Iridium complex of porphycene: a new member of metalloporphycene

Iridium(Ⅲ) porphycene complex was synthesized and structurally characterized for the first time. The introduction of the posttransition iridium(Ⅲ) ion not only significantly enhances the absorption intensity at the end of visible region, but also displays efficient singlet oxygen quantum yield(76%), which is applicable for photodynamic therapy in living cells.     

功能化医用聚氨酯弹性体制备及生物医用研究进展※

热塑性聚氨酯(TPU)弹性体因其良好的可加工性、机械性能和生物安全性而被广泛应用于生物医学领域. 绝大部分TPU都由大分子二元醇软段以及异氰酸酯和小分子扩链剂形成的硬段组成, 这两者分别提供基体的弹性与链网络的框架刚性. 小分子扩链剂二元醇/胺和二异氰酸酯的结构设计是构建功能化TPU的主要途径. 研究者根据特定临床应用场景和使用需求, 设计和制备相应的功能化单体, 并开发出相应的医用TPU. 本综述首先介绍了大分子二元醇、二异氰酸酯以及扩链剂的种类以及各自的特点, 对其特有的微相分离结构做了介绍, 并明晰了化学/物理结构与最终性能的关系. 随后, 综述了国内外TPU在生物医学领域的研究进展和应用, 重点阐述了医用TPU在抗菌、抗凝血、耐水解耐氧化、自愈性以及可降解等方面的发展情况. 最后, 通过总结和分析医用TPU及其器械评价的相关标准, 提出了产业化应用的关键问题, 并展望了医用TPU未来的发展方向.     

Methanol facilitated synthesis of 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones from nitroallylic acetates and thiourea

A novel efficient strategy for the synthesis of rare 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones is described. Methanol, solvent for this one-step reaction, participated in this seven-membered ring closure reaction between nitroallylic acetates and thiourea. The thiourea itself also served as a base in this reaction. A possible mechanism for the reaction is proposed.     

Design and experimental verification of multiple delay feedback control for time-delay nonlinear oscillators

This study aims to show that a multiple delay feedback control method can stabilize unstable fixed points of time-delay nonlinear oscillators. The boundary curves of stability in a control parameter space are derived using linear stability analysis. A simple procedure for designing a feedback gain is provided. The main advantage of this procedure is that the designed controller can stabilize a system even if the controller delay times are long. These analytical results are experimentally verified using electronic circuits.     

Binding studies of costunolide and dehydrocostuslactone with HSA by spectroscopy and atomic force microscopy

Human serum albumin (HSA), a major plasma protein and plasma-derived therapeutic, interacts with a wide variety of drugs and native plasma metabolites. In this study the interactions of costunolide (CE) and dehydrocostuslactone (DE) with HSA were investigated by molecule modeling, atomic force microscopy (AFM), and different optical techniques. In the mechanism discussion, it was proved that fluorescence quenching of HSA by both of the drugs is a result of the formation of drug-HSA complexes. Binding parameters for the reactions were determined according to the Stern-Volmer equation and static quenching. The results of thermodynamic parameters ΔG⁰, ΔH⁰, and ΔS⁰ at different temperatures indicated that hydrogen bonding interactions play a major role in the drug-HSA associations process. The binding properties were further studied by quantitative analysis of CD, FTIR, and Raman spectra. Furthermore, AFM results showed that the dimension of HSA molecules became more swollen after binding with the drugs.     

Yeast Synthetic Biology for the Production of Lycium barbarum Polysaccharides

The fruit of Lycium barbarum L. (goji berry) is used as traditional Chinese medicine, and has the functions of immune regulation, anti-tumor, neuroprotection, anti-diabetes, and anti-fatigue. One of the main bioactive components is L. barbarum polysaccharide (LBP). Nowadays, LBP is widely used in the health market, and it is extracted from the fruit of L. barbarum. The planting of L. barbarum needs large amounts of fields, and it takes one year to harvest the goji berry. The efficiency of natural LBP production is low, and the LBP quality is not the same at different places. Goji berry-derived LBP cannot satisfy the growing market demands. Engineered Saccharomyces cerevisiae has been used for the biosynthesis of some plant natural products. Recovery of LBP biosynthetic pathway in L. barbarum and expression of them in engineered S. cerevisiae might lead to the yeast LBP production. However, information on LBP biosynthetic pathways and the related key enzymes of L. barbarum is still limited. In this review, we summarized current studies about LBP biosynthetic pathway and proposed the strategies to recover key enzymes for LBP biosynthesis. Moreover, the potential application of synthetic biology strategies to produce LBP using engineered S. cerevisiae was discussed.     

ChemInform Abstract: Pressure‐Induced Structural and Electronic Transition in Sr2ZnWO6 Double Perovskite.

Polycrystalline Sr₂ZnWO₆ is prepared by staged calcination of stoichiometric amounts of SrCO₃, ZnO, and WO₃ in air (Al₂O₃ crucible, 1.     

Fouling-resistant behavior of liquid-infused porous slippery surfaces

Marine economy is seriously affected by marine biofouling,which has plagued people for thousands of years.Although various strategies have been developed to protect artificial surfaces against marine biofouling,cost-effective biofouling-resistant coating is still a goal in pursue.Herein,a cost-effective liquid-infused porous slippery surface (LIPSS)was facilely prepared by using poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer to form microsphere surfaces,followed by infusing fluorocarbon lubricants into the porous structure.The as-prepared slippery surfaces were characterized by static water contact angle,sliding velocity and sliding angle analysis.We also investigated the adhesion behavior of Escherichia coli (E.coli) and limnetic algae on different surfaces.It is confirmed that the slippery surfaces have better anti-biofouling properties than the porous SEBS reference.This cost-effective approach is feasible and easily produced,and may potentially be used as fouling-resistant surfaces.     

Fully automatic exposed and in‐syringe dynamic single‐drop microextraction with online agitation for the determination of polycyclic musks in surface waters of the Pearl River Estuary and South China Sea

An automatic exposed and in‐syringe dynamic single‐drop microextraction method (SDME) for the determination of five polycyclic musks in natural waters was developed using gas chromatography with mass spectrometry. Online agitation was first introduced to the automatic SDME with a magnetic mixer fixed to the bottom of the sample tray of the autosampler. A high enrichment factor (110 ～182) for the target analytes could be achieved after several parameters that affected the microextraction were optimized. The recoveries were between 84.9 and 119.5%, while the limit of detection ranged from 3.4 to 11 ng/L with relative standard deviation < 11.1% for the polycyclic musks. This new SDME mode is fully automatic with great convenience, high enrichment and good reproducibility, and no human intervention. The proposed method was, therefore, successfully applied to determine the polycyclic musks in 31 surface sea waters that were collected from the Pearl River Estuary and the South China Sea. Most polycyclic musks could be detected with the total concentrations ranging from 58.9 to 528.5 ng/L. By using spatial interpolation method of ordinary kriging, the most contaminated area was found near the cities of Dongguan and Guangzhou with local discharge via the major rivers.