全文获取类型
收费全文 | 26221篇 |
免费 | 1733篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 222篇 |
儿科学 | 639篇 |
妇产科学 | 447篇 |
基础医学 | 3853篇 |
口腔科学 | 339篇 |
临床医学 | 2445篇 |
内科学 | 6363篇 |
皮肤病学 | 676篇 |
神经病学 | 2210篇 |
特种医学 | 791篇 |
外国民族医学 | 3篇 |
外科学 | 3790篇 |
综合类 | 270篇 |
一般理论 | 28篇 |
预防医学 | 1950篇 |
眼科学 | 489篇 |
药学 | 1609篇 |
1篇 | |
中国医学 | 56篇 |
肿瘤学 | 1855篇 |
出版年
2022年 | 134篇 |
2021年 | 336篇 |
2020年 | 226篇 |
2019年 | 360篇 |
2018年 | 422篇 |
2017年 | 288篇 |
2016年 | 353篇 |
2015年 | 413篇 |
2014年 | 625篇 |
2013年 | 945篇 |
2012年 | 1402篇 |
2011年 | 1563篇 |
2010年 | 940篇 |
2009年 | 954篇 |
2008年 | 1491篇 |
2007年 | 1653篇 |
2006年 | 1649篇 |
2005年 | 1743篇 |
2004年 | 1601篇 |
2003年 | 1529篇 |
2002年 | 1515篇 |
2001年 | 403篇 |
2000年 | 338篇 |
1999年 | 391篇 |
1998年 | 377篇 |
1997年 | 335篇 |
1996年 | 294篇 |
1995年 | 279篇 |
1994年 | 255篇 |
1993年 | 230篇 |
1992年 | 309篇 |
1991年 | 292篇 |
1990年 | 271篇 |
1989年 | 246篇 |
1988年 | 216篇 |
1987年 | 211篇 |
1986年 | 228篇 |
1985年 | 217篇 |
1984年 | 208篇 |
1983年 | 200篇 |
1982年 | 222篇 |
1981年 | 230篇 |
1980年 | 183篇 |
1979年 | 138篇 |
1978年 | 133篇 |
1977年 | 138篇 |
1976年 | 114篇 |
1975年 | 112篇 |
1974年 | 105篇 |
1971年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
R Goujon E Philibert P Bernard J Normand M Boucherat 《Annales de biologie clinique》1992,50(10-11):675-677
Determination of plasma delta-aminolaevulinic acid levels is of interest for the diagnosis of disorders of heme biosynthesis. We describe a reliable method for the determination of this parameter, based on a modification of the original method of Mauzerall and Granick. Analytical criteria are defined and the reference range used, established using data from 40 subjects, was 0.30 to 1.20 mumol/l. Results in patients with porphyria or lead poisoning and in those treated with haemodialysis or anticonvulsants indicate that this determination could be used principally in the diagnosis and management of acute porphyrias and in the early laboratory diagnosis of lead poisoning. 相似文献
992.
Ljubicic V Miura P Burt M Boudreault L Khogali S Lunde JA Renaud JM Jasmin BJ 《Human molecular genetics》2011,20(17):3478-3493
A therapeutic approach for Duchenne muscular dystrophy (DMD) is to up-regulate utrophin in skeletal muscle in an effort to compensate for the lack of dystrophin. We previously hypothesized that promotion of the slow, oxidative myogenic program, which triggers utrophin up-regulation, can attenuate the dystrophic pathology in mdx animals. Since treatment of healthy mice with the AMP-activated protein kinase (AMPK) activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) enhances oxidative capacity and elicits a fast-to-slow fiber-type transition, we evaluated the effects of chronic AMPK stimulation on skeletal muscle phenotype and utrophin expression in mdx mice. Daily AICAR administration (500 mg/kg/day, 30 days) of 5-7-week-old mdx animals induced an elevation in mitochondrial cytochrome c oxidase enzyme activity, an increase in myosin heavy-chain type IIa-positive fibers and slower twitch contraction kinetics in the fast, glycolytic extensor digitorum longus muscle. Utrophin expression was significantly enhanced in response to AICAR, which occurred coincident with an elevated β-dystroglycan expression along the sarcolemma. These adaptations were associated with an increase in sarcolemmal structural integrity under basal conditions, as well as during damaging eccentric contractions ex vivo. Notably, peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α) and silent information regulator two ortholog 1 protein contents were significantly higher in muscle from mdx mice compared with wild-type littermates and AICAR further increased PGC-1α expression. Our data show that AICAR-evoked muscle plasticity results in beneficial phenotypic adaptations in mdx mice and suggest that the contextually novel application of this compound for muscular dystrophy warrants further study. 相似文献
993.
Ans M W van den Ouweland Peter Elfferich Bernard A Zonnenberg Willem F Arts Tjitske Kleefstra Mark D Nellist Jose M Millan Caroline Withagen-Hermans Anneke J A Maat-Kievit Dicky J J Halley 《European journal of human genetics : EJHG》2011,19(2):157-163
Tuberous sclerosis complex (TSC), an autosomal dominant disorder, is a multisystem disease with manifestations in the central nervous system, kidneys, skin and/or heart. Most TSC patients carry a pathogenic mutation in either TSC1 or TSC2. All types of mutations, including large rearrangements, nonsense, missense and frameshift mutations, have been identified in both genes, although large rearrangements in TSC1 are scarce. In this study, we describe the identification and characterisation of eight large rearrangements in TSC1 using multiplex ligation-dependent probe amplification (MLPA) in a cohort of 327 patients, in whom no pathogenic mutation was identified after sequence analysis of both TSC1 and TSC2 and MLPA analysis of TSC2. In four families, deletions only affecting the non-coding exon 1 were identified. In one case, loss of TSC1 mRNA expression from the affected allele indicated that exon 1 deletions are inactivating mutations. Although the number of TSC patients with large rearrangements of TSC1 is small, these patients tend to have a somewhat milder phenotype compared with the group of patients with small TSC1 mutations. 相似文献
994.
Tessa Crompton Marilyn Mooreu H. Robson MacDonald Bernard Malissen 《European journal of immunology》1994,24(8):1903-1907
Double-negative (DN) thymocyte subsets were examined in mice deficient in the CD3′ chain (ζ −/−). The HSA +CD44−CD25− subset was found to be missing, and DN thymocytes seemed to differentiate directly from HSA+CD25+CD44−cells to double-positive (DP) cells. When fetal thymic ontogeny was examined, we found a marked difference between ζ −/− embryos and heterozygous littermates from embryonic day 17.5, in terms of CD25, CD4 and CD8 expression, and thymus size. The ζ −/− thymocytes failed to down-regulate CD25 and to expand exponentially. The cell cycle status of adult thymocyte subsets indicated that although the HSA +CD25−CD44− subset was missing, the CD25+ DN population contained normal numbers of cycling cells, and the CD25+ DP cells (which were not detectable in normal mice) contained 5–10% cells in G2/M + S. Taken together these data suggest that the CD3′ chain might have a specific role in the control of proliferation of DN thymocytes during T cell development. Our data clearly show that one can dissociate the signal for a CD25+ DN cell to differentiate (which occurs in the absence of CD3′), from a signal to proliferate and from loss of cell surface CD25. 相似文献
995.
Pieter Sipkema Ricky D. Latham Nicolaas Westerhof Bernard J. Rubal David M. Slife 《Annals of biomedical engineering》1990,18(5):491-503
A setup consisting of a high-performance hydraulic pump connected to the ascending part of an isolated aorta, including all
major distal branches, each loaded with calibrated artificial resistors, was developed. The system was used to study total
aortic compliance of the baboon as a function of mean aortic pressure (n=5). The aorta loaded with the resistors was mounted
in a custom-designed sink table, such that it was submersed in physiological saline maintained at 37°C. Mean distending pressure
in the entire aortic compliance from pressure and flow waves generated by the pump. Total aortic compliance as a function
of mean pressure was fitted with a logarithmic function: Ln (Compliance)=A+B * P. The value of A(±SE) was: 1.565±0.319 and
B: −0.020±0.003 (P<0.001). The results were compared with previously published results (also using the same three-element
Windkessel fit) obtained in three of the same animalsin vivo. Thein vivo data were A: 1.095±0.235 and B: −0.019±0.003.In vitro data had a significantly higher value of A thanin vivo (P=0.017), implying a significantly higher aortic compliancein vitro thanin vivo.
Occlusion of the proximal descending aorta was performed at a low distending pressure (55 mm Hg) to determine the proximal
complicance. It was found (n=4) that 46±11% (SD) of the total arterial compliance is to be attributed to the ascending and
proximal descending aorta.
This work was supported in part by Grant RG 86/0066 from the scientific affairs division of Nato. 相似文献
996.
Mary Gwo-Shu Lee Frances T. Yen Yuhong Zhang Bernard E. Bihain 《Molecular and biochemical parasitology》1999,100(2):117-162
The procyclic form of Trypanosoma brucei binds and internalizes bovine high density lipoprotein (HDL) particles in a saturable process; the binding and uptake of 125I-labeled HDL are inhibited by excess unlabeled HDL. We calculated that each procyclic trypanosome exposes ≈1.0×106 binding sites for bovine HDL, with an equilibrium dissociation constant (Kd) of ≈1.26×10−7 M. Uptake of HDL particles does not occur at 4°C. At 28°C, a significant amount of the internalized HDL particles were efficiently degraded through a process that is sensitive to the presence of 50 μM chloroquine. These results suggested that the uptake of HDL particles in procyclic T. brucei may occur via receptor mediated endocytosis, leading to proteolytic degradation of the particles in an acidic and endocytic compartment. 相似文献
997.
998.
CD98hc (SLC3A2) is a key regulator of keratinocyte adhesion 总被引:1,自引:0,他引:1
999.
Usefulness of 2‐[18F]‐fluoro‐2‐deoxy‐d‐glucose–Positron Emission Tomography/Computed Tomography for Staging and Evaluation of Treatment Response in IgG4‐Related Disease: A Retrospective Multicenter Study 下载免费PDF全文
Mikael Ebbo Aurélie Grados Eric Guedj Delphine Gobert Cécile Colavolpe Mohamad Zaidan Agathe Masseau Fanny Bernard Jean‐Marie Berthelot Nathalie Morel François Lifermann Sylvain Palat Julien Haroche Xavier Mariette Bertrand Godeau Emmanuelle Bernit Nathalie Costedoat‐Chalumeau Thomas Papo Mohamed Hamidou Jean‐Robert Harlé Nicolas Schleinitz 《Arthritis care & research》2014,66(1):86-96
1000.