1,720,968 research outputs found
Instrumental and clinical assessment of the efficacy and tolerability of a topical product with benzoyl peroxide combined with a detergent for acneic skin
No full textBackground. Benzoyl peroxide (BP) has been widely used in the therapy of acne for its antimicrobial and keratolytic properties. Data on its efficacy and observations on its irritant effects have been reported in the literature. Moreover, the use of detergents which are often associated in the treatment of acne, promotes in some cases the appearance of irritant phenomena. The aim of this study was to evaluate the efficacy and tolerability of a topical product containing benzoyl peroxide (BP), used in combination with a detergent for acneic skin, by means of clinical evaluation and instrumental methods assessing biophysical parameters. Methods. Thirty volunteers with polymorphic acne of the face were enrolled in the study. Fifteen of them used a topical gel with BP and a detergent, whereas the other 15 applied only the BP preparation for 45 days. In both groups the cutaneous biophysical parameters of hydration, pH and sebum level were investigated at three different areas (forehead, cheek and mediofacial zone). Moreover, the number and type of lesions at a selected skin area were counted and described, and the objective and subjective tolerability were assessed. Evaluations were carried out before treatment and after 20 and 45 days. Results. The total number of the acneic lesions appeared significantly decreased in all subjects, especially in those who had used the BP preparation and the detergent in combination. In both groups we observed an increase in hydration and a decrease in pH after 20 and 45 days of treatment, whereas sebum levels were unaffected. Conclusion. The results obtained confirm that BP is a valid molecule for the treatment of acne. Its use in combination with a detergent enhances its action. Moreover, no alterations of pH, hydration and sebum levels are induced by its use, and this underlines its good tolerability
Epidermal echogenicity as a hydration parameter: The effect of moisturizers on the skin as evaluated by 20 MHz B-scanning
No full textHydration of the stratum corneum after a short-term application of three skin-care products (petrolatum and two different moisturizers) was studied on the forearms of 15 healthy volunteers. Non-invasive methods were used. Evaporimetry, corneometry and B-scanning were carried our at the beginning, immediately after removal of the test chamber, and 15, 30, 60, 120, and 180 minutes later. Echographic recordings were performed by 20 MHz B-scanning and processed by a dedicated software (Dermavision 2D, Cortex Technology, Hadsund, Denmark) based on the selection of amplitudes of interest and segmentation procedures. Segmentation of the images was performed employing two amplitude intervals, respectively highlighting hyper-reflecting (epidermis, lower pare of dermis) and hypo-echogenic parts of the tissue. The evaluation of the dermis showed an attenuation of the hyper-reflecting areas of the deep dermis for all three substances and a significant decrease in echogenicity for petrolatum alone. Superficial hyper-reflecting areas assessing epidermis were significantly reduced in respect to baseline, at all assessment times for all three products. This echographic aspect corresponded to increased capacitance values, which were recorded for up to 180 minutes. In conclusion, 20 MHz B-scanning evaluation represents a valid support for the assessment of skin hydration
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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