gebhart/patrepeval huggingface dataset:
Observation of 4H–SiC to 3C–SiC polytypic transformation during oxidation (2001)

We have observed the formation of single and multiple stacking faults that sometimes give rise to 3C–SiC bands in a highly doped n-type 4H–SiC epilayer following dry thermal oxidation. Transmission electron microscopy following oxidation revealed single stacking faults and bands of 3C–SiC in a 4H–SiC matrix within the 4H–SiC epilayer. These bands, parallel to the (0001) basal plane, were not detected in unoxidized control samples. In addition to the 3.22 eV peak of 4H–SiC, Cathodoluminescence spectroscopy at 300 K after oxidation revealed a spectral peak at 2.5 eV photon energy that was not present in the sample prior to oxidation. The polytypic transformation is tentatively attributed to the motion of Shockley partial dislocations on parallel (0001) slip planes. The generation and motion of these partials may have been induced by stresses caused either by the heavy doping of the epilayer or nucleation from defect.
Hydrogen Uptake of Platinum-Doped Graphite Nanofibers and Stochastic Analysis of Hydrogen Spillover (2007)

Graphite nanofibers (GNFs) were doped with platinum in an attempt to activate the materials for moderate temperature hydrogen adsorption. Characterization of the 1% Pt/GNF sample indicates well-dispersed, metallic platinum particles ranging from 2 to 5 nm in diameter. At 27 °C and 20 bar, the hydrogen uptake of 1% Pt/GNF was less than 0.1 wt % and showed no increase relative to the GNF precursor within experimental detection limits. To explore this apparent anomaly, a stochastic Monte Carlo simulation was used to analyze the hydrogen spillover process for idealized two-dimensional surfaces with two surface types with interfacial mass transfer from the first to the second surface site. The model suggests interfacial mass transfer may not improve overall surface coverage when the rates of adsorption and desorption to the support are comparable. Dimensionless groupings are introduced to the stochastic simulation to explore the conditions in which interfacial transfer will lead to significant surface coverage from a catalytically active surface to a previously inert surface. The implications for hydrogen storage are discussed.
Tears – More to Them Than Meets the Eye: Why Tears Are A Good Source of Biomarkers in Parkinson'S Disease (2020)

Tears are a known source of biomarkers for both ocular and systemic diseases with particular advantages; specifically, the noninvasiveness of sample collection and a unique and increasingly better-defined protein composition. Here, we discuss our rationale for use of tears for discovery of biomarkers for Parkinson's disease (PD). These reasons include literature supporting changes in tear flow and composition in PD, and the interconnections between the ocular surface system and neurons affected in PD. We highlight recent data on the identification of tear biomarkers including oligomeric α-synuclein, associated with neuronal degeneration in PD, in tears of PD patients and discuss possible sources for its release into tears. Challenges and next steps for advancing such biomarkers to clinical usage are highlighted.
Digital Calibration of a Continuous-Time Cascaded ΣΔ Modulator based on Variance Derivative Estimation (2006)

This paper presents a digital calibration system for a continuous-time cascaded ΣΔ modulator. The calibration algorithm matches the digital noise cancellation filter coefficients with the integrator time constants of the analog loop filters, resulting in an optimal signal-to-quantization noise ratio. The calibration method that is proposed is based on a two-point variance estimation of the idling output data stream when zero input signals are applied. This calibration is highly insensitive to the large spread of the variance, due to the pseudo random nature of a ΣΔ modulator. The main advantages of this calibration method are the very high accuracy and very fast calibration speed, while the additional hardware costs are negligible. A 0.18mum CMOS prototype test chip has been fabricated and the measured calibration time is 0.6ms for a 10MHz, 67dB dynamic range continuous-time cascaded ΣΔ modulator.
QoS and service continuity in 3GPP D2D for IoT and wearables (2017)

Device-to-Device (D2D) communications have been already playing a relevant role in 3GPP for several releases of the LTE standard. This paper first shortly introduces how D2D was brought into 3GPP standards and how it evolved, starting from direct discovery and communication between devices being specified in Release 12, through UE-to-Network relaying feature introduction in Release 13, up to vehicle-to-vehicle (V2V) communications support in Release 14. Currently, the versatility of D2D communications has led to consideration of its inherent advantages also in the context of IoT and wearable devices, where the priority is to provide low power connectivity via short-range communications. In this context, there are use cases that can take advantage of UE-relayed communication that capitalizes on the LTE QoS framework. After highlighting the limitations of the currently standardized UE-to-Network relay feature and introducing the enhanced relay architecture being developed in Release 15, the paper discusses the challenges related to end-to-end QoS support in UE-relayed communications, and presents an enhancement to the current standard for dynamic split and allocation of packet delay budget in each hop of the relayed connection. Afterwards, the focus moves to QoS support in mobility scenarios, where path switch between relayed and non-relayed communication might be required while ensuring service continuity, which proves to be a challenging task. Several solutions that trade-off signaling overhead, buffer size requirements and suitability to high-mobility scenarios are presented and explained in detail.
High resolution OCT imaging using a spectrally broadened femtosecond Nd:glass laser (2003)

Summary from only given. We demonstrate a new light source for OCT using a compact Nd:glass femtosecond laser spectrally broadened in a tapered single mode fiber. A reflective grating phase delay line permits high speed, broad bandwidth optical delay scanning. High speed and high resolution OCT imaging is achieved with 5 /spl mu/m axial resolution and 90 dB sensitivity. Axial scan speeds of 1 m/s are achieved, sufficient for real time imaging. This laser source is compact and is well suited for high resolution clinical imaging studies.
A state‐space Bayesian framework for estimating biogeochemical transformations using time‐lapse geophysical data (2009)

We develop a state‐space Bayesian framework to combine time‐lapse geophysical data with other types of information for quantitative estimation of biogeochemical parameters during bioremediation. We consider characteristics of end products of biogeochemical transformations as state vectors, which evolve under constraints of local environments through evolution equations, and consider time‐lapse geophysical data as available observations, which could be linked to the state vectors through petrophysical models. We estimate the state vectors and their associated unknown parameters over time using Markov chain Monte Carlo sampling methods. To demonstrate the use of the state‐space approach, we apply it to complex resistivity data collected during laboratory column biostimulation experiments that were poised to precipitate iron and zinc sulfides during sulfate reduction. We develop a petrophysical model based on sphere‐shaped cells to link the sulfide precipitate properties to the time‐lapse geophysical attributes and estimate volume fraction of the sulfide precipitates, fraction of the dispersed, sulfide‐encrusted cells, mean radius of the aggregated clusters, and permeability over the course of the experiments. Results of the case study suggest that the developed state‐space approach permits the use of geophysical data sets for providing quantitative estimates of end‐product characteristics and hydrological feedbacks associated with biogeochemical transformations. Although tested here on laboratory column experiment data sets, the developed framework provides the foundation needed for quantitative field‐scale estimation of biogeochemical parameters over space and time using direct, but often sparse wellbore data with indirect, but more spatially extensive geophysical data sets.
Contribution of BlaA and BlaB β-Lactamases to Antibiotic Susceptibility of Yersinia enterocolitica Biovar 1B (2010)

Highly pathogenic Yersinia enterocolitica biovar 1B produces two distinct beta-lactamases, BlaA and BlaB. Mutants of a representative biovar 1B isolate were constructed and evaluated to determine the extent of limitation of susceptibility to broad-spectrum beta-lactam antibiotics by BlaA and BlaB. The results demonstrated that BlaA, a class A enzyme, plays a significant role in limiting susceptibility to penicillins and cephalosporins. The contribution of BlaB, a class C enzyme, was less profound and was limited primarily to cephalosporin susceptibility.
Superposition by Position (2006)

We present a novel method for superposition coding applicable to OFDM systems in which the receivers being transmitted to are one high SNR receiver and one low SNR receiver. The degradation of the high SNR receiver, however, results primarily from channel uncertainty. Thus, we consider the effect of imperfect channel estimates, a ubiquitous problem in mobile wireless, and show that the new scheme performs much better than traditional schemes in such a setting.
A novel NOD-derived murine model of primary Sj�gren's syndrome (1998)

The results of this study suggest that the unique NOD MHC I-A(g7) is not essential for exocrine tissue autoimmunity. Furthermore, the findings indicate that sicca syndrome occurs independently of autoimmune diabetes and that the congenic NOD.B10.H2b mouse represents a novel murine model of primary SS.
Quantitative imaging of graphene impedance with the near-field scanning microwave microscope. (2010)

Graphene has emerged as a promising material for high speed nano-electronics due to the relatively high carrier mobility that can be achieved. To further investigate electronic transport in graphene and reveal its potential for microwave applications, we employed a near-field scanning microwave microscope with the probe formed by an electrically open end of a 4 GHz half-lambda parallel-strip transmission line resonator. Because of the balanced probe geometry, our microscope allows for truly localized quantitative characterization of various bulk and low-dimensional materials, with the response region defined by the one micron spacing between the two metallic strips at the probe tip. The single- and few-layer graphene flakes were fabricated by a mechanical cleavage method on 300-nm-thick silicon dioxide grown on low resistivity Si wafer. The flake thickness was determined using both AFM and Raman microscopies. We observe clear correlation between the near-field microwave and far-field optical images of graphene produced by the probe resonant frequency shift and thickness-defined color gradation, respectively. We show that the microwave response of graphene flakes is determined by the local sheet impedance, which is found to be predominantly active. Furthermore, we apply a quantitative electrodynamic model relating the probe resonant frequency shift to 2D conductivity ofmore » single- and few-layer graphene. From fitting a model to the experimental data we evaluate graphene sheet resistance as a function of thickness. Near-field scanning microwave microscopy can simultaneously image location, geometry, thickness, and distribution of electrical properties of graphene without a need for device fabrication. The approach may be useful for design of graphene-based microwave transistors, quality control of large area graphene sheets, or investigation of chemical and electrical doping effects on graphene transport properties. We acknowledge support from the DOE Center for Integrated Nanotechnologies user support program (grant No.U2008A061), from the NASA NM Space Grant Consortium program, and from the LANL-NMT MOU program supported by UCDRD.« less
Effect of the Trimethylgallium Flow during Nucleation Layer Growth on the Properties of GaN Grown on Sapphire (1996)

We report on the effect of the trimethylgallium flow during nucleation layer growth on the electrical, optical and structural properties of epitaxial GaN films grown on basal plane sapphire by atmospheric pressure metalorganic chemical vapor deposition. The 1.2 µm thick GaN films grown on nucleation layers with the optimum trimethylgallium flow of 45 µmol/min had a room temperature mobility of 644 cm 2 /s and minimum width of the (002) and the (102) X-ray diffraction peaks. The roughness of the as-grown nucleation layers decreased with increased trimethylgallium flow. However, smooth, as-grown, nucleation layers showed a strong tendency for island coarsening and an increased surface roughness after heating to the bulk GaN growth temperature.
Molecular and cytogenetic characterization of expanded B-cell clones from multiclonal versus monoclonal B-cell chronic lymphoproliferative disorders (2014)

Chronic antigen-stimulation has been recurrently involved in the earlier stages of monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The expansion of two or more B-cell clones has frequently been reported in individuals with these conditions; potentially, such coexisting clones have a greater probability of interaction with common immunological determinants. Here, we analyzed the B-cell receptor repertoire and molecular profile, as well as the phenotypic, cytogenetic and hematologic features, of 228 chronic lymphocytic leukemia-like and non-chronic lymphocytic leukemia-like clones comparing multiclonal (n=85 clones from 41 cases) versus monoclonal (n=143 clones) monoclonal B-cell lymphocytosis, chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders. The B-cell receptor of B-cell clones from multiclonal cases showed a slightly higher degree of HCDR3 homology than B-cell clones from mono clonal cases, in association with unique hematologic (e.g. lower B-lymphocyte counts) and cytogenetic (e.g. lower frequency of cytogenetically altered clones) features usually related to earlier stages of the disease. Moreover, a subgroup of coexisting B-cell clones from individual multiclonal cases which were found to be phylogenetically related showed unique molecular and cytogenetic features: they more frequently shared IGHV3 gene usage, shorter HCDR3 sequences with a greater proportion of IGHV mutations and del(13q14.3), than other unrelated B-cell clones. These results would support the antigen-driven nature of such multiclonal B-cell expansions, with potential involvement of multiple antigens/epitopes.
Functional Neurons Generated from T Cell-Derived Induced Pluripotent Stem Cells for Neurological Disease Modeling (2016)

Modeling of neurological diseases using induced pluripotent stem cells (iPSCs) derived from the somatic cells of patients has provided a means of elucidating pathogenic mechanisms and performing drug screening. T cells are an ideal source of patient-specific iPSCs because they can be easily obtained from samples. Recent studies indicated that iPSCs retain an epigenetic memory relating to their cell of origin that restricts their differentiation potential. The classical method of differentiation via embryoid body formation was not suitable for T cell-derived iPSCs (TiPSCs). We developed a neurosphere-based robust differentiation protocol, which enabled TiPSCs to differentiate into functional neurons, despite differences in global gene expression between TiPSCs and adult human dermal fibroblast-derived iPSCs. Furthermore, neurons derived from TiPSCs generated from a juvenile patient with Parkinson's disease exhibited several Parkinson's disease phenotypes. Therefore, we conclude that TiPSCs are a useful tool for modeling neurological diseases.
BCL2 Overexpression in Diffuse Large B-Cell Lymphoma (1999)

Translocation (14;18)(q32;q21), which is detected in 20-30% of diffuse large B-cell lymphomas (DLBCL), is regarded as a major mechanism for BCL2 protein overexpression. Nevertheless, BCL2 overexpression is not always caused by t(14;18), because it is often detected in lymphomas without BCL2 rearrangement. Recent studies have shown that increased expression of BCL2 may also result from BCL2 gene amplification in DLBCL. Similarly, it has been speculated that the mutations of the open reading frame might cause increased expression of BCL2 by affecting the interactions of BCL2 with other proteins. The results obtained from studies on the association of BCL2 protein overexpression with survival of DLBCL are controversial, although a correlation with decreased overall survival seems to exist. However, BCL2 rearrangement does not seem to have any major association with poor prognosis, but it is difficult to assess its true impact on prognosis due to differences in treatment and follow-up, and methodologies applied to study the BCL2 rearrangement. This review summarizes the BCL2 expression studies in DLBCL and discusses the prognostic relevance of BCL2 overexpression and its mechanisms.
Progress in building a cognitive vision system (2016)

We are building a cognitive vision system for mobile robots that works in a manner similar to the human vision system, using saccadic, vergence and pursuit movements to extract information from visual input. At each fixation, the system builds a 3D model of a small region, combining information about distance, shape, texture and motion to create a local dynamic spatial model. These local 3D models are composed to create an overall 3D model of the robot and its environment. This approach turns the computer vision problem into a search problem whose goal is the acquisition of sufficient spatial understanding for the robot to succeed at its tasks. The research hypothesis of this work is that the movements of the robot’s cameras are only those that are necessary to build a sufficiently accurate world model for the robot’s current goals. For example, if the goal is to navigate through a room, the model needs to contain any obstacles that would be encountered, giving their approximate positions and sizes. Other information does not need to be rendered into the virtual world, so this approach trades model accuracy for speed.
Nonlinear Interactive Stories as an Educational Resource (2022)

Working with digitized cultural heritage is an important aspect of education. This article offers research on the interaction of pupils and teachers with digitized cultural heritage processed in the Twine2 environment, focusing on exploring the potential use of digital nonlinear stories in the teaching of humanities in high schools. The aim of this study is to describe the design process that led to the creation of 16 innovative educational resources, and to present the results of their pilot testing and evaluation, which subsequently took place among participating teachers and pupils. For the evaluation, we used a mix of design methods, combining a quantitative and qualitative approach. Both the teachers and the pupils were asked about their experience and takeaways from the interaction with the resources offered. The findings show that presenting educational content in the form of a nonlinear interactive story is a suitable alternative to the traditional frontal educational approach, as both teachers and pupils perceived the resources as intuitive, appealing, and effective in helping to achieve the set educational goals. The study also highlights some key recommendations for future designers of nonlinear interactive stories, which emerged from the respondents’ feedback.
The Smartest Materials: The Future of Nanoelectronics in Medicine (2012)

Electronics have become central to many aspects of biomedicine, ranging from fundamental biophysical studies of excitable tissues to medical monitoring and electronic implants to restore limb movement. The development of new materials and approaches is needed to enable enhanced tissue integration, interrogation, and stimulation and other functionalities. Nanoscale materials offer many avenues for progress in this respect. New classes of molecular-scale bioelectronic interfaces can be constructed using either one-dimensional nanostructures, such as nanowires and nanotubes, or two-dimensional nanostructures, such as graphene. Nanodevices can create ultrasensitive sensors and can be designed with spatial resolution as fine as the subcellular regime. Structures on the nanoscale can enable the development of engineered tissues within which sensing elements are integrated as closely as the nervous system within native tissues. In addition, the close integration of nanomaterials with cells and tissues will also allow the development of in vitro platforms for basic research or diagnostics. Such lab-on-a-chip systems could, for example, enable testing of the effects of candidate therapeutic molecules on intercellular, single-cell, and even intracellular physiology. Finally, advances in nanoelectronics can lead to extremely sophisticated smart materials with multifunctional capabilities, enabling the spectrum of biomedical possibilities from diagnostic studies to the creation of cyborgs.
Application-Controlled Physical Memory using External Page-Cache Management (1992)

No abstract available.
P2P-Based VOD Content Distribution Platform with Guaranteed Video Quality (2010)

In this paper, we propose a P2P-based content distribution mechanism for video-on-demand service in IPTV. Different from traditional P2P-based content distribution mechanisms, our solution mainly focuses on how telecom operators utilize P2P technology to construct/enhance their own content delivery network for IPTV. The proposed mechanism takes into account the influence on the design of P2P mechanism by the unique properties of the IPTV scenario, and tries to enhance the P2P-based service by utilizing the support of network QoS and server resources. Simulation results show that our solution can achieve good scalability while providing guaranteed video quality.
ChemInform Abstract: Diastereoselective Synthesis of γ‐Butyrolactones from Enones Mediated or Catalyzed by a Titanocene Complex. (1996)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Multi-stage PASOTRON experiments (2002)

A two-stage, phase-locked backward wave oscillator was demonstrated to produce a peak output power level of 73.5 kW, which is 97.5% more power than a comparable single stage device. The X-band output frequencies range from 7.4 to 8.4-GHz, for a tunable bandwidth of 12%. The RF output pulses are 85 /spl mu/s in length. This device makes use of the novel PASOTRON (Plasma-Assisted, Slow-Wave Oscillator) technology for beam confinement to reduce the physical weight of the device, rather than using conventional magnetic beam confinement. This experimental research demonstrates the first phase locked multi-stage BWO, characterizes a BWO's performance as a function of length and number of stages, and documents improved multi-stage oscillator performance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>