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   17264篇
  免费   1441篇
  国内免费   33篇
耳鼻咽喉   245篇
儿科学   602篇
妇产科学   675篇
基础医学   2560篇
口腔科学   293篇
临床医学   1868篇
内科学   3062篇
皮肤病学   276篇
神经病学   1890篇
特种医学   515篇
外国民族医学   55篇
外科学   1477篇
综合类   308篇
一般理论   24篇
预防医学   1939篇
眼科学   362篇
药学   1444篇
中国医学   28篇
肿瘤学   1115篇
  2023年   111篇
  2022年   209篇
  2021年   598篇
  2020年   325篇
  2019年   416篇
  2018年   459篇
  2017年   374篇
  2016年   438篇
  2015年   389篇
  2014年   559篇
  2013年   801篇
  2012年   1200篇
  2011年   1258篇
  2010年   641篇
  2009年   559篇
  2008年   962篇
  2007年   983篇
  2006年   945篇
  2005年   865篇
  2004年   861篇
  2003年   739篇
  2002年   679篇
  2001年   312篇
  2000年   299篇
  1999年   272篇
  1998年   156篇
  1997年   107篇
  1996年   109篇
  1995年   130篇
  1994年   124篇
  1993年   101篇
  1992年   203篇
  1991年   172篇
  1990年   198篇
  1989年   189篇
  1988年   174篇
  1987年   151篇
  1986年   131篇
  1985年   116篇
  1984年   120篇
  1983年   87篇
  1982年   70篇
  1981年   66篇
  1980年   70篇
  1979年   121篇
  1978年   93篇
  1977年   66篇
  1976年   72篇
  1974年   86篇
  1972年   69篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy.  相似文献   
2.
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.  相似文献   
3.
Abstract

Background: Cerebral palsy (CP) is a common childhood disability. However, these individuals are now living longer lives, participating in adult roles, and seeking healthcare services. The transition from pediatric to adult healthcare for adolescents with CP is a challenging yet significant time. Adolescents experience several barriers during transition.

Objectives: To utilize the environmental and personal dimensions of the ICF model in order to explore barriers when transitioning to adulthood as well as discuss characteristics and physical therapy implications needed to succeed within transition.

Methods: Electronic searching of PubMed, CINAHL, ERIC, Scopus, ProQuest, and the Cochrane Library databases was concluded on January 9, 2019 for studies including transition between pediatric and adult healthcare in individuals diagnosed with CP. Two independent reviewers agreed upon inclusion, eligibility, and quality assessment of each study using the Mixed-Methods Appraisal Tool (MMAT).

Results: Seven studies were included in the systematic review. Results for each study were separated based on the personal and environmental contextual factors of the ICF model and solutions to the barriers were then discussed.

Conclusions: Research has provided proposed solutions to select barriers, however, other barriers have yet to be addressed. More research is needed to address these barriers and provide a model program that can be implemented within the healthcare systems to promote a successful transition for adolescents with CP from pediatric to adult services.  相似文献   
4.
BackgroundThe aim of this paper is to assess the current state of quality and outcomes measures being reported for hepatic resections in the recent literature.MethodsMedline and PubMed databases were searched for English language articles published between 1 January 2002 and 30 April 2013. Two examiners reviewed each article and relevant citations for appropriateness of inclusion, which excluded papers of liver donor hepatic resections, repeat hepatectomies or meta-analyses. Data were extracted and summarized by two examiners for analysis.ResultsFifty-five studies were identified with suitable reporting to assess peri-operative mortality in hepatic resections. In only 35% (19/55) of the studies was the follow-up time explicitly stated, and in 47% (26/55) of studies peri-operative mortality was limited to in-hospital or 30 days. The time period in which complications were captured was not explicitly stated in 19 out of 28 studies. The remaining studies only captured complications within 30 days of the index operation (8/28). There was a paucity of quality literature addressing truly patient-centred outcomes.ConclusionQuality outcomes after a hepatic resection are inconsistently reported in the literature. Quality outcome studies for a hepatectomy should report mortality and morbidity at a minimum of 90 days after surgery.  相似文献   
5.
6.
7.

Background

Total knee arthroplasty is a treatment option for debilitating arthritis. In the postoperative period, patients experience moderate to severe pain affecting the rehabilitation, hospital stay, and patient satisfaction. This study aims at utilizing current best evidence to determine whether adductor canal block (ACB) or periarticular injection (PAI) is a better modality for managing short-term postoperative pain and opioid consumption.

Methods

Embase, MEDLINE, HealthStar, Emcare, and PubMed were searched for randomized controlled trials from 1946 to August 2018, for literature addressing the comparison of ACB and PAI for pain management in the setting of total knee arthroplasty. A systematic review and meta-analysis were performed.

Results

Six studies were included in our meta-analysis. When examining the combined visual analog scale (VAS) pain values for each group, analysis demonstrated greater reduction in scores for the PAI group, and the difference was statistically significant (P = .001). When comparing the VAS scores of subgroups analyzed at specific periods in time, there was a trend toward lower VAS scores in subgroups analyzed at 24 hours and 48 hours postoperatively (at rest and at movement) in the PAI group. Overall opioid consumption was lower in the PAI group, with demonstrated statistical significance (P = .03). When comparing the postoperative subgroups, there was a trend toward decreased opioid use in the PAI group, with 13.25% less opioid use at 48 hours and 9.5% less opioid use at 24 hours.

Conclusion

PAI could significantly improve postoperative pain and opioid consumption when compared with ACB. Additional, high-quality studies are required to further address this topic.  相似文献   
8.
9.
Paediatric palliative care and neurodisability are two relatively new, evolving paediatric sub-specialities that have increasing relevance in the current paediatric landscape. For many people palliative care has been synonymous with end of life care, but in paediatrics it encompasses much more and is for all children with life-threatening or life-limiting conditions, from the point of diagnosis. This breadth of focus is demonstrated well through the interface between paediatric palliative care and paediatric neurodisability. In this article we explore this unique interface through the three domains of complex symptom management, advanced care planning and end of life care. We describe the practicalities involved in all three areas and highlight the importance of early referral and the process of “dual” or “parallel” planning. We cover in more depth the specific management of the symptoms: dystonia/abnormalities of muscle tone, seizures, pain, agitation, secretions, respiratory failure, and gut failure.  相似文献   
10.
Understanding the contribution of endothelial cells to the progenitor pools of adult tissues has the potential to inform therapies for human disease.To address whether endothelial cells transdifferentiate into non-vascular cell types,we performed cell lineage tracing analysis using transgenic mice engineered to express a fluorescent marker following activation by tamoxifen in vascular endothelial cadherin promoter-expressing cells(VEcad-CreERT2;B6 Cg-Gt(ROSA)26Sortm9(CAG-tdTomato)Hze).Activation of target-cell labeling following 1.5 months of ad libitum feeding with tamoxifen-laden chow in 4–5 month-old mice resulted in the tracing of central nervous system and peripheral cells that include:cerebellar granule neurons,ependymal cells,skeletal myocytes,pancreatic beta cells,pancreatic acinar cells,tubular cells in the renal cortex,duodenal crypt cells,ileal crypt cells,and hair follicle stem cells.As Nestin expression has been reported in a subset of endothelial cells,Nes-CreERT2 mice were also utilized in these conditions.The tracing of cells in adult Nes-CreERT2 mice revealed the labeling of canonical progeny cell types such as hippocampal and olfactory granule neurons as well as ependymal cells.Interestingly,Nestin tracing also labeled skeletal myocytes,ileal crypt cells,and sparsely marked cerebellar granule neurons.Our findings provide support for endothelial cells as active contributors to adult tissue progenitor pools.This information could be of particular significance for the intravenous delivery of therapeutics to downstream endothelial-derived cellular targets.The animal experiments were approved by the Boise State University Institute Animal Care and Use Committee(approval No.006-AC15-018)on October 31,2018.  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