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   521篇
  免费   58篇
  国内免费   6篇
耳鼻咽喉   13篇
儿科学   51篇
妇产科学   6篇
基础医学   81篇
口腔科学   27篇
临床医学   53篇
内科学   113篇
皮肤病学   20篇
神经病学   18篇
特种医学   81篇
外科学   40篇
综合类   17篇
预防医学   11篇
眼科学   1篇
药学   31篇
肿瘤学   22篇
  2022年   4篇
  2021年   2篇
  2020年   2篇
  2019年   6篇
  2018年   8篇
  2017年   4篇
  2016年   9篇
  2015年   12篇
  2014年   15篇
  2013年   21篇
  2012年   13篇
  2011年   12篇
  2010年   39篇
  2009年   26篇
  2008年   19篇
  2007年   16篇
  2006年   14篇
  2005年   16篇
  2004年   13篇
  2003年   14篇
  2002年   6篇
  2001年   7篇
  2000年   4篇
  1999年   10篇
  1998年   30篇
  1997年   34篇
  1996年   33篇
  1995年   31篇
  1994年   19篇
  1993年   17篇
  1992年   10篇
  1991年   6篇
  1989年   15篇
  1988年   15篇
  1987年   16篇
  1986年   10篇
  1985年   8篇
  1984年   4篇
  1983年   3篇
  1982年   6篇
  1981年   12篇
  1980年   4篇
  1979年   2篇
  1978年   1篇
  1977年   5篇
  1976年   5篇
  1973年   2篇
  1972年   1篇
  1971年   1篇
  1954年   1篇
排序方式: 共有585条查询结果,搜索用时 46 毫秒
11.
The human T-lymphotropic virus type III (HTLV-III) is the primary cause of the acquired immunodeficiency syndrome (AIDS) and related disorders (ARC). Prior studies have reported that nearly all symptomatic patients with AIDS or ARC manifest antibody to HTLV-III. This observation has engendered efforts to screen for HTLV-III, especially prior to blood donation, with assays for antibody to HTLV-III. We report the first two cases, one with AIDS and one with ARC, that are HTLV-III virus positive but antibody negative. Accurate diagnosis of HTLV-III infection in some cases may require direct virus culture or tests for antigen. In addition, lack of HTLV-III antibody may indicate an atypical clinical course of AIDS.  相似文献   
12.
Since December 1999 to November 2003, we treated 68 patients with pectus excavatum using the Nuss minimally invasive procedure. Their ages were between 6 and 24 years old, with a mean of 12 years. Average Haller index was 4.1. Lateral stabilisers were used in all the cases, in 28% of them, two stabilisers were used. Mean operative time was 70 minutes (range 40 to 120). A thoracic epidural catheter was used for postoperative analgesia in 87% of the cases, with a mean duration of 3 days. The most frequent early complication was residual pneumothorax, which resolved spontaneously in 24% of the cases. The average hospital stay was 5.7 days. 93% of patients had excellent, very good or good results, in 5% of the cases the results were fair, and 2% had poor results due to thoracic asimetry and/or sternal rotation. The Nuss minimally invasive procedure is a useful method for treatment of pectus excavatum's patients.  相似文献   
13.
14.
15.
Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant.  相似文献   
16.
This study examined the efficacy of Collaborative & Proactive Solutions (CPS) in treating oppositional defiant disorder (ODD) in youth by comparing this novel treatment to Parent Management Training (PMT), a well-established treatment, and a waitlist control (WLC) group. One hundred thirty-four youth (ages 7–14, 61.9% male, 83.6% White) who fulfilled Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for ODD were randomized to CPS, PMT, or WLC groups. ODD was assessed with semistructured diagnostic interviews, clinical global severity and improvement ratings, and parent report measures. Assessments were completed pretreatment, posttreatment, and at 6 months following treatment. Responder and remitter analyses were undertaken using intent-to-treat mixed-models analyses. Chronological age, gender, and socioeconomic status as well as the presence of comorbid attention deficit/hyperactivity and anxiety disorders were examined as predictors of treatment outcome. Both treatment conditions were superior to the WLC condition but did not differ from one another in either our responder or remitter analyses. Approximately 50% of youth in both active treatments were diagnosis free and were judged to be much or very much improved at posttreatment, compared to 0% in the waitlist condition. Younger age and presence of an anxiety disorder predicted better treatment outcomes for both PMT and CPS. Treatment gains were maintained at 6-month follow-up. CPS proved to be equivalent to PMT and can be considered an evidence-based, alternative treatment for youth with ODD and their families.  相似文献   
17.
A pilot study was designed to examine whether the outcome of embryo transfer in women with a hydrosalpinx might be improved by surgical drainage of the hydrosalpinx at the time of oocyte collection for in- vitro fertilization treatment. A comparative, controlled but retrospective analysis of the results was performed of all women with infective tubal damage aged <40 years old, who had ovulatory cycles, a normal uterus and a partner with normal spermatozoa. A standardized treatment regimen was used. A maximum of three embryos were transferred. Hydrosalpinx was defined by prior hysterosalpingography and/or laparoscopy with transcervical dye injection. A total of 237 embryo transfer cycles in women with hydrosalpinges (tubal distension not visible in 151, visible but not drained in 30 and drained in 56) were compared with 705 embryo transfer cycles in women with tubal disease but no hydrosalpinx. Results were analysed in the first three cycles but also separately in the first cycle to check for bias. Success rates were higher in the first cycle, but did not significantly influence overall differences. Implantation rates were significantly reduced overall in the hydrosalpinx group (8.0 versus 13.2% for controls; P < 0.001), being 8.3% (P < 0.01) in the subgroup without evident tubal distension and 7.5% (not significant) in the drained hydrosalpinx group. This study shows that tubal damage with distal occlusion is associated with a marked reduction in embryo implantation, even in the absence of obvious fluid distension. Surgical drainage of distended hydrosalpinges appears to offer no benefit.   相似文献   
18.
While constructing a cDNA library of human embryos, we have isolated a clone homologous to jumonji, a mouse gene required for neural tube formation. We have determined the complete coding sequence of the human homologue (JMJ) and deduced the amino acid sequence of the putative protein. We show here that human and mouse jumonji putative proteins are homologous and present 90% identity. During human embryogenesis, JMJ mRNAs are predominantly expressed in neurons and particularly in dorsal root ganglion cells. They are also expressed in neurons of human adult cerebral cortex. In view of these observations, we propose JMJ as a candidate gene for developmental defects of the central nervous system in the human. The human JMJ gene maps at position 6p24-6p23.   相似文献   
19.
20.

Background

Access to pediatric antiretroviral formulations is increasing in resource-limited countries, however adult FDCs are still commonly used by antiretroviral therapy (ART) programs.

Objective

To describe long-term effectiveness of using adult FDC of d4T+3TC+NVP (Triomune) in children for HIV treatment.

Methods

Clinical, immunologic, and virologic outcomes of HIV-infected ART-naïve children aged six months to 12 years, were evaluated up to 96 weeks post-ART initiation.

Results

From March 2004 to June 2006, 104 children were followed with a median age of 5.4 years, median CD4 cell percent and HIV-1 RNA were 11.0% (IQR 6.7–13.9) and 348,846copies/mL (IQR 160,941–681,313) respectively at baseline. Using Kaplan-Meir estimates, 75% of children had undetectable viral loads (<400copies/mL) at 96weeks of ART. Children with a baseline CD4 cell percent >15% were 3 times more likely to achieve viral load <400copies/mL than those with baseline CD4 cell percent <5% after adjusting for baseline age {aHR = 3.03 (1.10–8.32), p=0.03}; no difference was found among those with CD4 cell percent >5–14.9% and <5%.

Conclusion

Treatment with generic adult FDC for HIV-infected Ugandan children led to sustained clinical, immunologic and virologic response during 96 weeks of ART. Early initiation of ART is key to achieving virological success.  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