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   617篇
  免费   61篇
  国内免费   5篇
耳鼻咽喉   5篇
儿科学   50篇
妇产科学   15篇
基础医学   60篇
口腔科学   16篇
临床医学   80篇
内科学   107篇
皮肤病学   7篇
神经病学   14篇
特种医学   144篇
外科学   37篇
综合类   35篇
预防医学   60篇
眼科学   3篇
药学   34篇
肿瘤学   16篇
  2023年   1篇
  2022年   1篇
  2021年   4篇
  2020年   3篇
  2019年   3篇
  2018年   13篇
  2017年   7篇
  2016年   7篇
  2015年   14篇
  2014年   20篇
  2013年   26篇
  2012年   16篇
  2011年   12篇
  2010年   18篇
  2009年   10篇
  2008年   13篇
  2007年   16篇
  2006年   18篇
  2005年   17篇
  2004年   16篇
  2003年   22篇
  2002年   18篇
  2001年   16篇
  2000年   13篇
  1999年   22篇
  1998年   36篇
  1997年   34篇
  1996年   37篇
  1995年   36篇
  1994年   33篇
  1993年   21篇
  1992年   4篇
  1991年   8篇
  1990年   6篇
  1989年   14篇
  1988年   20篇
  1987年   17篇
  1986年   18篇
  1985年   18篇
  1984年   9篇
  1983年   11篇
  1982年   5篇
  1981年   10篇
  1980年   5篇
  1979年   2篇
  1978年   2篇
  1977年   3篇
  1976年   5篇
  1975年   2篇
  1974年   1篇
排序方式: 共有683条查询结果,搜索用时 0 毫秒
1.
2.
目的:对临床确诊糖尿病患同时测定血清葡萄糖(Glu)及糖化血清蛋白(GSP)的含量,观察二的关系,以及糖化血清蛋白水平对于评价近期(2—3周)糖尿病患血糖在体内变化的临床意义进行了观察。方法:血清葡萄糖、糖化血清蛋白测定均采用酶法测定。结果:178例糖尿病患Glu、GSP均正常3l例占17.4%;Glu、GSP均增高107例占60.1%;Glu正常、GSP增高15例占8.43%;Glu增高、GSP正常25例占14%。结论:糖化血清蛋白的含量不受即时血糖的影响,二的变化不成比例性,对评价糖尿病患2~3周病情的控制是一项灵敏可靠的指标,尤其对于住院病人的治疗与监控有一定的意义。  相似文献   
3.
4.
5.
In a prospective cohort study of the long-term sequelae of induced abortion, a comparison is made between a group of 6418 women who had an induced abortion (cases) and a control group of 8059 women recruited with an unplanned pregnancy which was not terminated with an induced abortion (controls). The present paper reports on 729 cases and 1754 controls who had a post-recruitment pregnancy. In general, prior induced abortion had no material effect on the rate of pregnancy-related morbidity, nor on the rate of congenital abnormalities and neonatal death in the offspring. There was, however, a significant difference in two specific conditions. In the post-index pregnancy in the cases there was an increased relative risk (RR 2.26) of the occurrence of urinary tract infection and a decreased risk (RR 0.25) of pregnancy-related anaemia.  相似文献   
6.
Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.   相似文献   
7.
AIM: To determine the relative importance of factors that influence decision making in the management of minor illness, and how people trade between these factors. DESIGN OF STUDY: Discrete choice experiment.Setting:Scottish electoral roll. METHOD: Six hundred and fifty-two responders of a previous national survey were invited to complete a discrete choice experiment questionnaire. This was used to measure relative preferences for managing symptoms of minor illness often associated with analgesic use. Three attributes were identified as important to participants: type of management, availability, and cost of managing symptoms. Trade-offs between these attributes were examined. RESULTS: A 57% response rate was achieved (51% valid response rate). People preferred to manage symptoms by self-care and were willing to pay almost pounds 23 to do so. Community pharmacy was the preferred source of advice. Responders preferred less waiting time and paying less money when managing symptoms, and were willing to trade between factors. A less preferred type of management became more attractive when waiting times and cost were reduced. CONCLUSION: Findings suggest that self-care is the preferred method of managing symptoms of minor illness. When developing services to support self-care, policy makers should invest in services that reduce waiting times and incur least cost to users.  相似文献   
8.
9.
BACKGROUND: Take Care is a commercially sponsored educational package for the detection and management of depression by all members of the primary health-care team. AIM: This study was designed to evaluate whether the educational package affects the recognition of psychological illness by general practitioners. METHOD: General practitioners working in 13 practices in North West England or Trent Regional Health Authorities took part the evaluation. Patients who scored more than eight on the depression or anxiety component of the Hospital Anxiety and Depression (HAD) scales, and who were thought by their general practitioner to have a totally physical problem or no illness, were deemed to have a psychological illness that had been 'missed' by the doctor. Changes in the proportion of missed cases before and after exposure to Take Care were estimated. RESULTS: When all practices were considered together, the general practitioners missed a depressive illness in 24.1% of patients before Take Care, and 17.1% afterwards; absolute decrease 7.0% [95% confidence interval (CI) -2.0 to -12.0%]. An improvement was seen in most practices (Wilcoxon matched-pair test P < 0.05). The programme was also associated with a small reduction in the overall proportion of episodes of anxiety missed by the doctor (absolute decrease 4.5%; 95% CI -1.0 to -8.0%) a reduction was found in most practices (Wilcoxon matched-pair test P < 0.05). There was no material difference in the diagnostic false-positive rate of the doctors before and after the introduction of the programme. CONCLUSION: Exposure to an educational package for depression was associated with improved recognition of psychological illness by general practitioners.  相似文献   
10.
Tuberous sclerosis is an autosomal dominant trait in which the dysregulation of cellular proliferation and differentiation results in the development of hamartomatous growths in many organs. The TSC2 gene is one of two genes determining tuberous sclerosis. Inactivating germline mutations of TSC2 in patients with tuberous sclerosis and somatic loss of heterozygosity at the TSC2 locus in the associated hamartomas indicate that TSC2 functions as a tumour suppressor gene and that loss of function is critical to expression of the tuberous sclerosis phenotype. The TSC2 product, tuberin, has a region of homology with the GTPase activating protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in vitro. Here we show that the region of homology between tuberin and human rap1GAP and the murine GAP mSpa1 is more extensive than previously reported and spans approximately 160 amino acid residues encoded within exons 34-38 of the TSC2 gene. Single strand conformation polymorphism analysis of these exons in 173 unrelated patients with tuberous sclerosis and direct sequencing of variant conformers together with study of additional family members enabled characterisation of disease associated mutations in 14 cases. Missense mutations, which occurred in exons 36, 37 and 38 were identified in eight cases, four of whom shared the same recurrent change P1675L. Each of the five different missense mutations identified was shown to occur de novo in at least one sporadic case of tuberous sclerosis. The high proportion of missense mutations detected in the region of the TSC2 gene encoding the GAP-related domain supports its key role in the regulation of cellular growth.   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