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   2442篇
  免费   136篇
  国内免费   61篇
耳鼻咽喉   8篇
儿科学   98篇
妇产科学   23篇
基础医学   362篇
口腔科学   32篇
临床医学   294篇
内科学   599篇
皮肤病学   59篇
神经病学   131篇
特种医学   337篇
外国民族医学   8篇
外科学   199篇
综合类   25篇
预防医学   108篇
眼科学   38篇
药学   152篇
中国医学   3篇
肿瘤学   163篇
  2021年   35篇
  2020年   21篇
  2019年   37篇
  2018年   50篇
  2017年   15篇
  2016年   23篇
  2015年   36篇
  2014年   37篇
  2013年   87篇
  2012年   90篇
  2011年   85篇
  2010年   62篇
  2009年   89篇
  2008年   69篇
  2007年   119篇
  2006年   78篇
  2005年   78篇
  2004年   70篇
  2003年   58篇
  2002年   58篇
  2001年   65篇
  2000年   56篇
  1999年   71篇
  1998年   82篇
  1997年   97篇
  1996年   114篇
  1995年   71篇
  1994年   63篇
  1993年   60篇
  1992年   41篇
  1991年   42篇
  1990年   58篇
  1989年   58篇
  1988年   60篇
  1987年   53篇
  1986年   67篇
  1985年   64篇
  1984年   23篇
  1983年   32篇
  1982年   26篇
  1981年   21篇
  1980年   14篇
  1979年   22篇
  1978年   25篇
  1977年   17篇
  1976年   19篇
  1975年   21篇
  1974年   12篇
  1973年   11篇
  1970年   11篇
排序方式: 共有2639条查询结果,搜索用时 0 毫秒
101.

Background

Chronic kidney disease (CKD) is highly prevalent in patients with diabetes or hypertension in primary care. A shared care model could improve quality of care in these patients

Aim

To assess the effect of a shared care model in managing patients with CKD who also have diabetes or hypertension.

Design and setting

A cluster randomised controlled trial in nine general practices in The Netherlands.

Method

Five practices were allocated to the shared care model and four practices to usual care for 1 year. Primary outcome was the achievement of blood pressure targets (130/80 mmHg) and lowering of blood pressure in patients with diabetes mellitus or hypertension and an estimated glomerular filtration rate (eGFR)<60ml/min/1.73m2.

Results

Data of 90 intervention and 74 control patients could be analysed. Blood pressure in the intervention group decreased with 8.1 (95% CI = 4.8 to 11.3)/1.1 (95% CI = −1.0 to 3.2) compared to −0.2 (95% CI = −3.8 to 3.3)/−0.5 (95% CI = −2.9 to 1.8) in the control group. Use of lipid-lowering drugs, angiotensin-system inhibitors and vitamin D was higher in the intervention group than in the control group (73% versus 51%, 81% versus 64%, and 15% versus 1%, respectively, [P = 0.004, P = 0.01, and P = 0.002]).

Conclusion

A shared care model between GP, nurse practitioner and nephrologist is beneficial in reducing systolic blood pressure in patients with CKD in primary care.  相似文献   
102.

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   
103.
We report two clinical pregnancies occurring after intracytoplasmic sperm injection (ICSI) using cryopreserved spermatozoa obtained from testicular biopsy, made in two different infertility situations in our clinic. The first patient showed a secretory azoospermia associated with elevated serum follicular stimulating hormone (FSH) level and spermiogenesis maturation arrest. The second patient was affected by azoospermia resulting from bilateral epididymal obstruction. Spermatozoa present in the wet preparation of testicular biopsy made on the day of scrotal exploration were cryopreserved within the testicular tissue for both men. Intracytoplasmic injections were performed at a later date, using spermatozoa prepared from frozen-thawed tissues. In each case, three embryos were obtained and transferred in utero. The transfers resulted in a twin pregnancy for the first case, and in a singleton pregnancy for the second. Living foetuses were seen in the ultrasound scan at the 7th week and both pregnancies are proceeding to date beyond 30 weeks without complications.   相似文献   
104.
Donor insemination (DI) using cryopreserved semen commenced at The Royal Women's Hospital in 1976. Over the next 15 years we performed 5953 treatment cycles to achieve 816 pregnancies (13.7% per cycle) and 706 live births. In-vitro fertilization (IVF) using donor spermatozoa commenced in 1986. Over the next 5 years we performed 303 treatment cycles for 185 couples. Including subsequent transfer of cryopreserved embryos, a total of 33% of couples achieved a successful pregnancy by IVF. Statistical analysis indicated that, for DI pregnancies, the most important semen variable was the percentage post-thaw motility, whilst for normal fertilization in IVF it was the pre-freeze motility. These results may be explained by the compensatory effects of post-thaw processing of spermatozoa for IVF, but not for DI in our clinic.   相似文献   
105.
106.
康继超  魏树礼 《药学学报》1997,32(7):536-541
为制备能用于清除骨髓中癌细胞的磁性微球,首先合成了单分散、大粒径的多孔聚苯乙烯交联微球,借助微球多孔结构对其进行磁化。探讨了影响磁化效果的主要因素。为使其与单抗连接紧密,在微球表面聚合了一层聚丙烯醛膜,使其表面带上易与单抗反应的醛基。同时测定了所制微球的磁响应性。X-射线衍射证明磁性物质为γ-Fe2O3。  相似文献   
107.

Background  

Cancer metastasis contributes significantly to cancer mortality and is facilitated by lymphangiogenesis and angiogenesis. A new splicing variant, endogenous soluble vascular endothelial growth factor receptor-2 (esVEGFR-2) that we recently identified is an endogenous selective inhibitor of lymphangiogenesis. To evaluate the antimetastatic potential of esVEGFR-2, gene therapy with vector expressing esVEGFR-2 (pesVEGFR-2) or endostatin (pEndo) as a positive control was conducted on murine metastatic mammary cancer.  相似文献   
108.
109.
110.
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