Heteropoly acid catalyzed synthesis of 8-methyl-2-aryl/alkyl-3-oxabicyclo[3.3.1]non-7-ene derivatives through (3,5)-oxonium-ene reaction

A variety of aldehydes undergo a smooth coupling with (4-methylcyclohex-3-en-1-yl)methanol in the presence of 2 mol % of phosphomolybdic acid in dichloromethane to afford 3-oxabicyclo[3.3.1]non-7-ene in good yields through 3,5-oxonium-ene cyclization under mild conditions. The use of inexpensive, nontoxic, and readily available heteropoly acid catalyst makes this method simple, convenient, and environmental-friendly.     

纳米金标记抗体增强SPR检测大肠杆菌O157∶H7

将金纳米粒子(AuNPs)标记的大肠杆菌O157∶H7(E.coli O157∶H7)的多克隆抗体(PAb)作为二抗,采用氨基偶联法将PAb固定在传感器表面作为一抗,通过三明治方法用双通道表面等离子体子共振(SPR)传感器对E.coli O157∶H7进行检测,并与SPR直接法检测进行了比较.结果表明,直接法的检出限为103cfu/mL,线性范围为103～109cfu/mL;AuNPs增强三明治法的检出限为10 cfu/mL,线性范围为10～1010cfu/mL,灵敏度比直接法提高了100倍,且具有更宽的检测范围.本方法不仅检测时间短,而且具有良好的选择性和重现性.     

Photochromic reverse mode polymer dispersed liquid crystals

Control of light intensity and colour are two of the major features required in the realization of smart windows. We designed a bi‐functional polymer dispersed liquid crystal (PDLC) film in order to satisfy such requirements, i.e. it is able both to modulate the optical transmission, if an external electric field is applied, and to change colour if exposed to sunlight. A monomer/liquid crystal mixture was doped with a small amount of photochromic material and homeotropically aligned by means of rough surfaces. A transparent and pale pink coloured film was achieved after photopolymerization. Such a film changes colour upon exposure for some seconds to sunlight or ultraviolet radiation in a persistent but reversible manner. In addition, the film appears transparent without the application of an electric field (OFF state) and becomes opaque on application of a driving voltage of about 75?V (ON state), and thus the film operates in reverse mode with respect to conventional PDLCs.     

Application of Non-Destructive X-Ray Fluorescence Spectrometry to the Analysis of Suspended Matter in Sea Water

Abstract

In the framework of remote sensing studies concerning coastal transport of pollution in the Northern Adriatic Sea, a method has been developed for the quantitative determination of sulphur, iron, titanium, calcium, phosphorus, silicon, aluminium, magnesium in suspended matter of sea water.

The suspended material was collected by filtering on millipore membrane filters with pore width of 0.45 μ and directly analysed by X-ray spectroscopy. For calibration dried solution and particulate standard samples were used. Limits of sensitivity and precision of the method are reported.

Correlations between the concentration of these elements and the total suspended matter/chlorophyll are discussed.

The aim is to study the geochemical composition of particulate matter and its variations within the geographical site of the sea basin and the seasonal conditions. The approach is to consider aluminium and the other elements normalized on Al. On the basis of a matrix correlation analyses of some sets of data chosen in the restricted area for investigation, some hypothesis on superficial distribution of clay, carbonate, iron hydrous oxides and other mineral detrites, are taken into account. The results confirm the complex situation existing in the offshore area of the Venice lagoon from a geochemical point of view.

The suspended matter seem to be argillaceous in the Southern part of the investigated area and semi-argillaceous with hydrous oxides and carbonates in the Northern part which is influenced by the Piave river.     

Cucurbit[7]uril promoting PdCl2-catalyzed cross-coupling reaction of benzyl halides and arylboronic acids in aqueous media

The research provides a novel approach for producing diarylmethane derivatives using CB[7]–NaCl–PdCl₂ catalyzed Suzuki cross-coupling reaction of benzyl chloride derivatives and arylboronic acids in ethanol aqueous solution.     

Electrochemical behavior in simulated body fluid of TiO2 nanotubes on TiAlNb alloy elaborated in various anodizing electrolyte

The present study is focused on tailoring the morphology of TiO₂ nanotubes obtained on Ti6Al7Nb alloy and evaluating their electrochemical behavior in simulated body fluid. The presence of the α and β phases on the Ti6Al7Nb alloy leads to a two‐scale organization of the nanotubes on the samples – which in turn affects the electrochemical stability. Furthermore, five different types of TiO₂ nanotubes were obtained in various electrolytes (e.g. Generation I, a mixture of Generation II and Generation III, Generation III). Electrochemical behavior analysis of all obtained nanotubes morphologies was composed of Tafel plots, cyclic voltammetry and electrochemical impedance spectroscopy and was correlated with morphology data obtained from SEM (nanotubes diameters from top‐view and nanotube length from cross‐section view). The electrochemical results showed that morphological modifications of the Ti6Al7Nb alloy's surface by electrochemical anodizing have induced changes to the electrochemical behavior of the material, evident in the corrosion rates. Copyright © 2014 John Wiley & Sons, Ltd.     

Exploration of the mechanism of Zisheng Shenqi decoction against gout arthritis using network pharmacology

BackgroundIn this study, the network pharmacological methods were used to predict the target of effective components of compounds in Zisheng Shenqi Decoction (ZSD, or Nourishing Kidney Qi Decoction) in the treatment of gouty arthritis (GA).MethodThe main effective components and corresponding key targets of herbs in the ZSD were discerned through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis (TCMSP), Bioinformatics Analysis Tool for Molecular mechanism of Traditional Chinese Medicine (BATMAN-TCM) database. UniProt database and Swiss Target Prediction (STP) database was used to rectify and unify the target names and supply the target information. The targets related to GA were obtained by using GeneCards database. After we discovered the potential common targets between ZSD and GA, the interaction network diagram of “ZSD-component-GA-target” was constructed by Cytoscape software (Version 3.7.1). Subsequently, the Protein-protein interaction (PPI) network of ZSD effective components-targets and GA-related targets was constructed by Search Tool for the Retrieval of Interacting Genes Database (STRING). Bioconductor package “org.Hs.eg.db” and “cluster profiler” package were installed in R software (Version 3.6.0) which used for Gene Ontology analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis.Results146 components and 613 targets of 11 herbal medicines in the ZSD were got from TCMSP database and BATMAN-TCM database. 987 targets of GA were obtained from GeneCards database. After intersected and removed duplications, 132 common targets between ZSD and GA were screened out by Cytoscape software (Version 3.7.1). These common targets derived from 81 effective components of 146 components, such as quercetin, stigmasterol and kaempferol. They were closely related to anti-inflammatory, analgesic and anti oxidative stress and the principal targets comprised of Purinergic receptor P2X, ligand-gated ion channel 7 (P2x7R), Nod-like receptor protein 3 (NLRP3) and IL-1β. GO enrichment analysis and KEGG pathway enrichment analysis by R software (Version 3.6.0) showed that the key target genes had close relationship with oxidative stress, reactive oxygen species (ROS) metabolic process and leukocyte migration in aspects of biological process, cell components and molecular function. It also indicated that ZSD could decrease inflammatory reaction, alleviate ROS accumulation and attenuate pain by regulating P2 × 7R and NOD like receptor signaling pathway of inflammatory reaction.ConclusionA total of 81 effective components and 132 common target genes between ZSD and GA were screened by network pharmacology. The PPI network, GO enrichment analysis and KEGG pathway enrichment analysis suggested that ZSD can exerte anti-inflammatory and analgesic effects on the treatment of GA by reducing decreasing inflammatory reaction, alleviating ROS accumulation, and attenuating pain. The possible molecular mechanism of it mainly involved multiple components, multiple targets and multiple signaling pathways, which provided a comprehensive understanding for further study. In general, the network pharmacological method applied in this study provides an alternative strategy for the mechanism of ZSD in the treatment of GA.     

Nanoscale observations of the operational failure for phase-change-type nonvolatile memory devices using Ge2Sb2Te5 chalcogenide thin films

In this study, a phase-change memory device was fabricated and the origin of device failure mode was examined using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Ge₂Sb₂Te₅ (GST) was used as the active phase-change material in the memory device and the active pore size was designed to be 0.5 m. After the programming signals of more than 2×10⁶ cycles were repeatedly applied to the device, the high-resistance memory state (reset) could not be rewritten and the cell resistance was fixed at the low-resistance state (set). Based on TEM and EDS studies, Sb excess and Ge deficiency in the device operating region had a strong effect on device reliability, especially under endurance-demanding conditions. An abnormal segregation and oxidation of Ge also was observed in the region between the device operating and inactive peripheral regions. To guarantee an data endurability of more than 1×10¹⁰ cycles of PRAM, it is very important to develop phase-change materials with more stable compositions and to reduce the current required for programming.     

Multifractal detrended fluctuation analysis of derivative and spot markets

We investigate the multifractal properties of price increments in the cases of derivative and spot markets. Through the multifractal detrended fluctuation analysis, we estimate the generalized Hurst and the Renyi exponents for price fluctuations. By deriving the singularity spectrum from the above exponents, we quantify the multifractality of a financial time series and compare the multifractal properties of two different markets. The different behavior of each agent-group in transactions is also discussed. In order to identify the nature of the underlying multifractality, we apply the method of surrogate data to both sets of financial data. It is shown that multifractality due to a fat-tailed distribution is significant.     

Decay rate with coordinate-dependent diffusion coefficients

Using a master equation for the reduced density matrix of open quantum system, the influence of coordinate-dependent microscopical diffusion coefficients on the decay rate from a potential well is studied. For different temperatures, frictions, heights of barrier and ratios of stiffnesses of the potential in the minimum and on the top of the barrier, the quasistationary decay rates are obtained with the sets of coordinate-dependent and -independent microscopical diffusion coefficients, and coordinate-dependent phenomenological diffusion coefficients.