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   23679篇
  免费   1754篇
  国内免费   761篇
耳鼻咽喉   80篇
儿科学   535篇
妇产科学   169篇
基础医学   3248篇
口腔科学   240篇
临床医学   1149篇
内科学   2757篇
皮肤病学   261篇
神经病学   180篇
特种医学   201篇
外国民族医学   1篇
外科学   2491篇
综合类   2674篇
现状与发展   2篇
一般理论   2篇
预防医学   7136篇
眼科学   186篇
药学   2357篇
  5篇
中国医学   1208篇
肿瘤学   1312篇
  2024年   13篇
  2023年   592篇
  2022年   733篇
  2021年   1027篇
  2020年   929篇
  2019年   888篇
  2018年   937篇
  2017年   871篇
  2016年   853篇
  2015年   962篇
  2014年   1326篇
  2013年   1651篇
  2012年   1345篇
  2011年   1661篇
  2010年   1346篇
  2009年   1281篇
  2008年   935篇
  2007年   1185篇
  2006年   1102篇
  2005年   963篇
  2004年   949篇
  2003年   788篇
  2002年   623篇
  2001年   530篇
  2000年   436篇
  1999年   423篇
  1998年   271篇
  1997年   249篇
  1996年   180篇
  1995年   148篇
  1994年   121篇
  1993年   124篇
  1992年   84篇
  1991年   93篇
  1990年   61篇
  1989年   75篇
  1988年   54篇
  1987年   43篇
  1986年   48篇
  1985年   77篇
  1984年   44篇
  1983年   33篇
  1982年   27篇
  1981年   22篇
  1980年   18篇
  1979年   22篇
  1978年   15篇
  1977年   11篇
  1976年   6篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Vaccine》2022,40(27):3721-3726
We initiated a randomized, placebo-controlled, phase 1/2 trial to evaluate the safety and immunogenicity of the S-268019-b recombinant protein vaccine, scheduled as 2 intramuscular injections given 21 days apart, in 60 randomized healthy Japanese adults. We evaluated 2 regimens of the S-910823 antigen (5 μg [n = 24] and 10 μg [n = 24]) with an oil-in-water emulsion formulation and compared against placebo (n = 12). Reactogenicity was mild in most participants. No serious adverse events were noted. For both regimens, vaccination resulted in robust IgG and neutralizing antibody production at days 36 and 50 and predominant T-helper 1-mediated immune reaction, as evident through antigen-specific polyfunctional CD4+ T-cell responses with IFN-γ, IL-2, and IL-4 production on spike protein peptides stimulation. Based on the interim analysis, the S-268019-b vaccine is safe, produces neutralizing antibodies titer comparable with that in convalescent serum from COVID-19-recovered patients. However, further evaluation of the vaccine in a large clinical trial is warranted.  相似文献   
2.
《Value in health》2022,25(8):1290-1297
ObjectivesThe COVID-19 pandemic forms an unprecedented public health, economic, and social crisis. Uptake of vaccination is critical for controlling the pandemic. Nevertheless, vaccination hesitancy is considerable, requiring policies to promote uptake. We investigate Dutch citizens’ preferences for policies that aim to promote vaccination through facilitating choice of vaccination, profiling it as the norm, making vaccination more attractive through rewards, or punishing people who reject vaccination.MethodsWe conducted a discrete choice experiment in which 747 respondents were asked to choose between policies to promote vaccination uptake and their impacts on the number of deaths, people with permanent health problems, households with income loss, and a tax increase.ResultsRespondents generally had a negative preference for policies that promote vaccination. They particularly disliked policies that punish those who reject the vaccine and were more favorable toward policies that reward vaccination, such as awarding additional rights to vaccinated individuals through vaccination passports. Respondents who reject vaccination were in general much more negative about the policy options than respondents who consider accepting the vaccine. Nevertheless, vaccination passports are supported by both respondents who accept the vaccine, those who reject vaccination, and those who are unsure about vaccination.ConclusionsThis study provides concrete directions for governments attempting to increase the vaccination uptake in ways that are supported by the public. Our results could encourage policy makers to focus on policy options that make vaccination easier and reward people who take the vaccine, as especially the implementation of vaccination passports was supported.  相似文献   
3.
《Vaccine》2022,40(30):4038-4045
PurposeAs protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion.MethodsA prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster.ResultsAmong 110 participants, 56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25–11.67) folds and 2.40 (95 %CI 1.90–3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5–79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1–34.7) fold in and immunocompetent group, was observed.ConclusionA third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals.  相似文献   
4.
《Molecular therapy》2022,30(5):1885-1896
  1. Download : Download high-res image (90KB)
  2. Download : Download full-size image
  相似文献   
5.
ObjectiveCoronavirus disease 2019 (COVID-19) vaccine mandates are being implemented in health systems across the United States, and the impact on the radiology department workforce and operations becuase of vaccine hesitancy among health care workers is currently unknown. This article discusses the potential impact of the COVID-19 vaccine mandate on a large multicenter radiology department as well as strategies to mitigate those effects.MethodsWeekly vaccine compliance data were obtained for employees across the entire health system from August 17, 2021, through September 13, 2021, and radiology department–specific data were extracted. Vaccine compliance data was mapped to specific radiology job titles and the five different hospital locations.ResultsA total of 6% of radiology department employees were not fully vaccine compliant by the initial deadline of September 10, 2021. MR technologists and radiology technology assistants had the highest initial rates of noncompliance of 37% and 38%, respectively. Vaccine noncompliance rates by the mandate deadline ranged from 0.5% to 7.0% at the five hospital sites. Only one hospital required a decrease in imaging hours of operation because of the vaccine mandate.ConclusionDespite initial concerns about the impact of vaccine mandate noncompliance on departmental operations, there was ultimately little effect because of improved vaccine compliance after the mandate. Understanding individual employee and locoregional differences in vaccine compliance can help leaders proactively develop mitigation strategies to manage this new challenge during the COVID-19 pandemic.  相似文献   
6.
7.
Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.  相似文献   
8.
9.
《Vaccine》2022,40(13):1924-1927
High vaccine reactogenicities may reflect stronger immune responses, but the epidemiological evidence for coronavirus disease 2019 (COVID-19) vaccines is sparse and inconsistent. We observed that a fever of ≥38℃ after two doses of the BNT162b2 vaccine was associated with higher severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike IgG titers.  相似文献   
10.
《Vaccine》2022,40(32):4296-4300
Advanced computational methodologies suggested SARS-CoV-2, nonstructural proteins ORF1AB, ORF3a, as the source of immunodominant peptides for T cell presentation. T cell immunity is long-lasting and compatible with COVID-19 pathology. Based on the supporting clinical data, nonstructural SARS-CoV-2 protein vaccines could provide global immunity against COVID-19.  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