975 resultados para Skin temperature
Resumo:
Compromised skin integrity of farmed Atlantic salmon, commonly occurring under low temperature and stressful conditions, has major impacts on animal welfare and economic productivity. Even fish with minimal scale loss and minor wounds can suffer from secondary infections, causing downgrading and mortalities. Wound healing is a complex process, where water temperature and nutrition play key roles. In this study, Atlantic salmon (260 g) were held at different water temperatures (4 or 12 °C) and fed three different diets for 10 weeks, before artificial wounds were inflicted and the wound healing process monitored for 2 weeks. The fish were fed either a control diet, a diet supplemented with zinc (Zn) or a diet containing a combination of functional ingredients in addition to Zn. The effect of diet was assessed through subjective and quantitative skin histology and the transcription of skin-associated chemokines. Histology confirmed that wound healing was faster at 12 °C. The epidermis was more organised, and image analyses of digitised skin slides showed that fish fed diets with added Zn had a significantly larger area of the epidermis covered by mucous cells in the deeper layers after 2 weeks, representing more advanced healing progression. Constitutive levels of the newly described chemokines, herein named CK 11A, B and C, confirmed their preferential expression in skin compared to other tissues. Contrasting modulation profiles at 4 and 12 °C were seen for all three chemokines during the wound healing time course, while the Zn-supplemented diets significantly increased the expression of CK 11A and B during the first 24 h of the healing phase.
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Physical activity for pregnant women should be controlled and adapted in order to minimize the risk of loss of balance and fetal trauma (Davies, Wolfe, Mottola, y MacKinnon, 2003). Noninvasive technologies are required for understanding better the effects of physical activity on pregnant women. Infrared thermography allows, remotely, securely and without any contact, to measure and display accurate temperatures on the human skin.
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The photoproduction of vitamin D in the skin was essential for the evolutionary development of terrestrial vertebrates. During exposure to sunlight, previtamin D3 formed in the skin is isomerized to vitamin D3 (calciol) by a temperature-dependent process. Since early land vertebrates were poikilothermic, the relatively slow conversion of previtamin D3 to vitamin D3 at ambient temperature put them at serious risk for developing vitamin D deficiency, thus leading to a poorly mineralized skeleton that could have ultimately halted further evolutionary development of vertebrates on land. We evaluated the rate of isomerization of previtamin D3 to vitamin D3 in the skin of iguanas and found the isomerization rate was enhanced by 1100% and 1700% at 25 degrees C and 5 degrees C, respectively. It is likely that the membrane entrapment of previtamin D3 in its s-cis,s-cis conformation is responsible for the markedly enhanced conversion of previtamin D3 to vitamin D3. The membrane-enhanced production of vitamin D3 ensures the critical supply of vitamin D3 to poikilothermic animals such as iguanas.
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The effects of temperature and salinity on the embryonation period and hatching success of eggs of Benedenia seriolae were investigated. Temperature strongly influenced embryonation period; eggs first hatched 5 days after laying at 28 degreesC and 16 days after laying at 14 degreesC. The relationship between temperature and embryonation period is described by quadratic regression equations for time to first and last hatching. Hatching success was >70% for B. seriolae eggs incubated at temperatures from 14 to 28 degreesC. However, no B. seriolae eggs embryonated and hatched at 30 degreesC and
Resumo:
Background The 2001 Australian census revealed that adults aged 65 years and over constituted 12.6% of the population, up from 12.1% in 1996. It is projected that this figure will rise to 21% or 5.1 million Australians by 2031. In 1998, 6% (134 000) of adults in Australia aged 65 years and over were residing in nursing homes or hostels and this number is also expected to rise. As skin ages, there is a decreased turnover and replacement of epidermal skin cells, a thinning subcutaneous fat layer and a reduced production of protective oils. These changes can affect the normal functions of the skin such as its role as a barrier to irritants and pathogens, temperature and water regulation. Generally, placement in a long-term care facility indicates an inability of the older person to perform all of the activities of daily living such as skin care. Therefore, skin care management protocols should be available to reduce the likelihood of skin irritation and breakdown and ultimately promote comfort of the older person. Objectives The objective of this review was to determine the best available evidence for the effectiveness and safety of topical skin care regimens for older adults residing in long-term aged care facilities. The primary outcome was the incidence of adverse skin conditions with patient satisfaction considered as a secondary outcome. Search strategy A literature search was performed using the following databases: PubMed (NLM) (1966–4/2003), Embase (1966–4/2003), CINAHL (1966–4/2003), Current Contents (1993–4/2003), Cochrane Library (1966–2/2003), Web of Science (1995–12/2002), Science Citation Index Expanded and ProceedingsFirst (1993–12/2002). Health Technology Assessment websites were also searched. No language restrictions were applied. Selection criteria Systematic reviews of randomised controlled trials, randomised and non-randomised controlled trials evaluating any non-medical intervention or program that aimed to maintain or improve the integrity of skin in older adults were considered for inclusion. Participants were 65 years of age or over and residing in an aged care facility, hospital or long-term care in the community. Studies were excluded if they evaluated pressure-relieving techniques for the prevention of skin breakdown. Data collection and analysis Two independent reviewers assessed study eligibility for inclusion. Study design and quality were tabulated and relative risks, odds ratios, mean differences and associated 95% confidence intervals were calculated from individual comparative studies containing count data. Results The resulting evidence of the effectiveness of topical skin care interventions was variable and dependent upon the skin condition outcome being assessed. The strongest evidence for maintenance of skin condition in incontinent patients found that disposable bodyworn incontinence protection reduced the odds of deterioration of skin condition compared with non-disposable bodyworns. The best evidence for non-pressure relieving topical skin care interventions on pressure sore formation found the no-rinse cleanser Clinisan to be more effective than soap and water at maintaining healthy skin (no ulcers) in elderly incontinent patients in long-term care. The quality of studies examining the effectiveness of topical skin care interventions on the incidence of skin tears was very poor and inconclusive. Topical skin care for prevention of dermatitis found that Sudocrem could reduce the redness of skin compared with zinc cream if applied regularly after each pad change, but not the number of lesions. Topical skin care on dry skin found the Bag Bath/Travel Bath no-rinse skin care cleanser to be more effective at preventing overall skin dryness and most specifically flaking and scaling when compared with the traditional soap and water washing method in residents of a long-term care facility. Information on the safety of topical skin care interventions is lacking. Therefore, because of the lack of evidence, no recommendation on the safety on any intervention included in this review can be made.
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The literature relating to evaporation from single droplets of pure liquids, and to the drying of droplets containing solids and of droplet sprays has been reviewed. The heat and mass transfer rates for a single droplet suspended from a nozzle were studied within a 42mm I.D. horizontal wind tunnel designed to supply hot dry air, to simulate conditions encountered in a practical spray dryer. A novel rotating glass nozzle was developed to facilitate direct measurements of droplet weight and core temperature. This design minimised heat conduction through the nozzle. Revised correlations were obtained for heat and mass transfer coefficients, for evaporation from pure water droplets suspended from a rotating nozzle. Nu = 2.0 + 0.27 (l/B)°-18Re°-5Pr°-83 Sh = 2.0 + 0.575 ((T0-T.)/Tomfc) -o.o4Reo.5 ^0.33 Experimental drying studies were carried out on single droplets of different types of skin-forming materials, namely, custard, gelatin, skim milk and fructose at air temperatures ranging from 19°C to 198°C. Dried crusts were recovered and examined by Scanning Electron Microscopy. Skin-forming materials were classified into three types according to the mechanisms of skin formation. In the first type (typified by droplets of custard and starch) skin formed due to gelatinisation at high temperatures. Increasing the drying temperature resulted in increased crust resistance to mass transfer due to increased granule swelling and the crust resistance was completely transferred to a skin resistance at drying temperatures > 150°C. In the second type e.g. gelatin droplets the skin formed immediately drying had taken place at any drying temperature. At drying temperature > 60° C a more resistant skin was formed. In the third type (typified by droplets of skim milk and fructose) the skin appeared on the droplet surface at a certain stage of the drying process under any drying conditions. As the drying temperature was increased the resistance of the skin to mass transfer increased. The drying rate history of any material depended upon the nature of the skin formed which, in turn, depended upon the drying conditions. A mathematical model was proposed for the drying of the first type of skin-forming material. This was based on the assumption that, once all the granules gelatinised at the gelatinisation temperature, a skin appeared instantaneously on the droplet surface. The experimentally-observed times at which the skin appeared on the droplets surfaces were in excellent agreement with those predicted from the model. The work should assist in understanding the fundamentals of paniculate drying processes, particularly when skin-formation occurs and may be a crucial factor in volatiles retention.
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Purpose: To formulate stable water in oil (W/O) emulsion containing hydroalcoholic crude extract of Ziziphus mauritiana leaves for skin rejuvenation. Methods: Placebo (base) without any plant extract and formulation with 4 % Ziziphus mauritiana extract were prepared by mixing. Samples of the emulsions were subjected to varying storage conditions, i.e., 8, 25, 40 oC and 40 oC + 75 % relative humidity for a period of 4 weeks to predict their stability. During this period, stability parameters, including liquefaction, phase separation, color, electrical conductivity, centrifugation and pH were monitored at specified time intervals. Skin rejuvenation was evaluated using 13 healthy human volunteers over a period of 8 weeks. During this period, various skin parameters such as erythema, melanin level, moisture content, elasticity and sebum content of the skin were evaluated at specified intervals. Results: Both the active formulation and placebo were stable in terms of liquifaction, phase separation and color at all the storage conditions of temperature and humidity. Active formulation showed statistically significant (p < 0.05) improvement in skin melanin as well as in skin moisture and sebum levels, whereas these properties were reduced or even absent in the placebo formulation (p > 0.05). Both active and placebo formulations changed skin elasticity and erythema significantly (p < 0.05). Conclusion: It is evident from the findings that the leaf extract of Ziziphus mauritiana possesses antiaging properties as well as exert skin lightening, moisturizing and viscoelastic effects on human skin.
Resumo:
A low temperature synthesis method based on the decomposition of urea at 90°C in water has been developed to synthesise fraipontite. This material is characterised by a basal reflection 001 at 7.44 Å. The trioctahedral nature of the fraipontite is shown by the presence of a 06l band around 1.54 Å, while a minor band around 1.51 Å indicates some cation ordering between Zn and Al resulting in Al-rich areas with a more dioctahedral nature. TEM and IR indicate that no separate kaolinite phase is present. An increase in the Al content however, did result in the formation of some SiO2 in the form of quartz. Minor impurities of carbonate salts were observed during the synthesis caused by to the formation of CO32- during the decomposition of urea.