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   4539篇
  免费   293篇
  国内免费   162篇
耳鼻咽喉   45篇
儿科学   57篇
妇产科学   49篇
基础医学   796篇
口腔科学   198篇
临床医学   395篇
内科学   451篇
皮肤病学   76篇
神经病学   437篇
特种医学   90篇
外国民族医学   2篇
外科学   298篇
综合类   904篇
预防医学   329篇
眼科学   161篇
药学   351篇
  2篇
中国医学   96篇
肿瘤学   257篇
  2023年   48篇
  2022年   113篇
  2021年   136篇
  2020年   185篇
  2019年   116篇
  2018年   123篇
  2017年   136篇
  2016年   139篇
  2015年   118篇
  2014年   280篇
  2013年   289篇
  2012年   250篇
  2011年   256篇
  2010年   231篇
  2009年   174篇
  2008年   189篇
  2007年   181篇
  2006年   177篇
  2005年   159篇
  2004年   145篇
  2003年   149篇
  2002年   118篇
  2001年   118篇
  2000年   77篇
  1999年   65篇
  1998年   55篇
  1997年   66篇
  1996年   66篇
  1995年   86篇
  1994年   68篇
  1993年   70篇
  1992年   67篇
  1991年   57篇
  1990年   47篇
  1989年   53篇
  1988年   56篇
  1987年   45篇
  1986年   39篇
  1985年   52篇
  1984年   29篇
  1983年   29篇
  1982年   23篇
  1981年   27篇
  1980年   20篇
  1979年   14篇
  1978年   15篇
  1977年   11篇
  1976年   9篇
  1975年   7篇
  1974年   5篇
排序方式: 共有4994条查询结果,搜索用时 15 毫秒
1.
2.
【目的】 了解学术期刊专题/专栏建设的现状,以切实发挥学术期刊专题/专栏建设的作用,为期刊的品牌建设、学术创新、影响力提升和办刊质量提高提供策略。【方法】 采用问卷调查法,对全国范围内397名专题/专栏合作对象(包括期刊主编、编委、审稿人、作者)进行调查,了解他们对期刊专题/专栏建设的态度和意见,从合作对象视角探讨影响学术期刊专题/专栏建设成功率和有效性的因素。【结果】 合作对象态度上,表示支持专题/专栏建设工作的比例较高(71.28%),但供稿率不高(43.37%),存在态度和行为分离的现象。排名前5的供稿率影响因素是期刊被本专业领域研究者认可、期刊被数据库收录情况、期刊影响力、期刊品牌、期刊的处理速度。最优的约稿方式是行业内的学术带头人联系约稿,其次是熟识的专家委托和期刊主编亲自联系进行约稿。合作对象最希望获得的帮助是稿件快速审理发表和确定选题方向。【结论】 为提高学术期刊专题/专栏建设质量,应进一步挖掘重要合作对象的作用,有针对性地选择高供稿率的合作对象;努力挖掘和利用影响合作对象供稿的因素,在期刊品牌建设、扩大影响力方面下功夫;优化约稿方式方法,重视行业学术带头人的作用;同时通过稿件快速审理发表、帮助确定选题并提供发表后推广等服务,提高合作对象对专题/专栏建设工作的认可度和参与度。  相似文献   
3.
4.
BackgroundIn the United States nearly 20% of children ages 12–17 have developmental disorders. Some attain population-based developmental milestones after a delay, or increase functioning through special education, medication, technology, or therapy. Others have severe lasting impairments. An indicator identifying those groups in surveys of adults could help shape policies to improve lives.HypothesesWe hypothesized that survey histories of special education could indicate functional status levels.MethodsData were from the nationally representative Panel Study of Income Dynamics (1997–2017, n = 2745). With measures of diagnoses, behaviors, functional status, service use, and adult outcomes, we tested three special education groups as indicators of: (1) no impairment (no special education), (2) disorders, developmental diagnoses that adversely affect educational performance, but with development after a period of delay or only moderate disability, indicated by transfer from special education; and (3) severe lasting disability, the diagnoses combined with life-long needs for supports or services, with limitations in areas including self-care, mobility, and capacity for independent living, indicated by special education in the individual's final year of school.ResultsAcross the special education groups, from no impairment to severe lasting disability, there were trends of: increasing severe and lasting disability (respectively 4.8%, 35.6%, 76.4%); increasing special services use (13.5%, 43.1%, 83.7%); increasing severe emotional disorders (2.3%, 11.3%, 17.9%); lower percentages attaining at least an associate's degree by age 25 (42.1%, 20.7%, and 8.9%); and more chronic diseases.ConclusionsSpecial education histories provide a useful indicator of developmental disability impairment levels in adults.  相似文献   
5.
6.
《Vaccine》2022,40(6):934-944
Respiratory Syncytial Virus (RSV) remains a leading cause of severe respiratory disease for which no licensed vaccine is available. We have previously described the derivation of an RSV Fusion protein (F) stabilized in its prefusion conformation (preF) as vaccine immunogen and demonstrated superior immunogenicity in naive mice of preF versus wild type RSV F protein, both as protein and when expressed from an Ad26 vaccine vector. Here we address the question if there are qualitative differences between the two vaccine platforms for induction of protective immunity. In naïve mice, both Ad26.RSV.preF and preF protein induced humoral responses, whereas cellular responses were only elicited by Ad26.RSV.preF. In RSV pre-exposed mice, a single dose of either vaccine induced cellular responses and strong humoral responses. Ad26-induced RSV-specific cellular immune responses were detected systemically and locally in the lungs. Both vaccines showed protective efficacy in the cotton rat model, but Ad26.RSV.preF conferred protection at lower virus neutralizing titers in comparison to RSV preF protein. Factors that may contribute to the protective capacity of Ad26.RSV.preF elicited immunity are the induced IgG2a antibodies that are able to engage Fcγ receptors mediating Antibody Dependent Cellular Cytotoxicity (ADCC), and the induction of systemic and lung resident RSV specific CD8 + T cells. These data demonstrate qualitative improvement of immune responses elicited by an adenoviral vector based vaccine encoding the RSV preF antigen compared to the subunit vaccine in small animal models which may inform RSV vaccine development.  相似文献   
7.
Titin, encoded by the gene TTN, is one of the main sarcomere components. It is involved in not only maintaining the structure of cardiac and skeletal muscles, but also in their development, extensibility, elasticity, and signaling events. Congenital titinopathy increasingly appears an important and common form of axial predominant congenital myopathy. The pathophysiological role of TTN in congenital titinopathy and pediatric heart diseases is yet to be explored. Here, we delineate the phenotype of two female siblings who developed severe congenital multi-minicore disease without cardiac involvement. Genetic investigation by whole exome sequencing demonstrated compound heterozygous TTN mutations (c.15496+1G>A, p.5166_5258del; c.18597_18598insC, p.Thr6200Hisfs*15), corresponding to the Ig domain of the proximal I-band. Aberrant splicing causing exon skipping was verified by in vitro minigene analysis. Our results suggest that TTN mutations affecting the Ig domain of the proximal I-band may be a cause of severe congenital defect in skeletal muscles without severe cardiac involvement, thereby providing evidence for the hypothesis that congenital titinopathy patients carrying biallelic N2BA only mutations are at lower cardiac risk than those with other combinations of mutations. Meanwhile, this study confirm the hypothesis on recessive truncating variants of TTN experimentally and thus support earlier reported genotype-phenotype correlations.  相似文献   
8.
BackgroundWe hypothesized that patients undergoing primary total knee arthroplasty (TKA) for rheumatoid arthritis (RA) would have different preoperative expectations compared to osteoarthritis (OA) patients, and that postoperative satisfaction would correlate with specific postoperative pain and functional domains.MethodsThis is a retrospective cohort study of RA patients matched based on age, gender, American Society of Anesthesiologists score, and Charlson Comorbidity Index score 1:2 with OA patients (76 RA, 152 OA) who underwent primary TKA. The Hospital for Special Surgery Knee Replacement Expectations Survey, Visual Analogue Scale for Pain (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS), and the Short Form-12 (SF-12) were compared at baseline and at 2 years postoperatively. Minimum clinically important differences (MCIDs) were calculated for KOOS and SF-12 subdomains.ResultsPreoperatively, RA patients had lower expectations, worse VAS Pain, and worse KOOS Pain, Symptoms, and Activities of Daily Living (P < .05). However, at 2 years, RA patients had significantly larger improvements in VAS (P = .01) and these 3 KOOS subdomains (P < .05), achieving comparable absolute scores to OA patients. Overall, 86.1% of RA and 87.1% of OA patients were either somewhat or very satisfied with their TKA. Patient satisfaction correlated with VAS Pain and KOOS outcome scores in both groups. RA and OA patients had high rates of achieving MCID in SF-12 physical component scores and all 5 KOOS subdomains. A higher proportion of RA patients achieved MCID in KOOS Symptoms (98.4% vs 77.2%, P < .001).ConclusionRA patients had lower baseline expectations compared to OA patients. However, RA patients had greater improvements in KOOS and SF-12 subdomains, and there was no difference in satisfaction compared to OA patients after TKA.  相似文献   
9.
10.
Invasive fungal infections constitute an important cause of morbidity and mortality in solid organ transplantation recipients. Since solid organ transplantation is an effective therapy for many patients with end-stage organ failure, prevention and treatment of fungal infections are of vital importance. Diagnosis and management of these infections, however, remain difficult due to the variety of clinical symptoms in addition to the lack of accurate diagnostic methods. The use of fungal biomarkers can lead to an increased diagnostic accuracy, resulting in improved clinical outcomes. The evidence for optimal prophylactic approaches remains inconclusive, which results in considerable variation in the administration of prophylaxis. The implementation of a standard protocol for prophylaxis remains difficult as previous treatment regimens, which can alter the distribution of different pathogens, affect the outcome of antifungal susceptibility testing. Furthermore, the increasing use of antifungals also contributes to incremental costs and the risk of development of drug resistance. This review will highlight risk factors, clinical manifestations and timing of fungal infections and will focus predominately on the current evidence for diagnosis and management of fungal infections.  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