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11.
J. H. D. Bassett A. A. J. Pannett S. A. Forbes R. V. Thakker M. McCarthy A. P. Read B. T. Teh C. Larsson S. Kytölä J. Leisti P. Salmela G. Weber S. Giraud C. X. Zhang A. Calender J. W. M. Höppener H. K. Ploos van Amstel C. J. M. Lips K. Kas W. J. M. Van de Ven P. Gaudray 《Human genetics》1997,100(5-6):657-665
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by tumours of the parathyroids,
pancreas and anterior pituitary. The MEN1 gene has been localised to a 2-Mb region of chromosome 11q13 by meiotic mapping
studies in MEN1 families. Such studies may have a limited resolution of approximately 1 cM (i.e. 1 Mb) and we have therefore
investigated 96 MEN1 families (40 British, 17 French, 12 Finnish, 7 Swedish, 7 Dutch, 7 North American, 2 Australian, 1 New
Zealand, 1 German, 1 Spanish and 1 Danish) for linkage disequilibrium, in order to facilitate a finer mapping resolution.
We have utilised five microsatellite DNA sequence polymorphisms from the candidate region and have accurately determined their
allele sizes, which ranged from 161 bp to 272 bp. The heterozygosity and number of alleles (given in brackets), respectively,
at the loci were: D11S1883 (76%, 11), D11S457 (55%, 5), PYGM (94%, 18), D11S1783 (10%, 4) and D11S449 (87%, 16). Allelic association
was assessed by Chi-square 2 ×n contingency tables, by Fisher exact 2 ×n contingency tables and by a likelihood-based approach. The results of haplotype analysis revealed 91 different affected haplotypes
in the 96 families, an identical affected haplotype being observed in no more than two families. These results indicate the
absence of an ancestral affected haplotype. Significant linkage disequilibrium (P < 0.005) could be established amongst the microsatellite loci but not between the loci and MEN1 in either the total population
or in any of the geographical sub-populations. The absence of linkage disequilibrium between MEN1 and the polymorphic loci
is probably the result of the occurrence of multiple different disease-causing mutations in MEN1.
Received: 1 April 1997 / Accepted: 25 June 1997 相似文献
12.
Honghong Yang Yuanyuan Zhang Zhihai Wang Shixun Zhong Guohua Hu Wenqi Zuo 《Bioelectromagnetics》2020,41(3):219-229
To investigate the possible mechanisms for biological effects of 1,800 MHz mobile radiofrequency radiation (RFR), the radiation-specific absorption rate was applied at 2 and 4 W/kg, and the exposure mode was 5 min on and 10 min off (conversation mode). Exposure time was 24 h short-term exposure. Following exposure, to detect cell DNA damage, cell apoptosis, and reactive oxygen species (ROS) generation, the Comet assay test, flow cytometry, DAPI (4′,6-diamidino-2-phenylindole dihydrochloride) staining, and a fluorescent probe were used, respectively. Our experiments revealed that mobile phone RFR did not cause DNA damage in marginal cells, and the rate of cell apoptosis did not increase (P > 0.05). However, the production of ROS in the 4 W/kg exposure group was greater than that in the control group (P < 0.05). In conclusion, these results suggest that mobile phone energy was insufficient to cause cell DNA damage and cell apoptosis following short-term exposure, but the cumulative effect of mobile phone radiation still requires further confirmation. Activation of the ROS system plays a significant role in the biological effects of RFR. Bioelectromagnetics. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. 相似文献
13.
Cun-Feng Zhao Ran Wei Xian-Chun Zhang 《Cladistics : the international journal of the Willi Hennig Society》2020,36(4):443-445
Here, we publish Lepisorus sect. Paragramma (Blume) C.F. Zhao, R. Wei & X.C. Zhang as a combinatio nova to replace the section name in Zhao et al. (2020), which was published as a status nova and turned out to be an invalid name, because we cited an incorrect basionym. A revised infrageneric classification of Lepisorus also is proposed. 相似文献
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Structural Insight of a Trimodular Halophilic Cellulase with a Family 46 Carbohydrate-Binding Module
Huaidong Zhang Guimin Zhang Chaoxiang Yao Muhammad Junaid Zhenghui Lu Houjin Zhang Yanhe Ma 《PloS one》2015,10(11)
Cellulases are the key enzymes used in the biofuel industry. A typical cellulase contains a catalytic domain connected to a carbohydrate-binding module (CBM) through a flexible linker. Here we report the structure of an atypical trimodular cellulase which harbors a catalytic domain, a CBM46 domain and a rigid CBM_X domain between them. The catalytic domain shows the features of GH5 family, while the CBM46 domain has a sandwich-like structure. The catalytic domain and the CBM46 domain form an extended substrate binding cleft, within which several tryptophan residues are well exposed. Mutagenesis assays indicate that these residues are essential for the enzymatic activities. Gel affinity electrophoresis shows that these tryptophan residues are involved in the polysaccharide substrate binding. Also, electrostatic potential analysis indicates that almost the entire solvent accessible surface of CelB is negatively charged, which is consistent with the halophilic nature of this enzyme. 相似文献
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Low-level inversion of the L component of pseudorabies virus is not dependent on sequence homology. 下载免费PDF全文
G F Rall S Kupershmidt X Q Lu T C Mettenleiter T Ben-Porat 《Journal of virology》1991,65(12):7016-7019
Pseudorabies virus has a class 2 genome in which the S component is found in two orientations relative to the L component. The L component is bracketed by sequences that are partially homologous; it is found mainly in one orientation, but a small proportion is inverted (J. M. DeMarchi, Z. Lu, G. Rall, S. Kuperschmidt, and T. Ben-Porat, J. Virol. 64:4968-4977, 1990). We have ascertained the role of the patchy homologous sequences bracketing the L component in its inversion. A viral mutant, vYa, from which the sequences at the right end of the L component were deleted was constructed. Despite the absence of homologous sequences bracketing the L component in vYa, its L component inverted to an extent similar to that of the L component in the wild-type virus. These results show the following. (i) The low-frequency inversion of the L component of PrV is not mediated by homologous sequences bracketing this component. (ii) Cleavage of concatemeric DNA at the internal junction between the S and L components is responsible for the appearance of the minority of genomes with an inverted L component in populations of pseudorabies virus. (iii) The signals present near or at the end of the S component are sufficient to allow low-frequency cleavage of concatemeric DNA; the sequences at the end of the L component are not essential for cleavage, although they enhance it considerably. 相似文献
20.
A test of root growth inhibition of spruce and beech roots, according to Lynch's procedure (1977), shows the inhibitory effects of soil solution extracted from the holorganic layers (Of2-Oh) under beech and spruce. Molecular gel filtration of soil solutions shows that the molecular weights vary over a wide range, from less than 100 to over 40,000 daltons. Chemical analysis, using CGC, HPLC and sometimes MS shows only negligible concentrations of simple aliphatic (C1-C5) and aromatic acids in the free state. Using the fraction scheme of Forsyth (1977) and the carbazole procedure, it is shown that uronic acids represent only a small percentage of the carboxylic acids, and have no inhibitory effects on root growth. By analogy with results of other authors, the presence of polycarboxylic acids in the soil solution are considered to be the main cause of root growth inhibition. 相似文献