1,720,981 research outputs found
Performance Evaluation of a Computational Design Tool for Three-point Hitch Geometry Optimization
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Encapsulation of octenidine hydrochloride into bioresorbable polyesters for extended antimicrobial activity
Full text linkNosocomial infections remain a serious threat even for patients of highly industrialized countries. These infections occur on surgical sites and wounds, on catheter entry sites, tubes and other indwelling devices. Medical devices providing local antiseptic action over an extended time period represent an opportunity to prevent such infections. One way to achieve this goal is the encapsulation of active molecules into bioresorbable polymer microparticles, which can locally release the compound of interest along a tunable time span depending on the polymer characteristic. In this work, spray drying is used to encapsulate the broad band antiseptic octenidine hydrochloride into a set of poly(D,L-lactide) (PDLLA) and poly(D,L-lactide-co-glycolide) (PLGA) carrier materials with different molecular weights and chain end-groups, forming redispersable powders. It is demonstrated that the carrier materials bearing acid end-groups provide a significantly larger entrapment efficacy comparing with their ester counterparts independently of carrier composition and molecular weight. The quantitative understanding of the release mechanism allows guiding the selection of suitable encapsulating polyesters to tune initial burst and long time release of a given drug. Finally, it is demonstrated on cultures of Staphylococcus epidermidis that the encapsulated and subsequently released OHC has conserved its antiseptic activity, which supports the potential applicability of the approach
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
Health care-associated infections: Controlled delivery of cationic antiseptics from polymeric excipients
Full text linkNowadays, the treatment of health care-associated infections represents a serious issue, due to the increasing number of bacterial strains resistant to traditional antibiotics. The use of antiseptics like quaternary ammonium salts and biguanides is a viable alternative to face these life-threatening infections. However, their inherent toxicity as well as the necessity of providing a sustained release to avoid the formation of pathogen biofilms are compelling obstacles towards their assessment in the hospitals. Within this framework, the role of polymeric drug delivery systems is fundamental to overcome the aforementioned problems. Biocompatibility, biodegradability and excipient-drug interactions are crucial properties determining the efficacy of the formulation. In this work, we provide an in-depth analysis of the polymer drug delivery systems that have been developed or are under development for the sustained release of positively charged antiseptics, highlighting the crucial characteristics that allowed to achieve the most relevant therapeutic effects. We reported and compared natural occurring polymers and synthetic carriers to show their pros and cons and applicability in the treatment of health care-associated infections. Then, the discussion is focused on a particularly relevant class of materials adopted for the scope, represented by polyesters, which gave rise, due to their biodegradability, to the field of resorbable drug delivery devices. Finally, a specific analysis on the effect of the polymer functionalization over the formulation performances for the different types of polymeric carriers is presented
Review of foot tumors seen in a university tumor institute.
No full textMost tumors of the foot and ankle will be benign, and it has been easy for clinicians to underestimate the malignant potential of a given tumor. The purpose of our study was to gain insight into the incidence of different tumor types diagnosed in patients with tumors of the foot and/or ankle treated at the Rizzoli Institute from September 1990 to December 2007. Our series included 1170 patients and 1170 lesions, with an overall mean age at diagnosis of 43 (range 5 to 81) years. Overall, 870 lesions (74.36%) were nonmalignant and 300 (25.65%) were malignant. Soft tissue lesions were diagnosed in 189 patients (16.15%), of which 91 (48.15%) were nonmalignant (pseudotumors or benign). Bone lesions were diagnosed in 981 patients (83.85%), of which 779 (79.41%) were nonmalignant. Epidemiologic knowledge of foot abnormalities and clinical suspicion, an organized diagnostic method, and evidence-based treatment of musculoskeletal tumors are essential elements to obtaining optimal results in the treatment of malignant foot tumors.
Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved
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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