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   530141篇
  免费   27653篇
  国内免费   495篇
耳鼻咽喉   6681篇
儿科学   16924篇
妇产科学   12539篇
基础医学   92645篇
口腔科学   12347篇
临床医学   48505篇
内科学   95445篇
皮肤病学   11871篇
神经病学   34073篇
特种医学   19757篇
外国民族医学   53篇
外科学   78070篇
综合类   7610篇
现状与发展   2篇
一般理论   107篇
预防医学   38534篇
眼科学   11940篇
药学   41414篇
  1篇
中国医学   1127篇
肿瘤学   28644篇
  2021年   3896篇
  2018年   5738篇
  2017年   4129篇
  2016年   4877篇
  2015年   5366篇
  2014年   7117篇
  2013年   10505篇
  2012年   15579篇
  2011年   17398篇
  2010年   9961篇
  2009年   8824篇
  2008年   15722篇
  2007年   17451篇
  2006年   16953篇
  2005年   16268篇
  2004年   15888篇
  2003年   15275篇
  2002年   14788篇
  2001年   22433篇
  2000年   22975篇
  1999年   18919篇
  1998年   5232篇
  1997年   4365篇
  1996年   4397篇
  1995年   4124篇
  1992年   14415篇
  1991年   15817篇
  1990年   15950篇
  1989年   15625篇
  1988年   14308篇
  1987年   14199篇
  1986年   13168篇
  1985年   12687篇
  1984年   9394篇
  1983年   8000篇
  1982年   4177篇
  1979年   8937篇
  1978年   6383篇
  1977年   5149篇
  1976年   5504篇
  1975年   6613篇
  1974年   7419篇
  1973年   7158篇
  1972年   6599篇
  1971年   6309篇
  1970年   5887篇
  1969年   5467篇
  1968年   5161篇
  1967年   4621篇
  1966年   3963篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Over 20 years ago, the Birmingham Blood Centre established a facility for the cryopreservation of bone marrow (BM) for patients in the West Midlands suffering from haematopoietic disorders and for whom a bone marrow transplant was indicated. Today, the use of mobilised peripheral blood (PBSC) has overtaken bone marrow as the source of stem cells for transplantation and the numbers of patients benefitting and the diversity of conditions being treated has increased enormously. Allogeneic transplants, using stem cells from healthy donors, have become increasingly successful as a result of an improving understanding of the complexities of the HLA histocompatibility system. Additionally umbilical cord blood (HUC), which in the 1980s was recognised as a source of stem cells, can now be collected and used for transplantation. As scientific knowledge and the clinical management of patients has advanced, so too have laboratory methods for manipulating cell products to enrich or deplete certain cell populations (e.g. by CD34+cell selection) in order to minimise potentially fatal graft-versus-host disease (GVHD) or to eliminate tumour cells in the case of autologous patients. Donor lymphocytes (DLI) may also be collected and used to aid a graft-versus-leukaemia (GVL) effect. The laboratory is currently developing protocols for immunotherapy using virus-specific T cells which can be prepared and infused to combat potentially fatal CMV disease post-transplant. Clinical trials of vaccines employing tumour specific dendritic cells for treating patients with hepatocellular carcinoma (HCC) and metastatic melanoma (MM), which do not respond to conventional treatments, are also underway. The advances and expansion in the Stem Cell and Immunotherapy (SCI) service in Birmingham over the last 10 year period are reflected in the table below:
 
  相似文献   
992.
993.
BACKGROUND: Mucosa-infiltrated granulocyte neutrophils are an early characteristic of inflammation and the main histological feature of active ulcerative colitis. Mucosal healing has recently been indicated as an important tool in the evaluation of response to treatment. While several studies have stressed the efficacy of granulocyte-monocyte-apheresis in inducing clinical remission in active ulcerative colitis, few data are available on mucosal features. AIM: Aim of this study was to assess the effects of granulocyte-monocyte-apheresis on clinical and mucosal features in patients with ulcerative colitis, dependent upon or refractory to steroids. MATERIAL AND METHODS: From April 2004 to April 2005, 12 patients (5 females, 7 males, mean age 49 years, range 33-71 years), with mild-moderate ulcerative colitis (six left colitis, six pancolitis) dependent/refractory upon steroids were enrolled. Each patient was treated for a 5-week period with five cycles of granulocyte-monocyte-apheresis. Patients were evaluated at baseline and 1 week after the last apheresis by means of Global Physician Assessment, quality of life features, laboratory tests (erythrocyte sedimentation rate, CRP, full blood count, faecal calprotectine), endoscopy and histology. RESULTS: At week 6 of follow-up, complete mucosal healing was observed in 3 out of 12 patients, partial mucosal healing in 8 patients and no change in 1 patient. Clinical response was complete in 8 out of 12 patients. CONCLUSIONS: These data suggest that granulocyte-monocyte-apheresis induces an improvement both in clinical and mucosal lesions in steroid-dependent/refractory ulcerative colitis. Of note, the reduction in granulocyte infiltration and the improvement in mucosal lesions are accompanied by a reduction in faecal calprotectine.  相似文献   
994.
GRASSPHO     
V. Frasie 《Oncologie》2006,8(1):hs79-hs80
  相似文献   
995.
996.
A 44-year-old man with right-sided herpes zoster ophthalmicus (HZO) developed ipsilateral third and sixth cranial nerve palsies and first-division trigeminal (fifth cranial nerve) sensory loss. MRI revealed contrast enhancement of the cisternal and cavernous portions of the third cranial nerve and high signal on a FLAIR sequence within the ipsilateral medulla at the presumed location of the trigeminal nucleus and tract. To our knowledge, this is the first report of the combination of these imaging findings in HZO.  相似文献   
997.
AIM: The authors report an alternative procedure to carotid endarterectomy with internal carotid artery (ICA) segmental resection and end-to-end anastomosis associated with temporary shunt and venous patch angioplasty. Design: prospective cohort study. METHODS: Between May 1995 and December 2004, 192 patients underwent 200 primary CEAs for significant ICA stenosis. There were 131 men and 61 women with a mean age of 72.4+/-8.4 years. The indications for CEA were asymptomatic lesions in 51.5%, transient ischemic attack in 27.5% and stroke in 21%. RESULTS: The combined early morbidity and mortality rate was 2%. Two patients died, one due to fatal intracerebral hemorrhage and the second patient died of acute mesenteric ischemia. Neurological complications occurred in 2 patients, including 1 TIA and 1 nondisabling cerebrovascular accident. Non-neurological complications occurred in 26 patients (13.5%). Seventeen patients (8.8%) developed hypertension, 3 neck hematomas (1.5%) required surgical evacuation, 1 patient had reversible supraventricular arrhythmia (0.5%) and 1 patient had pneumonia (0.5%). Furthermore, 1 asymptomatic carotid occlusion was identified (0.5%) and 3 patients suffered permanent cranial nerve injury (1.5%). Mean follow-up was 45.7 months and there were 41 late deaths (21.8%). Survival rates at 1 and 5 years were 96.7+/-1.2% and 73.58+/-4.2%, respectively. CONCLUSIONS: CEA with ICA shortening and reanastomosis is a safe and reliable procedure without any increase in morbidity or mortality.  相似文献   
998.
Bhatia  G.  S.  Sosin  M.  D.  Patel  J.  V.  孙凯 《世界核心医学期刊文摘》2006,2(8):58-59
目的:本研究旨在明确左心室收缩功能障碍在临床类风湿病(RD)患者中是否较正常人群中更常见,并评价脑利钠肽(BNP)的诊断价值。背景:RD患者罹患缺血性心脏病的风险增加,而采用超声心动图评估RD患者心功能不全的大型研究却少见。假定左心室收缩功能障碍在RD患者中较正常人群中更为  相似文献   
999.
1000.
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.  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