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A thorough understanding of the factors that regulate the secretion of FSH is critical for the development of efficient methods for fertility regulation. The purpose of this review is to evaluate what is currently known about the existence of FSH-releasing factor(s). It considers the obstacles encountered in understanding the control of FSH secretion, current knowledge of the nature of FSH secretion and the mechanisms involved in controlling FSH secretion, the arguments that have been posed against the need for an FSH-releasing factor and finally the evidence available to date supporting the existence of FSH-releasing factor(s).  相似文献   

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Antioxidants, preferentially those of dietary origin, have for a long time been considered to help against diseases that are presumably aggravated by oxidative stress, such as cardiovascular diseases, cancer, and neurodegenerative disorders. The outcome of clinical trials undertaken to corroborate this hypothesis, however, remained largely inconclusive. Evidence is now emerging that some dietary "antioxidants" influence signaling pathways and the expression of genes relevant in atherosclerosis by mechanisms other than antioxidative ones. By concrete examples we show that (1) vitamin E has gene regulatory functions which might be more important than acting as an antioxidant in vivo, (2) selenium itself is not an antioxidant at all, and even not in general when incorporated into glutathione peroxidases, and (3) a moderate oxidative stress is beneficial rather than detrimental since it can induce defense mechanisms counteracting xenobiotic and oxidative stress. Thus, there is only a future for antioxidants in the prevention of any disease if their real mechanism of action is considered and suitable read-outs and biomarkers are established.  相似文献   

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The present study aims to compare the phenolic and hydrophilic antioxidant profiles of organically and conventionally produced tomato juices. Comparisons of analyses of archived samples from conventional and organic production systems demonstrated statistically higher levels (P < 0.05) of phenolic compounds in organic tomato juices. This increase corresponds not only with increasing amounts of soil organic matter accumulating in organic plots but also with reduced manure application rates once soils in the organic systems had reached equilibrium levels of organic matter. Using principal component analysis, results show that phenolic compounds and hydrophilic antioxidant capacity were responsible for the differentiation between organic and conventional tomato juices. Thus, there appear to be genuine differences in the bioactive components of organic and conventional tomato juices not previously reported.  相似文献   

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Food selection at a particular occasion is guided by properties of the food itself (sensory or intrinsic properties), but also by the information provided with the food, for example, packaging information (extrinsic properties). We compared preference responses of 71 consumers with a considerable type 2 diabetes risk, who had undergone nutrition counseling in a prevention program, in sensory assessments and product evaluation integrated into Adaptive Conjoint Analysis with the response of a healthy control group (n = 101). Vanilla yogurt, varied in composition (fat content, sugar content, flavor intensity) and packaging information (fat content, sugar content, flavor intensity), was used as stimulus material. Both groups of consumers preferred yogurt with a higher fat content on the basis of sensory evaluation, but rejected products with a higher fat content (10 g/100 g) when this information was available on the package. The degree of rejection was significantly higher for the high risk group. Whereas both groups preferred reduced-sugar yogurt on the basis of declaration, preferences towards the less sweet product were only observed for the high risk group.  相似文献   

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Beer contains low‐molecular‐weight β‐linked oligosaccharides that originate from the degradation of β‐glucan in the barley cell wall during malting and mashing. Over 90% of these oligosaccharides contain three or four glucosyl units. They remain intact through a static oral, gastric and small intestinal in vitro human digestive system model, indicating that they should be available to beneficial organisms known to be present in the human large intestine. Several intestine‐associated Lactobacillus strains were shown to be capable of growth on these β‐linked oligosaccharides, thereby leading us to tentatively propose that these compounds may represent prebiotics. Copyright © 2017 The Institute of Brewing & Distilling  相似文献   

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Although research is shedding new light on the phenomenon, it is proving difficult to manage.  相似文献   

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Corporate social responsibility and the tobacco industry: hope or hype?   总被引:1,自引:3,他引:1  
Corporate social responsibility (CSR) emerged from a realisation among transnational corporations of the need to account for and redress their adverse impact on society: specifically, on human rights, labour practices, and the environment. Two transnational tobacco companies have recently adopted CSR: Philip Morris, and British American Tobacco. This report explains the origins and theory behind CSR; examines internal company documents from Philip Morris showing the company's deliberations on the matter, and the company's perspective on its own behaviour; and reflects on whether marketing tobacco is antithetical to social responsibility.  相似文献   

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PurposeThis study aims to investigate the association of compliance amongst lens wearers and lens case contamination as assessed by the microbial profile of lens cases.MethodsFifty-two asymptomatic lens wearers filled out questionnaires seeking demographic data and several aspects of compliance to lens wear. Subsequently, contamination profiles of the inside bottom and rim of their lens cases was obtained for bacteria, fungi and Acanthamoeba. The association of the self-reported responses in the questionnaire with contamination profile of the lens case was then analyzed.ResultsBased on compliance criteria, 21% of the participants were described as fully compliant lens wearers. Contamination of lens case was prevalent in 42% of the cases. Frequent non-compliant behaviours reported by study participants included, showering and sleeping with contact lenses, and irregular lens case replacement. In comparison to soft contact lens wearers prevalence of non-compliance and contamination amongst rigid gas permeable (RGP) lens wearers was significantly greater. There was a statistically significant correlation between bacterial contamination and current case age.ConclusionThese results suggest that majority of lens wearers do not fully comply with recommendations for lens wear and case care. Crucially, none of the fully compliant patients had contaminated lens cases. However it would appear that several non-compliant behaviours significantly increase the risks of case contamination. These results suggest that greater efforts should be invested with lens wearers to ensure enhanced compliance as this is likely to reduce the possibility of case contamination.  相似文献   

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Sebranek JG  Bacus JN 《Meat science》2007,77(1):136-147
The growing popularity of food products marketed in the United States as "natural" and "organic" has resulted in a proliferation of marketing efforts to meet consumer demands for these foods. Because natural and organic foods are not permitted to use chemical preservatives, the traditional curing agents used for cured meats, nitrate and/or nitrite, cannot be added to natural and organic processed meat products. However, alternative processes that utilize ingredients with high nitrate content, such as vegetable-based ingredients, and a nitrate-reducing starter culture can produce processed meats with very typical cured meat properties. Because it is not possible to analytically measure the amount of nitrite produced by this process, several potential issues deserve consideration. Regulations, for example, should permit labeling that accurately reflects the process and products, manufacturing procedures must be standardized to achieve product consistency, marketing efforts should clearly communicate the nature of these products to consumers, product quality must be maintained, and microbiological safety must be assured.  相似文献   

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