MSCT血管成像技术在门静脉高压症中的临床应用价值

目的探讨多层螺旋CT（MSCT）血管成像技术（MSCT angiography,MSCTA）在门静脉高压症（portal hy-pertension,PHT）诊断及临床治疗中的价值。方法对50例PHT患者者行MSCTA,观察患者门静脉系统的解剖学类型、门静脉主干及其分支侧支循环显示情况;观察食管胃底静脉曲张的形态、位置及血供类型。结果 50例门静脉高压症患者门静脉及侧支循环显影包括：食管下段静脉曲张94.0%,胃底静脉曲张90.0%,胃左静脉曲张90.0%,食管旁静脉曲张72.0%,胃短、胃后静脉曲张32.0%,脾/胃-肾静脉分流28.0%,副脐静脉、腹壁静脉曲张26.0%,腹膜后-椎旁静脉曲张22.0%。对21例患者施行手术,手术与影像学诊断完全符合。MSCTA检出胃静脉曲张（gastric varices,GV）阳性49例所见的病状与胃镜下所见病状对比一致性较好。结论 MSCTA能为PHT患者判断病变程度、预测其并发症及选择治疗方案提供可靠的依据。     

基于信赖域技巧的共轭梯度方法的图像重建算法研究

图像重建算法是电容层析成像系统研究的关键技术,寻找一种重建图像速度和重建图像质量都能满足工业应用要求的图像重建算法是十分必要的。基于信赖域方法的共轭梯度算法是在普通共轭梯度算法的基础上提出的一种新的图像重建算法,提高了图像重建的质量与速度。     

Effects of ultraviolet–ozone treatment on organic-stabilized ZnO nanoparticle-based electron transporting layers in inverted polymer solar cells

Electron transporting layers (ETLs) in inverted polymer solar cells (I-PSCs) were fabricated by spin coating a colloidal dispersion of ZnO nanoparticles (NPs), and the effects of ultraviolet–ozone (UVO) treatment on the ZnO NP ETLs were investigated. The brief UVO treatment (<5 min) could considerably improve the performance of the resulting I-PSCs (∼30% increase in power conversion efficiency); whereas, excessive UVO treatment (>10 min) caused significant degradation. The characterization of the ZnO ETLs as a function of the UVO treatment duration revealed that brief treatment can remove the residual organic stabilizer molecules on the surface of the ZnO films by UV induced decomposition mechanism. However, excessive treatment can generate additional defects on/within the ZnO films, which can induce charge recombination. This effect was further confirmed by the thermal treatment of the ZnO ETLs at a high temperature (280 °C) at which the organic surfactants could be removed. Flexible I-PSCs were also fabricated using indium doped tin oxide coated plastic substrates and the usefulness of the room temperature UVO treatment was further confirmed in view of its potential applicability in flexible devices.     

Direct observation of ICT cations at the HTL/transparent semiconductor interface

The cation density at the interface of a transparent anode and an organic layer has been measured for several hole transport (HT) materials. The number of cations at the interface of ITO:MoO_x with rubrene, NPB, m-MTDATA and TCTA was found to range from 8 × 10¹³ to 1.5 × 10¹⁴ per cm² in freshly prepared devices. These values decreased by about 25% after one month. These cations are part of the dipole layer that results from the transfer of electrons from an organic layer, whose adiabatic ionization potential is less than the work function of the anode.     

In situ Characterization of SiO2 Nanoparticle Biointeractions Using BrightSilica

By adding a gold core to silica nanoparticles (BrightSilica), silica‐like nanoparticles are generated that, unlike unmodified silica nanoparticles, provide three types of complementary information to investigate the silica nano‐biointeraction inside eukaryotic cells in situ. Firstly, organic molecules in proximity of and penetrating into the silica shell in live cells are monitored by surface‐enhanced Raman scattering (SERS). The SERS data show interaction of the hybrid silica particles with tyrosine, cysteine and phenylalanine side chains of adsorbed proteins. Composition of the biomolecular corona of BrightSilica nanoparticles differs in fibroblast and macrophage cells. Secondly, quantification of the BrightSilica nanoparticles using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) micromapping indicates a different interaction of silica nanoparticles compared to gold nanoparticles under the same experimental conditions. Thirdly, the metal cores allow the investigation of particle distribution and interaction in the cellular ultrastructure by cryo nanoscale X‐ray tomography (cryo‐XT). In 3D reconstructions the assumption is confirmed that BrightSilica nanoparticles enter cells by an endocytotic mechanism. The high SERS intensities are explained by the beneficial plasmonic properties due to agglomeration of BrightSilica. The results have implications for the development of multi‐modal qualitative and quantitative characterization in comparative nanotoxicology and bionanotechnology.     

铱发光探针检测硝基芳香化合物机理

以铱(Ⅲ)配合物Ir（ppy）₃为发光探针,检测3种硝基芳香化合物,包括3?硝基苯甲酸、3?硝基苯甲醇、3?硝基三氟甲苯,并通过密度泛函理论计算结合光谱分析研究发光检测机理。结果表明,3?硝基苯甲酸、3?硝基苯甲醇和3?硝基三氟甲苯可淬灭Ir（ppy）₃在乙腈中的发光,检测效率K_SV分别为20.4、1.8 L/mmol和2.8 L/mmol,最低检测限分别达0.155×10^-6、1.760×10^-6 mol/L和1.116×10^-6 mol/L。Ir（ppy）₃对3?硝基苯甲酸、3?硝基苯甲醇和3?硝基三氟甲苯的发光检测机理为电子转移机理。     

Investigating the physics of disruptions with real-time tomography at JET

As JET is developing and testing operational scenarios for higher fusion performance, an increase in pulse disruptivity is being observed. On a deeper analysis, we find that several radiative phenomena play an active role in determining the outcome of the pulse. The analysis is enabled by the use of real-time tomography based on the bolometer diagnostic. Even though plasma tomography is an inverse problem, we use machine learning to train a forward model that provides the radiation profile directly, based on a single matrix multiplication step. This model is used to investigate radiative phenomena including sawtooth crashes, ELMs and MARFE, and their relationship to the radiated power in different regions of interest. In particular, we use real-time tomography to monitor the core region, and to throw an alarm whenever core radiation exceeds a certain threshold. Our results suggest that this measure alone can anticipate a significant fraction of disruptions in the JET baseline scenario.     

Lowest angle solution versus low-index axis solution for misorientations

A study of misorientation distributions in recrystallised high-strength IF steel has compared both the disorientation (lowest angle) solution and nearest low-index axis solution. It is shown that consideration of the lowest-angle misorientation distribution alone provides an incomplete and ambiguous distribution of nearest low-index misorientation axes.     

TEM study of superstructure in a perovskite lead lanthanum zirconate stannate titanate ceramic

The superstructure of an antiferroelectric Pb_0.97La_0.02(Zr_0.66Sn_0.25Ti_0.09)O₃ phase, whose composition is near the morphotropic-phase boundary, was characterized. Systematic selected-area diffraction revealed that there were two kinds of superlattice reflections in the pseudocubic reciprocal lattice, i.e. superlattice reflections (h, k, l all odd), and one-dimensional incommensurate superlattice reflections, where g denotes the vectors of fundamental or superlattice reflections. Convergent-beam electron diffraction disclosed that the average structure of the phase was rhombohedral with space group of . Based on the rhombohedral reciprocal lattice, the reflections were no longer superlattice but fundamental reflections, and the reciprocal vector of the one-dimensional incommensurate reflections was re-expressed as

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, where h, k, l are integers and (−h + k + l) = 3n. In the light of the average structure and the reflection condition, the superspace Bravais class of the phase with one-dimensional incommensurate structure was determined to be in a (3 + 1)-dimensional space. In addition, the origins of the superlattice reflections were also examined and discussed.