2,489 research outputs found

    Mutagenic and/or carcinogenic compounds in meat and meat products: Heterocyclic aromatic amines perspective

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    Meat and meat products, which have a very important place in terms of nutrition, can endanger human health if they are not properly prepared and preserved. Meat and meat products except for products such as sushi, which are deliberately consumed raw, are generally consumed immediately after cooking. Cooking done properly gives meat and meat products their unique taste and aroma, increases their digestibility and makes them microbiologically safe. However, some harmful food toxicants can occur during the cooking process. Heterocyclic aromatic amines can be formed during cooking of the proteinaceous foods such as meat and meat products. Epidemiological studies have proved that heterocyclic aromatic amines are mutagenic and/or carcinogenic compounds. Therefore, having sufficient knowledge about heterocyclic aromatic amines will help to reduce the health risk posed by these com  pounds. In this context, in the present study, basic information about heterocyclic aromatic amines that can be formed during the heat treatment of meat and meat products was reviewed.Meat and meat products, which have a very important place in terms of nutrition, can endanger human health if they are not properly prepared and preserved. Meat and meat products except for products such as sushi, which are deliberately consumed raw, are generally consumed immediately after cooking. Cooking done properly gives meat and meat products their unique taste and aroma, increases their digestibility and makes them microbiologically safe. However, some harmful food toxicants can occur during the cooking process. Heterocyclic aromatic amines can be formed during cooking of the proteinaceous foods such as meat and meat products. Epidemiological studies have proved that heterocyclic aromatic amines are mutagenic and/or carcinogenic compounds. Therefore, having sufficient knowledge about heterocyclic aromatic amines will help to reduce the health risk posed by these com  pounds. In this context, in the present study, basic information about heterocyclic aromatic amines that can be formed during the heat treatment of meat and meat products was reviewed.

    Dioxins and dioxin-like compounds in meat and meat products

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    Dioxin and dioxin-like compounds are persistent organic pollutants that received considerable attention in recent years due to their high potential toxicity, wide distribution and extreme stability. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) mainly occur in the environment as a result of several human activities including combustion, incineration and many other industrial activities, whereas polychlorinated biphenyls (PCBs) congeners were intentionally manufactured and widely used in various fields. Since dioxin and dioxin-like compounds are found in various environmental compartments (air, water, soil, sludge, sediment, food, feed, blood, animal and human tissues), humans could be exposed to them via inhalation, dermal contact or food ingestion. However, 90% of human exposure to dioxin is through food ingestion particularly foods from animals and foods that are rich in fat. In contrast, only low levels have been found in food items of plant origin. Exposure to dioxin compounds is associated with various adverse health problems. However, their toxicity varies dramatically according to the type of dioxin, species of exposed organism, as well as exposure frequency and duration. Dioxins are mainly determined by instrumental chromatographic methods such as GC-HRMS and GC–MS/MS. Many efforts have been made to remove, reduce and prevent these hazardous substances from the environment. However, the best method for reducing human exposure to dioxins and dioxin-like compounds is controlling and minimizing their production. In this article, structures, sources, exposure, toxicity and analysis methods of dioxin and dioxin-like compounds in meat and other foods were reviewed.Dioxin and dioxin-like compounds are persistent organic pollutants that received considerable attention in recent years due to their high potential toxicity, wide distribution and extreme stability. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) mainly occur in the environment as a result of several human activities including combustion, incineration and many other industrial activities, whereas polychlorinated biphenyls (PCBs) congeners were intentionally manufactured and widely used in various fields. Since dioxin and dioxin-like compounds are found in various environmental compartments (air, water, soil, sludge, sediment, food, feed, blood, animal and human tissues), humans could be exposed to them via inhalation, dermal contact or food ingestion. However, 90% of human exposure to dioxin is through food ingestion particularly foods from animals and foods that are rich in fat. In contrast, only low levels have been found in food items of plant origin. Exposure to dioxin compounds is associated with various adverse health problems. However, their toxicity varies dramatically according to the type of dioxin, species of exposed organism, as well as exposure frequency and duration. Dioxins are mainly determined by instrumental chromatographic methods such as GC-HRMS and GC–MS/MS. Many efforts have been made to remove, reduce and prevent these hazardous substances from the environment. However, the best method for reducing human exposure to dioxins and dioxin-like compounds is controlling and minimizing their production. In this article, structures, sources, exposure, toxicity and analysis methods of dioxin and dioxin-like compounds in meat and other foods were reviewed

    Mutagenic and/or carcinogenic compounds in meat and meat products: polycyclic aromatic hydrocarbons perspective

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    Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants posing a great risk to human health due to their mutagenic and/or carcinogenic properties. They are produced from incomplete combustion of a heat source, pyrolysis of organic components, and fat-induced flame formation. Meat and meat products are one of the major sources of PAH exposure. Since PAH intake increases the risk of cancer, understanding the factors affecting PAH formation in meat and meat products is very important within the scope of PAH exposure reduction strategies. In this study, the features and formation of PAHs, the factors affecting the formation of PAH compounds and their reduction/inhibition pathways were reviewed in order to provide a perspective on the presence of PAHs in meat and meat products

    A Welfare Analysis of Spectrum Allocation Policies

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    Analysis of spectrum allocation policies in the economics literature focuses on competitive bidding for wireless licenses. Auctions generating high bids, as in Germany and the UK, are identified as "successful," while those producing lower receipts, as in Switzerland and the Netherlands, are deemed "fiascoes." Yet, even full and costless extraction of license rents does not map directly to social welfare, because spectrum policies creating rents impose social costs. For example, rules favoring monopoly market structure predictably increase license values, but reduce welfare. This paper attempts to shift analytical focus to the relationship between spectrum policy (including license auctions) and efficiency in output markets. In cross-country comparisons of performance metrics in mobile telephone service markets, empirical estimates suggest that countries that auction licenses do not achieve lower prices or higher levels of output than other nations. Rather, countries allocating greater bandwidth to licensed operators and achieving more competitive market structures realize demonstrable social welfare benefits. These gains generally dominate efficiencies associated with license sales. Policies to increase auction revenues, such as reservation prices and subsidies for weak bidders, should be evaluated in this light.

    Damage mode identification in transverse crack tension specimens using acoustic emission and correlation with finite element progressive damage model

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    © 2018 Elsevier Ltd In this study, damage progression in unidirectional composite specimens is investigated. Transverse Crack Tension specimens are used to stimulate damage in a predetermined progressive sequence. Acoustic Emission (AE) registration technique and its location detection capability is used to identify and locate the damage modes during the tension tests. The k-means++ algorithm is applied to cluster similar AE events and obtain reliable correlations between the damage modes and AE characteristics. Damage modes at the end of interrupted tests are identified under an optical microscope and correlated with locations of AE clusters. It is seen that matrix cracks have high amplitude and duration, whereas delaminations have low amplitude and mid-duration, and fibre breaks have high average frequency characteristics. A finite element analysis was performed to predict the progressive failure behaviour including intralaminar failure and delaminations. The correlations between the AE clusters and damage modes are validated with the finite element model

    Do high frequency acoustic emission events always represent fibre failure in CFRP laminates?

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    © 2017 Elsevier Ltd When damage in carbon fibre reinforced composites (CFRP) is monitored by acoustic emission (AE), it is a common belief that high frequency AE events originate from fibre failure. This shows that this statement may not correspond to the reality, and matrix cracks can emit high frequency AE signals. Quasi-static tension of [−45 2 /0 2 /+45 2 /90 2 ] s laminates was monitored by AE, Digital Image Correlation (DIC) on the surface of the sample and in-situ optical microscopy on the sample's polished edge. Unsupervised k-means clustering algorithm was applied to the AE results. By comparison with the direct DIC and microscopic observations, the AE cluster with high frequency and low amplitude was found to correspond to directly observed matrix cracks

    Dioxins and dioxin-like compounds in meat and meat products

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    Dioxin and dioxin-like compounds are persistent organic pollutants that received considerable attention in recent years due to their high potential toxicity, wide distribution and extreme stability. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) mainly occur in the environment as a result of several human activities including combustion, incineration and many other industrial activities, whereas polychlorinated biphenyls (PCBs) congeners were intentionally manufactured and widely used in various fields. Since dioxin and dioxin-like compounds are found in various environmental compartments (air, water, soil, sludge, sediment, food, feed, blood, animal and human tissues), humans could be exposed to them via inhalation, dermal contact or food ingestion. However, 90% of human exposure to dioxin is through food ingestion particularly foods from animals and foods that are rich in fat. In contrast, only low levels have been found in food items of plant origin. Exposure to dioxin compounds is associated with various adverse health problems. However, their toxicity varies dramatically according to the type of dioxin, species of exposed organism, as well as exposure frequency and duration. Dioxins are mainly determined by instrumental chromatographic methods such as GC-HRMS and GC–MS/MS. Many efforts have been made to remove, reduce and prevent these hazardous substances from the environment. However, the best method for reducing human exposure to dioxins and dioxin-like compounds is controlling and minimizing their production. In this article, structures, sources, exposure, toxicity and analysis methods of dioxin and dioxin-like compounds in meat and other foods were reviewed

    What Really Matters in Spectrum Allocation Design

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    Since initiated in the U.S. in July 1994, auctions have replaced "beauty contests" in the assignment of wireless licenses in many countries. Economists have been involved in constructing the competitive bidding mechanisms chosen, and have devoted considerable analysis to the problems involved. Generally, auction methods have been evaluated according to the receipts generated; social gains resulting from the displacement of activity-distorting taxes has motivated the welfare analysis. Yet, policies widely advocated by economists to intensify license bidding , such as reservation prices or bidding credits for "weak"' bidders , may impose deadweight losses that dominate revenue raising efficiencies. Yet, retail market effects are largely excluded from cost-benefit calculations of rules to assign licenses. This paper reviews a number of case studies suggesting that economic analysis is most usefully focused on consumer welfare in wireless service markets, the outputs resulting from license use. Econometric evidence from mobile phone markets in twenty-nine countries suggests that auctions do not lower prices or increase usage, while liberalization, increased spectrum allocations and more competitive markets -- produces such pro-consumer results. We use simulations to compare the net social benefits of liberalization against policies suggested in the auction literature to enhance license bids. We argue that increases in bandwidth and competitiveness produce consumer benefits that generally dominate social gains from rent extraction via wireless license auctions.

    Breast cancer with diabetes insipidus

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    Diabetes insipidus (DI) is a rare clinical condition, which is usually caused by neurohypophyseal or pituitary stalk infiltration in cancer patients. Case report: we present a 62-year old metastatic breast cancer woman with DI. She admitted to the hospital because of nausea, vomiting, polyuria and polydipsia, while she was on no cytotoxic medication. She had no electrolyte imbalance except mild hypernatremia. The CT scan of the brain yielded a suspicious area in pituitary gland. A pituitary stalk metastasis was found on magnetic resonance imaging (MRI) of pituitary. Water deprivation test was compatible with DI. A clinical response to nasal vasopressin was achieved. Conclusions: Cancer patients who have symptoms such as nausea, vomiting, polyuria and polydipsia while they are not on chemotherapy should be evaluated for not only metabolic complications like hypercalcemia but also posterior pituitary or stalk metastasis MRI could be the choice of imaging for pituitary metastasis.Несахарный диабет (DI) — редкое клиническое состояние, вызываемое инфильтрацией нейрогипофизарной ножки или ножки гипофиза у онкологических больных. Описание случая: в исследовании рассмотрен случай выявления DI у 62-летней женщины, у которой был выявлен рак молочной железы с наличием метастазов. Она поступила в больницу с симптомами тошноты, рвоты, полиурии и полидипсии, хотя не проходила курса химиотерапии. У больной не выявлено дисбаланса электролитов, кроме небольшой гипернатриемии. Компьютерная томография мозга показала подозрительную область в мозговом придатке. На магнитно-резонансном изображении выявлен метастаз в ножке гипофиза. Обезвоживание также соответствовало диагнозу DI. Получен клинический ответ на назальный вазопрессин. Выводы: онкологические больные с симптомами тошноты, рвоты, полиурии и полидипсии, не проходящие курса химиотерапии, должны быть обследованы не только на предмет метаболических осложнений, таких как гиперкальциемия, но и на возможное наличие метастазов в ножке и задней части гипофиза с помощью магнитно-резонансного изображения. Ключевые слова: рак, несахарный диабет, метастаз в гипофизе
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