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   418篇
  免费   32篇
  国内免费   2篇
儿科学   49篇
妇产科学   2篇
基础医学   43篇
口腔科学   27篇
临床医学   38篇
内科学   102篇
皮肤病学   5篇
神经病学   14篇
特种医学   36篇
外科学   34篇
综合类   8篇
预防医学   32篇
药学   16篇
中国医学   1篇
肿瘤学   45篇
  2023年   2篇
  2021年   5篇
  2020年   2篇
  2019年   2篇
  2018年   5篇
  2017年   12篇
  2016年   11篇
  2015年   7篇
  2014年   14篇
  2013年   27篇
  2012年   10篇
  2011年   23篇
  2010年   9篇
  2009年   12篇
  2008年   11篇
  2007年   21篇
  2006年   18篇
  2005年   15篇
  2004年   16篇
  2003年   13篇
  2002年   9篇
  2001年   22篇
  2000年   11篇
  1999年   11篇
  1998年   9篇
  1997年   9篇
  1996年   6篇
  1995年   5篇
  1994年   4篇
  1993年   4篇
  1992年   15篇
  1991年   8篇
  1990年   5篇
  1989年   10篇
  1988年   11篇
  1987年   10篇
  1986年   12篇
  1985年   6篇
  1984年   4篇
  1983年   6篇
  1982年   6篇
  1981年   4篇
  1980年   2篇
  1979年   6篇
  1978年   3篇
  1977年   2篇
  1976年   4篇
  1973年   3篇
  1971年   4篇
  1969年   2篇
排序方式: 共有452条查询结果,搜索用时 0 毫秒
11.
12.
BRCA1 and BRCA2 are the major genes predisposing to breast-ovarian cancer (i.e., breast or ovarian cancer or both). Since 1994, hundreds of distinct germline alterations have been reported in these two genes. Besides pathogenic mutations resulting in loss of function of the protein, an increased number of variants of unknown clinical significance have been described. In a cohort of 350 Swiss breast-ovarian cancer families, the systematic search for BRCA1/BRCA2 germline mutations was carried out using denaturating high-performance liquid chromatography as the first screening procedure. The screening strategy resulted in the identification of 23 alterations not previously reported: 9 in BRCA1 and 14 in BRCA2. By using the available tools to assign a functional role to newly identified sequence variations, 5 (22%) of these were classified as new disease-causing mutations, 5 (22%) were classified as benign polymorphisms, and the remaining 13 (56%) alterations were considered as unclassified variants. These data illustrate the major challenge for clinical oncologists currently facing the interpretation of alterations identified in BRCA1 or BRCA2. The key points are to classify these genetic variations as pathogenic mutations, benign polymorphisms, or variants of unknown clinical significance and to adequately use this information for the management of high-risk individuals and their families.  相似文献   
13.
Prognostic factors for the success rate of embryo freezing   总被引:5,自引:6,他引:5  
To find some prognostic factors for the outcome of frozen-thawed cycles, we have retrospectively analysed all frozen pre-embryos that were thawed during 1993 and 1994 at two in-vitro fertilization (IVF) units in Sweden. Supernumerary pre-embryos were frozen from 551 oocyte retrievals and these resulted in 660 frozen-thawed cycles which lead to 623 thawed embryo transfers. The outcome of these transfers was 137 clinical pregnancies with a pregnancy rate of 22% per frozen-thawed embryo transfers. Women <40 years of age had a higher birth rate than those > or =40 years, 19 and 5% respectively (P < 0.01). Transfers with two and three pre-embryos resulted in pregnancy rates of 23 and 27%, respectively, compared with 14% for transfer of one embryo. A pregnancy resulting from the initial embryo transfers had a predictive value for results of the subsequent frozen-thawed cycle. Embryo grade and cleavage stage at the time of freezing was important for the survival of the frozen-thawed pre-embryos. The pregnancy rate was not influenced by the cleavage stage, but a tendency toward a lower pregnancy rate was seen for the embryos with lower grading. To conclude, cryopreservation seems to be beneficial in women <40 years of age, who have supernumerary pre-embryos of good quality for freezing and of which at least two can be transferred.   相似文献   
14.
15.

Background

The increased reports of ESBL dissemination from various centres in south western, Nigeria and the recent emergence of carbapenem resistant bacteria prompted the conception of this study.

Objectives

To demonstrate the relationship between high molecular weight plasmids and the expression of antibiotic multi-resistance including ESBL and carbapenemase.

Methods

We investigated 97 isolates of selected organisms consisting of 67 E. coli and 30 Klebseilla spp for the presence of plasmids expressing ESBL including carbapenem-hydrolysing enzymes. Beta-lactamase was determined using acidometric method, while ESBL and carbapenemase activity was determined using the double-disk diffusion test as well as the Modified Hodge test (MHT). Plasmid profiles of ESBL and carbapenemase positive isolates were determined according to standard protocols.

Results

An ESBL prevalence rate of 21.6% and carbapenem- resistance rate of 9.3% was recorded. Antibiotic susceptibility profile of ESBL isolates showed 100.0% resistance against Amoxicillin, Cotrimoxazole and Erythromycin. Moderate susceptibility was recorded against the Quinolone class of antibiotics; Meropenem remained the most active antibiotic against ESBL isolates with 62.5% against E. coli and 60% against K. pneumoniae. The plasmid profiles of our study isolates ranged from 11.8kbp to 35.5kbp.

Conclusion

Due to the relationship between high molecular weight plasmids and multi-drug resistance, we hereby recommend regular molecular surveillance of this form in our study setting.  相似文献   
16.
17.
Two cases of upper sternal cleft are reported, the first operated on twenty nine months, the second on six weeks. The authors present a revision of the surgical technics proposed for correction of this rare malformation. The result is better and surgery easier when performed shortly after birth. There two cases had a facial angiomatosis associated.  相似文献   
18.
Daley  K.  B.  Wodrich  D.  L.  高蕊 《世界核心医学期刊文摘》2006,2(8):39-39
目的:观察评估通过使用胰岛素泵以稳定血糖,是否可以改善1型糖尿病患儿的课堂注意力。试验设计:对4例患有1型糖尿病且血糖水平不稳定的患儿在课堂中的表现进行为期10d的观察。在放置胰岛素泵,控制血糖后再观察10d。利用改良多基线设计血糖控制水平是否与患儿专注于功课和走神行  相似文献   
19.
OBJECTIVE--To determine the prevalence of behaviour disorders in low birthweight infants. DESIGN--Children of birth weight < or = 2000 g born to mothers resident in Merseyside in 1980-1 assessed using the Rutter parent and teacher behaviour questionnaires and the Conner modification of the Rutter teacher questionnaire. Children attending normal schools were assessed with controls matched for age, sex, and class in school. Children attending special schools were assessed unmatched. SUBJECTS--233 matched case-control pairs attending normal primary schools and 46 unmatched children attending special schools. SETTING--Primary and special schools. MAIN OUTCOME MEASURES--Emotional, conduct, and undifferentiated behaviour disorders and hyperactivity. RESULTS--On the parental questionnaire screen, 36% of the cases and 22% of the controls had a behaviour disorder and on the teacher questionnaire the proportions were 27% and 12% respectively. Hyperactivity was significantly more common among male cases than their controls (21% v 5.0%) but differed little among female cases and controls (9% v 7%). CONCLUSIONS--Improving neonatal survival of low birthweight infants is accompanied by a higher prevalence of behaviour disorders. The long term implications for psychiatric morbidity and other adult disease must be monitored.  相似文献   
20.
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