Antimicrobial photodynamic therapy (aPDT) has been explored as an innovative therapeutic approach because it can be used to inactivate a variety of microbial forms (vegetative forms and spores) ...without causing significant damage to host tissues, and without the development of resistance to the photosensitization process. This study assesses the photodynamic antifungal/sporicidal activity of tetra- and octasubstituted phthalocyanine (Pc) dyes with ammonium groups. Tetra- and octasubstituted zinc(II) phthalocyanines (1 and 2) were prepared and tested as photosensitizers (PSs) on Fusarium oxysporum conidia. Photoinactivation (PDI) tests were conducted with photosensitizer (PS) concentrations of 20, 40, and 60 µM under white-light exposure at an irradiance of 135 mW·cmsup.-2, applied during 30 and 60 min (light doses of 243 and 486 J·cmsup.−2). High PDI efficiency corresponding to the inactivation process until the detection limit was observed for both PSs. The tetrasubstituted PS was the most effective, requiring the lowest concentration and the shortest irradiation time for the complete inactivation of conidia (40 µM, 30 min, 243 J·cmsup.−2). Complete inactivation was also achieved with PS 2, but a longer irradiation time and a higher concentration (60 µM, 60 min, 486 J·cmsup.−2) were necessary. Because of the low concentrations and moderate energy doses required to inactivate resistant biological forms such as fungal conidia, these phthalocyanines can be considered potent antifungal photodynamic drugs.
In this study, heterostructured g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to ...investigate the surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-Csub.3Nsub.4/Ag–TiOsub.2 heterostructured nanocomposite. The heterostructured g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiOsub.2, Ag–TiOsub.2, and g-Csub.3Nsub.4, respectively. The g-Csub.3Nsub.4/Ag–TiOsub.2 ternary composite demonstrated higher photocatalytic activity than pristine TiOsub.2 and binary Ag–TiOsub.2 photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposite can be attributed to the formation of an excellent heterostructure between TiOsub.2 and g-Csub.3Nsub.4 as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation.
Africa is a continent of opportunities that is likely to piay an increasingly important role in the future international division of labour. Yet, German companies' economic activity and investment in ...Africa is still limited. This article examines how the digital transformation is changing the investment and innovation conditions in Africa, how German companies can utilise new opportunities resulting from these changes and how politics can foster greater commitment by German and European companies in Africa. Afrika ist ein Kontinent der Chancen, der in der kunftigen weltwirtschaftlichen Arbeitsteilung eine deutlich grossere Rolle spielen durfte als bisher. Dennoch tut sich die deutsche Wirtschaft bislang schwer. Die digitale Transformation verandert die Investitions- und Innovationsbedingungen in Afrika. Daraus ergeben sich auch fur deutsche Unternehmen Chancen auf dem afrikanischen Kontinent. Die Politik sollte Rahmenbedingungen fur ein starkeres privatwirtschaftliches Engagement deutscher und europaischer Unternehmen in Afrika schaffen.
Combining intelligent and active packaging serves the dual purpose of detecting color changes in food that reflect changes in its quality and prolonging its shelf life. This study developed an ...intelligent and active packaging system made from the cellulose of Acetobacter xylinum and assessed its ability to detect changes in the quality and to increase shelf-life of packaged fresh beef. The properties of the intelligent packaging’s sensor and active packaging films were determined. The application of this system to fresh beef stored at room temperature (28 ± 2 °C) for 24 h was tested. The color of the bromothymol blue (BTB) solution (pH 2.75) in the indicator of the intelligent packaging system changed from orange to dark green to indicate that beef quality changed from fresh to rotten. The meat treated with the active packaging with 10% and 15% garlic extract decayed on the 16th h. In contrast, the meat treated with the active packaging without the garlic extracts rotted on the 12th h. The shift in the indicator’s color was linearly related to the total plate count (TPC), total volatile basic nitrogen (TVBN), and pH of the meat packaged using the active packaging system. Therefore, BTB solution (pH 2.75) can be used as an intelligent packaging indicator that will allow consumers to assess the quality of packaged meat easily. As an antimicrobial agent, the addition of 10–15% garlic extract to the active packaging films can help delay the spoilage of packaged beef.
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