Serum enzyme abnormalities in protein energy malnutrition

A semi-quantitative right coronary artery score (RCA score) was derived from the ratio of the number of the major left ventricular branches of the right coronary artery to the total of the right coronary and left circumflex arteries, to stratify the extent of perfusion in patients with right coronary artery dominance. Thirty-seven patients with one-vessel coronary disease involving a dominant right coronary artery proximal to the left ventricular branches were selected for study. Thallium scintigraphy was performed after right intracoronary injection in 11 patients, and 26 patients underwent conventional stress thallium scintigraphy (24 exercise thallium and two dipyridamole thallium scintigraphy). Thallium scores of perfusion region size after right intracoronary thallium injection and perfusion defect size in stress thallium studies were quantitated from planar thallium images. Both the RCA score and the regional thallium scores spanned over a wide range. The RCA score (range 0.23-0.85) correlated best with the posterior (70 degrees left anterior oblique view) plus lateral segment (40 degrees left anterior oblique view) thallium score (r = 0.88 and 0.53 for intracoronary and stress thallium studies respectively). It also correlated with the summed thallium scores in the posterior, lateral, apical and inferior segments (r = 0.73 and 0.54 respectively) but not with thallium scores in the apex or inferior segment alone. The proposed RCA score quantitates the variable posterolateral perfusion territory of the right coronary artery, and could stratify the area of myocardium at risk from coronary stenosis in the majority of patients with right coronary dominance.     

ZrO_2（Y－TZP）－Si_3N_4复合材料中抑制ZrN生成研究

研究了气氛加压烧成ＺｒＯ２（Ｙ－ＴＺＰ）－Ｓｉ３Ｎ４复合材料中抑制ＺｒＮ生成工艺问题，相组成分析表明：无论添加２０ｗｔ％工业ＺｒＯ２或者Ｙ－ＴＺＰ（３ｍｏｌ％Ｙ。Ｏ。）的氯化硅复合材料，在低于１８５０℃，３ＭＰａｋ气压力下烧成，表面无ＺｒＮ生成．通过加入有效的烧结助剂（Ｙ。Ｏａ＋ＡＩ。Ｏｓ）、增加埋粉中ＳＩＯ分压以及增加保护气氛氮气压力，适当的烧成条件等工艺措施可有效地抑制ＺｒＮ的生成．实验还证实了ＺｒＮ很容易氧化，含有ＺｒＮ的ＺｒＯ。（Ｙ－ＴＺＰ）－ＳｉｓＮ。复合材料试样经９００℃，０．ｓｈ热处理已粉碎性裂开．     

Beneficial effects of S-adenosyl-L-methionine on blood-brain barrier breakdown and neuronal survival after transient cerebral ischemia in gerbils

In the present study, the effect of bradykinin on basal and precontracted mouse-isolated trachea was investigated. In basal conditions mouse-isolated tracheal rings do not respond to bradykinin. However, when the tracheal rings were precontracted with carbachol (10(-7) M) a relaxation with bradykinin (3 x 10(-9)-3 x 10(-7)) was found. The maximal response amounted 69.7+/-4.1% (n=15) with a pD2 value of 7.2+/-0.21. The selective bradykinin B2 receptor antagonist HOE 140 (10(-10)-10(-8) M) antagonized the bradykinin-induced relaxation, while the bradykinin B1 receptor antagonist des-Arg9-Leu8-bradykinin (10(-6) M) had no influence. The selective bradykinin B1 receptor agonist des-Arg9-bradykinin (10(-6) M) caused a small relaxation (8.4+/-2.5%, n=6), which could be antagonized completely by the selective bradykinin B1 receptor antagonist des-Arg9-Leu8-bradykinin (10(-6) M) while addition of the selective bradykinin B2 receptor antagonist HOE 140 (10(-8) M) was without effect. In the presence of indomethacin (10(-6) M) the relaxation of bradykinin was completely abolished. Pretreatment of the tracheal rings with capsaicin, or the presence of the selective NK1 receptor antagonist RP 67851 (10(-6) M) or the presence of the nitric oxide synthase inhibitor L-NAME (3 x 10(-4) M) had no effect on the bradykinin-induced relaxation. In conclusion, these results demonstrate that the mouse-isolated tracheal is a preparation in which bradykinin exerts a relaxant response via stimulation of bradykinin B2 receptors. This response is probably mediated by prostaglandins.     

复杂系统建模——高维特征空间变量法

本文运用模式识别技术提出了一种分析和选择复杂系统变量的方法.运用该方法使得系 统的建模和控制简化.本文以复杂碳化过程作为实例,用模式识别技术对其内在规律进行分 析,找出了温度分布与结晶质量的定量关系.在此基础上,建立了碳化过程的动态模型.实践 表明,该模型与实际过程基本吻合,并已取得明显经济效益.     

Growth and characterization of barium copper oxalate single crystals in gels

Barium copper oxalate was grown in silica hydrogel at ambient temperature. The effect of various parameters like gel pH, gel density, gel aging and concentrations of reactants on the growth of these crystals was studied. The crystals grown were characterized by chemical analysis, X-ray powder diffractometry, infrared spectroscopy, thermogravimetric and differential thermal analysis. The results of these observations are described and discussed.     

Application of the method of moments to acoustic scattering from fluid-filled cylinders using three different formulations

In this work, we present three different formulations, namely the pressure field integral equation formulation (PFIE), the velocity field integral equation formulation (VFIE), and the combined field integral equation formulation (CFIE) for solving acoustic scattering problems associated with two-dimensional fluid-filled bodies of arbitrary cross-section. In particular using the boundary conditions on the surface of the body, two equivalent problems, each valid for the outside and inside regions of the scatterer, are derived. By properly selecting the associated equations for these equivalent problems, the three different formulations are derived. The PFIE, VFIE, and CFIE are then solved by approximating the cylindrical cross-section by linear segments and employing the method of moments. Further, it is shown that the moment matrices generated by the PFIE and VFIE are ill-conditioned at resonant frequencies of the cylinder, whereas the CFIE generates a well-conditioned matrix at all frequencies. The solution techniques presented in this work are simple, efficient and applicable to truly arbitrary geometries. Numerical results are presented for certain canonical shapes and compared with other available data.     

CMOS artificial subretinal chip for natural light illumination

A novel CMOS oscillating pixel array for subretinal prosthesis used in natural light illumination is presented. Its prototype chips are fabricated in a standard 0.6 /spl mu/m CMOS technology. Experimental results show the device can deliver effective self-oscillation for subretinal electrical stimulation.