全文获取类型
收费全文 | 8294篇 |
免费 | 953篇 |
国内免费 | 198篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 193篇 |
妇产科学 | 302篇 |
基础医学 | 496篇 |
口腔科学 | 141篇 |
临床医学 | 673篇 |
内科学 | 1445篇 |
皮肤病学 | 64篇 |
神经病学 | 583篇 |
特种医学 | 152篇 |
外科学 | 771篇 |
综合类 | 580篇 |
预防医学 | 2711篇 |
眼科学 | 91篇 |
药学 | 281篇 |
2篇 | |
中国医学 | 13篇 |
肿瘤学 | 923篇 |
出版年
2024年 | 10篇 |
2023年 | 376篇 |
2022年 | 632篇 |
2021年 | 637篇 |
2020年 | 826篇 |
2019年 | 496篇 |
2018年 | 467篇 |
2017年 | 530篇 |
2016年 | 494篇 |
2015年 | 484篇 |
2014年 | 829篇 |
2013年 | 565篇 |
2012年 | 454篇 |
2011年 | 391篇 |
2010年 | 425篇 |
2009年 | 402篇 |
2008年 | 199篇 |
2007年 | 229篇 |
2006年 | 176篇 |
2005年 | 123篇 |
2004年 | 105篇 |
2003年 | 81篇 |
2002年 | 78篇 |
2001年 | 57篇 |
2000年 | 41篇 |
1999年 | 55篇 |
1998年 | 60篇 |
1997年 | 42篇 |
1996年 | 46篇 |
1995年 | 33篇 |
1994年 | 21篇 |
1993年 | 16篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 14篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有9445条查询结果,搜索用时 296 毫秒
61.
Parle-McDermott A Mills JL Kirke PN O'Leary VB Swanson DA Pangilinan F Conley M Molloy AM Cox C Scott JM Brody LC 《Journal of human genetics》2003,48(4):190-193
The thermolabile variant (677TT) of methylenetetrahydrofolate reductase (MTHFR) is a known risk factor for neural tube defects
(NTDs). The relationship between a second MTHFR polymorphism (1298A→C) and NTD risk has been inconsistent between studies.
We genotyped 276 complete NTD triads (mother, father and child affected with an NTD) and 256 controls for MTHFR 1298A→C. Our
findings do not support a role for the 1298A→C polymorphism in NTDs (OR 0.85 (95% CI 0.49–1.47), p= 0.55), nor do we observe a combined effect with the 677C→T polymorphism.
Electronic Publication 相似文献
62.
Martijn W Heymans Dirk L Knol Willem van Mechelen Henrica CW de Vet 《BMC medical research methodology》2007,7(1):33
Background
Missing data is a challenging problem in many prognostic studies. Multiple imputation (MI) accounts for imputation uncertainty that allows for adequate statistical testing. We developed and tested a methodology combining MI with bootstrapping techniques for studying prognostic variable selection. 相似文献63.
Hao Wang Ingeborg Barisic Maria Loane Marie‐Claude Addor Linda M. Bailey Miriam Gatt Kari Klungsoyr Olatz Mokoroa Vera Nelen Amanda J. Neville Mary O'Mahony Anna Pierini Anke Rissmann Christine Verellen‐Dumoulin Hermien E.K. de Walle Awi Wiesel Katarzyna Wisniewska Lolkje T.W. de Jong‐van den Berg Helen Dolk Babak Khoshnood Ester Garne 《American journal of medical genetics. Part A》2019,179(4):595-601
We aimed to assess prevalence, birth outcome, associated anomalies and prenatal diagnosis of congenital clubfoot in Europe using data from the EUROCAT network, and to validate the recording of congenital clubfoot as a major congenital anomaly by EUROCAT registries. Cases of congenital clubfoot were included from 18 EUROCAT registries covering more than 4.8 million births in 1995–2011. Cases without chromosomal anomalies born during 2005–2009, were randomly selected for validation using a questionnaire on diagnostic details and treatment. There was 5,458 congenital clubfoot cases of which 5,056 (93%) were liveborn infants. Total prevalence of congenital clubfoot was 1.13 per 1,000 births (95% CI 1.10–1.16). Prevalence of congenital clubfoot without chromosomal anomaly was 1.08 per 1,000 births (95% CI 1.05–1.11) and prevalence of isolated congenital clubfoot was 0.92 per 1,000 births (95% CI 0.90–0.95), both with decreasing trends over time and large variations in prevalence by registry. The majority of cases were isolated congenital clubfoot (82%) and 11% had associated major congenital anomalies. Prenatal detection rate of isolated congenital clubfoot was 22% and increased over time. Among 301 validated congenital clubfoot cases, diagnosis was confirmed for 286 (95%). In conclusion, this large population‐based study found a decreasing trend of congenital clubfoot in Europe after 1999–2002, an increasing prenatal detection rate, and a high standard of coding of congenital clubfoot in EUROCAT. 相似文献
64.
Antibiotic-resistant infections in primary care are symptomatic for longer and increase workload: outcomes for patients with E.coli UTIs
下载免费PDF全文
![点击此处可从《The British journal of general practice》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Christopher C Butler Sharon Hillier Zoë Roberts Frank Dunstan Anthony Howard Stephen Palmer 《The British journal of general practice》2006,56(530):686-692
BACKGROUND: Antimicrobial resistance is considered to be one of the major threats to public health. However, the practical implications for patients and workload in primary care are largely unknown. AIM: To determine outcomes for patients managed in primary care with an antibiotic resistant compared to an antibiotic sensitive Escherichia coli (E. coli) urinary tract infection (UTI). DESIGN: Nested case control study with prospective measurement of outcomes. SETTING: Ten general practices in South Wales. METHOD: Patients consulting with symptoms suggestive of UTI identified through systematic sampling, and with a laboratory proven E. coli infection, were followed up by interview 1 month after their consultations and by searching of their medical records. RESULTS: Nine hundred and thirty-two patients were interviewed and had their medical records reviewed. The risk of patients reporting 'feeling poorly', 'frequency or pain on urinating' and being 'out of action' for more than 5 days after consulting was significantly increased for patients with resistant compared to sensitive infections. After adjusting for risk factors, there was an increased risk of 'frequency or pain on urinating' and 'being out of action' for those infected with a resistant E. coli. The median number of maximum reported days with at least one symptom was 12 days for patients with E. coli infections resistant to trimethoprim, 7 days for infections resistant to ampicillin, 7 days for infections resistant to any antibiotic, and 5 days for infections sensitive to all tested antibiotics. Even if treated with an appropriate antibiotic, infections caused by a resistant strain were symptomatic for longer. For those infected with an organism resistant to at least one antibiotic, the odds ratio (OR) for re-visiting their GP within the next 30 days for the UTI was 1.47 (95% confidence interval [CI] = 1.10 to 1.95). The OR was 1.49 (95% CI = 1.11 to 2.00) for ampicillin resistance and 2.48 (95% CI = 1.70 to 3.59) for trimethoprim resistance. CONCLUSIONS: Resistant E. coli UTIs are symptomatic for longer and cause increased work load in general practice. 相似文献
65.
Alessio Coi Michele Santoro Ester Garne Anna Pierini Marie‐Claude Addor Jean‐Luc Alessandri Jorieke E. H. Bergman Fabrizio Bianchi Ljubica Boban Paula Braz Clara Cavero‐Carbonell Miriam Gatt Martin Haeusler Kari Klungsøyr Jennifer J. Kurinczuk Monica Lanzoni Nathalie Lelong Karen Luyt Olatz Mokoroa Carmel Mullaney Vera Nelen Amanda J. Neville Mary T. O'Mahony Isabelle Perthus Judith Rankin Anke Rissmann Florence Rouget Bruno Schaub David Tucker Diana Wellesley Katarzyna Wisniewska Nataliia Zymak‐Zakutnia Ingeborg Barišić 《American journal of medical genetics. Part A》2019,179(9):1791-1798
Achondroplasia is a rare genetic disorder resulting in short‐limb skeletal dysplasia. We present the largest European population‐based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. All cases of achondroplasia notified to 28 EUROCAT registries (1991–2015) were included in the study. Prevalence, birth outcomes, prenatal diagnosis, associated anomalies, and the impact of paternal and maternal age on de novo achondroplasia were presented. The study population consisted of 434 achondroplasia cases with a prevalence of 3.72 per 100,000 births (95%CIs: 3.14–4.39). There were 350 live births, 82 terminations of pregnancy after prenatal diagnosis, and two fetal deaths. The prenatal detection rate was significantly higher in recent years (71% in 2011–2015 vs. 36% in 1991–1995). Major associated congenital anomalies were present in 10% of cases. About 20% of cases were familial. After adjusting for maternal age, fathers >34 years had a significantly higher risk of having infants with de novo achondroplasia than younger fathers. Prevalence was stable over time, but regional differences were observed. All pregnancy outcomes were included in the prevalence estimate with 80.6% being live born. The study confirmed the increased risk for older fathers of having infants with de novo achondroplasia. 相似文献
66.
目的 探究家庭社会经济状况(SES)与3岁以内儿童生长发育及营养状况的关系,为我国儿童预防保健提供科学依据。方法 数据源于2015年中国九市7岁以下儿童体格发育调查的西安地区数据。研究共纳入父/母亲文化程度、父/母亲职业和家庭年收入5项指标因子,构建了SES综合指标作为自变量。结局变量为身长、体重和评估的营养状况结局。调整儿童性别和月龄后,分别建立线性回归和Logistic回归模型,分析SES与身长体重和营养结局的关系。结果 研究共纳入3岁以内儿童12 017人,经评估营养不良者281人(2.3%),营养过剩者531人(4.4%)。调整儿童性别和月龄后,与低水平SES儿童相比,中等水平SES儿童身长增加0.32 cm(95%CI:0.16~0.47),发生营养过剩的风险降低20%(OR =0.80, 95%CI:0.65~0.98);高水平儿童身长增加0.77 cm(95%CI:0.61~0.92),体重增加0.06 kg(95%CI:0.006~0.12),发生营养过剩的风险降低33%(OR=0.67, 95%CI:0.53~0.83)。结论 较好的社会经济状况可能降低营养过剩的风险,有助于儿童的发育与营养健康。应改善家庭育儿环境,加强对低SES家庭的儿保宣教,提高儿童的健康水平。 相似文献
67.
《Health & place》2022
The foodscape (the built food environment) is considered one of the driving factors of the higher burden of obesity and chronic disease observed in low socio-economic status (SES) groups. Traditional data collection methods struggle to accurately capture actual access and exposure to the foodscape (realised foodscape). We assess the use of anonymised mobile phone location data (location data) in foodscape studies by applying them to a case study in Perth, Western Australia to test the hypothesis that lower SES groups have poorer realised foodscapes than high SES groups. Kernel density estimation was used to calculate realised foodscapes of different SES groups and home foodscape typologies, which were compared to home foodscapes of the different groups. The location data enabled us to measure realised foodscapes of multiple groups over an extended period and at the city scale. Low SES groups had poor availability of food outlets, including unhealthy outlets, in their home and realised foodscapes and may be more susceptible to a poor home foodscape because of low mobility. 相似文献
68.
《Journal of the American Medical Directors Association》2021,22(7):1512-1517
ObjectivesThough many studies have explored differences between spouses and adult children in dementia care, empirical evidence is lacking on racial- and ethnic-minority populations. To fill this research gap, this study examined care tasks, caregiver burden, and depressive symptoms of Chinese spouse and adult-child caregivers in dementia care. Guided by the stress process model, this study asked 3 questions: Do spouse and adult-child caregivers take up different care tasks and experience different levels of caregiver burden and depressive symptoms? Does gender moderate the differences between spouse and adult-child caregivers? Whether care tasks and burden mediate the association between being a spouse/adult-child caregiver and depressive symptoms?Setting and ParticipantsData were collected from a questionnaire-based survey of Chinese Americans who provided care for their family members with dementia in New York City. The analytical sample included 126 Chinese spouse or adult-child caregivers.MethodsCare tasks was indicated by intensity of 8 types of care tasks. Caregiver burden and depressive symptoms were measured by Zarit's Burden Interview and the 10-item Center for Epidemiologic Studies Depression Scale. Linear regression, interaction term (spouse/adult-child caregiver by gender), and path analysis were conducted to address the 3 questions.ResultsThe results of linear regression show no significant difference in care tasks between the 2 groups, but spouse caregivers had significantly higher levels of caregiver burden and depressive symptoms than adult children. Wives had higher levels of caregiver burden and depressive symptoms than husbands, daughters, and sons. Caregiver burden mediated the association between being a spouse caregiver and higher depressive symptoms, whereas care tasks did not shape such association.Conclusions and ImplicationsThis study highlighted the emotional stress of Chinese American older adults in providing care for their spouses. The findings indicate the necessity of developing culturally meaningful activities to support Chinese American spouse caregivers. 相似文献
69.
Here we investigated nationwide clinical Bordetella pertussis isolated during 2005–2017 from different provinces of Iran, a country with more than 50 years whole cell vaccine immunisation history. Our results revealed the ongoing increase in the population of ptxP3/fim3–2 B. pertussis isolates in different provinces which were differentiated into nine clades. The largest clade (clade 8) which was previously found to be prevalent in Tehran was also prevalent across the country and clade 5 with ptxP3/prn9 genotype has also increased in frequency (14% of all ptxP3 isolates) in recent years. Furthermore, we detected the first ptxP3 B. pertussis isolates that does not express filamentous hemagglutinin (FhaB) as one of the major antigens of the pathogen and a key component of the acellular pertussis vaccine. 相似文献
70.