22 results match your criteria: "Oles Honchar Dnipropetrovsk National University[Affiliation]"

Neurodegenerative disorders pose a significant challenge to global healthcare systems due to their progressive nature and the resulting loss of neuronal cells and functions. Excitotoxicity, characterized by calcium overload, plays a critical role in the pathophysiology of these disorders. In this review article, we explore the involvement of calcium dysregulation in neurodegeneration and neurodegenerative disorders.

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Hylleraas' variational method with orthogonality restrictions.

J Mol Model

October 2019

Laboratoire de Physique et Chimie Théoriques, UMR 7019, CNRS & Université de Lorraine, 54506, Vandoeuvre-les-Nancy Cedex, France.

In this paper, we suggest a new computational technique for the minimization of Hylleraas' functional with additional orthogonality restrictions imposed on the desired vectors. It is shown how Hylleraas' constrained problem can be reduced to an unconstrained one by minimal computational efforts. The asymptotic projection (AP) method proposed earlier to minimize Rayleigh's quotient subject to some orthogonality restrictions is applied to construct a modified Hylleraas' functional whose solution fulfills the required constraints automatically.

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QSPR modeling of optical rotation of amino acids using specific quantum chemical descriptors.

J Mol Model

February 2018

Interdisciplinary Center for Nanotoxicity, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, PO Box 17910, Jackson, MS, 39217-0510, USA.

Many chemical phenomena occur in solution. Different solvents can change the optical activity of chiral molecules. The optical rotation angles of solutes of 75 amino acids in dimethylformamide, water and methanol were analyzed using the quantitative structure-activity relationships approach.

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Background: The current significant progress in the use of heart rate variability in the solution of many diagnostic and therapeutic problems is determined by the availability of standardized methods of measurement and physiological interpretation of heart rate variability indices on the one hand and the high technological level of state-of-the-art electronic measuring equipment that is used for automatic registration and computer processing of cardio-signals.

Methods: A retrospective analysis of anonymized cardio screening results of 22,433 adult residents of 565 settlements (cities and villages) across all 20 administrative districts of the Khmelnytskyi Region (Ukraine) was conducted to find a statistically significant connection between individual heart rate variability parameters and the age of people.

Results: Primary statistical analysis and visualization showed a correlation between the selected heart rate variability parameters and the age and sex of the examined persons.

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Nano-sized manganese ferrites Mn Fe О (х = 0-1.3) were prepared using contact non-equilibrium plasma (CNP) in two different pH (11.5 and 12.

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Crystal structure of 5-chloro--(5-phenyl-1-pyrazol-3-yl)benzene-1,2-di-amine.

Acta Crystallogr E Crystallogr Commun

June 2017

SSI "Institute for Single Crystals", National Academy of Sciences of Ukraine, 60 Nauky Ave., Kharkiv 61001, Ukraine.

The title compound, CHClN, crystallizes with two independent mol-ecules ( and ) in the asymmetric unit, which are far from planar as a result of steric repulsion between the rings. The benzene and phenyl rings are inclined to the central pyrazole ring by 46.64 (10) and 17.

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UV-vis spectroscopy and colorimetric models for detecting anthocyanin-metal complexes in plants: An overview of in vitro and in vivo techniques.

J Plant Physiol

May 2017

Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80 I-56124, Pisa, Italy. Electronic address:

Although anthocyanin (ACN) biosynthesis is one of the best studied pathways of secondary metabolism in plants, the possible physiological and ecological role(s) of these pigments continue to intrigue scientists. Like other dihydroxy B-ring substituted flavonoids, ACNs have an ability to bind metal and metalloid ions, a property that has been exploited for a variety of purposes. For example, the metal binding ability may be used to stabilize ACNs from plant food sources, or to modify their colors for using them as food colorants.

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Nitroaromatic compounds and the products of their degradation are toxic to bacteria, cells and animals. Various studies have been carried out to better understand the mechanism of toxicity of aromatic nitrocompounds and their relationship to humans and the environment. Recent data relate cytotoxicity of nitroaromatic compounds to their single- or two-electron enzymatic reduction.

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Background: Breast cancer is a leading cause of morbidity and mortality worldwide. Although mammography screening is available, there is an ongoing interest in improved early detection and prognosis. Herein, we have analysed a combination of serological biomarkers in a case-control cohort of sera taken before diagnosis.

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In silico kinetics of alkaline hydrolysis of 1,3,5-trinitro-1,3,5-triazinane (RDX): M06-2X investigation.

Environ Sci Process Impacts

March 2017

Interdisciplinary Center for Nanotoxicity, Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, USA.

Alkaline hydrolysis of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), as one of the most promising methods for nitrocompound remediation, was investigated computationally at the PCM(Pauling)/M06-2X/6-311++G(d,p) level of theory. Computational simulation shows that RDX hydrolysis is a highly exothermic multistep process involving initial deprotonation and nitrite elimination, cycle cleavage, further transformation of cycle-opened intermediates to end products caused by a series of C-N bond ruptures, hydroxide attachments, and proton transfers. Computationally predicted products of RDX hydrolysis such as nitrite, nitrous oxide, formaldehyde, formate, and ammonia correspond to experimentally observed ones.

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The reaction of 2-aryl-[1,2,4]triazolo[1,5-c]quinazolines with nucleophilic reagents (hydrazine hydrate, sodium hydroxide, sodium methoxide, hydrochloric acid) under acidic conditions leads to formation of compounds that tend to tautomerize. The products of the transformation are distinguished by the position (ortho-, meta-, para-) of the OCH group in the aryl moiety. To assign their structures we used the combined approach: experiment and theoretical modeling.

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A novel headspace single-drop microextraction method (HS-SDME) for determination of sulfite in the form of sulfur dioxide was developed. An optical probe was used as the droplet holder in the HS-SDME procedure, and the analytical signal (absorbance) was monitored online during the extraction process. The method is based on the conversion of sulfite to volatile sulfur dioxide by acidification of the analyzed solution.

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Article Synopsis
  • HMX is a military energetic material that can enter the environment during various stages like production and disposal, raising concerns about its impact.
  • A computational study explored how alkaline hydrolysis (breaking down HMX in a basic solution) could remediate this compound, revealing it as a complex, heat-releasing process with multiple steps and specific chemical transformations.
  • Although the hydrolysis at pH 10 is slow, the study predicts that increasing the pH to 11, 12, or 13 could dramatically speed up the breakdown of HMX.
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Article Synopsis
  • The study investigates how the explosive compound CL-20 interacts with Leonardite Humic Acid (LHA) using advanced computational methods.
  • It was found that for CL-20 to form stable complexes with LHA, the organic matter must undergo deprotonation, and the formation of hydrogen bonds was studied using specific theoretical frameworks.
  • The research concludes that CL-20 remains unchanged during adsorption, suggesting that its presence in soil may slow down its breakdown and degradation.
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Article Synopsis
  • Reduction and oxidation (redox) reactions are effective for removing nitrocompounds like TNT and DNT from contaminated environments.
  • The study investigates how these compounds interact with common inorganic ions (Na+, Cl-, NO3-) using advanced theoretical methods and aims to understand their bond interactions.
  • Findings indicate that these interactions significantly reduce the redox activity of nitrocompounds, and sodium complexes of NTO could potentially be reduced by metallic iron.
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A novel vortex-assisted liquid-liquid microextraction (VA-LLME) for determination of iodide was developed. The method includes the oxidation of iodide with iodate in the presence of hydrochloric acid followed by VA-LLME of the ion-pair formed between ICl2(-) and Astra Phloxine reagent (AP) and subsequent absorbance measurement at 555nm. The appropriate experimental conditions were investigated and found to be: 5mL of sample, 0.

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Optimal Placement of Irradiation Sources in the Planning of Radiotherapy: Mathematical Models and Methods of Solving.

Comput Math Methods Med

August 2016

SE "Dnepropetrovsk Medical Academy of Health Ministry of Ukraine", Dnipropetrovsk 49044, Ukraine.

This paper proposes and analyses a mathematical model for the problem of distribution of a finite number of irradiation sources during radiotherapy in continuous environments to maximize the minimal cumulative effects. A new algorithm based on nondifferentiable optimization techniques has been developed to solve this problem.

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Structure and Redox Properties of 5-Amino-3-nitro-1H-1,2,4-triazole (ANTA) Adsorbed on a Silica Surface: A DFT M05 Computational Study.

J Phys Chem A

July 2015

†Interdisciplinary Center for Nanotoxicity, Department of Chemistry and Biochemistry, Jackson State University, 1400 J. R. Lynch Street, Jackson, Mississippi 39217, United States.

Article Synopsis
  • A cluster approximation was utilized to study how 5-amino-3-nitro-1H-1,2,4-triazole (ANTA) adsorbs onto the (001) surface of α-quartz, revealing a nearly parallel orientation of the compound.
  • The binding between ANTA and the silica surface was analyzed using the atoms in molecules (AIM) method, highlighting that electron transfer affects the complex's structure and enhances hydrogen bonding.
  • The study compared the redox properties of adsorbed ANTA with those in gas and hydrated forms, finding that the adsorbed form is less capable of redox transformations than the hydrated version.
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Alkaline hydrolysis of hexahydro-1,3,5-trinitro-1,3,5-triazine: M06-2X investigation.

Chemosphere

September 2015

Interdisciplinary Center for Nanotoxicity, Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA. Electronic address:

Article Synopsis
  • A computational study was conducted to investigate how alkaline hydrolysis affects RDX, a potential environmental contaminant, using advanced theoretical chemistry methods.* -
  • The process begins with the removal of a proton from RDX by hydroxide, resulting in the elimination of nitrite and the formation of a cyclohexene intermediate, followed by a significant ring-opening reaction facilitated by hydroxide.* -
  • The primary decomposition pathway produces 4-nitro-2,4-diazabutanal, leading to byproducts like formaldehyde and nitrous oxide, and the findings align well with existing experimental data on RDX hydrolysis.*
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Are the reduction and oxidation properties of nitrocompounds dissolved in water different from those produced when adsorbed on a silica surface? A DFT M05-2X computational study.

J Comput Chem

May 2015

Department of Chemistry and Biochemistry, Interdisciplinary Nanotoxicity Center, Jackson State University, Jackson, Mississippi, 39217; Department of Organic Chemistry, Oles Honchar Dnipropetrovsk National University, Dnipropetrovsk, 49010, Ukraine.

Article Synopsis
  • The study compared the reduction and oxidation properties of four nitrocompounds in water and when adsorbed on a silica surface, which simulates soil conditions.
  • Researchers used cluster models and solvation models to analyze important properties like electron affinity and Gibbs free energy.
  • Results showed that nitrocompounds in water are more easily transformed than those on silica, with TNT being the most reactive for gaining electrons, while NTO showed deprotonation when adsorbed.
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We carried out a quantitative assessment of the consumption of herbaceous plants by Opatrumsabulosum (Linnaeus, 1761) - a highly significant agricultural pest species. We researched the feeding preferences of this pest species with respect to 33 uncultivated and 22 cultivated plant species. This species of darkling beetle feeds on many uncultivated plant species, including those with hairy leaves and bitter milky sap, such as Scabiosaucrainca (5.

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Potentiometric propranolol-selective sensor based on molecularly imprinted polymer.

Anal Bioanal Chem

January 2013

Analytical Chemistry Department, Oles Honchar Dnipropetrovsk National University, av.Gagarina72, 49050 Dnipropetrovsk, Ukraine.

A novel potentiometric sensor based on molecularly imprinted polymer (MIP) for propranolol, an adrenergic-blocking drug, was designed. The influence of molecularly imprinted polymer particle content and sodium tetraphenylborate additives in polyvinylchloride membrane was shown. The electrodes show near-Nernstian responses down to 10(-4)-10(-5) M propranolol concentration.

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