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   441篇
  免费   33篇
耳鼻咽喉   13篇
儿科学   18篇
妇产科学   3篇
基础医学   62篇
口腔科学   19篇
临床医学   18篇
内科学   121篇
皮肤病学   5篇
神经病学   16篇
特种医学   3篇
外科学   69篇
预防医学   95篇
眼科学   7篇
药学   11篇
中国医学   3篇
肿瘤学   11篇
  2023年   1篇
  2022年   14篇
  2021年   13篇
  2020年   8篇
  2019年   10篇
  2018年   13篇
  2017年   9篇
  2016年   10篇
  2015年   3篇
  2014年   9篇
  2013年   14篇
  2012年   33篇
  2011年   39篇
  2010年   15篇
  2009年   6篇
  2008年   30篇
  2007年   27篇
  2006年   30篇
  2005年   25篇
  2004年   30篇
  2003年   24篇
  2002年   18篇
  2001年   9篇
  2000年   10篇
  1999年   9篇
  1998年   2篇
  1997年   5篇
  1996年   6篇
  1993年   2篇
  1992年   4篇
  1991年   9篇
  1990年   2篇
  1989年   4篇
  1988年   1篇
  1987年   3篇
  1986年   5篇
  1985年   1篇
  1984年   6篇
  1983年   1篇
  1982年   4篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   2篇
  1975年   1篇
  1972年   2篇
  1969年   1篇
排序方式: 共有474条查询结果,搜索用时 15 毫秒
91.
This paper describes the use of program‐monitoring data to track program performance and inform activities. Monitoring data were collected as part of an effectiveness trial of multiple micronutrient powders (MNPs) for children 6–18 months in Bihar, India. Communities (n = 70; reaching over 10,000 children) were randomized to receive either counselling on infant and young child feeding or both counselling and MNPs. Government frontline health workers (FLWs) implemented and monitored program activities with support from CARE India and university partners. Monitoring data were collected over the duration of the entire program to assess program impact pathways using various checklists, which captured information about (a) attendance and training of FLWs at health subcentre meetings, (b) distribution of MNPs, (c) receipt and use of MNPs at the household level, and (d) midline mixed methods survey. At the beginning of the program, 72% of households reported receiving and 53% reported currently consuming MNPs. These numbers fell to 40% and 43% at midline, respectively. The main barrier to use by household was a lack of MNPs, due in part to infrequent FLW distribution. However, FLWs rarely reported MNP shortages at Anganwadi centres. Side effects also emerged as a barrier and were addressed through revised recommendations for MNP use. Qualitative data indicated high community acceptance of MNPs and a good understanding of the program by FLWs. The use of real‐time program data allowed for recognition of key program issues and decision‐making to enhance program implementation.  相似文献   
92.
Although Mycobacterium tuberculosis is eradicated rapidly during therapy in some patients with pulmonary tuberculosis, it can persist for many months in others. This study examined the relationship between mycobacterial drug tolerance (delayed killing in vitro), persistence, and relapse. It was performed with 39 fully drug-susceptible isolates from a prospective trial of standard short-course antituberculous therapy with sputum smear-positive, human immunodeficiency virus-uninfected subjects with pulmonary tuberculosis in Brazil and Uganda. The rate of killing in vitro was determined by monitoring the growth index (GI) in BACTEC 12B medium after addition of drug to established cultures and was measured as the number of days required for 99% sterilization. Drugs differed significantly in bactericidal activity, in the following order from greatest to least, rifampin > isoniazid-ethambutol > ethambutol (P < 0.001). Isolates from subjects who had relapses (n = 2) or in whom persistence was prolonged (n = 1) were significantly more tolerant of isoniazid-ethambutol and rifampin than isolates from other subjects (P < 0.01). More generally, the duration of persistence during therapy was predicted by strain tolerance to isoniazid and rifampin (P = 0.012 and 0.026, respectively). Tolerance to isoniazid-ethambutol and tolerance to rifampin were highly correlated (P < 0.001). Tolerant isolates did not differ from others with respect to the MIC of isoniazid; the rate of killing of a tolerant isolate by isoniazid-ethambutol was not increased at higher drug concentrations. These observations suggest that tolerance may not be due to drug-specific mechanisms. Tolerance was of the phenotypic type, although increased tolerance appeared to emerge after prolonged drug exposure in vivo. This study suggests that drug tolerance may be an important determinant of the outcome of therapy for tuberculosis.  相似文献   
93.
We sought to explore the immediate clinical and angiographic results of the Titan? stent implantation in diabetic patients, as well as the major adverse cardiac events (MACE) at 6-month follow-up. We enrolled 156 consecutive diabetic patients admitted to undergo percutaneous intervention for at least one significant (50%) coronary lesion. All lesions were treated with the Titan? stent implantation according to the contemporary interventional techniques. Patients were prospectively followed-up for at least 6?months. The primary endpoint was MACE at 6-month follow-up [cardiac death, myocardial infarction (MI), or target lesion revascularization (TLR)]. Secondary endpoints included angiographic and clinical procedural success, in-hospital MACE, TLR at 6-month follow-up, and stent thrombosis. The mean age was 66.7?±?9.6?years, (68.4% males). A total of 197 Titan? stents were implanted in 163 lesions. Direct stenting was performed in 45.2% of the cases. The mean stent diameter was 3.1?±?0.61?mm, and the mean length was 18.0?±?8.9?mm. Average stent deployment pressure was 13.9?±?4.2 bars. Angiographic procedural success was achieved in 154 (98.7%) cases, and clinical procedural success was achieved in 153 (98.1%) cases. One patient developed in-hospital non-Q-wave MI following the procedure. Clinical follow-up was completed in 155 (99.4%) patients. Three patients (1.9%) died of a cardiac or unknown cause, and two (1.3%) developed MI. TLR was performed in 11 patients (7.1%). Cumulative MACE at 6-month follow-up occurred in 16 (10.3%) patients. No patient suffered stent thrombosis. Titan? stent implantation in diabetic patients achieves an excellent immediate clinical and angiographic outcome, with a low incidence of MACE at mid-term follow-up.  相似文献   
94.
Lymphocytic choriomeningitis virus (LCMV) is an emerging neuroteratogen which can infect humans via contact with urine, feces, saliva, or blood of infected rodents. When the infection occurs during pregnancy, there is a risk of transplacental infection with subsequent neurological or visual impairment in the fetus. In this article, we describe a case report of congenital LCMV infection, including fetal imaging, confirmed by positive LCMV IgM in fetal blood and cerebrospinal fluid.  相似文献   
95.
Cytotoxic activity mediated by CD8+ T cells is the main signature of the immunopathogenesis of cutaneous leishmaniasis (CL). Here, we performed a broad evaluation of natural killer (NK) cell phenotypic and functional features during cutaneous leishmaniasis. We demonstrate for the first time that CL patients present the accumulation of circulating NK cells with multiple features of replicative senescence including low proliferative capacity and shorter telomeres, elevated expression of CD57, KLRG1 but diminished CD27 stimulatory receptor expression. Moreover, they exhibited higher cytotoxic and inflammatory potential than age-matched controls. The accumulation of circulating senescent NK cells (CD56dim CD57bright) correlated positively with skin lesion size in the same patients, suggesting that they, like circulating senescent CD8+ T cells, may contribute to the immunopathology of CL. However, this senescent population had lower cutaneous lymphocyte antigen expression and so had diminished skin-homing potential compared with total or senescent CD8+ T cells. This was confirmed in CL skin lesions where we found a predominance of CD8+ T cells (both senescent and non-senescent) that correlated with the severity of the disease. Although there was also a correlation between the proportions of senescent NK cells (CD56+ CD57+) in the skin and lesion size, this was less evident. Collectively our results demonstrate first-hand that senescent cytotoxic cells may mediate skin pathology during human cutaneous leishmaniasis. However, as senescent cytotoxic CD8+ T cells predominate in the skin lesions, they may have a greater role than NK cells in mediating the non-specific skin damage in CL.  相似文献   
96.
Complex regional pain syndrome (CRPS) associated with acute carpal tunnel syndrome (aCTS) developed in a 38-year-old right-handed man following radial artery cannulation (RAC) during the course of lumbar spine surgery. Inciting events and risk factors that might have led to these complications included: multiple arterial punctures and subsequent hematoma formation, radial artery spasm compounded by aggressive hemostasis, anatomical changes in the wrists related to repetitive manual activities in the workplace, and possible protracted hyperextension of the wrists during perioperative and operative procedure. Although CRPS is considered a rare complication of RAC, the condition is disabling and debilitating, especially when associated with aCTS.  相似文献   
97.
98.
Left ventricular myxoma is a rare benign cardiac tumor. Surgical excision is the treatment of choice and completeness of removal is mandatory to avoid late recurrence. A case is presented in which aortic transvalvular video-assisted cardioscopy was used to facilitate removal.  相似文献   
99.
BACKGROUND: Recent studies support a positive relationship between parity and overweight among women of developing countries; however, it is unclear whether these effects vary by household wealth and national development. Our objective was to determine whether the association between parity and overweight [body mass index (BMI) > or =25 kg/m(2)] in women living in developing countries varies with levels of national human development and/or household wealth. METHODS: We used data from 28 nationally representative, cross-sectional surveys conducted between 1996 and 2003 (n = 275 704 women, 15-49 years). The relationship between parity and overweight was modelled using logistic regression, controlling for several biological and sociodemographic factors and national development, as reflected by the United Nations' Human Development Index. We also modelled the interaction between parity and national development, and the three-way interaction between parity, household wealth and national development. RESULTS: Parity had a weak, positive association with overweight, which varied by household wealth and national development. Among the poorest women and women in the second tertile of household wealth, parity was positively related to overweight only in the most developed countries. Among the wealthiest women, parity was positively related to overweight regardless of the level of national development. CONCLUSIONS: As development increases, the burden of parity-related overweight shifts to include poor as well as wealthy women. In the least-developed countries, programmes to prevent parity-related overweight should target wealthy women, whereas such programmes should be provided to all women in more developed countries.  相似文献   
100.
Historically, the epidemiology of sexually transmitted diseases (STD) has been based on individual attributes and behavior. However, STD constitute a good example of diseases that depend on personal contacts for dissemination. Social network analysis is a relatively new technique that studies the interactions among people. Since 1985 when it was first used for STD, some studies have been done using the technique, especially in the last 10 years. The two network-based designs, sociocentric or complete networks and egocentric or personal networks, are currently recognized as important tools for a better understanding of STD's dynamic. Here an overview is presented of social network analysis: the technique, its use, and its limitations. Ethical considerations regarding social network analyses are also briefly discussed.  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