196 results match your criteria: "Saint Petersburg University[Affiliation]"

The conductivity of the polymeric energy storage materials is the key factor limiting their performance. Conductivity of polymeric NiSalen materials, a prospective class of energy storage materials, was found to depend strongly on the length of the bridge between the nitrogen atoms of the ligand. Polymers obtained from the complexes containing C alkyl and hydroxyalkyl bridges showed an electrical conductivity one order of magnitude lower than those derived from more common complexes with C alkyl bridges.

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At least 50% of factors predisposing to alcohol dependence (AD) are genetic and women affected with this disorder present with more psychiatric comorbidities, probably indicating different genetic factors involved. We aimed to run a genome-wide association study (GWAS) followed by a bioinformatic functional annotation of associated genomic regions in patients with AD and eight related clinical measures. A genome-wide significant association of rs220677 with AD (-value = 1.

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To clarify the crystal chemical features of natural and synthetic oxalates Me2+(C2O4)∙2H2O (Me2+ = Fe, Mn, Mg, Zn), including minerals of the humboldtine group, solid solutions of lindbergite Mn(C2O4)∙2H2O−glushinskite Mg(C2O4)∙2H2O were precipitated under various conditions, close to those characteristic of mineralization in biofilms: at the stoichiometric ratios ((Mn + Mg)/C2O4 = 1) and non-stochiometric ratios ((Mn + Mg)/C2O4 < 1), in the presence and absence of citrate ions. Investigation of precipitates was carried out by powder X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Thermodynamic modelling was performed in order to evaluate the lindbergite−glushinskite equilibrium.

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In the field of complex dynamics, multistable attractors have been gaining significant attention due to their unpredictability in occurrence and extreme sensitivity to initial conditions. Co-existing attractors are abundant in diverse systems ranging from climate to finance and ecological to social systems. In this article, we investigate a data-driven approach to infer different dynamics of a multistable system using an echo state network.

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Stir membrane liquid-phase microextraction based on milk fats hydrolysis and deep eutectic solvent formation: Determination of bisphenols.

Food Chem

March 2023

Department of Analytical Chemistry, Institute of Chemistry, Saint-Petersburg University, Saint Petersburg State University, SPbSU, SPbU, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia.

In this paper, a stir membrane liquid-phase microextraction approach based on milk fats hydrolysis and in situ deep eutectic solvent formation was developed for the first time. The approach was applied to clean-up and preconcentrate bisphenols from milk samples. The procedure assumed alkaline hydrolysis of samples fats to obtain water-soluble salts of fatty acids that acted as precursors for the deep eutectic solvent formation.

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Alkyl polyglucoside-based supramolecular solvent formation in liquid-phase microextraction.

Anal Chim Acta

October 2022

Institute of Chemistry, Saint-Petersburg University St.Petersburg State University, SPbSU, SPbU, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia.

The phenomenon of alkyl polyglucoside-based supramolecular solvent formation in the presence of alkyl carboxylic acid acted as coacervation agent was described for the first time. Various alkyl polyglucosides and carboxylic acids were studied as the amphiphiles and coacervation agents, respectively. A possible mechanism of the new supramolecular solvent formation was presented.

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Liquid-liquid microextraction with hydrophobic deep eutectic solvent followed by magnetic phase separation for preconcentration of antibiotics.

Talanta

January 2023

Department of Analytical Chemistry, Institute of Chemistry, Saint-Petersburg University, Saint-Petersburg State University, 7/9 Universitetskaya Nab., Saint-Petersburg, 199034, Russia.

This study describes a miniaturized approach for liquid-liquid microextraction based on mass transfer into low volume of deep eutectic solvent and magnetic phase separation, using specially produced magnetic chromium dioxide nanoparticles with a hydrophobic surface layer of fatty acids. The nanoparticles modified with fatty acid helped to recover low volumes of viscous hydrophobic deep eutectic solvent-based extract reproducibly and easily (up to 10 μL) in a microextraction procedure with the application of magnetic forces. It was demonstrated that the collector properties depend on nanoparticles' surface and magnetic characteristics.

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The best way to study digenean diversity combines molecular genetic methods, life-cycle studies and elaborate morphological descriptions. This approach has been barely used for one of the most widespread digenean taxa parasitizing fish – the superfamily Hemiuroidea. Here, we applied the integrative approach to the hemiuroideans from the family Derogenidae parasitizing fish at the White and Barents Seas.

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Glioblastoma (GBM) is one of the most aggressive and lethal malignancy of the central nervous system. Temozolomide is the standard of care for gliomas, frequently results in resistance to drug and tumor recurrence. Therefore, further research is required for the development of effective drugs in order to guarantee specific treatments to succeed.

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An effervescence-assisted dispersive liquid-liquid microextraction based on three-component deep eutectic solvent for the determination of fluoroquinolones in foods.

Talanta

December 2022

Department of Analytical Chemistry, Institute of Chemistry, Saint-Petersburg University, St. Petersburg State University, SPbSU, SPbU, 7/9 Universitetskaya nab., St. Petersburg, 199034 Russia.

An effervescence-assisted dispersive liquid-liquid microextraction approach using three-component deep eutectic solvent based on short-chain and medium-chain carboxylic acids and terpenoid was developed for the first time. The microextraction procedure was applied to the determination of fluoroquinolone antibiotics in foods (milk and shrimp samples) by high-performance liquid chromatography with fluorometric detection. In this microextraction procedure three-component deep eutectic solvent acted as a proton donor agent and an extractant.

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Anionic catechol-containing polymers represent a promising class of functional dopants for the capacity improvement of conductive polymers. For example, sulfonated poly(vinylcatechol) SPVC with outstanding theoretical capacity was used as a dopant for poly(ethylenedixythiophene) (PEDOT) conductive polymer, increasing its energy storage performance. However, such materials suffer from insufficient utilization of the theoretical capacity of SPVC originating from non-optimal morphology.

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A challenging problem to create an efficient photocatalyst suitable for industrial water remediation, aiming to remove cyclic organic compounds attracts increasing attention. The current study aimed to clarify a few "dark spots" in the field, namely to find out if it is possible to make an efficient photocatalyst activated with visible light by using a simple and cheap strategy and what are the key factor impacting its efficiency. In this work, a new procedure to obtain spherical nanoparticles with the same average size but different amounts of oxygen vacancies and defects and dopant concentrations was developed.

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Attention deficit hyperactivity disorder (ADHD) is manifested by a specific set of behavioral deficits such as hyperactivity, impulsivity, and inattention. The dopamine neurotransmitter system is postulated to be involved in the pathogenesis of ADHD. Guanfacine, a selective α2A-adrenoceptor agonist, is prescribed for ADHD treatment.

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Trace amine-associated receptor 5 (TAAR5) is a G protein-coupled receptor that belongs to the TAARs family (TAAR1-TAAR9). TAAR5 is expressed in the olfactory epithelium and is responsible for sensing 3-methylamine (TMA). However, recent studies showed that TAAR5 is also expressed in the limbic brain regions and is involved in the regulation of emotional behaviour and adult neurogenesis, suggesting that TAAR5 antagonism may represent a novel therapeutic strategy for anxiety and depression.

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Article Synopsis
  • Modern IoT systems require advanced security measures, and static analysis has proven effective in analyzing their software, but increasing complexity necessitates the automation of this process.
  • A hypothesis is proposed suggesting that machine learning can enhance static analysis for IoT systems, leading to a structured research approach that confirms this applicability and establishes a framework.
  • Key contributions include systemizing static analysis stages, formalizing machine-learning models, reviewing related publications, proving machine learning's utility at various analysis stages, and presenting an intelligent framework for IoT static analysis.
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The autonomic aspects of the post-COVID19 syndrome.

Autoimmun Rev

May 2022

Ariel University, Israel; Zabludowicz Center for Autoimmune Diseases, Sheba Medical Center, Tel-Hashomer, Ramat-Gan 52621, Israel; Laboratory of the Mosaics of Autoimmunity, Saint Petersburg University, 199034, Russia.

The SARS-CoV-2 outbreak, responsible for the widespread COVID-19, led to one of the most rogue pandemics in modern time, yet the major effects of the pandemic may still be ahead of us. SARS-CoV-2 had been found to possess autoimmune properties. Close to 20 distinct autoantibodies which target GPCR of the nervous system and renin-angiotensin system-related molecules were found significantly associated with the clinical severity of COVID-19.

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Ensuring the security of modern cyberphysical devices is the most important task of the modern world. The reason for this is that such devices can cause not only informational, but also physical damage. One of the approaches to solving the problem is the static analysis of the machine code of the firmware of such devices.

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The possibility of using xenogeneic phagocytes in wound treatment.

PLoS One

February 2022

Laboratory of Insect Biopharmacology and Immunology, Saint-Petersburg University, Saint Petersburg, Russia.

Metamorphosis in the insect larva is associated with disintegration, engulf and digestion of larval tissues. These processes are accompanied by a significant shift in physiological parameters like high activity of hydrolytic enzymes and decrease of pH. In the way, the metamorphosing larva resembles the processes occurring in the wound at the stage of inflammation.

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Article Synopsis
  • Multimetallic plasmonic nanoparticles offer enhanced functionality for applications in catalysis and sensing compared to monometallic ones, due to their unique electronic structures.
  • Despite various techniques, creating these nanoparticles under controlled soft conditions remains challenging, but a new single-step laser-induced deposition method successfully synthesized mono-, bi-, and tri-metallic nanoparticles from existing precursors.
  • The study revealed that the size of the nanoparticles varies by metal type, with gold being the largest (140-200 nm), silver smaller (40-60 nm), and platinum the smallest (2-3 nm), while bi- and tri-metallic nanoparticles formed core-shell structures through alloying during growth.
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A method of mathematically processing the digital images of targets is developed. The theoretical and mathematical justification and the experimental validation of the possibility of estimating the amount of gunshot residue (GSR) and determining the GSR distribution over the target on the basis of its digital image is provided. The analysis of the optical density in selected concentric rings in the images reveals the radial dependence of soot distribution in the cross section of a gas-gunpowder jet.

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A surfactant-mediated microextraction of synthetic dyes from solid-phase food samples into the primary amine-based supramolecular solvent.

Food Chem

June 2022

Institute of Chemistry, Saint-Petersburg University, St.Petersburg State University, SPbSU, SPbU, 7/9 Universitetskaya nab., St., Petersburg 199034, Russia.

An effective and simple surfactant-mediated microextraction of synthetic dyes from solid-phase food samples into the primary amine-based supramolecular solvents is presented for the first time. The developed procedure involved two stages: (i) an isolation of dyes from a solid-phase food sample into a micellar solution of the primary amine; (ii) a preconcentration of the extracted dyes into the supramolecular solvent phase generated from the obtained micellar solution under a coacervation process. The microextraction procedure was applied for the determination of synthetic dyes in confectionery, dried fruits, and spices samples.

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The dopamine (DA) transporter (DAT) is part of a presynaptic multiprotein network involving interactions with scaffold proteins via its C-terminal PDZ domain-binding sequence. Using a mouse model expressing DAT with mutated PDZ-binding sequence (DAT-AAA), we previously demonstrated the importance of this binding sequence for striatal expression of DAT. Here, we show by application of direct stochastic reconstruction microscopy not only that the striatal level of transporter is reduced in DAT-AAA mice but also that the nanoscale distribution of this transporter is altered with a higher propensity of DAT-AAA to localize to irregular nanodomains in dopaminergic terminals.

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Reversed-phase dispersive liquid-liquid microextraction based on decomposition of deep eutectic solvent for the determination of lead and cadmium in vegetable oil.

Food Chem

March 2022

Department of Analytical Chemistry, Institute of Chemistry, Saint-Petersburg University, Saint Petersburg State University, SPbSU, SPbU, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia.

In this work, a reversed-phase dispersive liquid-liquid microextraction procedure based on the decomposition of deep eutectic solvent was suggested for the first time. The procedure was utilized for fast and simple separation of lead and cadmium from vegetable oil samples. The procedure assumed mixing of oil sample and DES based on menthol, formic acid and water.

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Investigation of the ciliate communities from the digestive tract of different wild vertebrates is important in context of host-specificity of different ciliate species and the detection of any cases of non-specific infection. Here we present a description and analysis of the fauna of ciliates (Litostomatea, Trichostomatia) inhabiting the intestine of the wild plains zebra (Equus quagga Boddaert, 1785) in South Africa. Nineteen species belonging to 12 genera of five families were found.

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