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   4517篇
  免费   336篇
  国内免费   57篇
耳鼻咽喉   48篇
儿科学   146篇
妇产科学   128篇
基础医学   647篇
口腔科学   156篇
临床医学   430篇
内科学   1089篇
皮肤病学   90篇
神经病学   328篇
特种医学   267篇
外科学   409篇
综合类   53篇
预防医学   419篇
眼科学   46篇
药学   244篇
中国医学   17篇
肿瘤学   393篇
  2023年   29篇
  2022年   54篇
  2021年   91篇
  2020年   53篇
  2019年   103篇
  2018年   93篇
  2017年   87篇
  2016年   95篇
  2015年   142篇
  2014年   192篇
  2013年   211篇
  2012年   243篇
  2011年   235篇
  2010年   152篇
  2009年   147篇
  2008年   190篇
  2007年   236篇
  2006年   211篇
  2005年   206篇
  2004年   180篇
  2003年   207篇
  2002年   181篇
  2001年   127篇
  2000年   161篇
  1999年   111篇
  1998年   64篇
  1997年   66篇
  1996年   43篇
  1995年   56篇
  1994年   38篇
  1993年   39篇
  1992年   90篇
  1991年   78篇
  1990年   62篇
  1989年   73篇
  1988年   60篇
  1987年   45篇
  1986年   55篇
  1985年   45篇
  1984年   35篇
  1983年   30篇
  1982年   25篇
  1980年   17篇
  1979年   16篇
  1976年   23篇
  1975年   13篇
  1971年   14篇
  1970年   16篇
  1967年   13篇
  1966年   15篇
排序方式: 共有4910条查询结果,搜索用时 38 毫秒
11.
To determine the therapeutic activity on regional myocardial function of nifedipine intravenous administration (0.16 mg/kg) during short term myocardial induced ischemia, we used 6 mongrel dogs anesthetized and intubated those who we have implanted 3 pairs of ultrasonic crystals in the subendocardial layer. Utilizing an open chest canine model we performed total 1 minute and partial 2 minutes 30 seconds alternative obstructions, controlled with electromagnetic flowmeters in the anterior descending (AD) and circumflex (Cx) coronary arteries before and after drug administration. During the 70-80% obstructions we have shown a significant improvement in segment shortening, reduced by ischemia, in the ischemic and peri-ischemic zone. The ischemic markers, per cent increment of end diastolic length (% IEDL) and per cent increment of end systolic length (% IESL), have shown significant improvement during partial obstructions in the ischemic and peri-ischemic zone. After total obstructions the improvement on regional myocardial function is less marked and limited to ischemic zone.  相似文献   
12.
Factors influencing women to undergo screening mammography   总被引:2,自引:0,他引:2  
  相似文献   
13.
14.
Primary deficiency of surfactant is responsible for the respiratory distress syndrome and concerns premature neonates born before 33 weeks of gestation. However, newborns may develop respiratory disorders related to a secondary deficiency or dysfunction of surfactant. We report the course of three extremely low birth weight premature infants who experienced clinical respiratory decompensation at two weeks and showed a marked improvement after exogenous natural surfactant administration.  相似文献   
15.
The effects of staphylococci-induced experimental wasting disease on the immune response of 1 month old CD1 mice were investigated. Animals were separated into different subgroups in order to study their cellular immune competence. Malnutrition of wasted mice was associated with anorexia, diarrhea and weakness. Footpad-injected splenic cells produced normal graft vs. host (GvH) reactions in the popliteal lymph nodes of F1 hybrids. In other experiments, the SRBC intragastric feeding of wasted mice did not cause a tolerant anti-erythrocyte humoral immune response. Three weeks after the staphylococci injections, convalescent erythrocyte-fed wasted mice exhibited an anti-SRBC PFC production similar to that observed in non-tolerant immunized control healthy mice. In return, healthy SRBC-fed control mice showed the specific attenuation of antibody response characteristics of oral tolerance. Differences were found between the immune competence of the undernourished staphylococci-treated wasted mice and those shown by other authors in protein-depleted mice.  相似文献   
16.
The biophysical properties of non-eczematous skin at three locations in atopics and non-atopics were characterized using non-invasive physical methods. Skin friction was measured with a newly developed sliding friction instrument, the degree of hydration with a capacitance meter (Corneometer CM 820), and the transepidermal water loss (TEWL) was determined using an Evaporimeter EP1. The areas examined (dorsum of the hand, volar forearm and lower back) showed lower values of friction and capacitance in the atopic patients than did corresponding sites in the normal controls. In most areas a significant correlation between friction and capacitance was found. The TEWL was increased in atopic skin, but TEWL seems to correlate neither to friction nor to capacitance.  相似文献   
17.
Chronic bronchitis, as defined by the magnitude and duration of sputum production, is a diagnosis that encompasses a variety of patients with physiological abnormalities ranging from mild to severe. The first element of therapy is the cessation of smoking, the single most frequent cause of chronic bronchitis. In assisting patients to stop cigarette abuse, nicotine-containing gum has been useful. Therapy directed at airway narrowing continues to be the most widely prescribed. The use of metered dose inhalers containing either beta-adrenergic stimulants or, more recently, ipratropium bromide, an atropine-like agent, continues to be the mainstream of therapy. Theophylline remains a widely prescribed bronchodilator. The use of corticosteroids remains controversial in the stable patient, but appears to be indicated clearly in the patient with an acute exacerbation. The usefulness of antibiotics in acute exacerbations is still uncertain; further studies are needed. Augmentation of survival by the use of chronic supplemental O2 is now certain; more efficient ways to administer O2 are now available. Finally, pulmonary rehabilitation provides a means of improving quality of life in severely disabled patients.  相似文献   
18.
19.
To determine whether thirst mechanisms are altered in nondiabetic patients with chronic renal failure on hemodialysis, 4 patients with an average weight gain between dialysis sessions of more than 5% of dry body weight (group I), 5 patients with less than 3% weight gain (group II), and a group of 6 healthy subjects (group III) were submitted to infusion of hypertonic saline. After infusion the subjects had free access to water. Thirst was evaluated by visual analogue rating scales. Despite similar increments of effective plasma osmolality during saline infusion, patients of group I were thirstier than groups II and III (p less than 0.005 and p less than 0.01, respectively). Changes in thirst ratings were similar in groups II and III. Osmotic thresholds for thirst onset were similar in groups II and III (288.9 +/- 8.5 and 289.8 +/- 3.4 mosm/kg, respectively), but lower in group I (277.6 +/- 7.6 mosm/kg). Nevertheless, great variations were observed in the latter group. Thus, 2 patients showed thresholds for thirst within the normal range, whereas the others had low osmolar thresholds for thirst and baseline plasma osmolalities and high basal thirst scores. During the drinking period, the patients of group I drank more (14.2 +/- 2.8 ml/kg) than those of groups II (5.3 +/- 1.6 ml/kg; p less than 0.02) and III (10.2 +/- 1.6 ml/kg; n.s.) The plasma levels of angiotensin II in uremic patients were higher than in healthy subjects, although there were no differences between groups I and II and no correlation between basal angiotensin II levels and the interdialytic weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
20.
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