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Sample records for experimental functional neurosurgery

  1. History of functional neurosurgery.

    Science.gov (United States)

    Iskandar, B J; Nashold, B S

    1995-01-01

    Whereas in the early days of evil spirits, electric catfish, and phrenology, functional neurosurgery was based on crude observations and dogma, the progress made in neurophysiology at the turn of the century gave the field a strong scientific foundation. Subsequently, the advent of stereotaxis allowed access to deep brain regions and contributed an element of precision. Future directions include the development of frameless stereotaxy; the use of MRI-generated anatomic data, which would circumvent the serious problem of individual variations seen with standard brain atlases; the introduction of various chemicals into brain structures, in an attempt to influence neurochemically mediated disease processes; and finally, the use of the promising techniques of neural transplantation. On hearing of Penfield's intraoperative brain stimulations, Sherrington commented: "It must be great fun to have the physiological preparation speak to you." The idea of therapeutic neurophysiologic interventions is appealing, especially because many disorders show no obvious treatable pathologic cause (e.g., tumor, vascular malformation). As stereotactic technology becomes less cumbersome and more precise, more sophisticated in vivo neurophysiologic preparations become possible. In turn, as our understanding of nervous system physiology grows, our ability to understand pathophysiology and treat disease processes increases.

  2. Functional neurosurgery (part 2)

    African Journals Online (AJOL)

    This month's CME includes the final two articles that review func- tional neurosurgical topics, i.e. surgery for movement disorders,[1] where deep brain stimulation plays a major role, and surgical man- agement of pain.[2] From these articles, which give an overview of the respective topics, it is clear that neurosurgery forms a ...

  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. Stereotactic imaging in functional neurosurgery

    International Nuclear Information System (INIS)

    Hirabayashi, Hidehiro

    2012-01-01

    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 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 MRI

  5. Guest Editorial: Functional neurosurgery | Enslin | South African ...

    African Journals Online (AJOL)

    South African Medical Journal. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 106, No 8 (2016) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Guest Editorial: Functional neurosurgery. JMN Enslin. Abstract. No Abstract.

  6. NEUROSURGERY

    African Journals Online (AJOL)

    our experience with management and outcomes of this condition in children treated in the Neurosurgery Unit at Inkosi. Albert Luthuli Central .... The mean duration ..... Jennet B, Bond M. Assessment of outcome after severe brain damage.

  7. Innovations in Functional Neurosurgery and Anesthetic Implications.

    Science.gov (United States)

    Dunn, Lauren K; Durieux, Marcel E; Elias, W Jeffrey; Nemergut, Edward C; Naik, Bhiken I

    2018-01-01

    Functional neurosurgery has undergone rapid growth over the last few years fueled by advances in imaging technology and novel treatment modalities. These advances have led to new surgical treatments using minimally invasive and precise techniques for conditions such as Parkinson's disease, essential tremor, epilepsy, and psychiatric disorders. Understanding the goals and technological issues of these procedures is imperative for the anesthesiologist to ensure safe management of patients presenting for functional neurosurgical procedures. In this review, we discuss the advances in neurosurgical techniques for deep brain stimulation, focused ultrasound and minimally invasive laser-based treatment of refractory epilepsy and provide a guideline for anesthesiologists caring for patients undergoing these procedures.

  8. 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

  9. 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

  10. Functional MRI for planning in neurosurgery

    International Nuclear Information System (INIS)

    Erb, M.; Saur, R.

    2007-01-01

    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.)

  11. Functional neurosurgery for movement disorders: a historical perspective.

    Science.gov (United States)

    Benabid, Alim Louis; Chabardes, Stephan; Torres, Napoleon; Piallat, Brigitte; Krack, Paul; Fraix, Valerie; Pollak, Pierre

    2009-01-01

    clear that STN stimulation is not efficient on the nondopaminergic symptoms such as freezing of gait. Based on experimental data obtained in MPTP-treated parkinsonian monkeys, the pedunculopontine nucleus has been used as a new target, and as suggested by the animal research results, its use indeed improves walking and stability when stimulation is performed at low frequency (25 Hz). The concept of simultaneous stimulation of multiple targets eventually at low or high frequency, and that of several electrodes in one target, is being accepted to increase the efficiency. This leads to and is being facilitated by the development of new hardware (multiple-channel IPGs, specific electrodes, rechargeable batteries). Still additional efforts are needed at the level of the stimulation paradigm and in the waveform. The recent development of nanotechnologies allows the design of totally new systems expanding the field of deep brain stimulation. These new techniques will make it possible to not only inhibit or excite deep brain structures to alleviate abnormal symptoms but also open the field for the use of recording cortical activities to drive neuroprostheses through brain-computer interfaces. The new field of compensation of deficits will then become part of the field of functional neurosurgery.

  12. Target localization on standard axial images in computed tomography (CT) stereotaxis for functional neurosurgery - a technical note

    International Nuclear Information System (INIS)

    Patil, A.-A.

    1986-01-01

    A simple technique for marking functional neurosurgery target on computed tomography (CT) axial image is described. This permits the use of standard axial image for computed tomography (CT) stereotaxis in functional neurosurgery. (Author)

  13. Numerical simulations of clinical focused ultrasound functional neurosurgery

    Science.gov (United States)

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-04-01

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior-posterior direction and 22 ± 14% smaller in the inferior-superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  14. Various irrigation fluids affect postoperative brain edema and cellular damage during experimental neurosurgery in rats.

    Science.gov (United States)

    Doi, Kazuhisa; Kawano, Takeshi; Morioka, Yujiro; Fujita, Yasutaka; Nishimura, Masuhiro

    2006-12-01

    This study was conducted to investigate how various irrigation fluids used during neurosurgical procedures affect the degree of postoperative brain edema and cellular damage during experimental neurosurgery in rats. The cerebral cortex was exposed and incised crosswise with a surgical knife under irrigation with an artificial CSF, lactated Ringer's solution, or normal saline. Four hours after injury, irrigation was stopped and brain tissue samples were obtained from injured and uninjured sites. Specific gravity, cerebrovascular permeability, and TTC staining of the samples were evaluated. Incision and irrigation of the brain were not performed on the control group. At the injured site, specific gravities of the samples in the normal saline group and the lactated Ringer's solution group were significantly lower than the specific gravity in the artificial CSF group. The EB concentration was significantly higher in the lactated Ringer's solution group and relatively high in the normal saline group as compared with the artificial CSF group. TTC staining did not differ significantly between the artificial CSF group and the control group. It was significantly lower in the lactated Ringer's solution group and the normal saline group than in the control group and the artificial CSF group. As compared with normal saline and lactated Ringer's solution, artificial CSF reduced postoperative brain edema, cerebrovascular permeability, and cellular damage in sites injured by experimental neurosurgery in rats.

  15. A study on CT-guided stereotactic technique for functional neurosurgery

    International Nuclear Information System (INIS)

    Uetsuhara, Koichi; Asakura, Tetsuhiko; Hirahara, Kazuho; Gondo, Masazumi; Oda, Hiroshige

    1987-01-01

    Recently, CT-guided stereotactic surgery has become of major interest, and some authors have discussed its potential in functional neurosurgery. The following is a comparative study of the CT-guided stereotactic technique and the conventional roentogenographic stereotactic technique. The Brown-Roberts-Wells apparatus was used for both types of procedures. 37 stereotactic procedures were performed on 35 patients under local anesthesia; 16 for stereotactic biopsy and 21 for stereotactic functional neurosurgery. Target points for stereotactic biopsy were determined by the CT-guided technique and target points for functional neurosurgery were determined by the conventional roentogenographic technique. The correlation with the position of target point determined by both techniques was investigated in the 21 functional neurosurgical procedures. On these occasions the authors used the reformatted horizontal and sagittal CT through the anterior and posterior commissure to determine the position of target point by the CT-guided technique. Results: It was found that the AC-PC line crossed with Reid's base line at angle of 11 ± 1 deg, and therefore it is important to obtain a CT images including AC-PC line at this angle. When applying the CT guided stereotactic procedure for functional surgery, it should be known that there could be a discrepancy within 2 mm from the conventional target determination. (author)

  16. Functional MR imaging of working memory before neurosurgery

    International Nuclear Information System (INIS)

    Wunderlich, A.P.; Groen, G.; Braun, V.

    2007-01-01

    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.)

  17. [An automatic system for anatomophysiological correlation in three planes simultaneously during functional neurosurgery].

    Science.gov (United States)

    Teijeiro, E J; Macías, R J; Morales, J M; Guerra, E; López, G; Alvarez, L M; Fernández, F; Maragoto, C; Seijo, F; Alvarez, E

    The Neurosurgical Deep Recording System (NDRS) using a personal computer takes the place of complex electronic equipment for recording and processing deep cerebral electrical activity, as a guide in stereotaxic functional neurosurgery. It also permits increased possibilities of presenting information in direct graphic form with automatic management and sufficient flexibility to implement different analyses. This paper describes the possibilities of automatic simultaneous graphic representation in three almost orthogonal planes, available with the new 5.1 version of NDRS so as to facilitate the analysis of anatomophysiological correlation in the localization of deep structures of the brain during minimal access surgery. This new version can automatically show the spatial behaviour of signals registered throughout the path of the electrode inside the brain, superimposed simultaneously on sagittal, coronal and axial sections of an anatomical atlas of the brain, after adjusting the scale automatically according to the dimensions of the brain of each individual patient. This may also be shown in a tridimensional representation of the different planes themselves intercepting. The NDRS system has been successfully used in Spain and Cuba in over 300 functional neurosurgery operations. The new version further facilitates analysis of spatial anatomophysiological correlation for the localization of brain structures. This system has contributed to increase the precision and safety in selecting surgical targets in the control of Parkinson s disease and other disorders of movement.

  18. From Structure to Circuits: The Contribution of MEG Connectivity Studies to Functional Neurosurgery.

    Science.gov (United States)

    Pang, Elizabeth W; Snead Iii, O C

    2016-01-01

    New advances in structural neuroimaging have revealed the intricate and extensive connections within the brain, data which have informed a number of ambitious projects such as the mapping of the human connectome. Elucidation of the structural connections of the brain, at both the macro and micro levels, promises new perspectives on brain structure and function that could translate into improved outcomes in functional neurosurgery. The understanding of neuronal structural connectivity afforded by these data now offers a vista on the brain, in both healthy and diseased states, that could not be seen with traditional neuroimaging. Concurrent with these developments in structural imaging, a complementary modality called magnetoencephalography (MEG) has been garnering great attention because it too holds promise for being able to shed light on the intricacies of functional brain connectivity. MEG is based upon the elemental principle of physics that an electrical current generates a magnetic field. Hence, MEG uses highly sensitive biomagnetometers to measure extracranial magnetic fields produced by intracellular neuronal currents. Put simply then, MEG is a measure of neurophysiological activity, which captures the magnetic fields generated by synchronized intraneuronal electrical activity. As such, MEG recordings offer exquisite resolution in the time and oscillatory domain and, as well, when co-registered with magnetic resonance imaging (MRI), offer excellent resolution in the spatial domain. Recent advances in MEG computational and graph theoretical methods have led to studies of connectivity in the time-frequency domain. As such, MEG can elucidate a neurophysiological-based functional circuitry that may enhance what is seen with MRI connectivity studies. In particular, MEG may offer additional insight not possible by MRI when used to study complex eloquent function, where the precise timing and coordination of brain areas is critical. This article will review the

  19. 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 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 patients' discomfort during DBS

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

    International Nuclear Information System (INIS)

    Nishimura, Hiroyuki; Hirai, Tatsuo.

    1993-01-01

    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 and 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. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Hiroyuki [Kochi Medical School, Nankoku (Japan); Hirai, Tatsuo

    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 and 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. (author).

  2. [In the 100 birth anniversary of the pioneer of stereotactic brain surgery in Poland professor Oskar Liszka. Functional neurosurgery in Poland and in Krakow].

    Science.gov (United States)

    Stachura, Krzysztof

    2016-01-01

    This article is the report from the meeting of the Medical Society of Cracow, that has been devoted to the 100 birth anniversary of Oskar Liszka, Assoc. Prof., MD. In the course of the meeting Professor Oskar Liszka's figure has been reminded and his work as a pioneer of stereotactic surgery in Poland has been discussed. In the next two sections, the development of functional neurosurgery in Poland and achievements in this field in the Department of Neurosurgery and Neurotraumatology of Jagiellonian University Collegium Medicum in Krakow have been presented.

  3. [History of world neurosurgery].

    Science.gov (United States)

    Wang, X

    2017-05-28

    In 5000 BC, South American tribes digged the bones in the living head to seek ways to communicate with the gods, which was primitive trephination and may be the first neurosurgical behavior. In 2600 BC, Imhotep in ancient Egypt took the brain out of the head from the nose, for a better preserve of the mummy, which was a prototype of modern transsphenoidal surgery. And the development of anatomy in ancient Greek laid a solid foundation for neurosurgery. From 500 to 1500 AD, the rise of religion and the occurrence of war, prompted a large number of craniocerebral trauma, which contributed greatly to the early development of neurosurgery as a distinct specialty. In 1861, Brocca astutely localized the language function to the third left frontal convolution in a series of studies, which was considered to be of landmark importance in the understanding of cerebral localization. In 1878, William Macewen performed a successful surgery to remove an en plaque meningioma with intrathecal anesthesia, representing the first modern neurosurgical operation. However, the contributions of the Americans, starting with Harvey Cushing, exerted a definitive force. Portuguese Moritz performed the first cerebral angiogram on a living schizophrenia patient in 1926. And he established the Moniz-Lima prefrontal leucotomy for the treatment of schizophrenia, for which he won the Nobel Prize in Physiology and Medicine in 1949. In 1968, the Swiss scholar Yassagir firstly carried out neurosurgical surgeries under the microscope. China's neurosurgery was founded by Zhao Yicheng in 1952 in Tianjin, and the gap in neurosurgery between China and the world gradually narrowed after 60 years of development.

  4. 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.)

  5. [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.

  6. Application of language blood oxygenation level dependent functional MRI in the navigating operation of neurosurgery

    International Nuclear Information System (INIS)

    Liu Shuyong; Li Min; Yao Chengjun; Geng Daoying

    2011-01-01

    Objective: To verify the accuracy of blood oxygenation level dependent (BOLD)-based activation using electrocortical stimulation mapping (ESM) and explore the value of language fMRI in the navigating operation of neurosurgery. Methods: In 8 cases with brain tumors, BOLD-fMRI examinations were done before the operations. Under the state of awake anesthesia,the patients were aroused and ESM was conducted. Point-to-point comparison between the BOLD signal activations and the ESM was carried out under the surveillance of the neuro-navigation technology. In order to observe the sensibility and specificity of BOLD activations, the location of BOLD activations and the point of ESM was compared to calculate the stimulating positive points inside the regions of BOLD signals (real positive), outside BOLD regions (pseudo- negative), the stimulating negative points inside the regions of BOLD signals (pseudo-positive), and outside BOLD region (real negative). Two kinds of criteria for assessment were used. One was that the positive stimulating points were located in BOLD regions, and the other was that the positive stimulating points were located within 1 cm around the range of BOLD regions. Removal of the lesions were conducted with the tissue 1 cm around the language region preserved, and the cortex inside 0.5-1.0 cm distance from the positive points were retained. Results: Of the 8 cases, only 6 finished the tasks. Among them, 3 cases were with astrocytoma of grade 2, 2 were with astrocytoma of grade 3, and one with glioblastoma. The total number of stimulating points was 48, among which the positive points were 11. When the first criteria was applied, the sensitivity was 72.7% (8/11), and the specificity was 81.8% (30/37). When the second criteria was applied, the sensitivity was 82.0% (9/11), and the specificity was 75.6% (28/37). Follow-up after operation showed no aphasia occurred. Conclusions: BOLD-fMRI had a high sensitivity and specificity in displaying the language

  7. 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

  8. Tethered spinal cord: the effect of neurosurgery on the lower urinary tract and male sexual function

    NARCIS (Netherlands)

    Boemers, T. M.; van Gool, J. D.; de Jong, T. P.

    1995-01-01

    To determine the effect of neurosurgical untethering on the lower urinary tract and male sexual function, in patients with tethered spinal cord. Thirty-six children with tethered spinal cord due to neurospinal dysraphism were assessed clinically and urodynamically before and after surgical

  9. Determination of language lateralization using functional MRI during the performance of shiritori tasks in neurosurgery patients

    International Nuclear Information System (INIS)

    Takayama, Hideichi; Kobayashi, Masahito; Sugishita, Morihiro; Onozuka, Satoshi; Kawase, Takeshi

    2001-01-01

    Assessment of language lateralization is crucial in patients considered for neurological surgery. The authors used functional MRI (fMRI) in conjunction with shiritori, a kind of word-generation task as paradigms, to determine language lateralization in the patients. We used a 1.5 Tesla magnetic resonance imaging devise with an echo-planar imaging sequence. Thirty-two patients undergoing neurological surgery would alternately rest and silently perform shiritori during fMRI acquisition. Language lateralization was determined in 29 out of 32 patients. Twenty-two patients were considered as left-hemisphere dominant and seven were right-hemisphere dominant. Brain activation was seen in the prefrontal area, premotor area, superior temporal gyrus and parietal lobe of the dominant hemisphere, which is consistent with the results in normal adults. Language lateralization was particularly useful in a case of meningioma in the left lateral ventricle and in a case of AVM in the left temporoparietal region. fMRI with shiritori tasks revealed right-hemisphere dominance in both cases, which was also confirmed by intracarotid amobarbital (Wada) testing. Both lesions were treated successfully without causing any further deficit to the patients' language function. These results suggest that fMRI with shiritori tasks can be used to assess language lateralization non-invasively, compared with the current techniques, such as intracarotid amobarbital testing and cortical electrostimulation mapping. Thus, fMRI with shiritori tasks has significant clinical potential as a presurgical evaluation tool. (author)

  10. Determination of language lateralization using functional MRI during the performance of shiritori tasks in neurosurgery patients

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Hideichi; Kobayashi, Masahito [Mihara Memorial Hospital, Isesaki, Gunma (Japan); Sugishita, Morihiro; Onozuka, Satoshi; Kawase, Takeshi

    2001-03-01

    Assessment of language lateralization is crucial in patients considered for neurological surgery. The authors used functional MRI (fMRI) in conjunction with shiritori, a kind of word-generation task as paradigms, to determine language lateralization in the patients. We used a 1.5 Tesla magnetic resonance imaging devise with an echo-planar imaging sequence. Thirty-two patients undergoing neurological surgery would alternately rest and silently perform shiritori during fMRI acquisition. Language lateralization was determined in 29 out of 32 patients. Twenty-two patients were considered as left-hemisphere dominant and seven were right-hemisphere dominant. Brain activation was seen in the prefrontal area, premotor area, superior temporal gyrus and parietal lobe of the dominant hemisphere, which is consistent with the results in normal adults. Language lateralization was particularly useful in a case of meningioma in the left lateral ventricle and in a case of AVM in the left temporoparietal region. fMRI with shiritori tasks revealed right-hemisphere dominance in both cases, which was also confirmed by intracarotid amobarbital (Wada) testing. Both lesions were treated successfully without causing any further deficit to the patients' language function. These results suggest that fMRI with shiritori tasks can be used to assess language lateralization non-invasively, compared with the current techniques, such as intracarotid amobarbital testing and cortical electrostimulation mapping. Thus, fMRI with shiritori tasks has significant clinical potential as a presurgical evaluation tool. (author)

  11. 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.

  12. Neurosurgery. Fourth edition

    International Nuclear Information System (INIS)

    Simon, L.; Thomas, D.G.T.; Clark, W.K.

    1987-01-01

    The Fourth Edition of this volume in the Operative Surgery Series has been considerably revised to accommodate the many changes which have changed the practice of neurosurgery in the past eight years. There have been advances in technology, such as the wider application of CT scanning, in surgical technique, and in the design of new implantable materials. All these developments have substantially affected both the practice of neurosurgery and the prognosis for the patient and are fully reflected in the new edition

  13. Challenges in paediatric neurosurgery

    Directory of Open Access Journals (Sweden)

    Pragati Ganjoo

    2017-01-01

    Full Text Available Improvements in technique, knowledge and expertise have brought about rapid advances in the fields of paediatric neurosurgery and anaesthesia, and many procedures limited earlier to adults are now being increasingly attempted in neonates and small children, with good outcomes. This article highlights the challenges faced by the operating team while handling some of the technically complex procedures like awake craniotomy, interventional neuroradiology, minimally invasive neurosurgery, procedures in intraoperative magnetic resonance imaging suites, and neonatal emergencies in the paediatric population.

  14. New CT-aided stereotactic neurosurgery technique

    International Nuclear Information System (INIS)

    Shao, H.M.; Truong, T.K.; Reed, I.S.; Slater, R.A.

    1985-01-01

    In this communication, a new technique for CT-aided stereotactic neurosurgery is presented. The combination of specially designed hardware and software provides a fast, simple, and versatile tool for the accurate insertion of a probe into the human brain. This system is portable and can be implemented on any CT computer system. The complete procedure to perform the CT-aided stereotactic neurosurgery technique is presented. Experimental results are given which demonstrate the power of the method. Finally, the key algorithms for realizing this technique are described in the Appendix

  15. Endovascular Neurosurgery: Personal Experience and Future Perspectives.

    Science.gov (United States)

    Raymond, Jean

    2016-09-01

    From Luessenhop's early clinical experience until the present day, experimental methods have been introduced to make progress in endovascular neurosurgery. A personal historical narrative, spanning the 1980s to 2010s, with a review of past opportunities, current problems, and future perspectives. Although the technology has significantly improved, our clinical culture remains a barrier to methodologically sound and safe innovative care and progress. We must learn how to safely practice endovascular neurosurgery in the presence of uncertainty and verify patient outcomes in real time. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Augmented reality in neurosurgery.

    Science.gov (United States)

    Tagaytayan, Raniel; Kelemen, Arpad; Sik-Lanyi, Cecilia

    2018-04-01

    Neurosurgery is a medical specialty that relies heavily on imaging. The use of computed tomography and magnetic resonance images during preoperative planning and intraoperative surgical navigation is vital to the success of the surgery and positive patient outcome. Augmented reality application in neurosurgery has the potential to revolutionize and change the way neurosurgeons plan and perform surgical procedures in the future. Augmented reality technology is currently commercially available for neurosurgery for simulation and training. However, the use of augmented reality in the clinical setting is still in its infancy. Researchers are now testing augmented reality system prototypes to determine and address the barriers and limitations of the technology before it can be widely accepted and used in the clinical setting.

  17. Interstitial laser thermotherapy in neurosurgery: a review

    NARCIS (Netherlands)

    Menovsky, T.; Beek, J. F.; van Gemert, M. J.; Roux, F. X.; Bown, S. G.

    1996-01-01

    One of the most recent laser treatment modalities in neurosurgery is interstitial laser thermotherapy (ILTT). In this review, experimental and clinical studies concerning intracranial ILTT are discussed. Two methods for intra-operative control of the laser induced lesions are described; i.e.,

  18. Samii's essentials in neurosurgery

    International Nuclear Information System (INIS)

    Ramina, Ricardo; Pontifical Catholic Univ. of Parana, Curitiba; Pires Aguiar, Paulo Henrique; Sao Paulo Univ.; Hospital Santa Paula, Sao Paulo; Tatagiba, Marcos

    2008-01-01

    'Samii's Essentials in Neurosurgery' contains selected papers written by internationally recognized contributors who were trained by Professor Madjid Samii in Hannover, Germany. The main topics deal with cutting-edge technology in neurosurgery, skull-base surgery, and specific peripheral nerve, spine, and vascular surgeries. The texts and a wealth of illustrations review and reinforce guidelines on the diagnosis and management of situations that readers are likely to encounter in everyday practice. This book will be of great interest to neurosurgeons, neurologists, ENT surgeons, neuroradiologists, and neurophysiotherapists. (orig.)

  19. Chronic Pain in Neurosurgery.

    Science.gov (United States)

    Grodofsky, Samuel

    2016-09-01

    This review includes a summary of contemporary theories of pain processing and advocates a multimodal analgesia approach for providing perioperative care. A summary of various medication classes and anesthetic techniques is provided that highlights evidence emerging from neurosurgical literature. This summary covers opioid management, acetaminophen, nonsteroidal antiinflammatories, ketamine, lidocaine, dexmedetomidine, corticosteroids, gabapentin, and regional anesthesia for neurosurgery. At present, there is not enough investigation into these areas to describe best practices for treating or preventing chronic pain in neurosurgery; but providers can identify a wider range of options available to personalize perioperative care strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Intraoperative ultrasound in neurosurgery

    International Nuclear Information System (INIS)

    Velasco, J.; Manzanares, R.; Fernandez, L.; Hernando, A.; Ramos, M. del Mar; Garcia, R.

    1996-01-01

    The present work is a review of the major indications for intraoperative ultrasound in the field of neurosurgery, stressing the exploratory method and describing what we consider to be the most illustrative cases. We attempt to provide a thorough view of this constantly developing technique which, despite its great practical usefulness, may be being underemployed. (Author) 47 refs

  1. Advanced technology in neurosurgery

    International Nuclear Information System (INIS)

    Pluchino, F.; Broggi, G.

    1987-01-01

    Technological improvements in neurosurgery are discussed. The use of surgical lasers, ultrasound aspirators, bipolar coagulator and operative microscopes for surgery of deep-seated neoplasms and vascular malformations is discussed. Intraoperative monitoring, chronotherapy, chronic neurostimulation and stereotactic interstitial irradiation are covered and indications for interventional neuroradiology are reviewed

  2. Stereotactic neurosurgery for tremor

    NARCIS (Netherlands)

    Speelman, Johannes D.; Schuurman, Richard; de Bie, Rob M. A.; Esselink, Rianne A. J.; Bosch, D. Andries

    2002-01-01

    The role of the motor thalamus as surgical target in stereotactic neurosurgery for different kinds of tremor is discussed. For tremor in Parkinson's disease. the subthalamic nucleus becomes more and more often the surgical target, because this target also gives relief of other and more

  3. Simulating tumour removal in neurosurgery.

    Science.gov (United States)

    Radetzky, A; Rudolph, M

    2001-12-01

    In this article the software system ROBO-SIM is described. ROBO-SIM is a planning and simulation tool for minimally invasive neurosurgery. Different to the most other simulation tools, ROBO-SIM is able to use actual patient's datasets for simulation. Same as in real neurosurgery a planning step, which provides more functionality as up-to-date planning systems on the market, is performed before undergoing the simulated operation. The planning steps include the definition of the trepanation point for entry into the skull and the target point within the depth of the brain, checking the surgical track and doing virtual trepanations (virtual craniotomy). For use with an intra-operative active manipulator, which is guided by the surgeon during real surgery (robotic surgery), go- and non-go-areas can be defined. During operation, the robot restricts the surgeon from leaving these go-areas. After planning, an additional simulation system, which is understood as an extension to the planning step, is used to simulate whole surgical interventions directly on the patient's anatomy basing on the planning data and by using the same instruments as for the real intervention. First tests with ROBO-SIM are performed on a phantom developed for this purpose and on actual patient's datasets with ventricular tumours.

  4. NASA Robotic Neurosurgery Testbed

    Science.gov (United States)

    Mah, Robert

    1997-01-01

    The detection of tissue interface (e.g., normal tissue, cancer, tumor) has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations, In neurosurgery, the needle used in the standard stereotactic CT or MRI guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. In addition, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle tearing a blood vessel within the brain is the most devastating complication of stereotactic CT/MRI guided brain biopsy. A robotic neurosurgery testbed has been developed at NASA Ames Research Center as a spin-off of technologies from space, aeronautics and medical programs. The invention entitled "Robotic Neurosurgery Leading to Multimodality Devices for Tissue Identification" is nearing a state ready for commercialization. The devices will: 1) improve diagnostic accuracy and precision of general surgery, with near term emphasis on stereotactic brain biopsy, 2) automate tissue identification, with near term emphasis on stereotactic brain biopsy, to permit remote control of the procedure, and 3) reduce morbidity for stereotactic brain biopsy. The commercial impact from this work is the potential development of a whole new generation of smart surgical tools to increase the safety, accuracy and efficiency of surgical procedures. Other potential markets include smart surgical tools for tumor ablation in neurosurgery, general exploratory surgery, prostate cancer surgery, and breast cancer surgery.

  5. 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.

  6. [Virtual reality in neurosurgery].

    Science.gov (United States)

    Tronnier, V M; Staubert, A; Bonsanto, M M; Wirtz, C R; Kunze, S

    2000-03-01

    Virtual reality enables users to immerse themselves in a virtual three-dimensional world and to interact in this world. The simulation is different from the kind in computer games, in which the viewer is active but acts in a nonrealistic world, or on the TV screen, where we are passively driven in an active world. In virtual reality elements look realistic, they change their characteristics and have almost real-world unpredictability. Virtual reality is not only implemented in gambling dens and the entertainment industry but also in manufacturing processes (cars, furniture etc.), military applications and medicine. Especially the last two areas are strongly correlated, because telemedicine or telesurgery was originated for military reasons to operate on war victims from a secure distance or to perform surgery on astronauts in an orbiting space station. In medicine and especially neurosurgery virtual-reality methods are used for education, surgical planning and simulation on a virtual patient.

  7. 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.)

  8. NeuroSPECT demonstrates increased cortical function in Alzheimer's disease patients for at least two years after omental transposition neurosurgery

    International Nuclear Information System (INIS)

    Shankle, William R; Mena, Ismael; Hara, Junko; O'Heany, Terence; Bjornsen, Lynda; Gade, George; Leport, Peter; Ali, Mir; Rayhaun, Abraham; Kim, Jinho; Malkazian, Dennis; Raimo, Maryellen; Reyes, Linda; Fallon, James; Kim, Ronald

    2006-01-01

    Clinical improvement following surgical transposition of the omentum to the brain (OTS) has been observed in a variety of neurologic disorders, including stroke, encephalitis, cerebral palsy, spinal cord transaction and Alzheimer's disease. The basis for such improvement is not known, but may relate to the presence of stem cells and growth factors in the omentum, which have been implicated in angiogenesis, neurogenesis and neuronal survival. The present report describes the changes in brain activity in two patients with biopsy confirmed Alzheimer's disease (AD) whose course had entered a phase of more rapid decline prior to OTS. The patients were followed with disease severity (Clinical Dementia Rating Scale), cognitive (Mini-Mental Status Exam) and HMPAO NeuroSPECT measures for 22 and 42 months. Dementia severity lessened for 2 or more years while cortical activity in areas underneath, adjacent to, and contralateral to the omentum increased by 1-2 standard deviations above the patient's preoperative baseline (maximum increase was 21%, 4 Standard Deviations). In the more mildly demented AD patient 22 months after OTS, the posterior cingulate cortex showed up to a 20% increase in activity compared to is preoperative level of activity. This is remarkable in that the omentum had no direct contact with the posterior cingulate gyrus, which is involved in the early stages of AD neuropathology (Braak and Braak stages 3-4). These findings warrant further investigation into the mechanism(s) by which the omentum can improve cortical activity and clinical function for two or more years in Alzheimers' disease (au)

  9. Application of fiber tractography for neurosurgery

    International Nuclear Information System (INIS)

    Hashimoto, Naoya; Yoshimine, Toshiki

    2007-01-01

    This review describes about the fiber tractography (FT) for its basic principle, method, and application to neurosurgery involving usefulness, pitfall, validation needed and future perspective. MR diffusion weighted image exhibits the diffusion (Brownian movement) of water molecules and its multiple images taken by different angles of magnetic field can also give information of their diffusion anisotropy, whereby diffusion tensor image is yielded as FT owing to their high anisotropy, with use of appropriate softwares assuming an ellipsoid of anisotropic water (single tensor model). FT thus presents an image of a specific and functional neurofiber bundle. Recently, FT in neurosurgery has been recognized to have pitfalls in tracing the bundle at its crossing and branch, e.g., suggested avoidance of surgery of eloquent area navigated with FT alone. For this, developed and considered are the multi-tensor models based on multiple ellipsoids and on probabilistic one on probability, and combination of electrophysiological mapping is thought necessary as well. Application of FT is also actively in progress to understand neurological diseases like cerebral vascular lesion, hemiplegia, epilepsy, injury and many others. FT navigation without other validation is thus limited in neurosurgery, but FT is surely one of means to improve patients' prognosis and quality of life (QOL). (R.T.)

  10. Mythology and Neurosurgery.

    Science.gov (United States)

    Ökten, Ali İhsan

    2016-06-01

    Myths are the keystone of mythology. They are interpretations of events that have been told as stories and legends for thousands of years, inherited from generation to generation, and have reached the present day. Although most myths are considered figments of the imagination or fictitious legends, all of them contain references to facts from the time they occurred. Mythology, which is a collection of figments of imagination concerning nature and human beings, is a product of human effort to perceive, explain, and interpret the universe and the world, much like science. The interaction between mythology and science dates back to the early days of civilization. Mythology, a reflection of human creativity, is extensively used in modern science, particularly in a terminological context. This article aims to reveal the texture of mythology in neurosurgery, by analyzing the birth of medicine in mythology; heroes such as Apollo and Asklepios, the gods of healing and medicine, as well as Hygieia, the goddess of health and hygiene; and mythological terms and phrases such as Achilles tendon, atlas vertebra, gigantism, priapism syndrome, hippocampus, lethargy, syrinx, and arachnoid. Through the use of symbols, mythology has attempted to explain several subjects, such as human nature, disease, birth, and death. In this respect, mythology and medicine dance arm in arm, and this dance has been going on for centuries. As a result, mythology has manifested itself in many fields within medicine, either anatomically or by giving names to various diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. [African neurosurgery. 1: Historical outline].

    Science.gov (United States)

    el Khamlichi, A

    1996-01-01

    This outline of the history of African Neurosurgery explains the role that North Africa has played in the Middle Ages in the development of Neurosurgery, the origins of the development of the latter in twentieth century, and the delay that African Neurosurgery still shows at the present time in the majority of African countries. On the papyrus of the pharaonic era, we have found the description of some neurosurgical procedures such as trephination and brain aspiration by a transphenoidal approach used before mummification. It is particularly trephination which summarizes the ancient history of African neurosurgery, as it was widely used throughout the continent, practised and taught by healers in African tribes. The technical concepts of trephination are based, to a great extent, on the descriptions of Arab physicians of the Middle Ages. It was at that time (Middle Ages) that several Arab physicians such as Avicenne, Rhazes, and Avenzhoer described many types of nervous system diseases and the techniques to treat them. But it was mainly Abulkassim Al Zahraoui (Abulkassis) who was the pioneer of neurosurgery as he devoted one volume of his treatise (made up of 30 volumes) to neurosurgery, a precise description of many aspects of neurosurgical pathology, its treatment, instruments and neurosurgical techniques. We have reported in this article five original extracts in Arabic which deal with skull fractures and their treatment, vertebro-medullary traumas and their treatment, hydrocephalus and its treatment, tumors of the skull vault and their treatment, and finally the basic knowledge of anatomy which is of great interest for a surgeon. The medical knowledge of that time which gave birth to medical schools and hospitals was transmitted progressively to Europe and played an important role in the development of medicine during the European Renaissance in the fifteenth and sixteenth centuries. During colonization, neurosurgical practice started and developed in many

  12. 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.

  13. History of Neurosurgery in Malaysia.

    Science.gov (United States)

    Raffiq, Azman; Abdullah, Jafri Malin; Haspani, Saffari; Adnan, Johari Siregar

    2015-12-01

    The development of neurosurgical services and training in Malaysia began in 1963, with the first centre established in its capital city at Hospital Kuala Lumpur, aimed to provide much needed neurosurgical services and training in the field of neurology and neurosurgery. This center subsequently expanded in 1975 with the establishment of the Tunku Abdul Rahman Neuroscience Institute (IKTAR); which integrated the three allied interdependent disciplines of neurosurgery, neurology and psychiatry. The establishment of this institute catalysed the rapid expansion of neurosurgical services in Malaysia and paved the way for development of comprehensive training for doctors, nurses, and paramedics. This culminated in the establishments of a local comprehensive neurosurgery training program for doctors in 2001; followed by a training program for nurses and paramedics in 2006. To date, there are more than 60 neurosurgeons providing expert care in 11 centers across Malaysia, along with trained personnel in the field of neurosciences.

  14. Progress of women in neurosurgery.

    Science.gov (United States)

    Spetzler, Robert F

    2011-01-01

    Despite advances in issues related to gender equity, barriers to recruiting and retaining women in neurosurgery continue to exist. At the same time, the overall projected shortage of neurosurgeons suggests that women will be vital to the long-term success of the field. Attracting women to neurosurgery can capitalize on strategies, such as mentoring, teaching leadership and negotiating skills, and job sharing or dual training tracks to name a few, that would benefit both men and women passionate about pursuing neurosurgery. Ultimately, personal and institutional accountability must be evaluated to ensure that the best and brightest candidates, regardless of gender, are recruited to neurosurgical programs to promote the health of our challenging but most satisfying profession.

  15. 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)

  16. 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.

  17. 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.

  18. Functional Neurosurgery in the Treatment of Severe Obsessive Compulsive Disorder and Major Depression: Overview of Disease Circuits and Therapeutic Targeting for the Clinician

    Science.gov (United States)

    Shah, Dhwani B.; Pesiridou, Angeliki; Baltuch, Gordon H.; Malone, Donald A.; O’Reardon, John P.

    2008-01-01

    Over the past 20 years, there has been a concerted effort to expand our understanding of the neural circuitry involved in the pathogenesis of psychiatric disorders. Distinct neuronal circuits and networks have been implicated in obsessive compulsive disorder (OCD) and major depressive disorder (MDD) involving feedback loops between the cortex, striatum, and thalamus. When neurosurgery is used as a therapeutic tool in severe OCD and MDD, the goal is to modulate specific targets or nodes within these networks in an effort to produce symptom relief. Currently, four lesioning neurosurgical procedures are utilized for treatment refractory OCD and MDD: cingulotomy, capsulotomy, subcaudate tractotomy, and limbic leucotomy. Deep brain stimulation (DBS) is a novel neurosurgical approach that has some distinct advantages over lesioning procedures. With DBS, the desired clinical effect can be achieved by reversible, high frequency stimulation in a nucleus or at a node in the circuit without the need to produce an irreversible lesion. Recent trials of deep brain stimulation in both OCD and MDD at several neuroanatomical targets have reported promising early results in highly refractory patients and with a good safety profile. Future definitive trials in MDD and OCD are envisaged. PMID:19727257

  19. 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.

  20. Highly cited works in neurosurgery. Part II: the citation classics.

    Science.gov (United States)

    Ponce, Francisco A; Lozano, Andres M

    2010-02-01

    The term "citation classic" has been used in reference to an article that has been cited more than 400 times. The purpose of this study is to identify such articles that pertain to clinical neurosurgery. A list of search phrases relating to neurosurgery was compiled. A topic search was performed using the Institute for Scientific Information Web of Science for phrases. Articles with more than 400 citations were identified, and nonclinical articles were omitted. The journals, year of publication, topics, and study types were analyzed. There were 106 articles with more than 400 citations relating to clinical neurosurgery. These articles appeared in 28 different journals, with more than half appearing in the Journal of Neurosurgery or the New England Journal of Medicine. Fifty-three articles were published since 1990. There were 38 articles on cerebrovascular disease, 21 on stereotactic and functional neurosurgery, 21 on neurooncology, 19 on trauma, 4 on nontraumatic spine, 2 on CSF pathologies, and 1 on infection. There were 29 randomized trials, of which 86% appeared in the New England Journal of Medicine, Lancet, or the Journal of the American Medical Association, and half concerned the prevention or treatment of stroke. In addition, there were 16 prospective studies, 15 classification or grading systems, and 7 reviews. The remaining 39 articles were case series, case reports, or technical notes. More than half of the citation classics identified in this study have been published in the past 20 years. Case series, classifications, and reviews appeared more frequently in neurosurgical journals, while randomized controlled trials tended to be published in general medical journals.

  1. Operative Landscape at Canadian Neurosurgery Residency Programs.

    Science.gov (United States)

    Tso, Michael K; Dakson, Ayoub; Ahmed, Syed Uzair; Bigder, Mark; Elliott, Cameron; Guha, Daipayan; Iorio-Morin, Christian; Kameda-Smith, Michelle; Lavergne, Pascal; Makarenko, Serge; Taccone, Michael S; Wang, Bill; Winkler-Schwartz, Alexander; Sankar, Tejas; Christie, Sean D

    2017-07-01

    Background Currently, the literature lacks reliable data regarding operative case volumes at Canadian neurosurgery residency programs. Our objective was to provide a snapshot of the operative landscape in Canadian neurosurgical training using the trainee-led Canadian Neurosurgery Research Collaborative. Anonymized administrative operative data were gathered from each neurosurgery residency program from January 1, 2014, to December 31, 2014. Procedures were broadly classified into cranial, spine, peripheral nerve, and miscellaneous procedures. A number of prespecified subspecialty procedures were recorded. We defined the resident case index as the ratio of the total number of operations to the total number of neurosurgery residents in that program. Resident number included both Canadian medical and international medical graduates, and included residents on the neurosurgery service, off-service, or on leave for research or other personal reasons. Overall, there was an average of 1845 operative cases per neurosurgery residency program. The mean numbers of cranial, spine, peripheral nerve, and miscellaneous procedures were 725, 466, 48, and 193, respectively. The nationwide mean resident case indices for cranial, spine, peripheral nerve, and total procedures were 90, 58, 5, and 196, respectively. There was some variation in the resident case indices for specific subspecialty procedures, with some training programs not performing carotid endarterectomy or endoscopic transsphenoidal procedures. This study presents the breadth of neurosurgical training within Canadian neurosurgery residency programs. These results may help inform the implementation of neurosurgery training as the Royal College of Physicians and Surgeons residency training transitions to a competence-by-design curriculum.

  2. Frameless neuronavigation in modern neurosurgery.

    Science.gov (United States)

    Spetzger, U; Laborde, G; Gilsbach, J M

    1995-12-01

    A fundamental effort in neurosurgery is to reduce surgical trauma. Microneurosurgical technique combined with precise localization of lesions, can minimize the invasiveness of neurosurgical procedures. This report summarizes the utility of frameless neuronavigator systems and examines their value in reducing operative invasiveness. The basic principle of neuronavigation is the virtual linkage between digitized neuroradiological data and real anatomical structures, allowing an excellent three-dimensional orientation by real-time graphic-anatomic interaction. As frameless graphic interactive neuronavigation is developed further, these devices should become an important component of the modern microneurosurgical armamentarium and reduce surgical morbidity.

  3. Challenges in contemporary academic neurosurgery.

    Science.gov (United States)

    Black, Peter M

    2006-03-01

    Traditionally, the ideal academic neurosurgeon has been a "quadruple threat," with excellence in clinical work, teaching, research, and administration. This tradition was best exemplified in Harvey Cushing, who developed the field of neurosurgery 90 years ago. This paradigm will probably have to change as academic neurosurgeons face major challenges. In patient care, these include increasing regulatory control, increasing malpractice costs, consolidation of expensive care in academic centers, and decreasing reimbursement; in resident teaching, work hour limitations and a changing resident culture; in research, the increasing dominance of basic scientists in governmental funding decisions and decreased involvement of neurosurgeons in scientific review committees; and in administration, problems of relationships in the workplace, patient safety, and employment compliance in an increasingly bureaucratic system. To meet these challenges, the new academic neurosurgeon will probably not be a quadruple threat personally but will be part of a quadruple threat in a department and institution. Neurosurgeons in such a setting will have to work with hospital, medical school, and national and international groups to address malpractice, reimbursement, subspecialization, and training problems; find supplemental sources of income through grants, development funds, and hospital support; lead in the development of multidisciplinary centers for neuroscience, brain tumor, spine, and other initiatives; and focus on training leaders for hospital, regional, and national groups to reconfigure neurosurgery. Collaboration, flexibility, and leadership will be characteristic of the academic neurosurgeon in this new era.

  4. Department of Neurosurgery, Madurai Medical College and the development of neurosurgery in South Tamil Nadu.

    Science.gov (United States)

    Thiruppathy, Subbiah; Manimaran, Ramiah; Niban, Gopalakrishnan M; Muthukumar, Natarajan

    2018-01-01

    The development of neurosurgery in South Tamil Nadu can be traced to the Department of Neurosurgery, Madurai Medical College and Government Rajaji Hospital, Madurai, Tamil Nadu, India. The hospital was established in the year 1940 and Madurai Medical College was started in 1954. Prof. M. Natarajan founded this department in September, 1963. This department has a Neurosurgery Residency Program that is 50 years old. The establishment of this department and its growth to its present stature is documented here.

  5. The history of neurosurgery in Bolivia and pediatric neurosurgery in Santa Cruz de la Sierra

    OpenAIRE

    Dabdoub, Carlos F.; Dabdoub, Carlos B.

    2013-01-01

    The practice of neurosurgery in Bolivia began thousands of years ago with skull trepanation. This procedure dates from the earliest period of the Tiwanaku culture, a preInca civilization. Neurosurgical development in Bolivia has its origins in the late 19th century and can be divided in two stages. At the beginning, before the advent of neurosurgery as a discipline, some general surgeons performed procedures on the skull and brain. Formal neurosurgery in Bolivia was developed with the arrival...

  6. [Changing the teaching of neurosurgery with information technology].

    Science.gov (United States)

    Moreau, Jean-Jacques; Caire, François; Kalamarides, Michel; Mireau, Etienne; Dauger, Frédéric; Coignac, Marie-Jo; Charlin, Bernard

    2009-10-01

    A digital campus is a distance learning site that uses the potential of information and communication technologies to disseminate and improve educational services. This website, with open and free access, is built from free software with Web 2.0 technology. It is hosted at the University of Limoges. It functions as a digital library, containing scanned books, slide shows, more than 200 hours of recorded courses and round tables accessible by streaming video. The site is indexed according to the users' needs, by level of knowledge, specialty, keywords, and supplementary MeSH terms. The campus is organized as the College of Neurosurgery (http://college.neurochirurgie.fr). The durability of this type of training (in existence for 9 years now) is made possible by a powerful and committed consortium: the French Society of Neurosurgery, which has created high-quality intellectual and scientific resources, the University of Limoges, the Dupuytren University Hospital Center in Limoges, the region of Limousin, and the French-language Virtual Medical University, which have provided logistic and financial support. To target appropriate levels at various users, we distinguished four groups: medical students, neurosurgery students, neurosurgeons (continuing medical education), and students in allied health fields. All areas of neurosurgery are concerned. All the courses, including tests for self-evaluation and scientific meetings (organized with information and communication technologies) are digitally recorded for the site. The principles that make it possible for a medical discipline to organize around an online project are: a pedagogical conception of projects built in the form of models reusable by other health specialties; a stronghold within professional societies of the relevant specialties able to create high-quality intellectual and scientific resources; an organization by educational levels that can be extended transversally to other health disciplines; and free

  7. A prospective comparison between three-dimensional magnetic resonance imaging and ventriculography for target-coordinate determination in frame-based functional stereotactic neurosurgery

    NARCIS (Netherlands)

    Schuurman, P. R.; de Bie, R. M.; Majoie, C. B.; Speelman, J. D.; Bosch, D. A.

    1999-01-01

    OBJECT: The purpose of this prospective study was to compare stereotactic coordinates obtained with ventriculography with coordinates derived from stereotactic computer-reconstructed three-dimensional magnetic resonance (3D-MR) imaging in functional stereotactic procedures. METHODS: In 15

  8. 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.

  9. 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.

  10. 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.

  11. Interactive computer graphics for stereotactic neurosurgery

    International Nuclear Information System (INIS)

    Goodman, J.H.; Davis, J.R.; Gahbauer, R.A.

    1986-01-01

    A microcomputer (IBM PC/AT) system has been developed to incorporate multiple image sources for stereotactic neurosurgery. Hard copy data is calibrated and captured with a video camera and frame grabber. Line contours are generated automatically on the basis of gray scale density or digitized manually. Interactive computer graphics provide a format with acceptable speed and accuracy for stereotactic neurosurgery. The ability to dimensionally integrate existing image data from multiple sources for target selection makes preoperative scans and scanner compatible head holders unnecessary. The system description and examples of use for brain tumor biopsy and brachytherapy ware presented

  12. Intraoperative Image Guidance in Neurosurgery: Development, Current Indications, and Future Trends

    International Nuclear Information System (INIS)

    Schulz, Ch.; Mauer, U.M.; Waldeck, S.

    2012-01-01

    Introduction. As minimally invasive surgery becomes the standard of care in neurosurgery, it is imperative that surgeons become skilled in the use of image-guided techniques. The development of image-guided neurosurgery represents a substantial improvement in the microsurgical treatment of tumors, vascular malformations, and other intracranial lesions. Objective. There have been numerous advances in neurosurgery which have aided the neurosurgeon to achieve accurate removal of pathological tissue with minimal disruption of surrounding healthy neuronal matter including the development of microsurgical, endoscopic, and endovascular techniques. Neuro navigation systems and intraoperative imaging should improve success in cranial neurosurgery. Additional functional imaging modalities such as PET, SPECT, DTI (for fiber tracking), and fMRI can now be used in order to reduce neurological deficits resulting from surgery; however the positive long-term effect remains questionable for many indications. Method. Pub Med database search using the search term “image guided neurosurgery.” More than 1400 articles were published during the last 25 years. The abstracts were scanned for prospective comparative trials. Results and Conclusion. 14 comparative trials are published. To date significant data amount show advantages in intraoperative accuracy influencing the perioperative morbidity and long-term outcome only for cerebral glioma surgery.

  13. 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.

  14. 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

  15. Neurosurgery for management of severe head injury

    International Nuclear Information System (INIS)

    Seitz, K.; Richter, H.P.

    1998-01-01

    Neurosurgery as a treatment of severe head injuries is not restricted to invasive surgery but also includes peri-operative intensive care medicine. Thanks to the technological progress and advanced diagnostic tools, especially drug treatments and their efficiency as well as risks can be far better monitored and analysed today. (orig./CB) [de

  16. 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.

  17. 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.

  18. Experimental data base for gamma-ray strength functions

    International Nuclear Information System (INIS)

    Kopecky, J.

    1999-01-01

    Theoretical and experimental knowledge of γ-ray strength functions is a very important ingredient for description and calculation of photon production data in all reaction channels. This study focusses on experimental γ-ray strength functions, collected over a period of about 40 years and based on measurements of partial radiative widths

  19. Experimental measurement of zero power reactor transfer function

    International Nuclear Information System (INIS)

    Liang Shuhong

    2011-01-01

    In order to study the zero power reactor (ZPR) transfer function, the ZPR transfer function expression was deduced with the point reactor kinetics equation, which was disturbed by reactivity input response. Based on the Fourier analysis for the input of triangular wave, the relation between the transfer function and reactivity was got. Validating research experiment was made on the DF-VI fast ZPR. After the disturbed reactivity was measured, the experimental value of the transfer function was got. According to the experimental value and the calculated value, the expression of the ZPR transfer function is proved, whereas the disturbed reactivity is got from the transfer function. (authors)

  20. The history of neurosurgery in Bolivia and pediatric neurosurgery in Santa Cruz de la Sierra.

    Science.gov (United States)

    Dabdoub, Carlos F; Dabdoub, Carlos B

    2013-09-25

    The practice of neurosurgery in Bolivia began thousands of years ago with skull trepanation. This procedure dates from the earliest period of the Tiwanaku culture, a preInca civilization. Neurosurgical development in Bolivia has its origins in the late 19(th) century and can be divided in two stages. At the beginning, before the advent of neurosurgery as a discipline, some general surgeons performed procedures on the skull and brain. Formal neurosurgery in Bolivia was developed with the arrival of neurosurgeons trained in the United States and some countries of South America. The Bolivian Neurosurgical Society was created in 1975. Nowadays, our national society has 74 members. It is affiliated with the World Federation of Neurosurgical Societies and the Latin American Federation of Neurosurgical Societies. Presently, neurosurgery in Bolivia is similar to that seen in developed countries. In this sense, government programs should dedicate more financial support to establish specialized healthcare centers where the management of complex central nervous system lesions could be offered. In contrast, we believe that encouraging the local training of young neurosurgeons is one of the most important factors in the development of neurosurgery in Bolivia or any other country.

  1. 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.

  2. Perioperative complications in endovascular neurosurgery: Anesthesiologist's perspective

    Science.gov (United States)

    Sharma, Megha U.; Ganjoo, Pragati; Singh, Daljit; Tandon, Monica S.; Agarwal, Jyotsna; Sharma, Durga P.; Jagetia, Anita

    2017-01-01

    Background: Endovascular neurosurgery is known to be associated with potentially serious perioperative complications that can impact the course and outcome of anesthesia. We present here our institutional experience in the anesthetic management of various endovascular neurosurgical procedures and their related complications over a 10-year period. Methods: Data was obtained in 240 patients pertaining to their preoperative status, details of anesthesia and surgery, perioperative course and surgery-related complications. Information regarding hemodynamic alterations, temperature variability, fluid-electrolyte imbalance, coagulation abnormalities and alterations in the anesthesia course was specifically noted. Results: Among the important complications observed were aneurysm rupture (2.5%), vasospasm (6.67%), thromboembolism (4.16%), contrast reactions, hemodynamic alterations, electrolyte abnormalities, hypothermia, delayed emergence from anesthesia, groin hematomas and early postoperative mortality (5.14%). Conclusion: Awareness of the unique challenges of endovascular neurosurgery and prompt and appropriate management of the associated complications by an experienced neuroanesthesiologist is vital to the outcome of these procedures. PMID:28413524

  3. 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.

  4. [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.

  5. [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.

  6. Graph theory analysis of complex brain networks: new concepts in brain mapping applied to neurosurgery.

    Science.gov (United States)

    Hart, Michael G; Ypma, Rolf J F; Romero-Garcia, Rafael; Price, Stephen J; Suckling, John

    2016-06-01

    Neuroanatomy has entered a new era, culminating in the search for the connectome, otherwise known as the brain's wiring diagram. While this approach has led to landmark discoveries in neuroscience, potential neurosurgical applications and collaborations have been lagging. In this article, the authors describe the ideas and concepts behind the connectome and its analysis with graph theory. Following this they then describe how to form a connectome using resting state functional MRI data as an example. Next they highlight selected insights into healthy brain function that have been derived from connectome analysis and illustrate how studies into normal development, cognitive function, and the effects of synthetic lesioning can be relevant to neurosurgery. Finally, they provide a précis of early applications of the connectome and related techniques to traumatic brain injury, functional neurosurgery, and neurooncology.

  7. Preoperative imaging as the basis for image-guided neurosurgery

    International Nuclear Information System (INIS)

    Winkler, D.; Strauss, G.; Hesse, S.; Sabri, O.; Goldammer, A.; Meixensberger, J.; Hund-Georgiadis, M.; Richter, A.; Kahn, T.

    2004-01-01

    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.) [de

  8. 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.

  9. 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.

  10. Mythological and Prehistorical Origins of Neurosurgery.

    Science.gov (United States)

    Nanda, Anil; Filis, Andreas; Kalakoti, Piyush

    2016-05-01

    Mythology has a cultural appeal, and the description of some neurosurgical procedures in the Hindu, Greek, Egyptian, and Chinese mythology has a bearing to the origins of our professions. The traces to some of our modern-day practices also can be linked back to the ancient prehistoric eras of the Siberian, Persian, and the Andean region. In this historical perspective, we briefly dwell into individual accounts through the prism of different cultures to highlight the development of neurosurgery in mythology and prehistoric era. Published by Elsevier Inc.

  11. CT-guided stereotactic neurosurgery

    International Nuclear Information System (INIS)

    Takizawa, Takaaki; Sato, Shoju; Matsumoto, Akira; Sano, Akira; Takahashi, Kazunori; Murakami, Yuji; Ohta, Kosuke

    1985-01-01

    Brown-Roberts-Wells stereotactic instruments were used for CT guided stereotactic surgery in 54 cases (65 operations). Stereotactic biopsy was done in 9 cases and successive regional chemotherapy was done in 3 cases. Stereotactic drainage was done in 2 cases of bacterial abcess, 3 cases of cystic neoplasm and 33 cases (43 operations) of intracerebral hematoma. CT guided stereotactic procedure was valuable for the correct cannulation to the center of the cavity. We tried to utilize CT image for the selection of targets for stereotactic functional neurosurgical procedures in 6 cases. In the cases of thalamotomy, the information derived from CT made the operation safer than that by contrast ventriculography alone. In all cases of electrode implantation for deep brain stimulation, accurate and precise electrode placement was achieved from CT images alone. This rapid and easy surgical technique was useful also for poor risk patients. (author)

  12. Virtual endoscopy in neurosurgery: a review.

    Science.gov (United States)

    Neubauer, André; Wolfsberger, Stefan

    2013-01-01

    Virtual endoscopy is the computerized creation of images depicting the inside of patient anatomy reconstructed in a virtual reality environment. It permits interactive, noninvasive, 3-dimensional visual inspection of anatomical cavities or vessels. This can aid in diagnostics, potentially replacing an actual endoscopic procedure, and help in the preparation of a surgical intervention by bridging the gap between plain 2-dimensional radiologic images and the 3-dimensional depiction of anatomy during actual endoscopy. If not only the endoscopic vision but also endoscopic handling, including realistic haptic feedback, is simulated, virtual endoscopy can be an effective training tool for novice surgeons. In neurosurgery, the main fields of the application of virtual endoscopy are third ventriculostomy, endonasal surgery, and the evaluation of pathologies in cerebral blood vessels. Progress in this very active field of research is achieved through cooperation between the technical and the medical communities. While the technology advances and new methods for modeling, reconstruction, and simulation are being developed, clinicians evaluate existing simulators, steer the development of new ones, and explore new fields of application. This review introduces some of the most interesting virtual reality systems for endoscopic neurosurgery developed in recent years and presents clinical studies conducted either on areas of application or specific systems. In addition, benefits and limitations of single products and simulated neuroendoscopy in general are pointed out.

  13. Case-control studies in neurosurgery.

    Science.gov (United States)

    Nesvick, Cody L; Thompson, Clinton J; Boop, Frederick A; Klimo, Paul

    2014-08-01

    Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting. The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure

  14. Anaesthesia and analgesia in Göttingen minipigs - examples of protocols used for neurosurgery and scanning procedures

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    Neurosurgery in Göttingen minipigs is often a welfare challenge, and therefore, the main goal of my talk will be to discuss how to improve animal welfare during brain surgery and the days following surgery. A combination of inhalation/infusion anaesthesia with opioids such as injections with bupr......Neurosurgery in Göttingen minipigs is often a welfare challenge, and therefore, the main goal of my talk will be to discuss how to improve animal welfare during brain surgery and the days following surgery. A combination of inhalation/infusion anaesthesia with opioids such as injections......, especially ensuring sufficient analgesia and water/food intake during the first hours and days. Compared to neurosurgery, scanning procedures are normally unproblematic from a welfare point of view. However, anaesthesia may influence the results of brain scans, particularly functional scans, such as positron...

  15. 21 CFR 882.4800 - Self-retaining retractor for neurosurgery.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Self-retaining retractor for neurosurgery. 882...-retaining retractor for neurosurgery. (a) Identification. A self-retaining retractor for neurosurgery is a self-locking device used to hold the edges of a wound open during neurosurgery. (b) Classification...

  16. [Experimental research on temporomandibular joint function in dysgnathic patients].

    Science.gov (United States)

    Hensel, S

    1990-10-01

    In an experimental study we examined the function of the TMJ of patients with a considerable aberration from ideal dynamic occlusion and with obvious symptoms of frontal dysgnathia. Using a measuring seat for the simultaneous recording of opening and closing movements without occlusal interference and the sounds produced by the TMJ, we could not find any significantly impaired TMJ function compared with an orthognathic control group of similar age.

  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. Copyright © 2017 by the Congress of Neurological Surgeons

  18. Versatile intraoperative MRI in neurosurgery and radiology.

    Science.gov (United States)

    Yrjänä, S K; Katisko, J P; Ojala, R O; Tervonen, O; Schiffbauer, H; Koivukangas, J

    2002-03-01

    Several models for the application of intra-operative magnetic resonance imaging (IMRI) have recently been reported, most of them unique. Two fundamental issues need to be addressed: optimal use of the scanner to ensure a wide base for research, development and clinical application, and an organisational model that facilitates such use. While in our setting the IMRI project was initiated by the neurosurgeons, the need for wider use of the facilities was recognised since the beginning of the planning phase in 1996. An organisational model was developed that allowed for development of neurosurgical applications, radiological imaging, and radiological interventions and for the research and development work of the vendor. A resistive 0.23 T MR scanner was installed in a dedicated operating room environment. Unique to this scanner is the ability to turn off the magnet, allowing for normal OR activities and devices, and to turn on the magnet as needed with a relatively short six-minute ramp up time. A staged surgical technique was perfected, allowing for transfer of data to the neuronavigator outside the scanner during surgery. In neurosurgery, IMRI was used as one part of a neuronavigational system that included ultrasound imaging, intra-operative cortical stimulation during awake procedures, electrocorticography and two neuronavigators. 34 neurosurgical cases included 27 brain tumour resections, 5 brain tumour biopsies, 1 extirpation of an arterio-venous malformation, and 1 haematoma evacuation. The scanner could also be used for normal clinical imaging where obese patients, children, claustophobic patients and postoperative control examinations were the major groups. The radiologists performed 110 interventions, including bone and abdominal biopsies, nerve root infiltrations and local pain therapies, with the optical needle tracking system under continuous MRI guidance. The organisational model allowed frequent use of the facilities for both neurosurgery and radiology

  19. Smartphone-assisted minimally invasive neurosurgery.

    Science.gov (United States)

    Mandel, Mauricio; Petito, Carlo Emanuel; Tutihashi, Rafael; Paiva, Wellingson; Abramovicz Mandel, Suzana; Gomes Pinto, Fernando Campos; Ferreira de Andrade, Almir; Teixeira, Manoel Jacobsen; Figueiredo, Eberval Gadelha

    2018-03-13

    OBJECTIVE Advances in video and fiber optics since the 1990s have led to the development of several commercially available high-definition neuroendoscopes. This technological improvement, however, has been surpassed by the smartphone revolution. With the increasing integration of smartphone technology into medical care, the introduction of these high-quality computerized communication devices with built-in digital cameras offers new possibilities in neuroendoscopy. The aim of this study was to investigate the usefulness of smartphone-endoscope integration in performing different types of minimally invasive neurosurgery. METHODS The authors present a new surgical tool that integrates a smartphone with an endoscope by use of a specially designed adapter, thus eliminating the need for the video system customarily used for endoscopy. The authors used this novel combined system to perform minimally invasive surgery on patients with various neuropathological disorders, including cavernomas, cerebral aneurysms, hydrocephalus, subdural hematomas, contusional hematomas, and spontaneous intracerebral hematomas. RESULTS The new endoscopic system featuring smartphone-endoscope integration was used by the authors in the minimally invasive surgical treatment of 42 patients. All procedures were successfully performed, and no complications related to the use of the new method were observed. The quality of the images obtained with the smartphone was high enough to provide adequate information to the neurosurgeons, as smartphone cameras can record images in high definition or 4K resolution. Moreover, because the smartphone screen moves along with the endoscope, surgical mobility was enhanced with the use of this method, facilitating more intuitive use. In fact, this increased mobility was identified as the greatest benefit of the use of the smartphone-endoscope system compared with the use of the neuroendoscope with the standard video set. CONCLUSIONS Minimally invasive approaches

  20. Altered monocyte function in experimental preeclampsia in the rat

    NARCIS (Netherlands)

    Faas, Marijke M.; Broekema, Martine; Moes, Henk; van der Schaaf, Gerda; Heineman, Maas Jan; de Vos, Paul

    2004-01-01

    OBJECTIVES: In the present study, we evaluated functional activity of monocytes in experimental preeclampsia induced by low-dose endotoxin infusion. STUDY DESIGN: Pregnant (n = 12) and cyclic rats (n = 12) were equipped with a permanent jugular vein cannula and infused with either low-dose endotoxin

  1. Influence of intraoperative magnetic resonance imaging used in neurosurgery on anesthesia

    Directory of Open Access Journals (Sweden)

    Mao-wei GONG

    2011-09-01

    Full Text Available Objective To observe the influcences of intraoperative magnetic resonance imaging(iMRI used in neurosurgery on anesthesia.Methods Sixty patients with glioma were randomly divided into two groups(30 each,the patients in iMRI group underwent craniotomy and glioma ablation under the guidance of iMRI and functional neuro-navigation,and in N group with the functional neuro-navigation only.The patients’ general status and concerning parameters were observed and recorded,including anesthesia duration,preparation time for surgery,duration of surgery,blood loss,volume of fluid administration,number of patients who needed blood transfusion,preoperative and postoperative hemoglobin,postoperative body temperature,dosage of muscle relaxant,and the unforeseen incidents related to iMRI and anesthesia.Results No significant differences existed between the two groups(P > 0.05 in patients’ general status,anesthesia duration,blood loss,volume of fluid administration,numbers of patients who needed blood transfusion,preoperative and postoperative hemoglobin,and body temperature.However,the preparation time for and duration of surgery were longer,the dosage of muscle relaxant was larger in iMRI group than in N group(P < 0.05.No inadvertent incident related to iMRI and anesthesia occurred in both groups.Conclusions The application of iMRI in neurosurgery may improve the accuracy in operative manipulation and make the tumor resection more thorough,but it may prolong duration of surgery.Other perimoperative care related to iMRI surgery is similar to that of traditional functional neuro-navigation surgery.Besides the basic rules of neurosurgery anesthetic management for neurosurgery,anesthetist should focus on anesthetic adjustment for a long operation.

  2. Overview of intraoperative MRI in neurosurgery

    International Nuclear Information System (INIS)

    Shiino, Akihiko; Matsuda, Masayuki

    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.)

  3. 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.)

  4. 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.

  5. Evolving virtual reality simulation in neurosurgery.

    Science.gov (United States)

    Schirmer, Clemens M; Mocco, J; Elder, J Bradley

    2013-10-01

    Virtual reality (VR) applications promise the safe, efficacious, and valid replication of scenarios encountered in modern neurosurgery, and a number of navigation- or dissection-related and endovascular simulators have been successfully deployed in the last 2 decades. Concurrently, neurosurgical training is changing, and VR simulations are expected to play a part in future training. To give an overview of currently available neurosurgical VR applications in the spectrum of desired applications and the outlook of the requirements to be met by future applications. The available literature was analyzed using structured Medline and PubMed searches. Relevant articles were retrieved and reviewed. When quantitative results were available, effect sizes were collated or estimated to check for publication bias. There has been a significant increase in publications concerning the use of VR in neurosurgery in the last 22 years (P < .001). Thirty-eight of 117 publications (32%) identified reported data regarding the use of a simulator by practitioners; 35 of these were reported as positive trials (92%). Twenty-two of 38 studies (58%) reported quantitative data with mostly small positive effect sizes (median, 1.41; interquartile range, 1.08-2). The use of VR simulators in endovascular surgery has the most robust basis, with 65% of studies reporting quantitative outcomes. Current neurosurgical VR applications focus on basic procedural skill acquisition and are valid and efficacious adjuncts to neurosurgical training. In the future, the development of complex procedural simulators, teamwork, and focus on validated measures will lead to robust framework of the use of VR over the entire career of a neurosurgeon.

  6. The 2015 AANS Presidential Address: Neurosurgery's founding principles.

    Science.gov (United States)

    Harbaugh, Robert E

    2015-12-01

    These are turbulent times for American neurosurgery. It is important to look ahead and prepare for the future but it is also important to look back-for it is memory and tradition that prevent the tyranny of the present. It is impossible to know where we are going if we don't remember where we were. In this paper I want to discuss the founding principles of neurosurgery-the principles that have allowed neurosurgery to prosper in its first century-and to stress the importance of adhering to these principles in times of change. I also want to talk to you about how the American Association of Neurological Surgeons (AANS) is helping neurosurgeons honor our founding principles, while preparing neurosurgery for its second century.

  7. Experimental investigation of statistical density function of decaying radioactive sources

    International Nuclear Information System (INIS)

    Salma, I.; Zemplen-Papp, E.

    1991-01-01

    The validity of the Poisson and the λ P(k) modified Poisson statistical density functions of observing k events in a short time interval is investigated experimentally in radioactive decay detection for various measuring times. The experiments to measure radioactive decay were performed with 89m Y, using a multichannel analyzer. According to the results, Poisson statistics adequately describes the counting experiment for short measuring times. (author) 13 refs.; 4 figs

  8. 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

    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.

  9. Aura of technology and the cutting edge: a history of lasers in neurosurgery.

    Science.gov (United States)

    Ryan, Robert W; Spetzler, Robert F; Preul, Mark C

    2009-09-01

    In this historical review the authors examine the important developments that have led to the availability of laser energy to neurosurgeons as a unique and sometimes invaluable tool. They review the physical science behind the function of lasers, as well as how and when various lasers based on different lasing mediums were discovered. They also follow the close association between advances in laser technology and their application in biomedicine, from early laboratory experiments to the first clinical experiences. Because opinions on the appropriate role of lasers in neurosurgery vary widely, the historical basis for some of these views is explored. Initial enthusiasm for a technology that appears to have innate advantages for safe resections has often given way to the strict limitations and demands of the neurosurgical operating theater. However, numerous creative solutions to improve laser delivery, power, safety, and ergonomics demonstrate the important role that technological advances in related scientific fields continue to offer neurosurgery. Benefiting from the most recent developments in materials science, current CO(2) laser delivery systems provide a useful addition to the neurosurgical armamentarium when applied in the correct circumstances and reflect the important historical advances that come about from the interplay between neurosurgery and technology.

  10. Evolution in Practice: How has British Neurosurgery Changed in the Last 10 Years?

    Science.gov (United States)

    Tarnaris, A; Arvin, B; Ashkan, K

    2008-01-01

    INTRODUCTION Neurosurgery is a fast-evolving surgical subspecialty driven by technological advances, socio-economic factors and patient expectations. In this study, we have compared the work-load volume in a single institution in the years of 1994 and 2004 and commented on the possible reasons for the changes and the impacts they may have for the future. PATIENTS AND METHODS A retrospective, log-book review of all operations performed in the years 1994 and 2004 in a single, tertiary, neurosurgical centre was performed. RESULTS Neurosurgical practice has evolved over this period. Current practice has moved away from clipping of aneurysms and towards coil embolisation performed by interventional radiologists. Electrode stimulation of deep brain regions for movement disorders is the current practice, whereas 10 years ago the same disorders were dealt with by lesioning of the relevant regions. In spinal neurosurgery, instrumentation is increasingly favoured currently. In the field of neuro-oncology, current practice favours minimal access to the target area by the use of stereotactic localisation. CONCLUSIONS Changes were most pronounced in the subspecialties of vascular, functional and spinal neurosurgery within this 10-year period. Knowledge of such dynamics is valuable in health resource management as well as planning for neurosurgical training programmes. PMID:18765031

  11. 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.

  12. 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.

  13. 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.

  14. Patterns in neurosurgical adverse events: endovascular neurosurgery.

    Science.gov (United States)

    Wong, Judith M; Ziewacz, John E; Panchmatia, Jaykar R; Bader, Angela M; Pandey, Aditya S; Thompson, B Gregory; Frerichs, Kai; Gawande, Atul A

    2012-11-01

    As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in endovascular neurosurgery concerning the frequency of adverse events in practice, their patterns, and current methods of reducing the occurrence of these events. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice. Based on a review of the literature, thromboembolic events appeared to be the most common adverse events in endovascular neurosurgery, with a reported incidence ranging from 2% to 61% depending on aneurysm rupture status and mode of detection of the event. Intraprocedural and periprocedural prevention and rescue regimens are advocated to minimize this risk; however, evidence on the optimal use of anticoagulant and antithrombotic agents is limited. Furthermore, it is unknown what proportion of eligible patients receive any prophylactic treatment. Groin-site hematoma is the most common access-related complication. Data from the cardiac literature indicate an overall incidence of 9% to 32%, but data specific to neuroendovascular therapy are scant. Manual compression, compression adjuncts, and closure devices are used with varying rates of success, but no standardized protocols have been tested on a broad scale. Contrast-induced nephropathy is one of the more common causes of hospital-acquired renal insufficiency, with an incidence of 30% in high-risk patients after contrast administration. Evidence from medical fields supports the use of various preventive strategies. Intraprocedural vessel rupture is infrequent, with the reported incidence ranging from 1% to 9%, but it is potentially devastating. Improvements in device technology combined with proper endovascular technique play an important role in reducing

  15. 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

  16. Experimental studies on the heavy quark fragmentation functions

    International Nuclear Information System (INIS)

    Bethke, S.

    1985-07-01

    The influence of perturbative QCD gluon radiation and initial state photon radiation on the experimental determination of the heavy quark fragmentation functions is studied in order to extract , the mean of the charm fragmentation function, from the recent measurements of inclusive Dsup(*) production in e + e - annihilation processes. The result is =0.71+-0.014+-0.03, which is scale invariant in the c.m. energy range of 10 GeV to 34 GeV. This result is interpreted in terms of kinematical calculations on heavy quark fragmentation and also compared with results from ν-N-reactions and from investigations of inclusive lepton production in e + e - annihilation. Results of a QCD shower model are in good agreement with the data and offer an alternative description of phenomenological fragmentation functions. (orig.)

  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. 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.

  19. Standards for reporting randomized controlled trials in neurosurgery.

    Science.gov (United States)

    Kiehna, Erin N; Starke, Robert M; Pouratian, Nader; Dumont, Aaron S

    2011-02-01

    The Consolidated Standards for Reporting of Trials (CONSORT) criteria were published in 1996 to standardize the reporting and improve the quality of clinical trials. Despite having been endorsed by major medical journals and shown to improve the quality of reported trials, neurosurgical journals have yet to formally adopt these reporting criteria. The purpose of this study is to evaluate the quality and reporting of randomized controlled trials (RCTs) in neurosurgery and the factors that may affect the quality of reported trials. The authors evaluated all neurosurgical RCTs published in 2006 and 2007 in the principal neurosurgical journals (Journal of Neurosurgery; Neurosurgery; Surgical Neurology; Journal of Neurology, Neurosurgery, and Psychiatry; and Acta Neurochirurgica) and in 3 leading general medical journals (Journal of the American Medical Association, Lancet, and the New England Journal of Medicine). Randomized controlled trials that addressed operative decision making or the treatment of neurosurgical patients were included in this analysis. The RCT quality was evaluated using the Jadad score and the CONSORT checklist. In 2006 and 2007, 27 RCTs relevant to intracranial neurosurgery were reported. Of these trials, only 59% had a Jadad score ≥ 3. The 3 major medical journals all endorsed the CONSORT guidelines, while none of the neurosurgical journals have adopted these guidelines. Randomized controlled trials published in the 3 major medical journals had a significantly higher mean CONSORT score (mean 41, range 39-44) compared with those published in neurosurgical journals (mean 26.4, range 17-38; p journals (mean 3.42, range 2-5) than neurosurgical journals (mean 2.45, range 1-5; p = 0.05). Despite the growing volume of RCTs in neurosurgery, the quality of reporting of these trials remains suboptimal, especially in the neurosurgical journals. Improved awareness of the CONSORT guidelines by journal editors, reviewers, and authors of these papers could

  20. 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.

  1. Prophylactic antibiotics and anticonvulsants in neurosurgery.

    Science.gov (United States)

    Ratilal, B; Sampaio, C

    2011-01-01

    The prophylactic administration of antibiotics to prevent infection and the prophylactic administration of anticonvulsants to prevent first seizure episodes are common practice in neurosurgery. If prophylactic medication therapy is not indicated, the patient not only incurs the discomfort and the inconvenience resulting from drug treatment but is also unnecessarily exposed to adverse drug reactions, and incurs extra costs. The main situations in which prophylactic anticonvulsants and antibiotics are used are described and those situations we found controversial in the literature and lack further investigation are identified: anticonvulsants for preventing seizures in patients with chronic subdural hematomas, antiepileptic drugs for preventing seizures in those suffering from brain tumors, antibiotic prophylaxis for preventing meningitis in patients with basilar skull fractures, and antibiotic prophylaxis for the surgical introduction of intracranial ventricular shunts.In the following we present systematic reviews of the literature in accordance with the standard protocol of The Cochrane Collaboration to evaluate the effectiveness of the use of these prophylactic medications in the situations mentioned. Our goal was to efficiently integrate valid information and provide a basis for rational decision-making.

  2. 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.

  3. [Exocrine function of the pancreas in rats with experimental obesity].

    Science.gov (United States)

    Leshchenko, I V; Shevchuk, V H; Savcheniuk, O A; Falalieieva, T M; Sukhodolia, S A; Berehova, T V

    2014-01-01

    The influence of neonatal administration of hyperosmolar sodium chloride and sodium glutamate on the exocrine function of the pancreas in rats has been investigated. It was observed the development of acute pancreatitis under experimental obesity. The cross-section area of acini reduced by 12%, the cross-section area of acinocytes nuclei increased by 10%, the length between the lobes of the gland has grown by 48%. The level of amylase was increased by 43%, the levels of pancreatic amylase and lipase were increased by 68% and 24%, respectively.

  4. Rapidly photo-cross-linkable chitosan hydrogel for peripheral neurosurgeries.

    Science.gov (United States)

    Rickett, Todd A; Amoozgar, Zohreh; Tuchek, Chad A; Park, Joonyoung; Yeo, Yoon; Shi, Riyi

    2011-01-10

    Restoring continuity to severed peripheral nerves is crucial to regeneration and enables functional recovery. However, the two most common agents for coaptation, sutures and fibrin glues, have drawbacks such as inflammation, pathogenesis, and dehiscence. Chitosan-based adhesives are a promising alternative, reported to have good cytocompatibility and favorable immunogenicity. A photo-cross-linkable hydrogel based on chitosan is proposed as a new adhesive for peripheral nerve anastomosis. Two Az-chitosans were synthesized by conjugating 4-azidobenzoic acid with low (LMW, 15 kDa) and high (HMW, 50-190 kDa) molecular weight chitosans. These solutions formed a hydrogel in less than 1 min under UV light. The LMW Az-chitosan was more tightly cross-linked than the HMW variant, undergoing significantly less swelling and possessing a higher rheological storage modulus, and both Az-chitosan gels were stiffer than commercial fibrin glue. Severed nerves repaired by Az-chitosan adhesives tolerated longitudinal forces comparable or superior to fibrin glue. Adhesive exposure to intact nerves and neural cell culture showed both Az-chitosans to be nontoxic in the acute (minutes) and chronic (days) time frames. These results demonstrate that Az-chitosan hydrogels are cytocompatible and mechanically suitable for use as bioadhesives in peripheral neurosurgeries.

  5. Experimental studies of renal blood flow by digitized functional angiography

    International Nuclear Information System (INIS)

    Buersch, J.H.; Ochs, C.; Hahne, H.J.; Heintzen, P.H.

    1985-01-01

    New techniques of digital image processing have been experimentally tested for the assessment of renal blood flow. The underlying principle in functional angiography is the extraction of flow parameters. Basically, density-time variations of the contrast medium are analayzed from to each picture element of a 256x256 matrix. The real-time acquisition rate of images was 25/sec. For the calculation of angiographic flow a PDP 11/40 computer was used to interactively perform a time dependent segmentation of the renal arteries and the aorta. Subsequently, volume flow was calculated in relative units for the specific vascular segments under study. 15 control angiograms were made in 5 animals with cardiac output ranging between 0.8 to 2.2l/min. Unilateral renal blood flow was calculated as 24+-3.4% of pre-renal aortic flow without systematic side differences. Reproducibility from repeated flow measurements showed an SD of +-1.8% of the individual pre-renal aortic flow. Renal flow was also measured in 3 animals with an experimentally created 50% flow reduction of the left kidney. Angiographic flow in the left renal artery dropped to 12+-2% of pre-renal flow. The present experimental data suggest that digital angiography has sufficient diagnostic capabilities for the detection of abnormal renal blood flow. The technique may serve as a useful diagnostic adjunct to conventional angiography and has the potential of assisting in the evaluation of renal vascular hypertension. (orig.) [de

  6. 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.

  7. Microvascular Anastomosis Training in Neurosurgery: A Review

    Directory of Open Access Journals (Sweden)

    Vadim A. Byvaltsev

    2018-01-01

    Full Text Available Cerebrovascular diseases are among the most widespread diseases in the world, which largely determine the structure of morbidity and mortality rates. Microvascular anastomosis techniques are important for revascularization surgeries on brachiocephalic and carotid arteries and complex cerebral aneurysms and even during resection of brain tumors that obstruct major cerebral arteries. Training in microvascular surgery became even more difficult with less case exposure and growth of the use of endovascular techniques. In this text we will briefly discuss the history of microvascular surgery, review current literature on simulation models with the emphasis on their merits and shortcomings, and describe the views and opinions on the future of the microvascular training in neurosurgery. In “dry” microsurgical training, various models created from artificial materials that simulate biological tissues are used. The next stage in training more experienced surgeons is to work with nonliving tissue models. Microvascular training using live models is considered to be the most relevant due to presence of the blood flow. Training on laboratory animals has high indicators of face and constructive validity. One of the future directions in the development of microsurgical techniques is the use of robotic systems. Robotic systems may play a role in teaching future generations of microsurgeons. Modern technologies allow access to highly accurate learning environments that are extremely similar to real environment. Additionally, assessment of microsurgical skills should become a fundamental part of the current evaluation of competence within a microneurosurgical training program. Such an assessment tool could be utilized to ensure a constant level of surgical competence within the recertification process. It is important that this evaluation be based on validated models.

  8. Robot-assisted procedures in pediatric neurosurgery.

    Science.gov (United States)

    De Benedictis, Alessandro; Trezza, Andrea; Carai, Andrea; Genovese, Elisabetta; Procaccini, Emidio; Messina, Raffaella; Randi, Franco; Cossu, Silvia; Esposito, Giacomo; Palma, Paolo; Amante, Paolina; Rizzi, Michele; Marras, Carlo Efisio

    2017-05-01

    OBJECTIVE During the last 3 decades, robotic technology has rapidly spread across several surgical fields due to the continuous evolution of its versatility, stability, dexterity, and haptic properties. Neurosurgery pioneered the development of robotics, with the aim of improving the quality of several procedures requiring a high degree of accuracy and safety. Moreover, robot-guided approaches are of special interest in pediatric patients, who often have altered anatomy and challenging relationships between the diseased and eloquent structures. Nevertheless, the use of robots has been rarely reported in children. In this work, the authors describe their experience using the ROSA device (Robotized Stereotactic Assistant) in the neurosurgical management of a pediatric population. METHODS Between 2011 and 2016, 116 children underwent ROSA-assisted procedures for a variety of diseases (epilepsy, brain tumors, intra- or extraventricular and tumor cysts, obstructive hydrocephalus, and movement and behavioral disorders). Each patient received accurate preoperative planning of optimal trajectories, intraoperative frameless registration, surgical treatment using specific instruments held by the robotic arm, and postoperative CT or MR imaging. RESULTS The authors performed 128 consecutive surgeries, including implantation of 386 electrodes for stereo-electroencephalography (36 procedures), neuroendoscopy (42 procedures), stereotactic biopsy (26 procedures), pallidotomy (12 procedures), shunt placement (6 procedures), deep brain stimulation procedures (3 procedures), and stereotactic cyst aspiration (3 procedures). For each procedure, the authors analyzed and discussed accuracy, timing, and complications. CONCLUSIONS To the best their knowledge, the authors present the largest reported series of pediatric neurosurgical cases assisted by robotic support. The ROSA system provided improved safety and feasibility of minimally invasive approaches, thus optimizing the surgical

  9. Teleradiology in neurosurgery, based on the experience of the Department of Neurosurgery, Polish Academy of Sciences

    International Nuclear Information System (INIS)

    Glowacki, M.; Czernicki, Z.; Jurkiewicz, J.; Walasek, N.; Czernicki, Z.; Jurkiewicz, J.

    2005-01-01

    The aim of the study was to analyze experience with the teleconsulting system applied at the Department of Neurosurgery, Polish Academy of Sciences (PAN) and to establish the best medical and economic conditions for teleradiological networks. The presented system is based on frame-grabbing technology and is operated by MultiView TM 2.0D (eMeD, Tech.) software. Computed tomography (CT) examinations performed in the hospitals in Ciechanow or Ostroleka are transmitted to the teleconsulting center in the Department of Neurosurgery, PAN. Regular telephone lines with a transmission speed of 56 kbps are utilized. One whole CT examination is transmitted in 5 to 7 minutes. All clinical information is reported during telephone conversation optimized by a specific questionnaire which helps improve arrangements for neurosurgical intervention and to document consultations. The usefulness of mobile phones and e mail in teleradiology was also evaluated.The period from December 1996 to April 2002 was studied. During this time, 931 transmission were performed. The most common were control examinations (26%), followed by neurotrauma (19%), spontaneous intracerebral hemorrhage (18%), neurooncology (13%), subarachnoidal hemorrhage (7%), hydrocephalus (5%), cerebral ischemia (3%), and those without any intracranial pathologies (4%). Disturbances were observed in 4% of transmissions. Seventy percent of the consulted patients were treated conservatively in remote hospitals. Thirty percent of the cases were admitted to our department, of whom 86% were operated. Mobile phones were found to be a useful tool in urgent neurosurgical consultations. Sending compressed CT images via e mail provided sufficient quality,but requires a particular technical background. The system allows for: 1) proper qualification for neurosurgical treatment, 2) fast and easy access to consultations with specialists, 3) patient follow-up (repeated consultations),4) avoidance of unnecessary transportation, and 5

  10. 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.

  11. Network inference from functional experimental data (Conference Presentation)

    Science.gov (United States)

    Desrosiers, Patrick; Labrecque, Simon; Tremblay, Maxime; Bélanger, Mathieu; De Dorlodot, Bertrand; Côté, Daniel C.

    2016-03-01

    Functional connectivity maps of neuronal networks are critical tools to understand how neurons form circuits, how information is encoded and processed by neurons, how memory is shaped, and how these basic processes are altered under pathological conditions. Current light microscopy allows to observe calcium or electrical activity of thousands of neurons simultaneously, yet assessing comprehensive connectivity maps directly from such data remains a non-trivial analytical task. There exist simple statistical methods, such as cross-correlation and Granger causality, but they only detect linear interactions between neurons. Other more involved inference methods inspired by information theory, such as mutual information and transfer entropy, identify more accurately connections between neurons but also require more computational resources. We carried out a comparative study of common connectivity inference methods. The relative accuracy and computational cost of each method was determined via simulated fluorescence traces generated with realistic computational models of interacting neurons in networks of different topologies (clustered or non-clustered) and sizes (10-1000 neurons). To bridge the computational and experimental works, we observed the intracellular calcium activity of live hippocampal neuronal cultures infected with the fluorescent calcium marker GCaMP6f. The spontaneous activity of the networks, consisting of 50-100 neurons per field of view, was recorded from 20 to 50 Hz on a microscope controlled by a homemade software. We implemented all connectivity inference methods in the software, which rapidly loads calcium fluorescence movies, segments the images, extracts the fluorescence traces, and assesses the functional connections (with strengths and directions) between each pair of neurons. We used this software to assess, in real time, the functional connectivity from real calcium imaging data in basal conditions, under plasticity protocols, and epileptic

  12. Vascular and renal function in experimental thyroid disorders.

    Science.gov (United States)

    Vargas, Félix; Moreno, Juan Manuel; Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Osuna, Antonio; Alvarez-Guerra, Miriam; García-Estañ, Joaquín

    2006-02-01

    This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism. The hypothyroid state is accompanied by a marked decrease in sensitivity to vasoconstrictors, especially to sympathetic agonists, alteration that may play a role in the reduced blood pressure of hypothyroid rats, as well as in the preventive effects of hypothyroidism on experimental hypertension. Moreover, in hypothyroid rats, the endothelium-dependent and nitric oxide donors vasodilation is reduced. Conversely, the vessels from hyperthyroid rats showed an increased endothelium-dependent responsiveness that may be secondary to the shear-stress induced by the hyperdynamic circulation, and that may contribute to the reduced vascular resistance characteristic of this disease. Thyroid hormones also have important effects in the kidney, affecting renal growth, renal haemodynamics, and salt and water metabolism. In hyperthyroidism, there is a resetting of the pressure-natriuresis relationship related to hyperactivity of the renin-angiotensin system, which contributes to the arterial hypertension associated with this endocrine disease. Moreover, thyroid hormones affect the development and/or maintenance of various forms of arterial hypertension. This review also describes recent advances in our understanding of thyroid hormone action on nitric oxide and oxidative stress in the regulation of cardiovascular and renal function and in the long-term control of blood pressure.

  13. 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

  14. BOOK REVIEW: Neurosurgery in the Tropics: A practical approach ...

    African Journals Online (AJOL)

    BOOK REVIEW: Neurosurgery in the Tropics: A practical approach to common problems By Jeffrey V. Rosenfeld MBBS, MS, FRACS, FRCS (Ed), FACS, FACTM and David A.K Watters ChM, FRACS, FRCS (Ed) Macmillan Education LTD 2000, Price $ 50 US ISBN 0-333-68412-5.

  15. Demographics, Interests, and Quality of Life of Canadian Neurosurgery Residents.

    Science.gov (United States)

    Iorio-Morin, Christian; Ahmed, Syed Uzair; Bigder, Mark; Dakson, Ayoub; Elliott, Cameron; Guha, Daipayan; Kameda-Smith, Michelle; Lavergne, Pascal; Makarenko, Serge; Taccone, Michael S; Tso, Michael K; Wang, Bill; Winkler-Schwartz, Alexander; Fortin, David

    2018-03-01

    Neurosurgical residents face a unique combination of challenges, including long duty hours, technically challenging cases, and uncertain employment prospects. We sought to assess the demographics, interests, career goals, self-rated happiness, and overall well-being of Canadian neurosurgery residents. A cross-sectional survey was developed and sent through the Canadian Neurosurgery Research Collaborative to every resident enrolled in a Canadian neurosurgery program as of April 1, 2016. We analyzed 76 completed surveys of 146 eligible residents (52% response rate). The median age was 29 years, with 76% of respondents being males. The most popular subspecialties of interest for fellowship were spine, oncology, and open vascular neurosurgery. The most frequent self-reported number of worked hours per week was the 80- to 89-hour range. The majority of respondents reported a high level of happiness as well as stress. Sense of accomplishment and fatigue were reported as average to high and overall quality of life was low for 19%, average for 49%, and high for 32%. Satisfaction with work-life balance was average for 44% of respondents and was the only tested domain in which significant dissatisfaction was identified (18%). Overall, respondents were highly satisfied with their choice of specialty, choice of program, surgical exposure, and work environment; however, intimidation was reported in 36% of respondents and depression by 17%. Despite a challenging residency and high workload, the majority of Canadian neurosurgery residents are happy and satisfied with their choice of specialty and program. However, work-life balance, employability, resident intimidation, and depression were identified as areas of active concern.

  16. Past, Present, and Future of Neurosurgery in Uganda.

    Science.gov (United States)

    Haglund, Michael M; Warf, Benjamin; Fuller, Anthony; Freischlag, Kyle; Muhumuza, Michael; Ssenyonjo, Hussein; Mukasa, John; Mugamba, John; Kiryabwire, Joel

    2017-04-01

    Neurosurgery in Uganda was virtually non-existent up until late 1960s. This changed when Dr. Jovan Kiryabwire spearheaded development of a neurosurgical unit at Mulago Hospital in Kampala. His work ethic and vision set the stage for rapid expansion of neurosurgical care in Uganda.At the beginning of the 2000s, Uganda was a country of nearly 30 million people, but had only 4 neurosurgeons. Neurosurgery's progress was plagued by challenges faced by many developing countries, such as difficulty retaining specialists, lack of modern hospital resources, and scarce training facilities. To combat these challenges 2 distinct programs were launched: 1 by Dr. Benjamin Warf in collaboration with CURE International, and the other by Dr. Michael Haglund from Duke University. Dr. Warf's program focused on establishing a facility for pediatric neurosurgery. Dr. Haglund's program to increase neurosurgical capacity was founded on a "4 T's Paradigm": Technology, Twinning, Training, and Top-Down. Embedded within this paradigm was the notion that Uganda needed to train its own people to become neurosurgeons, and thus Duke helped establish the country's first neurosurgery residency training program.Efforts from overseas, including the tireless work of Dr. Benjamin Warf, have saved thousands of children's lives. The influx of the Duke Program caused a dynamic shift at Mulago Hospital with dramatic effects, as evidenced by the substantial increase in neurosurgical capacity. The future looks bright for neurosurgery in Uganda and it all traces back to a rural village where 1 man had a vision to help the people of his country. Copyright © 2017 by the Congress of Neurological Surgeons.

  17. 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.

  18. Thin-film electroencephalographic electrodes using multi-walled carbon nanotubes are effective for neurosurgery.

    Science.gov (United States)

    Awara, Kousuke; Kitai, Ryuhei; Isozaki, Makoto; Neishi, Hiroyuki; Kikuta, Kenichiro; Fushisato, Naoki; Kawamoto, Akira

    2014-12-15

    Intraoperative morphological and functional monitoring is essential for safe neurosurgery. Functional monitoring is based on electroencephalography (EEG), which uses silver electrodes. However, these electrodes generate metal artifacts as silver blocks X-rays, creating white radial lines on computed tomography (CT) images during surgery. Thick electrodes interfere with surgical procedures. Thus, thinner and lighter electrodes are ideal for intraoperative use. The authors developed thin brain electrodes using carbon nanotubes that were formed into thin sheets and connected to electrical wires. The nanotube sheets were soft and fitted the curve of the head very well. When attached to the head using paste, the impedance of the newly developed electrodes was 5 kΩ or lower, which was similar to that of conventional metal electrodes. These electrodes can be used in combination with intraoperative CT, magnetic resonance imaging (MRI), or cerebral angiography. Somatosensory-evoked potentials, auditory brainstem responses, and visually evoked potentials were clearly identified in ten volunteers. The electrodes, without any artifacts that distort images, did not interfere with X-rays, CT, or MR images. They also did not cause skin damage. Carbon nanotube electrodes may be ideal for neurosurgery.

  19. Role of gamma knife radiosurgery in neurosurgery. Past and future perspectives

    International Nuclear Information System (INIS)

    Koga, Tomoyuki; Shin, Masahiro; Saito, Nobuhito

    2010-01-01

    The gamma knife was the first radiosurgical device developed at the Karolinska Institute in 1967. Stereotactic radiosurgery using the gamma knife has been widely accepted in clinical practice and has contributed to the development of neurosurgery. More than 500,000 patients have been treated by gamma knife stereotactic radiosurgery so far, and the method is now an indispensable neurosurgical tool. Here we review long-term outcomes and development of stereotactic radiosurgery using the gamma knife and discuss its future perspectives. The primary role of stereotactic radiosurgery is to control small well-demarcated lesions such as metastatic brain tumors, meningiomas, schwannomas, and pituitary adenomas while preserving the function of surrounding brain tissue. The gamma knife has been used as a primary treatment or in combination with surgery, and some applications have been accepted as standard treatment in the field of neurosurgery. Treatment of cerebral arteriovenous malformations has also been drastically changed after emergence of this technology. Controlling functional disorders is another role of stereotactic radiosurgery. There is a risk of radiation-induced adverse events, which are usually mild and less frequent. However, especially in large or invasive lesions, those risks are not negligible and pose limitations. Advancement of irradiation technology and dose planning software have enabled more sophisticated and safer treatment, and further progress will contribute to better treatment outcomes not only for brain lesions but also for cervical lesions with less invasive treatment. (author)

  20. [The woman in neurosurgery at the national institute of neurology and neurosurgery].

    Science.gov (United States)

    Mejía-Pérez, Sonia Iliana; Cervera-Martínez, Claudia; Sánchez-Correa, Thalía Estefanía; Corona-Vázquezo, Teresa

    Women have always had a hard time in the history of medicine; Dr. Isabel Blackwell was the first woman in history to practice medicine. Dr. Diana Beck became the world´s first female neurosurgeon. The first Latin American female neurosurgeon was Dr. María Cristina García Sancho y Álvarez-Tostado. All of these women had to face a large number of social, cultural, and economic obstacles in their path; however, this situation has changed gradually. Dr. Ana Lilia Siordia Karam was the first neurosurgeon to graduate from INNN. Nineteen years later the second female neurosurgeon at this institute was Dr. María Petra Herrera Guerrero. During their time at this institute they endured a lot of difficulties, especially with most of their coworkers; however, some coworkers treated them with respect and no gender distinction. Nowadays, four of the 25 total neurosurgery residents at INNN are women, and even though some of them have had to endure acts of gender discrimination, the general situation has changed. With work and respect, women have managed to have a larger role in the surgical field. We hope that in the near future a gender discrimination-free environment will be achieved in medicine and its specialties.

  1. Readiness for practice: a survey of neurosurgery graduates and program directors.

    Science.gov (United States)

    Haji, Faizal A; Steven, David A

    2014-11-01

    Postgraduate neurosurgical education is undergoing significant reform, including transition to a competency-based training model. To support these efforts, the purpose of this study was to determine neurosurgical graduates' and program directors' (PDs) opinions about graduates' level of competence in reference to the 2010 Royal College Objectives of Training in Neurosurgery. An electronic survey was distributed to Canadian neurosurgery PDs and graduates from 2011. The questionnaire addressed graduates' abilities in nonprocedural knowledge and skills, CanMEDS roles, proficiency with core neurosurgical procedures and knowledge of complex neurosurgical techniques. Thirteen of 22 (59%) graduate and 17/25 (65%) PD surveys were completed. There were no significant differences between PD and graduate responses. Most respondents agreed that these graduates possess the knowledge and skills expected of an independently practicing neurosurgeon across current objectives of training. A small proportion felt some graduates did not achieve this level of proficiency on specific vascular, functional, peripheral nerve and endoscopic procedures. This was partially attributed to limited exposure to these procedures during training and perceptions that some techniques required fellowship-level training. Graduating neurosurgical residents are perceived to possess a high level of proficiency in the majority of neurosurgical practice domains. Inadequate exposure during training or a perception that subspecialists should perform some procedures may contribute to cases where proficiency is not as high. The trends identified in this study could be monitored on an ongoing basis to provide supplemental data to guide curricular decisions in Canadian neurosurgical training.

  2. 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.

  3. A glance at live interventional neuroradiology and neurosurgery course 2009

    International Nuclear Information System (INIS)

    Li Qiang; Hong Bo; Liu Jianmin

    2010-01-01

    The annual Live Interventional Neuroradiology and Neurosurgery Course (LINNC) is one of the most important congresses in the neurosurgery and neuroradiology field. LINNC 2009 was held on May 25th this year and lasted for 3 days. In this article, the authors introduced the main points of the congress. The congress mainly discussed some hot topics at present time, including both the clinical and fundamental studies of cerebral arteriovenous malformation, ischemic cerebral disease and intracranial aneurysm, etc. Both neurological and neuroradiological case demonstrations related to the topics, and the main course of the congress were alternately performed. Recent advances in imaging technique and clinical application, such as Dyna-CT and Xper-CT, were also presented on the congress. (authors)

  4. Preoperative anemia increases postoperative morbidity in elective cranial neurosurgery

    Science.gov (United States)

    Bydon, Mohamad; Abt, Nicholas B.; Macki, Mohamed; Brem, Henry; Huang, Judy; Bydon, Ali; Tamargo, Rafael J.

    2014-01-01

    Background: Preoperative anemia may affect postoperative mortality and morbidity following elective cranial operations. Methods: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was used to identify elective cranial neurosurgical cases (2006-2012). Morbidity was defined as wound infection, systemic infection, cardiac, respiratory, renal, neurologic, and thromboembolic events, and unplanned returns to the operating room. For 30-day postoperative mortality and morbidity, adjusted odds ratios (ORs) were estimated with multivariable logistic regression. Results: Of 8015 patients who underwent elective cranial neurosurgery, 1710 patients (21.4%) were anemic. Anemic patients had an increased 30-day mortality of 4.1% versus 1.3% in non-anemic patients (P neurosurgery was independently associated with an increased risk of 30-day postoperative mortality and morbidity when compared to non-anemic patients. A hematocrit level below 33% (Hgb 11 g/dl) was associated with a significant increase in postoperative morbidity. PMID:25422784

  5. Cerenkov and radioluminescence imaging of brain tumor specimens during neurosurgery

    Science.gov (United States)

    Spinelli, Antonello Enrico; Schiariti, Marco P.; Grana, Chiara M.; Ferrari, Mahila; Cremonesi, Marta; Boschi, Federico

    2016-05-01

    We presented the first example of Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI) of human tumor specimens. A patient with a brain meningioma localized in the left parietal region was injected with 166 MBq of Y90-DOTATOC the day before neurosurgery. The specimens of the tumor removed during surgery were imaged using both CLI and RLI using an optical imager prototype developed in our laboratory. The system is based on a cooled electron multiplied charge coupled device coupled with an f/0.95 17-mm C-mount lens. We showed for the first time the possibility of obtaining CLI and RLI images of fresh human brain tumor specimens removed during neurosurgery.

  6. 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.

  7. Investigating the Scope of Resident Patient Care Handoffs within Neurosurgery

    OpenAIRE

    Babu, Maya A.; Nahed, Brian Vala; Heary, Robert F.

    2012-01-01

    Introduction: Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. Methods: A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs....

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

    OpenAIRE

    Raj Kumar Chopra; Varun Gupta; Durg Singh Chauhan

    2016-01-01

    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 analy...

  9. A systematic review of 30-day readmission after cranial neurosurgery.

    Science.gov (United States)

    Cusimano, Michael D; Pshonyak, Iryna; Lee, Michael Y; Ilie, Gabriela

    2017-08-01

    OBJECTIVE The 30-day readmission rate has emerged as an important marker of the quality of in-hospital care in several fields of medicine. This review aims to summarize available research reporting readmission rates after cranial procedures and to establish an association with demographic, clinical, and system-related factors and clinical outcomes. METHODS The authors conducted a systematic review of several databases; a manual search of the Journal of Neurosurgery, Neurosurgery, Acta Neurochirurgica, Canadian Journal of Neurological Sciences; and the cited references of the selected articles. Quality review was performed using the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) criteria. Findings are reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS A total of 1344 articles published between 1947 and 2015 were identified; 25 were considered potentially eligible, of which 12 met inclusion criteria. The 30-day readmission rates varied from 6.9% to 23.89%. Complications arising during or after neurosurgical procedures were a prime reason for readmission. Race, comorbidities, and longer hospital stay put patients at risk for readmission. CONCLUSIONS Although readmission may be an important indicator for good care for the subset of acutely declining patients, neurosurgery should aim to reduce 30-day readmission rates with improved quality of care through systemic changes in the care of neurosurgical patients that promote preventive measures.

  10. 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 

  11. The history of neurosurgery at the University of Alabama at Birmingham.

    Science.gov (United States)

    Foreman, Paul M; Markert, James M; Diethelm, Arnold G; Hadley, Mark N

    2014-10-01

    : The Division of Neurosurgery at the University of Alabama at Birmingham was formally founded in 1954 under the leadership of James Garber Galbraith. The following 60 years would see neurosurgery at the forefront of the development of a nationally recognized medical center in the heart of Birmingham, Alabama. The Department of Neurosurgery now employs 14 faculty members, performs more than 4500 neurosurgical procedures annually, is active in clinical and laboratory research, and boasts a contemporary, comprehensive residency training program.

  12. Critical safety function guidelines for experimental fusion facilities

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1989-01-01

    As fusion experiments proceed toward deuterium-tritium operation, more attention is being given to public safety. This paper presents the four classes of functions that fusion experiments must provide to assure safe, stable shutdown and retention of radionuclides. These functions are referred to as critical safety functions (CSFs). Selecting CSFs is an important step in probabilistic risk assessment (PRA). An example of CSF selection and usage for the Compact Ignition Tokamak (CIT) is also presented. 10 refs., 6 figs

  13. Critical safety function guidelines for experimental fusion facilities

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1989-01-01

    As fusion experiments proceed toward deuterium-tritium operation, more attention is being given to public safety. This paper presents the four classes of functions that fusion experiments must provide to assure safe, stable shutdown and retention of radionuclides. These functions are referred to as critical safety functions (CSFs). Selecting CSFs is an important step in probabilistic risk assessment (PRA). An example of CSF selection and usage for the Compact Ignition Tokamak (CIT) is also presented

  14. 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.

  15. 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…

  16. Experimental investigation of Lagrangian structure functions in turbulence

    DEFF Research Database (Denmark)

    Berg, Jacob; Ott, Søren; Mann, Jakob

    2009-01-01

    Lagrangian properties obtained from a particle tracking velocimetry experiment in a turbulent flow at intermediate Reynolds number are presented. Accurate sampling of particle trajectories is essential in order to obtain the Lagrangian structure functions and to measure intermittency at small...

  17. Neurosurgery for mental disorders: a review

    African Journals Online (AJOL)

    “A surgical procedure for the destruction of brain tissue for the purposes of alleviating specific ... left vagus nerve as the right vagus nerve is crucial for cardiac function. ..... D. Vagus nerve stimulation: 2-year outcomes for bipolar versus unipolar ...

  18. 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.

  19. EXPERIMENTAL AND CLINICAL SIGNIFICANCE OF RENAL FUNCTIONAL RESERVE DETERMINATION

    Directory of Open Access Journals (Sweden)

    Jernej Pajek

    2002-07-01

    Full Text Available Background. Renal functional reserve (RFR is defined as the temporary increase in glomerular filtration rate (GFR which follows the ingestion of proteins or infusion of aminoacids. This renal vasodilatatory response is probably mediated by several mechanisms, with nitric oxide being one of the most important mediators. In the last years significant progress in measuring renal functional reserve has been achieved on the basis of improvements in methods for accurate and timely appropriate GFR measurement. The method of GFR measurement using the sinistrin clearence calculation after bolus injection of sinistrin is increasingly employed.Conclusions. The article presents the latest results of experiments with RFR using this method and compares them with older reports. RFR is affected by several patophysiological processes: arterial hypertension, diabetes mellitus, deteriorating function of transplanted kidney. The results and impact of RFR determination in this conditions are described. Finally, potential for further research of RFR in atherosclerotic vascular disease is considered. Accurate determination of RFR is important for detection of early renal hemodynamic abnormalities, which can be influenced by therapeutic interventions and in this way the progression of renal functional deterioration could be prevented or at least slowed.

  20. Complications in Endovascular Neurosurgery: Critical Analysis and Classification.

    Science.gov (United States)

    Ravindra, Vijay M; Mazur, Marcus D; Park, Min S; Kilburg, Craig; Moran, Christopher J; Hardman, Rulon L; Couldwell, William T; Taussky, Philipp

    2016-11-01

    Precisely defining complications, which are used to measure overall quality, is necessary for critical review of delivery of care and quality improvement in endovascular neurosurgery, which lacks common definitions for complications. Furthermore, in endovascular interventions, events that may be labeled complications may not always negatively affect outcome. Our objective is to provide precise definitions for quality evaluation within endovascular neurosurgery. Thus, we propose an endovascular-specific classification system of complications based on our own patient series. This single-center review included all patients who had endovascular interventions from September 2013 to August 2015. Complication types were analyzed, and a descriptive analysis was undertaken to calculate the incidence of complications overall and in each category. Two hundred and seventy-five endovascular interventions were performed in 245 patients (65% female; mean age, 55 years). Forty complications occurred in 39 patients (15%), most commonly during treatment of intracranial aneurysms (24/40). Mechanical complications (eg, device deployment, catheter, or closure device failure) occurred in 8/40, technical complications (eg, failure to deploy flow diverter, unintended embolization, air emboli, retroperitoneal hemorrhage, dissection) in 11/40, judgment errors (eg, patient or equipment selection) in 9/40, and critical events (eg, groin hematoma, hemorrhagic or thromboembolic complications) in 12/40 patients. Only 12/40 complications (30%) resulted in new neurologic deficits, vessel injury requiring surgery, or blood transfusion. We propose an endovascular-specific classification system of complications with 4 categories: mechanical, technical, judgment errors, and critical events. This system provides a framework for future studies and quality control in endovascular neurosurgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. 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.

  2. A neurosurgery/stereotactic radiotherapy dedicated PACS for conformal radiotherapy

    International Nuclear Information System (INIS)

    Lefkopoulos, D.; Bocquiault, P.; Levrier, M.; Merienne, L.; Schlienger, M.

    1995-01-01

    To realise conformal cerebral stereotactic irradiations we use a Neurosurgery/stereotactic dedicated PACS between two distant hospitals. It connects the stereotactic neurosurgery planification imaging system NEUROAXIS (Sopelem-Sofretec/Ste Anne Hospital) with the dosimetric TPS ARTEMIS-3D/Dosigray (Tenon Hospital). NEUROAXIS is a computer aided stereotactic biopsies and stereo-electroencephalographies, used by surgeons in operating room. The system determines the precise location data for Talairach radiological equipment (X ray source at 5 meters from film) and the geometry of scanner and MRI stereotactical referentials. It provides a full set of features for lesion localization, geometrical computations, surgical planifications, picture archiving, stereotactic angiography, CT and MRI image processing and networking. It sends images through the French public digital network ISDN (NUMERIS/France Telecom : 2x64 Kbits/s) from Ste Anne to Tenon Hospital. Stereotactic angiographic and CT images are reformatted into the DOSIGRAY image processing environment where 3-D dose distributions, displays and DVHs are computed to determine the optimal treatment. ARTEMIS-3D/Dosigray is a TPS for stereotactic radiotherapy devised by the Tenon Hospital for clinical methodology and 3D dose calculations, optimization software development and the Dosigray company for multimodality imaging, (2D(3D)) computer graphics for dose and anatomical representation and data networking. Communication within the radiation oncology department is provided by local area ETHERNET network, linking heterogeneous systems (Vaxstations-3200; Decstation (5000(240))) by means of different protocols. The works in progress are to send back via the same network the 3-D dose matrix to Neurosurgery department NEUROAXIS system. Our PACS is used since six months to treat patients. It has permitted to improve the treatment quality in comparison with our first version TPS ARTEMIS-3D

  3. Checklists in Neurosurgery to Decrease Preventable Medical Errors: A Review

    Science.gov (United States)

    Enchev, Yavor

    2015-01-01

    Neurosurgery represents a zero tolerance environment for medical errors, especially preventable ones like all types of wrong site surgery, complications due to the incorrect positioning of patients for neurosurgical interventions and complications due to failure of the devices required for the specific procedure. Following the excellent and encouraging results of the safety checklists in intensive care medicine and in other surgical areas, the checklist was naturally introduced in neurosurgery. To date, the reported world experience with neurosurgical checklists is limited to 15 series with fewer than 20,000 cases in various neurosurgical areas. The purpose of this review was to study the reported neurosurgical checklists according to the following parameters: year of publication; country of origin; area of neurosurgery; type of neurosurgical procedure-elective or emergency; person in charge of the checklist completion; participants involved in completion; whether they prevented incorrect site surgery; whether they prevented complications due to incorrect positioning of the patients for neurosurgical interventions; whether they prevented complications due to failure of the devices required for the specific procedure; their specific aims; educational preparation and training; the time needed for checklist completion; study duration and phases; number of cases included; barriers to implementation; efforts to implementation; team appreciation; and safety outcomes. Based on this analysis, it could be concluded that neurosurgical checklists represent an efficient, reliable, cost-effective and time-saving tool for increasing patient safety and elevating the neurosurgeons’ self-confidence. Every neurosurgical department must develop its own neurosurgical checklist or adopt and modify an existing one according to its specific features and needs in an attempt to establish or develop its safety culture. The world, continental, regional and national neurosurgical societies

  4. Neurosurgery Elective for Preclinical Medical Students: Early Exposure and Changing Attitudes.

    Science.gov (United States)

    Zuckerman, Scott L; Mistry, Akshitkumar M; Hanif, Rimal; Chambless, Lola B; Neimat, Joseph S; Wellons, John C; Mocco, J; Sills, Allen K; McGirt, Matthew J; Thompson, Reid C

    2016-02-01

    Exposure to surgical subspecialties is limited during the preclinical years of medical school. To offset this limitation, the authors created a neurosurgery elective for first- and second-year medical students. The objective was to provide each student with early exposure to neurosurgery by combining clinical experience with faculty discussions about the academic and personal realities of a career in neurosurgery. From 2012 to 2013, the authors offered a neurosurgery elective course to first- and second-year medical students. Each class consisted of the following: 1) peer-reviewed article analysis; 2) student presentation; 3) faculty academic lecture; 4) faculty personal lecture with question and answer period. Thirty-five students were enrolled over a 2-year period. After completing the elective, students were more likely to: consider neurosurgery as a future career (P life to be higher (P life, and family-work balance, while not altering the students' views about the difficulty of training. Adopting a neurosurgery elective geared towards preclinical medical students can significantly change attitudes about the field of neurosurgery and has potential to increase interest in pursuing a career in neurosurgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. History, Current Situation, and Future Development of Endoscopic Neurosurgery in China.

    Science.gov (United States)

    Li, Chuzhong; Zhu, Haibo; Zong, Xuyi; Wang, Xinsheng; Gui, Songbai; Zhao, Peng; Zhang, Yazhuo

    2018-02-01

    During the past few decades, Chinese endoscopic neurosurgery has rapidly developed in synchrony with the rest of the world. The aim of this article is to review the development of Chinese endoscopic neurosurgery, including its birth, growth, current situation, and prospects. The history of Chinese endoscopic neurosurgery development can be divided into 3 stages: cognition and initial stage (1964-1995), exploration and maturity stage (1995-2006), and rapid development and promotion stage (2006-present). In the first stage, we mainly began to become aware of endoscopic neurosurgery from the translation and review of literature. In the mid to late 1990s, Chinese neurosurgery pioneers began using neuroendoscopic techniques. In the following decade, many leading neurosurgeons made persistent efforts to push the development of Chinese endoscopic neurosurgery forward, focusing on advocating for and promoting and popularizing neuroendoscopic technology. In the rapid development and promotion stage, many representative national and regional neurosurgical centers became skilled and efficient in the application of neuroendoscopic technology and became new advocates of the technology. The number of cases, level of technology, and treatment effectiveness are gradually nearing international standards. However, future development requires promotion of balanced development to decrease regional disparities, further strengthen international exchanges, follow the latest developments, and constantly innovate for continuous improvement. Following the dramatic efforts of several pioneers, development of Chinese endoscopic neurosurgery has been considerable, and it has become an important component of neurosurgery worldwide. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Third-generation cephalosporins as antibiotic prophylaxis in neurosurgery : What's the evidence?

    NARCIS (Netherlands)

    Liu, Weiming; Neidert, Marian Christoph; Groen, Rob J. M.; Woernle, Christoph Michael; Grundmann, Hajo

    To analyze the role of third-generation cephalosporins as prophylactic antibiotics in neurosurgery. We reviewed the literature for data from randomized controlled trials (RCTs) on third-generation cephalosporins compared to other antibiotic regimen in neurosurgery. End point of the RCTs was the

  7. A frameless stereotaxic operating microscope for neurosurgery

    International Nuclear Information System (INIS)

    Friets, E.M.; Strohbehn, J.W.; Hatch, J.F.; Roberts, D.W.

    1989-01-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given

  8. A frameless stereotaxic operating microscope for neurosurgery.

    Science.gov (United States)

    Friets, E M; Strohbehn, J W; Hatch, J F; Roberts, D W

    1989-06-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given.

  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. Publication misrepresentation among neurosurgery residency applicants: an increasing problem.

    Science.gov (United States)

    Kistka, Heather M; Nayeri, Arash; Wang, Li; Dow, Jamie; Chandrasekhar, Rameela; Chambless, Lola B

    2016-01-01

    OBJECT Misrepresentation of scholarly achievements is a recognized phenomenon, well documented in numerous fields, yet the accuracy of reporting remains dependent on the honor principle. Therefore, honest self-reporting is of paramount importance to maintain scientific integrity in neurosurgery. The authors had observed a trend toward increasing numbers of publications among applicants for neurosurgery residency at Vanderbilt University and undertook this study to determine whether this change was a result of increased academic productivity, inflated reporting, or both. They also aimed to identify application variables associated with inaccurate citations. METHODS The authors retrospectively reviewed the residency applications submitted to their neurosurgery department in 2006 (n = 148) and 2012 (n = 194). The applications from 2006 were made via SF Match and those from 2012 were made using the Electronic Residency Application Service. Publications reported as "accepted" or "in press" were verified via online search of Google Scholar, PubMed, journal websites, and direct journal contact. Works were considered misrepresented if they did not exist, incorrectly listed the applicant as first author, or were incorrectly listed as peer reviewed or published in a printed journal rather than an online only or non-peer-reviewed publication. Demographic data were collected, including applicant sex, medical school ranking and country, advanced degrees, Alpha Omega Alpha membership, and USMLE Step 1 score. Zero-inflated negative binomial regression was used to identify predictors of misrepresentation. RESULTS Using univariate analysis, between 2006 and 2012 the percentage of applicants reporting published works increased significantly (47% vs 97%, p < 0.001). However, the percentage of applicants with misrepresentations (33% vs 45%) also increased. In 2012, applicants with a greater total of reported works (p < 0.001) and applicants from unranked US medical schools (those not

  11. Dr. Lenke Horvath (1917-1991): Creator of Pediatric Neurosurgery in Romania.

    Science.gov (United States)

    Mohan, Dumitru; Moisa, Horatiu Alexandru; Nica, Dan Aurel; Ciurea, Alexandru Vlad

    2016-04-01

    The development of neurosurgery as an independent specialty took place with great difficulty in Romania. In this respect, the most revered personalities are those of Professor Alexandru Moruzzi (1900-1957) (in Iasi) and Professor Dimitrie Bagdasar (1893-1946) (in Bucharest), who are the fathers of modern neurosurgery in Romania. Professor Bagdasar was schooled in Professor Harvey Cushing's clinic in Boston and is credited with creating the first completely independent neurosurgical unit in Romania. His legacy was carried on with honor by Professor Constantin Arseni (1912-1994), who, in 1975, tasked Dr. Lenke Horvath (1917-1991) with creating the first autonomous pediatric neurosurgery unit in Bucharest. This article is a small tribute to the founder of pediatric neurosurgery in Romania and one of the female pioneer neurosurgeons, who, by personal example of dedication and hard work, radically changed medical thinking and neurosurgery in Romania. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Experimental strategies to promote functional recovery after peripheral nerve injuries.

    Science.gov (United States)

    Gordon, Tessa; Sulaiman, Olawale; Boyd, J Gordon

    2003-12-01

    The capacity of Schwann cells (SCs) in the peripheral nervous system to support axonal regeneration, in contrast to the oligodendrocytes in the central nervous system, has led to the misconception that peripheral nerve regeneration always restores function. Here, we consider how prolonged periods of time that injured neurons remain without targets during axonal regeneration (chronic axotomy) and that SCs in the distal nerve stumps remain chronically denervated (chronic denervation) progressively reduce the number of motoneurons that regenerate their axons. We demonstrate the effectiveness of low-dose, brain-derived neurotrophic and glial-derived neurotrophic factors to counteract the effects of chronic axotomy in promoting axonal regeneration. High-dose brain-derived neurotrophic factor (BDNF) on the other hand, acting through the p75 receptor, inhibits axonal regeneration and may be a factor in stopping regenerating axons from forming neuromuscular connections in skeletal muscle. The immunophilin, FK506, is also effective in promoting axonal regeneration after chronic axotomy. Chronic denervation of SCs (>1 month) severely deters axonal regeneration, although the few motor axons that do regenerate to reinnervate muscles become myelinated and form enlarged motor units in the reinnervated muscles. We found that in vitro incubation of chronically denervated SCs with transforming growth factor-beta re-established their growth-supportive phenotype in vivo, consistent with the idea that the interaction between invading macrophages and denervated SCs during Wallerian degeneration is essential to sustain axonal regeneration by promoting the growth-supportive SC phenotype. Finally, we consider the effectiveness of a brief period of 20 Hz electrical stimulation in promoting the regeneration of axons across the surgical gap after nerve repair.

  13. 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.

  14. Informed consent in neurosurgery--translating ethical theory into action.

    Science.gov (United States)

    Schmitz, Dagmar; Reinacher, Peter C

    2006-09-01

    Although a main principle of medical ethics and law since the 1970s, standards of informed consent are regarded with great scepticism by many clinicans. By reviewing the reactions to and adoption of this principle of medical ethics in neurosurgery, the characteristic conflicts that emerge between theory and everyday clinical experience are emphasised and a modified conception of informed consent is proposed. The adoption and debate of informed consent in neurosurgery took place in two steps. Firstly, respect for patient autonomy was included into the ethical codes of the professional organisations. Secondly, the legal demands of the principle were questioned by clinicians. Informed consent is mainly interpreted in terms of freedom from interference and absolute autonomy. It lacks a constructive notion of physician-patient interaction in its effort to promote the best interest of the patient, which, however, potentially emerges from a reconsideration of the principle of beneficence. To avoid insufficient legal interpretations, informed consent should be understood in terms of autonomy and beneficence. A continuous interaction between the patient and the given physician is considered as an essential prerequisite for the realisation of the standards of informed consent.

  15. Interrupted time-series analysis: studying trends in neurosurgery.

    Science.gov (United States)

    Wong, Ricky H; Smieliauskas, Fabrice; Pan, I-Wen; Lam, Sandi K

    2015-12-01

    OBJECT Neurosurgery studies traditionally have evaluated the effects of interventions on health care outcomes by studying overall changes in measured outcomes over time. Yet, this type of linear analysis is limited due to lack of consideration of the trend's effects both pre- and postintervention and the potential for confounding influences. The aim of this study was to illustrate interrupted time-series analysis (ITSA) as applied to an example in the neurosurgical literature and highlight ITSA's potential for future applications. METHODS The methods used in previous neurosurgical studies were analyzed and then compared with the methodology of ITSA. RESULTS The ITSA method was identified in the neurosurgical literature as an important technique for isolating the effect of an intervention (such as a policy change or a quality and safety initiative) on a health outcome independent of other factors driving trends in the outcome. The authors determined that ITSA allows for analysis of the intervention's immediate impact on outcome level and on subsequent trends and enables a more careful measure of the causal effects of interventions on health care outcomes. CONCLUSIONS ITSA represents a significant improvement over traditional observational study designs in quantifying the impact of an intervention. ITSA is a useful statistical procedure to understand, consider, and implement as the field of neurosurgery evolves in sophistication in big-data analytics, economics, and health services research.

  16. Defining Innovation in Neurosurgery: Results from an International Survey.

    Science.gov (United States)

    Zaki, Mark M; Cote, David J; Muskens, Ivo S; Smith, Timothy R; Broekman, Marike L

    2018-06-01

    Innovation is a part of the daily practice of neurosurgery. However, a clear definition of what constitutes innovation is lacking and opinions vary from continent to continent, from hospital to hospital, and from surgeon to surgeon. In this study, we distributed an online survey to neurosurgeons from multiple countries to investigate what neurosurgeons consider innovative, by gathering opinions on several hypothetical cases. The anonymous survey consisted of 52 questions and took approximately 10 minutes to complete. A total of 355 neurosurgeons across all continents excluding Antarctica completed the survey. Neurosurgeons achieved consensus (>75%) in considering specific cases to be innovative, including laser resection of meningioma, focused ultrasonography for tumor, oncolytic virus, deep brain stimulation for addiction, and photodynamic therapy for tumor. Although the new dura substitute case was not considered innovative, there was consensus among neurosurgeons indicating that institutional review board approval was still necessary to maintain ethical standards. Furthermore, although 90% of neurosurgeons considered an oncolytic virus for glioblastoma multiforme to be innovative, only 78% believed that institutional review board approval was necessary before treatment. Our results indicate that innovation is a heterogeneous concept among neurosurgeons that necessitates standardization to ensure appropriate patient safety without stifling progress. We discuss both the ethical drawbacks of not having a clear definition of innovation and the challenges in achieving a unified understanding of innovation in neurosurgery and offer suggestions for uniting the field. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. 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

    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.

  18. 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.

  19. Lymphatic vessel density and function in experimental bladder cancer

    International Nuclear Information System (INIS)

    Saban, Marcia R; Wu, Xue-Ru; Saban, Ricardo; Towner, Rheal; Smith, Nataliya; Abbott, Andrew; Neeman, Michal; Davis, Carole A; Simpson, Cindy; Maier, Julie; Mémet, Sylvie

    2007-01-01

    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. 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. 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 flow within the tumoral area. In addition, NIRF

  20. Biases in the experimental annotations of protein function and their effect on our understanding of protein function space.

    Directory of Open Access Journals (Sweden)

    Alexandra M Schnoes

    Full Text Available The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here, we investigate just how prevalent is the "few articles - many proteins" phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments.

  1. Biases in the Experimental Annotations of Protein Function and Their Effect on Our Understanding of Protein Function Space

    Science.gov (United States)

    Schnoes, Alexandra M.; Ream, David C.; Thorman, Alexander W.; Babbitt, Patricia C.; Friedberg, Iddo

    2013-01-01

    The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here, we investigate just how prevalent is the “few articles - many proteins” phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments. PMID:23737737

  2. Functional aspects of developmental toxicity of polyhalogenated aromatic hydrocarbons in experimental animals and human infants

    NARCIS (Netherlands)

    Brouwer, A.; Ahlborg, U. G.; van den Berg, M.; Birnbaum, L. S.; Boersma, E. R.; Bosveld, B.; Denison, M. S.; Gray, L. E.; Hagmar, L.; Holene, E.

    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

  3. Pain and executive functions: A unique relationship between Stroop task and experimentally induced pain

    NARCIS (Netherlands)

    Bjekic, J.; Zivanovic, M.; Puric, D.; Oosterman, J.M.; Filipovic, S.R.

    2018-01-01

    There is a growing body of evidence that a higher level of cognitive inhibition is associated with lower experimental pain sensitivity. However, a systematic examination of the association between executive functions, which include not only inhibition but also updating and shifting, and experimental

  4. 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....

  5. 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...

  6. Intraoperative magnetic resonance imaging for neurosurgery – An anaesthesiologist's challenge

    Directory of Open Access Journals (Sweden)

    Rajashree U Gandhe

    2018-01-01

    Full Text Available Intraoperative magnetic resonance imaging (MRI-guided neurosurgery has gained popularity over the years globally. These surgeries require a dedicated operating room and MRI-compatible anaesthesia equipment. The anaesthesiologist providing care in this setup needs to be experienced and vigilant to ensure patient safety. Strict adherence to MRI safety checklists and regular personnel training would avoid potential accidents and life-threatening emergencies. Teamwork, good communication, preprocedure planning, and familiarity with the surroundings are very important for safe care and good outcomes. We performed a literature search in Google Scholar, PubMed and Cochrane databases for original and reviewed articles for the origins, development and applications of intraoperative MRI in neurosurgical procedures. Much of the research has emphasised on the surgical indications than the anaesthetic challenges faced during intraoperative MRI guided surgery. The purpose of this review is to discuss the anaesthetic concerns specific to this unique environment.

  7. 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.

  8. The incidentaloma of the pituitary gland: Is neurosurgery required

    Energy Technology Data Exchange (ETDEWEB)

    Reincke, M.; Allolio, B.; Saeger, W.; Menzel, J.; Winkelmann, W. (Univ. of Cologne (West Germany))

    1990-05-23

    The authors describe a series of 18 patients with an intrasellar mass incidentally discovered by computed tomography or magnetic resonance imaging. The average size of the mass was 13 mm, with a range from 5 to 25 mm. Initial ophthalmologic examination revealed bitemporal hemianopia in 2 patients. Results of routine endocrine testing showed partial hypopituitarism in 5 patients and growth hormone hypersecretion without signs and symptoms of acromegaly in 1 patient. Four patients underwent neurosurgery. Histologically, one chondroid chordoma and three pituitary adenomas were found. In the remaining 14 patients treated conservatively, repeated computed tomography and magnetic resonance imaging revealed no significant change in tumor size at the time of follow-up. The results suggest that the incidentaloma of the pituitary gland is a benign condition that does not necessarily require neurosurgical intervention.

  9. The incidentaloma of the pituitary gland: Is neurosurgery required?

    International Nuclear Information System (INIS)

    Reincke, M.; Allolio, B.; Saeger, W.; Menzel, J.; Winkelmann, W.

    1990-01-01

    The authors describe a series of 18 patients with an intrasellar mass incidentally discovered by computed tomography or magnetic resonance imaging. The average size of the mass was 13 mm, with a range from 5 to 25 mm. Initial ophthalmologic examination revealed bitemporal hemianopia in 2 patients. Results of routine endocrine testing showed partial hypopituitarism in 5 patients and growth hormone hypersecretion without signs and symptoms of acromegaly in 1 patient. Four patients underwent neurosurgery. Histologically, one chondroid chordoma and three pituitary adenomas were found. In the remaining 14 patients treated conservatively, repeated computed tomography and magnetic resonance imaging revealed no significant change in tumor size at the time of follow-up. The results suggest that the incidentaloma of the pituitary gland is a benign condition that does not necessarily require neurosurgical intervention

  10. Review of 3-Dimensional Printing on Cranial Neurosurgery Simulation Training.

    Science.gov (United States)

    Vakharia, Vejay N; Vakharia, Nilesh N; Hill, Ciaran S

    2016-04-01

    Shorter working times, reduced operative exposure to complex procedures, and increased subspecialization have resulted in training constraints within most surgical fields. Simulation has been suggested as a possible means of acquiring new surgical skills without exposing patients to the surgeon's operative "learning curve." Here we review the potential impact of 3-dimensional printing on simulation and training within cranial neurosurgery and its implications for the future. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a comprehensive search of PubMed, OVID MEDLINE, Embase, and the Cochrane Database of Systematic Reviews was performed. In total, 31 studies relating to the use of 3-dimensional (3D) printing within neurosurgery, of which 16 were specifically related to simulation and training, were identified. The main impact of 3D printing on neurosurgical simulation training was within vascular surgery, where patient-specific replication of vascular anatomy and pathologies can aid surgeons in operative planning and clip placement for reconstruction of vascular anatomy. Models containing replicas of brain tumors have also been reconstructed and used for training purposes, with some providing realistic representations of skin, subcutaneous tissue, bone, dura, normal brain, and tumor tissue. 3D printing provides a unique means of directly replicating patient-specific pathologies. It can identify anatomic variation and provide a medium in which training models can be generated rapidly, allowing the trainee and experienced neurosurgeon to practice parts of operations preoperatively. Future studies are required to validate this technology in comparison with current simulators and show improved patient outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Patients' views on priority setting in neurosurgery: A qualitative study.

    Science.gov (United States)

    Gunaratnam, Caroline; Bernstein, Mark

    2016-01-01

    Accountability for Reasonableness is an ethical framework which has been implemented in various health care systems to improve and evaluate the fairness of priority setting. This framework is grounded on four mandatory conditions: relevance, publicity, appeals, and enforcement. There have been few studies which have evaluated the patient stakeholders' acceptance of this framework; certainly no studies have been done on patients' views on the prioritization system for allocating patients for operating time in a system with pressure on the resource of inpatient beds. The aim of this study is to examine neurosurgical patients' views on the prioritization of patients for operating theater (OT) time on a daily basis at a tertiary and quaternary referral neurosurgery center. Semi-structured face-to-face interviews were conducted with thirty-seven patients, recruited from the neurosurgery clinic at Toronto Western Hospital. Family members and friends who accompanied the patient to their clinic visit were encouraged to contribute to the discussion. Interviews were audio recorded, transcribed verbatim, and subjected to thematic analysis using open and axial coding. Overall, patients are supportive of the concept of a priority-setting system based on fairness, but felt that a few changes would help to improve the fairness of the current system. These changes include lowering the level of priority given to volume-funded cases and providing scheduled surgeries that were previously canceled a higher level of prioritization. Good communication, early notification, and rescheduling canceled surgeries as soon as possible were important factors that directly reflected the patients' confidence level in their doctor, the hospital, and the health care system. This study is the first clinical qualitative study of patients' perspective on a prioritization system used for allocating neurosurgical patients for OT time on a daily basis in a socialized not-for-profit health care system with

  12. In vivo porcine training model for cranial neurosurgery.

    Science.gov (United States)

    Regelsberger, Jan; Eicker, Sven; Siasios, Ioannis; Hänggi, Daniel; Kirsch, Matthias; Horn, Peter; Winkler, Peter; Signoretti, Stefano; Fountas, Kostas; Dufour, Henry; Barcia, Juan A; Sakowitz, Oliver; Westermaier, Thomas; Sabel, Michael; Heese, Oliver

    2015-01-01

    Supplemental education is desirable for neurosurgical training, and the use of human cadaver specimen and virtual reality models is routine. An in vivo porcine training model for cranial neurosurgery was introduced in 2005, and our recent experience with this unique model is outlined here. For the first time, porcine anatomy is illustrated with particular respect to neurosurgical procedures. The pros and cons of this model are described. The aim of the course was to set up a laboratory scenery imitating an almost realistic operating room in which anatomy of the brain and neurosurgical techniques in a mentored environment free from time constraints could be trained. Learning objectives of the course were to learn about the microsurgical techniques in cranial neurosurgery and the management of complications. Participants were asked to evaluate the quality and utility of the programme via standardized questionnaires by a grading scale from A (best) to E (worst). In total, 154 residents have been trained on the porcine model to date. None of the participants regarded his own residency programme as structured. The bleeding and complication management (97%), the realistic laboratory set-up (89%) and the working environment (94%) were favoured by the vast majority of trainees and confirmed our previous findings. After finishing the course, the participants graded that their skills in bone drilling, dissecting the brain and preserving cerebral vessels under microscopic magnification had improved to level A and B. In vivo hands-on courses, fully equipped with microsurgical instruments, offer an outstanding training opportunity in which bleeding management on a pulsating, vital brain represents a unique training approach. Our results have shown that education programmes still lack practical training facilities in which in vivo models may act as a complementary approach in surgical training.

  13. Operative volume and outcomes of cerebrovascular neurosurgery in children.

    Science.gov (United States)

    Bekelis, Kimon; Connolly, Ian D; Do, Huy M; Choudhri, Omar

    2016-11-01

    OBJECTIVE The impact of procedural volume on the outcomes of cerebrovascular surgery in children has not been determined. In this study, the authors investigated the association of operative volume on the outcomes of cerebrovascular neurosurgery in pediatric patients. METHODS The authors performed a cohort study of all pediatric patients who underwent a cerebrovascular procedure between 2003 and 2012 and were registered in the Kids' Inpatient Database (KID). To control for confounding, the authors used multivariable regression models, propensity-score conditioning, and mixed-effects analysis to account for clustering at the hospital level. RESULTS During the study period, 1875 pediatric patients in the KID underwent cerebrovascular neurosurgery and met the inclusion criteria for the study; 204 patients (10.9%) underwent aneurysm clipping, 446 (23.8%) underwent coil insertion for an aneurysm, 827 (44.1%) underwent craniotomy for arteriovenous malformation resection, and 398 (21.2%) underwent bypass surgery for moyamoya disease. Mixed-effects multivariable regression analysis revealed that higher procedural volume was associated with fewer inpatient deaths (OR 0.58; 95% CI 0.40-0.85), a lower rate of discharges to a facility (OR 0.87; 95% CI 0.82-0.92), and shorter length of stay (adjusted difference -0.22; 95% CI -0.32 to -0.12). The results in propensity-adjusted multivariable models were robust. CONCLUSIONS In a national all-payer cohort of pediatric patients who underwent a cerebrovascular procedure, the authors found that higher procedural volume was associated with fewer deaths, a lower rate of discharges to a facility, and decreased lengths of stay. Regionalization initiatives should include directing children with such rare pathologies to a center of excellence.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Free-access open-source e-learning in comprehensive neurosurgery skills training

    OpenAIRE

    Payal Jotwani; Vinkle Srivastav; Manjul Tripathi; Rama Chandra Deo; Britty Baby; Natesan Damodaran; Ramandeep Singh; Ashish Suri; Martin Bettag; Tara Sankar Roy; Christoph Busert; Marcus Mehlitz; Sanjeev Lalwani; Kanwaljeet Garg; Kolin Paul

    2014-01-01

    Background: Since the end of last century, technology has taken a front seat in dispersion of medical education. Advancements of technology in neurosurgery and traditional training methods are now being challenged by legal and ethical concerns of patient safety, resident work-hour restriction and cost of operating-room time. To supplement the existing neurosurgery education pattern, various e-learning platforms are introduced as structured, interactive learning system. Materials and Methods: ...

  19. 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.

  20. Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations

    International Nuclear Information System (INIS)

    Streek, Jacco van de; Neumann, Marcus A.

    2010-01-01

    The accuracy of a dispersion-corrected density functional theory method is validated against 241 experimental organic crystal structures from Acta Cryst. Section E. This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 Å either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect

  1. [Brain metastasis from breast cancer: who?, when? and special considerations about the role of technology in neurosurgery].

    Science.gov (United States)

    Dutertre, Guillaume; Pouit, Bruno

    2011-04-01

    Questions about both the place and the role of surgery on brain metastasis from breast cancer are arising more and more frequently in practice due to the increase of brain metastasis in patients suffering from a form of cancer recognized as one of the most recurrent cancers in adults but also one of the most sensitive to general treatments of the systemic disease. With improvements in anaesthesia, in surgical instruments, and in global care, neurosurgery has taken advantage of new techniques such as pre- and even per-operative imagery and also neuronavigation. These techniques enable radical and effective surgical intervention with a high level of safety for the patient, making neurosurgery perfectly competitive with other therapeutic modalities, particularly on functional grounds. As for symptomatic treatments or other anti-metastasis treatments, most situations allow a reflection on the global therapeutic strategy which can be adapted to individual cases depending on the patient's general prognosis. In developing this global therapeutic strategy, surgical treatment is still as relevant as ever.

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

    DEFF Research Database (Denmark)

    Jorgensen, 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...... and serum cortisol did not increase at all in any of the groups. As a measure of parasympathetic neural activity, independent of sympathetic neural activity, the beat-to-beat variation of the heart rate was calculated. The functional patients had a significantly higher beat-to-beat variation expressed...... 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...

  3. Functional magnetic resonances imaging of psychological functions with experimentally induced emotion

    International Nuclear Information System (INIS)

    Grodd, W.; Schneider, F.; Klose, U.; Naegele, T.

    1995-01-01

    In this study a T 2 * FLASH sequence (TR 240 ms, TE 60 ms, slice thickness 4 mm, α=40 , matrix 64x128) was used to investigate changes in signal intensity within the temporal lobe and the amygdala during experimentally induced emotions. Visual stimuli of happy [sad] facial portraits were presented to volunteers to induce changes in the subjects' mood while lying in the tomograph. In agreement with a previous PET study, a significant increase in signal intensity in the left amygdala was found during induction of a sad mood, while no comparable effect was visible during induction of a happy mood. (orig.) [de

  4. 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...

  5. Unplanned readmission within 90 days after pediatric neurosurgery.

    Science.gov (United States)

    Chotai, Silky; Guidry, Bradley S; Chan, Emily W; Sborov, Katherine D; Gannon, Stephen; Shannon, Chevis; Bonfield, Christopher M; Wellons, John C; Naftel, Robert P

    2017-12-01

    OBJECTIVE Readmission and return to operating room after surgery are increasingly being used as a proxy for quality of care. Nearly 60% of these readmissions are unplanned, which translates into billions of dollars in health care costs. The authors set out to analyze the incidence of readmission at their center, to define causes of unplanned readmission, and to determine the preoperative and surgical variables associated with readmissions following pediatric neurosurgery. METHODS A total of 536 children who underwent operations for neurosurgical diagnoses between 2012 and 2015 and who were later readmitted were included in the final analysis. Unplanned readmissions were defined to have occurred as a result of complications within 90 days after index surgery. Patient records were retrospectively reviewed to determine the primary diagnosis, surgery indication, and cause of readmission and return to operating room. The cost for index hospitalization, readmission episode, and total cost were derived based on the charges obtained from administrative data. Bivariate and multivariable analyses were conducted. RESULTS Of 536 patients readmitted in total, 17.9% (n = 96) were readmitted within 90 days. Of the overall readmissions, 11.9% (n = 64) were readmitted within 30 days, and 5.97% (n = 32) were readmitted between 31 and 90 days. The median duration between discharge and readmission was 20 days (first quartile [Q1]: 9 days, third quartile [Q3]: 36 days). The most common reason for readmission was shunt related (8.2%, n = 44), followed by wound infection (4.7%, n = 25). In the risk-adjusted multivariable logistic regression model for total 90-day readmission, patients with the following characteristics: younger age (p = 0.001, OR 0.886, 95% CI 0.824-0.952); "other" (nonwhite, nonblack) race (p = 0.024, OR 5.49, 95% CI 1.246-24.2); and those born preterm (p = 0.032, OR 2.1, 95% CI 1.1-4.12) had higher odds of being readmitted within 90 days after discharge. The total

  6. Thermal model to investigate the temperature in bone grinding for skull base neurosurgery.

    Science.gov (United States)

    Zhang, Lihui; Tai, Bruce L; Wang, Guangjun; Zhang, Kuibang; Sullivan, Stephen; Shih, Albert J

    2013-10-01

    This study develops a thermal model utilizing the inverse heat transfer method (IHTM) to investigate the bone grinding temperature created by a spherical diamond tool used for skull base neurosurgery. Bone grinding is a critical procedure in the expanded endonasal approach to remove the cranial bone and access to the skull base tumor via nasal corridor. The heat is generated during grinding and could damage the nerve or coagulate the blood in the carotid artery adjacent to the bone. The finite element analysis is adopted to investigate the grinding-induced bone temperature rise. The heat source distribution is defined by the thermal model, and the temperature distribution is solved using the IHTM with experimental inputs. Grinding experiments were conducted on a bovine cortical bone with embedded thermocouples. Results show significant temperature rise in bone grinding. Using 50°C as the threshold, the thermal injury can propagate about 3mm in the traverse direction, and 3mm below the ground surface under the dry grinding condition. The presented methodology demonstrated the capability of being a thermal analysis tool for bone grinding study. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  7. 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.

  8. Reoperations within 48 hours following 7942 pediatric neurosurgery procedures.

    Science.gov (United States)

    Roy, Anil K; Chu, Jason; Bozeman, Caroline; Sarda, Samir; Sawvel, Michael; Chern, Joshua J

    2017-06-01

    OBJECTIVE Various indicators are used to evaluate the quality of care delivered by surgical services, one of which is early reoperation rate. The indications and rate of reoperations within a 48-hour time period have not been previously reported for pediatric neurosurgery. METHODS Between May 1, 2009, and December 30, 2014, 7942 surgeries were performed by the pediatric neurosurgery service in the operating rooms at a single institution. Demographic, socioeconomic, and clinical characteristics associated with each of the operations were prospectively collected. The procedures were grouped into 31 categories based on the nature of the procedure and underlying diseases. Reoperations within 48 hours at the conclusion of the index surgery were reviewed to determine whether the reoperation was planned or unplanned. Multivariate logistic regression was employed to analyze risk factors associated with unplanned reoperations. RESULTS Cerebrospinal fluid shunt-and hydrocephalus-related surgeries accounted for 3245 (40.8%) of the 7942 procedures. Spinal procedures, craniotomy for tumor resections, craniotomy for traumatic injury, and craniofacial reconstructions accounted for an additional 8.7%, 6.8%, 4.5%, and 4.5% of surgical volume. There were 221 reoperations within 48 hours of the index surgery, yielding an overall incidence of 2.78%; 159 of the reoperation were unplanned. Of these 159 unplanned reoperations, 121 followed index operations involving shunt manipulations. Using unplanned reoperations as the dependent variable (n = 159), index operations with a starting time after 3 pm and admission through the emergency department (ED) were associated with a two- to threefold increase in the likelihood of reoperations (after-hour surgery, odds ratio [OR] 2.01 [95% CI 1.43-2.83, p < 0.001]; ED admission, OR 1.97 (95% CI 1.32-2.96, p < 0.05]). CONCLUSIONS Approximately 25% of the reoperations within 48 hours of a pediatric neurosurgical procedure were planned. When

  9. Experimental Characterization of the Energy Absorption of Functionally Graded Foam Filled Tubes Under Axial Crushing Loads

    Science.gov (United States)

    Ebrahimi, Saeed; Vahdatazad, Nader; Liaghat, Gholamhossein

    2018-03-01

    This paper deals with the energy absorption characterization of functionally graded foam (FGF) filled tubes under axial crushing loads by experimental method. The FGF tubes are filled axially by gradient layers of polyurethane foams with different densities. The mechanical properties of the polyurethane foams are firstly obtained from axial compressive tests. Then, the quasi-static compressive tests are carried out for empty tubes, uniform foam filled tubes and FGF filled tubes. Before to present the experimental test results, a nonlinear FEM simulation of the FGF filled tube is carried out in ABAQUS software to gain more insight into the crush deformation patterns, as well as the energy absorption capability of the FGF filled tube. A good agreement between the experimental and simulation results is observed. Finally, the results of experimental test show that an FGF filled tube has excellent energy absorption capacity compared to the ordinary uniform foam-filled tube with the same weight.

  10. 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, $R_A< R_D$.

  11. 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

    The determination of conformational preferences in unfolded and disordered proteins is an important challenge in structural biology. We here describe an algorithm to optimize energy functions for the simulation of unfolded proteins. The procedure is based on the maximum likelihood principle and e...... and can be applied to a range of experimental data and energy functions including the force fields used in molecular dynamics simulations.......The determination of conformational preferences in unfolded and disordered proteins is an important challenge in structural biology. We here describe an algorithm to optimize energy functions for the simulation of unfolded proteins. The procedure is based on the maximum likelihood principle...

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

    Science.gov (United States)

    Konakondla, Sanjay; Fong, Reginald; Schirmer, Clemens M

    2017-01-01

    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. PMID:28765716

  13. Strategic design for pediatric neurosurgery missions across the Western Hemisphere.

    Science.gov (United States)

    Hambrecht, Amanda; Duenas, Matthew J; Hahn, Edward J; Aryan, Henry E; Hughes, Samuel A; Waters, Dawn; Levy, Michael L; Jandial, Rahul

    2013-01-01

    With growing interest in global health, surgeons have created outreach missions to improve health care disparities in less developed countries. These efforts are mainly episodic with visiting surgeons performing the operations and minimal investment in local surgeon education. To create real and durable advancement in surgical services in disciplines that require urgent patient care, such as pediatric neurosurgery, improving the surgical armamentarium of the local surgeons must be the priority. We propose a strategic design for extending surgical education missions throughout the Western Hemisphere in order to transfer modern surgical skills to local neurosurgeons. A selection criteria and structure for targeted missions is a derivative of logistical and pedagogical lessons ascertained from previous missions by our teams in Peru and Ukraine. Outreach programs should be applied to hospitals in capital cities to serve as a central referral center for maximal impact with fiscal efficiency. The host country should fulfill several criteria, including demonstration of geopolitical stability in combination with lack of modern neurosurgical care and equipment. The mission strategy is outlined as three to four 1-week visits with an initial site evaluation to establish a relationship with the hospital administration and host surgeons. Each visit should be characterized by collaboration between visiting and host surgeons on increasingly complex cases, with progressive transfer of skills over time. A strategic approach for surgical outreach missions should be built on collaboration and camaraderie between visiting and local neurosurgeons, with the mutual objective of cost-effective targeted renovation of their surgical equipment and skill repertoire.

  14. 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.

  15. Robotic Stereotaxy in Cranial Neurosurgery: A Qualitative Systematic Review.

    Science.gov (United States)

    Fomenko, Anton; Serletis, Demitre

    2017-12-14

    Modern-day stereotactic techniques have evolved to tackle the neurosurgical challenge of accurately and reproducibly accessing specific brain targets. Neurosurgical advances have been made in synergy with sophisticated technological developments and engineering innovations such as automated robotic platforms. Robotic systems offer a unique combination of dexterity, durability, indefatigability, and precision. To perform a systematic review of robotic integration for cranial stereotactic guidance in neurosurgery. Specifically, we comprehensively analyze the strengths and weaknesses of a spectrum of robotic technologies, past and present, including details pertaining to each system's kinematic specifications and targeting accuracy profiles. Eligible articles on human clinical applications of cranial robotic-guided stereotactic systems between 1985 and 2017 were extracted from several electronic databases, with a focus on stereotactic biopsy procedures, stereoelectroencephalography, and deep brain stimulation electrode insertion. Cranial robotic stereotactic systems feature serial or parallel architectures with 4 to 7 degrees of freedom, and frame-based or frameless registration. Indications for robotic assistance are diversifying, and include stereotactic biopsy, deep brain stimulation and stereoelectroencephalography electrode placement, ventriculostomy, and ablation procedures. Complication rates are low, and mainly consist of hemorrhage. Newer systems benefit from increasing targeting accuracy, intraoperative imaging ability, improved safety profiles, and reduced operating times. We highlight emerging future directions pertaining to the integration of robotic technologies into future neurosurgical procedures. Notably, a trend toward miniaturization, cost-effectiveness, frameless registration, and increasing safety and accuracy characterize successful stereotactic robotic technologies. Copyright © 2017 by the Congress of Neurological Surgeons

  16. Investigating the scope of resident patient care handoffs within neurosurgery.

    Science.gov (United States)

    Babu, Maya A; Nahed, Brian V; Heary, Robert F

    2012-01-01

    Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs. Survey results were analyzed using tabulations. 449 surveys were completed yielding a 56% response rate. 63% of neurosurgical residents surveyed had not received formal instruction in what constitutes an effective handoff; 24% believe there is high to moderate variability among their co-residents in terms of the quality of the handoff provided; 55% experience three or more interruptions during handoffs on average. 90% of neurosurgical residents surveyed say that handoff most often occurs in a quiet, private area and 56% report a high level of comfort for knowing the potential acute, critical issues affecting a patient when receiving a handoff. There needs to be more focused education devoted to learning effective patient-care handoffs in neurosurgical training programs. Increasingly, handing off a patient adequately and safely is becoming a required skill of residency.

  17. Investigating the scope of resident patient care handoffs within neurosurgery.

    Directory of Open Access Journals (Sweden)

    Maya A Babu

    Full Text Available INTRODUCTION: Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. METHODS: A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs. Survey results were analyzed using tabulations. RESULTS: 449 surveys were completed yielding a 56% response rate. 63% of neurosurgical residents surveyed had not received formal instruction in what constitutes an effective handoff; 24% believe there is high to moderate variability among their co-residents in terms of the quality of the handoff provided; 55% experience three or more interruptions during handoffs on average. 90% of neurosurgical residents surveyed say that handoff most often occurs in a quiet, private area and 56% report a high level of comfort for knowing the potential acute, critical issues affecting a patient when receiving a handoff. CONCLUSIONS: There needs to be more focused education devoted to learning effective patient-care handoffs in neurosurgical training programs. Increasingly, handing off a patient adequately and safely is becoming a required skill of residency.

  18. Using Electronic Noses to Detect Tumors During Neurosurgery

    Science.gov (United States)

    Homer, Margie L.; Ryan, Margaret A.; Lara, Liana M.; Kateb, Babak; Chen, Mike

    2008-01-01

    It has been proposed to develop special-purpose electronic noses and algorithms for processing the digitized outputs of the electronic noses for determining whether tissue exposed during neurosurgery is cancerous. At present, visual inspection by a surgeon is the only available intraoperative technique for detecting cancerous tissue. Implementation of the proposal would help to satisfy a desire, expressed by some neurosurgeons, for an intraoperative technique for determining whether all of a brain tumor has been removed. The electronic-nose technique could complement multimodal imaging techniques, which have also been proposed as means of detecting cancerous tissue. There are also other potential applications of the electronic-nose technique in general diagnosis of abnormal tissue. In preliminary experiments performed to assess the viability of the proposal, the problem of distinguishing between different types of cultured cells was substituted for the problem of distinguishing between normal and abnormal specimens of the same type of tissue. The figure presents data from one experiment, illustrating differences between patterns that could be used to distinguish between two types of cultured cancer cells. Further development can be expected to include studies directed toward answering questions concerning not only the possibility of distinguishing among various types of normal and abnormal tissue but also distinguishing between tissues of interest and other odorous substances that may be present in medical settings.

  19. Operative Duration and Risk of Surgical Site Infection in Neurosurgery.

    Science.gov (United States)

    Bekelis, Kimon; Coy, Shannon; Simmons, Nathan

    2016-10-01

    The association of surgical duration with the risk of surgical site infection (SSI) has not been quantified in neurosurgery. We investigated the association of operative duration in neurosurgical procedures with the incidence of SSI. We performed a retrospective cohort study involving patients who underwent neurosurgical procedures from 2005 to 2012 and were registered in the American College of Surgeons National Quality Improvement Project registry. To control for confounding, we used multivariable regression models and propensity score conditioning. During the study period there were 94,744 patients who underwent a neurosurgical procedure and met the inclusion criteria. Of these patients, 4.1% developed a postoperative SSI within 30 days. Multivariable logistic regression showed an association between longer operative duration with higher incidence of SSI (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.16-1.20). Compared with procedures of moderate duration (third quintile, 40th-60th percentile), patients undergoing the longest procedures (>80th percentile) had higher odds (OR, 2.07; 95% CI, 1.86-2.31) of developing SSI. The shortest procedures (operative duration was associated with increased incidence of SSI for neurosurgical procedures. These results can be used by neurosurgeons to inform operative management and to stratify patients with regard to SSI risk. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Lessons learned using HAMMLAB experimenter systems: Input for HAMMLAB 2000 functional requirements

    International Nuclear Information System (INIS)

    Sebok, Angelia L.

    1998-02-01

    To design a usable HAMMLAB 2000, lessons learned from use of the existing HAMMLAB must be documented. User suggestions are important and must be taken into account. Different roles in HAMMLAB experimental sessions are identified, and major functions of each role were specified. A series of questionnaires were developed and administered to different users of HAMMLAB, each tailored to the individual job description. The results of those questionnaires are included in this report. Previous HAMMLAB modification recommendations were also reviewed, to provide input to this document. A trial experimental session was also conducted, to give an overview of the tasks in HAMMLAB. (author)

  1. Identification and adjustment of experimental occlusal interference using functional magnetic resonance imaging

    OpenAIRE

    Oda, Masafumi; Yoshino, Kenichi; Tanaka, Tatsurou; Shiiba, Shunji; Makihara, Eri; Miyamoto, Ikuya; Nogami, Shinnosuke; Kito, Shinji; Wakasugi-Sato, Nao; Matsumoto-Takeda, Shinobu; Nishimura, Shun; Murakami, Keita; Koga, Masahiro; Kawagishi, Shigenori; Yoshioka, Izumi

    2014-01-01

    Background The purpose of this study was to use functional magnetic resonance imaging (fMRI) to quantify changes in brain activity during experimental occlusal interference. Methods Fourteen healthy volunteers performed a rhythmical tapping occlusion task with experimental occlusal interference of the right molar tooth at 0 mm (no occlusion), 0.5 mm, and 0.75 mm. The blood-oxygen-level dependent (BOLD) signal was quantified using statistical parametric mapping and compared between rest period...

  2. Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations.

    Science.gov (United States)

    van de Streek, Jacco; Neumann, Marcus A

    2010-10-01

    This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 A either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect.

  3. Identification and adjustment of experimental occlusal interference using functional magnetic resonance imaging.

    Science.gov (United States)

    Oda, Masafumi; Yoshino, Kenichi; Tanaka, Tatsurou; Shiiba, Shunji; Makihara, Eri; Miyamoto, Ikuya; Nogami, Shinnosuke; Kito, Shinji; Wakasugi-Sato, Nao; Matsumoto-Takeda, Shinobu; Nishimura, Shun; Murakami, Keita; Koga, Masahiro; Kawagishi, Shigenori; Yoshioka, Izumi; Masumi, Shin-Ichi; Kimura, Mitsutaka; Morimoto, Yasuhiro

    2014-10-10

    The purpose of this study was to use functional magnetic resonance imaging (fMRI) to quantify changes in brain activity during experimental occlusal interference. Fourteen healthy volunteers performed a rhythmical tapping occlusion task with experimental occlusal interference of the right molar tooth at 0 mm (no occlusion), 0.5 mm, and 0.75 mm. The blood-oxygen-level dependent (BOLD) signal was quantified using statistical parametric mapping and compared between rest periods and task periods. In tapping tasks with experimental occlusal interference of 0.75 mm or 0.5 mm, there was clear activation of the contralateral teeth-related primary sensory cortex and Brodmann's area 46. At 0 and 30 minutes after removal of the experimental occlusal interference, the activation clearly appeared in the bilateral teeth-related primary sensory cortices and Brodmann's area 46. At 60 minutes after the removal of the experimental occlusal interference, the activation of Brodmann's area 46 had disappeared, and only the bilateral teeth-related primary sensory cortices were active. The present results suggest that adjustments for experimental occlusal interference can be objectively evaluated using fMRI. We expect that this method of evaluating adjustments in occlusal interference, combined with fMRI and the tapping task, could be applied clinically in the future.

  4. 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.

  5. 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

  6. 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

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

    International Nuclear Information System (INIS)

    Kim, Hyunsu; Yoon, Jong-Yun

    2017-01-01

    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

  8. 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.

  9. A global analysis of recent experimental results: How well determined are the parton distribution functions?

    International Nuclear Information System (INIS)

    Morfin, J.G.

    1990-08-01

    Following is a brief summary of the results of an analysis of experimental data performed to extract the patron distribution functions. In contrast to other global analyses, this study investigated how the fit results depend on: Experimental Systematic Errors; Kinematic Cuts on the Analyzed Data and Choice of Initial Functional Forms, with a prime goal being a close look at the range of low-x behavior allowed by data. This is crucial for predictions for the SSC/LHC, HERA, and even at Tevatron Collider energies. Since all details can be found in the just released Fermilab preprint Parton Distributions from a Global QCD Analysis of Deep Inelastic Scattering and Lepton-Pair Production by J. G. M. and Wu-Ki Tung, this summary will be only a brief outline of major results. 11 refs., 13 figs

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

    KAUST Repository

    Hussaini, Irfan; Wang, Chao-Yang

    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.

  11. Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders

    Science.gov (United States)

    Nuttin, Bart; Wu, Hemmings; Mayberg, Helen; Hariz, Marwan; Gabriëls, Loes; Galert, Thorsten; Merkel, Reinhard; Kubu, Cynthia; Vilela-Filho, Osvaldo; Matthews, Keith; Taira, Takaomi; Lozano, Andres M; Schechtmann, Gastón; Doshi, Paresh; Broggi, Giovanni; Régis, Jean; Alkhani, Ahmed; Sun, Bomin; Eljamel, Sam; Schulder, Michael; Kaplitt, Michael; Eskandar, Emad; Rezai, Ali; Krauss, Joachim K; Hilven, Paulien; Schuurman, Rick; Ruiz, Pedro; Chang, Jin Woo; Cosyns, Paul; Lipsman, Nir; Voges, Juergen; Cosgrove, Rees; Li, Yongjie; Schlaepfer, Thomas

    2014-01-01

    Background For patients with psychiatric illnesses remaining refractory to ‘standard’ therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups. Methods To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments. Findings The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered ‘established’ in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients. Interpretation This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety. PMID:24444853

  12. 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.

  13. Causes and Timing of Unplanned Early Readmission After Neurosurgery.

    Science.gov (United States)

    Taylor, Blake E S; Youngerman, Brett E; Goldstein, Hannah; Kabat, Daniel H; Appelboom, Geoffrey; Gold, William E; Connolly, Edward Sander

    2016-09-01

    Reducing the rate of 30-day hospital readmission has become a priority in healthcare quality improvement policy, with a focus on better characterizing the reasons for unplanned readmission. In neurosurgery, however, peer-reviewed analyses describing the patterns of readmission have been limited in their number and generalizability. To determine the incidence, timing, and causes of 30-day readmission after neurosurgical procedures. We conducted a retrospective longitudinal study from 2009 to 2012 using the Statewide Planning And Research Cooperative System, which collects patient-level details for all admissions and discharges within New York. We identified patients readmitted within 30 days of initial discharge. The rate of, reasons for, and time to readmission were determined overall and within 4 subgroups: craniotomies, cranial surgery without craniotomy, spine, and neuroendovascular procedures. There were 163 743 index admissions, of whom 14 791 (9.03%) were readmitted. The most common reasons for unplanned readmission were infection (29.52%) and medical complications (19.22%). Median time to readmission was 11 days, with hemorrhagic strokes and seizures occurring earlier, and medical complications and infections occurring later. Readmission rates were highest among patients undergoing cerebrospinal fluid shunt revision and malignant tumor resection (15.57%-22.60%). Spinal decompressions, however, accounted for the largest volume of readmissions (33.13%). Many readmissions may be preventable and occur at predictable time intervals. The causes and timing of readmission vary significantly across neurosurgical subgroups. Future studies should focus on detecting specific complications in select cohorts at predefined time points, which may allow for interventions to lower costs and reduce patient morbidity. CSF, cerebrospinal fluidIQR, interquartile rangeSPARCS, Statewide Planning And Research Cooperative System.

  14. Robotic System for MRI-Guided Stereotactic Neurosurgery

    Science.gov (United States)

    Li, Gang; Cole, Gregory A.; Shang, Weijian; Harrington, Kevin; Camilo, Alex; Pilitsis, Julie G.; Fischer, Gregory S.

    2015-01-01

    Stereotaxy is a neurosurgical technique that can take several hours to reach a specific target, typically utilizing a mechanical frame and guided by preoperative imaging. An error in any one of the numerous steps or deviations of the target anatomy from the preoperative plan such as brain shift (up to 20 mm), may affect the targeting accuracy and thus the treatment effectiveness. Moreover, because the procedure is typically performed through a small burr hole opening in the skull that prevents tissue visualization, the intervention is basically “blind” for the operator with limited means of intraoperative confirmation that may result in reduced accuracy and safety. The presented system is intended to address the clinical needs for enhanced efficiency, accuracy, and safety of image-guided stereotactic neurosurgery for Deep Brain Stimulation (DBS) lead placement. The work describes a magnetic resonance imaging (MRI)-guided, robotically actuated stereotactic neural intervention system for deep brain stimulation procedure, which offers the potential of reducing procedure duration while improving targeting accuracy and enhancing safety. This is achieved through simultaneous robotic manipulation of the instrument and interactively updated in situ MRI guidance that enables visualization of the anatomy and interventional instrument. During simultaneous actuation and imaging, the system has demonstrated less than 15% signal-to-noise ratio (SNR) variation and less than 0.20% geometric distortion artifact without affecting the imaging usability to visualize and guide the procedure. Optical tracking and MRI phantom experiments streamline the clinical workflow of the prototype system, corroborating targeting accuracy with 3-axis root mean square error 1.38 ± 0.45 mm in tip position and 2.03 ± 0.58° in insertion angle. PMID:25376035

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.; Wan, C.H., E-mail: wancaihua@iphy.ac.cn; Yuan, Z.H.; Fang, C.; Kong, W.J.; Wu, H.; Zhang, Q.T.; Tao, B.S.; Han, X.F., E-mail: xfhan@iphy.ac.cn

    2017-04-15

    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. - Highlights: • Experimental demonstration of spin logic cell based on spin Hall effect. • Five logic functions are realized in a single logic cell. • The logic cell is reprogrammable. • Information in the cell is symmetry-protected. • The logic cell can be easily expanded to logic gate array.

  16. Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

    Science.gov (United States)

    Sison Escaño, Mary Clare; Lacdao Arevalo, Ryan; Gyenge, Elod; Kasai, Hideaki

    2014-09-01

    The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH4- on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements.

  17. Validation of MCDS by comparison of predicted with experimental velocity distribution functions in rarefied normal shocks

    Science.gov (United States)

    Pham-Van-diep, Gerald C.; Erwin, Daniel A.

    1989-01-01

    Velocity distribution functions in normal shock waves in argon and helium are calculated using Monte Carlo direct simulation. These are compared with experimental results for argon at M = 7.18 and for helium at M = 1.59 and 20. For both argon and helium, the variable-hard-sphere (VHS) model is used for the elastic scattering cross section, with the velocity dependence derived from a viscosity-temperature power-law relationship in the way normally used by Bird (1976).

  18. Central neuropeptide Y (NPH) expression and function : role in stress, experimental anxiety, and cognition

    OpenAIRE

    Thorsell, Annika

    2000-01-01

    Neuropeptide Y (NPY), a 36 amino acid peptide abundantly expressed throughout the mammalian nervous system, has been implicated in experimental anxiety and stress related responses, feeding, and learning and memory. These functions are mediated via different receptor subtype populations (Y1-Y6), all belonging to the G-protein coupled receptor superfamily. The Y1 -subtype has been shown to mediate the anxiolytic effects of NPY, while the Y2 subtype is involved in regulation o...

  19. Practical guidelines for setting up neurosurgery skills training cadaver laboratory in India.

    Science.gov (United States)

    Suri, Ashish; Roy, Tara Sankar; Lalwani, Sanjeev; Deo, Rama Chandra; Tripathi, Manjul; Dhingra, Renu; Bhardwaj, Daya Nand; Sharma, Bhawani Shankar

    2014-01-01

    Though the necessity of cadaver dissection is felt by the medical fraternity, and described as early as 600 BC, in India, there are no practical guidelines available in the world literature for setting up a basic cadaver dissection laboratory for neurosurgery skills training. Hands-on dissection practice on microscopic and endoscopic procedures is essential in technologically demanding modern neurosurgery training where ethical issues, cost constraints, medico-legal pitfalls, and resident duty time restrictions have resulted in lesser opportunities to learn. Collaboration of anatomy, forensic medicine, and neurosurgery is essential for development of a workflow of cadaver procurement, preservation, storage, dissection, and disposal along with setting up the guidelines for ethical and legal concerns.

  20. From idea to publication: Publication rates of theses in neurosurgery from Turkey.

    Science.gov (United States)

    Öğrenci, Ahmet; Ekşi, Murat Şakir; Özcan-Ekşi, Emel Ece; Koban, Orkun

    2016-01-01

    Thesis at the end of residency is considered as the complementary component of postgraduate training. In this respect, thesis helps the residents learn how to ask structured questions, set up the most appropriate study design, conduct the study, retrieve study results and write conclusions with clinical implications. To the best of our knowledge, the publication rates of theses in the field of neurosurgery have not been reported before. Our aim was to find out publication rates of theses in neurosurgery specialty, in this descriptive study. The database of Higher Education Council of Turkey, which includes the theses of residents in only university hospitals, was screened between years 2004 and 2013. After retrieving the theses from the database; we used search engines to find out the theses published in any SCI/SCI-E-indexed journals. For this purpose, the title of the theses and the author names were used as keywords for searching. Data was presented in a descriptive form as absolute numbers and percentages. We retrieved 164 theses written by former residents in neurosurgery using the database. Among 164 theses, 18% (national journals: 9; international journals: 21) were published in SCI/SCI-E indexed journals. Publication rates of theses in neurosurgery are low as they are in the other specialties of medicine. Our study is a descriptive research, to give an idea about publication rates of theses in neurosurgery. Further studies are required to understand the underlying factors, which are responsible for the limited success in publication of theses in neurosurgery. Copyright © 2015 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  1. Evaluation of Sensory and Motor Skills in Neurosurgery Applicants Using a Virtual Reality Neurosurgical Simulator: The Sensory-Motor Quotient.

    Science.gov (United States)

    Roitberg, Ben Z; Kania, Patrick; Luciano, Cristian; Dharmavaram, Naga; Banerjee, Pat

    2015-01-01

    Manual skill is an important attribute for any surgeon. Current methods to evaluate sensory-motor skills in neurosurgical residency applicants are limited. We aim to develop an objective multifaceted measure of sensory-motor skills using a virtual reality surgical simulator. A set of 3 tests of sensory-motor function was performed using a 3-dimensional surgical simulator with head and arm tracking, collocalization, and haptic feedback. (1) Trajectory planning: virtual reality drilling of a pedicle. Entry point, target point, and trajectory were scored-evaluating spatial memory and orientation. (2) Motor planning: sequence, timing, and precision: hemostasis in a postresection cavity in the brain. (3) Haptic perception: touching virtual spheres to determine which is softest of the group, with progressive difficulty. Results were analyzed individually and for a combined score of all the tasks. The University of Chicago Hospital's tertiary care academic center. A total of 95 consecutive applicants interviewed at a neurosurgery residency program over 2 years were offered anonymous participation in the study; in 2 cohorts, 36 participants in year 1 and 27 participants in year 2 (validation cohort) agreed and completed all the tasks. We also tested 10 first-year medical students and 4 first- and second-year neurosurgery residents. A cumulative score was generated from the 3 tests. The mean score was 14.47 (standard deviation = 4.37), median score was 13.42, best score was 8.41, and worst score was 30.26. Separate analysis of applicants from each of 2 years yielded nearly identical results. Residents tended to cluster on the better performance side, and first-year students were not different from applicants. (1) Our cumulative score measures sensory-motor skills in an objective and reproducible way. (2) Better performance by residents hints at validity for neurosurgery. (3) We were able to demonstrate good psychometric qualities and generate a proposed sensory

  2. 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…

  3. Experimental and evaluated data on the discrete level excitation function of the 238U(n,n') reaction

    International Nuclear Information System (INIS)

    Simakov, S.P.

    1991-01-01

    Experimental data on the 238 U excitation function are compiled and analyzed. The experimental data are compared with the evaluated data from the BNAB, ENDF/B-IV and ENDL-78 evaluated data libraries. It is shown that the BNAB evaluated data are in good agreement with the existing experimental data, including new results from recent experiments. (author). 26 refs, 2 figs, 2 tabs

  4. Code REX to fit experimental data to exponential functions and graphics plotting

    International Nuclear Information System (INIS)

    Romero, L.; Travesi, A.

    1983-01-01

    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 x , Y=A X 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

  5. Constantin N. Arseni (1912-1994) centenary: the birth of modern neurosurgery in Romania.

    Science.gov (United States)

    Dinca, Eduard B; Banu, Matei; Ciurea, Alexandru V

    2014-01-01

    Prof. Dr. Constantin N. Arseni and his mentor, Prof. Dr. D. Bagdasar, are revered by later generations of doctors as the forefathers of Romanian neurosurgery. In 2012, we have celebrated 100 years since Prof. Arseni's birth in a small village within a deprived area of the country. Through his talents and perseveration, he rose to be a neurosurgical school creator and one of the most prominent figures in 20th-century Eastern European neurosurgery. This historical vignette is a modest tribute to his legacy and tells the story of his titanic endeavor. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Statement of Ethics in Neurosurgery of the World Federation of Neurosurgical Societies.

    Science.gov (United States)

    Umansky, Felix; Black, Peter L; DiRocco, Concenzio; Ferrer, Enrique; Goel, Atul; Malik, Ghaus M; Mathiesen, Tiit; Mendez, Ivar; Palmer, James D; Juanotena, Jorge Rodriguez; Fraifeld, Shifra; Rosenfeld, Jeffrey V

    2011-01-01

    This Statement of Ethics in Neurosurgery was developed by the Committee for Ethics and Medico-Legal Affairs of the World Federation of Neurosurgical Societies to help neurosurgeons resolve problems in the treatment of individual patients and meet obligations to the larger society. This document is intended as a framework rather than a set of rules. It cannot cover every situation and should be used with flexibility. However, it is our intent that the fundamental principles enunciated here should serve as a guide in the day-to-day practice of neurosurgery. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Numbers and functions from a classical-experimental mathematician's point of view

    CERN Document Server

    Moll, Victor H

    2012-01-01

    New mathematics often comes about by probing what is already known. Mathematicians will change the parameters in a familiar calculation or explore the essential ingredients of a classic proof. Almost magically, new ideas emerge from this process. This book examines elementary functions, such as those encountered in calculus courses, from this point of view of experimental mathematics. The focus is on exploring the connections between these functions and topics in number theory and combinatorics. There is also an emphasis throughout the book on how current mathematical software can be used to discover and prove interesting properties of these functions. The book provides a transition between elementary mathematics and more advanced topics, trying to make this transition as smooth as possible. Many topics occur in the book, but they are all part of a bigger picture of mathematics. By delving into a variety of them, the reader will develop this broad view. The large collection of problems is an essential part of...

  8. Identification of material properties of orthotropic composite plate using experimental frequency response function data

    Science.gov (United States)

    Tam, Jun Hui; Ong, Zhi Chao; Ismail, Zubaidah; Ang, Bee Chin; Khoo, Shin Yee

    2018-05-01

    The demand for composite materials is increasing due to their great superiority in material properties, e.g., lightweight, high strength and high corrosion resistance. As a result, the invention of composite materials of diverse properties is becoming prevalent, and thus, leading to the development of material identification methods for composite materials. Conventional identification methods are destructive, time-consuming and costly. Therefore, an accurate identification approach is proposed to circumvent these drawbacks, involving the use of Frequency Response Function (FRF) error function defined by the correlation discrepancy between experimental and Finite-Element generated FRFs. A square E-glass epoxy composite plate is investigated under several different configurations of boundary conditions. It is notable that the experimental FRFs are used as the correlation reference, such that, during computation, the predicted FRFs are continuously updated with reference to the experimental FRFs until achieving a solution. The final identified elastic properties, namely in-plane elastic moduli, Ex and Ey, in-plane shear modulus, Gxy, and major Poisson's ratio, vxy of the composite plate are subsequently compared to the benchmark parameters as well as with those obtained using modal-based approach. As compared to the modal-based approach, the proposed method is found to have yielded relatively better results. This can be explained by the direct employment of raw data in the proposed method that avoids errors that might incur during the stage of modal extraction.

  9. Defensive Medicine in U.S. Spine Neurosurgery.

    Science.gov (United States)

    Din, Ryan S; Yan, Sandra C; Cote, David J; Acosta, Michael A; Smith, Timothy R

    2017-02-01

    Observational cross-sectional survey. To compare defensive practices of U.S. spine and nonspine neurosurgeons in the context of state medical liability risk. Defensive medicine is a commonly reported and costly phenomenon in neurosurgery. Although state liability risk is thought to contribute greatly to defensive practice, variation within neurosurgical specialties has not been well explored. A validated, online survey was sent via email to 3344 members of the American Board of Neurological Surgeons. The instrument contained eight question domains: surgeon characteristics, patient characteristics, practice type, insurance type, surgeon liability profile, basic surgeon reimbursement, surgeon perceptions of medical legal environment, and the practice of defensive medicine. The overall response rate was 30.6% (n = 1026), including 499 neurosurgeons performing mainly spine procedures (48.6%). Spine neurosurgeons had a similar average practice duration as nonspine neurosurgeons (16.6 vs 16.9 years, P = 0.64) and comparable lifetime case volume (4767 vs 4,703, P = 0.71). The average annual malpractice premium for spine neurosurgeons was similar to nonspine neurosurgeons ($104,480.52 vs $101,721.76, P = 0.60). On average, spine neurosurgeons had a significantly higher rate of ordering labs, medications, referrals, procedures, and imaging solely for liability concerns compared with nonspine neurosurgeons (89.2% vs 84.6%, P = 0.031). Multivariate analysis revealed that spine neurosurgeons were roughly 3 times more likely to practice defensively compared with nonspine neurosurgeons (odds ratio, OR = 2.9, P = 0.001) when controlling for high-risk procedures (OR = 7.8, P < 0.001), annual malpractice premium (OR = 3.3, P = 0.01), percentage of patients publicly insured (OR = 1.1, P = 0.80), malpractice claims in the last 3 years (OR = 1.13, P = 0.71), and state medical-legal environment (OR = 1.3, P = 0

  10. Pharmacologic and radioimmunologic studies on some endocrine functions in experimental hypothyreosis

    International Nuclear Information System (INIS)

    Boyadzhieva, N.; Visheva, N.; Milanov, S.; Krysteva, S.

    1990-01-01

    The study was performed on two groups of rats: 1) sexually mature males with experimental hypothyreosis produced with methisol 2) progeny of female rats with hypothyreosis. Prolactin and growth hormone levels were determined by radioimmunoassay. Changes were found in rats with experimental hypothyreosis. In the progeny there were changes only in prolactin level. The content of dopamine and serotonine in the brain of the progeny were also determined. Changes were found in the dopamine content, which correlated with the elevated prolactin level. The hypothesis is advanced that disturbances exist in the central neuro-mediatory mechanisms during the pre-and postnatal life, controlling the functions of the pituitary-thyroid axis and the production and release of prolactin and growth hormone. 3 tabs., 7 refs

  11. EXPERIMENTAL DETERMINATION OF DOUBLE VIBE FUNCTION PARAMETERS IN DIESEL ENGINES WITH BIODIESEL

    Directory of Open Access Journals (Sweden)

    Radivoje B Pešić

    2010-01-01

    Full Text Available A zero-dimensional, one zone model of engine cycle for steady-state regimes of engines and a simplified procedure for indicator diagrams analysis have been developed at the Laboratory for internal combustion engines, fuels and lubricants of the Faculty of Mechanical Engineering in Kragujevac. In addition to experimental research, thermodynamic modeling of working process of diesel engine with direct injection has been presented in this paper. The simplified procedure for indicator diagrams analysis has been applied, also. The basic problem, a selection of shape parameters of double Vibe function used for modeling the engine operation process, has been solved. The influence of biodiesel fuel and engine working regimes on the start of combustion, combustion duration and shape parameter of double Vibe was determined by a least square fit of experimental heat release curve.

  12. Functional inference of complex anatomical tendinous networks at a macroscopic scale via sparse experimentation.

    Science.gov (United States)

    Saxena, Anupam; Lipson, Hod; Valero-Cuevas, Francisco J

    2012-01-01

    In systems and computational biology, much effort is devoted to functional identification of systems and networks at the molecular-or cellular scale. However, similarly important networks exist at anatomical scales such as the tendon network of human fingers: the complex array of collagen fibers that transmits and distributes muscle forces to finger joints. This network is critical to the versatility of the human hand, and its function has been debated since at least the 16(th) century. Here, we experimentally infer the structure (both topology and parameter values) of this network through sparse interrogation with force inputs. A population of models representing this structure co-evolves in simulation with a population of informative future force inputs via the predator-prey estimation-exploration algorithm. Model fitness depends on their ability to explain experimental data, while the fitness of future force inputs depends on causing maximal functional discrepancy among current models. We validate our approach by inferring two known synthetic Latex networks, and one anatomical tendon network harvested from a cadaver's middle finger. We find that functionally similar but structurally diverse models can exist within a narrow range of the training set and cross-validation errors. For the Latex networks, models with low training set error [functional structure of complex anatomical networks. This work expands current bioinformatics inference approaches by demonstrating that sparse, yet informative interrogation of biological specimens holds significant computational advantages in accurate and efficient inference over random testing, or assuming model topology and only inferring parameters values. These findings also hold clues to both our evolutionary history and the development of versatile machines.

  13. ISSLS prize winner: integrating theoretical and experimental methods for functional tissue engineering of the annulus fibrosus.

    Science.gov (United States)

    Nerurkar, Nandan L; Mauck, Robert L; Elliott, Dawn M

    2008-12-01

    Integrating theoretical and experimental approaches for annulus fibrosus (AF) functional tissue engineering. Apply a hyperelastic constitutive model to characterize the evolution of engineered AF via scalar model parameters. Validate the model and predict the response of engineered constructs to physiologic loading scenarios. There is need for a tissue engineered replacement for degenerate AF. When evaluating engineered replacements for load-bearing tissues, it is necessary to evaluate mechanical function with respect to the native tissue, including nonlinearity and anisotropy. Aligned nanofibrous poly-epsilon-caprolactone scaffolds with prescribed fiber angles were seeded with bovine AF cells and analyzed over 8 weeks, using experimental (mechanical testing, biochemistry, histology) and theoretical methods (a hyperelastic fiber-reinforced constitutive model). The linear region modulus for phi = 0 degrees constructs increased by approximately 25 MPa, and for phi = 90 degrees by approximately 2 MPa from 1 day to 8 weeks in culture. Infiltration and proliferation of AF cells into the scaffold and abundant deposition of s-GAG and aligned collagen was observed. The constitutive model had excellent fits to experimental data to yield matrix and fiber parameters that increased with time in culture. Correlations were observed between biochemical measures and model parameters. The model was successfully validated and used to simulate time-varying responses of engineered AF under shear and biaxial loading. AF cells seeded on nanofibrous scaffolds elaborated an organized, anisotropic AF-like extracellular matrix, resulting in improved mechanical properties. A hyperelastic fiber-reinforced constitutive model characterized the functional evolution of engineered AF constructs, and was used to simulate physiologically relevant loading configurations. Model predictions demonstrated that fibers resist shear even when the shearing direction does not coincide with the fiber direction

  14. Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

    International Nuclear Information System (INIS)

    Sison Escaño, Mary Clare; Arevalo, Ryan Lacdao; Kasai, Hideaki; Gyenge, Elod

    2014-01-01

    The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH 4 − on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements. (topical review)

  15. Experimental results on polarized structure functions in deep inelastic lepton-nucleon scattering

    International Nuclear Information System (INIS)

    Stuart, L.

    1994-08-01

    A summary is given of experimental results on spin structure functions of the proton g 1 p (x,Q 2 ), deuteron g 1 d (x,Q 2 ), and neutron g 1 n (x,Q 2 ) as measured in deep inelastic scattering of polarized leptons from a polarized target. All results are consistent with the Bjorken sum rule predictions at the Q 2 of each experiment. The data do not support the Ellis-Jaffe sum rule prediction for the proton which implies that the hencity carried by the strange quark may be nonzero and that the net quark helicity is smaller than expected from simple quark models

  16. 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.

  17. 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…

  18. 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.

  19. The contributions of W.D. Stevenson to the development of neurosurgery in Atlantic Canada.

    Science.gov (United States)

    Mukhida, K; Mendez, I

    1999-08-01

    The establishment of a neurosurgical department in Halifax in January 1948 marked the beginnings of the first dedicated neurosurgical service in Atlantic Canada. The development of neurosurgery in Halifax occurred in a receptive place and time. The Victoria General Hospital, the region's largest tertiary care centre, and the Dalhousie University Faculty of Medicine were in a period of growth associated with medical specialization and departmentalization, changes inspired in part by the Flexner Report of 1910. Atlantic Canadians during this period were increasingly looking to specialists for their medical care. Although this social environment encouraged the establishment of surgical specialty services, the development of neurosurgery in Halifax, as in other parts of Canada, was closely associated with the efforts of individual neurosurgeons, such as William D. Stevenson. After training with Kenneth G. McKenzie in Toronto, Stevenson was recruited to Halifax and established the first neurosurgical department in Atlantic Canada. From the outset and over his twenty-six years as Department Head at the Victoria General Hospital and Dalhousie University, Stevenson worked to maintain the department's commitment to clinical practice, medical education, and research. Although Stevenson single-handedly ran the service for several years after its inception, by the time of his retirement in 1974 the neurosurgery department had grown to include five attending staff surgeons who performed over two thousand procedures each year. This paper highlights the importance of Stevenson's contributions to the development of neurosurgery in Atlantic Canada within the context of the social and medical environment of the region.

  20. Smartphone Usage Patterns by Canadian Neurosurgery Residents: A National Cross-Sectional Survey.

    Science.gov (United States)

    Kameda-Smith, Michelle Masayo; Iorio-Morin, Christian; Winkler-Schwartz, Alexander; Ahmed, Uzair S; Bergeron, David; Bigder, Mark; Dakson, Ayoub; Elliott, Cameron A; Guha, Daipayan; Lavergne, Pascal; Makarenko, Serge; Taccone, Michael S; Tso, Michael; Wang, Bill; Fortin, David

    2018-03-01

    Smartphones and their apps are used ubiquitously in medical practice. However, in some cases their use can be at odds with current patient data safety regulations such as Canada's Personal Health Information Protection Act of 2004. To assess current practices and inform mobile application development, we sought to better understand mobile device usage patterns among Canadian neurosurgery residents. Through the Canadian Neurosurgery Research Collaborative, an online survey characterizing smartphone ownership and usage patterns was developed and sent to all Canadian neurosurgery resident in April of 2016. Questionnaires were collected and completed surveys analyzed. Of 146 eligible residents, 76 returned completed surveys (52% response rate). Of these 99% of respondents owned a smartphone, with 79% running on Apple's iOS. Four general mobile uses were identified: 1) communication between members of the medical team, 2) decision support, 3) medical reference, and 4) documentation through medical photography. Communication and photography were areas where the most obvious breaches in the Canadian Personal Health Information Protection Act were noted, with 89% of respondents taking pictures of patients' radiologic studies and 75% exchanging them with Short Message System. Hospital policies had no impact on user behaviors. Smartphones are used daily by most neurosurgery residents. Identified usage patterns are associated with perceived gains in efficacy and challenges in privacy and data reliability. We believe creating and improving workflows that address these usage patterns has a greater potential to improve privacy than changing policies and enforcing regulations. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Roots of neuroanatomy, neurology, and neurosurgery as found in the Bible and Talmud.

    Science.gov (United States)

    Tubbs, R Shane; Loukas, Marios; Shoja, Mohammadali M; Cohen-Gadol, Aaron A; Wellons, John C; Oakes, W Jerry

    2008-07-01

    Historical observations and interpretations regarding the treatment of components of the nervous system can be found in the writings of the Bible and Talmud. A review of topics germane to modern neuroanatomy, neurology, and neurosurgery from these early, rich writings is presented herein. These historic writings provide a glimpse into the early understanding, description, and treatment of pathologies of the nervous system.

  2. An Experimental Study of Muscle Coordination and Function during Human Locomotion

    Directory of Open Access Journals (Sweden)

    Hirai Hiroaki

    2011-12-01

    Full Text Available How humans solve the ill-posed problem of motor control is still a mystery. In this paper, we attempt to decompose human walking and running as the main movements of a leg into units of motor function. We introduce the key concept of “A-A ratio,” defined as the ratio of an extensor muscle’s electromyography (EMG signal to the sum of agonist and antagonist muscles’ EMG signals. Human walking and running are then decomposed into two units of motor function by applying Principal Component Analysis (PCA to the A-A ratio dataset. The kinematic meanings of these units are also experimentally shown by using a human-like musculoskeletal leg robot.

  3. Experimental nuclear level densities and γ-ray strength functions in Sc and V isotopes

    International Nuclear Information System (INIS)

    Larsen, A. C.; Guttormsen, M.; Ingebretsen, F.; Messelt, S.; Rekstad, J.; Siem, S.; Syed, N. U. H.; Chankova, R.; Loennroth, T.; Schiller, A.; Voinov, A.

    2008-01-01

    The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract nuclear level density and γ-ray strength function from first-generation γ-ray spectra. This method is applied on the nuclei 44,45 Sc and 50,51 V in this work. The experimental level densities of 44,45 Sc are compared to calculated level densities using a microscopic model based on BCS quasiparticles within the Nilsson level scheme. The γ-ray strength functions are also compared to theoretical expectations, showing an unexpected enhancement of the γ-ray strength for low γ energies (E γ ≤3 MeV) in all the isotopes studied here. The physical origin of this enhancement is not yet understood

  4. 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.

  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. Vibrational and UV spectroscopic studies of 2-coumaranone by experimental and density functional theory calculations

    Science.gov (United States)

    Priya, Y. Sushma; Rao, K. Ramachandra; Chalapathi, P. V.; Satyavani, M.; Veeraiah, A.

    2017-09-01

    The vibrational and electronic properties of 2-coumaranone have been reported in the ground state using experimental techniques (FT-IR, FT-Raman, UV spectra and fluorescence microscopic imaging) and density functional theory (DFT) employing B3LYP correlation with the 6-31G(d, p) basis set. The theoretically reported optimized parameters, vibrational frequencies etc., were compared with the experimental values, which yielded good concurrence between the experimental and calculated values. The assignments of the vibrational spectra were done with the help of normal co-ordinate analysis (NCA) following the Scaled Quantum Mechanical Force Field(SQMFF) methodology. The whole assignments of fundamental modes were based on the potential energy distribution (PED) matrix. The electric dipole moment and the first order hyperpolarizability of the 2-coumaranone have been computed using quantum mechanical calculations. NBO and HOMO, LUMO analyses have been carried out. UV spectrum of 2-coumaranone was recorded in the region 100-300 nm and compared with the theoretical UV spectrum using TD-DFT and SAC-CI methods by which a good agreement is observed. Fluorescence microscopic imaging study reflects that the compound fluoresces in the green-yellow region.

  7. Which experimental model can sensitively indicate brain death by functional near-infrared spectroscopy?

    Science.gov (United States)

    Pan, Boan; Liu, Weichao; Fang, Xiang; Huang, Xiaobo; Li, Ting

    2018-02-01

    Brain death is defined as permanent loss of the brain functions. The evaluation of it has many meanings, such as the relief of organ transplantation stress and family burden. However, it is hard to be judged precisely. The standard clinical tests are expensive, time consuming and even dangerous, and some auxiliary methods have limitations. Functional near infrared spectroscopy (fNIRS), monitoring cerebral hemodynamic responses noninvasively, evaluate brain death in some papers published, but there is no discussion about which experimental mode can monitor brain death patient more sensitively. Here, we attempt to use our fNIRS to evaluate brain death and find which experimental mode is effective. In order to discuss the problem, we detected eleven brain death patients and twenty normal patients under natural state. They were provided different fraction of inspiration O2 (FIO2) in different phase. We found that the ratio of Δ[HbO2] (the concentration changes in oxyhemoglobin) to Δ[Hb] (the concentration changes in deoxyhemoglobin) in brain death patients is significantly higher than normal patients in FIO2 experiment. Combined with the data analysis result, restore oxygen change process and low-high-low paradigm is more sensitively.

  8. Crown-ether functionalized carbon nanotubes for purification of lithium compounds: computational and experimental study

    International Nuclear Information System (INIS)

    Singha Deb, A.K.; Arora, S.K.; Joshi, J.M.; Ali, Sk. M.; Shenoy, K.T.; Goyal, Aiana

    2015-01-01

    Lithium compounds finds several applications in nuclear science and technology, viz, lithium fluoride/hydroxide/alloys are used as dosimetric materials in luminescence devices, molten-salt breeder reactor, international thermonuclear experimental reactor, single crystal based neutron detectors etc. The lithium compounds should be in a proper state of purity; especially it should not contain other alkali metal cations which can downgrade the performance. Hence, there is a need to develop a process for purification of the lithium salt to achieve the desired quality. Therefore an attempt has been made to develop advanced nanomaterials for purification of the lithium salts. In this work, benzo-15-crown-5(B15C5) functionalized carbon nanotubes (CNTs), owing to the good adsorption properties of CNT and alkali metal encapsulation behaviour of B15C5, were showed to bind preferentially with sodium and potassium ions compared to lithium ions. DFT based computation calculations have shown that the free energy of complexation of Na + and K + by B15C5-CNT is higher than that of Li + , implying that B15C5-CNT selectively binds Na + and K + . The experimental batch solid-liquid extraction has also revealed the same trend as in the calculations. The crown-ethers functionalized CNTs have the potentiality for use in purifying lithium compounds. (author)

  9. 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.

  10. 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.

  11. 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

  12. Functional Magnetic Resonance Imaging of Rats with Experimental Autoimmune Encephalomyelitis Reveals Brain Cortex Remodeling

    Science.gov (United States)

    Tambalo, Stefano; Peruzzotti-Jametti, Luca; Rigolio, Roberta; Fiorini, Silvia; Bontempi, Pietro; Mallucci, Giulia; Balzarotti, Beatrice; Marmiroli, Paola; Sbarbati, Andrea; Cavaletti, Guido

    2015-01-01

    Cortical reorganization occurring in multiple sclerosis (MS) patients is thought to play a key role in limiting the effect of structural tissue damage. Conversely, its exhaustion may contribute to the irreversible disability that accumulates with disease progression. Several aspects of MS-related cortical reorganization, including the overall functional effect and likely modulation by therapies, still remain to be elucidated. The aim of this work was to assess the extent of functional cortical reorganization and its brain structural/pathological correlates in Dark Agouti rats with experimental autoimmune encephalomyelitis (EAE), a widely accepted preclinical model of chronic MS. Morphological and functional MRI (fMRI) were performed before disease induction and during the relapsing and chronic phases of EAE. During somatosensory stimulation of the right forepaw, fMRI demonstrated that cortical reorganization occurs in both relapsing and chronic phases of EAE with increased activated volume and decreased laterality index versus baseline values. Voxel-based morphometry demonstrated gray matter (GM) atrophy in the cerebral cortex, and both GM and white matter atrophy were assessed by ex vivo pathology of the sensorimotor cortex and corpus callosum. Neuroinflammation persisted in the relapsing and chronic phases, with dendritic spine density in the layer IV sensory neurons inversely correlating with the number of cluster of differentiation 45-positive inflammatory lesions. Our work provides an innovative experimental platform that may be pivotal for the comprehension of key mechanisms responsible for the accumulation of irreversible brain damage and for the development of innovative therapies to reduce disability in EAE/MS. SIGNIFICANCE STATEMENT Since the early 2000s, functional MRI (fMRI) has demonstrated profound modifications in the recruitment of cortical areas during motor, cognitive, and sensory tasks in multiple sclerosis (MS) patients. Experimental autoimmune

  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. A value-based, no-cost-to-patient health model in the developing world: Critical appraisal of a unique patient-centric neurosurgery unit.

    Science.gov (United States)

    Thakar, Sumit; Dadlani, Ravi; Sivaraju, Laxminadh; Aryan, Saritha; Mohan, Dilip; Sai Kiran, Narayanam Anantha; Rajarathnam, Ravikiran; Shyam, Maya; Sadanand, Venkatraman; Hegde, Alangar S

    2015-01-01

    It is well-accepted that the current healthcare scenario worldwide is due for a radical change, given that it is fraught with mounting costs and varying quality. Various modifications in health policies have been instituted toward this end. An alternative model, the low-cost, value-based health model, focuses on maximizing value for patients by moving away from a physician-centered, supply-driven system to a patient-centered system. The authors discuss the successful inception, functioning, sustainability, and replicability of a novel health model in neurosurgery built and sustained by inspired humanitarianism and that provides all treatment at no cost to the patients irrespective of their socioeconomic strata, color or creed. The Sri Sathya Sai Institute of Higher Medical Sciences (SSSIHMS) at Whitefield, Bengaluru, India, a private charitable hospital established in 2001, functions on the ideals of providing free state-of-the-art healthcare to all in a compassionate and holistic manner. With modern equipment and respectable outcome benchmarks, its neurosurgery unit has operated on around 18,000 patients since its inception, and as such, has contributed INR 5310 million (USD 88.5 million) to society from an economic standpoint. The inception and sustainability of the SSSIHMS model are based on self-perpetuating philanthropy, a cost-conscious culture and the dissemination of human values. Replicated worldwide, at least in the developing nations, this unique healthcare model may well change the face of healthcare economics.

  15. Evaluation of the impact of collaborative work by teams from the National Medical Residency Committee and the Brazilian Society of Neurosurgery. Retrospective and prospective study.

    Science.gov (United States)

    Santos, Renato Antunes Dos; Snell, Linda; Nunes, Maria do Patrocínio Tenório

    2016-04-01

    Training for specialist physicians in Brazil can take place in different ways. Closer liaison between institutions providing this training and assessment and health care services may improve qualifications. This article analyzes the impact of closer links and joint work by teams from the National Medical Residency Committee (Comissão Nacional de Residência Médica, CNRM) and the Brazilian Society of Neurosurgery (Sociedade Brasileira de Neurocirurgia, SBN) towards evaluating these programs. Retrospective and prospective study, conducted in a public university on a pilot project developed between CNRM and SBN for joint assessment of training programs across Brazil. The literature in the most relevant databases was reviewed. Documents and legislation produced by official government bodies were evaluated. Training locations were visited. Reports produced about residency programs were analyzed. Only 26% of the programs were immediately approved. The joint assessments found problems relating to teaching and to functioning of clinical service in 35% of the programs. The distribution of programs in this country has a strong relationship with the Human Development Index (HDI) of the regions and is very similar to the distribution of specialists. Closer collaboration between the SBN and CNRM had a positive impact on assessment of neurosurgery medical residency across the country. The low rates of direct approval have produced modifications and improvements to the quality of teaching and care (services). Closer links between the CNRM and other medical specialties have the capability to positively change the structure and function of specialty training in Brazil.

  16. Changes in Retinal Function and Cellular Remodeling Following Experimental Retinal Detachment in a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Tilda Barliya

    2017-01-01

    Full Text Available Purpose. To explore functional electroretinographic (ERG changes and associated cellular remodeling following experimental retinal detachment in a rabbit model. Methods. Retinal detachment was created in ten rabbits by injecting 0.1 ml balanced salt solution under the retina. Fundus imaging was performed 0, 3, 7, 14, and 21 days postoperatively. ERGs were recorded pre- and 7 and 21 days postoperatively. Eyes were harvested on day 21 and evaluated immunohistochemically (IHC for remodeling of second- and third-order neurons. Results. Retinal reattachment occurred within two weeks following surgery. No attenuation was observed in the photopic or scotopic a- and b-waves. A secondary wavefront on the descending slope of the scotopic b-wave was the only ERG result that was attenuated in detached retinas. IHC demonstrated anatomical changes in both ON and OFF bipolar cells. Bassoon staining was observed in the remodeled dendrites. Amacrine and horizontal cells did not alter, but Muller cells were clearly reactive with marked extension. Conclusion. Retinal detachment and reattachment were associated with functional and anatomical changes. Exploring the significance of the secondary scotopic wavefront and its association with the remodeling of 2nd- and 3rd-order neurons will shade more light on functional changes and recovery of the retina.

  17. The study on the immunity restoring function of cWPROL in treating experimental radiation esophagitis

    International Nuclear Information System (INIS)

    Shen Li; Shan Baoen; Zhang Li; Lu Fuhe; Guo Xiujuan

    2007-01-01

    Objective: To study the restorative function of compound white peony root oral liquids (cWPROL) in treating rats' experimental acute radiation-induced esophagitis from the aspect of immunodeficiency. Methods: 128 Wistar rats were divided into eight groups. The radiation esophagitis was induced by 43 Gy 60 Co. Then the rats were treated with medicine in different ways. On every experimental point the absolute number and percentage of T lymphocyte subsets were analyzed by flow cytometry. The changes of the leukocyte in number and differential count were detected by haemocyte counting instrument. IgG and C3 in rats' serum were analyzed by immunological turbidimetry. Results: Radiation brought on decrease of experimental rats 'leukocyte count, the lymphocyte differential count, absolute count and absolute T lymphocyte subsets in the blood and the content of IgG and C3 with radiation esophagitis. cWPROL could increase the lymphocyte percentage compared that in with the radiated group 2. The preventive (high dose) could increase lymphocyte count while Western medicine decreased rats' leukocyte count, lymphocyte percentage and absolute count (P<0.05). The absolute T lymphocyte subsets in rats' peripheral blood increased in the group infused with cWPROL (high dose) (P<0.001). Compared with the radiated group 2 the absolute T lymphocyte subsets decreased significantly(P<0.001), and the content of complement C3 increased in the group infused with cWPROL (high dose) (P<0.05) but decreased in the group infused with Western medicine (P<0.01). Conclusion: cWPROL plays the role of restoring the cytoimmunity and immunity damaged by radiation in rats with radiation esophagitis. (authors)

  18. An experimental investigation of the functional relationship between social phobia and cigarette smoking.

    Science.gov (United States)

    Dahne, Jennifer; Hise, Leanne; Brenner, Misha; Lejuez, C W; MacPherson, Laura

    2015-04-01

    Individuals with social phobia (SP) represent a large group with elevated rates of cigarette smoking and cessation rates lower than that of individuals without psychopathology. For individuals with SP, cigarette smoking may be used to reduce social anxiety in anticipation of and during social situations. However, no study to date has experimentally examined this association. The aim of the current study was to experimentally examine the relationship between cigarette smoking and SP as a function of induced social stress. We recruited daily smokers ages 18-21 who scored in either a clinical or normative range on the Social Interaction Anxiety Scale (SIAS). Participants included 54 smokers (42.6% female, 77.8% White, age M(SD)=19.65(1.18), CPSD M(SD)=7.67(4.36), 46.30% high SP) who attended two sessions: one social stress session and one neutral session. Results indicated that high SP smokers experienced significant decreases in negative affect (NA) following smoking a cigarette when experiencing social stress. This effect was specific to high SP smokers under social stress and was not observed among individuals' average in SP or when examining changes in positive affect. For individuals with SP, cigarette smoking may be maintained due to changes in NA associated with smoking specifically in the context of social stress. These results speak to the importance of targeted cessation interventions that address the nature of smoking for individuals with SP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Overview of experimental progress on understanding photon strength functions with an emphasis of the Oslo method

    Science.gov (United States)

    Krticka, Milan

    2015-10-01

    The so-called Photon Strength Functions (PSFs) for different multipolarities are, together with the Nuclear Level Density (NLD) the key entities describing the statistical γ-decay of nucleus. It is well known that PSFs at energies above the threshold for particle emission are well described by the Lorentzian shape of the Giant Electric Dipole Resonance (GEDR). On the other hand, shapes of RSFs at the low-energy tail of GEDR are known rather poorly. Information on the PSFs at the GEDR tail can be obtained from several different experimental techniques. They will be summarized and the most important ones briefly introduced in this contribution. Special emphasis will be put on the so-called Oslo method which allows simultaneous extraction of the NLD and the PSFs from particle- γ coincidence measurements. This method has been used for determining the NLD and the PSFs in many nuclei in A ~ 45- 240 range during past years. Examples of the most interesting results obtained with this method will be shown. The results will be compared to information on the PSFs available from other experimental techniques. The strengths and the weaknesses of the method will be thoroughly discussed.

  20. Experimental and clinical study on the digitalis in renal function disturbance

    International Nuclear Information System (INIS)

    Okubo, Mitsuru

    1977-01-01

    By using radioimmunoassay, movement of digoxin in the bodies of normal rabbits and dogs was discussed experimentally, and pathophysiology digoxin excretion in renal function disturbance was also discussed experimentally and clinically. The concentration of digoxin in each organ 30 minutes after intravenous administration of digoxin of 0.5 mg/kg to normal rabbits was the highest in the kidney, and it was high in order of skeletal muscles, ventricular muscles, and auricular muscles. A significant positive correlation was recognized between concentration of digoxin in blood and that in ventricular muscles. Digoxin clearance showed high values in normal dogs and dogs whose single kidney were extracted, when the concentration of digoxin in blood was low. A significant correlation between the concentration of digoxin in blood and BUN or creatinine was not recognized in patients with renal diseases, but a significant negative correlation between the concentration of digoxin in blood and creatinine clearance and between urinary excretion of digoxin and creatinine clearance was recognized. Therefore, creatinine clearance was thought to be useful for index to determine the administration dose of digoxin in renal dysfunction. In the patients who received external dialysis, decrease of the concentration of digoxin in blood after intravenous administration of digoxin delayed significantly in contrast to that of normal control group. (Tsunoda, M.)

  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. Tiny giants of gene regulation: experimental strategies for microRNA functional studies

    Science.gov (United States)

    Steinkraus, Bruno R.; Toegel, Markus

    2016-01-01

    The discovery over two decades ago of short regulatory microRNAs (miRNAs) has led to the inception of a vast biomedical research field dedicated to understanding these powerful orchestrators of gene expression. Here we aim to provide a comprehensive overview of the methods and techniques underpinning the experimental pipeline employed for exploratory miRNA studies in animals. Some of the greatest challenges in this field have been uncovering the identity of miRNA–target interactions and deciphering their significance with regard to particular physiological or pathological processes. These endeavors relied almost exclusively on the development of powerful research tools encompassing novel bioinformatics pipelines, high‐throughput target identification platforms, and functional target validation methodologies. Thus, in an unparalleled manner, the biomedical technology revolution unceasingly enhanced and refined our ability to dissect miRNA regulatory networks and understand their roles in vivo in the context of cells and organisms. Recurring motifs of target recognition have led to the creation of a large number of multifactorial bioinformatics analysis platforms, which have proved instrumental in guiding experimental miRNA studies. Subsequently, the need for discovery of miRNA–target binding events in vivo drove the emergence of a slew of high‐throughput multiplex strategies, which now provide a viable prospect for elucidating genome‐wide miRNA–target binding maps in a variety of cell types and tissues. Finally, deciphering the functional relevance of miRNA post‐transcriptional gene silencing under physiological conditions, prompted the evolution of a host of technologies enabling systemic manipulation of miRNA homeostasis as well as high‐precision interference with their direct, endogenous targets. WIREs Dev Biol 2016, 5:311–362. doi: 10.1002/wdev.223 For further resources related to this article, please visit the WIREs website. PMID:26950183

  3. Vorinostat, a histone deacetylase inhibitor, suppresses dendritic cell function and ameliorates experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Ge, Zhenzhen; Da, Yurong; Xue, Zhenyi; Zhang, Kai; Zhuang, Hao; Peng, Meiyu; Li, Yan; Li, Wen; Simard, Alain; Hao, Junwei; Yao, Zhi; Zhang, Rongxin

    2013-03-01

    Vorinostat, a histone deacetylase inhibitor, has been used clinically as an anticancer drug and also has immunosuppressive properties. However, the underlying mechanisms of effects of vorinostat on central nervous system (CNS) inflammatory diseases remain incomplete. Here, this study investigates the effects of vorinostat on human CD14(+) monocyte-derived dendritic cells (DCs) and mouse immature DC in vitro. Furthermore, we explore the therapeutic effects and cellular mechanisms of vorinostat on animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE) in vivo. Our findings demonstrate that vorinostat inhibited human CD14(+) monocyte-derived DCs differentiation, maturation, endocytosis, and further inhibited mDCs' stimulation of allogeneic T-cell proliferation. In addition, vorinostat inhibited DC-directed Th1- (Type 1T helper) and Th17-polarizing cytokine production. Furthermore, vorinostat ameliorated Th1- and Th17-mediated EAE by reducing CNS inflammation and demyelination. What's more, Th1 and Th17 cell functions were suppressed in vorinostat-treated EAE mice. Finally, vorinostat suppressed expression of costimulatory molecules of DC in EAE mice. These suggest therapeutic effects of vorinostat on EAE which may by suppress DCs and DCs-mediated Th1 and Th17 cell functions. Our findings warrant further investigation in the potential of vorinostat for the treatment of human multiple sclerosis. Copyright © 2012. Published by Elsevier Inc.

  4. Theoretical and Experimental Studies of Functionalized Carbon Nanotubes for Improved Thermal Conductivity

    Science.gov (United States)

    Kerr, Alexander; Burt, Timothy; Mullen, Kieran; Glatzhofer, Daniel; Houck, Matthew; Huang, Paul

    The use of carbon nanotubes (CNTs) to improve the thermal conductivity of composite materials is thwarted by their large thermal boundary resistance. We study how to overcome this Kapitza resistance by functionalizing CNTs with mixed molecular chains. Certain configurations of chains improve the transmission of thermal vibrations through our systems by decreasing phonon mismatch between the CNTs and their surrounding matrix. Through the calculation of vibrational normal modes and Green's functions, we develop a variety of computational metrics to compare the thermal conductivity (κ) of our systems. We show how different configurations of attached chains affect the samples' κ values by varying chain identity, chain length, number of chains, and heat driver behavior. We vary the parameters to maximize κ. To validate and optimize these metrics, we perform molecular dynamics simulations for comparison. We also present experimental results of composites enhanced with CNTs and make comparisons to the theory. We observe that some composites are thermally improved with the inclusion of CNTs, while others are scarcely changed, in agreement with theoretical models. This work was supported by NSF Grant DMR-1310407.

  5. Validation of the stream function method used for reconstruction of experimental ionospheric convection patterns

    Directory of Open Access Journals (Sweden)

    P.L. Israelevich

    Full Text Available In this study we test a stream function method suggested by Israelevich and Ershkovich for instantaneous reconstruction of global, high-latitude ionospheric convection patterns from a limited set of experimental observations, namely, from the electric field or ion drift velocity vector measurements taken along two polar satellite orbits only. These two satellite passes subdivide the polar cap into several adjacent areas. Measured electric fields or ion drifts can be considered as boundary conditions (together with the zero electric potential condition at the low-latitude boundary for those areas, and the entire ionospheric convection pattern can be reconstructed as a solution of the boundary value problem for the stream function without any preliminary information on ionospheric conductivities. In order to validate the stream function method, we utilized the IZMIRAN electrodynamic model (IZMEM recently calibrated by the DMSP ionospheric electrostatic potential observations. For the sake of simplicity, we took the modeled electric fields along the noon-midnight and dawn-dusk meridians as the boundary conditions. Then, the solution(s of the boundary value problem (i.e., a reconstructed potential distribution over the entire polar region is compared with the original IZMEM/DMSP electric potential distribution(s, as well as with the various cross cuts of the polar cap. It is found that reconstructed convection patterns are in good agreement with the original modelled patterns in both the northern and southern polar caps. The analysis is carried out for the winter and summer conditions, as well as for a number of configurations of the interplanetary magnetic field.

    Key words: Ionosphere (electric fields and currents; plasma convection; modelling and forecasting

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

    International Nuclear Information System (INIS)

    Schiaveto-de-Souza, A.; Silva, C.A. da; Defino, H.L.A.; Bel, E.A.Del

    2013-01-01

    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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Effect of Cistanche Desertica Polysaccharides on Learning and Memory Functions and Ultrastructure of Cerebral Neurons in Experimental Aging Mice

    Institute of Scientific and Technical Information of China (English)

    孙云; 邓杨梅; 王德俊; 沈春锋; 刘晓梅; 张洪泉

    2001-01-01

    To observe the effects of Cistanche desertica polysaccharides (CDP) on the learning and memory functions and cerebral ultrastructure in experimental aging mice. Methods: CDP was administrated intragastrically 50 or 100 mg/kg per day for 64 successive days to experimental aging model mice induced by D-galactose, then the learning and memory functions of mice were estimated by step-down test and Y-maze test; organelles of brain tissue and cerebral ultrastructure were observed by transmission electron microscope and physical strength was determined by swimming test. Results: CDP could obviously enhance the learning and memory functions (P<0.01) and prolong the swimming time (P<0.05), decrease the number of lipofuscin and slow down the degeneration of mitochondria in neurons(P<0.05), and improve the degeneration of cerebral ultra-structure in aging mice. Conclusion: CDP could improve the impaired physiological function and alleviate cerebral morphological change in experimental aging mice.

  12. 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.

  13. Surgical site infections after elective neurosurgery: a survey of 1747 patients.

    Science.gov (United States)

    Valentini, Laura G; Casali, Cecilia; Chatenoud, Liliane; Chiaffarino, Francesca; Uberti-Foppa, Caterina; Broggi, Giovanni

    2008-01-01

    To evaluate the incidence and risk factors of postsurgical site infections (SSIs) in elective neurosurgical procedures in patients treated with an ultrashort antibiotic protocol. In this consecutive series of 1747 patients treated with elective neurosurgery and ultrashort prophylactic antibiotic therapy at the Fondazione Istituto Nazionale Neurologico "Carlo Besta" in Milan, the rate of SSIs was 0.7% (13 patients). When only clean neurosurgery was considered, there were 11 such SSIs (1.52%) in 726 craniotomies and one SSI (0.15) in 663 spinal operations. The antibiotic protocol was prolonged in every case of external communication as cerebrospinal fluid leaks or external drainages. The infection rate of the whole series was low (0.72%), and a risk factor identified for SSIs in clean neurosurgery was longer surgery duration. The relative risk estimate was 12.6 for surgeries lasting 2 hours and 24.3 for surgeries lasting 3 or more hours. Patients aged older than 50 years had a lower risk of developing SSI with a relative risk of 0.23 when compared with patients aged younger than 50 years. The present series reports a low incidence of SSIs for elective neurosurgery, even for high-risk complex craniotomies performed for tumor removal. Given that an antibiotic protocol prolongation was used to pretreat any early signs of infection and external communication, the protocol was appropriate for the case mix. The two identified risk factors (surgical duration > 2 hours and middle-aged patients [16-50 yr]) may be indicators of other factors, such as the level of surgical complexity and poor neurological outcome.

  14. Free-access open-source e-learning in comprehensive neurosurgery skills training.

    Science.gov (United States)

    Jotwani, Payal; Srivastav, Vinkle; Tripathi, Manjul; Deo, Rama Chandra; Baby, Britty; Damodaran, Natesan; Singh, Ramandeep; Suri, Ashish; Bettag, Martin; Roy, Tara Sankar; Busert, Christoph; Mehlitz, Marcus; Lalwani, Sanjeev; Garg, Kanwaljeet; Paul, Kolin; Prasad, Sanjiva; Banerjee, Subhashis; Kalra, Prem; Kumar, Subodh; Sharma, Bhavani Shankar; Mahapatra, Ashok Kumar

    2014-01-01

    Since the end of last century, technology has taken a front seat in dispersion of medical education. Advancements of technology in neurosurgery and traditional training methods are now being challenged by legal and ethical concerns of patient safety, resident work-hour restriction and cost of operating-room time. To supplement the existing neurosurgery education pattern, various e-learning platforms are introduced as structured, interactive learning system. This study focuses on the concept, formulation, development and impact of web based learning platforms dedicated to neurosurgery discipline to disseminate education, supplement surgical knowledge and improve skills of neurosurgeons. 'Neurosurgery Education and Training School (NETS), e-learning platform' has integration of web-based technologies like 'Content Management System' for organizing the education material and 'Learning Management System' for updating neurosurgeons. NETS discussion forum networks neurosurgeons, neuroscientists and neuro-technologists across the globe facilitating collaborative translational research. Multi-authored neurosurgical e-learning material supplements the deficiencies of regular time-bound education. Interactive open-source, global, free-access e-learning platform of NETS has around 1) 425 visitors/month from 73 countries; ratio of new visitors to returning visitors 42.3; 57.7 (2); 64,380 views from 190 subscribers for surgical videos, 3-D animation, graphics based training modules (3); average 402 views per post. The e-Learning platforms provide updated educational content that make them "quick, surf, find and extract" resources. e-Learning tools like web-based education, social interactive platform and question-answer forum will save unnecessary expenditure of time and travel of neurosurgeons seeking knowledge. The need for free access platforms is more pronounced for the neurosurgeons and patients in developing nations.

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

    Directory of Open Access Journals (Sweden)

    Faiza A. Qari

    2016-02-01

    Full Text Available Objectives: 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. Methods: 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. Results: 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. Conclusion: 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.

  16. 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.

  17. Medical Department, United States Army. Surgery in World War 2. Neurosurgery. Volume 2

    Science.gov (United States)

    1959-01-01

    extension, without respect for such anatonlic barriers as fascia , peri- osteuni, or the serosal mnenmbranes or the capsules of viscera. T[ie appearance...NEUROSURGERY a bilateral atypical plantar response was obtained in complete lesions, in the form of a delayed, weak, slow, vermicular type of plantar ...wound after closure of the dura, and closure was effected in layers. Because this was a re- opened wound, a slip drain was left beneath the fascia for

  18. 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

  19. The Establishment and Development of Neurosurgery Services in Papua New Guinea.

    Science.gov (United States)

    Kaptigau, W Matui; Rosenfeld, Jeffrey V; Kevau, Ikau; Watters, David A

    2016-02-01

    Papua New Guinea (PNG) is a developing Pacific Nation of 7.3 million people. Although neurosurgery training was introduced to PNG in the year 2000, it was in 2003 that a neurosurgery service was established. Prior to this time, neurosurgery in PNG was performed by general surgeons, with some assistance from visiting Australian neurosurgeons. Neurosurgical training was introduced to PNG in 2000. The model involved a further 3 years of training for a surgeon who had already completed 4 years of general surgical training. We aim to review the output, outcomes and impact achieved by training the first national neurosurgeon. The data on activity (output) and outcomes were collected prospectively from 2003–2012. Ongoing mentoring and continuing professional development were provided through annual neurosurgical visits from Australia. There were serious limitations in the provision of equipment, with a lack of computerized tomographic or MR imaging, and adjuvant oncological services. There were 1618 neurosurgery admissions, 1020 neurosurgical procedures with a 5.74 % overall mortality. Seventy percent of cases presented as emergencies. There were improved outcomes, particularly for head injuries, whilst hydrocephalus was managed with an acceptable morbidity and revision rate. The training of a neurosurgeon resulted in PNG patients receiving a better range of surgical services, with a lower mortality. The outcomes able to be delivered were limited by late presentations of patients and lack of resources including imaging. These themes are familiar to all low- and middle-income countries (LMICs) and this may serve as a model for other LMIC neurosurgical services to adopt as they consider whether to establish and develop neurosurgical and other sub-specialist surgical services.

  20. Neurosurgery in Egypt: past, present, and future-from pyramids to radiosurgery.

    Science.gov (United States)

    El Gindi, Sayed

    2002-09-01

    THE CONTEMPORARY DEVELOPMENT of neurosurgery in Egypt is described, with reference to the ancient past and recent American and European influences. This article traces the steps taken by several leading Egyptian pioneers. Egypt, one of the key countries in the Middle East, has led the development of the specialty in the region and has maintained close ties with the international body of neurological surgeons and surgical societies.

  1. 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

  2. The Richard C. Schneider Lecture. New dimensions of neurosurgery in the realm of high technology: possibilities, practicalities, realities.

    Science.gov (United States)

    Apuzzo, M L

    1996-04-01

    Fueled by a buoyant economy, popular attitudes and demands, and parallel progress in transferable technical and biological areas, neurosurgery has enjoyed a remarkable quarter of a century of progress. Developmental trends in the discipline have included the following: 1) a refinement of preoperative definition of the structural substrate, 2) miniaturization of operative corridors, 3) reduction of operative trauma, 4) increased effectiveness at the target site, and 5) incorporation of improved technical adjuvants and physical operative tools into treatment protocols. In particular, the computer has become a formidable ally in diagnostic and surgical events. Trends in technical development indicate that we are entering an exciting era of advanced surgery of the human cerebrum, which is heralded by the following: 1) current developments in areas of imaging, sensors, and visualization; 2) new devices for localization and navigation; 3) new capabilities for action at the target point; and 4) innovative concepts related to advanced operative venues. Imaging has provided structurally based surgical maps, which now are being given the new dimension of function in complex and integrated formats for preoperative planning and intraoperative tactical direction. Cerebral localization and navigation based on these advances promise to provide further refinement to the field of stereotactic neurosurgery, as linked systems are superseded by more flexible nonlinked methodologies in functionally defined volume-oriented navigational databases. Target point action now includes not only ablative capabilities through micro-operative methods and the use of stereotactically directed high-energy forms but also the emergence of restorative capabilities through applications of principles of genetic engineering in the areas of molecular and cellular neurosurgery. Complex, dedicated, and self-contained operative venues will be required to optimize the emergence and development of these

  3. 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.

  4. Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

    Science.gov (United States)

    Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

    2012-01-01

    AIM: To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. METHODS: Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway. PMID:22912548

  5. Experimental demonstrations of all-optical networking functions for WDM optical networks

    Science.gov (United States)

    Gurkan, Deniz

    The deployment of optical networks will enable high capacity links between users but will introduce the problems associated with transporting and managing more channels. Many network functions should be implemented in optical domain; main reasons are: to avoid electronic processing bottlenecks, to achieve data-format and data-rate independence, to provide reliable and cost efficient control and management information, to simultaneously process multiple wavelength channel operation for wavelength division multiplexed (WDM) optical networks. The following novel experimental demonstrations of network functions in the optical domain are presented: Variable-bit-rate recognition of the header information in a data packet. The technique is reconfigurable for different header sequences and uses optical correlators as look-up tables. The header is processed and a signal is sent to the switch for a series of incoming data packets at 155 Mb/s, 622 Mb/s, and 2.5 Gb/s in a reconfigurable network. Simultaneous optical time-slot-interchange and wavelength conversion of the bits in a 2.5-Gb/s data stream to achieve a reconfigurable time/wavelength switch. The technique uses difference-frequency-generation (DFG) for wavelength conversion and fiber Bragg gratings (FBG) as wavelength-dependent optical time buffers. The WDM header recognition module simultaneously recognizing two header bits on each of two 2.5-Gbit/s WDM packet streams. The module is tunable to enable reconfigurable look-up tables. Simultaneous and independent label swapping and wavelength conversion of two WDM channels for a multi-protocol label switching (MPLS) network. Demonstration of label swapping of distinct 8-bit-long labels for two WDM data channels is presented. Two-dimensional code conversion module for an optical code-division multiple-access (O-CDMA) local area network (LAN) system. Simultaneous wavelength conversion and time shifting is achieved to enable flexible code conversion and increase code re

  6. Analysis of left ventricular function of the mouse heart during experimentally induced hyperthyroidism and recovery.

    Science.gov (United States)

    Hübner, Neele Saskia; Merkle, Annette; Jung, Bernd; von Elverfeldt, Dominik; Harsan, Laura-Adela

    2015-01-01

    Many of the clinical manifestations of hyperthyroidism are due to the ability of thyroid hormones to alter myocardial contractility and cardiovascular hemodynamics, leading to cardiovascular impairment. In contrast, recent studies highlight also the potential beneficial effects of thyroid hormone administration for clinical or preclinical treatment of different diseases such as atherosclerosis, obesity and diabetes or as a new therapeutic approach in demyelinating disorders. In these contexts and in the view of developing thyroid hormone-based therapeutic strategies, it is, however, important to analyze undesirable secondary effects on the heart. Animal models of experimentally induced hyperthyroidism therefore represent important tools for investigating and monitoring changes of cardiac function. In our present study we use high-field cardiac MRI to monitor and follow-up longitudinally the effects of prolonged thyroid hormone (triiodothyronine) administration focusing on murine left ventricular function. Using a 9.4 T small horizontal bore animal scanner, cinematographic MRI was used to analyze changes in ejection fraction, wall thickening, systolic index and fractional shortening. Cardiac MRI investigations were performed after sustained cycles of triiodothyronine administration and treatment arrest in adolescent (8 week old) and adult (24 week old) female C57Bl/6 N mice. Triiodothyronine supplementation of 3 weeks led to an impairment of cardiac performance with a decline in ejection fraction, wall thickening, systolic index and fractional shortening in both age groups but with a higher extent in the group of adolescent mice. However, after a hormonal treatment cessation of 3 weeks, only young mice are able to partly restore cardiac performance in contrast to adult mice lacking this recovery potential and therefore indicating a presence of chronically developed heart pathology. Copyright © 2014 John Wiley & Sons, Ltd.

  7. 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

  8. Experimental study on p-wave neutron strength functions for light nuclei

    International Nuclear Information System (INIS)

    Koester, L.; Waschkowski, W.; Meier, J.; Rau, G.; Salehi, M.

    1988-01-01

    Broad energy distributions in fast neutron beams have been achieved by appropriate filtering of the 236 U fission radiation provided from the RENT converter facility at the FRM research reactor. Transmission measurements in such beams result in average cross sections to which resonance reactions and shape elastic scattering contribute. We used a silicon (124.5 cm) filtered beam with a median energy of 143 keV (width 20 keV) and beams with 1.3 MeV (0.55 to 3 MeV) and 2.1 MeV (1 to 5.5 MeV) obtained through different filter combinations of lead and polyethylene. The relative high energies and the broad spectra made it possible to determine experimentally the contributions of s- and p-wave resonance reactions to the average cross section even for light nuclei. Using the three different beams we determined the average cross sections for the elements in the mass region A = 9 to 65. Analysing the measured cross sections by means of the R matrix formalism provided a complete set of p-wave strength functions and distant level parameters. Moreover, single particle shell effects in the cross sections were observed. In conclusion we obtained information on the 2P and the 3S size resonances and about the validity of the optical model for neutron reactions with light nuclei. (orig.)

  9. Vibration Prediction Method of Electric Machines by using Experimental Transfer Function and Magnetostatic Finite Element Analysis

    International Nuclear Information System (INIS)

    Saito, A; Kuroishi, M; Nakai, H

    2016-01-01

    This paper concerns the noise and structural vibration caused by rotating electric machines. Special attention is given to the magnetic-force induced vibration response of interior-permanent magnet machines. In general, to accurately predict and control the vibration response caused by the electric machines, it is inevitable to model not only the magnetic force induced by the fluctuation of magnetic fields, but also the structural dynamic characteristics of the electric machines and surrounding structural components. However, due to complicated boundary conditions and material properties of the components, such as laminated magnetic cores and varnished windings, it has been a challenge to compute accurate vibration response caused by the electric machines even after their physical models are available. In this paper, we propose a highly-accurate vibration prediction method that couples experimentally-obtained discrete structural transfer functions and numerically-obtained distributed magnetic-forces. The proposed vibration synthesis methodology has been applied to predict vibration responses of an interior permanent magnet machine. The results show that the predicted vibration response of the electric machine agrees very well with the measured vibration response for several load conditions, for wide frequency ranges. (paper)

  10. 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

  11. Vascular morphologic and functional effect of endogenous androgens in an experimental atherosclerotic rabbits model

    International Nuclear Information System (INIS)

    Echeverry, Dario; Delgadillo, Alexandra; Montes, Felix

    2007-01-01

    Previous clinical and experimental studies suggest that androgens could have adverse, neutral or beneficial effect on atherosclerosis and its clinical manifestations. Methods: an experimental, randomized controlled study in 40 New Zeland white male rabbits was realized. 20 rabbits underwent orchidectomy and 20 were fed with an atherogenic diet for 20 weeks. These were distributed in four groups: 1. non-castrated under normal diet, 2. Castrated under normal diet, 3. non-castrated under atherogenic diet, and 4. Castrated under atherogenic diet. Total cholesterol and free testosterone were measured. After euthanasia, arterial relaxation independent of endothelium was quantified in aorta, as well as the one depending on endothelium, in vitro, and histomorphometric analysis of thoracic aorta were made in order to quantify the atherosclerotic plaque formation. Results: animals that had a normal diet (n=20) had total cholesterol of 51.1 ± 8.5 mg/dl and those with atherogenic diet of 429.2 ± 262.0 mg/dl (p< 0.001). Testosterone levels in the non- castrated group were 2.1 ± 0.3 ng/ml and in the castrated were 0.8 ± 0.4 ng/ml (p= 0.024). In non-castrated rabbits the effect of hypercholesterolemia (366 ± 226.1 mg/dl) inducing atherosclerotic plaque and functional vascular alteration was mild. On the other hand, atherogenic diet in castrated rabbits induced an increment in total cholesterol from 387.6 ± 292.7 mg/dl (p <0.001) and severe morphological changes such as plaque area 2.6 ± 2.3mm (p <0.001), vessel plaque/area 0.25 ± 0.1 (p <0.001) and area index of plaque/area of the media 0.4 ± 0.3 (p <0.001). Endothelium independent relaxation percentage was 85.5 ± 14.3% (p = NS) and endothelium dependent relaxation was 38.5 ± 201% (p = 0.03). Conclusion: This study realized in rabbits demonstrates that endogenous testosterone might have a preventive effect on atherosclerosis and favor endothelium dependent vascular relaxation in the presence of severe

  12. An experimental investigation of the consequences and social functions of fat talk in friendship groups.

    Science.gov (United States)

    Cruwys, Tegan; Leverington, Carly T; Sheldon, Anne M

    2016-01-01

    Fat talk is a form of self-degrading, thin-ideal endorsing communication that occurs within female friendship groups. Previous studies have suggested negative associations with wellbeing, but have been predominantly correlational and based on self-report. This study aimed to assess the causal relationship between fat talk and the correlates of disordered eating (thin-ideal internalization, body dissatisfaction, negative affect, and dieting intentions) by experimentally manipulating fat talk in existing friendship groups and measuring naturalistic expression of fat talk and its effects. Participants were 85 women aged 17-25 who completed the experiment in friendship pairs. They were randomly assigned to a condition in which their friend expressed fat talk, positive body talk, or neutral talk. This study found evidence of a causal link between listening to friends fat talk and increased correlates of disordered eating. The negative effects of listening to fat talk were fully mediated by fat talk expression. This study also revealed a social function of fat talk, whereby participants rated their friends more positively when they were perceived to behave consistently with group norms, either pro- or anti-fat talk. Positive body talk showed none of the negative effects of fat talk, and was considered socially acceptable regardless of existing friendship group norms. These findings indicate that fat talk is a mechanism through which the thin ideal is transmitted between individuals. Interventions at the level of the friendship group to challenge norms and communication styles may break the link between societal risk factors and individual risk of eating disorders. © 2015 Wiley Periodicals, Inc.

  13. Acquiring molecular interference functions of X-ray coherent scattering for breast tissues by combination of simulation and experimental methods

    International Nuclear Information System (INIS)

    Chaparian, A.; Oghabian, M. A.; Changizi, V.

    2009-01-01

    Recently, it has been indicated that X-ray coherent scatter from biological tissues can be used to access signature of tissue. Some scientists are interested in studying this effect to get early detection of breast cancer. Since experimental methods for optimization are time consuming and expensive, some scientists suggest using simulation. Monte Carlo codes are the best option for radiation simulation: however, one permanent defect with Monte Carlo codes has been the lack of a sufficient physical model for coherent (Rayleigh) scattering, including molecular interference effects. Materials and Methods: It was decided to obtain molecular interference functions of coherent X-ray scattering for normal breast tissues by combination of modeling and experimental methods. A Monte Carlo simulation program was written to simulate the angular distribution of scattered photons for the normal breast tissue samples. Moreover, experimental diffraction patterns of these tissues were measured by means of energy dispersive X-ray diffraction method. The simulation and experimental data were used to obtain a tabulation of molecular interference functions for breast tissues. Results: With this study a tabulation of molecular interference functions for normal breast tissues Was prepared to facilitate the simulation diffraction patterns of the tissues without any experimental. Conclusion: The method may lead to design new systems for early detection of breast cancer.

  14. 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.

  15. 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

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Letaif, Olavo Biraghi; Cristante, Alexandre Fogaça; Barros Filho, Tarcísio Eloy Pessoa de; Ferreira, Ricardo; Santos, Gustavo Bispo dos; Rocha, Ivan Dias da; Marcon, Raphael Martus

    2015-10-01

    To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion. 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. 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. Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury.

  19. White matter mapping by DTI-based tractography for neurosurgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2009-01-01

    To validate the corticospinal tract (CST) and arcuate fasciculus (AF) illustrated by diffusion tensor imaging (DTI), we used CST- and AF-tractography integrated neuronavigation and monopolar and bipolar direct fiber stimulation. Forty seven patients with brain lesions adjacent to the CST and AF were studied. During lesion resection, direct fiber stimulation was applied to the CST and AF to elicit motor responses (fiber-motor evoked potential (MEP)) and the impairment of language-related functions to identify the CST and AF. The minimum distance between the resection border and illustrated CST was measured on postoperative images. Direct fiber stimulation demonstrated that CST- and AF-tractography accurately reflected anatomical CST functioning. The cortical stimulation to the gyrus, including the language-functional MRI (fMRI) activation, evoked speech arrest, while the subcortical stimulation close to the AF reproducibly caused 'paranomia' without speech arrest. There were strong correlations between stimulus intensity for the fiber-MEP and the distance between eloquent fibers and the stimulus points. The convergent calculation formulated 1.8 mA as the electrical threshold of CST for the fiber-MEP, which was much smaller than that of the hand motor area. Validated tractography demonstrated the mean distance and intersection angle between CST and AF were 5 mm and 107 deg, respectively. In addition, the anisotropic diffusion-weighted image (ADWI) and CST-tractography clearly indicated the locations of the primary motor area (PMA) and the central sulcus and well reflected the anatomical characteristics of the corticospinal tract in the human brain. DTI-based tractography is a reliable way to map the white matter connections in the entire brain in clinical and basic neuroscience. By combining these techniques, investigating the cortico-subcortical connections in the human central nervous system could contribute to elucidating the neural networks of the human brain and

  20. Connectome analysis for pre-operative brain mapping in neurosurgery

    Science.gov (United States)

    Hart, Michael G.; Price, Stephen J.; Suckling, John

    2016-01-01

    Abstract Object: Brain mapping has entered a new era focusing on complex network connectivity. Central to this is the search for the connectome or the brains ‘wiring diagram’. Graph theory analysis of the connectome allows understanding of the importance of regions to network function, and the consequences of their impairment or excision. Our goal was to apply connectome analysis in patients with brain tumours to characterise overall network topology and individual patterns of connectivity alterations. Methods: Resting-state functional MRI data were acquired using multi-echo, echo planar imaging pre-operatively from five participants each with a right temporal–parietal–occipital glioblastoma. Complex networks analysis was initiated by parcellating the brain into anatomically regions amongst which connections were identified by retaining the most significant correlations between the respective wavelet decomposed time-series. Results: Key characteristics of complex networks described in healthy controls were preserved in these patients, including ubiquitous small world organization. An exponentially truncated power law fit to the degree distribution predicted findings of general network robustness to injury but with a core of hubs exhibiting disproportionate vulnerability. Tumours produced a consistent reduction in local and long-range connectivity with distinct patterns of connection loss depending on lesion location. Conclusions: Connectome analysis is a feasible and novel approach to brain mapping in individual patients with brain tumours. Applications to pre-surgical planning include identifying regions critical to network function that should be preserved and visualising connections at risk from tumour resection. In the future one could use such data to model functional plasticity and recovery of cognitive deficits. PMID:27447756

  1. Connectome analysis for pre-operative brain mapping in neurosurgery.

    Science.gov (United States)

    Hart, Michael G; Price, Stephen J; Suckling, John

    2016-10-01

    Brain mapping has entered a new era focusing on complex network connectivity. Central to this is the search for the connectome or the brains 'wiring diagram'. Graph theory analysis of the connectome allows understanding of the importance of regions to network function, and the consequences of their impairment or excision. Our goal was to apply connectome analysis in patients with brain tumours to characterise overall network topology and individual patterns of connectivity alterations. Resting-state functional MRI data were acquired using multi-echo, echo planar imaging pre-operatively from five participants each with a right temporal-parietal-occipital glioblastoma. Complex networks analysis was initiated by parcellating the brain into anatomically regions amongst which connections were identified by retaining the most significant correlations between the respective wavelet decomposed time-series. Key characteristics of complex networks described in healthy controls were preserved in these patients, including ubiquitous small world organization. An exponentially truncated power law fit to the degree distribution predicted findings of general network robustness to injury but with a core of hubs exhibiting disproportionate vulnerability. Tumours produced a consistent reduction in local and long-range connectivity with distinct patterns of connection loss depending on lesion location. Connectome analysis is a feasible and novel approach to brain mapping in individual patients with brain tumours. Applications to pre-surgical planning include identifying regions critical to network function that should be preserved and visualising connections at risk from tumour resection. In the future one could use such data to model functional plasticity and recovery of cognitive deficits.

  2. Power and power-to-flow reactivity transfer functions in EBR-II [Experimental Breeder Reactor II] fuel

    International Nuclear Information System (INIS)

    Grimm, K.N.; Meneghetti, D.

    1989-01-01

    Reactivity transfer functions are important in determining the reactivity history during a power transient. Overall nodal transfer functions have been calculated for different subassembly types in the Experimental Breeder Reactor II (EBR-II). Steady-state calculations for temperature changes and, hence, reactivities for power changes have been separated into power and power-to-flow-dependent terms. Axial nodal transfer functions separated into power and power-to-flow-dependent components are reported in this paper for a typical EBR-II fuel pin. This provides an improved understanding of the time dependence of these components in transient situations

  3. 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.

  4. Experimental tests of the properties of the quantum mechanical wave function

    International Nuclear Information System (INIS)

    Tarozzi, G.

    1985-01-01

    A new experimental proposal on the wave-particle dualism is discussed, unifying the two different classes of experiments recently advanced to detect the physical properties of quantum waves of producing interference or stimulated emission

  5. MIDAS. An algorithm for the extraction of modal information from experimentally determined transfer functions

    International Nuclear Information System (INIS)

    Durrans, R.F.

    1978-12-01

    In order to design reactor structures to withstand the large flow and acoustic forces present it is necessary to know something of their dynamic properties. In many cases these properties cannot be predicted theoretically and it is necessary to determine them experimentally. The algorithm MIDAS (Modal Identification for the Dynamic Analysis of Structures) which has been developed at B.N.L. for extracting these structural properties from experimental data is described. (author)

  6. White matter mapping by DTI-based tractography for neurosurgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2011-01-01

    The purpose of this study was to validate the corticospinal tract (CST) and arcuate fasciculus (AF) illustrated by diffusion tensor imaging (DTI), we used CST- and AF-tractography integrated neuronavigation and monopolar and bipolar direct fiber stimulation. Forty seven patients with brain lesions adjacent to the CST and AF were studied. During lesion resection, direct fiber stimulation was applied to the CST and AF to elicit motor responses (fiber-MEP) and the impairment of language-related functions to identify the CST and AF. The minimum distance between the resection border and illustrated CST was measured on postoperative images. Direct fiber stimulation demonstrated that CST- and AF-tractography accurately reflected anatomical CST functioning. The cortical stimulation to the gyrus, including the language-fMRI activation, evoked speech arrest, while the subcortical stimulation close to the AF reproducibly caused 'paranomia' without speech arrest. There were strong correlations between stimulus intensity for the fiber-MEP and the distance between eloquent fibers and the stimulus points. The convergent calculation formulated 1.8 mA as the electrical threshold of CST for the fiber-MEP, which was much smaller than that of the hand motor area. Validated tractography demonstrated the mean distance and intersection angle between CST and AF were 5 mm and 107 deg, respectively. In addition, the anisotropic diffusion-weighted image (ADWI) and CST-tractography clearly indicated the locations of the primary motor area (PMA) and the central sulcus and well reflected the anatomical characteristics of the corticospinal tract in the human brain. DTI-based tractography is a reliable way to map the white matter connections in the entire brain in clinical and basic neuroscience. By combining these techniques, investigating the cortico-subcortical connections in the human central nervous system could contribute to elucidating the neural networks of the human brain and shed light

  7. Effect of Ganfukang on liver function and serum hepatic fibrosis markers levels in SD rats with experimental hepatic fibrosis

    International Nuclear Information System (INIS)

    Che Ying; Wang Shanju; Xu Tingting; Jiang Miaona; Jia Yujie

    2004-01-01

    Objective: To observe the effect of Ganfukang on liver function and serum hepatic fibrosis markers levels in SD rats with experimental hepatic fibrosis. Methods: SD rat models of liver fibrosis was induced by CCl 4 (n=57). Liver function (GPT, GOT) and serum hepatic fibrosis markers levels (HA, LN, C-IV, PC-III, with RIA) were tested in these models and 10 control rats. Eleven model rats were left untreated, the others were treated with Ganfukang of different concentrations and the above hepatic parameters were again determined after completion of treatment. Results: Lever function was much deteriorated and serum markers levels significantly increased in the model rats (vs controls, P<0.01). After treatment with Ganfukang, the improvement was significant (vs untreated models, P<0.01). Conclusion: Ganfukang is of definite therapeutic value for experimental hepatic fibrosis in rat models. (authors)

  8. 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

  9. Incidence of Postoperative Hematomas Requiring Surgical Treatment in Neurosurgery: A Retrospective Observational Study.

    Science.gov (United States)

    Lillemäe, Kadri; Järviö, Johanna Annika; Silvasti-Lundell, Marja Kaarina; Antinheimo, Jussi Juha-Pekka; Hernesniemi, Juha Antero; Niemi, Tomi Tapio

    2017-12-01

    We aimed to characterize the occurrence of postoperative hematoma (POH) after neurosurgery overall and according to procedure type and describe the prevalence of possible confounders. Patient data between 2010 and 2012 at the Department of Neurosurgery in Helsinki University Hospital were retrospectively analyzed. A data search was performed according to the type of surgery including craniotomies; shunt procedures, spine surgery, and spinal cord stimulator implantation. We analyzed basic preoperative characteristics, as well as data about the initial intervention, perioperative period, revision operation and neurologic recovery (after craniotomy only). The overall incidence of POH requiring reoperation was 0.6% (n = 56/8783) to 0.6% (n = 26/4726) after craniotomy, 0% (n = 0/928) after shunting procedure, 1.1% (n = 30/2870) after spine surgery, and 0% (n = 0/259) after implantation of a spinal cord stimulator. Craniotomy types with higher POH incidence were decompressive craniectomy (7.9%, n = 7/89), cranioplasty (3.6%, n = 4/112), bypass surgery (1.7%, n = 1/60), and epidural hematoma evacuation (1.6%, n = 1/64). After spinal surgery, POH was observed in 1.1% of cervical and 2.1% of thoracolumbar operations, whereas 46.7% were multilevel procedures. 64.3% of patients with POH and 84.6% of patients undergoing craniotomy had postoperative hypertension (systolic blood pressure >160 mm Hg or lower if indicated). Poor outcome (Glasgow Outcome Scale score 1-3), whereas death at 6 months after craniotomy was detected in 40.9% and 21.7%. respectively, of patients with POH who underwent craniotomy. POH after neurosurgery was rare in this series but was associated with poor outcome. Identification of risk factors of bleeding, and avoiding them, if possible, might decrease the incidence of POH. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. State of Global Pediatric Neurosurgery Outreach: Survey by the International Education Subcommittee

    Science.gov (United States)

    Davis, Matthew C.; Rocque, Brandon G.; Singhal, Ash; Ridder, Tom; Pattisapu, Jogi V.; Johnston, James M.

    2017-01-01

    Object Neurosurgical services are increasingly recognized as essential components of surgical care worldwide. Degree of interest among neurosurgeons regarding international work, and barriers to involvement in global neurosurgical outreach, are largely unexplored. We distributed a survey to members of the AANS/CNS Joint Section on Pediatric Neurosurgery to assess the state of global outreach among its members and identify barriers to involvement. Methods An internet-based questionnaire was developed by the International Education Subcommittee of the AANS/CNS Joint Section on Pediatric Neurosurgery, and distributed to pediatric neurosurgeons via the AANS/CNS Joint Section email contact list. Participants were surveyed on involvement in global neurosurgical outreach, geographic location, nature of participation, and barriers to further involvement. Results A 35.3% response rate was obtained, with 116 respondents completed the survey. 61% performed or taught neurosurgery in a developing country, 49% traveling at least annually. Africa was the most common region (54%), followed by South America (30%), through 29 separate organizing entities. Hydrocephalus was the most commonly treated condition (88%), followed by spinal dysraphism (74%) and tumor (68%). Most respondents obtained follow-up through communication from local surgeons (77%). 71% believed the international experience improved their practice, and 74% were very or extremely interested in working elsewhere. Interference with current practice (61%), cost (44%), and difficulty identifying international partners (43%) were the most commonly cited barriers to participation. Conclusion Any coordinated effort to expand global neurosurgical capacity begins with appreciation for the current state of outreach efforts. Increasing participation in global outreach will require addressing both real and perceived barriers to involvement. Creation and curation of a centralized online database of ongoing projects to facilitate

  11. The Practice of Cranial Neurosurgery and the Malpractice Liability Environment in the United States

    Science.gov (United States)

    Wong, Kendrew; MacKenzie, Todd A.

    2015-01-01

    Object The potential imbalance between malpractice liability cost and quality of care has been an issue of debate. We investigated the association of malpractice liability with unfavorable outcomes and increased hospitalization charges in cranial neurosurgery. Methods We performed a retrospective cohort study involving patients who underwent cranial neurosurgical procedures from 2005-2010, and were registered in the National Inpatient Sample (NIS) database. We used data from the National Practitioner Data Bank (NPDB) from 2005 to 2010 to create measures of volume and size of malpractice claim payments. The association of the latter with the state-level mortality, length of stay (LOS), unfavorable discharge, and hospitalization charges for cranial neurosurgery was investigated. Results During the study period, there were 189,103 patients (mean age 46.4 years, with 48.3% females) who underwent cranial neurosurgical procedures, and were registered in NIS. In a multivariable regression, higher number of claims per physician in a state was associated with increased ln-transformed hospitalization charges (beta 0.18; 95% CI, 0.17 to 0.19). On the contrary, there was no association with mortality (OR 1.00; 95% CI, 0.94 to 1.06). We observed a small association with unfavorable discharge (OR 1.09; 95% CI, 1.06 to 1.13), and LOS (beta 0.01; 95% CI, 0.002 to 0.03). The size of the awarded claims demonstrated similar relationships. The average claims payment size (ln-transformed) (Pearson’s rho=0.435, P=0.01) demonstrated a positive correlation with the risk-adjusted hospitalization charges but did not demonstrate a correlation with mortality, unfavorable discharge, or LOS. Conclusions In the present national study, aggressive malpractice environment was not correlated with mortality but was associated with higher hospitalization charges after cranial neurosurgery. In view of the association of malpractice with the economics of healthcare, further research on its impact is

  12. Big Data Research in Neurosurgery: A Critical Look at this Popular New Study Design.

    Science.gov (United States)

    Oravec, Chesney S; Motiwala, Mustafa; Reed, Kevin; Kondziolka, Douglas; Barker, Fred G; Michael, L Madison; Klimo, Paul

    2018-05-01

    The use of "big data" in neurosurgical research has become increasingly popular. However, using this type of data comes with limitations. This study aimed to shed light on this new approach to clinical research. We compiled a list of commonly used databases that were not specifically created to study neurosurgical procedures, conditions, or diseases. Three North American journals were manually searched for articles published since 2000 utilizing these and other non-neurosurgery-specific databases. A number of data points per article were collected, tallied, and analyzed.A total of 324 articles were identified since 2000 with an exponential increase since 2011 (257/324, 79%). The Journal of Neurosurgery Publishing Group published the greatest total number (n = 200). The National Inpatient Sample was the most commonly used database (n = 136). The average study size was 114 841 subjects (range, 30-4 146 777). The most prevalent topics were vascular (n = 77) and neuro-oncology (n = 66). When categorizing study objective (recognizing that many papers reported more than 1 type of study objective), "Outcomes" was the most common (n = 154). The top 10 institutions by primary or senior author accounted for 45%-50% of all publications. Harvard Medical School was the top institution, using this research technique with 59 representations (31 by primary author and 28 by senior).The increasing use of data from non-neurosurgery-specific databases presents a unique challenge to the interpretation and application of the study conclusions. The limitations of these studies must be more strongly considered in designing and interpreting these studies.

  13. 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.

  14. 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. PMID:27445707

  15. IncobotulinumtoxinA treatment of facial nerve palsy after neurosurgery.

    Science.gov (United States)

    Akulov, Mihail A; Orlova, Ol'ga R; Orlova, Aleksandra S; Usachev, Dmitrij J; Shimansky, Vadim N; Tanjashin, Sergey V; Khatkova, Svetlana E; Yunosha-Shanyavskaya, Anna V

    2017-10-15

    This study evaluates the effect of incobotulinumtoxinA in the acute and chronic phases of facial nerve palsy after neurosurgical interventions. Patients received incobotulinumtoxinA injections (active treatment group) or standard rehabilitation treatment (control group). Functional efficacy was assessed using House-Brackmann, Yanagihara System and Sunnybrook Facial Grading scales, and Facial Disability Index self-assessment. Significant improvements on all scales were seen after 1month of incobotulinumtoxinA treatment (active treatment group, р<0.05), but only after 3months of rehabilitation treatment (control group, р<0.05). At 1 and 2years post-surgery, the prevalence of synkinesis was significantly higher in patients in the control group compared with those receiving incobotulinumtoxinA treatment (р<0.05 and р<0.001, respectively). IncobotulinumtoxinA treatment resulted in significant improvements in facial symmetry in patients with facial nerve injury following neurosurgical interventions. Treatment was effective for the correction of the compensatory hyperactivity of mimic muscles on the unaffected side that develops in the acute period of facial nerve palsy, and for the correction of synkinesis in the affected side that develops in the long-term period. Appropriate dosing and patient education to perform exercises to restore mimic muscle function should be considered in multimodal treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Does peroperative external pneumatic leg muscle compression prevent post-operative venous thrombosis in neurosurgery?

    Science.gov (United States)

    Bynke, O; Hillman, J; Lassvik, C

    1987-01-01

    Post-operative deep venous thrombosis (DVT) is a frequent and potentially life-threatening complication in neurosurgery. In this field of surgery, with its special demands for exact haemostasis, prophylaxis against deep venous thrombosis with anticoagulant drugs has been utilized only reluctantly. Postoperative pneumatic muscle compression (EPC) has been shown to be effective, although there are several practical considerations involved with this method which limit its clinical applicability. In the present study per-operative EPC was evaluated and was found to provide good protection against DVT in patients with increased risk from this complication. This method has the advantage of being effective, safe, inexpensive and readily practicable.

  17. 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.

  18. Sir Charles Bell (1774-1842) and his contributions to early neurosurgery.

    Science.gov (United States)

    Tubbs, R Shane; Riech, Sheryl; Verma, Ketan; Mortazavi, Martin M; Loukas, Marios; Benninger, Brion; Cohen-Gadol, Aaron A

    2012-03-01

    The renowned surgeon, neuroanatomist, and artist Sir Charles Bell not only impacted the lives of his peers through his creative endeavors and passion for art, but also sparked noteworthy breakthroughs in the field of neuroscience. His empathetic nature and zest for life enabled him to develop an early proclivity for patient care. As a result of his innovative findings regarding sensory and motor nerves and the anatomical makeup of the brain, he accepted some of the most prestigious awards and received an honorable reputation in society. Bell is recognized for his diligence, perseverance, and his remarkable contributions to surgery. The present review will explore his contributions to the discipline now known as neurosurgery.

  19. Health-related quality of life outcomes and level of evidence in pediatric neurosurgery.

    Science.gov (United States)

    Hansen, Daniel; Vedantam, Aditya; Briceño, Valentina; Lam, Sandi K; Luerssen, Thomas G; Jea, Andrew

    2016-10-01

    OBJECTIVE The emphasis on health-related quality of life (HRQOL) outcomes is increasing, along with an emphasis on evidence-based medicine. However, there is a notable paucity of validated HRQOL instruments for the pediatric population. Furthermore, no standardization or consensus currently exists concerning which HRQOL outcome measures ought to be used in pediatric neurosurgery. The authors wished to identify HRQOL outcomes used in pediatric neurosurgery research over the past 10 years, their frequency, and usage trends. METHODS Three top pediatric neurosurgical journals were reviewed for the decade from 2005 to 2014 for clinical studies of pediatric neurosurgical procedures that report HRQOL outcomes. Similar studies in the peer-reviewed journal Pediatrics were also used as a benchmark. Publication year, level of evidence, and HRQOL outcomes were collected for each article. RESULTS A total of 31 HRQOL studies were published in the pediatric neurosurgical literature over the study period. By comparison, there were 55 such articles in Pediatrics. The number of publications using HRQOL instruments showed a significant positive trend over time for Pediatrics (B = 0.62, p = 0.02) but did not increase significantly over time for the 3 neurosurgical journals (B = 0.12, p = 0.5). The authors identified a total of 46 different HRQOL instruments used across all journals. Within the neurosurgical journals, the Hydrocephalus Outcome Questionnaire (HOQ) (24%) was the most frequently used, followed by the Health Utilities Index (HUI) (16%), the Pediatric Quality of Life Inventory (PedsQL) (12%), and the 36-Item Short Form Health Survey (SF-36) (12%). Of the 55 articles identified in Pediatrics, 22 (40%) used a version of the PedsQL. No neurosurgical study reached above Level 4 on the Oxford Centre for Evidence-Based Medicine (OCEBM) system. However, multiple studies from Pediatrics achieved OCEBM Level 3, several were categorized as Level 2, and one reached Level 1

  20. Automated location detection of injection site for preclinical stereotactic neurosurgery procedure

    Science.gov (United States)

    Abbaszadeh, Shiva; Wu, Hemmings C. H.

    2017-03-01

    Currently, during stereotactic neurosurgery procedures, the manual task of locating the proper area for needle insertion or implantation of electrode/cannula/optic fiber can be time consuming. The requirement of the task is to quickly and accurately find the location for insertion. In this study we investigate an automated method to locate the entry point of region of interest. This method leverages a digital image capture system, pattern recognition, and motorized stages. Template matching of known anatomical identifiable regions is used to find regions of interest (e.g. Bregma) in rodents. For our initial study, we tackle the problem of automatically detecting the entry point.

  1. Computational Modeling for Enhancing Soft Tissue Image Guided Surgery: An Application in Neurosurgery.

    Science.gov (United States)

    Miga, Michael I

    2016-01-01

    With the recent advances in computing, the opportunities to translate computational models to more integrated roles in patient treatment are expanding at an exciting rate. One area of considerable development has been directed towards correcting soft tissue deformation within image guided neurosurgery applications. This review captures the efforts that have been undertaken towards enhancing neuronavigation by the integration of soft tissue biomechanical models, imaging and sensing technologies, and algorithmic developments. In addition, the review speaks to the evolving role of modeling frameworks within surgery and concludes with some future directions beyond neurosurgical applications.

  2. Additive manufacturing of a functionally graded material from Ti-6Al-4V to Invar: Experimental characterization and thermodynamic calculations

    International Nuclear Information System (INIS)

    Bobbio, Lourdes D.; Otis, Richard A.; Borgonia, John Paul; Dillon, R. Peter; Shapiro, Andrew A.; Liu, Zi-Kui; Beese, Allison M.

    2017-01-01

    In functionally graded materials (FGMs), the elemental composition, or structure, within a component varies gradually as a function of position, allowing for the gradual transition from one alloy to another, and the local tailoring of properties. One method for fabricating FGMs with varying elemental composition is through layer-by-layer directed energy deposition additive manufacturing. This work combines experimental characterization and computational analysis to investigate a material graded from Ti-6Al-4V to Invar 36 (64 wt% Fe, 36 wt% Ni). The microstructure, composition, phases, and microhardness were determined as a function of position within the FGM. During the fabrication process, detrimental phases associated with the compositional blending of the Ti-6Al-4V and Invar formed, leading to cracking in the final deposited part. Intermetallic phases (FeTi, Fe_2Ti, Ni_3Ti, and NiTi_2) were experimentally identified to occur throughout the gradient region, and were considered as the reason that the FGM cracked during fabrication. CALPHAD (CALculation of PHase Diagrams) thermodynamic calculations were used concurrently to predict phases that would form during the manufacturing process and were compared to the experimental results. The experimental-computational approach described herein for characterizing FGMs can be used to improve the understanding and design of other FGMs.

  3. The effects of acute inflammation on cognitive functioning and emotional processing in humans: A systematic review of experimental studies.

    Science.gov (United States)

    Bollen, Jessica; Trick, Leanne; Llewellyn, David; Dickens, Chris

    2017-03-01

    The cognitive neuropsychological model of depression proposes that negative biases in the processing of emotionally salient information have a central role in the development and maintenance of depression. We have conducted a systematic review to determine whether acute experimental inflammation is associated with changes to cognitive and emotional processing that are thought to cause and maintain depression. We identified experimental studies in which healthy individuals were administered an acute inflammatory challenge (bacterial endotoxin/vaccination) and standardised tests of cognitive function were performed. Fourteen references were identified, reporting findings from 12 independent studies on 345 participants. Methodological quality was rated strong or moderate for 11 studies. Acute experimental inflammation was triggered using a variety of agents (including endotoxin from E. coli, S. typhi, S. abortus Equi and Hepatitis B vaccine) and cognition was assessed over hours to months, using cognitive tests of i) attention/executive functioning, ii) memory and iii) social/emotional processing. Studies found mixed evidence that acute experimental inflammation caused changes to attention/executive functioning (2 of 6 studies showed improvements in attention executive function compared to control), changes in memory (3 of 5 studies; improved reaction time: reduced memory for object proximity: poorer immediate and delayed memory) and changes to social/emotional processing (4 of 5 studies; reduced perception of emotions, increased avoidance of punishment/loss experiences, and increased social disconnectedness). Acute experimental inflammation causes negative biases in social and emotional processing that could explain observed associations between inflammation and depression. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Density functional theory calculations establish the experimental evidence of the DX center atomic structure in CdTe.

    Science.gov (United States)

    Lany, Stephan; Wolf, Herbert; Wichert, Thomas

    2004-06-04

    The In DX center and the DX-like configuration of the Cd host atom in CdTe are investigated using density functional theory. The simultaneous calculation of the atomic structure and the electric field gradient (EFG) allows one to correlate the theoretically predicted structure of the DX center with an experimental observable, namely, the EFG obtained from radioactive 111In/111Cd probe atoms in In doped CdTe. In this way, the experimental identification of the DX center structure is established.

  5. Experimental investigation of alternative transmission functions: Quantitative evidence for the importance of nonlinear transmission dynamics in host-parasite systems.

    Science.gov (United States)

    Orlofske, Sarah A; Flaxman, Samuel M; Joseph, Maxwell B; Fenton, Andy; Melbourne, Brett A; Johnson, Pieter T J

    2018-05-01

    Understanding pathogen transmission is crucial for predicting and managing disease. Nonetheless, experimental comparisons of alternative functional forms of transmission remain rare, and those experiments that are conducted are often not designed to test the full range of possible forms. To differentiate among 10 candidate transmission functions, we used a novel experimental design in which we independently varied four factors-duration of exposure, numbers of parasites, numbers of hosts and parasite density-in laboratory infection experiments. We used interactions between amphibian hosts and trematode parasites as a model system and all candidate models incorporated parasite depletion. An additional manipulation involving anaesthesia addressed the effects of host behaviour on transmission form. Across all experiments, nonlinear transmission forms involving either a power law or a negative binomial function were the best-fitting models and consistently outperformed the linear density-dependent and density-independent functions. By testing previously published data for two other host-macroparasite systems, we also found support for the same nonlinear transmission forms. Although manipulations of parasite density are common in transmission studies, the comprehensive set of variables tested in our experiments revealed that variation in density alone was least likely to differentiate among competing transmission functions. Across host-pathogen systems, nonlinear functions may often more accurately represent transmission dynamics and thus provide more realistic predictions for infection. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  6. Slow angled-descent forepaw grasping (SLAG): an innate behavioral task for identification of individual experimental mice possessing functional vision.

    Science.gov (United States)

    Gil-Pagés, Macarena; Stiles, Robert J; Parks, Christopher A; Neier, Steven C; Radulovic, Maja; Oliveros, Alfredo; Ferrer, Alejandro; Reed, Brendan K; Wilton, Katelynn M; Schrum, Adam G

    2013-08-23

    There is significant interest in the generation of improved assays to clearly identify experimental mice possessing functional vision, a property that could qualify mice for inclusion in behavioral and neuroscience studies. Widely employed current methods rely on mouse responses to visual cues in assays of reflexes, depth perception, or cognitive memory. However, commonly assessed mouse reflexes can sometimes be ambiguous in their expression, while depth perception assays are sometimes confounded by variation in anxiety responses and exploratory conduct. Furthermore, in situations where experimental groups vary in their cognitive memory capacity, memory assays may not be ideal for assessing differences in vision. We have optimized a non-invasive behavioral assay that relies on an untrained, innate response to identify individual experimental mice possessing functional vision: slow angled-descent forepaw grasping (SLAG). First, we verified that SLAG performance depends on vision and not olfaction. Next, all members of an age-ranged cohort of 158 C57BL/6 mice (57 wild-type, 101 knockout, age range 44-241 days) were assessed for functional vision using the SLAG test without training or conditioning. Subjecting the population to a second innate behavioral test, Dark Chamber preference, corroborated that the functional vision assessment of SLAG was valid. We propose that the SLAG assay is immediately useful to quickly and clearly identify experimental mice possessing functional vision. SLAG is based on a behavioral readout with a significant innate component with no requirement for training. This will facilitate the selection of mice of known sighted status in vision-dependent experiments that focus on other types of behavior, neuroscience, and/or cognitive memory.

  7. Density functional theoretical analysis with experimental, invitro bioactivity and molecular docking investigations on the pesticide Albendazole

    Science.gov (United States)

    Divya, P.; Bena Jothy, V.

    2018-03-01

    Optimized structural parameters of Albendazole and corresponding vibrational assignments have been studied using infrared and Raman spectroscopy combined with quantum-chemical calculations. Results of these spectroscopic studies have been successfully compared against obtained experimental data. Difference between experimental and calculated CH3 group wavenumbers was blue-shifted by 58 cm-1 and 43 cm-1, respectively due to electronic effects. In NBO analysis the increase in energies and the shortening of Csbnd N and Cdbnd O bonds gives clear evidence that the resonance of the benzimidazole ring is increased by the groups. Best binding score of Albendazole was obtained with protein 4NQ6 (-5.58 kcal/mol).

  8. Jazz, guitar, and neurosurgery: the Pat Martino case report.

    Science.gov (United States)

    Galarza, Marcelo; Isaac, Claire; Pellicer, Olga; Mayes, Andrew; Broks, Paul; Montaldi, Daniela; Denby, Christine; Simeone, Frederick

    2014-01-01

    We present the case of a professional jazz guitarist with temporal lobe epilepsy secondary to an arteriovenous cerebral malformation. The patient underwent a left temporal lobectomy in 1980. After surgery, he presented with severe retrograde amnesia and complete loss of musical interest and capabilities. The patient's musical abilities recovered over time, and he regained his previous virtuoso status. In 2007, his medical history, neuropsychologic functions, and structural magnetic resonance imaging study were examined and revealed a remarkable degree of recovery of memory and musical abilities in the context of extensive temporal lobe resection. The neuropsychologic findings and neuroanatomic features of the magnetic resonance imaging study were analyzed to try to understand the high degree of recovery of both long-term memory and musical processing abilities in this musician. This case reveals the possibility of an unusual degree of cerebral plasticity and reorganization. Additionally, it emphasizes the question of musical virtuosity. This report shows that the musical capabilities of professional musicians, in specific cases, can completely recover even when much of the left temporal lobe has been removed. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. 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

  10. 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...

  11. Altered contralateral sensorimotor system organization after experimental hemispherectomy : A structural and functional connectivity study

    NARCIS (Netherlands)

    Otte, Wim; 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

  12. 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

    2015-08-01

    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.

  13. MR-guided stereotactic neurosurgery-comparison of fiducial-based and anatomical landmark transformation approaches

    International Nuclear Information System (INIS)

    Hunsche, S; Sauner, D; Maarouf, M; Hoevels, M; Luyken, K; Schulte, O; Lackner, K; Sturm, V; Treuer, H

    2004-01-01

    For application in magnetic resonance (MR) guided stereotactic neurosurgery, two methods for transformation of MR-image coordinates in stereotactic, frame-based coordinates exist: the direct stereotactic fiducial-based transformation method and the indirect anatomical landmark method. In contrast to direct stereotactic MR transformation, indirect transformation is based on anatomical landmark coregistration of stereotactic computerized tomography and non-stereotactic MR images. In a patient study, both transformation methods have been investigated with visual inspection and mutual information analysis. Comparison was done for our standard imaging protocol, including t2-weighted spin-echo as well as contrast enhanced t1-weighted gradient-echo imaging. For t2-weighted spin-echo imaging, both methods showed almost similar and satisfying performance with a small, but significant advantage for fiducial-based transformation. In contrast, for t1-weighted gradient-echo imaging with more geometric distortions due to field inhomogenities and gradient nonlinearity than t2-weighted spin-echo imaging, mainly caused by a reduced bandwidth per pixel, anatomical landmark transformation delivered markedly better results. Here, fiducial-based transformation yielded results which are intolerable for stereotactic neurosurgery. Mean Euclidian distances between both transformation methods were 0.96 mm for t2-weighted spin-echo and 1.67 mm for t1-weighted gradient-echo imaging. Maximum deviations were 1.72 mm and 3.06 mm, respectively

  14. [New approaches in neurosurgery and hyperbaric medicine--the importance of preventive and industrial medicine].

    Science.gov (United States)

    Kohshi, K; Munaka, M; Abe, H; Tosaki, T

    1999-12-01

    Neurosurgical patients have been mainly treated by surgical procedures over the past decades. In addition, hyperbaric oxygen (HBO) therapy in neurosurgery has been used in patients with ischemic cerebrovascular diseases, head trauma, spinal damage, postoperative brain edema and others. However, the main therapeutic methods for neurosurgical diseases have changed dramatically due to developments in radiological techniques, such as radiosurgery and intravascular surgery. With changes in therapeutic methods, HBO therapy may become a very important treatment option for neurosurgical patients. For example, HBO therapy combined with radiotherapy (UOEH regimen) and anticoagulant therapy appear to be very effective in the treatments of malignant brain tumors and ischemic cerebrovascular diseases, respectively. On the other hand, medical examinations under hyper- and hypobaric environments have not yet been fully studied in the central nervous system compared to those in the cardiopulmonary systems. Moreover, the mechanisms of cerebral lesions in decompression sickness and acute mountain sickness remain unclear. Clinical neurologic approaches are very important in these fields. Hence, clinicians and researchers skilled in both neurosurgery and hyperbaric medicine will be required for advanced treatment and preventive and industrial medicine.

  15. 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.

  16. Tissue Factor and Tissue Factor Pathway Inhibitor in the Wound-Healing Process After Neurosurgery.

    Science.gov (United States)

    Ślusarz, Robert; Głowacka, Mariola; Biercewicz, Monika; Barczykowska, Ewa; Haor, Beata; Rość, Danuta; Gadomska, Grażyna

    2016-03-01

    The aim of the study was to assess the concentrations of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in the blood of patients with a postoperative wound after neurosurgery. Participants included 20 adult patients who underwent neurosurgery because of degenerative spine changes. The concentration of TF and TFPI in the patients' blood serum was measured 3 times: before surgery, during the first 24 hr after surgery, and between the 5th and 7th days after surgery. The control group comprised 20 healthy volunteers similar to the patient group with respect to gender and age. A statistically significant difference was observed between TF concentration at all three measurement time points in the research group and TF concentration in the control group (p = .018, p = .010, p = .001). A statistically significant difference was found between TFPI concentration at the second time point in the research group and TFPI concentration in the control group (p = .041). No statistically significant within-subject difference was found between TF concentrations before and after surgery. A statistically significant within-subject difference was found between TFPI concentrations within 24 hr after surgery and 5-7 days after surgery (p = .004). High perioperative concentrations of TF indicate not only the presence of thrombophilia but also the importance of TF in the wound-healing process. Perioperative changes in TFPI concentrations are related to its compensatory influence on hemostasis in thrombophilic conditions. © The Author(s) 2015.

  17. Quantifying cortical surface harmonic deformation with stereovision during open cranial neurosurgery

    Science.gov (United States)

    Ji, Songbai; Fan, Xiaoyao; Roberts, David W.; Paulsen, Keith D.

    2012-02-01

    Cortical surface harmonic motion during open cranial neurosurgery is well observed in image-guided neurosurgery. Recently, we quantified cortical surface deformation noninvasively with synchronized blood pressure pulsation (BPP) from a sequence of stereo image pairs using optical flow motion tracking. With three subjects, we found the average cortical surface displacement can reach more than 1 mm and in-plane principal strains of up to 7% relative to the first image pair. In addition, the temporal changes in deformation and strain were in concert with BPP and patient respiration [1]. However, because deformation was essentially computed relative to an arbitrary reference, comparing cortical surface deformation at different times was not possible. In this study, we extend the technique developed earlier by establishing a more reliable reference profile of the cortical surface for each sequence of stereo image acquisitions. Specifically, fast Fourier transform (FFT) was applied to the dynamic cortical surface deformation, and the fundamental frequencies corresponding to patient respiration and BPP were identified, which were used to determine the number of image acquisitions for use in averaging cortical surface images. This technique is important because it potentially allows in vivo characterization of soft tissue biomechanical properties using intraoperative stereovision and motion tracking.

  18. MR-guided stereotactic neurosurgery-comparison of fiducial-based and anatomical landmark transformation approaches

    Energy Technology Data Exchange (ETDEWEB)

    Hunsche, S [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Sauner, D [Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller-University of Jena, Jena (Germany); Maarouf, M [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Hoevels, M [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Luyken, K [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Schulte, O [Department of Radiology, University of Cologne, Cologne (Germany); Lackner, K [Department of Radiology, University of Cologne, Cologne (Germany); Sturm, V [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany); Treuer, H [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne (Germany)

    2004-06-21

    For application in magnetic resonance (MR) guided stereotactic neurosurgery, two methods for transformation of MR-image coordinates in stereotactic, frame-based coordinates exist: the direct stereotactic fiducial-based transformation method and the indirect anatomical landmark method. In contrast to direct stereotactic MR transformation, indirect transformation is based on anatomical landmark coregistration of stereotactic computerized tomography and non-stereotactic MR images. In a patient study, both transformation methods have been investigated with visual inspection and mutual information analysis. Comparison was done for our standard imaging protocol, including t2-weighted spin-echo as well as contrast enhanced t1-weighted gradient-echo imaging. For t2-weighted spin-echo imaging, both methods showed almost similar and satisfying performance with a small, but significant advantage for fiducial-based transformation. In contrast, for t1-weighted gradient-echo imaging with more geometric distortions due to field inhomogenities and gradient nonlinearity than t2-weighted spin-echo imaging, mainly caused by a reduced bandwidth per pixel, anatomical landmark transformation delivered markedly better results. Here, fiducial-based transformation yielded results which are intolerable for stereotactic neurosurgery. Mean Euclidian distances between both transformation methods were 0.96 mm for t2-weighted spin-echo and 1.67 mm for t1-weighted gradient-echo imaging. Maximum deviations were 1.72 mm and 3.06 mm, respectively.

  19. Development of automatic navigation measuring system using template-matching software in image guided neurosurgery

    International Nuclear Information System (INIS)

    Watanabe, Yohei; Hayashi, Yuichiro; Fujii, Masazumi; Wakabayashi, Toshihiko; Kimura, Miyuki; Tsuzaka, Masatoshi; Sugiura, Akihiro

    2010-01-01

    An image-guided neurosurgery and neuronavigation system based on magnetic resonance imaging has been used as an indispensable tool for resection of brain tumors. Therefore, accuracy of the neuronavigation system, provided by periodic quality assurance (QA), is essential for image-guided neurosurgery. Two types of accuracy index, fiducial registration error (FRE) and target registration error (TRE), have been used to evaluate navigation accuracy. FRE shows navigation accuracy on points that have been registered. On the other hand, TRE shows navigation accuracy on points such as tumor, skin, and fiducial markers. This study shows that TRE is more reliable than FRE. However, calculation of TRE is a time-consuming, subjective task. Software for QA was developed to compute TRE. This software calculates TRE automatically by an image processing technique, such as automatic template matching. TRE was calculated by the software and compared with the results obtained by manual calculation. Using the software made it possible to achieve a reliable QA system. (author)

  20. Image-guided neurosurgery. Global concept of a surgical tele-assistance using obstacle detection robotics

    International Nuclear Information System (INIS)

    Desgeorges, M.; Bellegou, N.; Faillot, Th.; Cordoliani, Y.S.; Dutertre, G.; Blondet, E.; Soultrait, F. de; Boissy, J.M.

    2000-01-01

    Surgical tele-assistance significantly increases accuracy of surgical gestures, especially in the case of brain tumor neurosurgery. The robotic device is tele-operated through a microscope and the surgeon's gestures are guided by real-time overlaying of the X-ray imagery in the microscope. During the device's progression inside the brain, the focus is ensured by the microscope auto-focus feature. The surgeon can thus constantly check his position on the field workstation. Obstacles to avoid or dangerous areas can be previewed in the operation field. This system is routinely used for 5 years in the neurosurgery division of the Val de Grace hospital. More than 400 brain surgery operations have been done using it. An adaptation is used for rachis surgery. Other military hospitals begin to be equipped with similar systems. It will be possible to link them for data transfer. When it will be operational, such a network it will show what could be, in the future, a medical/surgical remote-assistance system designed to take care of wounded/critical conditions people, including assistance to surgical gestures. (authors)

  1. Functional resonance magnetic imaging (fMRI) in adolescents with idiopathic musculoskeletal pain: a paradigm of experimental pain

    OpenAIRE

    Molina, Juliana; Amaro, Edson; da Rocha, Liana Guerra Sanches; Jorge, Liliana; Santos, Flavia Heloisa; Len, Claudio A.

    2017-01-01

    Background Studies on functional magnetic resonance imaging (fMRI) have shown that adults with musculoskeletal pain syndromes tolerate smaller amount of pressure (pain) as well as differences in brain activation patterns in areas related to pain.The objective of this study was to evaluate, through fMRI, the brain activation in adolescents with idiopathic musculoskeletal pain (IMP) while performing an experimental paradigm of pain. Methods The study included 10 consecutive adolescents with idi...

  2. 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

  3. Development of neurosurgery in Germany: comparison of data collected by polls for 1997, 2003, and 2008 among providers of neurosurgical care.

    Science.gov (United States)

    Steiger, Hans J; Krämer, Michael; Reulen, Hans J

    2012-01-01

    To deduce structural trends in neurosurgery in Germany by comparison of data derived from polls conducted by the Deutsche Gesellschaft für Neurochirurgie (DGNC) in 1997, 2003 and 2008. The questionnaires of the different polls probed a comparable set of issues. The data from the responding sample were extrapolated to the nationwide average or sum and compared between the different time periods. The number of identified neurosurgical departments increased from 146 to 201 during the years 1997-2008 largely as a result of the new foundation of numerous private groups. Nationwide total neurosurgical bed capacity and intensive care unit bed capacity increased modestly over the time period. The extrapolated total number of neurosurgical operations increased from 196,341 to 319,295. Although cranial and spinal neurosurgery remain the dominant subspecialties, the number of functional neurosurgical procedures and operations for pain increased more than proportionally. Outpatient procedures were established during the time period and corresponded in 2008 to a substantial proportion of the surgical volume. The total number of residents and board-certified neurosurgeons increased during the period 1997-2008 from 1513 to 1961. The proportion of residents decreased during 1997-2003 and then increased again. The number of neurosurgical operations increased in Germany proportionally to the economic growth of other service branches over the time period. Private organizations developed more than neurosurgical departments at university and other general hospitals. Work density measured as operations per physician increased during the period 1997-2008. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Nanostructured diamine-fullerene derivatives: computational density functional theory study and experimental evidence for their formation via gas-phase functionalization.

    Science.gov (United States)

    Contreras-Torres, Flavio F; Basiuk, Elena V; Basiuk, Vladimir A; Meza-Laguna, Víctor; Gromovoy, Taras Yu

    2012-02-16

    Nanostructure derivatives of fullerene C(60) are used in emerging applications of composite matrices, including protective and decorative coating, superadsorbent material, thin films, and lightweight high-strength fiber-reinforced materials, etc. In this study, quantum chemical calculations and experimental studies were performed to analyze the derivatives of diamine-fullerene prepared by the gas-phase solvent-free functionalization technique. In particular, the aliphatic 1,8-diamino-octane and the aromatic 1,5-diaminonaphthalene, which are diamines volatile in vacuum, were studied. We addressed two alternative mechanisms of the amination reaction via polyaddition and cross-linking of C(60) with diamines, using the pure GGA BLYP, PW91, and PBE functionals; further validation calculations were performed using the semiempirical dispersion GGA B97-D functional which contains parameters that have been specially adjusted by a more realistic view on dispersion contributions. In addition, we looked for experimental evidence for the covalent functionalization by using laser desorption/ionization time-of-flight mass spectrometry, thermogravimetric analysis, and atomic force microscopy.

  5. 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.

  6. Colchicine Depolymerizes Microtubules, Increases Junctophilin-2, and Improves Right Ventricular Function in Experimental Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Prins, Kurt W; Tian, Lian; Wu, Danchen; Thenappan, Thenappan; Metzger, Joseph M; Archer, Stephen L

    2017-05-31

    Pulmonary arterial hypertension (PAH) is a lethal disease characterized by obstructive pulmonary vascular remodeling and right ventricular (RV) dysfunction. Although RV function predicts outcomes in PAH, mechanisms of RV dysfunction are poorly understood, and RV-targeted therapies are lacking. We hypothesized that in PAH, abnormal microtubular structure in RV cardiomyocytes impairs RV function by reducing junctophilin-2 (JPH2) expression, resulting in t-tubule derangements. Conversely, we assessed whether colchicine, a microtubule-depolymerizing agent, could increase JPH2 expression and enhance RV function in monocrotaline-induced PAH. Immunoblots, confocal microscopy, echocardiography, cardiac catheterization, and treadmill testing were used to examine colchicine's (0.5 mg/kg 3 times/week) effects on pulmonary hemodynamics, RV function, and functional capacity. Rats were treated with saline (n=28) or colchicine (n=24) for 3 weeks, beginning 1 week after monocrotaline (60 mg/kg, subcutaneous). In the monocrotaline RV, but not the left ventricle, microtubule density is increased, and JPH2 expression is reduced, with loss of t-tubule localization and t-tubule disarray. Colchicine reduces microtubule density, increases JPH2 expression, and improves t-tubule morphology in RV cardiomyocytes. Colchicine therapy diminishes RV hypertrophy, improves RV function, and enhances RV-pulmonary artery coupling. Colchicine reduces small pulmonary arteriolar thickness and improves pulmonary hemodynamics. Finally, colchicine increases exercise capacity. Monocrotaline-induced PAH causes RV-specific derangement of microtubules marked by reduction in JPH2 and t-tubule disarray. Colchicine reduces microtubule density, increases JPH2 expression, and improves both t-tubule architecture and RV function. Colchicine also reduces adverse pulmonary vascular remodeling. These results provide biological plausibility for a clinical trial to repurpose colchicine as a RV-directed therapy for PAH

  7. 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.

  8. An experimental evaluation of a new designed apparatus (NDA) for the rapid measurement of impaired motor function in rats.

    Science.gov (United States)

    Jarrahi, M; Sedighi Moghadam, B; Torkmandi, H

    2015-08-15

    Assessment of the ability of rat to balance by rotarod apparatus (ROTA) is frequently used as a measure of impaired motor system function. Most of these methods have some disadvantages, such as failing to sense motor coordination rather than endurance and as the sensitivity of the method is low, more animals are needed to obtain statistically significant results. We have designed and tested a new designed apparatus (NDA) to measure motor system function in rats. Our system consists of a glass box containing 4 beams which placed with 1cm distance between them, two electrical motors for rotating the beams, and a camera to record the movements of the rats. The RPM of the beams is adjustable digitally between 0 and 50 rounds per minute. We evaluated experimentally the capability of the NDA for the rapid measurement of impaired motor function in rats. Also we demonstrated that the sensitivity of the NDA increases by faster rotation speeds and may be more sensitive than ROTA for evaluating of impaired motor system function. Compared to a previous version of this task, our NDA provides a more efficient method to test rodents for studies of motor system function after impaired motor nervous system. In summary, our NDA will allow high efficient monitoring of rat motor system function and may be more sensitive than ROTA for evaluating of impaired motor system function in rats. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Treatment of malignant brain tumor. Today and tomorrow. Image-guided neurosurgery for brain tumor. A current perspective

    International Nuclear Information System (INIS)

    Kajita, Yasukazu; Fujii, Masazumi; Yoshida, Jun; Maesawa, Satoshi

    2008-01-01

    Although usefulness of the image-guided neurosurgery is well documented, there are scarce facilities having the actually operating system in Japan. Since 2006, authors' Nagoya University Hospital has had an operating room named ''Brain THEATER'', where an open MRI system APERTO (Hitachi-Medical Co.) and a navigation system Vector Vision (BrainLAB) are connected to conduct the complete image-guided neurosurgery for brain tumor by using the intraoperative MRI for continuously updating the residual tumor tissue to be dissected out. The room is pre- and intra-operatively supported by Departments of image analysis and of radiation technology in the University, and as well, is connected by net-working with another image-guided surgical room ''Brain Suite'' (Siemens 1.5 T MRI system: BrainLAB) in the neighboring facility, Nagoya Central Hospital. This paper describes the circumstances of the introduction of these systems in the Hospital, details of the image-guided surgery in the operation rooms with illustration of actual photos of the rooms and of pre-, intra- and post-operative images, outcomes of image-guided neurosurgery for brain tumor reported hitherto, image-guided neurosurgery for brain tumor's future perspectives involving robotic surgery and operation on the virtual 3D image including the net-worked one. Efforts should be made to further spread the system for performing the more non-invasive and precise surgery, and for conducting the diagnosis united with treatment. (R.T.)

  10. A unified framework for unraveling the functional interaction structure of a biomolecular network based on stimulus-response experimental data.

    Science.gov (United States)

    Cho, Kwang-Hyun; Choo, Sang-Mok; Wellstead, Peter; Wolkenhauer, Olaf

    2005-08-15

    We propose a unified framework for the identification of functional interaction structures of biomolecular networks in a way that leads to a new experimental design procedure. In developing our approach, we have built upon previous work. Thus we begin by pointing out some of the restrictions associated with existing structure identification methods and point out how these restrictions may be eased. In particular, existing methods use specific forms of experimental algebraic equations with which to identify the functional interaction structure of a biomolecular network. In our work, we employ an extended form of these experimental algebraic equations which, while retaining their merits, also overcome some of their disadvantages. Experimental data are required in order to estimate the coefficients of the experimental algebraic equation set associated with the structure identification task. However, experimentalists are rarely provided with guidance on which parameters to perturb, and to what extent, to perturb them. When a model of network dynamics is required then there is also the vexed question of sample rate and sample time selection to be resolved. Supplying some answers to these questions is the main motivation of this paper. The approach is based on stationary and/or temporal data obtained from parameter perturbations, and unifies the previous approaches of Kholodenko et al. (PNAS 99 (2002) 12841-12846) and Sontag et al. (Bioinformatics 20 (2004) 1877-1886). By way of demonstration, we apply our unified approach to a network model which cannot be properly identified by existing methods. Finally, we propose an experiment design methodology, which is not limited by the amount of parameter perturbations, and illustrate its use with an in numero example.

  11. Calculation of the weighting function and determination of the depth of correlation in micro-PIV from experimental particle images

    International Nuclear Information System (INIS)

    Hein, M; Seemann, R; Wieneke, B

    2014-01-01

    Micro-particle image velocimetry (µPIV) uses volume-illumination and imaging of particles through a single microscope objective. Displacement fields are obtained by image correlation and depend on all imaged particles, including defocused particles. The measured in-plane displacement is a weighted spatial average of the true displacement, with a weighting function W(z) that depends on the optical system and flow-gradients. The characteristic width of the weighting function W(z) is also referred to as depth of correlation (DOC) and is a measure up to which distance from the focal plane particles influence the measurement, which is crucial for the interpretation of measured flow fields. We present procedures to determine the W(z) from which the DOC can be derived and to directly determine the DOC from PIV double images, generated from experimentally recorded particle images. Both procedures provide comparable DOC results. Our approach allows determination of the DOC and W(z)as a function of out of plane gradients, optical setup parameters and PIV-analysis parameters. Experimental results for different objectives and particle sizes are discussed, revealing substantial deviations from theoretical predictions for high NA air-objectives. Moreover, using the determined weighting function W(z), the correction of measured flow profiles for errors introduced by the spatial averaging is demonstrated. (paper)

  12. 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.

  13. 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...

  14. 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.

  15. Experimental substantiation and clinical use of functional pneumoepidurography in the diagnosis of lumbar osteochondrosis i

    Energy Technology Data Exchange (ETDEWEB)

    Sharov, B.K.; Plekhanov, L.G. (Chelyabinskij Meditsinskij Inst. (USSR))

    Anatomic and X-ray correlations in 31 postmortem unfixed specimens of the vertebral lumbar region have shown that in the diagnosis of disk prolapse and commissural processes in the anterior epidural space roentgenopositive contrast substances are not much superior to roentgenonegative ones. Functional pneumoepidurogaphy used in 102 patients with lumbar osteochondrosis helped to reveal intervertebral disk prolapse at all the stages of degenerative affection, to evaluate function of the disk-ligamentous apparatus and to specify the nature of a pathological process in the epidural space.

  16. Experimental fast reactor JOYO MK-III functional test. Primary auxiliary cooling system test

    International Nuclear Information System (INIS)

    Karube, Koji; Akagi, Shinji; Terano, Toshihiro; Onuki, Osamu; Ito, Hideaki; Aoki, Hiroshi; Odo, Toshihiro

    2004-03-01

    This paper describes the results of primary auxiliary cooling system, which were done as a part of JOYO MK-III function test. The aim of the tests was to confirm the operational performance of primary auxiliary EMP and the protection system including siphon breaker of primary auxiliary cooling system. The items of the tests were: (Test No.): (Test item). 1) SKS-117: EMP start up test. 2) SKS-118-1: EMP start up test when pony motor running. 3) SKS-121: Function test of siphon breaker. The results of the tests satisfied the required performance, and demonstrated successful operation of primary auxiliary cooling system. (author)

  17. 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

    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...... 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...

  18. Experimental determination of the π meson structure functions by the Drell-Yan mechanism

    International Nuclear Information System (INIS)

    Badier, J.; Bourotte, J.; Mine, P.; Vanderhaghen, R.; Weisz, S.; Boucrot, J.; Callot, O.; Decamp, D.; Karyotakis, Y.; Lefrancois, J.; Crozon, M.; Delpierre, P.; Leray, T.; Maillard, J.; Tilquin, A.; Valentin, J.

    1983-01-01

    We have studied high statistics samples of dimuon events (proportional35,000) produced from πsup(+-) on platinum target in the mass interval 4.2 2 sigma/dx 1 dx 2 to π + and π - data. At 200 GeV, the simultaneous use of π + and π - data allows a separate determination of the valence and sea structure functions of the π. Furthermore, the 150 and 280 GeV data allow an accurate determination of the shape of the valence structure function and give an estimate of its evolution between Q 2 =25 and 50 GeV 2 . (orig.)

  19. Morphological and functional determinants of fluoxetine (Prozac)-induced pulmonary disease in an experimental model.

    Science.gov (United States)

    Capelozzi, Marco A; Leick-Maldonado, Edna A; Parra, Edwin R; Martins, Mílton A; Tibério, Iolanda F L C; Capelozzi, Vera L

    2007-05-14

    Fluoxetine treatment effects were determined by evaluating respiratory mechanics (elastance/resistance) and exhaled nitric oxide, as well as mononuclear and polymorphonuclear cell recruitment into the lungs, in an experimental guinea pig model. Guinea pigs were divided into four groups: Fl (fluoxetine only, n=7); Fl+Sw (fluoxetine and forced swimming, n=7); Ns+Sw (normal saline and forced swimming, n=8); and Ns (normal saline only, n=8). Treated animals received oral fluoxetine (10 mg/(kg day)) for 30 consecutive days. On day 31, all animals were anesthetized and mechanically ventilated so that respiratory system elastance and resistance, as well exhaled nitric oxide, could be determined. The lungs were then excised en bloc for histological and immunohistochemical evaluation. Forced swimming induced bronchodilation in untreated animals and bronchoconstriction in fluoxetine-treated animals. Fluoxetine treatment was also associated with mononuclear infiltration (predominantly into alveolar walls) and neutrophil recruitment. In addition, levels of exhaled nitric oxide, an inflammatory marker, were higher in fluoxetine-treated animals. Swimming-induced stress also amplified mononuclear cell recruitment to the lungs. These results show that, in this experimental model, fluoxetine treatment reproduces the pathology of chronic interstitial pneumonia in humans.

  20. 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

    Modeling physiological processes using tracer kinetic methods requires knowledge of the time course of the tracer concentration in blood supplying the organ. For liver studies, however, inaccessibility of the portal vein makes direct measurement of the hepatic dual-input function impossible...

  1. The functional assembly of experimental grasslands in relation to fertility and resource heterogeneity

    Czech Academy of Sciences Publication Activity Database

    Price, J. N.; Gazol, A.; Tamme, R.; Hiiesalu, Inga; Pärtel, M.

    2014-01-01

    Roč. 28, č. 2 (2014), s. 509-519 ISSN 0269-8463 Institutional support: RVO:67985939 Keywords : functional diversity * limiting similarity * niche overlap Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.828, year: 2014

  2. 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.

  3. 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...

  4. AXIFLUX, Cosine Function Fit of Experimental Axial Flux in Cylindrical Reactor

    International Nuclear Information System (INIS)

    Holte, O.

    1980-01-01

    1 - Nature of physical problem solved: Calculates the parameters of the cosine function that will best fit data from axial flux distribution measurements in a cylindrical reactor. 2 - Method of solution: Steepest descent for the minimization. 3 - Restrictions on the complexity of the problem: Number of measured points less than 200

  5. Regioselectivity in lithiation of 1-methylpyrazole: experimental, density functional theory and multinuclear NMR study

    DEFF Research Database (Denmark)

    Balle, Thomas; Begtrup, Mikael; Jaroszewski, Jerzy W.

    2006-01-01

    -position. The observed regioselectivity can be correctly predicted, at least qualitatively, using density functional B3LYP/6-31+G(d,p) calculations only when solvation effects (IEFPCM) are taken into account. The 1H,6Li HOESY and NOESY NMR spectra of the thermodynamic product 5-lithio-1-methylpyrazole (5...

  6. Experimental study of the photon structure function F2 in the high Q2 region

    International Nuclear Information System (INIS)

    Bartel, W.; Cords, D.; Dietrich, G.; Dittmann, P.; Eichler, R.; Felst, R.; Haidt, D.; Krehbiel, H.; Meier, K.; Naroska, B.

    1982-09-01

    We report on a measurement of the process e + e - → e + e - + hadrons, where one of the scattered electron is detected at large angles, with an average Q 2 of 23 GeV 2 . The results are analysed in terms of the photon structure function F 2 and are compared with QCD predictions. (orig.)

  7. The impact of several craniotomies on transcranial motor evoked potential monitoring during neurosurgery.

    Science.gov (United States)

    Tomio, Ryosuke; Akiyama, Takenori; Toda, Masahiro; Ohira, Takayuki; Yoshida, Kazunari

    2017-09-01

    OBJECTIVE Transcranial motor evoked potential (tMEP) monitoring is popular in neurosurgery; however, the accuracy of tMEP can be impaired by craniotomy. Each craniotomy procedure and changes in the CSF levels affects the current spread. The aim of this study was to investigate the influence of several craniotomies on tMEP monitoring by using C3-4 transcranial electrical stimulation (TES). METHODS The authors used the finite element method to visualize the electric field in the brain, which was generated by TES, using realistic 3D head models developed from T1-weighted MR images. Surfaces of 5 layers of the head (brain, CSF, skull, subcutaneous fat, and skin layer) were separated as accurately as possible. The authors created 5 models of the head, as follows: normal head; frontotemporal craniotomy; parietal craniotomy; temporal craniotomy; and occipital craniotomy. The computer simulation was investigated by finite element methods, and clinical recordings of the stimulation threshold level of upper-extremity tMEP (UE-tMEP) during neurosurgery were also studied in 30 patients to validate the simulation study. RESULTS Bone removal during the craniotomy positively affected the generation of the electric field in the motor cortex if the motor cortex was just under the bone at the margin of the craniotomy window. This finding from the authors' simulation study was consistent with clinical reports of frontotemporal craniotomy cases. A major decrease in CSF levels during an operation had a significantly negative impact on the electric field when the motor cortex was exposed to air. The CSF surface level during neurosurgery depends on the body position and location of the craniotomy. The parietal craniotomy and temporal craniotomy were susceptible to the effect of the changing CSF level, based on the simulation study. A marked increase in the threshold following a decrease in CSF was actually recorded in clinical reports of the UE-tMEP threshold from a temporal craniotomy

  8. 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 assessment scores overall or in any of the 7 domains scores

  9. Risk factors for local failure requiring salvage neurosurgery after radiosurgery for brain metastases

    International Nuclear Information System (INIS)

    Weltman, Eduardo; Hanriot, Rodrigo de Morais; Prisco, Flavio Eduardo; Nadalin, Wladimir; Brandt, Reynaldo Andre; Moreira, Frederico Rafael

    2004-01-01

    Objective: the aim of this study is to select the risk factors for local failure requiring salvage neurosurgery in patients with brain metastases treated with stereotactic radiosurgery in a single institution. Methods: the follow-up of 123 patients, with 255 brain metastases treated with radiosurgery at the Radiation Oncology Department of the Hospital Israelita Albert Einstein from July 1993 to August 2001, was retrospectively analyzed. The criteria for salvage neurosurgery were tumor volume enlargement, or tumor persistence leading to severe neurological symptoms, life threatening situation or critical steroid dependence. We considered the case as local failure when the histopathologic evaluation showed morphologically preserved cancer cells (tumor recurrence, persistence or progression). We applied the Fisher's exact test to evaluate the statistical correlation between local failure and primary tumor histology, volume of the brain metastases, prescribed radiosurgery dose, and whole brain radiotherapy. Results: fourteen of 123 patients (11%) underwent salvage neurosurgery. Histology showed preserved cancer cells with necrosis and/or bleeding in 11 cases (9% of the total accrual), and only necrosis with or without bleeding (without preserved cancer cells) in three cases. The primary tumor histology among the 11 patients considered with active neoplasia was malignant melanoma in five cases (21% of the patients with melanoma), breast adenocarcinoma in three (16% of the patients with breast cancer), and other histology in the remaining three. Breast cancer diagnosis, non-elective whole brain irradiation, volume of the brain metastases, and the prescribed radiosurgery dose did not correlate with the risk of local failure. Patients treated with elective whole brain radiotherapy showed fewer local failures, when compared to all patients receiving whole brain radiotherapy, and to the patients not receiving this treatment, with incidence of failure in 4%,7% and 14

  10. Experimental testing of Mackay's model for functional antagonism in the isolated costo-uterus of the rat.

    Science.gov (United States)

    Henry, P. J.; Lulich, K. M.; Paterson, J. W.

    1985-01-01

    Several key predictions of a recently developed model for functional antagonism (Mackay, 1981) were experimentally tested using the rat isolated costo-uterine preparation. In the presence of the functional antagonist fenoterol (Fen), the functional constants (KAF) for carbachol and oxotremorine (Oxo) were respectively 9.9 and 3.4 fold greater than their corresponding affinity constants (KA). According to Mackay's model for functional antagonism, the higher KAF/KA ratio for carbachol indicates that this cholinoceptor agonist has a greater efficacy than Oxo. This was confirmed by using conventional pharmacological methods. As predicted from the model of functional antagonism, the plot of KAF/KA-1 against the fraction of cholinoceptors not irreversibly blocked by phenoxybenzamine (Pbz) was linear for both carbachol and Oxo and the lines of best fit crossed the axes at a point not significantly different from the origin. The value of 4.6 for the relative efficacy of carbachol to Oxo estimated from functional antagonism studies was comparable to the value of 5.6 calculated using the method of irreversible antagonism proposed by Furchgott (1966). PMID:3840396

  11. Experimental determination of solubility parameters of oils as a function of pressure

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Duong, Diep; Andersen, Simon Ivar

    2005-01-01

    In this work, the solubility parameter of dead and live crude oils was measured at 303.15 K and up to 300 bar, using the internal pressure approach. An indirect technique was chosen, using thermal expansivities (determined from microcalorimetric measurements) and isothermal compressibilities (cal...... are measured and given as input. Therefore, a more appropriate characterization method should give better results....... (calculated from density measurements). This method was tested on seven pure compounds, and the deviation with literature data is method based on the refractive index was used to examine the validity of the results for the oils, and a deviation of ... parameter was also calculated from two cubic equations of state and compared to experimental results. In this case, the deviations are larger (up to 6.5 MPa1/2), whereas this approach gives accurate results for pure compounds. This might be due to the characterization procedure, because the volumes...

  12. EXPERIMENTAL MEASUREMENT, ANALYSIS AND MODELLING OF DEPENDENCY EMISSIVITY IN FUNCTION OF TEMPERATURE

    Directory of Open Access Journals (Sweden)

    N. Baba Ahmed

    2015-08-01

    Full Text Available We propose a direct method of measurement of the total emissivity of opaque samples on a range of temperature around the ambient one. The method rests on the modulation of the temperature of the sample and the infra-red signal processing resulting from the surface of the sample we model the total emissivity obtained in experiments according to the temperature to establish linear correlations. This leads us to apply the method of optimal linearization associated the finite element method with the nonlinear problem of transfer of heat if thermal conductivity, the specific heat and the emissivity of studied material depend on the temperature. We obtain a good agreement between the resolution of the nonlinear equation of heat and the results obtained by the experimentation. .

  13. Treatment with Entinostat Heals Experimental Cholera by Affecting Physical and Chemical Barrier Functions of Intestinal Epithelia.

    Science.gov (United States)

    Sarker, Protim; Banik, Atanu; Stromberg, Roger; Gudmundsson, Gudmundur H; Raqib, Rubhana; Agerberth, Birgitta

    2017-07-01

    We have shown previously that oral treatment with sodium butyrate or phenylbutyrate in an experimental model of shigellosis improves clinical outcomes and induces the expression of the antimicrobial peptide CAP-18 in the large intestinal epithelia. In a subsequent study, we found that entinostat, an aroylated phenylenediamine compound, has similar therapeutic potential against shigellosis. In this study, we aimed to evaluate entinostat as a potential candidate for host-directed therapy against cholera in an experimental model. Vibrio cholerae -infected rabbits were treated with two different dose regimens of entinostat: either 0.5 mg twice daily for 2 days or 1 mg once daily for 2 days. The effects of treatment on clinical outcomes and V. cholerae shedding (CFU count in stool) were observed. Immunohistochemical analysis was carried out to assess CAP-18 expression in ileal and jejunal mucosae. The serum zonulin level was measured by an enzyme-linked immunosorbent assay (ELISA) to evaluate gut permeability. Infection of rabbits with V. cholerae downregulated CAP-18 expression in the ileal epithelium; the expression was replenished by oral treatment with entinostat at either dose regimen. The level of zonulin, a marker of gut permeability, in serum was upregulated after infection, and this upregulation was counteracted after treatment with entinostat. Entinostat treatment also led to recovery from cholera and a decline in the V. cholerae count in stool. In conclusion, the improved clinical outcome of cholera for rabbits treated with entinostat is associated with the induction of CAP-18 and the reduction of gut epithelial permeability. Copyright © 2017 American Society for Microbiology.

  14. 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......, 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....... CONCLUSION: This is the first study to show that the histological regeneration of hypopigmented RPE correlates to a return of the retinal function, measured by mfERG....

  15. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Viitanen, Matti; Sundström, Erik; Baumann, Marc; Poyhonen, Minna; Tikka, Saara; Behbahani, Homira

    2013-01-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ m ) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  16. Changes in plant species richness induce functional shifts in soil nematode communities in experimental grassland.

    Directory of Open Access Journals (Sweden)

    Nico Eisenhauer

    Full Text Available Changes in plant diversity may induce distinct changes in soil food web structure and accompanying soil feedbacks to plants. However, knowledge of the long-term consequences of plant community simplification for soil animal food webs and functioning is scarce. Nematodes, the most abundant and diverse soil Metazoa, represent the complexity of soil food webs as they comprise all major trophic groups and allow calculation of a number of functional indices.We studied the functional composition of nematode communities three and five years after establishment of a grassland plant diversity experiment (Jena Experiment. In response to plant community simplification common nematode species disappeared and pronounced functional shifts in community structure occurred. The relevance of the fungal energy channel was higher in spring 2007 than in autumn 2005, particularly in species-rich plant assemblages. This resulted in a significant positive relationship between plant species richness and the ratio of fungal-to-bacterial feeders. Moreover, the density of predators increased significantly with plant diversity after five years, pointing to increased soil food web complexity in species-rich plant assemblages. Remarkably, in complex plant communities the nematode community shifted in favour of microbivores and predators, thereby reducing the relative abundance of plant feeders after five years.The results suggest that species-poor plant assemblages may suffer from nematode communities detrimental to plants, whereas species-rich plant assemblages support a higher proportion of microbivorous nematodes stimulating nutrient cycling and hence plant performance; i.e. effects of nematodes on plants may switch from negative to positive. Overall, food web complexity is likely to decrease in response to plant community simplification and results of this study suggest that this results mainly from the loss of common species which likely alter plant-nematode interactions.

  17. Time constants and feedback transfer functions of EBR-II [Experimental Breeder Reactor] subassembly types

    International Nuclear Information System (INIS)

    Grimm, K.N.; Meneghetti, D.

    1986-09-01

    Time constants, feedback reactivity transfer functions and power coefficients are calculated for stereotypical subassemblies in the EBR-II reactor. These quantities are calculated from nodal reactivities obtained from a reactor kinetic code analysis for a step change in power. Due to the multiplicity of eigenvalues, there are several time constants for each nodal position in a subassembly. Compared with these calculated values are analytically derived values for the initial node of a given channel

  18. 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 ...... of biomolecules required for brain repair, thereby stimulating brain plasticity. Pharmacological targeting of the sigma-1 receptor provides new opportunities for stroke treatment beyond the therapeutic window of neuroprotection....

  19. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Viitanen, Matti [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Department of Geriatrics, Turku City Hospital and University of Turku, Turku (Finland); Sundström, Erik [Division of Neurodegeneration, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Baumann, Marc [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Poyhonen, Minna [Department of Clinical Genetics, Helsinki University Hospital, HUSLAB, Helsinki (Finland); Tikka, Saara [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Behbahani, Homira, E-mail: homira.behbahani@ki.se [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Karolinska Institutet Alzheimer' s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden)

    2013-02-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ{sub m}) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  20. Comparison between Fenugreek and Lovastatin in restoration of endothelial function in an experimental old rat model

    Directory of Open Access Journals (Sweden)

    "Pipelzadeh MH

    2003-06-01

    Full Text Available The aim of this study was to compare the effectiveness of Fenugreek (Trigonella foenum-graecum with that of lovastatin in restoration of endothelia function in the aorta taken form aged N-Mair rats. For this purpose, 4 groups of old N-Mari rats were used (n=6, normal saline treated control group, lovastatin (10 mg/kg, orally and fengreek seed powder in normal saline suspension (100 or 500 mg/kg were administered orally daily for 8 weeks. The rate of relaxation of ephedrine- precontracted aorta to acetycholine, the lipid profiles, and histological examinations of the aorta were compared between these two groups and with a control non-treated normal saline treated group. The results showed that treatment with lovastatin and fenugreek produced significant reduction in IDL, VLDL triglyceride and total cholesterol, while HDL was increased as compared to control non-treated group. Lovastatin induced an increase in contraction/mg tissue weight. However, improvement in endothelial function was significantly increased in all treatment groups. The histological findings showed significant reduction in thickness and lipid deposits in the aorta in all treatment groups. The improvement in the epithelial function was correlated with LDL-cholesterol lowering and partly with the reduction in the thickness of the aortic intimal layer. This study demonstrated that fenugreek is as effective as lovastatin in reducing the features associated with atherosclerosis.

  1. Experimental response function of NaI(Tl) scintillation detector for gamma photons and tomographic measurements for defect detection

    International Nuclear Information System (INIS)

    Sharma, Amandeep; Singh, Karamjit; Singh, Bhajan; Sandhu, B.S.

    2011-01-01

    The response function of gamma detector is an important factor for spectrum analysis because some photons and secondary electrons may escape the detector volume before fully depositing their energy, of course destroys the ideal delta function response. An inverse matrix approach, for unfolding of observed pulse-height distribution to a true photon spectrum, is used for construction of experimental response function by formulating a 40 x 40 matrix with bin mesh (E 1/2 ) of 0.025 (MeV) 1/2 for the present measurements. A tomographic scanner system, operating in a non-destructive and non-invasive way, is also presented for inspection of density variation in any object. The incoherent scattered intensity of 662 keV gamma photons, obtained by unfolding (deconvolution) the experimental pulse-height distribution of NaI(Tl) scintillation detector, provides the desired information. The method is quite sensitive, for showing inclusion of medium Z (atomic number) material (iron) in low Z material (aluminium) and detecting a void of ∼2 mm in size for iron block, to investigate the inhomogeneities in the object. Also, the grey scale images (using 'MATLAB') are shown to visualise the presence of defects/inclusion in metal samples.

  2. Functionalization of glassy carbon surface by means of aliphatic and aromatic amino acids. An experimental and theoretical integrated approach

    International Nuclear Information System (INIS)

    Vanossi, Davide; Benassi, Rois; Parenti, Francesca; Tassinari, Francesco; Giovanardi, Roberto; Florini, Nicola; De Renzi, Valentina; Arnaud, Gaelle; Fontanesi, Claudio

    2012-01-01

    Highlights: ► Glassy carbon is functionalized via electrochemical assisted grafting of amino acids. ► The grafting mechanism is suggested to involve the “zwitterionic” species. ► DFT calculations allowed to determine the electroactive species. ► An original grafting mechanism is proposed. - Abstract: Glassy carbon (GC) electrode surfaces are functionalized through electrochemical assisted grafting, in oxidation regime, of six amino acids (AA): β-alanine (β-Ala), L-aspartic acid (Asp), 11-aminoundecanoic acid (UA), 4-aminobenzoic acid (PABA), 4-(4-amino-phenyl)-butyric acid (PFB), 3-(4-amino-phenyl)-propionic acid (PFP). Thus, a GC/AA interface is produced featuring carboxylic groups facing the solution. Electrochemical (cyclic voltammetry and electrochemical impedance spectroscopy) and XPS techniques are used to experimentally characterize the grafting process and the surface state. The theoretical results are compared with the experimental evidence to determine, at a molecular level, the overall grafting mechanism. Ionization potentials, standard oxidation potentials, HOMO and electron spin distributions are calculated at the CCD/6-31G* level of the theory. The comparison of experimental and theoretical data suggests that the main electroactive species is the “zwitterionic” form for the three aliphatic amino acids, while the amino acids featuring the amino group bound to the phenyl aromatic moiety show a different behaviour. The comparison between experimental and theoretical results suggests that both the neutral and the zwitterionic forms are present in the acetonitrile solution in the case of 4-(4-amino-phenyl)-butyric acid (PFB) and 3-(4-amino-phenyl)-propionic acid.

  3. Recovery coefficients for the quantification of the arterial input function from dynamic pet measurements: experimental and theoretical determination

    International Nuclear Information System (INIS)

    Brix, G.; Bellemann, M.E.; Hauser, H.; Doll, J.

    2002-01-01

    Aim: For kinetic modelling of dynamic PET data, the arterial input function can be determined directly from the PET scans if a large artery is visualized on the images. It was the purpose of this study to experimentally and theoretically determine recovery coefficients for cylinders as a function of the diameter and level of background activity. Methods: The measurements were performed using a phantom with seven cylinder inserts (φ = 5-46 mm). The cylinders were filled with an aqueous 68 Ga solution while the main chamber was filled with a 18 F solution in order to obtain a varying concentration ratio between the cylinders and the background due to the different isotope half lives. After iterative image reconstruction, the activity concentrations were measured in the center of the cylinders and the recovery coefficients were calculated as a function of the diameter and the background activity. Based on the imaging properties of the PET system, we also developed a model for the quantitative assessment of recovery coefficients. Results: The functional dependence of the measured recovery data from the cylinder diameter and the concentration ratio is well described by our model. For dynamic PET measurements, the recovery correction must take into account the decreasing concentration ratio between the blood vessel and the surrounding tissue. Under the realized measurement and data analysis conditions, a recovery correction is required for vessels with a diameter of up to 25 mm. Conclusions: Based on the experimentally verified model, the activity concentration in large arteries can be calculated from the measured activity concentration in the blood vessel and the background activity. The presented approach offers the possibility to determine the arterial input function for pharmacokinetic PET studies non-invasively from large arteries (especially the aorta). (orig.) [de

  4. The Role of Neurosurgery in Countries with Limited Facilities: Facts and Challenges.

    Science.gov (United States)

    Servadei, Franco; Rossini, Zefferino; Nicolosi, Federico; Morselli, Carlotta; Park, Kee B

    2018-04-01

    The Lancet Commission on Global Surgery has recently focused its attention on the lack of surgical care worldwide. Like other surgical subspecialties, neurosurgical care needs to be better distributed around the world, with a major focus on low- to middle-income countries. Neurosurgical diseases like hydrocephalus, traumatic brain injury, and brain tumors have a high impact on families, individual quality of life, and cost for the society. Implementation of neurosurgical care in poor settings is not easy. More than other surgeries, neurosurgery requires great amounts of human resources, dedicated environments, and specialized postoperative care. It is responsibility of the neurosurgical community to identify major areas of current gaps and outline strategies for intervention. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. The Reasons Of Patients With Headache Chosing The Neurosurgery Outpatient Clinic

    Directory of Open Access Journals (Sweden)

    Halil Murat Şen

    2014-09-01

    Full Text Available OBJECTIVE: We aimed to investigate the preference causes of the patients who were admitted to the neurosurgery clinic with complaints of headache for admission in this clinic. METHODS: The study population has been selected from brain surgery department outpatient clinic. One hundred patients with complaints of headache were enrolled in this study. RESULTS: Questioned the reasons for choosing the neurosurgical and most preferred cause of including word for brain surgery of the brain named (n=54, 54%. Patients were questioned about the information of the neurology and demostrated that there was not any knowledge about neurology (n=66, 66%. CONCLUSION: Headache causes loss of the financial and workforce. Preferences in the wrong departments of the patients, as a result of misdiagnosis and inadequate treatment, increasing the number of hospital admissions. This shows that how important names and introduction of the departments

  6. Experimental determination of frequency response function estimates for flexible joint industrial manipulators with serial kinematics

    Science.gov (United States)

    Saupe, Florian; Knoblach, Andreas

    2015-02-01

    Two different approaches for the determination of frequency response functions (FRFs) are used for the non-parametric closed loop identification of a flexible joint industrial manipulator with serial kinematics. The two applied experiment designs are based on low power multisine and high power chirp excitations. The main challenge is to eliminate disturbances of the FRF estimates caused by the numerous nonlinearities of the robot. For the experiment design based on chirp excitations, a simple iterative procedure is proposed which allows exploiting the good crest factor of chirp signals in a closed loop setup. An interesting synergy of the two approaches, beyond validation purposes, is pointed out.

  7. 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.

  8. Misclassification of Case-Control Studies in Neurosurgery and Proposed Solutions.

    Science.gov (United States)

    Esene, Ignatius Ngene; Mbuagbaw, Lawrence; Dechambenoit, Gilbert; Reda, Wael; Kalangu, Kazadi K

    2018-04-01

    Case-control studies (CCS) and cohort studies (CS) are common research designs in neurosurgery. But the term case-control study is frequently misused in the neurosurgical literature, with many articles reported as CCS, even although their methodology does not respect the basic components of a CCS. We sought to estimate the extent of these discrepancies in neurosurgical literature, explore factors contributing to mislabeling, and shed some light on study design reporting. We identified 31 top-ranking pure neurosurgical journals and searched them for articles reported as CCS, either in the title or in the abstract. The articles were read to determine if they really were CCS according to STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Article assessment was conducted in duplicate (agreement [κ statistics] = 99.82%). Two hundred and twenty-four articles met our inclusion criteria, 133 of which (59.38%) correctly labeled the case-control design, whereas 91 (40.62%) misclassified this study design. Cohort studies (CS) were the most common design mislabeled as case-control studies in 76 articles (33.93%), 57 of which (25.45%) were retrospective CS. The mislabeling of CCS impairs the appropriate indexing, classification, and sorting of evidence. Mislabeling CS for CCS leads to a downgrading of evidence as CS represent the highest level of evidence for observational studies. Odds ratios instead of relative risk are reported for these studies, resulting in a distortion of the measurement of the effect size, compounded when these are summarized in systematic reviews and pooled in meta-analyses. Many studies reported as CCS are not true CCS. Reporting guidelines should include items that ensure that studies are labeled correctly. STROBE guidelines should be implemented in assessment of observational studies. Researchers in neurosurgery need better training in research methods and terminology. We also recommend accrued vigilance from

  9. Feasibility of Protective Ventilation During Elective Supratentorial Neurosurgery: A Randomized, Crossover, Clinical Trial.

    Science.gov (United States)

    Ruggieri, Francesco; Beretta, Luigi; Corno, Laura; Testa, Valentina; Martino, Enrico A; Gemma, Marco

    2017-06-30

    Traditional ventilation approaches, providing high tidal volumes (Vt), produce excessive alveolar distention and lung injury. Protective ventilation, employing lower Vt and positive end-expiratory pressure (PEEP), is an attractive alternative also for neuroanesthesia, when prolonged mechanical ventilation is needed. Nevertheless, protective ventilation during intracranial surgery may exert dangerous effects on intracranial pressure (ICP). We tested the feasibility of a protective ventilation strategy in neurosurgery. Our monocentric, double-blind, 1:1 randomized, 2×2 crossover study aimed at studying the effect size and variability of ICP in patients undergoing elective supratentorial brain tumor removal and alternatively ventilated with Vt 9 mL/kg-PEEP 0 mm Hg and Vt 7 mL/kg-PEEP 5 mm Hg. Respiratory rate was adjusted to maintain comparable end-tidal carbon dioxide between ventilation modes. ICP was measured through a subdural catheter inserted before dural opening. Forty patients were enrolled; 8 (15%) were excluded after enrollment. ICP did not differ between traditional and protective ventilation (11.28±5.37, 11 [7 to 14.5] vs. 11.90±5.86, 11 [8 to 15] mm Hg; P=0.541). End-tidal carbon dioxide (28.91±2.28, 29 [28 to 30] vs. 28.00±2.17, 28 [27 to 29] mm Hg; Pprotective ventilation. Blood pressure, heart rate, and body temperature did not differ between ventilation modes. Dural tension was "acceptable for surgery" in all cases. ICP differences between ventilation modes were not affected by ICP values under traditional ventilation (coefficient=0.067; 95% confidence interval, -0.278 to 0.144; P=0.523). Protective ventilation is a feasible alternative to traditional ventilation during elective neurosurgery.

  10. Non-rigid registration of 3D ultrasound for neurosurgery using automatic feature detection and matching.

    Science.gov (United States)

    Machado, Inês; Toews, Matthew; Luo, Jie; Unadkat, Prashin; Essayed, Walid; George, Elizabeth; Teodoro, Pedro; Carvalho, Herculano; Martins, Jorge; Golland, Polina; Pieper, Steve; Frisken, Sarah; Golby, Alexandra; Wells, William

    2018-06-04

    The brain undergoes significant structural change over the course of neurosurgery, including highly nonlinear deformation and resection. It can be informative to recover the spatial mapping between structures identified in preoperative surgical planning and the intraoperative state of the brain. We present a novel feature-based method for achieving robust, fully automatic deformable registration of intraoperative neurosurgical ultrasound images. A sparse set of local image feature correspondences is first estimated between ultrasound image pairs, after which rigid, affine and thin-plate spline models are used to estimate dense mappings throughout the image. Correspondences are derived from 3D features, distinctive generic image patterns that are automatically extracted from 3D ultrasound images and characterized in terms of their geometry (i.e., location, scale, and orientation) and a descriptor of local image appearance. Feature correspondences between ultrasound images are achieved based on a nearest-neighbor descriptor matching and probabilistic voting model similar to the Hough transform. Experiments demonstrate our method on intraoperative ultrasound images acquired before and after opening of the dura mater, during resection and after resection in nine clinical cases. A total of 1620 automatically extracted 3D feature correspondences were manually validated by eleven experts and used to guide the registration. Then, using manually labeled corresponding landmarks in the pre- and post-resection ultrasound images, we show that our feature-based registration reduces the mean target registration error from an initial value of 3.3 to 1.5 mm. This result demonstrates that the 3D features promise to offer a robust and accurate solution for 3D ultrasound registration and to correct for brain shift in image-guided neurosurgery.

  11. 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

  12. Morbidity associated with 30-day surgical site infection following nonshunt pediatric neurosurgery

    Science.gov (United States)

    Sherrod, Brandon A.; Rocque, Brandon G.

    2017-01-01

    Objective Morbidity associated with surgical site infection (SSI) following nonshunt pediatric neurosurgical procedures is poorly understood. The purpose of this study was to analyze acute morbidity and mortality associated with SSI after nonshunt pediatric neurosurgery using a nationwide cohort. Methods The authors reviewed data from the American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP-P) 2012–2014 database, including all neurosurgical procedures performed on pediatric patients. Procedures were categorized by Current Procedural Terminology (CPT) codes. CSF shunts were excluded. Deep and superficial SSIs occurring within 30 days of an index procedure were identified. Deep SSIs included deep wound infections, intracranial abscesses, meningitis, osteomyelitis, and ventriculitis. The following outcomes occurring within 30 days of an index procedure were analyzed, along with postoperative time to complication development: sepsis, wound disruption, length of postoperative stay, readmission, reoperation, and death. Results A total of 251 procedures associated with a 30-day SSI were identified (2.7% of 9296 procedures). Superficial SSIs were more common than deep SSIs (57.4% versus 42.6%). Deep SSIs occurred more frequently after epilepsy or intracranial tumor procedures. Superficial SSIs occurred more frequently after skin lesion, spine, Chiari decompression, craniofacial, and myelomeningocele closure procedures. The mean (± SD) postoperative length of stay for patients with any SSI was 9.6 ± 14.8 days (median 4 days). Post-SSI outcomes significantly associated with previous SSI included wound disruption (12.4%), sepsis (15.5%), readmission (36.7%), and reoperation (43.4%) (p neurosurgery. Rates of SSI-associated complications are significantly lower in patients with superficial infection than in those with deep infection. There were no cases of SSI-related mortality within 30 days of the index procedure. PMID:28186474

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

    Science.gov (United States)

    Owojuyigbe, Afolabi Muyiwa; Komolafe, Edward O.; Adenekan, Anthony T.; Dada, Muyiwa A.; Onyia, Chiazor U.; Ogunbameru, Ibironke O.; Owagbemi, Oluwafemi F.; Talabi, Ademola O.; Faponle, Fola A.

    2016-01-01

    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. PMID:27251657

  14. 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 < 0.003), H-index ≥ 2 during residency (OR [95% CI]: 2.32 [1.40-1.69]; P < 0.0001) and having devoted research time before residency (OR [95% CI]: 1.56 [1.10-2.22]; P < 0.012). Notably, publications before residency were not an independent indicator of 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.

  15. 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.

  16. Gold Nanoparticles on Functionalized Silicon Substrate under Coulomb Blockade Regime: An Experimental and Theoretical Investigation.

    Science.gov (United States)

    Pluchery, Olivier; Caillard, Louis; Dollfus, Philippe; Chabal, Yves J

    2018-01-18

    Single charge electronics offer a way for disruptive technology in nanoelectronics. Coulomb blockade is a realistic way for controlling the electric current through a device with the accuracy of one electron. In such devices the current exhibits a step-like increase upon bias which reflects the discrete nature of the fundamental charge. We have assembled a double tunnel junction on an oxide-free silicon substrate that exhibits Coulomb staircase characteristics using gold nanoparticles (AuNPs) as Coulomb islands. The first tunnel junction is an insulating layer made of a grafted organic monolayer (GOM) developed for this purpose. The GOM also serves for attaching AuNPs covalently. The second tunnel junction is made by the tip of an STM. We show that this device exhibits reproducible Coulomb blockade I-V curves at 40 K in vacuum. We also show that depending on the doping of the silicon substrate, the whole Coulomb staircase can be adjusted. We have developed a simulation approach based on the orthodox theory that was completed by calculating the bias dependent tunnel barriers and by including an accurate calculation of the band bending. This model accounts for the experimental data and the doping dependence of Coulomb oscillations. This study opens new perspectives toward designing new kind of single electron transistors (SET) based on this dependence of the Coulomb staircase with the charge carrier concentration.

  17. Experimental development of a liquid xenon Compton telescope for functional medical imaging

    International Nuclear Information System (INIS)

    Oger, Tugdual

    2012-01-01

    3γ imaging is a new nuclear medical imaging technique which has been suggested by Subatech laboratory. This technique involves locating three-dimensional position of the decay of an innovative radioisotope (β + ,γ) emitter, the 44 Sc. The principle consist in the detection of two photons of 511 keV gamma rays from the decay of the positron, provided by a PET ring detector, associated to the detection of the third photon by a Liquid xenon Compton telescope. The energy deposited in the interaction between the photon and xenon and its position are identified by measuring the ionization signal with a Micromegas chamber (Micro-Mesh Gaseous Structure), while the trigger and time measurement of the interaction are provided by the detection of the scintillation signal. The principle of the TPC is thus used to Compton imaging. In order to demonstrate experimentally the feasibility of imaging 3γ, a small prototype, XEMIS (Xenon Medical Imaging System) was developed. This thesis is an important step towards the proof of feasibility. In this work are exposed the characterization of the detector response for a beam of 511 keV gamma rays and the analysis of data derived from it. The measurement of energy and time resolutions will be presented, as well as the purity of the liquid xenon. (author) [fr

  18. Experimental approaches to identify cellular G-quadruplex structures and functions.

    Science.gov (United States)

    Di Antonio, Marco; Rodriguez, Raphaël; Balasubramanian, Shankar

    2012-05-01

    Guanine-rich nucleic acids can fold into non-canonical DNA secondary structures called G-quadruplexes. The formation of these structures can interfere with the biology that is crucial to sustain cellular homeostases and metabolism via mechanisms that include transcription, translation, splicing, telomere maintenance and DNA recombination. Thus, due to their implication in several biological processes and possible role promoting genomic instability, G-quadruplex forming sequences have emerged as potential therapeutic targets. There has been a growing interest in the development of synthetic molecules and biomolecules for sensing G-quadruplex structures in cellular DNA. In this review, we summarise and discuss recent methods developed for cellular imaging of G-quadruplexes, and the application of experimental genomic approaches to detect G-quadruplexes throughout genomic DNA. In particular, we will discuss the use of engineered small molecules and natural proteins to enable pull-down, ChIP-Seq, ChIP-chip and fluorescence imaging of G-quadruplex structures in cellular DNA. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. 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 OSI values (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.

  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. Experimental investigations of radiological and nuclear functional diagnosis of the ureter

    International Nuclear Information System (INIS)

    Wolf, M.

    1980-01-01

    A new nuclear method for reflux and motility investigations of the ureter is described, and its diagnostic potential is determined in model experiments. Thresholds of visualisation of a urine spindle are considered. The following results were obtained in animal experiments: 1) If investigations are repeated under identical conditions, there are considerable variations of refluxivity. 2) With IMCU (Isotope Micturition Cystoureterogram), the number of refluxes detected is about the same as with MCU (Micturition Cystoureterogram); this applies in particular to refluxes of the 3rd and 4th degree. 3) UKG is equal to AUR in judging the direction, time, velocity and frequency of discharge of a spindle while thickness and initial conus lenght of a spindle are better seen in AUR. 4) Inconstant depots of residual urine can be detected by UKG an AUR alike. The radiological observations made in the animal experiment are compared with the relevant literature, and possible error sources in the evaluation are indicated. Finally, the application of IMCU and UKG in humans is described. IMCU is recommended especially for pardiatric applications as the observation time is long and radiation exposure low. In renal function studies, the UKG supplies extensive information on functional data of the ureter which until now could be obtained only with the aid of contrast media. (orig./MG) [de

  2. The Function of Gas Vesicles in Halophilic Archaeaand Bacteria: Theories and Experimental Evidence

    Science.gov (United States)

    Oren, Aharon

    2012-01-01

    A few extremely halophilic Archaea (Halobacterium salinarum, Haloquadratum walsbyi, Haloferax mediterranei, Halorubrum vacuolatum, Halogeometricum borinquense, Haloplanus spp.) possess gas vesicles that bestow buoyancy on the cells. Gas vesicles are also produced by the anaerobic endospore-forming halophilic Bacteria Sporohalobacter lortetii and Orenia sivashensis. We have extensive information on the properties of gas vesicles in Hbt. salinarum and Hfx. mediterranei and the regulation of their formation. Different functions were suggested for gas vesicle synthesis: buoying cells towards oxygen-rich surface layers in hypersaline water bodies to prevent oxygen limitation, reaching higher light intensities for the light-driven proton pump bacteriorhodopsin, positioning the cells optimally for light absorption, light shielding, reducing the cytoplasmic volume leading to a higher surface-area-to-volume ratio (for the Archaea) and dispersal of endospores (for the anaerobic spore-forming Bacteria). Except for Hqr. walsbyi which abounds in saltern crystallizer brines, gas-vacuolate halophiles are not among the dominant life forms in hypersaline environments. There only has been little research on gas vesicles in natural communities of halophilic microorganisms, and the few existing studies failed to provide clear evidence for their possible function. This paper summarizes the current status of the different theories why gas vesicles may provide a selective advantage to some halophilic microorganisms. PMID:25371329

  3. Functional perineal colostomy with pudendal nerve anastomosis following anorectal resection: an experimental study.

    Science.gov (United States)

    Sato, T; Konishi, F

    1996-06-01

    The aim was to reconstruct the functional anus by using a transposed skeletal muscle with pudendal nerve anastomosis (PNA) after anorectal resection. Transposition of the biceps femoris muscle (BFM) with PNA around the perineal colostomy was performed in 22 dogs. In the control group (n = 11) the BFM with its own nerve was used. Evaluation was done at 3 to 5 months after the operation. A contraction with evoked potential on electrical stimulation of the pudendal nerve (22 of 22) and tonic electrical activity (10 of 10) were observed in the dogs with PNA but not in those without PNA. Increased electrical activity (6 of 6) and a reactive rise in the neoanal canal pressure (9 of 13) were seen just after the insertion of a microballoon in the dogs with PNA but not in those without PNA. The neoanal canal length was elongated, and the anorectal angle became acute on electrical stimulation in both groups. No difference was seen in the resting anal pressure between both groups. The pattern of actomyosin adenosine 5'-triphosphatase staining of the neosphincter with PNA converted from that of a BFM to that of the external anal sphincter. The defecatory status in the study group was better according to the evaluation of the feces on the cage floor. Acceptable neoanal function was achieved through the sphincter reconstruction with PNA.

  4. Microvessel organization and structure in experimental brain tumors: microvessel populations with distinctive structural and functional properties.

    Science.gov (United States)

    Schlageter, K E; Molnar, P; Lapin, G D; Groothuis, D R

    1999-11-01

    We studied microvessel organization in five brain tumor models (ENU, MSV, RG-2, S635cl15, and D-54MG) and normal brain, including microvessel diameter (LMVD), intermicrovessel distance (IMVD), microvessel density (MVD), surface area (S(v)), and orientation. LMVD and IMVD were larger and MVD was lower in tumors than normal brain. S(v) in tumors overlapped normal brain values and orientation was random in both tumors and brain. ENU and RG-2 tumors and brain were studied by electron microscopy. Tumor microvessel wall was thicker than that of brain. ENU and normal brain microvessels were continuous and nonfenestrated. RG-2 microvessels contained fenestrations and endothelial gaps; the latter had a maximum major axis of 3.0 microm. Based on anatomic measurements, the pore area of RG-2 tumors was estimated at 7.4 x 10(-6) cm(2) g(-1) from fenestrations and 3.5 x 10(-5) cm(2) g(-1) from endothelial gaps. Increased permeability of RG-2 microvessels to macromolecules is most likely attributable to endothelial gaps. Three microvessel populations may occur in brain tumors: (1) continuous nonfenestrated, (2) continuous fenestrated, and (3) discontinuous (with or without fenestrations). The first group may be unique to brain tumors; the latter two are similar to microvessels found in systemic tumors. Since structure-function properties of brain tumor microvessels will affect drug delivery, studies of microvessel function should be incorporated into clinical trials of brain tumor therapy, especially those using macromolecules. Copyright 1999 Academic Press.

  5. 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.

  6. 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.

  7. Experimental studies on excitation functions of the proton-induced activation reactions on silver

    International Nuclear Information System (INIS)

    Uddin, M.S.; Hagiwara, M.; Baba, M.; Tarkanyi, F.; Ditroi, F.

    2005-01-01

    Excitation functions were measured for the production of 106m,105 Ag, 103,101,100 Pd, 105,102,101m,100,99 Rh and 97 Ru via proton-induced activation reactions on natural silver using a stacked foil technique in the energy range 11-80 MeV. The residual activity measurements were carried out nondestructively by the high-resolution HPGe γ-ray spectroscopy. Thick target integral yields were deduced using the measured cross-sections from the respective threshold energies of the investigated reactions up to 80 MeV. The present work gives new results for the investigated radionuclides. The data in MENDL-2P deduced with the theoretical model code ALICE-IPPE are consistent in shape with the measured values, but show disagreement in magnitude

  8. Experimental analysis of bidirectional reflectance distribution function cross section conversion term in direction cosine space.

    Science.gov (United States)

    Butler, Samuel D; Nauyoks, Stephen E; Marciniak, Michael A

    2015-06-01

    Of the many classes of bidirectional reflectance distribution function (BRDF) models, two popular classes of models are the microfacet model and the linear systems diffraction model. The microfacet model has the benefit of speed and simplicity, as it uses geometric optics approximations, while linear systems theory uses a diffraction approach to compute the BRDF, at the expense of greater computational complexity. In this Letter, nongrazing BRDF measurements of rough and polished surface-reflecting materials at multiple incident angles are scaled by the microfacet cross section conversion term, but in the linear systems direction cosine space, resulting in great alignment of BRDF data at various incident angles in this space. This results in a predictive BRDF model for surface-reflecting materials at nongrazing angles, while avoiding some of the computational complexities in the linear systems diffraction model.

  9. 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

  10. 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.

  11. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Directory of Open Access Journals (Sweden)

    M. De Troch

    2013-06-01

    Full Text Available Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean. Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1 if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2 whether initial (normoxia feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect but also of primary producers (indirect effect, with important implications for the recovery phase.

  12. Experimental study on the performance of a multi-functional domestic air conditioner with integrated water heater

    International Nuclear Information System (INIS)

    Dong, Jiankai; Li, Hui; Yao, Yang; Jiang, Yiqiang; Zhang, Xinran

    2017-01-01

    Highlights: • A novel MDACWH was presented and experimentally studied. • MDACWH has high performance on making domestic hot water and air conditioning. • The time for heating water reduced to 22.0 min after modification. • Average COP reached 4.32, which was 1.58 times higher than the unmodified unit. - Abstract: The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic air conditioner, this paper experimentally studied a multi-functional domestic air conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic air conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.

  13. Experimental Modification of Rat Pituitary Growth Hormone Cell Function During and After Spaceflight

    Science.gov (United States)

    Hymer, W. C.; Salada, T.; Nye, P.; Grossman, E. J.; Lane, P. K.; Grindeland, R. E.

    1996-01-01

    Space-flown rats show a number of flight-induced changes in the structure and function of pituitary Growth Hormone (GH) cells after in vitro postflight testing. To evaluate the possible effects of microgravity on GH cells themselves, freshly dispersed rat anterior pituitary gland cells were seeded into vials containing serum +/- 1 micron HydroCortisone (HC) before flight. Five different cell preparations were used: the entire mixed-cell population of various hormone-producing cell types, cells of density less than 1.071 g/sq cm (band 1), cells of density greater than 1.071 g/sq cm (band 2), and cells prepared from either the dorsal or ventral part of the gland. Relative to ground control samples, bioactive GH released from dense cells during flight was reduced in HC-free medium but was increased in HC-containing medium. Band I and mixed cells usually showed opposite HC-dependent responses. Release of bioactive GH from ventral flight cells was lower; postflight responses to GH-releasing hormone challenge were reduced, and the cytoplasmic area occupied by GH in the dense cells was greater. Collectively, the data show that the chemistry and cellular makeup of the culture system modifies the response of GH cells to microgravity. As such, these cells offer a system to identify gravisensing mechanisms in secretory cells in future microgravity research.

  14. Experimentally induced hyperthyroidism influences oxidant and antioxidant status and impairs male gonadal functions in adult rats.

    Science.gov (United States)

    Asker, M E; Hassan, W A; El-Kashlan, A M

    2015-08-01

    The objective of the present experiment was to study the effect of hyperthyroidism on male gonadal functions and oxidant/antioxidant biomarkers in testis of adult rats. Induction of hyperthyroidism by L-thyroxine (L-T4, 300 μg kg(-1) body weight) treatment once daily for 3 or 8 weeks caused a decrease in body weight gain as well as in absolute genital sex organs weight. The epididymal sperm counts and their motility were significantly decreased in a time-dependent manner following L-T4 treatment. Significant decline in serum levels of luteinising hormone, follicle stimulating hormone and testosterone along with significant increase in serum estradiol level was observed in hyperthyroid rats compared with euthyroid ones. Significant increase in malondialdehyde and nitric oxide concentration associated with significant decrease in superoxide dismutase and catalase activity was also noticed following hyperthyroidism induction. Both reduced glutathione content and glutathione peroxidase activity were increased in hyperthyroid rats compared with control rats. Marked histopathological alterations were observed in testicular section of hyperthyroid rats. These results provide evidence that hypermetabolic state induced by excess level of thyroid hormones may be a causative factor for the impairment of testicular physiology as a consequence of oxidative stress. © 2014 Blackwell Verlag GmbH.

  15. Epigenetic programming of autonomic functions in an experimental model of apnea of prematurity

    Directory of Open Access Journals (Sweden)

    Jayasri Nanduri

    2017-01-01

    Full Text Available Intermittent hypoxia (IH is a hallmark manifestation of recurrent apneas, which is a major clinical problem in infants born preterm. Carotid body (CB chemoreflex and catecholamine (CA secretion from adrenal medullary chromaffin cells (AMCs are two major mechanisms contributing to the maintenance of cardiorespiratory homeostasis during hypoxia. The purpose of this article is to highlight recent studies showing how neonates experiencing IH affect the CB and AMC function and their consequences in adult life. To simulate apneas, rat pups were treated with IH consisting of alternating cycles of hypoxia (1.5% O2 for 15 s and room air for 5 min, 8 h/day from ages P0–P10. Rats treated neonatal IH displayed augmented CB response to hypoxia and augmented CA secretion from AMC. Rats treated for 10 days of IH in the neonatal period were allowed to grow into adulthood. Remarkably, the effects of neonatal IH on CB and AMC persisted in the adulthood. Moreover, adult rats that were exposed to IH in neonatal period exhibited hypertension, increased incidence apnea. Analysis of the underlying molecular mechanisms revealed re-programming of the redox state by epigenetic mechanisms involving suppression of transcription of antioxidant enzyme genes by DNA hypermethylation. DNA hypomethylating agents might offer a novel therapeutic intervention to prevent early onset of cardiorespiratory morbidities caused by neonatal IH.

  16. Numbness in clinical and experimental pain--a cross-sectional study exploring the mechanisms of reduced tactile function.

    Science.gov (United States)

    Geber, Christian; Magerl, Walter; Fondel, Ricarda; Fechir, Marcel; Rolke, Roman; Vogt, Thomas; Treede, Rolf-Detlef; Birklein, Frank

    2008-09-30

    Pain patients often report distinct numbness of the painful skin although no structural peripheral or central nerve lesion is obvious. In this cross-sectional study we assessed the reduction of tactile function and studied underlying mechanisms in patients with chronic pain and in healthy participants exposed to phasic and tonic experimental nociceptive stimulation. Mechanical detection (MDT) and pain thresholds (MPT) were assessed in the painful area and the non-painful contralateral side in 10 patients with unilateral musculoskeletal pain. Additionally, 10 healthy participants were exposed to nociceptive stimulation applied to the volar forearms (capsaicin; electrical stimulation, twice each). Areas of tactile hypaesthesia and mechanical hyperalgesia were assessed. MDT and MPT were quantified adjacent to the stimulation site. Tactile hypaesthesia in pain patients and in experimental pain (MDT-z-scores: -0.66+/-0.30 and -0.42+/-0.15, respectively, both p<0.01) was paralleled by mechanical hyperalgesia (MPT-z-scores: +0.51+/-0.27, p<0.05; and +0.48+/-0.10, p<0.001). However, hypaesthesia and hyperalgesia were not correlated. Although 9 patients reported numbness, only 3 of them were able to delineate circumscript areas of tactile hypaesthesia. In experimental pain, the area of tactile hypaesthesia could be mapped in 31/40 experiments (78%). Irrespective of the mode of nociceptive stimulation (phasic vs. tonic) tactile hypaesthesia and hyperalgesia developed with a similar time course and disappeared within approximately 1 day. Hypaesthesia (numbness) often encountered in clinical pain can be reproduced by experimental nociceptive stimulation. The time course of effects suggests a mechanism involving central plasticity.

  17. 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.

  18. Structural and functional aspects of trypsin–gold nanoparticle interactions: An experimental investigation

    International Nuclear Information System (INIS)

    Nidhin, Marimuthu; Ghosh, Debasree; Yadav, Himanshu; Yadav, Nitu; Majumder, Sudip

    2015-01-01

    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_m_a_x 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.

  19. Nalmefene Reduces Reward Anticipation in Alcohol Dependence: An Experimental Functional Magnetic Resonance Imaging Study.

    Science.gov (United States)

    Quelch, Darren R; Mick, Inge; McGonigle, John; Ramos, Anna C; Flechais, Remy S A; Bolstridge, Mark; Rabiner, Eugenii; Wall, Matthew B; Newbould, Rexford D; Steiniger-Brach, Björn; van den Berg, Franz; Boyce, Malcolm; Østergaard Nilausen, Dorrit; Breuning Sluth, Lasse; Meulien, Didier; von der Goltz, Christoph; Nutt, David; Lingford-Hughes, Anne

    2017-06-01

    Nalmefene is a µ and δ opioid receptor antagonist, κ opioid receptor partial agonist that has recently been approved in Europe for treating alcohol dependence. It offers a treatment approach for alcohol-dependent individuals with "high-risk drinking levels" to reduce their alcohol consumption. However, the neurobiological mechanism underpinning its effects on alcohol consumption remains to be determined. Using a randomized, double-blind, placebo-controlled, within-subject crossover design we aimed to determine the effect of a single dose of nalmefene on striatal blood oxygen level-dependent (BOLD) signal change during anticipation of monetary reward using the monetary incentive delay task following alcohol challenge. Twenty-two currently heavy-drinking, non-treatment-seeking alcohol-dependent males were recruited. The effect of single dose nalmefene (18 mg) on changes in a priori defined striatal region of interest BOLD signal change during reward anticipation compared with placebo was investigated using functional magnetic resonance imaging. Both conditions were performed under intravenous alcohol administration (6% vol/vol infusion to achieve a target level of 80 mg/dL). Datasets from 18 participants were available and showed that in the presence of the alcohol infusion, nalmefene significantly reduced the BOLD response in the striatal region of interest compared with placebo. Nalmefene did not alter brain perfusion. Nalmefene blunts BOLD response in the mesolimbic system during anticipation of monetary reward and an alcohol infusion. This is consistent with nalmefene's actions on opioid receptors, which modulate the mesolimbic dopaminergic system, and provides a neurobiological basis for its efficacy. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. FunGeneNet: a web tool to estimate enrichment of functional interactions in experimental gene sets.

    Science.gov (United States)

    Tiys, Evgeny S; Ivanisenko, Timofey V; Demenkov, Pavel S; Ivanisenko, Vladimir A

    2018-02-09

    Estimation of functional connectivity in gene sets derived from genome-wide or other biological experiments is one of the essential tasks of bioinformatics. A promising approach for solving this problem is to compare gene networks built using experimental gene sets with random networks. One of the resources that make such an analysis possible is CrossTalkZ, which uses the FunCoup database. However, existing methods, including CrossTalkZ, do not take into account individual types of interactions, such as protein/protein interactions, expression regulation, transport regulation, catalytic reactions, etc., but rather work with generalized types characterizing the existence of any connection between network members. We developed the online tool FunGeneNet, which utilizes the ANDSystem and STRING to reconstruct gene networks using experimental gene sets and to estimate their difference from random networks. To compare the reconstructed networks with random ones, the node permutation algorithm implemented in CrossTalkZ was taken as a basis. To study the FunGeneNet applicability, the functional connectivity analysis of networks constructed for gene sets involved in the Gene Ontology biological processes was conducted. We showed that the method sensitivity exceeds 0.8 at a specificity of 0.95. We found that the significance level of the difference between gene networks of biological processes and random networks is determined by the type of connections considered between objects. At the same time, the highest reliability is achieved for the generalized form of connections that takes into account all the individual types of connections. By taking examples of the thyroid cancer networks and the apoptosis network, it is demonstrated that key participants in these processes are involved in the interactions of those types by which these networks differ from random ones. FunGeneNet is a web tool aimed at proving the functionality of networks in a wide range of sizes of

  1. Study of the Neuropeptide Function in Parkinson’s Disease Using the 6-Hydroxydopamine Model of Experimental Hemiparkinsonism

    Directory of Open Access Journals (Sweden)

    I. Banegas

    2017-11-01

    Full Text Available Parkinson’s disease, one of the most common neurodegenerative diseases, characterized by unilateral brain dopamine damage in its initial stages, remains unknown in many respects. It is especially necessary to improve the early diagnosis and, in order to improve the treatment, to go thoroughly into the knowledge of its pathophysiology. To do this, it is essential to perform studies in appropriate animal models of the disease. One of those is generated by the unilateral intracerebral administration of the neurotoxic 6-hydroxydopamine that produces clear asymmetrical cerebral dopamine depletion. Currently the neuronal coexistence of several neurotransmitters is obvious. Particularly interesting is the coexistence of dopamine with various neuropeptides. If the neuronal content of dopamine is asymmetrically altered in the early stages of the Parkinson’s disease, the coexisting neuropeptides may also be asymmetrically altered. Therefore, their study is important to appropriately understand the pathogenesis of the Parkinson’s disease. The function of the neuropeptides can be studied through their metabolism by neuropeptidases whose activity reflects the functional status of their endogenous substrates as well as the one of the peptides resulting from their hydrolysis. Here we review the 6-hydroxydopamine model of experimental hemiparkinsonism as an appropriate model to study the initial asymmetric stages of the disease. In particular, we analyze the consequences of unilateral brain dopamine depletions on the functionality of brain neuropeptides through the study of the activity of cerebral neuropeptidases.

  2. Experimentation of RT-LOTOS for a critical function of a power plant instrumentation and control system

    International Nuclear Information System (INIS)

    Andriantsiiferana, L.; Courtiat, J.P.; De Oliveira, R.C.

    1996-01-01

    This document is the final report of the contract between LAAS-CNRS and the EdF Direction of Researches and Studies about the experimentation of RT-LOTOS formal description technique on a critical function of a nuclear power plant instrumentation and control system. This report comprises 4 parts: part 1 describes the RT-LOTOS (Real Time-Language of Temporal Ordering Specifications) tutorial and its RTL tool environment, the different RT-LOTOS operators and semantics, and the RTL tool main functionalities; part 2 deals with the methodology and the global architecture for the specification and validation of the CCT (Central Calculator for Treatment); part 3 gives more details about the different processes identified in the specification architecture and presents the main results obtained for the validation of the nominal functioning; part 4 describes some exceptional situations and shows how some failures and their associated recovery mechanisms can be modelled. (J.S.). 6 refs., 53 figs., 5 tabs., 2 appends

  3. The First Neurosurgery Boot Camp in Southeast Asia: Evaluating Impact on Knowledge and Regional Collaboration in Yangon, Myanmar.

    Science.gov (United States)

    Rock, Jack; Glick, Roberta; Germano, Isabelle M; Dempsey, Robert; Zervos, John; Prentiss, Tyler; Davis, Matthew; Wright, Ernest; Hlaing, Kyi; Thu, Myat; Soe, Zaw Wai; Myaing, Win

    2018-05-01

    For the first time in Southeast Asia, a Fundamentals of Neurosurgery Boot Camp was held at the University of Medicine 1 in Yangon, Myanmar, February 24-26, 2017. The aim of this course was to teach and train fundamental skills to neurosurgery residents. The Myanmar Neurosurgical Society, Foundation for International Education in Neurosurgery, Society for Neurological Surgeons, The University of Medicine 1 in Yangon, Myanmar, and the Henry Ford Department of Neurosurgery developed a 2-day resident training course. Day 1 activities consisted of lectures by faculty, small group case discussions, and industry-supported demonstrations of surgical techniques. Day 2 activities consisted of hands-on skill stations for common neurosurgical procedures with each station supervised by attending faculty. Written evaluations were distributed before the meeting, immediately after the meeting, and 6 months after the meeting. Boot camp attendees included 40 residents and 24 neurosurgical faculty from Myanmar, Cambodia, Nepal, Singapore, South Korea, Thailand, and Vietnam. There were 35 evaluations completed before the boot camp, 34 completed immediately after boot camp, and 20 completed 6 months after boot camp. Knowledge of participants improved from 62.75% before boot camp to 71.50% 6 months after boot camp (P = 0.046). Boot camps provide fundamental didactic and technical exposure to trainees in developed and developing countries and help standardize training in basic neurosurgical competencies, while exposing local faculty to important teaching methods. This model provides a sustainable solution to educational needs and demonstrates to local neurosurgeons how they can take ownership of the educational process. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. The Bandung neurosurgery patient outcomes project, Indonesia (Part II): Patient pathways and feasibility and acceptability of telephone follow-up.

    Science.gov (United States)

    Sutiono, Agung Budi; Faried, Ahmad; McAllister, Susan; Ganefianty, Amelia; Sarjono, Kalih; Arifin, Muhammad Zafrullah; Derrett, Sarah

    2018-01-01

    Support of neurosurgery patients following discharge from hospital is important. Currently, little is known about patients' in low- and middle-income countries before and after their hospital treatment. This companion paper reports patients' pathways before and after hospital admission and the feasibility of following up this ill-patient population by telephone. Eligible patients were aged ≥18 years admitted to the Neurosurgery Department in Dr. Hasan Sadikin Hospital-a regional referral hospital in Bandung City, Indonesia. Clinical data were collected on admission by clinicians. In-person interviews were undertaken with a clinical research nurse 1 to 2 days pre-discharge, and telephone follow-up interviews at 1, 2, and 3 months post-discharge. Information was also collected on pathways prior to admission and following discharge. The number of contact attempts for each patient interview was documented, as was the overall acceptability of undertaking a telephone interview. Of 178 patients discharged from hospital, 12 later died. Of the remaining 166 patients, 95% were able to be followed up to 3 months. Two-thirds of patients had been referred from another hospital. Patients came from, and were discharged to, locations throughout the West Java region. At the 1-month interview, 84% participants reported that they had had a follow-up consultation with a health professional-mostly with a neurosurgeon. This study has shown that, with a neurosurgery nurse delegated to the role, it is feasible to conduct follow-up telephone interviews with patients after discharge from a neurosurgery ward and that in fact such follow-up was appreciated by patients. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Neurosurgery and prognosis in patients with radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy: a follow-up study

    International Nuclear Information System (INIS)

    Li, Yi; Shi, Xiaolei; Rong, Xiaoming; Peng, Ying; Tang, Yamei

    2013-01-01

    Radiotherapy is the standard radical treatment for nasopharyngeal carcinoma (NPC) and may cause radiation-induced brain injury (RI). Treatment for RI remains a challenge. We conducted this study to investigate the indications of neurosurgery, operation time and prognosis of patients with RI after NPC radiotherapy who underwent neurosurgical management. This was a follow-up study between January 2005 and July 2011. Fifteen NPC cases of RI who underwent neurosurgery were collected. Brain Magnetic resonance imaging (MRI), surgery and histology were studied. The outcome was assessed by LENT/SOMA scales and modified Rankin scale. Brain lesion resection (86.7%) was more common than decompressive craniotomy (13.3%). According to LENT/SOMA scale before and six months after surgery, 13 of 15, 12 of 15, 14 of 15, and 14 of 15 cases showed improvement at subjective, objective, management and analytic domains, respectively. 12 of 15 patients showed improvement of modified Rankin scale after surgery. Three patients who underwent emergency surgery showed significant improvement (average score increment of 2, 2.7, 2.7, 3 and 2 at LENT/SOMA scale subjective, objective, management, analytic, and modified Rankin scale, respectively), as compared with 12 cases underwent elective surgery (average score increment of 1, 1, 1.4, 1.8 and 1 at LENT SOMA scale subjective, objective, management, analytic, and modified Rankin scale, respectively). Neurosurgery, including brain necrotic tissue resection and decompressive craniotomy, improves the prognosis for RI patients, especially for those with indications of emergency surgery

  6. Optimization of multiple performance characteristics in turning using Taguchi’s quality loss function: An experimental investigation

    Directory of Open Access Journals (Sweden)

    Tanmaya Mohanty

    2013-06-01

    Full Text Available Cutting force and chip reduction coefficient is the important index of machinability as it determines the power consumption and amount of energy invested in machining actions. It is primarily influenced by process parameters like cutting speed, feed and depth of cut. This paper presents the application of Taguchi’s parameter design to optimize the parameters for individual responses. For multi-response optimization, Taguchi’s quality loss function approach is proposed. In the present investigation, optimal values of cutting speed, feed and depth of cut are determined to minimize cutting force and chip reduction coefficient during orthogonal turning. The effectiveness of the proposed methodology is illustrated through an experimental investigation in turning mild steel workpiece using high speed steel tool.

  7. 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.

  8. Exocrine and endocrine testicular function during the treatment of experimental orchitis and nonspecific orchoepididymitis by low-energy laser radiation

    Science.gov (United States)

    Reznikov, Leonid L.; Pupkova, Ludmila S.; Bell, H.; Murzin, Alexander G.

    1995-05-01

    Investigations into the biological effects of low-energy laser radiation (LLR) are characterized by a score of challenges, which are due primarily to a cascade of laser-induced and sometimes antagonistic processes. To investigate these processes on various biologic levels, we analyzed local and general effects of LLR on the exocrine and endocrine functions of the accessory sex glands in experimentally induced orchitis and orchoepididymitis in rabbits, and in clinical studies on male patients. The results indicate that LLR may alter the inflammatory response, including the exudative reaction, macrophage migration, and fibroblast activity. Furthermore, LLR may result in changes in serum concentrations of LH, FSH, and ACTH, prolactin, testosterone, cortisol and aldosterone. Some of these changes may be at least partially responsible for the well-known anti-inflammatory effects of LLR.

  9. Colour change in biferroic YCrO_3 under high pressure: a combined experimental and density functional theory investigation

    International Nuclear Information System (INIS)

    Chakraborty, Brahmananda; Mall, Ashish Kumar; Gupta, Rajeev; Chitnis, Abhishek; Garg, Nandini; Ramaniah, Lavanya M.; Sharma, Surinder M.

    2016-01-01

    Biferroic materials find potential applications in various technological fields due to their simultaneous ferroelectric and ferromagnetic ordering. Yttrium chromite (YCrO_3) is found to be a biferroic having orthorhombic structure with Pnma space group. Combining both experiment and density functional theory (DFT), we have investigated the high pressure behaviour of YCrO_3 up to 100 GPa. We have observed a colour change in YCrO_3 from yellow-green to red at pressures larger than 40 GPa, which can be correlated with reduction in band gap under pressure. Present experimental data seems to suggest no structural transition upto 100 GPa. All the calculations are carried out using the DFT based projector augmented wave (PAW) method as implemented in the VASP code. As DFT has a limitation in predicting the correct band gap, we have employed the GGA+U method to compute the band gap. The computed band gap of 2.33 eV in ambient condition is close to the experimental value of 2.4 eV. The X-ray diffraction experiments were carried out in an indigenously designed diamond anvil cell

  10. 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 (pimpulsive 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.

  11. CT-MR image data fusion for computer assisted navigated neurosurgery of temporal bone tumors

    International Nuclear Information System (INIS)

    Nemec, Stefan Franz; Donat, Markus Alexander; Mehrain, Sheida; Friedrich, Klaus; Krestan, Christian; Matula, Christian; Imhof, Herwig; Czerny, Christian

    2007-01-01

    Purpose: To demonstrate the value of multi detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative work up of temporal bone tumors and to present, especially, CT and MR image fusion for surgical planning and performance in computer assisted navigated neurosurgery of temporal bone tumors. Materials and methods: Fifteen patients with temporal bone tumors underwent MDCT and MRI. MDCT was performed in high-resolution bone window level setting in axial plane. The reconstructed MDCT slice thickness was 0.8 mm. MRI was performed in axial and coronal plane with T2-weighted fast spin-echo (FSE) sequences, un-enhanced and contrast-enhanced T1-weighted spin-echo (SE) sequences, and coronal T1-weighted SE sequences with fat suppression and with 3D T1-weighted gradient-echo (GE) contrast-enhanced sequences in axial plane. The 3D T1-weighted GE sequence had a slice thickness of 1 mm. Image data sets of CT and 3D T1-weighted GE sequences were merged utilizing a workstation to create CT-MR fusion images. MDCT and MR images were separately used to depict and characterize lesions. The fusion images were utilized for interventional planning and intraoperative image guidance. The intraoperative accuracy of the navigation unit was measured, defined as the deviation between the same landmark in the navigation image and the patient. Results: Tumorous lesions of bone and soft tissue were well delineated and characterized by CT and MR images. The images played a crucial role in the differentiation of benign and malignant pathologies, which consisted of 13 benign and 2 malignant tumors. The CT-MR fusion images supported the surgeon in preoperative planning and improved surgical performance. The mean intraoperative accuracy of the navigation system was 1.25 mm. Conclusion: CT and MRI are essential in the preoperative work up of temporal bone tumors. CT-MR image data fusion presents an accurate tool for planning the correct surgical procedure and is a

  12. Parental Evaluation of a Nurse Practitioner-Developed Pediatric Neurosurgery Website.

    Science.gov (United States)

    Vogel, Tina Kovacs; Kleib, Manal; Davidson, Sandra J; Scott, Shannon D

    2016-04-12

    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. 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. 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. 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 about the 2 summer camps, (2) explore the Media

  13. Critical assessment of pediatric neurosurgery patient/parent educational information obtained via the Internet.

    Science.gov (United States)

    Garcia, Michael; Daugherty, Christopher; Ben Khallouq, Bertha; Maugans, Todd

    2018-05-01

    OBJECTIVE The Internet is used frequently by patients and family members to acquire information about pediatric neurosurgical conditions. The sources, nature, accuracy, and usefulness of this information have not been examined recently. The authors analyzed the results from searches of 10 common pediatric neurosurgical terms using a novel scoring test to assess the value of the educational information obtained. METHODS Google and Bing searches were performed for 10 common pediatric neurosurgical topics (concussion, craniosynostosis, hydrocephalus, pediatric brain tumor, pediatric Chiari malformation, pediatric epilepsy surgery, pediatric neurosurgery, plagiocephaly, spina bifida, and tethered spinal cord). The first 10 "hits" obtained with each search engine were analyzed using the Currency, Relevance, Authority, Accuracy, and Purpose (CRAAP) test, which assigns a numerical score in each of 5 domains. Agreement between results was assessed for 1) concurrent searches with Google and Bing; 2) Google searches over time (6 months apart); 3) Google searches using mobile and PC platforms concurrently; and 4) searches using privacy settings. Readability was assessed with an online analytical tool. RESULTS Google and Bing searches yielded information with similar CRAAP scores (mean 72% and 75%, respectively), but with frequently differing results (58% concordance/matching results). There was a high level of agreement (72% concordance) over time for Google searches and also between searches using general and privacy settings (92% concordance). Government sources scored the best in both CRAAP score and readability. Hospitals and universities were the most prevalent sources, but these sources had the lowest CRAAP scores, due in part to an abundance of self-marketing. The CRAAP scores for mobile and desktop platforms did not differ significantly (p = 0.49). CONCLUSIONS Google and Bing searches yielded useful educational information, using either mobile or PC platforms. Most

  14. Minimally invasive neurosurgery with interventional magnetic resonance. Its present and future

    International Nuclear Information System (INIS)

    Hashimoto, Takuo

    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 invasive

  15. 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

  16. 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

  17. 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.

  18. In vivo evidence for a functional role of both tumor necrosis factor (TNF) receptors and transmembrane TNF in experimental hepatitis.

    Science.gov (United States)

    Küsters, S; Tiegs, G; Alexopoulou, L; Pasparakis, M; Douni, E; Künstle, G; Bluethmann, H; Wendel, A; Pfizenmaier, K; Kollias, G; Grell, M

    1997-11-01

    The significance of tumor necrosis factor receptor 1 (TNFR1) for TNF function in vivo is well documented, whereas the role of TNFR2 so far remains obscure. In a model of concanavalin A (Con A)-induced, CD4+ T cell-dependent experimental hepatitis in mice, in which TNF is a central mediator of apoptotic and necrotic liver damage, we now provide evidence for an essential in vivo function of TNFR2 in this pathophysiological process. We demonstrate that a cooperation of TNFR1 and TNFR2 is required for hepatotoxicity as mice deficient of either receptor were resistant against Con A. A significant role of TNFR2 for Con A-induced hepatitis is also shown by the enhanced sensitivity of transgenic mice overexpressing the human TNFR2. The ligand for cytotoxic signaling via both TNF receptors is the precursor of soluble TNF, i.e. transmembrane TNF. Indeed, transmembrane TNF is sufficient to mediate hepatic damage, as transgenic mice deficient in wild-type soluble TNF but expressing a mutated nonsecretable form of TNF developed inflammatory liver disease.

  19. Hydrazine functionalized probes for chromogenic and fluorescent ratiometric sensing of pH and F-: experimental and DFT studies.

    Science.gov (United States)

    Roy Chowdhury, Additi; Mondal, Amita; Roy, Biswajit Gopal; K, Jagadeesh C Bose; Mukhopadhyay, Sudit; Banerjee, Priyabrata

    2017-11-08

    Two novel hydrazine based sensors, BPPIH (N 1 ,N 3 -bis(perfluorophenyl)isophthalohydrazide) and BPBIH (N 1' ,N 3' -bis(perfluorobenzylidene)isophthalohydrazide), are presented here. BPPIH is found to be a highly sensitive pH sensor in the pH range 5.0 to 10.0 in a DMSO-water solvent mixture with a pK a value of 9.22. Interesting optical responses have been observed for BPPIH in the above mentioned pH range. BPBIH on the other hand turns out to be a less effective pH sensor in the above mentioned pH range. The increase in fluorescence intensity at a lower pH for BPPIH was explained by using density functional theory. The ability of BPPIH to monitor the pH changes inside cancer cells is a useful application of the sensor as a functional material. In addition fluoride (F - ) selectivity studies of these two chemosensors have been performed and show that between them, BPBIH shows greater selectivity towards F - . The interaction energy calculated from the DFT-D3 supports the experimental findings. The pH sensor (BPPIH) can be further interfaced with suitable circuitry interfaced with desired programming for ease of access and enhancement of practical applications.

  20. 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.

  1. Neurosurgery simulation using non-linear finite element modeling and haptic interaction

    Science.gov (United States)

    Lee, Huai-Ping; Audette, Michel; Joldes, Grand R.; Enquobahrie, Andinet

    2012-02-01

    Real-time surgical simulation is becoming an important component of surgical training. To meet the realtime requirement, however, the accuracy of the biomechancial modeling of soft tissue is often compromised due to computing resource constraints. Furthermore, haptic integration presents an additional challenge with its requirement for a high update rate. As a result, most real-time surgical simulation systems employ a linear elasticity model, simplified numerical methods such as the boundary element method or spring-particle systems, and coarse volumetric meshes. However, these systems are not clinically realistic. We present here an ongoing work aimed at developing an efficient and physically realistic neurosurgery simulator using a non-linear finite element method (FEM) with haptic interaction. Real-time finite element analysis is achieved by utilizing the total Lagrangian explicit dynamic (TLED) formulation and GPU acceleration of per-node and per-element operations. We employ a virtual coupling method for separating deformable body simulation and collision detection from haptic rendering, which needs to be updated at a much higher rate than the visual simulation. The system provides accurate biomechancial modeling of soft tissue while retaining a real-time performance with haptic interaction. However, our experiments showed that the stability of the simulator depends heavily on the material property of the tissue and the speed of colliding objects. Hence, additional efforts including dynamic relaxation are required to improve the stability of the system.

  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. 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.

  4. Rivaling paradigms in psychiatric neurosurgery: adjustability versus quick fix versus minimal-invasiveness.

    Science.gov (United States)

    Müller, Sabine; Riedmüller, Rita; van Oosterhout, Ansel

    2015-01-01

    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 1970s 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.

  5. Accurate multi-robot targeting for keyhole neurosurgery based on external sensor monitoring.

    Science.gov (United States)

    Comparetti, Mirko Daniele; Vaccarella, Alberto; Dyagilev, Ilya; Shoham, Moshe; Ferrigno, Giancarlo; De Momi, Elena

    2012-05-01

    Robotics has recently been introduced in surgery to improve intervention accuracy, to reduce invasiveness and to allow new surgical procedures. In this framework, the ROBOCAST system is an optically surveyed multi-robot chain aimed at enhancing the accuracy of surgical probe insertion during keyhole neurosurgery procedures. The system encompasses three robots, connected as a multiple kinematic chain (serial and parallel), totalling 13 degrees of freedom, and it is used to automatically align the probe onto a desired planned trajectory. The probe is then inserted in the brain, towards the planned target, by means of a haptic interface. This paper presents a new iterative targeting approach to be used in surgical robotic navigation, where the multi-robot chain is used to align the surgical probe to the planned pose, and an external sensor is used to decrease the alignment errors. The iterative targeting was tested in an operating room environment using a skull phantom, and the targets were selected on magnetic resonance images. The proposed targeting procedure allows about 0.3 mm to be obtained as the residual median Euclidean distance between the planned and the desired targets, thus satisfying the surgical accuracy requirements (1 mm), due to the resolution of the diffused medical images. The performances proved to be independent of the robot optical sensor calibration accuracy.

  6. 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.

  7. Patient protection in radiotherapy (Radio neurosurgery National Service of the Social Security Mexican Institute)

    International Nuclear Information System (INIS)

    Espiritu R, R.

    2008-12-01

    The perspective of patient protection at the Radio neurosurgery National Service of the Social Security Mexican Institute is divided into three parts: the testing program for equipment acceptance, an assurance quality program based on periodic tests, an also other assurance quality based on tests during the application. Among the technical aspects that influence in the equipment acceptance tests, it is the collimation type, the characteristics of the lineal accelerator, the platform for planning and the network type. In the case of the collimation system and the accelerator characteristics, we consider the manufacturer's specifications and requirements of Mexican Official Standard NOM-033-NUCL-1999, T echnical Specifications for the Teletherapy Units Operation, Linear Accelerators . Planning for the platform takes into account the manufacturer's specifications. In the case of computed tomography as well as review the calibration according to manufacturer's specifications should be considered the standard NOM-229-SSA1-2002. In the case of the linear accelerator must be the radiological characterization of radiation beam as part of this, the absolute dose determination. As for the periodic tests is verified the dose constancy, as well as the flattening and symmetry of X-rays beam. There are also tests battery with daily, monthly and yearly frequencies, which make up the assurance quality program. (Author)

  8. [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.

  9. Trepanation to Treat a Head Wound: A Case of Neurosurgery from 13th-Century Tuscany.

    Science.gov (United States)

    Riccomi, Giulia; Fornaciari, Gino; Vitiello, Angelica; Bini, Anna; Caramella, Davide; Giuffra, Valentina

    2017-08-01

    During the archaeological excavations conducted in the 13th century cemetery of the Church of Sant'Agostino in Poggibonsi (Tuscany, Italy), a skull with evidence of neurosurgical intervention was brought to light. The skull, belonging to an adult male, shows two traumatic lesions produced by bladed instruments. The first lesion, located on the anterior part of the parietal bones, involved only the outer cranial table; bone remodeling indicates that the individual survived the injury for a long time. The second lesion, located on the frontal bone, involved all the thickness of the bone; the absence of reparative processes allows a diagnosis of peri mortem lesion. To treat this wound, the patient underwent surgical intervention. In fact, in correspondence to the lesion, an oval bone loss, with clean and well-defined cutting edges, can be interpreted as the result of a trepanation, probably performed to clean the wound and to remove any bone splinters. Half of the bone "rondella" was found in situ; it can be hypothesized that the surgeon decided to replace the bony piece to protect the brain. However, the surgical intervention failed, and the patient died soon afterwards. Trepanation for the treatment of cranial traumas is described by several medical classical and medieval authors, whose texts were available in the 13th century. This case represents rare Middle Ages evidence of neurosurgery used to treat a bone injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Full-text automated detection of surgical site infections secondary to neurosurgery in Rennes, France.

    Science.gov (United States)

    Campillo-Gimenez, Boris; Garcelon, Nicolas; Jarno, Pascal; Chapplain, Jean Marc; Cuggia, Marc

    2013-01-01

    The surveillance of Surgical Site Infections (SSI) contributes to the management of risk in French hospitals. Manual identification of infections is costly, time-consuming and limits the promotion of preventive procedures by the dedicated teams. The introduction of alternative methods using automated detection strategies is promising to improve this surveillance. The present study describes an automated detection strategy for SSI in neurosurgery, based on textual analysis of medical reports stored in a clinical data warehouse. The method consists firstly, of enrichment and concept extraction from full-text reports using NOMINDEX, and secondly, text similarity measurement using a vector space model. The text detection was compared to the conventional strategy based on self-declaration and to the automated detection using the diagnosis-related group database. The text-mining approach showed the best detection accuracy, with recall and precision equal to 92% and 40% respectively, and confirmed the interest of reusing full-text medical reports to perform automated detection of SSI.

  11. [Psychiatric disorders in patients with Cushing's disease before and after neurosurgery].

    Science.gov (United States)

    Gnjidiae, Zivko; Karloviae, Dalibor; Buljan, Danijel; Malencia, Masa; Kovak-Mufiae, Ana; Kostanjsak, Lidija

    2011-01-01

    Cushing's disease which is a consequence of ACTH-secreting pituitary adenoma leads to hypercortisolism. Cushing's disease is associated with several psychiatric disturbances. The aim of the present study was to identify which psychiatric disorders were present in patients with Cushing's disease over a 2-year period and to monitor their general psychiatric condition. Additionally, the study aimed to examine the relationship between the duration of Cushing's disease, and the severity of psychiatric conditions based on psychiatric rating scales. The study included 39 patients with Cushing's disease that underwent neurosurgery for ACTH-secreting pituitary adenomas. The transsphenoidal approach (the standard microsurgery technique) was performed in all patients. ACTH-secreting pituitary adenomas were confirmed based on immunohistochemistry in all patients. Psychiatric conditions in the patients were identified using the Clinical Global Impression Scale (CGI) and ICD 10 diagnostic criteria at 3 time points: prior to surgery, and 6 and 48 months post surgery. The Cushing's disease patients exhibited statistically significant improvement in their psychiatric condition, according to the CGI, 6 and 48 months post surgery. There wasn't any significant correlation between the duration of Cushing's disease and psychiatric status, as measured by the CGI prior to surgery, 6 months post surgery, or 48 months post surgery. Patients with Cushing's disease had a significant level psychiatric disturbance that remitted after surgery. There wasn't a significant correlation between the duration of Cushing's disease and psychiatric status.

  12. Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

    Science.gov (United States)

    DePaoli, Damon T.; Lapointe, Nicolas; Goetz, Laurent; Parent, Martin; Prudhomme, Michel; Cantin, Léo.; Galstian, Tigran; Messaddeq, Younès.; Côté, Daniel C.

    2016-03-01

    Deep brain stimulation's effectiveness relies on the ability of the stimulating electrode to be properly placed within a specific target area of the brain. Optical guidance techniques that can increase the accuracy of the procedure, without causing any additional harm, are therefore of great interest. We have designed a cheap optical fiber-based device that is small enough to be placed within commercially available DBS stimulating electrodes' hollow cores and that is capable of sensing biological information from the surrounding tissue, using low power white light. With this probe we have shown the ability to distinguish white and grey matter as well as blood vessels, in vitro, in human brain samples and in vivo, in rats. We have also repeated the in vitro procedure with the probe inserted in a DBS stimulating electrode and found the results were in good agreement. We are currently validating a second fiber optic device, with micro-optical components, that will result in label free, molecular level sensing capabilities, using CARS spectroscopy. The final objective will be to use this data in real time, during deep brain stimulation neurosurgery, to increase the safety and accuracy of the procedure.

  13. Neurosurgery certification in member societies of the World Federation of Neurosurgical Societies: Asia.

    Science.gov (United States)

    Gasco, Jaime; Braun, Jonathan D; McCutcheon, Ian E; Black, Peter M

    2011-01-01

    To objectively compare the complexity and diversity of the certification process in neurological surgery in member societies of the World Federation of Neurosurgical Societies. This study centers in continental Asia. We provide here an analysis based on the responses provided to a 13-item survey. The data received were analyzed, and three Regional Complexity Scores (RCS) were designed. To compare national board experience, eligibility requirements for access to the certification process, and the obligatory nature of the examinations, an RCS-Organizational score was created (20 points maximum). To analyze the complexity of the examination, an RCS-Components score was designed (20 points maximum). The sum of both is presented in a Global RCS score. Only those countries that responded to the survey and presented nationwide homogeneity in the conduction of neurosurgery examinations could be included within the scoring system. In addition, a descriptive summary of the certification process per responding society is also provided. On the basis of the data provided by our RCS system, the highest global RCS was achieved by South Korea and Malaysia (21/40 points) followed by the joint examination of Singapore and Hong-Kong (FRCS-Ed) (20/40 points), Japan (17/40 points), the Philippines (15/40 points), and Taiwan (13 points). The experience from these leading countries should be of value to all countries within Asia. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. "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.

  15. 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.

  16. Acute extradural haematomas in children: A single neurosurgery unit's 12-year experience.

    Science.gov (United States)

    Enicker, B; Louw, H; Madiba, T

    2016-11-01

    Acute extradural haematomas (AEDHs) occur infrequently in children. This study was undertaken to review our experience with management and outcomes of this condition in children treated in the Neurosurgery Unit at Inkosi Albert Luthuli Central Hospital. A retrospective review of medical records of all children (age less than or equal to (≤) 12 years) with a diagnosis of AEDH admitted from January 2003 to December 2014 was performed. Records were analyzed for demographics, mechanisms of injury, clinical presentation, neuroradiology findings, management and outcomes at discharge. A total of 150 children with AEDHs were admitted during this period. The mean age was 6.6 ± 3.8 years with a peak incidence in the 7-9 year age group. There were 84 (56%) males, (M: F= 1.3:1). Sixty AEDHs resulted from road traffic crashes (40%). On admission 104 (69.3%) children were Glasgow coma scale (GCS) 13-15, 26 (17.3%) GCS 9-12 and 20 (13.4%) GCS 3-8. Haemoglobin was less than (children and the mean hospital stay was 6.9 ± 6.1 days. Four children (2.7%) died during in-hospital stay period. One hundred and forty one (94%) children had a favourable Glasgow outcome scale (GOS) at discharge. AEDHs in children carry a good prognosis, but can be potentially fatal. A vigilant approach is required when assessing these children, as early diagnosis and treatment yields gratifying results.

  17. Granulocyte Colony-Stimulating Factor Combined with Methylprednisolone Improves Functional Outcomes in Rats with Experimental Acute Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    William Gemio Jacobsen Teixeira

    2018-02-01

    Full Text Available OBJECTIVES: To evaluate the effects of combined treatment with granulocyte colony-stimulating factor (G-CSF and methylprednisolone in rats subjected to experimental spinal cord injury. METHODS: Forty Wistar rats received a moderate spinal cord injury and were divided into four groups: control (no treatment; G-CSF (G-CSF at the time of injury and daily over the next five days; methylprednisolone (methylprednisolone for 24 h; and G-CSF/Methylprednisolone (methylprednisolone for 24 h and G-CSF at the time of injury and daily over the next five days. Functional evaluation was performed using the Basso, Beattie and Bresnahan score on days 2, 7, 14, 21, 28, 35 and 42 following injury. Motor-evoked potentials were evaluated. Histological examination of the spinal cord lesion was performed immediately after euthanasia on day 42. RESULTS: Eight animals were excluded (2 from each group due to infection, a normal Basso, Beattie and Bresnahan score at their first evaluation, or autophagy, and 32 were evaluated. The combination of methylprednisolone and G-CSF promoted greater functional improvement than methylprednisolone or G-CSF alone (p<0.001. This combination also exhibited a synergistic effect, with improvements in hyperemia and cellular infiltration at the injury site (p<0.001. The groups displayed no neurophysiological differences (latency p=0.85; amplitude p=0.75. CONCLUSION: Methylprednisolone plus G-CSF promotes functional and histological improvements superior to those achieved by either of these drugs alone when treating spinal cord contusion injuries in rats. Combining the two drugs did have a synergistic effect.

  18. 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...

  19. 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

  20. Redox Chemistry of Bis(pyrrolyl)pyridine Chromium and Molybdenum Complexes: An Experimental and Density Functional Theoretical Study.

    Science.gov (United States)

    Gowda, Anitha S; Petersen, Jeffrey L; Milsmann, Carsten

    2018-02-19

    The three- and four-membered redox series [Cr( Me PDP) 2 ] z (z = 1-, 2-, 3-) and [Mo( Me PDP) 2 ] z (z = 0, 1-, 2-, 3-) were synthesized to study the redox properties of the pincer ligand Me PDP 2- (H 2 Me PDP = 2,6-bis(5-methyl-3-phenyl-1H-pyrrol-2-yl)pyridine). The monoanionic complexes were characterized by X-ray crystallography, UV/vis/NIR spectroscopy, and magnetic susceptibility measurements. Experimental and density functional theory (DFT) studies are consistent with closed-shell Me PDP 2- ligands and +III oxidation states (d 3 , S = 3/2) for the central metal ions. Cyclic voltammetry established multiple reversible redox processes for [M( Me PDP) 2 ] 1- (M = Cr, Mo), which were further investigated via chemical oxidation and reduction. For molybdenum, one-electron oxidation yielded Mo( Me PDP) 2 which was characterized by X-ray crystallography, UV/vis/NIR, and magnetic susceptibility measurements. The experimental and computational data indicate metal-centered oxidation to a Mo IV complex (d 2 , S = 1) with two Me PDP 2- ligands. In contrast, one- and two-electron reductions were found to be ligand centered resulting in the formation of Me PDP •3- radicals, in which the unpaired electron is predominantly located on the central pyridine ring of the ligand. The presence of ligand radicals was established experimentally by observation of ligand-to-ligand intervalence charge transfer (LLIVCT) bands in the UV/vis/NIR spectra of the dianionic and trianionic complexes and further supported by broken-symmetry DFT calculations. X-ray crystallographic analyses of the one-electron-reduced species [M( Me PDP) 2 ] 2- (S = 1, M = Cr, Mo) established structural indicators for pincer reduction and showed localization of the radical on one of the two pincer ligands.