gebhart/patrepeval huggingface dataset:
Copper(II) Complexes of Novel N-Alkylated Derivatives of <i>cis,cis</i>-1,3,5-Triaminocyclohexane. 1. Preparation and Structure (2001)

Novel N,N',N' '-trialkylated derivatives of cis,cis-1,3,5-triaminocyclohexane (tach), designated tach-R(3), were prepared through alkylation of N-protected tach with subsequent acid deprotection, to afford N-methyl, N-ethyl, and N-n-propyl derivatives as their trihydrobromide salts. The tach-neopentyl(3) and tach-furan(3) derivatives were prepared by formation of the imine from tach and pivaldehyde or furan-2-carboxaldehyde, respectively, followed by reduction of the imine. Complexes [Cu(tach-R(3))Cl(2)] (R = Me, Et, n-Pr, CH(2)-2-thienyl, and CH(2)-2-furanyl) were prepared from CuCl(2) in MeOH or MeOH-Et(2)O solvent. Crystallographic characterization of [Cu(tach-Et(3))Br(0.8)Cl(1.2)] (Pnma, a = 8.2265(1) A, b = 12.5313(1) A, c = 15.3587(3) A, Z = 4) reveals a square-based pyramidal CuN(3)X(2) coordination sphere in which one nitrogen donor occupies the apical position at a slightly longer distance (Cu-N = 2.218(5) A) than those of the basal nitrogens (Cu-N = 2.053(2) A). The solution-phase (pH 7.4 buffered and methanol) and solid-phase structures of [Cu(tach-R(3))Cl(2)] have been studied extensively by EPR and visible-near-IR spectroscopies. The square-based pyramidal structure is retained in solution, according to correspondence of solution and solid-state data. In aqueous solution, halide is replaced by water, as indicated by the high-energy UV-vis spectral shifts and bonding parameters of [Cu(tach-Et(3))](2+)(aq) derived from EPR data. The proposed aqueous-phase species, in the pH range 7.4 to 10.1, is [Cu(tach-Et(3))(H(2)O)(2)](2+). The complex [Cu(tach-Me(3))](2+)(aq) does not appear to dimerize or form metal-hydroxo species at pH 7.4, in contrast to other Cu(II)-triamine complexes, e.g., [Cu(1,4,7-triazacyclononane)](2+) (aq) and [Cu(tach-H(3))](2+)(aq) (the complex of unalkylated tach). This difference is attributed to the steric effect of the N-alkyl groups in the tach-R(3) series.
A study of broadband sensor location selection using convex optimization in very large scale arrays (2014)

Consider a sensing system using a large number of N microphones, placed in multiple dimensions to monitor a broadband acoustic field. Using all the microphones at once is impractical because of the amount of data generated. Instead, we choose a subset of D microphones to be active. Specifically, we wish to find the set of D microphones which minimizes the energy of the interference gains at multiple frequencies while monitoring a target of interest. A direct, combinatorial approach—testing all N choose D subsets of microphones is impractical because of problem size. Instead, we use a convex optimization technique that induces sparsity through a l1-penalty to determine which subset of microphones to use. We measure the energy of the interference gains in three ways: the maximum gain, the average gain, and the average squared gain and compare the results. Furthermore, we assume one reflection off of each wall in our problem setup and minimize the gains of the reflections. We test the robustness of the our solution through simulated annealing and compare its performance against a classical beamformer which maximizes SNR. We also do exhaustive searches to compare the performance of our algorithm against the global optimum.
Research to conduct an exploratory experimental and analytical investigation of alloys. Interim technical report, May 1977-December 1978 (1981)

Materials based on the intermetallic phases Ti/sub 3/Al (alpha 2) and TiAl (gamma) exhibit several attractive features that make them candidates for gas-turbine-engine applications. Low density, good oxidation resistance and high-temperature strength are such characteristics and could result in substitution for the nickel alloys currently used for components that operate at intermediate temperatures. The overall objectives of this portion of the program are to identify Ti/sub 3/Al alloys with properties compatible with gas-turbine applications and to develop preliminary processing and finishing techniques that are needed to make prototype hardware. The Ti-Al-Nb system has been shown to be the best system for alloy development. In this study, higher aluminum contents, at a constant niobium level, have been shown to improve stress-rupture properties at the expense of ductility at low and intermediate temperatures. Additions of zirconium, tin, hafnium or carbon to a Ti-Al-Nb base do not produce improved mechanical properties. Substitution of vanadium for some of the niobium in Ti-25Al-11Nb appears useful in reducing cost and density of the alloys. Lower oxygen content was shown to be one of the most effective means to improve-room temperature ductility.
Functional monovalency amplifies the pathogenicity of anti-MuSK IgG4 in myasthenia gravis (2020)

Abstract Human IgG4 usually displays anti-inflammatory activity, and observations of IgG4 autoantibodies causing severe autoimmune disorders are therefore poorly understood. In blood, IgG4 antibodies naturally engage in a stochastic process termed Fab-arm exchange in which unrelated IgG4s exchange half-molecules continuously. The resulting IgG4 antibodies are composed of two different binding sites, thereby acquiring monovalent binding and inability to cross-link for each antigen recognized. Here, we demonstrate this process amplifies autoantibody pathogenicity in a classic IgG4-mediated autoimmune disease: muscle-specific kinase (MuSK) myasthenia gravis (MG). In mice, monovalent anti-MuSK IgG4s caused rapid and severe myasthenic muscle weakness, whereas the same antibodies in their parental bivalent form were less potent or did not induce a phenotype. Mechanistically this could be explained by opposing effects on MuSK signaling. Isotype switching to IgG4 in an autoimmune response thereby may be a critical step in the development of disease. Our study establishes functional monovalency as a novel pathogenic mechanism in IgG4-mediated autoimmune disease and potentially other disorders. Graphical abstract
EntityTagger (2011)

We consider the problem of entity tagging: given one or more named entities from a specific domain, the goal is to automatically associate descriptive phrases, referred to as etags (entity tags), to each entity. Consider a product catalog containing product names and possibly short descriptions. For a product in the catalog, say Ricoh G600 Digital Camera, we want to associate etags such as "water resistant", "rugged" and "outdoor" to it, even though its name or description does not mention those phrases. Entity tagging can enable more effective search over entities. We propose to leverage signals in web documents to perform such tagging. We develop techniques to perform such tagging in a domain independent manner while ensuring high precision and high recall.
Toward a Contactless Hydrokinetic Energy Harvester: A Computational Magnetic Field Estimation (2018)

Magnetic levitation (maglev) concepts are applied to a variety of industries such as the automotive, aerospace, or energy in order to accomplish different tasks: suspension and propulsion in maglev trains, rocket propulsion and spacecraft attitude control, centrifuge of nuclear reactors. In this paper, maglev is implemented in environmentally friendly hydrokinetic energy harvesting to achieve contactless bearing, thus, minimizing friction and improving efficiency. Generally, maglev systems exhibit higher efficiency and reduced maintenance while providing longer lifetime and higher durability when appropriate engineering design and control are applied. A Flow Induced Oscillation (FIO) energy-harvesting converter is considered in this work. To minimize friction in the support of the cylinder in FIO (vortex induced vibrations and galloping) due to high hydrodynamic drag, a maglev system is proposed. In the proposed configuration, a ferromagnetic core (element 1), of known dimensions, is considered under the effects of an externally imposed magnetic field. A second ferromagnetic element, of smaller dimensions, is then placed adjacent to the previous considered core. This particular configuration results in a non-homogenous magnetic field for element 1, caused by dimensional disparity. Specifically, the magnetic flux does not follow a linear path from the ferromagnetic core to element 2. A general electromagnetic analysis is conducted to derive an analytical form for the magnetic field of element 1. Subsequent numerical simulation validates the obtained formula. This distinct expression for the magnetic field is valuable towards calculating the magnetic energy of this specific configuration, which is essential to the design of the FIO energy harvesting converter considered in this work.
Airflow system identification analysis for optimizing commercial building VAV settings for improved energy efficiency (2015)

The paper presents a system identification method that can determine individual room air change rates in commercial building HVAC systems. This is achieved by utilizing a combined low order model based on the room's thermal dynamics and experimental approach. The low order model is shown to capture the dominant dynamics of the room air temperature response. This method can help enable significant building energy use reduction by reassessing the air flow rates needed for each room in a building.
Optimal illumination scheme for isotropic quantitative differential phase contrast microscopy (2019)

Differential phase contrast microscopy (DPC) provides high-resolution quantitative phase distribution of thin transparent samples under multi-axis asymmetric illuminations. Typically, illumination in DPC microscopic systems is designed with 2-axis half-circle amplitude\npatterns, which, however, result in a non-isotropic phase contrast transfer function (PTF). Efforts have been made to achieve isotropic DPC by replacing the conventional half-circle illumination aperture with radially asymmetric patterns with 3-axis illumination or gradient amplitude\npatterns with 2-axis illumination. Nevertheless, these illumination apertures were empirically designed based on empirical criteria related to the shape of the PTF, leaving the underlying theoretical mechanisms unexplored. Furthermore, the frequency responses of the PTFs under\nthese engineered illuminations have not been fully optimized, leading to suboptimal phase contrast and signal-to-noise ratio (SNR) for phase reconstruction. In this Letter, we provide a rigorous theoretical analysis about the necessary and sufficient conditions for DPC to achieve\nperfectly isotropic PTF. In addition, we derive the optimal illumination scheme to maximize the frequency response for both low and high frequencies (from 0 to 2N Aob j), and meanwhile achieve perfectly isotropic PTF with only 2-axis intensity measurements. We present the derivation, implementation, simulation and experimental results demonstrating the superiority of our method over state-of-the-arts in both phase reconstruction accuracy and noise-robustness.
Synthesis and in Vitro Evaluation of Bone-Seeking Superparamagnetic Iron Oxide Nanoparticles as Contrast Agents for Imaging Bone Metabolic Activity (2013)

In this article, we report the synthesis and in vitro evaluation of a new class of nonionizing bone-targeting contrast agents based on bisphosphonate-conjugated superparamagnetic iron oxide nanoparticles (SPIONs), for use in imaging of bone turnover with magnetic resonance imaging (MRI). Similar to bone-targeting (99m)Technetium medronate, our novel contrast agent uses bisphosphonates to impart bone-seeking properties, but replaces the former radioisotope with nonionizing SPIONs which enables their subsequent detection using MRI. Our reported method is relatively simple, quick and cost-effective and results in BP-SPIONs with a final nanoparticle size of 17 nm under electron microscopy technique (i.e., TEM). In-vitro binding studies of our novel bone tracer have shown selective binding affinity (around 65%) for hydroxyapatite, the principal mineral of bone. Bone-targeting SPIONs offer the potential for use as nonionizing MRI contrast agents capable of imaging dynamic bone turnover, for use in the diagnosis and monitoring of metabolic bone diseases and related bone pathology.
Feasibility study of spectral imaging for differential phase contrast cone beam CT: computer simulations (2013)

In principle, differential phase contrast (DPC) imaging allows the use of a hospital grade x-ray tube that has a large focal spot size and a wide polychromatic spectrum. It should be noted that due to the integration of interference patterns over the entire spectrum, the fringe contrast in the final intensity image is lower than that from a monochromatic spectrum. Therefore better image quality should be potentially obtained if the energy-dependent interference patterns can be analyzed separately. The key idea of the proposed spectral DPC imaging approach is to acquire DPC images for each photon energy channel, which is named spectral DPC images. The final DPC image can be computed by summing up these spectral DPC images or just computed using certain 'color' representation algorithms to enhance desired features. This research is a feasibility study based on computer simulations to investigate how the spectral DPC method works for a DPC-based cone beam CT (DPC-CBCT) system. The spectral DPC imaging approach is applied to an x-ray spectral centered at 30keV, which is divided into four energy channels in simulation. A simple numerical phantom with low contrast inserts is used and the entire imaging process is simulated using Fresnel diffraction theory. Phase stepping approach is used to manifest and retrieve phase information. The phantom is scanned over a full circular trajectory and the Hilbert filter-based FBP algorithm is used to compute the DPC-CBCT reconstruction. The reconstruction from the proposed spectral DPC-CBCT is compared to that from the conventional DPC-CBCT that only takes detector images for the integrated polychromatic spectrum. The uniformity, noise level and contrast of the inserts in the reconstruction are measured and compared. Simulation results indicate that the spectral DPC imaging approach can improve object contrast and reduce noise for DPC-CBCT.
A Stilbenoid-Specific Prenyltransferase Utilizes Dimethylallyl Pyrophosphate from the Plastidic Terpenoid Pathway (2016)

Prenylated stilbenoids synthesized in some legumes exhibit plant pathogen defense properties and pharmacological activities with potential benefits to human health. Despite their importance, the biosynthetic pathways of these compounds remain to be elucidated. Peanut (Arachis hypogaea) hairy root cultures produce a diverse array of prenylated stilbenoids upon treatment with elicitors. Using metabolic inhibitors of the plastidic and cytosolic isoprenoid biosynthetic pathways, we demonstrated that the prenyl moiety on the prenylated stilbenoids derives from a plastidic pathway. We further characterized, to our knowledge for the first time, a membrane-bound stilbenoid-specific prenyltransferase activity from the microsomal fraction of peanut hairy roots. This microsomal fraction-derived resveratrol 4-dimethylallyl transferase utilizes 3,3-dimethylallyl pyrophosphate as a prenyl donor and prenylates resveratrol to form arachidin-2. It also prenylates pinosylvin to chiricanine A and piceatannol to arachidin-5, a prenylated stilbenoid identified, to our knowledge, for the first time in this study. This prenyltransferase exhibits strict substrate specificity for stilbenoids and does not prenylate flavanone, flavone, or isoflavone backbones, even though it shares several common features with flavonoid-specific prenyltransferases.
“Arc Flash” Hazards, Incident Energy, PPE Ratings, and Thermal Burn Injury—A Deeper Look (2015)

Tremendous resources are being invested in arc flash studies and personal protective equipment (PPE) to protect workers from “arc flash” hazards. In the flurry to comply with OSHA regulations and NFPA 70 and 70E standards, the real understanding of the arc hazard and incident energy may be lagging behind. The term “arc flash” does not adequately convey the range of potential arc hazards-light, pressure, and heat transmission, as well as others. The term “arc flash” also fails to emphasize that arc flash injuries primarily arise from thermal burns and that the risk of a potentially severe or fatal arc burn is often present when performing electrical work. Worker risk assessment and the appropriate PPE are represented as definitive quantities in “cal/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ;” however, the quantitative potential heat exposure and heat protection afforded by PPE are usually less precise than what concrete numerical values imply. Basic concepts of incident energy, PPE ratings, and burn injury are also explored in this paper to help identify factors influencing the burn hazards posed by arcing faults in electrical power systems.
A Photographic Flux Mapping Method for Concentrating Solar Collectors and Receivers (2012)

A new method is described to determine irradiance distributions on receivers and targets from heliostats or other collectors for concentrating solar power applications. The method uses a digital camera, and, unlike previous beam characterization systems, it does not require additional sensors, calorimeters, or flux gauges on the receiver or target. In addition, spillage can exist and can also be measured (the beam does not need to be contained within the target). The only additional information required besides the images recorded from the digital camera is the direct normal irradiance and the reflectivity of the receiver. Methods are described to calculate either an average reflectivity or a reflectivity distribution for the receiver using the digital camera. The novel feature of this new photographic flux (PHLUX) mapping method is the use of recorded images of the sun to scale both the magnitude of each pixel value and the subtended angle of each pixel. A test was performed to evaluate the PHLUX method using a heliostat beam on the central receiver tower at the National Solar Thermal Test Facility in Albuquerque, NM. Results showed that the PHLUX method was capable of producing an accurate flux map of the heliostat beam on a Lambertian surface with a relative error in the peak flux of ∼2% when the filter attenuation factors and effective receiver reflectivity were well characterized. Total relative errors associated with the measured irradiance using the PHLUX method can be up to 20%–40%, depending on various error sources identified in the paper, namely, uncertainty in receiver reflectivity and filter attenuation.
George M. Cober Lecturer: Mark T. Keating. Molecular basis of the long-QT syndrome associated with deafness. (1997)

Jervell and Lange-Nielsen syndrome is an autosomal recessive form of long-QT syndrome. In addition to QT interval prolongation, this disorder is associated with congenital deafness. Jervell and Lange-Nielsen syndrome is rare, but affected individuals are susceptible to cardiac arrhythmias with a high incidence of sudden death and short life expectancy. A proband with Jervell and Lange-Nielsen syndrome and family members were ascertained and phenotypically characterized. Linkage, mutational, and DNA sequence analyses were used to define the genetic basis of this disorder. We found that the proband had long-QT syndrome and sensory deafness. Some family members also had QTc prolongation with an autosomal dominant pattern of inheritance, but these patients had normal hearing. The gene responsible for QTc prolongation in this family was mapped to chromosome 11p15.5 using linkage analyses. The maximum LOD score at D11S1318 was 5.46, indicating odds greater than 100,000:1 favoring linkage. Mutation analyses revealed a single base pair insertion in KVLQT11, the potassium channel gene responsible for chromosome 11-linked long-QT syndrome. This mutation caused a premature stop codon. All family members with QTc prolongation, except the proband, were heterozygous for the mutation. The proband with Jervell and Lange-Nielsen syndrome resulted from a consanguineous marriage and was homozygous for the KVLQT1 mutation. Homozygous mutation of KVLQT1 causes Jervell and Lange-Nielsen syndrome. Members of Jervell and Lange-Nielsen syndrome families should be examined for long-QT syndrome, even if they have normal hearing.
Server Staffing to Meet Time-Varying Demand (1996)

We consider a multiserver service system with general nonstationary arrival and service-time processes in which s(t), the number of servers as a function of time, needs to be selected to meet projected loads. We try to choose s(t) so that the probability of a delay (before beginning service) hits or falls just below a target probability at all times. We develop an approximate procedure based on a time-dependent normal distribution, where the mean and variance are determined by infinite-server approximations. We demonstrate that this approximation is effective by making comparisons with the exact numerical solution of the Markovian M t /M/s t model.
Edge-guided resolution enhancement in projectors via optical pixel sharing (2012)

Digital projection technology has improved significantly in recent years. But, the relationship of cost with respect to available resolution in projectors is still super-linear. In this paper, we present a method that uses projector light modulator panels (e.g. LCD or DMD panels) of resolution n X n to create a perceptually close match to a target higher resolution cn X cn image, where c is a small integer greater than 1. This is achieved by enhancing the resolution using smaller pixels at specific regions of interest like edges.
Predicting Cyber Threats with Virtual Security Products (2017)

Cybersecurity analysts are often presented suspicious machine activity that does not conclusively indicate compromise, resulting in undetected incidents or costly investigations into the most appropriate remediation actions. There are many reasons for this: deficiencies in the number and quality of security products that are deployed, poor configuration of those security products, and incomplete reporting of product-security telemetry. Managed Security Service Providers (MSSP's), which are tasked with detecting security incidents on behalf of multiple customers, are confronted with these data quality issues, but also possess a wealth of cross-product security data that enables innovative solutions. We use MSSP data to develop Virtual Product, which addresses the aforementioned data challenges by predicting what security events would have been triggered by a security product if it had been present. This benefits the analysts by providing more context into existing security incidents (albeit probabilistic) and by making questionable security incidents more conclusive. We achieve up to 99% AUC in predicting the incidents that some products would have detected had they been present.