Analytical Chemistry

In order to examine contamination in the Chungnam Coal Mine area, rock, stream sediment and water samples were collected and analyzed for trace elements. In order to compile the drainage-based geochemical maps, catchment basins were calculated using aspects of DEM (data elevation model) and stream-line segments. The constructed DEMs with 3 types of resolution were examined, these need to be properly used for well-shaped and accurate catchment basins. The stream-line segments and sampling points were also considered as a target image for watershed segments and it was found that the stream-line segments as target images were better role at reflecting the catchment area rather than the sampling points. It is important that the geochemical databases were manipulated to present the various phenomena. Factor analysis in R-mode was used to integrate geochemical data, and the input data for factor analysis were the concentrations of 12 trace elements in stream sediment and 3 anion concentrations and pH values in stream water. Using a maximum likelihood scheme, eigenvalues that explained about 90% of total variance were established and 4 factors were selected. Factors 1 and 2 indicated relative enrichment of trace elements, factor 3 was explained by human activities of residents and factor 4 was related to the pH of stream water. The drainage-based geochemical maps with 4 kinds of factor scores were compiled.

This paper reports a fabrication technology which integrates organic opto-electrowetting (OEW) with PEGDA-based microfluidics between stacked ITO glass chips for droplets generation and manipulation. Organic OEW can be realized by using titanium oxide phthalocyanine (TiOPc) as a photoconductive layer. Optical images can be projected on an organic OEW area to induce the local virtual electrodes which reduce the surface energy for actuating droplets. Low-molecular-weight (LMW) PEGDA (poly(ethylene) glycol diacrylate) material is used to form stable and biocompatible microchannels between the stacked ITO glass chips by UV photopolymerization process. PEGDA-based microfluidics provides a simpler way to enhance droplets applications in organic OEW. We demonstrate (1) the droplet formation in PEGDA microstructure, (2) the motion of droplet-in-air and droplet-in-oil operated by TiOPc OEW in this platform. This technology requires only spin-coating and UV exposure and is more cost-effective than previous methods.

The perfluoroacyl derivatives (pentafluoropropionylamides and heptafluorobutrylamides) of the primary and secondary regioisomeric amines, related to the controlled drug substance 3,4methylenedioxymethamphetamine, are prepared and evaluated in GC-MS studies. These derivatives show excellent resolution on nonpolar stationary phases, such as RTX-1 and RTX-5, with elution order differences from those of the underivatized amines. The mass spectra for these derivatives are significantly individualized, and the resulting unique fragment ions allow for specific side-chain identification. The individualization is the result of fragmentation of the alkyl carbon-nitrogen bond, yielding hydrocarbon fragments and other unique ions. The heptafluoro butrylamides derivatives offer more fragment ions for molecular individualization among these regioisomeric substances.

Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equal mass have been reported as drugs of abuse in forensic studies in recent years. These compounds are 3,4-methylenedioxy-Nethylamphetamine (MDEA), andmethylenedioxyphenyl)-2-butanamine (MBDB). The mass spectra of the regioisomers (4-methoxy-3-methyl and 4-methoxy-2-methylphenethylamines) are essentially equivalent to the three compounds reported as drugs of abuse. This project focused on the synthesis, mass spectral characterization, and chromatographic analysis of these six regioisomeric methoxy methyl phenethylamines. Additionally, the mass spectral and chromatographic properties of these compounds will be compared to the isobaric 2,3-and 3,4-methylenedioxyphenethyl-amines of the same side chain. The six regioisomeric methoxy-methylphenethylamines were synthesized from commercially available starting materials. Side chain differentiation by mass spectrometry was possible after the formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA) and heptafluorobutrylamides (HFBA). Gas chromatographic separation on Rtx-1 was successful at resolving the perfluoroacyl derivatives of the 4-methoxy-3methyl phenethylamines from those of the 4-methoxy-2-methyl phenethylamines. The 4-methoxy-3-methyl-phenethylamine derivatives eluted before the 4-methoxy-2-methyl-phenethylamine derivatives as both the PFPA and HFBA derivatives.

The methoxymethcathinones are uniquely regioisomeric with the controlled drug substance 3,4-methylenedioxymethamphetamine (3,4-MDMA) or Ecstacy. The various isomeric forms of the methoxymethcathinones have mass spectra essentially equivalent to 3,4-MDMA. They all have a molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z 58 and 135/136. Differentiation by mass spectrometry was only possible after formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA), and heptafluorobutrylamides (HFBA). Gas chromatographic separation on nonpolar stationary phases successfully resolved the three methcathinones from 2,3-and 3,4-MDMA as the PFPA and HFBA derivatives. GC-MS analysis was performed with an HP-5890 GC coupled with a HP-5970 mass selective detector (Hewlett Packard, Palo Alto, CA). The MS was operated in the electron impact (EI) mode using an ionization voltage of 70 eV and a source temperature of 230°C. Samples were dissolved in high-performance liquid chromatography-grade acetonitrile (Fisher Scientific, Fair Lawn, NJ) and manually introduced (1 µL), individually and in a physical

The brominated products from all six positional isomers of dimethoxyphenethylamine are prepared, and their analytical properties are evaluated. The major bromination product from 3,5-dimethoxyphenethylamine is the 2,6-dibromo isomer; all other regioisomers of dimethoxyphenethylamine yield a monobromo species as the major product. The mass spectra divide these compounds into two distinct groups: one group showing a strong m/z 180 ion via loss of bromine from the molecular ion (M-Br) + and a second group showing no significant m/z 180 ion. The three compounds that do not show the m/z 180 ion in their electronimpact mass spectra are brominated 2,4-; 2,5-; and 2,6dimethoxyphenethylamine. These compounds are well-resolved by reversed-phase liquid chromatographic methods using a Hypersil Elite C 18 stationary phase and a mobile phase of phosphate buffer (pH 3) and methanol-acetonitrile.

Myristicin, a natural product found in nutmeg oil and nutmeg extract, contains the carbon skeleton for a series of drugs of abuse related to the 3,4-methylenedioxyamphetamines (MDAs). Myristicin, 1-(3-methoxy-4,5-methylenedioxyphenyl)-2-propene, was identified as the major component of commercially available nutmeg oil and in the organic extract of nutmeg powder. The starting materials, intermediates, and products in the synthesis of the drug of abuse N-methyl-1-(3-methoxy-4,5-methylenedioxyphenyl)-2-propanamine (MMDMA) from myristicin were characterized by gas chromatographic-mass spectrometric analysis. MMDMA and several primary amine derivatives including 1-(3-methoxy-4,5-methylenedioxyphenyl)-2-ethanamine, -propanamine, and -butanamine were also prepared from the commercially available aldehyde, 3-methoxy-4,5-methylenedioxybenzaldehyde. Each of these amine derivatives has a distinct mass spectrum characterized by amine-dominated fragmentation. All four amines in this study were resolved by reversed-phase liquid chromatography using an acidic aqueous mobile phase. Relative retention in this system was determined by differences in the hydrophobic surface area of the four amines.

A series of ring and side-chain regioisomers of 3,4-methylenedioxymethamphetamine are compared by chromatographic and spectroscopic methods. Regioisomerism at the aromatic ring and the alkyl side-chain in the methylenedioxyphenalkylamines produces a variety of compounds that have very similar analytical properties. The specific identification of one of these compounds in a forensic drug sample depends on the analyst's ability to eliminate other regioisomers as possible interfering substances. The 2,3-and 3,4-regioisomers of methylenedioxymethamphetamine, N-ethyl-methylenedioxyamphetamine, 1 -methylenedioxyphenyl-2-butanamine, and N-methyM-methylenedíoxyphenyl-2-butanamine are synthesized from commercially available precursor chemicals. The mass spectra for the underivatized amines are very similar and do not provide sufficient information to differentiate among the side-chain or ring regioisomers. Preparation of the pentafluoropropionamides of the amines produces derivatives that show mass spectral fragmentation identifying the substituent attached to nitrogen and the number of carbons attached directly to the aromatic ring. The regioisomeric amines are well-resolved in a reversed-phase chromatographic system using a Hypersil-Elite C18 stationary phase and acidic hydroorganic mobile phases.

Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equivalent mass have been reported as components of clandestine drug samples in recent years. These drugs of abuse are 3,4methylenedioxy-N-ethylamphetamine, 3,4-methylenedioxy-N, N-dimethylamphetamine, and N-methyl-1-(3,4methylenedioxyphenyl)-2-butanamine. These three compounds are a subset of a total of ten regioisomeric 3,4methylenedioxyphenethylamines of molecular weight 207, yielding regioisomeric fragment ions of equivalent mass (m/z 72 and 135/136) in the electron impact mass spectrum. The specific identification of one of these compounds in a forensic drug sample depends upon the analyst's ability to eliminate the other regioisomers as possible interfering or coeluting substances. This paper reports the synthesis, mass spectral characterization, and chromatographic analysis of these ten unique regioisomers. The ten regioisomeric methylenedioxyphenethylamines are synthesized from commercially available precursor chemicals. The electron impact mass spectra of these regioisomers show some variation in the relative intensity of the major ions with only one or two minor ions that might be considered side-chain specific fragments. Thus, the ultimate identification of any one of these amines with the elimination of the other nine regioisomeric substances depends heavily upon chromatographic methods. Chromatographic separation of these ten uniquely regioisomeric amines is studied using gas chromatographic temperature program optimization.

The expanding use of emerging synthetic drugs is creating a growing problem for both seized drug analysts and toxicologists because the clandestine suppliers continually tweak the chemical structures to keep one step ahead of the law. Synthetic cathinones, commonly referred to as bath salts, are a specific class of emerging synthetic drugs. These substances are derivatives of cathinone, which is the psychoactive component of the Catha edulis plant, commonly referred to as khat. Of the synthetic cathinone class of compounds, the a-pyrrolidinophenone synthetic cathinone derivatives stand out as one of the most abused designer drugs. The fragmentation behavior of a series of a-pyrrolidinophenone synthetic cathinones was studied with three different ionization and fragmentation techniques to enhance the current understanding of apyrrolidinophenone synthetic cathinones in mass spectrometers. Gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) fragmentation is commonly used by seized drug analysts, whereas liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) is more commonly used in toxicological analyses. Direct analysis in real time mass spectrometry (DART-MS) is becoming more popular as a screening technique, especially in national laboratories. Each ionization and activation method encourage particular pathways of fragmentation, and whereas some pathways are conserved across all platforms, other pathways are unique to a particular instrument. This study combines isotope-labeling, multi-stage mass spectrometry (MS n ) and accurate mass measurements with high-resolution mass spectrometry (HRMS) to enhance the current understanding about a-pyrrolidinophenone synthetic cathinones. This manuscript provides characteristic protonated tandem mass spectrometry fragmentation pathways and the mechanistic origins of the EI-MS fragmentation observed for this class of synthetic cathinones and provides examples of how this knowledge can be applied to the identification of novel synthetic cathinones.

A direct measurement of the pH of water in contact with supercritical COz was made by observing the spectra of a pH indicator with a W-vis spectrophotometer. The pH was analyzed under pressures of 70-200 atm and temperatures of 25-70 "C. The measured pH varied from 2.80 to 2.95, and relative standard deviations of ~1 . 5 % were achieved. The effects of pH on the efficiency of supercritical fluid extraction of metals and ionizable organic species in water-containing systems are discussed. Supercritical fluid extraction (SFE) has become an attractive alternative to conventional solvent extraction for the recovery of organic compounds and metal chelates from solid and aqueous samples.'sZ Carbon dioxide is the gas of choice for SFE because of its moderate critical constants, inertness, low cost, and availability in pure form. In many environmental applications, water is often present in an SFE system, either as a part of the original sample or added deliberately. The presence of water has been shown to facilitate the extraction of metal ions from solid materials using the in situ chelation technique in supercritical COz.2,3 The role of water in the SFE of organics and metals is not well understood. Water in contact with carbon dioxide becomes acidic due to the formation and dissociation of carbonic acid: Determining the pH of water in contact with supercritical COz is essential to understanding SFE of both metal ions and ionizable organic species. For SFE of metal ions, complexing agents are used to neutralize the metal charge and to transport the metals into the COS phase. The degree of dissociation of the complexing agents is dependent on the pH of the solution. If the complexing agents are not ionized at the solution pH, complexation and

The retention behaviour of positional isomers (phenols, aniline derivatives, quinoline bases) on mixed silicamagnesia adsorbent has been compared with the retention behaviour of the solutes on alumina and on silica. The results are presented as RMAlumina VS. R M mix and RM Silica vs. R a4 mi.~ relationships. The analysis of the structural effects of the solutes and the position on RM 1 vs. RMn diagrams allows the comparison of the active centers on the surface of the investigated adsorbents. The influence of the polar modifier on the retention of model compounds is also discussed. The selectivity of silica-magnesia and silica-magnesium carbonate mixed adsorbents and also Florisil, silica and alumina in three eluent systems (ethyl acetate, 2propanol and dioxane in n-heptane) is presented as ARM values of pairs of positional isomers.

, phosphorus (P), and potassium (K), are needed for site-specific crop management, where fertilizer nutrient application rates are adjusted spatially based on local requirements. This study reports on validation testing of a previously developed ion-selective electrode (ISE) based soil macronutrient sensing system using 36 soil samples from a single site, the Northern Illinois Agronomy Research Center (NIARC), and previously developed calibration models. Objectives were to (1) validate calibration models with a new array of membranes and electrodes, and ( ) evaluate the ability of the system to estimate variations in soil NO 3 -N, P, and K within a single test site. Soil extract samples were obtained using the Kelowna extractant. Electrode responses were measured with five ISEs for each of NO 3 -N, P, and K and were normalized using the baseline correction and two-point normalization methods developed in our previous work. The array of ISEs fabricated with new membranes and cobalt rod, in conjunction with the previously developed normalization methods and calibration models, accurately estimated NO 3 -N, P, and K in solution without need to recalibrate the ISE system through standard laboratory analysis of soil samples from the new test site. ISE-measured NO 3 -N, P, and K concentrations in Kelowna-based soil extracts were similar to those determined by standard instruments, validating the ability of the system to identify within-field macronutrient differences. The use of a calibration factor to adjust ISE measurements for the difference in extraction efficiency between Kelowna and standard extractants resulted in a slope near unity between soil NO 3 -N, P, and K concentrations determined by ISEs and standard methods. However, a relatively large offset in soil P concentration between calibrated ISEs and standard methods will require further investigation to identify the cause. This study showed that it was possible to transfer existing calibration equations to new membranes and electrodes through application of the baseline correction and two-point normalization methods and an adjustment for differences in extraction efficiency. This finding enhances the applicability of the ISEbased soil macronutrient sensing system and methodology for rapid soil analysis.

The effect of membrane distillation process parameters on ethanol-water separation has been investigated using a comprehensive mathematical model. Three mass transfer solutions are considered in the model, namely: the exact solution of the Stefan-Maxwell equations developed by Krishna and Standart; the approximate solution of the Stefan-Maxwell equations suggested by Krishna and Wesselingh; and the binary Fickian solution. Temperature and concentration variation along the flow and diffusion paths are accounted for in the model. Though the exact and approximate solutions of the Stefan-Maxwell equations are coincident with each other, some differences are noticed between them and the Fickian-based solution. The difference between the three mass transfer-based solutions, as well as the process performance under several process parameters, are discussed.

Soil fertility replenishment is a critical factor that many farmers in the tropical American hillsides have to cope with to increase food crop production. The effect of three planted fallow systems (Calliandra houstoniana-CAL, Indigofera zollingeriana-IND, Tithonia diversifolia-TTH) and a crop rotation (maize/beans-ROT) on soil nitrogen mineralization, organic matter and phosphorus fractions was compared to the usual practice of allowing natural regeneration of native vegetation or natural fallow management (NAT). Studies were conducted on severely degraded Colombian volcanic-ash soils, 28 months after fallow establishment, at two on-farm experimental sites (BM1 and BM2) in the Cauca Department. Tithonia diversifolia had a significantly higher contribution to exchangeable Ca, K and Mg as well as B and Zn; the order of soil nutrient contribution was TTH > CAL > IND > NAT > ROT. On the other hand, lND had significantly higher soil NO 3 --N at both experimental farms as compared to all the other fallow system treatments. For the readily available P fraction, CAL and ROT had significantly higher H 2 O-Po and resin-Pi, respectively, in the 0-5 cm soil layer; whereas TTH showed significantly higher values for both H 2 O-Po and resin-Pi in the 5-10 cm soil layer. Significant effects were observed on the weights of the soil organic matter fractions which decreased in the order LL (Ludox light) >LM (Ludox intermediate) >LH (Ludox heavy). Indigofera zollingeriana showed greater C, N and P in the soil organic matter fractions than all the other fallow treatments, with NAT having the lowest values. It is concluded that planted fallows can restore soil fertility more rapidly than natural fallows.

A core shell chromatographic column was used to separate the nine process related and degradation related impurities(Imp-1 to Imp-9) of Macitentanis described in this article. The chromatographic separation was achieved on a Sigma-Aldrich"s "Ascentis Express ® C18 (4.6 mm x 100 mm, 2.7 µ)" HPLC column with a runtime of 35 min. Forced degradation study was carried out under acidic, alkaline, oxidative, photolytic, and thermal degradation conditionsto demonstrate the stability-indicating nature of developed RP-HPLC method.The methodology consists of mobile phase-A as aphosphate buffer and mobile phase-B as a mixture of acetonitrile andmethanol. The column oven temperature was set at 45°C, injection thermostat was set at 5°C, and photodiode array detector (PDA) was set at 215 nm.Adeveloped method was validated as per ICH guideline and found rapid, specific,precise, sensitive,androbust. The proposed RP-HPLC method was successfully applied to the analysis of drug substance...

Every year, thousands of suspicious deaths are accounted for by an overdose of opioids. Occasionally all traditional matrices are unavailable due to decomposition. Skeletal tissue may pose a valid alternative. However, reference data on postmortem concentrations in bone tissue and bone marrow (BM) is sparse. Therefore, a liquid chromatography--tandem mass spectrometry method was developed and fully validated for the analysis of four opioids and two metabolites (tramadol, O-desmethyltramadol, morphine, fentanyl, norfentanyl, codeine) in bone tissue and BM. Sample preparation was performed using solid phase extraction (BM), methanolic extraction (bone) and a protein precipitation (whole blood). All validation parameters were successfully fulfilled. This method was applied to analyze 22 forensic cases involving opioids. All six opioids were proven to be detectable and quantifiable in all specimens sampled. When tramadol blood concentrations were correlated with bone concentrations, a l...

Various lactic acid bacteria (LAB) have been isolated and screened for biosurfactant production and their biomedical and food applications. Additionally, various different concentrations of the biosurfactant (0.625-25 mg ml -1 ) were used to evaluate its antimicrobial and antiadhesive potential against a range of pathogenic microorganisms. Biosurfactant was found to be stable to pH changes over a range of 4.0-12.0, being most effective at pH 7 and showed no apparent loss of surface tension and emulsification efficiency after heat treatment at 125 °C for 15 min. Present study demonstrated that biosurfactant obtained from Lactobacillus helveticus has the ability to counteract effectively the initial deposition of biofilm forming pathogens to silicone surfaces and to significantly sluggish biofilm growth.

Allyloxy-pyridinium salts with various substituents on the allylic moiety are shown to be very efficient coinitiators in radical promoted cationic polymerization of cyclohexene oxide. Depending upon the radical initiator chosen, cationic polymerizations may be initiated by either heat or light. For the most part, the mechanism of initiation involves the addition of free radicals formed by the radical initiator, and a subsequent fragmentation of the energy-rich intermediate yielding initiating pyridinium type radical cations. In additionÈ fragmentation polymerization, the substituent at the allylic moiety does not sig-niÐcantly inÑuence the polymerization rate, thus implying that fragmentation is the rate determining step. In some cases, oxidation of the primarily formed free radicals contributes to the formation of initiating species. The salts under investigation are also able, to various extents, to initiate cationic polymerization upon external stimulation (heating or UV irradiation) without added radical initiators.

imaging is a powerful technique allowing us to explore non-conducting materials or their arrangements such as envelopes, packaging substances, and clothing materials in a nondestructive way. The direct implementation of THz imaging systems relies, on the one hand, on their convenience of use and compactness, minimized optical alignment, and low power consumption; on the other hand, an important issue remains the system cost and its figure of merit with respect to the image quality and recording parameters. In this paper, we report on the design and performance of an extraordinary low-cost THz imaging system relying on a InP Gunn diode emitter, paraffin wax optics, and commercially available GaAs high-electron-mobility transistors (HEMTs) with a gate length of 200 nm as the sensing elements in a room temperature environment. The design and imaging performance of the system at 94 GHz is presented, and the spatial resolution in the range of the illumination wavelength (∼3 mm) and contrast of nearly two orders of magnitude is determined. The operation of two models of the HEMTs of the same nominal 20 GHz cut-off frequency, but placed in different packages and printed circuit board layouts was evaluated at 94 GHz and 0.307 THz. The presence of two competing contributions-self-resistive mixing and radiation coupling through the antenna effects of the printed circuit boards-to the detected signal is revealed by the signal dependence on the gate-to-source voltage, resulting in a cross-sectional responsivity of 27 V/W and noise-equivalent power of 510 pW/ √ Hz at 94 GHz. Further routes in the development of low-cost THz imaging systems in the range of EUR 100 are considered.

This paper presents and explains an implementation of Learning Vector Quantization neural network for tennis activity detection and recognition using PIQ ROBOT device. The gesture recognition market is estimated to grow from 2013 till 2018 and is expected to cross $15.02 billion by the end of these five years. Analysts forecast the Global Gesture Recognition market to grow of 29.2 percent over the period 2013-2018. In terms of industry it means that currently consumer electronics application contributes to more than 99 percents of the global gesture recognition market. This paper starts our ambitious research in the area of artificial neural networks for activity recognition.

The wealth of smartphone data collected by the Cosmic Ray Extremely Distributed Observatory (CREDO) greatly surpasses the capabilities of manual analysis. So, efficient means of rejecting the non-cosmic-ray noise and identification of signals attributable to extensive air showers are necessary. To address these problems we discuss a Convolutional Neural Network-based method of artefact rejection and complementary method of particle identification based on common statistical classifiers as well as their ensemble extensions. These approaches are based on supervised learning, so we need to provide a representative subset of the CREDO dataset for training and validation. According to this approach over 2300 images were chosen and manually labeled by 5 judges. The images were split into spot, track, worm (collectively named signals) and artefact classes. Then the preprocessing consisting of luminance summation of RGB channels (grayscaling) and background removal by adaptive thresholding was performed. For purposes of artefact rejection the binary CNN-based classifier was proposed which is able to distinguish between artefacts and signals. The classifier was fed with input data in the form of Daubechies wavelet transformed images. In the case of cosmic ray signal classification, the well-known feature-based classifiers were considered. As feature descriptors, we used Zernike moments with additional feature related to total image luminance. For the problem of artefact rejection, we obtained an accuracy of 99%. For the 4-class signal classification, the best performing classifiers achieved a recognition rate of 88%.

In this paper, we describe the convolutional neural network (CNN)-based approach to the problems of categorization and artefact reduction of cosmic ray images obtained from CMOS sensors used in mobile phones. As artefacts, we understand all images that cannot be attributed to particles' passage through sensor but rather result from the deficiencies of the registration procedure. The proposed deep neural network is composed of a pretrained CNN and neural-network-based approximator, which models the uncertainty of image class assignment. The network was trained using a transfer learning approach with a mean squared error loss function. We evaluated our approach on a data set containing 2350 images labelled by five judges. The most accurate results were obtained using the VGG16 CNN architecture; the recognition rate (RR) was 85.79% ± 2.24% with a mean squared error (MSE) of 0.03 ± 0.00. After applying the proposed threshold scheme to eliminate less probable class assignments, we obtained a RR of 96.95% ± 1.38% for a threshold of 0.9, which left about 62.60% ± 2.88% of the overall data. Importantly, the research and results presented in this paper are part of the pioneering field of the application of citizen science in the recognition of cosmic rays and, to the best of our knowledge, this analysis is performed on the largest freely available cosmic ray hit dataset.

Micronutrients are essential to health at every life stage and their deficiencies are associated with increased incidence of various pathophysiological states and poor quality of life. Efficient methods are therefore needed to monitor micronutrient status of individuals and to improve evidenced-based recommendations for populations. This review (i) reports current approaches to assess the vitamin and mineral status in humans, (ii) summarizes current analytical advantages and shortcomings and (iii) provides practical information for both nutrition research and nutritional status diagnostics. Future analytical perspectives are discussed in relation to micronutrient profiling, analytical sensitivity, and miniaturized technologies.

An inkjet-printed relative humidity sensor based on capacitive changes which responds to different humidity levels in the environment is presented in this work. The inkjet-printed silver interdigitated electrodes configuration on the paper substrate allowed for the fabrication of a functional proof-of-concept of the relative humidity sensor, by using the paper itself as a sensing material. The sensor sensitivity in terms of relative humidity changes was calculated to be around 2 pF/RH %. The response time against different temperature steps from 3 to 85 • C was fairly constant (about 4-5 min), and it was considered fast for the aimed application, a smart label.

Fault diagnosis in multistage manufacturing processes (MMPs) is a challenging task where most of the research presented in the literature considers a predefined inspection scheme to identify the sources of variation and make the process diagnosable. In this paper, a sequential inspection procedure to detect the process fault based on a sequential testing algorithm and a minimum monitoring system is proposed. After the monitoring system detects that the process is out of statistical control, the features to be inspected (end of line or in process measurements) are defined sequentially according to the expected information gain of each potential inspection measurement. A case study is analyzed to prove the benefits of this approach with respect to a predefined inspection scheme and a randomized sequential inspection considering both the use and non-use of fault probabilities from historical maintenance data.

Monitoring what application or type of applications running on a computer or a cluster without violating the privacy of the users can be challenging, especially when we may not have operator access to these devices, or specialized software. Smart grids and Internet of things (IoT) devices can provide power consumption data of connected individual devices or groups. This research will attempt to provide insides on what applications are running based on the power consumption of the machines and clusters. It is therefore assumed that there is a correlation between electric power and what software application is running. Additionally, it is believed that it is possible to create power consumption profiles for various software applications and even normal and abnormal behavior (e.g., a virus). In order to achieve this, an experiment was organized for the purpose of collecting 48 h of continuous real power consumption data from two PCs that were part of a university computer lab. That inc...

Realization of navigation in virtual environments remains a challenge as it involves complex operating conditions. Decomposition of such complexity is attainable by fusion of sensors and machine learning techniques. Identifying the right combination of sensory information and the appropriate machine learning technique is a vital ingredient for translating physical actions to virtual movements. The contributions of our work include: (i) Synchronization of actions and movements using suitable multiple sensor units, and (ii) selection of the significant features and an appropriate algorithm to process them. This work proposes an innovative approach that allows users to move in virtual environments by simply moving their legs towards the desired direction. The necessary hardware includes only a smartphone that is strapped to the subjects’ lower leg. Data from the gyroscope, accelerometer and campus sensors of the mobile device are transmitted to a PC where the movement is accurately ide...

Percutaneous vapor dosing studies have generally used saturated vapor concentration (SVC) measurements to estimate the exposure dose (Ct) of vapor produced from a volatile liquid within a closed system. The purpose of this study was to clarify whether the assumption was valid when translated to a biological system (pig skin) using sulfur mustard (SM) as a model skin penetrant. Three systems were evaluated, two containing skin and a control system (without skin). At set time points, samples from the headspace of each dosing system were extracted using a gas-tight syringe and analyzed by gas chromatography in conjunction with a flameionization detector. This demonstrated the rapid achievement of a constant vapor concentration within the biological and control systems and enabled a comparison with previously determined SVCs attained under ideal conditions. All three systems attained a constant vapor concentration within 2 rain of exposure to SM. The control system reached an equilibrium vapor concentration of 1179 + 164 mg/m 3, a value not significantly different from that derived from the SVC (1363 rag/m3). Because of absorption in the skin systems, SM vapor concentrations were significantly lower than that derived from the SVC and were dependent on the skin surface area within the dosing chamber (592 + 246 mg/m 3 for a surface area of 10.15 cm 2 and 740 + 224 mg/m 3 for a surface area of 2.54 cm2). The assumption that SVC gives an acceptable measure of the Ct was shown to be valid by comparison with sulfur mustard recovered from the skin.

Background: Kansui Radix (Gansui in Chinese), the dried tuber of Euphorbia kansui, is a Chinese medicinal herb commonly used for the treatment of oedema and ascites with dyspnea. Because of its toxic nature, the herb is usually processed with vinegar to reduce the toxicity. A report has shown that the contents of toxic terpenoids in Gansui decreased after processing with vinegar. However, comprehensive comparison of the chemical profiles between vinegar-processed and raw Gansui has not yet been conducted. Methods: An ultra-high-performance liquid chromatography in conjunction with ultra-high resolution quadrupole time-of-flight mass spectrometry (UHPLC UHD Q-TOF MS/MS) method was developed for the analysis of chemical profiles of vinegar-processed and raw Gansui in this study. Results: Results showed that processing with vinegar caused conspicuous chemical changes. Among the altered components, 11 toxic terpenoids, 3-O-benzoyl-13-O-dodecanoylingenol/20-O-benzoyl-13-O-dodecanoylingenol, kansuinine D, kansuinine A, 3-O-benzoyl-13-O-dodecanoylingenol/20-O-benzoyl-13-O-dodecanoylingenol, 3-Obenzoylingenol/20-O-benzoylingenol, 20-O-(2′E,4′Z-decadienoyl)ingenol/20-O-(2′E,4′E-decadienoyl)ingenol/3- were tentatively identified. The contents of most of these terpenoids were obviously decreased after processing with reductions of 6.66-95.25 %. Conclusion: Our findings could help us understand the chemical basis for the toxicity reduction of Gansui afforded by processing with vinegar. Further investigations are warranted to establish the relationship between processing-induced chemical changes and the reduction of toxicity of Gansui.

The epoxide hydrolase (EH) family of enzymes is responsible for converting the epoxide residue of various endogenous and exogenous compounds to the corresponding vicinal diols (Morisseau and ammock 2005). Soluble epoxide hydrolase (sEH) is an enzyme in the a-/b-hydrolase fold protein family, primarily found in the cytosolic and peroxisomal fractions of cells (Chiamvimonvat et al. 2007). It is encoded by the EPHX2 gene. It is a bifunctional homodimer that has EH activity at the C-terminal domain and phosphatase activity at the N-terminal domain (He et al. 2016). sEH is abundantly expressed in the liver, but it is also present in most organs including the kidney, brain, smooth muscle, intestines, and lungs (Morisseau and Hammock 2005). Its substrate selectivity is largely restricted to noncyclic 1,2-disubstituted epoxides, and hence, unlike the microsomal epoxide hydrolase (mEH), it is generally not involved in the metabolism or detoxification of xenobiotics (Morisseau and Hammock 200...

This communication reports the formation of complex Langmuir monolayer at the air-water interface with the water-soluble -trimethyl ammonium bromide (CTAB) molecules when interacted with the stearic acid (SA) molecules. The reaction kinetics of the formation of the CTAB-SA complex was monitored by observing the surface pressure versus time graph. Multilayered LB films of this complex doped with congo red was successfully formed onto a quartz substrate. UV-Vis absorption and steady state fluorescence spectroscopic characteristics of this doped LB films confirms the successful incorporation of congo red molecules in to the CTAB-SA complex films.

Isothermal titration calorimetry (ITC) can provide detailed information on the thermodynamics of biomolecular interactions in the form of equilibrium constants, K A , and enthalpy changes, ΔH A . A powerful application of this technique involves analyzing the temperature dependences of ITCderived K A and ΔH A values to gain insight into thermodynamic linkage between binding and additional equilibria, such as protein folding. We recently developed a general method for global analysis of variable temperature ITC data that significantly improves the accuracy of extracted thermodynamic parameters and requires no prior knowledge of the coupled equilibria. Here we report detailed validation of this method using Monte Carlo simulations and an application to study coupled folding and binding in an aminoglycoside acetyltransferase enzyme.

To prevent eutrophication of surface water, phosphate needs to be removed from sewage. Iron (Fe) dosing is commonly used to achieve this goal either as the main strategy or in support of biological removal. Vivianite (Fe(II) 3 (PO 4 ) 2 *8H 2 O) plays a crucial role in capturing the phosphate, and if enough iron is present in the sludge after anaerobic digestion, 70 to 90% of total phosphorus (P) can be bound in vivianite. Based on its paramagnetism and inspired by technologies used in the mining industry, a magnetic separation procedure has been developed. Two digested sludges from sewage treatment plants using Chemical Phosphorus Removal were processed with a lab-scale Jones magnetic separator with an emphasis on the characterization of the recovered vivianite and the P-rich caustic solution. The recovered fractions were analyzed with various analytical techniques (e.g., ICP-OES, TG-DSC-MS, XRD and Mössbauer spectroscopy). The magnetic separation showed a concentration factor for phosphorus and iron of 2-3. The separated fractions consist of 52% to 62% of vivianite, 20% of organic matter, less than 10% of quartz and a small quantity of siderite. More than 80% of the P in the recovered vivianite mixture can be released and thus recovered via an alkaline treatment while the resulting iron oxide has the potential to be reused. Moreover, the trace elements in the P-rich caustic solution meet the future legislation for recovered phosphorus salts and are comparable to the usual content in Phosphate rock. The efficiency of the magnetic separation and the advantages of its implementation in WWTP are also discussed in this paper.

Oxidation of DNA by reactive oxygen species (ROS) yields 8-oxo-7,8-dihydroguanosine (8-oxodG) as primary oxidation product, which can lead to downstream G to T transversion mutations. DNA mutations are nonrandom, and mutations at specific codons are associated with specific cancers, as widely documented for the p53 tumor suppressor gene. Here, we present the first direct LC-MS/MS study (without isotopic labeling or hydrolysis) of primary oxidation sites of p53 exon 7. We oxidized a 32 base pair (bp) double-stranded (ds) oligonucleotide representing exon 7 of the p53 gene. Oxidized oligonucleotides were cut by a restriction endonuclease to provide small strands and enable positions and amounts of 8-oxodG to be determined directly by LC-MS/MS. Oxidation sites on the oligonucleotide generated by two oxidants, catechol/Cu 2+ / NADPH and Fenton's reagent, were located and compared. Guanines in codons 243, 244, 245, and 248 were most frequently oxidized by catechol/Cu 2+ /NADPH with relative oxidation of 5.6, 7.2, 2.6, and 10.7%, respectively. Fenton's reagent oxidations were more specific for guanines in codons 243 (20.3%) and 248 (10.4%). Modeling of docking of oxidizing species on the dsoligonucleotide were consistent with the experimental codon oxidation sites. Significantly, codons 244 and 248 are mutational "hotspots" in nonsmall cell and small cell lung cancers, supporting a possible role of oxidation in p53 mutations leading to lung cancer.

A novel technique for calibration transfer called the Modified Four Point Interpolant (MFPI) method is introduced for near infrared spectra. The method is founded on physical intuition and utilizes a series of quasiconformal maps in the frequency domain to transfer spectra from a slave instrument to a master instrument's approximated space. Comparisons between direct standardization (DS), piecewise direct standardization (PDS), and MFPI for two publicly available datasets are detailed herein. The results suggest that MFPI can outperform DS and PDS with respect to root mean squared errors of transfer and prediction. Combinations of MFPI with DS/PDS are also shown to reduce predictive errors after transfer.

Five simple soft sensor methodologies with two update conditions were compared on two experimentally-obtained datasets and one simulated dataset. The soft sensors investigated were moving window partial least squares regression (and a recursive variant), moving window random forest regression, the mean moving window of y, and a novel random forest partial least squares regression ensemble (RF-PLS), all of which can be used with small sample sizes so that they can be rapidly placed online. It was found that, on two of the datasets studied, small window sizes led to the lowest prediction errors for all of the moving window methods studied. On the majority of datasets studied, the RF-PLS calibration method offered the lowest onestep-ahead prediction errors compared to those of the other methods, and it demonstrated greater predictive stability at larger time delays than moving window PLS alone. It was found that both the random forest and RF-PLS methods most adequately modeled the datasets that did not feature purely monotonic increases in property values, but that both methods performed more poorly than moving window PLS models on one dataset with purely monotonic property values. Other data dependent findings are presented and discussed.

Exploratory data analysis is crucial for developing and understanding classification models from high-dimensional datasets. We explore the utility of a new unsupervised tree ensemble called uncharted forest for visualizing class associations, sample-sample associations, class heterogeneity, and uninformative classes for provenance studies. The uncharted forest algorithm can be used to partition data using random selections of variables and metrics based on statistical spread. After each tree is grown, a tally of the samples that arrive at every terminal node is maintained. Those tallies are stored in single sample association matrix and a likelihood measure for each sample being partitioned with one another can be made. That matrix may be readily viewed as a heat map, and the probabilities can be quantified via new metrics that account for class or cluster membership. We display the advantages and limitations of using this technique by applying it to two classification datasets and ...

The resolution and quantitation of pure spectra of minority components in measurements of chemical mixtures without prior knowledge of the mixture is a challenging problem. In this work, a combination of band target entropy minimization (BTEM) and target partial least squares (T-PLS) was used to obtain estimates for single pure component spectra and to calibrate those estimates in a true, one-at-a-time fashion. This approach allows for minor components to be targeted and their relative amounts estimated in the presence of other varying components in spectral data. The use of T-PLS estimation is an improvement to the BTEM method because it overcomes the need to identify all of the pure components prior to estimation. Estimated amounts from this combination were found to be similar to those obtained from a standard method, multivariate curve resolution-alternating least squares (MCR-ALS), on a simple, three component mixture dataset. Studies from two experimental datasets demonstrate ...

The increasing availability of big Automatic Identification Systems (AIS) sensor data offers great opportunities to track ship activities and mine spatial-temporal patterns of ship traffic worldwide. This research proposes a data integration approach to construct Global Shipping Networks (GSN) from massive historical ship AIS trajectories in a completely bottom-up way. First, a DBSCAN (Density-Based Spatial Clustering of Applications with Noise) algorithm is applied to temporally identify relevant stop locations, such as marine terminals and their associated events. Second, the semantic meanings of these locations are obtained by mapping them to real ports as identified by the World Port Index (WPI). Stop events are leveraged to develop travel sequences of any ship between stop locations at multiple scales. Last, a GSN is constructed by considering stop locations as nodes and journeys between nodes as links. This approach generates different levels of shipping networks from the terminal, port, and country levels. It is illustrated by a case study that extracts country, port, and terminal level Global Container Shipping Networks (GCSN) from AIS trajectories of more than 4000 container ships in 2015. The main features of these GCSNs and the limitations of this work are finally discussed.