scholarly journals Effect of Artificial Saliva on the Apatite Structure of Eroded Enamel

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaojie Wang ◽  
Boriana Mihailova ◽  
Arndt Klocke ◽  
Stefanie Heidrich ◽  
Ulrich Bismayer
Keyword(s):  
Citric Acid ◽  
Ph Value ◽  
Artificial Saliva ◽  
Additional Treatment ◽  
Attenuated Total Reflectance ◽  
Apatite Structure ◽  
Total Reflectance ◽  
Time Period ◽  
The Individual ◽  
Induced Changes

Citric acid-induced changes in the structure of the mineral component of enamel stored in artificial saliva were studied by attenuated total reflectance infrared spectroscopy as well as complementary electron probe microanalysis and scanning electron microscopy. The results indicate that the application of artificial saliva for several hours (the minimum time period proved is 4 h) leads to slight, partial recovering of the local structure of eroded enamel apatite. However, artificial saliva surrounding cannot stop the process of loosening and breaking of P–O–Ca atomic linkages in enamel subjected to multiple citric acid treatments. Irreversible changes in the atomic bonding within 700 nm thick enamel surface layer are observed after three times exposure for 1 min to aqueous solution of citric acid having a pH value of 2.23, with a 24-hour interval between the individual treatments. The additional treatment with basic fluoride-containing solutions (1.0% NaF) did not demonstrate a protective effect on the enamel apatite structure per se.

The effects of ultraviolet and visible light on common furs: Color changes, photooxidation and the use of Tinuvin 292 as a photoprotectant

2016 ◽  
Vol 30 (1-2) ◽  
pp. 15-33
Author(s):  
Corina E. Rogge ◽  
Anya Shullman
Keyword(s):  
Visible Light ◽  
Uv Radiation ◽  
Light Exposure ◽  
Mechanical Damage ◽  
Attenuated Total Reflectance ◽  
Preventative Treatment ◽  
Total Reflectance ◽  
B Values ◽  
Color Changes ◽  
Induced Changes

Abstract In order to determine the light sensitivities of commonly encountered furs, 17 furs from 12 species were exposed to 1.97 Mlx hours of light from a xenon arc lamp, filtered either to simulate window-filtered daylight or to remove all ultraviolet (UV) radiation. Comparison with coexposed Blue Wools showed that most samples were relatively lightfast (Blue Wool 5 or better), with darker specimens being more lightfast. Examination of the Commission internationale de l'éclairage (CIE) L*a*b* values revealed fading but also other changes: some furs darkened, and other experienced changes in b* values. Removal of UV radiation prevented darkening and usually decreased the magnitude of ΔE76 but did not prevent color changes, and one species exhibited greater change under visible light. Changes in color were accompanied by photooxidation of the keratin of all species as assessed by attenuated total reflectance infrared spectroscopy; the extent of photooxidation was decreased by filtering out UV radiation. Pre-exposure treatment with a spray application of a 1% solution of Tinuvin 292, a hindered amine light stabilizer, offered some protection against both UV and visible light-induced changes. Tinuvin 292 pre-exposure also helped prevent keratin photooxidation and light-induced mechanical damage and thus may be an appropriate preventative treatment when light exposure is unavoidable.

scholarly journals Sterilization Induced Changes in Polypropylene-Based Ffp2 Masks

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4107
Author(s):  
Emmanuel Richaud ◽  
Muriel Ferry ◽  
Floriane Carpentier ◽  
Sophie Rouif ◽  
Laurent Cortella ◽  
...  
Keyword(s):  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Attenuated Total Reflectance ◽  
Beam Irradiation ◽  
Medical Field ◽  
Total Reflectance ◽  
Exclusion Chromatography ◽  
Mode Size ◽  
Γ Rays ◽  
Induced Changes

In the context of the SARS-CoV2 pandemic and because of the surgical and FFP2 mask (equivalent to the American N95 masks) shortages, studies on efficient sterilization protocols were initiated. As sterilization using irradiation is commonly used in the medical field, this method was among those that were evaluated. In this work, we tested irradiation under vacuum and under air (under both γ-rays and e-beams), but also, for acceptance purposes, undertook washing prior to the e-beam irradiation sterilization process. This article deals with the modifications induced by the sterilization processes at the molecular and the macromolecular scales on an FFP2 mask. Fourier transform infrared spectroscopy in attenuated total reflectance mode, size-exclusion chromatography and thermal-desorption–gas chromatography–mass spectrometry were used to characterize possible damage to the materials. It appeared that the modifications induced by the different sterilization processes under vacuum were relatively tenuous and became more significant when irradiation was performed using γ-rays under air.

In Vitro Study on Bleached Enamel

2007 ◽  
Vol 361-363 ◽  
pp. 833-836
Author(s):  
Xiao Jie Wang ◽  
Boriana Mihailova ◽  
Arndt Klocke ◽  
Stefanie Heidrich ◽  
Ulrich Bismayer
Keyword(s):  
Citric Acid ◽  
Aqueous Solutions ◽  
Electron Probe ◽  
In Vitro Study ◽  
Superficial Layer ◽  
Commercial Product ◽  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
Surface Crystal

The surface crystal chemistry of enamel treated with peroxide-based (the commercial product Opalescence Xtra Boost as well as aqueous solutions of H2O2) and citric-acid-containing bleaching agents (the commercial product Rapid White as well as aqueous solutions of C6H8O7) were studied by Attenuated Total Reflectance Infrared Spectroscopy and electron-probe microanalysis. The results show that the treatment with H2O2-based reagents leads to no side effects on the enamel superficial layer, whereas C6H8O7-based agents deteriorate the enamel mineral component. Hence, bleaching with citric-acid-containing products cannot be recommended.

Electrochemical Behavior of Cobalt-Chromium Alloy as Biomaterial in Different pH Environments

2016 ◽  
Vol 1139 ◽  
pp. 59-63 ◽  
Author(s):  
Lidia Benea ◽  
Valentin Marian Dumitraşcu ◽  
Eliza Dănăilă
Keyword(s):  
Citric Acid ◽  
Ph Value ◽  
Artificial Saliva ◽  
Aqueous Media ◽  
Localized Corrosion ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Solution Ph ◽  
Liquid Environment ◽  
Cobalt Chromium Alloy

The paper discusses the electrochemical interactions of Co-Cr alloy with different physiological solutions and organic substances, containing different ions and different pH values, which should play a key role in the materials lifetime. The physical and chemical reactions are numerous and the passivity of the Co-Cr alloy is submitted to the influence of the liquid environment. Some electrochemical investigations were carried out for understanding and predicting the passivity and the corrosion resistance of Co-Cr alloy in three types of simulated body fluids (SBF), namely Fusayama Meyer artificial saliva (pH=5), Hank’s solution (pH=7.4), Ringer's solution (pH=6.6) and citric acid as organic solution. The reason of using another type of environment (other than SBF), such as citric acid is that this medium is a powerful oxidant and has a lower pH value (pH=1.8). This acid environment can influence the state (the formation and growth) of the oxide layer on the surface of the alloy. Research has shown different behavior of the cobalt chromium alloy according to the pH, the chloride content and the oxidizing nature of the environment. Co-Cr alloy biomaterial, immersed in four aqueous media reveals that there are different levels of stabilization of the potential and different current densities depending on the pH value. The Co-Cr alloy biomaterial is very sensitive to localized corrosion (pitting) in Hank solution.

scholarly journals In situ ATR-FTIR investigation and theoretical calculation of the interactions of chromate and citrate on the surface of haematite (α-Fe2O3)

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 41011-41016 ◽  
Author(s):  
W. G. Gao ◽  
X. C. Liu ◽  
M. F. Chen
Keyword(s):  
Fourier Transform ◽  
Citric Acid ◽  
Theoretical Calculation ◽  
Ftir Spectroscopy ◽  
Attenuated Total Reflectance ◽  
Water Interface ◽  
Total Reflectance ◽  
Kinetics Of ◽  
Ftir Investigation

In situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy was used to study the molecular kinetics of Cr(vi) reduction by citric acid at the α-Fe2O3–water interface.

The Utilization of Ftir (Fourier Transform Infra-Red) Method Combined with Chemometrics For Authentication of Indonesian Coffee Powder

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Firmansyah A. ◽  
Winingsih W. ◽  
Soebara Y S
Keyword(s):  
Fourier Transform ◽  
Natural Product ◽  
High Performance ◽  
Principal Component ◽  
Raw Material ◽  
Attenuated Total Reflectance ◽  
Coffee Bean ◽  
Product Analysis ◽  
Total Reflectance ◽  
And Cluster Analysis

Analysis of natural product remain challenging issues for analytical chemist, since natural products are complicated system of mixture. The most popular methods of choice used for quality control of raw material and finished product are high performance liquid chromatography (HPLC), gas chromatography (GC) and mass spectrometry (MS). The utilization of FTIR-ATR (Fourier Transform Infrared-Attenuated Total Reflectance) method in natural product analysis is still limited. This study attempts to expand the use of FTIR spectroscopy in authenticating Indonesian coffee powder.The coffee samples studied were taken from nine regions in Indonesia, namely Aceh Gayo, Flores, Kintamani, Mandheling, Papua, Sidikalang, Toraja, Kerinci and Lampung.The samples in the form of coffee bean from various regions were powdered . The next step conducted was to determine the spectrum using the FTIR-ATR (Attenuated Total Reflectance) using ZnSe crystal of 8000 resolution. Spectrum samples, then, were analyzed using chemometrics. The utilized chemometric model was the principal component analysis (PCA) and cluster analysis (CA). Based on the chemometric analysis, there are similarities between Aceh Gayo coffee with Toraja coffee, Mandailing coffee, Kintamani coffee and Flores coffee. Sidikalang coffee has a similarity to Flores coffee; Papua coffee has a similarity to Sidikalang coffee; Lampung coffee has a similarity to Sidikalang coffee, while Kerinci coffee has a similarity to Papua coffee.

Quality evaluation of tugaksheeree samples by ATR-FTIR spectroscopy using multicomponent analysis

2020 ◽  
Vol 10 ◽  
Author(s):  
Nikunj D. Patel ◽  
Niranjan S. Kanaki
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Quality Evaluation ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Attenuated Total Reflectance ◽  
Chemometric Methods ◽  
Total Reflectance ◽  
Fingerprint Region ◽  
Ftir Technique

Background: Numerous Ayurvedic formulations contains tugaksheeree as key ingredient. Tugaksheereeis the starch gained from the rhizomes of two plants, Curcuma angustifoliaRoxb. (Zingiberaceae) and Marantaarundinacea (MA) Linn. (Marantaceae). Objective: The primary concerns in quality assessment of Tugaksheeree occur due to adulteration or substitution. Method: In current study, Fourier transform infrared (FTIR) technique with attenuated total reflectance (ATR) facility was used to evaluate tugaksheeree samples. Total 10 different samples were studied and transmittance mode was kept to record the spectra devoid of pellets of KBR. Further treatment was given with multi component tools by considering fingerprint region of the spectra. Multivariate analysis was performed by various chemometric methods. Result: Multi component methods like Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA)were used to discriminate the tugaksheeree samples using Minitab software. Conclusion: This method can be used as a tool to differentiate samples of tugaksheeree from its adulterants and substitutes.

Negatively Charged Ions to Probe Self-Assembled Monolayers Reorganization Driven by Interchain Interactions

2021 ◽  
Author(s):  
Angelo Tricase ◽  
Angela Stefanachi ◽  
Rosaria Anna Anna Picca ◽  
Eleonora Macchia ◽  
Alessandro Favia ◽  
...  
Keyword(s):  
Grazing Angle ◽  
Self Assembled Monolayers ◽  
Attenuated Total Reflectance ◽  
Interchain Interaction ◽  
Total Reflectance ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Interchain Interactions ◽  
Ir Study ◽  
Charged Ions

A combined cyclic voltammetry (CV) and grazing angle – attenuated total reflectance (GA-ATR) IR study on the interchain interaction driven reorganization of self-assembled monolayers (SAMs) in an electric field, is...

Detection of bloodstains using attenuated total reflectance-Fourier transform infrared spectroscopy supported with PCA and PCA–LDA

2021 ◽  
pp. 002580242110109
Author(s):  
Sweety Sharma ◽  
Rito Chophi ◽  
Jaskirandeep Kaur Jossan ◽  
Rajinder Singh
Keyword(s):  
Fourier Transform ◽  
Ftir Spectroscopy ◽  
Body Fluid ◽  
Due Process ◽  
Dna Analysis ◽  
Fourier Transform Infrared ◽  
Body Fluids ◽  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
Non Destructive

The most important task in a criminal investigation is to detect and identify the recovered biological stains beyond reasonable scientific doubt and preserve the sample for further DNA analysis. In the light of this fact, many presumptive and confirmatory tests are routinely employed in the forensic laboratories to determine the type of body fluid. However, the currently used techniques are specific to one type of body fluid and hence it cannot be utilized to differentiate multiple body fluids. Moreover, these tests consume the samples in due process, and thus it becomes a great limitation especially considering the fact that samples are recovered in minute quantity in forensic cases. Therefore, such limitations necessitate the use of non-destructive techniques that can be applied simultaneously to all types of bodily fluids and allow sample preservation for further analysis. In the current work, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy has been used to circumvent the aforementioned limitations. The important factors which could influence the detection of blood such as the effect of substrates, washing/chemical treatment, ageing, and dilution limits on the analysis of blood have been analysed. In addition, blood discrimination from non-blood substance (biological and non-biological in nature) has also been studied. Chemometric technique that is PCA–LDA has been used to discriminate blood from other body fluids and it resulted in 100% accurate classification. Furthermore, blood and non-blood substances including fake blood have also been classified into separate clusters with a 100% accuracy, sensitivity, and specificity. All-inclusive, this preliminary study substantiates the potential application of ATR-FTIR spectroscopy for the non-destructive identification of blood traces in simulated forensic casework conditions with 0% rate of false classification.

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