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   11143篇
  免费   761篇
  国内免费   56篇
耳鼻咽喉   94篇
儿科学   493篇
妇产科学   163篇
基础医学   1557篇
口腔科学   188篇
临床医学   987篇
内科学   2132篇
皮肤病学   217篇
神经病学   1155篇
特种医学   809篇
外国民族医学   5篇
外科学   1552篇
综合类   93篇
一般理论   6篇
预防医学   548篇
眼科学   240篇
药学   993篇
中国医学   7篇
肿瘤学   721篇
  2021年   116篇
  2019年   102篇
  2018年   154篇
  2017年   104篇
  2016年   164篇
  2015年   195篇
  2014年   205篇
  2013年   322篇
  2012年   395篇
  2011年   449篇
  2010年   283篇
  2009年   252篇
  2008年   378篇
  2007年   420篇
  2006年   429篇
  2005年   378篇
  2004年   435篇
  2003年   409篇
  2002年   340篇
  2001年   349篇
  2000年   351篇
  1999年   287篇
  1998年   231篇
  1997年   223篇
  1996年   218篇
  1995年   168篇
  1994年   135篇
  1993年   154篇
  1992年   239篇
  1991年   239篇
  1990年   225篇
  1989年   294篇
  1988年   257篇
  1987年   243篇
  1986年   230篇
  1985年   252篇
  1984年   155篇
  1983年   123篇
  1982年   116篇
  1981年   100篇
  1980年   118篇
  1979年   153篇
  1978年   106篇
  1977年   97篇
  1976年   129篇
  1975年   125篇
  1974年   96篇
  1973年   75篇
  1971年   89篇
  1970年   83篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Computer-assisted design and manufacturing technology has been used to create solid models of five unusually complex, multidirectional malunions of distal radius fractures. Preoperative planning was dramatically enhanced by the ability to perform the surgical procedure on these models, with a model of the uninjured limb used for comparison. All five patients had significant malunions, with malrotation in the horizontal plane in five and an impacted articular fragment in two. A satisfactory outcome was achieved in each case.  相似文献   
32.
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs.  相似文献   
33.
Significant patellofemoral chondromalacia was observed three months after operations on goat knees that had an excised anterior cruciate ligament (ACL) replaced and then were immobilized for six weeks with a rigid external pin and frame fixator. To determine if the patellofemoral morbidity rate could be reduced, another group of goats was treated with the same operation but without immobilization. The legs of the animals in the immobilized group had muscle weakness and the animals only occasionally used their legs for the next three to four weeks. The animals in the mobilized group protected the leg for only one to two days after surgery, and by ten to 12 days were actively moving the knee. Severe patellofemoral articular cartilage erosions occurred in the immobilized goats but not in the mobilized group. Postoperative immobilization was detrimental to the joint function and to a successful ACL reconstruction.  相似文献   
34.
In many altricial species, fear responses such as freezing do not emerge until sometime later in development. In infant rats, fear to natural predator odors emerges around postnatal day (PN) 10 when infant rats begin walking. The behavioral emergence of fear is correlated with two physiological events: functional emergence of the amygdala and increasing corticosterone (CORT) levels. Here, we hypothesize that increasing corticosterone levels influence amygdala activity to permit the emergence of fear expression. We assessed the relationship between fear expression (immobility similar to freezing), amygdala function (c-fos) and the level of corticosterone in pups in response to presentation of novel male odor (predator), littermate odor and no odor. CORT levels were increased in PN8 pups (no fear, normally low CORT) by exogenous CORT (3 mg/kg) and decreased in PN12 pups (express fear, CORT levels higher) through adrenalectomy and CORT replacement. Results showed that PN8 expression of fear to a predator odor and basolateral/lateral amygdala activity could be prematurely evoked with exogenous CORT, while adrenalectomy in PN12 pups prevented both fear expression and amygdala activation. These results suggest that low neonatal CORT level serves to protect pups from responding to fear inducing stimuli and attenuate amygdala activation. This suggests that alteration of the neonatal CORT system by environmental insults such as alcohol, stress and illegal drugs, may also alter the neonatal fear system and its underlying neural control.  相似文献   
35.
This study assessed physiological activity in patients with chronic insomnia before sleep, during sleep and in response to acute stress. Twenty-four subjects with chronic insomnia and 25 normal sleepers slept in the laboratory overnight and were given a stressful performance task in the morning. Heart rate was significantly higher in the insomniac group at night. The next morning, heart rate was not different at baseline, but was significantly higher during the performance task in the insomniac group. These results are discussed as supporting the notion that insomniacs have greater physiological responsivity to stress. Further research is needed to determine if altered physiological activity is a cause or consequence of insomnia.  相似文献   
36.
Ninety-three women with FIGO stage II epithelial ovarian carcinoma underwent comprehensive surgical staging and were randomized prospectively to therapy consisting of either intraperitoneal radioactive phosphorus or oral melphalan. No patient had gross residual disease at the time of randomization. Ten of the forty-five women treated with melphalan experienced severe bone marrow depression at some time during therapy and two women expired from leukemia. Four of the forty-eight women treated with intraperitoneal phosphorus required surgical reexploration for intestinal obstruction or bowel injury. Twenty-one women died of their disease. Survival was not statistically different between the two treatment arms. The 5-year actuarial survival was 78%.  相似文献   
37.
The cholesterol-fed rat model has been used to examine the distribution of radiolabeled cholesterol by whole-body autoradiographic and quantitative videodensitometric methods. Animals were fed a hypercholesterolemic diet for 7 days, and were subsequently killed at 3, 6, 12, 24, or 72 h following a single oral dose of [14C]cholesterol. Maximum blood and tissue levels were observed at 12 h, while liver and adrenals were the most intensely labeled tissues. Liver maintained consistently high levels over the course of the study, while activity in other tissues declined moderately by 72 h, indicating the long half-life of cholesterol radioequivalents in tissue. The results of these experiments suggest that autoradiographic examination of cholesterol distribution in animals treated with pharmaceutical agents designed to modify cholesterol absorption or clearance will be useful in providing supplemental or confirmatory information on the drugs' mode of action.  相似文献   
38.
353 patients with stages pTis, pT1-2, pN0-1, cM0 breast cancer have been treated consecutively by breast conserving therapy in a prospective, nonrandomized study at the University Hospital Basel and the Women's Clinic Rheinfelden/Baden/Germany. The median age was 47 years, the median follow-up time 67 months, and 4% only of this collective were lost to follow-up after a median time of 42 months. In 79% of the cases the tumor was excised totally, while in 19% the resection margins were positive and in 2% only the margins were not available for histological judgement. The rate of local failure reached 8% with a median time interval of 53 months. 116 patients showed postactinic induration in the primary tumor region. 73 of these were given additional diagnostic examination: The postactinic induration was judget clinically suspicious in 51 cases and clinically nonsuspicious of local failure in 22 cases. All 73 patients received additional examination by mammography and biopsy. By comparison with the histological results the clinical results were correct in 59% and false in 41%, while the mammographic results were correct in 82% and false in 18% of the cases.  相似文献   
39.
Epigard (Synthes, Paoli, PA), a synthetic skin substitute, is useful in the temporary covering of surgical wounds. The dressing adheres to the wound bed, provides hemostasis, and aids neovascularization. When removed after 2-3 days, the surgeon has a wound ready to accept a graft.  相似文献   
40.
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