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   220篇
  免费   19篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   3篇
基础医学   23篇
口腔科学   2篇
临床医学   50篇
内科学   47篇
皮肤病学   3篇
神经病学   6篇
特种医学   8篇
外科学   28篇
综合类   15篇
预防医学   25篇
眼科学   2篇
药学   6篇
肿瘤学   11篇
  2022年   3篇
  2017年   6篇
  2014年   2篇
  2013年   6篇
  2012年   3篇
  2011年   6篇
  2010年   5篇
  2009年   6篇
  2008年   11篇
  2007年   6篇
  2006年   6篇
  2005年   5篇
  2004年   3篇
  2003年   11篇
  2002年   7篇
  2001年   5篇
  2000年   5篇
  1999年   2篇
  1998年   8篇
  1997年   4篇
  1996年   4篇
  1994年   2篇
  1993年   3篇
  1992年   8篇
  1991年   5篇
  1990年   4篇
  1989年   3篇
  1988年   7篇
  1987年   6篇
  1986年   5篇
  1985年   8篇
  1984年   3篇
  1983年   4篇
  1982年   5篇
  1980年   2篇
  1979年   3篇
  1978年   4篇
  1976年   2篇
  1972年   2篇
  1971年   3篇
  1970年   2篇
  1966年   2篇
  1965年   2篇
  1964年   2篇
  1958年   4篇
  1947年   2篇
  1945年   3篇
  1941年   2篇
  1940年   4篇
  1931年   2篇
排序方式: 共有239条查询结果,搜索用时 15 毫秒
1.
2.
A Vernon  M H Hoagland  E J Perlman 《JAMA》1987,258(15):2063-2064
  相似文献   
3.
Schick  PK; Wojenski  CM; Bennett  VD; Ivanova  T 《Blood》1996,87(5):1817-1823
There are several species of alternatively spliced fibronectin (FN). One of these, FN EIIIB, is primarily present in embryonic and in proliferating and migrating cells and is believed to be important for cell maturation. We have studied the synthesis, localization, and secretion of this FN isoform in isolated guinea pig megakaryocytes, nonmegakaryocytic bone marrow cells, and platelets. There was 7.5 times more general FN in megakaryocytes than in nonmegakaryocytic cells based on the analysis of equivalent amounts of protein. FN EIIIB was detected by Western blotting in megakaryocytes but not in nonmegakaryocytic cells present in bone marrow. Neither megakaryocytes nor platelets secreted FN EIIIB, while megakaryocytes secreted 25.3% +/- 4.6% general FN and platelets secreted about 61% general FN in response to thrombin. Analysis of immunostained cells by confocal microscopy revealed that FN EIIIB had been redistributed to the surface of megakaryocytes in response to thrombin. Synthesis was studied by metabolic labeling, and megakaryocytes were shown to synthesize FN and FN EIIIB. Thus, megakaryocytes and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. The expression of FN EIIIB on the megakaryocyte surface may influence migration and maturation.  相似文献   
4.
5.
Institutions across the country are considering the feasibility of a disease management program for heart failure (HF) patients. Published reports suggest that such programs can save money and improve outcomes. However, the design of a disease management program can be challenging. This paper describes the structure and function of a successful disease management program for heart failure patients. The program is supported by a multidisciplinary team of nurses, pharmacists, dietitians, social workers, and physicians who approach the problem from a self care perspective. Program components include standardized educational materials, reinforcement of educational contacts, monthly support groups, and a quarterly newsletter. Existing staff built the program with few additional resources and staff. The program, which costs only approximately $330/patient for a 6 month intervention, has decreased hospital readmissions (29%) and days in the hospital (43%) significantly. (c)1999 by CHF, Inc.  相似文献   
6.
Summary A recently described separation technique consisting of a combination of counterflow centrifugation and subsequent density (Percoll) scparation was tested for its ability to enrich red cell populations with young cells in comparison to either separation technique alone. The relative age of every fraction was determined by HbAlc measurements, resulting in the lowest HbAlc for the combination method. Conventional reticulocyte counting and floweytometric counting with thiazole orange indicated that in the youngest fractions the combination method showed the highest reticulocyte counts. There was a good correlation between manual and flowcytometric counting results. Radio-iron studies showed a two-fold enrichment with young cells in the fraction with the lowest HbAIc acquired by the combination technique in comparison to the other two methods. Cytometric measurements showed that the fractions with the lowest HbAlc were the ones with the highest MCV and MCH and the lowest MCHC. Besides loss of their RNA-material, young cells already seem to loose water and haemoglobin like older cells, resulting in a decrease of MCV and MCH and in increase in MCHC. It is concluded that combining counterflow centrifugation with subsequent density fractionation results in superior enrichment with young cells in comparison to the results of each method alone.  相似文献   
7.
8.
9.
ABSTRACT

Brazil has the largest population of individuals living with HIV/AIDS in Latin America with a disproportional prevalence of infection among men who have sex with men (MSM). This study evaluated PrEP awareness by age (18–24, 25–35, ≥36 years), its associated factors and the willingness to use HIV prevention technologies among MSM using a GSN app in Brazil. Inclusion criteria were ≥18 years-old, cisgender men and HIV-negative serostatus. Of 7242 individuals, 4136 (57%) completed the questionnaire. PrEP awareness was reported by 51% (though lower among MSM aged 18–24 and ≥36 years) and its associated factors were higher family income, most friends with the same sexual orientation, high number of male sexual partners and marijuana use. HIV testing (never vs. at least once) lead to an almost 3-fold increase in the odds of PrEP awareness. High HIV risk perception led to increased PrEP awareness only among MSM aged 18–24 years. A total of 2335 (56%) was willing to use daily oral PrEP. PrEP awareness remains low in Brazil and mobile tools are key strategies to reach MSM and increase awareness of prevention technologies. Community-based interventions could add to online campaigns to reach the most vulnerable, which include young, non-white and lower-income MSM.  相似文献   
10.
It has been possible by means of classical chemical methods to isolate and to characterize to some extent the nucleic acid of elementary bodies of vaccinia. Determination by means of diphenylamine reagent revealed that the major part of the nucleic acid was of the thymus type. This was further substantiated by its stability in the presence of ribonuclease, less than 10 per cent undergoing depolymerization during prolonged incubation at 37°C. By the technique employed, at least 5.6 per cent of the virus was shown to be thymonucleic acid. This amount agreed favorably with the value calculated from the non-lipid organic phosphorus of elementary bodies on the assumption that the phosphorus bound in the organic form was derived principally from nucleic acid.  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