Miracle-dz/UniFAR-FTUs huggingface dataset:
Recrystallization and ice‐crystal growth in a biological specimen, as shown by a simple freeze substitution method

The sensory hairs of the silkmoth, Bombyx mori, are suitable test objects to check for recrystallization and secondary freezing damage in a biological object, because cryofixation by immersion into propane (90 K) routinely yields well‐preserved specimens without noticeable freezing damage. After rewarming the frozen specimens for 10 min to 230 K (boiling propane), the tissue preservation has not deteriorated, and even after 45 min at 230 K, ice‐crystal ghosts rarely exceed 50 nm. Two minutes at 250 K (in deep freezer) produced moderate freezing damage with ice‐crystal ghosts of 30–75 nm, whereas 90 min at 250 K resulted in severe damage with ice‐crystal ghosts well over 100 nm. Secondary freezing damage by ice‐crystal growth upon rewarming well‐frozen biological specimens, therefore, is a relatively slow process, depending not only on the temperature, but also on the exposure time. Moreover, with some biological specimens, secondary ice‐crystal growth starts at much higher temperatures than previously guessed, and with short exposure times rarely should become a hazard in fine structure work.
Antibiotic Metabolites from the Coral-Associated Actinomycete Streptomyces sp. OUCMDZ-1703

From the oligotrophic culture of a soft coral-associated actinomycetes strain, Streptomyces sp. OUCMDZ-1703, we isolated and identified two new chlorinated polyketides that we named strepchloritides A and B (1 and 2), three thiazole derivatives known as watasemycin A (3), pulicatin G (4) and aerugine (5), along with pyrrole- 2-carboxamide, furan-2-carboxamide and 1-(3,5-dihydroxyphenyl)ethanone. The new structures of 1 and 2 were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses, while the known compounds were identified by comparison of the NMR data with those in literatures. The results showed that actinomycete strain OUCMDZ-1703 could use the relative high ratio of chlorine in the oligotrophic medium to synthesize chlorinated natural products. New compounds 1 and 2 displayed cytotoxicity against the MCF-7 cells with IC50 values of 9.9 and 20.2 μmolL -1 , respectively. Thiazole derivatives 3 and 5 were first found to be active against three clinical strains of methicillin-resistant Staphylococcus aureus (MRSA082, MRSA111 and MRSA234) with the same MIC/MBC values of 7.81/7.81 μgmL −1 .
Stark effect of excitons in individual air-suspended carbon nanotubes

We investigate electric-field induced redshifts of photoluminescence from individual single-walled carbon nanotubes. The shifts scale quadratically with field, while measurements with different excitation powers and energies show that effects from heating and relaxation pathways are small. We attribute the shifts to the Stark effect and characterize nanotubes with different chiralities. By taking into account exciton binding energies for air-suspended tubes, we find that theoretical predictions are in quantitative agreement.
A theoretical and experimental study on manipulating the structure and properties of carbon nanotubes using substitutional dopants

We examine the possibility of controlling nanotube growth and simultaneously manipulating the nanotube properties by adding elements in minute amounts (such as nitrogen, phosphorous, and sulfur) that are different from carbon and the metal catalyst during the growth process. This procedure is shown to be capable of producing bamboo-type morphologies, heterodoped carbon nanotubes, and Y-junctions. This also represents a critical step toward tailoring properties and controlling nanotube architectures, thus promoting the development of novel materials with unusual electronic applications. The underlying formation mechanisms that lead to the observed structures and morphologies are elucidated using wide-ranging electronic structure calculations that reveal the fundamentally different nature of nitrogen, phosphorous, and sulfur during carbon nanotube growth. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Dissociation of Colloidal Spheres According to LMO Law

New detailed results for ionic distributions around charged spherical surfaces in electrolyte solutions are presented using the formulation of dissociative electrical double layers (DEDL) with the Lubetkin, Middleton, and Ottewill dissociative law. Wide ranges of spherical radii and ionic strengths are considered. From these theoretical results the extent of ionic atmosphere and the number of ions contained therein are calculated to give an estimate of how many ions interact with a colloidal sphere. A new measure of the range of electrostatic repulsions is defined as the sum of the Debye length and the thickness of the co-ion exclusion shell. New results for extremely low charge densities indicate a possibility of significant electrostatic effects in such systems. These results, representing a synthesis of the classical theory of Debye−Huckel interionic interactions with the Derjaguin−Landau−Verwey−Overbeek (DLVO) theory, provide new insights into the co-ion exclusion phenomena in colloidal dispersions an.
THERMAL NEUTRON ACTIVATION ANALYSIS—AN IMPORTANT ANALYTICAL TOOL

ABSTRACT This review is intended to present an introduction to the use of thermal neutron activation analysis (TNAA) as an analytical technique for the determination of elements in almost all kinds of matrices. This method of analysis is generally multi-element and experimental conditions can be designed to be nondestructive to the sample. This review will focus on thermal neutron activation as this technique allows determination of approximately two-thirds of the elements on the periodic chart. There are also more and wider spread facilities in the United States that offer these services. The available facilities are located across the United States and are generally accessible to everyone. The review will also detail the advantages and disadvantages of TNAA compared to other common spectroscopic methods. An outline of the general procedure for performing the analysis of the elements using activation analysis is presented to emphasize the ease of using this technique. The outline is divided into sections that give the general procedure, how to choose the correct nuclear reaction and reaction product, and the main sources of errors that can affect the results of the study. These sources of error are subdivided into general types of errors. The general types of errors are divided into those related to pre-chemistry, problems associated with the irradiation of the samples, errors associated with the use of nuclear constants (cross sections, half-lives, transition probabilities, etc.), the choice of the correct reaction and reaction product, and those associated with the counting of the irradiated samples. The general theory of activation analysis is presented and summarizes the derivation of the equations used and the development of the comparator method of analysis. The comparator method is used to simplify the method by irradiating samples along with standards. This reduces the need for using the nuclear constants and thus reducing errors. The use of radiochemical separations to isolate analytes of choice from the radioactive matrix is also described. Some current literature is also included to give a feel for current applications of the use of thermal neutron activation analyses. The summary also describes some of the different matrices that have been used for analyses.
Direct Enzymatic Synthesis of Aspartame a

La synthese de l'aspartame a partir du L acide aspartique et de la L phenylalanine methyl ester peut etre effectuee par une enzyme extraite de Micrococcus caseolyticus, dans des conditions definies (pH, temperature, solvant, concentration en enzymes et substrat)
A New Butenolide-Type Fungal Pigment from the Mushroom Pulveroboletus ravenelii

A new butenolide-type fungal pigment, pulverolide (1) was isolated from the fresh fruiting bodies of Pulveroboletus ravenelii, together with a related known compound pulveraven A (2). The structure of pulverolide (1) was elucidated on the basis of spectroscopic studies including extensive 2D NMR experiments.
Application of magic-angle spinning NMR to examine the nature of protons in titanate nanotubes

Systematic magic-angle spinning (MAS) 1H NMR studies of protonated titanate nanotubes (produced by alkaline hydrothermal treatment of TiO2 with NaOH) have revealed that there are several types of protons incorporated into their wall structure, including crystallographic water molecules and ion-exchangeable OH groups. Each type (a) has a characteristic chemical shift and (b) disappears at a different rate during annealing in air. The evolution of protons in titanate nanotubes during crystallographic and morphological transformation in the sequence H2Ti3O7·xH2O, H2Ti3O7, H2Ti6O13, TiO2(B), TiO2(anatase) during calcination, at temperatures from 140 to 500 °C, has been studied using MAS NMR and Raman spectroscopies together with thermogravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The irreversible disappearance of ion-exchangeable OH groups has been observed, even under low temperature treatment.
Rheology and Flocculation of High-Pressure-Treated β-Lactoglobulin-Stabilized Emulsions: Comparison with Thermal Treatment

High-pressure treatment (HPT) has been shown to induce significant levels of flocculation in model oil-in-water emulsions stabilized by β-lactoglobulin at neutral pH, as indicated by changes in droplet size distribution and rheological behavior. Light microscopy has also provided additional evidence of extensive droplet flocculation following severe treatment. The proportion of unadsorbed protein greatly influences the extent of flocculation, and this may explain in part the nature of these pressure-induced effects. It has been observed that severe HPT (800 MPa for 60 min) is equivalent to relatively mild thermal treatment (TT) (65 °C for 5 min) in terms of the associated changes in emulsion gel rheology. Since HPT destabilizes these emulsion systems to a much lesser degree than TT, it can be considered to be a gentler processing operation in comparison. Emulsion flocculation is more sensitive to pressure and temperature at pH values closer to the isoelectric point and at higher ionic strength. That is, conditions favoring a loss of electrostatic stability tend to cause an increase in sensitivity toward pressure and temperature, although HPT consistently appears to be a gentler process than TT under all conditions studied.
Exploring the neural basis of fear produced by mental imagery: imaginal exposure in individuals fearful of spiders

Imaginal exposure, i.e. reducing fear using exposure to mental imagery, is a widely used psychological treatment technique for dysfunctional fears. Yet, little is known about its underlying neural mechanisms. The present study examines the neural basis of imaginal exposure using a novel experimental procedure consisting of repeated exposure to flashpoint mental imagery of phobic (spiders) and neutral (gloves) stimuli. Whether the 10 min long imaginal exposure procedure could reduce fear responses was examined one week later. Thirty participants fearful of spiders underwent the experimental procedure. Neural activity was assessed using functional magnetic resonance imaging (session 1). Subjective fear and skin conductance responses were measured throughout the study (sessions 1 and 2). Imaginal exposure evoked intense fear and heightened skin conductance responses, and indicated robust activation in several brain regions, including amygdala, midcingulate cortex and insula. Findings demonstrate that neural activity in fear-processing brain areas can be elicited solely by generating a mental image of a phobic stimulus, that is, in the absence of the percept. Relevant for treatment development, results reveal that a single 10 min session of brief exposures to flashpoint mental imagery can lead to lasting reductions in phobic fear at both the subjective and physiological levels. This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation'.
Weak polar host–guest interactions stabilizing a molecular cluster in a cyclodextrin cavity: C–H ⋯ O and C–H ⋯π contacts in β-cyclodextrin–but-2-yne-1, 4-diol heptahydratet

In the crystalline title complex, the guest molecules are ordered and the inclusion geometry is stabilized by a system of host–guest O–H ⋯ O, C–H ⋯ O and C–H ⋯π contacts; this is an example of weak but crucial polar interactions between the surface of a cyclodextrin cavity and a cluster of polar guest molecules.
An investigation into factors influencing intention to pay zakat: evidences from Nigeria

The research of intention to pay zakat in Kano Nigeria is still at the early stage. The main objective of this study is to examine factors influencing intention to pay zakat in Kano Nigeria. Questionnaires were collected from businessmen and businesswomen operating in Kano Nigeria using a cross-sectional study design. Questionnaires were distributed and collected through the personally-administered method. A total of 524 businessmen and businesswomen in Kano participated in this study. Partial Least Squares Structural Equation Modelling (PLS-SEM) was used and tested the study hypotheses. The study reveals that attitude toward zakat evasion, attitude toward moral reasoning, peer influence, zakat knowledge, quality of zakat distribution and perception of board capital are important determinants of intention to pay zakat in Kano Nigeria. However, attitude toward ethnic diversity, influence of religious leaders, zakat system structure and enforcement of zakat law are insignificant. Overall, the results indicates that, the study model provides a good understanding of the factors that influence intention to pay zakat specifically in Kano Nigeria. Finally, the study discussed theoretical, methodological contribution, practical implications as well as limitations and suggestions for future studies.
Nonequilibrium Thermodynamics of Cell Signaling

Signal transduction inside and across the cells, also called cellular signaling, is key to most biological functions and is ultimately related with both life and death of the organisms. The processes giving rise to the propagation of biosignals are complex and extremely cooperative and occur in a far-from thermodynamic equilibrium regime. They are also driven by activation kinetics strongly dependent on local energetics. For these reasons, a nonequilibrium thermodynamical description, taking into account not just the activation of second messengers, but also transport processes and dissipation is desirable. Here we present a proposal for such a formalism, that considers cells as small thermodynamical systems and incorporates the role of fluctuations as intrinsic to the dynamics in a spirit guided by mesoscopic nonequilibrium thermodynamics. We present also a minimal model for cellular signaling that includes contributions from activation, transport, and intrinsic fluctuations. We finally illustrate its feasibility by considering the case of FAS signaling which is a vital signal transduction pathway that determines either cell survival or death by apoptosis.
Lead Uptake by Lettuce and Oats as Affected by Lime, Nitrogen, and Sources of Lead

Uptake of lead by lettuce (Lactuca sativa L.) and oats (Avena sativa L.) as a result of application of lime, nitrogen, and various sources of lead to the soil was studied in a growth chamber experiment. Soil application of lead increased the uptake of lead by lettuce to a greater degree than by oats. Application of lime repressed the uptake of added lead by both plants, while application of low levels of nitrogen reduced the uptake of lead by lettuce and oat roots only. Application of lead chloride lowered the amount of sulfur and phosphorus in plants, but levels of other elements studied were not affected by any lead treatment.
Field Evaluation of Mulberry Root Structure with Regard to Phytoremediation

The root structure of a mature 12-year-old mulberry tree growing in a former waste disposal basin and the relationship of the tree's root system to the distribution of polycyclic aromatic hydrocarbons (PAHs) in soil/sludge beneath the tree were examined. Root excavation showed that large roots were restricted to the upper 60 cm of the root zone, whereas medium-sized (0.3 to 2.5 cm) and fine ( 2.0 m) showed dramatic differences. In the upper 60 cm of the root zone, where roots have prevailed for potentially 12 years, the PAH concentrations were approximately 10 to 20% of those in the sludge. At lower rooting depths 60 to 100 cm, where fewer roots have been present for a shorter time period, the PAH concentrations have decreased but to a lesser degree. These field results provide evidence that the mulberry root system develo.
Casein kinase 1: a new tale of chronic lymphocytic leukemia (CLL) microenvironment

The biological history of chronic lymphocytic leukemia (CLL) is strictly related to the ability of leukemic cells to invade and manipulate tissue microenvironments. This evidence is unequivocal by the observation that despite an apparent long life in vivo, CLL cells undergo in spontaneous apoptosis in vitro during culture in complete medium (1).
Connecting Systems with Short and Long Ranged Interactions: Local Molecular Field Theory for Ionic Fluids†

Structural and thermodynamic properties of ionic fluids are related to those of a simpler “mimic” system with short ranged intermolecular interactions in a spatially varying effective field by use of local molecular field (LMF) theory, already successfully applied to nonuniform simple fluids. By consistently using the LMF approximation to describe only the slowly varying part of the Coulomb interaction, which we view as arising from a rigid Gaussian charge distribution with an appropriately chosen width σ, exceptionally accurate results can be found. In this paper we study a uniform system of charged hard spheres in a uniform neutralizing background, where these ideas can be presented in their simplest form. At low densities the LMF theory reduces to a generalized version of the Poisson−Boltzmann approximation, but the predicted structure factor satisfies the exact Stillinger−Lovett moment conditions, and with optimal choice of σ the lowest order approximation remains accurate for much stronger couplings.
Solid‐state bonding of silicone elastomer to glass by vacuum oxygen plasma, atmospheric plasma, and vacuum ultraviolet light treatment

We experimentally demonstrated that treating a silicone elastomer by a vacuum oxygen plasma, an atmospheric pressure plasma, and vacuum ultraviolet (VUV) radiation resulted in different surface modifications that gave different contact angles, contact angle aging, and bond strengths. The aim of this study was to assess whether high‐throughput surface modification techniques of atmospheric pressure plasma and VUV radiation have the potential to replace conventional oxygen plasma modification. Four silicone elastomers with different hardnesses were used as specimens. The surfaces of all four silicone elastomers were successfully modified from hydrophobic to hydrophilic and they were also bonded to glass surfaces by the three surface modification techniques, although considerable variations were observed in the surface hydrophobicity and the bonding properties. The results clearly reveal that atmospheric pressure plasma and VUV treatment have the potential to replace conventional oxygen plasma treatment. In particular, VUV irradiation produced the most hydrophilic surface that was preserved for a long time. Thus, VUV irradiation is the most promising technique for realizing high‐throughput surface modification and bonding of silicone elastomers. Copyright © 2012 John Wiley & Sons, Ltd.
Dielectric Relaxation in PEO-MX Solid Electrolytes

Abstract Poiy(ethylene oxide) (PEO) complexed with salts has been shown to be characterized by a fair room temperature conductivity, high enough to allow technological applications. Dielectric Relaxation analysis technique is applied to study structural and transport properties of a number of normal and cross-linked PEO-based polymeric films.
High activity and durability of novel perovskite electrocatalysts for water oxidation

Development of highly active and cost-effective electrocatalysts is central to the large-scale electrolysis of water for renewable energy generation. Perovskite oxides are a group of promising candidates to lower the oxygen evolution reaction (OER) barriers in water splitting and further improvement of their activity and durability is an important objective. Here we report scandium and niobium cation (Sc3+ and Nb5+) doped strontium cobaltite perovskites (SrScxNbyCo1−x−yO3−δ) as a family of highly active and durable electrocatalysts for the OER in alkaline solution. These perovskites not only manifest up to a factor of 50 increase of the intrinsic activity compared to the gold-standard OER electrocatalysts (such as IrO2 and RuO2) and a factor of 5.8 enhancement to the perovskite-Ba0.5Sr0. 5Co0.8Fe0. 2O3−δ at an overpotential of 0.35 V, but also, more importantly, show excellent durability in alkaline solutions under operation.
Sulfonyl-containing modulators of serotonin receptors and their pharmacophore models

Data published in recent years on the synthesis of serotonin receptor modulators are summarized. Modulators with high affinity for receptors exhibiting different degrees of selectivity — from highly selective to semiselective and multimodal — are described. Clinical trial results are reported for the most promising serotonin receptor modulators attracting special attention of medicinal chemists. The bibliography includes 128 references.
Organogels and Liquid Crystalline Properties of Amino Acid-Based Dendrons: A Systematic Study on Structure–Property Relationship

Self-assembly behaviors of a series of amino acids-based dendrons, from the first generation (G1) to the third generation (G3) with various focal moieties or peripheral groups, were systematically studied. The supramolecular structures in organogels, thermotropic and lyotropic liquid crystals (LCs) were measured. The influence of the focal groups, dendritic branches, and generation numbers on the mesophase of organogels or LCs was studied by a combination of experimental techniques including transmission electronic spectrometry (TEM), atomic force microscopy (AFM), infrared (IR) spectra, wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). It was found that the gelation ability of the dendrons in organic solvents was highly related to the generation; namely, none of the G1 dendrons could form organogels, G2 dendrons displayed good gelation ability, and G3 dendrons gelled the organic solvents with the lowest critical gelation concentration. Oscillatory shear measurements indicated .
Sorption-desorption of atrazine and simazine by model soil colloidal components

Sorption-desorption of atrazine and simazine on montmorillonite, ferrihydrite, and humic acid was determined using the batch equilibration procedure. Sorption of atrazine and simazine was higher on humic acid than on montmorillonite. Ferrihydrite does not sorb triazine herbicides. Enhanced sorption of atrazine and simazine on montmorillonite was measured after increasing the surface acidity of the clay. Results indicate sorption of s-triazine herbicides on montmorillonite as protonated species must be preceded by sorption as molecular species on hydrophobic microsites of the clay unless the pH of the bulk solution is close to the pK a of the herbicide. In this latter case, cation exchange would be also operative. Sorption-desorption of atrazine and simazine was more hysteretic for humic acid than for montmorillonite, indicating that these herbicides desorb more difficultly from organic matter than from montmorillonite because of the contribution of hydrophobic interactions with humic acid. It is suggested that, besides organic matter, smectites of low charge density and high surface acidity should increase the retention of s-triazine herbicides in soils.