1,720,981 research outputs found
A novel technology for disinfecting surfaces infested with Candida auris: the UVC chip: Elena Frongillo
Full text linkBACKGROUND: The fungal pathogen Candida Auris is increasingly associated with multidrug-resistant infections that are highly expensive for the Health Care System. The spreading of this pathogen can occur, among others, through contact with infected surfaces or medical instruments. This study evaluated the efficacy of a novel UVC chip, novel alternative to UVC LEDs and lamps, in inactivating Candida auris strain. METHODS: This experimental study was carried out between July and September 2020 at the University of Siena. Candida auris (ATCC 12372) at two known concentrations (1.5X107 and 1.5x106 CFU/ml) at a fixed distance (7,5 cm) from the chip (5.1mW radiant power) was tested, in triplicates, with three exposure times (5, 10 and 15 minutes). Potato Dextrose Agar (PDA) plates without the plate lid and containing Candida auris were exposed to UVC light. Subsequently, the plates were incubated at 36 °C for 48 h. Log reduction between treated and positive control (not exposed to UVC light) samples was calculated. RESULTS: At 15 minutes, we had the highest inactivation result, mean 4.43 log10, starting from a 1.5x106 CFU/mL concentration. At a higher concentration, 1.5X107 CFU/mL, the reduction had a mean of 3.51 log10. CONCLUSIONS: The results of the experiments showed a significant microbial reduction in relation to the exposure time. The highest level of reduction was reached after 15 minutes of exposure. UVC chip had a relevant biocidal effect on Candida auris and may represent a valuable tool in the prevention of infections caused by this pathogen, which is becoming increasingly prevalent and persistent globally. KEY MESSAGES: • The use of UVC Chip decreases surface contamination. • New technology against healthcare-associated infections
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
Analysis of the physical and microbiocidal characteristics of an emerging and innovative UV disinfection technology
No full textIntroduction Surface disinfection is one of the key points to reduce the risk of transmission both in healthcare and other public spaces. A novel UV-chip disinfection technology is presented. Technological, photonic and microbiocidal characteristics are evaluated taking as reference an ultraviolet-C (UV-C) LED source of equivalent radiant power.
Methods The UV chip has a circular radiating surface with a diameter of 1.3 cm, emitting UV cold light at about 5 mW and driven current of about 80 μA. Four bacterial strains were used to conduct the microbiological tests at 4°C and 60°C to evaluate the bactericidal performance of the two technologies under the same operating conditions.
Results Spectral differences were found between the UV-C LED and the chip, with an emission curve strictly around 280 nm and a broader band centred around 264 nm, respectively. Between-technology microbiological inactivation levels were comparable, achieving total abatement (99.999%) in 8 min at 7.5 cm.
Discussion The UV chip exhibits unique properties that make it applicable in some specific contexts, where UV-C LEDs present the most critical issues. Besides, it is portable and exhibits a broad spectrum of UV wavelengths with a peak where the maximum microbiocidal efficacy occurs. Important issues to be addressed to improve this technology are the high voltage management and the too low energy efficiency.
Conclusion This cold emission technology is virtually unaffected by changes in ambient temperature and is particularly useful in short-distance applications. Recent developments in technology are moving towards a progressive increase in the chip’s radiant power
A simulation model of microbe overlapping for the correct estimation of UV-C device log-reduction
No full textVariations 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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