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831.
T. Okabe K. Hirashima T. Terasima B. Shimizu N. Ohsawa F. Takaku 《Cellular and molecular life sciences : CMLS》1984,40(9):982-984
Summary A human colony-stimulating factor (CSF)-producing tumor transplanted into athymic nude mice released retroviruses in vitro. The viruses induced CSF activity in human fibroblastic cell lines. 相似文献
832.
M. Nishikimi N. Yamauchi K. Kiuchi K. Yagl 《Cellular and molecular life sciences : CMLS》1981,37(5):479-480
Summary Immunological cross-reactivity of L-gulonolactone oxidase of different species (rat, chicken, and bullfrog) was tested by the Ouchterlony technique. Antiserum directed against the enzyme from chicken kidney reacted with rat liver enzyme as well as with bullfrog kidney enzyme. This finding suggests that there is, at least partly, sequence homology among the enzymes from species belonging to the three classes, Mammalia, Aves, and Amphibia. 相似文献
833.
N. S. Agar 《Cellular and molecular life sciences : CMLS》1979,35(6):790-791
Summary The activity of sorbitol dehydrogenase was found to be high in the red blood cells of man, dog, guinea-pig and mouse and comparatively lower in those of goat, sheep, rabbit, cat and rat. 相似文献
834.
Acute renal failure (ARF) was associated with increased urinary thromboxane (TXA2) excretion and lessened excretion of sodium (UNaV) and fractional excretion of sodium (FENa%). The inhibitor of thromboxane A2-synthetase OKY-046 enhanced sodium excretion and fractional excretion of sodium in normal and saline loaded animals whereas it partially prevented the reduction in sodium excretion and creatinine clearance and significantly increased fractional excretion of sodium in glycerol treated rats suggesting a partial protection against the development of acute renal failure. 相似文献
835.
V. H. Rao I. V. Mongha M. R. Ansari N. K. Bhattacharyya 《Cellular and molecular life sciences : CMLS》1984,40(8):821-822
Summary Frozen storage of rabbit embryos at the 16-cell stage in 2.0 M dimethylsulfoxide (DMSO) in phosphate-buffered saline (PBS) was achieved by a 2-step procedure. After storage for 10 days at–196°C they were revived by rapidly thawing at 500°C/min. On transfer of these embryos to pseudopregnant foster mothers, 50% survived to term. The difference in in vivo survival between frozen-thawed and frozen-thawed-cultured embryos was not significant.Acknowledgment. The authors thank the Director for the facilities. VHR is supported by Council of Scientific and Industrial Research (India). 相似文献
836.
The polypeptide chain of the acid protease penicillo pepsin folds via an 18-stranded mixed beta-sheet into two distinct lobes separated by a 30-A long groove which is the extended substrate binding site. The catalytic residues Asp-32 and Asp-215 are located in this groove and their carboxyl groups are in intimate contact. Alignment of the amino acid sequence with that of pepsin shows regions of high homology. 相似文献
837.
I. M. Varndell A. Harris F. J. Tapia N. Yanaihara J. De Mey S. R. Bloom J. M. Polak 《Cellular and molecular life sciences : CMLS》1983,39(7):713-717
Summary Gastrin (G)-producing cells from the mammalian gastric antrum have been investigated using computer-assisted morphometry and a novel double colloidal gold-labeled-immunoglobulin electron immunocytochemical procedure. Correlation analysis of human antral G-cells indicates (p<0.001) that a single population of granules exists with small (160 nm) electron-dense and large (240 nm) electron-lucent forms representing the extremes. Non-crossreacting region-specific antisera have been used to visualize G-17 and G-34 (progastrin) to the small electron-dense granules and G-17 to the other intermediate forms. From the results we propose a topographic segregation of immunoreactive gastrins within 2 apparently distinct granule subclasses and suggest that this may represent the pathway of granule maturation. 相似文献
838.
G. P. McGregor A. E. Bishop M. A. Blank N. D. Christofides Y. Yiangou J. M. Polak S. R. Bloom 《Cellular and molecular life sciences : CMLS》1984,40(5):469-471
Summary In the feline gastrointestinal tract, the neuropeptides, substance P, VIP and PHI were investigated by specific radioimmunoassays and immunocytochemistry. The concentrations of all 3 peptides and the level of peptidergic innervation were significantly less in the anal sphincter than elsewhere, whereas no significant differences were seen between other sphincter and non-sphincter regions. 相似文献
839.
N Matsunami B Smith L Ballard M W Lensch M Robertson H Albertsen C O Hanemann H W Müller T D Bird R White 《Nature genetics》1992,1(3):176-179
Charcot-Marie-Tooth disease 1A (CMT1A) is a hereditary demyelinating peripheral neuropathy, associated with a DNA duplication on chromosome 17p11.2. A related disorder in the mouse, trembler (Tr), maps to mouse chromosome 11 which has syntenic homology to human chromosome 17p. Recently, the peripheral myelin protein-22 (pmp-22) gene was identified as the likely Tr locus. We have constructed a partial yeast artificial chromosome contig spanning the CMT1A gene region and mapped the PMP-22 gene to the duplicated region. These observations further implicate PMP-22 as a candidate gene for CMT1A, and suggest that over-expression of this gene may be one mechanism that produces the CMT1A phenotype. 相似文献
840.
Site-directed mutagenesis reveals role of mobile arginine residue in lactate dehydrogenase catalysis 总被引:6,自引:0,他引:6
The binding of substrates to lactate dehydrogenases induces a marked rearrangement of the protein structure in which a 'loop' of polypeptide (residues 98-110) closes over the active site of the enzyme. In this rearrangement, arginine 109 (a basic residue conserved in all known lactate dehydrogenase sequences and in the homologous malate dehydrogenases) moves 0.8 nm from a position in the solvent to one in the active site where its guanidinium group resides within hydrogen bonding distance of both the reactive carbonyl of pyruvate and imidazole ring of the catalytic histidine 195 (see Fig. 1). Whilst this feature of the enzyme has been commented upon previously, the function of this mobile arginine residue during catalysis has not been tested experimentally. The advent of protein engineering has now enabled us to define the role of this basic residue by substituting it with the neutral glutamine. Transient kinetic and equilibrium studies of the mutant enzyme indicate that arginine 109 enhances the polarization of the pyruvate carbonyl group in the ground state and stabilizes the transition state. The gross active-site structure of the enzyme is not altered by the mutation since an alternative catalytic function of the enzyme (rate of addition of sulphite to NAD+), which does not require hydride transfer, is insensitive to the arginine----glutamine substitution. 相似文献