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   7150篇
  免费   290篇
  国内免费   32篇
耳鼻咽喉   179篇
儿科学   236篇
妇产科学   190篇
基础医学   1058篇
口腔科学   90篇
临床医学   389篇
内科学   1479篇
皮肤病学   71篇
神经病学   750篇
特种医学   287篇
外科学   780篇
综合类   88篇
预防医学   537篇
眼科学   167篇
药学   701篇
中国医学   27篇
肿瘤学   443篇
  2023年   28篇
  2022年   76篇
  2021年   163篇
  2020年   76篇
  2019年   123篇
  2018年   140篇
  2017年   126篇
  2016年   136篇
  2015年   158篇
  2014年   230篇
  2013年   256篇
  2012年   489篇
  2011年   491篇
  2010年   255篇
  2009年   202篇
  2008年   423篇
  2007年   486篇
  2006年   495篇
  2005年   487篇
  2004年   474篇
  2003年   457篇
  2002年   345篇
  2001年   77篇
  2000年   67篇
  1999年   75篇
  1998年   40篇
  1997年   44篇
  1996年   35篇
  1995年   33篇
  1994年   29篇
  1993年   32篇
  1992年   59篇
  1991年   47篇
  1990年   46篇
  1989年   51篇
  1988年   41篇
  1987年   40篇
  1986年   40篇
  1985年   28篇
  1984年   46篇
  1983年   37篇
  1982年   27篇
  1979年   31篇
  1977年   27篇
  1975年   26篇
  1974年   26篇
  1973年   25篇
  1967年   25篇
  1965年   22篇
  1932年   21篇
排序方式: 共有7472条查询结果,搜索用时 171 毫秒
1.
2.
3.
4.
BACKGROUND: Incisional hernia is a common problem following Roux-en-Y gastric bypass for morbid obesity. PATIENTS AND MATERIALS: We report the preliminary results of nonrandomized prophylactic use of polypropylene mesh in a group of 60 consecutive patients. The patients with highest body mass index, and/or history of abdominal hernias and profound liver damage had abdominal wall reinforced with mesh during an operation. A year later the wound was assessed in all patients. RESULTS: In standard wound closure group (n=48) incisional hernia was found in 9 cases (20%). None of the patients with inserted mesh (n=12) developed hernia. The length of hospital stay in mesh group was similar to that in the nonmesh group and shorter than in patients with hernia occurrence. Mesh insertion was complicated with wound discharge in three patients. CONCLUSIONS: In our opinion prophylactic use of polypropylene mesh in bariatric patients is highly effective in postoperative hernia prevention.  相似文献   
5.
There is no published data about associations between the state of dentition and bone mass in adolescents. The objective of this study was to investigate whether the prevalence of caries and dental malocclusion is associated with bone mass during growth. In 123 healthy Caucasian subjects (72 males, 51 females) aged 14-18 yr, DMFT figures (decayed teeth, missing teeth, filled teeth) and presence of malocclusion, according to Angle classification, were determined. Participants completed a questionnaire regarding dental hygiene, physical activity level, and consumption of sweets. Anthropometry and pubertal stages were examined. Bone mineral density (BMD) was examined using dual energy X-ray absorptiometry (DXA) in the total body, head, and lumbar spine. No association was found between DMFT (mean+/-SD: 8.33+/-3.9) and BMD or Z-scores for BMD. Malocclusion was found in 49 subjects (39.8%) and was more prevalent in females than males. Malocclusion was associated with lower total BMD independently of body size (p=0.001; Z-scores: -0.21+/-0.27 vs +0.33+/-0.17; p=0.1) in males (but not females), producing odds ratio 1.6 (95% confidence interval: 1.09-2.34%; p=0.02). Head BMD was also lower in the males with malocclusion than in those without (p=0.004). Neither caries nor the tooth loss appear to be associated with BMD during growth. Boys with malocclusion are at higher risk of reduced BMD. This suggests that inadequate bone mass accrual in males coexists with impaired growth of the masticatory system in childhood and adolescence, however, the causal pathway is unknown. Factors that produce malocclusion may also affect bone mass or size but further prospective studies are needed to evaluate the relationship.  相似文献   
6.
The results of bacteriological tests of Palacos R cement with antibiotic 4 days, 7 days, 2 weeks, 3 weeks and 4 weeks after implantation in rabbit organism have been presented in this work. The results of tests of mechanical characteristics of cement with and without antibiotic samples after being kept in physiological saline for 3 to 6 weeks have also been discussed. Bacteriological tests prove that antibiotic (III generation cephalosporin) added to surgical cement retain its bacteriostatic properties. When tested on rabbits cement plus antibiotic retains its bacteriostatic properties after 4 weeks period. It has state, that by reason of prolonged time of activity antibiotic into surgical cement, it is necessary to investigate the mechanical characteristics of cement conditioned in physiological saline for 3 months at least.  相似文献   
7.
M Balázs  G Vadász  I Koncz  E Simon 《Orvosi hetilap》1991,132(39):2143-2146
15 patients with congestive gastropathy were reported including clinical and pathological characteristics of the disease. Every patient had alcoholic liver cirrhosis and portal hypertension. 6 patient's stomach was resected while in 2 further cases the disease was found at autopsy. In additional 7 cases the characteristic microvascular changes were observed in endoscopic biopsy specimens from the gastric mucosa. The authors presume that this disease has an acute and a chronic stage. In the acute stage dilated capillaries are present under the surface, not related to the inflammation of gastric mucosa. This phenomenon was described in the literature. In the chronic stage there are dilated and tortuous vessels in the submucosal layer surrounded by collagenous connective tissue. The authors suppose that the thick and fibrotic submucosal layer causes microcirculatory disturbances in the gastric mucosa. The impaired microcirculation may cause extensive ulcers with profuse and sometimes lethal bleeding.  相似文献   
8.
Purpose of work was estimation of the results of treatment of pseudoarthrosis of the long bone with the method of decortication, with use of autogenic bone depends on kind of pseudoarthrosis and kind of osteosynthesis. In the years 1995-2005 56 patients were treated because of pseudoarthrosis of long bone in our Clinic. Pseudoarthrosis is classified according to Weber-Cech classification. In the methodology of clinical estimation and subjective estimation of the patient Stewart and Hundley and Anderson classification were used. Union was achieved in 51 cases. Time of bone union achievement was 5 months. The results of treatment are depends on morfology of pseudoartrosis and are independs of kind of osteosynthesis.  相似文献   
9.
10.
Plasma autoantibodies (aAbs) against the oxidized DNA base derivative 5-hydroxymethyl-2'-deoxyuridine (5-HMdU) are potential biomarkers of cancer risk and oxidative stress. We examined their association with a number of cancer risk factors: smoking, alcohol habits, body fatness, and absence of the glutathione S-transferases M1 and T1 (GSTM1 and GSTT1) in a sample from the population-based Malm? Diet and Cancer cohort (Sweden). This was a cross-sectional study of 264 men and 280 women, 46-67 years of age. Anti-5-HMdU aAb concentration was determined by an ELISA. Data on tobacco exposure were collected through a questionnaire. Alcohol consumption was estimated by a modified diet history method. Body fatness was assessed by a bioimpedance method. The absence or presence of genes coding for GSTM1 and GSTT1 was determined in granulocyte DNA by a multiplex PCR technique. aAb titers were significantly greater in those with high alcohol consumption. Current smokers lacking GSTM1, particularly men, had greater aAb titers compared with nonsmokers or persons expressing GSTM1. Body fatness was inversely associated with antibody titers in men. GSTT1 genotype was not associated with aAb titers. Overall, women had higher aAb titers than men. Adjustment for potential confounders (history of chronic diseases, anti-inflammatory medication, and season of blood sampling) did not change the results. Our study shows that a high alcohol consumption, smoking in combination with lack of GSTM1, and low body fatness (in men) is associated with high titers of anti-5-HMdU aAbs in this population.  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