gebhart/patrepeval huggingface dataset:
An In<sub>0.15</sub>Ga<sub>0.85</sub>As/GaAs pseudomorphic single quantum well HEMT (1985)

This letter describes high electron mobility transistors (HEMT's) utilizing a conducting channel which is a single In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.15</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.85</inf> AS quantum well grown pseudomorphically on a GaAs substrate. A Hall mobility of 40 000 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V.s has been observed at 77 K. Shubnikov-de Haas oscillations have been observed at 4.2 K which verify the existence of a two-dimensional electron gas at the In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.15</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.85</inf> As/GaAs interface. HEMT's fabricated with 2-µm gate lengths show an extrinsic transconductance of 90 and 140 mS/mm at 300 and 77 K, respectively-significantly larger than that previously reported for strained-layer superlattice In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf> As structures which are nonpseudomorphic to GaAs substrates. HEMT's with 1-µm gate lengths have been fabricated, which show an extrinsic transconductance of 175 mS/mm at 300 K which is higher than previously reported values for both strained and unstrained In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf> As FET's. The absence of Al <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf> As in these structures has eliminated both the persistent photoconductivity effect and drain current collapse at 77 K.
Role of a Conserved Active Site Cation−π Interaction in <i>Escherichia coli</i> Serine Hydroxymethyltransferase (2009)

Serine hydroxymethyltransferase is a pyridoxal 5'-phosphate-dependent enzyme that catalyzes the interconversion of serine and glycine using tetrahydropteroylglutamate as the one-carbon carrier. In all pyridoxal phosphate-dependent enzymes, amino acid substrates are bound and released through a transaldimination process, in which an internal aldimine and an external aldimine are interconverted via gem-diamine intermediates. Bioinformatic analyses of serine hydroxymethyltransferase sequences and structures showed the presence of two highly conserved residues, a tyrosine and an arginine, engaged in a cation-pi interaction. In Escherichia coli serine hydroxymethyltranferase, the hydroxyl group of this conserved tyrosine (Tyr55) is located in a position compatible with a role as hydrogen exchanger in the transaldimination reaction. Because of the location of Tyr55 at the active site, the enhancement of its acidic properties caused by the cation-pi interaction with Arg235, and the hydrogen bonds established by its hydroxyl group, a role of this residue as acid-base catalyst in the transaldimination process was envisaged. The role played by this cation-pi interaction in the E. coli serine hydroxymethyltransferase was investigated by crystallography and site-directed mutagenesis using Y55F and three R235 mutant forms. The crystal structure of the Y55F mutant suggests that the presence of Tyr55 is indispensable for a correct positioning of the cofactor and for the maintenance of the structure of several loops involved in substrate and cofactor binding. The kinetic properties of all mutant enzymes are profoundly altered. Substrate binding and rapid kinetic experiments showed that both Y55 and R235 are required for a correct progress of the transaldimination reaction.
Inhibition of arachidonate 5-lipoxygenase by phenolic compounds. (1986)

Some cinnamoyl-β-phenethylamine derivatives, gingerols, diarylheptanoids and acyldopamines were tested for their inhibitory effects on the 5-lipoxygenase of RBL-1 cells. Compounds containing a catechol group together with a lipophilic group strongly inhibited 5-lipoxygenase. Significant inhibition was also observed in gingerols having guaiacol instead of catechol. Linoleoyl- and linolenoyl-dopamines were the strongest 5-lipoxygenase inhibitors.
Preparation, characterization and activity of wet‐proofed Pt/silicalite catalysts (1994)

Abstract A procedure for wet‐proofing Pt/silicalite catalysts with polytetrafluoroethylene fibres is described. The procedure yielded catalysts with stable and high activities for the exchange of hydrogen isotopes between liquid water and hydrogen gas. Characterization of the catalysts by hydrogen chemisorption and scanning electron microscopy showed that the wet‐proofing procedure can produce catalysts in which most of the Pt surface in the Pt/silicalite before wet‐proofing can remain accessible. Hydrogen chemisorption was found to be a valuable tool for prescreening of wet‐proofed catalysts.
A Recommendation System of Highway ETC Card Based on Decision Tree Theory (2014)

With the promotion of social information construction and the rapid update and replacement of large capacity storage equipment, the amount of data from every field grows exponentially. Reportedly, the amount of the data accumulated by Shandong Hi-speed Group is very large. These data can satisfy us some daily usefulness, such as query, retrieval, statistics, statements etc. But what is more important is that how can we discover some useful information from the information ocean. This information can be used in real life such as auxiliary decision. This paper is proposed in this historical background. Data mining is a powerful tool for acquiring knowledge from massive data. Some methods of data mining, such as decision tree, support vector machine, Bayesian decision theory, artificial neural network, k-nearest neighbor, association rule mining etc, are commonly used. In this paper, we design a recommendation system of highway ETC card by using the theory of decision tree. The recommendation system can predict whether a car owner is a potential ETC customer or not through the analysis of the vehicle information. Experiments proved that the accuracy rate of the recommendation system is larger than 90%, so it can provide effective information for the extension of China's ETC card.
Bifunctional cytosolic UDP-glucose 4-epimerases catalyse the interconversion between UDP-<scp>D</scp>-xylose and UDP-<scp>L</scp>-arabinose in plants (2009)

UDP-sugars serve as substrates in the synthesis of cell wall polysaccharides and are themselves generated through sequential interconversion reactions from UDP-Glc (UDP-glucose) as the starting substrate in the cytosol and the Golgi apparatus. For the present study, a soluble enzyme with UDP-Xyl (UDP-xylose) 4-epimerase activity was purified approx. 300-fold from pea (Pisum sativum L.) sprouts by conventional chromatography. The N-terminal amino acid sequence of the enzyme revealed that it is encoded by a predicted UDP-Glc 4-epimerase gene, PsUGE1, and is distinct from the UDP-Xyl 4-epimerase localized in the Golgi apparatus. rPsUGE1 (recombinant P. sativum UGE1) expressed in Escherichia coli exhibited both UDP-Xyl 4-epimerase and UDP-Glc 4-epimerase activities with apparent Km values of 0.31, 0.29, 0.16 and 0.15 mM for UDP-Glc, UDP-Gal (UDP-galactose), UDP-Ara (UDP-L-arabinose) and UDP-Xyl respectively. The apparent equilibrium constant for UDP-Ara formation from UDP-Xyl was 0.89, whereas that for UDP-Gal formation from UDP-Glc was 0.24. Phylogenetic analysis revealed that PsUGE1 forms a group with Arabidopsis UDP-Glc 4-epimerases, AtUGE1 and AtUGE3, apart from a group including AtUGE2, AtUGE4 and AtUGE5. Similar to rPsUGE1, recombinant AtUGE1 and AtUGE3 expressed in E. coli showed high UDP-Xyl 4-epimerase activity in addition to their UDP-Glc 4-epimerase activity. Our results suggest that PsUGE1 and its close homologues catalyse the interconversion between UDP-Xyl and UDP-Ara as the last step in the cytosolic de novo pathway for UDP-Ara generation. Alternatively, the net flux of metabolites may be from UDP-Ara to UDP-Xyl as part of the salvage pathway for Ara.
In situ vitrification and removal of lead-based paint for steel structures (1995)

The feasibility of in-situ vitrification of lead oxide contained in red lead based organic coatings was investigated. The removal of organic lead-based primers and paints has been achieved by a flame spray process that uses a glass/ceramic compound designed for high lead solubility and resistance to devitrification. The glass/ceramic compounds were prepared by fusing, fritting, and ball milling to produce the desired powder. The result powder was collected and used to flame spray previously prepared samples containing a commonly used red lead primer. Oxyacetylene flame spray technology was used to apply the glass compound to the steel substrate. The resulting glass waste was collected and analyzed for lead content using Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction analysis. The lead cation leachability rates were determined by the US Environmental Protection Agency (EPA) approved Toxicity Characteristic Leaching Procedure (TCLP). The designer glass waste form that exhibited the best results was a borosilicate glass with iron oxide additions. The iron silicate glass waste form leached approximately 1 ppm of lead during the TCLP, far below the current 5 ppm limit for hazardous waste.
Adhesion improvement of plasma-deposited silica thin films on stainless steel substrate studied by x-ray photoemission spectroscopy and in situ infrared ellipsometry (1998)

Adhesion of plasma-deposited SiO2 on stainless steel is shown to be enhanced after Ar, N2, and NH3 plasma pretreatments of the substrate. Adhesion is related to the chemical bonding at the interface. Therefore, it is studied by x-ray photoemission spectroscopy (XPS) and in situ IR ellipsometry performed on very thin films (≈30 Å thick). IR ellipsometry reveals the removal of adsorbed hydrocarbons on the metallic surface by all plasma treatments. XPS measurements show the removal of NOx species, related to the sample electropolishing, using N2 and NH3 plasmas; in contrast, Ar has practically no effect in this case. Plasma-induced modifications are not limited to surface cleaning. Some nitrogen is incorporated in the substrate after N2 and NH3 plasmas. In particular, nitrogen is found bonded to Si and to Cr after NH3 and N2 treatments, respectively, we interpret the adhesion enhancement by hardening of the substrate surface region in the case of N2 plasma, while, in the case of NH3, it may be related to the formation of silicon nitride. Cr–N–Si linkages between the substrate and the film may also contribute to adhesion improvement. We also observed changes in the early stages of the film growth. A higher sticking coefficient of dissociated species on the surface is revealed after plasma pretreatment. Narrowing of the Si 2p peak in XPS spectra observed in pretreated samples is attributed to a better ordered SiO2 structure at Si sites in terms of bond angles and/or lengths. In contrast, both IR ellipsometry and XPS show no change at O sites.
Image Segmentation Using Deformable Models (2010)

In the past four decades, computerized image segmentation has played an increasingly important role in medical imaging. Segmented images are now used routinely in a multitude of different applications, such as the quantification of tissue volumes [1], diagnosis [2], localization of pathology [3], study of anatomical structure [4, 5], treatment planning [6], partial volume correction of functional imaging data [7], and computer-integrated surgery [8, 9]. Image segmentation remains a difficult task, however, due to both the tremendous variability of object shapes and the variation in image quality (see Fig. 3.1). In particular, medical images are often corrupted by noise and sampling artifacts, which can cause considerable difficulties when applying classical segmentation techniques such as edge detection and thresholding. As a result, these techniques either fail completely or require some kind of postprocessing step to remove invalid object boundaries in the segmentation results. To address these difficulties, deformable models have been extensively studied and widely used in medical image segmentation, with promising results. Deformable models are curves or surfaces defined within an image domain that can move under the influence of internal forces, which are defined within the curve or surface itself, and external forces, which are computed from the image data. The internal forces are designed to keep the model smooth during deformation. The external forces are defined to move the model toward an object boundary or other desired features within an image. By constraining extracted boundaries to be smooth and incorporating other prior information about the object shape, deformable models offer robustness to both image noise and boundary gaps and allow integrating boundary elements into a coherent and consistent mathematical description. Such a boundary description can then be readily used by subsequent applications. Moreover, since deformable models are implemented on the continuum, the resulting boundary representation can achieve subpixel accuracy, a highly desirable property for medical imaging applications. Figure 3.2 shows two examples of using deformable models to extract object boundaries from medical images. The result is a parametric curve in Fig. 3.2(a) and a parametric surface in Fig. 3.2(b).
The Hill equation revisited: uses and misuses (1997)

The Hill coefficient is commonly used to estimate the number of ligand molecules that are required to bind to a receptor to produce a functional effect. However, for a receptor with more than one ligand binding site, the Hill equation does not reflect a physically possible reaction scheme; only under the very specific condition of marked positive cooperativity does the Hill coefficient accurately estimate the number of binding sites. The Hill coefficient is best thought of as an "interaction" coefficient, reflecting the extent of cooperativity among multiple ligand binding sites. Several relatively simple, physically plausible reaction schemes are shown here to produce a variety of ligand dose-response curve phenotypes more appropriately suited to modeling ligand-receptor interactions, especially if independent information about the stochiometry of the ligand-receptor interaction is available.
A CAVITY RING-DOWN SPECTROSCOPY MERCURY CONTINUOUS EMISSION MONITOR (2003)

Previous work on the detection of mercury using the cavity ring-down (CRD) technique has concentrated on the detection and characterization of the desired mercury transition. Interferent species present in flue gas emissions have been tested as well as a simulated flue gas stream. Additionally, work has been done on different mercury species such as the elemental and oxidized forms. The next phase of the effort deals with the actual sampling system. This sampling system will be responsible for acquiring a sample stream from the flue gas stack, taking it to the CRD cavity where it will be analyzed and returning the gas stream to the stack. In the process of transporting the sample gas stream every effort must be taken to minimize any losses of mercury to the walls of the sampling system as well as maintaining the mercury in its specific state (i.e. elemental, oxidized, or other mercury compounds). SRD first evaluated a number of commercially available sampling systems. These systems ranged from a complete sampling system to a number of individual components for specific tasks. SRD engineers used some commercially available components and designed a sampling system suited to the needs of the CRD instrument. This included components such as a pyrolysis oven to convert all forms of mercury to elemental mercury, a calibration air source to ensure mirror alignment and quality of the mirror surfaces, and a pumping system to maintain the CRD cavity pressure from atmospheric pressure (760 torr) down to about 50 torr. SRD also began evaluating methods for the CRD instrument to automatically find the center of a mercury transition. This procedure is necessary as the instrument must periodically measure the baseline losses of the cavity off of the mercury resonance and then return to the center of the transition to accurately measure the mercury concentration. This procedure is somewhat complicated due to the isotopic structure of the 254 nm mercury transition. As a result of 6 isotopes and hyperfine splittings there are 5 individual peaks that can be resolved by the CRD instrument. SRD tested a derivative method with both simulated data and actual data taken with the CRD apparatus. Initial tests indicate that this method is successful in automatically finding the center of the mercury transitions.
Lipoxygenase Products Increase Monocyte Adhesion to Human Aortic Endothelial Cells (1999)

The development of atherosclerosis is accelerated in individuals with type 2 diabetes. Adhesion of monocytes to the vascular endothelium is a key initial step in atherogenesis. We have previously shown that monocyte adhesion to human aortic endothelial cells (HAECs) cultured long-term in high-glucose medium (25 mmol/L, 2 passages) is increased compared with cells grown in normal glucose (5 mmol/L). One potential mechanism for increased monocyte adhesion to HAECs under hyperglycemic conditions is via the 12-lipoxygenase (12-LO) pathway. In this study, we demonstrated in HAECs that the major LO metabolite of arachidonic acid was the 12-LO product, 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE], which was increased severalfold in HAECs cultured under high-glucose conditions. Furthermore, treatment of HAECs with 12(S)-HETE induced monocyte, but not neutrophil, adhesion an average of 3-fold (range of 1.5- to 5-fold) compared with untreated cells (75+/-5 versus 26+/-1 monocytes per field, respectively, P<0.001). Expression of the adhesion molecules vascular cell adhesion molecule-1, E-selectin, and intercellular adhesion molecule-1 was not significantly increased. However, both glucose and 12(S)-HETE induced a 60% increase in HAEC surface expression of connecting segment-1 (ie, CS-1) fibronectin, a ligand for very late-acting antigen-4 (VLA-4). The antibodies used to block monocyte integrin VLA-4 and leukocyte function-related antigen-1, a monocytic counterreceptor for intercellular adhesion molecule-1, inhibited the ability of both 12-LO products and high glucose to induce monocyte adhesion. These results definitively demonstrate for the first time in HAECs that the 12-LO pathway can induce monocyte-endothelial cell interaction and that the effects of glucose may be mediated, at least in part, through this pathway. Thus, these results suggest that the 12-LO pathway may play a role in the increased susceptibility of diabetics to atherosclerosis.
CsI Crystalline Fiber for Infrared Transmission (1980)

We report a melt grown cesium iodide crystalline fiber whose transparency extends from the ultraviolet to infrared region. Transmission losses of the fiber inserted in a teflon jacket are measured at the wavelengths of 0.63 and 10.6 µm, and in the spectral range from 0.8 to 1.6 µm, respectively. Overall optical and mechanical properties of the fiber show its availability.
Classification of speech accents with neural networks (2002)

Several neural network models including competitive learning and counter propagation are developed to identify individuals as either native or non-native speakers based on their accents. Some important speech features, such as pitch period and the first three formant frequencies, are used as inputs to the neural networks. Comparison results based on experiments are also presented. The primary contribution is that it provides a feasible approach for an assisting automatic speech recognition system in an environment in which different English accents may be used.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Formation of epitaxial graphene on SiC(0001) using vacuum or argon environments (2010)

The formation of graphene on the (0001) surface of SiC (the Si-face) is studied by atomic force microscopy, low-energy electron microscopy, and scanning tunneling microscopy/spectroscopy. The graphene forms due to preferential sublimation of Si from the surface at high temperature, and the formation has been studied in both high-vacuum and 1 atm argon environments. In vacuum, a few monolayers of graphene forms at temperatures around 1400 °C, whereas in argon a temperature of about 1600 °C is required in order to obtain a single graphene monolayer. In both cases considerable step motion on the surface is observed, with the resulting formation of step bunches separated laterally by ≳10 μm. Between the step bunches, a layer-by-layer growth of the graphene is found. The presence of a disordered, secondary graphitic phase on the surface of the graphene is also identified.
The Modeling of Carbon Dioxide-Aided Extraction of Carboxylic Acids from Aqueous Solutions (1998)

Carbon dioxide (CO2)-aided acidification of aqueous carboxylate solutions and simultaneous reactive extraction of the carboxylic acid is a promising and clean alternative method for the conventional recovery of carboxylic acids. The complexity of the extraction system is endorsed by the presence of three or four coexisting phases (i.e., vapor−liquid−liquid−(solid)) and an aqueous electrolyte solution. Selection of optimal operating conditions in this complex four-phase system requires a robust, yet simple model for description of the phase equilibria. In this work, such a simple shortcut model is presented. Although the model parameters are obtained from pure component or infinite dilution data only, the model yields a reasonable description with experimental data. Model predictions were compared with experimental data for the CO2-aided extraction of lactic acid with two different amine extractants from various concentrations of a calcium lactate solution and pressures up to 3.1 MPa. The model is expected to be very useful for equipment and process design.