gebhart/patrepeval huggingface dataset:
Nanocrystalline porous silicon ultrasonic transmitter with patterned emission area (2007)

We propose a nanocrystalline porous silicon (nc-PS) ultrasonic transmitter with a variable directional pattern. The directional pattern is realized by using an interference effect. An ultrasonic wave is emitted from electrodes on the nc-PS layer according to the applied electrical current. The emission areas of the transmitter were patterned in order to use the interference between the emitted ultrasonic waves. To observe the interference effect, our device was designed to have two emission areas. The directional pattern induced by the interference effect depends on the distance between the emission areas, and the frequency and the phase difference of the currents applied to the emission areas. We confirmed that the sharpness and the lobe number of the directional pattern can be changed by the phase difference between two emission areas. We also confirmed that the direction of the main lobe can be changed by the phase difference. With the characteristics of the designable and controllable directional pattern, the proposed device is suitable for distance sensors, especially for proximity sensors.
Altération par les sels des pierres de construction: Influence des propriétés capillaires et des conditions d'évaporation (2006)

9 pages, compte rendu de conférence
Contribution of the Active Site Histidine Residues of Ribonuclease A to Nucleic Acid Binding (2001)

His12 and His119 are critical for catalysis of RNA cleavage by ribonuclease A (RNase A). Substitution of either residue with an alanine decreases the value of k(cat)/K(M) by more than 10(4)-fold. His12 and His119 are proximal to the scissile phosphoryl group of an RNA substrate in enzyme-substrate complexes. Here, the role of these active site histidines in RNA binding was investigated by monitoring the effect of mutagenesis and pH on the stability of enzyme-nucleic acid complexes. X-ray diffraction analysis of the H12A and H119A variants at a resolution of 1.7 and 1.8 A, respectively, shows that the amino acid substitutions do not perturb the overall structure of the variants. Isothermal titration calorimetric studies on the complexation of wild-type RNase A and the variants with 3'-UMP at pH 6.0 show that His12 and His119 contribute 1.4 and 1.1 kcal/mol to complex stability, respectively. Determination of the stability of the complex of wild-type RNase A and 6-carboxyfluorescein approximately d(AUAA) at varying pHs by fluorescence anisotropy shows that the stability increases by 2.4 kcal/mol as the pH decreases from 8.0 to 4.0. At pH 4.0, replacing His12 with an alanine residue decreases the stability of the complex with 6-carboxyfluorescein approximately d(AUAA) by 2.3 kcal/mol. Together, these structural and thermodynamic data provide the first thorough analysis of the contribution of histidine residues to nucleic acid binding.
Temporally resolved cavity ring-down spectroscopy in a pulsed nitrogen plasma (2002)

Cavity ring-down spectroscopy (CRDS) has enabled temporally resolved measurements of the N2+ ion concentration in a pulsed atmospheric pressure nitrogen plasma. A 10 ns voltage pulse is applied to a dc-sustained plasma to change the ionization fraction rapidly. Our measurements show that the pulse increases the N2+ ion concentration from 3.9×1012 to more than 1.5×1013 cm−3, and that the N2+ concentration returns to the dc level in about 10 μs. We also determine the electron density by measuring the electrical conductivity of the plasma. Because N2+ is the dominant ion, the good agreement between electrical and CRDS measurements provides validation of the temporally resolved CRDS technique.
A YAC-based contig of 1.5 Mb spanning the human multidrug resistance gene region and delineating the amplification unit in three human multidrug-resistant cell lines. (1995)

A contig of 21 nonchimeric yeast artificial chromosomes (YACs) has been assembled across 1.5 Mb of the multidrug resistance (MDR) gene region located at 7q21, and formatted with four previously reported probes, six newly isolated probes, and three sequence-tagged sites (STSs) from internal and end fragments of YACs. A physical map of rare cutter restriction enzyme sites across the region was also constructed by pulsed-field gel electrophoretic (PFGE) analysis of four overlapping YAC clones. The amplification unit of this region in different cell lines was then determined by Southern blot analysis on the basis of the physical map and probes. Amplified DNA was located in extrachromosomal elements in human MDR cell lines studied here, and the size of the amplification unit was determined to be discrete in one MDR amplification but variable in others.
Accelerating Spiking Neural Networks using Memristive Crossbar Arrays (2020)

Biologically-inspired spiking neural networks (SNNs) hold great promise to perform demanding tasks in an energy and area-efficient manner. Memristive devices organized in a crossbar array can be used to accelerate operations of artificial neural networks (ANNs) while circumventing limitations of traditional computing paradigms. Recent advances have led to the development of neuromorphic accelerators that employ phase-change memory (PCM) devices. We propose an approach to fully unravel the potential of such systems for SNNs by integrating entire layers, including synaptic weights as well as neuronal states, into crossbar arrays. However, the key challenges of such realizations originate from the intrinsic imperfections of the PCM devices that limit their effective precision. Thus, we investigated the impact of these limitations on the performance of SNNs and demonstrate that the synaptic weight and neuronal state realization using 4-bit precision provides a robust network performance. Moreover, we evaluated the scheme for a multi-layer SNN realized using an experimentally verified model of the PCM devices and achieved performance that is comparable to a floating-point 32-bit model.
Variables Affecting the Fracture Toughness of Dental Composites (1987)

The fracture toughness of a variety of dental composites was evaluated using notched bending specimens, with and without pre-cracks. The pre-crack simulates more accurately a sharp, natural flaw in a material than does a notch, and is standard procedure in fracture-toughness evaluation. The fracture toughness was related to the filler composition and degree of conversion in the composite resins. In general, fracture toughness was highest in the more heavily filled resins, independent of degree of conversion in the matrix. The results also show that producing a pre-crack in certain composites reduced the value of their fracture toughness compared with notched-only specimens.
Improved diode properties in zinc telluride thin film-silicon nanowire heterojunctions (2015)

In this study, structural and optoelectronic properties and photodedection characteristics of diodes constructed from p-zinc telluride (ZnTe) thin film/n-silicon (Si) nanowire heterojunctions are reported. Dense arrays of vertically aligned Si nanowires were successfully synthesized on (1 1 0)-oriented n-type single crystalline Si wafer using simple and inexpensive metal-assisted etching (MAE) process. Following the nanowire synthesis, p-type ZnTe thin films were deposited onto vertically oriented Si nanowires via radio frequency magnetron sputtering to form three-dimensional heterojunctions. A comparative study of the structural results obtained from X-ray diffraction and Raman spectroscopy measurements showed the improved crystallinity of the ZnTe thin films deposited onto the Si nanowire arrays. The fabricated nanowire-based heterojunction devices exhibited remarkable diode characteristics and enhanced optoelectronic properties and photosensitivity in comparison to the planar reference. The electrical measurements revealed that the diodes with nanowires had a well-defined rectifying behaviour with a rectification ratio of 104 at ±2 V and a relatively small ideality factor of n = 1.8 with lower reverse leakage current and series resistance at room temperature in dark condition. Moreover, an open-circuit voltage of 100 mV was also observed under illumination. Based on spectral photoresponsivity measurements, the nanowire-based device exhibited a distinct responsivity and high detectivity in visible and near-infrared (NIR) wavelength regions. The device characteristics observed here offer that the fabricated ZnTe thin film/Si nanowire-based p–n heterojunction structures will find important applications in future and will be a promising candidate for high-performance and low-cost optoelectronic device applications, NIR photodedectors in particular.
High-Index-Contrast λ  = 1.55 μm AlInGaAs/InP Laser Heterostructure Waveguides Through Selective Core Oxidation (2018)

A deep-etched high-index-contrast ridge waveguide for low bend loss photonic integration is realized through selective lateral oxidation of a λ = 1.55 µm AlInGaAs multi-quantum well diode laser heterostructure waveguide core layer sandwiched between InP cladding layers. The process is enabled by first depositing a thin protective layer to fully suppress the thermal dissociation of exposed InP surfaces during the subsequent oxygen-enhanced wet thermal oxidation process. Either ≈30–100 nm of InGaAs grow through selective epitaxial regrowth via MOCVD or ≈6 Å of HfO2 grows via atomic layer deposition is found to be effective at preventing dissociation damage. A lateral oxidation depth of ≈1.0 µm is achieved with a 3 h oxidation at 525 °C, yielding a buried oxide high optical confinement waveguide with reduced capacitance and contact resistance, suitable for the integration of high-speed, low-bend loss integrated laser devices.
Amphiphilic Phosphorus Dendrons Associated with Anti-inflammatory siRNA Reduce Symptoms in Murine Collagen-Induced Arthritis (2023)

Small interfering RNA (siRNA) holds promise for treating rheumatoid arthritis by inhibiting major cytokines such as tumor necrosis factor-α (TNF-α). We developed original cationic amphiphilic phosphorus dendrons to produce dendriplexes associated with TNF-α siRNA. The dendrons were made of 10 pyrrolidinium end groups and a C17 aliphatic chain. The dendriplexes demonstrated the ability to protect siRNA from nuclease degradation and to promote macrophage uptake. Moreover, they led to potent inhibition of TNF-α expression in the lipopolysaccharide-activated mouse macrophage cell line RAW264.7 in vitro model. A significant anti-inflammatory effect in the murine collagen-induced arthritis model was observed through arthritis scoring and histological observations. These results open up essential perspectives in using this original amphiphilic dendron to reduce the disease burden and improve outcomes in chronic inflammatory diseases.
Ultrafast all-optical switching in a continuous layer gap plasmon metasurface (Conference Presentation) (2018)

All-optical nanophotonic switches, not bound by the inherent RC delays of electronic circuits, have the potential to push data-processing speeds beyond the limits of Moore’s Law. This has lead to the investigation of light-matter interactions in nanostructured materials in several all-optical data processing applications. To have a true impact on the field of ultrafast data-transfer, it is important to demonstrate switching in the telecom frequency range. We have designed a continuous layer gap plasmon metasurface, comprising a layer of gold nanodisk resonators on a 20 nm film of ZnO deposited on an optically thick gold layer. The performance of the metasurface has been investigated through numerical studies, using the optical properties of as-grown gold and zinc oxide, characterized by ellipsometry. An on-off ratio of 10.6 dB has been observed in simulations. Experimental studies are underway. The findings of this research work will pave the pathway to the design of ultra-compact and ultrafast optical switches employing ultrafast, dynamically tunable metasurfaces.
The scale of a texture and its application to segmentation (2008)

This paper examines the issue of scale in modeling texture for the purpose of segmentation. We propose a scale descriptor for texture and an energy minimization model to find the scale of a given texture at each location. For each pixel, we use the intensity distribution in a local patch around that pixel to determine the smallest size of the domain that can be used to generate neighboring patches. The energy functional we propose to minimize is comprised of three terms: The first is the dissimilarity measure using the Wasserstein distance or Kullback-Leibler divergence between neighboring patch distributions; the second maximizes the entropy of the local patch, and the third penalizes larger size at equal fidelity. Our experiments show the proposed scale model successfully captures the intrinsic scale of texture at each location. We also apply our scale descriptor for improving texture segmentation based on histogram matching [15].
A case study of long-term CCA preservative leaching from treated hardwood poles in a humid tropical condition (2016)

Chromated copper arsenate (CCA)-treated Malaysian hardwoods have long been used as&#13;\nutility poles, posts, construction piles and motorway fencing in soil contact exposed to the&#13;\nthreats of decay fungi and termites. Despite global concerns citing predominantly temperate&#13;\nconditions of long-term leaching of CCA toxic heavy metals from wood into surrounding&#13;\nsoils and groundwater since the 1990’s, the preservative leaching severity in the tropics has&#13;\nbeen far less appreciated due to dearth of work in this area. In 2013 (after 30 years exposure),&#13;\nlevels of total copper, chromium and arsenic within 20 treated hardwood poles of Sarawak&#13;\nand in soils surrounding these poles, installed in 1980 and 1981 at a plot located in Timber&#13;\nResearch and Technical Training Centre, Kuching, Sarawak, Malaysia, were sampled. The&#13;\nground is waterlogged after heavy rainfall. It is shown that there is insignificant variations of&#13;\nCCA salt retention in wood between 1300 cm above ground and 0-20 cm below ground&#13;\n(P&lt;0.05). Nevertheless levels of these elements are significantly (P&lt;0.05) elevated in soils&#13;\nsurrounding, especially up to 25 mm away from, the poles than at distant sampling points&#13;\n(150 – 300 mm) from poles as well as at sites well away from the poles containing very low&#13;\nlevels (&lt;6 – 13.4 ppm) of such heavy metals. Metal levels were also highest at the soil surface&#13;\ndirectly in contact with the poles (0 – 50 mm soil depth position) and decreased with&#13;\nremaining 2 soil depth positions 150 – 200 mm and 300 – 350 mm. Mean extractable arsenic&#13;\nlevels ranged from 14.5 to 100.1 ppm, chromium levels from 23.3 to 148.3 ppm and copper&#13;\nfrom 21.8 to 104.7 ppm. Results, rather than indicating relatively higher CCA leaching,&#13;\nconcurred with that reported temperate experience and showed that soil closest to the treated&#13;\npoles are most contaminated, albeit slightly, after 30 years of in-ground exposure.
Adequacy of Power-to-volume Scaling Philosophy to Simulate Natural Circulation in Integral Test Facilities. (1998)

Theoretical and experimental investigations were carried out to study the adequacy of power-to-volume scaling philosophy for the simulation of natural circulation and to establish the scaling philosophy applicable for the design of the Integral Test Facility (ITF-AHWR) for the Indian Advanced Heavy Water Reactor (AHWR). The results indicate that a reduction in the flow channel diameter of the scaled facility as required by the power-to-volume scaling philosophy may affect the simulation of natural circulation behaviour of the prototype plants. This is caused by the distortions due to the inability to simulate the frictional resistance of the scaled facility. Hence, it is recommended that the flow channel diameter of the scaled facility should be as close as possible to the prototype. This was verified by comparing the natural circulation behaviour of a prototype 220MWe Indian PHWR and its scaled facility (FISBE-1) designed based on power-to-volume scaling philosophy. It is suggested from examinations using a mathematical model and a computer code that the FISBE-1 simulates the steady state and the general trend of transient natural circulation behaviour of the prototype reactor adequately. Finally the proposed scaling method was applied for the design of the ITF-AHWR.
Myogenic cellular transplantation and regeneration: sorting through progenitor heterogeneity. (2004)

Growth and regeneration of skeletal muscle fibers in response to injury are made possible by the presence of resident myogenic progenitor cells. Researchers have attempted to isolate and transplant these cells to regenerate new muscle in cases involving injury, disease, or genetic deficiencies. Reports from such experiments underscore the functional diversity of progenitors obtained from skeletal muscle; however, currently there is no reliable means by which to positively identify and isolate the most desirable muscle progenitor populations. Taking a cue from the hematopoietic community, researchers in this area have begun to investigate cell surface protein expression in progenitor populations. Previous findings in cultured myogenic cells and our results in cells obtained directly from dissociated muscle suspensions indicate that cells sorted based on their expression of the commonly-studied myogenic cell surface proteins Sca-1 and CD34 exhibit differing regenerative abilities. However, results obtained to date are insufficient to clearly delineate whether the expression of either of these proteins is an exclusive characteristic of efficient myogenic progenitors. Nonetheless, observations from these studies clearly suggest that progenitor heterogeneity should be an important consideration during the development and implementation of muscle regeneration strategies. Additional research is necessary to establish reliable selection criteria for the isolation of efficient progenitors, which will facilitate therapeutic discoveries and enhance our understanding of factors affecting regeneration outcomes.
The presenilins as potential drug targets in Alzheimer’s disease (1999)

Alzheimer’s disease (AD) is a major neurodegenerative disorder affecting a large proportion of the elderly. Given the increasing life expectancy in developed countries, the generation of new drugs to treat AD represents one of the major challenges for the pharmaceutical industry in the coming decades. Central to the disease is the abnormal processing of amyloid precursor protein (APP) resulting in the release of the β-amyloid peptide (Aβ), the major constituent of plaques in the brains of AD patients. Mis-sense mutations causing AD have been found in the APP gene, and more recently in the presenilin genes. Remarkably, all mutations investigated cause an increased production of a particular form of the Aβ that is more prone to precipitation. Presenilins, which are multi-membrane spanning proteins, appear to specifically regulate the production of Aβ by controlling the intramembranous proteolytic cleavage of APP. Inhibition of presenilin is therefore an obvious drug target, although side-effects caused by interference with the processing of other proteins, including notch, have to be considered.
Strategic Approaches to Overcome Resistance against Gram-Negative Pathogens Using β-Lactamase Inhibitors and β-Lactam Enhancers: Activity of Three Novel Diazabicyclooctanes WCK 5153, Zidebactam (WCK 5107), and WCK 4234 (2018)

Limited treatment options exist to combat infections caused by multidrug-resistant (MDR) Gram-negative bacteria possessing broad-spectrum β-lactamases. The design of novel β-lactamase inhibitors is of paramount importance. Here, three novel diazabicyclooctanes (DBOs), WCK 5153, zidebactam (WCK 5107), and WCK 4234 (compounds 1-3, respectively), were synthesized and biochemically characterized against clinically important bacteria. Compound 3 inhibited class A, C, and D β-lactamases with unprecedented k<sub>2</sub>/ K values against OXA carbapenemases. Compounds 1 and 2 acylated class A and C β-lactamses rapidly but not the tested OXAs. Compounds 1-3 formed highly stable acyl-complexes as demonstrated by mass spectrometry. Crystallography revealed that 1-3 complexed with KPC-2 adopted a "chair conformation" with the sulfate occupying the carboxylate binding region. The cefepime-2 and meropenem-3 combinations were effective in murine peritonitis and neutropenic lung infection models caused by MDR Acinetobacter baumannii. Compounds 1-3 are novel β-lactamase inhibitors that demonstate potent cross-class inhibition, and clinical studies targeting MDR infections are warranted.
A Taxonomy of GPGPU Performance Scaling (2015)

Graphics processing units (GPUs) range from small, embedded designs to large, high-powered discrete cards. While the performance of graphics workloads is generally understood, there has been little study of the performance of GPGPU applications across a variety of hardware configurations. This work presents performance scaling data gathered for 267 GPGPU kernels from 97 programs run on 891 hardware configurations of a modern GPU. We study the performance of these kernels across a 5× change in core frequency, 8.3× change in memory bandwidth, and 11× difference in compute units. We illustrate that many kernels scale in intuitive ways, such as those that scale directly with added computational capabilities or memory bandwidth. We also find a number of kernels that scale in non-obvious ways, such as losing performance when more processing units are added or plateauing as frequency and bandwidth are increased. In addition, we show that a number of current benchmark suites do not scale to modern GPU sizes, implying that either new benchmarks or new inputs are warranted.
Elliptically polarized terahertz emission in the forward direction of a femtosecond laser filament in air (2008)

Elliptically polarized terahertz emission from a femtosecond laser filament in air in the forward direction was discovered by using a wire grid polarizer and electro-optic sampling technique. The generation mechanism could be through four-wave optical rectification or second-order optical rectification inside the filament zone where the inversion symmetry of air is broken.
Association Mapping and the Genomic Consequences of Selection in Sunflower (2013)

The combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L.) association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. We used these data to characterize overall patterns of genomic diversity and to perform association analyses on plant architecture (i.e., branching) and flowering time, successfully identifying numerous associations underlying these agronomically and evolutionarily important traits. Overall, we found variable levels of linkage disequilibrium (LD) across the genome. In general, islands of elevated LD correspond to genomic regions underlying traits that are known to have been targeted by selection during the evolution of cultivated sunflower. In many cases, these regions also showed significantly elevated levels of differentiation between the two major sunflower breeding groups, consistent with the occurrence of divergence due to strong selection. One of these regions, which harbors a major branching locus, spans a surprisingly long genetic interval (ca. 25 cM), indicating the occurrence of an extended selective sweep in an otherwise recombinogenic interval.
Top-gate ZnO nanowire transistors with ultrathin organic gate dielectric (2009)

To take full advantage of the small size and excellent charge transport properties of inorganic nanowires, we have prepared FETs and integrated circuits based on individual single-crystalline ZnO nanowires with patterned, metallic top gate electrodes and a thin, solution-processed gate dielectric.