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1.
Exp Mol Pathol ; 127: 104803, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35679887

RESUMEN

INTRODUCTION: Although wound refers to simple cut in the skin, most wounds don't heal because of the various local and systemic factors that lead to its complexity and chronicity. Thus, prior understanding of the status of the wound is necessary and methods that can differentiate between the healing and non-healing wounds at a much earlier stage is crucial for a successful treatment. METHODS: The current study aims at differentiating Acute Wound Fibroblasts (AWFs) and Chronic Wound Fibroblasts (CWFs) based on differential expression of fibroblast specific markers such as Vimentin and Alpha Smooth Muscle Actin (α-SMA) and compare its cell cycle and proliferation. RESULTS: Immunostaining and western blotting analysis showed that, AWFs and CWFs differentially expressed vimentin and α-SMA, with AWFs and CWFs showing higher expression of vimentin and α-SMA respectively. AWFs showed higher distributions in G0/G1 (67.43% vs. 62.16%), S phase (22.61% vs. 8.51%) compared to CWFs. However, AWFs showed decreased distributions compared to CWFs in G2 + M phase (8.14% vs. 10.6%). Thus, it was observed that CWFs showed cell cycle arrest in the G1/G0 phase and inhibited DNA synthesis, which was further confirmed by reduced proliferation of CWFs. We suggest that, differential expression of the cell specific markers can be attributed to its pathophysiological status and chronicity of the wound and reduced proliferation rate of CWFs is due to lesser expression of vimentin, which is a key protein for in vitro cell proliferation. CONCLUSIONS: Outcome of the study serve as an immunological tool to guide the chronicity of the wound, which helps to understand the wound towards design of personalized care. The findings also represent a promising opportunity to gain insight into how cell cycle arrest can impact on wound healing and clinical outcomes.


Asunto(s)
Fibroblastos , Cicatrización de Heridas , Actinas/genética , Actinas/metabolismo , Puntos de Control del Ciclo Celular/genética , Proliferación Celular , Fibroblastos/metabolismo , Humanos , Vimentina/genética , Vimentina/metabolismo
2.
J Pediatr ; 229: 33-40, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33075369

RESUMEN

OBJECTIVE: To describe the similarities and differences in the evaluation and treatment of multisystem inflammatory syndrome in children (MIS-C) at hospitals in the US. STUDY DESIGN: We conducted a cross-sectional survey from June 16 to July 16, 2020, of US children's hospitals regarding protocols for management of patients with MIS-C. Elements included characteristics of the hospital, clinical definition of MIS-C, evaluation, treatment, and follow-up. We summarized key findings and compared results from centers in which >5 patients had been treated vs those in which ≤5 patients had been treated. RESULTS: In all, 40 centers of varying size and experience with MIS-C participated in this protocol survey. Overall, 21 of 40 centers required only 1 day of fever for MIS-C to be considered. In the evaluation of patients, there was often a tiered approach. Intravenous immunoglobulin was the most widely recommended medication to treat MIS-C (98% of centers). Corticosteroids were listed in 93% of protocols primarily for moderate or severe cases. Aspirin was commonly recommended for mild cases, whereas heparin or low molecular weight heparin were to be used primarily in severe cases. In severe cases, anakinra and vasopressors frequently were recommended; 39 of 40 centers recommended follow-up with cardiology. There were similar findings between centers in which >5 patients vs ≤5 patients had been managed. Supplemental materials containing hospital protocols are provided. CONCLUSIONS: There are many similarities yet key differences between hospital protocols for MIS-C. These findings can help healthcare providers learn from others regarding options for managing MIS-C.


Asunto(s)
COVID-19/terapia , Protocolos Clínicos , Pautas de la Práctica en Medicina/estadística & datos numéricos , Síndrome de Respuesta Inflamatoria Sistémica/terapia , Antiinflamatorios no Esteroideos/uso terapéutico , Anticoagulantes/uso terapéutico , Antirreumáticos/uso terapéutico , Aspirina/uso terapéutico , COVID-19/diagnóstico , Niño , Estudios Transversales , Glucocorticoides/uso terapéutico , Heparina/uso terapéutico , Hospitales , Humanos , Inmunoglobulinas Intravenosas , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Encuestas y Cuestionarios , Síndrome de Respuesta Inflamatoria Sistémica/diagnóstico , Estados Unidos/epidemiología , Vasoconstrictores/uso terapéutico
3.
Pediatr Cardiol ; 41(6): 1206-1211, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32488510

RESUMEN

Non-invasive evaluation of right ventricular (RV) systolic function in neonates with pulmonary hypertension (PH) with traditional metrics including RV fractional area change (FAC) and tricuspid annular systolic plane excursion (TAPSE) has improved outcomes. Apical three-chamber (3C) RV-FAC, a novel tripartite assessment of the RV, has recently been described in healthy infants. We assess the utility of 3C RV-FAC and biplane RV-FAC in delayed transitioning and neonatal PH. Echocardiograms for 22 normal infants and 22 infants with PH were retrospectively analyzed for RV systolic function indices including four chamber (4C), 3C, and biplane RV-FAC, TAPSE, Tei index, and RV systolic excursion velocity (S'). 4C, 3C, and biplane RV-FAC correlated with PH severity and was decreased in neonates with PH compared to normal neonates (biplane RV-FAC 31.7 ± 13.4% vs. 41 .9 ± 4.7%, p = 0.002). TAPSE was significantly decreased in neonates with PH, but did not correlate with PH severity. Other RV systolic function metrics were not significantly different between normal neonates and neonates with PH. 3C RV-FAC and biplane RV-FAC are lower in neonates with PH. 3C and biplane RV-FAC may allow for improved assessment of global RV systolic dysfunction in newborns with delayed transitioning or PH compared to the commonly used regional methods.


Asunto(s)
Hipertensión Pulmonar/fisiopatología , Disfunción Ventricular Derecha/diagnóstico por imagen , Función Ventricular Derecha , Ecocardiografía/métodos , Femenino , Humanos , Hipertensión Pulmonar/diagnóstico por imagen , Recién Nacido , Masculino , Estudios Retrospectivos , Sístole , Válvula Tricúspide/diagnóstico por imagen , Válvula Tricúspide/fisiopatología , Disfunción Ventricular Derecha/fisiopatología
4.
Arch Environ Contam Toxicol ; 79(1): 111-121, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32274556

RESUMEN

Microplastics (< 5 mm) are considered to be global environmental pollutants. This study investigates the occurrence, physical properties, polymer composition and surface morphology, and element composition of MPs present in food-grade salts produced from seawater and bore-well water in Tuticorin, Tamil Nadu, Southeast coast of India. Fourteen different brands of sea salts and bore-well salts were collected from the salt manufacturing units. The mean abundance of microplastics was 35 ± 15 to 72 ± 40 items/kg in sea salt and 2 ± 1 to 29 ± 11 items/kg in bore-well salt. Four types of polymers viz. polyethylene (51.6%), polypropylene (25%), polyester (21.8%), and polyamide (1.6%) were found in salt. Polyethylene fibers of size ranging from 100 to 500 µm were observed commonly. Being manufactured from seawater, sea salt had the highest quantities of different microplastic particles. The study reveals that people consume approximately 216 particles of MPs per year via sea salt and 48 items per year via bore-well salt if the average person has a daily salt intake of 5 g. The surface morphology of MPs as exhibited in the SEM-EDAX images obtained in the study revealed the different weathering features of MPs, such as pits, cracks, and particles adhering to the surface. The presence of the elements Fe, As, and Ni on the surfaces as identified by energy-dispersive x-ray spectroscopy indicates that these elements exist in the environment as contaminants and have become associated with the MPs. The trace metals adsorbed onto MPs increase the risks of human exposure and may cause some adverse effects in humans.


Asunto(s)
Monitoreo del Ambiente/métodos , Microplásticos/análisis , Agua de Mar/química , Cloruro de Sodio Dietético/análisis , Contaminantes Químicos del Agua/análisis , India , Polietileno/análisis , Polipropilenos/análisis , Propiedades de Superficie
5.
J Environ Manage ; 248: 109246, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31323456

RESUMEN

Nano-size photocatalysts exhibit multifunctional properties that opened the door for improved efficiency in energy, environment, and health care applications. Among the diversity of catalyst Quantum dots are a class of nanomaterials having a particle size between 2 and 10 nm, showing unique optoelectrical properties that are limited to some of the metal, metal oxide, metal chalcogenides, and carbon-based nanostructures. These unique characteristics arise from either pristine or binary/ternary composites where noble metal/metal oxide/metal chalcogenide/carbon quantum dots are anchored on the surface of semiconductor photocatalyst. It emphasized that properties, as well as performance of photocatalytic materials, are greatly influenced by the choice of synthesis methods and experimental conditions. Among the chemical methods, photo-deposition, precipitation, and chemical reduction, are the three most influential synthesis approaches. Further, two types of quantum dots namely metal based and carbon-based materials have been highlighted. Based on the optical, electrical and surface properties, quantum dots based photocatalysts have been divided into three categories namely (a) photocatalyst (b) co-catalyst and (c) photo-sensitizer. They showed enhanced photocatalytic performance for hydrogen production under visible/UV-visible light irradiation. Often, pristine metal chalcogenides as well as metal/metal oxide/carbon quantum dots attached to a semiconductor particle exhibit enhanced the photocatalytic activity for hydrogen production through absorption of visible light. Alternatively, noble metal quantum dots, which provide plenty of defects/active sites facilitate continuous hydrogen production. For instance, production of hydrogen in the presence of sacrificial agents using metal chalcogenides, metal oxides, and coinage metals based catalysts such as CdS/MoS2 (99,000 µmol h-1g-1) TiO2-Ni(OH)2 (47,195 µmol h-1g-1) and Cu/Ag-TiO2 nanotubes (56,167 µmol h-1g-1) have been reported. Among the carbon-based nanostructures, graphitic C3N4 and carbon quantum dots composites displayed enhanced hydrogen gas (116.1 µmol h-1) production via overall water splitting. This review accounts recent findings on various chemical approaches used for quantum dots synthesis and their improved materials properties leading to enhanced hydrogen production particularly under visible light irradiation. Finally, the avenue to improve quantum efficiency further is proposed.


Asunto(s)
Grafito , Puntos Cuánticos , Catálisis , Hidrógeno , Semiconductores
6.
J Nanosci Nanotechnol ; 17(2): 1267-274, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29683301

RESUMEN

Hetero atoms containing conductive nanocarbon materials are being studied extensively for their electrochemical energy storage and conversion applications. Herein, we report a facile process for the preparation of N-containing carbon/graphene nanocomposites by simultaneous thermal decomposition of polypyrrole into N-containing carbon and reduction of graphene oxide into graphene in H2/Ar atmosphere. The XRD pattern of N-containing carbon/graphene nanocomposites prepared at different temperatures indicated the formation of reduced graphene oxide from the reduction of GO. The FT-IR and Raman spectroscopic analysis revealed the presence of N atoms in the nanocomposites and the elemental analysis was used to estimate the amount of N in the nanocomposite. The XPS analysis distinguished the pyridine, pyrrolic and quaternary forms of N present in the nanocomposite. The slow decomposition of polypyrrole resulted in the mesoporous structure to the resulting nanocomposite, which was confirmed by the BET adsorption­desorption isotherm. The electron microscopic analysis confirmed the presence of highly transparent carbon nanosheets. The amount of N in the nanocomposite that depends on the decomposition temperature was found to influence the electrochemical performance. The nanocomposite prepared at 700 °C showed a large specific capacitance of 296 F/g with an excellent cycling stability of 93% after 1000 cycles.

7.
Phys Chem Chem Phys ; 16(10): 4952-61, 2014 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-24477791

RESUMEN

Mn3O4-reduced graphene oxide (RGO) nanocomposites were prepared by chemical decomposition of the manganese hexacyanoferrate (MnHCF) complex directly on the graphene surface. XRD studies revealed the formation of crystalline hausmannite Mn3O4 nanocubes in the as-prepared nanocomposites without any heat treatment. The FE-SEM images showed the formation of Mn3O4 nanocubes on the graphene surface in the as-prepared nanocomposites. HR-TEM studies confirmed the homogeneous dispersion of ∼25 nm Mn3O4 nanocubes on graphene nanosheets. The amount of Mn3O4 nanocubes and graphene in the nanocomposites was estimated using TGA analysis from room temperature to 800 °C in air. The FT-IR and Raman spectroscopic analysis confirmed the functional groups in the nanocomposites and defects in graphene nanosheets in the nanocomposites. Cyclic voltammetry and galvanostatic charge-discharge experiments demonstrated a high specific capacitance of 131 F g(-1) in 1 M Na2SO4 electrolyte at a current density of 0.5 A g(-1) for the RGM-0.5 nanocomposite. A capacitance retention of 99% was observed for 500 charge-discharge cycles at a current density of 5 A g(-1), which conformed the excellent stability of the RGM electrodes. The prepared Mn3O4-RGO nanocomposites are promising for electrochemical energy storage.

8.
Sci Total Environ ; 894: 164904, 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37343861

RESUMEN

Microplastics (MPs) and the pollutants associated with them pose a significant risk to the aquatic ecosystems. This study analysed the spatial and seasonal differences in MPs in terms of diversity, inventory and associated heavy metals, and assessed the risk carried by MPs in different functional areas of Tuticorin, southeast coast of India. The mean MPs abundance varies from 5.67 ± 3.1 to 94.66 ± 6.5 items/L in water and 6 ± 1.73 to 147 ± 18.6 items/kg in sediment. More MPs are found in monsoon water and post-monsoon sediment. Fibre-shaped polyethylene (PE) and polypropylene (PP) MPs have a dominant presence in all seasons. They might derive from synthetic clothing, derelict fishing gear and improper dumping of plastic waste in this region. The carbonyl index (CI) of PE varies from 0.01 to 1.2 and that of PP from 0.03 to 0.98. The high surface oxidation rate (with CI ≥ 0.31) indicates the weathering level of MPs. The high microplastics diversity index (MPDII) of the Fishing Harbour points to the diverse pollution sources. The inventory of MPs is expressed in terms of their weight-based accumulation. Higher inventory of MPs is detected in the water (0.018 ton/km2) and sediment (2.03 ton/km2) of Fishing Harbour. The scanning electron microscope (SEM) images of MPs reveal various surface morphologic features like cracks, protrusion, void space, and adsorbed microorganisms. Energy dispersive X-ray spectroscopy (EDAX) shows the presence of metals (Mn, Cu, Zn, Ni, K, Ca, Cr, Mg, Ti, Cd, As, Se, Fe, Al, and Si) on the MPs surfaces. The polymer hazard index (PHI) indicates a III to IV chemical risk level. All the information obtained from the analysis presents a clear image of the nature and distribution of MPs in this region.

9.
Chemosphere ; 311(Pt 2): 137030, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36334741

RESUMEN

Ternary nanohybrids based on mesoporous graphitic carbon nitride (g-C3N4) were synthesized and presented for developing stable and efficient Hydrogen (H2) production system. Based on photocatalytic activity, optimization was performed in three different stages to develop carbon nanotubes (CNTs) and WO3 loaded g-C3N4 (CWG-3). Initially, the effect of exfoliation was investigated, and a maximum specific surface area of 100.77 m2/g was achieved. 2D-2D interface between WO3 and g-C3N4 was targeted and achieved, to construct a highly efficient direct Z-scheme heterojunction. Optimized binary composite holds the enhanced activity of about 2.6 folds of H2 generation rates than the thermally exfoliated g-C3N4. Further, CNT loading towards binary composite in an optimized weight ratio enhances the activity by 6.86 folds than the pristine g-C3N4. Notably, optimized ternary nanohybrid generates 15,918 µmol h-1. g-1cat of molecular H2, under natural solar light irradiation with 5 vol% TEOA as a sacrificial agent. Constructive enhancements deliver remarkable H2 production and dye degradation activities. Results evident that, the same system can be useful for pilot-scale energy generation and other photocatalytic applications as well.

10.
J Colloid Interface Sci ; 605: 871-880, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34371430

RESUMEN

Owing to the unique electronic properties of layered materials, topological insulators have interestingly grabbed much attention in the field of photocatalytic water splitting. Nowadays, 2D layered materials were composited with semiconductor photocatalysts, encourage much as it provides enormous active sites and also significantly prevent photogenerated charge recombination. Especially, Bi2Se3 possesses exceptional properties like topologically preserved conducting surface states with bulk insulating behavior and high surface area, which provides unconventional electron dynamics, resulting in facile electron transport and effective charge separation to photocatalyst. So far, several methods have been attempted to synthesize few-layered Bi2Se3 nanosheets from its bulk crystals. Here, a unique attempt is made and succeeded to exfoliate bulk Bi2Se3 to few layered nanosheets via surfactant free supercritical fluid processing using N-Methyl-2-pyrrolidone (NMP) as an exfoliating agent, with a short reaction time of 15 min. The exfoliation of Bi2Se3 crystal was confirmed by several characterization techniques, such as XRD, SEM, Raman, and HR-TEM. Furthermore, different weight percentages of exfoliated Bi2Se3 sheets/anatase TiO2 nanoparticles were prepared and examined the photocatalytic activity using glycerol as a hole scavenger. Among them, 15 wt.% Bi2Se3 coupled TiO2 nanocomposite showed enormous hydrogen evolution rate of 84.9 mmol h-1g-1cat, which is 80 times higher than that of TiO2 nanoparticles. In addition, the photostability of the nanocomposite was also verified, where it retains 94% of activity even after 4 cycles of continuous experiments. The improved rate of H2 production was understood by theoretical calculations that topologically preserved conducting surface states of co-catalyst, Bi2Se3 nanosheets is supported to high mobile and scatter free electrons. It mediates the transport of electrons with TiO2 nanoparticles that helped the effective charge separation. Thus, it proves a promising candidate for photocatalytic hydrogen production.

11.
Sci Total Environ ; 820: 153337, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35077792

RESUMEN

This study investigated the spatial and vertical distribution of microplastics (MPs) in the water and sediment samples collected from different locations in Kodaikanal Lake, a very popular tourist location. The lake provides water to placesdownstream. MPs are found in the surface water, surface sediment and core sediment, with their respective values of abundance being 24.42 ± 3.22 items/ l, 28.31 ± 5.29 items/ kg, and 25.91 ± 7.11 items/ kg. Spatially, abundance, colour, type and size of MPs vary in the samples of surface water and sediment. The highest levels of MPs are found in the lakes' outlet region. MPs detected are primarily fibres and fragments 3-5 mm in size with PE and PP being the predominant polymers. Seven sampling points were selected to investigate the vertical distribution of MPs. In the core sediment, the abundance and size of MPs decrease with depth. This probably indicates the presence of more MPs in the recent sediment. The core sediment is dominated by sand silt clay fractions, which facilitates potential downward infiltration of fine MPs. SEM images of MPs reveal that the degree of weathering increases with depth, and EDAX shows that smooth MP surface displays a lesser adhesion ability than the rough surface. Plastic wastes generated by tourism are the important source of MPs in the lake. The lake has high PHI values (>1000) due to MPs with high hazard score polymers (PS and PEU), whereas the PLI values (1.33) indicate low level of MP pollution representing a minor ecological risk. The MP level in Kodaikanal Lake is influenced by the lake's hydrology and the sources of pollution. Although the impacts of MP pollution on the health and functioning of the environment is uncertain, observing, understanding and halting of further MP contamination in the Kodaikanal Lakes is important.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente/métodos , Sedimentos Geológicos , Lagos , Plásticos , Contaminantes Químicos del Agua/análisis
12.
Braz J Biol ; 84: e249472, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35384979

RESUMEN

Leaf rust, caused by Puccinia triticina, is the most common rust disease of wheat. The fungus is an obligate parasite capable of producing infectious urediniospores. To study the genetic structure of the leaf rust population 20 RAPD primers were evaluated on 15 isolates samples collected in Pakistan. A total of 105 RAPD fragments were amplified with an average of 7 fragments per primer. The number of amplified fragments varied from 1 to 12. GL Decamer L-07 and GL Decamer L-01 amplified the highest number of bands (twelve) and primer GL Decamer A-03 amplified the lowest number of bands i.e one. Results showed that almost all investigated isolates were genetically different that confirms high genetic diversity within the leaf rust population. Rust spores can follow the migration pattern in short and long distances to neighbor areas. Results indicated that the greatest variability was revealed by 74.9% of genetic differentiation within leaf rust populations. These results suggested that each population was not completely identical and high gene flow has occurred among the leaf rust population of different areas. The highest differentiation and genetic distance among the Pakistani leaf rust populations were detected between the leaf rust population in NARC isolate (NARC-4) and AARI-11and the highest similarity was observed between NARC isolates (NARC-4) and (NARC-5). The present study showed the leaf rust population in Pakistan is highly dynamic and variable.


Asunto(s)
Basidiomycota , Enfermedades de las Plantas , Basidiomycota/genética , Puccinia , Técnica del ADN Polimorfo Amplificado Aleatorio , Tecnología
13.
J Colloid Interface Sci ; 600: 264-277, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34022723

RESUMEN

The supercapattery, an ideal electrochemical energy storage device, which can deliver high energy like battery and high power like supercapacitor. Transition metal sulphides' energy storage capabilities have unfurled beyond the realm of ruthenium and manganese-based oxides by the versatile affordable sulphospinel transition metal sulphides such as MnCo2S4 (MCS). The advancement of synergistic nano-architectures of these transition metal sulphides with two-dimensional MXene material adulated the conductivity and highly reversible redox nature. The hybrid MCS-MXene was synthesised through facile cost effective hydrothermal method and the material were characterised using basic X-Ray Diffraction (XRD) to advanced tools as like electron energy loss spectroscopy (EELS). The electrochemical results depict that the supercapattery electrode of 2D synergistic MCS-MXene hybrid architectures shows highly improved specific capacitance of 600 C/g at 1 A/g current density than pristine MXene and MCS. The fabricated asymmetric supercapattery using hybrid MCS-MXene and bio-derived activated carbon (AC) shows a high specific energy and power density of 25.6 Wh/kg and 6400 W/kg, respectively with excellent cycling stability of 100% capacitance retention after 12,000 cycles.

14.
J Colloid Interface Sci ; 598: 409-418, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-33930745

RESUMEN

The transition metal ions (TMIs) such as Co2+ and Zn2+ doped NiMn2O4 (NMO)/rGO nanocomposite synthesized by facile sol-gel method was used for the fabrication of supercapacitor. The presence of metal ions in the nanocomposite was confirmed by X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscope (HR-TEM) mapping techniques. The fabricated electrode showed high specific capacitance of 710 F/g which was 3-fold higher than NMO (254 F/g). The addition of RGO in the nanocomposite increased the cycle stability of TMIs doped NMO significantly from 51 to 91%. In addition, the symmetric supercapacitor (SSC) fabricated using TMIs doped NMO/rGO nanocomposite with 3.5 M KOH as an electrolyte delivered a maximum energy density of 43 Wh/kg and power density of 10 kW/kg. Furthermore, the SSC device retained 90% of capacitance retention over 10,000 cycles with coulombic efficiency of 99% at 5 A/g. These result suggested that the TMIs doped NMO/rGO nanocomposite electrode is a promising material for high-energy supercapacitors.

15.
J Colloid Interface Sci ; 584: 204-215, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33069019

RESUMEN

This work demonstrates a high-performance hybrid asymmetric supercapacitor (HASC) workable in very high current density of 30 A g-1 with in-situ pyrolytic processed sulfur-doped graphitic carbon nitride/cobalt disulfide (S-gC3N4/CoS2) materials and bio-derived carbon configuration and achievement of high electrochemical stability of 89% over 100,000 cycles with the coulombic efficiency of 99.6%. In the electrochemical studies, the S-gC3N4/CoS2-II electrode showed a high specific capacity of 180 C g-1 at 1 A g-1 current density in the half-cell configuration. The HASC cell was fabricated using S-gC3N4/CoS2-II material and orange peel derived activated carbon as a positive and negative electrode with a maximum operating cell potential of 1.6 V, respectively. The fabricated HASC delivered a high energy density of 26.7 Wh kg-1 and power density of 19.8 kW kg-1 in aqueous electrolyte. The prominent properties in specific capacity and cycling stability could be attributed to the CoS2 nanoparticles engulfed into the S-gC3N4 framework which provides short transport distance of the ions, strong interfacial interaction, and improving structural stability of the S-gC3N4/CoS2-II materials.

16.
Nanoscale Adv ; 3(7): 2075-2088, 2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-36133087

RESUMEN

Dual direct Z-scheme photocatalysts for overall water decomposition have demonstrated strong redox abilities and the efficient separation of photogenerated electron-hole pairs. Overall water splitting utilizing NiAl-LDH-based binary and ternary nanocomposites has been extensively investigated. The synthesized binary and ternary nanocomposites were characterized via XRD, FTIR, SEM, HRTEM, XPS, UV-DRS, and photoelectrochemical measurements. The surface wettability properties of the prepared nanocomposites were measured via contact angle measurements. The application of the NiAl-LDH/g-C3N4/Ag3PO4 ternary nanocomposite was investigated for photocatalytic overall water splitting under light irradiation. In this work, we found that in the presence of Ag3PO4, the evolution of H2 and O2 is high over LCN30, and 2.8- fold (O2) and 1.4-fold (H2) activity increases can be obtained compared with the use of LCN30 alone. It is proposed that Ag3PO4 is involved in the O2 evolution reaction during water oxidation and g-C3N4 is involved in overall water splitting. Our work not only reports overall water splitting using NiAl-LDH-based nanocomposites but it also provides experimental evidence for understanding the possible reaction process and the mechanism of photocatalytic water splitting. Photoelectrochemical measurements confirmed the better H2 and O2 evolution abilities of NiAl-LDH/g-C3N4/Ag3PO4 in comparison with NiAl LDH, g-C3N4, Ag3PO4, and LCN30. The observed improvement in the gas evolution properties of NiAl LDH in the presence of Ag3PO4 is due to the formation of a dual direct Z-scheme, which allows for the easier and faster separation of charge carriers. More importantly, the LCNAP5 heterostructure shows high levels of H2 and O2 evolution, which are significantly enhanced compared with LCN30 and pure NiAl LDH.

17.
J Colloid Interface Sci ; 590: 82-93, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33524723

RESUMEN

The development of the efficient photocatalysts with improved photoexcited charge separation and transfer is an essential for the effective photocatalytic H2 generation using light energy. So far, owing to the unique properties and characteristics, the transition metal phosphides (TMPs) have been proven to be high performance co-catalysts to replace some of the classic precious metal materials in the photocatalytic water splitting. In the present work, we report a novel copper phosphide (Cu3P) as a co-catalyst to form a well-designed fabricated photocatalyst with blacktrumpet mushroom-like ZnS semiconductor for the first time. The synthesis of Cu3P/ZnS consists of two-step hydrothermal and ball milling methods. The physical properties of the materials so prepared were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analyses. In order to study the role of Cu3P, electrochemical impedance spectroscopy (EIS) measurements were used to investigate the photogenerated charge properties of ZnS. The experiments of photocatalytic production of H2 confirm that the Cu3P co-catalysts effectively promote the separation of photogenerated charge carriers in ZnS, and consequently enhance the H2 evolution activity. The 3% Cu3P/ZnS sample delivers the highest catalyst activity and the consistent H2 evolution rate is14,937 µmol h-1 g-1cat, which is 10-fold boosted compared to the pristine ZnS. The stability of the catalyst was tested by reusing the used 3% Cu3P/ZnS photocatalyst in five consecutive runs, and their respective activity in the H2 production activity was evaluated. A possible mechanism is proposed and discussed.

18.
Mar Pollut Bull ; 165: 112101, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33549998

RESUMEN

We studied the abundance of microplastics from commercial table salts and table salts from salt pans at Marakkanam and Parangipettai, Tamil Nadu, India. Microplastic abundance in the salts collected from salt pans had a range of 3.67 ± 1.54 to 21.33 ± 1.53 nos./10 g of salt which were higher than the microplastics retrieved from the commercial salts which ranged from 4.67 ± 1.15 to 16.33 ± 1.53 nos./10 g of salt. All the microplastics retrieved were fibers which were secondary in origin. Black, red, blue, green, white, brown, and colorless microplastics were observed in the samples. FT-IR results showed that 4 types of polymers, namely, Nylon, Polypropylene (PP), Low Density Polyethylene (LDPE), and Polyethylene Terephthalate (PET) were present in the samples. Domestic and municipal wastewater discharges into the estuaries may contribute to microplastics in the table salts. Our study proves that table salts (processed and unprocessed) are prone to microplastic contamination.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Contaminación de Alimentos/análisis , India , Plásticos , Sales (Química) , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisis
19.
Semin Cardiothorac Vasc Anesth ; 25(3): 208-217, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32450763

RESUMEN

Tetralogy of Fallot (ToF) with pulmonary atresia (ToF-PA) is a complex congenital heart defect at the extreme end of the spectrum of ToF, with no antegrade flow into the pulmonary arteries. Patients differ with regard to the sources of pulmonary blood flow. In the milder spectrum of disease, there are confluent branch pulmonary arteries fed by ductus arteriosus. In more severe cases, however, the ductus arteriosus is absent, and the sole source of pulmonary blood flow is via major aortopulmonary collateral arteries (MAPCAs). The variability in the origin, size, number, and clinical course of these MAPCAs adds to the complexity of these patients. Currently, the goal of management is to establish pulmonary blood flow from the right ventricle (RV) with RV pressures that are ideally less than half of the systemic pressure to allow for closure of the ventricular septal defect. In the long term, patients with ToF-PA are at higher risk for reinterventions to address pulmonary arterial or RV-pulmonary artery conduit stenosis, progressive aortic root dilation and aortic insufficiency, and late mortality than those with less severe forms of ToF.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Atresia Pulmonar , Tetralogía de Fallot , Circulación Colateral , Humanos , Lactante , Atresia Pulmonar/diagnóstico por imagen , Atresia Pulmonar/cirugía , Estudios Retrospectivos , Tetralogía de Fallot/diagnóstico por imagen , Tetralogía de Fallot/cirugía
20.
Environ Pollut ; 266(Pt 1): 115219, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32683232

RESUMEN

Microplastics (MPs) in the marine environment are ubiquitous. The ingestion of these pollutants by marine organisms has drawn global attention. This work studies the distribution pattern and characteristics of MPs found in the body of the clam Donax cuneatus and its environment in order to understand the possible relationship between the MP concentration in the environment (water and sediment) and that in the clam's body. Samples of D. cuneatus were collected from the coast between Vembar and Periyathazhai in Tuticorin district along GoM. MP concentrations range from 0.6 to 1.3 items/g (wet weight) in clams, 10-30 items/l in water, and 24-235 items/kg in sediment. Small-sized clams contain the highest concentration of MPs. Hence it is hypothesised that allometric relationship exists between body size and MP concentration, depending on the surface-area to volume ratio. MP abundance in clam body has a clear, positive, significant correlation with MP abundance in sediment but not with abundance of MP in water. Microplastics of fiber type with size 100-250 µm have a predominant presence in clams. The study identified ten types of polymers, of which polyethylene is the most common polymer in all sample types. FTIR-ATR spectra and surface morphology indicate that most of the microplastics have been strongly weathered. Energy dispersive X-ray spectroscopy analysis detected heavy metals associated with MPs like Cd, Pb, Cu, Zn, Ni and Fe. Filter-feeding clams like Donax sp. can provide valuable information on the spatial patterns of MP distribution, and so can act as bio-indicators in monitoring MP pollution in coastal areas.


Asunto(s)
Bivalvos , Contaminantes Químicos del Agua/análisis , Animales , Ecosistema , Monitoreo del Ambiente , India , Microplásticos , Plásticos
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