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The W-4.9Ni-2.1Fe alloy with different addition of Y2O3 was prepared by high energy ball milling and spark plasma sintering techniques, the microstructure, mechanical property, friction and wear behavior of the high density alloy were investigated by the Rockwell hardness tester, X-ray diffractometer, reciprocating friction and wear tester, 3D profiler, etc. The results show that adequate doping of the trace Y2O3 can effectively inhibit the grain size, promote the γ-(Ni,Fe) bonding phase and tungsten particles uniformly distribute, increase the relative density, hardness, friction and wear properties. But the excessive Y2O3 addition can easily aggregate at grain boundary, weaken the inhibition effect, and decrease the mechanical and wear properties of the alloy. So the addition of Y2O3 should be appropriate. When the adding mass fraction of Y2O3 particles is 0.4%, the comprehensive performance of the alloy is the best.

The W–4.9Ni–2.1Fe–xDy2O3 heavy alloy was fabricated by high-energy ball milling and spark plasma sintering (SPS) technique, and the microstructure, mechanical and friction behavior and anti-corrosion ability were investigated by scanning electron microscope (SEM), Rockwell hardness tester, X-ray diffraction (XRD), reciprocating friction and wear tester, electrochemical station, etc. The results show that the trace Dy2O3 particles, which mainly distributes in the W–M (tungsten-matrix) interface and the tungsten matrix phase, can dramatically decrease the tungsten grain size and the amount of O and P impurities aggregating in the interface, promote the γ-(Ni, Fe) bonding phase and tungsten particles uniform distribution, and increase the relative density, hardness, and wear and corrosion resistance properties. But the excessive Dy2O3 addition can make the inhibition effect weaken, resulting in the decrease in the comprehensive performances of the alloy. So, the amount of Dy2O3 should be appropriate. When the adding amount of Dy2O3 particles is 0.7 wt%, the comprehensive performances of the heavy alloy are the best. [ABSTRACT FROM AUTHOR]

Coupled cellular respiration requires that ATP and ADP be efficiently exchanged between the cytosol and the mitochondrial matrix. When growth factors are withdrawn from dependent cells, metabolism is disrupted by a defect in ATP/ADP exchange across the mitochondrial membranes. Unexpectedly, we find that this defect results from loss of outer mitochondrial membrane permeability to metabolic anions. This decrease in anion permeability correlates with the changes in conductance properties that accompany closure of the voltage-dependent anion channel (also known as mitochondrial porin). Loss of outer membrane permeability (i) results in the accumulation of stored metabolic energy within the intermembrane space in the form of creatine phosphate, (ii) is prevented by the outer mitochondrial membrane proteins Bcl-[X.sub.L] and Bcl-2, and (iii) can be reversed by growth factor readdition. If outer membrane impermeability persists, the disruption of mitochondrial homeostasis culminates in loss of outer mitochondrial membrane integrity, cytochrome c redistribution, and apoptosis. The recognition that outer membrane permeability is regulated under physiological conditions has important implications for the understanding of bioenergetics and cell survival.

Objective. The aim of this study was to evaluate the feasibility, safety, and efficiency of single-port laparoscopic intragastric surgery by using a single-port device. Methods. The single-port device was introduced into the anterior wall of the stomach through 2.5-cm long abdominal and gastric incisions. Gastric mucosa resection and suturing (group 1) and mucosa resection by using staplers (group 2) were performed with 3 pigs in each group. Results. The time for setting up the intragastric ports ranged from 8 to 40 minutes (average 16.2 ± 12.2 minutes). The total surgery times for the 3 pigs in group 1 were 75, 45, and 38 minutes and for the other 3 pigs in group 2 were 80, 85, 70 minutes, respectively. Conclusion. A simple and stable intragastric surgery platform can be set up by using the single-port device placed into the stomach. This seems to be safe and feasible and may be a suitable alternative for humans. [ABSTRACT FROM PUBLISHER]