Miracle-dz/UniFAR-FTUs huggingface dataset:
Atomic-scale lateral heterogeneity and dynamics of two-component lipid bilayers composed of saturated and unsaturated phosphatidylcholines

Studies of lateral heterogeneity in cell membranes are important since they help to understand the physical origin of lipid domains and rafts. The simplest membrane mimics are hydrated bilayers composed of saturated and unsaturated lipids. While their atomic structural details resist easy experimental characterization, important insight can be gained via computer modeling. We present the results of all-atom molecular dynamics simulations for a series of fluid dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) bilayers. Lateral arrangement of lipids in these systems is not random and reveals small geometrical and hydrophobic clusters on the surface. Being “sharp” inside the bilayer, lateral heterogeneity is very “fuzzy” on the surface. This picture is highly dynamic – lifetimes of clusters are ∼1 ns. In the binary system, DPPC acts as an “order-preferring” agent, which efficiently modulates behavior of DOPC. Bilayer properties are tuned in a wide range by the chemical nature and relative content of lipids. The impact that the micro-heterogeneity may have on formation of lateral domains in response to external signals is discussed. Understanding of such effects creates a basis for rational design of artificial membranes with predefined properties.
Local order in wüstite using a pair distribution function (PDF) approach

Abstract We show how different aspects of a model of the complex disordered structure of wüstite, Fe1-xO, affect the pair distribution function (PDF) and powder diffraction pattern. The aim is to assess the efficacy of using these techniques to determine details of local structure. The different aspects include the nature of the individual defect clusters, the nature of the paracrystalline superlattice on which they are distributed and the 'size-effect' relaxation of the basic rocksalt FeO matrix around the defects. The results show that PDF data are sensitive to those aspects of the models that have a significant effect on the populations of interatomic spacings but are less able to determine correlation structures in the samples if these do not have a substantial interaction with interatomic separations.
Influence of Iron Fertilization on Cadmium Uptake by Rice Seedlings Irrigated with Cadmium Solution

A pot experiment investigated the effects of iron (Fe) fertilization on cadmium (Cd) uptake by rice seedlings irrigated with Cd solution. Shoot dry weight was significantly affected by Fe addition, and root dry weight was affected by Cd addition. Iron supply was the dominant factor affecting the length of the longest leaf and the soil and plant analyzer development (SPAD) value. Cadmium concentrations were much greater in roots than in dithionite–citrate–bicarbonate (DCB) extracts or shoots, and a significant correlation was found between shoot Fe and Cd concentrations. Enhanced Cd uptake observed at high Fe supply implies that enhanced Fe nutrition may counteract the adverse effects of Cd on plants.
A critical review of the separation of arsenic oxyanions from dilute aqueous solution (the contribution of LGICT)

This paper presents an overview of research related to the effective removal (by sorption and/or flotation) of arsenates and arsenites from aqueous effluents, as exerted in depth at GICT Laboratory of Chemistry Department in Aristotle University during the last decade. This paper presents, compares and comments the results of more than 20 scientific papers. Equilibrium, thermodynamic and kinetic studies were carried out to determine the sorption capacity of ten materials under various experimental conditions. The highest sorption capacity corresponds to surfactant-modified akaganeite and was found to be 328 mg g –1 , while the obtained flotation recoveries were higher than 90%.
Temperature-Sensitive Properties of Poly(N-isopropylacrylamide) Mesoglobules Formed in Dilute Aqueous Solutions Heated above Their Demixing Point

The kinetics of merging and/or chain exchange between mesoglobules formed in dilute aqueous solutions of fluorescently labeled poly(N-isopropylacrylamides) (PNIPAM) heated above their demixing temperature (Tdem) were monitored at specific temperatures between 30 and 50 °C via nonradiative energy transfer (NRET) using polymers carrying ∼0.25 mol % of either naphthyl (Np, energy donor) or pyrene (Py, energy acceptor). Dynamic and static light scattering measurements (DSL and SLS) indicated that PNIPAM-Py and PNIPAM-Np solutions form stable mesoglobules when heated above 30 °C and that the size and size distribution of the mesoglobules depend on solution concentration and, more importantly, on the sample thermal history. Fluorescence depolarization measurements performed on mesoglobular solutions of PNIPAM-Np gave the temperature dependence of the probe anisotropy, an indication of the microviscosity sensed by the probe. The results show that samples heated within the ∼31 °C < T < 36 °C range consist of flui.
Multifunctionalization of carbon nanotube fibers with the aid of graphene wrapping

Carbon nanotube (CNT) fibers are promising candidates for developing multifunctional textiles. The direct introduction of functional guests within or around CNT fibers meets problems due to the rough fiber surface and weak interfacial bindings. To improve the functionality and performance stability, we report a new method to modify the surface roughness and level of functionalization of CNT fibers, by wrapping graphene oxide (GO) or reduced graphene (RG) around them. Besides the functional groups on the graphene sheets, the introduction of a graphene layer also has smoothing and shield effects, resulting in higher tensile strength and improved and stabilized performance. The electrochemical and photocurrent applications were exploited by depositing polyaniline around GO-wrapped CNT fibers and TiO2 around RG-wrapped fibers, with a capacitance up to 229.5 F cm−3 and a photocurrent density of 132 μA cm−2, respectively. The present technique has the advantage that the mechanical and functional properties can be optimized by simply modifying the core CNT fiber via polymer infiltration during the fiber spinning.
Water as a reaction medium for nickel(II)-catalyzed ethylene polymerization

Introduction As the most environmentally friendly common solvent conceivable, water also possesses other unique properties as a reaction medium: it is highly polar and immiscible with most organic compounds, has a high heat capacity and also features a strong propensity for micelle formation in the presence of surfactants. These features are exploited in radical emulsion and suspension polymerization of olefinic monomers, such as butadiene, styrene and acrylates on a large scale. Also, transition metal catalysis in aqueous media involving the synthesis of low molecular weight compounds (commercialized in the Ruhrchemie/RhonePoulenc hydroformylation process) is currently attracting strong interest. By contrast transition metal catalyzed coordination polymerization reactions in water have received less attention, as the common early transition metal catalysts are extremely sensitive to moisture. Due to their less oxophilic nature, late transition metal complexes are generally less sensitive to polar media. However, the C-C linkage of ethylene in general (i.e. in organic reaction media) usually yields dimers and oligomers, due to the propensity of late transition metal alkyl complexes for β-hydride elimination. In comparison to early transition metal catalysts, only a relatively limited number of late metal catalysts applicable to polymerization yielding high molecular weight products are known. Most of them are based either on neutral nickel(II) complexes or on cationic iron, cobalt, nickel or palladium complexes. The neutral nickel(II) complexes contain a formally monoanionic bidentate ligand, usually binding via an oxygen donor and another donor atom such as P or N, whereas the cationic complexes contain neutral multidentate ligands with bulky substituted nitrogen donor atoms. The aforementioned stability of late transition metal complexes with respect to polar media is demonstrated by the tolerance of such catalysts towards polar functionalized comonomers and polar organic solvents Concerning water as a medium for coordination polymerization, a very slow (1 turnover/day) reaction of ethylene to higher molecular weight linear product, catalyzed by a rhodium complex, has been reported.
Effect of Organic Matter Application on Methane Emission from Some Japanese Paddy Fields

Abstract Emission rates of CH4 from four Japanese paddy fields were measured throughout the cultivation period in 1988 by using the closed chamber method. Large seasonal variations of the CH4 flux were observed. The emission was closely related to the decrease of the redox potential (Eh) in paddy soils. Drainage and supplementary application of mineral fertilizer substantially reduced the CH4 emission. Emission rates of CH4 differed markedly with the soil types. The highest rate was observed in a paddy field consisting of Peat soil (44.8 g-CH4/m2 during a cultivation period), followed by Gley soil (8.0-27.0). The emission rates in the Andosols were significantly lower (0.6-12.6). Application of rice straw at a rate of 6-9 t/ha to the paddy fields increased the CH4 emission rates 1.8- to 3.5-fold. Application of compost slightly increased the CH4 emission. Annual emission rates of CH4 from individual plots were positively correlated with the contents of readily mineralizable carbon (RMC) in paddy soils col.
Flame Retardants in Commercial Use or Development for Textiles

Non-durable and semi-durable flame retardants based mostly on phosphate or phosphonate salts continue to be used on infrequently washed or disposable goods, and recent improvements have been made to impart better `hand' or some limited wash resistance. Backcoating with insoluble ammonium polyphosphate, usually with additives and binders to provide intumescence, has been found effective on charrable fabrics. However, the leading backcoating effective on a wider range of fabrics, including synthetics and blends, is decabromodiphenyl ether plus antimony oxide. Newer candidates in development for textile coating are polymers and copolymers of pentabromobenzyl acrylate. The leading durable finish for cellulosic fibers, in use for about 50 years, continues to be based on tetrakis(hydroxymethyl)phosphonium salts reacted with urea and cured with gaseous ammonia. Softer versions have been recently developed using chemical or process modifications, or using selected fiber blends. Somewhat less durable phosphonic ester methylolamide finishes, not requiring gaseous curing, are used on cellulosic fabrics, especially overseas. Other competitive wash-durable phosphorus-based finishes for cellulosics and blends are in development. Polyesters continue to be flame retarded using a phosphonate or hexabromocyclododecane in a `thermosol' process. Polyesters with built-in phosphinate structures are available as specialty fabrics. A dialkylphosphinate salt has been recently introduced as a melt spinning additive in polyester. A tribromoneopentyl phosphate melt spinning additive has been developed for polypropylene fiber. A number of inherently flame retardant synthetic fibers recently achieving increased usage include melamine-based fiber, viscose rayon containing silicic acid, aramides, oxidized polyacrylonitrile, and polyphenylene sulfide fibers. Some of these are used in protective clothing. The recent California and Federal mattress open-flame test standards have brought barrier fabrics into prominence. Some of these barriers use boric acid on cotton batting, others are proprietary composites and blends, both woven and nonwoven, comprising inherently flame retarded fibers combined with lower cost non-flame-retardant fibers. Upholstered furniture open-flame standards are pending.
Functional Properties and Biscuit Making Potentials of Sorghum-wheat Flour Composite

The rapid urbanization and increase in population in recent years have resulted in an increase in the consumption of wheat-based products especially biscuits in sub-Saharan Africa. This has spurred pragmatic research on compositing flour from locally cultivated cereals to reduce wheat importation. This study was therefore, conducted to investigate the functional properties of sorghum-wheat composite flour and its biscuit making potentials. Sorghum grain was processed into flour and used to substitute wheat flour at different proportions (0, 5, 10, 15 and 20%). The functional and pasting properties of the different sorghum-wheat flour blends were determined. The composite flours were thereafter, processed into biscuit and the physical dimensions and proximate composition of the biscuits were determined. There were significant differences (p 0.05) in the pasting profile of the wheat-sorghum flour blends except for set back viscosity and pasting temperature. Highest values of 11.84, 2.36, 1.95 and 5.31% were recorded by biscuit from 90:10% wheat-sorghum composite flours in terms of protein, ash, fibre and sugar, respectively. There were significant differences (p 0.05) was found in the physical dimensions of the wheat-sorghum flour biscuits. The study concluded that biscuits of acceptable quality, comparable to the quality of 100% wheat flour biscuits are obtainable from sorghum-wheat composite flour. The use of sorghum in biscuits making would greatly enhance the utilization of this crop in many sorghum cultivating developing countries where the crop has not been optimally utilized.
Radionuclide sorption to a mixture of anaerobic bacteria in the repository environment

Abstract The sorption of the radionuclides, Pu, Np, Pa, Sr and Cs, to a mixture of anaerobic bacteria activated under specific conditions of temperature, pH and depleted nutrients after a long dormant period has been investigated. For Pu, after 4 hours at neutral pH, the distribution coefficient (Kd) between bacteria and aqueous phase at 308 and 278 K was around 103'4 (ml g"1). Over 5 days, however, the Kd at 308 K increased to over 105. Sterilized (dead) and dormant anaerobic bacteria adsorbed Pu to the same extent. Kd for Np at 308 K after 5 days had a low value around 102. After 10 days, however, Kd was > 100-fold higher. On the other hand, Kd for Np at 278 K remained low, without any significant increase over time. The interaction between Pa and bacteria was found to be stronger than that for Np, with Kd for Pa about 100 times higher. For Sr and Ca, significant Kd change was not seen through 120 d. The value for Sr is a few times larger than that for Cs due to the different electrostatic interaction with the bacteria based on the charge of ion.
Uniformity and control of surface morphology during growth of GaN by molecular beam epitaxy

A “modulated growth” technique has been introduced to achieve large area uniformity and surface morphology control during rf plasma assisted molecular beam epitaxy of GaN. The technique consists of modulating the surface coverage of Ga through short-period shuttering of Ga, N, or Ga and N together (e.g., 50–100A growth periods), to achieve alternating high and low surface coverages of Ga on the (0001) GaN surface. The periods of growth with high Ga flux provide saturation coverage of Ga (∼2.5 ML Ga plus Ga droplets) over the full wafer, while the subsequent growth with low Ga flux facilitates a time-averaged Ga flux which is just below the crossover for droplet formation at the growth temperature. The growth transients in the Ga droplet regime are necessary to maintain smooth, pit-free surface morphologies, and the subsequent growth with low Ga flux suppresses droplet buildup over time. The process is monitored in situ utilizing reflection high energy electron diffraction and line-of-sight quadrupole mass.
COMPARAÇÃO DO USO DE MODELOS DIGITAIS DE ELEVAÇÃO EM MAPEAMENTO DIGITAL DE SOLOS EM DOIS IRMÃOS, RS, BRASIL

Os modelos digitais de elevacao (MDEs) sao fontes fundamentais para correlacionar a ocorrencia e distribuicao de solos com a paisagem pelo mapeamento digital de solos (MDS). A influencia dos tipos e das resolucoes dos MDEs na capacidade de predicao dos modelos preditores de classes de solo ainda e pouco estudada. Neste estudo, foram avaliados e comparados os efeitos de diferentes MDEs na predicao de ocorrencia de unidades de mapeamento de solo (UM). Foram correlacionados 12 atributos do terreno derivados de diferentes MDEs com a ocorrencia de UM. Os MDEs utilizados foram os oriundos dos projetos SRTM v4.1, ASTER GDEM v2, TOPODATA e Brasil em Relevo, e os MDEs gerados a partir de curvas de nivel na escala de 1:50.000, com resolucoes de 30 e 90 m. Os modelos preditores foram treinados por arvore de decisao (Simple Cart) com dados amostrados em 4.280 pontos aleatorios contendo informacoes dos solos extraidos de um mapa convencional de solos na escala 1:20.000 e 12 atributos do terreno derivados de seis MDEs com tamanhos de pixel de 30 e 90 m. A validacao dos modelos preditores de UM foi realizada com a totalidade dos dados da area. Os atributos do terreno que melhor explicaram a ocorrencia das UM foram elevacao, declividade, comprimento de fluxo e orientacao das vertentes. Os MDEs com tamanho de pixel de 30 m geraram correlacoes solo-paisagem menos acuradas. Os modelos preditores mais acurados e com maior numero de UM estimadas foram os gerados a partir dos MDEs com resolucao espacial de 90 m (SRTM v4.1 e CN90), sendo esses os MDEs mais indicados para o MDS, quando predominarem relevos plano e suave ondulado.
Platelet-like Nanoparticles (PLNs): Engineering Shape, Flexibility and Surface Chemistry of Nanocarriers to Target Vascular Injuries

Abstract Targeted delivery of therapeutic and imaging agents in the vascular compartment represents a significant hurdle in using nanomedicine for treating hemorrhage, thrombosis, and atherosclerosis. While several types of nanoparticles have been developed to meet this goal, their utility is limited by poor circulation, limited margination and minimal targeting. Platelets have an innate ability to marginate to the vascular wall and specifically interact with vascular injury sites. These platelet functions are mediated by their shape, flexibility and complex surface interactions. Inspired by this, we report the design and evaluation of nanoparticles that exhibit platelet-like functions including vascular injury site-directed margination, site-specific adhesion and amplification of hemostatic aggregation. Our nanoparticles mimic four key attributes of platelets: (i) discoidal morphology, (ii) mechanical flexibility, (iii) biophysically and biochemically-mediated aggregation, and (iv) heteromultivalent presentation of ligands that mediate adhesion to both von Willebrand Factor and collagen, and specific binding to activated platelets. Platelet-like nanoparticles (PLNs) exhibit enhanced surface-binding compared to spherical and discoidal counterparts, and site-selective adhesive and platelet-aggregatory properties under physiological flow conditions
Synthesis and evaluation of dialkyl furan‐2,5‐dicarboxylates as plasticizers for PVC

Di(2-ethylhexyl), di(2-octyl), dihexyl, and dibutyl furan-2,5-dicarboxylate were synthesized from furfural and characterized for their plasticizing abilities toward PVC by dynamic mechanical thermal analysis (DMTA) with di(2-ethylhexyl) phthalate (DOP) as the standard of reference. DMTA gave values for the depression of the glass transition temperature (Tg) per mass fraction of plasticizer, and it also yielded a set of parameters, relative to those for DOP, which describe the compatibility of the furan diesters with PVC. The efficiency in lowering Tg as exhibited by di(2-ethylhexyl) furan-2,5-dicarboxylate is similar to that of its benzenoid analog, DOP, and was determined at 2.41 and 2.45°C per mass % plasticizer, respectively. All four furan diesters were found to be more compatible toward PVC than toward DOP, with dibutyl furan-2,5-dicarboxylate the most highly compatible. © 1994 John Wiley & Sons, Inc.
Phase transitions in CuS–Ag2S nanoparticle system

(Ag2)xCu1−xS, x = . 2, . 4, . 6 and . 8 nanoparticles were synthesized by the solvothermal method. The as-synthesized nanoparticles were characterized by X-ray diffraction to study the crystal structure and size. The surface morphologies of the above samples were studied using scanning electron microscope. As there is continuous shift in the lower wavelength absorption edge of the UV–VIS spectrum of these samples with concentration, (Ag2)xCu1−xS nanoparticles can be tuned to different band gap energies by varying the composition. The D.C. electrical resistance was measured in the temperature range 310–485 K. As Ag2S transforms from monoclinic to bcc at around 450 K, copper sulfide nanoparticles also shows a phase transition at around 470 K, the effects of these two transitions are seen in the resistance measurements and in the UV–VIS spectra of the entire system. The electrical resistance of (Ag2)xCu1−xS nanoparticles rapidly reduces as more and more copper sulfide is added.
Optimization of Structures and LJ Parameters of 1-Chloro-1,2,2-trifluorocyclobutane and 1,2-Dichlorohexafluorocyclobutane

The structures and the Lennard-Jones (LJ) parameters of anesthetic 1-chloro-1,2,2-trifluorocyclobutane (F3) and nonimmobilizer 1,2-dichlorohexafluorocyclobutane (F6) were optimized by using ab initio calculations in conjunction with liquid and gas phase molecular dynamics simulations. Geometry optimization of various isomers of F3 and F6 was carried out with MP2/6-311+G(2d,p) that reproduced the experimental pucker angles of the precursors perfluorocyclobutane and cyclobutane more accurately than with B3LYP/6-311+G(2d,p). Frequency calculations were performed to ensure that the optimized structures were at minimums of the potential energy surfaces. The partial atomic charges of F3 and F6 from the Merz−Singh−Kollman MP2/6-311+G(2d,p) calculations and the LJ parameters optimized previously for other halogenated compounds were used to start molecular dynamics simulations. The LJ parameters were then optimized through iterative adjustments to regenerate the heat of vaporization and the densities of F3 and F6 .
Über die Berechnung von Franck-Condon-Integralen

A new method of approach is proposed for the problem of electronic transitions accompanied by the excitation of molecular or crystal vibrations. The Hamiltonian of the normal vibrations is expressed in terms of the so-called creation and annihilation operators, and the change in the equilibrium nuclear distances and vibrational frequencies are represented by transformations which are also expressed in terms of these operators. Calculations are made for some typical cases.
Tilburg University Advice and monitoring in venture finance

This paper studies the advising and monitoring activities of 14 European venture capitalists (VCs) in 74 entrepreneurial firms. We distinguish between VC advising versus monitoring activities based on the congruence versus dissonance with entrepreneurial interests. The data indicate that the allocation of greater cash flow and control rights to the VCs gives rise to more intensive VC advice, but not more intensive monitoring. VC monitoring is attributable to the need for monitoring due to entrepreneurial firm-specific characteristics. The data further indicate a strong effect of portfolio size on both advice and monitoring, consistent with recent theoretical work on the optimal size of VC portfolios. Finally, the data indicate a country’s legality index is closely connected with the propensity for conflicts between entrepreneurs and their investors. The results are robust to the potential for endogeneity, among various other robustness checks.