gebhart/patrepeval huggingface dataset:
Polymeric Nanoparticles Active against Dual-Species Bacterial Biofilms (2021)

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>. This study highlights a potential clinical application of the presented polymeric platform.
Scale-based diffusive image filtering preserving boundary sharpness and fine structures (2001)

Image acquisition techniques often suffer from low signal-to-noise ratio (SNR) and/or contrast-to-noise ratio (CNR). Although many acquisition techniques are available to minimize these, post acquisition filtering is a major off-line image processing technique commonly used to improve the SNR and CNR. A major drawback of filtering is that it often diffuses/blurs important structures along with noise. In this paper, we introduce two scale-based filtering methods that use local structure size or "object scale" information to arrest smoothing around fine structures and across even low-gradient boundaries. The first of these methods uses a weighted average over a scale-dependent neighborhood while the other employs scale-dependent diffusion conductance to perform filtering. Both methods adaptively modify the degree of filtering at any image location depending on local object scale. Object scale allows us to accurately use a restricted homogeneity parameter for filtering in regions with fine details and in the vicinity of boundaries while a generous parameter in the interiors of homogeneous regions. Qualitative experiments based on both phantoms and patient magnetic resonance images show significant improvements using the scale-based methods over the extant anisotropic diffusive filtering method in preserving fine details and sharpness of object boundaries. Quantitative analyses utilizing 25 phantom images generated under a range of conditions of blurring, noise, and background variation confirm the superiority of the new scale-based approaches.
Fast Pump-Power-Independent Brillouin Fiber Optic sensor (2014)

A fast and distributed Brillouin sensor, which is immune to pump power variations is presented. 120Hz strain vibrations are measured over 50m fiber with >1kHz sampling rate, demonstrating immunity to >5dB pump power variations.
Piezoelectric transducer for electrical string instruments and pickup means comprising the same (1981)

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Steric Effects on the Synthesis, Structure, Reactivity and Selectivity of t-Phosphine Rhodium Complex Hydroformylation Catalysts (1987)

Abstract Bulky trivalent phosphorus ligands of transition metal complexes were often observed to affect catalyst activity and selectivity. In the area of the low pressure hydroformylation of α-olefins in the presence of rhodium complexes, Pruett and Smith observed early (1) that the use of bulky ortho-substituted phosphite ester ligands leads to a decrease of the ratio of straight chain versus branched aldehyde products (n/i ratio). More recently van Leeuwen and Roobek have shown (2) that rhodium complexes of such bulky ligands are much more active catalysts than the much studied triphenylphosphine-rhodium catalyst system, in the hydroformylation of linear internal and branched terminal olefins. They suggested that for steric reasons only two bulky ligands could be coordinated to the same rhodium in such complexes and that such ligands could increase the coordinative unsaturation of rhodium, thus leading to a higher reactivity. Indeed a number of coordinatively unsaturated rhodium carbonyl complexes of bulky trialkylphosphine ligands were described by Otsuka and coworkers (3) and by Freeman and Young (4).
Retinoic Acid Repression of Cell-Specific Helix-Loop-Helix-Octamer Activation of the Calcitonin/Calcitonin Gene-Related Peptide Enhancer (1993)

We have investigated the mechanism underlying repression of calcitonin/calcitonin gene-related peptide (CT/CGRP) gene expression by retinoic acid. Retinoic acid treatment of the CA77 thyroid C-cell line decreased CT/CGRP promoter activity two- to threefold, which correlates well with the decrease in calcitonin and CGRP mRNA levels. Repression is mediated through the nuclear retinoic acid receptors (RAR) on the basis of the retinoid specificity, the sensitivity of repression (half-maximal repression at 0.2 nM), and the additional repression caused by cotransfection of an alpha-RAR expression vector. The sequences required for retinoic acid repression were localized to an 18-bp element containing cell-specific enhancer activity. The enhancer binds helix-loop-helix (HLH) and octamer transcription factors that act synergistically to activate transcription. Retinoic acid repression requires both these factors since mutations in either motif resulted in the loss of repression. Furthermore, repression was observed only in cell lines containing enhancer activity. We have used electrophoretic mobility shift assays to show that repression does not involve direct DNA binding of RAR or RAR-retinoid X receptor heterodimers. Instead, repression appears to involve interactions with the stimulatory enhancer factors. Following retinoic acid treatment, there was a specific decrease in an enhancer complex containing both HLH and octamer proteins. Formation of the HLH-octamer complex was also specifically blocked by the addition of exogenous RAR-retinoid X receptor protein. These results demonstrate that RAR can repress CT/CGRP gene transcription by interfering with combinatorial activation by cell-specific HLH and octamer proteins.
Multi-modal system for locating heads and faces (2002)

We designed a modular system using a combination of shape analysis, color segmentation and motion information for locating reliably heads and faces of different sizes and orientations in complex images. The first of the system's three channels does a shape analysis on gray-level images to determine the location of individual facial features as well as the outlines of heads. In the second channel the color space is analyzed with a clustering algorithm to find areas of skin colors. The color space is first calibrated, using the results from the other channels. In the third channel motion information is extracted from frame differences. Head outlines are determined by analyzing the shapes of areas with large motion vectors. All three channels produce lists of shapes, each marking an area of the image where a facial feature or a part of the outline of a head may be present. Combinations of such shapes are evaluated with n-gram searches to produce a list of likely head positions and the locations of facial features. We tested the system for tracking faces of people sitting in front of terminals and video phones and used it to track people entering through a doorway.
Aperiodic grating structure for TE (1995)

Design issues related to implementation of the scattering optimization method for aperiodic gratings are discussed. Critical design parameters are highlighted and it is shown how their selection affects the final grating structure. The aperiodic grating design technique is then implemented to develop a grating for TE<SUB>11</SUB> to TE<SUB>11</SUB> mode conversion in a circular waveguide at 20 GHz. The length of the grating is 19cm and it has a conversion efficiency of 98.34%.
Dye laser pumped atomic iodine laser (1978)

Lasing has been demonstrated on the 2P1/2–2P3/2 transition in atomic iodine by optically pumping I2 vapor to dissociation with a flashlamp-pumped tunable dye laser. Lasing at 1.315 μ has been observed for pump wavelengths from 5010 to 4930 Å. The device holds promise as a rapidly pulsed gain diagnostic for existing or future iodine systems.
Integration of MEMS Inertial and Pressure Sensors for Vertical Trajectory Determination (2014)

Integration of a low-cost global positioning system (GPS) with a microelectromechanical system-based inertial measurement unit (MEMS-IMU) is a widely used method that takes advantage of the individual superiority of each system to get a more accurate and robust navigation performance. However, because of poor observations as well as multipath effects, the GPS has low accuracy in the vertical direction. As a result, the navigation accuracy even in an integrated GPS/MEMS-IMU system is more challenged in the vertical direction than the horizontal direction. To overcome this problem, this paper investigates the integration of a MEMS barometric pressure sensor with the MEMS-IMU for vertical position/velocity tracking without the GPS that has applications in sports. A cascaded two-step Kalman filter consisting of separate orientation and position/velocity subsystems is proposed for this integration. Slow human movements in addition to more rapid sport activities such as vertical and step-down jumps can be tracked using the proposed algorithm. The height-tracking performance is benchmarked against a reference camera-based motion-tracking system and an error analysis is performed. The experimental results show that the vertical trajectory tracking error is less than 28.1 cm. For the determination of jump vertical height/drop, the proposed algorithm has an error of less than 5.8 cm.
MetILs<sup>3</sup>: A Strategy for High Density Energy Storage Using Redox‐Active Ionic Liquids (2017)

A systematic approach is presented for increasing the concentration of redox‐active species in electrolytes for nonaqueous redox flow batteries (RFBs). Starting with an ionic liquid consisting of a metal coordination cation (MetIL), ferrocene‐containing ligands and iodide anions are substituted incrementally into the structure. While chemical structures can be drawn for molecules with 10 m redox‐active electrons (RAE), practical limitations such as melting point and phase stability constrain the structures to 4.2 m RAE, a 2.3× improvement over the original MetIL. Dubbed “MetILs 3 ,” these ionic liquids possess redox activity in the cation core, ligands, and anions. Throughout all compositions, infrared spectroscopy shows the ethanolamine‐based ligands primarily coordinate to the Fe 2+ core via hydroxyl groups. Calorimetry conveys a profound change in thermophysical properties, not only in melting temperature but also in suppression of a cold crystallization only observed in the original MetIL. Square wave voltammetry reveals redox processes characteristic of each molecular location. Testing a laboratory‐scale RFB demonstrates Coulombic efficiencies >95% and increased voltage efficiencies due to more facile redox kinetics, effectively increasing capacity 4×. Application of this strategy to other chemistries, optimizing melting point and conductivity, can yield >10 m RAE, making nonaqueous RFB a viable technology for grid scale storage.
Solid-Phase Synthesis of 2,4,6-Trisubstituted Pyridines (1998)

A new solid-phase synthesis of 2,4,6-trisubstituted pyridines from hydroxyacetophenones is described. The synthesis includes Claisen−Schmidt and Michael reactions on Wang resin to produce 1,5-diketones, which are then cyclized with ammonium acetate. The pyridine substituents are introduced independently and are derived from readily available, diverse sets of starting materials. The method is suitable for the synthesis of arrays of compounds.
Resonant-phonon terahertz quantum-cascade laser operating at 2.1 THz (λ≃141 µm) (2004)

The development of quantum-cascade lasers (QCLs) at 2.1 THz (λ≃141 µm), which is the longest wavelength QCL to date without the assistance of magnetic fields, is reported. This laser uses a structure based on resonant-phonon depopulation, and a metal–metal waveguide to obtain high modal confinement with low waveguide losses. Lasing was observed up to a heatsink temperature of 72 K in pulsed mode and 40 K in continuous-wave (CW) mode, and 1.2 mW of power was obtained in CW mode at 17 K.
Low-complexity hierarchical lapped transform for lossy-to-lossless image coding in JPEG XR / HD Photo (2008)

JPEG XR is a draft international standard undergoing standardization within the JPEG committee, based on a Microsoft technology known as HD Photo. One of the key innovations in the draft JPEG XR standard is its integer-reversible hierarchical lapped transform. The transform can provide both bit-exact lossless and lossy compression in the same signal flow path. The transform requires only a small memory footprint while providing the compression benefits of a larger block transform. The hierarchical nature of the transform naturally provides three levels of multi-resolution signal representation. Its small dynamic range expansion, use of only integer arithmetic and its amenability to parallelized implementation lead to reduced computational complexity. This paper provides an overview of the key ideas behind the transform design in JPEG XR, and describes how the transform is constructed from simple building blocks.
Food safety and quality applications of line-scan Raman imaging and spectroscopy techniques (Conference Presentation) (2019)

Commercial Raman systems generally conduct imaging and spectroscopy measurements at subcentimeter scales. Such small spatial ranges cannot be used to inspect food samples with large surface areas (e.g., tomato fruit and beef steak), which is not convenient for food experiments. A line-scan macro-scale Raman system has been developed using a 785 nm line laser to implement high-throughput Raman chemical imaging (RCI) for food safety and quality research. A one-axis positioning table is used to move the samples to accumulate hyperspectral data using a pushbroom method. A dispersive Raman spectrograph is used in the system, which can be configured to backscattering RCI mode for surface inspection and spatially offset Raman spectroscopy (SORS) mode for subsurface inspection. In-house developed LabVIEW software is used to fulfill functions for system control, hardware parameterization, and data transfer. The systems is flexible and versatile for food test, and it has been used to evaluate safety and quality of various food and agricultural products, such as detecting chemical adulterants mixed in food powders, mapping carotenoid content on carrot cross section, imaging whole surface of pork shoulder, and authenticating foods and ingredients through packages.
Mobius filters and resonators (2002)

Resonator and filter topologies are introduced which rely on the geometric deformation of a guiding structure resulting in the establishment of resonant conditions in more compact structures. Conceptually, the structures are analogous to Mobius strips. The path length of the edge in a Mobius strip is twice an length of the edge of the rectangle deformed in creating the Mobius strip geometry. Analogously, this means the structure can be at resonance even though the length of the line, before deformation, was a half wavelength long. The concept has been demonstrated in planar geometries and in wire-loaded cavity structures. The dual-mode nature of the fundamental resonance is readily apparent.
Contact-Mediated Inhibition Between Oligodendrocyte Progenitor Cells and Motor Exit Point Glia Establishes the Spinal Cord Transition Zone (2014)

Rapid conduction of action potentials along motor axons requires that oligodendrocytes and Schwann cells myelinate distinct central and peripheral nervous system (CNS and PNS) domains along the same axon. Despite the importance of this arrangement for nervous system function, the mechanisms that establish and maintain this precise glial segregation at the motor exit point (MEP) transition zone are unknown. Using in vivo time-lapse imaging in zebrafish, we observed that prior to myelination, oligodendrocyte progenitor cells (OPCs) extend processes into the periphery via the MEP and immediately upon contact with spinal motor root glia retract back into the spinal cord. Characterization of the peripheral cell responsible for repelling OPC processes revealed that it was a novel, CNS-derived population of glia we propose calling MEP glia. Ablation of MEP glia resulted in the absence of myelinating glia along spinal motor root axons and an immediate breach of the MEP by OPCs. Taken together, our results identify a novel population of CNS-derived peripheral glia located at the MEP that selectively restrict the migration of OPCs into the periphery via contact-mediated inhibition.
Synthesis of Oligonucleotides Covalently Linked to Intercalating Agents and to Reactive Groups (1991)

Abstract The use of modified supports involving 2,2′-dithiodiethanol allows solid-phase synthesis of oligonucleotides derivatized at their 3′ end with an acridine or a phenanthroline derivative or with phosphate, thiophosphate and amino group.
Constitutive over‐expression of AtGSK1 induces NaCl stress responses in the absence of NaCl stress and results in enhanced NaCl tolerance in <i>Arabidopsis</i> (2001)

GSK3/shaggy-like protein kinases have been shown to play diverse roles in development and signal transduction pathways in various organisms. An Arabidopsis homologue of GSK3/shaggy-like kinase, AtGSK1, has been shown to be involved in NaCl stress responses. In order to further clarify the role of AtGSK1 in NaCl stress responses in plants, we generated transgenic Arabidopsis plants that over-expressed AtGSK1 mRNA. These plants showed enhanced resistance to NaCl stress when assayed either as whole plants or by measurement of root growth on NaCl plates. In addition, AtGSK1 transgenic plants in the absence of NaCl stress showed phenotypic changes, such as accumulation of anthocyanin, that were similar to those observed in wild-type plants under NaCl stress. Transgenic plants accumulated 30-50% more Na+ than did wild-type plants when subjected to NaCl stress, and Ca2+ content was increased by 15-30% in the transgenic plants regardless of the NaCl stress level. Northern blotting revealed that AtGSK1 over-expression induced expression of the NaCl stress-responsive genes AtCP1, RD29A and CHS1 in the absence of NaCl stress. In addition, AtCBL1 and AtCP1 were super-induced in the NaCl-stressed transgenic plants. Taken together, these results suggest that AtGSK1 is involved in the signal transduction pathway(s) of NaCl stress responses in Arabidopsis.
Anti-adhesive surfaces through hyaluronan coatings. (1997)

The ability to resist adhesion of proteins, bacteria, cells and tissue is an important requirement for the surfaces of medical devices. This article describes a surface-modification process that imparts anti-adhesive properties to the surfaces of biomedical materials through the covalent binding of hyaluronan. It can be applied to a wide range of materials to yield anti-adhesive surfaces on plastics, metals and ceramics.
Optimal cut of langasite for high performance SAW devices (1999)

The results of a theoretical and experimental investigation of the SAW propagation characteristics in an optimal region of langasite defined by the Euler angles (-15°-+10°,120°-165°,20°-45°) are presented. Based on temperature coefficients of the elastic constants derived from experimental data, some optimal orientations of langasite characterized by high electromechanical coupling factor (K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), zero power flow angle (PFA) and low or zero temperature coefficient of frequency (TCF) are found. It is shown that the SAW velocity in the region of interest is highly anisotropic, and this results in a significant amount of diffraction which must be taken into account in the search for orientations useful for SAW devices. An orientation having simultaneously zero PFA, zero TCF, negligible diffraction, and relatively high piezoelectric coupling has been found and verified experimentally. The experimental results are in excellent agreement with the calculated SAW characteristics. The frequency response of a SAW device fabricated on the optimal cut of langasite is presented and demonstrates that high performance SAW filters can be realized on this optimal cut of langasite.
Layered Titanium Disilicide Stabilized by Oxide Coating for Highly Reversible Lithium Insertion and Extraction (2012)

The discovery of new materials has played an important role in battery technology development. Among the newly discovered materials, those with layered structures are often of particular interest because many have been found to permit highly repeatable ionic insertion and extraction. Examples include graphite and LiCoO(2) as anode and cathode materials, respectively. Here we report C49 titanium disilicide (TiSi(2)) as a new layered anode material, within which lithium ions can react with the Si-only layers. This result is enabled by the strategy of coating a thin (<5 nm) layer of oxide on the surface of TiSi(2). This coating helped us rule out the possibility that the measured capacity is due to surface reactions. It also stabilizes TiSi(2) to allow for the direct observation of TiSi(2) in its lithiated and delithiated states. In addition, this stabilization significantly improved the charge and discharge performance of TiSi(2). The confirmation that the lithium-ion storage capacity of TiSi(2) is a result of its layered structure is expected to have major fundamental and practical implications.
Identification and biochemical characterization of novel putative substrates for the epidermal growth factor receptor kinase. (1992)

To gain insight into the mechanisms which control the mitogenic response to epidermal growth factor (EGF), we have partially purified and characterized several intracellular proteins which are phosphorylated on tyrosine residues following activation of the epidermal growth factor receptor (EGFR). Partial purification was achieved by immunoaffinity chromatography using immobilized anti-phosphotyrosine antibodies. Antisera generated against the partially purified proteins were used to identify at least five novel EGFR putative substrates, designated, on the basis of their apparent molecular weight, p97, p68, p61, p56, and p23. All of these proteins became specifically phosphorylated on tyrosine after EGF treatment of intact cells, as assessed by phosphoamino acid analysis, and none of them represented an EGFR degradation product. The phosphorylation of these proteins appeared to be relatively specific for the EGFR. In particular, an EGFR-related kinase, erbB-2 was much less efficient than EGFR at phosphorylating p97, p56, and p23 and incapable of phosphorylating p68. The identification of these novel EGFR putative substrates should lead to a better understanding of the mechanisms controlling the specificity of EGFR-mediated mitogenic signaling.