Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 198
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
RSC Adv ; 14(31): 22159-22168, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39005245

RESUMO

Phosphate-based NASICON materials are an excellent candidate for both electrode and solid electrolyte materials in sodium-ion batteries (SIBs). The development of new NASICON materials with higher ionic and electronic conductivities based on low cost and abundant elements is necessary for advancement of SIBs. In this study, we report the structure, morphology and conductivity of the earth-abundant Mn/Fe-based NASICON phosphate Na4MnFe(PO4)3. Pure phase powders were synthesized by solution-assisted solid-state reaction, sol-gel and Pechini methods. From refined X-ray diffraction data, the prepared phosphate was found to crystallize in trigonal symmetry with space group R3̄c. The effect of synthesis method on microstructure and conductivity was investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM) and impedance measurements. Smaller particle size and regular distribution of the powder was designed using a Pechini route. Impedance measurement showed a notable enhancement in conductivity, from 0.543 × 10-7 to 1.52 × 10-7 S cm-1 at 30 °C, when the powder synthesis method was altered from a solution-assisted solid-state reaction to the Pechini route, highlighting the remarkable effect of the synthesis method on conductivity.

2.
Tunis Med ; 102(7): 423-428, 2024 Jul 05.
Artigo em Francês | MEDLINE | ID: mdl-38982968

RESUMO

INTRODUCTION: Chronic kidney disease (CKD) stage 5 is a common pathology, the increase in its incidence and prevalence has been noted worldwide. In Algeria, few studies have been done on the epidemiology of chronic kidney disease, the real extent of its incidence in southern Algeria remains unknown. AIM: To determine the incidence in 2017 of chronic kidney disease stage 5 treated by renal replacement in southeastern Algeria. METHOD: During our multicenter, prospective longitudinal regional study, from January 1, 2017 to December 31, 2017, all resident incident cases of CKD stage 5 treated in the region by renal replacement were recruited. RESULTS: The crude incidence of stage 5 CKD treated in 2017 in southeastern Algeria was 75 pmh. The age-standardized incidence rate was 100 pmh, with a male predominance, a M/F sex ratio of 1.59. The average age of incident cases was 48.50 ± 19.12 years. The incidence varies by age group and by wilaya. Diabetes (26.7%) and hypertensive nephropathy (22.6%) represent almost half of the cases and primary glomerulonephritis represents 5.9%. CONCLUSION: CKD stage 5 treated, due to its high incidence in Algeria, with large geographical variations, represents a major public health challenge. It mainly affects young people. Diabetes and high blood pressure represent the two main causes, encouraging prevention efforts to be focused on hypertensives and diabetics in high-risk wilayas.


Assuntos
Insuficiência Renal Crônica , Humanos , Argélia/epidemiologia , Masculino , Feminino , Incidência , Pessoa de Meia-Idade , Adulto , Insuficiência Renal Crônica/epidemiologia , Idoso , Estudos Prospectivos , Adulto Jovem , Adolescente , Estudos Longitudinais , Criança , Idoso de 80 Anos ou mais , Pré-Escolar , Terapia de Substituição Renal/estatística & dados numéricos , Hipertensão/epidemiologia
3.
Molecules ; 29(12)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38930959

RESUMO

We report the synthesis of two novel halogenated nitro-arylhimachalene derivatives: 2-bromo-3,5,5,9-tetramethyl-1-nitro-6,7,8,9-tetrahydro-5H-benzo[7]annulene (bromo-nitro-arylhimachalene) and 2-chloro-3,5,5,9-tetramethyl-1,4-dinitro-6,7,8,9-tetrahydro-5H-benzo[7]annulene (chloro-dinitro-arylhimachalene). These compounds were derived from arylhimachalene, an important sesquiterpene component of Atlas cedar essential oil, via a two-step halogenation and nitration process. Characterization was performed using 1H and 13C NMR spectrometry, complemented by X-ray structural analysis. Quantum chemical calculations employing density functional theory (DFT) with the Becke3-Lee-Yang-parr (B3LYP) functional and a 6-31++G(d,p) basis set were conducted. The optimized geometries of the synthesized compounds were consistent with X-ray structure data. Frontier molecular orbitals and molecular electrostatic potential (MEP) profiles were identified and discussed. DFT reactivity indices provided insights into the compounds' behaviors. Moreover, Hirshfeld surface and 2D fingerprint analyses revealed significant intermolecular interactions within the crystal structures, predominantly H-H and H-O contacts. Molecular docking studies demonstrate strong binding affinities of the synthesized compounds to the active site of protein 7B2W, suggesting potential therapeutic applications against various isolated smooth muscles and neurotransmitters.

4.
Nanomaterials (Basel) ; 14(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38869611

RESUMO

Ferroelectric, phase-change, and magnetic materials are considered promising candidates for advanced memory devices. Under the development dilemma of traditional silicon-based memory devices, ferroelectric materials stand out due to their unique polarization properties and diverse manufacturing techniques. On the occasion of the 100th anniversary of the birth of ferroelectricity, scandium-doped aluminum nitride, which is a different wurtzite structure, was reported to be ferroelectric with a larger coercive, remanent polarization, curie temperature, and a more stable ferroelectric phase. The inherent advantages have attracted widespread attention, promising better performance when used as data storage materials and better meeting the needs of the development of the information age. In this paper, we start from the characteristics and development history of ferroelectric materials, mainly focusing on the characteristics, preparation, and applications in memory devices of ferroelectric wurtzite AlScN. It compares and analyzes the unique advantages of AlScN-based memory devices, aiming to lay a theoretical foundation for the development of advanced memory devices in the future.

5.
Heliyon ; 10(10): e31219, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38807897

RESUMO

New calcium borovanadate glass containing manganese ions within the system x Mn2O3-(30-x) V2O5-50 B2O3-20 CaO has been elaborated* in this work using melt quench process. The primary objective of this research is to examine the influence of introducing Mn2O3 upon the various properties of the elaborated glass specimens including physical, thermal, structural, optical and magnetic properties. X-ray diffraction indicated that the samples prepared were amorphous. The variation in density and molar volume revealed that the structure of the glass matrix cross-links and becomes more compact with increasing Mn2O3 content, which is confirmed when the glass transition temperature is increased. Furthermore, in order to check the group constitution of our glasses, a structural study was carried out using infrared (FTIR) and Raman spectroscopy. The optical characteristics of our vitreous materials were analyzed by UV solid, and the results of the band gap energy and refractive index values revealed an enhancement of non-bridging oxygen atoms (NBOs) with rising Mn2O3 concentration, also suggests that manganese acts as a structure modifier. The low Urbach energy values are an indication that the structure of our glasses is stable and uniform. The magnetic investigation highlighted the presence of the predominant antiferromagnetic order in the glass samples studied, which becomes stronger with the incorporation of more manganese ions into the structure.

6.
Materials (Basel) ; 17(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38473501

RESUMO

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•- and holes h+ are the principal species responsible for the pollutant photodegradation.

7.
Dalton Trans ; 53(4): 1630-1639, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38167910

RESUMO

A novel phosphate containing barium, cobalt, and iron was synthesized in single-crystal and polycrystalline forms. Single crystal-based X-ray measurements revealed that it crystallizes in the monoclinic system with the P21/c space group. The structure is made up of linkages between FeO6 octahedra, CoO4 square planar units, CoO5 square pyramidal units, and PO4 tetrahedra through edges and/or vertices. The interconnection of these polyhedra leads to a three-dimensional framework with tunnels along the a-axis where the Ba2+ cations are located. The polycrystalline form was prepared via the sol-gel method and its XRD pattern was refined by the Le Bail method. Morphological and elemental mapping analyses of this phosphate were performed by scanning electron microscopy. In addition, infrared and Raman spectroscopy provided more insights into chemical bonding. The magnetic behavior was antiferromagnetic below TN ∼ 20 K. Optical measurements revealed a direct bandgap with an energy Eg of 2.83 eV.

8.
Future Med Chem ; 15(17): 1603-1619, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37772541

RESUMO

Background: This study aimed to develop novel isoxazoline-1,3,4-thiadiazole hybrids from (S)-verbenone for potential anticancer treatment, particularly focusing on cytotoxic and apoptotic effects in hormone-sensitive MCF-7 and triple-negative MDA-MB-231 breast cancer cells. Methods & results: (S)-verbenone was used to synthesize hybrids through 1,3-dipolar cycloaddition, followed by thorough characterization. The compounds were screened across cancer cell lines, showing significant anticancer effects. Compound 8b notably induced apoptosis via the caspase-3/7 pathway and cell cycle arrest, displaying noteworthy cytotoxicity against MCF-7 and MDA-MB-231 cells. Conclusion: These findings underscore the potential of (S)-verbenone isoxazoline-1,3,4-thiadiazole derivatives for breast cancer therapy due to their remarkable apoptotic activity. This study highlights a promising avenue for advancing breast cancer treatment using these derivatives, founded on (S)-verbenone, showcasing their distinct potential for inducing apoptosis.


Assuntos
Antineoplásicos , Neoplasias da Mama , Humanos , Feminino , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Apoptose , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Células MCF-7
9.
Nephrol Ther ; 19(1): 45-57, 2023 03 16.
Artigo em Francês | MEDLINE | ID: mdl-36919592

RESUMO

Introduction: Chronic kidney disease stage V, by its incidence and its prevalence which are constantly increasing in the world and in Algeria, the morbidity and mortality it generates, the high cost of its treatment, represents a major public health issue. Our objective is to describe the epidemiology of stage V chronic kidney disease treated in south-eastern Algeria. Patients and methods: In our regional, multicenter, prospective descriptive study, all patients with stage V chronic kidney disease, residing and treated in south-eastern Algeria between September 1, 2016, and December 31, 2017, were included and followed up until December 31, 2018. Results: Stage V chronic kidney disease is a frequent pathology in the region: 1934 patients were included. It mainly affects young people: the average age of patients was 50.17 ± 16.98 years, with a male predominance of 59.10%. High blood pressure and diabetes are the two main causes. The start of dialysis on a temporary catheter represents 81.5% of cases, the initial management requires emergency dialysis in 91.2% of cases. In total, 97.1% of chronic hemodialysis patients use an arteriove-nous fistula as a permanent vascular access. Conclusion: Our study population is younger than that of developed countries and has fewer comorbidities and disabilities but lower survival and high mortality. The developing national chronic kidney disease stage V registry is becoming an absolute necessity. It will allow to have a better knowledge of its epidemiology and the needs of its care in each region. It can contribute to improving the prevention and management of this disease.


Introduction: La maladie rénale chronique stade V, par son incidence et sa prévalence qui ne cessent d'augmenter en Algérie et dans le monde, la morbi-mortalité qu'elle engendre et le coût élevé de sa prise en charge, représente un enjeu majeur de santé publique. Notre objectif est de décrire l'épidémiologie de cette maladie, traitée dans le Sud-Est algérien. Patients et méthodes: Dans notre étude régionale multicentrique, prospective à visée descriptive, tous les patients atteints de maladie rénale chronique stade V, résidant et traités dans le Sud-Est algérien entre le 1er septembre 2016 et le 31 décembre 2017, ont été inclus et suivis jusqu'au 31 décembre 2018. Résultats: La maladie rénale chronique stade V est une pathologie fréquente dans la région : 1 934 patients ont été inclus. Elle touche principalement les jeunes : l'âge moyen des patients était de 50,17 ± 16,98 ans, avec une prédominance masculine à 59,10 %. L'hypertension artérielle et le diabète représentent les deux principales causes. Les démarrages de dialyse sur cathéter temporaire représentent 81,5 % des cas, la prise en charge initiale nécessite la dialyse en urgence dans 91,2 % des cas. Un total de 97,1 % des patients hémodialysés chroniques utilisent une fistule artérioveineuse comme abord vasculaire permanent. Conclusion: Notre population d'étude est plus jeune que celle des pays développés et présente un nombre moins important de comorbidités et de handicaps, mais une survie inférieure et une mortalité élevée. Le développement du registre national de la maladie rénale chronique stade V devient une nécessité absolue. Il va permettre une meilleure connaissance de son épidémiologie et des besoins pour sa prise en charge dans chaque région. Il peut contribuer à l'amélioration de la prévention et de la prise en charge de cette maladie.


Assuntos
Falência Renal Crônica , Humanos , Masculino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Feminino , Estudos Prospectivos , Argélia/epidemiologia , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Comorbidade
10.
Acta Crystallogr E Crystallogr Commun ; 79(Pt 2): 95-98, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36793405

RESUMO

The orthophosphate BaNi2Fe(PO4)3 has been synthesized by a solid-state reaction route and characterized by single-crystal X-ray diffraction and energy-dispersive X-ray spectroscopy. The crystal structure comprises (100) sheets made up of [Ni2O10] dimers that are linked to two PO4 tetra-hedra via common edges and vertices and of linear infinite [010] chains of corner-sharing [FeO6] octa-hedra and [PO4] tetra-hedra. The linkage of the sheets and chains into a framework is accomplished through common vertices of PO4 tetra-hedra and [FeO6] octa-hedra. The framework is perforated by channels in which positionally disordered Ba2+ cations are located.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA