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   885篇
  免费   42篇
  国内免费   24篇
耳鼻咽喉   9篇
儿科学   80篇
妇产科学   28篇
基础医学   147篇
口腔科学   12篇
临床医学   75篇
内科学   140篇
皮肤病学   11篇
神经病学   79篇
特种医学   21篇
外国民族医学   2篇
外科学   119篇
综合类   22篇
预防医学   70篇
眼科学   7篇
药学   81篇
中国医学   1篇
肿瘤学   47篇
  2022年   7篇
  2021年   13篇
  2019年   14篇
  2018年   10篇
  2017年   14篇
  2016年   15篇
  2015年   10篇
  2014年   20篇
  2013年   31篇
  2012年   34篇
  2011年   40篇
  2010年   23篇
  2009年   14篇
  2008年   34篇
  2007年   58篇
  2006年   44篇
  2005年   50篇
  2004年   54篇
  2003年   29篇
  2002年   42篇
  2001年   55篇
  2000年   45篇
  1999年   28篇
  1998年   10篇
  1997年   11篇
  1996年   12篇
  1995年   6篇
  1994年   7篇
  1993年   7篇
  1992年   14篇
  1991年   10篇
  1990年   7篇
  1989年   23篇
  1988年   13篇
  1987年   14篇
  1986年   11篇
  1985年   8篇
  1984年   13篇
  1983年   8篇
  1981年   6篇
  1978年   4篇
  1976年   8篇
  1975年   6篇
  1974年   4篇
  1973年   5篇
  1972年   4篇
  1971年   4篇
  1970年   6篇
  1967年   4篇
  1936年   4篇
排序方式: 共有951条查询结果,搜索用时 31 毫秒
1.
2.
P Berner 《Psychopathology》1991,24(5):297-303
Polydiagnostic follow-up studies should explore whether certain definitions of a given disorder permit better prediction of the illness course than others and whether this good predictive validity is related to specific etiopathogenetic conditions. In order to carry out such studies successfully they should be based on broadly defined samples and comprise provisions for additional validation such as genetic data, neuropsychological testing etc. After an assessment at baseline and at discharge from hospital, the follow-up assessments should comprise five steps: (1) Identification of successful and unsuccessful diagnostic systems; (2) identification of features determining successful attribution; (3) analysis of successful systems; (4) analysis of unsuccessful systems, and (5) analysis of cases which have changed diagnostic attribution. The conclusions drawn from these analyses are intended to refine classification in psychiatry.  相似文献   
3.
4.
An open trial was carried out in eight healthy male and female volunteers to examine the bioavailability as well as the main kinetic parameters of Migr?nerton (metoclopramide and paracetamol; CAS 364-64-5 and CAS 103-90-2, resp). in comparison with reliable literature data. The results reported here clearly show that the absorption of both active ingredients from the fixed combination is complete and that therapeutically relevant plasma concentrations are achieved within 30 min. Bioavailability as well as tmax, t1/2, and time-lag are comparable with data resulting from reliable and internationally acknowledged kinetic studies. The fixed combination was shown to be kinetically compatible with regard to all parameters determined for metoclopramide and paracetamol.  相似文献   
5.
6.
The solution properties of aqueous ethanol donor solutions were characterized for the particular case of an increased flux nitroglycerin transdermal system. Permeation through porous and nonporous polymer membranes was investigated and modelled. While the permeation of ethanol through the porous membranes is adequately described by theory, clogging of pores occurs in the presence of lactose. Permeation through ethylene vinyl acetate membranes reflects interactions of the solute and solvent with the polymer.  相似文献   
7.
8.
PURPOSE: To develop and evaluate a model for assessing information retrieval and application skills, and to compare the performances on the assessment exercises of students who were and were not instructed in these skills. METHOD: The authors developed a set of four examination stations, each with multiple subtasks, and administered the exams to students at two medical schools. Students at one school had intensive instruction in literature searching and filtering skills for information quality (instructed group), and those at the other school had minimal instruction in these areas (uninstructed group). The stations addressed pediatrics content and the skills of searching Medline and the World Wide Web, evaluating research articles, evaluating the accuracy of information from the Web, and using the information to make recommendations to patients. The authors determined the psychometric characteristics of the stations and compared the performances of the two groups of students. RESULTS: Students in the instructed group performed significantly better and with less variability than the uninstructed group on four tasks and no differently on seven tasks. There was no task on which the uninstructed group performed significantly better than the instructed group. CONCLUSION: The prototype stations showed predictable differences across curricula, indicating that they have promise as assessment tools for the essential skills of information retrieval and application.  相似文献   
9.
The relationship between pK a and skin irritation in man is studied for a homologous series of benzoic acid derivatives, which permeate through human skin at comparable rates (15–88 µg/cm2/hr). Skin irritation and pK a are correlated for pK a 4. Laser Doppler velocimetric assessment of skin blood flow, color meter readings, erythema, edema, and the primary irritation index are all linearly correlated and related to pK a, erythema at 24 hr appears to be the most sensitive parameter to variation in pK a when pK a 4.  相似文献   
10.
The TP53 gene mutation pattern in prostatic cancer was examined in relation to progression and survival, using archival formalin-fixed pre-and post-treatment tumour specimens from 84 prostatic cancer patients. Thirty-four had hormone-sensitive tumours and 50 were hormone-resistant. Six of the 34 (18 per cent) therapy-responding tumours and 19 of the 50 (38 per cent) hormone-resistant tumours showed p53 protein accumulation in the post-treatment specimen. Both pre- and post-treatment specimens from these 25 patients were analysed for mutation of the conserved regions of the TP53 gene (exons 5–8), using constant denaturant gel electrophoresis (CDGE) followed by DNA sequencing. In the post-treatment samples, mutations were detected in three of the six patients with hormone-responsive tumours and in 11 of the 19 patients with hormone-resistant tumours. The three (100 per cent) patients with therapy-responsive tumours with mutations and nine of the 11 (82 per cent) patients with therapy-resistant tumours with mutations died of the disease. Thirteen of the 14 mutations in the post-treatment specimens were transitions, 11 occurring at CpG dinucleotides in which codon 273 was involved in ten. A significantly higher proportion of tumours with mutations were poorly differentiated compared with tumours without mutation (P<0·04). Our findings indicate that TP53 mutation is a late event in tumour development of the prostate gland and that codon 273 might be a ‘hotspot’ for mutation in the progression of the disease.  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