gebhart/patrepeval huggingface dataset:
Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass (2023)

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.
Nearest-neighbor Ising model with a uniaxial incommensurate phase and a Lifshitz point (1984)

The anisotropic triangular nearest-neighbor Ising model, with antiferromagnetic interactions, is studied. The phase diagram, as a function of temperature and field, has a complex structure. Two commensurate ordered phases are found. The transition to one is Ising-type. The second is reached from the disordered phase in one of two ways: either via an intermediate uniaxial incommensurate phase---which is reached at high temperatures by a Kosterlitz-Thouless transition and at low temperatures undergoes an incommensurate-commensurate transition---or by a single continuous transition. The latter transition is in the same universality class as the chiral three-state Potts model, with thermal exponent within 4% of that of the three-state Potts model. These two transition regimes are found to be separated by a Lifshitz point. The phase diagram and critical behavior were determined by analytical (symmetry analysis and free-fermion approximation) as well as numerical (phenomenological renormalization-group and Monte Carlo) methods.
Fully Vectorial Accelerating Diffraction-Free Helmholtz Beams (2012)

We show that new families of diffraction-free nonparaxial accelerating optical beams can be generated by considering the symmetries of the underlying vectorial Helmholtz equation. Both two-dimensional transverse electric and magnetic accelerating wave fronts are possible, capable of moving along elliptic trajectories. Experimental results corroborate these predictions when these waves are launched from either the major or minor axis of the ellipse. In addition, three-dimensional spherical nondiffracting field configurations are presented along with their evolution dynamics. Finally, fully vectorial self-similar accelerating optical wave solutions are obtained via oblate-prolate spheroidal wave functions. In all occasions, these effects are illustrated via pertinent examples.
Identification of two dihydrodipicolinate synthase isoforms from Pseudomonas aeruginosa that differ in allosteric regulation (2019)

Pseudomonas aeruginosa is one of the leading causes of nosocomial infections, accounting for 10% of all hospital-acquired infections. Current antibiotics against P. aeruginosa are becoming increasingly ineffective due to the exponential rise in drug resistance. Thus, there is an urgent need to validate and characterize novel drug targets to guide the development of new classes of antibiotics against this pathogen. One such target is the diaminopimelate (DAP) pathway, which is responsible for the biosynthesis of bacterial cell wall and protein building blocks, namely meso-DAP and lysine. The rate-limiting step of this pathway is catalysed by the enzyme dihydrodipicolinate synthase (DHDPS), typically encoded for in bacteria by a single dapA gene. Here, we show that P. aeruginosa encodes two functional DHDPS enzymes, PaDHDPS1 and PaDHDPS2. Although these isoforms have similar catalytic activities (k<sub>cat</sub> = 29 s<sup>-1</sup> and 44 s<sup>-1</sup> for PaDHDPS1 and PaDHDPS2, respectively), they are differentially allosterically regulated by lysine, with only PaDHDPS2 showing inhibition by the end product of the DAP pathway (IC<sub>50</sub> = 130 μm). The differences in allostery are attributed to a single amino acid difference in the allosteric binding pocket at position 56. This is the first example of a bacterium that contains multiple bona fide DHDPS enzymes, which differ in allosteric regulation. We speculate that the presence of the two isoforms allows an increase in the metabolic flux through the DAP pathway when required in this clinically important pathogen. DATABASES: PDB ID: 6P90.
Selective oxidation of CO in the presence of H2, H2O and CO2via gold for use in fuel cells (2005)

An Au/Fe2O3 catalyst prepared using a two-stage calcination procedure achieves target conversion and selectivity for the competitive oxidation of dilute CO in the presence of moist excess H2 and CO2.
Amorphous calcium carbonate transforms into calcite during sea urchin larval spicule growth (1997)

Sea urchin larvae form an endoskeleton composed of a pair of spicules. For more than a century it has been stated that each spicule comprises a single crystal of the CaCO(3) mineral, calcite. We show that an additional mineral phase, amorphous calcium carbonate, is present in the sea urchin larval spicule, and that this inherently unstable mineral transforms into calcite with time. This observation significantly changes our concepts of mineral formation in this well-studied organism.
High‐Gain Chemically Gated Organic Electrochemical Transistor (2021)

Abstract Organic electrochemical transistors (OECTs) have exhibited promising performance as transducers and amplifiers of low potentials due to their exceptional transconductance, enabled by the volumetric charging of organic mixed ionic/electronic conductors (OMIECs) employed as the channel material. OECT performance in aqueous electrolytes as well as the OMIECs’ redox activity has spurred a myriad of studies employing OECTs as chemical transducers. However, the OECT's large (potentiometrically derived) transconductance is not fully leveraged in common approaches that directly conduct chemical reactions amperometrically within the OECT electrolyte with direct charge transfer between the analyte and the OMIEC, which results in sub‐unity transduction of gate to drain current. Hence, amperometric OECTs do not truly display current gains in the traditional sense, falling short of the expected transistor performance. This study demonstrates an alternative device architecture that separates chemical transduction and amplification processes on two different electrochemical cells. This approach fully utilizes the OECT's large transconductance to achieve current gains of 10 3 and current modulations of four orders of magnitude. This transduction mechanism represents a general approach enabling high‐gain chemical OECT transducers.
Effects of the rf current and bias field direction on the transition from linear to non-linear gyrotropic dynamics in magnetic vortex structures (2022)

We present a frequency-domain study of the dynamic behavior of a magnetic vortex core within a single Permalloy disk by means of electrical detection and micromagnetic simulations. When exciting the vortex core dynamics in a non-linear regime, the lineshape of the rectified dc signal reveals a resonance peak splitting which depends on the excitation amplitude. Using micromagnetic simulations, we show that at high excitation power the peak splitting originates from the nanosecond time scale quasi-periodic switching of the vortex core polarity. Using lock-in detection, the rectified voltage is integrated over a ms time scale, so that the net signal detected between the two resonant peaks for a given range of parameters cancels out. The results are in agreement with the reported effects of the in-plane static field magnitude on the gyration dynamics, and complement them by detailed analysis of the effects of the rf current amplitude and the azimuthal angle of the in-plane bias magnetic field. Systematic characterization shows that a transition from linear to nonlinear dynamical regime can be controlled by rf current as well as by varying the magnitude and the direction of the bias magnetic field.
Performance of a new 3D-only PET scanner-the EXACT3D (2002)

Characteristics of currently the highest sensitivity 3D-only PET scanner (CTI/Siemens 966/EXACT3D) have been studied. The device has 48 rings (82 cm diameter) of BGO detector elements (4.0/spl times/4.1/spl times/30 mm, 8/spl times/8 block) and an axial FOV of 23.4 cm. Attenuation correction is carried out with a point source of /sup 137/Cs which moves under hydraulic pressure in a helical tube. Transaxial resolution is 4.7 mm 1 cm from the centre of the FOV increasing, in the radial direction to 6.3 mm and 7.3 mm at 10 cm and 15 cm. At a lower threshold of 350 keV, the scatter fraction is 40%. With scatter subtracted, the efficiency (20 cm cylinder) is 6.9/spl times/10/sup 4/ cps/kBq/ml (maximum ring difference of 40); the absolute sensitivity is 5.8%. In the current configuration, the maximum total coincidence event rate is limited to about 3/spl times/10/sup 6/ per sec. The maximum true rate is about 850 kcps (90 MBq in the FOV). List mode acquisition has been implemented to maximise temporal resolution and optimise data storage. The more open geometry of this device gives a broader singles FOV. Hence administered doses and/or additional side-shielding need to be carefully considered to optimise noise-equivalent counts.
Performance of the JWST/MIRI Si:As detectors (2008)

The Mid-Infrared Instrument (MIRI) is a 5 to 28 micron imager and spectrometer that is slated to fly aboard the JWST in 2013. Each of the flight arrays is a 1024&times;1024 pixel Si:As impurity band conductor detector array, developed by Raytheon Vision Systems. JPL, in conjunction with the MIRI science team, has selected the three flight arrays along with their spares. We briefly summarize the development of these devices, then describe the measured performance of the flight arrays along with supplemental data from sister flight-like parts.
Diverting Glycolysis to Combat Oxidative Stress (2015)

Reactive oxygen species (ROS) are an intricate part of normal cellular physiology. In excess, however, ROS can damage all three major classes of macromolecules and compromise cell viability. We briefly discuss the physiology of ROS but focus on the mechanisms cells use to preserve redox homeostasis upon oxidative stress, with particular emphasis on glycolysis. ROS inhibits multiple glycolytic enzymes, including glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase M2, and phosphofructokinase-1. Consistently, glycolytic inhibition promotes flux into the oxidative arm of the pentose phosphate pathway to generate NADPH. NADPH is critically important, as it provides the reducing power that fuels the protein-based antioxidant systems and recycles oxidized glutathione. The unique ability of pyruvate kinase M2 inhibition to promote serine synthesis in the context of oxidative stress is also discussed.
Early decrease of serum biomarkers of type II collagen degradation (Coll2-1) and joint inflammation (Coll2-1NO2) by hyaluronic acid intra-articular injections in patients with knee osteoarthritis (2011)

peer reviewed
ϒ production in p–Pb collisions at sNN=8.16 TeV (2020)

production in p-Pb interactions is studied at the centre-of-mass energy per nucleon-nucleon collision s NN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < y cms < 3.53 and -4.46 < y cms < -2.96, down to zero transverse momentum. In this work, results on the (1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the (1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the (2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the (1S). A first measurement of the (3S) has also been performed. Finally, results are compared with previous ALICE measurements in p-Pb collisions at s NN = 5.02 TeV and with theoretical calculations.
La-related protein 1 (LARP1) repression of TOP mRNA translation is mediated through its cap-binding domain and controlled by an adjacent regulatory region (2017)

Cell growth is a complex process shaped by extensive and coordinated changes in gene expression. Among these is the tightly regulated translation of a family of growth-related mRNAs defined by a 5' terminal oligopyrimidine (TOP) motif. TOP mRNA translation is partly controlled via the eukaryotic initiation factor 4F (eIF4F), a translation factor that recognizes the mRNA 5' cap structure. Recent studies have also implicated La-related protein 1 (LARP1), which competes with eIF4F for binding to mRNA 5' ends. However, it has remained controversial whether LARP1 represses TOP mRNA translation directly and, if so, what features define its mRNA targets. Here, we show that the C-terminal half of LARP1 is necessary and sufficient to control TOP mRNA translation in cells. This fragment contains the DM15 cap-binding domain as well as an adjacent regulatory region that we identified. We further demonstrate that purified LARP1 represses TOP mRNA translation in vitro through the combined recognition of both the TOP sequence and cap structure, and that its intrinsic repressive activity and affinity for these features are subject to regulation. These results support a model whereby the translation of TOP mRNAs is controlled by a growth-regulated competition between eIF4F and LARP1 for their 5' ends.
In Situ XAS Studies of Core-Shell PEM Fuel Cell Catalysts: The Opportunities and Challenges (2011)

Core-shell electrocatalysts are of increased interest in PEM fuel cells as a means of improving activity and reducing costs. In situ x-ray absorption spectroscopy (XAS) provides a unique opportunity to provide characterization of the structure of such materials under operating conditions, enabling the effects of the electrochemical environment on the structures to be explored. However, such measurements present numerous challenges in terms of both data collection and analysis. Here we present two case studies that illustrate both the opportunities and challenges; (i) the modification of a Pt catalyst by Ru and the potential dependent formation of a surface alloy and (ii) a Pt shell - Pd core catalyst with varying shell thickness.
Phase-dependent laser acceleration of electrons with symmetrically driven silicon dual pillar gratings (2018)

We present the demonstration of phase-dependent laser acceleration and deflection of electrons using a symmetrically driven silicon dual pillar grating structure. We show that exciting an evanescent inverse Smith-Purcell mode on each side of a dual pillar grating can produce hyperbolic cosine acceleration and hyperbolic sine deflection modes, depending on the relative excitation phase of each side. Our devices accelerate sub-relativistic 99.0 keV kinetic energy electrons by 3.0 keV over a 15 μm distance with accelerating gradients of 200 MeV/m with 40 nJ, 300 fs, 1940 nm pulses from an optical parametric amplifier. These results represent a significant step towards making practical dielectric laser accelerators for ultrafast, medical, and high-energy applications.
Robust Triplet Molecule:  Cationic Diradical of 3,4‘-Bis(diphenylamino)stilbene (1999)

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTRobust Triplet Molecule: Cationic Diradical of 3,4'-Bis(diphenylamino)stilbeneTsuyoshi Michinobu, Masahiro Takahashi, Eishun Tsuchida, and Hiroyuki NishideView Author Information Department of Polymer Chemistry, Waseda University, Tokyo 169-8555, Japan Cite this: Chem. Mater. 1999, 11, 8, 1969–1971Publication Date (Web):July 24, 1999Publication History Received14 May 1999Revised14 June 1999Published online24 July 1999Published inissue 1 August 1999https://pubs.acs.org/doi/10.1021/cm990295jhttps://doi.org/10.1021/cm990295jrapid-communicationACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views310Altmetric-Citations37LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Electron paramagnetic resonance spectroscopy,Oxidation,Phytochemistry,Quantum mechanics,Stability Get e-Alerts
Joint Channel Estimation and Impulsive Noise Mitigation in Underwater Acoustic OFDM Communication Systems (2017)

Impulsive noise occurs frequently in underwater acoustic (UA) channels and can significantly degrade the performance of UA orthogonal frequency-division multiplexing (OFDM) systems. In this paper, we propose two novel compressed sensing based algorithms for joint channel estimation and impulsive noise mitigation in UA OFDM systems. The first algorithm jointly estimates the channel impulse response and the impulsive noise by utilizing pilot subcarriers. The estimated impulsive noise is then converted to the time domain and removed from the received signals. We show that this algorithm reduces the system bit-error-rate through improved channel estimation and impulsive noise mitigation. In the second proposed algorithm, a joint estimation of the channel impulse response and the impulsive noise is performed by exploiting the initially detected data. Then, the estimated impulsive noise is removed from the received signals. The proposed algorithms are evaluated and compared with existing methods through numerical simulations and on real data collected during a UA communication experiment conducted in the estuary of the Swan River, WA, Australia, during December 2015. The results show that the proposed approaches consistently improve the accuracy of channel estimation and the performance of impulsive noise mitigation in UA OFDM communication systems.
Photoacoustic guidance of high intensity focused ultrasound with selective optical contrasts and time-reversal (2009)

The authors present a method of focusing high intensity ultrasound by time-reversing the photoacoustic response of an optically selective target in a nonselective background. The target’s photoacoustic response was isolated from the background by subtracting the photoacoustic waveforms obtained at different optical wavelengths and convolved with a continuous signal. It was found that the focus produced was comparable in quality to that obtained by delay-law beam-forming. The method holds the promise of allowing precise targeting of high intensity focused ultrasound on nonechogenic targets, in moving environments, independently of the presence of aberrating layers.
A Near-Infrared, Continuous Wavelength, In-Lens Spectroscopic Photon Emission Microscope System (2007)

A near-infrared continuous wavelength, in-lens spectroscopic photon emission microscope has been developed. The dispersive element is a three-element prism which has been specially designed to disperse light from 0.9 mum to 1.6 mum about the optical axis. The system has been used to perform frontside and backside spectroscopy on forward and reverse-biased p-n junctions and saturated nMOSFETs. The difference in the frontside and backside spectra is due to the "silicon filter effect" for the backside spectra and the optical effects of the dielectrics for the frontside spectra.
Sign inversion of the spontaneous polarization in ferroelectric liquid crystals: a thickness dependence study in freely suspended films (1996)

A smectic ferroelectric liquid crystal, which is known to exhibit as a bulk sample at a certain temperature a spontaneous inversion of the direction of the spontaneous electric polarization with respect to the direction of the molecular tilt, is studied in freely suspended films with thicknesses between nearly one hundred and only three molecular layers. The spontaneous polarization inversion is observed in all films regardless of their thickness, and the inversion occurs simultaneously, at the same temperature, in all layers of a given film. The inversion temperature is found to decrease linearly with the reciprocal film thickness indicating the influence of the reduced dimensionality. Our results support the competing-conformers model rather than the dipolar-quadrupolar-coupling model.
Measurement of angular and momentum distributions of charged particles within and around jets in Pb+Pb and pp collisions at sNN=5.02 TeV with the ATLAS detector (2019)

Studies of the fragmentation of jets into charged particles in heavy-ion collisions can provide information about the mechanism of jet quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. This paper presents a measurement of the angular distribution of charged particles around the jet axis in $\sqrt{{s}_{NN}}=5.02$ TeV $\mathrm{Pb}+\mathrm{Pb}$ and pp collisions, using the ATLAS detector at the LHC. The $\mathrm{Pb}+\mathrm{Pb}$ and $pp$ data sets have integrated luminosities of $0.49\phantom{\rule{0.16em}{0ex}}{\mathrm{nb}}^{\ensuremath{-}1}$ and $25\phantom{\rule{0.16em}{0ex}}{\mathrm{pb}}^{\ensuremath{-}1}$, respectively. The measurement is performed for jets reconstructed with the anti-${k}_{t}$ algorithm with radius parameter $R=0.4$ and is extended to an angular distance of $r=0.8$ from the jet axis. Results are presented as a function of $\mathrm{Pb}+\mathrm{Pb}$ collision centrality and distance from the jet axis for charged particles with transverse momenta in the 1- to 63-GeV range, matched to jets with transverse momenta in the 126- to 316-GeV range and an absolute value of jet rapidity of less than 1.7. Modifications to the measured distributions are quantified by taking a ratio to the measurements in $pp$ collisions. Yields of charged particles with transverse momenta below 4 GeV are observed to be increasingly enhanced as a function of angular distance from the jet axis, reaching a maximum at $r=0.6$. Charged particles with transverse momenta above 4 GeV have an enhanced yield in $\mathrm{Pb}+\mathrm{Pb}$ collisions in the jet core for angular distances up to $r=0.05$ from the jet axis, with a suppression at larger distances.