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   1970篇
  免费   136篇
  国内免费   18篇
耳鼻咽喉   40篇
儿科学   61篇
妇产科学   35篇
基础医学   158篇
口腔科学   67篇
临床医学   189篇
内科学   367篇
皮肤病学   54篇
神经病学   65篇
特种医学   129篇
外国民族医学   2篇
外科学   386篇
综合类   71篇
预防医学   123篇
眼科学   69篇
药学   160篇
中国医学   16篇
肿瘤学   132篇
  2023年   30篇
  2022年   52篇
  2021年   86篇
  2020年   47篇
  2019年   57篇
  2018年   103篇
  2017年   62篇
  2016年   70篇
  2015年   56篇
  2014年   78篇
  2013年   108篇
  2012年   140篇
  2011年   141篇
  2010年   79篇
  2009年   47篇
  2008年   74篇
  2007年   99篇
  2006年   102篇
  2005年   99篇
  2004年   85篇
  2003年   78篇
  2002年   79篇
  2001年   51篇
  2000年   46篇
  1999年   48篇
  1998年   14篇
  1997年   22篇
  1996年   20篇
  1995年   12篇
  1994年   11篇
  1993年   9篇
  1992年   11篇
  1991年   4篇
  1990年   11篇
  1989年   4篇
  1988年   4篇
  1987年   4篇
  1986年   5篇
  1985年   5篇
  1984年   9篇
  1983年   4篇
  1980年   8篇
  1978年   4篇
  1976年   3篇
  1974年   3篇
  1973年   2篇
  1972年   5篇
  1971年   2篇
  1969年   9篇
  1967年   4篇
排序方式: 共有2124条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
我院自1984~1989年采用硅橡胶涤纶丝网颅骨成型片修补颅骨缺损116例,随访6月~4年,疗效满意。对颅骨修补的适应症作了讨论。减少手术创伤、预防术后感染,是保证手术成功的关键。  相似文献   
5.
C1-Cx revisited: intramolecular synergism in a cellulase.   总被引:4,自引:0,他引:4       下载免费PDF全文
Endoglucanase A (CenA) from the bacterium Cellulomonas fimi is composed of a catalytic domain and a nonhydrolytic cellulose-binding domain that can function independently. The individual domains interact synergistically in the disruption and hydrolysis of cellulose fibers. This intramolecular synergism is distinct from the well-known intermolecular synergism between individual cellulases. The catalytic domain corresponds to the hydrolytic Cx system and the cellulose-binding domain corresponds to the nonhydrolytic C1 system postulated by Reese et al. [Reese, E. T., Sui, R. G. H. & Levinson, H. S. (1950) J. Bacteriol. 59, 485-497] to be required for the hydrolysis of cellulose.  相似文献   
6.
Chlamydial infections and male infertility   总被引:3,自引:0,他引:3  
Chlamydial infections may be difficult to diagnose due to the silent symptoms and difficulty in culturing. An infectious process may impair fertility by adversely affecting sperm functions, resulting in testicular damage or causing obstruction of the genital tract. In our study, we tried to find Chlamydial antigen by using EIA (Enzyme Immune Assay) and to compare the Ag(+) and Ag(−) groups according to semen parameters. Except for semen volume, we found significant differences in density, morphology, motility and viability (intervolume p>0.05, interdensity p<0.01, intermorphology p<0.001, intermotility p<0.001 and interviability p<0.001).  相似文献   
7.
Partial thickness burns (PTB) usually heal within 3 weeks. Prevention of infection and desiccation of the wounds are crucial for optimal healing. Early tangential excision of the burn eschar and allografting prevent deepening of the burns, and are therefore advocated for treatment with the best functional and aesthetic results. For superficial partial thickness burns (SPTB) conservative use of topical antimicrobial agents with frequent dressing changes are implemented. We compared the conservarive treatment for PTBs and SPTBs to grafting cryopreserved cadaveric allografts with no prior excision.

Twelve patients with flame PTB areas were allografted after mechanical debridement without excision of the burn wounds. The allografts were cadaveric skin cryopreserved by programmed freezing and stored at −180°C for 30–48 months. Matching burns for depth and area were treated with silver sulfadiazine (SSD) one to two times daily until healing or debridement and grafting were required.

It was found that 80 per cent of the cryopreserved allografts adhered well and 76 per cent of the treated areas healed within 21 days, whereas only 40 per cent of the SSD-treated burns healed within 21 days.

Partial thickness burns can be treated successfully with viable human allografts (cryopreserved cadaveric skin) with no prior surgical excision. The burn wounds heal well within 3 weeks. For deep partial thickness burns (DPTB) treatment with allografts has no advantage if they have not been previously excised.  相似文献   

8.
本实验采用随机引物法标记探针DNA.探针DNA加热变性成单链,以单链DNA为模板,六聚脱氧核苷酸为引物,在DNA多聚酶I大片段的作用下进行放射性标记.标记探针的比放射性达10~8cpm/μg DNA以上.放射性底物的掺入率为60%.用该方法标记的人高度重复顺序探针,可以检出微微克水平的阳性分子.与人HeLa S_3细胞DNA转化的小鼠LTK~+细胞DNA打点杂交呈阳性,与未经转化的小鼠LTK~-细胞DNA杂交为阴性,证明小鼠转化细胞中存在HeLa细胞DNA,DNA转化是成功的.  相似文献   
9.
A fibrinolytic enzyme obtained from B. subtilis was purified, using DEAE-cellulose column chromatography, and gel filtration on Sephadex G-100. The preparation was homogeneous as tested by gel filtration on Sephadex G-200, and disc electrophoresis. The molecular weight of this enzyme was 29.400 estimated by gel filtration on Sephadex G-100. The optimum pH for enzyme activity was 7.2. Copper ions significantly increased enzyme activity, while Zn++ and Mn++ caused marked inhibition.  相似文献   
10.
Autosomal recessive nonsyndromic deafness is one of the most frequent forms of inherited hearing impairment. Over 30 autosomal recessive nonsyndromic hearing loss loci have been mapped, and 15 genes have been isolated. Of the over 30 reported autosomal recessive nonsyndromic hearing loss (NSHL) loci, the typical phenotype is prelingual non-progressive severe to profound hearing loss with the exception of DFNB8, which displays postlingual onset and DFNB13, which is progressive. In this report we describe a large inbred kindred from a remote area of Pakistan, comprising six generations and segregating autosomal recessive nonsyndromic prelingual deafness. DNA samples from 24 individuals were used for genome wide screen and fine mapping. Linkage analysis indicates that in this family the NSHL locus, (DFNB35) maps to a 17.54 cM region on chromosome 14 flanked by markers D14S57 and D14S59. Examination of haplotypes reveals a region that is homozygous for 11.75 cM spanning between markers D14S588 and D14S59. A maximum two-point LOD score of 5.3 and multipoint LOD score of 7.6 was obtained at marker D14S53. The interval for DFNB35 does not overlap with the regions for DFNA9, DFNA23 or DFNB5.  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