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1.
Front Chem ; 12: 1381144, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38736687

RESUMO

The photo-enhanced electrocatalytic method of oxygen evolution reaction (OER) shows promise for enhancing the effectiveness of clear energy generation through water splitting by using renewable and sustainable source of energy. However, despite benefits of photoelectrocatalytic (PEC) water splitting, its uses are constrained by its low efficiency as a result of charge carrier recombination, a large overpotential, and sluggish reaction kinetics. Here, we illustrate that Nickel telluride (NiTe) synthesized by hydrothermal methods can function as an extremely effective photo-coupled electrochemical oxygen evolution reaction (POER) catalyst. In this study, NiTe was synthesized by hydrothermal method at 145°C within just an hour of reaction time. In dark conditions, the NiTe deposited on carbon cloth substrate shows a small oxygen evolution reaction overpotential (261 mV) at a current density of 10 mA cm-2, a reduced Tafel slope (65.4 mV dec-1), and negligible activity decay after 12 h of chronoamperometry. By virtue of its enhanced photo response, excellent light harvesting ability, and increased interfacial kinetics of charge separation, the NiTe electrode under simulated solar illumination displays exceptional photoelectrochemical performance exhibiting overpotential of 165 mV at current density of 10 mA cm-2, which is about 96 mV less than on dark conditions. In addition, Density Functional Theory investigations have been carried out on the NiTe surface, the results of which demonstrated a greater adsorption energy for intermediate -OH on the catalyst site. Since the -OH adsorption on the catalyst site correlates to catalyst activation, it indicates the facile electrocatalytic activity of NiTe owing to favorable catalyst activation. DFT calculations also revealed the facile charge density redistribution following intermediate -OH adsorption on the NiTe surface. This work demonstrates that arrays of NiTe elongated nanostructure are a promising option for both electrochemical and photoelectrocatalytic water oxidation and offers broad suggestions for developing effective PEC devices.

2.
ACS Mater Au ; 4(3): 274-285, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38737119

RESUMO

Hastening the progress of rechargeable metal-air batteries and hydrogen fuel cells necessitates the advancement of economically feasible, earth-abundant, inexpensive, and efficient electrocatalysts facilitating both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Herein, a recently reported family of nano (5A1/5)Co2O4 (A = combinations of transition metals, Mg, Mn, Fe, Ni, Cu, and Zn) compositionally complex oxides (CCOs) [Wang et al., Chemistry of Materials, 2023,35 (17), 7283-7291.] are studied as bifunctional OER and ORR electrocatalysts. Among the different low-temperature soft-templating samples, those subjected to 600 °C postannealing heat treatment exhibit superior performance in alkaline media. One specific composition (Mn0.2Fe0.2Ni0.2Cu0.2Zn0.2)Co2O4 exhibited an exceptional overpotential (260 mV at 10 mA cm-2) for the OER, a favorable Tafel slope of 68 mV dec-1, excellent onset potential (0.9 V) for the ORR, and lower than 6% H2O2 yields over a potential range of 0.2 to 0.8 V vs the reversible hydrogen electrode. Furthermore, this catalyst displayed stability over a 22 h chronoamperometry measurement, as confirmed by X-ray photoelectron spectroscopy analysis. Considering the outstanding performance, the low cost and scalability of the synthesis method, and the demonstrated tunability through chemical substitutions and processing variables, CCO ACo2O4 spinel oxides are highly promising candidates for future sustainable electrocatalytic applications.

3.
ACS Omega ; 9(13): 15697-15708, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38585072

RESUMO

The bipodal compounds [(TMG2biphenN-R)CuI-NCMe](PF6) (R = Me, Ar (4-CF3Ph-)) and [(TMG2biphenN-Me)CuI-I] have been synthesized with ligands that feature a diarylmethyl- and triaryl-amine framework and superbasic tetramethylguanidinyl residues (TMG). The cationic Cu(I) sites mediate catalytic nitrene-transfer reactions between the imidoiodinane PhI = NTs (Ts = tosyl) and a panel of styrenes in MeCN, to afford aziridines, demonstrating comparable reactivity profiles. The copper reagents have been further explored to execute C-H amination reactions with a variety of aliphatic and aromatic hydrocarbons and two distinct nitrene sources PhI = NTs and PhI = NTces (Tces = 2,2,2-trichloroethylsulfamate) in benzene/HFIP (10:2 v/v). Good yields have been obtained for sec-benzylic and tert-C-H bonds of various substrates, especially with the more electron-deficient catalyst [(TMG2biphenN-Ar)CuI-NCMe](PF6). In conjunction with earlier studies, the order of reactivity of these bipodal cationic reagents as a function of the metal employed is established as Cu > Fe > Co ≥ Mn. However, as opposed to the base-metal analogues, the bipodal Cu reagents are less reactive than a similar tripodal Cu catalyst. The observed fluorophilicity of the bipodal Cu compounds may provide a deactivation pathway.

4.
ACS Appl Mater Interfaces ; 16(6): 7014-7025, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38308595

RESUMO

Developing highly active and stable electrocatalysts for the oxygen evolution reaction (OER) is key to improving the efficiency and practical application of various sustainable energy technologies including water electrolysis, CO2 reduction, and metal air batteries. Here, we use evaporation-induced self-assembly (EISA) to synthesize highly porous fluorite nanocatalysts with a high surface area. In this study, we demonstrate that a 50% rare-earth cation substitution for Ce in the CeO2 fluorite lattice improves the OER activity and stability by introducing oxygen vacancies into the host lattice, which results in a decrease in the adsorption energy of the OH* intermediate in the OER. Among the binary fluorite compositions investigated, Nd2Ce2O7 is shown to display the lowest OER overpotential of 243 mV, achieved at a current density of 10 mA cm-2, and excellent cycling stability in an alkaline medium. Importantly, we demonstrate that rare-earth oxide OER electrocatalysts with high activity and stability can be achieved using the EISA synthesis route without the incorporation of transition and noble metals.

5.
Int J Surg Pathol ; 32(3): 496-506, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37489265

RESUMO

Background. Spindle cell/sclerosing rhabdomyosarcoma is a rare neoplasm and has an aggressive clinical course. Because of its rarity, we performed a multi-institutional collaboration to comprehend the overarching clinical, histopathological, and immunohistochemical characteristics of a cohort of spindle cell/sclerosing rhabdomyosarcoma. Materials and Methods. Forty-five patients with spindle cell/sclerosing rhabdomyosarcoma were identified. Demographics, clinical, histopathological, and immunohistochemistry data were reviewed and recorded. Results. The patients' age ranged from 1 to 85 years with a male to female ratio of 1.2:1. There were 15 children/adolescents and 30 adults. Eighteen (40%) tumors were located in the head and neck region. Twenty-four (53%) tumors displayed a bimorphic cellular arrangement with hypercellular areas having short, long, and sweeping fascicular and herringbone pattern, and hypocellular areas with stromal sclerosis and associated hyalinized and/or chondromyxoid matrix. Histomorphological differentials considered were leiomyosarcoma, malignant peripheral nerve sheath tumor, fibrosarcoma, nodular fasciitis, liposarcoma, synovial sarcoma, sarcomatoid carcinoma, solitary fibrous tumor, dermatofibrosarcoma protuberans, and schwannoma. Six tumors exhibited marked stromal sclerosis. The myogenic nature was confirmed by immunohistochemistry. Positivity for at least one skeletal muscle-associated marker (MyoD1 and/or myogenin) was observed. Conclusion. Spindle cell/sclerosing rhabdomyosarcoma diagnosis can be challenging as a number of malignant spindle cell neoplasm mimic this entity. Thus a correct diagnosis requires immunohistochemical work up with a broad panel of antibodies. In view of rarity of this neoplasm, further studies on a large cohort of patients with clinical follow-up data are needed for a better understanding of this tumor.


Assuntos
Neurofibrossarcoma , Rabdomiossarcoma , Adulto , Criança , Adolescente , Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Imuno-Histoquímica , Esclerose/patologia , Rabdomiossarcoma/diagnóstico , Rabdomiossarcoma/patologia , Músculo Esquelético/patologia , Biomarcadores Tumorais
6.
Genome ; 67(4): 119-124, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38091581

RESUMO

Bergenia ciliata (Haw.) Sternb. is an important herb predominantly found in the Indian Himalayan Region. It is widely used in medicines, healthcare systems, cosmetics, fodder, and ornamental purposes. The Illumina sequencing and de novo transcriptome assembly were carried out in B. ciliata to develop and identify simple sequence repeat markers. A total of 18 226 simple sequence repeats (SSRs) were identified wherein di-nucleotides were found to be abundant (47.88%), followed by mono-nucleotide (35.03%) and tri-nucleotide (15.88%) repeats. A total of 11 839 EST-SSR primers were designed, of which 96 primer pairs were commercially synthesized. Finally, 17 primer pairs revealed clear, distinct polymorphic bands, and these primers were validated with 40 diverse B. ciliata accessions. The present study revealed moderate level of genetic diversity (Ho = 0.389, He = 0.542, and PIC = 0.513). Furthermore, the transcriptome data and EST-SSR markers generated during the present investigation could be an important genetic resource for functional genomics, population studies, and conservation genetics of the genus Bergenia.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Transcriptoma , Marcadores Genéticos , Etiquetas de Sequências Expressas , Repetições de Microssatélites
7.
J Phys Condens Matter ; 51(2)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36322978

RESUMO

Based on first-principles calculations, the anomalous Hall conductivity (AHC) and anomalous Nernst conductivities (ANCs) of the XMnP (X = Ti, Zr, Hf) compounds are evaluated, and the possibility to tailor such properties in compounds susceptible to changing the magnetization directions is also investigated. We observe large changes in the calculated AHC and ANC for different magnetization directions that are originating from changes in the band structure all over the whole Brillouin zone. Our study gives a promising clue on engineering magnetic intermetallic compounds for tunable transverse thermoelectric applications.

8.
Chem Commun (Camb) ; 58(60): 8360-8363, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35792052

RESUMO

Nickel selenide nanowires were grown inside carbon nanotubes through in situ encapsulation via one-step chemical vapor deposition. These NiSe2@CNT nanohybrids showed excellent electrocatalytic activity for water splitting with a low overpotential of 260 mV at 10 mA cm-2, high current density, and extended stability owing to the synergistic effect between NiSe2 and CNTs.

9.
J Public Health Afr ; 13(Suppl 2): 2422, 2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37497135

RESUMO

Having psychological advantage that enables athletes to perform at their best regardless of challenges and adversity is what is meant by having mental toughness (MT). In order to better understand the mental toughness of elite Indian standing and sitting para-thrower athletes, this study looked at a variety of mental sub - scales. Elite para-throwers who competed at the international level, consider making up the sample of the current study; which includes a total of nine elite para-throwers [5 Standing Para-throwers (StPT) and 4 Seated Para-throwers (SePT)]. The researcher used the Psychological Performance Inventory (PPI), designed by Loehr, and the Personal Demographic Information form to gather data in order to ascertain the participants' attitudes of mental toughness. An independent T-test with 0.05 significance level was performed for the research's findings, there are no statistical significant difference between the two groups' levels of motivation, self-confidence, ability to control negative energy, attention, visualisation, ability to control positive energy, and attitude control factors of MT. Elite Indian para-thrower athletes' mental toughness is similar in both groups, with no discernible differences.

10.
ACS Appl Mater Interfaces ; 13(27): 32415-32423, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34186000

RESUMO

Utilizing the molecular beam epitaxy technique, a nanoscale thin-film magnet of c-axis-oriented Sm2Co17 and SmCo5 phases is stabilized. While typically in the prototype Sm(Co, Fe, Cu, Zr)7.5-8 pinning-type magnets, an ordered nanocomposite is formed by complex thermal treatments, here, a one-step approach to induce controlled phase separation in a binary Sm-Co system is shown. A detailed analysis of the extended X-ray absorption fine structure confirmed the coexistence of Sm2Co17 and SmCo5 phases with 65% Sm2Co17 and 35% SmCo5. The SmCo5 phase is stabilized directly on an Al2O3 substrate up to a thickness of 4 nm followed by a matrix of Sm2Co17 intermixed with SmCo5. This structural transition takes place through coherent atomic layers, as revealed by scanning transmission electron microscopy. Highly crystalline growth of well-aligned Sm2Co17 and SmCo5 phases with coherent interfaces result in strong exchange interaction, leading to enhanced magnetization and magnetic coupling. The arrangement of Sm2Co17 and SmCo5 phases at the nanoscale is reflected in the observed magnetocrystalline anisotropy and coercivity. As next-generation permanent magnets require designing of materials at an atomic level, this work enhances our understanding of self-assembling and functioning of nanophased magnets and contributes to establishing new concepts to engineer the microstructure for beyond state-of-the-art magnets.

11.
Cureus ; 13(12): e20775, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35111460

RESUMO

Non-motor symptoms of Parkinson's disease (PD), such as insomnia and restless legs syndrome (RLS), tend to worsen and become refractory as neurodegeneration progresses. We report the case of a 72-year-old female with a six-year history of PD and two-and-half-year history of insomnia and refractory RLS. We added a neuroprotective agent, Withania somnifera, to the existing treatment regimen for her insomnia. Besides the partial remission of her insomnia and motor symptoms of PD, there was a complete reversal of the RLS symptoms. Withania somnifera has been shown to improve PD symptoms by preventing oxidative damage of the nigrostriatal dopaminergic neurons and improving dopamine levels in the midbrain and corpus striatum. Our case provides the first-time evidence where Withania somnifera added for insomnia caused a complete remission of refractory RLS, possibly due to its anti-apoptotic and pro-dopaminergic actions. Withania somnifera could prove beneficial in cases where the disease advances but further addition of dopamine agonists for refractory RLS is not possible due to the risk of dopamine augmentation.

12.
Nat Commun ; 11(1): 4849, 2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973128

RESUMO

Owing to electric-field screening, the modification of magnetic properties in ferromagnetic metals by applying small voltages is restricted to a few atomic layers at the surface of metals. Bulk metallic systems usually do not exhibit any magneto-electric effect. Here, we report that the magnetic properties of micron-scale ferromagnetic metals can be modulated substantially through electrochemically-controlled insertion and extraction of hydrogen atoms in metal structure. By applying voltages of only ~ 1 V, we show that the coercivity of micrometer-sized SmCo5, as a bulk model material, can be reversibly adjusted by ~ 1 T, two orders of magnitudes larger than previously reported. Moreover, voltage-assisted magnetization reversal is demonstrated at room temperature. Our study opens up a way to control the magnetic properties in ferromagnetic metals beyond the electric-field screening length, paving its way towards practical use in magneto-electric actuation and voltage-assisted magnetic storage.

13.
J Phys Condens Matter ; 31(50): 505504, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31470439

RESUMO

We investigated the cubic-hexagonal phase transition and its effect on thermoelectric performance in Li-based Nowotny-Juza phases LiZn X (X = N, P, As, Sb, and Bi). Interestingly, other than LiZnSb, the cubic LiZnBi is found to be energetically more favorable than the hitherto reported hexagonal phase. The hexagonal phases of reported cubic LiZnP and LiZnAs are likely to be stabilized by pressure-hydrostatic pressure can be aided by internal pressure. We find that while power factor values are much improved in the proposed hexagonal phases, the values in cubic phases are also impressive. We also determine conservative estimates of the figure of merit. The ZT values of cubic and hexagonal LiZnSb at 700 K are 1.27 and 1.95, respectively. Other promising values are 1.96 and 1.49 at 700 K of hexagonal n-type LiZnP and LiZnAs, respectively. Overall, our findings suggest the good thermoelectric potential of Nowotny-Juza phases.

14.
J Phys Condens Matter ; 31(40): 405902, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31226705

RESUMO

Based on high throughput density functional theory calculations, we evaluated systematically the stability of 580 M2AX compounds. The thermodynamic, mechanical, and dynamical stability and the magnetic structure are calculated. We found 20 compounds fulfilling all three stability criteria, confirming Cr2AlC, Cr2GeC, Cr2GaC, Cr2GaN, and Mn2 GaC, which have been synthesized. The stability trends with respect to the M- and A-elements are discussed by analyzing the formation energies, indicating that Cr and Mn containing M2AX compounds are more stable than Fe, Co, or Ni containing compounds. Further insights on the stability are obtained by detailed analysis of the crystal orbital Hamilton population (COHP).

15.
Waste Manag ; 87: 719-730, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31109575

RESUMO

Appropriate recycling of waste to reusable materials is much sought after in the scientific community to control the incessant rising pollution in environment due to insufficient management of waste materials. To address this issue, efforts were directed to obtain SnO2-Fe3O4 nanocomposites from scrap tin plated steel and the use of these composites for the degradation of organic pollutant. We have demonstrated a novel, efficient and facile hydrometallurgy approach for the extraction of iron from waste tin plated steel containers found in plenty in the common waste generated in society. The extracted iron has further been utilized for the preparation of SnO2:Fe3O4 nanocomposites with different compositions (SnO2:Fe3O4 ratio of 93.2:6.8, 85:15, 58:42 and 40:60) using hydrothermal route. The photocatalytic activities of nanocomposite were determined spectroscopically using Rhodamine-B (RhB) as a model dye. Our results indicate that among all the composites with SnO2 (85%):Fe3O4 (15%) exhibits the best photocatalytic efficiency under UV light whereas the composition of SnO2 (93.2%):Fe3O4 (6.28%) is the most efficient in visible light. The above visible light efficiency was supported by density functional theory (DFT) studies which suggest a small amount of pure Fe is present at the Sn sites in the nanocomposite, leading to the reduction in the band gap of the nanocomposite and resulting in absorption in the visible range. Thus, in the present study, we have shown a process of conversion of waste to nanomaterials and its utilization for treatment of organic pollutants.


Assuntos
Poluentes Ambientais , Nanocompostos , Catálise , Luz , Raios Ultravioleta
16.
ACS Appl Mater Interfaces ; 8(23): 14586-95, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27225061

RESUMO

Because of the outstanding high theoretical specific energy density of 2600 Wh kg(-1), the lithium-sulfur (Li-S) battery is regarded as a promising candidate for post lithium-ion battery systems eligible to meet the forthcoming market requirements. However, its commercialization on large scale is thwarted by fast capacity fading caused by the Achilles' heel of Li-S systems: the polysulfide shuttle. Here, we merge the physical features of carbon-coated separators and the unique chemical properties of N and S codoped mesoporous carbon to create a functional hybrid separator with superior polysulfide affinity and electrochemical benefits. DFT calculations revealed that carbon materials with N and S codoping possess a strong binding energy to high-order polysulfide species, which is essential to keep the active material in the cathode side. As a result of the synergistic effect of N, S dual-doping, an advanced Li-S cell with high specific capacity and ultralow capacity degradation of 0.041% per cycle is achieved. Pushing our simple-designed and scalable cathode to a highly increased sulfur loading of 5.4 mg cm(-2), the Li-S cell with the functional hybrid separator can deliver a remarkable areal capacity of 5.9 mAh cm(-2), which is highly favorable for practical applications.

17.
Anc Sci Life ; 31(3): 137-40, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23284221

RESUMO

The present article deals with the unknown traditional uses of 15 plant species for the treatment of hydrocele, collected from 27 tribal groups ofthe Sundargarh, Mayurbhanj, Angul, and Balangir districts of Odisha. These ethnomedicinal uses were compared and cross-checked with the data mentioned in the well-known, standard, Indian ethnomedicinal as well as medicinal literatures and it was found that these medicinal uses of the referred plants had not been reported earlier.

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