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991.
随着生物多样性信息学的迅速发展,越来越多开放的生物数据可供科研人员使用。以一个公开数据平台为例分析我国生物多样性领域的研究热点与发展趋势,有助于生物多样性工作者和决策者及时了解我国生物研究的现状及动向,为生物多样性建设提供决策支持。该文以“国家标本资源共享平台(NSII)”及相关词为检索对象,对中国知网和谷歌学术上2013—2023年间的文献进行全文检索,共检索出1 070篇NSII支撑的文献,包括期刊论文(822篇)、学位论文(233篇)、科普文章(5篇)、会议文章(6篇)和报道(4篇)。基于NSII支撑的822篇期刊论文,通过文献计量学的手段和方法,从发文情况、研究主题与热点、研究机构等方面探究NSII支撑的生物多样性研究现状、热点与态势。关键词共现网络图谱分析结果显示,基于数据平台的生物多样性研究热点集中在物种分布分析和建模、气候变化、分类学、生物多样性研究、研究平台建设五个方面。当前我国生物多样性信息学领域发展较快,未来仍需从数据源建设、资源整合、共享能力、业务能力和国际合作等方面努力提升,持续推动生物多样性科学研究的发展。  相似文献   
992.

Background

Subcellular localization of a new protein sequence is very important and fruitful for understanding its function. As the number of new genomes has dramatically increased over recent years, a reliable and efficient system to predict protein subcellular location is urgently needed.

Results

Esub8 was developed to predict protein subcellular localizations for eukaryotic proteins based on amino acid composition. In this research, the proteins are classified into the following eight groups: chloroplast, cytoplasm, extracellular, Golgi apparatus, lysosome, mitochondria, nucleus and peroxisome. We know subcellular localization is a typical classification problem; consequently, a one-against-one (1-v-1) multi-class support vector machine was introduced to construct the classifier. Unlike previous methods, ours considers the order information of protein sequences by a different method. Our method is tested in three subcellular localization predictions for prokaryotic proteins and four subcellular localization predictions for eukaryotic proteins on Reinhardt's dataset. The results are then compared to several other methods. The total prediction accuracies of two tests are both 100% by a self-consistency test, and are 92.9% and 84.14% by the jackknife test, respectively. Esub8 also provides excellent results: the total prediction accuracies are 100% by a self-consistency test and 87% by the jackknife test.

Conclusions

Our method represents a different approach for predicting protein subcellular localization and achieved a satisfactory result; furthermore, we believe Esub8 will be a useful tool for predicting protein subcellular localizations in eukaryotic organisms.
  相似文献   
993.
Phragmites communis Trin. (common reed) is a recognized model plant for studying its adaptation to contrasting and harsh environments. To understand the inherent molecular basis for its remarkable resistance to combined stresses, we performed a comprehensive proteomic analysis of the leaf proteins from two ecotypes, i.e. swamp and desert dune, naturally growing in the desert region of northwestern China. First, a proteome reference map of Phragmites was established based on the swamp ecotype. Proteins were resolved by 2‐D/SDS‐PAGE and identified by MALDI‐TOF/TOF MS. In total, 177 spots were identified corresponding to 51 proteins. The major proteins identified are proteins involved in photosynthesis, glutathione and ascorbic acid metabolism as well as protein synthesis and quality control. Second, the 2‐DE profiles of the two ecotypes were compared quantitatively via DIGE analysis. Compared with swamp ecotype, 51 proteins spots are higher‐expressed and 58 protein spots are lower‐expressed by twofold or more in desert dune ecotype. Major differences were found for the proteins involved in light reaction of photosynthesis, protein biosynthesis and quality control and antioxidative reactions. The physiological significance of such differences is discussed in the context of a flow of complex events in relation to plant adaptation to combined environmental stresses.  相似文献   
994.
Cytochrome P450 1B1 (CYP1B1) is a key P450 enzyme involved in the metabolism of exogenous and endogenous substrates in endocrine-mediated tumors such as prostate cancer. The potential significance of nonsynonymous SNP Leu432Val (rs1056836) as a risk factor in prostate cancer has been extensively studied. The objective of this meta-analysis was to quantitatively summarize the association between CYP1B1 Leu432Val polymorphism and prostate cancer. All eligible studies were searched and acquired from the PubMed and ISI databases. Statistical analysis was performed by using the software STATA 11.0. Ten case-controlled studies from nine eligible publications were identified, which includes 6,668 subjects with 3,221 cases and 3,447 controls. Overall, no significant association was found between the CYP1B1 Leu432Val polymorphism and prostate cancer susceptibility for Val/Val vs Leu/Leu (OR = 1.07; 95% CI: 0.79-1.44; P = 0.67), Leu/Val vs Leu/Leu (OR = 1.05; 95% CI: 0.94-1.17; P = 0.42), Leu/Val + Val/Val vs Leu/Leu (OR = 1.07; 95% CI: 0.91-1.26; P = 0.40) and Val/Val vs Leu/Val + Leu/Leu (OR = 1.11; 95% CI: 0.86-1.44; P = 0.43). However, a higher risk was found among Asians in all genetic models (Val/Val vs Leu/Leu :OR = 2.48, 95% CI: 1.14-5.39, P = 0.02; Leu/Val vs Leu/Leu: OR = 1.40, 95% CI: 1.03-1.89, P = 0.03; Leu/Val + Val/Val vs Leu/Leu: OR = 1.51, 95% CI = 1.14-2.01, P = 0.004; Val/Val vs Leu/Val + Leu/Leu: OR = 2.50, 95% CI = 1.35-4.56, P = 0.004). We were not able to detect any association in the subgroup analysis by source of controls and genotyping method in all genetic models. In conclusion, this meta-analysis provides evidence that CYP1B1 Leu432Val polymorphism is not associated with prostate cancer risk overall with the exception in Asians.  相似文献   
995.
996.
观察比较了粘虫核型多角体病毒(Pseudelatia separata NPV,PsNPV)、粘虫颗粒体病毒(Pseudelatia separata GV,PsGV)感染粘虫,以及两种病毒混合感染粘虫后,粘虫(Pseudelatia separata)前胸腺的形态特征和前胸腺细胞的超微结构。结果表明,不同感染组粘虫前胸腺腺体都有不同程度的组织病变,PsNPV感染组在感染晚期与前胸腺相连的气管严重病变,出现大量白色颗粒状物累积,被伊红染成紫黑色,腺体细胞被挤压变形;PsGV感染组的前胸腺腺体变小,单个细胞也小,细胞界限不十分明显;两种病毒混合感染组的腺体细胞小,能被伊红染色的细胞极少。同时,前胸腺细胞的超微结构也有不同程度的病变。  相似文献   
997.
百年来直接与昆虫学有关的诺贝尔奖得主   总被引:2,自引:1,他引:2  
胡萃  叶恭银 《昆虫知识》2001,38(5):388-392
本文介绍了 1 0名直接与昆虫学有关的诺贝尔奖得主的事迹 ,并简要讨论了百年诺贝尔奖历史带给人们的启示  相似文献   
998.
通过接种鸡胚成纤维细胞(CEF)、间接免疫荧光试验(IFA)和聚合酶链式反应(PCR),连续五年从全国各地的送检病料中分离到14株J亚群白血病病毒(ALV-J)。为了动态观察ALV-J囊膜表面结构蛋白(GP85)的变异情况,对这14株野毒株的囊膜糖蛋白基因(env)进行了克隆和测序,将它们与HPRS-103株的GP85的氨基酸序列进行了比较,结果表明:ALV-J的囊膜表面结构蛋白发生了很大的变异,而且这些变异主要集中在高变区hr1、hr2和vr3;这些野毒株GP85的氨基酸序列的同源性在86.6%~100%之间(从同一鸡场中分离到的两株ALV-J即BJ00302与BJ0303的同源性为100%,其它毒株之间的同源性均小于100%);有义突变与沉默突变的比例显示这3个高变区极有可能是免疫选择压作用的位点。  相似文献   
999.
Heterotrimeric G protein is involved in plant growth and development, while the role of rice (Oryza sativa) G protein γ subunit qPE9-1 in response to low-phosphorus (LP) conditions remains unclear. The gene expression of qPE9-1 was significantly induced in rice roots under LP conditions. Rice varieties carrying the qPE9-1 allele showed a stronger primary root response to LP than the varieties carrying the qpe9-1 allele (mutant of the qPE9-1 allele). Transgenic rice plants with the qPE9-1 allele had longer primary roots and higher P concentrations than those with the qpe9-1 allele under LP conditions. The plasma membrane (PM) H+-ATPase was important for the qPE9-1-mediated response to LP. Furthermore, OsGF14b, a 14-3-3 protein that acts as a key component in activating PM H+-ATPase for root elongation, is also involved in the qPE9-1 mediation. Moreover, the overexpression of OsGF14b in WYJ8 (carrying the qpe9-1 allele) partially increased primary root length under LP conditions. Experiments using R18 peptide (a 14-3-3 protein inhibitor) showed that qPE9-1 is important for primary root elongation and H+ efflux under LP conditions by involving the 14-3-3 protein. In addition, rhizosheath weight, total P content, and the rhizosheath soil Olsen-P concentration of qPE9-1 lines were higher than those of qpe9-1 lines under soil drying and LP conditions. These results suggest that the G protein γ subunit qPE9-1 in rice plants modulates root elongation for phosphorus uptake by involving the 14-3-3 protein OsGF14b and PM H+-ATPase, which is required for rice P use.  相似文献   
1000.
连作花生田根际土壤优势微生物的分离和鉴定   总被引:2,自引:0,他引:2  
【目的】从不同连作年限的花生田根际土壤中分离优势微生物并进行鉴定,为研究花生连作后优势微生物的变化奠定基础。【方法】采用土壤稀释分离法从不同连作年限花生根际土壤中分离优势细菌、真菌和放线菌,结合菌株形态特征、培养性状、生理生化特征及16S rDNA序列分析对细菌、放线菌进行鉴定,通过形态特征、培养特征和分子鉴定方法对优势真菌进行鉴定。【结果】从连作花生田根际土壤中分离鉴定出7种优势细菌、7种优势真菌和7种优势放线菌。7种优势细菌分别为Leifsonia xyli、氯酚节杆菌(Arthrobacterchlorophenolicus)、黄色微杆菌(Microbacterium flavescens)、鞘氨醇单胞菌属(Sphingomonas sp.)、巴斯德菌属(Pasteurella sp.)、简单芽孢杆菌(Bacillus simplex)和巨大芽孢杆菌(Bacillus megaterium)。7种优势真菌分别为枝状枝孢菌(Cladosporium cladosporioides)、产紫青霉(Penicillium purpurogenum)、哈茨木霉有性型(Hypocrea lixii)、Exophiala pisciphila、微紫青霉(Penicillium janthinellum)、曲霉(Aspergillus sp.)和大丽轮枝菌(Verticillium dahliae)。7种优势放线菌分别为紫红链霉菌(Streptomyces violaceoruber)、华丽黄链霉菌(Streptomyces flaveus)、Streptomyces panaciterrae、不产色链霉菌(Streptomyces achromogenes)、假浅灰链霉菌(Streptomyces pseudogriseolus)、纤维素链霉菌(Streptomyces cellulosae)和金色链霉菌(Streptomyces aureus)。【结论】本研究是第一次系统的从连作花生根际土中分离鉴定优势微生物,种植花生后根际土壤中优势微生物的种类发生了明显变化,但变化没有规律。  相似文献   
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