光对荧光增白剂VBL的影响

探讨和阐明了二苯乙烯结构的增白剂VBL在含紫外线的光源照射下，会产生顺－反异构现象，并在一定程度上改变该产品的外观及降低其稀水溶液的吸光度，从而降低用它增白织物的白度，因此，在使用荧光增白HVBL地，其溶液应避光保存，科学合理使用。     

Estimation of the hydrophobicity modifications in meat proteins upon thermal treatment

A fluorescent probe method using 8-anilino-l-naphthalene sulfonic acid (ANS) and all-trans-retinol (RET) has been used to study the effects of heat treatments on the hydrophobicity of meat proteins. The number of ANS binding sites per unit protein increased from 0.75 for unheated samples to 2.12 for meat proteins heated at 100° C for 30 min. The number of RET binding sites increased from 0.13 to 0.46 with the same heat treatment. This is discussed in terms of % increase in aromatic (182.7%) and aliphatic (253.5%) hydrophobicity for meat proteins heated at 100° C for 30 min. On the other hand, the assay was able to discriminate between samples of meat proteins receiving heat treatments with 100° C intervals (between 40 and 100° C).     

含铁尘泥X荧光光谱分析方法的试验研究

通过高温灼烧对样品进行预处理,氧化游离碳、金属铁等还原性物质。采用熔融法制备样片,以x射线荧光光谱法测定含铁尘泥TFe,CaO,MgO,SiO2,Al2O3,P,TiO2,Mn,As,K2O,Pb,Zn等12种成份。使用铁矿石标准样品并加入经过化学法准确定值的生产样品,采用内标法,建立校准曲线。通过数学校正消除元素间的重叠和吸收—增强效应;采用最佳熔融条件和测定条件,建立含铁尘泥中12种元素的测量方法。采用本法测得各元素相对标准偏差在0．18％～6．52％之间。对于未知样品,采用本法测试的结果与采用传统化学湿法测试的结果相符。     

Vibration‐Induced Emission (VIE) of N,N′‐Disubstituted‐Dihydribenzo[a,c]phenazines: Fundamental Understanding and Emerging Applications

Organic fluorophores with dual‐emission and large Stokes shifts are attracting great attention due to their importance in fundamental research and technique applications. This Progress Report gives an account on how a novel luminescence mechanism termed vibration‐induced emission (VIE) is established. The VIE mechanism is coined for the rationalization of an alterable dual emission of V‐shaped N,N′‐disubstituded‐dihydribenzo[a,c]phenazines (DHPs), which are originated from a bent‐to‐planar vibration and the reverse in the excited state. The validation of the VIE mechanism is highlighted, such as the work reporting the utilization of chemically‐locked strategy to snapshot the excited‐state planarization of DHPs, and the application of the approach of steric hindrance‐induced planarization to tune the ground‐state geometry of DHPs. Moreover, the emerging applications of this VIE concept in photoelectric and biomedical disciplines are summarized. Additionally, further development of the VIE systems as well as the remaining challenges are prospected. This report could arouse wide interest from various fields to the specific area of VIE, which would not only broaden the VIE territory but also enlarge the scope of advanced functional materials.     

Amine‐derivatized poly(diallyldimethylammonium chloride) from N‐vinylformamide copolymerization

The reactivity ratios for the aqueous free‐radical copolymerization of diallyldimethylammonium chloride and N‐vinylformamide were found to be 0.13 and 1.92, respectively, from a Fineman–Ross analysis of a series of batch polymerizations. Because batch polymerization could not give a uniform product in a high yield with two monomers of such different reactivities, a semibatch procedure was developed in which the more reactive N‐vinylformamide was added in 10 steps over the course of the copolymerization. The poly(diallyldimethyl‐ ammonium chloride‐co‐N‐vinylformamide) copolymers were hydrolyzed to give poly(diallyldimethylammonium chloride‐co‐vinylamine). The utility of the vinylamine/diallyldimethylammonium chloride copolymers was demonstrated by the preparation and characterization of three derivatives: (1) a copolymer with coupled dansyl groups for fluorescence detection; (2) a copolymer with coupled dabsyl groups for ultraviolet–visible detection; and (3) an ultra‐high‐molecular‐weight (1.6 × 10⁶ Da) poly(diallyldimethylammonium chloride) by chain extension (coupling) with glycerol diglycidyl ether. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1068–1075, 2007     

CdTe nanoparticles display tropism to core histones and histone-rich cell organelles

The disclosure of the mechanisms of nanoparticle interaction with specific intracellular targets represents one of the key tasks in nanobiology. Unmodified luminescent semiconductor nanoparticles, or quantum dots (QDs), are capable of a strikingly rapid accumulation in the nuclei and nucleoli of living human cells, driven by processes of yet unknown nature. Here, it is hypothesized that such a strong tropism of QDs could be mediated by charge-related properties of the macromolecules presented in the nuclear compartments. As the complex microenvironment encountered by the QDs in the nuclei and nucleoli of live cells is primarily presented by proteins and other biopolymers, such as DNA and RNA, the model of human phagocytic cell line THP1, nuclear lysates, purified protein, and nucleic acid solutions is utilized to investigate the interactions of the QDs with these most abundant classes of intranuclear macromolecules. Using a combination of advanced technological approaches, including live cell confocal microscopy, fluorescent lifetime imaging (FLIM), spectroscopic methods, and zeta potential measurements, it is demonstrated that unmodified CdTe QDs preferentially bind to the positively charged core histone proteins as opposed to the DNA or RNA, resulting in a dramatic shift off the absorption band, and a red shift and decrease in the pholuminescence (PL) intensity of the QDs. FLIM imaging of the QDs demonstrates an increased formation of QD/protein aggregates in the presence of core histones, with a resulting significant reduction in the PL lifetime. FLIM technology for the first time reveals that the localization of negatively charged QDs to their ultimate nuclear and nucleolar destinations dramatically affects the QDs' photoluminescence lifetimes, and offers thereby a sensitive readout for physical interactions between QDs and their intracellular macromolecular targets. These findings strongly suggest that charge-mediated QD/histone interactions could provide the basis for QD nuclear localization downstream of intracellular transport mechanisms.     

Color control of natural fluorescent proteins by photonic crystals

The emission of fluorescent proteins inside photonic crystals is studied. It is demonstrated that the apparent emission color of the fluorescent protein can be controlled externally by the photonic crystal. With increasing crystal lattice parameter, the appearance of the proteins turns from orange to red, and suddenly to green. The dramatic color changes agree with the theoretically expected redistribution of light escaping around the stop band of the photonic crystal. Our experiments show the potential of combining biological systems with nanophotonics. This "biophotonic engineering" may be extended to control emission rates and complex F?rster energy-transfer systems obtained by protein engineering.     

Designing Squaraine Dyes with Bright Deep-Red Aggregation-Induced Emission for Specific and Ratiometric Fluorescent Detection of Hypochlorite

Development of ratiometric fluorescent hypochlorite probes with strong long wavelength fluorescence in aqueous medium, high resistance to photobleaching, high sensitivity and selectivity, and low biological toxicity remains a challenge. In this work, a molecular design strategy is proposed that can transform the traditional squaraine dyes (SQs) with aggregation-caused quenching character into aggregation-induced emission (AIE)-active luminogens by functionalizing the end-groups with tetraphenylethylene units and further introducing hydrophilic sulfonate group as the side chains. The resulting TPE-SQ5 not only emits strong deep-red fluorescence with a high quantum yield of 11.0% and high photostability, but more encouragingly can serve as a ratiometric fluorescent hypochlorite probe with high selectivity and sensitivity (detection limit: 5.6 nm ), which indeed is the first report for SQs. The detailed sensing mechanism study demonstrates that the oxindole product with sulfonate substitution is responsible for the ratiometric fluorescent response. Furthermore, TPE-SQ5 nanoparticles with high biocompatibility and low cytotoxicity are successfully used for ratiometrically imaging exogenous and endogenous hypochlorite in living cells.     

新型U(π)形紧凑型荧光灯管接桥机的研究

在U（π）形紧凑型荧光灯管自动、半自动接桥机上，用一种新型的四管夹头取代传统的两管夹头方式，缩短了工艺路径，提高了生产效率，并在一台设备上实现了2U、3U和4U等3种灯形的接桥。