Thickness and annealing temperature effects on the optical properties and surface morphology of layer‐by‐layer poly(p‐phenyline vinylene)+dodecylbenzenesulfonate films

The fabrication of controlled molecular architectures is essential for organic devices, as is the case of emission of polarized light for the information industry. In this study, we show that optimized conditions can be established to allow layer‐by‐layer (LbL) films of poly(p‐phenylene vinylene) (PPV)+dodecylbenzenesulfonate (DBS) to be obtained with anisotropic properties. Films with five layers and converted at 110 °C had a dichroic ratio δ = 2.3 and order parameter r = 34%, as indicated in optical spectroscopy and emission ellipsometry data. This anisotropy was decreased with the number of layers deposited, with δ = 1.0 for a 75‐layer LbL PPV + DBS film. The analysis with atomic force microscopy showed the formation of polymer clusters in a random growth process with the normalized height distribution being represented by a Gaussian function. In spite of this randomness in film growth, the self‐covariance function pointed to a correlation between clusters, especially for thick films. In summary, the LbL method may be exploited to obtain both anisotropic films with polarized emission and regular, nanostructured surfaces. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

TL properties of anhydrous CaSO4:Tm improvement

CaSO4:Tm is excellent phosphors for dosimetry of ionising radiations due to their high sensitivity, wide dose range (from 10^?6 to 1 Gy), relatively simple trap structure, good chemical, thermal and physical stability and ease of preparation. Since 1968 have been developed new methods of preparing aim to increase the sensitivity and the linearity of the CaSO₄:Tm thermoluminescence. The objective of this work is to obtain single crystals of CaSO₄:Tm under controlled crystal growth conditions, such as temperature, atmosphere and velocity, aiming to improve the TL sensitivity of the crystals and investigate its dosimetric properties in order to evaluate the applicability of this material to dosimetry.     

In vitro photodynamic inactivation of Candida spp. growth and adhesion to buccal epithelial cells

In this study, photodynamic inactivation (PDI) was used to inhibit in vitro growth and adhesion of different Candida isolates to buccal epithelial cells (BEC). Experimental conditions were optimized and 25 μM toluidine blue O (TBO) and 15 min of irradiation time by light emitting diode (LED) (energy density of 180 J/cm²) were selected due to higher reductions in cellular viability obtained after treatment. Reduction media of Log₁₀ 3.41 in viable cellular growth and media of 55% in the inhibition of adhesion to buccal epithelial cells were obtained. Two fluconazole resistant isolates were susceptible to PDI (Log₁₀ 3.54 in IB05 and Log₁₀ 1.95 in CG09) and a second session of this treatment for CG09 isolate inhibited cellular viability in 100%, without producing heat. The results permit to conclude that photodynamic inactivation under these experimental conditions would be a possible alternative approach to inhibit Candida spp. cellular growth and adhesion to buccal epithelial cells.     

Phenolic characterization of Northeast Portuguese propolis: usual and unusual compounds

In this study, an ethanolic extract from Portuguese propolis was prepared, fractionated by high-performance liquid chromatography, and the identification of the phenolic compounds was done by electrospray mass spectrometry in the negative mode. This technical approach allowed the identification of 37 phenolic compounds, which included not only the typical phenolic acids and flavonoids found in propolis from temperate zones but also several compounds in which its occurrence have never been referred to in the literature. Four of the novel phenolic compounds were methylated and/or esterified or hydroxylated derivatives of common poplar flavonoids, although six peculiar derivatives of pinocembrin/pinobanksin, containing a phenylpropanoic acid derivative moiety in their structure, were also identified. Furthermore, the Portuguese propolis sample was shown to contain a p-coumaric ester derivative dimer.     

1-乙酰乙酰基-3-甲基吲哚对稀土离子能量传递过程研究

通过1-乙酰乙酰基-3-甲基吲哚(I3MK)与各种稀土离子在77K乙醇刚性溶液体系中的荧光光谱、磷光光谱的测定,进行了I3MK向稀土离子能量传递过程的静态分析;从I3MK和I3MK-Tb(Ⅲ)体系的荧光寿命、磷光寿命、量子产率,时间分辨光谱等,计算了各主要能量传递过程的速率常数和能量传递效率,进行了该体系能量传递过程的动态分析,提出了Perrin公式的修正参数,讨论了I3MK-Tb(Ⅲ)体系的能量传递机理.     

Production of an antiproliferative furanoheliangolide by Lychnophora ericoides cell culture

This work reports for the first time the production a furanoheliangolide (goyazensolide) by plant cell culture. Monitoring of the goyazensolide metabolism revealed that the maximum production occurred during the lag phase of the Lychnophora ericoides callus culture. The antiproliferative activity of obtained goyazensolide was evaluated against seven cancer cell lines using MTT assay. The results revealed a potent cytotoxic activity for the furaheliangolide with IC50 values in the range of 0.06 microg/ml for CEM leukemia cells to 0.75 microg/ml for B16 melanome cells.     

小鼠血清,全血和鼠毛中的元素含量研究

报告了健康Ｃ５７ＢＬ小鼠血清，全血和鼠毛中９种元素含量。在３种生物样品中测定的元素以鼠毛中含量最高，血清中最低，本文讨论了小鼠和人的血清和毛发元素水平之间的关系，Ｃ５７ＢＬ小鼠作为研究元素和疾病关系的实验动物有其优点。     

聚焦强激光束大气传输的数值模拟

 用非自适应坐标变换技术求解聚焦强激光束大气传输的热晕问题，实践表明对提高计算精度和速度十分有效，但在焦平面附近的计算，由于热晕的散焦作用，原有技术有一定困难。通过提出一种改进的非自适应坐标变换技术，克服了原有变换的缺陷，有效提高了计算精度和速度，并减少了计算机内存的占用。     

Development and evaluation of microencapsulated sunscreen

The aim of the present study was to carry out stability tests and in vitro sun protection factor (SPF) evaluations of formulations containing free or microencapsulated chemical sun filters to improve their use. To this end, three formulations were developed and subjected to stability studies. The most stable formulation was chosen as a vehicle for free and microencapsulated chemical sun filters, and subjected to further stability studies and in vitro SPF assays. The SPF values were approximately 12 and 11 for formulations containing free and encapsulated sun filters, respectively, and both types were stable under stress. Chemical sun filters can be microencapsulated, which may aid in generating innovative sunscreen formulations.     

On hamiltonian cycles in the prism over the odd graphs

The Kneser graph K(n, k) has as its vertex set all k‐subsets of an n‐set and two k‐subsets are adjacent if they are disjoint. The odd graph O_k is a special case of Kneser graph when n = 2k + 1. A long standing conjecture claims that O_k is hamiltonian for all k>2. We show that the prism over O_k is hamiltonian for all k even. © 2010 Wiley Periodicals, Inc. J Graph Theory 68:177‐188, 2011