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   134395篇
  免费   7713篇
  国内免费   104篇
耳鼻咽喉   1623篇
儿科学   5134篇
妇产科学   3932篇
基础医学   16230篇
口腔科学   3129篇
临床医学   16288篇
内科学   24163篇
皮肤病学   1652篇
神经病学   12671篇
特种医学   6402篇
外科学   21777篇
综合类   671篇
一般理论   55篇
预防医学   11815篇
眼科学   2153篇
药学   6108篇
  1篇
中国医学   62篇
肿瘤学   8346篇
  2023年   3764篇
  2022年   5574篇
  2021年   5913篇
  2020年   6256篇
  2019年   4227篇
  2018年   4267篇
  2017年   4104篇
  2016年   4059篇
  2015年   4086篇
  2014年   7299篇
  2013年   6672篇
  2012年   5218篇
  2011年   5109篇
  2010年   5182篇
  2009年   4917篇
  2008年   4444篇
  2007年   4626篇
  2006年   4434篇
  2005年   4124篇
  2004年   3757篇
  2003年   3874篇
  2002年   3577篇
  2001年   3471篇
  2000年   3404篇
  1999年   3339篇
  1998年   1415篇
  1997年   1204篇
  1996年   1207篇
  1995年   1129篇
  1994年   945篇
  1993年   799篇
  1992年   2489篇
  1991年   2289篇
  1990年   2248篇
  1989年   2156篇
  1988年   1957篇
  1987年   908篇
  1985年   599篇
  1984年   586篇
  1983年   533篇
  1982年   585篇
  1981年   538篇
  1980年   531篇
  1979年   497篇
  1978年   473篇
  1977年   380篇
  1976年   377篇
  1975年   325篇
  1974年   396篇
  1973年   321篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
BackgroundUsing a mobile phone while performing a postural and locomotor tasks is a common, daily situation. Conversing or sending messages (SMS) while walking account for a significant share of accidental injuries. Therefore, understanding the consequences of using a mobile phone on balance and walking is important, all the more so when these postural and locomotor tasks are aggravated by a disease.Research questionOur objective was to conduct a scoping review on the influence of a dual-task situation – generated by the use of mobile phone – on users' postural and/or locomotor tasks.MethodsThe literature search was conducted in English on PubMed/Medline and CINHAL databases, using keywords associated with postural and locomotor tasks and with the use of mobile phone. Study location, population, number of subjects, experimental design, types of phone use, evaluated postural-locomotor tasks and expected effects were then analyzed.Results and significance46 studies were included in this work, 24 of which came from North America. All studies compared postural and locomotor tasks with and without the use of a smartphone. Ten studies also compared at least 2 groups with different characteristics. Only 4 studies included pathological subjects. Various modalities were tested, and most studies focused on walking. Results show that the use of smartphones slows down movement and induces a systematic imbalance, except when listening to music. The dual task of "using the smartphone during a postural or locomotor tasks" induces systematic disturbances of balance and movement, which must be taken into account in the rehabilitation approach. Future studies will have to extend the knowledge regarding pathological situations.  相似文献   
83.
Introduction: Pharmacovigilance is essential to monitoring the safety profiles of authorized medicines. Compared with small-molecule drugs, biological drugs are more complex, more susceptible to structural variability due to manufacturing processes, and have the potential to induce immune-related reactions, underscoring the importance of safety monitoring for these products. Although highly similar to reference products, biosimilars are not expected to be structurally identical. For these reasons, proper reporting of potential adverse drug reactions (ADRs) using distinguishable names and batch numbers is essential for accurate tracing of all biological drugs. To address the need for robust pharmacovigilance, the European Parliament and Council of the European Union provided legislation regarding pharmacovigilance of biologics in 2010.

Areas covered: This narrative review examines the current state of pharmacovigilance for biologics in the European Union (EU) and discusses relevant information on pharmacovigilance of biosimilars, the current EU pharmacovigilance system, and areas that could be improved.

Expert opinion: Although steps have been taken to improve pharmacovigilance of biologics in the EU, several enhancements can still be made, including additional training for healthcare professionals on ADR reporting, the use of 2D barcodes that enhance traceability, and an open discussion of potentially missed opportunities in the pharmacovigilance of biosimilars.  相似文献   

84.
IntroductionWith the increasing reliance on targeted therapies and immunotherapy, no standard management strategy is today available for the treatment of locally, distant, or both renal cell carcinoma (RCC) recurrences, and their surgical treatment seems to play a crucial role. We report the 20-year experience of our center evaluating the short- and long-term outcomes of patients undergone surgical resection of RCC recurrences, and the possible role of repeated surgical resections of RCC recurrences.Materials and methodsFrom January 1999 to January 2019, 40 patients underwent surgical resection of isolated locally recurrent RCC (iLR-RCC-group), locally recurrent RCC associated with the presence of distant recurrence (LR-DR-RCC-group), and distant-only recurrent RCC (DR-RCC-group). Data regarding pre-, intra-, post-operative course, and follow-up, prospectively collected in an institutional database, were retrospectively analyzed and compared.ResultsiLR-RCC-group was composed of 9 patients, LR-DR-RCC-group of 6 patients, and DR-RCC-group of 25 patients. The recurrence rate was 55.6% (5/9 patients) in iLR-RCC-group, 50% (3/6 patients) in LR-DR-RCC-group, and 44% (11/25) patients in DR-RCC-group, p = 0.830. 3/5 (60%) patients in iLR-RCC-group, 2/3 (66.7%) patients in LR-DR-RCC-group, and 7/11 (63.6%) patients in DR-RCC group underwent to almost one further local treatments of their recurrences, respectively (p = 0.981). No differences in the mean disease-free survival (p = 0.384), overall survival (OS) (p = 0.881), and cancer-specific survival (p = 0.265) were reported between the three groups. In DR-RCC-group, patients who underwent further local treatments of new recurrences presented a longer OS: 150.7 versus 66.5 months (p = 0.004).ConclusionsA surgical resection of RCC recurrences should be always taken in consideration, also in metastatic patients and/or in those who have already undergone surgery of previous RCC recurrence, whenever radicality is still possible, because this approach may offer a potentially long survival.  相似文献   
85.
86.
87.
88.
89.
Limited reconstructive options exist for soft tissue defects of the foot and ankle because of a lack of surrounding tissue. Although microsurgical free flaps have become a popular treatment modality for this anatomic region, pedicled muscle flaps can provide robust coverage of small foot wounds with significantly less donor site comorbidity. One such muscle is the abductor hallucis, which can be used as a proximally based turnover flap to cover medial hindfoot defects. However, complete distal disinsertion of the muscle may lead to loss of support over the medial arch and first metatarsophalangeal joint, leading to pes planus and hallux valgus. In this case report, we describe a modified technique of a split abductor hallucis turnover flap for a young patient with a chronic, traumatic medial heel wound complicated by calcaneal osteomyelitis. By preserving part of the muscle's distal tendinous attachment, this technique allows for adequate soft tissue coverage while maintaining long-term biomechanical function.  相似文献   
90.
BackgroundA majority of youth with Autism Spectrum Disorder (ASD) have disrupted sleep patterns, but there has been limited research examining factors associated with sleep in this population. Objective: The objective of this study was to compare demographic and lifestyle behaviors with sleep quality in youth with ASD. Methods: A total of 49 children (12.44 years; 78% male) with ASD wore the Actigraph GT9X accelerometer over seven days and nights to assess moderate to vigorous physical activity (MVPA), sedentary behavior (SB), total sleep duration, and sleep efficiency. Parents reported their child’s weekly amount of screen time and demographic information. Participants were classified according to whether they met sleep criteria for duration and efficiency (8–9 h of sleep duration and ≥85% sleep efficiency). T-tests and ANOVA were used to compare demographic and lifestyle factors between the groups. Results: Participants who meet both sleep duration and efficiency criteria had greater minutes of MVPA per day (113.65 min/day) than participants who only met sleep efficiency criteria (40.27 min/day) and participants who did not meet either sleep criteria (67.5 min/day; p < 0.0001). Additionally, participants who met both sleep criteria had fewer minutes of SB compared to those who only met sleep efficiency criteria (384.79 vs 526.05 min/day; p = 0.02). Conclusions: Youth who had indicators of good sleep quality had greater amounts of MVPA and lower amounts of SB. Studies should further examine the relationship between sleep and health behaviors in youth with ASD to determine causal mechanisms, leading to more effective sleep interventions.  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