三维还原氧化石墨烯/β-环糊精复合物的合成及其电化学检测水中左氧氟沙星北大核心CSCD

成功构筑了β-环糊精修饰的三维还原氧化石墨烯复合材料(3D-rGO/β-CD),并对该复合材料进行扫描电子显微镜、傅里叶红外光谱、热重分析和拉曼光谱分析等一系列的表征,分析了其形貌和结构的特征。进一步将其修饰到玻碳电极(GCE)表面,构建了一种新型电化学传感器(3D-rGO/β-CD/GCE)。利用3D-rGO/β-CD/GCE电化学传感器,通过微分脉冲伏安法(DPV)对左氧氟沙星(LEV)进行了检测。其中,具有多孔结构的三维还原氧化石墨烯具有优异的导电性能、比表面积大、化学稳定性好等优良的性质,而修饰的β-环糊精能在其环形腔内与客体分子结合形成超分子包合物,进而可以对LEV进行有效识别。研究结果显示,在最优实验条件下,3D-rGO/β-CD/GCE对左氧氟沙星的检测具有较宽的线性范围(1~150μmol/L),且检测限可达0.33μmol/L,同时该修饰电极还表现出良好的选择性和稳定性。此外,成功将其应用于实际水样中LEV的检测,表明该传感器具有一定的应用潜力。     

单原子分散的Ir-N-C燃料电池阳极抗中毒催化剂

燃料电池的阳极抗中毒研究是重要课题,探索具有超高质量活性和抗CO毒化的阳极催化剂具有显著的科学意义和应用价值。本文成功制备了Ir原子级别分散在N掺杂碳的载体上的新催化剂,并且发现该Ir-N-C对甲酸具有良好的电催化氧化性能,其质量比活性为商业Pd/C的48倍。组装了燃料电池单电池进行测试,结果显示,Ir-N-C催化剂在单电池中的质量比功率密度高达281 mW/mg,较商业Pd/C催化剂提升了3倍。同时,Ir-N-C对CO毒化的耐受性大大增强,经过14000 s的长期测试后,其活性仅衰减68%,优于商业Pd/C催化剂（衰减85%）。并且,该催化剂能够简单有效的大批量制备,为单原子催化剂的大批量制备提供了新思路。     

N-Doped Carbon Nanofibers Encapsulating CoO@Co9S8 Nanoparticles: Preparation from S-Rich Co32 Coordination Cluster Precursors by Electrospinning and Application for Superior Li-ion Storage

Thiacalixarene-supported Co₃₂nanoclusters encapsulated in polyacrylonitrile nanofibers(Co₃₂@PAN-NFs) by electrospinning have been utilized as precursors to fabricate N-doped CoO@Co₉S₈ carbon nanofibers(CoO@Co₉S₈@CNFs) for superior Li-ion storage. The S-rich Co₃₂ clusters capped by organic sheets afforded the well dispersed cobalt oxide/sulfide nanoparticles embedded in carbon nanofiber composites by direct calcination. The N-doped CoO@Co₉S₈@CNFs nanocomposites have been utilized as anode materials for lithium ion battery with the reversible capabilities being of 1051.8, 967.6, 894.7, 782.7, 669.5 and 525.4 mA·h/g at 0.1, 0.2, 0.5, 1, 2 and 3 A/g, respectively. The CoO@Co₉S₈@CNFs also showed a relatively high stable capacity of 551.7 mA·h/g at the current density of 1 A/g after 200 cycles of rate experiments. The as-obtained N-doped CoO@Co₉S₈@CNFs nanocomposites exhibited superior reversible capacity, rate performance, Coulomb efficiency(74.5% vs. 63.9%) and cyclic stability comparing with the CoO@Co₉S₈@C derived from simple annealing of Co₃₂ templates.     

Sigma-1 Receptor Agonist TS-157 Improves Motor Functional Recovery by Promoting Neurite Outgrowth and pERK in Rats with Focal Cerebral Ischemia

Sigma-1 (σ-1) receptor agonists are considered as potential treatment for stroke. TS-157 is an alkoxyisoxazole-based σ-1 receptor agonist previously discovered in our group. The present study describes TS-157 profile in a battery of tests for cerebral ischemia. Initial evaluation demonstrated the compound’s safety profile and blood–brain barrier permeability, as well as its ability to induce neurite outgrowth in vitro. The neurite outgrowth was shown to be mediated via σ-1 receptor agonism and involves upregulation of ERK phosphorylation (pERK). In particular, TS-157 also significantly accelerated the recovery of motor function in rats with transient middle cerebral artery occlusion (tMCAO). Overall, the results herein support the notion that σ-1 receptor agonists are potential therapeutics for stroke and further animal efficacy studies are warranted.     

利用高吸水树脂优化3个中学化学实验*

尝试利用高吸水树脂对“酸碱中和反应、碳酸钠和碳酸氢钠分别与稀盐酸反应、探究分子运动现象”这3个实验进行创新改进,充分利用了高吸水树脂特殊的结构作用,使3个实验的现象更加显著。改进实验操作简便,高效简洁,值得推广到一线化学课堂的演示实验或学生分组实验。     

Laser-induced breakdown spectroscopy in Asia

Laser-induced breakdown spectroscopy (LIBS) is an analytical detection technique based on atomic emission spectroscopy to measure the elemental composition. LIBS has been extensively studied and developed due to the non-contact, fast response, high sensitivity, real-time and multi-elemental detection features. The development and applications of LIBS technique in Asia are summarized and discussed in this review paper. The researchers in Asia work on different aspects of the LIBS study in fundamentals, data processing and modeling, applications and instrumentations. According to the current research status, the challenges, opportunities and further development of LIBS technique in Asia are also evaluated to promote LIBS research and its applications.     

Design,synthesis, and insecticidal activities of novel diamide derivatives with alpha-amino acid subunits

A series of diamide derivatives containing α-amino acids were designed and synthesized. These compounds were evaluated for their insecticidal activities against Plutella xylostella, Mythimna separate, Myzus persicae, and Tetranychus cinnabarinus. Most of the title compounds containing an l -phenylglycine skeleton were endowed with good activities at the concentration of 500 mg·L⁻¹. Compounds ( R)-A6 showed a potential value for further optimization as an insecticidal lead with the LC₅₀ value of 86.8 mg·L⁻¹.     

ω-芋螺毒素的定量构效关系与虚拟筛选

ω-芋螺毒素属于海洋生物活性多肽,由24-31个氨基酸残基组成.特异性作用于电压敏感的钙离子通道(VGCCs),能够直接开发成药物或作为先导化合物进行新药开发.本文应用新型氨基酸残基结构描述符cscales和遗传偏最小二乘算法,对ω-芋螺毒素进行定量构效关系(QSAR)研究,并设计、构建了容量为2244个化合物的N-型和P/Q-型VGCC拮抗剂虚拟组合多肽库,然后分别采用QSAR模型预测和相似性搜索方法对组合多肽库进行了虚拟筛选.研究结果表明,建立的N-型和P/Q-型VGCC拮抗剂QSAR模型均具有较好的预测能力,交叉验证相关系数(CV-r2)均大于0.89.主成分分析和聚类分析结果表明,虚拟组合多肽库中化合物具有较好的结构多样性和差异性.通过虚拟筛选,得到了具有高预测活性的6个N-型和19个P/Q-型钙离子通道拮抗剂,为进一步的合成和活性评价奠定了理论基础.同时,本文建立的多肽QSAR预测模型和虚拟筛选策略,为其它多肽类化合物的定量构效关系研究和虚拟筛选提供了参考.     

基于正电荷和光热协同效应的新型半导体聚合物纳米抗菌材料

由于抗生素的不当使用和细菌多药耐药的出现, 迫切需要开发新的抗菌剂. 本文制备了具有光热转换性能的正电荷半导体高分子材料及具有协同抗菌活性的半导体聚合物纳米粒子(SP-PPh₃ NPs). SP-PPh₃ NPs的光热转化效率为43.8%. 带正电荷的SP-PPh₃ NPs可以附着在细菌上, 有助于将热量有效传递给细菌. 在热和正电荷的协同作用下, SP-PPh₃ NPs对革兰氏阴性大肠杆菌(E. coli)和革兰氏阳性金黄色葡萄球菌(S. aureus)均具有抗菌活性, 其对二者的体外抑菌率分别为99.9%和98.6%. 此外, SP-PPh₃ NPs具有良好的生物相容性, 对小鼠的主要器官几乎无副作用. 对细菌感染的小鼠皮肤伤口用SP-PPh₃ NPs治疗12 d后, 伤口可以很好地愈合.