Physiological, Pathological and Pharmacological Interactions of Hydrogen Sulphide and Nitric Oxide in the Myocardium of Rats with Left Ventricular Hypertrophy

Left ventricular hypertrophy (LVH) is characterized by increased myocardium thickness due to increased oxidative stress and downregulation of cystathione γ lyase (CSE) endothelial nitric oxide synthase (eNOS). Upregulation of CSE by hydrogen sulphide (H2S) and ENOS by L-arginine can arrest the progression of LVH individually. The present study explored the combined treatment of H2S and NO in the progression of LVH, and demonstrated that the response is due to H2S, NO or formation of either new molecule in physiological, pathological, and pharmacological in vivo settings of LVH. Exogenous administration H2S+NO in LVH significantly reduced (all p < 0.05) systolic blood pressure (SBP) and mean arterial pressure (MAP), LV index, heart index and oxidative stress when compared to the LVH group. There was downregulation of CSE mRNA and eNOS in the heart, and exogenous administration of H2S+NO groups upregulated eNOS MRNA while CSE MRNA remained downregulated in the hearts of the LVH group. Similar trends were observed with concentrations of H2S and NO in the plasma and tissue. It can be concluded that combined treatment of LVH with H2S and NO significantly ameliorate the progression of LVH by attenuating systemic hemodynamic and physical indices, and by decreasing oxidative stress. Molecular expression data in the myocardium of LVH depicts that combined treatment upregulated eNOS/NO while it downregulated CSE/H2S pathways in in vivo settings, and it is always eNOS/NO pathways which play a major role.

Influence of meromixia on the distribution of zoobenthos and zooplankton in the salt soda lake Doroninskoe

Meromictic soda lakes are considered models of reservoirs of the Early Proterozoic. Lake Doroninskoe belongs to a rare type of moderately salty alkaline soda lake with a carbonate type of salinity and pronounced meromixia. Studies and publications on the zoobenthos of the lake are rare. In 2005–2007, studies of zoobenthos and zooplankton of the lake were carried out. Meromixia of the water column caused the stable presence of zooplankton only in a layer up to 4 m. The distribution of the taxonomic abundance, quantitative development and structure of zoobenthos in the lake corresponds to the stratification of the water column into mixolimnion, chemocline and monimolimnion. Bottom biotopes and water column layers deeper than 4 m were uninhabited, which is probably due to the lack of oxygen and high hydrogen sulphide content in the bottom water layers due to meromixia. A similar distribution of zooplankton in Lake Doroninskoe and its mesocosm model was revealed.

Effect of a Support on the Properties of Zinc Oxide Based Sorbents

We present the comparative analysis of three Zn-based sorbents for the process of sulphur removal from hot coal gas. The sorbents were prepared by a slurry impregnation of TiO2, SiO2 and Al2O3, resulting in complex, multiphase materials, with the dominant phases of Zn2TiO4, Zn2SiO4 and ZnAl2O4, respectively. We have analyzed the effect of supports on the phase composition, texture, reducibility and H2S sorption. We have found that the phase composition significantly influences the susceptibility of the investigated materials to reduction by hydrogen. Zn2TiO4 have been found to be the easiest to reduce which correlates with its ability to adsorb the largest amount of hydrogen sulphide—up to 4.2 gS/100 g—compared to the other sorbents, which absorb up to 2.2 gS/100 g. In the case of Zn2SiO4 and ZnAl2O4, this effect also correlates with reducibility—these sorbents have been found to be highly resistant to reduction by hydrogen and to absorb much less hydrogen sulphide. In addition, the capacity of ZnAl2O4 for H2S adsorption decreases in the subsequent work cycles—from 2.2 gS/100 g in the first cycle to 0.8 gS/100 g in the third one. Computational analysis on the DFT level has shown that these materials show different thermodynamic stability of sulphur sites within the unit cells of the sorbents. For Zn2TiO4 and Zn2SiO4, the adsorption is favorable in both the first and second layers of the former and only the top layer of the latter, while for zinc aluminate it is not favorable, which is consistent with the experimental findings.

Microbial Biogas Production From Pork Gelatine.

Dark fermentation of collagen (gelatine) results are shown in this research. The concentrations of applied gelatine were of VSS (volatile suspended solids) from 10 g VSS/L to 30 g VSS/L. The initial process pH was 5.5, depending on concentration reached pH values from 7.5 to 7.8 after 55 days. Although inoculum was heat-shocked in the case of 30 g VSS/L of collagen the process was hydrogenotrophic anaerobic digestion. In collagen concentration below 30 g VSS/L, hydrogen production was dominant only in the first 5 days of experiments. Then there also changed from dark fermentation into hydrogenotrophic methane production. In the case of optimal biogas production was due to accumulative production for a concentration of collagen 20 g VSS/L: 147.2 mL of hydrogen and 57.23 L of methane. In the case of optimal biogas production was due to accumulative production for a concentration of collagen 20 g VSS/L: 147.2 mL of hydrogen and 57.23 L of methane. The optimal hydrogen and methane yields were for concentration 10 g VSS/L (7.65 mL H2 /g VSS, and 3.49 L CH4/ g VSS). In 10 g VSS/L was also the lowest accumulated emission of hydrogen sulphide (10.3 mL of H2S), while the lowest yield was for 30 g VSS/L (0.44 mL H2S /g VSS). After a lag time, the hydrogen production and hydrogen sulphide grew with a specific ratio depending on concentration. Collagen, a protein with known amounts of sulphur allowed determining the origin of hydrogen sulphide in biogas. The hydrogen sulphide emission and sulphur added analysis proved that hydrogen sulphide origins in biogas from bacteria remains more than from substrate.