首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7679篇
  免费   638篇
  国内免费   16篇
耳鼻咽喉   37篇
儿科学   199篇
妇产科学   123篇
基础医学   866篇
口腔科学   186篇
临床医学   738篇
内科学   2027篇
皮肤病学   176篇
神经病学   791篇
特种医学   303篇
外科学   1039篇
综合类   135篇
一般理论   28篇
预防医学   659篇
眼科学   277篇
药学   428篇
中国医学   20篇
肿瘤学   301篇
  2023年   51篇
  2022年   62篇
  2021年   132篇
  2020年   94篇
  2019年   153篇
  2018年   172篇
  2017年   140篇
  2016年   118篇
  2015年   130篇
  2014年   167篇
  2013年   273篇
  2012年   362篇
  2011年   416篇
  2010年   241篇
  2009年   194篇
  2008年   369篇
  2007年   367篇
  2006年   395篇
  2005年   351篇
  2004年   294篇
  2003年   331篇
  2002年   248篇
  2001年   181篇
  2000年   185篇
  1999年   180篇
  1998年   72篇
  1997年   65篇
  1996年   57篇
  1995年   72篇
  1994年   70篇
  1993年   54篇
  1992年   171篇
  1991年   143篇
  1990年   127篇
  1989年   138篇
  1988年   132篇
  1987年   140篇
  1986年   133篇
  1985年   122篇
  1984年   109篇
  1983年   66篇
  1979年   92篇
  1978年   77篇
  1977年   58篇
  1975年   49篇
  1974年   70篇
  1973年   61篇
  1972年   62篇
  1971年   59篇
  1966年   50篇
排序方式: 共有8333条查询结果,搜索用时 15 毫秒
111.
112.
113.
Eight subjects with acute functional psychoses receiving unmodified electroconvulsive therapy (ECT) at Ibadan were investigated for occult or subclinical internal tissue damage by serial measurements of eight acute phase reactants. Samples of venous blood were collected from each patient at pretreatment, two within treatment, and one at posttreatment. The acute phase proteins assayed were C-reactive protein (CRP), alpha-2-macroglobulin, ceruloplasmin, factor B, C-4 protein, C-3 protein, transferin, and alpha-1-antitrypsin. Except for CRP, the values of the proteins did not change during treatment. CRP values decreased posttreatment and were not detectable in the last sample in five subjects in whom values had been present pretreatment. Our data do not support fears of occult internal tissue damage during unmodified ECT. The consistent decrease in CRP levels posttreatment when patients no longer exhibited psychotic symptoms could not be explained by type of psychosis, intramuscular injections, or changes in drugs and diet; its significance is not known.  相似文献   
114.
OBJECTIVES.--To identify differences in purified protein derivative (PPD) tuberculin positivity and skin test anergy rates by human immunodeficiency virus (HIV) serostatus, CD4+ lymphocyte count, and other risk factors in intravenous drug users (IVDUs); and to evaluate the appropriateness of the Centers for Disease Control (CDC)--recommended definition for a positive PPD tuberculin skin test result in HIV-1-seropositive patients. DESIGN.--Nested case-control and cross-sectional analyses. SETTING.--Community-based cohort of IVDUs. PATIENTS.--Two hundred sixty HIV-1-seropositive and -seronegative IVDUs, drawn from an unselected cohort, were skin-tested for sensitivity to PPD tuberculin, mumps, and Candida antigens using the Mantoux method. OUTCOME MEASURES.--Positivity to PPD tuberculin, skin test anergy. RESULTS.--Even using the CDC definition of an induration 5 mm or greater in diameter in HIV-1 seropositives, this group was substantially less likely to be PPD tuberculin positive than HIV-1 seronegatives (13.8% vs 25.2%; P = .02). In the HIV-1 seropositives the relative odds of being PPD positive varied depending on whether 10 mm or greater (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.2 to 0.7), 5 mm or greater (OR, 0.5; 95% CI, 0.2 to 0.9), or 2 mm or greater (OR, 0.7; 95% CI, 0.4 to 1.3) was used to define a positive test result. The mean diameter induration in the HIV-1-seropositive group was 2.6 mm vs 5.4 mm in the seronegative group (P = .005). Skin test anergy (to mumps and Candida) appeared to explain the differential. Anergy was substantially higher in the HIV-1 seropositive group and increased as the CD4+ lymphocyte count fell (chi 2 for linear trend, 24.5; P less than .0001). An inverse linear trend for PPD positivity and CD4+ lymphocyte count was also observed (chi 2 for trend, 6.1; P = .01). In multivariate analyses, being 35 years of age or older and being HIV-1 seronegative were significantly associated with PPD positivity, while history of previous police arrest was of borderline significance. Only HIV-1 seropositivity was significantly associated with anergy. CONCLUSIONS.--These findings show that CDC-recommended definition of an induration 5 mm or greater in diameter for PPD tuberculin positivity in HIV-1 seropositives significantly underestimates the "true" infection rate (using the PPD positivity rate in HIV-1 seronegatives as the criterion standard). A definition of 2 mm or greater would appear to be a better cutoff for reducing misclassification in HIV-1 seropositives. This study also confirms that delayed-type hypersensitivity is seriously depressed in HIV-1 seropositive IVDUs and that anergy testing is mandatory to properly assess a negative PPD test result.  相似文献   
115.
White-centered retinal hemorrhages (so-called "Roth spots") were seen in an 11-year-old girl with spontaneous intraventricular and subarachnoid hemorrhage from a ruptured "berry" aneurysm without underlying systemic disorder.  相似文献   
116.
Those afflicted with bipolar disorder often suffer from substantial functional impairment both when in episode and when in remission. This study examined the psychometric properties of a brief assessment of psychosocial functioning, the Range of Impaired Functioning Tool (LIFE-RIFT), among subjects with bipolar I disorder. The study sample consisted of 163 subjects who presented with bipolar I disorder at intake into the NIMH Collaborative Depression Study (CDS). All LIFE-RIFT items come from the Longitudinal Interval Follow-up Evaluation (LIFE). Follow-up data that were used to examine the reliability and validity of the scale come from assessments of psychosocial functioning that were conducted 6, 12, 18, and 24 months after intake into the CDS. The results of factor analyses indicate that the scale items are measures of one construct, psychosocial functioning. The interrater agreement on the scale score was very good with an intraclass correlation coefficient was 0.94. The internal consistency reliability among the scale items was uniformly satisfactory over the four assessment periods, with coefficient alpha ranging from 0.78 to 0.84. Mixed-effect regression analyses showed that during mood episodes subjects were significantly more impaired than those in recovery. In conclusion, the psychometric properties of the LIFE-RIFT were examined in subjects with bipolar I disorder. The analyses from this longitudinal, observational study provide empirical support for the reliability and validity of the scale. The LIFE-RIFT provides a brief, inexpensive alternative to scales currently used to assess psychosocial functioning and can be easily added to semistructured assessments that are used in clinical and treatment outcome studies.  相似文献   
117.
Growth failure is a common presentation of patients with pancreatic insufficient cystic fibrosis. However, full blown kwashiorkor is extremely rare. Cystic fibrosis is also considered to be rare in the South Asian population. This report describes a Sri Lankan infant with cystic fibrosis who presented with clinical features of severe kwashiorkor.  相似文献   
118.
119.
This study has two aims. First, it assesses the implication of husbands' post-traumatic stress disorder (PTSD) and post-concussion syndrome (PC) on their wives' sense of burden and emotional distress. The second aim was to examine the implication of the women's separation-individuation on their adjustment. Sixty women participated in study: 20 women married to war veterans diagnosed as suffering to PTSD, 20 women married to war veterans suffering from PC, and 20 women married to healthy controls. Data was collected using self report questionnaires assessing psychiatric symptomatology, caregiver burden and psychological separation-individuation. Results indicate that women from both research groups suffer from higher levels of burden and distress than controls. The level of separation-individuation was found to be correlated to levels of burden and distress. The complex implications of living with a traumatized spouse are discussed.  相似文献   
120.
Spontaneous rupture of the liver has been described in association with many benign and malignant conditions. We report, to our knowledge, the first case of spontaneous rupture of the liver upon revascularization, requiring total hepatectomy and portocaval shunt, followed by successful retransplantation. Routine pathological examination of the explanted liver failed to reveal the etiology of the rupture. However, electron microscopy demonstrated abnormal collagen in the hepatic arterial wall compatible with a collagen disorder such as Ehlers-Danlos type IV disease. We conclude that the donor liver had a previously undiagnosed collagen disorder. Review of the literature does not preclude the use of livers from donors with a history of connective tissue disorders. Based on our experience one should exercise caution when using livers from such donors. With a history of connective tissue disorder in an immediate family member, further tests should be performed in the donor to rule out a subclinical connective tissue disorder. In addition, a review of all patients reported thus far to have undergone total hepatectomy and portocaval shunt, followed by liver transplantation as a two-stage procedure is presented.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号