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   1436篇
  免费   237篇
  国内免费   11篇
耳鼻咽喉   1篇
儿科学   161篇
妇产科学   44篇
基础医学   109篇
口腔科学   24篇
临床医学   171篇
内科学   331篇
皮肤病学   10篇
神经病学   44篇
特种医学   13篇
外科学   37篇
综合类   84篇
预防医学   583篇
眼科学   1篇
药学   33篇
中国医学   20篇
肿瘤学   18篇
  2024年   2篇
  2023年   43篇
  2022年   36篇
  2021年   95篇
  2020年   94篇
  2019年   96篇
  2018年   81篇
  2017年   94篇
  2016年   83篇
  2015年   80篇
  2014年   107篇
  2013年   175篇
  2012年   82篇
  2011年   108篇
  2010年   75篇
  2009年   79篇
  2008年   73篇
  2007年   87篇
  2006年   39篇
  2005年   34篇
  2004年   29篇
  2003年   17篇
  2002年   24篇
  2001年   17篇
  2000年   3篇
  1999年   10篇
  1998年   3篇
  1997年   2篇
  1995年   3篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1980年   1篇
排序方式: 共有1684条查询结果,搜索用时 78 毫秒
1.
In the United States, renal cell carcinoma (RCC) incidence and the prevalence of obesity, an established risk factor for RCC, have been increasing for several decades. RCC is more common among older individuals. We sought to quantify the contribution of excess adiposity to the rising incidence of RCC among individuals 60 years or older. National Institutes of Health-American Association of Retired Persons Diet and Health Study data (n = 453 859 participants, enrolled in 1995-1996, age at enrollment 50-71 years) were used to estimate multivariable-adjusted hazard ratios (HRs) for RCC across body mass index categories and HRs associated with smoking. Population attributable fractions (PAFs) were calculated using estimated HRs and annual overweight/obesity prevalence from the National Health Interview Survey (1985-2008). PAF estimates were combined with RCC incidence from Surveillance, Epidemiology and End Results-13 to calculate annual percent changes in RCC incidence attributable (and unrelated) to overweight/obesity. We found that between 1995 and 2018, among individuals aged 60 years and older, PAF for overweight/obesity increased from 18% to 29% for all RCCs. In comparison, the PAF for smoking declined from 12% to 9%. RCC incidence increased 1.8% per year (95% confidence interval [CI] 1.5%-2.1%) overall, while RCC incidence attributable to overweight/obesity increased 3.8% per year (95%CI 3.5%-4.2%) and RCC incidence unrelated to overweight/obesity increased 1.2% per year (95% CI 0.9%-1.4%). In conclusion, overweight/obesity appears to have contributed importantly to the rising incidence of RCC in the United States since the mid-1990s. Public health interventions focused on reducing overweight and obesity could help substantially in curbing this trend.  相似文献   
2.
目的 了解上海市普陀区青少年超重、肥胖和高血压的流行病学资料,探讨青少年超重、肥胖与高血压的关系。方法 以普陀区3 662名初中学生为研究对象,测量身高、体重、腰围、血压。依据我国青少年性别、年龄百分位标准判断超重、肥胖,高血压前期和高血压。比较不同性别青少年超重、肥胖率以及正常体重、超重、肥胖组的高血压前期、高血压检出率。结果 超重、肥胖检出率分别为19.88%、13.49%,男生超重22.56%、肥胖18.29%检出率明显高于女生17.07%,8.45%(P<0.01)。收缩压、舒张压比较肥胖组高于超重组和正常体重组,超重组高于正常体重组(P<0.01)。高血压和高血压前期的检出率比较肥胖组高于超重组和正常体重组,超重组高于正常体重组(P<0.01)。结论 普陀区青少年超重及肥胖发生率高于全国平均水平,高血压的发生与超重、肥胖相关。青少年肥胖的防治工作应引起重视。  相似文献   
3.
Background and AimsAtherosclerosis begins early in life, thus optimal cardiovascular health needs to be promoted early. We investigated whether appetitive behaviors among 7 year olds are associated with their cardiometabolic health years later.Methods and ResultsA sample of 2951 children from a Portuguese birth cohort was analyzed. The Children's Eating Behavior Questionnaire assessed eating behaviors, and a measure of cardiometabolic risk (higher risk group: those in the upper quartile of triglycerides, homeostatic model assessment-insulin resistance, waist circumference and systolic blood pressure and in the lower quartile of high-density lipoprotein cholesterol z-scores) was created. Linear and logistic regressions were run. Children with more food avoidant behaviors had lower cardiometabolic risk (Satiety Responsiveness – boys: OR = 0.39, 95% CI 0.16; 0.93, girls: OR=0.37, 95% CI 0.17; 0.82 and Slowness in eating – boys: OR = 0.49, 95% CI 0.25; 0.95, girls: OR = 0.49, 95% CI 0.27; 0.91). Food approach behaviors (Food responsiveness (CEBQ-FR), Enjoyment of food (CEBQ-EF) and Emotional overeating (CEBQ-EOE)) increased cardiometabolic risks (e.g. CEBQ-FR: boys: OR = 2.50, 95% CI 1.45; 4.32, girls: OR = 2.33, 95% CI 1.46; 3.71). CEBQ-EF had stronger effects in boys, while CEBQ-EOE was positively associated with cardiometabolic risk among girls. When adjusting for BMIz at 7y, associations did not remain significant. Appetitive behaviors were also associated with isolated cardiometabolic parameters; the strongest association being with waist circumference.ConclusionsAppetitive behaviors at 7-years are associated with cardiometabolic risk at age 10. While ‘food avoidant’ behaviors protect against cardiometabolic risk and ‘food approach’ behaviors increase cardiometabolic risk, these associations are largely dependent of child's adiposity.  相似文献   
4.
ABSTRACT

Objective(s): The prevalence of adolescent obesity is high among the various ethnic groups native to the Pacific region (European, Melanesian and Polynesian). An important factor of weight gain or loss is body size satisfaction; however, little is known about adolescent body self-perception in the Pacific region.

Design: Body dissatisfaction was evaluated using the Stunkard Figure Rating Scale in a sample of 699 adolescents from rural and urban areas of New Caledonia. The socio-demographic factors associated with higher body dissatisfaction were determined by multiple linear regression modeling.

Results: Our results showed a high rate of body dissatisfaction (over 70%) in the adolescents. Body dissatisfaction was strongly related to the body mass index z-score. Melanesians boys had higher body dissatisfaction scores when they felt ‘too thin’ while Melanesian girls showed lower body dissatisfaction when they felt ‘too fat.’.

Conclusion: These results showed that social pressure for thinness or musculature may be different among adolescents living in New Caledonia. These results should be taken into account in education overweight prevention programs.  相似文献   
5.
目的探讨基于静息能量消耗(REE)计算每日总能量消耗(TEE),对孕前超重/肥胖的妊娠期糖尿病(GDM)孕妇血糖管理意义。 方法选择2018年6月至2019年6月,于首都医科大学附属北京潞河医院产科"糖尿病一日门诊"就诊时,被诊断为孕前超重/肥胖的67例GDM孕妇为研究对象。按照其首次就诊时间的奇、偶周,将其分为研究组(n=34,首次就诊时间为奇数周者)和对照组(n=33,首次就诊时间为偶数周者)。采用成组t检验对2组孕妇年龄、孕次、孕期体重增加值、新生儿出生体重、空腹血糖、餐后2 h血糖等进行统计学分析。采用Mann-Whitney U检验对2组孕妇分娩孕龄、产次等进行统计学分析。采用χ2检验、Fisher确切概率法、连续性校正χ2检验对2组孕妇尿酮体阳性率、巨大儿发生率等进行统计学分析。本研究经首都医科大学附属北京潞河医院医学伦理委员审核批准(审批文号:2018-LHKY-027-02),并与所有受试者签署知情同意书。 结果①2组GDM孕妇年龄、孕次、产次、分娩孕龄及孕前人体质量指数(BMI)构成比比较,差异均无统计学意义(P>0.05)。②研究组孕妇TEE为(1 532.6±301.9)kcal/d,显著低于对照组的(1 824.1±313.2) kcal/d,并且差异有统计学意义(t=3.311、P=0.002);2组孕妇血糖达标情况构成比比较,差异亦有统计学意义(P=0.040)。③研究组孕妇孕期体重增加值、糖化血红蛋白(HbA1c)水平和新生儿出生体重分别为(13.4±6.2)kg、(5.6±0.3)%和(3 287.5±577.1)g,明显低于对照组的(18.2±4.8)kg、(6.2±0.2)%和(3 632.8±490.6)g,并且差异均有统计学意义(t=2.235、P=0.031,t=2.882、P=0.047,t=2.121、P=0.039)。 结论基于REE估算的TEE,较通用系数法估算的TEE,更接近于孕前超重/肥胖GDM孕妇的实际能量需求。因此,基于REE估算的TEE更有利于对孕前超重/肥胖的GDM进行孕期血糖管理。  相似文献   
6.
7.
8.
To evaluate the anthropometric indexes in subjects with varicocele compared to controls and the incidence of varicocele in different body mass index (BMI) groups for the purpose of exploring the association between varicocele and anthropometric indexes. A comprehensive literature search was conducted by using PubMed, MEDLINE, EMBASE databases and Cochrane Library up to February 2019. A systematic review and meta‐analysis was conducted by STATA, and Newcastle–Ottawa Scale was utilised for assessing risk of bias. Ultimately, 13 articles containing seven case–control studies and six cross‐sectional studies with 1,385,630 subjects were involved in our study. Pooled results demonstrated that varicocele patients had a lower BMI (WMD = ?0.77, 95% CI = ?1.03 to ?0.51) and a higher height than nonvaricocele participants, especially in grade 3 varicocele patients. Subgroup analyses showed that normal BMI individuals had a higher risk of varicocele than obese or overweight individuals and a lower risk than underweight individuals. In conclusion, this study indicates that varicocele patients have a lower BMI and a higher height than nonvaricocele participants. Moreover, men with excess bodyweight have a lower incidence of varicocele compared to normal weight or underweight people. That is to say, high BMI and adiposity protect against varicocele and high BMI is associated with a decreased risk of varicocele.  相似文献   
9.
10.
ObjectiveObesity has reached epidemic proportions in the US. Physical activity is an important component of obesity reduction, but little is known about contemporary exercise levels among overweight/obese American adults. In this study, we compared current physical activity levels in overweight and obese US adults to those of normal weight individuals as well as ascertained which sociodemographic factors influence the meeting of physical activity recommendations in these three groups.MethodsWe used national data from 2015 and 2017 Behavioral Risk Factor Surveillance System surveys (n = 726,075). Bivariate analyses were conducted to determine unadjusted physical activity levels in normal weight, overweight, and obese adults. We fit multinomial logistic models to identify associations between sociodemographic factors and meeting physical activity recommendations in our study population.ResultsAround 45% of overweight and 57% of obese adults failed to meet physical activity guidelines compared to 41% of normal weight adults. Age, sex, and race were significantly associated with physical activity levels for both overweight and obese adults. In overweight and obese individuals, associations between sociodemographic factors and physical activity were more similar between the two comparisons of insufficiently active (IA) versus active (A)/highly active (HA) and A versus HA but quite different to those in the inactive (IN) versus IA/A/HA comparison.ConclusionsFuture physical activity interventions should be aimed at increasing the number of overweight and obese US adults who meet physical activity guidelines as well as targeted towards specific sociodemographic groups within the overweight/obese population with low exercise levels.  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