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   6832篇
  免费   341篇
  国内免费   32篇
耳鼻咽喉   60篇
儿科学   256篇
妇产科学   134篇
基础医学   885篇
口腔科学   156篇
临床医学   525篇
内科学   1736篇
皮肤病学   104篇
神经病学   705篇
特种医学   201篇
外科学   833篇
综合类   14篇
一般理论   1篇
预防医学   368篇
眼科学   133篇
药学   525篇
中国医学   49篇
肿瘤学   520篇
  2023年   44篇
  2022年   86篇
  2021年   149篇
  2020年   109篇
  2019年   151篇
  2018年   171篇
  2017年   146篇
  2016年   171篇
  2015年   168篇
  2014年   273篇
  2013年   315篇
  2012年   476篇
  2011年   531篇
  2010年   274篇
  2009年   231篇
  2008年   407篇
  2007年   413篇
  2006年   439篇
  2005年   403篇
  2004年   373篇
  2003年   325篇
  2002年   302篇
  2001年   119篇
  2000年   146篇
  1999年   131篇
  1998年   49篇
  1997年   42篇
  1996年   35篇
  1995年   31篇
  1994年   40篇
  1993年   30篇
  1992年   64篇
  1991年   55篇
  1990年   61篇
  1989年   40篇
  1988年   49篇
  1987年   43篇
  1986年   40篇
  1985年   42篇
  1984年   36篇
  1983年   24篇
  1982年   11篇
  1981年   18篇
  1980年   11篇
  1979年   20篇
  1978年   11篇
  1975年   11篇
  1972年   10篇
  1969年   10篇
  1967年   11篇
排序方式: 共有7205条查询结果,搜索用时 15 毫秒
1.
2.
We developed a self-administered questionnaire for screening the most common adult-onset dystonias. It was tested in 90 first-degree relatives of 22 adult-onset dystonia patients, yielding 79% sensitivity and 94% specificity. Simulation of a case-finding procedure based on serial application of the questionnaire and clinical examination of both subjects screening positive and subjects screening negative who had < 8 years of schooling increased sensitivity to 95% and specificity to 100%. This questionnaire may be an important screening resource for familial aggregation studies to be used in the context of a complex case-finding procedure.  相似文献   
3.
Growth hormone (GH) is fundamental for the maintenance of bone mass and metabolism both during childhood and in adulthood. This effect is due to a complex interaction between circulating GH and IGF-I produced peripherally. In vitro data and experimental animal models have clarified many of the regulatory mechanisms underlying the characteristic skeletal changes occurring in acromegaly. This review focuses on the effects of GH excess on bone metabolism and mass in acromegalic patients and, in particular, on the influence of factors such as hypogonadism, gender, age and therapy on bone metabolism and arthropathy.  相似文献   
4.
We report here the antiproteolytic and antihemorrhagic properties of triterpenoid saponin inhibitors, named macrolobin-A and B, from Pentaclethra macroloba, against Bothrops snake venoms. The inhibitors were able to neutralize the hemorrhagic, fibrin(ogen)olytic, and proteolytic activities of class P-I and P-III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. Clotting and fibrinogenolytic activities induced by snake venoms and isolated thrombin-like enzymes were partially inhibited. Furthermore, the potential use of these inhibitors to complement antivenom therapy as an alternative treatment and/or used as molecular models for development of new therapeutical agents in the treatment of snake bite envenomations needs to be evaluated in future studies.  相似文献   
5.
Abstract: Breast conservation surgery is an effective and safe treatment for many breast carcinomas. It may be possible to further limit the extent of resection (or expand the indication for breast conservation) by the application of preoperative chemotherapy and radiotherapy. We explored the feasibility of this in a pilot study.
Seventy-three patients (mean age 48, 63% premenopausal) with confirmed breast cancer, less than 2.5 cm, received chemotherapy (Group A) or chemotherapy plus radiotherapy (Group B) prior to limited resection (tumorectomy). Axillary dissection was always performed. Results: In 6/31 (19%) Group A and 17/42 (40%) Group B patients the tumor was not palpable after preoperative treatment, with complete pathological remission in 1 and 3 cases respectively. Histologic grading, mitosis, cellular alteration, and cellularity evaluations indicated a consistently greater therapeutic effect with chemoradiotherapy than with chemotherapy alone.
In conclusion, radiotherapy appears useful in the preoperative treatment of breast cancer and its use in association with various drug combinations should be further explored.  相似文献   
6.
Summary Thirty-two eligible patients with advanced metastatic breast cancer who had received no more than 1 prior chemotherapy regimen for metastatic disease (16 had received prior doxorubicin) were treated with piroxantrone at a dose of 120 mg/m2 intravenously every 21 days. In the twenty-seven patients evaluable for response, two partial responses were seen. Toxicities observed were primarily hematologic with grade 3 or greater granulocytopenia occurring in 34% of the patients. One patient developed symptomatic congestive heart failure at a total cumulative dose of 960 mg/m2. We conclude that piroxantrone given at this dose and schedule has minimal activity in patients with metastatic breast cancer.  相似文献   
7.
Respiratory infections (RI) are one of the major complaints in children and adolescents, and represent a demanding challenge for the pediatrician. It has been estimated that at least 6% of Italian children younger than 6 yr of age present recurrent respiratory infections (RRI). Children with RRI are not affected by severe alterations of the immune system. RRI represent essentially the consequence of an increased exposure to infectious agents during the first years of life, when immune functions are still largely immature. Several social and environmental factors, such as day-care attendance, family size, air pollution, parental smoking, and home dampness, represent important risk factors for airway diseases and may contribute in various degrees to determine the incidence of RRI. The main problem for the pediatrician is to discriminate normal children with high RI frequency related to an augmented exposure to environmental risk factors from children affected by other underlying pathological conditions (immunological or not), predisposing to infectious diseases. When RRI diagnosis has been formulated, removal of environmental risk factors (i.e. precocious day-care attendance, smoking in the household) must first be suggested.  相似文献   
8.
During revision anterior cruciate ligament (ACL) surgery, femoral interference screws frequently require removal. This may lead to significant tunnel widening and possible graft fixation failure as a result. Solutions include drilling the revision tunnel in a different location, using stacked interference screws, or using bone graft to fill the defect. Autogenous iliac crest graft and allograft are both used, but there are significant comorbidities associated with each. We developed a new technique for harvesting autogenous bone graft that avoids many of the complications associated with other graft sources. By use of the existing surgical incision from the initial harvest of the bone–patellar tendon–bone autograft, bone from the medial tibial metaphyseal safe zone is harvested via an OATS tube harvester (Arthrex, Naples, FL). A bone plug 1 mm larger in size than the femoral defect is harvested and arthroscopically inserted via a press-fit technique. At 3 months after bone grafting, patients undergo revision ACL reconstruction. The proximal tibial metaphysis is a safe bone graft harvest site in revision ACL surgery and offers an effective method for filling large bony defects, allowing anatomic reconstruction of the ACL after bone healing has occurred. Furthermore, it eliminates the problems associated with allograft or use of a remote graft donor site.  相似文献   
9.
10.
Fungal infections in cancer patients: An international autopsy survey   总被引:33,自引:0,他引:33  
In an attempt to estimate the frequency of fungal infections among cancer patients, a survey of autopsy examinations was conducted in multiple institutions in Europe, Japan and Canada. Fungal infections were identified most often in leukemic patients and transplant recipients (25 % each). Fifty-eight percent of fungal infections were caused byCandida spp. and 30 % byAspergillus spp. There was considerable variability in the frequency of fungal infections in different countries. Nevertheless, this study clearly demonstrates that fungal infections represent a common complication in cancer patients, especially in patients with leukemia.  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