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   15516篇
  免费   990篇
  国内免费   323篇
耳鼻咽喉   33篇
儿科学   426篇
妇产科学   132篇
基础医学   2261篇
口腔科学   107篇
临床医学   780篇
内科学   2304篇
皮肤病学   102篇
神经病学   81篇
特种医学   95篇
外国民族医学   1篇
外科学   369篇
综合类   1251篇
现状与发展   1篇
一般理论   2篇
预防医学   6963篇
眼科学   39篇
药学   1090篇
  4篇
中国医学   41篇
肿瘤学   747篇
  2024年   21篇
  2023年   554篇
  2022年   987篇
  2021年   881篇
  2020年   715篇
  2019年   618篇
  2018年   664篇
  2017年   575篇
  2016年   589篇
  2015年   681篇
  2014年   788篇
  2013年   1164篇
  2012年   844篇
  2011年   981篇
  2010年   803篇
  2009年   776篇
  2008年   472篇
  2007年   642篇
  2006年   549篇
  2005年   485篇
  2004年   450篇
  2003年   405篇
  2002年   320篇
  2001年   286篇
  2000年   244篇
  1999年   228篇
  1998年   153篇
  1997年   161篇
  1996年   110篇
  1995年   80篇
  1994年   68篇
  1993年   64篇
  1992年   47篇
  1991年   53篇
  1990年   49篇
  1989年   56篇
  1988年   42篇
  1987年   33篇
  1986年   35篇
  1985年   52篇
  1984年   27篇
  1983年   15篇
  1982年   16篇
  1981年   12篇
  1980年   6篇
  1979年   6篇
  1978年   8篇
  1977年   3篇
  1976年   2篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
191.
《Vaccine》2021,39(44):6464-6469
Among 6146 hospital employees, 118 subjects with severe allergic background were identified through a screening questionnaire and stratified into 3 groups (Low-risk (LR), Intermediate (IR) and High-risk (HR) group), based on their allergic anamnesis.Data reports on hypersensitivity reactions (HypR) have been collected in both allergic and non-allergic subjects. Seventeen patients (14%) in the allergic population had a HypR after the first, the second or both doses. Skin manifestations were the most frequent ones. Allergic events were more frequent in HR (35%) than IR (10%; p = 0.005) or LR (0%; p = 0.074) subjects. No patient had anaphylaxis. All patients completed the vaccination schedule.13 HypR occurred in patients without severe allergic background (13/6028, 0,2%) including one (1/6148, 0.016% of total population) WAO grade-4 anaphylaxis.Our data suggest that BNT162b2 mRNA Covid-19 vaccine is relatively safe also in patients with severe allergic background; however, some precautions are required for high-risk patients.  相似文献   
192.
《Vaccine》2021,39(21):2843-2849
Pertussis, mainly caused by Bordetella pertussis, is a severe respiratory disease that can be fatal, especially in young infants. Vaccines, massively implemented since the middle of the last century, have substantially reduced the pertussis incidence, but have not been able to fully control the disease. One of the shortcomings of current pertussis vaccines is their inability to prevent infection by and transmission of B. pertussis, in contrast to immunity following natural infection. We have developed the live attenuated nasal vaccine BPZE1 and have shown that it prevents both disease and B. pertussis infection in preclinical models. This vaccine is now in clinical development. However, the initial clinical studies have suggested that vaccine take is hampered by pre-existing antibodies to pertactin. Here, we have constructed a pertactin-deficient BPZE1 derivative called BPZE1P in order to overcome this limitation. BPZE1P colonized the murine respiratory tract as efficiently as BPZE1 and induced antibodies at levels similar to those elicited by BPZE1. In the presence of pre-existing antibodies induced by acellular pertussis vaccination, BPZE1P colonized the mouse respiratory tract more efficiently than BPZE1. Both vaccines protected equally well the murine lungs and noses from challenge with laboratory and clinical strains of B. pertussis, including pertactin-deficient strains, against which current acellular pertussis vaccines are less efficient. BPZE1P may thus be an interesting alternative to BPZE1 to overcome vaccine take limitations due to pre-existing antibodies to pertactin.  相似文献   
193.
《Vaccine》2021,39(25):3435-3444
PurposeYoung adulthood is characterized by changes in health care decision-making, insurance coverage, and sexual risk. Although the human papillomavirus (HPV) vaccine is now approved for adults up to age 45, and catch-up vaccination is currently recommended up through age 26, vaccination rates remain low in young adults. This study explored perspectives on HPV vaccination among young adults receiving care at the student health center of a large public university.MethodsWe conducted semi-structured interviews (n = 27) and four focus groups with female and male undergraduate and graduate students (n = 18) and semi-structured interviews with health care providers (n = 6). Interviews and focus groups explored perceived risk of HPV infection, benefits of the HPV vaccine, and motivations for and barriers to HPV vaccination.ResultsMany young adults cited their parents’ views and recommendations from medical providers as influential on their decision-making process. Students perceived that cervical cancer prevention was a main benefit of the HPV vaccine and sexual activity was a risk factor for HPV infection. Students often lacked knowledge about the vaccine’s benefits for males and expressed some concerns about the safety and side effects of a vaccine perceived as new. Logistical barriers to vaccination included uncertainty over vaccination status and insurance coverage for the vaccine, and concerns about balancing the vaccine schedule with school obligations. Providers’ vaccine recommendations were impacted by health system factors, including clinical infrastructure, processes for recommending and documenting vaccination, and office visit priorities. Suggested vaccination promotion strategies included improving the timing and messaging of outreach efforts on campus and bolstering clinical infrastructure.ConclusionsAlthough college may be an opportune time to reach young adults for HPV vaccination, obstacles including navigating parental influence and independent decision-making, lack of awareness of vaccination status, and numerous logistical and system-level barriers may impede vaccination during this time.  相似文献   
194.
《Vaccine》2021,39(52):7541-7544
BackgroundThe Advisory Committee on Immunization Practices (ACIP) recommends routine vaccination with a quadrivalent meningococcal conjugate serogroup A,C,W,Y (MenACWY) vaccine at 11–12 years of age, with a booster dose at 16 years. ACIP also recommends meningococcal vaccination for persons at increased risk of meningococcal disease, including a 2-dose primary series and regular booster doses for persons at increased risk because of underlying medical conditions. U.S. cases of serogroup A, C, W, and Y meningococcal disease in persons previously vaccinated with MenACWY vaccine have not been systematically described since 2008. Characterization of these cases is important to understand potential factors leading to breakthrough disease.MethodsWe analyzed cases of serogroup A,C,W, and Y meningococcal disease reported through the National Notifiable Diseases Surveillance System (NNDSS) from 2014 through 2018. State health departments submitted additional information on risk factors and clinical course.ResultsDuring 2014–2018, 822 cases of serogroup A, C, W, and Y meningococcal disease were reported through NNDSS; 34 (4%) were in patients who previously received ≥ 1 dose of MenACWY vaccine. Twenty-three vaccinated patients were up-to-date on MenACWY vaccine per recommendations, and seven were not up-to-date; four were missing information on the number of doses received. Seventeen cases (50%) occurred > 3 years after the most recent dose. A significantly higher proportion of vaccinated patients were people living with HIV (PLWH) compared to unvaccinated patients. Eight of the 34 vaccinated patients were immunosuppressed, including five PLWH, one taking eculizumab, and two taking other immunosuppressive medications. The case fatality ratio did not differ between vaccinated and unvaccinated patients.ConclusionsImmunosuppression, incomplete vaccination, and waning immunity likely contributed to breakthrough cases of meningococcal disease among people who received MenACWY vaccine. Continued monitoring of serogroup A, C, W, and Y meningococcal disease in previously vaccinated persons will help inform meningococcal disease prevention efforts.  相似文献   
195.
《Vaccine》2022,40(1):37-42
IntroductionDue to the lack of understanding of the protective effects and safety of 23-valent pneumococcal polysaccharide vaccine (PPV23) in immune-deficient populations, the vaccination rate of PPV23 among HIV-infected patients is still very low in China. The main objectives of this study were to determine whether the efforts to assess measures for the prevention of pneumococcal pneumonia are still worthwhile, and provide designated vaccination program of HIV-infected persons for government policy based on.Methods60 HIV-infected adults in Lanshan county who had never been vaccinated with any pneumococcal vaccine were enrolled in this study, voluntary vaccination of PPV23 and One-year follow-up after vaccination can be completed.Result76.67% patients (46/60) had serologic response at 12 months after vaccine, CD4 count(≤500 cells/ul or > 500 cells/ul) and Month from diagnosis to first antiviral therapy (≤1 month or > 1 month) were related to antibody responses (p < 0.05).In this study, PPV23 was well tolerated, no adverse reaction was reported.11 Streptococcus pneumoniae pneumonia (9.17%,11/120) occurred in the Unvaccinated group and 1 case(1.67%,1/60)in the vaccination group within one year after vaccination(Fisher's exact probability, P = 0.225). The VE was 81.79%. The per capita benefit was 39.32 dollars, the benefit-cost ratio = 1.19. There are significant statistical differences between the vaccinated group and the non-vaccinated group in outpatient costs (p < 0.05, 95 %CI: 9.29–32.11), Medicine costs (p = 0.017, 95 %CI: 2.47–24.44), and disease related indirect costs (p = 0.038, 95 %CI: 0.93–33.63) within one year of vaccination.ConclusionOur study results showed that PPV23 can be safely and effectively administered to HIV-1 infected individuals and effectively preventing Streptococcal pneumonia. Considering the cost-benefit of vaccination among HIV-infected persons, as it has been reported in our study, it is necessary to promote the widespread use of the vaccine among HIV-infected persons in the future.  相似文献   
196.
《Vaccine》2022,40(7):994-1000
BackgroundSince 2007, Beijing has offered a free trivalent influenza vaccine (TIV) for residents aged ≥ 60 years and school students. The quadrivalent influenza vaccine (QIV) was administered to school children in 2018 and will be administered to elderly adults in the future. In addition, health care workers (HCWs) who are involved in the prevention and control of COVID-19 were included in the program in 2020. This study aimed to analyze the cost-effectiveness of a comprehensive list of combined strategies of TIV and QIV for school children, elderly adults, and HCWs to identify the most cost-effective strategy.MethodsA decision tree was developed to compare 1-year outcomes of TIV vs. QIV in three risk groups: school children, elderly adults, and HCWs. The outcome was incremental cost per quality-adjusted life-year (QALY). Probabilistic sensitivity analyses and scenario analyses were developed to assess the robustness of the results.ResultsFrom the perspective of society, this study found that the introduction of QIVs can be cost-effective for any and all targeted groups with a willingness-to-pay threshold of 3-fold GDP per capita. Among all programs, program H (all school children, elderly adults, and HCWs received the QIV) showed a 79% probability of being cost-effective with an incremental cost-effectiveness ratio (ICER) of 13,580 (95% CI: 13,294, 13,867) US$/QALY and was the preferred option in the base case scenario.ConclusionThe introduction of QIVs to school children, elderly adults, or HCWs is likely to be cost-effective, either separately or collectively. The introduction of QIV to school children, elderly adults, and health care workers simultaneously showed the highest probability of being cost-effective and was the preferred option.  相似文献   
197.
《Vaccine》2022,40(18):2568-2573
ObjectivesTo determine whether children aged 4–7 years with a diagnosis of autism spectrum disorders (ASD) were at increased risk of fever, febrile seizures, or emergency department (ED) visits following measles- or pertussis-containing vaccines compared with children without ASD.MethodsThe study included children born between 1995–2012, aged 4–7 years at vaccination, and members of six healthcare delivery systems within Vaccine Safety Datalink. We conducted self-controlled risk interval analyses comparing rates of outcomes in risk and control intervals within each group defined by ASD status, and then compared outcome rates between children with and without ASD, in risk and control intervals, by estimating difference-in-differences using logistic regressions.ResultsThe study included 14,947 children with ASD and 1,650,041 children without ASD. After measles- or pertussis-containing vaccination, there were no differences in association between children with and without ASD for fever (ratio of rate ratio for measles-containing vaccine = 1.07, 95% CI 0.58–1.96; for pertussis-containing vaccine = 1.16, 95% CI 0.63–2.15) or ED visits (ratio of rate ratio for measles-containing vaccine = 1.11, 95% CI 0.80–1.54; for pertussis-containing vaccine = 0.87, 95% CI 0.59–1.28). Febrile seizures were rare. Pertussis-containing vaccines were associated with small increased risk of febrile seizures in children without ASD.ConclusionChildren with ASD were not at increased risk for fever or ED visits compared with children without ASD following measles- or pertussis-containing vaccines. These results may provide further reassurance that these vaccines are safe for all children, including those with ASD.  相似文献   
198.
《Vaccine》2022,40(21):2960-2969
The enhanced transmissibility and immune evasion associated with emerging SARS-CoV-2 variants demands the development of next-generation vaccines capable of inducing superior protection amid a shifting pandemic landscape. Since a portion of the global population harbors some level of immunity from vaccines based on the original Wuhan-Hu-1 SARS-CoV-2 sequence or natural infection, an important question going forward is whether this immunity can be boosted by next-generation vaccines that target emerging variants while simultaneously maintaining long-term protection against existing strains. Here, we evaluated the immunogenicity of INO-4800, our synthetic DNA vaccine candidate for COVID-19 currently in clinical evaluation, and INO-4802, a next-generation DNA vaccine designed to broadly target emerging SARS-CoV-2 variants, as booster vaccines in nonhuman primates. Rhesus macaques primed over one year prior with the first-generation INO-4800 vaccine were boosted with either INO-4800 or INO-4802 in homologous or heterologous prime-boost regimens. Both boosting schedules led to an expansion of T cells and antibody responses which were characterized by improved neutralizing and ACE2 blocking activity across wild-type SARS-CoV-2 as well as multiple variants of concern. These data illustrate the durability of immunity following vaccination with INO-4800 and additionally support the use of either INO-4800 or INO-4802 in prime-boost regimens.  相似文献   
199.
200.
《Vaccine》2022,40(26):3713-3719
BackgroundIn response to this extraordinary outbreak, many countries and companies rush to develop an effective vaccine, authorize, and deliver it to all people across the world. Despite these extensive efforts, curbing this pandemic relies highly upon vaccination coverage. This study aimed to determine SARS-COV-2 vaccine uptake among Palestinian healthcare workers, the factors that influence vaccination uptake, and the motivators and barriers to vaccination.MethodsA cross-sectional study was conducted using an online anonymous self-administered questionnaire during April and May 2021, after the Palestinian Ministry of Health launched the COVID-19 vaccination campaign.The questionnaire collected socio-demographic characteristics, vaccination attitude and vaccination uptake status, and motivators and barriers towards vaccination. In addition, multivariate logistic regression was performed to identify the influencing factors of vaccination uptake.ResultsThe study included 1018 participants from different professions, including 560 (55.0%) females. Of the participants, 677 (66.5%; 95% CI: 63.5–69.4%) received the vaccine. Higher uptake was observed among males (aOR = 1.5; 95 %CI: 1.1–2.1), single HCWs (aOR = 1.3; 95 %CI: 1.1–1.8), HCWs working in the non-governmental sector (aOR = 1.6; 95 %CI: 1.2–2.4), higher monthly income (aOR = 1.9; 95 %CI: 1.4–2.8) and smoking (aOR = 1.5; 95 %CI: 1.1–3.5). The lower level of negative vaccination attitudes predicted higher intake; mistrust of vaccine belief (aOR = 1.6; 95 %CI: 1.4–1.7) and worries over unforeseen future effects (aOR = 1.2; 95 %CI: 1.1–1.3).ConclusionIn conclusion, the COVID-19 vaccination uptake was comparable to other studies worldwide but still needs to be improved, especially in the context of this ongoing global pandemic. It is imperative to invest resources to promote vaccination uptake and target all the vaccine misconceptions and fears.  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