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1.
Cureus ; 15(1): e33883, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36819412

RESUMEN

Arrhythmogenic right ventricular dysplasia (ARVD) is a genetically predisposed form of cardiomyopathy that mainly affects young individuals resulting in fatal ventricular arrhythmias leading to sudden cardiac death. ARVD has 50% of cases that involve both the right ventricle (RV) and left ventricle (LV), but only a small number of cases involve an isolated left ventricle. In this case series, five patients (four males and one female) with a diagnosis of ARVD presented to our center with varied clinical presentations across a wide range of age groups. The MRI of all five cases showed dilated right atrium (RA)/RV with right ventricular free wall dyskinesia. Two-dimensional (2D) MRI showed aneurysmal outpouching with diffuse free wall enhancement. Automated implantable cardioverter defibrillator (AICD) was implanted uneventfully in all five patients, and the patients were discharged with oral medications such as low-dose diuretics, beta-blockers, spironolactone, angiotensin-converting enzymes (ACE) inhibitors, amiodarone, and anxiolytics. Until now, the patients were doing well on follow-up visits. The therapeutic management of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) has evolved over the years and continues to be an important challenge. To further improve risk stratification and treatment of patients, more information is needed on natural history, long-term prognosis, and risk assessment. Special attention should be focused on the identification of patients who would benefit from implantable cardioverter-defibrillator (ICD) implantation in comparison to pharmacological and other nonpharmacological approaches.

2.
Adv Opt Mater ; 10(16)2022 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-36275124

RESUMEN

Enhanced electromagnetic fields within plasmonic nanocavity mode volumes enable multiple significant effects that lead to applications in both the linear and nonlinear optical regimes. In this work, we demonstrate enhanced second harmonic generation from individual plasmonic nanopatch antennas which are formed by separating silver nanocubes from a smooth gold film using a sub-10 nm zinc oxide spacer layer. When the nanopatch antennas are excited at their fundamental plasmon frequency, a 104-fold increase in the intensity of the second harmonic generation wave is observed. Moreover, by integrating quantum emitters that have an absorption energy at the fundamental frequency, a second order nonlinear exciton - polariton strong coupling response is observed with a Rabi splitting energy of 19 meV. The nonlinear frequency conversion using nanopatch antennas thus provides an excellent platform for nonlinear control of the light-matter interactions in both weak and strong coupling regimes which will have a great potential for applications in optical engineering and information processing.

3.
Adv Mater ; 34(17): e2109673, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35246891

RESUMEN

With the surge in perovskite research, practical features for future applications are desired to be secured, but the reliability of the materials and the use of hazardous Pb are longstanding problems. Here, an air-stable Cs2 SnI6 (CSI) is prepared via diluted hydriodic acid solvent-based precursor optimization during scalable hydrothermal growth. Materials characterization is performed using various elemental peak analyses and crystallographic identification. The resulting CSI exhibits long-term operating stability over 6 months, i) at elevated temperatures, ii) in ambient air, and iii) under light illumination from UV to near-infrared. More importantly, to demonstrate an intriguing class of applications up to system level, physically detachable CSI photodetector arrays (PD-arrays), integrated with micro-light-emitting-diodes (µ-LEDs) arrays, are successfully fabricated. In addition, 3 × 3 flexible CSI PDs are fully operational, even in air, and their spatial uniformity in pixels is quantitatively evaluated. The charge-transport mechanisms of the CSI PDs under light and elevated temperature are assessed via temperature-dependent characterization from 148 to 373 K, implying the involvement of 3D variable-range hopping. Multicycle evaluation of the CSI PD-arrays confirms their operational stability in AC and DC modes, demonstrating this platform's potential benefit for wireless optical interconnection in advanced Si technology.

4.
Nanoscale ; 13(47): 19903-19914, 2021 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-34806742

RESUMEN

Spontaneous parametric down-conversion (SPDC) is one of the most versatile nonlinear optical techniques for the generation of entangled and correlated single-photon pairs. However, it suffers from very poor efficiency leading to extremely weak photon generation rates. Here we propose a plasmonic metasurface design based on silver nanostripes combined with a bulk lithium niobate (LiNbO3) crystal to realize a new scalable, ultrathin, and efficient SPDC source. By coinciding fundamental and higher order resonances of the metasurface with the generated signal and idler frequencies, respectively, the electric field in the nonlinear media is significantly boosted. This leads to a substantial enhancement in the SPDC process which, subsequently, by using the quantum-classical correspondence principle, translates to very high photon-pair generation rates. The emitted radiation is highly directional and perpendicular to the metasurface in contrast to relevant dielectric structures. The incorporation of circular polarized excitation further increases the photon-pair generation efficiency. The presented work will lead to the design of new efficient ultrathin SPDC single-photon nanophotonic sources working at room temperature that are expected to be critical components in free-space quantum optical communications. In a more general context, our findings can have various applications in the emerging field of quantum plasmonics.

6.
Environ Sci Pollut Res Int ; 28(17): 22077-22090, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33415622

RESUMEN

Double slope solar stills are reported to give lower yields in winter season. In this work an attempt has been made to improve the performance of still with double slope in winter. A comparative experimental and theoretical analysis of conventional and modified single basin still with double slope augmented with black dye, pebbles and iron chips (5 kg each) is reported in this manuscript. The experiments are carried out in the month of November and December in 2017 at meteorological conditions of Jaypee University of Engineering and Technology, Guna (Latitude: 24°39'N, Longitude: 77°19'E). Distillate yield in a modified solar still due to the augmentation has improved by 28.4% as compared with conventional solar still at a common water depth of 0.025 m, whereas its overall heat transfer coefficient and overall thermal efficiency are improved by 55.7 and 25.01%, respectively.


Asunto(s)
Purificación del Agua , Calor , Metales , Luz Solar , Agua
7.
Data Brief ; 32: 106272, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32984466

RESUMEN

Herein, the material structural properties such as phase, morphology, chemical composition, and surface area for In2S3 nanoflakes, synthesized by a one-step solvothermal method, are studied [1]. The comparative electrochemical performance data of indium based electrode material is presented to establish the practical suitability of prepared In2S3 electrode material. Device demonstration of fabricated solid-state supercapacitor device on different time frames set performance level demonstration of current work and suggest a potential candidate for next-generation energy storage electrode material.

8.
Environ Sci Technol ; 42(24): 9344-9, 2008 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19174914

RESUMEN

This research investigated reduction of trichloroethylene (TCE) at boron-doped diamond (BDD) film cathodes using a rotating disk electrode reactor. Rates of TCE reduction were determined as functions of the electrode potential and TCE concentration over a temperature range between 2 and 32 degrees C. Reduction of TCE resulted in production of acetate and chloride ions with no detectable intermediate products. At a current density of 15 mA/cm2 and concentrations below 0.75 mM, reaction rates were first order with respect to TCE concentration, with surface area normalized rate constants 2 orders of magnitude greater than those for iron electrodes. Density functional theory (DFT) simulations were used to evaluate activation barriers for reduction by direct electron transfer, and for reaction with four functional groups commonly found on BDD surfaces. The DFT calculated activation barrier for direct electron transfer was more than 4 times greater than the experimentally measured value of 22 kJ/mol. In contrast, the DFT activation barrier for reaction at a deprotonated hydroxyl site on a tertiary carbon atom (triple bond C-O(-)) of 24 kJ/mol was in close agreement with the experimental value. Both experiments and quantum mechanical simulations support a TCE reduction mechanism that involves chemically adsorbed intermediates.


Asunto(s)
Boro/química , Diamante/química , Halogenación , Tricloroetileno/química , Electrodos , Modelos Químicos , Oxidación-Reducción , Rotación , Termodinámica
9.
Environ Sci Technol ; 39(2): 645-50, 2005 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-15707067

RESUMEN

This study investigated the reaction mechanisms of nitrate (NO3-) with zerovalent iron (ZVI) media under conditions relevantto groundwatertreatment using permeable reactive barriers (PRB). Reaction rates of NO3- with freely corroding and with cathodically or anodically polarized iron wires were measured in batch reactors. Tafel analysis and electrochemical impedance spectroscopy (EIS) were used to investigate the reactions occurring on the iron surfaces. Reduction of NO3- by corroding iron resulted in near stoichiometric production of NO2-, which did not measurably react in the absence of added Fe(II). Increasing NO3- concentrations resulted in increasing corrosion currents. However, EIS and Tafel analyses indicated that there was little direct reduction of NO3- at the ZVI surface, despite the presence of water reduction. This behavior can be attributed to formation of a microporous oxide on the iron surfaces that blocked reduction of NO3- and NO2- but did not block water reduction. This finding is consistent with previous observations that NO3- impedes reduction of organic compounds by ZVI. Nitrite concentrations greater than 4 mM resulted in anodic passivation of the iron, but passivation was not observed with NO3- concentrations as high as 96 mM. This indicates that the passivating oxide preventing NO3- reduction was permeable toward cation migration. Since reaction with Fe(0) can be excluded asthe mechanism for NO3- and NO2- reduction, reaction with Fe(II)-containing oxides coating the iron surface is the most likely reaction mechanism. This suggests that short-term batch tests requiring little turnover of reactive sites on the iron surface may overestimate long-term rates of NO3- removal because the effects of passivation are not apparent in batch tests conducted with high initial Fe(II) to NO3- ratios.


Asunto(s)
Hierro/química , Nitratos/química , Contaminantes del Suelo/análisis , Contaminantes del Agua/análisis , Electroquímica , Permeabilidad , Análisis Espectral
10.
Environ Sci Technol ; 39(24): 9689-94, 2005 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-16475353

RESUMEN

The objective of this research was to determine if Fe(II)-bearing iron oxides generate ferric hydroxides at sufficient rates for removing low levels of arsenic in packed-bed reactors, while at the same time avoiding excessive oxide production that contributes to bed clogging in oxygenated waters. Column experiments were performed to determine the effectiveness of three media for arsenic removal over a range in empty bed contact times, influent arsenic concentrations, dissolved oxygen (DO) levels, and solution pH values. Corrosion rates of the media as a function of the water composition were determined using batch and electrochemical methods. Rates of arsenic removal were first order in the As(V) concentration and were greater for media with higher corrosion rates. As(V) removal increased with increasing DO levels primarily due to faster oxidation of the Fe2+ released by media corrosion. To obtain measurable amounts of arsenic removal in 15 mM NaCl electrolyte solutions containing 50 microg/L As(V), the rate of Fe2+ released by the media needed to be at least 15 times greater than the As(V) feed rate into the column. In waters containing 30 mg/L of silica and 50 microg/L of As(V), measurable amounts of arsenic removal were obtained only for Fe2+ release rates that were at least 200 times greater than the As(V) feed rate. Although all columns showed losses in hydraulic conductivity overthe course of 90 days of operation, the conductivity values remained high, and the losses could be reversed by backwashing the media. The reaction products produced by the media in domestic tap water had average As-to-Fe ratios that were approximately 25% higher than those for a commercially available adsorbent.


Asunto(s)
Arsénico/aislamiento & purificación , Compuestos Férricos/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Adsorción , Corrosión , Electroquímica , Electrólitos/química , Concentración de Iones de Hidrógeno , Cinética , Oxígeno/química , Dióxido de Silicio/química , Cloruro de Sodio/química
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