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The present work analyses the transmittance and reflectance spectra of molybdenum trioxide film doped by silver nanoparticles as a function of angle of incidence and wavelength. As will be seen in this work, at values of angle of incidence below 40 degrees and with volume filling fraction below 1% also, some differences between the two effective medium theories are presented. First, the volume filling fraction is limited for low values (<1%) and second the scattering amplitude cannot be ignored for these cases. The novelty of this work is that the use of the effective medium model (refractive index) shows limitations in the description of the optical properties when it was applied to thin solid films.
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We report a simple and effective route to synthesize, disperse, exfoliate and process different molybdenum-based 2-dimensional (2D) materials. Starting from a reaction between ammonium molybdate and ammonium sulfide solutions, a powder consisting of a mixture between amorphous molybdenum oxide and sulfide is obtained. By tuning the atmosphere and the temperature, different compositions can be prepared by thermal treatment of this sample: heat treatments in ambient atmosphere produce MoO3 with different morphologies, controllable according to the chosen temperature. On the other hand, heat treatments in inert atmosphere produce mixtures between crystalline 2D MoS2 and MoO3. Further handling of these mixtures with acetonitrile separates the components due to the different solvent/solid affinities, with the layered MoS2 becoming homogeneously dispersed, and the MoO3 agglomerating as a solid easily removed by centrifugation. The resulting sulfide dispersions in acetonitrile present high stability, and they are constituted by exfoliated MoS2, which means that acetonitrile is a tri-functional agent, separating the sulfide/oxide mixture, exfoliating the sulfide and stabilizing the dispersion. The MoS2 dispersions were used to produce homogeneous, freestanding and transparent thin films through the liquid-liquid interfacial route, which were easily deposited over different substrates and characterized by different techniques.
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SUMMARY: Special features of nanoparticles have resulted in their widespread use. Small molybdenum trioxide (MoO 3) nanoparticles can translocate from the entry portals into the circulatory and lymphatic systems and ultimately to body tissues and organs depending on their composition and size. In this research, sixty Wistar rats weighting 180-250 g were divided into 6 groups (n=10) randomly: Group 1 (Control) did not receive any medicine. Group 2 (Sham) received intraperitoneal normal saline for 35 days on a daily basis. Groups 3, 4, 5 and 6 received 50, 100, 200, and 300 mg/kg MoO3, respectively, the same way in the sham group and at the same interval. At the end of the experiment, the rats were weighted again and anesthetised. Then blood samples were taken from their hearts to determine the serum levels of estrogen, progesterone, and gonadotropins. Their ovaries were removed and ovarian volume, follicular diameter, number of each follicle type, and oocyte volume were determined. Results indicated that MoO3 nanoparticles strongly reduced body and ovarian weights in the rats. Moreover, a significant decrease was observed in ovarian volume, the number of follicle types, oocyte volume and follicular diameter. The nanoparticles increased the number of atretic follicles via ovarian tissue structure. MoO3 nanoparticles decreased serum estrogen level and increased serum level of FSH that was associated with disruption in the regulation of progesterone and LH secretion. The findings showed that MoO3 nanoparticles could bear negative effects on ovarian structure and function.
RESUMEN: Las características específicas de las nanopartículas han dado lugar a su uso generalizado. Las pequeñas nanopartículas de trióxido de molibdeno (MoO3) pueden penetrar los sistemas circulatorios y linfáticos y, en última instancia, dependiendo de su composición y tamaño, también los tejidos y órganos del cuerpo. En esta investigación se dividieron 60 ratas Wistar con un peso de 180-250 g en 6 grupos (n = 10) aleatoriamente: el Grupo 1 (Control) no recibió ningún medicamento. El Grupo 2 (Sham) recibió solución salina normal intraperitoneal durante 35 días diariamente. Los grupos 3, 4, 5 y 6 recibieron 50, 100, 200 y 300 mg / kg de MoO3 respectivamente, de la misma manera en el grupo simulado, y en el mismo intervalo. Concluyendo el experimento, las ratas se pesaron nuevamente y fueron anestesiadas. Luego se tomaron muestras de sangre de los corazones para determinar los niveles séricos de estrógeno, progesterona y gonadotropinas. Se retiraron los ovarios y se determinó el volumen ovárico, el diámetro folicular, el número de cada tipo de folículo y el volumen de ovocitos. Los resultados indicaron que las nanopartículas de MoO3 redujeron significativamente los pesos corporal y ovárico en las ratas. Además, se observó una disminución importante en el volumen ovárico, el número de tipos de folículos, el volumen de ovocitos y el diámetro folicular. Las nanopartículas aumentaron el número de folículos auriculares a través de la estructura del tejido ovárico. Las nanopartículas de MoO 3 disminuyeron el nivel sérico de estrógeno y aumentaron el nivel sérico de FSH que se asoció con la interrupción en la regulación de la progesterona y la secreción de LH. Los hallazgos mostraron que las nanopartículas de MoO 3 podrían tener efectos negativos sobre la estructura y la función ovárica.