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   45390篇
  免费   3903篇
  国内免费   169篇
耳鼻咽喉   533篇
儿科学   1319篇
妇产科学   997篇
基础医学   5669篇
口腔科学   722篇
临床医学   5857篇
内科学   8585篇
皮肤病学   611篇
神经病学   4833篇
特种医学   1245篇
外国民族医学   1篇
外科学   5367篇
综合类   642篇
一般理论   95篇
预防医学   5426篇
眼科学   1042篇
药学   3061篇
中国医学   64篇
肿瘤学   3393篇
  2024年   54篇
  2023年   493篇
  2022年   446篇
  2021年   1416篇
  2020年   996篇
  2019年   1292篇
  2018年   1540篇
  2017年   1171篇
  2016年   1244篇
  2015年   1289篇
  2014年   1817篇
  2013年   2545篇
  2012年   3461篇
  2011年   3435篇
  2010年   1962篇
  2009年   1711篇
  2008年   2857篇
  2007年   2858篇
  2006年   2853篇
  2005年   2750篇
  2004年   2493篇
  2003年   2187篇
  2002年   2081篇
  2001年   399篇
  2000年   350篇
  1999年   422篇
  1998年   494篇
  1997年   415篇
  1996年   331篇
  1995年   341篇
  1994年   214篇
  1993年   251篇
  1992年   211篇
  1991年   187篇
  1990年   185篇
  1989年   171篇
  1988年   140篇
  1987年   151篇
  1986年   152篇
  1985年   187篇
  1984年   179篇
  1983年   161篇
  1982年   204篇
  1981年   226篇
  1980年   179篇
  1979年   110篇
  1978年   121篇
  1977年   129篇
  1976年   109篇
  1975年   70篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
The Low Vision Clinic at the Palmerston North Hospital has now been oerating for 70 years. Over the course of these ten years a number of factors have emerged which can be as readily applied to general ophthalmological practice as to low vision practice. The philosophy of low vision care is one of which all ophthalmologists should be aware and includes factors to be taken into account when dealing with children, people in the workplace, and everyday factors involved in daily living activities, all of which are equally relevant in routine ophthalmological practice. This paper endeavours to share some thoughts on these factors and also discusses means by which the visually handicapped can be helped in areas where specialist low vision services are not readily available.  相似文献   
72.
Breast cancer is the most common cancer diagnosis for North American and Western European women. Increased knowledge in availability of genetic testing has helped to identify those women at high risk of eventually developing breast cancer. This has resulted in more women considering bilateral prophylactic mastectomy as a viable preventative option. Although the efficacy of the procedure has been established, much less is known about the psychological impact of undergoing this procedure. In order to assess these factors, we reviewed what is currently known about the psychological impact of undergoing bilateral prophylactic mastectomy. Searches were conducted and inclusion criteria revealed articles that focused on the psychological components involved with undergoing a bilateral prophylactic mastectomy. The findings are summarized and fell broadly into one or more of the following three areas: (1) satisfaction or regret following the surgery, (2) psychosocial functioning after the surgery, and (3) predictors of quality of life. Plastic surgery nurses have a unique opportunity to impact important psychological considerations, such as expectations of the early postoperative period, body image concerns, and psychological distress.  相似文献   
73.
OBJECTIVE: The purpose of this study was to determine whether social skills training can improve the social interaction skills of adolescents with craniofacial conditions (CFCs) in a natural environment (school lunchroom). DESIGN: This study used a pre-post between-group comparison design. Differences between treatment and control subjects were analyzed via a repeated measures analysis of variance. SETTING: The observations were conducted in the respective school lunch-rooms of the adolescents. Social skills groups were conducted in an outpatient clinic setting. MAIN OUTCOME MEASURES: Structured data based on 45 minutes of observation was coded for type, frequency, and duration of social contact. Specific measures included subject initiations and responses, peer initiations and responses, conversation events, total positive communication, and frequency of nondirected comments. RESULTS: Both target and peer-controlled total communication improved across time with adolescents receiving social skills intervention showing significantly more improvement than those adolescents not receiving direct social skills interventions. Adolescents receiving treatment participated in significantly more target initiated conversations lasting at least three interchanges and showed a trend toward a greater frequency of target initiations and positive responses to peer initiations. Peers were more likely to respond to treatment subject initiations after intervention. Fewer treatment subjects used nondirected communication, whereas control subjects continued to use nondirected communication at a slightly increased frequency. CONCLUSIONS: This study provides preliminary evidence that social skills training can increase the frequency of positive social interactions with peers for adolescents with CFCs.  相似文献   
74.
75.
The substitution of leucine for valine at amino acid position 34 of the factor XIII gene is commonly referred to as FXIII Val34Leu polymorphism. The homozygous leucine/leucine genotype has been reported to confer protection against venous thromboembolism, but previous studies have not evaluated a population limited to those with idiopathic venous thromboembolism. The primary objective of the study was to determine whether the FXIII Val34Leu polymorphism is independently associated with the occurrence of idiopathic venous thromboembolism. We prospectively enrolled consecutive patients with at least one objectively confirmed idiopathic venous thromboembolism. Friends of cases were recruited as controls and matched to cases by sex, ethnicity, and age. All participants were tested for the FXIII Val34Leu polymorphism in addition to several well-known thrombophilias. Data from 309 cases and 306 controls were analyzed. The FXIII leucine/leucine genotype was present in 4.9% of cases and 6.5% of controls. An adjusted odds ratio of 0.59 (95% confidence interval, 0.25-1.38) was found for the recessive model and 0.69 (95% confidence interval, 0.46-1.02) for the dominant model. Our results do not support an independent association of the FXIII Val34Leu polymorphism with idiopathic venous thromboembolism in our Caucasian Canadian study population.  相似文献   
76.
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified.  相似文献   
77.
Hurricanes Katrina and Rita forced many individuals along the coast of Texas and Louisiana to seek shelter inland. Among the evacuees were residents with special needs and residents of nursing homes and group homes caring for mentally retarded and physically disabled persons. Many nurses volunteered to provide health care for those in need. This article discusses challenges and opportunities that were encountered by nurses volunteering in special-needs shelters. Issues related to human and physical resources, patient care, and confidentiality are discussed including lessons learned. As nurses who cared for evacuees in the shelter, it is hoped some of the lessons learned can be utilized in future disasters.  相似文献   
78.
79.
We describe the presence of cylindrical spirals on muscle biopsy from a 31-year-old man who developed rhabodomyolysis following a long run. He had a prior history of exertional cramps and myoglobinuria. His maternal grandfather had similar symptoms. Transmission electron micrographs demonstrated continuity between the lamellae of the cylindrical spirals and native myofilaments. Whether these unusual structures confer a derangement in myofilament function is uncertain.  相似文献   
80.
In the present study, we address the role of the gene for catechol-O-methyltransferase (COMT), a key modulator of dopaminergic and noradrenergic neurotransmission, in the genetic predisposition to obsessive-compulsive disorder (OCD). We show that a common functional allele of this gene, which results in a 3- to 4-fold reduction in enzyme activity, is significantly associated in a recessive manner with susceptibility to OCD, particularly in males. This association is further supported by psychiatric evaluation of patients who carry microdeletions encompassing the comt gene. The mechanism underlying this sex-selective association remains to be defined and may include a sexual dimorphism in COMT activity, although close linkage with a nearby disease susceptibility locus cannot be excluded at this point.  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