全文获取类型
收费全文 | 2810篇 |
免费 | 264篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 91篇 |
妇产科学 | 49篇 |
基础医学 | 453篇 |
口腔科学 | 36篇 |
临床医学 | 301篇 |
内科学 | 535篇 |
皮肤病学 | 56篇 |
神经病学 | 160篇 |
特种医学 | 171篇 |
外科学 | 345篇 |
综合类 | 172篇 |
一般理论 | 2篇 |
预防医学 | 392篇 |
眼科学 | 31篇 |
药学 | 134篇 |
肿瘤学 | 133篇 |
出版年
2021年 | 48篇 |
2020年 | 24篇 |
2019年 | 29篇 |
2018年 | 45篇 |
2017年 | 28篇 |
2016年 | 37篇 |
2015年 | 52篇 |
2014年 | 65篇 |
2013年 | 96篇 |
2012年 | 116篇 |
2011年 | 98篇 |
2010年 | 62篇 |
2009年 | 87篇 |
2008年 | 120篇 |
2007年 | 119篇 |
2006年 | 117篇 |
2005年 | 95篇 |
2004年 | 96篇 |
2003年 | 102篇 |
2002年 | 96篇 |
2001年 | 93篇 |
2000年 | 108篇 |
1999年 | 89篇 |
1998年 | 69篇 |
1997年 | 62篇 |
1996年 | 82篇 |
1995年 | 36篇 |
1994年 | 51篇 |
1993年 | 33篇 |
1992年 | 63篇 |
1991年 | 70篇 |
1990年 | 54篇 |
1989年 | 62篇 |
1988年 | 68篇 |
1987年 | 61篇 |
1986年 | 45篇 |
1985年 | 53篇 |
1984年 | 31篇 |
1983年 | 27篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 32篇 |
1977年 | 28篇 |
1976年 | 25篇 |
1975年 | 26篇 |
1974年 | 19篇 |
1972年 | 22篇 |
1971年 | 24篇 |
1970年 | 21篇 |
1969年 | 21篇 |
排序方式: 共有3086条查询结果,搜索用时 31 毫秒
101.
102.
Michael J. Hurley Michael J. Jackson Lance A. Smith Sarah Rose Peter Jenner 《Journal of molecular neuroscience : MN》2014,52(2):302-312
Marmosets rendered parkinsonian with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and treated with l-3,4-dihydroxyphenylalanine (l-DOPA) develop dyskinesia, but with differing degrees of severity. To provide insight into the molecular mechanisms responsible for the different level of dyskinesia to manifest in individual animals, proteins in striatum from MPTP-treated marmosets with different levels of l-DOPA-induced dyskinesia were separated by 2-dimensional (2-D) protein electrophoresis. Thirty-five differentially expressed proteins were identified by mass spectrometry and peptide mass fingerprinting, and comparative analysis found 10 were significantly increased and 3 had significantly reduced expression in animals with a high level of dyskinesia when compared to animals with a low incidence of dyskinesia. These proteins belonged to a range of functional classes, for example, molecular chaperones, metabolic enzymes and synaptic structural proteins. The findings of this study provide clues about the molecular mechanisms that cause dyskinesia to manifest and point towards potential novel targets for the development of therapeutic agents to prevent or treat established dyskinesia. 相似文献
103.
Background
Equine neonates have reduced humoral and cell-mediated immune responses compared to adult horses after administration of killed vaccines. As a basis for this study, we hypothesized that newborn foals can mount strong immune responses after vaccination with live Mycobacterium bovis BCG.Methods
Healthy 4-day-old foals (n = 7), 4-month-old foals (n = 7) and adult horses (n = 6) were vaccinated once with live M. bovis BCG. Age-matched animals (n = 5 per group) were used as unvaccinated controls. Relative vaccine-specific immunoglobulin concentrations and whole blood mRNA expression of IFN-γ, IL-4, and IL-10 were measured prior to and 2, 4, 6, and 8 weeks after vaccination. Eight weeks after vaccination, delayed type hypersensitivity (DTH) responses were assessed by measuring the increase in double skin thickness after intradermal injection of purified protein derivative.Results
Both groups of foals and adult horses responded with a significant increase in vaccine-specific total IgG, IgGa, IgGc, IgG(T), and IgM concentrations. In contrast, only adult horses mounted significant IgGb responses. Vaccine-specific concentrations of total IgG and IgGa were significantly higher in adult horses than in 4-day-old foals whereas IgGc responses were significantly higher in 4-day-old foals than in the other two age groups. Adult horses had significantly higher basal IFN-γ and IL-4 mRNA expression than both groups of foals but vaccination with M. bovis BCG did not significantly increase expression of these cytokines, regardless of age group. Immunized horses had significantly higher DTH responses than age-matched unvaccinated controls. DTH responses were significantly greater in both groups of vaccinated foals than in vaccinated adult horses.Conclusion
Despite a naïve immune system, newborn foals have the ability to mount robust antibody and cell-mediated immune responses to M. bovis BCG. 相似文献104.
Noriko K. Steiner Sivanesan DakshanamurthyNicholas Nguyen Carolyn Katovich Hurley 《Human immunology》2014
Natural killer cell stimulatory receptor gene, KIR2DS5, is polymorphic. While KIR2DS5∗002 is most frequently observed, other alleles have also been found. The proteins encoded by these alleles (KIR2DS5∗002–∗009) are expressed at varying levels on the surface of NKL and Jurkat transfectants. Gel electrophoresis of all allelic products showed two isoforms which differ in the extent of maturation of N-linked glycosylation. These isoforms differed in intensity and molecular weight among the allelic products. Site-directed mutagenesis was used to identify polymorphic variation at residues 123 and 157 as key in altering glycosylation and levels of surface expression. 相似文献
105.
Michael J. Hickey Kenneth R. Knight Diana A. Lepore John V. Hurley Wayne A. Morrison 《Microsurgery》1996,17(9):517-523
The aim of this study was to determine whether the administration of free radical antagonists, immediately before and during the early minutes of reperfusion, improves muscle survival 24 hr after a period of ischemia. Rabbit rectus femoris muscles were isolated, made ischemic for 3½ hr and treated with either desferrioxamine (DFX), an Fe3+ chelator, superoxide dismutase and catalase (SOD & CAT), which quench superoxide and hydrogen peroxide, or allopurinol, an inhibitor of xanthine oxidase (XO). After 24 hr reperfusion, muscle viability (±s.e.m.), measured by the nitro blue tetrazolium (NBT) vital staining technique, was 41.6 ± 11.3% for saline-treated ischemic controls, 30.6 ± 7.6% for DFX-treated, 46.7 ± 10.3% for SOD & CAT-treated, and 43.3 ± 9.5% for allopurinol-treated muscles. None of the treated groups differed significantly from the ischemic control group. Tissue myeloperoxidase, ATP and reduced glutathione levels, and plasma lactate dehydrogenase (LDH) and aspartate transaminase (AST) levels were increased by ischemia and reperfusion in all groups, but the changes did not differ between the treatment groups. Levels of XO in the rabbit muscle were determined and found to be very low in both normal and postischemic muscle. As XO is the target enzyme of allopurinol, its absence provides a basis for the lack of effect of this agent. However, it is not clear why DFX and SOD & CAT had no protective effect © 1997 Wiley-Liss, Inc MICROSURGERY 17:517–523 1996 相似文献
106.
Phillip E. Posch Alice E. Hastings Sandra Rosen-Bronson John R. Richert Carolyn Katovich Hurley 《European journal of immunology》1996,26(8):1884-1891
Definition of peptide binding motifs for DR molecules has proven difficult as the peptides that bind to a DR molecule have shown extensive variability at putative motif positions. Recent studies suggest that specific peptide anchor residues (motif positions) and specific DR residues can differ in importance for peptide binding to a DR molecule. To assess further the relevance of individual peptide anchor residues, the binding of serial alanine-substituted analogs of influenza virus hemagglutinin (HA) 306–318 and human myelin basic protein (MBP) 152–165 to a panel of transfected wild-type DR molecules was examined. This analysis included DR molecules from a wide range of allelic families and, unlike most earlier studies, multiple members of single DR allelic families. The data show that different peptide residues serve as critical anchors for binding to different DR molecules. For example, MBP binding to DR(α,β1*0303) required peptide residues F154 (i), R159 (i + 5) and R162 (i + 8). In contrast, MBP binding to DR(α,β1*0102) required peptide residues I153 (i) and L156 (i + 3). More importantly, the combination of critical anchor residues in HA and MBP differed for binding to a single DR molecule [e.g. V309 (i) for HA and I153 (i) and L156 (i + 3) for MBP binding to DR(α,β1*0102)]. Although the location of the binding pocket in each DR molecule compared to the DR (α,β1*0101) crystal is expected to be similar and suggests a common extended DR binding motif, the present results suggest that the relative importance of individual peptide anchor residues and of the corresponding DR binding pockets will differ for each DR/peptide complex. 相似文献
107.
K Nandar LW Ang J Tey L James KM Kyi Win CBE Chee OT Ng JL Cutter YT Wang 《HIV medicine》2018,19(1):59-64
Cross‐matching of records between Singapore's tuberculosis and HIV registries showed that 3.3% of individuals with tuberculosis (TB) were coinfected with HIV (2000?2014), the TB incidence among individuals with HIV infection was 1.65 per 100 person‐years, and 53% of coinfections were diagnosed within 1 month of each other. The findings supported joint prevention programmes for early diagnosis and treatment. 相似文献
108.
Ellis J Steiner N Kosman C Henson V Mitton W Koester R Ng J Hartzman RJ Hurley CK 《Tissue antigens》2000,55(4):369-373
This paper describes seventeen novel HLA-A locus alleles: A*0106, *0235, *0236, *0237, *1105, *2302, *2303, *24032, *2422, *2424, *2503, *2613, *3007, *3203, *3204, *6809 and *6810. All alleles were identified due to unexpected probe reaction patterns during routine SSOP typing. Exons 2 and 3 of these alleles were subsequently characterized by DNA sequencing. The alleles represent a shuffling of sequence motifs, likely by interallelic conversion, expanding the diversity of the HLA system. 相似文献
109.
目的:观察视神经损伤动物模型在损伤后和不同时期视神经管减压后视觉诱发电位的变化,了解创伤性视神经损伤的手术时机与疗效的关系。方法:实验于2005-03/05在解放军南京军区南京总医院动物实验中心完成。①实验分组:30只新西兰白兔随机分为正常对照组、术后2d减压组、术后7d减压组、术后14d减压组、术后不减压组,每组6只。②造模:除正常对照组外,其余各组在视神经孔中塞入一细端为2mm直径的圆锥软硅胶,阻塞视神经孔,造成视神经的挤压伤。③指标检测:采用图形翻转视觉诱发电位检测损伤前、损伤后1h、减压前1h、减压后2周视功能变化,记录NPN曲线主波(P波)的绝对潜伏期、绝对波幅。正常对照组仅采集一组数据作为对照。结果:30只实验动物均进入结果分析。①正常对照组家兔图形翻转视觉诱发电位检查均引出典型NPN波型曲线,视神经挤压伤后1hNPN波形低阔扁平,P波潜伏期延长,波幅降低。②P波潜伏期:术后2d减压组减压后短于减压前[(71.25±8.51),(86.47±14.28)ms,P<0.05];术后7d减压组减压前后比较差异无显著性(P>0.05);术后14d减压组减压后明显长于减压前[(158.73±15.16),(116.35±17.13)ms,P<0.05]。术后2d减压组和术后7d减压组短于术后不减压组(P<0.01)。术后7,14d减压组和术后不减压组明显长于正常对照组(P<0.01)。③P波波幅:术后2d减压组减压后高于减压前[(5.25±0.78),(4.42±0.42)μV,P<0.05]。术后2d减压组减压后低于术后7d减压组、术后14d减压组(P<0.01),术后14d减压组低于术后7d减压组(P<0.05);术后7d减压组、术后14d减压组、术后不减压组低于正常对照组(P<0.01)。结论:神经元继发性损伤是视功能进行性下降的重要原因,视神经减压术有利于减轻视神经间接损伤,较早期(损伤后48h以内)减压可阻止轴突继发性损伤,避免视功能进一步下降,并在一定程度上逆转视功能的损害。 相似文献
110.
Jonathan Mant MA MSc MFPHM Nicholas R. Hicks FRCP MRCGP FFPHM Sue Dopson MA MSc PhD Pauline Hurley BMedSci MB BS MRCOG 《Journal of evaluation in clinical practice》1999,5(1):73-79
To the Editor: There are a large number of studies addressing the impact of continuing medical education (Davis et al. 1995) and clinical guidelines (Grimshaw & Russell 1993) on changing clinical practice, but comparatively little on the impact of purchasers of health care. There is some evidence that financial incentives and penalties can influence practice (Greco & Eisenberg 1993). It has been suggested that purchasers can play an important role in implementing research findings (Haines & Jones 1994). Indeed, the separation of purchasers and providers has been viewed as an opportunity to use knowledge about effectiveness to improve health services (Dunning et al. 1994). We report a study the aim of which was to explore the impact that a specific brief external intervention might have on a detailed aspect of clinical practice: the use of corticosteroids in preterm labour. The intervention was initiated by public health physicians on behalf of a Health Authority. It formed a part of the Getting Research Into Practice (GRIP) initiative in the old Oxford Health Region, UK. The administration of corticosteroids to mothers expected to deliver prematurely reduces neonatal mortality and morbidity (Crowley et al. 1990). The first trial which suggested that corticosteroids were effective in this role was published in 1972, and evidence from 12 trials was assembled in a systematic review published in January 1990 (Crowley et al. 1990). Despite the accumulating evidence, in 1991 many women delivering prematurely in the UK and elsewhere were not receiving corticosteroids (Anon 1992;Donaldson 1992). The apparent failure of obstetricians to make full use of this treatment has been cited as an example of the delayed implementation of research findings that can occur in clinical practice (Haines & Jones 1994; Enkin 1996). 相似文献