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1.
Small Methods ; : e2400368, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38745535

ABSTRACT

The development of highly efficient electrocatalysts for the ethanol oxidation reaction (EOR) is essential for the commercialization of direct ethanol fuel cells, yet challenges remain. In this study, a one-pot solution-phase method to synthesize Pd nanowire networks (NNWs) with very high surface-to-volume ratio having numerous twin and grain boundaries is developed. Using the same method, the Pd lattice is further engineered by introducing Ag and Cu atoms to produce AgPd, and CuPd alloy structure which significantly shifts the Pd d-band center upward and downward, respectively due to strain and ligand effects. Theoretical analysis employing density functional theory (DFT) demonstrates that such modification of the d-band center significantly influences the adsorption energies of reactants on the catalytic surface. Owing to their notably high surface-to-volume ratio and the presence of multiple twin and grain boundaries, Pd NNWs demonstrate significantly enhanced electrocatalytic activity toward EOR, ≈7.2 times greater than that of commercial Pd/C. Remarkably, compared to Pd NNWs, AgPd, and CuPd NNWs display enlarged and reduced electrocatalytic activity toward EOR, respectively. Specifically, Ag4Pd7 NNWs achieve a remarkable mass activity of 9.00 A mgpd -1 for EOR, which is 13.6 times higher than commercial Pd/C.

2.
Inorg Chem ; 63(13): 6092-6102, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38507817

ABSTRACT

In this work, we illustrated the design and development of a metal-coordinated porous organic polymer (POP) namely VO@TPA-POP via a post-synthetic metalation strategy to incorporate oxo-vanadium sites in a pristine polymer (TPA-POP) having acetylacetonate (acac) as anchoring moiety. The as-synthesized VO@TPA-POP exhibited highly robust and porous framework, which has been utilized for thioanisole (TA) oxidation to its corresponding sulfoxide. The catalyst demonstrated notable stability and recyclability by maintaining its catalytic activity over multiple reaction cycles without any significant loss in activity. The X-ray absorption spectroscopy (XAS) and density functional theory (DFT) analysis establish the existence of V(+4) oxidation state along with the VO(O)4 active sites into the porous network and the most energetically feasible mechanistic pathway involved in the TA oxidation, respectively, indicating the role of electron density associated with vanadium center during the catalytic transformation. Thus, this work aims at the demonstration of versatility and potential of VO@TPA-POP as a porous heterogeneous catalyst for the TA oxidation followed by decontamination of sulfur mustards (HD's) to their corresponding less toxic sulfoxides in a more efficient and greener way.

3.
Small ; : e2309736, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-38459644

ABSTRACT

The direct alcohol fuel cells (DAFCs) rely on alcohol oxidation reactions (AORs) to produce electricity, which require catalysts with optimized electronic structure to accelerate the sluggish AORs. Herein, an epitaxial growth of Pd layer onto the pentatwinned Au@Ag core-shell nanorods (NRs) is reported to synthesize highly strained Au@AgPd core-shell NRs. The tensile strain in the AgPd shell of the Au@AgPd nanorods (NRs) arises not only from the core-shell lattice mismatch but also from twinning and lattice distortion occurring at the five twinned boundaries present in the structure. Theoretical simulations prove that the presence of tensile strains in the AgPd layer leads to a significant upward shift of the d-band center of the Pd site toward the Fermi level which remarkably changes the adsorption energy of alcohols on the surface. Highly strained Au@AgPd NRs show exceptional mass activities in electrochemical oxidation of biomass-derived alcohols (ethylene glycol, ethanol, and glycerol) reaching up to 18.66, 15.6, and 7.90 A mgpd -1 , respectively. These values are 23.3, 23.6, and 23.2 times higher than commercial Pd/C catalysts. This strain engineering strategy set the platform for the design and synthesis of highly efficient and versatile catalysts for the construction of high-performance DAFCs.

4.
Natl Acad Sci Lett ; 45(4): 363-369, 2022.
Article in English | MEDLINE | ID: mdl-35528283

ABSTRACT

Aim: To characterize Th1/Th2/Th17 cytokine profile (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, and IL-17A) among different stages of COVID-19 infection. Methods: This was a cross-sectional study which included six healthy individuals and 68 patients who were admitted with COVID-19 in the Department of Medicine, at All India Institute of Medical Sciences, New Delhi, from July 2020 to September 2020. Patients were categorized into mild, moderate, and severe COVID-19 groups, and serum samples were drawn for the measurement of Th1/Th2/Th17 cytokines (IL-4, IL-6, IL-10, TNF-α, IFN-γ, and IL-17A) which was done by BD™ Cytometric Bead Array. Results: All the cytokines showed dynamic expression in the COVID-19 group, of which only IL-6 was statistically significant. Among the three severity groups of COVID-19, increased severity did not transform into increased cytokine level, with the exception for IL-6, which was statistically significant. Conclusions: In our small sample study, six cytokines expressions were evaluated however most of them were elevated in COVID-19 patients but were not statistically significant except IL-6.

5.
Cureus ; 13(12): e20072, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34987936

ABSTRACT

Introduction During the coronavirus disease 2019 (COVID-19) pandemic in India, several characteristics of hospitalized COVID-19 patients, based on demographics, mortality predictors, and presence of comorbidities, were found to be associated with poor outcomes. The objective of this study was to identify such epidemiological and clinical characteristics among the patients admitted at a tertiary-care center in India that may have predisposed them to COVID-19-related mortality. Methods This retrospective observational study conducted at the Department of Medicine, All India Institute of Medical Sciences, New Delhi, in May 2021 included 141 COVID-19 confirmed patients. The medical history, demographic characteristics, comorbidities, clinical findings, and laboratory data of each patient were obtained. The data were analyzed to identify significant clinical and laboratory parameters that led to the adverse final outcomes. Results Hypertension was the most common comorbidity and the presence of diabetes with hypertension led to poorer final outcomes. Lower oxygen saturation and requirement of oxygen supplementation at admission along with worse prognostic scores during admission led to poorer outcomes. Twenty-seven patients needed non-invasive ventilation (NIV) during the hospital course, and all ultimately landed up among the 56 patients who were managed on invasive mechanical ventilation (IMV). Multivariate logistic regression analysis performed identified COVID-19 severity at admission, co-existence of hypertension and diabetes mellitus, systolic blood pressure less than 90 mm Hg, and serum creatinine greater than 1.2 mg/dL to be associated with higher COVID-19 mortality. Conclusion COVID-19 patients having the co-existence of diabetes and hypertension constitute a high-risk group and may be targeted by prompt vaccination strategies. The presence of severe disease along with a need for oxygen therapy and other intensive care interventions ultimately led to unfavorable outcomes.

6.
Int J Clin Pediatr Dent ; 12(6): 587-589, 2019.
Article in English | MEDLINE | ID: mdl-32440081

ABSTRACT

This is a case report of a 14-year-old female patient in whom a premolar from a donor was used as an allotransplant to replace her missing lower premolar. The treatment results over 6 months showed successful periodontal healing and functioning of the allotransplanted tooth. The aim of this paper is to report a procedure, allotransplantation of tooth, which is followed from ages but less preferred and documented and is surrounded by variable prognosis and also highlight the use of a intentionally extracted tooth for orthodontic purpose, which otherwise goes as a waste and moreover the use of this technique can supplement the need of an implant for the time being in the young patient without compromising her alveolar bone height, functioning, and esthetics. HOW TO CITE THIS ARTICLE: Pokhriyal A, Dhawan P, Chandra S, et al. A New Home for a Streetless Occupant: A Case Report. Int J Clin Pediatr Dent 2019;12(6):587-589.

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