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91.
92.
Molly Vernersson Gunnar Pejler Therese Kristersson Kjell Alving L. Hellman 《Immunogenetics》1997,46(6):461-468
As a step in the evolutionary studies of immunoglobulin E (IgE) and for the purpose of developing new reagents that will
facilitate a more detailed analysis of IgE-mediated inflammatory reactions in a large animal model, we here present the cloning
of the ε chain of IgE in the domestic pig (Sus scrufa). A partial cDNA clone for the ε chain of pig IgE was isolated by polymerase chain reaction (PCR) amplification using degenerate
primers directed against conserved regions in the second (CH2) and the fourth (CH4) constant domains of IgE. cDNA derived
from mRNA isolated from the spleen and lymph nodes of a pig actively sensitized with a protein extract from the nematode Ascaris suum was used as template. Screening of a spleen cDNA library with the partial cDNA clone as probe resulted in isolation of a
clone that contained the entire coding region. The nucleotide sequence was determined and was found to conform with the previously
identified mammalian ε-chain sequences. The highest degree of similarity was found to sheep IgE. A DNA construct encoding
a baculovirus signal sequence, a histidine hexapeptide, and the CH2-CH3-CH4 domains of the pig IgE ε chain was obtained by
PCR amplification. The construct was ligated into the baculovirus expression vector pVL1392. Infection of High Five insect
cells with recombinant baculovirus resulted in expression and secretion of a soluble 6 × His-CH2-CH3-CH4 protein product.
Received: 9 April 1997 / Revised: 28 May 1997 相似文献
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Alfred Hellman Paul T. Peebles James E. Strickland Arnold K. Fowler S. S. Kalter S. Oroszlan R. V. Gilden 《Journal of virology》1974,14(1):133-138
A virus (M-7) isolated from baboon placental tissue demonstrates many similarities to endogenous feline virus RD-114. Immunodiffusion analysis shows a group-specific antigen (gs-1) line of identity between M-7 and RD-114. Anti-RD-114 DNA polymerase IgG inhibits M-7 polymerase by 57% compared to 97% for RD-114. M-7 virus has helper activity as demonstrated by rescue of murine sarcoma virus (MSV) from sarcoma-positive leukemia-negative human amnion cells. The host range of the rescued M-7 pseudotype of MSV, MSV (M-7), is similar to that of RD-114 virus. MSV (M-7) is also able to transform baboon cells and causes no detectable transformation of feline cells without addition of helper feline leukemia virus. Interference properties of M-7 and RD-114 virus are identical. Virus-specific neutralizing antisera, although partially cross-reacting, can distinguish MSV (M-7) from MSV (RD-114). These similarities and differences between RD-114 and M-7 viruses are best explained as type-specific differences between two viruses within the same strain. 相似文献
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98.
Identification of a polypeptide growth inhibitor from bovine mammary gland. Sequence homology to fatty acid- and retinoid-binding proteins 总被引:9,自引:0,他引:9
F D B?hmer R Kraft A Otto C Wernstedt U Hellman A Kurtz T Müller K Rohde G Etzold W Lehmann 《The Journal of biological chemistry》1987,262(31):15137-15143
A polypeptide growth inhibitor purified from bovine mammary gland (mammary-derived growth inhibitor) has been shown to reversibly inhibit proliferation of mammary carcinoma cells at concentrations of about 10(-10) M. The carrier of inhibitory activity has been identified biochemically as an about 13-kDa polypeptide and chemically by elucidating the amino acid sequence. No homology to any of the hitherto structurally investigated growth inhibitors (transforming growth factor beta, interferons) has been observed. The data revealed extensive sequence homology of mammary-derived growth inhibitor to a family of low molecular mass hydrophobic ligand-binding proteins, among them a fatty acid-binding protein from rat heart, myelin P2, a differentiation associated protein in adipocytes (p422) and the cellular retinoic acid-binding protein. Interaction with as yet unknown hydrophobic ligands might play a functional role in the mechanism of growth inhibition excerted by mammary-derived growth inhibitor. 相似文献
99.
The effects of 1,2-dibromoethane (DBE) and 1,2-dichloroethane (DCE) on the incorporation of [3H]thymidine into DNA were evaluated in various tissues of mice. The compounds were given intraperitoneally 24 h before sacrifice in an equimolar dose (293 mumoles/kg body weight). 2 h before the animals were killed, 0.5 mu Ci [3H]thymidine/g body weight was injected intraperitoneally. Both agents inhibited the [3H]thymidine incorporation in the forestomach, a site for their carcinogenic action. Whereas DBE also suppressed the [3H]thymidine incorporation in the nasal mucosa, the thymus, and the "glandular stomach", DCE was inhibitory only in the kidney. The observed difference in the effect of DBE and DCE on the thymus had its counterpart in a DBE-induced decrease of acid-insoluble radioactivity, demonstrated with whole-body autoradiography. The results indicate that in vivo screening of [3H]thymidine incorporation into various organs of an intact experimental animal is a sensitive technique for comparing cyto- and/or genotoxic effects of chemicals with a similar chemical structure. 相似文献
100.
The sodium contents of -cell-rich pancreatic islets fromob/ob-mice were measured with an integrating flame photometer. After washing to an apparent steady state with different types of ice-cold media, islets incubated in the absence of glucose contained 79–108 mmol sodium kg–1 dry weight. Exposure to glucose resulted in 25 % reduction of the islet content of sodium. This effect became manifest in the presence of 5 mM glucose, there being no additional reduction with a further increase of glucose to 20 mM. Depression of Na+ activity may partially explain why glucose, under certain conditions, can lower cytoplasmic Ca2+ and even inhibit insulin release. 相似文献