21 research outputs found
Impacts of the Madden-Julian oscillation on Australian rainfall and circulation
Impacts of the Madden¿Julian oscillation (MJO) on Australian rainfall and circulation are examined during all four seasons. The authors examine circulation anomalies and a number of different rainfall metrics, each composited contemporaneously for eight MJO phases derived from the real-time multivariate MJO index. Multiple rainfall metrics are examined to allow for greater relevance of the information for applications. The greatest rainfall impact of the MJO occurs in northern Australia in (austral) summer, although in every season rainfall impacts of various magnitude are found in most locations, associated with corresponding circulation anomalies. In northern Australia in all seasons except winter, the rainfall impact is explained by the direct influence of the MJO's tropical convective anomalies, while in winter a weaker and more localized signal in northern Australia appears to result from the modulation of the trade winds as they impinge upon the eastern coasts, especially in the northeast. In extratropical Australia, on the other hand, the occurrence of enhanced (suppressed) rainfall appears to result from induced upward (downward) motion within remotely forced extratropical lows (highs), and from anomalous low-level northerly (southerly) winds that transport moisture from the tropics. Induction of extratropical rainfall anomalies by remotely forced lows and highs appears to operate mostly in winter, whereas anomalous meridional moisture transport appears to operate mainly in the summer, autumn, and to some extent in the sprin
Localization of dexamethasone within dendritic core-multishell (CMS) nanoparticles and skin penetration properties studied by multi-frequency electron paramagnetic resonance (EPR) spectroscopy
The skin and especially the stratum corneum (SC) act as a barrier and protect epidermal cells and thus the whole body against xenobiotica of the external environment. Topical skin treatment requires an efficient drug delivery system (DDS). Polymer-based nanocarriers represent novel transport vehicles for dermal application of drugs. In this study dendritic core-multishell (CMS) nanoparticles were investigated as promising candidates. CMS nanoparticles were loaded with a drug (analogue) and were applied to penetration studies of skin. We determined by dual-frequency electron paramagnetic resonance (EPR) how dexamethasone (Dx) labelled with 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (PCA) is associated with the CMS. The micro-environment of the drug loaded to CMS nanoparticles was investigated by pulsed high-field EPR at cryogenic temperature, making use of the fact that magnetic parameters (g-, A-matrices, and spin-lattice relaxation time) represent specific probes for the micro-environment. Additionally, the rotational correlation time of spin-labelled Dx was probed by continuous wave EPR at ambient temperature, which provides independent information on the drug environment. Furthermore, the penetration depth of Dx into the stratum corneum of porcine skin after different topical applications was investigated. The location of Dx in the CMS nanoparticles is revealed and the function of CMS as penetration enhancers for topical application is shown
Probabilistic forecasts of the onset of the North Australian wet season
The amount and timing of early wet-season rainfall are important for the management of many agricultural industries in north Australia. With this in mind, a wet-season onset date is defined based on the accumulation of rainfall to a predefined threshold, starting from 1 September, for each square of a 1° gridded analysis of daily rainfall across the region. Consistent with earlier studies, the interannual variability of the onset dates is shown to be well related to the immediately preceding July¿August Southern Oscillation index (SOI). Based on this relationship, a forecast method using logistic regression is developed to predict the probability that onset will occur later than the climatological mean date. This method is expanded to also predict the probabilities that onset will be later than any of a range of threshold dates around the climatological mean. When assessed using cross-validated hindcasts, the skill of the predictions exceeds that of climatological forecasts in the majority of locations in north Australia, especially in the Top End region, Cape York, and central Queensland. At times of strong anomalies in the July¿August SOI, the forecasts are reliably emphatic. Furthermore, predictions using tropical Pacific sea surface temperatures (SSTs) as the predictor are also tested. While short-lead (July¿August predictor) forecasts are more skillful using the SOI, long-lead (May¿June predictor) forecasts are more skillful using Pacific SSTs, indicative of the longer-term memory present in the ocean
Skin Disinfection by Plasma-Tissue Interaction: Comparison of the Effectivity of Tissue-Tolerable Plasma and a Standard Antiseptic
Wound healing disorders frequently occur due to biofilm formation on wound surfaces requiring conscientious wound hygiene. Often, the application of conventional liquid antiseptics is not sufficient and sustainable as (1) the borders and the surrounding of chronic wounds frequently consist of sclerotic skin, impeding an effectual penetration of these products, and (2) the hair follicles representing the reservoir for bacterial recolonization of skin surfaces are not affected. Recently, it has been reported that tissue-tolerable plasma (TTP), which is used at a temperature range between 35 and 45°C, likewise has disinfecting properties. In the present study, the effectivity of TTP and a standard liquid antiseptic was compared in vitro on porcine skin. The results revealed that TTP was able to reduce the bacterial load by 94%, although the application of the liquid antiseptic remained superior as it reduced the bacteria by almost 99%. For in vivo application, however, TTP offers several advantages. On the one hand, TTP enables the treatment of sclerotic skin as well, and on the other hand, a sustainable disinfection can be realized as, obviously, also the follicular reservoir is affected by TTP
Жанр эссе полемического характера в публицистическом дискурсе А. Андреева
The accuracy of synoptic-based weather forecasting deteriorates rapidly after five days and is not routinely available beyond 10 days. Conversely, climate forecasts are generally not feasible for periods of less than 3 months, resulting in a weather-climate gap. The tropical atmospheric phenomenon known as the Madden-Julian Oscillation (MJO) has a return interval of 30 to 80 days that might partly fill this gap. Our near-global analysis demonstrates that the MJO is a significant phenomenon that can influence daily rainfall patterns, even at higher latitudes, via teleconnections with broadscale mean sea level pressure (MSLP) patterns. These weather states provide a mechanistic basis for an MJO-based forecasting capacity that bridges the weather-climate divide. Knowledge of these tropical and extra-tropical MJO-associated weather states can significantly improve the tactical management of climate-sensitive systems such as agriculture
Influence of skin aging effects on the skin surface profile and the correlated distribution of topically applied sunscreens
The surface profile of human skin influences characteristically the distribution pattern of topically applied formulations and consequently the efficacy of sunscreens. The volumes of furrows and the spectroscopically determined factors of inhomogeneity are investigated for three sunscreens. A clear correlation between both measurands exists. The average values for younger (<32 years) and older (≥51 years) volunteers do not show statistically significant differences. Systematic variations found for the individual values are due to a reduced elasticity of the skin with age improving the homogeneity of the sunscreen distribution. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Insight into the redox status of inflammatory skin equivalents as determined by EPR spectroscopy
Atopic dermatitis (AD) is a chronic inflammatory skin disease whose pathogenesis is still not fully understood. Since inflammatory processes correlate with oxidative stress, the redox status may play a key role in AD. In this study, electron paramagnetic resonance (EPR) spectroscopy was mainly used to investigate the redox status in normal and inflammatory skin equivalents mimicking characteristics of AD in vitro using EPR spin probes (TEMPO, PCA) and a spin trap (DMPO). The total antioxidant status in the hydrophilic and lipophilic compartments of skin (microenvironment) showed no differences between the skin equivalents. In the inflammatory skin equivalents, a decreased glutathione concentration in the epidermis and an increased metabolic radical production could be observed compared to normal skin equivalents. The induction of external stress by simulated solar irradiation (UVB-NIR) resulted in the same amount and type of radicals in normal and inflammatory skin equivalents. For the first time, the antioxidant and oxidant status of inflammatory in vitro skin equivalents was analyzed by EPR to elucidate their redox status using different methods which focus on various microenvironments. Our investigations suggested that the redox status in atopic skin could be different, but this should be investigated more comprehensively, because the results can vary depending on the used methods and where the investigations take place
Methods for the evaluation of the protective efficacy of sunscreen products
The objective of the present investigation was to examine the utilization of optical and spectroscopic methods for the noninvasive characterization of Anthelios XL Fluide Extreme (SPF 50+), an exemplary sunscreen, concerning its homogeneity of distribution on the skin, its spectroscopic properties and its overall protective efficacy. The homogeneity of the distribution of the sunscreen on the skin was investigated with a multiphoton tomography microscope. Additionally, the sum transmission spectrum was determined using tape stripping and spectroscopic measurements. The results revealed a very homogeneous distribution of the sunscreen on the skin surface and also in the deep furrows. The sum transmission spectrum reflects a high protective efficacy of the sunscreen in both the UVA and UVB ranges. The sunscreen Anthelios XL Fluide Extreme (SPF 50+) generates a comfortable feeling on the skin and can be easily distributed. The presented optical methods have been shown to be suitable to investigate the overall protective efficacy of sunscreen products objectively, noninvasively and quickly. Copyright © 2012 S. Karger AG, Basel
Uptake of antioxidants by natural nutrition and supplementation: Pros and cons from the dermatological point of view
The pros and cons of the systemic and topical application of antioxidant substances are a subject of intense discussion among experts, with resulting confusion for consumers and producers. The objective of the present article is to clarify the various uncertainties relating to the use of antioxidant substances in dermatology. Whereas inappropriate application of antioxidant substances (concerning their concentration and composition) might induce harmful effects, the consumer will definitively benefit from physiological concentrations and compositions of antioxidants. The most suitable method is the consumption of natural antioxidants in the form of fruit and vegetables, for example. In addition, the skin, which also accumulates antioxidant substances, may profit from a sufficient antioxidative level, as damage induced by sun radiation in addition to skin aging is reduced. © 2011 S. Karger AG, Basel
Influence of Topical, Systemic and Combined Application of Antioxidants on the Barrier Properties of the Human Skin
Background: The formation of free radicals in human skin by solar ultraviolet radiation is considered to be the main reason for extrinsic skin aging. The antioxidants in human tissue represent an efficient protection system against the destructive action of these reactive free radicals. In this study, the parameters of the skin, epidermal thickness, stratum corneum moisture, elasticity and wrinkle volume, were determined before and after the treatment with antioxidant- or placebo-containing tablets and creams. Methods: The study included 5 groups of 15 volunteers each, who were treated for 2 months with antioxidant-containing or placebo tablets, creams or a combination of antioxidant-containing tablets and cream. The skin parameters were measured at time point 0 and at week 8 utilizing ultrasound for the determination of epidermal thickness, a corneometer for stratum corneum moisture measurements, skin profilometry for quantifying the wrinkle volume and a cutometer for determining the elasticity. Results: The verum cream had a positive influence on epidermal thickness, elasticity and skin moisture, but the verum tablets improved the epidermal thickness only. The combined application of verum tablets and creams led to a significant improvement of all investigated skin parameters, whereas the application of placebo tablets or cream did not influence any parameters. Conclusion: The topical and oral supplementation of antioxidants can be an instrument to improve several skin parameters and potentially counteract or decelerate the process of extrinsic skin aging. © 2016 S. Karger AG