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   358086篇
  免费   25574篇
  国内免费   7903篇
耳鼻咽喉   4207篇
儿科学   9773篇
妇产科学   6750篇
基础医学   28742篇
口腔科学   8466篇
临床医学   40572篇
内科学   43419篇
皮肤病学   4801篇
神经病学   20553篇
特种医学   8450篇
外国民族医学   38篇
外科学   37587篇
综合类   53635篇
现状与发展   12篇
一般理论   29篇
预防医学   39006篇
眼科学   5353篇
药学   33243篇
  447篇
中国医学   32073篇
肿瘤学   14407篇
  2023年   5763篇
  2022年   8525篇
  2021年   13589篇
  2020年   13457篇
  2019年   19029篇
  2018年   16703篇
  2017年   13677篇
  2016年   11295篇
  2015年   10567篇
  2014年   21461篇
  2013年   23176篇
  2012年   19742篇
  2011年   21285篇
  2010年   16970篇
  2009年   15618篇
  2008年   15167篇
  2007年   15628篇
  2006年   13646篇
  2005年   11732篇
  2004年   9607篇
  2003年   8441篇
  2002年   6593篇
  2001年   5933篇
  2000年   4897篇
  1999年   4222篇
  1998年   3256篇
  1997年   3062篇
  1996年   2649篇
  1995年   2732篇
  1994年   2625篇
  1993年   2086篇
  1992年   2125篇
  1991年   1828篇
  1990年   1636篇
  1989年   1443篇
  1988年   1371篇
  1987年   1168篇
  1985年   3855篇
  1984年   4846篇
  1983年   3364篇
  1982年   3835篇
  1981年   3578篇
  1980年   3201篇
  1979年   2929篇
  1978年   2554篇
  1977年   1926篇
  1976年   2163篇
  1975年   1644篇
  1974年   1436篇
  1973年   1283篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
BackgroundTo date, no previous studies have evaluated the relationship between sleep duration and quality of life (QOL) or depression in the general population after controlling for daytime sleepiness and sleep disturbances.MethodsA web-based cross-sectional survey was conducted with 8698 subjects aged 20–69 years. We examined the relationships between weekday sleep duration and daytime sleepiness, sleep disturbance, QOL and depression, using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (without the item for sleep duration), 8-item Short Form and Center for Epidemiological Studies Depression Scale (CES-D).ResultsDaytime sleepiness tended to increase in proportion to shorter weekday sleep durations. Sleep disturbances, physical and mental QOL, and CES-D scores were worse in both the shorter and longer sleep groups compared with the group with 7–8 h of sleep. Hierarchical logistic regression analyses revealed that short sleep duration but not long sleep duration was significantly associated with reduction of both physical and mental QOL, even after controlling for the presence of daytime sleepiness and sleep disturbance. Both short and long sleep duration were independently and significantly correlated with depression after controlling for daytime sleepiness; however, there was no statistically significant association after adjusting for the effects of sleep disturbance.ConclusionsThe results suggested adverse effects of short sleep but not long sleep on both physical and mental QOL. In addition, the negative impact of specific types of sleep disturbance on depression may be greater than the impact of shortening of sleep duration.  相似文献   
992.
IntroductionPrimary progressive apraxia of speech (PPAOS) is a neurodegenerative syndrome in which patients present with an isolated motor speech disorder. Some PPAOS patients develop parkinsonism and other features of progressive supranuclear palsy (PSP) and/or corticobasal syndrome (CBS) over time. We aimed to assess the evolution of parkinsonian characteristics in PPAOS patients who had been followed yearly for at least six years.MethodsFrom a large cohort of 46 PPAOS patients, eight were followed yearly for > 6-years in multiple NIH-funded grants. Parkinsonian and other features, including bradykinesia, tremor, rigidity, postural instability, apraxia, ocular motor function and cognition were assessed at each visit, and research criteria applied for PSP and CBS diagnosis. Neurological, speech-language test scores, and [18F]fluorodeoxyglucose PET (FDG-PET) and MRI midbrain volumes were assessed.ResultsA Parkinson's plus syndrome developed in all eight patients (100%). Bradykinesia was the earliest feature, followed by rigidity and postural instability. Tremor was not a significant feature. Parkinsonism, limb apraxia and ocular motor impairment tended to develop four-to-five years after onset with some patients having slight asymmetric parkinsonism. Six patients (75%) met research criteria for probable PSP, although only one for PSP-Richardson's syndrome; three patients met criteria for possible CBS. Slightly asymmetric, left-sided, hypometabolism was observed on FDG-PET, not matching asymmetry of Parkinsonism. Midbrain hypometabolism was absent-minimal. Three patients had progressive midbrain volumes in the PSP-Richardson's syndrome range.ConclusionsA Parkinson's plus syndrome may inevitably develop in PPAOS supporting PPAOS as an early presentation of a Parkinson's plus disorder.  相似文献   
993.
《Radiography》2020,26(4):e284-e289
IntroductionRadiographers employed in remote locations such as Far North Queensland (FNQ) can face unique sets of challenges as they often perform radiographic and sonographic diagnostic imaging without onsite radiologists' services. Additionally, the majority of patients presenting to these sites are Indigenous for whom English may be their third language. This non-participant observational study observed two FNQ radiographers' interactions with patients and interprofessional staff, and the radiographers' ability to fit into the Indigenous community during routine radiographic and sonographic examinations which to date have received little attention.MethodsNon-participant observations and semi-structured interviews with radiographers were held at two FNQ hospitals. Consecutive radiographer–patient interactions were observed and recorded on checklists. Interviews were audio recorded and transcribed for thematic analysis.ResultsAcross both remote sites, 24 patients were observed as they underwent diagnostic imaging examinations, with the majority being Aboriginal or Torres Strait Islanders (n = 17/24 (70.8%). In total, eleven general radiography and sixteen ultrasound examinations were observed. Semi-structured interviews highlighted complex issues such as the need for radiographer communication in local dialect, ongoing interprofessional collaborations, overcoming the lack of radiologists' onsite support by providing radiographic reports directly to referring doctors and midwives, and isolation with regard to professional development opportunities.ConclusionsRadiographers working in remote hospitals need to be culturally competent, navigate local indigenous languages and possess excellent interprofessional skills as well as thorough knowledge of imaging pathology to convey findings to referring doctors and allied health professionals. These findings have implications for the entry to practice curriculum.Implications for practiceThis study provides evidence that culturally competent radiographers are capable of undertaking reporting roles to facilitate patient management in the absence of timely radiologists' reports at remote sites.  相似文献   
994.
995.
BackgroundCommunity involvement is an important component of health programme development and implementation, including those focused on chronic condition treatment and management. Yet, few studies explore the manifestations of community involvement in chronic care programmes. Our review aims to examine the evidence on how communities are involved in planning and implementing chronic condition programmes in high and upper-middle income countries.MethodsEligible studies included those that involved the community in the planning, implementation, monitoring and evaluation of health services, policy or health interventions. We searched Medline, Embase, Global Health, Scopus, and LILACs from 2000 to 2016, independently screened articles for inclusion, conducted data extraction, and assessed studies for risk of bias.Results27,232 records were identified and after screening, 32 met inclusion criteria. We conducted a narrative synthesis to report on the forms and processes of community involvement used across mental health programmes and contrast this with the paucity of evidence on comparable programmes addressing other chronic conditions. Challenges reported included user factors, organisational factors, and social challenges such as stigma.ConclusionOur review adds to the evidence supporting community involvement in chronic condition management and the processes that contribute to successful and sustainable involvement. We report on a model, derived from inductive analysis, that considers social and cultural components, organisational factors and stakeholder relationships as underpinning the development of community interventions across the care continuum.  相似文献   
996.
ObjectiveTo evaluate the impact of the Plan for the promotion of personal autonomy and prevention of disability in Andalusia (2016-2020) in 13 public administrations during the first year of its implementation; and to analyse the usability and feasibility of the impact assessment ladder used.MethodThe Plan addresses the promotion of personal autonomy and the prevention of disabilities and dependencies through a multisectoral approach. It is structured in strands or lines of work, objectives and actions that have been assessed through the Adoption Impact Ladder (AIL). The analysis of the face validity, feasibility and inter-rater reliability of the impact assessment ladder was carried out in 30 actions of the Plan that were rated by 20 experts from the 13 ministries and public agencies involved in the Plan, and an external rater.Results176 actions and programmes were launched in 2017. Of these, 67.2% were implemented during the first year. Only one of the 16 objectives had no action initiated during the first year. Moreover, 7 out of 15 objectives implemented were fully multisectoral involving more than three Regional Ministries. The face validity, feasibility and inter-rater reliability of the AIL were good (κ: 0.72).ConclusionsThis Plan has provided a novel framework to coordinate a broad range of proposed policies and actions within the public administration of Andalusia. For the first time, a multisectoral impact analysis has been conducted providing an effective guide for monitoring, planning and setting public priorities in health, social services, ageing and disabilities.  相似文献   
997.
In recent years, there has been an increased focus on patient involvement in treatment planning in the health care system. To reduce the risk of the clinician moving towards paternalism, various methods have been introduced—shared decision making, among others. The goal of shared decision making is for the clinician and patient to share available evidence on the best treatment and to raise awareness on the needs and preferences of the patient as to make a genuinely informed choice. However, in the present article, we discuss to which degree paternalism can be avoided in light of the clinician's role as an authority with certain knowledge and expertise. Through the philosophical theory of reasons‐responsiveness, we discuss to which extend free will and control applies to the patient. Through theoretical analysis, we come to suggest that the clinician has a role as an ally rather than manipulator.  相似文献   
998.
IntroductionThe ability to direct and maintain attention is a prerequisite for learning. Qigong exercises are already commonly practiced in many developed countries to increase attention and memory. The main goal of this study was to examine whether Qigong would improve the attention levels of adolescents (12–14 years of age) when practiced as part of their physical education course.MethodThree groups of 22 individuals were considered: the verum group, which performed true Qigong; the control group, which performed sham, or placebo Qigong; and the waiting list group. In order to evaluate Qigong effects, attention tests (d2) were applied to all groups before the intervention period (t1) and after two and four weeks of practice (t2 and t3, respectively).ResultsAt t1, there was no significant difference between the verum, control and waiting list groups in all measurable features. After 4 weeks of exercise, the verum group was significantly superior in all measurable features in comparison to the control group and the waiting list group. Values in the waiting list group were generally worse than in the control group (placebo Qigong), but there was no significant difference between the control and waiting list group, showing that the placebo offered an effect that was not significantly greater than the effect of no intervention at all.Conclusion‘White Ball’ Qigong was able to improve attention in adolescents after 4 weeks of practice, leading us to conclude that it may be a useful tool when integrated into physical education classes.  相似文献   
999.
ObjectiveCurcuma longa has been widely used in Ayurveda for its medicinal properties and Turmacin was developed from C. longa as a standardized extract containing turmerosaccharides. In this clinical trial, the effect of Turmacin on knee joint discomfort in healthy adults subjected to strenuous physical activity was evaluated.DesignDouble-blind, triple-arm, parallel-group, randomized placebo-controlled trial.SettingHealthy participants from an urban tertiary care teaching hospital.InterventionHealthy participants were randomized in 1:1:1 ratio to receive either Turmacin 0.5 g/1 g or placebo once daily for 84 days. The participants were subjected to 10-minute strenuous exercise.Outcome measuresTime to initial pain, final pain score on a visual analogue scale, range of movement (ROM) of knee and the force of contractions of muscles around the knee joint.ResultsA total of n = 90 participants were recruited. The mean final pain scores were significantly lower in the Turmacin 1 g and Turmacin 0.5 g when compared with the placebo from day-7 and day-5 onwards respectively. The survival analysis consistently showed a decreased hazard for early onset of pain in both the Turmacin groups. On day-84, the difference in mean ROM between Turmacin 0.5 g and placebo was 4.79 degrees (p = 0.008) and that for Turmacin 1 g and placebo was 2.34 degrees (p = 0.306). The difference in muscle force for isokinetic contractions of the quadriceps at angular velocities of 120 and 180 was significant between Turmacin 0.5 g and placebo (p = 0.002 and p = 0.005 respectively) while that for Turmacin 1 g & Turmacin 0.5 g (p = 0.206 and p = 0.414 respectively) and Turmacin 1 g & Placebo (p = 0.046 and p = 0.037) were not significant. However, in the within group analysis participants in Turmacin 1 g group had better preserved muscle functions than Turmacin 0.5 g group at angular velocities of 120 and 180 when compared with placebo.ConclusionTurmacin (0.5 g and 1 g) was efficacious when compared to placebo in increasing the pain threshold and knee ROM in healthy participants with minor adverse events.  相似文献   
1000.
BackgroundFrequent patient handling activities present numerous challenges to healthcare workers. A variety of products are available to assist with in-bed positioning but few comparative studies have been completed to ascertain turning effectiveness.MethodsThe purpose of this study was to compare two turning devices (air-powered positioning system with wedges versus ceiling lift with pillows) for in-bed repositioning and turning effectiveness. The study took place at a large community hospital in the Midwestern USA and used a prospective, four-group crossover study design to compare devices.ResultsThe two turning groups were not significantly different for any of the demographic variables. The use of an air-powered positioning system with wedges achieved a greater degree of turn and maintained that turn after an hour better than the lift device with pillows. There were no hospital acquired pressure injuries in either group.ConclusionThe devices used demonstrated significant differences in turn angle achieved and ability to maintain the turn at one hour. Future studies need to further delineate the ideal method for turning and compare devices to identify best practice and equipment. An effective turning method would integrate ease of use with the ability to achieve an optimal degree of turn in order to prevent hospital acquired pressure injuries while also decreasing caregiver injuries.  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