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1.
肺癌在中国恶性肿瘤的发病率位居第一,随着低剂量薄层CT在肺癌筛查中的广泛应用,临床发现更多表现为非完全实性结节的肺腺癌,目前众多研究使CT影像学特征和肺腺癌病理的关系得到更进一步的认知,虽然CT能对部分非完全实性结节做出定性和定位诊断,但仍有部分非完全实性结节诊断困难,PET-CT结合了病灶的代谢信息和精确的定位信息,从而提高对肺部结节诊断的敏感性、特异性、准确性,综合多个文献PET-CT在非完全实性结节中的诊断分期价值较CT无明显提升,却在评估预后和制定合适手术方案上可以起到一定的作用,本文就PET-CT在SSN中的应用价值进行阐述。 相似文献
2.
Molecular cloning of a cDNA for the E1 alpha subunit of rat liver branched chain alpha-ketoacid dehydrogenase 总被引:8,自引:0,他引:8
B Zhang M J Kuntz G W Goodwin R A Harris D W Crabb 《The Journal of biological chemistry》1987,262(31):15220-15224
We have isolated a cDNA encoding the branched chain alpha-ketoacid dehydrogenase E1 alpha subunit. A rat liver lambda gt11 expression library was screened with antibody reactive with the 2-oxoisovalerate dehydrogenase (lipoamide) component. A positive clone, lambda BZ304, contains a 1.7-kilobase pair cDNA insert with a 1323-base pair open reading frame. Translation of the open reading frame predicts the 24 residues of the previously reported phosphorylation sites 1 and 2 for the bovine kidney and rabbit heart enzymes. The N-terminal sequence of purified E1 alpha was determined, and this sequence was found 40 residues from the beginning of the deduced peptide sequence. Northern blots of rat liver and muscle RNA demonstrate a single mRNA species of approximately 1.8 kilobase pairs in each tissue, suggesting that this cDNA is nearly full length. 相似文献
3.
The complete primary structure of the cellular retinaldehyde-binding protein from bovine retina 总被引:4,自引:0,他引:4
J W Crabb C M Johnson S A Carr L G Armes J C Saari 《The Journal of biological chemistry》1988,263(35):18678-18687
Cellular retinaldehyde-binding protein (CRALBP) carries 11-cis-retinol and 11-cis-retinaldehyde as endogenous ligands and may be a functional component of the visual cycle. The complete amino acid sequence of CRALBP from bovine retina has been determined by direct microanalysis of the protein. Bovine CRALBP contains 316 residues in a single amino-terminal-blocked chain corresponding to a molecular weight of 36,421, inclusive of the blocking group. Overlapping peptides were generated by cleavage of lysyl, arginyl, methionyl, glutamyl, and one tryptophanyl bond and sequenced by gas-phase Edman degradation. Analysis of amino-terminal arginyl and methionyl peptides by fast atom bombardment mass spectrometry identified the N alpha-blocking group as an acetyl moiety, and tandem mass spectrometry provided the sequence of the first 9 residues. Comparison of CRALBP with other known protein sequences reveals no significant structural relatedness. The present results provide a basis for relating CRALBP domains with physiological function and for the future development of a more detailed three-dimensional model of the interaction of 11-cis-retinaldehyde with protein. 相似文献
4.
T4-induced alpha- and beta-glucosyltransferase: cloning of the genes and a comparison of their products based on sequencing data. 总被引:7,自引:3,他引:4 下载免费PDF全文
Bacteriophage T4 alpha- and beta-glucosyltransferases link glucosyl units to the 5-HMdC residues of its DNA. The monoglucosyl group in alpha-linkage predominates over the one in beta linkage. Having recently reported on the nucleotide sequence of gene alpha gt (1) we now determined the nucleotide sequence of gene beta gt. The genes were each cloned on a high expression vector under the control of the lambda pL promoter. After thermo-induction the proteins were isolated and purified to homogeneity. To verify that the translational starting sites and the proposed reading frames are effective in vivo the sequence of the first 31 amino acid residues from gp alpha gt and the first 30 amino acid residues from gp beta gt were determined by Edman degradation. The primary structures of the two proteins seem to have only limited structural similarities. The results are discussed comparing secondary structure predictions and homologies with other proteins from the protein sequence database of the Protein Identification Resource. 相似文献
5.
6.
Yuhsi Matuq Pamela S. Adams Nozomu Nishi Hidetaro Yasumitsu John W. Crabb Robert J. Matusik Wallace L. McKeehan 《In vitro cellular & developmental biology. Plant》1989,25(6):581-584
Summary Rat prostate extracts contain an abundant 20–22 kilodalton heparin-binding protein with near identical chromatographic properties,
but only 0.2–1% of the mitogenic activity, of bovine brain heparin-binding growth factor-1 (acidic fibroblast growth factor).
Amino terminal amino acid sequence (met-met-thr-asp-lys-asn-leu-lys-lys-lys-ile-glu-gly-asn-trp-arg-thr-val-tyr-leu-ala-ala-ser-?-val-glu-lys-ile-asn-glu-gly-ser-pro)
and immunochemical analysis revealed that the protein is identical to the androgen-dependent protein “probasin”.
This work was supported in part by NCI grant CA37589 (W. L. M., J. W. C.) and the Medical Research Council of Canada (R. J.
M.). 相似文献
7.
D W Crabb P M Stein K M Dipple J B Hittle R Sidhu M Qulali K Zhang H J Edenberg 《Genomics》1989,5(4):906-914
8.
When amphibian skin was incubated under conditions in which transepithelial sodium transport was abolished, a conductive transepithelial Cl- flux arose when Cl- was removed from one of the compartments. This flux was matched by short-circuit current and it accounted entirely for transepithelial conductance. Cl- influx was larger than efflux; it was linearly related to the magnitude of transepithelial Cl- concentration difference. When applied to the epithelial surface of the tissue, divalent metal cations such as Co2+, and the ethacrynic acid derivative, indacrinone, reduced rapidly and reversibly both transepithelial Cl- (in)flux and short-circuit current. Frog skin proved to be more sensitive to these inhibitors than toad skin. Further characterization of transepithelial Cl- pathway(s) should benefit from the fact that Cl- across amphibian skin can easily be monitored by the short-circuit current method, and from the availability of agents which inhibit this passive flux rapidly and reversibly. 相似文献
9.
Characterization of a truncated form of arrestin isolated from bovine rod outer segments. 总被引:6,自引:2,他引:4 下载免费PDF全文
K. Palczewski J. Buczylko H. Ohguro R. S. Annan S. A. Carr J. W. Crabb M. W. Kaplan R. S. Johnson K. A. Walsh 《Protein science : a publication of the Protein Society》1994,3(2):314-324
The inactivation of photolyzed rhodopsin requires phosphorylation of the receptor and binding of a 48-kDa regulatory protein, arrestin. By binding to phosphorylated photolyzed rhodopsin, arrestin inhibits G protein (Gt) activation and blocks premature dephosphorylation, thereby preventing the reentry of photolyzed rhodopsin into the phototransduction pathway. In this study, we isolated a 44-kDa form of arrestin, called p44, from fresh bovine rod outer segments and characterized its structure and function. A partial primary structure of p44 was established by a combination of mass spectrometry and automated Edman degradation of proteolytic peptides. The amino acid sequence was found to be identical with arrestin, except that the C-terminal 35 residues (positions 370-404) are replaced by a single alanine. p44 appeared to be generated by alternative mRNA splicing, because intron 15 interrupts within the nucleotide codon for 369Ser in the arrestin gene. Functionally, p44 binds avidly to photolyzed or phosphorylated and photolyzed rhodopsin. As a consequence of its relatively high affinity for bleached rhodopsin, p44 blocks Gt activation. The binding characteristics of p44 set it apart from tryptic forms of arrestin (truncated at the N- and C-termini), which require phosphorylation of rhodopsin for tight binding. We propose that p44 is a novel splice variant of arrestin that could be involved in the regulation of Gt activation. 相似文献
10.
Identification of tyrosines 154 and 307 in the extracellular domain and 653 and 766 in the intracellular domain as phosphorylation sites in the heparin-binding fibroblast growth factor receptor tyrosine kinase (flg). 总被引:3,自引:0,他引:3 下载免费PDF全文
J. Hou K. McKeehan M. Kan S. A. Carr M. J. Huddleston J. W. Crabb W. L. McKeehan 《Protein science : a publication of the Protein Society》1993,2(1):86-92
Four tyrosine residues have been identified as phosphorylation sites in the tyrosine kinase isoform of the heparin-binding fibroblast growth factor receptor flg (FGF-R1). Baculoviral-insect cell-derived recombinant FGF-R1 was phosphorylated and fragmented with trypsin while immobilized on heparin-agarose beads. Phosphotyrosine peptides were purified by chromatography on immobilized anti-phosphotyrosine antibody and analyzed by Edman degradation and electrospray tandem mass spectrometry. Tyrosine residue 653, which is in a homologous spatial position to major autophosphorylation sites in the catalytic domain of the src and insulin receptor kinases, is the major intracellular FGF-R1 phosphorylation site. Residue 766 in the COOH-terminus outside the kinase domain is a secondary site. Tyrosine residues 154 and 307, which are in the extracellular domain of transmembrane receptor isoforms and are in an unusual sequence context for tyrosine phosphorylation, were also phosphorylated. 相似文献