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   4832914篇
  免费   377575篇
  国内免费   42065篇
耳鼻咽喉   63594篇
儿科学   148146篇
妇产科学   122419篇
基础医学   719982篇
口腔科学   129266篇
临床医学   463028篇
内科学   853873篇
皮肤病学   113768篇
神经病学   389070篇
特种医学   185082篇
外国民族医学   835篇
外科学   705012篇
综合类   197706篇
现状与发展   107篇
一般理论   2637篇
预防医学   401342篇
眼科学   115917篇
药学   352412篇
  459篇
中国医学   36894篇
肿瘤学   251005篇
  2021年   73431篇
  2020年   49483篇
  2019年   69642篇
  2018年   85876篇
  2017年   68089篇
  2016年   73115篇
  2015年   91705篇
  2014年   129967篇
  2013年   194014篇
  2012年   155641篇
  2011年   164697篇
  2010年   147942篇
  2009年   144309篇
  2008年   139663篇
  2007年   146484篇
  2006年   153516篇
  2005年   147350篇
  2004年   141265篇
  2003年   129741篇
  2002年   117200篇
  2001年   177001篇
  2000年   172800篇
  1999年   158092篇
  1998年   76708篇
  1997年   72047篇
  1996年   69150篇
  1995年   64575篇
  1994年   58206篇
  1993年   53391篇
  1992年   112078篇
  1991年   107647篇
  1990年   102654篇
  1989年   99602篇
  1988年   91697篇
  1987年   89508篇
  1986年   84947篇
  1985年   82945篇
  1984年   68801篇
  1983年   61056篇
  1982年   48492篇
  1981年   45173篇
  1980年   42288篇
  1979年   58718篇
  1978年   47279篇
  1977年   41996篇
  1976年   39112篇
  1975年   38558篇
  1974年   42689篇
  1973年   41200篇
  1972年   38466篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Despite the widespread use of botulinum toxin to treat muscle dystonias, no method exists to quantify muscle paralysis in either human or nonhuman models. In this study we examined how the location, dose, and volume of botulinum injection affects paralysis in the rat tibialis anterior muscle. Paralysis was quantified by electrically stimulating the nerve to the tibialis anterior and then staining sections of the muscle for glycogen. The areas of glycogen-containing fibers represented regions of botulinum action. The results showed that the most important injection technique is to inject botulinum directly into the motor endplate region of a muscle. Injections only 0.5 cm from the motor endplate resulted in a 50% decrease in paralysis. Increases in dose increased paralysis, however, some of that increase was simply due to the increased volume of injection. Thus, delivering toxin in small volumes near the MEP band of a muscle should produce the most effectiveparalysis. © 1993 John Wiley & Sons, Inc.  相似文献   
992.
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   
993.
The synopsis of neurogenic lower urinary tract dysfunctions aims to be practical and tries to give some simple algorithms to the physician to help his understanding of the pathophysiology and to guide him towards an easy, functional, preventive and chronological exploration and treatment.  相似文献   
994.
995.
A study was carried out in order to document any abnormalities in the electro-encephalogram (EEG) that might appear in young adolescents who have deliberately inhaled the range of volatile substances loosely referred to as 'glue'. The EEGs of a group of 'street children' being assisted in a Johannesburg shelter were examined. The records were analysed for any clinical abnormalities and also subjected to spectral analysis in order to examine the overall characteristics of frequency, power and spatial distribution. The EEGs clearly revealed that, although at the time of the examination the subjects were ostensibly abstinent, both clinical and normative evidence of continuing brain disturbance was present. It was concluded that glue sniffing is likely to have long term electrocerebral sequelae.  相似文献   
996.
The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate.  相似文献   
997.
李惠兰  缪鸿石 《中国康复》1993,8(3):122-124
观察了10项因素对偏瘫病人下肢功能康复的影响,其结果表明:①下肢功能水平;②平衡功能障碍;③足下垂内翻;④髋关节屈曲外旋挛缩;⑤深感觉障碍;⑥疼痛等几项因素对偏瘫病人下肢功能康复有显著的影响。  相似文献   
998.
Despite a widely held belief that the use of emollients prior to broad-band UVB irradiation accelerates clearance of psoriasis, only one single-blind controlled study exists in support of this. No similar study has been carried out with photochemotherapy (PUVA) or narrow-band UVB (311–313 nm) phototherapy. As some emollients absorb UV radiation, and thereby inhibit psoriasis clearance, there is a need to identify emollients suitable for pre-irradiation use. Coconut oil may be useful in this respect. In two randomized groups of patients with chronic plaque psoriasis undergoing either routine PUVA(n=14) or narrow-band UVB phototherapy (n=15), a single-blind controlled (half-body) study was undertaken to assess the died of pre-irradiation application of coconut oil. Patients were given PUVA twice weekly, or TL-01 therapy thrice weekly. The initial UV dose was 70% of previously determined minimal phototoxic (MPD) or minimal erythema doses (MED), with 40% incremental steps at each visit (reduced if adverse effects occurred). Psoriasis severity was scored on each side after every three treatments. No significant acceleration of psoriasis clearance was seen in either group. We do not, therefore, recommend the routine use of emollients prior to PUVA or TL-01 therapy when using near erythemogenic irradiation regimens.  相似文献   
999.
ABSTRACT. This paper describes the method and results of a survey of aggressive behaviour amongst people with learning difficulties. The study was confined to a single health district in the South Western Region of the UK with a general population of about 370000. At the time of the survey, the Handicap Register for the district recorded 1362 people as having a learning difFiculty. The overall prevalence of aggressive behaviour amongst people with learning difficulties for whom base population data was available was 17.6%. The lowest rate was identified amongst day facilities (9.7 %) and the highest in hospitals within the district (38.2%). The prevalence rate amongst those attending schools for children with severe learning difSculties was 12.6%. Proportionately more males than females were reported to present problems of aggressive behaviour. The gender difference appeared to be largely accounted for by the disproportionate number of men identified within day facilities. There was no significant evidence of an association between the person's gender and the presence aggressive behaviour within schools or hospitals. The results indicated that, although physical and verbal aggression were the most frequently reponed behaviours, many of the sample were also said to engage in other forms of challenging behaviour, particularly self-injurious, ritualistic, stereotypical and withdrawn behaviour. The risk of a serious or very serious injury to another person was very low; 0.7% or six people with learning difiSculties firom the district were reponed to be currently presenting such a risk. Similarly, only 2% of the base population (n=18) were reponed to be extremely difficult to manage. The implications of the findings are discussed.  相似文献   
1000.
Nine hundred and three patients undergoing diagnostic peritoneal lavage (DPL) over a 6-year period were retrospectively reviewed to evaluate the utility of the white blood cell (WBC) count in the lavage fluid. Eleven patients (1.2%) had dialysate WBC counts greater than 500/mm3, with erythrocyte counts less than 10(5)/mm3. Nine of these patients who were lavaged within 4 hours of injury had no intra-abdominal pathology. Two patients, lavaged after 4 hours, demonstrated intra-abdominal injury. Two hundred twenty-three patients (24.7%) had grossly clear dialysate which was not sent for laboratory analysis. None of these patients required laparotomy. We conclude that the WBC count in DPL fluid is of no diagnostic value in victims of blunt abdominal trauma who are lavaged within 4 hours of injury. In addition, laboratory analysis of clear dialysate is not required in these 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