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Spectral Analysis

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https://www.readbyqxmd.com/read/28550814/determination-of-equilibrium-structures-of-bromothymol-blue-revealed-by-using-quantum-chemistry-with-an-aid-of-multivariate-analysis-of-electronic-absorption-spectra
#1
Toru Shimada, Takeshi Hasegawa
The pH dependent chemical structures of bromothymol blue (BTB), which have long been under controversy, are determined by employing a combined technique of multivariate analysis of electronic absorption spectra and quantum chemistry. Principle component analysis (PCA) of the pH dependent spectra apparently reveals that only two chemical species are adequate to fully account for the color changes, with which the spectral decomposition is readily performed by using augmented alternative least-squares (ALS) regression analysis...
May 19, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28549848/relationship-between-visual-acuity-and-retinal-thickness-during-anti-vascular-endothelial-growth-factor-therapy-for-retinal-diseases
#2
William C Ou, David M Brown, John F Payne, Charles C Wykoff
PURPOSE: Investigate the relationship between best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in eyes receiving ranibizumab for three common retinal diseases. DESIGN: Retrospective analysis of clinical trial data METHODS: Early Treatment Diabetic Retinopathy Study BCVA and spectral-domain optical coherence tomography measured CRT of 387 eyes of 345 patients enrolled in six prospective clinical trials for management of neovascular age-related macular degeneration (AMD), diabetic macular edema (DME), and retinal vein occlusion (RVO) were evaluated by Pearson correlation and linear regression...
May 23, 2017: American Journal of Ophthalmology
https://www.readbyqxmd.com/read/28549518/ganglion-cell-inner-plexiform-layer-change-detected-by-optical-coherence-tomography-indicates-progression-in-advanced-glaucoma
#3
Joong Won Shin, Kyung Rim Sung, Gary C Lee, Mary K Durbin, Daniel Cheng
PURPOSE: To examine the performance of Guided Progression Analysis (GPA; Carl Zeiss Meditec, Dublin, CA) in spectral-domain optical coherence tomography (OCT) in detecting progressive thinning of ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) in glaucoma. DESIGN: Longitudinal, observational study. PARTICIPANTS: A total of 196 eyes of 123 primary open-angle glaucoma patients (mean follow-up, 5.0 years). METHODS: Macular GCIPL and peripapillary RNFL thicknesses were measured by Cirrus HD-OCT (Zeiss, Dublin, CA), and progressive GCIPL and RNFL thinning were assessed by GPA...
May 23, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28546841/the-effect-of-cyclodextrin-complexation-on-the-solubility-and-photostability-of-nerolidol-as-pure-compound-and-as-main-constituent-of-cabreuva-essential-oil
#4
Joyce Azzi, Pierre-Edouard Danjou, David Landy, Steven Ruellan, Lizette Auezova, Hélène Greige-Gerges, Sophie Fourmentin
Nerolidol (Ner), a major component of many plant essential oils, is known for its various biological properties. However, the low solubility of Ner in water and its susceptibility to degradation limit its application. The aim of our study was to improve the solubility and photostability of Ner through its encapsulation in different cyclodextrins (CDs). The formation constants of cis-, trans-Ner and their commercial mixture with various CDs (α-CD, β-CD, γ-CD, HP-β-CD, RAMEB, CRYSMEB and SBE-β-CD) were determined by phase solubility studies and confirmed by the spectral displacement UV-visible method...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28546285/anti-inflammatory-effects-and-mechanisms-of-vagal-nerve-stimulation-combined-with-electroacupuncture-in-a-rodent-model-of-tnbs-induced-colitis
#5
Haifeng Jin, Jie Guo, Jiemin Liu, Bin Lyu, Robert D Foreman, Jieyun Yin, Zhaohong Shi, Jiande Dz Chen
The purpose of this study was to determine effects and mechanisms of vagal nerve stimulation (VNS) and additive effects of electroacupuncture (EA) on colonic inflammation in a rodent model of IBD. Chronic inflammation in rats was induced by intrarectal TNBS (2,4,6-Trinitrobenzenesulfonic acid). The rats were then treated with sham-ES (electrical stimulation), VNS or VNS+EA for 3 weeks. Inflammatory responses were assessed by disease activity index (DAI), macroscopic scores and histological scores of colonic tissues, and plasma levels of TNF-α, IL-1β and IL-6, myeloperoxidase (MPO) activity of colonic tissues...
May 25, 2017: American Journal of Physiology. Gastrointestinal and Liver Physiology
https://www.readbyqxmd.com/read/28545553/pigment-fingerprint-profile-during-extractive-fermentation-with-monascus-anka-gim-3-592
#6
Kan Shi, Rui Tang, Tao Huang, Lu Wang, Zhenqiang Wu
BACKGROUND: Traditional submerged fermentation mainly accumulates intracellular orange pigments with absorption maxima at 470 nm, whereas extractive fermentation of Monascus spp. with Triton X-100 can promote the export of intracellular pigments to extracellular broth, mainly obtaining extracellular yellow pigments with absorption maxima at approximately 410 nm. In this study, a strain of Monascus (M. anka GIM 3.592) that produces high yields of pigments was employed to investigate the differences in pigment fingerprint profiles between submerged and extractive fermentations...
May 25, 2017: BMC Biotechnology
https://www.readbyqxmd.com/read/28545121/measurement-of-macular-structure-function-relationships-using-spectral-domain-optical-coherence-tomography-sd-oct-and-pattern-electroretinograms-perg
#7
Keunheung Park, Jinmi Kim, Jiwoong Lee
BACKGROUND: Retinal ganglion cell (RGC) death is a common cause of loss of vision during glaucoma. Pattern electroretinogram (PERG) is an objective measure of the central retinal function that correlates with macular GCL thickness. The aim of this study is to determine possible relationships between the N95 amplitude of pattern electroretinogram (PERGamp) and macular ganglion cell/inner plexiform layer thickness (GCIPLT). METHODS AND FINDINGS: This was a retrospective and comparative study including 74 glaucoma patients (44 early stage and 30 advanced stage cases) and 66 normal control subjects...
2017: PloS One
https://www.readbyqxmd.com/read/28544745/fs-laser-ablation-of-teeth-is-temperature-limited-and-provides-information-about-the-ablated-components
#8
Rebeca Ferraz de Menezes, Catherine Malinda Harvey, Marleny Elizabeth Márquez de Martínez Gerbi, Zachary J Smith, Dan Smith, Juan C Ivaldi, Alton Phillips, James W Chan, Sebastian Wachsmann-Hogiu
The goal of this work is to investigate the thermal effects of femtosecond laser (fs-laser) ablation for the removal of carious dental tissue. Additional studies identify different tooth tissues through femtosecond laser induced breakdown spectroscopy (fsLIBS) for the development of a feedback loop that could be utilized during ablation in a clinical setting. Scanning Election Microscope (SEM) images reveal that minimal morphological damages are incurred at repetition rates below the carbonization threshold of each tooth tissue...
May 24, 2017: Journal of Biophotonics
https://www.readbyqxmd.com/read/28543988/absolute-minimal-sampling-of-homonuclear-2d-nmr-tocsy-spectra-for-high-throughput-applications-of-complex-mixtures
#9
Alexandar Hansen, Da-Wei Li, Cheng Wang, Rafael Bruschweiler
Modern applications of 2D NMR spectroscopy to diagnostic screening, metabolomics, quality control, and other high-throughput applications are often limited by the time-consuming sampling requirements along the indirect time domain t1. 2D Total Correlation Spectroscopy (TOCSY) provides unique spin-connectivity information for the analysis of a large number of compounds in complex mixtures, but standard methods typically require >100 t1-increments for an accurate spectral reconstruction, rendering these experiments ineffective for high-throughput applications...
May 23, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28543915/cross-sectional-correlation-between-hepatic-r2-and-proton-density-fat-fraction-pdff-in-children-with-hepatic-steatosis
#10
Adrija Mamidipalli, Gavin Hamilton, Paul Manning, Cheng William Hong, Charlie C Park, Tanya Wolfson, Jonathan Hooker, Elhamy Heba, Alexandra Schlein, Anthony Gamst, Janis Durelle, Melissa Paiz, Michael S Middleton, Jeffrey B Schwimmer, Claude B Sirlin
PURPOSE: To determine the relationship between hepatic proton density fat fraction (PDFF) and R2* in vivo. MATERIALS AND METHODS: In this Health Insurance Portability and Accountability Act (HIPAA)-compliant, Institutional Review Board (IRB)-approved, cross-sectional study, we conducted a secondary analysis of 3T magnetic resonance imaging (MRI) exams performed as part of prospective research studies in children in whom conditions associated with iron overload were excluded clinically...
May 25, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28541675/prediction-of-bond-vector-autocorrelation-functions-from-larmor-frequency-selective-order-parameter-analysis-of-nmr-relaxation-data
#11
Janet S Anderson, Griselda Hernandez, David M LeMaster
Protein molecular dynamics interpretation of the standard R1, R2 and heteronuclear NOE relaxation measurements has typically been limited to a single S(2) order parameter which is often insufficient to characterize the rich content of these NMR experiments. In the absence of exchange linebroadening, an optimized reduced spectral density analysis of these measurements can yield spectral density values at three distinct frequencies. Surprisingly, these three discrete spectral density values have proven to be sufficient for a Larmor frequency-selective order parameter analysis of the 223 methine and methylene H-C bonds of the B3 domain of Protein G (GB3) to accurately back-calculate the entire curve of the corresponding bond vector autocorrelation functions upon which the NMR relaxation behavior depends...
May 25, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28541266/retinochoroidal-anastomosis-associated-with-enhanced-s-cone-syndrome
#12
Jennyfer Zerbib, Rocio Blanco Garavito, Sylvie Gerber, Hassiba Oubraham, Anne Sikorav, Isabelle Audo, Josseline Kaplan, Jean-Michel Rozet, Eric H Souied
PURPOSE: To describe the phenotype and genotype of a 10-year-old boy affected with enhanced S-cone syndrome associated with neovascularization. METHODS: Fundus autofluorescence, fluorescein angiography, indocyanine green angiography, spectral domain optical coherence tomography, full-field electroretinogram and NR2E3 molecular testing were performed. RESULTS: Best-corrected visual acuity was measured as 20/32, right eye and 20/20, left eye...
May 22, 2017: Retinal Cases & Brief Reports
https://www.readbyqxmd.com/read/28540866/electrophysiological-signatures-of-atypical-intrinsic-brain-connectivity-networks-in-autism
#13
Guofa Shou, Matthew W Mosconi, Jun Wang, Lauren E Ethridge, John A Sweeney, Lei Ding
OBJECTIVE: Abnormal local and long-range brain connectivity have been widely reported in autism spectrum disorder (ASD), yet the nature of these abnormalities and their functional relevance at distinct cortical rhythms remains unknown. Investigations of intrinsic connectivity networks (ICNs) and their coherence across whole brain networks hold promise for determining whether patterns of functional connectivity abnormalities vary across frequencies and networks in ASD. In the present study, we aimed to probe atypical intrinsic brain connectivity networks in ASD from resting-state electroencephalography (EEG) data via characterizing the whole brain network...
May 25, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28540585/antibiofilm-activity-and-mode-of-action-of-dmso-alone-and-its-combination-with-afatinib-against-gram-negative-pathogens
#14
Mohd Fakharul Zaman Raja Yahya, Zazali Alias, Saiful Anuar Karsani
Biofilms are complex microbial communities that tend to attach to either biotic or abiotic surface. Enclosed in a self-produced extracellular polymeric substance (EPS) matrix, the biofilms often cause persistent infections. The objective of this study was to investigate the antibiofilm activity of dimethyl sulfoxide (DMSO) and afatinib against Gram-negative pathogens. Test microorganisms used in this study were Escherichia coli ATCC 1299, Pseudomonas aeruginosa ATCC 10145, and Salmonella typhimurium ATCC 14028...
May 24, 2017: Folia Microbiologica
https://www.readbyqxmd.com/read/28539599/callistemenonone-a-a-novel-dearomatic-dibenzofuran-type-acylphloroglucinol-with-antimicrobial-activity-from-callistemon-viminalis
#15
Yu-Qing Xiang, Hong-Xin Liu, Li-Yun Zhao, Zhi-Fang Xu, Hai-Bo Tan, Sheng-Xiang Qiu
A new acylphloroglucinol with a novel architecture including an unprecedented dearomatic dibenzofuran core, named callistemenonone A (1), was isolated from the leaves of Callistemon viminalis (Myrtaceae). The structure was fully characterized on the basis of extensive spectroscopic analysis, including UV, HRESIMS, as well as 1D and 2D NMR spectral data (HSQC, HMBC, and ROESY). The deduced structure represents the first example of a natural dibenzofuran with two phenyl moieties coupling through tertiary hydroxy and ketal carbons...
May 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28538978/the-characteristics-of-deep-optic-nerve-head-morphology-in-myopic-normal-tension-glaucoma
#16
Jong Chul Han, Eun Jung Lee, Si Bum Kim, Changwon Kee
Purpose: To investigate the relationship between axial length (AL) and deep optic nerve head (ONH) structure and to evaluate the characteristics of deep ONH structures in myopic normal tension glaucoma (NTG). Methods: The following parameters were assessed using spectral-domain optical coherence tomography (SD-OCT): externally oblique border tissue (EOBT) length, ONH tilt angle, optic canal (OC) obliqueness, and β-zone peripapillary atrophy (PPA). In addition, the angular location of the maximal value of each parameter and retinal nerve fiber layer (RNFL) defect were measured using infrared and red-free photos...
May 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28538724/applying-systems-level-spectral-imaging-and-analysis-to-reveal-the-organelle-interactome
#17
Alex M Valm, Sarah Cohen, Wesley R Legant, Justin Melunis, Uri Hershberg, Eric Wait, Andrew R Cohen, Michael W Davidson, Eric Betzig, Jennifer Lippincott-Schwartz
The organization of the eukaryotic cell into discrete membrane-bound organelles allows for the separation of incompatible biochemical processes, but the activities of these organelles must be coordinated. For example, lipid metabolism is distributed between the endoplasmic reticulum for lipid synthesis, lipid droplets for storage and transport, mitochondria and peroxisomes for β-oxidation, and lysosomes for lipid hydrolysis and recycling. It is increasingly recognized that organelle contacts have a vital role in diverse cellular functions...
May 24, 2017: Nature
https://www.readbyqxmd.com/read/28538191/assessment-of-hyperspectral-imaging-system-for-colour-measurement
#18
Damian K Chlebda, Anna Rogulska, Tomasz Łojewski
A novel technique of reflective spectroscopy, hyperspectral imaging (HSI), was used to develop a methodology for colour measurement, which is very important in the field of art conservation - especially in the analysis of documents. The major focus of this work is an examination of the repeatability and reproducibility of colour parameters calculated from the hyperspectral data. The study was performed with commercial colour standards and pen ink lines, corresponding to large and small-scale colour areas, respectively...
May 17, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28538102/effects-of-wet-blending-on-detection-of-melamine-in-spray-dried-lactose
#19
Betsy Jean Yakes, Marti M Bergana, Peter F Scholl, Magdi M Mossoba, Sanjeewa R Karunathilaka, Luke K Ackerman, Jason D Holton, Boyan Gao, Jeffrey C Moore
During the development of rapid screening methods to detect economic adulteration, spray-dried milk powders prepared by dissolving melamine in liquid milk exhibited an unexpected loss of characteristic melamine features in the NIR and Raman spectra. To further characterize this "wet-blending" phenomenon, spray-dried melamine and lactose samples were produced as a simplified model and investigated by near-infrared spectroscopy, Raman spectroscopy, 1H NMR, and DART-FTMS. In contrast to dry-blended samples, characteristic melamine bands in NIR and Raman spectra disappeared or shifted in wet-blended lactose-melamine samples...
May 24, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28537294/using-raman-spectroscopy-to-assess-hemoglobin-oxygenation-in-red-blood-cell-concentrate-an-objective-proxy-for-morphological-index-to-gauge-the-quality-of-stored-blood
#20
Chad G Atkins, H Georg Schulze, Deborah Chen, Dana V Devine, Michael W Blades, Robin F B Turner
Blood banking is an essential aspect of modern medical care. When red blood cells (RBCs) are stored, they become damaged by various chemical processes, such as accumulation of their own waste products and oxidative injury, among others. These processes lead to the development of the RBC storage lesion, a complex condition where the severity is reflected through the morphology of the stored cells. It was hypothesized that Raman spectroscopy could be used to monitor certain structural and compositional changes associated with such ageing effects and that a relationship between these features and traditional morphology (as measured using a morphology index) could be observed...
May 24, 2017: Analyst
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