gebhart/patrepeval huggingface dataset:
Inactivation of Glutamine Synthetase by Tabtoxinine-β-lactam (1984)

The inactivation of glutamine synthetase by tabtoxinine-fi-lactam, a phytotoxin produced by Pseudomonas syringae pv. tabaci, was shown to be irreversible. The chloroplast and cytosolic forms of the enzyme from pea leaves (Pisum sativum L.) were separated, purified, and found to be kinetically similar with K. values for glutamate of 6.7 and 43 millimolar and for ATP of 2.0 and 1.3 millimolar, respectively. Both forms were irreversibly inactivated by the toxin at equal rates. Using the chloroplast form, it was found that inactivation by tabtoxinine-,B-lactam required ATP. Glutamate and low levels of ammonia (<2 millimolar) slowed the rate of inactivation, whereas high levels of ammonia (5, 20, and 50 millimolar) accelerated it. The inactivation proceeded at a faster rate as the pH was increased from pH 6.5 to 7.5. The role which cellular compartmentalization could play in the inactivation is discussed.
Determining the interphase thickness and properties in polymer matrix composites using phase imaging atomic force microscopy and nanoindentation (2000)

In polymer matrix composites, the interface between the reinforcing phase and the bulk phase is paramount to the overall performance of the composite as a structural material. This interface is now thought to be a distinct, three-dimensional phase surrounding the reinforcing phase called the interphase. The developments of the atomic force microscope and nanoindentation devices have facilitated the investigation of the interphase. Previously, force modulation atomic force microscopy (AFM) and nanoindentation were the primary methods used to determine the size of the interphase and its stiffness relative to the bulk phase. The present investigation utilized phase imaging AFM and nanoindentation to examine the interphase in a glass fiber-reinforced epoxy matrix composite. Nanoindentation experiments indicated that the relatively stiff fiber might have caused a gradient in the modulus across the interphase region. Specifically, the modulus next to the fiber approached that of the fiber and decreased to that of the bulk polymer as the distance away from the fiber increased. Once the fiber was removed by chemical etching, this gradient reversed itself; hence, nanoindentation, due to the fiber bias, was not found to be adequate for measuring actual interphase properties. It was found that phase imaging AFM was a highly useful tool for probing the interphase, because it involves much lower interaction forces between the probe and the sample than force modulation or nanoindentation. The interphase in the model composite investigated was found to be softer than the bulk phase with a thickness of 2.4-2.9 μm, and was independent of fiber silane pretreatment, for silane pretreatments between 0.1% and 5.0% (initial aqueous concentration).
External heat transfer capability of a submerged SMR containment: The Flexblue case (2016)

Flexblue is a 160 MWe, transportable and subsea-based nuclear power unit operating up to 100 m depth several kilometers away from the shore. The concept is based on existing technologies and experience from the oil&gas, civil nuclear and shipbuilding industries. In a post-Fukushima world, its safety features are particularly relevant. The immersion provides inherent protection against most external aggressions including tsunamis, extreme weather conditions and malevolent actions. The vicinity and the availability of an infinite, permanent heat sink e the ocean e enhances the performance of the safety systems which, when designed to operate passively, considerably extend the grace period given to operators in case of accident. The present work investigates seawater natural convection fluid dynamics and heat transfer features, induced by the heating of Flexblue reactor containment, to evaluate the capabilities of the system to reject the decay power to the exterior in case of an accident. A preliminary lumped parameters approach has been adopted, revealing that the large diameter of the hull (14 m) is such that ranges of validity of empirical correlations for natural convection heat transfer are always exceeded and conditions for their correct application are not satisfied. Hence, a 2D, unsteady CFD analysis has been performed to simulate the natural convection flow in the ocean, thus obtaining predictions for heat flux distribution, hull superficial temperature profile and heat transfer coefficient. Both CFD sensitivity and parametric analyses have been carried out, even if within a 2D approach, to limit the computational burden. The results showed that the heat transfer process is globally satisfactory to ensure the safe cooling of the reactor. A 3D approach and an experimental campaign aimed at validating the CFD results have been planned.
Coma Correction in Czerny–Turner Spectrographs (1968)

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Charly D. Allemand, "Coma Correction in Czerny–Turner Spectrographs," J. Opt. Soc. Am. 58, 159-163 (1968) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article
Etude de la réponse de Lactobacillus sakei à l’oxydation des thiols. (2006)

23p + annexes Diplôme : Master Recherche
Length and depth resonances of surface cracks and their use for crack size estimation (1978)

Angular scattering from surface cracks has been used for determining the length of a surface crack. This technique assumes the physical availability of space to carry out an angular scattering experiment, and makes no estimation of the depth of the crack. In this work, we report a new technique where the scattering from surface cracks is made versus frequency, at one angle of incidence only. Length and depth resonances of the crack are observed and used to estimate the crack geometry. We made our measurements on EDM notches in steel. The geometry of the crack has been predicted with an accuracy of 10–20%.
Influence of Hyperbranched Multi-methacrylates for Dental Neat Resins on Proliferation of Human Gingival Fibroblasts (2000)

We have previously shown that hyperbranched multi-methacrylate (H-MMA)-modified dental resins have VLC activities, lower polymerization shrinkage, and improved mechanical properties, compared to the 2,2-bis[4-(2-hydroxy-3-methacryloyolxypropoxy)phenyl]propane/triethyleneglycol dimethacrylate (BisGMA/TEGDMA) neat resin. The results are due to the unique molecular structure and high molecular weight of H-MMA intermediates. The purpose of this study was to evaluate the biocompatibility of H-MMA-modified dental neat resins. The cell proliferation of three human gingival fibroblast strains on either H-MMA, BisGMA/TEGDMA, or a polystyrene disk was examined. Following 10 days of cell proliferation, there was no statistical difference in cell number between H-MMA-modified and unmodified resin disks. H-MMA-modified resins had less free monomer leaching than the unmodified resin but showed similar properties in water sorption and contact angle values. All these results suggest that the biocompatibility of H-MMA-modified dental neat resins is as good as that of commercially used BisGMA/TEGDMA resin and H-MMA has potential applications in dental composites.
Development of a dichroic beam splitter for Subaru AO188 (2008)

We have developed a dichroic beam splitter for the Subaru AO188, which reflects optical light (0.4-0.9 &mgr;m) for wavefront sensing and transmits near-infrared light (0.93-5.2 &mgr;m) for science observations. The beam splitter is made of 145mm × 200mm calcium fluoride substrate coated by fluoride and metal chalcogen compound multilayer, which should be a best way to realize high transmittance over wide wavelength range in the near infrared. However, since typical fluoride soft coating is less resistant to the moisture in the air, the fluoride coating become damaged as we use on the AO188 optical bench which is placed in the room temperature condition. We have performed several accelerated endurance tests of the beam splitter under high-humidity condition by changing the design of the coatings, and found an optimal solution with an oxide protection layer which prevents the damage of the dichroic coating and keeps high transmittance at near-infrared wavelength. In this paper, we report the results of the endurance tests and the performance of our dichroic beam splitter.
Low cost on-line non-invasive sewer flow monitoring (2013)

A novel acoustic sensor has been developed, capable of remotely monitoring the free surface ‘fingerprint’ of shallow flows. Temporal and spatial properties of this pattern are shown to contain information regarding the nature of the flow itself. The remote measurement can thereby be used to infer the bulk flow properties such as depth, velocity, and the hydraulic roughness of the pipe. The instrument is non-invasive and is also low cost, low maintenance, and low power. Such a device will allow for widespread monitoring of flow conditions in drainage networks, enabling pro-active maintenance and reliable real-time control.
Solvent Effects in Nuclear Magnetic Resonance. II. Critical Examination of the Reaction Field (1964)

The reaction-field concept is examined quantitatively using nuclear magnetic spectroscopy by determining the magnetic shielding constants of three protons within the same molecule as a function of dielectric constant: the results are based on the fact that the magnetic shielding constant of a bonded proton depends linearly on the effective electric field along the bond axis. It is shown that (1) the reaction field must take on different values at different points in the molecule, and (2) the calculated reaction field's dependence on ε for a dipole in a spherical or spheroidal cavity does not adequately describe the experimental reaction field's dependence on ε.
A very rapid electronic relaxation process in a highly conjugated Zn(<scp>ii</scp>)porphyrin–[26]hexaphyrin–Zn(<scp>ii</scp>)porphyrin hybrid tape (2015)

The excited-state energy relaxation processes of a Zn(II)porphyrin–[26]hexaphyrin–Zn(II)porphyrin triply linked hybrid tape, FZn, have been investigated by femtosecond transient absorption spectroscopy (TA), using a directly meso–meso linked hybrid trimer, HZn, as a reference compound. FZn has a very small S1–S0 energy gap through the expansion of π-conjugation and the absorption band at 1897 nm corresponds to its lowest singlet excited-state as a consequence of enhanced transition dipole moment that lies parallel to the long molecular axis. In TA measurements, we observe an energy transfer process (0.4 ps) from the Zn(II)porphyrin moiety to the [26]hexaphyrin core in HZn. In contrast to HZn, a biexponential decay with the time constants of 0.25 and 6.5 ps was observed in the decay profile of FZn. The detailed analysis of excitation wavelength, temperature and solvent dependent TA in FZn revealed that the electronic relaxation process (0.25 ps) from S1 to S0 is faster than the vibrational relaxation processes (5.9 ps) in the excited and ground states due to a very small S1–S0 energy gap through the expansion of π-conjugation. Accordingly, we demonstrate that electronic deactivation overtakes vibrational relaxation processes in a highly conjugated FZn.
Reversible Formation of a Cationic Palladium(II) Hydride [HPd(PPh <sub>3</sub> ) <sub>2</sub> ] <sup>+</sup> in the Oxidative Addition of Acetic or Formic Acid to Palladium(0) in DMF (2000)

The oxidative addition of acetic or formic acid to Pd0(PPh3)4 in DMF affords a cationic palladium(II) hydride, [trans-HPd(PPh3)2(DMF)]+, with acetate or formate as the counter anion. The two reactions are reversible. The equilibrium and kinetic constants of the oxidative additions have been determined.
Respiratory gating of magnetic resonance images (1984)

When compared to most other high resolution imaging modalities (i.e. CT), magnetic resonance (MR) requires significantly more time for data acquisition. The average MR scan time ranges from 2 to 6 minutes. Cardiac and respiratory motion cause large artifacts and significantly reduce the resolution of internal structures. Thus, a method for gating MR acquisition with the respiratory cycle was developed. The respiratory cycle was followed via a pneumatic bellows placed around the patients chest, observing the change in pressure caused by motion of the chest with a transducer linked to the bellows by plastic tubing. The voltage output from the transducer was monitored by an electronic device which could be set to start and stop acquisition at any portion of the respiratory cycle. The authors have performed studies on 5 volunteers and 23 patients gating the acquisition of data to the end-expiratory portion of the respiratory cycle. Respiratory gating eliminated the gross motion artifacts normally present at 0.5 T and markedly improved visualization of hepatic vessels. In 2 patients one with a pheochromocytoma and one post splenic embolization, the tissue abnormalities could only be diagnosed with the use of respiratory gating. Gating of data acquisition by chest wall motion inmore » MR is feasible and significantly improves the diagnostic potential of MR imaging, particularly at higher field strengths where motion artifact is more severe.« less
Silicon carbide emitter and burner elements for a TPV converter (1995)

SiC bulk material is manufactured in the desired shape from an organopolysiloxane‐based pre‐ceramic polymer by pyrolysis. For an evaluation prototype, an emitter was made in form of a 7’’ tube with 1.5’’ diameter for operation at 1400 °C–1700 °C in conjunction with a GaSb photovoltaic cell (Eg=0.67 eV). The spectral dependence of the emittance of the SiC material in this temperature range was determined between 1.2 μm and 3.2 μm. Additionally, the surface morphology for a high density and a porous low density silicon carbide specimen are compared using SEM micrography. The range of material properties obtainable with this manufacturing process, and the high emissivity of the SiC, suggest that this material may be suitable for the emitter and burner elements in a thermophotovoltaic converter.
Simulating water and smoke with an octree data structure (2004)

We present a method for simulating water and smoke on an unrestricted octree data structure exploiting mesh refinement techniques to capture the small scale visual detail. We propose a new technique for discretizing the Poisson equation on this octree grid. The resulting linear system is symmetric positive definite enabling the use of fast solution methods such as preconditioned conjugate gradients, whereas the standard approximation to the Poisson equation on an octree grid results in a non-symmetric linear system which is more computationally challenging to invert. The semi-Lagrangian characteristic tracing technique is used to advect the velocity, smoke density, and even the level set making implementation on an octree straightforward. In the case of smoke, we have multiple refinement criteria including object boundaries, optical depth, and vorticity concentration. In the case of water, we refine near the interface as determined by the zero isocontour of the level set function.
Orientation of transition moments in excited-state absorption of polymethine and squarylium dyes (2003)

Summary form only given. Over the past several years our efforts have been directed toward a systematic investigation of nonlinear properties of a new series of polymethine dyes (PDs) and squarylium dyes (SDs) in liquid solutions and polymeric media. These studies led to the development of several new dyes showing strong excited-state absorption (ESA) in the visible region with the ratios of excited-to ground-state absorption cross-sections up to 200 at 532 nm. One of these dye's (labeled PD2338) chemical structure is shown along with its singlet energy-level diagram. The study of the excited state transition moments will lead to a deeper understanding of the nature of ESA in organic molecules and will aid in the quantum-chemical calculations for the prediction of their nonlinear properties. To measure the orientation of the transition moments we use a pump-probe geometry in which the probe polarization is fixed and the pump polarization can be rotated using a halfwave plate. In a pump-probe experiment an intense pump beam induces a nonlinear response in the medium that is then sensed by the weak probe beam. This experimental procedure may be used to determine population decay kinetics and rotational relaxation times. These decay times can be measured by conducting three measurements for the pump polarization-parallel, perpendicular, and at the magic angle (57.3 degrees) to the probe. The results for PD2338, using the second harmonic of a picosecond (25 ps FWHM) Nd:YAG laser are shown.
Lipoplexes Formulation and Optimisation: In Vitro Transfection Studies Reveal No Correlation with In Vivo Vaccination Studies (2010)

The aim of these studies was to compare the effect of liposome composition on physico-chemical characteristics and transfection efficacy of cationic liposomes both in vitro and in vivo. Comparison between 4 popularly used cationic lipids, showed 3b-N-(dimethylaminoethyl)carbamate (DC-Chol) to promote the highest transfect levels in cells in vitro with levels being at least 6 times higher than those of 1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA). 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and dimethyldioctadecylammonium (DDA) and approximately twice as efficient as dipalmitoyl-trimethylammonium-propane (DPTAP). To establish the role of the helper lipid, DC-Chol liposomes were formulated in combination with either 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) or cholesterol (Chol) (1:1 molar ratio) with and without the addition of phosphatidyl choline. The choice of helper lipid incorporated within the bilayer was found to influence the formation of complexes, their resultant structure and their transfection efficiency in vitro, with SUV-DNA complexes containing optimum levels of DOPE giving higher transfection than those containing cholesterol. The inclusion of PC within the formulation also reduced transfection efficiency in vitro. However, when administered in vivo, SUV-DNA complexes composed of PC:Chol:DC-Chol at a molar ratio of 16:8:4 micromole/ml were the most effective at inducing splenocyte proliferation upon exposure to antigen in comparison to control spleens. These results demonstrate that there is no in vitro/in vivo correlation between the transfection efficacy of these liposome formulations and in vitro transfection in the above cell model cannot be taken as a reliable indicator for in vivo efficacy of DNA vaccines.
Anisotropy and dimensions of blow‐molded polyethylene bottles (1982)

Abstract A commercial blow‐molding grade, high‐density polyethylene resin was employed to produce cylindrical bottles in a commercial reciprocating screw‐extrusion blow‐molding machine. The distributions of thickness, crystallinity, birefringence, and impact strength were obtained at various positions. The thickness is greatest near the parting lines, while minimum thickness occurs at the top and bottom of the bottle. The thickness tends to be uniform in the middle section, in agreement with earlier studies of the parison during processing. Density and crystallinity distributions are closely associated with the distribution of thickness and its effect on the cooling rates prevailing during molding. Frozen stresses and birefringence are largest at the outer surface, where cooling rates are highest. The impact strength is lowest near the parting line. Photomicrographs suggest that this is associated with internal flow and crystallization phenomena.
LMS in prominent system subspace for fast system identification (2012)

In many system identification applications, the unknown system is characterized by time-varying parameters. Therefore, fast on-line identification is required in order to keep the system stable and improve the control performance. In this paper, we show that the dimensionality of system identification can be dramatically reduced if the unknown system is sparse, in the sense that its parameter set has a concise representation when expressed in a proper basis. In such cases, the system identification can be effectively carried out in a subspace of reduced dimension. Based on this theory, we further proposed two new least-mean-square (LMS) algorithms, namely, prominent system subspace LMS (PSS-LMS) and enhanced PSS-LMS (PSS-LMS+) to exploit this sparsity for fast system identification. Finally, we conducted experiments to compare the convergence performances of PSS-LMS, PSS-LMS+, and conventional LMS using numerical simulation, and the results confirm the superior performances of the proposed algorithms.
The SUMOylation of Matrix Protein M1 Modulates the Assembly and Morphogenesis of Influenza A Virus (2011)

SUMOylation is an important posttranslational modification for regulation of cellular functions and viral replication. Here, we report that protein SUMOylation regulates the replication of influenza A virus at the steps of viral maturation and assembly. Knocking down the SUMO-conjugating enzyme Ubc9 resulted in the reduction of virus production. Dissection of the virus life cycle revealed that SUMOylation is involved in the processes of virus maturation and assembly. The viral matrix protein M1 is SUMOylated at K242. A virus carrying the SUMO-defective M1 produced a lower titer of virus, while its viral proteins and viral RNA (vRNA) accumulated in the cells. Furthermore, the mechanistic studies showed that the SUMOylation of M1 is required for the interaction between M1 and viral RNP (vRNP) to form the M1-vRNP complex. The lack of M1 SUMOylation prevented the nuclear export of vRNP and subsequent viral morphogenesis. Taken together, our findings elucidate that the maturation and assembly of influenza A virus is controlled by the SUMO modification of M1 protein. Therefore, we suggest that M1 can serve as a target for developing a new generation of drugs for flu therapy.
Site-Directed Random Mutagenesis of AMP-Binding Residues in Adenylate Kinase1 (1993)

Two highly conservative residues, Val67 and Gln101, in adenylate kinase are located in the hydrophobic region putatively involved in binding of the adenine ring of AMP. We have performed polymerase chain reaction-based random mutagenesis of the two residues using recombinant chicken muscle adenylate kinase cDNA as a template. The synthetic oligonucleotide primers contained A,G,C,T-mixed bases in the codons corresponding to those for Val67 and Gln101. The amplified fragments were ligated with the expression plasmid pKK223-3, and the mutant proteins expressed were identified by immunoblotting. Enzymatically active mutant proteins were selected on the basis of the growth at 45 degrees C of the temperature sensitive Escherichia coli mutant for adenylate kinase. At position 67, various amino acid residues other than Val have been found to restore the growth at 45 degrees C of the ts mutant. In contrast, only Gln, His, and Met could be present at position 101. These results are compatible with the proposal that Val67 contributes to the AMP binding through hydrophobic interactions and Gln101 by forming a hydrogen bond with the adenine ring. Indeed, several purified Val67 and Gln101 mutant enzymes exhibited markedly high Km values for AMP, whereas the Km values for MgATP were comparable to those of the wild-type enzyme. Substrate specificity for nucleoside monophosphates was changed significantly by the mutagenesis of the two residues.
Characteristics of Linear Generator with SC Coil Configuration to Reduce Leakage Flux (2006)

An improved configuration of superconducting (SC) coils, whose end coils have small size, is studied to reduce their leakage flux. This configuration can strengthen the magneto-motive force of SC coils, so it can enlarge the lateral gap between generator coils and cryostat of SC coils to increase output power of linear generator. This paper presents the basic configuration of this system and examines their characteristics by numerical examples.