Open University of Sri Lanka

Fungal nail infections (onychomycosis) remain challenging to treat due to prolonged therapy, poor cure rates, and safety concerns associated with oral antifungal agents. Although topical formulations are the preferred treatment option, their clinical effectiveness is constrained by the dense keratinized nail barrier. While formulation-driven strategies and device-based therapies have expanded the therapeutic approaches for onychomycosis, their clinical efficacy remains suboptimal, pointing towards the need for pre-clinical evaluation of their performance using more clinically relevant models during the development stage. Nail-integrated model systems provide a platform for evaluating the efficacy of novel antifungal topical treatments in a controlled disease-mimicking environment, thereby enhancing the likelihood of clinical success. This review critically evaluates in vitro and ex vivo models, including keratin-supplemented media, keratin biomembranes, animal hooves, and human nails, focusing on their physiological relevance, advantages and inherent limitations. Ex vivo experimental model designs reported in recent studies are discussed to spotlight their application in evaluating topical formulations and device-based interventions. Ex vivo human nail models, when rationally designed to reflect the structural and pathological architecture of onychomycosis, offer robust, clinically predictive platforms for formulation and device optimization, dose and treatment frequency and comparative efficacy assessment. Infected animal hooves serve as a surrogate for human nails and provide reproducible experimental models for screening the antifungal efficacy under standardized conditions. The available ex vivo data support the utility of these models in predicting clinical performance of antifungal formulations and devices during pre-clinical development; however, broader industrial adoption will require standardized and harmonized protocols, as well as further clinical validation.

Purpose This study aims to examine how travel influencers’ congruence with endorsed travel brands and alignment with their followers affect travel purchase behavior, addressing a critical gap in tourism marketing literature. Design/methodology/approach A novel conceptual framework grounded in the source credibility model and the persuasion knowledge model is proposed. A quantitative cross-sectional survey was conducted among 374 Sri Lankan travelers who actively engage with travel-related content on Instagram. The hypotheses were tested using partial least squares structural equation modeling. Findings Travel influencers who are perceived as trustworthy, attractive and congruent with both the endorsed travel brand and their audience enhance perceived authenticity. This perceived authenticity positively influences attitudes toward the travel brand, which in turn drives travel purchase behavior. Originality/value This study frames perceived influencer authenticity as a process-based mediator critical to the recognition of native advertising. Leveraging Sri Lanka’s emerging tourism context as a boundary condition, it demonstrates how authenticity mediates influencer–brand and influencer–follower congruence and provides actionable insights for designing credible, trust-enhancing and effective tourism promotion strategies.

Sustainable river management depends on indices that balance human water demands with ecological flow requirements while accounting for hydrological variability. Existing water scarcity and withdrawal indices are largely based on monthly or annual aggregates, often neglecting daily variability and the effects of drought buffering. This study introduces the Extractable Water Index (EWI), a novel, dimensionless metric that quantifies the sustainable potential for water extraction using daily flow records. The EWI integrates mean available flow, flow variability, low-flow thresholds, and storage contributions into a single expression, thereby capturing both hydrological dynamics and ecological protections. Two scenarios were evaluated, (i) no-storage and (ii) with-storage, with the latter employing a semi-analytical approximation to represent a reservoir or pond. The EWI was applied to 20 daily river flow series for 16 river basins in Sri Lanka. Under no-storage conditions, thresholds were defined as follows: EWI < 0.45 indicates low extraction potential; 0.45 < EWI < 0.60 indicates moderate extraction potential; and EWI > 0.75 indicates high extraction potential. The results demonstrate that even modest storage can substantially enhance sustainable withdrawals. The EWI provides a transparent, reproducible decision-support tool that complements environmental flow standards and prioritizes rivers based on extractability. The EWI provides a valuable tool for estimating water extraction potential within the Sri Lankan context. This index can be applied across diverse hydroclimatic regimes and, when combined with threshold validation, can predict extraction requirements under varying seasonal flow conditions.

This study describes two collections of saprobic gilled mushrooms morphologically identified as Psathyrella and collected in Qujing, Yunnan Province, China. Based on multi-gene phylogenetic analyses of nrITS, nrLSU, and tef-1α sequences, two collections were confirmed to belong to the Psathyrella sections Atomatae and Hydrophilae. Morphologically, Psathyrella qujinguniversitatica (Psathyrella sect. Atomatae) is characterized by small basidiomata, a beige to light brown pileus, large basidiospores, and partially thick-walled cheilocystidia, while P. yunnanensis (Psathyrella sect. Hydrophilae) is characterized by a pileus that gradually changes from orange-brown to lighter towards the margin, with the edge light brown to brown, distinct striations, a fibrillose veil, larger basidia, and partially thick-walled cheilocystidia. Descriptions, illustrations, and phylogenetic analyses of the two new species are provided. In addition, the present study updates the number of Psathyrella species reported from China to 55, along with their known distribution.

The effect on the photovoltaic properties of the TiO2-based cadmium sulfide (CdS) quantum dot sensitized solar cells (QDSSCs) was investigated by incorporating carbon quantum dots (CQDs) synthesized via a cold atmospheric plasma method. CQD incorporated photoanodes were characterized by SEM, TEM, XRD, Raman spectroscopy, FTIR spectroscopy, PL spectroscopy, UV-visible spectroscopy, and Mott-Schottky techniques. TEM measurements revealed that the CQDs were mostly spherical with an average diameter of similar to 3 nm. The presence of CQDs in the TiO2 photoanode was confirmed by both Raman spectroscopy and FTIR measurements. The findings from the PL and IPCE analyses showed that CQDs functioned as an energy down-converting material, broadening the responsive range of the CdS QDSSC to encompass higher energy photons. QDSSCs fabricated with CQDs-incorporated photoanode, a sulfide redox couple, and a Pt counter electrode exhibited a 31.3 % enhancement in power conversion efficiency, leading to a 1.68 % efficiency compared to the 1.28 % efficiency of the pristine TiO2 photoanode.