266 research outputs found
Thermal Behavior of Nanoclay Reinforced Ultraviolet Curable Epoxy Acrylate
This study related to preparation of UV curable epoxy nanoclay nanocomposite and investigation on
mechanical and thermal properties of their thin films. For achieving this UV-curable epoxy dimethacrylate
was synthesized by epoxy resin (EPIKOTE 828), methacrylic acid, triphenylphosphine (PPh3) as catalyst
and para-methoxy phenol (PMP) as inhibitor at 80 ºC for 2 hours (yield 99%). Formulation of UV curable
resin was achieved by 5% w/w benzophenone and N, N dimethylaminoethyl methacrylate. The resin was
reinforced by using 1-5% w/w modified nanoclay in total formulation. Synthesized resin was characterized
by FTIR spectroscopy and thermal behaviors of nanocomposites were evaluated by TGA and DSC analysis.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521
Tensile strength and impact strength of color modified acrylic resin reinforced with titanium dioxide nanoparticles
Poor mechanical properties are among the main limitations of acrylic resins. Addition of titanium dioxide (TiO2) nanoparticles to acrylic resin has been shown to improve its mechanical properties with an adverse effect on its color. Thus, this study sought to assess the tensile and impact strength of a color modified heat cure acrylic resin reinforced with TiO2 nanoparticles. In this in vitroexperimental study, 1wt% TiO2 nanoparticles were added to SR Triplex Hot heat-cure acrylic resin powder and mixed. Pigments and color fibers were also added and 18 samples were fabricated of this paste for tensile and impact strength testing (n=9) according to ISO5271. Eighteen control samples were also fabricated from the acrylic powder without any modification. Independent t-test was used for data analysis (P< 0.05). The mean tensile strength of the reinforced group was found to be significantly higher (difference of 11 MPa) than that of the control group (P=0.001). The mean impact strength of the reinforced group was 7 MPa higher than that of the control group and this difference was statistically significant as well (P=0.001). The color modified acrylic resin reinforced with 1wt% TiO2 showed significantly higher tensile and impact strength compared to the conventional acrylic resin. Thus, TiO2 nanoparticles may be incorporated into color-modified acrylic resin powder to enhance its tensile and impact strength, given that they have no adverse effect on other properties
Prediction of Post-Operative Renal and Pulmonary Complication Using Transformers
Postoperative complications pose a significant challenge in the healthcare
industry, resulting in elevated healthcare expenses and prolonged hospital
stays, and in rare instances, patient mortality. To improve patient outcomes
and reduce healthcare costs, healthcare providers rely on various perioperative
risk scores to guide clinical decisions and prioritize care. In recent years,
machine learning techniques have shown promise in predicting postoperative
complications and fatality, with deep learning models achieving remarkable
success in healthcare applications. However, research on the application of
deep learning models to intra-operative anesthesia management data is limited.
In this paper, we evaluate the performance of transformer-based models in
predicting postoperative acute renal failure, postoperative pulmonary
complications, and postoperative in-hospital mortality. We compare our method's
performance with state-of-the-art tabular data prediction models, including
gradient boosting trees and sequential attention models, on a clinical dataset.
Our results demonstrate that transformer-based models can achieve superior
performance in predicting postoperative complications and outperform
traditional machine learning models. This work highlights the potential of deep
learning techniques, specifically transformer-based models, in revolutionizing
the healthcare industry's approach to postoperative care
Optimización de parámetros de deposición de capas delgadas de cobre utilizando diseño de experimentos
Una investigación, denominada Optimización de parámetros de deposición de capas delgadas de cobre utilizando diseño de experimentos y desarrollada en el Centro de Investigación en Ciencia e Ingeniería de Materiales (CICIMA), de la Universidad de Costa Rica, tuvo como objetivo poder encontrar la relación de los parámetros del magnetrón (presión, potencia y tiempo) con el grosor de formación de las capas delgadas de cobre. Se utilizó el método estadístico de 2K (donde K es el número de parámetros por utilizar en la investigación) y se encontró el númeroposible de combinaciones con los tres parámetros del magnetrón, para luego llevar a cabo las deposiciones y posteriormente las mediciones en el microscopio de fuerza atómica (AFM)
La inteligencia competitiva y el desarrollo de una ventaja competitiva sostenible
Privatization, partial tariff liberalization and entrance of foreign insurance companies in Iranian market pose serious challenges to domestic insurance companies. This paper discusses competitive intelligence as a means of gaining competitive advantage for insurance companies and seeks to study its effects on creation of sustainable competitive advantage. A sample of 123 middle and senior managers working in Iran Insurance Company in Tehran were surveyed. Data were collected via questionnaire and analyzed using Structural Equation Model (SEM) in PLS software. Results showed that competitive intelligence had a positive effect on creation of competitive advantage based on two sets of process and contextual factors, with the former exerting greater effect in this regard. It was concluded that companies were required to gain competitive advantage by establishing a strategic unit to collect, analyze and share intelligent information derived from internal and external environmentLa privatización, la liberalización parcial de los aranceles y la entrada de empresas extranjeras de seguros en el mercado iraní plantea importantes desafíos para las empresas locales de seguros. Este artículo discute el caso de la inteligencia competitiva como un medio para ganar ventaja competitiva para las empresas de seguros y busca estudiar los efectos en la creación de ventaja competitiva sostenible. Se encuestó una muestra de 123 gerentes en posiciones medias y altas de la Iran Insurance Company en Teherán. La recolección de los datos se realizó a través de un cuestionario y fue analizada con el modelo de ecuaciones estructurales (SEM, por sus siglas en inglés) en el software PLS. Los resultados mostraron que la inteligencia competitiva tuvo un efecto positivo en la creación de ventaja competitiva basada en dos conjuntos de factores de procesos y contextuales, donde el primero tuvo en efecto mayor en este aspecto. Se concluyó que las compañías requirieron obtener ventaja competitiva al establecer una unidad estratégica para recolectar, analizar y compartir información inteligente derivada del ambiente interno y extern
Quantitative Analysis of Skin Erythema Due to Laser Hair Removal: A Diffusion Optical Spectroscopy Analysis
Introduction: Laser hair removal needs an accurate understanding of tissue structure and chromophores content in order to optimize the selection of laser irradiation parameters. None of the optimized laser therapy might lead to side effects in skin tissue such as severe erythema, burn, scar etc. Therefore, guidance by a noninvasive real-time diagnostic method like optical spectroscopy technique is beneficial. The purpose of this survey is to analysis the skin hemoglobin spectrum quantitatively before and after hair removal laser irradiation to minimize the side effects of the procedure.Methods: To carry out a spectroscopy study, a halogen-tungsten light source was used in the wavelength region of 400-700 nm on an ocean optic device. The measurements were made on the facial area under identical conditions. Total 19 volunteers for laser hair removal by gentle laser Candela, ranging 14- 49 years old, were included in the study. A total of 18 spectra were taken from each person, 9 spectra before hair removal as a reference and 9 subsequent spectra. Colorimetry was done for all acquired before and after spectrums using Origin software (version 8.6). Then, the erythema index derived for each spectrum. Statistical analysis of correlation and normalization in colorimetry data were done using data analysis by SPSS (version 16).Results: Spectra analysis, before and after optical reflectance spectrums in laser hair removal procedure, revealed the subpeak derivation, and concentration on special visible wavelength 510-610 nm. We studied the changes of skin chromophores absorption. The derived erythema index [E] and colorimetry parameters a*, b*, l* were compared and correlated statistically. There was a statistically considerable direct linear correlation between a* and E while inverse linear correlation was observed for l* and E and no correlation for b* and E.Conclusion: Diffuse reflectance spectroscopy showed its potency as an accurate, noninvasive real-time as complementary method for laser treatment to detect erythema as a complication of the method, in order to optimize the parameters based on the tissue characteristics in various candidates
Quantitative Autofluorescence Imaging of A375 Human Melanoma Cell Samples: A Pilot Study
Introduction: Skin cancer is one of the most common types of malignancy worldwide. Human skin naturally contains several endogenous fluorophores, as potential sources that can emit inherent fluorescence, called intrinsic autofluorescence (AF). The melanin endogenous fluorophore in the basal cell layer of the epidermis seems to have a strong autofluorescence signal among other ones in the skin. This pilot study aimed to investigate the feasibility of the detection of autofluorescence signals in the A375 human melanoma cell line in the cell culture stage using the FluoVision optical imaging system.Methods: The human skin melanoma cell line (A375) donated as a gift from Switzerland (University Hospital Basel) was cultured. For the imaging of the A375 human melanoma cell sample in this pilot study, the FluoVision optical imaging device (Tajhiz Afarinan Noori Parseh Co) was applied. The proposed clustering image processing code was developed based on the K-mean segmentation method, using MATLAB software (version 16).Results: The quantification of color pixels in the color bar along with the intensity score of the autofluorescence signal ranged between 0 and 70 was written in the image processing code execution and a threshold higher than 40%, proportional to the ratio of autofluorescent cells. The percentage of the signal of A375 autofluorescent melanoma cells in the 3 studied cell samples was calculated as 3.11%±0.6.Conclusion: This imaging method has the advantage of no need for fluorophore labels over the existing fluorescence imaging methods, and it can be regarded as one of the important choices of label-free imaging for this A375 melanoma cell line containing the intrinsic endogenous fluorophore in cell studies.
DOI: 10.34172/jlms.2021.0
The Immediate Pain-Relieving Effects of Non-Thermal CO2 Laser Therapy on Genital Ulcers of Behcet’s Disease: A Case Report
Behçet’s disease (BD) is a chronic, relapsing, systemic vasculitis of unknown etiology. Oral and genital aphthous ulcers are considered as the hallmarks of BD. The genital ulcers of BD may be extremely painful and often refractory to multiple treatments. In addition, they exert a negative impact on the patient’s quality of life. Some investigations have demonstrated the significant and immediate pain-relieving effects of NTCLT (non-thermal CO2 laser therapy) on some oral lesions with no visible adverse effects. In this paper, we report a case of BD whose painful genital ulcers were irradiated with NTCLT and the patient’s pain caused by the ulcers relieved immediately and significantly with no visible complications
Synthesis, characterization and study on thermal stability, mechanical properties and thermal conductivity of UV-curable urethane acrylate-Clay (MMT) nanocomposites
AbstractIn this study, at first UV-curable urethane acrylate-Clay nanocomposites (UA/Clay) were synthesized, then the effects of nanoparticles on the thermal stability, mechanical properties and thermal conductivity of UA nanocomposites were investigated. FT-IR analysis confirmed the molecular structure of urethane acrylate oligomer. SEM images showed that the nanoparticles were dispersed uniformly in the polymer matrix. The thermal stability of samples were investigated by thermogravimetric analysis (DTG). DMTA study indicated significant improvement in the mechanical properties and thermal behavior of nanocomposites by adding a certain amount of Clay (3, 5 wt%) nanoparticles to polymer-matrix. Moreover, infrared thermography analysis showed that thermal conductivity of the nanocomposites rose as filler content increased (3, 5 wt%)
Relieving Pain in Oral Lesions of Pemphigus Vulgaris Using the Non-ablative, Non-thermal, CO2 Laser Therapy (NTCLT): Preliminary Results of a Novel Approach
Introduction: Pemphigus vulgaris (PV) is a chronic, serious autoimmune mucocutaneous bullous disease. Oral lesions in PV may be extremely painful. This pain may adversely affect the patients’ oral intake and quality of life. This before-after clinical trial was designed to assess the pain relieving effects of single session of non-ablative, non-thermal CO2 laser therapy (NTCLT) in oral lesions of PV.Methods: Fifty painful oral lesions of fourteen patients with PV were illuminated by CO2 laser (power: 1 W, scanning the lesions with rapid circular motion of the handpiece) passing through a thick layer of transparent gel with high water content. The pain severity of the oral lesions was reported by the patients up to the fourth postoperative day. They were also asked to continue their existing systemic treatment during the course of this study as a precondition for the participation.Results: The severity of contact and non-stimulate (non-contact) pain declined immediately and significantly after NTCLT (P < 0.001). The pain relieving effect was sustained during the four successive days of follow-up. The procedure was pain free and no kind of analgesics was required. Following NTCLT, there were no visible thermal complications such as destruction, ablation or irritation of the oral lesions.Conclusion: The results of the trial proposed that single session of NTCLT could immediately and significantly relieve pain in oral lesions of PV, without any visible thermal complications
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