全文获取类型
收费全文 | 12003篇 |
免费 | 1504篇 |
国内免费 | 258篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 184篇 |
妇产科学 | 124篇 |
基础医学 | 1485篇 |
口腔科学 | 257篇 |
临床医学 | 1012篇 |
内科学 | 2129篇 |
皮肤病学 | 136篇 |
神经病学 | 736篇 |
特种医学 | 266篇 |
外国民族医学 | 2篇 |
外科学 | 570篇 |
综合类 | 1245篇 |
一般理论 | 3篇 |
预防医学 | 3310篇 |
眼科学 | 191篇 |
药学 | 1179篇 |
4篇 | |
中国医学 | 204篇 |
肿瘤学 | 668篇 |
出版年
2025年 | 3篇 |
2024年 | 119篇 |
2023年 | 290篇 |
2022年 | 404篇 |
2021年 | 567篇 |
2020年 | 522篇 |
2019年 | 484篇 |
2018年 | 431篇 |
2017年 | 483篇 |
2016年 | 458篇 |
2015年 | 551篇 |
2014年 | 796篇 |
2013年 | 979篇 |
2012年 | 768篇 |
2011年 | 827篇 |
2010年 | 646篇 |
2009年 | 620篇 |
2008年 | 613篇 |
2007年 | 660篇 |
2006年 | 537篇 |
2005年 | 410篇 |
2004年 | 383篇 |
2003年 | 288篇 |
2002年 | 263篇 |
2001年 | 256篇 |
2000年 | 189篇 |
1999年 | 153篇 |
1998年 | 140篇 |
1997年 | 127篇 |
1996年 | 124篇 |
1995年 | 88篇 |
1994年 | 76篇 |
1993年 | 66篇 |
1992年 | 70篇 |
1991年 | 59篇 |
1990年 | 38篇 |
1989年 | 30篇 |
1988年 | 39篇 |
1987年 | 25篇 |
1986年 | 26篇 |
1985年 | 33篇 |
1984年 | 18篇 |
1983年 | 16篇 |
1982年 | 14篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 11篇 |
1978年 | 6篇 |
1977年 | 13篇 |
1976年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 分析重庆市肺癌发病死亡和疾病负担归因于被动吸烟的情况,为开展肺癌防治提供建议。 方法 肺癌死亡个案数据来源于2019年重庆市肿瘤登记报告系统,被动吸烟率来自2013年重庆市慢性病及危险因素监测。计算人群归因危险度百分比(population attributable risk percent, PAR%)、被动吸烟导致的肺癌发病、死亡和疾病负担。采用Excel 2010与SPSS 25.0进行统计分析,率的比较采用χ2检验。 结果 2013年30岁及以上成年人被动吸烟率为52.37%。2019年重庆市30岁及以上人群肺癌发病率与标化发病率分别为118.44/10万与80.83/10万,死亡率与标化死亡率分别为96.51/10万、63.58/10万。肺癌发病率和死亡率归因于被动吸烟的PAR%分别为19.76和19.04,归因发病率与归因标化发病率分别为23.41/10万和16.34/10万,归因死亡率与归因标化死亡率分别为18.38/10万和12.40/10万。2019年重庆市30岁及以上肺癌早死所致寿命损失年率(years of life lost,YLL)、残疾所致寿命损失年率(years lived with disability,YLD)、调整伤残寿命损失年率(disability adjusted life year,DALY)分别为21.16‰、0.31‰、21.47‰,YLL率、YLD率、DALY率归因于被动吸烟的PAR%分别为21.16、19.76和20.49,归因YLL率为4.34‰,归因YLD率为0.06‰,归因DALY率为4.40‰。 结论 2019年重庆市30岁及以上人群肺癌发病率、死亡率、YLL率、DALY率高,被动吸烟率高,肺癌归因于被动吸烟的疾病负担重,应加强落实控烟工作。 相似文献
2.
Yun Chen Na Wang Xiaolian Dong Jianfu Zhu Yue Chen Qingwu Jiang Chaowei Fu 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2021,31(8):2416-2425
Background and aimsSome amino acids (AAs) may be associated with type 2 diabetes (T2DM). This study aimed to determine the associations of individual AAs with the development of T2DM in rural Chinese adults.Methods and resultsA cohort study of 1199 individuals aged 18 years or older was conducted from 2006 to 2008 in a rural community of Deqing, China, a repeated survey was done in 2015 and data linkage with the electronic health records system was performed each year for identifying new T2DM cases. A high-performance liquid chromatography approach was used to measure the baseline serum concentrations of 15 AAs. Cox proportional hazards models were used to examine the associations between AAs and the risk of incident T2DM. A total of 98 new T2DM cases were identified during the follow-up of 12 years on average. Among 15 AAs, proline was associated with an increased risk of incident T2DM after adjusted for age, sex, body mass index, fasting plasma glucose, family history of T2DM, smoking status, alcohol use, and history of hypertension, the adjusted hazard ratio for 1-standard deviation increment was 1.20 (95% confidence interval: 1.00, 1.43). The association tended to be more marked in subjects younger than 60 years and overweight/obese subjects. Among participants without hypertension, proline and phenylalanine were associated with an increased risk of incident T2DM, while aspartic acid was associated with a decreased risk.ConclusionSerum proline was associated with the risk of incident T2DM in rural Chinese adults and might be a potential predictor. 相似文献
3.
4.
Georg Hahn Sharon M. Lutz Julian Hecker Dmitry Prokopenko Michael H. Cho Edwin K. Silverman Scott T. Weiss Christoph Lange 《Genetic epidemiology》2021,45(1):82-98
locStra is an ‐package for the analysis of regional and global population stratification in whole‐genome sequencing (WGS) studies, where regional stratification refers to the substructure defined by the loci in a particular region on the genome. Population substructure can be assessed based on the genetic covariance matrix, the genomic relationship matrix, and the unweighted/weighted genetic Jaccard similarity matrix. Using a sliding window approach, the regional similarity matrices are compared with the global ones, based on user‐defined window sizes and metrics, for example, the correlation between regional and global eigenvectors. An algorithm for the specification of the window size is provided. As the implementation fully exploits sparse matrix algebra and is written in C++, the analysis is highly efficient. Even on single cores, for realistic study sizes (several thousand subjects, several million rare variants per subject), the runtime for the genome‐wide computation of all regional similarity matrices does typically not exceed one hour, enabling an unprecedented investigation of regional stratification across the entire genome. The package is applied to three WGS studies, illustrating the varying patterns of regional substructure across the genome and its beneficial effects on association testing. 相似文献
5.
Honghong Wang Xingang Li Shusen Sun Guifu Mao Ping Xiao Chan Fu Zhuoxin Liang Min Zheng Yuling Huang Haihong Tang Renhao Ou Ni Yang Xi Ling Zhigang Zhao 《Journal of pharmaceutical sciences》2018,107(5):1416-1422
An accurate dosage determination is required in neonates when antibiotics are used. The adult data cannot be simply extrapolated to the pediatric population due to significant individual differences. We aimed to identify factors impacting ceftazidime exposure in neonates and to provide drug dosing guidance to clinicians. Forty-three neonates aged less than 60 days with proven or suspected infections were enrolled in this study. After intravenous administration, blood samples were collected, and plasma ceftazidime concentration was determined using a HPLC method. Pharmacokinetic data were fitted using a nonlinear mixed-effects model approach. One-compartmental model could nicely characterize the ceftazidime in vivo behavior. The covariate test found that the postmenstrual age (day) was strongly associated with systemic drug clearance (L/h), and the effect of body weight (kg) was identified as the covariate on distribution volume (L). Compared with the base model, the addition of covariates improved the goodness-of-fit of the final model. Model validation (bootstrap, visual predictive check, and prediction-corrected visual predictive check) suggested a robust and reliable pharmacokinetic model was developed. Personalized dosage regimens were provided based on model simulations. The intravenous dose should be adjusted according to postmenstrual age, body weight, and minimum inhibitory concentration. 相似文献
6.
7.
Background
The Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue Scale is an internationally used validated measure. General population–based age- and sex-specific percentile norms are, however, not published to date, although these are needed as reference for the interpretation of clinical research data.Objectives
To assess the FACIT-Fatigue Scale in a large representative sample of the German general population to examine psychometric characteristics and factorial structure and to provide population-based norms.Methods
A nationally representative face-to-face household survey was conducted in Germany using the FACIT-Fatigue Scale. Item characteristics were examined. Internal consistency was determined using the Cronbach α. Dimensionality was analyzed using confirmatory factor analysis (CFA) and bifactor analysis. Scale score differences relating to sex and age were assessed. Sex- and age-specific percentiles were computed for the entire scale range.Results
Of 2426 participants, 55.7% were women, and the mean age was 49.8 ± 17.4 years. The FACIT-Fatigue Scale mean was 43.5 ± 8.3. Cronbach α was high at 0.92. Although fit indices of the CFA were below desired levels (root mean squared error of approximation = 0.144, comparative fit index = 0.846, and Tucker-Lewis index = 0.815), item loadings in the CFA and bifactor analysis confirm the scale’s unidimensionality. Women were more fatigued than men, and participants who were 70 years or older showed higher fatigue scores than younger respondents. Thus, sex- and age-specific population-based percentiles were provided.Conclusions
Reliability and validity of the German translation of the FACIT-Fatigue Scale were confirmed. This study provides general population–based sex- and age-specific FACIT-Fatigue Scale percentile norms for the first time, thereby contributing to a meaningful interpretation of clinical research data. 相似文献8.
本文对上海地区正常胎成人作了软组织侧貌的头影测量分析,认为侧貌形态的数值化测量,较目测或照片提供了更为可靠的疗效评价依据,其测量指标,对正颌外科手术设计,有重要的参考价值,甚至具有决定作用。 相似文献
9.
Quteish Taani DS 《Journal of oral rehabilitation》2003,30(1):110-112
This survey studies the reasons for periodontal extraction of permanent teeth in an adult Jordanian population. A random sample of 30 general dental practitioners (GDPs) from a list of 300 GDPs (1:10) was contacted. Of these, the 26 dentists who participated in this study were asked to record teeth extracted and give reasons for extraction. Personal and demographic information and clinical details were obtained from 898 patients aged from 20 to 60 years. A total of 1,098 teeth were extracted during the 3-month study period. The results of this study revealed that dental caries (56.4% overall) was the main reason for tooth extraction, especially in 20-39 year olds. Periodontal disease (23.4% overall) was the next most frequent indication for extraction and became the commonest cause of tooth extraction in patients aged 40 years or more. Other reasons for tooth loss accounted for only 20.2% of the series. Advanced periodontal disease represented by pocketing were the dominant pathology when tooth loss occurred as the result of periodontal disease. As far as the type of tooth was concerned, the most frequently extracted teeth were molars followed by premolars, regardless of whether their loss was the result of the caries or the periodontal disease. This study suggests that caries and its consequences are responsible for more tooth loss in patients less than 40 years of age while extraction because of periodontal problems increases with age, and more commonly related to pocketing. 相似文献
10.
Matti Telivuo DDS ; Pekka Kallio DDS MPH ; Mari-Anna Berg MA ; Heikki J. Korhonen MD ; Heikki Murtomaa DDS MPH PhD 《Journal of public health dentistry》1995,55(3):133-138
Objectives: A survey was conducted to study smokers' oral health behaviors and attitudes, and to determine if smokers were advised by their dentists to quit smoking. Methods : A random sample of 1,200 adults 15 to 64 years of age living in the province of North Karelia, Finland, was selected in each of two study years (1990 and 1991) and surveyed using a mail questionnaire. The 102-item questionnaire solicited information on smoking status, oral health behaviors, missing teeth, perceptions of tobacco's harmful effects on oral health, smoking status and quitting, and advice on smoking cessation provided by dentists. Variations in behaviors and opinions according to smoking status were analyzed. Results : Nonsmokers reported more frequent healthy oral health behaviors than did daily smokers, with the exception that no difference in toothbrushing frequencies existed among women. Daily smoking was associated with increased use of sugar in tea or coffee, and with more frequent alcohol consumption. Daily smoking was correlated with the number of missing teeth in bivariate analyses, but not in multivariate analyses. Fewer daily smokers than nonsmokers considered smoking to have harmful effects on oral health. The majority of daily smokers, however, wanted to quit. Eight percent of daily smokers reported that they had been advised by their dentist to quit. Conclusions : Dentists need to provide patients with counseling on tobacco use because of the desire of many smokers to quit. Counseling of smokers by the oral health team requires special attention and skills, because smokers' health behaviors and attitudes appear to be less favorable to oral health compared to nonsmokers. 相似文献