Portable Spectrophotometer Research Articles

One-step effervescence tablet-assisted switchable hydrophilic solvent microextraction combined with micro spectrophotometry for the determination of copper in Salvia yunnanensis and environmental samples

In this work, an efficient one-step effervescence tablet-assisted switchable hydrophilic solvent microextraction (ETA-SHS-ME) method was developed and firstly combined with micro ultraviolet-visible (micro UV-Vis) spectrophotometry for the determination of trace copper (Cu) in natural medicine Salvia yunnanensis and environmental samples (water and soil). The extraction was rapidly accomplished in one step by transferring the effervescence tablet into the aqueous sample, the proton donor agent (malonic acid) contained in the tablet reacted simultaneously with the organic phase source (sodium nonanoate) and the effervescent agent (sodium bicarbonate, NaHCO3) to produce the extractant nonanoic acid and CO2. The in situ generated CO2 promoted the dispersion of nonanoic acid in the aqueous sample and improved the extraction efficiency of the analytical method. Under the optimal conditions, the limit of detection (LOD) and the limit of quantification (LOQ) were 0.01 and 0.04 μg/L, respectively, and the enhancement factor (EF) was 76.3. The developed method was successfully applied to the analysis of trace Cu in natural medicine and environmental samples. The one-step extraction method coupled with portable spectrophotometer has a good prospect for application in field analysis.

Probe-based spectrophotometric quantification of petrol-ethanol fuel blends for field-able applications

• Easy & precise quantification of ethanol-petrol blends using probe-based absorption spectroscopy • Selection and introduction of probing molecule in a simple and legitimate manner using a biodegradable hydrogel. • Generalized method for the accurate quantification of blends with fuel sample of different origin • Possibility of devising a low-cost, portable, layman-friendly and fieldable tool for fuel blend composition • Two modes of quantification: Hyperchromic enhancement monitoring and Sample-independent ratiometric analysis using band pass excitation Blending a cleaner, less expensive fuel like ethanol to petrol is a low-hanging fruit to address fuel crisis. However, blending bioethanol beyond the permissible limit can eventually corrode engine parts and cause fuel tank swelling. As a result, ensuring the quality of fuel blends is a critical step for consumers. We propose an inexpensive method for the precise quantification of fuel blend composition using a probing technique that exploits the structural switching and consequent change in transition probability of the probe molecule in polar and non-polar media. The UV-visible absorption spectrum of the probe is capable of exhibiting a hyperchromic shift with increasing ethanol composition in the blend. Two calibration models have been constructed based on the data - the hyperchromic shift-based model yielded excellent analytical figures of merit with LOD, LOQ and RMSEP values of 0.02,0.08 and 0.23%, respectively. Calibration using ratiometric analysis showed a LOD, LOQ and RMSEP values of 0.01,0.04 and 0.13 %, respectively. The approach provided a simpler and sample-independent method that can be easily integrated into a LED-spectrophotometer for commercial and in-situ applications. A novel, biodegradable- hydrogel based probe delivery is illustrated and optimized. An analysis of real samples has been carried out using our method and the results discussed. A portable LED spectrophotometer- 'ethano-meter' for quantifying ethanol in fuel blends using an external probe molecule is proposed for in-situ fuel quality control.

Low-cost VIS/NIR range hand-held and portable photospectrometer and evaluation of machine learning algorithms for classification performance

In this study, the electronic design of a low-cost and portable spectrophotometer device capable of analyzing in the visible-near infrared region was established. The design of C#.NET-based user-friendly device control software and the development of machine learning algorithms for data classification as well as the comparison of the results were presented. When the spectrophotometer design and implementation studies are reviewed in the literature, two groups of subjects become prominent: (i) a new device fabrication, (ii) solution approaches to current problems by combining commercial portable spectrometer systems and devices with artificial intelligence applications. This work encompasses both groups, and a supportive approach has been followed on how to transform the theoretical knowledge into practice in device development and supportive software with the help of machine learning approaches from design to production. Three commercial spectral sensors, each with six photodiode arrays, were adopted in the spectrophotometer. Thus, 18 features belonging to each sample were acquired in the optical spectral region in the 410 nm to 940 nm band range. The spectral analyses were conducted with 9 different food types of powder or flake structures. A Support Vector Machines (SVM) and Convolutional Neural Network (CNN) approaches were employed for data classification. As a result, SVM and CNN achieved 97% and 95% accuracies, respectively. Moreover, we provided the spectral measurement data, the electronic circuit designs, the API files containing the artificial intelligence algorithms and the graphical user interface (GUI).

Study on the Color-Influencing Factors of Blue Iolite

This article explores the factors that influence the color of blue iolite, which is the gem-quality variety of the cordierite mineral. The X-Rite SP62 portable spectrophotometer was used to measure color in the CIELAB color space. ED-XRF and UV–vis were used for analysis. The results show that blue iolite contains the chromophore elements Fe and Mn, but the effect on the color of iolite is not significant due to the low Mn content. The lightness L* and the hue angle h° are mostly determined by its Fe content. UV–vis spectra show that iolite has a broad absorption band near 570 nm caused by the charge transfer between Fe2+ on the octahedron and Fe3+ on the T11 tetrahedron and results in the color of blue iolite. Each different standard light source has different degrees of influence on the color parameters of iolite, and the hue angle h° is the most influenced.

A non-invasive ultrasensitive diagnostic approach for COVID-19 infection using salivary label-free SERS fingerprinting and artificial intelligence.

Clinical diagnostics for SARS-CoV-2 infection usually comprises the sampling of throat or nasopharyngeal swabs that are invasive and create patient discomfort. Hence, saliva is attempted as a sample of choice for the management of COVID-19 outbreaks that cripples the global healthcare system. Although limited by the risk of eliciting false-negative and positive results, tedious test procedures, requirement of specialized laboratories, and expensive reagents, nucleic acid-based tests remain the gold standard for COVID-19 diagnostics. However, genetic diversity of the virus due to rapid mutations limits the efficiency of nucleic acid-based tests. Herein, we have demonstrated the simplest screening modality based on label-free surface enhanced Raman scattering (LF-SERS) for scrutinizing the SARS-CoV-2-mediated molecular-level changes of the saliva samples among healthy, COVID-19 infected and COVID-19 recovered subjects. Moreover, our LF-SERS technique enabled to differentiate the three classes of corona virus spike protein derived from SARS-CoV-2, SARS-CoV and MERS-CoV. Raman spectral data was further decoded, segregated and effectively managed with the aid of machine learning algorithms. The classification models built upon biochemical signature-based discrimination method of the COVID-19 condition from the patient saliva ensured high accuracy, specificity, and sensitivity. The trained support vector machine (SVM) classifier achieved a prediction accuracy of 95% and F1-score of 94.73%, and 95.28% for healthy and COVID-19 infected patients respectively. The current approach not only differentiate SARS-CoV-2 infection with healthy controls but also predicted a distinct fingerprint for different stages of patient recovery. Employing portable hand-held Raman spectrophotometer as the instrument and saliva as the sample of choice will guarantee a rapid and non-invasive diagnostic strategy to warrant or assure patient comfort and large-scale population screening for SARS-CoV-2 infection and monitoring the recovery process.

The feasibility study of objective evaluation of the severity of motion sickness by quantitative analysis of the facial skin color

Objective: To explore the feasibility of applying quantitative analysis of the facial skin color to evaluate the severity of motion sickness objectively and to seek objective indicators that can reflect the severity of motion sickness. Methods: Motion sickness was induced in 51 male adult subjects recruited at the Air Force Medical University by Coriolis acceleration stimulation, and facial skin colorimetric values were acquired using a portable spectrophotometer at five time points: before stimulation and at 0 min, 10 min, 20 min and 30 min after the end of stimulation. The Graybiel rating scales were applied to assess the severity of motion sickness in subjects at each time point after stimulation, and the correlation between the magnitude of change in each colorimetric value and the maximum Graybiel's score was analyzed. The ROC curves were used to compare the evaluation performance of colorimetric value indicators which could reflect the severity of motion sickness. Results: Each colorimetric value in the CIE-L*a*b* color system changed significantly after exposure to provocative motion stimuli, and the trend was consistent with the typical sign of pallor in motion sickness. The magnitudes of the increase in the colorimetric value CIE-L*, the decrease in CIE-a*, and the increase in CIE-b* were all significantly and positively correlated with the maximum of Graybiel's scores (r=0.490 0, P=0.000 3; r=0.549 3, P<0.000 1; r=0.540 9, P<0.000 1). Comparing the performance of three colorimetric indicators to assess the severity of motion sickness, CIE-a* had an area under the ROC curve of 0.875 0, a sensitivity of 85.71%, and a specificity of 87.50%, which was better than CIE-L* and CIE-b*. Conclusions: The CIE-L*a*b* colorimeter values can be considered as objective indicators of the severity of motion sickness, among which the colorimetric indicator CIE-a* has the most diagnostic significance, and the method of quantitative analysis of the facial skin color can provide a new reference for the objective evaluation of the severity of motion sickness.

Influence of the self-adhering strategy on microhardness, sorption, solubility, color stability, and cytotoxicity compared to bulk-fill and conventional resin composites.

To analyze and compare, in vitro, the microhardness, sorption, solubility, color stability, and cytotoxicity of three types of resin composites: self-adhesive (SARC) (Dyad Flow (DF)/Kerr), bulk-fill (Filtek Bulk Fill Flow (FBF)/3M ESPE), and conventional (Filtek Z350XT Flow (Z350)/3M ESPE). Thirty cylindrical specimens were prepared using a split metal mold (15mm × 1mm), divided into 3 groups (n = 10) according to the material used. Vickers hardness (VH) was calculated from three indentations (300gf/15s) per specimen. The sorption and solubility were measured according to the ISO 4049:2009 specification after storing in distilled water for 7days. The color of each resin composite was measured using a portable digital spectrophotometer according to the CIELAB system. After a 7-day immersion in coffee, the color variation (∆E) was calculated. Following the ISO 10993:2012, the cytotoxicity in Vero cells was evaluated through the MTT assay. The results were analyzed using the Kruskal-Wallis test to compare the studied groups. The Wilcoxon test was used to compare the assessments in each studied group. For cytotoxicity analysis, the data were compared by the ANOVA test (α = 0.05). DF showed the lowest VH (28.67), highest sorption (0.543µg/mm3) and solubility (1.700µg/mm3), and higher ∆E after 7days of coffee immersion (p = 0.008). The resin composites studied were considered non-cytotoxic. The SARC presented inferior mechanical and physical-chemical properties than bulk-fill and conventional resin composites, with comparable cytotoxicity against Vero cells. The simplification of the clinical protocol of SARC can minimize the number of possible failures during the restorative technique. However, considering their inferior physical and mechanical properties, their coverage with materials of higher mechanical properties and physical-chemical stability should be considered.

Optical characterization of historical coloured stained glasses in winter gardens and their modelling in daylight availability simulations

Coloured stained glasses, with their peculiar light transmission properties, affect the perception of indoor spaces especially in winter gardens, where a great amount of coloured glazed surfaces can be easily found. This research aims at advancing the knowledge of coloured stained glasses in architecture and how they can be modelled in daylight simulation software tools. To this aim, the paper first proposes the measurement of light transmittance spectra for a series of coloured glazing tiles installed in a richly decorated Liberty style winter garden in Catania (Southern Italy). The measurements are performed in-place with a portable spectrophotometer, which does not imply dismantling the glazed tiles. A second novelty consists in the identification of the perceived chromaticity for the transmitted daylight, by means of the CIE Colour Space. This analysis reveals that, despite around 75% of the glazed elements are coloured, indoor light is still perceived as colour-neutral because of the wise location of clear panes.Then, the calculated integral transmittance values were used to model the winter garden in the Radiance-based ClimateStudio tool, and the reliability of two different degrees of simplifications in the model was also investigated. The comparison between simulated and measured indoor illuminance values demonstrates that the proposed simplified approach allows very good reliability in daylight modelling, with an average discrepancy below 11%, while also reducing time needed for the preparation of the model. Finally, the validated model is used to assess year-round daylight availability indoors by means of climate based daylight metrics.

Dual phenomenon of surface plasmon and laser optics induced EM enhancement for rapid DNA detection with semiconductor nanostructures (SiNWs/AgNPs)

Recently exploring bioanalytical instrumentation principles emphasized with combination of optics and EM fields in surface enhanced Raman spectroscopy (SERS). The principles favour the rapid detection of DNA with proper fabrication of SERS sensor. 1D semiconductor nanostructures (SiNWs) functionalization with plasmonic silver nanoparticles are fabricated by PLD process and exploited for SERS detection of DNA. The DNA nucleotide bands are indexed with reference to their Raman shift as Adenine (A), Guanine (G), Cytosine (C), Thymine (T) at Raman spectral regions of 1352 cm-1, 676 cm-1, 1625 cm-1, 1441 cm-1 respectively. The finest conditions for sensitive detection of DNA were investigated and their interaction mechanism are presented. The point-to-point reproducibility measurements imprinted higher degree of concordancy. The designed SERS sensor will be definitely helpful almost in all application fields with portable handheld Raman spectrophotometer in near future.

Diffuse Reflectance Spectrophotometers Based on C12880MA and C11708MA Mini-Spectrometers Hamamatsu

Diffuse reflection spectroscopy with spatial resolution is a promising direction of non-destructive control of the properties of a number of scattering fine-dispersed materials, including food products. It can find wide practical application only in the presence of compact, easy-to-use and inexpensive spectrophotometric equipment. The aim of the article is to investigate the possibility of creating portable spectrophotometers based on Hamamatsu mini-spectrometers, which work together with modern computing facilities.The schematics for connecting the C12880MA and C11708MA mini-spectrometers to portable computing devices are reviewed. Shows the feasibility of using a small-sized microprocessor board ARM STM32F103C8T6 (Blue pill) on the chip STM32F103C8T6. Its use in the connection scheme has simplified data exchange with the control computer via USB interface and the formation of all the signals that are needed to control the mini-spectrometer.Two experimental samples of spectrophotometers based on C12880MA and C11708MA mini-spectrometers and STM32 microprocessors were created and their characteristics were studied. The calibration procedure and features of the software for these spectrophotometers are presented. The described features ensure the efficiency of software modification for the spectrophotometric problem to be solved. The presence of distortions of the registered spectra in the short-wave part of the spectral range of C12880MA was revealed. They arise due to focusing by the concave diffraction grating of a part of the radiation scattered by it into zero order.Approbation of developed portable spectrophotometers based on Hamamatsu mini-spectrometers indicates the possibility of their use in portable spectrophotometric equipment and devices for spectral control of optical properties of scattering materials. The described calibration technique allows you to determine the range of the spectrum, in which the distortions of the recorded spectra are minimal. The proposed solutions significantly reduce the cost of diffuse reflectance spectroscopy devices with spatial resolution and expand the possibilities of their use in various branches of science and industry.

Unscrambling the Provenance of Eggs by Combining Chemometrics and Near-Infrared Reflectance Spectroscopy.

Issues related to food authenticity, traceability, and fraud have increased in recent decades as a consequence of the deliberate and intentional substitution, addition, tampering, or misrepresentation of food ingredients, where false or misleading statements are made about a product for economic gains. This study aimed to evaluate the ability of a portable NIR instrument to classify egg samples sourced from different provenances or production systems (e.g., cage and free-range) in Australia. Whole egg samples (n: 100) were purchased from local supermarkets where the label in each of the packages was used as identification of the layers’ feeding system as per the Australian legislation and standards. The spectra of the albumin and yolk were collected using a portable NIR spectrophotometer (950–1600 nm). Principal component analysis (PCA) and linear discriminant analysis (LDA) were used to analyze the NIR data. The results obtained in this study showed how the combination of chemometrics and NIR spectroscopy allowed for the classification of egg albumin and yolk samples according to the system of production (cage and free range). The proposed method is simple, fast, environmentally friendly and avoids laborious sample pre-treatment, and is expected to become an alternative to commonly used techniques for egg quality assessment.

The lightfastness of early synthetic organic dyes

Synthetic organic colourants are extremely prominent in heritage collections, particularly throughout textiles. They are often generalized as highly light-sensitive; although, a broad distribution of lightfastness exists. This is evident in various fastness ratings published in late nineteenth century literature, the work of Schultz and Julius, and the Colour Index. In heritage conservation, much of the research related to light-sensitivity of dyed textiles has focused on natural colourants. This is likely due to a general interest in the dyes present on older objects, and the overwhelming selection of modern synthetic materials. To address this gap, a shortlist of targeted synthetic dyes was recently developed using census data for dye production and imports in the United States, and information gathered from the Colour Index. Our present work provides a follow up to the prior literature review, where a subset of samples from the published target list was used to evaluate lightfastness. To begin the study, a collection of dyed textiles from the last quarter of the nineteenth century was gathered from trade publications of the period, and those matching the target criteria were reserved for analysis. The lightfastness of more than 100 early synthetic dyes was then investigated using the historic materials. Test specimens were illuminated with a custom-built fadometer containing an LED light source that is characteristic of modern gallery lighting. Four batches of samples were exposed at 20 klx for approximately 6 months each, and diffuse reflectance was periodically measured with a portable spectrophotometer over white and black backgrounds. Measurements were taken at increasing light dose values to reach at least 85 Mlx·h per batch. Visible reflectance spectra were recorded in a dataset to document the colours as a function of light exposure, and foster future colorimetry research. Colour change was also calculated using the CIEDE2000 formula to assess lightfastness, and results were summarized as a resource to further develop risk analysis tools for exhibit lighting. In this paper, a detailed description of the test apparatus is presented with an overview of the lightfastness results and the resulting dataset. Comparisons are given with nineteenth century lightfastness data, and ISO values available in the Colour Index. It is hoped that the associated dataset will provide a foundation to be expanded over time with interest in further materials and test methods.

Evaluation of Two Portable Hyperspectral-Sensor-Based Instruments to Predict Key Soil Properties in Canadian Soils.

In contrast with classic bench-top hyperspectral (multispectral)-sensor-based instruments (spectrophotometers), the portable ones are rugged, relatively inexpensive, and simple to use; therefore, they are suitable for field implementation to more closely examine various soil properties on the spot. The purpose of this study was to evaluate two portable spectrophotometers to predict key soil properties such as texture and soil organic carbon (SOC) in 282 soil samples collected from proportional fields in four Canadian provinces. Of the two instruments, one was the first of its kind (prototype) and was a mid-infrared (mid-IR) spectrophotometer operating between ~5500 and ~11,000 nm. The other instrument was a readily available dual-type spectrophotometer having a spectral range in both visible (vis) and near-infrared (NIR) regions with wavelengths ranging between ~400 and ~2220 nm. A large number of soil samples (n = 282) were used to represent a wide variety of soil textures, from clay loam to sandy soils, with a considerable range of SOC. These samples were subjected to routine laboratory soil analysis before both spectrophotometers were used to collect diffuse reflectance spectroscopy (DRS) measurements. After data collection, the mid-IR and vis-NIR spectra were randomly divided into calibration (70%) and validation (30%) sets. Partial least squares regression (PLSR) was used with leave one out cross-validation techniques to derive the spectral calibrations to predict SOC, sand, and clay content. The performances of the calibration models were reevaluated on the validation set. It was found that sand content can be predicted more accurately using the portable mid-IR spectrophotometer and clay content is better predicted using the readily available dual-type vis-NIR spectrophotometer. The coefficients of determination (R2) and root mean squared error (RMSE) were determined to be most favorable for clay (0.82 and 78 g kg−1) and sand (0.82 and 103 g kg−1), respectively. The ability to predict SOC content precisely was not particularly good for the dataset of soils used in this study with an R2 and RMSE of 0.54 and 4.1 g kg−1. The tested method demonstrated that both portable mid-IR and vis-NIR spectrophotometers were comparable in predicting soil texture on a large soil dataset collected from agricultural fields in four Canadian provinces.

Aminpentacyanoferrate as a carbon monoxide indicator

Carbon monoxide (CO) is a substance that can cause suffocation and death and one of its main sources is the emission of gases in the exhaust of motor vehicles, due to incomplete combustion. For this reason, several countries have important legislation on vehicular pollution. Several analytical techniques for determining CO are used; however, most of them are expensive or require qualified professionals. The purpose of this work was to use the aminpentacianoferrate complex in the development of a spectrophotometric methodology based on the exchange of ammonia ligand (NH3) by carbonyl (CO), with applicability in the rapid determination of carbon monoxide in vehicle emissions. The synthesized complex was characterized in terms of its structure and the analytical parameters were validated. The analytical curve was between 135 mg L-1 and 812 mg L-1, with R2 = 0.9965, with a repeatability of 4.6% and stability of the carbonylated complex of ± 1.0% in 15 minutes. This method was applied to samples of vehicle emission gas having low cost, being possible to use portable spectrophotometers of easy manipulation and access, for fast measurements.

Screening Method for the Detection of Other Allergenic Nuts in Cashew Nuts Using Chemometrics and a Portable Near-Infrared Spectrophotometer

Screening Method for the Detection of Other Allergenic Nuts in Cashew Nuts Using Chemometrics and a Portable Near-Infrared Spectrophotometer

The Effectiveness of a Portable Fluorescence Spectrophotometer for Early Detection of Oral Cancer

Purpose: To investigate whether photodynamic diagnosis (PDD) using a portable fluorescence spectrophotometer (FC-1) can easily and objectively discriminate between normal and tumor cells at the dental chairside, and to further compare it with PDD that requires speculum examination by focusing on protoporphyrin IX (PPIX). Methods: Three cell lines (2 human oral squamous cell carcinoma-derived cell lines, HSC-2 and HSC-3 cells, and oral keratinocytes, HOK cells) were cultured. 5-Aminolevulinic acid hydrochloride (5-ALA) and deferoxamine mesylate (DFO) were mixed in DMEM, and the mixture was set to Control (DMEM only) and PDD (5-ALA+DFO) groups. And then, a fluorescence was measured under room temperature (RT) and 37°C (Incubation) by using FC-1. In this study, the two conditions were combined with the Control and PDD groups to form the Control/RT, Control/Incubate, PDD/RT, and PDD/Incubate groups. Additionally, the amount of singlet oxygen (1O2) generated by irradiation with 405 nm LED was measured using electron spin resonance spectroscopy to detect PPIX in the cell supernatant after 24 hours. Results: In HSC-2 and HSC-3, the fluorescence intensity values increased significantly at 2 hours between the Control/RT and PDD/RT groups. In addition, there was a significant difference between HSC-2 and HSC-3 compared to HOK. In all cell lines, the fluorescence intensity values of the PDD/Incubate group were significantly higher than those of the PDD/Control group. The amount of 1O2 generated by 405 nm LED irradiation was higher in the cell supernatants of all cell lines in the order of Control/RT < Control/Incubate < PDD/RT < PDD/Incubate group, and HSC-3 in the PDD/Incubate group showed a significant increase compared to HOK. Conclusion: It is suggested that PDD using FC-1 can clearly distinguish between normal cells and tumor cells in vitro studies using cell lines at 2 hours under 37°C, and it can detect not only intracellular PPIX, but also extracellular PPIX.

Assessment of the Effectiveness of a Portable NIRS Instrument in Controlling the Mixer Wagon Tuning and Ration Management.

Simple SummaryThe total mixed ration is widely adopted in herds feeding, and its success has paved the way for the use of the feed mixer wagon. The increase in milk production demands a higher feed efficiency that considers the chemical and physical quality of the ration, even in terms of fiber physical effectiveness, ration homogeneity, and cow feed sorting. These requirements presuppose a correct ration formulation and accurate preparation, even through an optimal mixer wagon setting. Here, we proposed an efficient, rapid, and easy method for ration preparation and quality control. A portable Near-InfraRed instrument was tested for primary chemical and physical evaluation of the ration, including the particle size and the physical effective fiber content. Moreover, the instrument allowed the calculation of two indexes to evaluate the ration homogeneity and cow sorting activity. Finally, these traits were compared with the feed mixer wagon setting and feed characteristics. As a result, we found that for the overload of the feed mixer wagon, the higher humidity and fiber contents of the ration caused a lower homogeneity, and the higher fiber content facilitated the cow sorting activity.The adoption of the mixer wagon and total mixed ration aimed to decrease dysmetabolic diseases and improve feed efficiency in dairy cows. Differences between theoretical and eaten diets are imputable to errors in diet preparation or cow feed sorting. We proposed a method to measure the chemical composition and particle size distribution of the ration and determined its peNDF content through a portable Near Infra-Red spectrophotometer that allowed the calculation of two indexes: the homogeneity and the sorting indexes. In a cohort of 19 Italian Holstein breeding farms, we studied the correlation of these indexes with the mixer wagon settings. Determination coefficients in the validation (Rv2) for dry matter, crude protein, aNDF, and starch were 0.91, 0.54, 0.86, and 0.67, respectively. The ration fractions (%, w/w of wet weight) retained by the 3.8 and 1.8 mm sieves, and the bottom showed Rv2 of 0.46, 0.49, and 0.53, respectively. The homogeneity index regressed negatively with the mixer wagon load fullness (R2 = 0.374). The homogeneity-binary classification showed an odds ratio of 1.72 for dry matter and 0.39 for aNDF (p < 0.05). The sorting-binary classification showed an odds ratio of 2.54 for aNDF (p < 0.05). The studied farms showed low peNDF values (median = 17.9%).

Luster measurement of pearl by UV-Vis reflectance spectroscopy

Pearl is an organic gem with its unique color and luster. One of the factors determining the quality and price of pearl is the luster. The different luster of pearls could be related to the different phase structures such as aragonite, calcite and vaterite. Previously, a gloss meter has been developed to measure light specularly reflected at 45° to the surface normal. Six different visual criteria for measuring gloss have been determined. Luster, a type of gloss, was defined as the ratio of specularly reflected light and that diffusely reflected normal to the surface. In practice, luster may be interpreted as relative brightness of specularly and diffusely reflecting areas. Due to the roundness of pearl, we measured the luster of pearl samples by a portable UV-Vis spectrophotometer with an integrating sphere. The luster could be calculated from the difference of CIELAB lightness measured by SCI and SCE geometries.

Effects of methylene blue and curcumin photosensitizers on the color stability of endodontically treated intraradicular dentin

BackgroundPhotodynamic therapy with photosensitizers can reduce the microbial load. However, few studies have evaluated the effects of photosensitizers on the color stability of endodontically treated intraradicular dentin. This in vitro study investigated the effects of methylene blue and curcumin photosensitizers used in photodynamic therapy on the color stability of intraradicular dentin. MethodsSixty human incisors were divided into three experimental groups according to the photosensitizer solutions used and their concentrations: methylene blue (25 mg/L), curcumin (1000 mg/L), and curcumin (1500 mg/L). The color stability of endodontically treated intraradicular dentin was evaluated using a portable reflectance spectrophotometer before and after the samples been storage in 2 mL of the photosensitizer solutions during 5 min (n = 20). Color stability data were subjected to a normality test, and statistical analysis was performed using the one-way analysis of variance and Tukey least significant difference test (α = 0.05). ResultsSamples treated with 25 mg/L methylene blue photosensitizer showed a higher level of color alteration than those stored in 1000 mg/L curcumin (p = .03322). However, there was no significant difference in the color alteration profiles between the samples treated with 25 mg/L methylene blue and 1500 mg/L curcumin (p = .36428). Furthermore, there was no difference in the color alteration profiles between the dentin samples immersed in 1000 mg/L and 1500 mg/L curcumin photosensitizer solutions (p = .45321). ConclusionsMethylene blue and curcumin photosensitizers influenced the color stability of endodontically treated intraradicular dentin, and this color alteration exceeded the clinical acceptability threshold. Samples treated with 25 mg/L methylene blue showed the highest level of color alteration.

Effect of bleaching gel volume on color change and postoperative sensitivity: a randomized clinical study.

Although bleaching therapy is considered a dose-dependent treatment, the effect of the volume of product used is yet to be studied. This study thus aimed to evaluate the influence of bleaching gel volume on chromatic alteration and postoperative sensitivity. Thirty patients were selected and allocated into three groups; the lower canines were analyzed according to the volume of gel used: GI-0.025mL, GII-0.05mL, and GIII-0.10mL. Chromatic alteration analysis was performed using a portable digital spectrophotometer by calculating the ΔE, ΔE00, ΔL*, Δa*, and Δb* values and the whiteness index (WID). Spontaneous sensitivity was assessed using a questionnaire, and sensitivity was stimulated by thermo-sensory analysis. Analyses were conducted in five stages: baseline, after 1st, 2nd, and 3rd bleaching sessions, and 14days after the end. Data were analyzed using the two-way ANOVA test with repeated measures and Tukey's post hoc test (p < 0.05). It was observed that ΔE, ΔE00, and ΔL* were similar between groups at the end of the bleaching therapy; and the values of Δa*, Δb*, and WID were higher in the GIII group. For sensitivity, it was found that the GI was the one with the lowest values; o GII intermediate values; while the GIII group presents the highest values of spontaneous and stimulated sensitivity. Gel volume influenced the response to bleaching and significantly influenced the spontaneous sensitivity and cold stimulus. The amount of bleaching gel used during therapy is key to both the response to color change and postoperative sensitivity.