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   377篇
  免费   20篇
  国内免费   16篇
耳鼻咽喉   1篇
儿科学   22篇
妇产科学   7篇
基础医学   49篇
口腔科学   20篇
临床医学   33篇
内科学   67篇
皮肤病学   14篇
神经病学   9篇
特种医学   74篇
外科学   29篇
综合类   14篇
预防医学   11篇
眼科学   15篇
药学   19篇
中国医学   1篇
肿瘤学   28篇
  2022年   4篇
  2021年   4篇
  2019年   3篇
  2018年   8篇
  2017年   3篇
  2016年   8篇
  2015年   7篇
  2014年   17篇
  2013年   20篇
  2012年   6篇
  2011年   11篇
  2010年   34篇
  2009年   26篇
  2008年   11篇
  2007年   22篇
  2006年   11篇
  2005年   8篇
  2004年   3篇
  2003年   4篇
  2002年   5篇
  2001年   4篇
  2000年   4篇
  1999年   8篇
  1998年   33篇
  1997年   23篇
  1996年   16篇
  1995年   11篇
  1994年   12篇
  1993年   9篇
  1991年   4篇
  1990年   3篇
  1989年   10篇
  1988年   6篇
  1987年   5篇
  1985年   5篇
  1984年   2篇
  1983年   2篇
  1982年   6篇
  1981年   2篇
  1980年   9篇
  1978年   5篇
  1977年   3篇
  1974年   1篇
  1972年   1篇
  1959年   1篇
  1958年   2篇
  1957年   1篇
  1955年   1篇
  1954年   2篇
  1949年   2篇
排序方式: 共有413条查询结果,搜索用时 234 毫秒
91.
We compared the efficiency of removing cosmetic eyeliner deposits from soft contact lenses with a variety of surfactant cleaners. Four types of daily cleaners were used to clean two groups of soft contact lenses (Group 1 and Group 2 : FDA classification) contaminated with an eyeliner. The lenses were cleaned in a Clensatron 700CL Automatic Contact Lens Cleaning unit. The amount of lens contamination before and after cleaning was quantified by digitising a photograph of the lens surface. We found that: 1. the eyeliner was less likely to adhere to Group 2 lenses, 2. the efficiency of removing eyeliner was independent of the cleaning solutions we used; when contaminated, Group 2 lenses were generally easier to clean, 3. the Clensatron unit was not as efficient as digital rubbing in removing the eyeliner.  相似文献   
92.
Normal human spermatozoa carry either the X or the Y chromosome. The differences between X and Y spermatozoa (X and Y haploid cells) may exist in two areas: the different chromosomes (i.e. different kinds and numbers of genes) and the different sperm structures and functions (i.e. different genetic expression). The aim of this study was to determine whether there are any size between X and Y spermatozoa and whether sperm size and shape varies between men. Identification of the Y (and X inferred) status of individual spermatozoa was carried out by polymerase chain reaction (PCR), amplifying the putative testis- determining gene (SRY) together with a control gene (ZP3). PCR amplification of 871 out of 895 (97.3%) single motile spermatozoa showed that 444 (51.0%) were Y and 427 (49.0%) were X-bearing spermatozoa. Of 233 normally-shaped but immobilized spermatozoa, 217 (93.1%) were photographed and measured. Statistically, the length, perimeter and area of the sperm heads, and the length of the sperm necks and tails of X-bearing spermatozoa were significantly larger and longer than those of Y-bearing spermatozoa. Some peculiarities (or variations) in the X and Y sperm shape and size in individual donors were found. The pre-screening by micro-measurement of these specific haploid characteristics of individual spermatozoa in different donors, which may be closely related to their different genetic conditions (or diseases), may be important in human medicine and animal husbandry, especially in sperm prefertilization diagnosis.   相似文献   
93.
94.
95.
96.
Three previously healthy infants presented with diarrhoea and pyrexia and deteriorated rapidly. Two patients had necrotizing bowel disease requiring aggressive surgical intervention. All survived. P. aeruginosa gastrointestinal infection in previously healthy children is an extremely rare condition with a high mortality. Ecthyma gangrenosum was present in over 60% of reported cases although often not recognized initially. A high index of clinical suspicion, including prompt recognition of ecthyma gangrenosum, is mandatory for an early diagnosis of P. aeruginosa gastrointestinal infection. Early diagnosis and treatment may improve the prognosis.  相似文献   
97.
The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. The previous literature is also reviewed.  相似文献   
98.
99.

Background  

About 1.4 million Salmonella infections, a common food-borne illness, occur in the U.S. annually; the elderly (aged 65 or above) are most susceptible. In 1997, the USDA introduced the Pathogen Reduction and Hazard Analysis and Critical Control Points Systems (PR/HACCP) which demands regular Salmonella testing in various establishments processing meat products, such as broiler chickens. Impact evaluations of PR/HACCP on hospitalizations related to Salmonella are lacking.  相似文献   
100.
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