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Microextrusion is becoming increasingly important for the manufacturing of microcomponents. However, this reduction in scale to a microlevel means that the influence of friction and the need for suitable lubrication are greatly increased. This study therefore looks at the use of a low-friction and highly wear resistant Graphit-ic coating on the mold-forming section of a microextrusion mold, this coating being applied by a closed-field unbalanced magnetron sputter ion plating technique. A microcup of CuZn33 brass alloy was then extruded, with a wall thickness of 0.45 mm, outside diameter of 2.9 mm, and an internal diameter of 2 mm. The experimental results in which extrusion uses the mold coating with Graphit-ic film are compared against the experimental results in which extrusion uses the mold uncoating with Graphit-ic film. This showed that the load was decreased a lot and the self-lubricating solid coating facilitates a smooth extrusion process. As the extrusion rate was quite high, smoothed particle hydrodynamics method simulations of the extrusion process were conducted, these being then compared with the experimental results. These result showed that the SPH simulation can be applied to show the deformation of materials and predict the load trend.

According to the characteristics of aluminum alloy extrusion, which means severe large deformation, thermo-dynamics coupled, and a dead zone at the front of billet, a finite volume method (FVM) based on Eulerian description was adopted to simulate the extrusion deformation of complex profile grade 3. With FVM, the traditional problems and difficulties, such as dead zone faced by rigid-plastic FEM, and grid distortion and remeshing faced by Lagrangian described finite deformation elastic-plastic FEM, can be effectively avoided. During the simulation, Eulerian described FVM is used to simulate the flow of billet, Lagrangian described FEM is used to simulate the deformation and stress of mold, and explicit dynamic contact algorithm is used to simulate the counteraction between the billet and the mold. In order to improve the efficiency of calculation, appropriate minimum size of FV grid and maximum number of FV elements are ascertained based on the good balance between the accuracy and speed of simulation. A series of thermo-constructional-frictional models are set up according to different deforming temperatures. Elaborate deformation results including exactly distributions of metal flow, stress, strain, temperature, and density in both plastic and plastic-elastic zones are obtained, which is a good base for the future optimization of process and mold parameters. [ABSTRACT FROM AUTHOR]

Abstract: The effect of methylene blue/TiO2 nanocomposites on Staphylococcus aureus was evaluated by a LKB-2277 Bioactivity Monitor at 37.0°C. By analyzing the thermogenic power–time curves, kinetic parameters such as the growth rate constant (k), the maximum heat power of growth phase (P m), generation time (t G) and the inhibitory ratio (I) were determined. The k and P m decrease while t G and I increases with increasing concentrations of the methylene blue/TiO2 nanocomposites added into the microbe suspension. Both k and I have linear correlations with the concentration of the methylene blue/TiO2 nanocomposites. The effect of the methylene blue sensitized-TiO2 nanocomposites on the cell damage of S. aureus was investigated by microscopic method. [Copyright &y& Elsevier]

Objectives: The aim of this study was to explore the role of integrin alpha V (ITGAV) and the related long noncoding RNA-microRNA-messenger RNA competing endogenous RNA (lncRNA-miRNA-mRNA ceRNA) network in the development and prognosis of cancers, especially gastric cancer (GC), through bioinformatic analysis., Methods: Pan-cancer and GC data were collected from the UCSC Xena website, and validation datasets were obtained from the Gene Expression Omnibus (GEO). R (version 3.6.3), GraphPad Prism 8, and SPSS 23.0 software were used to analyze data and prepare figures., Results: The expression of ITGAV in tumor tissues was higher than that of normal tissues in ten cancer types. A lower expression of ITGAV in five tumors (CESC, LGG, LIHC, MESO, and STAD) predicted better patient prognosis. In GC, the mRNA and protein expression of ITGAV in tumor tissues was higher than that of normal tissues. Patients with high ITGAV expression had poor prognosis and clinical characteristics, including worse grades and more advanced stages. Patients with higher ITGAV expression had higher immune and stromal scores and lower purity (P<0.05). In addition, seven miRNAs were found that were negatively correlated with ITGAV expression through the website; high expression of these miRNAs indicated a better prognosis. Using this correlation, the authors built the lncRNA-miRNA-ITGAV ceRNA network, to predict the prognosis of GC., Conclusions: This study showed that ITGAV could be considered a prognostic factor for GC, and an lncRNA-miRNA-ITGAV ceRNA network was built to promote the exploration of the mechanism and prognosis of GC., Competing Interests: None., (IJCEP Copyright © 2022.)

The interaction between pharmaceutical and protein is an important pharmacokinetic characteristic. Most kinds of drugs must reach the receptor to perform the pharmacological function by plasma. Albumins can serve as a depot protein and a transport protein for numerous endogenous and exogenous compounds. It is of great significance to investigate the binding interaction between albumin and drugs, since it can not only help understand the transportation and distribution of drugs but also elucidate the mechanism. Under the physiological condition of body, the interaction between levofloxacin (LVFX) and bovine serum albumin (BAS) was investigated by fluorescence spectra and ultraviolet absorbance (UV) spectra based on liquid drop. The experimental results showed that LVFX quenches the fluorescence of BAS by forming a LVFX-BSA complex. According to Lineweaver-Burk equation, the apparent binding constants (K(LB)) between LVFX and BSA were 1.694 9 x 10(5) L x mol(-1) (291 K) and 2.881 0 x 10(5) L x mol(-1) (310 K), and the binding sites (n) were 0.884 9 (291 K) and 0.808 9 (310 K). Thermodynamic parameters could be evaluated from the thermodynamic second law, with deltaH (enthalpy) being 20.94 kJ mol(-1) and deltaS (entropy) being 172.1 J x mol(-1). According to the relation between thermodynamic parameters and the interaction force, LVFX depended principally on the hydrophobic interaction to bind with BSA. The results showed that the quenching belonged to static fluorescence quenching with non-radiation energy transfer happening within single molecule. The binding locality was an area 2.68 nm away from tryptonphan residue-212 in BAS according to Forster's non-radiation energy transfer mechanism. The conformational changes of BSA were evaluated by measuring the synchronous fluorescence intensity of protein amino acid residues, both before and after the addition of LVFX. A slightly stronger blue-shift of tryptophan fluorescence upon the addition of drug was observed, and the emission maximum of tyrosine kept its position. It was suggested that the environments of tryptophan residues in pure albumin solution are relatively polar. Binding of LVFX changes the environments to apolar ones. The shift in polarity is brought about by confirmation changes due to the interaction between albumin and ligand molecule.