Long-term Exposure of High Concentration Silver Nanoparticles Induced Toxicity, Fatality, Bioaccumulation, and Histological Alteration in Common Carp Fish (Cyprinus carpio)

BackgroundCurrently, nanotechnology and nanoparticles have been quickly emerged and have gained the attention of scientists due to its massive applications in environmental sectors. However, these environmental applications of silver nanoparticles potentially cause serious effects on terrestrial and aquatic organisms. In the current study, freshwater fish C. carpio were exposed to blood mediated AgNPs for toxicity, mortality, bioaccumulation, and histological alterations. Silver nanoparticles were fabricated using animal blood serum and their toxic effect was studied against common carp fish at different concentrations level (0.03, 0.06, and 0.09 mg/L).ResultsThe findings have revealed a little effect of blood induced silver nanoparticles (B-AgNPs) on fish behavior at the highest concentration (0.09 mg/L). However, bioaccumulation of B-AgNPs was reported in different organs of fish. Maximum bioaccumulation of B-AgNPs was reported in the liver, followed by intestine, gills, and muscles. Furthermore, the findings have showed that the B-AgNPs bioaccumulation led to histopathological alterations including damage structure of gills tissue and caused necrosis. It is summarized that histopathological alteration in gills and intestine mostly occurred at the highest concentration of B-AgNPs (0.09 mg/L). ConclusionThis study provides evidence of the AgNPs influence on aquatic life; however, further systematic studies are crucial to access the effects of AgNPs on aquatic life.

INFORMATION ABOUT SCIENTIFIC STUDDING LEVEL ON PROBLEM OF HYPERTENSION-MEDIATED ORGAN DAMAGE IN MONGOLIA

Despite of arterial hypertension high prevalence and its complications in Mongolia, the epidemiology and structure of hypertension-mediated organ damage remains insufficiently studied. Aim. To assess elaboration level of the problem of AH-associated hypertension-mediated organ damage in Mongolia. Materials and methods. Leading international guidelines and recommendations, reviews, meta-analyzes, randomized controlled, population-based research and Mongolian scientific papers with different evidential value, related to hypertension-mediated organ damage were analyzed. Results and discussion. In developed countries, hypertension-mediated organ damage structure and their contribution to total cardiovascular risk stratification in patients with hypertension is well studied. In 2018 ESC/ESH Guidelines for the management of arterial hypertension hypertension-mediated organ damage criteria were only slightly extended. Data on arterial hypertension epidemiology, including hypertension-mediated organ damage structure, in Mongolian population, mainly obtained from ethnic Mongols living in the territory of Inner Mongolia and other provinces of China, or in international studies with Mongolia participation. Directly in Mongolia, hypertension-mediated organ damage were studied in small samples; a systemic epidemiological analysis of hypertension-mediated organ damage was not carried out. Conclusions. Given arterial hypertension significance in Mongolia and insufficient scientific elaboration of problem, population studies are needed to clarify hypertension-mediated organ damage prevalence and structure in order for improving arterial hypertension management.

Melanism protects alpine zooplankton from DNA damage caused by ultraviolet radiation

Melanism is widely observed among animals, and is adaptive in various contexts for its thermoregulatory, camouflaging, mate-attraction or photoprotective properties. Many organisms exposed to ultraviolet radiation show increased fitness resulting from melanin pigmentation; this has been assumed to result in part from reduced UV-induced damage to DNA. However, to effectively test the hypothesis that melanin pigmentation reduces UV-induced DNA damage requires quantification of UV-specific DNA damage lesions following UV exposure under controlled conditions using individuals that vary in pigmentation intensity. We accomplished this using alpine genotypes of the freshwater microcrustacean Daphnia melanica , for which we quantified cyclobutane pyrimide dimers in DNA, a damage structure that can only be generated by UV exposure. For genotypes with carapace melanin pigmentation, we found that individuals with greater melanin content sustained lower levels of UV-induced DNA damage. Individuals with more melanin were also more likely to survive exposure to ecologically relevant levels of UV-B radiation. Parallel experiments with conspecific genotypes that lack carapace melanin pigmentation provide additional support for our conclusion that melanism protects individuals from UV-induced DNA damage. Finally, within-genotype comparisons with asexually produced clonal siblings demonstrate that melanin content influences DNA damage even among genetically identical individuals raised in the same environment.

Three-dimensional cellular automaton model for the destruction of brittle heterogeneous materials

The article investigates the evolution modes of cluster damage structure in brittle heterogeneous materials by using a three-dimensional probabilistic cellular automaton. By comparing the data of computer and physical experiments, there was established the essential role of the model parameter, which describes the intensity of the material destruction process under the influence of local overstress near the existing damage clusters - the probability of perimeter germination. The comparison of kinetic curves of damage accumulation and correlation functions showed that, depending on the probability value for damage cluster perimeter germination, two qualitatively different modes of evolution of damage accumulation process are observed. In this case, the best correspondence of correlation functions in model and physical experiment on pulsed electromagnetic emission is observed for perimeter germination probability values smaller than 0.2.