Difficulties in obtaining human nails that are large enough for examining the penetration of drug formulations led us to produce keratin films regenerated from human hair. We assume that these films ...can simulate human nail plates in drug penetration and permeation tests and can serve as a biological model for studying onychomycosis. The films were formed from keratin extracted from human hair using dithiothreitol, urea and thiourea. The obtained keratin extract was dispensed into Teflon rings and dried at 40 °C and then cured at 110 °C. The structure, surface morphology, chemical characterization and thermal stability of the films were characterized and were compared to those of human nail, hair and bovine hoof samples using SDS-electrophoresis, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The structure of the obtained films was found to be closer to human nails than to hair or bovine hooves. The keratin films were infected with
and were proven to be appropriate for serving as a model for studying onychomycosis.
The photosensitizers Rose Bengal (RB) and methylene blue (MB), when immobilized in polystyrene, were found to exhibit high antibacterial activity in a continuous regime. The photosensitizers were ...immobilized by dissolution in chloroform, together with polystyrene, with further evaporation of the solvent, yielding thin polymeric films. Shallow reservoirs, bottom-covered with these films, were used for constructing continuous-flow photoreactors for the eradication of Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli and wastewater bacteria under illumination with visible white light using a luminescent lamp at a 1.8 mW·cm⁻² fluence rate. The bacterial concentration decreased by two to five orders of magnitude in separate reactors with either immobilized RB or MB, as well as in three reactors connected in series, which contained one of the photosensitizers. Bacterial eradication reached more than five orders of magnitude in two reactors connected in series, where the first reactor contained immobilized RB and the second contained immobilized MB.
Conventional methods of onychomycosis treatment are ineffective in some cases because the cure of onychomycosis very often depends on the patient's individual response to the treatment; therefore, ...there is a crucial need to research and develop new methods of onychomycosis therapy. One of the most innovative treatments is photodynamic therapy (PDT) using photosensitizers (PSs). However, effective treatment depends on the correct choice of photosensitizer and substances that improve the characteristics of the final formulation. The aim of our work was to find an effective formulation for the treatment of onychomycosis. To achieve this goal, we tested the effect of three types of PSs, rose Bengal (RB), malachite green oxalate (MGO), and methylene blue (MB), on
. The most effective PS was RB, and so the study was continued with
. Additional comparative studies were carried out on substances included in the formulation (urea and thiourea), focusing on their antifungal activity, which can improve penetration through the nail plate. The composition of the formulation that achieved 100% eradication of
under our conditions consisted of 150 μM RB, 5% urea, and 0.5% thiourea in glycerol/water (70/30%,
/
) solution. A white luminescent lamp was used as a light source (1.9 ± 0.1 mW cm
). Stability of the formulation was checked. The selected formulation shows potential for future simplification and acceleration of PDT treatment of onychomycosis.
Fresh water shortage has become a global problem. A partial solution for this problem is the use of treated and disinfected wastewater for irrigation. However, most existing wastewater disinfection ...methods are based on the use of aggressive chemicals or power-consuming physical processes. Photodynamic eradication of waterborne bacteria by immobilized photosensitizers may be a good alternative to conventional methods. In the present work, the photosensitizers Rose Bengal sodium salt, Rose Bengal lactone, methylene blue, and hematoporphyrin were immobilized in polyethylene or polypropylene using a “green” method of co-extrusion, without addition of any chemicals, yielding polymeric strips and beads containing the photosensitizers. The antibacterial efficiency of these immobilized photosensitizers was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli in batch and continuous regimes upon illumination with a white luminescent lamp. All examined photosensitizers demonstrated a good ability to decrease the bacterial concentration, up to their total eradication. Immobilized photosensitizers are proposed for batch or continuous disinfection of wastewater after secondary treatment.
Titanium alloys have advanced mechanical properties jointly with high biocompatibility that make them eminently suitable for biomedical applications such as dental and orthopedic implants. ...Improvement in their osseointegration with human bone can be achieved by the development of hydroxyapatite (HAp) on a Ti alloy surface using different methods of deposition. However, plasma electrolytic oxidation (PEO) treatment has been found to be one of the most promising techniques, due to the formation of high bonding between the bone and the Ti surface. Along with this high bonding, an antibacterial ability of the surface to prevent bacterial infection is also essential. Silver, which is a widely applicable antibacterial agent, was used in this work. First, a titanium oxide coating containing calcium and phosphorus and Ag nanoparticles was formed by PEO treatment. Then, Ti alloy was subjected to hydrothermal treatment to ensure a crystalline formation of HAp. Morphology and phase composition investigations detected the presence of HAp crystals in the coating along with antibacterial agents of silver nanoparticles. The biocompatibility and bioactivity of the created coating were examined by contact angle (CS) measurement and electrochemical impedance spectroscopy (EIS). It was shown that the coating was extensively grown after exposure of the alloy to simulated body fluid (SBF) solution for 7 days with no effect on the Ag nanoparticles. An antibacterial test using Staphylococcus aureus and Escherichia coli revealed that the coating containing Ag nanoparticles has more significant antibacterial effectiveness compared to a coating that does not contain silver.
Photosensitizers immobilized in polymers can serve as antibacterial surfaces or coatings and can be applied for disinfection of water or medical instruments. The antibacterial activity of the ...immobilized photosensitizers is based on their excitation by visible light followed by energy transfer from the photosensitizers to oxygen dissolved in an aqueous phase which produces reactive oxygen species that cause irreversible damage to bacterial cells. The photosensitizer Rose Bengal immobilized in polystyrene, polycarbonate and poly (methyl methacrylate) was shown to eradicate Gram-positive Staphylococcus aureus bacteria under moderate illumination.
The Templates for Sustainable Product Development (TSPD) is a tool for sustainability practitioners to assist product development teams with bringing sustainability considerations to the early phases ...of product development in a strategic, quick and resource-efficient way. This thesis project builds on the earlier TSPD work by investigating the ways in which sustainability practitioners could apply the TSPD in order to improve the outcomes. The factors influencing the quality of the outcomes of a TSPD application were investigated. Then, support was developed for use by sustainability practitioners to address these factors. This support was field tested and refined in four iterations. It was discovered that achieving high quality outcomes from a TSPD application is dependent on having both high quality strategic sustainable product development content and high quality facilitation of the people considering this content. The quality of both content and facilitation influences the participants’ level of engagement, which influences the quality of the outcomes of the TSPD application. The support was developed such that it assists sustainability practitioners in addressing both content and facilitation through a participatory approach. There is some evidence that use of the developed support contributed to both high level of participants’ engagement and high quality outcomes of the TSPD applications.
Blog at http://sustainableproductdevelopment.blogspot.se/
Eastern Europe and Central Asia (EECA) countries have higher cervical and breast cancer mortality rates and later stage at diagnosis compared with the rest of WHO European Region. The aim was to ...explore current early detection practices including "dispensarization" for breast and cervix cancer in the region.
A questionnaire survey on early detection practices for breast and cervix cancer was sent to collaborators in 11 countries, differentiating services in the primary health setting, and population-based programs. Responses were received from Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, the Russian Federation (Arkhangelsk, Samara and Tomsk regions), Tajikistan, Ukraine, and Uzbekistan.
All countries but Georgia, Kyrgyzstan, and the Russian Federation had opportunistic screening by clinical breast exam within "dispensarization" program. Mammography screening programs, commonly starting from age 40, were introduced or piloted in eight of nine countries, organized at national oncology or screening centres in Armenia, Belarus and Georgia, and within primary care in others. Six countries had "dispensarization" program for cervix cancer, mostly starting from the age 18, with smears stained either by Romanowsky-Giemsa alone (Belarus, Tajikistan and Ukraine), or alternating with Papanicolaou (Kazakhstan and the Russian Federation). In parallel, screening programs using Papanicolaou or HPV test were introduced in seven countries and organized within primary care.
Our study documents that parallel screening systems for both breast and cervix cancers, as well as departures from evidence-based practices are widespread across the EECA. Within the framework of the WHO Initiatives, existing opportunistic screening should be replaced by population-based programs that include quality assurance and control.
An interference of heavy-fermion superconductivity (SC) and antiferromagnetism (AFM) has been studied in the framework of the periodic Anderson model with the superexchange interaction between ...localized electrons. It has been shown that pressure-induced energy change of the localized states leads to modifying antiferromagnetic and superconducting order parameters. Conditions have been found for the coexistence of SC and AFM in the model. Theoretical results of the pressure effects on the ground state character of the heavy-fermion systems are in good agreement with experimental data for a rare-earth intermetallic compound CeRhIn
5
. The divergence of the effective electron mass produced by suppressing the long-range antiferromagnetic order has also been analyzed in the same framework.
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