A sensitive and selective HPLC–MS3 method for therapeutic drug monitoring of meropenem and its validation by comparison with HPLC–MS2 methods

Meropenem, a representative β-lactam antibiotic, is widely used to treat complicated and serious infections. Therefore, it is of great significance to monitor the plasma drug concentration for individualized antimicrobial therapy. This study first describes the development and validation of high-performance liquid chromatography–tandem mass spectrometry cubed method for monitoring meropenem in human plasma. Protein precipitation with methanol and a chromatographic analysis time of 7 min make this method simple and of high throughput. Meropenem was extracted from human plasma with recoveries >94.1%. Calibration curves were linear (R² > 0.995) in the concentration range of 0.5–50 μg/mL. Overall accuracy and precision did not exceed 8.0% as well as no significant matrix effect was observed. The novelty of this method is that the triple-stage mass spectrometry technology improves the selectivity and sensitivity. A comparison of the presented method and traditional liquid chromatography–tandem mass spectrometry method was assessed in 44 patients treated with meropenem and Passing–Bablok regression coefficients and Bland–Altman plots showed that no significant difference between the two methods. So the triple-stage mass spectrometry method developed in this study is appropriate and practical for the monitor of meropenem in the daily clinical laboratory practice.     

Dual recognition strategy for ultra-sensitive fluorescent detection of Hg2+ at femto-molar level based on aptamer functionalized sulfur quantum dots

In the present study, a dual recognition strategy for ultrasensitive detection of Hg²⁺ was successfully developed for the first time based on aptamer functionalized sulfur quantum dots (Apt-SQDs). The developed Apt-SQDs not only retained the good fluorescence properties of quantum dots but also overcame the problem of poor selectivity of SQDs for heavy metal ions. This system used the dual recognition strategy, including the combination of S_x^2? and Hg²⁺ and T-Hg²⁺-T structures to excellently identify and capture Hg²⁺, and an ultrahigh sensitivity fluorescent aptasensor was fabricated. The fluorescent aptasensor had a good response to Hg²⁺ at concentrations ranging of 10^?15 to 10^?7 M with an ultralow limit of detection of 0.3 fM, and the response to other metal ions was far less than that to Hg²⁺. It was successfully applied to detect Hg²⁺ in nearby environmental water samples (tap water, lake water and river water) with a good recovery rate. Moreover, portable test papers that would be useful for Hg²⁺ monitoring in environmental water were designed. The dual recognition strategy not only achieves ultrasensitive fluorescent detection of Hg²⁺ but also provides a new insight into the further expansion of the application of SQDs.     

回归知识本原 构建生命课堂——以“常见物质的检验”为例

以“常见物质的检验”的教学为例,运用化学史料帮助学生自主建构知识体系,促进学生追寻知识本原,实现思维进阶,发展核心素养,并阐述运用化学史料构建高中化学生命课堂的实施策略。     

突发公共卫生事件健康教育基本策略探讨

突发公共卫生事件一直是政府组织十分关注的问题。当前,在公共卫生事件出现高频率的发生几率后,健康教育工作已占据着越来越重要的地位。从宏观角度来说,突发公共卫生事件是一个涵盖范围十分广泛的事件内容,其事件包含了多个可预测与不可预测的突发状况,也包含了任何地点、任何社会群体以及任何事件当中,因此在健康教育上,需从宏观范围进行全面计划,以系统式方式对各个突发公共卫生事件做出针对性教育,且对教育内容作出可行性评估,切实保障健康教育对突发公共卫生事件有一定的作用及影响力。对此,为进一步探讨该话题,针对突发公共卫生事件健康教育基本策略展开详细探讨。     

Phenanthroline-fluorescein molecular hybrid as a ratiometric and selective fluorescent chemosensor for Cu2+ via FRET strategy: synthesis,computational studies and in vitro applications

A FRET-based chemosensor L containing donor phenanthroline and acceptor fluorescein moiety was designed, synthesised and characterised for the ratiometric fluorescent detection of Cu²⁺ in organo-aqueous solution. Probe L showed high selectivity and excellent sensitivity towards Cu²⁺ ions by exhibiting both colorimetric and fluorometric changes due to opening of the spirolactum ring of fluorescein upon complexation with Cu²⁺. In presence of Cu²⁺ ions, probe L formed L-Cu²⁺ complex in 1:1 stoichiometric fashion which is established on the basis of Job’s plot and mass spectroscopy. We also performed DFT computational studies to know the binding nature and coordination feature of the complex. Furthermore, fluorescence imaging studies revealed that probe L was cell permeable and could be used to detect intracellular Cu²⁺ in living cells.     

[4 1]及[3 2]会聚式四氢呋喃环合成策略在天然产物全合成中的应用进展

四氢呋喃环广泛存在于具有生物活性的天然产物结构当中,立体选择性地构筑四氢呋喃环往往成为这些天然产物全合成研究中的关键。本文归纳了已有全合成报道中的四氢呋喃环成环策略,以实例展示了其中的会聚式合成策略在近年的发展。相比于直线型的分子内关环策略,以[4+1]、[3+2]为代表的会聚式四氢呋喃关环策略往往能够使全合成的整体路线更加简洁高效,更符合全合成研究领域的发展趋势。     

Decoupled schemes for unsteady MHD equations. I. time discretization

In this article, a time discretization decoupled scheme for two‐dimensional magnetohydrodynamics equations is proposed. The almost unconditional stability and convergence of this scheme are provided. The optimal error estimates for velocity and magnet are provided, and the optimal error estimate for pressure are deduced as well. Finite element spatial discretization and numerical implementation are considered in our article (Zhang and He, Comput Math Appl 69 (2015), 1390–1406). © 2017 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 956–973, 2017     

A note on functional a posteriori estimates for elliptic optimal control problems

In this work, new results on functional type a posteriori estimates for elliptic optimal control problems with control constraints are presented. More precisely, we derive new, sharp, guaranteed, and fully computable lower bounds for the cost functional in addition to the already existing upper bounds. Using both, the lower and the upper bounds, we arrive at two‐sided estimates for the cost functional. We prove that these bounds finally lead to sharp, guaranteed and fully computable upper estimates for the discretization error in the state and the control of the optimal control problem. First numerical tests are presented confirming the efficiency of the a posteriori estimates derived. © 2016 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 403–424, 2017