gebhart/patrepeval huggingface dataset:
ChemInform Abstract: SYNTHESIS AND ANTIARRHYTHMIC ACTIVITY OF SUBSTITUTED (2‐PYRIMIDINYLTHIO)ACETAMIDOXIMES (1975)

Abstract Aus den 2‐Mercapto‐pyrimidinolen (I) entstehen mit Chloracetamid die Substitutionsprodukte (II), die mit Phosphoroxychlorid die Nitrile (III) ergeben.
Petri net-based deadlock avoidance for single-arm cluster tools with concurrently processing two-type wafers (2018)

A modern fabrication tends to arrange different wafer types with similar recipes in a lot in order to increase the utilization of cluster tools, meet the demand of customization, and improve the flexibility of the system. Nevertheless, the wafer flow patterns of the different wafer types may be different such that cluster tools are deadlock-prone. This work aims at solving the deadlock problem of single-arm cluster tools with concurrently processing two wafer types. In order to solve it, the deadlock analysis of the system is conducted. Then, a general Petri net (PN) model is developed for the system. Furthermore, a novel method called the PN-based earliest starting strategy is proposed for the system such that the system can operate without deadlock. Moreover, such a method can be used for real-time scheduling. Therefore, it is significant for semiconductor manufacturing.
Protection and transmission of side information for peak-to-average power ratio reduction of an OFDM signal using partial transmit sequences (2003)

The peak-to-average power ratio (PAPR) problem of OFDM systems can be efficiently resolved using partial transmit sequences (PTS) method, for which data recovery requires side information (SI) about the phase rotation factors used at transmitter. Regarding the PTS method, two low-complexity schemes are proposed for protecting the SI via error correction coding. OFDM modulation of the coded SI and that of data are performed separately, giving the benefit of considerably reduced complexity. Simulation results demonstrate the good performance of the proposed schemes at the expense of requiring a little additional subcarriers for SI protection.
Dynamic quantum clustering: A method for visual exploration of structures in data (2009)

A given set of data points in some feature space may be associated with a Schrödinger equation whose potential is determined by the data. This is known to lead to good clustering solutions. Here we extend this approach into a full-fledged dynamical scheme using a time-dependent Schrödinger equation. Moreover, we approximate this Hamiltonian formalism by a truncated calculation within a set of Gaussian wave functions (coherent states) centered around the original points. This allows for analytic evaluation of the time evolution of all such states opening up the possibility of exploration of relationships among data points through observation of varying dynamical distances among points and convergence of points into clusters. This formalism may be further supplemented by preprocessing such as dimensional reduction through singular-value decomposition or feature filtering.
Electrically Tunable Thermal-Infrared Metamaterials (2010)

We experimentally demonstrate that the resonance of a thermal-infrared metamaterial on a semiconductor substrate can be shifted by the substrate doping. We further study the electrical tuning of metamaterial resonance via finite integral time-domain simulation.
The Eigentrust algorithm for reputation management in P2P networks (2003)

Peer-to-peer file-sharing networks are currently receiving much attention as a means of sharing and distributing information. However, as recent experience shows, the anonymous, open nature of these networks offers an almost ideal environment for the spread of self-replicating inauthentic files.We describe an algorithm to decrease the number of downloads of inauthentic files in a peer-to-peer file-sharing network that assigns each peer a unique global trust value, based on the peer's history of uploads. We present a distributed and secure method to compute global trust values, based on Power iteration. By having peers use these global trust values to choose the peers from whom they download, the network effectively identifies malicious peers and isolates them from the network.In simulations, this reputation system, called EigenTrust, has been shown to significantly decrease the number of inauthentic files on the network, even under a variety of conditions where malicious peers cooperate in an attempt to deliberately subvert the system.
Breathing sounds characteristics correlate with structural changes of upper airway due to obstructive sleep apnea (2015)

This paper reports on a pilot study of acoustic properties of respiratory sounds in relation to obstructive sleep apnea (OSA). Data were breathing sounds of 60 individuals in three groups of non-, Moderate and Severe OSA using the apnea/hypopnea index (AHI) (20 in each group). The sounds power spectral energy and phase responses were calculated for each respiratory phase, and investigated among the groups. The results of power spectral analysis, congruent with imaging studies' findings, suggest a regional narrowing in upper airway that shows its effect in low and high frequencies as an opposite pattern between the OSA and non-OSA groups. The results of phase analysis also support an increased nonlinearity in high frequencies that is speculated to be related to the regional narrowing and thus regional elasticity of the airway during wakefulness.
Inter-Technology Backscatter (2017)

We introduce inter-technology backscatter, a novel approach that transforms wireless transmissions from one technology to another, on the air. We show for the first time that Bluetooth transmissions can be used to create Wi-Fi and ZigBee-compatible signals using backscatter communication. Since Bluetooth, Wi-Fi and ZigBee radios are widely available, this enables a backscatter design that works using only commodity devices. We build an FPGA prototype that creates 2'11 Mbps Wi-Fi or Zigbee packets by backscattering Bluetooth transmissions. We use this to demonstrate previously infeasible applications including the first contact lens form-factor antenna prototype and implantable neural recording interface that communicate directly to commodity devices, such as smartphones, thus enabling the vision of Internet-connected implanted devices
Ionic Switch Induced by a Rectangular–Hexagonal Phase Transition in Benzenammonium Columnar Liquid Crystals (2015)

We demonstrate switching of ionic conductivities in wedge-shaped liquid-crystalline (LC) ammonium salts. A thermoreversible phase transition between the rectangular columnar (Colr) and hexagonal columnar (Colh) phases is used for the switch. The ionic conductivities in the Colh phase are about four orders of magnitude higher than those in the Colr phase. The switching behavior of conductivity can be ascribed to the structural change of assembled ionic channels. X-ray experiments reveal a highly ordered packing of the ions in the Colr phase, which prevents the ion transport.
Algorithms and architectures for performing Boolean equations using self electro-optic effect devices (1991)

This paper documents an investigation on the architectures and algorithms for performing logic (or Boolean equations) using self electro-optic effect devices (SEEDs). Three algorithms and architectures for performing logic are examined -- using lookup tables with series connected SEEDs (or Symmetric-SEEDs), using a preset cycle with series connected SEEDs, and using NMOS and CMOS architectures. Contrasts are examined between the architectures with cascadeability, component, and optical interconnectivity considerations.
Autofocusing circular synthetic aperture sonar imagery using phase corrections modeled as generalized cones (2014)

Circular synthetic aperture sonar (CSAS) is a coherent aperture synthesis technique that utilizes backscattered acoustic information from an encircled scene to generate information rich, high-resolution imagery. The aperture length required for image synthesis is much longer than in its linear synthetic aperture sonar counterpart and can result in challenging phase delay and navigation estimation constraints. Residual uncorrected phase errors manifest as focus aberrations in reconstructed CSAS imagery. This paper demonstrates that phase error in image patches can be approximated as an aspect variant linear phase shift representable as a generalized cone in wave-number space. If the geometry of the generalized cone is known, it can be applied as the spectral phase of an inverse filter for aberration correction. A method is derived for reconstructing the error cone geometry from independent estimates of its local curvatures, which are found via a series of one-dimensional line searches that maximize the focus of CSAS sub-aperture images. This approach is applied to real and simulated CSAS data containing aperture distortions, and the results successfully demonstrate estimation and correction of the underlying focus aberrations.
A delta-configured auxiliary resonant snubber inverter (1996)

A delta (/spl Delta/)-configured auxiliary resonant snubber inverter is developed to overcome the voltage floating problem in a wye (Y)-configured resonant snubber inverter. The proposed inverter is to connect auxiliary resonant branches between phase outputs to avoid a floating point voltage which may cause overvoltage failure of the auxiliary switches. Each auxiliary branch consists of a resonant inductor and a reverse blocking auxiliary switch. Instead of using an antiparalleled diode to allow resonant current to flow in the reverse direction, as in the Y-configured version, the resonant branch in the /spl Delta/-configured version must block the negative voltage, typically done by a series diode. This paper shows single-phase and three-phase versions of /spl Delta/-configured resonant snubber inverters and describes in detail the operating principle of a single-phase version. The extended three-phase version is proposed with nonadjacent state space vector modulation. For hardware implementation, a single-phase 1-kW unit and a three-phase 100-kW unit were built to prove the concept. Experimental results show the superiority of the proposed topology.
Short report: characterization of enteroaggregative Escherichia coli isolates from Iranian children. (2001)

We have previously shown that enteroaggregative Escherichia coli (EAEC) is an important pathogen among Iranian infants and children. To better understand the characteristics of EAEC in Iran, we analyzed EAEC isolates for the presence of pAA plasmid-borne factors. Ninety-eight E. coli strains that displayed the aggregative adherence (AA) pattern on HeLa cells were hybridized with the CVD432 (AA) probe and with genes encoding enteroaggregative heat-stable enterotoxin-1 and aggregative adherence fimbriae (AAF) I and II. Our data suggest that AAF/II is common in this population and that AAF/I and AAF/II can sometimes be detected in the same E. coli isolate. Surprisingly, we have found that AA probe-negative strains in Iran share virulence factors with AA probe-positive isolates and therefore may be more similar to probe-positive strains than previously believed.
Slow Light Imaging Spectroscopy (2020)

Slow Light Imaging Spectroscopy has the potential to provide high spectral resolution while preserving an imaging capability for Rayleigh, Raman and Thomson scattering. This paper examines the extinction ratio and optimum time delay associated with a rubidium vapor cell and Rayleigh/Mie scattering at 780nm. Extinction ratios of better than 1000 are measured, and it is expected that much greater extinction can be achieved with better optimized laser systems.
Genetic and Molecular Characterization of the<i>VRN2</i>Loci in Tetraploid Wheat     (2008)

Winter wheat (Triticum spp.) varieties require long exposures to low temperatures to flower, a process called vernalization. The VRN2 locus includes two completely linked zinc finger-CCT domain genes (ZCCT1 and ZCCT2) that act as flowering repressors down-regulated during vernalization. Deletions or mutations in these two genes result in the elimination of the vernalization requirement in diploid wheat (Triticum monococcum). However, natural allelic variation in these genes has not been described so far in polyploid wheat (tetraploid Triticum turgidum and hexaploid Triticum aestivum). A tetraploid wheat population segregating for both VRN-A2 and VRN-B2 loci facilitated the characterization of different alleles. Comparisons between functional and nonfunctional alleles revealed that both ZCCT1 and ZCCT2 genes are able to confer vernalization requirement and that different ZCCT genes are functional in different genomes. ZCCT1 and ZCCT2 proteins from nonfunctional vrn2 alleles have mutations at arginine amino acids at position 16, 35, or 39 of the CCT domain. These positions are conserved between CCT and HEME ACTIVATOR PROTEIN2 (HAP2) proteins, supporting a model in which the action of CCT domains is mediated by their interactions with HAP2/HAP3/HAP5 complexes. This study also revealed natural variation in gene copy number, including a duplication of the functional ZCCT-B2 gene and deletions or duplications of the complete VRN-B2 locus. Allelic variation at the VRN-B2 locus was associated with a partially dominant effect, which suggests that variation in the number of functional ZCCT genes can be used to expand allelic diversity for heading time in polyploid wheat and, hopefully, improve its adaptation to different environments.
Variants of the β1,3-Galactosyltransferase CgtB from the Bacterium Campylobacter Jejuni have Distinct Acceptor Specificities (2007)

The gene clusters encoding the lipooligosaccharide biosynthesis glycosyltransferases from Campylobacter jejuni have previously been divided in eight classes based on their genetic organization. Here, three variants of the beta1,3-galactosyltransferase CgtB from two classes were purified as fusions with the maltose-binding protein (MalE) from Escherichia coli and their acceptor preference was determined. The acceptor preference of each CgtB variant was directly related to the presence or absence of sialic acid in the acceptor, which correlated with the core oligosaccharide structure in vivo. The three variants were evaluated for their ability to use a derivitized monosaccharide, a GM2 ganglioside mimic, a GA2 ganglioside mimic as well as a peptide containing alpha-linked GalNAc. This characterization shows the flexibility of these galactosyltransferases for diverse acceptors. The CgtB variants were engineered via carboxy-terminal deletions and inversion of the gene fusion order. The combination of a 20 to 30 aa deletion in CgtB followed by MalE at its carboxy terminus significantly improved the glycosyltransferase activity (up to a 51.8-fold increase of activity compared to the full length enzyme) in all cases regardless of the acceptor tested. The improved enzyme CgtB(OH4384)DeltaC-MalE was used to galactosylate a glyco-peptide acceptor based on the interferon alpha2b protein O-linked glycosylation site as confirmed by the CE-MS analysis of the reaction products. This improved enzyme was also used successfully to galactosylate the human therapeutic protein IFNalpha2b[GalNAcalpha]. This constitutes the first report of the in vitro synthesis of the O-linked T-antigen glycan on a human protein by a bacterial glycosyltransferase and illustrates the potential of bacterial glycosyltransferases as tools for in vitro glycosylation of human proteins of therapeutic value.
Development of a Biologic Prosthetic Composite for Cartilage Repair (2005)

At present there is no satisfactory treatment for deep osteochondral defects. Here we report the development of a biologic prosthetic composite containing periosteum from 2-month-old rabbits and a porous tantalum scaffold. When cultured under chondrogenic conditions, the composites form a robust hyaline-like cartilage outgrowth that is attached to the porous scaffold by fibrous tissue ingrowth. The mechanical properties of these composites are similar to those of normal osteochondral plugs after only 6 weeks in culture. Thus, porous tantalum scaffolds are compatible with the chondrogenic capacity of periosteum. We hypothesize that these periosteum-porous tantalum composites will be useful for the repair of major osteochondral defects. However, in vivo experiments using biological resurfacing of large osteochondral defects with a porous tantalum scaffold and autologous periosteal graft in animal models are necessary to further explore this possibility. The implications of a successful method for cartilage regeneration would be great in terms of the number of patients affected and the quality of life for each of those patients.
Characterization of the chemical structure and innate immune-stimulating activity of an extracellular polysaccharide from <i>Rhizobium</i> sp. strain M2 screened using a silkworm muscle contraction assay (2017)

We screened innate immunostimulant-producing bacteria using a silkworm muscle contraction assay, and isolated Rhizobium sp. strain M2 from soil. We purified the innate immunostimulant from strain M2, and characterized the chemical structure by nuclear magnetic resonance spectroscopy and chemical analyses. The innate immunostimulant (M2 EPS) comprised glucose, galactose, pyruvic acid, and succinic acid with a molar ratio of 6.8:1.0:0.9:0.4, and had a succinoglycan-like high molecular-weight heteropolysaccharide structure. To determine the structural motif involved in the innate immunostimulating activity, we modified the M2 EPS structure chemically, and found that the activity was increased by removal of the succinic and pyruvic acid substitutions. Strong acid hydrolysis completely inactivated the M2 EPS. Unmasking of the β-1,3/6-glucan structure of the side-chain by deacylation and depyruvylation may enhance the innate immune-stimulating activity of M2 EPS. These findings suggest that the succinoglycan-like polysaccharide purified from strain M2 has innate immune-stimulating activity, and its glycan structure is necessary for the activity.
Backside picosecond timing measurements on CMOS integrated circuits (2001)

The timing of switching transitions at the gate level with picosecond accuracy is now an important part of creating high performance integrated circuits (ICs). This need has led to the development of new optical probes to provide local information about electrical activity in flip-chip packaged ICs without disassembly of the chip. The tools use the fact that light at wavelengths near 1 ③m can penetrate hundreds of microns into silicon, providing a useful probe from the chip’s backside. At the same time, optical techniques are now capable of resolving time intervals of picoseconds. These measurement tools include completely passive methods, active methods that can be non- or weakly perturbative, and methods that deliberately perturb the operation of a circuit.
A class of efficient-encoding generalized low-density parity-check codes (2002)

In this paper, we investigate an efficient encoding approach for generalized low-density (GLD) parity check codes, a generalization of Gallager's (1962, 1963) low-density parity check (LDPC) codes. We propose a systematic approach to construct an approximate upper triangular GLD parity check matrix which defines a class of efficient-encoding GLD codes. It is shown that such GLD codes have equally good performance. By effectively exploiting structure sharing in the encoding process, we also present a hardware/software codesign for practical encoder implementation of these efficient-encoding GLD codes.
An experimental live chimeric porcine circovirus 1-2a vaccine decreases porcine circovirus 2b viremia when administered intramuscularly or orally in a porcine circovirus 2b and porcine reproductive and respiratory syndrome virus dual-challenge model (2011)

Commercially available inactivated vaccines against porcine circovirus type 2 (PCV2) have been shown to be effective in reducing PCV2 viremia. Live-attenuated, orally administered vaccines are widely used in the swine industry for several pathogens because of their ease of use yet they are not currently available for PCV2 and efficacy. The aims of this study were to determine the efficacy of a live-attenuated chimeric PCV2 vaccine in a dual-challenge model using PCV2b and porcine reproductive and respiratory syndrome virus (PRRSV) and to compare intramuscular (IM) and oral (PO) routes of vaccination. Eighty-three 2-week-old pigs were randomized into 12 treatment groups: four vaccinated IM, four vaccinated PO and four non-vaccinated (control) groups. Vaccination was performed at 3 weeks of age using a PCV1-2a live-attenuated vaccine followed by no challenge, or challenge with PCV2b, PRRSV or a combination of PCV2b and PRRSV at 7 weeks of age. IM administration of the vaccine elicited an anti-PCV2 antibody response between 14 and 28 days post vaccination, 21/28 of the pigs being seropositive prior to challenge. In contrast, the anti-PCV2 antibody response in PO vaccinated pigs was delayed, only 1/27 of the pigs being seropositive at challenge. At 21 days post challenge, PCV2 DNA loads were reduced by 80.4% in the IM vaccinated groups and by 29.6% in the PO vaccinated groups. PCV1-2a (vaccine) viremia was not identified in any of the pigs. Under the conditions of this study, the live attenuated PCV1-2a vaccine was safe and provided immune protection resulting in reduction of viremia. The IM route provided the most effective protection.
Ultrasound Images of Small Tissue Structures Free of Speckle (2006)

We suggest an alternative to the conventional pulse-echo method for analyzing ultrasound reflections to image small tissue structures. The images captured by our method prove to have improved resolution and are free of speckle. The method applies to a tissue structure that can be regarded as a layered medium on the scale of a few millimeters and is not too weakly reflecting. In both methods the incident pulse is made to be as nearly impulsive as possible. The pulse-echo method then rectifies the reflected pulse to create an image of the reflectivity distribution of the target convolved with the incident pulse. Instead of this, our method analyzes the incident and reflected pulses to produce an image of the acoustic impedance distribution of the target. A comparison of the two methods is shown in Fig. 1 where the target is three plastic films suspended in water. This phantom is insonified with 3.5 MHz ultrasound. The impedance image is seen to be much superior to the convolved reflectivity image. In Fig. 2 we compare a 20 MHz convolved reflectivity image with the 3.5 MHz impedance image. Although the 20 MHz reflectivity is much improved, it still does not match the 3.5 MHz impedance image. Next in Fig. 3 we compare the images the two methods provide of a human aorta wall speciman from the reflection of 3.5 MHz ultrasound. The impedance image is free of the speckle that appears in the reflectivity image. In Fig. 4 the impedance image is
Hydrogen sulfide (H<sub>2</sub>S) releasing agents: chemistry and biological applications (2014)

Hydrogen sulfide (H2S) is a newly recognized signaling molecule with very potent cytoprotective actions. The fields of H2S physiology and pharmacology have been rapidly growing in recent years, but a number of fundamental issues must be addressed to advance our understanding of the biology and clinical potential of H2S in the future. Hydrogen sulfide releasing agents (also known as H2S donors) have been widely used in these fields. These compounds are not only useful research tools, but also potential therapeutic agents. It is therefore important to study the chemistry and pharmacology of exogenous H2S and to be aware of the limitations associated with the choice of donors used to generate H2S in vitro and in vivo. In this review we summarized the developments and limitations of currently available donors including H2S gas, sulfide salts, garlic-derived sulfur compounds, Lawesson's reagent/analogs, 1,2-dithiole-3-thiones, thiol-activated donors, photo-caged donors, and thioamino acids. Some biological applications of these donors were also discussed.