Impaired Mitophagy in Neurons and Glial Cells during Aging and Age-Related Disorders

Aging is associated with a decline in cognitive function, which can partly be explained by the accumulation of damage to the brain cells over time. Neurons and glia undergo morphological and ultrastructure changes during aging. Over the past several years, it has become evident that at the cellular level, various hallmarks of an aging brain are closely related to mitophagy. The importance of mitochondria quality and quantity control through mitophagy is highlighted by the contribution that defects in mitochondria–autophagy crosstalk make to aging and age-related diseases. In this review, we analyze some of the more recent findings regarding the study of brain aging and neurodegeneration in the context of mitophagy. We discuss the data on the dynamics of selective autophagy in neurons and glial cells during aging and in the course of neurodegeneration, focusing on three mechanisms of mitophagy: non-receptor-mediated mitophagy, receptor-mediated mitophagy, and transcellular mitophagy. We review the role of mitophagy in neuronal/glial homeostasis and in the molecular pathogenesis of neurodegenerative disorders, such as Parkinson’s disease, Alzheimer’s disease, and other disorders. Common mechanisms of aging and neurodegeneration that are related to different mitophagy pathways provide a number of promising targets for potential therapeutic agents.     

Utilization of multiwalled boron nitride nanotubes for the reinforcement of lightweight aluminum ribbons

Carbon nanotubes (CNT) are extremely sensitive to environmental gases. However, detection of mixture gas is still a challenge. Here, we report that 10 ppm of carbon monoxide (CO) and ammonia (NH₃) can be electrically detected using a carboxylic acid-functionalized single-walled carbon nanotubes (C-SWCNT). CO and NH₃ gases were mixed carefully with the same concentrations of 10 ppm. Our sensor showed faster response to the CO gas than the NH₃ gas. The sensing properties and effect of carboxylic acid group were demonstrated, and C-SWCNT sensors with good repeatability and fast responses over a range of concentrations may be used as a simple and effective detection method of CO and NH₃ mixture gas.     

DRIFT,XPS and XAS Investigation of Au–Ni/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Synergetic Catalyst for Allylbenzene Isomerization

Au/Al₂O₃ and Ni/Al₂O₃ prepared by deposition-precipitation and impregnation methods, respectively, and Au–Ni/Al₂O₃ prepared by impregnation of the Au/Al₂O₃ system with nickel have been studied by physicochemical methods. The catalysts were tested in allylbenzene isomerization at 443 K. The isomerization on Au/Al₂O₃ proceeds with a rather low rate, while monometallic Ni/Al₂O₃ is inactive. Unlike monometallic catalysts, Au–Ni/Al₂O₃ demonstrates a strong synergetic effect: the isomerization rate on the bimetallic sample exceeds the sum of the rates over the individual metals by an order of magnitude. The catalysts structure was estimated by XPS, DRIFT, and XAS techniques. It was revealed that nickel in Au–Ni/Al₂O₃ and Ni/Al₂O₃ exist as Ni²⁺ cations with the coordination state close to that in the precursor, gold in Au/Al₂O₃ exist as Au⁰ nanoclusters, whereas the Au⁰ nanoclusters co-exist with Au³⁺ cations in the bimetallic Au–Ni/Al₂O₃ sample. Reasons of the synergetic catalytic effect for Au–Ni/Al₂O₃ are discussed in terms of the formation of new positively charged Au catalytic centers.     

Computer simulation of microstructure effect on ferroelectric ceramic fracture

Computer simulation the PZT ceramics fracture due to growing macrocrack is developed. AS toughening mechanism it's considered the phase transformation of the secondary phase inclusions caused by the crack stress state. Crack draging by domain boundaries is discussed.     

液晶显示器的优化与模型试验

利用专门软件对LCD进行模型试验和优化是一项普遍采用的技术，并且是开发现代LCD结构和了解其工作机理的强有力工具。     

Quantum-chemical calculations of the effect of cycloaliphatic groups in α-diimine and bis(imino)pyridine ethylene polymerization precatalysts on their stabilities with respect to deactivation reactions

For the first time, it is attempted to interpret an experimentally found enhancing effect of cycloaliphatic substituents in aromatic rings of Ni^II- and Pd^II-α-diimine and Fe^II-bis(imino)pyridine ethylene polymerization precatalysts on their catalytic activities at elevated temperatures (60-80 °C), using quantum chemical density functional theory calculations of relative stabilities of the complexes with respect to different deactivation processes, including thermal decomposition and one-electron reduction. It was shown that the effect correlates with the calculated higher thermal stabilities of cycloalkyl-substituted Fe^II-, Ni^II- and Pd^II-complexes as compared to the corresponding alkyl-substituted ones. Ni^II- and Pd^II-α-diimine complexes with cycloalkyl substituents are shown to be more stable than their alkyl-substituted analogues with respect to both thermal decomposition and one-electron reduction. The averaged difference of the thermal decomposition energies between the complexes with cycloaliphatic substituents on one side and aliphatic ones on the other side is ∼2.3 kcal/mol, corresponding to ∼30 times lower equilibrium constant of the thermal decomposition reaction for the cycloalkyl-containing complexes. For the Fe^II- and Pd^II-complexes, the thermal stability correlates with the calculated overlap population of the metal-nitrogen bonds. It was shown that the structure of o-substituents (cycloalkyls vs. alkyls) in the phenyl rings of the ligands does not affect the reaction energies for the transformation reactions of the precatalysts into their corresponding active catalytic cationic forms.     

Kinetics and mass transfer in hydroformylation—bulk or film reaction?

The kinetics of a gas–liquid reaction, alkene hydroformylation was studied in the presence of a homogeneous catalyst in a pressurised laboratory‐scale semibatch reactor. Hydroformylation of propene to isobutyraldehyde and n‐butyraldehyde was carried out at 70–115°C and 1–15 bar pressure in 2,2,4‐trimethyl‐1,3‐pentanediol monoisobutyrate solvent with rhodium catalyst using the ligands cyclohexyl diphenylphosphine. In order to evaluate the influence of mass transfer, experiments were made using varied stirring rate from 100 to 1000 rpm at 100°C and 10 MPa syngas pressure. Only at higher stirrings rates, the reaction took place in the kinetic regime. A reactor model was developed comprising both complex kinetics and liquid‐phase mass transfer. The model was based on the theory of reactive films. The model is able to predict under which circumstances the hydroformylation process is affected by liquid‐phase diffusion of the reactants. Experimental data and model simulations are presented for the hydroformylation of propene in the presence of a homogeneous rhodium catalyst.     

Effective viscosity of puller-like microswimmers: a renormalization approach

Effective viscosity (EV) of suspensions of puller-like microswimmers (pullers), for example Chlamydamonas algae, is difficult to measure or simulate for all swimmer concentrations. Although there are good reasons to expect that the EV of pullers is similar to that of passive suspensions, analytical determination of the passive EV for all concentrations remains unsatisfactory. At the same time, the EV of bacterial suspensions is closely linked to collective motion in these systems and is biologically significant. We develop an approach for determining analytical EV estimates at all concentrations for suspensions of pullers as well as for passive suspensions. The proposed methods are based on the ideas of renormalization group (RG) theory and construct the EV formula based on the known asymptotics for small concentrations and near the critical point (i.e. approaching dense packing). For passive suspensions, the method is verified by comparison against known theoretical results. We find that the method performs much better than an earlier RG-based technique. For pullers, the validation is done by comparing them to experiments conducted on Chlamydamonas suspensions.