gebhart/patrepeval huggingface dataset:
Rationalizing the Effect of Triethylaluminum on the Cr/SiO2Phillips Catalysts (2020)

In contrast to most of the other olefin polymerization catalysts, the Cr/SiO2 Phillips catalyst does not need any activator to develop its activity. However, it is known that the addition of a small amount of metal-alkyls has drastic effects on the catalyst performance, and it is one of the strategies adopted in industrial practice to tailor the properties of the polyethylene produced. In this work, we conducted a systematic investigation on the effect of triethylaluminum on the Cr(VI)/SiO2 catalyst, with the ultimate goal to determine the properties of the Cr sites at a molecular level and to correlate them to the properties of the obtained polyethylene. To this aim, we coupled kinetic tests, spectroscopic methods (diffuse reflectance UV–vis–near-infrared, electron paramagnetic resonance, Fourier-transform infrared spectroscopy of probe molecules), and different polymer characterization techniques. We found that, at an Al/Cr ratio of 2:1, only ca. 50% of the original Cr(VI) sites are reduced to a variety of species comprising: (1) Cr(IV) bisalkyl sites, which are probed by carbon monoxide and are the major actors in the polymerization of ethylene, explaining the faster polymerization initiation rate; (2) 6-fold coordinated Cr(III) sites, which are not accessible by probes and whose amount does not correlate with the catalyst activity; and (3) two types of monografted Cr(II) sites, all deriving from the over-reduction of the Cr(IV) bisalkyl sites, having, respectively, weak and strong Lewis acid characters, the former responsible for in situ α-olefin generation (and hence contributing to the enchainment of short polymer branching) and the latter accounting for the formation of the high-molecular-weight polymer fraction. Overall, our results demonstrate that the catalytic performance of the Cr sites depends not only on the oxidation state but rather on a combination of molecular structure, acidic character, and nature of the ancillary ligands. Hence, by tuning the structure and acidity of the Cr sites, it is possible to move from a system that essentially affords oligomers from ethylene to one that affords high-molecular-weight polymers.
(Invited) Electrochemical Atomic Layer Deposition: Metal Deposition One Atomic Layer at a Time Enabled By Potential Pulsing & Self-Limiting Growth (2017)

Many important technological applications, including nano-electronics, photovoltaics and electrocatalysis, critically depend on the ability to fabricate materials with precise, atomic-level control over structure and properties. Traditionally, fabrication of atomic-scale materials has been achieved through vapor-phase atomic layer deposition (ALD); however, this process has several drawbacks such as the use of unstable precursors which decompose yielding contaminated deposits. An alternative approach, using liquid-phase precursors and electrode potential manipulation, termed electrochemical atomic layer deposition (e-ALD), allows atomic-scale deposition of metals such as copper (Cu) and cobalt (Co). In this approach, underpotential deposition first forms a monolayer of a sacrificial metal such as zinc (Zn). The Zn adlayer then undergoes spontaneous surface-limited redox replacement by a nobler metal such as Cu or Co. This sequence is repeated to build multi-layered metal deposits one atomic layer at a time. Unlike vapor-phase ALD, e-ALD does not use unstable precursors and thus provides high-purity deposits. Prior e-ALD formulations have used toxic chemicals and necessitated frequent electrolyte switching; however, our e-ALD approach uses benign chemicals and eliminates electrolyte switching through the use of optimized potential pulsing sequences. This talk will highlight advantages of our e-ALD approach for applications in nano-fabrication and semiconductor interconnect metallization.
The centrosome and the mechanism of microtubule nucleation (2006)

Microtubules are hollow polymers of α β‐tubulin that exhibit GTP‐dependent assembly dynamics and comprise a critical part of the eukaryotic cytoskeleton. Initiation of new microtubules in vivo requires γ‐tubulin, organized as an oligomer within the γ‐Tubulin Ring Complex (γ‐TuRC) of higher eukaryotes. Structural insight into γ‐tubulin, its oligomerization, and how it promotes microtubule assembly remains lacking. We have determined the 2.7Å crystal structure of human γ‐tubulin bound to GTPγ S. Unexpectedly, γ‐tubulin:GTPγ S adopts a curved conformation very similar to that seen in GDP‐bound microtubule depolymerization products. This suggests that, unlike signaling GTPases, tubulins may not undergo nucleotide‐dependent conformational switching. We support this with recent SAXS data and conformationally‐sensitive binding experiments. Together, these results have important implications for α β‐tubulin assembly; in particular, they suggest that there are unanticipated barriers to de novo microtubule assembly. We propose a model for microtubule assembly in which guanine nucleotides do not regulate curved‐to‐straight transitions, but instead serve to modulate the strength of longitudinal interactions within the microtubule lattice. To gain structural and functional sights into the mechanism of nucleation, we are using cryo electron microscopic tomography to directly visualize them at the minus ends of microtubules within intact frozen hydrated centrosomes at about 5nm resolution. In an effort to better define the nucleation site, we have developed software designed to find, align and average the minus end density, with a goal of reaching 2.5nm resolution. Our current reconstructions clearly show the γ‐TuRC cap and also reveal the fibrous nature of the pericentriolar material (PCM). Using isolated γ TuRCs and similar reconstruction approaches, we are working towards a 2.5nm reconstruction revealing the lock washer shape of the γ TuRC, likely made up from the lateral association of γ –tubulin small complexes (γ TuSC) and the existence of an additional cap structure that may act to stabilize the ring of γ TuSCs.
Model for cw laser collisionally induced fluorescence in low-temperature discharges (2000)

A perturbed steady-state rate-equation model has been developed for the cw laser collisionally induced fluorescence (LCIF) produced by excitation on one of the 1s-2p noble gas transitions. This work is one part of a wider complementary modeling program which includes cw optogalvanic spectroscopy, optical emission spectroscopy, and optical absorption spectroscopy, with the overall aim of testing all of these models with the same stringently assembled atomic and discharge data set. Our aim here is to demonstrate the principal features of our cw LCIF model by using it to describe our experimental observations produced by pumping transitions originating on the 1s(5) metastable and 1s(4) resonance states of neon atoms in the positive column of a normal glow discharge at 2.0 Torr and a discharge current of 5 mA. The model shows that these cw LCIF spectra are dominated by 1s-2p excitation and electron collisional coupling among the 2p states. We show that the model allows us to quantify explicitly the various individual contributions to each line in the cw LCIF spectra. The theory and analyses presented here apply equally well to other noble gases and we believe can be modified appropriately for trace noble gases in atomic-molecular mixtures.
`NuMex Sunrise', `NuMex Sunset', and `NuMex Eclipse' Ornamental Chile Peppers (1990)

Fig. 1. Mature fruits of ‘NuMex Eclipse’, ‘NuMex Sunrise’, ‘NuMex Sunset’, and ‘NuMex R Naky’. The New Mexico Agricultural Experiment Station announces the release of ‘NuMex Sunrise’, ‘NuMex Sunset’, and ‘NuMex Eclipse’, New Mexican-type ornamental chile peppers (Capsicum annuum L.). They are unique in providing alternative mature fruit color in chile peppers. Mature fruits of ‘NuMex Sunrise’, ‘NuMex Sunset’, and ‘NuMex Eclipse’ are yellow, orange, and brown, respectively. The main use for these cultivars will be as ornamental chile peppers. New Mexicans have traditionally harvested and strung mature red chile peppers into colorful strings or ristras. The ristra is hung near the entrance of the house as a symbol of hospitality. Only pepper types that dehydrate sufficiently to eliminate rotting can be used to make ristras (Sais, 1984). Consequently, pepper types like yellow wax, jalapeno, or bell are not suitable for ristras, because they rot before they dry. Decorations, such as wreaths, made with chile peppers that can be dehydrated are popular in the southwestern United States, and are an important tourist product. Ornamental peppers have become increasingly important as an alternative crop for small farmers. ‘NuMex Sunrise’, ‘NuMex Sunset’, and ‘NuMex Eclipse’ were developed upon request of the New Mexico chile pepper producers.
Cyclization of Peptides by using Selenolanthionine Bridges (2012)

Selenocysteine does the job: Lanthionine bridges are important structural elements in naturally occurring lantibiotics. They can be engineered into peptides to increase biological activity and metabolic stability. Macrocyclization of peptides by intramolecular thiolation of cysteine is often difficult but can be achieved by replacing cysteine with the more reactive isosteric selenocysteine amino acid.
Tailoring microstructures of materials through biomimetics (1993)

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications. Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging. In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.
Causal inference in longitudinal studies with history-restricted marginal structural models (2007)

A new class of Marginal Structural Models (MSMs), History-Restricted MSMs (HRMSMs), was recently introduced for longitudinal data for the purpose of defining causal parameters which may often be better suited for public health research or at least more practicable than MSMs (6, 2). HRMSMs allow investigators to analyze the causal effect of a treatment on an outcome based on a fixed, shorter and user-specified history of exposure compared to MSMs. By default, the latter represent the treatment causal effect of interest based on a treatment history defined by the treatments assigned between the study's start and outcome collection. We lay out in this article the formal statistical framework behind HRMSMs. Beyond allowing a more flexible causal analysis, HRMSMs improve computational tractability and mitigate statistical power concerns when designing longitudinal studies. We also develop three consistent estimators of HRMSM parameters under sufficient model assumptions: the Inverse Probability of Treatment Weighted (IPTW), G-computation and Double Robust (DR) estimators. In addition, we show that the assumptions commonly adopted for identification and consistent estimation of MSM parameters (existence of counterfactuals, consistency, time-ordering and sequential randomization assumptions) also lead to identification and consistent estimation of HRMSM parameters.
Glucose modulates transcription factor dimerization to enable tissue differentiation (2022)

Glucose is a universal energy currency for living organisms, however, its non-energetic functions in processes such as differentiation are undefined. In epidermis, differentiating cells exhibit dynamic changes in gene expression 1–4 driven by specific transcription factors (TFs) 5–9 . The interplay between such TFs and biomolecules that also change in this process is not understood. Metabolomic analyses revealed that increased intracellular glucose accompanies differentiation of epidermal keratinocytes. This elevation also occurred in differentiating cells from other tissues and was verified in epidermal tissue engineered with glucose sensors, which detected a glucose gradient that peaked in the outermost differentiated layers. Free glucose accumulation, unaccompanied by its increased metabolism, was essential for epidermal differentiation and required GLUT1, GLUT3, and SGLT1 transporters. Glucose affinity chromatography and azido-glucose click chemistry uncovered glucose binding to diverse regulatory proteins, including the IRF6 TF, whose epidermal knockout confirmed its requirement in glucose-dependent differentiation. Direct glucose binding enabled IRF6 dimerization, DNA binding, genomic localization, and induction of IRF6 target genes, including essential pro-differentiation TFs GRHL1, GRHL3, HOPX and PRDM1 . The IRF6 R84C mutant found in undifferentiated cancers was unable to bind glucose. These data identify a new role for glucose as a gradient morphogen that modulates protein multimerization in cellular differentiation.
<title>Object recognition using appearance representations derived from solid models of objects</title> (1998)

We advance active computer vision algorithms for flexible manufacturing systems that classify objects and estimate their pose from intensity images. Our algorithms automatically reposition the sensor if the class or pose of an object is ambiguous in a given image and incorporate data from multiple object views in determining the final object classification. A feature space trajectory (FST) in a global eigenfeature space is used to represent 3-D distorted views of an object. Bayesian methods are used to derive the class hypothesis, pose estimate, confidence measures, and the sensor position that best resolves ambiguity. FSTs constructed using images rendered from solid models of objects are used to process real image data.
A Uniform Approach to Processing Temporal Queries (1992)

dayalQcrl.dec.com Research in temporal databases has mainly focused on defining temporal data models by extending existing mod-els, and developing access structures for temporal data. Little has been done on temporal query processing and optimization. In this paper, we propose a uniform frame-work for processing temporal queries, which builds upon well-understood techniques for processing non-temporal queries. We start with an object-oriented model, and rely on its rich type system to model complex temporal infor-mation. The same query language is used to express tem-poral and non-temporal queries uniformly. A major benefit to this approach is that temporal query processing can be smoothly extended from an existing (non-temporal) query processing framework. For the purpose of query process-ing, we describe an object algebra, into which queries are compiled. Since the object algebra resembles the relational algebra, familiar relational query optimization techniques can be used. However, since the physical representation of temporal data and access methods differ from those of non-temporal data, new algorithms must be developed to evalu-ate the algebraic operators. We demonstrate that temporal queries can be processed and optimized under the existing query processing framework. 1
ChemInform Abstract: Asymmetric Synthesis and anti‐HIV Activity of L‐Carbocyclic 2′,3′‐Didehydro‐2′,3′‐dideoxyadenosine. (1998)

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.
Toxicity Modulation, Resistance Enzyme Evasion, and A-Site X-ray Structure of Broad-Spectrum Antibacterial Neomycin Analogs (2014)

Aminoglycoside antibiotics are pseudosaccharides decorated with ammonium groups that are critical for their potent broad-spectrum antibacterial activity. Despite over three decades of speculation whether or not modulation of pKa is a viable strategy to curtail aminoglycoside kidney toxicity, there is a lack of methods to systematically probe amine-RNA interactions and resultant cytotoxicity trends. This study reports the first series of potent aminoglycoside antibiotics harboring fluorinated N1-hydroxyaminobutyryl acyl (HABA) appendages for which fluorine-RNA contacts are revealed through an X-ray cocrystal structure within the RNA A-site. Cytotoxicity in kidney-derived cells was significantly reduced for the derivative featuring our novel β,β-difluoro-HABA group, which masks one net charge by lowering the pKa without compromising antibacterial potency. This novel side-chain assists in evasion of aminoglycoside-modifying enzymes, and it can be easily transferred to impart these properties onto any number of novel analogs.
Waveguides induced by photorefractive screening solitons (2002)

Summary form only given. Photorefractive spatial solitons form when the optically induced space-charge field modifies the refractive index via electro-optic effect and forms a waveguide that confines the optical beam that has induced the waveguide. Since the photorefractive response is wavelength dependent, one can generate a soliton with a weak beam and guide in it a more intense beam of a less photosensitive wavelength. Here we present theoretical and experimental studies of the waveguides induced by photorefractive screening solitons. We show that the number of guided modes in a waveguide induced by a bright screening soliton increases monotonically with increasing intensity ratio (the ratio between the peak soliton intensity and the background or dark irradiance), whereas the waveguides induced by dark screening solitons are always single-mode waveguides.
Highly Efficient Organic Blue‐and White‐Light‐Emitting Devices Having a Carrier‐ and Exciton‐Confining Structure for Reduced Efficiency Roll‐Off (2008)

Highly efficient blue and white OLEDs with reduced efficiency roll-off based on a carrier- and exciton-confining structure are developed. Record power efficiencies of 46 and 44 lm W−1 and an external quantum efficiency of 25% at the illumination-relevant luminance of 1000 cd m−2 are achieved for the blue and white OLEDs, respectively, without the use of any outcoupling techniques.
Digital Boltzmann VLSI for constraint satisfaction and learning (1993)

We built a high-speed, digital mean-field Boltzmann chip and SBus board for general problems in constraint satjsfaction and learning. Each chip has 32 neural processors and 4 weight update processors, supporting an arbitrary topology of up to 160 functional neurons. On-chip learning is at a theoretical maximum rate of 3.5 x 108 con-nection updates/sec; recall is 12000 patterns/sec for typical condi-tions. The chip&amp;apos;s high speed is due to parallel computation of inner products, limited (but adequate) precision for weights and activa-tions (5 bits), fast clock (125 MHz), and several design insights. Digital Boltzmann VLSI for Constraint Satisfaction and Learning 897 1
Antimicrobial treatment of nylon (2001)

Abstract The preparation of an antimicrobial nylon material and its properties are discussed. Biocidal cyclic N ‐chloramine moieties were covalently bonded to Nylon 66. These moieties, which included hydantoins, oxazolidinones, and imidazolidinones, were stable during at least 3 months of dry storage, and their antimicrobial activities, once lost by reaction with reducing sodium thiosulfate, could be regenerated by exposure to free chlorine. Biocidal swatch tests showed that the nylon fabrics containing N ‐chlorinated hydantoin functional groups provided a 7.2 log reduction of Staphylococcus aureus and a 7.1 log reduction of Escherichia coli at a contact time of only 10 min. Antimicrobial nylon should find a variety of important uses such as in clothing, carpets, sutures, brushes, and so forth. © 2001 John Wiley &amp; Sons, Inc. J Appl Polym Sci 81: 943–947, 2001
Bringing biological solutions to chemical problems (1998)

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
Multiple Antibody Lineages in One Donor Target the Glycan-V3 Supersite of the HIV-1 Envelope Glycoprotein and Display a Preference for Quaternary Binding (2016)

Broadly neutralizing antibodies targeting the HIV-1 glycan-V3 region with single lineages from individual donors have been described previously. Here we describe three lineages from a single donor, each of which targets glycan-V3. Unlike previously described glycan-V3 antibodies, these mature antibodies bind preferentially to the native Env trimer and weakly to the gp120 monomer. These data extend our knowledge of the immune response recognition of the N332 supersite region and suggest that the mode of epitope recognition is more complex than previously anticipated.
Results of the 2015 Scoliosis Research Society Survey on Single Versus Dual Attending Surgeon Approach for Adult Spinal Deformity Surgery (2017)

5.
URETHANE AND CONTRACTION OF VASCULAR SMOOTH MUSCLE (1979)

1 In vitro studies were undertaken on rat aortic strips and portal vein segments in order to determine whether or not the anaesthetic, urethane, can exert direct actions on vascular smooth muscle. 2 Urethane was found to inhibit development of spontaneous mechanical activity. This action took place with a urethane concentration as little as one tenth of that found in anaesthetic plasma concentratios, i.e., 10(-3) M. 3 Urethane (10(-3 to 10(-1) M) dose-dependently attenuated contractions induced by adrenaline, angiotensin and KCl. These inhibitory actions were observed with urethane added either before or after the induced contractions. 4 Ca2+-induced contractions of K+-depolarized aortae and portal veins were also attenuated, dose-dependently, by urethane. 5 All of these inhibitory effects were completely, and almost immediately, reversed upon washing out the anaesthetic from the organ baths. 6 A variety of pharmacological antagonists failed to mimic or affect the inhibitory effects induced by urethane. 7 These data suggest that plasma concentrations of urethane commonly associated with induction of surgical anaesthesia can induce, directly, relaxation of vascular muscle.
Implementation and evaluation of inverter loss modeling as part of DB-DTFC for loss minimization each switching period (2014)

This paper presents the experimental evaluation of a flux linkage-based inverter loss model embedded in a deadbeat-direct torque and flux control (DB-DTFC) that achieves desired torque and minimizes losses over each switching period. The optimal flux commands are selected from those that will achieve the desired torque by using embedded dynamic flux linkage-based loss models of the machine and inverter. The proposed inverter loss model is implemented in real-time on a flux weakening interior permanent magnet synchronous machine (FW-IPMSM) test bench and evaluated experimentally. The actual inverter losses are obtained by measuring the electrical power at three different points in the test bench. In order to evaluate the loss model, comparative evaluation of the actual inverter losses versus the estimated losses have been performed under both constant stator flux and dynamic flux trajectories. Finally, losses resulting from using different widely used loss minimizing control strategies are compared.