Recent advances in electrochemical sensors for antibiotics and their applications

The abuse of antibiotics will cause an increase of drug-resistant strains and environmental pollution,which in turn will affect human health.Therefore,it is important to develop effective detection techniques to determine the level of antibiotics contamination in various fields.Compared with traditional detection methods,electrochemical sensors have received extensive attention due to their advantages such as high sensitivity,low detection limit,and good selectivity.In this mini review,we summarized the latest developments and new trends in electrochemical sensors for antibiotics.Here,modification methods and materials of electrode are discussed.We also pay more attention to the practical applications of antibiotics electrochemical sensors in different fields.In addition,the existing problems and the future challenges ahead have been proposed.We hope that this review can provide new ideas for the development of electrochemical sensors for antibiotics in the future.     

Phenoxazine-based supramolecular tetrahedron as biomimetic lectin for glucosamine recognition

The design and synthesis of a phenoxazine-based metal-organic tetrahedro n(Zn_4L_4) as biomimetic lectin for selectively recognition of glucosamine(GlcN) was reported.Different from the free phenoxazinebased ligand(L),Zn_4L_4 displayed the highest fluorescent intensity enhancement efficiency toward GlcN over other related natural mono-and disaccharides.Fluorescence titration demonstrated a 1:1 stoichiometric host-guest complex was formed with an association constant about 4.03 × 10~4 L/mol.~1H NMR spectroscopic studies confirmed this selectivity resulted from the multiple hydrogen bonding interactions formed between GlcN and Zn_4L_4.The present results suggested that rational arrangement of recognition sites in the confined space of metal-organic cage is crucial for the selectivity toward target guests.     

Comprehensive Mechanism for CO Electroreduction on Dual-Atom-Catalyst-Anchored N-Doped Graphene

Carbon neutrality has drawn increasing attention for realizing the carbon cyclization and reducing the greenhouse effect. Although the C1 products, such as CO, can be achieved with a high Faraday efficiency, the targeted production of C2 fuels as well as the mechanism have not been systematically investigated. In this work, we carry out a first-principles study to screen dual-atom catalysts (DACs) for producing C2 fuels through the electrocatalytic carbon monoxide reduction reaction (e-CORR). We find that methanol, ethanol and ethylene can be produced on both DAC−Co and DAC−Cu, while acetate can be achieved on DAC−Cu only. Importantly, methanol and ethylene are preferred on DAC−Co, while acetate and ethylene on DAC−Cu. Furthermore, we show that the explicit solvent can enhance the adsorption and influence the protonation steps, which subsequently affects the protonation and dimerization behavior as well as the performance and selectivity of e-CORR on DACs. We further demonstrate that the C−C coupling is easy to be formed and stabilized if the Integrated Crystal Orbital Hamilton Population (ICOHP) is low because of the low energy barrier. Our findings provide not only guidance on the design of novel catalysts for e-CORR, but an insightful understanding on the reduction mechanism.     

电纺纤维在超级电容器中的应用

对高性能超级电容器不断增长的需求促进了电极隔膜和电极材料的快速发展.静电纺丝法制备的纳米纤维具有较高的孔隙率、较好电化学活性、较大的表面积以及良好的结构稳定性等优点,已被广泛应用于超级电容器的隔膜和电极材料.本文简要综述了近年来电纺纳米纤维在超级电容器用隔膜和电极材料的研究进展;着重讨论了通过静电纺丝和其他后处理方法制...     

Development of New Thiophene-Containing Triaryl Pyrazoline Derivatives as PI3Kγ Inhibitors

A series of new thiophene-containing triaryl pyrazoline derivatives, 3a–3t, were synthesized and evaluated regarding PI3K inhibition activity and anti-tumor potency based on a trial of introducing significant moieties, including pyrazoline and thiophene, and simplifying the parallel ring structures. Most of the tested compounds indicated potent PI3K inhibitory potency, with this series of compounds showing more potency for PI3Kγ than PI3Kα. The top hit 3s seemed more potent than the positive control LY294002 on inhibiting PI3Kγ (IC₅₀ values: 0.066 μM versus 0.777 μM) and more selective from PI3Kα (Index values: 645 versus 1.74). It could be inferred that the combination of para- and meta-, as well as the modification of the electron-donating moieties, led to the improvement in potency. The anti-proliferation inhibitory activity and the enzymatic inhibition potency indicated consistent tendencies. The top hit 3s could inhibit the phosphorylation of Akt by inhibiting PI3K through the PI3K-Akt-mTOR pathway. The molecular docking simulation indicated that the binding pattern of 3s into PI3Kγ was preferable than that of PI3Kα, with more hydrogen bond, more π-involved interactions, and fewer π-sulfur interactions. The information in this work is referable for the further development of selective inhibitors for specific isoforms of PI3K.     

JEE—4x型真空镀膜仪功能扩展

报道了对ＪＥＥ－４ｘ型真空镀膜仪蒸发装置的改进以及建立蒸发材料回收装置的具体方法，并介绍了改进后该仪器在高分辨扫描电镜样品制备上的应用实例．实验证明，上述改进不但扩展了ＪＥＥ—４ｘ型真空镀膜仪的制样功能又节省了蒸发材料，集中了离子溅射法及常规高真空镀膜法的优点，完全满足ＳＥＭ样品的分析要求，该方法简单易操作．     

新型汽车发动机油用添加剂的研究进展

本文介绍了汽车发动机油用添加剂尤其是多功能添加剂的发展概况、作用机理、种类、结构及应用效果，并对未来润滑油添加剂的发展方向提供了一些参考，为我国润滑油品的高档化发展提出了几点想法。     

A rapid and accurate method for the determination of strontium-90 in environmental soil

A rapid and accurate method for the determination of⁹⁰Sr in environmental soil has been developed; the procedure includes soil leaching by hydrochloric acid, oxalate precipitation, decontamination from²¹⁰Bi, separation by HDEHP extraction chromatography column, yttrium oxalate precipitation and -counting. The interference of²¹⁰Bi was found and studies have been made for the decontamination of⁹⁰Y from²¹⁰Bi by Bi₂S₃ precipitation giving a decontamination factor of 1.05·10³. The analytical results obtained by the improved rapid method for 12 soil samples were comparable to that obtained by a previous method within a relative error of 20%. Studies of vertical distribution of⁹⁰Sr in an environmental soil profile have shown that 90% of the⁹⁰Sr deposits in the 30 cm surface soil of the earth with a highest concentration of 3.40 Bq/kg. When 50 g soil was analyzed, the yield of yttrium was 73±17% with a detection limit of 0.26 Bq/kg.     

微波在柴油机滤烟器催化再生中的应用 Ⅰ.滤烟器在氮气中的微波加热温升行为

利用柴油机台架装置及微波加热装置考察了柴油机催化滤烟器的微波加热温升效应． 结果表明,过滤体上捕集的烟碳量对催化滤烟器在氮气中的微波加热温升至关重要,烟碳量的微小增加,可引起滤烟体温度的显著升高． 另外,当微波加热过程中隔离氧气时,滤烟体上出现了明显的金属氧化物催化剂被碳还原的现象．     

遗传光度法用于地质样品中多组分同时测定

将遗传算法（ＧＡ）用于地质样品中１５个稀土元素同时测定,分析结果与ＩＣＰ法进行了比较,大多数组分浓度的相对误差小于１０％,个别小于１６．２％,初步验证,遗传算法可以摆脱对校准模型的依赖。文中还讨论了变异概率,交配概率,种群数大小等因素的影响。