gebhart/patrepeval huggingface dataset:
Tailoring double-wall carbon nanotubes? (2003)

Double‐wall carbon nanotubes (DWNTs) are interesting nano‐objects derived from single‐wall nanotubes (SWNTs) whose potentiality for some applications (such as composite reinforcement) are even more promising than for SWNTs. Depending on the respective chirality of the inner and outer SWNTs involved, electronic properties may also vary, with subsequent possible applications in nanotechnology. Up to now, DWNTs were prepared either from catalytically‐enhanced thermal cracking of gaseous hydrocarbons, electric arc, or thermal annealing of C60@SWNTs (peapods). A drawback of the former as opposed to the latter is that DWNTs hardly concern the whole nanotube production as far as they are always mixed with SWNTs and other MWNTs. Whatever, in any DWNT (or MWNT) from the literature so far, the graphene‐graphene distance looks about equal to the d002‐spacing in turbostratic, polyaromatic carbon, i.e., ∼0.34 nm. For peapod‐derived DWNTs prepared from regular 1.35 nm wide SWNTs, for instance, it means that the inner diameter is ∼0.7 nm, i.e. that of the former contained C60 molecules before coalescence. We report here the unexpected experimental observation that the inter‐tube distance and/or the inner tube diameter of DWNTs prepared from peapods by combining both electron irradiation and heating may possibly vary. This is likely to interestingly bring variations to the overall electronic properties of DWNTs. On the other hand, it would allow the preparation of SWNTs (the inner tube) with diameters narrower than 0.7 nm, for which no common route exists yet.
A Novel Framework of Speckle Reducing Scan Conversion in Ultrasound Imaging Systems (2017)

The resolutions and speckle noise in ultrasound imaging systems are the dominant issues which reduce the efficiency of the system. In conventional speckle reduction techniques, speckle filters are applied either on the scan data in pre-processing stage before scan conversion or on the scan-converted image as post-processing operation. It is observed that the output image quality is better if filtering is applied in the pre-processing stage, but it increases computational load since the amount of data to be handled is larger. Furthermore, after filtering the noise from the data, interpolation is performed for scan conversion. All popular existing speckle reduction filters can be adopted in either of these frameworks. In this article, a new framework is proposed for speckle reduction, where scan conversion and speckle reduction are performed simultaneously. This novel framework reduces the overall computation of the ultrasound imaging system which makes it suitable for real-time applications. Several speckle reduction algorithms can be adopted by this new framework. The performance of the new paradigm is compared with existing frameworks by applying some prevalent filters. The quantitative and qualitative results confirm the superiority of the proposed framework with respect to existing candidates.
Bragg gratings in carbon coated optical fibers and their potential sensor applications in harsh environment (2014)

We have demonstrated that fiber Bragg gratings can be written through the carbon layer of carbon-coated optical fibers having different coating thicknesses. Specifically, grating index modulation amplitudes of ~2.5x10<sup>-5</sup> and 0.52x10<sup>-5</sup> were obtained in optical fibers having carbon layers 29 nm and 56 nm thick, respectively, without any extra photosensitization of the fibers. Subsequent experimental results showed that the carbon coatings in the grating areas didn’t change their hermetic properties. Finally, we describe the advantages of these gratings and their potential applications in fiber optic sensing.
Cartilage-like Tissue Engineering Using Silk Scaffolds and Mesenchymal Stem Cells (2006)

Silk fibroin scaffolds were studied as a new biomaterial option for tissue-engineered cartilage-like tissue. Human bone marrow–derived mesenchymal stem cells (MSCs) were seeded on silk, collagen, and crosslinked collagen scaffolds and cultured for 21 days in serum-free chondrogenic medium. Cells proliferated more rapidly on the silk fibroin scaffolds than on the collagen matrices. The total content of glycosaminoglycan deposition was three times higher on silk as compared to collagen scaffolds. Glycosaminoglycan deposition coincided with overexpression of collagen type II and aggrecan genes. Cartilage-like tissue was homogeneously distributed throughout the entire silk scaffolds, while on the collagen and crosslinked collagen systems tissue formation was restricted to the outer rim, leaving a doughnut appearance. Round or angular-shaped cells resided in deep lacunae in the silk systems and stained positively for collagen type II. The aggregate modulus of the tissue-engineered cartilage constructs was more than 2-fold higher than that of the unseeded silk scaffold controls. These results suggest that silk fibroin scaffolds are suitable biomaterial substrates for autologous cartilage tissue engineering in serum-free medium and enable mechanical improvements along with compositional features suitable for durable implants to generate or regenerate cartilage.
Development of achromatic full-field hard x-ray microscopy with two monolithic imaging mirrors (2015)

Advanced Kirkpatrick-Baez mirror optics using two monolithic imaging mirrors was developed to realize an achromatic, high-resolution, and a high-stability full-field X-ray microscope. The mirror consists of an elliptical section and a hyperbolic section on a quartz glass substrate, in which the geometry follows the Wolter (type I) optics rules. A preliminary test was performed at SPring-8 using X-rays monochromatized to 9.881 keV. A 100-nm feature on a Siemens star chart could be clearly observed.
Surface-emitting, single-lobe operation from second-order distributed-reflector lasers with central grating phaseshift (2001)

Surface-emitting diode lasers containing a second-order Bragg grating with a central phaseshift, Δφ, of values around π are found to fundamentally favor lasing in a mode of symmetric near-field amplitude profile, which in turn provides emission in a single-lobed beam orthonormal to the surface. Devices of 500 μm long distributed-feedback (DFB) active region (λ=0.98 μm) and 500 μm long distributed feedback reflector passive regions provide, for Δφ=π, a surface-emitted beam pattern with 88% central-lobe power content, and external differential quantum efficiency, ηD, of 51%. Since the guided field is antisymmetric to start with, and a central π phaseshift causes two grating-outcoupled beams to be out-of-phase with each other, the net result is a single-lobed far-field pattern. The guided-field peak-to-valley (intensity) ratio, R, in the active (i.e., DFB) region is only 2, which insures single-mode operation to high powers, since the intermodal discrimination is high (⩾100 cm−1). Over a wide range in Δφ:60°; ηD remains high (&gt;50%) and the degree of guided-field uniformity remains low (R&lt;2).
Inhibition of RNA polymerase II transcription in human cells by synthetic DNA-binding ligands (HIV type 1yviral replicationyhairpin polyamideyDNA recognition) (1998)

Sequence-specific DNA-binding small mole- cules that can permeate human cells potentially could regulate transcription of specific genes. Multiple cellular DNA-binding transcription factors are required by HIV type 1 for RNA synthesis. Two pyrrole-imidazole polyamides were designed to bind DNA sequences immediately adjacent to binding sites for the transcription factors Ets-1, lymphoid-enhancer bind- ing factor 1, and TATA-box binding protein. These synthetic ligands specifically inhibit DNA-binding of each transcription factor and HIV type 1 transcription in cell-free assays. When used in combination, the polyamides inhibit virus replication by >99% in isolated human peripheral blood lymphocytes, with no detectable cell toxicity. The ability of small molecules to target predetermined DNA sequences located within RNA polymerase II promoters suggests a general approach for regulation of gene expression, as well as a mechanism for the inhibition of viral replication.
Development of Orally Bioavailable Bicyclic Pyrazolones as Inhibitors of Tumor Necrosis Factor-α Production (2004)

2-Aryl-3-pyrimidinyl based tumor necrosis factor-alpha (TNF-alpha) inhibitors, which contain a novel bicyclic pyrazolone core, are described. Many showed low-nanomolar activity against lipopolysaccharide-induced TNF-alpha production in monocytic cells. Secondary screening data are presented for the pyrimidinyl bicyclic pyrazolones. Several of these analogues showed good oral bioavailability in rat and efficacy in the rat iodoacetate in vivo model.
Quantification of cortisol in human eccrine sweat by liquid chromatography – tandem mass spectrometry (2016)

Cortisol has long been recognized as the "stress biomarker" in evaluating stress related disorders. Plasma, urine or saliva are the current source for cortisol analysis. The sampling of these biofluids is either invasive or has reliability problems that could lead to inaccurate results. Sweat has drawn increasing attention as a promising source for non-invasive stress analysis. A sensitive HPLC-MS/MS method was developed for the quantitation of cortisol ((11β)-11,17,21-trihydroxypregn-4-ene-3,20-dione) in human eccrine sweat. At least one unknown isomer that has previously not been reported and could potentially interfere with quantification was separated from cortisol with mixed mode RP HPLC. Detection of cortisol was carried out using atmospheric pressure chemical ionization (APCI) and selected reaction monitoring (SRM) in positive ion mode, using cortisol-9,11,12,12-D4 as internal standard. LOD and LOQ were estimated to be 0.04 ng ml(-1) and 0.1 ng ml(-1), respectively. Linear range of 0.10-25.00 ng ml(-1) was obtained. Intraday precision (2.5%-9.7%) and accuracy (0.5%-2.1%), interday precision (12.3%-18.7%) and accuracy (7.1%-15.1%) were achieved. This method has been successfully applied to the cortisol analysis of human eccrine sweat samples. This is the first demonstration that HPLC-MS/MS can be used for the sensitive and highly specific determination of cortisol in human eccrine sweat in the presence of at least one isomer that has similar hydrophobicity as cortisol. This study demonstrated that human eccrine sweat could be used as a promising source for non-invasive assessment of stress biomarkers such as cortisol and other steroid hormones.
Modeling Airflow Using Subject-Specific 4DCT-Based Deformable Volumetric Lung Models (2012)

Lung radiotherapy is greatly benefitted when the tumor motion caused by breathing can be modeled. The aim of this paper is to present the importance of using anisotropic and subject-specific tissue elasticity for simulating the airflow inside the lungs. A computational-fluid-dynamics (CFD) based approach is presented to simulate airflow inside a subject-specific deformable lung for modeling lung tumor motion and the motion of the surrounding tissues during radiotherapy. A flow-structure interaction technique is employed that simultaneously models airflow and lung deformation. The lung is modeled as a poroelastic medium with subject-specific anisotropic poroelastic properties on a geometry, which was reconstructed from four-dimensional computed tomography (4DCT) scan datasets of humans with lung cancer. The results include the 3D anisotropic lung deformation for known airflow pattern inside the lungs. The effects of anisotropy are also presented on both the spatiotemporal volumetric lung displacement and the regional lung hysteresis.
Neutron Transport and Nuclear Burnup Analysis for the Laser Inertial Confinement Fusion-Fission Energy (LIFE) Engine (2009)

Lawrence Livermore National Laboratory is currently developing a hybrid fusion-fission nuclear energy system, called LIFE, to generate power and burn nuclear waste. We utilize inertial confinement fusion to drive a subcritical fission blanket surrounding the fusion chamber. It is composed of TRISO-based fuel cooled by the molten salt flibe. Low-yield (37.5 MJ) targets and a repetition rate of 13.3 Hz produce a 500 MW fusion source that is coupled to the subcritical blanket, which provides an additional gain of 4-8, depending on the fuel.In the present work, we describe the neutron transport and nuclear burnup analysis. We utilize standard analysis tools including, the Monte Carlo N-Particle (MCNP) transport code, ORIGEN2 and Monte burns to perform the nuclear design. These analyses focus primarily on a fuel composed of depleted uranium not requiring chemical reprocessing or enrichment. However, other fuels such as weapons grade plutonium and highly-enriched uranium are also under consideration. In addition, we have developed a methodology using 6Li as a burnable poison to replace the tritium burned in the fusion targets and to maintain constant power over the lifetime of the engine. The results from depleted uranium analyses suggest up to 99% burnup of actinides is attainable while maintaining full power at 2GW for more than five decades.
Computationally-Efficient DSP-based MIMO Equalization for OSNR gains in 40Gb/s OFDMA-PON (2011)

We present and experimentally verify a novel computationally-efficient MIMO equalization method in 40Gb/s OFDMA-PON with polarization multiplexing and direct detection. A 2.1dB DSP-based OSNR gain is achieved over 20km SSMF plus 1:32 optical split.
Ultralow reflectance metal surfaces by ultrafast laser texturing (2010)

We report the fabrication of textured metal surfaces by ultrafast laser processing and its optical property characterization by measurement of reflection and scattering as a function of angle and wavelength. The ultrafast laser textured metal surface reflection combined with scattering can be reduced to low values of ∼3% over a broad spectral and angular range. Furthermore, it is shown that surface optical reflection and scattering can be varied by parameters like laser fluence, number of laser pulses, and coating the textured surfaces with suitable absorbers. It is also shown that ultrafast laser textured metal surfaces can have low surface reflection and scattering properties even at high temperatures (≤500 °C) of operation.
Identification of novel cluster groups in pediatric high-risk B-precursor acute lymphoblastic leukemia with gene expression profiling: correlation with genome-wide DNA copy number alterations, clinical characteristics, and outcome (2010)

To resolve the genetic heterogeneity within pediatric high-risk B-precursor acute lymphoblastic leukemia (ALL), a clinically defined poor-risk group with few known recurring cytogenetic abnormalities, we performed gene expression profiling in a cohort of 207 uniformly treated children with high-risk ALL. Expression profiles were correlated with genome-wide DNA copy number abnormalities and clinical and outcome features. Unsupervised clustering of gene expression profiling data revealed 8 unique cluster groups within these high-risk ALL patients, 2 of which were associated with known chromosomal translocations (t(1;19)(TCF3-PBX1) or MLL), and 6 of which lacked any previously known cytogenetic lesion. One unique cluster was characterized by high expression of distinct outlier genes AGAP1, CCNJ, CHST2/7, CLEC12A/B, and PTPRM; ERG DNA deletions; and 4-year relapse-free survival of 94.7% ± 5.1%, compared with 63.5% ± 3.7% for the cohort (P = .01). A second cluster, characterized by high expression of BMPR1B, CRLF2, GPR110, and MUC4; frequent deletion of EBF1, IKZF1, RAG1-2, and IL3RA-CSF2RA; JAK mutations and CRLF2 rearrangements (P < .0001); and Hispanic ethnicity (P < .001) had a very poor 4-year relapse-free survival (21.0% ± 9.5%; P < .001). These studies reveal striking clinical and genetic heterogeneity in high-risk ALL and point to novel genes that may serve as new targets for diagnosis, risk classification, and therapy.
A multipoint scanner for high frame rate confocal microendoscopy (2010)

Slit-scanning geometries for confocal microendoscopy represent a compromise between acquisition rate and optical performance. Such systems provide high frame rates that freeze motion but recent Monte Carlo simulations show that scattered light severely limits the practical imaging depth for <i>in vivo</i> applications. A new multi-point scanning architecture for confocal microendoscopy has been developed. The new scanner is based on a relatively simple modification to the slit-scanning geometry that results in a parallelized point-scanning confocal microendoscope that maintains the high frame rate of a slit-scanning system while providing optical performance close to that of a single point scanning system. The multi-point scanner has been incorporated into an existing multi-spectral slit-scanning confocal microendoscope. The new confocal aperture consists of a slit and a rotating low duty cycle binary transmission grating, which effectively produces a set of continuously moving widely spaced illumination points along the slit. The design maintains the ability to rapidly switch between grayscale and multi-spectral imaging modes. The improved axial resolution of the multi-point scanning confocal microendoscope leads to significantly better confocal sectioning and deeper imaging, which greatly improves the diagnostic potential of the instrument.
Efficiency enhancement of an organic light-emitting diode with a cathode forming two-dimensional periodic hole array (2005)

We fabricated an organic light-emitting diode using a π-conjugated polymer emissive layer sandwiched between two semitransparent electrodes: an optically thin gold film anode, whereas the cathode was in the form of an optically thick aluminum (Al) film with patterned periodic subwavelength two-dimensional hole array that showed anomalous transmission in the spectral range of the polymer photoluminescence band. At similar current densities, we obtained a sevenfold electroluminescence efficiency enhancement with the patterned Al device compared with a control device based on unperforated Al electrode.
A systems approach to photovoltaic energy extraction (2012)

Per-panel photovoltaic energy extraction with integrated converters can increase overall array tracking efficiency. Also, switched-capacitor (SC) converters have been evaluated for many applications because of the possibility for on-chip integration; applications to solar arrays are no exception. This paper presents a comprehensive system-level look at solar installations, finding possibilities for optimization at and between all levels of operation in an array. Specifically, this paper examines new arrangements and options for applying switched-capacitor circuits at 3 levels: for the panel and sub-panel level, as part of the overall control strategy, and for ensuring stable and robust interface to the grid with the possibility of eliminating or reducing the use of electrolytic capacitors.
Post-acquisition ETD spectral processing for increased peptide identifications (2009)

Tandem mass spectra (MS/MS) produced using electron transfer dissociation (ETD) differ from those derived from collision-activated dissociation (CAD) in several important ways. Foremost, the predominant fragment ion series are different: c- and z(*)-type ions are favored in ETD spectra while b- and y-type ions comprise the bulk of the fragments in CAD spectra. Additionally, ETD spectra possess charge-reduced precursors and unique neutral losses. Most database search algorithms were designed to analyze CAD spectra, and have only recently been adapted to accommodate c- and z(*)-type ions; therefore, inclusion of these additional spectral features can hinder identification, leading to lower confidence scores and decreased sensitivity. Because of this, it is important to pre-process spectral data before submission to a database search to remove those features that cause complications. Here, we demonstrate the effects of removing these features on the number of unique peptide identifications at a 1% false discovery rate (FDR) using the open mass spectrometry search algorithm (OMSSA). When analyzing two biologic replicates of a yeast protein extract in three total analyses, the number of unique identifications with a approximately 1% FDR increased from 4611 to 5931 upon spectral pre-processing--an increase of approximately 28.6%. We outline the most effective pre-processing methods, and provide free software containing these algorithms.
Ranging and Synchronization between Nominally Co-Orbital Satellites (1981)

Abstract : A link between two satellites can provide direct measurements of clock synchronism and intersatellite range that are more accurate than estimates obtainable from ground measurements. Moreover these direct measurements can be made continuously with near-zero delays. Two approaches to ranging and synchronization between satellite pairs are 'balanced' systems in which each satellite makes a time-difference measurement, and 'full loop' systems in which a time-difference measurement is made on only one satellite. This report discusses factors which determine the ultimate limitations and capabilities of both approaches, and compares the schemes for applications in which two digital clocks are actually brought into synchronism with accuracies of several nanoseconds. (Author)
Improved external coupling efficiency in organic light-emitting devices on high-index substrates (2002)

High-index-of-refraction substrates are shown theoretically and experimentally to increase the external coupling efficiency of organic light-emitting devices (OLEDs) by using a quantum mechanical microcavity model. This increase is due to the elimination of those modes waveguided in the ITO/organic layer. Bi-layer OLEDs were fabricated on standard soda lime glass and high-index glass substrates, and their far-field intensity pattern was measured. Among the devices optimized for external efficiency, those on shaped high-index substrates exhibited a 53% improvement in external quantum efficiency over the devices on shaped standard glass substrates, and an increase by a factor of 2-3 times over those on planar glass substrates. This principle is applicable to any backside patterning technique in conjunction with other OLED structural improvements.
Demonstration of Single-End Adaptive Optics Compensation for Emulated Turbulence in a Bi-directional 10-Mbits/s per Channel Free-Space Quantum Communication Link Using Orbital-Angular-Momentum Encoding (2018)

We experimentally demonstrate simultaneous pre-and-post adaptive-optics compensation for an OAM-encoded, bi-directional quantum communication link. The atmospheric turbulence-induced quantum-symbol-error-rates are improved by ~74.0 % and ~74.1 % in forward and backward channels using the compensation method.
Active negative refraction index (NRI) transmission line with gain (2012)

We have investigated microwave active negative refractive index (NRI) transmission line (also named composite right-hand / left-hand transmission line, or CRLH-TL) metamaterials incorporating gain devices to provide effective negative resistance. Our simulation and experimental results show that by inserting semiconductor tunnel diode at the unit cell level, the negative phase constant (i.e., left-handedness) of this kind of transmission lines is maintained while gain can be obtained (negative attenuation constant of transmission line) simultaneously. Important design aspects of the active metamaterial transmission lines are discussed. As a potential application, single unit-cell zeroth order resonator (ZOR) antennas based on the passive and active transmission lines are also discussed.
Analysis of Dynamic Fracture Behaviour Using 4D Seismic Data (2009)

This paper presents a new methodology for analysing dynamic behaviour of fractures or fracture systems from time lapse seismic data. It is previously demonstrated how a static fracture pattern can be analysed using discontinuity enhancing seismic attribut