304 research outputs found

    Synthesis and catalytic properties of copper(II) 1-aryl-5-benzothiazolylformazanates

    Get PDF
    New copper(II) benzothiazolylformazane complexes were synthesized and immobilized on AN-18 anion exchanger. The influence of the composition of the coordination core of copper(II) benzthiazolylformazanates and temperature on their catalytic properties in decomposition of H2O2 and oxidation of Na2S in aqueous solution was studied

    Synthesis and spectroscopic features of iron(II) 1-aryl-5-benzothiazol-2- ylformazanates

    Get PDF
    New iron(II) coordination compounds with 1-aryl-5-(benzothiazol-2-yl) formazans were prepared. Their compositions and structures were determined by electronic spectroscopy, mass spectrometry, single crystal X-ray diffraction analysis, and magnetochemical measurements. © 2008 Pleiades Publishing, Ltd.Russian Foundation for Basic Researc

    Cutting Edge Geometry Effect on Plastic Deformation of Titanium Alloy

    Get PDF
    The paper presents experimental studies of ОТ4 titanium alloy machining with cutting edges of various geometry parameters. Experiments were performed at a low speed by the scheme of free cutting. Intensity of plastic shear strain was set for defining of cutting edge geometry effect on machining. Images of chip formed are shown. Estimation of strain magnitude was accomplished with digital image correlation method. Effect of rake angle and cutting edge angle has been studied. Depth of deformed layer and the area of the plastic strain is determine. Results showed that increasing the angle of the cutting edge inclination results in a change the mechanism of chip formation

    Design and operation of a Rayleigh Ohnesorge Jetting Extensional Rheometer (ROJER) to study extensional properties of low viscosity polymer solutions

    Get PDF
    The Rayleigh Ohnesorge Jetting Extensional Rheometer (ROJER) enables measurement of very short relaxation times of low viscosity complex fluids such as those encountered in ink-jet printing and spraying applications. This paper focuses on the design and operation of the ROJER. The performance of two nozzle designs are compared using Newtonian fluids alongside a study using computational fluid dynamics (CFD). Subsequently a disposable nozzle is developed that overcomes issues of blockage and cleaning. The operability of this design is subject to a focused study where low viscosity polymer solutions are characterised. The test fluid materials are ethyl hydroxy-ethyl cellulose (EHEC) and poly ethylene oxide (PEO) mixed with water/glycerol solutions. Results obtained by the disposable nozzle are encouraging, paving the way for a more cost-efficient and robust ROJER setup

    Cutting Edge Geometry Effect on Plastic Deformation of Titanium Alloy

    Get PDF
    The paper presents experimental studies of ОТ4 titanium alloy machining with cutting edges of various geometry parameters. Experiments were performed at a low speed by the scheme of free cutting. Intensity of plastic shear strain was set for defining of cutting edge geometry effect on machining. Images of chip formed are shown. Estimation of strain magnitude was accomplished with digital image correlation method. Effect of rake angle and cutting edge angle has been studied. Depth of deformed layer and the area of the plastic strain is determine. Results showed that increasing the angle of the cutting edge inclination results in a change the mechanism of chip formation

    Life cycles and somatic production of hyperiids in the Okhotsk and Bering Seas

    Get PDF
    Hyperiid species Themisto pacifica , T. libellula , and Primno macropa are widespread in the Far-Eastern Seas. They are an important element of trophic web in pelagic communities of these seas. Their food spectra are very broad and include copepods, euphausiids, arrowworms, and fish larvae. On the other hand, the hyperiids play an important role in the diet of large-sized marine organisms as walleye pollock Theragra chalcogramma , mackerels Scomber japonicus , Pleurogrammus monopterygius , and Pleurogrammus azonus , and japanese squid Todarodes pacificus . Life cycles and production of these hyperiid species are described on the base of samples collected in complex surveys conducted by Pacific Fish. Res. Center (TINRO) in the Okhotsk Sea and the western Bering Sea in 1984-2011. All three species have similar life history though the maximal life span is 2 years for T. pacifica and T. libellula but 3 years for Primno macropa . They spawn twice in their life in the period from May to October with the peak in July. Their weight increments also increase twice, usually when their size is 7-10 and 10-12 mm for T. pacifica and P. macropa and 10-15 and 20-30 mm for T. libellula . The average specific daily production of hyperiids in the Okhotsk Sea is estimated as 0.0410 for T. pacifica , 0.0273 for T. libellula , and 0.0101 for P. macropa ; but in the western Bering Sea - as 0.0492 for T. pacifica , 0.0361 for T. libellula , and 0.0094 for P. macropa . The most favorable feeding grounds for hyperiids are located at Kuril Islands, at West Kamchatka, and in the Anadyr Bay. Their summary annual production is estimated as 30.235 mln t in the Okhotsk Sea and 21.370 mln t in the western Bering Sea

    Accelerated apoptotic death and <i>in vivo</i> turnover of erythrocytes in mice lacking functional mitogen- and stress-activated kinase MSK1/2

    Get PDF
    The mitogen- and stress-activated kinase MSK1/2 plays a decisive role in apoptosis. In analogy to apoptosis of nucleated cells, suicidal erythrocyte death called eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine (PS) externalization. Here, we explored whether MSK1/2 participates in the regulation of eryptosis. To this end, erythrocytes were isolated from mice lacking functional MSK1/2 (msk−/−) and corresponding wild-type mice (msk+/+). Blood count, hematocrit, hemoglobin concentration and mean erythrocyte volume were similar in both msk−/− and msk+/+ mice, but reticulocyte count was significantly increased in msk−/− mice. Cell membrane PS exposure was similar in untreated msk−/− and msk+/+ erythrocytes, but was enhanced by pathophysiological cell stressors ex vivo such as hyperosmotic shock or energy depletion to significantly higher levels in msk−/− erythrocytes than in msk+/+ erythrocytes. Cell shrinkage following hyperosmotic shock and energy depletion, as well as hemolysis following decrease of extracellular osmolarity was more pronounced in msk−/− erythrocytes. The in vivo clearance of autologously-infused CFSE-labeled erythrocytes from circulating blood was faster in msk−/− mice. The spleens from msk−/− mice contained a significantly greater number of PS-exposing erythrocytes than spleens from msk+/+ mice. The present observations point to accelerated eryptosis and subsequent clearance of erythrocytes leading to enhanced erythrocyte turnover in MSK1/2-deficient mice

    Changes in Prescribing Antithrombotic Therapy in Patients with Atrial Fibrillation in the Multidisciplinary Hospital in Volgograd from 2012 to 2020

    Get PDF
    Aim. To study the frequency of prescribing antithrombotic agents in patients with non-valvular atrial fibrillation (AF) in real clinical practice, to evaluate changes of prescriptions from 2012 till 2020.Material and methods. The medical records of inpatients (Form 003/y) with the diagnosis AF, hospitalized in the cardiological department were analyzed. According to the inclusion criteria, the patients were over 18 years of age, established diagnosis of non-valvular AF. There were two exclusion criteria: congenital and acquired valvular heart disease and prosthetic heart valves. In retrospective analysis we have included 263 case histories in 2012, 502 ones in 2016 and 524 in 2020. CHA2DS2-VASc score was used for individual stroke risk assessment in AF. The rational use of the antithrombotic therapy was evaluated according with current clinical practice guidelines at analyzing moment.Results. During period of observation the frequency of antiplatelet therapy significantly decreased from 25,5% to 5,5% (р&lt;0.001), decreased the frequency of administration of warfarin from 71,9% to 18,3% (р&lt;0.001). The frequency of use of direct oral anticoagulants increased in 2020 compared to 2016 (р&lt;0.001). For patients with a high risk of stroke anticoagulant therapy was administered in 71.8% of cases in 2012, 88.5% in 2016 and 92.5% in 2020. Before discharge from hospital majority of patients (72%) achieved a desired minimum international normalized ratio (INR) from 2.0 to 3.0 in 2012. In 2016 and 2020 an only 33% and 40.6% of patients achieved INR (2.0-3.0).Conclusion. Doctors have become more committed to following clinical guidelines during the period of the investigation. In 2020 antithrombotic therapy for atrial fibrillation was suitable according to current clinical guidelines
    corecore