Influence of Mold and Heat Transfer Fluid Materials on the Temperature Distribution of Large Framed Molds in Autoclave Process

Massive composite components manufactured by autoclave curing in large framed molds are extensively used in the aerospace industry. The high temperature performance of the large framed mold is the key to achieving the desired composite part quality. This paper explores and summarizes the important thermal properties of metal and heat transfer fluid materials influencing the heating performance of large framed molds, with the aim of improving the mold temperature distribution. Considering the fluid–thermal–solid interaction inside the autoclave, a reliable computational fluid dynamics (CFD) simulation model was developed and verified by a temperature monitoring experiment to achieve the prediction of the temperature distribution of the large framed mold. Then, numerical simulations were designed on the basis of the CFD model, and the single-variable method was used to study the effects of the material thermal properties on the temperature performance of large framed molds. Our simulation predicts that when copper is used as the mold material, the temperature difference decreases by 30.63% relative to that for steel, and the heating rate increases by 3.45%. Further, when helium is used as the heat transfer medium, the temperature difference decreases by 68.27% relative to that for air, and the heating rate increases by 32.76%. This paper provides a reference for improvement of large framed mold manufacturing and autoclave process in terms of heating rate and temperature uniformity.     

Characterization of the oral fungal microbiota in smokers and non‐smokers

This study aimed to assess the effect of smoking on the biodiversity of the oral fungal microbiota of healthy young subjects, using an improved culture method that assesses both total and pathogenic viable fungi. Forty individuals (20 smokers and 20 non‐smokers) were selected. All individuals presented fungal growth (100% for molds and 92.5% for yeasts), a prevalence higher than previously reported. The most commonly occurring molds were Penicillium sp., Aspergillus sp., and Cladosporium sp. Smokers presented significantly higher levels of yeasts and pathogenic molds than did non‐smokers. No differences in fungal prevalence and diversity were observed in smokers and non‐smokers following a 30‐wk observation period. In conclusion, tobacco smoking may alter the oral mycobiota and facilitate colonization of the oral cavity with yeasts and pathogenic molds. The effect of chronic fungal colonization on the oral health of tobacco smokers cannot be neglected.     

Mycotoxins’ Toxicological Mechanisms Involving Humans,Livestock and Their Associated Health Concerns: A Review

Mycotoxins are well established toxic metabolic entities produced when fungi invade agricultural/farm produce, and this happens especially when the conditions are favourable. Exposure to mycotoxins can directly take place via the consumption of infected foods and feeds; humans can also be indirectly exposed from consuming animals fed with infected feeds. Among the hundreds of mycotoxins known to humans, around a handful have drawn the most concern because of their occurrence in food and severe effects on human health. The increasing public health importance of mycotoxins across human and livestock environments mandates the continued review of the relevant literature, especially with regard to understanding their toxicological mechanisms. In particular, our analysis of recently conducted reviews showed that the toxicological mechanisms of mycotoxins deserve additional attention to help provide enhanced understanding regarding this subject matter. For this reason, this current work reviewed the mycotoxins’ toxicological mechanisms involving humans, livestock, and their associated health concerns. In particular, we have deepened our understanding about how the mycotoxins’ toxicological mechanisms impact on the human cellular genome. Along with the significance of mycotoxin toxicities and their toxicological mechanisms, there are associated health concerns arising from exposures to these toxins, including DNA damage, kidney damage, DNA/RNA mutations, growth impairment in children, gene modifications, and immune impairment. More needs to be done to enhance the understanding regards the mechanisms underscoring the environmental implications of mycotoxins, which can be actualized via risk assessment studies into the conditions/factors facilitating mycotoxins’ toxicities.     

The role of nondermatophyte molds in onychomycosis: diagnosis and treatment

Onychomycosis is most often caused by dermatophytes. Other agents may cause onychomycosis as well, such as yeasts and nondermatophytic molds (NDMs). Historically NDMs have largely been discounted as merely contaminants, especially when a dermatophyte was present concurrently. NDMs have been shown to be sole etiologic agents, but the extent to which NDMs actually cause nail infections is uncertain. Mixed infections (NDM plus dermatophyte) occur with increasing frequency and there is considerable controversy over the role of NDMs in the presence of a dermatophyte. An isolated NDM seldom meets all the accepted criteria necessary to prove a primary infection. In addition, the criteria for demonstrating infection by an NDM have been the subject of some debate. Better, faster, and cheaper methods of identifying etiologic agents, investigations as to how to demonstrate nail invasion, and studies to determine treatment efficacy, outcome, and necessity are needed.     

Silicone plesiotherapy molds

Plesiotherapy, the treatment of superficial lesions by radioactive molds has largely been replaced by teletherapy techniques involving high energy photon and electron beams. There are, however, situations for which a short distance type treatment, in one form or another, is superior to any other presently available. Traditionally, molds have taken the form of rigid devices incorporating clamps to attach them to the patient. This ensures a reproducible geometry about a localized region since the molds are applied on a daily basis. To make such devices requires considerable skill and patience. This article describes an alternative method that eliminates the use of cumbersome devices in many situations. Silicone molds made from a plaster cast model have been found suitable for the treatment of surface lesions and especially for lesions in the oral and nasal cavities. With the use of radioactive gold seeds the molds may be left in place for a few days without fear of them moving.     

The use of thermal plastics for immobilization of patients during radiotherapy

A new orthopedic casting material has been adapted to use for immobilizing patients undergoing radiation therapy. The material has proven to be less cumbersome and time-consuming than other products currently in .use. The necessary equipment and procedures required to form a immobilization cast using thermal plastic material are described.     

Immunosuppression following dietary aflatoxin B1 exposure: a review of the existing evidence

Aflatoxin B1 is a toxic and secondary metabolite secreted by some natural molds, such as Aspergillus, and has been associated with severe toxic effects in humans and animals. They contaminate food and feed supplies, and are commonly found in grains and nuts. These toxins are synthesized under suitable physical, chemical and biological conditions. High-temperature stress, moisture stress and insect injury of the product are the most important factors in mold invasion and subsequent toxin production. These toxins have different carcinogenic and cytotoxic properties. The immunological effects of exposure to AFB1 are assessed in the present review.