一类多分子反应模型的极限环的研究

本文研究了一类多分子反应模型：主要结果是：存在闭轨,当,Ρ/α-1＜a＜a时,(E)有传稳定的极限环,其中本文部分结果优于文〔2,3〕．     

具有常数收获率和第二类功能性反应的捕-食系统可以至少存在两个极限环

本文主要通过对细焦点的研究,得到了具常数收获率和Holling第二类功能性反应的捕食者──食饵系统可以至少存在两个极限环的条件,并对捕食者具常数收获率的情形,给出了闭轨线和奇异闭轨线不存在的条件．     

三种群合作系统的全局渐近性态

考虑三种群合作系统:dχi/dt=χi(b-∑j3=1αijχj),χi(0)>0,b>0,αij<0,i≠j,i,j=1,2,3,完整地分析了其全局渐近性态:证明了该系统不存在闭轨,给出了正平衡点存在且全局渐近稳定的充要条件,证明了若系统不存在正平衡点,则所有解均趋于无穷.     

烟夜蛾G蛋白αq亚基（HassGαq）的抗血清制备及在触角中的免疫定位

为了明确烟夜蛾Helicoverpa assulta G蛋白αq亚基（HassGαq）在雄性触角中的定位,进而探索该亚基在烟夜蛾嗅觉信号传导过程中的作用,本实验首先以原核表达的HassGαq蛋白作为抗原免疫Balb/c小鼠,制备了抗血清。SDS-PAGE分离雄性烟夜蛾触角匀浆上清液后,Western blot检测结果表明,所制备的抗血清可识别HassGαq蛋白,同时也与非目的蛋白发生反应,说明在雄性烟夜蛾触角中HassGαq基因可能有多个转录本,或者可能有多种G蛋白α亚基表达。此外,商品化的anti-G_q/11α抗血清可特异地识别HassGαq蛋白。因此,利用anti-G_q/11α抗血清和免疫组化方法对HassGαq蛋白在雄性烟夜蛾触角中进行定位,结果显示HassGαq在雄性烟夜蛾触角毛形感器和锥形感器的基部以及感器腔中皆有表达。据此推测HassGαq可能参与烟夜蛾的嗅觉信号传导。     

广义捕食系统无闭轨的几组充分条件

本文对一类广义捕食系统生物种群生态常微模型建立几组无闭轨的充分条件,为开拓涉及该类模型制作参考类作全局制图定性的研究．     

人多肽链延伸因子1α四个反转录假基因的鉴别与定位

人多肽链延伸因子1α基因EEF1A是一个在蛋白质合成过程中起重要作用的看家基因。通过对已有GenBank、GDB等数据库的综合分析,鉴别了4个人类多肽链延伸因子1α基因的反转录假基因,并分别将其精细定位于4q2 5、7p15-21、9q34和19q13上。 Abstract:The gene for human polypeptide chain elongation factor-1α(EEF1A)is a house-keeping gene which plays an important role in the process of protein synthesis.By means of comprehensive analysis in the database of Genbank,GDB and ect,we identify 4 retropseudogenes of EEF1A and finely localized to 4q25,7p15-21,9q34 and 19q13,respectively.     

血清5-HT、TNF-α、补体C1q对重性抑郁障碍急性期患者抗抑郁疗效的影响

摘要 目的：探讨血清5-羟色胺（5-HT）、肿瘤坏死因子-α（TNF-α）、补体C1q对重性抑郁障碍急性期患者抗抑郁疗效的影响。方法：选择2020年1月至2022年1月新疆精神卫生中心收治的185例首发重性抑郁障碍急性期患者,所有患者均接受抗抑郁药物治疗,根据疗效将患者分为无效组（32例）和有效组（153例）。治疗前、后检测血清5-HT、TNF-α、补体C1q水平,收集相关资料,多因素Logistic回归分析影响重性抑郁障碍急性期患者抗抑郁疗效的因素,受试者工作特征（ROC）曲线分析血清5-HT、TNF-α、补体C1q预测重性抑郁障碍急性期患者抗抑郁疗效的价值。结果：无效组治疗后血清5-HT、TNF-α、补体C1q与治疗前比较差异无统计学意义（P＞0.05）,有效组治疗后血清5-HT较治疗前增高（P＜0.05）,TNF-α、补体C1q较治疗前降低（P＜0.05）。无效组治疗后血清5-HT低于有效组,血清TNF-α、补体C1q高于有效组（P＜0.05）。多因素Logistic回归分析结果显示有自杀意念、高TNF-α、高补体C1q是重性抑郁障碍急性期患者抗抑郁治疗无效的危险因素,高5-HT是其保护因素（P＜0.05）。联合5-HT、TNF-α、补体C1q三项指标预测重性抑郁障碍急性期患者抗抑郁治疗无效的曲线下面积为0.828,高于单独指标预测的0.732、0.658、0.677。结论：重性抑郁障碍急性期抗抑郁治疗后无效患者血清5-HT偏低,TNF-α和补体C1q偏高,且与抗郁治疗无效有关,联合检测血清5-HT、TNF-α和补体C1q可预测抗抑郁疗效。     

IL-1β的促痫作用与GαmRNA表达的关系

目的为了探讨IL-1β的促痫作用机制.方法实验应用RT-PCR方法检测了谷氨酸钠致癫痫动物在同时脑内注射IL-1β、IL-1ra(IL-1R拮抗剂)或MCPG(mGluR5拮抗剂)后,海马组织Gαs、GαqmRNA的表达变化.结果 (1)谷氨酸钠诱导的癫痫发作使海马组织Gαs mRNA,Gαq mRNA表达上升.而IL-1β显著促进谷氨酸钠的作用,与单纯注射谷氨酸钠相比Gαs mRNA,Gαq mRNA表达上升更为显著(P＜0.05);(2)IL-1ra与MCPG均能阻断IL-1β的此种作用;(3)mGluR5 mRNA的表达未受影响.结论 IL-1β在癫痫中的作用是使Gαs,Gαq 激活,且表达上升,然后可能再通过cAMP等第二信使与其它受体或离子通道的相互作用起到促痫作用.mGluR5和 IL-1RⅠ在癫痫发作过程中可能存在协同作用,或者通过间接的"对话"共同促进Gαs和Gαq mRNA的表达,导致癫痫发作增强.     

密度制约的Holling Ⅲ型食饵与捕食者动力系统的定性分析

本文研究HollingⅢ型功能性反应的捕食系统得到平衡点的位置、个数、类型、闭轨线的不存在性和奇点稳定性的某些结论,测试算例表明,所得到的判定结论是有效的.     

一类食饵种群具有常数收获率的Kolmogolov系统的非线性分析

本文对一类食饵种群具有常数收获率的Ｋｏｌｍｏｇｏｌｏｖ系统进行了非线性分析,研究了 系统平衡点的性态,在较宽的条件下证明了系统不存在闭轨线;并获得了系统存在两个极限环的条件。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.