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1.
RSC Adv ; 14(8): 5248-5263, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38344001

RESUMO

Photovoltaic (PV) materials, especially organic and perovskite solar cells are effective candidates for meeting the rising global energy demand. Herein, we have designed indolo[3,2-b]indole-based six molecules (IDF1-IDF6) as hole-transporting materials (HTMs) for perovskite solar cells (PSCs) and donor materials for organic solar cells (OSCs). The results demonstrated that IDF1-IDF6 molecules have tight π-π stacking, more negative HOMO levels (-5.50 to -5.31 eV), low bandgaps (1.91 to 2.41 eV), high absorption coefficients, large Stokes shifts, high open-circuit photovoltages (1.31 to 1.50 V), and superior solubility with comparable stability compared with the reference (IDFR) and Spiro-OMeTAD molecules. The high light-harvesting efficiency and low exciton binding energy indicated that IDF1-IDF6 molecules have a higher photocurrent flow ability. The electronic excitation analyses of studied molecules showed that the IDF1-IDF6 molecules show stronger exciton dissociation, low charge coupling, and high intrinsic charge transfer with sharper charge flow than IDFR and Spiro-OMeTAD. Moreover, the high hole hopping rate, high total amount of charge transfer, and low reorganization energy with comparable charge transfer integral demonstrated that the designed molecules have effective hole transport ability for solar cells. Our remarkable results demonstrated that IDF1-IDF6 are advantageous molecules for the manufacturing of efficient PSCs and OSCs, and may have future commercial applications in the solar industry.

2.
Redox Rep ; 29(1): 2319963, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38411133

RESUMO

Objectives: Distant liver injury is a complication of renal ischemia-reperfusion (I/R) injury, which imposes mortality and economic burden. This study aimed to elucidate the cross-talk of endoplasmic reticulum (ER) stress and mitochondrial perturbations in renal I/R-induced liver injury, and the potential hepatoprotective effect of azilsartan (AZL).Methods: Male albino Wister rats were pre-treated with AZL (3 mg/kg/day, PO) for 7 days then a bilateral renal I/R or sham procedure was performed. Activities of liver enzymes were assessed in plasma. The structure and ultra-structure of hepatocytes were assessed by light and electron microscopy. Markers of ER stress, mitochondrial biogenesis and apoptosis were analyzed in livers of rats.Results: Renal ischemic rats showed higher plasma levels of liver enzymes than sham-operated rats, coupled with histological and ultra-structural alterations in hepatocytes. Mechanistically, there was up-regulation of ER stress markers and suppression of mitochondrial biogenesis-related proteins and enhanced apoptosis in livers of renal ischemic rats. These abnormalities were almost abrogated by AZL pretreatment.Discussion: Our findings uncovered the involvement of mitochondrial perturbations, ER stress and apoptosis in liver injury following renal I/R, and suggested AZL as a preconditioning strategy to ameliorate remote liver injury in patients susceptible to renal I/R after adequate clinical testing.


Assuntos
Benzimidazóis , Nefropatias , Oxidiazóis , Traumatismo por Reperfusão , Humanos , Ratos , Masculino , Animais , Isquemia , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Fígado/metabolismo , Reperfusão , Apoptose , Estresse do Retículo Endoplasmático
3.
Nanomaterials (Basel) ; 13(20)2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37887915

RESUMO

Developing a sustainable environment requires addressing primitive water scarcity and water contamination. Antibiotics such as oxytetracycline (OTC) may accumulate in the environment and in the human body, increasing the risks to the ecosystem. The treatment of polluted water and the production of potable water can be achieved in a variety of ways, including photodegradation, solar distillation, and filtration. Freshwater supplies can be increased by implementing energy-efficient technologies for the production of clean water. Solar water evaporation combined with photocatalytic degradation and sterilization offers a promising avenue for integration into the clean water and energy production fields. The present study reports the synthesis of a 3D solar steam generator comprised of BiVO4 and carbon nanotubes (CNT) nanocomposite decorated over a cigarette filter as the light-to-heat conversion layer for solar steam generation. The BiVO4@CNT-based 3D solar evaporator over the hydrophilic cellulosic fibers of the cigarette filter endowed excellent evaporation rates (2.36 kg m-2 h-1) under 1 kW m-2 solar irradiation, owing to its superior hydrophilicity and broadband solar absorption (96%) equipped with localized heating at microscale thermal confinement optimized by the minimum thermal conductivity of the overall system. Furthermore, the BiVO4@CNT composite exhibited a heightened photo activity up to 83% of the photodegradation of oxytetracycline (OTC) antibiotic due to the inhibition of charge recombination from the industrial effluents. This approach transforms the water-energy nexus into a synergistic bond that offers opportunities to meet expected demand, rather than being competitive.

4.
J Mol Graph Model ; 125: 108588, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37557026

RESUMO

In this study, four hole-transporting materials (JY-M1, JY-M2, JY-M3, and JY-M4) are designed by modifying benzothiadiazole-based core with diphenylamine-based carbazole via acceptors through thiophene linkers. The designed molecules exhibited deeper HOMO energy with smaller energy gaps than the reference JY molecule which enhance their hole mobility. The absorption spectra of the JY-M1, JY-M2, JY-M3, and JY-M4 molecules are located at 380 nm to 407 nm in the gaseous phase and 397 nm to 433 nm in the solvent phase, which is red-shifted and higher than the reference molecule, demonstrating that designed molecules possess improved light absorption properties and enhanced effective hole transfer. The dipole moments of the designed molecules (14.74 D to 26.12 D) indicate a greater ability for charge separation, solubility and will be beneficial to produce multilayer films. Moreover, the results of hole reorganization energy (0.38198 eV to 0.45304 eV) and charge transfer integral (0.14315 eV to 0.14665 eV) of designing molecules show improved hole mobility and lower recombination losses compared to the JY molecule. Overall, we suggested that the structural modifications in the designed molecules contributed to their enhanced efficiency in converting light energy into electrical energy and have the potential for utilization in solar devices, paving the way for future advancements in the field of photovoltaics.


Assuntos
Difenilamina , Flúor , Eletricidade , Gases , Solubilidade
5.
PLoS One ; 18(7): e0285254, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37498917

RESUMO

This research aims to investigate the ballistic resistance of base material (BM)and "Friction Stir Welded (FSW)", AA5083 aluminum alloy. The primary objective was to build a finite element model to predict kinetic energy absorption and target deformation under single and multiple projectile impact conditions. This study employed 7.62mm Hard Steel Core (HSC) projectiles produced from Steel 4340. The target was analyzed using commercially available Abaqus Explicit software for Finite Element Analysis. It was noticed that the generation of kinetic energy and surface residual velocity increases as the number of projectile strikes increases. In addition, the experimental ballistic test was conducted to validate the numerical results. Using the analytical Recht-Ipson model, each target's experimental residual velocity was determined. It was determined that weldments perform less well (30%) as compared to BM targets. Occurrence of plastic deformation during welding causes reduction in ballistic performance of weldments. For both the computational and experimental approaches, a correlation between residual velocities was found. The plastic deformations with ductile hole formation were observed in all the cases.


Assuntos
Soldagem , Fricção , Ligas , Plásticos , Aço
6.
Heliyon ; 9(6): e16490, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37265617

RESUMO

In this communication irreversibility minimization in bio convective Walter's-B nanofluid flow by stretching sheet is studied. Suspended nanoparticles in Walter's-B fluid are stabilized by utilizing microorganisms. Total irreversibility is obtained via thermodynamics second law. The influences of applied magnetic field, radiation, Joule heating and activation energy are accounted in momentum, temperature and concentration equations. Furthermore thermophoresis and Brownian movement impacts are also accounted in concentration and temperature expressions. The flow governing dimensional equations are altered into dimensionless ones adopting transformation procedure. Homotopy Analysis Method (HAM) code in Mathematica is implemented to get the convergent series solution. The influences of important flow variables on temperature, velocity, motile density, irreversibility, mass concentration, Bejan number and physical quantities are analyzed graphically. The obtained results revel that the velocity profile decreases for escalating magnetic parameter and Forchheimer number. Entropy generation is increased for higher Brinkman variable while Bejan number declines versus Brinkman variable. The important observations are given at the end.

7.
Ultrastruct Pathol ; 47(4): 278-291, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37132626

RESUMO

One of the most widely used medications for epilepsy is the broad-spectrum antiseizure levetiracetam. The study aimed to evaluate the impact of levetiracetam on the bodyweight and liver of pregnant rats and their offspring. The study involved treating the rats during pregnancy and lactation and then examining the pregnant rats and their offspring. Two groups of 40 pregnant rats were created (I, II). Each group was split up into two smaller groups (A, B). About 1.5 mL/day of distilled water was gavaged to the rats in group I, either continuously throughout pregnancy (IA) or continuously throughout pregnancy and 15 days after delivery (IB). Group II rats received 1.5 ml/day of distilled water (containing levetiracetam) either during pregnancy (IIA) or during pregnancy plus 15 days postpartum (IIB). At the end of the work, blood samples were taken from the adult rats, body weight of different groups were recorded, and then, their liver was subjected for histological and morphometric analysis. Levetiracetam treatment showed reduction in the body weight of adult rats and their offspring and pathological changes in their liver. These changes were in the form of distortion of the hepatic architecture, cytoplasmic vacuolation, nuclear changes, and swollen mitochondria with loss of their cristae. Such changes were proved by alteration in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzyme levels of the liver. It is advised to monitor the liver functions continuously when using levetiracetam.


Assuntos
Fígado , Água , Gravidez , Feminino , Ratos , Humanos , Levetiracetam/farmacologia , Peso Corporal , Água/farmacologia , Animais
8.
RSC Adv ; 13(23): 15437-15447, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37223414

RESUMO

At high pressure, the pressure dependencies of the structural, electronic, optical, and thermoelectric properties of Fe2HfSi Heusler were calculated using the FP-LAPW method within the framework of the density functional theory. The calculations were carried out using the modified Becke-Johnson (mBJ) scheme. Our calculations showed that the Born mechanical stability criteria confirmed the mechanical stability in the cubic phase. Further, through Poisson and Pugh's ratios critical limits, the findings of the ductile strength were computed. At a pressure of 0 GPa, the indirect nature of the material may be deduced from the electronic band structures of Fe2HfSi as well as the estimations for its density of states. Under pressure, the real and imaginary dielectric function responses, optical conductivity, absorption coefficient, energy loss function, refractive index, reflectivity, and extinction coefficient were computed in the 0-12 eV range. Using semi-classical Boltzmann theory, a thermal response is also studied. As the pressure rises, the Seebeck coefficient decreases, while the electrical conductivity rises. The figure of merit (ZT) and Seebeck coefficients were determined at temperatures of 300 K, 600 K, 900 K, and 1200 K in order to better understand the thermoelectric properties of a material at these different temperatures. Despite the fact that the ideal Seebeck coefficient for Fe2HfSi was discovered at 300 K and was determined to be superior to that reported previously. Materials with a thermoelectric reaction has been shown to be suitable for reusing waste heat in systems. As a result, Fe2HfSi functional material may aid in the development of new energy harvesting and optoelectronic technologies.

9.
ACS Omega ; 8(15): 14005-14012, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37091401

RESUMO

In this article, the adsorption of NO x (x = 1, 2) gas molecules on the (001) surface of CoFeMnSi quaternary Heusler alloys has been investigated theoretically with density functional theory (DFT) calculations. The adsorption strength was estimated with adsorption energy (E a), magnitude of charge transfer (ΔQ), charge density difference (CDD), minimum distance between molecule and surface (d), and adsorption mechanism was analyzed with density of states. The results showed that unlike half-metallic nature of the bulk phase, the pristine CoFeMnSi(001) surface exhibited metallic character caused by the emergence of electronic states of the atoms in the top-most layer of the surface. It was found that both NO and NO2 molecules undergo chemical adsorption and strongly interact with the surface evidenced by the large value of E a and ΔQ. In particular, the NO x molecule dissociates into N and O atoms for some adsorption configurations. Bader charge analysis reveals that NO x molecules act as charge acceptors by drawing charge from the surface atoms through p-d hybridization. Such findings might be useful in the development of Heusler alloys based gas sensors.

10.
J Mol Graph Model ; 122: 108464, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37087884

RESUMO

This study focuses on the creation of 5 small donor molecules (A102W1-A102W5) by substituting the one-sided methoxy group of model (A102R) with different thiophene bridged acceptor moieties. B3LYP/6-31**G (d,p) model has been employed for computational analysis. The best miscibility was found for A102W3 in dichloromethane (DCM) solvent, where its λmax was also found to be at 753 nm, its Eg was found to be 1.55 eV as well as dipole moment in DCM was 21.47 D. The percentage of PCE among all the variants was greatest for A102W2 (25.31%). The electron reorganization energy shown by A102W4 was 0.00470 eV, whereas the hole reorganization energy investigated in A102W2 was 0.00586 eV representing their maximum electron and hole mobility respectively amongst all. Results validate the value of specified techniques, opening a new door to create efficient small donors for OSCs and HTMs for PSCs.


Assuntos
Aminas , Antracenos , Compostos de Cálcio , Cloreto de Metileno
11.
Ultrason Sonochem ; 95: 106382, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37031535

RESUMO

BACKGROUND: This study, for the first time, reports a simultaneous determination of flavonoids; rutin (RT), quercetin (QT), luteolin (LT), and kaempferol (KF) in different origins of fenugreek seeds samples (N = 45) using a green UHPLC-DAD analysis METHODOLOGY: Ultrasound-assisted extraction (UAE) was employed to extract fenugreek flavonoids using different polarity solvents of n-hexane (n-hex), dichloromethane (DCM), and methanol (MeOH) RESULTS: The extract yield on an individual basis was observed in the range of 1.03-17.29 mg, with the highest yield (mg/sample) for the Egyptian sample (17.29 mg). The highest total extract yield (mg/origin) was observed for the Iranian sample (82.28 ±â€¯5.38). The solvent with the highest extract yield (mg) was n-hex 169.35 ±â€¯13.47, followed by MeOH 114.39 ±â€¯12.27. The validated green UHPLC-DAD method resulted in a short runtime (9 min) with an accuracy of 97.86(±12.32)-101.37(±5.91), r2-values = 0.993-0.999, LOD = 2.09-4.48 ppm, and LOQ = 6.33-13.57 ppm for flavonoids analysis within the linearity range of 1-500 ppm. The general yield for flavonoids exhibited a descending order (ppm): RT (2924.55 ±â€¯143.84) > QT (457.05 ±â€¯34.07) > LT (82.37 ±â€¯3.27) > KF (4.54 ±â€¯0.00). The yield (ppm) for the flavonoids was more in MeOH solvent (3424.81 ±â€¯235.44) constructing a descending order of MeOH > n-hex > DCM. For an individual flavonoid yield; MeOH was seen with an order of RT > QT > LT, n-hex (LT > QT), and DCM (RT > LT > QT). The statistical analysis of PCA (principle component analysis) revealed a widespread distribution of flavonoids in fenugreek seeds with a variance of 35.93% (PC1). Moreover, flavonoids extraction was prone to the nature and specificity of the solvent used (PC2: 33.34%) rather than the amount of the extract yield (P = 0.00). The K-mean cluster analysis showed the origins with higher flavonoids yield in appropriate solvent as I3M (Indian accession # 3 MeOH extract) with more QT amount, IR2M (Iranian accession # 2 MeOH extract) with more LT amount along with I2M (Indian accession # 2 MeOH extract) and Q2M (Qassim Saudi Arabia accession # 2 MeOH extract) containing high amount of RT. The outcomes are supported by KMO (Kaiser-Meyer-Olkin) and Bartlett's test value of 0.56 with X2-value of 191.87 (P = 0.00) CONCLUSION: The samples were effectively evaluated and standardized in terms of flavonoid amount suggesting a significant variation in fenugreek quality.


Assuntos
Flavonoides , Trigonella , Flavonoides/análise , Cromatografia Líquida de Alta Pressão/métodos , Ultrassom , Irã (Geográfico) , Extratos Vegetais , Quercetina/análise , Rutina/análise , Solventes , Metanol
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 298: 122774, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37120955

RESUMO

In this study, a series of highly efficient organic hole-transporting materials (HTMs) were designed using Schiff base chemistry by modifying a phenothiazine-based core with triphenylamine through end-capped acceptor engineering via thiophene linkers. The designed HTMs (AZO1-AZO5) exhibited superior planarity and greater attractive forces, making them ideal for accelerated hole mobility. They also showed deeper HOMO energy levels (-5.41 eV to -5.28 eV) and smaller energy band gaps (2.22 eV to 2.72 eV), which improved charge transport behavior, open-circuit current, fill factor, and power conversion efficiency of perovskite solar cells (PSCs). The dipole moments and solvation energies of the HTMs revealed their high solubility, making them suitable for the fabrication of multilayered films. The designed HTMs showed tremendous enhancements in power conversion efficiency (26.19 % to 28.76 %) and open-circuit voltage (1.43 V to 1.56 V), with higher absorption wavelength than the reference molecule (14.43 %). Overall, the Schiff base chemistry-driven design of thiophene-bridged end-capped acceptor HTMs is highly effective in enhancing the optical and electronic properties of perovskite solar cells.

13.
J Mol Graph Model ; 122: 108486, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37080003

RESUMO

Organic solar cells (OSCs) are capturing huge interest because of their numerous benefits, which include transparency, flexibility, and solution processability. In current project, five new donor molecules (J1-J5) were designed by employing the strategy of end capped alteration of the acceptor moieties on the two sides of the reference molecule. The Methoxy Triphenylamine hexaazatrinaphthylene (MeO-TPA-HATNA) have been used as a reference molecule in this study. DFT and TD-DFT methods employing B3LYP/6-31G (d, p) functional has been applied to perform different analysis. Geometrical, and opto-electronic features of all tailored chromophores were investigated, and comparison was made with the reference J. Among all tailored molecules, J5 shows highest λmax (862 nm) with the least band gap of 1.28 eV. TDM and DOS analysis revealed the high rate of charge transfer. Further, reorganization energy calculations are also executed to examine the charge transfer features of the designed molecules. The results shows that J5 among all these molecules has the highest rate of charge carrier (electron and hole) mobility with least RE values and this molecule can be used as a promising donor material for OSCs with remarkable charge transferring properties. Furthermore, the designed materials showed a suitable HOMO along with higher LUMO energy levels with respect to PC61BM molecule and coupling the PC61BM acceptor with investigated donor molecules gives highly increased Voc (0.66-0.76 V) than reference molecule (0.49 V) and also the power conversion efficiency (PCE) is elevated to 15.09%. The outcomes of current theoretical research have demonstrated that the end capped alteration of different acceptor groups is an excellent strategy to get OSCs with desirable photovoltaic performance. As, all the newly created molecules (J1-J5) have exhibited outstanding electronic and optical properties therefore, these can be expectedly prove excellent material for creating high efficiency future organic photovoltaic devices.


Assuntos
Aminas , Eletrônica , Teoria da Densidade Funcional , Elétrons
14.
Bioengineering (Basel) ; 9(12)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36550964

RESUMO

More than the half of the global population consume rice as their primary energy source. Therefore, this work focused on the development of a prediction model to minimize agricultural loss in the paddy field. Initially, rice plant diseases, along with their images, were captured. Then, a big data framework was used to encounter a large dataset. In this work, at first, feature extraction process is applied on the data and after that feature selection is also applied to obtain the reduced data with important features which is used as the input to the classification model. For the rice disease datasets, features based on color, shape, position, and texture are extracted from the infected rice plant images and a rough set theory-based feature selection method is used for the feature selection job. For the classification task, ensemble classification methods have been implemented in a map reduce framework for the development of the efficient disease prediction model. The results on the collected disease data show the efficiency of the proposed model.

15.
RSC Adv ; 12(27): 17228-17236, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35755593

RESUMO

Mesoporous silicon (mSi) obtained by the magnesiothermic reduction of mesoporous silica was used to deposit polyaniline (PANI) in its pores, the composite was tested for its charge storage application for high performance supercapacitor electrodes. The mesoporous silica as confirmed by Small Angle X-ray Scattering (SAXS) has a Brunauer-Emmett-Teller (BET) surface area of 724 m2g-1 and mean pore size of 5 nm. After magnesiothermic reduction to mSi, the BET surface area is reduced to 348 m2g-1 but the mesoporousity is retained with a mean pore size of 10 nm. The BET surface area of mesoporous silicon is among the highest for porous silicon prepared/reduced from silica. In situ polymerization of PANI inside the pores of mSi was achieved by controlling the polymerization conditions. As a supercapacitor electrode, the mSi-PANI composite exhibits better charge storage performance as compared to pure PANI and mesoporous silica-PANI composite electrodes. Enhanced electrochemical performance of the mSi-PANI composite is attributed to the high surface mesoporous morphology of mSi with a network structure containing abundant mesopores enwrapped by an electrochemically permeable polyaniline matrix.

16.
J Appl Biomater Funct Mater ; 20: 22808000221094685, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35531919

RESUMO

Investigation of heat transport mechanism in swirling flow of viscous fluid containing silicon dioxide (SiO2) and molybdenum disulfide (MoS2) nanoparticles is performed. The flow is engendered due to stretchable rotating cylinder which immersed in infinite fluid. The boundary layer assumption is applied to simplify the governing equations of the problem. The theory of Cattaneo-Christov for thermal energy transportation is employed in the present phenomenon under the heat and mass constraints. The flow is also influenced by Lorentz force. The results for flow field, temperature, and concentration field are produced by employing the bvp4c numerical technique to the similar differential equations. According to the observations, it is noted that in the presence of Lorentz force the reduction in velocity field of the nanofluid occurs. The thermal and solutal relaxation phenomena also declines the energy transport in nanofluid flow. The outcomes are validated through the comparison with previous published studies.


Assuntos
Nanopartículas , Dióxido de Silício , Temperatura Alta , Molibdênio , Viscosidade
17.
Front Public Health ; 10: 796321, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35558536

RESUMO

Objectives: This study aimed to investigate the technostress creators and outcomes among University medical and nursing faculties and students as direct effects of the remote working environment during the COVID-19 pandemic. Background: Due to the current COVID-19 pandemic, shifting to virtual learning that implies utilizing the information and communication technologies (ICTs) is urgent. Technostress is a problem commonly arising in the virtual working environments and it occurs due to misfitting and maladaptation between the individual and the changeable requirements of ICTs. Methods: A multicenter cross-sectional study was conducted in medicine and nursing colleges of 5 Egyptian universities and included both staff members and students. The data were collected through personal interviews, from January to May 2021. All the participants took a four-part questionnaire that asked about personal and demographic data, technostress creators, job or study, and technical characteristics and technostress outcomes (burnout, strain, and work engagement). Furthermore, participants' blood cortisol and co-enzyme Q10 (CoQ10) levels were tested in a random sample of the students and medical staff. Results: A total of 3,582 respondents participated in the study, 1,056 staff members and 2,526 students where 33.3% of the staff members and 7.6% of students reported high technostress. Among staff members, total technostress score significantly predicted Cortisol level (ß = 2.98, CI 95%: 0.13-5.83), CoQ10(ß = -6.54, CI 95%: [(-8.52)-(-4.56), strain (ß = 1.20, CI 95%: 0.93-1.47), burnout (ß = 0.73, CI 95%: 0.48-0.97) and engagement (ß = -0.44, CI 95%: [(-0.77)-(-0.11)]) whereas among students, total technostress score significantly predicted cortisol level (ß = 6.64, CI 95%: 2.78-10.49), strain (ß = 1.25, CI 95%: 0.72-1.77), and burnout (ß = 0.70, CI 95%: 0.37-1.04). Among staff members and students, technology characteristics were significantly positive predictors to technostress while job characteristics were significantly negative predictors to technostress. Conclusion: The Egyptian medical staff members and students reported moderate-to-high technostress which was associated with high burnout, strain, and cortisol level; moreover, high technostress was associated with low-work engagement and low CoQ10 enzyme. This study highlighted the need to establish psychological support programs for staff members and students during the COVID-19 pandemic.


Assuntos
Esgotamento Profissional , COVID-19 , Esgotamento Profissional/epidemiologia , COVID-19/epidemiologia , Estudos Transversais , Egito/epidemiologia , Humanos , Hidrocortisona , Corpo Clínico , Pandemias , Estudantes , Teletrabalho
18.
RSC Adv ; 12(13): 8172-8177, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35424713

RESUMO

In the scheme of density functional theory (DFT), Structural, elastic, electronic, and optical properties calculations of GaBeCl3 and InBeCl3 are carried out using Tran-Blaha modified Becke-Johnson exchange potential approximation (TB-mBJ) installed in Wein2k software. Structurally the compounds of interest are found to be stable. Both compounds possess elastic stability, anisotropy, and ductility determined by the elastic studies. The electronic-band structure analysis shows the semiconductor nature of GaBeCl3 and InBeCl3 compounds with indirect band gaps of ∼3.08 eV for GaBeCl3 and ∼2.04 eV for InBeCl3 along with the symmetrical points from (X-Γ). The calculated total density of states (TDOS) and partial density of states (PDOS) of these compounds reveal that for the GaBeCl3 compound, the contribution of Ga (4p) and Cl (3p) orbital states in the valence, as well as the conduction band, is dominant. While for InBeCl3, the contribution of Cl (3p) states as well as In (5s) is large in the valence band and in that of Cl (3p-states) states in the conduction band. The type of chemical bonding is found to be ionic in both compounds. The optical properties i.e., the real (ε 1(ω)) and imaginary (ε 2(ω)) parts of dielectric function, refractive index n(ω), optical reflectivity R(ω), optical conductivity σ(ω), absorption coefficient α(ω), energy loss L(ω) and electron extinction coefficient k(ω) are also discussed in terms of optical spectra. It is reported that n(ω) and k(ω) exhibit the same characteristics as ε 1(ω) and ε 2(ω) respectively. Efficient application of these materials can be seen in semiconducting industries and many modern electronic devices.

20.
J Mech Behav Biomed Mater ; 127: 105070, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35074734

RESUMO

The purpose of current work of is to organize stabilized tetragonal zirconia (t-ZrO2) nano-particles with microwave abetted sol-gel technique. To increase the stability and shrink the crystal size, both microwave (MW) and gelatin components are used as structure guiding methods. Gelatin was used with the aim of bone implantations, as raw materials used in gelatin production are cattle bones. It contains purified collagen protein (a main protein that in the extracellular matrix found in the body's various connective tissues) that also helps in implantations and repairing. Moreover, MW heating provides a uniform heating and control of microstructures. Zirconium oxychloride was used as precursor of zirconium Effect of gelatin contents (1g, 2g, 3g, 4g and 5g) was observed. X-ray diffraction (XRD) analysis attributes the presence of phase pure t-ZrO2 at low gelatin content 3g with crystallite size ∼6.68296 nm. Formation of phase pure t-ZrO2 without post heat treatment is due to sufficient amount of gelatin to coat the zirconia crystals. Relatively higher x-ray density has been observed in case of phase pure t-ZrO2 at 5g of gelatin content. Value of the hardness is increasing from 1263 to 1443 HV with gelatin content due to phase strengthening. Raman shift presents characteristic peak at 148 cm-1 of tetragonal zirconia. Phase fraction calculated from Raman spectra is in good agreement with XRD data. At 3g of gelatin content porous structure has been observed in scanning electron microscope images. This porosity decreases with gelatin content and the distribution of particles is more uniform, and dispersion is better. The porosity of the samples decreases and reaching a minimum value at 5g of gelatin content, at which the sample was the densest. The size of nanoparticles is in the range of 500-600 nm. Optimized t-ZrO2 is soaked in stimulated body fluid (SBF) for 1, 2, 4, 8, 12, 18 and 24 weeks. Slight variation in weight and hardness has been observed even after 24 weeks of soaking.


Assuntos
Nanopartículas , Zircônio , Animais , Bovinos , Gelatina , Micro-Ondas , Nanopartículas/química , Zircônio/química
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