Miracle-dz/UniFAR-FTUs huggingface dataset:
Including Side Chain Flexibility in Continuum Electrostatic Calculations of Protein Titration

We have extended Monte Carlo procedures for computing statistical averages over protonation states of a protein to include conformational states of the titrating amino acid side chains. This computational method couples side chain motion and protonation with changes in solution pH. Using a continuum electrostatic model for protein titration, we applied this sampling method to calculate titration curves for lysozyme, myoglobin, and hemoglobin. In addition to the X-ray conformation, each titrating site was allowed to reorient to a conformation with maximum solvent accessibility. For all proteins considered, inclusion of these additional conformations improved agreement with experimental measurements for both overall titration and individual pKas. The results suggest that well-solvated orientations of amino acid side chains are an important factor in determining proton binding characteristics of proteins.
Structural and thermal parameters for rutile and anatase

Neutron powder diffraction patterns from rutile (TiO2, P42/mnm, a = 4.594, c = 2.959/k) and anatase (TiO2, I41/amd, a= 3-785, c=9-514/k) have been analysed by the Rietveld method. The positional parameters were determined to be x o = Y o = 0.30478 (6) in rutile and Zo = 0.20806 (5) in anatase. The anisotropic thermal parameters were also determined. The results from this constant-wavelength neutron diffraction study are in remarkably good agreement with the results from a recently published analysis of time-of-flight neutron data from the same phases. A comparison is made with results from earlier X-ray single-crystal investigations of these polymorphs of titania, and again the agreement is good. In particular, there is no evidence for any significant difference between X-ray and neutron determinations of the oxygen position such as might have resulted from polarization effects. The thermal vibrations show marked anisotropy, which appears to be determined by the stereochemistry of the crystal structure. The Debye temperatures esti* Present address: Bristows Cooke and Carpmael, 10 Lincoln's Inn Fields, London WC2A 3BP, England. 0108-7681/91/040462-07503.00 mated from the diffraction data are 600 (10)K for rutile and 520(10)K for anatase at room temperature.
General characteristics of thermally cycled tin oxide gas sensors

The response, measured as conductance, of thermally cycled tin oxide gas sensors was studied to determine the potential inherent in this technique with respect to increased selectivity and sensitivity. It was found that the range of cycle temperature as well as the period of the cycle had a critical effect on the amount of information that could be extracted from the conductance versus time curves. Significantly different conductance curve shapes were seen for such gases as propane, carbon monoxide and ethanol when an offset sinusoidal waveform was used to drive the sensor heater. The effect of varying the concentration of the reducing gas was examined both to check the effect on selectivity between gases and to determine the functional relationship between conductance and gas concentration as related to the time in the cycle period. It was found that the conductance change at the low-temperature section of the thermal cycle can vary at a rate faster than linear for low concentrations, and because the clear air conductance is very low in these sections the thermally cycled sensor is extremely sensitive to reducing gas.
First evidence of multiple octahedral Al sites in Na-montmorillonite by 27Al multiple quantum MAS NMR

The configuration of hydroxyl groups around the octahedral cations of 2:1 phyllosilicate minerals has long been an important question in clay science. In the present study, 27Al multiple quantum (MQ) magic angle spinning nuclear magnetic resonance (MAS NMR) was applied to the local structural analysis of octahedral Al positions in a purified Na-montmorillonite. Three octahedral Al sites ([6]Ala, [6]Alb, and [6]Alc) are distinguished by 27Al 5QMAS NMR, whereas these sites are not differentiated by 27Al MAS and 3QMAS NMR. The isotropic chemical shift (δcs) and the quadrupolar product (PQ) were estimated to be 5.8 ppm and 2.6 MHz for [6]Ala, 6.2 ppm and 3.0 MHz for [6]Alb, and 6.7 ppm and 3.7 MHz for [6]Alc, respectively. The three Al sites originated from geometric isomers with cis and trans structures, which have mutually different configurations of the OH groups around the central Al3+ ions. From the view point of symmetry for the OH groups, [6]Ala and [6]Alb in the upfield region were assigned to cis sites, and [6]Alc in the downfield region was assigned to a trans site. The occurrence of multiple Al sites implies that Na-montmorillonite used in the present study has cis-vacant structure in the octahedral sheet. This is a reasonable insight, supported by the chemical composition and the differential thermal analysis data of the Na-montmorillonite.
Preparation and properties of hydrophobic poly(vinylidene fluoride)–SiO2 mixed matrix membranes for dissolved oxygen removal from water

The application of the membrane method for removing dissolved oxygen (DO) from water on the laboratory scale was studied. Flat mixed matrix membranes were composed of poly(vinylidene fluoride) (PVDF) and hydrophobic nanosilica particles, which were used to improve the DO removal process. The SiO2 particles were modified by a silane coupling agent and examined by Fourier transform infrared spectroscopy. It was shown that the surface of the SiO2 particles was bonded to hydrophobic long-chain alkane groups through chemical bonding. The effects of adding SiO2 particles on the membrane properties and morphology were examined. The results show that the porosity and pore size of the membrane were affected by the introduction of SiO2 particles, and the cross-sectional morphology of the PVDF composite membranes changed from fingerlike macrovoids to a spongelike structure. The membrane performance of DO removal was evaluated through the membrane unit by a vacuum degassing process. It was found that the SiO2/PVDF hybrid membranes effectively improved the oxygen removal efficiency compared with the original PVDF membranes. The maximum permeation flux was obtained when the loading amount was 2.5 wt %. The effect of the downstream vacuum level was also investigated. The experimental results show that the SiO2/PVDF hybrid membranes had superior performances and could be an alternative membrane for removing DO from water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40430.
Delignification mechanism during high-boiling solvent pulping. Part 6: Changes in lignin structure analyzed by 1H-13C correlation 2-D NMR spectroscopy

Abstract In order to investigate the delignification mechanism during high-boiling solvent (HBS) pulping, softwood HBS lignin samples from todo fir (Abies sachalinensis) were analyzed by 1H–13C correlation NMR spectroscopy (HMQC). Nine lignin model compounds that may represent the substructures in HBS lignin were prepared. The 1H and 13C NMR spectral data were compared with HBS lignin samples. The HMQC spectra of HBS lignin samples showed the disappearance of β-O-4 structures. Introduction of a pulping solvent into lignin was plainly observed with new signals in aliphatic regions. Only the erythro β-1 structure was detected in softwood milled wood lignin from todo fir by HMQC spectra. The β-1 structure was very reactive and probably produced the stilbene structure. The β-β and β-5 structures remained in HBS lignin. The 4-O-5 structure was successfully detected by HMQC spectra, and it was found to be stable under the conditions used.
Formation of monodispersed nano- and micro-particles controlled in size, shape, and internal structure

Size control of monodispersed particles must normally be performed during the very short nucleation period, because the final particle number is determined by the end of the nucleation and it does not change until the end of the particle growth. On the other hand, the shape control is mainly performed by adsorption of shape controllers during the growth period, although in some cases the crystal structure of the nuclei may have essential influence on the morphology of the grown particles. The internal structure of each particle is often strongly affected by the action of shape controllers. This article deals with the fundamental mechanisms of the nucleation, growth, and structural formation of monodispersed nano- and micro-particles, leading to the control of their size, shape, and internal structure.
Fabrication of ZnO nanorods and nanotubes in aqueous solutions

A novel aqueous solution method has been developed for growing well-aligned crystalline ZnO nanorods (NRs) and nanotubes (NTs) on a variety of substrates including Si wafers, poly(ethylene terephthalate) (PET), and sapphire. Atomic layer deposition (ALD) was first used to grow a uniform ZnO film on the substrate of choice and to serve as templating seed layer for the subsequent growth of NRs and NTs. On this ZnO layer highly oriented two-dimensional NR arrays of ZnO were obtained by solution growth process using zinc nitrate and hexamethylenetetramine in aqueous solution. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the ZnO NRs. The diameter of ZnO NRs obtained varies according to the concentration of reactants, reaction temperature, and solution pH. The length of the ZnO NRs is controlled by growth time as well as by the concentration of reagents in the aqueous solution. ZnO NTs with diameters of 40−60 nm were found to self-assemble on the top faces of ZnO NRs. High-resolution tra.
Significado y uso de los emojis de WhatsApp dentro de situaciones comunicativas interculturales

Las tecnologías de la globalización buscan utilizar códigos más universales para facilitar la interacción entre todos. Se estudiarán los emojis en WhatsApp, en cuanto estos se convierten en herramientas determinantes durante situaciones comunicativas interculturales. Bajo esta pauta, se analizarán sus contextos de uso, sus significados y también su rol en cuanto a la expresión de las identidades culturales. La hipótesis de esta investigación plantea que estas interacciones interculturales llevarán, a largo plazo, a un consenso en la significación de algunos de estos íconos. En este estudio se realizaron entrevistas a personas de distintos países (Inglaterra, España, Suiza, India, Estados Unidos y Japón) sobre las circunstancias en las que usan los emojis de su sección “emojis más frecuentes” en WhatsApp. Así se pudo comparar los significados y el uso. En consecuencia, a pesar de las brechas culturales, existen ciertos emojis que son comprendidos por todos; es decir, han adquirido un significado universal. Estos son los emojis referidos a expresiones faciales. Sin embargo, el estudio también reveló que existen ciertos emoticonos cuyo significado varía parcial o totalmente entre culturas, esto debido al nivel de dependencia de estos a factores culturales y contextuales, además de las condiciones mismas de la persona que los utiliza, así como del receptor del mensaje.
Organochlorine Pesticide Residues in Sardinella Aurita from the Coastal Waters of Accra-Tema, Ghana and their Potential Health Risks

Sardinella aurita and seawater samples from the Accra-Tema coast of Ghana were analysed for organochlorine (OC) pesticides using gas chromatography (GC) with electron capture detection (ECD). Residues of DDTs (p,p�-DDT, p,p�-DDE, p,p�-DDD), hexachlorocyclohexane (HCHs - �-HCH, �-HCH and �-HCH), endosulfan (�-endosulfan, �-endosulfan, endosulfan sulphate) and heptachlor were detected in fish at average concentrations ranging from 3.0 to 1235.0 �g/kg wet wt. These residues were, however, below the detection limit in seawater samples. Significant differences (p < 0.05) in residue levels were also observed across sites, decreasing from Chorkor to Kpone for seven (7) of the residues that were detected in S. aurita. Evaluation of hazard ratios (HRs) and the health risk associated with OC exposure from consumption of sardinellas re-vealed a probability of adverse health effect due to p,p�-DDT, �-HCH and heptachlor. Hence, p,p�-DDT, �-HCH and heptachlor may be of particular health concern.
High-Frequency Impedance Spectroscopy of Platinum Ultramicroelectrodes in Flowing Solutions

A method for studying impedance spectroscopy of micrometer-sized electrodes in the frequency range from 5 kHz to 5 MHz has been developed and tested. Details of the electronic circuit and the data processing method are provided. Since the method involves high-speed data acquisition and fast Fourier transformation, the impedance data can be obtained within a 5-ms time window. This enables measurement of changes in the electrode impedance caused by rapid changes in the solution composition. In particular, the method is well suited to studying the performance of electrochemical microdetectors in flowing solutions. The performance of the method was tested in a brief study of the competitive adsorption of hydrogen and methionine on a Pt ultramicroelectrode. It has been shown that proper electrochemical conditioning can prevent any long-term changes in the properties of the electrode caused by its exposure to common organic or inorganic substances. Hence, it provides means for making an ultramicroelectrode with.
Mechanistic study of macrophage activation by LPS stimulation using fluorescence imaging techinques

Lipopolysaccharide (LPS), a structural component of the outer membrane of gram negative bacteria, has been suggested that stimulates macrophages secrete a wide variety of inflammatory mediators, such as nitric oxide (NO). However, the cellular mechanisms of NO generation in macrophage by LPS stimulation are not well known. In this study, LPS stimulated NO generation in macrophage was determined by measuring fluorescence changes with a NO specific probe DAF-FM DA. Using the fluorescence resonance energy transfer (FRET) techniques, we found an increase of protein kinase C (PKC) activation was dynamically monitored in macrophages treated with LPS. Nuclear factor kappa B (NF-κB) translocated from the cytoplasm to the nucleus in macrophage was measured by confocal laser scanning microscopy. Moreover, the PKC inhibitor GÖ6983 inhibited LPS-stimulated NF-κB activation and NO production. These results indicated that LPS stimulated NF-κB mediated NO production by activating PKC.
Behaviour of Phenoxyacetic Acids During Underground Passage with Different Redox Zones

The behaviour of the three phenoxyacetic acid herbicides 2,4-D, 2,4,5-T and MCPA during underground passage and bankfiltration was tested in a model system consisting of laboratory filter columns filled with natural underground materials. Different redox environments were reproduced by operating the filters with natural aerobic and anaerobic groundwater. In the presence of oxygen, biodegradation of the three herbicides started after a lag phase. Under sulfate reducing conditions, no degradation could be observed. To assess the factors that may influence microbial degradation in the anaerobic environment, the concentration of herbicides, the time and the nutrient content were varied, but this did not increase degradation. The maximum retention of the herbicides in the filters was 30%, mainly due to adsorption to the filter material.
The Effect of Using Self-Regulated Learning Strategies on Developing English Language Critical Reading Skills of Governmental Language Secondary Stage Students

administering a critical reading skills test which included items measuring how much students acquired these skills. The data were analyzed statistically through the use of Cronbach's Alpha, t-test for paired samples, internal consistent validity and effect size (ES). The results of the students' critical reading skills test were fairly high. This revealed that the implemented self-regulated learning strategies had a significantly positive effect on developing the critical reading skills in English for secondary school students.
Computer simulation of the hydrophobic hydration of concave surfaces

Hemispherical objects of radius from 6.5 to 12.2 Å were constructed from tessellated icosahedra where the vertices were hydrophobic ‘atoms’. These hemispheres were hydrated in a periodic box of water and molecular dynamics simulations in the NVE ensemble were performed on this solution at 320K. Results show that water molecules in the concave region exhibit a layered structure and have their dipoles preferentially oriented approximately orthogonal to the radial direction of the hemisphere. They possess fewer hydrogen bonds and near neighbours. Changes in the translational dynamics of these water molecules are not detected, but there is an acceleration of the re-orientational dynamics. This work thus represents the first systematic study of the hydration of concave hydrophobic surfaces.
Features of Li-Mn-MgO Catalysts and Their Relevance in the Oxidative Coupling of Methane

This work describes relevant structural features of the ternary Li-Mn-MgO system useful for the reaction of methane oxidative coupling. For a Mn-MgO catalyst, XRD, XPS, and ESR techniques revealed that manganese is incorporated into a Mg[sub 6]MnO[sub 8] phase in which the formal oxidation state of manganese is Mn[sup 4+]. Addition of Li[sub 2]CO[sub 3] in small amounts (0.48-1.60 wt.% Li) to the base Mn-MgO catalyst results in partial destruction of the Mg[sub 6]MnO[sub 8] phase. TPR and XPS data showed that the reduction of manganese is easier in the bulk Mg[sub 6]MnO[sub 8] compound than in the Mn-MgO catalyst and that it is inhibited by lithium. Moreover, the increase in Mn/Mg XPS intensity ratios in the lithium-doped counterparts indicates that lithium incorporation into the base Mn-MgO catalyst enhances manganese dispersion, in agreement with the increase of Mn[sup 4+]-Mn[sup 4+] distance derived from ESR spectra. 37 refs., 6 figs., 4 tabs.
Measurement of deuterium incorporation into fatty acids by gas chromatography/isotope ratio mass spectrometry

A continuous-flow pyrolysis interface for gas chromatography/isotope ratio mass spectrometry (GC/IRMS) has been developed for δ2H analysis of individual organic compounds. Pyrolysis of gas chromatographically separated fatty acid methyl esters is performed at 1200 °C in an unpacked alumina tube to convert nanomole quantities of individual compounds to H2. Hydrogen is separated from other gaseous pyrolysis products on a solid-phase capillary column prior to its entering the mass spectrometer. Use of an isotope ratio mass spectrometer with high mass dispersion ensures 2H1H:1H1H ratio measurement is accurately made in the presence of a large excess of helium carrier gas. The technique has been applied to the measurement of lipid synthesis in humans, using deuterium oxide (D2O) incorporation into fatty acids. Using safe body water deuterium enrichments (<0.5%) the labelled fatty acids are unlikely to contain more than one deuterium per molecule, and show similar chromatographic behaviour to natural abundance samples. Following overnight incorporation of D2O, plateau palmitate enrichments were measured by GC/IRMS with a relative standard deviation (RSD) of ∼0.5%. This compares favourably with GC/MS measurements for which an RSD of 5 to 10% would be expected for similar samples. Compared to off-line sample conversion and IRMS, the current approach is much less laborious and gives information on individual fatty acids rather than the mixed triacylglycerols. Copyright © 1999 John Wiley & Sons, Ltd.
Ring-Opening Polymerization of ε-Caprolactone by Poly(ethylene glycol) by an Activated Monomer Mechanism†

Summary: The polymerization of e-caprolactone (CL) in the presence of HCl · Et2O by an activated monomer mechanism was performed to synthesize diblock or triblock copolymers composed of poly(ethylene glycol) (PEG) and poly(e-caprolactone) (PCL). The obtained PCLs had molecular weights close to the theoretical values calculated from the CL to PEG molar ratios and exibited monomodal GPC curves. We successfully prepared PEG and PCL block copolymers by a metal-free method. The non-metal catalyzed living ring-opening polymerisation of e-caprolactone by PEG.
In Situ IR Observation of Surface Species during the Photocatalytic Decomposition of Acetic Acid over TiO2 Films

Surface-enhanced IR absorption spectroscopy (SEIRAS) was applied to in-situ observation of the adsorption states and the photocatalytic decomposition of acetic acid on Au/TiO2 and Au/Pt/TiO2 films. The adsorption states of acetic acid were determined in both the liquid and gas phase, and molecular adsorption was found to be dominant in the gas phase. Pt deposition on the TiO2 film led to the formation of adsorbed methyl during the photodecomposition of gas-phase acetic acid, indicative of the formation of methyl radical as a reaction intermediate. The addition of gas-phase water to the system led to a significant increase in the coverage of adsorbed methyl as a result of enhancement in the reaction rate as reported before.
Heights and widths of Umweganregung profiles in comparison with Bragg reflection profiles

The excellent agreement between experimental Umweganregung patterns and those calculated with UMWEG90 [Rossmanith (1992). Acta Cryst. A48, 596–610] has been demonstrated by Rossmanith, Adiwidjaja, Eck, Kumpat & Ulrich [J. Appl. Cryst. (1994), 27, 510–516]. It has also been shown that, by fitting calculated to experimental ψ scans, consistent and physically significant parameters for the mosaic structure parameters of the sample – mosaic spread and mosaic block size – and for the divergence parameter of the X-ray beam can be obtained. In this paper, it is shown that, furthermore, the relative intensities of ψ scans of different forbidden reflections of a particular sample are predicted satisfactorily with UMWEG90 using the parameters obtained in the previously mentioned paper. To make an appraisal of the possible maximum gain due to Umweganregung, ω–2θ–ψ scans of 14 forbidden reflections of a particular zinc sample were analysed. By comparison of the ω–2θ intensity profiles and integrated intensities of the multiple diffraction events with those of the rocking curves of 15 Bragg reflections with neighbouring Bragg angles, the statements given in standard textbooks, that the profiles of Umweganregung events are much sharper and the intensities much smaller than those of possible Bragg reflections, are disproved.
The effects of stoichiometry and structure on the dynamic torsional properties of a cured epoxy resin system

Abstract The dynamic torsional characteristics of a difunctional, bisphenol-A-type epoxy resin cured with different amounts of metaphenylene diamine, using two cure cycles, were determined in torsion at four frequencies between −150° and 200°C. Besides two prominent relaxations, α and β, a third broad, but not very intense, relaxation has been shown to be present in all samples in the intermediate temperature range and has been designated the α transition. An analysis of the data on the temperature and frequency dependence of these relaxations allows some insight into their possible molecular origins. The torsional moduli were found to be related to the molecular packing, as reflected in their densities.