查看更多>>摘要：Using Vis-NIR spectroscopy to distinguish gestational sac from other abdominal tissues is the key to diagnosing female rabbits' pregnancy by optical means. This study aims to demonstrate the gestational sac and other abdominal tissues (hair, skin, breast, muscle, cecum, small intestine) of rabbits can be identified using Vis-NIR spectroscopy in vitro. These tissues' raw NIR spectra were recorded in the Vis-NIR range (490-940 nm) with interactive mode. The raw spectra of tissues were analyzed by the principal component analysis (PCA), and were pre-processed using five spectral pre-processing techniques (moving average filter (MF), De-trending (DT), first-order derivative (D1), Multivariate scattering correction (MSC), and standard normal variate (SNV)) to reduce signal noises. The raw and pre-processed spectra were classified using partial least squares discrimination analysis (PLS-DA). Two-way and multi-way PLS-DA model was conducted to understand the classification of each tissue from the gestational sac and to understand the classification of all tissues from the gestational sac, respectively. SNV-PLS-DA model had the best performance, and its multi-way accuracy (Ac), determination coefficients (R-2), and Q(2) were 0.89, 0.91, 0.77, respectively. The successive projection algorithm (SPA) and competitive adaptive reweighted sampling (CARS) were used to select characteristic wavelengths (CWs). The SNV-SPA-PLS-DA model with eighteen CWs was better than the SNV-CARS-PLS-DA model. The results showed that Vis-NIR spectroscopy technology combined with PLS-DA could discriminate the gestational sac from the abdominal tissues. This study may help develop an optical diagnosis system for pregnant rabbits. (C) 2022 Elsevier B.V. All rights reserved.
Unterberger, Seraphin HubertLackner, RomanWieser, Martin
9页
查看更多>>摘要：In the context of the circular economy, the sorting process during recycling of polymers is essential as regards the efficiency of the process itself and the quality of the so-obtained recycled materials. In this paper, the application of Hyperspectral Imaging (HSI) is proposed for this purpose, providing additional insight into the state of aging and the polymer quality. The underlying study comprises HSI in the wavelength range of 1115-1678 nm considering artificially aged Styrene-Butadiene-Styrene (SBS), where aging is performed for 2, 5, 10, 15 and 20 days in a forced-draft oven at a temperature of 105 degrees C. The obtained HSI spectra are normalized using the Standard Normal Variate (SNV) method, with the normalized spectra as well as their first and second derivative entering the modeling attempt for SBS aging. For the latter, different partial least squares regression (PLSR) models are evaluated, where the original spectra achieved a correlation of R-2 = 0.94 and a root mean squared error of prediction (RMSEP) of 1.83 days, showing the suitability of HSI for the proper identification of the state of aging of SBS and its potential use for other polymers. (C) 2022 The Author(s). Published by Elsevier B.V.
Dou, TianyiErmolenkov, AlexeiRich, Brian T.Donaldson, Taylor G....
7页
查看更多>>摘要：Ticks are blood-feeding parasites that vector a large number of pathogens of medical and veterinary importance. There are strong connections between tick and pathogen species. Timely detection of certain tick species on cattle can cease the spread of numerous devastating diseases such as Bovine babiesiosis and anaplasmosis. Detection of ticks is currently performed by slow and laborious scout-based inspection of cattle. In this study, we investigated the possibility of identification of tick species (Ixodidae) based on spectroscopic signatures of their feces. We collected Raman spectra from individual grains of feces of seven different species of ticks. Our results show that Raman spectroscopy (RS) allows for highly accurate (above 90%) differentiation between tick species. Furthermore, RS can be used to predict the tick developmental stage and differentiate between nymphs, meta-nymphs and adult ticks. We have also demonstrated that diagnostics of tick species present on cattle can be achieved using a hand-held Raman spectrometer. These findings show that RS can be used for non-invasive, non-destructive and confirmatory on-site analysis of tick species present on cattle. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Cyanide anion is a ubiquitous chemical substance in the ecosystem, however, human daily life is severely threatened by its toxicity at any time. In this paper, a novel colorimetric and turn-on chemosensor 4-(4(2,2-difluoro-6-methyl-2H-1,3,2-dioxaborinin-4-yl)buta-1,3-dien-1-yl)-N,N-dimethylaniline (NBF) for detecting cyanide anion was synthesized based on the 4-(dimethylamino)cinnamaldehyde and beta-diketone difluoroboron complex. This fluorescent probe exhibited excellent spectroscopy properties such as large stokes shift, long emission wavelength, and good sensitivity. The detection limit of NBF towards cyanide ion was determined as low as 2.23 mu M. Additionally, the detection mechanism towards cyanide ion was confirmed to be the nucleophilic addition interaction by high resolution mass spectrum (HRMS), H-1 Nuclear Magnetic Resonance (NMR) titration, and quantum chemistry theory calculation. In addition, the probe NBF had been successfully utilized in detecting cyanide ions in water and food samples as well as imaging in the biological system, which broadened its practical application prospects. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Acute myeloid leukemia (AML) is a common hematologic malignancy. To this day, diagnose of AML and its genetic mutation still rely on invasive and time-consuming methods. In this study, 222 plasma samples were collected to discuss the performance of surface-enhanced Raman spectroscopy (SERS) to discriminate AML subtype acute promyelocytic leukemia and acute monocytic leukemia based on plasma. The Ag nanoparticles-based SERS technique was used to explore the biochemical differences among different AML subtypes. With the help of powerful supervised and unsupervised algorithms, the performance using the whole spectra and band intensities was confirmed to identify different subtypes of AML. The results demonstrated the intensities of several bands and band-intensity ratios were significantly different between groups, thus related to the discrimination of several AML subtypes and control. Combining indexes of band-intensity ratios, the result of multi-indexes ROC has excellent performance in differentiating AML patient with healthy control. Our work demonstrated the great potential of SERS technique as a rapid and micro detection method in clinical laboratory field, it's a new and powerful tool for analyzing human blood plasma. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：In this work, herein we report the synthesis, structural characterization and in vitro cytotoxic evaluation of two mixed Co(II)/Ni(II)-nalidixic acid-bipyridyl complexes (1 and 2). The structural analysis of metal complexes 1 and 2 was carried out by analytical and multispectroscopic techniques (FT-IR, UV-vis, EPR, sXRD). The crystallographic details of complexes 1 and 2 revealed a monoclinic crystal system with P21/c space group. DFT studies of complexes were performed to get electronic structure and localization of HOMO and LUMO electron densities. Hirshfeld surface analysis of metal complexes 1 and 2 was employed to understand the various intermolecular interactions (C-H center dot center dot center dot O, N-H center dot center dot center dot H and O-H center dot center dot center dot O) that define the stability of crystal lattice structures. The comparative interaction studies of complex 1 and complex 2 with DNA/BSA were performed by diverse multispectroscopic and analytical techniques to evaluate their chemotherapeutic potential. The magnitude of the DNA binding propensity and binding mode was verified by calculating K-b, K and K-sv values. Higher binding affinity was observed in case of complex 2 via intercalative mode. Furthermore, the cytotoxic assessment of complexes 1 and 2 was examined against MDA-MB-231 (triple negative human breast cancer cell line) and HepG2 (liver carcinoma cell line) employing MTT assay which revealed remarkably effecient and specific cytotoxic activity of complex 2. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Preservatives are universally used in synergistic combination to enhance antimicrobial effect. Identify compositions and quantify components of preservatives are crucial steps in quality monitoring to guarantee merchandise safety. In the work, three most common preservatives, sorbic acid, potassium sorbate and sodium benzoate, are deliberately mixed in pairs with different mass ratios, which are supposed to be the "unknown" multicomponent systems and measured by terahertz (THz) time-domain spectroscopy. Subsequently, three major challenges have been accomplished by machine learning methods in this work. The singular value decomposition (SVD) effectively obtains the number of components in mixed preservatives. Then, the component spectra are successfully extracted by non-negative matrix factorization (NMF) and self-modeling mixture analysis (SMMA), which match well with the measured THz spectra of pure reagents. Moreover, the support vector machine for regression (SVR) designed an underlying model to the target components and simultaneously identify contents of each individual component in validation mixtures with decision coefficient R-2 = 0.989. By taking advantages of the fingerprint-based THz technique and machine learning methods, our approach has been demonstrated the great potential to be served as a useful strategy for detecting preservative mixtures in practical applications. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The present study applied steady-state fluorescence, UV-Vis spectrophotometry, molecular docking studies, and circular dichroism (CD) to investigate the interaction of naringenin with lysozyme in an aqueous medium. The UV-Vis measurement indicated the changes in lysozyme secondary and tertiary structure change as a function of the concentration of naringenin. Naringenin could be used to turn the static quenching mechanism into the intrinsic fluorescence of lysozyme. The negative amount of Gibbs free energy (Delta G degrees) suggested that the binding operation was spontaneous. Fluorescence studies also demonstrated the changes occurring in the Trp microenvironment upon the concatenation into lysozyme. Analysis of thermodynamic parameters also revealed that hydrophobic forces played a fundamental role in determining the complex stability; this was consistent with the previous modeling studies. Circular dichroism also suggested that the alpha-helicity of lysozyme was enhanced as ligand was bound. Naringenin inhibited lysozyme enzymatic activity, displaying its affinity with the lysozyme active site. Further, molecular docking studies demonstrated that naringenin could bind to both residues essential for catalytic activity in the proximity of Trp 62 and Trp 63. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Fluoride (F-) and Al3+ are two common ions existing in drinking water and natural water bodies. Excessive intake of F- can lead to serious health issues such as fluorosis and bone diseases while accumulated consumption of Al3+ may cause neurotoxicity-based diseases. Developing a fast, reliable, and sensitive sensor for visually detecting both F- and Al3+ is of great significance. In the present work, a ratiometric fluorescence sensor was constructed by incorporating rhodamine B (RhB) in situ into a zirconium-based metal-organic framework, UiO-66-NH2. The obtained nanocomposite UiO-66NH(2)@RhB exhibited similar octahedral structure to UiO-66-NH2 with high BET surface area, and showed two emission peaks at 450 nm and 585 nm. The blue fluorescence from UiO-66-NH2 was enhanced by the addition of F- while subsequent Al3+ addition diminished the increased fluorescence intensity, and the red emission from RhB as the reference remained unchangeable to improve the detection precision. Under optimal conditions, detection of limits as low as 1.55 mu M for F- and 0.54 mu M for Al3+ in aqueous solution were achieved with good selectivity. High recoveries in drinking water samples were also acquired, showing potential applications of this ratiometric fluorescence sensor for practical evaluation of F- and Al3+. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Early detection and monitoring of any abnormality of Hemoglobin (Hb) concentration in whole blood samples are important as this may be related to anemia, leukemia, dengue, etc. To facilitate quantitative detection and to monitor the hemoglobin level in the blood, we attempt to develop a low-cost, portable point of care (POC) device based on the spectrophotometric principle. Optical sensitivities of carbon quantum dots (CDs) are found to be highly responsive, while there is a selective reaction between Hb and reduced form of Methylene Blue (MBred). The interaction of Hb, MBred, and CDs is delineated using UV-Visible (UV-Vis) spectroscopy. CDs have a characteristic UV-Vis peak at similar to 347 nm, and it shows a gradual increase in intensity with a slight red shift (similar to 355 nm) on the progressive increase in Hb concentration. Simultaneously, the colorless MBred is oxidized to its blue oxidized form MBox and its characteristic peak starts reappearing at similar to 663 nm. These responses are exploited to quantify Hb concentration with a limit of detection (LOD) as low as similar to 2 g dL(-1) in a developed POC device, and the results are validated with the clinical data obtained from a local hospital with reasonably good agreement. This photometric detection approach can be adopted for other quantitative biosensors. (C) 2022 Elsevier B.V. All rights reserved.
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