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21.
Scope: Health benefits of prebiotic administration have been judged mainly from the increased numbers of bifidobacteria and the enhanced production of short‐chain fatty acids in the colon. Only a few studies have focused on the capacity of prebiotics to decrease the proteolytic fermentation, which might contribute to health as well. Methods and results: The influence of the prebiotic oligofructose‐enriched inulin (OF‐IN) on the pattern of volatile organic compounds was characterized using an in vitro faecal model. Faecal slurries, obtained from healthy subjects, were anaerobically incubated at 37°C with and without different doses of OF‐IN (2.5, 5, 10, or 20 mg) and changes in the metabolite pattern and pH were evaluated. A total of 107 different volatile organic compounds were identified and classified according to their chemical classes. The concentration of esters and acids significantly increased with increasing doses of OF‐IN. Similar effects were observed for some aldehydes. To the contrary, OF‐IN dose‐dependently inhibited the formation of S‐compounds. Also, the generation of other protein fermentation metabolites such as phenolic compounds was inhibited in the presence of OF‐IN. Conclusion: Our results confirmed a clear dose‐dependent stimulation of saccharolytic fermentation. Importantly, a significant decrease in toxic protein fermentation metabolites such as sulphides attended these effects.  相似文献   
22.
The absence of longitudinal data about correlates of physical activity during adolescence has hindered the identification of key mediator variables that can be targeted by interventions. Building on the authors' previous report of a cross-sectional analysis, this study compared barriers self-efficacy and perceived behavioral control as predictors of change in 2 levels of physical activity across a 1-year period among a sample of Black and White adolescent girls (N = 1,038). Self-efficacy did not predict change in either moderate or vigorous physical activity. In contrast, perceived behavioral control exhibited a longitudinal, independent relationship with change in vigorous physical activity. The authors concluded that perceived behavioral control is an independent predictor of change in vigorous physical activity levels across a 1-year period among a sample of Black and White adolescent girls and warrants study as a potential mediator variable in interventions designed to increase or maintain physical activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
23.

Cancer therapy for both central nervous system (CNS) and non-CNS tumors has been previously associated with transient and long-term cognitive deterioration, commonly referred to as ‘chemo fog’. This therapy-related damage to otherwise normal-appearing brain tissue is reported using post-mortem neuropathological analysis. Although the literature on monitoring therapy effects on structural magnetic resonance imaging (MRI) is well established, such macroscopic structural changes appear relatively late and irreversible. Early quantitative MRI biomarkers of therapy-induced damage would potentially permit taking these treatment side effects into account, paving the way towards a more personalized treatment planning.

This systematic review (PROSPERO number 224196) provides an overview of quantitative tomographic imaging methods, potentially identifying the adverse side effects of cancer therapy in normal-appearing brain tissue. Seventy studies were obtained from the MEDLINE and Web of Science databases. Studies reporting changes in normal-appearing brain tissue using MRI, PET, or SPECT quantitative biomarkers, related to radio-, chemo-, immuno-, or hormone therapy for any kind of solid, cystic, or liquid tumor were included. The main findings of the reviewed studies were summarized, providing also the risk of bias of each study assessed using a modified QUADAS-2 tool. For each imaging method, this review provides the methodological background, and the benefits and shortcomings of each method from the imaging perspective. Finally, a set of recommendations is proposed to support future research.

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The present investigation addressed three questions: (i) Does the obese syndrome alter the fatty acid composition of cardiac tissue and membrane phospholipids in obese (fa/fa) rats? (ii) Are changes, if they occur, similar to those reported for tissues of the genetically obese (ob/ob) mouse? (iii) Can cardiac tissue phospholipids and their component fatty acids be modified by dietary lipids and if so does this occur to the same extent in both fa/fa and lean (Fa/?) rats? Proportions of polyunsaturated fatty acids (PUFA) in cardiac total phospholipids of fa/fa rats differed significantly from those of Fa/? rats and from those reported for ob/ob mice. Increased 18∶2n?6 and decreased 20∶4n?6 and 22∶6n?3 in fa/fa rats indicated impaired PUFA metabolism, possibly reduced Δ6 and/or Δ5 desaturase activity, compared with Fa/? rats. No differences in hepatic Δ6 and Δ5 desaturase activity between fa/fa and Fa/? were found but enhanced activity of Δ9 desaturase activity in fa/fa as compared to Fa/? was evident. Inclusion of sunflower oil (SO) or triolein (TO) at 5% and 20% by weight in the diet elicited marked changes in the fatty acyl composition of cardiac phospholipids in both fa/fa and Fa/? rats when compared with animals fed the control Oxoid diet alone. Supplementation with triolein was most effective, reducing 18∶2n?6 and increasing 20∶4n?6 proportions in fa/fa rats so that they resembled those in Fa/? rats fed the control Oxoid diet. The type of fat rather than the amount of its dietary intake appears to be the main determinant of the observed changes in phospholipid composition. Pair feeding hyperphagic fa/fa rats to the lower intakes of Fa/? rats did not abolish the characteristic differences in the proportions of PUFA in cardiac phospholipids between the two phenotypes. The effect of triolein on cardiac phospholipid fatty acid composition in the present studies is intriguing and may be relevant in understanding the beneficial role of dietary olive oil in ameliorating cardiovascular disease in man.  相似文献   
26.
To compare the spontaneous cocoa bean fermentation process carried out in different cocoa-producing regions, heap and box (one Ivorian farm) and box (two Brazilian farms) fermentations were carried out. All fermentations were studied through a multiphasic approach. In general, the temperature inside the fermenting mass increased throughout all fermentations and reached end-values of 42-48 °C. The main end-products of pulp carbohydrate catabolism were ethanol, lactic acid, acetic acid, and/or mannitol. In the case of the fermentations on the selected Ivorian farm, the species diversity of lactic acid bacteria (LAB) and acetic acid bacteria (AAB) was restricted. Lactobacillus fermentum and Leuconostoc pseudomesenteroides were the predominant LAB species, due to their ethanol and acid tolerance and citrate consumption. The levels of mannitol, ascribed to growth of L. fermentum, were fermentation-dependent. Also, enterobacterial species, such as Erwinia soli and Pantoea sp., were among the predominating microbiota during the early stages of both heap and box fermentations in Ivory Coast, which could be responsible for gluconic acid production. Consumption of gluconic acid at the initial phases of the Ivorian fermentations could be due to yeast growth. A wider microbial species diversity throughout the fermentation process was seen in the case of the box fermentations on the selected Brazilian farms, which differed, amongst other factors, regarding pod/bean selection on these farms as compared to fermentations on the selected Ivorian farm. This microbiota included Lactobacillus plantarum, Lactobacillus durianis, L. fermentum, Lactobacillus mali, Lactobacillus nagelii, L. pseudomesenteroides, and Pediococcus acidilactici, as well as Bacillus subtilis that was present at late fermentation, when the temperature inside the fermenting mass reached values higher than 50 °C. Moreover, AAB seemed to dominate the Brazilian box fermentations studied, explaining higher acetic acid concentrations in the pulp and the beans. To conclude, it turned out that the species diversity and community dynamics, influenced by local operational practices, in particular pod/bean selection, impact the quality of fermented cocoa beans.  相似文献   
27.
如果您的网络工程团队已决定实施可重新配置的光分插多路复用器(ROADM)基础设施,那么现在需要做些什么?在项目从技术调查到现场试验再到最终部署的过程中,哪些问题会不期而遇?您正在创建将多个环折叠在一起的网络拓扑,这种基础设施将在多大程度上影响您的故障诊断能力?  相似文献   
28.
Models of self-regulated learning and of children's coping both consider help-seeking an adaptive response to academic problems, yet students do not always seek help when it is needed, and help-seeking generally declines across early adolescence. A study of 765 children in elementary and middle school (Grades 3-6) during fall and spring of the same school year investigated whether motivational resources predicted help-seeking and whether losses in motivational supports across the middle school transition mirrored age declines. As predicted, 3 motivational self-perceptions were tightly correlated with coping in fall and spring; relatedness was the primary predictor of increases in help-seeking, whereas a sense of incompetence predicted increases in concealment. Teacher reports of motivational support also predicted changes in student coping and were mediated by children's self-perceptions. Analyses of reciprocal effects of students' help-seeking and concealment on changes in teacher support corroborated hypothesized cycles in which motivationally "rich" children, by constructively seeking help, become "richer," whereas motivationally "poor" children, by concealing their difficulties, become "poorer." Age differences in children's motivational resources across the transition to middle school paralleled age differences in help-seeking and concealment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
29.
Data from 943 undergraduates and 54 teachers show that an advance organizer significantly increased student comprehension but had negative affective consequences. A program title also inhibited the more advanced students' perceptions of the personal value and relevance of the instructional material. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
30.
Environmental management systems (EMSs) are growing in popularity as tools to manage corporate environmental issues. Despite widespread use, existing frameworks for EMSs may not provide organizations with the knowledge needed for decision-making. Through a synthesis of case studies and workshops, we suggest five elements for EMSs to be expanded for organizational decision-making. The five elements are process diagrams, long- and short-term goals linked to strategy, reliable information systems, risk assessment tools, and collaboration of environmental personnel across the organization. These five elements provide decision makers with relevant information linked to business strategy so that the organization can improve performance. The elements can be integrated with an existing EMS or used as a foundation for implementing one.  相似文献   
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