Optical waveguides at micro/nanoscale based on functional small organic molecules

Optical waveguides synthesized at the micro/nanoscale have drawn great interest for their potential applications in high speed miniaturized photonic integrations. In this Perspective article, we mainly focus on the related works on active optical waveguides based on functional small organic molecules in micro/nano regime. We begin with a general overview of recent progress in sub-wavelength optical waveguides, including the development of waveguide materials of inorganic semiconductors, polymers, and small organic molecules. Then brief highlights are put on the recently reported organic optical waveguides with various unique optical properties induced by the ordered molecular aggregations in the micro/nano-sized solid-state structures, such as polarized emission, lasing, aggregation-induced enhanced emission, etc. This article concludes with a summary and our personal view about the direction of future development in organic opto-functional waveguides as photonic devices.     

Synthesis and biological evaluation of novel acenaphthene derivatives as potential antitumor agents

Twelve novel acenaphthene derivatives have been synthesized. The structures of all compounds were confirmed by 1H-NMR, MS and elemental analysis. Their antitumor activities were evaluated in six human solid tumor cell lines, namely non-small cell lung cancer (H460), human colon adenocarcinoma (SW480), human breast cancer cell (MDA-MB-468 and SKRB-3), human melanoma cell (A375) and human pancreatic cancer (BxPC-3). Among them, compound 3c shows the best antitumor activity against SKRB-3 cell line, as high as the positive control adriamycin.     

Differential pulse anodic stripping voltammetric determination of Cd and Pb at a bismuth glassy carbon electrode modified with Nafion, poly(2,5-dimercapto-1,3,4-thiadiazole) and multiwalled carbon nanotubes

A simple, cheap, and nonpolluting method was developed for the cloud point extraction of gold (Au) and palladium (Pd). It is based on the complexation reaction of Au and Pd with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) and micelle mediated extraction of the complex using the non-ionic surfactant poly(ethylene glycol) mono-p-nonylphenyl ether (PONPE 7.5). Under the optimized experimental conditions, the enrichment factors are 16 and 17 for Au and Pd, respectively, for 15?mL of preconcentrated solution. The limits of detection are 3.8???g?L^?1 and 1.8???g?L^?1 for Au and Pd, respectively. The relative standard deviations are 1.4% for Au and 0.6% for Pd (n?=?11). The method was successfully applied to the determination of Au and Pd in certified reference materials and mine samples.

Substance P conjugated to CdTe quantum dots triggers cytosolic calcium concentration oscillations and induces quantum dots internalization in the pancreatic carcinoma cell line AR4-2J

Highly fluorescent CdTe quantum dots (QDs) stabilized by 3-mercaptopropionic acid were prepared by an aqueous solution approach and used as a fluorescent label to link substance P (SP) in studying the interaction of SP with NK-1 receptor, which was expressed on the AR4-2J cell line. Nonspecific adsorptions of CdTe QDs on the AR4-2J cell membrane were observed, whereas the QD-SP conjugates successfully crossed the cell membrane and entered the cytosol. SP is a neurotransmitter, and neurotransmitter-induced calcium concentration oscillation is a common phenomenon in diverse cells especially of secretory type. Cytosolic calcium concentration responses were studied in the AR4-2J cell line during stimulation with SP and QD-SP conjugates. The oscillations triggered by SP and QD-SP conjugates were dose-dependent and very similar. Such QD-SP conjugates readily internalized into the cytosol as would be expected of an active NK-1 ligand. Therefore QD-SP conjugates could be used successfully to study ligand and NK-1 receptor interactions in live cells. Our research may provide a meaningful reference for congener research.     

Surface characterization of 7S and 11S globulin powders from soy protein examined by X-ray photoelectron spectroscopy and scanning electron microscopy

In this study the surface composition of 7S and 11S globulin powders from soybean proteins by aqueous buffer and reverse micelle extractions had been examined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Analysis by XPS revealed that the O and N atomic percentage of 7S and 11S globulin surfaces from bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelle was higher than from aqueous buffer, but the C atomic percentage was lower. The O/C ratio of the 7S globulin powder from aqueous buffer and reverse micelle was similar while significant differences were obtained in the O/C ratio of the 11S globulin powder, N/C atom ratios of the 7S and 11S globulin powders and high-resolution XPS C 1s, N 1s, O 1s spectra. Powder microstructure after reverse micelle treatment showed the presence of small pores, indicating the effect of reverse micelle on the 7S and 11S globulin structure. The obtained results indicated that the reverse micelle could affect the C, O and N components on the surface of soybean proteins.     

High-light induced superoxide radical formation in cytochrome b₆f complex from Bryopsis corticulans as detected by EPR spectroscopy

The generation of superoxide radical (O?·?) in Cyt b?f of Bryopsis corticulans under high light illumination was studied using electron paramagnetic resonance (EPR) spectroscopy. This could be evidenced by the addition of SOD which specifically reacted with O?·?. The generation of O?·? was lost in the absence of oxygen and was found to be suppressed in the presence of NaN? and be scavenged by extraneous antioxidants such as ascorbate, β-carotene and glutathione which could also scavenged 1O?*. These results indicated that O?·? which produced under high light illumination in Cyt b?f of B. corticulans might rise from a reaction which 1O?* could participated in. Also the photo-protection mechanism to Cyt b?f complex by antioxidants which might contain in thylakoid was speculated.     

The synthesis and application of 1-(o-nitrophenyl)-3-(2-thiazolyl)triazene for the determination of palladium(II) by the resonance enhanced Rayleigh light-scattering technique

The resonance Rayleigh light-scattering (RRLS) signal of a new triazene reagent; 1-(o-nitrophenyl)-3-(2-thiazolyl)triazene (o-NPTT), was firstly synthesized and characterized in this paper at 500-600 nm wavelength range and can be enhanced remarkably by Pd2+. According to this phenomenon, a new method was developed for the determination of Pd2+ by the RRLS technique in the presence of Tween-80. The calibration graph showed good linearity over a concentration range of 5.0-700 microg l(-1) with a detection limit of 1.0 microg l(-1). There are almost no foreign ions interfered in the determination at a more than fivefold concentration of Pd2+. The method is relatively sensitive, of good selectivity and has been successfully used for the determination of trace palladium in the slag of fertilizer factories and catalyst samples.     

测定麦芽糖转糖苷反应体系组成的高效液相色谱法

建立了分析低聚异麦芽糖组成的高效液相色谱法，采用Spherisorb-NH2色谱柱，示差折光检测器，乙腈－水（体积比70：30）为流动相，外标法定量测定；结果显示各糖质量浓度在0．1－10g/L范围内与峰面积呈良好线性关系，相关系数为0．999 0－0．999 7；应用法跟踪了pH5．0的柠檬酸－柠檬酸钠缓冲溶液中以α－葡萄糖转苷酶为催化剂在58℃温度下的麦芽糖转糖苷反应，分析了反应体系组成随时间的变化，得到了上述反应条件下麦芽糖最大限度地转化为低聚异麦芽糖的最佳反应时间为24h；该法快捷、简单、准确，可用于低聚异麦芽糖生产的质量控制。     

固相微萃取/GC直接测定废水中的三种氯酚

研究了运用固相微萃取／GC直接测定水中的三种氯酚的方法，得到了分析三种氯酚的SPMF最佳萃取条件。选取聚丙烯酸酯（PA）萃取头，水溶液调pH=2,并用NaCl饱和，室温下在持续磁力搅拌下直接萃取40min，纤维萃取头在260℃脱附5min。所建立的方法适于快速、方便地测定水中三相氯酚，无须浓缩和预处理。     

纳米尖晶石LixMn2O4的制备与电化学性能表征

Nano-spinel Li_xMn₂O₄(0.6 ≤x≤ 1.0) was synthesized by two steps of coprecipitation and calcination. The influences of calcination temperature, time and Li/Mn ratio on the crystal structure and the particle size of Li_xMn₂O₄ were investigated. It was shown that the higher the calcination temperature, the more complete the crystal structure, and the larger the particle size. Moreover, the influence of calcination time on the crystal structure was insignificant when it was more than 3h at 700℃. With the increase of x in Li_xMn₂O₄ in the range of 0.6～1.0, the d111 and lattice parameter a increased first and then decreased. The electrochemical properties of nano-spinel LiMn₂O₄ using as cathode material of lithium-ion battery were studied. The low discharge capacity might be due to the irreversible capacity loss brought by the large surface area and lattice vacancies of the nano-spinel.