In Inertial Confinement Fusion (ICF), the asymmetry of a hot spot is an important influence factor in implosion performance. Neutron penumbral imaging, which serves as an encoded-aperture imaging technique, is one of the most important diagnostic methods for detecting the shape of a hot spot. The detector image is a uniformly bright range surrounded by a penumbral area, which presents the strength distribution of hot spots.
View Article and Find Full Text PDFThe new hohlraum experimental platform and the quasi-3D simulation model are developed to enable the study of the indirect drive experiment using the six-cylinder-port hohlraum for the first time. It is also the first implosion experiment for the six laser-entrance-hole hohlraum to effectively use all the laser beams of the laser facility that is primarily designed for the cylindrical hohlraum. The experiments performed at the 100 kJ Laser Facility produce a peak hohlraum radiation temperature of ∼222 eV for ∼80 kJ and 2 ns square laser pulse.
View Article and Find Full Text PDFDeuterium-tritium neutron yield has reached up to about 10 at the 100 kJ-level laser facility, which makes measurement of neutron emission images possible with the neutron imaging system. There are two methods to collect neutron images from the scintillator array, optical fiber taper and the lens system. Here, we report a design of the lens system for the neutron imaging system at the 100 kJ-level laser facility.
View Article and Find Full Text PDFIn inertial confinement approaches to fusion, the asymmetry of target implosion is a major obstacle to achieving high gain in the laboratory. A recently proposed octahedral spherical hohlraum makes it possible to naturally create spherical target irradiation without supplementary symmetry control. Before any decision is made to pursue an ignition-scale laser system based on the octahedral hohlraum, one needs to test the concept with the existing facilities.
View Article and Find Full Text PDFThe reduced graphene oxide supported Zn-doped BiMoO nanocomposites (ZnBiMoO/RGO) are synthesized by an easy one-step solvothermal method for the rapid degradation of ciprofloxacin (CIP). Characterization analyses show that BiMoO nanosheets are uniformly supported on RGO, for which the agglomeration of BiMoO is effectively inhibited, leading to more exposure of surface active sites. The degradation rate of ZnBiMoO/RGO on CIP reached 90% after 120 min of visible light irradiation, which was 10.
View Article and Find Full Text PDFA heterojunction of NiFe layered double hydroxide (NiFe LDH)-BiMoO (BMO) loaded on reduced graphene oxide (RGO) sheets was synthesized via an eco-friendly solvothermal reaction. The structural characterization shows that NiFe LDH-BMO heterojunctions are well-distributed on the surface of silk-like transparent RGO sheets. The modification of BMO by NiFe LDH and RGO greatly enhances the photocatalytic performance of BMO for degradation of tetracycline (TC) under visible light.
View Article and Find Full Text PDFThe accuracy of the determination of the burn-averaged ion temperature of inertial confinement fusion implosions depends on the unfold process, including deconvolution and convolution methods, and the function, i.e., the detector response, used to fit the signals measured by neutron time-of-flight (nToF) detectors.
View Article and Find Full Text PDFA coaxial, high performance diamond detector has been developed for neutron diagnostics of inertial confinement fusion at ShenGuangIII laser facility. A Φ10 mm × 1 mm "optical grade" chemical-vapor deposition diamond wafer is assembled in coaxial-designing housing, and the signal is linked to a SubMiniature A connector by the cathode cone. The coaxial diamond detector performs excellently for neutron measurement with the full width at half maximum of response time to be 444 ps for a 50 Ω measurement system.
View Article and Find Full Text PDFNeutron emission measurement at the HL-2A tokamak device with a liquid scintillation detector is described. The detector was placed at a location with little structure material in the field of view, and equipped with a gain monitoring system which could provide the possibility to evaluate the gain variation as well as to correct for the detector response. Time trace of the neutron emissivity was obtained and it was consistent with the result of a standard (235)U fission chamber.
View Article and Find Full Text PDFBackground: Although increased volume of pericardial fat has been associated with decreased cardiac function, it is unclear whether this association is mediated by systemic overall obesity or direct regional fat interactions. We hypothesized that if local effects dominate, left ventricular (LV) function would be most strongly associated with pericardial fat that surrounds the left rather than the right ventricle (RV).
Methods: Female obese subjects (n = 60) had cardiovascular magnetic resonance (CMR) scans to obtain measures of LV function and pericardial fat volumes.
A new compact stilbene crystal neutron spectrometer has been investigated and applied in the neutron emission spectroscopy on the EAST tokamak. A new components analysis method is presented to study the anisotropic light output in the stilbene crystal detector. A Geant4 code was developed to simulate the neutron responses in the spectrometer.
View Article and Find Full Text PDFThe ability of human serum albumin (HSA) to bind fatty acids (FA) in multiple sites has been revealed by many studies. Here we detect and characterize nine individual binding sites by two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy of 18-[(13)C]-oleic acid (OA) complexed with HSA. We characterize site-specific FA binding by addition of (i) different FA molar ratios (from 1:1 to 4:1 OA:HSA) to observe the order of filling and occupancy of binding sites; (ii) methyl-β-cyclodextrin, as a FA acceptor, to observe the dissociation of FA; and (iii) drugs (with known binding sites in the crystal structure) to reveal the correspondence of three NMR peaks with sites in the crystal structure.
View Article and Find Full Text PDFLiver fatty acid binding protein (L-FABP), a cytosolic protein most abundant in liver, is associated with intracellular transport of fatty acids, nuclear signaling, and regulation of intracellular lipolysis. Among the members of the intracellular lipid binding protein family, L-FABP is of particular interest as it can i), bind two fatty acid molecules simultaneously and ii), accommodate a variety of bulkier physiological ligands such as bilirubin and fatty acyl CoA. To better understand the promiscuous binding and transport properties of L-FABP, we investigated structure and dynamics of human L-FABP with and without bound ligands by means of heteronuclear NMR.
View Article and Find Full Text PDFStorage of lipid in ectopic depots outside of abdominal visceral and subcutaneous stores, including within the pericardium and liver, has been associated with obesity, insulin resistance, and cardiovascular risk. We sought to determine whether anatomically distinct ectopic depots were physiologically correlated and site-specific effects upon cardiovascular function could be identified. Obese subjects (n = 28) with metabolic syndrome but without known atherosclerotic disease and healthy controls (n = 18) underwent magnetic resonance imaging (MRI) and proton MR spectroscopy (MRS) to quantify pericardial and periaortic lipid volumes, cardiac function, aortic compliance, and intrahepatic lipid content.
View Article and Find Full Text PDFHsp70 chaperones are involved in the prevention of misfolding, and possibly the folding, of newly synthesized proteins. The members of this chaperone family are capable of interacting with polypeptide chains both co- and posttranslationally, but it is currently not clear how different structural domains of the chaperone affect binding specificity. We explored the interactions between the bacterial Hsp70, DnaK, and the sequence of a model all-alpha-helical globin (apoMb) by cellulose-bound peptide scanning.
View Article and Find Full Text PDFLittle is known about polypeptide conformation and folding in the presence of molecular chaperones participating in protein biosynthesis. In vitro studies on chaperone-substrate complexes have been mostly carried out with small peptide ligands. However, the technical challenges associated with either competing aggregation or spectroscopically unfavorable size and exchange rates have typically prevented analysis of larger substrates.
View Article and Find Full Text PDFWe present in this paper 2H,13C MAS correlation experiments that are performed on a uniformly 2H,13C,15N labeled sample of Nac-Val, and on the uniformly 2H,15N labeled dipeptide Nac-Val-Leu-OH. The experiments involve the measurement of 2H T1 relaxation times at two different magnetic fields, as well as the measurement of the 2H tensor parameters by evolution of the 2H chemical shift. The data are interpreted quantitatively to differentiate between different side chain motional models.
View Article and Find Full Text PDFPolymerization of the soluble beta-amyloid peptide into highly ordered fibrils is hypothesized to be a causative event in the development of Alzheimer's disease. Understanding the interactions of Abeta with inhibitors on an atomic level is fundamental for the development of diagnostics and therapeutic approaches, and can provide, in addition, important indirect information of the amyloid fibril structure. We have shown recently that trRDCs can be measured in solution state NMR for peptide ligands binding weakly to amyloid fibrils.
View Article and Find Full Text PDFSpectral resolution imposes a major problem on the evaluation of MAS solid-state NMR experiments as larger biomolecular systems are concerned. We show in this communication that decoupling of the (13)C-(13)C homonuclear scalar couplings during stroboscopic detection can be successfully applied to increase the spectral resolution up to a factor of 2-2.5 and sensitivity up to a factor of 1.
View Article and Find Full Text PDFIn this communication, we suggest that transferred residual dipolar couplings (trRDCs) can be employed to restrain the structure of peptide inhibitors transiently binding to beta-amyloid fibrils. The effect is based on the spontaneous alignment of amyloid fibrils with the fibril axis parallel to the magnetic field. This alignment is transferred to the transiently binding peptide inhibitor and is reflected in the size of the trRDCs.
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