Comparative study on the inclusion behaviour of cyclodextrin derivatives with venoruton and rutin by thin layer chromatography

The interaction of rutin and venoruton (troxerutin), with alpha-, beta- and gamma-cyclodextrin (CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and methyl-beta-cyclodextrin (M-beta-CD) was investigated by reversed-phase thin layer chromatography on polyamide plates. A mobile phase consisted of NH(4)OH; NH(4)Cl buffer solution containing various CD concentrations (pH = 9.7, 20 degrees C) was used as mobile phase. The equilibrium constants (K(f)) and the retention factor (R(f)) were determined and used to study the inclusion process. The in fluence of CDs on the solubility of rutin and venoruton was characterized by R(M) values and the increasing hydrophilicity of drugs. The results show that the inclusion capacity of cyclodextrins follows the order HP-beta-CD > M-beta-CD > beta-CD > gamma-CD, and rutin is more easily included by the studied cyclodextrins than venoruton. In addition, the thermodynamic parameters (Delta H, Delta S) for the formation of complexes were obtained from the van't Hoff equation, displaying the enthalpy-entropy compensation effect.     

SYNTHESES OF THE SOLUBLE,HIGH MOLECULAR WEIGHT AND LADDERLIKE POLYPH ENYLSILSESQUIOXAN E AND COPOLYMETHYLPHENYLSILSESQUIOXANES BY PREAMMINOLYSIS METHOD

Soluble, high molecular weight (MW) and ladderlike polyphenylsilsesquioxane (LPPSQ) and its copolymers, ladderlike random and block copolymethyiphenylsilsesquioxanes(LR-PMPSQ and LB-PMPSQ)have been prepared by preamminolysis, hydrolysis and polycondensation reactions. The preparation method can be carried out easily at the temperature below 95℃with high yield of 95 %, instead of the conventional way by using high-boiling solvent and any reaction activator or by precipitation with methanol. Three kinds of ladderlike polymers have been characterized. The MW's of the polymers reached to 10~6 without noticeable gelling. The scheme for synthetic route has been proposed.     

Crystal Structure of Trans-2-Amino-3-Cyano-4-(3',4'-Methylenedioxyphenyl)-1-Phenyl-2-Cyclopentene-r-1-ol

1INTRODUCTIONIntheearlyseventiesthreegroupsofinvestigators('--"establishedthatlow--va-lenttitanium,preparedbythereactionofstrongreducingagentsontitaniumtrichlo-rideortitaniumtetrachlorideintetrahydrofuran,canabstractoxygenfromketonesoraldehydes,leadingtotheformationofolefins.Anincreasinginterestinthereac-tioninducedbylow--valenttitaniumreagentsisobservedandalargenumberoffunc-tionalgroupscanbereducedt4--6).However,thereactionoflow-valenttitaniumreagentwith4,4--dicyano--1,3--diaryl--l-butano…     

神光-Ⅱ装置三倍频实验中靶场单元技术的改进

 主要介绍为了满足神光-Ⅱ高功率激光装置三倍频光（351nm，3ω）的物理实验要求，靶场三倍频模拟光源和瞄准监视系统两个主要单元技术的改进，即三倍频模拟光源由基频光（1 053nm，3ω）通过腔外的KTP+BBO晶体倍频获得，再经八路分光系统和主激光耦合；瞄准监视系统由透射式光学系统改进为反射式光学系统，避免原系统存在较大的色差，提高瞄准精度。     

十二烷基磺酸钠对大豆过氧化物酶活性和构象的影响

在不同的pH值体系中, 利用酶活测量、圆二色谱、荧光谱和电子吸收谱研究了十二烷基磺酸钠(SDS)对大豆过氧化物酶(SBP)活性与构象的影响情况. 在pH 2.6和4.2 的体系中, 少量的SDS分子可通过静电作用与SBP结合, 进而与SBP分子中的His169残基结合, 降低其与铁卟啉的配位能力, 使其Soret吸收带蓝移, 二级结构发生轻微的变动, 活性永久丧失. 在pH 5.2体系中, SDS和SBP分子都带负电, 由于静电排斥作用, SDS无法进入SBP的分子内部, 失去与SBP分子中His169残基结合的能力, 对SBP分子的二级结构没有影响, 仅对SBP分子的三级结构有所影响. 当SDS的浓度大于临界胶束浓度时, 由于胶束与SBP的静电排斥作用增强, 限制了铁卟啉中乙烯基的运动, 乙烯基与卟啉环的共轭程度增大, Soret 吸收带红移. 由于SBP活性可完全恢复, 此变化是可逆的.     

泡沫镍及负载型镍催化剂制备纳米碳纤维层的研究

纳米碳纤维可用在催化材料、储氢材料、及纳米电子器件等方面。本文对用泡沫镍及负载型镍催化剂催化分解乙烯或丙烯制备纳米碳纤维进行了研究。利用X射线衍射仪、物理吸附仪、扫描电镜进行了分析表征,并考察了催化剂、碳源、生长温度对纳米碳纤维生长量、形貌、结构的影响。结果表明:在生长温度450℃,乙烯流率30mL/m in的条件下,负载型镍催化剂纳米碳纤维的生长量要高出泡沫镍3~6倍,负载型镍催化剂制备的纳米碳纤维直径为40~60纳米,小于泡沫镍的情况。泡沫镍催化分解乙烯制备纳米碳纤维时,纳米碳纤维的生长量和平均直径随温度的降低而逐渐减小。纳米碳纤维在泡沫镍上的最低生长温度为420℃,在低于480℃生长纳米碳纤维时泡沫镍的骨架结构不会被破坏,由此制备的纳米碳纤维在新型结构催化材料中有很好的的应用前景。     

Crystal Structure of Human CD47 in Complex with Engineered SIRPα.D1(N80A)

Background: Targeting the CD47/SIRPα signaling pathway represents a novel approach to enhance anti-tumor immunity. However, the crystal structure of the CD47/SIRPα has not been fully studied. This study aims to analyze the structure interface of the complex of CD47 and IMM01, a novel recombinant SIRPα-Fc fusion protein. Methods: IMM01-Fab/CD47 complex was crystalized, and diffraction images were collected. The complex structure was determined by molecular replacement using the program PHASER with the CD47-SIRPαv2 structure (PDB code 2JJT) as a search model. The model was manually built using the COOT program and refined using TLS parameters in REFMAC from the CCP4 program suite. Results: Crystallization and structure determination analysis of the interface of IMM01/CD47 structure demonstrated CD47 surface buried by IMM01. Comparison with the literature structure (PDB ID 2JJT) showed that the interactions of IMM01/CD47 structure are the same. All the hydrogen bonds that appear in the literature structure are also present in the IMM01/CD47 structure. These common hydrogen bonds are stable under different crystal packing styles, suggesting that these hydrogen bonds are important for protein binding. In the structure of human CD47 in complex with human SIRPα, except SER66, the amino acids that form hydrogen bonds are all conserved. Furthermore, comparing with the structure of PDB ID 2JJT, the salt bridge interaction from IMM01/CD47 structure are very similar, except the salt bridge bond between LYS53 in IMM01 and GLU106 in CD47, which only occurs between the B and D chains. However, as the side chain conformation of LYS53 in chain A is slightly different, the salt bridge bond is absent between the A and C chains. At this site between chain A and chain C, there are a salt bridge bond between LYS53 (A) and GLU104 (C) and a salt bridge bond between HIS56 (A) and GLU106 (C) instead. According to the sequence alignment results of SIRPα, SIRPβ and SIRPγ in the literature of PDB ID 2JJT, except ASP100, the amino acids that form common salt bridge bonds are all conserved. Conclusion: Our data demonstrated crystal structure of the IMM01/CD47 complex and provides a structural basis for the structural binding interface and future clinical applications.     

Novel In Situ Growth of ZIF-8 in Porous Epoxy Matrix for Mechanically Robust Composite Electrolyte of High-Performance,Long-Life Lithium Metal Batteries

Polymer electrolytes (PEs) with high flexibility, low cost, and excellent interface compatibility have been considered as an ideal substitute for traditional liquid electrolytes for high safety lithium metal batteries (LMBs). Nevertheless, the mechanical strength of PEs is generally poor to prevent the growth of lithium dendrites during the charge/discharge process, which seriously restricts their wide practical applications. Herein, a mechanical robust ZIF-8/epoxy composite electrolyte with unique pore structure was prepared, which effectively inhibited the growth of lithium dendrites. Meanwhile, the in situ growth of ZIF-8 in porous epoxy matrix can promote the uniform flux and fast transport of lithium ions. Ultimately, the optimal electrolyte shows high ionic conductivity (2.2 × 10⁻³ S cm⁻¹), wide electrochemical window (5 V), and a large Li⁺ transference number (0.70) at room temperature. The Li||NCM811 cell using the optimal electrolyte exhibits high capacity and excellent cycling performance (83.2% capacity retention with 172.1 mA h g⁻¹ capacity retained after 200 cycles at 0.2 C). These results indicate that the ZIF-8/epoxy composite electrolyte is of great promise for the application in LMBs.     

Electrochemical Immunoassay for Tumor Marker CA19-9 Detection Based on Self-Assembled Monolayer

A CA19-9 electrochemical immunosensor was constructed using a hybrid self-assembled membrane modified with a gold electrode and applied to detect real samples. Hybrid self-assembled membranes were selected for electrode modification and used to detect antigens. First, the pretreated working electrodes were placed in a 3-mercaptopropionic acid (MPA)/β-mercaptoethanol (ME) mixture for 24 h for self-assembly. The electrodes were then placed in an EDC/NHS mixture for 1 h. Layer modification was performed by stepwise dropwise addition of CA19-9 antibody, BSA, and antigen. Differential pulse voltammetry was used to characterize this immunosensor preparation process. The assembled electrochemical immunosensor enables linear detection in the concentration range of 0.05–500 U/mL of CA19-9, and the detection limit was calculated as 0.01 U/mL. The results of the specificity measurement test showed that the signal change of the interfering substance was much lower than the response value of the detected antigen, indicating that the sensor has good specificity and strong anti-interference ability. The repeatability test results showed that the relative standard deviations were less than 5%, showing good accuracy and precision. The CA19-9 electrochemical immunosensor was used for the actual sample detection, and the experimental results of the standard serum addition method showed that the RSD values of the test concentrations were all less than 10%. The recoveries were 102.4–115.0%, indicating that the assay has high precision, good accuracy, and high potential application value.     

高炉渣非晶态含量的定量分析方法研究

通过X-ray衍射方法对高炉渣中非晶态与晶态的含量进行了定量分析研究。定量分析过程包括标准样品制备、配样与衍射以及数据处理分析。数据处理包括非晶态衍射峰及晶态峰在一定衍射角度内的积分、线性拟合与定量系数确定。提出了X-ray衍射方法所用的高炉渣标准样品的制备方法,包括100％非晶态标样和100％晶态标样。提出了由100％非晶态和100％晶态为标准样品时,高炉渣中非晶态含量的测定方法,适用于非晶态含量较高(>80%)的高炉渣的定量分析。结合数学处理和X-ray衍射结果,可得到原始高炉渣中非晶态含量和晶态含量,以及相应的比例系数,适用于非晶态含量高的高炉渣(>90%)。