锗对水稻萌芽期的生理效应

将水稻(Oryza sativa L．)种子浸于从0到3 mg• L-1不同浓度梯度的GeO2溶液中,测量其生理指标：呼吸强度,可溶性糖含量,淀粉酶活性等。发现在浸种的前期,GeO2对以上各项生理指标均有促进作用,而随着浸种时间的延长,促进逐渐减弱并转为抑制,淀粉酶同功酶电泳则表明,植物体内复杂多样的同功酶系统在一定范围内对GeO2的毒害作用有某种程度的适应与调节能力。     

水稻幼苗冷锻炼过程中钙的效应

冷锻炼处理提高了水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）幼苗叶片中抗氧化剂（还原型谷胱甘肽,ＧＳＨ;抗坏血酸,ＡｓＡ）含量和膜保护酶（超氧化物歧化酶,ＳＯＤ）的活性,同时也提高了可溶性蛋白质中热稳定蛋白的含量。ＣａＣｌ２ 浸种处理对上述冷锻炼的作用有加强的效果,且明显地提高了过氧化氢酶（ＣＡＴ）和过氧化物酶（ＰＯＤ）的活性。有无ＣａＣｌ２ 处理的冷锻炼处理均减轻冷胁迫引起的ＧＳＨ 及ＡｓＡ 含量、ＳＯＤ 活性及热稳定蛋白质含量的下降程度,有利于幼苗在恢复过程中ＧＳＨ、ＡｓＡ、ＣＡＴ、ＳＯＤ、ＰＯＤ及热稳定蛋白质水平迅速回升。结合ＣａＣｌ２ 处理的冷锻炼苗在冷胁迫恢复生长时增长迅速,且苗健壮浓绿,说明ＣａＣｌ２浸种对冷锻炼处理提高水稻幼苗的抗冷力有明显的促进作用,这与ＣａＣｌ２ 浸种结合冷锻炼能更有效的提高细胞膜保护能力有关     

葡萄糖淀粉酶研究进展

葡萄糖淀粉酶研究进展杨依军,李多川,沈崇尧（北京农业大学植物科技学院．北京１０００９４）葡萄糖淀粉酶（ＧｌｕｃｏａｍｖｌａｓｅＥ·Ｃ３．２．１．３）,又称淀粉葡萄糖苷酶（Ａｍｙｌｏｇｌｕｃｏｓｉｄａｓｅ）或γ－淀粉酶（γ－ａｍｙｌａｓｅ）,简称糖化酶...     

玉米素对叶绿体耦联因子Mg~（2＋）－ATPase活力的调节

用２μｇ／ｍｌ玉米素溶液预处理叶绿体或在光活化前于活化液中加入２μｇ／ｍｌ玉米素溶液,观察到玉米素能促进叶绿体膜上耦联因子ＤＴＴ光活化Ｍｇ２＋－ＡＴＰａｓｅ及Ｍｇ２＋ＧＴＰａｓｅ的活力．且对ＧＴＰａｓｅ的促进比例常较ＡＴＰａｓｅ的大些。王米素对ＯＧ活化可溶性ＣＦ１Ｍｇ２＋－ＡＴＰａｓｅ活力同样表现出促进作用。用玉米素预处理ＣＦ１－β亚基（含微量ＣＦ１－α亚基）也观察到它能促进ＣＦ１－β亚基催化的Ｍｇ２＋－ＡＴＰａｓｅ活力。这些结果表明,玉米素在ＣＦ１上的作用部位至少有一个在β亚基或α．β亚基交界处调节其催化功能的。     

玉米素对叶绿体耦联因子Mg^2＋—ATPase活力的调节

用２μｇ／ｍｌ玉米素溶液预处理叶绿体或在光活化前于活化液中加入２μｇ／ｍｌ玉米素溶液,观察到玉米素能促进叶绿体膜上耦联因子ＤＴＴ光活化Ｍｇ＾２＋－ＡＴＰａｓｅ及Ｍｇ＾２＋－ＧＴＰａｓｅ的活力,且对ＧＴＰａｓｅ的促进比例常较ＡＴＰａｓｅ的大些。玉米素对ＯＧ活化可溶性ＣＦ１Ｍｇ＾２＋－ＡＴＰａｓｅ活力同样表现出促进作用。用玉米素预处理ＣＦ１－β亚基（含微量ＣＦ１－α亚基）也观察到它促进ＣＦ１－β亚基催     

钙对水稻幼苗抗冷性的影响

ＣａＣｌ２浸种提高水稻幼苗叶片中结合态钙、内源抗氧化剂（ＧＳＨ、ＡｓＡ）含量和膜保护酶（ＣＡＴ、ＳＯＤ和ＰＯＤ）活性,也增加可溶性蛋白质中煮沸稳定蛋白质（ｂｏｉｌｉｎｇ－ｓｔａｂｌｅｐｒｏｔｅｉｎ）的含量。冷胁迫期间,ＣａＣｌ２并能减少因冷胁迫引起的ＧＳＨ、ＡｓＡ含量,ＣＡＴ、ＳＯＤ和ＰＯＤ活性以及煮沸稳定蛋白质下降的程度。在恢复期间,经ＣａＣｌ２处理的幼苗其ＧＳＨ、ＡＳＡ、ＣＡＴ、ＳＯＤ和ＰＯＤ以及煮沸稳定蛋白质水平均有回升。     

PAGE活性染色法分析D.radiodurans过氧化氢酶和起氧化物歧化酶

用ＰＡＧＥＡ活性染色分析了Ｄ．ｒａｄｉｏｄｕｒａｎｓ过氧化氢酶（Ｃａｔ）和起氧化物歧化酶（ＳＯＤ）。２种同种异型Ｄ．ｒａｄｉｏｄｕｒａｎｓ（Ｒ１和Ｓａｒｋ）的Ｃａｔ在电泳带型上存在差异,两者Ｋａｔ均可分为Ａ、Ｂ和Ｃ３条带,但各带所占比例明显不同,ＳＯＤ的分析结果表明,Ｄ．ｒａｄｉｏｄｕｒａｎｓ ＳＯＤ以Ｆｅ＾２＋和Ｍｎ＾２＋离子的嵌合体形式存在,其中Ｆｅ－ＳＯＤ成分占９０％以上。ＰＡＧＥ活性染色法     

活性氧与蛋白多糖的作用及损伤的蛋白多糖对矿化过…

本文用凝胶色谱和琼脂糖－聚丙烯酰胺混俣凝胶电泳法比较地研究了活性氧和病区黄腐酸对氨基多糖和蛋白多糖作用,并用恒ｐＨ值法研究了完整和受损的ＰＧ对矿化的影响。结果表明：１,黄嘌呤－黄嘌呤氧化酶体系对ＧＡＧ无明显降解作用,只损伤ＰＧ的核心蛋白。２,Ｆｅ（Ⅱ）－ＥＤＴＡ－Ｈ２Ｏ２体系同进损伤ＰＧ和ＧＡＧ,并与Ｈ２Ｏ２浓度和作用时间正相关。３,ＦＡ不能直接降解ＧＡＧ和ＰＧ。４,ＰＧ能推延磷酸钙成核的诱导期,     

箬叶多糖及其化学修饰物、亚硒酸钠和GSH对Cu~(2+)诱导的LDL氧化修饰的保护作用

研究了箬叶多糖ＦⅢ－ａ及其化学修饰物、亚硒酸钠和ＧＳＨ对Ｃｕ２＋诱导的低密度脂蛋白氧化修饰的保护作用．其结果表明箬叶多糖、硫酸酯多糖、硒酸酯多糖可显著抑制脂质过氧化产物（ＴＢＡＲＳ）及荧光物质的生成,彼此之间无明显差异．但对ＶＥ的消耗有着不同的保护作用,其顺序是ＦⅢ－ａ＞Ｓ－ＦⅢ－ａ＞Ｓｅ－ＦⅢ－ａ,并且具有明显的量效关系．硒或ＧＳＨ对Ｃｕ２＋诱导的ＬＤＬ氧化修饰无明显的抑制,但联合使用在０．１２５ｍｍｏｌ／ＬＮａ２ＳｅＯ３和０．２ｍｍｏｌ／ＬＧＳＨ及１２．５μｍｏｌ／ＬＮａ２ＳｅＯ３和０．０２ｍｍｏｌ／ＬＧＳＨ的浓度下能强烈地抑制ＴＢＡＲＳ的生成,甚至比正常的ＬＤＬ还要低．但是对ＶＥ的消耗只有较弱的保护作用,硒酸酯多糖与此相似．Ｎａ２ＳｅＯ３在０．１２５ｍｍｏｌ／Ｌ时可以明显抑制荧光物质的生成．     

莲子超氧物歧化酶的特性分析

比较了莲子、豇豆、绿豆、玉米、花生、菜心等种植物种子的胚或胚轴超的歧化酶９ＳＯＤ）的活性和热稳定性,其中莲子胚轴中ＳＯＤ活性及耐热性最高。莲子胚轴粗提液中的ＳＯＤ有Ｍｎ￣ＳＯＤ和Ｆｅ－ＳＯＤ两种类型,而Ｆｅ－ＳＯＤ耐高温。经１００℃处理、硫酸铵沉淀、Ｓｅｐｈａｄｅｘ Ｇ－１００凝胶过滤和ＤＥＡＥ－纤维素柱层析,获得纯化的耐热性强的超氧物歧化酶,纯化酶对ＰＣＮ不敏感,活性受Ｈ２Ｏ２抑制,属于Ｆｅ－Ｓ     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).