1,720,958 research outputs found
Synthesis of Zinc Oxide Nanoparticles via Biomass of Hypnea pannosa as a Green Mediator and their Biological Applications
No full textThe biological manufacturing of zinc oxide nanoparticles (ZnO-NPs) using renewable sources is safe, harmless, and compatible with the environment. The capacity of Hypnea pannosa to synthesize ZnO-NPs was investigated in this work. Ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential analysis were employed to characterize the ZnO-NPs. The created ZnO-NPs showed antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Acinetobacter baumannii, Candida albicans, and Candida auris. ZnO-NPs showed an MIC of 12.5 µg/mL against S. aureus, E. faecalis, K. pneumoniae, C. albicans, and C. auris, but it had a 25 µg/mL against Acinetobacter baumannii. ZnO-NPs' ability to scavenge free radicals was assessed using the 1,1-diphenyl-2-picryl hydrazyl (DPPH) technique with IC50 of 36.2 µg/mL. Anti-inflammatory activity of ZnO-NPs compared to indomethacin at 1000 µg/mL was investigated, where the membrane's maximum stabilizer was 93.3%. ZnO-NPs demonstrated anticancer activity against PC3 and Caco2 cell lines with IC50 of 174.3 μg/mL and 83.3 μg/mL, respectively. Furthermore, ZnO-NPs demonstrated a range of anti-biofilm activities against Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, ZnO-NPs showed encouraging antiviral effect versus COX B4 as well as HSV1 with antiviral activities of 54.8% and 61.1%, respectively
The Effect of Sewak on Oral Microbiota Composition
No full textConsiderable data by many experimental studies have provided that the S. persica plant and its chewing sticks (sewak) display beneficial effects for oral hygiene. To find out more about the shadowy benefits of sewak, we hypothesized that sewak can be a natural therapeutic approach that controls the microbiota composition. Surveys and mouthwash samples with and without the use of sewak were obtained from six healthy randomly selected volunteers. Samples were processed and DNA isolated using QlAamp kit. 16S metagenomics sequencing library approach (Illumina) for sequencing the variable V3 and V4 domains of the 16S rRNA gene was used since purposes such as genus and species were needed in this study. Each samples were sequenced to a depth of 380,000 reads in the paired-end 2x300 read format. Taxonomic identification and statistical analysis revealed that after using the sewak treatment, some species decreased and other increased (P \u3c 0.05). However, when the p-value was adjusted using FDR, results indicated that no one of the bacteria species can be considered as statistically significant (FDR\u3e0.05). The comprehensive examination of the relationship of sewak and the oral microbiota demonstrates that there is no difference in the entire number of bacteria before and after treatment, based on analysis. It is possible that sewak use may reduce oral bacteria in a global, proportional manner, such that the microbiome approach could not detect such changes, since the method is designed to measure composition changes, not absolute changes
Mechanisms of Resistance to the Novel Antibiotic Combination Ceftazidme/Avibactam and to Avibavtam Alone in Salmonella Enterica Serovar Senftenberg
No full textThe use of β-lactam/β-lactamase inhibitors combinations has been the most significant revolution to overcome β-lactamases resistance. In 2015, the Food and Drug Administration approved the use of ceftazidime/avibactam for infections caused by Enterobacteriaceae and Pseudomonas aeruginosa. Only limited data are currently available for resistance to this combination. The study, for the first time, aims to examine mechanisms of resistance to avibactam and to ceftazidime/avibactam in Salmonella senftenberg. Bacteria were challenged with gradually increasing concentrations of either avibactam or ceftazidime/avibactam, and developed resistance to the drugs at 10-fold of the initial MIC after 43 serial transfers. Whole genome and RNA sequencing was applied to determine whether new genetic variations are associated with the resistance. No mutations or hyperproduction of β-lactamases were found. Acquisition of ceftazidime/avibactam resistance was associated with mutations in PBP 2 and 3, porin, and major facilitator superfamily (MFS) transporter, whereas acquisition of avibactam resistance was associated with mutations in PBP2, S6 unit of 30S rRNA, MFS and ATP binding cassette (ABC) transporters. Altogether, this study raises the concern regarding the ability of ceftazidime-susceptible bacteria to develop resistance to this novel combination, a resistance that is also correlated with cross-resistance to other antibiotics
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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