Parallel Measurements Research Articles

Immunoaffinity LC-MS/MS Quantification of the Sepsis Biomarker Procalcitonin Using Magnetic- and Polystyrene-Bead Immobilized Polyclonal Antibodies.

Procalcitonin (PCT) is a biomarker for bacterial sepsis, and accurate quantification of PCT is critical for sepsis diagnosis and treatment. Immunological PCT quantification methods are routinely used in clinical laboratories, yet there is a need for harmonization of PCT quantification protocols. An orthogonal method to clinical immunological assays, such as LC-MS/MS, is required. In this study, a highly sensitive and robust immunoaffinity LC-MRM quantitative method for detecting procalcitonin in human serum has been developed. An initial comparison of immunocapture of PCT with a polyclonal anti-PCT antibody immobilized on polystyrene nanoparticles (Latex) and magnetic beads demonstrated superior performance with magnetic beads. Three tryptic PCT peptides from the N- and C-terminal regions of PCT were selected for LC-MS/MS quantification. For PCT quantification, an LLOQ of 0.25 ng/mL of PCT in human serum was achieved using a sample volume of 1 mL. The method's trueness and precision consistently lie within the 15% margin. The parallel measurement of three PCT peptides may allow future differentiation of intact PCT vs other PCT forms originating from potential degradation, processing, or polymorphisms. An established and validated LC-MRM-based quantification of PCT will be relevant as an orthogonal method for harmonization and standardization of clinical assays for PCT.

NMR chemical shift prediction and structural elucidation of linker-containing oligo- and polysaccharides using the computer program CASPER

Carbohydrate structures containing alkyl groups as aglycones are useful for investigating enzyme activity and glycan-protein interactions. Moreover, linker-containing oligosaccharides with a spacer group are commonly used to print glycan microarrays or to prepare protein-conjugates as vaccine candidates. The structural accuracy of these synthesized glycans are essential for interpretation of results from biological experiments in which the compounds have been used and NMR spectroscopy can unravel and confirm their structures. An approach for efficient 1H and 13C NMR chemical shift assignments employed a parallel NOAH-10 measurement followed by NMR spin-simulation to refine the 1H NMR chemical shifts, as exemplified for a disaccharide with an azidoethyl group as an aglycone, the NMR chemical shifts of which have been used to enhance the quality of CASPER (http://www.casper.organ.su.se/casper/). The CASPER program has been further developed to aid characterization of linker-containing oligo- and polysaccharides, either by chemical shift prediction for comparison to experimental NMR data or as structural investigation of synthesized glycans based on acquired unassigned NMR data. The ability of CASPER to elucidate structures of linker-containing oligosaccharides is demonstrated and comparisons to assigned or unassigned NMR data show the utility of CASPER in supporting a proposed oligosaccharide structure. Prediction of NMR chemical shifts of an oligosaccharide, corresponding to the repeating unit of an O-antigen polysaccharide, having a linker as an aglycone and a non-natural substituent derivative thereof are presented to exemplify the diversity of structures handled. Furthermore, NMR chemical shift predictions of synthesized polysaccharides, corresponding to bacterial polysaccharides, containing a linker are described showing that in addition to oligosaccharide structures also polysaccharide structures having an aglycone spacer group can be analyzed by CASPER.

BAALC-Expressing Leukemia Hematopoietic Stem Cells and Their Place in the Study of CBF-Positive Acute Myeloid Leukemias in Children and Adults

Background. Due to changing views on pathogenesis, risk factors and therapy strategies in prognostically favorable CBF-positive acute myeloid leukemias[1] (AML), the expression monitoring of RUNX1/RUNX1T1 or CBFB/MYH11 fusion genes, as an additional evaluation of treatment outcomes, appears to be insufficient. This indicates the need to improve the monitoring of the CBF+ AML course by means of parallel measurements of BAALC expression levels which roughly correlate with the mass of BAALC-expressing leukemia hematopoietic stem cells (BAALC-e LHSC).
 Aim. To improve the quality of assessing treatment outcomes with due account for expression levels of RUNX1/RUNX1T1 or CBFB/MYH11 fusion genes and the mass of BAALC-e LHSC and on this basis to pave the way for personalized CBF+ AML treatment.
 Materials & Methods. This study enrolled 39 adult patients aged 20–81 years (median 32 years) and 8 children aged 2–18 years (median 12 years). Among them there were 20 females and 27 males. AML with inv(16)(p13;q22)/t(16;16) was identified in 19 patients, t(8;21)(q22;q22) was detected in 28 patients. BAALC, WT1, RUNX1/RUNX1T1, CBFB/MYH11 expression levels were measured by quantitative real-time PCR and related to the expression of the ABL1 expert gene.
 Results. In 23 patients, inv(16) and t(8;21) appeared to be isolated. Additional multidirectional chromosomal changes were observed in 24 patients with inv(16) and in 18 patients with t(8;21). All enrolled patients showed increased BAALC expression. In the course of therapy, it was decreasing to the threshold value in 16/18 (89 %) patients. The evaluation of the mean BAALC expression levels in the pooled groups of children and adults with isolated findings of either inv(16) or t(8;21) showed the decrease of the BAALC-e LHSC mass only in children (p = 0.049). The comparison of the mean WT1 expression levels in the pooled groups of children and adults with isolated and additional chromosomal abnormalities revealed their significant decrease in patients with complicated variants (p = 0.023).
 Conclusion. The case reports provided in this paper show that the molecular monitoring with serial measurements of fusion genes and BAALC gene expression levels in CBF+ AML patients can lay the basis for further improvement of personalized treatment strategies for these patients. In all likelihood, parallel measurements of the above gene expression levels will allow to establish the framework for decision-making concerning treatment extent and timely HSC transplantation.

Comparing the efficiency of forward and backward contact tracing.

Tracing potentially infected contacts of confirmed cases is important when fighting outbreaks of many infectious diseases. The COVID-19 pandemic has motivated researchers to examine how different contact tracing strategies compare in terms of effectiveness (ability to mitigate infections) and cost efficiency (number of prevented infections per isolation). Two important strategies are so-called forward contact tracing (tracing to whom disease spreads) and backward contact tracing (tracing from whom disease spreads). Recently, Kojaku and colleagues reported that backward contact tracing was "profoundly more effective" than forward contact tracing, that contact tracing effectiveness "hinges on reaching the 'source' of infection," and that contact tracing outperformed case isolation in terms of cost efficiency. Here we show that these conclusions are not true in general. They were based in part on simulations that vastly overestimated the effectiveness and efficiency of contact tracing. Our results show that the efficiency of contact tracing strategies is highly contextual; faced with a disease outbreak, the disease dynamics determine whether tracing infection sources or new cases is more impactful. Our results also demonstrate the importance of simulating disease spread and mitigation measures in parallel rather than sequentially.

Tandem High-Pressure Crystallography-Optical Spectroscopy Unpacks Noncovalent Interactions of Piezochromic Fluorescent Molecular Rotors.

To develop luminescent molecular materials with predictable and stimuli-responsive emission, it is necessary to correlate changes in their geometries, packing structures, and noncovalent interactions with the associated changes in their optical properties. Here, we demonstrate that high-pressure single-crystal X-ray diffraction can be combined with high-pressure UV-visible absorption and fluorescence emission spectroscopies to elucidate how subtle changes in structure influence optical outputs. A piezochromic aggregation-induced emitter, sym-heptaphenylcycloheptatriene (Ph7C7H), displays bathochromic shifts in its absorption and emission spectra at high pressure. Parallel X-ray measurements identify the pressure-induced changes in specific phenyl-phenyl interactions responsible for the piezochromism. Pairs of phenyl rings from neighboring molecules approach the geometry of a stable benzene dimer, while conformational changes alter intramolecular phenyl-phenyl interactions correlated with a relaxed excited state. This tandem crystallographic and spectroscopic analysis provides insights into how subtle structural changes relate to the photophysical properties of Ph7C7H and could be applied to a library of similar compounds to provide general structure-property relationships in fluorescent organic molecules with rotor-like geometries.

Electrochemical Analysis of Anion Exchange Membrane Water Electrolyzers (AEMWE)

The increase in deployment of renewable electricity has made green hydrogen production an attractive solution for decarbonizing energy systems. The prominent technologies currently deployed are the proton exchange membrane water electrolyzers (PEMWE) and alkaline water electrolyzers (AWE). The PEMWE technology uses platinum group material (PGM) catalysts, coated onto fluorinated Nafion® polymer membranes and needs specially treated titanium bipolar plates, reaching current densities of greater than 2 A cm-2. The AWE technology, in contrast, uses cheaper materials with a porous diaphragm separator, but the operating current density reaches only <0.5 Acm-2. The anion exchange membrane water electrolyzers (AEMWE) combine the advantages of both the PEMWE and AWE by using hydroxide (OH-) conducting, functionalized styrene-based membranes with non-PGM electrocatalysts, reaching current densities of >1 Acm-2.In this study, a membrane electrode assembly (MEA) consisting of Sustainion® X37-50 Grade RT membranes and non-PGM hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts are fabricated and analyzed for performance. NiFe2O4 (Merk) was chosen as the OER electrocatalyst and spray-coated on the sintered 316L stainless steel fibre (dioxide materials). On the counter side, NiFeCo (USnano) as HER electrocatalyst was spray coated on the molded graphite layer 370 (MGL370- fuelcellstore) porous transport layer. A catalyst loading of 3 mg cm-2 is obtained for both HER and OER electrodes. The fabricated MEA of 1x1cm2 is firstly tested for performance in a inhouse setup, using current density-voltage scans (j-V) using Zahner Zennium X electrochemical workstation. Consequently, electrochemical impedance spectroscopy (EIS) is performed in pseudo-galvanostatic mode. The perturbation amplitude is adjusted such that a linear region of the j-V curve is probed. The fuel electrode and air electrode contributions to the overall MEA performance are distinguishable due to the twin reference electrode configuration. The half cell-MEA contributions are further analyzed by performing parallel impedance measurements between the i) Reference electrode – cathode, ii) Reference electrode - Anode and iii) full-cell operation at predetermined current-density biases. These type of investigation gives deeper insight to the fuel electrode and the air electrode processes. The quality of the EIS spectra is analyzed using Kramers Krönig residual tests.A sensitivity analysis on the MEA is performed by changing impedance-effecting parameters such as temperature, operating current density and potassium hydroxide (KOH) concentration. Further, post-test characterization of the electrode substrates is performed to identify affected parameters through XPS, Raman spectroscopy, SEM-EDX and XRD techniques. The parallel impedance measurements confirms the presence of anodic, cathodic and low-frequency diffusion processes in real time.

Characterising personal, household, and community PM2.5 exposure in one urban and two rural communities in China

BackgroundCooking and heating in households contribute importantly to air pollution exposure worldwide. However, there is insufficient investigation of measured fine particulate matter (PM2.5) exposure levels, variability, seasonality, and inter-spatial dynamics associated with these behaviours. MethodsWe undertook parallel measurements of personal, household (kitchen and living room), and community PM2.5 in summer (May–September 2017) and winter (November 2017-Janauary 2018) in 477 participants from one urban and two rural communities in China. After stringent data cleaning, there were 67,326–80,980 person-hours (ntotal = 441; nsummer = 384; nwinter = 364; 307 had repeated PM2.5 data in both seasons) of processed data per microenvironment. Age- and sex-adjusted geometric means of PM2.5 were calculated by key participant characteristics, overall and by season. Spearman correlation coefficients between PM2.5 levels across different microenvironments were computed. FindingsOverall, 26.4 % reported use of solid fuel for both cooking and heating. Solid fuel users had 92 % higher personal and kitchen 24-h average PM2.5 exposure than clean fuel users. Similarly, they also had a greater increase (83 % vs 26 %) in personal and household PM2.5 from summer to winter, whereas community levels of PM2.5 were 2–4 times higher in winter across different fuel categories. Compared with clean fuel users, solid fuel users had markedly higher weighted annual average PM2.5 exposure at personal (78.2 [95 % CI 71.6–85.3] μg/m3 vs 41.6 [37.3–46.5] μg/m3), kitchen (102.4 [90.4–116.0] μg/m3 vs 52.3 [44.8–61.2] μg/m3) and living room (62.1 [57.3–67.3] μg/m3 vs 41.0 [37.1–45.3] μg/m3) microenvironments. There was a remarkable diurnal variability in PM2.5 exposure among the participants, with 5-min moving average from 10 μg/m3 to 700–1200 μg/m3 across different microenvironments. Personal PM2.5 was moderately correlated with living room (Spearman r: 0.64–0.66) and kitchen (0.52–0.59) levels, but only weakly correlated with community levels, especially in summer (0.15–0.34) and among solid fuel users (0.11–0.31). ConclusionSolid fuel use for cooking and heating was associated with substantially higher personal and household PM2.5 exposure than clean fuel users. Household PM2.5 appeared a better proxy of personal exposure than community PM2.5.

Wood-density has no effect on stomatal control of leaf-level water use efficiency in an Amazonian forest.

Forest disturbances increase the proportion of fast-growing tree species compared to slow-growing ones. To understand their relative capacity for carbon uptake and their vulnerability to climate change, and to represent those differences in Earth system models, it is necessary to characterise the physiological differences in their leaf-level control of water use efficiency and carbon assimilation. We used wood density as a proxy for the fast-slow growth spectrum and tested the assumption that trees with a low wood density (LWD) have a lower water-use efficiency than trees with a high wood density (HWD). We selected 5 LWD tree species and 5 HWD tree species growing in the same location in an Amazonian tropical forest and measured in situ steady-state gas exchange on top-of-canopy leaves with parallel sampling and measurement of leaf mass area and leaf nitrogen content. We found that LWD species invested more nitrogen in photosynthetic capacity than HWD species, had higher photosynthetic rates and higher stomatal conductance. However, contrary to expectations, we showed that the stomatal control of the balance between transpiration and carbon assimilation was similar in LWD and HWD species and that they had the same dark respiration rates.

Evaluating the plasma interleukin-1 beta and interleukin-8 levels in patients with chronic obstructive pulmonary diseases following treatment with allogeneic mesenchymal stem cell derived from umbilical cord tissues and platelet rich plasma

Chronic obstructive pulmonary disease (COPD) is a common disease which negatively affects living quality and longevity of patients. Unfortunately, current COPD treatments are not radical. COPD is characterized by persistent neutrophil infiltrations mediated by inflammatory cytokines including interleukin (IL)-1β and IL-8 in the airway. Mesenchymal stem cells (MSCs) have been proven to suppress inflammation, modulate the immune system and can be regenerative. Allogeneic MSCs have been used to treat COPD patients across the world and produced positive clinical outcomes. In this study, we evaluated plasma IL-1β and IL-8 concentrations in 10 stage-D COPD patients before being transplanted with allogeneic MSCs derived from umbilical cord tissues (UC-MSCs) activated by platelet-rich plasma (PRP) and at 4 follow- ups (after 1, 3, 7, 12 months), as well as determined their associations with COPD clinical and sub-clinical parameters. Plasma IL-1β and IL-8 concentrations were measured using Multiplex Immunoassay. We found that plasma IL-8 levels were significantly reduced from 3.2 to 1.9 pg/ml after 12 months of treatment which is accompanied by the notable decrease in C-reactive protein (CRP). Exacerbation episodes were significantly decreased from 3 to 1. Plasma IL-1β levels were positively correlated with IL-8 levels and white blood cell (WBC) levels. Parallel measurements of plasma IL-1β and IL-8 may help assess the disease progression of COPD patients after the treatment with UC- MSCs and PRP. Blockage of IL-1β or IL-8 could be a valid strategy for the prevention and control of COPD.

Dual Modulator of ASIC Channels and GABAA Receptors from Thyme Alters Fear-Related Hippocampal Activity.

Acid-sensing ion channels (ASICs) are proton-gated ion channels that mediate nociception in the peripheral nervous system and contribute to fear and learning in the central nervous system. Sevanol was reported previously as a naturally-occurring ASIC inhibitor from thyme with favorable analgesic and anti-inflammatory activity. Using electrophysiological methods, we found that in the high micromolar range, the compound effectively inhibited homomeric ASIC1a and, in sub- and low-micromolar ranges, positively modulated the currents of α1β2γ2 GABAA receptors. Next, we tested the compound in anxiety-related behavior models using a targeted delivery into the hippocampus with parallel electroencephalographic measurements. In the open field, 6 µM sevanol reduced both locomotor and θ-rhythmic activity similar to GABA, suggesting a primary action on the GABAergic system. At 300 μM, sevanol markedly suppressed passive avoidance behavior, implying alterations in conditioned fear memory. The observed effects could be linked to distinct mechanisms involving GABAAR and ASIC1a. These results elaborate the preclinical profile of sevanol as a candidate for drug development and support the role of ASIC channels in fear-related functions of the hippocampus.

Estimation of Aerosol Layer Height from OLCI Measurements in the O2A-Absorption Band over Oceans

The aerosol layer height (ALH) is an important parameter that characterizes aerosol interaction with the environment. An estimation of the vertical distribution of aerosol is necessary for studies of those interactions, their effect on radiance and for aerosol transport models. ALH can be retrieved from satellite-based radiance measurements within the oxygen absorption band between 760 and 770 nm (O2A band). The oxygen absorption is reduced when light is scattered by an elevated aerosol layer. The Ocean and Land Colour Imager (OLCI) has three bands within the oxygen absorption band. We show a congruent sensitivity study with respect to ALH for dust and smoke cases over oceans. Furthermore, we developed a retrieval of the ALH for those cases and an uncertainty estimation by applying linear uncertainty propagation and a bootstrap method. The sensitivity study and the uncertainty estimation are based on radiative transfer simulations. The impact of ALH, aerosol optical thickness (AOT), the surface roughness (wind speed) and the central wavelength on the top of atmosphere (TOA) radiance is discussed. The OLCI bands are sufficiently sensitive to ALH for cases with AOTs larger than 0.5 under the assumption of a known aerosol type. With an accurate spectral characterization of the OLCI O2A bands better than 0.1 nm, ALH can be retrieved with an uncertainty of a few hundred meters. The retrieval of ALH was applied successfully on an OLCI dust and smoke scene. The found ALH is similar to parallel measurements by the Tropospheric Monitoring Instrument (TROPOMI). OLCI’s high spatial resolution and coverage allow a detailed overview of the vertical aerosol distribution over oceans.

Temperature-dependent determination of NO2 dimerization reaction based on dual-comb spectroscopy.

Dimerization reactions play a critical role in various fields of research, including cell biology, biomedicine, and chemistry. In particular, the dimerization reaction of 2NO2⇌N2O4 has been extensively applied in pollution control and raw material preparation. Spectroscopy, as a powerful tool for investigating molecular structures and reaction kinetics, has been increasingly employed to study dimerization reactions in recent years. In this study, we successfully demonstrated the application of dual-comb spectroscopy (DCS) to analyze NO2 dimerization reactions, making the first report on the application of this technique in this context. Parallel measurements of NO2 and N2O4 fingerprints spectra with high resolution at 3000 cm-1 was performed, benefiting from the unprecedented broadband and high-precision capability of DCS. The absorption cross-sections of N2O4 from 296 to 343 K was obtained from the measured spectra, which contributes to further research on the molecular spectrum of N2O4. These results demonstrate the potential of DCS for studying the dimerization reaction mechanism.

Towards a Measure of Local Legislative Professionalism

Municipal policy leadership is shared between managers, city councilors, and mayors, all of whom vary in institutional power and resources across municipalities. Corresponding with their importance, scholars have established consistent measures of professionalism for Mayors and City Managers. Unfortunately, there is no parallel measure of professionalism for city councils. After reviewing the role of councils in local policy leadership and establishing the need for a systematic measure of local legislative professionalism, this paper uses data from over 4,000 municipalities to develop a measure of legislative professionalism for city councils. We demonstrate that considerable variation exists in levels of professionalism among local legislatures and describe the implications of this variation for questions of municipal policy leadership and local legislative representation.

A universal surrogate matrix assay for urea measurement in clinical pharmacokinetic studies of respiratory diseases.

In pharmacokinetic studies for respiratory diseases, urea is a commonly used dilution marker for volume normalization of various biological matrices, owing to the fact that urea diffuses freely throughout the body and is minimally affected by disease states. In this study, we developed a convenient liquid chromatography-tandem mass spectrometry (LC-MS/MS) surrogate matrix assay for accurate urea quantitation in plasma, serum and epithelial lining fluid. Different mass spectrometer platforms and ionization modes were compared in parallel. The LC method and mass spectrometer parameters were comprehensively optimized to reduce interferences, to smooth the baseline and to maximize the signal-to-noise ratio. Saline was selected as the surrogate matrix, and its suitability was confirmed by good parallelism and accurate quality control sample measurements. Reliable and robust assay performance was demonstrated by precision and accuracy, dilution integrity, sensitivity, recovery and stability, all of which met bioanalysis requirements to support clinical studies. The assay performance was also verified and better understood by comparing it with a colorimetric assay and to a surrogate analyte assay. The newly developed surrogate matrix assay has the potential to be further expanded for urea quantitation in numerous physiological matrices.

Abstract P1104: Mantarray 3D Engineered Muscle Tissue Platform Demonstrates Clinically-relevant Disease Stratification Of An In Vitro Human Duchenne Muscular Dystrophy Model

Accurately modeling disease in vitro is vital for the development of new treatment strategies and therapeutics. For cardiac diseases, direct assessment of contractile output is the “ultimate phenotype” and a reliable metric to study overall tissue function, as other ‘proxy’ measurements or biomarkers are not good predictors of muscle strength. Human 3D engineered heart tissues (EHTs) from induced pluripotent stem cells hold great potential for modeling contractile function. However, the bioengineering strategies required to generate these predictive models present limitations for many investigators. Here, we have developed an instrument platform that utilizes 3D EHTs in conjunction with a label-free, magnetic sensing array (Mantarray). The platform enables facile and reproducible fabrication of 3D EHTs using virtually any cell source and is coupled with parallel direct measurement of contractility. This approach enables clinically relevant functional measurements of muscle, stratification of healthy vs. diseased muscle phenotypes, and facilitates therapeutic modality-agnostic compound safety and efficacy screening. We present a 3D model of Duchenne muscular dystrophy (DMD) that utilizes EHTs formed from an isogenic pair of healthy and diseased cells. DMD tissues display functional deficits across numerous metrics of contractility, including force and relaxation kinetics, though beat rate remains unchanged. EHTs remain functional over months in culture and provide a large experimental window to not only study therapeutic effect, but also disease phenotypes that may present at later stages of development and maturity. We show both acute and chronic effects of compounds in EHTs, including a drug (BMS-986094) that failed clinical trials due to unanticipated cardiotoxicity. These data demonstrate a first-and-only commercial platform that integrates individual, well-based control of electrical stimulation across a 24-well plate of tissues to pace muscle constructs, model force-frequency, and enable exercise regimens or damage protocols. Stimulation is coupled with automated assessment of muscle contraction, providing an inclusive, medium-throughput platform for disease modeling and therapeutic discovery.

Childhood ADHD With and Without Co-occurring Internalizing/Externalizing Problems: Prospective Predictions of Change in Adolescent Academic and Social Functioning.

Internalizing and externalizing problems predict poor academic and social outcomes. However, ADHD co-occurs with internalizing and externalizing problems and is itself a risk factor, thus preventing precise inferences. This study evaluated childhood anxiety, depression, and aggression as predictors of change in adolescent academic and social outcomes, including moderation by childhood ADHD. 182 ethnically-diverse 5- to 11-year-old youth with (54.7%) and without (45.3%) ADHD completed a separate baseline and 6- to 7-year prospective follow-up assessment, consisting of parallel measures across youth psychopathology, academic functioning (i.e., academic achievement, school competence), and friendship quality domains. Whereas childhood ADHD inversely predicted academic competence, depression and aggression uniquely predicted worsening friendship quality. Interestingly, anxiety was unrelated to change in academic and friendship outcomes; similarly, neither ADHD, depression, nor aggression predicted change in objectively-measured academic achievement from a standardized assessment. Implications for intervention and prevention are considered, including school-based approaches, within a developmental psychopathology framework.

Fractionation as the main method for smoked tobacco products identification

Smokeless tobacco products are products that do not require a pyrolysis process and / or the production of tobacco aerosol (smoke) at the time of use. In the absence of data on the toxicological risks of smokeless tobacco, their consumption is potentially on the rise. The variety of non-smoking tobacco products creates certain problems in identifying chewing tobacco and sucking tobacco (banned for sale in the Russian Federation) as products that are identical in terms of physiological effects, method of consumption, and component composition. A methodology has been developed for a comprehensive assessment of non-smoking products, including the determination of consumer properties and technological indicators by instrumental methods, as well as the determination of the level of toxic components (nicotine, TSNA, B(a)P). The difference between the types of smokeless tobacco is mainly in the granulometric composition of the product: snus – finely ground tobacco, chewing tobacco – snatches of tobacco with a removed middle vein. Identification indicators have been determined: the presence of raw tobacco, the size of its particles and the number of large fragments in the finished product. The presence of raw tobacco can be determined by optical microscopy and/or luminescent analysis, and the quantitative content can be determined by sieve analysis. The quantitative content of the coarse fraction in chewing tobacco (not less than 15 %) is the main indicator of the product. The use of the fractionation method makes it possible to differentiate between sucking and chewing tobacco. A «Method for determining the fractional composition of non-smoking tobacco products for oral consumption by the method of sieve analysis» was developed (Certificate No. 022-01.00281-2013-2022). To certify the methodology, a set of studies was carried out, the data were obtained as a result of five parallel measurements by three performers for each sample. The technique is registered in the State Register of Measuring Instruments (FR.1.31.2022.43935 of 09/02/2022). Technological indicators of SLT samples were established: humidity (11,4-53,3) %, pH level 5,7-9,7, coarse fraction content (0,4-56,9) %, dust fraction content (0,2-76,3) %. The results of identification of commercial samples of a segmental product are presented.

Application of Ultrasonic Methods for Evaluation of High-Pressure Physicochemical Parameters of Liquids

An emerging ultrasonic technology aims to control high-pressure industrial processes that use liquids at pressures up to 800 MPa. To control these processes it is necessary to know precisely physicochemical properties of the processed liquid (e.g., Camelina sativa oil) in the high-pressure range. In recent years, Camelina sativa oil gained a significant interest in food and biofuel industries. Unfortunately, only a very few data characterizing the high-pressure behavior of Camelina sativa oil is available. The aim of this paper is to investigate high pressure physicochemical properties of liquids on the example of Camelina sativa oil, using efficient ultrasonic techniques, i.e., speed of sound measurements supported by parallel measurements of density. It is worth noting that conventional low-pressure methods of measuring physicochemical properties of liquids fail at high pressures. The time of flight (TOF) between the two selected ultrasonic impulses was evaluated with a cross-correlation method. TOF measurements enabled for determination of the speed of sound with very high precision (of the order of picoseconds). Ultrasonic velocity and density measurements were performed for pressures 0.1–660 MPa, and temperatures 3–30°C. Isotherms of acoustic impedance Z_a, surface tension σ and thermal conductivity k were subsequently evaluated. These physicochemical parameters of Camelina sativa oil are mainly influenced by changes in the pressure p, i.e., they increase about two times when the pressure increases from atmospheric pressure (0.1 MPa) to 660 MPa at 30°C. The results obtained in this study are novel and can be applied in food, and chemical industries.

Study on the Measurement Technique and Judgment Procedure of Ultrasonic Corona Imaging Equipment

Corona discharge is a phenomenon wherein gas on the surface of electrical equipment is ionised. Severe ionisation can lead to insulation breakdown and cause equipment damage. Consequently, non-contact portable devices are employed to detect corona discharge in real time while the electrical equipment is pressurised. Recently, several devices capable of visualising corona discharge phenomena occurring in the ultrasonic region have been developed. However, these devices are primarily used for scanning purposes to verify the occurrence of partial discharge, as detailed guidelines for operating the equipment in real-world field conditions are yet to be established. Therefore, this study proposes a measurement technique for utilising ultrasonic corona imaging diagnostic equipment in the field. This technique involves the use of corona discharge electrodes and aged epoxy insulator samples. First, the performance of the ultrasonic corona imaging diagnostic equipment based on environmental conditions was evaluated by varying the distance, frequency, temperature, and humidity using the corona discharge electrodes. Then, parallel measurements were conducted with a high-frequency current transformer sensor on epoxy insulator samples subjected to simple ageing, cracking, and partial surface damage, and the results were analysed. Finally, an efficient measurement technique, including equipment operation procedures, was proposed by integrating the measurement results.

Validation of novel multiplex technologies

Cytokine and chemokine levels in body fluid provide information of altered conditions in patients. The parallel analysis of multiple factors, such as cytokines, from small sample sizes is an interesting approach for the assessment of in vivo activation signatures and functionality after ex vivo stimulation. One interesting application is for therapy monitoring— such as safety data, pharmacodynamics, evidences for mode-of-action and side effects—which is particularly useful for accompanying early phase clinical trials. There are different platforms for multiplex analyses of ligands available. An assay validation of three different platforms for simultaneous quantification of cytokines (Luminex Bio-Plex® 200, Meso Scale Discovery® and Ella® ) was performed in this study. The comparison of multiplex platforms, which use different ways of achieving parallel measurements of biomarkers, reveal the performance strengths and weaknesses. We showed examples of in-house assessments of intra- and inter-assay variations, determination of the range and recovery of classical immunological serum markers and discussed advantages and disadvantages of these three platforms in relation to the question addressed. All the platforms show low intra-assay variances. The Luminex platform shows a high inter-assay variance for the majority of parameters, whereas the MSD and Ella platforms show low inter-assay variances.