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   2783篇
  免费   181篇
耳鼻咽喉   11篇
儿科学   129篇
妇产科学   45篇
基础医学   308篇
口腔科学   88篇
临床医学   282篇
内科学   468篇
皮肤病学   37篇
神经病学   332篇
特种医学   155篇
外国民族医学   3篇
外科学   208篇
综合类   43篇
一般理论   1篇
预防医学   241篇
眼科学   97篇
药学   170篇
肿瘤学   346篇
  2019年   19篇
  2018年   29篇
  2017年   18篇
  2016年   28篇
  2015年   28篇
  2014年   36篇
  2013年   65篇
  2012年   82篇
  2011年   97篇
  2010年   58篇
  2009年   53篇
  2008年   141篇
  2007年   134篇
  2006年   149篇
  2005年   133篇
  2004年   120篇
  2003年   124篇
  2002年   104篇
  2001年   91篇
  2000年   103篇
  1999年   84篇
  1998年   27篇
  1997年   30篇
  1996年   22篇
  1995年   20篇
  1993年   30篇
  1992年   80篇
  1991年   75篇
  1990年   77篇
  1989年   75篇
  1988年   56篇
  1987年   54篇
  1986年   62篇
  1985年   55篇
  1984年   63篇
  1983年   46篇
  1982年   27篇
  1981年   23篇
  1980年   35篇
  1979年   56篇
  1978年   35篇
  1977年   19篇
  1976年   18篇
  1975年   23篇
  1973年   26篇
  1972年   23篇
  1971年   16篇
  1970年   20篇
  1969年   27篇
  1966年   16篇
排序方式: 共有2964条查询结果,搜索用时 343 毫秒
1.
2.
To test the reported antipanic efficacy of clonazepam, the authors randomized 72 subjects with panic disorder to 6 weeks of treatment with either alprazolam, clonazepam, or placebo. Endpoint analysis demonstrated a significant beneficial effect of both active treatments, but not placebo treatment, on the frequency of panic attacks, overall phobia ratings, and the extent of disability. Comparison of the two active treatments revealed no significant differences and no consistent tendency for one agent to be favored over another, although power to detect small differences was limited. Sedation and ataxia were the most common side effects reported, but these effects were mild and transient and did not interfere with treatment outcome. The results of this double-blind, placebo-controlled trial are consistent with previous reports of clonazepam's antipanic efficacy.  相似文献   
3.
4.
A retrospective analysis of 1,259 patients injured in all-terrain vehicle accidents over a 2-year period was performed. All patients presented to the same community hospital Emergency Department, located near a major desert off-road vehicle recreational area. The patients were characterized by demographics and Injury Severity Scores. There were 2,149 recorded injuries. Mean ISS +/- standard deviation for all patients was 5.07 +/- 4.93; among patients admitted for inpatient care, 9.83 +/- 6.46. Injury Severity Scores were independent of vehicle type (two, three, or four wheels). In this setting, injuries sustained by children were not disproportionately more severe than those sustained by adults. Where documented, alcohol use was associated with higher ISS, and the use of helmets was associated with less severe head and facial injuries. The most common diagnoses in this series were integumental injuries and fractures, frequently involving the face and extremities.  相似文献   
5.
OBJECTIVES: To determine electrocardiogram (ECG) predictors of positive cardiac markers and short-term adverse cardiac events in an undifferentiated chest pain population presenting to emergency departments (EDs). The authors hypothesized that specific ECG findings, other than those previously identified in higher-risk populations, would be predictive of cardiac outcomes and positive cardiac markers. METHODS: This study used data from a prospectively collected, retrospectively analyzed Internet-based data registry of undifferentiated chest pain patients (i*trACS). Logistic regression modeling was performed to determine the ECG findings that were predictive of 1) positive cardiac markers and 2) short-term adverse cardiac events. RESULTS: ST-segment elevation (STE), ST-segment depression (STD), pathological Q-waves (PQW), and T-wave inversion were associated with increased odds of percutaneous coronary intervention or catheterization, myocardial infarction, or coronary artery bypass grafting. The odds of creatine kinase-MB (CK-MB) measuring positive were increased if STE, STD, or PQW were present [odds ratio (OR) 2.495, 2.582, and 1.295, respectively]. A right bundle branch block tended to decrease the odds of CK-MB measuring positive (OR 0.658). A similar pattern of results was observed for troponin I (OR 3.608 for STE, 3.72 for STD, 1.538 for PQW). Troponin T showed an increased odds of measuring positive if any of STE, STD, left bundle branch block, or T-wave inversion were evident (OR 2.313, 2.816, 1.80, and 1.449, respectively). CONCLUSIONS: Initial ECG criteria can be used to predict short-term cardiac outcomes and positive cardiac markers. These findings can be important aids in the risk-stratification and aggressive treatment regimens of chest pain patients presenting to EDs.  相似文献   
6.
Neurofibromatosis is a relatively common autosomal dominant disorder with variable penetrance. The disorder usually presents in childhood. Hallmarks of type 1 neurofibromatosis are café-au-lait macules and neurofibromas. Neurologic complications include mental retardation, learning disabilities and seizures. Tumors of the eighth cranial nerve, as well as other intracranial and spinal neoplasms, are the typical lesions in type 2 neurofibromatosis. Both forms of neurofibromatosis have a highly variable course and may result in progressive neurologic deterioration, disfigurement and impingement syndromes. In the 50 percent of cases that represent new mutations, diagnosis may be delayed if the physician is not familiar with the salient features of the disorder. Thorough initial evaluation, genetic counseling and close follow-up are important aspects of management.  相似文献   
7.
8.
The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia.  相似文献   
9.
Newborn rat calvarial bone cells were grown to confluence and subjected to a matrix of sine wave 60-kHz capacitively coupled electrical signals of various field strengths, pulse-burst patterns, and duty cycles. Both [3H] thymidine incorporation into DNA and alkaline phosphatase activity were evaluated in field strengths ranging from 0.0001 to 20 mV/cm, with pulse-burst patterns ranging from continuous to 5 milliseconds ON/495 milliseconds OFF, with daily duty cycles ranging from 0.25% to 25%. A significant increase in proliferation occurred in field strengths of 0.1, 1, and 20 mV/cm when the signal was applied continuously for six hours. Significant proliferation also occurred when the 20-mV/cm field was pulsed for six hours at 5 milliseconds ON/495 milliseconds OFF and at 5 milliseconds ON/245 milliseconds OFF. No change in alkaline phosphatase activity occurred in the 20-mV/cm field with any signal. At 1 mV/cm, there was a significant decrease in alkaline phosphatase activity in the continuous signal and in the 5 milliseconds ON/62 milliseconds OFF signal; in the lower fields evaluated, there was an actual decrease in alkaline phosphatase activity with some of the signals. The field strength plays a dominant role in determining the bone-cell's proliferative response, and to a lesser extent the alkaline phosphatase activity response, to a capacitively coupled electric field. The pulse configuration and the duty cycle are also important, but only if the proper field strength is being applied to the cell.  相似文献   
10.
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