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All Journal Pharmaceutical Sciences and Research (PSR) Journal of Technology Informatics and Engineering
Watanabe, Ken
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Computer Science & IT

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In vitro Antiviral Activity of Cat’s Claw (Uncaria tomentosa) bark Extract Against Human Influenza A Virus Makau, Juliann N; Talaam, Keith K; Odiwuor, Mike; Majanja, Janet M; Musenjeri, Sophia; Rahmasari, Ratika; Khamadi, Samoel A; Watanabe, Ken
Pharmaceutical Sciences and Research Vol. 12, No. 2
Publisher : UI Scholars Hub

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Abstract

Influenza A viruses mutate very fast and this leads to the development of resistance to antivirals, hence the need to find new therapeutics. Due to their extensive traditional use, natural products are crucial resources for the discovery of drugs. Cat’s claw (Uncaria tomentosa), is a tropical vine known for various health benefits and in this study we evaluated its anti-influenza activity. Pulverized material of the stem bark was extracted using 80% ethanol, hot water, and 1% sodium bicarbonate. The extracts were dried and dissolved in dimethylsulfoxide before testing for cytotoxicity and antiviral activity using crystal violet assay. The extracts exhibited antiviral activity with a 50% inhibitory concentration range of 2.3 - 6.2 µg/mL. The 1% sodium bicarbonate extract had the least 50% cytotoxic concentration of 125 µg/mL and was used for further analyses. It was effective against several human influenza A virus strains including an oseltamivir-resistant clinical isolate of the 2009 H1N1 pandemic influenza. Time-of-addition experiments showed significant suppression of virus replication when the virus was pretreated with the extract before infecting to cells and also when the virus and extract were co-administered to the cells; suggesting that the extract was inactivating the virus. Oseltamivir was used as a positive control and only suppressed late stages of virus replication. These results were consistent with the hemagglutination inhibition assay data which showed direct virucidal activity on influenza virus particles. Our data demonstrates possible future use of Cat’s claw in influenza management. However, more investigation is needed to identify the bioactive components.
User-Centered Mobile Navigation: Evaluating Local Usability for Improved UX Petrova, Sofia; Watanabe, Ken
Journal of Technology Informatics and Engineering Vol. 4 No. 3 (2025): DECEMBER | JTIE : Journal of Technology Informatics and Engineering
Publisher : University of Science and Computer Technology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51903/jtie.v4i3.457

Abstract

Mobile navigation interfaces continue to be plagued by the key usability problem, particularly where widely accepted design traditions fail to address the specific local user population requirements and mental models. This research addresses this significant limitation by using a thorough user-focused measurement framework to search for and investigate context-dependent navigation problems in mobile applications. The research employed a multi-method qualitative approach, using in-depth questionnaires, semi-structured interviews, and laboratory-based usability testing of 15 participants on an interactive Figma prototype that simulated real-world navigation tasks. Our analysis step by step revealed significant navigation issues within the local context, quantified using a 73% task completion rate and a 2.8 participant error average for the core navigation tasks. The most significant usability issues were ambiguous iconography, inconsistent application of platform design patterns, and insufficient system feedback mechanisms. The results conclusively demonstrate that localized usability testing is not merely beneficial but necessary while creating genuinely good and accessible mobile experiences. The study provides a replicable, practical context-aware evaluation approach and tangible, right-now applicable design recommendations, for example, the need to enhance icons with descriptive text labels and use instant visual feedback mechanisms. The study provides developers and designers tangible take-away recommendations for significantly enhancing navigation user experience without trading off methodological availability and implementation convenience in different development environments.
Co-Authors Khamadi, Samoel A Majanja, Janet M Makau, Juliann N Musenjeri, Sophia Odiwuor, Mike Petrova, Sofia Rahmasari, Ratika Talaam, Keith K