探讨模拟冷空气降温过程对健康大鼠和高血压大鼠凝血功能的影响

目的:通过模拟冷空气温度变化过程给予健康大鼠和高血压大鼠冷刺激,以此探讨冷空气过程对机体凝血功能的影响。方法:收集张掖市2011年3月一次典型冷空气过程数据,利用气象环境模拟箱模拟其温度变化过程。将24只雄性健康大鼠和24只雄性高血压大鼠分别随机分成最低温组(Tmin组)、Tmin对照组、复温组(Tr组)和Tr对照组。将Tmin组和Tr组大鼠放入气候箱中暴露冷空气温度变化过程。在Tmin和Tr时点分别停止Tmin组大鼠和Tr组大鼠冷空气暴露,并采血以测定其凝血功能指标—凝血四项。结果:与对照组相比,健康大鼠和高血压大鼠活化部分凝血酶原时间(APTT)、凝血酶原时间(PT)、凝血酶时间(TT)在降温后与对照组相比没有显著差异(P>0.05),但血浆纤维蛋白原(Fbg)含量在高血压大鼠和健康大鼠Tmin组明显高于其对照组(P<0.01)。温度恢复后,其在健康组含量仍然高于其对照组(P<0.05),而在高血压大鼠中没有差异(P>0.05)。同Fbg,反应Fbg的纤维蛋白原时间(Fbg-time)在健康大鼠Tmin和Tr组中短于对照组(P<0.01,),而在高血压大鼠中仅在Tmin组短于对照组(P<0.01)。高血压大鼠血中的Fbg含量和Fbgt明显高于和短于健康大鼠(P<0.01)。结论:①冷空气降温过程能增加机体血中Fbg含量,使凝血功能增强,可能增加心血管疾病危险性;②冷空气刺激对健康大鼠凝血功能影响强于高血压大鼠。     

Local habitat condition rather than geographic distance determines the genetic structure of Tamarix chinensis populations in Yellow River Delta,China

Tree Genetics &; Genomes - To breed a new variety of coffee (Coffea arabica) requires approximately 25&;nbsp;years due to the long generation time (5–6&;nbsp;years) of this perennial...     

沉默交配型信息调节因子2同源蛋白Sirt1

沉默交配型信息调节因子2同源蛋白1(silent mating type information regulation 2 homolog 1,Sirt1)是哺乳动物中与酵母沉默信息调节蛋白2(silencing information regulator 2,Sir2)高度同源的蛋白质,它是一种依赖NAD+的III类组蛋白去乙酰化酶(HDAC III),在细胞分化、衰老、凋亡、DNA损伤修复、能量及内分泌代谢调节中起重要作用,同时在基因沉默、表观遗传学修饰、转录调控及信号转导调节中发挥重要的生物学功能。本文对其近年的研究进展做一概述。     

中国棉铃虫核型多角体病毒DNA聚合酶基因的克隆和序列分析

应用谷实夜蛾核型多角体病毒（ＨｚＳＮＰＶ）ＤＮＡ聚合酶基因ＨｉｎｄⅢ／ＰｓｔⅠ３５９６ｂｐ片段作探针,经Ｓｏｕｒｔｈｅｒｎｂｌｏｔ杂交,克隆了中国棉铃虫核型多角体病毒（ＨａＳＮＰＶ）完整的ＤＮＡ聚合酶基因,大小约为３．４ｋｂ。限制性内切酶分析表明,ＨａＳＮＰＶＤＮＡ聚合酶基因限制性内切酶图谱与ＨｚＳＮＰＶ相似。用双脱氧链终止法测定该基因部分核苷酸序列（８０５ｂｐ）,推导出编码区２０６ａ。序列同源性比较显示,ＨａＳＮＰＶＤＮＡ聚合酶与ＨｚＳＮＰＶ之间具有高度的同源性;与ＬｄＭＮＰＶ、ＡｃＭＮＰＶ、ＢｍＳＮＰＶ、ＣｆＭＮＰＶ和ＯｐＭＮＰＶ也具有一定的同源性     

Discovery of new thienopyrimidine derivatives as potent and orally efficacious phosphoinositide 3-kinase inhibitors

A series of new thienopyrimidine derivatives has been discovered as potent PI3K inhibitors. The systematic SAR studies for these analogues are described. Among them, 8a and 9a exhibit nanomolar enzymatic potencies and sub-micromolar cellular anti-proliferative activities. 8a displays favorable pharmacokinetic profiles, while 9a easily undergoes deacetylation to yield a major metabolite 8a. Furthermore, 8a and 9a potently inhibit tumor growth in a dose-dependent manner in the NCI-H460 xenograft model with an acceptable safety profile.     

Iron metabolism in diabetes-induced Alzheimer’s disease: a focus on insulin resistance in the brain

Alzheimer’s disease (AD) is characterized by an excessive accumulation of toxic amyloid beta (Aβ) plaques and memory dysfunction. The onset of AD is influenced by age, genetic background, and impaired glucose metabolism in the brain. Several studies have demonstrated that diabetes involving insulin resistance and glucose tolerance could lead to AD, ultimately resulting in cognitive dysfunction. Even though the relationship between diabetes and AD was indicated by significant evidences, the critical mechanisms and metabolic alterations in diabetes induced AD are not clear until now. Recently, iron metabolism has been shown to play multiple roles in the central nervous system (CNS). Iron deficiency and overload are associated with neurodegenerative diseases. Iron binds to Aβ and subsequently regulates Aβ toxicity in the CNS. In addition, previous studies have shown that iron is involved in the aggravation of insulin resistance. Considering these effects of iron metabolism in CNS, we expect that iron metabolism may play crucial roles in diabetic AD brain. Thus, we review the recent evidence regarding the relationship between diabetes-induced AD and iron metabolism.     

Clonal crayfish as biological model: a review on marbled crayfish

Since the mid-twentieth century, numerous vertebrates and invertebrates have been used as model organisms and become indispensable tools for exploring a broad range of biological and ecological processes. Crayfish seem to be adequate models which resulted in their involvement in research. In the two decades since its discovery, ongoing research has confirmed that the marbled crayfish (Procambarus virginalis Lyko, 2017) is an ideal taxon in this regard, especially due to its almost continuous asexual reproduction providing a source of genetically identical offspring. This review provides an overview of the occurrence, biology, ecology, ethology, and human exploitation of marbled crayfish with primary focus on its use as a laboratory model organism as well as potential risks to native biota in case of its introduction. Genetic uniformity, ease of culture, and a broad behaviour repertoire fosters the use of marbled crayfish in epigenetics and developmental biology, as well as physiological, ecotoxicological, and ethological research. Marbled crayfish could be further exploited for basic and applied fields of science such as evolutionary biology and clonal tumour evolution. However, due to its high invasive potential in freshwater environments security measures must be taken to prevent its escape into the wild.     

Duplication and adaptive evolution of the chalcone synthase genes of Dendranthema (Asteraceae)

Chalcone synthase (CHS) is a key enzyme in the biosynthesis of flavonoids, which are important for the pigmentation of flowers and act as attractants to the pollinators. Genes encoding CHS constitute a multigene family in which the copy number varies among plant species and functional divergence appears to have occurred repeatedly. Plants of the Dendranthema genus have white, yellow, and pink flowers, exhibiting considerable variation in flower color. In this article, 18 CHS genes from six Dendranthema species were sequenced. Two of them were found to be pseudogenes. The functional Dendranthema CHS genes formed three well-supported subfamilies: SF1, SF2, and SF3. The inferred phylogeny of the CHS genes of Dendranthema and Gerbera suggests that those genes originated as a result of duplications before divergence of these two genera, and the function of Dendranthema CHS genes have diverged in a similar fashion to the Gerbera CHS genes; i.e., the genes of SF1 and SF3 code for typical CHS enzymes expressed during different stages of development, whereas the genes of SF2 code for another enzyme that is different from CHS in substrate specificity and reaction. Relative rate tests revealed that the Dendranthema CHS genes significantly deviated from clocklike evolution at nonsynonymous sites. Maximum likelihood analysis showed that the nonsynonymous-synonymous (omega = d(N)/d(S)) rate ratio for the lineage ancestral to SF2 was much higher than for other lineages, with some sites having a ratio well above one. Positive selective pressure appears to have driven the divergence of SF2 from SF1 and SF3.     

Beta-ionone is a functional plant volatile that attracts the parasitic wasp,Microplitis pallidipes

BioControl - The effects of plant volatiles on parasitoids are important with regards to the tri-trophic interactions among host plants, insect herbivores, and their natural enemies. However, the...