Synthesis and Antiviral Bioactivity of Novel 2‐Substituted Methlthio‐5‐(4‐Amino‐2‐Methylpyrimidin‐5‐yl)‐1,3,4‐Thiadiazole Derivatives

A series of novel 2‐substituted methlthio‐5‐(4‐amino‐2‐methylpyrimidin‐5‐yl‐)‐1,3,4‐thiadiazole derivatives were synthesized, characterized and evaluated for antiviral activities against tobacco mosaic virus (TMV). The preliminary biological results indicated that most compounds exhibit excellent antiviral activity against TMV in vivo. Among these compounds, compounds 9c , 9i , and 9p displayed the similar curative effect against TMV (EC₅₀ = 287.05–322.47 µg/mL) to that of the commercial agent Ningnanmycin (EC₅₀ = 301.83 µg/mL). In particular, compound 9d demonstrated the best curative effect against TMV (EC₅₀ = 266.21 µg/mL), which was better than that of commercial Ningnanmycin.     

Synthesis and Antibacterial Activity of Novel Substituted Purine Derivatives

A series of novel N‐substituted‐2‐(6‐morpholino‐9H‐purin‐9‐yl)acetamide and 4‐(9‐((5‐substituted‐1,3,4‐oxadiazole/thiadiazole‐2‐yl)methyl)‐9H‐purin‐6‐yl)‐morpholine derivatives were synthesized and evaluated their antibacterial activities against rice bacterial leaf blight and tobacco bacterial wilt caused by Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (R. solanacearum) via the turbidimeter test in vitro. Antibacterial bioassay indicated that most compounds demonstrated good inhibitory effect against Xoo and R. solanacearum. Especially, compound 6a demonstrated the best inhibitory effect against Xoo with half‐maximal effective concentration (EC₅₀) value of 8.39 μg/mL, which was even better than those of commercial agents Bismerthiazol and Thiodiazole copper. The synthesized purine derivatives containing amide and 1,3,4‐oxadiazole/thiadiazole moieties exhibited excellent antibacterial activities against Xanthomonas oryzae pv. oryzae and R. solanacearum in vitro.     

Accelerating Oxygen‐Reduction Catalysts through Preventing Poisoning with Non‐Reactive Species by Using Hydrophobic Ionic Liquids

Developing cost‐effective electrocatalysts for the oxygen reduction reaction (ORR) is a prerequisite for broad market penetration of low‐temperature fuel cells. A major barrier stems from the poisoning of surface sites by nonreactive oxygenated species and the sluggish ORR kinetics on the Pt catalysts. Herein we report a facile approach to accelerating ORR kinetics by using a hydrophobic ionic liquid (IL), which protects Pt sites from surface oxidation, making the IL‐modified Pt intrinsically more active than its unmodified counterpart. The mass activity of the catalyst is increased by three times to 1.01 A mg^?1_Pt@0.9 V, representing a new record for pure Pt catalysts. The enhanced performance of the IL‐modified catalyst can be stabilized after 30 000 cycles. We anticipate these results will form the basis for an unprecedented perspective in the development of high‐performing electrocatalysts for fuel‐cell applications.     

预处理条件对Zn/Al-CLM的丙烷芳构化性能的影响

在脉冲微反装置上考察了不同的预处理条件对Zn/Al-CLM催化剂的丙烷芳构化反应的影响。结果表明，丙烷在Zn/Al-CLM催化剂上具有一定的的反应活性和芳烃选择性，而且芳构化主要转化为苯；载体Al-CLM的焙烧温度、金属锌负载量、活化温度等对Zn/Al-CLM催化剂的丙烷芳构化性能具有重要影响。载体经500℃预焙烧制备的Zn/Al-CLM催化剂具有最好的柱结构保留度，从而表现出最佳的芳构化性能；随着锌含量的增加，Zn/Al-CLM催化剂的酸量增大，从而使丙烷转化率增大，而选择性则是锌含量质量分数为5．8％时具有极大值；400℃活化处理可使Zn与Al-CLM之间具有适中的相互作用，从而使得Zn/Al-CLM具有较高的芳烃收率。     

利用太赫兹时域光谱鉴别爆炸物2,4-DNT和 2,6-DNT

利用太赫兹时域光谱测得了2,4-DNT和 2,6-DNT在0.3-2.0THz频谱范围的吸收谱和折射谱。借助高斯03程序对2,6-DNT进行结构优化和频率计算。2,6-DNT在1.09, 1.36 and 1.55 THz有三个明显吸收并被归因于分子间的相互作用。本文使用太赫兹光谱法对2,4-DNT和 2,6-DNT混合物做了定量分析。分析的结果与实际值基本一致,相对误差约为8%。     

Thermosensitive acetylated carboxymethyl chitosan gel depot systems sustained release caffeic acid phenethyl ester for periodontitis treatment

Periodontitis is a chronic inflammatory disease of tooth support tissues leading to progressive destruction of periodontal soft tissues as well as alveolar bone, and can be treated with anti-inflammatory and bone-protective agents to prevent disease progression. Caffeic acid phenethyl ester (CAPE) is a natural polyphenolic compound with anti-inflammation, anti-oxidation and bone tissue repair efficacy. In this work, we synthesized a thermosensitive hydrogel matrix of acetylated carboxymethyl chitosan (A-CC), and firstly applied for periodontal local drug delivery. The biocompatible CAPE-loaded A-CC hydrogel (CAPE-A-CC) has the advantages of forming a drug depot in situ, sustained release and precisely improving the drug concentration in the lesion sites compared with traditional systemic administration. In addition, CAPE-A-CC could significantly inhibit the expression of inflammatory cytokines of TNF-α, IL-1β, IL-6, and IL-17 in macrophages, and increased the expression of alkaline phosphatase (ALP) in human periodontal ligament stem cells (hPDLSC) related to osteogenesis. This study develops a novel in situ thermosensitive hydrogel delivery system to improve the therapeutic potential of natural active ingredient for periodontitis therapy.     

三元硼氮环的电子结构与成键

用从头算ＳＣＦ－ ＭＯ法对三元硼氮环２ 个系列８ 个分子的电子结构进行了研究．根据计算结果,由原子的轨道布居以及σ和π电子的分布,讨论了硼原子与氮原子间的成键情况．结果表明,硼原子和氮原子上加Ｈ 有利于环的稳定,同时削弱了Ｂ—Ｎ 键而增强了Ｂ—Ｂ键和Ｎ—Ｎ 键,对Ｂ２Ｎ 系列和ＢＮ２ 系列中的Ｂ原子和Ｎ 原子的净电荷的影响恰好相反．     

载溴树脂溴化酚类的研究

用简便方法制备得载溴树脂并用于酚类的溴化,当采用不同摩尔比的载溴树脂时,有选择地得到一溴、二溴及三溴代物,并有较高的产率,同时该树脂具有良好的稳定性。     

High-performance low-cost organic field-effect transistors with chemically modified bottom electrodes

The characteristics of organic field-effect transistors (OFETs) were dramatically improved by chemically modifying the surface of the bottom-contact Ag or Cu source-drain (D-S) electrodes with a simple solution method. The contact resistance and energetic mismatch typically observed with Ag D-S electrodes in pentacene bottom-contact OFETs can be properly eliminated when modified by the Ag-TCNQ (TCNQ = 7,7,8,8-tetracyanoquinodimethane). The pentacene transistors with low-cost Ag-TCNQ-modified Ag bottom-contact electrodes exhibit outstanding electrical properties, which are comparable with that of the Au top-contact devices. It thus provides a novel way toward high-performance low-cost bottom-contact OFETs.     

Preparation of 2,6-diisopropylnaphthalene with recycled process of isomers

2,6-Diisopropylnaphthalene（2,6-DIPN）,as the precursor of important monomer 2,6-naphthalene dicarboxylic acid,was prepared by hydroisopropylation of refined naphthalene with propene over shape-selective catalyst.Naphthalene conversion of 92% and 2,6-DIPN selectivity of 64% were obtained.Static melt crystallization was applied to separate and purify 2,6-DIPN from its isomers,resulted in a product purity of≥99%.The other isomers were converted into monoisopropylnaphthalene,which also reacted with propene to form 2,6-DIPN.A recycled process including hydroisopropylation,separation and transalkylation was established,the yield of 2,6-DIPN based on naphthalene could be doubled by one cycle operation.