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   1605篇
  免费   89篇
  国内免费   19篇
耳鼻咽喉   22篇
儿科学   54篇
妇产科学   20篇
基础医学   177篇
口腔科学   7篇
临床医学   148篇
内科学   315篇
皮肤病学   27篇
神经病学   142篇
特种医学   84篇
外科学   279篇
综合类   23篇
预防医学   136篇
眼科学   49篇
药学   106篇
中国医学   1篇
肿瘤学   123篇
  2023年   17篇
  2022年   30篇
  2021年   53篇
  2020年   30篇
  2019年   47篇
  2018年   48篇
  2017年   27篇
  2016年   33篇
  2015年   57篇
  2014年   59篇
  2013年   76篇
  2012年   117篇
  2011年   126篇
  2010年   73篇
  2009年   80篇
  2008年   103篇
  2007年   88篇
  2006年   84篇
  2005年   86篇
  2004年   67篇
  2003年   77篇
  2002年   61篇
  2001年   23篇
  2000年   32篇
  1999年   27篇
  1998年   13篇
  1997年   13篇
  1996年   4篇
  1995年   4篇
  1994年   6篇
  1993年   6篇
  1992年   13篇
  1991年   11篇
  1990年   8篇
  1989年   8篇
  1988年   4篇
  1987年   3篇
  1986年   5篇
  1985年   9篇
  1984年   7篇
  1983年   13篇
  1982年   4篇
  1979年   8篇
  1978年   3篇
  1976年   3篇
  1975年   3篇
  1974年   5篇
  1973年   4篇
  1972年   6篇
  1971年   9篇
排序方式: 共有1713条查询结果,搜索用时 0 毫秒
71.
The purpose of the study is to present the favorable results of YAG: Nd laser capsulotomy for the treatment of secondary opacification of the posterior capsule, in our department. A 3 years retrospective study was performed. For 1440 cataract operations, most of them extracapsular extractions with PMMA IOL placed in the posterior chamber (ciliary sulcus or capsular bag), 285 laser capsulotomies were done. The results are presented statistically, including sex and age distribution, type of cataract surgery and implant, treatment protocol (number of sessions, number of impulses per session, energy per impulse) and complications. The frequency of secondary capsular opacification in our study is 19.78%. It is most important in the age group 60-70 years, where the surgery for cataract is performed more often. Capsulotomy was done after extracapsular extraction with IOL placed in the posterior chamber, but especially after extracapsular extraction without implant placement or with complications that have permitted only the use of an anterior chamber implant. Capsulotomy is performed in only one session in 88% of the cases. The energy per impulse is usually 3-5 mJ and the mean number of impulses per session is 10-30. There are few complications: transient elevation of intraocular pressure in 14.73%, discrete laser marks on the implant in 8.77% and moderate iritis in 1% of the cases. YAG: Nd laser capsulotomy appears to be a safe and efficient method of treating secondary cataract; it improved visual acuity in all cases, if different ocular pathology had not influenced it.  相似文献   
72.
PURPOSE: The literature on assessment of quality of life from 1993 to 2001 was reviewed to evaluate and compare existing measures through their psychometric value and make adequate recommendations on their clinical use and future research. MATERIALS AND METHODS: We selected quality of life articles and abstracts from Current Content 1996 to 1997 and MEDLINE 1993 to 1996 for our first report presented at the first consultation on incontinence in Monaco in 1998. This report was then updated up to September 2001 using the same strategy. We made our recommendations based on our clinical and research experience with these tools. RESULTS: Several quality of life generic or disease specific questionnaires have been published for male and female urinary incontinence. However, their psychometric value is far from uniform and for most of them responsiveness is weak or has never been reported. CONCLUSIONS: Few quality of life questionnaires are at an advanced enough stage of development to be applied in clinical practice. However, even with these questionnaires more study remains to be done to make them shorter, sometimes even more specific and easier to use in different populations.  相似文献   
73.
Hypertension is present in epidemic proportion and is associated with a markedly increased risk of developing numerous cardiovascular disorders. All current treatment guidelines emphasise the role of nonpharmacological interventions, physical activity included, in the treatment of mild to moderate hypertension. A large number of studies have demonstrated that regular exercise reduces the incidence of hypertension. In addition to preventing hypertension, regular exercise has been found to lower blood pressure (10 mmHg average reduction in both systolic and diastolic pressure), improve lipoprotein-lipid profiles and insulin sensitivity. As part of the initial treatment, exercise is recommended for 12 months in patients with stage 1 hypertension, with no other coronary risk factors and no evidence of cardiovascular disease, and for as long as 6 months in those with other risk factor, but not diabetes. In patients with diabetes, cardiovascular disease or with stage 2 or 3 hypertension, drug therapy should be initiated first. Dynamic exercise of moderate intensity, 50-75% VO2max, (e.g. brisk walking, cycling) for 50-60 minutes, 3-5 times per week, is preferable to vigorous exercise because it appears to be more effective in lowering blood pressure. In addition to reducing hypertension, physical activity improves other cardiovascular risk factors.  相似文献   
74.
75.
Patients with cancer suffer from a multitude of symptoms. Effective treatment strategies are available for a number of the common symptoms. A major reason for inadequate symptom relief is lack of effective symptom assessment. Accurate assessment of symptoms is necessary before any treatment can be undertaken. Although there are many complexities involved in the assessment of symptoms, simple, effective tools are available for identification and scoring of symptoms in clinical practice. This review describes recent advances in the study of symptom assessment in cancer patients. Several common symptoms are presented individually, followed by an overview of efforts addressing the assessment of multiple symptoms. Also, new tools in the evaluation of symptoms, including computerbased questionnaires, are discussed.  相似文献   
76.
Zygomycosis   总被引:3,自引:0,他引:3  
Zygomycosis, an uncommon but frequently fatal mycosis caused by fungi of the class Zygomycetes, develops most commonly as an opportunistic disease. Successful therapy involves a combined approach based on early diagnosis, prompt institution of medical therapy, and extensive surgical debridement of all devitalized tissue. Given the rarity of this condition, novel therapeutic strategies have been limited and only tested on an individual basis. The use of high-dose lipid formulations of amphotericin B, prompt reversal of the underlying predisposing condition, and hyperbaric oxygen are the most common strategies that have shown potential value in the treatment of zygomycosis.  相似文献   
77.
More than ever, many young athletes are being encouraged to train intensely for sporting competitions from an early age. Compared with studies in adults, less is known about the physiological trainability of adolescents. The velocity of physical growth during the adolescent years makes research with a group of young athletes particularly difficult. The purpose of this review is to discuss a number of physiological issues that surround the performances of the adolescent athlete. Research has highlighted the role of growth hormone (GH) in the abrupt acceleration of linear growth that occurs during adolescence. In addition, GH has been shown to be sensitive to exercise following short term intervention studies. The reduced anaerobic power of the adolescent athlete compared with that of an adult athlete has been attributed to the intrinsic properties of the muscle that are yet to be fully understood. Resistance training studies in male adolescents, and to a lesser extent female adolescents, highlight the substantial relative strength gains that can be obtained. Aerobic trainability in young boys appears to improve markedly during the adolescent years. One of the most plausible explanations for this observation is the 'trigger hypothesis' which links increased aerobic improvements in adolescence with hormonal changes and substantial growth of the cardiorespiratory and musculoskeletal systems. Studies of aerobic trainability in adolescent girls are too scarce to be conclusive. An understanding of the impact of long term intensive training on adolescent athletes is difficult to ascertain because physical stresses vary both between and within sports. There is, however, limited evidence to suggest that 'intense' training does not impair normal growth, development or maturation. Adolescent athletes who experience rapid growth as well as large increases in training volumes may be vulnerable to overuse injuries.  相似文献   
78.
PURPOSE: To assess the Aspergillus galactomannan enzyme-linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in adult and pediatric oncohematologic patients. PATIENTS AND METHODS: The study was conducted in four patient groups: those with fever of unknown origin (FUO) during neutropenia, suspected pulmonary infection (PI), or nonpulmonary aspergillosis (NPA) and those undergoing surveillance (S) after hematopoietic stem-cell transplantation (HSCT). IA was classified as definite, probable, or possible, according to European Organization for Research and Treatment of Cancer/Mycosis Study Group definitions. RESULTS: A total of 3,294 serum samples were collected during 797 episodes (FUO, 261; PI, 297; NPA, 28; and surveillance, 211), and 153 episodes of IA were diagnosed (31 definite, 67 probable, and 55 possible). Three episodes were first suspected from galactomannan ELISA; the remaining 150 cases were diagnosed from clinical or radiologic evidence. Sensitivity of the ELISA was 64.5%, 16.4%, and 25.5% in definite, probable, and possible episodes of IA, respectively, and was lower in patients positive for anti-Aspergillus antibodies than in antibody-negative patients. Most false-positive results occurred in children and in allogeneic HSCT (allo-HSCT) patients. Overall specificity of the ELISA was 94.8%. It was lower in children compared with adults (P <.0001) and in allo-HSCT patients compared with non-allo-HSCT adults (P =.0002). Lowering the ELISA cutoff value from 1.500 to 0.700 seemed more relevant for non-allo-HSCT adults (sensitivity, 73.1%, 44.3%, and 44.7% in definite, probable, and possible IA, respectively; specificity, 94%). CONCLUSION: Galactomannan ELISA seems less sensitive than previously described, and sensitivity can be further reduced by the presence of anti-Aspergillus antibodies. A new cutoff value for the ELISA of 0.700 is proposed for non-allo-HSCT adults.  相似文献   
79.
80.
Erythropoietin production by macrophages in the regenerating liver   总被引:2,自引:0,他引:2  
The site of erythropoietin (Ep) production and/or storage in the rat liver was determined. A guinea pig anti-Ep was produced against purified rat Ep (64,096 +/- 4j064 IU/mg). This antibody was found to be highly specific using rocket immunoelectrophoresis, Ouchterlony gel diffusion methods, and immunoprecipitin reactions as well as Ep neutralization tests (capable of completely neutralizing up to 2,000 IU Ep/mg). This anti-Ep was labeled with either fluorescein for light microscopic study or ferritin for electron microscopy. Kupffer cells showed varying degrees of labeling after hepatectomy alone or hepatectomy combined with nephrectomy and/or hypoxia. Greatest labeling was seen in Kupffer cells of rats that were nephrectomized 48 hr posthepatectomy and kept at ambient pressure. No labeling of hepatocytes or vascular and bile duct endothelium was noted.  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