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   8116篇
  免费   762篇
  国内免费   323篇
耳鼻咽喉   40篇
儿科学   59篇
妇产科学   21篇
基础医学   844篇
口腔科学   706篇
临床医学   893篇
内科学   610篇
皮肤病学   32篇
神经病学   381篇
特种医学   373篇
外国民族医学   1篇
外科学   599篇
综合类   739篇
现状与发展   1篇
预防医学   352篇
眼科学   180篇
药学   2689篇
  2篇
中国医学   549篇
肿瘤学   130篇
  2024年   10篇
  2023年   116篇
  2022年   173篇
  2021年   360篇
  2020年   315篇
  2019年   331篇
  2018年   315篇
  2017年   323篇
  2016年   322篇
  2015年   324篇
  2014年   464篇
  2013年   690篇
  2012年   401篇
  2011年   490篇
  2010年   380篇
  2009年   387篇
  2008年   364篇
  2007年   355篇
  2006年   337篇
  2005年   303篇
  2004年   273篇
  2003年   255篇
  2002年   195篇
  2001年   190篇
  2000年   168篇
  1999年   159篇
  1998年   136篇
  1997年   122篇
  1996年   106篇
  1995年   113篇
  1994年   81篇
  1993年   82篇
  1992年   93篇
  1991年   70篇
  1990年   60篇
  1989年   44篇
  1988年   59篇
  1987年   26篇
  1986年   32篇
  1985年   54篇
  1984年   22篇
  1983年   25篇
  1982年   16篇
  1981年   19篇
  1980年   11篇
  1979年   5篇
  1978年   7篇
  1977年   4篇
  1976年   6篇
  1973年   4篇
排序方式: 共有9201条查询结果,搜索用时 17 毫秒
1.
BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η2 = 0.114) and liftoff (p = 0.122, η2 = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η2 = 0.648) and liftoff (p < 0.001, η2 = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η2 = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion.  相似文献   
2.
3.
ObjectiveThe aim of this study was to determine whether there is a difference in postural control between nulligravida women and women who have given birth by vaginal or cesarean section.MethodsWomen who had only vaginal delivery in the previous 1–3 years were included in the vaginal delivery group (n = 27), those who had only cesarean delivery in the previous 1–3 years were included in the cesarean section group (n = 28), and those who had never given birth were included in the control group (n = 32). Evaluations were administered 6–8 days after the ovulation phase. Postural control of the participants was evaluated with the computerized dynamic posturography device.ResultsA total of 87 women with a mean age of 29.4 ± 4 years and a mean body mass index of 24.1 ± 3.1 kg/m2 were included in the study. Antero-posterior somatosensory organization test values of the vaginal delivery group were lower than the control group (p = 0.0016). The cesarean delivery group had statistically lower antero-posterior somatosensory (p < 0.001 and p = 0.0013) and medio-lateral somatosensory (p = 0.002 and p = 0.017, respectively) test scores compared to the control group and the vaginal delivery group.ConclusionsIt was observed that women who birthed with vaginal or cesarean delivery had impaired somatosensory postural control. There is definitely a need for further studies with a long-term follow-up examining the effects of postural control during pregnancy and the postpartum period.  相似文献   
4.
BackgroundPassive and hybrid passive ankle foot orthoses (AFOs) are often prescribed in post stroke drop foot; however, the effects of these AFOs on balance related parameters in these patients seem unclear. Accordingly, the aim of current study was to evaluate the role of the newly designed hybrid passive and Posterior Leaf Spring (PLS) AFOs on balance related parameters including: self-reported balance confidence (ABC), Timed Up and Go Test (TUG) and Berg Balance Scale (BBS) in post stroke drop foot patients.MethodsFifteen post stroke drop foot patients were recruited in current study. Then, ABC, TUG and BBS were assessed with newly designed AFO and PLS AFO.ResultsThe results of this study were shown a significant improvement in ABC, TUG and BBS scores with the newly designed AFO than PLS AFO (p < 0.05).ConclusionThis study suggested that the newly designed AFO was improved the balance related parameters than PLS AFO.  相似文献   
5.
6.
ContextLateral ankle sprains (LAS) are among the most common injuries in sports, with a poor long – term prognosis due to high chronicity and recurrence rates. Chronic ankle instability (CAI) results up to 40% of people that endured a first – time LAS.ObjectiveThe aim of this study was to compare ankle stability between groups characterised by the use of different types of footwear during their sport activities.DesignCross-sectional study.SettingFirm training surface, local sport clubs.ParticipantsFifty - one male subjects were recruited, distributed in four groups based on the type of footwear they use during their sport activities.Main outcome measuresAll subjects performed four clinical ankle stability tests, and completed the Dutch version of the Cumberland Ankle Instability Tool (CAIT) and Profile of Mood States (POMS). All clinical ankle stability tests were performed barefoot.ResultsSubjects performing their sport activities barefoot scored better than subjects performing their sport with shoes at the multiple hop test (p = .002 to .047) and executed the figure–of–8 hop test significantly faster than subjects with submalleolar ankle support (AS) (p = .019). Subjects with submalleolar AS and studs showed significantly better results than subjects with supramalleolar AS on the CAIT– score (p = .024, p = .030) and the side– hop test (p = .050, p = .045). They also scored significantly better than subjects with submalleolar AS for the side – hop test (p = .032), foot – lift test (p = .019) and figure–of 8 hop test (p = .011).ConclusionBarefoot sports performing subjects appear to have better ankle stability compared to subjects performing their sports with shoe support. Subjects performing sports with high AS appear to have worst ankle stability.Level of evidence: Level III, Cross–sectional study.  相似文献   
7.
Sexual compatibility increases the stability of marriage and partners’ relationships and decreases sexually transmitted diseases. This qualitative study using a content analysis approach was conducted with 36 married men and women. Interviews were conducted for data collection. As the main theme of this study, “couple's sexual companionship” emerged as the main theme of sexual compatibility, that means couples’ participation for fulfilling each other sexual needs and solving problems arising from sexual discrepancies based on sexual understandings, sexual agreements and interests for continuing the sexual relationship with the aim of mutual sexual satisfaction. Sexual compatibility did not necessarily mean similarities, as during the marital life sexual discrepancies were inevitable. However, compatible couples encountered such a situation based on understandings, agreement and love. Active participation in sexual relationships, forgiveness and consideration, no huffing, mutual respect, flexibility and an occasional use of non-penetrative sexual relationships, sexual conversation with spouses, patience and development of the sexual relationship were the prominent feature of sexually compatible couples.  相似文献   
8.
Introduction: Phages consist of nucleic acids and proteins that may lose their activity under different physico-chemical conditions. The production process of phage formulations may decrease phage infectivity. Ingredients present in the preparation may influence phage particles, although preparation and storage conditions may also cause variations in phage titer. Significant factors are the manner of phage application, the patient’s immune system status, the type of medication being taken, and diet.

Areas covered: We discuss factors determining phage activity and stability, which is relevant for the preparation and application of phage formulations with the highest therapeutic efficacy. Our article should be helpful for more insightful implementation of clinical trials, which could pave the way for successful phage therapy.

Expert opinion: The number of naturally occurring phages is practically unlimited and phages vary in their susceptibility to external factors. Modern methods offer engineering techniques which should lead to enhanced precision in phage delivery and anti-bacterial activity. Recent data suggesting that phages may also be used in treating nonbacterial infections as well as anti-inflammatory and immunomodulatory agents add further weight to such studies. It may be anticipated that different phage activities could have varying susceptibility to factors determining their actions.  相似文献   

9.
Background: We developed a surgical knee rest (SKR) that can be used to decrease the stress placed on the lower half of the body when surgeons work in the standing position. We tested the effectiveness of this device in the context of laparoscopic surgery.

Material and methods: Five healthy, right-handed male surgeons participated, and we recorded surface electromyography (sEMG) signals from the two heads of the left and right gastrocnemius (Gc) muscles during laparoscopic resections of colorectal cancer. The outcome variable was the percentage of maximum Gc muscle effort generated, reported as percent maximal isometric voluntary contraction (%MVC), and this variable was compared between surgeries performed with and without use of the SKR. Assessment covered the first 100?min of surgery, subdivided into two 50-min periods.

Results: Mean %MVC of the left Gc muscle for the full 100-min test period was significantly decreased when the SKR was used (p?=?.027, vs. SKR not used). Notably, mean %MVC of both Gc muscles was significantly decreased during the first 50?min of surgery (p?=?.008 and p?=?.0046).

Conclusion: The SKR is useful for decreasing physical stress incurred by laparoscopic surgeons when working in the standing position.  相似文献   

10.
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