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2.
Nanomaterials (Basel) ; 14(9)2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38727361

RESUMEN

Electrodes are one of the key components that influence the performance of all-vanadium redox flow batteries (VRFBs). A porous graphite felt with modified fiber surfaces that can provide a high specific activation surface is preferred as the electrode of a VRFB. In this study, a simple binder-free approach is developed for preparing stable carbon nanotube modified graphite felt electrodes (CNT-GFs). Heat-treated graphite felt electrodes (H-GFs) are dip-coated using CNT homogeneous solution. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results conclude that CNT-GFs have less resistance, better reaction currents, and reversibility as compared to H-GF. Cell performances showed that CNT-GFs significantly improve the performance of a VRFB, especially for the CNT-GF served in the positive side of the VRFB. CNT presence increases the electrochemical properties of the graphite electrode; as a result, reaction kinetics for both VO2+/VO2+ and V3+/V2+ are improved. Positive CNT-GF (P-CNT-GF) configured VRFB exhibits voltage efficiency, coulombic efficiency, and energy efficiency of 85%, 97%, and 82%, respectively, at the operating current density of 100 mA cm-2. At high current density of 200 mA cm-2, the VRFB with P-CNT-GF shows 73%, 98%, and 72% of the voltage, coulombic, and energy efficiencies, respectively. The energy efficiency of the CNT-GF is 6% higher when compared with that of B-H-GF. The VRFB with CNT-GF can provide stable performance for 300 cycles at 200 mA cm-2.

3.
Nanomaterials (Basel) ; 14(9)2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38727394

RESUMEN

Iron redox flow batteries (IRFBs) are cost-efficient RFBs that have the potential to develop low-cost grid energy storage. Electrode kinetics are pivotal in defining the cycle life and energy efficiency of the battery. In this study, graphite felt (GF) is heat-treated at 400, 500 and 600 °C, and its physicochemical and electrochemical properties are studied using XPS, FESEM, Raman and cyclic voltammetry. Surface morphology and structural changes suggest that GF heat-treated at 500 °C for 6 h exhibits acceptable thermal stability while accessing the benefits of heat treatment. Specific capacitance was calculated for assessing the wettability and electrochemical properties of pristine and treated electrodes. The 600 °C GF has the highest specific capacitance of 34.8 Fg-1 at 100 mV s-1, but the 500 °C GF showed the best battery performance. The good battery performance of the 500 °C GF is attributed to the presence of oxygen functionalities and the absence of thermal degradation during heat treatment. The battery consisting of 500 °C GF electrodes offered the highest voltage efficiency of ~74%, Coulombic efficiency of ~94%, and energy efficiency of ~70% at 20 mA cm-2. Energy efficiency increased by 7% in a battery consisting of heat-treated GF in comparison to pristine GF. The battery is capable of operating for 100 charge-discharge cycles with an average energy efficiency of ~ 67% for over 100 cycles.

7.
ACS Appl Mater Interfaces ; 16(9): 11646-11655, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38387025

RESUMEN

Yttrium-doped barium zirconate (BZY) has garnered attention as a protonic conductor in intermediate-temperature electrolysis and fuel cells due to its high bulk proton conductivity and excellent chemical stability. However, the performance of BZY can be further enhanced by reducing the concentration and resistance of grain boundaries. In this study, we investigate the impact of manganese (Mn) additives on the sinterability and proton conductivity of Y-doped BaZrO3 (BZY). By employing a combinatorial pulsed laser deposition (PLD) technique, we synthesized BZY thin films with varying Mn concentrations and sintering temperatures. Our results revealed a significant enhancement in sinterability as Mn concentrations increased, leading to larger grain sizes and lower grain boundary concentrations. These improvements can be attributed to the elevated grain boundary diffusion of zirconium (Zr) cations, which enhances material densification. We also observed a reduction in Goldschmidt's tolerance factor with increased Mn substitution, which can improve proton transport. The high proton conduction of BZY with Mn additives in low-temperature and wet hydrogen environments makes it a promising candidate for protonic ceramic electrolysis cells and fuel cells. Our findings not only advance the understanding of Mn additives in BZY materials but also demonstrate a high-throughput combinatorial thin film approach to select additives for other perovskite materials with importance in mass and charge transport applications.

8.
World J Microbiol Biotechnol ; 40(3): 82, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38285311

RESUMEN

Dunaliella salina is a favourable source of high lipid feedstock for biofuel and medicinal chemicals. Low biomass output from microalgae is a significant barrier to industrial-scale commercialisation. The current study aimed to determine how photosynthetic efficiency, carbon fixation, macromolecular synthesis, accumulation of neutral lipids, and antioxidative defence (ROS scavenging enzyme activities) of D. salina cells were affected by different light intensities (LI) (50, 100, 200, and 400 µmol m-2 s-1). The cells when exposed to strong light (400 µmol m-2 s-1) led to reduction in chlorophyll a but the carotenoid content increased by 19% in comparison to the control (LI 100). The amount of carbohydrate changed significantly under high light and in spite of stress inflicted on the cells by high irradiation, a considerable increase in activity of carbonic anhydrase and fixation rate of CO2 were recorded, thus, preserving the biomass content. The high light exposed biomass when subjected to nitrogen-deficient medium led to increase in lipid content (59.92% of the dry cell weight). However, neutral lipid made up 78.26% of the total lipid while other lipids like phospholipid and glycolipid content decreased, showing that the lipid was redistributed in these cells under nitrogen deprivation, making the organism more appropriate for biodiesel/jet fuel use. Although D. salina cells had a relatively longer generation time (3.5 d) than other microalgal cells, an economic analysis concluded that the amount of carotenoid they produced and the quality of their lipids made them more suited for commercialization.


Asunto(s)
Biocombustibles , Microalgas , Clorofila A , Carbono , Carotenoides , Glucolípidos , Nitrógeno
9.
Indian J Ophthalmol ; 72(2): 190-194, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38099361

RESUMEN

PURPOSE: There has been a sudden increase in the number of rhino-orbital mucormycosis cases, primarily affecting patients recovering from COVID-19 infection. The local health authorities have declared the current situation an epidemic. In this study, we assess the role of exenteration in preventing disease progression and improving survival in patients with rhino-orbital mucormycosis. METHODS: The patients undergoing exenteration were grouped into the exenteration arm and those denying exenteration were grouped into the nonexenteration arm. The patients were followed at 1 month and 3 months. The 6-month survival data were collected telephonically. Continuous data were presented as Mean ± SD/Median (IQR) depending on the normality distribution of data, whereas the frequency with percentages was used to present the categorical variables. Kaplan-Meier survival curves were created to estimate the difference in survival of patients with exenteration in rhino-orbital mucormycosis versus those without exenteration. RESULTS: A total of 14 patients were recruited for our study based on the inclusion and exclusion criteria. All the patients were qualified for exenteration; however, only eight patients underwent exenteration and six patients did not consent to exenteration. At the end of 3 months in the exenteration group, four (50%) patients died. Two patients died within a week of exenteration, whereas two patients died after 2 weeks of exenteration. The deaths in the first week were attributed to septic shock and the deaths happening beyond 2 weeks were attributed to severe meningitis. The Kaplan-Meier survival analysis showed the cumulative probability of being alive at 1 month in the exenteration arm to be 85%, and it decreased to 67% by 53 days and subsequently remained stable until the end of 3 months. CONCLUSION: The Kaplan-Meier survival analysis did not show a survival benefit of exenteration at 3 months and 6 months in COVID-associated rhino-orbital mucormycosis.


Asunto(s)
COVID-19 , Oftalmopatías , Infecciones Fúngicas del Ojo , Mucormicosis , Enfermedades Orbitales , Humanos , Mucormicosis/complicaciones , Mucormicosis/diagnóstico , Mucormicosis/cirugía , Enfermedades Orbitales/diagnóstico , Enfermedades Orbitales/cirugía , Enfermedades Orbitales/tratamiento farmacológico , Infecciones Fúngicas del Ojo/tratamiento farmacológico , COVID-19/complicaciones , Antifúngicos/uso terapéutico
11.
Curr Microbiol ; 81(1): 22, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38017305

RESUMEN

Microbial community exhibit shift in composition in response to temperature variation. We report crude oil-degrading activity and high-throughput 16S rRNA gene sequencing (metagenome) profiles of four bacterial consortia enriched at three different temperatures in crude oil-amended Bushnell-Hass Medium from an oily sludge sediment. The consortia were referred to as O (4 ± 2 â„ƒ in 3% w/v crude oil), A (25 ± 2 â„ƒ in 1% w/v crude oil), H (25 ± 2 â„ƒ in 3% w/v crude oil), and X (45 ± 2 â„ƒ in 3% w/v crude oil). The hydrocarbon-degrading activity was highest for consortium A and H and lowest for consortium O. The metagenome profile revealed the predominance of Proteobacteria (62.12-1.25%) in each consortium, followed by Bacteroidota (18.94-37.77%) in the consortium O, A, and H. Contrarily, consortium X comprised 7.38% Actinomycetota, which was essentially low (< 0.09%) in other consortia, and only 0.41% Bacteroidota. The PICRUSt-based functional analysis predicted major functions associated with the metabolism and 5060 common KEGG Orthology (KOs). A total of 296 KOs were predicted exclusively in consortium X. Additionally, 247 KOs were predicted from xenobiotic biodegradation pathways. This study found that temperature had a stronger influence on the composition and function of the bacterial community than crude oil concentration.


Asunto(s)
Consorcios Microbianos , Petróleo , Temperatura , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Consorcios Microbianos/genética , Hidrocarburos/metabolismo , Bacterias/genética , Bacterias/metabolismo , Biodegradación Ambiental , Petróleo/metabolismo , Bacteroidetes/genética
12.
Phys Chem Chem Phys ; 25(47): 32503-32514, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-37997153

RESUMEN

Metal-organic framework (MOF) based proton conductors are synthesized by the Avrami model (time-temperature modalities). Our objective here is to obtain a material with high proton conductivity in anhydrous conditions, improved catalytic behaviour and morphology control of conductivity, band gap and catalysis. For this purpose, we try to understand the role of morphology on mass transportation using computational fluid dynamics and the experimental realisation using the synthesis of MOF membranes with high protonic conductivity. In order to alter the morphology, the membranes are synthesized from protic ionic liquid (dimethyl ethyl amine H2PO4) and metal ion (Co3O4) at different temperatures and duration. A high protonic conductivity of 0.0286 S cm-1 with a high transference number >0.99 is observed in anhydrous conditions with the change in morphology. Furthermore, catalyst properties along with high activity (Tafel slope = 39 mV decade-1) with the alteration in morphology are also investigated in detail and observed adsorption governed conduction. This adsorption governed conduction is verified using computational fluid dynamics simulations with the alteration in morphology. This study suggests that morphology not only plays a pivotal role in obtaining a robust proton exchange membrane, it also improves the catalytic functionality and stability of the membrane.

13.
Indian J Ophthalmol ; 71(11): 3522-3527, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37870018

RESUMEN

Purpose: To determine the demographic and microbiological profile involved in the causation of corneal ulcers in Eastern India during the COVID era. Method: Patients presenting with corneal ulcers fulfilling the inclusion and exclusion criteria were taken as the case. The study duration was from January 2021 to December 2021. Socio-demographic details and information about risk factors were noted. A detailed corneal examination followed by corneal scraping was performed for microbiological evaluation. Results: In 1 year, 99 infective corneal ulcer patients were evaluated. Farmers (24.2%) were found to be maximally affected by corneal ulcers. The peak in cases was recorded from October to December (38.4%). Ocular trauma was the commonest risk factor (42.4%). The majority (80.8%) of patients were already on some topical antimicrobials. 22.2% of samples showed fungal filaments on KOH mount; 54.5% of these cases turned out to be culture-positive. 17.56% of KOH-negative samples turned out to be culture-positive (fungal). Overall, the culture positivity rate was 28.28% out of which fungal isolates were 89.28% and bacterial isolates were 10.72%. Fusarium species were identified as the most common organism contributing 42.85%, followed by Aspergillus fumigatus (14.28%). 10.72% of cases were culture positive for Pseudomonas aeuroginosa. Conclusion: Trauma with the organic matter was the predominant cause of fungal keratitis. In this study, fungal keratitis was found to be more common. Fusarium was the most common isolate.


Asunto(s)
COVID-19 , Úlcera de la Córnea , Infecciones Fúngicas del Ojo , Humanos , Úlcera de la Córnea/diagnóstico , Úlcera de la Córnea/epidemiología , Úlcera de la Córnea/microbiología , Estudios Transversales , Atención Terciaria de Salud , Úlcera , Incidencia , COVID-19/epidemiología , Infecciones Fúngicas del Ojo/diagnóstico , Infecciones Fúngicas del Ojo/epidemiología , Infecciones Fúngicas del Ojo/microbiología , Centros de Atención Terciaria , India/epidemiología , Estudios Retrospectivos
15.
Metabolites ; 13(5)2023 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-37233626

RESUMEN

Untargeted metabolomics of moderately resistant wild tomato species Solanum cheesmaniae revealed an altered metabolite profile in plant leaves in response to Alternaria solani pathogen. Leaf metabolites were significantly differentiated in non-stressed versus stressed plants. The samples were discriminated not only by the presence/absence of specific metabolites as distinguished markers of infection, but also on the basis of their relative abundance as important concluding factors. Annotation of metabolite features using the Arabidopsis thaliana (KEGG) database revealed 3371 compounds with KEGG identifiers belonging to biosynthetic pathways including secondary metabolites, cofactors, steroids, brassinosteroids, terpernoids, and fatty acids. Annotation using the Solanum lycopersicum database in PLANTCYC PMN revealed significantly upregulated (541) and downregulated (485) features distributed in metabolite classes that appeared to play a crucial role in defense, infection prevention, signaling, plant growth, and plant homeostasis to survive under stress conditions. The orthogonal partial least squares discriminant analysis (OPLS-DA), comprising a significant fold change (≥2.0) with VIP score (≥1.0), showed 34 upregulated biomarker metabolites including 5-phosphoribosylamine, kaur-16-en-18-oic acid, pantothenate, and O-acetyl-L-homoserine, along with 41 downregulated biomarkers. Downregulated metabolite biomarkers were mapped with pathways specifically known for plant defense, suggesting their prominent role in pathogen resistance. These results hold promise for identifying key biomarker metabolites that contribute to disease resistive metabolic traits/biosynthetic routes. This approach can assist in mQTL development for the stress breeding program in tomato against pathogen interactions.

16.
Indian J Ophthalmol ; 71(3): 957-961, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36872717

RESUMEN

Purpose: To analyze the correlation between the mean retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness with axial length and refractive errors among children aged 5-15 years. Methods: This cross-sectional, observational study was done on 130 eyes of 65 consecutive subjects with refractive errors. The patients were evaluated for RNFL thickness and macular GCL thickness using spectral domain- optical coherence tomography. Results: One hundred and thirty eyes of 65 subjects aged between 5 and 15 years were divided into three groups based on their spherical equivalent in diopters (D). The children with a spherical equivalent of ≤-0.50 D were considered myopic, ≥-0.5 to ≤+0.5 D were considered emmetropic, and ≥+0.50 D were considered hypermetropic. RNFL thickness and GCL thickness were correlated with age, gender, spherical equivalent, and axial length. The mean global RNFL thickness was 104.58 µm ± 7.567. Conclusion: There exists a negative correlation between RNFL thickness and macular GCL thickness with increasing severity of myopia and increase in axial length, and the possible reason could be stretching of the sclera, which further leads to stretching of the retina, resulting in thinner RNFL and macular GCL thickness.


Asunto(s)
Miopía , Errores de Refracción , Humanos , Niño , Preescolar , Adolescente , Estudios Transversales , Retina , Fibras Nerviosas
17.
Mar Pollut Bull ; 190: 114842, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36965269

RESUMEN

Selenium (Se) is an essential element for living systems, however, toxic at higher levels. In the present study, Dunaliella salina cells were exposed to different Se concentrations for their growth (EC50 195 mg L-1) as well as Se accumulation. The cells exposed to 50 mg L-1 Se showed photoautotrophic growth parallel to control and accumulated 65 µg Se g-1 DW. A decrease in photosynthetic quantum yield, chlorophyll content, and the increase in intracellular reactive oxygen species, proline content, and lipid peroxidation accompanied by higher neutral lipid accumulation, were recorded at higher Se level. The enzymes superoxide dismutase and catalase played a pivotal role in antioxidative defense. Heterogeneity in accumulated carotenoids at varying concentrations of selenium was prevalent. The cells exposed to 200 mg L-1 Se resulted in the disorganization of organelles. Thus, the Se enriched biomass obtained at 50 mg L-1 may be explored for bio-fortification of food and feed.


Asunto(s)
Microalgas , Selenio , Antioxidantes/metabolismo , Selenio/toxicidad , Especies Reactivas de Oxígeno , Microalgas/metabolismo , Bioacumulación , Fotosíntesis , Clorofila , Lípidos
18.
Indian J Ophthalmol ; 71(1): 320, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36588275

RESUMEN

Background: In acute chemical injury, damage can range from ocular surface epithelial defects to limbal and scleral ischemia. This may subsequently progress to corneal or scleral melting and perforation and finally result in phthisis bulbi. Thus, acute chemical injury is a potentially blinding condition and warrants attention. The accurate technique to assess the damage incurred should be practiced to avoid undertreatment and subsequent complications. Surgical intervention wherever needed should be appropriately timed and should be performed. The primary aim of medical or surgical intervention in acute chemical injury is to attain a stable and epithelized ocular surface. Even a conjunctival phenotype over the cornea is a desirable outcome. Purpose: This video discusses the nuances involved in the assessment and planning of Tenon advancement with amniotic membrane grafting for treating limbal ischemia in acute chemical injury. Synopsis: The video demonstrates the technique of restoration of limbal vascularization by performing Tenon advancement with amniotic membrane grafting and its outcome. Highlights: Ocular surface painting with fluorescein dye is essential to assess the areas of surface involvement. Merely instilling the fluorescein dye in the cul-de-sac will underestimate the extent of the damage. Tenon advancement should ideally be planned between 7 and 10 days following an injury when actual limbal blanching is obvious. A stable and epithelized ocular surface is the desirable outcome irrespective of the epithelial phenotype. Video Link: https://youtu.be/06XhwLKnsIA.


Asunto(s)
Quemaduras Químicas , Quemaduras Oculares , Limbo de la Córnea , Humanos , Córnea , Esclerótica , Conjuntiva , Isquemia , Fluoresceínas , Quemaduras Químicas/complicaciones , Quemaduras Químicas/diagnóstico , Quemaduras Químicas/cirugía , Limbo de la Córnea/cirugía , Quemaduras Oculares/inducido químicamente , Quemaduras Oculares/complicaciones , Quemaduras Oculares/diagnóstico
19.
J Biomol Struct Dyn ; 41(15): 7069-7083, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36017823

RESUMEN

In the present study little explored halotolerant wall-less green alga Dunaliella salina was found to be a potent source of antibacterial and antifungal biomolecules. Both the target pathogens, bacteria (Escherischia coli, Klebsiella pneumoniae, and Acinetobacter baumannii) and fungi (Candida albicans, C. tropicalis, and Cryptococus sp.) were WHO prioritized. The bioassay guided approach led us to evaluate antibacterial and antifungal lead molecule(s) from an array of compounds using spectroscopic and in silico studies. The methanol derived crude extract was purified via thin layer chromatography (TLC) using solvent system methanol: chloroform (1:19). Maximum antimicrobial activity was observed in fractions D5, D6 and D7, the components of which were then recognized using high resolution-liquid chromatography/mass spectroscopy (Orbitrap) (HR-LC/MS). The screened compounds were then docked with target enzymes sterol-14-alpha demethylase and OmpF porin protein. The energy scores revealed that amongst all, lariciresinol-4-O-glucoside showed better binding affinity, in silico, using the Schrödinger Maestro 2018-1 platform. The 3-dimensional crystal structures of both the proteins were retrieved from the protein data bank (PDB), and showed binding energies of -14.35 kcal/mol, and -11.0 kcal/mol against respective drug targets. The molecular dynamics (MD) simulations were performed for 100 ns, using Desmond package, Schrödinger to evaluate the conformational stability and alteration of protein-ligand complexes during the simulation. Thus, our findings confirmed that lariciresinol-4-O-glucoside, a lignan derivative and known strong antioxidant, may be used as an important "lead" molecule to be developed as antibacterial and antifungal drugs in the future.Communicated by Ramaswamy H. Sarma.

20.
Indian J Ophthalmol ; 70(12): 4470-4471, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36453378

RESUMEN

Background: Steven-Johnson syndrome (SJS) is a serious disorder affecting the skin and mucous membrane, causing multiple flaccid bullae and purpuric rashes with sheet-like epithelial detachment including the ocular surface. The long-term outcomes following SJS are dismal and manifest as corneal vascularization, lid-wiper keratopathy, and severe dry eyes. The disease course can be modified if amniotic membrane graft is performed at the first week of disease, and the above-said complications can be avoided. This procedure thus not only decreases the morbidity but also improves the quality of life. Purpose: This video discusses the long-term sequelae of SJS which can be modified with timely intervention during the acute stage and thus significantly decreases morbidity. Synopsis: The video demonstrates the simple technique of amniotic membrane transplantation in the acute stage in SJS and its impact in long run. Highlights: There should be a low threshold for doing early amniotic membrane transplantation in patients with SJS with ocular surface involvement. Early intervention can change the disease course and decrease disease morbidity significantly. Video link: https://youtu.be/qgIiVcW56Oo.


Asunto(s)
Amnios , Calidad de Vida , Humanos , Ojo , Cara , Piel , Progresión de la Enfermedad
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