Soil burial degradation of new bio‐based additives. Part II. plasticized poly(vinyl chloride) films

Commercial sunflower oil was epoxidized, and the epoxidized oil (ESO) was used as a new thermal stabilizer for poly(vinyl chloride) (PVC). Plasticized formulations stabilized with ESO and epoxidized soya bean oil as a commercial stabilizer were evaluated for comparison. Two plasticizers were used, dioctyl phthalate and diisononyl adipate. The aging of the PVC samples was investigated in landfill soil for 24 months. The modifications of the structure of the polymer were followed by Fourier, transform infrared spectroscopy. Furthermore, the variations of density and mechanical properties (tensile and Shore D hardness) were considered, and the variations of the mass of the samples, the glass transition temperature (T_g), the molar mass distribution, and the weight loss were followed as a function of duration of soil burial. The morphological changes were tracked by scanning electron microscopy. Results showed that the nature of the plasticizer and heat stabilizer affects the properties of PVC as well as the phenomena of migration and biodegradation. J. VINYL ADDIT. TECHNOL., 19:183‐191, 2013. © 2013 Society of Plastics Engineers     

Functional Polymer Brushes on Diamond as a Platform for Immobilization and Electrical Wiring of Biomolecules

For the biofunctionalization of electronic devices, polymer brushes can provide a route which allows combining the advantages of other commonly used approaches, such as immobilization of functional biomolecules via self assembled monolayers or coated polymer matrices: high stability and loading capacity, efficient electron transport, and excellent biocompatibility. In the work presented here, poly(methacrylic acid) brushes are prepared by self‐initiated photografting and photopolymerization on diamond electrodes. In this straightforward process no prior grafting of initiators is required since the initiation of the polymerization can be conveniently controlled by the hydrogen or oxygen termination of the diamond surface. Boron doped nanocrystalline diamond as an electrode material provides extreme chemical inertness and stability, inherent biocompatibility, and superior electrochemical properties, such as the large accessible potential window and low background currents. As a proof of concept we demonstrate the amperometric detection of glucose by polymer brushes covalently modified with the redox enzyme glucose oxidase and aminomethyl ferrocene as electron mediator. Characterization by X‐ray photoelectron spectroscopy and atomic force microscopy both indicate a high loading of the ferrocene mediator. Consistently, electrochemical cyclic voltammetry shows a multilayer equivalent loading of ferrocene and highly efficient electron transfer throughout the polymer film. Overall, functionalized polymer brushes can provide a promising platform for the immobilization and electrical wiring of biomolecules for bioelectronic and biosensing applications.     

Protective Effects of Anthocyanins in Obesity‐Associated Inflammation and Changes in Gut Microbiome

Obesity is a complex disease and a major public health epidemic. Chronic, low‐grade inflammation is a common underlying feature of obesity and associated metabolic diseases; adipose tissue is a major contributor to this systemic inflammation. Evidence shows that obesity‐associated inflammation may originate from gut dysfunction, including changes in intestinal bacteria or microbiome profiles. Increasingly, food and plant bioactive compounds with antioxidant and anti‐inflammatory properties are proposed to ameliorate obesity‐associated inflammation. Among these, the health‐promoting effects of anthocyanin‐rich foods are of interest here. Specifically, this review summarizes the reported benefits of anthocyanins in obesity‐associated inflammation and underlying molecular mechanisms, including the role of gut microbiome and cell signaling pathways regulated by anthocyanins both in vivo and in vitro.     

Microstructure and Mechanical Behavior in Dissimilar SAF 2205/API X52 Welded Pipes

The welding of a duplex stainless steel SAF 2205 DSS(UNS 31803) and high strength low alloy steel API X52 by shielded metal arc welding process was conducted using two different filler metals,the duplex E2209 and austenitic E309 grade.The microstructures of the dissimilar metal joints have been investigated by optical microscopy,scanning electron microscopy,energy-dispersive spectroscopy(EDS) and X-ray diffraction.EDS analysis at the interface X52 weld metal showed an evident gradient variation of Cr and Ni between boundaries of fusion and type II,where the highest hardness value was recorded.Tensile strength and toughness values of the weld metal produced by E309 electrode are slightly higher than those of the weld metal produced by E2209 electrode.Potentiodynamic polarization tests of different regions of the welded joints evaluated in 3.5%NaCl solution exhibit a high corrosion resistance of both weld metals.     

Antioxidant and gastroprotective actions of butanol fraction of Zingiber officinale against diclofenac sodium‐induced gastric damage in rats

This study was designed to investigate the antioxidant and antiulcer activities of flavonoid‐rich fractions of Zingiber officinale extract. The fractions, obtained by solvents of increasing polarities, were subjected to 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity. The fraction which possessed the highest antioxidant activity was used to assess gastroprotective action against diclofenac sodium induced gastric ulcer in rats. Chromatographic profiling was carried out using LC‐ESI‐MS analysis. The butanol fraction (BF) showed the strongest antioxidant potential and the results of the in vivo study revealed that BF at 100 mg/kg protected against gastric lesions. At the same dose, BF prevented diclofenac sodium‐induced increase in tumor necrosis factor alpha (TNF‐α) and malondialdehyde (MDA) levels, and depletion of catalase (CAT) activity as well as glutathione (GSH) and prostaglandin E2 (PGE2) contents. LC‐ESI‐MS analysis revealed the presence of 12 phenolic compounds. BF exerted antiulcer action which could be linked to the presence of phenolic compounds.

Practical applications

Zingiber officinale has been widely consumed as a spice and used in folk medicine for treatment of gastric disorders. This is the first report evaluating the pharmacological effects of the butanol extract of ginger for the prevention of gastric ulcer. The results showed that the extract affords better gastroprotective activity against diclofenac sodium‐induced gastric ulcer in rats by reducing oxidative stress. Information provided in this study will be beneficial for developing applications of ginger in food biotechnology as functional and nutraceutical ingredient.     

Low Power Circuit and System Design Hierarchy and Thermal Reliability of Tunnel Field Effect Transistor

Silicon - Tunnel FET is one of the promising devices advocated as a replacement of conventional MOSFET to be used for low power applications. Temperature is an important factor affecting the...