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   3770篇
  免费   239篇
  国内免费   61篇
耳鼻咽喉   13篇
儿科学   149篇
妇产科学   109篇
基础医学   439篇
口腔科学   132篇
临床医学   353篇
内科学   863篇
皮肤病学   56篇
神经病学   295篇
特种医学   281篇
外科学   471篇
综合类   33篇
一般理论   1篇
预防医学   243篇
眼科学   36篇
药学   264篇
中国医学   7篇
肿瘤学   325篇
  2023年   13篇
  2022年   14篇
  2021年   70篇
  2020年   46篇
  2019年   65篇
  2018年   79篇
  2017年   60篇
  2016年   61篇
  2015年   107篇
  2014年   127篇
  2013年   186篇
  2012年   181篇
  2011年   211篇
  2010年   140篇
  2009年   111篇
  2008年   149篇
  2007年   199篇
  2006年   136篇
  2005年   152篇
  2004年   169篇
  2003年   155篇
  2002年   129篇
  2001年   132篇
  2000年   159篇
  1999年   118篇
  1998年   60篇
  1997年   60篇
  1996年   35篇
  1995年   48篇
  1994年   43篇
  1993年   40篇
  1992年   81篇
  1991年   72篇
  1990年   56篇
  1989年   67篇
  1988年   53篇
  1987年   38篇
  1986年   56篇
  1985年   30篇
  1984年   34篇
  1983年   33篇
  1982年   25篇
  1981年   16篇
  1980年   14篇
  1979年   23篇
  1977年   17篇
  1976年   16篇
  1970年   13篇
  1969年   23篇
  1968年   13篇
排序方式: 共有4070条查询结果,搜索用时 875 毫秒
1.
2.
氟喹诺酮类药物不良反应168例分析   总被引:12,自引:0,他引:12  
施玲玲 《医学争鸣》2005,26(6):531-531
0 引言 随着氟喹诺酮类药物在临床的广泛应用,有关其应用所致不良反应的报道也日趋增多,我们通过对1990/2003年我院氟喹诺酮类药物不良反应情况报告如下,供临床参考。  相似文献   
3.
Milos Jesenak  MD  PhD    Peter Banovcin  MD  PhD    Zuzana Rennerova  MD  PhD    Lubica Jakusova  MD  PhD    Zuzana Havlicekova  MD  PhD    Vladimir Pohanka  MD  PhD  MPH  FCCP    Maria Pia Villa  MD  PhD    Roberto Ronchetti  MD  PhD 《International journal of dermatology》2009,48(9):941-946
Background  The atopy patch test (APT) is no longer an experimental method; it is increasingly being used as a standard diagnostic tool for the characterization of patients with aeroallergen- and food-triggered disorders. Some technical aspects of this test still remain to be answered. We aimed to study the reproducibility of this test over time in the general child population.
Methods  In a general population of 118 children, we investigated the reproducibility of duplicate APTs with four food allergens in their native form, which were repeated at set intervals from the first test: 7 days (group 1), 14 days (group 2), and 21 days (group 3).
Results  We observed very poor reproducibility on both sides of the back in all three studied subgroups. The reproducibility rates and Cohen's κ values did not improve when we did not consider the side of the back. There were no differences in the prevalence of atopy between the subjects with reproducible and nonreproducible APT results. All three groups studied showed no difference in the prevalence rates of atopy. There was no relationship between APT and skin prick test positivity for the same allergen. Questionnaire-derived data about previous food-related reactions did not help in the evaluation of the doubtful nonreproducible APT results with food allergens.
Conclusions  Our results show that the reproducibility of food APTs is poor and unsatisfactory over time, and there is an urgent need for the development of optimal, stable, and good-quality APT testing substances.  相似文献   
4.
Abstract Caries experience and enamel fluorosis prevalence in 8-year-old children belonging to different socio-economic classes were determined in two Chilean twin cities that are served by optimally fluoridated community water from the same waterworks facility. Low socio-economic status (LSES) children had a higher mean dm ft and DMFT indices (P<0.001) than high socioeconomic status (HSES) children. Prevalence of enamel fluorosis in the permanent teeth of LSES children was 0.79, significantly higher (X2= 9.0; P<0.003) than the value 0.59 found in HSES children. The proportion of Dean's scores 2. 3, 4 and 5 in first molars, mandibular and maxillary incisors in LSES children was higher than in HSES children (P<0.001). Differences in prevalence and seventy of enamel fluorosis between both groups are tentatively attributed lo a different pattern of tap water and tea consumption at pre-school ages. Suggestions are advanced to minimize the undesirable prevalence and severity of enamel fluorosis.  相似文献   
5.
6.
To examine the relationship between demographic, clinical and psychosocial variables and diabetes self-care management in Mexican type 2 diabetic patients. Cross-sectional study of 176 consecutive patients with type 2 diabetes aged 30-75 years, attending a tertiary health-care center in Mexico City. A brief medical history and previously validated questionnaires were completed. The study group consisted of 64 males/112 females, aged 55 +/- 11 years, mean diabetes duration of 12 +/- 8 years and HbA1c of 9.0 +/- 2.0%, 78.4% reported following the correct dose of diabetes pills or insulin, 58% ate the recommended food portions, and 44.3% did exercise three or more times per week. A good adherence to these three recommendations was observed in only 26.1% of the patients. These patients considered as a group were characterized by a greater knowledge about the disease (P < 0.00001), regular home blood glucose monitoring (P < 0.01), an inner perception of better diabetes control (P = 0.007), good health (P = 0.004) and better communication with their physician (P < 0.02). A poor adherence to two or the three main diabetes care recommendations was associated with a depressive state (OR 2.38, 95% CI 1.1-4.9, P < 0.01) and a history of excessive alcohol intake (OR 4.03, 95% CI 1.1-21.0, P = 0.03). Poor adherence to standard diabetes care recommendations is frequently observed in patients with type 2 diabetes attending a specialized health care center in Mexico City. Depression must be identified and treated effectively.  相似文献   
7.
BACKGROUND: The chronic course and non-specific clinical manifestations of tuberculous (TB) wrist often cause failure to make a timely diagnosis. OBJECTIVE: To better understand the rarely encountered TB wrist. PATIENTS AND METHODS: Retrospective review and analysis of cases of TB wrist between 1986 and 1997 in a medical centre in southern Taiwan. RESULTS: Thirty-seven cases (16 definitive, 13 probable and eight possible) of TB wrist (25 men, 12 women; mean age, 56.3 +/- 13.0 years) were found among a total of 4970 cases of tuberculosis. The most common presenting sign and symptom (mean duration 9.4 months) were local swelling and pain over the affected wrist. The mean white blood cell (WBC) count in peripheral blood was 7.04 x 10(9)/l, and the erythrocyte sediment rates (ESR) in seven of 31 patients who had ESR assayed were normal. Forty-six per cent of the patients had abnormal chest X-ray, and 35% had had previous manipulation of the affected wrist. CONCLUSION: Physicians should have a high index of suspicion for TB wrist among patients with chronic arthritis, even when their peripheral WBC count and ESR are normal. An abnormal chest X-ray and/or a history of previous manipulation of the affected wrist could be important clues for possible TB wrist.  相似文献   
8.
We studied NK cell function in eight patients with pathological hyperprolactinemia by measuring51Cr release by K562 cells exposed to their mononuclear cells and found it decreased compared to normal controls (P<0.01). Bromocriptine (BrC) treatment corrected NK function but also made it more efficient at 12:1 than at 25:1 or 50:1 effector:target ratios (ANOVA;P=0.01). The study of NK cell function in agarose revealed that its decrease in hyperprolactinemia is due to their low active binding to target cells, active killing, and recycling capacity. BrC tended to correct them but also increased recycling capacity to levels higher than those of controls (P<0.05). Sequential studies in three hyperprolactinemic patients before and after BrC showed correction of NK function within 1 week but its increased efficiency at the 12:1 effector:target ratio required 8 weeks. We conclude that hyperprolactinemia decreases NK cell function. BrC corrects this by decreasing prolactin levels but also makes NK function more efficient by increasing the capacity of NK cells to recycle after killing.  相似文献   
9.

Background  

Long-term morphofunctional outcome may vary widely in surgical anterior left ventricular wall restoration, suggesting variability in post-surgical remodeling similar to that observed following acute myocardial infarction. The aim of this pilot study was to demonstrate that surgical restoration obtained with a particular shape of endoventricular patch leads to steady morphofunctional ventricular improvement when geometry, volume and residual akinesia can be restored as normal as possible.  相似文献   
10.
A group of blood donors involved in post-transfusion hepatitis was investigated for the presence of the anti-HCV antibody and of HCV RNA as a more direct infection marker. RNA was extracted from serum, reverse transcribed and amplified using primers which belonged to the non structural region. The amplified product of the PCR reaction was 582 base pairs. Seven (25.9%) of the 27 blood donors examined were found anti-HCV-positive by ELISA; five (71.4%) of these were HCV RNA positive. Among the 20 anti-HCV-negative blood donors, four (20.0%) were HCV RNA positive. ALT levels were below 45 UI/l in 18 donors, while the other nine had ALTs over the limit accepted for transfusion. The anti-HCV-negative HCV RNA-positive blood donors had normal ALTs. Our study offers a direct explanation for the substantial proportion of residual cases of anti-HCV-positive post-transfusion hepatitis and suggests the necessity of creating a register of blood donors who have at some time presented blood enzyme abnormalities and for whom second level investigations such as HCV RNA should be used.  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