Norditerpenoid Alkaloids from the Roots of Aconitum hemsleyanum Pritz.var.Pengzhouense

In continuation of our studies on Aconitum hemsleyanum Pritz.var. pengzhouense, two new norditerpenoid alkaloids, pengshenines A(1) and B(2),have isolated from the roots of the plants and their strucures were elucidated by 1D-and 2D-NMR.     

二芳基乙烯类光致变色材料的合成概述

由于具有多种潜在的应用价值, 光致变色化合物作为高级功能材料的研究在国内外广受关注. 在众多的有机光致变色化合物中, 二芳基乙烯特别是二噻吩乙烯, 由于其具有良好的热稳定性和优良的耐疲劳度而成为这类化合物的杰出代表. 近年来, 有关二芳基乙烯类光致变色化合物的各种合成及性能方面的报道已涉及到信息存储、分子开关、逻辑电路、液晶显示、磁性材料等众多领域. 主要是从有机合成的角度, 对这类材料的合成进行了较为全面的概括, 对各种合成方法分别加以介绍和分析, 对其发展趋势予以探索和展望.     

Effect of carbon content on photocatalytic activity of C/TiO2 composite

A series of carbon-covered titania (CCT) were prepared via pyrolysis of sucrose highly dispersed on titania surface in flowing N₂. The samples were characterized by XRD, BET, DTA-TG, UV—Vis, and their photocatalytic properties were evaluated with two model pollutants, methylene blue (MB) and rhodamine B (RB), at room temperature. The effect of carbon content on photocatalytic activity of the C/TiO₂ composite was investigated. It was found that the effect of carbon content is different for different pollutants or different light sources. For three tested samples, under UV illumination CCT01 has the highest activity for MB photocatalytic degradation, while in the case of RB, CCT02 is the most active photocatalyst. Under visible light illumination, CCT005 has the highest activity for both MB and RB photocatalytic degradation. Translated from Chinese Journal of Catalysis, 2006, 27(1): (in Chinese)     

MnOx在ZrO2上分散状态及对CO氧化的影响

近年，氧化铝载体以其独特性能引起多方面的关注［1］．当将Pt、Rh金属担载在ZrO2上时，在金属和氧化物之间存在着强的相互作用［2，3］，从而提高了CO氧化和NO的还原性能．目前，许多作者曾对ZrO2。负载氧化铜催化剂进行了较系统的研究[4，5]：氧化锰对许多重要的催化反应有广     

甲氧羰基亚甲基三苯基胂与邻羟基芳醛,酮的反应-5,6-苯并-2-吡喃酮的合成

本文报道一种合成烃基取代5,6-苯并-2-吡喃酮的方法。甲氧羰基亚甲基三苯基胂与烃基取代的邻羟基芳醛、酮反应,首先生成α,β-不饱和酸酯,继而发生分子内环化,生成烃基取代的5,6-苯并-2-吡喃酮。     

Design, synthesis, and binding affinities of pyrrolinone-based somatostatin mimetics

[structure: see text] Tetrapyrrolinone somatostatin (SRIF) mimetics (cf. 1), based on a heterochiral (D,L-mixed) pyrrolinone scaffold, were designed, synthesized, and evaluated for biological activity. The iterative synthetic sequence, incorporating the requisite functionalized coded and noncoded amino acid side chains, comprised a longest linear synthetic sequence of 23 steps. Binding affinities at two somatostatin receptor subtypes (hsst 4 and 5) reveal micromolar activity, demonstrating that the d,l-mixed pyrrolinone scaffold can be employed to generate functional mimetics of peptide beta-turns.     

Simultaneously achieving high capacity storage and multilevel anti-counterfeiting using electrochromic and electrofluorochromic dual-functional AIE polymers

With the advent of the big data era, information storage and security are becoming increasingly important. However, high capacity information storage and multilevel anti-counterfeiting are typically difficult to achieve simultaneously. To address this challenge, herein, two electrochromic and electrofluorochromic dual-functional polymers with aggregation-induced emission (AIE) characteristics were rationally designed and facilely prepared. Upon applying voltages, the absorption and fluorescence spectra of the AIE polymers can undergo reversible changes, accompanied by variation of their color and emission. By utilizing the controllable characteristics of the polymers, dual-mode display devices were fabricated via a simple spraying technique. More interestingly, a four-dimensional color code device was constructed by adding color change multiplexing to the two-dimensional space, thereby achieving high capacity information storage. Moreover, the color code device can also be applied in the multilevel anti-counterfeiting area. The encrypted information can be dynamically converted under different voltages. Thus, the AIE polymers show great promise for applications in multidimensional information storage and dynamic anti-counterfeiting, and the design strategy may provide a new avenue for advanced information storage and high security technology.

By using electrical stimuli-responsive AIE polymers, dual-mode display devices, multidimensional information storage and anti-counterfeiting devices were constructed.     

To improve the key properties of nonlinear optical crystals assembled with tetrahedral functional building units

Nonlinear optical (NLO) crystals assembled with conventional non-π-conjugated tetrahedral functional building units (FBUs), generally referring to [PO₄] and [BO₄], usually exhibit weak nonlinearity and poor birefringence. It is currently proposed that partially substituting oxygen atoms with fluoride atoms in these FBUs could enhance these crucial properties. Hence, we investigated for the first time the NLO-related properties of NH₄BAsO₄F (ABAF), which was constructed from tetrahedral [BO₃F] and [AsO₄] FBUs, and enhancements of these properties were observed in this material, that is large second-harmonic generation (SHG) response (2 × KDP) and improved birefringence (0.03 at 1064 nm). Notably, both SHG coefficient and birefringence of ABAF exceeded those of a great majority of phosphates, sulfates, or boron phosphates and achieved a preferable balance. It is interesting that ABAF shows vast structural similarities to the typical NLO crystals Sr₂Be₂B₂O₇ (SBBO) and KBe₂BO₃F₂ (KBBF), which might be the partial reason why it showed improvement in these vital properties. This work may afford some inspiration for enhancing the key performances of NLO crystals assembled with non-π-conjugated tetrahedra.

We report a new nonlinear optical crystal assembled exclusively with tetrahedral functional building units in which enhanced birefringence (Δn) and second-harmonic generation (d_eff) were observed.     

Microfluidic adhesion analysis of single glioma cells for evaluating the effect of drugs

Cancer metastasis is one of the most serious problems for tumor therapy, which is closely related to cell adhesion and deadhesion process. Better comprehension of cell adhesion ability will benefit drug research. Here, a biomimetic microfluidic enzyme digestion method was proposed to gently measure the influence of drugs on cell-matrix adhesion ability at the single cell level.The method can selectively digest the extracellular matrix(ECM) that linked to a single cell, and the trypsin concentration around the cell is relatively uniform and constant, thus the measured cell adhesion strength should be precise. Commercially available anti-cancer agents including 5-fluorouracil(5-FU), actinomycin D(Act D), temozolomide(TMZ) and allicin were evaluated, and the data showed only TMZ and allicin can inhibit cell adhesion significantly under our experiment conditions. The influence of TMZ became more and more obvious as the increase of duration and the effect became prominent only after 6 h adhesion process, which could provide a quick evaluation of whether the drugs are effective to cancer cell(compared with Calcein-AM/PI cell viability test). The adhesion strength of U87 cells decreased when the concentration of TMZ increased, and the effect of TMZ can be effectively inhibited by adding lactic acid to culture medium, which indicated acidic tumor microenvironment could promote drug resistance of tumor cells. Different from conventional evaluation methods which focus on the drugs' influence on cellular viability or metabolism, this work provides a new perspective to study the effect of drugs, which is helpful to enrich the drug evaluation system.     

A membrane separation technique for optimizing sample preparation of MALDI-TOF MS detection

Here, we report a new method based on the combination of membrane separation technology and nanomaterial to rapid detection of peptides and protein with MALDI-TOF MS. This method shows advantages as it can inhibit the heterogeneous of sample spot and enhance the target molecular signal intensity.