Receipt of Jacob Franks for silver from Curaçao towards building synagogue in New York

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Antimicrobial efficacy of a novel silver hydrogel dressing compared to two common silver burn wound dressings: Acticoat™ and PolyMem Silver

A novel burn wound hydrogel dressing has been previously developed which is composed of 2-acrylamido-2-methylpropane sulfonic acid sodium salt with silver nanoparticles. This study compared the antimicrobial efficacy of this novel dressing to two commercially available silver dressings; Acticoat™ and PolyMem Silver(®). Three different antimicrobial tests were used: disc diffusion, broth culture, and the Live/Dead(®) Baclight™ bacterial viability assay. Burn wound pathogens (P. aeruginosa, MSSA, A. baumannii and C. albicans) and antibiotic resistant strains (MRSA and VRE) were tested. All three antimicrobial tests indicated that Acticoat™ was the most effective antimicrobial agent, with inhibition zone lengths of 13.9-18.4mm. It reduced the microbial inocula below the limit of detection (10(2)CFU/ml) and reduced viability by 99% within 4h. PolyMem Silver(®) had no zone of inhibition for most tested micro-organisms, and it also showed poor antimicrobial activity in the broth culture and Live/Dead(®) Baclight™ assays. Alarmingly, it appeared to promote the growth of VRE. The silver hydrogel reduced most of the tested microbial inocula below the detection limit and decreased bacterial viability by 94-99% after 24h exposure. These results support the possibility of using this novel silver hydrogel as a burn wound dressing in the future

Peroxidases in lignifying xylem of Norway spruce, Scots pine and silver birch

Lignin is a complex plant polymer synthesized through co-operation of multiple intracellular and extracellular enzymes. It is deposited to plant cell walls in cells where additional strength or stiffness are needed, such as in tracheary elements (TEs) in xylem, supporting sclerenchymal tissues and at the sites of wounding. Class III peroxidases (POXs) are secreted plant oxidoreductases with implications in many physiological processes such as the polymerization of lignin and suberin and auxin catabolism. POXs are able to oxidize various substrates in the presence of hydrogen peroxide, including lignin monomers, monolignols, thus enabling the monolignol polymerization to lignin by radical coupling. Trees produce large amounts of lignin in secondary xylem of stems, branches and roots. In this study, POXs of gymnosperm and angiosperm trees were studied in order to find POXs which are able to participate in lignin polymerization in developing secondary xylem i.e. are located at the site of lignin synthesis in tree stems and have the ability to oxidize monolignol substrates. Both in the gymnosperm species, Norway spruce and Scots pine, and in the angiosperm species silver birch the monolignol oxidizing POX activities originating from multiple POX isoforms were present in lignifying secondary xylem in stems during the period of annual growth. Most of the partially purified POXs from Norway spruce and silver birch xylem had highest oxidation rate with coniferyl alcohol, the main monomer in guaiacyl-lignin in conifers. The only exception was the most anionic POX fraction from silver birch, which clearly preferred sinapyl alcohol, the lignin monomer needed in the synthesis of syringyl-guaiacyl lignin in angiosperm trees. Three full-length pox cDNAs px1, px2 and px3 were cloned from the developing xylem of Norway spruce. It was shown that px1 and px2 are expressed in developing tracheids in spruce seedlings, whereas px3 transcripts were not detected suggesting low transcription level in young trees. The amino acid sequences of PX1, PX2 and PX3 were less than 60% identical to each other but showed up to 84% identity to other known POXs. They all begin with predicted N-terminal secretion signal (SS) peptides. PX2 and PX3 contained additional putative vacuolar localization determinants (VSDs) at C-terminus. Transient expression of EGFP-fusions of the SS- and VSD-peptides in tobacco protoplasts showed SS-peptides directed EGFP to secretion in tobacco cells, whereas only the PX2 C-terminal peptide seems to be a functional VSD. According to heterologous expression of px1 in Catharanthus roseus hairy roots, PX1 is a guaicol-oxidizing POX with isoelectric point (pI) approximately 10, similar to monolignol oxidizing POXs in protein extracts from Norway spruce lignifying xylem. Hence, PX1 has characteristics for participation to monolignol dehydrogenation in lignin synthesis, whereas the other two spruce POXs seem to have some other functions. Interesting topics in future include functional characterization of syringyl compound oxidizing POXs and components of POX activity regulation in trees.

Phthalocyanine macrocycle as stabilizer for gold and silver nanoparticles

A one-step process was used for the preparation of gold and silver nanoparticles stabilized by an aminophthalocyanine macrocycle. The resultant nanoparticles were characterized by absorption spectra, infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The nanoparticles were found to possess relatively narrow size distribution. The gold nanoparticles have an average diameter of similar to 2 nm, while silver particles have 4-5 nm. Preliminary studies on fluorescence and surface enhanced Raman spectroscopy were carried out using these nanoparticles. Fluorescence studies indicate that gold nanoparticles do not quench the fluorescence, while silver nanoparticles do. The stabilized nanoparticles showed enhancement of the Raman signals, thus revealing that they are good substrates for surface enhanced Raman scattering studies.

Prey of the silver-headed antechinus (Antechinus argentus), a new species of Australian dasyurid marsupial

The silver-headed antechinus (Antechinus argentus) is one of Australia’s most recently described mammals, and the single known population at Kroombit Tops in south-east Queensland is threatened. Nothing is known of the species’ ecology, so during 2014 we collected faecal pellets each month (March–September) from a population at the type locality to gather baseline data on diet composition. A total of 38 faecal pellets were collected from 12 individuals (eight females, four males) and microscopic analysis of pellets identified seven invertebrate orders, with 70% combined mean composition of beetles (Coleoptera: 38%) and cockroaches (Blattodea: 32%). Other orders that featured as prey were ants, crickets/grasshoppers, butterflies/moths, spiders, and true bugs. Given that faecal pellets could only be collected from a single habitat type (Eucalyptus montivaga high-altitude open forest) and location, this is best described as a generalist insectivorous diet that is characteristic of other previously studied congeners.

Electrochemical properties and intermediate-temperature fuel cell performance of dense yttrium-doped barium zirconate with calcium addition

Although BaZr 0.8Y 0.2O 3-δ(BZY) possesses large bulk proton conductivity and excellent chemical stability, its poor sinterability and grain boundaries block proton conduction. In this work, the effect of Ca as a co-dopant and as a sintering aid (as CaO), on the sinterability, proton conductivity, and fuel cell performance of BZY was investigated. The addition of 4 mol% CaO significantly improved the BZY sinterability: BZY pellets with densities of 92.7% and 97.5% with respect to the theoretical density were obtained after sintering at 1500°C and 1600°C, respectively. The improved BZY sinterability by CaO addition resulted also in a large proton conductivity; at 600°C, the total conductivity of BZY-CaO was 2.14 × 10 -3 S/cm, in wet Ar. Anode-supported fuel cells with 25 μm-thick BZY-CaO electrolyte membranes were fabricated by a dual-layer co-firing technique. The peak power density of the fuel cell with a BZY-Ni/BZY-4CaO/BZY-LSCF (La 0.6Sr 0.4Fe 0.8Co 0.2O 3-δ) configuration was 141 mW/cm 2 at 700°C, several times larger than the reported values of BZY electrolyte membrane fuel cells sintered with the addition of CuO or ZnO, demonstrating promising features for practical fuel cell applications.

Effect of increased manganese addition and mould type on the slurry erosion characteristics of Cr-Mn iron systems

The wear resistance of high chromium iron is well recorded. However, the same is not the case as regards the use of manganese at higher percentages in high chromium irons and its influence on wear behaviour. Hence, this work highlights the slurry wear characteristics of chromium 16–19%) iron following the introduction of manganese at two levels i.e. 5 and 10%. It is known that the wear properties are dictated by the microstructural features. To alter the structure, the cooling rate of casting has been varied by adopting two different types of moulds (i.e. sand and metal) and subsequently subjecting to thermal treatment. The as-cast and heat treated samples are examined for microstructure and then evaluated for hardness and slurry erosion properties. As the manganese content is increased from 5 to 10%, the hardness showed a decrease in value both in the as-cast and heat treated conditions. The slurry erosion loss, expectedly, showed an increase irrespective of the sample condition (i.e. mould type/heat treatment adopted). The findings are corroborated with the microstructural features obtained through optical and scanning electron microscopy.

Effect of the addition of B2O3 and BaO-B2O3-SiO2 glasses on the microstructure and dielectric properties of giant dielectric constant material CaCu3Ti4O12

The effect of the addition of glassy phases on the microstructure and dielectric properties of CaCu3Ti4O12 (CCTO) ceramics was investigated. Both single-component (B2O3) and multi-cornponent (30wt% BaO-60wt% B2O3-10wt% SiO2 (BBS)) glass systems were chosen to study their effect on the density, microstructure and dielectric properties of CCTO. Addition of an optimum amount of B2O3 glass facilitated grain growth and an increase in dielectric constant. However, further increase in the B2O3 content resulted in its segregation at the grain boundaries associated with a reduction in the grain size. In contrast, BBS glass addition resulted in well-faceted grains and increase in the dielectric constant and decrease in the dielectric loss. An internal barrier layer capacitance (IBLC) model was invoked to correlate the dielectric constant with the grain size in these samples. (c) 2007 Elsevier Inc. All rights reserved.

Process variables in biomimetic synthesis of silver nanoparticles by aqueous extract of Azadirachta indica (Neem) leaves

Owing to widespread applications, synthesis and characterization of silver nanoparticles is recently attracting considerable attention. Increasing environmental concerns over chemical synthesis routes have resulted in attempts to develop biomimetic approaches. One of them is synthesis using plant parts, which eliminates the elaborate process of maintaining the microbial culture and often found to be kinetically favourable than other bioprocesses. The present study deals with investigating the effect of process variables like reductant concentrations, reaction pH, mixing ratio of the reactants and interaction time on the morphology and size of silver nanoparticles synthesized using aqueous extract of Azadirachta indica (Neem) leaves. The formation of crystalline silver nanoparticles was confirmed using X-ray diffraction analysis. By means of UV spectroscopy, Scanning and Transmission Electron Microscopy techniques, it was observed that the morphology and size of the nanoparticles were strongly dependent on the process parameters. Within 4 h interaction period, nanoparticles below 20-nm-size with nearly spherical shape were produced. On increasing interaction time (ageing) to 66 days, both aggregation and shape anisotropy (ellipsoidal, polyhedral and capsular) of the particles increased. In alkaline pH range, the stability of cluster distribution increased with a declined tendency for aggregation of the particles. It can be inferred from the study that fine tuning the bioprocess parameters will enhance possibilities of desired nano-product tailor made for particular applications.

Supramolecular Organization in Tetra Aqua (mu-8-Hydroxyquinoline-5-sulfonate) Barium (II) and Ag center dot center dot center dot I Interactions in a Pseudopolymorphic Form of (7-Iodo-8-hydroxyquinoline-5-sulfonate) Silver (I) Monohydrate

The complexes, Ba (HQS) (H2O)(4) (HQS = 8-hydroxyquinoline-5-sulfonic acid) (1) and Ag (HIQS) (H2O) (Ferron = 7-iodo-8-hydroxyquinoline-5-sulfonic acid) (2) have been synthesized and characterized by X-ray diffraction analysis and spectroscopic studies. In compound 1, Ba2+ ion has a nine-coordinate monocapped antiprismatic geometry. In compound 2, Ag+ has distorted tetrahedral coordination and Ag center dot center dot center dot I interactions generate the supramolecular architectures. The complexes have been characterized by FT-IR and UV-Visible measurements. In both the structures, the inversion-related organic ligands are stacked over one another leading to three-dimensional networks.

Stabilizing High-Energy Crystal Structure in Silver Nanowires with Underpotential Electrochemistry

We demonstrate that commonly face-centered cubic (fcc) metallic nanowires can be stabilized in hexagonal structures even when their surface energy contribution is relatively small. With a modified electrochemical growth process, we have grown purely single-crystalline 4H silver nanowires (AgNWs) of diameters as large as 100 nm within nanoporous anodic alumina and polycarbonate templates. The growth process is not limited by the/Ag Nernst equilibrium potential, and time-resolved imaging with high-resolution transmission electron microscopy (TEM) indicates a kinematically new mechanism of nanowire growth. Most importantly, our experiments aim to separate the effects of confinement and growth conditions on the crystal structure of nanoscale systems.

Safety of Repair, Maintenance, Minor Alteration, and Addition (RMAA) Works: A New Focus of Construction Safety

"Safety of RMAA works is an almost uncharted topic of rising importance internationally. Small construction contractors are particularly dependant on RMAA work, especially during times of recession, and they undertake more risks on these jobs than large companies do. This book is based on unique international research and consultancy projects which detail, investigate, and suggest solutions to the specific challenges of safety in RMAA works, based on case studies. Starting with an overview of safety in the wider construction industries of developed countries, the first half of this book also provides a comprehensive summary of relevant rules, regulations, and the resulting safety performances. The systems in the UK, US and Hong Kong are described and contrasted, giving the reader an understanding of how different regulatory approaches have yielded a variety of results. From this solid introduction, specific problems observed in RMAA work are examined through case studies, with reference to the underlying cultural and demographic factors, and a variety of practical engineering and management solutions are explored. This important and practical international work is essential reading for postgraduate students of health and safety in construction, construction project management, or construction in developing countries, as well as policy-makers and construction project managers."--Publisher website

Infrared absorption spectra of single crystals of glycine silver nitrate and monoglycine nitrate

he infrared absorption spectra of glycine silver nitrate (GAgNO3) and glycine nitrate (GHNO3) show that the glycine group exists completely in the zwitter ion form in the former and in both forms in the latter. The spectrum of GAgNO3 at liquid air temperature did not reveal any striking change which can be attributed to a freezing of the rapid reorientation of the NH3+ group taking place at higher temperatures. The position of the COO− stretching frequencies indicate that this group is co-ordinated only weakly to the Ag+ ion. The summation frequencies reported by Schroeder, Wier and Lippincott (1962) for AgNO3 were not observed in the present study on GAgNO3. It shows however that ferroelectricity in GAgNO3 is in all probability due to the motion of the Ag+ ion in the oxygen co-ordination polyhedron and is not directly connected with the ordering of the hydrogen bonds below Curie point.