Miracle-dz/UniFAR-FTUs huggingface dataset:
Amphiphilic star-block copolymers based on a hyperbranched core : Synthesis and supramolecular self-assembly

Novel amphiphilic star-block copolymers, star poly(caprolactone)-block-poly[(2-dimethylamino)ethyl methacrylate] and poly(caprolactone)-block-poly(methacrylic acid), with hyperbranched poly(2-hydroxyethyl methacrylate) (PHEMA–OH) as a core moiety were synthesized and characterized. The star-block copolymers were prepared by a combination of ring-opening polymerization and atom transfer radical polymerization (ATRP). First, hyperbranched PHEMA–OH with 18 hydroxyl end groups on average was used as an initiator for the ring-opening polymerization of e-caprolactone to produce PHEMA–PCL star homopolymers [PHEMA = poly(2-hydroxyethyl methacrylate); PCL = poly(caprolactone)]. Next, the hydroxyl end groups of PHEMA–PCL were converted to 2-bromoesters, and this gave rise to macroinitiator PHEMA–PCL–Br for ATRP. Then, 2-dimethylaminoethyl methacrylate or tert-butyl methacrylate was polymerized from the macroinitiators, and this afforded the star-block copolymers PHEMA–PCL–PDMA [PDMA = poly(2-dimethylaminoethyl methacrylate)] and PHEMA–PCL–PtBMA [PtBMA = poly(tert-butyl methacrylate)]. Characterization by gel permeation chromatography and nuclear magnetic resonance confirmed the expected molecular structure. The hydrolysis of tert-butyl ester groups of the poly(tert-butyl methacrylate) blocks gave the star-block copolymer PHEMA–PCL–PMAA [PMAA = poly(methacrylic acid)]. These amphiphilic star-block copolymers could self-assemble into spherical micelles, as characterized by dynamic light scattering and transmission electron microscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6534–6544, 2005
Theory of non‐Newtonian viscosity and normal stress coefficients of fluids

The evolution equation for the traceless symmetric part P of the stress tensor derived previously for dense simple fluids is further investigated of its applicability to non‐Newtonian fluid behaviors and normal stress effects. Nonlinear differential equations for three independent components of the stress tensor are obtained in the case of a unidirectional flow in an incompressible fluid. The asymptotic stability of the steady state (equilibrium) is studied with linearized equations and the stability conditions are derived. Approximate steady state solutions are calculated from the evolution equations for the three components and viscometric functions are obtained therefrom. By taking the evolution equations as a set of phenomenological evolution equations, we show that it is possible to apply them even to nonsimple fluids such as polymer solutions, by analyzing experimental data on the shear rate dependencies of the viscometric functions of some polymer solutions. We also show that the approximate visco.
Absorption and scattering properties of water body in Taihu Lake, China: backscattering

The HydroScat‐6 spectral backscattering sensor was used to measure in situ the backscattering coefficients at six wavelengths (442, 488, 532, 589, 676, 852 nm) at 67 samples from all over Taihu Lake, China. The measured raw data were corrected with the tested backscattering probabilities of 0.015, 0.019, 0.030 and 0.050. Combined with simulated data by the optimization algorithm, it shows that the backscattering probability (a ratio between backscattering coefficient and scattering coefficient of suspended particulate matter), with a mean of 0.041 (SD 0.030), is wavelength‐dependent and not a constant, and may be expressed as a significant quadratic function of wavelength. The value of backscattering probability can be used to perform the sigma correction for the measured raw data more accurately. Thus, the backscattering may be uncovered as clearly and precisely as possible.
High Molecular Weight Polybenzimidazole Membranes for High Temperature PEMFC

High temperature operation of proton exchange membrane fuel cells under ambient pressure has been achieved by using phosphoric acid doped polybenzimidazole (PBI) membranes. To optimize the membrane and fuel cells, high performance polymers were synthesized of molecular weights from 30 to 94 kDa with good solubility in organic solvents. Membranes fabricated from the polymers were systematically characterized in terms of oxidative stability, acid doping and swelling, conductivity, mechanical strength and fuel cell performance and durability. With increased molecular weights the polymer membranes showed enhanced chemical stability towards radical attacks under the Fenton test, reduced volume swelling upon the acid doping and improved mechanical strength at acid doping levels of as high as about 11 mol H3PO4 per molar repeat polymer unit. The PBI‐78kDa/10.8PA membrane, for example, exhibited tensile strength of 30.3 MPa at room temperature or 7.3 MPa at 130 °C and a proton conductivity of 0.14 S cm–1 at 160 °C. Fuel cell tests with H2 and air at 160 °C showed high open circuit voltage, power density and a low degradation rate of 1.5 μV h–1 at a constant load of 300 mA cm–2.
Statistical mechanics of protein solutions

We study theoretically thermodynamic properties of spherical globular proteins in aqueous solution with added monovalent salt. We show how one can determine an effective interaction potential between the proteins from experimental data as a function of salt concentration and we apply this to the protein lysozyme at a solution pH of 7.5 and ionic strengths between 0.05 M and 2 M. It turns out that apart from steric and electrostatic repulsions, there is also an attractive interaction between the proteins. We then develop a method, which we name the optimized Baxter model (OBM), to determine thermodynamic properties of the protein solution, also at large volume fractions of proteins. We apply this method to predict the osmotic compressibility of the protein solution as a function of protein concentration and we show that the predictions compare fairly well with experimental data of lysozyme at several salt concentrations. Since both the OBM and the effective interaction between the proteins are only approximate, we use the OBM to predict thermodynamic properties of a model system with known interaction potential, and we compare these predictions with results from computer simulations to see how accurate the OBM actually is. We also look at the phase equilibrium between a protein solution and protein crystals. We use the OBM to determine the osmotic pressure and the chemical potential of the solution and we show that one can explain the ionic-strength dependence of the chemical potential with a simple model for the crystal. We apply the same method to crystals of silicotungstate in equilibrium with the solution phase. Finally, we predict the first-order correction in the density of the collective diffusion coefficient and we compare the predictions to experimental results on lysozyme.
Comparing the effectiveness of intranasal Midazolam and intravenous Lorazepam for the treatment of acute seizures in children

Objective: The objective of this study was to compare the safety and efficacy of intranasal midazolam with intravenous lorazepam in acute seizures in children. Methods: Children aged 6 months–12 years with active tonic/clonic/tonic-clonic seizures coming to the pediatric emergency department were enrolled in the study after getting informed consent. Groups were randomly distributed (Group 1: Intranasal midazolam; Group 2: IV lorazepam) and the sample size was 80 (40 in each group). Under clinical and pulse oximetry monitoring, aqueous midazolam 0.2 mg/kg was administered intranasally through automated aqueous intranasal spray(Midacip 0.5mg per puff) in lying down or in 45° propped up position to Group 1, while injectable lorazepam 0.1 mg/kg was administered intravenously slow (to a maximum of 4 mg) to Group 2. Results: Both the groups were found to be comparable in baseline characteristics. Mean time to administer the drug after arrival to the doctor in intranasal midazolam and IV lorazepam was 3.65 (standard deviation [SD] 1.167) min and 7.93 (SD 3.23) min, respectively (p=0.0001). Intranasal midazolam group had significant control of seizures in <5 min of arrival (p=0.0006). The control of seizures within 1 min after drug administration was also found to be more effective in midazolam group (p=0.004). No adverse effects or respiratory depression were found in any of the groups. Conclusion: The ease to administer, effectiveness, and rapid onset of action of intranasal midazolam without causing any respiratory depression enable it to be considered as a first-line drug for acute seizures in all settings including homes/day-care centers.
Application of X-ray computed tomography to soil science: A literature review

The study of the spatial configuration of soil, in its complexity, requires an understanding of the interrelations and interactions between the diverse soil constituents, at various levels of organization. Investigations of the spatial arrangement of the mineral and organic components of soil have benefited from the development of techniques for structural analysis. X-ray computed tomography (CT) is a non-destructive and non-invasive technique that has been successfully used for three-dimensional (3D) examination of soil. Valuable information has been obtained by the application of CT for the description and quantitative measurements of soil structure elements, especially of soil pores and pore network features. In many studies, X-ray CT has been used to investigate the hydro-physical characteristics of the soil, in a functional and temporal manner. A dynamic approach has also been utilized in the evaluation of the biotic factor influence on soil. The analysis of soil solid phases, by X-ray CT, has been c.
3-Hydroxychromone dyes exhibiting excited-state intramolecular proton transfer in water with efficient two-band fluorescence

We demonstrate that newly synthesised 7-acetamido-3-hydroxychromones, as well as their parent 3-hydroxychromone (3HC) analogues, exhibit excited-state intramolecular proton transfer reaction in polar protic media including water, resulting in well-resolved two-band fluorescence. Among all 3HCs reported so far, the new compounds show the highest quantum yields ever reported in water (4–13%), while maintaining the sensitive ratiometric response to solvent polarity. This makes them very promising precursors for the development of two-band fluorescent labels and probes, operating in water and other protic media.
Reactions of Nitridotechnetium(V) Complexes with Boranes

Nitrido bridges between technetium and boron were formed during reactions of [TcN(PMe2Ph)(Et2dtc)2] (Et2dtc− = diethyldithiocarbamate) and BH3 or BPhCl2 at low temperatures. X-Ray structure determinations show that the products contain almost linear Tc–N–B bonds with Tc–N distances which are only slightly lengthened with respect to the triple bonds in the precursor molecule. However, a significant lengthening of the Tc–S bond trans to the nitrido ligand is detected by the decrease of the structural trans influence of “N3−”N. The compounds are instable and decompose at room temperature under cleavage of the N–B bonds. A reaction between [TcNCl2(PPh3)2] and BCl3 does not yield a product with a nitrido bridge. Prolonged heating in dichloromethane results in decomposition of the technetium complex and the formation of (HPPh3)2[TcCl6]. Hydrogen bonds are established between the complex anion and each two counter ions.
Passivation of CdZnTe surfaces by oxidation in low energy atomic oxygen

A method of surface passivation of Cd1−xZnxTe (CZT) x-ray and gamma ray detectors has been established by using microwave-assisted atomic oxygen bombardment. Detector performance is significantly enhanced due to the reduction of surface leakage current. CZT samples were exposed to an atomic oxygen environment at the University of Alabama in Huntsville’s Thermal Atomic Oxygen Facility. This system generates neutral atomic oxygen species with kinetic energies of 0.1–0.2 eV. The surface chemical composition and its morphology modification due to atomic oxygen exposure were studied by x-ray photoelectron spectroscopy and atomic force microscopy and the results were correlated with current-voltage measurements and with room temperature spectral responses to 133Ba and 241Am radiation. A reduction of leakage current by about a factor of 2 is reported, together with significant improvement in the gamma-ray line resolution.
A New Topology of Solutions of Chemical Equations

In this work is induced a new topology of solutions of chemical equations by virtue of point-set topology in an abstract stoichiometrical space. Subgenerators of this topology are the coefficients of chemical reaction. Complex chemical reactions, as those of direct reduction of hematite with a carbon, often exhibit distinct properties which can be interpreted as higher level mathematical structures. Here we used a mathematical model that exploits the stoichiometric structure, which can be seen as a topology too, to derive an algebraic picture of chemical equations. This abstract expression suggests exploring the chemical meaning of topological concept. Topological models at different levels of realism can be used to generate a large number of reaction modifications, with a particular aim to determine their general properties. The more abstract the theory is, the stronger the cognitive power is.
SYNTHESIS AND PHARMACOLOGICAL EVALUATION OF SOME PYRAZOLE DERIVATIVES FOR ANTI-INFLAMMATORY ACTIVITY

This work has been undertaken for the synthesis and pharmacological evaluation of some pyrazole derivatives for anti-inflammatory activity. 3-methyl-1-phenyl-4,5-dihydro-1H-pyrazol-5-one obtained from phenyl hydrazine and ethyl acetoacetate was acetylated and then subjected to Claisen-Schmidt condensation with 4-hydroxy benzaldehyde to get a chalcone. This chalconewas cyclized with the help of hydroxylamine hydrochloride to form an isoxazole derivatives which were further condensed with various substituted aromatic aldehydes to obtain titled compounds (4aD1-4aD15). The structures of new synthesized compounds were confirmed by IR, 1 H NMR and Mass spectral data. Synthesized derivatives were evaluated for their anti-inflammatory activity. The compound 4aD3, 4aD8, 4aD9, 4aD10 and 4aD14was found to have comparable anti-inflammatory activity with that of standard drug indomethacin.
Temperature-Insensitive Microemulsions in a Sucrose Monoalkanoate System

Abstract Middle-phase microemulsion (surfactant phase) is formed in a water/sucrose monododecanoate (SE)/hexanol/decane system. Based on the geometrical relations of a particular three-phase triangle in the quaternary system, the monomeric solubility of hexanol in the excess oil phase and the mixing fraction of SE and hexanol at the water–oil interface inside the microemulsion were obtained. Both values are almost unchanged with increasing temperature. This phase behavior is completely different from that for a system including an ordinary polyoxyethylene-type nonionic surfactant and resembles that in a brine/ionic surfactant/cosurfactant/oil system. On the other hand, the solubilization capability of the SE–hexanol mixtures decreases at higher temperatures due to the decrease in the compatibility of the microemulsion with oil. However, the mixing ratio of mixed surfactant for the maximum solubilization is not greatly changed. Consequently, temperature-insensitive microemulsions can be attained in the present SE system. The effect of oil or surfactant chain length on the phase behavior is also discussed.
The astrochemistry of H3+

The reactions of the molecular ion H3+ are pivotal to the chemistry of dense interstellar clouds. Produced by the cosmic-ray ionization of molecular hydrogen, H3 + reacts with a variety of atoms and molecules to produce species that are precursors to many of the detected molecules in dense clouds. For example, the reaction of H3+ with atomic O leads, eventually, to the production of water, while the reaction with HD leads to the production of a wide variety of deuterated isotopomers. In this article, the chemistry of H3+ and the products derived from it are discussed in the larger context of interstellar chemistry.
Novel single resistance controlled sinusoidal oscillator using FTFN and OTA

A novel single resistance controlled sinusoidal oscillator using one p Four terminal floating nullor (pFTFN) and one Operational transconductance amplifier (OTA) to alongside two resistors and two capacitors, all ground, is presented. It is suitable for IC implementation due to use of grounded capacitors. Simulations results are given to verify the theoretical analysis. The oscillation frequency is adjustable through grounded resistor R1 which can be made voltage variable.
QUALITY CONTROL PROFILING, ANTIFUNGAL AND IN VIVO CYTOTOXIC POTENTIAL OF ORIGANUM MAJORANA L.

Phytochemicals in various extracts and essential oil of Origanum majorana L. were screened. In addition, the pharmacognostic profile of leaf powder and essential oil were investigated in order to develop standards for identification and quality control. The findings confirmed for presence of maximum number of phytoconstituents such as carbohydrates, proteins, amino acids, saponins, flavonoids, alkaloids, phenolic compounds, vitamin C and tannin in aqueous extract whilst essential oil possessed only volatile oils, flavonoids and phenols. Subsequent investigation of antifungal potency showed efficacy of essential oil against all the tested pathogens: Aspergillus flavus > A. niger > Candida albicans > A. fumigatus > A. terreus > Penicillium notatum. Brine shrimp lethality assay performed to evaluate the cytotoxicity of all extracts and essential oil exhibited no deleterious toxic effects. These findings, clearly suggest that O. majorana essential oil can be used in quality control of fungi, especially the tested organisms in the present study.
UO2-salenes: neutral receptors for anions with a high selectivity for dihydrogen phosphate

The design and synthesis of neutral macrocyclic receptors that complex cations in apolar solvents with a high degree selectivity are based on the ability to organize nucleophilic binding sites (Lewis bases) in a complementary array. Although macrocycles with quaternary ammonium salts are known to complex anions, selectivity is not simply introduced. Macrocyclic and acyclic ligands that contain Lewis acidic binding sites such as boron, silicon, tin, and mercury bind anions, but these structures lack the possibility of subtle structural variation that is the basis for the selectivity in cation complexation. In this communication we report a novel class of neutral receptors for anions that contain an immobilized Lewis acidic binding site (UO{sub 2}){sup 2+} and in which there are ample opportunities to introduce specific secondary binding sites. This concept leads to high thermodynamic stabilities combined with high selectivities. Neutral anion receptors are very important for application in sensors and membrane transport experiments. This unique combination of a Lewis acidic uranyl center and the presence of amide NH groups which can form a favorable H-bond with a coordinated anion guest, in a preorganized receptor, can lead to highly specific anion recognition. 20 refs., 2 figs., 1 tab.
High-angle Kikuchi patterns

A cylindrical specimen chamber and camera have been used to study the high-angle Kikuchi patterns obtained by reflexion of electrons, of energy 6 to 50 keV, from the cleavage surfaces of crystals with the sodium chloride structure. Angles of scattering ranging from 0 to 164° were covered. The relative intensity of the pattern at different scattering angles was measured using a photographic technique. The intensity distribution was found to become less steep as the energy of the incident electrons decreased. In photographs taken with a large value of the glancing angle of incidence, defect bands were found, starting near the shadow edge of the pattern; these changed to excess bands at higher angles of scattering. The most striking feature of the results is the remarkable intensity and clarity at the highest scattering angles of the pattern produced by crystals such as lead sulphide and potassium iodide, the constituents of which have a relatively high elastic scattering cross-section. In marked contrast, a relatively low intensity and low clarity was found at these angles for lithium fluoride under the same experimental conditions. An investigation of the width of Kikuchi bands, visible over the whole available angular range, showed that the electrons forming these bands had the same energy as that of the incident electrons within the experimental error of 10%. A possible mechanism is discussed by means of which electrons can be diffused through large angles with high efficiency, relative to small angles, and with relatively little loss of energy.
Time for a shift in crop production: embracing complexity through diversity at all levels

A radical shift in our approach to crop production is needed to ensure food security and to address the problems of soil degradation, loss of biodiversity, polluted and restricted water supplies, coupled with a future of fossil fuel limitations and increasingly variable climatic conditions. An interdisciplinary network of European scientists put forward visions for future crop production embracing the complexity of our socio-ecological system by applying the principle of diversity at all levels from soil micro-organisms to plant varieties and cropping systems. This approach, integrated with careful deployment of our finite global resources and implementation of appropriate sustainable technology, appears to be the only way to ensure the scale of system resilience needed to cope with many of our concerns. We discuss some of the most important tools such as (i) building soil fertility by recycling of nutrients and sustainable use of other natural and physical resources, (ii) enhancing biological diversity by breeding of crops resilient to climate change and (iii) reconnecting all stakeholders in crop production. Finally, we emphasise some of the changes in agricultural and environmental regulation and policy needed in order to implement the visions.
Rigorous quantitative elemental microanalysis by scanning electron microscopy/energy dispersive x-ray spectrometry (SEM/EDS) with spectrum processing by NIST DTSA-II

Quantitative electron-excited x-ray microanalysis by scanning electron microscopy/silicon drift detector energy dispersive x-ray spectrometry (SEM/SDD-EDS) is capable of achieving high accuracy and high precision equivalent to that of the high spectral resolution wavelength dispersive x-ray spectrometer even when severe peak interference occurs. The throughput of the SDD-EDS enables high count spectra to be measured that are stable in calibration and resolution (peak shape) across the full deadtime range. With this high spectral stability, multiple linear least squares peak fitting is successful for separating overlapping peaks and spectral background. Careful specimen preparation is necessary to remove topography on unknowns and standards. The standards-based matrix correction procedure embedded in the NIST DTSA-II software engine returns quantitative results supported by a complete error budget, including estimates of the uncertainties from measurement statistics and from the physical basis of the matrix corrections. NIST DTSA-II is available free for Java-platforms at: http://www.cstl. nist.gov/div837/837.02/epq/dtsa2/index.html).