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991.
Antibodies to adenosine-5'-monophosphate were produced in rabbits by injecting a conjugate of the nucleotide (oxidized with periodate) with bovine serum albumin. Nucleotide-specific antibodies were isolated by affinity chromatography on oligoadenylic acids/agarose column. Pure immunoglobulin G antibodies were obtained by gel filtration on Sephadex G-200. These antibodies, as analyzed by double diffusion react with adenosine 5'-monophosphate--bovine serum albumin, slightly with inosine-5'-monophosphate conjugate and not at all with the other nucleotide conjugates. The association constants for adenosine-5'-monophosphate--antibody complex formation obtained by dialysis equilibrium and fluorescence measurements, are in good agreement. This latter technique was used to study on one hand the influence of temperture and salt on complex formation, on the other hand the interaction of the antibodies with AMP derivatives. The phosphate group, the ribose and the base are recognized by the antibody, but the C-8 atom of adenine residues is not directly involved in the binding. 相似文献
992.
Xinxing Wang Jingbo Gong Xiaohua Liu Rui Zhan Ruirui Kong Yun Zhao Di Wan Xue Leng Ming Chen Lingjia Qian 《Cell stress & chaperones》2010,15(6):771-779
It has been confirmed that stress plays an important role in the induction and development of cardiovascular diseases, but
its mechanism and molecular basis remain unknown. In the present study, a myocardial injury model induced by restraint stress
was established in rat. To screen for the related proteins involved in stress-induced myocardial injury, proteomic techniques
based on 2-DE and mass spectrometry were used. In our results, ten proteins were found to be altered. The expression of eight
of these proteins was increased after restraint stress, including cardiac myosin heavy chain, dihydrolipoamide succinyltransferase
component of 2-oxoglutarate dehydrogenase complex, mitochondrial aldehyde dehydrogenase, H+-transporting ATP synthase, albumin, and apolipoprotein A-I precursor. The expression of uncoupling protein 3 (UCP3) and mitochondrial
aconitase was decreased. Most of the proteins were related to energy metabolism. Further research indicated that UCP3 may
mediate the myocardial cell response induced by restraint stress. 相似文献
993.
994.
M.C. Lang G. de Murcia A. Mazen R.P.P. Fuchs M. Leng M. Daune 《Chemico-biological interactions》1982,41(1):83-93
The influence of chromatin structure on the accessibility of DNA to the model ultimate carcinogen N-acetoxy-N-2-acetylaminofluorene (N-Aco-AAF) was investigated by means of an immunoelectron microscopic technique developed recently. An homogeneous population of core particles or trinucleosomes from chicken erythrocytes, was submitted to electrophilic attack by N-Aco-AAF. After DNA isolation, N-2-acetylaminofluorene (AAF) binding sites were mapped upon the DNA fragments using specific antibodies as a probe. Our results indicate a non-random binding of AAF along the DNA. Our data support the results of previous studies showing a preferential binding on the linker region. 相似文献
995.
Climate Versus In-Lake Processes as Controls on the Development of Community Structure in a Low-Arctic Lake (South-West Greenland) 总被引:3,自引:0,他引:3
N. John Anderson Klaus P. Brodersen David B. Ryves Suzanne McGowan Liselotte S. Johansson Erik Jeppesen Melanie J. Leng 《Ecosystems》2008,11(2):307-324
The dominant processes determining biological structure in lakes at millennial timescales are complex. In this study, we used
a multi-proxy approach to determine the relative importance of in-lake versus indirect processes on the Holocene development
of an oligotrophic lake in SW Greenland (66.99°N, 50.97°W). A 14C and 210Pb-dated sediment core covering approximately 8500 years BP was analyzed for organic–inorganic carbon content, pigments, diatoms,
chironomids, cladocerans, and stable isotopes (δ13C, δ18O). Relationships among the different proxies and a number of independent controlling variables (Holocene temperature, an
isotope-inferred cooling period, and immigration of Betula nana into the catchment) were explored using redundancy analysis (RDA) independent of time. The main ecological trajectories in
the lake biota were captured by ordination first axis sample scores (18–32% variance explained). The importance of the arrival
of Betula (ca. 6500 years BP) into the catchment was indicated by a series of partial-constrained ordinations, uniquely explaining
12–17% of the variance in chironomids and up to 9% in pigments. Climate influences on lake biota were strongest during a short-lived
cooling period (identified by altered stable isotopes) early in the development of the lake when all proxies changed rapidly,
although only chironomids had a unique component (8% in a partial-RDA) explained by the cooling event. Holocene climate explained
less variance than either catchment changes or biotic relationships. The sediment record at this site indicates the importance
of catchment factors for lake development, the complexity of community trends even in relatively simple systems (invertebrates
are the top predators in the lake) and the challenges of deriving palaeoclimate inferences from sediment records in low-Arctic
freshwater lakes. 相似文献