Miracle-dz/UniFAR-FTUs huggingface dataset:
Energetics of intra- and intermolecular bonds in ω-alkanediols. III. Thermochemical study of 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol at 298.15 K

The enthalpies of combustion and sublimation or vaporization of the title compounds were determined on milligram samples and used to derive, at 298.15 K, the enthalpies of formation in the gaseous phase and the enthalpies of atomization. The previous conclusions drawn from the investigation of the lower ω-alkanediols were confirmed: the enthalpy of a hydrogen bond in solid ω-alkanediols amounts to 27 kJ mol−1 and the intramolecular C—C and C—OH bond enthalpies to 343.2 and 819.5 kJ mol−1, respectively. The enthalpies of fusion and the triple point temperatures of the ω-alkanediols are reported and discussed. Keywords: ω-alkanediols, enthalpies of formation, triple point temperatures, differential thermal analysis, calorimetry.
The behaviour of water under hydrostatic tension: II

A study is made of the behaviour of water under hydrostatic tension. A review of the literature reveals very considerable differences in the values of critical tension obtained by different methods, the factor of disagreement being sometimes as high as 50. Two methods are studied in detail: the Berthelot method, which makes use of the difference in expansions of glass and water and the Reynolds centrifugal method. Evidence is brought forward that it requires high pressures to persuade water to stick to glass under subsequent tension. A modification of the Berthelot method gives results in much better agreement with other methods. Examination of the Reynolds method shows that account must be taken of the fact that water does not move as a rigid body. Although this has no appreciable effect on the pressure distribution, it does imply a considerable stirring of the water, and any small bubbles would tend to be brought near the region of greatest tension in a time that might be comparable with that of the experiment. The flow of water in constricted tubes is also studied. The critical tension appears to be low, but this is to be expected in view of the fact that the motion is probably turbulent before cavitation occurs. It is concluded that if tension is applied statically, ordinary water can stand tensions of the order of 40 atmospheres, even if it is not perfectly air-free. Water nearly saturated with air has been shown to stand tension up to 6 atmospheres.
The effect of TMEDA on the kinetics of the anionic polymerization of methyl methacrylate in tetrahydrofuran using lithium as counterion

The kinetics of the anionic polymerization of methyl methacrylate in presence of N,N,N', -tetramethylethylenediamine (TMEDA) in THF are investigated using 1,1-diphenyl-hexyllithium as initiator in a temperature range between -20°C and 0°C in a flow-tube reactor. The rate constants of propagation determined in the presence of TMEDA are compared to those obtained in the absence of a chelating agent. For propagation, the reaction order with respect to active centers is found to be 0.5 in both cases which indicates that the chelation of the lithium cation does not effectively perturb the aggregation of the enolate ion pair. Both the rate constants of propagation via non-aggregated ion pairs, k ± , and the equilibrium constants of aggregation, K A , are not significantly affected by TMEDA. The rate constants of termination in absence and presence of TMEDA are also comparable. Thus, it is concluded that TMEDA is not a better ligand for lithium ester enolates than THF. Even the addition of a cyclic tertiary polyamine ("crown amine") such as 1,4,8,11-tetramethyltetraazacyclotetradecane, does not lead to a significant change in the propagation rate constant, however, no termination is observed at -20°C. Extrapolation of the observed rate constants at two temperatures gives estimates for the equilibrium constants of aggregation, K A , and the corresponding enthalpy and entropy. It is shown, that aggregation of PMMA-Li in THF is an endothermic, entropy-driven process (ΔH A ; ΔS A > 0), similar to the dimer-tetramer equilibrium of model ester enolates.
Conversion of Methane to Methanol on Diiron and Dicopper Enzyme Models of Methane Monooxygenase: A Theoretical Study on a Concerted Reaction Pathway

We present theoretical analyses for the conversion of methane to methanol on a diiron model of soluble methane monooxygenase (sMMO) and on dicopper models of particulate methane monooxygenase (pMMO) using the hybrid density-functional-theory B3LYP method. Methane is proposed to be reasonably converted into methanol in a two-step concerted manner on the dinuclear enzyme models. The first step in our proposal is concerted H atom abstraction of methane via a four-centered transition state (TS1) and the second step is concerted methyl migration via a three-centered transition state (TS2). The general features of the electronic process are identical to those of the gas-phase process for the methane-methanol conversion by the bare FeO+ complex. The concerted H atom abstraction and the direct H atom abstraction via a transition state with a linear C-H-O(Fe) array are compared using the dinuclear models. The transition state for the direct H atom abstraction (TSd) on the diiron model is found in the spin undecet .
Imobilização da lacase em micropartículas de quitosana obtidas por spray drying e usadas na construção de biossensores

Biosensors based on laccase immobilized on microparticles of chitosan crosslinked with tripolyphosphate (biosensor I) and glyoxal (biosensor II) obtained by spray drying for the determinations of rutin in pharmaceutical formulations were developed. Under optimized operational conditions (pH 4.0, frequency of 30 Hz, pulse amplitude of 40 mV and scan increment of 2.0 mV) two analytical curves were obtained for both biosensors showing a detection limit of 6.2x10-8 mol L-1 for biosensor (I) and 2.0x10-8 mol L-1 for biosensor (II). The recovery of rutin from pharmaceutical sample ranged from 90.7 to 105.0% and the lifetime of these biosensors were 4 months (at least 400 determinations).
Solvation Free Energies of Peptides: Comparison of Approximate Continuum Solvation Models with Accurate Solution of the Poisson−Boltzmann Equation

We have compared solvation free energies obtained from a number of approximate solvation models with an accurate solution of the Poisson−Boltzmann equation for a large data set of peptide structures, ranging from a single amino acid to a peptide sequence of length nine. The models are assessed for their ability to predict relative energetics of different peptide conformations (of the same sequence) as determined from the Poisson−Boltzmann results. We find that the widely used distance dependent dielectric model yields qualitatively erroneous results; in contrast, the generalized Born model of Still and co-workers, an approximation to the Poisson−Boltzmann equation, provides reasonably good solvation free energies and performs rather well in rank ordering of conformations. A surface area based model produces results of intermediate quality. Our results suggest that the generalized Born model is presently the clearly preferred alternative if one wishes to carry out molecular dynamics simulations with a fast.
Electrochemical determination of bisphenol A based on PHD/MWCNTs modified glassy carbon electrode

A novel electrochemical sensor for the determination of bisphenol A (BPA) was fabricated by block polyelectrolyte composite films, which composed of diblock polyelectrolyte poly (2-hydroxyethyl methacrylate)-b-poly (2-(dimethylamino) ethyl methacrylate) (PHEMA-b-PDMAEMA, noted as PHD in the later content) and multi-walled carbon nanotubes (MWCNTs). The tertiary amino groups of PDMAEMA can be protonated at physiological pH. The protonated PDMAEMA can thus interact with the negatively charged BPA through electrostatic attraction to increase the BPA sorption capacity and enhance the ability for highly sensitive detection of BPA. The PHD/MWCNTs composite films combine the electrocatalytic property of MWCNTs and the electrostatic attraction of protonated PHD. Because of the above-mentioned excellent property of the composite films, the PHD/MWCNTs/glassy carbon electrode exhibited good electrocatalytic activity to electrooxidation of BPA. The wide linear response range of the BPA sensor was from 4.56 × 10−5 g L−1 to 2.28 × 10−2 g L−1 with a lower detection limit of 2.28 × 10−6 g L−1 (S/N = 3) and high sensitivity 2442.86 μA L g−1 cm−2. The current reached the steady-state current with a shorter response time less than 4 s. The proposed method was successfully applied to determine BPA in real samples (PVC food package, milk, tap water and pond water) and satisfactory results were obtained. These results indicated that the block polyelectrolyte composite have potential applicability of the BPA sensor.
Isolation of spatulenol and (−)‐caryophyllene oxide from Vernonia mollissima don and 1H and 13C reassignment by two‐dimensional NMR spectroscopy

Two sesquiterpenoids, spatulenol and (−)‐caryophyllene oxide, were isolated from the hexane extract of the Brazilian plant Vernonia mollissima Don. The 1H and 13C NMR spectra of these compounds have been reassigned completely by COSY experiments and 13C/1H shift correlation diagrams.
Attempted prediction of the crystal structures of six monosaccharides

A method is reported to generate possible crystal structures of the six hexopyranoses where comparison with an X-ray determination is possible. In these molecules, internal degrees of freedom are all-important. Using essentially only the information that the space group is P2 1 2 1 2 1 with one molecule in the asymmetric unit, a systematic search was made for all low-energy crystal structures of these substances. The energies were minimized with respect to nine lattice and rigid-body parameters and six intramolecular dihedral angles. The number of possible structures within the range 10 kcal mol −1 is of the order 1000. In all cases, the experimental structure was among them, and in four cases this was either the structure with the lowest energy or only a few tenths of a kcal mol −1 higher. However, in the two other cases the relative energy of the experimental structure was over 5 kcal mol −1 . Such calculations can provide a sensitive test for force fields
Observation of carbon-containing nanostructured mixed titania phases for visible-light photocatalysts

This research analyzed a visible-light-responsive carbon-containing titania photocatalysts prepared by sol-gel method using confocal Raman spectral mapping, transmission electron microscopy, and UV/visible spectroscopy. The incorporation of carbons in the initial titania powder of anatase and amorphous phases was found to facilitate the formation of rutile or brookite phases from the amorphous phase in the 150–250°C temperature range, resulting in nanostructured mixed titania phases which create interface states and effectively shift the band gap to ∼2.7eV. The further shift in the absorption tails up to 800nm was attributed to carbon species-covered and/or defected titania powders.
Fabrication of Artificial Petal Sculptures by Replication of Sub‐micron Surface Wrinkles

In this contribution, we discuss wrinkling as a process resulting in well-defined periodic micron-sized structures, as known from the interface of several plant cells. We show possible pathways to transfer this principle to artificial materials such as epoxy resins or polymers. While topographical structuring of surfaces by wrinkling is meanwhile well established for elastomers like poly (dimethyl siloxane), so far the step towards other classes of materials has not been taken. This puts several limitations to potential applications of artificial wrinkled structures, as elastomers show poor dimensional stability, low optical quality, and tend to swell in organic solvents. As well, artificial structures formed by wrinkling are not tension-free on the microscopic level, which makes them metastable. Residual mechanical tensions can affect dimensional stability on long timescales. We introduce two processes, micro thermoforming and molding, as means to overcome these restrictions and to pattern non-elastomeric materials by using wrinkled elastomers as templates. The two approaches allow the formation of negative and positive replicas and allow the transfer of sub-micron features with high fidelity.
Voltammetric Behavior of Sunscreen Agents at Mercury Film Electrode

The voltammetric behavior of sunscreen agents on glassy carbon and mercury film electrodes was investigated in aqueous media containing various supporting electrolytes. The possible reaction mechanisms were discussed by the relations of pH values and peak potentials and currents. 2-Ethylhexylsalicylate, 2-ethylhexyl-4-methoxycinnamate and 2-hydroxy-4-methoxy benzophenone can be separated at the thin-film mercury deposited glassy carbon electrode in 0.1 M tetrabutylammonium hydroxide. The peak potentials were −1.988 V, −1.610 V and −1.464 V for 2-ethylhexylsalicylate, 2-ethylhexyl-4-methoxycinnamate and 2-hydroxy-4-methoxy benzophenone, respectively. The electroreduction process is applied for the simultaneous quantitative determination of sunscreen agents in cosmetics. Comparison with results obtained from high-performance liquid chromatography shows good agreement.
Ageing promotes early T follicular helper cell differentiation by modulating expression of RBPJ

Ageing profoundly changes our immune system and is thought to be a driving factor in the morbidity and mortality associated with infectious disease in older people. We have previously shown that the impaired immunity to vaccination that occurs in aged individuals is partly attributed to the effect of age on T follicular helper (Tfh) cell formation. In this study, we examined how age intrinsically affects Tfh cell formation in both mice and humans. We show increased formation of Tfh precursors (pre‐Tfh) but no associated increase in germinal centre (GC)‐Tfh cells in aged mice, suggesting age‐driven promotion of only early Tfh cell differentiation. Mechanistically, we show that ageing alters TCR signalling which drives expression of the Notch‐associated transcription factor, RBPJ. Genetic or chemical modulation of RBPJ or Notch rescues this age‐associated early Tfh cell differentiation, and increased intrinsic Notch activity recapitulates this phenomenon in younger mice. Our data offer mechanistic insight into the age‐induced changes in T‐cell activation that affects the differentiation and ultimately the function of effector T cells.
COVID-19: Can early home treatment with Azithromycin alone or with Zinc help prevent hospitalisation, death, and long-COVID-19? A review

Introduction The effects of the SARS-CoV-2 pandemic continues to disrupt health systems worldwide, leading to population lockdowns in many countries. Preventing hospitalisation, death and long-COVID-19 with repurposed drugs remains a priority. Hydroxychloroquine (HCQ) and azithromycin (AZM) are the most commonly used in ambulatory care, with divergent results. With the aim of decentralizing early treatment to family practitioners, we addressed the question: Can early home treatment with AZM alone or with zinc help prevent hospitalisation, death, and long-COVID-19? Methodology We conducted a scoping review of articles published from 31st December 2019 to 5th November 2020 in Pubmed, Google Scholar, MedRxiv, and BioRxiv databases, and a review of undergoing clinical trials published in the Clinicaltrial.gov database. Results Many studies report on outpatient treatment with a combination of AZM + HCQ versus AZM alone, and few studies propose the addition of Zinc (Zn) to AZM. In addition, we identified 5 clinical trials currently recruiting individuals for early outpatient treatment with AZM. However, we failed in identifying any study or clinical trial conducted with family practitioners responding to our question. Discussion The antiviral, anti-inflammatory, immunomodulatory benefits of AZM + Zn make this drugs combination a good candidate therapy to treat flu-like-COVID-19 and atypical pneumoniae. The antibacterial action of AZM can also help disrupting the bacteria/virus cooperation that is poorly documented. Considering pros and cons of macrolide use (including antimicrobial resistance), we call for early use of this therapy by family practitioners for home treatment of individuals presenting mild or moderate symptoms under rigorous scientific guidance to prevent hospitalisation, death and long-COVID.
Degree, quaternions and periodic solutions

The paper computes the Brouwer degree of some classes of homogeneous polynomials defined on quaternions and applies the results, together with a continuation theorem of coincidence degree theory, to the existence and multiplicity of periodic solutions of a class of systems of quaternionic valued ordinary differential equations. This article is part of the theme issue ‘Topological degree and fixed point theories in differential and difference equations’.
Leucophosphite K[Fe2(PO4)2(OH)(H2O)]·H2O: Hydrogen Bonding and Structural Relationships☆

Hydrogen atom positions in leucophosphite K[Fe 2 (PO 4 ) 2 (OH)(H 2 O)] . H 2 O were elucidated by Rietveld refinement of a powder neutron scattering diffractogram. Crystal data: a = 975.6(3), b = 966.4(3), c = 976.9(4) pm, β = 102.43(2)°, R wp = 0.084. This experiment proved that the Fe-atoms in the tetrameric Fe 4 O 2 building units of leucophosphite are bridged by hydroxo groups and that the phosphate tetrahedra are not protonated. While the water molecule O(10) bound to Fe acts only as a H-bond donor, the second water molecule O(11) between the tetrameric units donates and accepts H-bonds. Together with oxygen atoms from phosphate groups a six-membered ring of oxygen atoms, connected by hydrogen bonds, is formed. Water O(11) is held in the structure by comparably weak H-bonds so that it is already lost at 396(3) K. Fe 4 O 2 tetramers topological analogous to those in leucophosphite are found in the minerals spheniscidite, melonjosephite, and amarantite, and in a number of synthetic iron complexes. The structural relationships of leucophosphite with compounds containing M 4 O 2 clusters (M = Al, Ga, Mo) are discussed.
A Code of Practice for Discontinuous Corrosion Testing in High Temperature Gaseous Atmospheres

Un projet (TESTCORR) finance par la Commission Europeenne est en cours de realisation pour etablir un Code Pratique pour les mesures discontinues de corrosion a haute temperature en atmospheres gazeuses avec et sans depots sur la surface du metal. Le Code comprendra des experiences de reference qui pourront etre utilisees comme conditions d'essais standards. Celles-ci seront validees en effectuant une ou plusieurs experiences de reference et en en comparant les resultats avec ceux decrits dans le Code Pratique. Ces resultats seront obtenus a partir d'une etude intercomparative formant partie du projet, precedee d'un test de competence des participants. Deux documents, brouillons du Code Pratique, seront mis en circulation, et il y aura une participation externe, en plus de celle des partenaires pour la conduite des tests de competence et de l'etude comparative.
Autoimmunity to the Lung Protective Phospholipid-Binding Protein Annexin A2 Predicts Mortality Among Hospitalized COVID-19 Patients

Background: Annexin A2 is a phospholipid-binding protein involved in fibrinolysis, cell membrane stabilization and repair, and ensuring the integrity of the pulmonary microvasculature. Given the autoantibodies observed in COVID-19 and that Annexin A2 is a known target of antiphospholipid antibodies, we studied autoimmunity directed against Annexin A2 among hospitalized COVID-19 patients. Methods: We used ELISA to identify the levels of IgG autoantibodies recognizing Annexin A2 and A5 among 86 hospitalized cases of COVID-19. Using logistic regression, we analyzed the association between anti-Annexin A2 and A5 antibody levels with mortality after adjusting for age, sex, race and key comorbidities. Results: We found higher average levels of anti-Annexin A2 antibodies among hospitalized COVID-19 patients that died when compared with non-critical hospitalized COVID-19 patients (p-value = 0.006) and critically ill COVID-19 patients (p-value = 0.04). No significant differences in anti-Annexin A5 antibody levels were identified. Regression analysis showed that anti-Annexin A2 antibody levels as measured in relative units strongly predicted mortality with an odds ratio of 9.3 (95% CI: 1.9 to 44.6, p=0.005). In contrast, anti-Annexin A5 antibody levels were not associated with higher mortality (95% CI: 0.5 to 15.2, p=0.22). Conclusions: We determined that anti-Annexin A2 antibodies were elevated among hospitalized COVID-19 patients and these levels predicted mortality. It is known that inhibition of Annexin A2 induces systemic thrombosis, cell death, and non-cardiogenic pulmonary edema. Autoimmunity to Annexin A2 is a potential mechanism that may explain the key clinical findings of severe COVID-19.
How Do Partisans Consume News on Social Media? A Comparison of Self-Reports With Digital Trace Measures Among Twitter Users

There are growing concerns that social media exacerbates the selective exposure of audience members to content that supports their political views. However, despite the hype, the existing literature does not fully address the extent to which social media users selectively consume like-minded news stories, in part due to different methodologies. In an attempt to move toward a common framework, this study examined the partisan selective exposure of a representative sample of Twitter users by combining survey data with digital trace data. Specifically, the study linked survey responses (n = 558) from Twitter users with their media following and exposure to news via their friends. The study found that selectivity bias was present in all types of data, including self-reported media consumption (survey), media following (Twitter), and indirect exposure to media (Twitter). However, the study found some differences between self-reports and digital measures such that the overlaps in media diets between partisan groups were much larger based on the digital trace data than the self-reported data. In addition, the study observed an asymmetric pattern of selective exposure between conservatives and liberals in the digital trace data, but not in the self-reported data. The implications of these findings are discussed with reference to the contemporary news environment, hostile media effects, and normative assumptions of selective exposure.
Atomic hydrogen densities in capacitively coupled very high-frequency plasmas in H2: Effect of excitation frequency

Absolute hydrogen atom densities in pure hydrogen capacitive discharges were measured as a function of excitation frequency (13.56, 27.12, and 40.68 MHz), nominal electrical power, and gas pressure (between 0.1 and 1 Torr). Quantitative measurements were made using two-photon absorption laser-induced fluorescence (TALIF), put on an absolute scale by comparison with the TALIF signal from a known density of krypton gas, as proposed by Niemi, Schultz von Gathen, and Dobele [J. Phys. D 34, 2330 (2001)]. The H atom density increases with gas pressure and electrical power, and at a given power and pressure it increases significantly with excitation frequency. The latter can be attributed in part to increased electron density. However, time-resolved TALIF measurements in the afterglow showed that the H atom surface loss probabilities are not constant, becoming somewhat smaller when the sheath voltage is lowered, as is the case when the excitation frequency is increased, contributing to the increase in H density.