Advances in solid polymer electrolyte fuel cell technology with low-platinum-loading electrodes

The Gemini Space program demonstrated the first major application of fuel cell systems. Solid polymer electrolyte fuel cells were used as auxiliary power sources in the spacecraft. There has been considerable progress in this technology since then, particularly with the substitution of Nafion for the polystyrene sulfonate membrane as the electrolyte. Until recently the performance was good only with high platinum loading (4 mg/sq cm) electrodes. Methods are presented to advance the technology by (1) use of low platinum loading (0.35 mg/sq cm) electrodes; (2) optimization of anode/membrane/cathode interfaces by hot pressing; (3) pressurization of reactant gases, which is most important when air is used as cathodic reactant; and (4) adequate humidification of reactant gases to overcome the water management problem. The high performance of the fuel cell with the low loading of platinum appears to be due to the extension of the three dimensional reaction zone by introduction of a proton conductor, Nafion. This was confirmed by cyclic voltammetry

Alloys for hydrogen storage in nickel/hydrogen and nickel/metal hydride batteries

Since 1990, there has been an ongoing collaboration among the authors in the three laboratories to (1) prepare alloys of the AB(sub 5) and AB(sub 2) types, using arc-melting/annealing and mechanical alloying/annealing techniques; (2) examine their physico-chemical characteristics (morphology, composition); (3) determine the hydrogen absorption/desorption behavior (pressure-composition isotherms as a function of temperature); and (4) evaluate their performance characteristics as hydride electrodes (charge/discharge, capacity retention, cycle life, high rate capability). The work carried out on representative AB(sub 5) and AB(sub 2) type modified alloys (by partial substitution or with small additives of other elements) is presented. The purpose of the modification was to optimize the thermodynamics and kinetics of the hydriding/dehydriding reactions and enhance the stabilities of the alloys for the desired battery applications. The results of our collaboration, to date, demonstrate that (1) alloys prepared by arc melting/annealing and mechanical alloying/annealing techniques exhibit similar morphology, composition and hydriding/dehydriding characteristics; (2) alloys with the appropriate small amounts of substituent or additive elements: (1) retain the single phase structure, (2) improve the hydriding/dehydriding reactions for the battery applications, and (3) enhance the stability in the battery environment; and (3) the AB(sub 2) type alloys exhibit higher energy densities than the AB(sub 5) type alloys but the state-of-the-art, commercialized batteries are predominantly manufactured using Ab(sub 5) type alloys

Using a population-based approach to prevent hepatocellular cancer in New South Wales, Australia: effects on health services utilisation

<p>Abstract</p> <p>Background</p> <p>Australians born in countries where hepatitis B infection is endemic are 6-12 times more likely to develop hepatocellular cancer (HCC) than Australian-born individuals. However, a program of screening, surveillance and treatment of chronic hepatitis B (CHB) in high risk populations could significantly reduce disease progression and death related to end-stage liver disease and HCC. Consequently we are implementing the <it>B Positive </it>pilot project, aiming to optimise the management of CHB in at-risk populations in south-west Sydney. Program participants receive routine care, enhanced disease surveillance or specialist referral, according to their stage of CHB infection, level of viral load and extent of liver injury. In this paper we examine the program's potential impact on health services utilisation in the study area.</p> <p>Methods</p> <p>Estimated numbers of CHB infections were derived from Australian Bureau of Statistics data and applying estimates of HBV prevalence rates from migrants' countries of birth. These figures were entered into a Markov model of disease progression, constructing a hypothetical cohort of Asian-born adults with CHB infection. We calculated the number of participants in different CHB disease states and estimated the numbers of GP and specialist consultations and liver ultrasound examinations the cohort would require annually over the life of the program.</p> <p>Results</p> <p>Assuming a 25% participation rate among the 5,800 local residents estimated to have chronic hepatitis B infection, approximately 750 people would require routine follow up, 260 enhanced disease surveillance and 210 specialist care during the first year after recruitment is completed. This translates into 5 additional appointments per year for each local GP, 25 for each specialist and 420 additional liver ultrasound examinations.</p> <p>Conclusions</p> <p>While the program will not greatly affect the volume of local GP consultations, it will lead to a significant increase in demand for specialist services. New models of CHB care may be required to aid program implementation and up scaling the program will need to factor in additional demands on health care utilisation in areas of high hepatitis B sero-prevalence.</p

RNA Sequencing of Lens Capsular Epithelium Implicates Novel Pathways in Pseudoexfoliation Syndrome

Published: March 29, 2022PURPOSE. Pseudoexfoliation syndrome (PEX) is a common systemic disease that results in severe and often irreversible vision loss. Despite considerable research effort, PEX remains incompletely understood. This study sought to perform the first RNAseq study in elucidate the pathophysiology of PEX, and contribute a publicly available transcriptomic data resource for future research. METHODS. Human ocular lens capsular epithelium samples were collected from 25 patients with PEX and 39 non-PEX controls undergoing cataract surgery. RNA extracted from these specimens was subjected to polyadenylated (mRNA) selection and deep bulk RNA sequencing. Differential expression analysis investigated protein-coding gene transcripts. Exploratory analyses used pathway analysis tools, and curated class- and disease-specific gene sets. RESULTS. Differential expression analysis demonstrated that 2882 genes were differentially expressed according to PEX status. Genes associated with viral gene expression pathways were among the most upregulated, alongside genes encoding ribosomal and mitochondrial respiratory transport chain proteins. Cell adhesion protein transcripts including type 4 collagen subunits were downregulated. CONCLUSIONS. This comparative transcriptomic dataset highlights novel and previously recognized pathogenic pathways in PEX and provides the first comprehensive transcriptomic resource, adding an additional layer to build further understanding of PEX pathophysiology.Sean Mullany, Henry Marshall, Tiger Zhou, Daniel Thomson, Joshua M. Schmidt, Ayub Qassim, Lachlan S. W. Knight, Georgina Hollitt, Ella C. Berry, Thi Nguyen, Minh-Son To, David Dimasi, Abraham Kuot, Joshua Dubowsky, Rhys Fogarty, Michelle Sun, Luke Chehade, Shilpa Kuruvilla, Devaraj Supramaniam, James Breen, Shiwani Sharma, John Landers, Stewart Lake, Richard A. Mills, Mark M. Hassall, Weng O. Chan, Sonja Klebe, Emmanuelle Souzeau, Owen M. Siggs, and Jamie E. Crai

Cancer screening among migrants in an Australian cohort; cross-sectional analyses from the 45 and Up Study

<p>Abstract</p> <p>Background</p> <p>Limited evidence suggests that people from non-English speaking backgrounds in Australia have lower than average rates of participation in cancer screening programs. The objective of this study was to examine the distribution of bowel, breast and prostate cancer test use by place of birth and years since migration in a large population-based cohort study in Australia.</p> <p>Methods</p> <p>In 2006, screening status, country of birth and other demographic and health related factors were ascertained by self-completed questionnaire among 31,401 (16,126 women and 15,275 men) participants aged 50 or over from the 45 and Up Study in New South Wales.</p> <p>Results</p> <p>35% of women and 39% of men reported having a bowel cancer test and 57% of men reported having a prostate specific antigen (PSA) test, in the previous 5 years. 72% of women reported having screening mammography in the previous 2 years. Compared to Australian-born women, women from East Asia, Southeast Asia, Continental Western Europe, and North Africa/Middle East had significantly lower rates of bowel testing, with odds ratios (OR; 95%CI) ranging from 0.5 (0.4–0.7) to 0.7 (0.6–0.9); migrants from East Asia (0.5, 0.3–0.7) and North Africa/Middle East (0.5, 0.3–0.9) had significantly lower rates of mammography. Compared to Australian-born men, bowel cancer testing was significantly lower among men from all regions of Asia (OR, 95%CI ranging from 0.4, 0.3–0.6 to 0.6, 0.5–0.9) and Continental Europe (OR, 95%CI ranging from 0.4, 0.3–0.7 to 0.7, 0.6–0.9). Only men from East Asia had significantly lower PSA testing rates than Australian-born men (0.4, 0.3–0.6). As the number of years lived in Australia increased, cancer test use among migrants approached Australian-born rates.</p> <p>Conclusion</p> <p>Certain migrant groups within the population may require targeted intervention to improve their uptake of cancer screening, particularly screening for bowel cancer.</p

Sustainable low-field cardiovascular magnetic resonance in changing healthcare systems.

Cardiovascular disease continues to be a major burden facing healthcare systems worldwide. In the developed world, cardiovascular magnetic resonance (CMR) is a well-established non-invasive imaging modality in the diagnosis of cardiovascular disease. However, there is significant global inequality in availability and access to CMR due to its high cost, technical demands as well as existing disparities in healthcare and technical infrastructures across high-income and low-income countries. Recent renewed interest in low-field CMR has been spurred by the clinical need to provide sustainable imaging technology capable of yielding diagnosticquality images whilst also being tailored to the local populations and healthcare ecosystems. This review aims to evaluate the technical, practical and cost considerations of low field CMR whilst also exploring the key barriers to implementing sustainable MRI in both the developing and developed world

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery

Australia's National Bowel Cancer Screening Program: does it work for Indigenous Australians?

<p>Abstract</p> <p>Background</p> <p>Despite a lower incidence of bowel cancer overall, Indigenous Australians are more likely to be diagnosed at an advanced stage when prognosis is poor. Bowel cancer screening is an effective means of reducing incidence and mortality from bowel cancer through early identification and prompt treatment. In 2006, Australia began rolling out a population-based National Bowel Cancer Screening Program (NBCSP) using the Faecal Occult Blood Test. Initial evaluation of the program revealed substantial disparities in bowel cancer screening uptake with Indigenous Australians significantly less likely to participate in screening than the non-Indigenous population.</p> <p>This paper critically reviews characteristics of the program which may contribute to the discrepancy in screening uptake, and includes an analysis of organisational, structural, and socio-cultural barriers that play a part in the poorer participation of Indigenous and other disadvantaged and minority groups.</p> <p>Methods</p> <p>A search was undertaken of peer-reviewed journal articles, government reports, and other grey literature using electronic databases and citation snowballing. Articles were critically evaluated for relevance to themes that addressed the research questions.</p> <p>Results</p> <p>The NBCSP is not reaching many Indigenous Australians in the target group, with factors contributing to sub-optimal participation including how participants are selected, the way the screening kit is distributed, the nature of the test and comprehensiveness of its contents, cultural perceptions of cancer and prevailing low levels of knowledge and awareness of bowel cancer and the importance of screening.</p> <p>Conclusions</p> <p>Our findings suggest that the population-based approach to implementing bowel cancer screening to the Australian population unintentionally excludes vulnerable minorities, particularly Indigenous and other culturally and linguistically diverse groups. This potentially contributes to exacerbating the already widening disparities in cancer outcomes that exist among Indigenous Australians. Modifications to the program are recommended to facilitate access and participation by Indigenous and other minority populations. Further research is also needed to understand the needs and social and cultural sensitivities of these groups around cancer screening and inform alternative approaches to bowel cancer screening.</p