Message-Passing Receivers for Single Carrier Systems with Frequency-Domain Equalization

DEFF Research Database (Denmark)

Zhang, Chuanzong; Manchón, Carles Navarro; Wang, Zhongyong

2015-01-01

In this letter, we design iterative receiver algorithms for joint frequency-domain equalization and decoding in a single carrier system assuming perfect channel state information. Based on an approximate inference framework that combines belief propagation (BP) and the mean field (MF) approximation......, we propose two receiver algorithms with, respectively, parallel and sequential message-passing schedules in the MF part. A recently proposed receiver based on generalized approximate message passing (GAMP) is used as a benchmarking reference. The simulation results show that the BP-MF receiver...

The utility of first-pass perfusion CT in hyperacute ischemic stroke: early experience

International Nuclear Information System (INIS)

Lee, Tae Jin; Lee, Myeong Sub; Kim, Myung Soon; Hong, In Soo; Lee, Young Han; Lee, Ji Yong; Whang, Kum

2003-01-01

To evaluate the findings of first-pass perfusion CT in hyperacute stroke patients and to determine the relationship between a perfusion map and final infarct outcome. Thirty-five patients admitted with ischemic stroke within six hours of the onset of symptoms underwent conventional cerebral CT immediately followed by first-pass perfusion CT. Nineteen underwent follow-up CT or MRI, and three types of dynamic perfusion map-cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) - were evaluated by two radiologists. In these 19 patients, initial perfusion maps correlated with final infarct size, determined during follow-up studies. In all 35 patients, major large vessel perfusion abnormalities [middle cerebral artery - MCA MCA and anterior cerebral artery - ACA (n=2); posterior cerebral artery - PCA (n=8)] were detected. On first-pass perfusion maps depicting CBF and MTT, all lesions were detected, and CBF and delayed MTT values were recorded. CBV maps showed variable findings. In all 19 patients who were followed up, the final infarct size of perfusion abnormalities was less than that depicted on CBF and MTT maps, and similar to or much greater than that seen on CBV maps. First-pass perfusion CT scanning is a practical, rapid and advanced imaging technique. In hyperacute stroke patients, it provides important and reliable hemodynamic information as to which brain tissue is salvageable by thrombolytic therapy, and predicts outcome of such treatment

Protective effects of alkaloid extract from Leonurus heterophyllus on cerebral ischemia reperfusion injury by middle cerebral ischemic injury (MCAO) in rats.

Science.gov (United States)

Liang, Hao; Liu, Ping; Wang, Yunshan; Song, Shuliang; Ji, Aiguo

2011-07-15

The neuronal damage following cerebral ischemia is a serious risk to stroke patients. The aim of this study was to investigate the neuroprotective effects of alkaloid extract from Leonurus heterophyllus (LHAE) on cerebral ischemic injury. After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), some rats were intraperitoneally administered different doses of LHAE (3.6, 7.2, 14.4 mg/kg, respectively). Neurological examination was measured in all animals. Infarct volume, myeloperoxidase (MPO) activity, levels of nitrate/nitrite metabolite (NO) and apoptosis ratio of nerve fiber in brain were determined. The results showed that LHAE at 7.2 mg/kg or 14.4 mg/kg exerted significantly decreasing neurological deficit scores and reducing the infarct volume on rats with focal cerebral ischemic injury (pagent. Further studies are warranted to assess the efficacy and safety of LHAE in patients. Copyright © 2011 Elsevier GmbH. All rights reserved.

Cerebral blood flow and cerebral oxygen metabolism in thalamic hemorrhage

International Nuclear Information System (INIS)

Yasui, Nobuyuki; Asakura, Ken

1987-01-01

Cerebral blood flow (CBF), cerebral oxygen consumption (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood volume (CBV) were studied in 20 cases of thalamic hemorrhage using positron CT and 15 O labeled gas steady-state inhalation method. CBF reduction was limited around the thalamus in the small sized hematoma. CBF were significantly diminished in the mean cortical, parietal, temporal, basal ganglia and thalamic area ipsilateral and cerebellar cortex contralateral to the medium sized hematoma. There was bilateral and diffuse CBF reduction in the large sized hematoma which was caused by increased intracranial pressure. CMRO 2 value were similary changed as CBF. OEF change showed within normal limit. Diffuse CBV reduction was observed in the large sized hematoma. This reduction was the result of decreased vascular bed caused by mass effect of the hematoma and hydrocephalus. Effect of surgical treatment such as ventricular drainage and hematoma evacuation were also discussed in correlation to CBF in some case using positron and single photon ECT. (author)

Antioxidant Activity of Grapevine Leaf Extracts against Oxidative Stress Induced by Carbon Tetrachloride in Cerebral Cortex, Hippocampus and Cerebellum of Rats

Directory of Open Access Journals (Sweden)

Mariane Wohlenberg

2014-04-01

Full Text Available In recent years, it has become increasingly important to study the beneficial properties of derivatives of grapes and grapevine. The objective of this study was to determine the antioxidant activity of Vitis labrusca leaf extracts, comparing conventional and organic grapevines, in different brain areas of rats. We used male Wistar rats treated with grapevine leaf extracts for a period of 14 days, and on the 15th day, we administered in half of the rats, mineral oil and the other half, carbon tetrachloride (CCl4. The animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were removed to assess oxidative stress parameters and the activity of antioxidant enzymes. Lipid peroxidation levels (TBARS were unchanged. However, CCl4 induced oxidative damage to proteins in all tissues studied, and this injury was prevented by both extracts. Superoxide dismutase (SOD activity was increased by CCl4 in the cerebral cortex and decreased in other tissues. However, CCl4 increased catalase (CAT activity in the cerebellum and decreased it in the cerebral cortex. The SOD/CAT ratio was restored in the cerebellum by both extracts and only in the cerebral cortex by the organic extract.

Single-pass BPM system of the Photon Factory storage ring.

Science.gov (United States)

Honda, T; Katoh, M; Mitsuhashi, T; Ueda, A; Tadano, M; Kobayashi, Y

1998-05-01

At the 2.5 GeV ring of the Photon Factory, a single-pass beam-position monitor (BPM) system is being prepared for the storage ring and the beam transport line. In the storage ring, the injected beam position during the first several turns can be measured with a single injection pulse. The BPM system has an adequate performance, useful for the commissioning of the new low-emittance lattice. Several stripline BPMs are being installed in the beam transport line. The continuous monitoring of the orbit in the beam transport line will be useful for the stabilization of the injection energy as well as the injection beam orbit.

Protective Effect of Extract of Folium Ginkgo on Repeated Cerebral Ischemia-Reperfusion Injury

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

Objective: To study the protective effect of extract of Folium Ginkgo (FGE) on repeated cerebral ischemia-reperfusion injury. Methods: The model in waking mice induced by repeated cerebral ischemia-reperfusion were used in the experiment to observe the effect of FGE on behavior, oxygen free radical metabolism and prostaglandin E2 (PGE2) content by step-through experiment, diving stand and colorimetric method. Results: FGE could obviously improve the learning ability and memory of model animals, and could lower obviously the content of malonyldialdehyde, nitric oxide and PGE2, restore the lowered activity of superoxide dismutase and catalase in cerebral tissue. Conclusion: FGE has highly protective effect against repeated ischemia-reperfusion injury, the mechanism might be related with its action on anti-lipid oxidatin, improve the activity of antioxidase and inhibit the producing of PGE2.

Double Pass 595?nm pulsed dye laser at a 6 minute interval for the treatment of port-wine stains is not more effective than single pass

NARCIS (Netherlands)

Peters, M. A. D.; van Drooge, A. M.; Wolkerstorfer, A.; van Gemert, M. J. C.; van der Veen, J. P. W.; Bos, J. D.; Beek, J. F.

2012-01-01

Background Pulsed dye laser (PDL) is the first choice for treatment of port wine stains (PWS). However, outcome is highly variable and only a few patients achieve complete clearance. The objective of the study was to compare efficacy and safety of single pass PDL with double pass PDL at a 6 minute

N-isopropyl-[123I]p-iodoamphetamine: single-pass brain uptake and washout; binding to brain synaptosomes; and localization in dog and monkey brain

International Nuclear Information System (INIS)

Winchell, H.S.; Horst, W.D.; Braun, L.; Oldendorf, W.H.; Hattner, R.; Parker, H.

1980-01-01

The kinetics of N-isopropyl-p-[ 123 I]iodoamphetamine in rat brains were determined by serial measurements of brain uptake index (BUI) after intracarotid injection; also studied were its effects on amine uptake and release in rat's brain cortical synaptosomes; and its in vivo distribution in the dog and monkey. No specific localization in brain nuclei of the dog was seen, but there was progressive accumulation in the eyes. Rapid initial brain uptake in the ketamine-sedated monkey was noted, and further slow brain uptake occurred during the next 20 min but without retinal localization. High levels of brain activity were maintained for several hours. The quantitative initial single-pass clearance of the agent in the brain suggests its use in evaluation of regional brain perfusion. Its interaction with brain amine-binding sites suggests its possible application in studies of cerebral amine metabolism

Model for Estimation of Thermal History Produced by a Single Pass Underwater Wet Weld

National Research Council Canada - National Science Library

Dill, Jay

1997-01-01

Thermal history calculations for single pass underwater wet weldments were made by solving the appropriate beat transfer equations using the three-dimensional Crank-Nicholson finite difference method...

Nepeta Dschuparensis Bornm Extract Moderates COX-2 and IL-1β Proteins in a Rat Model of Cerebral Ischemia

Directory of Open Access Journals (Sweden)

Alireza Mousavi Nia

2017-03-01

Full Text Available Background: Nepeta dschuparensis Bornm (NP is used as a medicinal herb in Iran. In traditional medicine, this herb is extensively employed for curing ailments such as cardiovascular diseases. NP has antioxidant and anti-inflammatory properties. This project examined the effects of the NP extract on cyclooxygenase-2 (COX-2 and interleukin-1β (IL-1β protein levels and its efficacy in neuroprotection in a cerebral ischemia-reperfusion model. Methods: Twenty-six male rats were randomly divided into 3 groups: 1 sham (n=6: no middle cerebral artery occlusion (MCAO procedure, 2 control (n=10: MCAO procedure and treatment with normal saline, and 3 NP extract (n=10: MCAO procedure and treatment with the NP extract (20 mg/kg, i.p. at the beginning of reperfusion. To examine the injury caused by cerebral ischemia, we measured motor coordination and the infarct area using the rotarod test and triphenyl tetrazolium chloride staining, respectively. IL-1β and COX-2 protein levels, as inflammatory markers, were measured by immunoblotting assay. The statistical analyses were performed using SPSS, version 16, and the data are expressed as means±SEMs. Statistical difference was evaluated using the one-way ANOVA, followed by the post hoc LSD test (P<0.01. Results: Treatment with the NP extract significantly diminished the infarct volume and alleviated the motor coordination disorder induced by cerebral ischemia. The NP extract administration significantly attenuated the increase in IL-1β and COX-2 protein levels too (P<0.01. Conclusion: The beneficial effects of the NP extract are related to its ability to decrease the levels of IL-1β and COX-2.

Extraction of water labeled with oxygen 15 during single-capillary transit. Influence of blood pressure, osmolarity, and blood-brain barrier damage

International Nuclear Information System (INIS)

Go, K.G.; Lammertsma, A.A.; Paans, A.M.; Vaalburg, W.; Woldring, M.G.

1981-01-01

By external detection, the influence of arterial blood pressure (BP), osmolarity, and cold-induced blood-brain barrier damage was assessed on the extraction of water labeled with oxygen 15 during single-capillary transit in the rat. There was an inverse relation between arterial BP and extraction that was attributable to the influence of arterial BP on cerebral blood flow (CBF) and the relation between CBF and extraction. Neither arterial BP nor osmolarity of the injected bolus had any direct effect on extraction of water 15O, signifying that the diffusional exchange component (determined by blood flow) of extraction greatly surpasses the convection flow contribution by hydrostatic or osmotic forces. Damage to the blood-brain barrier did not change its permeability to water

Evaluation of single-walled carbon nanohorns as sorbent in dispersive micro solid-phase extraction

Energy Technology Data Exchange (ETDEWEB)

Jimenez-Soto, Juan Manuel; Cardenas, Soledad [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain); Valcarcel, Miguel, E-mail: qa1meobj@uco.es [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain)

2012-02-10

Highlights: Black-Right-Pointing-Pointer The potential of single walled carbon nanohorns in dispersive solid phase microextraction has been evaluated. Black-Right-Pointing-Pointer The method was characterized for the extraction of PAHs from waters. Black-Right-Pointing-Pointer Single walled carbon nanohorns were better extractant than carbon nanotubes and carbon nanocones. Black-Right-Pointing-Pointer The limits of detection were adequate for the target analytes in environmental waters. - Abstract: A new dispersive micro solid-phase extraction method which uses single-walled carbon nanohorns (SWNHs) as sorbent is proposed. The procedure combines the excellent sorbent properties of the nanoparticles with the efficiency of the dispersion of the material in the sample matrix. Under these conditions, the interaction with the analytes is maximized. The determination of polycyclic aromatic hydrocarbons was selected as model analytical problem. Two dispersion strategies were evaluated, being the functionalization via microwave irradiation better than the use of a surfactant. The extraction was accomplished by adding 1 mL of oxidized SWHNs (o-SWNHs) dispersion to 10 mL of water sample. After extraction, the mixture was passed through a disposable Nylon filter were the nanoparticles enriched with the PAHs were retained. The elution was carried out with 100 {mu}L of hexane. The limits of detection achieved were between 30 and 60 ng L{sup -1} with a precision (as repeatability) better than 12.5%. The recoveries obtained for the analytes in three different water samples were acceptable in all instances. The performance of o-SWNHs was favourably compared with that provided by carboxylated single-walled carbon nanotubes and thermally treated carbon nanocones.

Cerebral staging of lung cancer: is one single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence sufficient?

Energy Technology Data Exchange (ETDEWEB)

Ohana, Mickael; Jeung, Mi-Young; Roy, Catherine [Nouvel Hopital Civil-Hopitaux Universitaires de Strasbourg, Service de Radiologie B/Radiology Department, Strasbourg (France); Bazille, Gauthier [Clinique Saint Anne-Groupe Radiologique MIM, Strasbourg (France)

2014-08-15

Gadolinium-enhanced magnetic resonance imaging (MRI) is the gold standard for cerebral staging in thoracic oncology. We hypothesize that a minimalist examination, consisting of a single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence (CE 3D-GRE), would be sufficient for the cerebral staging of nonsymptomatic lung cancer patients. Seventy nonsymptomatic patients (50 % men; 62 years ± 10.2) referred for cerebral staging of a lung cancer were retrospectively included. All underwent a standard 3 T MRI examination with T1, FLAIR, T2* GRE, diffusion, and CE 3D-GRE sequences, for a total examination time of 20 min. The sole CE 3D-GRE (acquisition time: 6 min) was extracted and blindly interpreted by two radiologists in search of brain metastases. Hemorrhagic features of potential lesions and relevant incidental findings were also noted. Discrepant cases were reviewed by a third reader. The full MRI examination and follow-up studies were used as a reference to calculate sensitivity and specificity of the sole CE 3D-GRE. Thirty-eight point six percent (27 out of 70) of the patients had brain metastases. Performances and reader's agreement with the sole CE 3D-GRE sequence were excellent for the diagnosis of brain metastases (sensitivity = 96.3 %, specificity = 100 %, κ = 0.91) and incidental findings (sensitivity = 85.7 %, specificity = 100 %, κ = 0.62) but insufficient for the identification of hemorrhages within the metastases (sensitivity = 33.3 %, specificity = 85.7 %, κ = 0.47). In the specific case of lung cancer, cerebral staging in nonsymptomatic patients can be efficiently achieved with a minimalistic protocol consisting of a single CE 3D-GRE sequence, completed if positive with a T2* sequence for hemorrhagic assessment, thus halving appointment delays. (orig.)

Cerebral tissue oxygen saturation and extraction in preterm infants before and after blood transfusion

NARCIS (Netherlands)

van Hoften, Jacorina C. R.; Verhagen, Elise A.; Keating, Paul; ter Horst, Hendrik J.; Bos, Arend F.

Objective Preterm infants often need red blood cell (RBC) transfusions. The aim of this study was to determine whether haemoglobin levels before transfusion were associated with regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) and whether RBC

Physicochemical properties of bio-oil and biochar produced by fast pyrolysis of stored single-pass corn stover and cobs.

Science.gov (United States)

Shah, Ajay; Darr, Matthew J; Dalluge, Dustin; Medic, Dorde; Webster, Keith; Brown, Robert C

2012-12-01

Short harvest window of corn (Zea mays) stover necessitates its storage before utilization; however, there is not enough work towards exploring the fast pyrolysis behavior of stored biomass. This study investigated the yields and the physicochemical properties (proximate and ultimate analyses, higher heating values and acidity) of the fast pyrolysis products obtained from single-pass stover and cobs stored either inside a metal building or anaerobically within plastic wraps. Biomass samples were pyrolyzed in a 183 cm long and 2.1cm inner diameter free-fall fast pyrolysis reactor. Yields of bio-oil, biochar and non-condensable gases from different biomass samples were in the ranges of 45-55, 25-37 and 11-17 wt.%, respectively, with the highest bio-oil yield from the ensiled single-pass stover. Bio-oils generated from ensiled single-pass cobs and ensiled single-pass stover were, respectively, the most and the least acidic with the modified acid numbers of 95.0 and 65.2 mg g(-1), respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Results of single-event multilevel orthopedic surgery in children with cerebral palsy

Directory of Open Access Journals (Sweden)

Akhmed Tomov

2015-11-01

Full Text Available Background: Single-event multilevel orthopedic surgery is a modern approach in the operative treatment of children with cerebral palsy. Methods: Single-event multilevel orthopedic surgery was carried out in 108 patients with cerebral palsy. Patients’ average age was 11.3±1.7 years. Surgical results were analyzed at follow-up after 18 to 24 months, by way of detailed physical examination, functional assessment, imaging, the Edinburgh Visual Gait Score and Gillette Functional Assessment Questionnaire. Results: In our series, 647 procedures were performed during 141 surgeries. Patients had an average of 4.59 procedures per surgery. Observational gait analysis showed an improvement in stance and swing gait phases in ambulatory children. According to the Gillette Functional Assessment Questionnaire, an increase of functional level was noted in 50 patients but did not change in 32 patients. Conclusions: For children with cerebral palsy, single-event multilevel surgery is defined as two or more surgical procedures of the soft tissue or bone at two or more anatomical levels during one operative procedure. In cases where a large volume of surgery is required, two separate operations with a short break in between, but requiring only one hospital admission and one rehabilitation period, are also included. This approach requires adapted methods of surgical intervention, and appropriate methods of anesthesia and pain control in the postoperative period to the start of rehabilitation. Compliance with the above principles allowed the necessary correction of orthopedic complications to be achieved in all cases.

Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction.

Science.gov (United States)

Fogel, Mark A; Li, Christine; Elci, Okan U; Pawlowski, Tom; Schwab, Peter J; Wilson, Felice; Nicolson, Susan C; Montenegro, Lisa M; Diaz, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2017-02-14

Patients with a single ventricle experience a high rate of brain injury and adverse neurodevelopmental outcome; however, the incidence of brain abnormalities throughout surgical reconstruction and their relationship with cerebral blood flow, oxygen delivery, and carbon dioxide reactivity remain unknown. Patients with a single ventricle were studied with magnetic resonance imaging scans immediately prior to bidirectional Glenn (pre-BDG), before Fontan (BDG), and then 3 to 9 months after Fontan reconstruction. One hundred sixty-eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age, 4.8±1.7 months), 118 BDG (2.9±1.4 years), and 54 after Fontan (2.4±1.0 years). Nonacute ischemic white matter changes on T2-weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontan compared with pre-BDG patients ( P <0.05). BDG patients had significantly higher cerebral blood flow than did Fontan patients. The odds of discovering brain injury with adjustment for surgical stage as well as ≥2 coexisting lesions within a patient decreased (63%-75% and 44%, respectively) with increasing amount of cerebral blood flow ( P <0.05). In general, there was no association of oxygen delivery (except for ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Significant brain abnormalities are commonly present in patients with a single ventricle, and detection of these lesions increases as children progress through staged surgical reconstruction, with multiple coexisting lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater cerebral blood flow than did Fontan patients and that an inverse association exists of various indexes of cerebral blood flow with these brain lesions. However, CO 2 reactivity and oxygen delivery (with 1 exception) were not associated with brain lesion development. URL: http

Development of radioiodinated receptor ligands for cerebral single photon emission tomography

International Nuclear Information System (INIS)

Knapp, F.F. Jr.; McPherson, D.W.

1992-01-01

In the last decade the use of radiolabeled ligands for the imaging of cerebral receptors by emission computed tomography (ECT) has seen rapid growth. The opportunity to routinely perform cerebral single photon emission tomography (SPET) with iodine-123-labeled ligands depends on the availability of receptor ligands into which iodine can be introduced without decreasing the required high target receptor specificity. The use of iodine-123-labeled receptor-specific ligands also depends on the availability of high purity iodine-123 at reasonable costs and the necessary imaging instrumentation. In this paper, the development and current stage of evaluation of various iodine-123-labeled ligands for SPET imaging of dopaminergic, serotonergic and muscarinic acetylcholinergic receptor classes are discussed

A clinical study of cerebral vaso paralysis during a period of cerebral vasospasm after subarachnoid hemorrhage

International Nuclear Information System (INIS)

Watanabe, Toshiichi; Sasaki, Takehiko; Nakagawara, Jyoji

2011-01-01

We employ the 123 I-infinitum (Imp) single photon emission computed tomography (SPECT) dual table autoradiography (Arg) method and stereotactic extraction estimation (SEE) analysis 7 or 8 days after subarachnoid hemorrhage (SAH) onset to predict cerebral vasospasm. We report new findings of cerebral vasoparalysis during a period of cerebral vasospasm after SAH. From January 1, 2005 to April 30, 2008, we encountered 330 cases of aneurysmal SAH, and treated 285 cases. Of these, 65 were excluded as unsuitable for this study, for reasons such as lack of SPECT data, external decompression, admission over 7 days from SAH onset. We studied 220 cases treated by microsurgical clipping (n=178) or endovascular coil embolization (n=42). Vasoparalysis was defined as a rise in resting cerebral blood flow (CBF) and a loss of vascular reserve on SEE analysis of CBF-SPECT. Vasoparalysis occurred in 15 cases (6.8%). Of these, 9 cases (60.0%) had cerebral hematoma, temporary clips had been used in the operation for 8 cases (53.3%), 9 cases (60.0%) experienced postoperative cerebral infarction, and 3 cases (20.0%) had postoperative convulsions. Vasoparalysis occurs in relation to perioperative cerebral damage. In terms of the loss of vascular reserve following SAH, vasoparalysis resembles hemodynamic cerebral ischemia, although the conditions are quite different. Differentiating between these 2 conditions is important, as different forms of management are required. Dual table ARG and SEE analysis are very useful for the evaluating these 2 conditions. (author)

Evaluation of regional pulmonary blood flow in mitral valvular heart disease using single-pass radionuclide angiocardiography

International Nuclear Information System (INIS)

Chang-Soon Koh; Byung Tae Kim; Myung Chul Lee; Bo Yeon Cho

1982-01-01

Pulmonary hypertension in mitral valvular cardiac disease has been evaluated in 122 patients by a modified upper lung/lower count ratio using single-pass radionuclide angiocardiography. The mean upper lung/lower lung radio correlates well with pulmonary artery mean (r=0.483) and wedge pressure (r=0.804). After correction surgery of the cardiac valve, the ratio decreases and returns to normal range in patients judged clinically to have good surgical benifit. This modified method using single-pass technique provides additional simple, reproducible and nontraumatic results of regional pulmonary blood flow and appears to be correlated with the degree of pulmonary hypertension in mitral heart disease

Extractables analysis of single-use flexible plastic biocontainers.

Science.gov (United States)

Marghitoiu, Liliana; Liu, Jian; Lee, Hans; Perez, Lourdes; Fujimori, Kiyoshi; Ronk, Michael; Hammond, Matthew R; Nunn, Heather; Lower, Asher; Rogers, Gary; Nashed-Samuel, Yasser

2015-01-01

Studies of the extractable profiles of bioprocessing components have become an integral part of drug development efforts to minimize possible compromise in process performance, decrease in drug product quality, and potential safety risk to patients due to the possibility of small molecules leaching out from the components. In this study, an effective extraction solvent system was developed to evaluate the organic extractable profiles of single-use bioprocess equipment, which has been gaining increasing popularity in the biopharmaceutical industry because of the many advantages over the traditional stainless steel-based bioreactors and other fluid mixing and storage vessels. The chosen extraction conditions were intended to represent aggressive conditions relative to the application of single-use bags in biopharmaceutical manufacture, in which aqueous based systems are largely utilized. Those extraction conditions, along with a non-targeted analytical strategy, allowed for the generation and identification of an array of extractable compounds; a total of 53 organic compounds were identified from four types of commercially available single-use bags, the majority of which are degradation products of polymer additives. The success of this overall extractables analysis strategy was reflected partially by the effectiveness in the extraction and identification of a compound that was later found to be highly detrimental to mammalian cell growth. The usage of single-use bioreactors has been increasing in biopharmaceutical industry because of the appealing advantages that it promises regarding to the cleaning, sterilization, operational flexibility, and so on, during manufacturing of biologics. However, compared to its conventional counterparts based mainly on stainless steel, single-use bioreactors are more susceptible to potential problems associated with compound leaching into the bioprocessing fluid. As a result, extractable profiling of the single-use system has become

Salvia miltiorrhiza Bunge (Danshen) extract attenuates permanent cerebral ischemia through inhibiting platelet activation in rats.

Science.gov (United States)

Fei, Yu-Xiang; Wang, Si-Qi; Yang, Li-Jian; Qiu, Yan-Ying; Li, Yi-Ze; Liu, Wen-Yuan; Xi, Tao; Fang, Wei-Rong; Li, Yun-Man

2017-07-31

Danshen is a crude herbal drug isolated from dried roots of Salvia miltiorrhiza Bunge. This plant is widely used in oriental medicine for the treatment of cardiovascular and cerebrovascular diseases. The supercritical CO 2 extract from Danshen (SCED) (57.85%, 5.67% and 4.55% for tanshinone IIA, tanshinone I and cryptotanshinone respectively) was studied in this article, whose potential molecular mechanism remains unclear, especially in anti-thrombosis. The present study was designed to observe the protective effect of SCED on ischemic stroke in rats and to explore the underlying anti-thrombosis mechanism. Following induction of cerebral ischemia in rats by permanent middle cerebral artery occlusion (pMCAO). Neurological defect score, cerebral blood flow, infarct size, and brain edema were measured to evaluate the injury. Arteriovenous shunt thrombosis model and adenosine 5'-diphosphate (ADP) induced acute pulmonary embolism model were conducted to estimate the antithrombotic effect of SCED. In order to investigate the effects of SCED on platelet aggregation, rat platelet-rich-plasma (PRP) were incubated with SCED prior to the addition of the stimuli (ADP or 9, 11-dideoxy-11α, 9α-epoxymethanoprostaglandin F2α (U46619)). Aggregation was monitored in a light transmission aggregometer. Inhibitory effect of SCED on thromboxane A2 (TXA 2 ) release was detected by ELISA kit. Phospholipase C (PLC)/ Protein kinase C (PKC) signaling pathway was analyzed by a Western blot technique. The effect of the SCED was also studied in vivo on bleeding time in mice. SCED improved the neurological defect score, increased cerebral blood flow, reduced infarct size and alleviated brain edema in rats exposed to pMCAO. After administration of SCED, thrombosis formation in arteriovenous shunt was inhibited and recovery time in pulmonary embolism was shortened. The inhibitory effect of SCED on platelet activation was further confirmed by TXB 2 ELISA kit and Western blot analysis of PLC

Multi-pass spectroscopic ellipsometry

International Nuclear Information System (INIS)

Stehle, Jean-Louis; Samartzis, Peter C.; Stamataki, Katerina; Piel, Jean-Philippe; Katsoprinakis, George E.; Papadakis, Vassilis; Schimowski, Xavier; Rakitzis, T. Peter; Loppinet, Benoit

2014-01-01

Spectroscopic ellipsometry is an established technique, particularly useful for thickness measurements of thin films. It measures polarization rotation after a single reflection of a beam of light on the measured substrate at a given incidence angle. In this paper, we report the development of multi-pass spectroscopic ellipsometry where the light beam reflects multiple times on the sample. We have investigated both theoretically and experimentally the effect of sample reflectivity, number of reflections (passes), angles of incidence and detector dynamic range on ellipsometric observables tanΨ and cosΔ. The multiple pass approach provides increased sensitivity to small changes in Ψ and Δ, opening the way for single measurement determination of optical thickness T, refractive index n and absorption coefficient k of thin films, a significant improvement over the existing techniques. Based on our results, we discuss the strengths, the weaknesses and possible applications of this technique. - Highlights: • We present multi-pass spectroscopic ellipsometry (MPSE), a multi-pass approach to ellipsometry. • Different detectors, samples, angles of incidence and number of passes were tested. • N passes improve polarization ratio sensitivity to the power of N. • N reflections improve phase shift sensitivity by a factor of N. • MPSE can significantly improve thickness measurements in thin films

Performance of single-pass and by-pass multi-step multi-soil-layering systems for low-(C/N)-ratio polluted river water treatment.

Science.gov (United States)

Wei, Cai-Jie; Wu, Wei-Zhong

2018-09-01

Two kinds of hybrid two-step multi-soil-layering (MSL) systems loaded with different filter medias (zeolite-ceramsite MSL-1 and ceramsite-red clay MSL-2) were set-up for the low-(C/N)-ratio polluted river water treatment. A long-term pollutant removal performance of these two kinds of MSL systems was evaluated for 214 days. By-pass was employed in MSL systems to evaluate its effect on nitrogen removal enhancement. Zeolite-ceramsite single-pass MSL-1 system owns outstanding ammonia removal capability (24 g NH 4 + -Nm -2 d -1 ), 3 times higher than MSL-2 without zeolite under low aeration rate condition (0.8 × 10 4  L m -2 .h -1 ). Aeration rate up to 1.6 × 10 4  L m -2 .h -1 well satisfied the requirement of complete nitrification in first unit of both two MSLs. However, weak denitrification in second unit was commonly observed. By-pass of 50% influent into second unit can improve about 20% TN removal rate for both MSL-1 and MSL-2. Complete nitrification and denitrification was achieved in by-pass MSL systems after addition of carbon source with the resulting C/N ratio up to 2.5. The characters of biofilms distributed in different sections inside MSL-1 system well illustrated the nitrogen removal mechanism inside MSL systems. Two kinds of MSLs are both promising as an appealing nitrifying biofilm reactor. Recirculation can be considered further for by-pass MSL-2 system to ensure a complete ammonia removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Regional cerebral blood flow measurement with intravenous [15O]water bolus and [18F]fluoromethane inhalation

International Nuclear Information System (INIS)

Herholz, K.; Pietrzyk, U.; Wienhard, K.; Hebold, I.; Pawlik, G.; Wagner, R.; Holthoff, V.; Klinkhammer, P.; Heiss, W.D.

1989-01-01

In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both [ 15 O]water and [ 18 F]fluoromethane as tracers. Cerebral blood flow was also determined according to the autoradiographic technique with a bolus injection of [ 15 O]water. There were reasonable overall correlations between dynamic [ 15 O]water and [ 18 F]fluoromethane values for cerebral blood flow (r = 0.82) and between dynamic and autoradiographic [ 15 O]water values for cerebral blood flow (r = 0.83). We found a close correspondence between abnormal pathologic findings and visually evaluated cerebral blood flow tomograms obtained with the two tracers. On average, dynamic [ 15 O]water cerebral blood flow was 6% lower than that measured with [ 18 F]fluoromethane. There also was a general trend toward a greater underestimation with [ 15 O]water in high-flow areas, particularly in hyperemic areas, probably due to incomplete first-pass extraction of [ 15 O]water. Underestimation was not detected in low-flow areas or in the cerebellum. Absolute cerebral blood flow values were less closely correlated between tracers and techniques than cerebral blood flow patterns. The variability of the relation between absolute flow values was probably caused by confounding effects of the variation in the circulatory delay time. The autoradiographic technique was most sensitive to this type error

Detection of single-copy functional genes in prokaryotic cells by two-pass TSA-FISH with polynucleotide probes.

Science.gov (United States)

Kawakami, Shuji; Hasegawa, Takuya; Imachi, Hiroyuki; Yamaguchi, Takashi; Harada, Hideki; Ohashi, Akiyoshi; Kubota, Kengo

2012-02-01

In situ detection of functional genes with single-cell resolution is currently of interest to microbiologists. Here, we developed a two-pass tyramide signal amplification (TSA)-fluorescence in situ hybridization (FISH) protocol with PCR-derived polynucleotide probes for the detection of single-copy genes in prokaryotic cells. The mcrA gene and the apsA gene in methanogens and sulfate-reducing bacteria, respectively, were targeted. The protocol showed bright fluorescence with a good signal-to-noise ratio and achieved a high efficiency of detection (>98%). The discrimination threshold was approximately 82-89% sequence identity. Microorganisms possessing the mcrA or apsA gene in anaerobic sludge samples were successfully detected by two-pass TSA-FISH with polynucleotide probes. The developed protocol is useful for identifying single microbial cells based on functional gene sequences. Copyright © 2011 Elsevier B.V. All rights reserved.

Single-event multilevel surgery for children with cerebral palsy: a systematic review.

Science.gov (United States)

McGinley, Jennifer L; Dobson, Fiona; Ganeshalingam, Rekha; Shore, Benjamin J; Rutz, Erich; Graham, H Kerr

2012-02-01

To conduct a systematic review of single-event multilevel surgery (SEMLS) for children with cerebral palsy, with the aim of evaluating the quality of the evidence and developing recommendations for future research. The systematic review was conducted using standard search and extraction methods in Medline, EMBASE, CINAHL, and Cochrane electronic databases. For the purposes of this review, SEMLS was defined as two or more soft-tissue or bony surgical procedures at two or more anatomical levels during one operative procedure, requiring only one hospital admission and one period of rehabilitation. Studies were included if: (1) the primary focus was to examine the effect of SEMLS in children with cerebral palsy; (2) the results focused on multiple anatomic levels and reported findings of one or more World Health Organization International Classification of Functioning, Disability and Health (ICF) domains. Studies that focused on a single intervention or level, or on the utility of a specific outcome measure were excluded. Study quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) and the Oxford Centre for Evidence-Based Medicine scale. The review also examined the reporting of surgery, adverse events, and rehabilitation. Thirty-one studies fulfilled the criteria for inclusion, over the period 1985 to October 2010. The MINORS score for these studies varied from 4 to 19, with marked variation in the quality of reporting. Study quality has improved over recent years. Valid measures of gait and function have been introduced and several of the most recent studies have addressed multiple dimensions of the ICF. A statistical synthesis of the outcome data was not conducted, although a trend towards favourable outcomes in gait was evident. Caution is advised with interpretation owing to the variable study quality. Uncontrolled studies may have resulted in an overestimation of treatment efficacy. The design and reporting of studies of SEMLS are

Special applications of [sup 99m]Tc-HM-PAO SPECT in the evaluation of cerebral hemodynamics

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Shigeki; Kageyama, Yuhsuke (Chiba Emergency Medical Center (Japan)); Namba, Hiroki (and others)

1991-12-01

[sup 99m]Tc-HM-PAO has been widely used as a brain-perfusion tracer. It is known that this lipophilic tracer crosses the blood-brain barrier with a high-pass extraction fraction, is deposited in the brain proportional to the cerebral blood flow, and shows a nearly constant maintenance of the regional distribution over several hours. Taking advantage of these characteristics of the tracer, we evaluated changes in the cerebral blood flow before and after recanalization therapy in the acute stage of stroke. Recent advances in catheterization technique have made it possible to introduce a catheter superselectively into smaller cerebral vessels, such as anterior, middle, and posterior cerebral arteries and external carotid artery branches. We ourselves evaluated the areas and concentrations of anti-cancer agents by injecting HM-PAO through the microcatheter used for superselective intra-arterial chemotherapy. We also visualized the areas supplied by the grafted vessels after bypass surgery for ischemic cerebrovascular diseases by the superselective infusion of HM-PAO. We found these techniques to be useful in clinical neurosurgery. (author).

Single-cell resolution mapping of neuronal damage in acute focal cerebral ischemia using thallium autometallography.

Science.gov (United States)

Stöber, Franziska; Baldauf, Kathrin; Ziabreva, Iryna; Harhausen, Denise; Zille, Marietta; Neubert, Jenni; Reymann, Klaus G; Scheich, Henning; Dirnagl, Ulrich; Schröder, Ulrich H; Wunder, Andreas; Goldschmidt, Jürgen

2014-01-01

Neuronal damage shortly after onset or after brief episodes of cerebral ischemia has remained difficult to assess with clinical and preclinical imaging techniques as well as with microscopical methods. We here show, in rodent models of middle cerebral artery occlusion (MCAO), that neuronal damage in acute focal cerebral ischemia can be mapped with single-cell resolution using thallium autometallography (TlAMG), a histochemical technique for the detection of the K(+)-probe thallium (Tl(+)) in the brain. We intravenously injected rats and mice with thallium diethyldithiocarbamate (TlDDC), a lipophilic chelate complex that releases Tl(+) after crossing the blood-brain barrier. We found, within the territories of the affected arteries, areas of markedly reduced neuronal Tl(+) uptake in all animals at all time points studied ranging from 15 minutes to 24 hours after MCAO. In large lesions at early time points, areas with neuronal and astrocytic Tl(+) uptake below thresholds of detection were surrounded by putative penumbral zones with preserved but diminished Tl(+) uptake. At 24 hours, the areas of reduced Tl(+)uptake matched with areas delineated by established markers of neuronal damage. The results suggest the use of (201)TlDDC for preclinical and clinical single-photon emission computed tomography (SPECT) imaging of hyperacute alterations in brain K(+) metabolism and prediction of tissue viability in cerebral ischemia.

Extracting Models in Single Molecule Experiments

Science.gov (United States)

Presse, Steve

2013-03-01

Single molecule experiments can now monitor the journey of a protein from its assembly near a ribosome to its proteolytic demise. Ideally all single molecule data should be self-explanatory. However data originating from single molecule experiments is particularly challenging to interpret on account of fluctuations and noise at such small scales. Realistically, basic understanding comes from models carefully extracted from the noisy data. Statistical mechanics, and maximum entropy in particular, provide a powerful framework for accomplishing this task in a principled fashion. Here I will discuss our work in extracting conformational memory from single molecule force spectroscopy experiments on large biomolecules. One clear advantage of this method is that we let the data tend towards the correct model, we do not fit the data. I will show that the dynamical model of the single molecule dynamics which emerges from this analysis is often more textured and complex than could otherwise come from fitting the data to a pre-conceived model.

Comparative Study of Single- and Multi-Wall Carbon Nanotubes with Application in Cerebral Aneurysm

Directory of Open Access Journals (Sweden)

Rodica-Mariana Ion

2011-01-01

Full Text Available Helping improve humanity is one of the promises of nanotech-
nology and nanomedicine. This paper will highlight some of the research findings in the nanomedicine area by testing some single- and multi-walls carbon nanotubues in rats cerebral aneurisms.

Single DV-DXCCII Based Voltage Controlled First Order All-pass Filter with Inverting and Non-inverting responses

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B Chaturvedi

2015-12-01

Full Text Available In this paper, a new voltage controlled first order all-pass filter is presented. The proposed circuit employs a single differential voltage dual-X second generation current conveyor (DV-DXCCII and a grounded capacitor only. The proposed all-pass filter provides both inverting and non inverting voltage-mode outputs from the same configuration simultaneously without any matching condition. Non-ideal analysis along with sensitivity analysis is also investigated. The proposed circuit has low active and passive sensitivities. As an application the proposed all-pass filter is connected in cascade to get higher order filter. The theoretical results are validated thorough PSPICE simulations using TSMC 0.18µm CMOS process parameters.

Single Sustained Inflation followed by Ventilation Leads to Rapid Cardiorespiratory Recovery but Causes Cerebral Vascular Leakage in Asphyxiated Near-Term Lambs.

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Kristina S Sobotka

Full Text Available A sustained inflation (SI rapidly restores cardiac function in asphyxic, bradycardic newborns but its effects on cerebral haemodynamics and brain injury are unknown. We determined the effect of different SI strategies on carotid blood flow (CaBF and cerebral vascular integrity in asphyxiated near-term lambs.Lambs were instrumented and delivered at 139 ± 2 d gestation and asphyxia was induced by delaying ventilation onset. Lambs were randomised to receive 5 consecutive 3 s SI (multiple SI; n = 6, a single 30 s SI (single SI; n = 6 or conventional ventilation (no SI; n = 6. Ventilation continued for 30 min in all lambs while CaBF and respiratory function parameters were recorded. Brains were assessed for gross histopathology and vascular leakage.CaBF increased more rapidly and to a greater extent during a single SI (p = 0.01, which then decreased below both other groups by 10 min, due to a higher cerebral oxygen delivery (p = 0.01. Blood brain barrier disruption was increased in single SI lambs as indicated by increased numbers of blood vessel profiles with plasma protein extravasation (p = 0.001 in the cerebral cortex. There were no differences in CaBF or cerebral oxygen delivery between the multiple SI and no SI lambs.Ventilation with an initial single 30 s SI improves circulatory recovery, but is associated with greater disruption of blood brain barrier function, which may exacerbate brain injury suffered by asphyxiated newborns. This injury may occur as a direct result of the initial SI or to the higher tidal volumes delivered during subsequent ventilation.

Single-pass high-gain tapered free-electron laser with transverse diffraction in the postsaturation regime

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Cheng-Ying Tsai

2018-06-01

Full Text Available It has been well known that the resonant interaction of an ultrarelativistic electron beam and the radiation field in the single-pass high-gain free electron laser (FEL amplifier leads to the optical gain guiding. The transverse Laplacian term of the slowly varying wave equation in the linear regime can be approximated as a constant detuning parameter, i.e., |∇_{⊥}^{2}|∼k_{R}/z_{R} where k_{R} is the resonant wave number and z_{R} is the Rayleigh range of the laser. In the post-saturation regime, the radiation power begins to oscillate about an equilibrium for the untapered case while continues to grow by undulator tapering. Moreover, in this regime the gain guiding decreases and the simple constant detune is no longer valid. In this paper we study the single-pass high-gain FEL performance in the post-saturation regime with inclusion of diffraction effect and undulator tapering. Our analysis relies upon two constants of motion, one from the energy conservation and the other from the adiabatic invariant of the action variable. By constructing a two-dimensional axisymmetric wave equation and the coupled one-dimensional electron dynamical equations, the performance of a tapered FEL in the postsaturation regime can be analyzed, including the fundamental mode profile, the power efficiency and the scaled energy spread. We begin the analytical investigation with two different axisymmetric electron beam profiles, the uniform and bounded parabolic ones. It is found that the tapered FEL power efficiency can be smaller but close to the taper ratio provided the resonant phase remains constant and the beam-wave is properly matched. Such a tapered efficiency is nearly independent of transverse electron beam size before significant electron detrapping occurs. This is essentially different from the untapered case, where the power extraction efficiency is around the essential FEL gain bandwidth (or ρ, the Pierce or FEL parameter and depends on the beam

Forensic applications of cerebral single photon emission computed tomography in mild traumatic brain injury.

Science.gov (United States)

Wortzel, Hal S; Filley, Christopher M; Anderson, C Alan; Oster, Timothy; Arciniegas, David B

2008-01-01

Traumatic brain injury (TBI) is a substantial source of mortality and morbidity world wide. Although most such injuries are relatively mild, accurate diagnosis and prognostication after mild TBI are challenging. These problems are complicated further when considered in medicolegal contexts, particularly civil litigation. Cerebral single photon emission computed tomography (SPECT) may contribute to the evaluation and treatment of persons with mild TBI. Cerebral SPECT is relatively sensitive to the metabolic changes produced by TBI. However, such changes are not specific to this condition, and their presence on cerebral SPECT imaging does not confirm a diagnosis of mild TBI. Conversely, the absence of abnormalities on cerebral SPECT imaging does not exclude a diagnosis of mild TBI, although such findings may be of prognostic value. The literature does not demonstrate consistent relationships between SPECT images and neuropsychological testing or neuropsychiatric symptoms. Using the rules of evidence shaped by Daubert v. Merrell Dow Pharmaceuticals, Inc., and its progeny to analyze the suitability of SPECT for forensic purposes, we suggest that expert testimony regarding SPECT findings should be admissible only as evidence to support clinical history, neuropsychological test results, and structural brain imaging findings and not as stand-alone diagnostic data.

An experimental evaluation of multi-pass solar air heaters

Energy Technology Data Exchange (ETDEWEB)

Satcunanathan, S.; Persad, P.

1980-12-01

Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

The method for simultaneous extraction and back extraction in liquid three-phase system and equipment for simultaneous extraction and back extraction in liquid three-phase system

International Nuclear Information System (INIS)

Palyska, W.; Chmielewski, A.G.

1992-01-01

The method for simultaneous extraction and back extraction in liquid three-phase system has been worked out. The equipment designed for that process has been also subject of the patent. The interesting component is extracted first to intermediate phase consists of magnetic solvent keeping two extracting phases separately. The intermediate magnetic liquid has been kept in its position using a stable magnet maintained on the surface of the extraction vessel. Then the component pass from intermediate phase to the third phase as a result of back extraction. Mixing in the extraction and back extraction zones is organized by means of rotating shaft going along the whole apparatus. The extraction and back extraction processes occur simultaneously as a result of continuous flow of solvent in their zones. The single extraction back extraction facilities can be joined in larger batteries. 3 figs

Study on the improvement effect of edaravone combined with Ginkgo biloba extract on neurological function after interventional therapy of cerebral infarction

Directory of Open Access Journals (Sweden)

Xiang-Yang Hu1

2017-05-01

Full Text Available Objective: To study the effect of edaravone combined with Ginkgo biloba extract on neurological function after interventional therapy of cerebral infarction. Methods: A total of 152 cases of patients with acute cerebral infarction who received interventional therapy in Mianyang Central Hospital between May 2013 and September 2016 were retrospectively analyzed and divided into intervention group and control group, intervention group received routine treatment combined with edaravone and Ginkgo biloba extract treatment after interventional therapy, and control group received routine medical treatment after interventional therapy. 3 d, 7 d, 14 d after therapy, serum was separated, and the levels of neural function injury markers, oxidative stress products, antioxidant enzymes and platelet activation indexes were determined. Results: 3 d, 7 d and 14 d after treatment, serum UCH-L1, GFAP, NSE, S100B, ROS, GMP-140, PAC-1 and CD62p contents of intervention group were significantly lower than those of control group while CAT, SOD and GSH-PX contents were significantly higher than those of control group. Conclusion: Edaravone combined with Ginkgo biloba extract can reduce neurological injury and promote neurological function recovery after interventional therapy of cerebral infarction, and this effect is related to the reduction of oxidative stress and inhibition of platelet activation.

Milestone experiments for single pass UV/X-ray FELs

Science.gov (United States)

Ben-Zvi, Ilan

1995-04-01

In the past decade, significant advances have been made in the theory and technology of high brightness electron beams and single pass FELs. These developments facilitate the construction of practical UV and X-ray FELs and has prompted proposals to the DOE for the construction of such facilities. There are several important experiments to be performed before committing to the construction of dedicated user facilities. Two experiments are under construction in the IR, the UCLA self-amplified spontaneous emission experiment and the BNL laser seeded harmonic generation experiment. A multi-institution collaboration is being organized about a 210 MeV electron linac available at BNL and the 10 m long NISUS wiggler. This experiment will be done in the UV and will test various experimental aspects of electron beam dynamics, FEL exponential regime with gain guiding, start-up from noise, seeding and harmonic generation. These experiments will advance the state of FEL research and lead towards future dedicated users' facilities.

Milestone experiments for single pass UV/X-ray FELs

International Nuclear Information System (INIS)

Ben-Zvi, I.

1994-01-01

In the past decade, significant advances have been made in the theory and technology of high brightness electron beams and single pass FELS. These developments facilitate the construction of practical UV and X-ray FELs and has prompted proposals to the DOE for the construction of such facilities. There are several important experiments to be performed before committing to the construction of dedicated user facilities. Two experiments are under construction in the IR, the UCLA Self Amplified Spontaneous Emission experiment and the BNL laser seeded Harmonic Generation experiment. A multi-institution collaboration is being organized about a 210 MeV electron linac available at BNL and the 10 meter tong NISUS wiggler. This experiment will be done in the UV and will test various experimental aspects of electron beam dynamics, FEL exponential regime with gain guiding, start up from noise, seeding and harmonic generation. These experiments will advance the state of FEL research and lead towards future dedicated users' facilities

Perawatan Gigi dengan Anestesi Umum pada Anak Cerebral Palsy (Laporan Kasus

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Tri Putriany A. M. Putriany

2015-11-01

Full Text Available This report describes an 11 years old boy with Cerebral Palsy who treated under general anesthesia, because patient extremely uncooperative. Treatment involved 2 GIC restorations and 7 extractions. Under general anesthesia, total oral rehabilitation can be finished at a single operative visit with minimal psychological trauma. At follow-ip visit patient exhibited positive behavior and better coping with dental situation.

Single-Pass Percutaneous Liver Biopsy for Diffuse Liver Disease Using an Automated Device: Experience in 154 Procedures

International Nuclear Information System (INIS)

Rivera-Sanfeliz, Gerant; Kinney, Thomas B.; Rose, Steven C.; Agha, Ayad K.M.; Valji, Karim; Miller, Franklin J.; Roberts, Anne C.

2005-01-01

Purpose: To describe our experience with ultrasound (US)-guided percutaneous liver biopsies using the INRAD 18G Express core needle biopsy system.Methods: One hundred and fifty-four consecutive percutaneous core liver biopsy procedures were performed in 153 men in a single institution over 37 months. The medical charts, pathology reports, and radiology files were retrospectively reviewed. The number of needle passes, type of guidance, change in hematocrit level, and adequacy of specimens for histologic analysis were evaluated.Results: All biopsies were performed for histologic staging of chronic liver diseases. The majority of patients had hepatitis C (134/153, 90.2%). All patients were discharged to home after 4 hr of postprocedural observation. In 145 of 154 (94%) biopsies, a single needle pass was sufficient for diagnosis. US guidance was utilized in all but one of the procedures (153/154, 99.4%). The mean hematocrit decrease was 1.2% (44.1-42.9%). Pain requiring narcotic analgesia, the most frequent complication, occurred in 28 of 154 procedures (18.2%). No major complications occurred. The specimens were diagnostic in 152 of 154 procedures (98.7%).Conclusions: Single-pass percutaneous US-guided liver biopsy with the INRAD 18G Express core needle biopsy system is safe and provides definitive pathologic diagnosis of chronic liver disease. It can be performed on an outpatient basis. Routine post-biopsy monitoring of hematocrit level in stable, asymptomatic patients is probably not warranted

Panax ginseng extract attenuates neuronal injury and cognitive deficits in rats with vascular dementia induced by chronic cerebral hypoperfusion

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Jun-De Zhu

2018-01-01

Full Text Available Panax ginseng is a slow-growing perennial plant. Panax ginseng extract has numerous biological activities, including antitumor, anti-inflammatory and antistress activities. Panax ginseng extract also has a cognition-enhancing effect in rats with alcohol-induced memory impairment. In this study, we partially occluded the bilateral carotid arteries in the rat to induce chronic cerebral hypoperfusion, a well-known model of vascular dementia. The rats were then intragastrically administered 50 or 100 mg/kg Panax ginseng extract. Morris water maze and balance beam tests were used to evaluate memory deficits and motor function, respectively. Protein quantity was used to evaluate cholinergic neurons. Immunofluorescence staining was used to assess the number of glial fibrillary acidic protein-positive cells. Western blot assay was used to evaluate protein levels of vascular endothelial growth factor, basic fibroblast growth factor, Bcl-2 and Bax. Treatment with Panax ginseng extract for 8 weeks significantly improved behavioral function and increased neuronal density and VEGF and bFGF protein expression in the hippocampal CA3 area. Furthermore, Panax ginseng extract reduced the number of glial fibrillary acidic protein-immunoreactive cells, and it decreased apoptosis by upregulating Bcl-2 and downregulating Bax protein expression. The effect of Panax ginseng extract was dose-dependent and similar to that of nimodipine, a commonly used drug for the treatment of vascular dementia. These findings suggest that Panax ginseng extract is neuroprotective against vascular dementia induced by chronic cerebral hypoperfusion, and therefore might have therapeutic potential for preventing and treating the disease.

Single-Rooted Extraction Sockets: Classification and Treatment Protocol.

Science.gov (United States)

El Chaar, Edgar; Oshman, Sarah; Fallah Abed, Pooria

2016-09-01

Clinicians have many treatment techniques from which to choose when extracting a failing tooth and replacing it with an implant-supported restoration and when successful management of an extraction socket during the course of tooth replacement is necessary to achieve predictable and esthetic outcomes. This article presents a straightforward, yet thorough, classification for extraction sockets of single-rooted teeth and provides guidance to clinicians in the selection of appropriate and predictable treatment. The presented classification of extraction sockets for single-rooted teeth focuses on the topography of the extraction socket, while the protocol for treatment of each socket type factors in the shape of the remaining bone, the biotype, and the location of the socket whether it be in the mandible or maxilla. This system is based on the biologic foundations of wound healing and can help guide clinicians to successful treatment outcomes.

The baboon model under anaesthesia for in vivo cerebral blood flow studies using single photon emission computed tomographic (SPECT) techniques

International Nuclear Information System (INIS)

Dormehl, I.; Redelinghuys, F.; Hugo, N.; Oliver, D.; Pilloy, W.

1992-01-01

Single photon computed tomography of the brain can be useful in animal experimentation directed towards cerebral conditions. A well established and understood baboon model, necessarily under anaesthesia, could especially be valuable in such investigations. Six normal baboons were studied under various anesthetic agents and their combinations: ketamine, thiopentone, pentobarbitone and halothane. Cerebral blood flow (CBF) studies were performed with 99m Tc-HMPAO. CBF effects from various anaesthesia were detected, requiring careful choice of the anaesthesia for cerebral investigations. (author). 13 refs, 4 figs, 3 tabs

The baboon model under anaesthesia for in vivo cerebral blood flow studies using single photon emission computed tomographic (SPECT) techniques

Energy Technology Data Exchange (ETDEWEB)

Dormehl, I.; Redelinghuys, F.; Hugo, N. [Pretoria Univ. (South Africa); Oliver, D.; Pilloy, W. [Medical Univ. of Southern Africa (MEDUNSA), Pretoria (South Africa)

1992-12-31

Single photon computed tomography of the brain can be useful in animal experimentation directed towards cerebral conditions. A well established and understood baboon model, necessarily under anaesthesia, could especially be valuable in such investigations. Six normal baboons were studied under various anesthetic agents and their combinations: ketamine, thiopentone, pentobarbitone and halothane. Cerebral blood flow (CBF) studies were performed with {sup 99m}Tc-HMPAO. CBF effects from various anaesthesia were detected, requiring careful choice of the anaesthesia for cerebral investigations. (author). 13 refs, 4 figs, 3 tabs.

Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

Energy Technology Data Exchange (ETDEWEB)

Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

2004-05-01

Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

Atrial electrogram quality in single-pass defibrillator leads with floating atrial bipole in patients with permanent atrial fibrillation and cardiac resynchronization therapy.

Science.gov (United States)

Sticherling, Christian; Müller, Dirk; Schaer, Beat A; Krüger, Silke; Kolb, Christof

2018-03-27

Many patients receiving cardiac resynchronization therapy (CRT) suffer from permanent atrial fibrillation (AF). Knowledge of the atrial rhythm is important to direct pharmacological or interventional treatment as well as maintaining AV-synchronous biventricular pacing if sinus rhythm can be restored. A single pass single-coil defibrillator lead with a floating atrial bipole has been shown to obtain reliable information about the atrial rhythm but has never been employed in a CRT-system. The purpose of this study was to assess the feasibility of implanting a single coil right ventricular ICD lead with a floating atrial bipole and the signal quality of atrial electrograms (AEGM) in CRT-defibrillator recipients with permanent AF. Seventeen patients (16 males, mean age 73 ± 6 years, mean EF 25 ± 5%) with permanent AF and an indication for CRT-defibrillator placement were implanted with a designated CRT-D system comprising a single pass defibrillator lead with a atrial floating bipole. They were followed-up for 103 ± 22 days using remote monitoring for AEGM transmission. All patients had at last one AEGM suitable for atrial rhythm diagnosis and of 100 AEGM 99% were suitable for visual atrial rhythm assessment. Four patients were discharged in sinus rhythm and one reverted to AF during follow-up. Atrial electrograms retrieved from a single-pass defibrillator lead with a floating atrial bipole can be reliably used for atrial rhythm diagnosis in CRT recipients with permanent AF. Hence, a single pass ventricular defibrillator lead with a floating bipole can be considered in this population. Copyright © 2018 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

Comparative Analysis of Single and Dual Irradiation Pass of Deep Burn High Temperature Reactor Scenario

International Nuclear Information System (INIS)

Jeong, Chang Joon; Jo, Chang Keun; Noh, Jae Man

2012-01-01

A concept of a deep-burn (DB) of trans uranic (TRU) elements in a high temperature reactor (HTR) has been proposed and studied with a single irradiation pass. However, there is still a significant amount of TRU after burn in an HTR. Therefore, it is necessary to burn more TRU in a fast reactor (FR) with repeated reprocessing such as a pyro-process. In this study, the fuel cycle calculations are performed and the results are compared for a singlepass DB-HHR scenario and a dual-pass sodium-cooled fast reactor (SFR) scenario. For the analysis, front-end and back-end parameters are compared. The calculations were performed by the DANESS (Dynamic Analysis of Nuclear Energy System Strategies), which is an integrated system dynamic fuel cycle analysis code

Double Pass 595 nm Pulsed Dye Laser Does Not Enhance the Efficacy of Port Wine Stains Compared with Single Pass: A Randomized Comparison with Histological Examination.

Science.gov (United States)

Yu, Wenxin; Zhu, Jiafang; Wang, Lizhen; Qiu, Yajing; Chen, Yijie; Yang, Xi; Chang, Lei; Ma, Gang; Lin, Xiaoxi

2018-03-27

To compare the efficacy and safety of double-pass pulsed dye laser (DWL) and single-pass PDL (SWL) in treating virgin port wine stain (PWS). The increase in the extent of vascular damage attributed to the use of double-pass techniques for PWS remains inconclusive. A prospective, side-by-side comparison with a histological study for virgin PWS is still lacking. Twenty-one patients (11 flat PWS, 10 hypertrophic PWS) with untreated PWS underwent 3 treatments at 2-month intervals. Each PWS was divided into three treatment sites: SWL, DWL, and untreated control. Chromametric and visual evaluation of the efficacy and evaluation of side effects were conducted 3 months after final treatment. Biopsies were taken at the treated sites immediately posttreatment. Chromametric and visual evaluation suggested that DWL sites showed no significant improvement compared with SWL (p > 0.05) in treating PWS. The mean depth of photothermal damage to the vessels was limited to a maximum of 0.36-0.41 mm in both SWL and DWL sides. Permanent side effects were not observed in any patients. Double-pass PDL does not enhance PWS clearance. To improve the clearance of PWS lesions, either the depth of laser penetration should be increased or greater photothermal damage to vessels should be generated.

Effect of burn and first-pass splanchnic leucine extraction on protein kinetics in rats

International Nuclear Information System (INIS)

Karlstad, M.D.; DeMichele, S.J.; Istfan, N.; Blackburn, G.L.; Bistrian, B.R.

1988-01-01

The effects of burn and first-pass splanchnic leucine extraction (FPE) on protein kinetics and energy expenditure were assessed by measuring O 2 consumption, CO 2 production, nitrogen balance, leucine kinetics, and tissue fractional protein synthetic rates (FSR-%/day) in enterally fed rats. Anesthetized male rats (200 g) were scalded on their dorsum with boiling water (25-30% body surface area) and enterally fed isovolemic diets that provided 60 kcal/day and 2.4 g of amino acids/day for 3 days. Controls were not burned. An intravenous or intragastric infusion of L-[1- 14 C]leucine was used to assess protein kinetics on day 3. FPE was taken as the ratio of intragastric to intravenous plasma leucine specific activity. There was a 69% reduction in cumulative nitrogen balance (P less than 0.001) and a 17-19% increase in leucine oxidation (P less than 0.05) and total energy expenditure (P less than 0.01) in burned rats. A 15% decrease in plasma leucine clearance (P less than 0.05) was accompanied by a 20% increase in plasma [leucine] (P less than 0.01) in burned rats. Burn decreased rectus muscle FSR from 5.0 +/- 0.4 to 3.5 +/- 0.5 (P less than 0.05) and increased liver FSR from 19.0 +/- 0.5 to 39.2 +/- 3.4 (P less than 0.01). First pass extraction of dietary leucine by the splanchnic bed was 8% in controls and 26% in burned rats. Leucine kinetics corrected for FPE showed increased protein degradation with burn that was not evident without FPE correction. This hypermetabolic burn model can be useful in the design of enteral diets that optimize rates of protein synthesis and degradation

Single-Fraction Proton Beam Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations

Energy Technology Data Exchange (ETDEWEB)

Hattangadi-Gluth, Jona A. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Chapman, Paul H. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Kim, Daniel; Niemierko, Andrzej; Bussière, Marc R.; Stringham, Alison; Daartz, Juliane [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Ogilvy, Christopher [Department of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts (United States); Loeffler, Jay S. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

2014-06-01

Purpose/Objective(s): To evaluate the obliteration rate and potential adverse effects of single-fraction proton beam stereotactic radiosurgery (PSRS) in patients with cerebral arteriovenous malformations (AVMs). Methods and Materials: From 1991 to 2010, 248 consecutive patients with 254 cerebral AVMs received single-fraction PSRS at our institution. The median AVM nidus volume was 3.5 cc (range, 0.1-28.1 cc), 23% of AVMs were in critical/deep locations (basal ganglia, thalamus, or brainstem), and the most common prescription dose was 15 Gy(relative biological effectiveness [RBE]). Univariable and multivariable analyses were performed to assess factors associated with obliteration and hemorrhage. Results: At a median follow-up time of 35 months (range, 6-198 months), 64.6% of AVMs were obliterated. The median time to total obliteration was 31 months (range, 6-127 months), and the 5-year and 10-year cumulative incidence of total obliteration was 70% and 91%, respectively. On univariable analysis, smaller target volume (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.86-0.93, P<.0001), smaller treatment volume (HR 0.93, 95% CI 0.90-0.96, P<.0001), higher prescription dose (HR 1.16, 95% CI 1.07-1.26, P=.001), and higher maximum dose (HR 1.14, 95% CI 1.05-1.23, P=.002) were associated with total obliteration. Deep/critical location was also associated with decreased likelihood of obliteration (HR 0.68, 95% CI 0.47-0.98, P=.04). On multivariable analysis, critical location (adjusted HR [AHR] 0.42, 95% CI 0.27-0.65, P<.001) and smaller target volume (AHR 0.81, 95% CI 0.68-0.97, P=.02) remained associated with total obliteration. Posttreatment hemorrhage occurred in 13 cases (5-year cumulative incidence of 7%), all among patients with less than total obliteration, and 3 of these events were fatal. The most common complication was seizure, controlled with medications, both acutely (8%) and in the long term (9.1%). Conclusions: The current series is the largest

Photoacoustic Soot Spectrometer (PASS) Instrument Handbook

Energy Technology Data Exchange (ETDEWEB)

Dubey, M [Los Alamos National Laboratory; Springston, S [Brookhaven National Laboratory; Koontz, A [Pacific Northwest National Laboratory; Aiken, A [Los Alamos National Laboratory

2013-01-17

The photoacoustic soot spectrometer (PASS) measures light absorption by aerosol particles. As the particles pass through a laser beam, the absorbed energy heats the particles and in turn the surrounding air, which sets off a pressure wave that can be detected by a microphone. The PASS instruments deployed by ARM can also simultaneously measure the scattered laser light at three wavelengths and therefore provide a direct measure of the single-scattering albedo. The Operator Manual for the PASS-3100 is included here with the permission of Droplet Measurement Technologies, the instrument’s manufacturer.

Interictal "patchy" regional cerebral blood flow patterns in migraine patients. A single photon emission computerized tomographic study

DEFF Research Database (Denmark)

Friberg, L; Olesen, J; Iversen, Helle Klingenberg

1994-01-01

In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right-left asymme......In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right...... rCBF images is insufficient to pick up abnormalities; (2) almost 50% of the migraine sufferers had abnormal rCBF/asymmetries. However, these are discrete compared with those typically seen during the aura phase of a migraine attack. One explanation to the patchy rCBF patterns might...

Static thermo-optic instability in double-pass fiber amplifiers

DEFF Research Database (Denmark)

Lægsgaard, Jesper

2016-01-01

A coupled-mode formalism, earlier used to describe transverse mode instabilities in single-pass optical fiber amplifiers, is extended to the case of double-pass amplifiers. Contrary to the single-pass case, it is shown that the thermo-optic nonlinearity can couple light at the same frequency...... between the LP01 and LP11 modes, leading to a static deformation of the output beam profile. This novel phenomenon is caused by the interaction of light propagating in either direction with thermo-optic index perturbations caused by light propagating in the opposite direction. The threshold power...... for the static deformation is found to be several times lower than what is typically found for the dynamic modal instabilities observed in single-pass amplifiers. (C) 2016 Optical Society of America...

Optical performance of multifocal soft contact lenses via a single-pass method.

Science.gov (United States)

Bakaraju, Ravi C; Ehrmann, Klaus; Falk, Darrin; Ho, Arthur; Papas, Eric

2012-08-01

A physical model eye capable of carrying soft contact lenses (CLs) was used as a platform to evaluate optical performance of several commercial multifocals (MFCLs) with high- and low-add powers and a single-vision control. Optical performance was evaluated at three pupil sizes, six target vergences, and five CL-correcting positions using a spatially filtered monochromatic (632.8 nm) light source. The various target vergences were achieved by using negative trial lenses. A photosensor in the retinal plane recorded the image point-spread that enabled the computation of visual Strehl ratios. The centration of CLs was monitored by an additional integrated en face camera. Hydration of the correcting lens was maintained using a humidity chamber and repeated instillations of rewetting saline drops. All the MFCLs reduced performance for distance but considerably improved performance along the range of distance to near target vergences, relative to the single-vision CL. Performance was dependent on add power, design, pupil, and centration of the correcting CLs. Proclear (D) design produced good performance for intermediate vision, whereas Proclear (N) design performed well at near vision (p 4 mm in diameter. Acuvue Oasys bifocal produced performance comparable with single-vision CL for most vergences. Direct measurement of single-pass images at the retinal plane of a physical model eye used in conjunction with various MFCLs is demonstrated. This method may have utility in evaluating the relative effectiveness of commercial and prototype designs.

A new solid-phase extraction disk based on a sheet of single-walled carbon nanotubes.

Science.gov (United States)

Niu, Hong Yun; Cai, Ya Qi; Shi, Ya Li; Wei, Fu Sheng; Liu, Jie Min; Jiang, Gui Bin

2008-11-01

A new kind of solid-phase extraction disk based on a sheet of single-walled carbon nanotubes (SWCNTs) is developed in this study. The properties of such disks are tested, and different disks showed satisfactory reproducibility. One liter of aqueous solution can pass through the disk within 10-100 min while still allowing good recoveries. Two disks (DD-disk) can be stacked to enrich phthalate esters, bisphenol A (BPA), 4-n-nonylphenol (4-NP), 4-tert-octylphenol (4-OP) and chlorophenols from various volumes of solution. The results show that SWCNT disks have high extraction ability for all analytes. The SWCNT disk can extract polar chlorophenols more efficiently than a C(18) disk from water solution. Unlike the activated carbon disk, analytes adsorbed by the new disks can be eluted completely with 8-15 mL of methanol or acetonitrile. Finally, the DD-disk system is used to pretreat 1000-mL real-world water samples spiked with BPA, 4-OP and 4-NP. Detection limits of 7, 25, and 38 ng L(-1) for BPA, 4-OP, and 4-NP, respectively, were achieved under optimized conditions. The advantages of this new disk include its strong adsorption ability, its high flow rate and its easy preparation.

Generation of coherent soft x-rays using a single-pass free-electron laser amplifier

International Nuclear Information System (INIS)

Wang, T.F.; Goldstein, J.C.; Newnam, B.E.; McVey, B.D.

1988-01-01

We consider a single-pass free-electron laser (FEL) amplifier, driven by an rf-linac followed by a damping ring for reduced emittance, for use in generating coherent light in the soft x-ray region. The dependence of the optical gain on electron-beam quality, studied with the three-dimensional FEL simulation code FELEX, is given and related to the expected power of self-amplified spontaneous emission. We discuss issues for the damping ring designed to achieve the required electron beam quality. The idea of a multipass regenerative amplifier is also presented

Single-photon tomographic determination of regional cerebral blood flow in epilepsy

International Nuclear Information System (INIS)

Bonte, F.J.; Devous, M.D. Sr.; Stokely, E.M.; Homan, R.W.

1983-01-01

Using a single-photon emission computed tomographic scanner (SPECT) the authors determined regional cerebral blood flow (rCBF) with inhaled xenon-133, a noninvasive procedure. Studies were performed in 40 normal individuals, and these were compared with rCBF determinations in 51 patients with seizure disorders. Although positive results were obtained in 15 of 16 patients with mass lesions, the group of principal interest comprised 25 patients suffering from ''temporal lobe'' epilepsy. Only one of these had a positive x-ray computed tomogram, but 16 had positive findings on rCBF study. These findings included increased local blood flow in the ictal state and reduced flow interictally

Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

Science.gov (United States)

Yamauchi, H; Fukuyama, H; Nagahama, Y; Katsumi, Y; Okazawa, H

1998-01-01

This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

Studies on water turbine runner which fish can pass through: In case of single stage axial runner

International Nuclear Information System (INIS)

Shimizu, Yukimari; Maeda, Takao; Nagoshi, Osamu; Ieda, Kazuma; Shinma, Hisako; Hagimoto, Michiko

1994-01-01

The relationship between water turbine runner design and operation and the safe passage of fish through the turbine is studied. The kinds of fish used in the tests are a dace, a sweet fish and a small salmon. A single stage axial runner is used. The velocity and pressure distributions were measured inside the turbine casing and along the casing wall. Many pictures showing fish passing through the rotating runner were taken and analyzed. The swimming speed of the fish was examined from video recordings. Fish pass through the runner more rapidly when they can determine and choose the easier path. Injury and mortality of fish are affected by the runner speed and the location of impact of the runner on the fish body

Accidents and transients analyses of a super fast reactor with single flow pass core

International Nuclear Information System (INIS)

Sutanto,; Oka, Yoshiaki

2014-01-01

Highlights: • Safety analysis of a Super FR with single flow pass core is conducted. • Loss of feed water flow leads to a direct effect on the loss of fuel channel flow. • The core pressure is sensitive to LOCA accidents due to the direct effect. • Small LOCA introduces a critical break. • The safety criteria for all selected events are satisfied. - Abstract: The supercritical water cooled fast reactor with single flow pass core has been designed to simplify refueling and the structures of upper and lower mixing plenums. To evaluate the safety performance, safety analysis has been conducted with regard to LOCA and non-LOCA accidents including transient events. Safety analysis results show that the safety criteria are satisfied for all selected events. The total loss of feed water flow is the most important accident which the maximum cladding surface temperature (MCST) is high due to a direct effect of the accident on the total loss of flow in all fuel assemblies. However, actuation of the ADS can mitigate the accident. Small LOCA also introduces a critical break at 7.8% break which results high MCST at BOC because the scram and ADS are not actuated. Early ADS actuation is effective to mitigate the accident. In large LOCA, 100% break LOCA results a high MCST of flooding phase at BOC due to high power peaking at the bottom part. Use of high injection flow rate by 2 LPCI units is effective to decrease the MCST

High-Accuracy Elevation Data at Large Scales from Airborne Single-Pass SAR Interferometry

Directory of Open Access Journals (Sweden)

Guy Jean-Pierre Schumann

2016-01-01

Full Text Available Digital elevation models (DEMs are essential data sets for disaster risk management and humanitarian relief services as well as many environmental process models. At present, on the hand, globally available DEMs only meet the basic requirements and for many services and modeling studies are not of high enough spatial resolution and lack accuracy in the vertical. On the other hand, LiDAR-DEMs are of very high spatial resolution and great vertical accuracy but acquisition operations can be very costly for spatial scales larger than a couple of hundred square km and also have severe limitations in wetland areas and under cloudy and rainy conditions. The ideal situation would thus be to have a DEM technology that allows larger spatial coverage than LiDAR but without compromising resolution and vertical accuracy and still performing under some adverse weather conditions and at a reasonable cost. In this paper, we present a novel single pass In-SAR technology for airborne vehicles that is cost-effective and can generate DEMs with a vertical error of around 0.3 m for an average spatial resolution of 3 m. To demonstrate this capability, we compare a sample single-pass In-SAR Ka-band DEM of the California Central Valley from the NASA/JPL airborne GLISTIN-A to a high-resolution LiDAR DEM. We also perform a simple sensitivity analysis to floodplain inundation. Based on the findings of our analysis, we argue that this type of technology can and should be used to replace large regions of globally available lower resolution DEMs, particularly in coastal, delta and floodplain areas where a high number of assets, habitats and lives are at risk from natural disasters. We conclude with a discussion on requirements, advantages and caveats in terms of instrument and data processing.

A Novel Single Pass Authenticated Encryption Stream Cipher for Software Defined Radios

DEFF Research Database (Denmark)

Khajuria, Samant

2012-01-01

to propose cryptographic services such as confidentiality, integrity and authentication. Therefore, integration of security services into SDR devices is essential. Authenticated Encryption schemes donate the class of cryptographic algorithms that are designed for protecting both message confidentiality....... This makes authenticated encryption very attractive for low-cost low-power hardware implementations, as it allows for the substantial decrease in the circuit area and power consumed compared to the traditional schemes. In this thesis, an authenticated encryption scheme is proposed with the focus of achieving...... high throughput and low overhead for SDRs. The thesis is divided into two research topics. One topic is the design of a 1-pass authenticated encryption scheme that can accomplish both message secrecy and authenticity in a single cryptographic primitive. The other topic is the implementation...

Measurement of cerebral blood flow by single photon emission tomography: principles and application to functional studies of the language areas

International Nuclear Information System (INIS)

Tran Dinh, Y.R.; Seylaz, J.

1989-01-01

Quantitative measurement of cerebral blood flow by single photon emission computerized tomography (SPECT) is a new technique which is particularly suitable for routine studies of cerebro-vascular diseases. SPECT can be used to examine the deep structures of the brain and cerebellum. The functional areas of the brain, which have hitherto been only accessible by clinical-anatomical methods, can be imaged by this technique, based on the correlation between cerebral blood flow and metabolism. The demonstration of preferential activation of temporal and frontal zones in the left hemisphere by active speech stimulation confirms the general principles of hemispheric lateralization of cerebral functions. In addition to this role in studying the physiology of normal subjects, the technique has practical pathological applications. Knowledge of hemispheric lateralization of spoken language should be a pre-operative test for cerebral lesion when there is a risk that surgical intervention may produce irreversible neuropsychological lesions [fr

Cerebral peritumoral oedema study: Does a single dynamic MR sequence assessing perfusion and permeability can help to differentiate glioblastoma from metastasis?

International Nuclear Information System (INIS)

Lehmann, Pierre; Saliou, Guillaume; Marco, Giovanni de; Monet, Pauline; Souraya, Stoquart-Elsankari; Bruniau, Alexis; Vallée, Jean Noel; Ducreux, Denis

2012-01-01

Our purpose was to differentiate glioblastoma from metastasis using a single dynamic MR sequence to assess perfusion and permeability parameters. 24 patients with glioblastoma or cerebral metastasis with peritumoral oedema were recruited and explored with a 3 T MR unit. Post processing used DPTools software. Regions of interest were drawn around contrast enhancement to assess relative cerebral blood volume and permeability parameters. Around the contrast enhancement Glioblastoma present high rCBV with modification of the permeability, metastasis present slight modified rCBV without modification of permeability. In conclusion, peritumoral T2 hypersignal exploration associating morphological MR and functional MR parameters can help to differentiate cerebral metastasis from glioblastoma.

Effects of multi-pass arc welding on mechanical properties of carbon steel C25 plate

International Nuclear Information System (INIS)

Adedayo, S.M.; Babatunde, A.S.

2013-01-01

The effects of multi-pass welding on mechanical properties of C25 carbon steel plate were examined. Mild steel plate workpieces of 90 x 55 mm 2 area and 10 mm thickness with a 30 degrees vee weld-grooves were subjected to single and multi-pass welding. Toughness, hardness and tensile tests of single and multi-pass welds were conducted. Toughness values of the welds under double pass welds were higher than both single pass and unwelded alloy, at respective maximum values of 2464, 2342 and 2170 kN/m. Hardness values were reduced under double pass relative to single pass welding with both being lower than the value for unwelded alloy; the values were 40.5, 43.2 and 48.5 Rs respectively at 12 mm from the weld line. The tensile strength of 347 N/mm 2 under multi-pass weld was higher than single pass weld with value of 314 N/mm 2 . Therefore, the temperature distribution and apparent pre-heating during multi-pass welding increased the toughness and tensile strength of the weldments, but reduced the hardness. (au)

Cerebral blood flow single-photon emission tomography with 123I-IMP in vascular dementia

International Nuclear Information System (INIS)

Kawahata, Nobuya; Gotoh, Chiharu; Yokoyama, Sakura; Daitoh, Nobuyuki

2001-01-01

Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P- 123 I-iodoamphetamine ( 123 I-IMP) and SPECT imager. The mCBF in VD was 27.6±5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6±6.1 ml/100 g/min and 32.5±5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

Quantification of modulated blood oxygenation levels in single cerebral veins by investigating their MR signal decay

Energy Technology Data Exchange (ETDEWEB)

Sedlacik, Jan [St. Jude Children' s Research Hospital, Memphis, TN (United States). Div. of Translational Imaging Research; University Clinics Jena (Germany). Medical Physics Group; Rauscher, Alexander [University Clinics Jena (Germany). Medical Physics Group; British Columbia Univ., Vancouver (Canada). MRI Research Centre; Reichenbach, Juergen R. [University Clinics Jena (Germany). Medical Physics Group

2009-07-01

The transverse magnetization of a single vein and its surrounding tissue is subject to spin dephasing caused by the local magnetic field inhomogeneity which is induced by the very same vessel. This phenomenon can be approximated and simulated by applying the model of an infinitely long and homogeneously magnetized cylinder embedded in a homogeneous tissue background. It is then possible to estimate the oxygenation level of the venous blood by fitting the simulated magnetization-time-course to the measured signal decay. In this work we demonstrate the ability of this approach to quantify the blood oxygenation level (Y) of small cerebral veins in vivo, not only under normal physiologic conditions (Y{sub native}=0.5-0.55) but also during induced changes of physiologic conditions which affect the cerebral venous blood oxygenation level. Changes of blood's oxygenation level induced by carbogen (5% CO{sub 2}, 95% O{sub 2}) and caffeine were observed and quantified, resulting in values of Y{sub carbogen}=0.7 and Y{sub caffeine}=0.42, respectively. The proposed technique may ultimately help to better understand local changes in cerebral physiology during neuronal activation by quantifying blood oxygenation in veins draining active brain areas. It may also be beneficial in clinical applications where it may improve diagnosis of cerebral pathologies as well as monitoring of responses to therapy. (orig.)

Hexane extracts of Polygonum multiflorum improve tissue and functional outcome following focal cerebral ischemia in mice.

Science.gov (United States)

Lee, Soo Vin; Choi, Kyung Ha; Choi, Young Whan; Hong, Jin Woo; Baek, Jin Ung; Choi, Byung Tae; Shin, Hwa Kyoung

2014-04-01

Polygonum multiflorum is a traditional Korean medicine that has been utilized widely in East Asian countries as a longevity agent. Clinical studies have demonstrated that Polygonum multiflorum improves hypercholesterolemia, coronary heart disease, neurosis and other diseases commonly associated with aging. However, scientific evidence defining the protective effects and mechanisms of Polygonum multiflorum against ischemic stroke is incomplete. In the present study, we investigated the cerebrovascular protective effects of Polygonum multiflorum against ischemic brain injury using an in vivo photothrombotic mouse model. To examine the underlying mechanism of action, we utilized an in vitro human brain microvascular endothelial cell (HBMEC) culture system. Hexane extracts (HEPM), ethyl acetate extracts (EAEPM) and methanol extracts (MEPM) of Polygonum multiflorum (100 mg/kg) were administered intraperitoneally 30 min prior to ischemic insult. Focal cerebral ischemia was induced in C57BL/6J mice and endothelial nitric oxide synthase knockout (eNOS KO) mice by photothrombotic cortical occlusion. We evaluated the infarct volume, as well as neurological and motor function, 24 h after ischemic brain injury. Following ischemic insult, HEPM induced a significant reduction in infarct volume and subsequent neurological deficits, compared with EAEPM and MEPM. HEPM significantly decreased infarct size and improved neurological and motor function, which was not observed in eNOS KO mice, suggesting that this cerebroprotective effect is primarily an eNOS-dependent mechanism. In vitro, HEPM effectively promoted NO production, however these effects were inhibited by the NOS inhibitor, L-NAME and the PI3K/Akt inhibitor, LY-294002. Furthermore, HEPM treatment resulted in increased phosphorylation-dependent activation of Akt and eNOS in HBMEC, suggesting that HEPM increased NO production via phosphorylation-dependent activation of Akt and eNOS. In conclusion, HEPM prevents cerebral

Generic, network schema agnostic sparse tensor factorization for single-pass clustering of heterogeneous information networks.

Science.gov (United States)

Wu, Jibing; Meng, Qinggang; Deng, Su; Huang, Hongbin; Wu, Yahui; Badii, Atta

2017-01-01

Heterogeneous information networks (e.g. bibliographic networks and social media networks) that consist of multiple interconnected objects are ubiquitous. Clustering analysis is an effective method to understand the semantic information and interpretable structure of the heterogeneous information networks, and it has attracted the attention of many researchers in recent years. However, most studies assume that heterogeneous information networks usually follow some simple schemas, such as bi-typed networks or star network schema, and they can only cluster one type of object in the network each time. In this paper, a novel clustering framework is proposed based on sparse tensor factorization for heterogeneous information networks, which can cluster multiple types of objects simultaneously in a single pass without any network schema information. The types of objects and the relations between them in the heterogeneous information networks are modeled as a sparse tensor. The clustering issue is modeled as an optimization problem, which is similar to the well-known Tucker decomposition. Then, an Alternating Least Squares (ALS) algorithm and a feasible initialization method are proposed to solve the optimization problem. Based on the tensor factorization, we simultaneously partition different types of objects into different clusters. The experimental results on both synthetic and real-world datasets have demonstrated that our proposed clustering framework, STFClus, can model heterogeneous information networks efficiently and can outperform state-of-the-art clustering algorithms as a generally applicable single-pass clustering method for heterogeneous network which is network schema agnostic.

Neurologic Injury and Cerebral Blood Flow In Single Ventricles Throughout Staged Surgical Reconstruction

Science.gov (United States)

Fogel, Mark A.; Li, Christine; Elci, Okan U.; Pawlowski, Tom; Schwab, Peter J.; Wilson, Felice; Nicolson, Susan C.; Montenegro, Lisa M.; Diaz, Laura; Spray, Thomas L.; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S.; Harris, Matthew A.; Whitehead, Kevin K.; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J.

2017-01-01

Background Single ventricle patients experience a high rate of brain injury and adverse neurodevelopmental outcome, however, the incidence of brain abnormalities throughout surgical reconstruction and its relationship with cerebral blood flow, oxygen delivery and carbon dioxide reactivity remains unknown. Methods Single ventricle patients were studied with MRI scans immediately prior to bidirectional Glenn (pre-BDG), prior to Fontan and then 3–9 months after Fontan reconstruction. Results One hundred and sixty eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age 4.8+1.7 months), 118 BDG (2.9+1.4 years) and 54 after Fontan (2.4+1.0 years). Non-acute ischemic white matter changes on T2 weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontans compared to pre-BDG (P<0.05). BDG patients has significantly higher CBF than Fontan patients. The odds of discovering brain injury adjusting for surgical stage as well as 2 or more co-existing lesions within a patient all decreased (63–75% and 44% respectively) with increasing amount of cerebral blood flow (P<0.05). In general, there was no association of oxygen delivery (with the exception of ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Conclusion Significant brain abnormalities are commonly present in single ventricle patients and detection of these lesions increase as children progress through staged surgical reconstruction with multiple co-existing lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater CBF than Fontan patients and that there exists an inverse association of various indices of CBF with these brain lesions, however, CO2 reactivity, oxygen delivery (with one exception) were not associated with brain lesion development. PMID:28031423

Affinity of Iresine herbstii and Brugmansia arborea extracts on different cerebral receptors.

Science.gov (United States)

Nencini, Cristina; Cavallo, Federica; Bruni, Giancarlo; Capasso, Anna; De Feo, Vincenzo; De Martino, Laura; Giorgi, Giorgio; Micheli, Lucia

2006-05-24

Iresine herbstii Hook. (Amaranthaceae) and Brugmansia arborea (L.) Lagerheim (Solanaceae) are used in the northern Peruvian Andes for magic-therapeutical purposes. The traditional healers use Iresine herbstii with the ritual aim to expel bad spirits from the body. Furthermore, Iresine herbstii was used in association with other plants, such as Trichocereus pachanoi Britt. et Rose, for divination, to diagnose diseases, and to take possession of another identity. Also, species of Brugmansia have been reported to be used during ritual practices for magical and curative purposes. Given the above evidence, the aim of the present study is to evaluate if the central effects of Iresine herbstii and Brugmansia arborea could be associated with interaction with SNC receptors. Two Iresine herbstii extracts (methanolic and aqueous) and one Brugmansia arborea aqueous extract were tested for in vitro affinity on 5-HT(1A), 5-HT(2A), 5-HT(2C), D1, D2, alpha(1), and alpha(2) receptors by radioligand binding assays. The biological materials for binding assay (cerebral cortex) were taken from male Sprague-Dawley rats. The extracts affinity for receptors is definite as inhibition percentage of radioligand/receptor binding and measured as the radioactivity of remaining complex radioligand/receptor. The data obtained for Iresine extracts have shown a low affinity for the 5-HT(1A) receptor and no affinity for 5-HT(2A) receptor. Otherwise the methanolic extract showed affinity for 5-HT(2C) receptor (IC(50): 34.78 microg/ml) and for D1 receptor (IC(50): 19.63 microg/ml), instead the Iresine aqueous extract displayed a lower affinity for D1 (48.3% at the maximum concentration tested) and a higher value of affinity for D2 receptors (IC(50): 32.08 microg/ml). The Brugmansia aqueous extract displayed affinity for D1 receptors (IC(50): 17.68 microg/ml), D2 receptors (IC(50): 15.95 microg/ml) and weak affinity for the serotoninergic receptors. None of the three extracts showed relevant affinity

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles.

Science.gov (United States)

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Diaz Berenstein, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2015-08-01

Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was pflow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, pflow was higher prior to BDG than in other stages. There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. NCT02135081. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Neuroprotective effect of Buddleja officinalis extract on transient middle cerebral artery occlusion in rats.

Science.gov (United States)

Lee, Dae-Hee; Ha, Nina; Bu, Yung-Min; Choi, Hyoung Il; Park, Yoo Guen; Kim, Yoon Bum; Kim, Mi-Yeon; Kim, Hocheol

2006-08-01

The flower buds of Buddleja officinalis MAXIM (Loganiaceae) are used to treat headache and inflammatory diseases in traditional Korean medicine. In the present study, the neuroprotective effects of the methanolic extract of B. officinalis (BOME) and of its hexane fraction (BOHF) were investigated in a middle cerebral artery occlusion (MCAo, 120 min occlusion, 24 h reperfusion) Sprague-Dawley rat model. BOME or BOHF (100 mg/kg, p.o.) was twice administered 30 min before the onset of MCAo and 2 h after reperfusion. BOME and BOHF treated groups showed infarct volumes reduced by 33.9% and 68.2%, respectively, at 2 h occlusion. In BOHF treated animals, cyclooxygenase-2 and iNOS inductions were inhibited in ischemic hemispheres at both the mRNA and protein levels. Furthermore, in vitro studies showed that BOME and BOHF both inhibited LPS-induced nitric oxide production in BV-2 mouse microglial cells. These results suggest that the anti-inflammatory and the microglial activation inhibitory effects of B. officinalis extract may contribute to its neuroprotective effects in brain ischemia.

Continuous-wave sodium D2 resonance radiation generated in single-pass sum-frequency generation with periodically poled lithium niobate.

Science.gov (United States)

Yue, J; She, C-Y; Williams, B P; Vance, J D; Acott, P E; Kawahara, T D

2009-04-01

With two cw single-mode Nd:YAG lasers at 1064 and 1319 nm and a periodically poled lithium niobate crystal, 11 mW of 2 kHz/100 ms bandwidth single-mode tunable 589 nm cw radiation has been detected using single-pass sum-frequency generation. The demonstrated conversion efficiency is approximately 3.2%[W(-1) cm(-1)]. This compact solid-state light source has been used in a solid-state-dye laser hybrid sodium fluorescence lidar transmitter to measure temperatures and winds in the upper atmosphere (80-105 km); it is being implemented into the transmitter of a mobile all-solid-state sodium temperature and wind lidar under construction.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

Science.gov (United States)

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Berenstein, Laura Diaz; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2016-01-01

Objective Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. Methods 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3–9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. Results A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=−0.67–−0.70 for all patients on room air, p<0.01 and R=−0.49–−0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. Conclusions There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. Trial Registration Number NCT02135081. PMID:26048877

Cerebral blood flow single-photon emission tomography with {sup 123}I-IMP in vascular dementia

Energy Technology Data Exchange (ETDEWEB)

Kawahata, Nobuya; Gotoh, Chiharu; Yokoyama, Sakura; Daitoh, Nobuyuki [Narita Memorial Hospital, Toyohashi, Aichi (Japan)

2001-06-01

Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P-{sup 123}I-iodoamphetamine ({sup 123}I-IMP) and SPECT imager. The mCBF in VD was 27.6{+-}5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6{+-}6.1 ml/100 g/min and 32.5{+-}5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

EXTRACTION OF BUILIDNG SHAPE FROM TANDEM-X DATA

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A. Thiele

2013-05-01

Full Text Available Large scale mapping and modeling of urban areas is requested in many fields, especially in planning of energy supply and for change detection. For this purpose, SAR systems are highly attractive due to their independency of daytime and weather. The new satellite configuration of TerraSAR-X and TanDEM-X provides single-pass 3D mapping of the earth with unprecedented geometric resolution, allowing for improved detection and extraction of building positions and shapes. In this paper, single-pass interferograms of the TanDEM-X mission are utilized to automatically reconstruct buildings. To this purpose, first an interferogram is calculated from a TanDEM pair. Then, a new detector is applied that analyses phase ramps in the interferogram. Phase ramps being a pattern typically observable in layover areas of buildings, the detector is able to indicate building locations. Afterwards, the detected building areas are analyzed in more detail to extract width, length, and height of the buildings. Last, an edge detector is applied to deduce the building shapes. The reconstruction results are compared with reference data.

Detection and volume estimation of embolic air in the middle cerebral artery using transcranial Doppler sonography.

Science.gov (United States)

Bunegin, L; Wahl, D; Albin, M S

1994-03-01

Cerebral embolism has been implicated in the development of cognitive and neurological deficits following bypass surgery. This study proposes methodology for estimating cerebral air embolus volume using transcranial Doppler sonography. Transcranial Doppler audio signals of air bubbles in the middle cerebral artery obtained from in vivo experiments were subjected to a fast-Fourier transform analysis. Audio segments when no air was present as well as artifact resulting from electrocautery and sensor movement were also subjected to fast-Fourier transform analysis. Spectra were compared, and frequency and power differences were noted and used for development of audio band-pass filters for isolation of frequencies associated with air emboli. In a bench model of the middle cerebral artery circulation, repetitive injections of various air volumes between 0.5 and 500 microL were made. Transcranial Doppler audio output was band-pass filtered, acquired digitally, then subjected to a fast-Fourier transform power spectrum analysis and power spectrum integration. A linear least-squares correlation was performed on the data. Fast-Fourier transform analysis of audio segments indicated that frequencies between 250 and 500 Hz are consistently dominant in the spectrum when air emboli are present. Background frequencies appear to be below 240 Hz, and artifact resulting from sensor movement and electrocautery appears to be below 300 Hz. Data from the middle cerebral artery model filtered through a 307- to 450-Hz band-pass filter yielded a linear relation between emboli volume and the integrated value of the power spectrum near 40 microL. Detection of emboli less than 0.5 microL was inconsistent, and embolus volumes greater than 40 microL were indistinguishable from one another. The preliminary technique described in this study may represent a starting point from which automated detection and volume estimation of cerebral emboli might be approached.

Cerebral blood flow and oxygen metabolism after subarachnoid hemorrhage

International Nuclear Information System (INIS)

Ito, Hidemichi; Sakurai, Takashi; Hayashi, Tatsuo; Hashimoto, Takuo

2004-01-01

The mechanism of reduction of cerebral circulation in the early phase of aneurysmal subarachnoid hemorrhage (SAH) has not yet been clarified. Previous studies have variously indicated that cerebral blood flow (CBF) reduction may be due to cerebral vasospasm, an elevation in intracranial pressure (ICP), constriction of intraparenchymal arterioles, or metabolic reduction. The aim of this study is to investigate the relationship between cerebral circulation and oxygen metabolism. In 36 patients with aneurysmal SAH, the values of mean cerebral blood flow (mCBF), cerebral metabolic rate of oxygen (GMRO 2 ) and oxygen extraction fraction (OEF) were measured by using single photon emission computed tomography (SPECT) with arterial blood drawing and oxygen saturation of internal jugular bulb blood (SjO 2 ) in the acute stage (1-3 days after onset) and the spasm stage (7-10 days after onset). The patients in our study were selected by using the following criteria: no history of cerebrovascular or cardiopulmonary diseases; under the age of 70; the ruptured aneurysm was treated by clipping or coil embolization within 72 hours after onset; no symptoms of cerebral vasospasm; no signs of cerebral ischemic change on CT scans. These patients were divided into 2 groups according to the World Federation of Neurological Surgeons (WFNS) grading classification; the mild group (Grades I and II) consisted of 27 cases and the severe group (Grade IV) consisted of 9 cases. We studied differences in mCBF CMRO 2 , and OEF between the mild group and severe group. In the mild group, mCBF, CMRO 2 , and OEF were significantly higher than in the severe group during both the acute and the spasm stage. Also mCBF showed a direct correlation with CMRO 2 . All the patients were kept under the following conditions: the bed was positioned so that the upper body was raised at an angle at 30 deg; blood pressure was maintained at 130-150 mmHg and PaCO 2 of arterial blood was maintained at 35-40 mmHg; ICP

The Influence of Age at Single-Event Multilevel Surgery on Outcome in Children with Cerebral Palsy Who Walk with Flexed Knee Gait

Science.gov (United States)

Svehlik, Martin; Steinwender, Gerhard; Kraus, Tanja; Saraph, Vinay; Lehmann, Thomas; Linhart, Wolfgang E.; Zwick, Ernst B.

2011-01-01

Aim: Information on the timing and long-term outcome of single-event multilevel surgery in children with bilateral spastic cerebral palsy (CP) walking with flexed knee gait is limited. Based on our clinical experience, we hypothesized that older children with bilateral spastic CP would benefit more from single-event multilevel surgery than younger…

Cerebral perfusion inhomogeneities in schizophrenia demonstrated with single photon emission computed tomography and Tc99m-hexamethylpropyleneamineoxim

International Nuclear Information System (INIS)

Bajc, M.; Basic, M.; Topuzovic, N.; Babic, C.; Medved, V.

1989-01-01

Cerebral blood flow was measured in relative terms with Tc99m-hexamethylpropyleneamineoxim (HMPAO) and single photon emission computed tomography (SPECT) in 28 female schizophrenic patients (20 acute and 8 chronic) classified according to DSM-III. Eleven normals served as controls. The acute patients were classified according to positive and negative symptoms. Patients with predominantly positive symptoms showed by and large normal and homogeneous cerebral isotope uptake. Those with negative symptoms, and the chronic patients, showed inhomogeneous tracer uptake with multiple regions of hypoperfusion in slices 4-6 cm above the orbitomeatal line. The findings support in principle the notion that schizophrenia with negative or chronic symptoms does not affect the whole brain homogeneously. Brain imaging with Tc99m-HMPAO and SPECT might be used to distinguish various types of schizophrenia. (author)

Measurement of cerebral blood flow by single photon emission computed tomography in cases of internal carotid artery occlusion

Energy Technology Data Exchange (ETDEWEB)

Sunada, Ichiro [Osaka City Univ. (Japan). Faculty of Medicine

1989-06-01

Cerebral blood flow (CBF) was measured with {sup 133}xenon inhalation and single photon emission computed tomography in 33 cases of internal carotid artery occlusion, in the resting state and 25 minutes after acetazolamide administration. The patient population consisted of 24 males and nine females with a mean age of 57 years, who presented with transient ischemic attacks or stroke. Acetazolamide inhibits carbonic anhydrase, and CBF increases as a result of dilatation of cerebral arteries due to CO{sub 2} accumulation. The mean CBF was 46 ml/100 g/min on the affected hemisphere and 56 ml/100 g/min on the unaffected hemisphere. The mean CBF value obtained by the same method in 10 normal volunteers was 55 ml/100 g/min. The average increase in CBF after acetazolamide administration was 9% on the affected side and 17% on the unaffected side. The average increase in 10 normal volunteers was 32%. The reduced cerebral arterial reactivity to acetazolamide administration was bilateral in the patient group, suggesting that the cerebral arteries were dilated so as to maintain normal CBF. Extra-intracranial (EC-IC) bypass surgery was performed in nine patients. Preoperatively, the mean CBF was 48 ml/100 g/min on the affected side and 57 ml/100 g/min on the unaffected side. With postoperative acetazolamide administration, the percent increase in CBF rose from 13% to 22% on the affected side and from 17% to 23% on the unaffected side. The bilateral change toward normal in cerebral arterial reactivity to acetazolamide indicates that the dilated cerebral arteries returned to normal after EC-IC bypass surgery. This suggests that bypass surgery is effective in patients with internal carotid artery occlusion in whom ischemia is caused only by hemodynamic factors, and that measurement of CBF via acetazolamide loading is useful in identifying appropriate candidates for bypass surgery.

Experimental and simulation studies on a single pass, double duct solar air heater

Energy Technology Data Exchange (ETDEWEB)

Forson, F.K. [Kwame Nkrumah Univ. of Science and Technology, Dept. of Mechanical Engineering, Kumasi (Ghana); Rajakaruna, H. [De Montfort Univ., School of Engineering and Technology, Leicester (United Kingdom)

2003-05-01

A mathematical model of a single pass, double duct solar air heater (SPDDSAH) is described. The model provides a design tool capable of predicting: incident solar radiation, heat transfer coefficients, mean air flow rates, mean air temperature and relative humidity at the exit. Results from the simulation are presented and compared with experimental ones obtained on a full scale air heater and a small scale laboratory one. Reasonable agreement between the predicted and measured values is demonstrated. Predicted results from a parametric study are also presented. It is shown that significant improvement in the SPDDSAH performance can be obtained with an appropriate choice of the collector parameters and the top to bottom channel depth ratio of the two ducts. The air mass flow rate is shown to be the dominant factor in determining the overall efficiency of the heater. (Author)

Optimum Energy Extraction from Coherent Vortex Rings Passing Tangentially Over Flexible Plates

Science.gov (United States)

Pirnia, Alireza; Browning, Emily A.; Peterson, Sean D.; Erath, Byron D.

2017-11-01

Coherent vortical structures can incite self-sustained oscillations in flexible membranes. This concept has recently gained interest for energy extraction from ambient environments. In this study the special case of a vortex ring passing tangentially over a cantilevered flexible plate is investigated. This problem is governed by the Kirchhoff-Love plate equation, which can be expressed in terms of a non-dimensional mass parameter of the plate, non-dimensional pressure loading induced by the vortex ring, and a Strouhal (St) number which expresses the duration of pressure loading relative to the period of plate oscillation. For a plate with a fixed mass parameter immersed in a fluid environment, the St number specifies the beam dynamics and the energy exchange process. The aim of this study is to identify the St number corresponding to maximum energy exchange between plates and vortex rings. The energy exchange process between the vortex ring and the plate is investigated over a range of 0.3 transfer is reported in each case and an empirical correlation is provided for predictive purposes. Supported by the National Science Foundation (NSF) under Grant No. CBET-1511761, and the Natural Sciences and Engineering Research Council of Canada (NSERC), under Grant No. 05778-2015.

[Study on biopharmaceutics classification system for Chinese materia medica of extract of Huanglian].

Science.gov (United States)

Liu, Yang; Yin, Xiu-Wen; Wang, Zi-Yu; Li, Xue-Lian; Pan, Meng; Li, Yan-Ping; Dong, Ling

2017-11-01

One of the advantages of biopharmaceutics classification system of Chinese materia medica (CMMBCS) is expanding the classification research level from single ingredient to multi-components of Chinese herb, and from multi-components research to holistic research of the Chinese materia medica. In present paper, the alkaloids of extract of huanglian were chosen as the main research object to explore their change rules in solubility and intestinal permeability of single-component and multi-components, and to determine the biopharmaceutical classification of extract of Huanglian from holistic level. The typical shake-flask method and HPLC were used to detect the solubility of single ingredient of alkaloids from extract of huanglian. The quantitative research of alkaloids in intestinal absorption was measured in single-pass intestinal perfusion experiment while permeability coefficient of extract of huanglian was calculated by self-defined weight coefficient method. Copyright© by the Chinese Pharmaceutical Association.

Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)

International Nuclear Information System (INIS)

Ichiseki, Hajime; Terashi, Akiro; Hamamoto, Makoto; Miyazaki, Tokuzo.

1995-01-01

We have performed single photon emission computed tomography (SPECT) with 99m Tc-hexamethylpropylene amineoxime (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in status epileptics (SE) caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in radio isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular diseases, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEC but also SPECT scans when making a diagnosis of SE. (author)

Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)

Energy Technology Data Exchange (ETDEWEB)

Ichiseki, Hajime; Terashi, Akiro [Nippon Medical School, Tokyo (Japan); Hamamoto, Makoto; Miyazaki, Tokuzo

1995-12-01

We have performed single photon emission computed tomography (SPECT) with {sup 99m}Tc-hexamethylpropylene amineoxime (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in status epileptics (SE) caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in radio isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular diseases, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEC but also SPECT scans when making a diagnosis of SE. (author).

A Unified Algorithm for Channel Imbalance and Antenna Phase Center Position Calibration of a Single-Pass Multi-Baseline TomoSAR System

Directory of Open Access Journals (Sweden)

Yuncheng Bu

2018-03-01

Full Text Available The multi-baseline synthetic aperture radar (SAR tomography (TomoSAR system is employed in such applications as disaster remote sensing, urban 3-D reconstruction, and forest carbon storage estimation. This is because of its 3-D imaging capability in a single-pass platform. However, a high 3-D resolution of TomoSAR is based on the premise that the channel imbalance and antenna phase center (APC position are precisely known. If this is not the case, the 3-D resolution performance will be seriously degraded. In this paper, a unified algorithm for channel imbalance and APC position calibration of a single-pass multi-baseline TomoSAR system is proposed. Based on the maximum likelihood method, as well as the least squares and the damped Newton method, we can calibrate the channel imbalance and APC position. The algorithm is suitable for near-field conditions, and no phase unwrapping operation is required. The effectiveness of the proposed algorithm has been verified by simulation and experimental results.

A MISO-ARX-Based Method for Single-Trial Evoked Potential Extraction

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Nannan Yu

2017-01-01

Full Text Available In this paper, we propose a novel method for solving the single-trial evoked potential (EP estimation problem. In this method, the single-trial EP is considered as a complex containing many components, which may originate from different functional brain sites; these components can be distinguished according to their respective latencies and amplitudes and are extracted simultaneously by multiple-input single-output autoregressive modeling with exogenous input (MISO-ARX. The extraction process is performed in three stages: first, we use a reference EP as a template and decompose it into a set of components, which serve as subtemplates for the remaining steps. Then, a dictionary is constructed with these subtemplates, and EPs are preliminarily extracted by sparse coding in order to roughly estimate the latency of each component. Finally, the single-trial measurement is parametrically modeled by MISO-ARX while characterizing spontaneous electroencephalographic activity as an autoregression model driven by white noise and with each component of the EP modeled by autoregressive-moving-average filtering of the subtemplates. Once optimized, all components of the EP can be extracted. Compared with ARX, our method has greater tracking capabilities of specific components of the EP complex as each component is modeled individually in MISO-ARX. We provide exhaustive experimental results to show the effectiveness and feasibility of our method.

[Advances in genetic research of cerebral palsy].

Science.gov (United States)

Wang, Fang-Fang; Luo, Rong; Qu, Yi; Mu, De-Zhi

2017-09-01

Cerebral palsy is a group of syndromes caused by non-progressive brain injury in the fetus or infant and can cause disabilities in childhood. Etiology of cerebral palsy has always been a hot topic for clinical scientists. More and more studies have shown that genetic factors are closely associated with the development of cerebral palsy. With the development and application of various molecular and biological techniques such as chromosome microarray analysis, genome-wide association study, and whole exome sequencing, new achievements have been made in the genetic research of cerebral palsy. Chromosome abnormalities, copy number variations, susceptibility genes, and single gene mutation associated with the development of cerebral palsy have been identified, which provides new opportunities for the research on the pathogenesis of cerebral palsy. This article reviews the advances in the genetic research on cerebral palsy in recent years.

Features to validate cerebral toxoplasmosis

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Carolina da Cunha Correia

2013-06-01

Full Text Available Introduction Neurotoxoplasmosis (NT sometimes manifests unusual characteristics. Methods We analyzed 85 patients with NT and AIDS according to clinical, cerebrospinal fluid, cranial magnetic resonance, and polymerase chain reaction (PCR characteristics. Results In 8.5%, focal neurological deficits were absent and 16.4% had single cerebral lesions. Increased sensitivity of PCR for Toxoplasma gondii DNA in the central nervous system was associated with pleocytosis and presence of >4 encephalic lesions. Conclusions Patients with NT may present without focal neurological deficit and NT may occur with presence of a single cerebral lesion. Greater numbers of lesions and greater cellularity in cerebrospinal fluid improve the sensitivity of PCR to T gondii.

Effect of a ballast zone on the hydraulic stability of a single-pass steam generator

International Nuclear Information System (INIS)

Belyakov, I.I.; Kvetnyj, M.A.; Loginov, D.A.

1985-01-01

A new mechanism of hydraulic instability of boiling channels with convection heating which reveals in the presence of a developed ballast zone at decreased loads of a counterflan steam generator operation is considered. It is shown that for the certain combinations of thermal and technical parameters pulsation regimes caused by the ballast zone displacement over the heating surface are possible. The parameter relation at which the ballast zone position becomes unstable is obtained. The effect of the ballast zone on the statis steam generator stability is established. A mechanism of whole-circuit pulsations revealed when developing start regimes of single-pass steam generator heated with liquid sodium is explained from the positions of the instability

Topical perfluorodecalin resolves immediate whitening reactions and allows rapid effective multiple pass treatment of tattoos.

Science.gov (United States)

Reddy, Kavitha K; Brauer, Jeremy A; Anolik, Robert; Bernstein, Leonard; Brightman, Lori; Hale, Elizabeth; Karen, Julie; Weiss, Elliot; Geronemus, Roy G

2013-02-01

Laser tattoo removal using multiple passes per session, with each pass delivered after spontaneous resolution of whitening, improves tattoo fading in a 60-minute treatment time. Our objective was to evaluate the safety and efficacy of topical perfluorodecalin (PFD) in facilitating rapid effective multiple-pass tattoo removal. In a randomized, controlled study using Q-switched ruby or Nd:YAG laser, 22 previously treated tattoos were treated with 3 passes using PFD to resolve whitening after each pass ("R0 method"). In previously untreated symmetric tattoos, seven were treated over half of the tattoo with the R20 method, and the opposite half with 4 passes using PFD (R0 method); two were treated over half with a single pass and the opposite half with 4 passes using PFD (R0 method); and six treated over half with a single pass followed by PFD and the opposite half with a single pass alone. Blinded dermatologists rated tattoo fading at 1-3 months. Optical coherence tomography (OCT) imaging of whitening was performed in two tattoos. Topical PFD clinically resolved immediate whitening reactions within a mean 5 seconds (range 3-10 seconds). Tattoos treated with the R0 method demonstrated excellent fading in an average total treatment time of 5 minutes. Tattoo areas treated with the R0 method demonstrated equal fading compared to the R20 method, and improved fading compared to a single pass method. OCT imaging of whitening demonstrated epidermal and dermal hyper-reflective "bubbles" that dissipated until absent at 9-10 minutes after PFD application, and at 20 minutes without intervention. Multiple-pass tattoo removal using PFD to deliver rapid sequential passes (R0 method) appears equally effective as the R20 method, in a total treatment time averaging 5 minutes, and more effective than single pass treatment. OCT-visualized whitening-associated "bubbles," upon treatment with PFD, resolve twice as rapidly as spontaneous resolution. Copyright © 2012 Wiley

Single-stage micro-scale solvent extraction in parallel microbore tubes using MDIMJ

International Nuclear Information System (INIS)

Darekar, Mayur; Singh, K.K.; Joshi, J.M.; Mukhopadhyay, S.; Shenoy, K.T.

2016-01-01

Single-stage micro-scale solvent extraction of U(VI) from simulated lean streams is explored using micro-scale contactor comprising of a MDIMJ (Monoblock Distributor with Integrated Microfluidic Junction) and PTFE microbore tubes. 30% (v/v) TBP in dodecane has been used as the extracting phase. The objective of the study is to demonstrate numbering up approach for scale-up of micro-scale extraction using indigenously conceptualized and fabricated MDIMJ. First the performance of MIDIMJ for equal flow distribution is tested. Then the effects of inlet flow rate and O/A ratio on stage efficiency and percentage extraction are studied. The experiments show that it is easy to scale-up single-stage micro-scale solvent extraction by using MDIMJ for numbering up approach. Maximum capacity tested is 4.8 LPH. With O/A = 2/1, more than 90% extraction is achieved in a very short contact time of less than 3s. The study thus demonstrates possibility of process intensification and easy scale-up of micro-scale solvent extraction

Neuroprotective Effect of Matricaria chamomilla Extract on Motor Dysfunction Induced by Transient Global Cerebral Ischemia and Reperfusion in Rat

Directory of Open Access Journals (Sweden)

Azam Moshfegh

2017-09-01

Full Text Available Background Stroke can cause paralysis, muscle weakness, and loss of balance that may affect walking and routine activities. Objectives The aim of this study was to evaluate the effect of ethyl alcohol extract of Matricaria chamomilla on cerebral ischemia-induced motor dysfunctions in rats. Methods In this experimental study, forty two male Wistar rats were divided into 6 groups consisting of control group, sham group, ischemia/reperfusion group and three treatment groups [treated with 50, 100, and 200 mg/kg doses of M. chamomilla extract and undergoing ischemia/reperfusion(I/R]. Motor coordination and balance were evaluated using Rotarod test. Total antioxidant capacity, malondialdehyde (MDA, and nitric oxide (NO levels of serum and brain were also determined. Results The extract of M. chamomilla significantly improved I/R-induced motor dysfunction. Induction of I/R led to increase serum MDA, while the extract of M, chamomlla significantly reduced it. Administration all doses of M. chamomilla extract to the ischemic rats did not reduce the hippocampus MDA levels (P > 0.05. The extract of M. chamomilla at dose of 200 mg/kg slightly decreased cortex MDA (P > 0.01. It had no significant effects on the total antioxidant capacity of the brain (hippocampus and cortex and serum. Injection of Matricaria chamomilla extract also did not change serum NO level. Conclusions Our findings suggested that the Matricaria chamomilla extract could improve motor dysfunction.

Single Pass Collider Memo: Gradient Perturbations of the SLC arc

Energy Technology Data Exchange (ETDEWEB)

Weng, W.T.; Sands, M.; /SLAC

2016-12-16

As the beam passes through the arcs, the gradient it encounters at each magnet differs from the design value. This deviation may be in part random and in part systematic. In this note we make estimates of the effects to be expected from both kinds of errors.

Single Pass Stripline Beam Position Monitor Design, Fabrication and Commissioning

Directory of Open Access Journals (Sweden)

McKinlay J.

2012-10-01

Full Text Available To monitor the position of the electron beam during transport from the Booster Synchrotron to the Storage Ring at the Australian Synchrotron, a stripline Beam Position Monitor (BPM has been designed, fabricated and installed in-house. The design was based on an existing stripline in the Booster and modified for the transfer line with a particular emphasis on ensuring the line impedance is properly matched to the detector system. The initial bench tests of a prototype stripline showed that the fabrication of the four individual striplines in the BPM was made precisely, each with a measured standing wave ratio (SWR of 1.8 at 500 MHz. Further optimization for impedance matching will be done for new stripline BPMs. The linearity and gain factor was measured with the detector system. The detector system that digitizes the signals is an Instrumentation Technologies Brilliance Single Pass [1]. The results show an error of 1 mm at an offset (from the electrical centre of 10 mm when a linear gain factor is assumed and an RMS noise of ~150 um that decreases to < 10 um with increasing signal intensity. The results were under our requirements for the transport line. The commissioning results of the stripline will also be presented showing a strong signal for an electron beam with an estimated integrated charge of ~50 nC with a position stability of 28 um (horizontal and 75 um (vertical.

Single Pass Stripline Beam Position Monitor Design, Fabrication and Commissioning

Science.gov (United States)

Tan, Y.-R. E.; Wang, D.; Van Garderen, E.; McKinlay, J.

2012-10-01

To monitor the position of the electron beam during transport from the Booster Synchrotron to the Storage Ring at the Australian Synchrotron, a stripline Beam Position Monitor (BPM) has been designed, fabricated and installed in-house. The design was based on an existing stripline in the Booster and modified for the transfer line with a particular emphasis on ensuring the line impedance is properly matched to the detector system. The initial bench tests of a prototype stripline showed that the fabrication of the four individual striplines in the BPM was made precisely, each with a measured standing wave ratio (SWR) of 1.8 at 500 MHz. Further optimization for impedance matching will be done for new stripline BPMs. The linearity and gain factor was measured with the detector system. The detector system that digitizes the signals is an Instrumentation Technologies Brilliance Single Pass [1]. The results show an error of 1 mm at an offset (from the electrical centre) of 10 mm when a linear gain factor is assumed and an RMS noise of ~150 um that decreases to < 10 um with increasing signal intensity. The results were under our requirements for the transport line. The commissioning results of the stripline will also be presented showing a strong signal for an electron beam with an estimated integrated charge of ~50 nC with a position stability of 28 um (horizontal) and 75 um (vertical).

The thermal performance of the two-pass, two-glass-cover solar air heater

Energy Technology Data Exchange (ETDEWEB)

Persad, P.; Sateunanathan, S.

1983-08-01

Analytic models are developed for the performance prediction of a two-glass-cover solar air heater operated in both the single-pass and two-pass modes. It is shown that the two-pass mode of operation is superior to the single-pass mode of operation over the range of collector inlet temperatures considered. This is seen to be mainly due to the fact that, in the two-pass mode of operation, the outer glass cover is cooled by the working fluid, thereby reducing the top losses. It is also shown that the performance in the two-pass mode of operation is independent of length, over the range of collector lengths considered, and that a critical plate spacing, dependent on the temperature level of operation of the collector, is indicated. Predicted values of performance are in good agreement with experimental results.

The methods of PET cerebral imaging in focus localizing of epilepsy

International Nuclear Information System (INIS)

Bai Xia; Wang Xuemei

2009-01-01

Epilepsy is a very complicate and synthetic disease which influence patients intelligence and daily life acutely. But the cure rate of epilepsy is much low. One of the results is precise localization of disease which result in epilepsy. Today the main methods are electroencephalogram, magnetic resonance imaging, magnetic resonance spectroscopy and PET cerebral imaging. PET cerebral imaging can locate epileptic foci of epilepsy from the brain organization metabolism, blood, the bio-chemical, function and oxygen consume, the chemistry pass quality and nerve receptor. It raises the rate of checking the epileptic foci and indicates a direction for the next treatments of epilepsy. (authors)

Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

Science.gov (United States)

Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

2017-02-01

General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

A single-step method for rapid extraction of total lipids from green microalgae.

Directory of Open Access Journals (Sweden)

Martin Axelsson

Full Text Available Microalgae produce a wide range of lipid compounds of potential commercial interest. Total lipid extraction performed by conventional extraction methods, relying on the chloroform-methanol solvent system are too laborious and time consuming for screening large numbers of samples. In this study, three previous extraction methods devised by Folch et al. (1957, Bligh and Dyer (1959 and Selstam and Öquist (1985 were compared and a faster single-step procedure was developed for extraction of total lipids from green microalgae. In the single-step procedure, 8 ml of a 2∶1 chloroform-methanol (v/v mixture was added to fresh or frozen microalgal paste or pulverized dry algal biomass contained in a glass centrifuge tube. The biomass was manually suspended by vigorously shaking the tube for a few seconds and 2 ml of a 0.73% NaCl water solution was added. Phase separation was facilitated by 2 min of centrifugation at 350 g and the lower phase was recovered for analysis. An uncharacterized microalgal polyculture and the green microalgae Scenedesmus dimorphus, Selenastrum minutum, and Chlorella protothecoides were subjected to the different extraction methods and various techniques of biomass homogenization. The less labour intensive single-step procedure presented here allowed simultaneous recovery of total lipid extracts from multiple samples of green microalgae with quantitative yields and fatty acid profiles comparable to those of the previous methods. While the single-step procedure is highly correlated in lipid extractability (r² = 0.985 to the previous method of Folch et al. (1957, it allowed at least five times higher sample throughput.

Depth discrimination in acousto-optic cerebral blood flow measurement simulation

Science.gov (United States)

Tsalach, A.; Schiffer, Z.; Ratner, E.; Breskin, I.; Zeitak, R.; Shechter, R.; Balberg, M.

2016-03-01

Monitoring cerebral blood flow (CBF) is crucial, as inadequate perfusion, even for relatively short periods of time, may lead to brain damage or even death. Thus, significant research efforts are directed at developing reliable monitoring tools that will enable continuous, bed side, simple and cost-effective monitoring of CBF. All existing non invasive bed side monitoring methods, which are mostly NIRS based, such as Laser Doppler or DCS, tend to underestimate CBF in adults, due to the indefinite effect of extra-cerebral tissues on the obtained signal. If those are to find place in day to day clinical practice, the contribution of extra-cerebral tissues must be eliminated and data from the depth (brain) should be extracted and discriminated. Recently, a novel technique, based on ultrasound modulation of light was developed for non-invasive, continuous CBF monitoring (termed ultrasound-tagged light (UTL or UT-NIRS)), and shown to correlate with readings of 133Xe SPECT and laser Doppler. We have assembled a comprehensive computerized simulation, modeling this acousto-optic technique in a highly scattering media. Using the combination of light and ultrasound, we show how depth information may be extracted, thus distinguishing between flow patterns taking place at different depths. Our algorithm, based on the analysis of light modulated by ultrasound, is presented and examined in a computerized simulation. Distinct depth discrimination ability is presented, suggesting that using such method one can effectively nullify the extra-cerebral tissues influence on the obtained signals, and specifically extract cerebral flow data.

Hemodynamics in the cerebral cortex and basal ganglia

International Nuclear Information System (INIS)

Yamaguchi, Shinya; Fukuyama, Hidenao; Yamauchi, Hiroshi; Kimura, Jun

1991-01-01

We examined ten healthy volunteers using positron emission tomography (PET) in order to elucidate regional changes and correlations in the cerebral circulation and oxygen metabolism. We also studied eight lacunar stroke patients so as to disclose the influences of vascular risk factors and aging on the cerebral blood flow and metabolism. We can conclude from our result as follows: (1) Cerebral blood volume (CBV) was minimum in the basal ganglia and cerebral blood flow (CBF)/CBV ratio was higher than that of cerebral cortex in healthy volunteers; (2) CBF of gray matter in healthy volunteers correlated with CBV and cerebral metabolic rate of oxygen where oxygen extraction fraction inversely correlated with CBF, CBV, and CBF/CBV; and (3) the basal ganglia CBF/CBV ratio in lacunar stroke patients was lower than that of healthy volunteers. These findings suggested that the perfusion pressure in the basal ganglia was so high in the normal condition than the angionecrosis or occlusion in the perforating arteries would be induced, especially in the aged and hypertensive patients. (author)

Synchronous timing of multi-energy fast beam extraction during a single AGS cycle

International Nuclear Information System (INIS)

Gabusi, J.; Naase, S.

1985-01-01

Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating rf waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a ''hole'', which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous rf/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the ''hole'' in any desired location within the second extraction. The rf/12 signal is used also to synchronize experimenters triggers

Prediction of cerebral ischemia due to cerebral vasospasm in SAH using SPECT and 123I-IMP with acetazolamide test

International Nuclear Information System (INIS)

Nakagawara, Jyoji; Wada, Keiji; Takeda, Rihei; Usami, Takashi; Hashimoto, Ikuo; Shimazaki, Mitsuteru; Tanaka, Chiharu; Nakamura, Jun-ichi; Suematsu, Katsumi.

1989-01-01

To investigate the possibility of predicting cerebral ischemia due to cerebral vasospasm in subarachnoid hemorrhage (SAH), serial evaluation of the cerebral vasodilatory capacity by the acetazolamide test was conducted, using single photon emission computed tomography (SPECT) and N-isopropyl 123 I-p-iodoamphetamine (IMP), in 17 patients with cerebral vasospasm following early surgery for ruptured aneurysms. The degree of vasospasm measured on the angiograms was classified into the following three types; mild degree (25%>stenosis), moderate degree (25∼50% stenosis), and severe degree(50%cerebral vasodilatory capacity was preserved at the normal level during the period of vasospasm. In eight patients with asymptomatic vasospasm (moderate degree), a transient limitation of cerebral vasodiratory capacity was observed between the 6th and 16th day after a rupture of the cerebral aneurysm. In five patients with symptomatic vasospasm resulting in reversible ischemia, a marked limitation of cerebral vasodilatory capacity was noted between the 7th and 15th day, and a delayed recovery of cerebral vasodilatory capacity was observed. This reversibility of cerebral vasodilatory capacity in patients with cerebral vasospasm suggests that a local decrease of purfusion pressure due to cerebral vasospasm causes compensatory vasodilation of intraparenchymal arteries and the vasodilatory reaction to acetazolamide was limited until the release of the cerebral vasospasm. Therefore, assessment of cerebral vasodilatory capacity in SAH by the acetazolamide test might predict the appearance and continuation of potential ischemia of the brain caused by the reduction of perfusion pressure due to cerebral vasospasm. (J.P.N.)

Cerebral near infrared spectroscopy oximetry in extremely preterm infants

DEFF Research Database (Denmark)

Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas

2015-01-01

OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care unit...

Regional cerebral blood flow in acute stage with ischemic cerebrovascular disease by xenon-133 inhalation and single photon emission computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Kurokawa, Hiroyuki; Iino, Katsuro; Kojima, Hisashi; Saito, Hitoshi; Suzuki, Mikio; Watanabe, Kazuo; Kato, Toshiro

1987-05-01

Single photon emission computed tomography (SPECT) with xenon-133 inhalation method was undertaken within 48 hr after the onset in 68 patients with ischemic cerebrovascular disease. The results for regional cerebral blood flow (rCBF) were compared with concurrently available computed tomography (CT) scans. In patients with cerebral infarction, SPECT detected ischemic lesions earlier than CT, with the detectability being 92 %. The area with a decreased blood flow, as seen on SPECT, was more extensive than the low density area on CT, with a concomitant decrease in blood flow in the contralateral cerebral hemisphere. Crossed cerebellar diaschisis was associated with stenosis of the internal carotid artery in 50 % (7/14), and with stenosis of the middle cerebral artery in 35 % (9/26). Abnormal SPECT findings were seen in 47 % (8/17) of the patients with transient ischemic attack (TIA). Five TIA patients had a decreased rCBF on SPECT, which was not provided by CT scans. On the contrary, small infarct lesions in the cerebral basal ganglia, as observed in 4 patients, was not detected by SPECT, but detected by CT. This may imply the limitations of SPECT in the detection of deep-seated lesions of the cerebrum. The results led to the conclusion that SPECT can be performed safely even in acute, seriously ill patients to know changes in rCBF because it is noninvasive and is capable of being repeated in a short time. (Namekawa, K.).

A Tunable CW Orange Laser Based on a Cascaded MgO:PPLN Single-Pass Sum-Frequency Generation Module

OpenAIRE

Dismas K. Choge; Huai-Xi Chen; Bao-Lu Tian; Yi-Bin Xu; Guang-Wei Li; Wan-Guo Liang

2018-01-01

We report an all-solid-state continuous wave (CW) tunable orange laser based on cascaded single-pass sum-frequency generation with fundamental wavelengths at 1545.7 and 975.2 nm using two quasi-phase-matched (QPM) MgO-doped periodically poled lithium niobate (MgO:PPLN) crystals. Up to 10 mW of orange laser is generated in the cascaded module corresponding to a 10.4%/W nonlinear conversion efficiency. The orange output showed a temperature tuning rate of ~0.05 nm/°C, and the beam quality (M2) ...

Evaluation of radiation risk and work practices during cerebral interventions

Energy Technology Data Exchange (ETDEWEB)

Livingstone, Roshan S; Raghuram, L; Korah, Ipeson P; Raj, D Victor [Department of Radiodiagnosis, Christian Medical College, Vellore 632004 (India)

2003-09-01

This study was intended to evaluate radiation risk to patients during cerebral interventions and the contribution to this risk from work practices. Thirty nine patients undergoing cerebral interventions in a digital subtraction angiography suite were included in this study. Patients who underwent cerebral interventions were categorised into two groups according to the number of cerebral interventions performed on them, and their effective doses were calculated. The effective dose for patients undergoing a single cerebral intervention (group A) varied from 1.55 to 15.9 mSv and for multiple cerebral interventions (group B) varied from 16.52 to 43.52 mSv. Two patients who underwent multiple cerebral interventions (group B) had alopecia of the irradiated scalp.

Notes on basis band-pass circuits; Notes sur les circuits de base passe-bande

Energy Technology Data Exchange (ETDEWEB)

Ailloud, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-01

Resistor load amplifier stages, basic band-pass RC networks, conventional single-tuned circuits, have the same transfer function. Common properties and differences because diverse magnitude of parameters with proposed problems are exposed. Next the case of several cascaded stages (or networks) is examined when there is no reaction ones to another. (author) [French] Les etages amplificateurs a resistances, les circuits passe-bande RC elementaires, le circuit resonnant classique possedent la meme fonction de transfert. On fait ressortir les proprietes communes et les differences de comportement dues aux ordres de grandeur qu'il est possible de donner aux parametres en fonction des problemes a resoudre. On examine ensuite le cas de plusieurs etages (ou de plusieurs circuits) en cascade lorsqu'ils ne reagissent pas les uns sur les autres. (auteur)

Design and evaluation of radiotracers for determination of regional cerebral blood flow with PET

International Nuclear Information System (INIS)

Lambrecht, R.M.; Duncan, C.C.; Shiue, C.Y.

1982-01-01

The tracer kinetics of 4-Fluoro( 18 F)-, 4-Bromo( 82 Br)- and 4-Iodo( 125 I)-antipyrine and 15 O-water were compared in a cat or baboon animal model. First-pass cerebral extraction and clearance with alterations in PaCO 2 were measured for whole brain. The Renkin/Crone model was used to evaluate brain capillary permeability-surface area product for 4- 18 FAP in cats. Positron-emission-tomographic measurements required development of an instrument and technique for control of the arterial concentration of the radiotracer as a ramp function, so that tracer concentration changes due to radioactive decay or altered physiological processes could be accurately described with PET. Pharmacokinetic and tissue-distribution studies in cats were used to determine dosimetry for 4- 18 FAP. 4-Bromoantipyrine labeled with 78 Br (t = 6.5 m) is suggested as a tracer for determination of rCBF with PET

Capacitive deionization of arsenic-contaminated groundwater in a single-pass mode.

Science.gov (United States)

Fan, Chen-Shiuan; Liou, Sofia Ya Hsuan; Hou, Chia-Hung

2017-10-01

A single-pass-mode capacitive deionization (CDI) reactor was used to remove arsenic from groundwater in the presence of multiple ions. The CDI reactor involved an applied voltage of 1.2 V and six cell pairs of activated carbon electrodes, each of which was 20 × 30 cm 2 . The results indicate that this method achieved an effluent arsenic concentration of 0.03 mg L -1 , which is lower than the arsenic concentration standard for drinking water and irrigation sources in Taiwan, during the charging stage. Additionally, the ability of the CDI to remove other coexisting ions was studied. The presence of other ions has a significant influence on the removal of arsenic from groundwater. From the analysis of the electrosorption selectivity, the preference for anion removal could be ordered as follows: NO 3 -  > SO 4 2-  > F -  > Cl - >As. The electrosorption selectivity for cations could be ordered as follows: Ca 2+  > Mg 2+  > Na +  ∼ K + . Moreover, monovalent cations can be replaced by divalent cations at the electrode surface in the later period of the electrosorption stage. Consequently, activated carbon-based capacitive deionization is demonstrated to be a high-potential technology for remediation of arsenic-contaminated groundwater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phenobarbital and neonatal seizures affect cerebral oxygen metabolism: a near-infrared spectroscopy study.

Science.gov (United States)

Sokoloff, Max D; Plegue, Melissa A; Chervin, Ronald D; Barks, John D E; Shellhaas, Renée A

2015-07-01

Near-infrared spectroscopy (NIRS) measures oxygen metabolism and is increasingly used for monitoring critically ill neonates. The implications of NIRS-recorded data in this population are poorly understood. We evaluated NIRS monitoring for neonates with seizures. In neonates monitored with video-electroencephalography, NIRS-measured cerebral regional oxygen saturation (rSO2) and systemic O2 saturation were recorded every 5 s. Mean rSO2 was extracted for 1-h blocks before, during, and after phenobarbital doses. For each electrographic seizure, mean rSO2 was extracted for a period of three times the duration of the seizure before and after the ictal pattern, as well as during the seizure. Linear mixed models were developed to assess the impact of phenobarbital administration and of seizures on rSO2 and fractional tissue oxygen extraction. For 20 neonates (estimated gestational age: 39.6 ± 1.5 wk), 61 phenobarbital doses and 40 seizures were analyzed. Cerebral rSO2 rose (P = 0.005), and fractional tissue oxygen extraction declined (P = 0.018) with increasing phenobarbital doses. rSO2 declined during seizures, compared with baseline and postictal phases (baseline 81.2 vs. ictal 77.7 vs. postictal 79.4; P = 0.004). Fractional tissue oxygen extraction was highest during seizures (P = 0.002). Cerebral oxygen metabolism decreases after phenobarbital administration and increases during seizures. These small, but clear, changes in cerebral oxygen metabolism merit assessment for potential clinical impact.

Geometrical influences on multi-pass laser forming

International Nuclear Information System (INIS)

Edwardson, S P; Abed, E; Bartkowiak, K; Dearden, G; Watkins, K G

2006-01-01

Laser forming (LF) offers the industrial promise of controlled shaping of metallic and non-metallic components for prototyping, the correction of design shape or distortion and precision adjustment applications. The potential process advantages include precise incremental adjustment, flexibility of application and no mechanical 'spring-back' effect. To date there has been a considerable amount of work carried out on two-dimensional LF, using multi-pass straight line scan strategies to produce a reasonably controlled bend angle in a number of materials, including aerospace alloys. A key area, however, where there is a limited understanding, is the variation in bend angle per pass during multi-pass LF along a single irradiation track; in particular, the decrease in bend angle per pass after many irradiations for a given set of process parameters. Understanding this is essential if the process is to be fully controlled in a manufacturing environment. The research presented in this paper highlights the current theories as to why this occurs and proposes a further reason based on the geometrical effects of the component deformation, which in turn influences the process parameters per pass. This theory is confirmed through empirical analysis of the 2D LF process

From single-shot towards general work extraction in a quantum thermodynamic framework

International Nuclear Information System (INIS)

Gemmer, Jochen; Anders, Janet

2015-01-01

This paper considers work extraction from a quantum system to a work storage system (or weight) following Horodecki and Oppenheim (2013 Nat. Commun. 4 2059). An alternative approach is here developed that relies on the comparison of subspace dimensions without a need to introduce thermo-majorization used previously. Optimal single shot work for processes where a weight transfers from (a) a single energy level to another single energy level is then re-derived. In addition we discuss the final state of the system after work extraction and show that the system typically ends in its thermal state, while there are cases where the system is only close to it. The work of formation in the single level transfer setting is also re-derived. The approach presented now allows the extension of the single shot work concept to work extraction (b) involving multiple final levels of the weight. A key conclusion here is that the single shot work for case (a) is appropriate only when a resonance of a particular energy is required. When wishing to identify ‘work extraction’ with finding the weight in a specific available energy or any higher energy a broadening of the single shot work concept is required. As a final contribution we consider transformations of the system that (c) result in general weight state transfers. Introducing a transfer-quantity allows us to formulate minimum requirements for transformations to be at all possible in a thermodynamic framework. We show that choosing the free energy difference of the weight as the transfer-quantity one recovers various single shot results including single level transitions (a), multiple final level transitions (b), and recent results on restricted sets of multi-level to multi-level weight transfers. (paper)

Detection of misery perfusion in the cerebral hemisphere with chronic unilateral major cerebral artery steno-occlusive disease using crossed cerebellar hypoperfusion: comparison of brain SPECT and PET imaging

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Yoshiyasu; Ogasawara, Kuniaki; Saito, Hideo; Takahashi, Yoshihiro; Ogasawara, Yasushi; Kobayashi, Masakazu; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Yoshida, Kenji; Beppu, Takaaki; Kubo, Yoshitaka; Fujiwara, Shunrou [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Tsushima, Eiki [Hirosaki University, Graduate School of Health Sciences, Hirosaki (Japan)

2013-10-15

In patients with unilateral internal carotid or middle cerebral artery (ICA or MCA) occlusive disease, the degree of crossed cerebellar hypoperfusion that is evident within a few months after the onset of stroke may reflect cerebral metabolic rate of oxygen in the affected cerebral hemisphere relative to that in the contralateral cerebral hemisphere. The aim of the present study was to determine whether the ratio of blood flow asymmetry in the cerebellar hemisphere to blood flow asymmetry in the cerebral hemisphere on positron emission tomography (PET) and single photon emission computed tomography (SPECT) correlates with oxygen extraction fraction (OEF) asymmetry in the cerebral hemisphere on PET in patients with chronic unilateral ICA or MCA occlusive disease and whether this blood flow ratio on SPECT detects misery perfusion in the affected cerebral hemisphere in such patients. Brain blood flow and OEF were assessed using {sup 15}O-PET and N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) SPECT, respectively. All images were anatomically standardized using SPM2. A region of interest (ROI) was automatically placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres using a three-dimensional stereotaxic ROI template, and affected-to-contralateral asymmetry in the MCA territory or contralateral-to-affected asymmetry in the cerebellar hemisphere was calculated. Sixty-three patients with reduced blood flow in the affected cerebral hemisphere on {sup 123}I-IMP SPECT were enrolled in this study. A significant correlation was observed between MCA ROI asymmetry of PET OEF and the ratio of cerebellar hemisphere asymmetry of blood flow to MCA ROI asymmetry of blood flow on PET (r = 0.381, p = 0.0019) or SPECT (r = 0.459, p = 0.0001). The correlation coefficient was higher when reanalyzed in a subgroup of 43 patients undergoing a PET study within 3 months after the last ischemic event (r = 0.541, p = 0.0001 for PET; r = 0.609, p < 0

Parametric analysis of plastic strain and force distribution in single pass metal spinning

International Nuclear Information System (INIS)

Choudhary, Shashank; Tejesh, Chiruvolu Mohan; Regalla, Srinivasa Prakash; Suresh, Kurra

2013-01-01

Metal spinning also known as spin forming is one of the sheet metal working processes by which an axis-symmetric part can be formed from a flat sheet metal blank. Parts are produced by pressing a blunt edged tool or roller on to the blank which in turn is mounted on a rotating mandrel. This paper discusses about the setting up a 3-D finite element simulation of single pass metal spinning in LS-Dyna. Four parameters were considered namely blank thickness, roller nose radius, feed ratio and mandrel speed and the variation in forces and plastic strain were analysed using the full-factorial design of experiments (DOE) method of simulation experiments. For some of these DOE runs, physical experiments on extra deep drawing (EDD) sheet metal were carried out using En31 tool on a lathe machine. Simulation results are able to predict the zone of unsafe thinning in the sheet and high forming forces that are hint to the necessity for less-expensive and semi-automated machine tools to help the household and small scale spinning workers widely prevalent in India

Parametric analysis of plastic strain and force distribution in single pass metal spinning

Science.gov (United States)

Choudhary, Shashank; Tejesh, Chiruvolu Mohan; Regalla, Srinivasa Prakash; Suresh, Kurra

2013-12-01

Metal spinning also known as spin forming is one of the sheet metal working processes by which an axis-symmetric part can be formed from a flat sheet metal blank. Parts are produced by pressing a blunt edged tool or roller on to the blank which in turn is mounted on a rotating mandrel. This paper discusses about the setting up a 3-D finite element simulation of single pass metal spinning in LS-Dyna. Four parameters were considered namely blank thickness, roller nose radius, feed ratio and mandrel speed and the variation in forces and plastic strain were analysed using the full-factorial design of experiments (DOE) method of simulation experiments. For some of these DOE runs, physical experiments on extra deep drawing (EDD) sheet metal were carried out using En31 tool on a lathe machine. Simulation results are able to predict the zone of unsafe thinning in the sheet and high forming forces that are hint to the necessity for less-expensive and semi-automated machine tools to help the household and small scale spinning workers widely prevalent in India.

Parametric analysis of plastic strain and force distribution in single pass metal spinning

Energy Technology Data Exchange (ETDEWEB)

Choudhary, Shashank, E-mail: shashankbit08@gmail.com, E-mail: mohantejesh93@gmail.com, E-mail: regalla@hyderabad.bits-pilani.ac.in, E-mail: ksuresh@hyderabad.bits-pilani.ac.in; Tejesh, Chiruvolu Mohan, E-mail: shashankbit08@gmail.com, E-mail: mohantejesh93@gmail.com, E-mail: regalla@hyderabad.bits-pilani.ac.in, E-mail: ksuresh@hyderabad.bits-pilani.ac.in; Regalla, Srinivasa Prakash, E-mail: shashankbit08@gmail.com, E-mail: mohantejesh93@gmail.com, E-mail: regalla@hyderabad.bits-pilani.ac.in, E-mail: ksuresh@hyderabad.bits-pilani.ac.in; Suresh, Kurra, E-mail: shashankbit08@gmail.com, E-mail: mohantejesh93@gmail.com, E-mail: regalla@hyderabad.bits-pilani.ac.in, E-mail: ksuresh@hyderabad.bits-pilani.ac.in [Department of Mechanical Engineering, BITS-Pilani, Hyderabad Campus, Shamirpet, Hyderabad, 500078, Andhra Pradesh (India)

2013-12-16

Metal spinning also known as spin forming is one of the sheet metal working processes by which an axis-symmetric part can be formed from a flat sheet metal blank. Parts are produced by pressing a blunt edged tool or roller on to the blank which in turn is mounted on a rotating mandrel. This paper discusses about the setting up a 3-D finite element simulation of single pass metal spinning in LS-Dyna. Four parameters were considered namely blank thickness, roller nose radius, feed ratio and mandrel speed and the variation in forces and plastic strain were analysed using the full-factorial design of experiments (DOE) method of simulation experiments. For some of these DOE runs, physical experiments on extra deep drawing (EDD) sheet metal were carried out using En31 tool on a lathe machine. Simulation results are able to predict the zone of unsafe thinning in the sheet and high forming forces that are hint to the necessity for less-expensive and semi-automated machine tools to help the household and small scale spinning workers widely prevalent in India.

Pass-transistor asynchronous sequential circuits

Science.gov (United States)

Whitaker, Sterling R.; Maki, Gary K.

1989-01-01

Design methods for asynchronous sequential pass-transistor circuits, which result in circuits that are hazard- and critical-race-free and which have added degrees of freedom for the input signals, are discussed. The design procedures are straightforward and easy to implement. Two single-transition-time state assignment methods are presented, and hardware bounds for each are established. A surprising result is that the hardware realizations for each next state variable and output variable is identical for a given flow table. Thus, a state machine with N states and M outputs can be constructed using a single layout replicated N + M times.

Aphasia following anterior cerebral artery occlusion

International Nuclear Information System (INIS)

Shimosaka, Shinichi; Waga, Shiro; Kojima, Tadashi; Shimizu, Takeo; Morikawa, Atsunori

1982-01-01

We have report two cases of aphasia that had infarcts in the distribution of the left or right anterior cerebral artery, as confirmed by computed tomography. Case 1 is a right-handed, 65-year-old man in whom computerized tomographic scanning revealed an infarction of the territory of the left anterior cerebral artery after the clipping of the anterior communicating artery aneurysm. The standard language test of aphasia (SLTA) revealed non-fluent aphasia with dysarthria, good comprehension, almost normal repetition with good articulation, and a defectiveness in writing. This syndrome was considered an instance of transcortical motor aphasia. Although three years had passed from the onset, his aphasia did not show any improvement. Case 2 is a 37-year-old man who is right-handed but who can use his left hand as well. He was admitted because of subarachnoid hemorrhage from an anterior communicating aneurysm. Because of postoperative spasm, an infarction in the distribution of the right anterior cerebral artery developed. He was totally unable to express himself vocally, but he could use written language quite well to express his ideas and had a good comprehension of spoken language. This clinical picture was considered that of an aphemia. After several weeks, his vocalization returned, but the initial output was still hypophonic. (J.P.N.)

Correlation of histological findings of single session Er:YAG skin fractional resurfacing with various passes and energies and the possible clinical implications.

Science.gov (United States)

Trelles, Mario A; Vélez, Mariano; Mordon, Serge

2008-03-01

Ablative fractional resurfacing shows promise for skin resurfacing and tightening and also to improve treatment of epidermal and dermal pigmentary disorders. This study aimed at determining any correlation between epidermal ablation and effects on the dermis when using an Er:YAG laser in ablative fractional resurfacing mode. Ten female subjects participated in the study, mean age 52 years, Skin phototypes: 1 Fitzpatrick type II; 8 type III and 1 type IV. The degree of wrinkles (Glogau scale II or III) was similar in all cases. The laser used was the Pixel Er:YAG system (Alma Lasertrade mark, Israel) which delivers the laser beam via a hand-piece equipped with a beam splitter to divide the 2,940 nm beam into various microbeams of 850 microm in diameter in an 11 mmx11 mm treatment area. Using a constant energy of 1,400 mJ/cm(2), on a test area of 4 cmx2 cm. Two, 4, 6, and 8 passes on the preauricular area of the face were evaluated immediately after treatment. In all cases, the handpiece was kept in the same position, and rotated slightly around its perpendicular axis between passes, then moved on to the next spot. Biopsies were performed and tissue samples were routinely processed and stained with hematoxylin and eosin (H&E). No patient reported any noticeable discomfort, even at 8 passes. The histological findings revealed that, independent of the degree of the wrinkles, more laser passes produced more ablative removal of the epidermis. Residual thermal damage (RTD) with 2 laser passes was not observed but with 4 and 6 passes increased thermal effects and vacuole formation in the epidermal cells were noticed. With 8 laser passes, total epidermal removal was seen together with frank RTD-related changes in the upper part of the papillary dermis. In this study, we have demonstrated that high density fractional Er:YAG laser energy in a single session with multiple passes targeted not only the skin surface with elimination of the epidermis, but could also achieve heat

Prediction of cerebral ischemia due to cerebral vasospasm in SAH using SPECT and sup 123 I-IMP with acetazolamide test

Energy Technology Data Exchange (ETDEWEB)

Nakagawara, Jyoji; Wada, Keiji; Takeda, Rihei; Usami, Takashi; Hashimoto, Ikuo; Shimazaki, Mitsuteru; Tanaka, Chiharu; Nakamura, Jun-ichi (Nakamura Memorial Hospital, Sapporo (Japan)); Suematsu, Katsumi

1989-11-01

To investigate the possibility of predicting cerebral ischemia due to cerebral vasospasm in subarachnoid hemorrhage (SAH), serial evaluation of the cerebral vasodilatory capacity by the acetazolamide test was conducted, using single photon emission computed tomography (SPECT) and N-isopropyl {sup 123}I-p-iodoamphetamine (IMP), in 17 patients with cerebral vasospasm following early surgery for ruptured aneurysms. The degree of vasospasm measured on the angiograms was classified into the following three types; mild degree (25%>stenosis), moderate degree (25{approx}50% stenosis), and severe degree(50%cerebral vasodilatory capacity was preserved at the normal level during the period of vasospasm. In eight patients with asymptomatic vasospasm (moderate degree), a transient limitation of cerebral vasodiratory capacity was observed between the 6th and 16th day after a rupture of the cerebral aneurysm. In five patients with symptomatic vasospasm resulting in reversible ischemia, a marked limitation of cerebral vasodilatory capacity was noted between the 7th and 15th day, and a delayed recovery of cerebral vasodilatory capacity was observed. This reversibility of cerebral vasodilatory capacity in patients with cerebral vasospasm suggests that a local decrease of purfusion pressure due to cerebral vasospasm causes compensatory vasodilation of intraparenchymal arteries and the vasodilatory reaction to acetazolamide was limited until the release of the cerebral vasospasm. Therefore, assessment of cerebral vasodilatory capacity in SAH by the acetazolamide test might predict the appearance and continuation of potential ischemia of the brain caused by the reduction of perfusion pressure due to cerebral vasospasm. (J.P.N.).

Does preoperative measurement of cerebral blood flow with acetazolamide challenge in addition to preoperative measurement of cerebral blood flow at the resting state increase the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy? Results from 500 cases with brain perfusion single-photon emission computed tomography study.

Science.gov (United States)

Oshida, Sotaro; Ogasawara, Kuniaki; Saura, Hiroaki; Yoshida, Koji; Fujiwara, Shunro; Kojima, Daigo; Kobayashi, Masakazu; Yoshida, Kenji; Kubo, Yoshitaka; Ogawa, Akira

2015-01-01

The purpose of the present study was to determine whether preoperative measurement of cerebral blood flow (CBF) with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy (CEA). CBF at the resting state and cerebrovascular reactivity (CVR) to acetazolamide were quantitatively assessed using N-isopropyl-p-[(123)I]-iodoamphetamine (IMP)-autoradiography method with single-photon emission computed tomography (SPECT) before CEA in 500 patients with ipsilateral internal carotid artery stenosis (≥ 70%). CBF measurement using (123)I-IMP SPECT was also performed immediately and 3 days after CEA. A region of interest (ROI) was automatically placed in the middle cerebral artery territory in the affected cerebral hemisphere using a three-dimensional stereotactic ROI template. Preoperative decreases in CBF at the resting state [95% confidence intervals (CIs), 0.855 to 0.967; P = 0.0023] and preoperative decreases in CVR to acetazolamide (95% CIs, 0.844 to 0.912; P state (difference between areas, 0.173; P state (P state increases the predictive accuracy of the development of post-CEA hyperperfusion.

Cerebral microcirculation during experimental normovolaemic anaemia

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Judith eBellapart

2016-02-01

Full Text Available Anaemia is accepted amongst critically ill patients as an alternative to elective blood transfusion. This practice has been extrapolated to head injury patients with only one study comparing the effects of mild anaemia on neurological outcome. There are no studies quantifying microcirculation during anaemia. Experimental studies suggest that anaemia leads to cerebral hypoxia and increased rates of infarction, but the lack of clinical equipoise when testing the cerebral effects of transfusion amongst critically injured patients, supports the need of experimental studies. The aim of this study was to quantify cerebral microcirculation and the potential presence of axonal damage in an experimental model exposed to normovolaemic anaemia, with the intention of describing possible limitations within management practices in critically ill patients. Under non-recovered anaesthesia, six Merino sheep were instrumented using an intracardiac transeptal catheter to inject coded microspheres into the left atrium to ensure systemic and non-chaotic distribution. Cytometric analyses quantified cerebral microcirculation at specific regions of the brain. Amyloid precursor protein staining was used as an indicator of axonal damage. Animals were exposed to normovolaemic anaemia by blood extractions from the indwelling arterial catheter with simultaneous fluid replacement through a venous central catheter. Simultaneous data recording from cerebral tissue oxygenation, intracranial pressure and cardiac output was monitored. A regression model was used to examine the effects of anaemia on microcirculation with a mixed model to control for repeated measures. Homogeneous and normal cerebral microcirculation with no evidence of axonal damage was present in all cerebral regions, with no temporal variability, concluding that acute normovolaemic anaemia does not result in short term effects on cerebral microcirculation in the ovine brain.

Effectiveness of sugammadex for cerebral ischemia/reperfusion injury.

Science.gov (United States)

Ozbilgin, Sule; Yılmaz, Osman; Ergur, Bekir Ugur; Hancı, Volkan; Ozbal, Seda; Yurtlu, Serhan; Gunenc, Sakize Ferim; Kuvaki, Bahar; Kucuk, Burcu Ataseven; Sisman, Ali Rıza

2016-06-01

Cerebral ischemia may cause permanent brain damage and behavioral dysfunction. The efficacy and mechanisms of pharmacological treatments administered immediately after cerebral damage are not fully known. Sugammadex is a licensed medication. As other cyclodextrins have not passed the necessary phase tests, trade preparations are not available, whereas sugammadex is frequently used in clinical anesthetic practice. Previous studies have not clearly described the effects of the cyclodextrin family on cerebral ischemia/reperfusion (I/R) damage. The aim of this study was to determine whether sugammadex had a neuroprotective effect against transient global cerebral ischemia. Animals were assigned to control, sham-operated, S 16 and S 100 groups. Transient global cerebral ischemia was induced by 10-minute occlusion of the bilateral common carotid artery, followed by 24-hour reperfusion. At the end of the experiment, neurological behavior scoring was performed on the rats, followed by evaluation of histomorphological and biochemical measurements. Sugammadex 16 mg/kg and 100 mg/kg improved neurological outcome, which was associated with reductions in both histological and neurological scores. The hippocampus TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) and caspase results in the S 16 and S 100 treatment groups were significantly lower than those of the I/R group. Neurological scores in the treated groups were significantly higher than those of the I/R group. The study showed that treatment with 16 mg/kg and 100 mg/kg sugammadex had a neuroprotective effect in a transient global cerebral I/R rat model. However, 100 mg/kg sugammadex was more neuroprotective in rats. Copyright © 2016. Published by Elsevier Taiwan.

Effectiveness of sugammadex for cerebral ischemia/reperfusion injury

Directory of Open Access Journals (Sweden)

Sule Ozbilgin

2016-06-01

Full Text Available Cerebral ischemia may cause permanent brain damage and behavioral dysfunction. The efficacy and mechanisms of pharmacological treatments administered immediately after cerebral damage are not fully known. Sugammadex is a licensed medication. As other cyclodextrins have not passed the necessary phase tests, trade preparations are not available, whereas sugammadex is frequently used in clinical anesthetic practice. Previous studies have not clearly described the effects of the cyclodextrin family on cerebral ischemia/reperfusion (I/R damage. The aim of this study was to determine whether sugammadex had a neuroprotective effect against transient global cerebral ischemia. Animals were assigned to control, sham-operated, S 16 and S 100 groups. Transient global cerebral ischemia was induced by 10-minute occlusion of the bilateral common carotid artery, followed by 24-hour reperfusion. At the end of the experiment, neurological behavior scoring was performed on the rats, followed by evaluation of histomorphological and biochemical measurements. Sugammadex 16 mg/kg and 100 mg/kg improved neurological outcome, which was associated with reductions in both histological and neurological scores. The hippocampus TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling and caspase results in the S 16 and S 100 treatment groups were significantly lower than those of the I/R group. Neurological scores in the treated groups were significantly higher than those of the I/R group. The study showed that treatment with 16 mg/kg and 100 mg/kg sugammadex had a neuroprotective effect in a transient global cerebral I/R rat model. However, 100 mg/kg sugammadex was more neuroprotective in rats.

An analysis of regional cerebral blood flow in impulsive murderers using single photon emission computed tomography.

Science.gov (United States)

Amen, Daniel G; Hanks, Chris; Prunella, Jill R; Green, Aisa

2007-01-01

The authors explored differences in regional cerebral blood flow in 11 impulsive murderers and 11 healthy comparison subjects using single photon emission computed tomography. The authors assessed subjects at rest and during a computerized go/no-go concentration task. Using statistical parametric mapping software, the authors performed voxel-by-voxel t tests to assess significant differences, making family-wide error corrections for multiple comparisons. Murderers were found to have significantly lower relative rCBF during concentration, particularly in areas associated with concentration and impulse control. These results indicate that nonemotionally laden stimuli may result in frontotemporal dysregulation in people predisposed to impulsive violence.

Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

International Nuclear Information System (INIS)

Depresseux, J.C.; Franck, G.; Van Cauwenberge, H.

1987-01-01

Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple [fr

Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Depresseux, J C; Franck, G., Van Cauwenberge, H.

1987-06-18

Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple.

Evaluation of optimal scan duration and end time in cerebral CT perfusion study

International Nuclear Information System (INIS)

Hirata, Masaaki; Sugawara, Yoshifumi; Miki, Hitoshi; Mochizuki, Teruhito; Murase, Kenya

2005-01-01

The purpose of this study was to evaluate the optimal end time of scanning and the influence of varying the number of source images adopted for calculation of the parameter values in computerized tomography (CT) perfusion. Nineteen CT perfusion studies in 14 patients with cerebrovascular disease were retrospectively analyzed. CT perfusion scanning was performed using continuous scans of 1 sec/rotation x 60 sec with 5-mm-thick sections. To determine the appropriate end time of scanning, the time-density curves (TDCs) of the anterior cerebral artery (ACA), superior sagittal sinus (SSS), and basal ganglia were analyzed. The functional maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were retrospectively generated from various numbers (30, 35, 40, 45, 50, 55, and 60) of source images. Defining the values calculated from the number of source images equal to the end time of the first pass as standard values, the percentage difference between the standard values and the values generated from various numbers of sources were evaluated. The TDCs of SSS showed the latest end time of the first pass (mean, 38.6±5.2 sec; range, 32 to 48 sec). Therefore, the values calculated from the number of source images equal to the end time of the first pass of SSS were defined as standard values. Increase and decrease of the number of source images for calculation resulted in increase of the percentage difference in every parameter value. The percentage differences ranged up to 49.6% for CBF, 48.0% for CBV, and 20.0% for MTT. Scanning until the end time of the first pass of SSS is necessary and sufficient for reliable measurement. Variable scan time based on the TDC of the SSS may be of better utility than use of fixed scan time. Further, the radiation dose could be minimized in many cases by reducing the scan time. (author)

Dynamic emission tomography of regional cerebral blood flow

International Nuclear Information System (INIS)

Lassen, N.A.

1984-01-01

The author reviews three tomographic methods for measuring the regional cerebral blood flow: single photon transmission tomography; dual photon emission tomography; and single photon emission tomography. The latter technique is discussed in detail. (Auth.)

Measurements of regional cerebral blood flow (rCBF) using dynamic single-photon emission computed tomography (DSPECT): Definition of a generally acceptable normal range and follow-up checks after extracranial bypass surgery

International Nuclear Information System (INIS)

Kreisig, T.

1986-01-01

The usefulness of dynamic single-photon emission computed tomography was evaluated in 50 volunteers with unobtrusive cerebral findings, who were to provide the relevant standard values. It was found that the values measured were easily reproducible. Measurements in patients showing cerebrovascular disease that were carried out before and after extracranial bypass surgery did mostly not suggest any perceivable improvement of cerebral blood flow. In isolated cases the cerebral reserve was influenced favourably, as judged from measurements after administration of acetazolamide. (MBC) [de

Intestinal permeability of forskolin by in situ single pass perfusion in rats.

Science.gov (United States)

Liu, Zhen-Jun; Jiang, Dong-bo; Tian, Lu-Lu; Yin, Jia-Jun; Huang, Jian-Ming; Weng, Wei-Yu

2012-05-01

The intestinal permeability of forskolin was investigated using a single pass intestinal perfusion (SPIP) technique in rats. SPIP was performed in different intestinal segments (duodenum, jejunum, ileum, and colon) with three concentrations of forskolin (11.90, 29.75, and 59.90 µg/mL). The investigations of adsorption and stability were performed to ensure that the disappearance of forskolin from the perfusate was due to intestinal absorption. The results of the SPIP study indicated that forskolin could be absorbed in all segments of the intestine. The effective permeability (P (eff)) of forskolin was in the range of drugs with high intestinal permeability. The P (eff) was highest in the duodenum as compared to other intestinal segments. The decreases of P (eff) in the duodenum and ileum at the highest forskolin concentration suggested a saturable transport process. The addition of verapamil, a P-glycoprotein inhibitor, significantly enhanced the permeability of forskolin across the rat jejunum. The absorbed fraction of dissolved forskolin after oral administration in humans was estimated to be 100 % calculated from rat P (eff). In conclusion, dissolved forskolin can be absorbed readily in the intestine. The low aqueous solubility of forskolin might be a crucial factor for its poor oral bioavailability. © Georg Thieme Verlag KG Stuttgart · New York.

Sequential assessment of regional cerebral blood flow, regional cerebral blood volume, and blood-brain barrier in focal cerebral ischemia: a case report

International Nuclear Information System (INIS)

Di Piero, V.; Perani, D.; Savi, A.; Gerundini, P.; Lenzi, G.L.; Fazio, F.

1986-01-01

Regional CBF (rCBF) and regional cerebral blood volume (rCBV) were evaluated by N,N,N'-trimethyl-N'-(2)-hydroxy-3-methyl-5-[123I]iodobenzyl-1, 3-propanediamine-2 HCl- and /sup 99m/TC-labeled red blood cells, respectively, and single-photon emission computerized tomography (SPECT) in a patient with focal cerebral ischemia. Sequential transmission computerized tomography (TCT) and SPECT functional data were compared with clinical findings to monitor the pathophysiological events occurring in stroke. A lack of correlation between rCBF-rCBV distributions and blood-brain barrier (BBB) breakdown was found in the acute phase. In the face of more prolonged alteration of BBB, as seen by TCT enhancement, a rapid evolution of transient phenomena such as luxury perfusion was shown by SPECT studies. Follow-up of the patient demonstrated a correlation between the neurological recovery and a parallel relative improvement of the cerebral perfusion

Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

Science.gov (United States)

Wattanathorn, Jintanaporn; Jittiwat, Jinatta; Tongun, Terdthai; Muchimapura, Supaporn; Ingkaninan, Kornkanok

2011-01-01

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia. PMID:21197427

Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

Directory of Open Access Journals (Sweden)

Jintanaporn Wattanathorn

2011-01-01

Full Text Available Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO. Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA, superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia.

Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

Energy Technology Data Exchange (ETDEWEB)

Herold, S.

1985-03-01

Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack.

Message Passing Framework for Globally Interconnected Clusters

International Nuclear Information System (INIS)

Hafeez, M; Riaz, N; Asghar, S; Malik, U A; Rehman, A

2011-01-01

In prevailing technology trends it is apparent that the network requirements and technologies will advance in future. Therefore the need of High Performance Computing (HPC) based implementation for interconnecting clusters is comprehensible for scalability of clusters. Grid computing provides global infrastructure of interconnecting clusters consisting of dispersed computing resources over Internet. On the other hand the leading model for HPC programming is Message Passing Interface (MPI). As compared to Grid computing, MPI is better suited for solving most of the complex computational problems. MPI itself is restricted to a single cluster. It does not support message passing over the internet to use the computing resources of different clusters in an optimal way. We propose a model that provides message passing capabilities between parallel applications over the internet. The proposed model is based on Architecture for Java Universal Message Passing (A-JUMP) framework and Enterprise Service Bus (ESB) named as High Performance Computing Bus. The HPC Bus is built using ActiveMQ. HPC Bus is responsible for communication and message passing in an asynchronous manner. Asynchronous mode of communication offers an assurance for message delivery as well as a fault tolerance mechanism for message passing. The idea presented in this paper effectively utilizes wide-area intercluster networks. It also provides scheduling, dynamic resource discovery and allocation, and sub-clustering of resources for different jobs. Performance analysis and comparison study of the proposed framework with P2P-MPI are also presented in this paper.

Mouse single oral dose toxicity test of bupleuri radix aqueous extracts.

Science.gov (United States)

Kim, Kyung-Hu; Gam, Cheol-Ou; Choi, Seong-Hun; Ku, Sae-Kwang

2012-03-01

The aim of this study was to evaluate the single oral dose toxicity of Bupleuri Radix (BR) aqueous extracts, it has been traditionally used as anti-inflammatory agent, in male and female mice. BR extracts (yield = 16.52%) was administered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 14 principal organs were examined. As the results, no BR extracts treatment related mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations against 14 principal organs were detected up to 2,000 mg/kg in both female and male mice, except for soft feces and related body weight decrease detected in male mice treated with 2,000 mg/kg. Therefore, LD50 (50% lethal dose) and approximate LD of BR aqueous extracts after single oral treatment in female and male mice were considered over 2000 mg/kg, respectively. Although it was also observed that the possibilities of digestive disorders, like soft feces when administered over 2,000 mg/kg of BR extracts in the present study, these possibilities of digestive disorders can be disregard in clinical use because they are transient in the highest dosages male only.

Hemodynamic disturbances in cerebral ischemia; Correlation between positron emission tomographic and angiographic findings

Energy Technology Data Exchange (ETDEWEB)

Tenjin, Hiroshi; Ueda, Satoshi; Mizukawa, Norihiko; Imahori, Yoshio; Hino, Akihiko; Ohmori, Yoshio [Kyoto Prefectural Univ. of Medicine (Japan); Nakahashi, Hisamitsu

1993-04-01

Proper treatment of ischemic stroke requires better understanding of cerebral hemodynamic changes. The hemodynamic changes associated with ischemia were measured using positron emission tomography and related to angiographic findings in the subacute and chronic stages of 17 ischemia patients who showed symptoms of main trunk stenosis of the internal carotid artery system. The hemodynamic factors, cerebral blood flow, cerebral blood volume, cerebral metabolic rate for oxygen, oxygen extraction fraction, and flow/volume ratio, were measured in regions of interest determined from the angiographic stenosis (over 50%) and compared in each stage. The cerebral blood flow and flow/volume ratio in the territory downstream of the main trunk stenosis and cerebral metabolic rate for oxygen in the whole cortex were decreased in the subacute stage. In the chronic stage, cerebral blood flow and flow/volume ratio decreased mainly in borderzone areas. (author).

Diabetic patients have abnormal cerebral autoregulation during cardiopulmonary bypass

International Nuclear Information System (INIS)

Croughwell, N.; Lyth, M.; Quill, T.J.; Newman, M.; Greeley, W.J.; Smith, L.R.; Reves, J.G.

1990-01-01

We tested the hypothesis that insulin-dependent diabetic patients with coronary artery bypass graft surgery experience altered coupling of cerebral blood flow and oxygen consumption. In a study of 23 patients (11 diabetics and 12 age-matched controls), cerebral blood flow was measured using 133Xe clearance during nonpulsatile, alpha-stat blood gas managed cardiopulmonary bypass at the conditions of hypothermia and normothermia. In diabetic patients, the cerebral blood flow at 26.6 +/- 2.42 degrees C was 25.3 +/- 14.34 ml/100 g/min and at 36.9 +/- 0.58 degrees C it was 27.3 +/- 7.40 ml/100 g/min (p = NS). The control patients increased cerebral blood flow from 20.7 +/- 6.78 ml/100 g/min at 28.4 +/- 2.81 degrees C to 37.6 +/- 8.81 ml/100 g/min at 36.5 +/- 0.45 degrees C (p less than or equal to 0.005). The oxygen consumption was calculated from jugular bulb effluent and increased from hypothermic values of 0.52 +/- 0.20 ml/100 g/min in diabetics to 1.26 +/- 0.28 ml/100 g/min (p = 0.001) at normothermia and rose from 0.60 +/- 0.27 to 1.49 +/- 0.35 ml/100 g/min (p = 0.0005) in the controls. Thus, despite temperature-mediated changes in oxygen consumption, diabetic patients did not increase cerebral blood flow as metabolism increased. Arteriovenous oxygen saturation gradients and oxygen extraction across the brain were calculated from arterial and jugular bulb blood samples. The increase in arteriovenous oxygen difference between temperature conditions in diabetic patients and controls was significantly different (p = 0.01). These data reveal that diabetic patients lose cerebral autoregulation during cardiopulmonary bypass and compensate for an imbalance in adequate oxygen delivery by increasing oxygen extraction

Cerebral blood flow measurement in patients with impaired consciousness: usefulness of 99mTc-HMPAO single-photon emission tomography in clinical practice

International Nuclear Information System (INIS)

Chang Chia-Cheng; Kuwana, Nobumasa; Noji, Masato; Tanabe, Yutaka; Koike, Y.; Ikegami, Tadashi

1998-01-01

The relationship between impairment of consciousness and quantitative cerebral blood flow (CBF) was investigated. The mean CBF of the whole brain was measured by the Patlak-plot method using technetium-99m hexamethylpropylene amine oxime single-photon emission tomography ( 99m Tc-HMPAO SPET) in patients with the following diseases: cerebral infarction, intraparenchymal haemorrhage, subarachnoid haemorrhage, brain tumour and cerebral contusion. The clinical symptoms were evaluated according to the severity of impaired consciousness, aphasia and dementia. Four hundred and eighty-five CBF measurements were performed. Patients with alert consciousness showed an age-related decline in mean CBF. Patients with aphasia showed a significant reduction in mean CBF compared with those without aphasia. Impaired consciousness was proportional to reduction in mean CBF regardless of types of pathology, and the size of lesion did not influence the mean CBF. Patients with dementia showed a significant reduction in mean CBF proportional to the severity of dementia. The quantitative measurement of CBF using 99m Tc-HMPAO SPET is reliable in clinical evaluations. (orig.)

Dynamic change in cerebral microcirculation and focal cerebral metabolism in experimental subarachnoid hemorrhage in rabbits.

Science.gov (United States)

Song, Jin-Ning; Chen, Hu; Zhang, Ming; Zhao, Yong-Lin; Ma, Xu-Dong

2013-03-01

Regional cerebral blood flow (rCBF) in the cerebral metabolism and energy metabolism measurements can be used to assess blood flow of brain cells and to detect cell activity. Changes of rCBF in the cerebral microcirculation and energy metabolism were determined in an experimental model of subarachnoid hemorrhage (SAH) model in 56 large-eared Japanese rabbits about 12 to 16-month old. Laser Doppler flowmetry was used to detect the blood supply to brain cells. Internal carotid artery and vein blood samples were used for duplicate blood gas analysis to assess the energy metabolism of brain cells. Cerebral blood flow (CBF) was detected by single photon emission computed tomography (SPECT) perfusion imaging using Tc-99m ethyl cysteinate dimer (Tc-99m ECD) as an imaging reagent. The percentage of injected dose per gram of brain tissue was calculated and analyzed. There were positive correlations between the percentage of radionuclide injected per gram of brain tissue and rCBF supply and cerebral metabolic rate for oxygen (P brain cells after SAH, and also found that deterioration of energy metabolism of brain cells played a significant role in the development of SAH. There are matched reductions in CBF and metabolism. Thus, SPECT imaging could be used as a noninvasive method to detect CBF.

Simple extraction-solvothermal synthesis of single-crystalline silver microplates

Energy Technology Data Exchange (ETDEWEB)

You, Ting; Sun, Sixiu; Song, Xinyu; Xu, Shuling [Department of Chemistry and Chemical Engineering, Shandong University (China)

2009-08-15

Single-crystalline silver microplates, with average edge length of about 1.5{mu}m and thickness of 100 nm, have been synthesized by a simple extraction-solvothermal method. Samples were characterized in detail by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and High-resolution transmission electron microscopy (HRTEM) technologies. Extractant primary amine N1923 can also act as reducing agent. It has been found that microstructure of the silver can be controlled by the n-octanol during the solvothermal treatment. Based on a series of experimental analysis, the possible formation mechanism of these microplates was discussed briefly. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

A model of the instantaneous pressure-velocity relationships of the neonatal cerebral circulation.

Science.gov (United States)

Panerai, R B; Coughtrey, H; Rennie, J M; Evans, D H

1993-11-01

The instantaneous relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), measured with Doppler ultrasound in the anterior cerebral artery, is represented by a vascular waterfall model comprising vascular resistance, compliance, and critical closing pressure. One min recordings obtained from 61 low birth weight newborns were fitted to the model using a least-squares procedures with correction for the time delay between the BP and CBFV signals. A sensitivity analysis was performed to study the effects of low-pass filtering (LPF), cutoff frequency, and noise on the estimated parameters of the model. Results indicate excellent fitting of the model (F-test, p model parameters have a mean correlation coefficient of 0.94 with the measured flow velocity tracing (N = 232 epochs). The model developed can be useful for interpreting clinical findings and as a framework for research into cerebral autoregulation.

Clinical and pathological study on 10 cases of cerebral lobe hemorrhage related with cerebral amyloid angiopathy

Directory of Open Access Journals (Sweden)

Xiao-qi LI

2015-07-01

Full Text Available Objective　To summarize the clinical data and pathological features of 10 cases of cerebral lobar hemorrhage related with cerebral amyloid angiopathy (CAA diagnosed pathologically, thereby to improve the knowledge and diagnosis of the disease. Methods　The clinical data of 10 cases of cerebral lobar hemorrhage related with CAA, collected in the General Hospital of Shenyang Command from 1983 up to now, were retrospectively analyzed, and the clinical and neuropathological features of these cases were summarized. Results　Of the 10 patients, 2 suffered from single lobar hemorrhage and 8 multiple lobar hemorrhage, all of them were confirmed pathologically to have ruptured into the subarachnoid space. Pathological examination revealed microaneurysm in 2 cases, "double barrel" change in 4 cases, multiple arteriolar clusters in 5 cases, obliterative onion-liked intima change in 4 cases, and fibrinoid necrosis of vessel wall in 7 cases. In addition, neurofibrillary tangles were found in 8 cases, and senile plaque was observed in 5 cases. Conclusions　Cerebral lobar hemorrhage related with CAA is mainly located in the parietal, temporal and occipital lobes, readily breaking into the subarachnoid space, and it is often multiple and recurrent. The CAA associated microvasculopathy was found frequently in the autopsy sample of CAA related cerebral lobar hemorrhage, and it may contribute to the pathogenesis of cerebral hemorrhage. DOI: 10.11855/j.issn.0577-7402.2015.07.04

Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

International Nuclear Information System (INIS)

Kitamura, Shin; Ujike, Takashi; Kuroki, Soemu; Sakamoto, Shizuki; Soeda, Toshiyuki; Terashi, Akiro; Iio, Masaaki.

1988-01-01

The purpose of this study was to determine functional changes in the cerebral cortex and basal ganglia in Parkinson's disease (PD). Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO 2 ) were determined using 0-15 positron emission tomography in 10 PD patients and five age-matched healthy volunteers. There was a tendency among PD patients towards a decreased CBF and CMRO 2 in the cerebral cortex and basal ganglia. These values were significantly lower in the frontal cortex in the PD group than the control group. There was no difference in OEF between the groups. A more decreased cerebral oxygen metabolism was observed in patients staged as severer on the scale of Hoehn and Yahr. There was no correlation between cerebral oxygen metabolism and tremor, rigidity, or bradykinesis. A decreased cerebral oxygen metabolism was associated with mental disorders, such as depression, hallucination, and dementia. These results may provide an important clue for the understanding of mesocortical dopaminergic pathway and the relationship between PD and dementia. (N.K.)

Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

Energy Technology Data Exchange (ETDEWEB)

Kitamura, Shin; Ujike, Takashi; Kuroki, Soemu; Sakamoto, Shizuki; Soeda, Toshiyuki; Terashi, Akiro; Iio, Masaaki

1988-10-01

The purpose of this study was to determine functional changes in the cerebral cortex and basal ganglia in Parkinson's disease (PD). Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO/sub 2/) were determined using 0-15 positron emission tomography in 10 PD patients and five age-matched healthy volunteers. There was a tendency among PD patients towards a decreased CBF and CMRO/sub 2/ in the cerebral cortex and basal ganglia. These values were significantly lower in the frontal cortex in the PD group than the control group. There was no difference in OEF between the groups. A more decreased cerebral oxygen metabolism was observed in patients staged as severer on the scale of Hoehn and Yahr. There was no correlation between cerebral oxygen metabolism and tremor, rigidity, or bradykinesis. A decreased cerebral oxygen metabolism was associated with mental disorders, such as depression, hallucination, and dementia. These results may provide an important clue for the understanding of mesocortical dopaminergic pathway and the relationship between PD and dementia. (N.K.).

Herpes Zoster oftálmico e posterior acidente vascular cerebral: relato de caso

Directory of Open Access Journals (Sweden)

Carlos A. M. Guerreiro

1984-12-01

Full Text Available Um caso de acidente vascular cerebral (AVC 14 semanas após a instalação de herpes zoster oftálmico (HZO é apresentado. A tomografia computadorizada craniana documentou comprometimento em território de artéria cerebral média ipsilateral ao HZO. O diagnóstico de probabilidade é o de arterite por herpes zoster com posterior trombose. Os autores reviram a literatura e enfatizam o longo intervalo entre o HZO e a instalação da hemiplegia. Citam as novas drogas antivirais que tornam esta causa de AVC potencialmente passível de ser prevenida.

Storytelling: Enhancing Vocabularies For Cerebral Palsy Students

OpenAIRE

Aprilina, Raita Gina

2015-01-01

This paper reported on a study concerned with teaching vocabulary using storytelling technique in one of SLBs in Bandung. This study aimed to find out the cerebral palsy students' ability in English vocabulary before and after the treatment, and to find out whether storytelling significantly improved English vocabulary of students with cerebral palsy. This study used an experimental method with single subject research with A-B-A design which involved two participants. This study revealed that...

Applicability of near-infrared spectroscopy to measure cerebral autoregulation noninvasively in neonates: a validation study in piglets

DEFF Research Database (Denmark)

Holst Hahn, Gitte; Heiring, Christian; Pryds, Ole

2011-01-01

Impaired cerebral autoregulation (CA) is common and is associated with brain damage in sick neonates. Frequency analysis using spontaneous changes in arterial blood pressure (ABP) and cerebral near-infrared spectroscopy (NIRS) has been used to measure CA in several clinical studies. Coherence...... of the NIRS and ABP signals (i.e. correlation in the frequency domain) detects impairment of CA, whereas gain (i.e. magnitude of ABP variability passing from systemic to cerebral circulation) estimates the degree of this impairment. So far, however, this method has not been validated. In 12 newborn piglets......, we compared NIRS-derived measures of CA with a conventional measure of CA: cerebral blood flow was measured by laser Doppler flowmetry, and changes in ABP were induced by inflating a thoracic aorta balloon. CA capacity was calculated as %¿CVR/%¿ABP (i.e. percentage of full autoregulatory capacity...

Applicability of near-infrared spectroscopy to measure cerebral autoregulation noninvasively in neonates: a validation study in piglets

DEFF Research Database (Denmark)

Holst Hahn, Gitte; Heiring, Christian; Pryds, Ole

2011-01-01

Impaired cerebral autoregulation (CA) is common and is associated with brain damage in sick neonates. Frequency analysis using spontaneous changes in arterial blood pressure (ABP) and cerebral near-infrared spectroscopy (NIRS) has been used to measure CA in several clinical studies. Coherence...... of the NIRS and ABP signals (i.e. correlation in the frequency domain) detects impairment of CA, whereas gain (i.e. magnitude of ABP variability passing from systemic to cerebral circulation) estimates the degree of this impairment. So far, however, this method has not been validated. In 12 newborn piglets......, we compared NIRS-derived measures of CA with a conventional measure of CA: cerebral blood flow was measured by laser Doppler flowmetry, and changes in ABP were induced by inflating a thoracic aorta balloon. CA capacity was calculated as %ΔCVR/%ΔABP (i.e. percentage of full autoregulatory capacity...

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice

International Nuclear Information System (INIS)

Evans, Eleanor; Sawiak, Stephen J.; Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T.

2014-01-01

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time–activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration–time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18 F-FDG respectively to ascertain the technique′s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies

Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

Energy Technology Data Exchange (ETDEWEB)

Clanet, M

1987-06-18

Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO/sub 2/), oxygen extraction (EO/sub 2/) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO/sub 2/ and often a decrease in CMRO/sub 2/, whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO/sub 2/, EO/sub 2/ and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis.

Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

International Nuclear Information System (INIS)

Clanet, M.

1987-01-01

Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO 2 ), oxygen extraction (EO 2 ) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO 2 and often a decrease in CMRO 2 , whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO 2 , EO 2 and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis [fr

Comparison of sequential and single extraction in order to estimate environmental impact of metals from fly ash

Directory of Open Access Journals (Sweden)

Tasić Aleksandra M.

2016-01-01

Full Text Available The aim of this paper was to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction procedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As, Be in fly ash extracts were measured by Inductively Coupled Plasma-Atomic Emission Spectrometry. Single-agent extractions of metals were conducted during sonication times of 10, 20, 30, 40 and 50 min. Single-agent extraction with deionized water was also undertaken by exposing samples to microwave radiation at the temperature of 50°C. The sequential extraction was undertaken according to the BCR procedure which was modified and applied to study the partitioning of metals in coal fly ash. The microwave-assisted sequential extraction was performed at different extraction temperatures: 50, 100 and 150°C. The partitioning of metals between the individual fractions was investigated and discussed. The efficiency of the extraction process for each step was examined. In addition, the results of the microwave-assisted sequential extraction are compared to the results obtained by standard ASTM method. The mobility of most elements contained in fly ash is markedly pH sensitive. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. 176006 i br. III43009

The Single Pass RF Driver: Final beam compression

Energy Technology Data Exchange (ETDEWEB)

Burke, Robert, E-mail: rjburke@fusionpowercorporation.com

2014-01-01

The Single Pass RF Driver (SPRFD) compacts the beam from the linac without storage rings by manipulations that take advantage of the multiplicity of isotopes (16), the preserved µbunch structure, and increased total linac current. Magnetic switches on a first set of delay lines rearrange the internal structure of the various isotopic beams. A second set of delay lines sets the relative timing of the 16 isotopic beam sections so they will telescope at the pellet, in one of multiple fusion chambers, e.g. 10. Shortening each isotopic beam section uses preservation of the µbunch structure up to the final ∼2 km drift before final focus. Just before the final drift, differential acceleration of the µbunches in each isotopic beam section (128 total) launches an axial collapse, referred to as the “Slick”. The µbunches interpenetrate as their centers of mass move toward each other and individual µbunches lengthen due to their momentum spread. In longitudinal phase space they slide over one another as they lengthen in time and slim down in instantaneous energy spread. The permissible amount of µbunch lengthening is set by the design pulse shape at the pellet, which varies for different groups of isotopes. In narrow bands of ranges according to the role for each isotope group in the pellet, the ranges extend from 1 to 10 g/cm{sup 2} to drive the cylinder barrel and thin hemispherical end caps, to heat the ∼0.5 g/cm{sup 2}ρR fast ignition zone, and to improve the quasi-sphericity of the compression of the fast ignition zones at the pellet's ends. Because the µbunch–µbunch momentum differences are correlated, time-ramped beamline transport elements close after the differential accelerator are used to correct the associated shifts of focal point. Beam neutralization is needed after the differential acceleration until adjacent bunches begin to overlap. Concurrent collapse of each isotope and telescoping of the 16 isotopes cause the current in each beamline

The Single Pass RF Driver: Final beam compression

International Nuclear Information System (INIS)

Burke, Robert

2014-01-01

The Single Pass RF Driver (SPRFD) compacts the beam from the linac without storage rings by manipulations that take advantage of the multiplicity of isotopes (16), the preserved µbunch structure, and increased total linac current. Magnetic switches on a first set of delay lines rearrange the internal structure of the various isotopic beams. A second set of delay lines sets the relative timing of the 16 isotopic beam sections so they will telescope at the pellet, in one of multiple fusion chambers, e.g. 10. Shortening each isotopic beam section uses preservation of the µbunch structure up to the final ∼2 km drift before final focus. Just before the final drift, differential acceleration of the µbunches in each isotopic beam section (128 total) launches an axial collapse, referred to as the “Slick”. The µbunches interpenetrate as their centers of mass move toward each other and individual µbunches lengthen due to their momentum spread. In longitudinal phase space they slide over one another as they lengthen in time and slim down in instantaneous energy spread. The permissible amount of µbunch lengthening is set by the design pulse shape at the pellet, which varies for different groups of isotopes. In narrow bands of ranges according to the role for each isotope group in the pellet, the ranges extend from 1 to 10 g/cm 2 to drive the cylinder barrel and thin hemispherical end caps, to heat the ∼0.5 g/cm 2 ρR fast ignition zone, and to improve the quasi-sphericity of the compression of the fast ignition zones at the pellet's ends. Because the µbunch–µbunch momentum differences are correlated, time-ramped beamline transport elements close after the differential accelerator are used to correct the associated shifts of focal point. Beam neutralization is needed after the differential acceleration until adjacent bunches begin to overlap. Concurrent collapse of each isotope and telescoping of the 16 isotopes cause the current in each beamline to rise

Cerebral blood flow measurement in patients with impaired consciousness: usefulness of {sup 99m}Tc-HMPAO single-photon emission tomography in clinical practice

Energy Technology Data Exchange (ETDEWEB)

Chang Chia-Cheng; Kuwana, Nobumasa; Noji, Masato; Tanabe, Yutaka; Koike, Y. [Department of Neurosurgery, Yokohama Minami Kyosai Hospital, Yokohama (Japan); Ikegami, Tadashi [Department of Radiology, Yokohama Minami Kyosai Hospital, Yokohama (Japan)

1998-09-01

The relationship between impairment of consciousness and quantitative cerebral blood flow (CBF) was investigated. The mean CBF of the whole brain was measured by the Patlak-plot method using technetium-99m hexamethylpropylene amine oxime single-photon emission tomography ({sup 99m}Tc-HMPAO SPET) in patients with the following diseases: cerebral infarction, intraparenchymal haemorrhage, subarachnoid haemorrhage, brain tumour and cerebral contusion. The clinical symptoms were evaluated according to the severity of impaired consciousness, aphasia and dementia. Four hundred and eighty-five CBF measurements were performed. Patients with alert consciousness showed an age-related decline in mean CBF. Patients with aphasia showed a significant reduction in mean CBF compared with those without aphasia. Impaired consciousness was proportional to reduction in mean CBF regardless of types of pathology, and the size of lesion did not influence the mean CBF. Patients with dementia showed a significant reduction in mean CBF proportional to the severity of dementia. The quantitative measurement of CBF using {sup 99m}Tc-HMPAO SPET is reliable in clinical evaluations. (orig.) With 3 tabs., 10 refs.

A Case Associated with Comorbidities Among Cerebral Infarction, Idiopathic Thrombocytopenic Purpura, and Triple X Syndrome

Directory of Open Access Journals (Sweden)

Hanjun Kim

2014-06-01

Full Text Available A 46-year-old female presented to the emergency room due to the chief complaint of left-sided weakness. By imaging study, she was diagnosed with cerebral infarction. Thrombolytic and antiplatelet agents were not considered due to the “golden hour” for treatment having passed and a low platelet count. The peripheral blood smear, bone marrow biopsy, and aspirate findings were consistent with immune thrombocytopenic purpura. The chromosome analysis revealed the 47,XXX karyotype. To the best of our knowledge, this is the first case report associated with the comorbidities of cerebral infarction, idiopathic thrombocytopenic purpura, and triple X syndrome.

Mechanisms of Acupuncture Therapy for Cerebral Ischemia: an Evidence-Based Review of Clinical and Animal Studies on Cerebral Ischemia.

Science.gov (United States)

Zhu, Wen; Ye, Yang; Liu, Yi; Wang, Xue-Rui; Shi, Guang-Xia; Zhang, Shuai; Liu, Cun-Zhi

2017-12-01

Ischemic stroke is a major cause of mortality and disability worldwide. As a part of Traditional Chinese Medicine (TCM), acupuncture has been shown to be effective in promoting recovery after stroke. In this article, we review the clinical and experimental studies that demonstrated the mechanisms of acupuncture treatment for cerebral ischemia. Clinical studies indicated that acupuncture activated relevant brain regions, modulated cerebral blood flow and related molecules in stroke patients. Evidence from laboratory indicated that acupuncture regulates cerebral blood flow and metabolism after the interrupt of blood supply. Acupuncture regulates multiple molecules and signaling pathways that lead to excitoxicity, oxidative stress, inflammation, neurons death and survival. Acupuncture also promotes neurogenesis, angiogenesis as well as neuroplasticity after ischemic damage. The evidence provided from clinical and laboratory suggests that acupuncture induces multi-level regulation via complex mechanisms and a single factor may not be enough to explain the beneficial effects against cerebral ischemia.

Disparity in regional cerebral blood flow during electrically induced seizure

DEFF Research Database (Denmark)

Sestoft, D; Meden, P; Hemmingsen, R

1993-01-01

This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized on electroencepha......This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized...... electroencephalography-verified generalized seizures....

Microsurgery Simulator of Cerebral Aneurysm Clipping with Interactive Cerebral Deformation Featuring a Virtual Arachnoid.

Science.gov (United States)

Shono, Naoyuki; Kin, Taichi; Nomura, Seiji; Miyawaki, Satoru; Saito, Toki; Imai, Hideaki; Nakatomi, Hirofumi; Oyama, Hiroshi; Saito, Nobuhito

2018-05-01

A virtual reality simulator for aneurysmal clipping surgery is an attractive research target for neurosurgeons. Brain deformation is one of the most important functionalities necessary for an accurate clipping simulator and is vastly affected by the status of the supporting tissue, such as the arachnoid membrane. However, no virtual reality simulator implementing the supporting tissue of the brain has yet been developed. To develop a virtual reality clipping simulator possessing interactive brain deforming capability closely dependent on arachnoid dissection and apply it to clinical cases. Three-dimensional computer graphics models of cerebral tissue and surrounding structures were extracted from medical images. We developed a new method for modifiable cerebral tissue complex deformation by incorporating a nonmedical image-derived virtual arachnoid/trabecula in a process called multitissue integrated interactive deformation (MTIID). MTIID made it possible for cerebral tissue complexes to selectively deform at the site of dissection. Simulations for 8 cases of actual clipping surgery were performed before surgery and evaluated for their usefulness in surgical approach planning. Preoperatively, each operative field was precisely reproduced and visualized with the virtual brain retraction defined by users. The clear visualization of the optimal approach to treating the aneurysm via an appropriate arachnoid incision was possible with MTIID. A virtual clipping simulator mainly focusing on supporting tissues and less on physical properties seemed to be useful in the surgical simulation of cerebral aneurysm clipping. To our knowledge, this article is the first to report brain deformation based on supporting tissues.

Applications of cerebral SPECT

Energy Technology Data Exchange (ETDEWEB)

McArthur, C., E-mail: claire.mcarthur@nhs.net [Department of Neuroradiology, Institute of Neurological Sciences, Glasgow (United Kingdom); Jampana, R.; Patterson, J.; Hadley, D. [Department of Neuroradiology, Institute of Neurological Sciences, Glasgow (United Kingdom)

2011-07-15

Single-photon emission computed tomography (SPECT) can provide three-dimensional functional images of the brain following the injection of one of a series of radiopharmaceuticals that crosses the blood-brain barrier and distributes according to cerebral perfusion, neurotransmitter, or cell density. Applications include differentiating between the dementias, evaluating cerebrovascular disease, preoperative localization of epileptogenic foci, diagnosing movement disorders, and evaluation of intracerebral tumours, while also proving a useful research tool. Unlike positronemission tomography (PET), SPECT imaging is widely available and can be performed in any department that has access to a rotating gamma camera. The purpose of this review is to demonstrate the utility of cerebral SPECT and increase awareness of its role in the investigation of neurological and psychiatric disorders.

Cerebral asymmetries: complementary and independent processes.

Directory of Open Access Journals (Sweden)

Gjurgjica Badzakova-Trajkov

Full Text Available Most people are right-handed and left-cerebrally dominant for speech, leading historically to the general notion of left-hemispheric dominance, and more recently to genetic models proposing a single lateralizing gene. This hypothetical gene can account for higher incidence of right-handers in those with left cerebral dominance for speech. It remains unclear how this dominance relates to the right-cerebral dominance for some nonverbal functions such as spatial or emotional processing. Here we use functional magnetic resonance imaging with a sample of 155 subjects to measure asymmetrical activation induced by speech production in the frontal lobes, by face processing in the temporal lobes, and by spatial processing in the parietal lobes. Left-frontal, right-temporal, and right-parietal dominance were all intercorrelated, suggesting that right-cerebral biases may be at least in part complementary to the left-hemispheric dominance for language. However, handedness and parietal asymmetry for spatial processing were uncorrelated, implying independent lateralizing processes, one producing a leftward bias most closely associated with handedness, and the other a rightward bias most closely associated with spatial attention.

Double-Sided Single-Pass Submerged Arc Welding for 2205 Duplex Stainless Steel

Science.gov (United States)

Luo, Jian; Yuan, Yi; Wang, Xiaoming; Yao, Zongxiang

2013-09-01

The duplex stainless steel (DSS), which combines the characteristics of ferritic steel and austenitic steel, is used widely. The submerged arc welding (SAW) method is usually applied to join thick plates of DSS. However, an effective welding procedure is needed in order to obtain ideal DSS welds with an appropriate proportion of ferrite (δ) and austenite (γ) in the weld zone, particularly in the melted zone and heat-affected zone. This study evaluated the effectiveness of a high efficiency double-sided single-pass (DSSP) SAW joining method for thick DSS plates. The effectiveness of the converse welding procedure, characterizations of weld zone, and mechanical properties of welded joint are analyzed. The results show an increasing appearance and continuous distribution feature of the σ phase in the fusion zone of the leading welded seam. The converse welding procedure promotes the σ phase to precipitate in the fusion zone of leading welded side. The microhardness appears to significantly increase in the center of leading welded side. Ductile fracture mode is observed in the weld zone. A mixture fracture feature appears with a shear lip and tears in the fusion zone near the fusion line. The ductility, plasticity, and microhardness of the joints have a significant relationship with σ phase and heat treatment effect influenced by the converse welding step. An available heat input controlling technology of the DSSP formation method is discussed for SAW of thick DSS plates.

MRI diagnosis of the cerebral schistosomiasis

International Nuclear Information System (INIS)

Liu Hanqiu; Chen Yuanjun

2002-01-01

Objective: To discuss MRI appearance of the cerebral schistosomiasis and its clinical value through analyzing the MRI features and post-surgery pathological findings. Methods: MRI features of the cerebral schistosomiasis in 16, pathologically (n = 6) or clinically (n = 10) proved cases were analyzed retrospectively, and compared with the post-surgery pathological findings in 6 cases. Results: Single masses were found in 11 cases (11/16), and multiple masses in 5 eases (5/16), amounting to 23 masses . fifteen masses (15/23) were located in right cerebral hemisphere, including frontal lobe (n = 2), frontoparietal lobe (n = 5) , and occipitoparietal lobe (n 8), while 8 masses (8/23) in left cerebral hemisphere, including frontal lobe (n = 1), frontoparietal lobe (n = 3), and occipitoparietal lobe (n = 4). The nodular masses were isointense with the gray mass like 'island', and 12 cases (12/16) show the 'gigantic hand' form of edema around them. After IV administration of Gd-DTPA, 15 cases (15/16) revealed multiple closely spaced, intensely enhancing modules, 1-3 mm in diameter, distributed throughout the mass. Seven cases misdiagnosed by CT were revised by MRl. Conclusion: The MRI appearance of the cerebral schistosomiasis is characteristic, and MRI is the most valuable tool to diagnose it without injury

Statistical image analysis of cerebral blood flow in moyamoya disease

International Nuclear Information System (INIS)

Yamada, Masaru; Yuzawa, Izumi; Suzuki, Sachio; Kurata, Akira; Fujii, Kiyotaka; Asano, Yuji

2007-01-01

The Summary of this study was to investigate pathophysiology of moyamoya disease, we analyzed brain single photon emission tomography (SPECT) images of patients with this disease by using interface software for a 3-dimensional (3D) data extraction format. Presenting symptoms were transient ischemic attack (TIA) in 21 patients and hemorrhage in 6 patients. All the patients underwent brain SPECT scan of 123 I-iofetamine (IMP) at rest and after acetazolamide challenge (17 mg/kg iv, 2-day method). Cerebral blood flow (CBF) was quantitatively measured using arterial blood sampling and an autoradiography model. The group of the patients who presented with TIAs showed decreased CBF in the frontal lobe at rest compared to that of patients with hemorrhage, but Z-score ((mean-patient data)/ standard deviation (SD)) did not reach statistical significance. Significant CBF decrease after acetazolamide challenge was observed in a wider cerebral cortical area in the TIA group than in the hemorrhagic group. The brain region of hemodynamic ischemia (stage II) correlated well with the responsible cortical area for clinical symptoms of TIA. A hemodynamic ischemia stage image clearly represented recovery of reserve capacity after bypass surgery. Statistical evaluation of SPECT may be useful to understand and clarify the pathophysiology of this disease. (author)

Metabolite changes in the ipsilateral and contralateral cerebral hemispheres in rats with middle cerebral artery occlusion

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Lei Ruan

2017-01-01

Full Text Available Cerebral ischemia not only causes pathological changes in the ischemic areas but also induces a series of secondary changes in more distal brain regions (such as the contralateral cerebral hemisphere. The impact of supratentorial lesions, which are the most common type of lesion, on the contralateral cerebellum has been studied in patients by positron emission tomography, single photon emission computed tomography, magnetic resonance imaging and diffusion tensor imaging. In the present study, we investigated metabolite changes in the contralateral cerebral hemisphere after supratentorial unilateral ischemia using nuclear magnetic resonance spectroscopy-based metabonomics. The permanent middle cerebral artery occlusion model of ischemic stroke was established in rats. Rats were randomly divided into the middle cerebral artery occlusion 1-, 3-, 9- and 24-hour groups and the sham group. 1H nuclear magnetic resonance spectroscopy was used to detect metabolites in the left and right cerebral hemispheres. Compared with the sham group, the concentrations of lactate, alanine, γ-aminobutyric acid, choline and glycine in the ischemic cerebral hemisphere were increased in the acute stage, while the concentrations of N-acetyl aspartate, creatinine, glutamate and aspartate were decreased. This demonstrates that there is an upregulation of anaerobic glycolysis (shown by the increase in lactate, a perturbation of choline metabolism (suggested by the increase in choline, neuronal cell damage (shown by the decrease in N-acetyl aspartate and neurotransmitter imbalance (evidenced by the increase in γ-aminobutyric acid and glycine and by the decrease in glutamate and aspartate in the acute stage of cerebral ischemia. In the contralateral hemisphere, the concentrations of lactate, alanine, glycine, choline and aspartate were increased, while the concentrations of γ-aminobutyric acid, glutamate and creatinine were decreased. This suggests that there is a

Distributions and concentrations of thallium in Korean soils determined by single and sequential extraction procedures.

Science.gov (United States)

Lee, Jin-Ho; Kim, Dong-Jin; Ahn, Byung-Koo

2015-06-01

The objectives of this study were to investigate the distribution of thallium in soils collected near suspected areas such as cement plants, active and closed mines, and smelters and to examine the extraction of thallium in the soils using 19 single chemical and sequential chemical extraction procedures. Thallium concentrations in soils near cement plants were distributed between 1.20 and 12.91 mg kg(-1). However, soils near mines and smelters contained relatively low thallium concentrations ranging from 0.18 to 1.09 mg kg(-1). Thallium extractability with 19 single chemical extractants from selected soils near cement plants ranged from 0.10% to 8.20% of the total thallium concentration. In particular, 1.0 M NH4Cl, 1.0 M (NH4)2SO4, and 1.0 M CH3COONH4 extracted more thallium than other extractants. Sequential fractionation results of thallium from different soils such as industrially and artificially contaminated soils varied with the soil properties, especially soil pH and the duration of thallium contamination.

Anchusa italica extract: phytochemical and neuroprotective evaluation on global cerebral ischemia and reperfusion

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Akram Torki

2018-06-01

Full Text Available Abstract Stroke is the third leading cause of mortality and disability in industrial countries. Treatment with herbs with antioxidant properties has been reported to be an alternative to the conventional treatments. This study was conducted to investigate the effect of Anchusa italica extract on hippocampal injury induced by transient global cerebral ischemia and reperfusion in the rat. To do so, 50 rats were randomly assigned to five groups; control, sham, ischemia, and 50 or 100 mg/kg of Anchusa italica treated animals. Ischemia was induced by occlusion of carotid artery for 30 minutes. Afterward, behavioral tests and biochemical analyses were conducted. Induction of ischemia/reperfusion caused a decline in learning and passive avoidance memory in rats. Moreover, Anchusa italica caused an increase in learning and improved the passive avoidance memory. Induction of ischemia/reperfusion caused a decrease in the antioxidant capacity of the brain and serum as well as an increase in the malondialdehyde of the brain and serum. Anchusa italica led to an increase in the antioxidant capacity of the brain and serum and decrease in the malondialdehyde of the brain and serum. Overall, because of its protective effects on spatial memory, passive avoidance learning, antioxidant capacity, and lipid peroxidation during ischemia/reperfusion, Anchusa italica might be beneficial in ischemic patients.

Gastrodia and Uncaria (tianma gouteng) water extract exerts antioxidative and antiapoptotic effects against cerebral ischemia in vitro and in vivo.

Science.gov (United States)

Xian, Jia Wen; Choi, Angus Yiu-Ting; Lau, Clara Bik-San; Leung, Wing Nang; Ng, Chun Fai; Chan, Chun Wai

2016-01-01

Gastrodia and Uncaria decoction (tianma gouteng yin) is commonly used in Chinese medicine to treat cerebral ischemia. The aim of this study was to investigate the neuroprotective effects of a water extract (GUW) of Gastrodia elata (tianma; GE) and Uncaria rhynchophylla (gouteng; UR) against ischemic insult using oxygen-glucose-deprived neuronal differentiated PC12 cells and rats subjected to middle cerebral artery occlusion (MCAO). GUW was prepared by boiling raw GE and UR in water, followed by the lyophilization of the resulting extract. Neuronal differentiated PC12 cells were subjected to oxygen-glucose deprivation with or without GUW. The neuroprotective effects of GUW were compared with those of the corresponding GE and UR extracts to tease apart the effects of the different herbs. The synergistic effect of GE and UR in GUW was measured using a modified version of Burgi's formulae. The neuroprotective mechanisms via Nrf2 and anti-apoptotic pathways were investigated using real time PCR and enzyme activity assays. The neuroprotective effects of GUW were studied in vivo using a rat MCAO model. Neurofunctional outcome and brain infarct volume we assessed. H&E staining, cresyl violet staining and immunohistochemistry were performed to assess the histological outcome. The results of lactate dehydrogenase assay showed that GUW protected cells in a concentration-dependent manner (P < 0.001). Moreover, the neuroprotective effects of GUW were greater than those of GE + UR (P = 0.018). Burgi's formula showed that the herbs in GUW acted synergistically to protect cells from ischemic injury. GUW significantly upregulated Bcl-2 expression (P = 0.0130) and reduced caspase-3 activity by 60 % (P < 0.001). GUW upregulated Nrf-2 expression (P = 0.0066) and the antioxidant response element pathway genes. The infarct volume was reduced by 55 % at day 7 of reperfusion (P < 0.001), and significant improvements were observed in the neurological deficit score and beam

Comparison of first pass bolus AIFs extracted from sequential {sup 18}F-FDG PET and DSC-MRI of mice

Energy Technology Data Exchange (ETDEWEB)

Evans, Eleanor, E-mail: ee244@cam.ac.uk [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ (United Kingdom); Sawiak, Stephen J. [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ (United Kingdom); Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Cambridge, CB2 3EB (United Kingdom); Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T. [Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ (United Kingdom)

2014-01-11

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time–activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration–time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and {sup 18}F-FDG respectively to ascertain the technique′s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Gold-195m first-pass radionuclide ventriculography, thallium-201 single-photon emission CT, and 12-lead ECG stress testing as a combined procedure

International Nuclear Information System (INIS)

Kipper, S.L.; Ashburn, W.L.; Norris, S.L.; Rimkus, D.S.; Dillon, W.A.

1985-01-01

Graded, sequential, rest/exercise, gold-195m, first-pass ventriculography and thallium-201 (Tl-201) single-photon emission computed tomography (SPECT) were performed simultaneously during a single, electrocardiograph-monitored, bicycle stress test in 24 individuals. The technical aspects and logistics involved in performing this combined radionuclide study are stressed in this preliminary report. Fourteen healthy volunteers each had a normal left ventricular ejection fraction and wall-motion response, along with normal T1-201 perfusion and washout, as determined by both visual and quantitative analysis of the tomographic sections. Each of ten patients with coronary artery disease had at least one abnormality of these parameters. The authors suggest that it is technically feasible to evaluate both cardiac function and myocardial perfusion simultaneously by combing Au-195m ventriculography and Tl-201 SPECT imaging into a single, noninvasive, diagnostic package

[Mobile single-pass batch hemodialysis system in intensive care medicine. Reduction of costs and workload in renal replacement therapy].

Science.gov (United States)

Hopf, H-B; Hochscherf, M; Jehmlich, M; Leischik, M; Ritter, J

2007-07-01

This paper describes the introduction of a single-pass batch hemodialysis system for renal replacement therapy in a 14 bed intensive care unit. The goals were to reduce the workload of intensive care unit physicians using an alternative and simpler method compared to continuous veno-venous hemodiafiltration (CVVHDF) and to reduce the costs of hemofiltrate solutions (80,650 EUR per year in our clinic in 2005). We describe and evaluate the process of implementation of the system as well as the achieved and prospective savings. We conclude that a close cooperation of all participants (physicians, nurses, economists, technicians) of a hospital can achieve substantial benefits for patients and employees as well as reduce the economic burden of a hospital.

Cerebral blood flow imaging with thallium-201 diethyldithiocarbamate SPECT

NARCIS (Netherlands)

van Royen, E. A.; de Bruïne, J. F.; Hill, T. C.; Vyth, A.; Limburg, M.; Byse, B. L.; O'Leary, D. H.; de Jong, J. M.; Hijdra, A.; van der Schoot, J. B.

1987-01-01

Thallium-201 diethyldithiocarbamate ([201TI]DDC) was studied in humans as an agent for cerebral blood flow imaging. Brain uptake proved to be complete 90 sec after injection with no appreciable washout or redistribution for hours. Intracarotid injection suggested an almost 100% extraction during the

Regional cerebral blood flow and periventricular hyperintensity in silent cerebral infarction. Comparison with multi-infarct dementia

International Nuclear Information System (INIS)

Koshi, Yasuhiko; Kitamura, Shin; Nagazumi, Atushi; Tsuganesawa, Toshikazu; Terashi, Akiro

1996-01-01

In order to investigate relationship between regional cerebral blood flow (rCBF) and the white matter lesions on MRI in silent cerebral infarction, we quantitatively measured rCBF by 123 I-IMP autoradiography method (IMP ARG method) and single photon emission tomography (SPECT) in 36 patients with silent cerebral infarction (SCI group), 22 patients with multi-infarct dementia (MID group), and 16 control subjects without periventricular hyperintensity (PVH) and lacunar infarction on MRI (CL group). Regions of interest (ROIs) on rCBF images were set in the frontal (F), temporal (T), parietal (P), occipital (O) cortex, and the cerebral white matter (W). The severity of PVH on MRI T 2 -weighted image was divided into four grades (grade 0-3). Though the frequency of hypertension was significantly higher in SCI group and MID group compared with CL group, no significant difference was seen in the mean age among these three groups. rCBF in the white matter and cerebral cortices except the occipital cortex in SCI group was significantly low compared with CL group (rCBF SCI /rCBF CL : W 0.87, F 0.87, T 0.87, P 0.88, O 0.92). rCBF in the white matter and cerebral cortices, especially in the white matter and frontal cortex, in MID group was significantly low compared with SCI group (rCBF MID /rCBF CL : W 0.69, F 0.71, T 0.74, P 0.75, O 0.81). The mean grade of PVH in MID group was significantly higher than that in SCI group (SCI 1.1 vs MID 2.5). The severity of PVH was significantly correlated with each rCBF in the white matter and cerebral cortices, especially in the white matter and frontal cortex. Our findings suggest that the quantitative measurement of rCBF by IMP ARG method is useful for the follow-up study in the patients with silent cerebral infarction as well as the evaluation of the severity of PVH on MRI. (author)

Actinomyces meyeri brain abscess following dental extraction.

Science.gov (United States)

Clancy, U; Ronayne, A; Prentice, M B; Jackson, A

2015-04-13

We describe the rare occurrence of an Actinomyces meyeri cerebral abscess in a 55-year-old woman following a dental extraction. This patient presented with a 2-day history of hemisensory loss, hyper-reflexia and retro-orbital headache, 7 days following a dental extraction for apical peridonitis. Neuroimaging showed a large left parietal abscess with surrounding empyema. The patient underwent craniotomy and drainage of the abscess. A. meyeri was cultured. Actinomycosis is a rare cause of cerebral abscess. The A. meyeri subtype is particularly rare, accounting for less than 1% of specimens. This case describes an unusually brief course of the disease, which is usually insidious. Parietal lobe involvement is unusual as cerebral abscesses usually have a predilection for the frontal and temporal regions of the brain. Although there are no randomised trials to guide therapy, current consensus is to use a prolonged course of intravenous antibiotics, followed by 6-12 months of oral therapy. 2015 BMJ Publishing Group Ltd.

Depression following intracerebral hemorrhage and the evaluation of cerebral blood flow by single photon emission tomography

International Nuclear Information System (INIS)

Masada, Tetsuya; Makabe, Tetsuo; Kunishio, Katsuzo; Matsumoto, Akira

2007-01-01

The authors studied patients who presented depression and apathy following intracerebral hemorrhage (ICH). Twelve patients who were admitted in our hospital were divided into two groups according to the presence of post-stroke depression (PSD). Five patients with PSD are in group A, and another seven patients without PSD are in group B. Zung-self depression scale (SDS) and apathy scale were used for screening of depression and apathy. PSD was recognized in 5 (42%) of patients following ICH. Single photon emission tomography (SPECT) suggested the reduction of cerebral blood flow (CBF) in the frontal lobe in all patients of the group A (100%), whereas only 29% of patients of the group B. The reduction of CBF in the frontal lobe might be involved in the mechanism of depression following ICH in subacute stage. (author)

Cerebral microangiopathies

International Nuclear Information System (INIS)

Linn, Jennifer

2011-01-01

Cerebral microangiopathies are a very heterogenous group of diseases characterized by pathological changes of the small cerebral vessels. They account for 20 - 30 % of all ischemic strokes. Degenerative microangiopathy and sporadic cerebral amyloid angiography represent the typical acquired cerebral microangiopathies, which are found in over 90 % of cases. Besides, a wide variety of rare, hereditary microangiopathy exists, as e.g. CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), Fabrys disease and MELAS syndrome (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes). (orig.)

Passing and Catching in Rugby.

Science.gov (United States)

Namudu, Mike M.

This booklet contains the fundamentals for rugby at the primary school level. It deals primarily with passing and catching the ball. It contains instructions on (1) holding the ball for passing, (2) passing the ball to the left--standing, (3) passing the ball to the left--running, (4) making a switch pass, (5) the scrum half's normal pass, (6) the…

Effects of Milrinone continuous intravenous infusion on global cerebral oxygenation and cerebral vasospasm after cerebral aneurysm surgical clipping

Directory of Open Access Journals (Sweden)

Mohamed A. Ghanem

2014-01-01

Conclusions: Milrinone improved significantly the global cerebral oxygenation and reduced the incidence of cerebral vasospasm during the dangerous period of cerebral spasm after cerebral aneurysm clipping.

Cerebral near infrared spectroscopy oximetry in extremely preterm infants : Phase II randomised clinical trial

NARCIS (Netherlands)

Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas; Austin, Topun; Van Bel, Frank; Benders, Manon; Claris, Olivier; Dempsey, Eugene; Franz, Axel R.; Fumagalli, Monica; Gluud, Christian; Grevstad, Berit; Hagmann, Cornelia; Lemmers, Petra; Van Oeveren, Wim; Pichler, Gerhard; Plomgaard, Anne Mette; Riera, Joan; Sanchez, Laura; Winkel, Per; Wolf, Martin; Greisen, Gorm

2015-01-01

Objective: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. Design: Phase II randomised, single blinded, parallel clinical trial. Setting Eight tertiary neonatal intensive care units in

Extraction of tributyltin and triphenyltin across a single oil droplet/water interface

International Nuclear Information System (INIS)

Chikama, Katsumi; Negishi, Takayuki; Nakatani, Kiyoharu

2004-01-01

Tributyltin (TBT + ) and triphenyltin (TPT + ) were extracted with merocyanine 540 (MC - ) from water into a 1,6-dichlorohexane droplet with the radius of 40 μm and the absorption spectra of MC - were measured by a single microdroplet manipulation and microabsorption technique. The mass transfer rate and the partitioning ratio of MC - were characteristically influenced by the TBT + , TPT + , MC - , and Cl - concentrations in water. The ion pair extraction processes of the organotin compounds with the anions were discussed in terms of the ion transfer and adsorption-desorption of the solutes

A double-pass interferometer for measurement of dimensional changes

International Nuclear Information System (INIS)

Ren, Dongmei; Lawton, K M; Miller, J A

2008-01-01

A double-pass interferometer was developed for measuring dimensional changes of materials in a nanoscale absolute interferometric dilatometer. This interferometer realized the double-ended measurement of a sample using a single-detection double-pass interference system. The nearly balanced design, in which the measurement beam and the reference beam have equal optical path lengths except for the path difference caused by the sample itself, makes this interferometer have high stability, which is verified by the measurement of a quasi-zero-length sample. The preliminary experiments and uncertainty analysis show that this interferometer should be able to measure dimensional changes with characteristic uncertainty at the nanometer level

Extraction of [99mTc]-d,l-HM-PAO across the blood-brain barrier

DEFF Research Database (Denmark)

Andersen, A R; Friberg, H; Knudsen, K B

1988-01-01

The initial extraction (E) across the blood-brain barrier (BBB) of [99mTc]-d,l-HM-PAO after intracarotid injection was measured in 14 Wistar rats and 6 patients using the double indicator, single injection method with Na-24 as the cotracer. In both series, cerebral blood flow (CBF) was measured...... was increased from 20 to 120 microliters, while using a 120 microliters bolus containing 10% albumin resulted in a decrease in E. This suggests that HM-PAO binding to albumin is not totally and rapidly reversible during a single passage through brain capillaries and that binding to blood elements may reduce...... the apparent extraction across brain capillaries. In patients using a bolus of 1 ml saline, E decreased linearly with increasing CBF (r = -0.81, p less than 0.001). For a CBF of 0.59 ml/g/min and an average apparent E of 0.72, an apparent PS product of 0.76 ml/g/min was calculated.(ABSTRACT TRUNCATED AT 250...

Regional cerebral blood flow in pure dysarthria. A 3D-SSP study

International Nuclear Information System (INIS)

Okamoto, Kensho; Kamogawa, Kenji; Okuda, Bungo; Kawabata, Keita; Tachibana, Hisao

2007-01-01

Pure dysarthria from brain infarction is a rare condition, and its pathophysiology remains unclear. To clarify the underlying mechanism of pure dysarthria, we investigated the lesion sites and regional cerebral blood flow in patients with pure dysarthria. We examined 18 consecutive patients with pure dysarthria (9 men and 9 women; mean age, 71 years) who underwent MRI and cerebral blood flow studies. To visualize the regional cerebral blood flow, we generated Z score images using the three-dimensional stereotactic surface projection (3D-SSP) method with single-photon emission computed tomography (SPECT) and N-isopropyl-p [ 123 I]iodoamphetamine. Data on the brain surface perfusion extracted by the 3D-SSP analysis were compared between the pure dysarthria (PD) patients and 9 control subjects. MRI revealed multiple lacunar infarctions involving the internal capsule and/or corona radiata in 11 patients, left internal capsule-corona radiata infarction in 4 patients, and pontine infarction in 3 patients. SPECT with 3D-SSP demonstrated bilateral frontal cortical hypoperfusion in all patients, particularly in the anterior opercular region. Based on intergroup comparisons, the PD group exhibited pronounced cortical hypoperfusion in the opercular and medial frontal regions, left more than right. In conclusion, pure dysarthria is considered to originate from frontal cortical hypoperfusion, mainly in the anterior opercular and medial frontal regions, which is probably due to interruption of the corticosubcortical neural networks relevant to speech expression and articulation. In addition, it is suggested that left hemispheric lesions may make a greater contribution to the development of pure dysarthria than do right ones. (author)

Sea ice local surface topography from single-pass satellite InSAR measurements: a feasibility study

Directory of Open Access Journals (Sweden)

W. Dierking

2017-08-01

Full Text Available Quantitative parameters characterizing the sea ice surface topography are needed in geophysical investigations such as studies on atmosphere–ice interactions or sea ice mechanics. Recently, the use of space-borne single-pass interferometric synthetic aperture radar (InSAR for retrieving the ice surface topography has attracted notice among geophysicists. In this paper the potential of InSAR measurements is examined for several satellite configurations and radar frequencies, considering statistics of heights and widths of ice ridges as well as possible magnitudes of ice drift. It is shown that, theoretically, surface height variations can be retrieved with relative errors  ≤  0.5 m. In practice, however, the sea ice drift and open water leads may contribute significantly to the measured interferometric phase. Another essential factor is the dependence of the achievable interferometric baseline on the satellite orbit configurations. Possibilities to assess the influence of different factors on the measurement accuracy are demonstrated: signal-to-noise ratio, presence of a snow layer, and the penetration depth into the ice. Practical examples of sea surface height retrievals from bistatic SAR images collected during the TanDEM-X Science Phase are presented.

Real-time extraction of bubble chamber tracks using a single vidicon

International Nuclear Information System (INIS)

Roos, C.E.

1978-01-01

Bubble Chamber pictures show many undesired tracks and background in addition to the tracks of the desired significant event. Settles et al. have described a technique for optical tagging of an event by adding a darkfield photograph taken before significant bubble growth to a later brightfield photograph. The authors describe a system to cancel out all picture detail except for the wanted tracks by using a single vidicon tube as the storage device. In the first exposure, polarized light is imaged on the vidicon after passing through a Ronchi grating placed at a focal plane. Thus half of the target is exposed in a series of vertical stripes. The second exposure uses light polarized orthogonally to the first exposure and is deflected after passing through the Ronchi grating so as to expose the previously occluded stripes on the target. The target is then scanned orthogonally to the stripes; by subtracting the picture contained in one set of stripes from that contained in the other set, only the differences between the two images remains. A simulation was conducted using continuously presented background of one polarization and background plus tracks of the other polarization. The test showed that the added tracks were easily resolved, even though they were not readily discernible by visual inspection prior to subtraction. (Auth.)

Effects of Changes in Arterial Carbon Dioxide and Oxygen Partial Pressures on Cerebral Oximeter Performance.

Science.gov (United States)

Schober, Andrew; Feiner, John R; Bickler, Philip E; Rollins, Mark D

2018-01-01

Cerebral oximetry (cerebral oxygen saturation; ScO2) is used to noninvasively monitor cerebral oxygenation. ScO2 readings are based on the fraction of reduced and oxidized hemoglobin as an indirect estimate of brain tissue oxygenation and assume a static ratio of arterial to venous intracranial blood. Conditions that alter cerebral blood flow, such as acute changes in PaCO2, may decrease accuracy. We assessed the performance of two commercial cerebral oximeters across a range of oxygen concentrations during normocapnia and hypocapnia. Casmed FORE-SIGHT Elite (CAS Medical Systems, Inc., USA) and Covidien INVOS 5100C (Covidien, USA) oximeter sensors were placed on 12 healthy volunteers. The fractional inspired oxygen tension was varied to achieve seven steady-state levels including hypoxic and hyperoxic PaO2 values. ScO2 and simultaneous arterial and jugular venous blood gas measurements were obtained with both normocapnia and hypocapnia. Oximeter bias was calculated as the difference between the ScO2 and reference saturation using manufacturer-specified weighting ratios from the arterial and venous samples. FORE-SIGHT Elite bias was greater during hypocapnia as compared with normocapnia (4 ± 9% vs. 0 ± 6%; P oxygen saturation and mixed venous oxygen tension, as well as increased oxygen extraction across fractional inspired oxygen tension levels (P oxygen extraction (P < 0.0001). Changes in PaCO2 affect cerebral oximeter accuracy, and increased bias occurs with hypocapnia. Decreased accuracy may represent an incorrect assumption of a static arterial-venous blood fraction. Understanding cerebral oximetry limitations is especially important in patients at risk for hypoxia-induced brain injury, where PaCO2 may be purposefully altered.

Brain MRI and single photon emission computed tomography in severe athetotic cerebral palsy. A comparative study with mental and motor disorders

International Nuclear Information System (INIS)

Yamada, Kazutaka; Tsuzura, Shigenobu; Matsuda, Hiroshi.

1995-01-01

Single photon emission computed tomography (SPECT) using N-isopropyl-p-[ 123 I]-iodoamphetamine ( 123 I-IMP) was performed in twelve patients with severe athetotic cerebral palsy (Ath; 5 males and 7 females) who had both motor delay (unable to move) and mental retardation (I.Q, or D.Q, below 30). The neuroimaging findings of those patients were compared with those of patients mental and motor disorders. In five caes suffering from neonatal asphyxia, SPECT demonstrated a decreased regional cerebral blood flow (rCBF) in corpus striatum, thalamus, orbitofrontal areas, pericentral gyrus areas, prefrontal areas and medial temporal areas. In seven cases suffering from neonatal jaundice, SPECT demonstrated a decreased rCBF in orbito-frontal areas, prefrontal areas and medial temporal areas. SPECT showed hypoperfusion of peri-central gyrus areas in cases with complications of spastic palsy. The decreased rCBF in medial temporal areas mostly corresponded to an alteration in hippocampal formation as assessed by magnetic resonance imaging (MRI). Cases with hypoperfusion of bilateral medial temporal areas showed a lower score of language understanding than those with the unilateral damage. In cases with hypofusion of bilateral prefrontal areas and bilateral medial temporal areas, the grade of understanding of language was almost below 12 months. In cases with hypoperfusion of orbitofrontal areas, psychomotor hypersensitivity had been observed. Those results suggest that IMP-SPECT and MRI of the brain is useful tool for neurological assessment in handicapped patients with athetotic cerebral palsy. (author)

Brain MRI and single photon emission computed tomography in severe athetotic cerebral palsy. A comparative study with mental and motor disorders

Energy Technology Data Exchange (ETDEWEB)

Yamada, Kazutaka; Tsuzura, Shigenobu [Metropolitan Medical Center of the Severely Handicapped, Fuchu, Tokyo (Japan); Matsuda, Hiroshi

1995-07-01

Single photon emission computed tomography (SPECT) using N-isopropyl-p-[{sup 123}I]-iodoamphetamine ({sup 123}I-IMP) was performed in twelve patients with severe athetotic cerebral palsy (Ath; 5 males and 7 females) who had both motor delay (unable to move) and mental retardation (I.Q, or D.Q, below 30). The neuroimaging findings of those patients were compared with those of patients mental and motor disorders. In five caes suffering from neonatal asphyxia, SPECT demonstrated a decreased regional cerebral blood flow (rCBF) in corpus striatum, thalamus, orbitofrontal areas, pericentral gyrus areas, prefrontal areas and medial temporal areas. In seven cases suffering from neonatal jaundice, SPECT demonstrated a decreased rCBF in orbito-frontal areas, prefrontal areas and medial temporal areas. SPECT showed hypoperfusion of peri-central gyrus areas in cases with complications of spastic palsy. The decreased rCBF in medial temporal areas mostly corresponded to an alteration in hippocampal formation as assessed by magnetic resonance imaging (MRI). Cases with hypoperfusion of bilateral medial temporal areas showed a lower score of language understanding than those with the unilateral damage. In cases with hypofusion of bilateral prefrontal areas and bilateral medial temporal areas, the grade of understanding of language was almost below 12 months. In cases with hypoperfusion of orbitofrontal areas, psychomotor hypersensitivity had been observed. Those results suggest that IMP-SPECT and MRI of the brain is useful tool for neurological assessment in handicapped patients with athetotic cerebral palsy. (author).

Study of the therapeutic effects of a hippotherapy simulator in children with cerebral palsy: a stratified single-blind randomized controlled trial.

Science.gov (United States)

Herrero, Pablo; Gómez-Trullén, Eva M; Asensio, Angel; García, Elena; Casas, Roberto; Monserrat, Esther; Pandyan, Anand

2012-12-01

To investigate whether hippotherapy (when applied by a simulator) improves postural control and balance in children with cerebral palsy. Stratified single-blind randomized controlled trial with an independent assessor. Stratification was made by gross motor function classification system levels, and allocation was concealed. Children between 4 and 18 years old with cerebral palsy. Participants were randomized to an intervention (simulator ON) or control (simulator OFF) group after getting informed consent. Treatment was provided once a week (15 minutes) for 10 weeks. Gross Motor Function Measure (dimension B for balance and the Total Score) and Sitting Assessment Scale were carried out at baseline (prior to randomization), end of intervention and 12 weeks after completing the intervention. Thirty-eight children participated. The groups were balanced at baseline. Sitting balance (measured by dimension B of the Gross Motor Function Measure) improved significantly in the treatment group (effect size = 0.36; 95% CI 0.01-0.71) and the effect size was greater in the severely disabled group (effect size = 0.80; 95% CI 0.13-1.47). The improvements in sitting balance were not maintained over the follow-up period. Changes in the total score of the Gross Motor Function Measure and the Sitting Assessment Scale were not significant. Hippotherapy with a simulator can improve sitting balance in cerebral palsy children who have higher levels of disability. However, this did not lead to a change in the overall function of these children (Gross Motor Function Classification System level V).

Preliminary EEG study of protective effects of Tebonin in transient global cerebral ischemia in rats

DEFF Research Database (Denmark)

Zagrean, L; Vatasescu, R; Munteanu, A M

2000-01-01

and metabolism. The objective of this study was to investigate the effects of preventive treatment with Ginkgo biloba extract (EGb 761--Tebonin) in cerebral global ischemia and reperfusion in rats using computerized EEG analysis. Ginkgo biloba extract, known to be, in vitro, a free radicals scavanger and a PAF......--antagonist, was administrated in dose of 100 mg/kg over 24 hours, for 5 days before and 5 days after cerebral ischemia--reperfusion. The apparition of isoelectric EEG (flat-line) following 4-vessel occlusion was observed after a mean time of 25 sec. in Ginkgo biloba treated rats and after 18 sec. in control rats (p

Field trial of a fast single-pass transmit-receive probe during Gentilly II steam generator tube inspection

International Nuclear Information System (INIS)

Obrutsky, L.; Cantin, M.; Renaud, J.; Cecco, V.; Lakhan, R.; Sullivan, S.

2000-01-01

A new generation of transmit-receive single-pass probes, denoted as C6 or X probe, was field tested during the Gentilly II, 2000 steam generator tube inspection. This probe has a performance equivalent to rotating probes and can be used for tubesheet and full-length inspection at an inspection speed equivalent to that of bobbin probes. Existing C3 transmit-receive probes have been demonstrated to be effective in detecting circumferential cracks. The C5 probe can detect both circumferential and axial cracks and volumetric defects but cannot discriminate between them. The C6 probe expands on the capabilities of both probes in a single probe head. It can simultaneously detect and discriminate between circumferential and axial cracks to satisfy different plugging criteria. It has excellent coverage, good defect detectability, and improved sizing and characterization. Probe data is displayed in C-scan format so that the amount of data to be analyzed is similar to rotating probes. The C6 probe will significantly decrease inspection time and the need for re-inspection and tube pulling. This paper describes the advantages of the probe and demonstrates its capabilities employing signals from tube samples with calibration flaws and laboratory induced cracks. It shows the results from the field trial of the probe at Gentilly II and describes the instrumentation, hardware and software used for the inspection. (author)

Field trial of a fast single-pass transmit-receive probe during Gentilly II steam generator tube inspection

International Nuclear Information System (INIS)

Obrutsky, L.; Cantin, M.; Renaud, J.; Cecco, V.; Lakhan, R.; Sullivan, S.

2000-01-01

A new generation of transmit-receive single-pass probes, denoted as C6 or X probe, was field-tested during the Gentilly II, 2000 steam generator tube inspection. This probe has a performance equivalent to rotating probes and can be used for tubesheet and full-length inspection at an inspection speed equivalent to that of bobbin probes. Existing C3 transmit-receive probes have been demonstrated to be effective in detecting circumferential cracks. The C5 probe can detect both circumferential and axial cracks and volumetric defects but cannot discriminate between them. The C6 probe expands on the capabilities of both probes in a single probe head. It can simultaneously detect and discriminate between circumferential and axial cracks to satisfy different plugging criteria. It has excellent coverage, good defect detectability, and improved sizing and characterization. Probe data is displayed in C-scan format so that the amount of data to be analyzed is similar to rotating probes. The C6 probe will significantly decrease inspection time and the need for re-inspection and tube pulling. This paper describes the advantages of the probe and demonstrates its capabilities employing signals from tube samples with calibration flaws and laboratory induced cracks. It shows the results from the field trial of the probe at Gentilly II and describes the instrumentation, hardware and software used for the inspection. (author)

Quantitative Analysis of First-Pass Contrast-Enhanced Myocardial Perfusion Multidetector CT Using a Patlak Plot Method and Extraction Fraction Correction During Adenosine Stress

Science.gov (United States)

Ichihara, Takashi; George, Richard T.; Silva, Caterina; Lima, Joao A. C.; Lardo, Albert C.

2011-02-01

The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement that can be used to derive accurate myocardial perfusion measurements from dynamic multidetector computed tomography (MDCT) images by using a compartment model for calculating the first-order transfer constant (K1) with correction for the capillary transit extraction fraction (E). Six canine models of left anterior descending (LAD) artery stenosis were prepared and underwent first-pass contrast-enhanced MDCT perfusion imaging during adenosine infusion (0.14-0.21 mg/kg/min). K1 , which is the first-order transfer constant from left ventricular (LV) blood to myocardium, was measured using the Patlak plot method applied to time-attenuation curve data of the LV blood pool and myocardium. The results were compared against microsphere MBF measurements, and the extraction fraction of contrast agent was calculated. K1 is related to the regional MBF as K1=EF, E=(1-exp(-PS/F)), where PS is the permeability-surface area product and F is myocardial flow. Based on the above relationship, a look-up table from K1 to MBF can be generated and Patlak plot-derived K1 values can be converted to the calculated MBF. The calculated MBF and microsphere MBF showed a strong linear association. The extraction fraction in dogs as a function of flow (F) was E=(1-exp(-(0.2532F+0.7871)/F)) . Regional MBF can be measured accurately using the Patlak plot method based on a compartment model and look-up table with extraction fraction correction from K1 to MBF.

Buffels (Wes), Elsies, Sir Lowry's pass, Steenbras and Buffels (Oos)

CSIR Research Space (South Africa)

Heinecken, TJE

1982-06-01

Full Text Available This report is a synthesis of all available information on five of the smaller rivers discharging in to False bay combined as a single volume. The rivers dealt with are the Buffels (Wes), Elsies, Sir Lowry' Pass, Steenbras and Buffels (Oos). False...

Genomic analysis identifies masqueraders of full-term cerebral palsy.

Science.gov (United States)

Takezawa, Yusuke; Kikuchi, Atsuo; Haginoya, Kazuhiro; Niihori, Tetsuya; Numata-Uematsu, Yurika; Inui, Takehiko; Yamamura-Suzuki, Saeko; Miyabayashi, Takuya; Anzai, Mai; Suzuki-Muromoto, Sato; Okubo, Yukimune; Endo, Wakaba; Togashi, Noriko; Kobayashi, Yasuko; Onuma, Akira; Funayama, Ryo; Shirota, Matsuyuki; Nakayama, Keiko; Aoki, Yoko; Kure, Shigeo

2018-05-01

Cerebral palsy is a common, heterogeneous neurodevelopmental disorder that causes movement and postural disabilities. Recent studies have suggested genetic diseases can be misdiagnosed as cerebral palsy. We hypothesized that two simple criteria, that is, full-term births and nonspecific brain MRI findings, are keys to extracting masqueraders among cerebral palsy cases due to the following: (1) preterm infants are susceptible to multiple environmental factors and therefore demonstrate an increased risk of cerebral palsy and (2) brain MRI assessment is essential for excluding environmental causes and other particular disorders. A total of 107 patients-all full-term births-without specific findings on brain MRI were identified among 897 patients diagnosed with cerebral palsy who were followed at our center. DNA samples were available for 17 of the 107 cases for trio whole-exome sequencing and array comparative genomic hybridization. We prioritized variants in genes known to be relevant in neurodevelopmental diseases and evaluated their pathogenicity according to the American College of Medical Genetics guidelines. Pathogenic/likely pathogenic candidate variants were identified in 9 of 17 cases (52.9%) within eight genes: CTNNB1 , CYP2U1 , SPAST , GNAO1 , CACNA1A , AMPD2 , STXBP1 , and SCN2A . Five identified variants had previously been reported. No pathogenic copy number variations were identified. The AMPD2 missense variant and the splice-site variants in CTNNB1 and AMPD2 were validated by in vitro functional experiments. The high rate of detecting causative genetic variants (52.9%) suggests that patients diagnosed with cerebral palsy in full-term births without specific MRI findings may include genetic diseases masquerading as cerebral palsy.

Extraction of tributyltin and triphenyltin across a single oil droplet/water interface

Energy Technology Data Exchange (ETDEWEB)

Chikama, Katsumi; Negishi, Takayuki; Nakatani, Kiyoharu

2004-07-01

Tributyltin (TBT{sup +}) and triphenyltin (TPT{sup +}) were extracted with merocyanine 540 (MC{sup -}) from water into a 1,6-dichlorohexane droplet with the radius of 40 {mu}m and the absorption spectra of MC{sup -} were measured by a single microdroplet manipulation and microabsorption technique. The mass transfer rate and the partitioning ratio of MC{sup -} were characteristically influenced by the TBT{sup +}, TPT{sup +}, MC{sup -}, and Cl{sup -} concentrations in water. The ion pair extraction processes of the organotin compounds with the anions were discussed in terms of the ion transfer and adsorption-desorption of the solutes.

A new approach to the extraction of single exponential diode model parameters

Science.gov (United States)

Ortiz-Conde, Adelmo; García-Sánchez, Francisco J.

2018-06-01

A new integration method is presented for the extraction of the parameters of a single exponential diode model with series resistance from the measured forward I-V characteristics. The extraction is performed using auxiliary functions based on the integration of the data which allow to isolate the effects of each of the model parameters. A differentiation method is also presented for data with low level of experimental noise. Measured and simulated data are used to verify the applicability of both proposed method. Physical insight about the validity of the model is also obtained by using the proposed graphical determinations of the parameters.

Usefulness of the classification technique of cerebral artery for 2D/3D registration

International Nuclear Information System (INIS)

Takemura, Akihiro; Suzuki, Masayuki; Kikuchi, Yuzo; Okumura, Yusuke; Harauchi, Hajime

2007-01-01

Several papers have proposed 2D/3D registration methods of the cerebral artery using magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). Since differences between vessels in a DSA image and MRA volume data cause registration failure, we previously proposed a method to extract vessels from MRA volume data using a technique based on classification of the cerebral artery. In this paper, we evaluated the usefulness of this classification technique by evaluating the reliability of this 2D/3D registration method. This classification method divides the cerebral artery in MRA volume data into 12 segments. According to the results of the classification, structures corresponding to vessels on a DSA image can then be extracted. We applied the 2D/3D registration with/without classification to 16 pairs of MRA volume data and DSA images obtained from six patients. The registration results were scored into four levels (Excellent, Good, Fair and Poor). The rates of successful registration (>fair) were 37.5% for registration without classification and 81.3% for that with classification. These findings suggested that there was a low percentage of incorrectly extracted voxels and we could facilitate reliable registration. Thus, the classification technique was shown to be useful for feature-based 2D/3D registration. (author)

Anestesia e paralisia cerebral Anestesia y parálisis cerebral Anesthesia and cerebral palsy

Directory of Open Access Journals (Sweden)

Március Vinícius M Maranhão

2005-12-01

Full Text Available JUSTIFICATIVA E OBJETIVOS: A paralisia cerebral (PC é uma doença não progressiva decorrente de lesão no sistema nervoso central, levando a um comprometimento motor do paciente. O portador de PC freqüentemente é submetido a procedimentos cirúrgicos devido a doenças usuais e situações particulares decorrentes da paralisia cerebral. Foi objetivo deste artigo revisar aspectos da paralisia cerebral de interesse para o anestesiologista, permitindo um adequado manuseio pré, intra e pós-operatório neste tipo de paciente. CONTEÚDO: O artigo aborda aspectos da paralisia cerebral como etiologia, classificação, fatores de risco, fisiopatologia, quadro clínico, diagnóstico, terapêuticas utilizadas bem como avaliação pré-operatória, medicação pré-anestésica, manuseio intra e pós-operatório, analgesia pós-operatória e dor crônica. CONCLUSÕES: O anestesiologista desempenha um papel importante na diminuição da morbidade e mortalidade anestésico-cirúrgica em pacientes portadores de paralisia cerebral. O conhecimento da fisiopatologia dos diferentes tipos de paralisia cerebral bem como das doenças associadas e suas terapêuticas é imprescindível, pois permite ao anestesiologista antecipar e prevenir complicações intra e pós-operatórias neste tipo de paciente.JUSTIFICATIVA Y OBJETIVOS: La parálisis cerebral (PC es una enfermedad no progresiva consecuente de una lesión en el sistema nervioso central, llevando a un comprometimiento motor del paciente. El portador de PC, frecuentemente es sometido a procedimientos quirúrgicos debido a enfermedades usuales y situaciones particulares consecuentes de la parálisis cerebral. El objetivo de este artículo, fue revisar aspectos de la parálisis cerebral de interés para el anestesista, permitiendo un adecuado manoseo pre, intra y posoperatorio en este tipo de paciente. CONTENIDO: El artículo aborda aspectos de la parálisis cerebral como etiología, clasificación, factores de

Fourier transform profilometry (FTP) using an innovative band-pass filter for accurate 3-D surface reconstruction

Science.gov (United States)

Chen, Liang-Chia; Ho, Hsuan-Wei; Nguyen, Xuan-Loc

2010-02-01

This article presents a novel band-pass filter for Fourier transform profilometry (FTP) for accurate 3-D surface reconstruction. FTP can be employed to obtain 3-D surface profiles by one-shot images to achieve high-speed measurement. However, its measurement accuracy has been significantly influenced by the spectrum filtering process required to extract the phase information representing various surface heights. Using the commonly applied 2-D Hanning filter, the measurement errors could be up to 5-10% of the overall measuring height and it is unacceptable to various industrial application. To resolve this issue, the article proposes an elliptical band-pass filter for extracting the spectral region possessing essential phase information for reconstructing accurate 3-D surface profiles. The elliptical band-pass filter was developed and optimized to reconstruct 3-D surface models with improved measurement accuracy. Some experimental results verify that the accuracy can be effectively enhanced by using the elliptical filter. The accuracy improvement of 44.1% and 30.4% can be achieved in 3-D and sphericity measurement, respectively, when the elliptical filter replaces the traditional filter as the band-pass filtering method. Employing the developed method, the maximum measured error can be kept within 3.3% of the overall measuring range.

Vascular risk factors, atherosclerosis, cerebral white matter lesions and cerebral perfusion in a population-based study

International Nuclear Information System (INIS)

Claus, J.J.; Breteler, M.M.B.; Hasan, D.; Krenning, E.P.; Bots, M.L.; Grobbee, D.E.; Swieten, J.C. van; Harskamp, F. van; Hofman, A.

1996-01-01

We studied risk factors for cerebral vascular disease (blood pressure and hypertension, factor VIIc, factor VIIIc, fibrinogen), indicators of atherosclerosis (intima-media thickness and plaques in the carotid artery) and cerebral white matter lesions in relation to regional cerebral blood flow (rCBF) in 60 persons (aged 65-85 years) recruited from a population-based study. rCBF was assessed with single-photon emission tomography using technetium-99m d,l-hexamethylpropylene amine oxime ( 99m Tc-HMPAO). Statistical analysis was performed with multiple linear regression with adjustment for age, sex and ventricle-to-brain ratio. A significant positive association was found between systolic and diastolic blood pressure and temporo-parietal rCBF. In analysis with quartiles of the distribution, we found a threshold effect for the relation of low diastolic blood pressure (≤60 mmHg) and low temporo-parietal rCBF. Levels of plasma fibrinogen were inversely related to parietal rCBF, with a threshold effect of high fibrinogen levels (>3.2 g/l) and low rCBF. Increased atherosclerosis was related to low rCBF in all cortical regions, but these associations were not significant. No consistent relation was observed between severity of cerebral white matter lesions and rCBF. Our results may have implications for blood pressure control in the elderly population. (orig.)

Uranium, Plutonium and Neptunium Co-recovery with Irradiated Fast Reactor MOX Fuel by Single Cycle Extraction Process

Energy Technology Data Exchange (ETDEWEB)

Masaumi Nakahara; Yuichi Sano; Kazunori Nomura; Tadahiro Washiya; Jun Komaki [Japan Atomic Energy Agency, 4-33 Muramatsu, Tokai-mura, Naka-gun, Ibaraki, 319-1194 (Japan)

2008-07-01

The behavior of Np in single cycle extraction processes using tri-n-butylphosphate (TBP) as an extractant for U, Pu and Np co-recovery was investigated as a part of NEXT (New Extraction System for Transuranium) process. Two approaches for Np co-recovery with U and Pu were carried out with irradiated MOX fuel from fast reactor 'JOYO'; one was the counter current experiment using a feed solution with a high HNO{sub 3} concentration and the other used a scrubbing solution with a high HNO{sub 3} concentration. Experimental results showed that the leakage of Np to the raffinate were 0.986 % and 5.96 % under the condition of high HNO{sub 3} concentration in the feed solution and scrubbing solution, respectively. The simulation results based on these experiments indicated that most of Np could be extracted and co-recovered with U and Pu, just by increasing HNO{sub 3} concentrations in the feed and scrubbing solution on the single cycle extraction process. (authors)

Upper limb robot-assisted therapy in cerebral palsy: a single-blind randomized controlled trial.

Science.gov (United States)

Gilliaux, Maxime; Renders, Anne; Dispa, Delphine; Holvoet, Dominique; Sapin, Julien; Dehez, Bruno; Detrembleur, Christine; Lejeune, Thierry M; Stoquart, Gaëtan

2015-02-01

Several pilot studies have evoked interest in robot-assisted therapy (RAT) in children with cerebral palsy (CP). To assess the effectiveness of RAT in children with CP through a single-blind randomized controlled trial. Sixteen children with CP were randomized into 2 groups. Eight children performed 5 conventional therapy sessions per week over 8 weeks (control group). Eight children completed 3 conventional therapy sessions and 2 robot-assisted sessions per week over 8 weeks (robotic group). For both groups, each therapy session lasted 45 minutes. Throughout each RAT session, the patient attempted to reach several targets consecutively with the REAPlan. The REAPlan is a distal effector robot that allows for displacements of the upper limb in the horizontal plane. A blinded assessment was performed before and after the intervention with respect to the International Classification of Functioning framework: body structure and function (upper limb kinematics, Box and Block test, Quality of Upper Extremity Skills Test, strength, and spasticity), activities (Abilhand-Kids, Pediatric Evaluation of Disability Inventory), and participation (Life Habits). During each RAT session, patients performed 744 movements on average with the REAPlan. Among the variables assessed, the smoothness of movement (P robotic group than in the control group. This single-blind randomized controlled trial provides the first evidence that RAT is effective in children with CP. Future studies should investigate the long-term effects of this therapy. © The Author(s) 2014.

Lycium barbarum Extracts Protect the Brain from Blood-Brain Barrier Disruption and Cerebral Edema in Experimental Stroke

Science.gov (United States)

Yang, Di; Li, Suk-Yee; Yeung, Chung-Man; Chang, Raymond Chuen-Chung; So, Kwok-Fai; Wong, David; Lo, Amy C. Y.

2012-01-01

Background and Purpose Ischemic stroke is a destructive cerebrovascular disease and a leading cause of death. Yet, no ideal neuroprotective agents are available, leaving prevention an attractive alternative. The extracts from the fruits of Lycium barbarum (LBP), a Chinese anti-aging medicine and food supplement, showed neuroprotective function in the retina when given prophylactically. We aim to evaluate the protective effects of LBP pre-treatment in an experimental stroke model. Methods C57BL/6N male mice were first fed with either vehicle (PBS) or LBP (1 or 10 mg/kg) daily for 7 days. Mice were then subjected to 2-hour transient middle cerebral artery occlusion (MCAO) by the intraluminal method followed by 22-hour reperfusion upon filament removal. Mice were evaluated for neurological deficits just before sacrifice. Brains were harvested for infarct size estimation, water content measurement, immunohistochemical analysis, and Western blot experiments. Evans blue (EB) extravasation was determined to assess blood-brain barrier (BBB) disruption after MCAO. Results LBP pre-treatment significantly improved neurological deficits as well as decreased infarct size, hemispheric swelling, and water content. Fewer apoptotic cells were identified in LBP-treated brains by TUNEL assay. Reduced EB extravasation, fewer IgG-leaky vessels, and up-regulation of occludin expression were also observed in LBP-treated brains. Moreover, immunoreactivity for aquaporin-4 and glial fibrillary acidic protein were significantly decreased in LBP-treated brains. Conclusions Seven-day oral LBP pre-treatment effectively improved neurological deficits, decreased infarct size and cerebral edema as well as protected the brain from BBB disruption, aquaporin-4 up-regulation, and glial activation. The present study suggests that LBP may be used as a prophylactic neuroprotectant in patients at high risk for ischemic stroke. PMID:22438957

Positron emission tomographic measurement of acute hemodynamic changes in primate middle cerebral artery occlusion

Energy Technology Data Exchange (ETDEWEB)

Tenjin, Hiroshi; Ueda, Satoshi; Mizukawa, Norihiko [Kyoto Prefectural Univ. of Medicine (Japan); and others

1992-10-01

Specific hemodynamic changes in acute ischemia were investigated using a middle cerebral artery occlusion primate model and positron emission tomography. The cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate for oxygen were measured 1, 3, and 9 hours after occlusion. OEF showed an increase in ischemic areas, and especially where CBF was below 18 ml/100 gm/min 1 hour after occlusion the OEF increased significantly (0.69[+-]0.20, p<0.05). Nine hours after occlusion, the OEF values were lower compared to those 1 and 3 hours after occlusion. Areas where CBF ranged from 18 to 31 ml/100 gm/min showed an increase in OEF at all times (p<0.05). Clearly, OEF changes remarkably in the acute stage. (author).

Cerebral toxoplasmosis in AIDS - computerized tomography evaluation; Toxoplasmose cerebral na SIDA - avaliacao por tomografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Alves, Regina Coeli Fonseca [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Hospital Universitario Antonio Pedro. Servico de Radiologia; Narchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia

1999-06-01

Cerebral toxoplasmosis is a disease that affects many AIDS's patients. FOr this paper 46 patients with confirmed cases of cerebral toxoplasmosis who did a CT scan between March, 1994 and September, 1997 were examined. Single lesions were found in 28.3% of the patients. The lesions were more frequently detected in the basal ganglia and the frontal lobes. No lesion was larger than 4 cm. As regards the contrast enhancing of the lesions on a CT scan we observed that 54.5% of the lesions had a ring-like contrast enhancing, 36.4% had a nodular contrast enhancing and 6% had a heterogeneous form. After the 21st day of treatment we noticed an improvement in the aspect of the patients'lesions. The improvement of the lesions could be seen through a reduction of the edematous halo, a reduction of the lesion size and a modification in the contrast enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility with cerebral toxoplasmosis, as well as to monitor these patients during treatment. (author)

Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model

OpenAIRE

Sutton, Steven C.; Rinaldi, M. T. S.; Vukovinsky, K. E.

2001-01-01

This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red, 14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Wat...

Brain imaging during seizure: ictal brain SPECT

International Nuclear Information System (INIS)

Kottamasu, Sambasiva Rao

1997-01-01

The role of single photon computed tomography (SPECT) in presurgical localization of medically intractable complex partial epilepsy (CPE) in children is reviewed. 99m Technetium neurolite, a newer lipophylic agent with a high first pass brain extraction and little or no redistribution is injected during a seizure, while the child is monitored with a video recording and continuous EEG and SPECT imaging is performed in the next 1-3 hours with the images representing regional cerebral profusion at the time of injection. On SPECT studies performed with radiopharmaceutical injected during a seizure, ictal focus is generally hypervascular. Other findings on ictal brain SPECT include hypoperfusion of adjacent cerebral cortex and white matter, hyperperfusion of contralateral motor cortex, hyperperfusion of ipsilateral basal ganglia and thalamus, brain stem and contralateral cerebellum. Ictal brain SPECT is non-invasive, cost effective and highly sensitive for localization of epileptic focus in patients with intractable CPE. (author)

Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery

DEFF Research Database (Denmark)

Vedel, Anne G.; Holmgaard, Frederik; Rasmussen, Lars Simon

2016-01-01

Background: Debilitating brain injury occurs in 1.6–5 % of patients undergoing cardiac surgery with cardiopulmonary bypass. Diffusion-weighted magnetic resonance imaging studies have reported stroke-like lesions in up to 51 % of patients after cardiac surgery. The majority of the lesions seem...... to be caused by emboli, but inadequate blood flow caused by other mechanisms may increase ischaemia in the penumbra or cause watershed infarcts. During cardiopulmonary bypass, blood pressure can be below the lower limit of cerebral autoregulation. Although much debated, the constant blood flow provided...... by the cardiopulmonary bypass system is still considered by many as appropriate to avoid cerebral ischaemia despite the low blood pressure. Methods/design: The Perfusion Pressure Cerebral Infarct trial is a single-centre superiority trial with a blinded outcome assessment. The trial is randomising 210 patients...

Cerebral atrophic and degenerative changes following various cerebral diseases, (1)

International Nuclear Information System (INIS)

Kino, Masao; Anno, Izumi; Yano, Yuhiko; Anno, Yasuro.

1980-01-01

Patients having cerebral atrophic and degenerative changes following hypoglycemia, cerebral contusion, or cerebral hypoxia including cerebrovascular disorders were reported. Description was made as to cerebral changes visualized on CT images and clinical courses of a patient who revived 10 minutes after heart stoppage during neurosurgery, a newborn with asphyxia, a patient with hypoglycemia, a patient who suffered from asphyxia by an accident 10 years before, a patient with carbon monoxide poisoning at an acute stage, a patient who had carbon monoxide poisoning 10 years before, a patient with diffuse cerebral ischemic changes, a patient with cerebral edema around metastatic tumor, a patient with respiration brain, a patient with neurological sequelae after cerebral contusion, a patient who had an operation to excise right parietal lobe artery malformation, and a patient who was shooted by a machine gun and had a lead in the brain for 34 years. (Tsunoda, M.)

Comparison of cryogenic low-pass filters

Science.gov (United States)

Thalmann, M.; Pernau, H.-F.; Strunk, C.; Scheer, E.; Pietsch, T.

2017-11-01

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

Comparison of cryogenic low-pass filters.

Science.gov (United States)

Thalmann, M; Pernau, H-F; Strunk, C; Scheer, E; Pietsch, T

2017-11-01

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

Non-invasive diagnosis in cerebral ischemia by means of magnetic resonance imaging and near-infrared spectroscopy

International Nuclear Information System (INIS)

Piepgras, A.; Gueckel, F.; Laemmler, B.; Weigel, R.; Schmiedek, P.

1994-01-01

We describe the non-invasive assessment of cerebrovascular reserve capacity by means of near-infrared spectroscopy (NIRS) and magnetic resonance imaging. Both methods are compared with transcranial Doppler sonography. There is a good correlation of the three methods in the changes in cerebral oxygen saturation and in blood velocity following acetazolamide stimulation of cerebral blood flow, except found in one patient with unilateral carotid artery occlusion. In this patient we found a decreased cerebrovascular reserve capacity, revealed by a magnetic resonance technique designed to quantify CBV and CBF. We postulate a raised oxygen extraction as raised oxygen extraction as the cause of his changes in oxygen saturation. (orig.) [de

Pulse propagation in a two-pass optical amplifier with arbitrary laser beams overlap

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AH Farahbod

2011-09-01

Full Text Available An analytical model for two-pass optical amplifier with arbitrary beams overlap has been developed which generalized the classical theory of Frantz-Nodvik for single pass amplifier. The effect of counterpropagating beams on gain and output energy fluence included in the model. Moreover, the appropriate limiting relations for two special cases of weak input signal and saturation state of the amplifier gain have been derived. The results indicate that for complete beams overlap, the gain and output energy have the least values. The model predictions are consistent with experimental observations and exact analytical model for two-pass amplifier when beam propagation paths are coincided.

Detection of cerebral hemorrhage in rabbits by time-difference magnetic inductive phase shift spectroscopy.

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Wencai Pan

Full Text Available Cerebral hemorrhage, a difficult issue in clinical practice, is often detected and studied with computed tomography (CT, magnetic resonance imaging (MRI, and positron emission tomography (PET. However, these expensive devices are not readily available in economically underdeveloped regions, and hence are unable to provide bedside and emergency on-site monitoring. The magnetic inductive phase shift (MIPS is an emerging technology that may become a new tool to detect cerebral hemorrhage and to serve as an inexpensive partial substitute to medical imaging. In order to study a wider band of cerebral hemorrhage MIPS and to provide more useful information for measuring cerebral hemorrhage, we established a cerebral hemorrhage magnetic induction phase shift spectroscopy (MIPSS detection system. Thirteen rabbits with five cerebral hemorrhage states were studied using a single coil-coil within a 1 MHz-200 MHz frequency range in linear sweep. A feature band (FB with the highest detection sensitivity and the greatest stability was selected for further analysis and processing. In addition, a maximum conductivity cerebrospinal fluid (CSF MRI was performed to verify and interpret the MIPSS result. The average phase shift change induced by a 3 ml injection of autologous blood under FB was -7.7503° ± 1.4204°, which was considerably larger than our previous work. Data analysis with a non-parametric statistical Friedman M test showed that in the FB, MIPSS could distinguish the five states of cerebral hemorrhage in rabbits, with a statistical significance of p<0.05. A B-F distribution profile was designed according to the MIPSS under FB that can provide instantaneous diagnostic information about the cerebral hemorrhage severity from a single set of measurements. The results illustrate that the MIPSS detection method is able to provide a new possibility for real-time monitoring and diagnosis of the severity of cerebral hemorrhage.

Determining the Optimal Number of Core Needle Biopsy Passes for Molecular Diagnostics.

Science.gov (United States)

Hoang, Nam S; Ge, Benjamin H; Pan, Lorraine Y; Ozawa, Michael G; Kong, Christina S; Louie, John D; Shah, Rajesh P

2018-03-01

The number of core biopsy passes required for adequate next-generation sequencing is impacted by needle cut, needle gauge, and the type of tissue involved. This study evaluates diagnostic adequacy of core needle lung biopsies based on number of passes and provides guidelines for other tissues based on simulated biopsies in ex vivo porcine organ tissues. The rate of diagnostic adequacy for pathology and molecular testing from lung biopsy procedures was measured for eight operators pre-implementation (September 2012-October 2013) and post-implementation (December 2013-April 2014) of a standard protocol using 20-gauge side-cut needles for ten core biopsy passes at a single academic hospital. Biopsy pass volume was then estimated in ex vivo porcine muscle, liver, and kidney using side-cut devices at 16, 18, and 20 gauge and end-cut devices at 16 and 18 gauge to estimate minimum number of passes required for adequate molecular testing. Molecular diagnostic adequacy increased from 69% (pre-implementation period) to 92% (post-implementation period) (p < 0.001) for lung biopsies. In porcine models, both 16-gauge end-cut and side-cut devices require one pass to reach the validated volume threshold to ensure 99% adequacy for molecular characterization, while 18- and 20-gauge devices require 2-5 passes depending on needle cut and tissue type. Use of 20-gauge side-cut core biopsy needles requires a significant number of passes to ensure diagnostic adequacy for molecular testing across all tissue types. To ensure diagnostic adequacy for molecular testing, 16- and 18-gauge needles require markedly fewer passes.

Cerebral microbleeds in a neonatal rat model.

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Brianna Carusillo Theriault

Full Text Available In adult humans, cerebral microbleeds play important roles in neurodegenerative diseases but in neonates, the consequences of cerebral microbleeds are unknown. In rats, a single pro-angiogenic stimulus in utero predisposes to cerebral microbleeds after birth at term, a time when late oligodendrocyte progenitors (pre-oligodendrocytes dominate in the rat brain. We hypothesized that two independent pro-angiogenic stimuli in utero would be associated with a high likelihood of perinatal microbleeds that would be severely damaging to white matter.Pregnant Wistar rats were subjected to intrauterine ischemia (IUI and low-dose maternal lipopolysaccharide (mLPS at embryonic day (E 19. Pups were born vaginally or abdominally at E21-22. Brains were evaluated for angiogenic markers, microhemorrhages, myelination and axonal development. Neurological function was assessed out to 6 weeks.mRNA (Vegf, Cd31, Mmp2, Mmp9, Timp1, Timp2 and protein (CD31, MMP2, MMP9 for angiogenic markers, in situ proteolytic activity, and collagen IV immunoreactivity were altered, consistent with an angiogenic response. Vaginally delivered pups exposed to prenatal IUI+mLPS had spontaneous cerebral microbleeds, abnormal neurological function, and dysmorphic, hypomyelinated white matter and axonopathy. Pups exposed to the same pro-angiogenic stimuli in utero but delivered abdominally had minimal cerebral microbleeds, preserved myelination and axonal development, and neurological function similar to naïve controls.In rats, pro-angiogenic stimuli in utero can predispose to vascular fragility and lead to cerebral microbleeds. The study of microbleeds in the neonatal rat brain at full gestation may give insights into the consequences of microbleeds in human preterm infants during critical periods of white matter development.

Detection of Cerebral Hemorrhage in Rabbits by Time-Difference Magnetic Inductive Phase Shift Spectroscopy

Science.gov (United States)

Pan, Wencai; Yan, Qingguang; Qin, Mingxin; Jin, Gui; Sun, Jian; Ning, Xu; Zhuang, Wei; Peng, Bin; Li, Gen

2015-01-01

Cerebral hemorrhage, a difficult issue in clinical practice, is often detected and studied with computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). However, these expensive devices are not readily available in economically underdeveloped regions, and hence are unable to provide bedside and emergency on-site monitoring. The magnetic inductive phase shift (MIPS) is an emerging technology that may become a new tool to detect cerebral hemorrhage and to serve as an inexpensive partial substitute to medical imaging. In order to study a wider band of cerebral hemorrhage MIPS and to provide more useful information for measuring cerebral hemorrhage, we established a cerebral hemorrhage magnetic induction phase shift spectroscopy (MIPSS) detection system. Thirteen rabbits with five cerebral hemorrhage states were studied using a single coil-coil within a 1 MHz-200 MHz frequency range in linear sweep. A feature band (FB) with the highest detection sensitivity and the greatest stability was selected for further analysis and processing. In addition, a maximum conductivity cerebrospinal fluid (CSF) MRI was performed to verify and interpret the MIPSS result. The average phase shift change induced by a 3 ml injection of autologous blood under FB was -7.7503° ± 1.4204°, which was considerably larger than our previous work. Data analysis with a non-parametric statistical Friedman M test showed that in the FB, MIPSS could distinguish the five states of cerebral hemorrhage in rabbits, with a statistical significance of phemorrhage severity from a single set of measurements. The results illustrate that the MIPSS detection method is able to provide a new possibility for real-time monitoring and diagnosis of the severity of cerebral hemorrhage. PMID:26001112

Land subsidence caused by a single water extraction well and rapid water infiltration

Directory of Open Access Journals (Sweden)

I. Martinez-Noguez

2015-11-01

Full Text Available Nowadays several parts of the world suffer from land subsidence. This setting of the earth surface occurs due to different factors such as earth quakes, mining activities, and gas, oil and water withdrawal. This research presents a numerical study of the influence of land subsidence caused by a single water extraction well and rapid water infiltration into structural soil discontinuities. The numerical simulation of the infiltration was based on a two-phase flow-model for porous media, and for the deformation a Mohr–Coulomb model was used. A two-layered system with a fault zone is presented. First a single water extraction well is simulated producing a cone-shaped (conical water level depletion, which can cause land subsidence. Land Subsidence can be further increased if a hydrological barrier as a result of a discontinuity, exists. After water extraction a water column is applied on the top boundary for one hours in order to represent a strong storm which produces rapid water infiltration through the discontinuity as well as soil deformation. Both events are analysed and compared in order to characterize deformation of both elements and to get a better understanding of the land subsidence and new fracture formations.

Single-photon tomographic determination of regional cerebral blood flow in psychiatric disorders

International Nuclear Information System (INIS)

Devous, M.D. Sr.; Rush, A.J.; Schlesser, M.A.; Debus, J.; Raese, J.D.; Chehabi, H.H.; Bonte, F.J.

1984-01-01

Regional cerebral blood flow (rCBF) was measured by single-photon emission computed tomography (SPECT) of 133-Xe washout in 29 normal volunteers, 22 unipolar endogenous depressives (UPE), 9 unipolar nonendogenous depressives (UPNE), 13 bipolar depressed patients (BPD), and 14 schizophrenic patients (SCHZ). RCBF was measured 2 and 6 cm above and parallel to the cantho-meatal line and quantitated in 14 gray matter regions. Most subjects were drug-free for 4-14 days. Diagnoses were made by experienced clinicians employing the Research Diagnostic Criteria, the Hamilton Rating Scale, and the dexamethasone suppression test. SCHZ were rated with the Brief Psychiatric Rating Scale. UPE had reduced flow compared to normals in the right parietal and temporal lobes and a nonsignificant trend toward left temporal flow reductions. UPNE were not different from normal or other patient groups. BPD had significant flow elevations in the left hemisphere relative to normal, and in both hemispheres relative to UPE. SCHZ were not significantly different from normal or other patient groups. Anterior-posterior flow shifts were evaluated by subtracting parietal or temporal flows from frontal flows. SCHZ demonstrated a greater posterior shift (lower relative frontal lobe flow) in comparison to both UPE and UPNE. The most significant regional flow abnormalities were observed as frontal flow reductions in individual SCHZ, although these were not significant in the whole group in comparison to normal

CMOS-based carbon nanotube pass-transistor logic integrated circuits

Science.gov (United States)

Ding, Li; Zhang, Zhiyong; Liang, Shibo; Pei, Tian; Wang, Sheng; Li, Yan; Zhou, Weiwei; Liu, Jie; Peng, Lian-Mao

2012-01-01

Field-effect transistors based on carbon nanotubes have been shown to be faster and less energy consuming than their silicon counterparts. However, ensuring these advantages are maintained for integrated circuits is a challenge. Here we demonstrate that a significant reduction in the use of field-effect transistors can be achieved by constructing carbon nanotube-based integrated circuits based on a pass-transistor logic configuration, rather than a complementary metal-oxide semiconductor configuration. Logic gates are constructed on individual carbon nanotubes via a doping-free approach and with a single power supply at voltages as low as 0.4 V. The pass-transistor logic configurarion provides a significant simplification of the carbon nanotube-based circuit design, a higher potential circuit speed and a significant reduction in power consumption. In particular, a full adder, which requires a total of 28 field-effect transistors to construct in the usual complementary metal-oxide semiconductor circuit, uses only three pairs of n- and p-field-effect transistors in the pass-transistor logic configuration. PMID:22334080

Subcortical aphasia and cerebral blood flow using SPECT

International Nuclear Information System (INIS)

Celsis, P.; Puel, M.; Demonet, J.P.; Bonafe, A.; Cardebat, D.; Viallard, G.; Pujol, T.; Marc-Vergnes, J.P.; Rascol, A.

1985-01-01

Possible cerebral blood flow (CBF) alteration in subcortical aphasia was investigated by single-photon emission tomography (SPECT). The results confirm the capsulo-striatal lesions and also point to the high rate of ipsilateral thalamic and cortical dysfunction. (author). 8 refs.; 1 fig.; 1 tab

Extensive intestinal first-pass metabolism of arctigenin: evidenced by simultaneous monitoring of both parent drug and its major metabolites.

Science.gov (United States)

Gao, Qiong; Zhang, Yufeng; Wo, Siukwan; Zuo, Zhong

2014-03-01

The current study aims to investigate intestinal absorption and metabolism of arctigenin (AR) through simultaneous monitoring of AR and its major metabolites in rat plasma. An UPLC/MS/MS assay was developed with chromatographic separation of all analytes achieved by a C18 Column (3.9mm×150mm, 3.5μm) and a gradient elution with acetonitrile and 0.1% formic acid within 9min. Sample extraction with acetonitrile was optimized to achieve satisfactory recovery for both AR and its major metabolites. The lower limit of quantification (LLOQ) for all analytes was 25ng/ml. The intra-day and inter-day precision and accuracy of each analyte at LLOQ and three quality control (QC) concentrations (low, middle and high) in rat plasma was within 15.0% RSD and 15.0% bias. The extraction recoveries were within the range of 83.8-94.0% for all analytes. The developed and validated assay was then applied to the absorption study of AR in both Caco-2 cell monolayer model and in situ single-pass rat intestinal perfusion model. High absorption permeability of AR was demonstrated in both models with Papp of (1.76±0.48)×10(-5) (A→B) (Caco-2) and Pblood of (8.6±3.0)×10(-6)cm/s (intestinal perfusion). Extensive first-pass metabolism of AR to arctigenic acid (AA) and arctigenin-4'-O-glucuronide (AG) was identified in rat intestinal perfusion study with Cummins's extraction ratios of 0.458±0.012 and 0.085±0.013, respectively. The current assay method demonstrated to be a practical tool for pharmacokinetics investigation of AR with complicated metabolism pathways and multiple metabolites. Copyright © 2013 Elsevier B.V. All rights reserved.

Cerebral perfusion in homogeneity in normal volunteers

International Nuclear Information System (INIS)

Gruenwald, S.M.; Larcos, G.

1998-01-01

Full text: In the interpretation of cerebral perfusion scans, it is important to know the normal variation in perfusion which may occur between the cerebral hemispheres. For this reason 24 normal volunteers with no neurological or psychiatric history, and who were on no medications, had 99m Tc-HMPAO brain SPECT studies using a single headed gamma camera computer system. Oblique, coronal and sagittal images were reviewed separately by two experienced observers and any differences were resolved by consensus. Semi-quantitation was performed by summing two adjacent oblique slices and drawing right and left mirror image ROIs corresponding to the mid section level of anterior and posterior frontal lobes, anterior and posterior parietal lobes, temporal lobes and cerebellum. From the mean counts per pixel, right: left ROI ratios and ROI: cerebellar ratios were calculated. On qualitative review 6/24 subjects had mild asymmetry in tracer distribution between right and left cerebral lobes. Semi-quantitation revealed a 5-10% difference in counts between right and left ROIs in 12/24 subjects and an additional three subjects had 10-20% difference in counts between right and left temporal lobes. This study demonstrates the presence of mild asymmetry of cerebral perfusion in a significant minority of normal subjects

Immediate Implant Placement in Single-Tooth Molar Extraction Sockets: A 1- to 6-Year Retrospective Clinical Study.

Science.gov (United States)

Amato, Francesco; Polara, Giorgio

The aim of this study was to investigate the survival rate of implants immediately placed in fresh extraction sockets of molars in the maxilla and mandible with a single-stage procedure. A total of 102 patients were treated, and 107 implants (53 in the maxilla and 54 in the mandible) were placed in a fresh molar extraction socket and connected to a healing abutment. After a mean follow-up of 3 years (range: 1 to 6 years) 1 implant failed, for a cumulative success rate of 99.06% (98.11% for the mandible and 100% for the maxilla). The results of this study support placement of an implant immediately after the extraction of a molar, applying a single-stage procedure.

Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia; Measurement of cerebral blood volume (CBV) with sup 99m Tc-RBC SPECT

Energy Technology Data Exchange (ETDEWEB)

Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo (Hokkaido Neurosurgical Memorial Hospital (Japan)); Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi

1990-03-01

To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with {sup 99m}Tc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by {sup 133}Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with {sup 99m}Tc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with {sup 133}Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r= -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with {sup 133}Xe SPECT and {sup 99m}Tc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease. (author).

Responses of cerebral GABA-containing CBM neuron to taste stimulation with seaweed extracts in Aplysia kurodai.

Science.gov (United States)

Narusuye, Kenji; Kinugawa, Aiko; Nagahama, Tatsumi

2005-11-01

Aplysia kurodai distributed along Japan feeds well on Ulva pertusa but rejects Gelidium amansii with distinctive patterned movements of the jaws and radula. On the ventral side of the cerebral M cluster, four cell bodies of higher order neurons that send axons to the buccal ganglia are distributed (CBM neurons). We have previously shown that the dopaminergic CBM1 modulates basic feeding circuits in the buccal ganglia for rejection by firing at higher frequency after application of the aversive taste of seaweed such as Gelidium amansii. In the present experiments immunohistochemical techniques showed that the CBM3 exhibited gamma-aminobutyric acid (GABA)-like immunoreactivity. The CBM3 may be equivalent to the CBI-3 involved in changing the motor programs from rejection to ingestion in Aplysia californica. The responses of the CBM3 to taste stimulation of the lips with seaweed extracts were investigated by the use of calcium imaging. The calcium-sensitive dye, Calcium Green-1, was iontophoretically introduced into a cell body of the CBM3 using a microelectrode. Application of Ulva pertusa or Gelidium amansii extract induced different changes in fluorescence in the CBM3 cell body, indicating that taste of Ulva pertusa initially induced longer-lasting continuous spike responses at slightly higher frequency compared with that of Gelidium amansii. Considering a role of the CBM3 in the pattern selection, these results suggest that elongation of the initial firing response may be a major factor for the CBM3 to switch the buccal motor programs from rejection to ingestion after application of different tastes of seaweeds in Aplysia kurodai. (c) 2005 Wiley Periodicals, Inc.

Immediate effects of a single session of robot-assisted gait training using Hybrid Assistive Limb (HAL) for cerebral palsy.

Science.gov (United States)

Matsuda, Mayumi; Mataki, Yuki; Mutsuzaki, Hirotaka; Yoshikawa, Kenichi; Takahashi, Kazushi; Enomoto, Keiko; Sano, Kumiko; Mizukami, Masafumi; Tomita, Kazuhide; Ohguro, Haruka; Iwasaki, Nobuaki

2018-02-01

[Purpose] Robot-assisted gait training (RAGT) using Hybrid Assistive Limb (HAL, CYBERDYNE) was previously reported beneficial for stroke and spinal cord injury patients. Here, we investigate the immediate effect of a single session of RAGT using HAL on gait function for cerebral palsy (CP) patients. [Subjects and Methods] Twelve patients (average age: 16.2 ± 7.3 years) with CP received a single session of RAGT using HAL. Gait speed, step length, cadence, single-leg support per gait cycle, hip and knee joint angle in stance, and swing phase per gait cycle were assessed before, during, and immediately after HAL intervention. [Results] Compared to baseline values, single-leg support per gait cycle (64.5 ± 15.8% to 69.3 ± 12.1%), hip extension angle in mid-stance (149.2 ± 19.0° to 155.5 ± 20.1°), and knee extension angle in mid-stance (137.6 ± 20.2° to 143.1 ± 19.5°) were significantly increased immediately after intervention. Further, the knee flexion angle in mid-swing was significantly decreased immediately after treatment (112.0 ± 15.5° to 105.2 ± 17.1°). Hip flexion angle in mid-swing also decreased following intervention (137.2 ± 14.6° to 129.7 ± 16.6°), but not significantly. Conversely, gait speed, step length, and cadence were unchanged after intervention. [Conclusion] A single-time RAGT with HAL improved single-leg support per gait cycle and hip and knee joint angle during gait, therapeutically improving gait function in CP patients.

Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments.

Science.gov (United States)

Wang, Guohui; Um, Wooyong; Wang, Zheming; Reinoso-Maset, Estela; Washton, Nancy M; Mueller, Karl T; Perdrial, Nicolas; O'Day, Peggy A; Chorover, Jon

2017-10-03

The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford's cribs (Hanford, WA). During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO 2 )(PO 4 )·3H 2 O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K 2 (UO 2 ) 6 O 4 (OH) 6 ·7H 2 O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitated as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67 × 10 -12 mol g -1 s -1 . In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42 × 10 -10 mol g -1 s -1 . The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for the prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.

Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments

Energy Technology Data Exchange (ETDEWEB)

Wang, Guohui [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Um, Wooyong [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Pohang University of Science and Technology (POSTECH), Pohang, South Korea; Wang, Zheming [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Reinoso-Maset, Estela [Sierra; Washton, Nancy M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Mueller, Karl T. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Perdrial, Nicolas [Department; Department; O’Day, Peggy A. [Sierra; Chorover, Jon [Department

2017-09-21

The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford’s cribs, USA. During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO2)(PO4)·3H2O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K2(UO2)6O4(OH)6·7H2O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitated as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67E-12 mol g-1 s-1. In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42E-10 mol g-1 s-1. The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.

Single-pass continuous-flow leach test of PNL 76-68 glass: some selected Bead Leach I results

International Nuclear Information System (INIS)

Coles, D.G.

1981-01-01

A single-pass continuous-flow leach test of PNL 76-68 glass beads (7 mm dia) was concluded after 420 days of uninterrupted operation. Variables included in the experimental matrix were flow-rate, leachant composition, and temperature. Analysis was conducted on all leachate samples for 237 Np and 239 Pu as well as a number of nonradioactive elements. Results indicated that flow-rate and leachant systematically affected the leach rate, but only slightly. Temperature effects were significant. Plutonium leach rate was lower at higher temperature suggesting that Pu sorption onto the beads was enhanced at the higher temperature. The range of leach rates for all analyzed elements (except Pu), at both temperatures, at all three flow rates, and with all three leachant compositions varied over only three orders of magnitude. The range of variables used in this experiment covered those expected in many proposed repository environments. The preliminary interpretation of the results aPPh 3 also reacted with Mn 2 (CO) 10 and Cp 2 Mo 2 (CO) 6 to give a variety of products at room temperature. A radical mechanism was suggested

Standard practice for measurement of the glass dissolution rate using the single-pass flow-through test method

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This practice describes a single-pass flow-through (SPFT) test method that can be used to measure the dissolution rate of a homogeneous silicate glass, including nuclear waste glasses, in various test solutions at temperatures less than 100°C. Tests may be conducted under conditions in which the effects from dissolved species on the dissolution rate are minimized to measure the forward dissolution rate at specific values of temperature and pH, or to measure the dependence of the dissolution rate on the concentrations of various solute species. 1.2 Tests are conducted by pumping solutions in either a continuous or pulsed flow mode through a reaction cell that contains the test specimen. Tests must be conducted at several solution flow rates to evaluate the effect of the flow rate on the glass dissolution rate. 1.3 This practice excludes static test methods in which flow is simulated by manually removing solution from the reaction cell and replacing it with fresh solution. 1.4 Tests may be conducted wit...

The MM-CGI Cerebral Palsy: modification and pretesting of an instrument to measure anticipatory grief in parents whose child has cerebral palsy.

Science.gov (United States)

Al-Gamal, Ekhlas; Long, Tony

2014-07-01

To establish the potential of a modified version of the MM-CGI Childhood Cancer to assess anticipatory grief in parents of children with cerebral palsy, to amend the existing scale for use with the specific patient group, to test the psychometric properties of the modified version (MM-CGI Cerebral Palsy) and to review the clinical potential of the new scale. Parents of children with cerebral palsy may experience reactions similar to parents of children with other enduring or life-limiting conditions, and anticipatory grief may be one such psychological reaction. While the burden of caring is sometimes balanced by positive perceptions of the child, which enhance coping ability, for many parents the outcome is damage to their physical and mental health and impaired family functioning. A cross-sectional, descriptive, correlational design. The MM-CGI Cerebral Palsy was administered in structured interviews with 204 parents. Standardised measures of caregivers' depression, stress and perceived social support were also administered. Mothers and fathers were recruited from healthcare centres and schools for special education. Cronbach's alpha was used to assess internal consistency, and Pearson's product-moment correlation was used to assess construct validity. The subscales were each found to measure a single dimension of anticipatory grief, and significant correlations were established with existing instruments. The instrument demonstrated excellent internal consistency reliability and good construct validity. The MM-CGI Cerebral Palsy could be useful for diagnosing anticipatory grief among parents of children with cerebral palsy. This preliminary work moves the programme on to testing in intervention studies. In the absence of an existing measure for the assessment of anticipatory grief, specifically in parents of children with cerebral palsy, the MM-CGI Cerebral Palsy could prove to be an effective assessment tool for clinicians and researchers. © 2013 John Wiley

TPG bus passes

CERN Multimedia

Staff Association

2013-01-01

The CERN Staff Association will stop selling TPG bus passes. All active and retired members of the CERN personnel will be able to purchase Unireso bus passes from the CERN Hostel - Building 39 (Meyrin site) from 1st February 2013. For more information: https://cds.cern.ch/journal/CERNBulletin/2013/04/Announcements/1505279?ln=en

United Cerebral Palsy

Science.gov (United States)

... your local affiliate Find your local affiliate United Cerebral Palsy United Cerebral Palsy (UCP) is a trusted resource for individuals with Cerebral Palsy and other disabilities and their networks. Individuals with ...

A Systematic Review on Effect of Single-Dose Preoperative Antibiotics at Surgical Osteotomy Extraction of Lower Third Molars

DEFF Research Database (Denmark)

Marcussen, Karoline Brørup; Laulund, Anne Sofie; Jørgensen, Henrik L

2016-01-01

PURPOSE: We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of a single dose of preoperative antibiotic administered perorally, intravenously, intramuscularly, or topically for preventing infection and alveolar osteitis in lower third molar...... that penicillin V was effective in reducing the incidence of alveolar osteitis (OR = 0.1; 95% CI, 0.03 to 0.30; P ≤ .0001). CONCLUSIONS: A single oral dose of 2 g of amoxicillin before lower third molar osteotomy surgical extraction significantly decreased the incidence of SSI. A single dose of 0.8 g...... of penicillin V before lower third molar osteotomy surgical extraction significantly decreased the incidence of alveolar osteitis....

Improvements in SPECT technology for cerebral imaging

International Nuclear Information System (INIS)

Esser, P.D.

1985-01-01

Advancement in three major areas of SPECT (single photon emission computed tomography) technology have resulted in improved image quality for cerebral studies. In the first area, single-crystal camera electronics, extensive use of microprocessors, custom digital circuitry, an data bus architecture have allowed precise external control of all gantry motions and improved signal processing. The new digital circuitry permits energy, uniformity, and linearity corrections to be an integral part of the processing electronics. Calibration of these correlations is controlled by algorithms stored in the camera's memory. The second area of improved SPECT technology is camera collimation and related imaging techniques. In this area, system resolution has been improved without loss of sensitivity by decreasing the air gap between patient and collimator surface. Since cerebral studies characteristically image high-contrast regions less than 1 cm in size, image quality has been improved by increasing collimator resolution even at the expense of sensitivity. Increased resolution also improved image contrast for studies using 123 I-labeled pharmaceuticals with 3% to 4% 124 I contamination. 65 references

How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

Directory of Open Access Journals (Sweden)

Andreas Habertheuer

2015-01-01

Full Text Available Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP and retrograde cerebral perfusion (RCP. Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data.

How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

Science.gov (United States)

Habertheuer, Andreas; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther; Vallabhajosyula, Prashanth

2015-01-01

Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA) or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data. PMID:26713319

Histopathologically verified cerebral CT findings in AIDS

International Nuclear Information System (INIS)

Tosch, U.; Witt, H.; Iglesias-Rozas, J.R.; Ruf, B.

1990-01-01

Computer tomographic and histopathological findings in 55 patients who died of the complications of acquired immunodeficiency syndrome, were reviewed retrospectively. In 23 patients (42%) an increased space of the internal or external cerebral spinal fluid was diagnosed. 20 patients (36%) had focal lesions. We differentiated between single, multiple and ring-shaped lesions with contrast enhancement and hypodense lesions. In 12 cases (22%) no CT abnormalities were found. Focal lesions proved to be secondary to toxoplasmosis in 85%. Single lesions were never caused by toxoplasmosis. (orig.) [de

Clinical implication and prognosis of normal baseline cerebral blood flow with impaired vascular reserve in patients with major cerebral artery occlusive disease

International Nuclear Information System (INIS)

Isozaki, Makoto; Arai, Yoshikazu; Kubota, Toshihiko; Kikuta, Ken-ichiro; Kudo, Takashi; Kiyono, Yasushi; Kobayashi, Masato; Okazawa, Hidehiko

2010-01-01

To investigate the prognosis of patients with cerebrovascular steno-occlusive disease who have preserved baseline cerebral blood flow (CBF) and reduced cerebral vasoreactivity (CVR), they were followed up after scans of positron emission tomography (PET). Fifty-seven patients with symptomatic unilateral major cerebral arterial occlusion or severe stenosis underwent O-15 gas and water PET scans to measure cerebral blood volume, metabolic rate of oxygen, oxygen extraction fraction (OEF), and CBF at the baseline and after acetazolamide administration. Thirty of them (mean age 60±10 years) had normal ipsilateral CBF, and were followed prospectively at least 30 months from the last ischemic event. They were medically treated for cerebral circulation and underlying diseases during follow-up periods. The primary endpoint was determined as stroke recurrence during the follow-up. Thirty patients were divided into two groups of reduced CVR (N=16, 63±8 years) and normal CVR (N=14, 56±10 years) on the basis of CVR values from healthy volunteers. None of them showed significant laterality in baseline CBF and OEF between the hemispheres although patients with reduced CVR showed a tendency of ipsilateral increases in OEF and CBV. Patients were followed up for 50.5±19.0 and 48.1±12.4 months in the reduced and normal CVR groups, respectively. Although one patient with reduced CVR died of heart disease, there was no incidence of ischemic events during follow-up periods for either group. In the present prospective study, patients with sufficient baseline CBF showed good prognosis and no difference in recurrent stroke risks even though they had poor CVR in the affected hemisphere, indicating that these patients can be treated by medication for cerebral circulation and baseline diseases if they have high risk factors for neurosurgical treatment. (author)

WebPASS Explorer (HR Personnel Management)

Data.gov (United States)

US Agency for International Development — WebPass Explorer (WebPASS Framework): USAID is partnering with DoS in the implementation of their WebPass Post Personnel (PS) Module. WebPassPS does not replace...

Regional cerebral blood flow analysis of vascular dementia by the single photon emission computed tomography

International Nuclear Information System (INIS)

Miyakawa, Kouichi; Watanabe, Sho; Suzuki, Michiyo; Kamijima, Gonbei

1989-01-01

In order to evaluate the relationship between the regional cerebral blood flow (CBF) and cerebrovascular dementia, eleven patients with vascular dementia and eight patients with non-demented infarction were studied and regional CBF were measured quantitatively with single photon emission computed tomography (SPECT) by using N-isopropyl-p-(I-123) iodoamphetamine. All cases were basal infarction and vascular dementia were diagnosed by less than 21.5 of the Hasegawa's dementia score and more than 7 of Hachinsk's ischemic score. The results of the present study were as follows: (1) Cerebrovascular dementia showed lower mean CBF value compared with non-demented group. (2) Regional CBF of bilateral frontal areas and affected basal ganglia were significantly reduced than occipital area in the dementia group. (3) A comparison of regional CBF and the Hasegawa's dementia score revealed a statistically significant correlation at the bilateral frontal areas in the dementia group. It is possible that measuring the regional CBF quantitatively by IMP-SPECT is useful for clinical analysis of vascular dementia. (author)

Malaria cerebral Cerebral malaria

Directory of Open Access Journals (Sweden)

Carlos Hugo Zapata Zapata

2003-03-01

Full Text Available La malaria Cerebral (MC es la complicación más frecuente de la malaria por P. falciparum; aproximadamente el 90% de las personas que la han padecido se recuperan completamente sin secuelas neurológicas. Aún no se conoce con claridad su patogénesis pero se han postulado cuatro hipótesis o mecanismos posibles: 1 citoadherencia y secuestro de glóbulos rojos parasitados en la microvasculatura cerebral; 2 formación de rosetas y aglutinación de glóbulos rojos parasitados; 3 producción de citoquinas y activación de segundos mensajeros y, 4 apertura de la barrera hematoencefálica. Sin embargo, queda un interrogante sin resolver aún: ¿qué proceso se lleva a cabo para que el parásito, desde el espacio microvascular, pueda interferir transitoriamente con la función cerebral? Recientemente se ha utilizado el precursor de la proteína b-Amiloide como un marcador de daño neuronal en MC; este precursor será de gran ayuda en futuras investigaciones realizadas en nuestro medio que aporten información para comprender la patogénesis de la MC. Is the most common complication of P. falciparum malaria; nearly 90% of people who have suffered CM can recover without neurological problems. Currently there are four hypotheses that explain pathogenesis of CM: cytoadherence and sequestering of parasitized red blood cells to cerebral capillaries; rosette formation and parasitized red blood cells agglutination; production of cytokines and activation of second messengers and opening of the blood-brain barrier. However the main question remains to be answered; how the host-parasite interaction in the vascular space interferes transiently with cerebral function? Recently, the beta amyloid precursor peptide has been employed as marker of neural injury in CM. It is expected that the beta amyloid precursor peptide will help to understand the pathogenesis of CM in complicated patients of endemic areas of Colombia.

Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

Science.gov (United States)

Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

2016-01-01

Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture.

Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Emanuela Ventrella

Full Text Available Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture.

Regional cerebral blood flow measurement in brain tumors

International Nuclear Information System (INIS)

Izunaga, Hiroshi; Hirota, Yoshihisa; Takahashi, Mutsumasa; Fuwa, Isao; Kodama, Takafumi; Matsukado, Yasuhiko

1986-01-01

The regional cerebral blood flow (CBF) was determined on seventeen patients with brain tumors. Ring type single photon emission CT (SPECT) was used following intravenous injection of 133 Xe. Case materials included eleven meningiomas and six malignant gliomas. Evaluation was performed with emphasis on the following points; 1. Correlation of the flow data within tumors to the angiographic tumor stains, 2. Influence of tumors on the cerebral blood flow of the normal brain tissue, 3. Correlation between degree of peripheral edema and the flow data of the affected hemispheres. There was significant correlation between flow data within tumors and angiographic tumor stains in meningiomas. Influence of tumors on cerebral blood flow of the normal tissue was greater in meningiomas than in gliomas. There was negative correlation between the degree of peripheral edema and the flow data of the affected hemisphere. It has been concluded that the measurement of CBF in brain tumors is a valuable method in evaluation of brain tumors. (author)

Regional cerebral blood flow measurement in brain tumors

Energy Technology Data Exchange (ETDEWEB)

Izunaga, Hiroshi; Hirota, Yoshihisa; Takahashi, Mutsumasa; Fuwa, Isao; Kodama, Takafumi; Matsukado, Yasuhiko

1986-10-01

The regional cerebral blood flow (CBF) was determined on seventeen patients with brain tumors. Ring type single photon emission CT (SPECT) was used following intravenous injection of /sup 133/Xe. Case materials included eleven meningiomas and six malignant gliomas. Evaluation was performed with emphasis on the following points; 1. Correlation of the flow data within tumors to the angiographic tumor stains, 2. Influence of tumors on the cerebral blood flow of the normal brain tissue, 3. Correlation between degree of peripheral edema and the flow data of the affected hemispheres. There was significant correlation between flow data within tumors and angiographic tumor stains in meningiomas. Influence of tumors on cerebral blood flow of the normal tissue was greater in meningiomas than in gliomas. There was negative correlation between the degree of peripheral edema and the flow data of the affected hemisphere. It has been concluded that the measurement of CBF in brain tumors is a valuable method in evaluation of brain tumors.

Designed optimization of a single-step extraction of fucose-containing sulfated polysaccharides from Sargassum sp

DEFF Research Database (Denmark)

Ale, Marcel Tutor; Mikkelsen, Jørn Dalgaard; Meyer, Anne S.

2012-01-01

Fucose-containing sulfated polysaccharides can be extracted from the brown seaweed, Sargassum sp. It has been reported that fucose-rich sulfated polysaccharides from brown seaweeds exert different beneficial biological activities including anti-inflammatory, anticoagulant, and anti-viral effects....... Classical extraction of fucose-containing sulfated polysaccharides from brown seaweed species typically involves extended, multiple-step, hot acid, or CaCl2 treatments, each step lasting several hours. In this work, we systematically examined the influence of acid concentration (HCl), time, and temperature...... on the yield of fucosecontaining sulfated polysaccharides (FCSPs) in statistically designed two-step and single-step multifactorial extraction experiments. All extraction factors had significant effects on the fucose-containing sulfated polysaccharides yield, with the temperature and time exerting positive...

Cerebral hypometabolism in progressive supranuclear palsy studied with positron emission tomography

International Nuclear Information System (INIS)

Foster, N.L.; Gilman, S.; Berent, S.; Morin, E.M.; Brown, M.B.; Koeppe, R.A.

1988-01-01

Progressive supranuclear palsy (PSP) is characterized by supranuclear palsy of gaze, axial dystonia, bradykinesia, rigidity, and a progressive dementia. Pathological changes in this disorder are generally restricted to subcortical structures, yet the type and range of cognitive deficits suggest the involvement of many cerebral regions. We examined the extent of functional impairment to cerebral cortical and subcortical structures as measured by the level of glucose metabolic activity at rest. Fourteen patients with PSP were compared to 21 normal volunteers of similar age using 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose metabolism was reduced in the caudate nucleus, putamen, thalamus, pons, and cerebral cortex, but not in the cerebellum in the patients with PSP as compared to the normal subjects. Analysis of individual brain regions revealed significant declines in cerebral glucose utilization in most regions throughout the cerebral cortex, particularly those in the superior half of the frontal lobe. Declines in the most affected regions of cerebral cortex were greater than those in any single subcortical structure. Although using conventional neuropathological techniques the cerebral cortex appears to be unaffected in PSP, significant and pervasive functional impairments in both cortical and subcortical structures are present. These observations help to account for the constellation of cognitive symptoms in individual patients with PSP and the difficulty encountered in identifying a characteristic psychometric profile for this group of patients

The Association Between Maternal Age and Cerebral Palsy Risk Factors.

Science.gov (United States)

Schneider, Rilla E; Ng, Pamela; Zhang, Xun; Andersen, John; Buckley, David; Fehlings, Darcy; Kirton, Adam; Wood, Ellen; van Rensburg, Esias; Shevell, Michael I; Oskoui, Maryam

2018-05-01

Advanced maternal age is associated with higher frequencies of antenatal and perinatal conditions, as well as a higher risk of cerebral palsy in offspring. We explore the association between maternal age and specific cerebral palsy risk factors. Data were extracted from the Canadian Cerebral Palsy Registry. Maternal age was categorized as ≥35 years of age and less than 20 years of age at the time of birth. Chi-square and multivariate logistic regressions were performed to calculate odds ratios and their 95% confidence intervals. The final sample consisted of 1391 children with cerebral palsy, with 19% of children having mothers aged 35 or older and 4% of children having mothers below the age of 20. Univariate analyses showed that mothers aged 35 or older were more likely to have gestational diabetes (odds ratio 1.9, 95% confidence interval 1.3 to 2.8), to have a history of miscarriage (odds ratio 1.8, 95% confidence interval 1.3 to 2.4), to have undergone fertility treatments (odds ratio 2.4, 95% confidence interval 1.5 to 3.9), and to have delivered by Caesarean section (odds ratio 1.6, 95% confidence interval 1.2 to 2.2). These findings were supported by multivariate analyses. Children with mothers below the age of 20 were more likely to have a congenital malformation (odds ratio 2.4, 95% confidence interval 1.4 to 4.2), which is also supported by multivariate analysis. The risk factor profiles of children with cerebral palsy vary by maternal age. Future studies are warranted to further our understanding of the compound causal pathways leading to cerebral palsy and the observed greater prevalence of cerebral palsy with increasing maternal age. Copyright © 2018 Elsevier Inc. All rights reserved.

Functional cerebral lateralization and dual-task efficiency-testing the function of human brain lateralization using fTCD

NARCIS (Netherlands)

Lust, J. M.; Geuze, R. H.; Groothuis, A. G. G.; Bouma, A.; Bouma, J.M.

2011-01-01

It has been hypothesized that functional cerebral lateralization enhances cognitive performance. Evidence was found in birds and fish. Our study aimed to test this hypothesis by analyzing the relationship between cerebral lateralization and both single-task performance and dual-task efficiency in

Cerebral Palsy (For Teens)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Teens / Cerebral Palsy What's in this ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

Local fibrinolytic therapy for patients with cerebral embolism and reversibility of cerebral ischemia in ultra-acute stage

International Nuclear Information System (INIS)

Koizumi, Takayuki

1993-01-01

The present study was undertaken to determine candidates for fibrinolytic therapy in cerebral embolism. Forty-three patients were examined by single photon emission computed tomography (SPECT) using 99m c-d, hexamethyl-propylene-amine oxime (HM-PAO) or N-isopropyl p[ 123 I]-iodoamphetamine ( 123 I-IMP) just before and after intra-arterial local fibrinolytic therapy. Regional cerebellar ratio (R/Ce) and asymmetry index (AI) were calculated just before the treatment (n=9). Quantitative analysis was performed after the treatment (n=all). SPECT images taken within 24 hours after the treatment fell into three patters: normal perfusion, hypoperfusion, and hyperperfusion. Patients showing normal perfusion pattern after complete recanalization developed no or smaller infarction on CT scans. However, patients showing either hypoperfusion or hyperperfusion developed large infarction. Regions with R/Ce ratio of 0.3 or smaller and/or AI of 1.5 or greater were irreversible, which was associated with cerebral infarction regardless of the duration of ischemia. On the other hand, regions with R/Ce of 0.5 or greater or AI of 1.2 or smaller were reversible with no association of infarction. Intra-arterial local fibrinolytic therapy seems to be helpful for patients with slight reduction of regional cerebral blood flow (i.e., R/Ce>0.5, AI 1.5). These findings indicate that SPECT is capable of determining reversibility of ischemic region, thereby contributing to better management of patients with acute cerebral embolism. (N.K.)

Microstructure evolution of pure copper during a single pass of simple shear extrusion (SSE): role of shear reversal

Energy Technology Data Exchange (ETDEWEB)

Bagherpour, E., E-mail: e.bagherpour@semnan.ac.ir [Faculty of Metallurgical and Materials Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Department of Mechanical Engineering, Doshisha University, Kyotanabe, Kyoto 610–0394 (Japan); Qods, F., E-mail: qods@semnan.ac.ir [Faculty of Metallurgical and Materials Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Ebrahimi, R., E-mail: ebrahimy@shirazu.ac.ir [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Miyamoto, H., E-mail: hmiyamot@mail.doshisha.ac.jp [Department of Mechanical Engineering, Doshisha University, Kyotanabe, Kyoto 610–0394 (Japan)

2016-06-01

In the present paper the role of shear reversal on microstructure, texture and mechanical properties of pure copper during a single pass of the simple shear extrusion (SSE) process was investigated. For SSE processing an appropriate die with a linear die profile was designed and constructed, which imposes forward shear in the first half and reverse shear in the second half channels. Electron back-scattering diffraction (EBSD), transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) were used to evaluate the microstructure of the deformed samples. The geometrical nature of this process imposes a distribution of strain results in the inhomogeneous microstructure and the hardness throughout the plane perpendicular to the extrusion direction. Strain reversal during the process results in a slight reduction in dislocation density, the hardness and mean disorientation angle of the samples, and an increase in the grain size. After a complete pass of SSE, dislocation density decreased by ~14% if compared to the middle of the process. This suggests that the dislocation annihilation occurred by the reversal of the shear strain. The simple shear textures were formed gradually and the strongest simple shear textures were observed on the middle of the SSE channel. The degree of the simple shear textures decreases with the distance from the middle plane where the shear is reversed, but the simple shear textures are still the major components after exit of the channel. Hardness variation was modeled by contributions from dislocation strengthening and grain boundary strengthening, where dislocation density is approximated by the misorientation angle of LAGBs which are regarded as dislocation cell boundaries. As a result, the hardness can be predicted successfully by the microstructural features, i.e. the low-angle boundaries, the mean misorientation angle and the fraction of high-angle grain boundaries.

Applications and diagnostic value of cerebral scintiscanning using 123I-amphetamine

International Nuclear Information System (INIS)

Eibach, E.; Feine, U.; Kaiser, W.; Diener, H.C.; Petersen, D.

1985-01-01

123 I-IMP is a new radiopharmaceutical for direct cerebral scintiscanning, characterized by its ability to cross the blood-brain barrier and its accumulation in the brain. Present clinical indications are illustrated by examples (disturbances of cerebral blood flow, epilepsy, organic psychosyndrome). Single photon emission computerized tomography (SPECT) permits imaging in three planes (cantho-meatal, frontal, sagittal), although it lacks the morphological quality of TCT or NMR images. The new substance may open up new perspectives in neurophysiology and neuropharmacology. (orig.) [de

Effect of adrenomedullin on the cerebral circulation: relevance to primary headache disorders

DEFF Research Database (Denmark)

Petersen, K A; Birk, S; Kitamura, K

2009-01-01

Adrenomedullin (ADM) is closely related to calcitonin gene-related peptide, which has a known causative role in migraine. Animal studies have strongly suggested that ADM has a vasodilatory effect within the cerebral circulation. For these reasons, ADM is also likely to be involved in migraine....... However, the hypothetical migraine-inducing property and effect on human cerebral circulation of ADM have not previously been investigated. Human ADM (0.08 microg kg(-1) min(-1)) or placebo (saline 0.9%) was administered as a 20-min intravenous infusion to 12 patients suffering from migraine without aura...... in a crossover double-blind study. The occurrence of headache and associated symptoms were registered regularly 24 h post infusion. Cerebral blood flow (CBF) was measured by (133)Xenon single-photon emission computed tomography, mean blood flow velocity in the middle cerebral artery (V(MCA)) by transcranial...

"Which pass is better?" Novel approaches to assess passing effectiveness in elite soccer.

Science.gov (United States)

Rein, Robert; Raabe, Dominik; Memmert, Daniel

2017-10-01

Passing behaviour is a key property of successful performance in team sports. Previous investigations however have mainly focused on notational measurements like total passing frequencies which provide little information about what actually constitutes successful passing behaviour. Consequently, this has hampered the transfer of research findings into applied settings. Here we present two novel approaches to assess passing effectiveness in elite soccer by evaluating their effects on majority situations and space control in front of the goal. Majority situations are assessed by calculating the number of defenders between the ball carrier and the goal. Control of space is estimated using Voronoi-diagrams based on the player's positions on the pitch. Both methods were applied to position data from 103 German First division games from the 2011/2012, 2012/2013 and 2014/2015 seasons using a big data approach. The results show that both measures are significantly related to successful game play with respect to the number of goals scored and to the probability of winning a game. The results further show that on average passes from the mid-field into the attacking area are most effective. The presented passing efficiency measures thereby offer new opportunities for future applications in soccer and other sports disciplines whilst maintaining practical relevance with respect to tactical training regimes or game performances analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct measurement of first-pass ileal clearance of a bile acid in humans

International Nuclear Information System (INIS)

Galatola, G.; Jazrawi, R.P.; Bridges, C.; Joseph, A.E.; Northfield, T.C.

1991-01-01

The purpose of this study was to develop and validate a method of directly measuring ileal bile acid absorption efficiency during a single enterohepatic cycle (first-pass ileal clearance). This has become feasible for the first time because of the availability of the synthetic gamma-labeled bile acid 75Selena-homocholic acid-taurine (75SeHCAT). Together with the corresponding natural bile acid cholic acid-taurine (labeled with 14C), SeHCAT was infused distal to an occluding balloon situated beyond the ampulla of Vater in six healthy subjects. Completion of a single enterohepatic cycle was assessed by obtaining a plateau for 75SeHCAT activity proximal to the occluding balloon, which prevented further cycles. Unabsorbed 75SeHCAT was collected after total gut washout, which was administered distal to the occluding balloon. 75SeHCAT activity in the rectal effluent measured by gamma counter was compared with that of absorbed 75SeHCAT level measured by gamma camera and was used to calculate first-pass ileal clearance. This was very efficient (mean value, 96%) and showed very little variation in the six subjects studied (range, 95%-97%). A parallel time-activity course in hepatic bile for 14C and 75Se during a single enterohepatic cycle, together with a ratio of unity for 14C/75Se in samples obtained at different time intervals, suggests that 75SeHCAT is handled by the ileum like the natural bile acid cholic acid-taurine. Extrapolation of 75SeHCAT first-pass ileal clearance to that of the natural bile acid therefore seems justifiable. In a subsidiary experiment, ileal absorption efficiency per day for 75SeHCAT was also measured by scanning the gallbladder area on 5 successive days after the measurement of first-pass ileal clearance. In contrast with absorption efficiency per cycle, absorption efficiency per day varied widely (49%-86%)

Wavenumber-domain separation of rail contribution to pass-by noise

Science.gov (United States)

Zea, Elias; Manzari, Luca; Squicciarini, Giacomo; Feng, Leping; Thompson, David; Arteaga, Ines Lopez

2017-11-01

In order to counteract the problem of railway noise and its environmental impact, passing trains in Europe must be tested in accordance to a noise legislation that demands the quantification of the noise generated by the vehicle alone. However, for frequencies between about 500 Hz and 1600 Hz, it has been found that a significant part of the measured noise is generated by the rail, which behaves like a distributed source and radiates plane waves as a result of the contact with the train's wheels. Thus the need arises for separating the rail contribution to the pass-by noise in that particular frequency range. To this end, the present paper introduces a wavenumber-domain filtering technique, referred to as wave signature extraction, which requires a line microphone array parallel to the rail, and two accelerometers on the rail in the vertical and lateral direction. The novel contributions of this research are: (i) the introduction and application of wavenumber (or plane-wave) filters to pass-by data measured with a microphone array located in the near-field of the rail, and (ii) the design of such filters without prior information of the structural properties of the rail. The latter is achieved by recording the array pressure, as well as the rail vibrations with the accelerometers, before and after the train pass-by. The performance of the proposed method is investigated with a set of pass-by measurements performed in Germany. The results seem to be promising when compared to reference data from TWINS, and the largest discrepancies occur above 1600 Hz and are attributed to plane waves radiated by the rail that so far have not been accounted for in the design of the filters.

Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

International Nuclear Information System (INIS)

Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo; Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi.

1990-01-01

To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with 99m Tc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by 133 Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with 99m Tc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with 133 Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r= -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with 133 Xe SPECT and 99m Tc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease. (author)

Phase retrieval from a single fringe pattern by using empirical wavelet transform

International Nuclear Information System (INIS)

Guo, Xiaopeng; Zhao, Hong; Wang, Xin

2015-01-01

Phase retrieval from a single fringe pattern is one of the key tasks in optical metrology. In this paper, we present a new method for phase retrieval from a single fringe pattern based on empirical wavelet transform. In the proposed method, a fringe pattern can be effectively divided into three components: nonuniform background, fringes and random noise, which are described in different sub-pass. So the phase distribution information can be robustly extracted from fringes representing a fundamental frequency component. In simulation and a practical projection fringes test, the performance of the present method is successfully verified by comparing with the conventional wavelet transform method in terms of both image quality and phase estimation errors. (paper)

Assessment of resting-state blood flow through anterior cerebral arteries using trans-cranial doppler recordings.

Science.gov (United States)

Huang, Hanrui; Sejdić, Ervin

2013-12-01

Trans-cranial Doppler (TCD) recordings are used to monitor cerebral blood flow in the main cerebral arteries. The resting state is usually characterized by the mean velocity or the maximum Doppler shift frequency (an envelope signal) by insonating the middle cerebral arteries. In this study, we characterized cerebral blood flow in the anterior cerebral arteries. We analyzed both envelope signals and raw signals obtained from bilateral insonation. We recruited 20 healthy patients and conducted the data acquisition for 15 min. Features were extracted from the time domain, the frequency domain and the time-frequency domain. The results indicate that a gender-based statistical difference exists in the frequency and time-frequency domains. However, no handedness effect was found. In the time domain, information-theoretic features indicated that mutual dependence is higher in raw signals than in envelope signals. Finally, we concluded that insonation of the anterior cerebral arteries serves as a complement to middle cerebral artery studies. Additionally, investigation of the raw signals provided us with additional information that is not otherwise available from envelope signals. Use of direct trans-cranial Doppler raw data is therefore validated as a valuable method for characterizing the resting state. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Immediate loading with single-piece implant following extraction

Directory of Open Access Journals (Sweden)

Hemlata Dwivedi

2017-01-01

Full Text Available Although dental implantology had evolved over a number of years, many dental surgeons are unaware of the concept of immediate loading with the use of one-piece implant that began in the early 1960s. The goal of successful prosthodontics rehabilitation is to provide function, esthetics, and comfort to the patient. The aim of this literature is to provide an overview of one-piece implant, with its advantages and disadvantages over conventional two-piece implant. Immediate prosthetic of a one-piece system allows for a better tissue healing and better adhesion of gingival mucosa to form a collar which is healthy and adherent to the implant, avoiding a second surgical procedure, and also includes a very important aspect esthetics. This article describes a case report of immediate loading with single-piece implant following extraction.

Current status and outlook of endovascular therapy for cerebral ischemic diseases

International Nuclear Information System (INIS)

Li Minghua; Zhao Jungong

2005-01-01

Improvement of diagnostic technology and increasing advent of new materials for intervention has created a new area for endovascular therapy of cerebral ischemic diseases. Current research findings have shown that endovascular thrombolysis in acute stage of cerebral infarction can accelerate the rate of re-canalization of occluded arteries and greatly decrease the morbidity and mortality of cerebral ischemic vascular diseases. Stenting of arterial stenosis can the improve of blood supply distal to the lesion, prevent recurrent cerebral ischemic stroke. As a result, endovascular thrombolysis for acute cerebral infarction and stenting for intracranial and carotid arterial stenosis are booming both at home and abroad. Proper selection of patients of acute cerebral infarction for endovascular thrombolysis with less complications could be achieved through CT perfusion, MR perfusion-weighted image (PWI) and diffusion-weighted image (DWI), non-invasive vascular imaging technology including CEMRA and CTA for confirming and demonstrating the sites and causes of cerebral ischemia, and furthermore for evaluating the survival ability and etc. The research team administered albumin and magnesium sulfate as neurological protection drug to treat rat infarction model within 6 hours of onset resulting with the same effect of decreasing the damage of ischemic cerebral tissue and without hemorrhagic complication. It is certain that hemorrhagic complication in thrombolysis is a result of multiple factors with no single drug being able to solve the problem. It is predictable that, based on semi-quantitative or quantitative parameters of CT or MRI in conjunction with PWI/DWI mismatch model rather than simply on the onset time of infarction for proper selection of patients of cerebral infarction, mechanic thrombus-disruption and/or intra-arterial thrombolysis together with intervention of neurological protection drug will be the trend for treating acute cerebral infarction in the future

Cerebral autoregulation control of blood flow in the brain

CERN Document Server

Payne, Stephen

2016-01-01

This Brief provides a comprehensive introduction to the control of blood flow in the brain. Beginning with the basic physiology of autoregulation, the author goes on to discuss measurement techniques, mathematical models, methods of analysis, and relevant clinical conditions, all within this single volume. The author draws together this disparate field, and lays the groundwork for future research directions. The text gives an up-to-date review of the state of the art in cerebral autoregulation, which is particularly relevant as cerebral autoregulation moves from the laboratory to the bedside. Cerebral Autoregulation will be useful to researchers in the physical sciences such as mathematical biology, medical physics, and biomedical engineering whose work is concerned with the brain. Researchers in the medical sciences and clinicians dealing with the brain and blood flow, as well as industry professionals developing techniques such as ultrasound, MRI, and CT will also find this Brief of interest.

Regional cerebral blood flow and oxygen metabolism in normal pressure hydrocephalus after subarachnoid hemorrhage

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Ishikawa, Masatsune; Kikuchi, Haruhiko; Taki, Waro; Kobayashi, Akira; Nishizawa, Sadahiko; Yonekura, Yoshiharu; Konishi, Junji [Kyoto Univ. (Japan). Faculty of Medicine

1989-05-01

To clarify the pathophysiology of normal pressure hydrocephalus (NPH) after subarachnoid hemorrhage, the authors measured cerebral blood flow (CBF), cerebral oxygen metabolic rates (CMRO{sub 2}), the cerebral oxygen extraction fraction (OEF), and cerebral blood volume (CBV) in eight normal volunteers, six SAH patients with NPH, and seven patients without NPH by {sup 15}O-labeled gas and positron emission tomography (PET). In the NPH group, PET revealed a decrease in CBF in the lower regions of the cerebral cortex and a diffuse decrease in CMRO{sub 2}. The decrease in CBF in the lower frontal, temporal, and occipital cortices was significantly greater in the NPH than in the non-NPH group. Reduction of CMRO{sub 2} was also more extensive in the NPH group, and both CBF and CMRO{sub 2} were more markedly decreased in the lower frontal region. OEF was increased in all areas in both of the patient groups, but the increase was not significant in most areas. CBF, CMRO{sub 2} and OEF did not significantly differ between the non-NPH group and the normal volunteers. There was no significant difference in CBV among the three groups. These results indicate that NPH involves impairment of cerebral oxygen metabolism in the lower regions of the cerebral cortex, particularly in the lower frontal region. (author).

Wave-optics simulation of the double-pass beam propagation in modulating retro-reflector FSO systems using a corner cube reflector.

Science.gov (United States)

Yang, Guowei; You, Shengzui; Bi, Meihua; Fan, Bing; Lu, Yang; Zhou, Xuefang; Li, Jing; Geng, Hujun; Wang, Tianshu

2017-09-10

Free-space optical (FSO) communication utilizing a modulating retro-reflector (MRR) is an innovative way to convey information between the traditional optical transceiver and the semi-passive MRR unit that reflects optical signals. The reflected signals experience turbulence-induced fading in the double-pass channel, which is very different from that in the traditional single-pass FSO channel. In this paper, we consider the corner cube reflector (CCR) as the retro-reflective device in the MRR. A general geometrical model of the CCR is established based on the ray tracing method to describe the ray trajectory inside the CCR. This ray tracing model could treat the general case that the optical beam is obliquely incident on the hypotenuse surface of the CCR with the dihedral angle error and surface nonflatness. Then, we integrate this general CCR model into the wave-optics (WO) simulation to construct the double-pass beam propagation simulation. This double-pass simulation contains the forward propagation from the transceiver to the MRR through the atmosphere, the retro-reflection of the CCR, and the backward propagation from the MRR to the transceiver, which can be realized by a single-pass WO simulation, the ray tracing CCR model, and another single-pass WO simulation, respectively. To verify the proposed CCR model and double-pass WO simulation, the effective reflection area, the incremental phase, and the reflected beam spot on the transceiver plane of the CCR are analyzed, and the numerical results are in agreement with the previously published results. Finally, we use the double-pass WO simulation to investigate the double-pass channel in the MRR FSO systems. The histograms of the turbulence-induced fading in the forward and backward channels are obtained from the simulation data and are fitted by gamma-gamma (ΓΓ) distributions. As the two opposite channels are highly correlated, we model the double-pass channel fading by the product of two correlated �

Clinical significance of posterior cerebral artery stenosis/occlusion in moyamoya disease

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Kuroda, Satoshi; Ishikawa, Tatsuya; Iwasaki, Yoshinobu [Hokkaido Univ., Sapporo (Japan). Graduate School of Medicine; Houkin, Kiyohiro [Sapporo Medical Univ. (Japan)

2002-12-01

The present study was aimed at clarifying the clinical significance of posterior cerebral artery (PCA) stenosis/occlusion in pediatric and adult moyamoya disease. This study included a total of 132 patients (52 children and 80 adults) who were diagnosed as by cerebral angiography having moyamoya disease. CT or MRI was performed to examine the location of cerebral infarction in all subjects. Cerebral blood flow and vasoreactivity to acetazolamide were measured in 80 patients before surgery, using single photon emission computed tomography (SPECT). Three-dimensional MR angiography (3D-MRA) was repeated in 32 pediatric patients after surgery in order to clarify the natural course of the PCA stenosis/occlusion. Of 264 sides in 132 patients, PCA stenosis/occlusion was observed in 50 sides of 40 patients (30.3%). Its incidence was significantly higher in ischemic-type patients than in hemorrhagic-type and asymptomatic patients, and was higher in patients in the advanced stage of the disease. The hemisphere ipsilateral to PCA stenosis/occlusion had higher incidence of ischemic symptoms, cerebral infarction, and impaired cerebral hemodynamics. Transient ischemic attack (TIA) (hemianopsia) or cerebral infarction in the occipital lobe was noted in 4 (10%) of 40 patients during follow-up periods after bypass surgery for anterior circulation. Of 32 pediatric patients, none showed progression of PCA stenosis on 3D-MRA during follow-up periods. The present study showed that the involvement of PCA could increase the risk of TIA and/or cerebral infarction in both anterior and posterior circulation areas, suggesting that the PCA plays an important collateral role in moyamoya disease. (author)

Extracting 3D layout from a single image using global image structures.

Science.gov (United States)

Lou, Zhongyu; Gevers, Theo; Hu, Ninghang

2015-10-01

Extracting the pixel-level 3D layout from a single image is important for different applications, such as object localization, image, and video categorization. Traditionally, the 3D layout is derived by solving a pixel-level classification problem. However, the image-level 3D structure can be very beneficial for extracting pixel-level 3D layout since it implies the way how pixels in the image are organized. In this paper, we propose an approach that first predicts the global image structure, and then we use the global structure for fine-grained pixel-level 3D layout extraction. In particular, image features are extracted based on multiple layout templates. We then learn a discriminative model for classifying the global layout at the image-level. Using latent variables, we implicitly model the sublevel semantics of the image, which enrich the expressiveness of our model. After the image-level structure is obtained, it is used as the prior knowledge to infer pixel-wise 3D layout. Experiments show that the results of our model outperform the state-of-the-art methods by 11.7% for 3D structure classification. Moreover, we show that employing the 3D structure prior information yields accurate 3D scene layout segmentation.

Simultaneous measurement of cerebral blood flow and oxygen extraction fraction by positron emission tomography: theoretical study and experimental evidence of cerebral blood flow measurement with the C15O2 continuous inhalation technique

International Nuclear Information System (INIS)

Steinling, M.

1983-01-01

The method of the continuous inhalation technique of oxygen-15 labelled CO 2 coupled with positron emission tomography for the measurement of cerebral blood flow (C.B.F.) is described. An indirect experimental verification that this technique allowed the measurement of C.B.F. has been carried out in baboons by showing the expected change in the measured parameter with variations in the PaCO 2 . A critical investigation of the C 15 O 2 model was performed. The amount of tracer present in the cerebral vascular pool has a negligible effect on C.B.F. value. The use of a mean brain-blood partition coefficient of water instead of that specific to gray or to white matter is commented upon, and its influence on the final C.B.F. value is studied. Lastly, the problem of the limited diffusion of water across the blood-brain-barrier is discussed. The study of the combined effects of gray-white mixing and limited wates extraction of the C.B.F. value shows that the C 15 O 2 technique tends to understimate real C.B.F., and that this error is more severe with high flows and even gray white mixing. These limitations do not depart from the possibility to estimate in the same brain locus not only C.B.F. but oxygen utilization as well by the consecutive inhalation of C 15 O 2 and 15 O 2 . The advantages of this possibility has already been shown in a number of clinical studies [fr

Unilateral cerebral polymicrogyria with ipsilateral cerebral hemiatrophy

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Katsumi [Department of Radiology, Kyoto City Hospital, 1-2 Higashi-Takada-cho, Mibu, Nakagyo-ku, 604-8845 Kyoto (Japan); Kanda, Toyoko; Yamori, Yuriko [Department of Pediatric Neurology, St. Joseph Hospital for Handicapped Children, 603-8323 Kyoto (Japan)

2002-10-01

We evaluated six children in whom MR imaging showed unilateral cerebral polymicrogyria associated with ipsilateral cerebral atrophy and ipsilateral brain stem atrophy. The aim of this study was to clarify whether this disorder based on neuroimaging constitutes a new homogeneous clinical entity. The subjects were six children whose ages at the time of MR imaging ranged from 8 months to 11 years. Their clinical and MR features were analyzed. All of the children were born between 38 and 42 weeks gestation, without any significant perinatal events. Spastic hemiplegia and epilepsy were observed in all of the patients, and mental retardation was observed in four. The MR findings included unilateral cerebral polymicrogyria associated with ipsilateral cerebral hemiatrophy and ipsilateral brain stem atrophy in all patients. The ipsilateral sylvian fissure was hypoplastic in four patients. These patients showed relatively homogeneous clinical and neuroimaging features. Although the additional clinical features varied according to the site and the extent affected by the polymicrogyria, this disorder could constitute a new relatively homogeneous clinical entity. (orig.)

Unilateral cerebral polymicrogyria with ipsilateral cerebral hemiatrophy

International Nuclear Information System (INIS)

Hayakawa, Katsumi; Kanda, Toyoko; Yamori, Yuriko

2002-01-01

We evaluated six children in whom MR imaging showed unilateral cerebral polymicrogyria associated with ipsilateral cerebral atrophy and ipsilateral brain stem atrophy. The aim of this study was to clarify whether this disorder based on neuroimaging constitutes a new homogeneous clinical entity. The subjects were six children whose ages at the time of MR imaging ranged from 8 months to 11 years. Their clinical and MR features were analyzed. All of the children were born between 38 and 42 weeks gestation, without any significant perinatal events. Spastic hemiplegia and epilepsy were observed in all of the patients, and mental retardation was observed in four. The MR findings included unilateral cerebral polymicrogyria associated with ipsilateral cerebral hemiatrophy and ipsilateral brain stem atrophy in all patients. The ipsilateral sylvian fissure was hypoplastic in four patients. These patients showed relatively homogeneous clinical and neuroimaging features. Although the additional clinical features varied according to the site and the extent affected by the polymicrogyria, this disorder could constitute a new relatively homogeneous clinical entity. (orig.)

Impact of one-to-one tutoring on fundamentals of laparoscopic surgery (FLS) passing rate in a single center experience outside the United States: a randomized controlled trial.

Science.gov (United States)

Gheza, Federico; Raimondi, Paolo; Solaini, Leonardo; Coccolini, Federico; Baiocchi, Gian Luca; Portolani, Nazario; Tiberio, Guido Alberto Massimo

2018-04-11

Outside the US, FLS certification is not required and its teaching methods are not well standardized. Even if the FLS was designed as "stand alone" training system, most of Academic Institution offer support to residents during training. We present the first systematic application of FLS in Italy. Our aim was to evaluate the role of mentoring/coaching on FLS training in terms of the passing rate and global performance in the search for resource optimization. Sixty residents in general surgery, obstetrics & gynecology, and urology were selected to be enrolled in a randomized controlled trial, practicing FLS with the goal of passing a simulated final exam. The control group practiced exclusively with video material from SAGES, whereas the interventional group was supported by a mentor. Forty-six subjects met the requirements and completed the trial. For the other 14 subjects no results are available for comparison. One subject for each group failed the exam, resulting in a passing rate of 95.7%, with no obvious differences between groups. Subgroup analysis did not reveal any difference between the groups for FLS tasks. We confirm that methods other than video instruction and deliberate FLS practice are not essential to pass the final exam. Based on these results, we suggest the introduction of the FLS system even where a trained tutor is not available. This trial is the first single institution application of the FLS in Italy and one of the few experiences outside the US. Trial Number: NCT02486575 ( https://www.clinicaltrials.gov ).

Quantitative measurement of cerebral oxygen extraction fraction using MRI in patients with MELAS.

Directory of Open Access Journals (Sweden)

Lei Yu

Full Text Available OBJECTIVE: To quantify the cerebral OEF at different phases of stroke-like episodes in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS by using MRI. METHODS: We recruited 32 patients with MELAS confirmed by gene analysis. Conventional MRI scanning, as well as functional MRI including arterial spin labeling and oxygen extraction fraction imaging, was undertaken to obtain the pathological and metabolic information of the brains at different stages of stroke-like episodes in patients. A total of 16 MRI examinations at the acute and subacute phase and 19 examinations at the interictal phase were performed. In addition, 24 healthy volunteers were recruited for control subjects. Six regions of interest were placed in the anterior, middle, and posterior parts of the bilateral hemispheres to measure the OEF of the brain or the lesions. RESULTS: OEF was reduced significantly in brains of patients at both the acute and subacute phase (0.266 ± 0.026 and at the interictal phase (0.295 ± 0.009, compared with normal controls (0.316 ± 0.025. In the brains at the acute and subacute phase of the episode, 13 ROIs were prescribed on the stroke-like lesions, which showed decreased OEF compared with the contralateral spared brain regions. Increased blood flow was revealed in the stroke-like lesions at the acute and subacute phase, which was confined to the lesions. CONCLUSION: MRI can quantitatively show changes in OEF at different phases of stroke-like episodes. The utilization of oxygen in the brain seems to be reduced more severely after the onset of episodes in MELAS, especially for those brain tissues involved in the episodes.

Effect of salvia Egyptiaca extract on cholinergic system in adult male albino rats

International Nuclear Information System (INIS)

Abdel Kader, S.M.

2004-01-01

The daily oral administrations of Salvia aegyptiaca extract, equivalent to 2 g/kg body weight for 4 weeks, caused significant decrease in acetylcholine esterase activity in whole blood and in all tested brain areas (cerebellum, pons + medulla oblongata, striatum, cerebral cortex, hypothalamus, midbrain and hippocampus) of male albino rat nearly all over the experimental period. Treatment with Salvia aegyptiaca extract also resulted in significant increase in acetylcholine content in the cerebral cortex and hippocampus' nearly throughout the whole experimental period. It could be concluded from the present results that the extract of Salvia aegyptiaca caused an increase in acetylcholine content and this increase may be due to the decrease in the activity of acetylcholine esterase enzyme which play an important role in the treatment of Alzheimer's disease

The effect of sodium nitroprusside on cerebral hemodynamics and headache in healthy subjects

DEFF Research Database (Denmark)

Guo, Song; Ashina, Messoud; Olesen, Jes

2013-01-01

InvestigationSodium nitroprusside (SNP) is a powerful vasodilatory agent that, similarly to glyceryl trinitrate (GTN), releases nitric oxide (NO) but in contrast does not pass the blood-brain barrier. Nevertheless, it has already been used in animal models without any knowledge of its headache......-inducing potential. We hypothesized that SNP would induce headache and vasodilation of cephalic and radial but not cerebral arteries.MethodsFive healthy volunteers received intravenous infusions of SNP in a non-randomized dose-titration (1-5 µg/kg/min) study. We recorded headache intensity (verbal rating scale from...

Cerebral palsy and congenital malformations

DEFF Research Database (Denmark)

Garne, Ester; Dolk, Helen; Krägeloh-Mann, Inge

2007-01-01

AIM: To determine the proportion of children with cerebral palsy (CP) who have cerebral and non-cerebral congenital malformations. METHODS: Data from 11 CP registries contributing to the European Cerebral Palsy Database (SCPE), for children born in the period 1976-1996. The malformations were...... classified as recognized syndromes, chromosomal anomalies, cerebral malformations or non-cerebral malformations. Prevalence of malformations was compared to published data on livebirths from a European database of congenital malformations (EUROCAT). RESULTS: Overall 547 out of 4584 children (11.9%) with CP...... were reported to have a congenital malformation. The majority (8.6% of all children) were diagnosed with a cerebral malformation. The most frequent types of cerebral malformations were microcephaly and hydrocephaly. Non-cerebral malformations were present in 97 CP children and in further 14 CP children...

Cerebral haemodynamic and metabolic changes in carotid artery occlusion: a PET study

International Nuclear Information System (INIS)

Samson, Y.; Loc'h, C.; Ottaviani, M.; Baron, J.C.; Bousser, M.

1984-09-01

Using the positron emission tomography, with the O 15 inhalation technique, the cerebral blood flow (CBF), the oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO 2 ) were studied in 37 patients with internal carotid artery (ICA) occlusion. In the territory of the occluded ICA, two pattern of focal anomaly have been observed: a CBF decrease with a ''compensatory'' OEF increase or a matched CBF and CMRO 2 decrease. On the other hand, as compared to age matched control values, CMRO 2 is significantly decreased in the territory of the occluded carotid only in patients with extensive neck vessels obstructive disease

Cerebral Palsy

Science.gov (United States)

Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

Feasibility study of multi-pass respiratory-gated helical tomotherapy of a moving target via binary MLC closure

Science.gov (United States)

Kim, Bryan; Chen, Jeff; Kron, Tomas; Battista, Jerry

2010-11-01

Gated radiotherapy of lung lesions is particularly complex for helical tomotherapy, due to the simultaneous motions of its three subsystems (gantry, couch and collimator). We propose a new way to implement gating for helical tomotherapy, namely multi-pass respiratory gating. In this method, gating is achieved by delivering only the beam projections that occur within a respiratory gating window, while blocking the rest of the beam projections by fully closing all collimator leaves. Due to the continuous couch motion, the planned beam projections must be delivered over multiple passes of radiation deliveries. After each pass, the patient couch is reset to its starting position, and the treatment recommences at a different phase of tumour motion to 'fill in' the previously blocked beam projections. The gating process may be repeated until the plan dose is delivered (full gating), or halted after a certain number of passes, with the entire remaining dose delivered in a final pass without gating (partial gating). The feasibility of the full gating approach was first tested for sinusoidal target motion, through experimental measurements with film and computer simulation. The optimal gating parameters for full and partial gating methods were then determined for various fractionation schemes through computer simulation, using a patient respiratory waveform. For sinusoidal motion, the PTV dose deviations of -29 to 5% observed without gating were reduced to range from -1 to 3% for a single fraction, with a 4 pass full gating. For a patient waveform, partial gating required fewer passes than full gating for all fractionation schemes. For a single fraction, the maximum allowed residual motion was only 4 mm, requiring large numbers of passes for both full (12) and partial (7 + 1) gating methods. The number of required passes decreased significantly for 3 and 30 fractions, allowing residual motion up to 7 mm. Overall, the multi-pass gating technique was shown to be a promising

Feasibility study of multi-pass respiratory-gated helical tomotherapy of a moving target via binary MLC closure

Energy Technology Data Exchange (ETDEWEB)

Kim, Bryan; Chen, Jeff; Battista, Jerry [London Regional Cancer Program, London Health Sciences Centre, London, ON (Canada); Kron, Tomas, E-mail: bryan.kim@lhsc.on.c [Peter MacCallum Cancer Center, Melbourne (Australia)

2010-11-21

Gated radiotherapy of lung lesions is particularly complex for helical tomotherapy, due to the simultaneous motions of its three subsystems (gantry, couch and collimator). We propose a new way to implement gating for helical tomotherapy, namely multi-pass respiratory gating. In this method, gating is achieved by delivering only the beam projections that occur within a respiratory gating window, while blocking the rest of the beam projections by fully closing all collimator leaves. Due to the continuous couch motion, the planned beam projections must be delivered over multiple passes of radiation deliveries. After each pass, the patient couch is reset to its starting position, and the treatment recommences at a different phase of tumour motion to 'fill in' the previously blocked beam projections. The gating process may be repeated until the plan dose is delivered (full gating), or halted after a certain number of passes, with the entire remaining dose delivered in a final pass without gating (partial gating). The feasibility of the full gating approach was first tested for sinusoidal target motion, through experimental measurements with film and computer simulation. The optimal gating parameters for full and partial gating methods were then determined for various fractionation schemes through computer simulation, using a patient respiratory waveform. For sinusoidal motion, the PTV dose deviations of -29 to 5% observed without gating were reduced to range from -1 to 3% for a single fraction, with a 4 pass full gating. For a patient waveform, partial gating required fewer passes than full gating for all fractionation schemes. For a single fraction, the maximum allowed residual motion was only 4 mm, requiring large numbers of passes for both full (12) and partial (7 + 1) gating methods. The number of required passes decreased significantly for 3 and 30 fractions, allowing residual motion up to 7 mm. Overall, the multi-pass gating technique was shown to be a

Nonstationary multivariate modeling of cerebral autoregulation during hypercapnia.

Science.gov (United States)

Kostoglou, Kyriaki; Debert, Chantel T; Poulin, Marc J; Mitsis, Georgios D

2014-05-01

We examined the time-varying characteristics of cerebral autoregulation and hemodynamics during a step hypercapnic stimulus by using recursively estimated multivariate (two-input) models which quantify the dynamic effects of mean arterial blood pressure (ABP) and end-tidal CO2 tension (PETCO2) on middle cerebral artery blood flow velocity (CBFV). Beat-to-beat values of ABP and CBFV, as well as breath-to-breath values of PETCO2 during baseline and sustained euoxic hypercapnia were obtained in 8 female subjects. The multiple-input, single-output models used were based on the Laguerre expansion technique, and their parameters were updated using recursive least squares with multiple forgetting factors. The results reveal the presence of nonstationarities that confirm previously reported effects of hypercapnia on autoregulation, i.e. a decrease in the MABP phase lead, and suggest that the incorporation of PETCO2 as an additional model input yields less time-varying estimates of dynamic pressure autoregulation obtained from single-input (ABP-CBFV) models. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Multimodal quantitation of the effects of endovascular therapy for vasospasm on cerebral blood flow, transcranial doppler ultrasonographic velocities, and cerebral artery diameters.

Science.gov (United States)

Oskouian, Rod J; Martin, Neil A; Lee, Jae Hong; Glenn, Thomas C; Guthrie, Donald; Gonzalez, Nestor R; Afari, Arash; Viñuela, Fernando

2002-07-01

The goal of this study was to quantify the effects of endovascular therapy on vasospastic cerebral vessels. We reviewed the medical records for 387 patients with ruptured intracranial aneurysms who were treated at a single institution (University of California, Los Angeles) between May 1, 1993, and March 31, 2001. Patients who developed cerebral vasospasm and underwent cerebral arteriographic, transcranial Doppler ultrasonographic, and cerebral blood flow (CBF) studies before and after endovascular therapy for cerebral arterial spasm (vasospasm) were included in this study. Forty-five patients fulfilled the aforementioned criteria and were treated with either papaverine infusion, papaverine infusion with angioplasty, or angioplasty alone. After balloon angioplasty (12 patients), CBF increased from 27.8 +/- 2.8 ml/100 g/min to 28.4 +/- 3.0 ml/100 g/min (P = 0.87); the middle cerebral artery blood flow velocity was 1 57.6 +/- 9.4 cm/s and decreased to 76.3 +/- 9.3 cm/s (P < 0.05), with a mean increase in cerebral artery diameters of 24.4%. Papaverine infusion (20 patients) transiently increased the CBF from 27.5 +/- 2.1 ml/100 g/min to 38.7 +/- 2.8 ml/100 g/min (P < 0.05) and decreased the middle cerebral artery blood flow velocity from 109.9 +/- 9.1 cm/s to 82.8 +/- 8.6 cm/s (P < 0.05). There was a mean increase in vessel diameters of 30.1% after papaverine infusion. Combined treatment (13 patients) significantly increased the CBF from 33.3 +/- 3.2 ml/100 g/min to 41.7 +/- 2.8 ml/100 g/min (P< 0.05) and decreased the transcranial Doppler velocities from 148.9 +/- 12.7 cm/s to 111.4 +/- 10.6 cm/s (P < 0.05), with a mean increase in vessel diameters of 42.2%. Balloon angioplasty increased proximal vessel diameters, whereas papaverine treatment effectively dilated distal cerebral vessels. In our small series, we observed no correlation between early clinical improvement or clinical outcomes and any of our quantitative or physiological data (CBF, transcranial Doppler

Evaluation of the single-pass flow-through test to support a low-activity waste specification

International Nuclear Information System (INIS)

McGrail, B.P.; Peeler, D.K.

1995-09-01

A series of single-pass flow-through (SPFT) tests was performed on five reference low-activity waste glasses and a reference glass from the National Institute of Standards and Technology to support a product specification for low-activity waste (LAW) forms. The results showed that the SPFT test provides a means to quantitatively distinguish among LAW glass forms in terms of their forward reaction rate at a given temperature and solution pH. Two of the test glasses were also subjected to SPFT testing at Argonne National Laboratory (ANL). Forward reaction rate constants calculated from the ANL test data were 100 to over 1,000 times larger than the values obtained from the SPFT tests conducted at PNL. An analysis of the ANL results showed that they were inconsistent with independent measurements done on glasses of similar composition, the known pH-dependence of the forward rate, and with the results from low surface-area-to-volume, short duration product consistency tests. Because the data set obtained from the SPFT tests done at PNL was consistent with each of these same factors, a detailed examination of the test procedures used at both laboratories was performed to determine the cause(s) of the discrepancy. The omission of background subtraction in the data analysis procedure and the short-duration (on the order of hours) of the ANL tests are factors that may have significantly affected the calculated rates

Genetic modification of cerebral arterial wall: implications for prevention and treatment of cerebral vasospasm.

Science.gov (United States)

Vijay, Anantha; Santhanam, R; Katusic, Zvonimir S

2006-10-01

Genetic modification of cerebral vessels represents a promising and novel approach for prevention and/or treatment of various cerebral vascular disorders, including cerebral vasospasm. In this review, we focus on the current understanding of the use of gene transfer to the cerebral arteries for prevention and/or treatment of cerebral vasospasm following subarachnoid hemorrhage (SAH). We also discuss the recent developments in vascular therapeutics, involving the autologous use of progenitor cells for repair of damaged vessels, as well as a cell-based gene delivery approach for the prevention and treatment of cerebral vasospasm.

Applications and diagnostic value of cerebral scintiscanning using /sup 123/I-amphetamine

Energy Technology Data Exchange (ETDEWEB)

Eibach, E.; Feine, U.; Kaiser, W.; Diener, H.C.; Petersen, D.

1985-02-01

/sup 123/I-IMP is a new radiopharmaceutical for direct cerebral scintiscanning, characterized by its ability to cross the blood-brain barrier and its accumulation in the brain. Present clinical indications are illustrated by examples (disturbances of cerebral blood flow, epilepsy, organic psychosyndrome). Single photon emission computerized tomography (SPECT) permits imaging in three planes (cantho-meatal, frontal, sagittal), although it lacks the morphological quality of TCT or NMR images. The new substance may open up new perspectives in neurophysiology and neuropharmacology.

Cerebral toxoplasmosis in AIDS - computerized tomography evaluation

International Nuclear Information System (INIS)

Alves, Regina Coeli Fonseca; Narchiori, Edson

1999-01-01

Cerebral toxoplasmosis is a disease that affects many AIDS's patients. FOr this paper 46 patients with confirmed cases of cerebral toxoplasmosis who did a CT scan between March, 1994 and September, 1997 were examined. Single lesions were found in 28.3% of the patients. The lesions were more frequently detected in the basal ganglia and the frontal lobes. No lesion was larger than 4 cm. As regards the contrast enhancing of the lesions on a CT scan we observed that 54.5% of the lesions had a ring-like contrast enhancing, 36.4% had a nodular contrast enhancing and 6% had a heterogeneous form. After the 21st day of treatment we noticed an improvement in the aspect of the patients'lesions. The improvement of the lesions could be seen through a reduction of the edematous halo, a reduction of the lesion size and a modification in the contrast enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility enhancing on the CT scan. The CT scan was an important method to demonstrate the lesions compatibility with cerebral toxoplasmosis, as well as to monitor these patients during treatment. (author)

Impairment of neuropsychological function in patients with hemodynamic cerebral ischemia and efficacy of bypass surgery

International Nuclear Information System (INIS)

Sasoh, Masayuki

1999-01-01

In order to evaluate the relation between neuropsychological functions and hemodynamic cerebral ischemia, the author analyzed neuropsychological examination and the cerebral blood flow and metabolism of patients before and after bypass surgery. Twenty-five patients were defined by clinical and laboratory criteria as suffering from hemodynamic cerebral ischemia. All patients had one or more episodes of focal cerebral ischemia due to unilateral internal carotid or middle cerebral artery occlusion. Computerized tomography scans either were normal or showed evidence of watershed infarction. Based on these criteria, superficial temporal artery-proximal middle cerebral artery anastomosis was performed. The baseline cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen (CMRO 2 ) and cerebrovascular reserve capacity (CVRC) were studied using positron emission computerized tomography (PET) and the acetazolamide test. Neuropsychological evaluations including Hasegawa Dementia Scale-Revised, Mini-Mental State and Wechsler Adult Intelligence Scale-Revised (WAIS-R), and PET study were completed one month after the last ischemic event and 3-6 months after the operation. A significant negative correlation was observed between OEF and neuropsychological functions. Postoperative neuropsychological functions showed significant improvement. Significant correlations were observed for ΔWAIS-R (preoperative WAIS-R postoperative WAIS-R) versus preoperative CMRO 2 (r=0.52), for ΔWAIS-R versus preoperative OEF (r=0.47). In view of these findings, the author concludes that elevation of OEF impairs neuropsychological functions and bypass surgery improves neuropsychological functions in patients with normal CMRO 2 and elevated OEF. (author)

Three-Input Single-Output Voltage-Mode Multifunction Filter with Electronic Controllability Based on Single Commercially Available IC

Directory of Open Access Journals (Sweden)

Supachai Klungtong

2017-01-01

Full Text Available This paper presents a second-order voltage-mode filter with three inputs and single-output voltage using single commercially available IC, one resistor, and two capacitors. The used commercially available IC, called LT1228, is manufactured by Linear Technology Corporation. The proposed filter is based on parallel RLC circuit. The filter provides five output filter responses, namely, band-pass (BP, band-reject (BR, low-pass (LP, high-pass (HP, and all-pass (AP functions. The selection of each filter response can be done without the requirement of active and passive component matching condition. Furthermore, the natural frequency and quality factor are electronically controlled. Besides, the nonideal case is also investigated. The output voltage node exhibits low impedance. The experimental results can validate the theoretical analyses.

Regional cerebral blood flow changes in schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-[123I]iodoamphetamine (IMP)

International Nuclear Information System (INIS)

Kanaya, Toshinori

1989-01-01

Regional cerebral blood flows (rCBF) were measured in patients with schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-[ 123 I]iodoamphetamine (IMP). The subjects were 20 patients with shizophrenia, 32 patients with endogenous depression and 20 normal controls. The patients with depression were divided into 3 groups; unmedicated, medicated patients in depressive state, and medicated patients in remited state. The rCBF were calculated by the corticocerebellar ratio (CCR), which was expressed as a ratio of activity per pixel in cortical regions of interest to the activity per pixel in the cerebellum. The results were as follows. In patients with schizophrenia the marked decrease in rCBF in bilateral frontal regions and the lower rCBF in the left than in the right hemisphere were observed. There was no significant correlation between the mean rCBF and BPRS (Brief Psychiatric Rating Scale) in patients with shizophrenia. In patients with depression the decrease in rCBF in overall cerebral regions and the lower rCBF in the left than in the right hemisphere were observed in both groups in depressive state. These changes were normalized in remited state, though there was no significant difference in rCBF between on medication and off medication. There was significantly negative correlation between the mean rCBF and Hamilton Depression Rating Scale in patients with depression. These results support the previously reported 'hypofrontality' and the left hemispheric dysfunction in shizophrenia. In depressive patients the overall cerebral dysfunction was revealed more remarkablly in the left than in the right hemisphere, which was normalized following the improvement of depressive symptoms. Furthermore, it was suggested that the applications of IMP-SPECT could be useful for the diagnosis and research for the cerebral function in mental illness. (author) 59 refs

Single-column extraction chromatographic separation of U, Pu, Np and Am

Energy Technology Data Exchange (ETDEWEB)

Morgenstern, A.; Apostolidis, C.; Carlos-Marquez, R.; Mayer, K.; Molinet, R. [Commission of the European Communities, Karlsruhe (Germany). European Inst. for Transuranium Elements

2002-07-01

A rapid, single-column extraction chromatographic method using commercially available UTEVA resin has been developed for the separation of uranium, plutonium, neptunium and americium. The method yields recoveries superior to 90% and allows direct loading of separated fractions on filaments for subsequent analysis by thermal ionization mass spectrometry. The use of reagents compatible with robotized equipment allows automation of the separation process for routine analysis of nuclear materials. The redox reactions between plutonium, neptunium and hydrogen peroxide involved in the separation process were studied by UV/Vis/NIR absorption spectroscopy. (orig.)

Regional cerebral blood flow in Angelman syndrome

International Nuclear Information System (INIS)

Guecueyener, K.; Goekcora, N.; Ilgin, N.; Buyan, N.; Sayli, A.

1993-01-01

A patient with typical features of Angelman syndrome - a genetically inherited disorder involving developmental delay, ataxia, episodes of paroxysmal laughter and brachiocephaly - was studied with single-photon emission tomography. Hyperfusion found in the left frontal and left temporoparietal regions can provide insights into the functional cerebral pathology, which may be due to a disturbance of the developmental process related to a chromosomal abnormality. (orig.)

Regional cerebral blood flow in Angelman syndrome

Energy Technology Data Exchange (ETDEWEB)

Guecueyener, K [Dept. of Pediatric Neurology, Faculty of Medicine, Gazi Univ., Ankara (Turkey); Goekcora, N [Dept. of Nuclear Medicine, Faculty of Medicine, Gazi Univ., Ankara (Turkey); Ilgin, N [Dept. of Nuclear Medicine, Faculty of Medicine, Gazi Univ., Ankara (Turkey); Buyan, N [Dept. of Pediatric Neurology, Faculty of Medicine, Gazi Univ., Ankara (Turkey); Sayli, A [Dept. of Molecular Biology and Genetics, Faculty of Medicine, Gazi Univ., Ankara (Turkey)

1993-07-01

A patient with typical features of Angelman syndrome - a genetically inherited disorder involving developmental delay, ataxia, episodes of paroxysmal laughter and brachiocephaly - was studied with single-photon emission tomography. Hyperfusion found in the left frontal and left temporoparietal regions can provide insights into the functional cerebral pathology, which may be due to a disturbance of the developmental process related to a chromosomal abnormality. (orig.)

Cerebral hemodynamics and functional prognosis in hydrocephalus

International Nuclear Information System (INIS)

Hirai, Osamu; Nishikawa, Michio; Watanabe, Shu; Yamakawa, Hiroyasu; Kinoshita, Yoshimasa; Uno, Akira; Handa, Hajime

1989-01-01

The functional outcome of cerebral hemodynamics in the chronic stage of juvenile hydrocephalus was determined using single photon emission computed tomography (SPECT). Five patients including three with aqueductal stenosis, one with post-meningitic hydrocephalus, and one case with hydrocephalus having developed after repair of a huge occipital encephalocele. Early images of cerebral blood flow (CBF) were obtained 25 minutes after intravenous injection of 123-I-iodoamphetamine (IMP), and late images were scanned 3 hours later. Cerebral blood volume (CBV) was also measured using 99m Tc in three patients. Twenty cases with adult communicating hydrocephalus were also investigated from the point of view of shunt effectiveness. Although there was no remarkable change in the cerebrovascular bed in the juvenile cases, CBF of the remnant brain parenchyma was good irrespective of the degree of ventricular dilatation. There was a periventricular-related IMP uptake in each case; however, it somehow matched the ventricular span. Functional outcome one to 23 years after the initial shunt operation was good in every case, despite multiple shunt revisions. Redistribution on late images had no bearing on clinical states. In adult cases, 8 patients with effective shunting demonstrated a relatively localized periventricular low perfusion, with preoperative increased cerebrospinal fluid (CSF) pressure. On the contrary, 12 patients with no improvement with or without ventricular-reduced IMP uptake, despite low CSF pressure. The present study indicates that periventricular hemodynamics may play an important role in cerebral function compromised by hydrocephalus. (J.P.N.)

Cerebral hemodynamics and functional prognosis in hydrocephalus

Energy Technology Data Exchange (ETDEWEB)

Hirai, Osamu; Nishikawa, Michio; Watanabe, Shu; Yamakawa, Hiroyasu; Kinoshita, Yoshimasa; Uno, Akira; Handa, Hajime (Hamamatsu Rosai Hospital, Shizuoka (Japan))

1989-11-01

The functional outcome of cerebral hemodynamics in the chronic stage of juvenile hydrocephalus was determined using single photon emission computed tomography (SPECT). Five patients including three with aqueductal stenosis, one with post-meningitic hydrocephalus, and one case with hydrocephalus having developed after repair of a huge occipital encephalocele. Early images of cerebral blood flow (CBF) were obtained 25 minutes after intravenous injection of 123-I-iodoamphetamine (IMP), and late images were scanned 3 hours later. Cerebral blood volume (CBV) was also measured using {sup 99m}Tc in three patients. Twenty cases with adult communicating hydrocephalus were also investigated from the point of view of shunt effectiveness. Although there was no remarkable change in the cerebrovascular bed in the juvenile cases, CBF of the remnant brain parenchyma was good irrespective of the degree of ventricular dilatation. There was a periventricular-related IMP uptake in each case; however, it somehow matched the ventricular span. Functional outcome one to 23 years after the initial shunt operation was good in every case, despite multiple shunt revisions. Redistribution on late images had no bearing on clinical states. In adult cases, 8 patients with effective shunting demonstrated a relatively localized periventricular low perfusion, with preoperative increased cerebrospinal fluid (CSF) pressure. On the contrary, 12 patients with no improvement with or without ventricular-reduced IMP uptake, despite low CSF pressure. The present study indicates that periventricular hemodynamics may play an important role in cerebral function compromised by hydrocephalus. (J.P.N.).

Actinomyces meyeri brain abscess following dental extraction

OpenAIRE

Clancy, U; Ronayne, A; Prentice, M B; Jackson, A

2015-01-01

We describe the rare occurrence of an Actinomyces meyeri cerebral abscess in a 55-year-old woman following a dental extraction. This patient presented with a 2-day history of hemisensory loss, hyper-reflexia and retro-orbital headache, 7?days following a dental extraction for apical peridonitis. Neuroimaging showed a large left parietal abscess with surrounding empyema. The patient underwent craniotomy and drainage of the abscess. A. meyeri was cultured. Actinomycosis is a rare cause of cereb...

Regional cerebral glucose metabolism in systemic lupus erythematosus patients with major depressive disorder.

Science.gov (United States)

Saito, Tomoyuki; Tamura, Maasa; Chiba, Yuhei; Katsuse, Omi; Suda, Akira; Kamada, Ayuko; Ikura, Takahiro; Abe, Kie; Ogawa, Matsuyoshi; Minegishi, Kaoru; Yoshimi, Ryusuke; Kirino, Yohei; Ihata, Atsushi; Hirayasu, Yoshio

2017-08-15

Depression is frequently observed in patients with systemic lupus erythematosus (SLE). Neuropsychiatric SLE (NPSLE) patients often exhibit cerebral hypometabolism, but the association between cerebral metabolism and depression remains unclear. To elucidate the features of cerebral metabolism in SLE patients with depression, we performed brain 18F-fluoro-d-glucose positron emission tomography (FDG-PET) on SLE patients with and without major depressive disorder. We performed brain FDG-PET on 20 SLE subjects (5 male, 15 female). The subjects were divided into two groups: subjects with major depressive disorder (DSLE) and subjects without major depressive disorder (non-DSLE). Cerebral glucose metabolism was analyzed using the three-dimensional stereotactic surface projection (3D-SSP) program. Regional metabolism was evaluated by stereotactic extraction estimation (SEE), in which the whole brain was divided into segments. Every SLE subject exhibited cerebral hypometabolism, in contrast to the normal healthy subjects. Regional analysis revealed a significantly lower ER in the left medial frontal gyrus (p=0.0055) and the right medial frontal gyrus (p=0.0022) in the DSLE group than in the non-DSLE group. Hypometabolism in the medial frontal gyrus may be related to major depressive disorder in SLE. Larger studies are needed to clarify this relationship. Copyright © 2017 Elsevier B.V. All rights reserved.

Cerebral and non-cerebral coenurosis: on the genotypic and phenotypic diversity of Taenia multiceps.

Science.gov (United States)

Christodoulopoulos, Georgios; Dinkel, Anke; Romig, Thomas; Ebi, Dennis; Mackenstedt, Ute; Loos-Frank, Brigitte

2016-12-01

We characterised the causative agents of cerebral and non-cerebral coenurosis in livestock by determining the mitochondrial genotypes and morphological phenotypes of 52 Taenia multiceps isolates from a wide geographical range in Europe, Africa, and western Asia. Three studies were conducted: (1) a morphological comparison of the rostellar hooks of cerebral and non-cerebral cysts of sheep and goats, (2) a morphological comparison of adult worms experimentally produced in dogs, and (3) a molecular analysis of three partial mitochondrial genes (nad1, cox1, and 12S rRNA) of the same isolates. No significant morphological or genetic differences were associated with the species of the intermediate host. Adult parasites originating from cerebral and non-cerebral cysts differed morphologically, e.g. the shape of the small hooks and the distribution of the testes in the mature proglottids. The phylogenetic analysis of the mitochondrial haplotypes produced three distinct clusters: one cluster including both cerebral isolates from Greece and non-cerebral isolates from tropical and subtropical countries, and two clusters including cerebral isolates from Greece. The majority of the non-cerebral specimens clustered together but did not form a monophyletic group. No monophyletic groups were observed based on geography, although specimens from the same region tended to cluster. The clustering indicates high intraspecific diversity. The phylogenetic analysis suggests that all variants of T. multiceps can cause cerebral coenurosis in sheep (which may be the ancestral phenotype), and some variants, predominantly from one genetic cluster, acquired the additional capacity to produce non-cerebral forms in goats and more rarely in sheep.

Identification of non-cerebral cyst: Zoonotic Taenia multiceps in domestic goat in Bangladesh

Directory of Open Access Journals (Sweden)

Mohammad Omer Faruk

2017-10-01

Full Text Available Aim: This study was performed to identify the non-cerebral Taenia multiceps cyst through molecular phylogeny of the 12S rRNA gene. Materials and Methods: Eight cyst samples were collected from 385 examined slaughtered goats during October 2015-September 2016 from three slaughterhouses in Chittagong City Corporation. Cysts were removed from the thigh muscle, and scolices were collected for light microscopic examination and molecular identification. The DNA was extracted and analyzed by polymerase chain reaction using 12S rRNA gene primers. Cyst samples were also preserved in 10% buffered formalin for histopathological study. Results: T. multiceps non-cerebral cyst is 2.1% prevalent in goat in this area. Under light microscopic examination, scolex was found with four suckers and a rostellum with the double crown of 32 hooks and hooklets. Molecularly, all the samples were amplified with 12S rRNA gene fragments yielded 270 base pair amplicon. Zenker's necrosis with focal to diffuse infiltration of lymphocytes and eosinophil was also found around the cyst wall in histopathological examination. Conclusion: Although the non-cerebral form of the cysts produced by T. multiceps is genetically identical with the cerebral cyst, previously published data indicated that cerebral T. multiceps cyst is predominant in other parts of the world as well as in Bangladesh. This study showed that non-cerebral cyst is also prevalent in this country which is very important for public health concern. This study depicts an idea of non-cerebral form of zoonotic T. multiceps cyst which will be helpful in taenia cyst control and prevention.

Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

Science.gov (United States)

National Information Center for Children and Youth with Disabilities, Washington, DC.

This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

Fusion method of SAR and optical images for urban object extraction

Science.gov (United States)

Jia, Yonghong; Blum, Rick S.; Li, Fangfang

2007-11-01

A new image fusion method of SAR, Panchromatic (Pan) and multispectral (MS) data is proposed. First of all, SAR texture is extracted by ratioing the despeckled SAR image to its low pass approximation, and is used to modulate high pass details extracted from the available Pan image by means of the á trous wavelet decomposition. Then, high pass details modulated with the texture is applied to obtain the fusion product by HPFM (High pass Filter-based Modulation) fusion method. A set of image data including co-registered Landsat TM, ENVISAT SAR and SPOT Pan is used for the experiment. The results demonstrate accurate spectral preservation on vegetated regions, bare soil, and also on textured areas (buildings and road network) where SAR texture information enhances the fusion product, and the proposed approach is effective for image interpret and classification.

Microembolism after cerebral angiography

International Nuclear Information System (INIS)

Manaka, Hiroshi; Sakai, Hideki; Nagata, Izumi

2000-01-01

Acute microemboli are detected more precisely with the recently developed diffusion-weighted MR imaging (DWI). We happened to obtain 24 DWIs after 350 diagnostic cerebral angiographies in 1999. DWIs after cerebral angiographies showed bright lesions in 7 patients (28%), of whom 6 had no neurological symptoms after cerebral angiography. Seven of the 24 patients had risk factors for arteriosclerosis. Only one patient had embolic events due to angiography. Microemboli related to cerebral angiographies are inevitable in some patients. Most are silent, however, we should investigate the cause of microemboli and should make cerebral angiography safer. (author)

Wavelet-Based Feature Extraction in Fault Diagnosis for Biquad High-Pass Filter Circuit

OpenAIRE

Yuehai Wang; Yongzheng Yan; Qinyong Wang

2016-01-01

Fault diagnosis for analog circuit has become a prominent factor in improving the reliability of integrated circuit due to its irreplaceability in modern integrated circuits. In fact fault diagnosis based on intelligent algorithms has become a popular research topic as efficient feature extraction and selection are a critical and intricate task in analog fault diagnosis. Further, it is extremely important to propose some general guidelines for the optimal feature extraction and selection. In ...

Determination of cerebral metabolic patterns in dementia using positron emission tomography

International Nuclear Information System (INIS)

Kuhl, D.E.

1986-01-01

With the introduction of the Kety-Schmidt method whole brain measurements of blood flow and metabolism were first applied to normal aged and demented patients. Chronically demented patients were consistently found to have marked reductions in cerebral blood flow, oxygen utilization, and glucose utilization when dementia was severe, and lesser reductions when it was mild. Others found that cerebral blood flow, oxygen utilization, and glucose utilization were decreased in parallel in late stages of Alzheimer's disease (AD) and multiple infarct dementia (MID). The intraarterial /sup 133/Xe method has been used to determine abnormalities in regional cerebral blood flow that correlate with cognitive deficits in patients with organic dementia, mostly Alzheimer's cases. Positron emission tomography (PET) and the /sup 18/F fluorodeoxyglycose (FDG) method have been applied to small numbers of demented patients with advanced AD. In general, decreases were found in global cerebral glucose utilization, but especially in temporal and parietal cortex. Others, using PET and the /sup 15/O/sub 2/ steady-state method, found a coupled decline in global cerebral blood flow and oxygen utilization that was correlated with increasing severity of dementia in both AD and MID, but there was no increase in oxygen extraction ratio, and therefore no evidence to support the existence of a chronic ischemic brain process. In this chapter, the author reviews some of the recent findings at UCLA using PET and the method in the study of normal aging and dementing disorders

Radionuclide examination of the cerebral circulation with the 'Fucks-Knipping Gamma-Camera'

International Nuclear Information System (INIS)

Arnim, W.H. von; Schicha, H.; Becker, V.; Vyska, K.; Feinendegen, L.E.

1976-01-01

In order to analyze cerebral blood flow for diagnostic purposes, Indium 113m-DTPA was i.v. injected into seated patients, and time-activity curves were registered by a multifacet gamma camera (Fucks-Knipping) form 8 regions of interest, from the median area and from the right and left side of the head: 3 from the hemisphere, 3 from the brain stem, 2 from the large arteries of the neck. The results from 14 patients with chronic impairment of cerebral blood flow were compared with normal data from 20 healthy individuals. The time activity curves were analyzed for peak-height, mean transit time, and ratio peak to plateau height. The individual parameters were investigated for the degree of their correlation in a multiparameter system. The results from the patients indicated for the different single parameters a non-uniform response. There was also no correlation between the deviation of different parameters, between single pathological parameters and the degree and the site of blood flow impairment. On the other hand, a positive correlation was found between the number of pathological parameters and the degree of blood flow impairment irrespective of the site of its localization. Reason for this result probably is the variable location and degree of blood flow compensation by collaterals, which predominantly are expected at the cerebral base. The data indicate the potential usefulness of the application of the multiparameter analysis to quantitatively detect the degree of impairment of cerebral blood flow without regard to its topography. In this respect, the method, here described, promises to be of clinical value for non-invasive and non-hazardous diagnostic screening of cerebral blood flow. (orig.) [de

Extracting oils

Energy Technology Data Exchange (ETDEWEB)

Patart, G

1926-03-15

In the hydrogenation or extraction of by-products from organic substances at high temperatures and pressures, the gases or liquids, or both, used are those which are already heated and compressed during industrial operations such as exothermic synthesizing reactions such as the production of methanol from hydrogen and carbon monoxide in a catalytic process. Gases from this reaction may be passed upwardly through a digester packed with pine wood while liquid from the same catalytic process is passed downwardly through the material. The issuing liquid contains methanol, pine oil, acetone, isopropyl alcohol, and acetic acid. The gases contain additional hydrogen, carbon monoxide, methane, ethylene, and its homologs which are condensed upon the catalyser to liquid hydrocarbons. Petroleum oils and coal may be treated similarly.

Cerebral blood flow in patients with dementia of Alzheimer's type

DEFF Research Database (Denmark)

Postiglione, A; Lassen, N A; Holman, B L

1993-01-01

In the normal brain as well as in Alzheimer's disease (AD), regional cerebral blood flow (CBF) is coupled to metabolic demand and, therefore, changes in CBF reflect variations in neuronal metabolism. The use of radionuclide techniques, such as positron emission tomography (PET) and single photon...

Real-time digital signal recovery for a multi-pole low-pass transfer function system.

Science.gov (United States)

Lee, Jhinhwan

2017-08-01

In order to solve the problems of waveform distortion and signal delay by many physical and electrical systems with multi-pole linear low-pass transfer characteristics, a simple digital-signal-processing (DSP)-based method of real-time recovery of the original source waveform from the distorted output waveform is proposed. A mathematical analysis on the convolution kernel representation of the single-pole low-pass transfer function shows that the original source waveform can be accurately recovered in real time using a particular moving average algorithm applied on the input stream of the distorted waveform, which can also significantly reduce the overall delay time constant. This method is generalized for multi-pole low-pass systems and has noise characteristics of the inverse of the low-pass filter characteristics. This method can be applied to most sensors and amplifiers operating close to their frequency response limits to improve the overall performance of data acquisition systems and digital feedback control systems.

Extraction of uranyl sulfate with primary amine

International Nuclear Information System (INIS)

Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

1984-01-01

PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

Birth Defects: Cerebral Palsy

Science.gov (United States)

... Loss > Birth defects & other health conditions > Cerebral palsy Cerebral palsy E-mail to a friend Please fill in ... this page It's been added to your dashboard . Cerebral palsy (also called CP) is a group of conditions ...

Utility of the cerebral SPECT in schizophrenia

International Nuclear Information System (INIS)

Heuguerot, C.H.; Lopez-Lerena, J.J.; Quagliata, A.; Hermida, J.C.; Oliveira, M.C.; Anastasia, H.

2002-01-01

Objective: To compare cortical and subcortical cerebral perfusion in schizophrenics patients with normal controls, and analyze the relation to clinical patterns and neuroleptic treatment. Method: 18 patients meeting DSM-IV criteria for schizophrenia under neuroleptic treatment (except 3 cases), evaluated with clinical scales (BPRS and PANSS). The control group included 5 subjects in good health. All subjects were studied with single photon emission computed tomography (SPECT) using technetium-99 etilencisteinato (99mTc-ECD) as a tracer. Region of interest (ROI) were defined in cerebral cortex and thalamus-basal ganglia areas. The cortical cerebral blood flow was measured with a quantitative analysis, expressed as a ratio of regional tracer uptake to occipital cortex uptake. In basal ganglia and thalamus, regional blood flow was evaluated with a semiquantitative methodology, defining categories. Results: Schizophrenics patients showed a significant reduction of perfusion on a left anterior frontal cortex ('hipofrontality') and global decrease of perfusion on left hemisphere. The interhemispheric (left/right) ratio of perfusion was incremented respect control group. In thalamic-basal ganglia complex, a significant hypoperfusion was found in neuroleptic-free patients and control group. On the other hand, neuroleptic-treated patients revealed normal or increased regional blood flow in thalamus and basal ganglia. Only the clinical item 'thought disorder' had significant high correlation with perfusion on left structures (left anterior frontal, left lateral frontal, left temporo-parietal); the other items correlated with right structures. Conclusions: The findings suggest a pattern o left cerebral hypoperfusion in patients with an incremented interhemispheric ratio of cerebral blood flow. The pivotal role of thalamic and basal ganglia areas in the pathophysiology of schizophrenia and neuroleptic action was reaffirmed; apparently, perfusion in thalamic-basal ganglia

Employees with Cerebral Palsy

Science.gov (United States)

... Resources Home | Accommodation and Compliance Series: Employees with Cerebral Palsy (CP) By Eddie Whidden, MA Preface Introduction Information ... SOAR) at http://AskJAN.org/soar. Information about Cerebral Palsy (CP) What is CP? Cerebral palsy is a ...

Three-year experience with interventional neuroradiology for management of cerebral aneurysms at a single Australian centre.

Science.gov (United States)

McLaughlin, Aden; Rice, Hal; de Viliers, Laetitia; Withers, Teresa; Pearson, David; Arnell, Moira; Walters, Kerin; Czuchwicki, Sarah; Bulmer, Andrew; Winearls, James

2018-02-01

Over the last decade interventional neuroradiology (NR) has become the mainstay of managing cerebral aneurysms. The aim of our study was to review our growing experiences with interventional NR and quantify morbidity and mortality associated with these procedures. The electronic medical records of all patients admitted to the Gold Coast (University) Hospital Intensive Care Unit following subarachnoid haemorrhage (SAH) or elective interventional NR management of cerebral aneurysms between January 2012 and December 2014 were retrieved. Primary outcomes of interest were death, thromboembolic and haemorrhagic events during hospital admission. One hundred and fifty-two patients underwent interventional NR procedures for cerebral aneurysms. This consisted of 92 (60.5%) elective cases and 60 (39.5%) emergency cases following SAH. The all-cause mortality rate and the rate of thromboembolic and haemorrhagic events for the entire cohort were 5.9%, 11.2% and 7.2% respectively. Intra-procedural complications occurred in 6.6% of the entire cohort. Median length of follow-up was 448 days, with 91.6% of the entire cohort followed up. At follow-up, 64.1% of patients had no neurological deficits, 29% had mild non-specific deficits and 6.9% had significant disability. Interventional NR represents the primary treatment modality for all patients presenting to our service with cerebral aneurysm. Our results are encouraging and are comparable to published data in the international literature. Reducing the burden of thromboembolism in patients undergoing endovascular treatment of their aneurysmal disease is our main research focus currently, and we aim to improve outcomes for this patient group. © 2017 The Royal Australian and New Zealand College of Radiologists.

Parameters Affecting the Extraction Process of Jatropha curcas Oil Using a Single Screw Extruder

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Ali Nurrakhmad Siregar

2015-07-01

Full Text Available The most commonly used technique to separate oil and cake from J. curcas seeds is mechanical extraction. It uses simple tools such as a piston and a screw extruder to produce high pressure, driven by hand or by engine. A single screw extruder has one screw rotating inside the barrel and materials simultaneously flow from the feed to the die zone. The highest oil yield can be obtained by a well-designed oil press as well as finding the optimum conditions for all parameters involved during the extraction process. The influence of the parameters in a single screw extruder was studied using finite element analysis and computational fluid dynamics simulation with ANSYS POLYFLOW. The research focused on predicting the velocity, pressure and shear rate in the metering section that influenced the screw rotational speed and mass flow rate. The obtained results revealed that increasing the screw rotational speed will increase the pressure, velocity and shear rate. Meanwhile, increasing the mass flow rate results in decreasing the pressure while the velocity and shear rate remain constant.

Evoked potentials in pediatric cerebral malaria

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Minal Bhanushali

2011-12-01

Full Text Available Cortical evoked potentials (EP provide localized data regarding brain function and may offer prognostic information and insights into the pathologic mechanisms of malariamediated cerebral injury. As part of a prospective cohort study, we obtained somatosensory evoked potentials (SSEPs and brainstem auditory EPs (AEPs within 24 hours of admission on 27 consecutive children admitted with cerebral malaria (CM. Children underwent follow-up for 12 months to determine if they had any long term neurologic sequelae. EPs were obtained in 27 pediatric CM admissions. Two children died. Among survivors followed an average of 514 days, 7/25 (28.0% had at least one adverse neurologic outcome. Only a single subject had absent cortical EPs on admission and this child had a good neurologic outcome. Among pediatric CM survivors, cortical EPs are generally intact and do not predict adverse neurologic outcomes. Further study is needed to determine if alterations in cortical EPs can be used to predict a fatal outcome in CM.

Single-pass continuous-flow leach test of PNL 76-68 glass: some selected Bead Leach I results

International Nuclear Information System (INIS)

Coles, D.G.

1981-01-01

A single-pass continuous-flow leach test of PNL 76-68 glass beads (7 mm dia) was concluded after 420 days of uninterrupted operation. Variables included in the experimental matrix were flow-rate, leachant composition, and temperature. Analysis was conducted on all leachate samples for 237 Np and 239 Pu as well as a number of nonradioactive elements. Results indicated that flow-rate and leachant systematically affected the leach rate, but only slightly. Temperature effects were significant. Plutonium leach rate was lower at higher temperature suggesting that Pu sorption onto the beads was enhanced at the higher temperature. The range of leach rates for all analyzed elements (except Pu), at both temperature, at all three flow rates, and with all three leachant compositions varied only three orders of magnitude. The range of variables used in this experiment covered those expected in many proposed repository environments. The preliminary interpretation of the results also indicated that matrix dissolution may be the dominant leaching mechanism, at least for Np in bicarbonate leachant. Regardless of the leaching mechanism the importance of this study is that it bounds the effects of repository environments when the ground water is oxidizing and when it doesn't reach the waste form until the waste has cooled to ambient rock temperature

Safety of Diagnostic Cerebral and Spinal Digital Subtraction Angiography in a Developing Country: A Single-Center Experience.

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Bashir, Qasim; Ishfaq, Asim; Baig, Ammad Anwar

2018-02-01

Digital subtraction angiography (DSA) remains the gold standard imaging modality for cerebrovascular disorders. In contrast to developed countries, the safety of the procedure is not extensively reported from the developing countries. Herein, we present a retrospective analysis of the basic technique, indications, and outcomes in 286 patients undergoing diagnostic cerebral and spinal angiography in a developing country, Pakistan. A retrospective review of patient demographics, procedural technique and complication rates of 286 consecutive patients undergoing the diagnostic cerebral/spinal angiography procedure at one institution from May 2013 to December 2015 was performed. Neurological, systemic, or local complications occurring within and after 24 h of the procedure were recorded. Mean age reported for all patients was 49.7 years. Of all the 286 cases, 175 were male (61.2%) and the rest female (111, 38.8%). Cerebral DSA was performed in 279 cases (97.6%), with 7 cases of spinal DSA (2.4%). Subarachnoid hemorrhage was the most common indication for DSA accounting for 88 cases (30.8%), closely followed by stroke (26.6%) and arteriosclerotic vascular disease (23.1%). No intra- or post-procedural neurological complications of any severity were seen in any of the 286 cases. One case of asymptomatic aortic dissection was reported (0.3%) in the entire cohort of patient population. Diagnostic cerebral/spinal digital subtraction angiography was found to be safe in Pakistan, with complication rates at par with and comparable to those reported in the developed world.

Effect of interval training on cognitive functioning and cerebral oxygenation in obese patients: a pilot study.

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Drigny, Joffrey; Gremeaux, Vincent; Dupuy, Olivier; Gayda, Mathieu; Bherer, Louis; Juneau, Martin; Nigam, Anil

2014-11-01

To assess the effect of a 4-month high-intensity interval training programme on cognitive functioning, cerebral oxygenation, central haemodynamic and cardiometabolic parameters and aerobic capacity in obese patients. Cognitive functioning, cerebral oxygenation, central haemodynamic, cardiometabolic and exercise para-meters were measured before and after a 4-month high-intensity interval training programme in 6 obese patients (mean age 49 years (standard deviation 8), fat mass percentage 31 ± 7%). Body composition (body mass, total and trunk fat mass, waist circumference) and fasting insulin were improved after the programme (p attention and processing speed, was significantly improved after training (p training (p training programme in obese patients improved both cognitive functioning and cere-bral oxygen extraction, in association with improved exercise capacity and body composition.

Process analysis and modeling of a single-step lutein extraction method for wet microalgae.

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Gong, Mengyue; Wang, Yuruihan; Bassi, Amarjeet

2017-11-01

Lutein is a commercial carotenoid with potential health benefits. Microalgae are alternative sources for the lutein production in comparison to conventional approaches using marigold flowers. In this study, a process analysis of a single-step simultaneous extraction, saponification, and primary purification process for free lutein production from wet microalgae biomass was carried out. The feasibility of binary solvent mixtures for wet biomass extraction was successfully demonstrated, and the extraction kinetics of lutein from chloroplast in microalgae were first evaluated. The effects of types of organic solvent, solvent polarity, cell disruption method, and alkali and solvent usage on lutein yields were examined. A mathematical model based on Fick's second law of diffusion was applied to model the experimental data. The mass transfer coefficients were used to estimate the extraction rates. The extraction rate was found more significantly related with alkali ratio to solvent than to biomass. The best conditions for extraction efficiency were found to be pre-treatment with ultrasonication at 0.5 s working cycle per second, react 0.5 h in 0.27 L/g solvent to biomass ratio, and 1:3 ether/ethanol (v/v) with 1.25 g KOH/L. The entire process can be controlled within 1 h and yield over 8 mg/g lutein, which is more economical for scale-up.

Cerebral vessels segmentation for light-sheet microscopy image using convolutional neural networks

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Hu, Chaoen; Hui, Hui; Wang, Shuo; Dong, Di; Liu, Xia; Yang, Xin; Tian, Jie

2017-03-01

Cerebral vessel segmentation is an important step in image analysis for brain function and brain disease studies. To extract all the cerebrovascular patterns, including arteries and capillaries, some filter-based methods are used to segment vessels. However, the design of accurate and robust vessel segmentation algorithms is still challenging, due to the variety and complexity of images, especially in cerebral blood vessel segmentation. In this work, we addressed a problem of automatic and robust segmentation of cerebral micro-vessels structures in cerebrovascular images acquired by light-sheet microscope for mouse. To segment micro-vessels in large-scale image data, we proposed a convolutional neural networks (CNNs) architecture trained by 1.58 million pixels with manual label. Three convolutional layers and one fully connected layer were used in the CNNs model. We extracted a patch of size 32x32 pixels in each acquired brain vessel image as training data set to feed into CNNs for classification. This network was trained to output the probability that the center pixel of input patch belongs to vessel structures. To build the CNNs architecture, a series of mouse brain vascular images acquired from a commercial light sheet fluorescence microscopy (LSFM) system were used for training the model. The experimental results demonstrated that our approach is a promising method for effectively segmenting micro-vessels structures in cerebrovascular images with vessel-dense, nonuniform gray-level and long-scale contrast regions.

FY2016 ILAW Glass Corrosion Testing with the Single-Pass Flow-Through Method

Energy Technology Data Exchange (ETDEWEB)

Neeway, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Asmussen, Robert M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parruzot, Benjamin PG [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cordova, Elsa [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leavy, Ian I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephenson, John R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McElroy, Erin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-04-21

The inventory of immobilized low-activity waste (ILAW) produced at the Hanford Tank Waste Treatment and Immobilization Plant (WTP) will be disposed of at the near-surface, on-site Integrated Disposal Facility (IDF). When groundwater comes into contact with the waste form, the glass will corrode and radionuclides will be released into the near-field environment. Because the release of the radionuclides is dependent on the dissolution rate of the glass, it is important that the performance assessment (PA) model accounts for the dissolution rate of the glass as a function of various chemical conditions. To accomplish this, an IDF PA model based on Transition State Theory (TST) can be employed. The model is able to account for changes in temperature, exposed surface area, and pH of the contacting solution as well as the effect of silicon concentrations in solution, specifically the activity of orthosilicic acid (H4SiO4), whose concentration is directly linked to the glass dissolution rate. In addition, the IDF PA model accounts for the alkali-ion exchange process as sodium is leached from the glass and into solution. The effect of temperature, pH, H4SiO4 activity, and the rate of ion-exchange can be parameterized and implemented directly into the PA rate law model. The rate law parameters are derived from laboratory tests with the single-pass flow-through (SPFT) method. To date, rate law parameters have been determined for seven ILAW glass compositions, thus additional rate law parameters on a wider range of compositions will supplement the existing body of data for PA maintenance activities. The data provided in this report can be used by ILAW glass scientists to further the understanding of ILAW glass behavior, by IDF PA modelers to use the rate law parameters in PA modeling efforts, and by Department of Energy (DOE) contractors and decision makers as they assess the IDF PA program.

Hypothermia reduces cerebral metabolic rate and cerebral blood flow in newborn pigs

International Nuclear Information System (INIS)

Busija, D.W.; Leffler, C.W.

1987-01-01

The authors examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-μm radioactive microspheres. Regional CBF ranged from 44 to 66 ml·min -1 ·100 g -1 , and cerebral metabolic rate was 1.94 ± 0.23 ml O 2 ·100 g -1 ·min -1 during normothermia (39 degree C). Reduction of rectal temperature to 34-35 degree C decreased CBF and cerebral metabolic rate 40-50%. In another group of piglets, they examined responsiveness of the cerebral circulation to arterial hypercapnia during hypothermia. Although absolute values for normocapnic and hypercapnic CBF were reduced by hypothermia and absolute values for normocapnic and hypercapnic cerebrovascular resistance were increased, the percentage changes from control in these variables during hypercapnia were similar during normothermia and hypothermia. In another group of animals that were maintained normothermic and exposed to two episodes of hypercapnia, there was no attenuation of cerebrovascular dilation during the second episode. They conclude that hypothermia reduces CBF secondarily to a decrease in cerebral metabolic rate and that percent dilator responsiveness to arterial hypercapnia is unaltered when body temperature is reduced

Impairment of neuropsychological function in patients with hemodynamic cerebral ischemia and efficacy of bypass surgery

Energy Technology Data Exchange (ETDEWEB)

Sasoh, Masayuki [Iwate Medical Univ., Morioka (Japan). School of Medicine

1999-08-01

In order to evaluate the relation between neuropsychological functions and hemodynamic cerebral ischemia, the author analyzed neuropsychological examination and the cerebral blood flow and metabolism of patients before and after bypass surgery. Twenty-five patients were defined by clinical and laboratory criteria as suffering from hemodynamic cerebral ischemia. All patients had one or more episodes of focal cerebral ischemia due to unilateral internal carotid or middle cerebral artery occlusion. Computerized tomography scans either were normal or showed evidence of watershed infarction. Based on these criteria, superficial temporal artery-proximal middle cerebral artery anastomosis was performed. The baseline cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen (CMRO{sub 2}) and cerebrovascular reserve capacity (CVRC) were studied using positron emission computerized tomography (PET) and the acetazolamide test. Neuropsychological evaluations including Hasegawa Dementia Scale-Revised, Mini-Mental State and Wechsler Adult Intelligence Scale-Revised (WAIS-R), and PET study were completed one month after the last ischemic event and 3-6 months after the operation. A significant negative correlation was observed between OEF and neuropsychological functions. Postoperative neuropsychological functions showed significant improvement. Significant correlations were observed for {delta}WAIS-R (preoperative WAIS-R postoperative WAIS-R) versus preoperative CMRO{sub 2} (r=0.52), for {delta}WAIS-R versus preoperative OEF (r=0.47). In view of these findings, the author concludes that elevation of OEF impairs neuropsychological functions and bypass surgery improves neuropsychological functions in patients with normal CMRO{sub 2} and elevated OEF. (author)

Assessment of changes in regional cerebral blood flow in patients with major depression using the 99mTc-HMPAO single photon emission tomography method

International Nuclear Information System (INIS)

Yazici, K.; Kapucu, Oe.; Erbas, B.; Varoglu, E.; Guelec, C.; Bekdik, C.F.; Hacettepe Univ., Ankara

1992-01-01

Regional cerebral blood flow was investigated in 14 patients with major depression diagnosed according to the DSM-III-R criteria (six patients with single and eight patients with recurrent episodes) and in ten healthy volunteers. The mean ages of the patients and the controls were 33.5±2.7 and 31.6±2.6 years, respectively. The severity of the depression was assessed using the 17-item Hamiltonian Depression Scale (mean: 23.2±1.5). None of the patients was under medication. After administration of 500 MBq technetium-99m hexamethylpropylene amine oxime, a single photon emission tomography study was performed and then transaxial, sagittal and coronal slices were obtained. For the semiquantitative analysis of the data, the ratios of the mean counts/pixel to the whole slice were calculated for 24 regions on three consecutive transaxial slices in the orbitomeatal plane. Additionally, left/right and frontal/occipital ratios were calculated. Both sides of the temporal region had a significantly decreased cerebral blood flow (CBF) when compared to the controls. The left/right ratio of the prefrontal region was also significantly lower in the patients than in the controls. The Hamilton score had a negative correlation with blood flow in the anterofrontal and left prefrontal regions. According to our results, regional CBF seems to be decreased in the left prefrontal and in both temporal regions in major depression. The severity of depression is correlated with the reduction in CBF in the regions of the anterofrontal and left prefrontal cortex. (orig.)

Regional effects of craniotomy on cerebral circulation and metabolism

International Nuclear Information System (INIS)

Abumiya, Takeo; Sayama, Ichiro; Asakura, Ken; Hadeishi, Hiromu; Mizuno, Makoto; Suzuki, Akifumi; Yasui, Nobuyuki; Shishido, Fumio; Uemura, Kazuo

1990-01-01

Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO 2 ), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on un-ruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15 O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO 2 or CBV. The increase in OEF was caused by decrease of O 2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO 2 , in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO 2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used. (author)

Regional cerebral blood flow changes in schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-( sup 123 I)iodoamphetamine (IMP)

Energy Technology Data Exchange (ETDEWEB)

Kanaya, Toshinori (Hiroshima Univ. (Japan). School of Medicine)

1989-06-01

Regional cerebral blood flows (rCBF) were measured in patients with schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-({sup 123}I)iodoamphetamine (IMP). The subjects were 20 patients with shizophrenia, 32 patients with endogenous depression and 20 normal controls. The patients with depression were divided into 3 groups; unmedicated, medicated patients in depressive state, and medicated patients in remited state. The rCBF were calculated by the corticocerebellar ratio (CCR), which was expressed as a ratio of activity per pixel in cortical regions of interest to the activity per pixel in the cerebellum. The results were as follows. In patients with schizophrenia the marked decrease in rCBF in bilateral frontal regions and the lower rCBF in the left than in the right hemisphere were observed. There was no significant correlation between the mean rCBF and BPRS (Brief Psychiatric Rating Scale) in patients with shizophrenia. In patients with depression the decrease in rCBF in overall cerebral regions and the lower rCBF in the left than in the right hemisphere were observed in both groups in depressive state. These changes were normalized in remited state, though there was no significant difference in rCBF between on medication and off medication. There was significantly negative correlation between the mean rCBF and Hamilton Depression Rating Scale in patients with depression. These results support the previously reported 'hypofrontality' and the left hemispheric dysfunction in shizophrenia. In depressive patients the overall cerebral dysfunction was revealed more remarkablly in the left than in the right hemisphere, which was normalized following the improvement of depressive symptoms. Furthermore, it was suggested that the applications of IMP-SPECT could be useful for the diagnosis and research for the cerebral function in mental illness. (author) 59 refs.

Simulation of the High-Pass Filter for 56MHz Cavity for RHIC

International Nuclear Information System (INIS)

Wu, Q.; Ben-Zvi, I.

2010-01-01

The 56MHz Superconducting RF (SRF) cavity for RHIC places high demands High Order Mode (HOM) damping, as well as requiring a high field at gap with fundamental mode frequency. The damper of 56MHz cavity is designed to extract all modes to the resistance load outside, including the fundamental mode. Therefore, the circuit must incorporate a high-pass filter to reflect back the fundamental mode into the cavity. In this paper, we show the good frequency response map obtained from our filter's design. We extract a circuit diagram from the microwave elements that simulate well the frequency spectrum of the finalized filter. We also demonstrate that the power dissipation on the filter over its frequency range is small enough for cryogenic cooling.

Predictive thermodynamic models for liquid--liquid extraction of single, binary and ternary lanthanides and actinides

International Nuclear Information System (INIS)

Hoh, Y.C.

1977-03-01

Chemically based thermodynamic models to predict the distribution coefficients and the separation factors for the liquid--liquid extraction of lanthanides-organophosphorus compounds were developed by assuming that the quotient of the activity coefficients of each species varies slightly with its concentrations, by using aqueous lanthanide or actinide complexes stoichiometric stability constants expressed as its degrees of formation, by making use of the extraction mechanism and the equilibrium constant for the extraction reaction. For a single component system, the thermodynamic model equations which predict the distribution coefficients, are dependent on the free organic concentration, the equilibrated ligand and hydrogen ion concentrations, the degree of formation, and on the extraction mechanism. For a binary component system, the thermodynamic model equation which predicts the separation factors is the same for all cases. This model equation is dependent on the degrees of formation of each species in their binary system and can be used in a ternary component system to predict the separation factors for the solutes relative to each other

Hyperventilation, cerebral perfusion, and syncope

DEFF Research Database (Denmark)

Immink, R V; Pott, F C; Secher, N H

2014-01-01

dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2...... the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...... cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established....

Large arteriolar component of oxygen delivery implies a safe margin of oxygen supply to cerebral tissue.

Science.gov (United States)

Sakadžić, Sava; Mandeville, Emiri T; Gagnon, Louis; Musacchia, Joseph J; Yaseen, Mohammad A; Yucel, Meryem A; Lefebvre, Joel; Lesage, Frédéric; Dale, Anders M; Eikermann-Haerter, Katharina; Ayata, Cenk; Srinivasan, Vivek J; Lo, Eng H; Devor, Anna; Boas, David A

2014-12-08

What is the organization of cerebral microvascular oxygenation and morphology that allows adequate tissue oxygenation at different activity levels? We address this question in the mouse cerebral cortex using microscopic imaging of intravascular O2 partial pressure and blood flow combined with numerical modelling. Here we show that parenchymal arterioles are responsible for 50% of the extracted O2 at baseline activity, and the majority of the remaining O2 exchange takes place within the first few capillary branches. Most capillaries release little O2 at baseline acting as an O2 reserve that is recruited during increased neuronal activity or decreased blood flow. Our results challenge the common perception that capillaries are the major site of O2 delivery to cerebral tissue. The understanding of oxygenation distribution along arterio-capillary paths may have profound implications for the interpretation of blood-oxygen-level dependent (BOLD) contrast in functional magnetic resonance imaging and for evaluating microvascular O2 delivery capacity to support cerebral tissue in disease.

Regional cerebral perfusion in cardiovascular reflex syncope

International Nuclear Information System (INIS)

Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.

1997-01-01

Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

Spontaneous regression of cerebral arteriovenous malformations: clinical and angiographic analysis with review of the literature

International Nuclear Information System (INIS)

Lee, S.K.; Vilela, P.; Willinsky, R.; TerBrugge, K.G.

2002-01-01

Spontaneous regression of cerebral arteriovenous malformation (AVM) is rare and poorly understood. We reviewed the clinical and angiographic findings in patients who had spontaneous regression of cerebral AVMs to determine whether common features were present. The clinical and angiographic findings of four cases from our series and 29 cases from the literature were retrospectively reviewed. The clinical and angiographic features analyzed were: age at diagnosis, initial presentation, venous drainage pattern, number of draining veins, location of the AVM, number of arterial feeders, clinical events during the interval period to thrombosis, and interval period to spontaneous thrombosis. Common clinical and angiographic features of spontaneous regression of cerebral AVMs are: intracranial hemorrhage as an initial presentation, small AVMs, and a single draining vein. Spontaneous regression of cerebral AVMs can not be predicted by clinical or angiographic features, therefore it should not be considered as an option in cerebral AVM management, despite its proven occurrence. (orig.)

[Regional cerebral oxygen saturation as a marker of hemodynamic state following cardiac surgery].

Science.gov (United States)

García-Hernández, J A; Aldemira-Liz, A; Martínez-López, A I; Cayuela, A; Charlo-Molina, M T; Cano-Franco, J; Loscertales-Abril, M

2013-10-01

Regional cerebral oxygen saturation (rSO₂) is a measure of the general state of perfusion and oxygenation. We aim to analyze the relationship between this and various hemodynamic and respiratory parameters. Forty-three patients, operated on between October 2011 and July 2012, were included in this prospective observational descriptive study. The following parameters were measured: mean arterial pressure, both arterial and central venous oxygen saturation and partial pressures of oxygen and carbon dioxide, and lactate levels. From these parameters, the oxygenation index and the oxygen extraction ratio were calculated. These measurements were studied to evaluate whether rSO₂ correlated significantly with the other parameters. The average age and weight of the patients were 27.3 months and 9.2 kg, respectively. The rSO₂ correlated positively with both central venous oxygen saturation (r=0.73, P 0.4) between the rSO₂ and central venous oxygen saturation, and between the rSO₂ and oxygen extraction ratio. Regional cerebral oxygen saturation correlates well with hemodynamic parameters - mean arterial pressure, venous saturation, and the tissue oxygen extraction. However, it does not correlate with respiratory parameters. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Studies on asymptomatic cerebral ischemia in coronary heart disease with special reference to evaluation of postural changes in cerebral blood flow with {sup 99m}Tc-ECD brain SPECT

Energy Technology Data Exchange (ETDEWEB)

Sinozaki, Hideko [Teikyo Univ., Tokyo (Japan). Faculty of Medicine

2001-03-01

Postural changes in cerebral blood flow in patients with coronary heart disease (CHD) were evaluated with SPECT to detect asymptomaic cerebral ischemia (ACI). {sup 99m}Tc-ECD was used as a tracer. We developed a new analysis system for the processing of multiple images, making it possible to avoid the spatial shift in ROIs in different positions. The severity of ACI was classified into 3 groups based on SPECT findings in the supine position: group 1 without any abnormalities in cerebral perfusion, group 2 with a single perfusion defect, and group 3 with a number of perfusion defects. No cerebral siteobserved in any group showed a significant difference between the supine and upright positions in cerebral perfusion. Each group in each position, however, revealed a consistent perfusion pattern characterized by a significant decrease in perfusion in the occipital, temporal and frontal lobes. Moreover, the decrease in the latter two sites was significantly greater than in the former site. Concerning clinical profiles, hypertension and the thickness of the intima and media complex (TIMC) of the common carotid artery significantly correlated with the severity of ACI. Furthermore, in multiple regression analysis, only TIMC was identified as a significant determinant of ACI. In conclusion, cerebral blood flow determined with {sup 99m}Tc-ECD SPECT could accurately detect ACI in patients with CHD. (author)

Heavy metals extractability in a soil amended with sewage sludge Extractabilidade de metais pesados em um solo tratado com lodo de esgoto

Directory of Open Access Journals (Sweden)

Giuliano Marchi

2009-10-01

Full Text Available Few investigations have been carried out about the comparison of desorption rate and amount of heavy metals extracted successively by organic acid mixtures mimicking the rhizosphere and routine extractants in sewage sludge-amended soils. Extractions of Zn, Cd, Ni, Cr, and Cu were performed in samples of a sewage sludge-amended soil using seven extractants: four organic acid mixtures and three routine extractants (DTPA, Mehlich-I, and ammonium acetate. Results from single pass extractions, in which the extractable metal contents were determined by simply extracting the soil a single time, as well as from 15 successive extractions, in which the solid residues of the first extraction was successively extracted 14 additional times, of heavy metals were analyzed. The extractability of heavy metals in a single pass extraction was, in general, as follows: Mehlich-I > DTPA > organic acids > NH4OAc. The highest rates of extraction followed the general order: DTPA > Mehlich-I > organic acids > NH4OAc. While Mehlich-I presented the highest extractability of heavy metals among studied extractants, DTPA showed a high extractability of Zn, Cd, Ni, and Cu in a single extraction as well as the highest rates of extraction among the studied extractants. The transfer of heavy metals from soil to organic acid solutions is slower than to DTPA and Mehlich-I extractants.Poucos trabalhos têm sido realizados sobre a comparação da taxa de dessorção e da quantidade de metais extraídos sucessivamente por misturas de ácidos orgânicos que imitam a composição da rizosfera e por extratores usados na rotina em amostras de solo tratado com lodo de esgoto. Extrações de Zn, Cd, Ni, Cr e Cu foram realizadas em amostras de um solo de carga variável tratado com lodo de esgoto usando-se sete extratores: quatro misturas com ácidos orgânicos e três extratores usados na rotina (DTPA, Mehlich-I e acetato de amônio. Os resultados para uma única extração, em que o conte

Pharmacokinetic Study of Piracetam in Focal Cerebral Ischemic Rats.

Science.gov (United States)

Paliwal, Pankaj; Dash, Debabrata; Krishnamurthy, Sairam

2018-04-01

Cerebral ischemia affects hepatic enzymes and brain permeability extensively. Piracetam was investigated up to phase III of clinical trials and there is lack of data on brain penetration in cerebral ischemic condition. Thus, knowledge of the pharmacokinetics and brain penetration of piracetam during ischemic condition would aid to improve pharmacotherapeutics in ischemic stroke. Focal cerebral ischemia was induced by middle cerebral artery occlusion for 2 h in male Wistar rats followed by reperfusion. After 24 h of middle cerebral artery occlusion or 22 h of reperfusion, piracetam was administered for pharmacokinetic, brain penetration, and pharmacological experiments. In pharmacokinetic study, blood samples were collected at different time points after 200-mg/kg (oral) and 75-mg/kg (intravenous) administration of piracetam through right external jugular vein cannulation. In brain penetration study, the cerebrospinal fluid, systemic blood, portal blood, and brain samples were collected at pre-designated time points after 200-mg/kg oral administration of piracetam. In a separate experiment, the pharmacological effect of the single oral dose of piracetam in middle cerebral artery occlusion was assessed at a dose of 200 mg/kg. All the pharmacokinetic parameters of piracetam including area under curve (AUC 0-24 ), maximum plasma concentration (C max ), time to reach the maximum plasma concentration (t max ), elimination half-life (t 1/2 ), volume of distribution (V z ), total body clearance, mean residence time, and bioavailability were found to be similar in ischemic stroke condition except for brain penetration. Piracetam exposure (AUC 0-2 ) in brain and CSF were found to be 2.4- and 3.1-fold higher, respectively, in ischemic stroke compared to control rats. Piracetam significantly reduced infarct volume by 35.77% caused by middle cerebral artery occlusion. There was no change in the pharmacokinetic parameters of piracetam in the ischemic stroke model except for

Multi-staging for extraction of cesium from nitric acid by a single liquid-liquid countercurrent centrifugal extractor with Taylor vortices

International Nuclear Information System (INIS)

Nakase, Masahiko; Kinuhata, Hiroshi; Takeshita, Kenji

2013-01-01

Fission products that emit considerable decay heat and radioactivity, such as 137 Cs, have a large impact on waste management. Small and high-performance extractor is desirable for separating such nuclei. In this study, we implemented the continuous extraction of Cs from nitric acid in a single liquid-liquid countercurrent centrifugal extractor with Taylor Vortices by calix arene-bis(t-octylbenzo-crown-6)(BOBCalixC6) as an extractant with trioctylamine(TOA) as a suppressant and with 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) as a phase modifier. Because of slow extraction kinetics of this process, extraction with multiple theoretical stages by just replacing conventional extractors into the single centrifugal extractor is difficult. Hence, we improved the dispersion of organic phase by an inner rotor made of lipophilic epoxy resin and elevating the solution temperature to lower the viscosity. Higher temperature was not appropriate from the aspect of chemical equilibrium in this process, but extraction with multiple theoretical stages was found to be possible. (author)

Development of SiC Nanoparticles and Second Phases Synergistically Reinforced Mg-Based Composites Processed by Multi-Pass Forging with Varying Temperatures

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Kaibo Nie

2018-01-01

Full Text Available In this study, SiC nanoparticles were added into matrix alloy through a combination of semisolid stirring and ultrasonic vibration while dynamic precipitation of second phases was obtained through multi-pass forging with varying temperatures. During single-pass forging of the present composite, as the deformation temperature increased, the extent of recrystallization increased, and grains were refined due to the inhibition effect of the increasing amount of dispersed SiC nanoparticles. A small amount of twins within the SiC nanoparticle dense zone could be found while the precipitated phases of Mg17Al12 in long strips and deformation bands with high density dislocations were formed in the particle sparse zone after single-pass forging at 350 °C. This indicated that the particle sparse zone was mainly deformed by dislocation slip while the nanoparticle dense zone may have been deformed by twinning. The yield strength and ultimate tensile strength of the composites were gradually enhanced through increasing the single-pass forging temperature from 300 °C to 400 °C, which demonstrated that initial high forging temperature contributed to the improvement of the mechanical properties. During multi-pass forging with varying temperatures, the grain size of the composite was gradually decreased while the grain size distribution tended to be uniform with reducing the deformation temperature and extending the forging passes. In addition, the amount of precipitated second phases was significantly increased compared with that after multi-pass forging under a constant temperature. The improvement in the yield strength of the developed composite was related to grain refinement strengthening and Orowan strengthening resulting from synergistical effect of the externally applied SiC nanoparticles and internally precipitated second phases.

Decreased cerebral blood flow in renal transplant recipients

International Nuclear Information System (INIS)

Kamano, Chisako; Komaba, Yuichi; Sakayori, Osamu; Iino, Yasuhiko; Katayama, Yasuo

2002-01-01

We performed single-photon emission computed tomography (SPECT) to investigate the influence of renal transplantation on cerebral blood flow (CBF). Fifteen renal transplant recipients and twelve normal subjects underwent cerebral SPECT with N-isopropyl-p-[ 123 I] iodoamphetamine ( 123 I-IMP). All transplant recipients received prednisolone and cyclosporine (CyA). Regional CBF (rCBF) was measured by defining regions of interest in the cerebral cortex, deep white matter, striatum, thalamus, and cerebellum. In transplant recipients, correlations to the mean overall cortical CBF were assessed using the interval from transplantation to measurement of SPECT, as well as the serum creatinine concentration. Moreover, to investigate the influence of CyA on CBF, the correlation between mean overall cortical CBF and CyA trough concentrations was assessed. In all regions, CBF in renal transplant recipients was significantly lower than in normal subjects. No significant correlation was seen between serum creatinine, interval from transplantation, or CyA trough concentrations and mean overall cortical CBF. Renal transplant recipients demonstrated a decrease in CBF, that can have an associated secondary pathology. Therefore, renal transplant recipients may benefit from post-operative MRI or CT. (author)

Carbon Dioxide Fluctuations Are Associated with Changes in Cerebral Oxygenation and Electrical Activity in Infants Born Preterm.

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Dix, Laura Marie Louise; Weeke, Lauren Carleen; de Vries, Linda Simone; Groenendaal, Floris; Baerts, Willem; van Bel, Frank; Lemmers, Petra Maria Anna

2017-08-01

To evaluate the effects of acute arterial carbon dioxide partial pressure changes on cerebral oxygenation and electrical activity in infants born preterm. This retrospective observational study included ventilated infants born preterm with acute fluctuations of continuous end-tidal CO 2 (etCO 2 ) as a surrogate marker for arterial carbon dioxide partial pressure, during the first 72 hours of life. Regional cerebral oxygen saturation and fractional tissue oxygen extraction were monitored with near-infrared spectroscopy. Brain activity was monitored with 2-channel electroencephalography. Spontaneous activity transients (SATs) rate (SATs/minute) and interval between SATs (in seconds) were calculated. Ten-minute periods were selected for analysis: before, during, and after etCO 2 fluctuations of ≥5  mm Hg. Thirty-eight patients (mean ± SD gestational age of 29 ± 1.8 weeks) were included, with 60 episodes of etCO 2 increase and 70 episodes of etCO 2 decrease. During etCO 2 increases, brain oxygenation increased (regional cerebral oxygen saturation increased, fractional tissue oxygen extraction decreased; P carbon dioxide partial pressure that may be harmful to the neonatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Cerebral blood flow and oxygen metabolism in the Rett syndrome

International Nuclear Information System (INIS)

Yoshikawa, Hideto; Fueki, Noboru; Suzuki, Hisaharu; Sakuragawa, Norio; Iio, Masaaki

1992-01-01

Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO 2 ) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO 2 were lower than those for the controls, which may indicate the loss of of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome. (author)

In vivo imaging of cerebral energy metabolism with two-photon fluorescence lifetime microscopy of NADH.

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Yaseen, Mohammad A; Sakadžić, Sava; Wu, Weicheng; Becker, Wolfgang; Kasischke, Karl A; Boas, David A

2013-02-01

Minimally invasive, specific measurement of cellular energy metabolism is crucial for understanding cerebral pathophysiology. Here, we present high-resolution, in vivo observations of autofluorescence lifetime as a biomarker of cerebral energy metabolism in exposed rat cortices. We describe a customized two-photon imaging system with time correlated single photon counting detection and specialized software for modeling multiple-component fits of fluorescence decay and monitoring their transient behaviors. In vivo cerebral NADH fluorescence suggests the presence of four distinct components, which respond differently to brief periods of anoxia and likely indicate different enzymatic formulations. Individual components show potential as indicators of specific molecular pathways involved in oxidative metabolism.

Cerebral blood flow and metabolism in multi-infarct dementia

International Nuclear Information System (INIS)

Ujike, Takashi; Terashi, Akiro; Soeda, Toshiyuki; Kitamura, Shin; Kato, Toshiaki; Iio, Masaaki.

1985-01-01

Cerebral blood flow and oxygen metabolism were studied in three aged normal volunteers and 10 patients with multi-infarct dementia (MID) by Positron Emission Tomography using O-15. The diagnosis of MID was done according to the Loeb's modified ischemic score and X-ray CT findings. The MID patients, whose X-ray CT showed localized low density areas in the subcortical white matter and basal ganglia and thalamus, were studied. No occulusion was observed at anterior cerebral artery and/or middle cerebral artery on cerebral angiography. All cases of MID were mild dementias. Regional CBF, rOEF and rCMRO 2 were measured by the steady state technique described by Terry Jones et al. The values of rCBF in MID patients were significantly low compared with those of aged normal subjects in frontal, temporal, occipital, parietal cortices and thalamus. The values of CMRO 2 in MID were significantly low in frontal, temporal, occipital cortices and thalamus compared with normal subjects'. The OEF was 0.46 in aged normal subjects, and 0.52 in MID patients. The MID patients in the early stage of dementia showed the increased oxygen extraction fraction, and this fact suggests that ischemia is a significant pathogenic mechanism in the production and progression of multi-infarct dementia. The decrease of CBF and CMRO 2 in MID compared from normal subjects' were most remarkable in frontal cortex. The impairment of mental functions in MID should be caused by the decreased neuronal activities in frontal association cortex. (author)

Manual Aspiration Thrombectomy in Patients with Acute Stroke-Related Calcified Cerebral Emboli.

Science.gov (United States)

Koh, Esther; Kwak, Hyo Sung; Chung, Gyung-Ho

2017-10-01

The aim of this study was to evaluate the effectiveness of mechanical aspiration thrombectomy (MAT) in patients with acute ischemic stroke from calcified cerebral emboli. Procedural results were reviewed for acute stroke patients with clinically neurological deficits who underwent recanalization from October 2012 through September 2015. Initial imaging studies and cerebral angiography were analyzed. Of the total number of patients with acute stroke, 5 patients were confirmed to have acute ischemic stroke by calcified cerebral emboli. On initial brain computed tomographic imaging, all patients showed small, dense single calcifications in the middle cerebral artery with no definitive ischemic low-density lesions (M1: 3, M2: 2, mean size: 4.8 mm). All patients had angiographic findings of filling defects from calcified emboli. Four patients had good collateral flow and two had continuous distal flow. All patients underwent MAT using a Penumbra catheter (Penumbra Inc., Alameda, CA). MAT did not remove calcified emboli in all patients. Two patients with good collateral flow had favorable functional outcomes (modified Rankin Scale score ≤2). Four patients had diffuse calcification in the aortic arch, carotid artery, and aortic valve. Cerebral angiography supports a diagnosis of stroke when calcified cerebral emboli have contrast-filling defects and a degree of vascular occlusion. However, in this study, MAT was not an effective treatment for patients with calcified cerebral emboli because of hardness of the calcified plaque and packing into the arterial lumen. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Cerebral vasculitis

International Nuclear Information System (INIS)

Greenan, T.J.; Grossman, R.I.

1990-01-01

This paper reviews retrospectively MR, CT, and angiographic findings in patients with cerebral vasculitis in order to understand the strengths and weaknesses of the various imaging modalities, as well as the spectrum of imaging abnormalities in this disease entity. Studies were retrospectively reviewed in 12 patients with cerebral vasculitis proved by means of angiography and/or brain biopsy

Cerebral uptake and retention of 99Tcsup(m)-hexamethylpropyleneamine oxime (99Tcsup(m)-HM-PAO)

International Nuclear Information System (INIS)

Holmes, R.A.; Chaplin, S.B.; Royston, K.G.; Missouri Univ., Columbia

1985-01-01

A new radiopharmaceutical, 99 Tcsup(m)-hexamethylpropyleneamine oxime ( 99 Tcsup(m)-HM-PAO) is described. This agent displays considerable promise for imaging cerebral blood flow. In studies in rats and one human volunteer, 99 Tcsup(m)-HM-PAO demonstrates good brain uptake, prolonged retention of activity in the brain, and slow regional redistribution. These properties suggest that this new radiopharmaceutical is ideal for single photon emission tomographic (SPECT) imaging of cerebral blood flow. (author)

[Cerebral protection].

Science.gov (United States)

Cattaneo, A D

1993-09-01

Cerebral protection means prevention of cerebral neuronal damage. Severe brain damage extinguishes the very "human" functions such as speech, consciousness, intellectual capacity, and emotional integrity. Many pathologic conditions may inflict injuries to the brain, therefore the protection and salvage of cerebral neuronal function must be the top priorities in the care of critically ill patients. Brain tissue has unusually high energy requirements, its stores of energy metabolites are small and, as a result, the brain is totally dependent on a continuous supply of substrates and oxygen, via the circulation. In complete global ischemia (cardiac arrest) reperfusion is characterized by an immediate reactive hyperemia followed within 20-30 min by a delayed hypoperfusion state. It has been postulated that the latter contributes to the ultimate neurologic outcome. In focal ischemia (stroke) the primary focus of necrosis is encircled by an area (ischemic penumbra) that is underperfused and contains neurotoxic substances such as free radicals, prostaglandins, calcium, and excitatory neurotransmitters. The variety of therapeutic effort that have addressed the question of protecting the brain reflects their limited success. 1) Barbiturates. After an initial enthusiastic endorsement by many clinicians and years of vigorous controversy, it can now be unequivocally stated that there is no place for barbiturate therapy following resuscitation from cardiac arrest. One presumed explanation for this negative statement is that cerebral metabolic suppression by barbiturates (and other anesthetics) is impossible in the absence of an active EEG. Conversely, in the event of incomplete ischemia EEG activity in usually present (albeit altered) and metabolic suppression and hence possibly protection can be induced with barbiturates. Indeed, most of the animal studies led to a number of recommendations for barbiturate therapy in man for incomplete ischemia. 2) Isoflurane. From a cerebral

Dynamic digitized cerebral parenchymography

International Nuclear Information System (INIS)

Theron, J.; Alachkar, F.; Nelson, M.; Mazia, D.

1992-01-01

Aortic arch injections centred on the head have been performed routinely in patients with cerebral ischaemia. Digital angiograms with modified windowing (low and narrow) have been used. This 'cerebral' arch injection allows much improved analysis of the cerebral parenchymal vascularization, giving better understanding of hemispheric ischaemia and making the decision about revascularization more rational. (orig.)

What is cerebral small vessel disease?

International Nuclear Information System (INIS)

Onodera, Osamu

2011-01-01

An accumulating amount of evidence suggests that the white matter hyperintensities on T 2 weighted brain magnetic resonance imaging predict an increased risk of dementia and gait disturbance. This state has been proposed as cerebral small vessel disease, including leukoaraiosis, Binswanger's disease, lacunar stroke and cerebral microbleeds. However, the concept of cerebral small vessel disease is still obscure. To understand the cerebral small vessel disease, the precise structure and function of cerebral small vessels must be clarified. Cerebral small vessels include several different arteries which have different anatomical structures and functions. Important functions of the cerebral small vessels are blood-brain barrier and perivasucular drainage of interstitial fluid from the brain parenchyma. Cerebral capillaries and glial endfeet, take an important role for these functions. However, the previous pathological investigations on cerebral small vessels have focused on larger arteries than capillaries. Therefore little is known about the pathology of capillaries in small vessel disease. The recent discoveries of genes which cause the cerebral small vessel disease indicate that the cerebral small vessel diseases are caused by a distinct molecular mechanism. One of the pathological findings in hereditary cerebral small vessel disease is the loss of smooth muscle cells, which is an also well-recognized finding in sporadic cerebral small vessel disease. Since pericytes have similar character with the smooth muscle cells, the pericytes should be investigated in these disorders. In addition, the loss of smooth muscle cells may result in dysfunction of drainage of interstitial fluid from capillaries. The precise correlation between the loss of smooth muscle cells and white matter disease is still unknown. However, the function that is specific to cerebral small vessel may be associated with the pathogenesis of cerebral small vessel disease. (author)

Sleep apnea termination decreases cerebral blood volume: a near-infrared spectroscopy case study

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Virtanen, Jaakko; Noponen, Tommi; Salmi, Tapani; Toppila, Jussi; Meriläinen, Pekka

2009-07-01

Medical near-infrared spectroscopy (NIRS) can be used to estimate cerebral haemodynamic changes non-invasively. Sleep apnea is a common sleep disorder where repetitive pauses in breathing decrease the quality of sleep and exposes the individual to various health problems. We have measured oxygenated and deoxygenated haemoglobin concentration changes during apneic events in sleep from the forehead of one subject using NIRS and used principal component analysis to extract extracerebral and cortical haemodynamic changes from NIRS signals. Comparison of NIRS signals with EEG, bioimpedance, and pulse oximetry data suggests that termination of apnea leads to decreases in cerebral blood volume and flow that may be related to neurological arousal via neurovascular coupling.

Small, smooth, nonmobile cardiac myxoma detected by transesophageal echocardiography following recurrent cerebral infarction: a case report.

Science.gov (United States)

Saito, Yuki; Aizawa, Yoshihiro; Monno, Koyuru; Nagashima, Koichi; Kurokawa, Sayaka; Osaka, Shunji; Akimoto, Takayoshi; Kamei, Satoshi; Tanaka, Masashi; Hirayama, Atsushi

2017-05-10

Cardiac myxoma is known to cause repeated events of cerebral embolism. Soft and irregularly shaped myxomas with high mobility are associated with a higher occurrence of cerebral embolism. In contrast, nonmobile cardiac myxomas with a round regular shape are rarely considered to be a cause of cerebral embolism. In this case, we present a patient with recurrent cerebral embolism associated with a small and nonmobile cardiac myxoma of round regular shape. A 76-year-old Japanese man presented to our hospital with weakness in his right upper extremity. He had a history of right frontal lobe infarction in the previous month. T2-weighted magnetic resonance imaging revealed an area of hyperintensity in the left precentral gyrus, indicating acute cerebral infarction. Transthoracic echocardiography revealed normal left ventricular function and no abnormalities. However, transesophageal echocardiography showed a small and nonmobile left atrial tumor with round regular shape attached to the ostium secundum of the atrial septum. Based on these findings, we diagnosed recurrent cerebral infarction due to embolization caused by left atrial myxoma, and cardiac tumor extraction was performed on hospitalization day 36. The excised tumor measured 0.6 × 0.6 × 0.5 cm and was diagnosed as cardiac myxoma by histologic examination. Even small and nonmobile cardiac myxomas with a round regular shape may cause recurrent cerebral infarction. The diagnosis of this type of atrial myxoma is elusive and transesophageal echocardiography was an effective method of detection. In a clinical situation, this type of cardiac myxoma may be overlooked as a cause of cerebral infarction.

Neuroprotective potential of Citrullus lanatus seed extract and ...

African Journals Online (AJOL)

Mercury chloride toxicity continues to be relevant in the advent of increased interest in mining activity in Nigeria. The neuroprotective potential of Citrullus lanatus seed extract (CLSE) (Watermelon seed) and vitamin E (VIT E) on mercury chloride intoxication on the frontal cerebral cortex of male rats was investigated.

Chaos-pass filtering in injection-locked semiconductor lasers

International Nuclear Information System (INIS)

Murakami, Atsushi; Shore, K. Alan

2005-01-01

Chaos-pass filtering (CPF) of semiconductor lasers has been studied theoretically. CPF is a phenomenon which occurs in laser chaos synchronization by injection locking and is a fundamental technique for the extraction of messages at the receiver laser in chaotic communications systems. We employ a simple theory based on driven damped oscillators to clarify the physical background of CPF. The receiver laser is optically driven by injection from the transmitter laser. We have numerically investigated the response characteristics of the receiver when it is driven by periodic (message) and chaotic (carrier) signals. It is thereby revealed that the response of the receiver laser in the two cases is quite different. For the periodic drive, the receiver exhibits a response depending on the signal frequency, while the chaotic drive provides a frequency-independent synchronous response to the receiver laser. We verify that the periodic and chaotic drives occur independently in the CPF response, and, consequently, CPF can be clearly understood in the difference of the two drives. Message extraction using CPF is also examined, and the validity of our theoretical explanation for the physical mechanism underlying CPF is thus verified

Collector Efficiency in Downward-Type Double-Pass Solar Air Heaters with Attached Fins and Operated by External Recycle

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Chii-Dong Ho

2012-07-01

Full Text Available The collector efficiency in a downward-type double-pass external-recycle solar air heater with fins attached on the absorbing plate has been investigated theoretically. Considerable improvement in collector efficiency is obtainable if the collector is equipped with fins and the operation is carried out with an external recycle. Due to the recycling, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperature difference of heat transfer, while the attached fins provide an enlarged heat transfer area. The order of performances in the devices of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

Positron emission tomography of hepatic first-pass metabolism of ammonia in pig

International Nuclear Information System (INIS)

Keiding, S.; Munk, O.L.; Roelsgaard, K.; Bender, D.; Bass, L.

2001-01-01

Hepatic first-pass metabolism plays a key role in metabolic regulation and drug metabolism. Metabolic processes can be quantified in vivo by positron emission tomography scanning (PET). We wished to develop a PET technique to measure hepatic first-pass metabolism of ammonia. Seven anaesthetised pigs were given positron-labelled ammonia, 13 NH 3 , into the portal vein and into the vena cava as successive 2-min infusions followed by 22-min dynamic liver scanning. Vena cava infusion data were used to account for recirculation of tracer and metabolites following the portal vein infusion. The scan data were analysed by a model of sinusoidal zonation of ammonia metabolism with periportal urea formation and perivenous formation of glutamine. The hepatic extraction fraction of 13 NH 3 was 0.73±0.16 (mean±SD, n=7 pigs). Values of clearance of ammonia to urea and to glutamine were obtained, as were rate constants for washout of these two metabolites. Overall, the modelling showed half of the ammonia uptake to be converted to urea and half to glutamine. The washout rate constant for glutamine was about one-tenth of that for urea. We conclude that hepatic first-pass metabolism of ammonia was successfully assessed by PET. (orig.)

Optically stimulated luminescence techniques in retrospective dosimetry using single grains of quartz extracted from unheated materials

Energy Technology Data Exchange (ETDEWEB)

Joerkov Thomsen, Kristina

2004-02-01

This work investigates the possibility of applying optically stimulated luminescence (OSL) in retrospective dose determinations using unheated materials. It focuses on identifying materials suitable for use in assessment of doses absorbed as a consequence of radiation accidents (i.e. accident dosimetry). Special attention has been paid to quartz extracted from unheated building materials such as concrete and mortar. The single-aliquot regeneration-dose (SAR) protocol has been used to determine absorbed doses in small aliquots as well as single grains of quartz. It is shown that OSL measurements of single grains of quartz extracted from poorly-bleached building materials can provide useful information on radiation accident doses, even when the luminescence sensitivity is low. Sources of variance in well-bleached single grain dose distributions have been investigated in detail and it is concluded that the observed variability in the data is consistent with the sum (in quadrature) of a component, which depends on the number of photons detected from each grain, and a fixed component independent of light level. Dose depth profiles through laboratory irradiated concrete bricks have successfully been measured and minimum detection limits of less than 100 mGy are derived. Measurements of thermal transfer in single grains of poorly-bleached quartz show that thermal transfer is variable on a grain-to-grain basis and that it can be a source of variance in single-grain dose distributions. Furthermore, the potential of using common household and workplace chemicals, such as table salt, washing powder and water softener, in retrospective dosimetry has been investigated. It is concluded that such materials should be considered as retrospective dosimeters in the event of a radiation accident. (au)

Device Performance Improvement of Double-Pass Wire Mesh Packed Solar Air Heaters under Recycling Operation Conditions

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Chii-Dong Ho

2016-01-01

Full Text Available The improvement of device performance of a recycling solar air heater featuring a wire mesh packing was investigated experimentally and theoretically. The application of the wire mesh packing and recycle-effect concept to the present study were proposed aiming to strengthen the convective heat-transfer coefficient due to increased turbulence. Comparisons were made among different designs, including the single-pass, flat-plate double-pass and recycling double-pass wire mesh packed operations. The collector efficiency of the recycling double-pass wire mesh packed solar air heater was much higher than that of the other configurations for various recycle ratios and mass flow rates scenarios. The power consumption increment due to implementing wire mesh in solar air heaters was also discussed considering the economic feasibility. A fairly good agreement between theoretical predictions and experimental measurements was achieved with an analyzed error of 1.07%–9.32%.

Cerebral Amyloid Angiopathy

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Mahmut Edip Gürol

2009-03-01

Full Text Available Cerebral amyloid angiopathy (CAA is characterized by the accumulation of amyloid beta-peptides (Ab in the walls of leptomeningeal arteries, arterioles, and veins. Despite the fact that these pathological changes were first described in 1909, major advancement in our understanding of the clinicoradiological manifestations, neurobiology, and course of CAA has occurred only during the last 30 years. No significant associations have been shown between CAA and other systemic/visceral amyloidoses or vascular risk factors, including hypertension. CAA is well known as the most common cause of spontaneous and anticoagulant-related lobar parenchymal ICH in the elderly. It also causes lobar cerebral microbleeds (CMBs, small dot-like dark susceptibility artifacts visible with gradient recalled echo (GRE-magnetic resonance imaging (MRI. CMBs are important markers of disease severity and predictors of CAA progression. Amyloid angiopathy is also a common cause of ischemic microvascular white matter disease (WMD and deep cerebral infarctions. Such WMD is defined as subcortical and periventricular white matter changes without obvious infarction, as well as a dark appearance on computerized tomography (CT and a bright appearance on fluid attenuated inversion recovery (FLAIR-MRI. CAA-related vascular dysfunction, with its hemorrhagic and ischemic complications, is a recognized contributor to vascular cognitive impairment in the elderly, an independent effect that is synergistically increased by Alzheimer pathologies, such as plaques and tangles. A set of clinicoradiological criteria was established for the accurate diagnosis of CAA. According to the Boston Criteria, patients aged 55 years and older with multiple hemorrhages (on CT or GRE-MRI restricted to the lobar, cortical, or corticosubcortical regions (cerebellar hemorrhage allowed are diagnosed as probable CAA when no other etiology is found; a single hemorrhage in the same region is classified as possible

Low-pass sequencing for microbial comparative genomics

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Kennedy Sean

2004-01-01

Full Text Available Abstract Background We studied four extremely halophilic archaea by low-pass shotgun sequencing: (1 the metabolically versatile Haloarcula marismortui; (2 the non-pigmented Natrialba asiatica; (3 the psychrophile Halorubrum lacusprofundi and (4 the Dead Sea isolate Halobaculum gomorrense. Approximately one thousand single pass genomic sequences per genome were obtained. The data were analyzed by comparative genomic analyses using the completed Halobacterium sp. NRC-1 genome as a reference. Low-pass shotgun sequencing is a simple, inexpensive, and rapid approach that can readily be performed on any cultured microbe. Results As expected, the four archaeal halophiles analyzed exhibit both bacterial and eukaryotic characteristics as well as uniquely archaeal traits. All five halophiles exhibit greater than sixty percent GC content and low isoelectric points (pI for their predicted proteins. Multiple insertion sequence (IS elements, often involved in genome rearrangements, were identified in H. lacusprofundi and H. marismortui. The core biological functions that govern cellular and genetic mechanisms of H. sp. NRC-1 appear to be conserved in these four other halophiles. Multiple TATA box binding protein (TBP and transcription factor IIB (TFB homologs were identified from most of the four shotgunned halophiles. The reconstructed molecular tree of all five halophiles shows a large divergence between these species, but with the closest relationship being between H. sp. NRC-1 and H. lacusprofundi. Conclusion Despite the diverse habitats of these species, all five halophiles share (1 high GC content and (2 low protein isoelectric points, which are characteristics associated with environmental exposure to UV radiation and hypersalinity, respectively. Identification of multiple IS elements in the genome of H. lacusprofundi and H. marismortui suggest that genome structure and dynamic genome reorganization might be similar to that previously observed in the

Metal-coated semiconductor nanostructures and simulation of photon extraction and coupling to optical fibers for a solid-state single-photon source

International Nuclear Information System (INIS)

Suemune, Ikuo; Nakajima, Hideaki; Liu, Xiangming; Odashima, Satoru; Asano, Tomoya; Iijima, Hitoshi; Huh, Jae-Hoon; Idutsu, Yasuhiro; Sasakura, Hirotaka; Kumano, Hidekazu

2013-01-01

We have realized metal-coated semiconductor nanostructures for a stable and efficient single-photon source (SPS) and demonstrated improved single-photon extraction efficiency by the selection of metals and nanostructures. We demonstrate with finite-difference time-domain (FDTD) simulations that inclination of a pillar sidewall, which changes the structure to a nanocone, is effective in improving the photon extraction efficiency. We demonstrate how such nanocone structures with inclined sidewalls are fabricated with reactive ion etching. With the optimized design, a photon extraction efficiency to outer airside as high as ∼97% generated from a quantum dot in a nanocone structure is simulated, which is the important step in realizing SPS on-demand operations. We have also examined the direct contact of such a metal-embedded nanocone structure with a single-mode fiber facet as a simple and practical method for preparing fiber-coupled SPS and demonstrated practical coupling efficiencies of ∼16% with FDTD simulation. (paper)

Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

Science.gov (United States)

Saibaba, N.

2008-12-01

Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties.

Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

International Nuclear Information System (INIS)

Saibaba, N.

2008-01-01

Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties

Measurement of oxygen extraction fraction (OEF): An optimized BOLD signal model for use with hypercapnic and hyperoxic calibration.

Science.gov (United States)

Merola, Alberto; Murphy, Kevin; Stone, Alan J; Germuska, Michael A; Griffeth, Valerie E M; Blockley, Nicholas P; Buxton, Richard B; Wise, Richard G

2016-04-01

Several techniques have been proposed to estimate relative changes in cerebral metabolic rate of oxygen consumption (CMRO2) by exploiting combined BOLD fMRI and cerebral blood flow data in conjunction with hypercapnic or hyperoxic respiratory challenges. More recently, methods based on respiratory challenges that include both hypercapnia and hyperoxia have been developed to assess absolute CMRO2, an important parameter for understanding brain energetics. In this paper, we empirically optimize a previously presented "original calibration model" relating BOLD and blood flow signals specifically for the estimation of oxygen extraction fraction (OEF) and absolute CMRO2. To do so, we have created a set of synthetic BOLD signals using a detailed BOLD signal model to reproduce experiments incorporating hypercapnic and hyperoxic respiratory challenges at 3T. A wide range of physiological conditions was simulated by varying input parameter values (baseline cerebral blood volume (CBV0), baseline cerebral blood flow (CBF0), baseline oxygen extraction fraction (OEF0) and hematocrit (Hct)). From the optimization of the calibration model for estimation of OEF and practical considerations of hypercapnic and hyperoxic respiratory challenges, a new "simplified calibration model" is established which reduces the complexity of the original calibration model by substituting the standard parameters α and β with a single parameter θ. The optimal value of θ is determined (θ=0.06) across a range of experimental respiratory challenges. The simplified calibration model gives estimates of OEF0 and absolute CMRO2 closer to the true values used to simulate the experimental data compared to those estimated using the original model incorporating literature values of α and β. Finally, an error propagation analysis demonstrates the susceptibility of the original and simplified calibration models to measurement errors and potential violations in the underlying assumptions of isometabolism

Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

DEFF Research Database (Denmark)

Nielsen, Henning B

2014-01-01

and number of patients included were recorded. There was included 113 articles and evidence suggests that rScO2 is reduced during thoracic surgery involving single lung ventilation, major abdominal surgery, hip surgery, and laparoscopic surgery with the patient placed in anti-Tredelenburg's position....... Shoulder arthroscopy in the beach chair and carotid endarterectomy with clamped internal carotid artery (ICA) also cause pronounced cerebral desaturation. A >20% reduction in rScO2 coincides with indices of regional and global cerebral ischemia during carotid endarterectomy. Following thoracic surgery...

Cerebral malaria: susceptibility weighted MRI

Directory of Open Access Journals (Sweden)

Vinit Baliyan

2015-03-01

Full Text Available Cerebral malaria is one of the fatal complications of Plasmodium falciparum infection. Pathogenesis involves cerebral microangiopathy related to microvascular plugging by infected red blood cells. Conventional imaging with MRI and CT do not reveal anything specific in case of cerebral malaria. Susceptibility weighted imaging, a recent advance in the MRI, is very sensitive to microbleeds related to microangiopathy. Histopathological studies in cerebral malaria have revealed microbleeds in brain parenchyma secondary to microangiopathy. Susceptibility weighted imaging, being exquisitely sensitive to microbleeds may provide additional information and improve the diagnostic accuracy of MRI in cerebral malaria.

Uranium extraction from phosphoric acid

International Nuclear Information System (INIS)

Lounis, A.

1983-05-01

A study has been carried out for the extraction of uranium from phosphoric acid produced in Algeria. First of all, the Algerian phosphoric acid produced in Algeria by SONATRACH has been characterised. This study helped us to synthesize a phosphoric acid that enabled us to pass from laboratory tests to pilot scale tests. We have then examined extraction and stripping parameters: diluent, DZEPHA/TOPO ratio and oxidising agent. The laboratory experiments enabled us to set the optimum condition for the choice of diluent, extractant concentration, ratio of the synergic mixture, oxidant concentration, redox potential. The equilibrium isotherms lead to the determination of the number of theoretical stages for the uranium extraction and stripping of uranium, then the extraction from phosphoric acid has been verified on a pilot scale (using a mixer-settler)

Tunable First-Order Resistorless All-Pass Filter with Low Output Impedance

Directory of Open Access Journals (Sweden)

Parveen Beg

2014-01-01

Full Text Available This paper presents a voltage mode cascadable single active element tunable first-order all-pass filter with a single passive component. The active element used to realise the filter is a new building block termed as differential difference dual-X current conveyor with a buffered output (DD-DXCCII. The filter is thus realized with the help of a DD-DXCCII, a capacitor, and a MOS transistor. By exploiting the low output impedance, a higher order filter is also realized. Nonideal and parasitic study is also carried out on the realised filters. The proposed DD-DXCCII filters are simulated using TSMC the 0.25 µm technology.

Tunable first-order resistorless all-pass filter with low output impedance.

Science.gov (United States)

Beg, Parveen

2014-01-01

This paper presents a voltage mode cascadable single active element tunable first-order all-pass filter with a single passive component. The active element used to realise the filter is a new building block termed as differential difference dual-X current conveyor with a buffered output (DD-DXCCII). The filter is thus realized with the help of a DD-DXCCII, a capacitor, and a MOS transistor. By exploiting the low output impedance, a higher order filter is also realized. Nonideal and parasitic study is also carried out on the realised filters. The proposed DD-DXCCII filters are simulated using TSMC the 0.25 µm technology.

N-isopropyl-4-[123I]iodoamphetamine (123I-IMP) products. A difference in radiochemical purity, unmetabolized fraction, and octanol extraction fraction in arterial blood and regional brain uptake in rats

International Nuclear Information System (INIS)

Kanai, Yasukazu; Hasegawa, Shinji; Kimura, Yasuyuki; Oku, Naohiko; Hatazawa, Jun; Ito, Hiroshi; Fukuda, Hiroshi

2007-01-01

N-isopropyl-4-[ 123 I]iodoamphetamine ( 123 I-IMP) is a lipophilic compound utilized for cerebral blood flow (CBF) measurement with single photon emission computed tomography (SPECT). Two different 123 I-IMP products (IMP A and IMP B ) are commercially available. We examined the radiochemical purity, unmetabolized fraction, and octanol extraction fraction in arterial blood, and the regional brain uptake of IMP A and IMP B in a rat model. IMP B (96.4%±0.08%, P A (95.5%±0.20%). The mean unmetabolized fraction in arterial blood taken at 10 min after intravenous administration of IMP B (69.5%±4.4%, P A (59.6%±2.6%). The mean octanol extraction fraction of IMP B (75.0%±1.3%, P A (67.2%±0.8%). The mean levels of radioactivity in arterial blood sampled at 10 min after injection and mean regional brain radioactivity (cerebral cortices, basal ganglia, brain stem, and cerebellum) at 10-12 min after injection were not significantly different between IMP A and IMP B . The present study indicates differences in the radiochemical purity and the unmetabolized and octanol extraction fraction in arterial blood between the two commercially available 123 I-IMP products. The appropriate octanol extraction fractions for IMP A and IMP B should be determined in humans and employed for quantitative CBF measurement in clinical SPECT. (author)

Cerebral Oximetry in Cardiac Surgery

Directory of Open Access Journals (Sweden)

A. N. Shepelyuk

2012-01-01

Full Text Available Based on the data of numerous current references, the review describes different neuromonitoring methods during cardiac surgery under extracorporeal circulation. It shows that it is important and necessary to make neuromonitoring for the early diagnosis and prevention of neurological complications after cardiac surgery. Particular attention is given to cerebral oximetry; the possibilities and advantages of this technique are described. Correction of cerebral oximetric values is shown to improve survival rates and to reduce the incidence of postoperative complications. Lack of cerebral oximetry monitoring denudes a clinician of important information and possibilities to optimize patient status and to prevent potentially menacing complications, which allows one to conclude that it is necessary to use cerebral oximetry procedures within neu-romonitoring in cardiac surgery. Key words: extracorporeal circulation, cerebral oximetry, neurological dysfunction, cerebral oxygenation.

A simple technique to measure regional cerebral blood flow during intravascular ballon clamping

International Nuclear Information System (INIS)

Furuhata, Shigeru; Kubo, Atsushi; Kawase, Takeshi; Ibata, Yukio; Toya, Shigeo

1988-01-01

A case of giant internal carotid ophthalmic aneurysm was presented. In order to clarify whether the patient could tolerate carotid occlusion, a ballon clamping test was performed before surgery. The cerebral blood flow was measured using early imaging by single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine ( 123 I-IMP). When the ballon clamping test was performed the tracer was injected, and scanning was performed 35 minutes after removing the catheter. This tracer enabled a 'memory of blood flow' during temporary ischemia to determine the character of quick diffusion and slow wash out, that could not be performed by other methods of cerebral blood flow measurement. SPECT with 123 I-IMP can simplify the measurement of cerebral blood flow during the balloon clamping test. (author)

Morphologic changes of cerebral veins in hypertensive rats: venous collagenosis is associated with hypertension.

Science.gov (United States)

Zhou, Min; Mao, Lijuan; Wang, Ying; Wang, Qian; Yang, Zhiyun; Li, Shurong; Li, Ling

2015-03-01

The aims of this study were to determine whether arterial hypertension could affect the venous system of brain and to find out the consequent pathologic changes of cerebral veins. Thirty male Sprague-Dawley rats were divided into 2 groups: a sham-clipped group and a stroke-prone renovascular hypertensive rat group. A 2-kidney 2-clip rat model was used to induce renovascular hypertension in the hypertensive group. Systolic blood pressure was measured by tail cuff once each week. Susceptibility-weighted imaging (SWI) was performed at 12, 16, and 20 weeks after surgery. All the rats were sacrificed after the SWI examination at 20 weeks after surgery. The brains were extracted and embedded in paraffin for histologic examination. Masson trichrome staining was performed to identify venous collagenosis. The sham group demonstrated less prominence of cerebral veins compared with hypertensive groups (P veins on SWI as a sign of venous hypertension and the thickened cerebral venous walls (venous collagenosis), which may play a role in cerebral ischemia and/or infarction, are both consequences of long-term hypertension in hypertensive rats. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Extraction of hydrocarbon products from shales and coals

Energy Technology Data Exchange (ETDEWEB)

Reed, V Z

1918-05-17

A process is disclosed of extracting hydrocarbon oil matter from petroleum-bearing shales and coals which comprises subjecting a mass of such shale or coal, before distillation to the solvent action of material containing an acid, permitting the solvent material to pass through the mass of shale or coal, and recovering the combined solvent and extracted matter.

Leptomeningeal collateral status predicts outcome after middle cerebral artery occlusion.

Science.gov (United States)

Madelung, C F; Ovesen, C; Trampedach, C; Christensen, A; Havsteen, I; Hansen, C K; Christensen, H

2018-01-01

Perfusion through leptomeningeal collateral vessels is a likely pivotal factor in the outcome of stroke patients. We aimed to investigate the effect of collateral status on outcome in a cohort of unselected, consecutive stroke patients with middle cerebral artery occlusion undergoing reperfusion therapy. This retrospectively planned analysis was passed on prospectively collected data from 187 consecutive patients with middle cerebral artery occlusion admitted within 4.5 hours to one center and treated with intravenous thrombolysis alone (N = 126), mechanical thrombectomy alone (N = 5), or both (N = 56) from May 2009 to April 2014. Non-contrast CT (NCCT) and computed tomography angiography (CTA) were provided on admission and NCCT repeated at 24 hours. Collateral status was assessed based on the initial CTA. Hemorrhagic transformation was evaluated on the 24-hour NCCT and according to European Cooperative Acute Stroke Study (ECASS) criteria. Modified Rankin Scale score was assessed at 90 days, and mortality at 1 year. At 90 days, median (IQR) modified Rankin Scale score in patients with poor collateral status was 4 (3-6) compared to 2 (1-4) in patients with good collateral status (P collateral status were less likely to achieve a good 90-day outcome (modified Rankin Scale score 0-2) (Adjusted odds ratio 0.27, 95% CI: 0.09-0.86). During the first year, 40.9% of patients with poor collateral status died vs 18.2% of the remaining population (P = .001). Leptomeningeal collateral status predicts functional outcome, mortality, and hemorrhagic transformation following middle cerebral artery occlusion. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cerebral venous angioma

International Nuclear Information System (INIS)

Inagawa, Tetsuji; Taguchi, Haruyoshi; Kamiya, Kazuko; Yano, Takashi; Nakajima, Reiko

1984-01-01

This report presents a 27-year-old male patient who was diagnosed as having cerebral venous angioma in the postero-temporal area by CT scan and cerebral angiography. The patient improved by removing angioma with electrocoagulation of medullary veins. (Namekawa, K.)

Comparison of first-pass and second-bolus dynamic susceptibility perfusion MRI in brain tumors

International Nuclear Information System (INIS)

Spampinato, M.V.; Besenski, Nada; Rumboldt, Zoran; Wooten, Caroline; Dorlon, Margaret

2006-01-01

Our goal was to evaluate whether the T1 shortening effect caused by contrast leakage into brain tumors, a well-known confounding effect in the quantification of relative cerebral blood volume (rCBV) measurements, may be corrected by the administration of a predose of gadolinium-DTPA. As part of their presurgical imaging protocol, 25 patients with primary brain tumors underwent two consecutive dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MR studies. Intratumoral rCBV measurements and normalized rCBV values obtained during the first-pass and second-bolus studies were compared (Wilcoxon signed-ranks test). The frequency of relatively increased rCBV ratios on the second-bolus study was compared between enhancing and non-enhancing neoplasms (Fisher's exact test). Postprocessing perfusion studies were evaluated for image quality on a scale of 0-3 (Wilcoxon signed-ranks test). Four studies were excluded due to unacceptable image quality. Mean normalized rCBVs were 9.04 (SD 4.64) for the first-pass and 7.99 (SD 3.84) for the second-bolus study. There was no statistically significant difference between the two perfusion studies in either intratumoral rCBV (P=0.237) or rCBV ratio (P=0.181). Five enhancing and four non-enhancing tumors showed a relative increase in rCBV ratio on the second-bolus study, without a significant difference between the groups. Image quality was not significantly different between perfusion studies. Our results did not demonstrate a significant difference between first-pass and second-bolus rCBV measurements in DSC perfusion MR imaging. The administration of a predose of gadolinium-DTPA does not appear to be an efficient way of compensating for the underestimation of intratumoral rCBV values due to the T1 shortening effect. (orig.)

Regional cerebral blood flow assessed by single photon emission computed tomography (SPECT) in dogs with congenital portosystemic shunt and hepatic encephalopathy.

Science.gov (United States)

Or, Matan; Peremans, Kathelijne; Martlé, Valentine; Vandermeulen, Eva; Bosmans, Tim; Devriendt, Nausikaa; de Rooster, Hilde

2017-02-01

Regional cerebral blood flow (rCBF) in eight dogs with congenital portosystemic shunt (PSS) and hepatic encephalopathy (HE) was compared with rCBF in eight healthy control dogs using single photon emission computed tomography (SPECT) with a 99m technetium-hexamethylpropylene amine oxime ( 99m Tc-HMPAO) tracer. SPECT scans were abnormal in all PSS dogs. Compared to the control group, rCBF in PSS dogs was significantly decreased in the temporal lobes and increased in the subcortical (thalamic and striatal) area. Brain perfusion imaging alterations observed in the dogs with PSS and HE are similar to those in human patients with HE. These findings suggest that dogs with HE and PSS have altered perfusion of mainly the subcortical and the temporal regions of the brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Displacement of the central sulcus in cerebral arteriovenous malformations situated in the peri-motor cortex as assessed by magnetoencephalography

International Nuclear Information System (INIS)

Shimamura, Norihito; Ohkuma, Hiroki; Ogane, Kazumi; Manabe, Hiroshi; Yagihashi, Akinori; Kikkawa, Tomoshige; Suzuki, Shigeharu

2003-01-01

In order to determine the optimal treatment for a pen-motor cortex lesion, preoperative orientation of central sulcus (CS) is indispensable. The purpose of this study is to detect a discrepancy between ''functional'' CS and ''anatomical'' CS in cerebral lesions. Stereotactic mapping of functional'' CS was performed on 12 subjects using somatosensory evoked fields (SEFs) with MRI-linked whole head magnetoencephalography (MEG) system preoperatively. All subjects who underwent axial T1-weighted MRI scans had a left-sided lesion with diagnoses including: three arteriovenous malformations (AVM), six gliomas and three meningiomas. Two certified neurosurgeons identified the anatomical CS of the cerebral hemispheres in MRI. Right median nerves were stimulated at the wrists using the following parameters of stimulation: 1 Hz rectangular electrical wave, 0.2 msec duration, and 3 to 5 mA intensity. The sampling rate was 600 Hz and band pass filters were 0.1 to 200 Hz. One hundred epochs were averaged to determine SEFs during a 50 msec pre-stimulus to 300 msec following stimulus onset. Estimations of single dipole were corresponded with N20m of SEFs. Estimated current dipoles were superimposed on the MR images. Anatomical CS accorded with functional CS in the intracranial tumor cases. AVM cases in which the nidus was situated in the peri-motor cortex showed discrepancies between functional CS and anatomical CS marking one gyrus. AVMs situated in the peri-motor area have the ability to displace the CS. Preoperative consideration for AVM treatment should include functional brain mapping to decide the most suitable operative approach and avoid postoperative deficits. (author)

Detection of TRPV4 channel current-like activity in Fawn Hooded hypertensive (FHH rat cerebral arterial muscle cells.

Directory of Open Access Journals (Sweden)

Debebe Gebremedhin

Full Text Available The transient receptor potential vallinoid type 4 (TRPV4 is a calcium entry channel known to modulate vascular function by mediating endothelium-dependent vasodilation. The present study investigated if isolated cerebral arterial myocytes of the Fawn Hooded hypertensive (FHH rat, known to display exaggerated KCa channel current activity and impaired myogenic tone, express TRPV4 channels at the transcript and protein level and exhibit TRPV4-like single-channel cationic current activity. Reverse transcription polymerase chain reaction (RT-PCR, Western blot, and immunostaining analysis detected the expression of mRNA transcript and translated protein of TRPV4 channel in FHH rat cerebral arterial myocytes. Patch clamp recording of single-channel current activity identified the presence of a single-channel cationic current with unitary conductance of ~85 pS and ~96 pS at hyperpolarizing and depolarizing potentials, respectively, that was inhibited by the TRPV4 channel antagonist RN 1734 or HC 067074 and activated by the potent TRPV4 channel agonist GSK1016790A. Application of negative pressure via the interior of the patch pipette increased the NPo of the TRPV4-like single-channel cationic current recorded in cell-attached patches at a patch potential of 60 mV that was inhibited by prior application of the TRPV4 channel antagonist RN 1734 or HC 067047. Treatment with the TRPV4 channel agonist GSK1016790A caused concentration-dependent increase in the NPo of KCa single-channel current recorded in cell-attached patches of cerebral arterial myocytes at a patch potential of 40 mV, which was not influenced by pretreatment with the voltage-gated L-type Ca2+ channel blocker nifedipine or the T-type Ca2+ channel blocker Ni2+. These findings demonstrate that FHH rat cerebral arterial myocytes express mRNA transcript and translated protein for TRPV4 channel and display TRPV4-like single-channel cationic current activity that was stretch-sensitive and

Possibilities of the fish pass restoration

Science.gov (United States)

Čubanová, Lea

2018-03-01

According to the new elaborated methodology of the Ministry of Environment of the Slovak Republic: Identification of the appropriate fish pass types according to water body typology (2015) each barrier on the river must be passable. On the barriers or structures without fish passes new ones should be design and built and on some water structures with existed but nonfunctional fish passes must be realized reconstruction or restoration of such objects. Assessment should be done in terms of the existing migratory fish fauna and hydraulic conditions. Fish fauna requirements resulting from the ichthyological research of the river section with barrier. Hydraulic conditions must than fulfil these requirements inside the fish pass body.

Nanomedicine in cerebral palsy

Science.gov (United States)

Balakrishnan, Bindu; Nance, Elizabeth; Johnston, Michael V; Kannan, Rangaramanujam; Kannan, Sujatha

2013-01-01

Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed. PMID:24204146

Single-molecule studies of oligomer extraction and uptake of dyes in poly(dimethylsiloxane) films.

Science.gov (United States)

Lange, Jeffrey J; Collinson, Maryanne M; Culbertson, Christopher T; Higgins, Daniel A

2009-12-15

Single-molecule microscopic methods were used to probe the uptake, mobility, and entrapment of dye molecules in cured poly(dimethylsiloxane) (PDMS) films as a function of oligomer extraction. The results are relevant to the use of PDMS in microfluidic separations, pervaporation, solid-phase microextraction, and nanofiltration. PDMS films were prepared by spin-casting dilute solutions of Sylgard 184 onto glass coverslips, yielding approximately 1.4 microm thick films after curing. Residual oligomers were subsequently extracted from the films by "spin extraction". In this procedure, 200 microL aliquots of isopropyl alcohol were repeatedly dropped onto the film surface and spun off at 2000 rpm. Samples extracted 5, 10, 20, and 40 times were investigated. Dye molecules were loaded into these films by spin-casting nanomolar dye solutions onto the films. Both neutral perylene diimide (N,N'-bis(butoxypropyl)perylene-3,4,9,10-tetracarboxylic diimide) and cationic rhodamine 6G (R6G) dyes were employed. The films were imaged by confocal fluorescence microscopy. The images obtained depict nonzero populations of fixed and mobile molecules in all films. Cross-correlation methods were used to quantitatively determine the population of fixed molecules in a given region, while a Bayesian burst analysis was used to obtain the total population of molecules. The results show that the total amount of dye loaded increases with increased oligomer extraction, while the relative populations of fixed and mobile molecules decrease and increase, respectively. Bulk R6G data also show greater dye loading with increased oligomer extraction.

In vitro catheter and sorbent-based method for clearance of radiocontrast material during cerebral interventions

International Nuclear Information System (INIS)

Angheloiu, George O.; Hänscheid, Heribert; Reiners, Christoph; Anderson, William D.; Kellum, John A.

2013-01-01

Background: Contrast-induced acute kidney injury is a severe condition resulting from the use of radiology contrast in patients with predisposing factors. Hypothesis: We hypothesized that a novel system including a device containing polymer resin sorbent beads and a custom-made suctioning catheter could efficiently remove contrast from an in vitro novel model of circulatory system (MOCS) mimicking the cerebral circulation. Methods: A custom-made catheter was built and optimized for cerebral venous approach. The efficiency of a system made of a polymer resin sorbent beads column (CST 401, Cytosorbents) and this particular catheter was tested in the MOCS running a solution composed of 0.9% saline and radio-contrast. During two series of 18 cycles of first-pass experiments we assessed the catheter's suctioning efficiency and the system's ability to clear radio-contrast injected into the MOCS's cerebral arterial segment. We also assessed the functioning and reliability of the MOCS. Results: Mean suctioning efficiency of the catheter was 84% ± 24%. The polymer sorbent column contrast removal rate was initially 96% and gradually decreased with subsequent cycles in a linear fashion during an experiment lasting approximately 90 minutes. The MOCS had a reliability of 0.9946×min −1 where 1 × min −1 was the optimum value. Conclusion: A system including a polymer resin sorbent beads column and a custom-made suctioning catheter had an excellent initial efficiency in quickly removing contrast from an artificial MOCS mimicking the cerebral circulation. MOCS is an inexpensive and relatively reliable custom-made system that can be used for training or testing purposes

Antenatal and intrapartum interventions for preventing cerebral palsy: an overview of Cochrane systematic reviews.

Science.gov (United States)

Shepherd, Emily; Salam, Rehana A; Middleton, Philippa; Makrides, Maria; McIntyre, Sarah; Badawi, Nadia; Crowther, Caroline A

2017-08-08

Cerebral palsy is an umbrella term encompassing disorders of movement and posture, attributed to non-progressive disturbances occurring in the developing fetal or infant brain. As there are diverse risk factors and causes, no one strategy will prevent all cerebral palsy. Therefore, there is a need to systematically consider all potentially relevant interventions for their contribution to prevention. To summarise the evidence from Cochrane reviews regarding the effects of antenatal and intrapartum interventions for preventing cerebral palsy. We searched the Cochrane Database of Systematic Reviews on 7 August 2016, for reviews of antenatal or intrapartum interventions reporting on cerebral palsy. Two authors assessed reviews for inclusion, extracted data, assessed review quality, using AMSTAR and ROBIS, and quality of the evidence, using the GRADE approach. We organised reviews by topic, and summarised findings in text and tables. We categorised interventions as effective (high-quality evidence of effectiveness); possibly effective (moderate-quality evidence of effectiveness); ineffective (high-quality evidence of harm or of lack of effectiveness); probably ineffective (moderate-quality evidence of harm or of lack of effectiveness); and no conclusions possible (low- to very low-quality evidence). We included 15 Cochrane reviews. A further 62 reviews pre-specified the outcome cerebral palsy in their methods, but none of the included randomised controlled trials (RCTs) reported this outcome. The included reviews were high quality and at low risk of bias. They included 279 RCTs; data for cerebral palsy were available from 27 (10%) RCTs, involving 32,490 children. They considered interventions for: treating mild to moderate hypertension (two) and pre-eclampsia (two); diagnosing and preventing fetal compromise in labour (one); preventing preterm birth (four); preterm fetal maturation or neuroprotection (five); and managing preterm fetal compromise (one). Quality of

Biofeedback interventions for people with cerebral palsy: a systematic review protocol.

Science.gov (United States)

MacIntosh, Alexander; Vignais, Nicolas; Biddiss, Elaine

2017-01-13

Cerebral palsy is a life-long disability that affects motor control and activities of daily living. Depending on the type of cerebral palsy, some individuals may have trouble performing tasks with one or both of their arms and/or legs. Different strategies exist to help develop motor capacity. Biofeedback therapy is a commonly applied rehabilitation strategy. In biofeedback therapy, information about the motor behavior while completing a task is given back to the individual to help improve their performance. This can provide valuable information that would otherwise be unknown to the individual. Biofeedback may also have a unique method of operation in clinical populations, such as people with cerebral palsy. Therefore, it is important to identify the most effective mechanisms for specific populations. This review aims to evaluate the effects of biofeedback interventions that have been used towards improving motor performance and motor learning in people with cerebral palsy. Using a customized strategy, MEDLINE, CINAHL, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, SCOPUS, SPORTDiscus, and PEDro databases will be searched. Two independent reviewers will screen titles and abstracts, review full texts for inclusion criteria, and extract data from relevant articles using a standardized template. Quality of evidence and risk of bias will be assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. Several studies have investigated biofeedback-based interventions for people with cerebral palsy. However, there is a great variety and limited consensus regarding how to implement biofeedback mechanisms. This systematic review will consolidate the current evidence to direct future study and develop effective biofeedback rehabilitation strategies. PROSPERO ID: CRD42016047612.

Uranium extraction from underground deposits

International Nuclear Information System (INIS)

Wolfe, C.R.

1982-01-01

Uranium is extracted from underground deposits by passing an aqueous oxidizing solution of carbon dioxide over the ore in the presence of calcium ions. Complex uranium carbonate or bicarbonate ions are formed which enter the solution. The solution is forced to the surface and the uranium removed from it

Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

DEFF Research Database (Denmark)

Madsen, P L; Schmidt, J F; Holm, S

1991-01-01

. They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

Cerebral protection devices for use during carotid artery angioplasty with stenting: a health technology assessment.

Science.gov (United States)

Menon, Devidas; Stafinski, Tania

2006-01-01

This study sought to examine the safety, efficacy, and economic implications of the use of cerebral protection devices during carotid artery angioplasty and stenting (CAS) in high-risk patients with severe carotid artery disease (CAD). A comprehensive search for peer- and non-peer-reviewed studies that compared carotid endarterectomy (CEA) or CAS without cerebral protection to CAS with cerebral protection and appeared in the English language literature between January 1990 and January 2005 was completed. Information from studies identified was extracted using a common data abstraction form and then critically appraised against published quality assessment criteria. Of the eight studies found, six provided information on technical or procedural success rates, with values ranging from 95.6 percent to 100 percent. Three of the four studies comparing groups of patients who received CAS with cerebral protection with those who received only CAS reported a non-statistically significantly higher 30-day incidence of death and stroke (major or minor) in the latter group. None of the three studies comparing CAS with cerebral protection to CEA demonstrated a statistically significant difference in the 30-day incidence of death, major stroke, or myocardial infarction between treatment groups. No economic analyses were found. In high-risk patients with severe CAD, the evidence suggests that CAS with cerebral protection may offer a safe and efficacious alternative to CEA, reducing the risk of embolic peri-procedural complications associated with CAS to acceptable levels.

Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

International Nuclear Information System (INIS)

Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo; Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi.

1990-01-01

Tests using 133 Xe inhalation method and single photon emission computed tomography (SPECT) with acetazolamide (Diamox) were performed in 23 patients with chronic cerebral ischemia, before and after extracranial-intracranial bypass surgery or carotid-endarterectomy. All patients complained of TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery. Cerebral blood flow (CBF) was measured with 133 Xe SPECT, and was measured 15 minutes after intravenous administration of 10-12 mg/kg Diamox, which is known as a cerebral vasodilatory agent (Diamox test). Our results revealed that all patients could be divided into four types according to their resting rCBF and Diamox reactivity. The patients who had normal resting rCBF and normal Diamox reactivity (type 1) were considered to have well-developed collateral circulation and normal cerebral perfusion pressure (CPP) in spite of severe occlusive lesions in the carotid system. Moderate vasodilation due to reduced CPP was considered to occur in patients who had normal resting rCBF and decreased Diamox reactivity (type 2). The resting rCBF remained unchanged, but Diamox reactivity improved to normal after surgery in the patients of type 2, which indicated the improvement of CPP and the resolution of the autoregulatory vasodilation. Maximum vasodilation or dysautoregulation was considered to occur due to the inadequate collateral flow and the severely reduced CPP in patients whose findings revealed decrease in the resting rCBF and impaired Diamox reactivity (type 3). Remarkable improvement was seen in both resting rCBF and Diamox reactivity after surgery in the patients of type 3. In the patients who had decreased resting rCBF and normal Diamox reactivity (type 4), the decreased resting rCBF was considered to result from the reduction in metabolic demand because of irreversible ischemic neuronal damage. (J.P.N.)

Noninvasive measurement of blood flow and extraction fraction

Energy Technology Data Exchange (ETDEWEB)

Peters, A.M.; Gunasekera, R.D.; Henderson, B.L.; Brown, J.; Lavender, J.P.; De Souza, M.; Ash, J.M.; Gilday, D.L.

1987-10-01

We describe the theory of a technique for the noninvasive measurement of organ blood flow which is based on the principle of fractionation of cardiac output and is applicable with any recirculating gamma emitting tracer. The technique effectively determines the count rate that would be recorded over the organ if the tracer behaved like radiolabelled microspheres and was completely trapped in the organ's vascular bed on first pass. After correction for organ depth, the estimated first pass activity plateau, expressed as a fraction of the injected dose is equal to the organ's fraction of the cardiac output (CO). By extending the theory, organ extraction fraction of extractable tracers or mean transit time of nonextractable tracers can be measured. The technique was applied to the measurement of renal blood flow in the native and transplanted kidney, splenic blood flow, the extraction fraction of DTPA by the kidney and of sulphur colloid by the spleen.

Noninvasive measurement of blood flow and extraction fraction

International Nuclear Information System (INIS)

Peters, A.M.; Gunasekera, R.D.; Henderson, B.L.; Brown, J.; Lavender, J.P.; De Souza, M.; Ash, J.M.; Gilday, D.L.

1987-01-01

We describe the theory of a technique for the noninvasive measurement of organ blood flow which is based on the principle of fractionation of cardiac output and is applicable with any recirculating gamma emitting tracer. The technique effectively determines the count rate that would be recorded over the organ if the tracer behaved like radiolabelled microspheres and was completely trapped in the organ's vascular bed on first pass. After correction for organ depth, the estimated first pass activity plateau, expressed as a fraction of the injected dose is equal to the organ's fraction of the cardiac output (CO). By extending the theory, organ extraction fraction of extractable tracers or mean transit time of nonextractable tracers can be measured. The technique was applied to the measurement of renal blood flow in the native and transplanted kidney, splenic blood flow, the extraction fraction of DTPA by the kidney and of sulphur colloid by the spleen. (author)

WebPASS ICASS (HR Personnel Management)

Data.gov (United States)

US Agency for International Development — WebPASS Joint Administrative Support Platforms Post Administrative Software Suite - U.S. Department of State Executive Officers application suite. Web.PASS is the...

Evaluation of ocular acupuncture on cerebral infarction with cerebral blood flow perfusion imaging

International Nuclear Information System (INIS)

Li Yuge; Gao Qinyi; Wang Shuang; Zhao Yong

2008-01-01

To evaluate the immediate effect of ocular acupuncture on patients, an method of SPECT image of cerebral blood flow daily stress test was established. 10 patients diagnosed as cerebral infarction by CT or MRI were tested. They all received 99 Tc m -ECD SPECT imaging at twice before and after ocular acupuncture. By means of image subtraction technique and semi-quantitative method of regional interesting area, the change of regional cerebral blood flow was observed between the two images. Under restful state perfusion of cerebral blood flow in 18 foci was low at the frontal lobe, the cerebellum, the basal ganglia and temporal lobe. After ocular acupuncture, the perfusions were obviously increased in 16 foci among them and the reactivity of the frontal lobe and the cerebellum to ocular acupuncture was higher, the average improvement rate of which was 55.15% and 53.06% respectively, lower in the basal ganglia and temporal lobe, the average improvement rate was 31.79% and 36.67% respectively. 99 Tc m -ECD SPECT cerebral perfusion image has some significant clinic value for evaluating the effect of ocular acupuncture to treating cerebral infarction. (authors)

Botulinum toxin effect on salivary flow rate in children with cerebral palsy.

NARCIS (Netherlands)

Jongerius, P.H.; Rotteveel, J.J.; Limbeek, J. van; Gabreëls, F.J.M.; Hulst, K. van; Hoogen, F.J.A. van den

2004-01-01

OBJECTIVE: To investigate the effectiveness of botulinum neurotoxin (BoNT) type A in reducing salivary flow rate in children with cerebral palsy (CP) with severe drooling. METHODS: During a controlled clinical trial, single-dose BoNT injections into the submandibular salivary glands were compared

Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis

International Nuclear Information System (INIS)

Kawatoko, Toshiharu; Murai, Koichiro; Ibayashi, Setsurou; Tsuji, Hiroshi; Nomiyama, Kensuke; Sadoshima, Seizo; Eujishima, Masatoshi; Kuwabara, Yasuo; Ichiya, Yuichi

1992-01-01

Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO 2 ), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO 2 was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author)

Mapping synaptic pathology within cerebral cortical circuits in subjects with schizophrenia

Directory of Open Access Journals (Sweden)

Robert Sweet

2010-06-01

Full Text Available Converging lines of evidence indicate that schizophrenia is characterized by impairments of synaptic machinery within cerebral cortical circuits. Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g. dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin, or to quantification of proteins using methods unable to resolve relevant cellular compartments. Multiple label fluorescence confocal microscopy represents a means to circumvent many of these limitations, by concurrently extracting information regarding the number, morphology, and relative protein content of synaptic structures. An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions. In this review article we consider the application of multiple label fluorescence confocal microscopy to the mapping of synaptic alterations in subjects with schizophrenia and describe the application of a novel, readily automated, iterative intensity/morphological segmentation algorithm for the extraction of information regarding synaptic structure number, size, and relative protein level from tissue sections obtained using unbiased stereological principles of sampling. In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

Some new developments in actinide solvent extraction systems

International Nuclear Information System (INIS)

Navratil, J.D.

1988-01-01

Consideration is given to application of neutral and acid organophosphoric compounds, adsorbed on various natural and synthetic carriers, in extraction chromatography for separation and isolation of actinides. It is shown that trioctylphosphine oxide (TOPO) on a solid combustible carrier represents the promising material for plutonium extraction. It was established experimentally that polyurethane foam possessed the maximal capacity with respect to TOPO; extractant losses at that after passing of 50 column volumes of nitric acid don't exceed 2 %

Cerebral blood flow patterns using single photon emission computed tomography in patients with dissociative disorders and healthy controls

International Nuclear Information System (INIS)

Shah, M.

2010-01-01

To compare the cerebral blood flow (CBF) changes in patients diagnosed to have Dissociative Disorder with healthy controls. This cross sectional comparative study was done at Dept of Psychiatry Military Hospital Rawalpindi in collaboration with nuclear Medical Centre (NMC), at Armed Forces Institute of Pathology (AFIP) which is a tertiary referral center. A sample of 30 patients diagnosed as having Dissociative Disorder was compared with 10 controls for brain perfusion changes using TC-99m HMPAO (Hexamethyl-propylene-amine-oxime) Tc-99m. In group 1 perfusion changes were observed in 27 (90%) cases whereas unremarkable and insignificant changes were noted in 3 (10%) cases but no perfusion were noted in controls (P<0.001) In patients who were suffering from different types of dissociative disorder marked cerebral hypo perfusion was observed in frontal, frontomotor, orbitofrontal and temporal regions whereas hyperperfusion was noted in frontal and orbitofrontal areas in few cases. Conclusion: Cerebral blood flow changes in the fronto parietal brain are associated with symptomotology in dissociative disorders. (author)

Message passing for quantified Boolean formulas

International Nuclear Information System (INIS)

Zhang, Pan; Ramezanpour, Abolfazl; Zecchina, Riccardo; Zdeborová, Lenka

2012-01-01

We introduce two types of message passing algorithms for quantified Boolean formulas (QBF). The first type is a message passing based heuristics that can prove unsatisfiability of the QBF by assigning the universal variables in such a way that the remaining formula is unsatisfiable. In the second type, we use message passing to guide branching heuristics of a Davis–Putnam–Logemann–Loveland (DPLL) complete solver. Numerical experiments show that on random QBFs our branching heuristics give robust exponential efficiency gain with respect to state-of-the-art solvers. We also manage to solve some previously unsolved benchmarks from the QBFLIB library. Apart from this, our study sheds light on using message passing in small systems and as subroutines in complete solvers

Study of cerebral vascular diseases with radioisotopes in cerebral atherosclerotical subjects and/for subjects with sequelae of cerebral stroke, before and after use of the association piracetam-dihydroergotoxine

International Nuclear Information System (INIS)

Lara, P.F.; Ferreira, A.; Paulillo, L.F.; Cukierman, M.

1985-01-01

Twently subjects with cerebral sclerosis and/or sequelas of cerebral stroke were studied, before and after use of piracetam-dihydroergotoxine. We performed the complete hemispheric cerebral blood flow and cerebral scintigraphy, beyond clinical and neurological examination. Scintigraphies were unchanged. Cerebral circulation times, or both hemispheres, diminished. This occurred, probably, in relation with metabolic effects of both pharmaceutical drugs. The alpha sympatolytic and modulatory effects of dihydroergotoxine should be considered. (author) [pt

Oil price pass-through into inflation

International Nuclear Information System (INIS)

Chen, Shiu-Sheng

2009-01-01

This paper uses data from 19 industrialized countries to investigate oil price pass-through into inflation across countries and over time. A time-varying pass-through coefficient is estimated and the determinants of the recent declining effects of oil shocks on inflation are investigated. The appreciation of the domestic currency, a more active monetary policy in response to inflation, and a higher degree of trade openness are found to explain the decline in oil price pass-through. (author)

Peripherally applied synthetic peptide isoAsp7-Aβ(1-42) triggers cerebral β-amyloidosis.

Science.gov (United States)

Kozin, S A; Cheglakov, I B; Ovsepyan, A A; Telegin, G B; Tsvetkov, P O; Lisitsa, A V; Makarov, A A

2013-10-01

Intracerebral and intraperitoneal inoculation with β-amyloid-rich brain extracts originating from patients with Alzheimer's disease as well as intracerebral injection of aggregates composed of synthetic Aβ can induce cerebral β-amyloidosis, and associated cognitive dysfunctions in susceptible animal hosts. We have found that repetitive intravenous administration of 100 μg of synthetic peptide corresponding to isoAsp7-containing Aβ(1-42), an abundant age-dependent Aβ isoform present both in the pathological brain and in synthetic Aβ preparations, robustly accelerates formation of classic dense-core congophilic amyloid plaques in the brain of β-amyloid precursor protein transgenic mice. Our findings indicate this peptide as an inductive agent of cerebral β-amyloidosis in vivo.

Influences of crystallographic orientations on deformation mechanism and grain refinement of Al single crystals subjected to one-pass equal-channel angular pressing

International Nuclear Information System (INIS)

Han, W.Z.; Zhang, Z.F.; Wu, S.D.; Li, S.X.

2007-01-01

The influences of crystallographic orientations on the evolution of dislocation structures and the refinement process of sub-grains in Al single crystals processed by one-pass equal-channel angular pressing (ECAP) were systematically investigated by means of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. Three single crystals with different orientations, denoted as crystal I, crystal II and crystal III, were specially designed according to the shape of the ECAP die. For crystal I, its insert direction is parallel to [1 1 0] and its extrusion direction is parallel to [1-bar11]. For crystal II, the (1-bar11) plane is located parallel to the intersection plane of the ECAP die, and the [1 1 0] direction is along the general shear direction on the intersection plane. For crystal III, the (1-bar11) plane is laid on the plane perpendicular to the intersection of the ECAP die, and the [1 1 0] direction is vertical to the general shear direction. For crystal I, abundant cell block structures with multi-slip characters were formed, and they should be induced by four symmetric slip systems, while for crystal II, there are two sets of sub-grain structures with higher misorientation, making an angle of ∼70 deg., which can be attributed to the interactions of the two asymmetric primary slip planes, whereas for crystal III, only one set of ribbon structures was parallel to the traces of (1-bar11) with the lowest misorientation angle among the three single crystals, which should result from the homogeneous slip on the primary slip plane. The different microstructural features of the three single crystals provide clear experimental evidence that the microstructures and misorientation evolution are strongly affected by the crystallographic orientation or by the interaction between shear deformation imposed by the ECAP die and the intrinsic slip deformation of the single crystals. Based on the experimental results and the

Saturation measurement accuracy in clinical near-infrared cerebral oximeters with a 3D-printed channel array phantom

Science.gov (United States)

Afshari, Ali; Ghassemi, Pejhman; Halprin, Molly; Lin, Jonathan; Weininger, Sandy; Gandjbakhche, Amir H.; Wang, Jianting; Pfefer, Joshua

2018-02-01

Clinical cerebral oximeters based on near-infrared spectroscopy (NIRS) are a commonly used, non-invasive tool for intraoperative monitoring of hemoglobin saturation. Research to verify performance of cerebral oximeters in human subject trials has shown differences between commercially available devices. Test methods based on tissue-simulating phantoms have been proposed to augment clinical findings. While prior studies have focused on liquid phantoms, this work is aimed at developing methods based on solid polymer phantoms that are stable. Specifically, we have designed and fabricated a neonatal/pediatric head mimicking layered phantoms based on a 3D-printed cerebral matrix incorporating an array of vessel-simulating linear channels. Superficial layers incorporating homogeneous molded polydimethylsiloxane (PDMS) slabs were fabricated to represent CSF, scalp and skull regions. The cerebral matrix was filled with bovine blood desaturated with sodium dithionite to achieve oxygenation levels across the 40-90% range. Measurements were performed with a commercially available cerebral oximeter using two probes with different illumination-collection geometries, as designed for neonatal and pediatric patients. Reference measurements of samples were performed with a CO-oximeter before injection and after extraction. Results from applied cerebral oximeters indicate a strong sensitivity to the thickness of the superficial layer of the phantom. Better correlation with the reference CO-oximeter results were obtained in the superficial layer thickness of 0.8-2.5 mm range. Channel array phantoms with modular superficial layers represent a promising approach for performance testing of NIRS-based cerebral oximeters.

Optically stimulated luminescence techniques in retrospective dosimetry using single grains of quartz extracted from unheated materials

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov

dosimetry). Special attention has been paid to quartz extracted from unheated building materials such as concrete and mortar. The single-aliquot regeneration-dose (SAR) protocol has been used to determine absorbeddoses in small aliquots as well as single grains of quartz. It is shown that OSL measurements...... that the observed variability in the data is consistent with the sum (in quadrature) of a component,which depends on the number of photons detected from each grain, and a fixed component independent of light level. Dose depth profiles through laboratory irradiated concrete bricks have successfully been measured...

Optimization of band-pass filtering parameters of a Raman lidar detecting atmospheric water vapor

International Nuclear Information System (INIS)

Cao, Kai-Fa; Hu, Shun-Xing; Wang, Ying-jian

2012-01-01

It is very important for daytime Raman lidar measurement of water vapor to determine the parameters of a band-pass filter, which are pertinent to the lidar signal to noise ratio (SNR). The simulated annealing (SA) algorithm method has an advantage in finding the extremum of a certain cost function. In this paper, the Raman spectrum of water vapor is simulated and then a first realization of a simulated annealing algorithm in the optimization of a band-pass filter of a Raman lidar system designed to detect daytime water vapor is presented. The simulated results indicate that the narrow band-pass filter has higher SNR than the wide filter does but there would be an increase in the temperature sensitivity of a narrowband Raman water vapor lidar in the upper troposphere. The numerical simulation indicates that the magnitude of the temperature dependent effect can reach 3.5% or more for narrow band-pass Raman water vapor measurements so it is necessary to consider a new water vapor Raman lidar equation that permits the temperature sensitivity of these equations to be confined to a single term. (paper)

A study of the acute effect of smoking on cerebral blood flow using 99mTc-ECD SPET

International Nuclear Information System (INIS)

Yamamoto, Yuka; Nishiyama, Yoshihiro; Monden, Toshihide; Satoh, Katashi; Ohkawa, Motoomi

2003-01-01

Cigarette smoking is known to be associated with atherosclerosis, is an important risk factor for stroke and has other serious effects. The aim of this study was to evaluate the acute effect of cigarette smoking on cerebral blood flow using statistical parametric mapping (SPM). Ten healthy volunteers with a smoking habit were studied using technetium-99m-labelled ethylcysteinate dimer single-photon emission tomography (SPET). We evaluated the regional cerebral blood flow under the smoking and resting states. The regional cerebral blood flow on smoking-activated SPET was significantly decreased in the whole brain as compared with that on resting SPET. Our findings therefore suggest that one of the acute effects of cigarette smoking is to induce a diffuse decrease in cerebral blood flow. (orig.)

Single patient doses of {sup 99m}Tc-HDP: Assessment of radiochemical purity, sterility and extractables from a polypropylene syringe over six hours

Energy Technology Data Exchange (ETDEWEB)

Parkes, S.L.; Varelis, P. [St George Hospital, Kogarah, NSW (Australia). Department of Nuclear Medicine

1997-12-01

Full text: The purpose of this investigation was to determine the radiochemical purity (RCP), sterility and extractables for {sup 99m}Tc oxidronate ({sup 99m}Tc-HDP) stored in polypropylene syringes over < six-hour period. The radiochemical purity was determined using a two-strip ITLC procedure, performed at time 0, 1, 2, 4, 6 hours. The sterility and endotoxin levels were tested by a NATA accredited laboratory, after allowing the radiopharmaceutical to stand at room temperature for six hours in the syringes. Plasticisers and other likely compounds that could be extracted from the syringes into the aqueous solution were determined by high pressure liquid chromatography (HPLC) diode array detection. This analysis involved shaking normal saline in a syringe over night and then injecting an aliquot of this solution onto a C18 analytical column and monitoring the effluent at 200 and 253 nm. The radiochemical purity of {sup 99m}Tc-HDP did not significantly change over the course of the study and remained above the recommended RCP for this radiopharmaceutical. Furthermore, at six hours the RCP of {sup 99m}Tc-HDP stored in both the manufacturer`s vial and a syringe were identical. Sterility testing of {sup 99m}Tc-HDP stored in syringes showed no microbial growth and less than 10 endotoxin units/mL (pass). The HPLC analysis did not show the presence of any extraneous compounds in the aqueous solution. Single patient doses of {sup 99m}Tc-HDP stored in polypropylene syringes over a six-hour period fulfill all the quality control requirements for administration to humans.

Extracting physics of life at the molecular level: A review of single-molecule data analyses.

Science.gov (United States)

Colomb, Warren; Sarkar, Susanta K

2015-06-01

Studying individual biomolecules at the single-molecule level has proved very insightful recently. Single-molecule experiments allow us to probe both the equilibrium and nonequilibrium properties as well as make quantitative connections with ensemble experiments and equilibrium thermodynamics. However, it is important to be careful about the analysis of single-molecule data because of the noise present and the lack of theoretical framework for processes far away from equilibrium. Biomolecular motion, whether it is free in solution, on a substrate, or under force, involves thermal fluctuations in varying degrees, which makes the motion noisy. In addition, the noise from the experimental setup makes it even more complex. The details of biologically relevant interactions, conformational dynamics, and activities are hidden in the noisy single-molecule data. As such, extracting biological insights from noisy data is still an active area of research. In this review, we will focus on analyzing both fluorescence-based and force-based single-molecule experiments and gaining biological insights at the single-molecule level. Inherently nonequilibrium nature of biological processes will be highlighted. Simulated trajectories of biomolecular diffusion will be used to compare and validate various analysis techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of anthelmintic activity and in silico PASS assisted prediction of Cordia dichotoma (Forst.) root extract.

Science.gov (United States)

Jamkhande, Prasad G; Barde, Sonal R

2014-01-01

Worm infection and associated complications are severe problems that afflict a large population worldwide. Failure of synthetic drugs in worm infections because of drug resistance has made alternative drug therapy desirable. Cordia dichotoma (Forst.) is an ethnomedicinal plant which is rich in several secondary metabolites. Traditionally, the plant has been claimed to have high medicinal properties including antimicrobial activity and cytotoxicity. The study begun with an aim to explore plant-based natural anthelmintic agents against Pheretima posthuma, an Indian earthworm. Methanol extract of the drug was obtained by successive soxhlet extraction. The extract was tested for different phytochemicals. Worms were exposed to 10 mg/ml, 25 mg/ml, 50 mg/ml, and 75 mg/ml concentrations of extract and standard drug, albendazole. A software-based tool, prediction of activity spectra for substances was used to estimate anthelmintic efficacy of plant metabolites. The phytochemical analysis revealed presence of alkaloids, tannins, glycosides, saponins, flavonoids, and phenols. The extract showed dose-dependent effects, affecting worm motility, viability, and mortality. It was also found that the biological activity spectrum of the plant phytoconstituents such as octacosanol, lupeol, caffeic acid, and hentricontanol were >0.5 (probable activity > 0.5). The findings of the present work suggest that the extract of C. dichotoma significantly interferes with motility pattern of P. posthuma. The paralysis and mortality of P. posthuma might be due to the combined effects different phytoconstituents. The extract of C. dichotoma promises natural sources to control worm infection.

Regional cerebral blood flow in SPECT pattern in Parkinson's disease

International Nuclear Information System (INIS)

Lenart-Jankowska, D.; Junik, R.; Sowinski, J.; Gembicki, M.; Wender, M.

1997-01-01

The purpose of our work was to compare the regional cerebral blood flow (rCBF) in SPECT examination in Parkinson's disease with (17 cases) and without (7 cases) dementia and in various clinical stages of the disease. The patients underwent SPECT examination 5-40 min after intravenous application of HMPAO (Ceretec, Amersham) with 740 Mbq (20 mCi) pertechnate 99m Tc. SPECT was performed with a Siemens Diacam single-head rotating gamma camera coupled to a high resolution collimator and Icon computer system provided by the manufacturer. The results were defined in relative values of ROI in relation to cerebellum. Patients with Parkinson's disease showed hypoperfusion in cerebral lobes and in deep cerebral structures including the basal ganglia. Regional perfusion deficit in SPECT was seen with and without associated dementia and already in early stage of the disease. Parkinson's disease is provoked by the lesions of dopaminergic neurons of the central nervous system leading to domination of extrapyramidal symptoms. There are many indications that also the neurotransmitters associated with cognitive functions as acetylcholine demonstrate some abnormalities. However, only in some cases of Parkinson's disease dementia is the dominating symptom. Our results of regional cerebral blood flow testify that in Parkinson's disease the dysfunction of the central nervous system is more diffuse than has previously been suggested. (author)

Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

Science.gov (United States)

Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

2012-08-01

To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

Cerebral blood flow in acute and chronic ischemic stroke using xenon-133 inhalation tomography

DEFF Research Database (Denmark)

Vorstrup, S; Paulson, O B; Lassen, N A

1986-01-01

. They showed in the acute phase (Days 1-3) very large low-flow areas, larger than the hypodense areas seen on the CT scan. The cerebral vasoconstrictor and vasodilator capacity was tested in the acute phase following aminophylline and acetazolamide, respectively. A preserved but reduced reactivity was seen......Serial measurements of cerebral blood flow (CBF) were performed in 12 patients with acute symptoms of ischemic cerebrovascular disease. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. Six patients had severe strokes and large infarcts on the CT scan...

Cerebral CBM1 neuron contributes to synaptic modulation appearing during rejection of seaweed in Aplysia kurodai.

Science.gov (United States)

Narusuye, Kenji; Nagahama, Tatsumi

2002-11-01

The Japanese species Aplysia kurodai feeds well on Ulva but rejects Gelidium with distinctive rhythmic patterned movements of the jaws and radula. We have previously shown that the patterned jaw movements during the rejection of Gelidium might be caused by long-lasting suppression of the monosynaptic transmission from the multiaction MA neurons to the jaw-closing (JC) motor neurons in the buccal ganglia and that the modulation might be directly produced by some cerebral neurons. In the present paper, we have identified a pair of catecholaminergic neurons (CBM1) in bilateral cerebral M clusters. The CBM1, probably equivalent to CBI-1 in A. californica, simultaneously produced monosynaptic excitatory postsynaptic potentials (EPSPs) in the MA and JC neurons. Firing of the CBM1 reduced the size of the inhibitory postsynaptic currents (IPSCs) in the JC neuron, evoked by the MA spikes, for >100 s. Moreover, the application of dopamine mimicked the CBM1 modulatory effects and pretreatment with a D1 antagonist, SCH23390, blocked the modulatory effects induced by dopamine. It could also largely block the modulatory effects induced by the CBM1 firing. These results suggest that the CBM1 may directly modulate the synaptic transmission by releasing dopamine. Moreover, we explored the CBM1 spike activity induced by taste stimulation of the animal lips with seaweed extracts by the use of calcium imaging. The calcium-sensitive dye, Calcium Green-1, was iontophoretically loaded into a cell body of the CBM1 using a microelectrode. Application of either Ulva or Gelidium extract to the lips increased the fluorescence intensity, but the Gelidium extract always induced a larger change in fluorescence compared with the Ulva extract, although the solution used induced the maximum spike responses of the CBM1 for each of the seaweed extracts. When the firing frequency of the CBM1 activity after taste stimulation was estimated, the Gelidium extract induced a spike activity of ~30 spikes

Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

Directory of Open Access Journals (Sweden)

Henning Bay Nielsen

2014-03-01

Full Text Available Near-infrared spectroscopy (NIRS is used to monitor regional cerebral oxygenation (rScO2 during cardiac surgery but is less established during non-cardiac surgery. This systematic review aimed i to determine the non-cardiac surgical procedures that provoke a reduction in rScO2 and ii to evaluate whether an intraoperative reduction in rScO2 influences postoperative outcome. The PubMed and Embase database were searched from inception until April 30, 2013 and inclusion criteria were intraoperative NIRS determined rScO2 in adult patients undergoing non-cardiac surgery. The type of surgery and number of patients included were recorded. There was included 113 articles and evidence suggests that rScO2 is reduced during thoracic surgery involving single lung ventilation, major abdominal surgery, hip surgery, and laparascopic surgery with the patient placed in anti-Tredelenburg’s position. Shoulder arthroscopy in the beach chair and carotid endarterectomy with clamped internal carotid artery also cause pronounced cerebral desaturation. A >20% reduction in rScO2 coincides with indices of regional and global cerebral ischemia during carotid endarterectomy. Following thoracic surgery, major orthopedic and abdominal surgery the occurrence of postoperative cognitive dysfunction might be related to intraoperative cerebral desaturation. In conclusion, certain non-cardiac surgical procedures is associated with an increased risk for the occurrence of regional cerebral oxygenation. Evidence for an association between cerebral desaturation and postoperative outcome parameters other than cognitive dysfunction needs to be established.

Photothrombosis-induced infarction of the mouse cerebral cortex is not affected by the Nrf2-activator sulforaphane.

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Michelle J Porritt

Full Text Available Sulforaphane-induced activation of the transcription factor NF-E2 related factor 2 (Nrf2 or the gene Nfe2l2 and subsequent induction of the phase II antioxidant system has previously been shown to exert neuroprotective action in a transient model of focal cerebral ischemia. However, its ability to attenuate functional and cellular deficits after permanent focal cerebral ischemia is not clear. We assessed the neuroprotective effects of sulforaphane in the photothrombotic model of permanent focal cerebral ischemia. Sulforaphane was administered (5 or 50 mg/kg, i.p. after ischemic onset either as a single dose or as daily doses for 3 days. Sulforaphane increased transcription of Nrf2, Hmox1, GCLC and GSTA4 mRNA in the brain confirming activation of the Nrf2 system. Single or repeated administration of sulforaphane had no effect on the infarct volume, nor did it reduce the number of activated glial cells or proliferating cells when analyzed 24 and 72 h after stroke. Motor-function as assessed by beam-walking, cylinder-test, and adhesive test, did not improve after sulforaphane treatment. The results show that sulforaphane treatment initiated after photothrombosis-induced permanent cerebral ischemia does not interfere with key cellular mechanisms underlying tissue damage.

Photothrombosis-induced infarction of the mouse cerebral cortex is not affected by the Nrf2-activator sulforaphane.

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Porritt, Michelle J; Andersson, Helene C; Hou, Linda; Nilsson, Åsa; Pekna, Marcela; Pekny, Milos; Nilsson, Michael

2012-01-01

Sulforaphane-induced activation of the transcription factor NF-E2 related factor 2 (Nrf2 or the gene Nfe2l2) and subsequent induction of the phase II antioxidant system has previously been shown to exert neuroprotective action in a transient model of focal cerebral ischemia. However, its ability to attenuate functional and cellular deficits after permanent focal cerebral ischemia is not clear. We assessed the neuroprotective effects of sulforaphane in the photothrombotic model of permanent focal cerebral ischemia. Sulforaphane was administered (5 or 50 mg/kg, i.p.) after ischemic onset either as a single dose or as daily doses for 3 days. Sulforaphane increased transcription of Nrf2, Hmox1, GCLC and GSTA4 mRNA in the brain confirming activation of the Nrf2 system. Single or repeated administration of sulforaphane had no effect on the infarct volume, nor did it reduce the number of activated glial cells or proliferating cells when analyzed 24 and 72 h after stroke. Motor-function as assessed by beam-walking, cylinder-test, and adhesive test, did not improve after sulforaphane treatment. The results show that sulforaphane treatment initiated after photothrombosis-induced permanent cerebral ischemia does not interfere with key cellular mechanisms underlying tissue damage.

Neighbourhood-consensus message passing and its potentials in image processing applications

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Ružic, Tijana; Pižurica, Aleksandra; Philips, Wilfried

2011-03-01

In this paper, a novel algorithm for inference in Markov Random Fields (MRFs) is presented. Its goal is to find approximate maximum a posteriori estimates in a simple manner by combining neighbourhood influence of iterated conditional modes (ICM) and message passing of loopy belief propagation (LBP). We call the proposed method neighbourhood-consensus message passing because a single joint message is sent from the specified neighbourhood to the central node. The message, as a function of beliefs, represents the agreement of all nodes within the neighbourhood regarding the labels of the central node. This way we are able to overcome the disadvantages of reference algorithms, ICM and LBP. On one hand, more information is propagated in comparison with ICM, while on the other hand, the huge amount of pairwise interactions is avoided in comparison with LBP by working with neighbourhoods. The idea is related to the previously developed iterated conditional expectations algorithm. Here we revisit it and redefine it in a message passing framework in a more general form. The results on three different benchmarks demonstrate that the proposed technique can perform well both for binary and multi-label MRFs without any limitations on the model definition. Furthermore, it manifests improved performance over related techniques either in terms of quality and/or speed.

Quantification of extra-cerebral and cerebral hemoglobin concentrations during physical exercise using time-domain near infrared spectroscopy.

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Auger, Héloïse; Bherer, Louis; Boucher, Étienne; Hoge, Richard; Lesage, Frédéric; Dehaes, Mathieu

2016-10-01

Fitness is known to have beneficial effects on brain anatomy and function. However, the understanding of mechanisms underlying immediate and long-term neurophysiological changes due to exercise is currently incomplete due to the lack of tools to investigate brain function during physical activity. In this study, we used time-domain near infrared spectroscopy (TD-NIRS) to quantify and discriminate extra-cerebral and cerebral hemoglobin concentrations and oxygen saturation ( SO 2 ) in young adults at rest and during incremental intensity exercise. In extra-cerebral tissue, an increase in deoxy-hemoglobin ( HbR ) and a decrease in SO 2 were observed while only cerebral HbR increased at high intensity exercise. Results in extra-cerebral tissue are consistent with thermoregulatory mechanisms to dissipate excess heat through skin blood flow, while cerebral changes are in agreement with cerebral blood flow ( CBF ) redistribution mechanisms to meet oxygen demand in activated regions during exercise. No significant difference was observed in oxy- ( HbO 2 ) and total hemoglobin ( HbT ). In addition HbO 2 , HbR and HbT increased with subject's peak power output (equivalent to the maximum oxygen volume consumption; VO 2 peak) supporting previous observations of increased total mass of red blood cells in trained individuals. Our results also revealed known gender differences with higher hemoglobin in men. Our approach in quantifying both extra-cerebral and cerebral absolute hemoglobin during exercise may help to better interpret past and future continuous-wave NIRS studies that are prone to extra-cerebral contamination and allow a better understanding of acute cerebral changes due to physical exercise.

Sodium transport through the cerebral sodium-glucose transporter exacerbates neuron damage during cerebral ischaemia.

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Yamazaki, Yui; Harada, Shinichi; Wada, Tetsuyuki; Yoshida, Shigeru; Tokuyama, Shogo

2016-07-01