Miracle-dz/UniFAR-FTUs huggingface dataset:
Determination of aldehydic lipid peroxidation products with dabsylhydrazine by high-performance liquid chromatography

A high-performance liquid chromatographic method has been developed to measure adlehyde products of lipid peroxidation including n-alkanals, trans-2-alkenals, 4-hydroxy-2-nonenal, and malonaldehyde. The chromophoric reagent dabsylhydraue reacts with various aldehydes produced from two different lipid peroxidation model systems: Fe 2+ /H 2 O 2 and Fe 2+ /vitamin C oxidation of arachidonic and linoleic acids, respectively. The formed products were carefully characterized by IR, MS, and NMR spectral analysis and proved to be hydrazone rather than 2-pyrazoline or pyrrole derivatives. EI-MS of all the derivatized straight-chain aldehydes showed a characteristic (M-28) fragment in the spectra with high, consistency. Physicochemical properties including melting points are also described. The detection limits in the range of 11 pmol (5 ng) have been reached by using an NP Octadecyl C 18 reversed-phase column. 4-Hydroxy-2-nonenal and hexanal were found to be the most abundant aldehydes in the lipid peroxidation systems described. The dose-response curve showed great linearity and exhibited good reproducibility of this procedure for quantitative estimation
Colloidal Suspensions of Nanometer‐Sized Mesoporous Silica

Nanometer‐sized surfactant‐templated materials are prepared in the form of stable suspensions of colloidal mesoporous silica (CMS) consisting of discrete, nonaggregated particles with dimensions smaller than 200 nm. A high‐yield synthesis procedure is reported based on a cationic surfactant and low water content that additionally enables the adjustment of the size range of the individual particles between 50 and 100 nm. Particularly, the use of the base triethanolamine (TEA) and the specific reaction conditions result in long‐lived suspensions. Dynamic light scattering reveals narrow particle size distributions in these suspensions. Smooth spherical particles with pores growing from the center to the periphery are observed by using transmission electron microscopy, suggesting a seed‐growth mechanism. The template molecules could be extracted from the nanoscale mesoporous particles via sonication in acidic media. The resulting nanoparticles give rise to type IV adsorption isotherms revealing typical mesopores and additional textural porosity. High surface areas of over 1000 m2 g–1 and large pore volumes of up to 1 mL g–1 are obtained for these extracted samples.
Immobilization of Cadmium and Lead Compound Contaminated Soil Using New Porous Material Combined with Phosphate

The effect of new porous material and its compound treatments with phosphate on immobilization of cadmium and lead in contaminated soil was studied using a pot-culture experiment, and the immobilization mechanism of these amendments was clarified through analysis of heavy metal fractions. The single treatments of porous material could not significantly promote growth of rape, while the compound treatments of porous material and phosphate markedly increased dry biomass of shoots and roots, with maximal increases of 59.8 % and 109.6 %, respectively. The immobilization treatments could significantly reduce Cd and Pb concentrations in shoots, with maximal reductions of 62.7 % and 43.4 %, respectively, and the treatments of porous material combined with phosphate appeared more efficient than the single amendment treatments in reducing Pb uptake by rape. Addition of porous material could markedly decrease soil pH values. The immobilization treatments could significantly decrease concentrations of available Cd and Pb in soils, with maximal reductions of 45.9 % and 46.8 %, respectively, and the compound porous material treatments appeared more effective than the single treatments in reducing availability of Pb. Through special adsorption of chemistry and formation of mineral precipitation, porous material and phosphate could promote transformation of acid-extractable Cd and Pb into residual fraction, resulting in significant reduction of heavy metals' bioavailability and mobility and then fixing remediation of contaminated soil. In summary, the compound treatments of porous material and phosphate are the most effective treatments for immobilization of Cd and Pb in contaminated soils.
Adsorption of metal ions by clays and inorganic solids

This review deals with adsorption of metal ions, particularly those considered as hazardous, on clays and some inorganic solids and covers the publication years 2000–2013 describing and quantifying the use of isotherms to obtain the adsorption capacities of the solids. The inorganic solids in the review include clays and clay minerals, their modified forms (obtained by treatment with acids and alkalis, organic functionalization, etc.), zeolites, silica gel, soil, river sediment, activated alumina, inorganic polymers, red mud, inorganic oxides, fly ash, etc. The use of two parameter and three parameter linear isotherms are only discussed with a view to obtain quantitative description of adsorptive accumulation and separation of metal ions from aqueous solution on the solids. The extensively used isotherms are those of Freundlich, Langmuir, Dubinin–Radushkevich and Redlich–Peterson. How these isotherms are being used to obtain the adsorption capacities along with their interpretations form the bulk of the review. The review is divided into sections, each describing the use of a particular isotherm. The metal cations receiving immense importance in adsorption studies are As(III)/As(V), Cd(II), Cr(III)/Cr(VI), Cu(II), Co(II), Pb(II), Ni(II), Hg(II), and Zn(II), and the review covers both the cationic and the anionic metal ions. A few other cations such as Mn(II), Fe(III), Se(V), which have not received much attention, are also covered.
α‐Adrenoceptor blocking action of aaptamine, a novel marine natural product, in vascular smooth muscle

In the rabbit isolated aorta and renal artery, aaptamine (3 times 10−5 m), a novel heteroaromatic substance isolated from a sea sponge Aaptos aaptos produced a parallel, rightward shift of the dose‐response curve for noradrenaline, whereas that for histamine or KCl was not affected. But, the derivatives of aaptamine, demethylaaptamine, demethyloxyaaptamine, dihydroaaptamine and dihy‐drodemethylaaptamine at concentrations of 10−5 to 10−4 m had no effect on the dose‐response curve for noradrenaline. These results suggest that aaptamine is a competitive antagonist of α‐adrenoceptors in vascular smooth muscles.
Combined effects of dissolved organic material and water hardness on toxicity of cadmium to Daphnia magna

The interaction between dissolved organic material (DOM) and water hardness and their effects on the acute toxicity of cadmium (Cd) to Daphnia magna was studied. At an original hardness (0.1 mmol Ca + Mg per liter) of humic lake water (DOC 19.6 mg/L), Cd was significantly less toxic in the humic than in the reference (DOC < 0.2 mg/L) water. Furthermore, after dilution down to 10% (dissolved organic carbon [DOC] 2.0 mg/L), the humic water still decreased the lethality significantly. The results suggest that the reduced toxicity of Cd in the lake water is due to complexation with DOC. An increase in water hardness (from 0.1 to 0.5 or 2.5 mmol Ca + Mg per liter) decreased the measured binding coefficient of Cd to DOM. In addition, the acute toxicity of Cd decreased, and the difference between the reference and humic water disappeared. As a conclusion, DOM in the soft lake water had a protective effect against Cd toxicity. In hard water, obviously, the added hardness cations, especially Ca2+, effectively competed with Cd2+ for available binding sites in DOM. Simultaneously, Ca2+ ions interfered also with the uptake of Cd2+ either by competing in transport through cell membranes or by reducing membrane permeability.
New Model for the Study of Liquid–Vapor Phase Transitions

A new model is proposed for the study of the liquid–vapor phase transition. The potential energy of a given configuration of N molecules is defined by U(r1, ···, rN) = [W(r1, ···, rN) − Nυ0]e/υ0≤0, where W is the volume covered by N interpenetrating spheres each of volume υ0 and each centered on one molecule, and where e is an arbitrary positive energy. This continuum model proves to have a line of symmetry comparable with those found hitherto only in lattice models. The line is that of the diameter, or mean orthobaric density ρ = 12ρ1 + 12ρg, below the critical point, and continues through the one‐phase region to infinite temperature. The existence of this line allows some of the properties to be obtained explicitly, the most unusual of which is that the diameter has a singularity comparable with that in Cυ; hence the law of the rectilinear diameter is not obeyed. An exact solution of the model is obtained in one dimension, in which there is no phase transition, and a mean‐field solution in three dimensi.
Dehydroxylation and Silanization of the Surfaces of β-Cristobalite Silica: An ab Initio Simulation

Dehydroxylation and silanization processes on the silica surface are studied by ab initio molecular dynamics. The (100) and (111) surfaces of β-cristobalite are used as two possible models of the hydroxylated amorphous surface. The activation energy and latent heat for the dehydroxylation reactions of the (100) surface computed by constrained ab initio molecular dynamics are in reasonable agreement with experimental data on the amorphous surface. Adhesion reactions of silanes are simulated aiming at elucidating the binding mechanism of organosilanes used for instance as silica−polymer coupling agents. The simulation have provided insights on the occurrence of multiple silica−silane bonds and on the role of hydrolization of silane by physisorbed water in the adhesion on the wet surface.
In Situ AFM Measurements of the Expansion of Nanostructured Sn–Co–C Films Reacting with Lithium

The volume changes vs lithium content of nanostructured Sn 1-x-y Co x C y thin films with different compositions have been measured using in situ atomic force microscopy (AFM) experiments. For the films studied, the Co content, x, varied 0.18 < x < 0.5 and the carbon content, y, varied 0 < y < 0.79. In all cases the volume varied linearly with lithium content, and the maximum volume expansion ranged from 142 to 204%, depending on the initial composition, for compositions with y < 0.5. The experimental values have been compared with theoretical estimates calculated based on 8.9 ± 0.5% cm 3 /mol for the alloyed Li atoms as proposed by Obrovac [J. Electrochem. Soc. , 154, A849 (2007)]. The agreement is excellent except for the sample that has y = 0.79, or 79% carbon.
Quantification of polyphosphoinositides using selected ion monitoring electrospray mass spectrometry

Polyphosphoinositides (PIP) and (PIP2) show prominent negative singly and doubly charged deprotonated molecules in electrospray mass spectrometry. These ions can be used for quantification of PIP and PIP2 in the low picomole range, without prior chromatographic separation, using selected ion monitoring and consecutive measurements of the signals from the deprotonated singly charged molecules. The dose response curves for both compounds are linear. In a complex matrix consisting of polar lipids (Folch extract) PIP and PIP2 monitored at m/z 965.4 and 1045.5 (stearoyl and arachidonoyl) were determined in the low picomole range, at a flow rate of 100 mu L/min, Collision-induced decomposition of PIP and PIP2 using a mixture of xenon and argon at 25 eV afforded identical high mass ions formed by loss of a molecule of water from PIP and a phosphate group and a molecule of water from PIP2. The results indicate that polyphosphoinositides, and biologically relevant changes in their concentrations, can be quantified directly in cells and cellular membranes by selected-ion monitoring with electrospray mass spectrometry.
Biomassa e nutrientes em um povoamento de Eucalyptus urophylla x Eucalyptus globulus , em Eldorado do Sul-RS

A estimativa da biomassa e dos nutrientes, em povoamentos de eucaliptos, e importante para a obtencao e definicao de tecnicas que visem a conservacao da capacidade produtiva dos solos. Com isso, o presente estudo teve por objetivo estimar a biomassa acima do solo e os nutrientes nela contidos em um povoamento de Eucalyptus urophylla x Eucalyptus globulus (eucalipto), com dez anos de idade, em Eldorado do Sul-RS. Foram alocadas aleatoriamente quatro parcelas experimentais (35 m x 20 m), onde se realizou o inventario florestal e a definicao das classes diametricas do povoamento (cinco classes). Para cada classe de diâmetro, foram abatidas tres arvores para a quantificacao de biomassa e nutrientes. A quantificacao da biomassa e dos nutrientes do sub-bosque foi realizada por meio da alocacao aleatoria de cinco parcelas de 25 m2 cada. Para a estimativa da biomassa de eucalipto, utilizaram-se equacoes de regressao obtidas pelo procedimento Stepwise. As equacoes obtidas com a analise de regressao apresentaram boa predicao das variaveis analisadas, devido ao alto coeficiente de determinacao ajustado e ao baixo erro padrao das estimativas. A biomassa do eucalipto encontra-se predominantemente alocada no fuste (madeira + casca) com 93,7%. Esses mesmos componentes tambem apresentam os maiores estoques de nutrientes. A biomassa de sub-bosque compreende uma pequena fracao da biomassa acima do solo (1,4%), mas representa 7,0 e 8,6% do nitrogenio e enxofre do estoque total. Os componentes da biomassa apresentaram composicoes quimicas distintas, sendo geralmente maiores nas folhas e casca e menores na biomassa de madeira e galhos. DOI: http://dx.doi. org/10.13086/2316-980x.v01n01a01
Water solubility of regioselectively 2,3-O-substituted carboxymethylcellulose

A series of 2,3-O-carboxymethylcelluloses (CMC's), which are regioselectively substituted at the C-2 and C-3 position, were prepared and their water solubility was examined. It was found that the lower limit for the degree of substitution (DS) value of water-soluble 2,3-O-CMC is about 0.3. This value was almost the same as that of CMC prepared in a slurry of isopropyl alcohol/water with isopropyl chloroacetate and sodium hydroxide, showing that the uniform alkylation is rather important to convert cellulose into water-soluble derivatives.
Kinetic control of a particle by voltage sequence for a nonimpact electrostatic micromanipulation

This letter describes a calculation of a voltage sequence to obtain kinetic control of a particle for nonimpact electrostatic micromanipulation. The system consists of conductive objects: A manipulation probe, a spherical particle, and a substrate plate. The particle, initially adhering to the probe tip, is detached by an applied voltage. The electrostatic force acting on the particle during its movement to the substrate is calculated by a numerical boundary element method. We determine the voltage and time sequence for nonimpact deposition of the particle onto the substrate by considering the total work to the particle. The calculation provides the power source requirements for nonimpact particle deposition.
Catalytic Depolymerization of Microcrystalline Cellulose Accomplished in an Ionic Liquid

Dissolution and depolymerization of cellulose by the action of acid-functionalized ionic liquid catalysts is reported. Depolymerization of microcrystalline cellulose (MCC) was accomplished by utilizing a binary IL system composed of an IL solvent, 1-butyl-3-methyl-1H-imidazolium chloride (C4mim-Cl), capable of cellulose dissolution combined with a homogeneous IL acid catalyst. The sulfonic acid functionalized IL catalysts employed are capable of hydrolyzing glycosidic bonds to yield cellobiose, glucose and that also enabled dehydration reactions producing 5-hydroxymethylfurfural. Viscometry was employed to follow the progress of the depolymerization and follow-on derivatization reactions. Experiments yielded real-time viscosity data of the reaction system which indicated the type and timing of the derivatization processes that occur. Results suggest that viscometric analyses can be a useful methodology to rapidly screen solution/catalyst compositions for desired outcomes.
Labeling of subcellular redox potential with dopamine-conjugated quantum dots

Semiconductor quantum dots (QDs) possess highly reactive electrons and holes after photoexcitation. The energy of these electrons and holes can be deliberately modulated by attaching the QD to an electron donor or acceptor. This eliminates (quenches) QD fluorescence, as well as affecting the ability of the QD to oxidize or reduce common biomolecules such as glutathione and DNA. This greatly alters the fluorescent properties and toxicity of such QDs inside cells. In this work, we show that a specific electron donor, the neurotransmitter dopamine, yields redox-sensitive conjugates when attached to at least some colors of CdSe/ZnS QDs. The potential for the use of such conjugates as sensors, and the implications for enhanced toxicity in such conjugates are discussed.
The failure in agricultural productivity growth in African French speaking countries

This paper examines changes in agricultural productivity in 8 French-speaking countries. The relative performance of agricultural sector was gauged using data envelopment analysis. From a panel data set of the 8 countries, which included the 30-year period 1970-2000, mathematical programming methods were used to measure Malmquist indexes of total factor productivity. It was found that, during that period, total factor productivity have experienced a negative evolution in sample countries. A decomposition of those measures suggest that, most of the weak performance of factors productivity is attributable more to technological change than technical efficiency change. Sample data showed that devaluation of Cfa franc have had a positive impact on the sector. We also found that compared to non-sahelian countries, sahelian countries have experienced a weak performance of their agricultural sector during the period 1970-2000.
Development of a spatial planning support system for agricultural policy analysis: case study Borkhar district, Iran

This study aims developing a model to simulate the reaction of different farm-types to various policy instruments in order to support agricultural planning at regional levels. In this context a linear programming model developed to integrate the socio-economic and the biophysical resources of farmers to assess the immediate effects and the long-term impacts of various policy instruments. This distributed model includes variety of sub-models (Farm-type land unit, farm-type, village, and integrated model). Biophysical inputoutput coefficients of the model (yield, nutrient and water requirement) have been generated spatially by application of crop growth simulation model “CGMS” and GIS techniques for the crops in the district.
Crystal and molecular structure of tri-iodoheptakis(tri-p-fluorophenylphosphine)undecagold

The crystal and molecular structure and the absolute configuration of the title compound have been determined from three-dimensional X-ray data collected by counter methods, and refined by least squares to R 0·034 for 1959 independent reflections. The crystals are in space-group R3, with unit-cell dimensions a= 15·96(2)A, α= 108·4(1)°, and Z= 1. The molecular unit possesses C3 symmetry. The metal-atom cluster derives from a centred icosahedron, in which one triangular face has been substituted by a single gold atom. Au–Au Interactions are: mean centre-to-periphery 2·68 A, peripheral distances 2·836(4)–3·187(3)A, mean 2·98 A. There are three independent classes of Au–P bonds, in the range 2·21(1)–2·29(1)A. The Au–l distances are 2·600(5)A. The packing is discussed with reference to the disordered structure of Au11l3[P(p-ClC6H4)3]7.
Arc-electrode phenomena

The paper gives a survey of the most important aspect of arc-electrode processes (excluding externally heated cathodes) which concern engineers in a variety of applications. Although it is not possible to avoid discussion of the basic mechanisms and of the number of conflicting and still unresolved theories for them, the emphasis is, as far as possible, on those characteristics which affect the design and operation of devices or processes in which they occur. There is a brief general description of arc discharges and of important differences between them and glow discharges. After distinguishing between thermionic and nonthermionic cathodes (and commenting on the transitions of emission type which occur with some metals), the main body of the paper deals with nonthermionic cathodes. This begins with some of the chief observational data, such as current density, root splitting, electrode erosion, magnetic deflection, plasma jets and force on the cathode, and goes on to consider some of the important factors which affect cathode processes, including electrode material and surface state, current, gas and its pressure or vacuum. After commenting on zones within the cathode fall, there is a discussion of the many theories which have been put forward to explain the emission mechanism of cold-cathode arcs. It is suggested that no single process is responsible for all conditions, and that transitions in mode can occur, either abruptly or gradually, and the most significant principles and facts which must be taken into account are outlined. There is a short Section describing the main features of arc anodes, and the paper concludes with a discussion of electrode effects in mercury-arc convertors, gas-blast and oil circuit breakers, vacuum switches, arc heaters and plasma torches, arc welding, commutation and arc furnaces.
Prewavy Pattern: A Director-Modulation Structure in Nematic Liquid Crystals

Abstract A periodic structure (the prewavy pattern) found below the onset of electroconvection in a homeotropically aligned nematic liquid crystal is reported. It is characterized by a periodic modulation of the director in the xy-plane, which can be distinguished from electroconvection patterns with modulation in the xz-plane. The prewavy instability is investigated in detail; a phase diagram in the frequency-voltage plane, the voltage dependence of the azimuthal rotation angle, the voltage and frequency dependence of the wavelength of the prewavy pattern, and the director field in the prewavy pattern are provided. This prewavy pattern always evolves into the so-called chevrons above onset of convection. The wavelength of the chevrons and the orientation of their alternating zig and zag rolls depend on the director structure of the prewavy pattern.
Effects of Surface Chemistry on Structure and Thermodynamics of Water Layers at Solid−Vapor Interfaces†

The effects of surface chemistry on the isotherm thickness and structure of the adsorbed water layer as well as the isosteric heat of adsorption and entropy of adsorption were studied using attenuated total reflection infrared spectroscopy. The degree of hydrophilicity seems to distinctively change the structure and thermodynamic properties of the water layers adsorbed on silicon oxide surfaces. On the highly hydrophilic silicon oxide surface covered with silanol groups, the water layer adsorbed at low humidities exhibits the OH stretching peak at 3230 cm−1 (characteristic of a solid-like water structure), and the isosteric heat of adsorption is much higher than the latent heat of ice sublimation. As the concentration of surface silanol groups decreases, both the initial isosteric heat of adsorption of water and the amount of solid-like water decrease. The water layer adsorbed on the hydrophilic surface at low humidities seems to have much lower entropies than bulk water, while the entropy of the water la.