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   6254篇
  免费   444篇
  国内免费   11篇
耳鼻咽喉   93篇
儿科学   178篇
妇产科学   143篇
基础医学   796篇
口腔科学   63篇
临床医学   736篇
内科学   1213篇
皮肤病学   71篇
神经病学   627篇
特种医学   128篇
外科学   790篇
综合类   38篇
一般理论   14篇
预防医学   737篇
眼科学   164篇
药学   506篇
中国医学   4篇
肿瘤学   408篇
  2024年   7篇
  2023年   67篇
  2022年   92篇
  2021年   293篇
  2020年   153篇
  2019年   229篇
  2018年   236篇
  2017年   192篇
  2016年   199篇
  2015年   238篇
  2014年   297篇
  2013年   442篇
  2012年   605篇
  2011年   566篇
  2010年   261篇
  2009年   258篇
  2008年   431篇
  2007年   423篇
  2006年   372篇
  2005年   376篇
  2004年   284篇
  2003年   202篇
  2002年   202篇
  2001年   32篇
  2000年   17篇
  1999年   22篇
  1998年   36篇
  1997年   17篇
  1996年   17篇
  1995年   16篇
  1994年   10篇
  1993年   19篇
  1992年   20篇
  1991年   10篇
  1990年   11篇
  1989年   8篇
  1988年   8篇
  1987年   6篇
  1986年   6篇
  1985年   5篇
  1984年   8篇
  1983年   1篇
  1982年   3篇
  1980年   1篇
  1979年   2篇
  1978年   2篇
  1977年   3篇
  1976年   2篇
  1973年   1篇
  1965年   1篇
排序方式: 共有6709条查询结果,搜索用时 15 毫秒
61.
62.
Objective. To implement and assess a pharmacy dermatology and cosmeceutical compounding elective course and its impact on graduates’ careers.Design. A 3-credit elective course that incorporated classroom lectures on ambulatory dermatologic diseases and cosmeceutical products with case studies, weekly quizzes, and a comprehensive business plan project was implemented in a doctor of pharmacy (PharmD) program in 2010.Assessment. Assessment instruments including weekly quizzes, a business plan project, and pre- and post-course tests were used to evaluate course content. Across 3 offerings of the course (2010, 2011, 2012), pre- and post-course test scores improved. Results of a postgraduate survey showed that 54% of respondents worked at a pharmacy offering compounding services, and 57% felt that the course played a significant or very significant role in their counseling on dermatologic conditions.Conclusions. Assessment methods revealed student learning of course content and the course appeared moderately beneficial to graduates’ early careers. A more longitudinal analysis is needed to assess the course’s impact on long-term career choices, particularly those dealing with compounding of cosmeceutical products.  相似文献   
63.
Ageing is accompanied with a decline in respiratory function. It is hypothesised that this may be attenuated by high physical activity levels. We performed spirometry in master athletes (71 women; 84 men; 35–86 years) and sedentary people (39 women; 45 men; 24–82 years), and calculated the predicted lung age (PLA). The negative associations of age with forced expiratory volume in 1 s (FEV1; 34 mL·year?1) and other ventilatory parameters were similar in controls and master athletes. FEV1pred was 9 % higher (P?<?0.005) and PLA 15 % lower (P?=?0.013) in athletes than controls. There were no significant differences between endurance and power athletes and sedentary people in maximal inspiratory and expiratory pressure. Neither age-graded performance nor weekly training hours were significantly related to lung age. Life-long exercise does not appear to attenuate the age-related decrease in ventilatory function. The better respiratory function in master athletes than age-matched sedentary people might be due to self-selection and attrition bias.  相似文献   
64.
Light exerts a direct effect on sleep and wakefulness in nocturnal and diurnal animals, with a light pulse during the dark phase suppressing locomotor activity and promoting sleep in the former. In the present study, we investigated this direct effect of light on various sleep parameters by exposing mice to a broad range of illuminances (0.2–200 μW/cm2; equivalent to 1–1000 lux) for 1 h during the dark phase (zeitgeber time 13–14). Fitting the data with a three‐parameter log model indicated that ~0.1 μW/cm2 can generate half the sleep response observed at 200 μW/cm2. We observed decreases in total sleep time during the 1 h following the end of the light pulse. Light reduced the latency to sleep from ~30 min in darkness (baseline) to ~10 min at the highest intensity, although this effect was invariant across the light intensities used. We then assessed the role of melanopsin during the rapid transition from wakefulness to sleep at the onset of a light pulse and the maintenance of sleep with a 6‐h 20 μW/cm2 light pulse. Even though the melanopsin knockout mice had robust induction of sleep (~35 min) during the first hour of the pulse, it was not maintained. Total sleep decreased by almost 65% by the third hour in comparison with the first hour of the pulse in mice lacking melanopsin, whereas only an 8% decrease was observed in wild‐type mice. Collectively, our findings highlight the selective effects of light on murine sleep, and suggest that melanopsin‐based photoreception is primarily involved in sustaining light‐induced sleep.  相似文献   
65.
Problem: Student–preceptor discontinuity during 3rd-year clerkships limits the quality and quantity of supervision, teaching, and feedback. Although longitudinal integrative clerkships increase continuity and are associated with improved student and preceptor experience, they require schoolwide curricular reform. Alternative innovations enhancing student–preceptor relationships within the constraints of a traditional block clerkship may demonstrate similar benefits. Intervention: We piloted a continuity-enhanced general pediatric ambulatory schedule during 2 consecutive clerkship blocks in 2013. Students in the continuity-enhanced model (n = 29) were assigned 1–3 primary clinic preceptors, whereas those in the traditional model (n = 30) worked with 5–8. Data were gathered from student assessments and anonymous student and preceptor surveys. We used t and Fisher's exact tests to compare the two groups and performed thematic analysis of free-text survey comments. Context: Our school utilizes a block clerkship model with approximately 30 students rotating through the pediatric clerkship every 8 weeks. During the 3-week ambulatory portion, students spend 8 half days in the general pediatric ambulatory clinic. At the conclusion of each clinic, attendings completed brief student evaluation cards. Traditionally, student and attending schedules were created independently, resulting in transient supervisory relationships and dissatisfaction with clinical engagement, feedback, and evaluation. Outcome: Seventy-three percent (43/59) of the students completed the survey. Ten general ambulatory attendings collectively completed 87.5% (35/40) of the monthly surveys. Continuity students received significantly more narrative evaluation comments (10.6 vs. 5.8, p <. 001) from general ambulatory clinic attendings and were more likely to have at least one general ambulatory clinic attending endorse being able to provide meaningful feedback and evaluation (n = 29, 100% vs. n = 20, 66.7%, p <. 001). Continuity students were also more likely to endorse being able to ask at least one of these attendings for a letter of recommendation (71.4% vs. 9.1%, p <. 001) and to have at least one general ambulatory clinic attending endorse being able to provide a meaningful letter of recommendation if asked (62.1% vs. 3.3%, p <. 001). Students (88.4%) and attendings (85.7%) preferred the continuity-enhanced schedule. The most frequent theme of both student and attending free-text survey remarks were relationships and assessment. Lessons Learned: Intentional scheduling of clerkship students to enhance preceptor continuity resulted in significant positive outcomes echoing the relationship-based educational benefits of longitudinal clerkships, particularly in regards to student assessment and feedback. Clerkship directors and other medical educators should consider implementing small changes within block clerkships to maximize student–preceptor continuity.  相似文献   
66.
67.
Community-based support group participation protects against substance use disorder (SUD) relapse, but referrals during treatment are inconsistently delivered and may not acknowledge barriers facing rural patients. This formative evaluation of a rural intensive referral intervention (RAIR) to community-based support groups for Veterans seeking SUD treatment surveyed patients (n = 145) and surveyed and interviewed treatment staff (n = 28). Patients and staff did not differ significantly on quantitative ratings of the helpfulness of, or satisfaction with, seven RAIR components, but staff did not deliver the intervention consistently or as designed, citing two themes: lack of commitment and lack of resources.  相似文献   
68.
Efforts are underway to educate consumers about the dangers of smoking at the point of sale (POS). Research is limited about the efficacy of POS antismoking ads to guide campaign development. This study experimentally tests whether the type of antismoking ad and the context in which ads are viewed influence people’s reactions to the ads. A national convenience sample of 7,812 adult current smokers and recent quitters was randomized to 1 of 39 conditions. Participants viewed one of the four types of antismoking ads (negative health consequences—graphic, negative social consequences—intended emotive, benefits of quitting—informational, benefits of quitting—graphic) in one of the three contexts (alone, next to a cigarette ad, POS tobacco display). We assessed participants’ reactions to the ads, including perceived effectiveness, negative emotion, affective dissonance, and motivational reaction. Graphic ads elicited more negative emotion and affective dissonance than benefits of quitting ads. Graphic ads elicited higher perceived effectiveness and more affective dissonance than intended emotive ads. Antismoking ads fared best when viewed alone, and graphic ads were least influenced by the context in which they were viewed. These results suggest that in developing POS campaigns, it is important to consider the competitive pro-tobacco context in which antismoking ads will be viewed.  相似文献   
69.
While many with schizophrenia spectrum disorders experience difficulties understanding the feelings of others, little is known about the psychological antecedents of these deficits. To explore these issues we examined whether deficits in mental state decoding, mental state reasoning and metacognitive capacity predict performance on an emotion recognition task. Participants were 115 adults with a schizophrenia spectrum disorder and 58 adults with substance use disorders but no history of a diagnosis of psychosis who completed the Eyes and Hinting Test. Metacognitive capacity was assessed using the Metacognitive Assessment Scale Abbreviated and emotion recognition was assessed using the Bell Lysaker Emotion Recognition Test. Results revealed that the schizophrenia patients performed more poorly than controls on tests of emotion recognition, mental state decoding, mental state reasoning and metacognition. Lesser capacities for mental state decoding, mental state reasoning and metacognition were all uniquely related emotion recognition within the schizophrenia group even after controlling for neurocognition and symptoms in a stepwise multiple regression. Results suggest that deficits in emotion recognition in schizophrenia may partly result from a combination of impairments in the ability to judge the cognitive and affective states of others and difficulties forming complex representations of self and others.  相似文献   
70.
Time series analyses are statistical methods used to assess trends in repeated measurements taken at regular intervals and their associations with other trends or events, taking account of the temporal structure of such data. Addiction research often involves assessing associations between trends in target variables (e.g. population cigarette smoking prevalence) and predictor variables (e.g. average price of a cigarette), known as a multiple time series design, or interventions or events (e.g. introduction of an indoor smoking ban), known as an interrupted time series design. There are many analytical tools available, each with its own strengths and limitations. This paper provides addiction researchers with an overview of many of the methods available (GLM, GLMM, GLS, GAMM, ARIMA, ARIMAX, VAR, SVAR, VECM) and guidance on when and how they should be used, sample size det ermination, reporting and interpretation. The aim is to provide increased clarity for researchers proposing to undertake these analyses concerning what is likely to be acceptable for publication in journals such as Addiction. Given the large number of choices that need to be made when setting up time series models, the guidance emphasizes the importance of pre‐registering hypotheses and analysis plans before the analyses are undertaken.  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