Titanium dioxide (TiO2) modified bismuth titanate (Bi2Ti2O7) heterojunction was supported on reduced graphene oxide (RGO) to obtain Bi2Ti2O7/TiO2/RGO composite by simple solvothermal method. Neither ...toxic reductant nor toxic solvent was used. The structural characterization shows that spherical Bi2Ti2O7/TiO2 nanoparticles are loaded on silk-like transparent RGO. By contrast with each individual component, the prepared Bi2Ti2O7/TiO2/RGO composite shows significantly enhanced photocatalytic performance on the degradation of ciprofloxacin (CIP) under simulated sunlight. The degradation efficiency of CIP using Bi2Ti2O7/TiO2/RGO composite as the catalyst reaches 95% in 180 min and maintains at 88% after 5 photocatalytic reaction cycles. The enhancement of photocatalytic performance of Bi2Ti2O7/TiO2/RGO5 composite is due to the synergistic effect among Bi2Ti2O7, TiO2 and RGO. Moreover, compared with other recently reported bismuth-based catalysts, Bi2Ti2O7/TiO2/RGO exhibits higher photocatalytic activity, or shows comparable activity but with less dosage used. Free radical scavenger experiments were also carried out to explore the photocatalytic degradation mechanism.
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•The graphene-modified Bi2Ti2O7/TiO2 heterojunction was first constructed by a simple solvothermal method.•The addition of graphene improves the separation of photo-generated carriers effectively.•The photocatalyst shows high photocatalytic activity for the degradation of CIP.•Synergistic effect among Bi2Ti2O7, TiO2 and RGO improves the photocatalytic activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The 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 18-13C-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. At 1:1 and 2:1 OA:HSA ratios, three sites were shown to fill sequentially. These high-affinity sites were well resolved from additional sites (one medium-affinity and five low-affinity) observed at 3:1 and 4:1 OA:HSA ratios. Methyl-β-cyclodextrin extracted OA from individual sites in the reverse order of filling. FA bound in three low-affinity sites were displaced by drugs shown to bind in crystalline HSA to FA sites 7 and 3 (Sudlow’s drug sites I and II, respectively) and FA site 6. With this strategy, 2D NMR spectral analysis permits site-specific characterization of the binding of drugs and FA and provides a sensitive probe of the mutual effects of FA and ligand binding.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
In laser-driven inertial confinement fusion, driving pressure boosting and smoothing are major challenges. A proposed hybrid-drive (HD) scheme can offer such ideal HD pressure performing ...stable implosion and nonstagnation ignition. Here we report that in the hemispherical and planar ablator targets installed in the semicylindrical hohlraum scaled down from the spherical hohlraum of the designed ignition target, under indirect-drive (ID) laser energies of ~43–50 kJ, the peak radiation temperature of 200 ± 6 eV is achieved. And using only direct-drive (DD) laser energies of 3.6–4.0 kJ at an intensity of 1.8 × 10
15
W/cm
2
, in the hemispherical and planar targets the boosted HD pressures reach 3.8–4.0 and 3.5–3.6 times the radiation ablation pressure respectively. In all the above experiments, significant HD pressure smoothing and the important phenomenon of how a symmetric strong HD shock suppresses the asymmetric ID shock pre-compressed fuel are demonstrated. The backscattering and hot-electron energy fractions both of which are about one-third of that in the DD scheme are also measured.
Liver 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. The overall conformation of human L-FABP shows the typical β-clam motif. Binding of two oleic acid (OA) molecules does not alter the protein conformation substantially, but perturbs the chemical shift of certain backbone and side-chain protons that are involved in OA binding according to the structure of the human L-FABP/OA complex. Comparison of the human apo and holo L-FABP structures revealed no evidence for an “open-cap” conformation or a “swivel-back” mechanism of the K90 side chain upon ligand binding, as proposed for rat L-FABP. Instead, we postulate that the lipid binding process in L-FABP is associated with backbone dynamics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A high-neutron yield platform imploded by a thin shell target is generally built to probe nuclear science problems, and it has the advantages of high neutron yield, ultrashort fusion time, micro ...fusion zone, isotropic and monoenergetic neutron. Some analytical models have been proposed to interpret exploding-pusher target implosion driven by a long wavelength laser, whereas they are imperfect for a 0.35 μm laser implosion experiment. When using the 0.35 μm laser, the shell is ablated and accelerated to high implosion velocity governed by Newton’s law, ablation acceleration and quasi-adiabatic compression models are suitable to explain the implosion of a laser direct-drive thin shell target. The new analytical model scales bang time, ion temperature and neutron yield for large variations in laser power, target radius, shell thickness, and fuel pressure. The predicted results of the analytical model are in agreement with experimental data on the Shenguang-III prototype laser facility, 100 kJ laser facility, Omega, and NIF, it demonstrates that the analytical model benefits the understanding of experiment performance and optimizing the target design of high neutron yield implosion.
A single crystal chemical vapor deposition (scCVD) diamond detector has been characterized and employed for the neutron measurement at the HL-2A tokamak device. The scCVD diamond detector has been ...deposited with 5μm of lithium fluoride (LiF) layer to enhance the sensitivity to thermal neutrons. Time stability of the detector has been studied with α-source and good performance has been found for more than 12h. Neutron irradiations have been performed in four quasi-monoenergetic neutron fields in the energy range from 2.50MeV to 16.03MeV. The measured response function of the scCVD diamond detector to 14.13MeV neutrons shows a narrow 12C (n, α)9Be reaction peak which is well isolated from other structures by about 1MeV in energy, indicating the great potential as a fast neutron spectrometer. Neutron measurement of deuterium plasma discharge was established at the HL-2A tokamak device, and good consistence has been revealed among this detector signal and other related signals.
•Operational parameters have been optimized by α-source tests in terms of energy resolution and time stability.•The detector has been characterized with quasi-monoenergetic neutron sources with energies ranging from 2.50MeV to 16.03MeV.•Time evolution of the neutron yield at HL-2A tokamak plasma discharge has been assessed with the scCVD diamond detector.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Diagnosing the layered cryogenic DT implosions with traditional absorption based x-ray backlight radiography in inertial confinement fusion is a challenge because of the low opacity of the cold fuel. ...Refraction enhanced x-ray phase-contrast imaging was proposed for diagnosing optically opaque material. In this paper, A Monte Carlo tool based on Geant4 is employed to model the x-ray phase-contrast imaging for diagnosing cold fuel layer in cryogenic implosions. This model can successfully explain the x-ray phase-contrast imaging experimental results on a micro focus x-ray tube with triple-layer ablator capsules. Furthermore, the radiographs of ignition-scale capsule target is calculated. The fuel layer of DT ice can be observed with the phase contrast imaging and the image is faded using absorption imaging only. Our simulations show that the shape of cold fuel and implosion velocity can be inferred directly with the phase contrast imaging in inertial confinement fusion(ICF).
Storage 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. Fasting plasma lipoproteins, glucose, insulin, and free-fatty acids were measured. Pericardial and intrahepatic (P < 0.01) and periaortic (P < 0.05) lipid volumes were increased in obese subjects vs. controls and were strongly and positively correlated (P ≤ 0.01) but independent of BMI (P = NS) among obese subjects. Intrahepatic lipid was associated with insulin resistance (P < 0.01) and triglycerides (P < 0.05), whereas pericardial and periaortic lipid were not (P = NS). Periaortic and pericardial lipid positively correlated to free-fatty acids (P ≤ 0.01) and negatively correlated to high-density lipoprotein (HDL) cholesterol (P < 0.05). Pericardial lipid negatively correlated to cardiac output (P = 0.03) and stroke volume (P = 0.01) but not to left ventricular ejection fraction (P = 0.46). None of the ectopic depots correlated to aortic compliance. In conclusion, ectopic storage of lipid in anatomically distinct depots appeared tightly correlated but independent of body size. Site-specific functional abnormalities were observed for pericardial but not periaortic lipid. These findings underscore the utility of MRI to assess individual differences in ectopic lipid that are not predictable from BMI.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Two neutron time-of-flight (nToF) detectors have been employed to measure the neutron time-of-flight spectrum in different lines-of-sight, i.e., at the equator plane and the south pole, on ...Shenguang-III (SG-III) laser facility. The contribution of scattered neutrons has been calculated with the Monte Carlo code JMCT for each nToF detector. The results show that the scattered neutron spectrum is dominated by neutrons scattered on materials in the experiment hall, including the vacuum chamber. The shape of the scattered neutron spectrum depends on the view line, which has been observed with nToF detectors located in the experiment hall of the SG-III laser facility. A method based on the convolution of the calculated neutron time-of-flight spectrum and the instrument response function has been developed for the ion temperature determination. The calculated neutron spectra with the contribution of scattered neutrons can fit the measured results. No obvious ion temperature anisotropy has been observed on the SG-III laser facility at present.
A ternary visible light-driven catalyst, reduced graphene oxide (RGO)-based Bi
2
MoO
6
(BMO), modified with CdS, was synthesized for the degradation of ciprofloxacin through solvothermal method. ...Neither toxic reductant nor toxic solvent was used. The structural characterization shows that graphene oxide sheets were reduced, while BMO nanoplates and CdS nanoparticles grew to form CdS–BMO/RGO simultaneously. The modification of BMO with CdS and RGO extraordinarily enhances the photocatalytic performance of BMO on the degradation of ciprofloxacin (CIP) under visible light irradiation. The photodegradation rate of CIP over CdS–BMO/RGO photocatalyst is approximately 24 times faster than that of BMO. The improvement of the photocatalytic performance is attributed to the synergistic effect among CdS, BMO and graphene. Moreover, CdS–BMO/RGO exhibits better performance on the degradation of CIP than most bismuth oxide-containing catalysts recently reported. Degradation of various organic contaminants in addition to CIP has also been studied, showing that CdS–BMO/RGO exhibits much higher photocatalytic performance on degrading molecules containing smaller conjugated system.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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