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Spectral Analysis

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https://www.readbyqxmd.com/read/29149695/rheo-optical-near-infrared-nir-spectroscopy-study-of-partially-miscible-polymer-blend-of-polymethyl-methacrylate-pmma-and-polyethylene-glycol-peg
#1
Hideyuki Shinzawa, Junji Mizukado
Tensile deformations of a partially miscible blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG) is studied by a rheo-optical characterization near-infrared (NIR) technique to probe deformation behavior during tensile deformation. Sets of NIR spectra of the polymer samples were collected by using an acousto-optic tunable filter (AOTF) NIR spectrometer coupled with a tensile testing machine as an excitation device. While deformations of the samples were readily captured as strain-dependent NIR spectra, the entire feature of the spectra was overwhelmed with the baseline fluctuation induced by the decrease in the sample thickness and subsequent change in the light scattering...
November 11, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29148728/neutral-luminescent-metal-organic-frameworks-structural-diversification-photophysical-properties-and-sensing-applications
#2
Gouri Chakraborty, Sanjay K Mandal
Utilizing flexible bis(tridentate)polypyridyl ligands, the two new luminescent 2D metal organic frameworks {Zn2(tpbn)(2,6-NDC)2}n (1) and {[Zn2(tphn)(2,6-NDC)2]·4H2O}n (2), where tpbn = N,N',N″,N‴-tetrakis(2-pyridylmethyl)-1,4-diaminobutane, tphn = N,N',N″,N‴-tetrakis(2-pyridylmethyl)-1,6-diaminohexane, and 2,6-H2NDC = 2,6-naphthalenedicarboxylic acid, have been isolated in good yields under solvothermal conditions. Their solid-state molecular structures have been determined by single-crystal X-ray diffractometry...
November 17, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29148032/secondary-glaucoma-in-uveitis-comparison-of-the-optic-nerve-head-morphology-among-a-nonmydriatic-fundus-camera-hrt-and-sd-oct
#3
Milena Pahlitzsch, Matthias K J Klamann, Saskia Jacob, Carl Erb, Sibylle Winterhalter, Necip Torun, Anna-Karina B Maier, Eckart Bertelmann
PURPOSE: To assess the correlation between the disc damage likelihood scale (DDLS) objectively measured by a nonmydriatic fundus camera, confocal laser scanning ophthalmoscopy (HRT3), and spectral-domain optical coherence tomography (SD-OCT) in uveitic glaucoma. METHODS: A total of 59 patients with uveitic glaucoma (21 female, 38 male; mean age 56.8 ± 18.7 years) were included in this prospective cross-sectional study. All patients were measured by the Kowa Nonmyd WX 3D camera (2D/3D nonmydriatic retinal camera, Kowa Company), the HRT3 (Heidelberg Engineering), and SD-OCT (Carl Zeiss Meditec) by one examiner on the same day...
November 4, 2017: European Journal of Ophthalmology
https://www.readbyqxmd.com/read/29148030/incidence-and-quantitative-analysis-of-dissociated-optic-nerve-fiber-layer-appearance-real-loss-of-retinal-nerve-fiber-layer
#4
Yoon J Kim, Kyoung S Lee, Soo G Joe, June-Gone Kim
PURPOSE: To assess the association between appearance of dissociated optic nerve fiber layer (DONFL) after internal limiting membrane (ILM) peeling and changes in the macular nerve fiber layer (NFL) area by spectral-domain optical coherence tomography (SD-OCT). METHODS: This study included 132 consecutive patients who had successfully undergone vitrectomy with ILM peeling for idiopathic epiretinal membrane or macular holes and had been followed up for ≥6 months...
November 4, 2017: European Journal of Ophthalmology
https://www.readbyqxmd.com/read/29147852/enhanced-peptide-detection-toward-single-neuron-proteomics-by-reversed-phase-fractionation-capillary-electrophoresis-mass-spectrometry
#5
Sam B Choi, Camille Lombard-Banek, Pablo Muñoz-LLancao, M Chiara Manzini, Peter Nemes
The ability to detect peptides and proteins in single cells is vital for understanding cell heterogeneity in the nervous system. Capillary electrophoresis (CE) nanoelectrospray ionization (nanoESI) provides high-resolution mass spectrometry (HRMS) with trace-level sensitivity, but compressed separation during CE challenges protein identification by tandem HRMS with limited MS/MS duty cycle. Here, we supplemented ultrasensitive CE-nanoESI-HRMS with reversed-phase (RP) fractionation to enhance identifications from protein digest amounts that approximate to a few mammalian neurons...
November 16, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/29146399/label-free-discrimination-analysis-of-de-differentiated-vascular-smooth-muscle-cells-mesenchymal-stem-cells-and-their-vascular-and-osteogenic-progeny-using-vibrational-spectroscopy
#6
Claire Molony, Jennifer McIntyre, Adrian Maguire, Roya Hakimjavadi, Denise Burtenshaw, Gillian Casey, Mariana Di Luca, Bryan Hennelly, Hugh J Byrne, Paul A Cahill
The accumulation of vascular smooth muscle (SMC)-like cells and stem cell-derived myogenic and osteogenic progeny contributes significantly to arteriosclerotic disease. This study established whether label-free vibrational spectroscopy can discriminate de-differentiated 'synthetic' SMCs from undifferentiated stem cells and their myogenic and osteogenic progeny in vitro, compared with conventional immunocytochemical and genetic analyses. TGF-β1- and Jagged1-induced myogenic differentiation of CD44(+)mesenchymal stem cells was confirmed in vitro by immunocytochemical analysis of specific SMC differentiation marker expression (α-actin, calponin and myosin heavy chain 11), an epigenetic histone mark (H3K4me2) at the myosin heavy chain 11 locus, promoter transactivation and mRNA transcript levels...
November 13, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29146353/handheld-nir-device-a-non-targeted-approach-to-assess-authenticity-of-fish-fillets-and-patties
#7
Silvia Grassi, Ernestina Casiraghi, Cristina Alamprese
This study evaluates the reliability of a handheld NIR device in distinguishing fillets and patties of Atlantic cod (n = 80) from those of haddock (n = 90), in comparison with a FT-NIR benchtop spectrometer. The authentication issue was faced by Linear Discriminant Analysis (LDA) and Soft Independent Modelling of Class Analogy (SIMCA), pre-treating spectral data with different algorithms, and validating models both internally and externally. The best LDA models gave 100% correct classification in prediction...
March 15, 2018: Food Chemistry
https://www.readbyqxmd.com/read/29144417/fast-low-cost-and-non-destructive-physico-chemical-analysis-of-virgin-olive-oils-using-near-infrared-reflectance-spectroscopy
#8
Ana Garrido-Varo, María-Teresa Sánchez, María-José De la Haba, Irina Torres, Dolores Pérez-Marín
Near-Infrared (NIR) Spectroscopy was used for the non-destructive assessment of physico-chemical quality parameters in olive oil. At the same time, the influence of the sample presentation mode (spinning versus static cup) was evaluated using two spectrophotometers with similar optical characteristics. A total of 478 olive oil samples were used to develop calibration models, testing various spectral signal pre-treatments. The models obtained by applying MPLS regression to spectroscopic data yielded promising results for olive oil quality measurements, particularly for acidity, the peroxide index and alkyl and ethyl ester content...
November 16, 2017: Sensors
https://www.readbyqxmd.com/read/29143877/ft-mir-and-nir-spectral-data-fusion-a-synergetic-strategy-for-the-geographical-traceability-of-panax-notoginseng
#9
Yun Li, Jin-Yu Zhang, Yuan-Zhong Wang
Three data fusion strategies (low-llevel, mid-llevel, and high-llevel) combined with a multivariate classification algorithm (random forest, RF) were applied to authenticate the geographical origins of Panax notoginseng collected from five regions of Yunnan province in China. In low-level fusion, the original data from two spectra (Fourier transform mid-IR spectrum and near-IR spectrum) were directly concatenated into a new matrix, which then was applied for the classification. Mid-level fusion was the strategy that inputted variables extracted from the spectral data into an RF classification model...
November 16, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29143837/development-of-a-label-free-raman-imaging-technique-for-differentiation-of-malaria-parasite-infected-from-non-infected-tissue
#10
Laura Frame, James Brewer, Rebecca Lee, Karen Faulds, Duncan Graham
During malarial infection, the host uses the spleen to clear the malaria parasites, however, the parasites have evolved the ability to bind to endothelial receptors in blood vessels of tissues to avoid removal, known as sequestration, and this is largely responsible for the symptoms and severity of infection. So a technique which could non-invasively diagnose tissue burden could be utilised as an aid for localised malaria diagnosis within tissue. Raman spectroscopy is a label-free imaging technique and can provide unique and chemically specific Raman 'fingerprint' spectrum of biological samples such as tissue...
November 16, 2017: Analyst
https://www.readbyqxmd.com/read/29143537/camphor-sulphonic-acid-mediated-quantitative-1-3-diol-protection-of-major-labdane-diterpenes-isolated-from-andrographis-paniculata
#11
Venu Sharma, Kamal K Kapoor, Debaraj Mukherjee, Vivek K Gupta, Manoj K Dhar, Sanjana Kaul
Phytochemical survey of the methanol extract of the dried aerial parts of Andrographis paniculata led to the isolation of major labdane diterpenes, namely 14-deoxy-11,12-didehydroandrographolide, andrographolide and neoandrographolide. Andrographolide was found to be the major phytoconstituent of the plant which was biologically active. For better physiochemical characteristics and bioefficacy, andrographolide is subjected to semi-synthetic modifications. However, presence of several free hydroxyl groups associated with this molecule make it quite polar and poorly soluble in many organic solvents and hence unsuitable for synthetic modifications...
November 16, 2017: Natural Product Research
https://www.readbyqxmd.com/read/29142422/chemotaxonomic-diversity-of-three-ficus-species-their-discrimination-using-chemometric-analysis-and-their-role-in-combating-oxidative-stress
#12
Nawal Al-Musayeib, Sherif S Ebada, Haidy A Gad, Fadia S Youssef, Mohamed Lotfy Ashour
Background: Genus Ficus (Moraceae) constitutes more than 850 species and about 2000 varieties and it acts as a golden mine that could afford effective and safe remedies combating many health disorders. Objectives: Discrimination of Ficus cordata, Ficus ingens, and Ficus palmata using chemometric analysis and assessment of their role in combating oxidative stress. Materials and Methods: Phytochemical profiling of the methanol extracts of the three Ficus species and their successive fractions was performed using high-performance liquid chromatography/electrospray ionization mass spectrometry...
October 2017: Pharmacognosy Magazine
https://www.readbyqxmd.com/read/29142266/hyperspectral-raman-imaging-of-neuritic-plaques-and-neurofibrillary-tangles-in-brain-tissue-from-alzheimer-s-disease-patients
#13
Ralph Michael, Aufried Lenferink, Gijs F J M Vrensen, Ellen Gelpi, Rafael I Barraquer, Cees Otto
Neuritic plaques and neurofibrillary tangles are crucial morphological criteria for the definite diagnosis of Alzheimer's disease. We evaluated 12 unstained frontal cortex and hippocampus samples from 3 brain donors with Alzheimer's disease and 1 control with hyperspectral Raman microscopy on samples of 30 × 30 µm. Data matrices of 64 × 64 pixels were used to quantify different tissue components including proteins, lipids, water and beta-sheets for imaging at 0.47 µm spatial resolution. Hierarchical cluster analysis was performed to visualize regions with high Raman spectral similarities...
November 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29141722/spatio-temporal-dynamics-of-asymptomatic-malaria-bridging-the-gap-between-annual-malaria-resurgences-in-a-sahelian-environment
#14
Drissa Coulibaly, Mark A Travassos, Youssouf Tolo, Matthew B Laurens, Abdoulaye K Kone, Karim Traore, Mody Sissoko, Amadou Niangaly, Issa Diarra, Modibo Daou, Boureima Guindo, Stanislas Rebaudet, Bourema Kouriba, Nadine Dessay, Renaud Piarroux, Christopher V Plowe, Ogobara K Doumbo, Mahamadou A Thera, Jean Gaudart
In areas of seasonal malaria transmission, the incidence rate of malaria infection is presumed to be near zero at the end of the dry season. Asymptomatic individuals may constitute a major parasite reservoir during this time. We conducted a longitudinal analysis of the spatio-temporal distribution of clinical malaria and asymptomatic parasitemia over time in a Malian town to highlight these malaria transmission dynamics. For a cohort of 300 rural children followed over 2009-2014, periodicity and phase shift between malaria and rainfall were determined by spectral analysis...
October 30, 2017: American Journal of Tropical Medicine and Hygiene
https://www.readbyqxmd.com/read/29141595/eeg-dynamical-correlates-of-focal-and-diffuse-causes-of-coma
#15
MohammadMehdi Kafashan, Shoko Ryu, Mitchell J Hargis, Osvaldo Laurido-Soto, Debra E Roberts, Akshay Thontakudi, Lawrence Eisenman, Terrance T Kummer, ShiNung Ching
BACKGROUND: Rapidly determining the causes of a depressed level of consciousness (DLOC) including coma is a common clinical challenge. Quantitative analysis of the electroencephalogram (EEG) has the potential to improve DLOC assessment by providing readily deployable, temporally detailed characterization of brain activity in such patients. While used commonly for seizure detection, EEG-based assessment of DLOC etiology is less well-established. As a first step towards etiological diagnosis, we sought to distinguish focal and diffuse causes of DLOC through assessment of temporal dynamics within EEG signals...
November 15, 2017: BMC Neurology
https://www.readbyqxmd.com/read/29140363/snapshot-second-harmonic-generation-polarimeter-based-on-spectral-analysis
#16
Matthieu Dubreuil, Sylvain Rivet, Yann Le Grand
A new high-speed second-harmonic generation (SHG) polarimetric method is reported. It is based on the spectral analysis of the SHG radiation emitted by a nonlinear medium excited with circularly polarized femtosecond laser pulses. The setup uses only passive components for polarization encoding and a fast spectrometer for spectral analysis. The method is validated on a z-cut quartz plate, then on a collagen-rich biological tissue with a view to single image polarization-resolved SHG microscopy.
November 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/29140316/hybrid-system-for-in-vivo-epifluorescence-and-4d-optoacoustic-imaging
#17
Zhenyue Chen, Xosé Luis Deán-Ben, Sven Gottschalk, Daniel Razansky
Epifluorescence imaging is widely used in cell and molecular biology due to its excellent sensitivity, contrast, and ease of implementation. Optoacoustic imaging has been shown to deliver a highly complementary and unique set of capabilities for biological discovery, such as high spatial resolution in noninvasive deep tissue observations, fast volumetric imaging capacity, and spectrally enriched contrast. In this Letter, we report on a hybrid system combining planar fluorescence and real-time volumetric four-dimensional optoacoustic imaging by means of a fiberscope integrated within a handheld hemispherical ultrasound detection array...
November 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/29140259/ramanomics-new-omics-disciplines-using-micro-raman-spectrometry-with-biomolecular-component-analysis-for-molecular-profiling-of-biological-structures
#18
REVIEW
Andrey N Kuzmin, Artem Pliss, Paras N Prasad
Modern instrumentation for Raman microspectroscopy and current techniques in analysis of spectral data provide new opportunities to study molecular interactions and dynamics at subcellular levels in biological systems. Implementation of biomolecular component analysis (BCA) to microRaman spectrometry provides basis for the emergence of Ramanomics, a new biosensing discipline with unprecedented capabilities to measure concentrations of distinct biomolecular groups in live cells and organelles. Here we review the combined use of microRaman-BCA techniques to probe absolute concentrations of proteins, DNA, RNA and lipids in single organelles of live cells...
November 15, 2017: Biosensors
https://www.readbyqxmd.com/read/29139244/raman-exfoliative-cytology-for-oral-precancer-diagnosis
#19
Aditi Sahu, Poonam Gera, Venkatesh Pai, Abhishek Dubey, Gunjan Tyagi, Mandavi Waghmare, Sandeep Pagare, Manoj Mahimkar, C Murali Krishna
Oral premalignant lesions (OPLs) such as leukoplakia, erythroplakia, and oral submucous fibrosis, often precede oral cancer. Screening and management of these premalignant conditions can improve prognosis. Raman spectroscopy has previously demonstrated potential in the diagnosis of oral premalignant conditions (in vivo), detected viral infection, and identified cancer in both oral and cervical exfoliated cells (ex vivo). The potential of Raman exfoliative cytology (REC) in identifying premalignant conditions was investigated...
November 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29138527/longitudinal-analysis-of-mouse-sdoct-volumes
#20
Bhavna J Antony, Aaron Carass, Andrew Lang, Byung-Jin Kim, Donald J Zack, Jerry L Prince
Spectral-domain optical coherence tomography (SDOCT), in addition to its routine clinical use in the diagnosis of ocular diseases, has begun to find increasing use in animal studies. Animal models are frequently used to study disease mechanisms as well as to test drug efficacy. In particular, SDOCT provides the ability to study animals longitudinally and non-invasively over long periods of time. However, the lack of anatomical landmarks makes the longitudinal scan acquisition prone to inconsistencies in orientation...
February 11, 2017: Proceedings of SPIE
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