基于多孔基片聚合物注入方法的薄膜固体氧化物燃料电池无支撑薄膜制备研究

为了控制薄膜固体氧化物燃料电池阳极的小孔尺寸,该研究提出了一种工艺简便的聚合物注入方法。首先,将液体聚苯乙烯以一定的压力注入到多孔氧化镍-氧化钇稳定的氧化锆(NiO-YSZ)基片;然后,经过机械切割,利用溅射法在阳极基片上沉积 300 nm 厚的电极薄膜;最后,利用热解法将 基片孔隙的聚苯乙烯移除,完成多孔阳极基片上的电极薄膜制备。利用该法获取的 NiO-YSZ 基片具有更好的小孔尺寸可控性,同时可以实现无支撑薄膜的制备,从而显著提高大面积薄膜固体氧化物燃料电池的生产效率。     

锂离子电池合金负极材料的研究进展

综述了锂离子电池合金负极材料的研究进展,包括铝基、锡基以及硅基合金负极材料;对合金负极材料研发中存在的问题和贮锂机制进行了分析.活性粒子纳米化、多重缓冲结构和多组分复合方式是合金负极材料的发展方向.     

Few patients with "chronic prostatitis" have significant bladder outlet obstruction

Apolipoprotein E (apoE) is one of the amyloid associated proteins that is found in the amyloid plaque of Alzheimer's disease and systemic amyloidosis. ApoE might play an important part in the etiology of Alzheimer's disease by functioning as a "pathologic chaperone" to promote the formation of amyloid filaments. In this study, we investigated whether apoE is associated with amyloid deposits of primary localized cutaneous amyloidosis using immunohistochemistry, immunogold electron microscopy, and immunoblotting. The subjects consisted of 12 patients with lichen amyloidosus and one patient with macular amyloidosis. Light microscopically, amyloid deposits in the dermal papillae were round in shape and stained with Congo red. Immunohistochemically, apoE was detected in amyloid deposits in all the cases examined. Immunogold electron microscopy showed apoE immunoreactivity on the amyloid deposition. Immunoblots of amyloid-positive skin showed 35K and 14K proteins, which were taken to be apoE and its fragment, respectively. In normal skin extract, only the 35K protein was detected by the anti-human apoE. Moreover, the intensity of the amyloid-positive skin sample was stronger than that of the normal skin sample. Monoclonal anti-cytokeratin antibody reacted with the 45K protein of the amyloid-positive skin extract. These results indicate that apoE is a component of primary localized cutaneous amyloidosis, and that it might play an important role in primary localized cutaneous amyloidosis.     

Coupled gating between individual skeletal muscle Ca2+ release channels (ryanodine receptors)

Excitation-contraction coupling in skeletal muscle requires the release of intracellular calcium ions (Ca2+) through ryanodine receptor (RyR1) channels in the sarcoplasmic reticulum. Half of the RyR1 channels are activated by voltage-dependent Ca2+ channels in the plasma membrane. In planar lipid bilayers, RyR1 channels exhibited simultaneous openings and closings, termed "coupled gating." Addition of the channel accessory protein FKBP12 induced coupled gating, and removal of FKBP12 uncoupled channels. Coupled gating provides a mechanism by which RyR1 channels that are not associated with voltage-dependent Ca2+ channels can be regulated.     

Humane and practical implications of using carbon dioxide mixed with oxygen for anesthesia or euthanasia of rats

A series of studies was undertaken to determine whether CO2 can be used as a humane as well as practical agent for euthanasia or anesthesia of rats. Human volunteers rated the degree of discomfort associated with breathing 50 to 100% CO2 mixed with oxygen. Increasing concentrations of CO2 were judged as progressively more noxious, from "highly unpleasant" for 50% CO2 to "painful" for 100% CO2. The practical aspects of anesthesia and euthanasia with 50 to 100% CO2 were studied, using male Sprague Dawley rats. Time to anesthesia and death were inversely related to CO2 concentration, as were the frequency and severity of adverse reactions, including seizures and hemorrhaging from the nose. The severity of edema and hemorrhage, which were observed on histologic examination of the lungs of all rats euthanized with CO2, were greatest in the animals exposed to the lowest concentrations. There were no significant effects of CO2 concentration on time to recumbency or recovery, and there were no significant effects of precharging versus not precharging the chamber on any of the parameters studied. It was concluded that, although CO2 can be used in a humane manner, the concentrations that are least likely to cause pain and distress are associated with the longest times to anesthesia and death, highest incidence of unwanted side effects, and most severe histologic changes in the lungs. Acceptably humane and reasonably practical euthanasia or anesthesia can be achieved using a nonprecharged chamber and a low gas flow rate so that conscious animals are never exposed to CO2 concentrations > 70%.     

Risk factors and prevalence of antibodies against hepatitis A virus (HAV) in children from day-care centers, in Goiania, Brazil

A comparative interim analysis was performed of clinical parameters, computed tomographic (CT) scan results and technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (SPET) findings obtained within 12 h of acute supratentorial ischaemic infarction. First, the applicability for SPET semiquantification in this study of the "method of Mountz", simultaneously accounting for extent and degrees of hypoperfusion by expressing deficits as millilitre of zero perfusion, was considered. Next, the relative contributions of perfusion SPET and CT scan in the acute stage of ischaemic infarction were compared in 27 patients (mean age 68.8 years). Finally, the correlation of SPET lesions with clinical parameters at onset was evaluated. The method of Mountz represents a workable, accurate virtual parameter, with the assumption that the contralateral brain region remains uninvolved. Interobserver reproducibility in 12 SPET studies, with lesions varying between 6 and 369 cc, showed a correlation coefficient r of 0.99. In practice, because of inconstant distribution of activities in the brain, the method can only be applied slice by slice and not on the total global volume. While the mean delay since the onset of symptomatology was approximately 7 h for both SPET and CT scan, SPET showed lesions concordant with the clinical neurological findings in 100% and CT scan in only 48%. One could hypothesize that SPET examinations performed later would show larger functional defects, because of the development of additional functional changes secondary to biochemical alterations. However, in this regard no statistically significant differences were found between two subproups, taking the median of delay before SPET examination as cut-off.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fluorine-18 deoxyglucose uptake in sarcoidosis measured with positron emission tomography

Regional pulmonary glucose metabolism (MRglu; mumol h-1 g-1), extravascular lung density (D(EV); g cm-3) and vascular volume (VB; ml cm-3) were measured in a single midthoracic transaxial slice (approximately 2 cm thick) using position emission tomography (PET) in seven patients with histologically proven sarcoidosis. The measurements were repeated 1-7 months later after steroid therapy (in two cases, no treatment) in order to assess MRglu as an index of inflammation and relate it to routine pulmonary function tests, chest radiography and serum angiotensin converting enzyme (SACE) levels. MRglu was computed from serial lung scans and peripheral venous blood samples for 60 min following an i.v. injection of 18F-2-fluoro-2-deoxy-D-glucose (18FDG). Both MRglu (which was increased in six of seven patients) and elevated SACE levels returned to normal in those patients treated with high-dose steroids. Regional vascular volume was normal in six of seven cases and did not change significantly with therapy. The high tissue density measured in all patients decreased significantly in two of three patients treated with 40 mg prednisolone daily. The abnormal MRglu observed in active sarcoidosis becomes normal pari passu with SACE levels during high-dose steroid therapy. We conclude that MRglu measured with 18FDG and PET may reflect "disease activity" in sarcoidosis in quantitative terms (per gram lung tissue) and in respect of disease distribution.     

波形分集阵雷达抗欺骗式干扰技术

本文从单基地雷达抗干扰的应用需求出发,分析了现有单基地雷达体制抗干扰的现状以及面临的困难.针对欺骗式干扰对抗的难题,提出了基于新体制波形分集阵雷达的抗主瓣方向欺骗式干扰思路,利用频率分集阵（Frequency Diverse Array,FDA）多输入多输出（Multiple-Input Multiple-Output,MIMO）雷达发射维自由度,实现真实目标和转发假目标在发射维度的区分,在部分先验知识的条件下,初步论证了FDA-MIMO雷达抗欺骗式干扰特别是主瓣欺骗式干扰的可行性.同时考虑转发式欺骗干扰在时间维的伪随机特性,提出了基于多假设检验的干扰样本挑选方法,大大提高了干扰协方差矩阵的估计性能.最后给出了FDA-MIMO雷达抗主瓣欺骗式干扰的分析与仿真结果.     

Alpha1-adrenergic receptors in human spinal cord: specific localized expression of mRNA encoding alpha1-adrenergic receptor subtypes at four distinct levels

alpha1-Adrenergic receptors (alpha1ARs) are important in lower urinary tract syndromes such as benign prostatic hypertrophy and bladder irritability. Spinal cord alpha1ARs have been postulated to play a role in modulating these diseases, yet alpha1AR subtype (alpha1a, alpha1b, alpha1d) neuronal localization in human spinal cord has not been described. We therefore tested the hypothesis that alpha1AR subtype distribution varies according to specific spinal cord tract and level. In situ hybridization was performed to identify cell bodies containing alpha1AR subtype mRNA at four levels of human spinal cord (cervical enlargement, thoracic, lumbar, sacral). alpha1AR mRNA is present in ventral gray matter only (ventral>dorsal; sacral>lumbar=thoracic>cervical). Signaling cell bodies were detected in anterior horn motor neurons at all levels; dorsal nucleus of Clarke and intermediolateral columns in cervical enlargement, thoracic and lumbar spinal cord regions; and parasympathetic nucleus in sacral spinal cord. Although all three alpha1AR subtypes are present throughout human spinal cord, alpha1d mRNA predominates overall. If confirmed at a protein level, these findings may contribute to the development of new therapeutic strategies in the treatment of several human diseases.     

Stabilization of a proteolytically sensitive cytoplasmic recombinant protein during transition to downstream processing

The influence of aeration and glucose feeding on the stability of recombinant protein A in Escherichia coli during the transition period from a fed-batch cultivation to downstream processing was studied. Neither interruption of the feeding under aerobic conditions nor anaerobic conditions in presence of glucose could stabilize protein A completely and the intracellular ATP pool did not decrease to less than 0.75-1 mM by this treatment. On the other hand, the absence of both oxygen and glucose resulted in a decrease of the ATP pool to less than 0.5 mM and almost complete stabilization of protein A. The decrease of ATP was more severe when sulfite was used instead of nitrogen gas to create anaerobic conditions in presence of glucose. This also resulted in nearly complete stabilization of protein A, which might be explained by an inhibiting effect of sodium sulfite on fermentation. Therefore, protein stabilization and decrease of the ATP pool were correlated in experiments in vivo. The concentrations of ADP and AMP increased during starvation and may also play a role in stabilization of the protein in vivo. ATP may be a limiting factor of proteolysis also during further steps of downstream processing. Its concentration decreases by 80-90% during harvesting and centrifugation of biomass and even further during disruption of cells. However, neither addition nor regeneration of ATP in cell disintegrate was enough to restore degradation of protein A, indicating that an additional factor limits proteolysis in vitro.