PEO／PBHE共混体系X射线散射研究

在聚环氧乙烷(PEO)/聚双酚A羟基醚(PBHE)共混体系中PEO是一个强质子受体,而PBHE是一个强质子给体,两者极易形成氢键,十分有利于形成互容对。笔者研究了PEO/PBHE共混体系的相容性,等温及非等温结晶动力学,本文根据Vonk提出的一维电子密度相关函数,分析了PEO/PBHE的SAXS现象,求得了共混体系的结晶度,片晶层厚度,过渡层厚度及长周期等结构参数。     

Mass spectrometry-based chemical mapping and profiling toward molecular understanding of diseases in precision medicine

Precision medicine has been strongly promoted in recent years. It is used in clinical management for classifying diseases at the molecular level and for selecting the most appropriate drugs or treatments to maximize efficacy and minimize adverse effects. In precision medicine, an in-depth molecular understanding of diseases is of great importance. Therefore, in the last few years, much attention has been given to translating data generated at the molecular level into clinically relevant information. However, current developments in this field lack orderly implementation. For example, high-quality chemical research is not well integrated into clinical practice, especially in the early phase, leading to a lack of understanding in the clinic of the chemistry underlying diseases. In recent years, mass spectrometry (MS) has enabled significant innovations and advances in chemical research. As reported, this technique has shown promise in chemical mapping and profiling for answering “what”, “where”, “how many” and “whose” chemicals underlie the clinical phenotypes, which are assessed by biochemical profiling, MS imaging, molecular targeting and probing, biomarker grading disease classification, etc. These features can potentially enhance the precision of disease diagnosis, monitoring and treatment and thus further transform medicine. For instance, comprehensive MS-based biochemical profiling of ovarian tumors was performed, and the results revealed a number of molecular insights into the pathways and processes that drive ovarian cancer biology and the ways that these pathways are altered in correspondence with clinical phenotypes. Another study demonstrated that quantitative biomarker mapping can be predictive of responses to immunotherapy and of survival in the supposedly homogeneous group of breast cancer patients, allowing for stratification of patients. In this context, our article attempts to provide an overview of MS-based chemical mapping and profiling, and a perspective on their clinical utility to improve the molecular understanding of diseases for advancing precision medicine.

An overview of MS-based chemical mapping and profiling, indicating its contributions to the molecular understanding of diseases in precision medicine by answering "what", "where", "how many" and "whose” chemicals underlying clinical phenotypes.     

STM study on quinacridone derivative assemblies: modulation of the two-dimensional structure by coadsorption with dicarboxylic acids

We describe the two-dimensional (2D) assemblies of N,N'-dialkyl-substituted quinacridone derivatives on highly orientated pyrolytic graphite observed by scanning tunneling microscopy, and focus our discussion on whether the supramolecular organization can be modulated by the coadsorption of dicarboxylic acids. Our experiments have demonstrated that the quinacridone derivatives can form different 2D nanostructures when coadsorbed with dicarboxylic acids of different length at the liquid/graphite interface. Interestingly, N,N'-dihexadecyl-substituted quinacridone derivative alternately takes two different conformations in two columns for its coadsorption with pentadecanedioic acid and form a gridlike structure. It is shown that a cooperative effect of different interactions can be modulated by introducing guest molecule, leading to formation of different self-assembled nanostructures.     

Hierarchical FeCo2S4@FeNi2S4 Core/Shell Nanostructures on Ni Foam for High-Performance Supercapacitors

The design of electrode materials with rational core/shell structures is promising for improving the electrochemical properties of supercapacitors. Hence, hierarchical FeCo₂S₄@FeNi₂S₄ core/shell nanostructures on Ni foam were fabricated by a simple hydrothermal method. Owing to their structure and synergistic effect, they deliver an excellent specific capacitance of 2393 F g⁻¹ at 1 A g⁻¹ and long cycle lifespan as positive electrode materials. An asymmetric supercapacitor device with FeCo₂S₄@FeNi₂S₄ as positive electrode and graphene as negative electrode exhibited a specific capacitance of 133.2 F g⁻¹ at 1 A g⁻¹ and a high energy density of 47.37 W h kg⁻¹ at a power density of 800 W kg⁻¹. Moreover, the device showed remarkable cycling stability with 87.0 % specific-capacitance retention after 5000 cycles at 2 A g⁻¹. These results demonstrate that the hierarchical FeCo₂S₄@FeNi₂S₄ core/shell structures have great potential in the field of electrochemical energy storage.     

不锈钢基/β-PbO2-TiO2-Co3O4复合镀层制备及其性能表征

使用直流复合电沉积方法制备不锈钢基β-PbO2、TiO2掺杂β-PbO2、Co3O4掺杂β-PbO2、TiO2和Co3O4共掺杂β-PbO2复合镀层材料.采用SEM、EDS、XRD和电化学测试等对复合电极进行形貌、成分、组成和催化活性表征,并且将不锈钢基/β-PbO2-TiO2-Co3O4电极应用到锌电积实验中.结果表明,添加Co3O4能提高PbO2电极的催化活性;添加TiO2可以起到细化晶粒,增大比表面积的作用;不锈钢基β-PbO2-TiO2-Co3O4复合镀层阳极与Pb-Ag合金阳极相比,锌电积槽电压降低为2.97V,电流效率提高到91.2％,使用寿命延长.     

磁旋光反射腔交流调制输出倍频信号特性分析

根据法拉第效应的非互易性原理,分析了磁旋光反射腔交流调制输出倍频信号相关的特性;具体研究了倍频信号幅度及角度检测灵敏度与调制角幅度θ0和反射腔反射率R的关系.研究结果表明:当调制角幅度较小时,输出倍频信号幅度随反射率R的增加而增加,最大值是正交调制法的18倍左右;利用倍频信号检测角度的灵敏度与正交法相比也得到多倍提高,...     

Two-dimensional self-assembly of linear molecular rods at the liquid/solid interface

We report on the synthesis and scanning tunneling microscopy (STM) studies of a series of linear molecular rods (1-5) comprising different numbers and/or spatial arrangements of perfluorinated benzene and benzene subunits interlinked with diacetylenes in the para position and decorated with or without terminal dodecyl chains. The molecules organize themselves into well-ordered 2D crystal structures at the liquid/solid interface through intermolecular and molecule-substrate interactions. Whereas the molecules substituted by dodecyl chains form the lamellar structures with alternating rigid core rows and alkyl chain rows, the unsubstituted ones change the orientation of the rigid backbones with respect to the lamellar axis. The molecular arrangement is not influenced by fluoro substituents on any phenyl ring of the backbone, which suggests that the interactions between the π-conjugated backbones are dominated by close packing rather than by the dipole moments of the rods or fluorine-based intermolecular interactions.     

Preparation of Poly (L-lactic Acid) Microsphere

Poly (L-lactic acid) (PLLA) microspheres were prepared by a solvent evaporation method based on an oil/water emulsion. The effect of the mass ratio of PLLA and poly(vinyl alcohol) (PVA) on the formation of the microspheres was discussed, and the influence of extraction speed of dichloromethane on the microsphere morphology was also studied. Moreover, the influences of the PLLA concentration and the volume ratio of water phase to dichloromethane phase were investigated. The results showed that stable microspheres can be obtained under the conditions that the mass ratio of PLLA to PVA is 20:1. Porous microspheres were obtained under faster evaporating speed of dichloromethane. The microsphere size increased with increasing PLLA concentration. The microsphere size also increased with the increase of the volume ratio of water phase to dichloromethane phase.     

丙酮/水混合体系合成聚苯胺的聚合过程研究

对丙酮/水体系中合成聚苯胺(PAn)的反应进行跟踪,通过聚合过程的开路电压、聚合温度、特性粘度和中间体的分子结构对聚合过程进行研究。结果表明,丙酮/水体系对控制产物的粒度和分子量都有利;当丙酮/水的体积比为0.2左右时,所得产物的各项性能较好。与水体系相比,在丙酮/水混合体系中聚合过程维持高电位的时间延长,聚合链增长时间和自加速反应时间也有延长。苯胺聚合是以头-尾连接形式进行,且中间产物由高氧化态逐渐转变成中间氧化态。     

硫酸镁的临床新用途

镁是人体必需元素之一。镁参与生命活动的所有重要方面,是细胞新陈代谢中各种酶系统的重要活化剂。硫酸镁为泻药和利胆药,近年来发现其具有治疗肺炎、肺心病、冠心病、高血压、胃十二指肠溃疡、急性腹泻、急性肾炎、偏头痛、破伤风和婴儿手足搐搦症等新用途。常用２５％硫酸镁１０～４０ｍＬ,用５％葡萄糖注射液稀释成１％浓度缓慢静滴。