Miracle-dz/UniFAR-FTUs huggingface dataset:
SIMULTANEOUS EXTRACTION AND ANALYSIS OF FOUR POLYPHENOLS FROM LEAVES OF LYCIUM BARBARUM L.

ABSTRACT Polyphenols are the important active compounds present in the leaves of wild Lycium barbarum L. By liquid chromatography–mass spectrometry, high-performance liquid chromatography and ultraviolet spectra analysis, the main polyphenols in the plant leaves were identified as rutin, chlorogenic acid, quercetin and kaempferol. Microwave-ultrasonic-assisted extraction (M-UAE) and ultrasonic-reflux extraction (URE) of the polyphenols were established in this study. The results showed that M-UAE was suitable for rapid extraction and quantitation of large numbers of samples, while URE was suitable for rapid extraction of massive materials. The simultaneous extraction and analysis of polyphenols from L. barbarum L. leaves by M-UAE were carried out. The effects of several important factors such as microwave pretreatment, ethanol concentration, ultrasonication temperature, the ratio of liquid to solid, and ultrasonication time were optimized. The highest extraction yields of the polyphenols was obtained with ethanol concentration of 70%, microwave preheating to 60C, ultrasonication temperature of 60C, the ratio of liquid to solid of 25 (mL/g), and ultrasonication time of 30 min. The mechanism of M-UAE extraction was investigated and discussed. URE and M-UAE proved to be fast, highly efficient and energy-saving. PRACTICAL APPLICATIONS The four main polyphenols in the leaves of Lycium barbarum were extracted, identified and determined, which presented basis for health protection research on the leaves of L. barbarum. A highly efficient extraction method and apparatus were developed. The ultrasonic-reflux extraction apparatus and microwave-ultrasonic-assisted extraction method both showed great potentials in the extraction of biologically active compounds.
Novel synthetic routes to carbon-nitrogen thin films

New unimolecular carbon-nitride precursors such as C{sub 3}N{sub 3}F{sub 2}N(SiMe{sub 3}){sub 2} and C{sub 3}N{sub 3}Cl{sub 2}N(SiMe{sub 3}){sub s} were synthesized and used to deposit thin films of composition C{sub 3}N{sub 4}-C{sub 3.2}N{sub 4}, the highest nitrogen content observed in C-N solids. The films were formed by the thermal decomposition of the precursors via elimination of SiMe{sub 3}F and SiMe{sub 3}Cl at 400-500 {degrees}C. Film thicknesses between 1200 and 4000 {Angstrom} were deposited on (100) Si, graphite, beryllium, and SiO{sub 2}, and were extensively characterized for composition and chemical purity using RBS, energy-dispersive X-ray analysis, and SIMS. The material was amorphous as indicated by X-ray diffraction. IR, EELS, and {sub 13}C NMR reveal substantial sp{sup 2} hybridization in both the carbon and the nitrogen. This material should be an excellent precursor for the high-pressure synthesis of C{sub 3}N{sub 4}, the highly sought structural and compositional analog of Si{sub 3}N{sub 4}. 12 refs., 4 figs.
Determination of Arctiin in rat plasma by HPLC method and its application to pharmacokinetic studies

The present study was to investigate the pharmacokinetics of arctiin in male and female rats after oral administration of Fructus arctii. Arctiin (30-70 mg/kg) was orally administered to rats. Blood samples were collected by orbital vein at time intervals after drug administration and the plasma concentrations of the studied components were determined by HPLC after the plasma protein was precipitated directly with acetonitrile. Arctiin was successfully separated using a C18 column with UV detection at 280 nm and a mobile phase of acetonitrile‐water (31:69, v/v) pumped at 1.0 ml/min. The method has a lower limit of quantitation (LOQ) of 0.50 �g/ml for arctiin with the limit of detection (LOD) 0.25 �g/ml, based on a signal-to-noise ratio of 3. The assay was linear over a range 0.50 to 256.50 �g/ml with coefficient of determination greater than 0.99 for analytes. The extraction recoveries was >87%. The method had shown tremendous reproducibility with intra- and inter-day precision <3.2% (RSD), and had proven to be highly reliable for the analysis of plasma samples. The main pharmacokinetic parameters of Arctiin in rats after administration dose range of 30 to 70 mg/kg was processed by Das 2.0, while calculating the pharmacokinetic parameters of one compartment model. From the experimental results, the AUC (area under the concentration-time curve) was not proportional to the administered dose. In the range of the doses examined, the absorption pharmacokinetics of arctiin in rats was based on nonlinear kinetics. The male and female rats on the absorption and elimination of arctiin are different. The female rat’s t1/2 (half life), ke (elimination rate constant), Ka (absorption rate constant), Cmax (peak concentration), Vd (apparent volume), Cl (total body clearance) and AUC of arctiin was significantly higher than the male’s (P < 0.05).
Syntheses of silver nanofilms, nanorods, and nanowires by a microwave-polyol method in the presence of Pt seeds and polyvinylpyrrolidone

AgNO 3 was reduced by ethylene glycol (EG) in the presence of Pt seeds and polyvinylpyrrolidone (PVP) under microwave heating. In addition to spherical nanoparticles, single-crystalline silver nano-films, rods, and wires were produced. The relative number ratio of nanorods and nanowire to the total silver nanostructures was <14%. The formation mechanism of anisotropic silver nanostructures was discussed.
Impact of Pyrolysis Treatment on Heavy Metals in Sediment

This paper describes a laboratory study that examined the effect of pyrolysis treatment on the behavior of Hg, Cr, Zn, Pb, Cu and Cd in a stream sediment. The influences of pyrolysis on the evaporation, sequential extraction and leaching behavior of these metals were investigated. Cr, Zn, Pb and Cu were retained quantitively in the solid residue at temperatures up to 800°C while mercury and cadmium were completely or partially evaporated. The metal form distribution in the sludge samples was determined by the sequential extraction procedure. The procedure revealed that as a consequence of pyrolysis, the metals were more strongly fixed in the treated sediment, as could be seen by the decrease with temperature of the first two sequential-extracted fractions and increase of the residue fraction. The leaching results showed that the quantities of the studied metals leached in the two pyrolysis samples were lower than those in the untreated sediment. The amounts of metals leached from the pyrolysis residues correlated significantly with the first extracted fraction (exchangeable fraction).
Effects of exposure to pulsed 900 MHz electromagnetic fieldsPDFCreator

P. Achermann*, T. Graf *, R. Huber*, N. Kuster**, A.A. Borbély* *Institute of Pharmacology and Toxicology, University of Zürich, CH-8057 Zürich, Switzerland **Foundation for Research on Information Technologies in Society (IT’IS), CH-8045 Zürich, Switzerland (Principal contact: acherman@pharma.unizh.ch) Abstract: Results of two recent studies of the effects of electromagnetic fields (EMF) similar to mobile phones on sleep and the sleep electroencephalogram (EEG) are sum-marized and further research directions are outlined.
Dynamical model of DNA-protein interaction: Effect of protein charge distribution and mechanical properties

The mechanical model based on beads and springs, which we recently proposed to study nonspecific DNA-protein interactions [J. Chem. Phys. 130, 015103 (2009)], was improved by describing proteins as sets of interconnected beads instead of single beads. In this paper, we first compare the results obtained with the updated model with those of the original one and then use it to investigate several aspects of the dynamics of DNA sampling, which could not be accounted for by the original model. These aspects include the effect on the speed of DNA sampling of the regularity and/or randomness of the protein charge distribution, the charge and location of the search site, and the shape and deformability of the protein. We also discuss the efficiency of facilitated diffusion, that is, the extent to which the combination of 1D sliding along the DNA and 3D diffusion in the cell can lead to faster sampling than pure 3D diffusion of the protein.
Comparison of LA-ICP-MS and LA-ICP-OES for the analysis of some elements in fly ashes

In this work quantitative analysis of minor and trace elements in fly ash by nanosecond laser ablation (LA)-ICP-MS and LA-ICP-OES was investigated in terms of detection limits and accuracy. Different binders and modifiers (silver or chromophores) were added to the fly ash powder to prepare mechanically stable pellets and improve sensitivity (signal to concentration ratio). Maleic acid was found to provide a higher degree of homogeneity between sensitivities across the different fly ashes tested. Ashes were from different origins: domestic waste incinerator or ashes from various coal-fired power plants. A calibration procedure using reference materials as standards was employed, the LA-ICP-MS analysis gave an acceptable accuracy (estimated from NIST 1633), better results were obtained using fused bead preparation. The use of the LA-ICP-OES system gave, when possible (higher concentrations), good results in terms of detection limits (1 to 11 µg g−1) and accuracy.
ETUDE DE L’INFLUENCE DES DIFFERENTS PARAMETRES SUR UN MODULE PHOTOVOLTAÏQUE

L’Algerie dispose d’environ 3200 heures d’ensoleillement par annee, beneficiant d’une situation climatique favorable a l’application des techniques solaires. La conception des installations efficaces et rentables sur la base des modules solaires est particulierement importante. Des logiciels dedies a la simulation des systemes photovoltaiques peuvent realiser une vaste et precise analyse, mais ils ne permettent generalement pas a l'utilisateur de modifier les algorithmes. Dans le present travail, un programme fonctionnant en environnement MATLAB, de la simulation de l'application d'un systeme photovoltaique sur la base des modeles mathematiques, de ses composants a ete concu, nous avons modelise un generateur photovoltaique en se basant sur les equations electriques et mathematiques qui regissent son comportement ainsi que la degradation des caracteristiques de ce generateur en fonction des conditions meteorologiques (temperature et eclairement). Nous avons realise notre etude sur le module SPR 315 E de chez SUNPOWER, qui fournit une puissance de 315 W.
Resonant RF network antennas for large-area and large-volume inductively coupled plasma sources

Large-area and large-volume radio frequency (RF) plasmas are produced by different arrangements of an elementary electrical mesh consisting of two conductors interconnected by a capacitor at each end. The obtained cylindrical and planar RF networks are resonant and generate very high RF currents. The input impedance of such RF networks shows the behaviour of an RLC parallel resonance equivalent circuit. The real impedance at the resonance frequency is of great advantage for power matching compared with conventional inductive devices. Changes in the RLC equivalent circuit during the observed E–H transition will allow future interpretation of the plasma–antenna coupling. Furthermore, high power transfer efficiencies are found during inductively coupled plasma (ICP) operation. For the planar RF antenna network it is shown that the E–H transition occurs simultaneously over the entire antenna. The underlying physics of these discharges induced by the resonant RF network antenna is found to be identical to that of the conventional ICP devices described in the literature. The resonant RF network antenna is a new versatile plasma source, which can be adapted to applications in industry and research.
Evolution of organoleptic water quality during treatment in Macao

Abstract In order to improve the drinking water quality, the organoleptic problems were studied in Macao. An analytical and statistical approach permits to identify some organic compounds responsible for the tastes and odours. In the test of pilot plant, a treatment of ozonation coupled with a filtration on GAC eliminates efficiently the musty and earthy descriptors and organic compounds. In Macao, a high concentration of chlorine used in final disinfection may mask some tastes present in water. The experiments performed in reference water (Evian) and sand filtered water of treatment plant show that the chlorine masks certain tastes such as the musty taste produced by the 2‐methylisoborneol (MIB).
Fabrication of strained Si on an ultrathin SiGe-on-insulator virtual substrate with a high-Ge fraction

A promising fabrication method for a Si1−xGex-on-insulator (SGOI) virtual substrate and evaluation of strain in the Si layer on this SGOI substrate are presented. A 9-nm-thick SGOI layer with x=0.56 was formed by dry oxidation after epitaxial growth of Si0.92Ge0. 08 on a silicon-on-insulator substrate. During the oxidation, Ge atoms were rejected from the surface oxide layer and condensed in the remaining SGOI layer, which was partially relaxed without introducing a significant amount of dislocations. It is found from the analysis of the Raman spectra that the strained Si layer grown on the SGOI layer involves a tensile strain of 1%. This strained Si on the SGOI structure is applicable to sub-100-nm metal–oxide–semiconductor field-effect transistors.
ELIMINATING LISTERIA MONOCYTOGENES IN PACKED READY-TO-EAT POULTRY PRODUCTS BY COMBINING IN-PACKAGE PASTEURIZATION WITH NISIN AND/OR LYSOZYME

Listeria monocytogenes is a significant food-borne pathogen particularly associated with ready-to-eat (RTE) meat and poultry products which can grow and multiply at refrigeration temperatures. In-package pasteurization is an effective post-lethality intervention to reduce microbial contamination of RTE meat products. Enhancing the efficiency of in-package pasteurization is vital in reducing the L. monocytogenes population as well as in preserving the quality of the meat product. The first section of the dissertation research evaluated the effect of product thickness on the surface heating rate and final surface temperature during in-package pasteurization of vacuum-packaged bologna. Three thicknesses (4, 12, and 20 mm), corresponding to 1, 3, and 5 slices of two types of bologna having different (13 and 18%) fat contents were subjected to in-package pasteurization at 4 temperatures (60, 70, 80, and 90°C). Surface heating rate was fastest in the thinnest (4 mm) and slowest in the thickest (20mm) samples for all 4 temperatures. Final surface temperature attained after 3 min was lower with increased thickness levels for all temperatures. More significant was the magnitude of the difference in the time required to attain a 5 log reductions in L. monocytogenes on the surface of bologna due to small difference in thickness. A difference of only 16 mm increased the time from 1.5 min to 9.5 min and 0.72 min to 4.12 min at 70 and 80°C, respectively. Effect of surface application of nisin and/or lysozyme (5000 AU nisin/ml, 80 AU lysozyme/ml, and 5000 AU nisin + 80 AU lysozyme/ml) in combination with in-package pasteurization (60, 62.5 and 65°C) of RTE low fat turkey bologna on the inactivation of
Efficient regioselective acylation of 1-β-D-arabinofuranosylcytosine catalyzed by lipase in ionic liquid containing systems

Seven ionic liquids (ILs) were tested for use in the regioselective acylation of 1-β-D-arabinofuranosylcytosine (ara-C) by vinyl propionate, catalyzed by immobilized Candida antarctica lipase B. The results demonstrated that the nature of both the cations and the anions of ILs had a significant effect on the initial rate and the substrate conversion, but little effect on the regioselectivity of the reaction. The lipase displayed enhanced activity toward ara-C when the alkyl chain of CnMIm·BF4 increased in length (n = 4–8) and no acylation reaction occurred in C4MIm·Cl or C4MIm·Br. To further enhance the initial rate and substrate conversion, co-solvent mixtures of ILs and organic solvents were investigated. Among various IL-containing systems examined, 10% (v/v) C4MIm·PF6–tetrahydrofuran gave the highest initial rate and substrate conversion. In this reaction medium, the optimal water activity, vinyl propionate/ara-C molar ratio, temperature and shaking rate were 0.07, 15 ∶ 1 (mol/mol), 60 °C and 250 rpm, respectively. Under these conditions, the initial rate, substrate conversion and the regioselectivity were 94.0 mM h−1, 98.5% and 99%, respectively. An additional comparative study demonstrated that the enzymatic acylation proceeded with very similar initial rate, substrate conversion, regioselectivity and activation energy whether the reaction medium was 10% (v/v) C4MIm·PF6–tetrahydrofuran or 28% (v/v) hexane–pyridine (the best organic solvent mixture for the reaction). However, the lipase exhibited a much higher stability in the IL-containing system, which may also have environmental advantages. The product of the lipase-catalysed reaction was characterized by NMR, FT-IR spectroscopy and was shown to be the 5′-O-monoester of ara-C.
Microscopic investigation and modeling of microtubule self-organization in tubulin solutions

of “Microscopic Investigation and Modeling of Microtubule Self-Organization in Tubulin Solutions” by Yongxing Guo, Ph.D., Brown University, May, 2008. We investigated the microscopic structure and properties of microtubule (MT) striped patterns that spontaneously form in polymerizing tubulin solutions and propose a mechanism driving this assembly. Microscopic observations reveal that the pattern comprises wave-like MT bundles. The retardance of the solution and the fluorescence intensity of labeled MTs vary periodically in space, suggesting a coincident periodic variation in MT alignment and density. This wave-like structure forms through the development and coordinated buckling of initially aligned MT bundles. Both a static magnetic field and convective flow can induce the initial alignment. The nesting of the buckled MT bundles gives rise to density variations that are in quantitative accord with the data. We propose a mechanical buckling model for the spontaneous formation of the striated MT pattern. It describes the buckling of a single MT bundle within an elastic network formed by other similarly aligned and buckling bundles and unaligned MTs. Phase contrast and polarization microscopy studies of the temporal evolution of the pattern imply that the polymerization of MTs within the bundles creates the driving compressional force. Using the measured rate of buckling, the established MT forcevelocity curve and the pattern wavelength, we obtain reasonable estimates for the MT bundle bending rigidity and the elastic constant of the network. We also studied the effects of Polyethylene Glycol (PEG, MW=35 kDa) on MT bundling and pattern formation. We found that with increasing PEG concentrations, MT solutions form progressively weaker patterns. At a sufficiently high PEG concentration (∼0.5% w/w), the samples maintain a nearly uniform birefringence (i.e. no pattern) and laterally contract at a later stage. Concomitantly, on a microscopic level, the network of dispersed MTs that accompany the bundles in pure solutions disappear and the bundles become more distinct. We attribute the weakening of the pattern to the loss of the dispersed MT network, which is required to mediate the coordination of bundle buckling. We propose that the loss of the dispersed network and the enhanced bundling result from PEG associated osmotic forces that drive MTs together and osmotic torques that facilitate their bundling. Similarly, we attribute the lateral contraction of the samples to osmotic torques that tend to align crossing bundles in the network. © Copyright 2008 by Yongxing Guo This dissertation by Yongxing Guo is accepted in its present form by the Department of Physics as satisfying the dissertation requirement for the degree of Doctor of Philosophy. Date James M. Valles Jr., Director Recommended to the Graduate Council Date Thomas Powers, Reader Date Jay X. Tang, Reader Approved by the Graduate Council Date Sheila Bonde Dean of the Graduate School
Thermal Degradation Kinetics of some Aromatic Poly(1,3,4-oxadiazole-ether)s

Poly(1,3,4-oxadiazole-ether)s containing isopropylidene, hexafluoroisopropylidene, cyclohexylidene, fluorene, phthalide or phenylquinoxaline groups have been prepared by nucleophilic substitution polymerization technique of 2,5-bis( p-fluorophenyl)-1,3,4-oxadiazole with various aromatic bisphenols. The thermal decomposition behavior of the polymers was studied using thermogravimetric analysis in air, at several heating rates: 6, 10 and 14° C min . The polymers showed high thermo-oxidative stability with decomposition temperature corresponding to 5% weight loss above 380°C. The kinetic processing of data was carried out using the Coats—Redfern, Reich—Levi, Flyn—Wall and Kissinger methods.
Modification of polyester fabric properties by surfactant-aided surface polymerization

Poly(methyl methacrylate) (PMMA) was applied to polyester fabric using a surface analog of emulsion polymerization. The admicellar polymerization was carried out using 1.5 mM dodecylbenzenesulfonic acid (DBSA) at pH 4 with 0.15M NaCl, 1 : 8 DBSA:monomer, and 1 : 10 initiator:monomer molar ratio. The PMMA film, which was formed, was characterized by SEM and FTIR. Hydrolysis of the PMMA film on polyester fabric was carried out to introduce carboxylic acid groups to the polyester surface to increase its hydrophilicity. The results show that a PMMA thin film was successfully formed on the polyester fabric. The water contact angle of the PMMA-coated polyester fabric after hydrolysis by 10M H2SO4 for 5 h was reduced from 117.3° to 0° and there was a significant increase in the moisture-regain value of the treated fabric. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4059–4064, 2007
Determination of the Herbicide Fluometuron by Photo‐induced Chemiluminescence in a Continuous‐flow Multicommutation Assembly

Abstract This study was dealing with the chemiluminometric determination of the selective herbicide Fluometuron or 1,1‐dimethyl‐3‐(α,α,α‐trifluoro‐m‐tolyl)urea, (C10H11F3N2O) with a molecular weight 232.29 belongs to the phenyl urea herbicides family. The analytical strategy is based on the continuous‐flow manifold, multicommutation and the analyte pre‐treatment, the photo‐degradation. The optimization of chemical (pH, medium, temperature, and organized media) and hydrodynamic parameters (volume of reagents and flow rate) was performed by univariant and multiparametric simplex procedure respectively. Analytical figures of merit and the effect of foreign substances were studied. The method resulted in quick, automated cost‐effective and clean procedure to determine the herbicide in spiked different samples of water and a formulation.