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91.
G. Pennick B. Chavan B. Summers A. V. Rawlings 《International journal of cosmetic science》2012,34(6):567-574
Humectant and occlusive technologies have traditionally been used for the treatment of dry skin. Originally, non‐lamellar‐forming ingredients were used such as petrolatum but recent research has shown the advantage of using lamellar‐forming ingredients such as ceramides, pseudoceramides and phospholipids in the relief of dry skin. Nevertheless, the importance of using lipid‐phase transition inducers, such as long‐chain fatty acids, has not been studied clinically. The evaluation of a novel complex of lipophilic ingredients was of interest: cetyl alcohol, isostearyl isostearate, potassium cetyl phosphate, cetyl behenate and behenic acid. The combination of all these ingredients was shown to be more effective than any single component in water vapour transmission rate studies. This was thought to be owing to the formation of a unique structural organization of the lipids upon dry‐down from an O/W emulsion as was examined by X‐ray diffraction and optical microscopy. When evaluated clinically in a randomized double‐blind and vehicle‐controlled moisturization efficacy trial, this novel blend of ingredients was shown to not only improve the visible signs of skin dryness to a significantly greater extent than a comparable mineral oil‐containing vehicle but also then maintain a better skin condition during the regression no‐treatment phase of the study. This combination of ingredients offers a new technology option for the treatment of dry skin. 相似文献
92.
93.
Daniel Campos Frederic Bartumeus Vicen? Méndez Xavier Espadaler 《Journal of the Royal Society Interface》2014,11(90)
We study central-place foraging patterns of Aphaenogaster senilis ants at a population level by video framing individual ant trajectories in a circular arena with a nest connected to its centre. The ants naturally leave and enter the nest and forage generating non-trivial movement patterns around the nest. Our data analysis indicated that the trajectories observed can be classified into two strategies: the risk-averse strategy, which involves wandering around the nest without departing far from it and the risk-prone strategy, which involves long exploration paths with periodic returns to the central region, nearby the nest. We found that both risk-prone and risk-averse strategies exhibit qualitatively the same reorientation patterns, with the time between consecutive reorientations covering a wide range of scales, and fitting a stretched exponential function. Nevertheless, differences in the temporal scales and the time variability of such reorientation events differ, together with other aspects of motion, such as average speed and turns. Our results give experimental evidence that the internal mechanisms driving reorientations in ants tend to favour frequently long relocations, as theory predicts for efficient exploration in patchy landscapes, but ants engaged in central-place foraging can modulate such behaviour to control distances from the nest. Previous works on the species support the idea that risk-prone and risk-averse strategies may reflect actual differences between individuals age and experience; these factors (age and experience) should be then relevant in modulating the internal reorientation clocks. To support the validity of our findings, we develop a random-walk model combining stretched exponential reorientation clocks with klinokinesis that fits the time length and the travelled distance distributions of the observed trajectories. 相似文献
94.
S.D. Supekar A.F. Clarens D.A. Stephenson S.J. Skerlos 《Journal of Materials Processing Technology》2012,212(12):2652-2658
This paper investigates the cooling and lubrication properties of supercritical carbon dioxide (scCO2) sprays as potential substitutes for aqueous emulsions and straight oils used in the metalworking industry today. Sprays of rapidly expanding scCO2 act to cool and lubricate machining and forming processes by delivering a mixture of dry ice and lubricant deep into the cutting/forming zone. In this work, experiments with turning, milling, drilling, thread cutting, and thread forming were performed with scCO2 and other metalworking fluids (MWFs) to evaluate their relative performance with respect to tool wear and machining torque. Observations reveal that scCO2–MWFs are more effective in removing heat from the tool-workpiece interface than conventionally delivered (flood) aqueous MWFs as well as other gas-based MWF sprays. In addition, scCO2–MWFs delivered in lubricant-expanded phase, where scCO2 is used to increase volume of lubricant in the spray field, are shown to provide better lubricity than straight oils and oil-in-air minimum quantity lubrication (MQL) sprays. As a result, scCO2–MWFs can reduce tool wear and improve machining productivity in a wide range of manufacturing operations leading to appreciable improvements in the economics of manufacturing. Also given that CO2 is a recovered waste gas that is non-toxic, scCO2–MWFs can improve the environmental and worker health performance of manufacturing operations. 相似文献
95.
Yi-Ming Zhao Shikha Ojha Catherine M. Burgess Da-Wen Sun Brijesh K. Tiwari 《International Journal of Food Science & Technology》2021,56(2):721-732
This study aimed to evaluate the influence of plasma treatment time, bacterial exposure time to PAW and bacterial species on the inactivation efficacy of plasma-activated water (PAW), with additional investigation of the inactivation mechanisms of PAW. Six bacterial species, including Listeria innocua, Staphyloccus aureus, Escherichia coli, Pseudomonas fluorescens, Shewanella putrefaciens and Aeromonas hydrophila were selected as the representative bacteria. The initial bacterial concentration was around 7 log CFU ml−1 after mixing with PAW, and the inactivation efficacy was measured after different exposure times during the 4 °C storage. Scanning electron microscopy (SEM) images of the bacteria after PAW treatment were carried out to inspect the cell structure damage, and physicochemical properties of PAW, including pH, conductivity and long-living reactive species of H2O2, , and , were examined. The results showed that the inactivation efficacy of PAW was positively correlated with plasma treatment time and bacterial exposure time, and for the species examined in this study, the Gram-negative species were more sensitive to PAW than the Gram-positive species. Cell structure damage, including shrinkage, distortion, or holes, was observed after PAW treatment. The pH of PAW was acidified to 2.5–2.9, and conductivity was significantly increased to 518.0 μs cm−1. and H2O2 were reduced during the 48 h storage, while an increased concentration was observed for . This study demonstrated that the processing parameters of plasma treatment time, exposure time and characteristics of bacteria can significantly affect the inactivation efficacy of PAW. 相似文献
96.
Between 1954 and 1996, more than 200 nuclear power projects were publicly announced in the USA. Barely half of these projects were completed and generated power commercially. Existing research has highlighted a number of potential explanations for the varying siting outcomes of these projects, including contentious political protests, socioeconomic and political conditions within potential host communities, regulatory changes (‘ratcheting’), and cost overruns. However, questions remain about which of these factors, if any, had an impact on these outcomes. This article uses a new data set of 228 host communities where siting was attempted to illuminate the factors that led projects towards either completion or cancelation. Controlling for factors highlighted by past studies, we find that regulatory, site‐ and reactor‐specific factors predict the outcomes of attempts to site nuclear reactors over this time period. These findings have important implications in the post‐Fukushima ‘nuclear renaissance’ era when many still hope to revitalize the nuclear industry in the USA. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
97.
BackgroundCancer is a group of diseases involving an abnormal growth of cells which tend to proliferate in an uncontrolled fashion and in some cases metastasize to the surrounding tissues (malignancy). Resistance to chemotherapy is typically intrinsic (heterogeneity); however, acquired resistance has also become prevelant due to multiple factors including expression of energy-dependent transporters causing expulsion of internalized drug contents extracellular, insensitivity of tumor cells to drug-induced apoptosis, and induction of drug-detoxifying mechanisms. Curcumin (CUR) has gained widespread recognition due to remarkable anticancer, anti-mutagenic, and anti-metastasizing potentials via downregulation of proliferation of cancer cells and induction of apoptosis. Nevertheless, pharmaceutical significance and therapeutic feasibility of CUR is restricted due to intrinsic physicochemical characteristics including poor aqueous solubility, inadequate biological stability, low bioavailability, and short half-life.Scope and approachOwing to these pharmaceutical limitations of CUR, nanodelivery systems have attained remarkable fascination in the recent years. Therefore, this review was aimed to overview and critically ponders recent developments in improving anticancer viability of CUR.Key findings and conclusionCritical analysis of the literature revealed that nanodelivery systems showed promising efficiency in achieving tumor specific targetability, maximizing internalization of drugs into cancer cells, mitigating tumor metastasis, as well as improving anticancer efficacy of CUR. Moreover, nanocarrier-mediated improved pharmacokinetics, drug accumulation, induced promising cytotoxicity, and enhanced anticancer efficacy by suppressing Egr-1 induction, Mitogen-activated protein kinase (MAPK) pathway, and protein tyrosine kinase (PTK) cascades while mitigating the progression of tumor, have also been discussed. 相似文献
98.
99.
Flame retardancy,antifungal efficacies,and physical–mechanical properties for wood/polymer composites containing zinc borate
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Tanakit Chan‐Hom Weawboon Yamsaengsung Benjaphorn Prapagdee Teerasak Markpin Narongrit Sombatsompop 《火与材料》2017,41(6):675-687
This work aimed to examine flame retardancy, antifungal performance and physical–mechanical properties for silane‐treated wood–polymer composites (WPCs) containing zinc borate (ZnB). ZnB with content from 0.0 to 7.0 wt% was added to WPCs, and silane‐treated wood contents were varied. The polymers used were poly(vinyl chloride) (PVC) and high‐density polyethylene (HDPE). The decay test was performed according to the European standard EN 113. Loweporus sp., a white‐rot fungus, was used for antifungal performance evaluation. Antifungal performance was observed to decrease with wood content. Incorporation of ZnB at 1.0 wt% significantly increased the antifungal performance of WPCs. ZnB content of greater than 1.0 wt% lowered the antifungal properties of WPCs. The results suggested that the wood/PVC composite exhibited better antifungal performance than the wood/HDPE composite. The addition of wood flour to PVC and HDPE decreased flame retardancy, whereas the incorporation of ZnB retained the flame retardancy. ZnB was found to be more appropriate for wood/PVC than wood/HDPE as a result of hydrogen chloride generated from the dehydrochlorination reaction of PVC. The results indicated that the addition of ZnB did not affect the physical‐mechanical properties of neat polymers and the composites. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
100.
Alexandre J. Kabla 《Journal of the Royal Society Interface》2012,9(77):3268-3278
A number of biological processes, such as embryo development, cancer metastasis or wound healing, rely on cells moving in concert. The mechanisms leading to the emergence of coordinated motion remain however largely unexplored. Although biomolecular signalling is known to be involved in most occurrences of collective migration, the role of physical and mechanical interactions has only been recently investigated. In this study, a versatile framework for cell motility is implemented in silico in order to study the minimal requirements for the coordination of a group of epithelial cells. We find that cell motility and cell–cell mechanical interactions are sufficient to generate a broad array of behaviours commonly observed in vitro and in vivo. Cell streaming, sheet migration and susceptibility to leader cells are examples of behaviours spontaneously emerging from these simple assumptions, which might explain why collective effects are so ubiquitous in nature. The size of the population and its confinement appear, in particular, to play an important role in the coordination process. In all cases, the complex response of the population can be predicted from the knowledge of the correlation length of the velocity field measured in the bulk of the epithelial layer. This analysis provides also new insights into cancer metastasis and cell sorting, suggesting, in particular, that collective invasion might result from an emerging coordination in a system where single cells are mechanically unable to invade. 相似文献