gebhart/patrepeval huggingface dataset:
Response of nicotianamine synthase activity to Fe-deficiency in tobacco plants as compared with barley (1995)

In vitro nicotianamine synthase activity was measured in tobacco under Fe-deficient or Fe-sufficient conditions. Its activity was not induced by Fe-deficiency, in contrast to barley roots, implying that the molecular biological regulation of nicotianamine synthase in response to Fe-deficiency may be different between tobacco and barley.
Coarray Tensor Direction-of-Arrival Estimation (2023)

Augmented coarrays can be derived from spatially undersampled signals of sparse arrays for underdetermined direction-of-arrival (DOA) estimation. With the extended dimension of sparse arrays, the sampled signals can be modeled as sub-Nyquist tensors, thereby enabling coarray tensor processing to enhance the estimation performance. The existing methods, however, are not applicable to generalized multi-dimensional sparse arrays, such as sparse planar array and sparse cubic array, and have not fully exploited the achievable source identifiability. In this paper, we propose a coarray tensor DOA estimation algorithm for multi-dimensional structured sparse arrays and investigate an optimal coarray tensor structure for source identifiability enhancement. Specifically, the cross-correlation tensor between sub-Nyquist tensor signals is calculated to derive a coarray tensor. Based on the uniqueness condition for coarray tensor decomposition, the achievable source identifiability is analysed. Furthermore, to enhance the source identifiability, a dimension increment approach is proposed to embed shifting information in the coarray tensor. The shifting-embedded coarray tensor is subsequently reshaped to optimize the source identifiability. The resulting maximum number of degrees-of-freedom is theoretically proved to exceed the number of physical sensors. Hence, the optimally reshaped coarray tensor can be decomposed for underdetermined DOA estimation with closed-form solutions. Simulation results demonstrate the effectiveness of the proposed algorithm in both underdetermined and overdetermined cases.
Rationally Dispersed Molybdenum Phosphide on Carbon Nanotubes for the Hydrogen Evolution Reaction (2018)

Molybdenum phosphide (MoP) is viewed as a potential electrocatalyst for the electrochemical hydrogen evolution reaction (HER). However, crystallization of MoP occurs at rather high temperature (>600 °C). At this temperature, coalescence and agglomeration, which affect the performance severely, become inevitable. Herein, an oxalate-guided nonhydrolytic method is demonstrated for the preparation of MoP with smaller particle size and better dispersion qualities onto the surface of carbon nanotubes (CNTs). Molybdenum is coordinated with the oxalate group using oxalic acid, which modifies the self-assembling of molybdenum at the molecular level and renders discrete nucleation and growth of MoP on CNTs. Phosphoric acid (crystalline) was used as a source of phosphorus. The method is simple with the potential to scale-up. A probable mechanism for the growth of MoP on CNTs is proposed. The as-derived MoP/CNT electrode exhibits excellent performance, outperforming most of the MoP-based electrocatalysts, for hydrogen evolution in both acidic and basic media. In addition, the electrode possesses excellent stability. The higher performance of the electrode is rationalized in terms of small particle size with uniform dispersion, high specific and electrochemically active surface area, electrical conductivity, interfacial charge transfer kinetics, and turnover frequency. Estimation of Tafel slope is consistent with electrochemical desorption of hydrogen gas following the Volmer–Heyrovsky mechanism as the rate-determining step.
Hydroboration. 86. Convenient conversion of aldehydes and ketones into the corresponding alkenes via hydroboration of their enamines. A remarkably simple synthesis of either (Z)- or (E)-alkenes (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydroboration. 86. Convenient conversion of aldehydes and ketones into the corresponding alkenes via hydroboration of their enamines. A remarkably simple synthesis of either (Z)- or (E)-alkenesBakthan Singaram, Milind V. Rangaishenvi, Herbert C. Brown, Christian T. Goralski, and Dennis L. HashaCite this: J. Org. Chem. 1991, 56, 4, 1543–1549Publication Date (Print):February 1, 1991Publication History Published online1 May 2002Published inissue 1 February 1991https://pubs.acs.org/doi/10.1021/jo00004a038https://doi.org/10.1021/jo00004a038research-articleACS PublicationsRequest reuse permissionsArticle Views887Altmetric-Citations40LEARN 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-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Effects of 7-O Substitutions on Estrogenic and Anti-Estrogenic Activities of Daidzein Analogues in MCF-7 Breast Cancer Cells (2010)

Daidzein (1) is a natural estrogenic isoflavone. We report here that 1 can be transformed into anti-estrogenic ligands by simple alkyl substitutions of the 7-hydroxyl hydrogen. To test the effect of such structural modifications on the hormonal activities of the resulting compounds, a series of daidzein analogues have been designed and synthesized. When MCF-7 cells were treated with the analogues, those resulting from hydrogen substitution by isopropyl (3d), isobutyl (3f), cyclopentyl (3g), and pyrano- (2) inhibited cell proliferation, estrogen-induced transcriptional activity, and estrogen receptor (ER) regulated progesterone receptor (PgR) gene expression. However, methyl (3a) and ethyl (3b) substitutions of the hydroxyl proton only led to moderate reduction of the estrogenic activities. These results demonstrated the structural requirements for the transformation of daidzein from an ER agonist to an antagonist. The most effective analogue, 2, was found to reduce in vivo estrogen stimulated MCF-7 cell tumorigenesis using a xenograft mouse model.
Standoff 3D Gamma-Ray Imaging (2009)

We present a new standoff imaging technique able to provide 3-dimensional (3D) images of gamma-ray sources distributed in the environment. Unlike standard 3D tomographic methods, this technique does not require the radioactive sources to be bounded within a predefined physical space. In the present implementation, the gamma-ray imaging system is based on two large planar HPGe double sided segmented detectors, which are used in a Compton camera configuration. A LIDAR system is used in conjunction with the gamma-ray imaging system to confine the gamma-ray image space to the interior of physical objects situated within the detection range of the gamma-ray imager. This approach results in superior image contrast and efficient image reconstruction. Results demonstrating the operating principle are reported.
Investigation of Lithium Tetrafluorooxalatophosphate as a Lithium-Ion Battery Electrolyte (2009)

A lithium tetrafluorooxalatophosphate [LiPF4 (C2 O4)] salt, was prepared and its properties as a lithium-ion battery electrolyte were investigated. The conductivity, electrochemical stability, and cycling performance of 1.0 M LiPF4 (C2 O4) in 1:1:1 ethylene carbonate/dimethyl carbonate/diethyl carbonate are comparable to the industry standard LiPF6 electrolyte. While the reversible capacity of the first cycle is lower than LiPF6 -based electrolytes, the reversible cycling efficiency is equivalent. Electrochemical impedance spectroscopy and electrode surface analysis provide insight into the differences between LiPF6 and LiPF4 (C2 O4). © 2009 The Electrochemical Society.
Rapid prototyping fabrication of focused ultrasound transducers (2014)

Rapid prototyping (RP) fabrication techniques are currently widely used in diverse industrial and medical fields, providing substantial advantages in development time and costs in comparison to more traditional manufacturing processes. This paper presents a new method for the fabrication of high-intensity focused ultrasound transducers using RP technology. The construction of a large-aperture hemispherical transducer designed by computer software is described to demonstrate the process. The transducer was conceived as a modular design consisting of 32 individually focused 50.8-mm (2-in) PZT-8 element modules distributed in a 300-mm hemispherical scaffold with a geometric focus of 150 mm. The entire structure of the array, including the module housings and the hemispherical scaffold was fabricated through a stereolithography (SLA) system using a proprietary photopolymer. The PZT elements were bonded to the lenses through a quarter-wave tungsten-epoxy matching layer developed in-house specifically for this purpose. Modules constructed in this manner displayed a high degree of electroacoustic consistency, with an electrical impedance mean and standard deviation of 109 ± 10.2 Ω for the 32 elements. Time-of-flight measurements for individually pulsed modules mounted on the hemispherical scaffold showed that all pulses arrived at the focus within a 350 ns range, indicating a good degree of element alignment. Pressure profile measurements of the fully assembled transducer also showed close agreement with simulated results. The measured focal beam FWHM dimensions were 1.9 × 4.0 mm (1.9 × 3.9 mm simulated) in the transversal and axial directions respectively. Total material expenses associated with the construction of the transducer were approximately 5000 USD (as of 2011). The versatility and lower fabrication costs afforded by RP methods may be beneficial in the development of complex transducer geometries suitable for a variety of research and clinical applications.
Coupled Hemodynamic-Biochemical Modeling of Thrombus For- mation in Infarcted Left Ventricles 1 JUNG HEE SEO, VIJAY VEDULA, (2013)

heart failure (HF) and left ventricular (LV) systolic dysfunction have higher rates of thromboembolic events including embolic stroke and peripheral arterial thrombi. A common cause of arterial emboli in HF patients is myocardial infarction (MI) and subsequent left ventricular thrombus (LVT) formation. Stagnation of blood and endocardial injury are hypothesized to promote the development of LVT. The identification of high risk patients and the pharmacologic prevention of LVT formation are the keys to preventing embolic events. Stratification of patients at risk for LVT formation is currently limited, and primarily based on global assessment of ventricular function and image based assessment of ventricular wall motion. In this study, we explore a method to predict LVT risk using a multi-physics computational model. The blood flow in the left ventricle is simulated by solving the incompressible Navier-Stokes equation using an immersed boundary method and this is coupled to a convection-diffusion-reaction equation based model of platelet activation and coagulation. The results are then correlated with the other hemodynamic metrics such as wall shear stress and residence time to develop quantitative metrics for the LVT risk prediction.
Afterpulsing and instability in superconducting nanowire avalanche photodetectors (2012)

We investigated the reset time of superconducting nanowire avalanche photodetectors (SNAPs) based on 30 nm wide nanowires. We studied the dependence of the reset time of SNAPs on the device inductance and discovered that SNAPs can provide a speed-up relative to superconducting nanowire single-photon detectors with the same area but with some limitations: (1) Reducing the series inductance of SNAPs (necessary for the avalanche formation) could result in the detectors operating in an unstable regime, (2) a trade-off exists between maximizing the bias current margin and minimizing the reset time of SNAPs, and (3) reducing the reset time of SNAPs below ∼1 ns resulted in afterpulsing.
Platelet‐ and macrophage‐derived endogenous cannabinoids are involved in endotoxin‐induced hypotension (1998)

Macrophages are the primary cellular targets of bacterial lipopolysaccharide (LPS), but the role of macrophage-derived cytokines in LPS-induced septic shock is uncertain. Recent evidence indicates that activation of peripheral CB1 cannabinoid receptors contributes to hemorrhagic hypotension and that macrophage-derived anandamide as well as unidentified platelet-derived substances may be contributing factors. Here we demonstrate that rat platelets contain the endogenous cannabinoid 2-arachidonyl glyceride (2-AG), as identified by reverse phase high-performance liquid chromatography, gas chromatography, and mass spectrometry, and that in vitro exposure of platelets to LPS (200 microg/ml) markedly increases 2-AG levels. LPS-stimulated, but not control, macrophages contain anandamide, which is undetectable in either control or LPS-stimulated platelets. Prolonged hypotension and tachycardia are elicited in urethane-anesthetized rats treated 1) with LPS (15 mg/kg i.v.); 2) with macrophages plus platelets isolated from 3 ml of blood from an LPS-treated donor rat; or 3) with rat macrophages or 4) platelets preincubated in vitro with LPS (200 microg/ml). In all four cases, the hypotension but not the tachycardia is prevented by pretreatment of the recipient rat with the CB1 receptor antagonist SR141716A (3 mg/kg i.v.), which also inhibits the hypotensive response to anandamide or 2-AG. The hypotension elicited by LPS-treated macrophages or platelets remains unchanged in the absence of sympathetic tone or after blockade of nitric oxide synthase. These findings indicate that platelets and macrophages generate different endogenous cannabinoids, and that both 2-AG and anandamide may be paracrine mediators of endotoxin-induced hypotension via activation of vascular CB1 receptors.
Nondestructive imaging of fiber structure in articular cartilage using optical polarization tractography (2016)

Collagen fiber orientation plays an important role in determining the structure and function of the articular cartilage. However, there is currently a lack of nondestructive means to image the fiber orientation from the cartilage surface. The purpose of this study is to investigate whether the newly developed optical polarization tractography (OPT) can image fiber structure in articular cartilage. OPT was applied to obtain the depth-dependent fiber orientation in fresh articular cartilage samples obtained from porcine phalanges. For comparison, we also obtained collagen fiber orientation in the superficial zone of the cartilage using the established split-line method. The direction of each split-line was quantified using image processing. The orientation measured in OPT agreed well with those obtained from the split-line method. The correlation analysis of a total of 112 split-lines showed a greater than 0.9 coefficient of determination (R2) between the split-line results and OPT measurements obtained between 40 and 108???m in depth. In addition, the thickness of the superficial layer can also be assessed from the birefringence images obtained in OPT. These results support that OPT provides a nondestructive way to image the collagen fiber structure in articular cartilage. This technology may be valuable for both basic cartilage research and clinical orthopedic applications.
Increased expression of cSHMT, Tbx3 and utrophin in plasma of ovarian and breast cancer patients (2005)

Plasma samples of ovarian and breast cancer patients were used to search for markers of cancer using 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry. Truncated forms of cytosolic serine hydroxymethyl transferase (cSHMT), T-box transcription factor 3 (Tbx3) and utrophin were aberrantly expressed in samples from cancer patients as compared to samples from noncancerous cases. Aberrant expression of proteins was validated by immunoblotting of plasma samples with specific antibodies to cSHMT, Tbx3 and utrophin. A cohort of 79 breast and 39 ovarian cancer patients and 31 individuals with noncancerous conditions was studied. We observed increased expression of truncated cSHMT, Tbx3 and utrophin in plasma samples obtained from patients at early stages of disease. Our data suggest that cSHMT, Tbx3 and utrophin can be used as components of multiparameter monitoring of ovarian and breast cancer (supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html).
A general joint component framework for realistic articulation in human characters (2003)

We present a general joint component framework model that is capable of exhibiting complex behavior of joints in articulated figures. The joints are capable of handling non-orthogonal, non-intersecting axes of rotation and changing joint centers that are often found in the kinematics of real anatomical joints. The adjustment of joint articulation is done with a relatively small set of intuitive parameters compared to the number of articulations in the motions they parameterize. This is done by making various linear and nonlinear joint dependencies implicit within our framework. An animator is restricted from putting the skeleton in an infeasible pose. We have used our joint framework model to successfully model highly-articulated complex joints such as the human spine and shoulder.
Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties (2000)

An enzymatic method to graft hexyloxyphenol onto the biopolymer chitosan was studied. The method employs tyrosinase to convert the phenol into a reactive o-quinone, which undergoes subsequent nonenzymatic reaction with chitosan. Reactions were conducted under heterogeneous conditions using chitosan films and also under homogeneous conditions using aqueous methanolic mixtures capable of dissolving both hexyloxyphenol and chitosan. Tyrosinase was shown to catalyze the oxidation of hexyloxyphenol in such aqueous methanolic solutions. Chemical evidence for covalent grafting onto chitosan was provided by three independent spectroscopic approaches. Specifically, enzymatic modification resulted in (1) the appearance of broad absorbance in the 350-nm region of the UV/vis spectra for chitosan films; (2) changes in the NH bending and stretching regions of chitosan's IR spectra; and (3) a base-soluble material with 1H-NMR signals characteristic of both chitosan and the alkyl groups of hexyloxyphenol. Hexyloxyphenol modification resulted in dramatic changes in chitosan's functional properties. On the basis of contact angle measurements, heterogeneous modification of a chitosan film yielded a hydrophobic surface. Homogeneously modified chitosan offered rheological properties characteristic of associating water-soluble polymers. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 70: 564–573, 2000.
Use of radiation-induced polymers in cement slurries. [fluid loss control] (1976)

Water loss from cement slurries is reduced by incorporating within a cement slurry a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in 10-60 percent aqueous monomer solution with gamma radiation. The aqueous monomer solution preferably contains 25-99 percent acrylamide and 75-1 percent sodium acrylate. The polymer can be present in concentration of about 0.001 to about 3.0 weight percent, based on the aqueous phase of the slurry. (auth)
Transcutaneous electrical muscle stimulation for the treatment of progressive spinal curvature deformities (1984)

Transcutaneous electrical muscle stimulation has been used to treat spinal curvature. Electrically induced muscle contractions cause partial straightening of the spinal column while the patients sleep. Long-term treatment of 107 patients with progressive idiopathic scoliosis shows a 93% success rate in preventing further progression for curves below 30 degrees while the rate drops to 73% for curves above 30 degrees. In non-idiopathic scoliosis the outcome varied with aetiology and curve magnitude. All kyphosis patients stopped progression.
Fermat photons in turbid media: an exact analytic solution for most favorable paths—a step toward optical tomography (1995)

Photon propagation in a turbid medium characterized by highly forward-directed light scattering can be described by a generalized Fermat principle, a counterpart of the conventional Fermat principle for transparent media. An exact analytic solution for the most favorable photon paths (Fermat paths) has been found and is investigated. An analysis intended to encourage and facilitate experimental observation of Fermat photons is presented. The feasibility of using the theory in time-resolved optical tomography for the recognition of objects hidden in turbid media is discussed.
Image-based Measurement of Phase Transfer Function (2010)

A method for measuring the Phase Transfer Function (PTF) from a high-contrast edge image is proposed and the advantages of utilizing the knowledge of PTF in computational, sparse aperture and multiplexed imaging are discussed.
A Novel Low Pt Loading, High CO Tolerance Fuel Cell Electrocatalyst (2001)

A new method for the preparation of Pt-Ru and similar bimetallic electrocatalysts is reported. It involves a spontaneous deposition of Pt submonolayers on metallic Ru nanoparticles, which yields electrocatalysts with a considerably lower Pt loading and higher CO tolerance than the commercial Pt-Ru alloy electrocatalysts. The method offers a unique possibility to place the Pt atoms onto the surface of Ru nanoparticles, which very likely makes almost all of them available for hydrogen oxidation, in contrast to the Pt-Ru alloy catalysts that have Pt throughout the nanoparticles. Thus, an ultimate reduction of Pt loading can be achieved. It also facilitates a fine-tuning of the electrocatalyst’s activity and selectivity by changing the coverage ~the cluster size! of Pt for optimal performance under required CO tolerance levels. © 2001 The Electrochemical Society. @DOI: 10.1149/1.1414943# All rights reserved.
Effects of Active Flow Control on Fan-In-Wing Aerodynamic Performance In Hover and Forward Flight (2022)

Aerodynamic performance of a fan-in-wing configuration in hover and forward flight is further investigated using an active flow control technique. The previous investigation has demonstrated the efficacy of active flow control to improve the aerodynamic performance of fan-in-wing device operating at a fixed rotational frequency. In the present study, the fan-in-wing device is numerically investigated at a fixed fan pitch angle operating at a series of rotational frequencies under two free stream conditions, one representing the device in hover (zero free stream velocity) and another representing the device in forward flight condition (non-zero free stream velocity). Effects of different active flow control strategies are assessed and compared with the baseline model in both hover and forward flight conditions.