全文获取类型
收费全文 | 3174篇 |
免费 | 272篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 117篇 |
妇产科学 | 76篇 |
基础医学 | 379篇 |
口腔科学 | 130篇 |
临床医学 | 338篇 |
内科学 | 821篇 |
皮肤病学 | 64篇 |
神经病学 | 133篇 |
特种医学 | 410篇 |
外科学 | 357篇 |
综合类 | 108篇 |
预防医学 | 170篇 |
眼科学 | 40篇 |
药学 | 156篇 |
中国医学 | 4篇 |
肿瘤学 | 166篇 |
出版年
2023年 | 19篇 |
2022年 | 25篇 |
2021年 | 48篇 |
2020年 | 33篇 |
2019年 | 27篇 |
2018年 | 59篇 |
2017年 | 61篇 |
2016年 | 63篇 |
2015年 | 48篇 |
2014年 | 107篇 |
2013年 | 121篇 |
2012年 | 109篇 |
2011年 | 123篇 |
2010年 | 119篇 |
2009年 | 129篇 |
2008年 | 108篇 |
2007年 | 165篇 |
2006年 | 127篇 |
2005年 | 118篇 |
2004年 | 120篇 |
2003年 | 101篇 |
2002年 | 89篇 |
2001年 | 88篇 |
2000年 | 97篇 |
1999年 | 99篇 |
1998年 | 113篇 |
1997年 | 92篇 |
1996年 | 80篇 |
1995年 | 68篇 |
1994年 | 61篇 |
1993年 | 57篇 |
1992年 | 65篇 |
1991年 | 70篇 |
1990年 | 60篇 |
1989年 | 66篇 |
1988年 | 58篇 |
1987年 | 58篇 |
1986年 | 59篇 |
1985年 | 52篇 |
1984年 | 33篇 |
1983年 | 32篇 |
1982年 | 22篇 |
1981年 | 12篇 |
1980年 | 16篇 |
1979年 | 21篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 25篇 |
1975年 | 19篇 |
1974年 | 14篇 |
排序方式: 共有3495条查询结果,搜索用时 15 毫秒
71.
Pre-B cells and other possible precursor lymphoid cell lines derived from patients with X-linked agammaglobulinemia 总被引:14,自引:6,他引:14 下载免费PDF全文
SM Fu JN Hurley JM McCune HG Kunkel RA Good 《The Journal of experimental medicine》1980,152(6):1519-1526
A group of unique Epstein-Barr virus-containing cell lines was derived from the bone marrow of three patients with X-linked agammaglobulinemia. Efforts to obtain cell lines from the peripheral blood of these patients were uniformly unsuccessful. Immunofluorescence analyses as well as biosynthetic studies with [(35)S]methionine indicated unusual patterns of Ig synthesis in many of these bone marrow derived lines. Seven of the lines were of particular interest in that two produced no Ig of any type; two others showed no Ig by fluorescence but small amounts by [(35)S]methionine labeling; one expressed only cytoplasmic μ chains without any evidence of light chain synthesis, and two produced primarily μ chains with only slight amounts of light chains. One of the lines without membrane or cytoplasmic Ig studied in detail grew like a typical lymphoid line and was carried in intermittent culture over a period of 2 yr without Ig expression. One line grew quite differently and resembled the round cell type described previously, which has been obtained from a variety of sources. The cell line with cytoplasmic μ chains and no light-chain expression had the characteristic properties of pre-B cells. Three normal type Ig-producing cell lines also were obtained from the patients. The accumulated evidence obtained in the present study indicates that these unusual cell lines represent normal precursor cells of the B-cell lineage; these grew out in these cases because of the virtual absence of mature B cells that ordinarily overgrow the culture system. However, the possibility that in certain instances they reflect abnormal Ig synthesis characteristic of the disease has not been ruled out. 相似文献
72.
73.
RK Verma I Bhattacharyya A Sevilla I Lieberman S Pola M Nair SM Wallet I Aukhil L Kesavalu 《Oral diseases》2010,16(7):686-695
Oral Diseases (2010) 16 , 686–695 Objective: This study was designed to test the hypothesis that periodontal pathogens Tannerella forsythia and Porphyromonas gingivalis are synergistic in terms of virulence potential using a model of mixed‐microbial infection in rats. Materials and methods: Three groups of rats were infected orally with either T. forsythia or P. gingivalis in mono‐bacterial infections or as mixed‐microbial infections for 12 weeks and a sham‐infected group were used as a control. This study examined bacterial infection, inflammation, immunity, and alveolar bone loss changes with disease progression. Results: Tannerella forsythia and P. gingivalis genomic DNA was detected in microbial samples from infected rats by PCR indicating their colonization in the rat oral cavity. Primary infection induced significantly high IgG, IgG2b, IgG1, and IgG2a antibody levels indicating activation of mixed Th1 and Th2 immune responses. Rats infected with the mixed‐microbial consortium exhibited significantly increased palatal horizontal and interproximal alveolar bone loss. Histological examinations indicated significant hyperplasia of the gingival epithelium with moderate inflammatory infiltration and apical migration of junctional epithelium. The results observed differ compared to uninfected controls. Conclusion: Our results indicated that T. forsythia and P. gingivalis exhibit virulence, but not virulence synergy, resulting in the immuno‐inflammatory responses and lack of humoral immune protection during periodontitis in rats. 相似文献
74.
75.
Fabien Picard MD MSc Robert Avram MD MSc Guillaume Marquis‐Gravel MD MSc Victor‐Xavier Tadros MD MSc Hung Q. Ly MD SM Quentin de Hemptinne MD Jean‐François Dorval MD Philippe L. L'allier MD Jean‐François Tanguay MD 《Journal of interventional cardiology》2017,30(6):558-563
Aims
The management of patients with in‐stent restenosis (ISR) is still a major clinical challenge even in the era of drug‐eluting stents (DES). Recent studies have demonstrated acceptable clinical outcomes for the everolimus‐eluting bioresorbable vascular scaffold (BVS) ABSORB? in patients with stable coronary artery disease but data are scarce on its use in patients with ISR. We report the long‐term results of our preliminary experience with this novel approach at our institution.Methods and Results
We investigated the safety and efficacy of BVS implantation to treat ISR. 34 consecutive patients (37 lesions) underwent PCI for ISR with BVS implantation between May 2013 and June 2015 at our institution and were included in the current analysis. Follow‐up was available in 91.9% of the patients. Mean follow‐up period was 801.9 ± 179 days. One patient had definite scaffold thrombosis (ScT) 2 months after stent implantation which was treated with DES. Five patients (six lesions) experienced target lesion revascularization (TLR). The composite endpoint rate of TLR, ScT, myocardial infarction, and death occured in 6/37 lesions at follow‐up (16.2%).Conclusions
These real‐world data using BVS in patients with ISR demonstrates that ISR treatment with ABSORB? BVS is feasible but could have slightly higher target lesion failure rates as compared to DES. This proof of concept could be hypothesis‐generating for larger randomized controlled studies.76.
Practice patterns and clinical outcomes among non‐ST‐segment elevation acute coronary syndrome (NSTE‐ACS) patients presenting to primary and tertiary hospitals: Insights from the EARLY glycoprotein IIb/IIIa inhibition in NSTE‐ACS (EARLY‐ACS) trial 下载免费PDF全文
Olga Toleva MD Cynthia M. Westerhout PhD Manohara P.J. Senaratne MBBS PhD Christoph Bode MD Magnus Lindroos MD PhD Vitaly A. Sulimov MD PhD Gilles Montalescot MD L. Kristin Newby MD MHS Robert P. Giugliano MD SM Frans Van de Werf MD PhD Paul W. Armstrong MD 《Catheterization and cardiovascular interventions》2014,84(6):934-942
77.
The P-selectin gene is highly polymorphic: reduced frequency of the Pro715 allele carriers in patients with myocardial infarction 总被引:10,自引:3,他引:10
Herrmann SM; Ricard S; Nicaud V; Mallet C; Evans A; Ruidavets JB; Arveiler D; Luc G; Cambien F 《Human molecular genetics》1998,7(8):1277-1284
P-selectin is an adhesion molecule, expressed at the surface of activated
cells, that mediates the interaction of activated endothelial cells or
platelets with leukocytes. P-selectin expression is increased in
atherosclerotic plaques, and high plasma levels of this molecule have been
observed in patients with unstable angina. We investigated the P-selectin
gene as a possible candidate for myocardial infarction (MI). The P-selectin
gene is situated on chromosome 1q21-q24, spans >50 kb and contains 17
exons. The sequences of the 5'-flanking region and exons of 40 alleles from
patients with MI were screened for polymorphisms using polymerase chain
reaction/single-strand conformation polymorphism (PCR-SSCP) and sequencing.
Thirteen polymorphisms were identified: five in the 5'-flanking and eight
in the exonic sequences. Four polymorphisms (Ser290Asn, Asn562Asp,
Leu599Val and Thr715Pro) predicted a change in the amino acid sequence of
the P- selectin protein. All P-selectin polymorphisms as well as a common
E- selectin polymorphism, Ser128Arg which has been reported as being
associated with an increased risk of premature coronary heart disease
(CHD), and is in tight linkage disequilibrium with several P-selectin
polymorphisms, were investigated in 647 patients with MI and 758 control
subjects from four regions of France and Northern Ireland (the ECTIM
study). The entire set of P-selectin polymorphisms provided a
heterozygosity of 91%. The polymorphisms were tightly associated with one
another and displayed patterns of linkage disequilibrium suggesting the
existence of highly conserved ancestral haplotypes. The five polymorphisms
in the 5'-flanking region of the gene were unrelated to MI or any relevant
phenotype measured in the ECTIM study. We inferred that the four missense
variants identified in the coding region predicted eight common forms of
the P-selectin protein. The Pro715 allele which characterizes one of these
forms was less frequent in France than in Northern Ireland ( P < 0.002)
and in cases than in controls ( P < 0.002; P < 0.02 after correction
for the number of tests). We conclude that the P-selectin gene is highly
polymorphic and hypothesize that the Pro715 variant may be protective for
MI. Whether this variant affects the properties of the P-selectin protein
in a way which is compatible with this hypothesis needs to be checked
experimentally.
相似文献
78.
Plasmid DNA encoding transforming growth factor-beta1 suppresses chronic disease in a streptococcal cell wall-induced arthritis model. 总被引:6,自引:0,他引:6 下载免费PDF全文
X Y Song M Gu W W Jin D M Klinman S M Wahl 《The Journal of clinical investigation》1998,101(12):2615-2621
Transforming growth factor beta is a potent immunomodulator with both pro- and antiinflammatory activities. Based on its immunosuppressive actions, exogenous TGF-beta has been shown to inhibit autoimmune and chronic inflammatory diseases. To further explore the potential therapeutic role of TGF-beta, we administered a plasmid DNA encoding human TGF-beta1 intramuscularly to rats with streptococcal cell wall-induced arthritis. A single dose of 300 microg plasmid DNA encoding TGF-beta1, but not vector DNA, administered at the peak of the acute phase profoundly suppressed the subsequent evolution of chronic erosive disease typified by disabling joint swelling and deformity (articular index = 8.17+/-0. 17 vs. 1.25+/-0.76, n = 6, day 26, P < 0.01). Moreover, delivery of the TGF-beta1 DNA even as the chronic phase commenced virtually eliminated subsequent inflammation and arthritis. Both radiologic and histopathologic as well as molecular evidence supported the marked inhibitory effect of TGF-beta1 DNA on synovial pathology, with decreases in the inflammatory cell infiltration, pannus formation, cartilage and bone destruction, and the expression of proinflammatory cytokines that characterize this model. Increases in TGF-beta1 protein were detected in the circulation of TGF-beta1 DNA-treated animals, consistent with the observed therapeutic effects being TGF-beta1 dependent. These observations provide the first evidence that gene transfer of plasmid DNA encoding TGF-beta1 provides a mechanism to deliver this potent cytokine that effectively suppresses ongoing inflammatory pathology in arthritis. 相似文献
79.
Ronald Allen Coss Christopher W. Storck Tiffany C. Wells Kari A. Kulp Miriam Wahl Dennis B. Leeper 《International journal of hyperthermia》2014,30(1):75-78
Purpose: This study tested the ability of lonidamine (LND), a clinically applicable inhibitor of monocarboxylate transporters (MCT), to thermally sensitise human melanoma cells cultured at a tumour-like extracellular pH (pHe) 6.7.Materials and methods: Human melanoma DB-1 cells cultured at pHe 6.7 and pHe 7.3 were exposed to 150?µM LND for 3?h, beginning 1?h prior to heating at 42?°C (2?h). Intracellular pH (pHi) was determined using 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) and whole spectrum analysis. Levels of heat shock proteins (HSPs) were determined by immunoblot analysis. Cell survival was determined by colony formation.Results: Treatment with LND at pHe 6.7 reduced pHi to 6.30?±?0.21, reduced thermal induction of HSPs, and sensitised cells growing at pHe 6.7 to 42?°C. When LND was combined with an acute acidification from pHe 6.7 to pHe 6.5, pHi was reduced to 6.09?±?0.26, and additional sensitisation was observed. LND had negligible effects on cells cultured at pH 7.3.Conclusions: The results show that LND can reduce pHi in human melanoma cells cultured at a tumour-like low pHe so that the 42?°C induction of HSPs are abrogated and the cells are sensitised to thermal therapy. Cells cultured at a normal tissue-like pHe 7.3 were not sensitised to 42?°C by LND. These findings support the strategy that human melanoma cells growing in an acidic environment can be sensitised to thermal therapy in vivo by exposure to an MCT inhibitor such as LND. 相似文献
80.