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991.
Wagner PJ 《Biology letters》2012,8(1):143-146
Rate distributions are important considerations when testing hypotheses about morphological evolution or phylogeny. They also have implications about general processes underlying character evolution. Molecular systematists often assume that rates are Poisson processes with gamma distributions. However, morphological change is the product of multiple probabilistic processes and should theoretically be affected by hierarchical integration of characters. Both factors predict lognormal rate distributions. Here, a simple inverse modelling approach assesses the best single-rate, gamma and lognormal models given observed character compatibility for 115 invertebrate groups. Tests reject the single-rate model for nearly all cases. Moreover, the lognormal outperforms the gamma for character change rates and (especially) state derivation rates. The latter in particular is consistent with integration affecting morphological character evolution. 相似文献
992.
Brauer C Hennig-Pauka I Hoeltig D Buettner FF Beyerbach M Gasse H Gerlach GF Waldmann KH 《BMC veterinary research》2012,8(1):47
ABSTRACT: BACKGROUND: In pigs, diseases of the respiratory tract like pleuropneumonia due to Actinobacillus pleuropneumoniae (App) infection have led to high economic losses for decades. Further research on disease pathogenesis, pathogen-host-interactions and new prophylactic and therapeutic approaches are needed. In most studies, a large number of experimental animals are required to assess lung alterations at different stages of the disease. In order to reduce the required number of animals but nevertheless gather information on the nature and extent of lung alterations in living pigs, a computed tomographic scoring system for quantifying gross pathological findings was developed. In this study, five healthy pigs served as control animals while 24 pigs were infected with App, the causative agent of pleuropneumonia in pigs, in an established model for respiratory tract disease. RESULTS: Computed tomographic (CT) findings during the course of App challenge were verified by radiological imaging, clinical, serological, gross pathology and histological examinations. Findings from clinical examinations and both CT and radiological imaging, were recorded on day 7 and day 21 after challenge. Clinical signs after experimental App challenge were indicative of acute to chronic disease. Lung CT findings of infected pigs comprised ground-glass opacities and consolidation. On day 7 and 21 the clinical scores significantly correlated with the scores of both imaging techniques. At day 21, significant correlations were found between clinical scores, CT scores and lung lesion scores. In 19 out of 22 challenged pigs the determined disease grades (not affected, slightly affected, moderately affected, severely affected) from CT and gross pathological examination were in accordance. Disease classification by radiography and gross pathology agreed in 11 out of 24 pigs. CONCLUSIONS: High-resolution, high-contrast CT examination with no overlapping of organs is superior to radiography in the assessment of pneumonic lung lesions after App challenge. The new CT scoring system allows for quantification of gross pathological lung alterations in living pigs. However, computed tomographic findings are not informative of the etiology of respiratory disease. 相似文献
993.
Tang Q Grzywacz B Wang H Kataria N Cao Q Wagner JE Blazar BR Miller JS Verneris MR 《Journal of immunology (Baltimore, Md. : 1950)》2008,181(7):4507-4515
The natural cytotoxicity receptors (NCRs) NKp30, NKp44, and NKp46 are thought to be NK lineage restricted. Herein we show that IL-15 induces NCR expression on umbilical cord blood (UCB) T cells. NCRs were mainly on CD8(+) and CD56(+) UCB T cells. Only NKp30 was functional as demonstrated by degranulation, IFN-gamma release, redirected killing, and apoptosis. Since NCRs require adaptor proteins for function, the expressions of these adaptors were determined. The adaptors used by NKp30 and NKp46, FcepsilonR1gamma and CD3zeta, were detected in UCB T cells. There was a near absence of DAP12, the adaptor for NKp44, consistent with a hypofunctional state. NKp46 was on significantly fewer UCB T cells, possibly accounting for its lack of function. Adult peripheral blood (PB) T cells showed minimal NCR acquisition after culture with IL-15. Since UCB contains a high frequency of naive T cells, purified naive T cells from adult PB were tested. Although NKp30 was expressed on a small fraction of naive PB T cells, it was nonfunctional. In contrast to UCB, PB T cells lacked FcepsilonR1gamma expression. These results demonstrate differences between UCB and PB T cells regarding NCR expression and function. Such findings challenge the concept that NCRs are NK cell specific. 相似文献
994.
Feichtner S Inführ D Achatz-Straussberger G Schmid D Karnowski A Lamers M Rhyner C Crameri R Achatz G 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(8):5499-5505
The classical allergic reaction starts seconds or minutes after Ag contact and is committed by Abs produced by a special subset of B lymphocytes. These Abs belong to the IgE subclass and are responsible for Type I hyperreactivity reactions. Treatment of allergic diseases with humanized anti-IgE Abs leads primarily to a decrease of serum IgE levels. As a consequence, the number of high-affinity IgE receptors on mast cells and basophils decreases, leading to a lower excitability of the effector cells. The biological mechanism behind anti-IgE therapy remains partly speculative; however, it is likely that these Abs also interact with membrane IgE (mIgE) on B cells and possibly interfere with IgE production. In the present work, we raised a mouse mAb directed exclusively against the extracellular membrane-proximal domain of mIgE. The interaction between the monoclonal anti-mIgE Ab and mIgE induces receptor-mediated apoptosis in vitro. Passive immunization experiments lead to a block of newly synthesized specific IgEs during a parallel application of recombinant Bet v1a, the major birch pollen allergen. The decrease of allergen-specific serum IgE might be related to tolerance-inducing mechanisms stopping mIgE-displaying B cells in their proliferation and differentiation. 相似文献
995.
Immune modulation by the human cytomegalovirus-encoded molecule UL18, a mystery yet to be solved 总被引:1,自引:0,他引:1
Human cytomegalovirus infects human populations at a high frequency worldwide. During the long coevolution of virus and host, a fine balance has developed between viral immune evasion strategies and defense mechanisms of the immune system. Human cytomegalovirus encodes multiple proteins involved in the evasion of immune recognition, among them UL18, a MHC class I homologue. Despite almost 20 years of research and the discovery of a broadly expressed inhibitory receptor for this protein, its function in immune modulation is not clear yet. Recent data suggest that besides inhibitory effects on various immune cells, UL18 may also act as an activating component during CMV infection. In this review, we provide an overview of the biology of UL18 and discuss several attempts to shed light on its function. 相似文献
996.
Two types of acid-degradable nonviral gene carriers, OEI-MK and OEI-BAA, were synthesized by polymerizing oligoethylenimine of 800 Da (OEI800) with the pH-sensitive acetone ketal cross-linker 2,2-bis(N-maleimidoethyloxy) propane (MK) or the 4-methoxybenzaldehyde bisacrylate acetal cross-linker 1,1-bis-(2-acryloyloxy ethoxy)-[4-methoxy-phenyl]methane) (BAA). Corresponding acid-insensitive counterparts (OEI-BM and LT-OEI-HD) were synthesized as well, representing control polymers. Kinetics of hydrolysis were measured and confirmed the pH-dependent degradation profile of the acetal functions, with short half-lives of 3 min at pH 5.0, and 5 h (OEI-MK) or 3.5 h (OEI-BAA) at physiological pH 7.4 and 37 degrees C. DNA polyplexes of a luciferase expression plasmid were tested for gene transfer efficiency and biocompatibility in two cell lines (B16F10 and Neuro2A). Polyplexes with acid-labile polymers showed an improved toxicity profile compared to those made with acid-stable polymer analogues. At low cation/plasmid (c/p) w/w ratios the transfection efficiency of pH-sensitive polymers was slightly reduced, but it became similar or superior to the efficiency of acid-stable polymers at higher c/p ratios. An improved in vivo biocompatibility of the acid-degradable polymers over the stable control polymers was confirmed by liver histology after systemic administration of polymers in Balb/c mice. 相似文献
997.
Yang Qiu Dilip Rajagopalan Susan C. Connor Doris Damian Lei Zhu Amir Handzel Guanghui Hu Arshad Amanullah Steve Bao Nathaniel Woody David MacLean Kwan Lee Dana Vanderwall Terence Ryan 《Metabolomics : Official journal of the Metabolomic Society》2008,4(4):337-346
Recent advances in genomics, metabolomics and proteomics have made it possible to interrogate disease pathophysiology and
drug response on a systems level. The analysis and interpretation of the complex data obtained using these techniques is potentially
fertile but equally challenging. We conducted a small clinical trial to explore the application of metabolomics data in candidate
biomarker discovery. Specifically, serum and urine samples from patients with type 2 diabetes mellitus (T2DM) were profiled
on metabolomics platforms before and after 8 weeks of treatment with one of three commonly used oral antidiabetic agents,
the sulfonyurea glyburide, the biguanide metformin, or the thiazolidinedione rosiglitazone. Multivariate classification techniques
were used to detect serum or urine analytes, obtained at baseline (pre-treatment) that could predict a significant treatment
response after 8 weeks. Using this approach, we identified three analytes, measured at baseline, that were associated with
response to a thiazolidinedione after 8 weeks of treatment. Although larger and longer-term studies are required to validate
any of the candidate biomarkers, pharmacometabolomic profiling, in combination with multivariate classification, is worthy
of further exploration as an adjunct to clinical decision making regarding treatment selection and for patient stratification
within clinical trials.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
998.
999.
Pregnane glycosides from Caralluma adscendens var. fimbriata 总被引:1,自引:0,他引:1
Kunert O Rao VG Babu GS Sujatha P Sivagamy M Anuradha S Rao BV Kumar BR Alex RM Schühly W Kühnelt D Rao GV Rao AV 《化学与生物多样性》2008,5(2):239-250
Eleven novel pregnane glycosides, 2-7 and 9-13, of which four, i.e., 10-13, comprised a new pregnane-type genin exhibiting a hydroxymethylene instead of a Me group at C(19), and the known pregnane glycoside stalagmoside V (8) were isolated from whole plants of Caralluma adscendens var. fimbriata, a native Indian succulent plant. Their structures were elucidated by extensive 2D-NMR spectroscopic studies. 相似文献
1000.