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   3247篇
  免费   330篇
  国内免费   29篇
耳鼻咽喉   16篇
儿科学   58篇
妇产科学   47篇
基础医学   332篇
口腔科学   151篇
临床医学   431篇
内科学   331篇
皮肤病学   34篇
神经病学   401篇
特种医学   38篇
外科学   101篇
综合类   255篇
一般理论   1篇
预防医学   966篇
眼科学   8篇
药学   287篇
  1篇
中国医学   12篇
肿瘤学   136篇
  2024年   14篇
  2023年   50篇
  2022年   90篇
  2021年   183篇
  2020年   158篇
  2019年   133篇
  2018年   140篇
  2017年   138篇
  2016年   135篇
  2015年   153篇
  2014年   229篇
  2013年   360篇
  2012年   195篇
  2011年   234篇
  2010年   161篇
  2009年   161篇
  2008年   153篇
  2007年   135篇
  2006年   134篇
  2005年   94篇
  2004年   84篇
  2003年   59篇
  2002年   47篇
  2001年   46篇
  2000年   26篇
  1999年   24篇
  1998年   31篇
  1997年   23篇
  1996年   17篇
  1995年   16篇
  1994年   14篇
  1993年   8篇
  1992年   11篇
  1991年   9篇
  1990年   6篇
  1989年   7篇
  1988年   9篇
  1986年   7篇
  1985年   10篇
  1984年   9篇
  1983年   10篇
  1982年   16篇
  1981年   8篇
  1980年   10篇
  1979年   8篇
  1978年   5篇
  1977年   6篇
  1976年   7篇
  1975年   6篇
  1971年   4篇
排序方式: 共有3606条查询结果,搜索用时 46 毫秒
91.
Williams syndrome (WS) is a neurogenetic disorder known for its “hypersocial” phenotype and a complex profile of anxieties. The anxieties are poorly understood specifically in relation to the social-emotional and cognitive profiles. To address this gap, we employed a Wechsler intelligence test, the Brief Symptom Inventory, Beck Anxiety Inventory, and Salk Institute Sociability Questionnaire, to (1) examine how anxiety symptoms distinguish individuals with WS from typically developing (TD) individuals; and (2) assess the associations between three key phenotypic features of WS: intellectual impairment, social-emotional functioning, and anxiety. The results highlighted intensified neurophysiological symptoms and subjective experiences of anxiety in WS. Moreover, whereas higher cognitive ability was positively associated with anxiety in WS, the opposite pattern characterized the TD individuals. This study provides novel insight into how the three core phenotypic features associate/dissociate in WS, specifically in terms of the contribution of cognitive and emotional functioning to anxiety symptoms.  相似文献   
92.
BackgroundThe aim was to assess the efficacy of antimicrobial photodynamic therapy (aPDT) in the treatment of aggressive periodontitis (AgP).MethodsThe addressed focused question was “Is aPDT effective in the treatment of AgP?” MEDLINE/PubMed, EMBASE, Scopus, ISI Web of knowledge and Google-Scholar databases were searched from 1977 till May 2015 using combinations of the following keywords: antimicrobial; photochemotherapy; photodynamic therapy; photosensitizing agents; AgP; scaling and root-planing (SRP). Reviews, case reports, commentaries, and articles published in languages other than English were excluded.ResultsSeven studies were included. In 5 studies, aPDT was performed as an adjunct to SRP. Laserwavelengths and duration of irradiation ranged between 660–690 nm and 60–120 s, respectively. Laser power output as reported in 2 studies was 75 mW. One study showed significant improvement in periodontal parameters for subjects receiving aPDT as an adjunct to SRP as compared to treatment with SRP alone at follow up. However, comparable periodontal parameters were reported when aPDT as an adjunct to SRP was compared to SRP alone in the treatment of AgP in one study. One study showed comparable outcomes when aPDT was compared to SRP in the treatment of AgP. In two studies, adjunctive antibiotic administration to SRP showed significantly better outcomes when compared to application of adjunctive use of aPDT to SRP.ConclusionaPDT is effective as an adjunct to SRP for the management of AgP, however, further randomized clinical trials with well defined control groups are needed in this regard.  相似文献   
93.
The optimum therapy for patients with relapsed or refractory aggressive non-Hodgkin’s lymphomas (NHL) not qualifying for platinum-based and/or high-dose chemotherapy is not known. We conducted a prospective phase II study evaluating a regimen consisting of gemcitabine (1 g/m2, days 1 and 8), vinorelbine (30 mg/m2, days 1 and 8) and prednisone (100 mg/day, days 1–8) (GVP) given every 21 days. Fifteen patients with a median age of 68 years and a median of three previous therapies were enrolled. Diagnoses included B lymphoblastic (n=1), diffuse large B cell (n=10), anaplastic large T cell (n=2) and peripheral T-cell NHL (n=2). The median international prognostic index score was 3 (six patients with a score of 4 or 5). Five patients achieved a complete remission and three patients a partial remission. The median overall survival was 13.8 months, and the median time to next treatment was 4.4 months. Haematological toxicities of World Health Organisation grades 3/4 were leucopenia in 58%, thrombocytopenia in 33% and anaemia in 17% of all courses. Three patients had grade 3 infections. There was no treatment-related mortality. GVP shows substantial activity in poor prognosis relapsed or refractory aggressive lymphomas and is generally well tolerated, but haematological toxicity is dose limiting.  相似文献   
94.
To assess factors that affect the adoption of healthy lifestyles among a variety of active Israeli seniors, a survey was conducted in 2002 at the Peiluyada, a physical activity-oriented health fair for seniors held annually in Israel from 1995 to 2002. A multi-language, self-administered questionnaire, assessing predisposing factors, barriers and health-protective behaviors, was fielded to potential participants. Response rate at the event was 51%. Hebrew and Arabic speakers generally characterized their health as good to very good, while Russian speakers' health was rated only poor to fair. Over 80% engaged in regular physical activity, were satisfied with their diet, and conformed to international nutritional recommendations. Vaccination coverage against influenza (81%) and pneumocccocus (58%) was highest among Arabic speakers, and lowest among Russian speakers (33.5% and 12%, respectively). Higher age (> or =75 years) was significantly associated with receiving a vaccination against influenza. Major barriers to exercise included low motivation and poor physical health or disability. Health-related dietary restrictions were the leading nutritional barrier. Prominent barriers to vaccination included concerns about vaccine effectiveness (39%) and side effects (29%). Leading cues to action were a recommendation from one's doctor (67%) and from a healthcare worker (51%).  相似文献   
95.

Background and Aims

Physical inactivity, unhealthy diet, smoking and heavy drinking are four key unhealthy lifestyle behaviors (ULB) that may influence body weight and obesity development. More recently, sedentary time has been recognized as another potentially emerging ULB related to obesity. We therefore investigated the association of multiple ULB with overweight/obesity and abdominal obesity among Brazilian adolescents.

Methods and Results

This cross-sectional study involved 62,063 students (12–17 years). Physical inactivity, high screen time, low fiber intake, binge drinking and smoking were self-reported and combined to a ULB risk score, ranging from zero to five. Participants were classified as overweight/obese or with abdominal obesity using sex and age-specific cut-off points for BMI and waist circumference, respectively. Poisson regression models were used to examine the associations between ULB with overweight/obesity and abdominal obesity, adjusted for socio-demographic variables. Overall, 2.3%, 18.9%, 43.9%, 32.3% and 2.6% of participants reported zero, one, two, three and four/five ULB, respectively. Higher ULB risk score was associated with overweight/obesity and abdominal obesity in a dose–response gradient. Among 32 possible combinations of ULB, the three most prevalent combinations (physical inactivity + low fiber intake; high screen time + low fiber intake; physical inactivity + high screen time + low fiber intake) were positively associated with general and abdominal obesity.

Conclusions

Our findings suggest a synergistic relationship between ULB and general and abdominal obesity. Preventive efforts targeting combined ULB should be sought to reduce the prevalence of general and abdominal obesity in Brazilian youth.  相似文献   
96.
This study investigates continuing risk behaviors among HIV-seropositive chronic drug users in Miami, Florida. Data were collected on 490 injecting and noninjecting seropositive drug users. Results indicate that from baseline to follow-up, HIV-seropositive injectors and non-injectors reported significant decreases of approximately 50% in risky sexual and injecting practices (IDUs only) associated with transmission of HIV. However, our findings also indicate that approximately one third of HIV-positive injectors and one half of HIV-positive noninjectors continue to have unprotected sex and one third of HIV-positive injectors are continuing to engage in risky injecting practices. Change in one risk behavior was predictive of change in other risk behaviors. Women were more likely to change injection behaviors than sexual practices. Injecting drug users showed greater overall behavioral change than noninjectors. These findings underscore the need to develop, disseminate, and implement effective intervention models specifically targeting HIV-positive drug users.  相似文献   
97.
摘 要 目的:分析神经节苷脂钠注射液出现聚集性不良反应的影响因素。方法:调阅本院ADR/ADE 监测系统内的7份神经节苷脂注射液聚集性不良反应记录及相关病历,对用药人群、使用环节、ADR症状等因素进行调查分析。结果:经质量检验,此次使用的神经节苷脂注射液为合格药品,此次聚集性不良反应表现为抽搐、寒战、发热等过敏样症状。7例聚集性不良反应的发生时间、溶媒选择、药物用量、滴速等因素基本相同,仅在溶媒用量、合并用药方面存在差异。结论:导致聚集性不良反应发生的影响因素很多,难以确定某个具体因素。聚集性ADR一旦发现,应立即停药,及时上报,寻找原因,推动药品质量不断提高和临床用药不断规范。  相似文献   
98.
99.
China’s HIV epidemic may be shifting towards predominantly sexual transmission and emerging data point to potential increases in HIV prevalence among men who have sex with men (MSM). There is particular need to assess the extent of risk behavior among MSM outside of China’s most cosmopolitan cities. We conducted a respondent-driven sampling survey (N = 428) to measure HIV seroprevalence and risk behavior among MSM in Jinan, China, the provincial capital of Shandong. HIV prevalence was 0.5% (95% confidence interval [CI] 0.1–1.0). Unprotected anal intercourse (UAI) in the last 6 months (reported by 61.4%) was associated with buying or selling sex to a man in the last 6 months, syphilis infection, multiple partners in the last month, low HIV knowledge and migrant status. No participant had previously tested for HIV. Risk for HIV transmission is widespread among MSM throughout China; basic prevention programs are urgently needed.  相似文献   
100.
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