Disclosure in 3D of slit-membrane as well as -strands, and en-face basal lamina in situ of renal glomerulus of normal rats in embedment-free section transmission electron microscopy

With higher contrast and transparency due to the absence of epon and stereo-viewing effect due to thicker sections than conventional electron microscopy as methodological advantages, the renal glomerular slits were re-examined in embedment-free section electron microscopy. In addition to clear demonstration of strands bridging the slits in forms of ladders with highly irregular intervals and various extension-directions and length, this study disclosed clearly for the first time in the "section" TEM thin sheets which partially spanned the slit together with the strand-ladders. No strands were found to align in forms of typical zippers in normal kidney. Furthermore, en-face ultrastructure of the basal lamina in situ was clearly demonstrated in superimposed sites of the endothelial fenestrae with the slits.     

Astaxanthin delayed the pathogenesis of diabetic nephropathy in type 1 diabetic rats

This study was designed to investigate the protective effects of Astaxanthin (AST) in rats with diabetes mellitus(DM) induced by streptozotocin. SD rats were divided into control group (n = 5, only received normal saline), DM group(n = 8) and AST + DM group (n = 8; AST: 50 mg/kg/day). DM rats were induced by intraperitoneal injection ofstreptozocin (STZ, 65 mg/kg). Blood glucose level and body weight were determined at weeks 0, 2, 4, 6 and 8,respectively. At week 8, kidney function was determined, together with expression of P53 and dynamin-relatedprotein-1 (Drp1) by Western blot analysis and immunofluorescence. AST led to increase of body weight in rats withDM. AST + DM group showed a significant decrease in blood glucose level at week 4 compared with DM group(P < 0.05). AST improved renal function and significantly reduced expression of P53 and Drp1 in DM rats. Inaddition, AST can effectively reduce the blood glucose in DM rats, and delayed the pathogenesis of diabeticnephropathy. Such delay mediated by AST may be associated with the downregulation of Drp1 and P53.     

RM1-20-5中等延时熔断器

中等延时熔断器在过电流保护方面有着特殊的功能，具有耐脉冲电流冲击，过电流时又能较快熔断的特点，因而能较好地保护电子设备与仪器的安全，RM1-20-5型中等延时熔断器采用高熔点金融与低熔点金属所组成的复合熔丝结构而达到中等延时效果。作为电路中过电流和短路电流保护器，它可被广泛用于各种电子仪器与设备中。     

EN 1993-1-6标准中的壳体失稳设计方法简述

数值模拟计算能力和水平的提高为外压壳体失稳复杂理论应用到实际设计方法中提供了可能,应用数值模拟进行设计逐步在标准中引用并不断完善。与其他标准相比, EN 1993-1-6（2007）《壳结构的强度与稳定》对数值模拟在设计上的应用给出了更为详细的规定。对壳体失稳设计,EN 1993-1-6提出了3种不同的设计方法：公式计算方法、LBA-MNA方法以及GMNIA方法。为研究EN 1993-1-6的壳体数值模拟设计方法的可行性,对其进行了简要介绍,并通过10组算例与GB 150,ASME Ⅷ-2,EN 13445等标准进行对比,结果显示,EN 1993-1-6的数值模拟的设计许用值均高于GB 150的设计许用值,而与ASME Ⅷ-2和EN 13445相比,设计许用值则比较接近,这表明EN 1993-1-6规定的数值模拟设计方法有着比GB 150更好的经济性,是一种先进的设计方法。     

5L-40/8-1压缩机故障分析与改进

对5L压缩机常见故障进行分析,并提出改进措施。     

一种3-2-1正交布置的6自由度并联微动机器人分析

对一种 3 2 1正交布置的 6自由度并联微动机器人进行了分析。给出这种特殊构型并联微动机构的位置正解和逆解的显示方程 ,同时给出了该并联微动机构的力雅克比矩阵和速度雅克比矩阵 ,对速度和力传递的各向同性指标进行了分析。指出该并联微动机构可以产生 2种相互解耦的复合运动 ,一种是 3 DOF的Z tilts运动 ,另外一种是其相应的 3 DOF平面一般运动。     

工程数字化系统在番禺4—2／5—1调整项目组的应用

工程数据中心系统的成功上线,标志着中海石油工程建设领域一个全新时代的开始。本文首先分析了工程数字信息化的必然性;其次,概述了番禺4-2／5—1调整项目的情况;最后,就工程数字化系统在番禺4—2／5—1调整项目组的应用进行了深入的探讨。     

A generator for calibrating current and voltage probes of the Angara-5-1 facility

A small-size high-voltage generator forming single pulses is described. The generator contains reference current and voltage probes and is intended for calibrating current and voltage probes placed in the electromagnetic-pulse transmission section and loading unit of the Angara-5-1 facility. When the charging voltage is at maximum (40 kV), the current amplitude in the short-circuit mode is ～28 kA. The half-height current pulse duration is ～140 ns.     

Cavitation erosion of titanium and Ti-6A1-4V: Effects of nitriding

The cavitation erosion behavior of titanium and Ti-6Al-4V alloy, with and without nitriding, was studied using scanning electron microscopy, weight change measurements and microhardness measurements. It is shown that a nitriding treatment at 720 °C for 8 h yields substantial improvement in cavitation erosion behavior. In general, under cavitation loading, nitriding has the effect of introducing brittle fracture whereas the unnitrided specimens show ductile fracture.     

一种6-6UHU并联机器人的设计和实验研究

研制了一种新型结构的大工作空间 6 6UHU并联机器人。通过对虎克铰摆角极限对机器人工作空间的影响研究 ,在机构设计上解决了杆间干涉和下关节极限问题 ,简化了干涉检测算法 ,降低了运动控制算法的复杂性 ,并且增大了工作空间。研制出基于DSP的多轴控制器PMAC卡的交流伺服电机控制系统和实验系统 ,并进行了实验。给出了不同姿态下该机器人的工作空间分析。仿真数据和实验结果表明 ,所研制的新型 6 6UHU并联机器人 ,结构精巧 ,工作空间大 ,动平台的倾斜角达到 4 5° ;同时具有高刚度、高精度、操作性能好等特点。干涉防护系统能保证机器人在大工作空间机动运行情况下的安全     

Co-regulator NCOA5 and cancer

NCOA5 encodes a co-regulator for estrogen receptors (ERα and ERβ), orphan nuclear receptors (REV-ERBαand REV-ERBβ) and liver X receptor. It can influence many cellular processes by either promoting or inhibiting geneexpression through its two important functional motifs: LxxLL (co-activator) and ΦxxΦΦ (co-repressor). Manyreports have revealed the important roles of NCOA5 in diseases, such as diabetes, reproductive defects andautoimmune disease. In this review, we focus on its function in cancers and summary the current research progressesregarding its different roles in various cancers.     

CW6Mo5Cr4V2钢与W6Mo5Cr4V2钢的性能比较

比较了CW6Mo5Cr4V2钢与W6Mo5Cr4V2钢的性能。试验表明,在相同淬火温度下,CW6Mo5Cr4V2淬回火硬度和红硬性明显高于W6Mo5Cr4V2,淬火晶粒比W6Mo5Cr4V2粗,冲击功比W6Mo5Cr4V2低。CW6Mo5Cr4V2在1160-1200℃淬火可获得优良的综合机械性能。在1220℃以上淬火,CW6Mo5Cr4V2过热倾向显著,冲击功急剧下降。碳和钨钼含量的变化对CW6Mo5Cr4V2淬火温度的影响很大。要使CW6Mo5Cr4V2淬火易于控制,必须收窄CW6Mo5Cr4V2主要成分范围。CW6Mo5Cr4V2较适合于切削速度较高的刀具。     

热处理对21-6-9钢性能及显微组织影响

热处理工艺对单相高强度21-6-9奥氏体不锈钢显微组织及力学性能影响显著。本文在固定其他热处理工艺参数情况下,分别对固溶处理温度,固溶冷却方式,时效处理温度进行研究,结果表明:固溶温度对21-6-9钢低温韧性及晶粒尺寸影响显著,1050℃是其最佳固溶处理温度;固溶冷却方式对其力学性能影响不明显,但对其晶粒尺寸有较大影响,其中水冷处理方式能够使21-6-9钢得到尺寸均匀且细小的晶粒组织;时效温度对其低温韧性存在影响,表现为时效温度过高(≥600℃)会导致低温韧性明显下降。经过适当的热处理工艺处理,实现21-6-9钢屈服强度不低于438MPa,断口伸长率47%,断口收缩率不低于75%,同时具有良好的塑性及低温韧性。     

6-3-3并联机构尺度的优化综合

提出了以满足6-3-3并联机构使用功能为准则的尺度综合优化建模方法,即以功能要求的任务轨迹为动平台运动规划路径,以尺度参数和任务轨迹在工作空间的定位参数为设计变量,以机构空间结构尽可能紧凑,而工作空间尽可能大为目标函数、工作空间涵盖任务轨迹、主动件移动范围和关节转角不超过设定极限值为约束,建立优化模型并通过软件编程实现该模型的求解。最后,给出了一个算例。     

Effect of microRNA-143-3p-mediated CTNND1 on the biological function of lung cancer cells

Lung cancer poses a serious threat to human life with high incidence and miRNA is an important biomarkerin tumors. This study aimed to explore the effect of miR-143-3p on the biological function of lung cancer cells and theunderlying mechanism. Eighty-seven samples of lung cancer tissues and 81 samples of tumor-adjacent tissues frompatients undergoing radical lung cancer surgery in our hospital were collected. The lung cancer cells and lung fibroblastcells (HFL-1) were purchased, and then miR-143-3p-mimics, miR-NC, si-CTNND1, and NC were transfected intoA549 and PC-9 cells to establish cell models. MiR-143-3p and CTNND1 expression levels were measured by the qRTPCR,Bax, Bcl-2, and CTNND1 expression levels by the Western Blot (WB), and cell proliferation, invasion, andapoptosis by the MTT assay, Transwell assay, and flow cytometry. Dual luciferase report assay was used to determinethe relationship between miR-143-3p and CTNND1. In this study, miR-143-3p was lowly expressed in lung cancerand CTNND1 was highly expressed in lung cancer. The overexpression of miR-143-3p inhibited cell proliferationand invasion, promoted cell apoptosis, significantly increased Bax protein expression, and decreased Bcl-2 proteinexpression. The inhibition of CTNND1 led to opposite biological characteristic in cells. The dual luciferase reporterassay demonstrated that miR-143-3p was a target region of CTNND1. Such results suggest that miR-143-3p can inhibitthe proliferation and invasion of lung cancer cells by regulating the expression of CTNND1 and promote the apoptosisof lung cancer cells, sott is expected to be a potential target for lung cancer.     

Effects of aging and HIF-1alpha deficiency on permeability of hippocampal vessels

We examined age-related changes in the blood-brain barrier (BBB) of neural cell-specific hypoxia inducible factor-1alpha (HIF-1alpha) deficient mice, which showed hydrocephalus with neuronal cell loss, to investigate an effect of neural cell-specific HIF-1alpha deficiency or hydrocephalus on vascular function. Vascular permeability of horseradish peroxidase (HRP) and binding of cationized ferritin (CF) particles to the endothelial cell luminal surface, as a marker of glycocalyx, were investigated. The thickness of CF-labeled glycocalyx was significantly decreased in the cortex in mutant mice compared with that of control mice, although it was not paralleled by increased vascular permeability. In addition, strong staining for HRP was seen around vessels located along the hippocampal fissure in 24-month-old mutant mice. The reaction product of HRP appeared in an increasing number of the endothelial cell abluminal vesicles and within the thickened basal lamina of arterioles in the hippocampus, showing increased vascular permeability. There were no leaky vessels in 10-week-old mutant mice or 10-week-old and 24-month-old control mice. These findings suggest the necessity of two factors, aging and hydrocephalus, for BBB dysfunction in HIF-1alpha deficient mice.     

Contrast analysis of cryo-images of n-paraffin recorded at 400***kV out to 2·1 Å resolution

N-Paraffin was used as a test specimen for evaluating the relative merits of 400-kV versus 100-kV electron microscopy in recording data for electron crystallographic analysis of beam-sensitive materials. The parameter used for comparison, the relative contrast R, is the ratio of amplitudes from the computed Fourier transform of images and amplitudes from an electron diffraction pattern from the same crystal. R will thus be a measure of the contrast from an experimental image relative to that of a perfect image. Electron diffraction patterns and bright-field images were recorded at 400 kV at a specimen temperature of ?167°C. Using the flood-beam imaging technique the best R-value is 0 08 for all reflections in the resolution zone from 4 to 3 Å. This value is equivalent to that found at 100 kV. In the resolution zone from 3 to 2 Å we have found R — 0 02. Using the spot-scan imaging technique, on the other hand, R was measured to be 0·42 for the reflections between 4- and 3-Å resolution. This amount of relative contrast is 1·7 times that observed at 100 kV. Reflections at 3–2 Å displayed an R-value of 0 05. Besides obtaining higher R-values when applying the spot-scan imaging technique at 400 kV, we observe a higher yield of images with isotropic diffraction and/or higher resolution reflections. Various contrast-attenuating factors, including the modulation transfer function of the photographic film and the cryo-holder, envelope functions for spatial and temporal coherence and lens and high-tension instabilities, the contrast transfer function and lastly the radiation damage effects, have been considered in interpreting the observed image contrast. Overall, use of 400 kV in combination with spot-scan does offer important improvements in contrast levels, which can be very useful in determining the three-dimensional structure from protein crystals.     

五自由度纳米级定位工作台的设计研究

提出一种新型的五自由度精密定位平台的工作原理及其设计方法。工作台采用柔性导向机构实现平移及转动功能,采用压电陶瓷作为驱动元件,外置纳米级电容传感器作为位移量测量反馈元件,采用数字PID控制方法,可以实现纳米级精度的定位。给出了多种形式柔性导向机构刚度计算公式及设计实例。