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   203篇
  免费   16篇
  2021年   5篇
  2020年   3篇
  2019年   3篇
  2018年   4篇
  2017年   4篇
  2016年   9篇
  2015年   7篇
  2014年   14篇
  2013年   4篇
  2012年   14篇
  2011年   10篇
  2010年   3篇
  2009年   2篇
  2008年   6篇
  2007年   10篇
  2006年   4篇
  2005年   7篇
  2004年   8篇
  2003年   5篇
  2002年   10篇
  2001年   3篇
  1999年   3篇
  1997年   2篇
  1996年   3篇
  1995年   5篇
  1994年   2篇
  1992年   2篇
  1991年   4篇
  1990年   3篇
  1989年   3篇
  1988年   2篇
  1985年   3篇
  1984年   4篇
  1982年   3篇
  1981年   3篇
  1980年   2篇
  1974年   4篇
  1972年   2篇
  1971年   2篇
  1970年   1篇
  1969年   5篇
  1968年   2篇
  1967年   3篇
  1966年   8篇
  1965年   1篇
  1964年   1篇
  1954年   1篇
  1951年   1篇
  1930年   1篇
  1920年   2篇
排序方式: 共有219条查询结果,搜索用时 171 毫秒
61.
62.
High fat, low carbohydrate diets have become popular, as short-term studies show that such diets are effective for reducing body weight, and lowering the risk of diabetes and cardiovascular disease. There is growing evidence from both humans and other animals that diet affects behaviour and intake of fat has been linked, positively and negatively, with traits such as exploration, social interaction, anxiety and fear. Animal models with high translational value can help provide relevant and important information in elucidating potential effects of high fat, low carbohydrate diets on human behaviour. Twenty four young, male Göttingen minipigs were fed either a high fat/cholesterol, low carbohydrate diet or a low fat, high carbohydrate/sucrose diet in contrast to a standard low fat, high carbohydrate minipig diet. Spontaneous behaviour was observed through video recordings of home pens and test-related behaviours were recorded during tests involving animal-human contact and reaction towards a novel object. We showed that the minipigs fed a high fat/cholesterol, low carbohydrate diet were less aggressive, showed more non-agonistic social contact and had fewer and less severe skin lesions and were less fearful of a novel object than minipigs fed low fat, high carbohydrate diets. These results found in a porcine model could have important implications for general health and wellbeing of humans and show the potential for using dietary manipulations to reduce aggression in human society.  相似文献   
63.
The International Journal of Life Cycle Assessment - In life-cycle assessment (LCA), environmental technologies are often modelled as “black-box processes”, where inputs and outputs are...  相似文献   
64.
Consumption of industrially produced trans fatty acids (IP-TFA) has been positively associated with systemic markers of low-grade inflammation and endothelial dysfunction in cross-sectional studies, but results from intervention studies are inconclusive. Therefore, we conducted a 16 week double-blind parallel intervention study with the objective to examine the effect of IP-TFA intake on biomarkers of inflammation, oxidative stress, and endothelial dysfunction. Fifty-two healthy overweight postmenopausal women (49 completers) were randomly assigned to receive either partially hydrogenated soybean oil (15.7 g/day IP-TFA) or control oil without IP-TFA. After 16 weeks, IP-TFA intake increased baseline-adjusted serum tumor necrosis factor (TNF) α by 12% [95% confidence interval (CI): 5-20; P = 0.002] more in the IP-TFA group compared with controls. Plasma soluble TNF receptors 1 and 2 were also increased by IP-TFA [155 pg/ml (CI: 63-247); P < 0.001 and 480 pg/ml (CI: 72-887); P = 0.02, respectively]. Serum C-reactive protein, interleukin (IL) 6 and adiponectin and subcutaneous abdominal adipose tissue mRNA expression of IL6, IL8, TNFα, and adiponectin as well as ceramide content were not affected by IP-TFA, nor was urinary 8-iso-prostaglandin-F(2α). In conclusion, this dietary trial indicates that the mechanisms linking dietary IP-TFA to cardiovascular disease may involve activation of the TNFα system.  相似文献   
65.
66.

Background

As cardio-metabolic risk tracks from childhood to adulthood, a better understanding of the relationship between movement behaviors (physical activity, sedentary behavior and sleep) and cardio-metabolic risk in childhood may aid in preventing metabolic syndrome (MetS) in adulthood.

Objective

To examine independent and combined cross-sectional and longitudinal associations between movement behaviors and the MetS score in 8-11 year old Danish children.

Design

Physical activity, sedentary time and sleep duration (seven days and eight nights) were assessed by accelerometer and fat mass index (fat mass/height2) was assessed using Dual-energy X-ray absorptiometry. The MetS-score was based on z-scores of waist circumference, mean arterial blood pressure, homeostatic model assessment of insulin resistance, triglycerides and high density lipoprotein cholesterol. All measurements were taken at three time points separated by 100 days. Average of the three measurements was used as habitual behavior in the cross-sectional analysis and changes from first to third measurement was used in the longitudinal analysis.

Results

723 children were included. In the cross-sectional analysis, physical activity was negatively associated with the MetS-score (P<0.03). In the longitudinal analysis, low physical activity and high sedentary time were associated with an increased MetS-score (all P<0.005); however, after mutual adjustments for movement behaviors, physical activity and sleep duration, but not sedentary time, were associated with the MetS-score (all P<0.03). Further adjusting for fat mass index while removing waist circumference from the MetS-score rendered the associations no longer statistically significant (all P>0.17). Children in the most favorable tertiles of changes in moderate-to-vigorous physical activity, sleep duration and sedentary time during the 200-day follow-up period had an improved MetS-score relative to children in the opposite tertiles (P = 0.005).

Conclusion

The present findings indicate that physical activity, sedentary time and sleep duration should all be targeted to improve cardio-metabolic risk markers in childhood; this is possibly mediated by adiposity.  相似文献   
67.

Background

Genetic predisposition to adiposity may interact with dietary protein in relation to changes of anthropometry.

Objective

To investigate the interaction between genetic predisposition to higher body mass index (BMI), waist circumference (WC) or waist-hip ratio adjusted for BMI (WHRBMI) and dietary protein in relation to subsequent change in body weight (ΔBW) or change in WC (ΔWC).

Design

Three different Danish cohorts were used. In total 7,054 individuals constituted the study population with information on diet, 50 single-nucleotide polymorphisms (SNPs) associated with BMI, WC or WHRBMI, as well as potential confounders. Mean follow-up time was ∼5 years. Four genetic predisposition-scores were based on the SNPs; a complete-score including all selected adiposity- associated SNPs, and three scores including BMI, WC or WHRBMI associated polymorphisms, respectively. The association between protein intake and ΔBW or ΔWC were examined and interactions between SNP-score and protein were investigated. Analyses were based on linear regressions using macronutrient substitution models and meta-analyses.

Results

When protein replaced carbohydrate, meta-analyses showed no associations with ΔBW (41.0 gram/y/5 energy% protein, [95% CI: −32.3; 114.3]) or ΔWC (<−0.1 mm/y/5 energy % protein, [−1.1; 1.1]). Similarly, there were no interactions for any SNP-scores and protein for either ΔBW (complete SNP-score: 1.8 gram/y/5 energy% protein/risk allele, [−7.0; 10.6]) or ΔWC (complete SNP-score: <0.1 mm/y/5 energy% protein/risk allele, [−0.1; 0.1]). Similar results were seen when protein replaced fat.

Conclusion

This study indicates that the genetic predisposition to general and abdominal adiposity, assessed by gene-scores, does not seem to modulate the influence of dietary protein on ΔBW or ΔWC.  相似文献   
68.
69.
The pathophysiological hallmark of spotted fever group rickettsioses comprises vascular inflammation. Based on the emerging importance of the wingless (Wnt) pathways in inflammation and vascular biology, we hypothesized that Dickkopf-1 (DKK-1), as a major modulator of Wnt signaling, could be involved in the pathogenesis in rickettsial infections. Our major findings were: (i) While baseline concentration of DKK-1 in patients with R. conorii infection (n = 32) were not different from levels in controls (n = 24), DKK-1 rose significantly from presentation to first follow-up sample (median 7 days after baseline). (ii) In vitro experiments in human umbilical vein endothelial cells (HUVECs) showed that while heat-inactivated R. conorii enhanced the release of interleukin-6 (IL-6) and IL-8, it down-regulated the release of endothelial-derived DKK-1 in a time- and dose-dependent manner. (iii) Silencing of DKK-1 attenuated the release of IL-6, IL-8 and growth-related oncogene (GRO)α in R. conorii-exposed HUVECs, suggesting inflammatory effects of DKK-1. (iv) Silencing of DKK-1 attenuated the expression of tissue factor and enhanced the expression of thrombomodulin in R. conorii-exposed HUVECs suggesting pro-thrombotic effects of DKK-1. The capacity of R. conorii to down-regulate endothelial-derived DKK-1 and the ability of silencing DKK-1 to attenuate R. conorii-induced inflammation in endothelial cells could potentially reflect a novel mechanism by which R. conorii escapes the immune response at the site of infection.  相似文献   
70.
Tesofensine (TE), an inhibitor of monoamine presynaptic reuptake, has produced twice the weight loss seen with currently marketed drugs. However, its long term effect on appetite in humans has not been studied. A multicentre phase II trial was divided into two parts (24 weeks each). Part 1 had a randomized, double‐blind, placebo‐controlled design and Part 2, an open‐labeled, single‐group, uncontrolled design. A drug‐free period (12 ± 3 weeks) separated them. In Part 1, participants (n = 158) were assigned to 0.25, 0.5 or 1.0 mg TE, or placebo. Completers of Part 1 were invited to participate in Part 2 (n = 113), during which they all received 0.5 or 1.0 mg TE. Appetite sensations and a composite satiety score (CSS = satiety + fullness + (100 − hunger) + (100 − prospective food consumption) were assessed. In Part 1 TE induced a dose‐dependent increase in CSS at week 12 that correlated with weight loss during the 24 weeks (r = 0.36, P < 0.0001). However, CSS diminished over time as weight loss progressed (e.g., for 1.0 mg; 52 ± 17 mm; 64 ± 13 mm; 55 ± 13 mm at baseline, week 12 and week 24, respectively). After drug withdrawal CSS returned to baseline values (50 ± 17 mm, in the whole sample.), despite the participants' reduced‐weight state (−7.2 ± 6.7 kg, P < 0.0001). The reintroduction of TE in Part 2 increased CSS again (56 ± 17 mm at week 60), regardless of initial treatment/weight loss. We postulate that enhanced satiety is involved in early weight loss. Whether the attenuated effect on appetite seen after 24 weeks is due to a counteracting effect in the weight reduced state or whether the appetite suppressing effect of TE per se diminishes over time is, however, still unclear.  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