Miracle-dz/UniFAR-FTUs huggingface dataset:
Control of strength and stability of emulsion-gels by a combination of long- and short-range interactions

This paper discusses the change in phase behavior and mechanical properties of oil-in-water emulsion gels brought about by variation of long- and short-range attractive interactions. The model system studied consisted of oil droplets stabilized by the protein -lactoglobulin (-lg). A long-range depletion attraction was obtained by addition of dextran. At short distances, the interaction is dominated by electrostatic repulsion between the adsorbed layers of -lg. This interaction was varied by addition of Ca2+ ions and by changing the NaCl concentration. Combination of long- and short-range attraction resulted in a substantial decrease in the rate of serum separation and an increase in the emulsion gel modulus at small deformations compared to depletion attraction alone. The flocculation process and the morphology of the flocs were investigated by diffusing wave spectroscopy and confocal scanning laser microscopy. Above a minimum concentration, dextran induced fast depletion flocculation, leading to a network of emulsion droplets. This network quickly collapsed due to gravity. Addition of Ca2+ ions above a minimum concentration induced slow flocculation, and the flocs creamed before a network was formed. Addition of both dextran and Ca2+ ions resulted in a two-step mechanism of emulsion gel formation. A network is quickly formed by depletion flocculation and subsequently the bonds between the emulsion droplets are reinforced by Ca2+ ions. Due to this reinforcement, rearrangements of this network were suppressed resulting in a smaller rate of serum separation.
Accessible analysis of longitudinal data with linear mixed effects models

Longitudinal mouse models are commonly used to study possible causal factors associated with human health and disease. However, the statistical models, such as two-way ANOVA, often applied in these studies do not appropriately model the experimental design, resulting in biased and imprecise results. Here, we describe the linear mixed effects (LME) model and how to use it for longitudinal mice studies. We re-analyze a dataset published by Blanton et al (Science 2016) that modeled mice growth trajectories after microbiome implantation from nourished or malnourished children. We compare the fit and stability of different parameterizations of ANOVA and LME models; most models found the nourished vs. malnourished growth trajectories differed significantly. We show through simulation that the results from the two-way ANOVA and LME models are not always consistent. Incorrectly modeling correlated data can result in increased rates of false positives or false negatives, supporting the need to model correlated data correctly. We provide an interactive Shiny App to enable accessible and appropriate analysis of longitudinal data using LME models.
CH4 emission from different stages of thermokarst formation in Central Yakutia, East Siberia

Abstract The present study was carried out to evaluate the effect of permafrost thawing on methane (CH4) emission from different development stages of thermokarst formation in Central Yakutia, East Siberia. Four stages of thermokarst, “Bullar,”“Dyede,”“Tuumpu” and mature “Alas,” differing in age, depth of depression and water presence, were selected for examination. The emission of CH4 was measured at each thermokarst in forest, dry grassland, wet grassland and on the pond surface. The forest plots were CH4 sinks and uptake ranged from −1 to −34 μg C m−2 h−1. The CH4 fluxes from dry grasslands ranged from −5.4 to 0.9 μg C m−2 h−1, and in wet grasslands CH4 fluxes substantially increased, ranging from 3.6 to 285 μg C m−2 h−1. Pond surfaces had the highest CH4 emissions, ranging from 657 to 8.0 × 103 μg C m−2 h−1. The amount of CH4 stored in the permafrost (up to a depth of 15 m) was estimated to be approximately 0.259 g C m−2. This value was small compared with the current CH4 emission from pond surfaces (4.3–16 g C m−2 growing season−1) in thermokarst depressions. Accordingly, the release of CH4 trapped in the permafrost was not significant compared with the high CH4 emission from the pond surface in young thermokarst depressions. The formation of thermokarst involving permafrost thawing could influence the regional CH4 budget significantly by forming thermokarst wetlands that produce and emit CH4 as a result of current microbial processes under anaerobic conditions.
Mechanism of Photodenitrogenation of Salen Azido-Metal Complexes within the Cavities of Zeolite Y

Salen nitridomanganese(V) and nitridochromium(V) complexes inside zeolite Y have been obtained by photodenitrogenation of encapsulated Mn(III) and Cr(III) azide complexes. The azide ligand was introduced in the preformed metallosalen complex using TMSN3. Supported Mn(III) and Cr(III) azides exhibit room-temperature emission centered at 600 and 575 nm, respectively, which is identical to the emission observed for nitridomanganese(V) and nitridochromium(V) salen. Such emission is not observed in solution. It is concluded that in the zeolite the photodenitrogenation proceeds through adiabatic crossing from the azide excited state surface to the nitrido-excited surface with simultaneous dinitrogen loss.
Effect of Carbonate on Hydroxyapatite Solubility

Carbonate is present in biological apatites (BAp) (enamel, dentine, bone, and pathological calcifications) by substitution at phosphate and hydroxide sites, tending to increase its solubility in comparison with pure hydroxyapatite (HAp). The role of solution carbonate, however, is poorly understood. Using the solid titration method, it was found that the apparent solubility of HAp increased greatly with an increase in pCO2, and was sensitively-dependent at low values. No other phase was formed at the end point except HAp, and in particular no dicalcium phosphate dihydrate (DCPD) was found. However, no carbonate was detected in the end-point solid except for a small amount at pH ∼ 7.4, pCO2 = 0.01−1.0 bar. The implications of these results need further investigation, bearing as they do on a central topic in oral chemistry.
Chemical Behavior of Polycyanoacetylene Radicals on Gaseous and Ice Water: A Computational Perspective

The importance of dust grains coated by water ice has been well recognized in astrophysical chemistry. Accordingly, the adsorption of various closed-shell species onto water ice has been much studied. However, the chemical behavior of free radicals (especially the molecular radicals) on water ice has attracted very little attention, either experimental or theoretical. In this paper, we for the first time investigate the adsorption and evolution of polycyanoacetylene radicals C2n+1N (n = 1-4) on both gaseous and ice water (only C3N for the latter) using computational methods. The reaction of C3N with gaseous H2O seems unlikely to take place in low-temperature space, because of a minute energy barrier for hydrogen abstraction to form HC3N plus OH via the adsorption complex H2O ··· C3N. Yet, this radical-molecule reaction can be effectively catalyzed by water ice. It is shown that the C2n+1N (n = 1-4) radicals possess much higher reactivity toward H2O than the simplest cyano (CN) radical or other well-known radicals. The adsorption of C2n+1N radicals on water ice, simulated by (H2O)3 and (H2O)14, has two distinct outcomes in the low temperature of interstellar space. One is to be barrierlessly transformed into HC2n+1N by capturing an H atom from water molecules near the water ice; the other is to be stabilized in the form of a C2n+1N ··· (H2O)n complex. This work may also represent the first study of water-catalyzed reactions associated with a molecular radical in space. The chemical behavior on water ice should have a prominent influence on the concentration of the polycyanoacetylene radicals C2n+1N (n ≥ 1), as well as their parents HC2n+1N, in space. Future experimental studies are highly desirable to probe such interesting processes.
Ultrathin Hydrated Dextran Films Grafted on Glass: Preparation and Characterization of Structural, Viscous, and Elastic Properties by Quantitative Microinterferometry

We report the deposition and partial of ultrathin dextran films on glass surfaces and the characterization of their structural, probes. The average distance between bead and surface was measured to an accuracy of ±0.2 nm by application of reflection interference contrast microscopy (RICM) and by application of an improved theory of image formation of this microinterferometric technique. The fluctuation of the height h(t) of the beads above the glass surface with time t was analyzed in terms of the theory of Brownian motion of particles in a potential V(h). The interaction potential V(h) of the bead was obtained by analyzing the height probability distribution of a bead in terms of the Boltzmann distribution law. It is shown that V(h) is determined essentially by the gravitational attraction and the polymer-induced disjoining pressure. The latter could be best interpreted in terms of a simple spring model, whereas the classical scaling theories of polymer-induced forces failed. An elastic constant of 300 N/m 2 was obtained. An apparent viscosity of the dextran film was determined by the evaluation of the damping constant of the height correlation function (h(t) h(o)). Applying the Brinkmann model of flow in porous media, the damping constant is further used to evaluate a hydrodynamic decay length of the hydrodynamic field in the dextran film.
Radio-frequency plasma in combination with aerosol injection for biomedical applications

Radiofrequency plasma for biomedical applications generated in coaxial geometry at atmospheric pressure was investigated. The plasma was characterized by key parameters, including gas temperature and electron density. It was shown that OH rotational temperature is in agreement with the temperature estimated by Rayleigh and Raman scattering techniques. RF plasma was combined with an aerosol injection for better control of the treated skin temperature and topical drugs delivery.
Coulomb-crystallised molecular ions in traps: methods, applications, prospects

Translationally cold, spatially localised molecular ions prepared by sympathetic cooling with laser-cooled atomic ions in ion traps have recently found a wide range of applications in both chemistry and physics. The very low temperatures of the ions (down to millikelvins), their tight localisation in the trap and the ability to control and manipulate single isolated molecules on the quantum level offer intriguing possibilities for new experiments in the realms of cold chemistry, precision molecular spectroscopy, mass spectrometry and quantum technology. The present article gives an overview of the basic experimental methods, current topics and recent developments in this field.
Analyse XPS des surfaces de Si et SiO2 exposées aux plasmas de CHF3 et CHF3—C2F6. Polymérisation et gravure

Si and SiO 2 surfaces exposed to 50 W, 200 mtorr CHF 3 and CHF 3 -C 2 F 6 RF plasmas (RIE mode) are characterized by X-ray Photoelectron Spectroscopy (XPS). A fluorocarbon overlayer containing CF x and C-CF x (x=1 to 3) species is observed; its thickness depends on the exposure time and the gas mixture. The substrate-overlayer interface is investigated. As the gas mixture evolves from pure C 2 F 6 to pure CHF 3 , the predominant phenomenon changes from etching to polymerization; modifications in the C 1s and the F 1s spectra are correlated to mass spectrometry measurements performed on the m/e=81 amu peak (C 2 F 3 + ). O 2 plasma stripping is successfully used to eliminate the overlayer, the influence of the O 2 flow rate on the stripping rate and the COF 2 partial pressure is studied Des surfaces de Si et SiO 2 exposees a des plasmas de CHF 3 et CHF3-C 2 F 6 sont caracterisees par spectroscopie de photoelectrons (XPS). Un depot fluorocarbone, d'epaisseur variable suivant la composition du gaz et le temps d'exposition, est observe a la surface des materiaux; les groupements CF 3 , CF 2 , CF, C-CF x X=1 a 3 sont mis en evidence. La composition et la structure du polymere sont discutees. L'interface polymere support est analysee en detail ainsi que le role des ions du plasma sur le mecanisme d'initiation du polymere. La competition entre les processus de gravure et de polymerisation est etudiee dans les melanges CHF 3 -C 2 F 6 . Une correlation est faite entre les resultats d'analyse de surface et ceux d'analyse du plasma par spectrometrie de masse. La gravure du polymere en plasma d'oxygene est enfin etudiee: la vitesse de gravure et la pression partielle du principal effluent de gravure COF 2 sont etudiees en fonction du debit; les surfaces nettoyees sont caracterisees
Polyacetylenverbindungen, 208 Acetylenverbindungen aus Osmitopsis asteriscoides (L.) Cass

Die sudafrikanische Composite Osmitopsis asteriscoides (L.) Cass. enthalt drei bisher noch nicht isolierte Acetylenverbindungen, deren Strukturen spektroskopisch ermittelt und durch Synthesen sichergestellt werden. Polyacetylenic Compounds, 208. Acetylenic Compounds from Osmitopsis asteriscoides (L.) Cass. The south african Composite Osmitopsis asteriscoides (L.) Cass. contains three previously not isolated acetylenic compounds, the structure of which being elucidated by spectral methods and confirmed by synthesis.
Modelling penetration of plant cuticles by crop protection agents and effects of adjuvants on their rates of penetration

A theory of cuticular penetration of crop protection agents (CPAs) is presented, which incorporates properties of cuticles and cuticular waxes as well as properties of active ingredients and adjuvants. Based on this theory, two models are developed which are analytical in the sense that they help to quantify and understand (i) differences in permeability among cuticles from different species, (ii) effects of properties of CPAs on permeabilities of cuticles and rates of uptake and (iii) the effects of adjuvants on properties of cuticles and rates of uptake of CPAs. The models can be used to predict rates of uptake of CPAs as affected by properties of cuticular waxes, active ingredients and adjuvants. However, before this can be done, a constant, two parameters and at least two variables must be estimated. Properties of cuticles are accounted for by the constant D0/Δx and the parameter β′. The former, the ratio of the mobility of a hypothetical molecule having zero molar volume (D0x) divided by the path length (Δx) across the cuticle, has the dimension of velocity (ms−1) and is independent of the solubility of the CPA. The latter is a measure of size selectivity of the cuticle. Differences in permeabilities of cuticles from different species increase with increasing size of active ingredients due to size selectivity (β′). Removing cuticular waxes from Citrus cuticles increased D0/Δx by a factor of 2042, while β was not affected. Differential solubility of CPAs is considered part of the driving force and at least two different partition coefficients are needed to account for differences in solubilities in cuticular waxes, cutin, water and the formulation residue on the surface of the cuticles. Adjuvants are solvents in the formulation residue on the leaf surface once the carriers (water and other volatile solvents) have evaporated and certain adjuvants also act as accelerators; they penetrate the cuticle and increase D0/Δx. Thus, accelerators increase rates of uptake and this effect depends on two factors, (i) the intrinsic activity of the accelerator and (ii) rate of penetration into the cuticle, because the active ingredients follow the accelerator front across the cuticle. Since accelerators penetrate from the formulation residue into the cuticle, the volume of the formulation residue decreases with time. This maintains high concentrations of CPAs in the formulation residue and, thus, maximum driving forces and rates of penetration. To utilise fully this dual accelerator effect, it is necessary to match velocities of penetration of accelerators and active ingredients accurately.
Fine-tuning of the Smc flux facilitates chromosome organization in B. subtilis

SMC complexes are widely conserved ATP-powered loop extrusion motors indispensable for the faithful segregation of chromosomes during cell division. How SMC complexes translocate along DNA for loop extrusion and what happens when two complexes meet on the same DNA molecule is largely unknown. Revealing the origins and the consequences of SMC encounters is crucial for understanding the folding process not only of bacterial, but also of eukaryotic chromosomes. Here, we uncover several factors that influence bacterial chromosome organization by modulating the probability of such clashes. These factors include the number, the strength and the distribution of Smc loading sites, the residence time on the chromosome, the translocation rate, and the cellular abundance of Smc complexes. By studying various mutants, we show that these parameters are fine-tuned to reduce the frequency of encounters between Smc complexes, presumably as a risk mitigation strategy. Mild perturbations hamper chromosome organization by causing Smc collisions, implying that the cellular capacity to resolve them is rather limited. Altogether, we identify mechanisms that help to avoid Smc collisions and their resolution by Smc traversal or other potentially risky molecular transactions.
SCREENING BACTERIAL AND RADICAL SCAVENGING PROPERTIES OF CHOSEN PLANT EXTRACTS USING THIN-LAYER CHROMATOGRAPHY–DIRECT BIOAUTOGRAPHY

Effect directed analysis method is proposed for searching compounds with antibacterial and radical scavenging properties in herbs. The method is based on thin-layer chromatography–direct bioautography of plant extracts and chemical screening using derivatization reagents. Bacillus subtilis and Escherichia coli were used as test bacteria for searching antibacterial properties of plant constituents and DPPH as a reagent for testing radical scavenging properties directly on earlier developed TLC plates. Anisaldehyde-sulfuric acid and natural product/polyethylene glycol 4000 reagent were used for derivatization of terpenoids and polyphenols, respectively.
Hamster PIWI proteins bind to piRNAs with stage-specific size variations during oocyte maturation

In animal gonads, transposable elements (TEs) are actively repressed to preserve genome integrity through the Piwi-interacting RNA (piRNA) pathway. In mice, piRNAs are most abundantly expressed in male germ cells, and form effector complexes with three distinct PIWI proteins. The depletion of individual Piwi genes causes male-specific sterility owing to severe defects in spermatogenesis with no discernible phenotype in female mice. Unlike mice, most other mammals have four PIWI genes, some of which are expressed in the ovary. Here, purification of PIWI complexes from oocytes of the golden hamster revealed that the size of the piRNAs loaded onto PIWIL1 changed during oocyte maturation. In contrast, PIWIL3, an ovary-specific PIWI in most mammals, associates with short piRNAs only in metaphase II oocytes, which coincides with intense phosphorylation of the protein. An improved high-quality genome assembly and annotation revealed that PIWIL1- and PIWIL3-associated piRNAs appear to share the 5′- ends of common piRNA precursors and are mostly derived from unannotated sequences with a diminished contribution from TE-derived sequences, most of which correspond to endogenous retroviruses (ERVs). Although binding sites for the transcription factor A-Myb are identified in the transcription start site regions of the testis piRNA clusters, the piRNA clusters in the ovary show no well-defined binding motifs in their upstream regions. These results show that hamster piRNA clusters are transcribed by different transcriptional factors in the ovary and testis, resulting in the generation of sex-specific piRNAs. Our findings show the complex and dynamic nature of biogenesis of piRNAs in hamster oocytes, and together with the new genome sequence generated, serve as the foundation for developing useful models to study the piRNA pathway in mammalian oocytes. Highlights - The size of PIWIL1-associated piRNAs changes during oocyte maturation - Phosphorylation of PIWIL3 in MII oocytes coincides with its association with small 19-nt piRNAs - Improved high-quality genome assembly and annotation identifies young endogenous retroviruses as major targets of piRNAs in hamster oocytes - PIWIL1- and PIWIL3-associated piRNAs share the 5′-ends of the common piRNA precursors in oocytes
The Use of Water Plants in Biomonitoring And Phytoremediation of Waters Polluted with Heavy Metals

Abstract The publication is a synthetic review of many years of research on the possibility of using water plants (macrophytes) to assess pollution of surface waters and the possibility of using the biomass in phytoremediation processes. The results of the research of kinetics and equilibria of heavy metals sorption and desorption conditions were presented in order to repeatedly use the biomass, as well as the research on the influence of abiotic factors on sorption processes. Defence mechanisms of macrophytes, which enable them to vegetate in considerably polluted waters, have been discussed. The results presented herein and carried out in many countries demonstrate that macrophytes can be successfully used in the biomonitoring of water environments and phytoremediation of waters and sewage; however, validation of these procedures requires more detailed research of the mechanisms, which accompany them. Abstrakt Publikacja jest syntetycznym przeglądem prowadzonych od wielu lat badań, dotyczących możliwości zastosowania roślin wodnych (makrofitów) do oceny zanieczyszczenia wód powierzchniowych oraz możliwości wykorzystania ich biomasy w procesach fitoremediacji. Przedstawiono wyniki badań dotyczących kinetyki i równowag sorpcji metali ciężkich, warunków desorpcji, w celu wielokrotnego wykorzystania biomasy, oraz badań dotyczących wpływu czynników abiotycznych na procesy sorpcji. Omówiono mechanizmy obronne makrofitów, umożliwiające im wegetację w wodach o znacznym zanieczyszczeniu. Zaprezentowane wyniki badań, prowadzonych w wielu krajach świata, wskazują, że makrofity mogą być w przyszłości z powodzeniem wykorzystywane w biomonitoringu środowiska wodnego oraz w fitoremediacji wód i ścieków, przy czym walidacja procedur wymaga dokładniejszego poznania mechanizmów, jakie towarzyszą tym procesom.
High switching endurance in TaOx memristive devices

We demonstrate over 1×1010 open-loop switching cycles from a simple memristive device stack of Pt/TaOx/Ta. We compare this system to a similar device stack based on titanium oxides to obtain insight into the solid-state thermodynamic and kinetic factors that influence endurance in metal-oxide memristors.
(2RS,5RS,6RS)-Ethyl 4-hydroxy-2,6-di-p-tolyl-5-p-tolylsulfanyl-1,2,5,6-tetrahydropyridine-3-carboxylate

The polysubstituted piperidine enol ring in the title compound, C29H31NO3S, adopts a twisted half-chair conformation. The crystal structure is stabilized by van der Waals and weak C—H⋯π inter­actions. An intra­molecular O—H⋯O inter­action generates an S(6) graph-set motif.
Extraction of astatine-211 in diisopropylether (DIPE)

Abstract The extraction mechanism of astatine-211 in diisopropylether (DIPE) is studied by analyzing the effect of the nature of the aqueous solution and organic solvent on the distribution coefficients characterizing the ratio of organic and aqueous concentration of astatine (D). On the one hand, at a given pH value, D was shown to be independant of the nature and concentration of the counter-ion present in the aqueous solution (Cl-, ClO4-, NO3-). On the other hand, the nature of the organic solvent had a strong effect. D increases as the polarity of the organic solvent increases. These experimental observations are explained by the solvation of astatine by the organic solvent. The back-extraction of astatine from the organic to the aqueous phase is efficient in basic conditions. This is explained by the formation of a hydrolyzed species of astatine presenting no affinity for DIPE. Hydrolysis constants of astatine are deduced from experimental data (logβ1=-3.0±0.1 and logβ2=-14.2±0.1).