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951.
Priscila Guimarães Otto Sergio Toledo Antonio Richieri-Costa Paulo Alberto Otto Angela M. Vianna-Morgante Sanae Kasahara 《Human genetics》1978,41(3):243-250
Summary Two patients are described with a monosomy for the proximal part of the long arm of chromosome 13 and for the distal part of the long arm of chromosome 21, due to an unbalanced 13/21 translocation. 相似文献
952.
Erika Feltrin Stefano Campanaro Alexander D Diehl Elisabeth Ehler Georgine Faulkner Jennifer Fordham Chiara Gardin Midori Harris David Hill Ralph Knoell Paolo Laveder Lorenza Mittempergher Alessandra Nori Carlo Reggiani Vincenzo Sorrentino Pompeo Volpe Ivano Zara Giorgio Valle Jennifer Deegan née Clark 《BMC medical genomics》2009,2(1):1-8
953.
Midori Umekawa Cishan Li Takayuki Higashiyama Wei Huang Hisashi Ashida Kenji Yamamoto Lai-Xi Wang 《The Journal of biological chemistry》2010,285(1):511-521
Endo-M, an endo-β-N-acetylglucosaminidase from Mucor hiemalis, is a family 85 glycoside hydrolase. This enzyme is unique in that it can transfer en bloc the oligosaccharide of various types of N-glycans onto different acceptors, and thereby it enzymatically generates diverse glycoconjugates. In this study, we performed mutational and kinetic studies focusing on a key catalytic asparagine 175 of Endo-M. We have shown that most of the Asn-175 mutants had significantly diminished hydrolysis activity but acted as glycosynthases capable of using synthetic sugar oxazoline for transglycosylation. Our results confirm the critical role of this asparagine residue in promoting the formation of an oxazolinium ion intermediate in the first step of the substrate-assisted catalysis. Interestingly, the N175Q mutant was found to possess dramatically enhanced glycosynthase-like activity with sugar oxazoline in comparison with N175A and a transglycosidase-like activity with “natural” N-glycan as well. These results also implicated the significance of amide side chain in the asparagine 175 of Endo-M for promoting oxazoline transglycosylation in the second step of the catalysis. The highly efficient syntheses of glycopeptides/glycoproteins by N175Q combined with synthetic sugar oxazolines or natural N-glycan substrates were exemplified. In addition, we also identified several previously unknown residues that seem to play a role in the catalysis of Endo-M. 相似文献
954.
Yoshihiro Nakata Hirotaka Ode Mai Kubota Takaaki Kasahara Kazuhiro Matsuoka Atsuko Sugimoto Mayumi Imahashi Yoshiyuki Yokomaku Yasumasa Iwatani 《Nucleic acids research》2023,51(2):783
The number of genetic variations in the SARS-CoV-2 genome has been increasing primarily due to continuous viral mutations. Here, we report that the human APOBEC3A (A3A) cytidine deaminase plays a critical role in the induction of C-to-U substitutions in the SARS-CoV-2 genome. Bioinformatic analysis of the chronological genetic changes in a sequence database indicated that the largest UC-to-UU mutation signature, consistent with APOBEC-recognized nucleotide motifs, was predominant in single-stranded RNA regions of the viral genome. In SARS-CoV-2-infected cells, exogenous expression of A3A but not expression of other APOBEC proteins induced UC-to-UU mutations in viral RNA (vRNA). Additionally, the mutated C bases were often located at the tips in bulge or loop regions in the vRNA secondary structure. Interestingly, A3A mRNA expression was drastically increased by interferons (IFNs) and tumour necrosis factor-α (TNF-α) in epithelial cells derived from the respiratory system, a site of efficient SARS-CoV-2 replication. Moreover, the UC-to-UU mutation rate was increased in SARS-CoV-2 produced from lung epithelial cells treated with IFN-ß and TNF-α, but not from CRISPR/Cas9-based A3A knockout cells. Collectively, these findings demonstrate that A3A is a primary host factor that drives mutations in the SARS-CoV-2 RNA genome via RNA editing. 相似文献
955.
Toru Sengoku Masaaki Shiina Kae Suzuki Keisuke Hamada Ko Sato Akiko Uchiyama Shunsuke Kobayashi Asako Oguni Hayato Itaya Kota Kasahara Hirotomo Moriwaki Chiduru Watanabe Teruki Honma Chikako Okada Shiho Baba Tsutomu Ohta Hozumi Motohashi Masayuki Yamamoto Kazuhiro Ogata 《Nucleic acids research》2022,50(21):12543
956.
We previously reported the cloning of a wheat sucrose:sucrose 1-fructosyltransferase (1-SST) cDNA, designated wft2. Wft2 proteins have fructosyltransferase enzyme activity and initiate fructan synthesis (Biosci. Biotechnol. Biochem. 66 (2002) 2297). In the current study, we cloned a genomic DNA fragment carrying the full-length 1-SST gene from winter wheat (Triticum aestivum). The genomic 1-SST gene is 3326 bp in length and contains four exons and three introns. Exon 2 has only 9 bp. This sequence encodes a part of a beta-fructosidase motif (NDPNG), a highly conserved motif found in plant invertases. This is the first report of a mini exon, one of the smallest exons known in plants, being found in a genomic 1-SST gene. 相似文献
957.
The fission yeast Schizosaccharomyces japonicus has recently emerged as a powerful system for studying the evolution of essential cellular processes, drawing on similarities as well as key differences between S. japonicus and the related, well-established model Schizosaccharomyces pombe. We have deployed the open-source, modular code and tools originally developed for PomBase, the S. pombe model organism database (MOD), to create JaponicusDB (www.japonicusdb.org), a new MOD dedicated to S. japonicus. By providing a central resource with ready access to a growing body of experimental data, ontology-based curation, seamless browsing and querying, and the ability to integrate new data with existing knowledge, JaponicusDB supports fission yeast biologists to a far greater extent than any other source of S. japonicus data. JaponicusDB thus enables S. japonicus researchers to realize the full potential of studying a newly emerging model species and illustrates the widely applicable power and utility of harnessing reusable PomBase code to build a comprehensive, community-maintainable repository of species-relevant knowledge. 相似文献
958.
959.
T Itoh M Nakamura H Yagi H Soga H Doi S Koja M Nanno R Suzuki S Satomi S Kasahara 《Cellular and molecular biology, including cyto-enzymology》2001,47(1):1-18
Interactions between thymocytes and thymic stromal cells are essential for thymocyte differentiation, but little evidence has been presented to directly show in vivo functions or interactions of the stromal cells. Among the stromal cells, the thymic epithelial cell has been considered to have profound effect on thymocyte differentiation and maturation. The calcium-depleted medium, originally developed for the culture of mouse epidermal cells, was applied for the culture of the mouse thymic epithelial cells, and successfully, an epithelial cell line, IT-76MHC was obtained from the mouse thymus. IT-76MHC cells were identified as distinct mouse thymic epithelial cells by 1/ mosaic-like arrangement, 2/ presence of well-developed desmosome and 3/ tonofilaments, 4/ positivity for cytokeratin, and 5/ induced expression of MHC class I and II by IFN-gamma treatment. IGF-1, IGF-2, oxytocin and vasopressin were also detected immunohistochemically in IT-76MHC cells. Furthermore, the IT-76MHC thymic epithelial cells, when injected intrathymically in the allogeneic mouse, prolonged the survival of skin graft from the same donor strain that IT-76MHC cells were derived. These results demonstrate that the thymic epithelial cell line IT-76MHC produces modest thymocyte survival factors as well as a growth suppressor, and that IT-76MHC cells have the ability to induce transplantation tolerance probably through their expression of MHC class I and II molecules. Taken altogether, the IT-76MHC thymic epithelial cells have been proved to be useful tools to better understand the in vivo functions of thymic epithelial cells, and to gain a deep insight into their involvement in the critical selection process of thymocytes which still remains obscure. Finally and additionally, literatures so far reported on thymic epithelial cells in culture, especially lines and clones, are reviewed and their identity as well as their functions are discussed. 相似文献
960.
Y. Suto Yoshihide Ishikawa Masanori Kasahara Fumio Kasai Toshio Yabe Tatsuya Akaza Takeo Juji 《Immunogenetics》1998,48(4):235-241
Human chromosome 19q13.4 has recently been revealed to be a remarkable region harboring multiple receptor genes of the immunoglobulin
(Ig) superfamily differentially expressed on hematopoietic cell lineages. Over the past few years, more than 50 cDNAs have
been cloned for the natural killer cell inhibitory receptor (KIR) gene family, which possess two or three Ig-like domains in the extracellular region. In this study, using two genomic DNA
probes containing intron sequences of genes corresponding to the two- and three-domain types, we applied two-color-fluorescence
in situ hybridization on stretched DNA fiber preparations (fiber-FISH). As a result, 11 positions homologous to KIR genes were found as a cluster within a range of approximately 120 kilobases on a chromatin fiber from human chromosome 19.
Received: 7 January 1998 / Revised: 25 February 1998 相似文献