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Emmanuelle Bichon, Ingrid Guiffard, Anaïs Vénisseau, Elodie Lesquin, Vincent Vaccher, Philippe Marchand, Bruno Le Bizec
Brominated Flame Retardants (BFRs) are still widely used for industrial purposes. These contaminants may enter the food chain where they mainly occur in food of animal origin. The aim of our work was to provide a unique method able to quantify the widest range of BFRs in feed and food items. After freeze-drying and grinding, a pressurized liquid extraction was carried out. The extract was purified on acidified silica, Florisil® and carbon columns, the four separated fractions were analyzed by gas and liquid chromatography coupled to high resolution and tandem mass spectrometry...
April 13, 2018: Chemosphere
Rongrong Jing, Huimin Wang, Shaoqing Ju, Ming Cui
BACKGROUND: Molecular diagnoses have become more widespread in many areas of laboratory medicine where qualitative or quantitative approaches are used to detect nucleic acids. The increasing number of assay methods and the targets for molecular diagnostics contribute to variability in the test results among clinical laboratories. Thus, reference materials (RMs) are required to enhance the comparability of results. METHODS: This review focuses on the definition of RMs as well as the production and characteristics of higher order RMs from different organizations and their future strategies...
April 18, 2018: Clinical Biochemistry
Wei Zhao, Don Vernekohl, Fei Han, Bin Han, Hao Peng, Yong Yang, Lei Xing, James K Min
PURPOSE: Many clinical applications depend critically on the accurate differentiation and classi-fication of different types of materials in patient anatomy. This work introduces a unified framework for accurate nonlinear material decomposition and applies it, for the first time, in the concept of triple-energy CT (TECT) for enhanced material differentiation and classification as well as dual-energy CT METHODS: We express polychromatic projection into a linear combination of line integrals of material-selective images...
April 21, 2018: Medical Physics
Ewelina Chajduk, Marta Pyszynska, Halina Polkowska-Motrenko
The aim of this study was to assess the levels of 13 essential and toxic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, Zn) in the infant formulas, available on Polish market. Selected food samples were of animal (cow- and goat-based milks) and plant (soy-based milk, hypoallergic products, grain porridges) origin. Two analytical techniques, inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA), have been complementarily applied to analyze elemental content of 16 formulas dedicated for infants between 0 and 8 months...
April 21, 2018: Biological Trace Element Research
Yujie Zhang, Qiaoqi Li, Benlin Dai, Shouyong Zhou, Mingliang Zhang, Haifeng Han, Hongdeng Qiu
A new polar-embedded aromatic stationary phase has been prepared by covalently attaching p-biphenylacetamide silane to silica spheres. The retention behavior of this phase was compared with an alkylamide counterpart and octadecyl phases using different classes of analytes, including geometric isomers and congeners from Standard Reference Materials 869b, 870 and 1647e, positional isomers of electron-deficient benzenes, as well as alkylbenzenes and alkylbiphenyls. The relationship between shape selectivity and surface chemistry of stationary phase was comparatively studied...
April 14, 2018: Journal of Chromatography. A
Akshay A Murthy, Teodor K Stanev, Jeffrey D Cain, Shiqiang Hao, Trevor LaMountain, Sung Kyu Kim, Nathaniel A Speiser, Kenji Watanabe, Takashi Taniguchi, Chris Wolverton, Nathaniel P Stern, Vinayak P Dravid
Understanding the electronic transport of monolayer transition metal dichalcogenides (TMDs) and their heterostructures is complicated by the difficulty in achieving electrical contacts that do not perturb the material. Typically, metal deposition on monolayer TMDs leads to hybridization between the TMD and the metal, which produces Schottky barriers at the metal semiconductor interface. In this work, we apply the recently reported hexagonal boron nitride (h-BN) tunnel contact scheme to probe the junction characteristics of a lateral TMD heterostructure grown via chemical vapor deposition...
April 20, 2018: Nano Letters
Geon Hyeong Lee, Young Sik Kim
Novel thermally activated delayed fluorescence (TADF) materials including 10H-phenoxaborin (PXB) as an electron acceptor and carbazole derivatives [carbazole (Cz), 1-methyl-carbazole (1-m-Cz), and 3,6-bis(3,6-diphenylcarbazolyl)carbazole (BDPCC)] as electron donors (Cz-PXB, 1-m-Cz-PXB, and BDPCC-PXB) were designed and investigated theoretically for deep blue organic light-emitting diode (OLED). Using density functional theory (DFT) and time-dependent DFT calculations, we obtained the electron distribution of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) and the energy of the lowest singlet (S1) and the lowest triplet (T1) excited states...
September 1, 2018: Journal of Nanoscience and Nanotechnology
Seong-Hwan Kang, Jaeho Choi, Sung-Ho Lee, Young-Hoon Song, Jong-Se Park, In-Sung Jung, Jin-Su Jung, Chong-Yeal Kim, O-Bong Yang
The back sheet is one of the most important materials in photovoltaic (PV) modules. It plays an important role in protecting the solar cell from the environment by preventing moisture penetration. In the back sheet, the outermost layer is composed of a polyester (PET) film to protect the PV module from moisture, and the opposite layer is composed of a TiO2 + PE material. Nowadays, PV modules are installed in the desert. Therefore, methods to improve the power generation efficiency of PV modules need to be investigated as the efficiency is affected by temperature resulting from the heat radiation effect...
September 1, 2018: Journal of Nanoscience and Nanotechnology
Chunyuan Liu, Younghwan Kwon
Porous hydroxyl-terminated polybutadiene-based polyurethane (HPU) composites containing various hollow glass microspheres (HGMs) up to 75 vol.% were synthesized by one-step bulk polyaddition-type polymerization. An unfilled (non-porous) HPU sample was also prepared as a reference. The thermal conductivity of the HPU/HGM composites, which are considered as a three-phasic material composed of a bulk HPU matrix, silicate thin layer, and pores, could be predicted perfectly by the Felske model. The thermal properties, such as Tg and thermal stability, of the HPU/HGM composites were affected slightly by the addition of HGMs compared to the unfilled HPU...
September 1, 2018: Journal of Nanoscience and Nanotechnology
Biancamaria Ciasca, Michelangelo Pascale, Valerio Guido Altieri, Francesco Longobardi, Michele Suman, Dante Catellani, Veronica M T Lattanzio
A strong trend toward using highly selective mass spectrometry technologies for screening of multiple mycotoxins has been observed in recent years. In the present study, the process of validation of a multi-mycotoxin screening method based on liquid chromatography high-resolution mass spectrometry method is presented. The method was intended for the simultaneous screening of the major Fusarium toxins (deoxynivalenol, 3- and 15-acetyl deoxynivalenol, T-2 and HT-2 toxins, zearalenone, enniatins A, A1, B, B1, beauvericin) in wheat...
April 20, 2018: Journal of Mass Spectrometry: JMS
Lei Cao, Jintang Guo, Jianhua Tian, Yang Xu, Miaomiao Hu, Chun Guo, Meiyu Wang, Jinjie Fan
Synthetic polymer fluid loss additive (FLA), an important type of admixture, was broadly applied in modern well cementation. However, the filter loss volume and fluidity of cement pastes containing polymer-FLA would deteriorate remarkably when sea water was used in mixing slurries instead of fresh water. In this study, a novel sustained-release-type fluid loss additive(S-FLA) was synthesized by means of anion-exchange intercalation reaction between an anionic type-copolymer and a calcium/aluminum type-Layered Double Hydroxide (Ca/Al-LDH)...
April 4, 2018: Journal of Colloid and Interface Science
Do Hyeon Yoo, Jaekook Lee, Chul Hee Min
The aim of this study is to develop the Effective Dose Calculation Program (EDCP) for the usage of Naturally Occurring Radioactive Material (NORM) added consumer products. The EDCP was developed based on a database of effective dose conversion coefficient and the Matrix Laboratory (MATLAB) program to incorporate a Graphic User Interface (GUI) for ease of use. To validate EDCP, the effective dose calculated with EDCP by manually determining the source region by using the GUI and that by using the reference mathematical algorithm were compared for pillow, waist supporter, eye-patch and sleeping mattress...
April 9, 2018: Applied Radiation and Isotopes
Qin-Qin Wang, Tao Shen, Zhi-Tian Zuo, Heng-Yu Huang, Yuan-Zhong Wang
The accumulation of secondary metabolites of traditional Chinese medicine (TCM) is closely related to its origins. The identification of origins and multi-components quantitative evaluation are of great significance to ensure the quality of medicinal materials. In this study, the identification of Gentiana rigescens from different geographical origins was conducted by data fusion of Fourier transform infrared (FTIR) spectroscopy and high performance liquid chromatography (HPLC) in combination of partial least squares discriminant analysis; meanwhile quantitative analysis of index components was conducted to provide an accurate and comprehensive identification and quality evaluation strategy for selecting the best production areas of G...
March 2018: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Konstantinos Anastasiadis, Elisabeth A Koulaouzidou, Georgios Palaghias, George Eliades
PURPOSE: To evaluate the effects on the surface properties (morphology, roughness, microhardness, composition) and bond strength to composite of four types of base cements (Equia-Fil/EQF, Angelus white MTA/MTA, Biodentin/ BDN and IRM/IRM) when treated with phosphoric acid etching (PAE) or two self-etch adhesives (Select One Prime & Bond and Clearfil S3 Bond). MATERIALS AND METHODS: Disk-shaped specimens were prepared and stored until complete setting. The surfaces before and after treatments were examined by stereomicroscopy, optical profilometry, ATR-FTIR, and LV-SEM/EDX...
April 19, 2018: Journal of Adhesive Dentistry
Félix Musil, Sandip De, Jack Yang, Joshua E Campbell, Graeme M Day, Michele Ceriotti
Molecular crystals play an important role in several fields of science and technology. They frequently crystallize in different polymorphs with substantially different physical properties. To help guide the synthesis of candidate materials, atomic-scale modelling can be used to enumerate the stable polymorphs and to predict their properties, as well as to propose heuristic rules to rationalize the correlations between crystal structure and materials properties. Here we show how a recently-developed machine-learning (ML) framework can be used to achieve inexpensive and accurate predictions of the stability and properties of polymorphs, and a data-driven classification that is less biased and more flexible than typical heuristic rules...
February 7, 2018: Chemical Science
Dorottya Angyal, Efraín Chávez Solís, Benjamín Magaña, Gergely Balázs, Nuno Simoes
A detailed description of a new stygobiont species of the amphipod family Hadziidae, Mayaweckelia troglomorpha Angyal, sp. n. is given, based on material collected in four cenotes of Yucatán federal state, México. Morphology was studied under light microscopy and with scanning electron microscopy. Morphological description is complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes, with affinities to the related taxa and with notes on the species' ecology. Using COI Bayesian inference and genetic distance analyses, we show that the closest relative of the new species is M...
2018: ZooKeys
Serguei Koulikov, Sergey Assonov, Ales Fajgelj, Pieter Tans
The manuscript explores some advantages and limitations of laser based optical spectroscopy, aimed at achieving robust, high-reproducibility 13 C16 O2 and 12 C16 O2 ratio determinations on the VPDB-CO2 δ13 C scale by measuring the absorbance of line pairs of 13 C16 O2 and 12 C16 O2 . In particular, the sensitivities of spectroscopic lines to both pressure (P) and temperature (T) are discussed. Based on the considerations and estimations presented, a level of reproducibility of the 13 C16 O2 /12 C16 O2 ratio determinations may be achieved of about 10-6 ...
July 1, 2018: Talanta
Kamila Kołacińska, Zbigniew Samczyński, Jakub Dudek, Anna Bojanowska-Czajka, Marek Trojanowicz
This work refers to a comparative study of sorbents widely used in determinations of 99 Tc such as TEVA resin and Dowex 1. Despite having a similar functional group of quaternary amines, both materials represent different chromatographic methods-extraction (TEVA resin) and anion exchange (Dowex 1)-which provides a diverse range of their properties significant in determination of 99 Tc in flow conditions. The comparative tests, carried out in a SIA-LOV (Sequential Injection Analysis-Lab-on-Valve) system combined with mass spectrometric (ICP-MS) detection, considered several factors that are crucial from the standpoint of resin´s utility such as sorption capacity, durability, or selectivity, critical in 99 Tc separation from interferences...
July 1, 2018: Talanta
Abdul Haleem Panhwar, Mustafa Tuzen, Baki Hazer, Tasneem Gul Kazi
A simple, rapid and sensitive solid phase microextraction method was used for the speciation of inorganic antimony (Sb) by using a novel synthesized polymeric material in micropipette tip of syringe system. In present methodology, the specie of Sb (III) made hydrophobic complex with diethyl dithiocarbamate (DDTC) at pH 5.5 and subsequently adsorbed on polystyrene oleic acid imidazole polymer (POIP), whereas Sb(V) did not made complex and adsorbed on the polymer, remained in aqueous solutions. The strategy of multivariate was carried out to screen out the different variables and assessed the optimum values of their experimental values for the extraction efficiency of analyte...
July 1, 2018: Talanta
Peter Bateson, Jack E H Fleet, Anthony S Riseley, Elena Janeva, Anastasia S Marcella, Chiara Farinea, Maria Kuptsova, Núria Conde Pueyo, Christopher J Howe, Paolo Bombelli, Brenda M Parker
Photobioelectrochemical systems are an emerging possibility for renewable energy. By exploiting photosynthesis, they transform the energy of light into electricity. This study evaluates a simple, scalable bioelectrochemical system built from recycled plastic bottles, equipped with an anode made from recycled aluminum, and operated with the green alga Chlorella sorokiniana . We tested whether such a system, referred to as a bio-bottle-voltaic (BBV) device, could operate outdoors for a prolonged time period of 35 days...
April 17, 2018: Biology
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