Nanostructured PbS-doped inorganic film synthesized by sol-gel route

IV-VI semiconductor quantum dots embedded into an inorganic matrix represent nanostructured composite materials with potential application in temperature sensor systems. This study explores the optical, structural, and morphological properties of a novel PbS quantum dots (QDs)- doped inorganic thin film belonging to the Al2O3 -SiO2 -P2O5 system. The film was synthesized by the sol-gel method, spin coating technique, starting from a precursor solution deposited on a glass substrate in a multilayer process, followed by drying of each deposited layer. Crystalline PbS QDs embedded in the inorganic vitreous host matrix formed a nanocomposite material. Specific investigations such as X-ray diffraction (XRD), optical absorbance in the ultraviolet (UV)-visible (Vis)-near infrared (NIR) domain, NIR luminescence, Raman spectroscopy, scanning electron microscopy– energy dispersive X-ray (SEM-EDX), and atomic force microscopy (AFM) were used to obtain a comprehensive characterization of the deposited film. The dimensions of the PbS nanocrystallite phase were corroborated by XRD, SEM-EDX, and AFM results. The luminescence band from 1400 nm follows the luminescence peak of the precursor solution and that of the dopant solution. The emission of the PbS-doped film in the NIR domain is a premise for potential application in temperature sensing systems.This study was funded by a grant of the Romanian National Authority for Scientific Research and Innovation, CCCDI–UEFISCDI, project ERANET-MANUNET-TEMSENSOPT, MNET20/ NMCS3732, within PNCDI III, contract 213/02.12.2020; Ministry of Research, Innovation and Digitalization (MRID), Core Program, contracts no. 16N/2019, 18N/2019 and 21N/2019; MRID through Program I—Development of the National R & D System, Subprogram 1.2–Institutional Performance– Projects for Excellence Financing in RDI, contracts no. 13PFE/2021, 18PFE/2021 and 35PFE/2021; CCCDI-UEFISCDI project PN-III-P2-2.1-PED-2021-2541. Support from the Public University of Navarre for Research Groups is also acknowledged

Toxicity assessment of long-term exposure to non-thermal plasma activated water in mice

Non-thermal plasma activated water (PAW) has recently emerged as a powerful antimicrobial agent. Despite numerous potential bio-medical applications, studies concerning toxicity in live animals, especially after long-term exposure, are scarce. Our study aimed to assess the effects of long-term watering with PAWon the health of CD1 mice. PAWwas prepared from distilled water with a GlidArc reactor according to a previously published protocol. The pH was 2.78. The mice received PAW(experimental group) or tap water (control group) daily for 90 days as the sole water source. After 90 days, the following investigations were performed on the euthanatized animals: gross necropsy, teeth mineral composition, histopathology, immunohistochemistry, hematology, blood biochemistry, methemoglobin level and cytokine profile. Mice tolerated PAWvery well and no adverse effects were observed during the entire period of the experiment. Histopathological examination of the organs and tissues did not reveal any structural changes. Moreover, the expression of proliferation markers PCNA and Ki67 has not been identified in the epithelium of the upper digestive tract, indicating the absence of any pre- or neoplastic transformations. The results of our study demonstrated that long-term exposure to PAWcaused no toxic effects and could be used as oral antiseptic solution in dental medicine

Claves para trabajar la entonación irónica con alumnos de ELE

El objetivo de este trabajo es hacer una propuesta didáctica que ayude a percibir/ producir la entonación irónica a los estudiantes de español como lengua extranjera (ELE). Este trabajo se centrará, en los aspectos fónicos, y especialmente en los entonativos (Lahoz Bengoechea, 2012; Padilla García, 2015), pero tendremos en cuenta también otros ingredientes del fenómeno, como el componente pragmático y el componente cultural. Tomando como punto de partida las indicaciones del MCER (2002) y del Plan Curricular del Instituto Cervantes (2007), pensamos que la ironía es un fenómeno comunicativo que, aun siendo compartido por muchas culturas, puede resultar difícil de manejar por los aprendientes de español. Teniendo en cuenta lo anterior, nuestra propuesta didáctica presentará algunas claves de reconocimiento de la ironía con el propósito de mostrar a los alumnos las particularidades de la entonación irónica, relacionándola, además, con las unidades fraseológicas y con otros indicadores lingüísticos (GRIALE, 2011)

Annealing-Induced High Ordering and Coercivity in Novel L10 CoPt-Based Nanocomposite Magnets

A novel class of quaternary intermetallic alloys based on CoPt is investigated in view of their interesting magnetic properties induced by the presence of hard magnetic L10 phase. A Co48Pt28Ag6B18 alloy has been prepared by rapid solidification from the melt and subjected to various isothermal annealing procedures. The structure and magnetism of both as-cast and annealed samples as well as the phase evolution with temperature are investigated by means of thermal analysis, X-ray, and selected area electron diffraction, scanning and high-resolution electron microscopy, and magnetic measurements. The X-ray diffraction (XRD) analysis shows that both the as-cast alloy and the sample annealed at 400 °C (673 K) have a nanocrystalline structure where fcc CoPt phase predominates. Annealing at 473 °C promotes the formation of L10 phase triggered by the disorder-order phase transformation as documented in the differential scanning calorimetry results. The sample annealed at 670 °C (943 K) shows full formation of L10 CoPt as revealed by XRD. Magnetic measurements showed coercivity values ten times increased compared to the as-cast state. This confirms the full formation of L10 CoPt in the annealed samples. Moreover, detailed atomic resolution HREM images and SAED patterns show the occurrence of the rarely seen (003) superlattice peaks, which translated into a high ordering of the L10 CoPt superlattice. Such results spur more interest in finding novel classes of nanocomposite magnets based on L10 phase

Surface Characterization of Modified Electrodes Based on 4-(Azulen-1-yl)-2,6-bis((E)-2-(thiophen-2-yl)vinyl)pyridine

Sensitive electrodes based on complexing azulene polymer films were prepared by electrochemical deposition on glassy carbon electrodes. The characterization of 4-(azulen-1-yl)-2,6-bis((E)-2-(thiophen-2-yl)vinyl)pyridine (M) and its polymerization were performed by voltammetric methods on glassy carbon disk working electrodes in millimolar solutions of acetonitrile in the presence of 0.1 M tetrabutylammonium perchlorate (TBAP). The films containing complexing (thiophen-2-yl)vinyl symmetrically substituted pyridine fragments were deposited either by scanning or by controlled potential electrolysis (CPE). Investigation and morphological characterization of samples by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Atomic Force Microscopy (AFM), Fourier Transform IR Spectroscopy (FTIR), and fluorescence showed particular features of the CMEs obtained at variable potentials and charges and suggested the conservation the complexing units in the films. The characterization methods for chemically modified electrodes (CMEs) were chosen depending on the desired uses of this monomer for heavy metal sensors or optical applications, respectively

STUDY OF SURFACE PHENOMENA IN MATERIALS OF PROSTHETIC RESTORATION

As a direct consequence of their application domain – the oral cavity – dental materials are subjected to the corosive action of saliva, being surrounded by microorganisms, fluids and alimentary rests, which modify their surface characteristics. Concerns on the quality of the dental materials explain the numeorus interdisciplinary studies, characterized by a close relation among various scientific domains (physics, chemistry, biology, science of biomaterials), techniques also applied in clinical stomatology. Analysis of the saliva–dental materials interface made use of ceramic surfaces, composites and artificial saliva, permitting to determine the main surface parameters of the materials of prosthetic restoration, calculated with some physical models, starting from measurements of the contact angle: surface energy, its polar and dispersive components, surface rugosity, adhesion mechanic work. All composites showed low values of the adhesion mechanic work, the conclusion being that they are much more hydrophobic than the ceramic materials. Such a property is especially important from an aesthetic perspective, as the hydrophobic materials have a better colour stability in time

Surface Characteristics of High Translucent Multilayered Dental Zirconia Related to Aging

(1) Background: The purpose of this study was to evaluate the differences in terms of surface characteristics (roughness, topography, microhardness) among layers for multi-layered high translucent and super-high translucent zirconia and the influence of finishing and aging on surface characteristics and microstructure. (2) Methods: Three types of translucent multilayer zirconia were evaluated: STML (4Y-TZP); IPS e.maxZirCAD CEREC/in Lab MT Multi (4Y-TZP + 5Y-TZP); CeramillZolidfx ML (5Y-TZP). Ninety-six plate-shaped samples (32 for a material), 16 mm × 14 mm × 1 mm size, were cut with a precision disc, polished on both sides with sand papers and sintered respecting the manufacturer’s protocol. Half of the specimens (16) were finished by polishing and the other half by glazing and then equally divided into one control group and one group subject to aging by autoclaving (1 h, 134 °C, 0.2 MPa), resulting in four groups of eight samples, for each zirconia. The specimens were evaluated in three areas: cervical, medium, incisal-of each glazed or polished surface, before and after aging. Tests were performed to determine the surface roughness using a profilometer; the surface topography by an atomic force microscope (AFM) and a scanning electron microscope (SEM). Microhardness was recorded using a microhardness tester. Statistical analyses were performed using two-way ANOVA test, unpaired sample t-Test, paired sample t-Test (α = 0.05) and Pearson’s correlation. (3) Results: Before and after autoclaving, for glazed samples significance (p p > 0.05) were reported between the three areas, on glazed or polished surfaces of a material. Although, after aging an increase in surface roughness was observed both on glazed and polished samples, statistical differences were found for STML (p 0.05). No significant differences (p> 0.05) concerning microhardness among the same areas, on glazed and polished surfaces, recorded before and after aging, except CeramillZolidfx ML glazed samples. (4) Conclusions: For tested zirconia materials no significant differences among layers were registered regarding surface characteristics. Surface treatment (glazing or polishing) has a significant impact on surface roughness and microhardness. Both before and after aging, the surface roughness values for the glazed samples were higher than for those polished. The super translucent 4Y-TZP material was more affected by aging compared to the super-high translucent 5Y-TZP material. The combined material revealed similarities for each layer corresponding to the microstructure

Nanostructured PbS-Doped Inorganic Film Synthesized by Sol-Gel Route

IV-VI semiconductor quantum dots embedded into an inorganic matrix represent nanostructured composite materials with potential application in temperature sensor systems. This study explores the optical, structural, and morphological properties of a novel PbS quantum dots (QDs)-doped inorganic thin film belonging to the Al2O3-SiO2-P2O5 system. The film was synthesized by the sol-gel method, spin coating technique, starting from a precursor solution deposited on a glass substrate in a multilayer process, followed by drying of each deposited layer. Crystalline PbS QDs embedded in the inorganic vitreous host matrix formed a nanocomposite material. Specific investigations such as X-ray diffraction (XRD), optical absorbance in the ultraviolet (UV)-visible (Vis)-near infrared (NIR) domain, NIR luminescence, Raman spectroscopy, scanning electron microscopy–energy dispersive X-ray (SEM-EDX), and atomic force microscopy (AFM) were used to obtain a comprehensive characterization of the deposited film. The dimensions of the PbS nanocrystallite phase were corroborated by XRD, SEM-EDX, and AFM results. The luminescence band from 1400 nm follows the luminescence peak of the precursor solution and that of the dopant solution. The emission of the PbS-doped film in the NIR domain is a premise for potential application in temperature sensing systems

Phospholamban p.Leu39* Cardiomyopathy Compared with Other Sarcomeric Cardiomyopathies: Age-Matched Patient Cohorts and Literature Review

Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic disorder, most often caused by sarcomeric gene mutations, with a small proportion due to variants in non-sarcomeric loci. Phospholamban (PLN) is a phosphoprotein associated with the cardiac sarcoplasmic reticulum, a major determinant of cardiac contractility and relaxation. We conducted a retrospective study to determine the prevalence, phenotypical spectrum and clinical course of patients carrying the PLN p.Leu39* variant. A cohort including 11 PLN patients was identified among all patients with HCM (9/189, 4.8%) and DCM (2/62, 3.2%) who underwent genetic testing from two tertiary centers and five more were detected through cascade screening. Complete phenotyping was performed. PLN p.Leu39* variant-driven cardiomyopathy presented mostly as hypertrophic, with frequent progression to end-stage dilated HCM. We proceeded to compare these results to a similar analysis of a control cohort consisting of age-matched individuals that inherited pathogenic or likely pathogenic variants in common sarcomeric genes (MYBPC3/MYH7). Overall, the clinical characteristics and examination findings of patients carrying PLN p.Leu39* were not different from patients with cardiomyopathy related to sarcomeric mutations except for the presence of pathological Q waves and the incidence of non-sustained ventricular arrhythmias, which were higher in PLN patients than in those with MYBPC3/MYH7-related diseases