scholarly journals Consolidation and Adhesion of Pictorial Layers on a Stone Substrate. The Study Case of the Virgin with the Child from Palazzo Madama, in Turin

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 624
Author(s):  
Anita Negri ◽  
Marco Nervo ◽  
Stefania Di Marcello ◽  
Daniele Castelli
Keyword(s):  
Laboratory Tests ◽  
Scientific Literature ◽  
Acrylic Resin ◽  
Small Particle Size ◽  
Stone Surface ◽  
Low Viscosity ◽  
Colorimetric Test ◽  
Study Case ◽  
Nw Italy ◽  
Suitable Product

The study and the restoration of a polychrome limestone statue representing the Virgin with the Child, from Palazzo Madama in Turin (NW Italy) offered interesting conservation issue related to the polychromy on stone. To preserve the pictorial layers, it was necessary to re-establish the cohesion among the different polychrome layers (original and repainted) and the adhesion between polychrome film and the stone substrate. Particular attention was paid to the choice of intervention materials, selected through a preliminary survey of the scientific literature, and then verified by laboratory tests (tape test, colorimetric test, and permeability test). The most suitable product should to be able to penetrate porosity, to consolidate the layers, to make the pictorial film adhere with the stone surface, and to avoid changes in the colour and in the permeability. The material chosen also had to ensure compatibility with the cleaning method that could only take place after the consolidation of the pictorial layers due to the problematic state of preservation. A range of products, characterised by their small particle size and low viscosity, was tested, and a micro-acrylic resin was selected and successfully applied on the polychromy of the sculpture.

scholarly journals Preparation and Characterisation of Poly(methyl metacrylate)-Titanium Dioxide Nanocomposites for Denture Bases

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2655
Author(s):  
Mariusz Cierech ◽  
Marcin Szerszeń ◽  
Jacek Wojnarowicz ◽  
Witold Łojkowski ◽  
Jolanta Kostrzewa-Janicka ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Colour Change ◽  
Acrylic Resin ◽  
Considerable Change ◽  
Dental Prosthesis ◽  
Tio2 Nps ◽  
Eds Analysis ◽  
Colorimetric Test ◽  
Average Size

Introduction of titanium dioxide nanoparticles (TiO2 NPs) to poly(methyl methacrylate) (PMMA) aims to improve the mechanical, microbiological and tribological properties of dental prosthesis bases. The aim of the research was to assess the polymerisation time and the change in the colour of the new biomaterial. Samples with the 1 wt% and 2 wt% content of TiO2 additionally modified by ultrasounds were created. The effectiveness of ultrasounds was assessed by comparing the average size of conglomerates in a liquid acrylic resin monomer by means of a dynamic light scattering (DLS) analysis. The biomaterial structure was assessed by the energy-dispersive X-ray spectroscopy (EDS) analysis. The colour change was analysed by means of a colorimetric test and provided in the CIE (Commission internationale de l’éclairage) L*a*b* and RGB (Red Green Blue) colour palette. It was observed during the DLS test that the ultrasonic homogenisation process caused an increase in the suspension heterogeneity. The EDS analysis confirmed the presence of nanoparticles sized below 100 nm, which constitutes a ground for calling the new biomaterial a nanocomposite. The addition of TiO2 NPs as well as the ultrasounds result in the reduction of the average PMMA polymerisation time. The obtained data reveal that the addition of both 1 wt% and 2 wt% causes a considerable change in the PMMA colour: its whitening. To summarise, the reduced polymerisation time of the new biomaterial fully enables performance of standard procedures related to creation of dental prosthesis bases. Due to the considerable change in the colour, the clinical application is limited to performance of repairs or relining of the prosthesis, where the new material is located in an unaesthetic zone.

In silico ADME/Pharmacokinetic and Target Prediction Studies of Ethambutol as Drug Molecule

2022 ◽  
Vol 22 ◽  
Author(s):  
Arnav Ajinkya Joshi ◽  
Sakshi V. Khairnar ◽  
Hemchandra K. Chaudhari
Keyword(s):  
Experimental Data ◽  
Laboratory Tests ◽  
Scientific Literature ◽  
Target Prediction ◽  
Drug Molecule ◽  
Active Molecule ◽  
Online Tool ◽  
Testing Conditions ◽  
Drug Molecules ◽  
Adme Properties

Background: The conventional approach for the development of any pharmaceutically active molecule is a time-consuming and costly process because the synthesis is followed by laboratory tests which are then followed by long clinical trials. Hence a faster approach is desired. This article discusses Ethambutol, a frontline anti-tubercular drug that has its properties predicted by the SwissADME tool and the results would be compared with the findings published in the literature. Objective: The main objective is to study the predicted and experimental ADME properties, compare them. As well as study the predicted targets and understand the use of SwissADME for designing other drug molecules. Method: SwissADME, an online tool for ADME prediction was used along with Swiss Target Prediction to understand the targets of the drug. Further, experimental data was obtained from the available scientific literature. Results: We found certain similarities between the predicted and experimental data. However, there were some variations, depending on the testing conditions. The results are interpreted ahead in the article. Conclusion: Ethambutol’s predicted ADME properties are discussed and as per findings from results, it can be concluded that other drug molecules can be similarly predicted using these tools. Also, based on predicted data we can reformulate and prepare some different preparations of the drug.

The Porosities or Voids Included in Composite Resin Restorations

2013 ◽  
Vol 833 ◽  
pp. 349-354
Author(s):  
Xin Yi Zhao ◽  
Wu Zhang ◽  
Sean Lee ◽  
Clyde Roggenkamp
Keyword(s):  
Resin Composite ◽  
In Vitro Study ◽  
Acrylic Resin ◽  
Injection Technique ◽  
Composite Restorations ◽  
Low Viscosity ◽  
Insertion Techniques ◽  
Composite Resin Restorations ◽  
Composite Restoration

Purpose: The aim of this in vitro study was to investigate effects of consistency of resin composite and insertion techniques on the formation of porosity or inclusion of air bubbles in resin composite restorations. Materials and Methods: Three resin composites (Tetric Ceram HB, Tetric EvoCeram and Prodigy) were selected to represent high, intermediate and low viscosity, respectively. Simulated Class I cavities prepared in acrylic resin blocks were restored with one of the composites using both hand-instrument insertion and injection insertion techniques. The restorations were sectioned longitudinally and microscopically examined for the presence of porosity. Results: The materials of low (Prodigy) and high Tetric Ceram HB) viscosity exhibited a significantly less porosity than the material of a mediate viscosity. The porosities of Prodigy and Tetric Ceram HB restorations were comparable regardless of the insertion technique. Tetric EvoCeram restorations inserted by the hand technique contained more porous inclusions than those inserted using the injection technique. Conclusion: Porosities inside resin composite restorations apparently arose during the filling process, and the consistency of resin composite influenced the porosity formation of the composite restoration. Injection insertion was not found necessary to reduce porosities.

scholarly journals Leaf compressions from the Late Miocene sections of NW Italy: research on an efficient, easy and quick consolidation treatment

2016 ◽  
Vol 72 (3-4) ◽  
pp. 172-182 ◽  
Author(s):  
Dafne Cimino ◽  
Oscar Chiantore ◽  
Edoardo Martinetto ◽  
Pero Damarco ◽  
Tommaso Poli
Keyword(s):  
Late Miocene ◽  
Natural Science ◽  
Acrylic Resin ◽  
Northern Italy ◽  
Science Museums ◽  
Consolidation Treatment ◽  
Polyurethane Resin ◽  
Fossil Leaves ◽  
The Matrix ◽  
Nw Italy

Compressions of fossil leaves on marl blocks soaked with water are tricky palaeobotanic findings to deal with. In fact, this peculiarity makes the findings exposed to serious degradation: the evaporation of water causes shrinkage of the matrix and the leaf leading to fragmentation, delamination and exfoliation of the fossil, until its final disappearance. The aim of this research was to identify a consolidation method which satisfies museum needs and can be utilised for all conditions of hydration of the object. Following a survey of several natural science museums in Northern Italy, Paraloid™ B72 and PEG4000 along with other resins never previously used on this kind of fossil were tested. At the end of the research, two products gave adequate or good results, preserving the leaf from further degradation whatever the hydration condition of the object: the acrylic resin Paraloid™ B72 and a polyurethane resin.

scholarly journals The effect of isotretinoin on triglycerides and liver aminotransferases

2012 ◽  
Vol 87 (3) ◽  
pp. 382-387 ◽  
Author(s):  
Andreia Salezze Vieira ◽  
Vanessa Beijamini ◽  
Ana Carolina Melchiors
Keyword(s):  
Longitudinal Study ◽  
Adverse Events ◽  
Alanine Aminotransferase ◽  
Laboratory Tests ◽  
Scientific Literature ◽  
Secondary Analysis ◽  
Lipid Levels ◽  
Normal Range ◽  
Oral Isotretinoin ◽  
The Mean

BACKGROUND: Isotretinoin has been used to treat the most severe cases of acne; however, it may provoke adverse events in mucocutaneous and hepatic tissues, lead to alterations in lipid levels and cause teratogenicity. OBJECTIVE: The objective of this study was to evaluate the profile of changes in alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride levels in patients who had been treated with oral isotretinoin dispensed by the São Mateus/ES pharmacy for special drugs. METHODS: A retrospective, observational, longitudinal study was conducted by carrying out a secondary analysis of each patient's data. RESULTS: Of the 130 patients who received isotretinoin between January and December 2009, only 70 were actually treated for 3 months or more and handed in the results of their laboratory tests. Of these 70 patients, 39 (55.7%) were female. The mean age of the women (23.9 years) was higher than the mean age of the men (20.1 years). There was a statistically significant increase in the levels of triglycerides (87.01 ± 48.25 versus 105.32 ± 48.76 mg/dL), AST (20.44 ± 6.26 versus 24.38 ± 11.92 U/L) and ALT (18.24 ± 8.31 versus 23.34 ± 20.03 U/L) performed prior to and 3 months or more after oral isotretinoin treatment. After treatment with oral isotretinoin, triglyceride levels had increased beyond the normal range in 11% of the patients, while 8.6% had elevated AST levels and 7.3% had increased ALT levels. CONCLUSION: The results in this population show that the use of oral isotretinoin for the treatment of acne may result in altered triglyceride, AST and ALT levels. These findings are in accordance with data published previously in the scientific literature, confirming the need to monitor these patients.

scholarly journals Comparison of tensile properties of thermo cured acrylic resins for the preparation of denture bases

2017 ◽  
Vol 19 (1) ◽  
Author(s):  
Juán José Castillo ◽  
Santiago Herrera ◽  
Pablo Andrés Rey ◽  
Carlos Mejía Pavony ◽  
Adriana Jaramillo
Keyword(s):  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Laboratory Tests ◽  
Acrylic Resin ◽  
High Impact ◽  
Technical Standard ◽  
Fracture Elongation ◽  
Acrylic Resins ◽  
Significant Difference

SUMMARYObjective: The purpose of this in vitro studywas to compare the tensile strength betweentwo materials for the manufacture ofacrylic denture bases (Veracril® from NewStetic and SR Triplex Hot® from IvoclarVivadent), and to know the mechanicalproperties of materials to study that haveclinical implications.Methods: Laboratory tests were conductedunder the technical standard of ASTMInternational # D 638-03 to evaluate thetwo acrylic resin materials for denturebases, processed by pressed moulding. Theobservations were made using the universaltesting machine Tinius Olsen® brandH50KS to analyze the tensile propertiessuch as modulus of elasticity, elongation,yield strength, maximum strength, energy,effort and tensile stress between the twomaterials evaluated.Results: For the effort, maximum strengthand modulus of elasticity, high-impactacrylic resin SR Triplex Hot® showedhigher values. With regard to the characteristicsof maximum displacementbefore the fracture, elongation and energy,conventional acrylic resin showed highervalues. The only characteristic that showeda significant difference between the twogroups of thermo-cured acrylic resin wasthe modulus of elasticity where the highimpactacrylic resin obtained a much highervalue than conventional acrylic resin.Conclusions: The acrylic resin SR TriplexHot® presents higher values in some tensileproperties, while the Veracril® showsbetter in others. The only characteristic thatshowed a significant difference betweenthe two acrylic resins was the modulus ofelasticity.Keywords: Acrylic resin denture bases,tensile strength, high impact acrylic resin.

scholarly journals A Novel Polishing Paste (Mollusk Shells) for Poly (Methylmethacrylate)

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Nicole Guerra ◽  
Evelin Meneses ◽  
Stefany Caballero-García ◽  
Frank Mayta-Tovalino
Keyword(s):  
Surface Roughness ◽  
Acrylic Resin ◽  
Wilcoxon Test ◽  
Stone Surface ◽  
Pumice Stone ◽  
Mean Values ◽  
Significance Level ◽  
Mollusk Shells ◽  
Paired Wilcoxon Test

Objective. The aim of this study was to evaluate the effectiveness of a mollusk shells polishing paste (Donax obesulus) on the surface roughness of acrylic resin poly (methylmethacrylate) (PMMA). Methods. This study was an in vitro experimental design. A sample size of 72 was divided into 4 groups of n = 18 each. PMMA specimens were prepared and polished with the evaluated pastes using mollusk shells (experimental paste) and pumice stone. Surface roughness (μm) was measured using a profilometer after polishing the PMMA samples. The paired Wilcoxon test was used to evaluate the roughness values at 24 and 48 hours. Then, the Mann–Whitney U test was used to identify the differences between the effects of the two groups evaluated with a significance level of α = 0.05. Results. The roughness difference between the pastes under study was compared, and mean values of 0.50 ± 0.07 μm (mollusk shell paste group) and 0.45 ± 0.12 μm (pumice group) were obtained. No statistically significant differences were found between the experimental paste and pumice stone paste p = 0.309 . The specimens polished with pumice stone paste showed higher roughness values, while those polished with the experimental paste exhibited the lowest values. Conclusion. In summary, mollusk shells polishing paste had a decrease in roughness values compared to pumice, although these differences were not statistically significant.

LR White acrylic resin polymerized by microwave energy for immuno-EM of Saccharomyces cerevisiae: A rapid method

1991 ◽  
Vol 49 ◽  
pp. 294-295 ◽  
Author(s):  
B. L. Giammara ◽  
A. O. Rose ◽  
J. S. Hanker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Low Temperature ◽  
Room Temperature ◽  
Acrylic Resin ◽  
Microwave Energy ◽  
Selective Medium ◽  
Polyester Resins ◽  
Low Viscosity ◽  
Lr White

Microwave embedment methods have been developed for epoxy and polyester resins. Because the thick yeast cell wall is known to inhibit penetration by many embedding media, we wished to use an embedding agent exhibiting favorable properties of hydrophilicity and low viscosity. The complex requirement for low temperature and curing using UV irradiation with the polymer Lowicryl, and recent advantages described for yeast using LR White, made the latter polymer a good candidate for our studies.Saccharomyces cerevisiae was grown at 30°C in selective medium to an OD640 = 1.0. A modification of the procedure of Tuinen and Riezman was used to fix the cells. Briefly, the cells were washed three times with Sorenson's buffer, pH 7.3, and fixed as a suspension in 3% paraformaldehyde, 0.25% glutaraldehyde in Sorenson's for 2 hours at room temperature. The cells were again washed three times followed by incubation in 1 % sodium meta-periodate at room temperature for one hour.

Influence of Resin on the Performance of Water-Based Plastic Gravure Ink

2011 ◽  
Vol 287-290 ◽  
pp. 1680-1684
Author(s):  
Mao Jie Yu ◽  
Bei Qing Huang ◽  
Xian Fu Wei
Keyword(s):  
Wear Resistance ◽  
Acrylic Resin ◽  
Low Viscosity ◽  
Adhesion Wear ◽  
Water Based ◽  
Pet Film ◽  
Resistance Performance

Resin as an important part of water-based plastic gravure ink which directly affect the performance of ink. In order to improve the performance of water-based plastic gravure ink，fixing other components and changing the type of resin to prepare ink. Viscosity of ink was measured. Proof the ink on PET film and the effect of resin on water-based plastic gravure ink was inspected through measuring adhesion, wear resistance and glossiness of the ink. The results indicate that water-based plastic gravure ink was prepared by acrylic resin S-2661D has low viscosity, high glossiness; water-based plastic gravure ink was prepared by acrylic resin 2661-91-3 has better ink adhesion, wear resistance performance.

Study on Preparation and Property of Acrylic Resins Used for Water-Based Ink

2012 ◽  
Vol 262 ◽  
pp. 491-496 ◽  
Author(s):  
Wen Tao Huang ◽  
Guang Xue Chen ◽  
Bao Ling Tang ◽  
Ming Guang Yu
Keyword(s):  
Acrylic Resin ◽  
Ammonium Persulfate ◽  
Solid Content ◽  
Water Soluble ◽  
Acrylic Emulsion ◽  
Low Viscosity ◽  
Acrylic Resins ◽  
Film Forming ◽  
Water Based ◽  
Relationship Of

In this paper, a kind of water-soluble acrylic emulsion with methyl methacrylate (MMA) and butyl acrylate (BA) as hard and soft monomer respectively, acrylic acid (AA) and hydroxypropyl methacrylate as functional monomers, ammonium persulfate (APS) and ammonia as initiator and neutralizer respectively, was prepared by emulsion polymerization. The resulting emulsion possesses high solid content, low viscosity, high stability and film-forming properties, indicating that it would be applicable to water-based ink. The effect of the ratio of MMA to BA on the film-forming properties of resin and the influence of AA and HPA on the water-soluble property and viscosity of resin were investigated, and the relationship of reaction temperature and the emulsion stability was also studied. This paper can provides a certain reference to synthesis of acrylic resin and application of acrylic resin to the water-based ink.

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