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   55087篇
  免费   7168篇
  国内免费   1472篇
耳鼻咽喉   214篇
儿科学   1056篇
妇产科学   621篇
基础医学   3173篇
口腔科学   2394篇
临床医学   8714篇
内科学   5727篇
皮肤病学   788篇
神经病学   2667篇
特种医学   857篇
外国民族医学   9篇
外科学   5188篇
综合类   10089篇
现状与发展   6篇
一般理论   26篇
预防医学   5683篇
眼科学   835篇
药学   6924篇
  511篇
中国医学   5264篇
肿瘤学   2981篇
  2024年   258篇
  2023年   1286篇
  2022年   2058篇
  2021年   3406篇
  2020年   3752篇
  2019年   2768篇
  2018年   2508篇
  2017年   2831篇
  2016年   2740篇
  2015年   2387篇
  2014年   4183篇
  2013年   4503篇
  2012年   3655篇
  2011年   3706篇
  2010年   2890篇
  2009年   2530篇
  2008年   2444篇
  2007年   2492篇
  2006年   2162篇
  2005年   1774篇
  2004年   1502篇
  2003年   1339篇
  2002年   1065篇
  2001年   836篇
  2000年   664篇
  1999年   518篇
  1998年   448篇
  1997年   411篇
  1996年   344篇
  1995年   262篇
  1994年   277篇
  1993年   181篇
  1992年   210篇
  1991年   177篇
  1990年   152篇
  1989年   148篇
  1988年   140篇
  1987年   118篇
  1986年   82篇
  1985年   101篇
  1984年   86篇
  1983年   48篇
  1982年   53篇
  1981年   44篇
  1980年   47篇
  1979年   26篇
  1978年   19篇
  1977年   17篇
  1976年   23篇
  1975年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
鲁琼  叶清   《中国医学工程》2007,15(10):819-820,824
目的了解头孢菌素导致抗生素相关性腹泻的基本情况。方法对64例头孢菌素致抗生素相关性腹泻进行临床观察。结果本组头孢菌素致抗生素相关性腹泻以6个月~3岁年龄组发生率最高。其中第3代头孢菌素所致抗生素相关性腹泻的腹泻程度重于第1代。临床表现和实验室检查均缺乏特异性。结论头孢菌素致抗生素相关性腹泻比较常见,应引起临床医师在用药时的重视。  相似文献   
32.
This paper provides for the first time evidence of a consistent difference in the memory structures of novice and expert clinicians. The diagnostic performance of first- and third-year clinical medical students, senior house officers, registrars and consultants on four clinical problems in general medicine was studied. Comparisons were made of all diagnostic interpretations offered and the forceful features (personally important pieces of information which act as a key to particular memory structures which in turn give rise to the clinical interpretation) from which these were derived. Results demonstrate that the numbers of interpretations made and the numbers of forceful features identified did not differ significantly between groups (P greater than 0.05). However, the actual interpretations made in three out of four cases, and the actual forceful features identified in all cases, did differ significantly between groups (P less than 0.05). The numbers of interpretations made by all groups were large and demonstrated enormous variability. Highly individualized multiple responses to clinical information are associated with easy diagnoses. We conclude that there is no difference between groups of differing clinical experience in the breadth of thought but that there are marked differences in the precise content and structure of thought. This allows coherent explanation of variation in diagnostic expertise with clinical experience. The significance of the findings is discussed.  相似文献   
33.
Two cloned DNA fragments, one derived from an alpha satellite subfamily common to chromosomes 13 and 21, and the other derived from a similar subfamily common to chromosomes 14 and 22, have been used as biotinylated probes in in situ hybridization studies. Under high stringency conditions, chromosome specific centromeric labelling can be obtained. The applications of this technique in clinical situations are illustrated on metaphases from a fetus with trisomy 21, a fetus with trisomy 13, and a child with clinical features of cat-eye syndrome.  相似文献   
34.
This study assesses the relative importance of history, examination and investigations in paediatric diagnosis, in the Paediatric Out-patient Department of the Central Middlesex Hospital, London, by means of a questionnaire-based record of 94 consecutive referrals. A diagnosis identical to the final diagnosis was made in 76% of referrals after taking a history. The general practitioner had proposed a diagnosis in 45% in the referral letter. Clinical examination changed the diagnosis in only 15% but increased diagnostic confidence in 33%. Ninety-one per cent of cases were diagnosed without recourse to investigations. Forty-two per cent of children referred had investigations performed. In the majority of paediatric cases the provisional diagnosis reached after taking a history was identical to that after examination or results of investigations were known. Although examination provided a final diagnosis in only 15% of all cases it played an important role in adding confidence in 33%. More educational effort should therefore be directed at clinical history-taking skills and the subsequent purpose of examination.  相似文献   
35.
The purpose of this study was to examine motor learning and retention given extensive practice in two fundamentally different movement sequences. One sequence was a memory-driven task (performing a series of whole body positions from memory) and the other a context-driven task (buttoning). Practice took place over 3 weeks, with performance measured weekly; retention was measured weekly for 3 weeks after practice. There were 7 people with Parkinson's disease (PD) and 7 age-matched neurologically healthy people who participated in this study. Both groups improved performance on both tasks with practice, with the majority of the change for the PD group occurring between 1 and 2 weeks of practice. Although those with PD did not necessarily perform as well as age-matched controls, they learned both sequences in a manner similar to age-matched controls, and exhibited retention across the 3-week retention interval. If people with PD are given sufficient practice they can learn and retain both memory-based and context-driven movement sequences as well as age-matched controls. The results provide support for maintaining physical activity and for intervention through movement therapy.  相似文献   
36.
37.
Abstract Until recently, the few available chlorhexidine mouthrinse products have been 0.2% formulations. However, concentrations of 0.12% chlorhexidine appear as effective as 0.2%, if the volume of the rinse is increased to 15 ml. Since the mere incorporation of chlorhexidine in a formulation does not guarentee availability of the antiseptic, it would seem reasonable to evaluate or compare all products. This is particularly the case when other ingredients, such as fluoride are added. The 1st study compared the effect of a 0.12% chlorhexidine rinse with a 0.12% chlorhexidine/0.022% sodium fluoride rinse for effects on plaque re-growth. The study was a 7-day, blind, randomised, 2-cell cross-over design with a baseline control run in period, in which 18 subjects participated. Both chlorhexidine products significantly reduced plaque compared to control but the chlorhexidine fluoride rinse was less effective than the chlorhexidine only rinse. The 2nd study assessed the propensity of the chlorhexidine rinses to induce dietary staining in vitro. For the chlorhexidine fluoride rinse, this was less than the other 0.12% rinse and a commonly used 0.2% product. The data in vivo and in vitro suggest reduced chlorhexidine availability from the chlorhexidine fluoride product which appears to cause some loss of efficacy.  相似文献   
38.
The course and outcome of cycloid psychotic disorder was explored by means of a prospective three-year follow-up of a sample of patients fulfilling the diagnostic criteria for the disorder provided by Perris & Brockington, compared to patients with a diagnosis of affective or schizoaffective disorder. The most striking difference between cycloids and affectives was the lack of manic episodes during the follow-up period in the former group. Moreover, the mean age at onset was lower in cycloids. No difference between these patient groups was observed with regard to outcome. Compared to schizoaffectives, cycloids showed several differences in the clinical picture during the index episode, and their symptomatological pattern was more consistent from one episode to another during the follow-up. Moreover, the outcome of cycloids was significantly more favourable than that of schizodepres-sives.  相似文献   
39.
The present trial was designed to evaluate clinical scores (single observer) of sodium lauryl sulphate (SLS)-induced skin irritation in a group of subjects (n = 10) over a 10-day period along with various skin function parameters. In order to avoid significant variations due to secondary phenomena, the following parameters were recorded with non-invasive instruments in this order: skin capacitance (C1; arbitrary units; CM420 Corneometer), transepidermal water loss (TEWL; g/m2.h; Evaporimeter) and laser Doppler flowmetry (CBFV: cutaneous blood flow values; Periflux). All examinations were performed during winter on reclined relaxed subjects present for at least 10 min in a test room with controlled temperature and relative humidity (t degrees: 19.5-20.7 degrees C and RH: 47.3-60.3%). The analysis of differential data (delta = value at tx-value before test; 2-way ANOVA) was made on single parameters as a function of site (volar forearm versus neck) and time (from 24 h after 48-h occlusion with 5% SLS up to 10 days later). The profile of erythema scores over time differed between neck and forearm, but the delta CBFV readings with the laser Doppler instrument did not detect significant site-time interactions. Roughness (blind evaluation with palpating finger) and capacitance readings (delta C1) showed significant differences between sites, but the profile over time was similar in both locations. delta TEWL did not differ according to anatomical location. The reason for different erythema scores on neck and forearm might be related to inherent regional variation of optical properties of the skin or to a substantial contribution of SLS-induced roughness to the readings of erythema.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
40.
In all, 22 reports of 20 randomized, controlled rehabilitation studies were evaluated. In 18 of these, the design of the trial was parallel, with a cross-over format being employed in the remaining 2 instances. Seven studies related to intensive rehabilitation during the early post-acute period. In six others, specific techniques--sometimes associated with traditional physiotherapy procedures--were compared: biofeedback, perceptual retraining, and amphetamine treatment. Eight experiments evaluated speech therapy in aphasia. Frequently, methodological considerations limited the interpretation of the results. The review showed that: 1) as regards activities of daily life and motor function, differences as between rehabilitation in stroke units on the one hand and non-rehabilitation or rehabilitation in medical wards on the other, were detected in relatively few quality studies and remained particularly inconclusive insofar as life in the home environment was concerned; 2) rehabilitation for aphasia and perceptual dysfunction proved effective for at least several months after acute stroke; 3) in general, examination of the reports cited revealed no differences in the effects of biofeedback and perceptual retraining vs conventional physiotherapy; 4) rehabilitation, whether administered by specialists or amateur caregivers purpose-trained by specialists, proved equally effective for aphasia. These conclusions constitute a valuable basis for the development and evaluation of modern rehabilitation programs for stroke patients.  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