Multi‐responsive microgel of a water‐soluble monomer via emulsion polymerization

Microgel of a water‐soluble monomer [2‐(N‐morpholino)ethyl methacrylate (MEMA)] was successfully prepared in aqueous media via emulsion polymerization by using a novel water‐soluble block copolymer as stabilizer. Characterization studies confirmed monodisperse spherical morphologies of microgels with a diameter of 280 nm at neutral pH. These microgels exhibited multi‐responsive behavior by responding solution pH, temperature, ionic strength, type of dispersing media, and magnetic particles. It swells well at low pH (<6.0) and at low temperature, but shrinks above pH 6.0, or even more shrinks with salt addition at neutral and basic conditions. In addition, the hydrodynamic diameter of PMEMA microgel was decreased gradually at basic and neutral pH when solution temperature was increased up to the lower critical solution temperature of PMEMA (LCST, 35°C), but microgel diameter did not change much above LCST. Multi‐responsive behavior of PMEMA microgel was investigated by using dynamic light scattering, UV‐Vis spectrophotometer and zeta potentiometer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42072.     

Electrochemical synthesis and characterization of a new soluble conducting polymer

Electroactive poly(4-methyl carbazole-3-carboxylic acid) (PMCCA) film was formed on Pt electrode surface by oxidative electropolymerization of a new carbazole derivative. The structure of the soluble polymer was elucidated by nuclear magnetic resonance (¹H and ¹³C NMR) and Fourier transform infrared (FTIR) spectroscopy. The average molecular weight has been determined by gel permeation chromatography (GPC) to be M _n = 51,000 for the electrochemically synthesized polymer. Characterizations of the resulting polymer were performed by cyclic voltammetry, dry conductivity measurement, scanning electron microscopy, and UV-vis spectroscopy. Spectroelectrochemical studies indicated that PMCCA films revealed a green color in the oxidized state and a high transmittance in the neutral state. The conductivities of PMCCA are in the range of 10⁻⁵–10⁻⁴ S cm⁻¹.     

Al Hamra塔,科威特

Al Hamra塔坐落于科威特市,是一座包含有办公空间、健身俱乐部、剧院、美食广场的高端商业中心的商业综合体。建筑高度达到412m。这座标志性的写字楼将成为科威特市最高的建筑。Al Hamra塔的建设目前已经接近尾声,办公面积达到18.6万m2,其旁边是一座由当地建筑师设计的面积达3.4万m2的商业裙房。该项目的业主是一位当地开发商和一位总承包商,但建造一座超高层建筑却并不是他们的初衷。事实上,在项目之初他们已经开始动工建造一座由当地建筑师设计的50层高的塔楼     

Development of Degradable,pH‐Sensitive Star Vectors for Enhancing the Cytoplasmic Delivery of Nucleic Acids

The report describes the synthesis of degradable, pH‐sensitive, membrane‐destabilizing, star‐shaped polymers where copolymers of hydrophobic hexyl methacrylate (HMA) and 2‐(dimethylamino)ethyl methacrylate (DMAEMA) monomers are grafted from the secondary face of a beta‐cyclodextrin (β‐CD) core via acid‐labile hydrazone linkages using atom transfer radical polymerization. The effect of the graft's molecular weight, HMA/DMAEMA molar ratio, and the fraction of DMAEMA converted to cationic N,N,N‐trimethylaminoethyl methacrylate (TMAEMA) monomers on polymer's transfection capacity is systematically investigated. Results show that all star‐shaped polymers condense anti‐GAPDH silencing RNA (siRNA) into nanosized particles at +/‐ ratio ≤ 4:1. Star polymers with shorter (25kDa) P(HMA‐co‐DMAEMA‐co‐TMAEMA) grafts are more efficient and less cytotoxic than carriers with longer (40kDa) grafts. The results show that increasing the ratio of hydrophobic HMA monomers in graft's composition higher than 50 mole% dramatically reduces polymer's aqueous solubility and abolishes their transfection capacity. Further, retention of DMAEMA monomers in graft's composition provide a buffering capacity that enhanced the endosomal escape and transfection capacity of the polymers. These systematic studies show that β‐CD‐P(HMA‐co‐DMAEMA‐co‐TMAEMA)_4.8 polymer with a 25 kDa average graft's molecular weight and a 50/25/25 ratio of HMA/DMAEMA/TMAEMA monomers is the most efficient carrier in delivering the siRNA cargo into the cytoplasm of epithelial cancer cells.     

Effects of essential oils on the survival of Salmonella Enteritidis and Listeria monocytogenes on fresh Atlantic salmons (Salmo salar) during storage at 2 ± 1 °C

In this study, the effects of coriander, garlic, rosemary, and orange peel oils on the survival of Salmonella Enteritidis and Listeria monocytogenes were examined 2 ± 1 °C during storage of inoculated fresh Atlantic salmon samples (96 hr). At the end of storage population decrease in Salmonella Enteritidis was significantly lower (p < .05) in the essential oil groups compared with control group. Salmonella Enteritidis count of rosemary oil treated group was higher than (p < .05) other groups (coriander, garlic, and orange peel oils) at the end of storage. Essential oils decreased the population of L. monocytogenes while the population in untreated samples were higher at the end of storage period (p < .05). Results of this study indicated that treatment of salmon fish samples with essential oils may be an effective natural antimicrobial application to control Salmonella Enteritidis and L. monocytogenes.

Practical applications

In the present study, it was concluded that essential oils had an antimicrobial effect Salmonella Enteritidis and Listeria monocytogenes. Use of essential oils during storage of fish or fish products may play an important role against Salmonella Enteritidis and L. monocytogenes. Essential oils are easily applicable and a cheaper method. The results of this experiment propose that addition of essential oils to fish flesh can be recommended to seafood processors and fish market retailers.     

Enhancement of Electrical Conductivity of Polyethylene Terephthalate (PET) Fabrics via Ionic Liquids

In this study, polyethylene terephtalate (PET) fabrics were treated with two types of ionic liquids, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate (EIL) and methyl-tri-n-butylammonium methyl sulfate (BIL), resulting in noticeably better long-term electrical conductivity of treated PET fabrics. Thermal conductivity, thermal stability, surface morphology and chemical structure were also explored. The effects of concentration of EIL (2, 6, 10 w/v %) and BIL (10, 15, 20 w/v %) ionic liquids were discussed. With the given set up, surface resistivities of the PET fabrics decreased with treatment application of the ionic liquids. Besides, BIL treatment provided higher electrical conductivity as compared with EIL. Moreover, surface resistivity presented diminishing tendency with increasing the concentration. It is also found that thermal degradation temperatures of the PET fabrics decreased with ionic liquids treatment. A coating layer was observable on surface of the fabric and in the gaps of the yarns with the ionic liquids treatment. This work provided a novel method for obtaining enhanced electrically conductive PET fabrics for textile industry.     

ICP-MS analysis of a series of metals (Namely: Mg,Cr, Co,Ni, Fe,Cu, Zn,Sn, Cd and Pb) in black and green olive samples from Bursa,Turkey

Ninety-two black and green table olive samples from the Bursa, Turkey were analyzed. The olives were sampled from 56 brands, four processing methods and three packing types. The concentration of Mg, Cr, Co, Ni, Fe, Cu, Zn, Sn, Cd and Pb were measured by inductively coupled plasma mass spectrometry (ICP-MS). While the most concentrated element was Mg (125.11 ± 5.02), Co (0.09 ± 0.01) had the lowest concentration in tested olive samples. The levels of the ten metals studied are within safe limits. The data here obtained will be valuable in complementing available food composition data, and estimating dietary intakes of heavy metals in Turkey. The metals Mg, Fe, Zn, Sn and Pb presented significant differences (p < 0.05) in content between two types, hence processing method, brand and packing material must influence their content.     

Hilbert–Huang Transform Based Approach for Measurement of Voltage Flicker Magnitude and Frequency

Voltage flicker is a non-stationary waveform for which direct spectral analysis is not appropriate. To overcome this difficulty, a Hilbert–Huang transform based technique is proposed here. Hilbert–Huang transform is a new signal processing method that can be used in the analysis of non-linear and non-stationary signals. In the suggested method, the recorded voltage signal is decomposed into Hilbert–Huang transform components, namely the empirical mode decomposition and intrinsic mode function components. These components are used in the calculation of the frequency and amplitude of voltage flicker. The clear success of empirical mode decomposition in depicting envelope variations of a sinusoidal waveform has been the main motivation for the adoption of Hilbert–Huang transform in flicker analysis. Simulations are performed over waveforms, including single- and multiple-flicker frequencies and flicker with harmonic, voltage sag, and voltage swell. The waveforms are selected as pure sinusoids, as well as harmonically rich voltage waveforms. Simulation results show that the proposed methodology constitutes a plausible way to analyze voltage flickers, making it an alternative to the available flicker analysis tools.     

Influence of dopant concentration on the optical properties of ZnO: In films by sol-gel method

Undoped and In doped ZnO films have been deposited by sol-gel spin coating method. The effect of indium incorporation on structural and optical properties of ZnO films has been investigated. X-ray diffraction patterns of the films showed the hexagonal wurtzite type polycrystalline structure and that indium incorporation leads to substantial changes in the structural characteristics of ZnO films. The SEM and AFM measurements showed that the surface morphology of the films was affected from the indium incorporation. Optical reflectance and transmittance were recorded with a double beam spectrophotometer with an integrating sphere. The optical band gap of these films was determined. The absorption edge shifted to the lower energy depending on the dopant materials. The optical constants of these films were determined using transmittance and reflectance spectra.