gebhart/patrepeval huggingface dataset:
Coal processing in non-dissolving media (1986)

If coal is contacted with an organic reagent in a medium in which the reagent is marginally soluble, there may be a tendency for the reagent to transfer to the pores and surfaces of the coal, where it has maximum utility for reactions which cleave the coal macromolecular network. Thus, in such media it may be possible to employ lower concentrations of reagents than would be required in totally soluble systems. If, in addition, coal fragments are insoluble in the processing medium, the coal particles will be recovered intact after processing. The reagent can then be washed from the coal, and coal conversion assessed as solubility in a standard solvent. Since the reagent is not present when solubility is measured, conversion should be independent of the solvent properties of the reagent, and only dependent on its ability to break bonds during processing.
ChemInform Abstract: A Novel Trifluoromethanesulfonamidophenyl‐Substituted Quinoline Derivative, GA 0113: Synthesis and Pharmacological Profiles (2001)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Semiconductor 2D and 3D photonic crystals (2002)

Summary form only given. Much interest has been drawing in photonic crystals in which the refractive index changes periodically. A photonic bandgap is formed in the crystals, and the propagation of electromagnetic waves is prohibited for all wave vectors. Various important scientific and engineering applications such as control of spontaneous emission, zero-threshold lasing, very sharp bending of light, and so on, are expected with the photonic bandgap and the artificially introduced defect states and/or light-emitters. In this presentation, the present status of semiconductor 3D and 2D photonic crystals is reviewed. For 3D photonic crystals, the development of complete photonic: crystals at optical wavelengths and the applications to ultrasmall optical circuits have been demonstrated. On the 2D photonic crystals, a coherent lasing action due to coupling of six equivalent light-waves, and a trapping and emission of photons by single defect have been demonstrated.
Erythrocytes Reveal Complement Activation in Patients with COVID-19 (2020)

COVID-19, the disease caused by the SARS-CoV-2 virus, can progress to multi-organ failure characterized by respiratory insufficiency, arrhythmias, thromboembolic complications and shock. The mortality of patients hospitalized with COVID-19 is unacceptably high and new strategies are urgently needed to rapidly identify and treat patients at risk for organ failure. Clinical epidemiologic studies demonstrate that vulnerability to organ failure is greatest after viral clearance from the upper airway, which suggests that dysregulation of the host immune response is a critical mediator of clinical deterioration and death. Autopsy and pre-clinical evidence implicate aberrant complement activation in endothelial injury and organ failure. A potential therapeutic strategy warranting investigation is to inhibit complement, with case reports of successful treatment of COVID-19 with inhibitors of complement. However, this approach requires careful balance between the host protective and potential injurious effects of complement activation, and biomarkers to identify the optimal timing and candidates for therapy are lacking. Here we report the presence of complement activation products on circulating erythrocytes from hospitalized COVID-19 patients using flow cytometry. These findings suggest that novel erythrocyte-based diagnostics provide a method to identify patients with dysregulated complement activation.
Synaptic deregulation of cholinergic projection neurons causes olfactory dysfunction across 5 fly Parkinsonism models (2023)

Abstract The classical diagnosis of Parkinsonism is based on motor symptoms that are the consequence of nigrostriatal pathway dysfunction and reduced dopaminergic output. However, a decade prior to the emergence of motor issues, patients frequently experience non-motor symptoms, such as a reduced sense of smell (hyposmia). The cellular and molecular bases for these early defects remain enigmatic. To explore this, we developed a new collection of five fruit fly models of familial Parkinsonism and conducted single-cell RNA sequencing on young brains of these models. Interestingly, cholinergic projection neurons are the most vulnerable cells and genes associated with presynaptic function are the most deregulated. Additional single nucleus sequencing of three specific brain regions of Parkinson’s disease patients confirms these findings. Indeed, the disturbances lead to early synaptic dysfunction, notably affecting cholinergic olfactory projection neurons crucial for olfactory function in flies. Correcting these defects specifically in olfactory cholinergic interneurons in flies or inducing cholinergic signaling in Parkinson mutant human induced dopaminergic neurons in vitro using nicotine, both rescue age-dependent dopaminergic neuron decline. Hence, our research uncovers that one of the earliest indicators of disease in 5 different models of familial Parkinsonism is synaptic dysfunction in higher-order cholinergic projection neurons and this contributes to the development of hyposmia. Furthermore, the shared pathways of synaptic failure in these cholinergic neurons ultimately contribute to dopaminergic dysfunction later in life.
Development of Epitaxial SiC Processes Suitable for Bipolar Power Devices (2005)

We present a survey of the most important factors relating to an epitaxial SiC growth process that is suitable for bipolar power devices. During the last several years, we have advanced our hot-wall SiC epitaxial growth technology to the point that we can support the transition of bipolar power devices from demonstrations to applications. Two major concerns in developing a suitable epitaxial technology are epilayer uniformity and extended defect density. Our state-of-theart capability permits the realization of 1-cm2 area devices with exceptional yields. Another major concern is the stability of bipolar devices during forward conduction. We have developed proprietary substrate and epilayer preparation technologies that have essentially eliminated Vf drift as a significant barrier to the exploitation of SiC based bipolar devices.
GaN TRANSISTORS FOR POWER SWITCHING AND MILLIMETER-WAVE APPLICATIONS (2009)

We review our state-of-the-art GaN -based device technologies for power switching at low frequencies and for future millimeter-wave communication systems. These two applications are emerging in addition to the power amplifiers at microwave frequencies which have been already commercialized for cellular base stations. Technical issues of the power switching GaN device include lowering the fabrication cost, normally-off operation and further increase of the breakdown voltages extracting full potential of GaN -based materials. We establish flat and crack-free epitaxial growth of GaN on Si which can reduce the chip cost. Our novel device structure called Gate Injection Transistor (GIT) achieves normally-off operation with high enough drain current utilizing conductivity modulation. Here we also present the world highest breakdown voltage of 10400V in AlGaN / GaN HFETs. In this paper, we also present high frequency GaN -based devices for millimeter-wave applications. Short-gate MIS-HFETs using in-situ SiN as gate insulators achieve high f max up to 203GHz. Successful integration of low-loss microstrip lines with via-holes onto sapphire enables compact 3-stage K -band amplifier MMIC of which the small-signal gain is as high as 22dB at 26GHz. The presented devices are promising for the two future emerging applications demonstrating high enough potential of GaN -based transistors.
ESR-Untersuchung zur N-Inversion an freien Radikalen / N-Inversion in Free Radical Molecules Studied by ESR (1983)

The temperature dependence of the ESR spectra of 4-[(Mono-rsp. Di-organyl-amino)-methyl]- 2.6-di-tert.-butyl-phenoxyls is studied. The observed coalescence behaviour of the hfs-parameters of the methylene protons is interpreted by N-inversion in the amine group. Thus it is shown that the μsec time scale of ESR makes it possible to study these processes near ambient temperatures. Evaluation of rate constants and activation parameters was done by computer simulation of the DESR spectra. Comparing these values with those given by DNMR methods at low temperatures show that the radical state of the molecule has no significant effect on the inversion rate constants.
A geometric model for measurement of surface distance, surface area, and volume from tomographic images (1992)

Surface area and volume are essential measurements in the morphometric assessment of anatomical structures. New algorithms were developed to measure (1) distance along a curve, (2) surface area, and (3) volume using data extracted from tomographic images as a geometrical surface model. The model is a list of coordinates and normal vectors for each voxel or point gathered from the surface of a selected object. The resulting surface-based pointlist is also used for high-speed rendering of surfaces. Differential arclength and surface area are measured with high numeric precision by using the absolute value of the maximum component of the unit normal vector (MUNC) to approximate their values. These differential values are summed to measure distance along a curve and surface area. A discrete form of the Divergence theorem, also using the MUNC, is used to calculate volume. The intrinsic accuracy of the measurement algorithms was evaluated using computer generated pointlists of circles, ellipses, spheres, and ellipsoids. Compared to standard measurement techniques, the new algorithms provided the greatest accuracy and least shape-related bias for measurement of distance, surface area, and volume. Feasibility of using the new algorithms to measure physical objects was tested with CT images of spherical, egg-shaped, and irregular shaped objects. The Dividing Cubes algorithm was used to segment and create pointlists from the CT data. Volume and surface area measurements from CT data compared extremely well with reference values for most objects tested (errors less than 2%).
Constitutive Relations of High Temperature Solders (2007)

This study focuses on microelectronic package design for the oil and natural gas drilling of wells with depths in excess of 20,000 ft, where package temperatures can exceed 204°C. At these high temperatures, solder interconnect sites are subject to fatigue and creep failures due to the stress generated by the thermal expansion mismatch between various components in the package. Typically this phenomenon is modeled by finite element analysis (FEA) to predict the number of cycles to failure. To ensure meaningful model results, however, accurate time and temperature-dependent mechanical properties are needed. This study examines five solders suitable for high temperature: 90Pb-10Sn, 95Sn-5Sb, 92.5Pb-5Sn-2.5Ag, 95Pb-5In, and 93Pb-3Sn-2Ag-2In. Uniaxial tension tests of the solder wires are carried out on a MTS servohydraulic machine using wedge grips. To evaluate the time-dependence on deformation, a strain rate study was carried out at 0.5%/sec, 1%/sec, and 5%/sec. Nanoindentation of solder wire is performed and compared to the corresponding solder wires tested through uniaxial tension tests. Dynamic nanoindentation through continuous stiffness measurement is performed on the wires to obtain the indentation data less sensitive to creep of the material, as well as to assess the effect of indentation depth on elastic modulus for each solder. One purpose of nanoindentation testing is to determine its suitability for the mechanical testing of soft solders. Mechanical properties obtained from these tests will be used in future modeling studies to estimate the cyclic fatigue life of these solders under thermal loading.
Loss of exercise-induced cardioprotection after cessation of exercise (2004)

Endurance exercise provides cardioprotection against ischemia-reperfusion (I/R) injury. Exercise-induced cardioprotection is associated with increases in cytoprotective proteins, including heat shock protein 72 (HSP72) and increases in antioxidant enzyme activity. On the basis of the reported half-life of these putative cardioprotective proteins, we hypothesized that exercise-induced cardioprotection against I/R injury would be lost within days after cessation of exercise. To test this, male rats (4 mo) were randomly assigned to one of five experimental groups: 1). sedentary control, 2). exercise followed by 1 day of rest, 3). exercise followed by 3 days of rest, 4). exercise followed by 9 days of rest, and 5). exercise followed by 18 days of rest. Exercise-induced increases (P < 0.05) in left ventricular catalase activity and HSP72 were evident at 1 and 3 days postexercise. However, at 9 days postexercise, myocardial HSP72 and catalase levels declined to sedentary control values. To evaluate cardioprotection during recovery from I/R, hearts were isolated, placed in working heart mode, and subjected to 20.5 min of global ischemia followed by 30 min of reperfusion. Compared with sedentary controls, exercised animals sustained less I/R injury as evidenced by maintenance of a higher (P < 0.05) percentage of preischemia cardiac work during reperfusion at 1, 3, and 9 days postexercise. The exercise-induced cardioprotection vanished by 18 days after exercise cessation. On the basis of the time course of the loss of cardioprotection and the return of HSP72 and catalase to preexercise levels, we conclude that HSP72 and catalase are not essential for exercise-induced protection during myocardial stunning. Therefore, other cytoprotective molecules are responsible for providing protection during I/R.
ChemInform Abstract: Ba2An(S2)2S2 (An: U, Th): Syntheses, Structures, Optical and Electronic Properties. (2013)

Abstract The title compounds are synthesized by reactions of U or Th with BaS and S (1273 K for 4 h and 1223 K for 8 d; 20 wt.% yield for the U compound, 1173 K for 4 d, 50 wt.% yield for the Th compound).
Designing Molecules: Specific Peptides for Specific Receptors (1989)

Peptides are the largest class of mediators of intercellular communication in the central nervous system. These molecules pose special problems in design for potential medical applications because of the high degree of flexibility, lack of high receptor selectivity, and ready biodegradation or clearance. The global and local use of conformational constraints has overcome these difficulties. Structure-biological activity relationships, molecular modeling, conformational analysis, conformational calculations, and molecular dynamics simulations can all be used to derive suitable lead structures and conformational models. Often, a single, constrained peptide analogue can be designed, which will have many of the desired biological and biophysical properties, and will serve as a template. Peptide analogues with high potency, exquisite receptor selectivity, and biological stability can be obtained. The approach is illustrated by the design of cyclic enkephalin-agonist analogues with exceptional delta-opioid-receptor selectivity, and of constrained somatostatin analogues that have become opioid peptides and possess potent opioid antagonist activities and exceptional selectivity for mu-opioid receptors.
Distributed precoding design via over-the-air signaling for cell-free massive MIMO (2021)

Most works on cell-free massive multiple-input multiple-output (MIMO) consider non-cooperative precoding strategies at the base stations (BSs) to avoid extensive channel state information (CSI) exchange via backhaul signaling. However, considerable performance gains can be accomplished by allowing coordination among the BSs. This paper proposes the first distributed framework for cooperative precoding design in cell-free massive MIMO (and, more generally, in joint transmission coordinated multi-point) systems that entirely eliminates the need for backhaul signaling for CSI exchange. A novel over-the-air (OTA) signaling mechanism is introduced such that each BS can obtain the same cross-term information that is traditionally exchanged among the BSs via backhaul signaling. The proposed distributed precoding design enjoys desirable flexibility and scalability properties, as the amount of OTA signaling does not scale with the number of BSs or user equipments. Numerical results show fast convergence and remarkable performance gains as compared with non-cooperative precoding design. The proposed scheme can also outperform the centralized precoding design under realistic CSI acquisition.
Low-Interface-Trap-Density and High-Breakdown-Electric-Field SiN Films on GaN Formed by Plasma Pretreatment Using Microwave-Excited Plasma-Enhanced Chemical Vapor Deposition (2013)

We investigated the SiN/GaN interface properties formed by the microwave-excited plasma-enhanced chemical vapor deposition (PECVD) with <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm SiH}_{4}/{\rm N}_{2}/{\rm H}_{2}$</tex> </formula> gases. The interface and insulating properties of SiN films on GaN, formed by the microwave-excited PECVD, strongly depend on <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm SiH}_{4}$</tex></formula> flow rate. Although the interface trap density is lower than <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$10^{11}~{\rm cm}^{-2}~{\rm eV}^{-1}$</tex></formula> at the relatively high <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm SiH}_{4}$</tex></formula> flow rate of 1.0 standard <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm cm}^{3}/\min$</tex></formula> (sccm), the breakdown electric field is very low (approximately 1 MV/cm). Using the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm SiH}_{4}$</tex></formula> plasma pretreatment before the stoichiometric SiN deposition, both low interface trap density and high breakdown voltage greater than 2 MV/cm were obtained. In this case, the clearly ordered Ga bonding near the SiN/GaN interface was estimated by electron energy loss spectroscopy. The formation of SiN film on GaN using the microwave-excited PECVD is a very useful technique for the high-quality interface properties.
Adsorption-Induced Self-Organization of Calix[4]arene on Au(111) Surfaces (2001)

Abstract The construction and sub-molecular visualization of a self-organized adlayer of calix[4]arene on a Au(111) surface were achieved by potential-controlled adsorption and in situ STM. In situ STM images revealed that the self-organized molecular array consisted of a calix[4]arene dimer. The two molecules in a cone conformation with a sideways orientation were connected in a “head to head” orientation between the hydroxy groups.
Optically Pumped Quasi-Continuous Wave Violet Vertical Cavity Surface Emitting Lasers (2000)

In this work we have fabricated and studied a violet (λ = 403 nm) VCSEL structures, composed of an InGaN multiple quantum well active medium and a pair of high reflectivity dielectric mirrors. Lasing under high repetition rate (76 MHz) pulsed optical pumping has been achieved at temperatures up to T = 258 K at average pump power of approximately 30 mW.
Direction of arrival by non-coherent arrays (2016)

In previous work we have shown that non-coherent direction of arrival (DOA) estimation by an array of sensors may be implemented from magnitude-only measurements. Here we show that magnitude-only measurements collected by a sensor array may be modeled by a non-central chi-square distribution with mean and variance independent of the phase errors. We also develop a closed-form expression for the Cramer-Rao bound (CRB) of non-coherent DOA estimation for the difference in spatial frequency between two sources. Finally, we obtain closed-form expressions for the maximum likelihood estimates (MLEs) of various unknown parameters. These theoretical expressions are used to analyze the performance of non-coherent DOA estimation.
The Xanthate Route to Indolines, Indoles, and their Aza Congeners (2020)

Convergent routes to a variety of indolines, indoles, oxindoles, and their aza analogues involving radical additions of xanthates are described. Three approaches are summarized. The first is the least general and relies on the generation of aryl or heteroaryl radicals starting from diazonium salts. The second involves radical addition to N-allylanilines followed by ring-closure onto the aromatic core. A large variety of indolines and azaindolines can thus be obtained and, in many cases, converted into the corresponding indoles and azaindoles by various methods. The synthesis of novel fluoroazaindolines and fluoroazaindoles by a rare homolytic ipso-substitution of fluorine atoms is particularly noteworthy. The last approach hinges on the direct modification of indoles by radical addition to the pyrrole subunit of the indole nucleus. Application of this methodology to the total synthesis of melatonin and the alkaloids mersicarpine, caulerpine, and the pentacyclic skeleton of tronocarpine is briefly discussed. Most of the compounds described herein would be difficult to obtain by more traditional routes.
Direct spectroscopic measurement of packaging-induced strains in high-power laser diode arrays (1999)

High-power diode lasers such as `cm-bar arrays' are important for many applications. The `p-side down packaging', i.e. the direct mounting of the epitaxial layer sequence on a heat spreader ensures sufficient thermal properties, however, in such a geometry, additional mechanical strain of the active region represents a central issue, affecting both the laser parameter as well as lifetime and reliability of the device. Thermally induced strain caused by device packaging is studied in high-power semiconductor laser arrays by a novel non-invasive technique. Photocurrent measurements with intentionally strained laser array devices for 808 nm emission reveal spectral shifts of all allowed optical transitions in the active region. These shifts serve as a measure for strain and are compared with model calculations. Depending on the specific heat spreader materials we find compressive or tensile mounting induced strain contributions. For a given packaging architecture, about one quarter of the mounting induced strain is transferred to the quantum well region of the device. Spatially resolved measurements allow to measure lateral strain gradients in the devices. Using this data for calibration we show that polarization resolved electroluminescence scans can be used as convenient measure for strain homogeneity test also in quantum-well devices.