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51.
Xie J  Zhang L  Ye Q  Zhou Q  Xin L  Du P  Gan R 《Biotechnology letters》2003,25(2):173-177
A recombinant strain of Pichia pastoris with a phenotype of MutS was used to produce angiostatin. Due to the low methanol consumption rate of this strain, both methanol and glycerol feedings, that produced oscillation in dissolved O2 concentration, were used during the expression phase to improve cell growth and angiostatin expression. However, enhanced cell growth led to nitrogen limitation that suppressed further production of angiostatin, but addition of ammonia allowed angiostatin concentration to reach 108 mg l–1 after an expression period of 96 h. The ratio of consumed glycerol to methanol of 1.5:1 (w/w) in the expression phase suggested that methanol played an important role in the metabolism of carbon sources.  相似文献   
52.
During the central nervous system (CNS) development, radial glia cells (RGCs) play at least two essential roles, they contribute to neuronal production and the subsequent guidance of neuronal migration, whereas its precise distribution and contribution to cerebral cortex remains less understood. In this research, we used Vimentin as an astroglial marker and Sox2 as a neural progenitor marker to identify and investigate RGCs in rat cerebral cortex at embryonic day (E) 16.5. We found that the Sox2+ progenitor cells localized in the germinal zone (GZ) of E16.5 cerebral cortex, ~95% Sox2+ cells co-localized with Vimentin+ or Nestin+ radial processes which extended to the pial surface across the cortical plate (CP). In vitro, we obtained RG-like cells from E16.5 cerebral cortex on adherent conditions, these Sox2+ Radial glia (RG)-like cells shared some properties with RGCs in vivo, and these Sox2+ RG-like cells could differentiate into astrocytes, oligodendrocytes and presented the radial glia—neuron lineage differentiation ability. Taken together, we identified and investigated some characterizations and properties of Sox2+ RGCs derived from E16.5 cerebral cortex, we suggested that the embryonic Sox2+ progenitor cells which located in the cortical GZ were mainly composed of Sox2+ RGCs, and the cortex-derived Sox2+ RG-like cells displayed the radial glia—neuron lineage differentiation ability as neuronal progenitors in vitro.  相似文献   
53.
A novel cDNA clone encoding a COR413-like gene was isolated by suppression subtraction hybridization and cDNA library screening from sea-island cotton (Gossypium barbadense). This gene (designated as GbCOR413, Accession number: AY761065) has a total length of 893 bp with an open reading frame of 600 bp, encoding a predicated polypeptide of 200 amino acids with a molecular weight of 22.74 kDa and a predicated pI of 9.2. Bioinformatics analyses revealed that this gene belonged to a novel stress-regulated multi-spanning transmembrane protein family without signal peptide. By means of semi-quantities RT-PCR analysis, the expression of GbCOR413 under short-term cold treatment at 4°C, water submergence and abscic acid treatment was investigated. Our studies suggested that the cloned gene was a new member of COR gene family which was slowly responsive to cold stress in cotton. Jin Wang and Kai-Jing Zuo are co-first authors of this paper.  相似文献   
54.

Purpose

To conduct a systematic review of included studies assessing the association of GP210 and SP100 with the risk of primary biliary cirrhosis (PBC) using meta-analysis.

Methods

Five databases, the Cochrane Library, MEDLINE, VIP, CNKI, WANFANG were used to detect the role of GP210 and SP100 in diagnosis of PBC. Approximately 13,000 participants from several countries were included in this analysis. Meta-DiSc statistical software was used for analysis.

Results

25 studies on GP210 and 21 studies on SP100 were included in the meta-analysis. The DOR, sensitivity, specificity of GP210 in diagnosis of PBC were 24.854 (11.957–51.660), 0.272 (0.257–0.288), 0.985 (0.982–0.988), respectively, and they were 9.133 (4.739–17.600), 0.231 (0.213–0.249), 0.977 (0.973–0.981) for SP100.

Conclusion

Our meta-analysis indicated both GP210 and SP100 had high specificity but low sensitivity in diagnosis of PBC.  相似文献   
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Vitex negundo L. var. heterophylla (Franch.) Rehder (Lamiaceae) is an important tree species for soil and water conservation, yet the reproductive ecology of this species remains to be elucidated. To investigate the reproductive traits of V. negundo var. heterophylla, the phenology, morphological characteristics (a suite of characters was assessed: floral morphology, nectar production, pollen viability, and stigma receptivity) and mating system of this species were systematically revealed for the first time in this study. Phenological observations, morphological measurements, and nectar production analysis were conducted during anthesis. Pollen viability and stigma receptivity at different flowering stages were measured by biochemical methods. Finally, genetic analysis based on SSR markers was used to reveal the mating system; outcrossing index and pollen‐ovule ratio were also calculated to help analysis. V. negundo var. heterophylla showed several obvious characteristics of outcrossing, such as abundant and attractive flowers, secreting nectar, and emitting scent. In addition, mechanisms such as homogamy and a short anther‐stigma distance that can promote self‐fertilization were also identified in this species. The coexistence of selfing and outcrossing characteristics demonstrates a predominantly outcrossed mixed mating system (outcrossing rate, t = 95%). The scientific information provided by this study may contribute to conservation of V. negundo var. heterophylla from a reproductive perspective.  相似文献   
58.
Central nervous system (CNS) maintains a high level of metabolism, which leads to the generation of large amounts of free radicals, and it is also one of the most vulnerable organs to oxidative stress. Emerging evidences have shown that, as the key homeostatic cells in CNS, astrocytes are deeply involved in multiple aspects of CNS function including oxidative stress regulation. Besides, the redox level in CNS can in turn affect astrocytes in morphology and function. The complex and multiple roles of astrocytes indicate that their correct performance is crucial for the normal functioning of the CNS, and its dysfunction may result in the occurrence and progression of various neurological disorders. To date, the influence of astrocytes in CNS oxidative stress is rarely reviewed. Therefore, in this review we sum up the roles of astrocytes in redox regulation and the corresponding mechanisms under both normal and different pathological conditions.  相似文献   
59.
Microsatellites are widely distributed throughout nearly all genomes which have been extensively exploited as powerful genetic markers for diverse applications due to their high polymorphisms. Their length variations are involved in gene regulation and implicated in numerous genetic diseases even in cancers. Although much effort has been devoted in microsatellite database construction, the existing microsatellite databases still had some drawbacks, such as limited number of species, unfriendly export format, missing marker development, lack of compound microsatellites and absence of gene annotation, which seriously restricted researchers to perform downstream analysis. In order to overcome the above limitations, we developed PSMD (Pan‐Species Microsatellite Database, http://big.cdu.edu.cn/psmd/ ) as a web‐based database to facilitate researchers to easily identify microsatellites, exploit reliable molecular markers and compare microsatellite distribution pattern on genome‐wide scale. In current release, PSMD comprises 678,106,741 perfect microsatellites and 43,848,943 compound microsatellites from 18,408 organisms, which covered almost all species with available genomic data. In addition to interactive browse interface, PSMD also offers a flexible filter function for users to quickly gain desired microsatellites from large data sets. PSMD allows users to export GFF3 formatted file and CSV formatted statistical file for downstream analysis. We also implemented an online tool for analysing occurrence of microsatellites with user‐defined parameters. Furthermore, Primer3 was embedded to help users to design high‐quality primers with customizable settings. To our knowledge, PSMD is the most extensive resource which is likely to be adopted by scientists engaged in biological, medical, environmental and agricultural research.  相似文献   
60.
Advances in high-throughput sequencing(HTS)have fostered rapid developments in the field of microbiome research,and massive microbiome datasets are now being generated.However,the diversity of software tools and the complexity of analysis pipelines make it difficult to access this field.Here,we systematically summarize the advantages and limitations of micro-biome methods.Then,we recommend specific pipelines for amplicon and metagenomic analyses,and describe commonly-used software and databases,to help researchers select the appropriate tools.Furthermore,we introduce statistical and visualization methods suit-able for microbiome analysis,including alpha-and beta-diversity,taxonomic composition,difference compar-isons,correlation,networks,machine learning,evolu-tion,source tracing,and common visualization styles to help researchers make informed choices.Finally,a step-by-step reproducible analysis guide is introduced.We hope this review will allow researchers to carry out data analysis more effectively and to quickly select the appropriate tools in order to efficiently mine the bio-logical significance behind the data.  相似文献   
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