Inactivation of the antibacterial and cytotoxic properties of silver ions by biologically relevant compounds

There has been a recent surge in the use of silver as an antimicrobial agent in a wide range of domestic and clinical products, intended to prevent or treat bacterial infections and reduce bacterial colonization of surfaces. It has been reported that the antibacterial and cytotoxic properties of silver are affected by the assay conditions, particularly the type of growth media used in vitro. The toxicity of Ag+ to bacterial cells is comparable to that of human cells. We demonstrate that biologically relevant compounds such as glutathione, cysteine and human blood components significantly reduce the toxicity of silver ions to clinically relevant pathogenic bacteria and primary human dermal fibroblasts (skin cells). Bacteria are able to grow normally in the presence of silver nitrate at >20-fold the minimum inhibitory concentration (MIC) if Ag+ and thiols are added in a 1:1 ratio because the reaction of Ag+ with extracellular thiols prevents silver ions from interacting with cells. Extracellular thiols and human serum also significantly reduce the antimicrobial activity of silver wound dressings Aquacel-Ag (Convatec) and Acticoat (Smith & Nephew) to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in vitro. These results have important implications for the deployment of silver as an antimicrobial agent in environments exposed to biological tissue or secretions. Significant amounts of money and effort have been directed at the development of silver-coated medical devices (e.g. dressings, catheters, implants). We believe our findings are essential for the effective design and testing of antimicrobial silver coatings

Stranded assets and the shipping industry

According to IMO forecasts, CO2 emissions from world shipping could double by the year 2050. Although shipping is in most cases the most efficient mode of transport per unit of transport supply, it is still heavily reliant on heavy fuel oil to power its propulsion. The IMO has introduced regulations to bring about reductions in the emissions of ships, including an Energy Efficiency Design Index which sets a mandatory CO2 intensity reduction target for new ships and imposing a sulphur regulation on ships operating in certain sea areas. At the same time, charterers are beginning to factor energy efficiency into their commercial decision-making through use of the EVDI (an approximation of EEDI). Exemplifying this trend, Cargill, Huntsman and UNIPEC UK publically announced in October 2012 that they would no longer charter the least efficient ships in the fleet. This regulatory environment, along with the uncertainty in energy prices and increased awareness of the industry’s carbon footprint, poses a threat to existing ships’ profitability and may result in certain ships becoming stranded assets. The objective of this paper is to identify the supply and demand-side risk factors contributing to existing ships becoming stranded assets, and to frame how an assessment could be carried out on the risk of stranded assets in the shipping industry

Colour stability and water-holding capacity of M. longissimus and carcass characteristics in fallow deer (Dama dama) grazed on natural pasture or fed barley

The effects of feeding regimen on carcass characteristics, meat colour and water-holding capacity of M. longissimus were studied in 24 female fallow deer (Dama dama). All animals were farm raised; twelve were grazed on pasture and twelve were fed barley and a small amount of hay prior to slaughter. The animals were slaughtered at two occasions (during the Southern Hemisphere spring); after 19 weeks of feeding (n=12; 6 grazing and 6 barley fed animals; group 1) and after 24 weeks of feeding (n=12; 6 grazing and 6 barley fed animals; group 2). The barley/hay-fed deer had significantly higher body condition scores and carcass weights than the pasture raised group. No difference in meat ultimate pH values between the treatment groups was recorded. The meat from the pasture raised deer had significantly longer colour display life after 2 and 3 weeks of refrigerated storage (+ 2.0 ºC) in vacuum bags. There was no difference in drip loss between the two treatment groups. However, significantly lower drip losses were found in meat from the animals in group 2 compared with the ones in group 1 (P ≤ 0.001). It was concluded that the feeding regimen of the animals is an important factor that contributes to the variation in quality of fresh chilled deer meat (venison), mainly the colour stability and display life of vacuum packaged meat.Abstract in Swedish / Sammanfattning: I denna undersökning ingick 24 dovhjortshindar (Dama dama) för att studera effekterna av olika typer av foder (bete och korn) på slaktkroppskvalitet samt färg och vattenhållande förmåga i köttet (M. longissimus). Alla djur var uppfödda på en hjortfarm, 12 betade gräs och 12 utfodrades med korn och en liten mängd hö före slakt. Djuren slaktades vid två olika tillfällen (under våren på det södra halvklotet); efter 19 veckors utfodring (n=12; 6 betesdjur och 6 kornfodrade djur; grupp 1) och efter 24 veckors utfodring (n=12; 6 betesdjur och 6 kornfodrade djur; grupp 2). De dovhjortar som utfodrats med korn och hö var i bättre kondition och hade högre slaktvikter jämfört med de djur som betat gräs. Ingen skillnad i köttets pH-värde mellan de två utfodringsgrupperna kunde dock påvisas. Köttet från de betande dovhjortarna hade bättre färgstabilitet efter lagring i 2 och 3 veckor (+ 2.0 ºC) i vakuumförpackning. Det fanns ingen skillnad mellan kött från betande och korn/hö-utfodrade djur i vattenhållande förmåga. Däremot hade kött från djur i grupp 2 (slaktade efter 24 veckors utfodring) bättre vattenhållande förmåga jämfört med grupp 1 (P ≤ 0.001). Vi kunde konstatera att de olika fodertyperna påverkade kvaliteten hos färskt kyllagrat kött, framförallt färgstabiliteten hos vakuumförpackat kött

De novo SCN1A mutations in Dravet syndrome and related epileptic encephalopathies are largely of paternal origin

Background: Dravet syndrome is a severe infantile epileptic encephalopathy caused in approximately 80% of cases by mutations in the voltage gated sodium channel subunit gene SCN1A. The majority of these mutations are de novo. The parental origin of de novo mutations varies widely among genetic disorders and the aim of this study was to determine this for Dravet syndrome. Methods: 91 patients with de novo SCN1A mutations and their parents were genotyped for single nucleotide polymorphisms (SNPs) in the region surrounding their mutation. Allele specific polymerase chain reaction (PCR) based on informative SNPs was used to separately amplify and sequence the paternal and maternal alleles to determine in which parental chromosome the mutation arose. Results: The parental origin of SCN1A mutations was established in 44 patients for whom both parents were available and SNPs were informative. The mutations were of paternal origin in 33 cases and of maternal origin in the remaining 11 cases. De novo mutation of SCN1A most commonly, but not exclusively, originates from the paternal chromosome. The average age of parents originating mutations did not differ from that of the general population. Conclusions: The greater frequency of paternally derived mutations in SCN1A is likely to be due to the greater chance of mutational events during the increased number of mitoses which occur during spermatogenesis compared to oogenesis, and the greater susceptibility to mutagenesis of the methylated DNA characteristic of sperm cells.Sarah E. Heron, Ingrid E. Scheffer, Xenia Iona, Sameer M. Zuberi, Rachael Birch, Jacinta M. McMahon, Carla M. Bruce, Samuel F. Berkovic, John C. Mulle

Non-stoichiometric oxide and metal interfaces and reactions

We have employed a combination of experimental surface science techniques and density functional calculations to study the reduction of TiO2(110) surfaces through the doping with submonolayer transition metals. We concentrate on the role of Ti adatoms in self doping of rutile and contrast the behaviour to that of Cr. DFT+U calculations enable identification of probable adsorption structures and their spectroscopic characteristics. Adsorption of both metals leads to a broken symmetry and an asymmetric charge transfer localised around the defect site of a mixed localised/delocalised character. Charge transfer creates defect states with Ti 3d character in the band gap at similar to 1-eV binding energy. Cr adsorption, however, leads to a very large shift in the valence-band edge to higher binding energy and the creation of Cr 3d states at 2.8-eV binding energy. Low-temperature oxidation lifts the Ti-derived band-gap states and modifies the intensity of the Cr features, indicative of a change of oxidation state from Cr3+ to Cr4+. Higher temperature processing leads to a loss of Cr from the surface region, indicative of its substitution into the bulk

The role of the chemical composition of monetite on the synthesis and properties of α-tricalcium phosphate

Peer reviewedPublisher PD

Learning through exchange about organic agriculture - case of Europe and Australia

LEAFSE is the catch word for an innovative program of exchange study for young Australians and Europeans, with organic agriculture as the focal point of their Masters level studies. Two years ago, the European Commission and the Australian Department of Education, Science and Technology (DEST) came up with the call for applications for a pilot project to support international mobility of tertiary students between the two continents. The grand aims set for the exchange included providing students with an international outlook and a range of perspectives, preparing them for the global marketplace, enable their understanding and empathy for different cultures and traditions and foster exchange of information. A number of us with an interest and an already existing academic network in organic agriculture proposed LEAFSE - Learning through Exchange - Agriculture, Food Systems and Environment, a winning project, which was chosen as the single pilot project from a field of well over a dozen contenders. Within the broader theme of Agriculture, Food Systems and Environment, we named organic farming as the focal point of the exchange, and we were aware of the immense possibilities for learning through exchange inter-continentally in this field. Under this project, Master's level students from EU study for a semester at a partner university in Australia, and students from Australia study for a semester at a partner university in EU. The partners in the programme are, from Europe: • The Royal Veterinary and Agricultural University, Denmark • University of Wales, Aberystwyth, United Kingdom • Wageningen University and Research Centre, The Netherlands • University of Kassel, Witzenhausen, Germany, and from Australia: • University of Western Sydney, New South Wales • University of New England, New South Wales • University of Western Australia, Western Australia • University of Queensland, Queensland The project has an innovative but manageable framework for mobility of the students, a joint programme of study which incorporates many novel elements including holistic thinking, experiential and integrated learning and use of newer tools of communication technologies, and above all, a structure that fosters a high degree of inter-cultural understanding and network building. When completed, the pilot phase of the project would have enabled exchange of 36 students from each continent, nine from each participating institution. The respective government agencies provide the students with an adequate stipend to cover travel and living expenses for six months of study. The project has been running on target and the results of the first year of exchange have been more than impressive. This presentation will be a joint effort by the faculty and a number of participating students to demonstrate the cultural, agricultural, pedagogic, and practical lessons that have been learnt from this exchange in the field of organic farming. It will also highlight some of the challenges which need to be overcome in our efforts towards shaping sustainable agricultural and food systems which are cognizant of our respective environments

The ethics of uncertainty for data subjects

Modern health data practices come with many practical uncertainties. In this paper, I argue that data subjects’ trust in the institutions and organizations that control their data, and their ability to know their own moral obligations in relation to their data, are undermined by significant uncertainties regarding the what, how, and who of mass data collection and analysis. I conclude by considering how proposals for managing situations of high uncertainty might be applied to this problem. These emphasize increasing organizational flexibility, knowledge, and capacity, and reducing hazard

Donor Characteristics of Pancreas Transplantation in Australia and New Zealand: A Cohort Study 1984-2014

Background The aim of this study was to audit the characteristics of pancreas donors over time in Australia and New Zealand. Pancreas transplantation was introduced in Australian and New Zealand in 1984. Methods We analyzed data from the Australia and New Zealand Islet and Pancreas Transplant Registry, 1984 to 2014. We investigated the variation of donor characteristics of sex, age, body mass index, smoking status, blood group, multiple organ donation, cytomegalovirus status, terminal creatinine, hypertension, and cause of death for pancreas transplantation over time. We used χ2 test (Fisher test when necessary) or analysis of variance to test difference for categorical or continuous characteristics, respectively. Results There were 628 pancreas donors from 1984 to 2014. Donor body mass index (from 21.9 to 24.0, P < 0.001) and age (from 23.9 to 28.5, P = 0.02) have both increased while terminal creatinine has decreased (86.3 to 73.3, P = 0.01) from 1995 to 2014. In the meantime, the proportions of donors with hypertension (from 19% to 1%, P < 0.001) and who were smokers (from 54% to 15%, P < 0.001) have decreased. Profile of cause of donor death has also changed over time (P = 0.06) with increase in cerebral hypoxia/ischemia (from 3% to 17%) and reductions in intracranial hemorrhage (27% to 13%). Conclusions Many donor characteristics have changed over time. The most significant changes appear to reflect changes in the general population, rather than changes in donor selection

Australia and New Zealand Islets and Pancreas Transplant Registry Annual Report 2018—Pancreas Waiting List, Recipients, and Donors

Background This is a synopsis of the registry report from the Australia and New Zealand islet and pancreas transplant registry. The full report is available at http://anziptr.org/reports/. Methods We report data for all solid organ pancreas transplant activity from inception in 1984 to end 2017. Islet-cell transplantation activity is reported elsewhere. Data analysis was performed using Stata software version 14 (StataCorp, College Station, TX). Results From 1984 to 2017 a total of 809 solid organ pancreas transplants have been performed in Australia and New Zealand, in 790 individuals. In 2017, 52 people received a pancreas transplant. By center, this was; Auckland (4), Monash (17), and Westmead (31). In 2017, 51 transplants were simultaneous pancreas kidney, whereas 1 was pancreas after kidney, and none were pancreas transplant alone. Conclusions The number of pancreas transplants performed in Australia and New Zealand was slightly lower in 2017 but continues to increase over time