Miracle-dz/UniFAR-FTUs huggingface dataset:
Use of monolithic silica columns to increase analytical throughput for metabolite identification by liquid chromatography/tandem mass spectrometry

It has been shown that the use of short monolithic silica columns coupled to mass spectrometry provides reduced analytical run times for the purpose of metabolite identification from in vitro samples compared to conventional analytical chromatography, with no loss in chromatographic performance. Six hydroxylated debrisoquine isomers were separated in 1 min, with adequate resolution to enable peak assignment. The resolution and selectivity achieved using short monolithic silica columns were comparable to conventional analytical chromatography and the analysis time per sample was reduced from 30 to 5 min. Copyright © 2001 John Wiley & Sons, Ltd.
Inequality and savings: a reassesment of the relationship in cointegrated panels

The effect of income inequality on savings and consumption has remained an open empirical issue despite several decades of research. Results obtained in this study indicate that income inequality and private consumption are both I(1) nonstationary variables that are cointegrated, and inequality has had a negative effect on private consumption in Central-European and Nordic countries. Results for Anglo-Saxon countries are inconclusive. These findings suggest that previous empirical research may have produced biased results on the effect of inequality on savings by assuming that inequality would be a stationary variable.
Formation of Periodically Ordered Zinc Oxide Nanopillars in Aqueous Solution: An Approach to Photonic Crystals at Visible Wavelengths

The creation of micropatterned materials has recently become an important subject in many areas of science and technology, including microfluidics, optics, electronics, and information storage. [1–4] Obtaining micropatterned wide-band-gap oxides, such as zinc oxide, [5,6] indium tin oxide, [7] and titania, [8,9] is important for realizing transparent optoelectronics applications at UV-vis wavelengths. In particular, ZnO is promising for use in optoelectronic devices such as light emitters and waveguides at UV-vis wavelengths, [10,11] and thus the fabrication of ZnO microstructures is important for industrial applications. Chemical methods, such as the formation of self-assembled monolayers, [5,8,9] interference lithography, [12,13] and conventional lithography, [6,14
PEG-functionalized ionic liquids for cellulose dissolution and saccharification

Cellulose-dissolving ionic liquids (ILs) have become powerful neoteric solvents in the pretreatment of cellulosic biomass for ethanol fuel production. There are, however, a number of challenges to using current ionic solvents at large scales (imidazolium-based salts, in particular), including their relatively high costs and viscosities and their sluggish biodegradability. Aiming to overcome these hurdles, we have prepared a new series of poly(ethylene glycol) (PEG)-functionalized ILs comprising inexpensive alkylammonium or piperidinium cations paired with acetate anions. Some of these new ILs are capable of dissolving 8–12 wt% cellulose, while displaying low viscosities and acceptable thermal stabilities at the required process temperature. Our XRD and SEM data further confirm that regenerative pretreatment of cellulose by these PEGylated ILs can effectively transform the cellulose I structure to cellulose II, reducing the crystallinity of cellulose and increasing the structural homogeneity. Most excitingly, cellulose regenerated from these ILs can be rapidly hydrolyzed to glucose, in ∼90% glucose yield after 2 h, using a commercial cellulase supplemented with β-glucosidase.
Carbon aerogel composite electrodes

The electrochemical behavior and analytical performance of new vitreous carbon aerogel composite electrodes are described. These new composite electrodes rely on the unique open-cell nanostructure of aerogel materials, including their interconnected porosity, ultrafine pore sizes (<50 nm), and huge surface area. Transmission and scanning electron microscopies are used to shed useful insights into the carbon network. The enhanced diffusional flux results in a sigmoidal voltammetric response and nonlinear i vs t[sup [minus]1/2] chronoamperometric plots. The potential window is broad, and the background currents are low. Square-wave anodic stripping voltammetry at the mercury-coated carbon aerogel composite electrode is demonstrated for the quantitation of trace metals at the microgram per liter level using short deposition periods. These carbon aerogels and other aerogels present new opportunities for a wide range of electrode materials. 15 refs., 6 figs.
Isocyanide‐Catalyzed Reaction of Tetracyanoethylene and Activated 1,3‐Dicarbonyl CH‐Acid Compounds: A Rapid and Efficient Synthesis of Pyran Annulated Heterocyclic Systems

Abstract An isocyanide‐catalyzed reaction between tetracyanoethylene and various activated CH‐acid compounds to afford the corresponding pyran annulated heterocyclic ring systems, in high yield at room temperature within a few minutes, is described. To the best of our knowledge, this is the first example in which isocyanide functions as only a catalyst but not a reagent.
Observation of quadrupolar x-ray diffraction peaks in NdMg

In a previous paper, we discussed the use of multiaxial magnetic structures in rare-earth compounds as test systems for x-ray scattering by orbital non-collinear 4f structures. We here present an experiment using synchrotron radiation, which, meanwhile, has given encouraging results regarding this use of x-ray diffraction: the scattering of x-rays by NdMg within its multiaxial magnetic phase yields tiny Bragg reflections which are very likely to be of quadrupolar origin. Indeed, these peaks have been found at the positions and with the intensities expected for such a charge scattering.
Synoptic variations in atmospheric CO2 at Cape Grim: a model intercomparison

A ‘TransCom’ model intercomparison is used to assess how well synoptic and diurnal variations of carbon dioxide (CO2) and 222Rn (radon) can be modelled at the coastal site, Cape Grim, Australia. Each model was run with prescribed fluxes and forced with analysed meteorology for 2000–2003. Twelve models were chosen for analysis based on each model’s ability to differentiate baseline CO2 concentrations from non-baseline CO2 (influenced by regional land fluxes). Analysis focused on non-baseline events during 2002–2003. Radon was better simulated than CO2, indicating that a spatially uniform radon land flux is a reasonable assumption and that regional-scale transport was adequately captured by the models. For both radon and CO2, the ensemble model mean generally performed better than any individual model. Two case studies highlight common problems with the simulations. First, in summer and autumn the Cape Grim observations are sometimes influenced by Tasmanian rather than mainland Australian fluxes. These periods are poorly simulated. Secondly, an event with an urban plume demonstrates how the relatively low spatial resolution of the input CO2 fluxes limits the quality of the simulations. Analysis of periods with below baseline concentration indicates the possible influence of carbon uptake by winter crops in southern mainland Australia.
Solution-processed colloidal quantum dot photovoltaics: A perspective

Deployed solar cells today are predominantly first-generation devices based on silicon. Single-crystal materials offer the advantage of high efficiency, but costs associated with materials, manufacturing, and installation remain high. Second generation, or thin-film, technologies, such as those based on CdTe and CuInGaSe2, offer dramatically improved costs per square meter, but at the price of lower efficiencies. Third-generation photovoltaics aspire to unite high efficiency with low cost. Strategies include nanostructured semiconductors, inorganic‐organic hybrid structures, and molecular assemblies. Solution-processed colloidal quantum dot (CQD) photovoltaic devices offer considerable promise as a third-generation photovoltaic candidate. Their solution-synthesis and -coating offer a path to low-cost roll-to-roll manufacturing atop flexible, lightweight substrates. The bandgap of CQDs is tuned via the nanoparticles’ diameter, allowing them to absorb the sun’s broad visible and infrared spectrum within a single materials-processing strategy. CQD photovoltaics have, with only a half-decade’s intense activity, reached above 5% solar power conversion efficiency, 1,2 and progress shows no signs of abating. Here we review the latest advances in the field and discuss the avenues for further progress towards commercially compelling performance. We include a discussion of the materials themselves, considering their synthesis and their photophysical properties. We review briefly the fundamentals of semiconductors and solar cells. We highlight the major progress and achievements in CQD photovoltaics, focusing on the introduction of improved device architectures.
Supramolecular Prodrug Micelles Constructed by Drug-Drug Conjugate with Water Soluble Pillar(6)arene for Controllable and Rapid Drug Release

The first attempt of constructing supramolecular prodrug micelles based on the host-guest interaction between water-soluble pillar(6)arene (WP6) and a novel doxorubicin (DOX)-based drug-drug conjugate (G) is reported, in which the drug-drug conjugate is synthesized by conjugating anticancer drug DOX with another drug isoniazide via the acid-cleavable hydrazone bond. The obtained WP6⊃G micelles are stable under physiological conditions, whereas the cumulative release of DOX is approximate to 100% within 30 min at pH 5.5 by simulating the endo-lysosomal environment at 37 ℃. Therefore, this WP6-based prodrug micelles can achieve efficient DOX ac- cumulation in the acidic tumor cells within a short period of time, which is very important and valuable; meanwhile it can also reduce the unexpected premature burst release under physiological condition. Furthermore, cellular in- ternalization and localization experiments demonstrated that these prodrug micelles enter cancer cells mainly via endocytosis and can lead to significant drug accumulation in SKOV3 cancer cells, implying its promising future for cancer therapy.
Molecular weight distributions in emulsion polymerizations: Evidence for coagulative nucleation

An examination of the number molecular weight distribution from emulsion polymerizations, obtained by using gel permeation chromatography, shows that, at low conversion, a distinct maximum is present at low molecular weights, while at higher molecular weights the distribution is exponential with decay constant given by the ratio of the rate coefficients of propagation and transfer. The maximum is attributed to coagulation of precursor particles during particle formation.
Necessary conditions for the homogeneous formation of pulsed avalanche discharges at high gas pressures

The preionization level and other initial conditions necessary for the formation of spatially homogeneous pulsed avalanche discharges at high gas pressures are examined. Assuming properly shaped electrodes with no strong edge effects, the minimum preionization level required for homogeneous discharge initiation is found to depend on the voltage rise time across the electrodes as well as on the total pressure and various electrochemical properties of the gas mixture which govern the net rate of change of the first Townsend coefficient with respect to the local electric field strength. Our predictive results are found to be consistent with experimental observations.
Vibrational dynamics of the bifluoride ion. II. Adiabatic separation and proton dynamics

Vibrational dynamics of the bifluoride ion FHF−, which exhibits strongly anharmonic and nonseparable vibrations, is studied using the extended ab initio model potential surface described in the first paper of this series. Adiabatic separation of the proton motion from the F–F (ν1) motion forms a zero‐order basis for description, although strong coupling of adiabatic states by the ν1 motion is important in higher vibrational levels and must be considered to understand the spectrum. The adiabatic protonic eigenstates at F–F separations R from 3.75 to 6.40 a.u. have been determined using the self‐consistent field approximation in prolate spheroidal coordinates to provide a basis set for configuration interaction expansion of the exact eigenstates. 78 SCF eigenstates (21 σg, 21 σu, 21 πu, and 15 πg) were computed by ‘‘exact’’ numerical solution of the SCF equations.The adiabatic CI eigenstates are shown to be converged in energy to better than 1.0 cm−1 for the ground state of each symmetry type and usually be.
Polyaniline Bilayer Composite Electrode for Efficient Polymer Light Emitting Diodes

Abstract We reported that by using a combination of polyaniline (PANI) and Indium/tin oxide (ITO) as the transparent anode of a polymer light emitting diode with poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene), (MEH-PPV), as the active layer, device performance can be significantly improved. The operating voltage can be reduced by ∼ 30-50%, and the quantum efficiency can be increased by ∼ 30-40% with respect to the devices using IT0 alone as the hole-injecting anode. The barrier height at the PANI/MEH-PPV interface is estimated to be ∼ 0.08-0.12eV, approximately half of that at the ITO/MEH-PPV interface.
Stochastic transformation of quantum similarity matrices and their use in quantum QSAR (QQSAR) models

A stochastic transformation of quantum similarity matrices is described and its role in the field of quantitative structure–activity relationship (QSAR) analyzed. The possible interest to manipulate in such a way a quantum similarity matrix, computed over a quantum object set, is diverse. First, any quantum similarity matrix column or row can easily become a discrete probability distribution, associable to a corresponding quantum object density function. Second, in order to ease its subsequent use, the resulting quantum stochastic matrix can be easily symmetrized, by means of any usual procedure or, as described here, by an inward matrix product algorithm. Third, the final matrix transform can be considered as a new quantum similarity index and can be used as a new quantum object descriptor in QSAR models. Fourth, such symmetric stochastic transform can acquire an interesting role in the approximate solution of the fundamental quantum QSAR (QQSAR) equation under various assumptions. Finally, a new algorithm, based on inward matrix product algebra, to obtain strictly positive constrained solutions of the fundamental QQSAR equation, is described. Some application examples are provided in order to illustrate the previous theoretical development. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 163–177, 2000 © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 163–177, 2000
Solid Phase Synthesis of Peptide C-Terminal Thioesters by Fmoc/t-Bu Chemistry

Peptide C-terminal thioesters are key intermediates in a variety of applications, most notably the recently developed native chemical ligation methods for the total chemical synthesis of proteins. So far they have been prepared only by the use of the least prevalent Boc/benzyl solid-phase method on ad hoc prepared resin supports. We describe here a novel method for the solid phase synthesis of thioesters by the most prevalent Fmoc/t-Bu method. The method is based on the use of a 3-carboxypropanesulfonamide safety-catch linker, which is fully stable to repetitive exposure to the basic conditions needed for Fmoc cleavage. Activation with diazomethane or iodoacetonitrile followed by displacement with a suitable thiol produces the thioester in good to excellent yields. The method is also compatible with Boc/benzyl chemistry. Moreover, all the necessary reagents are commercially available.
Alignment of Liquid Crystals on the Stretched Polymer Films

Abstract Several kinds of the stretched polymer films, such as those of cellulose, polyvinylalcohol, and polyethylene are shown to have aligning capability for nematic liquid crystals (a mixture of cyanobiphenyls) in the direction of the stretching when the films are stretched over about 100%. Among them polyethylene is only one exceptional case where the initial aligning property lasts only for several days at room temperature.
CROP SPECIES AND TILLAGE EFFECTS ON CARBON SEQUESTRATION IN SUBSURFACE SOIL

Crop species and conservation tillage may enhance carbon (C) and nitrogen (N) sequestration potential in subsurface soils. The objectives of this study were to determine the effects of crop species and tillage on soil organic C (SOC) and total N distribution in six soil depth intervals from 0 to 105 cm after 20 years of treatment imposition. Tillage had the most influence on soil C and N at 0 to 5 cm, and impacts extended to the 15- to 30-cm depth for wheat and sorghum. Overall, SOC and total N for wheat were 18 and 15% higher than sorghum and soybean. Dissolved organic C (DOC) depth distribution was similar to SOC and total N. The proportion of SOC as DOC ranged from 1.3 to 3.3% and increased with soil depth. The highest soil C and N levels occurred for wheat under no tillage. The depth of soil impacted by crop species was shallower for conventional tillage than no tillage, and the depth distribution exhibited a logarithmic pattern. Soil organic C, total N, and DOC decreased 404, 507, and 205%, respectively from 0-5 to 80-105 cm. The maximum depth interval below which no further decreases in SOC and total N occurred was 30 to 55 cm for soybean, 55 to 80 cm for wheat, and 80 to 105 cm for sorghum, demonstrating the importance of subsurface soils for C sequestration. Crop management impacts below the depth of tillage demonstrate the importance of crop rooting and belowground biomass, or translocation of dissolved organic matter, to subsoil C sequestration.
Effects of sapphire substrate misorientation on the GaN‐based light emitting diode grown by metalorganic vapour phase epitaxy

We have systematically investigated the influence of sapphire substrate misorientation on the structural and optical properties of GaN-based LEDs grown by MOVPE. The LED properties were found to be very sensitive to the misorientation. We grew five samples of LEDs on sapphire substrates with various misorientation angles (0.02∼1.0°). The EL intensity increased when misorientation angles increased to 0.25°. The intensity, however, decreased dramatically when misorientation angles exceeded 0.25°. We also grew the samples of each layer of the LEDs, viz., GaN, InGaN, InGaN/GaN MQWs, and p-GaN layer. CL and PL analyses showed that the crystalline quality of InGaN (MQWs) layer became lower while that of GaN layer improved as misorientation angles increased. In addition, the increased misorientation caused the decreased indium composition and the indium compositional fluctuation. Moreover, the hole (carriers) concentration of p-GaN layer decreased with increasing misorientation angles. As these results, the misorientation angle of around 0.25° is suitable for the LEDs. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Stimuli-responsive polymer vesicles

Polymer vesicles, commonly called polymersomes, are spherical shell structures in which an aqueous compartment is enclosed by a bilayer membrane made from amphiphilic block copolymers. Compared to liposomes, their low molecular weight analogues, polymersomes have many superior properties (higher toughness, better stability, tailorable membrane properties), which make them attractive candidates for applications including encapsulation, drug delivery, nanoreactors and templates for micro- or nano-structured materials. Many potential applications require the ability to control the release of substances encapsulated in the interior compartment and/or in the hydrophobic core of membrane. To address this goal, polymersomes have to be developed in which a specific stimulus destabilises the vesicle structure. In this article we review the most promising approaches to make stimuli-responsive polymer vesicles that permit the controlled release of encapsulated contents. Stimuli including hydrolysis, oxidation, reduction, pH, temperature and light are discussed and their effect on the chemical and physical structure of the amphiphilic copolymers is also described.
Two‐dimensional magic angle spinning NMR investigation of naturally occurring chitins: Precise 1H and 13C resonance assignment of α‐ and β‐chitin

13C homonuclear through‐bond correlations of α‐ and β‐chitin were determined by using two‐dimensional (2D) INADEQUATE spectra of these allomorphs purified from crab shell and squid pen, respectively. The 2D 13C–13C correlation spectra where two directly bonded carbons share a common double‐quantum frequency (DQ) enabled us to precisely assign all 13C resonances of the chitin allomorphs for the first time. Following the complete 13C assignment, 1H chemical shifts of protons attached to each carbon nuclei were assigned by 2D frequency‐switched Lee–Goldberg (FSLG) 1H–13C heteronuclear correlation (HETCOR) spectra of the chitin allomorphs, recorded with a short mixing time (60 μs) to provide isotropic 1H–13C chemical shift correlations between bonded pairs proton and carbon nuclei. From the 13C and 1H chemical shifts of chitin allomorphs, all 2‐deoxy‐2‐acetamide‐D‐glucose (N‐acetyl‐D‐glucosamine) monomer units in each allomorph were revealed to be an identical 13C–13C backbone conformation and magnetically equivalent. In addition, it was strongly suggested that there are two different hydrogen‐bonding patterns at the hydroxyl groups of α‐chitin by comparing 1H chemical shifts at the C6 site of α‐chitin with those at the same site of β‐chitin. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Effects of Soil Rhizosphere Aeration on the Root Growth and Water Absorption of Tomato

Soil rhizosphere aeration status is an important aspect of soil quality and soil ecology. The objective of the current study was to determine the appropriate moisture environment that facilitates rhizosphere soil aeration and ensures normal root respiration in tomato. In the potted experiment, five treatments of soil aeration were used (0.4, 0.8, 1.2, 1.6 ventilation volume of 50% porosity of soil, and no ventilation) under conditions of the different soil moisture upper limits. The effects of different rhizosphere soil aerations on the physiological indicators and water absorption of tomato were studied. Under the same soil moisture condition, plant growth and root vitality initially increased, and then decreased when the soil ventilation volume increased. The combination of soil moisture with 80% of field capacity and 0.8 ventilation volume with 50% soil porosity raised the chlorophyll content by 29.98% and the root vitality by 61.55%, as compared with the non-ventilated treatment. Therefore, the appropriate volume of rhizosphere ventilation can effectively improve the capacity of water absorption in tomato. The result provides a new view about soil quality and soil ecology in terms of soilroot system.