Cholecalciferol administration to vitamin D-deficient chicks produces, 24 h after treatment, a specific increase of the phosphatidylcholine content in the intestinal mitochondrial inner membrane plus matrix fraction without changes in its proportion in the outer membrane. The ratio of unsaturated/saturated fatty acids in the outer membrane phosphatidylcholine was increased by that treatment. The inner membrane plus matrix presents a decrease of 16:1 in phosphatidylethanolamine and 18:0 in the phosphatidylcholine fraction. Cardiolipin shows the largest change in the ratio of unsaturated/saturated fatty acids predominantly by an increase in the linoleic acid. The present data suggest that phosphatidylcholine and fatty acids modifications in both mitochondrial subfractions caused by vitamin D3 might have some role in the intestinal mitochondrial Ca transport. 相似文献
International Journal of Peptide Research and Therapeutics - The progressive damage of human articular cartilage is associated with loss of integrity of its extracellular matrix components. Their... 相似文献
Nickel is harmful to humans, being both carcinogenic and allergenic. However, the mechanisms of this toxicity are still unresolved. We propose that Ni(II) ions disintegrate proteins by hydrolysis of peptide bonds preceding the Ser/Thr‐Xaa‐His sequences. Such sequences occur in nuclear localization signals (NLSs) of human phospholipid scramblase 1, Sam68‐like mammalian protein 2, and CLK3 kinase. We performed spectroscopic experiments showing that model nonapeptides derived from these NLSs bind Ni(II) at physiological pH. We also proved that these sequences are prone to Ni(II) hydrolysis. Thus, the aforementioned NLSs may be targets for nickel toxicity. This implies that Ni(II) ions disrupt the transport of some proteins from cytoplasm to cell nucleus. 相似文献
Biodecolorization and biodegradation of azo dyes are a challenge due to their recalcitrance and the characteristics of textile effluents. This study presents the use of Halomonas sp. in the decolorization of azo dyes Reactive Black 5 (RB5), Remazol Brilliant Violet 5R (RV5), and Reactive Orange 16 (RO16) under high alkalinity and salinity conditions. Firstly, the effect of air supply, pH, salinity and dye concentration was evaluated. Halomonas sp. was able to remove above 84% of all dyes in a wide range of pH (6–11) and salt concentrations (2–10%). The decolorization efficiency of RB5, RV5, and RO16 was found to be ≥ 90% after 24, 13 and 3 h, respectively, at 50 mg L−1 of dyes. The process was monitored by HPLC-DAD, finding a reduction of dyes along the time. Further, Halomonas sp. was immobilized in volcanic rocks and used in a packed bed reactor for 72 days, achieving a removal rate of 3.48, 5.73, and 8.52 mg L−1 h−1, for RB5, RV5 and RO16, respectively, at 11.8 h. The study has confirmed the potential of Halomonas sp. to decolorize azo dyes under high salinity and alkalinity conditions and opened a scope for future research in the treatment of textile effluents.
Strain MG, isolated from an acidic pond sediment on the island of Milos (Greece), is proposed as a novel species of ferrous iron- and sulfur-oxidizing Acidithiobacillus. Currently, four of the eight validated species of this genus oxidize ferrous iron, and strain MG shares many key characteristics with these four, including the capacities for catalyzing the oxidative dissolution of pyrite and for anaerobic growth via ferric iron respiration. Strain MG also grows aerobically on hydrogen and anaerobically on hydrogen coupled to ferric iron reduction. While the 16S rRNA genes of the iron-oxidizing Acidi-thiobacillus species (and strain MG) are located in a distinct phylogenetic clade and are closely related (98–99% 16S rRNA gene identity), genomic relatedness indexes (ANI/dDDH) revealed strong genomic divergence between strain MG and all sequenced type strains of the taxon, and placed MG as the first cultured representative of an ancestral phylotype of iron oxidizing acidithiobacilli. Strain MG is proposed as a novel species, Acidithiobacillus ferrianus sp. nov. The type strain is MGT (= DSM 107098T = JCM 33084T). Similar strains have been found as isolates or indicated by cloned 16S rRNA genes from several mineral sulfide mine sites.
Calcium sulfoaluminate‐based cements (CSA) are proposed as a cement alternative with a low carbon footprint. The nature of CSA makes the manufacturing process to require lower temperature, less fuel, and less calcite. However, it requires aluminum oxide, Al2O3, which would be originated from bauxite and bauxite‐derived wastes, and sulfur, coming from calcium sulfate or elemental sulfur. An eco‐efficiency assessment of CSA cements, benchmarked against the conventional Portland cement, has been performed following the principles of ISO 14045 on eco‐efficiency for a total of 240 CSA clinker production scenarios. The eco‐efficiency indicator relates an environmental indicator with a product system value indicator, and it is calculated for each of the studied parameters: bauxite geographical origin, the fuel used for clinkering, the source of sulfur, and the composition of the clinker. Eco‐efficiency results show a strong dependence on the origin of bauxite, while other parameters, as the fuel used, its content in sulfur, or the supply of other raw materials, are of less importance. The most eco‐efficient solutions are those with certain closeness to bauxite sources. To achieve global solutions, that is, cement‐making based on CSA independently of the origin of the raw materials, the amount of bauxite needs to be minimized and CSA composition restricted. 相似文献
The effect of Lactobacillus rhamnosus CRL1505 (Lr) on macrophages (Ma) and dendritic cells (DC) in the orchestration of anti-pneumococcal immunity was stud 相似文献
Vegetation History and Archaeobotany - The Eemian interglacial represents a natural experiment on how past vegetation with negligible human impact responded to amplified temperature changes... 相似文献
In this work, we review the physiological and molecular mechanisms that allow vascular plants to perform photosynthesis in extreme environments, such as deserts, polar and alpine ecosystems. Specifically, we discuss the morpho/anatomical, photochemical and metabolic adaptive processes that enable a positive carbon balance in photosynthetic tissues under extreme temperatures and/or severe water‐limiting conditions in C3 species. Nevertheless, only a few studies have described the in situ functioning of photoprotection in plants from extreme environments, given the intrinsic difficulties of fieldwork in remote places. However, they cover a substantial geographical and functional range, which allowed us to describe some general trends. In general, photoprotection relies on the same mechanisms as those operating in the remaining plant species, ranging from enhanced morphological photoprotection to increased scavenging of oxidative products such as reactive oxygen species. Much less information is available about the main physiological and biochemical drivers of photosynthesis: stomatal conductance (gs), mesophyll conductance (gm) and carbon fixation, mostly driven by RuBisCO carboxylation. Extreme environments shape adaptations in structures, such as cell wall and membrane composition, the concentration and activation state of Calvin–Benson cycle enzymes, and RuBisCO evolution, optimizing kinetic traits to ensure functionality. Altogether, these species display a combination of rearrangements, from the whole‐plant level to the molecular scale, to sustain a positive carbon balance in some of the most hostile environments on Earth. 相似文献