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   4617篇
  免费   264篇
  国内免费   22篇
耳鼻咽喉   76篇
儿科学   103篇
妇产科学   58篇
基础医学   726篇
口腔科学   77篇
临床医学   426篇
内科学   976篇
皮肤病学   67篇
神经病学   367篇
特种医学   188篇
外科学   855篇
综合类   63篇
一般理论   5篇
预防医学   283篇
眼科学   76篇
药学   283篇
中国医学   8篇
肿瘤学   266篇
  2023年   19篇
  2022年   30篇
  2021年   72篇
  2020年   63篇
  2019年   76篇
  2018年   65篇
  2017年   69篇
  2016年   73篇
  2015年   76篇
  2014年   123篇
  2013年   197篇
  2012年   243篇
  2011年   295篇
  2010年   169篇
  2009年   164篇
  2008年   292篇
  2007年   296篇
  2006年   296篇
  2005年   283篇
  2004年   285篇
  2003年   285篇
  2002年   260篇
  2001年   55篇
  2000年   54篇
  1999年   52篇
  1998年   62篇
  1997年   55篇
  1996年   53篇
  1995年   52篇
  1994年   47篇
  1993年   35篇
  1992年   45篇
  1991年   45篇
  1990年   48篇
  1989年   49篇
  1988年   42篇
  1987年   40篇
  1986年   37篇
  1985年   35篇
  1984年   36篇
  1983年   30篇
  1982年   21篇
  1981年   26篇
  1980年   22篇
  1979年   17篇
  1978年   21篇
  1976年   13篇
  1975年   15篇
  1974年   13篇
  1973年   24篇
排序方式: 共有4903条查询结果,搜索用时 15 毫秒
81.
A relation between anxiety disorders and balance control dysfunctions has been observed in many studies in humans. A mismatch in the integration of sensory inputs could trigger these disturbances. Very few experimental animal procedures have been designed to study the functional link between anxiety and balance control. A task was therefore developed, challenging the visual, vestibular and somesthesic sensory systems in mice. The test, called the 'rotating beam', gave an accurate assessment of balance control and the posture, using sensitive measures (number of falls and imbalances, position of tail and trunk). Striking differences were observed between the two inbred strains of mice known to have radically different anxiety-related behaviour. The highly anxious strain, BALB/cByJ, performed poorly compared to the non anxious strain, C57BL/6J. Balance control and postural abilities of anxious mice were improved by acute anxiolytic diazepam treatment. Lower behavioural performance level was registered in non anxious mice given anxiogenic beta-CCM treatment. The findings account for a strong relationship between anxiety and balance control in mice. Finally, the highly sensitive procedure proved to be well suited to the study of functional links between anxiety and sensorimotor processes.  相似文献   
82.
83.
The small intestine is the major site of drug absorption. Some reports in the literature have evoked the concept of “absorption windows” in the small intestine: are there specific regions where drug absorption is significantly higher than others? To investigate this question, we used an everted gut sac method to study the permeability of drugs and markers every 3–4 cm down the entire small intestine in rat. These markers were chosen to be representative of the mechanisms by which drugs cross the small intestinal mucosa: paracellular and transcellular passive diffusion, via influx transporters, and a drug (digoxin) that is effluxed from cells by P-glycoprotein (P-gp). The passive diffusion and influx transporter markers gave similar profiles with a plateau of permeability along the jejunum, and with the exception of L-Dopa, lower permeability in the ileum. Digoxin showed a linear decrease in the profile from the proximal jejunum to the ileum. Permeability in the duodenum was two to three times lower than the jejunum for all compounds. There were no narrow specific regions of high permeability and so the concept of discrete “absorption windows” along the small intestine as suggested from some pharmacokinetic studies may be related to other effects such as pH and/or solubility.  相似文献   
84.
Infection by Toxocara canis can cause systemic vasculitis. We report here a unique case of systemic lupus erythematosus (SLE) triggered by T. canis infection. An 8‐year‐old girl was treated with albendazole therapy for common toxocariasis, but she developed two weeks later, asthenia, fever, infiltrated maculopapular eruption of the face, peripheral vascular disease with necrosis of the fingers and inflammatory anemia with proteinuria. Anti‐nuclear, anti‐DNA and anti‐Sm antibodies positivity, together with minimal change nephritis with mesangial exclusive IgM deposit on renal biopsy and clinical relapse after initially successful steroid therapy, led to the diagnosis of SLE. T. canis infection can trigger systemic lupus but must also be ruled out of the differential diagnosis given its association with autoimmunity.  相似文献   
85.
86.
To facilitate the design of effective policies that can address adolescent's reproductive health problems, it is necessary to gain a thorough understanding of patterns of adolescents' sexual behavior, and the factors that affect them. Using a unique set of data collected in 2004 from a nationally-representative survey of adolescents, this study examines adolescents' risky and protective sexual behavior in Burkina Faso. Findings show that 11% of adolescent males had sexual intercourse in last twelve months with more than two partners but did not use condoms. Logistic regression analysis shows that the odds of using condoms increased with years of schooling and self-efficacy in use of condoms. Females who were very confident of getting a male partner to wear a condom were six times more likely to have used a condom at last sex than those who were not confident at all.  相似文献   
87.
Background: Metastatic breast cancer is generally believed to be associated with a poor prognosis. Therapeutic advances over the past two decades, however, have resulted in improved outcomes for selected patients with limited metastatic disease. Methods: Between March 1991 and October 2002, 31 patients had hepatic resection for breast cancer metastases limited to the liver. Clinical and pathologic data were collected prospectively from breast and hepatobiliary databases. Results: Median age of patients was 46 years (range, 31 to 70). Liver metastases were solitary in 20 patients and multiple in 11 patients. Median size of the largest liver metastasis was 2.9 cm (range, 1 to 8). Major liver resections (three or more segments resected) were performed in 14 patients, whereas minor resections (fewer than three segments resected) with or without radiofrequency ablation (RFA) were performed in 17 patients. No postoperative mortality occurred. Of the 31 patients, 27 (87%) received either preoperative or postoperative systemic therapy as treatment for metastatic disease. The median survival was 63 months; a single patient died within 12 months of hepatic resection. The overall 2- and 5-year survival rates were 86% and 61%, respectively, whereas the 2- and 5-year disease-free survival rates were 39% and 31%, respectively. No treatment- or patient-specific variables were found to correlate with survival rates. Conclusions: In selected patients with liver metastases from breast cancer, an aggressive surgical approach is associated with favorable long-term survival. Hepatic resection should be considered a component of multimodality treatment of breast cancer in these patients.  相似文献   
88.
89.
90.
Accurate age determination is fundamental in both forensic medicine and anthropology. Many methods that relate dental characteristics to adult age have been proposed, but there is still no simple and reliable method that does not damage the study material. The aim of this work was to propose a relevant and practical technique for determining age in adults that could be used in both living and deceased individuals. The sample was composed of 210 CT scans from individuals aged from 15 to 85 years old, with four healthy canines present in the mouth. The 840 canines were modelled using Mimics® 10.01 software. The pulp volume/total volume ratio ×100 was determined for each tooth. Seven mathematical models, corresponding to all possible real situations, were determined by the weighted least squares method and ranked in order of relative performance. The adequacy of the seven models to the data was very high with the regressions proposed (0.915?<?R 2 adjusted?<?0.964). Ranked in order of performance, the maxillary model was the most powerful of the seven models for age determination, followed by the 4 canines model, the 13 model and the 23 model.  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