1,720,960 research outputs found
Phytochemical, Antioxidant, and Antibacterial Activities of Stem Bark Fractions of Eucalyptus globulus Against Multidrug-Resistant Bacterial Isolates
Full text linkThe growing challenge of antimicrobial resistance (AMR) has intensified the need for alternative therapeutic agents, with medicinal plants offering promising solutions due to their bioactive compounds. This study investigated the antimicrobial and antioxidant properties of Eucalyptus globulus bark extracts against multidrug-resistant bacteria (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus). Plant samples were collected from Adamawa State Polytechnic, Nigeria, authenticated (voucher ASP-765), and subjected to reflux extraction using hexane and water. Phytochemical analysis revealed alkaloids, phenols, tannins, glycosides, and terpenoids in both methanol and aqueous extracts, while flavonoids and steroids were absent in aqueous extracts, and methanol extracts lacked saponins. Antibacterial activity was assessed through agar well diffusion and broth dilution assays, demonstrating a concentration-dependent effect. Methanol extracts showed greater efficacy against E. coli and P. aeruginosa (12.8–13.8 mm inhibition zones), while aqueous extracts were most effective against S. aureus (19.3 mm at 100 mg/mL). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 25 to 50 mg/mL, with E. coli exhibiting the lowest MIC (25 mg/mL), highlighting the extract’s antimicrobial potential. The antioxidant activity was evaluated using phosphomolybdate and ferricyanide assays. The methanol extract exhibited strong free radical scavenging activity, with a total antioxidant capacity (TAC) expressed in ascorbic acid equivalents (AAE), although lower than pure ascorbic acid. Statistical validation (one-way ANOVA, p < 0.05) confirmed the significance of the results. These findings support the traditional medicinal use of E. globulus and its potential for combating antibiotic-resistant infections and oxidative stress-related conditions. Further studies are recommended to isolate bioactive compounds, determine mechanisms of action, and develop optimized therapeutic formulations for AMR management
Phytochemical Profile and Antibacterial Activity of Nigella Sativa against Biofilm-producing Bacteria Uropathogens
Full text linkThis study explores the antibacterial effects of Nigella sativa seeds on bacteria obtained from clinical samples. The aim was to assess the antibacterial properties of both aqueous and methanolic extracts of Nigella sativa seeds against E. coli, S. aureus, and P. aeruginosa. The three samples were collected from the Microbiology Laboratory of Modibbo Adamawa Medical Centre and were reconfirmed using culture, microscopy, and some biochemical tests. The seed samples of N. sativa were procured from herbal point Yola, Adamawa State, Nigeria. The phytochemical assay of the extracts revealed the presence of flavonoids, alkaloids, tannins, phenols, cardiac glycosides, steroids, saponins, and terpenoids in both extracts. The highest antibacterial activity against S. aureus, E. coli, and P. aeruginosa was demonstrated by the aqueous extract of N. sativa seeds, with inhibition zone diameters of 19.30 ±0.61 mm, 8.10 ±2.17 mm, and 12.00 ±0.29 mm, respectively. However, the methanol extract exhibited slightly greater activity against E. coli and P. aeruginosa, with inhibition zone diameters of 12.10 ±0.38 mm and 13.80 ±0.40 mm, respectively. Both methanol and aqueous extracts showed minimum inhibitory concentrations (MICs) of 25 mg/mL against S. aureus and E. coli. Similarly, for P. aeruginosa, the MIC was 25 mg/mL for methanol extract and 50 mg/mL for aqueous extract. The minimum bactericidal concentration (MBC) for both extracts against S. aureus and E. coli was determined to be 25 mg/mL. However, for P. aeruginosa, the MBC was 25 mg/mL for the aqueous extract and 50 mg/mL for the methanol extract. The study indicates that N. sativa seed extract possesses antibacterial properties against S. aureus and P. aeruginosa, underscoring its potential as an effective medicinal antibacterial agent
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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