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   7864篇
  免费   902篇
  国内免费   144篇
耳鼻咽喉   51篇
儿科学   133篇
妇产科学   78篇
基础医学   825篇
口腔科学   78篇
临床医学   917篇
内科学   775篇
皮肤病学   33篇
神经病学   1639篇
特种医学   491篇
外科学   400篇
综合类   1198篇
一般理论   2篇
预防医学   825篇
眼科学   70篇
药学   759篇
  8篇
中国医学   483篇
肿瘤学   145篇
  2024年   8篇
  2023年   119篇
  2022年   167篇
  2021年   403篇
  2020年   397篇
  2019年   353篇
  2018年   320篇
  2017年   344篇
  2016年   328篇
  2015年   366篇
  2014年   606篇
  2013年   568篇
  2012年   477篇
  2011年   506篇
  2010年   384篇
  2009年   389篇
  2008年   342篇
  2007年   343篇
  2006年   332篇
  2005年   270篇
  2004年   222篇
  2003年   222篇
  2002年   167篇
  2001年   140篇
  2000年   103篇
  1999年   100篇
  1998年   68篇
  1997年   81篇
  1996年   38篇
  1995年   61篇
  1994年   63篇
  1993年   63篇
  1992年   43篇
  1991年   48篇
  1990年   61篇
  1989年   40篇
  1988年   40篇
  1987年   31篇
  1986年   33篇
  1985年   42篇
  1984年   40篇
  1983年   17篇
  1982年   26篇
  1981年   20篇
  1980年   30篇
  1979年   16篇
  1978年   16篇
  1977年   23篇
  1975年   8篇
  1973年   7篇
排序方式: 共有8910条查询结果,搜索用时 800 毫秒
1.

Objective

The aim of the study was to estimate the effect of the state-based reinsurance programs through the section 1332 State Innovation Waivers on health insurance marketplace premiums and insurer participation.

Data Source

2015 to 2022 Robert Wood Johnson Foundation Health Insurance Exchange Compare Datasets.

Study Design

An event study difference-in-differences (DD) model separately for each year of implementation and a synthetic control method (SCM) are used to estimate year-by-year effects following program implementation.

Data Collection/Extraction Methods

Not applicable.

Principal Findings

Reinsurance programs were associated with a decline in premiums in the first year of implementation by 10%–13%, 5%–19%, and 11%–17% for bronze, silver, and gold plans (p < 0.05). There is a trend of sustained declines especially for states that implemented their programs in 2019 and 2020. The SCM analyses suggest some effect heterogeneity across states but also premium declines across most states. There is no evidence that reinsurance programs affected insurer participation.

Conclusion

State-based reinsurance programs have the potential to improve the affordability of health insurance coverage. However, reinsurance programs do not appear to have had an effect on insurer participation, highlighting the need for policy makers to consider complementary strategies to encourage insurer participation.  相似文献   
2.
癫痫发作后状态(PIS)是指癫痫发作停止到恢复至发病前水平的异常状态,包括认知、运动、感觉、自主神经和精神行为等异常,症状多样,严重程度不一,持续数秒至数天不等,对患者的健康和生活质量产生很大影响。然而,目前国内外相关的研究较少,临床医生对此缺乏正确认识,容易误诊误治。本文将从PIS的定义、病理生理机制、临床表现、诊断和鉴别诊断、临床意义以及干预策略等进行综述,以提高临床医生的认识,并为今后临床研究提供参考。  相似文献   
3.
目的探讨中西医结合护理改善老年高血压患者心理状态及生活质量的效果。方法在医院2018年1月—2018年6月就诊的老年高血压患者中选出60例,按照随机数字法的原则,分成研究组(n=30)和参考组(n=30)。参考组采用单一西医护理,研究组在此之外联合中医护理,比较两组患者的临床疗效。结果入院时研究组与参考组SAS、SDS、SF-6评分差异不显著(P>0.05),护理后1月、3月与参考组相比,研究组SAS、SDS评分显著降低(P<0.05),SF-6评分显著升高(P<0.05);研究组患者对中西结合护理满意度为96.67%,参考组患者对西医护理满意度为73.33%,研究组满意度较参考组高,差异显著(P<0.05)。结论中西医结合护理能够有效改善老年高血压患者的心理状态,提高生活质量。  相似文献   
4.
ABSTRACT

Measuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised.  相似文献   
5.
邵奇敏  刘虹 《全科护理》2022,20(4):530-532,535
目的:探讨园艺互动干预应用于维持性血液透析病人中的效果。方法:选择本院收治的行维持性血液透析病人157例,按照入院时间先后顺序分为对照组77例,观察组80例。对照组实施常规干预,观察组实施园艺互动干预。对比两组干预前后心理状态、应对方式、生活质量及总体幸福感变化。结果:观察组干预12周后症状自评量表(SCL-90)各维度评分低于对照组(P<0.05);观察组干预12周后积极应对评分高于对照组,消极应对评分低于对照组(P<0.05);观察组生活质量各维度评分高于对照组(P<0.05);观察组总体幸福感评分高于对照组(P<0.05)。结论:园艺互动干预应用于维持性血液透析病人可改善心理状态及应对方式,提升生活质量与总体幸福感。  相似文献   
6.
A typical time series in functional magnetic resonance imaging (fMRI) exhibits autocorrelation, that is, the samples of the time series are dependent. In addition, temporal filtering, one of the crucial steps in preprocessing of functional magnetic resonance images, induces its own autocorrelation. While performing connectivity analysis in fMRI, the impact of the autocorrelation is largely ignored. Recently, autocorrelation has been addressed by variance correction approaches, which are sensitive to the sampling rate. In this article, we aim to investigate the impact of the sampling rate on the variance correction approaches. Toward this end, we first derived a generalized expression for the variance of the sample Pearson correlation coefficient (SPCC) in terms of the sampling rate and the filter cutoff frequency, in addition to the autocorrelation and cross‐covariance functions of the time series. Through simulations, we illustrated the importance of the variance correction for a fixed sampling rate. Using the real resting state fMRI data sets, we demonstrated that the data sets with higher sampling rates were more prone to false positives, in agreement with the existing empirical reports. We further demonstrated with single subject results that for the data sets with higher sampling rates, the variance correction strategy restored the integrity of true connectivity.  相似文献   
7.
目的评价血液科白血病疾病护理中应用健康教育的临床效果,为白血病护理工作提供参考。方法选择医院收治的白血病患者,总计60例。进行白血病患者随机分组护理,对照组与试验组各30例白血病患者,分别采取常规护理和常规护理+健康教育,比较2组白血病患者的负性情绪、自我效能状况评分以及护理满意度、护理依从率。结果试验组白血病患者干预后SAS、SDS、GSES评分均明显优于对照组,护理满意度与护理依从率均明显高于对照组,指标差异具有统计学意义,P>0.05。结论血液科白血病治疗期间配合落实常规护理、健康教育可以在提高患者自我效能的同时提高患者的依从性,符合患者身心护理需求,整体护理效果显著。  相似文献   
8.
《Vaccine》2016,34(20):2334-2341
Glycoconjugate vaccines are composed of capsular polysaccharides (CPSs) of a pathogenic bacteria covalently linked to carrier proteins. Pre-exposure to the carrier is known to influence the efficacy of the glycoconjugate, by inducing enhanced or suppressed anti-CPS response. Following our previous work on the immunogenicity of diphtheria toxin mutant CRM197 and formaldehyde-treated diphtheria toxoid (DT) as carriers for meningococcal A (MenA) conjugates in mouse model, we further investigated the role of the carrier on the immunological response to glycoconjugate vaccines. We previously showed that high dosage DT priming could result in carrier-induced epitopic suppression (CIES), an event that did not occur for CRM197 priming, and we observed that anti-DT IgGs could cross-react with DT based conjugates in vitro. Here, we confirmed the cross-reactivity of anti-carrier IgGs with DT conjugates in vivo. Furthermore, we analyzed the splenocytes of animals primed with the carrier and subsequently immunized with the MenA conjugate. Pre-exposure to the carrier protein, both CRM197 and DT, resulted in increased carrier-specific plasma and memory B cell response. However, only for CRM197 priming an enhanced carbohydrate-specific plasma cell response was observed. Analysis of circulating IgGs confirmed these observations. Memory to the CPS resulted to be non-influenced by carrier priming. Analysis of T helper response showed an enhancement effect for CRM197 priming, while DT priming resulted in constrained T cell activation. Stimulation with CRM197, which does not require formaldehyde detoxification, of splenocytes from animal immunized with DT suggested that the formaldehyde treatment used to produce DT might be the cause of limited presentation of the antigen to the T cells. We concluded that the dominant carrier-specific B cell response in case of limited T cell recruitment might explain the previously observed CIES phenomenon in case of DT priming.  相似文献   
9.
《Vaccine》2020,38(10):2315-2325
In the preparation of glycoconjugate vaccines in clinical practice, two highly immunogenic carrier proteins, CRM197 and tetanus toxoid (TT), are predominantly conjugated with the capsular polysaccharides (CPSs) of bacterial pathogens. In addition, TT has long been used as an effective vaccine to prevent tetanus. While these carrier proteins play an important role in immunogenicity and vaccine design alike, their defined human major histocompatibility complex class II (MHCII) T cell epitopes are inadequately characterized. In this current work, we use mass spectrometry to identify the peptides from these carrier proteins that are naturally processed and presented by human B cells via MHCII pathway. The MHCII-presented peptides are screened for their T cell stimulation using primary CD4+ T cells from four healthy adult donors. These combined methods reveal a subset of eleven CD4+ T cell epitopes that proliferate and stimulate human T cells with diverse MHCII allelic repertoire. Six of these peptides stand out as potential immunodominant epitopes by responding in three or more donors. Additionally, we provide evidence of these natural epitopes eliciting more significant T cell responses in donors than previously published TT peptides selected from T cell epitope screening. This study serves toward understanding carrier protein immune responses and thus enables the use of these peptides in developing novel knowledge-based vaccines to combat persisting problems in glycoconjugate vaccine design.  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