The structural characteristics of photoageing in mice caused by the effects of ultraviolet A radiation

Background: Due to its deep penetration into the dermis, ultraviolet A (UVA) radiation is considered a primary factor in skin photoageing. The aim of this study is to use a qualitative and quantitative analysis to determine the structural parameters of skin photoageing in mice exposed to UVA radiation, with or without the application of a photoprotective cream. Materials and methods: The experiment consisted of the radiation of female BALBc mice in a solarium by UVA rays, up to total dosages of 7800 J/cm2 and 12500 J/cm2. A total of 78 animals were divided into four experimental and two control groups. All animals were shaved and the animals in two experimental groups were treated with a photoprotective cream half an hour before exposure. The samples of the treated skin were stained with haematoxylin eosin and Van-Gieson staining methods. All measurements, except for the presence of dyskeratosis, were taken using ImageJ 150i software. Results: In the study, the signs of skin photoageing were more evident in untreated groups of animals. Dyskeratosis was more frequent in both of the untreated groups of animals (p = 0.004 and p = 0.003). The lowest values of epidermal thickness (13.8 ± 2.6 μm and 12.7 ± 2.3 μm) were present in both of the untreated groups of animals (p < 0.001 and p < 0.001). The highest values of stratum corneum thickness (34.3 ± 8.5 μm) were observed in the untreated, shorter radiated group of animals (p < 0.001) which was irradiated for the shortest period of time. Beside the control groups, the highest length of dermo-epidermal junction was recorded in the group of treated, longer radiated animals (1467.6 ± 94.6 μm; p = 0.373). The lowest values of dermal thickness (115.9 ± 10.5 μm and 134.8 ± 21.8 μm) and volumetric density of the collagen fibres (31.92 ± 3.19% and 29.40 ± 4.54%) were present in both untreated groups of animals (p < 0.001, p < 0.001, p = 0.035). Conclusions: Skin photoageing was most pronounced in the groups of animals irradiated without the application of photoprotective cream

Agricultural Cooperatives in Serbia

Agricultural cooperative has a long tradition in the Republic of Serbia. In the past period, agricultural cooperative passed through various stages of development and operation, with ups and downs, both in its organization, and in material development. The goal of this study is to determine the state of cooperatives in Serbia. In this regard, following indicators and parameters were analyzed: the number, structure and main activity of agricultural cooperatives, types of services that cooperatives provide to their members, participation of agricultural cooperatives in the purchase of products, cooperative property, financial results, cooperative audits, and cooperative staff training. The sources of data were obtained using the methods of interviewing some 30 % of active cooperatives in RS, through interviews and participatory methods of participation through workshops and groups of practicing students

Can UVA radiation have a germicidal effect?

This study examines the efficiency of UVA radiation in the eradication of murine mites. The experiment consisted of the radiation of female BALBc mice in a solarium by UVA rays, up to total dosages of 7800 J/cm2 and 12 500 J/cm2. A total of 88 animals were divided into four experimental and three control groups. Animals from the experimental and two control groups were shaved, and animals in two experimental groups were treated by a photoprotective cream half an hour before exposure. The animals in the third control group were not shaven. The presence of mites was detected in histological preparations of most of the animals in the control groups. When compared to the experimental groups of animals exposed to radiation up to 7800 J/cm2, the presence of mites was significantly more frequent in the control group of shaven animals (p = 0.013) and unshaven animals (p < 0.001). When compared to the experimental groups exposed to radiation up to 12 500 J/cm2, the presence of mites was significantly more frequent in the control group of shaven animals (p < 0.001) and unshaven animals (p < 0.001). Median value of mites was statistically much higher in the control, unshaven group of animals in comparison to the untreated group of animals exposed to radiation up to 7800 J/cm2 (p = 0.006). Median value of mites between untreated group of animals exposed to radiation up to 7800 J/cm2 and their shaven control group was near a statistically significant difference (p = 0.056). By comparing the number of mites between the control groups of animals, no presence of statistically significant difference (p = 0.901) was confirmed. UVA radiation led to the effective eradication of murine mites