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   2809篇
  免费   159篇
  国内免费   13篇
耳鼻咽喉   39篇
儿科学   71篇
妇产科学   96篇
基础医学   346篇
口腔科学   61篇
临床医学   261篇
内科学   554篇
皮肤病学   171篇
神经病学   257篇
特种医学   77篇
外科学   251篇
综合类   21篇
一般理论   1篇
预防医学   311篇
眼科学   65篇
药学   168篇
中国医学   16篇
肿瘤学   215篇
  2024年   3篇
  2023年   17篇
  2022年   39篇
  2021年   107篇
  2020年   52篇
  2019年   99篇
  2018年   91篇
  2017年   63篇
  2016年   73篇
  2015年   72篇
  2014年   110篇
  2013年   154篇
  2012年   228篇
  2011年   256篇
  2010年   120篇
  2009年   108篇
  2008年   212篇
  2007年   223篇
  2006年   181篇
  2005年   201篇
  2004年   160篇
  2003年   124篇
  2002年   119篇
  2001年   22篇
  2000年   8篇
  1999年   15篇
  1998年   17篇
  1997年   23篇
  1996年   17篇
  1995年   10篇
  1994年   11篇
  1993年   12篇
  1992年   4篇
  1991年   2篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   5篇
  1983年   1篇
  1982年   7篇
  1981年   1篇
  1980年   3篇
  1977年   1篇
  1975年   1篇
  1974年   2篇
  1968年   1篇
排序方式: 共有2981条查询结果,搜索用时 0 毫秒
21.
Purpose: To investigate possible associations between genetic markers and Primary Open-Angle Glaucoma (POAG). Methods: A number of genetic markers were typed in 84 unrelated patients with POAG and compared with a random sample of healthy individuals. The markers were Transferrin, Group Specific Component, G1m (1), G1m (2) and G3m (5) Allotypes, Adenylate Kinase, Adenosin Deaminase, Glyoxalase I and Acid Phosphatase and PCR-based markers HLA-DQA1 and D1S80. Results: No significant differences were found except the strong association between the group of POAG patients and Acid Phosphatase ACP*C allele (2 = 32.86; p < 0.0001). Conclusions: Since Acid Phosphatase gene is localized to chromosome 2p23, this result could be a first comprehensive step in the localization of POAG genes.  相似文献   
22.
We studied the effect of the opiate antagonist naloxone on the human gastric acid secretory response to three secretory stimulants: sham feeding, pentagastrin, and histamine. Intravenous naloxone (40 g/kg/hr) significantly inhibited the acid secretory response to sham feeding without affecting the serum gastrin response to sham feeding. Naloxone also significantly reduced pentagastrin- and histamine-stimulated acid secretion. These studies indicate that naloxone reduces acid secretion in response to all stimulants of acid secretion yet tested in humans.This study was supported by grants AM-16816 and AM-17328, from the National Institute of Arthritis, Metabolism and Digestive Diseases.Presented in part at the Plenary Session of the American Gastroenterological Association, Salt Lake City, Utah, May 19, 1980.  相似文献   
23.
PURPOSE: Denileukin diftitox is a fusion protein combining diphtheria toxin and interleukin-2 (IL-2) that targets tumor cells expressing the IL-2 receptor. Its efficacy has been shown in CD25+ cutaneous T-cell lymphoma, but not in B-cell non-Hodgkin's lymphoma (NHL). A phase II study was performed to evaluate the efficacy and tolerability of denileukin diftitox for relapsed or refractory B-cell NHL. PATIENTS AND METHODS: Patients with relapsed or refractory B-cell NHL were eligible. Tumor CD25 expression was determined by immunohistochemistry or flow cytometry. Denileukin diftitox was administered intravenously at a dose of 18 microg/kg once daily for 5 days every 3 weeks, up to eight cycles. RESULTS: Of the 45 patients assessable for response, 32 (71%) were refractory to the last chemotherapy treatment, and all were previously treated with rituximab. Three complete responses (6.7%) and eight partial responses (17.8%) were observed, for an overall response rate of 24.5%. Nine patients (20%) had stable disease. Objective response rates were similar in CD25+ (22%) and CD25- histologies (29%), as were stable disease rates (22% and 18%, respectively). For responding patients, the median time to treatment failure was 7 months, with a median follow-up in survivors of 18 months (range, 9 to 28 months), and the projected progression-free survival at 20 months was 24% (95% CI, 0% to 60%). Most toxicities were low-grade and transient. CONCLUSION: Denileukin diftitox seems to be effective in relapsed or refractory, CD25+ and CD25- B-cell NHL and is well-tolerated at the dosage evaluated. Evaluation of denileukin diftitox in combination with other agents may be warranted.  相似文献   
24.
PURPOSE: To assess the health status of the Hispanic population of Orange County, Florida. METHODS: The methodology utilized secondary data for 66 ethnically identified indicators in a comparative framework applied for a 5-year period (1997-2001). FINDINGS: Orange County Hispanics are younger with lower per capita income than their Florida peers, less likely to be White, and much more likely to be of Puerto Rican origin. Relative to the Hispanic populations in the selected peer counties and statewide, Orange County Hispanics have higher age-adjusted death rates for a majority of disease categories and conditions, such as breast, lung, and prostate cancers; chronic liver disease and cirrhosis; diabetes mellitus; pneumonia and influenza; stroke; acquired immunodeficiency syndrome; motor vehicle accidents; and infant, neonatal, and child mortality. Orange County Hispanics did better in comparison to Orange non-Hispanics, with lower age-adjusted death rates for major causes of death such as heart disease, cancer, and stroke. However, for many indicators, the 5-year trends for Orange County Hispanics are moving in an unfavorable direction in contrast to the trends for non-Hispanics, which are either stable or improving. CONCLUSION: Comparative assessments of Hispanic populations using secondary data enable the development of a comprehensive health status profile. However, this approach is currently constrained by the limited number of ethnically identified indicators and, especially for Hispanics, problems in the accuracy and consistency of the assignment to racial categories and subsequent reporting.  相似文献   
25.
Community-university partnerships for research and action are at the heart of many fields in the social sciences including public health, urban planning, education, and community psychology. These partnerships involve individuals from different backgrounds and disciplines working together to address social issues of importance to the community. This article proposes an interactive and contextual model for developing and sustaining community-university partnerships. The phases in the model include gaining entry into the community, developing and sustaining a mutual collaboration (developing trust and mutual respect, establishing adequate communication, respecting human diversity, establishing a culture of learning, respecting the culture of the setting and the community, and developing an action agenda), and recognizing the benefits and outcomes of partnership work. The model also includes the potential challenges that might threaten the partnership, such as resource inequality and time commitment.  相似文献   
26.
A P-ethoxy oligonucleotide (oligo), 20 bases long and specific for the translation initiation site of human Bcl-2 mRNA, was incorporated into liposomes to increase its intracellular delivery. This oligo selectively inhibited Bcl-2 protein expression and induced growth inhibition in t(14;18)-positive transformed follicular lymphoma (FL) cell lines. We studied the inhibitory effects of shorter liposomal P-ethoxy oligos (7, 9, 11 or 15 mer) in order to determine the activity of different oligo chain lengths targeted to the same Bcl-2 mRNA. At 12 μM, all the oligos inhibited the growth of a FL cell line. We compared the 7-mer oligo with the 20-mer oligo. The two oligos inhibited Bcl-2 protein expression similarly: 66% and 60% for the 7- and 20-mer, respectively. The uptake and retention of both oligos were also very similar. Our results indicate that the Bcl-2 inhibitory activity is maintained with P-ethoxy antisense oligos ranging from 7 to 20 bases.  相似文献   
27.
目的 评估VERIS mfERG (EDI Inc)和Espion multifocal imager (Diagnosys)两种不同系统测量正常眼多焦视网膜电图(mfERG)的电位波反应的差异及其相关性,并用两个不同系统分别测量黄斑前膜患眼的mfERG并进行分析.方法 这是一项横断面研究,在VERIS系统使用Burian-Allen (BA)电极,Espion系统使用BA和DTL电极分别测量25只正常眼的mfERG,将3次测得的一阶反应的相应数据进行配对t检验及Pearson相关分析.两个系统用BA电极分别测量19只黄斑前膜患眼的mfERG,对一阶反应的相应数据进行Fisher's exact test分析.结果 VERIS BA测得正常眼N1波、P1波振幅密度值最大,其次为Espion BA,Espion DTL最小;VERIS BA测得N1波、P1波潜伏期最长,Espion BA与Espion DTL差异无统计学意义.Espion BA与VERIS BA测得的P1波振幅密度、潜伏期皆有明显的相关性.黄斑前膜患眼中,VERIS BA比Espion BA能检测到更多P1波振幅密度和P1波潜伏期的异常.结论 不论VERIS或Espion系统都能成功记录多焦视网膜电图,当两种系统都使用Burian-Allen电极时,两者mfERG一阶反应P1波振幅密度及潜伏期有着良好的相关性.  相似文献   
28.
29.
30.
BackgroundRespiratory syncytial virus (RSV)‐associated acute respiratory infection (ARI) is an underrecognized cause of illness in older adults. We conducted a systematic literature review and meta‐analysis to estimate the RSV disease burden in adults ≥60 years in high‐income countries.MethodsData on RSV‐ARI and hospitalization attack rates and in‐hospital case fatality rates (hCFR) in adults ≥60 years from the United States, Canada, European countries, Japan, and South Korea were collected based on a systematic literature search (January 1, 2000–November 3, 2021) or via other methods (citation search, unpublished studies cited by a previous meta‐analysis, gray literature, and an RSV‐specific abstract booklet). A random effects meta‐analysis was performed on estimates from the included studies.ResultsTwenty‐one studies were included in the meta‐analysis. The pooled estimates were 1.62% (95% confidence interval [CI]: 0.84–3.08) for RSV‐ARI attack rate, 0.15% (95% CI: 0.09–0.22) for hospitalization attack rate, and 7.13% (95% CI: 5.40–9.36) for hCFR. In 2019, this would translate into approximately 5.2 million cases, 470,000 hospitalizations, and 33,000 in‐hospital deaths in ≥60‐year‐old adults in high‐income countries.ConclusionsRSV disease burden in adults aged ≥60 years in high‐income countries is higher than previously estimated, highlighting the need for RSV prophylaxis in this age group.  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