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   5303篇
  免费   350篇
  国内免费   74篇
耳鼻咽喉   88篇
儿科学   69篇
妇产科学   85篇
基础医学   545篇
口腔科学   187篇
临床医学   501篇
内科学   1423篇
皮肤病学   55篇
神经病学   657篇
特种医学   270篇
外科学   897篇
综合类   8篇
预防医学   185篇
眼科学   47篇
药学   283篇
中国医学   9篇
肿瘤学   418篇
  2023年   94篇
  2022年   68篇
  2021年   249篇
  2020年   218篇
  2019年   234篇
  2018年   242篇
  2017年   156篇
  2016年   220篇
  2015年   233篇
  2014年   275篇
  2013年   353篇
  2012年   499篇
  2011年   472篇
  2010年   259篇
  2009年   225篇
  2008年   289篇
  2007年   316篇
  2006年   253篇
  2005年   238篇
  2004年   231篇
  2003年   199篇
  2002年   148篇
  2001年   24篇
  2000年   13篇
  1999年   20篇
  1998年   32篇
  1997年   23篇
  1996年   19篇
  1995年   17篇
  1994年   16篇
  1993年   14篇
  1992年   17篇
  1991年   11篇
  1990年   10篇
  1989年   4篇
  1988年   4篇
  1987年   5篇
  1986年   5篇
  1984年   2篇
  1982年   4篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1973年   3篇
  1964年   1篇
  1962年   1篇
  1961年   1篇
  1957年   1篇
  1940年   1篇
  1905年   1篇
排序方式: 共有5727条查询结果,搜索用时 15 毫秒
1.
Previous studies on the immunogenicity of SARS-CoV-2 mRNA vaccines showed a reduced seroconversion in cancer patients. The aim of our study is to evaluate the immunogenicity of two doses of mRNA vaccines in solid cancer patients with or without a previous exposure to the virus. This is a single-institution, prospective, nonrandomized study. Patients in active treatment and a control cohort of healthy people received two doses of BNT162b2 (Comirnaty, BioNTech/Pfizer, The United States) or mRNA-1273 (Spikevax, Moderna). Vaccine was administered before starting anticancer therapy or on the first day of the treatment cycle. SARS-CoV-2 antibody levels against S1, RBD (to evaluate vaccine response) and N proteins (to evaluate previous infection) were measured in plasma before the first dose and 30 days after the second one. From January to June 2021, 195 consecutive cancer patients and 20 healthy controls were enrolled. Thirty-one cancer patients had a previous exposure to SARS-CoV-2. Cancer patients previously exposed to the virus had significantly higher median levels of anti-S1 and anti-RBD IgG, compared to healthy controls (P = .0349) and to cancer patients without a previous infection (P < .001). Vaccine type (anti-S1: P < .0001; anti-RBD: P = .0045), comorbidities (anti-S1: P = .0274; anti-RBD: P = .0048) and the use of G-CSF (anti-S1: P = .0151) negatively affected the antibody response. Conversely, previous exposure to SARS-CoV-2 significantly enhanced the response to vaccination (anti-S1: P < .0001; anti-RBD: P = .0026). Vaccine immunogenicity in cancer patients with a previous exposure to SARS-CoV-2 seems comparable to that of healthy subjects. On the other hand, clinical variables of immune frailty negatively affect humoral immune response to vaccination.  相似文献   
2.
An increased number of patients is at risk of Candida spp. bloodstream infection (CBSI) in modern medicine. Moreover, the rising of antifungal resistance (AR) was recently reported. All consecutive CBSI occurred in our Hospital (consisting of 1,370 beds) between 2015 and 2018, were reviewed. For each case, Candida species, AR pattern, ward involved and demographic data of patients were recorded. Overall, 304 episodes of CBSI occurred, with a median (q1:first-,q3:third quartile) of 77 (71-82) CBSI/year. Over the years, a significant increase of CBSI due to C. albicans compared to non-albicans strains was recorded in medical wards (from 65% to 71%, p=0.030), while this ratio remained stable in others. An increase of resistant strains to multiple antifungals such as C. guillermondii was noticed in recent years (from 0% to 9.8%, p=0.008). Additionally, from 2015 to 2018 an increase in fluconazole-resistance was recorded in our Hospital (from 7.4% to 17.4%, p=0.025) and a slight increase in voriconazole-resistance (from 0% to 7% in 2018, p=0.161) was observed, while resistance to echinocandin and amphotericin B remained firmly below 2%.This study suggests a rapid spread of antifungal resistance in our Hospital; therefore, an appropriate antifungal stewardship programs is urgently warranted.  相似文献   
3.
4.
5.

Background

Accounts of cognitive processes in judgment and decision-making are frequently based on a dual-process framework, which reflects two qualitatively different types of processing: intuitive (Type 1) and analytical (Type 2) processes.

Objective

The present study investigated the effects of bilateral transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC) on judgment and decision-making performance.

Methods

Participants received anodal tDCS stimulation to the right DLPFC, left DLPFC or sham. There were 3 tasks: vignettes measuring heuristic thinking, belief bias syllogisms, and the cognitive reflection test (CRT), a measure of the ability to inhibit automatic responses to reach a correct solution. Fifty-four participants (mean age?=?24.63?±?4.46 years; 29 females) were recruited.

Results

Results showed that anodal tDCS to the right DLPFC was associated with an increase in cognitive reflection performance (Type 2 processing) as compared to left DLPFC and to sham. Logic thinking was reduced following anodal tDCS to the left DLPFC.

Conclusion

These findings are broadly consistent with a dual process framework, and cannot be explained by differences in cognitive ability and thinking style. The results demonstrate the involvement of the right DLPFC in cognitive reflection, and suggest the possibility of improving cognitive performance through tDCS.  相似文献   
6.
Cardiovascular Drugs and Therapy - Available animal models of acute heart failure (AHF) and their limitations are discussed herein. A novel and preclinically relevant porcine model of decompensated...  相似文献   
7.
8.
Introduction: Both the neuropsychological study of patients with category-specific semantic disorders (CSSD) and the experimental research on categorical processing in healthy subjects (HSs) have shown that men are mainly impaired with fruits and vegetables and women with animals and artifacts. Since this difference is more striking in patients with CSSD than in HSs, we hypothesized that the lack of power of some investigations conducted with HSs and the different methods used in studies conducted with HSs and patients with CSSD could explain some of these inconsistencies and that a study conducted with a very large number of HSs using visual naming tasks should strongly confirm the role of gender in categorical tasks.

Methods: Picture naming data gathered during the last ten years with our category-specificity paradigm from a large number (702) of HSs were reanalyzed.

Results: As predicted, men named significantly more animals and artifacts, while women named more plant life items.

Discussion: These data confirm that, if different domains of knowledge are studied in a very large sample of HSs using a picture naming task equivalent to the naming tasks used in most anatomo-clinical studies on CSSD, then the gender effects are highly significant.  相似文献   

9.

Purpose

The purpose of this study was to develop the modified research utilization questionnaire (M-RUQ) and to establish its content and face validity, construct validity, and reliability.

Methods

This study has a multiphase (three phases), methodological, and cross-sectional design. First, research utilization questionnaire (RUQ) was translated into Italian, which is the target language to develop the M-RUQ. Second, the RUQ psychometric proprieties were assessed using exploratory factorial analysis to identify ambiguous or problematic items (e.g., cross-loadings) (cross-sectional sampling A). The RUQ modification (i.e., item deleting, wording modification, and scoring procedure) represented the development of the M-RUQ among Italian nurses. The third phase was aimed to confirm the construct validity of the M-RUQ and to test its stability and internal consistency (cross-sectional sampling B).

Results

This study's findings show that M-RUQ has a three-dimensional structure and a total of 22 items. The M-RUQ shows evidence of validity and reliability. Precisely, the factorial structure coming from an exploratory factorial analysis on the first sample (n = 504) was confirmed by a final model of confirmatory factorial analysis (CFA) on a second sample (n = 362). The final CFA model showed adequate goodness of fit, where all the factor loadings showed values higher than .40. Cronbach's α was satisfactory for each domain and for the overall scale. Furthermore, the M-RUQ showed good stability described by the test–retest.

Conclusion

The M-RUQ should be used to assess research utilization among nurses for educational or research purposes to address the practice. Further research about its validity and reliability is suggested.  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