Miracle-dz/UniFAR-FTUs huggingface dataset:
FIRST TIME-DEPENDENT STUDY OF H2 AND H ORTHO–PARA CHEMISTRY IN THE DIFFUSE INTERSTELLAR MEDIUM: OBSERVATIONS MEET THEORETICAL PREDICTIONS

The chemistry in the diffuse interstellar medium (ISM) initiates the gradual increase of molecular complexity during the life cycle of matter. A key molecule that enables build-up of new molecular bonds and new molecules via proton donation is H. Its evolution is tightly related to molecular hydrogen and thought to be well understood. However, recent observations of ortho and para lines of H2 and H in the diffuse ISM showed a puzzling discrepancy in nuclear spin excitation temperatures and populations between these two key species. H, unlike H2, seems to be out of thermal equilibrium, contrary to the predictions of modern astrochemical models. We conduct the first time-dependent modeling of the para-fractions of H2 and H in the diffuse ISM and compare our results to a set of line-of-sight observations, including new measurements presented in this study. We isolate a set of key reactions for H and find that the destruction of the lowest rotational states of H by dissociative recombination largely controls its ortho/para ratio. A plausible agreement with observations cannot be achieved unless a ratio larger than 1:5 for the destruction of (1, 1)- and (1, 0)-states of H is assumed. Additionally, an increased cosmic-ray ionization rate to 10−15 s−1 further improves the fit whereas variations of other individual physical parameters, such as density and chemical age, have only a minor effect on the predicted ortho/para ratios. Thus, our study calls for new laboratory measurements of the dissociative recombination rate and branching ratio of the key ion H under interstellar conditions.
A chromatographic study of the diffusion of N2,CH4 and binary CH4‐N2 mixtures in 4A molecular sieve

The kinetics and equilibrium of sorption of CH4, N2 and binary CH4–N2 mixtures in 4A molecular sieve have been studied by a chromatographic method. The equilibrium isotherms and zeolitic diffusivities, determined with a helium carrier, show good agreement with previous gravimetric data. Counter-diffusion in the binary adsorbed phase was investigated using a mixed carrier gas and following the response to a small step change from a previously established equilibrium position. The dynamic response curves for the binary system could be satisfactorily interpreted on the assumption that both components in the mixture diffuse independently with the same intrinsic mobilities as for the single component systems. On a etudie, en employant une methode chromatographique, la cinetique et l'equilibre de sorption de CH4 et N2 et de melanges binaires de ces deux gaz, sur un tamis moleculaire 4A. Les isothermes d'equilibre et les diffusivites dans les zeolithes, qu'on a determinees avec de l'helium comme gaz porteur, ont bien concorde avec les resultats gravimetriques anterieurs. On a etudie la contre-diffusion dans la phase binaire adsorbee, en employant un gaz porteur mixte et en suivant la reponse a une demande echelon de faible amplitude par rapport a une position d'equilibre etablie anterieurement. On a pu interpreter d'une maniere satisfaisante les courbes de reponse dynamiques correspondant au systeme binaire, en supposant que les deux composants dud melange diffusent independamment avec les měmes mobilites intrinseques que dans le systeme a un seul composant.
In vitro Cytotoxicity of Australian Tea Tree Oil using Human Cell Lines

Abstract Cytotoxicity of Australian tea tree oil (oil of Melaleuca alternifolia) and its major oxygenated monoterpenes: terpinen-4-ol, 1,8-cineole and α-terpineol were investigated using the MTS [(3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)] assay at two exposure times: 4 and 24 h on five different human cell lines. These cell lines included: Hep G2, a heptaocellular carcinomic human cell line; HeLa, an epithelioid carcinomic cell line; MOLT-4, a human lymphoblastic leukaemic T-cell line; K-562, a human chronic myelogenous leukaemia cell line; and CTVR-1, an early B-cell line from the bone marrow cells of a patient with acute myeloid leukaemia. The overall rating for cytotoxicity of tea tree oil and its components was α-terpineol>tea tree oil>terpinen-4-ol> 1,8-cineole and with comparison with the controls used mercuric chloride>tea tree oil>aspirin. Antimicrobial activity (MICs) displayed a similar pattern where α-terpineol>terpinen-4-ol>tea tree oil> 1,8-cin.
Monte Carlo simulations of the transport of laser‐ablated atoms in a diluted gas

The interaction between gas clouds, created by laser ablation, and a diluted gas background is studied by means of Monte Carlo simulations. More specifically, the effect of elastic collisions between ablated atoms and background gas atoms on the kinetic energy and spatial distributions of atoms arriving at the substrate is investigated. The pressure regime under study is typically the range 0.1–200 mTorr. Thermalization is observed in a pressure range that varies over two orders of magnitude, dependent on the initial energy of the atoms and the ratio of the background gas and ablated atom molecular masses. During the first stages of thermalization, forward focusing is found to occur.
Automated capillary GC determination of local anaesthetics in plasma samples with supported liquid membranes for sample preparation

An on-line automatic system has been developed for the determination of local anaesthetics in untreated blood plasma samples. It utilizes supported liquid membrane extraction for initial sample preparation, a solid phase column for phase switching, and a capillary gas chromatographic final analysis. The extraction procedure is very selective, as no other compounds than the analytes are observed in the resulting chromatograms at low nanogram-per-milliliter concentration levels. The detection limits are about 1 ng/mL, and the precision is around 5%. The system is fully automated and permits the analysis of ca. 50 samples per day. © 1998 John Wiley & Sons, Inc. J Micro Sep10: 107–113, 1998
Theory of size distribution of associating polymer aggregates. I. Spherical aggregates

We examine the stability of spherical, micellelike aggregates composed of long‐chain, polymeric surfactants in dilute solution. The associating polymers consist of long, unbranched hydrophobic chains with one polar end‐group per chain and are in a good solvent for the chains. Although the head groups prefer to aggregate in the nonpolar solvent and thus stabilize the spherical structure, the energy associated with the chain repulsions tends to destabilize the aggregates as the chain length increases. For a liquid‐drop model of the head interactions, the average aggregation number evolves smoothly towards zero as the chain length increases. An alternate model of the head region, which assumes a preferred head‐packing geometry, results in the ultimate destabilization of the spherical aggregate as the chain length is increased beyond a certain threshold. Both models yield a critical micelle concentration (CMC) at low values of the polymer concentration.
Sensory Evaluation of Suspected Harmonia axyridis-tainted Red Wine Using Untrained Panelists

Abstract Washington State Merlot suspected of Harmonia axyridis taint (Multicolored Asian Lady Beetle; MALB) was evaluated for its aroma, flavor and mouthfeel sensory properties using a directional paired difference test and a control wine. Compared to the control wine, the potentially MALB-tainted wine had a more vegetal and musty/earthy aroma accompanied with less fruity aroma, a stronger green pepper flavor and more sour taste (p ≤ 0.05). Panelists significantly preferred the aroma and flavor of the control wine compared to the wine suspected of being MALB-tainted (p ≤ 0.05). These results indicate the influence of MALB taint on red wine properties and the potential of consumers to reject MALB-tainted wine.
Cross-Linking of Multi-Walled Carbon Nanotubes with Polyethylene Glycol

In this paper a new approach to cross-link two individual multi-walled carbon nanotubes (MWCNTs) by a nucleophilic substitution of brominated MWCNTs using polyethylene glycol anion was introduced. The functionalized MWCNTs were characterized using thermogravimetric analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. It is found that polyethylene glycol act as cross-linking agents to interconnect or cross-link the MWCNTs within and among the bundles, as demonstrated by TEM analysis, and few defects will be induced to the nanotube sidewalls. After cross-linking of PEG, the functionalized MWCNTs are still insoluble in any solvent; however, the morphologies of the cross-linked MWCNTs were largely intact, undoubtedly which will provide a useful way to construct nanoscale devices with MWCNTs in the future.
Temperature and Electron Density Measurements of Laser-Induced Plasmas in Air at Elevated Pressures

ABSTRACT We present time-resolved spectroscopic measurements of 1064-nm Nd:YAG laser-produced plasmas in air at pressures from 0.85 to 48.3 bar. We report temperatures and electron number densities of the plasmas at times between 200 ns and 3 µs after the plasma onset. Neutral atomic oxygen lines at 715 nm and 777 nm are used for temperature measurement through a Boltzmann analysis. Electron number density is measured using Stark broadened atomic hydrogen (Hα) line at 656 nm. We compare experimental results with modeling results obtained from using Taylor-Sedov blast-wave theory coupled with local thermal equilibrium composition calculations.
Amphiphilic copolymers in aqueous medium: Characterization of the structure of the hydrophobic microdomains

The behaviour of new cationic amphiphilic copolymers derived from 3-vinylpyridine was studied in aqueous medium. The formation of hydrophobic microdomains was evidenced by fluorescence spectroscopy using a molecular rotor as a fluorescent probe and their structure was visualized by cryo-transmission electron microcospy (Cryo-TEM). The parameters (shape and size) obtained from Cryo-TEM were discussed in relation to the copolymers composition and to the local viscosity defined by the rotor fluorescence quantum yield.
High-Sensitivity Gas Sensors Based on Gas-Permeable Liquid Core Waveguides and Long-Path Absorbance Detection

A new fluoropolymer is proposed as the basis of a novel class of sensors. The devices are based on selective chromogenic reactions and in situ long-path optical absorbance measurement. The polymer is transparent from 200 to 2000 nm and has the lowest known refractive index (RI) of any synthetic polymer. The RI is less than that of water. A tube of this material, filled with an aqueous solution (or virtually any other liquid), behaves as a liquid core optical fiber. As a result, long-path length optical cells are possible without significant loss of light. The material is highly permeable to a number of trace gases of environmental interest. Relative to common poly(tetrafluoroethylene) (PTFE)-type Teflon, the new amorphous fluoropolymer (Teflon AF 2400) is more than 3 orders of magnitude more permeable to many gases. If a Teflon AF tube is filled with a reagent that responds to a gaseous analyte by undergoing a change that is spectroscopically detectable, an unusually versatile, sensitive, and inexpensive .
Analysis of the hydrogen bonding and vibrational spectra of supercritical model water by molecular dynamics simulations

The properties of hydrogen bond networks in ambient, supercritical, and stretched model water at temperatures between 573 K and 873 K and densities between 0.1 g/cm3 and 1 g/cm3 have been investigated by molecular dynamics simulation. A flexible simple point charged pair potential model has been used and, after comparing two hydrogen bond definitions, a pure geometrical criterion has been employed. The structure found agrees well with recent experimental data. The presence of hydrogen bonds has been detected at every supercritical state, although the tetrahedral structure typical of liquid water at room temperature is substituted in supercritical model water by chains of hydrogen-bonded molecules allowing cavities. The calculated OH stretching peak shifts toward higher values when changing from ambient to supercritical conditions. Nevertheless, under such changes bending and libration bands are displaced to lower frequencies. The cage effect typical of liquid water at ambient conditions does not appear in the supercritical states.
LIF and fast imaging plasma jet characterization relevant for NTP biomedical applications

In the field of biomedical application, many publications report on non-thermal plasma jet potentialities for cell behaviour modifications in cancer treatment, wound healing or sterilization. However most previous plasma jet characterizations were performed when jets expend freely in air. Only recently has the influence of the targeted surface been properly considered. In this work, modifications induced by various types of targets, mimicking the biological samples, in the plasma propagation and production of hydroxyl radicals are evidenced through time-resolved intensified charge-coupled device imaging and laser-induced fluorescence (LIF) measurements. A LIF model, also specifically dedicated to estimate air and water penetration inside the jet, is used and proves to be well adapted to characterize the plasma jet under biomedical application conditions. It is shown that the plasma produced by the plasma gun counter-propagates after impinging the surface which, for the same operating parameters, leads to an increase of almost one order of magnitude in the maximum OH density (from ∼2 × 1013 cm−3 for open-air propagation to ∼1 × 1014 cm−3 for a grounded metal target). The nature of the target, especially its electrical conductivity, as well as gas flow rate and voltage amplitude are playing a key role in the production of hydroxyl radicals. The strong interplay between gas flow dynamics and plasma propagation is here confirmed by air and water distribution measurements. The need for a multi-diagnostic approach, as well as great care in setting up the in situ characterization of plasma jets, is here emphasized. Special attention must not only be paid to voltage amplitude and gas flow rate but also to the nature, humidity and conductivity of the target.
Water-soluble copolymers. 30. Effects of molecular structure on drag reduction efficiency

Preparation et etude des proprietes de reduction de la trainee de copolymeres de l'acrylamide avec l'acrylate de sodium, le 2-acrylamido-2-methylpropanesulfonate de methyle, le 3-acrylamido-3-methyl-butanoate de sodium et le N-[(2-acetyl-1,1-dimethyl) ethyl] acrylamide de compositions differentes. Developpement d'une methode d'analyse des performances de reduction de la trainee par des polymeres. Les resultats montrent que l'efficacite des polymeres depend de leur structure et demontrent l'importance des interactions polymere-solvant
Improving hydrogen isotope ratio measurements for on‐line chromium reduction systems

Recent advances in on-line metal [U, Mn, Cr] reduction systems for the automated analysis of δDVSMOW in water and organic solvents greatly increases sample throughput. However, several sources of uncertainty are inherent in these systems, including analytical reproducibility, fractionation of reference gas in the inlet system, and memory effects, as well as error introduced during data normalization that must be quantified. A careful consideration of these sources of uncertainty suggests that accuracy to <1‰ may be difficult to achieve due to the combined effects of analytical error and uncertainty in the calibration of secondary laboratory standards. However, for internally consistent data sets, it may be possible to measure relative differences between samples at the ∼0.5‰ level or below. In addition to describing methods for data reduction, strategies for minimizing and managing uncertainty are presented along with a recipe for greatly increasing reactor life in Cr-reduction systems. Increased reactor life reduces consumable costs by a factor of 10. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of metal and ligand types on stacking interactions of phenyl rings with square-planar transition metal complexes

In order to find out whether metal type influences the stacking interactions of phenyl rings in square-planar complexes, geometrical parameters for Cu, Ni, Pd and Pt complexes, with and without chelate rings, were analyzed and compared. By searching the Cambridge Structural Database, 220 structures with Cu complexes, 211 with Ni complexes, 285 with Pd complexes, and 220 with Pt complexes were found. The results show that the chelate ring has a tendency to make the stacking interaction with the phenyl ring independent of metal type in the chelate ring. However, there are some differences among metals for complexes without a chelate ring. There are a number of structures containing Pd and Pt complexes, without chelate rings, that have short carbon-metal distances and parallel orientations of the phenyl ring with respect to the coordination plane. It was found that some of these complexes have a common fragment, CN, as a part of the ligands. This indicates that the CN supports stacking interactions of square planar complexes with the phenyl ring.
Low-temperature synthesis of hexamethylenetetramine-stabilised ZnS nanoparticles and its photocatalytic properties

ZnS nanoparticles have been synthesised at low temperature by short reaction (80°C for 2 h) via wet chemical route. The nanoparticles were stabilised using hexamethylenetetramine (HMTA) as surfactant in aqueous solution. The average particle size calculated from X-ray diffraction studies was about 4 nm with cubic zincblende structure. The presence of HMTA in the synthesised ZnS nanoparticles was confirmed by FTIR studies. A significant blue shift was observed in the optical absorption band edge for the ZnS nanoparticles as compared to the bulk, indicating a strong quantum confinement. The room temperature photoluminescence (PL) spectrum showed a broad green emission peak at around 502 nm. The photocatalytic property of HMTA-stabilised ZnS nanoparticles were investigated on the decolourisation of methylene blue aqueous solution under UV light irradiation.
Changes in Composition of Nitrogen-15-Labeled Gases during Storage in Septum-Capped Vials

We tested the reliability of 12-mL Exetainers (Labco Ltd., High Wycombe, UK) fitted with bromobutyl rubber septa for the storage of a gas sample containing 15 N-labeled N 2 O and N 2 . The gas mixture was analyzed monthly over a 1-yr storage period by continuous-flow isotope-ratio mass spectrometry (IRMS). After a year the N 2 O concentration had decreased by 30% but the change in 15 N enrichment of N 2 O was not detectable. Accurate determination of the N 2 O concentration was possible up to 1 yr if a calibration gas was stored and analyzed along with the test mixture. This technique has wide applicability because diffusive loss of N 2 O as a fraction of starting concentration was predicted by Fick's Law to be almost independent of concentration above 3 μL L -1 . The rate of decrease in the enrichment of N 2 as measured by the ratio differences for 29/28 and 30/28 was slow. Decreases were not significantly different from time zero values after storage for 8 wk. After 1 yr of storage the losses of 29 N 2 and 30 N 2 significantly lowered the calculated value for the fraction of the N 2 from the labeled pool (d) by about 2% of the initial value, but had no effect on the calculated value for the enrichment of the labeled pool ( 15 X N ). The diffusivity of N 2 O, calculated from loss rate and concentration gradient between Exetainer and atmosphere using Fick's Law, was 40 times higher than that of 29 N 2 or 30 N 2 . Nitrous oxide may have been lost from the Exetainer because of adsorption by the septum as well as diffusion through the septum.
In silico evidences for the binding of phthalates onto human estrogen receptor α, β subtypes and human estrogen-related receptor γ

Being lipophilic xenobiotic chemicals, phthalates from the surrounding environments can easily be absorbed into the biological system, thereby causing various health problems including cancer and endocrine disruption in test animals and also in humans. In the present in silico study employing Glide, Schrödinger Suite 2012, we analysed in detail the binding affinities of 12 commonly used diphthalates and their metabolites (corresponding mono ester and phthalic acid) onto the ligand-binding domain (LBD) of the human estrogen receptor α (hERα), human estrogen receptor β (hERβ) and human estrogen related receptor γ (hERRγ). Natural ligand 17β estradiol (E2), known xenoestrogen bisphenol A, the phytoestrogen genistein, the agonists/antagonists 4-hydroxy tamoxifen and raloxifene were also docked onto these receptors as positive controls for comparing the binding efficiencies with that of phthalates and their metabolites. Results revealed that E2 had less binding affinity to the receptors in comparison to certain phthalates, i.e. maximum binding scores (G score, kcal/mol) were diisononyl phthalate ( − 9.44) to hERα, monophenyl phthalate ( − 8.66) to hERβ and di(2-ethylhexyl)phthalate ( − 9.38) to hERRγ. The most concerned monophthalates established additional H bonds with certain surrounding crucial amino acid residues in the LBD, and thus showed more affinity to all the receptors than even the natural ligand and other well-characterised xenoestrogens as demonstrated in this study. Briefly, this study gives an insight into the virtual binding behaviours of commonly used phthalates and their metabolites onto hERs and hERRγ, which would accelerate further in vitro mechanistic, preclinical and clinical studies on real in vitro or in vivo platforms.
Reliable Determination of Any Water Content of Bitumen and Vacuum Residua. Applications and Validation by Comparison with Known Methodologies

The present study shows how water analysis of bitumen samples produced during in situ combustion or solvent/steam laboratory core flooding experiments is a requisite for a comprehensive understanding of the studied processes. The conceived tetrahydrofuran based Karl Fischer titration technique from a previous study was validated and found advantageous for the purpose, when compared with known azeotropic distillation or nuclear magnetic resonance methodologies.
Optimization of Data Acquisition and Sample Preparation Methods for LC-MS Urine Metabolomic Analysis

Abstract Nowadays, chromatographic methods coupled with mass spectrometry are the most commonly used tools in metabolomics studies. These methods are currently being developed and various techniques and strategies are proposed for the profiling analysis of biological samples. However, the most important thing used to maximize the number of entities in the recorded profiles is the optimization of sample preparation procedure and the data acquisition method. Therefore, ultra high performance liquid chromatography coupled with accurate quadrupoletime- of-flight (Q-TOF) mass spectrometry was used for the comparison of urine metabolomic profiles obtained by the use of various spectral data acquisition methods. The most often used method of registration of metabolomics data acquisition – TOF (MS) was compared with the fast polarity switching MS and auto MS/MS methods with the use of multivariate chemometric analysis (PCA). In all the cases both ionization mode (positive and negative) were studied and the number of the identified compounds was compared. Additionally, various urine sample preparation procedures were tested and it was found that the addition of organic solvents to the sample noticeably reduces the number of entities in the registered profiles. It was also noticed that the auto MS/MS method is the least efficient way to register metabolomic profiles. Graphical Abstract