我国银行间债券市场流动性问题探析

本文运用换手率和变现时长等指标来考察我国银行间债券市场的流动性现状,分别从交易成本、产品因素、制度因素等三个方面分析了制约我国商业银行债券市场流动性的原因,并提出相应的政策建议

Correlation between Voice Handicap Index-10(VHI-10) and Voice Acoustic Analysis in Patients with Unilateral Arytenoid Dislocation

目的探讨嗓音声学分析与简化嗓音障碍指数(voice handicap index-10,VHI-10)用于单侧环杓关节脱位患者嗓音质量评估的临床意义及其相关性。方法对36例(男性20例,女性16例)单侧环杓关节脱位患者和50例(男性25例,女性25例)嗓音正常者进行嗓音声学分析和VHI-10调查。嗓音声学参数包括基频微扰(jitter)、振幅微扰(shimmer)、基频(F0)和噪谐比(NHR);VHI-10调查记录总分值Tvh。结果 (1)单侧环杓关节脱位组的jitter、shimmer、NHR、F0和VHI-10与对照组比较差异均有统计学意义。(2)男性单侧环杓关节脱位组患者嗓音声学分析参数jitter、shimmer、NHR和F0与VHI-10之间无相关性;女性患者组,除F0与VHI-10之间无相关性外,其余3个jitter、shimmer、NHR与VHI-10之间均有相关性,相关系数分别为0.556,0.719和0.793。结论计算机声学分析的各项参数均可作为衡量单侧环杓关节脱位患者嗓音音质的有效参数。单侧环杓关节脱位对患者生活质量具有显著影响,且不同性别的患者其生活质量所受影响的程度不同。Objective To study the relationship between voice acoustic analysis(VAA)and voice handicap index-10(VHI-10) in patients with unilateral arytenoid dislocation and to investigate the characteristic of the VHI-10. Methods 50 subjects with normal voice and 36 patients with unilateral arytenoid dislocation were tested by VAA and VHI-10. VAA include jitter、shimmer、F0 and NHR. The total score of VHI-10 recorded as Tvh. Results(1)There were significant differences in jitter、shimmer、F0、NHR and VHI-10 between unilateral arytenoid dislocation group and control group.(2)There was no correlation between all acoustic parameters and VHI-10 in male. All acoustic parameters except F0 had significant correlations with VHI-10 in female and the correlation coefficient were 0.556, 0.556 and 0.719. Conclusion The acoustic parameters are effective parameters to measure the voice quality of patients with unilateral arytenoid dislocation. Unilateral arytenoid dislocation significantly affects the quality of life in patients. However, the different of sex will result in the effect on the quality of life in patients inconsistently.国家自然科学基金资助项目(No.81371080

结构匹配酞菁缔合物红区荧光探针在纳克级肝素测定中的应用

肝素是一种聚阴离子生物活性多糖,具有重要的临床价值,简便快速、特异性高的分析方法的研发一直受到重视。基于分子缔合作用原理,构建了酞菁离子缔合物荧光探针,并籍此建立了肝素高特异、高灵敏的荧光分析新方法,分析浓度可达纳克级。发射强红色荧光的四磺基铝酞菁（AlS4Pc）是一种带负电的金属酞菁荧光化合物,研究发现,母体结构相同、荷电相反的阳离子铜酞菁化合物阿利新蓝（Alcian blue 8 GX）对AlS4Pc具有高效荧光猝灭作用。由于二者均具有大平面的酞菁母体,但电性相反,分子结构有着高度的匹配性,易于通过静电作用、平面疏水作用等分子间力而形成强的缔合作用,生成近乎无荧光的缔合物。据此现象构建了AlS4Pc-Alcian blue 8 GX缔合物荧光探针。进一步的糖类物质考察、筛选实验显示,具有强负电性的阴离子生物多糖可以使AlS4Pc-Alcian blue 8 GX缔合体系的荧光发生不同程度的恢复,重新发出AlS4Pc的荧光,其中尤以肝素存在下的荧光恢复行为最为显著,且恢复程度与肝素的浓度呈正相关。这是因为肝素带有大量磺酸根阴离子,对AlS4Pc构成强的竞争结合（Alcian blue 8GX）的作用,导致AlS4Pc从缔合体系中游离出来,体系荧光得以恢复。基于这一发现,研究建立了一种高灵敏、高特异性测定肝素的荧光增强分析法。考察了体系的分子光谱（荧光光谱和吸收光谱）行为以探讨缔合物形成和反应体系荧光恢复的作用机理;对反应参数（包括pH、反应温度、反应时间、 AlS4Pc以及Alcian blue 8 GX的用量等）进行了优化;在最佳条件下,方法的线性回归方程y=1.08x+58.62,工作曲线线性区间为6.0～600.0 ng·mL-1,检测限为5.7 ng·mL-1;提出了简便实用的样品前处理方法（极性有机溶剂沉淀分离法）以解决实际样品测定时存在偏差的问题;此外,较为全面地考察了多种类物质（常见阴、阳离子、小分子、表面活性剂及生物大分子）对肝素测定的干扰行为;本法应用于实际样品（肝素钠注射液）的测定,取得了较为满意的结果。开拓了酞菁类化合物作为分子光谱探针在分析科学中的应用。福建省属公益类科研院所基本科研专项重点项目(2017R1036-2)资

Simultaneous determination of 7 nucleosides in Asterias rollestoni using reversed-phase high performance liquid chromatography

建立了罗氏海盘车中7种核苷化合物的反相高效液相色谱分析测定方法。采用超声波辅助提取,选用两根不同的C18色谱柱串联,以甲醇和0.2%(体积分数)乙酸/水溶液为流动相梯度洗脱分离。优化的色谱条件为:柱温为室温,检测波长为260nM,流速为0.8Ml/MIn,进样量为20μl。结果表明,7种核苷化合物在一定的浓度范围内线性关系良好,次黄嘌呤和胸苷的线性范围为0.65~40Mg/l,尿苷、黄嘌呤和肌苷的线性范围为0.80~40Mg/l,胸腺嘧啶的线性范围为1.15~40Mg/l,鸟苷的线性范围为0.50~40Mg/l。样品中7种核苷化合物的加标回收率为90.00%~105.00%,相对标准偏差为0.72%~3.23%。该方法操作简便、灵敏度高、重复性好,回收率高,适用于罗氏海盘车中7种核苷类成分的同时分析,也可用于罗氏海盘车的质量控制和综合评价。A method for the simultaneous determination of 7 nucleosides in Asterias rollestoni was devel-oped using reversed-phase high performance liquid chromatography ( RP-HPLC) .Analytes were extracted by ultrasonic-assisted extraction and separated on two different C18 columns,which were connected in se-ries,under the gradient elution with the mobile phases of methanol and 0.2% ( v/v) acetic acid/water at room temperature.The chromatographic conditions were as follows: flow rate,0.8 mL/min; detection wavelength,260 nm; injection volume,20 μL.Under the optimized conditions,good linear relationships between the values of mass concentrations and the peak areas of hypoxanthine,uridine,xanthine,thy-mine,inosine,guanosine and thymidine were observed in the ranges of 0.65-40,0.80-40,0.80-40,1.15-40,0.80-40,0.50-40,and 0.65-40 mg/L,respectively.The relative standard devia-tions were around 0.72%-3.23% and the recoveries were around 90.00%-105.00%.The results showed that the developed method is sensitive,accurate and reproducible.It is suitable for the analysis of nucleosides in Asterias rollestoni with high recoveries and it is expected to be used for the quality control and evaluation of Asterias rollestoni.国家自然科学基金项目(20905017);海洋公益性行业科研专项(200705011;200805039);海洋局青年基金项目(2010140);海洋一所基本科研业务专项(GY-022008T32;2010G25);中国科学院实验海洋生物学重点实验室开放基金课

Determination of five poisonous elements in holothurian sold on the market by Microwave Digestion with ICP—MS

建立了微波消解—电感耦合等离子体质谱法测定海参中Cu,AS,Cd,Hg,Pb 5种有毒元素含量的方法,采用In元素为内标,利用其回收率对以上5种元素的测定结果进行校正,该方法变异系数(CV%)为0.2%--4.0%,In元素加标回收率为96.7%--104.5%,说明该方法灵敏度高,结果准确可信。利用该方法对10批不同市售海参中5种有毒元素含量进行了测定,结果表明10批市售海参中的AS含量均超标,部分批次海参中的Cd、Pb超标,说明市售海参确实存在有毒元素超标的问题。A method based on microwave sample digestion and inductively coupled plasma-mass spectrometry(ICP—MS) detection was established for determination of Cu,As,Cd,Hg and Pb in holothurian sold on the market.Indium was used as internal standard element to calibrate the results of determination of these five elements.Determination limits of these five elements were in the range of 0.006～0.063 μg/g,coefficient of variation(CV%)were in the range of 0.2%～4.0%,and the recovery of In was in the range of 96.7%～104.5%.The method has been applied to determine the five poisonous elements in ten holothurian samples sold on the market.The results indicated that the over-standard problem of poisonous elements in holothurian sold on the market existed.The content of total arsenic was over standard in all the ten samples,but the over standard problem of lead and cadmium was only found in part of the samples.国家自然科学基金(20675021);中国近海海洋综合调查与评价908专项(908-02-05-04)资

Primary Exploration on Quality Evaluation of Holothurian Sold on the Market by HPLC Fingerprint

以10批不同产地刺参HPlC指纹图谱中的6个共有峰为评价指标,结合相似度分析,对不同刺参质量进行评价和检验。结果表明:不同批次刺参样品的6个色谱峰在指纹图谱分析过程中色谱行为相同,峰面积大,特征性强,能反映刺参的固有化学特征。结合相似度分析,可用于刺参质量评价。An optimized high performance liquid chromatography (HPLC) method was developed for the analysis of holothurian and the HPLC fingerprint was established from 10 batches of the holothurians from different habitats.The HPLC fingerprint showing 6 common characteristic peaks was used to explore the quality evaluation of holothurian and distinguish from the fakes with the similarity analysis.This method is accurate and reliable,providing a scientific basis for the quality control of holothurian and can be used to evaluate the quality of holothurian sold on the market.我国近海海洋综合调查与评价908专项(908-02-05-04):海洋药用生物资源评价和《中华海洋本草》编纂;海洋一所基本科研业务专项(GY-022008T32):海洋绿藻活性成分分析、鉴

In-Situ FTIR Spectroscopic Studies of Electro Oxidation of Ethanol in Alkaline Media at a nm-Pt/GC Electrode

运用电化学循环伏安和原位FTIR反射光谱研究了碱性介质中乙醇在nm Pt/GC电极上的氧化。结果表明 ,主要产物是CH3 COO-,仅存在少量乙醛 ,未检测到CO谱峰。与酸性介质中乙醇氧化的双途径机理不同 ,碱性介质中乙醇的氧化未经过解离吸附的中间步骤。The electro oxidation of ethanol on a nm Pt/GC electrode in alkaline solutions was investigated by using cyclic Voltammetry and in situ FTIR spectroscopy.The results demonstrated that the main product of ethanol oxidation was CH 3COO -,only small quantity of CH 3CHO was determined simultaneously.In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media,the oxidation of ethanol in alkaline media was revealed via the intermediate process of dissociative adsorption.国家自然科学基金项目!(2 98330 60 );; 国家教育部科学技术重点研究项目!(991 77)资

In-situ FTIR spectroscopic studies of electro oxidation of ethanol in alkaline media at a nm-Pt/GC electrode

The electro-oxidation of ethanol on a nm-Pt/GC electrode in alkaline solutions was investigated by using cyclic Voltammetry and in-situ FTIR spectroscopy. The results demonstrated that the main product of ethanol oxidation was CH3 COO-, only small quantity of CH3 CHO was determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media was revealed via the intermediate process of dissociative adsorption