磁偏转线圈的一个简单模型

本文针对复杂的磁偏转线较圈实体,提出了一个简单的模型,使得对实际偏转线圈结构的测量和数值模拟都较为简单,利用该模型,对实际14＂彩色显像管（CRT）的偏转线圈绕线结构进行了测量,在此基础上对该偏转线圈所产生的偏转磁场,光栅畸变和会聚误差进行了数值模型,计算所得结果与测量值相比,光栅畸变的最大差为0．84％,会聚误差的最大误差为0．61mm.     

根据行为级模型方法对CMOS 图像传感器的BJPG 晶体管的分析

本文提出一种新的用于CMOS图像传感器像素的光电检测器－－双极结型光栅晶体管。由于引入p^ n注入结，光电荷的读出速率大大增加，改善了CMOS图像传感器的工作速率和响应灵敏度。尽管传统的光电集成电路的电路级模拟采用微电子集成电路的模拟方法，但是光电子集成电路不仅含有微电子器件和电信号还含有光电检测器和光信号，采用传统的集成电路模拟方法有其局限性。本文提出一种行为级模拟方法（光电子检测器设计的新方法，利用C、MATLAB和HSPICE等语言写出光电子器件的模拟器）来模拟分析双极结型光栅晶体管的特性。基于0.6μm CMOS工艺的分析结果表明双极结型光栅晶体管在不同栅氧化层厚度随栅压变化与传统光栅晶体管的特性一样，但光电流密度呈指数式增长且光电流密度增大，因此改善了CMOS图像传感器的工作速率和响应灵敏度。     

Ionic composition of rat airway surface liquid determined by X-ray microanalysis

The thin layer of liquid that lines the conducting airway epithelium, the airway surface liquid (ASL), is important for mucociliary clearance. Altered ionic composition and/ or volume of the ASL play a major role in the pathology of airway diseases such as cystic fibrosis. Since the ASL is a thin layer, it has been difficult to exactly determine its composition. The present paper describes two techniques that have been developed and used to study ASL composition: X-ray microanalysis of frozen hydrated rat trachea, and an ion-exchange (dextran) bead method, where dextran beads were placed on the airway epithelium to equilibrate with the ASL; the beads were then collected under silicone oil, dried and analyzed by X-ray microanalysis. The results from both frozen-hydrated specimens and from the dextran beads showed that ASL from rat trachea is hypotonic. Concentrations of Na, P, S, and K were higher in the frozen-hydrated ASL, in which mainly the mucus layer is analyzed, compared with the dextran bead method, in which mainly the periciliary liquid is sampled. Also the composition of rat nasal fluid was investigated by the dextran bead method. This fluid was somewhat hypertonic because of a high K concentration. The ionic composition of the nasal and tracheal fluid can be manipulated by cholinergic or alpha- or beta-adrenergic stimulation. Collecting ASL with dextran beads did not disturb the integrity of the airway epithelium. The ionic composition of the collected beads remained stable for several days during storage in silicone oil. It is concluded that X-ray microanalysis is a suitable method to determine the ionic composition of ASL.     

Effect of purification of carbon nanotubes on their electrocatalytic properties for oxygen reduction in acid solution

The oxygen reduction reaction has been investigated on acid-treated single-walled (SWCNT) and multi-walled carbon nanotubes (MWCNT) modified glassy carbon (GC) electrodes in acid media using the rotating disk electrode (RDE) method. Different acids were used for the carbon nanotube (CNT) purification. A systematic study was carried out to elucidate whether the metal catalyst impurities of CNTs play a role in the electroreduction of oxygen on the CNT modified GC electrodes. The surface morphology of the carbon nanotube samples was examined by transmission electron microscopy and the concentration of metal catalysts in the CNT materials was determined by energy dispersive X-ray spectroscopy. The acid-treated MWCNTs were also characterised by Raman and X-ray photoelectron spectroscopies. Aqueous suspensions of SWCNTs and MWCNTs used for GC surface modification were prepared in the presence of Nafion. The RDE results indicated that the acid-treated CNT modified GC electrodes are less active catalysts for oxygen reduction than as-received CNTs which could be explained by the absence of metal catalysts on the surface of purified CNTs.     

A decrease in the level of erythrocytes with micronuclei under the influence of pyrimidine and thiazolidine derivatives in the blood of persons who came under radiation exposure as a result of the accident at the Siberian Chemical Combine

Wild-type representatives of Francisella genus (F. tularensis, F. novicida, F. novicida-like, and F. philomiragia) produce S-type lipopolysaccharides (LPS) possessing different antigenic activity and common antigenic determinants in the core oligosaccharide. Electrophoretic analysis showed that F. philomiragia produced S-LPS containing two major molecular components with minor fractions between them, whereas S-LPS of F. tularensis, F. novicida, and F. novicida-like are characterized by the typical frequency distribution of molecules. A characteristic feature of Francisella LPS was the ability to form the dominant molecular components with similar electrophoretic mobility of major fractions of the original F. philomiragia LPS upon long storage in water solution. Natural virulent F. tularensis strains produce at least two types of S-LPS. Polysaccharide chains of type I S-LPS possess O-species-specific antigens, whereas the polysaccharide part of type II S-LPS has nonspecific antigenic epitopes. A decrease of F. tularensis virulence can be associated with impaired production of both S-LPS types or loss of S-LPS with O-species-specific antigenic activity.     

Differential migration of Th1 and Th2 cells--implications for vaccine and infection studies

We previously reported a synergistic interaction between leptin and cholecystokinin (CCK) to reduce food intake through CCK-A receptors in lean mice fasted for 24 h. To identify the activated neuronal pathways, we investigated changes in Fos expression in brain nuclei 2 h after single or combined intraperitoneal (i.p.) injections of leptin (120 microg/kg) and sulfated CCK-8 (3.5 microg/kg) in male lean mice (C57BL/6) fasted for 24 h using immunohistochemistry for Fos, the protein product of the early gene, c-fos. Leptin did not increase Fos expression in the brain compared with vehicle-treated mice. CCK increased the numbers of Fos-positive neurons in the nucleus of the solitary tract (NTS)/area postrema (AP), central nucleus of the amygdala (CeA) and, to a smaller extent, in the paraventricular nucleus of the hypothalamus (PVN) (5.2-, 2.3- and 0. 3-fold respectively). Injections of leptin-CCK further enhanced Fos expression by 40% in the PVN compared with that induced by CCK alone, but not in the other nuclei. Devazepide (a CCK-A receptor antagonist, 1 mg/kg, i.p.) prevented the increase in Fos expression induced by leptin-CCK in the PVN and by CCK alone in the PVN, CeA and NTS/AP. These results indicate that in fasted mice, i.p. injection of CCK increases Fos expression in specific brain nuclei through CCK-A receptors while leptin alone had no effect. Leptin in conjunction with CCK selectively enhanced Fos expression in the PVN. The PVN may be an important site mediating the synergistic effect of leptin-CCK to regulate food intake.     

Fusion of azurophil granules with phagosomes and activation of the tyrosine kinase Hck are specifically inhibited during phagocytosis of mycobacteria by human neutrophils

Pathogenic mycobacteria parasitize macrophages and reside within phagosomes, which do not fuse with lysosomal granules. Mycobacteria are also internalized by neutrophils, which possess at least two types of granules, specific and azurophil granules, the latter being specialized lysosomes. Here, we investigated the ability of mycobacteria to inhibit the fusion of these granules with their phagosomes in human neutrophils. It was found that when pathogenic (Mycobacterium kansasii and Mycobacterium avium) or nonpathogenic (Mycobacterium smegmatis and Mycobacterium phlei) mycobacteria were internalized by neutrophils, they induced the inhibition of azurophil granule fusion with phagosomes even when they were serum opsonized. In contrast, secretion of specific granule content and production of O2-, both of which contribute to the neutrophil bactericidal response, were triggered. Hck is a Src family tyrosine kinase associated with azurophil granules. During internalization of zymosan, azurophil granules fused with phagosomes and Hck was activated and translocated to the phagosomal membrane, whereas in neutrophils engulfing mycobacteria, Hck did not translocate and remained unactivated. The activation of the tyrosine kinase Fgr was not affected. These results indicate that 1) pathogenic and nonpathogenic mycobacteria trigger similar bactericidal responses in neutrophils, 2) phagocytosis and fusion of azurophil granules can be uncoupled by mycobacteria, and 3) Hck could be one of the key elements of the azurophil secretory pathway that are altered during phagocytosis of mycobacteria.