gebhart/patrepeval huggingface dataset:
Matrix isolation and transient absorption studies of [bis[bis(pentafluoroethyl)phosphino]ethane]tetracarbonylchromium: intermolecular alkane complexes and intramolecular F-coordination (1992)

Photolysis of (t;2-dfepe)Cr(CO)4 [dfepe = (C2F5)2PCH2CH2P(C2F5)2] has been conducted in rigid matrices at 12 K (Ar, CH4, N2, CO) and 30 K (Xe) and in alkane and perfluoroalkane solutions. In Ar, CH4, and Xe matrices a combination of IR and UV-vis spectroscopic data demonstrate photodissociation of the cis carbonyl ligand to generate/ac-(dfepe)Cr(CO)3L, where L is either the matrix host or an intramolecularly coordinated F atom donated by one of the pendant CF3CF2- groups of the dfepe ligand. Only traces of the mer isomer were observed. In nitrogen matrices there is evidence for formation of both fac- and wer-(dfepe)Cr(CO)3N2. Carbonyl stretching frequencies of the matrix-isolated photoproducts were measured and bonding force constants and ligand effect constants were calculated. In solution both the Cr-CO and Cr-P bonds are photolabile. Results of nanosecond and microsecond transient absorption spectroscopic experiments in hexane and cyclohexane solvents indicate formation of alkane complexes of the type (tj2-dfepe)Cr(CO)3(alkane) and (V-dfepe)Cr(CO)4(alkane), as well as formation of intramolecularly F-coordinated species Cr(CO)4(V-dfepe) and Cr(CO)3(r;2-dfepe). By use of transient absorption techniques, rates of reaction of these species in alkane solvents with and without added trapping ligands (CO, water, triethylsilane) have been measured. The F-coordinated species react with CO approximately 50 times faster than the alkane complexes. In experiments using (j)'-dfepe)Cr(CO)5, similar results have been obtained which support the interpretation of the behavior of (?i2-dfepe)Cr(CO)4. Products from 13CO trapping of the transients generated in hexane show that all four possible isomers, fac- and mer-(jj2-dfepe)Cr(CO)3*CO and cis- and tr<znj-(ijl-dfepe)Cr(CO)4*CO, are formed in significant quantities. Experiments carried out at a different l3CO pressures show that l3CO trapping of ci>(V-dfepe)Cr(CO)4(L) is competitive with ring closure back to (rj2-dfepe)Cr(CO)4.
Dispersion of Surface Modified Silica Nanoparticles into a Resin by Using a Twin Screw Extruder (2003)

Organic-inorganic nanocomposites have been made by hybridization of silica nanoparticles in a thermoplastic resin using a melt extrusion method. We found that uniform dispersion of nanoparticles in the resin can be attained by the treatment of nanoparticle surfaces with an organic compound and the modification of polystyrene resin prior to mixing as well as the optimization of screw design of a twin screw extruder. Since the domain size of silica nanoparticles in the resin is smaller than the wavelength of visible light, the obtained composites are transparent in visible region, which is important for industrial applications.
Continuous Scratch Testing on Core Allows Effective Calibration of Log-Derived Mechanical Properties for Use in Sanding Prediction Evaluation (2002)

Abstract This paper discusses the use of continuous scratch testing for evaluation of rock heterogeneity and effective correction and calibration of mechanical properties predictions using wire line logging. Understanding the vertical variability of rock properties (strength and moduli) along the reservoir thickness is of primordial importance for sanding prediction analysis. Logging measurements (GR, Sonic, Density and Porosity) are traditionally used to identify troublesome intervals, to select sections for laboratory testing and for extrapolating laboratory data to untested reservoir sections. However, depending on the scale of the reservoir heterogeneity, the log measurements, by providing integrated values over their window of vertical resolution, can considerably underestimate the strong reservoir sections and overestimate the weak reservoir sections. This leads to misrepresentation of critical weak layers with high potential for sanding and potentially to large errors in the completion strategy with costly long-term consequences. Corrections are thus necessary and are traditionally based on simple unconfined compression (UCS) tests conducted sparsely or at high density, varying from operator to operator. This paper presents a method for log-correction based on continuous core scratching in the laboratory and shows that the methodology is effective in evaluating changes in properties with high accuracy and a resolution of at least 1 cm.
Minor genomic differences between related B6 and B10 mice affect severity of schistosome infection by governing the mode of dendritic cell activation (2015)

Infection with the helminth Schistosoma mansoni results in hepatointestinal granulomatous inflammation mediated by CD4 T cells directed against parasite eggs. The severity of disease varies greatly in humans and mice; however, the genetic basis of such a heterogenous immune response remains poorly understood. Here we show that, despite their close genetic relationship, C57BL/10SnJ (B10) mice developed significantly more pronounced immunopathology and higher T helper 17 cell responses than C57BL/6J (B6) mice. Similarly, live egg-stimulated B10-derived dendritic cells (DCs) produced significantly more IL-1β and IL-23, resulting in higher IL-17 production by CD4 T cells. Gene expression analysis disclosed a heightened proinflammatory cytokine profile together with a strikingly lower expression of Ym1 in B10 versus B6 mice, consistent with failure of B10 DCs to attain alternative activation. To genetically dissect the differential response, we developed and analyzed congenic mouse strains that capture major regions of allelic variation, and found that the level of inflammation was controlled by a relatively small number of genes in a locus mapping to chromosome 4 117-143 MB. Our study has thus identified novel genomic regions that regulate the severity of the schistosome infection by way of controlling the mode of DC activation and consequent CD4 T-cell subset development.
Agostic Interactions in Transition Metal Compounds (2007)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Antigenic analysis of the HIV-1 envelope trimer implies small differences between structural states 1 and 2 (2022)

The conformationally dynamic HIV-1 envelope trimer (Env) is the target of broadly neutralizing antibodies (bnAbs) that block viral entry. Single-molecule Förster resonance energy transfer (smFRET) has revealed that HIV-1 Env exists in at least three conformational states on the virion. Prior to complete host-receptor engagement (State 3), Env resides most prevalently in the smFRET-defined State 1, which is preferentially recognized by most bnAbs that are elicited by natural infection. smFRET has also revealed that soluble trimers containing prefusion-stabilizing disulfide and isoleucine-to-proline substitutions reside primarily in State 2, which is a required intermediate between States 1 and 3. While high-resolution Env structures have been determined for States 2 and 3, the structure of these trimers in State 1 is unknown. To provide insight into the State 1 structure, here we characterized antigenic differences between smFRET-defined states and then correlated these differences with known structural differences between States 2 and 3. We found that cell surface-expressed Env was enriched in each state using state-enriching antibody fragments or small-molecule virus entry inhibitors and then assessed binding to HIV-1 bnAbs preferentially binding different states. We observed small but consistent differences in binding between Env enriched in States 1 and 2, and a more than 10-fold difference in binding to Env enriched in these states versus Env enriched in State 3. We conclude that structural differences between HIV-1 Env States 1 and 3 are likely more than 10-fold greater than those between States 1 and 2, providing important insight into State 1.
A 4.8pJ/b 56Gb/s ADC-Based PAM-4 Wireline Receiver Data-Path with Cyclic Prefix in 14nm FinFET (2019)

This work presents an ADC-based receiver (RX) data-path for frame-based PAM-4 modulation with a cyclic prefix (CP). Similar to discrete multi-tone (DMT) modulation, a frame of PAM-4 symbols are protected from the channel delay spread by the CP taps. A PAM-4 frame window including CP taps is viewed as a DMT symbol and is equalized similarly to a DMT signal equalization, based on a discrete-time Fourier transform (DFT) and frequency-domain equalizer (FDE). The RX prototype implemented in 14nm FinFET achieves 56Gb/s data-rate at less than 3e-5 pre-FEC BER over a 19dB loss channel at 14GHz dissipating 270mW including the ADC and the DSP data-path excluding the inverse DFT and the BER checker.
Fast partitioning strategies for VVC and their implementation in an Open Optimized Encoder (2021)

In July 2020 the new video coding standard Versatile Video Coding (VVC) was released. VVC delivers bitrate savings of up to 50% relative to its predecessor High Efficiency Video Coding (HEVC) without compromising subjective quality. It has been designed for a broad range of applications and input material ranging from standard dynamic range to high dynamic range camera-captured content, screen content, and immersive applications. One of the key technologies included in the new standard is the flexible block partitioning using a quad-tree with multi-type tree structures (QT+MTT). Based on the VVC test model VTM, the VVenC project provides an open optimized VVC encoder. VVenC inherits and utilizes all of VTMs in-built partitioning search strategies. The QT+MTT partitioning search still poses a challenge for fast encoder implementations. After defining alternative low-depth partitioning configurations to VTM, it was observed that the initial search algorithm performs less optimal. We analyze and propose in this paper a set of additional fast search strategies for partitioning within VVenC, optimized for low-depth partitioning configurations. As a result, an average of 38% runtime reduction is achieved at the managable cost of less than 2% BD-rate loss.
Finite precision processing in wireless applications (2009)

Complex signal processing algorithms are often specified in floating point precision. Thus, a type conversion is needed when the targeted platform requires fixed-point precision. In this work we proposed a new method to evaluate the final impact of finite precision processing in wireless applications. The latter combines analytical analysis with simulations. This extends previous work including the effect of the decision-making errors resulting from quantization. Thereby efficient dimensioning of the minimum bit-widths that satisfy a given accuracy constraint can be deployed. The method is validated with two representative case studies, namely an OFDM inner receiver and a Near-ML MIMO (Multiple Inputs, Multiple Outputs) detector.
Teneurin 2 is expressed by the neurons of the thalamofugal visual system in situ and promotes homophilic cell-cell adhesion in vitro (2002)

The transmembrane glycoprotein teneurin 2 is expressed by neurons in the developing avian thalamofugal visual system at periods that correspond with target recognition and synaptogenesis. Partial and full-length teneurin 2 constructs were expressed in cell lines in vitro. Expression of the cytoplasmic domain is required for the induction of filopodia, the transport of teneurin 2 into neurites and the co-localization of teneurin 2 with the cortical actin cytoskeleton. In addition, expression of the extracellular domain of teneurin 2 by HT1080 cells induced cell aggregation, and the extracellular domain of teneurin 2 became concentrated at sites of cell-cell contact in neuroblastoma cells. These observations indicate that the homophilic binding of teneurin 2 may play a role in the development of specific neuronal circuits in the developing visual system.
Five-Year, Prospective, Randomized, Multi-Surgeon Trial of Two Trabecular Bypass Stents versus Prostaglandin for Newly Diagnosed Open-Angle Glaucoma (2019)

This prospective randomized trial demonstrates 5-year effectiveness and safety of 2 trabecular bypass stents in patients with newly diagnosed, treatment-naive POAG, with comparably favorable outcomes as topical prostaglandin.
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance (2022)

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.
Detection of Peroxidase/H2O2-Mediated Oxidation with Enhanced Yellow Fluorescent Protein (2005)

The ability to sense oxidative stress in live cells and organisms would have far-reaching implications for biotechnology, drug discovery, and potentially medical imaging. We hypothesized that tyrosine-containing fluorescent proteins could be used as switches for sensing oxidative stress, based on their sensitivity to environmental and structural variations. We therefore tested purified EGFP, EYFP, ECFP, and DsRed proteins against the heme-peroxidase/H(2)O(2) reaction. We found that peroxidase-mediated oxidation resulted in up to 99.5% quenching of EYFP fluorescence (but not that of other fluorescent proteins) in a dose-dependent manner. Western blotting revealed inter- and intramolecular cross-linking. The observed detection limit for hydrogen peroxide was approximately 100 nM, well below the extracellular levels previously reported to occur in mammalian tissue during signaling. Combined expression of EYFP (quenchable) and ECFP or EGFP (nonquenchable) is expected to allow sensitive monitoring of oxidative stress.
A 27 mV output ripple 92% efficiency buck converter using a multi-bit delta-sigma modulator controller and segmented output switch in 180 nm CMOS (2016)

In this paper, a DC-DC buck converter using a multi-bit (two-bits) delta-sigma modulator to control segmented output switches of the converter is proposed to enhance its efficiency and improve its output ripple. This converter operates in continuous condition mode (CCM). Here, the two output bits of the modulator control the switching of the main and the supplementary switches. The circuit is simulated in 180 nm CMOS technology and the simulation results show a peak efficiency of 92% for the converter. The output current can reach up to 1.2A and the input voltage range is from 3.6 V to 1.8 V. The output ripple is 19 mV, 23 mV and 27 mV for 1.5 V, 1.8 V and 2 V output voltages, respectively.
Secondary Forces in Protein Folding (2019)

A complete inventory of the forces governing protein folding is critical for productive protein modeling, including structure prediction and <i>de novo</i> design, as well as understanding protein misfolding diseases of clinical significance. The dominant contributors to protein folding include the hydrophobic effect and conventional hydrogen bonding, along with Coulombic and van der Waals interactions. Over the past few decades, important additional contributors have been identified, including C-H···O hydrogen bonding, <i>n</i>→π* interactions, C5 hydrogen bonding, chalcogen bonding, and interactions involving aromatic rings (cation-π, X-H···π, π-π, anion-π, and sulfur-arene). These secondary contributions fall into two general classes: (1) weak but abundant interactions of the protein main chain and (2) strong but less frequent interactions involving protein side chains. Though interactions with high individual energies play important roles in specifying nonlocal molecular contacts and ligand binding, we estimate that weak but abundant interactions are likely to make greater overall contributions to protein folding, particularly at the level of secondary structure. Further research is likely to illuminate additional roles of these noncanonical interactions and could also reveal contributions yet unknown.
Negative resist behavior of neutral sodium atoms deposited on self-assembled monolayers (2007)

The authors report their initial studies of the negative resist behavior of neutral sodium atoms deposited on alkanethiol molecules during neutral atom lithographic processing. Their results show that neutral sodium atoms incident upon octadecanethiol, the longest molecule of the various alkanethiols among alkanethiol self-assembled monolayers (SAMs), formed the most robust negative resist during the patterning process and made high quality patterning profile. In order to interpret the nature of the surface interaction between neutral sodium atoms and SAMs, they examine the surface components using x-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and rinse tests. Their results indicate that sodium neutral atoms do not chemically react with or physically damage the SAMs but rather accumulate on and possibly diffuse into the SAMs.
FDTD study of resonance Processes in metamaterials (2005)

The finite-difference time-domain simulations in the frequency domain are used to study resonance phenomena in left-handed metamaterials consisting of the arrays of split-ring resonators (SRRs) and metal rods. It is demonstrated that, at frequencies corresponding to the band of enhanced transmission of the metamaterial, the half-wavelength resonances occur in both the SRRs and rods. The observed resonances in rods make questionable the applicability of the plasma concept to the analysis of the metamaterial performance. We also show that overlapping of electric or magnetic fields at resonance causes coupling between resonators and assembling them in three-dimensional groups, which rearrange in dependence on frequency inside the transmission band. As the result, the resonance phenomena in the metamaterial proceed essentially nonuniform, although the size of the metamaterial units is less than the wavelength. We suggest that coupling between resonators is capable of providing the electromagnetic response, similar to that observed at the backward-wave propagation in double-negative media. The latter is demonstrated on the example of the all-dielectric metamaterial composed from an array of dielectric resonators.
Genetics of Carney Complex (2013)

Abstract Carney complex (CNC) is an autosomal dominant multiple neoplasia and lentiginosis syndrome characterised by spotty skin lesions, cardiac and other myxomas and different types of endocrine tumours. The PRKAR1A gene, which codes for the regulatory subunit type 1‐alpha of the cyclic adenosine monophosphate (cAMP)‐activated protein kinase A, is responsible for more than two‐thirds of the cases of CNC described to date. Currently, more than 120 different disease‐causing PRKAR1A sequence variants have been reported. Other involved genes for adrenal hyperplasias include phosphodiesterases PDE11A and PDE8B . Additional genes are likely to be identified that may expand our understanding on the pathophysiology of the cAMP signalling pathway and how genetic defects cause CNC and its individual components such as adrenal tumours. Key Concepts: Inactivating PRKAR1A mutations cause CNC because PRKAR1A haploinsufficiency leads to uncontrolled PKA activity. The majority (∼80%) of PRKAR1A mutations causing CNC result in an early stop codon generation and degradation of the mutant RNA through nonsense‐mediated RNA decay (NMD). Recently, novel types of PRKAR1A mutations have been described: large gene rearrangements and small indels resulting in an elongated protein through downstream shift of the stop codon. The penetrance of PRKAR1A mutations is more than 95% by the age of 50 years. PDE11A and PDE8B genetic defects contribute to the CNC phenotype, but they may also independently cause forms of adrenal hyperplasia, mainly isolated micronodular adrenocortical disease (iMAD). Genotype–phenotype correlation is limited, but there are certain mutations that cause more frequently certain endocrine manifestations such as isolated Cushing syndrome. The use of new genomic techniques has led to the identification of new genetic defects in PRKAR1A and related genes in CNC.
Monitoring Nanoparticle-Mediated Cellular Hyperthermia with A High-Sensitivity Biosensor (2014)

Reporter activity was responsive to macroscopic and nanoparticle heating and activity correlated with measured macroscopic thermal dose. Significant cellular responses were observed with NP heating under doses that were insufficient to measurably change the temperature of the system. Under these conditions, the reporter response correlated with proximity to cells loaded with heated nanoparticles. These results suggest that NP and macroscopic hyperthermia may be distinctive under conditions of mild hyperthermia.
A general method for the synthesis of glycerophospholipids (1986)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA general method for the synthesis of glycerophospholipidsKarol S. Bruzik, Grzegorz Salamonczyk, and Wojciech J. StecCite this: J. Org. Chem. 1986, 51, 12, 2368–2370Publication Date (Print):June 1, 1986Publication History Published online1 May 2002Published inissue 1 June 1986https://pubs.acs.org/doi/10.1021/jo00362a035https://doi.org/10.1021/jo00362a035research-articleACS PublicationsRequest reuse permissionsArticle Views570Altmetric-Citations35LEARN 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
Multilevel Resistive Switching in Hf-Based RRAM (2019)

In this paper, the multilevel switching behaviors of resistive random-access memory (RRAM) devices with three different dielectric materials such as HfO2, HfZrO2 and HfAlO2 are investigated. We have further explored the switching characteristics with two different top electrode materials and with different processing environments. In all devices we have introduced a thin buffer layer to reduce switching power and improve the uniformity. Variation in the resistive behavior (Roff/Ron values) of different RRAM structures were observed and was correlated with possible oxygen vacancy related defects present in the dielectric.