gebhart/patrepeval huggingface dataset:
Tissue harmonics cancellation using time-reversal (2008)

Pulse-inversion sequences are sensitive to the nonlinear echoes from microbubbles allowing an improvement in the blood-to-tissue contrast. However, at larger mechanical indexes, this contrast is reduced by harmonics produced during nonlinear propagation. A method for tissue harmonics cancellation exploiting time-reversal is experimentally implemented using a 128-channel 12-bit emitter-receiver. The probe calibration is performed by acquiring the nonlinear echo of a wire in water. These distorted pulses are time-reversed, optimized and used for the pulse-inversion imaging of a tissue phantom. Compared to normal (straight) pulses, the time-reversed distorted pulses reduced the tissue signal in pulse-inversion by 11 dB. The second harmonics signal from microbubbles flowing in a wall-less vessel was unaffected by the correction. This technique can thus increase the blood-to-tissue contrast ratio while keeping the pressure and the number of pulses constant.
Nanoimaging and medically functional biointerfaces (2013)

Focusing on the nanobiomedical imaging, medically functional biointerfaces and translational medicine, we have developed a functional cluster of imaging, nano-characterization, nano-fabrication and micromanipulation facilities, including two combined imaging systems based on the atomic force microscopy (AFM) and the environmental scanning electron microscopy (ESEM), which provides a perfect platform for real-space studies on living micro/nanoscale biointerfaces at high resolution. Methodological breakthroughs in the imaging of living biointerfaces have been made as a result. Using the above techniques, our research concentrates on medically functional biointerfaces, i.e. special functional biointerfaces which are closely related to human health, disease and medical activities. The concept of “micro/nanoscaled topography-coupled-mechanics mechanisms (TCMM)” has been introduced into the study of medically functional biointerfaces, focusing specially on interfaces in blood vessels, bone and cancer tissues. Inspired by the functional biointerface among blood/vessel/blood-flowing and its related theory extracted from Chinese medicine, we put forward a novel borderline discipline—“biomechanopharmacology” to underline the relationship between biomechanics and pharmacology in the biomedicine field. In view of the drawbacks of biomedicine approaches to date, we advocate for translational medicine, and emphasize the two-way relationship between the “bench” and the “bedside” in the field of medically functional biointerfaces at the micro/ nanoscale. As a result, the artificial-adhesion controllable interfaces, such as bioinspired micro/nanoscale interfaces for better blood compatibility or aptamer-mediated efficient capture and release of T lymphocytes were developed. Moreover, we also translated microscale mechanical parameters for use as “biomarkers” in clinical tests. To sum up, our researches are expected to open a new way to better understand the treatment of major diseases, such as cardiovascular diseases and cancer.
Detection of the carpal bone contours from 3-D MR images of the wrist using a planar radial scale-space snake (1998)

In this paper we consider the problems encountered when applying snake models to detect the contours of the carpal bones in 3-D MR images of the wrist. In order to improve the performance of the original snake model introduced by Kass [1], we propose a new image force based on one-dimensional (1-D) second-order Gaussian filtering and contrast equalization. The improved snake is less sensitive to model initialization and has no tendency to cut off contour sections of high curvature, because 1-D radial scale-space relaxation is used. Contour orientation is used to minimize the influence of neighboring image structures. Due to 1-D contrast equalization an intensity insensitive measure of external energy is obtained. As a consequence a good balance between internal and external energetic contributions of the snake is established, which also improves convergence. By incorporating this new image force into the snake model, we succeed in accurate contour detection, even when relatively high noise levels are present and when the contrast varies along the contours of the bones.
Note: Improved heater design for high-temperature hollow cathodes (2017)

We present an improved heater design for thermionic cathodes using a rhenium filament encased in a boron nitride ceramic sleeve. This heater is relatively simple to fabricate, yet has been successfully used to reliably and repeatably light a lanthanum hexaboride (LaB6) hollow cathode based on a previously published design without noticeable filament degradation over hundreds of hours of operation. The high decomposition temperature of boron nitride (2800 C for inert environments) and melting point for rhenium (3180 C) make this heater especially attractive for use with LaB6, which may require operating temperatures upwards of 1700 C. While boron nitride decomposes in air above 1000 C, the heater was used only at vacuum with an inert gas discharge, and no degradation was observed. Limitations of current state of the art cathode heaters are also discussed and compared with the rhenium-boron nitride combination.
Treatment of Chronic Hepatitis B in Asia-Pacific Countries: Is the Asia-Pacific Consensus Statement being followed? (2010)

These data suggest that clinicians from the Asia-Pacific region use criteria beyond those advocated in treatment guidelines when deciding whether to initiate treatment in HBV-infected patients.
Photorefractive Properties and Applications of Barium Titanate and Tungsten Bronze Ferroelectrics (2006)

This thesis is an experimental and theoretical investigation of the photorefractive properties of barium titanate and tungsten bronze ferroelectrics, and applications thereof. In the first part, the physics of the photorefractive effect is presented. The band transport equations are solved for three cases that describe the photorefractive mechanism in a crystal with one photorefractive species and either one or two types of charge carriers, or in a crystal with two photorefractive species, but only one type of charge carrier. In the second part, the coupled wave theory of two-wave mixing in photorefractive crystals is reviewed. Effects of energy coupling between the two interacting beams are discussed along with experimental methods for determining the two-beam coupling coefficient and the photorefractive response time. The photorefractive crystals barium titanate, strontium barium niobate, and barium strontium potassium sodium niobate are described in the third part. A summary of their optical, physical and electrical properties is presented for use in subsequent sections of the thesis. In the fourth part, the photorefractive properties of these crystals are presented. Data from two-beam coupling experiments are used to obtain the two-beam coupling coefficients and the photorefractive response times of the crystals under a variety of experimental conditions. The band transport models are then applied to these results. Figures of merit are defined in the fifth part that are then used in a comparison of several photorefractive materials, including the barium titanate, the strontium barium niobate, and the barium strontium potassium sodium niobate crystals. Both ferroelectric and non-ferroelectric materials are considered. In the last part, applications using barium titanate and the tungsten bronze ferroelectrics are described. By using the self-focusing properties of barium titanate and strontium barium niobate, the compensation of nonlinear optical distortions with phase conjugation is demonstrated. A passive phase conjugator that relies on no external mirrors and uses strontium barium niobate as the nonlinear medium is also described. Finally, a thresholding passive phase conjugate mirror is then presented along with several devices that can perform mathematical operations on images such as subtraction and differentiation.
Design, Fabrication, and Testing of an Auxiliary Cooling System for Jet Engines (2001)

This report summarizes the technical effort of the Active Cooling for Enhanced Performance (ACEP) program sponsored by NASA. It covers the design, fabrication, and integrated systems testing of a jet engine auxiliary cooling system, or turbocooler, that significantly extends the use of conventional jet fuel as a heat sink. The turbocooler is designed to provide subcooled cooling air to the engine exhaust nozzle system or engine hot section. The turbocooler consists of three primary components: (1) a high-temperature air cycle machine driven by engine compressor discharge air, (2) a fuel/ air heat exchanger that transfers energy from the hot air to the fuel and uses a coating to mitigate fuel deposits, and (3) a high-temperature fuel injection system. The details of the turbocooler component designs and results of the integrated systems testing are documented. Industry Version-Data and information deemed subject to Limited Rights restrictions are omitted from this document.
Effects of monophasic and biphasic shocks on action potentials during ventricular fibrillation in dogs. (1993)

This study determined the response of action potentials during ventricular fibrillation (VF) to timed monophasic and biphasic shocks. A floating glass microelectrode was used to record intracellularly from the anterior right ventricle in 10 open-chest dogs. After 10 seconds of electrically induced VF, 5-millisecond monophasic and 2.5/2.5-millisecond biphasic shocks or 16-millisecond monophasic and 8/8-millisecond biphasic shocks were given via mesh electrodes on either side of the microelectrode. Monophasic and biphasic truncated exponential shocks of 5 V/cm were given with coupling intervals timed from the beginning of a VF action potential to the shock ranging from 50 to 70 milliseconds in 5-millisecond increments. Each coupling interval for each waveform was tested during a different VF episode. The interval between successive activations during VF was 86 +/- 15 milliseconds (mean +/- SD). The refractory period during VF was 61 +/- 5 milliseconds for 5-millisecond monophasic shocks and 66 +/- 6 milliseconds for 2.5/2.5-millisecond biphasic shocks (P < .05). At each coupling interval, action potential duration at 50% repolarization (APD50) was significantly prolonged by the shocks compared with the mean preshock APD50 (P < .05). ADP50 duration increased significantly with increases in the coupling interval (P < .05) for both monophasic and biphasic waveforms. For all coupling intervals together, APD50 prolongation as a percent of the mean preshock APD50 was 170 +/- 55%, 192 +/- 45%, 151 +/- 44%, and 175 +/- 45% for 5- and 16-millisecond monophasic and 2.5/2.5- and 8/8-millisecond biphasic waveforms, respectively. This APD50 prolongation was greater for monophasic than biphasic shocks and was greater for longer than shorter waveforms (P < .05). Thus, during VF, (1) the refractory period for 5-V/cm truncated exponential waveforms lasting 5 milliseconds is approximately 75% of the VF activation interval; (2) the refractory period is shorter for monophasic than for comparable biphasic waveforms; (3) both monophasic and biphasic 5-V/cm shock fields cause prolongation of action potential duration; (4) prolongation of action potential duration increases as the coupling interval increases; and (5) prolongation of action potential duration is greater for monophasic shocks and for longer shock waveforms.
Faculty Opinions recommendation of Interleukin 10 acts on regulatory T cells to maintain expression of the transcription factor Foxp3 and suppressive function in mice with colitis. (2010)

Read the full review for this Faculty Opinions recommended article: Interleukin 10 acts on regulatory T cells to maintain expression of the transcription factor Foxp3 and suppressive function in mice with colitis.
THE ACTION MECHANISM OF RELAXATION EFFECT OF ATROPINE ON THE ISOLATED RABBIT CORPUS CAVERNOSUM (1999)

Atropine has both a contraction effect at lower concentrations and a relaxation effect at higher concentrations on cavernosal smooth muscle. It is presumed that the relaxation at higher concentrations is mediated via increasing intracellular calcium sequestration, not by hyperpolarization or secretion of EDRF.
A novel low-loss y-type splitter with adjustable branching ratio (2007)

Low loss splitters based on two mode waveguides are evaluated using near-field scanning optical microscopy and computer simulations. The branching ratio is a temperature sensitive function of the relative mode phases at the splitter.
Single‐particle approach for analyzing flow systems. Part II: Regional residence times and local flow rates (1983)

Abstract The analysis of Part I (Rubinovitch and Mann, 1983) is continued here, considering the movements of a single particle in an arbitrary flow system in terms of the total times it resides in various flow regions. Results from the theory of Markov chains are used to derive expressions for the joint distribution of number of visits and total residence time in a flow region and for the total regional residence time distribution. Further, the relationships between the local particle flow rate, number of visits to a flow region, and net flow rate through the system are derived. Specifically, it is shown that equation image This relation is valid for any general flow system and any general region in the system. It holds true irrespective of the number of inlets and outlets to the region or of the nature of the internal mixing in the region. It is further shown how this relation leads to an experimental method for measuring local flow rates.
Twin-Resolution Phase Shifters Based Massive MIMO Hybrid Precoding for LEO SATCOM with Nonlinear PAs (2021)

Massive multiple-input multiple-output (MIMO) technology has attracted much attention in low earth orbit (LEO) downlink satellite communication (SATCOM) systems recently since the energy efficiency (EE) and spectral efficiency can be significantly improved. In order to reduce the power consumption for the massive MIMO LEO SATCOM systems, we focus on the hybrid analog/digital architecture in this work. Considering the limited resolution of the phase shifters in practical MIMO SATCOM systems, a twin-resolution phase shifting (TRPS) network is proposed to make a meticulous tradeoff between the power consumption and array gains. In addition, we examine the impact of the distortion, introduced by the power amplifiers (PAs) to the system design, by considering nonlinear PA models. Moreover, we propose an efficient algorithm for TRPS-based hybrid precoding with nonlinear PAs. Numerical results show the EE gains considering nonlinear distortion and the performance superiority of the proposed hybrid architecture compared with the baselines.
Surface Alignment, Anchoring Transitions, Optical Properties and Topological Defects in Nematic Bent-Core Materials C7 and C12 (2011)

We address the status of oxadiazole mesogens, C7 and C12, reported to show the biaxial nematic phase, by exploring material aspects (chemical stability, surface anchoring, optical and dielectric properties, topological defects) linked to the type of nematic order. We demonstrate that the isogyres splitting in conoscopic patterns of homeotropic state depends on sample thickness and is associated with variations of molecular tilt along the normal to substrates. We observe isolated topological point defects (boojums and hedgehogs), as well as nonsingular “escaped” disclinations pertinent only to the uniaxial nematic order. Our conclusion is that C7 and C12 feature only a uniaxial nematic phase and the apparent biaxiality is caused by surface effects.
Comparison of standardized bariums with varying rheological parameters on swallowing kinematics in males (2012)

This study measured dose-response of a range of commercially available liquid barium materials designed for use in videofluoroscopic oropharyngeal swallowing assessments, particularly as they relate to the necessity of adding a thickening agent for swallow safety. A group of 25 adult males representing various medical diagnoses consented to participate, with 16 qualifying to complete a videofluoroscopic swallowing assessment with liquid barium materials of three viscosities (nectar: 300 cP, thin honey: 1,500 cP, thick honey: 3,000 cP). Outcome measures included airway invasion (Penetration-Aspiration score), postswallow residue, and patient preference. Penetration-Aspiration and residue scores did not significantly differ between thin honey and thick honey bariums. Significantly more severe airway invasion was observed with nectar boluses than with two levels of honey boluses (p < 0.001). Significantly more residue was observed in the oral cavity (p < 0.002) and valleculae (p < 0.001) with thin and thick honey bariums than with nectar barium. Thin honey was rated as "easy" or "average" to drink by 67% of subjects, compared with 54% for thick honey. This study supports the use of thin honey barium over thick honey barium during videofluoroscopic swallowing assessments because the two honey bariums were comparable in terms of airway protection and postswallow residue in the oropharynx and the thin honey was preferred by patients.
Synthetic Ligands that Disrupt Bacterial Quorum Sensing Pathways and Outcomes (2008)

We are developing chemical tools that attenuate cell‐cell communication pathways in bacteria. Bacteria communicate using small organic molecules and peptides to monitor their population densities in a process called “quorum sensing.” At high cell densities, bacteria use this signaling network to switch from an isolated, nomadic existence to that of a multicellular community. This lifestyle switch is significant; only in groups will pathogenic bacteria turn on virulence pathways and grow into drug‐impervious communities called biofilms that are the basis of myriad chronic infections. In turn, certain symbiotic bacteria will only colonize their hosts and initiate beneficial behaviors at high population densities. The molecular mechanisms of these processes are only now being delineated. Our research is focused broadly on the design of non‐native ligands that can intercept quorum sensing and provide new insights into its role in host/microbe interactions. We have developed a series of efficient synthetic methods that provide us with straightforward access to these ligands. This talk will introduce our research approach and highlight recent results.
A Genetically Encoded Photocaged Tyrosine (2006)

Proteinaktivierung mit Licht: Ein photoaktivierbarer Tyrosinrest wurde in E. coli als Antwort auf das Amber-Codon, TAG, genetisch codiert. Nach Substitution am Tyr 503 im aktiven Zentrum der β-Galactosidase kann das Enzym in vitro oder direkt im Bakterium mit 360-nm-Licht photoaktiviert werden. Die Methode könnte zur Photoregulierung biologischer Prozesse wie Transkription, Signaltransduktion und Zell-Trafficking führen. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2006/z600264_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Block copolymers near the microphase separation transition. 4. Dielectric spectroscopy (1989)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBlock copolymers near the microphase separation transition. 4. Dielectric spectroscopyX. Quan, G. E. Johnson, E. W. Anderson, and F. S. BatesCite this: Macromolecules 1989, 22, 5, 2451–2456Publication Date (Print):May 1, 1989Publication History Published online1 May 2002Published inissue 1 May 1989https://pubs.acs.org/doi/10.1021/ma00195a076https://doi.org/10.1021/ma00195a076research-articleACS PublicationsRequest reuse permissionsArticle Views194Altmetric-Citations38LEARN 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-Alertsclose Get e-Alerts
Multiflavor streptavidin (2023)

Compounds and methods are described for producing streptavidin mutants with changed affinities. In particular, modifications to the sequence of the natural streptavidin gene is described to create amino acid substitutions resulting in greater affinity for biotin substitutes than for biotin.
Budget-Aware Video Crowdsourcing at the Cloud-Enhanced Mobile Edge (2021)

With convenient Internet access and ubiquitous high-quality sensors in end-user devices, a growing number of content consumers are engaging in the content creation process. Meanwhile, mobile edge computing (MEC) can provision distributed computing resources for local data processing. The MEC-enhanced video crowdsourcing application will gather user-generated video contents and collectively distribute them to the viewers of interest. To empower the crowdsourced video streaming at the edge, we investigate how to efficiently transmit data from content generators to the viewers. In particular, for a group of collaborative mobile users willing to share their data with the viewers, the content generation and delivery scheme is designed by considering the cost incurred by the crowdsourcing application. By leveraging the cloud resources available at the wireless base stations, the uploading or downloading server site is chosen for each user. To minimize the system makespan, i.e., the overall data transmission time among the generators and viewers, the user association scheme is also designed to efficiently utilize the diverse wireless radio resources. As compared with traditional centralized/distributed content delivery schemes, the proposed algorithm can improve the cost-effectiveness of distributed radio/cloud resources deployed at the mobile edge.