gebhart/patrepeval huggingface dataset:
Removal of nonconstant daily variation by means of wavelet and functional data analysis (2009)

We propose a novel approach based on wavelet and functional principal component analysis to produce a cleaner index of the intensity of the symmetric ring current. We use functional canonical correlations to show that the new approach more effectively extracts symmetric global features. The main result of our work is the construction of a new index, which is an improved version of the existing wavelet‐based index (WISA) and the old Dst index, in which a constant daily variation is removed. Here, we address the fact that the daily component varies from day to day and construct a “cleaner” index by removing nonconstant daily variations.
ChemInform Abstract: Synthesis and Reactivity of Novel Perfluoroalkylated Synthons. Atypical Reactivity of Perfluoroalkylated Azirines and Aziridines. (1993)

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.
Distribution of Hydrophobic Probe Molecules in Lipid Bilayers. 2. Time-Resolved Fluorescence Anisotropy Study of Perylene in Vesicles (1997)

The orientational distribution and rotational dynamics of planar perylene molecules incorporated into spherical vesicles of palmitoyl-δ-9-oleoyl(16:0,18:1)phophatidylcholine (POPC) was studied using time-resolved fluorescence anisotropy. The experimental anisotropy decay curves were analyzed using a global target approach. Here, anisotropy curves obtained at six temperatures above the gel−lamellar phase transition of the vesicles as well as the two combinations of excitation and emission wavelengths, (256, 470 nm) and (410, 470 nm), were fitted simultaneously. We have utilized two sets of orientational distributions of perylene in the bilayer. One set contains various one-population orientational distributions, while the other consists of models in which the probes are distributed over two distinct orientational populations. We find that in general the models yield statistically equivalant solutions, though the two-population models need a substantially smaller number of fit parameters. The existence of two distinct orientational populations of perylene in the lipid vesicle bilayer is in agreement with the results of Monte Carlo dynamics simulations in the preceding paper, but we argue that additional independent information is needed in order to remove the remaining ambiguities. We conclude that time-resolved anisotropy experiments on macroscopically unoriented samples do not provide sufficient information in order to fully characterize the orientational distribution of probe molecules in the bilayers.
Characterization of Single- and Double-Stranded DNA on Gold Surfaces (2004)

Single- and double-stranded deoxy ribonucleic acid (DNA) molecules attached to self-assembled monolayers (SAMs) on gold surfaces were characterized by a number of optical and electronic spectroscopic techniques. The DNA-modified gold surfaces were prepared through the self-assembly of 6-mercapto-1-hexanol and 5'-C(6)H(12)SH -modified single-stranded DNA (ssDNA). Upon hybridization of the surface-bound probe ssDNA with its complimentary target, formation of double-stranded DNA (dsDNA) on the gold surface is observed and in a competing process, probe ssDNA is desorbed from the gold surface. The competition between hybridization of ssDNA with its complimentary target and ssDNA probe desorption from the gold surface has been investigated in this paper using X-ray photoelectron spectroscopy, chronocoulometry, fluorescence, and polarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS). The formation of dsDNA on the surface was identified by PM-IRRAS by a dsDNA IR signature at approximately 1678 cm(-)(1) that was confirmed by density functional theory calculations of the nucleotides and the nucleotides' base pairs. The presence of dsDNA through the specific DNA hybridization was additionally confirmed by atomic force microscopy through colloidal gold nanoparticle labeling of the target ssDNA. Using these methods, strand loss was observed even for DNA hybridization performed at 25 degrees C for the DNA monolayers studied here consisting of attachment to the gold surfaces by single Au-S bonds. This finding has significant consequence for the application of SAM technology in the detection of oligonucleotide hybridization on gold surfaces.
Field experiments to study seafloor seismoacoustic response (1990)

Results of a 5-year program to measure the seismoacoustic properties of unlithified sediments in the seafloor are presented. A field technique utilizing a geophone array on the seafloor was used to obtain detailed travel-time curves, and a new signal source powered by electrically detonated, eight-gauge shotgun shells was used to focus energy into the bottom and eliminate much of the high-frequency water-borne noise that usually accompanies explosive sources. A variety of inversion techniques including slant stacking and cross multiplication were used to obtain dispersion curves and constrained least-squares inversion utilizing partial derivatives was employed to develop an iterative method to obtain velocity and attenuation as a function of depth. Data from a wide range of sediments ranging from soft Holocene mud to stiff overconsolidated clay are presented. The resulting geoacoustic models reflect the influence of the present overburden pressure and the geologic history, which largely determines the in situ porosity. [Work supported by ONR, Code 11250A.]
Inhibition of p38 mitogen-activated protein kinase alters microRNA expression and reverses epithelial-to-mesenchymal transition (2013)

Acquired chemoresistance and epithelial-to-mesenchymal transition (EMT) are hallmarks of cancer progression and of increasing clinical relevance. We investigated the role of miRNA and p38 mitogen-activated protein kinase (MAPK) signaling in the progression of breast cancer to a drug-resistant and mesenchymal phenotype. We demonstrate that acquired death receptor resistance results in increased hormone-independent tumorigenesis compared to hormone-sensitive parental cells. Utilizing global miRNA gene expression profiling, we identified miRNA alterations associated with the development of death receptor resistance and EMT progression. We further investigated the role of p38 MAPK in this process, showing dose-dependent inactivation of p38 by its inhibitor RWJ67657 and decreased downstream ATF and NF‑κB signaling. Pharmacological inhibition of p38 also decreased chemoresistant cancer tumor growth in xenograft animal models. Interestingly, inhibition of p38 partially reversed the EMT changes found in this cell system, as illustrated by decreased gene expression of the EMT markers Twist, Snail, Slug and ZEB and protein and mRNA levels of Twist, a known EMT promoter, concomitant with decreased N‑cadherin protein. RWJ67657 treatment also altered the expression of several miRNAs known to promote therapeutic resistance, including miR‑200, miR‑303, miR‑302, miR‑199 and miR‑328. Taken together, our results demonstrate the roles of multiple microRNAs and p38 signaling in the progression of cancer and demonstrate the therapeutic potential of targeting the p38 MAPK pathway for reversing EMT in an advanced tumor phenotype.
Kinetic analyses of Biolog community profiles to detect changes in inoculum density and species diversity of river bacterial communities (1998)

The kinetics of response curves from Biolog community profiles for heterotrophic bacteria from a river in Nova Scotia, Canada have been analyzed to generate lag, slope, and asymptote parameters. The river water samples were treated with one of three supplements of Escherichia coli (in situ levels, 10(3) CFU/mL, or 10(6) CFU/mL) and one of five concentrations of chlorine (0, 1, 3, 5, or 7 ppm) to satisfy a full factorial design. The chlorine treatments decreased the inoculum density by up to 2 log values and decreased the species evenness. The E. coli supplements increased the inoculum density and decreased the species richness. Examination of the asymptotes did not reveal any significant effects owing to E. coli, but differences owing to the chlorine were detected. Analyses of the slopes showed a similar insignificance of the effects of E. coli and a lack of treatment effect owing to chlorine. The lag analyses also showed no significant E. coli effects, but showed a significant effect owing to chlorine. The discrepancy produced with the slope analysis (i.e., no chlorine effect) may represent an anomaly of the Biolog community approach. The use of lag phase was impaired because of the problem of infinite lags from wells that had no response, but a principle component analysis with a reduced set of substrates did suggest some influence of E. coli on the community profile. An examination of the substrates metabolized by the river water compared with pure E. coli revealed that the Biolog profiles of the river communities were not a simple summation of the component parts. In light of the lack of uniformity between these analyses, where the outcome depended on which parameter was used, caution is advised in interpreting Biolog community profiles on the basis of only one parameter.
Chemical Laser Action in Low Pressure Metal Vapor Flames (1973)

Chemiluminescence in the visible has indicated the production of electronically excited products in the low pressure reactions of alkaline earlh metals with oxygen, halogens, halogen compounds and other oxidants. Thermochemical calculations on many such systems have indicated energy release more than adequate for electronic excitation of the product molecules. Comparisons of radiative lifetimes, rates of chemical reaction and col-lisional de-excitation indicate the possibility of population inversion and chemical laser action based on such electronically excited product molecules. The literature is reviewed to analyze the theoretical possibility of lasing action using alkaline earth systems. Although spin-conservation laws limit the rates of certain reactions, there appears to be sufficient promise to this approach.
Re-entrant spin glass behaviour and large magnetocaloric effect in Er<sub>2</sub>PtSi<sub>3</sub> (2017)

We present the magnetic properties and magnetocaloric effect of ternary intermetallic compound Er2PtSi3 with the orthorhombic Ba2LiSi3-type structure. Dc magnetization, ac susceptibilit, magnetic relaxation, electrical resistivity and specific heat measurements indicate that this system undergoes two magnetic phase transitions from a paramagnetic state sequentially to an antifwerromagnetic state at TN=5.4 K and then to a random spin freezing state at Tf=2.4 K. In addition, the large magnetocaloric effect is also observed for the Er2PtSi3 alloy. Near its Néel temperature TN, the maximum magnetic entropy change, relative cooling power and maximum adiabatic temperature change are estimated to be 16.1 Jkg-1K-1, 290 Jkg-1 and 7.7 K, respectively, for a field change of 5 T. These results suggest that Er2PtSi3 should be classified as a re-entrant spin-glass system and can be considered as a potential low-temperature magnetic refrigeration material.
Heat treatment prior to testing allows detection of antigen of Dirofilaria immitis in feline serum (2014)

These results indicate that heat treatment of samples prior to testing can improve the sensitivity of antigen assays in feline patients, supporting more accurate diagnosis of this infection in cats. Surveys conducted by antigen testing without prior heat treatment of samples likely underestimate the true prevalence of infection in cats.
Homocysteine, a thrombogenic agent, suppresses anticoagulant heparan sulfate expression in cultured porcine aortic endothelial cells. (1993)

Previous studies showed that homocysteine, a thrombo-atherogenic and atherogenic agent, inhibits an endothelial thrombomodulin-protein C anticoagulant pathway. We examined whether homocysteine might affect another endothelial anticoagulant mechanism; i.e., heparin-like glycosaminoglycan-antithrombin III interactions. Incubations of porcine aortic endothelial cell cultures with homocysteine reduced the amount of antithrombin III bound to the cell surface in a dose- and time-dependent fashion. The inhibitory effect was observed at a homocysteine concentration as low as 0.1 mM, and the maximal suppression occurred at 1 mM of homocysteine after 24 h. In contrast with a marked reduction in the maximal antithrombin III binding capacity (approximately 30% of control), the radioactivity of [35S]sulfate incorporated into heparan sulfate on the cell surface was minimally (< 15%) reduced. The cells remained viable after homocysteine treatment. Although neither net negative charge nor proportion in total glycosaminoglycans of cell surface heparan sulfate was altered by homocysteine treatment, a substantial reduction in antithrombin III binding capacity of heparan sulfate isolated from homocysteine-treated endothelial cells was found using both affinity chromatography and dot blot assay techniques. The antithrombin III binding activity of endothelial cells decreased after preincubation with 1 mM homocysteine, cysteine, or 2-mercaptoethanol; no reduction in binding activity was observed after preincubation with the same concentration of methionine, alanine, or valine. This sulfhydryl effect may be caused by generation of hydrogen peroxide, as incubation of catalase, but not superoxide dismutase, with homocysteine-treated endothelial cells prevented this reduction, whereas copper augmented the inhibitory effects of the metabolite. Thus, our data suggest that the inhibited expression of anticoagulant heparan sulfate may contribute to the thrombogenic property resulting from the homocysteine-induced endothelial cell perturbation, mediated by generation of hydrogen peroxide through alteration of the redox potential.
Physicochemical Properties of Oosporein, the Major Secreted Metabolite of the Entomopathogenic Fungus <i>Beauveria brongniartii</i> (2005)

Abstract Oosporein ( 1 ) is the major secondary metabolite excreted by Beauveria brongniartii (S acc. ) P etch (Ascomycota: Clavicipitaceae), an entomopathogenic fungus infesting the larvae of Melolontha melolontha L. (Coleoptera: Scarabaeidae; common European cockchafer). Physicochemical parameters were established to allow a better understanding of the spatiotemporal distribution of this marker substance in the environment. i ) The dependence of the oosporein solubility ( C s ) from proton concentration and temperature was assessed. Oosporein is a rather strong organic acid. The basal solubility of oosporein ( C in aqueous citrate/HCl buffer at pH 1.23) was found to be 24.8±0.3 μ M . The p K a of the first deprotonation step was determined to be 2.42±0.02. A nonlinear van't Hoff equation was established for the temperature dependency of the oosporein solubility (ln C s = a + bT −1 + c ln T , with a =−123.3, b =2678.9, and c =19.5). ii ) A second and third deprotonation step was found in Britton–Robinson ‐buffered aqueous solution. The associated p K a values were determined as 6.79±0.08 and 9.19±0.03. iii ) The stability of oosporein at different pH values and temperatures was addressed. Oosporein degraded quickly under moderate alkaline conditions and with increased temperatures. The half‐life dropped below 20 h at pH≥8.0 and T ≥43°. The analysis of the Arrhenius plot allowed to calculate the activation energies ( E a ) as 102±17 (pH 6), 100±5 (pH 8), and 91±6 kJ/mol (pH 10). iiii ) The octanol/water partition coefficient ( P O ) and its pH dependence were also determined. The distribution coefficient ( D O ) for oosporein at pH 1.2 was found to be 53.7±4.1 (log D O =1.73±0.03). The partition coefficient P O for undissociated oosporein was calculated as 56.6 (log P O =1.75). From the physicochemical properties, it can be concluded that oosporein can hardly be adsorbed by organisms.
Absolute asymmetric synthesis. I. Mechanism of the photochemical synthesis of nonracemic helicenes with circularly polarized light. Wavelength dependence of the optical yield of octahelicene (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAbsolute asymmetric synthesis. I. Mechanism of the photochemical synthesis of nonracemic helicenes with circularly polarized light. Wavelength dependence of the optical yield of octaheliceneWilliam J. Bernstein, Melvin Calvin, and Ole BuchardtCite this: J. Am. Chem. Soc. 1972, 94, 2, 494–498Publication Date (Print):January 1, 1972Publication History Published online1 May 2002Published inissue 1 January 1972https://pubs.acs.org/doi/10.1021/ja00757a029https://doi.org/10.1021/ja00757a029research-articleACS PublicationsRequest reuse permissionsArticle Views991Altmetric-Citations109LEARN 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
A correlated method for quantifying mixed and dispersed carbon nanotubes: analysis of the Raman band intensities and evidence of wavenumber shift (2005)

Abstract We present an experimental investigation of a correlated quantitative analytical method based on advanced Raman spectroscopy. This method was developed for the intensity weight distribution analysis of mixed and dispersed carbon nanotube (CNT) mixtures. For Raman spectroscopy, mixtures of single‐walled CNTs (SWNTs) and multi‐walled CNTs (MWNTs) were prepared and dispersed on a coverslip. Mixtures were made in the range from 1 to 100 mg (wt%) of SWNTs in 100 to 1 mg (wt%) of MWNTs. The ratios of the relative intensities of the Raman bands corresponding to pure SWNTs and pure MWNTs were used for the construction of calibration curves used for quantitative analysis. The relative intensity of the deconvoluted spectral bands shows a characteristic feature at 1350 and 1592 cm −1 which was found to be proportional to the relative amounts of SWNTs and MWNTs in the mixtures. A correlation between the atomic force microscopy images and the tangential mode Raman intensity ratio was used without the need for other analytical techniques. With this feature, it is possible to quantify the different components in the mixed, dispersed or unknown bulk of the CNTs investigated. Copyright © 2005 John Wiley & Sons, Ltd.
Hollow-waveguide-based transmission of a Q-switched Nd:YAG laser beam for biological tissue ablation (1999)

The cyclic-olefin-polymer (COP)-coated silver hollow waveguide has been applied to transmit the 1064-nm, Q-switched Nd:YAG laser beam. The Nd:YAG laser pulses with 14 - 18 ns pulse widths (FWHM) were coupled to the 1-mm inner diameter, 1-m long waveguides. A single-shot laser energy of 142 mJ/pulse (9.8 MW) was transmitted with a transmission efficiency of 95.5% under the straight waveguide condition. The corresponding laser fluence and peak intensity at the waveguide output end reached as high as 18.1 J/cm<SUP>2</SUP> and 1.25 GW/cm<SUP>2</SUP> respectively. It was found that the waveguide bending and the increase in the pulse repetition rate caused decrease in the available maximum transmitted energy. But stable transmission of 50 mJ/pulse (6.5 J/cm<SUP>2</SUP>) was obtained at a pulse repetition rate of 10 Hz even under the 90-degree-bent waveguide condition (R equals 50 cm). We conclude that the hollow waveguide has the capability of transmitting high-peak-power (greater than 1 MW) laser pulses for use in some medical applications including tissue- ablation-based treatments.
Modeling and analysis of remote memory access programming (2016)

Recent advances in networking hardware have led to a new generation of Remote Memory Access (RMA) networks in which processors from different machines can communicate directly, bypassing the operating system and allowing higher performance. Researchers and practitioners have proposed libraries and programming models for RMA to enable the development of applications running on these networks, However, the memory models implied by these RMA libraries and languages are often loosely specified, poorly understood, and differ depending on the underlying network architecture and other factors. Hence, it is difficult to precisely reason about the semantics of RMA programs or how changes in the network architecture affect them. We address this problem with the following contributions: (i) a coreRMA language which serves as a common foundation, formalizing the essential characteristics of RMA programming; (ii) complete axiomatic semantics for that language; (iii) integration of our semantics with an existing constraint solver, enabling us to exhaustively generate coreRMA programs (litmus tests) up to a specified bound and check whether the tests satisfy their specification; and (iv) extensive validation of our semantics on real-world RMA systems. We generated and ran 7441 litmus tests using each of the low-level RMA network APIs: DMAPP, VPI Verbs, and Portals 4. Our results confirmed that our model successfully captures behaviors exhibited by these networks. Moreover, we found RMA programs that behave inconsistently with existing documentation, confirmed by network experts. Our work provides an important step towards understanding existing RMA networks, thus influencing the design of future RMA interfaces and hardware.