全文获取类型
收费全文 | 576篇 |
免费 | 33篇 |
国内免费 | 24篇 |
专业分类
儿科学 | 27篇 |
妇产科学 | 4篇 |
基础医学 | 30篇 |
口腔科学 | 8篇 |
临床医学 | 78篇 |
内科学 | 196篇 |
皮肤病学 | 6篇 |
神经病学 | 22篇 |
特种医学 | 46篇 |
外科学 | 74篇 |
综合类 | 45篇 |
预防医学 | 44篇 |
眼科学 | 6篇 |
药学 | 28篇 |
肿瘤学 | 19篇 |
出版年
2024年 | 1篇 |
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 11篇 |
2016年 | 6篇 |
2015年 | 12篇 |
2014年 | 21篇 |
2013年 | 25篇 |
2012年 | 20篇 |
2011年 | 26篇 |
2010年 | 19篇 |
2009年 | 19篇 |
2008年 | 22篇 |
2007年 | 32篇 |
2006年 | 24篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 25篇 |
2000年 | 16篇 |
1999年 | 21篇 |
1998年 | 25篇 |
1997年 | 20篇 |
1996年 | 24篇 |
1995年 | 12篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 11篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 19篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有633条查询结果,搜索用时 13 毫秒
61.
Ehde DM Kraft GH Chwastiak L Sullivan MD Gibbons LE Bombardier CH Wadhwani R 《General hospital psychiatry》2008,30(1):40-48
OBJECTIVE: The objective of this study was to evaluate the efficacy of paroxetine in treating major depressive disorder (MDD) in persons with multiple sclerosis (MS). METHOD: In this double-blind trial, 42 participants with MS and MDD were randomly assigned to one of two parallel 12-week treatment arms: paroxetine or placebo. The participants started at an initial dose of 10 mg/day paroxetine or placebo, titrated up to 40 mg daily based on symptoms response and side effects. The primary outcome measure was the Hamilton Rating Scale for Depression (HAM-D). Secondary outcomes included fatigue, anxiety and self-reported quality of life. RESULTS: Intent-to-treat analyses revealed that both groups improved from pretreatment to posttreatment. Although the treatment group improved more than the control group on most measures, few differences were statistically significant. For the primary outcome, 57.1% of participants in the treatment arm had at least a 50% reduction in HAM-D score, compared with 40% in the control group (nonsignificant). Treatment effects were greater among the participants who completed the study; 78.6% of completers had a treatment response compared with 42.1% of controls (P=.073). CONCLUSION: Although paroxetine may not be efficacious for all persons with MS and MDD, it appears to benefit some individuals. 相似文献
62.
Background
In the adult abdomen of Drosophila, the shafts of mechanosensory bristles point consistently from anterior to posterior. This is an example of planar cell polarity (PCP); some genes responsible for PCP have been identified. Each adult bristle is made by a clone of four cells, including the neuron that innervates it, but little is known as to how far the formation or positions of these cells depends on PCP. The neurons include a single dendrite and an axon; it is not known whether the orientation of these processes is influenced by PCP.Results
We describe the development of the abdominal mechanosensory bristles in detail. The division of the precursor cell gives two daughters, one (pIIa) divides to give rise to the bristle shaft and socket cell and the other (pIIb) generates the neuron, the sheath and the fifth cell. Although the bristles and their associated shaft and socket cells are consistently oriented, the positioning and behaviour of the neuron, the sheath and the fifth cell, as well as the orientation of the axons and the dendritic paths, depend on location. For example, in the anterior zone of the segment, the axons grow posteriorly, while in the posterior zone, they grow anteriorly. Manipulating the PCP genes can reverse bristle orientation, change the path taken by the dendrite and the position of the cell body of the neuron. However, the paths taken by the axon are not affected.Conclusion
PCP genes, such as starry night and dachsous orient the bristles and position the neuronal cell body and affect the shape of the dendrites. However, these PCP genes do not appear to change the paths followed by the sensory axons, which must, therefore, be polarised by other factors.63.
64.
65.
MD Ronghe ABM Foot R Martin M Ashworth CG Steward 《Acta paediatrica (Oslo, Norway : 1992)》2001,90(5):584-586
Barth syndrome is a metabolic disease characterized by infantile cardiomyopathy, neutropenia and organic aciduria. We report disease evolution in one of the first affected boys to undergo successful cardiac transplantation. CONCLUSION: Although cardiac status stabilized, he developed disabling skeletal myopathy, protracted lymphopenia and--5 y after transplant--fatal Epstein Barr (EBV)-negative T-cell non-Hodgkin's lymphoma. 相似文献
66.
To our knowledge this study of our first consecutive 1,000 patients treated with the Siemens Lithostar device is the largest prospective series reported to date. Treatment results were determined at 3, 12 and 24 months after completion of therapy. The results at 3 months are presented. Complete followup data were available on 801 patients: 674 with renal and 127 with ureteral calculi. Results were analyzed according to stone size, location and number. The average number of shocks per treatment was 3,804 and the retreatment rate was 18.6%. At 3 months the stone-free rate was determined by a plain film of the kidneys, ureters and bladder and plain tomograms for renal calculi, and by an excretory urogram for ureteral calculi. The stone-free rate was 52% for renal and 76% for ureteral calculi. The overall stone-free rate for all calculi was 55.7%. Success rate, defined as stone-free or asymptomatic residual fragments measuring 4 mm. or less, was 72% for renal and 83% for ureteral calculi. The overall success rate for all calculi was 73.9%. 相似文献
67.
Buysmann S; Bemelman FJ; Schellekens PT; van Kooyk Y; Figdor CG; ten Berge IJ 《Blood》1996,87(1):404-411
We investigated the mechanism by which antihuman CD3 monoclonal antibodies of the isotypes IgG2a (eg, OKT3) and IgA (eg, IXA) can induce the rapid disappearance of virtually all circulating T lymphocytes. We hypothesize that upregulation of adhesion molecules on the lymphocyte membrane contributes to this effect. However, this hypothesis is difficult to test, because of the inherent lymphocytopenia and/or shifts in lymphocyte populations between intra and extra-vascular compartments. Therefore, studies in vitro were performed, as well. Analysis of peripheral blood lymphocytes isolated at several times after addition of OKT3 or IXA to whole blood of healthy individuals showed an immediate increase in the proportion of T cells expressing NKI-L16, an activation epitope on CD11a/CD18. Likewise, an increase in CD11b/CD18 expression occurred. In parallel experiments, a transiently increased adhesion of T cells to endothelial cell monolayers was observed. This adhesion could be completely blocked by anti-CD18 or anti-CD11a monoclonal antibodies and only partly by an anti-CD11b antibody. Our data indicate that upregulation of activation epitopes of CD11a/CD18, as well as increased expression of CD11b/CD18 on T lymphocytes, may result in increased adhesion of these cells to intercellular adhesion molecule-1 (ICAM-1) and ICAM-2 on vascular endothelium. This phenomenon may, at least, partly explain the rapidly occurring peripheral lymphocytopenia observed in vivo. 相似文献
68.
Cost-effectiveness of inpatient and intensive outpatient treatment of rheumatoid arthritis. A randomized, controlled trial 总被引:1,自引:0,他引:1
A Helewa C Bombardier C H Goldsmith B Menchions H A Smythe 《Arthritis and rheumatism》1989,32(12):1505-1514
Women with active rheumatoid arthritis who were judged to be in need of hospitalization were assigned at random to receive inpatient therapy (n = 35) or intensive outpatient therapy (n = 36). All relevant costs of treatment were measured. At 19 weeks, clinical outcomes, as summarized in a pooled index, were significantly better in the inpatient group (pooled index units: inpatient 0.72, outpatient 0.25; F[1,69] = 10.9, P = 0.002). Inpatient therapy produced a sustained three-fold increase in efficacy, at a 2.5-fold increase in cost to society. 相似文献
69.
Clinical utility and specificity of anticardiolipin antibodies. 总被引:1,自引:0,他引:1
C A Soloninka C A Laskin J Wither D Wong C Bombardier J Raboud 《The Journal of rheumatology》1991,18(12):1849-1855
Established solid phase assays for anticardiolipin antibodies (aCL) are often characterized by high levels of nonspecific binding. As a result, only very high levels of aCL have been reported to be associated with a variety of clinical conditions including systemic lupus erythematosus (SLE), recurrent intravascular thrombosis and unexplained recurrent fetal loss. We have developed an ELISA replacing direct evaporation of soluble cardiolipin with cardiolipin micelles in physiological saline as the antigen binding step in the assay. Levels of IgG aCL were detected in various sera at dilutions of 1/100 to 1/3200, showing improved assay sensitivity. Assay specificity was determined using double stranded DNA and ovalbumin as irrelevant binding antigens and no crossreactivity was found. The controversial use of Tween 20 in the assay was investigated and results showed it decreases nonspecific binding without interfering in antibody detection. This assay has enabled us to identify differences in the prevalence and level of aCL antibodies in sera from healthy nonpregnant controls (0/25 positive), healthy pregnant controls (5/47 positive for IgG and 8/47 positive for IgM) and from women with unexplained recurrent fetal loss (16/62 and 14/62 positive, respectively). We support the observation that aCL are not normally distributed, and therefore nonparametric methods of statistical analysis are necessary to determine population prevalence. We confirm that aCL IgM are a relatively nonspecific finding, and extreme caution must be used in basing any clinical decisions on the presence of this antibody alone. 相似文献
70.
Beaton DE Bombardier C Katz JN Wright JG Wells G Boers M Strand V Shea B 《The Journal of rheumatology》2001,28(2):400-405
The purpose of this paper is to describe a classification system for studies of responsiveness that was designed to help organize these studies, and identify those with the potential to provide information on minimal clinically important difference (MCID). We developed a 3 dimensional cube into which studies of responsiveness can be categorized based on their evaluation of 3 attributes: 1. individual or group setting; 2. which scores are contrasted; and 3. the type of change or difference being assessed. We present and discuss examples of studies that fit into categories in the classification cube. This classification system helps to focus attention on whether the literature is able to provide information on the specific type of change a person is interested in. It reinforces that the ability of an instrument to detect a certain category of discrimination within the cube does not mean it will necessarily be responsive to another category. The cube has been shown here as a means to separate out studies that address important change. These studies can then be examined as the source of information on MCID. 相似文献