Plastic Antibodies for Cosmetics: Molecularly Imprinted Polymers Scavenge Precursors of Malodors

Molecularly imprinted polymers (MIPs) are synthetic antibody mimics capable of specific molecular recognition. Advantageously, they are more stable, easy to tailor for a given application and less expensive than antibodies. These plastic antibodies are raising increasing interest and one relatively unexplored domain in which they could outplay these advantages particularly well is cosmetics. Here, we present the use of a MIP as an active ingredient of a cosmetic product, for suppressing body odors. In a dermo‐cosmetic formulation, the MIP captures selectively the precursors of malodorous compounds, amidst a multitude of other molecules present in human sweat. These results pave the way to the fabrication of a novel generation of MIPs with improved selectivities in highly complex aqueous environments, and should be applicable to biotechnological and biomedical areas as well.     

Optimization of Chlorophyllase-catalyzed Hydrolysis of Chlorophyll in Monophasic Organic Solvent Media

The effects of selected reaction parameters, including solvent hydrophobicity, initial water activity, agitation speed, temperature and enzyme concentration, on the biocatalytic efficiency of a chlorophyllase enzymatic extract from Phaeodactylum tricornutum in neat organic solvent media were investigated. The highest chlorophyllase specific activity of 322 nmol hydrolyzed chlorophyll per gram of protein per minute and bioconversion yield of 91% were obtained in the reaction mixture of hexane/2-octanone (98.3:1.7, v/v), at a controlled initial water activity of 0.90. R _O/A value, which is the ratio of the specific activity in the organic solvent to that in the aqueous/miscible organic solvent medium, was 1.5 × 10⁻³. To reduce the substrate diffusional limitations, the appropriate agitation speed and enzyme concentration were determined. The optimum temperature for maximal enzymatic activity and activation energy were 35°C and 105.0 kJ/mol, respectively. Although the catalytic efficiency of chlorphyllase in the neat organic solvent mixture was lower than that in the aqueous medium, its half-life time in the first environment at temperature ranging from 35 to 50°C was increased by 5.0 to 15.0 times.     

Design and analysis of the effect of Zeonex based octagonal photonic crystal fiber for different types of communication applications

Optical and Quantum Electronics - Orthogonal frequency division multiplexing (OFDM) of the optical communication system is a known approach for light fidelity and the screen-to-a-camera (S2C)...     

微流控芯片在食品安全分析中的应用进展

微流控芯片技术可以实现从样品处理到检测的微型化、自动化、集成化及便携化,因而在食品安全检测方面展现出强大的发展活力。目前微流控芯片技术在农药残留、兽药残留、重金属、食品添加剂等食品安全检测方面已取得了一系列重要进展。该文着重介绍了微流控芯片技术在食品安全分析中的研究进展,并展望了其在食品安全分析中的应用前景。     

Large-scale simulations and parameter study for a simple recrystallization model

Distance function-based diffusion-generated motion, a highly efficient numerical algorithm, is used to simulate a classical model of recrystallization in unprecedented detail and in physically relevant parameter regimes not attainable with many previous techniques. The algorithm represents interfaces implicitly and is closely related to the level set method. In particular, it allows for automatic topological changes and arbitrarily large time-steps. Large-scale simulations of recrystallization for physically relevant parameter values are presented in detail. In addition, new analytical estimates for the distribution of surviving nuclei are obtained and compared with the numerical results.     

Spectroscopic analysis of irradiated erythrocytes

The aim of the present work is to study the effect of gamma radiation on the lipid part of the erythrocyte membrane, and to test the efficiency of lipoic acid as a radioprotector. This effect was evaluated using electron paramagnetic resonance (EPR), and Fourier transform infrared (FT-IR) spectroscopy. The results showed an increase in the number of spin density by 14%, 22% and 65% after exposure to 25, 50 and 100 Gy respectively; whereas there was a decline in the obtained density after incubation with lipoic acid by a factor of approximately 32%. The FT-IR spectra of the irradiated erythrocytes samples showed a marked decrease in the intensity of all characteristic peaks, which increased as the irradiation dose increased. The second-derivative of these spectra, allow the conformationally sensitive membrane acyl chain methylene stretching modes to be separated from the protein (mostly hemoglobin) vibrations that dominate the spectra of intact cells. The 2850 cm⁻¹ band showed changes in the band shape and position after exposure to 50 and 100 Gy. Therefore it can be concluded that the band at 2850 cm⁻¹ only is useful in monitoring the radiation effect of the lipids cell membrane intact cells.     

基于可视化学传感阵列的农药快速检测新方法

采用可视化阵列传感技术,以卟啉及其衍生物和指示剂作为传感元件,构建了一种对农药敏感的可视化学传感阵列。该传感阵列可以在常温常压下对浓度为0.1 mg/L的12种农药快速识别和分类,反应时间仅为1.5 min。采用聚类分析(HCA)和主成分分析(PCA)等统计学分析方法对检测结果进行分析,不同种类农药样品在聚类分析和主成分分析中均可以被准确归类。     

Rhodium-catalyzed reductive cyclization of 1,6-enynes and stereoselective synthesis of the putative structure of lucentamycin A and its stereoisomers

A Rh-catalyzed diastereoselective reductive cyclization, mediated by hydrogen, of optically active 1,6-enynes using chiral BINAP was successfully applied to the total synthesis of four stereoisomers of the proposed structure of lucentamycin A. In order to synthesize two of these four stereoisomers, we successfully constructed chiral proline derivatives bearing cis-carbon substituents at C2 and C3 positions based on Krische’s methodology, which has very rarely been reported. Anti-proliferative activities on HCT-116 cell line and NMR data of these four stereoisomers were compared with those of naturally occurring lucentamycine A. The results show that the proposed structure of lucentamycin A needs revision.     

Novel thermostable and alkalitolerant amylase production by Geobacillus stearothermophilus HP 3

This study reports the production and characterisation of a novel thermostable alkaline amylase from the newly isolated Geobacillus stearothermophilus HP 3. The optimum temperature and pH for enzyme production was 55°C and 9.0, respectively. The amylase powder obtained from the culture filtrate by pre-chilled acetone treatment was stable over a wide pH range and liquefied thick starch slurries at 75°C. Ca2? and Co2? were required for the thermostability of the enzyme preparation. The present purified amylase therefore could be defined as thermostable and alkalitolerant with new properties that make the enzyme applicable for many starch processing applications for use in the food industry.