gebhart/patrepeval huggingface dataset:
Resonance Raman View of Pericyclic Photochemical Ring-Opening Reactions: Beyond the Woodward-Hoffmann Rules (1995)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTResonance Raman View of Pericyclic Photochemical Ring-Opening Reactions: Beyond the Woodward-Hoffmann RulesMary K. Lawless, Steven D. Wickham, and Richard A. MathiesCite this: Acc. Chem. Res. 1995, 28, 12, 493–502Publication Date (Print):December 1, 1995Publication History Published online1 May 2002Published inissue 1 December 1995https://pubs.acs.org/doi/10.1021/ar00060a005https://doi.org/10.1021/ar00060a005research-articleACS PublicationsRequest reuse permissionsArticle Views405Altmetric-Citations51LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
ChemInform Abstract: A General and Versatile Synthesis of 2‐Alkyl‐4‐aminopyridines. (2001)

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.
Association between resistance to erythropoiesis‐stimulating agents and carnitine profile in patients on maintenance haemodialysis (2017)

ERI positively correlated with long-chain C18 acylcarnitine and negatively correlated with short-chain C5-OH acylcarnitine. C5-OH and C18 acylcarnitines at baseline might be contributing factors in distinguishing responders from nonresponders after L-carnitine administration.
Catalytic distillation in structured packings: Methyl acetate synthesis (2001)

Abstract Catalytic Distillation can improve process design, the design of column internals requires special attention. The catalytic packing MULTIPAK facilitates effective catalysis, high separation efficiency, and a wide loading range simultaneously. In this work the main characteristics of MULTIPAK—pressure drop, loading range, and separation efficiency—are determined experimentally. The developed nonequilibrium stage model developed reflects the complexity of catalytic distillation processes and comprises correlations describing pressure drop and separation efficiency of MULTIPAK as a function of the operating conditions. The model has been implemented in the simulation environment Aspen Custom Modeler, and the simulation results are compared with experimental data for the synthesis of methyl acetate. This model reflects the process behavior, but differences between simulated results and experimental data can still be observed.
Comprehensive evaluation of three-phase ac-ac PWM converter systems (2010)

Three-phase ac-ac PWM converters with voltage or current dc-link are employed for electric drives requiring bidirectional power flow and a high input power factor. For more than thirty years matrix converters have been considered to offer significant advantages over the conventional two-stage concepts with dc-link energy storage in terms of power conversion efficiency and volume of passive components. However, despite intensive research, matrix converters are still not widely used in industry. One possible reason for their limited utilization is the complex modulation scheme required to perform rectification and inversion simultaneously in one stage. The main objective of this Tutorial is to introduce the participant to matrix converters as well as voltage and current dc-link based converter systems in a figurative and easy-to-follow way. Starting from the voltage dc-link and current dc-link converter topology, various matrix converter topologies are derived and the related modulation and commutation schemes are introduced. Subsequently, the matrix converter concept is compared for drive applications against competing converter topologies with dc-link energy storage regarding efficiency, admissible torque-speed operating range, volume of passive components, and EMI filtering effort. Furthermore, a semiconductor chip area based assessment of the different converter concepts is given, which provides a further distinct criterion for comparison. The scope of the Tutorial not only includes bidirectional converters but also converter topologies with unidirectional power flow, which allow to reduce the number of power semiconductors and to decrease the overall realization effort and volume. The Tutorial aims at providing the participants with different figures-of-merit to select the most suitable converter concept for a given application and to assess the influence of future advancements in power semiconductor technology regarding performance gain of converter systems.
Cupric Ions Selectively Modulate TRAAK–Phosphatidylserine Interactions (2022)

TRAAK and TREK2 are two-pore domain K<sup>+</sup> (K2P) channels and are modulated by diverse factors including temperature, membrane stretching, and lipids, such as phosphatidic acid. In addition, copper and zinc, both of which are essential for life, are known to regulate TREK2 and a number of other ion channels. However, the role of ions in the association of lipids with integral membrane proteins is poorly understood. Here, we discover cupric ions selectively modulate the binding of phosphatidylserine (PS) to TRAAK but not TREK2. Other divalent cations (Ca<sup>2+</sup>, Mg<sup>2+</sup>, and Zn<sup>2+</sup>) bind both channels but have no impact on binding PS and other lipids. Additionally, TRAAK binds more avidly to Cu<sup>2+</sup> and Zn<sup>2+</sup> than TREK2. In the presence of Cu<sup>2+</sup>, TRAAK binds similarly to PS with different acyl chains, indicating a crucial role of the serine headgroup in coordinating Cu<sup>2+</sup>. High-resolution native mass spectrometry (MS) enables the determination of equilibrium binding constants for distinct Cu<sup>2+</sup>-bound stoichiometries and uncovered the highest coupling factor corresponds to a 1:1 PS-to-Cu<sup>2+</sup> ratio. Interestingly, the next three highest coupling factors had a ∼1.5:1 PS-to-Cu<sup>2+</sup> ratio. Our findings bring forth the role of cupric ions as an essential cofactor in selective TRAAK-PS interactions.
Biological Threat Detection via Host Gene Expression Profiling (2003)

With the increased threat posed by biological weapons, detection techniques for biothreat pathogens are critically needed to monitor and assess the severity of the illness once exposure has occurred. Current approaches for detecting biological threats are either time-consuming or highly specific but provide little information regarding pathogenicity. Genotyping of pathogens by PCR provides a fast and definitive means for identifying pathogens, but reliance on pathogen genotypic endpoints has several limitations. Current progress in DNA microarrays technology provides an alternative way to address the issues faced by traditional detection systems through host gene expression profiles of peripheral blood cells. We discuss the advantages and critical issues facing the use of host gene expression profiling for biological threat detection.
Node Protection for SR-TE Paths (2020)

Segment routing supports the creation of explicit paths using
adjacency-sids, node-sids, and binding-sids. It is important to
provide fast reroute (FRR) mechanisms to respond to failures of links
and nodes in the Segment-Routed Traffic-Engineered(SR-TE) path. A
point of local repair (PLR) can provide FRR protection against the
failure of a link in an SR-TE path by examining only the first (top)
label in the SR label stack. In order to protect against the failure
of a node, a PLR may need to examine the second label in the stack as
well in order to determine SR-TE path beyond the failed node. This
document specifies how a PLR can use the first and second label in the
label stack describing an SR-TE path to provide protection against
node failures.
Ribonucleotide reductase in the archaeon Pyrococcus furiosus : A critical enzyme in the evolution of DNA genomes? (1997)

Ribonucleotide reductase (RNR), the enzyme responsible for deoxyribonucleotide synthesis, has been isolated from Pyrococcus furiosus, a deeply branching hyperthermophilic, strictly anaerobic archaeon. Its gene has been cloned, sequenced, and shown to harbor two insertions encoding inteins. The purified enzyme absolutely requires adenosylcobalamin for activity, a trait that defines it as a member of class II (adenosyl-cobalamin-dependent) prokaryotic RNRs. On the other hand, the archaeal RNR has significant amino acid sequence homology with class I (aerobic non-heme iron-dependent) and class III (anaerobic iron-sulfur-dependent) RNRs present in eukaryotes and bacteria, respectively. It is proposed that this enzyme may be the closest possible relative of the original RNR, which allowed the key "RNA world" to "DNA world" transition, and that the different classes of present-day RNRs are the products of divergent evolution.
New Developments in Planar Array Infrared Spectroscopy (2005)

A planar array infrared (PA-IR) spectrograph offers several advantages over other infrared approaches, including high acquisition rate and sensitivity. However, it suffers from some important drawbacks, such as a limited spectral range and a significant curvature of the recorded spectral images, which still need to be addressed. In this article, we present new developments in PA-IR spectroscopy that overcome these drawbacks. First, a data processing method for the correction of the curvature observed in the spectral images has been developed and refined. In addition, a dual-beam instrument that allows the simultaneous recording of two independent spectral images has been developed. These two improvements have been combined to demonstrate the real-time background correction capability of PA-IR instruments. Finally, the accessible spectral range of the PA-IR spectrograph has been extended to cover simultaneously the methylene stretching (3200-2800 cm(-1)) and the finger-print (2000-1000 cm(-1)) spectral regions.
Bloch oscillations of a free electron in a strong field (2018)

We find that electrons in strong electromagnetic fields exhibit Bloch oscillations, in analogy to light propagation in index-gradient waveguide arrays. Our relativistic non-perturbative approach generalizes to multifrequency fields, producing rich variety of oscillations.
Recent developments in polyimide adhesives at NASA-Langley Research Center (1981)

Adhesive development is directed towards elevated temperature applications (200-300 C). Because of thermal stability considerations, the most attractive adhesives for this temperature range are linear and addition polyimides. The linear polymide adhesive research encompassed basic structure-property relationships, solvent studies and formulations to meet various requirements. The most recent research in linear polyimide systems was in the development of thermoplastic systems in an effort to eliminate the undesirable evolution of water classically associated with the cure going through an amide-acid intermediate step in the cure process. Addition polyimide adhesive research was undertaken in order to avoid water evolution during cure. Basic structure-property relationships for these materials led to an adhesive which was used extensively for high temperature adhesive needs. Since addition systems are of a highly crosslinked nature, they are not as resistant to impact as their linear counterparts. In order to overcome this problem, research was done in the area of elastomer-toughening these polymers.
Eurospeech, RESPITE and THISL (1999)

Report from the 1999 European Conference on Speech Communication and Technology (EUROSPEECH) and meetings of the Recognition of Speech by Partial Information Techniques (RESPITE) and Thematic Indexing of Spoken Language (THISL) projects.
Detection and Discrimination Methods of Sub-ppm Nitrogen Dioxide (NO2) with a Copper Oxide Sensor Operated with a Pulsed Temperature Modulation (2018)

International audience
Experimental demonstration of the "apparent wavelength" (1995)

In this paper, an experimental demonstration of the apparent using microwaves incident on a plane conductive surface obliquely, with the electric field polarization parallel to a reflecting plane, is presented. Standing wave measurements were obtained by utilizing the interaction between the transmitting and the receiving rectangular horn antennas using the receiving horn antenna as a probe. This technique demonstrates to the students that the wavelength along the normal, the apparent is longer than the wavelength of the free-space incident or reflected waves and is in agreement with the theory. Finally, the proposed technique demonstrates high sensitivity and accuracy for tutorial demonstrations of standing wave pattern measurements despite the large cross-section of the receiving antenna. >
Hybrid solar collector using nonimaging optics and photovoltaic components (2015)

The project team of University of California at Merced (UC-M), Gas Technology Institute, and Dr. Eli Yablonovitch of University of California at Berkeley developed a novel hybrid concentrated solar photovoltaic thermal (PV/T) collector using nonimaging optics and world record single-junction Gallium arsenide (GaAs) PV components integrated with particle laden gas as thermal transfer and storage media, to simultaneously generate electricity and high temperature dispatchable heat. The collector transforms a parabolic trough, commonly used in CSP plants, into an integrated spectrum-splitting device. This places a spectrum-sensitive topping element on a secondary reflector that is registered to the thermal collection loop. The secondary reflector transmits higher energy photons for PV topping while diverting the remaining lower energy photons to the thermal media, achieving temperatures of around 400°C even under partial utilization of the solar spectrum. The collector uses the spectral selectivity property of Gallium arsenide (GaAs) cells to maximize the exergy output of the system, resulting in an estimated exergy efficiency of 48%. The thermal media is composed of fine particles of high melting point material in an inert gas that increases heat transfer and effectively stores excess heat in hot particles for later on-demand use.
Low-Cost FC Stack Concept with Increased Power Density and Simplified Configuration Utilizing an Advanced MEA (2011)

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;In 2006, Nissan began limited leasing of the X-TRAIL FCV equipped with their in-house developed Fuel Cell (FC) stack. Since then, the FC stack has been improved in cost, size, durability and cold start-up capability with the aim of promoting full-scale commercialization of FCVs. However, reduction of cost and size has remained a significant challenge because limited mass transport through the membrane electrode assembly (MEA) has made it difficult to increase the rated current density of the FC. Furthermore, it has been difficult to reduce the variety of FC stack components due to the complex stack configuration.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;In this study, improvements have been achieved mainly by adopting an advanced MEA to overcome these difficulties. First, the adoption of a new MEA and separators has improved mass transport through the MEA for increased rated current density. Second, an integrated molded frame (IMF) has been adopted as the MEA support. One advantage of the IMF is its simplified structure and production process, reducing the MEA cost. Another advantage of the IMF is that it allows the FC stack enclosure to be eliminated because the layered IMFs form insulating side walls around the FC stack. Third, the FC stack configuration has been simplified by eliminating components or using alternative ones and adopting a “single-row” stack structure.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;As a result, the power density of the new FC stack has been increased to 2.5 kW/L, which is 30% higher than that of the previous 2008 model FC stack. It is estimated that the mass production cost of the new FC stack can be halved to nearly meet the target of the DOE Hydrogen Program. With further improvements such as higher current density and lower catalyst loading, FCVs will be compact and affordable enough for ordinary consumers at the full-scale commercial stage.&lt;/div&gt;&lt;/div&gt;
Investigation of the Safety Effects of Knee Bolster Air Bag Deployment in Similar Real-World Crash Comparisons (2013)

The current study presents a preliminary in-depth qualitative and quantitative assessment of KBAB safety benefits. However, further investigation is recommended to provide conclusive evidence of KBAB effectiveness.
Hollow Cathode and Keeper-Region Plasma Measurements Using Ultra-Fast Miniature Scanning Probes (2004)

In order to support the development of comprehensive performance and life models for future deep space missions that will utilize ion thrusters, we have undertaken a study of the plasma structure in hollow cathodes using an new pneumatic scanning probe diagnostic. This device is designed to insert a miniature probe directly into the hollow cathode orifice from either the upstream insert region in the interior of the hollow cathode, or from the downstream keeper-plasma region at the exit of the hollow cathode, to provide complete axial profiles of the discharge plasma parameters. Previous attempts to diagnose this region with probes was Limited by the melting of small probes in the intense discharge near the orifice, or caused significant perturbation of the plasma by probes large enough to survive. Our new probe is extremely compact, and when configured as a single Langmuir probe, the ceramic tube insulator is only 0.5mm in diameter and the current collecting conductor has a total area of 0.002 cm2. A series of current-voltage characteristics are obtained by applying a rapid sawtooth voltage waveform to the probe as it is scanned by the pneumatic actuator into and out of the plasma region, The bellow-sealed pneumatic drive scans the probe 4 cm in the cathode insert region and 10 cm in the anode/keeper plasmas region at average speeds of about 1 mm/msec, and the residence time at the end of the insertion stroke in the densest part of the plasma near the orifice is measured to be only 10 msec. Since the voltage sweep time is fast compared to the motion of the probe, axial profiles of the plasma density, temperature and potential with reasonable spatial resolution are obtained. Measurements of the internal cathode pressures and the axial plasma-parameter profiles for a hollow cathode operating at discharge currents of up to 35 A in xenon will be presented.
Coxsackie B4 virus infection of β cells and natural killer cell insulitis in recent-onset type 1 diabetic patients (2007)

Type 1 diabetes is characterized by T cell-mediated autoimmune destruction of pancreatic beta cells. Several studies have suggested an association between Coxsackie enterovirus seroconversion and onset of disease. However, a direct link between beta cell viral infection and islet inflammation has not been established. We analyzed pancreatic tissue from six type 1 diabetic and 26 control organ donors. Immunohistochemical, electron microscopy, whole-genome ex vivo nucleotide sequencing, cell culture, and immunological studies demonstrated Coxsackie B4 enterovirus in specimens from three of the six diabetic patients. Infection was specific of beta cells, which showed nondestructive islet inflammation mediated mainly by natural killer cells. Islets from enterovirus-positive samples displayed reduced insulin secretion in response to glucose and other secretagogues. In addition, virus extracted from positive islets was able to infect beta cells from human islets of nondiabetic donors, causing viral inclusions and signs of pyknosis. None of the control organ donors showed signs of viral infection. These studies provide direct evidence that enterovirus can infect beta cells in patients with type 1 diabetes and that infection is associated with inflammation and functional impairment.
<title>DETERMINANTS AND INDICES OF FOCAL SPOT PERFORMANCE-THE CONCEPT OF THREE-DIMENSIONALITY.</title> (1974)

Determinants of performance: There are four major factors which affect the imaging performance of a focal spot. I. Size. Intensity distribution. III . Shape. IV. Off-focus irradiation.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Age-Dependent TLR3 Expression of the Intestinal Epithelium Contributes to Rotavirus Susceptibility (2012)

Rotavirus is a major cause of diarrhea worldwide and exhibits a pronounced small intestinal epithelial cell (IEC) tropism. Both human infants and neonatal mice are highly susceptible, whereas adult individuals remain asymptomatic and shed only low numbers of viral particles. Here we investigated age-dependent mechanisms of the intestinal epithelial innate immune response to rotavirus infection in an oral mouse infection model. Expression of the innate immune receptor for viral dsRNA, Toll-like receptor (Tlr) 3 was low in the epithelium of suckling mice but strongly increased during the postnatal period inversely correlating with rotavirus susceptibility, viral shedding and histological damage. Adult mice deficient in Tlr3 (Tlr3(-/-)) or the adaptor molecule Trif (Trif(Lps2/Lps2)) exerted significantly higher viral shedding and decreased epithelial expression of proinflammatory and antiviral genes as compared to wild-type animals. In contrast, neonatal mice deficient in Tlr3 or Trif did not display impaired cell stimulation or enhanced rotavirus susceptibility. Using chimeric mice, a major contribution of the non-hematopoietic cell compartment in the Trif-mediated antiviral host response was detected in adult animals. Finally, a significant age-dependent increase of TLR3 expression was also detected in human small intestinal biopsies. Thus, upregulation of epithelial TLR3 expression during infancy might contribute to the age-dependent susceptibility to rotavirus infection.
Guillain‐Barré syndrome and COVID‐19: A 1‐year observational multicenter study (2022)

Other than showing an increase of GBS in northern Italy in the "COVID-19 era" compared to the previous year, this study emphasizes how GBS cases related to COVID-19 represent a significant part of the total, thus suggesting a relation between COVID-19 and GBS.