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   1142篇
  免费   79篇
耳鼻咽喉   30篇
儿科学   129篇
妇产科学   17篇
基础医学   182篇
口腔科学   28篇
临床医学   106篇
内科学   200篇
皮肤病学   4篇
神经病学   97篇
特种医学   23篇
外科学   136篇
综合类   6篇
预防医学   121篇
眼科学   5篇
药学   39篇
肿瘤学   98篇
  2021年   12篇
  2015年   10篇
  2014年   17篇
  2013年   15篇
  2012年   26篇
  2011年   27篇
  2009年   14篇
  2008年   25篇
  2007年   21篇
  2006年   37篇
  2005年   30篇
  2004年   31篇
  2003年   36篇
  2002年   43篇
  2001年   32篇
  2000年   31篇
  1999年   33篇
  1998年   18篇
  1997年   9篇
  1996年   7篇
  1995年   8篇
  1994年   14篇
  1993年   11篇
  1992年   36篇
  1991年   51篇
  1990年   49篇
  1989年   49篇
  1988年   39篇
  1987年   49篇
  1986年   35篇
  1985年   29篇
  1984年   23篇
  1983年   18篇
  1982年   15篇
  1981年   14篇
  1979年   25篇
  1978年   20篇
  1977年   12篇
  1976年   13篇
  1975年   12篇
  1974年   18篇
  1973年   19篇
  1972年   20篇
  1971年   19篇
  1970年   18篇
  1969年   15篇
  1968年   13篇
  1967年   7篇
  1965年   9篇
  1937年   7篇
排序方式: 共有1221条查询结果,搜索用时 15 毫秒
1.
Short latency auditory nerve and brainstem evoked responses (BAERs) and long latency cortical auditory evoked responses (CAERs) in 75 long-term traumatic brain injury (TBI) cases were compared. CAERs were found to be significantly correlated with clinical disability as measured by the Disability Rating Scale, while BAERs were not. Also, BAER patterns were consistently and significantly less abnormal and less sensitive to overall dysfunction than CAER patterns. Findings support previous observations that BAERs have relatively little utility for evaluating in surviving TBI patients the degree of overall brain impairment. In general, long latency AEP patterns are better able to reflect the extent and severity of brain dysfunction and overall clinical condition than are short latency AEP patterns in long-term severe TBI patients, and these patterns should be obtained routinely in the evaluation of such patients.  相似文献   
2.
Preoperative screening for potential cardiac complications is crucial in making rational decisions about surgery. A number of classification schemes are available to aid the primary care physician in assessing a patient's perioperative cardiac risk. In general, these schemes enable the physician to place patients in low-risk, moderate-risk and high-risk categories. Patients at low risk can often be safely referred for surgery with minimal preoperative evaluation, while those at potentially high risk frequently need further assessment and medical or surgical treatment of cardiac disease prior to surgery. The classification schemes are most accurate in identifying patients at high risk for perioperative cardiac complications. However, patients with silent underlying cardiac disease are often underclassified with respect to potential risk. For those patients, accurate prediction of perioperative cardiac complications can be challenging.  相似文献   
3.
We studied reproductive outcomes in a cohort of 7,450 pregnancies identified through three Kaiser-Permanente facilities in the San Francisco Bay Area, in relation to exposure to the pesticide malathion, applied aerially to control an infestation by the Mediterranean fruit fly. We included in the cohort all women over age 17 who were registered at these facilities and who were confirmed as pregnant during the spraying period. Residence histories throughout the pregnancy were obtained by mailed questionnaire or telephone interview from 933 women with adverse outcomes and a sample of 1,000 women with normal outcomes, and were converted to geographical coordinates. We linked the coordinates for malathion spraying corridors with the residence coordinates to create individual exposure indices for each week of pregnancy. The statistical analysis compared each of the adverse pregnancy outcome groups against an appropriate control group using logistic regression or survival time regression approaches. After adjustment for various confounders, no important association was found between malathion exposure and spontaneous abortion, intrauterine growth retardation, stillbirth, or most categories of congenital anomalies. Gastrointestinal anomalies were related to second trimester exposure (odds ratio = 2.6), based on 13 cases and not specific to any particular International Classification of Diseases code.  相似文献   
4.
5.
Traumatic pseudoaneurysms of the superior mesenteric artery (SMA) are extremely rare. We describe two cases of posttraumatic proximal SMA pseudoaneurysms with symptoms of gastric outlet obstruction. Repair was accomplished by aorta-SMA bypass with saphenous vein. Injuries to the proximal SMA are easily missed at laparotomy, especially if intestinal ischemia or hematomas are absent. Recognition and repair are stressed to avoid the complications associated with pseudoaneurysm formation.  相似文献   
6.
Our recent experience with peritonitis in patients over the age of 55 years undergoing continuous ambulatory peritoneal dialysis between 1979 and 1989 is reviewed. Thirty-seven patients in this age group underwent Tenckhoff catheter insertion. Severe catheter-related peritonitis occurred at a rate of 1.41 episodes per patient per year. Overall, there were 61 episodes of peritonitis in 31 patients, with an overall mortality rate of 7%. When systemic signs of sepsis were present, this rate rose to 25%. All deaths were associated with fungal, pseudomonal, or polymicrobial infections. Management of these infections may require aggressive measures including repeated laparotomy for control of sepsis.  相似文献   
7.
8.
OBJECTIVES. This study examined health care-seeking behaviors to elucidate factors that contribute to differences in patterns of coronary heart disease between African Americans and Whites. The prevalence of diagnosed coronary heart disease, patients' perceptions of symptoms and attribution of symptoms, and predictors of painful symptoms and attribution of cardiac symptoms were examined. METHODS. The study involved 2416 patients admitted with diagnoses of coronary artery disease, ischemic heart disease, or myocardial infarction or to rule out myocardial infarction. Structured interview questions were used to obtain demographic information, symptoms precipitating admission, and patients' attribution of their symptoms. Discharge diagnoses were obtained from hospital records. RESULTS. Acute myocardial infarction, unstable angina, nonacute ischemic heart disease, and atherosclerosis were more frequent in White patients. For Blacks, the odds of reporting painful symptoms were only 64% of the odds found for Whites when other factors were controlled, and the odds of attributing symptoms to cardiac origins were almost 50% lower for Blacks than for Whites. CONCLUSIONS. The tendency of Blacks to report fewer painful symptoms and to attribute their symptoms to noncardiac origins may contribute to differences in care-seeking and in medical management of heart disease in Blacks.  相似文献   
9.
10.
Hereditary hearing loss (HHL) is one of the most common congenital disorders and is highly heterogeneous. Mutations in the connexin 26 (CX26) gene (GJB2) account for about 20% of all cases of childhood deafness, and approach 50% in documented recessive cases of non-syndromic hearing loss. In addition, a single mitochondrial DNA mutation, mt1555A>G, in the 12S rRNA gene (MTRNR1), is associated with familial cases of progressive deafness. Effective screening of populations for HHL necessitates rapid assessment of several of these potential mutation sites. Pyrosequencing links a DNA synthesis protocol for determining sequence to an enzyme cascade that generates light whenever pyrophosphate is released during primer strand elongation. We assessed the ability of Pyrosequencing to detect common mutations causing HHL. Detection of the most common CX26 mutations in individuals of Caucasian (35delG), Ashkenazi (167delT), and Asian (235delC, V37I) descent was confirmed by Pyrosequencing. A total of 41 different mutations in the CX26 gene and the mitochondrial mt1555A>G mutation were confirmed. Genotyping of up to six different adjacent mutations was achieved, including simultaneous detection of 35delG and 167delT. Accurate and reproducible results were achieved taking advantage of assay flexibility and experimental conditions easily optimized for a high degree of standardization and cost-effectiveness. The standardized sample preparation steps, including target amplification by PCR and preparation of single-stranded template combined with automated sequence reaction and automated genotype scoring, positions this approach as a potentially high throughput platform for SNP/mutation genotyping in a clinical laboratory setting. .  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