核盘菌转代培养后生理特性变异初探

来自向日葵上的核盘菌(Sclerotinia sclerotiorum(Lib.)de·Bary)菌株Sun-1P经多次转代培养及冰箱保存后对有机氮(牛肉汁、蛋白胨、酵母膏)及淀粉的利用能力发生了显著改变。其中转代株Sun-1M对有机氮的利用与pH值及速效糖(葡萄糖)的存在有关系。离体致病性测定表明:Sun-1M对油菜、莴苣、向日葵及蚕豆等寄主仍具有致病性。

500kV变电站中220kV母联转代主进功能的实现

介绍了在500kV变电站中220kV母联开关转代主进开关的实现方法,提出了一次、二次设备的改造和操作方案,分析了采用母联转代方案的意义。

基于真双极接线的VSC-MTDC系统功率转代策略

随着国内柔性直流输电技术的快速发展,基于真双极接线的多端柔性输电技术将被越来越多地应用到实际工程中。不同于单极线路或换流器退出运行时,伪双极系统下会出现的线路过载和切机切负荷现象,对于运行方式更为灵活的真双极系统,由于非故障极可转代故障极的部分功率,使得电网可靠性和整体输电能力的提升成为可能。提出了一种适用于真双极多端柔性直流输电(VSC-MTDC)系统的功率转代策略:基于真双极系统正负极电网可独立控制功率的特点,当直流系统在非正常运行状况下出现非对称拓扑时,在确保各元件不越限的前提下使非故障极电网转代故障极电网部分功率,以提高VSC-MTDC系统的总传输容量。同时,基于张北±500 k V柔性直流输电示范工程,搭建了真双极四端柔性直流输电PSCAD/EMTDC仿真系统,对所提策略进行了有效性验证。

壬基酚对中国林蛙生长发育的转代效应

为了探讨成体中国林蛙(Rana chensinensis)暴露于壬基酚(nonylphenol,NP)后对其子代幼体生长发育和性腺分化的转代效应,将产卵前雌性成体分别暴露在浓度为2.5×10-7、1.25×10-7、5×10-8mol/L NP的水体中60 d,将产卵孵化后的26期蝌蚪做两种处理,第一种是在不含NP的水体中分组饲养,第二种是继续暴露在与母体暴露NP浓度相同的水体中,两种处理均至蝌蚪完全变态.结果显示:母体NP暴露处理后对子代蝌蚪的发育时间、体长和体重、雌雄比例的影响均无显著性差异,但对子代蝌蚪继续NP暴露处理的蝌蚪则出现了发育滞后、体长和体重减少、雌性比例升高的现象.说明在浓度为5×10-8～2.5×10-7mol/L NP范围的水体中,NP没有干扰成体雌性林蛙的卵子发育,对其子代的生长发育和性腺分化未形成影响.但这个浓度范围的NP可直接影响蝌蚪的生长发育和性腺分化.

蛹虫草生产性种源标准化连续转代研究

以AA、BB、CC、DD 4种蛹虫草生产性种源为材料,研究标准化连续转代液体菌种F1~F5代合成虫草素、腺苷和多糖的能力,对合成染料的脱色能力,脱氢酶活力和H2O2酶活力,及其子实体产量,虫草素、腺苷和多糖含量。结果表明:DD蛹虫草生产性种源不适宜标准化连续转代,菌种退化严重;而对于AA、BB、CC蛹虫草生产性种源而言,标准化连续转代5代内,菌种没有显著退化现象,可作为其大量繁育的有效方法,有助于工厂化批量生产,缩小经济成本,提高经济效益。

220kV旁路转代操作中线路纵联保护及主变保护的处理

在主接线形式为双母线带旁路的变电站操作中,转带操作占有很大比重,其操作的正确与否直接影响到系统的安全与稳定。本文以赵店站220kV线路转代操作为例,分析了220kV线路转代操作中高频通道的切换方法。

所谓代偿性眼球反转是不存在的-头部倾斜时眼的反应

目的：显示所谓的代偿性眼球反转(静态眼球反向扭转)是不存在的和描述当头部倾斜时发生的眼扭转运动。

NASA大型民用倾转旋翼机进展研究

倾转旋翼机是一种结合固定翼飞机和旋翼飞机双重优势的新型飞机,它具有速度快、油耗低、垂直起降等特点。在波音和贝尔公司联合研制的军用倾转旋翼机取得成功后,NASA试图在相关技术的基础上研制出一种90座、航程约为1200nmile、速度约为600km/h的新型先进民用倾转旋翼支线飞机,进而取代现役固定翼支线飞机。通过系统地搜集和科学地分析,明晰了NASA大型民用倾转旋翼机项目的内容、进展、风险和影响并对ARJ21支线项目提出早期预警。

输电线路光纤保护技术的应用及问题分析

分析了光纤保护与高频保护相比的优势,介绍了它在远跳回路、远传回路、双重化配置、旁路代路中的应用,并提出了光纤保护存在的通道通信中断的问题以及故障点的查找方法。

母兼旁开关特殊运行方式的探讨

沧州供电公司220 kV赵店变电站的110 kV母兼旁101开关,正常运行方式时做母联开关使用,特殊运行方式时可以转代或串代110 kV线路,本文就这两种特殊运行方式的相同和不同、优点和缺点进行分析比较,总结出转代和串代各适合的不同工作任务,以利于安全运行。

变电运行继电保护典型操作技术原则分析

对变电站运行中继电保护典型操作的基本技术原则、一次设备和二次设备操作顺序进行研究分析,形成变电运行和继电保护操作的典型范本。以此技术原则和范本为基础,指导生成标准化的操作票,可有效提升变电运行操作的安全水平和工作效率。

PPARs： diverse regulators in energy metabolism and metabolic diseases

The nuclear receptor PPARs are fundamentally important for energy homeostasis. Through their distinct yet overlapping functions and tissue distribution, the PPARs regulate many aspects of energy metabolism at the transcriptional level. Functional impairment or dysregulation of these receptors leads to a variety of metabolic diseases, while their ligands offer many metabolic benefits. Studies of these receptors have advanced our knowledge of the transcriptional basis of energy metabolism and helped us understand the pathogenic mechanisms of metabolic syndrome.

Endocytosis of adiponectin receptor I through a clathrin- and Rab5-dependent pathway

In eukaryotic cells, receptor endocytosis is a key event regulating signaling transduction. Adiponectin receptors belong to a new receptor family that is distinct from G-protein-coupled receptors and has critical roles in the pathogenesis of diabetes and metabolic syndrome. Here, we analyzed the endocytosis of adiponectin and adiponectin receptor 1 （AdipoR1） and found that they are both internalized into transferrin-positive compartments that follow similar traffic routes. Blocking clathrin-mediated endocytosis by expressing Eps15 mutants or depleting K^＋ trapped AdipoR1 at the plasma membrane, and K^＋ depletion abolished adiponectin internalization, indicating that the endocytosis of AdipoR1 and adiponectin is clathrin-dependent. Depletion of K^＋ and overexpression of Eps15 mutants enhance adiponectin- stimulated AMP-activated protein kinase phosphorylation, suggesting that the endocytosis of AdipoR1 might down-regulate adiponectin signaling. In addition, AdipoR1 colocalizes with the small GTPase Rab5, and a dominant negative Rab5 abrogates AdipoR1 endocytosis. These data indicate that AdipoR1 is internalized through a clathrin- and Rab5- dependent pathway and that endocytosis may play a role in the regulation of adiponectin signaling.

Associations between y-glutamyl transferase, metabolic abnormalities and inflammation in healthy subjects from a population-based cohort: A possible implication for oxidative stress

AIM: To examine the relationships between γ -glutamyltransferase (GGT), alanine-aminotransferase (ALT),aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stress marker (nitrotyrosine, NT) in subjects without any metabolic abnormalities from a population-based sample.METHODS: Two hundred and five subjects with normal body mass index (BMI), glucose tolerance, and without any metabolic abnormality were studied out of 1339subjects, without known liver diseases, alcohol abuse or use of hepatotoxic drugs, who are representative of the 45-64 aged population of Asti (north-western Italy).RESULTS: In all patients metabolic parameters and hs-CRP levels linearly increase from the lowest to the highest ALT and GGT tertiles, while in subjects without metabolic abnormalities, there is a significant association between fasting glucose, uric acid, waist circumference,hs-CRP, triglyceride values, and GGT levels. In these subjects, male sex, higher hs-CRP and glucose levels are associated with GGT levels in a multiple regression model, after adjustments for multiple confounders.In the same model, median NT levels are significantly associated with the increasing GGT tertile (β = 1.06;95%CI 0.67-1.45), but not with the AST and ALT tertiles.In a multiple regression model, after adjusting for age,sex, BMI, waist, smoking, and alcohol consumption, both NT (β = 0.05; 95%CI 0.02-0.08) and hs-CRP levels (β =0.09; 95%CI 0.03-0.15) are significantly associated with fasting glycemia.CONCLUSION: GGT, an easy, universally standardized and available measurement, could represent an early marker of sub-clinical inflammation and oxidative stress in otherwise healthy individuals. Prospective studies are needed to establish if GGT could predict future diabetes in these subjects.

Relationship between alanine aminotransferase levels and metabolic syndrome in nonalcoholic fatty liver disease

Objective： To investigate the relationship between alanine aminotransferase （ALT） levels and metabolic syndrome （MS） in nonalcoholic fatty liver disease （NAFLD）. Methods： A total of 26527 subjects who received medical health checkup in our hospital from January 2005 to July 2007 were enrolled in the study. The diagnosis of fatty liver was based on ultrasound imaging. MS was defined according to the criteria of the Adult Treatment Panel III. ALT, triglyceride （TG）, high density lipoprotein cholesterol （HDL-c）, fasting plasma glucose （FPG）, height, weight, waist circumference （WC）, systolic blood pressure （SBP） and diastolic blood pressure （DBP） were measured in each subject to analyze the relationship between MS and ALT activity Results： （1） The prevalence of NAFLD in men （30.94%） was significantly higher than that in women （15.65%）; （2） The incidence of MS in NAFLD （33.83%） was significantly greater than that in non-NAFLD （10.62%）; （3） Of the 6470 subjects with NAFLD, in the age-adjusted partial correlation analysis, there were statistically significant correlations between the ALT levels and most metabolic risk factors in each sex （P〈0.01）, except that ALT levels multiple stepwise regression analysis, SBP lost its significance, and had no correlation with HDL-c in women. Moreover, in the WC, body mass index （BMI）, age, DBP, TG and FPG were independently associated with ALT levels in both sexes （P〈0.05）. HDL-c remained significant and was independently related to ALT levels in men; （4） ALT levels were significantly higher in subjects with MS compared to those without MS （P〈0.001）. Mean ALT levels increased with the number of MS components in each sex （P〈0.05 for trend）. Conclusion： We found a strong relationship between ALT levels and MS in NAFLD and revealed that the cluster of MS components might be the predictor for ALT elevations.

Joint Source-Channel Bit Allocation Based on Expected End-to-End Distortion Model

An adaptive joint source channel bit allocation method for video communications over error-prone channel is proposed.To protect the bit-streams from the channel bit errors,the rate compatible punctured convolution(RCPC)code is used to produce coding rates varying from 4/5 to 1/2 using the same encoder and the Viterbi decoder.An expected end-to-end distortion model was presented to estimate the distortion introduced in compressed source coding due to quantization and channel bit errors jointly.Based on the proposed end-to-end distortion model,an adaptive joint source-channel bit allocation method was proposed under time-varying error-prone channel conditions.Simulated results show that the proposed methods could utilize the available channel capacity more efficiently and achieve better video quality than the other fixed coding-based bit allocation methods when transmitting over error-prone channels.

Extracting the Subsonic Anti-Symmetric Lamb Wave from a Submerged Thin Spherical Shell Backscattering Through Iterative Time Reversal

The extraction of the weakly excited anti-symmetric Lamb wave from a submerged thin spherical shell backscattering is very difficult if the carrier frequency of the incident short tone burst is not at its frequency of greatest enhancement. Based on a single channel iterative time reversal technique, a method for isolating the subsonic anti-symmetric Lamb wave is proposed in this paper. The approach does not depend on the form function of a thin shell and any other priori knowledge, and it is also robust in the presence of some stochastic noise. Both theoretical and numerical results show that the subsonic anti-symmetric Lamb wave can be identified, even when the carrier frequency of the incident short tone burst is away from the frequency of greatest enhancement. The phenomenon may also be observed even in the case that the subsonic anti-symmetric Lamb wave is submerged in the noise, other than the case with the Signal to Noise Ratio being less than 10 d B, when the amplitude of the noise is comparable with the specular wave. In this paper, each iteration process contains a traditional transmission and time reversal transmission steps. The two steps can automatically compensate the time delay of the subsonic anti-symmetric Lamb wave relative to the specular wave and within-mode dispersion in the forward wave propagation.

Novel insight into mechanisms of cholestatic liver injury

Cholestasis results in a buildup of bile acids in serum and in hepatocytes.Early studies into the mechanisms of cholestatic liver injury strongly implicated bile acidinduced apoptosis as the major cause of hepatocellular injury.Recent work has focused both on the role of bile acids in cell signaling as well as the role of sterile inflammation in the pathophysiology.Advances in modern analytical methodology have allowed for more accurate measuring of bile acid concentrations in serum,liver,and bile to very low levels of detection.Interestingly,toxic bile acid levels are seemingly far lower than previously hypothesized.The initial hypothesis has been based largely upon the exposure of μmol/L concentrations of toxic bile acids and bile salts to primary hepatocytes in cell culture,the possibility that in vivo bile acid concentrations may be far lower than the observed in vitro toxicity has far reaching implications in the mechanism of injury.This review will focus on both how different bile acids and different bile acid concentrations can affect hepatocytes during cholestasis,and additionally provide insight into how these data support recent hypotheses that cholestatic liver injury may not occur through direct bile acid-induced apoptosis,but may involve largely inflammatory cell-mediated liver cell necrosis.

Serial changes in expression of functionally clustered genes in progression of liver fibrosis in hepatitis C patients

AIM: To investigate the relationship of changes in expression of marker genes in functional categories or molecular networks comprising one functional category or multiple categories in progression of hepatic fibrosis in hepatitis C (HCV) patients. METHODS: Marker genes were initially identified using DNA microarray data from a rat liver fibrosis model. The expression level of each fibrosis associated marker gene was analyzed using reverse transcription-polymerase chain reaction (RT-PCR) in clinical biopsy specimens from HCV-positive patients (n = 61). Analysis of changes in expression patterns and interactions of marker genes in functional categories was used to assess the biological mechanism of fibrosis. RESULTS: The profile data showed several biological changes associated with progression of hepatic fibrosis. Clustered genes in functional categories showed sequential changes in expression. Several sets of clustered genes, including those related to the extracellular matrix (ECM), inflammation, lipid metabolism, steroid metabolism, and some transcription factors important for hepatic biology showed expression changes in the immediate early phase (F1/F2) of fibrosis. Genes associated with aromatic amino acid (AA) metabolism, sulfur-containing AA metabolism and insulin/ Wnt signaling showed expression changes in the middle phase (F2/F3), and some genes related to glucose metabolism showed altered expression in the late phase of fibrosis (F3/F4). Therefore, molecular networks showing serial changes in gene expression are present in liver fibrosis progression in hepatitis C patients. CONCLUSION: Analysis of gene expression profiles from a perspective of functional categories or molecular networks provides an understanding of disease and suggests new diagnostic methods. Selected marker genes have potential utility for biological identification of advanced fibrosis.