scholarly journals 3D Microfluidic Devices in a Single Piece of Paper for the Simultaneous Determination of Nitrite and Thiocyanate

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4118
Author(s):  
Peng Yu ◽  
Muhan Deng ◽  
Yi Yang ◽  
Beixi Nie ◽  
Shaoyu Zhao
Keyword(s):  
Artificial Saliva ◽  
Colorimetric Detection ◽  
Three Dimensional ◽  
Environmental Tobacco Smoke Exposure ◽  
Tobacco Smoke Exposure ◽  
Well Control ◽  
Single Piece ◽  
Good Repeatability ◽  
First Time

The concentrations of nitrite and thiocyanate in saliva can be used as the biomarkers of the progression of periodontitis disease and environmental tobacco smoke exposure, respectively. Therefore, it is particularly necessary to detect these two indicators in saliva. Herein, the three-dimensional single-layered paper-based microfluidic analytical devices (3D sl-μPADs) were, for the first time, fabricated by the spraying technique for the colorimetric detection of nitrite and thiocyanate at the same time. The conditions for 3D sl-μPADs fabrication were optimized in order to well control the penetration depth of the lacquer in a paper substrate. Then, the developed 3D sl-μPADs were utilized to simultaneously detect nitrite and thiocyanate and the limits of detection are 0.0096 and 0.074 mM, respectively. What is more, the μPADs exhibited good specificity, good repeatability, and acceptable recoveries in artificial saliva. Therefore, the developed 3D sl-μPADs show a great potential to determine nitrite and thiocyanate for the assessment of the human health.

scholarly journals EARTHQUAKES MAGNITUDE AS THE INDICATOR OF THE TECTONOSPHERE PHYSICOMECHANICAL PARAMETERS (to the 80 Anniversary of the Prominent Georgian Seismologist and Geophysicist Leah Ivanovna Tuliani)

2017 ◽  
Author(s):  
Л.Э. Левин
Keyword(s):  
Seismic Waves ◽  
Quantitative Characteristic ◽  
Three Dimensional ◽  
Tien Shan ◽  
Japanese Island ◽  
Empirical Determination ◽  
Original Procedure ◽  
Lithosphere Thickness ◽  
First Time

В статье приведены в сжатом виде результаты исследований, касающиеся строения литосферы Кавказского региона. Приведена оригинальная методика определения мощности литосферы по распределению энергии сейсмических волн с глубиной. Описана впервые выявленная особенность строения орогенов Большого и Малого Кавказа, где мощность литосферы оказалась меньше мощности коры. Приведено определение пространственного распространения т.н. астенолинз – зон частичного плавления в коре орогенов Большого и Малого Кавказа, являющихся очагами орогенного вулканизма. Подобные астенолинзы были также выявлены в коре орогенов Японской островной дуги и Тянь-Шаня и, таким образом, была установлена глобальная особенность строения многих постколлизионных орогенов. Приведены основные положения по эмпирическому определению квадратичной зависимости энергии сейсмических волн от магнитуды и количественной характеристики термодинамических параметров очага землетрясения и др. Results of studies, which are concerned the Caucasian region lithosphere structure are given in the compressed form. The original procedure of the lithosphere thickness determination from the energy distribution of seismic waves with the depth is given. The first time revealed special feature of the large and small Caucasus orogens structure is described, where the lithosphere thickness proved to be less than the thickness of crust. The three-dimensional propagation determination of the so-called astenolenses – zones of partial melting in the crust of the large and small Caucasus orogens, which are the centers of orogenic volcanism is given. Similar astenolenses were also revealed in the orogens crust of Japanese island arc and Tien Shan and was, thus, established the global special feature of the structure of many postkollision orogens. Basic provision of the quadratic dependence of seismic waves energy on the magnitude empirical determination and the quantitative characteristic of the thermodynamic parameters of the seismic center and others are given.

Three-dimensional hydrogen distribution and quantitative determination of titanium alloys via neutron tomography

The Analyst ◽  
2020 ◽  
Vol 145 (12) ◽  
pp. 4156-4163
Author(s):  
Lixia Yang ◽  
Linfeng He ◽  
Danqi Huang ◽  
Yaoqi Wang ◽  
Quanwei Song ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Titanium Alloys ◽  
Three Dimensional ◽  
Neutron Tomography ◽  
Distribution Analysis ◽  
Hydrogen Distribution ◽  
Thermohydrogen Processing ◽  
First Time

For the first time, neutron tomography was applied for 3D quantitative hydrogen distribution analysis in titanium alloys following thermohydrogen processing.

scholarly journals Fusing Multiscale Charts into 3D ENC Systems Based on Underwater Topography and Remote Sensing Image

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Tao Liu ◽  
De-Peng Zhao ◽  
Ming-Yang Pan ◽  
Kun Bai
Keyword(s):  
Remote Sensing ◽  
Three Dimensional ◽  
Remote Sensing Image ◽  
Processing Method ◽  
Display Condition ◽  
Underwater Topography ◽  
Electronic Chart ◽  
Visualization Technology ◽  
First Time

The purpose of this study is to propose an approach to fuse multiscale charts into three-dimensional (3D) electronic navigational chart (ENC) systems based on underwater topography and remote sensing image. This is the first time that the fusion of multiscale standard ENCs in the 3D ENC system has been studied. First, a view-dependent visualization technology is presented for the determination of the display condition of a chart. Second, a map sheet processing method is described for dealing with the map sheet splice problem. A process order called “3D order” is designed to adapt to the characteristics of the chart. A map sheet clipping process is described to deal with the overlap between the adjacent map sheets. And our strategy for map sheet splice is proposed. Third, the rendering method for ENC objects in the 3D ENC system is introduced. Fourth, our picking-up method for ENC objects is proposed. Finally, we implement the above methods in our system: automotive intelligent chart (AIC) 3D electronic chart display and information systems (ECDIS). And our method can handle the fusion problem well.

Analytical Determination of Bioactive Compounds as an Indication of Fruit Quality

2012 ◽  
Vol 95 (6) ◽  
pp. 1725-1732 ◽  
Author(s):  
Yong Seo Park ◽  
Buk-Gu Heo ◽  
Kyung-Sik Ham ◽  
Seong-Gook Kang ◽  
Yang-Kyun Park ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Bioactive Compounds ◽  
Antioxidant Activities ◽  
Three Dimensional ◽  
Analytical Determination ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Antioxidant Capacity Assays ◽  
First Time

Abstract The aim of this investigation was to determine the bioactive compounds in kiwifruit as an indication of quality after extraction using methanol and ethyl acetate. Using FTIR and three-dimensional fluorescence spectroscopy and electrospray ionization/MS, the contents of polyphenols, flavonoids, flavanols, and tannins, and the level of the antioxidant activity by 2, 2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt, 1, 1-diphenyl-2-picrylhydrazyl, ferric-reducing/antioxidant power, and cupric reducing antioxidant capacity assays were determined and compared. It was found that the methanol extracts of kiwifruit showed significantly higher amounts of bioactive compounds and antioxidant activities than the ethyl acetate extracts. The cultivar Bidan, in comparison with the classic Hayward, showed significantly higher bioactivity. For the first time, Bidan organic kiwifruit was analyzed for its antioxidant activities and compared with the widely consumed Hayward organic based on its bioactive compounds and fluorescence properties. Relatively high content of bioactive compounds and positive antioxidant and antiproliferative properties of kiwifruit determined by the advanced analytical methods justify its use as a source of valuable antioxidants. The methods used are applicable for bioactivity determination, in general, for any food products.

scholarly journals N<sub>2</sub>O isotope approaches for source partitioning of N<sub>2</sub>O production and estimation of N<sub>2</sub>O reduction – validation with <sup>15</sup>N gas-flux method in laboratory and field studies

2020 ◽  
Author(s):  
Dominika Lewicka-Szczebak ◽  
Maciej Piotr Lewicki ◽  
Reinhard Well
Keyword(s):  
Three Dimensional ◽  
Field Studies ◽  
Residual Fraction ◽  
N2o Reduction ◽  
Flux Method ◽  
Gas Flux ◽  
Dual Isotope ◽  
Isotopic Signatures ◽  
First Time

Abstract. The approaches based on natural abundance N2O stable isotopes are often applied for the estimation of mixing proportions between various N2O producing pathways as well as for estimation of the extent of N2O reduction to N2. But such applications are associated with numerous uncertainties and hence their limited accuracy needs to be considered. Here we present the first systematic validation of these methods for laboratory and field studies applying the 15N gas-flux method as the reference approach. Besides applying dual isotope plots for interpretation of N2O isotopic data, for the first time we propose a three dimensional N2O isotopocule model based on Bayesian statistics to estimate the N2O mixing proportions and reduction extent based simultaneously on three N2O isotopic signatures (δ15N, δ15NSP and δ18O). Determination of mixing proportions of individual pathways with N2O isotopic approaches appears often imprecise, mainly due to imperfect isotopic separation of the particular pathways. Nevertheless, the estimation of N2O reduction is much more robust, when applying optimal calculation strategy, reaching typically accuracy of N2O residual fraction determination of about 0.1.

scholarly journals N<sub>2</sub>O isotope approaches for source partitioning of N<sub>2</sub>O production and estimation of N<sub>2</sub>O reduction – validation with the <sup>15</sup>N gas-flux method in laboratory and field studies

2020 ◽  
Vol 17 (22) ◽  
pp. 5513-5537
Author(s):  
Dominika Lewicka-Szczebak ◽  
Maciej Piotr Lewicki ◽  
Reinhard Well
Keyword(s):  
Three Dimensional ◽  
Field Studies ◽  
Residual Fraction ◽  
N2o Reduction ◽  
Flux Method ◽  
Gas Flux ◽  
Dual Isotope ◽  
Isotopic Signatures ◽  
First Time

Abstract. The approaches based on natural abundance N2O stable isotopes are often applied for the estimation of mixing proportions between various N2O-producing pathways as well as for estimation of the extent of N2O reduction to N2. But such applications are associated with numerous uncertainties; hence, their limited accuracy needs to be considered. Here we present the first systematic validation of these methods for laboratory and field studies by applying the 15N gas-flux method as the reference approach. Besides applying dual-isotope plots for interpretation of N2O isotopic data, for the first time we propose a three dimensional N2O isotopocule model based on Bayesian statistics to estimate the N2O mixing proportions and reduction extent based simultaneously on three N2O isotopic signatures (δ15N, δ15NSP, and δ18O). Determination of the mixing proportions of individual pathways with N2O isotopic approaches often appears imprecise, mainly due to imperfect isotopic separation of the particular pathways. Nevertheless, the estimation of N2O reduction is much more robust, when applying an optimal calculation strategy, typically reaching an accuracy of N2O residual fraction determination of about 0.15.

scholarly journals A New Method for Simultaneous Determination of Phenolic Acids, Alkaloids and Limonoids in Phellodendri Amurensis Cortex

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 709 ◽  
Author(s):  
Yao Chen ◽  
Zhao Zhang ◽  
Yang Zhang ◽  
Xiaomei Zhang ◽  
Zhipeng Zhang ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Scientific Basis ◽  
Multivariate Statistical ◽  
Chromatographic Fingerprints ◽  
Multi Wavelength ◽  
Good Repeatability ◽  
First Time ◽  
Maximum Absorption Wavelength

Phellodendri Amurensis Cortex (PAC) is a well-known herbal medicine in China with complex components, but the previous research has mostly focused on its alkaloids analysis. For the first time, a simpler and more efficient method was proposed in this paper to simultaneously determine the content of three different kinds of compounds—phenolic acids, alkaloids and limonoids—in PAC. The phenolic acids included 3-O-feruloylquinic acid, 4-O-feruloylquinic acid and syringin. The alkaloids include magnoflorine, phellodendrine, jatrorrhizine, palmatine and berberine, while the limonoids include obaculactone and obacunone. An approach combining multi-wavelength and HPLC-DAD was used in this study due to the great difference in maximum absorption wavelength of the various components. Four wavelengths at 215, 275, 280 and 310 nm, respectively, were chosen for monitoring. It has been indicated through appropriate tests that this approach is of high accuracy, good repeatability and stability and provides a scientific basis for the quality assessment of PAC and associated derivatives. In addition, the chromatographic fingerprints method combined with multivariate statistical analysis chosen in this study was proved to be effective and reasonable for an accurate classification of 33 batches of samples collected from different locations.

Optimization and Validation of HS-SPME-GC-MS for the Determination of Furan and Alkylfurans in Chocolate-Based Products: Impact of Tempering and Laser Printing

2020 ◽  
Author(s):  
Zouheir Alsafra ◽  
Georges Scholl ◽  
Gauthier Eppe
Keyword(s):  
Dilution Technique ◽  
Intermediate Precision ◽  
Internal Standards ◽  
End Products ◽  
Process Contaminants ◽  
Good Repeatability ◽  
Measurement Uncertainties ◽  
Quantitative Impact ◽  
First Time

Abstract Background Furan and its alkyl substituted (2-methylfuran, 3-methylfuran, 2,3-dimethylfuran, 2,5-dimethylfuran) are found in a range between ppm to sub-ppb levels in many foodstuffs undergoing heat treatments like coffee, chicory, or even chocolate. Objectives Two major objectives are presented. First, we aim at optimizing and validating a HS-SPME-GC-MS method for the quantification of five alkylfurans in chocolate. Second, we focus our study on measuring the quantitative impact of engraving technique on the formation of furan and its derivatives in chocolate, from the raw callets to processed end-products. Method HS-SPME-GC-MS method operating in SIM mode and using isotope dilution technique with deuterated homologue internal standards was used to quantify alkylfurans in chocolate. Results Good repeatability (RSD% = 0.1–8%, in duplicate) and intermediate precision (RSD% = 1.7–7%, n = 6) were obtained for these five process contaminants at 10, 25, and 50 µg/kg. Trueness was varying between 81 and 109%. LoQ ranged from 0.48 to 2.50 µg/kg. Relative expanded measurement uncertainties ranged from 6 to 30%. Finally, tempering is responsible for a 24% increase in furan contamination, while the laser engraving technique results in an additional 31% increase in furan. A similar trend was also observed for 2-methylfuran and 3-methylfuran, whereas no significant increases were observed for 2,3-dimethylfuran and 2,5-dimethylfuran. Conclusions and highlights A reliable and sensitive method of HS-SPME-GC-MS was reported for the first time for the analysis of furan and four alkylfurans in chocolate. This paper demonstrated that engraving using laser-based techniques can increase the levels of these compounds by up to 30%.

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