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   7500篇
  免费   553篇
  国内免费   29篇
耳鼻咽喉   55篇
儿科学   161篇
妇产科学   114篇
基础医学   1146篇
口腔科学   257篇
临床医学   559篇
内科学   1634篇
皮肤病学   97篇
神经病学   777篇
特种医学   268篇
外科学   1347篇
综合类   46篇
一般理论   4篇
预防医学   416篇
眼科学   108篇
药学   579篇
中国医学   8篇
肿瘤学   506篇
  2023年   44篇
  2022年   93篇
  2021年   175篇
  2020年   126篇
  2019年   164篇
  2018年   202篇
  2017年   166篇
  2016年   163篇
  2015年   185篇
  2014年   279篇
  2013年   324篇
  2012年   536篇
  2011年   546篇
  2010年   279篇
  2009年   264篇
  2008年   460篇
  2007年   437篇
  2006年   403篇
  2005年   401篇
  2004年   314篇
  2003年   325篇
  2002年   307篇
  2001年   132篇
  2000年   98篇
  1999年   102篇
  1998年   99篇
  1997年   49篇
  1996年   64篇
  1995年   52篇
  1994年   53篇
  1993年   49篇
  1992年   69篇
  1991年   88篇
  1990年   82篇
  1989年   66篇
  1988年   75篇
  1987年   62篇
  1986年   86篇
  1985年   80篇
  1984年   58篇
  1983年   46篇
  1982年   40篇
  1981年   29篇
  1980年   29篇
  1979年   40篇
  1977年   31篇
  1975年   27篇
  1974年   38篇
  1973年   40篇
  1972年   26篇
排序方式: 共有8082条查询结果,搜索用时 15 毫秒
1.
To determine percent of patients without malignancy and ≤ 40 years of age with high cumulative radiation doses through recurrent CT exams and assess imaging appropriateness. From the cohort of patients who received cumulative effective dose (CED) of ≥ 100 mSv over a 5-year period, a sub-set was identified with non-malignant disease. The top 50 clinical indications leading to multiple CTs were determined. Clinical decision support (CDS) system scores were analyzed using a widely adopted standard of 1–3 (red) as “not usually appropriate,” 4–6 (yellow) “may or may not be appropriate,” and 7–9 (green) “usually appropriate.” Clinicians reviewed patient records to assess compliance with appropriate use criteria (AUC). 9.6% of patients in our series were with non-malignant conditions and 1.4% with age ≤ 40 years. CDS scores (rounded) were 2% red, 38% yellow, 27% green, and 33% unscored CTs. Clinical society guidelines for CT exams, wherever available, were followed in 87.5 to 100% of cases. AUCs were not available for several clinical indications as also referral guidelines for serial CT imaging. More than half of CT exams were unrelated to follow-up of a primary chronic disease. We are faced with a situation wherein patients in age ≤ 40 years require or are thought to require many CT exams over the course of a few years but the radiation risk creates concern. There is a fair number of conditions for which AUC are not available. Suggested solutions include development of CT scanners with lesser radiation dose and further development of appropriateness criteria.  相似文献   
2.
3.
AimsThe aims were to 1) develop the pharmacokinetics model to describe and predict observed tanezumab concentrations over time, 2) test possible covariate parameter relationships that could influence clearance and distribution and 3) assess the impact of fixed dosing vs. a dosing regimen adjusted by body weight.MethodsIndividual concentration–time data were determined from 1608 patients in four phase 3 studies conducted to assess efficacy and safety of intravenous tanezumab. Patients received two or three intravenous doses (2.5, 5 or 10 mg) every 8 weeks. Blood samples for assessment of tanezumab PK were collected at baseline, 1 h post‐dose and at weeks 4, 8, 16 and 24 (or early termination) in all studies. Blood samples were collected at week 32 in two studies. Plasma samples were analyzed using a sensitive, specific, validated enzyme‐linked immunosorbent assay.ResultsA two compartment model with parallel linear and non‐linear elimination processes adequately described the data. Population estimates for clearance (CL), central volume (V 1), peripheral volume (V 2), inter‐compartmental clearance, maximum elimination capacity (VM) and concentration at half‐maximum elimination capacity were 0.135 l day–1, 2.71 l, 1.98 l, 0.371 l day–1, 8.03 μg day–1 and 27.7 ng ml–1, respectively. Inter‐individual variability (IIV) was included on CL, V 1, V 2 and VM. A mixture model accounted for the distribution of residual error. While gender, dose and creatinine clearance were significant covariates, only body weight as a covariate of CL, V 1 and V 2 significantly reduced IIV.ConclusionsThe small increase in variability associated with fixed dosing is consistent with other monoclonal antibodies and does not change risk : benefit.  相似文献   
4.
5.
6.
Aggressive behavior linked to corticotropin-reactive autoantibodies.   总被引:3,自引:0,他引:3  
BACKGROUND: Altered stress response is characteristic for subjects with abnormal aggressive and antisocial behavior, but the underlying biological mechanisms are unclear. We hypothesized that autoantibodies (autoAbs) directed against several stress-related neurohormones may exist in aggressive subjects. METHODS: Using enzyme-linked immunosorbent assay, we studied whether autoAbs directed against corticotropin (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), oxytocin, and vasopressin are present in serum of male subjects with conduct disorder and prisoners with history of violence. Healthy blood donors served as control subjects. RESULTS: Both conduct disorder and prisoners groups displayed strongly increased levels of ACTH-reactive immunoglobulin G (IgG) and immunoglobulin M (IgM) autoAbs compared with control subjects. Levels of oxytocin-reactive IgM autoAbs were slightly increased in both groups of aggressive subjects, whereas levels of vasopressin-reactive IgG and IgM autoAbs were lower only in conduct disorder. No differences in the levels of alpha-MSH-reactive autoAbs were found between aggressive and control subjects. CONCLUSIONS: High levels of ACTH-reactive autoAbs as well as altered levels of oxytocin- and vasopressin-reactive autoAbs found in aggressive subjects may interfere with the neuroendocrine mechanisms of stress and motivated behavior. Our data suggest a new biological mechanism of human aggressive behavior that involves autoAbs directed against several stress-related neurohormones.  相似文献   
7.
Summary Malposition of the nasal bone, septum and the alar cartilage are striking features of the unilateral cleft nose deformity. An endonasal technique (the extramucosal) was used in 26 patients, aged 13–38 (median 19), to correct aesthetic and functional problems. Twenty-four patients were secondary and two were tertiary. The patients were followed from 1–9 years. The pathological anatomy of the septum varied considerably, so different types of septoplasties had to be done. In 20 patients, satisfactory aesthetic and functional results were obtained in one operation. Secondary corrections were indicated in six patients. In cases with no gross scarring in or around the alar cartilage, the form and position of this cartilage will be more normal once the alar cartilages have been undermined and the deviation of the nasal bone and the septum is corrected.  相似文献   
8.
9.
A sample of 110 consecutive first admission young schizophrenic patients treated between 1964 and 1967 was rediagnosed in 1981. Among 92 survivors, 27 could be labelled as paraphrenics. From information available at inception 97 variables were coded covering such areas as personality, previous disturbances, age and type of onset, and symptoms around admission. Sixty-three out of 97 variables were hypothesized to differentiate, at admission, future paraphrenics from the rest of the sample. Paraphrenics were found to have had less contact disturbance, better self-esteem, less neurotic symptoms in adolescence and childhood, and less complaints of unhappiness when growing up. They had more regressive and paranoid symptoms at admission, were older at onset of the disease, which was more acute, more often connected with precipitating events, and confusion. Certain non-regressive symptoms such as brooding, anhedonia and concentration difficulties were less common. A discriminant analysis yielded a proportion of correct predictions = 0.64 (p less than 0.05). The results are in accordance with the theory of more favourable energetic and organizational capacity in paranoid schizophrenics as compared with non-paranoids.  相似文献   
10.
We would like to thank Professor Erdem Kasikcioglu for his interestin our article. In response to the initial question of why exhaustivephysical activity suppresses diastolic function,  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