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   1220篇
  免费   92篇
  国内免费   9篇
耳鼻咽喉   12篇
儿科学   73篇
妇产科学   13篇
基础医学   112篇
口腔科学   33篇
临床医学   117篇
内科学   293篇
皮肤病学   32篇
神经病学   36篇
特种医学   243篇
外科学   81篇
综合类   71篇
预防医学   74篇
眼科学   25篇
药学   51篇
中国医学   14篇
肿瘤学   41篇
  2024年   8篇
  2023年   8篇
  2022年   5篇
  2021年   6篇
  2020年   10篇
  2019年   13篇
  2018年   18篇
  2017年   12篇
  2016年   10篇
  2015年   24篇
  2014年   41篇
  2013年   65篇
  2012年   34篇
  2011年   37篇
  2010年   41篇
  2009年   66篇
  2008年   37篇
  2007年   58篇
  2006年   38篇
  2005年   36篇
  2004年   28篇
  2003年   20篇
  2002年   22篇
  2001年   14篇
  2000年   18篇
  1999年   21篇
  1998年   78篇
  1997年   53篇
  1996年   64篇
  1995年   45篇
  1994年   49篇
  1993年   44篇
  1992年   9篇
  1991年   7篇
  1990年   15篇
  1989年   39篇
  1988年   28篇
  1987年   26篇
  1986年   19篇
  1985年   12篇
  1984年   16篇
  1983年   16篇
  1982年   15篇
  1981年   20篇
  1980年   13篇
  1979年   8篇
  1978年   9篇
  1977年   17篇
  1976年   8篇
  1975年   13篇
排序方式: 共有1321条查询结果,搜索用时 31 毫秒
991.
In a study published in the current issue of the Journal of Geriatric Cardiology, Ang and co-investigators used the highresolution 64-slice CT coronary angiography to detect coronary lesions in a group of patients with atypical angina.1 The clinical data of these patients were also used to calculate their risk according the Framingham and PROCAM scoring system.2,3 As the cohort is composed with a majority of low risk patients with atypical angina, only a small minority of the patients were classified as having medium and high risk. The results showed that MDCT uncovered 18% either significant lesions (>50% stenosis) or calcifications (>400Agatston units)in the low risk patients and 33% in the medium and high risk subgroups.……  相似文献   
992.
Hyland  CA; Wolter  LC; Liew  YW; Saul  A 《Blood》1994,83(2):566-572
Polymorphisms within the Rh blood group system have been defined by serologic agglutination methods, but have not yet been defined at the DNA level. Two closely related genes associated with the Rh D antigen and with the Rh C/c and E/e antigens have been cloned. We used a Southern analysis incorporating probes to the 5' and 3' regions of the Rh C, E gene and D gene to identify polymorphisms associated with Rh C/c and E/e antigens, respectively. The D gene dosage could be determined by comparing the relative intensities of the D bands with bands from the 5' and 3' region of the Rh C, E gene. The concordance between restriction fragment length polymorphism (RFLP) patterns and serologic phenotypes for 102 randomly selected blood donors was 100% for C, e, and D, 94.8% for c, and 94.3% for E. The data are consistent with the sequences encoding the C/c epitopes residing on the 5' side of those for the E/e epitopes. All samples discordant for the 3' probe and E had the cE (r") serotype. These data show that the gene coding for the cE serotype is different in Rh-positive and -negative individuals. The study demonstrates that Rh DNA typing, including D gene dosage measurements and Rh gene haplotyping, may supplement traditional serotyping methods in transfusion medicine.  相似文献   
993.
994.
In some alcohol-related pathologies of chronic alcoholism women are more vulnerable than men. A consecutive sample of 62 chronic alcoholics was studied, 18 females and 44 males, aged between 28 and 69 years to assess the incidence and distribution of peripheral neuropathy with regard to gender. All patients underwent clinical and neurological observations, laboratory tests, and electroneurography. Total lifetime dose of ethanol (TLDE) and other risk factors for neuropathy (disease duration, age, nutritional status) were calculated and correlated to sural nerve sensory-evoked potential (SEP) amplitude. In 42 patients (67.7%), we observed the presence of clinical and/or infraclinical neuropathy, mostly axonal, in 29 males (65.9%) and 13 females (72.2%). In women, compared to men, TLDE and disease duration were significantly inversely correlated to sural nerve SEP amplitude, i.e in women, SEP amplitude is significantly reduced in relation to TLDE and disease duration increase. These data indicate a higher sensitivity of females towards the toxic effects of ethanol, other than malnutrition, on peripheral nerve fibres.  相似文献   
995.
996.
997.
Objective Following the publication of results of large-scale clinical trials, antiretroviral treatment for HIV has changed dramatically. The aim of this study was to describe changes in antiretroviral treatment and the way treatments were combined among 1806 patients with HIV seen at a single centre at the Royal Free Hospital, London, UK.
Design and method Each calendar year was divided into quarters, and the number of patients receiving treatment and participating in clinical trials was determined.
Results The proportion of patients on no therapy decreased from over 90% at the beginning of 1988 to under 15% at the end of 1997. Monotherapy was the only form of treatment available before 1992 but its use dropped to 2% by the end of 1997. The standard of care at the end of 1997 was triple combination therapy, used in over 40% of patients. There were dramatic changes in the use of individual agents; use of zidovudine decreased from 50% during 1989 to 25% during 1997, while use of lamivudine and stavudine saw an exponential rise in 1997. The protease inhibitors were used in equal proportions in this clinic population; the use of dual protease therapy began in 1997 and was rising rapidly by the end of the year.
Conclusions There have been major changes in the use of antiretroviral therapy at this centre, particularly during 1996 and 1997. The long-term cost implications and side-effects of intensive treatment regimens remain to be addressed.  相似文献   
998.
Angiogenesis is an essential process for the expansion of multiple myeloma (MM), in which many angiogenic factors participate. Endoglin (CD105) is a transforming growth factor‐β co‐receptor, being mainly expressed in angiogenic endothelial cells and has been used as a marker of tumor angiogenesis, having prognostic potential. The aim of the study was to evaluate serum levels of soluble CD105 (sCD105) in MM patients, both during diagnosis and after effective conventional chemotherapy, in the plateau phase, and to correlate them with the clinical stage of the disease, as well as with the known angiogenic factors vascular endothelial growth factor, angiogenin and interleukin‐18 (IL‐18). Serum levels of the aforementioned factors were measured, by enzyme‐linked immunosorbent assay, in 56 newly diagnosed MM patients, in 35 of them who entered plateau phase and in 24 healthy controls. Bone marrow aspirations were also performed in all patients to determine plasma cell infiltration. All measured cytokines were higher in MM patients compared with controls and with advancing disease stage (p < 0.001 for all cases). Furthermore, the values of all factors decreased significantly in the plateau phase (p < 0.001 for all cases). Serum levels of sCD105 correlated with the other angiogenic cytokines, whereas only serum levels of angiogenin had prognostic value for the survival. In conclusion, CD105 and the angiogenic cytokines vascular endothelial growth factor, angiogenin and IL‐18, seem to have emerging roles both in angiogenesis and tumor growth in MM. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
999.
The method of executive compensation in the Canadian public health system presently contains complex ethical issues related to transparency and fairness, not only within single organizations, but across provinces, and in comparison with other wage earners. The increasing interest of the public, elected officials, and health decision makers in public sector compensation will bring heightened scrutiny and intervention in the future. This article explores some of the current ethical issues of executive compensation and their implications and points to reform initiatives for the future.  相似文献   
1000.
Stratakis CA, Tichomirowa MA, Boikos S, Azevedo MF, Lodish M, Martari M, Verma S, Daly AF, Raygada M, Keil MF, Papademetriou J, Drori‐Herishanu L, Horvath A, Tsang KM, Nesterova M, Franklin S, Vanbellinghen J‐F, Bours V, Salvatori R, Beckers A. The role of germline AIP, MEN1, PRKAR1A, CDKN1B and CDKN2C mutations in causing pituitary adenomas in a large cohort of children, adolescents, and patients with genetic syndromes. The prevalence of germline mutations in MEN1, AIP, PRKAR1A, CDKN1B and CDKN2CI is unknown among pediatric patients with pituitary adenomas (PA). In this study, we screened children with PA for mutations in these genes; somatic GNAS mutations were also studied in a limited number of growth hormone (GH) or prolactin (PRL)‐secreting PA. We studied 74 and 6 patients with either isolated Cushing disease (CD) or GH‐ or PRL‐secreting PA, respectively. We also screened four pediatric patients with CD, and four with GH/PRL‐secreting tumors who had some syndromic features. There was one AIP mutation (p.Lys103Arg) among 74 CD patients. Two MEN1 mutations that occurred in patients with recurrent or difficult‐to‐treat disease were found among patients with CD. There was one MEN1 and three AIP mutations (p.Gln307ProfsX104, p.Pro114fsX, p.Lys241X) among pediatric patients with isolated GH‐ or PRL‐secreting PA and one additional MEN1 mutation in a patient with positive family history. There were no mutations in the PRKAR1A, CDKN1B, CDKN2C or GNAS genes. Thus, germline AIP or MEN1 gene mutations are frequent among pediatric patients with GH‐ or PRL‐secreting PA but are significantly rarer in pediatric CD; PRKAR1A mutations are not present in PA outside of Carney complex.  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