gebhart/patrepeval huggingface dataset:
Dynamic light scattering studies of resorcinol formaldehyde gels as precursors of organic aerogels (1991)

Aerogels are exceptionally light foams formed by extraction of the solvent from a gel under supercritical conditions where surface tension forces are greatly reduced. This results in very little shrinkage of the gels when dried. The dried aerogels have extremely high surface area and have applications as catalyst supports and thermal and acoustic insulators. While most studies have used aerogels formed from silicon dioxide, the authors focused on organic aerogels obtained by the reaction of resorcinol and formaldehyde (RF). The kinetics of the gel formation have been studied using dynamic light scattering. These studies encompass three areas:(1) initial reaction of RF into branched 'clusters' as a function of resorcinol/catalyst (Na2CO3) ratio; (2) aggregation of the clusters into linear chains to form the gel network; and (3) the modulus of the completely gelled sample. The initial particle size increases linearly with R/C ratio as was observed by TEM on dried samples. The scattering intensity increases exponentially as the gel is formed as is observed for polymer gels formed by spinodal decomposition. The cooperative diffusion coefficient (which is directly related to the gel modulus) scales with concentration to a power of approximately unity, which is larger than the 3/4 usually observed for polymer networks.
Retraction of “Synthesis of Phosphorodiamidate Morpholino Oligonucleotides and Their Chimeras Using Phosphoramidite Chemistry” (2019)

ADVERTISEMENT RETURN TO ISSUEPREVRetractionNEXTORIGINAL ARTICLEThis notice is a retraction.Retraction of "Synthesis of Phosphorodiamidate Morpholino Oligonucleotides and Their Chimeras Using Phosphoramidite Chemistry"Sibasish PaulSibasish PaulMore by Sibasish Paul and Marvin H. Caruthers*Marvin H. CaruthersMore by Marvin H. CaruthersCite this: J. Am. Chem. Soc. 2019, 141, 23, 9430Publication Date (Web):May 30, 2019Publication History Published online30 May 2019Published inissue 12 June 2019https://pubs.acs.org/doi/10.1021/jacs.7b04308https://doi.org/10.1021/jacs.7b04308retractionACS PublicationsCopyright © 2019 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views11366Altmetric-Citations-LEARN 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 PDF (172 KB) Get e-Alertsclose Get e-Alerts
Optics-on-a-chip for ultrafast manipulation of 350-MHz hard x-ray pulses (2021)

Microelectromechanical systems (MEMS) are miniature devices integrated into a vast range of industrial and consumer applications. Optical MEMS are developed for dynamic spatiotemporal control in lightwave manipulation and communication as modulators, switches, multiplexers, spectrometer, etc. However, they have not been shown to function similarly in sub-nm wavelength regimes, namely, with hard x-rays, as high-brilliance pulsed x-rays have proven powerful for addressing challenges in time-domain science, from energy conversion to neurobiological control. While desirable temporal properties of x-ray pulses can be enhanced by optics, conventional x-ray optics are inherently massive in size, hence, never dynamic. We demonstrate highly ultrafast x-ray optics-on-a-chip based on MEMS capable of modulating hard x-ray pulses exceeding 350 MHz, 10<sup>3</sup>× higher than any other mechanical modulator, with a pulse purity >10<sup>6</sup> without compromising the spectral brilliance. Moreover, the timing characteristics of the devices can be tuned on-the-fly to deliver optimal pulse properties to create a host of dynamic x-ray instruments and applications, impossible with traditional optics of 10<sup>9</sup>× bulkier and more massive. The advent of the ultrafast optics-on-a-chip heralds a new paradigm of x-ray photonics, time-domain science, and accelerator diagnostics, especially at not only the future-generation light sources that offer coherent and high-frequency pulses but also lab-based facilities that normally do not offer timing structures.
Optical Domain Wideband RF Spectrum Analysis Using Parametric Mixing (2011)

We present the design of an optical domain staring RF spectrum analyzer based on parametric multicasting and spectral slicing with a periodic filter. An implementation covering an 18GHz band with 250MHz resolution bandwidth is presented.
GaN-based micro chemical sensor nodes for early warning chemical agents (2007)

We are developing micro chemical sensor nodes that can be used for real time, remote detection and early warning of chemical agent threats. The chemical sensors in our sensor nodes utilize GaN HEMTs (High Electron Mobility Transistors) fabricated with catalytically active transition metal gate electrodes. The GaN HEMT chemical sensors exhibit high sensitivity and selectivity toward chemical agent simulants such as DECNP (Diethyl cyano phosphonate), and this is the first time that chemical agent simulants have been detected with GaN micro sensors. Response time of the GaN HEMT sensor to a chemical species is within a second, and the maximum electronic response speed of the sensor is ~3 GHz. A prototype micro chemical sensor node has been constructed with the GaN sensor, a micro controller, and an RF link. The RF sensor node is operated with a single 3V Li battery, dissipating 15 mW during the RF transmission with 5 dBm output power. The microcontroller allows the operation of the RF sensor nodes with a duty cycle down to 1 %, extending lifetime of the RF sensor nodes over 47 days. Designed to transmit RF signals only at the exposures to chemical agents and produce collective responses to a chemical agent via a sensorweb, the GaN micro chemical sensor nodes seem to be promising for chemical agent beacons.
Accurate image reconstruction using DOI information and its implications for the development of compact PET systems (2000)

The authors study the use of a computationally efficient sinogram restoration (SR) approach for reconstruction of 2D PET data acquired by systems with depth-of-interaction capability. When the effects of scatter and randoms are ignored, the authors' preliminary results show that the proposed approach can yield images of excellent resolution uniformity for a hypothetical compact system with a field-of-view (FOV) as large as 98% of the detector-ring size. In comparison with images generated by the conventional rebinning approach, the resolution uniformity across the FOV in the image produced by incorporating SR is improved by a factor of about 10, and the spatial resolution at the edge of the FOV is improved by a factor of about 2.2. Moreover, the SR approach produces better intensity recovery and source positioning. Integration of the use of DOI detectors and SR reconstruction may thus provide a new way for developing compact PET systems. For a given FOV, such a compact system can produce images of quality better than those obtained by a conventional system that employs a detector ring approximately 50% larger than the compact system. The much reduced detector-ring size of the compact system can greatly reduce production cost, improve image resolution and resolution uniformity, and increase system sensitivity.
Organic Electroluminescence Displays (1997)

Recently, organic light emitting diodes have received a lot of attention in different research laboratories world-wide. Red, green and blue emitting devices are readily available. Devices with luminous efficiencies greater than 15 lm/W and lifetimes longer than 10,000 hours have been demonstrated. In this article, we will discuss the basic devices used in physics, materials used in organic light emitting diodes, device degradation mechanisms, and the opportunities of using this technology for commercial display applications.
High-resolution photomask transmission and phase measurement tool (2002)

Acintic measurements of optical transmission are critical for determining the quality of repairs on advanced ArF- generation photomasks. We describe a new 193 nm tool designed to provide mask makers and uses the capability to resolve and measure photomask features with dimensions less than 0.20 micron. Measurements of transmission with sub-1 percent error are achieved in 30 seconds by using a laser probe beam imaged onto the top of the mask surface. We present high-resolution actinic images of embedded attenuator phase shift masks and of binary masks and discuss various methods and results of measuring mask transmission. A scheme to add phase retardation measurement capability to the tool is described, and preliminary results are discussed.
Macro fiber composite-based energy harvester for human knee (2019)

The harvesting of energy from human motion for portable and wearable electronic devices has received considerable attention. This letter describes a lightweight macrofiber composite (MFC)-based energy harvester for capturing biomechanical energy through the natural motion of the human knee. In the proposed device, a slider-crank mechanism is used to transform the rotary motion of the knee joint to linear motion, and a bending beam is used to transform the linear motion to a bending motion. When walking, a bending deformation is induced in two MFC slices attached to the bending beam, generating electrical energy. To test the performance of the developed device, treadmill tests at various walking speeds and resistive loads are performed. Experimental results show that the lightweight harvester (weighing just 307 g) can generate 1.60 mW without increasing the human effort required for walking. This is expected to significantly promote the usage of biomechanical energy harvesters.
Potent New Small-Molecule Inhibitor of Botulinum Neurotoxin Serotype A Endopeptidase Developed by Synthesis-Based Computer-Aided Molecular Design (2009)

Botulinum neurotoxin serotype A (BoNTA) causes a life-threatening neuroparalytic disease known as botulism. Current treatment for post exposure of BoNTA uses antibodies that are effective in neutralizing the extracellular toxin to prevent further intoxication but generally cannot rescue already intoxicated neurons. Effective small-molecule inhibitors of BoNTA endopeptidase (BoNTAe) are desirable because such inhibitors potentially can neutralize the intracellular BoNTA and offer complementary treatment for botulism. Previously we reported a serotype-selective, small-molecule BoNTAe inhibitor with a K(i) (app) value of 3.8+/-0.8 microM. This inhibitor was developed by lead identification using virtual screening followed by computer-aided optimization of a lead with an IC(50) value of 100 microM. However, it was difficult to further improve the lead from micromolar to even high nanomolar potency due to the unusually large enzyme-substrate interface of BoNTAe. The enzyme-substrate interface area of 4,840 A(2) for BoNTAe is about four times larger than the typical protein-protein interface area of 750-1,500 A(2). Inhibitors must carry several functional groups to block the unusually large interface of BoNTAe, and syntheses of such inhibitors are therefore time-consuming and expensive. Herein we report the development of a serotype-selective, small-molecule, and competitive inhibitor of BoNTAe with a K(i) value of 760+/-170 nM using synthesis-based computer-aided molecular design (SBCAMD). This new approach accounts the practicality and efficiency of inhibitor synthesis in addition to binding affinity and selectivity. We also report a three-dimensional model of BoNTAe in complex with the new inhibitor and the dynamics of the complex predicted by multiple molecular dynamics simulations, and discuss further structural optimization to achieve better in vivo efficacy in neutralizing BoNTA than those of our early micromolar leads. This work provides new insight into structural modification of known small-molecule BoNTAe inhibitors. It also demonstrates that SBCAMD is capable of improving potency of an inhibitor lead by nearly one order of magnitude, even for BoNTAe as one of the most challenging protein targets. The results are insightful for developing effective small-molecule inhibitors of protein targets with large active sites.
Fatigue and Stress Monitoring with Magnetic Sensor Arrays (2006)

Background and selected applications of conformable eddy current sensor networks for monitoring fatigue damage in complex geometry regions of specimens, components and structures are presented. Also, capability to use the same sensors to monitor stress in ferromagnetic materials is described. These eddy current sensors, called MWM ® -Arrays, use model-based multivariate inversion methods to provide reliable early detection and monitoring of fatigue cracks and real-time monitoring of stress through paint or coatings. Proven capabilities are illustrated by results for aluminum alloy, titanium alloy, and high-strength steel fatigue specimens, with MWM-Arrays mounted inside holes and on other cylindrical surfaces. Linear and circular MWM configurations (MWM-Rosettes) also provide the capability to detect and monitor fatigue cracks in embedded (between layers) sensor formats and with sensors placed under bolt heads as “smart washers.” This paper describes implementations of this capability for aircraft focused applications, including past and ongoing coupon, subcomponent, component and full-scale aircraft fatigue tests as well as for structural health monitoring.
No Fuss Distance Metric Learning using Proxies (2017)

We address the problem of distance metric learning (DML), defined as learning a distance consistent with a notion of semantic similarity. Traditionally, for this problem supervision is expressed in the form of sets of points that follow an ordinal relationship -- an anchor point $x$ is similar to a set of positive points $Y$, and dissimilar to a set of negative points $Z$, and a loss defined over these distances is minimized. While the specifics of the optimization differ, in this work we collectively call this type of supervision Triplets and all methods that follow this pattern Triplet-Based methods. These methods are challenging to optimize. A main issue is the need for finding informative triplets, which is usually achieved by a variety of tricks such as increasing the batch size, hard or semi-hard triplet mining, etc. Even with these tricks, the convergence rate of such methods is slow. In this paper we propose to optimize the triplet loss on a different space of triplets, consisting of an anchor data point and similar and dissimilar proxy points which are learned as well. These proxies approximate the original data points, so that a triplet loss over the proxies is a tight upper bound of the original loss. This proxy-based loss is empirically better behaved. As a result, the proxy-loss improves on state-of-art results for three standard zero-shot learning datasets, by up to 15% points, while converging three times as fast as other triplet-based losses.
Purification of trehalose synthase from baker's yeast (1993)

A trehalose synthase purified from baker's yeast contained 56-kDa, 102-kDa and 123-kDa polypeptides as its main components. The 102-kDa polypeptide was isolated and shown to be a specific trehalose-6-phosphatase. The trehalose-6-phosphate synthase (Tre6P synthase) activator described by Londesborough and Vuorio [(1991) J. Gen. Microbiol. 137, 323-330] was shown to be phosphoglucoisomerase and to function entirely by generating fructose 6-phosphate. Below 35 degrees C, fructose 6-phosphate is a powerful activator of the Tre6P synthase activity of intact trehalose synthase, especially at physiological phosphate concentration, but does not affect its trehalose-6-phosphatase activity nor the Tre6P synthase activity of truncated trehalose synthase containing truncated versions of the 123-kDa polypeptide. At 50 degrees C, activation by fructose 6-phosphate and inhibition by phosphate are greatly decreased, resulting in an unusually high temperature-dependence for the Tre6P synthase activity at a physiological phosphate concentration (2 mM).
Recent multiscale AM-FM methods in emerging applications in medical imaging (2012)

Amplitude-modulation frequency-modulation (AM-FM) decompositions represent images using spatially-varying sinusoidal waves and their spatially-varying amplitudes. AM-FM decompositions use different scales and bandpass filters to extract the wide range of instantaneous frequencies and instantaneous amplitude components that may be present in an image. In the past few years, as the understanding of its theory advanced, AM-FM decompositions have been applied in a series of medical imaging problems ranging from ultrasound to retinal image analysis, yielding excellent results. This article summarizes the theory of AM-FM decompositions and related medical imaging applications.
A new haemostatic device utilising a novel transmission structure for delivery of adrenaline and microwave energy at 5.8 GHz (2016)

The design, development and testing of a microwave and adrenaline haemostat for use in endoscopic procedures is shown herein. A novel transmission line structure has been developed to facilitate the delivery of both adrenaline and microwave energy to achieve haemostasis. A proximal end impedance transformer and radiative tip have been designed and manufactured to provide good match between the novel hollow transmission line and the microwave source and tissue respectively. Microwave energy at 5.8GHz has been successfully delivered into porcine liver model providing a controlled and focused coagulation zone of approximately 5mm which would be useful for plugging of bleeding vessels.
Abstract 18971: Changes in HDL Quality Rather Than Macrophage Function Mediate the Atheroprotective Phenotype in Usf1 Knockout Mice (2013)

We previously demonstrated that allelic variants of Usf1 are associated with myriad metabolic phenotypes in human populations and the knockout of Usf1 in mice leads to a favorable metabolic phenotype. Here, we have studied the role of macrophages and HDL particles in the development of atherosclerosis in the Usf1 -/- mice. A mouse strain of double knockout of Usf1 and Ldlr (Usf1 -/- Ldlr -/-) was generated, and mice along with their Usf1 +/+ Ldlr -/- littermates were fed with a high fat diet diet for 20 weeks. The double knockouts displayed a three-fold reduction in their atherosclerotic lesion area as demonstrated by the aortic longitudinal section based en face technique. To study the potential mechanisms behind the attenuated lesion development in the Usf1 -/- mice, we knocked down USF1 by constitutive expression of shRNA from human monocyte cell line (THP1). We differentiated monocytes into macrophages and loaded them with acetylated LDL for 48 hours. We observed no change in cholesterol efflux from USF1 knockdown macrophages to wild type mouse serum or HDL when compared to efflux from control cells expressing non-targeting shRNA. Furthermore, we performed bone marrow transplantation of Usf1 -/- and wild type bone marrow to Ldlr -/- mouse background. After 12 weeks of western diet we saw no change in atherosclerotic lesion development in the aortic root area in the mice with Usf1 -/- bone marrow compared to the mice with wild type bone marrow, indicating a macrophage independent mechanism for the atheroprotection in Usf1 -/- mice. The Usf1 -/- mice displayed both elevated cholesterol (p<0.001) and phospholipids (p<0.001) in their serum both on western and regular chow diet. Interestingly, cholesterol efflux from wild type THP1 macrophages to Usf1 -/- serum and HDL was significantly increased (p<0.05 and p<0.001, respectively) compared to serum and HDL from the wild type mice indicating that not only increased serum HDL concentration but also changes in HDL particle quality in the Usf1 -/- mice have properties increasing cholesterol efflux. Our study establishes the atheroprotective role for Usf1 deficiency that could be in part due to the favorable changes HDL particle quality rather than macrophage specific effects in the Usf1 -/- mice.
Attention-Based Hierarchical Deep Reinforcement Learning for Lane Change Behaviors in Autonomous Driving (2019)

Performing safe and efficient lane changes is a crucial feature for creating fully autonomous vehicles. Recent advances have demonstrated successful lane following behavior using deep reinforcement learning, yet the interactions with other vehicles on road for lane changes are rarely considered. In this paper, we design a hierarchical Deep Reinforcement Learning (DRL) algorithm to learn lane change behaviors in dense traffic. By breaking down overall behavior to sub-policies, faster and safer lane change actions can be learned. We also apply temporal and spatial attention to the DRL architecture, which helps the vehicle focus more on surrounding vehicles and leads to smoother lane change behavior. We conduct our experiments in the TORCS simulator and the results outperform the state-of-art deep reinforcement learning algorithm in various lane change scenarios.
<i>In vitro</i> inhibition and intracellular enhancement of lysosomal α‐galactosidase A activity in Fabry lymphoblasts by 1‐deoxygalactonojirimycin and its derivatives (2000)

Fabry disease is a lysosomal storage disorder caused by deficient lysosomal alpha-galactosidase A (alpha-Gal A) activity. Deficiency of the enzyme activity results in progressive deposition of neutral glycosphingolipids with terminal alpha-galactosyl residue in vascular endothelial cells. We recently proposed a chemical chaperone therapy for this disease by administration of 1-deoxygalactonojirimycin, a potent inhibitor of the enzyme, at subinhibitory intracellular concentrations [Fan, J.-Q., Ishii, S., Asano, N. and Suzuki, Y. (1999) Nat. Med. 5, 112-115]. 1-Deoxygalactonojirimycin served as a specific chaperone for those mutant enzymes that failed to maintain their proper conformation to avoid excessive degradation. In order to establish a correlation between in vitro inhibitory activity and intracellular enhancement activity of the specific chemical chaperone, a series of 1-deoxygalactonojirimycin derivatives were tested for activity with both alpha-Gal A and Fabry lymphoblasts. 1-Deoxygalactonojirimycin was the most potent inhibitor of alpha-Gal A with an IC50 value of 0.04 microM. alpha-Galacto-homonojirimycin, alpha-allo-homonojirimycin and beta-1-C-butyl-deoxygalactonojirimycin were effective inhibitors with IC50 values of 0.21, 4.3 and 16 microM, respectively. N-Alkylation, deoxygenation at C-2 and epimerization at C-3 of 1-deoxygalactonojirimycin markedly lowered or abolished its inhibition toward alpha-Gal A. Inclusion of 1-deoxygalactonojirimycin, alpha-galacto-homonojirimycin, alpha-allo-homonojirimycin and beta-1-C-butyl-deoxygalactonojirimycin at 100 microM in culture medium of Fabry lymphoblasts increased the intracellular alpha-Gal A activity by 14-fold, 5.2-fold, 2.4-fold and 2.3-fold, respectively. Weaker inhibitors showed only a minimum enhancement effect. These results suggest that more potent inhibitors act as more effective specific chemical chaperones for the mutant enzyme, and the potent competitive inhibitors of alpha-Gal A are effective specific chemical chaperones for Fabry disease.