Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters










Publication year range
1.
Environ Sci Pollut Res Int ; 31(1): 406-421, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38015398

ABSTRACT

Developed areas of the coal industry are subjected to long-term anthropogenic impacts from the input and accumulation of overburdened coal material, containing potentially toxic heavy metals and metalloids (HMM). For the first time, comprehensive studies of soils and plants in the territory of the Donetsk coal basin were carried out using X-ray fluorescence, atomic absorption analysis, and electron microscopy. The observed changes in the soil redox conditions were characterized by a high sulfur content, and formations of new microphases of S-containing compounds: FeS2, PbFe6(SO4)4(OH)12, ZnSO4·nH2O, revealed the presence of technogenic salinization, increased Сorg content, and low pH contents. Exceedances of soil maximum permissible concentrations of Pb, Zn, Cu, and As in areas affected by coal dumps were apparent. As a consequence of long-term transformation of the environment with changes in properties and chemical pollution, a phytotoxic effect was revealed in Phragmites australis (Cav.) Trin. ex Steud, accompanied by changes in ultrastructural and organization features of roots and leaves such as increases in root diameters and thickness of leaf blades. The changes in the ultrastructure of cell organelles: a violation of the grana formation process, an increase in the number of plastoglobules, a decrease in the number of mitochondrial cristae, and a reduction in the electron density of the matrix in peroxisomes were also observed. The accumulation of large electron-dense inclusions and membrane fragments in cell vacuoles was observed. Such ultrastructural changes may indicate the existence of a P. australis ecotype due to its long-term adaptation to the disturbed environment.


Subject(s)
Metals, Heavy , Soil Pollutants , Soil/chemistry , Poaceae/metabolism , Plants/metabolism , Soil Pollutants/analysis , Coal , Metals, Heavy/analysis
2.
Consort Psychiatr ; 4(2): 79-90, 2023 Jul 10.
Article in English | MEDLINE | ID: mdl-38250648

ABSTRACT

BACKGROUND: A substantial increase in the prevalence of eating disorders has been noticed over the past decades. Priority in the treatment of eating disorders is justifiably given to psychosocial interventions. However, it is also well known that centrally acting drugs can significantly affect appetite and food consumption. AIM: To narratively review the available neurobiological data on the mechanisms of central regulation of eating behavior as a rationale to summarize pharmacological strategies for appetite modulation in eating disorders. METHODS: The authors have carried out a narrative review of scientific papers published from January 2013 to March 2023 in the PubMed and Web of Science electronic databases. Studies were considered eligible if they included data on the neurobiological mechanisms of appetite regulation or the results of clinical trials of centrally acting drugs in eating disorders. Relevant studies were included regardless of their design. Descriptive analysis was used to summarize the obtained data. RESULTS: The review included 51 studies. The available neurobiological and clinical data allowed us to identify the following pharmacological strategies for appetite modulation in eating disorders: serotonergic, catecholaminergic, amino acidergic and peptidergic. However, implementation of these data into clinical practice difficult due to an insufficient number of good-quality studies, which is particularly relevant for adolescents as there is a research gap in this population. CONCLUSION: The progress in neurobiological understanding of the mechanisms of central regulation of appetite opens opportunities for new pharmacotherapeutic approaches aimed at changing the patterns of eating behavior. Obviously, treatment of eating disorders is a much broader problem and cannot be reduced to the correction of eating patterns. Nevertheless, at certain stages of treatment, drug-induced modulation of appetite can play an important role among multi-targeted biological and psychosocial interventions. Translation of neurobiological data into clinical practice requires a large number of clinical studies to confirm the long-term efficacy and safety of pharmacotherapeutic approaches and to develop personalized algorithms for the treatment of various forms of eating disorders in different age groups.

3.
Polymers (Basel) ; 14(16)2022 Aug 15.
Article in English | MEDLINE | ID: mdl-36015573

ABSTRACT

In this study, three-dimensional (3D) polyvinyl alcohol (PVA)/aligned boron nitride (BN) aerogel framework nanocomposites with high performance were fabricated by a facile strategy. The boron nitride powder was initially hydrolyzed and dispersed with a chemically crosslinked plasticizer, diethyl glycol (DEG), in the PVA polymer system. The boron nitride and DEG/PVA suspensions were then mixed well with different stoichiometric ratios to attain BN/PVA nanocomposites. Scanning electron microscopy revealed that BN platelets were well dispersed and successfully aligned/oriented in one direction in the PVA matrix by using a vacuum-assisted filtration technique. The formed BN/PVA aerogel cake composite showed excellent in-plane and out-of-plane thermal conductivities of 0.76 W/mK and 0.61 W/mK with a ratio of BN/PVA of (2:1) in comparison with 0.15 W/mK for the pure PVA matrix. These high thermal conductivities of BN aerogel could be attributed to the unidirectional orientation of boron nitride nanoplatelets with the post-two days vacuum drying of the specimens at elevated temperatures. This aerogel composite is unique of its kind and displayed such high thermal conductivity of the BN/PVA framework without impregnation by any external polymer. Moreover, the composites also presented good wettability results with water and displayed high electrical resistivity of ~1014 Ω cm. These nanocomposites thus, with such exceptional characteristics, have a wide range of potential uses in packaging and electronics for thermal management applications.

4.
Nanomaterials (Basel) ; 11(1)2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33450986

ABSTRACT

A series of NiO/C nanocomposites with NiO concentrations ranging from 10 to 90 wt% was synthesized using a simple and efficient two-step method based on non-isothermal decomposition of Nickel(II) bis(acetylacetonate). X-ray diffraction (XRD) measurements of these NiO/C nanocomposites demonstrate the presence of ß-NiO. NiO/C nanocomposites are composed of spherical particles distributed over the carbon support surface. The average diameter of nickel oxide spheres increases with the NiO content and are estimated as 36, 50 and 205 nm for nanocomposites with 10, 50 and 80 wt% NiO concentrations, respectively. In turn, each NiO sphere contains several nickel oxide nanoparticles, whose average sizes are 7-8 nm. According to the tests performed using a three-electrode cell, specific capacitance (SC) of NiO/C nanocomposites increases from 200 to 400 F/g as the NiO content achieves a maximum of 60 wt% concentration, after which the SC decreases. The study of the NiO/C composite showing the highest SC in three- and two-electrode cells reveals that its SC remains almost unchanged while increasing the current density, and the sample demonstrates excellent cycling stability properties. Finally, NiO/C (60% NiO) composites are shown to be promising materials for charging quartz clocks with a power rating of 1.5 V (30 min).

5.
Environ Geochem Health ; 43(6): 2301-2315, 2021 Jun.
Article in English | MEDLINE | ID: mdl-32794112

ABSTRACT

Metal speciation, linked directly to bioaccessibility and lability, is a key to be considered when assessing associated human and environmental health risks originated from anthropogenic activities. To identify the Zn and Cu speciation in the highly contaminated, technogenically transformed soils (Technosol) from the impact zone near the industrial sludge reservoirs of chemical plant (Siverskyi Donets River floodplain, southern Russia), the validity of the BCR sequential extraction procedure using the X-ray absorption fine-structure and X-ray powder diffraction (XRD) analyses was examined after each of the three stages. After the removal of exchange and carbonate-bonded Zn and Cu compounds from Technosol (first stage of extraction), the resulting residual soil showed enrichment in a great diversity of metal compounds, primarily with Me-S and Me-O bonds. The number of compounds with a higher solubility decreased at the subsequent stages of extraction. In the residual soil left over after extracting the first and second fractions, the dominant Zn-S bond appeared as würtzite (hexagonal ZnS) that made up more than 50%, while the Cu-S bond was almost completely represented only by chalcocite (Cu2S). The XRD analysis revealed the authigenic minerals of metals with S: sphalerite (cubic ZnS), würtzite (hexagonal ZnS), covellite (CuS) and bornite (Cu5FeS4). The scanning electron microscopy data confirmed that würtzite was the dominant form of Me with sulfur-containing and carbonate-containing minerals. The Zn-S bond was the main component (57%), whereas the Cu-O bond was dominant in the residual fraction (the fraction after the third-stage extraction). The results revealed that the composition of the residual fractions might include some of the most stable and hard-to-recover metal compounds of technogenic origin. Thus, the application of the novel instrumental methods, coupled with the chemical fractionation, revealed the incomplete selectivity of the extractants in the extraction of Zn and Cu in long-term highly contaminated soils.


Subject(s)
Copper/isolation & purification , Soil Pollutants/chemistry , Soil Pollutants/isolation & purification , Zinc/isolation & purification , Chemical Fractionation/methods , Copper/analysis , Copper/chemistry , Ferrous Compounds/chemistry , Humans , Microscopy, Electron, Scanning , Powders , Russia , Sewage , Soil/chemistry , Soil Pollutants/analysis , Spectrometry, X-Ray Emission , Sulfides/chemistry , X-Ray Absorption Spectroscopy , X-Ray Diffraction , Zinc/analysis , Zinc/chemistry , Zinc Compounds
6.
Zookeys ; (679): 47-53, 2017.
Article in English | MEDLINE | ID: mdl-28769707

ABSTRACT

The paper presents description and illustrations of a new peculiar species from the genus Psallops, P. coloratussp. n. from Southeast Asia (Singapore). Photographs, line drawings of the general habitus and a short comparison with a species from Thailand are provided.

7.
Zookeys ; (603): 161-9, 2016.
Article in English | MEDLINE | ID: mdl-27551202

ABSTRACT

A new species from Ghana, Psallops niedzwiedzkii Herczek & Popov, sp. n. is described. The dorsal habitus, head and male genitalia are presented and some morphological features are discussed. A key, short descriptions and map of the distribution of the African species of the genus are also provided.

8.
Zootaxa ; 4137(2): 233-8, 2016 Jul 11.
Article in English | MEDLINE | ID: mdl-27470718

ABSTRACT

A new genus and species of leptosaldine bugs, Leptosaldinea cobbeni gen. et sp. nov. (Hemiptera: Heteroptera: Leptopodidae) is described and illustrated from Burmese Middle Cretaceous (Albian-Cenomanian) amber found in Kachin State, northern Myanmar. This is the third record of a leptosaldine bug from Burmese amber. A brief analysis of the characters and systematic relationships of Leptosaldinae is provided.


Subject(s)
Heteroptera/classification , Amber/chemistry , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Female , Fossils/anatomy & histology , Heteroptera/anatomy & histology , Heteroptera/growth & development , Myanmar , Organ Size
9.
Zootaxa ; 4039(4): 566-74, 2015 Nov 06.
Article in English | MEDLINE | ID: mdl-26624642

ABSTRACT

Two new fossil representatives of the assassin bug family Reduviidae are described as new from Baltic amber (Upper Eocene), belonging to the genus Emesopsis of the tribe Ploiariolini (Emesinae): Emesopsis putshkovi sp. nov. and E. similis sp. nov. These representatives of the Emesinae are the oldest fossil bugs of the genus Emesopsis known so far, and reported for the first time. This genus is also briefly diagnosed.


Subject(s)
Amber/chemistry , Reduviidae/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Fossils/anatomy & histology , Male , Organ Size , Reduviidae/anatomy & histology , Reduviidae/growth & development
10.
Zookeys ; (489): 25-32, 2015.
Article in English | MEDLINE | ID: mdl-25878530

ABSTRACT

Hallodapomimusantennatus sp. n. (Hemiptera: Heteroptera, Miridae, Phylinae, Hallodapini) is described from a macropterous female found in Eocene Baltic amber. The new species can be recognized readily from the other species of the genus, mainly due to its unusual second antennal segment. A key for the identification of all known fossil Hallodapini is presented.

11.
Zootaxa ; 3887(4): 401-21, 2014 Nov 26.
Article in English | MEDLINE | ID: mdl-25543940

ABSTRACT

Metoisops akingbohungbei, M. groehni, M. punctatodiffusus, M. intergerivus, M. grabenhorsti, M. variabilis, and M. consimilis are described as new species from the late Eocene Baltic, Ukrainian, (Rovno) and Saxonian (Bitterfeld) amber. The new diagnosis of the genus Metoisops and also all species of this genus presented, along with illustrations. An analysis of all studied specimens referring to of Metoisops from different Eocene European amber demonstrates the great variability of their features, and allows for differentiation of species. Ratios of the width and length of body, eye, vertex, antennal and rostral segments, pronotum, mesoscutum and scutellum, claval commissura, length of hind femur, tibia and tarsus, corium and cuneus length, as well as ratio of membrane cell's width and length of all 9 species of the genus Metoisops are presented. 


Subject(s)
Amber/chemistry , Heteroptera/classification , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Heteroptera/anatomy & histology , Heteroptera/growth & development , Male , Organ Size
12.
Zootaxa ; 3878(4): 366-78, 2014 Oct 28.
Article in English | MEDLINE | ID: mdl-25544451

ABSTRACT

The paper presents descriptions and illustrations of two new species from the genus Psallops: P. schmitzi from New Hebridae and P. webbi from Nigeria. Photographs and line drawings general habitus and male genitalia are provided. A short review of the subfamily Psallopinae and two other related subfamilies Isometopinae and Cylapinae is given.


Subject(s)
Heteroptera/classification , Animal Distribution , Animals , Heteroptera/anatomy & histology , Heteroptera/physiology , Male , Nigeria , Species Specificity , Vanuatu
13.
Zootaxa ; 3878(5): 444-50, 2014 Oct 29.
Article in English | MEDLINE | ID: mdl-25544455

ABSTRACT

A new genus and species of leptopodid bug, Grimaldinia pronotalis Popov & Heiss is described and illustrated from Burmese Middle Cretaceous (Albian-Cenomanian) amber originating from the northern Myanmar's Kachin State. This is the second finding of Leptosaldinae (Leptopodidae), after Poinar published on Palaeoleptus burmanicus from Burmese amber in 2009.


Subject(s)
Heteroptera/classification , Amber/chemistry , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Female , Heteroptera/anatomy & histology , Heteroptera/growth & development , Male , Organ Size
14.
Zookeys ; (422): 23-33, 2014.
Article in English | MEDLINE | ID: mdl-25061387

ABSTRACT

A new genus and species of Discocephalini, Acanthocephalonotum martinsnetoi gen. n. et sp. n. is described from Río Pichileufú, middle Eocene of Patagonia, Argentina at palaeolatitude ~ 46°S. The new species is the first fossil representative of the Discocephalinae. This taxon is extant in equatorial to subtropical America, and some species reach warm temperate latitudes (Buenos Aires province). The new genus is distinguished from the other genera of Discocephalini by the combination of these characters: interocular width greater than head length; head massive and quadrangular with the anterior margin almost straight; juga touching each other; labrum thick and curved; triangular ante-ocular process extending beyond the eye; broad spine-like antero-lateral process of the pronotum; pronotum explanate and bean shaped; scutellum triangular with a circular tongue reaching the anterior side of abdominal segment 7; and wings well developed with membrane just surpassing end of abdomen.

15.
J Chem Phys ; 128(22): 224908, 2008 Jun 14.
Article in English | MEDLINE | ID: mdl-18554054

ABSTRACT

Using the complex Langevin sampling strategy, field theoretic simulations are performed to study the equilibrium phase behavior and structure of symmetric polycation-polyanion mixtures without salt in good solvents. Static structure factors for the segment density and charge density are calculated and used to study the role of fluctuations in the electrostatic and chemical potential fields beyond the random phase approximation. We specifically focus on the role of charge density and molecular weight on the structure and complexation behavior of polycation-polyanion solutions. A demixing phase transition to form a "complex coacervate" is observed in strongly charged systems, and the corresponding spinodal and binodal boundaries of the phase diagram are investigated.

16.
Antiviral Res ; 79(2): 136-41, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18378326

ABSTRACT

p27SJ is a novel protein from a callus culture of St. John's wort that modulates transcription of the HIV-1 promoter in several mammalian cells [Darbinian-Sarkissian, N., Darbinyan, A., Otte, J., Radhakrishnan, S., Sawaya, B.E., Arzumanyan, A., Chipitsyna, G., Popov, Y., Rappaport, J., Amini, S., Khalili, K., 2006. p27(SJ), a novel protein from St. John's wort, that suppresses expression of HIV-1 genome. Gene Ther. 13, 288-295]. Here, we armed p27SJ with signals from Ig-kappa light chain that allow its efficient excretion from the cells, and from HIV-1 Tat that facilitates its uptake by other cells for its utilization by a protein transduction method. We demonstrate that treatment of cells containing the HIV-1 LTR with conditioned media from cells expressing the armed p27SJ ((exc)p27SJ(upt)) results in suppression of the viral activation by the C/EBPbeta transcription factor. Once imported into the cells, (exc)p27SJ(upt) impacts the nuclear localization of C/EBPbeta and by retaining the protein in the cytoplasm affects its DNA binding and hence transcriptional activity. The armed p27SJ also inhibits Tat-induced activation of the LTR and decreases the level of viral replication in promonocytic cells including U-937 and T-lymphocytic cells. Our observations introduce a new bi-directional protein transduction system with a broad spectrum of applications for manufacturing therapeutic peptides by a specific group of cells called donor, and delivery to the target cells named recipient. Furthermore, our results support the utility of soluble p27SJ in suppressing transcription and replication of HIV-1 by interfering with the function of cellular proteins such as C/EBPbeta and viral activators including Tat.


Subject(s)
Anti-HIV Agents/metabolism , Anti-HIV Agents/pharmacology , HIV-1/drug effects , Hypericum/chemistry , Plant Proteins/metabolism , Plant Proteins/pharmacology , Transcription, Genetic , Anti-HIV Agents/isolation & purification , Astrocytes/virology , CCAAT-Enhancer-Binding Protein-beta/antagonists & inhibitors , Cell Line , Cells, Cultured , HIV Core Protein p24/biosynthesis , Humans , Microglia/virology , Monocytes/virology , Plant Proteins/genetics , Plant Proteins/isolation & purification , T-Lymphocytes/virology , tat Gene Products, Human Immunodeficiency Virus/antagonists & inhibitors
17.
Phys Rev E Stat Nonlin Soft Matter Phys ; 76(2 Pt 1): 021901, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17930059

ABSTRACT

Effects of sequence disorder on looping and cyclization of the double-stranded DNA are studied theoretically. Both random intrinsic curvature and inhomogeneous bending rigidity are found to result in a remarkably wide distribution of cyclization probabilities. For short DNA segments, the range of the distribution reaches several orders of magnitude for even completely random sequences. The ensemble averaged values of the cyclization probability are also calculated, and the connection to the recent experiments is discussed.


Subject(s)
Biophysics/methods , DNA/chemistry , Evolution, Molecular , Models, Statistical , Models, Theoretical , Nucleic Acid Conformation , Probability , Reproducibility of Results
18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 72(4 Pt 2): 046303, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16383529

ABSTRACT

Solvent loss due to evaporation in a drying drop can drive capillary flows and solute migration. The flow is controlled by the evaporation profile and the geometry of the drop. We predict the flow and solute migration near a sharp corner of the perimeter under the conditions of uniform evaporation. This extends the study of Popov and Witten [Phys. Rev. E 68, 036306 (2003)], which considered a singular evaporation profile, characteristic of a dry surrounding surface. We find the rate of the deposit growth along contact lines in early and intermediate time regimes. Compared to the dry-surface evaporation profile of Popov and Witten [Phys. Rev. E 68, 036306 (2003)], uniform evaporation yields more singular deposition in the early time regime, and nearly uniform deposition profile is obtained for a wide range of opening angles in the intermediate time regime. Uniform evaporation also shows a more pronounced contrast between acute opening angles and obtuse opening angles.

19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 71(5 Pt 1): 051905, 2005 May.
Article in English | MEDLINE | ID: mdl-16089569

ABSTRACT

We study the elastic response of a wormlike polymer chain with reversible kinklike structural defects. This is a generic model for (a) the double-stranded DNA with sharp bends induced by binding of certain proteins, and (b) effects of trans-gauche rotations in the backbone of the single-stranded DNA. The problem is solved both analytically and numerically by generalizing the well-known analogy to the quantum rotator. In the small stretching force regime, we find that the persistence length is renormalized due to the presence of the kinks. In the opposite regime, the response to the strong stretching is determined solely by the bare persistence length with exponential corrections due to the "ideal gas of kinks." This high-force behavior changes significantly in the limit of high bending rigidity of the chain. In that case, the leading corrections to the mechanical response are likely to be due to the formation of multikink structures, such as kink pairs.


Subject(s)
DNA Damage , DNA/chemistry , Models, Chemical , Models, Molecular , Computer Simulation , DNA/analysis , Elasticity , Nucleic Acid Conformation , Stress, Mechanical
20.
Phys Rev E Stat Nonlin Soft Matter Phys ; 71(3 Pt 2B): 036313, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15903580

ABSTRACT

A model accounting for the finite spatial dimensions of the deposit patterns in evaporating sessile drops of a colloidal solution on a plane substrate is proposed. The model is based on the assumption that the solute particles occupy finite volume and hence these dimensions are of steric origin. Within this model, the geometrical characteristics of the deposition patterns are found as functions of the initial concentration of the solute, the initial geometry of the drop, and the time elapsed from the beginning of the drying process. The model is solved analytically for small initial concentrations of the solute and numerically for arbitrary initial concentrations of the solute. The agreement between our theoretical results and the experimental data is demonstrated, and it is shown that the observed dependence of the deposit dimensions on the experimental parameters can indeed be attributed to the finite dimensions of the solute particles. These results are universal and do not depend on any free or fitting parameters; they are important for understanding evaporative deposition and may be useful for creating controlled deposition patterns.

SELECTION OF CITATIONS
SEARCH DETAIL
...