Investigation of Influence of Compensator Element on the Structure and Properties of the Alloy AK12

Изучена возможность использования алюминия марки А7 вместо А8 для удешевления дисков автомобильных колес, изготавливаемых из сплава АК12 литьем под низким давлением. Исследована микроструктура и свойства шести опытных сплавов. Установлено, что использование первичного алюминия А7 вместо А8 возможно при введении элемента- компенсатора – марганца – в количестве не более 0,20–0,25 % масс. при содержании железа не более 0,20–0,25 % масс., т.е. соотношение Fe : Mn должно быть равно 1 : 1. Получены требуемые ГОСТ 50511-93 механические свойстваPossibility of using of aluminum A7 instead of A8 to reduce the cost automobile wheel discs, made from alloy AK12 by casting under low pressure is studied. The microstructure and properties of six experimental alloys are investigated. It is found that use of primary aluminum A7 instead of A8 is possible at insertion of a compensator element-manganese in an amount of not more than 0.20–0.25 wt %. at the content of iron is not more than 0.20-0.25 wt. %, that is ratio Fe: Mn has to be equal 1: 1. The mechanical properties demanded GOST 50511-93 are receive

Investigation of Influence of Compensator Element on the Structure and Properties of the Alloy AK12

Изучена возможность использования алюминия марки А7 вместо А8 для удешевления дисков автомобильных колес, изготавливаемых из сплава АК12 литьем под низким давлением. Исследована микроструктура и свойства шести опытных сплавов. Установлено, что использование первичного алюминия А7 вместо А8 возможно при введении элемента- компенсатора – марганца – в количестве не более 0,20–0,25 % масс. при содержании железа не более 0,20–0,25 % масс., т.е. соотношение Fe : Mn должно быть равно 1 : 1. Получены требуемые ГОСТ 50511-93 механические свойстваPossibility of using of aluminum A7 instead of A8 to reduce the cost automobile wheel discs, made from alloy AK12 by casting under low pressure is studied. The microstructure and properties of six experimental alloys are investigated. It is found that use of primary aluminum A7 instead of A8 is possible at insertion of a compensator element-manganese in an amount of not more than 0.20–0.25 wt %. at the content of iron is not more than 0.20-0.25 wt. %, that is ratio Fe: Mn has to be equal 1: 1. The mechanical properties demanded GOST 50511-93 are receive

Myeloperoxidase modulates human platelet aggregation via actin cytoskeleton reorganization and store-operated calcium entry

Summary Myeloperoxidase (MPO) is a heme-containing enzyme released from activated leukocytes into the extracellular space during inflammation. Its main function is the production of hypohalous acids that are potent oxidants. MPO can also modulate cell signaling and inflammatory responses independently of its enzymatic activity. Because MPO is regarded as an important risk factor for cardiovascular diseases associated with increased platelet activity, we studied the effects of MPO on human platelet functional properties. Laser scanning confocal microscopy was used to reveal carbohydrate-independent MPO binding to human platelet membrane. Adding MPO to platelets did not activate their aggregation under basal conditions (without agonist). In contrast, MPO augmented agonist-induced platelet aggregation, which was not prevented by MPO enzymatic activity inhibitors. It was found that exposure of platelets to MPO leads to actin cytoskeleton reorganization and an increase in their elasticity. Furthermore, MPO evoked a rise in cytosolic Ca2+ through enhancement of store-operated Ca2+ entry (SOCE). Together, these findings indicate that MPO is not a direct agonist but rather a mediator that binds to human platelets, induces actin cytoskeleton reorganization and affects the mechanical stiffness of human platelets, resulting in potentiating SOCE and agonist-induced human platelet aggregation. Therefore, an increased activity of platelets in vascular disease can, at least partly, be provided by MPO elevated concentrations

New Application of the Commercially Available Dye Celestine Blue B as a Sensitive and Selective Fluorescent “Turn-On” Probe for Endogenous Detection of HOCl and Reactive Halogenated Species

Hypochlorous acid (HOCl) derived from hydrogen peroxide and chloride anion by myeloperoxidase (MPO) plays a significant role in physiological and pathological processes. Herein we report a phenoxazine-based fluorescent probe Celestine Blue B (CB) that is applicable for HOCl detection in living cells and for assaying the chlorinating activity of MPO. A remarkable selectivity and sensitivity (limit of detection is 32 nM), along with a rapid “turn-on” response of CB to HOCl was demonstrated. Furthermore, the probe was able to detect endogenous HOCl and reactive halogenated species by fluorescence spectroscopy, confocal microscopy, and flow cytometry techniques. Hence, CB is a promising tool for investigating the role of HOCl in health and disease and for screening the drugs capable of regulating MPO activity

Effect of alpha-lactalbumin and lactoferrin oleic acid complexes on chromatin structural organization

This work focuses on the study of multimeric alpha-lactalbumin oleic acid and lactoferrin oleic acid complexes. The purpose of the research is to study possible mechanisms involved in their pro-apoptotic activities, as seen in some tumor cell cultures. Complexes featuring oleic acid (OA) with human alpha-lactalbumin (hAl) or with bovine alpha-lactalbumin (bAl), and human lactoferrin (hLf) were investigated using small-angle neutron scattering (SANS). It was shown that while alpha-lactalbumin protein complexes were formed on the surface of polydisperse OA micelles, the lactoferrin complexes comprised a monodisperse system of nanoscale particles. Both hAl and hLf complexes appeared to interact with the chromatin of isolated nuclei affecting chromatin structural organization. The possible roles of these processes in the specific anti-tumor activity of these complexes are discussed