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Carsten Jaeschke Marta Padilla Johannes Glckler Inese Polaka Martins Leja Viktors Veliks Jan Mitrovics Marcis Leja Boris Mizaikoff 《Molecules (Basel, Switzerland)》2021,26(12)
Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer system comprises a compact, low volume, temperature-controlled sensing chamber in three modules that can host any type of resistive gas sensor arrays. Furthermore, in this study three modular breath analyzers are explicitly tested for reproducibility in a real-life breath analysis experiment with several calibration transfer (CT) techniques using transfer samples from the experiment. The experiment consists of classifying breath samples from 15 subjects before and after eating a specific meal using three instruments. We investigate the possibility to transfer calibration models across instruments using transfer samples from the experiment under study, since representative samples of human breath at some conditions are difficult to simulate in a laboratory. For example, exhaled breath from subjects suffering from a disease for which the biomarkers are mostly unknown. Results show that many transfer samples of all the classes under study (in our case meal/no meal) are needed, although some CT methods present reasonably good results with only one class. 相似文献
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Quanli Hu Satoru Tanaka Toshiaki Yoneoka Viktors Grismanovs Tetsuji Noda 《辐射效应与固体损伤》2013,168(3):247-253
Abstract The aggregation of F-type defects in AIN has been observed for the first time under He+ ion irradiation by using in-situ luminescence measurement. The concentration of aggregation of F-type defects shows a strong dependence on irradiation temperature (300–773 K) under He+ ion irradiation. The mechanism of growth and annihilation of the aggregation of F-type defects was discussed. 相似文献
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Stephen Hyde Dr. Janis Veliks Dr. Benoît Liégault Dr. David Grassi Dr. Marc Taillefer Prof. Véronique Gouverneur 《Angewandte Chemie (International ed. in English)》2016,55(11):3785-3789
Copper‐catalyzed Si?H, B?H, P?H, S?H, and N?H insertion reactions of 2,2,2‐trifluoro‐1‐diazoethane and 1‐aryl 2,2,2‐trifluorodiazoethanes generated a large number of new fluorine‐containing chemical entities for medicinal chemists. With selected Si?H and B?H insertion reactions, we demonstrate successful extension to asymmetric catalysis. 相似文献
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Zenta Tetere Viktors Kumpiņš Sergey Belyakov Daina Zicāne Māris Turks 《Journal of heterocyclic chemistry》2011,48(3):724-728
For the first time, synthesis and X‐ray analysis of 7‐bromoarbidol hydrochloride is reported. The latter is a proven impurity of Arbidol which is an antiviral drug marketed in Russia and China. J. Heterocyclic Chem., (2011). 相似文献
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Nagarajan Ramkumar Larisa Baumane Dzintars Zacs Janis Veliks 《Angewandte Chemie (International ed. in English)》2023,62(12):e202219027
A simple process for the oxy-monofluoromethylation of alkenes is described. In combination with visible-light copper(I) photoredox catalysis, an easily accessible iodine(III) reagent containing monofluoroacetoxy ligands serves as a powerful source of a monofluoromethyl (CH2F) radical, enabling the step economical synthesis of γ-fluoro-acetates from a broad range of olefinic substrates under mild conditions. Applications to late-stage diversification of alkenes derived from complex molecules, amino acids and the synthesis of fluoromethylated heterocycles are also demonstrated. 相似文献
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Poly(phenylene ether ketones) were prepared by polyacylation reactions in hydrogen fluoride-boron trifluoride and by aluminum trichloride promoted Friedel-Crafts reactions modified by Lewis bases. Structural and engineering properties of these polymers are presented. 相似文献
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Stephen Hyde Janis Veliks David M.H. Ascough Robert Szpera Robert S. Paton Véronique Gouverneur 《Tetrahedron》2019,75(1):17-25
Aryl substituted 2,2,2-trifluorodiazoethanes undergo rhodium(II)-catalysed insertion reactions with tin hydrides affording the corresponding α-(trifluoromethyl)benzyl stannanes. This reactivity contrasts with that of diazo esters which predominantly afford CH2 reduction products in the presence of tin hydrides. The first example of asymmetric insertion into tin hydrides using diazo compounds is also described. In addition, this system extends to asymmetric germanium hydride and silane insertion. 相似文献
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Dr. Janis Veliks Armands Kazia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(15):3786-3789
Diarylfluoromethyl sulfonium salts are efficient fluoromethylene transfer reagents equivalent to fluorocarbene, which is difficult to access. This was demonstrated by the development of a monofluorinated Johnson–Corey–Chaykovsky reaction with ketones and aldehydes, delivering uncommon 2-unsubstituted fluoroepoxides. This is the first evidence for the feasibility of sulfur fluoromethylylide and its action as a reaction intermediate. 相似文献
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