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   15061篇
  免费   1113篇
  国内免费   42篇
耳鼻咽喉   125篇
儿科学   576篇
妇产科学   278篇
基础医学   1829篇
口腔科学   263篇
临床医学   1465篇
内科学   3236篇
皮肤病学   246篇
神经病学   2057篇
特种医学   384篇
外国民族医学   1篇
外科学   2200篇
综合类   153篇
一般理论   7篇
预防医学   1281篇
眼科学   226篇
药学   928篇
中国医学   10篇
肿瘤学   951篇
  2022年   161篇
  2021年   282篇
  2020年   187篇
  2019年   275篇
  2018年   274篇
  2017年   261篇
  2016年   262篇
  2015年   255篇
  2014年   395篇
  2013年   504篇
  2012年   768篇
  2011年   797篇
  2010年   437篇
  2009年   417篇
  2008年   759篇
  2007年   737篇
  2006年   787篇
  2005年   673篇
  2004年   589篇
  2003年   599篇
  2002年   536篇
  2001年   441篇
  2000年   483篇
  1999年   387篇
  1998年   160篇
  1997年   163篇
  1996年   148篇
  1995年   146篇
  1994年   113篇
  1993年   106篇
  1992年   277篇
  1991年   298篇
  1990年   269篇
  1989年   259篇
  1988年   211篇
  1987年   194篇
  1986年   203篇
  1985年   195篇
  1984年   142篇
  1983年   123篇
  1981年   96篇
  1979年   138篇
  1978年   114篇
  1977年   101篇
  1976年   91篇
  1975年   119篇
  1974年   117篇
  1973年   103篇
  1972年   92篇
  1970年   89篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
Paradoxical movement in Parkinson's disease.   总被引:6,自引:0,他引:6  
Patients with Parkinson's disease, although impaired, can sometimes move effectively under visual guidance. The stimuli that often elicit such paradoxical movement are similar to those that relay visual information to the cerebellum. We suggest that many instances of paradoxical movement may be explained by the fact that the pathways relaying those visual stimuli can bypass the damaged basal ganglia and allow an intact cerebellar circuit to be used for visuomotor control.  相似文献   
23.
24.
A cancer-specific self-reporting quality of life questionnaire has been validated. The questionnaire is designed to assess physical functioning, role functioning, cognitive functioning, emotional functioning, social functioning, pain, fatigue, emesis and quality of life by means of multi-item scales, and other disease- and treatment-related symptoms by means of single items. The questionnaire was completed by 126 head and neck cancer patients with a mean age of 67 years. The internal consistency (scale reliability) was satisfactory for all scales but one. Correlations between scales and items assessing the same underlying dimension were also satisfactory. The questionnaire discriminates between patient subgroups and between acute, subacute and late toxicity. Patient compliance was high. The questionnaire provided valuable information, and most of the scales/items functioned well. A few problems were found, especially with the modified visual analogue scales, and minor modifications will be made.  相似文献   
25.
26.
Summary. The increasing spectrum of therapeutic options for tumors of the gastrointestinal tract has resulted in a refinement of the pretherapeutic diagnostic strategies. The diagnostic approach in surgical institutions that are focused on primary surgical resection will therefore be much less sophisticated than in institutions who propose a selective therapeutic approach based on the pretherapeutic tumor stage and prognostic parameters. Pretherapeutic assessment of the depth of tumor infiltration, i. e. the T-category, is essential because most further diagnostic and therapeutic decisions are based on this information. This can today be achieved with a high degree of accuracy by endoscopy and endoscopic ultrasonography. Early T-stages (T1–2) are usually an indication for primary surgical resection and, after exclusion of distant metastases, no further diagnostic studies are required. In patients with locally advanced esophageal, gastric or rectum tumors (T3–4) multimodal therapeutic concepts should be considered. This usually requires additional diagnostic studies. None of the available diagnostic imaging modalities today allows satisfactory pretherapeutic assessment of lymph node metastases. The assumed nodular status should therefore currently not influence therapeutic decisions. Essential is, however, the assessment of distant metastases, since the documentation of distant tumor spread will change the therapeutic approach to a palliative situation. Detailed histologic and molecular-biologic assessment of tumor characteristics is growing in importance. This not only provides therapeutically relevant information regarding tumor grading, but opens the door towards a modern molecular diagnostic approach. It can be expected that in the near future a vast amount of relevant prognostic information can be obtained from endoscopic tumor biopsies, which may soon alter our therapeutic concepts.   相似文献   
27.
In the current era of functional surgery for movement disorders, deep brain stimulation (DBS) of the globus pallidus internus (GPi) is emerging as the favoured intervention for patients with dystonia. Here we report our results in 20 patients with medically intractable dystonia treated with GPi stimulation. The series comprised 14 patients with generalized dystonia and six with spasmodic torticollis. Although comparisons were limited by differences in their respective neurological rating scales, chronic DBS clearly benefited both patient groups. Data conveying the rate of change in neurological function following intervention are also presented, demonstrating the gradual but progressive and sustained nature of improvement following stimulation of the GPi in dystonic patients.  相似文献   
28.
An ideal way to assess the effectiveness of femoropopliteal bypass procedures is to standardize patient- and surgeon-related variables by randomization. Through statistical analysis of multiple factors influencing patency, limb loss, death rate and hospital stay, the authors reviewed retrospectively 136 bypass procedures performed over 5 years. Variables that contributed significantly to the results were: preoperative symptoms (p = 0.037), graft material used (p = 0.016), age of the patient (p = 0.007), adequacy of runoff (p = 0.041) and smoking postoperatively (p = 0.013). Autogenous vein grafts were superior to prosthetic grafts, the cumulative patency at 5 years being 67.5% and 38.2% respectively. The authors emphasize that all patients needing vascular surgery should be advised to stop smoking, since in this study postoperative smoking increased the probability of limb loss and adversely affected the cumulative patency rate by interaction with other variables such as preoperative symptoms, graft material and age.  相似文献   
29.
Primary murine CD4+ and CD8+ T helper (Th) cells provide help for various immune responses by secreting lymphokines which activate effector cells. The purpose of the present study was to investigate the co-stimulatory signals that, together with T cell receptor (TCR) cross-linking, induce phenotypically distinct primary Th cells to secrete IL-2 and proliferate. We isolated highly purified populations of primary CD4+ or CD8+ T cells and stimulated them in vitro with platebound anti-CD3 mAb. TCR cross-linking by anti-CD3 mAb induced both IL-2 receptor expression and responsiveness to exogenous IL-2, but was not sufficient to induce either IL-2 secretion or T cell proliferation. Rather, for both CD4+ and CD8+ primary Th cells, IL-2 secretion and proliferation required both TCR cross-linking and antigen presenting cell (APC)-derived co-stimulatory signals. Based on G-10 adherence and sensitivity to gamma-irradiation, the APC populations able to induce primary CD4+ Th cells and primary CD8+ Th cells to secrete IL-2 were indistinguishable. In addition, we found that either IL-1 or IL-6 could replace the requirement for APC-derived co-stimulatory signals for IL-2 secretion and proliferation by both primary CD4+ Th cells and primary CD8+ Th cells. Thus, the present study has examined and compared the co-stimulatory requirements of rigorously purified subsets of IL-2-secreting primary CD4+ and primary CD8+ T cells.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
30.
Two cases of bilateral malignant glaucoma are presented. In one case the condition developed sequentially in the two eyes; pars plana vitrectomy was eventually needed in the operated eye, whereas the condition responded to medical treatment in the fellow eye. In the second case the two eyes were involved simultaneously nearly 1 year after surgery, and the glaucoma responded to medical treatment.  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