Synthesis and Antibacterial Activity of Novel 5,5′-(Pyridine-2,6-Diyl)bis(4-Arylideneamino-3-Mercapto-1,2,4-Triazole)-Related Derivatives

The reaction of 5,5′-(pyridine-2,6-diyl)bis(4-amino-3-mercapto-1,2,4-triazole) with various aromatic aldehydes in acetic acid yielded the corresponding 5,5′-(pyridine-2,6-diyl)bis(4-arylideneamino-3-mercapto-1,2,4-triazole) derivatives. The structures of the synthesized compounds as well as their intermediates were confirmed by elemental analysis, infrared spectra, ¹H NMR spectra and mass spectra studies. All the synthesized title compounds were screened for their antibacterial activities, and the preliminary results revealed that some of them showed good activities against Escherichia coli and Pseudomonas aeruginosa.     

Enhanced Expression of GCRV VP6 in CIK Cells by Relative Sequence Optimization

Efficient expression of target protein is one of strategies for gene therapy or vaccine design. Many studies showed that codon optimization could enhance the expression of target proteins. In this paper, a target sequence of about 1.26 kb encoding the major capsid protein VP6 of grass carp reovirus (GCRV) and an optimized counterpart were synthesized and inserted into vectors for expressing VP6. The final constructs (named as pcDV6G and pcDV6YG) were transfected in Ctenopharyngodon idellus kidney (CIK) cells. The fluorescence analysis and the Western blot results showed that the gene fragment was transfected and expressed in CIK cells successfully. Although the qRT-PCR results showed no difference at the messenger RNA (mRNA) levels between the different versions of vp6 in the indicated stages, the enzyme-linked immunosorbent assay (ELISA) results showed that the protein level of VP6 expressed by pcDV6YG was higher than that by pcDV6G in the indicated hours. Taken together, these results suggest that the enhanced expression of GCRV VP6 in CIK cells by relative sequence optimization may be a good choice for making DNA vaccine against GCRV.     

pH-responsive pseudorotaxane between comblike PEO-grafted triblock polymer and α-cyclodextrin

The pH-responsive inclusion complexation of comblike triblock polymer, P2VP-b-PPEOMA-b-P2VP, with α-cyclodextrin (α-CD) was studied. The triblock polymer was prepared by reversible addition–fragmentation chain transfer polymerization (RAFT) and formed inclusion complexes (ICs) after selective threading of the PEO segment of the triblock polymer through the cavities of α-CD units. For comparison, PPEOMA homopolymer was prepared, and the inclusion complexation with α-CD was also studied. The formed ICs were characterized by XRD and ¹H NMR. The results revealed that P2VP-b-PPEOMA-b-P2VP can form ICs with α-CD even when forming micelles, and the introduction of P2VP had a great influence on the solution property and the stoichiometry of EO to CD of the inclusion complexes depending on the concentration and the pH of the solution.     

表面增强拉曼光谱在食品安全分析中的应用

拉曼光谱技术具有样品用量少、快速高效、无损分析等特点,表面增强拉曼光谱克服了常规拉曼光谱灵敏度低的缺点,可以获得更多物质结构信息,在现场快速筛查、检测和鉴别农兽残、限用或禁用添加剂分析检测中具有广阔的应用前景。本文综述了表面增强拉曼光谱在食品中农药残留、兽药残留和限/禁用添加剂检测中的研究进展,并展望了其发展前景。     

关于一元酸准确滴定判据的商榷

化学分析教科书中给出的弱酸能被准确滴定的条件是cKa≥1.0×10-8。本文根据这一判据的来源(滴定突跃≥0.3pH单位),对一元酸体系的滴定情况进行了严格数学处理。计算结果表明,只有同时满足弱酸的浓度c1.0×10-3mol/L和cKa≥1.0×10-8条件下,弱酸才能被准确滴定。对于浓度极稀的酸溶液(c≤1.4×10-4mol/L),无论强酸还是弱酸都不能被准确滴定。对教材很少涉及的不同浓度酸碱互相滴定的情况也给出了有价值的结论。     

Nitrobenzene degradation by micro-sized iron and electron efficiency evaluation

The effect of pH, temperature, zero-valent iron (ZVI) dosage and reaction duration on nitrobenzene (NB) degradation by micro-sized ZVI was investigated in batch experiments and the electron efficiency (EE) was evaluated at constant pH. The experimental results showed that the reaction rate constant attained 0.616 min^?1, which was far higher than reported in previous studies. The decrease in pH and increase in temperature of the reaction bath promoted the reaction kinetics. ZVI dosage and reaction duration were two key factors affecting NB reduction and EE. A lower ZVI dosage and a slightly longer reaction duration could afford an optimised EE and optimum NB removal. A prolonged reaction or too high a ZVI dosage resulted in increased ZVI waste.     

石墨烯纳米孔的制备及λ-DNA穿孔初步研究

纳米孔测序是有可能实现"$1,000 Genome"目标的技术之一.近年来,研究较多的纳米孔有蛋白质纳米孔和硅基材料的固态纳米孔.蛋白孔寿命比较短,而基于硅基底的固态纳米孔深度显著超过单链DNA相邻碱基的间距,所以,无法实现DNA的单个碱基的分辨.作者用聚焦离子束先制造氮化硅基底,并在该基底上铺设石墨烯,再用聚焦电子束刻蚀石墨烯,获得直径10 nm以下的纳米孔,初步分析了DNA穿越纳米孔时产生的电信号及穿孔噪音,向单层石墨烯纳米孔测序DNA迈出了一步.     

One-pot synthesis–assembly–separation of cucurbit[6]uril via SO3H-functionalized ionic liquids

A novel microwave-assisted route to synthesize cucurbit[n]uril in SO₃H-functionalized ionic liquids was reported, which enabled the automatic separation of cucurbit[6]uril through anion assembly. For the first time, the route has realized synthesis–assembly–separation of cucurbit[6]uril in one pot. The reaction yield and separation efficiency can be tuned by choice of anionic groups in ionic liquids.     

免疫胶体金技术的应用与展望

免疫胶体金技术是一种新型固相标记免疫检测技术,因其独特的性质在许多领域得到广泛应用和快速发展。简述了免疫胶体金技术在电镜、光镜快速检测诊断中的发展以及在生物医学、免疫组织化学和细胞生物学等领域的研究和应用。未来免疫胶体金技术在提高胶体金制备质量的同时将实现定量和多元化检测。     

Sequence-Dependent DNA Functionalization of Upconversion Nanoparticles and Their Programmable Assemblies

DNA-modified lanthanide-doped upconversion nanoparticles (DNA-UCNPs) that combine the functions of DNA and the optical features of UCNPs have shown great promise in a wide range of fields. However, challenges remain in precisely tethering and orienting the DNA strands on the UCNP surface. Herein, we systematically investigate the sequence dependence of DNAs in their interactions with UCNPs, and reveal that poly-cytosine (poly-C) has high affinity for the UCNP surface. A general approach to synthesize monodispersed DNA-UCNP conjugates is developed using poly-C-containing diblock DNA strands. The poly-C segment of the DNA strand binds to the surfaces of UCNPs and the second segment is oriented perpendicularly on the UCNP surface, making the DNA-UCNPs highly stable and monodispersed in aqueous solution. The dense layer of DNA on the UCNP surface enables the programmable assembly of UCNPs with other DNA-functionalized nanoparticles or DNA origamis through hybridization, resulting in the formation of well-organized complex structures.