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   1053篇
  免费   72篇
  国内免费   78篇
耳鼻咽喉   1篇
儿科学   43篇
妇产科学   13篇
基础医学   104篇
口腔科学   17篇
临床医学   148篇
内科学   262篇
皮肤病学   22篇
神经病学   16篇
特种医学   290篇
外科学   37篇
综合类   24篇
预防医学   85篇
眼科学   13篇
药学   77篇
肿瘤学   51篇
  2023年   3篇
  2021年   2篇
  2020年   2篇
  2018年   12篇
  2017年   14篇
  2016年   17篇
  2015年   17篇
  2014年   23篇
  2013年   15篇
  2012年   18篇
  2011年   7篇
  2010年   24篇
  2009年   39篇
  2008年   18篇
  2007年   71篇
  2006年   9篇
  2005年   30篇
  2004年   16篇
  2003年   21篇
  2002年   22篇
  2001年   25篇
  2000年   19篇
  1999年   27篇
  1998年   67篇
  1997年   74篇
  1996年   51篇
  1995年   64篇
  1994年   41篇
  1993年   39篇
  1992年   23篇
  1991年   24篇
  1990年   20篇
  1989年   42篇
  1988年   37篇
  1987年   33篇
  1986年   27篇
  1985年   47篇
  1984年   24篇
  1983年   16篇
  1982年   28篇
  1981年   16篇
  1980年   27篇
  1979年   6篇
  1978年   4篇
  1977年   14篇
  1976年   16篇
  1975年   10篇
  1974年   1篇
  1970年   1篇
排序方式: 共有1203条查询结果,搜索用时 0 毫秒
101.
102.
103.
104.

Background  

Leishmaniases are among the most proteiform parasitic infections in humans ranging from unapparent to cutaneous, mucocutaneous or visceral diseases. The various clinical issues depend on complex and still poorly understood mechanisms where both host and parasite factors are interacting. Among the candidate factors of parasite virulence are the A2 genes, a family of multiple genes that are developmentally expressed in species of the Leishmania donovani group responsible for visceral diseases (VL). By contrast, in L. major determining cutaneous infections (CL) we showed that A2 genes are present in a truncated form only. Furthermore, the A2 genomic sequences of L. major were considered subsequently to represent non-expressed pseudogenes [1]. Consequently, it was suggested that the structural and functional properties of A2 genes could play a role in the differential tropism of CL and VL leishmanias. On this basis, it was of importance to determine whether the observed structural/functional particularities of the L. major A2 genes were shared by other CL Leishmania, therefore representing a proper characteristic of CL A2 genes as opposed to those of VL isolates.  相似文献   
105.
Push enteroscopy in the investigation of small-intestinal disease   总被引:3,自引:0,他引:3  
We report our experience with small-bowel push enteroscopy in 50 patients. The indications for push enteroscopy were: anaemia/occult gastrointestinal bleeding (22 patients); overt gastrointestinal bleeding (17 patients); abnormal small-bowel radiology (8 patients) and miscellaneous (3 patients). In those with undiagnosed gastrointestinal bleeding/anaemia, abnormalities were detected in 24/39 patients (62%): small bowel arteriovenous malformations (AVMs) were detected in 19 (49%), and five (13%) had lesions in the upper gastrointestinal tract. Seventeen patients had heater-probe ablation therapy of vascular lesions: nine patients had small-intestinal lesions, four patients gastric lesions, and four patients combined gastric and small- intestinal lesions. In those with abnormal small-bowel radiology, abnormalities were detected in 6/8 patients. We conclude that (i) push enteroscopy can establish a diagnosis in a high proportion of patients with gastrointestinal bleeding; (ii) heater-probe ablation therapy of vascular lesions can be performed routinely at the time of enteroscopy; (iii) a significant proportion of patients (9/50) referred for enteroscopy with undiagnosed gastrointestinal bleeding have lesions in the stomach/proximal duodenum missed at diagnostic endoscopy. Push enteroscopy is a valuable diagnostic and therapeutic endoscopic procedure.   相似文献   
106.
Summary— Neuropeptide gamma (NPγ) induced a contractile response of the human isolated bronchus which was potentiated by the neutral endopeptidase inhibitor, phosphoramidon, but was not modified by atropine and indomethacin. NPγ was 3.31-fold more potent than NKA. Contractile response curves to NPγ were shifted to the right and maximal responses reduced by the non-peptide NK2-receptor antagonist, SR 48968. The pKB of SR 48968 (8.94 ± 0.18, n = 15), calculated according to Kenakin (1987) was very close to that reported for [Nle10]-NKA (4–10), a specific agonist of neurokinin NK2-receptors (8.86 ± 0.13, n = 13), suggesting that the contractile effects of NPγ on the human isolated bronchus were mediated through NK2A-receptors.  相似文献   
107.
Malignant lymphoma particularly of T phenotype can be associated with specific or non specific cutaneous lesions. These cutaneous manifestations can occur at the onset of the disease being sometimes the revealing sign or they can appear during the course of the lymphoreticular malignancies. Glomerulonephritis was also described in lymphoma. Ki- positive large cell lymphoma was recently identified. A new case is reported with lymphadenopathy and intestinal localisation revealed by cutaneous and mucosal ulcerations principally in the mouth and a focal segmental glomerulonephritis with endo- and extracapillary proliferation. The absence of lymphoma in cutaneous and renal lesions and the clinical presentation support the hypothesis of paraneoplastic manifestations, may be related to a vasculitis.  相似文献   
108.
In 990, Anhalt et al described a newly autoimmune billious disease: paraneoplastic pemphigus, in five patients. It was characterized by a distinct set of circulating autoantibodies from those in the sera of patients with pemphigus vulgaris and superficial pemphigus. We report a 7 year-old man with chronic lymphocytic leukemia of years duration who developed a severe mucocutaneous eruption with clinical and immunofluorescence findings of pemphigus vulgaris evolving into an oral bullous lichen planus presentation. Evaluation of his serum confirmed the presence of autoantibodies specific for paraneoplastic pemphigus by indirect immunofluorescence on rat-bladder and immunoprécipitation. Subsequently, additional cases have been reported in the literature. All occured in patients with various neoplastic conditions. These patients present with polymorphous skin lesions and severe erosive oral disease. Histologic examination shows interface dermatitis and keratinocyte necrosis in addition to acantolysis. Direct immunofluorescence may reveal deposition of immunoglobulin and/or complement at the basement membrane as well as deposition on epithelial cell surfaces. Circulating IgG anti-cell-surface antibodies are detectable with both stratified and stratified epithelia as substrates. These antibodies immunoprecipitate a complex of four desmosomal proteins, including desmoplakin I (50 kDa), the bullous pemphigoid antigen (0 kDa), desmoplakin II (0 kDa) and a 90 kDa antigen.  相似文献   
109.
110.
In an attempt to decrease the relapse rate after bone marrow transplantation (BMT) for advanced acute leukemia, we initiated studies using 131I-labeled anti-CD45 antibody (BC8) to deliver radiation specifically to hematopoietic tissues, followed by a standard transplant preparative regimen. Biodistribution studies were performed in 23 patients using 0.5 mg/kg trace 131I-labeled BC8 antibody. The BC8 antibody was cleared rapidly from plasma with an initial disappearance half-time of 1.5 +/- 0.2 hours, presumably reflecting rapid antigen- specific binding. The mean radiation absorbed doses (cGy/mCi131I administered) were as follows: marrow, 7.1 +/- 0.8; spleen, 10.8 +/- 1.4; liver, 2.7 +/- 0.2; lungs, 2.1 +/- 0.1; kidneys, 0.7 +/- 0.1; and total body, 0.4 +/- 0.03. Patients with acute myelogenous leukemia (AML) in relapse had a higher marrow dose (11.4 cGy/mCi) than those in remission (5.2 cGy/mCi; P = .001) because of higher uptake and longer retention of radionuclide in marrow. Twenty patients were treated with a dose of 131I estimated to deliver 3.5 Gy (level 1) to 7 Gy (level 3) to liver, with marrow doses of 4 to 30 Gy and spleen doses of 7 to 60 Gy, followed by 120 mg/kg cyclophosphamide (CY) and 12 Gy total body irradiation (TBI). Nine of 13 patients with AML or refractory anemia with excess blasts (RAEB) and two of seven with acute lymphocytic leukemia (ALL) are alive disease-free at 8 to 41 months (median, 17 months) after BMT. Toxicity has not been measurably greater than that of CY/TBI alone, and the maximum tolerated dose has not been reached. This study demonstrates that with the use of 131I-BC8 substantially greater doses of radiation can be delivered to hematopoietic tissues as compared with liver, lung, or kidney, which may improve the efficacy of marrow transplantation.  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