CoQ10 supplementation rescues nephrotic syndrome through normalization of H2S oxidation pathway

Nephrotic syndrome (NS), a frequent chronic kidney disease in children and young adults, is the most common phenotype associated with primary coenzyme Q₁₀ (CoQ₁₀) deficiency and is very responsive to CoQ₁₀ supplementation, although the pathomechanism is not clear. Here, using a mouse model of CoQ deficiency-associated NS, we show that long-term oral CoQ₁₀ supplementation prevents kidney failure by rescuing defects of sulfides oxidation and ameliorating oxidative stress, despite only incomplete normalization of kidney CoQ levels and lack of rescue of CoQ-dependent respiratory enzymes activities. Liver and kidney lipidomics, and urine metabolomics analyses, did not show CoQ metabolites. To further demonstrate that sulfides metabolism defects cause oxidative stress in CoQ deficiency, we show that silencing of sulfide quinone oxido-reductase (SQOR) in wild-type HeLa cells leads to similar increases of reactive oxygen species (ROS) observed in HeLa cells depleted of the CoQ biosynthesis regulatory protein COQ8A. While CoQ₁₀ supplementation of COQ8A depleted cells decreases ROS and increases SQOR protein levels, knock-down of SQOR prevents CoQ₁₀ antioxidant effects. We conclude that kidney failure in CoQ deficiency-associated NS is caused by oxidative stress mediated by impaired sulfides oxidation and propose that CoQ supplementation does not significantly increase the kidney pool of CoQ bound to the respiratory supercomplexes, but rather enhances the free pool of CoQ, which stabilizes SQOR protein levels rescuing oxidative stress.     

Photochemical carbon-sulfur bond cleavage in some alkyl and benzyl sulfides

Irradiation (254 nm) of five alkyl and benzyl ethyl sulfides causes efficient (Φ_r 0.27-0.90) homolytic cleavage of the C-S bond. Of the resulting fragments, thiyl radicals mainly couple, while alkyl radicals abstract hydrogen, disproportionate or couple when stabilized (benzyl). Selective trapping of either of the two types of radicals occurs in the presence of nucleophilic (methyl vinyl ether and 1-hexene) and, respectively, electrophilic (acrylonitrile) alkenes. When an easily oxidized radical is formed, e.g. cumyl, secondary electron transfer leads to the corresponding cation.     

Sulfur cycling and seagrass (Posidonia oceanica) status in carbonate sediments

Sulfur cycling was investigated in carbonate-rich and iron-poor sediments vegetated with Posidonia oceanica in oligotrophic Mediterranean around Mallorca Island, Spain, to quantify sulfate reduction and pools of sulfide in seagrass sediments. The oxygen penetration depth was low (< 4.5 mm) and sulfate reduction rates were relatively high (0.7–12 mmol m^–2d^–1). The total pools of reduced sulfides were remarkably low (< 5 mol S m^–2) indicating a fast turnover of reduced sulfides in these iron-poor sediments. The sulfate reduction rates were generally higher in vegetated compared to bare sediments possible due to enhanced sedimentation of sestonic material inside the seagrass meadows. The sulfate reduction rates were positively correlated with the seasonal variation in water temperature and negatively correlated with the shoot density indicating that the microbial activity was controlled by temperature and release of oxygen from the roots. The pools of reduced sulfides were low in these iron-poor sediments leading to high oxygen consumption for reoxidation. The sediments were highly anoxic as shown by relatively low oxygen penetration depths (< 4.5 mm) in these low organic sediments. The net shoot recruitment rate was negative in sediments enriched with organic matter, suggesting that organic matter enrichment may be an important factor for seagrass status in these iron-depleted carbonate sediments.     

Sustainability in metal mining: from exploration, over processing to mine waste management

Metal mining or more general mineral mining, is the base industry of the economic wealth and development of numerous countries. However, mining has a negative reputation due to the complex problems of environmental contamination like SO₂ and CO₂ emissions and acid mine drainage (AMD) formation, which endangers vital limited resources, like air, water, and soils. This view paper highlights the environmental problems of todays metal mining operations and explores possibilities of future more sustainable mining operations with focus on enhanced and optimized metal recovery systems in combination with a minimization of the environmental impact. These changes depend on a change in mentality and in the mining operation process, which can nowadays yet be observed in some modern mining operations. The goal for the future will be to implement these changes as standard for all future mining operations.     

Synthesis and characterization of 5,5′-dibromo-2,2′-dipyridyl disulfide and some of its derivatives: X-ray structure of 5,5′-dibromo-2,2′-dipyridyl disulfide and bis(5-bromopyridine-2-ylthio) methane

Synthesis and characterization of 5,5′-dibromo-2,2′-dipyridyl disulfide and some of its derivatives under mild reaction conditions is described. A series of some novel synthetically important symmetrical/unsymmetrical bromo substituted pyridyl alkyl/aryl sulfur compounds have been easily synthesized from a variety of alkyl halides, using NaBH₄ in moderate to good yields. The important features of this protocol are strong base-free, operational simplicity, short reaction time and high yield. The synthesized compounds are characterized with the help of elemental analysis, IR, ¹H NMR, ¹³C NMR and mass spectral data (in representative cases). X-ray crystal structure analysis of 5,5′-dibromo-2,2′-dipyridyl disulfide (1) and bis(5-bromopyridine-2-ylthio) methane (2a) have been carried out to establish their molecular structure. Compound (1) and (2a) are monoclinic and crystallizes into P2₁/n and C2/c space group, respectively.     

义齿口臭的相关因素研究

目的:探讨义齿口臭的的相关因素。方法:选择62例无牙周疾病且全身健康(心血管系统疾病除外)的上颌义齿修复者,鼻闻法检查口臭程度(OR值),使用便携式口气测量仪(halitosis)测量VSCs量,记录义齿使用时间、菌斑指数(plaque index,PLI)。结果:Spearman相关分析法显示口臭值与义齿使用时间、PLI存在正相关(r=0.73,r=0.52,P<0.01),义齿口臭OR值与VSCs量存在正相关(r=0.62,p<0.01),义齿使用时间与PLI也有一定的相关性(r=0.259,P<0.05)。结论:口臭值、VSCs量与聚甲基丙烯酸脂基托义齿使用时间、PLI均有关系,义齿口臭的气体成份不完全同于其它口源性口臭。     

A generally synthetic route to semiconducting metal sulfide nanocrystals by using corresponding metal powder and cysteine as metallic and sulfuric sources, respectively

The economical and large-scale preparations of metallic sulfides nanocrystals (NCs) would determine their practical industrial application. In this contribution, a series of sulfides NCs such as ZnS, CdS, PbS, Cu_xS, MnS and Bi₂S₃, have been harvested by thermolysis of a single source metal cysteinate obtained conveniently from the reaction between metal powder and cysteine in aqueous environment and constant atmosphere in glassware. The characterizations including TEM, XRD, UV-Vis, FT-IR, TG-DSC, EDX and BET confirmed that the as-synthesized products are from the decomposition of metal cysteinate, of nanoscale in size, and of mesoporous materials. The generation, low cost and benign environment made this route technologically and scientifically interesting for the preparation of metallic sulfides NCs.