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   15472篇
  免费   1220篇
  国内免费   61篇
耳鼻咽喉   337篇
儿科学   469篇
妇产科学   318篇
基础医学   2095篇
口腔科学   297篇
临床医学   1553篇
内科学   2856篇
皮肤病学   116篇
神经病学   1762篇
特种医学   655篇
外科学   2558篇
综合类   234篇
一般理论   12篇
预防医学   1309篇
眼科学   474篇
药学   919篇
中国医学   12篇
肿瘤学   777篇
  2022年   111篇
  2021年   346篇
  2020年   194篇
  2019年   307篇
  2018年   384篇
  2017年   302篇
  2016年   282篇
  2015年   319篇
  2014年   485篇
  2013年   675篇
  2012年   1021篇
  2011年   988篇
  2010年   600篇
  2009年   469篇
  2008年   828篇
  2007年   893篇
  2006年   949篇
  2005年   876篇
  2004年   733篇
  2003年   784篇
  2002年   714篇
  2001年   297篇
  2000年   262篇
  1999年   278篇
  1998年   194篇
  1997年   132篇
  1996年   154篇
  1995年   100篇
  1994年   104篇
  1993年   95篇
  1992年   192篇
  1991年   198篇
  1990年   190篇
  1989年   160篇
  1988年   147篇
  1987年   177篇
  1986年   136篇
  1985年   147篇
  1984年   122篇
  1983年   108篇
  1982年   85篇
  1981年   84篇
  1980年   78篇
  1979年   93篇
  1978年   92篇
  1977年   73篇
  1976年   76篇
  1974年   81篇
  1973年   66篇
  1972年   67篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
We present a patient with tuberous sclerosis and bilateral angiomyolipomaswith a right partial staghorn calculi in which the calculi was managed with a percutaneous nephrolithotomy. Despite the inherent risk of hemorrhage with a percutaneous approach compounded by the fact that this was done directly through a tumor, we were able to render the patient stone free with no intraoperative bleeding, complications, or the need for postoperative blood transfusion. To our knowledge, this is the first reported case of percutaneous nephrolithotomy directly through a renal angiomyolipoma.  相似文献   
32.
This study reports on the efficacy of a 'coma arousal procedure'. This procedure involved a programme of vigorous sensory stimulation administered to comatose patients by relatives using Comakits. An experimental group of 12 severely head-injured patients received the coma arousal procedure while a matched control group did not. Total duration of coma and weekly Glasgow Coma Scale Scores were recorded for the two groups. Results indicate that the total duration of coma was significantly shorter and that coma lightened more rapidly for the experimental group.  相似文献   
33.
Treatment of confluent monolayers of human umbilical vein endothelial cells with sublethal concentrations of hydrogen peroxide (H2O2) produces reversible cell retraction that opens gaps between adjacent cells. Despite the retraction, adjacent cells remain in contact through a network of dendrite-like processes. Retraction depends on cellular metabolism but not new protein synthesis or protein kinase C. Shape changes induced by H2O2 are accompanied by partial redistribution of actin filaments from the cell periphery in resting endothelial cells to a tangled network of centrally located filaments in H2O2-treated endothelial cells. This change in actin organization is associated with a loss of the normal distribution pattern of surface protein expression. Specifically, beta 1 and beta 3 integrins partly escape from focal adhesion plaques and migrate to the lateral and apical surface of the cell; PECAM-1 redistributes from the lateral borders to the basal surface; and ICAM-1 and ICAM-2 spread from apical caps to the basal surface and to the dendrite-like processes. The likely consequence of endothelial retraction accompanied by abnormal membrane protein distribution is a loss of normal endothelial cell functions. These changes are best considered manifestations of H2O2-induced sublethal injury that may cause endothelial dysfunction.  相似文献   
34.
The surgical management of lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) remains controversial. For in situ breast cancer local excision (LE), local excision and radiation therapy (LERT) and mastectomy (MAST) have all been advocated. A search of the English literature found 13 reports concerning the surgical management of LCIS and 12 reports concerning the management of DCIS. The data were combined in a meta-analysis of outcome. As expected, recurrence rates following LE with both LCIS 8.4%) and DCIS (17%) are high. However,the overall mortality following mastectomy for recurrence, LCIS (2.8%) and DCIS (2.3%) does not differ statistically from those treated initially with mastectomy for LCIS (0.9%) and DCIS (1.7%). We conclude from these data that local recurrence after breast conserving procedures for in situ breast cancer does not carry an ominous prognosis. This knowledge should aid in planning individual therapy.  相似文献   
35.
The decrease in membrane microviscosity of erythrocyte ghosts in the presence of clinically relevant concentrations of seven inhalation anaesthetic agents was studied using fluorescence polarization anisotropy of the membrane incorporated fluorescent probes 1,6-diphenyl- 1,3,5-hexatriene and 1-[4-trimethylammoniumphenyl]-6-phenyl-1,3,5- hexatriene. All anaesthetic agents produced a dose-dependent decrease in anisotropy of both probes, indicating decreased membrane microviscosity. The reduction in anisotropy measured at the minimum alveolar concentration (ED50) for anaesthesia was related inversely to the anaesthetic potency of the agent and was directly proportional to the hypothetical concentration of agent in the membrane calculated from lipid-water partition coefficients. These findings do not support the hypothesis that volatile anaesthetic agents act by increasing membrane microviscosity of the bulk lipid bilayer to produce anaesthesia.   相似文献   
36.
Our randomized double blinded comparison of acetaminophen versus analgesic and antiinflammatory doses of ibuprofen in the treatment of 182 subjects with knee osteoarthritis (OA) systematically evaluated soft tissue tenderness and joint swelling. Improvement in these signs of joint inflammation was associated with lessening of disability (p = 0.02), and reduction in rest pain (p = 0.07), but not with the drug treatment regimen. Thus, joint tenderness and swelling, presumptive evidence of synovitis, may not be a priori indications for use of an antiinflammatory drug, or predict greater responsiveness to treatment with an antiinflammatory drug than to a pure analgesic, in symptomatic treatment of patients with knee OA.  相似文献   
37.
Acute stroke affects large numbers of people worldwide. It causes significant morbidity and mortality. Data support the hypothesis that the public is not familiar with either the risk factors or the signs of stroke. Educating the public about stroke may result in a lower incidence of the disease as individuals modify their risk factors, and in improved outcomes as a result of reductions in delays to treatment. There is clear and convincing evidence that reducing delays to treatment of patients with acute stroke results in improved outcomes. Public education programs should be broad-based, tailored to individual audiences, and carry a common theme.  相似文献   
38.
The establishment and characterization of 11 human lung cancer cell lines are described in this article. Nine of these cell lines were established over a 5-year period, from 1983 to 1988, from patients treated at the Kingston Regional Cancer Centre. These include eight definite or probable small cell lung cancer (SCLC) lines and one adenocarcinoma line. In addition, two other SCLC cell lines were characterized. All of the lines have been in continuous culture for more than 2 years. The clinical histories of the patients from whom the cell lines were derived are outlined here. Several features of the cell lines are presented, including the following: (1) a comparison of the histologic features of the cell lines with the original biopsy specimens; (2) the expression of various markers, including cytokeratin, carcinoembryonic antigen, calcitonin, and neuron-specific enolase; (3) activities of the enzymes l-dopa decarboxylase and the brain isoenzyme of creatine kinase; (4) growth characteristics; (5) cloning efficiency in soft agar; (6) tumorigenicity in nude mice; and (7) cytogenetic studies. These cell lines, obtained directly from patients with a spectrum of drug-sensitive and drug-resistant tumors, will be valuable in vitro models of sensitivity and resistance to chemotherapy in lung cancer.  相似文献   
39.
40.
C Mowery  M Botte  G Bradley 《Orthopedics》1987,10(2):309-313
Aseptic loosening is the most common mode of failure for total knee replacements. Component breakage is rare, usually attributable to errors of design or manufacture. A case is presented in which rotational malplacement of the femoral component resulted in accelerated wear and eventual fracture of the polyethylene tibial component.  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