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   15118篇
  免费   1188篇
  国内免费   155篇
耳鼻咽喉   117篇
儿科学   590篇
妇产科学   340篇
基础医学   1890篇
口腔科学   233篇
临床医学   1758篇
内科学   3048篇
皮肤病学   471篇
神经病学   1368篇
特种医学   741篇
外科学   1864篇
综合类   374篇
一般理论   7篇
预防医学   1224篇
眼科学   262篇
药学   876篇
中国医学   4篇
肿瘤学   1294篇
  2021年   168篇
  2019年   190篇
  2018年   214篇
  2017年   166篇
  2016年   185篇
  2015年   204篇
  2014年   274篇
  2013年   433篇
  2012年   567篇
  2011年   638篇
  2010年   360篇
  2009年   377篇
  2008年   598篇
  2007年   653篇
  2006年   582篇
  2005年   632篇
  2004年   548篇
  2003年   515篇
  2002年   515篇
  2001年   495篇
  2000年   526篇
  1999年   450篇
  1998年   258篇
  1997年   240篇
  1996年   214篇
  1995年   207篇
  1994年   197篇
  1993年   160篇
  1992年   378篇
  1991年   381篇
  1990年   393篇
  1989年   380篇
  1988年   298篇
  1987年   324篇
  1986年   337篇
  1985年   332篇
  1984年   213篇
  1983年   250篇
  1982年   141篇
  1981年   110篇
  1980年   112篇
  1979年   206篇
  1978年   148篇
  1977年   138篇
  1976年   151篇
  1975年   140篇
  1974年   145篇
  1973年   136篇
  1972年   107篇
  1970年   120篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
11.
12.
Late-life migraine accompaniments--further experience   总被引:3,自引:0,他引:3  
In 1980, 120 cases with late-life migrainous accompaniments resembling transient ischemic attacks were presented. In the present paper, 85 further cases examined in the past five years are analyzed. The findings support the concept advanced previously. In general, the cases are divided into the same categories: visual--21 cases, visual and paresthesias--6, visual and speech disturbance--2, visual, paresthesias and speech disturbance--3, visual, paresthesias, speech disturbance, and weakness--20, visual and brainstem symptoms--3, and cases without visual symptoms--32. The ages ranged from 40 to 73 years. Headache occurred in association with the episodes in only 40% of cases. There was a history of recurrent headache in 65%. The condition can justifiably be regarded as benign. Migrainous accompaniments account for some of the cases of transient ischemia with normal angiograms. Knowledge of the condition helps in the planning of rational management.  相似文献   
13.
To identify and compare the methods of evaluation for suspected traumatic aortic rupture, 1,031 trauma charts from 1983-1989 were reviewed. Fifty-nine patients were evaluated for possible aortic injury. Patients who died before completion of the CT or aortogram were excluded. Widening of the mediastinum on chest x ray was the most frequent indication for follow-up studies. Twenty-five had a CT of the aortic arch alone. No study showed disruption. There were no false negative studies. Thirty patients had only aortography. Twenty-four were read as normal (one false negative). Six were read as positive (one false positive). In four, both studies were performed (CT/aortography--TP/TP, TN/TN, TP/FN, FP/FP). (FP = False Positive, TP = True Positive, FN = False Negative, TN = True Negative.) Six received surgical repair of the aortic injury (one death). In this experience, CT was used successfully as a screening tool for aortic disruption. It was highly sensitive in recognizing aortic injuries when present (100% vs. 75% for aortography) and in most cases did not require aortographic verification. False positive rates were comparable (CT = 3.8%, aortography = 7.7%). Specificity was also comparable (CT = 96%, aortography = 92%). Overall, four aortograms were inaccurate while only one CT was inaccurate. We recommend the use of CT for the evaluation of widened mediastinum in the stable patient.  相似文献   
14.
Desferrioxamine (DFO) metabolism and its pharmacokinetics were studied in a swine model using high-performance liquid chromatography. DFO and three iron-binding metabolites occurred in plasma. Interindividual differences in pharmacokinetics and metabolism were observed. Urine analysis in 4 pigs showed three iron-binding metabolites. The mean percent dose excreted in urine in the form of the parent drug was 45 +/- 10% and 10 +/- 2% (means +/- SD) in the form of metabolites. Of the total amount of the parent drug infused, 3 h after initiation, 87% was in the form of DFO, whereas 13% was present as the DFO-iron III complex which represented 45 mg of urinary iron elimination. The described DFO infusion protocol provides for sufficient DFO to chelate significant amounts of ferric iron in excess of normal levels, thus allowing experimental studies of iron chelation in a variety of disease states.  相似文献   
15.
The qualities of daughter versus same-sex friend relationships were described by 151 married and widowed elderly women. The relation of these qualities to life satisfaction was assessed. Relationship qualities predicted life satisfaction in widowed women but not in married women. Significant predictors of life satisfaction for widows included the emotional support of daughters, the instrumental support of friends and friendship strength. In a comparison of the relationship qualities, both married and widowed respondents described daughters as providing more stimulation, ego support and utility than friends. Respondents also reported that relationships with daughters were stronger than those with friends. Married women described relationships with both daughters and friends as more stimulating than widowed women. The value of assessing qualitative indices compared to quantitative indices of later life relationships is discussed.  相似文献   
16.
17.
18.
Low-income minority patients from East St. Louis, Illinois, a depressed midwestern urban city, who had visited acute care settings with asthma symptoms, participated in a focus group. Questions were constructed around the Health Belief Model to characterize participants' experiences in receiving asthma care, their confidence in long-term asthma self-management, barriers they perceived to managing their asthma, and recommendations they would make for improving asthma care in their community. Analysis of comments suggests an appreciable understanding of asthma triggers, limited coping behaviors for asthma symptoms, very limited practice of active asthma management, perception of the health care system as frequently insensitive to their needs or their knowledge of their own care, exchange of well-articulated information regarding how to deal with the system, and an apparent lack of awareness of any potential contribution of patient education or support system.  相似文献   
19.
Neutrophil bactericidal activity was assessed in patients with type 1 (n=45) and Type 2 diabetes mellitus (n=68) and non-diabetic control subjects (n=40) by measurement of whole blood chemiluminescence. Though chemiluminescence values tended to be highest in the non-diabetic subjects these differences were not statistically significant (mean ± SD) (2.73 ± 1.65 mV (controls), 2.33 ± 1.41 mV (Type 1 diabetes) and 2.38 ± 1.12 mV (Type 2 diabetes), F=1.12, p=0.33). Significant negative correlations were evident, however, in patients with both Type 1 and Type 2 diabetes between chemiluminescence and glycated haemoglobin (rs=-0.35, p=0.005 (Type 1), rs=-0.45, p=0.002 (Type 2), fructosamine (rs=-0.36, p=0.003 (Type 1), rs=-0.42, p=0.004 (Type 2)), and random blood glucose (rs=-0.25, p=0.04 (Type 1), rs=-0.48, p=0.001 (Type 2)). Changes in whole blood chemiluminescence in a further group of 10 patients with Type 2 diabetes mellitus commenced on insulin therapy were followed for 21 days. Serum fructosamine concentrations fell significantly over this time (524 ± 58 μmol l?1 to 405 ± 47 μmol l?1, p<0.001), however, although chemiluminescence values tended to rise these changes were not statistically significant (1.01 ± 0.38 mV to 1.60 ± 0.91 mV, S=4.24, df=5, p=0.52). These results suggest that impaired neutrophil bactericidal function is associated with poor blood glucose control. While it is likely that neutrophil bactericidal function will improve as blood glucose control improves, further studies are required both to confirm this and to demonstrate a reduction in the incidence of clinical bacterial infection.  相似文献   
20.
For almost three decades, many have regarded general hospital psychiatric units as the most appropriate setting for acute treatment of persons with serious mental illness who were once treated mostly in state hospitals. The extent to which this transfer has taken place and the differences between public and private general hospitals have been unclear. Using data from the 1988 National Mental Health Facilities Study and published data from the 1970s, the authors found that nearly half of all general hospitals providing psychiatric services treat persons with serious mental illness. Significant differences in case and payer mix were observed between public and private general hospitals, although these differences were smaller than in the 1970s. The findings suggest increased involvement by private general hospitals in treating patients reimbursed by public payers, but the findings also indicate that persons with serious mental illness and those using Medicaid are still more prevalent in public general hospitals than in private ones.  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