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41.
As one of the common and serious chronic complications of diabetes mellitus (DM), the related mechanism of diabetic retinopathy (DR) has not been fully understood. Müller cell reactive gliosis is one of the early pathophysiological features of DR. Therefore, exploring the manner to reduce diabetes-induced Müller cell damage is essential to delay DR. Thioredoxin 1 (Trx1), one of the ubiquitous redox enzymes, plays a vital role in redox homeostasis via protein–protein interactions, including apoptosis signal-regulating kinase 1 (ASK1). Previous studies have shown that upregulation of Trx by some drugs can attenuate endoplasmic reticulum stress (ERS) in DR, but the related mechanism was unclear. In this study, we used DM mouse and high glucose (HG)-cultured human Müller cells as models to clarify the effect of Trx1 on ERS and the underlying mechanism. The data showed that the diabetes-induced Müller cell damage was increased significantly. Moreover, the expression of ERS and reactive gliosis was also upregulated in diabetes in vivo and in vitro. However, it was reversed after Trx1 overexpression. Besides, ERS-related protein expression, reactive gliosis, and apoptosis were decreased after transfection with ASK1 small-interfering RNA in stable Trx1 overexpression Müller cells after HG treatment. Taken together, Trx1 could protect Müller cells from diabetes-induced damage, and the underlying mechanism was related to inhibited ERS via ASK1.  相似文献   
42.
泛素化是存在于真核生物中一种重要的翻译后修饰过程,参与调控包括蛋白质降解在内的多种生命活动。实现这一调控过程需要将一个由76个氨基酸组成的泛素蛋白共价连接到底物蛋白上。同时,泛素本身也存在多种翻译后修饰,包括泛素化、磷酸化、乙酰化等,进一步丰富了泛素的修饰类型,决定了底物蛋白不同的命运。近年来,伴随着第65位丝氨酸磷酸化泛素蛋白参与调控线粒体自噬这一突破性进展,泛素蛋白其余磷酸化位点的功能研究也获得越来越多的关注。本文根据目前已有的国内外研究和报道,总结了泛素蛋白已知的磷酸化修饰位点,梳理了泛素蛋白第12位和66位苏氨酸、第57位和65位丝氨酸等位点的磷酸化修饰对其生物物理特性带来的改变,并对相应修饰位点所涉及的生物学功能调控进行了综述。  相似文献   
43.
(Zn·Cd)S:Ag-KI催化的光合磷酸化   总被引:3,自引:0,他引:3  
以半导体材料(Zn·Cd)S:Ag-KI为催化剂,在普通卤钨灯光照射下,成功地模拟了光合作用的光合磷酸化.文章报导了光强、照光时间、ADP浓度、Pi浓度及催化剂量等对ATP合成的影响.在合适的条件下,ADP浓度为1×10~(-3)mmolL时转化率可达到4-6°.最后有一简单讨论.  相似文献   
44.
研究了蜜蜂对相同颜色和不同颜色目标图对的形状以及颜色的综合识别能力实验过程中,蜜蜂始终处于自由飞行状态.做为刺激目标使用的图对分别有相同颜色不同几何形状、相同颜色不同拓扑结构和不同颜色几何形状三组.主要结果有三点:(1)在相同颜色的条件下,蜜蜂可以分辨出图形的几何形状,并且识别能力与图对的相似程度成反比(2)在刺激图形为环形时,蜜蜂对图形平均亮度敏感;在平均亮度相同的情况下,对环形细节变和尺寸大小不敏感.(3)在不同颜色不同几何形状的刺激条件下.蜜蜂视觉信息加工过程中颜色因素会抑制几何形状因素而起主要作用.这三个结果可以视为深入研究颜色加工通道和几何形状加工通道之间内在关系的基础.  相似文献   
45.
This work firstly reported a new polycaprolactone based material functionalized with guanidinium ionic liquid (PCL-GIL) as the stationary phase with high resolution performance for capillary gas chromatography (GC). It is composed of polycaprolactone (PCL) and guanidinium ionic liquid (GIL) with amphiphilic conformation. The PCL-GIL capillary column coated by static method exhibited high column efficiency of 3942 plates/m and moderate polarity. As a result, the PCL-GIL column exhibited high-resolution capability. For a mixture of 27 analytes with a wide ranging polarity and outperformed the PCL-2OH and HP-35 columns, showing its advantageous separation capability for analytes of diverse types. Moreover, the PCL-GIL column showed high resolving capability for various positional isomers and cis-/trans-isomers, including alkylbenzenes, chlorobenzenes, naphthalenes, bromonitrobenzenes, chloronitrobenzenes, benzaldehydes, phenols, alcohols, respectively. In a word, PCL derivatized by GIL units as a new type of stationary phase has a promising future in GC separations.  相似文献   
46.
陈鹏  宋佳  郭璞  冀瑞卿 《菌物学报》2023,42(1):297-311
蜜环菌属Armillaria真菌具有较高的食药用价值。由于蜜环菌的生长发育过程较复杂,还未完全实现商业化栽培,野生资源的供应受到季节性和地域性的影响。本研究以采自东北地区蜜环菌属的3个菌株为研究对象,通过培养物的形态特征及分子标记确定菌株JG19016为奥氏蜜环菌A. ostoyae,菌株JG19017为高卢蜜环菌A. gallica,菌株JG19018为中国蜜环菌生物种C。奥氏蜜环菌JG19016最适生长温度为25 ℃,高卢蜜环菌JG19017的最适生长温度为22 ℃,中国蜜环菌生物种C JG19018则在22-25 ℃时菌丝生长速度最快;3个菌株最适pH为5-6。奥氏蜜环菌JG19016对葡萄糖和蔗糖利用率较好,高卢蜜环菌JG19017对葡萄糖利用率较好,中国蜜环菌生物种C JG19018对葡萄糖和淀粉利用率较好;蛋白胨对3个菌株促进作用最强,为最适氮源。培养基中加入VB1,对3个菌株的菌丝生长均有明显的促进作用。奥氏蜜环菌JG19016菌丝生长的最优培养基配方为:葡萄糖20 g,蛋白胨3 g,磷酸二氢钾2 g,硫酸镁1.5 g,VB1 10 mg,琼脂20 g,水1 L。在木屑基质中培养,其配方的最优碳氮比为38:1,最佳木屑粗细比为3:1以上。出菇条件探索结果显示,菌丝及菌索长满菌袋(17 mm×33 mm×5 mm丝聚乙烯袋)需要50-60 d,之后在18 ℃、60%湿度和12 h散射光的环境中,10 d左右可观察到原基产生。增加菇房湿度到90%-95%,2-3 d可观察到1-3 cm的幼子实体,7 d左右菌柄和菌盖完全分化,10 d左右观察到菌盖展开。  相似文献   
47.
为探究燕麦(Avena sativa)-绿豆(Phaseolus radiatus)间作效应及氮素转移特性, 在不施氮肥的大田试验条件下, 设置3种种植模式(燕麦单作、绿豆单作和燕麦-绿豆间作), 采用传统挖根法和15N同位素标记法进行研究。结果表明, 间作系统中燕麦侵袭力强于绿豆, 绿豆生长受到抑制。整个生育期, 间作燕麦地上部干物质积累量比单作增加14.9%-33.1%, 2年成熟期间作燕麦的氮素积累量比单作分别提高53.1%和44.8%; 间作减少了开花结荚期绿豆氮素积累量和根瘤重量, 降低了绿豆的固氮效率, 绿豆的固氮效率2年平均降低23.7%, 生物固氮量平均减少11.66%。间作绿豆向燕麦的氮素转移率2年平均值达31.7%, 氮素转移量为212.16 kg∙hm-2。燕麦-绿豆间作降低了开花结荚期绿豆的根瘤固氮酶活性和固氮效率, 但绿豆体内氮素转移增加了燕麦对氮素的吸收利用, 实现了地上部与地下部生长的相互调节和促进, 优化了农田生态系统的氮素管理。  相似文献   
48.
The purpose of this paper is to systematically analyse the design and results of epidemiological studies on the association between various types of cancer (lung, bladder, breast, colon, stomach) and four genetically-based metabolic polymorphisms, involved in the metabolism of several carcinogens (glutathione-S-transferase M1, debrisoquine hydroxylase, N acetyltransferase, aryl hydrocarbon hydroxylase). These inherited polymorphisms usually cause modifications in the quality or quantity of the relevant enzymes. Such enzymes are involved in the activation/inactivation of known carcinogens and seem to modify the extent to which carcinogens interact with DNA in target tissues. Two enzymes, debrisoquine hydroxylase and aryl hydrocarbon hydroxylase, activate procarcinogens to carcinogens (phase I enzymes). The other two, glutathione-S-transferase M1 and N-acetyltransferase, mainly detoxity carcinogenic substances (phase II enzymes). Because of their role as host factors (modulating the action of carcinogens), it has been hypothesized that subjects presenting a specific phenotype for such polymorphisms could be at a greater risk of developing various types of cancer. A number of epidemiological studies have investigated such associations, often with discordant results. We examine and discuss the design of the studies, and present a meta-analysis of the available data.  相似文献   
49.
Restoration of cytoplasmic male sterility (CMS) in sunflower was demonstrated to be controlled by polygenes by analysing 982 effective crosses among 109 self-crossed lines and 16 CMS lines. Two self-crossed lines and one CMS line with distinct genotypes were applied to creation of segregating populations for DNA bulks of the target gene Rfl. Bulked DNA was prepared in order to investigate single gene Rfl and its gene marker among polygenic characters at the same genetic background. Using 80 10-mer operon primers, 620 RAPD reactions were carried out between fertile and sterile DNA bulks. In about 800 loci, primary results showed that 8 were related to the restoration genes. Furthermore. 2 were confirmed as RAPD markers for gene Rfl by examining 9 maintenance and 7 restoration lines. This method is the improvement for bulked segregant analysis[1] with which markers of single gene of target can be identified rapidly among polygenic characters.  相似文献   
50.
NAD激酶在光合作用等植物生理过程中起重要作用。NAD激酶的激活依赖于钙离子和钙调素(CalmOdulin,CaM).从植物中分离得到的一种新的CaM结合蛋白CaMBP-10(BP-10)明显抑制NAD激酶的激活活性,抑制作用可被CaM所克服.动力学研究表明,抑制效应是BP-10与CaM之间特异性相互作用的结果。实验证实BP-10对NAD激酶活性起着重要调节作用.  相似文献   
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