gebhart/patrepeval huggingface dataset:
Characterization of Pichinde virus infection of cells of the monocytic lineage (1991)

To establish a model of viral infection of monocytes, we examined infection of human cells and cell lines of the monocytic series with the arenavirus Pichinde virus. We demonstrate for the first time that human peripheral blood monocytes are susceptible to Pichinde virus infection, as shown by immunoprecipatation of virus-specific polypeptides from infected cells, immunofluorescence analyses, and quantitation of virus production from infected cells. The human promyelocytic leukemia cell line HL60 did not support Pichinde virus replication, even if cells were induced with the phorbol ester phorbol myristate acetate (PMA) to differentiate to monocytes. However, the human promonocytic leukemia cell line THP-1 did support Pichinde virus replication. Replication depended on exposure of the cells to PMA. We examined the nature of the effect of PMA in the induction of THP-1 cells to support Pichinde virus replication. We found that 5 min of exposure of THP-1 cells to PMA is sufficient to support virus growth and that PMA-treated THP-1 cells remain susceptible to infection up to 4 days after the initial PMA treatment. We also showed that infection of PMA-treated THP-1 cells is mediated through protein kinase C (PKC). H7, a PKC inhibitor, was able to block both PMA-induced differentiation and Pichinde virus infection of THP-1 cells. The synthetic diacylglycerol and PKC agonist, diC8, was able to stimulate THP-1 cells to support virus growth, albeit to lower levels than PMA. Dactinomycin abrogated the ability of virus to replicate and suggested a requirement for host cell transcription. The PMA effect did not appear to relate to receptor modulation. These results suggest that PMA-induced susceptibility to Pichinde virus infection occurs at a point later than the initial binding and penetration stages and that infection depends on the activation or differentiation state of the cell.
Progress on Shape Memory Alloy Actuator Development for Active Clearance Control (2006)

Results of a numerical analysis evaluating the feasibility of high-temperature shape memory alloys (HTSMA) for active clearance control actuation in the high-pressure turbine section of a modern turbofan engine has been conducted. The prototype actuator concept considered here consists of parallel HTSMA wires attached to the shroud that is located on the exterior of the turbine case. A transient model of an HTSMA actuator was used to evaluate active clearance control at various operating points in a test bed aircraft engine simulation. For the engine under consideration, each actuator must be designed to counteract loads from 380 to 2000 lbf and displace at least 0.033 in. Design results show that an actuator comprised of 10 wires 2 in. in length is adequate for control at critical engine operating points and still exhibit acceptable failsafe operability and cycle life. A proportional-integral-derivative (PID) controller with integrator windup protection was implemented to control clearance amidst engine transients during a normal mission. Simulation results show that the control system exhibits minimal variability in clearance control performance across the operating envelope. The final actuator design is sufficiently small to fit within the limited space outside the high-pressure turbine case and is shown to consume only small amounts of bleed air to adequately regulate temperature.
A 10.35 mW/GFlop stacked SAR DSP unit using fine-grain partitioned 3D integration (2012)

In this paper we present a technique for implementing a fine-grain partitioned three-dimensional SAR DSP system using 3D placement of standard cells where only one of the 3D tiers is clocked to reduce clock power. We show how this technique was used to build the first fine-grain partitioned 3D integrated system to be demonstrated with silicon measurements in the literature, which is an ultra efficient floating-point synthetic aperture radar (SAR) DSP processing unit. The processing unit was fabricated in two tiers of GlobalFoundries, 1.5 V 130nm process that were 3D stacked face-to-face by Tezzaron. After fabrication the test chip was measured to consume 4.14 mW of power while running at 40 MHz operating for an operating efficiency of 10.35 mW/GFlop.
Broad Electrical Tuning of Graphene-Loaded Plasmonic Antennas (2013)

Plasmonic antennas enable the conversion of light from free space into subwavelength volumes and vice versa, which facilitates the manipulation of light at the nanoscale. Dynamic control of the properties of antennas is desirable for many applications, including biochemical sensors, reconfigurable meta-surfaces and compact optoelectronic devices. The combination of metallic structures and graphene, which has gate-voltage dependent optical properties, is emerging as a possible platform for electrically controlled plasmonic devices. In this paper, we demonstrate in situ control of antennas using graphene as an electrically tunable load in the nanoscale antenna gap. In our experiments, we demonstrate electrical tuning of graphene-loaded antennas over a broad wavelength range of 650 nm (∼140 cm(-1), ∼10% of the resonance frequency) in the mid-infrared (MIR) region. We propose an equivalent circuit model to quantitatively analyze the tuning behavior of graphene-loaded antenna pairs and derive an analytical expression for the tuning range of resonant wavelength. In a separate experiment, we used doubly resonant antenna arrays to achieve MIR optical intensity modulation with maximum modulation depth of more than 30% and bandwidth of 600 nm (∼100 cm(-1), 8% of the resonance frequency). This study shows that combining graphene with metallic nanostructures provides a route to electrically tunable optical and optoelectronic devices.
BEXHI: A Mechanical Structure for Prototyping Bendable and EXpandable Handheld Interfaces (2019)

In this paper, we present BEXHI, a new mechanical structure for prototyping expandable and bendable handheld devices. Many research projects have pushed bendable surfaces from prototypes to commercially viable devices. In the meantime, expandable devices have become a topic of interest letting one foresee that such devices are on the horizon. With BEXHI, we provide a structure to explore the combined capabilities of these devices. The structure consists of multiple interweaved units allowing non-porous expandable surfaces to bend. Through an instanciation, we illustrate and discuss that the BEXHI structure allows for the exploration of the combination of both bend and expansion interaction spaces.
Design and performance of a laser-plasma-based compact soft x-ray microscope (2002)

We describe the design of a user-friendly compact water-window x-ray microscope. The microscope is based on a λ=3.37 nm liquid-jet-target laser-plasma source in combination with a normal-incidence multilayer condenser mirror and high-resolution diffractive optics for the imaging. With its high mechanical and thermal stability, the instrument demonstrates enhanced resolution and potential for compact x-ray imaging with the quality of synchrotron-based microscopes. Furthermore, a new sample handling system, computer control, and other improvements facilitate application-oriented x-ray microscopy outside the synchrotron laboratory.
Membership-based multiprotocol MR brain image segmentation (2003)

A simple,non-iterative,membership-based method for multiprotocol brain magnetic resonance image segmentation has been developed. The intensity in homogeneity correction and MR intensity standardization techniques are used first to make the MR image intensities have a tissue-specific meaning. The mean intensity vector and covariance matrix of each brain tissue are then estimated and fixed. Vectorial scale-based fuzzy connectedness and certain morphological operations are utilized to geernate the brain intracranial mask. The fuzzy membership value of each voxel for each brain tissue is then estimated within the intracranial mask via a multivariate Gaussian model. Finally, a maximum likelihood criterion with spatial constraints taken into account is utilized in classifying all voxels in the intracranial mask into gray matter, white matter, and cerebrospinal fluid. This method has been tested on 10 clinical MR data sets. These tests and a comparison with the method of C-means and fuzzy C-means clustering indicated the effectiveness of the method.
Releasable Layer-by-Layer Assembly of Stabilized Lipid Nanocapsules on Microneedles for Enhanced Transcutaneous Vaccine Delivery (2012)

Here we introduce a new approach for transcutaneous drug delivery, using microneedles coated with stabilized lipid nanocapsules, for delivery of a model vaccine formulation. Poly(lactide-co-glycolide) microneedle arrays were coated with multilayer films via layer-by-layer assembly of a biodegradable cationic poly(β-amino ester) (PBAE) and negatively charged interbilayer-cross-linked multilamellar lipid vesicles (ICMVs). To test the potential of these nanocapsule-coated microneedles for vaccine delivery, we loaded ICMVs with a protein antigen and the molecular adjuvant monophosphoryl lipid A. Following application of microneedle arrays to the skin of mice for 5 min, (PBAE/ICMV) films were rapidly transferred from microneedle surfaces into the cutaneous tissue and remained in the skin following removal of the microneedle arrays. Multilayer films implanted in the skin dispersed ICMV cargos in the treated tissue over the course of 24 h in vivo, allowing for uptake of the lipid nanocapsules by antigen presenting cells in the local tissue and triggering their activation in situ. Microneedle-mediated transcutaneous vaccination with ICMV-carrying multilayers promoted robust antigen-specific humoral immune responses with a balanced generation of multiple IgG isotypes, whereas bolus delivery of soluble or vesicle-loaded antigen via intradermal injection or transcutaneous vaccination with microneedles encapsulating soluble protein elicited weak, IgG(1)-biased humoral immune responses. These results highlight the potential of lipid nanocapsules delivered by microneedles as a promising platform for noninvasive vaccine delivery applications.
Human cytomegalovirus-specific cytotoxic T cells: their precursor frequency and stage specificity (1988)

Human virus-specific cytotoxic T (Tc) cells may be important in maintaining the virus/host equilibrium during persistent herpes virus infections such as that with human cytomegalovirus (HCMV). We have previously shown that HCMV-specific Tc cells are present in peripheral blood in normal asymptomatic seropositive individuals (L. K. Borysiewicz et al., Eur. J. Immunol. 1983. 13: 804). In this study we have used limiting dilution analysis to estimate the precursor frequency of these Tc cells and to further delineate their specificity for viral proteins expressed at different stages of the virus replicative cycle. HCMV-specific Tc precursor cells were present in peripheral blood lymphocytes (PBL) at a frequency of 1/5000 to 20,000 E+ PBL. This frequency was higher than that observed for varicella-zoster virus (VZV)-specific Tc cells (1/30,000 to greater than 500,000) in asymptomatic individuals and was similar to the VZV Tc precursor cell frequencies observed following clinical reactivation (1/30,000). When the stage specificity of clonally derived HCMV-specific Tc cells was analyzed, using target cells treated with phosphonoformate to allow expression of only the nonstructural viral proteins, the majority (60%) of Tc cells lysed these cells. A number of Tc cells lysed only cells which expressed the structural or late HCMV proteins. These results suggest a high precursor frequency of HCMV-specific Tc cells in PBL, and that there are subpopulations of such Tc cells specific for HCMV antigens expressed at different stages of the virus replicative cycle. However, the relative frequencies of these subpopulations suggest that the immunodominant HCMV antigens with respect to the Tc response are expressed at immediate early and/or early times.
Understanding How Work Habits influence Student Performance (2019)

Understanding the relationship between a student's broader work habits and their performance, particularly on open-ended programming assignments, is key towards being able to guide students towards success. In spite of this, most evidence of student behavior and its relationship to performance is anecdotal. The advent of large-scale courses which use online tools for delivering course content, monitoring the programming environment, and providing automatic feedback as well as grading now makes it possible to dive into the data and develop data-driven methods for understanding how a student's approach to an assignment---from their first exposure to the description of the problem to their final submission of their completed assignment---influences their final performance.
Continuous electrowetting via electrochemical diodes (2011)

We describe a novel method for droplet transport combining electrowetting on dielectric (EWOD) and the diode-like behavior of valve metals to achieve unique actuation performance. While traditional EWOD droplet transport requires switching of voltage between multiple electrodes, our method, which we term continuous rectified electrowetting, utilizes a simple single electrode and a DC voltage to move a 50 μl droplet 28 mm with velocities up to 32 mm s(-1).
Wide-angle decentered lens beam steering for infrared countermeasures applications (2004)

A beam-steering system consisting of three cemented achromatic doublets is presented. Intended for use in IR countermeasure applications, our system is designed to operate over the 2- to 5-µm spectrum with minimum angular dispersion. We show that dispersion can be minimized by using doublet lenses fashioned from AMTIR-1 and germanium. Our system is designed to be compact and lightweight, with no internal foci, while allowing steering to ±22.5 deg. We also maintain a minimum 2-in. clear aperture for all steering angles, and a nominal divergence of 1 mrad. Plane wave and Gaussian beam analyses of our system are presented.©
Progranulin in frontotemporal lobar degeneration and neuroinflammation (2007)

Progranulin (PGRN) is a pleiotropic protein that has gained the attention of the neuroscience community with recent discoveries of mutations in the gene for PGRN that cause frontotemporal lobar degeneration (FTLD). Pathogenic mutations in PGRN result in null alleles, and the disease is likely the result of haploinsufficiency. Little is known about the normal function of PGRN in the central nervous system apart from a role in brain development. It is expressed by microglia and neurons. In the periphery, PGRN is involved in wound repair and inflammation. High PGRN expression has been associated with more aggressive growth of various tumors. The properties of full length PGRN are distinct from those of proteolytically derived peptides, referred to as granulins (GRNs). While PGRN has trophic properties, GRNs are more akin to inflammatory mediators such as cytokines. Loss of the neurotrophic properties of PGRN may play a role in selective neuronal degeneration in FTLD, but neuroinflammation may also be important. Gene expression studies suggest that PGRN is up-regulated in a variety of neuroinflammatory conditions, and increased PGRN expression by microglia may play a pivotal role in the response to brain injury, neuroinflammation and neurodegeneration.
Visible Light Photocatalytic Thiol–Ene Reaction: An Elegant Approach for Fast Polymer Postfunctionalization and Step-Growth Polymerization (2015)

An elegant approach for fast polymer postfunctionalization and step-growth polymerization (via addition reaction) under aerobic condition was developed from visible light photocatalytic thiol–ene "click" reaction, employing Ru(bpy)3Cl2 as photoredox catalyst and p-toluidine as redox mediator. The nature of the photoredox catalysts, thiol substrates, and solvents were extensively investigated for this reaction with two types of alkene polymers: polybutadiene and poly(allyl methacrylate)s. The use of N-methyl-2-pyrrolidone as the solvent and p-toluidine as redox mediator remarkably improved the reaction rates and limited the formation of side products. Finally, this highly efficient thiol–ene reaction was employed for the synthesis of polymers by step-growth addition polymerization.
500-V n-channel insulated-gate bipolar transistor with a trench gate structure (1989)

An improved insulated-gate bipolar transistor (IGBT) with a trench gate structure that demonstrates a low forward voltage drop of 1.2 V at a forward conduction current density of 200 A/cm/sup 2/ is described. This device structure was fabricated using a self-aligned process that permits closely spaced vertical trench gates with a unit cell of 6 mu m. This allows for a fivefold increase of channel density and elimination of the parasitic JFET effect, thus reducing the forward voltage drop significantly. A static latching current density of 2700 A/cm/sup 2/ has been achieved in the UMOS-IGBT. Two-dimensional computer simulations of the UMOS-IGBT have been performed to identify the optimal cell design. This optimal design is predicted to increase the SOA current density by a factor of 2.9 over the state-of-the-art DMOS-IGBT.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Red or green: Analyzing the data delivery with traffic lights in vehicular ad hoc networks (2014)

The data delivery in Vehicular Ad Hoc Networks (VANETs) depends on the mobility of the vehicles (e.g. with carry-and-forward). However, the mobility of the vehicles is not only affected by the nodes themselves, but also by some external means such as the traffic lights. The red light stops the vehicles at the intersection, which will increase the delivery delay of the messages carried by the vehicle with waiting time. On the contrary, this may also increase the opportunities of vehicles moving behind to catch up in forwarding messages. In this paper, we investigate the negative and positive influences of the traffic lights on data delivery in VANETs. We develop an analysis model for evaluating the data delivery among the vehicles that move along a path with multiple traffic lights. Based on the model, vehicles can estimate the reachability of destinations and the data delivery delay. Thus, we propose a transmission control scheme by the given deadline of reachable destinations, in order to improve the data delivery. Our intensive simulations verify the proposed model, and evaluate the influence of the traffic lights on data delivery.
Source separation of Foetal Heart Sounds and maternal activity from single-channel phonograms: A temporal independent component analysis approach (2008)

Here we successfully extracted sources from noisy single-channel abdominal phonograms. First, an appropriate matrix of delays was constructed; then multiple independent components were calculated using TDSEP; finally, components were projected back onto the measurement space and grouped using K-means. Three single-channel phonograms from different subjects were analysed. Results showed a better-quality and more objective extraction of Foetal Heart Sounds (S1-S2), maternal activity and line-noise by using this temporal independent approach (versus a FastICA version). Future work will look for extracting more sources and a robust method to measure the quality of the extraction.
Quality of High Resolution Synthesised Images: Is there a Simple Criterion (2000)

International audience
Molten Carbonates as an Effective Oxygen Reduction Catalyst for 550–650°C Solid Oxide Fuel Cells (2013)

We report the first study that investigates the use of molten carbonates as an effective catalyst to promote electrochemical oxygen reduction reaction (ORR) at the cathode of intermediate temperature solid oxide fuel cells (IT-SOFCs). A series of binary Li-K carbonate compositions were incorporated into the porous backbones of a commercial cathode assembled in symmetrical impedance cells for electrochemical characterization. Within the temperature range of 550–650°C, we observed that the polarization and ohmic area-specific resistances of the original sample can be significantly reduced by the introduction of molten carbonates. A new ORR charge-transfer model involving two intermediate species CO52− and CO42− as the fast oxygen absorber and transporter, respectively, was presented as the mechanism for the facile ORR kinetics promoted by molten carbonates.
Hybridization of oligodeoxynucleotide with redox coenzyme model; Synthesis and properties of thymidine decamers covalently linked to 5-deazaflavin. (1992)

Modified thymidine decamers covalently linked to 5-deazaflavin derivatives through aminoalkyl spacer arm in the form of phosphoramidate bond, were prepared and characterized, Chemical and physical properties of the hydrid moleculeas are discussed.
Insights into Early Extracellular Matrix Evolution: Spongin Short Chain Collagen-Related Proteins Are Homologous to Basement Membrane Type IV Collagens and Form a Novel Family Widely Distributed in Invertebrates (2006)

Collagens are thought to represent one of the most important molecular innovations in the metazoan line. Basement membrane type IV collagen is present in all Eumetazoa and was found in Homoscleromorpha, a sponge group with a well-organized epithelium, which may represent the first stage of tissue differentiation during animal evolution. In contrast, spongin seems to be a demosponge-specific collagenous protein, which can totally substitute an inorganic skeleton, such as in the well-known bath sponge. In the freshwater sponge Ephydatia mülleri, we previously characterized a family of short-chain collagens that are likely to be main components of spongins. Using a combination of sequence- and structure-based methods, we present evidence of remote homology between the carboxyl-terminal noncollagenous NC1 domain of spongin short-chain collagens and type IV collagen. Unexpectedly, spongin short-chain collagen-related proteins were retrieved in nonsponge animals, suggesting that a family related to spongin constitutes an evolutionary sister to the type IV collagen family. Formation of the ancestral NC1 domain and divergence of the spongin short-chain collagen-related and type IV collagen families may have occurred before the parazoan-eumetazoan split, the earliest divergence among extant animal phyla. Molecular phylogenetics based on NC1 domain sequences suggest distinct evolutionary histories for spongin short-chain collagen-related and type IV collagen families that include spongin short-chain collagen-related gene loss in the ancestors of Ecdyzosoa and of vertebrates. The fact that a majority of invertebrates encodes spongin short-chain collagen-related proteins raises the important question to the possible function of its members. Considering the importance of collagens for animal structure and substratum attachment, both families may have played crucial roles in animal diversification.