An enhanced procedure for the rapid digestion of high silicate archeological specimens followed by ICP-MS determination of traces of rare earth elements (REE's)

A straightforward procedure for the acid digestion of geological samples with SiO2 concentrations ranging between about 40 to 80%, is described. A powdered sample (200 mesh) of 500 mg was used and fused with 1000 mg spectroflux at about 1000 degreesC in a platinum crucible. The molten was subsequently digested in an aqueous solution of HNO3 at 100 degreesC. Several systematic digestion procedures were followed using various concentrations of HNO3. It was found that a relationship could be established between the dissolution-time and acid concentration. For an acid concentration of 15% an optimum dissolution-time of under 4 min was recorded. To verify that the dissolutions were complete, they were subjected to rigorous quality control tests. The turbidity and viscosity were examined at different intervals and the results were compared with that of deionised water. No significant change in either parameter was observed. The shelf-life of each solution lasted for several months, after which time polymeric silicic acid formed in some solutions, resulting in the presence of a gelatinous solid. The method is cost effective and is clearly well suited for routine applications on a small scale, especially in laboratories in developing countries. ICP-MS was applied to the determination of 13 Rare Earth Elements and Hf in a set of 107 archaeological samples subjected to the above digestion procedure. The distribution of these elements was examined and the possibility of using the REE's for provenance studies is discussed.

Structure and palaeoenvironmental implications of inter-branch coenosteum-rich skeleton in corymbose Acropora species

Coral reefs provide an increasingly important archive of palaeoclimate data that can be used to constrain climate model simulations. Reconstructing past environmental conditions may also provide insights into the potential of reef systems to survive changes in the Earth’s climate. Reef-based palaeoclimate reconstructions are predominately derived from colonies of massive Porites, with the most abundant genus in the Indo-Pacific—Acropora—receiving little attention owing to their branching growth trajectories, high extension rates and secondary skeletal thickening. However, inter-branch skeleton (consisting of both coenosteum and corallites) near the bases of corymbose Acropora colonies holds significant potential as a climate archive. This region of Acropora skeleton is atypical, having simple growth trajectories with parallel corallites, approximately horizontal density banding, low apparent extension rates and a simple microstructure with limited secondary thickening. Hence, inter-branch skeleton in Acropora bears more similarities to the coralla of massive corals, such as Porites, than to traditional Acropora branches. Cyclic patterns of Sr/Ca ratios in this structure suggest that the observed density banding is annual in nature, thus opening up the potential to use abundant corymbose Acropora for palaeoclimate reconstruction.

Activation of the canonical Wnt signaling pathway induces cementum regeneration

Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost due to disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (i) local injection of lithium chloride; (ii) local injection of sclerostin antibody; and (iii) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs.

FGF-2 induces the proliferation of human periodontal ligament cells and modulates their osteoblastic phenotype by affecting Runx2 expression in the presence and absence of osteogenic inducers

The exact phenotype of human periodontal ligament cells (hPDLCs) remains a controversial area. Basic fibroblast growth factor (FGF‑2) exhibits various functions and its effect on hPDLCs is also controversial. Therefore, the present study examined the effect of FGF‑2 on the growth and osteoblastic phenotype of hPDLCs with or without osteogenic inducers (dexamethasone and β‑glycerophosphate). FGF‑2 was added to defined growth culture medium and osteogenic inductive culture medium. Cell proliferation, osteogenic differentiation and mineralization were measured. The selected differentiation markers, Runx2, collagen type Ⅰ, α1 (Col1a1), osteocalcin (OCN) and epidermal growth factor receptor (EGFR), were investigated by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). Runx2 and OCN protein expression was measured by western blotting. FGF‑2 significantly increased the proliferation of hPDLCs, but did not affect alkaline phosphatase activity. RT‑qPCR analysis revealed enhanced mRNA expression of Runx2, OCN and EGFR, but suppressed Col1a1 gene expression in the absence of osteogenic inducers, whereas all these gene levels had no clear trend in their presence. The Runx2 protein expression was clearly increased, but the OCN protein level showed no evident trend. The mineralization assay demonstrated that FGF‑2 inhibited mineralized matrix deposition with osteogenic inducers. These results suggested that FGF‑2 induces the growth of immature hPDLCs, which is a competitive inhibitor of epithelial downgrowth, and suppresses their differentiation into mineralized tissue by affecting Runx2 expression. Therefore, this may lead to the acceleration of periodontal regeneration.

Climate change, sustainability and science education

The world and its peoples are facing multiple, complex challenges and we cannot continue as we are (Moss, 2010). Earth‘s “natural capital” - nature‘s ability to provide essential ecosystem services to stabilize world climate systems, maintain water quality, support secure food production, supply energy needs, moderate environmental impacts, and ensure social harmony and equity – is seriously compromised (Gough, 2005; Hawkins, Lovins & Lovins, 1999). To further summarize, current rates of resource consumption by the global human population are unsustainable (Kitzes, Peller, Goldfinger & Wackernagel, 2007) for human and non-human species, and for future generations. Further, continuing growth in world population and global political commitment to growth economics compounds these demands. Despite growing recognition of the serious consequences for people and planet, little consideration is given, within most nations, to the social and environmental issues that economic growth brings. For example, Australia is recognised as one of the developed countries most vulnerable to the impacts of climate change. Yet, to date, responses (such as carbon pricing) have been small-scale, fragmented, and their worth disputed, even ridiculed. This is at a time referred to as ‘the critical decade’ (Hughes & McMichael, 2011) when the world’s peoples must make strong choices if we are to avert the worst impacts of climate change.

Bisphenol A sorption by organo-montmorillonite: Implications for the removal of organic contaminants from water

Remediation of bisphenol A (BPA) from aqueous solutions by adsorption using organoclays synthesized from montmorillonite (MMT) with different types of organic surfactant molecules was demonstrated. High adsorption capacities of the organoclays for the uptake of BPA were observed and these demonstrated their potential application as strong adsorbents for noxious organic water contaminants. The adsorption of BPA was significantly influenced by pH, with increased adsorption of BPA in acidic pH range. However, the organoclays intercalated with highly loaded surfactants and/or large surfactant molecules were less influenced by the pH of the environment and this was thought to be due to the shielding the negative charge from surfactant molecules and the development of more positive charge on the clay surface, which leads to the attraction of anionic BPA even at alkaline pH. The hydrophobic phase created by loaded surfactant molecules contributed to a partitioning phase, interacting with BPA molecules strongly through hydrophobic interaction. Pseudo-second order kinetic model and Langmuir isotherm provided the best fit for the adsorption of BPA onto the organoclays. In addition, the adsorption process was spontaneous and exothermic with lower temperature facilitating the adsorption of BPA onto the organoclays. The described process provides a potential pathway for the removal of BPA from contaminated waters.

Graphene-oxide-modified β-tricalcium phosphate bioceramics stimulate in vitro and in vivo osteogenesis

Graphene oxide (GO) has attracted much interest for applications in bone tissue engineering; however, until now the interaction between GO and stem cells, and the in vivo bone-forming ability of GO has not been explored. The aim of this study was to produce a GO-modified β-tricalcium phosphate (β-TCP-GRA) biceramics and then explore the material’s osteogenic capacity in vitro and in vivo, as well as unravel some of the molecular mechanisms behind this. β-TCP-GRA disks and scaffolds were successfully prepared by a simple GO/water suspension soaking method in combination with heat treatment. These scaffolds were found to significantly enhance the proliferation, alkaline phosphatase activity and osteogenic gene expression of human bone marrow stromal cells (hBMSCs), when compared to β-TCP without GO modification (controls). Activation of the Wnt/β-catenin signaling pathway in hBMSCs appears to be the mechanism behind this osteogenic induction by β-TCP-GRA. β-TCP-GRA scaffolds led to an increased rate of in vivo new bone formation compared to β-TCP controls, indicative of the stimulatory effect of GO on in vivo osteogenesis, making GO modification of β-TCP a very promising method for applications in bone tissue engineering, in particular for the regeneration of large bone defects.

Eruption centres of the Hamilton area of the Newer Volcanics Province, Victoria, Australia: Pinpointing volcanoes from a multifaceted approach to landform mapping

Volcanic eruption centres of the mostly 4.5 Ma-5000 BP Newer Volcanics Province in the Hamilton area of southeastern Australia were examined in detail using a multifaceted approach, including ground truthing and analysis of ArcGIS Total Magnetic Intensity and seamless geology data, NASA Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation models and Google Earth satellite image interpretation. Sixteen eruption centres were recognised in the Hamilton area, including three previously unrecorded volcanoes-one of which, the Cas Maar, constitutes the northernmost maar-cone volcanic complex in the Western Plains subprovince. Seven previously allocated eruption centres were placed into question based on field and laboratory observations. Three phases of volcanic activity have been suggested by other authors and are interpreted to correlate with ages of >4 Ma, ca 2 Ma and <0.5 Ma, which may be further subdivided based on preservation of outcrop. Geochemical compositions of the dominantly basaltic products become increasingly alkaline and enriched in incompatible elements from Phases 1 to 2, with Phase 3 eruptions both covering the entire geochemical range and extending into increasingly enriched compositions. This research highlights the importance of a multifaceted approach to landform mapping and demonstrates that additional volcanic centres may yet be discovered in the Newer Volcanics Province

Good for the environment good for health

“First do no harm”. This phrase, attributed to the 19th century surgeon, Thomas Inman, 1 reflects an equivalent phrase found in Epidemics, Book I of the Hippocratic School, “Practise two things in your dealings with disease: either help or do not harm the patient”. Pharmacists have played, and continue to play, an important role in reducing patient harm from medication misadventures. Now, they have a new role to play. The delivery of pharmaceutical care contributes to climate change (e.g. through the embedded carbon in the manufacture and distribution of medicines, disposal of waste, and energy and water use),2 which in turn has a negative impact on health. 3,4 This paradox argues a moral and ethical obligation by pharmacists, to deliver pharmaceutical care more sustainably – do no harm. Sustainability “…. is concerned, on one hand, with resources and how we can preserve them, and, on the other hand, with waste products and how we can best reduce or dispose of them.” 5(p.37) It is about preserving and nurturing Earth’s resources and systems for this generation and future generations to enjoy. Pharmacists play an important role in preventative health strategies such as smoking cessation, promotion of healthier lifestyles and vaccination/immunisation programmes and have the potential to also play a significant role in delivering pharmaceutical care more sustainably. Sustainable pharmaceutical care may be considered a virtuous cycle - what is good for the environment is also good for our health. 5 The good news for community pharmacy owners and managers is that implementing sustainability initiatives in the pharmacy can also have significant financial co-benefits.

A taste of best practice in engineering sustainable solutions

This paper asks the question to what scale and speed does society need to reduce its ecological footprint and improve resource productivity to prevent further overshoot and return within the ecological limits of the earth’s ecological life support systems? How fast do these changes need to be achieved? The paper shows that now a large range of studies find that engineering sustainable solutions need to be roughly an order or magnitude resource productivity improvement (sometimes called a Factor of 10, or a 90% reduction) by 2050 to achieve real and lasting ecological sustainability. This marks a significant challenge for engineers – indeed all designers and architects, where best practice in engineering sustainable solutions will need to achieve large resource productivity targets. The paper brings together examples of best practice in achieving these large targets from around the world. The paper also highlights key resources and texts for engineers who wish to learn how to do it. But engineers need to be realistic and patient. Significant barriers exist to achieving Factor 4-10 such as the fact that infrastructure and technology rollover and replacement is often slow. This slow rollover of the built environment and technology is the context within which most engineers work, making the goal of achieving Factor 10 all the more challenging. However, the paper demonstrates that by using best practice in engineering sustainable solutions and by addressing the necessary market, information and institutional failures it is possible to achieve Factor 10 over the next 50 years. This paper draws on recent publications by The Natural Edge Project (TNEP) and partners, including Hargroves, K. Smith, M. (Eds) (2005) The Natural Advantage of Nations: Business Opportunities, Innovation and Governance for the 21st Century, and the TNEP Engineering Sustainable Solutions Program - Critical Literacies for Engineers Portfolio. Both projects have the significant support of Engineers Australia. its College of Environmental Engineers and the Society of Sustainability and Environmental Engineering.

Generation of catalytically active materials from a liquid metal precursor

A facile route to prepare catalystically active materials from a galinstan liquid metal alloy is introduced. Sonicating liquid galinstan in alkaline solution or treating it in reducing media results in the creation of solid In/Sn rich microspheres that show catalytic activity toward both potassium ferricyanide and 4-nitrophenol reduction.

Electrochemical restructuring of copper surfaces using organic additives and its effect on the electrocatalytic reduction of nitrate ions

This work describes the fabrication of nanostructured copper electrodes using a simple potential cycling protocol that involves oxidation and reduction of the surface in an alkaline solution. It was found that the inclusion of additives, such as benzyl alcohol and phenylacetic acid, has a profound effect on the surface oxidation process and the subsequent reduction of these oxides. This results in not only a morphology change, but also affects the electrocatalytic performance of the electrode for the reduction of nitrate ions. In all cases, the electrocatalytic performance of the restructured electrodes was significantly enhanced compared with the unmodified electrode. The most promising material was formed when phenylacetic acid was used as the additive. In addition, the reduction of residual oxides on the surface after the modification procedure to expose freshly active reaction sites on the surface before nitrate reduction was found to be a significant factor in dictating the overall electrocatalytic activity. It is envisaged that this approach offers an interesting way to fabricate other nanostructured electrode surfaces.

Solution chemistry impacts on the seawater neutralisation process: Benefits of nanofiltered seawater and reverse osmosis brine

It is well known that the neutralisation of Bayer liquor with seawater causes the precipitation of stable alkaline products and a reduction in pH and dissolved metal concentrations in the effluent. However, there is limited information available on solution chemistry effects on the stability and reaction kinetics of these precipitates. This investigation shows the influence of reactive species (magnesium and calcium) in seawater on precipitate stabilities and volumetric efficiencies during the neutralisation of bauxite refinery residues. Correlations between synthetic seawater solutions and real samples of seawater (filtered seawater, nanofiltered seawater and reverse osmosis brine) have been made. These investigations have been used to confirm that alternative seawater sources can be used to increase the productivity potential of the neutralisation process with minimal implications on the composition and stability of precipitates formed. The volume efficiency of the neutralisation process using synthetic analogues has been shown to be almost directly proportional with the concentration of magnesium. This was further confirmed in the nanofiltered seawater and reverse osmosis brine that showed increases in the efficiency of neutralisation by factors of 3 and 2 compared to seawater, which corresponds with relatively the same increase in the concentration of magnesium in these alternative seawater sources. An assessment of the chemical stability of the precipitates, volumetric efficiency, and discharge water quality have been determined using numerous techniques that include pH, conductivity, inductively coupled plasma optical emission spectroscopy, infrared spectroscopy, thermogravimetric analysis coupled to mass spectrometry and X-ray diffraction. Correlations between synthetic solution compositions and alternative seawater sources have been used to determine if alternative seawater sources are potential substitutes for seawater based on improvements in productivity, implementation costs, savings to operations and environmental benefits.

Nanosheets Co3O4 interleaved with graphene for highly efficient oxygen reduction

Efficient yet inexpensive electrocatalysts for oxygen reduction reaction (ORR) are an essential component of renewable energy devices, such as fuel cells and metal-air batteries. We herein interleaved novel Co3O4 nanosheets with graphene to develop a first ever sheet-on-sheet heterostructured electrocatalyst for ORR, whose electrocatalytic activity outperformed the state-of-the-art commercial Pt/C with exceptional durability in alkaline solution. The composite demonstrates the highest activity of all the nonprecious metal electrocatalysts, such as those derived from Co3O4 nanoparticle/nitrogen-doped graphene hybrids and carbon nanotube/nanoparticle composites. Density functional theory (DFT) calculations indicated that the outstanding performance originated from the significant charge transfer from graphene to Co3O4 nanosheets promoting the electron transport through the whole structure. Theoretical calculations revealed that the enhanced stability can be ascribed to the strong interaction generated between both types of sheets.

A mouse with an N-ethyl-N-nitrosourea (ENU) induced Trp589Arg Galnt3 mutation represents a model for hyperphosphataemic familial tumoural calcinosis

Mutations of UDP-N-acetyl-alpha-D-galactosamine polypeptide N-acetyl galactosaminyl transferase 3 (GALNT3) result in familial tumoural calcinosis (FTC) and the hyperostosis-hyperphosphataemia syndrome (HHS), which are autosomal recessive disorders characterised by soft-tissue calcification and hyperphosphataemia. To facilitate in vivo studies of these heritable disorders of phosphate homeostasis, we embarked on establishing a mouse model by assessing progeny of mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU), and identified a mutant mouse, TCAL, with autosomal recessive inheritance of ectopic calcification, which involved multiple tissues, and hyperphosphataemia; the phenotype was designated TCAL and the locus, Tcal. TCAL males were infertile with loss of Sertoli cells and spermatozoa, and increased testicular apoptosis. Genetic mapping localized Tcal to chromosome 2 (62.64-71.11 Mb) which contained the Galnt3. DNA sequence analysis identified a Galnt3 missense mutation (Trp589Arg) in TCAL mice. Transient transfection of wild-type and mutant Galnt3-enhanced green fluorescent protein (EGFP) constructs in COS-7 cells revealed endoplasmic reticulum retention of the Trp589Arg mutant and Western blot analysis of kidney homogenates demonstrated defective glycosylation of Galnt3 in Tcal/Tcal mice. Tcal/Tcal mice had normal plasma calcium and parathyroid hormone concentrations; decreased alkaline phosphatase activity and intact Fgf23 concentrations; and elevation of circulating 1,25-dihydroxyvitamin D. Quantitative reverse transcriptase-PCR (qRT-PCR) revealed that Tcal/Tcal mice had increased expression of Galnt3 and Fgf23 in bone, but that renal expression of Klotho, 25-hydroxyvitamin D-1α-hydroxylase (Cyp27b1), and the sodium-phosphate co-transporters type-IIa and -IIc was similar to that in wild-type mice. Thus, TCAL mice have the phenotypic features of FTC and HHS, and provide a model for these disorders of phosphate metabolism. © 2012 Esapa et al.