gebhart/patrepeval huggingface dataset:
Local Self-Attention over Long Text for Efficient Document Retrieval (2020)

Neural networks, particularly Transformer-based architectures, have achieved significant performance improvements on several retrieval benchmarks. When the items being retrieved are documents, the time and memory cost of employing Transformers over a full sequence of document terms can be prohibitive. A popular strategy involves considering only the first n terms of the document. This can, however, result in a biased system that under retrieves longer documents. In this work, we propose a local self-attention which considers a moving window over the document terms and for each term attends only to other terms in the same window. This local attention incurs a fraction of the compute and memory cost of attention over the whole document. The windowed approach also leads to more compact packing of padded documents in minibatches resulting in additional savings. We also employ a learned saturation function and a two-staged pooling strategy to identify relevant regions of the document. The Transformer-Kernel pooling model with these changes can efficiently elicit relevance information from documents with thousands of tokens. We benchmark our proposed modifications on the document ranking task from the TREC 2019 Deep Learning track and observe significant improvements in retrieval quality as well as increased retrieval of longer documents at moderate increase in compute and memory costs.
Integrating Reverse Transcription Recombinase Polymerase Amplification with CRISPR Technology for the One-Tube Assay of RNA (2021)

CRISPR-Cas systems integrated with nucleic acid amplification techniques improve both analytical specificity and sensitivity. We describe here issues and solutions for the successful integration of reverse transcription (RT), recombinase polymerase amplification (RPA), and CRISPR-Cas12a nuclease reactions into a single tube under an isothermal condition (40 °C). Specific detection of a few copies of a viral DNA sequence was achieved in less than 20 min. However, the sensitivity was orders of magnitude lower for the detection of viral RNA due to the slow initiation of RPA when the complementary DNA (cDNA) template remained hybridized to RNA. During the delay of RPA, the crRNA-Cas12a ribonucleoprotein (RNP) gradually lost its activity in the RPA solution, and nonspecific amplification reactions consumed the RPA reagents. We overcame these problems by taking advantage of the endoribonuclease function of RNase H to remove RNA from the RNA-cDNA hybrids and free the cDNA as template for the RPA reaction. As a consequence, we significantly enhanced the overall reaction rate of an integrated assay using RT-RPA and CRISPR-Cas12a for the detection of RNA. We showed successful detection of 200 or more copies of the S gene sequence of SARS-CoV-2 RNA within 5-30 min. We applied our one-tube assay to 46 upper respiratory swab samples for COVID-19 diagnosis, and the results from both fluorescence intensity measurements and end-point visualization were consistent with those of RT-qPCR analysis. The strategy and technique improve the sensitivity and speed of RT-RPA and CRISPR-Cas12a assays, potentially useful for both semi-quantitative and point-of-care analyses of RNA molecules.
Enhancement and localization of atomistic polarity and polarizability memory in light scattering upon hydrogenation of luminescent spherical 1 nm Si nanoparticles (2023)

The classical light interactions of nanosilicon, which is a dielectric material, are exceedingly weak for radius r ≪ λ (wavelength), scaling as r6. It exhibits geometrical anisotropy-based depolarization, which is the basis for the very weak response in isotropic structures (nanosphere). Recently, surface enhanced Raman scattering (SERS) in DNA decorated with ultrasmall Si nanoparticles has been demonstrated, affording an effective alternative to plasmon–metal particles. In this paper, we execute fundamental quantum atomistic computation of 1 nm hydrogenated Si particles, with different surface reconstruction and termination, including Si–H, H–Si–Si–H (dimer molecules), or oxygenated dimer bridges (H–Si–O–Si–H). We obtain the mechanical vibrational modes of the particles. Our results show that by changing the surface configuration one can control the symmetry and normal vibration modes, and enhance the polarizability, polarity, and light interactions (scattering, absorption, and depolarization/memory). The low frequency polarizability (Raman scattering) shifts spatially from the interior to the surface, while the infrared polarity remains on the surface, but its bandwidth narrows spectrally. The results support previous infrared absorption and light scattering and depolarization measurements, as well recent SERS, which enable Si nanoparticles to be an effective alternative to plasmonic metal particles. Molecular surface reconstruction in terms of Si dimers and bridges were suggested as the source of the novel nonlinear and anisotropic luminescence and photonic properties of Si nanoparticles. Such control affords potential for optimizing the design and operation of a wide range of opto-electronic advanced scattering and luminescence devices.
ChemInform Abstract: A Concise Synthesis of Optically Active 2‐Bromotryptophan Amino Acids Present in Konbamide and Jaspamide via a Regiospecific Bromination Procedure. (1996)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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.
Vibration-induced size separation in granular media: The convection connection (1993)

We have investigated the rise of a single large glass bead through a vibrated cylindrical column of smaller particles and found that vibration-induced size separation in this geometry arises from convective processes rather than from local rearrangements as had been proposed previously. A convection cycle, rising in the middle and dropping in a thin stream along the walls of the cell, is responsible for all particle movement. Particles larger than the width of the thin downward convection zone are carried to the top of the column and then trapped, resulting in size segregation. For a variety of accelerations the position of the rising particle can be scaled onto a single curve.
Selecting relevant text subsets from web-data for building topic specific language models (2006)

In this paper we present a scheme to select relevant subsets of sentences from a large generic corpus such as text acquired from the web. A relative entropy (R.E) based criterion is used to incrementally select sentences whose distribution matches the domain of interest. Experimental results show that by using the proposed subset selection scheme we can get significant performance improvement in both Word Error Rate (WER) and Perplexity (PPL) over the models built from the entire web-corpus by using just 10% of the data. In addition incremental data selection enables us to achieve significant reduction in the vocabulary size as well as number of n-grams in the adapted language model. To demonstrate the gains from our method we provide a comparative analysis with a number of methods proposed in recent language modeling literature for cleaning up text.
Indirect-Feedback Sigma-Delta Image Sensors: Theory, Modeling and Design (2013)

A novel architecture for a CMOS image sensor that incorporates a column-level sigma-delta (ΣΔ) analog-to-digital converter is presented. An indirect-feedback readout architecture where the digital output of the ΣΔ modulator is accumulated by a digital counter and converted to an analog voltage that serves as the reference voltage in the modulator's comparator is employed. A time-domain pixel simulator that enables assessment of the major noise contributions in this type of imager is also presented. Theoretical calculations agree with simulation results, showing a minimum readout noise of 2.18e- and a dynamic range (DR) of over 100 dB. Prototype chip tests without multiple resets show an 87 dB dynamic range with a readout noise of 2.17e-.
Turning it off! Disfavouring hydrogen evolution to enhance selectivity for CO production during homogeneous CO2 reduction by cobalt–terpyridine complexes (2015)

Understanding the activity and selectivity of molecular catalysts for CO<sub>2</sub> reduction to fuels is an important scientific endeavour in addressing the growing global energy demand. Cobalt-terpyridine compounds have been shown to be catalysts for CO<sub>2</sub> reduction to CO while simultaneously producing H<sub>2</sub> from the requisite proton source. To investigate the parameters governing the competition for H<sup>+</sup> reduction <i>versus</i> CO<sub>2</sub> reduction, the cobalt bisterpyridine class of compounds is first evaluated as H<sup>+</sup> reduction catalysts. We report that electronic tuning of the ancillary ligand sphere can result in a wide range of second-order rate constants for H<sup>+</sup> reduction. When this class of compounds is next submitted to CO<sub>2</sub> reduction conditions, a trend is found in which the less active catalysts for H<sup>+</sup> reduction are the more selective towards CO<sub>2</sub> reduction to CO. This represents the first report of the selectivity of a molecular system for CO<sub>2</sub> reduction being controlled through turning off one of the competing reactions. The activities of the series of catalysts are evaluated through <i>foot-of-the-wave</i> analysis and a catalytic Tafel plot is provided.
Loss Characteristics of MnMgZn Ferrite. (1995)

Deterioration of initial permeability (μi) with respect to frequency and ef ect of Fe2+ on low core loss has been investigated with reference to chemical composition, sintering condition and microstructure on the MnMgZn ferrites. Frequency deterioration of μi increased with MnO addition to the MgZn ferrite most likely. This seems due to a relaxation phenomenon. Relaxation time (τ) and activation energy (Q) were calculated by using the relationshipsωτ=1 and the Bolzmann factor. Activation energies for MgZn and MnMgZn ferrites were found to be 0.14eV and 0.36eV, respectively. Results suggest that the diffusion magnetic aftereffect of MgZn and MnMgZn ferrites is generated by electron and cation migrations, respectively.
Multiple-Parameter, Low-False-Alarm Fire-Detection Systems (2007)

Fire-detection systems incorporating multiple sensors that measure multiple parameters are being developed for use in storage depots, cargo bays of ships and aircraft, and other locations not amenable to frequent, direct visual inspection. These systems are intended to improve upon conventional smoke detectors, now used in such locations, that reliably detect fires but also frequently generate false alarms: for example, conventional smoke detectors based on the blockage of light by smoke particles are also affected by dust particles and water droplets and, thus, are often susceptible to false alarms. In contrast, by utilizing multiple parameters associated with fires, i.e. not only obscuration by smoke particles but also concentrations of multiple chemical species that are commonly generated in combustion, false alarms can be significantly decreased while still detecting fires as reliably as older smoke-detector systems do. The present development includes fabrication of sensors that have, variously, micrometer- or nanometer-sized features so that such multiple sensors can be integrated into arrays that have sizes, weights, and power demands smaller than those of older macroscopic sensors. The sensors include resistors, electrochemical cells, and Schottky diodes that exhibit different sensitivities to the various airborne chemicals of interest. In a system of this type, the sensor readings are digitized and processed by advanced signal-processing hardware and software to extract such chemical indications of fires as abnormally high concentrations of CO and CO2, possibly in combination with H2 and/or hydrocarbons. The system also includes a microelectromechanical systems (MEMS)-based particle detector and classifier device to increase the reliability of measurements of chemical species and particulates. In parallel research, software for modeling the evolution of a fire within an aircraft cargo bay has been developed. The model implemented in the software can describe the concentrations of chemical species and of particulate matter as functions of time. A system of the present developmental type and a conventional fire detector were tested under both fire and false-alarm conditions in a Federal Aviation Administration cargo-compartment- testing facility. Both systems consistently detected fires. However, the conventional fire detector consistently generated false alarms, whereas the developmental system did not generate any false alarms.
One-Stage Repair of Salmonella enteritidis-Infected Infrarenal Aortic Aneurysm (1994)

A sixty-three-year-old man was admitted with systemic sepsis, but he was in a hemody namically stable situation and found to have a contained rupture of an infrarenal aortic aneurysm, which was infected with Salmonella enteritidis. An abdominal plain film revealed a gas shadow forming a ring in the midabdomen. Computed tomography (CT) showed a contained rupture of an infrarenal aortic aneurysm with a gas formation in the retroperitoneum. An emergent extra-anatomic bypass from the ascending aorta to ( continued on next page) ( Abstract continued) the femoral arteries was performed. The retroperitoneal phlegmon and hematoma that contained a large pseudoaneurysm were removed through a separate incision. A CT obtained after surgery showed gas-containing fluid collections in the retroperitoneum and these were followed up by means of CT. Eight months after surgery, the fluid collec tions had resolved. Aggressive surgical treatment and antibiotic therapy have resulted in a successful outcome.
Abstract 1600: A xenograft model of spontaneous metastases in NOD SCID mice of human non-small cell lung cancer (2011)

Abstract Introduction: Xenograft models of human non small cell lung cancer cell lines have been unreliable in studying distal organ metastases. Although the flank, as a primary xenograft site, is typically used for the convenience of measurement, rarely do even the most aggressive cell lines develop metastases. Methods: Using 15 anesthetized NOD.CB17-Prkdcscid/NcrCrl (NOD/SCID) mice, we xenografted 10,000 A549 cells into the liver under direct visualization and allowed the tumors to grow for 7 weeks. The mice were then euthanized, perfused with formalin, and grossly dissected. The liver, lung and spleen were processed, embedded in paraffin, sectioned and stained. A second group of 7 NOD/SCID mice were subsequently xenografted in the liver with A549, and a mouse each week was euthanized for 7 weeks and evaluated. Results: At 7 weeks, all 15 mice had gross primary tumor in the liver as well as grossly evident splenic (10/15) and mediastinal metastases (5/15). There were no gross pulmonary metastases observed (0/15). Histologic review, however, confirmed multiple microscopic foci of metastatic disease in all mice (15/15) throughout the lungs bilaterally, the mediastinal lymph nodes and spleen. Serially euthanized mice revealed histological evidence of a gradual spontaneous metastatic model system. Histologically evident primary tumor was apparent by week 1 with gross primary tumor development in the liver by week 2. Weeks 3 and 4 showed gross and histologic progression of primary tumor size with no apparent evidence of microscopic distal metastases. By week 5, the first histological findings of micrometastases appeared in the lungs which became wide spread in all the pulmonary parenchyma by week 7. Splenic and mediastinal lymph node involvement were observed histologically by week 6. Conclusions: Liver xenografting of A549 into NOD/SCID mice is a reliable way of developing widespread micrometastases to the lungs, mediastinal lymph nodes, and spleen. This model is clinically relevant since, unlike tail vein injection, it allows the study of the biology and treatment of a gradually developing primary lung tumor with subsequent metastatic spread. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1600. doi:10.1158/1538-7445.AM2011-1600
Efficient and Privacy-Preserving Certificate Activation for V2X Pseudonym Certificate Revocation (2022)

Vehicle to everything (V2X) technology allows the broader development of driving safety, efficiency, and comfort. Because the vehicles can quickly send and receive frequent messages from other vehicles and nearby devices, e.g., cooperative awareness message applications on the intelligent transport system (ITS), V2X requires a good security and privacy protection system to make the messages reliable for the ITS requirements. The existing standards developed in the US and Europe use many short valid period pseudonym certificates to meet the security and privacy requirements. However, this method has difficulty ensuring that revoked pseudonym certificates are treated as revoked by any vehicles because distributing revocation information on a wireless vehicular network with intermittent and rapidly changing topology is demanding. A promising approach to solving this problem is the periodic activation of released pseudonym certificates. Initially, it releases all required pseudonym certificates for a certain period to the vehicle, and pseudonym certificates can be used only after receiving an activation code. Such activation-code-based schemes have a common problem in the inefficient use of network resources between the road-side unit (RSU) and vehicles. This paper proposes an efficient and privacy-preserving activation code distribution strategy solving the problem. By adopting the unicast distribution model of modified activation code for pseudonym certificate (ACPC), our scheme can obtain benefits of efficient activation code distribution. The proposed scheme provides small communication resource usage in the V2X network with various channel options for delivering activation codes in a privacy preserved manner.
<title>Size-dependent spectroscopy and photodynamics of some II-VI semiconductor nanocrystallites (quantum dots)</title> (1993)

The relaxation dynamics of photoexcited CdSe nanocrystallites (quantum dots) are dominated by the surface. Surface electronic properties of CdSe nanocrystallites have been probed using low temperature fluorescence line narrowing and time resolved luminescence. We find that the surface structure creates a random potential for the hole with a size dependent barrier for site to site hopping.
Buried Power Rail Integration With FinFETs for Ultimate CMOS Scaling (2020)

Buried power rail (BPR) is a key scaling booster for CMOS extension beyond the 5-nm node. This work demonstrates, for the first time, the integration of tungsten (W) BPR lines with Si finFETs. BPR technology requires insertion of metal in the front-end-of-line (FEOL) stack. This poses risks of stack deformation and device degradation due to metal-induced stress and contamination. To assess the stack deformation, we demonstrate W-BPR lines which can withstand source/drain activation anneal at 1000 °C, 1.5 s, without adversely impacting the stack morphology. To address the contamination risk, we demonstrate a BPR process module with controlled W recess and void-free dielectric plug formation which keeps the W-line fully encapsulated during downstream FEOL processing. Suitable choice of BPR metal such as W with high melting point which does not diffuse into dielectrics also minimizes the risk of contamination. To assess the device degradation, simulations are carried out showing negligible stress transfer from BPR to the channel. This is experimentally validated when no systematic difference in the dc characteristics of CMOS without BPR versus those in close proximity to floating W-BPR lines is observed. Additionally, the resistance of the recessed W-BPR line is measured ~120 Ω/μm for critical dimension (CD) ~32 nm and height ~122 nm. The recessed W-BPR interface with Ru 3-nm TiN liner via contact can withstand more than 1000 h of electromigration (EM) stress at 6.6 MA/cm2 and 330 °C, making Ru a candidate for via metallization to achieve low resistance contact strategy to BPR.
Ionic liquid promoted novel and efficient one pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones at ambient temperature under ultrasound irradiation (2004)

3,4-Dihydropyrimidin-2-(1H)-ones have been synthesized in excellent yields in short reaction time at ambient temperature in the absence of any added catalyst by the reaction of aromatic or aliphatic aldehydes with ethyl acetoacetate (EAA) and urea (or thiourea) in room temperature ionic liquid (IL) under ultrasound irradiation. The evidence for the role of IL in promoting this multicomponent reaction has been given. Based on this evidence, a plausible mechanistic pathway has been postulated.
Novel fabrication of 3-D microstructures by volume oxidation of AlGaAs (2004)

A novel method for fabricating AIGaAs microstructures is investigated. The process consists of a thermal volume oxidation of AIGaAs/GaAs epitaxy and selective etching of the resulting aluminum oxide.
Iterative Concave Rank Approximation for Recovering Low-Rank Matrices (2014)

In this paper, we propose a new algorithm for recovery of low-rank matrices from compressed linear measurements. The underlying idea of this algorithm is to closely approximate the rank function with a smooth function of singular values, and then minimize the resulting approximation subject to the linear constraints. The accuracy of the approximation is controlled via a scaling parameter δ, where a smaller δ corresponds to a more accurate fitting. The consequent optimization problem for any finite δ is nonconvex. Therefore, to decrease the risk of ending up in local minima, a series of optimizations is performed, starting with optimizing a rough approximation (a large δ) and followed by successively optimizing finer approximations of the rank with smaller δ's. To solve the optimization problem for any δ > 0, it is converted to a new program in which the cost is a function of two auxiliary positive semidefinite variables. The paper shows that this new program is concave and applies a majorize-minimize technique to solve it which, in turn, leads to a few convex optimization iterations. This optimization scheme is also equivalent to a reweighted Nuclear Norm Minimization (NNM). For any δ > 0, we derive a necessary and sufficient condition for the exact recovery which are weaker than those corresponding to NNM. On the numerical side, the proposed algorithm is compared to NNM and a reweighted NNM in solving affine rank minimization and matrix completion problems showing its considerable and consistent superiority in terms of success rate.