[en] Within the framework of linear response theory, the authors use the effective propagator including the internal line particle's finite width to study the energy loss rate of a fast moving parton's caused by the inductive field when it penetrates through QGP, A reasonable interpretation to the numerical result is provided

[en] Objective: To determine whether radiation dose can be reduced and image quality improved in routine head CT that were acquired with organ-based tube current modulation (TCM) technology. Methods: In a prospective study 50 adults patients scheduled for head CT used in both the routine axial and helical with TCM modes. Scan parameter: TCM mode were 120 kVp, 280 mA(Max mA threshold value), scan time 0.8 s/rol, the manual mode were 140 kVp, 170 mA for petrou bone, and 120 kVp, 150 mA for brain, scan time 2.0 s/rol. Radiation dose were measured directly from the CT scan indicated(CTDI and DIP). The image quality at the level of the posterior fossa and grey-white matter contrast and overall image were assessed by two readers using CT value and signal-to-noise ratio(SNR) detected, Reading orders were randomized. Results: Compared the routine axial scan mode, The TCM scan mode reduced tube current (44 ± 12) mA, exposure time (4.8 ± 0.8) s, radiation dose (38 ± 0.9)% [CTDI: (32.10 ± 9.0) mGy, (55.00 ± 7.2) mGy; DIP (442.10 ± 72) mGy · cm, ( 668.00 ± 26) mGy · cm]; The effective radiation dose is reduced by (1.5 ± 0.4) mSv, respectively. The image quality was effectively improved. Conclusion: Routine head CT scan using helical with TCM scan mode has reduced the superiority of the scan time and radiation dose. The image quality can comparable to routine axial scan mode. (authors)

[en] Highlights: • SiCN was prepared from MTS–C₃H₆–NH₃–H₂–Ar by CVI. • SiCN realized the designable composition by adjusting the reactant concentration. • SiCN with optimized composition had low ε and high tgδ. • SiCN with optimized composition realized a good wave-absorbing property. -- Abstract: Thermodynamics phase diagram of co-deposited C, SiC and Si₃N₄ from precursors of CH₃SiCl₃–C₃H₆–NH₃–H₂–Ar was investigated by using FactSage software and its embedded database. The yield of condensed phases in the co-deposition process was examined as the functions of the inject reactant ratios of C₃H₆/MTS, NH₃/MTS and H₂/MTS, and the temperature at a fixed pressure of 0.01 atm. The thermodynamic study was used to conduct and determine the deposition condition of silicon carbon nitride (SiCN) in the experimental process. The results show that C–SiC, C–SiC–Si₃N₄ and C–Si₃N₄ can be co-deposited by adjusting the reactant ratios and temperature in thermodynamics. In kinetics, SiCN ternary phase was successfully deposited in the porous Si₃N₄ preform by chemical vapor infiltration and chemical vapor deposition when T = 800 °C, P = 0.01 atm, [NH₃]/[MTS] = 0.5 and [C₃H₆]/[MTS] = 0.2–0.6. The surface morphology of the as-prepared SiCN presented the dense convex cell structure, and the rod-like Si₃N₄ in preform was uniformly covered by SiCN. The dielectric and electromagnetic (EM) properties of Si₃N₄–SiCN ceramics were evaluated in 8.2–12.4 GHz (X-band). With the increase of [C₃H₆]/[MTS] in the precursors, the content of carbon element and the intensity of Si–C bond in SiCN gradually increased, which made the permittivity, dielectric loss and EM shielding effectiveness of ceramics gradually increase and the EM reflection coefficient decrease. It is confirmed that the novel and component-designable SiCN ceramics possess the excellent EM absorbing property, offering a great possibility as the high-temperature matrix and coating candidate of ceramics matrix composites combining the structural and functional properties

[en] N-succinimidyl-4-[¹⁸F]fluorobenzoate([¹⁸F]SFB) was prepared using a multifunction chemistry process control unit module. The dried K₂₂₂/¹⁸F^- was resolubilized with a solution of 4-trimethlammoniumbenzoate trifluoromethane-sulfonate and reacted to produce ethyl-4-[¹⁸F] fluorobenzoate. The ethylester was subsequently hydrolyzed using alkali to obtain the 4-[¹⁸F] fluorobenzoic acid([¹⁸F]FBA). After purifying through Sep-Pak C18 cartridge, [¹⁸F]FBA was dissolved with TSTU in CH₃CN and reacted to produce [¹⁸F]SFB. The nucleophilic reaction reated for 10 min at 115 degree C in the covered vial, mixturing solvents with netrogen for several seconds and the ethylester was subsequently hydrolyzed using alkali. The decay-corrected yields of [¹⁸F]SFB were much higher. The radiochemical yield of [¹⁸F]SFB is (28.2±1.9) (n=5), and radiochemical purity of [¹⁸F]SFB is more than 90%. The whole reaction time is only 45 min from ¹⁸F-F^- to [¹⁸F]SFB. The whole reaction time can be shorten and the yield of product is high by using the multifunction chemistry process control unit module. It is a quick and highly efficient method for labeling bioactive compound. (authors)

[en] A rockburst is a dynamic disaster that occurs during underground excavation or mining which has been a serious threat to safety. Rockburst prediction and control are as important as any other underground engineering in deep mines. For this paper, we tested electromagnetic radiation (EMR) signals generated during the deformation and fracture of rock samples from a copper mine under uniaxial compression, tension, and cycle-loading experiments, analyzed the changes in the EMR intensity, pulse number, and frequency corresponding to the loading, and a high correlation between these EMR parameters and the applied loading was observed. EMR apparently reflects the deformation and fracture status to the loaded rock. Based on this experimental work, we invented the KBD5-type EMR monitor and used it to test EMR signals generated in the rock surrounding the Hongtoushan copper mine. From the test results, it is determined the responding characteristics of EMR signals generated by changes in mine-generated stresses and stress concentrations and it is proposed that this EMR monitoring method can be used to provide early warning for rockbursts. (paper)

[en] Despite the high theoretical specific capacity and energy density, the practical application of lithium‐sulfur (Li−S) battery is still hampered by the shuttle of lithium polysulfides and sluggish kinetics of cathode, which results in the loss of active materials and rapid capacity decay of the sulfur cathode. Herein, we develop novel hierarchical ultrathin porous carbon shell anchored with RuO${}_2$ nanoparticles as efficient cathode hosts for lithium‐sulfur batteries. The carbon shell can allow efficient impregnation of sulfur and provide effective spatial confinement to reduce polysulfide diffusion. In addition, the volume expansion of sulfur upon lithiation can be also remitted due to the sufficient space inside the carbon shell. The anchored RuO${}_2$ nanoparticles in the host material can synergistically enhance the immobilization of polysulfide and accelerate their redox reaction. Accordingly, this hierarchical structure based‐cathode containing 70.6 wt% sulfur content delivers enhanced electrochemical performances including high specific capacity, excellent rate performance and superior cycling stability. (© 2019 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

[en] Objective: Radiolabeled acetate was considered a potential tracer complimentary to ¹⁸F-FDG. The aim of the current study was to investigate and validate the feasibility of fully automated synthesis of ¹⁸F-fluoroacetate by a commercial synthesizer of FDG. Methods: ¹⁸F-fluoroacetate was synthesized on FDG synthesizer with column hydrolyze and purification on Sep-Pak column. The radiochemical purity and the stability were measured by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The biodistribution in NH mice was studied. PET imaging was performed on mice models bearing breast or lung cancers. Results: ¹⁸F-fluoroacetate was successfully synthesized with FDG synthesizer, avoiding time-consuming HPLC purification and reducing the cost. The yield was 59.3% (end of synthesis) in a short time (23 min) with radiochemical purity higher than 99%. The stability of ¹⁸F-fluoroacetate was high at room temperature, and toxicity low to NH mice. The slower clearance from blood was observed in NH mice. ¹⁸F-fluoroacetate PET imaging showed radioactive uptake in the lesions bore by mice models. Conclusion: ¹⁸F-fluoroacetate could be synthesized with FDG module and of potential in tumor imaging. (authors)

[en] The isolated study of electrophoretic transport of nanoparticles (that are innately charged through thermionic emission), with no ionic wind, has been conducted under uniform electric fields. Titania nanoparticles are produced using a burner-supported low-pressure premixed flame in a stagnation-point geometry from corresponding organometallic vapor precursor. The material processing flow field is probed in-situ using laser-induced fluorescence (LIF) to map OH-radical concentrations and gas-phase temperatures. The experimental results of particle growth under different applied electric fields are compared with computations using monodisperse and sectional models. The results show that such electric field application can decrease aggregate particle size (e.g. from 40 to 18 nm), maintain metastable phases and particle crystallinity, and non-monotonically affect primary particle size (e.g. from 6 to 5 nm) and powder surface area. A specific surface area (SSA) for anatase titania nanopowder of 310 m²/g, when synthesized under an applied electric field of 125 V/cm, is reported. Results are also given for the synthesis of alumina nanoparticles.

[en] Objective: To evaluate the automatic synthesis of ¹⁸F-labeled cyclic RGD peptide c(RGDyK)and its biological distribution in the tumor-bearing mice. Methods: N-succinimidyl-4-¹⁸F-fluorobenzoate (¹⁸F-SFB) was automatically synthesized and then re-dissolved in acetonitrile (MeCN). The cyclic RGD peptide c(RGDyK) was mixed with an hydrous DMSO and N, N-diisopropyl ethylamine (DIPEA). ¹⁸F-FBRGD was obtained by the reaction of peptide solution with 18 F-SFB. The final product was purified by HPLC gradient separation system and solid-phase extraction method. The biodistribution study and competition test of N-4-¹⁸F-fluorobenzoyl-RGD (¹⁸F-FB-RGD) in the tumor-bearing mice was performed. Results: The labeling yield of ¹⁸F-FB-RGD was (33.6±3.5)%. The synthesis time was 110 min. The radiochemical purity was more than 98%. The tumor uptake of ¹⁸F-FB-RGD was (3.43±0.15), (2.61±0.14), (2.11±0.13), and (1.79±0.18) %ID/g, respectively, at 30, 60, 90 and 120 min after injection. The ratio of tumor to muscle activity ranged from 4.26±0.69 to 5.80±0.78. The tumor uptake decreased dramatically after RGD blockage. The uptake was (0.46±0.21) %ID/g and (2.87±0.59) %ID/g in the blocked and unblocked mice, respectively, at 60 min after blockage. Conclusions: ¹⁸F-FB-RGD can be automatically synthesized and it may become a promising tumor imaging agent. (authors)

[en] The malignant tumors must establish a neovasculature to grow, to invade, and to metastasize, in which α_vβ₃ integrin plays an important role. It is reported that the α_vβ₃ integrin made their effection mainly by binding triplet peptides RGD sequence in the proteins of the extracellular matrix. Because is reported to there is no or rare α_vβ₃ integrin in normal cells but more in activated endothelial cells, RGD is the special target point for α_vβ₃ Integrin. RGD antagonistic peptides radiolabelled by direct or indirect way could be used to display tumor α_vβ₃ Integrin by nuclear medicine image. It is of significance to locate and quantitate tumor Integrin high special in early diagnosis and therapy. This article reviews the marking method of RGD peptide and study about the image of α_vβ₃ receptor. (authors)