Developing LC–MS/MS methods to quantify rivaroxabanin human plasma and urine: Application to therapeutic drug monitoring

Rivaroxaban is an oral anticoagulant directly inhibiting the activity of Factor Xa, which is widely used for the prophylaxis of thromboembolic disorders. Therapeutic drug monitoring (TDM) is required during therapy for individual dosage adjustment. This study aimed at developing a liquid chromatography/tandem mass spectrometry method that was suitable for rivaroxaban TDM in human plasma and urine and exploring the feasibility of urine drug monitoring in medical care. A 3 min run time of the LC–MS/MS methods was established by employing an Acquity UPLC BEH C₁₈ (2.1 × 50 mm, 1.7 μm) column using gradient elution of 10 mmol/L ammonium acetate containing 0.1% formic acid–0.1% formic acid acetonitrile as a mobile phase at a flow rate of 0.4 ml/min with calibration ranges of 0.5–400 and 10–10,000 ng/ml for human plasma and urine, respectively. Rivaroxaban was detected on a triple quadrupole tandem mass spectrometer with an electrospray ionization source in positive ion mode. The methods showed good linearity within the calibration range. The precision and accuracy, matrix effect, extraction recovery and stability in both human matrices were all validated and meet the international guideline requirements. These validated methods were successfully applied to support the TDM of an aged patient receiving rivaroxaban for therapy.     

Facile synthesis of micrometer FeS/PVP architectures with the aid of thiourea

Micrometer-sized flowerlike FeS/poly(vinyl pyrrolidone)(PVP) architectures were synthesized by solvothermal process with the aid of thiourea, in which PVP may serve as soft templates. The FeS/PVP flowers have uniform morphologies with an average diameter of 5 μm, made of several nanopetals. The formation of FeS/PVP flowers is a new kinetic control process. In this process, thiourea molecules would be decomposed to produce “gas bubble”, and the “gas bubble” could make PVP chain segment rearrange along exterior force, resulting in the morphology evolution. The higher “gas bubble” pressure would produce 3D flowers, and the lower pressure would give a hollow structure. The evolution process from particles to 3D flowers is observed for the first time. In addition, the hollow FeS/PVP and Cu₂S/PVP spheres are also obtained by this technique.     

Pluronic P123 assisted synthesis of hollow InSn/In2O3 hybrid nanoparticles by solution dispersion

A detailed analysis of the optimum regimes of pulsed current metal electrodeposition into pores of porous anodic alumina PAA is presented. A simple model based on cathodic and anodic current transients is developed. The model is based on a simplified equivalent circuit consisting of two capacities related to the barrier and porous parts of porous anodic alumina. Nanowires of Cd, Zn, In, Ni, Co, Ag, and Cu were embedded into PAA by pulsed electrodeposition using an asymmetric rectangular ac signal. Deposited metal nanowires were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical spectroscopy, Auger electron spectroscopy (AES), and X-ray diffractometry (XRD).     

4-溴苯甲醚用作锂离子电池过充保护添加剂的研究

通过在锂离子电池电解液中添加4-溴苯甲醚(4-Bromoanisole, 简称4BA)来提高锂离子电池的过充保护能力. 对电池分别进行了过充实验、循环伏安扫描、红外光谱分析、交流阻抗和容量特性测试, 实验结果表明, 在1 mol•L－1 LiPF6/EC＋DEC＋DMC(质量比1/1/1)中添加5% 的4BA(质量分数)时, 当外加电压为4.4 V(相对于Li/Li＋)时, 4BA开始发生电聚合反应且生成高分子聚合物膜, 使电池内阻增大而阻止电压的升高, 从而使电池处于比较安全的状态. 该体系正常充放电过程中, 添加5%的4BA对电池容量特性基本没有影响, 4BA 的防过充机理为阻断机理.     

无机-有机杂化聚合物电解质的制备与电化学性能

以有机改性聚硅氧烷为单体加入液态电解质通过紫外光辐射固化制备了无机有机杂化聚合物电解质.含有丙烯酸酯端基的有机改性聚硅氧烷单体是通过正硅酸甲酯(TMOS)的水解缩合反应产物与丙烯酸2羟乙酯(HEA)进行脱甲醇反应合成的.它是一种多官能团单体,其结构通过核磁共振氢谱(1HNMR)分析、红外光谱(FTIR)分析及二氧化硅分析进行了表征,分子式可表达为SiO1.143(OH)0.016(OCH3)1.339(OCH2CH2OCOCHCH2)0.357.无机有机杂化聚合物电解质的电化学性能通过交流阻抗和循环伏安法进行了表征.其离子电导率随着液态电解质含量的增大而提高,当液态电解质含量为85wt%时,电导率在22℃为5.5×10-3Scm-1,在-23℃也能达到1.1×10-3Scm-1.界面电阻经过开始2天的增大后达到稳定,电化学稳定窗口超过5.0V,不锈钢电极上锂的电化学沉积与剥离循环可逆性很高.     

欠膨胀高速射流的压力均一化过程

发展了分析欠膨胀高速湍流射流近场特性的数值,计算了不同背压比条件下声速喷管出口附近膨胀区的激波胞格结构,揭示了压力一化过程的的机制。     

小波变换在随机海浪及相关课题中的应用与前景

扼要介绍了小波变换的基本原理及其信号处理功能,综述了应用这一技术处理非平稳过程随机海浪,确定波群和异常波特性,判断波浪破碎,进行入反射分离,分析海洋和湖泊流场以及研究岸滩演变的时空变化过程与气象、海象的相关关系等方面的研究成果.讨论了这一技术在波浪动力特性认识、随机海浪的实验室模拟、波浪与建筑物相互作用研究方面的应用前景.      

A high‐order alternating direction implicit method for the unsteady convection‐dominated diffusion problem

A high‐order alternating direction implicit (ADI) method for solving the unsteady convection‐dominated diffusion equation is developed. The fourth‐order Padé scheme is used for the discretization of the convection terms, while the second‐order Padé scheme is used for the diffusion terms. The Crank–Nicolson scheme and ADI factorization are applied for time integration. After ADI factorization, the two‐dimensional problem becomes a sequence of one‐dimensional problems. The solution procedure consists of multiple use of a one‐dimensional tridiagonal matrix algorithm that produces a computationally cost‐effective solver. Von Neumann stability analysis is performed to show that the method is unconditionally stable. An unsteady two‐dimensional problem concerning convection‐dominated propagation of a Gaussian pulse is studied to test its numerical accuracy and compare it to other high‐order ADI methods. The results show that the overall numerical accuracy can reach third or fourth order for the convection‐dominated diffusion equation depending on the magnitude of diffusivity, while the computational cost is much lower than other high‐order numerical methods. Copyright © 2011 John Wiley & Sons, Ltd.     

PS-TiO2 复合纳米微球的表征及摩擦学行为

采用化学法合成了ＰＳ－ＴｉＯ２复合纳米微球，并对其进行了ＴＥＭ、ＦＴＩＲ、ＴＧＡ及ＤＳＣ等分析表征。将这种微球作用润滑油添加剂，在四球试验机上了它的减摩抗磨性能，同时又对磨斑表面进行了Ｘ射线光电子能谱分析）ＸＰＳ）。研究表明：这种添加剂有良好的抗磨性能。并在摩擦表面形成由ＴｉＯ２、Ｆｅ２Ｏ３以及有机碎片所组成的边界润滑膜。