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Tuning the color output of rare-earth ion doped luminescent nanomaterials has important scientific significance for further extending applications in color displays, laser sources, optoelectronic devices, and biolabeling. In previous studies, pre-designed phase modulation of the femtosecond laser field has been proven to be effective in tuning the luminescence of doped rare-earth ions. Owing to the complex light-matter interaction in the actual experiment, the dynamic range and optimal efficiency for color tuning cannot be determined with the pre-designed phase modulation. This article shares the development of an adaptive femtosecond pulse shaping method based on a genetic algorithm, and its use to manipulate the green and red luminescence tuning in an Er3+-doped glass ceramic under 800-nm femtosecond laser field excitation for the first time. Experimental results show that the intensity ratio of the green and red UC luminescence of the doped Er3+ ions can be either increased or decreased conveniently by the phase-shaped femtosecond laser field with an optimal feedback control. The physical control mechanisms for the color tuning are also explained in detail. This article demonstrates the potential applications of the adaptive femtosecond pulse shaping technique in controlling the color output of doped rare-earth ions. [ABSTRACT FROM AUTHOR]

There were many studies performed to assess the association between X-ray repair cross-complementing group 1 (XRCC1) Arg194Trp polymorphism and lung cancer risk in Chinese Han population, but contradictory results were reported. To provide a comprehensive and objective assessment of the association, a meta-analysis of all eligible case-control studies was carried out. After searching the databases and reading the abstracts, 12 case-control studies on the association between XRCC1 Arg194Trp polymorphism and lung cancer risk were finally included into this meta-analysis. Those 12 studies included a total of 4,385 cases and 4,545 controls. XRCC1 Arg194Trp polymorphism was associated with increased risk of lung cancer in Chinese Han population under three main models (allele contrast model, odds ratio (OR) = 1.12, 95 % confidence interval (CI) 1.00-1.26, P = 0.049; homozygote model, OR = 1.27, 95 % CI 1.09-1.48, P = 0.003; recessive model, OR = 1.26, 95 % CI 1.09-1.46, P = 0.003). However, there was no obvious association between XRCC1 Arg194Trp polymorphism and lung cancer risk under the dominant model (OR = 1.06, 95 % CI 0.98-1.16, P = 0.146). Sensitivity analysis suggested the stability and liability of this meta-analysis. Therefore, this meta-analysis suggests that XRCC1 Arg194Trp polymorphism is associated with increased risk of lung cancer in Chinese Han population. [ABSTRACT FROM AUTHOR]

SESQUITERPENE lactones, CANCER treatment, ESTERS, ANALGESICS, SEDATIVES, MOLECULAR structure, NUCLEAR magnetic resonance spectroscopy, and X-ray diffractometers

The guaianolide ester is a potent inhibitor of cancer cells. Lactucopicrin, a guaianolide, shows analgesic, antitussic, and sedative activities. In order to investigate its structure, ¹H and [sup 13]C NMR and 2D NMR have been carried out at a proton field strength of 400 MHz and a carbon field strength of 100 Mhz in DMSO-d[sub 6] at 20°C. Resonances for all protons and carbons have been assigned. The results of HMQC and HMBC experiments suggest that the structure of lactucopicrin is as shown in Fig. 1. Its stereostructure is verified by the X-ray experiment. ¹H and [sup 13]C NMR of lactucopicrin are reported. Its 2D NMR and X-ray are reported for the first time. KEY WORDS: NMR; HMQC; HMBC; X-ray diffraction; lactucopicrin. [ABSTRACT FROM AUTHOR]

Enzymes exhibit high selectivity and reactivity under normal conditions but are sensitive to denaturation or inactivation by pH and temperature extremes, organic solvents, and detergents. To extend the use of these biocatalysts for practical applications, the technology of immobilization of enzymes on suitable supports was developed. Recently, these immobilized biomolecules have been widely used and a variety of immobilization supports have been studied. The majority of these supports cover diverse kinds of materials such as natural or synthetic polyhydroxylic matrives, porous in organic carriers, and all kinds of functional polymers. Microporous molecular sieve, zeolite, has attracted extensive interest in research because of its distinctive physical properties and geochemistry. Recently, with the discovery of a new family of mesoporous molecular sieves, MCM-41, this series of materials shows great potential for various applications. Molecular sieves involve such a series of materials that can discriminate between molecules, particularly on the basis of size. As support materials, they offer interesting properties, such as high surface areas, hydrophobic or hydrophilic behavior, and electrostatic interaction, as well as mechanical and chemical resistance, making them attractive for enzyme immobilization. In this article, different types of molecular sieves used in different immobilization methods including physical adsorption on zeolite, entrapment in mesoporous and macroporous MCM series, as well as chemically covalent binding to functionalized molecular sieves are reviewed. Key factors affecting the application of this biotechnology are discussed systematically, and immobilization mechanisms combined with newly developed techniques to elucidate the interactions between matrixes and enzyme molecules are also introduced. [ABSTRACT FROM AUTHOR]