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51.
p38alpha MAP kinase is essential in lung stem and progenitor cell proliferation and differentiation 总被引:5,自引:0,他引:5
Ventura JJ Tenbaum S Perdiguero E Huth M Guerra C Barbacid M Pasparakis M Nebreda AR 《Nature genetics》2007,39(6):750-758
Stem cell function is central for the maintenance of normal tissue homeostasis. Here we show that deletion of p38alpha mitogen-activated protein (MAP) kinase in adult mice results in increased proliferation and defective differentiation of lung stem and progenitor cells both in vivo and in vitro. We found that p38alpha positively regulates factors such as CCAAT/enhancer-binding protein that are required for lung cell differentiation. In addition, p38alpha controls self-renewal of the lung stem and progenitor cell population by inhibiting proliferation-inducing signals, most notably epidermal growth factor receptor. As a consequence, the inactivation of p38alpha leads to an immature and hyperproliferative lung epithelium that is highly sensitized to K-Ras(G12V)-induced tumorigenesis. Our results indicate that by coordinating proliferation and differentiation signals in lung stem and progenitor cells, p38alpha has a key role in the regulation of lung cell renewal and tumorigenesis. 相似文献
52.
Delous M Baala L Salomon R Laclef C Vierkotten J Tory K Golzio C Lacoste T Besse L Ozilou C Moutkine I Hellman NE Anselme I Silbermann F Vesque C Gerhardt C Rattenberry E Wolf MT Gubler MC Martinovic J Encha-Razavi F Boddaert N Gonzales M Macher MA Nivet H Champion G Berthélémé JP Niaudet P McDonald F Hildebrandt F Johnson CA Vekemans M Antignac C Rüther U Schneider-Maunoury S Attié-Bitach T Saunier S 《Nature genetics》2007,39(7):875-881
Cerebello-oculo-renal syndrome (CORS), also called Joubert syndrome type B, and Meckel (MKS) syndrome belong to the group of developmental autosomal recessive disorders that are associated with primary cilium dysfunction. Using SNP mapping, we identified missense and truncating mutations in RPGRIP1L (KIAA1005) in both CORS and MKS, and we show that inactivation of the mouse ortholog Rpgrip1l (Ftm) recapitulates the cerebral, renal and hepatic defects of CORS and MKS. In addition, we show that RPGRIP1L colocalizes at the basal body and centrosomes with the protein products of both NPHP6 and NPHP4, known genes associated with MKS, CORS and nephronophthisis (a related renal disorder and ciliopathy). In addition, the RPGRIP1L missense mutations found in CORS individuals diminishes the interaction between RPGRIP1L and nephrocystin-4. Our findings show that mutations in RPGRIP1L can cause the multiorgan phenotypic abnormalities found in CORS or MKS, which therefore represent a continuum of the same underlying disorder. 相似文献
53.
Proteorhodopsin phototrophy in the ocean. 总被引:44,自引:0,他引:44
Proteorhodopsin, a retinal-containing integral membrane protein that functions as a light-driven proton pump, was discovered in the genome of an uncultivated marine bacterium; however, the prevalence, expression and genetic variability of this protein in native marine microbial populations remain unknown. Here we report that photoactive proteorhodopsin is present in oceanic surface waters. We also provide evidence of an extensive family of globally distributed proteorhodopsin variants. The protein pigments comprising this rhodopsin family seem to be spectrally tuned to different habitats--absorbing light at different wavelengths in accordance with light available in the environment. Together, our data suggest that proteorhodopsin-based phototrophy is a globally significant oceanic microbial process. 相似文献
54.
Summary Some trace metals are required for development and reproduction, and therefore for continuous rearing of the aster leafhopper,Macrosteles fascifrons, on a holidic diet. Requirement for Fe+++ becomes apparent immediately in the 1st generation; for Cu++ and Zn++, in the 3rd. The leafhopper has grown normally and continuously for 3 generations in the absence of manganese.We acknowledge the Minnesota Agricultural Experiment Station and the National Institute of Allergy and Infectious Diseases, USA, for financial supports. 相似文献
55.
Jamain S Quach H Betancur C Råstam M Colineaux C Gillberg IC Soderstrom H Giros B Leboyer M Gillberg C Bourgeron T;Paris Autism Research International Sibpair Study 《Nature genetics》2003,34(1):27-29
Many studies have supported a genetic etiology for autism. Here we report mutations in two X-linked genes encoding neuroligins NLGN3 and NLGN4 in siblings with autism-spectrum disorders. These mutations affect cell-adhesion molecules localized at the synapse and suggest that a defect of synaptogenesis may predispose to autism. 相似文献
56.
Zusammenfassung Papierchromatographisch wurde Murein in symbiontischen Bakteroiden derPeriplaneta americana nachgewiesen. Die Murein-Komponente Glukosamin und der Murein-Anzeiger Muramic-Säure wurden mittels Bakteroid-Hydrolysaten identifiziert. Das Vorhandensein von --Diaminopimelic-Säure jedoch konnte nicht einwandfrei festgestellt werden.
This is paper No. 6175, Scientific Journal Series, Minnesota Agricultural Experiment Station, St. Paul (Minnesota, USA). The work was supported by U.S. Public Health Service Research Grant No. AI 00961, from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health. 相似文献
This is paper No. 6175, Scientific Journal Series, Minnesota Agricultural Experiment Station, St. Paul (Minnesota, USA). The work was supported by U.S. Public Health Service Research Grant No. AI 00961, from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health. 相似文献
57.
Marion K. Birmingham W. E. Stumpf M. Sar 《Cellular and molecular life sciences : CMLS》1979,35(9):1240-1241
Summary Autoradiographic studies with3H aldosterone demonstrate nuclear concentration of hormone in neurons of the hippocampus, septum, allocortical regionss and brain stem reticular formation and motor nuclei of cranial nerves and in the meninges. The results suggest that mineralocorticoids have wide ranging effects on different parts of the central nervous system.This work was supported by the Medical Research Council of Canada and by PHS grant NS09914. We thank Ms Brenda McClain for technical assistance. 相似文献
58.
Lymphoid tissue genesis induced by commensals through NOD1 regulates intestinal homeostasis 总被引:1,自引:0,他引:1
Intestinal homeostasis is critical for efficient energy extraction from food and protection from pathogens. Its disruption can lead to an array of severe illnesses with major impacts on public health, such as inflammatory bowel disease characterized by self-destructive intestinal immunity. However, the mechanisms regulating the equilibrium between the large bacterial flora and the immune system remain unclear. Intestinal lymphoid tissues generate flora-reactive IgA-producing B cells, and include Peyer's patches and mesenteric lymph nodes, as well as numerous isolated lymphoid follicles (ILFs). Here we show that peptidoglycan from Gram-negative bacteria is necessary and sufficient to induce the genesis of ILFs in mice through recognition by the NOD1 (nucleotide-binding oligomerization domain containing 1) innate receptor in epithelial cells, and beta-defensin 3- and CCL20-mediated signalling through the chemokine receptor CCR6. Maturation of ILFs into large B-cell clusters requires subsequent detection of bacteria by toll-like receptors. In the absence of ILFs, the composition of the intestinal bacterial community is profoundly altered. Our results demonstrate that intestinal bacterial commensals and the immune system communicate through an innate detection system to generate adaptive lymphoid tissues and maintain intestinal homeostasis. 相似文献
59.
李河宗 董湘怀 申昱 Alexander Diehl Hinnerk Hagenah Ulf Engel Marion Merklein 《上海交通大学学报》2011,45(11):1668-1672
通过黄铜板料微弯曲实验,发现其弯曲弯矩存在明显的尺寸效应现象,随板料厚度的减小,弯曲弯矩增大.采用经典塑性理论和不同的应变梯度理论对微弯曲弯矩进行了预测,对比分析结果表明:修正的Nix Gao模型的预测结果更接近于实验结果,并且得出了合理的内禀尺寸表达式;该内禀尺寸与材料的剪切模量、初始屈服极限、柏氏矢量和板料厚度方向上的孪晶数有关. 相似文献