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   3854篇
  免费   167篇
  国内免费   21篇
耳鼻咽喉   28篇
儿科学   105篇
妇产科学   64篇
基础医学   575篇
口腔科学   49篇
临床医学   191篇
内科学   1087篇
皮肤病学   47篇
神经病学   270篇
特种医学   169篇
外科学   487篇
综合类   20篇
预防医学   85篇
眼科学   55篇
药学   320篇
中国医学   34篇
肿瘤学   456篇
  2023年   19篇
  2022年   50篇
  2021年   68篇
  2020年   50篇
  2019年   61篇
  2018年   81篇
  2017年   52篇
  2016年   69篇
  2015年   81篇
  2014年   115篇
  2013年   119篇
  2012年   197篇
  2011年   239篇
  2010年   139篇
  2009年   130篇
  2008年   219篇
  2007年   257篇
  2006年   241篇
  2005年   262篇
  2004年   247篇
  2003年   289篇
  2002年   271篇
  2001年   32篇
  2000年   37篇
  1999年   59篇
  1998年   73篇
  1997年   58篇
  1996年   55篇
  1995年   41篇
  1994年   50篇
  1993年   58篇
  1992年   33篇
  1991年   27篇
  1990年   27篇
  1989年   25篇
  1988年   26篇
  1987年   20篇
  1986年   26篇
  1985年   16篇
  1984年   20篇
  1983年   17篇
  1982年   9篇
  1981年   13篇
  1980年   10篇
  1979年   8篇
  1978年   8篇
  1977年   4篇
  1974年   4篇
  1969年   3篇
  1968年   3篇
排序方式: 共有4042条查询结果,搜索用时 15 毫秒
101.
102.
103.
Measles‐rubella‐mumps vaccination is routine in many countries, but the mumps vaccine remains voluntary and is not covered by insurance in Japan. A 5‐year‐old Japanese boy who had not received the mumps vaccine was affected by mumps parotitis. Several days later, he presented with various neurological abnormalities, including akinesia, mutism, dysphagia, and uncontrolled respiratory disorder. Mumps encephalitis was diagnosed. Despite steroid pulse and immunoglobulin treatment, the disease progressed. Magnetic resonance imaging showed necrotic changes in bilateral basal ganglia, midbrain, and hypothalamus. At 1 year follow up, he was bedridden and required enteral feeding through a gastric fistula and tracheostomy. Mumps vaccination should be made routine as soon as possible in Japan, because mumps encephalitis carries the risk of severe sequelae.  相似文献   
104.
Summary A case of cerebellar hemangioblastoma associated with slight but definite erythrocytosis is reported. Operative removal of the tumor resulted in the reversion to a normal blood picture. Erythropoietin-like activity, being non-dialyzable and relatively thermolabile, was detected in the fluid aspirated from tumor. The mother of the reported patient suffered from the same disease which was also associated with a slight degree of erythrocytosis.
Zusammenfassung Es wird über den Fall eines cerebellaren Hämangioblastoms begleitet von einer leichten, aber doch eindeutig diagnostizierten Erythrozytose berichtet. Die operative Entfernung des Tumors führte zu einer Renormalisierung des Blutbildes. In der aus dem Tumor aspirierten Flüssigkeit wurde eine erythropoetinähnliche Wirkung entdeckt, die relativ thermolabil und nicht dialysierbar war. Die Mutter des geschilderten Patienten litt an der gleichen Krankheit, die ebenfalls von einer Erythrozytose leichten Grades begleitet war.
  相似文献   
105.
A 45-year-old female with acute myelogenous leukemia (AML-M6) received an allogeneic stem cell transplantation from an HLA-identical sibling donor in June 2002. Prophylaxis against graft-versus-host disease (GVHD) consisted of cyclosporine (CsA) and short-term methotrexate. Acute GVHD did not occur and CsA was discontinued on day 145 after transplantation. However, soon thereafter she suffered from conjunctivitis, stomatitis and liver dysfunction with hypercholesterolemia and was diagnosed as having chronic GVHD. The liver dysfunction and hypercholesterolemia failed to improve despite the administration of CsA and prednisolone. Atrovastatin was not effective and immunosuppressive therapy for two months including ursodeoxycholic acid finally improved the jaundice and hypercholesterolemia. Although lipid metabolism analysis in this case disclosed the same findings as in other intrahepatic cholestatic liver diseases, the results show that the improvement of hypercholesterolemia in chronic GVHD needs the same treatment as chronic GVHD.  相似文献   
106.
 An acute leukemia with an unusual immunophenotype developed in a 17-year-old girl. At the initial presentation, extramedullary involvement was not evident, but with advancing disease, massive splenomegaly and an osteolytic rib tumor developed. The disease was aggressive and refractory to intensive chemotherapeutic regimens for myeloid and lymphoid malignancies, and the patient died 3 months after the initial presentation. The leukemic cells were of irregular shape and variable size; they had deeply indented or bi-lobed nuclei and relatively fine, azurophilic granules in their cytoplasm. They were positive for acid phosphatase and β-glucuronidase in granular staining, but they were negative for myeloperoxidase. The leukemic cells had a unique immunophenotype: it was positive for T-cell antigens (CD1a, CD2, cytoplasmic CD3, CD4), myeloid antigens (CD13 and CD33), NK-cell antigen (CD56), CD19 and CD30. DNA analysis revealed no gene rearrangement in the T-cell receptor β, γ and δ, or immunoglobulin heavy chain genes. The leukemic cells of our patient are thought to have arisen from the transformation of a putative precursor cell common to both the T- and NK-cell lineage in the bone marrow. The current literature on precursor NK-cell malignancy is reviewed, and its clinicopathological feature is discussed. Received: 29 April 1998 / Accepted: 28 August 1998  相似文献   
107.
108.
OBJECTIVES: The aim of this work was to determine whether mitral valve (MV) annuloplasty benefits patients with moderate/severe (3+/4+) functional ischemic mitral regurgitation (MR) who undergo coronary artery bypass grafting (CABG). BACKGROUND: Mitral regurgitation is a strong predictor of poor outcomes in patients with ischemic cardiomyopathy; whether correcting it at the time of CABG improves outcomes is less certain. METHODS: From 1991 to 2003, 390 patients with 3+/4+ ischemic MR had CABG with (n = 290) or without (n = 100) MV annuloplasty. Groups were propensity-matched using demographics, extent of coronary disease, regional wall motion, and quantitative electrocardiography. Survival, echocardiographic severity of MR, and New York Heart Association (NYHA) functional class were compared. RESULTS: One-, 5-, and 10-year survival was 88%, 75%, and 47% after CABG alone and 92%, 74%, and 39% after CABG + MV annuloplasty (p = 0.6). Mortality was increased in patients with severe lateral wall motion abnormalities (p = 0.05), ST-segment elevation in lateral leads (p < 0.004), and higher QRS voltage sum (p < 0.0001). Patients undergoing CABG alone were more likely to have 3+/4+ postoperative MR than those undergoing CABG + MV annuloplasty (48% vs. 12% at 1 year, p < 0.0001). The NYHA functional class substantially improved in both groups (p < 0.001) and remained improved; at 5 years, 23% of patients having CABG + mitral annuloplasty and 25% having CABG alone were in NYHA functional class III/IV. CONCLUSIONS: Although CABG + MV annuloplasty reduces postoperative MR and improves early symptoms compared with CABG alone, it does not improve long-term functional status or survival in patients with severe functional ischemic MR. The MV annuloplasty in this setting, without addressing fundamental ventricular pathology, is insufficient to improve long-term clinical outcomes.  相似文献   
109.
A 43-year-old Japanese woman presented hypertension, hypokalemia and typical Cushingoid signs. Autonomous secretion of both aldosterone and cortisol was shown. Abdominal computed tomography demonstrated a single tumor in the right adrenal gland, which established the diagnosis of combined primary aldosteronism and Cushing's syndrome. The resected tumor was a golden yellow-colored adenoma (diameter 4.3 cm) which expressed P450(aldo) and P450(11beta), causing oversecretion of both hormones from this adenoma. After tumor resection, overproduction of both hormones disappeared and she developed adrenal insufficiency, suggesting the strong suppression of normal adrenal function. This case was complicated by Hashimoto's thyroiditis.  相似文献   
110.
Luteinizing hormone (LH) consists of alpha- and beta-subunits, and synthesis and secretion of LH are regulated by gonadotropin-releasing hormone (GnRH). In order to examine the molecular mechanisms by which GnRH regulates LH secretion, we transfected alphaT3-1 cells with rat LHbeta-subunit cDNA under the control of a constitutive promoter and established a stable cell line of LH2 cells which secreted LH in response to GnRH. Pulsatile and continuous GnRH pretreatments increased gene expression of the alpha-subunit and synthesis of LH, and enhanced the LH secretion by brief treatments with GnRH and 56 mM KCl. The LH secretions were partially blocked by elimination of extracellular Ca2+. GnRH-induced LH secretion was completely inhibited by calphostin C (a protein kinase C inhibitor) and 1 microM wortmannin. In contrast to the GnRH induction, high K+-induced LH secretion was inhibited by KN93, a Ca2+/calmodulin-dependent protein kinase II inhibitor, as well as by 1 microM wortmannin. We also confirmed that activation of cAMP-pathway induced LH secretion, but activation of mitogen-activated protein (MAP) kinase pathway was not involved in LH secretion. These results suggest that GnRH directly regulates LH secretion as well as LHbeta-subunit synthesis, and that LH2 cells are a useful model for the study of LH secretion induced by several secretagogues.  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