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   537篇
  免费   28篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   36篇
妇产科学   3篇
基础医学   42篇
口腔科学   18篇
临床医学   35篇
内科学   131篇
皮肤病学   8篇
神经病学   9篇
特种医学   79篇
外科学   65篇
综合类   64篇
预防医学   33篇
眼科学   8篇
药学   20篇
肿瘤学   20篇
  2024年   1篇
  2023年   2篇
  2022年   5篇
  2021年   6篇
  2020年   5篇
  2019年   2篇
  2018年   6篇
  2017年   4篇
  2016年   9篇
  2015年   16篇
  2014年   11篇
  2013年   16篇
  2012年   8篇
  2011年   10篇
  2010年   19篇
  2009年   32篇
  2008年   11篇
  2007年   20篇
  2006年   31篇
  2005年   9篇
  2004年   9篇
  2003年   3篇
  2002年   8篇
  2001年   11篇
  2000年   7篇
  1999年   14篇
  1998年   42篇
  1997年   31篇
  1996年   40篇
  1995年   18篇
  1994年   18篇
  1993年   25篇
  1992年   4篇
  1991年   9篇
  1990年   4篇
  1989年   11篇
  1988年   25篇
  1987年   11篇
  1986年   8篇
  1985年   18篇
  1984年   7篇
  1983年   4篇
  1982年   3篇
  1981年   3篇
  1980年   4篇
  1979年   1篇
  1977年   3篇
  1976年   5篇
  1975年   3篇
排序方式: 共有572条查询结果,搜索用时 15 毫秒
121.
过去10至15年间,关于对早产儿必须提供适宜的环境的论点,已被众多的研究者反复论证.通过减少有害的刺激如光、声、人员往来,并且给予适当的体位和护理,早产儿护理的效果显著好转.  相似文献   
122.
Background Renal transplant recipients (RTR) have a well recognized increased risk of cutaneous malignancy. A clinical observation that RTR with skin cancer often had multiple seborrhoeic warts prompted an investigation in RTR into the relationship between seborrhoeic warts and skin cancer and an exploration into potential risk factors for seborrhoeic warts in this population, including infection with human papillomavirus (HPV). Methods This was a case control study involving 308 RTR. Clinical examinations identified seborrhoeic warts. Histological records reviewed to look for evidence of prior cutaneous malignancy. Seroprevalence of antibodies to 34 different HPV types tested using multiplex serology. Odds ratios (OR) calculated using unconditional logistic regression analysis to look for associations between skin cancer, HPV infection and seborrhoeic warts, controlling for potential confounding factors of gender, age and time since transplantation. Results Seborrhoeic warts were associated with non‐melanoma skin cancer [OR = 3.7; 95% confidence intervals (CI) ranging from 1.6–8.9; P = 0.002] when confounding factors of gender, age and time since transplantation were controlled for. There was also an association between seborrhoeic warts and viral warts (OR = 3.0, CI: 1.6–5.4; P < 0.0001), but no association between seborrhoeic warts and infection with single or multiple HPV types. Conclusions Seborrhoeic warts are associated with cutaneous malignancy, but not with any of the HPV types tested. The reasons for this association are unclear. RTR with multiple seborrhoeic warts may require more regular cutaneous examination to monitor for early signs of skin cancer.  相似文献   
123.
124.
Modeling the growth of Yersinia enterocolitica in donated blood   总被引:4,自引:0,他引:4  
BACKGROUND: Sepsis and death subsequent to the transfusion of blood containing Yersinia enterocolitica is an increasing problem. The organisms probably originate from bacteremia in the donor and can subsequently multiply at low temperature. STUDY DESIGN AND METHODS: Reported here are experiments with a strain of Y. enterocolitica associated with a case of transfusion-associated bacteremia. RESULTS: It was found that the rapid early killing of Y. enterocolitica injected into donated blood does not require viable phagocytes and can be explained by complement-mediated killing. Complement resistance in Y. enterocolitica is known to be plasmid-coded. It is expressed at 37 degrees C, but not at 20 degrees C, and is favored by calcium-deficient culture media. Y. enterocolitica organisms induced to express complement resistance were still killed in donated blood, though the initial rate was slower. Such organisms multiplied in plasma at 37 degrees C, but were killed after 6 hours of incubation at 20 degrees C, presumably because complement resistance genes are switched off at this temperature. CONCLUSION: This experiment is thought to reflect the natural history of Y. enterocolitica contamination of blood, in which complement-resistant organisms in the donor blood encounter lower temperatures after donation. These observations suggest that the practice of plasma depletion may have contributed to the increased incidence of mortality due to Y. enterocolitica contamination of donated blood.  相似文献   
125.
126.
127.
Swanson  DK; Myerowitz  PD; Hegge  JO; Watson  KM 《Radiology》1986,161(2):323-328
With a new radiographic method to determine the pulsatile flow pattern in an imaged artery, flow velocity is determined by tracking the movement of contrast material along the artery over time. Flow velocity is multiplied by an automatically determined cross-sectional area of the artery to determine blood flow. Pulsatile blood-flow waveforms were determined by radiographic and electromagnetic techniques in each femoral artery of four dogs while flow conditions were varied. Peak and average blood flows measured by the two techniques were highly correlated (r = .97 and .95, respectively). The closest agreement between the flow waveforms measured by the electromagnetic and radiographic techniques was found under normal flow conditions. The radiographically derived flow waveforms tended to be noisy at low blood-flow rates, and instantaneous blood-flow rates exceeding 700 ml/min were underestimated.  相似文献   
128.
129.
130.
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