gebhart/patrepeval huggingface dataset:
Removal of CSF pixels on brain MR perfusion images using first several images and Otsu's thresholding technique (2010)

Brain MR perfusion imaging is used to evaluate local perfusion in patients with cerebral vascular disease. Quantitative measurements on the hemodynamic parameters and volume of brain with abnormal perfusion provide an estimation of the severity of the brain perfusion defect. However, quantitative measurements of these focal cerebral hemodynamic parameters are limited by the presence of cerebrospinal fluid (CSF) pixels. We noticed that the CSF has a higher signal than other tissue types on the first perfusion image, which is usually discarded in routine parametric image calculations. This signal difference, however, can be used to segment CSF pixels on the perfusion images. An image division was used to generate ratio images to compensate for spatially dependent signal variation caused by the inhomogeneity of excitation radiofrequency field. By applying an appropriate signal threshold to the ratio images, CSF pixels can be identified and removed from the parametric images. With the removal of CSF pixels, the volume of delayed-perfusion brain parenchyma can be better visualized and the interference from the CSF can be avoided. The proposed technique is simple, fast, automatic, and effective, and no extra scanning is needed to use this technique.
A framework for specifying, modeling, implementation and verification of SOC protocols (2014)

We are presenting a hybrid verification framework to design, verify and implement SOC protocols. The framework is based on the creation of specifications in terms of extended state transition tables, creation of templates for different phases of the design cycle and integration of these components in a design flow. The resultant design flow presents a tight integration of the debug/verification loop across different design stages that in turn reduce the time to market of the chip. This framework was applied to the design process of multiple SOC chips' production and the results have shown measurable enhancements.
Harmonic characterization of mismatches in deep sub-micron varactors for a digitally controlled RF oscillator (2005)

Precise modeling and understanding of all nonlinear characteristics in radio-frequency (RF) CMOS circuits is a pre-requisite to the successful integration of modern CMOS radios. This paper summarizes a harmonic characterization techniques used to estimate the mismatches in the minimal size inversion-type CMOS tuning varactors of a digitally controlled RF oscillator (DCO). The DCO is the centerpiece of the first ever all-digital phase locked loop (ADPLL) fabricated in 90 nm digital CMOS that meets the challenging GSM performance specifications. Full-scale VHDL simulations as well as lab measurements confirm that the tracking bank varactors have a better than 5% mismatch, thus contributing to the excellent modulation performance of the RF chip
High Thermoelectric Performance in PbTe Due to Large Nanoscale Ag<sub>2</sub>Te Precipitates and La Doping (2010)

Abstract Thermoelectrics are being rapidly developed for waste heat recovery applications, particularly in automobiles, to reduce carbon emissions. PbTe‐based materials with small (<20 nm) nanoscale features have been previously shown to have high thermoelectric figure‐of‐merit, zT, largely arising from low lattice thermal conductivity particularly at low temperatures. Separating the various phonon scattering mechanisms and the electronic contribution to the thermal conductivity is a serious challenge to understanding, and further optimizing, these nanocomposites. Here we show that relatively large nanometer‐scale (50–200 nm) Ag 2 Te precipitates in PbTe can be controlled according to the equilibrium phase diagram and these materials show intrinsic semiconductor behavior with high electrical resistivity, enabling direct measurement of the phonon thermal conductivity. This study provides direct evidence that even large nanometer‐scale microstructures reduce thermal conductivity below that of a macro‐scale composite of saturated alloys with Kapitza‐type interfacial thermal resistance at the same overall composition. Carrier concentration control is achieved with lanthanum doping, enabling independent control of the electronic properties and microstructure. These materials exhibit lattice thermal conductivity which approaches the theoretical minimum above ∼650 K, even lower than that found with small nanoparticles. Optimally La‐doped n ‐type PbTe‐Ag 2 Te nanocomposites exhibit zT > 1.5 at 775 K.
Maximum entropy and maximum likelihood criteria for feature selection from multivariate data (2002)

We discuss several numerical methods for optimum feature selection for multivariate data based on maximum entropy and maximum likelihood criteria. Our point of view is to consider observed data x/sup 1/, x/sup 2/,..., x/sup N/ in R/sup d/ to be samples from some unknown pdf P. We project this data onto d directions, subsequently estimate the pdf of the univariate data, then find the maximum entropy (or likelihood) of all multivariate pdfs in R/sup d/ with marginals in these directions prescribed by the estimated univariate pdfs and finally maximize the entropy (or likelihood) further over the choice of these directions. This strategy for optimal feature selection depends on the method used to estimate univariate data.
Novel optoelectronic single quantum well devices based on electron bleaching of exciton absorption (1987)

Novel planar optoelectronic devices with two-dimensional exciton absorption controlled by free-carrier-induced bleaching are proposed. Exciton-resonant light propagates along a single mode rib waveguide containing a single quantum well (SQW), the only absorbing medium in the waveguide. Three such devices operating as optical modulators are (1) a gate-controlled field-effect transistor optical modulator (FETOM), (2) an optically readable memory element, and (3) an optically switched charge storage device. The FETOM, in which free-carrier density in the SQW is controlled by gate voltage, offers high speed (37.5 ps), small size (125 μm), and low power (86 nW/MHz).
Preclinical Testing of Human Recombinant von Willebrand Factor: ADAMTS13 Cleavage Capacity in Animals as Criterion for Species Suitability (2010)

Von Willebrand factor (VWF) is cleaved by the plasma metalloprotease ADAMTS13 ( A Disintegrin and Metalloproteinase with Thrombo Spondin repeats, number 13) that regulates the hemostatic activity of VWF by limiting its multimeric size in the human system. In vitro and ex vivo studies have shown that human recombinant VWF (rVWF) is virtually resistant to the proteolytic activity of murine ADAMTS13. In contrast, rabbit and cynomolgus ADAMTS13 is able to cleave human rVWF. These findings were consistent with in vivo results showing distinct pharmacological behavior of human rVWF depending on the cleaving capacity of ADAMTS13 present in the species tested. Studies were performed using three mouse strains (ADAMTS13 deficient, C57BL/6J [wild type], VWF deficient), rats, rabbits, and cynomolgus monkeys. All animals were infused once with different doses of human rVWF and, in addition, 14 daily doses were given to rats and cynomolgus monkeys. Exaggerated pharmacological effects were observed in mice, with the ADAMTS13 knockout mouse being the most sensitive strain. Similar findings with decreased incidence and severity were seen in normal C57BL/6J mice and also in VWF-deficient mice, where they were least pronounced. In rats, exaggerated pharmacological effects were observed only after 14 doses. Rabbits and cynomolgus monkeys showed no exaggerated pharmacological effects. These differences between species and between mouse strains suggest that the efficiency of ADAMTS13 to cleave rVWF determines the severity of clinical, laboratory and pathohistological findings. These observations highlight the importance of evaluating species' suitability for the generation of meaningful preclinical data for determining the therapeutic safety margins for human patients. Only animals with a sufficient rVWF cleavage capacity by endogenous ADAMTS13 (rabbits and cynomolgus monkeys) are considered appropriate animal models for preclinical evaluation of the rVWF product.
Enantioselective Epoxidation of Terminal Alkenes to (<i>R</i>)‐ and (<i>S</i>)‐Epoxides by Engineered Cytochromes P450 BM‐3 (2005)

Cytochrome P450 BM-3 from Bacillus megaterium was engineered for enantioselective epoxidation of simple terminal alkenes. Screening saturation mutagenesis libraries, in which mutations were introduced in the active site of an engineered P450, followed by recombination of beneficial mutations generated two P450 BM-3 variants that convert a range of terminal alkenes to either (R)- or (S)-epoxide (up to 83 % ee) with high catalytic turnovers (up to 1370) and high epoxidation selectivities (up to 95 %). A biocatalytic system using E. coli lysates containing P450 variants as the epoxidation catalysts and in vitro NADPH regeneration by the alcohol dehydrogenase from Thermoanaerobium brockii generates each of the epoxide enantiomers, without additional cofactor.
Capacitance based tunable resonators (1998)

We present four electrostatic actuators that tune the stiffness and hence the resonant frequency of a micromechanical oscillator. Using these actuators, resonant frequencies have been reduced to 7.7% and raised to 146% of the original values. These shifts correspond to approximately two orders of magnitude reduction in stiffness and a doubling in stiffness, respectively. Comparisons are drawn between these actuators based on functionality, area utilization efficiency, linearity and stability. Other issues discussed are asymmetries, nonlinearities and failure modes. With regard to the nonlinearities, near the limit of resonant frequency reduction, we show the ability to tune the system into a bistable state.
The bright future: Imaging dynamic cellular events with quantum dots (2010)

Semiconductor quantum dots (QDs) are tiny light-emitting particles that have emerged as a new class of fluorescent labels for biology and medicine. Compared with traditional fluorescent probes, QDs have unique optical and electronic properties such as size-tuneable light emission, narrow and symmetric emission spectra, and broad absorption spectra that enable the simultaneous excitation of multiple fluorescence colours.
ChemInform Abstract: Regioselective Synthesis of 1,3,5‐Tri‐ and 1,3,4,5‐Tetrasubstituted Pyrazoles from N‐Arylhydrazones and Nitroolefins. (2008)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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.
Structural Basis for Variation in Adenovirus Affinity for the Cellular Coxsackievirus and Adenovirus Receptor (2003)

The majority of adenovirus serotypes can bind to the coxsackievirus and adenovirus receptor (CAR) on human cells despite only limited conservation of the amino acid residues that comprise the receptor-binding sites of these viruses. Using a fluorescence anisotropy-based assay, we determined that the recombinant knob domain of the fiber protein from adenovirus serotype (Ad) 2 binds the soluble, N-terminal domain (domain 1 (D1)) of CAR with 8-fold greater affinity than does the recombinant knob domain from Ad12. Homology modeling predicted that the increased affinity of Ad2 knob for CAR D1 could result from additional contacts within the binding interface contributed by two residues, Ser408 and Tyr477, which are not conserved in the Ad12 knob. Consistent with this structural model, substitution of serine and tyrosine for the corresponding residues in the Ad12 knob (P417S and S489Y) increased the binding affinity by 4- and 8-fold, respectively, whereas the double mutation increased binding affinity 10-fold. X-ray structure analysis of Ad12 knob mutants P417S and S489Y indicated that both substituted residues potentially could form additional hydrogen bonds across the knob-CAR interface. Structural changes resulting from these mutations were highly localized, implying that the high tolerance for surface variation conferred by the stable knob scaffold can minimize the impact of antigenic drift on binding specificity and affinity during evolution of virus serotypes. Our results suggest that the interaction of knob domains from different adenovirus serotypes with CAR D1 can be accurately modeled using the Ad12 knob-CAR D1 crystal structure as a template.
Restoring Connectivity in Wireless Sensor-Actor Networks with Minimal Topology Changes (2010)

In Wireless Sensor-Actor Networks (WSANs), actors collect sensor readings and respond collaboratively to achieve an application mission. Since actors coordinate their operation, a strongly connected network topology would be required at all time. In addition, the path between actors may have to be capped in order to meet latency constraints. However, a failure of an actor may cause the network to partition into disjoint blocks and would thus violate such connectivity goal. One of the effective recovery methodologies is to autonomously reposition a subset of the actor nodes to restore connectivity. Contemporary schemes rely on maintaining 1 or 2-hop neighbor lists and predetermine criteria for node's involvement in the recovery. However, 1-hop based schemes often impose high node relocation overhead. In addition, the repaired inter-actor topology using 2-hop schemes often differs significantly from its pre-failure status and some inter-actor data paths may get extended. This paper presents a Least-Disruptive topology Repair (LeDiR) algorithm. LeDiR relies on the local view of a node about the network in order to devise a recovery plan that relocates the least number of nodes and ensures that no path between any pair of nodes is extended. LeDiR is a localized and distributed algorithm that leverages existing path discovery activities and imposes no additional pre-failure communication overhead. LeDiR is validated through simulation and is shown to outperform existing schemes.
Improved Silicon-Growth Chamber (1984)

Silicon-growth technique, based on coating ceramic substrates with thin layer of molten silicon solidifies to form polycrystalline film, modified to produce solar-cell quality silicon sheet.
All at Once: Temporally Adaptive Multi-Frame Interpolation with Advanced Motion Modeling (2020)

Recent advances in high refresh rate displays as well as the increased interest in high rate of slow motion and frame up-conversion fuel the demand for efficient and cost-effective multi-frame video interpolation solutions. To that regard, inserting multiple frames between consecutive video frames are of paramount importance for the consumer electronics industry. State-of-the-art methods are iterative solutions interpolating one frame at the time. They introduce temporal inconsistencies and clearly noticeable visual artifacts. Departing from the state-of-the-art, this work introduces a true multi-frame interpolator. It utilizes a pyramidal style network in the temporal domain to complete the multi-frame interpolation task in one-shot. A novel flow estimation procedure using a relaxed loss function, and an advanced, cubic-based, motion model is also used to further boost interpolation accuracy when complex motion segments are encountered. Results on the Adobe240 dataset show that the proposed method generates visually pleasing, temporally consistent frames, outperforms the current best off-the-shelf method by 1.57db in PSNR with 8 times smaller model and 7.7 times faster. The proposed method can be easily extended to interpolate a large number of new frames while remaining efficient because of the one-shot mechanism.
Novel diagnostic and prognostic classifiers for prostate cancer identified by genome-wide microRNA profiling (2016)

This is the first report of a miRNA signature with significant independent prognostic value demonstrated in three PC patient cohorts.
A fiber optic probe design to measure depth- limited optical properties in-vivo with Low-coherence Enhanced Backscattering (LEBS) Spectroscopy (2012)

Low-coherence enhanced backscattering (LEBS) spectroscopy is an angular resolved backscattering technique that is sensitive to sub-diffusion light transport length scales in which information about scattering phase function is preserved. Our group has shown the ability to measure the spatial backscattering impulse response function along with depth-selective optical properties in tissue ex-vivo using LEBS. Here we report the design and implementation of a lens-free fiber optic LEBS probe capable of providing depth-limited measurements of the reduced scattering coefficient in-vivo. Experimental measurements combined with Monte Carlo simulation of scattering phantoms consisting of polystyrene microspheres in water are used to validate the performance of the probe. Additionally, depth-limited capabilities are demonstrated using Monte Carlo modeling and experimental measurements from a two-layered phantom.
A matrix addressable bistable nematic liquid-crystal display with electric field writing and thermal erasure (1983)

We describe the fabrication and performance of a 20 × 40 element bistable liquid-crystal display using a dye guest in a nematic host. The bistable configuration ensures the long term memory of the written display. The electrical writing procedure together with the use of segmented subpels produces sharp, uniform switching thresholds resulting in clearly written displays with good contrast. Both 2:1 and 3:1 matrix addressing schemes are possible. The thermal erasure scheme is discussed in detail and the influence of the boundary aligning material and the resulting nematic director tilt angle is investigated both theoretically and experimentally. Results are presented for both reflection and transmission displays.
Reflection properties of multimode interference devices (1994)

We report on the reflection properties of multimode interference (MMI) devices: we distinguish between reflection back into the input waveguides and internal resonance modes due to the occurrence of simultaneous self-images. Because of self-imaging, reflection can be extremely efficient, even in the case of MMI devices with optimized transmission. This conclusion is confirmed by the observed spectral behavior of InP-based ring lasers incorporating MMI 3 dB couplers and MMI power splitters. Several techniques are proposed to minimize the influence of these reflections.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Super-Resolution on small moving objects (2008)

Moving objects are often the most interesting parts in image sequences. When images from a camera are undersampled and the moving object is depicted small on the image plane, processing afterwards may help to improve the visibility as well as automatic recognition of the object. This paper presents an approach which performs Super-Resolution (SR) specifically on small moving objects. The presented approach estimates simultaneously a sub-pixel accurate boundary and an intensity description of the small moving object. This approach has the advantage that it permits explicit modeling of the partial volume effect for pixels which are influenced by both the moving object and the background of the scene. This paper describes the setup of the proposed SR algorithm for small moving objects and shows its superior performance in comparison with a standard SR approach.
Engineering the compression of massive tables: an experimental approach (2000)

We study the problem of compressing massive tables. We devise a novel compression paradigm—training for lossless compression— which assumes that the data exhibit dependencies that can be learned by examining a small amount of training material. We develop an experimental methodology to test the approach. Our result is a system, pzip, which outperforms gzip by factors of two in compression size and both compression and uncompression time for various tabular data. Pzip is now in production use in an AT&T network traffic data warehouse.
Bulk minority carrier lifetimes and doping of silicon bricks from photoluminescence intensity ratios (2011)

Two methods for spatially resolved measurement of the bulk minority carrier lifetime on the side faces of block cast silicon bricks, both based on photoluminescence imaging, are presented. The first method uses a single photoluminescence image which is normalized for variations in the background doping density. The second method is based on the measurement of the ratio of two photoluminescence images taken with different spectral filters in front of the CCD camera. This second method is advantageous over the first method since it is not dependent on an absolute measurement of the luminescence intensity and does not require a separate resistivity measurement. It is further demonstrated, that the measurement of an intensity ratio image and comparison of the latter with an individual luminescence image also allow obtaining the doping density gradient within silicon bricks. This paper presents an in-depth analysis of the underlying models, demonstrates experimental results and discusses the calibration and uncertainties of the techniques. Practical limitations and dependencies on various experimental parameters are discussed.
Novel Sparse-Coded Ambient Backscatter Communication for Massive IoT Connectivity (2018)

Low-power ambient backscatter communication (AmBC) relying on radio-frequency (RF) energy harvesting is an energy-efficient solution for batteryless Internet of Things (IoT). However, ambient backscatter signals are severely faded by dyadic backscatter channel (DBC), limiting connectivity in conventional orthogonal time-division-based AmBC (TD-AmBC). In order to support massive connectivity in AmBC, we propose sparse-coded AmBC (SC-AmBC) based on non-orthogonal signaling. Sparse code utilizes inherent sparsity of AmBC where power supplies of RF tags rely on ambient RF energy harvesting. Consequently, sparse-coded backscatter modulation algorithm (SC-BMA) can enable non-orthogonal multiple access (NOMA) as well as M-ary modulation for concurrent backscatter transmissions, providing additional diversity gain. These sparse codewords from multiple tags can be efficiently detected at access point (AP) using iterative message passing algorithm (MPA). To overcome DBC along with intersymbol interference (ISI), we propose dyadic channel estimation algorithm (D-CEA) and dyadic MPA (D-MPA) exploiting weighted-sum of the ISI for information exchange in the factor graph. Simulation results validate the potential of the SC-AmBC in terms of connectivity, detection performance and sum throughput.
INTERNAL ELECTROSTATIC TRANSDUCTION FOR BULK-MODE MEMS RESONATORS (2004)

This paper demonstrates a new approach to electrostatic drive and detection of bulk acoustic resonators in which the electrode-gaps are filled with a high dielectric constant material. Internal electrostatic transduction has much higher efficiency than air-gap electrostatic transduction for bulk-mode resonators, which results in improved electrical performance. As a proof-of-concept, we demonstrate this phenomenon by electrostatic actuation of a 1.9GHz AlN ( ~ 9) film bulk acoustic resonator (FBAR).