gebhart/patrepeval huggingface dataset:
86% internal differential efficiency from 8 to 9 µm-emitting, step-taper active-region quantum cascade lasers (2016)

8.4 μm-emitting quantum cascade lasers (QCLs) have been designed to have, right from threshold, both carrier-leakage suppression and miniband-like carrier extraction. The slope-efficiency characteristic temperature T<sub>1</sub>, the signature of carrier-leakage suppression, is found to be 665 K. Resonant-tunneling carrier extraction from both the lower laser level (ll) and the level below it, coupled with highly effective ll-depopulation provide a very short ll lifetime (~0.12 ps). As a result the laser-transition differential efficiency reaches 89%, and the internal differential efficiency η<sub>id</sub>, derived from a variable mirror-loss study, is found to be 86%, in good agreement with theory. A study of 8.8 μm-emitting QCLs also provides an η<sub>id</sub> value of 86%. A corrected equation for the external differential efficiency is derived which leads to a fundamental limit of ~90% for the η<sub>id</sub> values of mid-infrared QCLs. In turn, the fundamental wallplug-efficiency limits become ~34% higher than previously predicted.
An effect of time-of-flight (TOF) information on normalization components and point spread function (PSF) in positron emission tomography (PET) (2014)

Before the image reconstruction process takes place, emission data from a PET scanner must be corrected for scatter and changes for detector sensitivity. Normalization process should take care of the variations in the detector sensitivity. Because of the need of high statistics for large number of line-of-responses (LORs), component-based normalization method was implemented in the state-of-the-art PET scanners. Since the development of TOF PET scanners, normalization components were never revisited to examine the effect of the TOF dependency. The purpose of this work was to understand the TOF dependency on normalization. Experiments and Monte Carlo simulations were acquired to examine the TOF effect on normalization. In this process, point spread function was also investigated to understand the TOF dependency through the depth of the LOR. PSF responses at four locations have been estimated through Monte Carlo simulations along two LORs at two positions each. Preliminary PSF measurements were also performed by using a PET scanner for comparison.
Combined Probabilistic Shaping and Nyquist Pulse Shaping for PAM8 Signal Transmission in WDM Systems (2019)

We use the LDPC-coded probabilistically shaped PAM8 signaling combined with Nyquist pulse shaping to improve the transmission performance in a WDM system. We find that the combination of these shaping schemes offers great performance improvement. (C) 2019 The Author(s)
A 2-D imaging heat-flux gauge (1991)

This report describes a new leadless two-dimensional imaging optical heat-flux gauge. The gauge is made by depositing arrays of thermorgraphic-phosphor (TP) spots onto the faces of a polymethylpentene is insulator. In the first section of the report, we describe several gauge configurations and their prototype realizations. A satisfactory configuration is an array of right triangles on each face that overlay to form squares when the gauge is viewed normal to the surface. The next section of the report treats the thermal conductivity of TPs. We set up an experiment using a comparative longitudinal heat-flow apparatus to measure the previously unknown thermal conductivity of these materials. The thermal conductivity of one TP, Y{sub 2}O{sub 3}:Eu, is 0.0137 W/cm{center dot}K over the temperature range from about 300 to 360 K. The theories underlying the time response of TP gauges and the imaging characteristics are discussed in the next section. Then we discuss several laboratory experiments to (1) demonstrate that the TP heat-flux gauge can be used in imaging applications; (2) obtain a quantum yield that enumerates what typical optical output signal amplitudes can be obtained from TP heat-flux gauges; and (3) determine whether LANL-designed intensified video cameras have sufficient sensitivity to acquire images from the heat-flux gauges. We obtained positive results from all the measurements. Throughout the text, we note limitations, areas where improvements are needed, and where further research is necessary. 12 refs., 25 figs., 4 tabs.
Online Analysis of Community Evolution in Data Streams (2005)

This paper discusses the problem of online change detection in a large set of interacting entities. Such trends include the gradual formation and dissolution of different communities of interaction. Our results are focussed on the case where the interacting entities are received in the form of a fast data stream of interactions. In such cases, a user may wish to perform repeated exploratory querying of the data for different kinds of user-defined parameters. This is difficult to perform in a fast data stream because of the one-pass constraints on the computations. We propose an online analytical processing framework which separates out online data summarization from offline exploratory querying. The result is a method which provides the ability to perform exploratory querying without compromising on the quality of the results. The algorithms are tested over large sets of graph data streams with varying levels of evolution.
Loki (2019)

Remotely instructing and guiding users in physical tasks has offered promise across a wide variety of domains. While it has been the subject of many research projects, current approaches are often limited in the communication bandwidth (lacking context, spatial information) or interactivity (unidirectional, asynchronous) between the expert and the learner. Systems that use Mixed-Reality systems for this purpose have rigid configurations for the expert and the learner. We explore the design space of bi-directional mixed-reality telepresence systems for teaching physical tasks, and present Loki, a novel system which explores the various dimensions of this space. Loki leverages video, audio and spatial capture along with mixed-reality presentation methods to allow users to explore and annotate the local and remote environments, and record and review their own performance as well as their peer's. The system design of Loki also enables easy transitions between different configurations within the explored design space. We validate its utility through a varied set of scenarios and a qualitative user study.
Silicone pressure-sensitive adhesives with selective adhesion characteristics (1996)

Abstract The peel, probe tack, and loop tack adhesion characteristics of peroxide-cured silicone pressure-sensitive adhesives (PSAs) are investigated with respect to adhesive composition, peroxide concentration, and type of substrate. These adhesion properties decrease with increasing benzoyl peroxide concentration and their adhesion values vary noticeably with the substrate type. However, the loop adhesion to 'difficult-to-wet' surfaces (e.g. silicone-coated substrates) can be selectively enhanced by incorporating an organofunctional silicone into the silicone PSA mixture. The enhancement in adhesion is attributed to a wetting/adhesion improvement at the adhesive- substrate interface, and relates to the type of organosilicone modifier in the order aminosilicone > vinylsilicone > epoxysilicone > fluorosilicone. Keywords: Siliconespressure-sensitive adhesiveswetting capabilitysilicone modifiertack adhesionpeel strength
Monitoring brain development with quantitative diffusion tensor imaging (2002)

Abstract Quantifying changes that occur during brain maturation may help in diagnosing diseases that affect pediatric patients. By obtaining normative curves that define brain maturation, pathological changes may be easier to recognize. We assessed diffusion changes which are inherently related to the brain structure during maturation and obtained normative curves. MR scans were obtained for 26 pediatric subjects (ages 0 to 11 years) and four adults. The MR images were all normal. Maps of the average diffusion constant (D av ) were calculated for each subject. Changes in D av were determined with distribution analysis for the entire brain and compared with regions of interest measurements from the periventricular white matter and thalamus. The mean diffusion constant of the whole brain changes quite rapidly as the brain matures. The data suggest that at least two distinct processes are responsible for the change. Quantitative diffusion tensor imaging may provide means of quantifying overall human brain maturation that may be useful in diagnosing pathology.
Piezoelectricity in nylon 11 (1980)

At the present time, only poled, drawn poly (vinylidene fluoride) (PVF2) films give evidence of sufficiently high piezoelectric response to be useful in device applications, and for this reason the great majority of research has centered around this polymer. As in the case of PVF2, many odd nylons crystallize in a polar space group with a large net dipole moment in the unit cell. On the basis of the understanding now reached of the properties of poled PVF2 films, it would appear that the odd nylons have the potential to make films with high piezoelectric activity. Piezoelectricity and pyroelectricity in nylon 11 films have been studied previously. The piezoelectric strain constants found were larger than most polymers, but still two orders of magnitude less than the corresponding activity found in poled oriented PVF2 (d31∼20 pC/N). Studies carried out in this laboratory have shown that by appropriate variation of poling conditions and sample microstructure, relatively large piezoelectric constants can be obtained for nylon 11 films (d31∼3 pC/N). The dependence of the piezoelectric strain constant d31 on poling temperature, poling field, and crystal structure will be discussed.
Low-Loss Diamond Surface Acoustic Wave Devices Using Small-Grain Poly-Crystalline Diamond (2002)

We have developed a poly-crystalline diamond film whose grain size is about 0.5 µm, which is smaller than that of our previously studied diamond films applied in surface acoustic wave (SAW) devices. Using the small-grain diamond, three kinds of narrow-band SAW filters were fabricated with the SiO2/interdigital-transducer (IDT)/ZnO/diamond/Si structure at the center frequencies from 2.488 to 5.0 GHz. The insertion losses of these filters were lower by 1.3 to 3.2 dB and the Q values were 200 higher than those obtained using the standard diamond. The Q value is defined as the center frequency divided by the bandwidth at a loss level 3 dB lower than the minimum insertion loss. "Standard diamond" refers to our previously studied diamond. The propagation loss, electro-mechanical coupling coefficient (K2), phase velocity and temperature coefficient of frequency (TCF) were investigated on the basis of the measured characteristics of these filters. It was found that the propagation loss was about two thirds of that obtained using the standard diamond film while TCF, K2 and phase velocity were almost the same as those obtained using the standard diamond.
Targeting Bacterial Topoisomerases: How to Counter Mechanisms of Resistance (2016)

DNA gyrase and topoisomerase IV are type IIA bacterial topoisomerases that are targeted by highly effective antibiotics. However, resistance via multiple mechanisms arises to limit the efficacies of these drugs. Continued research on type IIA bacterial topoisomerases has provided novel approaches to counter the most common resistance mechanism for utilization of these proven targets in antibacterial therapy. Bacterial topoisomerase I is being explored as an alternative target that is not expected to show cross-resistance. Dual targeting or combination therapy could be strategies for circumventing the development of resistance to topoisomerase-targeting antibiotics. Bacterial topoisomerases are high-value bactericidal targets that could continue to be exploited for antibacterial therapy, if new tactics to counter resistance can be adopted.
Iridium Photocatalysts in Free Radical Photopolymerization under Visible Lights (2012)

A series of iridium(III) complexes was designed and investigated as new potential photocatalysts for radical polymerization reactions. The photocatalytic reduction cycle involves the combination of an iridium complex with an amine (e.g., <i>N</i>-methyldiethanolamine) and an alkyl halide (e.g., phenacylbromide). The different three-component systems herein investigated are very attractive for acrylate polymerization upon visible light irradiation. They are much more reactive than those based on Ru(bpy)<sub>3</sub><sup>2+</sup>. Free radicals generated during the reaction were investigated by ESR spectroscopy and the chemical mechanisms are discussed. The crucial role played by the photocatalyst (reduction ability and excited state lifetime) is also demonstrated.
Designing Syngas Fermentation Medium for Fuels and Bulk Chemicals Production (2011)

Fermentation medium was designed for production of ethanol and acetic acid from synthesis gas by Clostridium ragsdalei, also called Clostridium strain P11, which reduced the production cost by 95% compared to the standard medium. The medium was developed by serial deletion of components from the standard medium used for isolation and growth of the bacterium. Cost and purpose of individual components in the designed medium were considered to guide the revision of the medium recipe. This process resulted in the elimination of Morpholinoethanesulfonic acid (MES), a buffer used to maintain the pH near 6.0. Instead, a buffer was formed from the acetic acid produced during the fermentation and addition of bicarbonate, keeping the pH around 4.75 to enhance ethanol production. The performance of fermentation without MES, with pH control using acetate buffer was similar to that from the original rich medium. Additionally, yeast extract, an undefined growth promoter, was eliminated and trace metals for medium preparation were prepared in dilute solution without chelating agents. Fermentation without yeast extract resulted in lower growth, but comparable initial substrate uptake and production rates. Further, omission of cysteine from the medium and dependence on sulfide as nutrient sulfur source enhanced ethanol production, but did not sustain growth of strain P11. The control of pH in the designed medium and selection of appropriate sources of elemental nutrients is expected to enhance fermentation performance and further decrease cost.
A Switchable Site-Specific Antibody Conjugate (2018)

Genetic incorporation of unnatural amino acids (UAAs) provides a unique approach to the synthesis of site-specific antibody conjugates that are homogeneous and better defined constructs than random conjugates. Yet, the yield varies for every antibody, and the process is costly and time-consuming. We have developed a switchable αGCN4-Fab conjugate that incorporates UAA p-acetylphenylalanine. The GCN4 peptide is used as a switch, and antibodies fused by GCN4 can direct the αGCN4-Fab conjugate to target different cancer cells for diagnosis, imaging, or therapeutic treatment. More importantly, this switchable conjugate demonstrated an impressive potential for pretargeted imaging in vivo. This approach illustrates the utility of an orthogonal switch as a general strategy to endow versatility to a single antibody conjugate, which should facilitate the application of UAA-based site-specific conjugates for a host of biomedical uses in the future.
Blockade of Intravascular Hemolysis in PNH with the Terminal Complement Inhibitor Eculizumab Unmasks Low-Level Hemolysis Potentially Occurring through C3 Opsonization. (2006)

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia characterized by intravascular hemolysis, often resulting in the need for red blood cell (RBC) transfusions. PNH RBCs lack two complement regulatory molecules - CD59, a terminal complement inhibitor, and CD55, a C3 convertase inhibitor. Eculizumab, a humanized monoclonal antibody that inhibits terminal complement by binding to C5, effectively controls intravascular hemolysis as determined by a dramatic reduction in lactate dehydrogenase (LDH) to levels in or just above the normal range. Control of intravascular hemolysis in these patients led to a reduction in, or cessation of, RBC transfusions. During eculizumab treatment, a majority of patients demonstrate evidence of residual, low-level hemolysis; LDH levels remain slightly elevated, haptoglobin levels are low or undetectable, and bilirubin levels are above normal. We hypothesized that this low-level residual hemolysis may be due to clearance of PNH RBCs through a C3b-mediated mechanism. Therefore we investigated C3 deposition on RBC in PNH patients before and on eculizumab. A direct antiglobulin test (DAT) using monoclonal anti-C3d was positive in 29 out of 39 PNH patients on eculizumab. Of these 29 DAT-positive patients, who were all receiving transfusions, 25 had DAT testing prior to eculizumab therapy and only one of these was positive. DAT was negative in all of 8 normal volunteers. By two-color flow cytometric analysis with anti-CD59 and anti-C3, the majority of patients on eculizumab demonstrated three distinct RBC populations: CD59+/C3− (normal RBCs); CD59-/C3− (PNH RBCs without C3 coating); and CD59-/C3+ (PNH RBCs coated by C3). No CD59+/C3+ RBCs were observed. Of 21 DAT positive eculizumab treated patients tested, the median proportion of total RBCs that were C3b positive was 17.6%. 18 of 29 [62%] eculizumab patients with a positive DAT received at least one transfusion during eculizumab therapy compared with 1 of 10 [10%] for DAT negative patients (p=0.01), although even patients who did not become transfusion independent during eculizumab treatment showed a marked reduction in transfusion requirement. The median hemoglobin value for the 29 DAT positive eculizumab patients was 9.8 g/dL compared with 11.3 g/dL in the 10 DAT negative eculizumab patients (p= 0.08). No apparent relationship between LDH and DAT positivity was observed. It is proposed that resolution of intravascular hemolysis in PNH patients on eculizumab results in deposition of C3b on the surface of PNH RBCs which may explain, at least in part, the residual low level hemolysis occurring in some patients. This appears to be a previously undescribed mechanism of RBC clearance in PNH, most likely obscured by the rapidity of intravascular hemolysis in the absence of eculizumab therapy. Despite the low-level residual hemolysis, patients continue to receive significant benefit from eculizumab treatment.
Data from Antibody Blockade of Semaphorin 4D Promotes Immune Infiltration into Tumor and Enhances Response to Other Immunomodulatory Therapies (2023)

<div>Abstract<p>Semaphorin 4D (SEMA4D, CD100) and its receptor plexin-B1 (PLXNB1) are broadly expressed in murine and human tumors, and their expression has been shown to correlate with invasive disease in several human tumors. SEMA4D normally functions to regulate the motility and differentiation of multiple cell types, including those of the immune, vascular, and nervous systems. In the setting of cancer, SEMA4D–PLXNB1 interactions have been reported to affect vascular stabilization and transactivation of ERBB2, but effects on immune-cell trafficking in the tumor microenvironment (TME) have not been investigated. We describe a novel immunomodulatory function of SEMA4D, whereby strong expression of SEMA4D at the invasive margins of actively growing tumors influences the infiltration and distribution of leukocytes in the TME. Antibody neutralization of SEMA4D disrupts this gradient of expression, enhances recruitment of activated monocytes and lymphocytes into the tumor, and shifts the balance of cells and cytokines toward a proinflammatory and antitumor milieu within the TME. This orchestrated change in the tumor architecture was associated with durable tumor rejection in murine Colon26 and ERBB2<sup>+</sup> mammary carcinoma models. The immunomodulatory activity of anti-SEMA4D antibody can be enhanced by combination with other immunotherapies, including immune checkpoint inhibition and chemotherapy. Strikingly, the combination of anti-SEMA4D antibody with antibody to CTLA-4 acts synergistically to promote complete tumor rejection and survival. Inhibition of SEMA4D represents a novel mechanism and therapeutic strategy to promote functional immune infiltration into the TME and inhibit tumor progression. <i>Cancer Immunol Res; 3(6); 689–701. ©2015 AACR</i>.</p></div>
A low-loss 1.8GHz monolithic thin-film piezoelectric-on-substrate filter (2008)

A 1.8GHz thin-film piezoelectric-on-substrate (TPoS) filter with insertion loss of less than 4dB and bandwidth of 18MHz (50Ω termination) is presented in this paper. Such filters are alternatives to conventional ladder-type filters working in the frequency range of up to a few GHz. A monolithic TPoS filter is a coupled mode system based on a single composite resonant structure, with a thin piezoelectric layer deposited on a high acoustic velocity, low loss substrate layer. An interdigitated top electrode structure is used that eliminates the spurious modes and provides a mechanism for adjusting the bandwidth.
Role of N2 addition on CF4/O2 remote plasma chemical dry etching of polycrystalline silicon (1997)

The remote plasma chemical dry etching of polycrystalline silicon was investigated using various CF4/O2/N2 gas compositions. The effects of O2 and N2 addition on the etch rate and surface chemistry were established. Admixing O2 to CF4 increases the gas phase fluorine density and increases the etch rate by roughly sevenfold to a maximum at an O2/CF4 ratio of 0.15. The addition of small amounts of N2 (N2/CF4=0.05) can again double this etch rate maximum. Strong changes in surface chemistry were also seen as a result of N2 addition to CF4/O2. Real-time ellipsometry and atomic force micro-roughness measurements reveal that nitrogen addition at low O2/CF4 ratios leads to the smoothing of surfaces, but to increased oxidation at high O2/CF4 ratios. Based on etch rate data and gas phase species analysis, we propose that NO plays an important role in the overall etching reaction. Variable tube lengths separated the reaction chamber from the discharge. These tubes were lined with either quartz or Teflon liners. In general, etch rates diminished with quartz tube length. At the longer transport tube lengths (e.g., 125 cm), using a Teflon lining material strongly increases the etch rate for pure CF4/O2 discharges as compared to the quartz. For discharges containing N2, the etch rate is more than doubled. This can be explained by the low recombination rate of atomic fluorine on Teflon and the subsequent high density of F atoms that reach the process chamber, even for long transport tube lengths. In situ ellipsometric measurements reveal postplasma surface modifications for certain etching chemistries. Comparisons of these results to x-ray photoemission measurements reveal a dependence of the stability of the postprocessing surface reaction layer on the etching conditions and hence the thickness and composition of the layer, i.e., whether the layer is comprised of volatile (SiFx-like) or involatile (SiOy-like) species. Thicker, more SiOy-like reaction layers create a barrier for the diffusion and subsequent desorption of the volatile products and a postplasma removal of a portion of the reaction layer is observed. Thinner, more SiFx-like layers leave a fluorine deficient surface in the postplasma stage which results in increased tendency to postplasma layer growth. The etching of silicon is not always limited by the arrival rate of atomic fluorine for our processing conditions.