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1.
Biochemistry (Mosc) ; 89(4): 626-636, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38831500

RESUMO

Su(Hw) belongs to the class of proteins that organize chromosome architecture, determine promoter activity, and participate in formation of the boundaries/insulators between the regulatory domains. This protein contains a cluster of 12 zinc fingers of the C2H2 type, some of which are responsible for binding to the consensus site. The Su(Hw) protein forms complex with the Mod(mdg4)-67.2 and the CP190 proteins, where the last one binds to all known Drosophila insulators. To further study functioning of the Su(Hw)-dependent complexes, we used the previously described su(Hw)E8 mutation with inactive seventh zinc finger, which produces mutant protein that cannot bind to the consensus site. The present work shows that the Su(Hw)E8 protein continues to directly interact with the CP190 and Mod(mdg4)-67.2 proteins. Through interaction with Mod(mdg4)-67.2, the Su(Hw)E8 protein can be recruited into the Su(Hw)-dependent complexes formed on chromatin and enhance their insulator activity. Our results demonstrate that the Su(Hw) dependent complexes without bound DNA can be recruited to the Su(Hw) binding sites through the specific protein-protein interactions that are stabilized by Mod(mdg4)-67.2.


Assuntos
Cromatina , Proteínas de Drosophila , Drosophila melanogaster , Proteínas Repressoras , Fatores de Transcrição , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/química , Animais , Cromatina/metabolismo , Fatores de Transcrição/metabolismo , Drosophila melanogaster/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Ligação Proteica , Proteínas Nucleares/metabolismo , Proteínas de Ligação a DNA/metabolismo , Dedos de Zinco , Proteínas Associadas aos Microtúbulos
2.
PLoS One ; 19(5): e0302890, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38743712

RESUMO

Susceptibility to emotional contagion is defined as the disposition of how susceptible someone is to catch others' emotions and it has long been studied in research on mental health, well-being, and social interaction. Given that existing self-report measures of susceptibility to emotional contagion have focused almost exclusively on negative emotions, we developed a self-report measure to assess the susceptibility to emotional contagion of both positive and negative emotions (2 scales). In two studies, we examined their factor structure, validity, and reliability using exploratory factor analysis (Study 1, N = 257), confirmatory factor analysis (Study 2, N = 247) and correlations. Our results confirmed the two-factor structure and demonstrated good internal consistencies. Regarding external validity, our scales showed diverging correlational patterns: While susceptibility to negative emotional contagion was linked to mental health problems and negative emotions, susceptibility to positive emotional contagion was linked to interpersonal functioning and prosocial tendencies. In conclusion, our scales appear to be internally/externally valid and a promising tool for future research.


Assuntos
Emoções , Autorrelato , Humanos , Masculino , Emoções/fisiologia , Feminino , Adulto , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Análise Fatorial , Relações Interpessoais , Saúde Mental
3.
Waste Manag ; 182: 207-214, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38670004

RESUMO

The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process.


Assuntos
Materiais de Construção , Materiais de Construção/análise , Reciclagem/métodos , Vento , Compostos de Cálcio/química , Gerenciamento de Resíduos/métodos , Resíduos Sólidos/análise , Vidro , Óxidos
4.
ACS Photonics ; 11(3): 1147-1155, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38523745

RESUMO

Acoustic nanocavities (ANCs) with resonance frequencies much above 1 GHz are prospective to be exploited in sensors and quantum operating devices. Nowadays, acoustic nanocavities fabricated from van der Waals (vdW) nanolayers allow them to exhibit resonance frequencies of the breathing acoustic mode up to f ∼ 1 THz and quality factors up to Q ∼ 103. For such high acoustic frequencies, electrical methods fail, and optical techniques are used for the generation and detection of coherent phonons. Here, we study experimentally acoustic nanocavities fabricated from WSe2 layers with thicknesses from 8 up to 130 nm deposited onto silica colloidal crystals. The substrate provides a strong mechanical support for the layers while keeping their acoustic properties the same as in membranes. We concentrate on experimental and theoretical studies of the amplitude of the optically measured acoustic signal from the breathing mode, which is the most important characteristic for acousto-optical devices. We probe the acoustic signal optically with a single wavelength in the vicinity of the exciton resonance and measure the relative changes in the reflectivity induced by coherent phonons up to 3 × 10-4 for f ∼ 100 GHz. We reveal the enhancement of photon-phonon interaction for a wide range of acoustic frequencies and show high sensitivity of the signal amplitude to the photoelastic constants governed by the deformation potential and dielectric function for photon energies near the exciton resonance. We also reveal a resonance in the photoelastic response (we call it photoelastic resonance) in the nanolayers with thickness close to the Bragg condition. The estimates show the capability of acoustic nanocavities with an exciton resonance for operations with high-frequency single phonons at an elevated temperature.

5.
ACS Nano ; 18(4): 3447-3455, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38252695

RESUMO

Ultrafast all-optical modulation with optically resonant nanostructures is an essential technology for high-speed signal processing on a compact optical chip. Key challenges that exist in this field are relatively low and slow modulations in the visible range as well as the use of expensive materials. Here we develop an ultrafast all-optical modulator based on MAPbBr3 perovskite metasurface supporting exciton-polariton states with exceptional points. The additional angular and spectral filtering of the modulated light transmitted through the designed metasurface allows us to achieve 2500% optical signal modulation with the shortest modulation time of 440 fs at the pump fluence of ∼40 µJ/cm2. Such a value of the modulation depth is record-high among the existing modulators in the visible range, while the main physical effect behind it is polariton condensation. Scalable and cheap metasurface fabrication via nanoimprint lithography along with the simplicity of perovskite synthesis and deposition make the developed approach promising for real-life applications.

6.
Nano Lett ; 23(17): 8186-8193, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37603607

RESUMO

The increasing role of two-dimensional (2D) devices requires the development of new techniques for ultrafast control of physical properties in 2D van der Waals (vdW) nanolayers. A special feature of heterobilayers assembled from vdW monolayers is femtosecond separation of photoexcited electrons and holes between the neighboring layers, resulting in the formation of Coulomb force. Using laser pulses, we generate a 0.8 THz coherent breathing mode in MoSe2/WSe2 heterobilayers, which modulates the thickness of the heterobilayer and should modulate the photogenerated electric field in the vdW gap. While the phonon frequency and decay time are independent of the stacking angle between the MoSe2 and WSe2 monolayers, the amplitude decreases at intermediate angles, which is explained by a decrease in the photogenerated electric field between the layers. The modulation of the vdW gap by coherent phonons enables a new technology for the generation of THz radiation in 2D nanodevices with vdW heterobilayers.

7.
Nano Lett ; 23(17): 7876-7882, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37638634

RESUMO

Guided 2D exciton-polaritons, resulting from the strong coupling of excitons in semiconductors with nonradiating waveguide modes, provide an attractive approach toward developing novel on-chip optical devices. These quasiparticles are characterized by long propagation distances and efficient nonlinear interactions but cannot be directly accessed from the free space. Here we demonstrate a powerful approach for probing and manipulating guided polaritons in a Ta2O5 slab integrated with a WS2 monolayer using evanescent coupling through a high-index solid immersion lens. Tuning the nanoscale lens-sample gap allows for extracting all of the intrinsic parameters of the system. We also demonstrate the transition from weak to strong coupling accompanied by the onset of the motional narrowing effect: with the increase of exciton-photon coupling strength, the inhomogeneous contribution to polariton line width, inherited from the exciton resonance, becomes fully lifted. Our results enable the development of integrated optics employing room-temperature exciton-polaritons in 2D semiconductor-based structures.

8.
Int J Mol Sci ; 24(10)2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37240451

RESUMO

Mutations in the GBA1 gene, encoding the lysosomal enzyme glucocerebrosidase (GCase), cause Gaucher disease (GD) and are the most common genetic risk factor for Parkinson's disease (PD). Pharmacological chaperones (PCs) are being developed as an alternative treatment approach for GD and PD. To date, NCGC00241607 (NCGC607) is one of the most promising PCs. Using molecular docking and molecular dynamics simulation we identified and characterized six allosteric binding sites on the GCase surface suitable for PCs. Two sites were energetically more preferable for NCGC607 and located nearby to the active site of the enzyme. We evaluated the effects of NCGC607 treatment on GCase activity and protein levels, glycolipids concentration in cultured macrophages from GD (n = 9) and GBA-PD (n = 5) patients as well as in induced human pluripotent stem cells (iPSC)-derived dopaminergic (DA) neurons from GBA-PD patient. The results showed that NCGC607 treatment increased GCase activity (by 1.3-fold) and protein levels (by 1.5-fold), decreased glycolipids concentration (by 4.0-fold) in cultured macrophages derived from GD patients and also enhanced GCase activity (by 1.5-fold) in cultured macrophages derived from GBA-PD patients with N370S mutation (p < 0.05). In iPSC-derived DA neurons from GBA-PD patients with N370S mutation NCGC607 treatment increased GCase activity and protein levels by 1.1-fold and 1.7-fold (p < 0.05). Thus, our results showed that NCGC607 could bind to allosteric sites on the GCase surface and confirmed its efficacy on cultured macrophages from GD and GBA-PD patients as well as on iPSC-derived DA neurons from GBA-PD patients.


Assuntos
Doença de Gaucher , Doença de Parkinson , Humanos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/genética , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Simulação de Acoplamento Molecular , Doença de Gaucher/tratamento farmacológico , Doença de Gaucher/genética , Técnicas de Cultura de Células , Sítios de Ligação , Glicolipídeos , Mutação
9.
Materials (Basel) ; 16(4)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36837021

RESUMO

In the present study we investigated the nanostructuring processes in locally suspended few-layer graphene (FLG) films by irradiation with high energy ions (Xe, 26-167 MeV). For such an energy range, the main channel of energy transfer to FLG is local, short-term excitation of the electronic subsystem. The irradiation doses used in this study are 1 × 1011-5 × 1012 ion/cm2. The structural transformations in the films were identified by Raman spectroscopy and transmission electron microscopy. Two types of nanostructures formed in the FLG films as a result of irradiation were revealed. At low irradiation doses the nanostructures were formed preferably at a certain distance from the ion track and had the form of 15-35 nm "bunches". We assumed that the internal mechanical stress that arises due to the excited atoms ejection from the central track part creates conditions for the nanodiamond formation near the track periphery. Depending on the energy of the irradiating ions, the local restructuring of films at the periphery of the ion tracks can lead either to the formation of nanodiamonds (ND) or to the formation of AA' (or ABC) stacking. The compressive strain value and pressure at the periphery of the ion track were estimated as ~0.15-0.22% and ~0.8-1.2 GPa, respectively. The main novel results are the first visualization of ion tracks in graphene in the form of diamond or diamond-like rings, the determination of the main condition for the diamond formation (the absence of a substrate in combination with high ion energy), and estimates of the local strain at the track periphery. Generally, we have developed a novel material and have found how to control the film properties by introducing regions similar to quantum dots with the diamond interface in FLG films.

10.
Nanomaterials (Basel) ; 12(24)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36558302

RESUMO

The use of low-temperature (LT) GaAs layers as dislocation filters in GaAs/Si heterostructures (HSs) was investigated in this study. The effects of intermediate LT-GaAs layers and of the post-growth and cyclic in situ annealing on the structural properties of GaAs/LT-GaAs/GaAs/Si(001) HSs were studied. It was found that the introduction of LT-GaAs layers, in combination with post-growth cyclic annealing, reduced the threading dislocation density down to 5 × 106 cm-2, the root-mean-square roughness of the GaAs surface down to 1.1 nm, and the concentration of non-radiative recombination centers in the near-surface GaAs/Si regions down to the homoepitaxial GaAs level. Possible reasons for the improvement in the quality of near-surface GaAs layers are discussed. On the one hand, the presence of elastic deformations in the GaAs/LT-GaAs system led to dislocation line bending. On the other hand, gallium vacancies, formed in the LT-GaAs layers, diffused into the overlying GaAs layers and led to an increase in the dislocation glide rate. It was demonstrated that the GaAs/Si HSs obtained with these techniques are suitable for growing high-quality light-emitting HSs with self-assembled quantum dots.

11.
Nano Lett ; 22(22): 9092-9099, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36342753

RESUMO

Exciton-polaritons offer a versatile platform for realization of all-optical integrated logic gates due to the strong effective optical nonlinearity resulting from the exciton-exciton interactions. In most of the current excitonic materials there exists a direct connection between the exciton robustness to thermal fluctuations and the strength of the exciton-exciton interaction, making materials with the highest levels of exciton nonlinearity applicable at cryogenic temperatures only. Here, we show that strong polaronic effects, characteristic for perovskite materials, allow overcoming this limitation. Namely, we demonstrate a record-high value of the nonlinear optical response in the nanostructured organic-inorganic halide perovskite MAPbI3, experimentally detected as a 19.7 meV blueshift of the polariton branch under femtosecond laser irradiation. This is substantially higher than characteristic values for the samples based on conventional semiconductors and monolayers of transition-metal dichalcogenides. The observed strong polaron-enhanced nonlinearity exists for both tetragonal and orthorhombic phases of MAPbI3 and remains stable at elevated temperatures.

12.
PLoS One ; 17(10): e0272738, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36201409

RESUMO

As of today, surprisingly little is known about the subjective well-being of faculty in general, but especially when teaching online and during a time of pandemic during lockdowns in particular. To narrow this research gap, the present study systematically compared the subjective well-being of faculty teaching face-to-face before to those teaching online during the COVID-19 pandemic, adopting a self-determination theory framework. The data reported here stem from a study conducted before the pandemic (Sample 1, n = 101) and which repeated-measures survey design we replicated to collect corresponding data during the pandemic (Sample 2, n = 71). Results showed that faculty teaching online during the pandemic reported impaired satisfaction of all three basic needs, that is reduced autonomy, competence, and especially relatedness, as well as impaired subjective well-being (clearly reduced enjoyment and reduced teaching satisfaction; increased anger and a tendency towards more shame) compared to faculty teaching face-to-face before the pandemic. Yet pride, anxiety, and boredom were experienced to a similar extent across both samples. The effects of the teaching format on the different aspects of subjective well-being were overall mediated in self-determination-theory-congruent ways by the satisfaction of the basic needs for autonomy, competence, and relatedness. We conclude for a post-pandemic future that online teaching will supplement rather than replace face-to-face teaching in higher education institutions, as their importance for building relationships and satisfying social interactions not only for students but also for faculty seem to have been underestimated so far.


Assuntos
COVID-19 , Satisfação Pessoal , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Docentes , Fadiga , Humanos , Pandemias
13.
Nanomaterials (Basel) ; 12(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36296897

RESUMO

In this study, the appearance of magnetic moments and ferromagnetism in nanostructures of non-magnetic materials based on silicon and transition metals (such as iron) was considered experimentally and theoretically. An analysis of the related literature shows that for a monolayer iron coating on a vicinal silicon surface with (111) orientation after solid-phase annealing at 450-550 °C, self-ordered two-dimensional islands of α-FeSi2 displaying superparamagnetic properties are formed. We studied the transition to ferromagnetic properties in a system of α-FeSi2 nanorods (NRs) in the temperature range of 2-300 K with an increase in the iron coverage to 5.22 monolayers. The structure of the NRs was verified along with distortions in their lattice parameters due to heteroepitaxial growth. The formation of single-domain grains in α-FeSi2 NRs with a cross-section of 6.6 × 30 nm2 was confirmed by low-temperature and field studies and FORC (first-order magnetization reversal curves) diagrams. A mechanism for maintaining ferromagnetic properties is proposed. Ab initio calculations in freestanding α-FeSi2 nanowires revealed the formation of magnetic moments for some surface Fe atoms only at specific facets. The difference in the averaged magnetic moments between theory and experiments can confirm the presence of possible contributions from defects on the surface of the NRs and in the bulk of the α-FeSi2 NR crystal lattice. The formed α-FeSi2 NRs with ferromagnetic properties up to 300 K are crucial for spintronic device development within planar silicon technology.

15.
Biology (Basel) ; 11(8)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35892961

RESUMO

It is challenging to estimate the post-mortem interval (PMI) of skeletal remains within a forensic context. As a result of their interactions with the environment, bones undergo several chemical and physical changes after death. So far, multiple methods have been used to follow up on post-mortem changes. There is, however, no definitive way to estimate the PMI of skeletal remains. This research aimed to propose a methodology capable of estimating the PMI using micro-computed tomography measurements of 104 human skeletal remains with PMIs between one day and 2000 years. The present study indicates that micro-computed tomography could be considered an objective and precise method of PMI evaluation in forensic medicine. The measured parameters show a significant difference regarding the PMI for Cort Porosity p < 0.001, BV/TV p > 0.001, Mean1 p > 0.001 and Mean2 p > 0.005. Using a machine learning approach, the neural network showed an accuracy of 99% for distinguishing between samples with a PMI of less than 100 years and archaeological samples.

16.
J Phys Chem Lett ; 13(20): 4612-4620, 2022 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-35588008

RESUMO

A micro- or nanosized electrically controlled source of optical radiation is one of the key elements in optoelectronic systems. The phenomenon of light emission via inelastic tunneling (LEIT) of electrons through potential barriers or junctions opens up new possibilities for development of such sources. In this work, we present a simple approach for fabrication of nanoscale electrically driven light sources based on LEIT. We employ STM lithography to locally modify the surface of a Si/Au film stack via heating, which is enabled by a high-density tunnel current. Using the proposed technique, hybrid Si/Au nanoantennas with a minimum diameter of 60 nm were formed. Studying both electronic and optical properties of the obtained nanoantennas, we confirm that the resulting structures can efficiently emit photons in the visible range because of inelastic scattering of electrons. The proposed approach allows for fabrication of nanosized hybrid nanoantennas and studying their properties using STM.

17.
Cancer Biomark ; 33(4): 479-488, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35491772

RESUMO

NASA's Jet Propulsion Laboratory (JPL) is advancing research capabilities for data science with two of the National Cancer Institute's major research programs, the Early Detection Research Network (EDRN) and the Molecular and Cellular Characterization of Screen-Detected Lesions (MCL), by enabling data-driven discovery for cancer biomarker research. The research team pioneered a national data science ecosystem for cancer biomarker research to capture, process, manage, share, and analyze data across multiple research centers. By collaborating on software and data-driven methods developed for space and earth science research, the biomarker research community is heavily leveraging similar capabilities to support the data and computational demands to analyze research data. This includes linking diverse data from clinical phenotypes to imaging to genomics. The data science infrastructure captures and links data from over 1600 annotations of cancer biomarkers to terabytes of analysis results on the cloud in a biomarker data commons known as "LabCAS". As the data increases in size, it is critical that automated approaches be developed to "plug" laboratories and instruments into a data science infrastructure to systematically capture and analyze data directly. This includes the application of artificial intelligence and machine learning to automate annotation and scale science analysis.


Assuntos
Inteligência Artificial , Ciência de Dados , Biomarcadores Tumorais , Ecossistema , Humanos , Software
18.
Int J Mol Sci ; 22(22)2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34830334

RESUMO

An association between high serum calcium/phosphate and cardiovascular events or death is well-established. However, a mechanistic explanation of this correlation is lacking. Here, we examined the role of calciprotein particles (CPPs), nanoscale bodies forming in the human blood upon its supersaturation with calcium and phosphate, in cardiovascular disease. The serum of patients with coronary artery disease or cerebrovascular disease displayed an increased propensity to form CPPs in combination with elevated ionised calcium as well as reduced albumin levels, altogether indicative of reduced Ca2+-binding capacity. Intravenous administration of CPPs to normolipidemic and normotensive Wistar rats provoked intimal hyperplasia and adventitial/perivascular inflammation in both balloon-injured and intact aortas in the absence of other cardiovascular risk factors. Upon the addition to primary human arterial endothelial cells, CPPs induced lysosome-dependent cell death, promoted the release of pro-inflammatory cytokines, stimulated leukocyte adhesion, and triggered endothelial-to-mesenchymal transition. We concluded that CPPs, which are formed in the blood as a result of altered mineral homeostasis, cause endothelial dysfunction and vascular inflammation, thereby contributing to the development of cardiovascular disease.


Assuntos
Angina Pectoris/fisiopatologia , Isquemia Encefálica/fisiopatologia , Cloreto de Cálcio/sangue , Doença da Artéria Coronariana/fisiopatologia , Células Endoteliais/patologia , Infarto do Miocárdio/fisiopatologia , Fosfatos/sangue , Angina Pectoris/sangue , Angina Pectoris/genética , Animais , Aorta/metabolismo , Aorta/patologia , Isquemia Encefálica/sangue , Isquemia Encefálica/genética , Cloreto de Cálcio/química , Estudos de Casos e Controles , Morte Celular , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/genética , Células Endoteliais/metabolismo , Transição Epitelial-Mesenquimal , Floculação , Regulação da Expressão Gênica , Humanos , Inflamação , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Leucócitos/metabolismo , Leucócitos/patologia , Lisossomos/metabolismo , Lisossomos/patologia , Masculino , Infarto do Miocárdio/sangue , Infarto do Miocárdio/genética , Fosfatos/química , Cultura Primária de Células , Ratos , Ratos Wistar , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Túnica Íntima/metabolismo , Túnica Íntima/patologia , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
19.
Front Vet Sci ; 8: 723375, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504890

RESUMO

African swine fever (ASF) is an incurable viral disease of domestic and wild pigs. A large-scale spread of ASF began in Eurasia in 2007 and has affected territories from Belgium to the Far East, occurring as both local- and regional-level epidemics. In 2020, a massive ASF epidemic emerged in the southeastern region of European Russia in the Samara Oblast and included 41 outbreaks of ASF in domestic pigs and 40 cases in wild boar. The Samara Oblast is characterized by a relatively low density of wild boar (0.04-0.05 head/km2) and domestic pigs (1.1-1.3 head/km2), with a high prevalence of small-scale productions (household farms). This study aims to understand the driving forces of the disease and perform a risk assessment for this region using complex epidemiological analyses. The socioeconomic and environmental factors of the ASF outbreak were explored using Generalized Linear Logistic Regression, where ASF infection status of the Samara Oblast districts was treated as a response variable. Presence of the virus in a district was found to be most significantly (p < 0.05) associated with the importation of live pigs from ASF-affected regions of Russia (OR = 371.52; 95% CI: 1.58-87290.57), less significantly (p < 0.1) associated with the density of smallholder farms (OR = 2.94; 0.82-10.59), volume of pork products' importation from ASF-affected regions of Russia (OR = 1.01; 1.00-1.02), summary pig population (OR = 1.01; 0.99-1.02), and insignificantly (p > 0.1) associated with presence of a common border with an ASF-affected region (OR = 89.2; 0.07-11208.64). No associations were found with the densities of pig and wild boar populations. The colocation analysis revealed no significant concentration of outbreaks in domestic pigs near cases in wild boar or vice versa. These results suggest that outbreaks notified in low biosecurity household farms were mainly associated with the transportation and trade of pigs and pork products from ASF-affected regions of Russia. The findings underline the importance of taking into account animal transportation data while conducting future studies to develop a risk map for the region and the rest of European Russia.

20.
Phys Chem Chem Phys ; 23(36): 20434-20443, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34494063

RESUMO

Memristors currently attract much attention as basic building blocks for future neuromorphic electronics. Due to their unusual electronic, optical, magnetic, electrochemical, and structural properties, transition metal oxides offer much potential in the development of memristors. Recent trends in the design and fabrication of electronic devices have led to miniaturization of their working elements, with nanometer-sized structures enjoying increasing demand. In the present study, we investigated resistive switching on individual vanadium oxide (V2O5) crystal-hydrate nanoparticles, 2 to 10 nm in size, encapsulated in fluorinated graphene (FG). Measurements using a conductive atomic force microscope (c-AFM) probe showed that the core-shell V2O5/FG nanoparticles make it possible to achieve bipolar resistive switching, reproducible during 104 switching cycles, with the ON/OFF current ratio reaching 103-105. The switching voltage of the structures depends on the thickness of the FG shells of the composite particles and equals ∼2-4 V. It is shown that the encapsulation of V2O5 particles in fluorinated graphene ensures a high stability of the resistive switching effect and, simultaneously, prevents the escape of water from the crystalline vanadium oxide hydrates. A qualitative model is proposed to describe the bipolar resistive switching effect in examined structures. Results reported in the present article will prove useful in creating bipolar nanoswitches.

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