Miracle-dz/UniFAR-FTUs huggingface dataset:
Cadmium‐induced alterations in nutrient composition and growth of betula pendula seedlings: The significance of fine roots as a primary target for cadmium toxicity

Abstract Birch seedlings (Betula pendula) were cultivated in nutrient solution with 0–2 μM cadmium (Cd). The effects of 2–10 days of Cd exposure on root and shoot element composition [potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), sulfur (S), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), and Cd] and growth (as percentage dry weight increase) were investigated. The element composition of fine roots and remaining root parts were analysed separately to elucidate the significance of the fine roots as a primary target for Cd toxicity. The nutrient composition of the roots was considerably altered by the Cd exposures, whereas the nutrient composition of the shoot was less affected. After eight days, the whole root (fine roots + remaining roots) concentrations of K, Ca, Mg, and Mn were reduced, whereas the opposite was found for Cu and Mo. The element distribution between fine roots and remaining roots was altered by the Cd exposures. Cadmium was accumulated in the roots and i.
Self-assembled hexasaccharides : Surface characterization of thiol-terminated sugars adsorbed on a gold surface

A thiol-terminated hexasaccharide, protected with acetyl groups (AHS) was synthesized for the purpose of depositing self-assembled monolayers (SAMs) from solution onto gold surfaces. X-ray photoelectron spectroscopy (XPS), ellipsometry, contact angle measurements, and imaging time-of-flight secondary ion mass spectroscopy (iToF-SIMS) were used to determine coverage, homogeneity, chemical composition, film thicknesses, and kinetics of film growth. Deprotection of the molecules, i.e. replacing acetoxy groups by hydroxyl groups, was performed following adsorption of AHS onto the surface, as well as prior to adsorption from solution. The chemical composition of the resulting films, the film thickness, the density of molecules, and the nature of the surface functional groups were determined. Adsorption of the deprotected molecules (DHS) from solution was found to lead to a higher density of adsorbed species.
A Numerical Simulation Studying for Plasma Expansion in Laser Ablation Processing

A numerical simulation is proposed to study the dynamics expansion characteristics during the material irradiated by a high-intensity laser beam.The ionization effect and the local mass and momentum conservations for plasma expansion are considered in this model. As an example of carbon target, the plasma flow dynamics into a vacuum, like ionization degree, plasma number density and space pressure are studied in detail. The results show the plasma temperature strongly affects the ionization fraction and the ionization effect evidently influences the plasma dynamic expansion behavior. The space pressure of plasma decreases along with the plasma expansion.
A New Role for Sulfenate Anions: Organocatalysis

Organocatalysis is now commonplace as a means to create carbon–carbon bonds in an efficient, green and stereoselective manner, all in the absence of transition metals. The number of research contributions outlining organocatalyst use has undergone an astounding increase in recent years. A major factor in the emergence and growth of this field has been the imagination and resourcefulness of researchers, traits that brought them to envision, source and exploit a broad collection of structural motifs to act as catalysts. Similarly, the number of reactions that have been re-examined under the lens of organocatalysis is remarkable. To add to the vast number of past contributions, it is time to introduce a new player in the field. Walsh and co-workers have unveiled the sulfenate anion as an organocatalyst for the conversion of benzyl halides to symmetrically substituted stilbenes. The sulfenate anion is the conjugate base of a sulfenic acid (Figure 1). Both of these entities have a reputation for being transient and their isolation is possible but only if the com-
Highly soluble multifunctional MnO nanoparticles for simultaneous optical and MRI imaging and cancer treatment using photodynamic therapy

Superparamagnetic MnO nanoparticles were functionalized using a hydrophilic ligand containing protoporphyrin IX as photosensitizer. By virtue of their magnetic properties these nanoparticles may serve as contrast enhancing agents for magnetic resonance imaging (MRI), while the fluorescent target ligand protoporphyrin IX allows simultaneous tumor detection and treatment by photodynamic therapy (PDT). Caki-1 cells were incubated with these nanoparticles. Subsequent exposure to UV light lead to cell apoptosis due to photoactivation of the photosensitizer conjugated to the nanoparticles. This method offers great diagnostic potential for highly proliferative tissues, including tumors. In addition, it is an efficient platform that combines the advantages of a biocompatible photosensitizer with the possibility for MRI monitoring due to the magnetic properties of the highly soluble functionalized manganese oxide nanoparticles.
Preparation and characterization of hexagonal MnTe and ZnO layers

MnTe layers of high crystalline quality were grown on Al2O3 substrates (0001)-oriented by molecular beam epitaxy (MBE). Characterization of MnTe by X-ray diffraction (XRD) revealed a hexagonal structure of NiAs-type with lattice parameters a = 4.166 A and c = 6.694 A. The energy gap of MnTe, evaluated from the optical transmission spectra measured at 10 K, was found to be 1.7 eV. The Neel temperature obtained from neutron diffraction (ND) measurements was 284.1 K. ZnO:N layers were fabricated by thermal oxidation of metallic Zn and ZnTe grown by MBE on different substrates. In order to achieve p-type conductivity, the starting materials were doped by nitrogen. The XRD spectra of the oxidized samples showed peaks related to hexagonal ZnO. The Hall measurements demonstrated p-type conductivity with the hole concentration of ∼2.2 × 1019 cm–3 and ∼6.7 × 1017 cm–3 for ZnO:N deposited on GaAs and ZnTe, respectively. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
A gentle vapor-diffusion technique for cross-linking of protein crystals for cryocrystallography

Protein crystals have been cross-linked by a gentle technique whereby glutaraldehyde is introduced by vapor diffusion into the crystallization droplet containing the crystals. Diffraction analyses of crystals of three different proteins show that cross-linking prevents, in a large part, the lattice disorder normally observed on rapid cooling of these crystals. The diffraction results suggest that this cross-linking procedure, performed as a simple extension of the standard vapor-diffusion crystallization experiment, may generally aid in the cooling of fragile protein crystals for which standard procedures of cryopreservation prove inadequate.
Ultramicroelectrode ensembles. Comparison of experimental and theoretical responses and evaluation of electroanalytical detection limits

Abstract : The ultramicroelectrode ensembles yield responses which are in quantitative agreement with predictions of established electrochemical theory. Furthermore, a one order of magnitude improvement in detection limits (relative to a conventional, macro-sized electrode) is demonstrated. In a recent correspondence, we described a new procedure for preparing ultramicrodisk electrode ensembles; the ultramicrodisks were formed by filling the pores of a microporous host menbrane with carbon paste. In this paper we present results of quantitative and semi-quantitative analyses of the electrochemical response characteristics of these ultramicroelectrode ensembles; we show that the responses are in agreement with predictions of established electrochemical theory. We also show that one of the ensembles investigated here can yield electroanalytical detection limits which are order of a magnitude lower than detection limits at an equivalent macro-sized (0.331 sq.cm.) electrode. Ultramicrodisk electrode, Electrochemical response, Electroanalytical detection limits.
Theoretical study of B3O radical isomers and their interconversion pathways

Despite the fact that B3O is the second simplest B n O radical after BO, a controversy recently emerged concerning the molecular structure of its global minimum. Two recent theoretical groups predicted the linear quartet BBBO to be the ground isomer. By contrast, another recent theoretical group reported that B3O has a doublet B3-ring ground structure. Moreover, larger B n O clusters usually have low-lying B3-ring isomers. In order to determine the accurate energetic competition between linear and cyclic structures in both the doublet and quartet, and to understand the detailed isomerism between various isomers, which is vital for understanding the formation mechanism of B3O, we report the first potential energy surface (PES) study of B3O at various computational levels, including CCSD(T)/6-311+G(2df), CCSD(T)/aug-cc-pVTZ, CCSD(T)/aug-cc-pVQZ and G3B3 for the single-point energy, as well as B3LYP/6-311+G(d) and QCISD/6-311+G(d) for geometrical optimisation. It is shown that the isomers in the quartet state are all thermodynamically more stable than the corresponding doublet ones, and on both the quartet and doublet PESs, the linear form has the lowest energy. Therefore, our study on both linear and cyclic isomers shows that the linear quartet BBBO 4 01 is definitively the ground isomer. Although being much less stable than the quartet linear BBBO global minimum by >20 kcal mol−1, five cyclic isomers exist as local minima, with the bi-cyclic structure 4 02 possessing the smallest barrier of around 15 kcal mol−1. The dissociation energies for direct combination processes B3 + O, B2 + BO and B + B2O are discussed. The present work may be helpful in obtaining a deep understanding of the doping and oxidation process of pure B n clusters.
Influence of water on the infrared spectrum of crystalline N-methylacetamide

Infrared spectra of crystalline N‐methylacetamide (NMA) at room temperature and near liquid helium temperature are reported for the pure vacuum distilled substance, and the same with defined amounts of water added. Several lines turn out to be highly water sensitive: those assigned to amide VI and IV, those at 804 and 1384 cm−1, and the one at 1413 cm−1 which is assigned to CH3(−N) sym. bend, the amide I and II bands, and two lines at 3103 and 3300 cm−1 mainly assigned to ν NH vibrations. It seems the spectra reported up to now have to be reconsidered cautiously concerning the water content of the samples and the assignments have to be thought through again.
Spectroscopic characterization of an atmospheric pressure μ-jet plasma source

A new method for determination of plasma parameters under atmospheric pressure conditions is formulated and applied for characterization of a radio-frequency μ-jet plasma source using He/O2 mixture. By applying absolutely calibrated optical emission spectroscopy and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined. The steady-state concentrations of different species such as oxygen atom and ozone in the plasma channel and in the effluent of the plasma source are calculated using measured plasma parameters and gas temperature. On the other hand, spatial distribution of steady-state densities of these species are measured using emission and absorption spectroscopy. A comparison of the results thus obtained and the validation of the new method against two-photon absorption laser-induced fluorescence spectroscopy measurements are discussed. In addition, the influence of the surface processes and gas flow regime on the loss of the active species in the plasma source are discussed.
Efficiency Droop Characteristics in InGaN-Based Near Ultraviolet-to-Blue Light-Emitting Diodes

In this study, we prepared InGaN-based light-emitting diodes (LEDs) with peak emissions ranging from 400 to 445 nm and investigated their efficiency droop characteristics at injection currents of up to 1 A. We found that the external quantum efficiencies (EQEs) changed dramatically when the critical current increased from 0 to 350 mA, but exhibited a similar negative slope upon increasing the current from 350 mA to 1 A. The effects of piezoelectric polarization and different localized states in the active layer of the near UV-to-blue LEDs influenced the peak EQEs and the dramatic decays of the EQE droops at lower injection currents.
Use of the atomic force microscope to determine the effect of substratum surface topography on bacterial adhesion

Changes in surface roughness and topography on the macroscopic scale are known to affect bacterial attachment and retention. Little quantitative information is available as to how changes in surface topography on the micron and submicron scale affect the strength of bacterial attachment to substrata. A novel method is described using the atomic force microscope where a varying shear/lateral force (in nanonewtons) is used to detach individual bacterial cells from various substrata of different surface topographies. Lateral changes of 0.1 μm in the surface topography are sufficient to affect the strength of bacterial attachment. An increase in applied force from 4 to 8 nN was necessary to move bacteria retained in surface defects of approximately 1 μm wide and 0.2 μm deep compared with cells attached on smooth surfaces.
Isobaric vapor-liquid equilibria of binary mixtures containing dimethyl carbonate under atmospheric pressure

Isobaric vapor−liquid equilibria (VLE) have been determined for the binary systems of dimethyl carbonate (DMC) + ethanol, dimethyl carbonate + diethyl carbonate (DEC), dimethyl carbonate + propylene glycol (PG), and dimethyl carbonate + propylene carbonate (PC) under atmospheric pressure in an Ellis equilibrium still. The data have been checked by employing a global statistic thermodynamic consistency test and also have been correlated by means of both the Wilson equation and the NRTL equation. The experimental results demonstrated that the systems of DMC + ethanol and DMC + PG show strong positive deviations from ideality and that the systems of DMC + DEC and DMC + PC are close to ideality.
151. The reactions and properties of annatto as a cheese colour, with particular reference to the chemistry of cheese discoloration

The properties of commercial annatto solutions have been examined from the point of view of the cheese-making process. (1) The effect of initial colour strength, pH of the medium and distribution during manufacture are recorded. (2) Methods are described for the extraction of the annatto colour from milk products. (3) The effects of old annatto solutions, metallic impurities (copper and iron) and sulphydryl are shown. (4) It is suggested that the mechanism underlying the development of “bleached” and “pink” discoloration in cheese is an oxidation process, and the effect of oxidation on annatto solutions has been studied in some detail. (5) Suggested standards for annatto extracts for use as cheese colours are appended.
N-Isobutyl­phthalimide: unidimensional zigzag ribbons of R(10) motifs

Institute of Organic Chemistry, University ofCologne, Greinstr. 4, D-50939 Cologne,GermanyCorrespondence e-mail:klaus.warzecha@uni-koeln.deKey indicatorsSingle-crystal X-ray studyT = 100 KMean (C–C) = 0.002 A˚R factor = 0.039wR factor = 0.095Data-to-parameter ratio = 11.7For details of how these key indicators wereautomatically derived from the article, seehttp://journals.iucr. org/e.Received 28 September 2006Accepted 30 September 2006
Periodic mesoporous organosilica with ionic-liquid framework supported manganese: an efficient and recyclable nanocatalyst for the unsymmetric Hantzsch reaction

An efficient approach for the green and rapid synthesis of biologically active substituted polyhydroquinoline derivatives via unsymmetric Hantzsch reaction using an ionic liquid based periodic mesoporous organosilica supported manganese (Mn@PMO-IL) catalyst under solvent-free conditions is described. This catalyst showed high reactivity and selectivity for the preparation of a set of different derivatives of polyhydroquinolines under moderate reaction conditions and short times. Moreover, the catalyst was also recovered and reused several times without important decrease in reactivity and yields. The nitrogen adsorption–desorption and transmission electron microscopy of the recovered catalyst significantly proved the high stability and durability of the catalyst under applied reaction conditions. Furthermore, compared to the classical methodologies, this method consistently illustrated the advantages of short reaction times, low catalyst loading, high yields, easy separation and purification of the products, and high recoverability and reusability of the catalyst.
Surface chelation of semiconductors and interfacial electron transfer

The effect of surface chelation of oxide semiconductors on interfacial electron transfer was investigated. The studies employed phenylfluorone (2,6,7-trihydroxy-9-phenylisoxanthen-3-one), PF, as a chelating agent and titanium dioxide as a semiconductor. Pt forms a chelate with surface titanium ions which was characterized by UV-vis and IR spectroscopy. Laser photolysis and cyclic voltametric investigations indicate that surface chelation by PF drastically accelerates the electron transfer from the conduction band of TiO{sub 2} to solution acceptors such as methylviologen.
Size-Dependent Optical Properties of Colloidal ZnO Nanoparticles Charged by Photoexcitation

The above-bandgap illumination of colloidal ZnO nanoparticles (NPs) in ethanol solutions is found to lead to reversible shifts of the absorption and photoluminescence (PL) excitation spectra, indicating charging of the nanoparticles with electrons. A rapid drop of deep-level PL intensity at the early stage of illumination is observed simultaneously with the splitting-off and growth of a new red-shifted near-band-edge PL band. Such a splitting of the near-bandgap PL band under illumination is observed for the first time and corroborates with the previous assumptions about the behavior of the NP ensemble emission upon gradual NPs’ charging with electrons. The possible relation between the new PL band and photoinduced charging of NPs with excess electrons is discussed on the basis of the dependence of the PL spectrum evolution and absorption band shift relaxation on the NP size and controllable access of oxygen during illumination.
New electron and hole spectroscopies based on ballistic electron emission microscopy

Ballistic electron emission microscopy (BEEM) is shown to be one of a class of carrier transport nanospectroscopies which measure both elastic and inelastic transport of electrons and holes in thin film structures. In BEEM, electrons are injected into a metal film from a tunnel tip and are collected in the substrate after ballistic transport through the film. An analogous spectroscopy can be performed using hole transport into a p‐type semiconductor substrate. In the present work, it is shown that inelastic scattering in metal films results in electron‐hole pair creation which can be detected by similar techniques. A theory for this spectroscopy successfully explains the experimental results.
Refined Crystal Structure of Human Transforming Growth Factor β2 at 1·5 Å Resolution

Abstract Transforming growth factor β2, (TGF-β2), a homodimeric protein, is a member of a family of structurally related polypeptides that regulate various growth and differentiation processes in many cell types. The crystal structure of recombinant human TGF-β2 has been determined using a single heavy-atom derivative, anomalous scattering and by applying solvent flattening. The molecular model has been refined by a combination of simulated annealing and restrained least-squares refinement to a crystallographic R -factor of 0·194 including all data from 1·95 A to 8·0 A resolution. In the final structure, the root-mean-square deviation for bond lengths is 0·007 A and for bond angles 1·97°. The final model includes 890 protein atoms (all 112 amino acid residues) as well as 84 water molecules. The new monomer fold consists of a separate α-helix and two pairs of antiparallel β-sheet segments, which can be subdivided into nine individual β-strands. The extended monomer lacks the typical hydrophobic core. A cluster of disulfide bridges, including the TGF-β knot, connects the β-strands with each other as well as the α-helix. Two monomers are covalently linked by a single disulfide bridge. In the dimer the α-helix of one subunit interacts with the β-sheet of the other subunit forming two symmetrically related hydrophobic cores. The center of the dimer interaction is stabilized by a network of hydrogen bonds including several well-defined water molecules, which surround the central intersubunit disulfide bridge. The refined structure reveals the details of hydrogen bonding, electrostatic and hydropholic interactions between intra- and intersubunit residues and allows the identification of possible receptor binding segments.
Methane Emission from an Indonesian Paddy Field Subjected to Several Fertilizer Treatments

Abstract Methane emission rates from a paddy field in Indonesia subjected to several fertilizer treatments were measured every week throughout the rice growing period. The mean CH4 emission rates (mg CH4 m-2 h-1) throughout whole growth period were in the ranges of 18.0–23.2 from chemical fertilizer plots and 19.5–27.1 from plots amended with both urea and organic materials. These rates were in the range of those reported from respective treatments in the temperate region. The effects of application of organic materials on the CH4 emission rates were less conspicuous than those of the reported results. The total CH4 emission (g CH4 m-2) throughout the growth period amounted to 31–40 from chemical fertilizer plots and 34-47 from plots amended with organic materials, respectively. Methane was mainly emitted in the first half of the growth period irrespective of treatments, which was in accordance with the results obtained in Thailand, and in contrast to those reported in the temperate region, where CH4 emis.
Inhibition of methicillin‐resistant Staphylococcus aureus (MRSA) by essential oils

Ninety-one essential oils, each distilled from a single plant source, and 64 blended essential oils obtained from a commercial source were screened using the disc diffusion assay for inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA). Of the 91 single essential oils, 78 exhibited zones of inhibition against MRSA, with lemongrass, lemon myrtle, mountain savory, cinnamon and melissa essential oils having the highest levels of inhibition. Of 64 blended essential oils, 52 exhibited inhibitory activity against MRSA, with R.C. (a combination of myrtle, Eucalyptus globulus, Eucalyptus australiana, Eucalyptus radiata, marjoram, pine, cypress, lavender, spruce, peppermint and Eucalyptus citriodora oils), Motivation (a combination of Roman chamomile, ylang ylang, spruce and lavender oils) and Longevity (a combination of frankincense, clove, orange and thyme oils) blended essential oils having the highest inhibitory activity. These results indicate that essential oils alone and in combination can inhibit MRSA in vitro. Application of these results may include the potential use of essential oils as an alternative therapy for various diseases sustained by S. aureus MRSA. Copyright © 2008 John Wiley & Sons, Ltd.