Diverse Functions of Tim50, a Component of the Mitochondrial Inner Membrane Protein Translocase

Mitochondria are essential in eukaryotes. Besides producing 80% of total cellular ATP, mitochondria are involved in various cellular functions such as apoptosis, inflammation, innate immunity, stress tolerance, and Ca²⁺ homeostasis. Mitochondria are also the site for many critical metabolic pathways and are integrated into the signaling network to maintain cellular homeostasis under stress. Mitochondria require hundreds of proteins to perform all these functions. Since the mitochondrial genome only encodes a handful of proteins, most mitochondrial proteins are imported from the cytosol via receptor/translocase complexes on the mitochondrial outer and inner membranes known as TOMs and TIMs. Many of the subunits of these protein complexes are essential for cell survival in model yeast and other unicellular eukaryotes. Defects in the mitochondrial import machineries are also associated with various metabolic, developmental, and neurodegenerative disorders in multicellular organisms. In addition to their canonical functions, these protein translocases also help maintain mitochondrial structure and dynamics, lipid metabolism, and stress response. This review focuses on the role of Tim50, the receptor component of one of the TIM complexes, in different cellular functions, with an emphasis on the Tim50 homologue in parasitic protozoan Trypanosoma brucei.     

Body composition and energy metabolism at rest

Indicators of body composition determined by bioelectrical impedance analysis (total body water, extracellular water mass, intracellular water mass, skeletal muscle mass, soft lean mass, protein, mineral mass, fat mass) were compared with the resting metabolic rate values (RMR). Studies were conducted in adults of different occupations, gender, age, weight and height. In total, the survey involved 180 people, residents of Nizhny Novgorod (70 men and 110 women) aged 17 to 63 years. It was shown that the normalization of the RMR with the parameters of the bioelectrical impedance analysis reduced the scatter of individual values. Comparison of the normalization results allowed us to estimate the interconnection between the RMR and the body composition. It was obtained statistical formulas for the relation of the RMR with the bioelectrical impedance. The greatest effect was found with the normalization of lean mass, as well as intracellular and extracellular water masses. The smallest effect was detected with the normalization of body fat. We obtained statistical formulas for the relation of the RMR with the bioelectrical impedance parameters. The highest correlations were found between the RMR and the lean mass, muscle mass and total water mass, the lowest with the fat mass. Role of the metabolically active tissue in energy metabolism, including the role of the intracellular and extracellular water is discussed. The results confirm the importance of the metabolically active tissues in the formation of the value of the RMR. Identified dependencies and high correlation between the RMR and the bioelectrical impedance parameters allows us to use these as a fast and convenient method for the approximate estimation of the RMR.     

Numerical Analysis of Stake Mark Induced Failure of a Rotor Shaft

In this paper, the stake mark induced failure of a generator rotor forging is analysed using finite element analyses in combination with a Cockroft & Latham failure model. Evidence is found from damage analysis that the rotor failed due to micro cracks and residual stresses induced by a double stake mark, which was located at a position subject to concentrated rotating‐bending stress amplitudes and torsional mean stress. The analysis presented here verifies the results of the damage analysis by showing that the stake mark configuration of the failed rotor was the most detrimental among a number of similar configurations. According to the finite element analysis, this stake mark configuration combines a high probability of inducing propagating sub‐surface micro‐cracks with considerable tensile residual stresses.     

Study of the silane modification of magnesium hydroxide and their effects on the flame retardant and tensile properties of high density polyethylene nanocomposites

The modification of magnesium hydroxide (MH) with triethoxy vinyl silane (TVS) was carried out via three different methods and the results are discussed with respect to their effect on the flame retardant and the tensile properties of high density polyethylene (HDPE) nanocomposites. Via a xylene suspension of MH and TVS, via a water suspension of MH and TVS, and via powder mixing of MH and TVS. It was found that in all three cases, Si O Mg bonds formed on the MH particles surface. Also, this silane modification induced a certain level of particle agglomeration, but without modifying their morphology or particle size. It was also found that the flame retardant properties of the HDPE nanocomposites did not improve because of the use of silane modified MH. During the flame retardant tests, all nanocomposites passed the UL‐94‐HB, but it was observed that the flame permanence time was longer when using modified MH. The tensile properties were negatively affected by the addition of unmodified MH; the nanocomposites became hard and brittle, with reduced flexibility. This negative effect was diminished when using silane modified MH. POLYM. COMPOS., 35:1060–1069, 2014. © 2013 Society of Plastics Engineers     

The influence of blood and/or hemostatic agent contamination on Micro-TBS to dentin

Aim: The purpose of this study was to evaluate the effects of blood contamination and hemostatic agent Ankaferd Blood Stopper (ABS: Ankaferd Drug Inc, Istanbul, Turkey) on the microtensile bond strength of a self-etching adhesive. Material and methods: Flat dentin surfaces were created from 40-M teeth and randomly divided to four groups according to contamination and adhesive procedure. The specimens of Group 1 are contaminated with blood; ABS was applied to the specimens of Group 2 after blood contamination and applied to the specimens of Group 3 without blood contamination. Group 4 is control group and self-etching adhesive was applied to all specimens. Teeth were restored with a nanohybrid composite. The specimens were sectioned to the beams and microtensile testing was carried out and the data were statistically analyzed with analysis of variance test. Tukey’s honestly significant difference post hoc test was also performed for multiple comparisons to compare subgroups. Results: Group 4 had the highest strength value, followed by Group 3, while Group 1, which contacts only with blood, had the lowest strength value. Conclusion: ABS has a negative effect on the bond strength of one-step self-etching adhesive system.     

A comparative study on monomer elution and cytotoxicity of different adhesive restoration materials

This study evaluated monomer release and cytotoxicity of different adhesive restoration materials used for dental restorations. The extracts (1, 2, and 7 days) of three types of adhesive dental restoration materials, [Quixfill (QF), Silorane Restorative (SR), and Ketac N 100 Restorative (KR)], and the adhesive resins, [XP Bond (XP), Silorane Primer (SP), Ketac N 100 Primer (KP), and Silorane Bond (SB)] were analyzed using high performance liquid chromatography/mass spectrometry (HPLC-MS). The cytotoxicity levels were determined at different time points (24, 48, and 72 h) of cell culture using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay. All adhesive resin materials showed monomer release at varying amounts with the highest release after 7 days. The lowest amount of release was observed in QF and the highest with KP. Bis-Phenol A (BPA) was not detected in SP and KR that contain bisphenol-A diglycidyl ether dimethacrylate (bis-GMA). Decamethylpenthasiloxane (D5) was not eluted from SR. Except for SR and QF, all other adhesive restoration materials showed different degrees of toxicity along with different monomer release kinetics. The correlation between the monomer release and cytotoxicity of the materials indicated that the cytotoxicity of the materials increased with the monomer release (Spearman’s rho correlation coefficient – r). The correlation after 48 h was statistically significant (r = ?0.342, p = 0.017).