes

    2017-07-01

    Full Text Available Introduction: The purpose of this study was to investigate the effects of isolated vitamin B6 (VB6 supplementation on experimental hyperhomocysteinemia (Hhe induced by homocysteine thiolactone (HcyT. Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB6, HcyT, and HB6. On the 30th day of treatment, two groups were supplemented with VB6 in the drinking water (groups: CB6 and HB6. After 60 days of treatment, homocysteine (Hcy, cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2-like 2 (NRF2 and glutathione S-transferase (GST immunocontent, and superoxide dismutase (SOD, catalase (CAT, and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62% in relation to the CB6 group. Additionally, GST immunocontent was enhanced (51% in the HB6 group compared to the HcyT group. Also, SOD activity was lower (17% in the HB6 group compared to the CB6 group, and CAT activity was higher in the HcyT group (53% compared to the CB6 group. Ejection fraction (EF was improved in the HB6 group compared to the HcyT group. E/A ratio was enhanced in the HB6 group compared to the CB6 group. Correlations were found between CAT activity with myocardial performance index (MPI (r = 0.71; P = 0.06 and E/A ratio (r = 0.6; P = 0.01, and between EF and GST activity (r = 0.62; P = 0.02. Conclusions: These findings indicate that isolated VB6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters.   Keywords: Homocysteine; oxidative stress; vitamin B6.

  13. Functional genomics analysis of vitamin D effects on CD4+ T cells in vivo in experimental autoimmune encephalomyelitis ‬

    KAUST Repository

    Zeitelhofer, Manuel

    2017-02-15

    Vitamin D exerts multiple immunomodulatory functions and has been implicated in the etiology and treatment of several autoimmune diseases, including multiple sclerosis (MS). We have previously reported that in juvenile/adolescent rats, vitamin D supplementation protects from experimental autoimmune encephalomyelitis (EAE), a model of MS. Here we demonstrate that this protective effect associates with decreased proliferation of CD4+ T cells and lower frequency of pathogenic T helper (Th) 17 cells. Using transcriptome, methylome, and pathway analyses in CD4+ T cells, we show that vitamin D affects multiple signaling and metabolic pathways critical for T-cell activation and differentiation into Th1 and Th17 subsets in vivo. Namely, Jak/Stat, Erk/Mapk, and Pi3K/Akt/mTor signaling pathway genes were down-regulated upon vitamin D supplementation. The protective effect associated with epigenetic mechanisms, such as (i) changed levels of enzymes involved in establishment and maintenance of epigenetic marks, i.e., DNA methylation and histone modifications; (ii) genome-wide reduction of DNA methylation, and (iii) up-regulation of noncoding RNAs, including microRNAs, with concomitant down-regulation of their protein-coding target RNAs involved in T-cell activation and differentiation. We further demonstrate that treatment of myelin-specific T cells with vitamin D reduces frequency of Th1 and Th17 cells, down-regulates genes in key signaling pathways and epigenetic machinery, and impairs their ability to transfer EAE. Finally, orthologs of nearly 50% of candidate MS risk genes and 40% of signature genes of myelin-reactive T cells in MS changed their expression in vivo in EAE upon supplementation, supporting the hypothesis that vitamin D may modulate risk for developing MS.

  14. Thymic function and T cell parameters in a natural human experimental model of seasonal infectious diseases and nutritional burden

    Directory of Open Access Journals (Sweden)

    Morgan Gareth

    2011-06-01

    Full Text Available Abstract Background The study exploits a natural human experimental model of subsistence farmers experiencing chronic and seasonally modified food shortages and infectious burden. Two seasons existed, one of increased deprivation and infections (Jul-Dec, another of abundance and low infections (Jan-Jun; referred to as the hungry/high infection and harvest/low infection seasons respectively. Prior analysis showed a 10-fold excess in infectious disease associated mortality in young adults born in the hungry/high infection versus harvest/low infection season, and reduced thymic output and T cell counts in infancy. Here we report findings on the role of early life stressors as contributors to the onset of T cell immunological defects in later life. Methods We hypothesised that season of birth effects on thymic function and T cell immunity would be detectable in young adults since Kaplan-Meier survival curves indicated this to be the time of greatest mortality divergence. T cell subset analyses by flow-cytometry, sjTRECs, TCRVβ repertoire and telomere length by PCR, were performed on samples from 60 males (18-23 y selected to represent births in the hungry/high infection and harvest/low infection Results Total lymphocyte counts were normal and did not differ by birth season. CD3+ and CD4+ but not CD8+ counts were lower for those born during the hungry/high infection season. CD8+ telomere length also tended to be shorter. Overall, CD8+ TCRVβ repertoire skewing was observed with 'public' expressions and deletions seen in TCRVβ12/22 and TCRVβ24, respectively but no apparent effect of birth season. Conclusions We conclude that, although thymic function was unchanged, the CD4+ and CD3+ counts, and CD8+ telomere length results suggested that aspects of adult T cell immunity were under the influence of early life stressors. The endemicity of CMV and HBV suggested that chronic infections may modulate immunity through T cell repertoire development. The

  15. Transformation of Metal-Organic Frameworks/Coordination Polymers into Functional Nanostructured Materials: Experimental Approaches Based on Mechanistic Insights.

    Science.gov (United States)

    Lee, Kyung Joo; Lee, Jae Hwa; Jeoung, Sungeun; Moon, Hoi Ri

    2017-10-09

    Nanostructured materials such as porous metal oxides, metal nanoparticles, porous carbons, and their composites have been intensively studied due to their applications, including energy conversion and storage devices, catalysis, and gas storage. Appropriate precursors and synthetic methods are chosen for synthesizing the target materials. About a decade ago, metal-organic frameworks (MOFs) and coordination polymers (CPs) emerged as new precursors for these nanomaterials because they contain both organic and inorganic species that can play parallel roles as both a template and a precursor under given circumstances. Thermal conversions of MOFs offer a promising toolbox for synthesizing functional nanomaterials that are difficult to obtain using conventional methods. Although understanding the conversion mechanism is important for designing MOF precursors for the synthesis of nanomaterials with desired physicochemical properties, comprehensive discussions revealing the transformation mechanism remain insufficient. This Account reviews the utilization of MOFs/CPs as precursors and their transformation into functional nanomaterials with a special emphasis on understanding the relationship between the intrinsic nature of the parent MOFs and the daughter nanomaterials while discussing various experimental approaches based on mechanistic insights. We discuss nanomaterials categorized by materials such as metal-based nanomaterials and porous carbons. For metal-based nanomaterials transformed from MOFs, the nature of metal ions in the MOF scaffolds affects the physicochemical properties of the resultant materials including the phase, composite, and morphology of nanomaterials. Organic ligands are also involved in the in situ chemical reactions with metal species during thermal conversion. We describe these conversion mechanisms by classifying the phase of metal components in the resultant materials. Along with the metal species, carbon is a major element in MOFs, and thus

  16. Open questions in origin of life: experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach

    DEFF Research Database (Denmark)

    Adamala, K.; Anella, F.; Wieczorek, R.

    2014-01-01

    In this mini-review we present some experimental approaches to the important issue in the origin of life, namely the origin of nucleic acids and proteins with specific and functional sequences. The formation of macromolecules on prebiotic Earth faces practical and conceptual difficulties. From...

  17. Open questions in origin of life : Experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach

    NARCIS (Netherlands)

    Adamala, K.; Anella, F.M.; Wieczorek, R.; Stano, P.; Chiarabelli, C.; Luisi, P.L.

    2014-01-01

    In this mini-review we present some experimental approaches to the important issue in the origin of life, namely the origin of nucleic acids and proteins with specific and functional sequences. The formation of macromolecules on prebiotic Earth faces practical and conceptual difficulties. From the

  18. The role of Harvey Cushing and Walter Dandy in the evolution of modern neurosurgery in the Netherlands, illustrated by their correspondence Historical vignette

    NARCIS (Netherlands)

    Groen, Rob J. M.; Koehler, Peter J.; Kloet, Alfred

    The development of modern neurosurgery in the Netherlands, which took place in the 1920s, was highly influenced by the personal involvement of both Harvey Cushing and Walter Dandy, each in his own way. For the present article, the authors consulted the correspondence (kept at the Cushing/Whitney

  19. Experimental model of toxin-induced subclinical mastitis and its effect on disruption of follicular function in cows.

    Science.gov (United States)

    Furman, Ori; Leitner, Gabriel; Roth, Zvi; Lavon, Yaniv; Jacoby, Shamay; Wolfenson, David

    2014-11-01

    This study establishes an experimental model for subclinical mastitis induced by Gram-positive (G+) exosecretions of Staphylococcus aureus origin or Gram-negative (G-) endotoxin of Escherichia coli origin to examine its effects on follicular growth and steroid concentrations in Holstein dairy cows. Cows were synchronized with the Ovsynch protocol followed by a series of follicular cycles that included GnRH and PGF2α doses administered every 8 days. Cows received small intramammary doses of either G+ (10 μg, n = 10) or G- (0.5 μg, n = 6) toxin, or saline (n = 6; uninfected control) every 48 hours for 20 days. Follicular fluids were aspirated from preovulatory follicles before (aspiration one: control), at the end of (aspiration two: immediate effect), and 16 days after the end of (aspiration three: carryover effect) toxin exposure. During the 3 weeks of subclinical mastitis induced by G+ or G-, no local inflammatory signs were detected in the mammary gland and no systemic symptoms were noted: body temperatures of the treated cows did not differ from controls; plasma cortisol and haptoglobin concentrations were not elevated and did not differ among groups. Somatic cell count was higher in the treated groups than in controls, and higher in the G- versus G+ group. For analysis of reproductive responses, cows were further classified as nonaffected or affected based on an more than 20% decline in follicular androstenedione concentration in aspiration two or three relative to the first, control aspiration. Most G- (5/6) and 40% of G+ (4/10) cows were defined as affected by induced mastitis. An immediate decrease in the number of medium-size follicles was recorded on Day 4 of the induced cycle, toward the end of the 20-day mastitis induction, in the affected G+ compared with uninfected control group (1.0 ± 0.5 vs. 3.0 ± 0.4 follicles; P subclinical IMI induced by G+ or G- toxin disrupts follicular functions, and it seems that the ovarian pool of early antral follicles

  20. [Klaus Joachim Zülch: Partner to neurosurgery, advocate of neurology and the neuropathological basis].

    Science.gov (United States)

    Mennel, H D

    2002-01-01

    well be compared to the team formed by Harvey Cushing and Percieval Bailey. Their respective philosophies were equally identical, namely to classify tumors of the central nervous system through a pragmatic approach that would facilitate the communication between neuropathologist, neurosurgeon, neurologist and of course be ultimately as helpful as possible to the patient. Since 1959 Zülchs research turned to the topics of brain hypoxia, circulatory disturbances and stroke, notwithstanding that his interest remained with the other items, whenever new or old questions came up. The occupation with tumors became even once more intense when the WHO installed a reference center for brain tumor classification at his place in Cologne. In the new field of brain circulation, Klaus Joachim Zülch tried once again to bring basic science and clinical practise together and to draw the neurologists attention upon these frequent and important conditions, a development that gained increasing importance under the heading of "stroke unit" in our days. Klaus Joachim Zülch therefore may be regarded as neurologist ahead of his time trying to cover the epidemiologically important and frequent themes and establishing equal partnership with neurosurgery The connection with the scientific basis, i.e. morphology in different variations at the time under a common roof was crucial in his understanding of the work as neurologist.

  1. Launching Effectiveness Research to Guide Practice in Neurosurgery: A National Institute Neurological Disorders and Stroke Workshop Report.

    Science.gov (United States)

    Walicke, Patricia; Abosch, Aviva; Asher, Anthony; Barker, Fred G; Ghogawala, Zoher; Harbaugh, Robert; Jehi, Lara; Kestle, John; Koroshetz, Walter; Little, Roderick; Rubin, Donald; Valadka, Alex; Wisniewski, Stephen; Chiocca, E Antonio

    2017-04-01

    This workshop addressed challenges of clinical research in neurosurgery. Randomized controlled clinical trials (RCTs) have high internal validity, but often insufficiently generalize to real-world practice. Observational studies are inclusive but often lack sufficient rigor. The workshop considered possible solutions, such as (1) statistical methods for demonstrating causality using observational data; (2) characteristics required of a registry supporting effectiveness research; (3) trial designs combining advantages of observational studies and RCTs; and (4) equipoise, an identified challenge for RCTs. In the future, advances in information technology potentially could lead to creation of a massive database where clinical data from all neurosurgeons are integrated and analyzed, ending the separation of clinical research and practice and leading to a new "science of practice." Copyright © 2017 by the Congress of Neurological Surgeons.

  2. Speaking Secrets: Epilepsy, Neurosurgery, and Patient Testimony in the Age of the Explorable Brain, 1934-1960.

    Science.gov (United States)

    Elder, Rachel

    2015-01-01

    This article examines the role of Wilder Penfield's patients in early neurosurgeries for epilepsy at the Montreal Neurological Institute from the 1930s to 1950s. Shifting the focus from scientific discoveries that emerged as a result of Penfield's unprecedented "exploration" of the brain, this piece considers how patients contributed to the creation of such knowledge through their spoken feedback, both within and beyond the operating room. Correspondingly, it examines the personal and social contexts under which patients elected for surgery. Tracing an underexplored social history of Penfield's patients through more than sixty clinical records, it suggests that making knowledge about the brain was a multidirectional process in which patients meaningfully participated, and in which their experiences of epilepsy and motivations for surgery were significant.

  3. Is the medicolegal issue avoidable in neurosurgery? A retrospective survey of a series of 115 medicolegal cases from public hospitals.

    Science.gov (United States)

    Emery, Evelyne; Balossier, Anne; Mertens, Patrick

    2014-02-01

    Since the mid-1950s, neurosurgery has benefited from the remarkable progress due to tremendous advances in neuroimaging techniques, neuroanesthesia, neurostimulation, and brain-computer interfaces, as well as breakthroughs in operating microscopes and surgical instruments. Yet, this specialty has to do with delicate human structures and is hence considered as highly risky by insurance companies. In France, although neurosurgery's casualty rate (6%) is lower than in other specialties, the number of legal prosecutions has increased since 2002 because of easier access to medicolegal procedures. In order to avoid patients' resorting to the law courts, it becomes necessary to clearly identify the risk factors. From the data bank of the insurer Société Hospitalière d'Assurances Mutuelles (SHAM, main insurance company for public hospitals in France), we retrospectively analyzed 115 files (34 cranial and 81 spinal surgeries) covering the period 1997-2007 for the reasons for complaints against French neurosurgeons working in public hospitals. Five main causes were identified: surgical site infection (37%), technical error (22%), lack of information (14%), delayed diagnosis (11%), and lack of supervision (9%). Some causes are definitely avoidable at no cost to the hospital. Besides basic preventive safety procedures, we reiterate the mandatory steps for a good defense when being prosecuted. The evolution of patients' attitudes toward medical institutions observed in most countries has forced surgeons to adapt their practice. In this context, a common action certified by learned societies on sustainable health care quality, patient safety, and respect of good practices appears as the golden path to maintain a favorable legal, insurance, and financial environment. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Intravenous and oral levetiracetam in patients with a suspected primary brain tumor and symptomatic seizures undergoing neurosurgery: the HELLO trial.

    Science.gov (United States)

    Bähr, Oliver; Hermisson, Mirjam; Rona, Sabine; Rieger, Johannes; Nussbaum, Susanne; Körtvelyessy, Peter; Franz, Kea; Tatagiba, Marcos; Seifert, Volker; Weller, Michael; Steinbach, Joachim P

    2012-02-01

    Levetiracetam (LEV) is a newer anticonvulsant with a favorable safety profile. There seem to be no relevant drug interactions, and an intravenous formulation is available. Therefore, LEV might be a suitable drug for the perioperative anticonvulsive therapy of patients with suspected brain tumors undergoing neurosurgery. In this prospective study (NCT00571155) patients with suspected primary brain tumors and tumor-related seizures were perioperatively treated with oral and intravenous LEV up to 4 weeks before and until 4 weeks after a planned neurosurgical procedure. Thirty patients with brain tumor-related seizures and intended neurosurgery were included. Three patients did not undergo the scheduled surgery after enrollment, and two patients were lost to follow-up. Therefore, 25 patients were fully evaluable. After initiation of therapy with LEV, 100% of the patients were seizure-free in the pre-surgery phase (3 days up to 4 weeks before surgery), 88% in the 48 h post-surgery phase and 84% in the early follow-up phase (48 h to 4 weeks post surgery). Treatment failure even after dose escalation to 3,000 mg/day occurred in three patients. No serious adverse events related to the treatment with LEV occurred. Our data show the feasibility and safety of oral and intravenous LEV in the perioperative treatment of tumor-related seizures. Although this was a single arm study, the efficacy of LEV appears promising. Considering the side effects and interactions of other anticonvulsants, LEV seems to be a favorable option in the perioperative treatment of brain tumor-related seizures.

  5. The role of fluoxetine on macrophage function in chronic pain (Experimental study in Balb/c mice

    Directory of Open Access Journals (Sweden)

    Dwi Pudjonarko

    2015-11-01

    Full Text Available Chronic pain raises stress conditions such as depression that can lower the cellular immunity. Fluoxetine is an antidepressant  used as an adjuvant in pain management but no one has been linked it with the body immune system. The objectives of this research were to proof the benefits of fluoxetine in  preventing degradation of macrophage function in chronic pain by measuring the macrophage phagocytic index , macrophage NO levels and the liver bacterial count in BALB/c mice infected with Listeria Monocytogenes.A Post Test - Only Control Group Design was conducted using 28 male mice strain BALB /c, age 8-10 weeks. The control group (C, mice got the same standard feed as the other groups. Chronic pain group (P, mice were injected with 20μL intraplantar CFA on day-1. Pain + fluoxetine early group (PFE were treated with P + fluoxetine 5 mg / kg ip day-1, the 4th, the 7th and the 10th, while the Pain + fluoxetine late group (PFL were treated with P + fluoxetine 5 mg / kg ip on day 7th and 10th. All mice were injected with 104 live Listeria monocytogenes iv on day 8th. Termination was performed on day 13th. Differences within groups  were analyzed using  One-way ANOVA and Kruskall Wallis, whereas the correlation of variables were analyzed using  Pearson's product moment. The experimental results showed that The macrophage phagocytic index and NO macrophage level (pg/mL in PFE group(2,24±1,013; 0,24±0,239 was higher than than P group (1,68±0,920; 0,21±0,263 and there was no different in the macrophage phagocytic index of PFE group compared to C group (p=0,583; p=0,805. In PFL group (4,32±1,459; 0,54±0,294 the macrophage phagocytic index as well as NO macrophage level (pg/mL was higher than P group (1,68±0,920; 0,21±0,263 with p=0,002; p=0,017. P group Bacterial count (log cfu/gram (2,30±0,849 was significantly higher than C group(1,15±0,223 (p=0,007, while PFE group bacterial count (1,96±0,653 and PFL group bacterial count (1,84±0

  6. Functional significance of shade-induced leaf senescence in dense canopies: an experimental test using transgenic tobacco

    NARCIS (Netherlands)

    Boonman, A.; Anten, N.P.R.; Dueck, T.A.; Jordi, W.J.R.M.; Werf, van der A.K.; Voesenek, L.A.C.J.; Pons, T.L.

    2006-01-01

    Canopy photosynthesis models have predicted an optimal leaf area index (LAI; leaf area per unit surface area) and leaf nitrogen distribution at which whole-plant carbon gain per unit N is maximized. In this study we experimentally tested these models, using transgenic PSAG12-IPT tobacco (SAG;

  7. The effect of experimental low back pain on lumbar muscle activity in people with a history of clinical low back pain: a muscle functional MRI study.

    Science.gov (United States)

    Danneels, Lieven; Cagnie, Barbara; D'hooge, Roseline; De Deene, Yves; Crombez, Geert; Vanderstraeten, Guy; Parlevliet, Thierry; Van Oosterwijck, Jessica

    2016-02-01

    In people with a history of low back pain (LBP), structural and functional alterations have been observed at several peripheral and central levels of the sensorimotor pathway. These existing alterations might interact with the way the sensorimotor system responds to pain. We examined this assumption by evaluating the lumbar motor responses to experimental nociceptive input of 15 participants during remission of unilateral recurrent LBP. Quantitative T2 images (muscle functional MRI) were taken bilaterally of multifidus, erector spinae, and psoas at several segmental levels (L3 upper and L4 upper and lower endplate) and during several conditions: 1) at rest, 2) upon trunk-extension exercise without pain, and 3) upon trunk-extension exercise with experimental induced pain at the clinical pain-side (1.5-ml intramuscular hypertonic saline injections in erector spinae). Following experimental pain induction, muscle activity levels similarly reduced for all three muscles, on both painful and nonpainful sides, and at multiple segmental levels (P = 0.038). Pain intensity and localization from experimental LBP were similar as during recalled clinical LBP episodes. In conclusion, unilateral and unisegmental experimental LBP exerts a generalized and widespread decrease in lumbar muscle activity during remission of recurrent LBP. This muscle response is consistent with previous observed patterns in healthy people subjected to the same experimental pain paradigm. It is striking that similar inhibitory patterns in response to pain could be observed, despite the presence of preexisting alterations in the lumbar musculature during remission of recurrent LBP. These results suggest that motor output can modify along the course of recurrent LBP. Copyright © 2016 the American Physiological Society.

  8. Experimental evidence that simplified forest structure interacts with snow cover to influence functional connectivity for Pacific martens

    Science.gov (United States)

    Katie M. Moriarty; Clinton W. Epps; Matthew G. Betts; Dalton J. Hance; J. D. Bailey; William J. Zielinski

    2015-01-01

    Context Functional connectivity—the facilitation of individual movements among habitat patches—is essential for species’ persistence in fragmented landscapes. Evaluating functional connectivity is critical for predicting range shifts, developing conservation plans, and anticipating effects of disturbance, especially for species affected by climate change. Objectives We...

  9. Virtualized Network Function Orchestration System and Experimental Network Based QR Recognition for a 5G Mobile Access Network

    Directory of Open Access Journals (Sweden)

    Misun Ahn

    2017-12-01

    Full Text Available This paper proposes a virtualized network function orchestration system based on Network Function Virtualization (NFV, one of the main technologies in 5G mobile networks. This system should provide connectivity between network devices and be able to create flexible network function and distribution. This system focuses more on access networks. By experimenting with various scenarios of user service established and activated in a network, we examine whether rapid adoption of new service is possible and whether network resources can be managed efficiently. The proposed method is based on Bluetooth transfer technology and mesh networking to provide automatic connections between network machines and on a Docker flat form, which is a container virtualization technology for setting and managing key functions. Additionally, the system includes a clustering and recovery measure regarding network function based on the Docker platform. We will briefly introduce the QR code perceived service as a user service to examine the proposal and based on this given service, we evaluate the function of the proposal and present analysis. Through the proposed approach, container relocation has been implemented according to a network device’s CPU usage and we confirm successful service through function evaluation on a real test bed. We estimate QR code recognition speed as the amount of network equipment is gradually increased, improving user service and confirm that the speed of recognition is increased as the assigned number of network devices is increased by the user service.

  10. Cartilage damage and bone erosion are more prominent determinants of functional impairment in longstanding experimental arthritis than synovial inflammation

    Directory of Open Access Journals (Sweden)

    Silvia Hayer

    2016-11-01

    Full Text Available Chronic inflammation of articular joints causing bone and cartilage destruction consequently leads to functional impairment or loss of mobility in affected joints from individuals affected by rheumatoid arthritis (RA. Even successful treatment with complete resolution of synovial inflammatory processes does not lead to full reversal of joint functionality, pointing to the crucial contribution of irreversibly damaged structural components, such as bone and cartilage, to restricted joint mobility. In this context, we investigated the impact of the distinct components, including synovial inflammation, bone erosion or cartilage damage, as well as the effect of blocking tumor necrosis factor (TNF on functional impairment in human-TNF transgenic (hTNFtg mice, a chronic inflammatory erosive animal model of RA. We determined CatWalk-assisted gait profiles as objective quantitative measurements of functional impairment. We first determined body-weight-independent gait parameters, including maximum intensity, print length, print width and print area in wild-type mice. We observed early changes in those gait parameters in hTNFtg mice at week 5 – the first clinical signs of arthritis. Moreover, we found further gait changes during chronic disease development, indicating progressive functional impairment in hTNFtg mice. By investigating the association of gait parameters with inflammation-mediated joint pathologies at different time points of the disease course, we found a relationship between gait parameters and the extent of cartilage damage and bone erosions, but not with the extent of synovitis in this chronic model. Next, we observed a significant improvement of functional impairment upon blocking TNF, even at progressed stages of disease. However, blocking TNF did not restore full functionality owing to remaining subclinical inflammation and structural microdamage. In conclusion, CatWalk gait analysis provides a useful tool for quantitative

  11. The effectiveness of telehealth care on caregiver burden, mastery of stress, and family function among family caregivers of heart failure patients: a quasi-experimental study.

    Science.gov (United States)

    Chiang, Li-Chi; Chen, Wan-Chou; Dai, Yu-Tzu; Ho, Yi-Lwun

    2012-10-01

    Telehealth care was developed to provide home-based monitoring and support for patients with chronic disease. The positive effects on physical outcome have been reported; however, more evidence is required concerning the effects on family caregivers and family function for heart failure patients transitioning from the hospital to home. To evaluate the effectiveness of nursing-led transitional care combining discharge plans and telehealth care on family caregiver burden, stress mastery and family function in family caregivers of heart failure patients compared to those receiving traditional discharge planning only. This is a quasi-experimental study design. Sixty-three patients with heart failure were assessed for eligibility and invited to participate in either telehealth care or standard care in a medical centre from May to October 2010. Three families refused to participate in data collection. Thirty families who chose telehealth care after discharge from the hospital to home comprised the experimental group; the others families receiving discharge planning only comprised the comparison group. Telenursing specialist provided the necessary family nursing interventions by 24-h remote monitoring of patients' health condition and counselling by telephone, helping the family caregivers successfully transition from hospital to home. Data on caregiver burden, stress mastery and family function were collected before discharge from the hospital and one month later at home. Effects of group, time, and group×time interaction were analysed using Mixed Model in SPSS (17.0). Family caregivers in both groups had significantly lower burden, higher stress mastery, and better family function at one-month follow-up compared to before discharge. The total score of caregiver burden, stress mastery and family function was significantly improved for the family caregivers in the experimental group compared to the comparison group at posttest. Two subscales of family function

  12. Theoretical analysis based on fundamental functions of thin plate and experimental measurement for vibration characteristics of a plate coupled with liquid

    Science.gov (United States)

    Liao, Chan-Yi; Wu, Yi-Chuang; Chang, Ching-Yuan; Ma, Chien-Ching

    2017-04-01

    This study combined theoretical, experimental, and numerical analysis to investigate the vibration characteristics of a thin rectangular plate positioned horizontally at the bottom of a rectangular container filled with liquid. Flow field pressure was derived using an equation governing the behavior of incompressible fluids. Analytic solutions to vibrations in a thin plate in air served as the fundamental function of the thin plate coupled with liquid. We then used liquid pressure, and the out-of-plane deflection of the thin plate for the construction of frequency response functions for the analysis of vibration characteristics in the liquid-plate coupling system. Two experimental methods were employed to measure the vibration characteristics of the thin plate immersed in water. The first involved using sensors of polyvinylidene difluoride (PVDF) to measure transient signals of fluid-plate system subjected an impact at the thin plate. These were then converted to the frequency domain in order to obtain the resonant frequencies of the fluid-plate coupling system. The second method was amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI), which was used to measure the dynamic characteristics of the thin plate in the flow field. This method was paired with the image processing techniques, temporal speckle pattern interferometry (TSPI) and temporal standard deviation (TSTD), to obtain clear mode shapes of the thin plate and resonant frequencies. Comparison of the results from theoretical analysis, finite element method, and experimental measurements confirmed the accuracy of our theoretical analysis, which was superior to the conventional approach based on beam mode shape functions. The experimental methods proposed in this study can be used to measure the resonant frequencies of underwater thin plates, and clear mode shapes can be obtained using AF-ESPI. Our results indicate that the resonant frequencies of thin plates underwater are lower than

  13. Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. II. Findings in experimentally induced ureteric stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Rohrschneider, W.K.; Becker, K.; Hoffend, J.; Clorius, J.H.; Darge, K.; Kooijman, H.; Troeger, J. [Paediatric Radiology, Univ. of Heidelberg (Germany)

    2000-08-01

    Purpose. To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction in the piglet. Materials and methods. In 20 piglets unilateral ureteric stenosis was created operatively. Post-surgery repeated comparative examinations were obtained with MRU, diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US). MRU was performed as a combination study with a static 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA with frusemide administration. Results. MRU allowed complete depiction of the prestenotic urinary tract and of the stenosis in all cases. In 43 comparative studies MRU was superior to EU in 36, EU to MRU in 2. When single kidney function was calculated with both MRU and DRS, results were highly correlated (r = 0.92). When urinary excretion was compared, significant agreement was achieved with concordant findings in 86 % and slightly discordant results in 12 %. Conclusions. Static-dynamic MR urography permits excellent depiction of experimentally induced urinary tract obstruction in piglets and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out - it does not require radiation and it permits functional-morphological correlation. (orig.)

  14. Code REX to fit experimental data to exponential functions and graphics plotting; Codigo REX para ajuste de datos experimentales a funciones exponenciales y su representacion grafica

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.; Travesi, A.

    1983-07-01

    The REX code, written in Fortran IV, performs the fitting a set of experimental data to different kind of functions as: straight-line (Y = A + BX) , and various exponential type (Y-A B{sup x}, Y=A X{sup B}; Y=A exp(BX) ) , using the Least Squares criterion. Such fitting could be done directly for one selected function of for the our simultaneously and allows to chose the function that best fitting to the data, since presents the statistics data of all the fitting. Further, it presents the graphics plotting, of the fitted function, in the appropriate coordinate axes system. An additional option allows also the Graphic plotting of experimental data used for the fitting. All the data necessary to execute this code are asked to the operator in the terminal screen, in the iterative way by screen-operator dialogue, and the values are introduced through the keyboard. This code could be executed with any computer provided with graphic screen and keyboard terminal, with a X-Y plotter serial connected to the graphics terminal. (Author) 5 refs.

  15. Coordination Mechanism in Fast Human Movements. Experimental and Modelling Studies. Volume 2.

    Science.gov (United States)

    1983-09-01

    Neurosurgery and Psychiatry, 1975. 38, . 1154-1162. . . . .. . . . . . . . . . . . p. sq.0 67. Harms, E. The origine and early history of electrotherapy ...Physical Medicine and * Rehabilitation, 1976, 57, 311-314. 100. Liberson, W.T., Holmquist, H.J., Scot, D., a nd Dow, M. ,.. ’c Functional electrotherapy ...1961. 42, 101-105. 101. Licht, S. History of electrotherapy . In Licht (ed) Therapeutic Electrioity and ultraviolet Radiation. New-Haven, Connecticut

  16. Effects of surgery and other experimental factors on the evaluation of middle ear function in gekkonoid lizards.

    Science.gov (United States)

    Werner, Y L; Igić, P G; Saunders, J C

    2001-10-01

    This study examines three artificial factors likely to cause variation between results from different investigations of auditory function, at least in lizards. Controlled tests were performed on gecko lizards, by external laser interferometry of the middle ear transfer function at the tympanic membrane (TM). In conclusion, studies of middle ear function should examine motion both at the insertion of the columella-extracolumella shaft onto the TM, and at the tip of the extracolumellar pars inferior, because the internal proportions and function of the extracolumellar lever vary among species. At least in scansorial geckos, auditory experiments may be conducted with the animal on its back, as this posture introduces no acoustic artifacts. Positioning the subject on its belly, with the throat resting on the substrate, imposes small but significant artifacts on middle ear function. Similar artifacts occur with the belly up but the throat loaded with a modeling clay plate. The surgical fenestration of the ventral throat wall, common in auditory studies on lizards, causes (at least in Eublepharis) artificial enhancement of sensitivity at low frequencies and erratic responses at high frequencies.

  17. Insulin-like growth factor 2 enhances regulatory T-cell functions and suppresses food allergy in an experimental model.

    Science.gov (United States)

    Yang, Gui; Geng, Xiao-Rui; Song, Jiang-Ping; Wu, Yingying; Yan, Hao; Zhan, Zhengke; Yang, Litao; He, Weiyi; Liu, Zhi-Qiang; Qiu, Shuqi; Liu, Zhigang; Yang, Ping-Chang

    2014-06-01

    The functions of regulatory T (Treg) cells are important in immunity, and the regulatory mechanisms of Treg cell activities are not fully understood yet. We sought to investigate the role of insulin-like growth factor (IGF) 2 in the upregulation of Treg cell function. The expression of insulin-like growth factor 2 receptor (IGF2R) on T cells was assessed by using flow cytometry. Treg cell functions were evaluated by assessing the suppressor effect on proliferation of other effector T (Teff) cells. The effect of IGF2 on regulating Treg cell functions were evaluated with a cell-culture model and a food allergy mouse model. Expression of IGF2R was observed in more than 90% of murine and human Treg cells but in less than 10% of effector CD4(+) T cells. Activation of IGF2R and T-cell receptor induced marked Treg cell proliferation and release of TGF-β from Treg cells, which enhanced Treg cell immune suppressor effects on other Teff cell activities and allergic inflammation in the intestine. Activation of IGF2R enhances Treg cell functions in suppressing other Teff cell activities and inhibiting allergic inflammation in the intestine. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  18. Anatase nanoparticle surface reactivity in NaCl media: a CD-MUSIC model interpretation of combined experimental and density functional theory studies.

    Science.gov (United States)

    Ridley, Moira K; Machesky, Michael L; Kubicki, James D

    2013-07-09

    The effect of particle size on the primary charging behavior of a suite of monodisperse nanometer diameter (4, 20, and 40 nm) anatase samples has been quantitatively examined with macroscopic experimental studies. The experimental results were evaluated using surface complexation modeling, which explicitly incorporated corresponding molecular-scale information from density functional theory (DFT) simulation studies. Potentiometric titrations were completed in NaCl media, at five ionic strengths (from 0.005 to 0.3 m), and over a wide pH range (3-11), at a temperature of 25 °C. From the experimental results, the pH of zero net proton charge (pHznpc) for the 4 and 20 nm diameter samples was 6.42, whereas the pHznpc was 6.22 for the 40 nm sample. The slopes of the net proton charge curves increased with an increase in particle size. Multisite surface complexation and charge distribution (CD) models, with a Basic Stern layer description of the electric double layer, were developed to describe all experimental data. Fits to the experimental data included an inner-sphere Na-bidentate species, an outer-sphere Na-monodentate species, and outer-sphere Cl-monodentate species. DFT simulations found the Na-bidentate species to be the most stable species on the (101) anatase surface (the predominant crystal face). The CD value for the Na-bidentate species was calculated using a bond valence interpretation of the DFT-optimized geometry. The Stern layer capacitance value varied systematically with particle size. The collective experimental and modeling studies show that subtle differences exist in the interface reactivity of nanometer diameter anatase samples. These results should help to further elucidate an understanding of the solid-aqueous solution interface reactivity of nanosized particles.

  19. Results of experimental testing of system of future physical culture teachers’ training for art pedagogic means’ application in pedagogic functioning

    Directory of Open Access Journals (Sweden)

    T.V. Nizhevska

    2015-10-01

    Full Text Available Purpose: the research is devoted to seeking of ways to rising of quality of future physical culture teachers. Material: in experiment 436 students and 29 teachers participated. Results: it was found that readiness of future physical culture teachers for application of art pedagogic means in professional functioning is achieved through realization of appropriate block system. Such system ensures mastering by students of the following: theoretical principles of art pedagogic; mastering of art pedagogic skills in teaching and quasi professional functioning; acquiring of practical experience of art means’ application in period of pedagogic practice at schools. It was also determined that training system of future teachers includes the following three blocks: conceptual-target, knowledge-procedural; control-correcting. Conclusions: it is recommended to use such criteria of students’ readiness for application of art means in pedagogic functioning: motivation-axiological, cognitive-active, personality’s-reflexive.

  20. Empagliflozin Prevents Worsening of Cardiac Function in an Experimental Model of Pressure Overload-Induced Heart Failure

    Directory of Open Access Journals (Sweden)

    Nikole J. Byrne, BSc

    2017-08-01

    Full Text Available This study sought to determine whether the sodium/glucose cotransporter 2 (SGLT2 inhibitor empagliflozin improved heart failure (HF outcomes in nondiabetic mice. The EMPA-REG OUTCOME (Empagliflozin, Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients trial demonstrated that empagliflozin markedly prevented HF and cardiovascular death in subjects with diabetes. However, despite ongoing clinical trials in HF patients without type 2 diabetes, there are no objective and translational data to support an effect of SGLT2 inhibitors on cardiac structure and function, particularly in the absence of diabetes and in the setting of established HF. Male C57Bl/6 mice were subjected to either sham or transverse aortic constriction surgery to induce HF. Following surgery, mice that progressed to HF received either vehicle or empagliflozin for 2 weeks. Cardiac function was then assessed in vivo using echocardiography and ex vivo using isolated working hearts. Although vehicle-treated HF mice experienced a progressive worsening of cardiac function over the 2-week treatment period, this decline was blunted in empagliflozin-treated HF mice. Treatment allocation to empagliflozin resulted in an improvement in cardiac systolic function, with no significant changes in cardiac remodeling or diastolic dysfunction. Moreover, isolated hearts from HF mice treated with empagliflozin displayed significantly improved ex vivo cardiac function compared to those in vehicle-treated controls. Empagliflozin treatment of nondiabetic mice with established HF blunts the decline in cardiac function both in vivo and ex vivo, independent of diabetes. These data provide important basic and translational clues to support the evaluation of SGLT2 inhibitors as a treatment strategy in a broad range of patients with established HF.

  1. Experimental study of the excitation functions of deuteron induced reactions on natSn up to 40 MeV

    Science.gov (United States)

    Tárkányi, F.; Ditrói, F.; Hermanne, A.; Takács, S.; Király, B.; Baba, M.; Ignatyuk, A. V.

    2011-02-01

    Using the stacked-foil activation technique, cross-sections of deuteron induced reactions on natural Sn were measured up to 40 MeV. Excitation functions are reported for the product nuclides 111In, 113Sn, 117mSn, 125mSn, 125gSn, 115Sb, 116mSb, 117Sb, 118mSb 120mSb, 122Sb, 124Sb and 125Sb and compared with the earlier published data sets. For all excitation functions comparisons with theoretical calculations using the ALICE-IPPE, EMPIRE, EAF and the TALYS codes were performed.

  2. Management of Subarachnoid Hemorrhage in Two Important Italian Political Leaders: A Paradigm of Ethical and Technological Evolution of Neurosurgery During the Past Half-Century.

    Science.gov (United States)

    Longatti, Pierluigi; Giombelli, Ermanno; Pavesi, Giacomo; Carteri, Alessandro; Feletti, Alberto

    2016-08-01

    For a curious and extraordinary coincidence, 5 of the 7 most relevant leaders of the Italian Communist Party (Partito Comunista Italiano, which was established in 1921, has been the biggest Communist Party in Western Countries) suffered a cerebral stroke. Cerebrovascular diseases afflicted also Stalin and Lenin, and a number of Presidents of the United States. We present the stories of 2 important Italian political leaders who shared both the leadership role of the major left Italian Party and the dramatic experience of a subarachnoid hemorrhage. Retracing their medical incidents, separated by 50 years of history, we show how a fatal medical disease has become neurosurgical and successfully cured thanks to the advances of neurosurgery, neuroradiology, and hospital organization. A neurologic disease that was disgraceful 50 years ago has lost any disquieting and embarrassing significance in the present time to the light of evolution of vascular neurosurgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Development of the ultra-miniaturized Inertial Measurement Unit WB3 for objective skill analysis and assessment in neurosurgery: preliminary results.

    Science.gov (United States)

    Zecca, Massimiliano; Sessa, Salvatore; Lin, Zhuohua; Suzuki, Takashi; Sasaki, Tomoya; Itoh, Kazuko; Iseki, Hiroshi; Takanishi, Atsuo

    2009-01-01

    In recent years there has been an ever increasing amount of research and development of technologies and methodologies aimed at improving the safety of advanced surgery. In this context, several training methods and metrics have been proposed, in particular for laparoscopy, both to improve the surgeon's abilities and also to assess her/his skills. For neurosurgery, however, the extremely small movements and sizes involved have prevented until now the development of similar methodologies and systems. In this paper we present the development of the ultra-miniaturized Inertial Measurement Unit WB3 (at present the smallest, lightest, and best performing in the world) for practical application in neurosurgery as skill assessment tool. This paper presents the feasibility study for quantitative discrimination of movements of experienced surgeons and beginners in a simple pick and place scenario.

  4. Determination of optimum experimental conditions for preparation and functional properties of hydroxypropylated, phosphorylated and hydroxypropyl-phosphorylated glutinous rice starch.

    Science.gov (United States)

    Yang, Liping; Zhou, Yibin; Zheng, Xiangyu; Wang, Haisong; Wang, Naifu

    2017-12-01

    Optimization of the preparation of hydroxypropylated, phosphorylated and hydroxypropyl-phosphorylated glutinous rice starch was performed using a response surface methodology comprising three variables at three levels. Multi-linear regression was used to fit the degree of substitution and molar substitution against. Optimal reaction conditions were 9h, 42°C, 10% (hydroxypropylated), 148min, 150°C, 7% (phosphorylated) and 95min, 140°C, 7.8% (hydroxypropyl-phosphorylated). For hydroxypropylated, predicted optimal and experimental molar substitution values were found to be identical: 0.20. Both the phosphorylated and hydroxypropyl-phosphorylated, the predicted optimal and experimental degree of substitution values was 0.02. Static rheological analysis revealed a pseudoplastic nature for native and modified starches and an increase in apparent viscosity following modification. Dynamic rheological analysis indicated an entanglement network system for native glutinous rice starch suspension, but weak elastic gel-like structure for modified starches as the storage modulus (G') exceeded the loss modulus (G"). Additionally, chemical modification improved the freeze-thaw stability, swelling power, solubility and paste clarity. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

    Energy Technology Data Exchange (ETDEWEB)

    Bau, Sebastien; Witschger, Olivier [Institut National de Recherche et de Securite, INRS, Laboratoire de Metrologie des Aerosols, Rue du Morvan, CS 60027, 54519 Vandoeuvre Cedex (France); Gensdarmes, Francois [Institut de Radioprotection et de Surete Nucleaire, IRSN, Laboratoire de Physique et de Metrologie des Aerosols, BP 68, 91192 Gif-sur-Yvette Cedex (France); Thomas, Dominique [Laboratoire des Sciences du Genie Chimique, LSGC/CNRS, Nancy Universite, BP 2041, 54001 Nancy Cedex (France)], E-mail: sebastien.bau@inrs.fr

    2009-05-01

    An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak{sup x2122} 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

  6. Influence of Prescribed Herbal and Western Medicine on Patients with Abnormal Liver Function Tests: A Retrospective Quasi-Experimental Study

    Science.gov (United States)

    Lee, Ah-Ram; Yim, Je-Min; Kim, Won-Il

    2012-01-01

    Objectives: The aim of this study was to investigate the safety and the efficacy of Korean herbal, western and combination medicine use in patients with abnormal liver function tests. Methods: We investigated nerve disease patients with abnormal liver function tests who were treated with Korean herbal, western and combination medicine at Dong-Eui University Oriental Hospital from January 2011 to August 2011. We compared aspartic aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (T-bil) levels before and after taking medicine and excluded patients who had liver-related disease when admitted. Results: AST and ALT were decreased significantly in patients who had taken herbal, western medicine. AST, ALT and ALP were decreased significantly in patients who had taken combination medicine. Compare to herbal medicine, AST, ALT and ALP were decreased significantly in patients who had taken western medicine, and ALT and ALP were decreased significantly in patients who had taken combination medicine. There were no significant differences between western and combination medicine. Conclusions: This study suggests that prescribed Korean herbal medicine, at least, does not injure liver function for patients’, moreover, it was shown to be effective in patients with abnormal liver function tests. PMID:25780634

  7. Influence of prescribed herbal and Western medicine on patients with abnormal liver function tests: a retrospective quasi-experimental study.

    Science.gov (United States)

    Lee, Ah-Ram; Yim, Je-Min; Kim, Won-Il

    2012-03-01

    The aim of this study was to investigate the safety and the efficacy of Korean herbal, western and combination medicine use in patients with abnormal liver function tests. We investigated nerve disease patients with abnormal liver function tests who were treated with Korean herbal, western and combination medicine at Dong-Eui University Oriental Hospital from January 2011 to August 2011. We compared aspartic aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (T-bil) levels before and after taking medicine and excluded patients who had liver-related disease when admitted. AST and ALT were decreased significantly in patients who had taken herbal, western medicine. AST, ALT and ALP were decreased significantly in patients who had taken combination medicine. Compare to herbal medicine, AST, ALT and ALP were decreased significantly in patients who had taken western medicine, and ALT and ALP were decreased significantly in patients who had taken combination medicine. There were no significant differences between western and combination medicine. This study suggests that prescribed Korean herbal medicine, at least, does not injure liver function for patients', moreover, it was shown to be effective in patients with abnormal liver function tests.

  8. Experimental non-alcoholic fatty liver disease results in decreased hepatic uptake transporter expression and function in rats

    NARCIS (Netherlands)

    Fisher, Craig D.; Lickteig, Andrew J.; Augustine, Lisa M.; Oude Elferink, Ronald P. J.; Besselsen, David G.; Erickson, Robert P.; Cherrington, Nathan J.

    2009-01-01

    Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of diagnoses ranging from simple fatty liver (SFL), to non-alcoholic steatohepatitis (NASH). This study aimed to determine the effect of moderate and severe NAFLD on hepatic transporter expression and function in vivo. Rats were fed a

  9. Influence of Prescribed Herbal and Western Medicine on Patients with Abnormal Liver Function Tests: A Retrospective Quasi-Experimental Study

    Directory of Open Access Journals (Sweden)

    Lee Ah-Ram

    2012-03-01

    Full Text Available Objectives: The aim of this study was to investigate the safety and the efficacy of Korean herbal, western and combination medicine use in patients with abnormal liver function tests. Methods: We investigated nerve disease patients with abnor-mal liver function tests who were treated with Korean herbal, western and combination medicine at Dong-Eui University Oriental Hospital from January 2011 to August 2011. We co-mpared aspartic aminotransferase (AST, alanine aminotran-sferase (ALT, alkaline phosphatase (ALP and total bilirubin (T-bil levels before and after taking medicine and excluded patients who had liver-related disease when admitted. Results: AST and ALT were decreased significantly in patients who had taken herbal, western medicine. AST, ALT and ALP were decreased significantly in patients who had taken comb-ination medicine. Compare to herbal medicine, AST, ALT and ALP were decreased significantly in patients who had taken western medicine, and ALT and ALP were decreased signifi-cantly in patients who had taken combination medicine. There were no significant differences between western and combin-ation medicine. Conclusions: This study suggests that prescribed Korean herbal medicine, at least, does not injure liver function for patients’, moreover, it was shown to be effective in patients with abnormal liver function tests.

  10. Severity of structural and functional right ventricular remodeling depends on training load in an experimental model of endurance exercise.

    Science.gov (United States)

    Sanz-de la Garza, Maria; Rubies, Cira; Batlle, Montserrat; Bijnens, Bart H; Mont, Lluis; Sitges, Marta; Guasch, Eduard

    2017-09-01

    Arrhythmogenic right ventricular (RV) remodeling has been reported in response to regular training, but it remains unclear how exercise intensity affects the presence and extent of such remodeling. We aimed to assess the relationship between RV remodeling and exercise load in a long-term endurance training model. Wistar rats were conditioned to run at moderate (MOD; 45 min, 30 cm/s) or intense (INT; 60 min, 60 cm/s) workloads for 16 wk; sedentary rats served as controls. Cardiac remodeling was assessed with standard echocardiographic and tissue Doppler techniques, sensor-tip pressure catheters, and pressure-volume loop analyses. After MOD training, both ventricles similarly dilated (~16%); the RV apical segment deformation, but not the basal segment deformation, was increased [apical strain rate (SR): -2.9 ± 0.5 vs. -3.3 ± 0.6 s -1 , SED vs. MOD]. INT training prompted marked RV dilatation (~26%) but did not further dilate the left ventricle (LV). A reduction in both RV segments' deformation in INT rats (apical SR: -3.3 ± 0.6 vs. -3.0 ± 0.4 s -1 and basal SR: -3.3 ± 0.7 vs. -2.7 ± 0.6 s -1 , MOD vs. INT) led to decreased global contractile function (maximal rate of rise of LV pressure: 2.53 ± 0.15 vs. 2.17 ± 0.116 mmHg/ms, MOD vs. INT). Echocardiography and hemodynamics consistently pointed to impaired RV diastolic function in INT rats. LV systolic and diastolic functions remained unchanged in all groups. In conclusion, we showed a biphasic, unbalanced RV remodeling response with increasing doses of exercise: physiological adaptation after MOD training turns adverse with INT training, involving disproportionate RV dilatation, decreased contractility, and impaired diastolic function. Our findings support the existence of an exercise load threshold beyond which cardiac remodeling becomes maladaptive. NEW & NOTEWORTHY Exercise promotes left ventricular eccentric hypertrophy with no changes in systolic or diastolic function in healthy rats. Conversely, right

  11. Creation of a novel simulator for minimally invasive neurosurgery: fusion of 3D printing and special effects.

    Science.gov (United States)

    Weinstock, Peter; Rehder, Roberta; Prabhu, Sanjay P; Forbes, Peter W; Roussin, Christopher J; Cohen, Alan R

    2017-07-01

    OBJECTIVE Recent advances in optics and miniaturization have enabled the development of a growing number of minimally invasive procedures, yet innovative training methods for the use of these techniques remain lacking. Conventional teaching models, including cadavers and physical trainers as well as virtual reality platforms, are often expensive and ineffective. Newly developed 3D printing technologies can recreate patient-specific anatomy, but the stiffness of the materials limits fidelity to real-life surgical situations. Hollywood special effects techniques can create ultrarealistic features, including lifelike tactile properties, to enhance accuracy and effectiveness of the surgical models. The authors created a highly realistic model of a pediatric patient with hydrocephalus via a unique combination of 3D printing and special effects techniques and validated the use of this model in training neurosurgery fellows and residents to perform endoscopic third ventriculostomy (ETV), an effective minimally invasive method increasingly used in treating hydrocephalus. METHODS A full-scale reproduction of the head of a 14-year-old adolescent patient with hydrocephalus, including external physical details and internal neuroanatomy, was developed via a unique collaboration of neurosurgeons, simulation engineers, and a group of special effects experts. The model contains "plug-and-play" replaceable components for repetitive practice. The appearance of the training model (face validity) and the reproducibility of the ETV training procedure (content validity) were assessed by neurosurgery fellows and residents of different experience levels based on a 14-item Likert-like questionnaire. The usefulness of the training model for evaluating the performance of the trainees at different levels of experience (construct validity) was measured by blinded observers using the Objective Structured Assessment of Technical Skills (OSATS) scale for the performance of ETV. RESULTS A

  12. Effect of surfactant on regional lung function in an experimental model of respiratory distress syndrome in rabbit.

    Science.gov (United States)

    Bayat, Sam; Porra, Liisa; Broche, Ludovic; Albu, Gergely; Malaspinas, Iliona; Doras, Camille; Strengell, Satu; Peták, Ferenc; Habre, Walid

    2015-08-01

    We assessed the changes in regional lung function following instillation of surfactant in a model of respiratory distress syndrome (RDS) induced by whole lung lavage and mechanical ventilation in eight anaesthetized, paralyzed, and mechanically ventilated New Zealand White rabbits. Regional specific ventilation (sV̇) was measured by K-edge subtraction synchrotron computed tomography during xenon washin. Lung regions were classified as poorly aerated (PA), normally aerated (NA), or hyperinflated (HI) based on regional density. A functional category was defined within each class based on sV̇ distribution (High, Normal, and Low). Airway resistance (Raw), respiratory tissue damping (G), and elastance (H) were measured by forced oscillation technique at low frequencies before and after whole lung saline lavage-induced (100 ml/kg) RDS, and 5 and 45 min after intratracheal instillation of beractant (75 mg/kg). Surfactant instillation improved Raw, G, and H (P < 0.05 each), and gas exchange and decreased atelectasis (P < 0.001). It also significantly improved lung aeration and ventilation in atelectatic lung regions. However, in regions that had remained normally aerated after lavage, it decreased regional aeration and increased sV̇ (P < 0.001) and sV̇ heterogeneity. Although surfactant treatment improved both central airway and tissue mechanics and improved regional lung function of initially poorly aerated and atelectatic lung, it deteriorated regional lung function when local aeration was normal prior to administration. Local mechanical and functional heterogeneity can potentially contribute to the worsening of RDS and gas exchange. These data underscore the need for reassessing the benefits of routine prophylactic vs. continuous positive airway pressure and early "rescue" surfactant therapy in very immature infants. Copyright © 2015 the American Physiological Society.

  13. From Interfaces to Bulk: Experimental-Computational Studies Across Time and Length Scales of Multi-Functional Ionic Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Perahia, Dvora [Clemson Univ., SC (United States); Grest, Gary S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-01-25

    Neutron experiments coupled with computational components have resulted in unprecedented understanding of the factors that impact the behavior of ionic structured polymers. Additionally, new computational tools to study macromolecules, were developed. In parallel, this DOE funding have enabled the education of the next generation of material researchers who are able to take the advantage neutron tools offer to the understanding and design of advanced materials. Our research has provided unprecedented insight into one of