gebhart/patrepeval huggingface dataset:
Preparation and properties of carboxyl‐functional mixed esters of hydrolyzed starch (1978)

Abstract Mixed esters of hydrolyzed starch represent a new class of chemically modified natural polymers demonstrating a broad range of properties. Members of this class of polymers have both neutral aliphatic ester side chains and carboxyl‐functional half‐ester side chains. Use of hydrolyzed starch as the backbone polymer results in products that are considerably lower in molecular weight than whole starch derivatives, but which are still polymeric in character. Synthesis proceeds smoothly in pyridine using anhydrides as acylating agents and the pure solid mixed ester products are isolated by precipitation in water. Measurement of degree of substitution (D.S.) by NMR or hydrolysis characterizes the chemical composition of the polymers. The actual D.S. achieved in the synthesis depends upon the competition between starch and residual water for anhydrides, which can be quantitatively evaluated by monitoring the acid content of the reaction mixture. The T g and T s of starch mixed esters vary with both D. S. and length of the aliphatic ester side chain. As the composition changes from acetate—phthalate to butyrate—phthalate a T g range of greater than 100°C is observed. Hydrolyzed starch mixed esters are hydrophobic and organic‐soluble, but may be readily solubilized in aqueous base through the half‐ester groups. Solutions show surface activity which varies according to the type and extent of substitution.
Mutations in maltose-binding protein that alter affinity and solubility properties (2010)

Maltose-binding protein (MBP) from Escherichia coli has been shown to be a good substrate for protein engineering leading to altered binding (Marvin and Hellinga, Proc Natl Acad Sci U S A 98:4955-4960, 2001a) and increased affinity (Marvin and Hellinga, Nat Struct Biol 8:795-798, 2001b; Telmer and Shilton, J Biol Chem 278:34555-34567, 2003). It is also used in recombinant protein expression as both an affinity tag and a solubility tag. We isolated mutations in MBP that enhance binding to maltodextrins 1.3 to 15-fold, using random mutagenesis followed by screening for enhanced yield in a microplate-based affinity purification. We tested the mutations for their ability to enhance the yield of a fusion protein that binds poorly to immobilized amylose and their ability to enhance the solubility of one or more aggregation-prone recombinant proteins. We also measured dissociation constants of the mutant MBPs that retain the solubility-enhancing properties of MBP and combined two of the mutations to produce an MBP with a dissociation constant 10-fold tighter than wild-type MBP. Some of the mutations we obtained can be rationalized based on the previous work, while others indicate new ways in which the function of MBP can be modified.
Radiative cooling for solar cells (2015)

Standard solar cells heat up under sunlight, and the resulting increased temperature of the solar cell has adverse consequences on both its efficiency and its reliability. We introduce a general approach to radiatively lower the operating temperature of a solar cell through sky access, while maintaining its sunlight absorption. We present first an ideal scheme for the radiative cooling of solar cells. For an example case of a bare crystalline silicon solar cell, we show that the ideal scheme can passively lower the operating temperature by 18.3 K. We then show a microphotonic design based on realistic material properties, that approaches the performance of the ideal scheme. We also show that the radiative cooling effect is substantial, even in the presence of significant non-radiative heat change, and parasitic solar absorption in the cooling layer, provided that we design the cooling layer to be sufficiently thin.
A high saturation output power (+22 dBm) polarization insensitive semiconductor optical amplifier (2005)

We developed a broadband polarization insensitive SOA using a strained MQW active layer. A record-high saturation output power of +22 dBm was obtained with a low polarization sensitivity of < 0.3 dB at 1550 nm.
Passive ice freezing-releasing heat pipe. [Patent application] (1980)

A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.
Low Temperature Direct 2-Propanol Fuel Cells (2002)

2-Propanol exhibits a substantially higher cell voltage than methanol in a direct liquid fuel cell at a current density less than ca. <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="ML1" overflow="scroll"> <mml:mn>100</mml:mn> <mml:mo> </mml:mo> <mml:mi mathvariant="normal">mA</mml:mi> <mml:mo>/</mml:mo> <mml:msup> <mml:mi mathvariant="normal">cm</mml:mi> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo>.</mml:mo> </mml:math> Although the performance increases with cell temperature, the cell can deliver 690 mV at a current density of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="ML2" overflow="scroll"> <mml:mn>20</mml:mn> <mml:mo> </mml:mo> <mml:mi mathvariant="normal">mA</mml:mi> <mml:mo>/</mml:mo> <mml:msup> <mml:mi mathvariant="normal">cm</mml:mi> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> at room temperature. These features could make 2-propanol an attractive fuel for portable power applications. © 2002 The Electrochemical Society. All rights reserved.
Synthetic high-density lipoprotein-like nanoparticles for cancer therapy (2014)

High-density lipoproteins (HDLs) are a diverse group of natural nanoparticles that are most well known for their role in cholesterol transport. However, HDLs have diverse functions that provide significant opportunities for cancer therapy. Presented is a focused review of the ways that synthetic versions of HDL have been used as targeted therapies for cancer, and as vehicles for the delivery of diverse therapeutic cargo to cancer cells. As such, synthetic HDLs are likely to play a central role in the development of next-generation cancer therapies.
Development of a passive and remote magnetic microsensor with thin-film giant magnetoimpedance element and surface acoustic wave transponder (2011)

This paper presents the development of a wireless magnetic field sensor consisting of a three-layer thin-film giant magnetoimpedance sensor and a surface acoustic wave device on one substrate. The goal of this integration is a passive and remotely interrogated sensor that can be easily mass fabricated using standard microfabrication tools. The design parameters, fabrication process, and a model of the integrated sensor are presented together with experimental results of the sensor.
Self-driven AC-DC synchronous rectifier for power applications: A direct energy-efficient replacement for traditional diode rectifier (2010)

Synchronous rectification has previously been adopted in switched mode circuits for reducing the conduction losses particularly in low-voltage and high-current applications. This paper presents a generalized ¿self-driven¿ AC-DC synchronous rectification technique that can be used to develop AC-DC synchronous rectifier that behaves like a diode bridge, but with much reduced conduction losses and without control integrated circuits. This generalized concept can be extended from single-phase to multi-phase systems. Experiments based on 1 kW and 2 kW single-phase systems have been successfully conducted for capacitive, inductive and resistive loads. Very significant power loss reduction (over 50%) has been achieved in the rectification stage at both 110 V and 220 V AC mains operations. This patent-pending circuit can be regarded as a direct replacement of general-purpose diode rectifier. Due to the reduction of power loss, further reduction in the size and cost of the heatsink or thermal management for the power circuit becomes possible.
Broadband, efficient, and robust quasi-parametric chirped-pulse amplification (2017)

Quasi-parametric chirped pulse amplification (QPCPA) is a new scheme that enables the amplification of chirped signal pulses without back conversion by depleting the idler pulses. In this paper, we present a numerical study on the bandwidth, efficiency, and robustness of QPCPA. Self-locked phase among the interacting waves is found to be the underlying mechanism for the suppression of back conversion, which allows signal efficiency approaching to the quantum limit even under the phase-mismatch condition, and thus greatly increases the phase-mismatch tolerance of QPCPA. We demonstrate that QPCPA can break through the trade-off between the efficiency and bandwidth encountered in conventional optical parametric amplification, hence supporting highly efficient amplification of few-cycle pulses.
Steep subthreshold slope nanoelectromechanical field-effect transistors with nanowire channel and back gate geometry (2013)

Significant physical challenges remain for CMOS technology to increase I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> and decrease I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> as transistor dimension and power supply voltages continue downscaling. For I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> , a physical barrier exists as exhibited in the subthreshold slope SS = |(∂V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> )/(∂lnI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> )| = ln10·k <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> T/q, which is limited to > 60 mV/dec at room temperature due to electron thermal distribution. To circumvent this fundamental thermodynamical limit, we have designed the first integration of semiconductor nanowires (NWs) and nanoelectromechanical system (NEMS) field effect transistor structure (NW-NEMFET). We have previously demonstrated 0.5 ps intrinsic delay and near ballistic operation in quantum confined semiconductor heterostructure NWFETs with diameters less than 15 nm.[1] The current design uses high performance suspended semiconductor NWs as the conduction channel, while the electrostatic pull-in of the NW towards the gate stack enables abrupt switching to the off-state leading to high frequency, low power nanoelectronics. We show that compared to planar suspended-gate FET (SGFET) design [2], NW-NEMFET allows zero SS with 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> on-off ratio and near 1 V pull-in voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pi</sub> ) due to enhanced 3D capacitive coupling, as well as operation at very-high-frequency (VHF) and even ultra-high-frequency (UHF) due to the NW beams' extremely high aspect ratio and small dimensions. [3] Fabrication and characterization of will be discussed.
Nonhysteretic Phenomena in the Metal–Semiconductor Phase-Transition Loop of $\hbox{VO}_{2}$ Films for Bolometric Sensor Applications (2010)

Hysteresis observed in the resistive semiconductor-to-metal phase transition in VO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> causes problems in bolometric readout, and thus is an obstacle in utilizing this strong phase transition in bolometric sensor applications. It is possible to avoid the unwanted hysteresis when operating in limited temperature ranges within the hysteresis loop of VO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . Nonhysteretic branches (NHB-s) traced in such limited temperature intervals turned out to have much higher temperature coefficient of resistance (TCR) than VO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> at room temperature: while TCR at 25° C in VO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> is close to 3%, peak TCR values in NHB-s reach 6% in VO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> films on Si/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> substrates and 21% in films on crystalline sapphire substrates. At the same time, the nanoscopic-scale mixture of semiconducting and metallic phases in VO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> within its hysteresis loop provides for partially shunted low resistivity, thus creating an unprecedented combination of record high semiconducting TCR and metal-like low resistance. This combination may benefit the uncooled focal plane array microbolometer IR visualization technology.
Ethionamide activation and sensitivity in multidrug-resistant <i>Mycobacterium tuberculosis</i> (2000)

Ethionamide (ETA) is an important component of second-line therapy for the treatment of multidrug-resistant tuberculosis. Synthesis of radiolabeled ETA and an examination of drug metabolites formed by whole cells of Mycobacterium tuberculosis (MTb) have allowed us to demonstrate that ETA is activated by S-oxidation before interacting with its cellular target. ETA is metabolized by MTb to a 4-pyridylmethanol product remarkably similar in structure to that formed by the activation of isoniazid by the catalase-peroxidase KatG. We have demonstrated that overproduction of Rv3855 (EtaR), a putative regulatory protein from MTb, confers ETA resistance whereas overproduction of an adjacent, clustered monooxygenase (Rv3854c, EtaA) confers ETA hypersensitivity. Production of EtaA appears to be negatively regulated by EtaR and correlates directly with [(14)C]ETA metabolism, suggesting that EtaA is the activating enzyme responsible for thioamide oxidation and subsequent toxicity. Coding sequence mutations in EtaA were found in 11 of 11 multidrug-resistant MTb patient isolates from Cape Town, South Africa. These isolates showed broad cross-resistance to thiocarbonyl containing drugs including ETA, thiacetazone, and thiocarlide.
Species-Dependent Variability of ADAMTS-13 Mediated Proteolysis of Human Recombinant von Willebrand Factor. (2007)

Abstract ADAMTS-13 is a plasma metalloprotease that regulates platelet adhesion and aggregation through cleavage of von Willebrand factor (VWF) multimers within the A2 domain between residues tyrosine 1605 and methionine 1606. Genetic (Upshaw-Schulman syndrome) and acquired severe functional defects of ADAMTS-13 are associated with the presence of non-proteolysed ultra-large VWF multimers. These multimers are the most thrombogenic form of this molecule and spontaneously bind to platelets causing thrombotic thrombocytopenic purpura (TTP), a syndrome characterized by microvascular thrombosis and platelet consumption. We investigated proteolysis of human rVWF by ADAMTS-13 present in plasma of different species typically used as preclinical animal models. Our substrate was a recombinant, Chinese hamster ovary (CHO) cell line-derived rVWF, processed to mature rVWF by exposure to rfurin and highly purified by a series of chromatography steps. Multimer analysis of rVWF shows absence of satellite bands consistent with intact subunits not cleaved by ADAMTS-13. rVWF was incubated with BaCl2-activated plasma samples from different species, 4 hours at 37°C with urea. ADAMTS-13-mediated degradation of VWF was measured by collagen binding (CB) assay and proteolysis visualized by high-resolution multimer analysis stained with a polyclonal anti-human VWF antibody and by non-reducing SDS-PAGE, followed by immunoblotting with a polyclonal anti-human VWF antibody. Incubation of rVWF with normal human plasma resulted in the loss of collagen binding activity and disappearance of high molecular weight multimers with simultaneous formation of the specific satellite bands leading to a multimeric pattern similar to pdVWF. In contrast, using the same amount of animal plasma (50 mU/ml human-equivalent concentration), differences were found in the ADAMTS-13 activity levels in terms of the degree of proteolytic degradation of rVWF multimers as follows as measured by CBA: Mouse plasma samples from wild type or from mice lacking FVIII and VWF, all with a C57BL/6J background, showed no ADAMTS-13 activity towards human rVWF. No activities were observed in rat and guinea pig plasma. Porcine plasma showed only minimal activity. Samples from monkey strains (baboon, rhesus and cynomolgus) and from beagle dogs showed medium activities with a residual CB of 60%. Rabbit plasma was as effective as human plasma in cleaving and degrading VWF resulting in a residual CB of 20%. The quantitative results were confirmed by multimer visualization. We conclude that animal plasma differs markedly in plasma ADAMTS-13 activity and capacity to cleave human VWF multimers. Our study confirms previous in vivo studies with human rVWF where no proteolysis was seen in mice, and little proteolysis was observed in dogs (Turecek et al., Blood 1997) and pigs (Roussi J et al. Blood.Coag.Fibrinol. 1998). The present study also suggests caution is needed in interpreting the (patho)physiology and metabolism of human VWF from animal models.
A counter-based all-digital spread-spectrum clock generator with high EMI reduction in 65nm CMOS (2013)

An all-digital spread-spectrum clock generator (ADSSCG) with direct modulation on the digitally controlled oscillator (DCO) is presented. The proposed ADSSCG can generate an accurate triangular modulation on the output frequency, and thus it can achieve high electromagnetic interference (EMI) reduction with a smaller spreading ratio as compared with existing designs. In addition, the proposed frequency counter-based mechanism can maintain the long-term frequency stability of the ADSSCG. The proposed ADSSCG is implemented in a standard performance 65nm CMOS process, the active area is 85μm × 85μm. It consumes 163.9μW at 270MHz with a 1.0V power supply. The EMI reduction of the proposed ADSSCG is 13.99dB with a 0.5% spreading ratio at 270MHz, and 20.23dB EMI reduction is achieved with a 1.5% spreading ratio at 162MHz. Moreover, the proposed ADSSCG is designed with standard cells, and thus it can be ported to different process in a short time.
Supramolecular Chirogenesis in Bis(zinc porphyrin):  An Absolute Configuration Probe Highly Sensitive to Guest Structure (2000)

The role of the ligand's structure and absolute configuration in the supramolecular chirality induction in achiral bis(zinc porphyrin) has been studied. The amines with bulkier substituents resulted in stronger CD signals due to increased helical displacement in the anti conformer. All the amines with an R absolute configuration gave a negative first Cotton effect and positive second Cotton effect, while the ligands with an S absolute configuration produced CD signals with opposite signs due to formation of the left- and right-handed screw diastereomers, respectively.
ChemInform Abstract: Re‐synthesis and Electrochemical Characteristics of LiFePO<sub>4</sub> Cathode Materials Recycled from Scrap Electrodes. (2013)

Abstract LiFePO 4 active cathode material is recovered from scrap electrodes of lithium secondary batteries by an environmentally friendly thermal treatment method at 500 °C for 30 min under flowing nitrogen.
Development and Characterization of Chicken-Chicken B Cell Hybridomas Secreting Monoclonal Antibodies that Detect Sporozoite and Merozoite Antigens of Eimeria (1994)

Chicken-chicken B cell hybridomas that secrete monoclonal antibodies (mAb) detecting antigens located at the anterior tip of the sporozoites of Eimeria acervulina have been produced. Peripheral blood lymphocytes (PBL) obtained from chickens infected with E. acervulina were fused with a thymidine-kinase deficient (TK-) chicken B cell line. Hybridomas secreting mAb binding to the sporozoite antigens of E. acervulina were selected using an ELISA. Two stable hybridomas, whose mAb were designated as P11 and P66, respectively, were obtained and their binding characteristics were assessed. The mAb P11 detects the sporozoite but not the merozoite antigens of E. acervulina and Eimeria tenella. The P66 mAb recognizes a cross-reactive antigen of sporozoite and merozoite of E. acervulina but not E. tenella. Flow cytometric analysis of the hybridomas secreting the P11 and P66 mAb showed expression of surface IgM and IgG, respectively. Western blot analysis under reducing conditions showed that mAb P11 recognized a sporozoite protein of 43 kDa. Both mAb recognized antigens located at the anterior end of the sporozoites by indirect immunofluorescence staining. This study shows the development of chicken B cell hybridomas that secrete coccidia-specific mAb.
Image processing and analysis in a dual-modality optoacoustic/ultrasonic system for breast cancer diagnosis (2011)

Coregistered optoacoustic (OA) and ultrasound (US) images obtained using a dual modality optoacoustic/ultrasonic breast imaging system are used together for enhanced diagnostic capabilities in comparison to each individual technology. Therefore, an operator-independent delineation of diagnostically relevant objects (in our case breast tumors) with subsequent automatic analysis of image features is required. We developed the following procedure: 1) Image filtering is implemented on a US image to minimize speckle noise and simultaneously preserve the sharpness of the boundaries of the extended objects; 2) Boundaries of the objects of interest are automatically delineated starting with an initial guess made by an operator; 3) Both US and OA images are analyzed using the detected boundaries (contrast, boundary sharpness, homogeneity of the objects and background, boundary morphology parameters are calculated). Calculated image characteristics can be used for statistically independent evaluation of structural information (US data) and vascularization (OA data) of the studied breast tissues. Operator-independent delineation of the objects of interest (e.g. tumors and blood vessels) is essential in clinical OA spectroscopy (using multiple laser wavelengths to quantify concentrations of particular tissue chromophores, such as oxy- and deoxy- hemoglobin, water, and lipids). Another potential application of the suggested image analysis algorithm could be in OA imaging system design, when system performance should be evaluated in terms of quality of the images reconstructed from the well-defined objects of interest. The discussed principles of image analysis are illustrated by using real clinical US and OA data.
Facilitated carbon dioxide reduction using a Zn(<scp>ii</scp>) complex (2015)

Two new Zn(II) complexes have been prepared and evaluated for their capacity to activate and reduce CO2. The electrochemical properties of dichlorobis[diphenyl-(2-pyridyl)phosphine-κ(1)-N]zinc(II) [corrected]. and dichloro[diphenyl-(2-pyridyl)phosphine-κ(1)-N]zinc(II) 2 are compared using cyclic voltammetry. Electrochemical results indicate that 2 leads to a facilitated CO2 reduction to evolve CO at a glassy carbon electrode.
Oxazine Ether Herbicides (1995)

Benzylic ethers of oxazine-6-methanols are very effective grass herbicides which show safety to a number of major crops. We have found 2 different synthetic routes to these compounds. The first route is based on the reaction of nitroso-olefins with allylic alcohols. The second route relies on a novel reaction of oxime dianions with chloro-epoxides. We will describe our studies on the discovery and optimization of these syntheses and the biology of the oxazine ethers.