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1.
J Mech Behav Biomed Mater ; 154: 106511, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38518512

RESUMO

The extraordinary quasi-static mechanical properties of nacre-like composite metamaterials, such as high specific strength, stiffness, and toughness, are due to the periodic arrangement of two distinct phases in a "brick and mortar" structure. It is also theorized that the hierarchical periodic structure of nacre structures can provide wider band gaps at different frequency scales. However, the function of hierarchy in the dynamic behavior of metamaterials is largely unknown, and most current investigations are focused on a single objective and specialized applications. Nature, on the other hand, appears to develop systems that represent a trade-off between multiple objectives, such as stiffness, fatigue resistance, and wave attenuation. Given the wide range of design options available to these systems, a multidisciplinary strategy combining diverse objectives may be a useful opportunity provided by bioinspired artificial systems. This paper describes a class of hierarchically-architected block lattice metamaterials with simultaneous wave filtering and enhanced mechanical properties, using deep learning based on artificial neural networks (ANN), to overcome the shortcomings of traditional design methods for forward prediction, parameter design, and topology design of block lattice metamaterial. Our approach uses ANN to efficiently describe the complicated interactions between nacre geometry and its attributes, and then use the Bayesian optimization technique to determine the optimal geometry constants that match the given fitness requirements. We numerically demonstrate that complete band gaps, that is attributed to the coupling effects of local resonances and Bragg scattering, exist. The coupling effects are naturally influenced by the topological arrangements of the continuous structures and the mechanical characteristics of the component phases. We also demonstrate how we can tune the frequency of the complete band gap by modifying the geometrical configurations and volume fraction distribution of the metamaterials. This research contributes to the development of mechanically robust block lattice metamaterials and lenses capable of controlling acoustic and elastic waves in hostile settings.


Assuntos
Nácar , Nácar/química , Teorema de Bayes , Som , Acústica
2.
Ann Otol Rhinol Laryngol ; 133(2): 196-204, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37688447

RESUMO

BACKGROUND: The defects of the upper third of the auricle are considered significant reconstructive challenges, as they require frequent operations with a high risk of morbidity at the donor site and result in unacceptable cosmetic abnormalities. OBJECTIVE: Is to perform the reconstruction of a full-thickness auricular defect located in the upper third of the ear using a conchal cartilage graft with postauricular flap coverage, aiming to minimize both donor and recipient morbidity. PATIENTS AND METHODS: The current study included 20 patients with unilateral upper-third auricular defects. The repair involved 2 components: a cartilage graft from the concha to provide structural support and a flap for coverage. Follow-up was conducted for 6 months after the operation. RESULTS: Successful outcomes were achieved in both subjective and doctors' assessments. Regarding subjective outcomes, 85% of the patients reported high satisfaction (P < .001). In terms of doctors' subjective assessment, 90% of the patients had excellent results (P < .001). Mild early and postoperative complications, if encountered, resolved spontaneously. CONCLUSION: The use of a combined conchal cartilage graft and postauricular flap in treating a full-thickness upper third auricular defect is safe and effective, with no major complications. The technique preserves the cosmetic and functional outcomes of the auricle, providing an excellent color match and minimal donor-site morbidity.


Assuntos
Pavilhão Auricular , Procedimentos de Cirurgia Plástica , Humanos , Retalhos Cirúrgicos , Orelha Externa/cirurgia , Pavilhão Auricular/cirurgia , Cartilagem
3.
Phys Chem Chem Phys ; 26(3): 1994-2006, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38116761

RESUMO

We investigate the damping effects of coherent electron oscillations on the bandwidth of a quantized nanoparticle plasmon resonance. The nanoparticle (NP) is treated as a two-level quantum system, and the total relaxation time involves both the population relaxation time associated with radiative processes and the collisional relaxation time associated with nonradiative processes that result in dephasing/decoherence of electron oscillations. We describe the optical response of NPs to an external electromagnetic field by the optical Bloch equations employing the density matrix formalism to capture the quantum description nature of dipolar plasmon resonance and suggest a generalized criterion for the validity of dipole approximation. Then we explore the competition between the radiative and nonradiative damping in determining the plasmon bandwidth of two typical NP models; metallic nanospheres and dielectric core-metal shell NPs (nanoshells). We show that the frequency of plasmon resonance, in addition to the NP size, plays an important role in the competition between the damping mechanisms. Consequently, the damping processes are significantly influenced by the factors that determine the resonance frequency, such as the core size, the dielectric constant of the medium, and the shell thickness (for nanoshells). For both models of NPs, we identify the optimum parameters that achieve a narrower plasmon bandwidth (minimal damping), which is a prerequisite for advanced sensing and medical applications. We demonstrate excellent agreement of the simulated spectral features of the plasmon resonance with previously reported experimental results for a single NP where the inhomogeneous broadening of the plasmon line is excluded. For NP ensembles where inhomogeneous broadenings and interface chemical effects are significant, our theoretical approach successfully predicts the overall trend of size-dependent damping rates.

4.
J Cardiovasc Electrophysiol ; 34(12): 2504-2513, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37822117

RESUMO

INTRODUCTION: Despite undergoing an index ablation, some patients progress from paroxysmal atrial fibrillation (PAF) to persistent AF (PersAF), and the mechanism behind this is unclear. The aim of this study was to investigate the predictors of progression to PersAF after catheter ablation in patients with PAF. METHODS: This study included 400 PAF patients who underwent an index ablation between 2015 and 2019. The patients were classified into three groups based on their outcomes: Group 1 (PAF to sinus rhythm, n = 226), Group 2 (PAF to PAF, n = 146), and Group 3 (PAF to PersAF, n = 28). Baseline and procedural characteristics were collected, and predictors for AF recurrence and progression were evaluated. RESULTS: The mean age of the patients was 58.4 ± 11.1 years, with 272 males. After 3 years of follow-up, 7% of the PAF cases recurred and progressed to PersAF despite undergoing an index catheter ablation. In the multivariable analysis, a larger left atrial (LA) diameter and the presence of non-pulmonary vein (PV) triggers during the index procedure independently predicted recurrence. Moreover, a larger LA diameter, the presence of non-PV triggers, and a history of thyroid disease independently predicted AF progression. CONCLUSION: The progression from PAF to PersAF after catheter ablation is associated with a larger LA diameter, history of thyroid disease, and the presence of non-PV triggers. Meticulous preprocedural evaluation, patient selection, and comprehensive provocation tests during catheter ablation are recommended.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Doenças da Glândula Tireoide , Masculino , Humanos , Pessoa de Meia-Idade , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Resultado do Tratamento , Veias Pulmonares/cirurgia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Recidiva
5.
Pharmaceutics ; 15(10)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37896146

RESUMO

Propolis is a naturally occurring substance with beneficial properties; bees produce it from various plant sources, and it is an anti-inflammatory and therapeutic resinous substance. This study aimed to enhance the biological features of propolis extract by loading it onto active film. Firstly, extraction was performed using three solvent systems, and their total phenolic, flavonoid, and antioxidant activity was measured. Propolis ethanol extract (EEP) was evaluated for phenolic fraction content and then chosen to prepare a chitosan-loaded emulsion with several concentrations. The antibacterial, anti-mycotic, and anti-mycotoxigenic properties of the extract and nanoemulsion were assessed. PPE's cytotoxicity and nanoemulsion were evaluated using brine shrimp and cell line assays. Results indicate higher phenolic (322.57 ± 4.28 mg GAE/g DW), flavonoid (257.64 ± 5.27 mg QE/g DW), and antioxidant activity of the EEP. The phenolic fraction is distinguished by 18 phenolic acids with high p-hydroxybenzoic content (171.75 ± 1.64 µg/g) and 12 flavonoid compounds with high pinocembrin and quercetin content (695.91 ± 1.76 and 532.35 ± 1.88 µg/g, respectively). Phenolic acid derivatives (3,4-Dihydroxybenzaldehyde, 3,4-Dihydroxyphenol acetate, and di-methoxy cinnamic) are also found. Concentrations of 50, 100, 150, and 200 ng EEP loaded on chitosan nanoemulsion reflect significant antibacterial activity against pathogenic bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA) and toxigenic fungi, particularly Fusarium. Among the four EEP-loaded concentrations, the nanoemulsion with 150 ng showed outstanding features. Using a simulated medium, 150 and 200 ng of EEP-loaded chitosan nanoemulsion concentrations can stop zearalenone production in Fusarium media with complete fungi inhibition. Also, it reduced aflatoxins production in Aspergillus media, with fungal inhibition (up to 47.18%). These results recommended the EEP-chitosan application for pharmaceutics and medical use as a comprehensive wound healing agent.

6.
Emerg Radiol ; 30(4): 419-423, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37273151

RESUMO

INTRODUCTION: Grey Scale Inversion Imaging (GSII), a radiology reading software, has been utilized to improve anatomical and pathological delineation and consequently increase the diagnostic accuracy in a variety of trauma and Orthopaedic conditions. OBJECTIVE/AIM: The objective of this study was to assess whether Grey Scale Inversion Imaging (GSII) has any impact on the diagnostic accuracy and inter-observer reliability in diagnosing neck of femur fractures. METHOD: We performed a retrospective, single-centre study, to identify 50 consecutive anteroposterior (AP) pelvis radiographs of patients who presented to our unit with suspected neck of femur fractures between 2020 and 2021. The images included a combination of normal pelvic radiographs and others with features suggestive either intracapsular or extracapsular neck of femur fractures, which had been confirmed on computed tomography (CT), magnetic resonance imaging (MRI) and/or subsequent surgery. Four independent observers (two Trauma and Orthopaedics (T&O) consultants, one T&O Trainee Registrar (ST3 level) and one Trainee Senior House Officer (SHO in T&O) reviewed the images and graded each radiograph image using the Likert scale in response to the statement "there is a fracture". Following this, the same radiographs were inverted to Grey Scale Inversion Imaging (GSII) grey scale images and reassessed. RAND correlation was used for statistical analysis. RESULTS: Overall, observers appeared to have similar accuracy with normal radiographic imaging and with GSI sequences. CONCLUSION: Grey Scale Inversion Imaging (GSII) of digital radiographs did not affect the diagnostic accuracy of detecting neck of femur fractures in our study.


Assuntos
Fraturas do Fêmur , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fraturas do Fêmur/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Fêmur , Variações Dependentes do Observador
7.
Materials (Basel) ; 16(8)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37109916

RESUMO

The microstructural, electrical, and optical properties of Cu-doped and undoped ZnTe thin films grown on glass substrates are covered in this article. To determine the chemical makeup of these materials, both energy-dispersive X-ray (EDAX) spectroscopy and X-ray photoelectron spectroscopy were employed. The cubic zinc-blende crystal structure of ZnTe and Cu-doped ZnTe films was discovered using X-ray diffraction crystallography. According to these microstructural studies, the average crystallite size increased as the amount of Cu doping increased, whereas the microstrain decreased as the crystallinity increased; hence, defects were minimized. The Swanepoel method was used to compute the refractive index, and it was found that the refractive index rises as the Cu doping levels rises. The optical band gap energy was observed to decrease from 2.225 eV to 1.941 eV as the Cu content rose from 0% to 8%, and then slightly increase to 1.965 eV at a Cu concentration of 10%. The Burstein-Moss effect may be connected to this observation. The larger grain size, which lessens the dispersion of the grain boundary, was thought to be the cause of the observed increase in the dc electrical conductivity with an increase in Cu doping. In structured undoped and Cu-doped ZnTe films, there were two carrier transport conduction mechanisms that could be seen. According to the Hall Effect measurements, all the grown films exhibited a p-type conduction behavior. In addition, the findings demonstrated that as the Cu doping level rises, the carrier concentration and the Hall mobility similarly rise, reaching an ideal Cu concentration of 8 at.%, which is due to the fact that the grain size decreases grain boundary scattering. Furthermore, we examined the impact of the ZnTe and ZnTe:Cu (at Cu 8 at.%) layers on the efficiency of the CdS/CdTe solar cells.

8.
Materials (Basel) ; 16(6)2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36984104

RESUMO

After (In1-xGdx)2O3 powder with a wide x range of 0 to 10 at.% was chemically produced, (In1-xGdx)2O3 thin films were evaporated under ultra-vacuum using an electron beam apparatus. We investigated the influence of the Gd doping concentration on the magnetic, optical, electrical, and structural properties of the resultant In2O3 deposits. The produced Gd-doped In2O3 films have a cubic In2O3 structure without a secondary phase, as shown by the X-ray diffraction results. Additionally, the chemical analysis revealed that the films are nearly stoichiometric. A three-layer model reproduced the spectroscopic ellipsometer readings to determine the optical parameters and energy gap. The Egopt changed toward the lower wavelength with growing the Gd doping in (In1-xGdx)2O3 films. The Egopt in the (In1-xGdx)2O3 films was observed to increase from 3.22 to 3.45 eV when the Gd concentration climbed. Both carrier concentration and hall mobility were found during the Hall effect studies. It was possible to construct the heterojunction of Ni (Al)/n-(In1-xGdx)2O3/p-Si/Al. At voltages between -2 and 2 volts, investigations into the dark (cutting-edge-voltage) characteristics of the produced heterojunctions were made. The oxygen vacancies and cationic defects in the lattice caused by the uncompensated cationic charges resulted in significant magnetism and ferromagnetic behavior in the undoped In2O3 films. The (In1-xGdx)2O3 films, however, displayed faint ferromagnetism. The ferromagnetism seen in the (In1-xGdx)2O3 films was caused by oxygen vacancies formed during the vacuum film production process. Metal cations created ferromagnetic exchange interactions by snatching free electrons in oxygen.

9.
J Cardiol ; 81(5): 434-440, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36372323

RESUMO

BACKGROUND: The neuromodulation effect after ventricular arrhythmia (VA) ablation is unclear. The study aimed to investigate skin sympathetic nerve activity (SKNA) changes in patients receiving catheter ablations for idiopathic VA. METHODS: Of 43 patients with drug-refractory symptomatic VA receiving ablation, SKNA was continuously recorded for 10 min during resting from electrocardiogram lead I configuration and bipolar electrodes on the right arm 1 day before and 1 day after ablation. RESULTS: Twenty-two patients with acute procedure success and no recurrence during follow-ups were classified as sustained success group (group 1). Other 21 patients were classified as failed ablation group (group 2). Baseline SKNA showed no significant difference between the two groups. Post-ablation SKNA in group 2 was significantly higher than in group 1. In patients with ablation involved right ventricular outflow tract (RVOT), the post-ablation SKNA was also significantly higher in group 2. In contrast, there was no difference in post-ablation SKNA between groups in patients receiving non-RVOT ablation. CONCLUSION: The neuromodulation response after RVOT ablation may correspond to the sympathetic nerve distribution at RVOT. Augmentation of sympathetic activity after VA ablation indicates an unsuccessful VA suppression, especially in patients receiving ablation of RVOT VA.


Assuntos
Ablação por Cateter , Taquicardia Ventricular , Humanos , Arritmias Cardíacas , Ventrículos do Coração , Ablação por Cateter/métodos , Sistema Nervoso Simpático/cirurgia , Pele , Eletrocardiografia , Taquicardia Ventricular/cirurgia , Resultado do Tratamento
10.
Int J Mol Sci ; 23(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36430541

RESUMO

Adrenomedullin, a peptide with vasodilatory, natriuretic, and diuretic effects, may be a novel agent for treating heart failure. Heart failure is associated with an increased risk of atrial fibrillation (AF), but the effects of adrenomedullin on atrial arrhythmogenesis remain unclear. This study investigated whether adrenomedullin modulates the electrophysiology of the atria (AF substrate) or pulmonary vein (PV; AF trigger) arrhythmogenesis. Conventional microelectrode or whole-cell patch clamps were used to study the effects of adrenomedullin (10, 30, and 100 pg/mL) on the electrical activity, mechanical response, and ionic currents of isolated rabbit PV and sinoatrial node tissue preparations and single PV cardiomyocytes. At 30 and 100 pg/mL, adrenomedullin significantly reduced the spontaneous beating rate of the PVs from 2.0 ± 0.4 to 1.3 ± 0.5 and 1.1 ± 0.5 Hz (reductions of 32.9% ± 7.1% and 44.9 ± 8.4%), respectively, and reduced PV diastolic tension by 12.8% ± 4.1% and 14.5% ± 4.1%, respectively. By contrast, adrenomedullin did not affect sinoatrial node beating. In the presence of L-NAME (a nitric oxide synthesis inhibitor, 100 µM), adrenomedullin (30 pg/mL) did not affect the spontaneous beating rate or diastolic tension of the PVs. In the single-cell experiments, adrenomedullin (30 pg/mL) significantly reduced the L-type calcium current (ICa-L) and reverse-mode current of the sodium-calcium exchanger (NCX). Adrenomedullin reduces spontaneous PV activity and PV diastolic tension by reducing ICa-L and NCX current and thus may be useful for treating atrial tachyarrhythmia.


Assuntos
Fibrilação Atrial , Insuficiência Cardíaca , Veias Pulmonares , Animais , Coelhos , Adrenomedulina/farmacologia , Átrios do Coração
11.
Circ J ; 87(1): 84-91, 2022 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-36130901

RESUMO

BACKGROUND: Radiofrequency catheter ablation (RFCA) is commonly performed in patients with non-paroxysmal atrial fibrillation (AF), but because very long-term follow-up results of RFCA are limited, we investigated the 10-year RFCA outcomes of non-paroxysmal AF.Methods and Results: We retrospectively enrolled 100 patients (89 men, mean age 53.5±8.4years) with drug-refractory symptomatic non-paroxysmal AF who underwent 3D electroanatomic-guided RFCA. Procedural characteristics at index procedures and clinical outcomes were investigated. In the index procedures, all patients had pulmonary vein isolation, 56 (56.0%), 48 (48.0%), and 32 (32.0%) underwent additional linear, complex fractionated atrial electrogram (CFAE) and non-pulmonary vein (NPV) foci ablations, respectively. After 124.1±31.7 months, 16 (16%) patients remained in sinus rhythm after just 1 procedure (3 with antiarrhythmic drugs [AAD]) and after multiple (2.1±1.3) procedures in 53 (53.0%) patients (22 with AAD). Left atrial (LA) diameter (hazard ratio HR 1.061; 95% confidence interval (CI) 1.020 to 1.103; P=0.003), presence of NPV triggers (HR 1.634; 95% CI 1.019 to 2.623; P=0.042) and undergoing CFAE ablation (HR 2.003; 95% CI 1.262 to 3.180; P=0.003) in the index procedure were independent predictors for recurrent atrial tachyarrhythmia. CONCLUSIONS: The 10-year outcomes of single RFCA in non-paroxysmal AF were unsatisfactory. Enlarged LA, presence of NPV triggers, and undergoing CFAE ablation in the index procedure independently predicted single-procedure recurrence. Multiple procedures are required to achieve adequate rhythm control.


Assuntos
Apêndice Atrial , Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Masculino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Átrios do Coração , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Antiarrítmicos/uso terapêutico , Veias Pulmonares/cirurgia , Recidiva , Resultado do Tratamento
12.
J Pers Med ; 12(8)2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-36013235

RESUMO

Autonomic system plays a pivotal role in the pathogenesis of paroxysmal atrial fibrillation (AF). Skin sympathetic nerve activity (SKNA) is a noninvasive tool for assessing sympathetic tone. However, data on changes in SKNA after ablation are limited. Here, we retrospectively enrolled 37 patients with symptomatic drug-refractory paroxysmal AF who underwent pulmonary vein isolation (PVI) with radiofrequency ablation (RFA) or cryoablation (CBA). SKNA was measured from the chest and right arm 1 day prior to ablation, as well as 1 day and 3 months after ablation. One day after ablation, the SKNA-Arm increased from 517.1 µV (first and third quartiles, 396.0 and 728.0, respectively) to 1226.2 µV (first and third quartiles, 555.2 and 2281.0), with an increase of 179.8% (125% and 376.0%) (p < 0.001); the SKNA-Chest increased from 538.2 µV (first and third quartiles, 432.9 and 663.9) to 640.0 µV (first and third quartiles, 474.2 and 925.6), with an increase of 108.3% (95.6% and 167.9%) (p = 0.004), respectively. In those without recurrence, there was a significant increase in SKNA 1 day after ablation as compared with those before ablation. Twelve patients received SKNA measurement 3 months after ablation; both SKNA-Arm (p = 0.31) and SKNA-Chest (p = 0.27) were similar to those before ablation, respectively. Among patients with symptomatic drug-refractory paroxysmal AF receiving PVI, increased SKNA was observed 1 day after ablation and returned to the baseline 3 months after ablation. Elevation of SKNA was associated with lower early and late recurrences following ablation.

13.
Acute Crit Care ; 37(3): 276-285, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35791662

RESUMO

BACKGROUND: Fiberoptic endoscopic evaluation of swallowing (FEES) has been recommended to assess aspiration in stroke. This study aimed to determine the diagnostic and prognostic roles of FEES in the early assessment of aspiration, intensive care unit (ICU) stay and mortality in acute stroke patients. METHODS: Fifty-two patients with acute stroke admitted to the Alexandria Main University Hospital were included. Complete examinations and assessment of aspiration using the 8-point penetration-aspiration scale (PAS) with FEES protocol were performed. RESULTS: The patients were classified into three groups: normal with no or low risk of aspiration (n=15, 27.3%; PAS level 1), low to moderate risk (n=8, 14.5%; PAS level 2-4), and high risk (n=32, 58.2%; PAS ≥5). There was high incidence of aspiration pneumonia, prolonged ICU stay, and mortality in both moderate- and high-risk groups (P=0.001, P<0.001, and P<0.001, respectively). The PAS score predicted aspiration pneumonia (hospital-acquired pneumonia) with sensitivity and specificity of 80.0% and 76.0%, respectively (negative predictive value [NPV], 76.0; positive predictive value [PPV], 80.0; 95% confidence interval [CI], 0.706-0.940) and mortality with sensitivity and specificity of 88.46% and 68.97% (NPV, 87.0; PPV, 71.9; 95% CI, 0.749-0.951). The PAS score could predict the length of ICU stay with sensitivity and specificity of 70.21% and 87.50, respectively (NPV, 33.3; PPV, 97.1; 95% CI, 0.605-0.906). CONCLUSIONS: The standard FEES protocol using PAS score is a useful tool to assess aspiration in acute stroke patients and could be used to predict length of ICU stay and mortality.

14.
Materials (Basel) ; 15(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35160735

RESUMO

In the present work, bismuth borate glass samples with the composition of (99-x) B2O3 + 1Cr2O3 + (x) Bi2O3 (x = 0, 5, 10, 15, 20, and 25 wt %) were prepared using the melt quenching technique. The mass attenuation coefficient (MAC) of the prepared glass samples was measured through a narrow beam technique using a NaI(Tl) scintillation detector. Four point sources were used (241Am, 133Ba, 152Eu, and 137Cs) to measure the MAC for the prepared glasses. The experimental data were compared with the theoretical results obtained from the XCOM, and it was shown that for all samples at all tested energies, the relative deviation between the samples is less than 3%. This finding signifies that the experimental data can adequately be used to evaluate the shielding ability of the glasses. The MAC of the sample with x = 25 wt % was compared with different lead borate glasses and the results indicated that the present sample has high attenuation which is very close to commercial lead borate glasses. We determined the transmission factor (TF), and found that it is small at low energies and increases as the energy increases. The addition of Bi2O3 leads to reduction in the TF values, which improves the shielding performance of the glass system. The half value layer (HVL) of the BCrBi-10 sample was 0.400 cm at 0.595 MeV, 1.619 cm at 0.2447 MeV, and 4.946 cm at 1.4080 MeV. Meanwhile, the HVL of the BCrBi-20 sample is equal to 0.171 and 4.334 cm at 0.0595 and 1.4080 MeV, respectively. The HVL data emphasize that higher energy photons tend to penetrate through the glasses with greater ease than lower energy photons. Furthermore, the fast neutron removable cross section (FNRC) was determined for the present samples and compared with lead borate glass and concrete, and the results showed a remarkable superiority of the bismuth borate glass samples.

15.
Polymers (Basel) ; 13(22)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34833351

RESUMO

Zeolitic imidazolate frameworks (ZIFs) are interesting materials for use in several aspects: energy storage material, gas sensing, and photocatalysis. The thermal stability and pyrolysis process are crucial in determining the active phase of the material. A deep understanding of the pyrolysis mechanism is in demand. Therefore, the thermodynamics and combustion process with different heating rates was examined, and the kinetic parameters were computed employing thermogravimetric tests. Based on the TG analysis of combustion, pyrolysis moves to the high-temperature region with an increase in heating rate. The decomposition process can be separated into the dehydration (300-503 K) and the pyrolysis reaction (703-1100 K). Three points of the decomposition process are performed by dynamical analysis owing to shifts of slopes, but the combustion process has only one stage. The Zeolitic imidazolate framework's structure properties were examined using TDDFT-DFT/DMOl3 simulation techniques. Dynamical parameters, for instance, the possible mechanism, the pre-exponential factor, and the apparent activation energy are obtained through comparison using the Kissinger formula. The thermodynamics analysis of the Zn1-xCox-ZIF-8 materials is an effective way to explore the temperature influence on the process of pyrolysis, which can benefit several environment purifications, photocatalyst, and recent applications.

16.
ACS Chem Neurosci ; 11(14): 2094-2103, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32530273

RESUMO

Attention-deficit hyperactivity disorder (ADHD) has been proposed to stem from multiple etiologies, perhaps genetic in nature with biological and psychosocial motivates. Tryptophan hydroxylase 2 (TPH2) and Reelin (RELN) genes may play a key role in triggering ADHD. The purpose of this case-controlled study was to explore the linkage of the genetic variants of TPH2 and RELN genes with ADHD. One hundred Egyptian children with ADHD and 105 age and sex matched controls constituted the study samples. Genotyping was performed for TPH2 (rs11179027; rs1843809) and RELN (rs736707; rs362691) gene polymorphisms using real time PCR assay. The alleles and genotype frequencies of TPH2 and RELN gene polymorphisms were assessed in all study participants. The frequencies of the alleles of TPH2 rs11179027 (OR = 1.75, 95% CI = 1.08-2.85, p = 0.022), TPH2 rs1843809 (OR = 3.67, 95% CI = 1.82-7.43, p = <0.001), and RELN rs736707 (OR = 1.61, 95% CI = 1.03-2.51, p = 0.035) were significantly associated with ADHD, while there was no significant difference between ADHD patients and controls regarding the frequency of RELN rs362691 (OR = 1.34, 95% CI = 0.73-2.48, p = 0.34). The frequencies of CTAG, CTGG, CTAC, CTGC, and GTAC haplotypes were significantly higher in ADHD patients than in controls (p = 0.011, 0.005, 0.015, 0.001, and 0.027, respectively). In conclusion, TPH2 rs11179027, TPH2 rs1843809, and RELN rs736707 gene alleles and haplotypes might be significantly correlated with the genetic susceptibility to ADHD in Egyptian children.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno do Deficit de Atenção com Hiperatividade/genética , Criança , Egito , Genótipo , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único/genética , Proteína Reelina , Triptofano Hidroxilase/genética
17.
Bioresour Technol ; 309: 123298, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32289655

RESUMO

This study provides a novel method for improving the anaerobic digestion (AD) of Holstein dairy manure (HDM) by the direct addition of Mineraso (MnS), a natural soil-derived supplement, to the feed of Holstein dairy cattle (HDC). MnS is chiefly composed of approximately 69.08% Fe3O4 and was supplemented at rates of 0 (F1), 25 (F2), and 50 (F3) g/head of HDC/d for two months. The HDM was then examined for non-absorbed iron prior to the batch and semi-continuous bench AD experiments. The results revealed that MnS enhanced CH4 generation in F2 and F3 by 25% and 42%, respectively, in the batch experiments compared to that of F1. Additionally, the gas yield improved in F2 and F3 by 45% and 66%, respectively, over the control after 7 d in the bench experiments. Therefore, supplementing animals with MnS represents a sustainable and economic approach to enhancing CH4 yields.


Assuntos
Biocombustíveis , Esterco , Anaerobiose , Animais , Reatores Biológicos , Bovinos , Ferro , Metano , Solo
18.
Waste Manag ; 101: 141-149, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610475

RESUMO

Improving the quality and quantity of biogas usually requires pre-treatment to maximize methane yields and/or post-treatment to remove H2S, which involves considerable energy consumption and higher costs. Therefore, this study proposes a cost-effective method for the enhanced anaerobic digestion (AD) of dairy manure (DM) without pre/post-treatment by directly adding waste iron powder (WIP) and iron oxide nanoparticles (INPs) to batch digesters. The results showed that the addition of iron in the form of microscale WIP (generated from the laser cutting of iron and steel) at concentrations of 100 mg/L, 500 mg/L, and 1000 mg/L improved methane yields by 36.99%, 39.36%, and 56.89%, respectively. In comparison, the equivalent dosages of INPs improved yields by 19.74%, 18.14%, and 21.11%, respectively. Additionally, the highest WIP dose (1000 mg/L) achieved the maximum improvement in the rate of hydrolysis (k), which was 1.25 times higher than in control reactions, and a maximum biomethane production rate (Rmax) of 0.045 L/gVS/d according to kinetic analysis models (i.e., first-order and the Gompertz kinetic models). The rate of H2S production was also significantly reduced (by 45.20%, 58.16%, and 77.24%) using the three WIP concentrations in comparison with INPs (which achieved reductions of 33.59%, 46.30%, and 53.52%, respectively). Therefore, the direct mixing of WIP with cattle manure is proposed as a practical and economical means of addressing complex and high-cost pre- and post-treatments that are otherwise required in the digestion process.


Assuntos
Esterco , Nanopartículas , Anaerobiose , Animais , Biocombustíveis , Reatores Biológicos , Bovinos , Compostos Férricos , Ferro , Cinética , Metano
19.
J Adv Vet Anim Res ; 6(4): 438-444, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31819869

RESUMO

OBJECTIVE: This study was considered to explore the possible impacts of drinking water quality from different sources on the bioavailability of doxycycline. MATERIALS AND METHODS: Sixty-four tap and ground drinking water samples collected from poultry farms were scrutinized for their water quality limits (TH, pH, total dissolved solids, electrical conductivity, Cl-, Ca+2, Na+, and Mg+2) and heavy metals concentrations (Zn, Fe, Cu, and Ni). An in vitro study was conducted by adding the therapeutic concentrations of doxycycline to all tested water samples, and allowed to interact for 1 h, 3 h, 5 h, and 8 h followed by re-estimation of doxycycline concentrations after each contact time using thin layer chromatography. RESULTS: The therapeutic concentration of doxycycline was decreased in tap water samples by 1.92%, 9.63%, 22.42%, and 30.83% for the aforementioned contact times, respectively, while the corresponding reduction percentages in ground water samples were 2.14%, 17.14%, 28.57%, and 40.09%. However, the control samples had never showed any recorded decrease in their doxycycline concentrations overall contact times. All measured concentrations of doxycycline were significantly lower in tap and ground water than those of control at all times of contact. Both pH, Mg+2 showed significant positive correlations with decreasing values of doxycycline in water. CONCLUSION: Different drinking water sources reduce the concentrations of doxycycline in vitro in a time dependent manner, which can be attributed to their different physico-chemical parameters, i.e., pH and Mg+2 ions. This emphasizes the role of water quality on the stability of antibiotics concentrations administrated via drinking water.

20.
Heart Surg Forum ; 22(5): E331-E339, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31596707

RESUMO

BACKGROUND: Although the use of transcatheter aortic valve replacement (TAVR) has recently become an attractive strategy in prohibitive surgical high-risk patients undergoing aortic valve replacement (AVR), the most appropriate treatment option in patients with an intermediate- to high-risk profile- whether conventional surgery (SAVR) or TAVR-has been widely debated. METHODS: One hundred and forty-three consecutive patients with intermediate to high risk were prospectively enrolled and selected to undergo SAVR (Group 1 [G1], n = 63) or TAVR (Group 2 [G2], n = 80) following a multidisciplinary evaluation including frailty, anatomy, and degree of atherosclerotic disease of the aorta/peripheral vessels. The mean logistic EuroSCORE (G1 = 20.11 ± 7.144 versus G2 = 23.33 ± 8.97; P = .022), STS score (G1 = 5.722 ± 1.309 versus G2 = 5.958 ± 1.689; P = .347), and preoperative demographics such as sex, left ventricular ejection fraction (LVEF),  body mass index (BMI), peripheral vascular disease, diabetes, atrial fibrillation, renal impairment and syncope were similar. Of note, chronic obstructive pulmonary disease was more frequent in TAVR patients (G2 [46.2%] versus G1 [19.0%]; P = .001), whereas pulmonary hypertension was more frequent in SAVR group (G1 [47.6%] versus G2 [17.5%]; P = .000). The SAVR was performed with either a mechanical or tissue valve; meanwhile, TAVR was performed with either Core valve prosthesis or Edwards-Sapiens XT valve. RESULTS: SAVR group showed higher incidence of some postoperative complications compared to TAVR, namely, postoperative bleeding (4.8% versus 0.0%; P = .048), tamponade (4.8% versus 0.0%; P = .048) and postoperative atrial fibrillation (34.9% versus 10.0%; P = .000), whereas TAVR group had a higher incidence of other sets of postoperative complications, namely, left bundle branch block (58.8% versus 4.8%; P = .000), need for permanent pacemaker implantation (25.0% versus 1.6%; P = .000) and peripheral vascular complications (15.0% versus 0.0%; P = .001). On the contrary, when the two groups were compared they did not show any significant difference regarding anemia requiring more than two units of blood transfusion, postoperative renal failure, stroke, myocardial infarction, and hospital mortality. P = .534, .873, .258, .373 and .072 respectively. Hospital mortality was similar among the two groups (G1 = 0% versus G2 = 5%; P = .072). At the 24-month follow-up, overall mortality, major adverse cardiac and cerebrovascular events were comparable between the two groups but prosthetic regurgitation was better in SAVR group (G2 = 8 patients [10.0%] versus G1 = 1 patient [1.6%] in SAVR group; P = .040). CONCLUSION: In this study, we could not detect an advantage in survival when SAVR or TAVR were utilized in intermediate to high surgical risk patients needing aortic valve replacement for severe aortic stenosis.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Complicações Pós-Operatórias/etiologia , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/etiologia , Bloqueio de Ramo/etiologia , Tamponamento Cardíaco/etiologia , Feminino , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/mortalidade , Mortalidade Hospitalar , Humanos , Hipertensão Pulmonar/complicações , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Hemorragia Pós-Operatória/etiologia , Desenho de Prótese , Doença Pulmonar Obstrutiva Crônica/complicações , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodos , Substituição da Valva Aórtica Transcateter/mortalidade , Resultado do Tratamento
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