全文获取类型
收费全文 | 252篇 |
免费 | 19篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 17篇 |
妇产科学 | 6篇 |
基础医学 | 19篇 |
口腔科学 | 3篇 |
临床医学 | 16篇 |
内科学 | 38篇 |
皮肤病学 | 3篇 |
神经病学 | 18篇 |
特种医学 | 2篇 |
外科学 | 14篇 |
综合类 | 27篇 |
预防医学 | 70篇 |
药学 | 11篇 |
中国医学 | 19篇 |
肿瘤学 | 11篇 |
出版年
2023年 | 4篇 |
2022年 | 17篇 |
2021年 | 15篇 |
2020年 | 13篇 |
2019年 | 27篇 |
2018年 | 17篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 14篇 |
2014年 | 26篇 |
2013年 | 15篇 |
2012年 | 18篇 |
2011年 | 17篇 |
2010年 | 13篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1968年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 15 毫秒
1.
《Journal of the Academy of Nutrition and Dietetics》2021,121(1):112-120
BackgroundLittle is known about the diet quality of racial minority children during the summertime when school is out of session and there is risk of accelerated weight gain. Project Summer Weight and Environmental Assessment Trial was an observational, prospective study exploring child weight status and health trends during the summer.ObjectiveThe objective of this substudy of Project Summer Weight and Environmental Assessment Trial was to examine the diet quality of elementary-aged racial minority children during the summertime vs school year.DesignThis observational, prospective substudy was conducted from June to September 2017.Participants/settingStudents in prekindergarten through fifth grade were recruited from 2 schools located in low-income urban neighborhoods of Columbus, OH, with a predominantly Black population. Sixty-two children (39 families) enrolled.Main outcome measuresTwenty-four-hour dietary recalls (2 weekdays, 1 weekend day) were collected at 3 time points: (1) beginning of summer (T0); (2) midsummer (T1); and (3) beginning of subsequent school year (T2). Healthy Eating Index (HEI)-2015 total and component scores were calculated to assess diet quality. Daily calories (kilocalories) and servings of types of foods within food groups were also assessed.Statistical analysesRepeated measures analysis of variance and Tukey’s post hoc analyses were performed.ResultsRetention was 76% (n = 47). Mean age was 7.0 ± 0.3 years, 79% (n = 37) were African American, and 58% of participants (n = 26) reported annual household incomes ≤$20,000. HEI-2015 total score was significantly lower during the summertime vs school year (P = .02). HEI-2015 component score for whole fruits (P = .04) was also lower in the summer vs school year, along with total vegetables (P < .001), greens and beans (P < .001) specifically, and legumes (P < .001). The HEI-2015 component score for added sugars (P = .04) was significantly lower in the summer vs the school year as well, indicating a higher intake of added sugars during the summer. On the other hand, whole grains were higher during the summer vs school year (P < .01), specifically snack chips (P = .03) and popcorn (P < .01). Total daily calories did not differ between the summertime vs school year.ConclusionsIn a small sample of predominantly racial minority school-aged children from low-income households, child diet quality is better during the school year vs summer. Future research is needed to determine if and to what extent summer vs school year diet quality may be associated with differences in weight status. 相似文献
2.
The nucleotide sequence of the Adoxophyes orana granulovirus (AdorGV) DNA genome was determined and analysed. The genome contains 99,657 bp and has an A + T content of 65.5%. The analysis predicted 119 ORFs of 150 nucleotides or larger that showed minimal overlap. Of these putative genes, 104 (87%) were homologous to genes identified previously in other baculoviruses. The mean overall amino acid identity of AdorGV ORFs was highest with CpGV ORFs at 48%. Sixty-three ORFs were conserved among all lepidopteran baculoviruses and are considered to be common baculoviral genes. Several genes reported to have major roles in baculovirus biology were not found in the AdorGV genome. These included chitinase and cathepsin, which are involved in the liquefaction of the host, which explains why AdorGV-infected insects do not degrade in a typical manner. The AdorGV genome encoded two inhibitor of apoptosis (iap) genes iap-3 and iap-5. Among all of the granuloviruses genomes there was a very high level of gene collinearity. The genes shared by AdorGV and CpGV had exactly the same order along the genome with the exception of one gene, iap-3. The AdorGV genome did not contain typical homologous region (hr) sequences. However, it contained nine repetitive regions in the genome. 相似文献
3.
O Finnström P Otterblad Olausson G Sedin F Serenius N Svenningsen K Thiringer R Tunell G Wesström 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(10):1055-1060
A prospective national investigation comprising 633 extremely low birthweight (ELBW) infants born alive in the 2-y period 1990-1992 with a birthweight of ≤1000 g and gestational age of ≥23 completed weeks was conducted regarding neurosensory outcome and growth. Three-hundred and sixty-two (98%) surviving ELBW infants were assessed at a median age of 36 months, using a specially designed protocol. At follow-up, mean height, weight and head circumference in both boys and girls were significantly lower than the reference values. The incidence of cerebral palsy was 7% among all children and 14%, 10% and 3% in children born at 23-24, 25-26 and ≥27 gestational weeks, respectively. At least one obvious handicap was present in 14%, 9% and 3% of these three groups of children, respectively. After adjustment for gestational age, a significantly increased risk of handicap was found in children with intraventricular haemorrhage grade ≥3 and/or periventricular leucomalacia and in children with retinopathy of prematurity stage ≥3. The results show that more than 90% of ELBW children born at ≥25 completed gestational weeks were without neurosensory handicap at 36 months of corrected age. In infants born at 23-24 weeks of gestation, both survival and long-term outcome were less favourable. 相似文献
4.
不同月龄正常大鼠骨形态计量学参数动态变化的研究 总被引:3,自引:0,他引:3
目的 :探讨不同月龄正常大鼠骨形态计量学参数变化 ,为抗骨质疏松药物研究提供对照依据。方法 :4 .5月龄SD雌性大鼠 ,按体重随机分组 ,在实验的d 0 (4.5月龄 )、d 30 (5 .5月龄 )、d 75 (7月龄 )、d 14 0 (10月龄 )杀死大鼠取材 ,采用体内双荧光标记法 ,胫骨上段硬组织包埋切片及松质骨形态计量学分析 ,观察不同月龄段大鼠的骨变化情况。结果 :正常大鼠 4 .5~ 10月龄 ,骨量有一缓慢上升后下降的过程 ,但变化辐度不大 (P >0 .0 5 ) ,骨量相对稳定 ,骨形成和骨吸收有先上升后下降的变化过程 (P <0 .0 5 )。结论 :4 .5~ 10月龄的SD雌性大鼠体重和骨计量学参数变化正常 ,选择该月龄段大鼠做模型 ,研究药物对骨质疏松的防治是可行的。 相似文献
5.
ObjectivesTo investigate the possible influence of polycyclic aromatic hydrocarbons (PAHs) exposure on neurodevelopment of toddlers at the age of 12 months.MethodsTotally 306 subjects were recruited from the Qingdao Birth Cohort established in 2014. PAH-DNA adducts in toddlers’ umbilical cord blood samples, hydroxyl-PAH metabolites in their urine samples and the developmental quotients (DQs) were measured. Sex, gestational age, birth weight, and maternal educational background were adjusted to analyze the influence of the PAH exposure on the neurodevelopment of the toddlers using multivariate linear regression model.ResultsPearson correlation test showed that the logarithmic values of hydroxyl-PAH were negatively correlated with the DQs. Multivariate linear regression analysis indicated that logarithmic concentration of 1(9)- hydroxyphenanthrene was still associated with the DQs of the fine motor behaviors with β and 95% confidential interval (CI) of -1.137 (-2.053, -0.222), together with PAH-DNA adducts [β (95% CI): -0.577 (-0.930, -0.225)]. PAH-DNA adducts presented an independently negative influence on the DQs of the gross motor and personal social behaviors with β (95%CI) of -0.470 (-0.814, -0.126) and -0.526 (-0.859, -0.193), respectively.ConclusionsThe exposure to PAHs in toddlers at 12 months could influence their neurodevelopment. Additionally, prenatal exposure to PAHs should also be considered. 相似文献
6.
汪诚信 《中华卫生杀虫药械》2012,(4):274-276,279
本文介绍了深圳市举行的第26届世界大学生夏季运动会病媒生物防治工作的具体做法,以及取得的丰富经验。 相似文献
7.
Christopher E. Kline Lora E. Burke Susan M. Sereika Christopher C. Imes Bonny Rockette-Wagner Dara D. Mendez Patrick J. Strollo Yaguang Zheng Stephen L. Rathbun Eileen R. Chasens 《Mayo Clinic proceedings. Mayo Clinic》2018,93(9):1290-1298
Objective
To examine the bidirectional relationship between weight change and obstructive sleep apnea (OSA) in the context of a behavioral weight loss intervention.Patients and Methods
Adults who were overweight or obese (N=114) participated in a 12-month behavioral weight loss intervention from April 17, 2012, through February 9, 2015. The apnea-hypopnea index (AHI), a marker of the presence and severity of OSA, was assessed at baseline, 6 months, and 12 months. Linear mixed models evaluated the effect of weight change on the AHI and the effect of OSA (AHI ≥5) on subsequent weight loss. Secondary analyses evaluated the effect of OSA on intervention attendance, meeting daily calorie goals, and accelerometer-measured physical activity.Results
At baseline, 51.8% of the sample (n=59) had OSA. Adults who achieved at least 5% weight loss had an AHI reduction that was 2.1±0.9 (adjusted mean ± SE) events/h greater than those with less than 5% weight loss (P<.05). Adults with OSA lost a mean ± SE of 2.2%±0.9% less weight during the subsequent 6-month interval compared with those without OSA (P=.02). Those with OSA were less adherent to daily calorie goals (mean ± SE: 25.2%±3.3% vs 34.8%±3.4% of days; P=.006) and had a smaller increase in daily activity (mean ± SE: 378.3±353.7 vs 1060.1±377.8 steps/d; P<.05) over 12 months than those without OSA.Conclusion
Behaviorally induced weight loss in overweight/obese adults was associated with significant AHI reduction. However, the presence of OSA was associated with blunted weight loss, potentially via reduced adherence to behaviors supporting weight loss. These results suggest that OSA screening before attempting weight loss may be helpful to identify who may benefit from additional behavioral counseling. 相似文献8.
目的探讨12月龄足月小样儿神经发育和气质特点,为早期干预提供理论依据。方法采用0~6岁发育筛查测验DST和1~3岁儿童气质量表,对58例12月龄足月小样儿和80例正常足月儿进行对照研究,比较两组发育商(DQ)、智力指数MI和在运动、社会适应、智力能区及气质维度和分型的差异。结果 1)足月小样儿组DQ值可疑的婴儿比例高于正常足月儿组(P0.05),DQ值中等的婴儿比例、智力能区、MI均值低于正常足月儿组(P0.05)。2)足月小样儿组的中间偏易养型构成比低于正常足月儿组(P0.05),足月小样儿组的活动水平维度得分低于正常足月儿组,规律性、趋避性维度得分高于正常足月儿组(P0.05)。结论 12月龄足月小样儿神经发育落后于正常足月儿,有独特的气质特点,应及早干预。 相似文献
9.
10.
《Journal of the American College of Radiology》2015,12(3):228-234
The current initiative to reform health care from both a quality and a cost perspective has already had a profound impact on the radiology enterprise. We have seen a decrease in the utilization of imaging studies, a reduction in reimbursement, a declining payer mix, shrinking incomes, a proliferation of performance indices, creation of radiology mega-groups, growth of national radiology companies, and increasing turf incursions. Our cheese is clearly on the move, and we must take action to reengineer the radiology enterprise. In keeping with general health care reform, we must be patient-centric, data driven, and outcome based. We must create a radiology enterprise that adheres to the value equation of providing the highest quality health care, for the lowest possible cost, for all citizens. 相似文献