Synthesis and electronic absorption and fluorescence of 2-arylbenzothiazole derivatives

A series of new 2-arylbenzothiazoles have been prepared in high yields by Jacobson's cyclization condensation of 2-aminobenzenethiol with benzoyl chloride or benzaldehyde derivatives under three different routes. These compounds have been fully characterized by EA, IR, NMR and MS. The electronic absorption and fluorescence of these compounds have been systematically investigated for the first time. The relationships between their photophysical properties and structures have been discussed. The alteration of absorption and emission wavelengths can be elucidated by Hammett's substituent constants.     

Improved Carotenoid Productivity and COD Removal Efficiency by Co-culture of Rhodotorula glutinis and Chlorella vulgaris Using Starch Wastewaters as Raw Material

Utilization of low-cost raw materials for the bio-based chemical production, such as carotenoids, by the co-culture of Rhodotorula glutinis and Chlorella vulgaris has recently become an attractive option. In this study, the primary nutrients of starch wastewater were analyzed, which were used for carotenoid production by the co-culture strategy in a 5-L fermenter around 4000 Lux light intensity. Synergistic effect of gas utilization revealed that the two species could build up the beneficial balance on mutualism. The maximum carotenoid productivity and COD removal efficiency were 12.34 mg/L and 79.6%, respectively, which were higher than those of monoculture yeast (8.31 mg/L and 54.1%). The organic acids, amino acids, and sugar removal efficiencies were increased by 85%, 31%, and 44%, respectively, and more than three kinds of carotenoids were identified compared with those of monoculture yeast. The results demonstrated that the co-culture strategy of two different nutritional microorganisms could significantly improve carotenoid productivity and COD removal efficiency.

     

Fabrication of hyaluronic acid-based nanoparticles and studies on their radical scavenging activity

The purpose of this paper is to study the stability, radical scavenging activities, and bio-safety of cysteine-conjugated hyaluronic acid nanoparticles (Cys-conj-HA NPs). Additionally, the feasibility of utilizing these NPs as drug delivery systems is discussed. The structures of synthesized Cys-conj-HA polymers were analyzed using ¹H nuclear magnetic spectrum (¹H NMR) and Fourier transform infrared spectroscopy (FTIR) spectra. The stability, radical scavenging activity, and bio-safety of fabricated Cys-conj-HA NPs were investigated. Transmission electron microscopy (TEM) photograph illustrated that Cys-conj-HA NPs possessed spherical shapes with an average diameter of approximately 230 nm. Furthermore, these NPs exhibited high stability at temperatures of 4, 25, and 37°C. Notably, Cys-conj-HA NPs demonstrated significant free radical scavenging capabilities. The high cell viability observed indicated the absence of cytotoxicity from Cys-conj-HA NPs. Additionally, bio-safety studies revealed that these NPs did not induce acute toxicity in the blood and viscera of cargo-free NPs treated mice. Elisa assays indicated that there was no significant difference in the concentrations of interferon-γ (INF-γ) and tumor necrosis factor-α (TNF-α) between Cys-conj-HA NPs and normal saline (NS) treated mice (ns, p > 0.05), suggesting the absence of an inflammatory reaction caused by these NPs. Consequently, it can be concluded that Cys-conj-HA NPs are sufficiently safe to be employed as a vehicle for delivering oxidizing drugs.     

Nonlinear optical chromophores with pyrrole moieties as the conjugated bridge: enhanced NLO effects and interesting optical behavior

A series of nonlinear optical (NLO) chromophores were successfully prepared, in which pyrrole moieties were the conjugated bridge. In comparison with their analogues containing furan or thiophene groups as the bridge, these chromophores demonstrated similar or enhanced NLO effects (up to 3.3 times) and interesting optical behavior. While the acceptor groups were malononitrile (Mal), 3-phenyl-5-isoxazolone (Iso), and 1,3-diethylthiobarbituric acid (Bar), the chromophores exhibited much blue-shifted maximum absorption wavelengths (lambda max) (up to 36 nm); however, the lambda max of the chromophore containing tricyanovinyldihydrofuran (TCF) as acceptor became much longer than that of the analogue (up to 75 nm).     

One-pot synthesis and photoluminescence properties of core/porous-shell olive-like BaWO4 microstructure by a template-assisted hydrothermal method

Core/porous-shell olive-like crystalline BaWO₄ is synthesized by a combined simple hydrothermal method and soft template approach. The prepared product shows an olive-like shape with diameter of ～2 μm, length of ～4 μm, and the thickness of the shell of about 65 nm, which are orderly assembled by many nanoparticles. A possible formation mechanism of olive-like BaWO₄ microstructure involving interfacial recognization of ions, nucleation, aggregation, in situ growth and Ostwald ripening process is proposed. Polyacrylic acid sodium (PAAS) as a template plays an important role in inducing the nucleation and growth of olive-like BaWO₄ microcrystalline. Other shapes of BaWO₄ microcrystalline are also fabricated by varying the concentration of PAAS and Ba²⁺. The olive-like product with a core-shell structure which exists a large number of pores on crystal surface shows excellent photoluminescence property, which have potentially applied prospects in fields such as light display systems etc.     

分散固相萃取-在线凝胶色谱-气相色谱-质谱联用法快速检测紫菜中的农药多残留

建立了紫菜中农药多残留的在线凝胶色谱-气相色谱-质谱联用（GPC-GC/MS）检测方法。以有机氯、有机磷、三嗪类和菊酯类的19种农药为目标物,对比了丙酮、丙酮/二氯甲烷（1:1,v/v）和乙腈3种有机溶剂的提取效果,通过石墨化炭黑粉（GCB）和N-丙基乙二胺粉（PSA）分散固相萃取净化和GPC在线净化,气相色谱-质谱联用法分析,外标法定量。结果表明,此方法实现了在线净化与分析检测的自动化,缩短了分析时间。分析物在10~1000 μg/L范围内线性关系良好,相关系数r>0.995;采取GPC大体积进样和气相色谱进样口的程序升温方式提高了检测灵敏度,检出限为0.005~0.03 mg/kg。方法的平均添加回收率在70%~120%之间,相对标准偏差（RSD）均小于15%。该方法简单、快速、具有良好的回收率和重复性,适用于紫菜样品中农药多残留的快速灵敏检测。     

脂肪二胺桥联受阻酚清除DPPH.的活性及动力学研究

采用DPPH法对脂肪二胺桥联受阻酚的抗氧化活性和清除反应动力学进行了研究,结果表明,脂肪二胺桥联受阻酚具有良好清除DPPH.的活性,随脂肪二胺桥联受阻酚浓度的增大和清除反应时间的延长,清除活性先快速降低随后变化较小;随着桥联基的增长,清除活性降低。脂肪二胺桥联受阻酚清除DPPH.的反应为一级反应,且反应速率常数随着桥联基链的增长而降低。