188 results match your criteria: "Universitetskaya emb. 7-9[Affiliation]"

A series of novel polysaccharide-based biocomposites was obtained by impregnation of bacterial cellulose produced by (BC) with the solutions of negatively charged polysaccharides-hyaluronan (HA), sodium alginate (ALG), or κ-carrageenan (CAR)-and subsequently with positively charged chitosan (CS). The penetration of the polysaccharide solutions into the BC network and their interaction to form a polyelectrolyte complex changed the architecture of the BC network. The structure, morphology, and properties of the biocomposites depended on the type of impregnated anionic polysaccharides, and those polysaccharides in turn determined the nature of the interaction with CS.

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Purpose: Prolonged air leak (PAL) is a challenging complication in thoracic surgery. The aim of this study was to analyze the incidence, risk factors, and outcomes of PAL.

Methods: We retrospectively analyzed 319 patients treated in a single center submitted to lobectomy, bilobectomy, segmentectomy, and wedge resections from January 2012 until August 2015.

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Polyphyletic origin, intracellular invasion, and meiotic genes in the putatively asexual agamococcidians (Apicomplexa incertae sedis).

Sci Rep

September 2020

Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya emb. 7/9, 199034, Saint Petersburg, Russian Federation.

Agamococcidians are enigmatic and poorly studied parasites of marine invertebrates with unexplored diversity and unclear relationships to other sporozoans such as the human pathogens Plasmodium and Toxoplasma. It is believed that agamococcidians are not capable of sexual reproduction, which is essential for life cycle completion in all well studied parasitic apicomplexans. Here, we describe three new species of agamococcidians belonging to the genus Rhytidocystis.

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Porphyrin-fullerene dyads were intensively studied as molecular donor-acceptor systems providing efficient photoinduced charge separation (CS). A practical advantage of the dyads is the possibility to tune its CS process by the porphyrin periphery modification, which allows one to optimize the dyad for particular applications. However, this tuning process is typically composed of a series of trial stages involving the development of complex synthetic schemes.

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Accurate species delimitation has a pivotal role in conservation biology, and it is especially important for threatened species where decisions have political and economic consequences. Finding and applying appropriate character sets and analytical tools to resolve interspecific relationships remains challenging in lichenized fungi. The main aim of our study was to re-assess the species boundaries between Usnea subfloridana and Usnea florida, which have been phylogenetically indistinguishable until now, but are different in reproductive mode and ecological preferences, using fungal-specific simple sequence repeats (SSR), i.

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A series of 3(2)-phosphonylated thiazolo[3,2-]oxopyrimidines was synthesized for the first time by the reactions of chloroethynylphosphonates with unsubstituted and 5(6)-substituted 2-thiouracils. The reaction of chloroethynylphosphonates with 6-substituted 2-thiouracils bearing electron-donor groups (CH, Ph) proceeded with high regioselectivity involving the cyclization through the N-nitrogen atom to form new 3-phosphonylated thiazolo[3,2-]-5-oxopyrimidines with good yield. In the case of unsubstituted and 5-methyl-2-thiouracils, cyclization occurred predominantly through the N atom and partially via the N-nitrogen atom to form a mixture of the corresponding thiazolo[3,2-]-7- and 5-oxopyrimidines.

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Single crystals of LuBaBO were obtained by cooling from a melt and polycrystals of the borate were prepared using a multi-step solid-state synthesis. The crystal structure was determined from single-crystal X-ray diffraction data. The borate crystallizes in a new structure type in the monoclinic crystal system in space group C2/c, with cell parameters a = 13.

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Multiple organ failure in COVID-19 patients is a serious problem which can result in a fatal outcome. Damage to organs and tissues, including general lung dysfunction, develops as a consequence of ischemia, which, in turn, is caused by thrombosis in small blood vessels and hypoxia, leading to oxidative stress and inflammation. Currently, research is underway to screen existing drugs for antioxidant, antiplatelet and anti-inflammatory properties.

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Article Synopsis
  • A collection of rhizobial strains was isolated from root nodules of specific legume species in Kamchatka Peninsula, revealing significant genetic diversity among the strains.
  • Only the strains from one genus were able to form nitrogen-fixing nodules on plants, with two notable strains exhibiting specific secretion system genes that may affect their ability to interact with different host plants.
  • The study suggests that variations in nodule types observed could be due to different nodulation strategies, highlighting the potential for these rhizobial strains to improve plant-microbe interactions and broaden host range through further research.*
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Weakly or "partially" bonded molecules are an important link between the chemical and van der Waals interactions. Molecular structures of six new SbBr -Py complexes in the solid state have been determined by single-crystal X-ray diffraction analysis. In all complexes all Sb atoms adopt a pseudo-octahedral coordination geometry which is completed by additional Sb⋅⋅⋅Br contacts shorter than the sum of the van der Waals radii, with Br-Sb⋅⋅⋅Br angles close to 180°.

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Stereotaxic intracerebral cannula implantation for neuroactive agent administration is a wide-spread method for chronic experiments requiring bypassing the blood-brain barrier in rodents. However, commercially available cannula are bulky and may interfere with animal movement or lead to their dislodging during grooming. As the number of cannula needed in one experiment, and the accompanying costs can be high, it is in the interest of researchers to produce them on their own.

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The activity of the hypothalamus-pituitary-adrenal (HPA) axis is pivotal in homeostasis and presides the adaptative response to stress. Dopamine Transporter (DAT) plays a key role in the regulation of the HPA axis. We used young adult female DAT Knockout (KO) rats to assess the effects of DAT ablation (partial, heterozygous DAT+/-, or total, homozygous DAT-/-) on vulnerability to stress.

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Wilson's disease (WD) is a rare autosomal recessive metabolic disorder resulting from mutations in the copper-transporting, P-type ATPase gene ATP7B gene, but influences of epigenetics, environment, age, and sex-related factors on the WD phenotype complicate diagnosis and clinical manifestations. Oxylipins, derivatives of omega-3, and omega-6 polyunsaturated fatty acids (PUFAs) are signaling mediators that are deeply involved in innate immunity responses; the regulation of inflammatory responses, including acute and chronic inflammation; and other disturbances related to any system diseases. Therefore, oxylipin profile tests are attractive for the diagnosis of WD.

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We present a comparative study of GaAs nanowire growth on Si(111) substrates by molecular beam epitaxy with the assistance of Au and Ag colloidal nanoparticles. Our approach allows the synthesis of nanowires with different catalyst materials in separate sectors of the same substrate within the same epitaxial process. We match the experimental results to the modeling of chemical potentials and nanowire length distributions to analyze the impact of silicon incorporation into the catalyst droplets on the growth rates and size homogeneity in ensembles of Au- and Ag-catalyzed GaAs nanowires.

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Intraspecific variability of cell reaggregation during reproduction cycle in sponges.

Zoology (Jena)

June 2020

Dept. Invertebrate Zoology, Biological Faculty, Lomonosov Moscow State University, 129281, Leninskie gory 1-12, Moscow, Russia.

The ability of sponge cells to reaggregate and reconstruct intact functional organism is known for more than 100 years. This process was studied in numerous species of sponges, and its interspecific variability is well described. However, some data also indicate the existence of a certain intraspecific variability of the cell reaggregation.

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The first case of microsporidiosis in .

Parasitology

August 2020

Department of Cytology and Histology, Saint Petersburg State University, Universitetskaya emb. 7/9, 199034Saint Petersburg, Russian Federation.

A new microsporidian species, Globosporidium paramecii gen. nov., sp.

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Growth of etiolated Arabidopsis hypocotyls is biphasic. During the first phase, cells elongate slowly and synchronously. At 48 h after imbibition, cells at the hypocotyl base accelerate their growth.

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Xenon in oxide frameworks: at the crossroads between inorganic chemistry and planetary science.

Dalton Trans

May 2020

Department of Crystallography, Institute of Earth Sciences, Saint Petersburg State University, Universitetskaya Emb. 7/9, 199034 St. Petersburg, Russia.

The chemistry of noble gases was for a long time dominated by fluoride-bearing compounds of xenon. However, the last two decades have brought new insights into the chemistry of xenon oxides and oxysalts, including insights involving a novel type of non-covalent interaction (aerogen bonding), discoveries of new xenon oxides, oxide perovskite frameworks and evidence for an abrupt increase of xenon reactivity under extreme pressure-temperature conditions. The complex implementation of these findings could facilitate the development of explanations for long-standing interdisciplinary problems, such as the depletion of heavy noble gases in contemporary planetary atmospheres - the cosmochemical enigma known as the "missing xenon" paradox.

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Freshwater mussels (Bivalvia: Unionidae) from the rising sun (Far East Asia): phylogeny, systematics, and distribution.

Mol Phylogenet Evol

May 2020

CIIMAR/CIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, P 4450-208 Matosinhos, Portugal.

Freshwater mussels (Bivalvia: Unionidae) is a diverse family with around 700 species being widespread in the Northern Hemisphere and Africa. These animals fulfill key ecological functions and provide important services to humans. Unfortunately, populations have declined dramatically over the last century, rendering Unionidae one of the world's most imperiled taxonomic groups.

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Novel heterocyclic chitosan derivatives and their derived nanoparticles: Catalytic and antibacterial properties.

Int J Biol Macromol

April 2020

Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya St. 6, Moscow, 117198, Russian Federation; Zelinsky Institute of Organic Chemistry RAS, Leninsky Prosp. 47, Moscow 119991, Russian Federation.

The metal-assisted nitrone-nitrile cycloaddition reaction is apply to empower chitosan chemistry. The ultrasonic irradiation has proven to efficiently accelerate the cycloaddition affording new heterocyclic (1,2,4-oxadiazoline) chitosan derivatives and avoiding ultrasonic degradation of the chitosan macromolecules. By varying the nitrone nature, both water- and toluene-soluble chitosan derivatives were successfully synthesized.

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Strategies of Speech Interaction between Adults and Preschool Children with Typical and Atypical Development.

Behav Sci (Basel)

December 2019

Department of Higher Nervous Activity and Psychophysiology, Saint Petersburg State University, Universitetskaya emb. 7-9, 199034 Saint-Petersburg, Russia.

The goal of this research is to study the speech strategies of adults' interactions with 4-7-year-old children. The participants are "mother-child" dyads with typically developing (TD, = 40) children, children with autism spectrum disorders (ASDs, = 20), Down syndrome (DS, = 10), and "experimenter-orphan" pairs ( = 20). Spectrographic, linguistic, phonetic, and perceptual analyses ( = 465 listeners) of children's speech and mothers' speech (MS) are executed.

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Chromosomal data are important for taxonomists, cytogeneticists and evolutionary biologists; however, the value of these data decreases sharply if they are obtained for individuals with inaccurate species identification or unclear species identity. To avoid this problem, here we suggest linking each karyotyped sample with its DNA barcode, photograph and precise geographic data, providing an opportunity for unambiguous identification of described taxa and for delimitation of undescribed species. Using this approach, we present new data on chromosome number diversity in neotropical butterflies of the subfamily Biblidinae (genus Kirby, 1871) and the tribe Ithomiini (genera Hübner, 1816, Hübner, 1816, Boisduval, 1870, Hübner, 1821, Bates, 1862, Godman et Salvin, 1879 and Godman et Salvin, 1879).

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The pentose phosphate pathway (PPP) of glucose metabolism in the brain serves as a primary source of NADPH which in turn plays a crucial role in multiple cellular processes, including maintenance of redox homeostasis and antioxidant defense. In our model of protective mild hypobaric hypoxia in rats (3MHH), an inverse correlation between hypoxia-inducible factor-1 (HIF1) activity and mRNA levels of glucose-6-phosphate dehydrogenase (G6PD), the key enzyme of PPP, was observed. In the present study, it was demonstrated that severe hypobaric hypoxia (SH) induced short-term upregulation of HIF1 alpha-subunit (HIF1α) in the hippocampal CA1 subfield and decreased the activity of G6PD.

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The synthesis and characterization of the first parent phosphanylalane and phosphanylgallane stabilized only by a Lewis base (LB) are reported. The corresponding substituted compounds, such as IDipp⋅GaH PCy (1) (IDipp=1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene) were obtained by the reaction of LiPCy with IDipp⋅GaH Cl. However, the LB-stabilized parent compounds IDipp⋅GaH PH (3) and IDipp⋅AlH PH (4) were prepared via a salt metathesis of LiPH ⋅DME with IDipp⋅E'H Cl (E'=Ga, Al) or by H -elimination reactions of IDipp⋅E'H (E'=Ga, Al) and PH , respectively.

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In this work, we demonstrate that the thiol-yne click reaction could be efficiently mediated by ultrasonic irradiation and implement the ultrasound-assisted thiol-yne click reaction to chitosan chemistry as a polymer-analogous transformation. We optimize power and frequency of ultrasound to preserve selectivity of the click reaction and avoid ultrasonic degradation of the chitosan polymer chain. Thus, we obtain a new water-soluble betaine.

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