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   31935篇
  免费   1575篇
  国内免费   708篇
耳鼻咽喉   388篇
儿科学   649篇
妇产科学   1130篇
基础医学   8316篇
口腔科学   711篇
临床医学   2299篇
内科学   3067篇
皮肤病学   513篇
神经病学   1944篇
特种医学   942篇
外科学   1705篇
综合类   3125篇
预防医学   3621篇
眼科学   343篇
药学   3279篇
  3篇
中国医学   388篇
肿瘤学   1795篇
  2023年   283篇
  2022年   627篇
  2021年   830篇
  2020年   796篇
  2019年   788篇
  2018年   790篇
  2017年   886篇
  2016年   854篇
  2015年   937篇
  2014年   1807篇
  2013年   1878篇
  2012年   1610篇
  2011年   1953篇
  2010年   1502篇
  2009年   1574篇
  2008年   1640篇
  2007年   1517篇
  2006年   1348篇
  2005年   1141篇
  2004年   1016篇
  2003年   934篇
  2002年   674篇
  2001年   677篇
  2000年   638篇
  1999年   586篇
  1998年   577篇
  1997年   538篇
  1996年   557篇
  1995年   569篇
  1994年   540篇
  1993年   443篇
  1992年   436篇
  1991年   368篇
  1990年   327篇
  1989年   293篇
  1988年   262篇
  1987年   217篇
  1986年   176篇
  1985年   260篇
  1984年   249篇
  1983年   149篇
  1982年   144篇
  1981年   137篇
  1980年   121篇
  1979年   109篇
  1978年   83篇
  1977年   73篇
  1976年   57篇
  1974年   42篇
  1973年   38篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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   
2.
3.
目的:了解2011-2017年四川省三州地区卫生人力资源配置现状,为三州地区卫生人力资源的合理配置提供参考。方法:利用千人卫生人力资源拥有量指标、基尼系数和卫生人力资源密度指数(HRDI)分析卫生人力资源配置现状及其公平性。结果:三州地区千人卫生人力资源拥有量呈增长趋势;基尼系数大多超过0.4,仅护士按人口分布的基尼系数较小;卫生人力资源密度指数较小,需要量、缺乏量及缺乏比例均较大。结论:三州地区卫生人力得到一定程度改善;但配置公平性较差,尤其按地理、经济分布很不均衡;医护人员短缺,需要重点投入。  相似文献   
4.
内脏利什曼病是全球被忽视的传染病之一,危害严重。而利什曼原虫-人类免疫缺陷病毒(human immunodeficiency virus,HIV)合并感染对流行地区造成的威胁更甚。利什曼原虫与HIV存在相互作用,合并感染者在临床表现、诊断及治疗方面具有一定特殊性,其病死率及复发率均高于HIV阴性的内脏利什曼病患者。本文对利什曼原虫-HIV合并感染患者的临床表现、诊断和治疗进展进行综述。  相似文献   
5.
BackgroundPreschool age is a critical stage of postural balance development. Posturography normative data during this age are crucial for surveillance of postural balance and for the timely diagnosis of any dysfunction. The aim of this study was to provide normative data, specific to Tunisian preschoolers, according to age and gender, and to examine gender- and age-related differences in postural balance.Research questionAre there postural balance gender- and age-related differences in Tunisian preschoolers?MethodsThe study included 410 (205 boys and 205 girls) preschool children aged between 4- and 5-year-old selected within a large geographic area of Tunisia. Postural balance was assessed using a stabilometric platform under 4 sensory conditions. The mean center of pressure velocity (CoP-V) parameter was selected for analysis. Differences between gender and age groups were analysed using the Mann–Whitney U. Normative data were expressed in percentiles.ResultsSignificant gender effect was found in conditions where sensory inputs are most challenged with a significantly smaller mean CoP-V in girls compared to boys (p < 0.05). Moreover, 5-year-old children had significantly better postural balance than 4-year-old ones in almost all conditions (p < 0.05).SignificanceThe normative data established for Tunisian preschoolers provide useful comparative data for pediatricians, teachers and coaches for the early evaluation and monitoring of postural balance during this age. Gender and age-related differences should be considered in this population.  相似文献   
6.
7.
《Vaccine》2021,39(45):6601-6613
AKS-452 is a biologically-engineered vaccine comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain antigen (Ag) and human IgG1 Fc (SP/RBD-Fc) in clinical development for the induction and augmentation of neutralizing IgG titers against SARS-CoV-2 viral infection to address the COVID-19 pandemic. The Fc moiety is designed to enhance immunogenicity by increasing uptake via Fc-receptors (FcγR) on Ag-presenting cells (APCs) and prolonging exposure due to neonatal Fc receptor (FcRn) recycling. AKS-452 induced approximately 20-fold greater neutralizing IgG titers in mice relative to those induced by SP/RBD without the Fc moiety and induced comparable long-term neutralizing titers with a single dose vs. two doses. To further enhance immunogenicity, AKS-452 was evaluated in formulations containing a panel of adjuvants in which the water-in-oil adjuvant, Montanide™ ISA 720, enhanced neutralizing IgG titers by approximately 7-fold after one and two doses in mice, including the neutralization of live SARS-CoV-2 virus infection of VERO-E6 cells. Furthermore, ISA 720-adjuvanted AKS-452 was immunogenic in rabbits and non-human primates (NHPs) and protected from infection and clinical symptoms with live SARS-CoV-2 virus in NHPs (USA-WA1/2020 viral strain) and the K18 human ACE2-trangenic (K18-huACE2-Tg) mouse (South African B.1.351 viral variant). These preclinical studies support the initiation of Phase I clinical studies with adjuvanted AKS-452 with the expectation that this room-temperature stable, Fc-fusion subunit vaccine can be rapidly and inexpensively manufactured to provide billions of doses per year especially in regions where the cold-chain is difficult to maintain.  相似文献   
8.

Background

Treatment of advanced anal squamous cell cancer (SCC) is usually with the combination of cisplatin and 5-fluorouracil, which is associated with heterogeneous responses across patients and significant toxicity. We examined the safety and efficacy of a modified schedule, FOLFCIS (leucovorin, fluorouracil, and cisplatin), and performed an integrated clinical and genomic analysis of anal SCC.

Patients and Methods

We reviewed all patients with advanced anal SCC receiving first-line FOLFCIS chemotherapy – essentially a FOLFOX (leucovorin, fluorouracil, and oxaliplatin) schedule with cisplatin substituted for oxaliplatin – in our institution between 2007 and 2017, and performed deep sequencing to identify genomic markers of response and key genomic drivers.

Results

Fifty-three patients with advanced anal SCC (48 metastatic; 5 unresectable, locally advanced) received first-line FOLFCIS during this period; all were platinum-naive. The response rate was 48% (95% confidence interval [CI], 32.6%-63%). With a median follow-up of 41.6 months, progression-free survival and overall survival were 7.1 months (95% CI, 4.4-8.6 months) and 22.1 months (95% CI, 16.9-28.1 months), respectively. Among all patients with advanced anal SCC that underwent sequencing during the study period, the most frequent genomic alterations consisted of chromosome 3q amplification (51%) and mutations in PIK3CA (29%) and KMT2D (22%). No genomic alteration correlated with response to platinum-containing treatment. Although there were few cases, patients with human papillomavirus-negative anal SCC did not appear to benefit from FOLFCIS, and all harbored distinct genomic profiles with TP53, TERT promoter, and CDKN2A mutations.

Conclusions

FOLFCIS appears effective and safe as first-line chemotherapy in patients with advanced anal SCC and represents an alternative treatment option for these patients.  相似文献   
9.
BackgroundBody-worn inertial measurement unit (IMU) sensors have been widely used in postural stability and balance studies because of their low cost and convenience. In most of these studies, a single IMU sensor is attached to a waist belt near the body’s center of mass. Some populations such as pregnant women, however, may find a waist belt challenging in terms of fit and comfort. For this reason it may be useful to identify an alternative location for placement of an IMU and a more comfortable means for attaching the sensor to the body.Research questionDoes placing an IMU sensor in a pendant worn around the neck permit discrimination between conditions with varying postural stability?MethodsTwenty-six healthy participants performed three standing tasks (double-leg, tandem, and single-leg standing) under eyes-open and eyes-closed vision conditions to preliminarily assess the ability of the pendant sensor to discriminate between balance conditions. Discrimination based upon data from a belt-mounted IMU was assessed in the same trials. Differences in standard deviation of acceleration components, sway area, and jerkiness due to trial condition and sensor were evaluated using analysis of variance followed by post hoc comparisons. These data were also incorporated into receiver-operator characteristic (ROC) curve analysis to assess the effectiveness of each sensor at discriminating between conditions.ResultsStability was found to vary across conditions, but there was no interaction between stability and sensor location (all p ≥ 0.323). ROC curve analysis showed that sensors in both locations were good discriminators between conditions.SignificancePlacing an IMU in a pendant may be feasible for studying and monitoring postural instability. This approach may be especially valuable when considering populations for which wearing a belt is uncomfortable.  相似文献   
10.
《Vaccine》2016,34(24):2663-2670
Human metapneumovirus (HMPV) is a major cause of morbidity and mortality from acute lower respiratory tract illness, with most individuals seropositive by age five. Despite the presence of neutralizing antibodies, secondary infections are common and can be severe in young, elderly, and immunocompromised persons. Preclinical vaccine studies for HMPV have suggested a need for a balanced antibody and T cell immune response to enhance protection and avoid lung immunopathology. We infected transgenic mice expressing human HLA-A*0201 with HMPV and used ELISPOT to screen overlapping and predicted epitope peptides. We identified six novel HLA-A2 restricted CD8+ T cell (TCD8) epitopes, with M39–47 (M39) immunodominant. Tetramer staining detected M39-specific TCD8 in lungs and spleen of HMPV-immune mice. Immunization with adjuvant-formulated M39 peptide reduced lung virus titers upon challenge. Finally, we show that TCD8 from HLA-A*0201 positive humans recognize M39 by IFNγ ELISPOT and tetramer staining. These results will facilitate HMPV vaccine development and human studies.  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