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   919篇
  免费   71篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   19篇
妇产科学   38篇
基础医学   130篇
口腔科学   21篇
临床医学   85篇
内科学   186篇
皮肤病学   18篇
神经病学   76篇
特种医学   25篇
外科学   125篇
综合类   3篇
一般理论   1篇
预防医学   94篇
眼科学   46篇
药学   58篇
中国医学   7篇
肿瘤学   56篇
  2023年   7篇
  2022年   22篇
  2021年   48篇
  2020年   20篇
  2019年   34篇
  2018年   34篇
  2017年   22篇
  2016年   26篇
  2015年   25篇
  2014年   43篇
  2013年   40篇
  2012年   78篇
  2011年   80篇
  2010年   32篇
  2009年   34篇
  2008年   41篇
  2007年   44篇
  2006年   36篇
  2005年   40篇
  2004年   24篇
  2003年   19篇
  2002年   20篇
  2001年   22篇
  2000年   17篇
  1999年   16篇
  1998年   3篇
  1996年   4篇
  1995年   3篇
  1994年   3篇
  1993年   5篇
  1992年   13篇
  1991年   14篇
  1990年   9篇
  1989年   14篇
  1988年   19篇
  1987年   4篇
  1986年   5篇
  1985年   4篇
  1984年   3篇
  1983年   5篇
  1981年   3篇
  1979年   2篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1974年   2篇
  1963年   9篇
  1962年   3篇
  1961年   5篇
  1960年   3篇
排序方式: 共有991条查询结果,搜索用时 15 毫秒
1.
Session XII Male contraception  相似文献   
2.
Conclusion Kashmir, with its culturally distinct population with uniform and stable dietary habits, provides an interesting field area for studying the relevance of diet in human esophageal carcinogenesis. In the absence of several features of life-style normally associated with increased incidence of the disease, the local food habits appear to be critical factors in the etiology of this cancer in Kashmir. Evidence from our preliminary studies shows a considerable dietary exposure to preformed N-nitroso compounds in the local population. In addition, the potential endogenous formation of N-nitroso compounds, caused by high precursor contents in certain foodstuffs, enhances the relevance of these compounds as possible risk factors for esophageal and other gastrointestinal cancers in this region. The quantitative assessment of total human exposure to N-nitroso compounds and their exact significance to the high cancer incidence in Kashmir requires carefully planned environmental monitoring and prospective epidemiological studies.The Journal of Cancer Research and Clinical Oncology publishes in loose succession Editorials and Guest editorials on current and/or controversial problems in experimental and clinical oncology. These contributions represent exclusively the personal opinion of the author  相似文献   
3.
With regard to cadmium toxicity, Drosophila strains v;bw and Austin represent extremes in resistance and sensitivity, respectively. Both strains produced metallothionein (MT) in response to Cd ions in their diet. Austin produced more metallothionein than v;bw at Cd ion levels below 0.2 mM, when both strains were allowed lifetime development on Cd2+-containing media. When the rate of MT appearance was measured for 4 days in young adults the results showed no clear trend with time within a strain or between strains. The plot of LC50 vs. MT levels for identical developmental conditions revealed that for v;bw small increases in MT corresponded to large increases in resistance whereas for the sensitive Austin even large increases in MT had comparatively little effect on increasing LC50. Results given here suggest that differences in total MT content do not explain the genetically demonstrable difference in Cd2+-resistance between v;bw and Austin. However, since two MT genes are identified in Drosophila, differences in resistance could be reflective of greater relative amounts of one "more important" MT in the resistant fly.  相似文献   
4.
5.
6.
Neurosurgical Review - Treatment of osteoporosis with medications like teriparatide, a parathyroid hormone, is known to improve bone density and reduce the risk of osteoporotic vertebral fractures....  相似文献   
7.
8.
ObjectiveTo assess health equity-oriented COVID-19 reporting across Canadian provinces and territories, using a scorecard approach.MethodsA scan was performed of provincial and territorial reporting of five data elements (cumulative totals of tests, cases, hospitalizations, deaths, and population size) across three units of aggregation (province or territory level, health regions, and local areas) (15 “overall” indicators), and for four vulnerable settings (long-term care and detention facilities, schools, and homeless shelters) and eight social markers (age, sex, immigration status, race/ethnicity, healthcare worker status, occupational sector, income, and education) (180 “equity-related” indicators) as of December 31, 2020. Per indicator, one point was awarded if case-delimited data were released, 0.7 points if only summary statistics were reported, and 0 if neither was provided. Results were presented using a scorecard approach.ResultsOverall, information was more complete for cases and deaths than for tests, hospitalizations, and population size denominators needed for rate estimation. Information provided on jurisdictions and their regions, overall, tended to be more available (average score of 58%, “D”) than that for equity-related indicators (average score of 17%, “F”). Only British Columbia, Alberta, and Ontario provided case-delimited data, with Ontario and Alberta providing case information for local areas. No jurisdiction reported on outcomes according to patients’ immigration status, race/ethnicity, income, or education. Though several provinces reported on cases in long-term care facilities, only Ontario and Quebec provided detailed information for detention facilities and schools, and only Ontario reported on cases within homeless shelters and across occupational sectors.ConclusionOne year into the pandemic, socially stratified reporting for COVID-19 outcomes remains sparse in Canada. However, several “best practices” in health equity-oriented reporting were observed and set a relevant precedent for all jurisdictions to follow for this pandemic and future ones.Supplementary InformationThe online version contains supplementary material available at 10.17269/s41997-021-00496-6.  相似文献   
9.
A total of 106 isolates of Mycobacterium tuberculosis were tested for drug susceptibility by the conventional 7H11 plate method and by a new rapid radiometric method using special 7H12 liquid medium with 14C-labeled substrate. Results obtained by the two methods were compared for rapidity, sensitivity, and specificity of the new test method. There was 98% overall agreement between the results obtained by the two methods. Of a total of 424 drug tests, only 8 drug results did not agree, mostly in the case of streptomycin. This new procedure was found to be rapid, with 87% of the tests results reportable within 4 days and 98% reportable within 5 days as compared to the usual 3 weeks required with the conventional indirect susceptibility test method. The results of this preliminary study indicate that the rapid radiometric method seems to have the potential for routine laboratory use and merits further investigations.  相似文献   
10.
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