146 research outputs found
Determination of sodium fatty acid in soap Formulation Using Fourier Transform Infrared (FTIR) spectroscopy and multivariate calibrations.
Fourier Transform Infrared (FTIR) spectroscopy using an attenuated total reflectance (ATR) accessory has been investigated as a method for the determination of sodium-fatty acid (sodium-FA) in soap formulations. Multivariate calibrations namely partial least squares regression (PLS) and principle component regression (PCR) were developed for the prediction of sodium-FA using spectral ranges on the basis of relevant IR absorption bands related to sodium-FA. The sodium-FA content in soap formulations was predicted accurately at wavenumbers of 1,570–1,550 cm−1, which is specific for RCOO− Na+ vibration. The PLS method was found to be a consistently better predictor when both PLS and principal component regression (PCR) analyses were used for quantification of sodium-FA. Furthermore, FTIR spectroscopy can be an alternative technique to American oil Chemist Society methods which use a titrimetric technique because FTIR offers rapid, easy sample preparation and is friendly to the environment
Antigenic cross-reactivity between severe acute respiratory syndrome-associated coronavirus and human coronaviruses 229E and OC43
Cross-reactivity between antibodies to different human coronaviruses (HCoVs) has not been systematically studied. By use of Western blot analysis, indirect immunofluorescence assay (IFA), and enzyme-linked immunosorbent assay (ELISA), antigenic cross-reactivity between severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) and 2 HCoVs (229E and OC43) was demonstrated in immunized animals and human serum. In 5 of 11 and 10 of 11 patients with SARS, paired serum samples showed a ≥4-fold increase in antibody titers against HCoV-229E and HCoV-OC43, respectively, by IFA. Overall, serum samples from convalescent patients who had SARS had a 1-way cross-reactivity with the 2 known HCoVs. Antigens of SARS-CoV and HCoV-OC43 were more cross-reactive than were those of SARS-CoV and HCoV-229E. © 2005 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio
Use of the SAW sensor electronic nose for detecting the adulteration of virgin coconut oil with RBD palm kernel olein.
An electronic nose (zNose™) was applied to the detection of adulteration of virgin coconut oil. The system, which is based on a surface acoustic wave sensor was used to generate a pattern of volatile compounds present in the samples. Virgin coconut oil was mixed with refined, bleached and deodorized palm kernel olein at a level of adulteration from 1 to 20% (wt/wt). Adulterant peaks were identified from the chromatogram profile and fitted to a curve using linear regression. The best relationship (R 2 = 0.91) was obtained between the peak tentatively identified as methyl dodecanoate and the percentage of palm kernel olein added. Pearson’s correlation coefficients (r) of 0.92 and 0.89 were obtained between adulterant peak methyl dodecanoate and of the iodine and peroxide values, respectively. Principal component analysis (PCA) was used to differentiate between pure and adulterated samples. The PCA provided good differentiation of samples with 74% of the variation accounted for by PC 1 and 17% accounted for by PC 2. Pure samples formed a separate cluster from all of the adulterated samples
DNA end recognition by the Mre11 nuclease dimer: insights into resection and repair of damaged DNA
The Mre11-Rad50-Nbs1 (MRN) complex plays important roles in sensing DNA damage, as well as in resecting and tethering DNA ends, and thus participates in double-strand break repair. An earlier structure of Mre11 bound to a short duplex DNA molecule suggested that each Mre11 in a dimer recognizes one DNA duplex to bridge two DNA ends at a short distance. Here, we provide an alternative DNA recognition model based on the structures of Methanococcus jannaschii Mre11 (MjMre11) bound to longer DNA molecules, which may more accurately reflect a broken chromosome. An extended stretch of B-form DNA asymmetrically runs across the whole dimer, with each end of this DNA molecule being recognized by an individual Mre11 monomer. DNA binding induces rigid-body rotation of the Mre11 dimer, which could facilitate melting of the DNA end and its juxtaposition to an active site of Mre11. The identified Mre11 interface binding DNA duplex ends is structurally conserved and shown to functionally contribute to efficient resection, non-homologous end joining, and tolerance to DNA-damaging agents when other resection enzymes are absent. Together, the structural, biochemical, and genetic findings presented here offer new insights into how Mre11 recognizes damaged DNA and facilitates DNA repair.X111513Ysciescopu
Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials
Recent years witnessed a rapid growth of interest of scientific and
engineering communities to thermal properties of materials. Carbon allotropes
and derivatives occupy a unique place in terms of their ability to conduct
heat. The room-temperature thermal conductivity of carbon materials span an
extraordinary large range - of over five orders of magnitude - from the lowest
in amorphous carbons to the highest in graphene and carbon nanotubes. I review
thermal and thermoelectric properties of carbon materials focusing on recent
results for graphene, carbon nanotubes and nanostructured carbon materials with
different degrees of disorder. A special attention is given to the unusual size
dependence of heat conduction in two-dimensional crystals and, specifically, in
graphene. I also describe prospects of applications of graphene and carbon
materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe
Loess plateau storage of northeastern Tibetan plateau-derived Yellow River sediment
Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river’s upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records
Application of FTIR spectroscopy for the determination of virgin coconut oil in binary mixtures with olive oil and palm oil.
Rapid Fourier transform infrared (FTIR) spectroscopy combined with attenuated total reflectance (ATR) was applied for quantitative analysis of virgin coconut oil (VCO) in binary mixtures with olive oil (OO) and palm oil (PO). The spectral bands correlated with VCO, OO, PO; blends of VCO and OO; VCO and PO were scanned, interpreted, and identified. Two multivariate calibration methods, partial least square (PLS) and principal component regression (PCR), were used to construct the calibration models that correlate between actual and FTIR-predicted values of VCO contents in the mixtures at the FTIR spectral frequencies of 1,120–1,105 and 965–960 cm−1. The calibration models obtained were cross validated using the “leave one out” method. PLS at these frequencies showed the best calibration model, in terms of the highest coefficient of determination (R 2) and the lowest of root mean standard error of calibration (RMSEC) with R 2 = 0.9992 and RMSEC = 0.756, respectively, for VCO in mixture with OO. Meanwhile, the R 2 and RMSEC values obtained for VCO in mixture with PO were 0.9996 and 0.494, respectively. In general, FTIR spectroscopy serves as a suitable technique for determination of VCO in mixture with the other oils
Detection of roe deer, red deer, and hare meat in raw materials and processed products available in Poland
The Application of FT-MIR Spectroscopy for the Evaluation of Energy Value, Fat Content, and Fatty Acid Composition in Selected Organic Oat Products
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Amplitude analysis of ψ3686→γKS0KS0
Using (2712 ± 14) × 106ψ(3686) events collected with the BESIII detector, we perform the first amplitude analysis of the radiative decay ψ3686→γKS0KS0 within the mass region MKS0KS0<2.8 {M}_{K_S^0{K}_S^0}<2.8 GeV/c2. Employing a one-channel K-matrix approach for the description of the dynamics of the KS0KS0 system, the data sample is well described with four poles for the f0-wave and three poles for the f2-wave. The determined pole positions are consistent with those of well-established resonance states. The observed f0 and f2 states are found to be in agreement with those produced in radiative J/ψ decays. The production behaviors of f0 and f2 poles in ψ3686→γKS0KS0 are qualified with their residues and the converted branching fractions. By comparing with J/ψ→γKS0KS0 decay, the ratios Bψ3686→γf0,2BJ/ψ→γf0,2 are determined, which provides crucial experimental inputs on the internal structure of the f0,2 states, especially their potential mixing with glueball components
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