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

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.

Download Full-text

Infrared Fiber-Optic Spectroscopy Detects Bovine Articular Cartilage Degeneration

Cartilage ◽

10.1177/1947603521993221 ◽

2021 ◽

pp. 194760352199322

Author(s):

Vesa Virtanen ◽

Ervin Nippolainen ◽

Rubina Shaikh ◽

Isaac O. Afara ◽

Juha Töyräs ◽

...

Keyword(s):

Support Vector Machine ◽

Infrared Spectroscopy ◽

Articular Cartilage ◽

Fiber Optic ◽

Mechanical Damage ◽

Attenuated Total Reflectance ◽

Support Vector ◽

Mid Infrared ◽

Total Reflectance ◽

Joint Injuries

Objective Joint injuries may lead to degeneration of cartilage tissue and initiate development of posttraumatic osteoarthritis. Arthroscopic surgeries can be used to treat joint injuries, but arthroscopic evaluation of articular cartilage quality is subjective. Fourier transform infrared spectroscopy combined with fiber optics and attenuated total reflectance crystal could be used for the assessment of tissue quality during arthroscopy. We hypothesize that fiber-optic mid-infrared spectroscopy can detect enzymatically and mechanically induced damage similar to changes occurring during progression of osteoarthritis. Design Bovine patellar cartilage plugs were extracted and degraded enzymatically and mechanically. Adjacent untreated samples were utilized as controls. Enzymatic degradation was done using collagenase and trypsin enzymes. Mechanical damage was induced by (1) dropping a weight impactor on the cartilage plugs and (2) abrading the cartilage surface with a rotating sandpaper. Fiber-optic mid-infrared spectroscopic measurements were conducted before and after treatments, and spectral changes were assessed with random forest, partial least squares discriminant analysis, and support vector machine classifiers. Results All models had excellent classification performance for detecting the different enzymatic and mechanical damage on cartilage matrix. Random forest models achieved accuracies between 90.3% and 77.8%, while partial least squares model accuracies ranged from 95.8% to 84.7%, and support vector machine accuracies from 91.7% to 80.6%. Conclusions The results suggest that fiber-optic Fourier transform infrared spectroscopy attenuated total reflectance spectroscopy is a viable way to detect minor and major degeneration of articular cartilage. Objective measures provided by fiber-optic spectroscopic methods could improve arthroscopic evaluation of cartilage damage.

Download Full-text

Effect of Artificial Saliva on the Apatite Structure of Eroded Enamel

International Journal of Spectroscopy ◽

10.1155/2011/236496 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 5

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.

Download Full-text

Sterilization Induced Changes in Polypropylene-Based Ffp2 Masks

Polymers ◽

10.3390/polym13234107 ◽

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.

Download Full-text

Dichroic Measurements on Dicationic and Tetracationic Porphyrins on Clay Surfaces with Visible-Light-Attenuated Total Reflectance

Bulletin of the Chemical Society of Japan ◽

10.1246/bcsj.80.1350 ◽

2007 ◽

Vol 80 (7) ◽

pp. 1350-1356 ◽

Cited By ~ 33

Author(s):

Miharu Eguchi ◽

Hiroshi Tachibana ◽

Shinsuke Takagi ◽

Donald A. Tryk ◽

Haruo Inoue

Keyword(s):

Visible Light ◽

Attenuated Total Reflectance ◽

Total Reflectance

Download Full-text

Fourier transform IR attenuated total reflectance spectroscopy studies of cysteine-induced changes in secondary conformations of bovine serum albumin after UV-B irradiation

Biopolymers ◽

10.1002/bip.10436 ◽

2003 ◽

Vol 72 (5) ◽

pp. 345-351 ◽

Cited By ~ 15

Author(s):

Yen-Shan Wei ◽

Shan-Yang Lin ◽

Shun-Li Wang ◽

Mei-Jane Li ◽

Wen-Ting Cheng

Keyword(s):

Fourier Transform ◽

Bovine Serum Albumin ◽

Serum Albumin ◽

Bovine Serum ◽

Reflectance Spectroscopy ◽

Attenuated Total Reflectance ◽

Total Reflectance ◽

Fourier Transform Ir ◽

Spectroscopy Studies ◽

Induced Changes

Download Full-text

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

International Journal of Pharmaceutical and Clinical Research ◽

10.25258/ijpcr.v9i3.8320 ◽

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.

Download Full-text

Faculty Opinions recommendation of Modified DNA analogues that sense light exposure with color changes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1021699.246672 ◽

2004 ◽

Author(s):

Kevin J Luebke

Keyword(s):

Light Exposure ◽

Color Changes ◽

Modified Dna

Download Full-text

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

Current Catalysis ◽

10.2174/2211544708666190124114519 ◽

2019 ◽

Vol 8 (1) ◽

pp. 56-61

Author(s):

Aneeya K. Samantara ◽

Debasrita Dash ◽

Dipti L. Bhuyan ◽

Namita Dalai ◽

Bijayalaxmi Jena

Keyword(s):

Electron Transfer ◽

Photocatalytic Activity ◽

Visible Light ◽

Transfer Rate ◽

Photocatalytic Performance ◽

Light Exposure ◽

Au Nanoparticle ◽

Electron Transfer Rate ◽

Au Nps ◽

Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

Download Full-text

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

The Natural Products Journal ◽

10.2174/2210315510999200408125555 ◽

2020 ◽

Vol 10 ◽

Cited By ~ 1

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.

Download Full-text