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   59606篇
  免费   3614篇
  国内免费   1612篇
耳鼻咽喉   832篇
儿科学   2914篇
妇产科学   344篇
基础医学   4133篇
口腔科学   483篇
临床医学   7481篇
内科学   12265篇
皮肤病学   631篇
神经病学   1998篇
特种医学   941篇
外国民族医学   5篇
外科学   3930篇
综合类   10467篇
一般理论   2篇
预防医学   3396篇
眼科学   216篇
药学   5684篇
  45篇
中国医学   3925篇
肿瘤学   5140篇
  2024年   35篇
  2023年   916篇
  2022年   1578篇
  2021年   2376篇
  2020年   2222篇
  2019年   1805篇
  2018年   1727篇
  2017年   1981篇
  2016年   2082篇
  2015年   2208篇
  2014年   4771篇
  2013年   4557篇
  2012年   4035篇
  2011年   4474篇
  2010年   3415篇
  2009年   3019篇
  2008年   2791篇
  2007年   2716篇
  2006年   2295篇
  2005年   1981篇
  2004年   1649篇
  2003年   1326篇
  2002年   1071篇
  2001年   1011篇
  2000年   804篇
  1999年   785篇
  1998年   600篇
  1997年   471篇
  1996年   539篇
  1995年   567篇
  1994年   526篇
  1993年   444篇
  1992年   421篇
  1991年   360篇
  1990年   344篇
  1989年   327篇
  1988年   306篇
  1987年   234篇
  1986年   202篇
  1985年   323篇
  1984年   272篇
  1983年   171篇
  1982年   214篇
  1981年   159篇
  1980年   158篇
  1979年   145篇
  1978年   109篇
  1977年   91篇
  1976年   90篇
  1975年   34篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
《Pancreatology》2022,22(8):1175-1180
BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis.  相似文献   
2.
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.
5.
目的 调查社区老年人常见的14种慢性病共病情况及不良生活方式共存现象。 方法 采用方便抽样的方法抽取厦门市社区906例老年人群为研究对象,使用自设问卷调查研究对象的慢病共存及不良方式共存现象,使用检验和多因素logistic回归方法进行分析。结果 共纳入906例老年人,慢性病患病率为79.5%,老年人慢性病共病患病率为58.9%。主要的不良生活方式是BMI异常(46.8%)、饮酒(40.5%)、睡眠时间少(37.9%)、缺乏锻炼(35.2%)、吸烟(32.8%)等。多因素logistic回归分析显示,女性(OR=2.232,95%CI:1.474~3.380,P<0.001)、高龄(OR=2.038,95%CI:1.234~3.365,P=0.001)、有慢性病家族史(OR=2.854,95%CI:1.943~4.194,P<0.001)、肥胖(OR=2.571,95%CI:1.096~6.033,P=0.030)、饮酒(OR=3.582,95%CI:2.531~5.071,P<0.001)、吸烟(OR=1.789,95%CI:1.172~2.732,P=0.007)、嗜盐(OR=1.818,95%CI:1.170~2.823,P=0.008)、嗜油(OR=2.023,95%CI:1.153~3.550,P=0.010)、睡眠质量差(OR=2.091,95%CI:1.360~3.215,P=0.001)的老年人,慢性病共病的比例高。 结论 厦门市社区老年人慢性病共病和不良生活方式共存现象严重。肥胖、饮酒、吸烟、嗜盐、嗜油、睡眠质量差等行为生活方式是慢性病重要的可干预因素,社区工作者应提高社区居民对健康生活方式重要性的认识,促使其主动改变不良生活方式并长期坚持健康的生活方式,以降低其慢性病的发病风险,减少其伤残程度,提高生活质量。  相似文献   
6.
ObjectiveThere is a paucity of data concerning the use of granulocyte colony-stimulating factors (G-CSFs) in pediatric patients with acute lymphoblastic leukemia (ALL). The aim of the present study was to evaluate the effect of G-CSF use on relapse-free and overall survival in 358 consecutive, newly diagnosed pediatric ALL patients uniformly treated at the same institution between April 2012 and April 2020.Materials and MethodsPatients were evaluated in two separate periods, based on the G-CSF treatment approach. All patients who underwent ALL treatment between April 2012 and December 2016 received G-CSF (G-CSF+ arm; n: 245) in the course of the protocol for reducing the risk of febrile neutropenia and/or inducing neutrophil recovery to prevent any treatment delay. No patients after December 2016 received G-CSF, even if they belonged to the high-risk group, and these were included in the G-CSF? arm (n: 113).ResultsEstimated mean relapse-free (106.5 months; 95 % CI 102?110.8 vs 82 months 95 % CI 75.2?88.9; p: 0.794) and overall survival (111.4 months; 95 % CI 108?114.8 vs 85 months 95 % CI 80.4?89.8; p: 0.431) rates were similar between the G-CSF+ and G-CSF? groups.ConclusionsOur findings indicate that G-CSF use during ALL treatment had no effect on relapse rates or overall survival.  相似文献   
7.
8.
《Vaccine》2022,40(19):2679-2695
Vaccinations are essential for preventing infectious diseases in children with chronic diseases as they have increased risk of infection from frequent use of biologics. Response to immunizations in this group is not well known.ObjectiveA systematic review was performed to evaluate three primary outcomes: efficacy; immunogenicity; and safety of vaccines in children with chronic conditions treated with biologics.MethodsThe protocol for our systematic review and meta-analysis was registered and published with PROSPERO. We searched electronic bibliographic databases for studies published from 2009 to 2019, focusing on vaccinations in children with chronic conditions treated with biologics.ResultsWe retrieved 532 records. Thirty-one full-text articles were selected, and 14 were included in the meta-analysis. No significant publication bias was found. Efficacy: limited data are available regarding the efficacy of vaccination, as most studies have focused on immunogenicity as surrogate outcome for efficacy. Immunogenicity: patients receiving anti-TNF-alpha therapy had a statistically significant risk of poor seroconversion (p = 0.028) and seroprotection by the serotype B influenza vaccine [inflammatory bowel disease (IBD) p = 0.013; juvenile idiopathic arthritis (JIA) p = 0.004]. We found adequate responses with H1N1 and H3N2 serotypes. Few studies existed for pneumococcal, hepatitis A virus, hepatitis B virus, varicella-zoster virus, Measles Mumps Rubella virus, and multiple vaccine administration. Safety: vaccine administration was not associated with serious side effects, but JIA patients on anti-TNF alpha therapy had a statistically significant risk of presenting with myalgia or arthralgia postinfluenza vaccine (p = 0.014).ConclusionsMore evidence concerning efficacy, immunogenicity, and safety of vaccinations is needed to guide physicians in the vaccine decision process for this pediatric population.  相似文献   
9.
目的 了解稳定期慢性阻塞性肺疾病 (chronic obstructive pulmonary disease,COPD) 患者报告结局现状,分析其影响因素及与炎症指标的相关性,为开展以患者为中心的早期护理干预提供依据。 方法 采用便利抽样法,选取2020年10月—2021年7月于南宁市某三级甲等医院呼吸内科门诊就诊的稳定期COPD患者作为调查对象,采用一般资料调查表、COPD患者报告结局量表修订版 (the Modified Patient-Reported Outcome Scale for COPD,mCOPD-PRO) 进行调查,并收集患者就诊时炎症指标的结果。采用多元线性回归分析稳定期COPD患者报告结局的影响因素,采用相关性分析探讨患者报告结局与炎症指标的关系。结果 该研究共纳入204例稳定期COPD患者,mCOPD-PRO得分为 (1.75±0.58) 分。多元线性回归分析显示,性别、合并疾病数量、病程、肺功能分级是稳定期COPD患者报告结局的影响因素 (P<0.05),可解释稳定期COPD患者报告结局10.8%的总变异。相关性分析显示,白细胞计数、中性粒细胞计数、嗜酸性粒细胞计数与稳定期COPD患者的mCOPD-PRO得分呈正相关 (P<0.05) ;总白蛋白浓度与其呈负相关 (P<0.05) 。结论 稳定期COPD患者报告结局有待改善,女性、合并疾病数量>3种、病程较长、肺功能分级较高的COPD患者报告的结局较差。COPD患者报告结局与白细胞计数、中性粒细胞计数、嗜酸性粒细胞计数、总白蛋白浓度相关。护理人员应关注稳定期COPD患者报告结局及炎症指标,在早期采取针对性的干预措施,以改善患者的生活质量。  相似文献   
10.
《Vaccine》2022,40(7):1001-1009
Vaccination guidelines for dogs and cats indicate that core vaccines (for dogs, rabies, distemper, adenovirus, parvovirus; for cats, feline parvovirus, herpes virus-1, calicivirus) are essential to maintain health, and that non-core vaccines be administered according to a clinician’s assessment of a pet’s risk of exposure and susceptibility to infection. A reliance on individual risk assessment introduces the potential for between-practice inconsistencies in non-core vaccine recommendations. A study was initiated to determine non-core vaccination rates of dogs (Leptospira, Borrelia burgdorferi, Bordetella bronchiseptica, canine influenza virus) and cats (feline leukemia virus) in patients current for core vaccines in veterinary practices across the United States. Transactional data for 5,531,866 dogs (1,670 practices) and 1,914,373 cats (1,661 practices) were retrieved from practice management systems for the period November 1, 2016 through January 1, 2020, deidentified and normalized. Non-core vaccination status was evaluated in 2,798,875 dogs and 788,772 cats that were core-vaccine current. Nationally, median clinic vaccination rates for dogs were highest for leptospirosis (70.5%) and B. bronchiseptica (68.7%), and much lower for canine influenza (4.8%). In Lyme-endemic states, the median clinic borreliosis vaccination rate was 51.8%. Feline leukemia median clinic vaccination rates were low for adult cats (34.6%) and for kittens and 1-year old cats (36.8%). Individual clinic vaccination rates ranged from 0 to 100% for leptospirosis, B. bronchiseptica and feline leukemia, 0–96% for canine influenza, and 0–94% for borreliosis. Wide variation in non-core vaccination rates between clinics in similar geographies indicates that factors other than disease risk are driving the use of non-core vaccines in pet dogs and cats, highlighting a need for veterinary practices to address gaps in patient protection. Failure to implement effective non-core vaccination strategies leaves susceptible dogs and cats unprotected against vaccine-preventable diseases.  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