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排序方式: 共有416条查询结果,搜索用时 15 毫秒
371.
372.
Francesca Turroni Christian Milani Sabrina Duranti Chiara Ferrario Gabriele Andrea Lugli Leonardo Mancabelli Douwe van Sinderen Marco Ventura 《Cellular and molecular life sciences : CMLS》2018,75(1):103-118
Throughout the human life, the gut microbiota interacts with us in a number of different ways, thereby influencing our health status. The acquisition of such an interactive gut microbiota commences at birth. Medical and environmental factors including diet, antibiotic exposure and mode of delivery are major factors that shape the composition of the microbial communities in the infant gut. Among the most abundant members of the infant microbiota are species belonging to the Bifidobacterium genus, which are believed to confer beneficial effects upon their host. Bifidobacteria may be acquired directly from the mother by vertical transmission and their persistence in the infant gut is associated with their saccharolytic activity toward glycans that are abundant in the infant gut. Here, we discuss the establishment of the infant gut microbiota and the contribution of bifidobacteria to this early life microbial consortium. 相似文献
373.
Hennies HC Kornak U Zhang H Egerer J Zhang X Seifert W Kühnisch J Budde B Nätebus M Brancati F Wilcox WR Müller D Kaplan PB Rajab A Zampino G Fodale V Dallapiccola B Newman W Metcalfe K Clayton-Smith J Tassabehji M Steinmann B Barr FA Nürnberg P Wieacker P Mundlos S 《Nature genetics》2008,40(12):1410-1412
Gerodermia osteodysplastica is an autosomal recessive disorder characterized by wrinkly skin and osteoporosis. Here we demonstrate that gerodermia osteodysplastica is caused by loss-of-function mutations in SCYL1BP1, which is highly expressed in skin and osteoblasts. The protein localizes to the Golgi apparatus and interacts with Rab6, identifying SCYL1BP1 as a golgin. These results associate abnormalities of the secretory pathway with age-related changes in connective tissues. 相似文献
374.
以纤维二糖特异诱导培养里氏木霉和黑曲霉菌丝,制备含有细胞外、细胞内和细胞质膜结合态β葡萄糖苷酶的无细胞抽提物,采用色谱持谱联用分析,比较研究他们对纤维二糖的转糖基作用,结果表明两菌株中都只有细胞质膜结合态β葡萄糖苷酶表现出显著的转糖基活性,可检测到的含有β糖苷键葡二糖类的主要转糖基产物是β龙胆二糖而不是槐糖.当在里氏木霉和黑曲霉菌丝的洗脱置换培养体系中加入β龙胆二糖时,可以诱导纤维素酶合成,但它比槐糖(迄今最有潜力的诱导物)的诱导效率低.这些结果支持假说认为是质膜结合态β葡萄糖苷酶从纤维素寡聚物形成转糖基作用产物,作为纤维素酶合成的诱导物 相似文献
375.
Consequences of a biological invasion reveal the importance of mutualism for plant communities. 总被引:22,自引:0,他引:22
C E Christian 《Nature》2001,413(6856):635-639
Seed-dispersal mutualisms have a fundamental role in regenerating natural communities. Interest in the importance of seed dispersal to plant communities has been heightened by worldwide declines in animal dispersers. One view, the 'keystone mutualist hypothesis', predicts that these human-caused losses will trigger a cascade of linked extinctions throughout the community. Implicitly, this view holds that mutualisms, such as seed dispersal, are crucial ecological interactions that maintain the structure and diversity of natural communities. Although many studies suggest the importance of mutualism, empirical evidence for community-level impacts of mutualists has remained anecdotal, and the central role of mutualism, relative to other species interactions, has long been debated in the theoretical literature. Here I report the community-level consequences of a biological invasion that disrupts important seed-dispersal mutualisms. I show that invasion of South African shrublands by the Argentine ant (Linepithema humile) leads to a shift in composition of the plant community, owing to a disproportionate reduction in the densities of large-seeded plants. This study suggests that the preservation of mutualistic interactions may be essential for maintaining natural communities. 相似文献
376.
Christian Berger-Vachon Lionel Collet Neuroscience & Sensory Systems Laboratory 《系统仿真学报》2002,14(1):55-60
1 Introduction1 1.1 About Hearing Mechanisms The hearing function in human beings is something very specific and difficult to understand because it uses the brain highest functions. Basically, we can say (figure 1) that several stages are involved [1]: It is not easy to give a unique interpretation to each one of these stages, as most of the involved processes overlap at all levels. Nevertheless, as a brief summary, let us assume that [2]: l The ear transmits the air vibrations and transfor… 相似文献
377.
Niels Henrik Abel and solvable equations 总被引:1,自引:0,他引:1
Communicated by J. Lützen 相似文献
378.
Zusammenfassung
Alt-rezessive Erbsenpflanzen zeigen als Keimlinge normale Pigmentbildung, werden aber oberhalb des 5. oder 6. Knotens chlorotisch und sterben vor der Samenreife ab. Aufpfropfen des Wildtyps und Zugabe eines Extraktes regenerieren die Pigmentbildung in der Mutante, was auf die Anwesenheit einer übertragbaren, stark basischen Substanz schliessen lässt.
Approved by the Director of the New York Strate Agricultural Experiment Station, Geneva, New York, for publication as Journal paper No 1916.
The authors gratefully acknowledge the technical assistance of Mrs.Betty Chase, John F. Kenny andThomas G. Copeland. 相似文献
Approved by the Director of the New York Strate Agricultural Experiment Station, Geneva, New York, for publication as Journal paper No 1916.
The authors gratefully acknowledge the technical assistance of Mrs.Betty Chase, John F. Kenny andThomas G. Copeland. 相似文献
379.
Glucagon-like peptide-1(1-37) inhibits chemokine-induced migration of human CD4-positive lymphocytes
Nikolaus Marx Mathias Burgmaier Philipp Heinz Mirjam Ostertag Angelina Hausauer Helga Bach Renate Durst Vinzenz Hombach Daniel Walcher 《Cellular and molecular life sciences : CMLS》2010,67(20):3549-3555
The present study examined the effect of GLP-1(1-37) on chemokine-induced CD4-positive lymphocyte migration as an early and
critical step in atherogenesis. Pretreatment with GLP-1(1-37) reduced the SDF-induced migration of isolated human CD4-positive
lymphocytes in a concentration-dependent manner. Similar effects were seen when RANTES was used as a chemokine. GLP-1(1-37)’s
effect on CD4-positive lymphocyte migration was mediated through an early inhibition of chemokine-induced PI-3 kinase activity.
Downstream, GLP-1(1-37) inhibited SDF-induced phosphorylation of MLC and cofilin and limited f-actin formation as well as
ICAM3 translocation. Furthermore, exendin-4 inhibited SDF-induced migration of CD4-positive lymphocytes similarly to GLP-1(1-37),
and transfection of these cells with GLP-1 receptor siRNA abolished GLP-1(1-37)’s action on chemokine-induced ICAM3 translocation,
suggesting an effect mediated via the GLP-1 receptor. Thus, GLP-1(1-37) inhibits chemokine-induced CD4-positive lymphocyte
migration by inhibition of the PI3-kinase pathway and via the GLP-1 receptor. This effect provides a potential novel mechanism
for how GLP-1(1-37) may modulate vascular disease. 相似文献
380.