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991.
锂/聚苯电池的放电特性取决于其放电电流密度(id)。当id很小时,高分子电极在整个厚度范围内均匀放电。当id很高时,正极的反应被限制在一狭小区域,该区域随着电池的不断放电而向高分子电极内部穿透,并且电阻不断增加,而截止电压表明放电过程的结束。当以中等电流放电时,上述两种放电形式都存在。据此,建立了锂/导电高分子电池的放电电压与放电电流的关系式。 相似文献
992.
Clinicopathological features of hepatocellular carcinoma evaluated by vascular endothelial growth factor expression 总被引:1,自引:0,他引:1
Amaoka N Osada S Kanematsu M Imai H Tomita H Tokuyama Y Sakashita F Nonaka K Goshima S Kondo H Adachi Y 《Journal of gastroenterology and hepatology》2007,22(12):2202-2207
AIM: To evaluate the significance of the expression of vascular endothelial growth factor (VEGF), its correlation with clinicopathological variables were studied in the tissue of hepatocellular carcinoma (HCC) and surrounding liver. METHODS: In 56 samples (tumor and non-tumor liver tissue) collected from 28 patients, VEGF expression was examined by immunohistochemistry and western blot analysis. RESULTS: The value of VEGF expression by western blotting was correlated with immunohistochemical staining grade. In tumor tissue, the value of VEGF expression correlated with tumor size (P = 0.034), á-fetoprotein (P = 0.036) and protein induced by vitamin K absence-II by simple regression, and histological grade (P = 0.0132) by the unpaired t-test. The level of VEGF expression in non-tumor liver was found to correlate with the value of serum albumin (P = 0.008), cholinesterase (P = 0.012) and prothrombin activity (P = 0.046). The frequency of simple nodular type in gross appearance decreased in cases with high tumor/non-tumor (T/N) ratio (P = 0.022), and the degree of portal vein invasion progressed with an increase in the T/N ratio (P = 0.008). The T/N ratio was significantly higher in early recurrence cases (P = 0.0081). CONCLUSION: This study on the expression of VEGF might be useful to estimate the liver condition and the clinicopathological features of HCC. 相似文献
993.
Frontotemporal lobar degeneration (FTLD) encompasses a heterogeneous group of clinical syndromes that include frontotemporal dementia (FTD), frontotemporal dementia with motor neurone disease (FTD/MND), progressive non-fluent aphasia (PNFA), semantic dementia (SD) and progressive apraxia (PAX). Clinical phenotype is often assumed to be a poor predictor of underlying histopathology. Advances in immunohistochemistry provide the opportunity to re-examine this assumption. We classified pathological material from 79 FTLD brains, blind to clinical diagnosis, according to topography of brain atrophy and immunohistochemical characteristics. There were highly significant relationships to clinical syndrome. Atrophy was predominantly frontal and anterior temporal in FTD, frontal in FTD/MND, markedly asymmetric perisylvian in PNFA, asymmetric bitemporal in SD and premotor, parietal in PAX. Tau pathology was found in half of FTD and all PAX cases but in no FTD/MND or SD cases and only rarely in PNFA. FTD/MND, SD and PNFA cases were ubiquitin and TDP-43 positive. SD cases were associated with dystrophic neurites without neuronal cytoplasmic or intranuclear inclusions (FTLD-U, type 1), FTD/MND with numerous neuronal cytoplasmic inclusions (FTLD-U, type 2 ) and PNFA with neuronal cytoplasmic inclusions, dystrophic neurites and neuronal intranuclear inclusions (FTLD-U, type 3). MAPT mutations were linked to FTD and PGRN mutations to FTD and PNFA. The findings demonstrate predictable relationships between clinical phenotype and both topographical distribution of brain atrophy and immunohistochemical characteristics. The findings emphasise the importance of refined delineation of both clinical and pathological phenotype in furthering understanding of FTLD and its molecular substrate. 相似文献
994.
995.
The authors report a child with tracheoesophageal fistula secondary to disk battery ingestion. With respiratory compromise precluding expectant therapy and primary repair not achievable, gastric interposition and tracheal patch repair were undertaken in the acute phase. To the authors' knowledge, this is the first report of primary gastric interposition for traumatic tracheoesophageal fistula and suggest that immediate reconstruction can give an outcome at least as good as other reported approaches. 相似文献
996.
Okamoto E Nakamura M Akasaka Y Inoue Y Abe Y Chinzei T Saito I Isoyama T Mochizuki S Imachi K Mitamura Y 《Artificial organs》2007,31(7):538-541
We have developed internal battery systems for driving an undulation pump ventricular assist device using two kinds of lithium ion rechargeable batteries. The lithium ion rechargeable batteries have high energy density, long life, and no memory effect; however, rise in temperature of the lithium ion rechargeable battery is a critical issue. Evaluation of temperature rise by means of numerical estimation is required to develop an internal battery system. Temperature of the lithium ion rechargeable batteries is determined by ohmic loss due to internal resistance, chemical loss due to chemical reaction, and heat release. Measurement results of internal resistance (R(cell)) at an ambient temperature of 37 degrees C were 0.1 Omega in the lithium ion (Li-ion) battery and 0.03 Omega in the lithium polymer (Li-po) battery. Entropy change (DeltaS) of each battery, which leads to chemical loss, was -1.6 to -61.1 J/(mol.K) in the Li-ion battery and -9.6 to -67.5 J/(mol.K) in the Li-po battery depending on state of charge (SOC). Temperature of each lithium ion rechargeable battery under a discharge current of 1 A was estimated by finite element method heat transfer analysis at an ambient temperature of 37 degrees C configuring with measured R(cell) and measured DeltaS in each SOC. Results of estimation of time-course change in the surface temperature of each battery coincided with results of measurement results, and the success of the estimation will greatly contribute to the development of an internal battery system using lithium ion rechargeable batteries. 相似文献
997.
Thomson CE McCulloch M Sorenson A Barnett SC Seed BV Griffiths IR McLaughlin M 《The European journal of neuroscience》2008,28(8):1518-1535
Research in central nervous system (CNS) biology and pathology requires in vitro models, which, to recapitulate the CNS in vivo, must have extensive myelin and synapse formation under serum-free (defined) conditions. However, finding such a model has proven difficult. The technique described here produces dense cultures of myelinated axons, with abundant synapses and nodes of Ranvier, that are suitable for both morphological and biochemical analysis. Cellular and molecular events were easily visualised using conventional microscopy. Ultrastructurally, myelin sheaths were of the appropriate thickness relative to axonal diameter (G-ratio). Production of myelinated axons in these cultures was consistent and repeatable, as shown by statistical analysis of multiple experimental repeats. Myelinated axons were so abundant that from one litter of embryonic mice, myelin was produced in amounts sufficient for bulk biochemical analysis. This culture method was assessed for its ability to generate an in vitro model of the CNS that could be used for both neurobiological and neuropathological research. Myelin protein kinetics were investigated using a myelin fraction isolated from the cultures. This fraction was found to be superior, quantitatively and qualitatively, to the fraction recovered from standard cultures of dissociated oligodendrocytes, or from brain slices. The model was also used to investigate the roles of specific molecules in the pathogenesis of inflammatory CNS diseases. Using the defined conditions offered by this culture system, dose-specific, inhibitory effects of inflammatory cytokines on myelin formation were demonstrated, unequivocally. The method is technically quick, easy and reliable, and should have wide application to CNS research. 相似文献
998.
Cutuli D Foti F Mandolesi L De Bartolo P Gelfo F Federico F Petrosini L 《Psychopharmacology》2008,197(4):661-673
Rationale Experimental studies have investigated the effects of chronic donepezil treatment on the behavioral deficits elicited by reduced
activity or the loss of cholinergic neurons that occurs in aging or in models of dementia. However, few studies have analyzed
the effects of chronic donepezil treatment on the cognitive functions of intact animals.
Objectives The cognitive functions of healthy young rats treated chronically with the acetylcholinesterase inhibitor donepezil were evaluated
using a wide behavioral test battery.
Results Chronic treatment with donepezil ameliorated memory functions and explorative strategies, speeded up the acquisition of localizing
knowledge, augmented responsiveness to the context, and reduced anxiety levels. However, it did not affect spatial span, modify
motivational levels, or influence associative learning.
Conclusions The present findings show the specific profile of donepezil action on cognitive functions in the presence of unaltered cholinergic
neurotransmission systems. 相似文献
999.
Abstract: An implanted device is being designed and tested which has the main function of suppressing hyperreflexic bladder contractions by stimulating the pudendal afferent pathway. The concept is that the contractions will be detected by recording natural nerve signals. This is challenging because the changes in neural signal are very small (sub-microvolt), and the device must run 24 h per day, which means that for convenience it must be battery-powered. The energy budget is therefore tight. Furthermore, because the patient must be able to intervene to occasionally empty the bladder, a radio link is needed to the device. Within the EU project Healthy Aims, most aspects of the design have been made and tested. This includes the battery, battery charger, neural amplifier, and the package incorporating the Medical Implant Communication System (MICS) antenna, which are briefly described here. This article is a progress report. 相似文献
1000.
We report a case of spontaneous subdural haematoma due to ruptured intracranial infectious aneurysm, presenting with bilingual aphasia and illustrating differential language recovery. A 62-year-old right-handed bilingual gentleman, with a diagnosis of infective endocarditis, developed headache and became expressively aphasic in the English language. Three days later he was receptively and expressively aphasic in both English and Arabic. Cranial MRI scans showed a left-sided acute subdural haematoma with mass effect and midline shift. Contrast CT brain scans showed an enhancing speck adjacent to the clot and cerebral angiogram confirmed a distal middle cerebral artery aneurysm. He underwent image-guided craniotomy, evacuation of the subdural haematoma and excision of the aneurysm. Histopathological examination was consistent with an infectious intracranial aneurysm. Postoperatively his aphasia did not improve immediately. He had widened pulse pressure due to severe aortic regurgitation, confirmed on echocardiography. He underwent aortic valve replacement and mitral valve repair, following which his aphasia recovered gradually. Initially the recovery of his language was limited to Arabic. About a week later he recovered his English language as well. At 3-year follow-up he is doing well and has no neurological deficits. His aphasia has recovered completely. The present case is unique because of (a) presence of pure subdural haematoma, and (b) the differential susceptibility and recovery of native (L1) and acquired language (L2) in presence of a common pathology. The neurology of language in a bilingual is analysed and possible mechanisms discussed. 相似文献