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871.
M?Cecilia?JohnsonEmail author Marisa?Torres Alessandra?Alves Ketty?Bacallao Ariel?Fuentes Margarita?Vega M?Angélica?Boric 《Reproductive biology and endocrinology : RB&E》2005,3(1):45
Background
Endometriosis is a common gynaecological disorder characterized by the presence of endometrial tissue outside of the uterus. The fragments in normal menstruation are composed of necrotic and living cells, which do not survive in ectopic locations because of programmed cell death. The aim of this study was to evaluate if the balance between cell proliferation and apoptosis is changed in eutopic endometrium from women with endometriosis throughout the menstrual cycle by studying bax (pro-apoptotic), c-myc (regulator of cell cycle) and TGF-beta1 (involved in cell differentiation) genes. 相似文献872.
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874.
Tropical Soil Bacterial Communities in Malaysia: pH Dominates in the Equatorial Tropics Too 总被引:2,自引:0,他引:2
Tripathi BM Kim M Singh D Lee-Cruz L Lai-Hoe A Ainuddin AN Go R Rahim RA Husni MH Chun J Adams JM 《Microbial ecology》2012,64(2):474-484
The dominant factors controlling soil bacterial community variation within the tropics are poorly known. We sampled soils across a range of land use types--primary (unlogged) and logged forests and crop and pasture lands in Malaysia. PCR-amplified soil DNA for the bacterial 16S rRNA gene targeting the V1-V3 region was pyrosequenced using the 454 Roche machine. We found that land use in itself has a weak but significant effect on the bacterial community composition. However, bacterial community composition and diversity was strongly correlated with soil properties, especially soil pH, total carbon, and C/N ratio. Soil pH was the best predictor of bacterial community composition and diversity across the various land use types, with the highest diversity close to neutral pH values. In addition, variation in phylogenetic structure of dominant lineages (Alphaproteobacteria, Beta/Gammaproteobacteria, Acidobacteria, and Actinobacteria) is also significantly correlated with soil pH. Together, these results confirm the importance of soil pH in structuring soil bacterial communities in Southeast Asia. Our results also suggest that unlike the general diversity pattern found for larger organisms, primary tropical forest is no richer in operational taxonomic units of soil bacteria than logged forest, and agricultural land (crop and pasture) is actually richer than primary forest, partly due to selection of more fertile soils that have higher pH for agriculture and the effects of soil liming raising pH. 相似文献
875.
Lee DF Su J Ang YS Carvajal-Vergara X Mulero-Navarro S Pereira CF Gingold J Wang HL Zhao R Sevilla A Darr H Williamson AJ Chang B Niu X Aguilo F Flores ER Sher YP Hung MC Whetton AD Gelb BD Moore KA Snoeck HW Ma'ayan A Schaniel C Lemischka IR 《Cell Stem Cell》2012,11(2):179-194
Many signals must be integrated to maintain self-renewal and pluripotency in embryonic stem cells (ESCs) and to enable induced pluripotent stem cell (iPSC) reprogramming. However, the exact molecular regulatory mechanisms remain elusive. To unravel the essential internal and external signals required for sustaining the ESC state, we conducted a short hairpin (sh) RNA screen of 104 ESC-associated phosphoregulators. Depletion of one such molecule, aurora kinase A?(Aurka), resulted in compromised self-renewal and consequent differentiation. By integrating global gene expression and computational analyses, we discovered that loss of Aurka leads to upregulated p53 activity?that triggers ESC differentiation. Specifically, Aurka regulates pluripotency through phosphorylation-mediated inhibition of p53-directed ectodermal and mesodermal gene expression. Phosphorylation of p53 not only impairs p53-induced ESC differentiation but also p53-mediated suppression of iPSC reprogramming. Our studies demonstrate an essential role for Aurka-p53 signaling in the regulation of self-renewal, differentiation, and somatic cell reprogramming. 相似文献
876.
Young-Jung?Wee Jong-Sun?Yun Don-Hee?Park Hwa-Won?RyuEmail author 《Biotechnology and Bioprocess Engineering》2004,9(4):303-308
We isolated a novel lactic acid bacterium from a Korean traditional fermented food, soybean paste. The newly isolated strain,
dubbed RKY2, grew well on glucose, sucrose, galactose, and fructose, but it could not utilize xylose, starch, or glycerol.
When the partially amplified 16S rDNA sequence (772 bp) of the strain RKY2 was compared with 10 reference strains, it was
found to be most similar toLactobacillus pentosus JCM 1588T, with 99.74% similarity. Therefore, the strain RKY2 was renamedLactobacillus sp. RKY2, which has been deposited in the Korean Collection for Type Cultures as KCTC 10353BP.Lactobacillus sp. RKY2 was found to be a homofermentative lactic acid bacterium, because its end-product from glucose metabolism was found
to be mainly lactic acid. It could produce more than 90 g/L of lactic acid from MRS medium supplemented with 100 g/L of glucose,
with 5.2 g L−1 h−1 of productivity and 0.95 g/g of lactic acid yield. 相似文献
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濒危植物独花兰的形态变异及其适应意义 总被引:14,自引:1,他引:14
采用ANOVA和UPGMA等方法对濒危植物独花兰(Changnieniaamoena)分布于庐山、新宁和神农架3个地点的12个自然居群的形态变异进行了研究,探讨其形态多样性水平和地理变异式样及其可能的适应机制。结果表明,庐山居群13个性状的平均观测值均高于新宁和神农架居群。在物种水平上各个性状存在较丰富的变异,变异系数(CV值)为0.02–0.30。尽管同一性状在不同居群中的变异程度较大,但总体而言,花部器官的变异性比营养器官低。单因素方差分析显示3个地区间多个形态性状存在极显著差异(P<0.01);UPGMA聚类分析也表明这3个地区分别形成明显不同的分支。值得注意的是,神农架地区龙门河和关门山两个地点间存在明显的形态分化,而这种形态分化是以传粉者为媒介自然选择的结果。相关性分析显示,营养器官之间、花部器官之间,以及营养器官与花部器官之间均存在较高的相关性。上述结果对进一步了解独花兰的适应机制以及制定科学的保护策略提供了有益的资料。 相似文献
880.
Brandon A. Chan Sunting Xuan Ang Li Jessica M. Simpson Garrett L. Sternhagen Tianyi Yu Omead A. Darvish Naisheng Jiang Donghui Zhang 《Biopolymers》2018,109(1)
Polypeptoids, a class of peptidomimetic polymers, have emerged at the forefront of macromolecular and supramolecular science and engineering as the technological relevance of these polymers continues to be demonstrated. The chemical and structural diversity of polypeptoids have enabled access to and adjustment of a variety of physicochemical and biological properties (eg, solubility, charge characteristics, chain conformation, HLB, thermal processability, degradability, cytotoxicity and immunogenicity). These attributes have made this synthetic polymer platform a potential candidate for various biomedical and biotechnological applications. This review will provide an overview of recent development in synthetic methods to access polypeptoid polymers with well‐defined structures and highlight some of the fundamental physicochemical and biological properties of polypeptoids that are pertinent to the future development of functional materials based on polypeptoids. 相似文献