Formation of chiral charge-transfer complex with axially chiral 1,1′-bi-2-naphthol and viologen derivatives

By using three types of viologen derivatives, we synthesized chiral charge-transfer (CT) complexes with an axially chiral 1,1′-bi-2-naphthol molecule and successfully controlled the crystal structure and inclusion ability of the third component by changing the viologens.     

CT血流灌注结合血脑屏障标志蛋白对中毒性休克患者神经元损伤的评价价值

选择2017年12月~2018年11月我院收治的100例经临床确认的中毒性休克患者的临床资料,所有患者均进行CT血流灌注成像检查,原始图像经工作站自带的脑灌注软件处理后产生灌注参数伪彩图像,测量病变侧及对侧大脑半球多个解剖部位的脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)、达峰时间(TTP)等灌注参数,计算病变侧/对侧的对比值(rCBF、rCBV、rMTT、rTTP)。并使用免疫组学方法检测不同患者外周血及脑脊液中血脑屏障通透性与紧密连接蛋白claudin-5、occludin、ZO-1、JAM-1、NOS和NSE的表达水平变化,并比较灌注参数与血脑屏障标志蛋白水平的相关性。结果显示,观察组患者外周血及脑脊液rCBF显著下降,rTTP降低,rPS升高(P<0.05),但两组rMTT、rCBV比较,差异无统计学意义(P>0.05)。观察组患者外周血及脑脊液claudin-5、occludin、ZO-1、NOS显著下降,JAM-1、NSE明显升高(P<0.05)。观察组claudin-5、occludin、ZO-1和NOS与rCBF、rTTP呈正相关,与rPS呈负相关;JAM-1和NSE与rCBF、rTTP呈负相关,与rPS呈正相关。rCBF、rTTP、JAM-1、NSE与神经元损伤程度呈正相关,claudin-5、occludin、ZO-1和NOS与神经元损伤程度呈负相关。上述结果表明CT血流灌注参数结合血脑屏障标志蛋白可有效评估中毒性休克患者神经元损伤程度,值得推广和应用。     

氧—接触电荷转移（O2—CCT）复合物的研究进展

氧可与有机分子形成接触电荷转移复合物。本文阐述了Ｏ２－ＣＣＴ复合物的形成机制部位与平衡及其紫外吸收特点，综述了Ｏ２－ＣＣＴ复合物在有机物氧化，电离势测定，氧传感器，烃类选择氧化及光聚合等领域的研究与应用进展。     

传统解剖学特征与深度学习相结合的肺叶分割算法

CT图像中肺叶位置的确定对于肺部疾病的准确定位以及定性定量分析具有重要意义。为了提高肺叶自动分割准确率,提出了一种结合气管,血管等传统解剖学特征以及深度学习的肺叶分割算法。对原始图像进行预处理,获取肺实质、气管、血管以及基于深度学习网络的肺裂分割结果;整合来自多个解剖结构的信息生成分水岭分割所需成本图像;通过基于深度学习网络的肺叶粗分割结果,获取肺叶标记区域;执行基于标记的分水岭分割,实现肺叶的自动分割。选取了来自上海市肺科医院的20例含有肺部疾病患者的CT图像对该方法进行验证,最终的Jaccard相似性系数为92.4%。实验结果表明方法具有较高的肺叶分割精度,并且具有较强的鲁棒性。     

Biofunctionalized silver and gold nanoparticles as potential curative agents

In this study, the bark of an important medicinal plant, Indigofera aspalathoides is utilized as a bioreductant for the synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). The formation of nanoparticles was monitored, and the reaction parameters were optimized by UV–Vis spectroscopy. The attachment of biocomponents as stabilizer was proved employing Fourier‐transform infrared (FT‐IR) studies. Through transmission electron microscopy (TEM), the morphology was found to be predominantly spherical and a mixture of triangle and hexagon in the case of AgNPs and AuNPs, respectively. The crystallite size of AgNPs and AuNPs was affirmed through X‐ray diffraction (XRD) studies using Sherrer formula as 22.03 and 47.70 nm, respectively. DPPH method was adopted to analyse the free‐radical quenching ability, and the AgNPs, AuNPs and extract showed inhibition of 76%, 89% and 59% at a concentration of 200 μg ml^?1, and the corresponding IC₅₀ values were 86.49, 55.20 and 149.19 μg ml^?1. The binding of nanoparticles to calf‐thymus DNA (CT‐DNA) was through groove and the high binding constants (8.49 × 10⁶ M^?1 and 2.34 × 10⁷ M^?1 for AgNPs and AuNPs) point out the potential of these nanoparticles as curative drugs. The MTT assay showed that AgNPs were 100% toxic, and the low IC₅₀ value suggests that this can be used in the medicinal field as a safe drug.     

Polymorphism of Supramolecular Charge-Transfer Complex Composed of 10,10′-dihydroxy-9,9′-biphenanthryl and p-benzoquinone

Charge-transfer (CT) complexes were prepared using racemic (rac)-10,10′-dihydroxy-9,9′-biphenanthryl, which has a large and highly π-conjugated phenanthrene ring, as the electron donor and p-benzoquinone as the electron acceptor. This CT system showed a polymorphism.     

A fourth-order divergence-free method for MHD flows

This paper extends our previous third-order method [S. Li, High order central scheme on overlapping cells for magneto-hydrodynamic flows with and without constrained transport method, J. Comput. Phys. 227 (2008) 7368–7393] to the fourth-order. Central finite-volume schemes on overlapping grid are used for both the volume-averaged variables and the face-averaged magnetic field. The magnetic field at the cell boundaries falls within the dual grid and is naturally continuous so that our method eliminates the instability triggered by the discontinuity in the normal component of the magnetic field. Our fourth-order scheme has much smaller numerical dissipation than the third-order scheme. The divergence-free condition of the magnetic field is preserved by our fourth-order divergence-free reconstruction and the constrained transport method. Numerical examples show that the divergence-free condition is essential to the accuracy of the method when a limiter is used in the reconstruction. The high-order, low-dissipation, and divergence-free properties of this method make it an ideal tool for direct magneto-hydrodynamic turbulence simulations.     

Degenerate Critical States for Polydisperse Polymer Solutions

If, in a spinodal point, the rank of the stability matrix is less than the order of this matrix minus one, then Gibbs′ determinant criterion for the critical state loses its importance since it is fulfilled automatically by the spinodal condition. In this paper a generalized critical state criterion is established for such degenerate cases in polydisperse polymer solutions.     

孤立性肺结节的CT形态学特征结合GSI模式的诊断学研究

本研究探讨CT联合能谱成像(GSI)模式诊断孤立性肺结节的临床价值。选取经肺穿刺活检或手术病理学证实的肺孤立性结节患者110例(110个肺结节),对患者的CT平扫、GSI平扫资料进行分析。根据病理学结果分为良性组(炎性结节、非典型腺瘤样增生)41例、恶性组(肺癌小结节)69例,对比两组患者的肺小结节形态学特征综合评分、动静脉期的能谱曲线斜率、40 keV CT值、标准化碘浓度(NIC)的差异。结果显示,恶性组患者的毛刺征和棘突征、分叶征、血管集束征、胸膜凹陷征、支气管征、病灶内钙化、病灶强化值及孤立性肺结节形态学特征总分均高于良性组(P<0.05);恶性组患者的动脉期、静脉期的能谱曲线斜率、40 keV CT值、NIC均低于良性组(P<0.05)。肺部孤立性恶性结节的形态学特征与肺部良性结节差异显著,恶性结节的能谱曲线斜率、40 keV CT值、NIC值与良性结节差异明显。因此,综合分析结节的形态学特征及GSI参数对其良恶性诊断具有重要意义。     

CTA联合CTP在预测急性脑梗死预后中的价值

本研究探讨CT血管成像(CTA)联合CT灌注成像(CTP)在预测急性脑梗死预后的价值。选取急性脑梗死患者102例,分为预后良好组和不良组,分析预后良好和不良患者ASPECTS、CTP参数差异。预后不良患者CTA图像ASPECTS评分<3分明显高于预后良好患者(P<0.05);预后不良患者病灶处脑血容量(CBV)和脑血流量(CBF)明显低于预后良好患者(P<0.05),达峰时间(TTP)和平均通过时间(MTT)明显高于预后良好患者(P<0.05);ASPECTS评分联合CBV、CBF及MTT预测预后不良的ROC曲线下面积为0.895(P<0.05),灵敏性和特异性分别为90.00%和84.10%。CTA联合CTP预测急性脑梗死患者预后有一定应用价值。