Tomas Bata University in Zlín

Tracer diffusion coefficients of sodium hyaluronate in 0.005 mol dm −3 aqueous drug solutions were investigated by using Taylor dispersion technique at 298.15 K. The drugs studied were caffeine, isoniazid, sodium sulfamerazine, sodium salicylate, and paracetamol. The positive cross-diffusion coefficient between the supporting drug and tracer polyelectrolyte obtained for all systems, particularly for isoniazid, sodium sulfamerazine, and sodium salicylate, indicate the existence of NaHy–drugs interactions and significant coupled diffusion. These findings suggest that sodium hyaluronate may facilitate drug transport, acting as a carrier in aqueous media.

Functional polymer surfaces that combine antimicrobial activity with retained processability and physicochemical stability are of growing interest for healthcare and high-contact applications. This study reports a photodynamically active poly(vinyl chloride) (PVC) material functionalized with a methacrylate-modified zinc phthalocyanine photosensitizer (ZnPTC-HEMA) and zinc pyrithione (ZPT), fabricated using industrially relevant melt processing and compression molding methods. The resulting material exhibited efficient singlet oxygen generation even at low ZnPTC-HEMA loadings, with activity approaching saturation at higher concentrations. Under visible light irradiation, the modified PVC surfaces exhibited pronounced antibacterial activity against Staphylococcus aureus and achieved more than a 5-log reduction of the enveloped bacteriophage Φ6, whereas the non-enveloped phage ΦX174 remained unaffected. The addition of ZPT further broadened antibacterial efficacy, including under dark conditions. Morphological, spectroscopic, thermal, and mechanical analyses confirmed homogeneous additive incorporation, preservation of the PVC chemical structure, and retention of material integrity at low to moderate additive loadings. Migration studies further demonstrated no detectable release of ZnPTC-HEMA after prolonged aqueous exposure. These results establish phthalocyanine functionalized PVC as a scalable light responsive antimicrobial material in which photoactive functionality can be introduced without compromising key processing and performance characteristics.

SummaryPolyvinyl acetate (PVAc) is a highly polar, fluorine-free polymeric adhesive that combines strong interfacial adhesion with good processability. Despite this, PVAc has rarely been investigated as an active layer in mechano-electric nanogenerators, even though its strong adhesion facilitates effective interfacial contact, thereby eliminating the need for auxiliary conductive layers. Electrical measurements revealed that the electrical output of PVAc arises from the interplay of triboelectric charge transfer, electrostatic induction driven by residual polarization, and deformation-induced interfacial polarization. The nanogenerators achieved an open-circuit voltage up to 350 V, a short-circuit current density of 1.8 μAcm−2, and power density of 0.07 mWcm−2 at a maximum power point of 4.4 MΩ. Stable output over 104 cycles demonstrated that PVAc is a suitable polymer for a new generation of fluoropolymer-free nanogenerators and flexible pressure sensors.

Abstract Adolescent girls living in internally displaced persons (IDP) camps manage menstruation amid food insecurity, inadequate water, sanitation and hygiene (WASH), disrupted education, gendered social norms and protection systems. These challenges are often addressed through separate humanitarian programmes, obscuring how they interact in girls’ everyday lives. This study explored menstrual-health experiences and perceived nutritional deprivation among adolescent girls in five IDP camps in Benue State, Nigeria. We conducted a focused ethnographic qualitative study in the International Market, Mega, Ortese, Uikpam, and Abagana camps. Twenty-five in-depth interviews with menstruating adolescent girls aged 13–19 years were complemented by focus group discussions with adolescent girls, adult women, adult men, and camp leaders, and structured WASH and food observations. Interviews and discussions were conducted in English, Tiv or both, transcribed verbatim and translated where necessary. Data were managed in MAXQDA and analysed using reflexive thematic analysis. Frequencies describe the distribution of 435 coded excerpts and are not participant prevalence estimates. Six themes and 20 subthemes were generated. Menstrual-health management and material constraints accounted for 95 coded excerpts (21.8%), followed by knowledge and lived experience (80; 18.4%), food insecurity and perceived nutritional deprivation (70; 16.1%), coping and adaptive agency (70; 16.1%), sociocultural beliefs and taboos (65; 14.9%), and self-reported symptoms and participation restrictions (55; 12.6%). Girls described irregular access to commercial pads, reliance on improvised materials, limited water and soap, and toilets that were unsafe or inaccessible at night. Dietary monotony, meal skipping, and hunger were perceived to intensify pain, weakness, and fatigue. Fear of staining, menstrual silence, and household restrictions contributed to withdrawal from school, livelihood, and domestic activities. Peer support was protective, but some girls undertook informal work to obtain menstrual materials, raising safeguarding concerns. Menstrual health in prolonged displacement is not an isolated hygiene issue but an outcome of interacting material, nutritional, sociocultural, educational, and protection constraints. Humanitarian responses should combine predictable access to acceptable menstrual materials with safe WASH facilities, adolescent-responsive food and nutrition support, confidential health services, community education and safeguarding mechanisms. Reported symptoms and nutritional experiences were not clinically measured.