Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros











Intervalo de año de publicación
1.
J Phys Condens Matter ; 36(15)2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38171025

RESUMEN

The escalating research in the field of topology necessitates an understanding of the underlying rich physics behind the materials possessing unique features of non-trivial topology in both electronic and phononic states. Due to the interaction between electronic quasiparticles and spin degrees of freedom, the realization of magnetic topological materials has opened up a new frontier with unusual topological phases, however, these are rarely reported alongside phononic quasiparticle excitations. In this work, by first-principles calculations and symmetry analysis, the intermetallic ferromagnetic compounds MnGaGe and MnZnSb with the coexistence of exceptional topological features in the electronic and phononic states are proposed. These compounds host nodal surface onky=πplane in bulk Brillouin zone in the electronic and phononic spectra protected by the combination of time-reversal symmetry and nonsymmorphic two-fold screw-rotation symmetry. In the former case, a spin-polarized nodal surface is present in the majority and minority spin channels and found to be robust to ground-state magnetic polarization. The presence of nodal line features is analyzed in both the quasiparticle spectra, whose non-trivial nature is confirmed by the Berry phase calculation. The incorporation of spin-orbit coupling in the electron spectra introduces distinctive characteristics in the transport properties, facilitating the emergence of anomalous Hall conductivity through Berry curvature in both bulk and monolayer. Furthermore, the monolayer has been proposed as a two-terminal device model to investigate the quantum transport properties using the non-equilibrium Green's function approach. This superlative combination of observations and modeling sets the path for a greater level of insight into the behavior and aspects of topological materials at the atomic scale.

2.
J Appl Oral Sci ; 27: e20180348, 2019 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-31508790

RESUMEN

SOX2 is a transcription factor related to the maintenance of stem cells in a pluripotent state. Podoplanin is a type of transmembrane sialoglycoprotein, which plays an important role in tumor progression and metastasis. This study aims to determine association of SOX2 and podoplanin expression in the progression of oral squamous cell carcinomas and to elucidate the association between two proteins. Label="METHODOLOGY">The immunohistochemical expression of SOX2 and podoplanin were evaluated in 60 cases of primary oral squamous cell carcinomas. The correlation between the SOX2 and podoplanin expression and the clinicopathological features of the tumors and the patient outcomes were assessed. RESULTS The expression of SOX2 was seen in 38/60 (63%) of the cases and the expression for podoplanin was seen in 45/60 (75%) cases. There was a significant inverse correlation between the expression of SOX2 and podoplanin with the tumor grade (p=0.002 and p=0.017, respectively). There was a high expression of SOX2 in 9/13 cases that presented with disease free survival. Survival analysis showed that a high expression of SOX2 correlated positively (p=0.043) with the disease-free survival. There was a significant positive association between the pattern of SOX2 and podoplanin expression (p=0.002). CONCLUSION A high expression of SOX2 was associated with better disease-free survival. The expression of podoplanin was associated with the degree of differentiation of the tumors. Analysis of these biomarkers can aid in the prognosis and treatment of oral squamous cell carcinomas.


Asunto(s)
Carcinoma de Células Escamosas/patología , Glicoproteínas de Membrana/análisis , Neoplasias de la Boca/patología , Factores de Transcripción SOXB1/análisis , Adulto , Anciano , Biomarcadores de Tumor/análisis , Progresión de la Enfermedad , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Valores de Referencia , Estadísticas no Paramétricas , Factores de Tiempo
3.
J. appl. oral sci ; 27: e20180348, 2019. tab, graf
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1019972

RESUMEN

Abstract SOX2 is a transcription factor related to the maintenance of stem cells in a pluripotent state. Podoplanin is a type of transmembrane sialoglycoprotein, which plays an important role in tumor progression and metastasis. This study aims to determine association of SOX2 and podoplanin expression in the progression of oral squamous cell carcinomas and to elucidate the association between two proteins. Methodology: The immunohistochemical expression of SOX2 and podoplanin were evaluated in 60 cases of primary oral squamous cell carcinomas. The correlation between the SOX2 and podoplanin expression and the clinicopathological features of the tumors and the patient outcomes were assessed. Results: The expression of SOX2 was seen in 38/60 (63%) of the cases and the expression for podoplanin was seen in 45/60 (75%) cases. There was a significant inverse correlation between the expression of SOX2 and podoplanin with the tumor grade (p=0.002 and p=0.017, respectively). There was a high expression of SOX2 in 9/13 cases that presented with disease free survival. Survival analysis showed that a high expression of SOX2 correlated positively (p=0.043) with the disease-free survival. There was a significant positive association between the pattern of SOX2 and podoplanin expression (p=0.002). Conclusion: A high expression of SOX2 was associated with better disease-free survival. The expression of podoplanin was associated with the degree of differentiation of the tumors. Analysis of these biomarkers can aid in the prognosis and treatment of oral squamous cell carcinomas.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Neoplasias de la Boca/patología , Glicoproteínas de Membrana/análisis , Carcinoma de Células Escamosas/patología , Factores de Transcripción SOXB1/análisis , Valores de Referencia , Factores de Tiempo , Inmunohistoquímica , Biomarcadores de Tumor/análisis , Estadísticas no Paramétricas , Progresión de la Enfermedad , Clasificación del Tumor , Estadificación de Neoplasias
4.
Environ Sci Pollut Res Int ; 24(33): 26092-26110, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28942515

RESUMEN

The stable isotopes of δ18O, δ2H, and 87Sr/86Sr and dissolved major ions were used to assess spatial and seasonal water chemistry variability, chemical weathering, and hydrological cycle in the Pangani River Basin (PRB), Tanzania. Water in PRB was NaHCO3 type dominated by carbonate weathering with moderate total dissolved solids. Major ions varied greatly, increasing from upstream to downstream. In some stations, content of fluoride and sodium was higher than the recommended drinking water standards. Natural and anthropogenic factors contributed to the lowering rate of chemical weathering; the rate was lower than most of tropical rivers. The rate of weathering was higher in Precambrian than volcanic rocks. 87Sr/86Sr was lower than global average whereas concentration of strontium was higher than global average with mean annual flux of 0.13 × 106 mol year-1. Evaporation and altitude effects have caused enrichment of δ18O and δ2H in dry season and downstream of the river. Higher d-excess value than global average suggests that most of the stations were supplied by recycled moisture. Rainfall and groundwater were the major sources of surface flowing water in PRB; nevertheless, glacier from Mt. Kilimanjaro has insignificant contribution to the surface water. We recommend measures to be taken to reduce the level of fluoride and sodium before domestic use.


Asunto(s)
Monitoreo del Ambiente , Ríos/química , Estaciones del Año , Agua Subterránea/química , Lluvia , Isótopos de Estroncio/análisis , Tanzanía , Ciclo Hidrológico , Contaminantes Químicos del Agua/análisis
5.
J Colloid Interface Sci ; 457: 329-38, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26196716

RESUMEN

HYPOTHESIS: Biological synthesis of silver nanoparticles is a cost effective natural process where the phytochemicals specifically phenols, flavonoids and terpenoids present in the plant extracts act as capping and reducing agent. Due to their nano size regime the silver nanoparticles may directly bind to the DNA of the pathogenic bacterial strains leading to higher antimicrobial activity. EXPERIMENT: In the current study silver nanoparticles were synthesised using plant extracts from different origin Cucurbita maxima (petals), Moringa oleifera (leaves) and Acorus calamus (rhizome). The synthesised nanoparticles were characterized by UV-visible spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), field emission scanning electron microscopy (Fe-SEM) and Fourier transform infrared spectroscopy (FTIR). FINDING: Highly crystalline, roughly spherical and cuboidal silver nanoparticles of 30-70 nm in size were synthesised. The nanoparticles provided strong antimicrobial activity against pathogenic strains. The effect of the synthesised nanoparticles against A431 skin cancer cell line was tested for their toxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. The IC50 values of 82.39±3.1, 83.57±3.9 and 78.58±2.7 µg/ml were calculated for silver nanoparticles synthesised by C. maxima, M. oleifera and A. calamus respectively.


Asunto(s)
Antibacterianos/farmacología , Antineoplásicos Fitogénicos/biosíntesis , Antineoplásicos Fitogénicos/farmacología , Carcinoma de Células Escamosas/tratamiento farmacológico , Nanopartículas del Metal/química , Extractos Vegetales/química , Plata/farmacología , Acorus/química , Antibacterianos/biosíntesis , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Bacillus subtilis/efectos de los fármacos , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cucurbita/química , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Escherichia coli/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Moringa oleifera/química , Tamaño de la Partícula , Plata/química , Plata/metabolismo , Relación Estructura-Actividad , Propiedades de Superficie , Vibrio cholerae/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA