Miracle-dz/UniFAR-FTUs huggingface dataset:
Influence of solvents on the formation of ultrathin uniform poly(vinyl pyrrolidone) nanofibers with electrospinning

Although there have been many reports on the preparation and applica- tions of various polymer nanofibers with the electrospinning technique, the under- standing of synthetic parameters in electrospinning remains limited. In this article, we investigate experimentally the influence of solvents on the morphology of the poly(vinyl pyrrolidone) (PVP) micro/nanofibers prepared by electrospinning PVP solution in dif- ferent solvents, including ethanol, dichloromethane (MC) and N,N-dimethylformamide (DMF). Using 4 wt % PVP solutions, the PVP fibers prepared from MC and DMF solvents had a shape like a bead-on-a-string. In contrast, smooth PVP nanofibers were obtained with ethanol as a solvent although the size distribution of the fibers was somewhat broadened. In an effort to prepare PVP nanofibers with small diameters and narrow size distributions, we developed a strategy of using mixed solvents. The exper- imental results showed that when the ratio of DMF to ethanol was 50:50 (w/w), regular cylindrical PVP nanofibers with a diameter of 20 nm were successfully prepared. The formation of these thinnest nanofibers could be attributed to the combined effects of ethanol and DMF solvents that optimize the solution viscosity and charge density of the polymer jet. In addition, an interesting helical-shaped fiber was obtained from 20 wt % PVP solution in a 50:50 (w/w) mixed ethanol/DMF solvent. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3721-3726, 2004
Initiating free radical polymerization

The kinetics and mechanism of the initiation and reinitiation of free radical polymerization is reviewed. The importance of understanding the kinetics, specificity and efficiency of initiation and chain transfer when predicting polymerization kinetics and polymer composition is highlighted. These factors are particularly important when making low molecular weight polymers and in living or controlled polymerization processes. Examples of RAFT polymerization and catalytic chain transfer are provided.
Synthesis of tetrahexahedral gold nanocrystals with high-index facets

Tetrahexahedral (THH) gold nanocrystals bound to 24 high-index facets were synthesized through a facile colloidal chemistry by reducing HAuCl4 in the mixture solution of N,N-dimethylformamide and poly(vinylpyrrolidone) at 80 °C. As-synthesized THH gold nanocrystals with Oh symmetry were single-crystals, mainly bound to 24 high-index {210} facets. The controlled slow reaction condition made the rhombic dodecahedral gold nanocrystals transform to THH gold nanocrystals with high-index facets.
A mass spectrometry method for quantitative and kinetic analysis of gas release from nuclear materials and its application to helium desorption from UO2 and fission gas release from irradiated fuel

A new system has been developed to determine absolute quantities of gas (mainly noble gases) released during thermal desorption in the range from 10−12 to 10−5 mol with a precision of few percent. The system is actually designed for simultaneous measurement of gaseous elements like He, Xe, Kr, thermally released from nuclear fuel samples and also allows the determination of the release kinetics as a function of time. This system, called Quantitative GAs MEasurement System (Q-GAMES), is based on the principle of collecting, purifying and spiking the sample gas in a “high-pressure” chamber, and continuous sampling of the gas for mass spectrometric analysis without sample depletion during the experiment. It is equipped with its own spike generator and with different gas purification systems. It is shown that this system fulfills the requirement to work with two existing very high-temperature gas desorption facilities for nuclear materials. This paper describes the Q-GAMES principle, the spiking system, its calibration, its operative mode, the different quantification techniques, as well as its technical data, in combination with some examples of typical application.
Oligomerization of Isobutene Catalyzed by Iron(III) Chloride Ionic Liquids

The oligomerization of isobutene catalyzed by ionic liquids containing FeCl4− and Fe2Cl7− was conducted in an autoclave. The conversion of isobutene was above 83 wt%, and the selectivity of diisobutene plus triisobutene was above 75% when the mole ratio of FeCl3 to [(C2H5)3NH]Cl ranged from 1.2:1 to 2:1. The addition of cuprous chloride to the ionic liquid increased the conversion of isobutene and the selectivity of diisobutene plus triisobutene. The latter reached 90% at the mole ratio of CuCl to [(C2H5)3NH]Cl-1.5FeCl3 of 0.25:1. The reaction pathway of the oligomerization of isobutene catalyzed by iron(III) chloride ionic liquids was explained by the carbonium ion mechanism.
Ferroelectricity of polymers based on vinylidene fluoride

Characteristics of the ferroelectricity in polyvinylidene fluoride (PVDF) and copolymers based on vinylidene fluoride (VDF) with different previous thermomechanical histories are analysed. Switching of polarisation and the fluctuation mechanism of formation of new nuclei upon the appearance of conformation defects such as kink bonds are considered. The role of the space charge, which stabilises the new polarisation position, is noted. It is shown that the Curie transition can be either a first- or second-order phase transition depending on the copolymer composition. The influence of the morphology of PVDF on some ferroelectric characteristics is found. In particular, the morphology of thick lamellar crystals is favourable for enhanced spontaneous polarisation. It is shown that a ferroelectric structure approaching the texture of an ideal single crystal can be created in Langmuir–Blodgett films. As the number of unimolecular layers decreases, the concentration of conformational defects in these films increases and the crystallographic order in the lattice is violated. This intensifies the low-temperature Curie transition. The bibliography includes 247 references.
Release behavior of thin-walled microcapsules composed of polyelectrolyte multilayers.

The release properties of the fluorescent probe pyrene, PYR, encapsulated in polyelectrolyte multilayer capsules were examined by fluorescence spectroscopy. PYR was encapsulated by the layer-by-layer deposition of oppositely charged polyelectrolytes onto PYR microcrystal templates, and its release was accomplished by exposing the polyelectrolyte-coated microcrystals to ethanol solutions. Solubilization of the hydrophobic probe by ethanol resulted in its expulsion from the core through the permeable polyelectrolyte multilayer shells. The PYR release rate, quantified by following the monomer fluorescence of the solubilized PYR as a function of time, decreased with increasing number of polyelectrolyte layers deposited onto the microcrystal cores. In addition, two amphiphiles (sodium dodecyl sulfate and dipalmitoyl-dl-α-phosphatidylcholine) used to disperse the microcrystals in aqueous solution prior to coating with polyelectrolytes significantly influenced the PYR release rate. The maximum release time, defi.
Measurement of hydroxyl and hydroperoxy radical uptake coefficients on water and sulfuric acid surfaces

A wetted wall flow tube reactor was used to measure the uptake coefficients, γ, of OH and HO 2 on pure water at 275 K and 28% w/w sulfuric acid at 249 K. The uptake coefficients are lower limits to the mass accommodation coefficients, α, and the γ were determined to be 0.0035 for OH and >0.01 for HO 2 on liquid water and >0.08 for OH and >0.05 for HO 2 on the sulfuric and solution. In addition, the binary diffusion coefficients for HO 2 and OH in water vapor were estimated to be 79±8 and 116±20 Torr cm 2 s -1 , respectively, at 275 K
Estimating (combinations of) Activated Sludge Model No. 1 parameters and components by respirometry

The paper presents a concise overview of respirometric experiments for the calibration of ASM1. First, the popularity of respirometry is explained by its historical impact and its sensitivity and robustness. The body of the text consists of a systematic overview of existing methods for assessment of nearly all ASM1: (i) component concentrations in sludge and waste water; and (ii) biokinetic and stoichiometric parameters. Real-life examples illustrate the methods. A difference is made between direct methods that use explicit calculations and optimisation methods that require numerical optimisation algorithms. It is stressed that the latter approach is especially useful to extract multiple parameters and component concentrations from single respirometric experiments. Finally, the importance of reflecting on the translation of lab-scale respirometric results to a full-scale model is stressed.
Using Molecular Dynamics To Simulate Electronic Spin Resonance Spectra of T4 Lysozyme

The stochastic Liouville formalism (SLE) allows for electronic spin resonance (ESR) spectra to be computed for proteins and lipids, using a stochastic model for the motion of the nitroxide spin probe. The present work reports a molecular dynamics (MD) study of spin-labeled T4 lysozyme, where information extracted from the atomically detailed trajectories is used within the framework of the Liouville equation. Sets of 10 MD trajectories, with two force fields, were produced for each of the T4 mutants N40C and K48C, previously used in ESR experiments. Fluctuations of the local relevant degrees of freedom, order parameters for the spin probe, free induction decay profiles, and finally high-field ESR line shapes were calculated for the two proteins. Sampling probabilities for the nitroxide rotational degrees of freedom are in agreement with the traditional model of Brownian rotational diffusion in a restricting potential. Present results suggest that improved sampling (longer time scale, more averaging over i.
A comparative study of the evolution of blood and hematopoietic cancers in agricultural and industrial zones in the Valencian community (Spain)

An important increase in the frequency of cancer has been observed throughout the industrialized world since the turn of the century attributable not only to an increase in the number of cases diagnosed and to a greater life expectancy, but also to the effects of a series of environmental and life style factors. Based on the categories of blood and hematopoietic cancers corresponding to references 200–208 of the IX Revision of the International Classification of Diseases (ICD), we have carried out a comparative study of the evolution of mortality due to these tumors in the Valencian Community. Four zones were selected: two clearly agricultural and two with a marked industrial activity. Mortality data were obtained from statistics published by the regional healthcare authorities, corresponding to age and sex groups and information was collected on the period 1976–1992. We calculated Mortality Rates per 100000 inhabitants, followed by their standardization by the direct method. The Mean Standardized Mortality Rates (MSMR) were also calculated and we determined the Period Percentage Increment (PPI) and the Annual Percentage Increment (API). Finally, the Standardized Mortality Rates (SMR) were subjected to linear regression analysis (Poisson regression) and a statistical significance test was applied to each of the above mentioned calculations. In all cases MSMR were higher among males than in females. Moreover, the MSMR corresponding to 1987–1992 were higher than in the 1976–1980, both in males and females, and in the total population. Blood and hematopoietic cancers mortality exhibited an increasing tendency throughout the study period and, the rising tendencies were statistically significant. We may conclude that the rising tendency cannot be attributed to any single cause and that measures should be investigated and adopted to control the consequences of this increased use of certain substances.
In vitro gene expression and enzyme catalysis in bio-inorganic protocells

Silica nanoparticles with a balance of hydrophilic and hydrophobic surface properties exhibit surfactant-like behaviour, and as a consequence can strongly adsorb at oil/water interfaces to stabilize the formation of water micro-droplets. Here we exploit this strategy to construct a model of a primitive bio-inorganic protocell, which unlike conventional paradigms based on self-assembled vesicles, is structurally delineated by a porous inorganic membrane rather than a lipid-based bilayer. As proof-of-principle we show that the nanoparticle-stabilized droplets (colloidosomes) can support a range of functionally active biomolecules and bio-machinery related to metabolic and informational processing. Specifically, we demonstrate that the rate of cell-free in vitrogene expression of enhanced green fluorescent protein (eGFP) is essentially the same within the colloidosome interior as in bulk aqueous solution. In addition, we report considerable enhancements in the specific activity of enzymes such as lipoprotein lipase, chymotrypsin or alkaline phosphatase when entrapped within the nanoparticle-stabilized water droplets. Our results suggest that artificial protocells based on the construction of biological/inorganic nanoscale components could have considerable potential in areas such as synthetic biology and bionanotechnology. In a wider perspective, studies on bio-inorganic protocells could provide alternative models for evaluating potential prebiotic pathways prior to the emergence of lipid-based compartmentalization on the early Earth.
Energy Concept for Predicting Hydraulic Jump Aeration Efficiency

Hydraulic jumps, plunging jets and stepped channels are generally used as energy dissipators and self-aerators. Accordingly, it is expected to find a positive correlation between the aeration efficiency and energy dissipation. For this purpose, hydraulic jump self-aeration efficiency has been investigated with the function of energy dissipation rate per unit width. The hydraulic jump data revealed a positive linear relationship between the aeration efficiency and energy dissipation rate. This new procedure could have practical implications for predicting hydraulic jump aeration efficiency.
Peer-to-peer simulation frameworks: a survey

Peer-to-peer (p2p) protocols, like all distributed protocols, are complex, and therefore harder to debug and study in the wild. This is more true of existing p2p protocols, where changing the behaviour of the protocol --- however minor the change may be --- may result in unknown manifestations on the dynamics of the swarm using that protocol. In lieu of the unintended consequences of perturbing a live swarm, researchers have resorted to simulation frameworks. However, simulation results obtained from one simulator are often hard to reproduce when using another simulation framework. This document surveys existing simulator frameworks prevalent in simulating p2p protocols today in order to quantify any assumptions and characteristics inherent in the simulator. This, we hope, will aid future researchers in choosing the right simulation framework for their abstraction.
Electrospinning of functional materials for biomedicine and tissue engineering

Published data on nanostructured materials prepared by electrospinning are analyzed and generalized. Particular attention is devoted to the design and properties of nanocomposite fibrous materials and methods for modification and functionalization of fibre surface. The prospects for the application of non-woven materials for biotissue engineering and for the development of smart materials are considered. The bibliography includes 330 references.
JUICE EXTRACTION FOR TOTAL SOLUBLE SOLIDS CONTENT DETERMINATION IN MELON

- The total soluble solids content (TSSC) shows high positive correlation with sugars content, and therefore is generally accepted as an important quality trait of fruits. In melon, this evaluation is usually done by grinding a slice of the fruit’s pulp in a household food processor, straining the ground material and then proceeding the TSSC determination in the resulting juice. This evaluation is labor-intensive and takes a long time to complete. An alternative process was delineated for obtaining the juice: the pulp of the fruit slice would be transversally cut one or more times, and longitudinally pressed by hand to obtain the juice. The objective of this work was to compare processes for obtaining juice to evaluate TSSC in melons. Fifty, 15, and 15 fruits of the Galia, Yellow, and Cantaloupe type melons were evaluated, respectively. Each fruit was considered as a block, and was longitudinally split into six fractions with similar sizes, which corresponded to the plots. The following treatments were evaluated: fraction without cuts, fractions with one, three, five, or seven transversal cuts, and the fraction treated by the conventional process. It was concluded that the procedure by which the melon slices of Galia, Yellow and Cantaloupe types are pressed for obtaining the juice to evaluate TSSC can overestimate this content. This would probably be due to the fact that the most internal section of the mesocarp presents greater TSSC than the portions closer to the epicarp.
Efficient Room-Temperature Oxidation of Hydrocarbons Mediated by Tricopper Cluster Complexes with Di

Six tricopper cluster complexes of the type [CuICuICuI(L)]1+ supported by a series of multidentate ligands (L) have been developed as oxidation catalysts. These complexes are capable of mediating the facile oxygen-atom transfer to hydrocarbon substrates like cyclohexane, benzene, and styrene (C6H12, C6H6 and C8H8) upon activation by hydrogen peroxide at room temperature. The processes are catalytic with high turnover frequencies (TOF), efficiently oxidizing the substrates to their corresponding alcohols, aldehydes, and ketones in moderate to high yields. The catalysts are robust with turnover numbers (TON) limited only by the availability of hydrogen peroxide used to drive the catalytic turnover. The TON is independent of the substrate concentration and the TOF depends linearly on the hydrogen peroxide concentration when the oxidation of the substrate mediated by the activated tricopper complex is rapid. At low substrate concentrations, the catalytic system exhibits abortive cycling resulting from competing reduction of the activated catalyst by hydrogen peroxide. This behaviour of the system is consistent with activation of the tricopper complex by hydrogen peroxide to generate a strong oxidizing intermediate capable of a facile direct “oxygen-atom” transfer to the substrate upon formation of a transient complex between the activated catalyst and the substrate. Some substrate specificity has also been noted by varying the ligand design. These properties of the tricopper catalyst are characteristic of many enzyme systems, such as cytochrome P450, which participate in biological oxidations.
Optimization of Microwave‐Assisted Extraction of Flavonoid from Radix Astragali using Response Surface Methodology

Abstract Response surface methodology (RSM) was applied to predict optimum conditions for microwave‐assisted extraction (MAE) of flavonoid from Radix Astragali. A central composite design was used to monitor the effect of temperature, extraction time, solvent‐to‐material ratio, and the ethanol concentration on yield of total flavanoid (TFA). Optimum extraction conditions were predicted as 108.2°C, 26.7 min, 23.1 ml/g solvent‐to‐material ratio and 86.2% ethanol. The maximum yield 1.234±0.031 mg/g was close to the yield of Soxhlet and higher than that of ultrasound assisted extraction and heat reflux extraction. MAE was an effective alternative to conventional extraction methods.
Copper and Zinc Enrichment in Different Size Fractions of Organic Matter from Polluted Soils

Bioavailability of heavy metals in soil organic matter depends on its components. Characterization of heavy metal distributions in different fractions of soil organic matter is needed for better understanding of the fate of heavy metals. This study investigated the accumulation and partitioning of copper and zinc among different size particulate organic matter (POM) fractions in polluted soils from a former iron ore processing site in western Shaoxing County, Zhejiang Province. Physical fractionations were carried out to separate soil primary particles according to their size and density. Copper and Zn had a heterogeneous distribution among soil particle fractions. Copper and Zn were significantly (p ＜ 0.05) enriched in the POM fractions. ＞ 0.05 mm POM and ＜ 0.05 mm fine soil fractions were mainly responsible for Cu and Zn retention in soils. The POM fraction contained up to 1 322 mg Cu kg-1 and 1 115 mg Zn kg-1 and the fine soil fraction contained up to 422 mg Cu kg-1 and 537 mg Zn kg-1. The total POM fraction was responsible for 15.8%-41.2% and 12.2%-31.7% of the total amount of Cu and Zn, respectively, in the polluted soils. The percentages of Cu and Zn associated with organic matter in ＜ 0.05 mm fine soil fractions for the polluted soils ranged from 14.1% to 24.5%, and 5.4% to 15.8%, respectively. Accumulation of soil organic matter could increase enrichment of Gu (or Zn) in the POM fractions. Also, Cu provided a greater enrichment in the POM fractions than Zn.
Response to High Temperature in Flag Leaves of Super High-Yielding Rice Pei’ai 64S/E32 and Liangyoupeijiu

Two newly bred hybrid rice combinations, super high-yielding Liangyoupeijiu (Pei'ai 64S×9311) and Pei'ai 64S/E32 (Pei'ai 64S×E32) were used to investigate the photosynthetic characteristics under high temperature in comparison with hybrid rice Shangyou 63. High temperature caused a decreased photosynthetic efficiency and aggravated photoinhibition. The optimum temperature for photosynthetic electron transportation and photosynthetic CO2 fixation were about 28℃ and 35-40℃ respectively. Linear electron transportation is more sensitive to high temperature than the photochemical process. The mechanism of high temperature adaptation was possibly as follows: super high-yielding rice has quickly increasing carotenoid, which acted as a more favorable antioxidant system to reduce the active oxygen production and avoid damage to the photosynthesis system; super high-yielding rice has a higher efficiency of xanthophylls cycle to dissipate excess heat energy; super high-yielding rice has a more stable photosynthetic function, higher photosynthetic efficiency and more heat stable protein content.
Synthesis and Antitumor Activity of Novel 2-(Thymin-1 ′ -ylmethoxy)ethyl Alkyl Sulfides and Their Oxidation Products

A series of novel 2-(thymin-1′-ylmethoxy)ethyl alkyl sulfides have been synthesized in three steps from thymine. They have been oxidized into sulfoxide and sulfone derivatives by means of NaIO 4 and H 2 O 2 30%/diethyl azodicarboxylate (DEAD), respectively, in high yields. All products were characterized by 1 H NMR and IR spectra and elemental analyses. The preliminary bioassay indicates that the compound 6g exhibited potential antitumor activity.