1,720,963 research outputs found
Does sensitive skin lie in epidermal barrier impairment or abnormalities? Results from an observational study assessing biophysical parameters
No full textBACKGROUND: The pathophysiology of sensitive skin is largely unknown and no univocal data on the role of the epidermal barrier impairment have been identified. The aim of this study was to assess whether subjects with or without sensitive skin differ for some biophysical skin parameters, which reflect skin barrier integrity or skin hyperactivity. METHODS: This observational, cross-sectional study included adult volunteers not affected with chronic inflammatory skin diseases who attended the Unit of Dermatology and the Center of Cosmetology of the University of Ferrara, Ferrara, Italy, between March 2021 and November 2022. All subjects, subdivided into those with or without sensitive skin, based on either Lactic Acid Stinging Test (LAST) result or a questionnaire -based skin sensitivity score 24, were tested for transepidermal water loss (TEWL), skin elasticity and hydrations and dermographism. RESULTS: One hundred and eighty-seven subjects were included. No significant differences in terms of TEWL, elasticity and hydration levels were recorded between subjects with sensitive skin and those without, subdivided according to both the LAST result and the questionnaire score. Dermographism was elicited more in subjects with sensitive skin than in the others, although without statistical significance. CONCLUSIONS: The study failed to find significant biophysical differences between sensitive and non -sensitive skin. Therefore, the role of skin barrier impairment does not appear to be a necessary condition in determining an abnormal skin sensitivity to potentially unpleasant and irritating stimuli. These findings indirectly support the relevance of a peripheral sensory neural hyperactivity in the pathophysiology of sensitive skin
Spongosome-based co-delivery of curcumin and Piperine: A novel strategy for mitigating pollution-induced skin damage
Full text linkThe present study aims to explore the potential role of curcumin and piperine loaded spongosomes to protect the skin against pollution-induced damage. The hydration of a glyceryl monooleate and sodium cholate thin film, followed by homogenization, led to dispersions with an internal spongiform structure, as demonstrated by cryogenic transmission electron microscopy and small angle X-ray scattering. Spongosome mean diameter measured by photon correlation spectroscopy was roughly 200 nm. Curcumin and piperine were efficiently encapsulated in spongosomes, as demonstrated by ultrafiltration and HPLC analysis. In vitro permeation tests revealed that piperine enhances the penetration of curcumin, suggesting a further improved bioavailability and sustained release. Ex vivo studies using human skin biopsies showed that curcumin and piperine-loaded spongosomes protect the skin against diesel exhaust emissions, preserving the levels of key skin barrier proteins, as filaggrin and involucrin. The formulations exhibited non-irritating properties in human patch tests, supporting their suitability for topical application
Proposal of a self‐assessment questionnaire for the diagnosis of sensitive skin
No full textBACKGROUND: Sensitive skin is very common and distressing. Its diagnosis may be difficult with the tools/methods available at the moment. AIMS: To assess the reliability of a self‐assessment questionnaire for the diagnosis of sensitive skin, using the results of lactic acid stinging test (LAST) as a reference for the identification of subjects suffering from this condition. A further objective was to identify the questionnaire cutoff score that better discriminates between subjects with or without sensitive skin. PATIENTS/METHODS: Among the adult volunteers included in this observational, cross‐sectional study, both LAST‐positive subjects, who were considered as having sensitive skin (“patients”), and negative ones (“controls”) completed the questionnaire. It consisted of a part for self‐assessing and quantifying (0–10) sensitive skin and another one that included 10 items, each referring to a specific, potentially triggering stimulus. A cumulative score (questionnaire‐based skin sensitivity score, 0–10) was calculated from the sum of all items considered capable of triggering unpleasant skin sensations in real‐life experience. RESULTS: One hundred and sixty‐two subjects were enrolled, 102 patients and 60 controls; 98 subjects thought they had sensitive skin. The mean questionnaire‐based skin sensitivity score was significantly higher among patients than controls and correlated with skin sensitivity self‐assessments. A cutoff value of 3 was set for the identification of LAST‐positive subjects, with 79% accuracy. CONCLUSIONS: The study self‐assessment questionnaire seems to be a reliable tool for diagnosing sensitive skin in clinical practice. These results led us to identify a numerical cutoff for detecting propensity to experience sensitive skin
Results from an extended study on the reliability of a questionnaire for the diagnosis of sensitive skin: Confirmations and improvements
No full textObjectiveA recently proposed self-assessment questionnaire aimed at diagnosing sensitive skin provided promising results in a relatively small population. The main objectives were: (i) to assess the reliability of the aforementioned questionnaire in a larger population and verify the cut-off score previously found to predict skin sensitivity (defined as positivity to LAST, lactic acid stinging test) and (ii) to define a formula that yields the probability of a positive LAST result. MethodsAdult volunteers were included in this observational, cross-sectional, extended study. Both LAST-positive subjects, who were considered as having sensitive skin ('patients') and negative ones ('controls') completed the questionnaire, which concerned sensitivity to possible triggers of unpleasant skin sensations in real life. A cumulative score (questionnaire-based skin sensitivity score, 0-10) was calculated from the sum of all items. ResultsThree hundred and sixty-four subjects were enrolled, 214 patients and 150 controls. The mean questionnaire-based skin sensitivity score was significantly higher among patients than controls. Using two different methods, cut-off values of 4 and 5 were defined for the identification of LAST-positive subjects, with 76.6% and 72.8% accuracy, respectively. Scores below 4 or above 5 showed a high (80% or better) negative or positive predictive value, respectively. The coefficients found that in multivariate analysis for each questionnaire item, gender and age allowed us to calculate the probability of LAST positivity with higher precision taking into account the 'relative weight' of each factor. ConclusionWith small variations in the results, the self-assessment questionnaire confirmed its reliability for diagnosing sensitive skin in clinical practice
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Production and Characterization of Semi-Solid Formulations for the Delivery of the Cosmetic Peptide Palmitoyl-GHK
No full textIn this study, vesicular lipid systems and semi-solid formulations for the skin application of Palmitoyl-GHK were formulated and characterized. Palmitoyl-GHK is a cosmetic peptide with anti-aging action, capable of treating the signs of skin aging by mainly stimulating collagen synthesis in the dermis. The so-called “ethosomes” were evaluated as nanovesicular systems constituted of phosphatidylcholine, organized in vesicles, ethanol, and water. In addition, semi-solid systems were produced and characterized, namely an organogel based on phosphatidylcholine, isopropyl palmitate, and water, a gel based on Poloxamer 407, and the poloxamer organogel, created by combining organogel and Poloxamer gel. To make the ethosomal dispersions suitable for skin application, xanthan gum was added as a gelling agent. Studies were therefore carried out on semi-solid formulations to determine (i) the spreadability, a key factor that influences various aspects of a topical/transdermal formulation, (ii) the occlusive factor, important to guarantee good effectiveness of a dermocosmetic product, and finally, (iii) the hydrating power, to study the effect of a formulation applied to the skin. A formulation study enabled the selection of the most suitable formulations for the incorporation of the active ingredient of interest. Palmitoyl-GHK was found to be soluble both in ethosomes and in the poloxamer organogel. In vitro studies were therefore conducted to evaluate the release kinetics of Palmitoyl-GHK from the formulations, via Franz cells. The qualitative–quantitative analysis, through analytical HPLC, highlighted that the active ingredient is released more slowly from semi-solid formulations compared to vesicular systems; in particular, the presence of poloxamer allows a controlled release of the peptide. Further studies will be necessary to verify the anti-aging efficacy of formulations containing the peptide
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