M. Leigh Ackland’s research while affiliated with Deakin University and other places

As a result of the carbon-intensive nature of health care, hospital facilities are contributors to global warming. Health care’s contributions to global warming and greenhouse gas emissions include those associated with carbon emissions, energy consumption, pharmaceuticals, travel-related emissions and procurement. This article presents a review of environmental impact of different medical services. The published research articles focused on estimating the carbon footprint of healthcare services are investigated here. This review also discusses methods used for determining greenhouse gas emissions. Life cycle assessment and component analysis are the two most used methods for calculating emissions. This study also highlights the existing challenges related to estimation of carbon emission of different healthcare services and ways to overcome these challenges associated with carbon emission. The findings reveal substantial variability in carbon footprint estimates depending on region, settings, and usage patterns, with energy consumption identified as the primary source of greenhouse gas emissions. The review also addresses challenges in data availability, the accuracy of estimations, and the exclusion of critical factors like the environmental impact of medical equipment manufacturing. To mitigate healthcare’s carbon footprint, the study underscores the importance of transitioning from fossil fuels to renewable energy, minimizing unnecessary medical procedures, and promoting the use of reusable instruments. These insights are essential for developing more accurate and comprehensive strategies to reduce the carbon footprint of healthcare services globally.

Microorganisms do not live as dispersed single cells but rather they form aggregates with extracellular polymeric substances at interfaces. Biofilms are considered efficient life forms because they shield bacteria from biocides and collect dilute nutrients. This is a big concern in industry since the microorganisms can colonize a wide range of surfaces, accelerating material deterioration, colonizing medical devices, contaminating ultrapure drinking water, increasing energy costs and creating focus of infection. Conventional biocides that target a specific component of the bacteria are not effective in the presence of biofilms. Efficient biofilm inhibitors are based on a multitarget approach interacting with the bacteria and the biofilm matrix. Their rationale design requires a thorough understanding of inhibitory mechanisms that are still largely lacking today. Herein we uncover via molecular modelling the inhibition mechanism of cetrimonium 4-OH cinnamate (CTA-4OHcinn). Simulations show that CTA-4OH micelles can disrupt symmetric and asymmetric bilayers, representative of inner and outer bacterial membranes, following three stages: adsorption, assimilation, and defect formation. The main driving force for micellar attack is electrostatic interactions. In addition to disrupting the bilayers, the micelles work as carriers facilitating the trapping of 4OH cinnamate anions within the bilayer upper leaflet and overcoming electrostatic repulsion. The micelles also interact with extracellular DNA (e-DNA), which is one of the main components of biofilms. It is observed that CTA-4OHcinn forms spherical micelles on the DNA backbone; which hinders their ability to pack. This is demonstrated by modelling the DNA along the hbb histone-like protein, showing that in the presence of CTA-4OHcinn, DNA does not pack properly around hbb. The abilities of CTA-4OHcinn to cause cell death through membrane disruption and to disperse a mature, multi-species biofilm are also confirmed experimentally.

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms occurring predominantly in the gastrointestinal tract and pancreas. Their heterogeneity poses challenges for diagnosis and treatment. There is a paucity of markers for characterisation of NEN tumours. For routine diagnosis, immunohistochemistry of the NEN-specific markers CgA and synaptophysin and the proliferation marker Ki-67 are used. These parameters, however, are qualitative and lack the capacity to fully define the tumour phenotype. Molecules of epithelial–mesenchymal transition (EMT) are potential candidates for improved tumour characterisation. Using qRT-PCR, we measured mRNA levels of 27 tumour markers, including 25 EMT-associated markers, in tumour tissue and matched non-tumour tissues for 13 patients with pancreatic NENs. Tissue from patients with three different grades of tumour had distinctly different mRNA profiles. Of the 25 EMT-associated markers analysed, 17 were higher in G3 tissue relative to matched non-tumour tissue, including CD14, CD24, CD31, CD44, CD45, CD56, CK6, CK7, CK13, CK20, NSE, CDX2, CgA, DAXX, PCNA, laminin and Ki-67. The differences in levels of seven EMT-associated markers, Ki-67, DAXX, CD24, CD44, vimentin, laminin and PDX1 plus CgA and NSE (neuroendocrine markers) enabled a distinct molecular signature for each tumour grade to be generated. EMT molecules differentially expressed in three tumour grades have potential for use in tumour stratification and prognostication and as therapeutic targets for treatment of neuroendocrine cancers, following validation with additional samples.

Background: Carotenoids and chlorophylls are important pigments as they have antioxidant properties and some such as lutein, astaxanthin and β-carotene are used as nutraceuticals. Pigment profiles are also used as taxonomic markers for phytoplankton. There are many solvent compositions published for the extraction of phytoplankton pigments. Here we report the testing of five different commonly used solvents and compare the overall pigment and lipid profiles and abundances using liquid chromatography-mass spectrometry (LC-MS) for three microalgal species with different pigment profiles. Results: A fast and sensitive LC-MS method was developed using a C18 column with a gradient consisting of isopropanol, acetonitrile and water. A total of 18 pigments along with phosphatidylcholines (PCs), triacylglycerols (TAGs) were separated in 25 mins. An extraction solvent composition of 90% acetone provided the broadest-coverage of pigments and lipids, while ethanol/hexane resulted in the highest extraction efficiency for chlorophyll and the non-polar triacylglycerol lipids. Overall, the result for the different mixtures shows the significant impact that solvent polarity has on the overall pigment and lipid profile and that no single mixture was optimal for all targets. Complete cell lysis using mechanical disruption such as bead beating is also an important step for quantitative extraction as chemical extraction on its own does not provide reproducible results. Conclusion: A 90% acetone extraction solvent mixture provides the broadest extraction of pigments from the species Haematococcus pluvialis, Desmodesmus subspicatus and Chlorella variabilis when coupled with bead beating. This extraction solvent is comparatively safe, polar and less toxic than other solvents. It was also found that none of the common solvent mixtures tested here provided the highest extraction efficiencies across all compound groups

Microalgae are important renewable feedstock to produce biodiesel and high‐value chemicals. Different wavelengths of light influence the growth and metabolic activities of algae. Recent research has identified the light‐sensing proteins called photoreceptors that respond to blue or red light. Structural elucidations of algal photoreceptors have gained momentum over recent years. These include channelrhodopsins, PHOT proteins, animal‐like cryptochromes, and blue‐light sensors utilizing flavin‐adenine dinucleotide proteins. Pulsing light has also been investigated as a means to optimize energy inputs into bioreactors. This study summarizes the current structural and functional basis of photoreceptor modulation to optimize the growth, production of carotenoids and other high‐value metabolites from microalgae. The review also encompasses novel photobioreactor designs that implement different light regimes including light wavelengths and time to optimize algal growth and desired metabolite profiles for high‐value products.

Here, we describe the genome of Lelliottia sp. strain WAP21, which was isolated from the soil of canola fields in Australia. The genome has a size of 4.9 Mbp and 4,583 predicted genes, with some potential pathways for metabolism of various carbon sources and metal acquisition.

High strength steel in marine environments suffers from severe corrosion susceptibility and the presence of bacteria can exacerbate the effect, accelerating degradation via microbiologically influenced corrosion (MIC). Here we propose a novel approach to MIC inhibition by designing a system capable of limiting the effects of both bacterial growth and corrosion. The combination of a newly synthesised compound, cetrimonium 4-hydroxycinnamate (Cet-4OHCin), with lanthanum 4-hydroxycinnamate was the only system tested to date that could both inhibit abiotic corrosion in artificial seawater and minimise bacteria consortium densities over an exposure period of 24 h. This success was proposed to be due to them having the same anion, making them stable when mixed in the solution of the test environment. Furthermore, we confirmed from cytotoxicity testing that Cet-4OHCin demonstrated similarly limited toxicity towards human cells as the commercially available cetrimonium bromide, a known safe additive to cosmetic products. This new system shows promise as a safe and effective multifunctional inhibitor mixture to reduce the effects of MIC.

Hypothesis Molecular interactions between 4-OH-cinnamate and cetrimonium in solution result in improved adsorption of the cinnamate on mild steel, developing a protective mechanism against the diffusion of corrosive chloride to the oxide surface. Fundamental understanding of this mechanism should allow new design routes for the development of eco-friendly corrosion inhibitors. Experiments Via classic molecular dynamics, simulations were carried out for cetrimonium and 4-OH-cinnamate in aqueous solutions at different ionic strengths and the results were validated with experimental SAXS data. Self-aggregation of cetrimonium 4-OH-cinnamate on a hydrated hematite surface was then simulated and results were compared with cryo-TEM imaging for the same compound. Finally, the effect of the adsorbed aggregates on chloride diffusion to the oxide surface was modelled. Findings Simulations showed the encapsulation of 4-OH-cinnamate into cetrimonium micelles, consistent with experiments. The newly formed micelles adsorb onto a hydrated iron oxide surface by forming hydrogen bonds between their carboxylate outer-shell groups and the surface hydroxyls. As the adsorbate concentrations increase, there is a morphological transition from spherical to wormlike adsorbed aggregates. The wormlike structure can block chloride ions, demonstrating a synergistic inhibitory mechanism between both cetrimonium and 4-OH-cinnamate. Encapsulation and delivery of active compounds to certain targets, such as carcinogenic tumors, have been well studied in biochemistry research, we demonstrate that the same mechanism can be applied to the design of efficient corrosion inhibitors, optimizing their delivery to the metal surface.

Background Neuroendocrine neoplasms (NENs) are a complex group of tumours that occur in many organs. Routinely used IHC markers for NEN diagnosis include CgA, synaptophysin, Ki67 and CD56. These have limitations including lack of correlation to clinical outcomes and their presence in non-tumour tissue. Identification of additional markers and more quantitative analyses of tumour tissue has the potential to contribute to improved clinical outcomes. We used qRT-PCR to profile the expression levels of a panel of markers in tumour and matched non-tumour tissue from a patient with a G1 pancreatic neuroendocrine tumour. Differences in mRNA levels between tumour and non-tumour tissue were compared with IHC analyses of the same sample. Case presentation An elderly man presented with lower abdominal pain for 6 months. Histological analysis identified a low grade, well differentiated pancreatic endocrine neoplasm. Twenty-seven tumour markers for neuroendocrine status, proliferation, stem cell phenotype, angiogenesis, epithelial to mesenchymal transition, cell adhesion, differentiation and tumour suppression were selected from previous studies and mRNA levels of these markers were measured in tumour and adjacent non-tumour tissue sample using qRT-PCR. IHC was carried out on the same tissue to detect the corresponding marker proteins. Of the markers analysed, seven showed higher mRNA levels in tumour relative to non-tumour tissue while thirteen had lower expression in tumour relative to non-tumour tissue. Substantial differences in mRNA levels were a gain of CgA, CD56, β-catenin, CK20, PDX1 and p53 and loss of Ki67, PCAD, CK7, CD31, MENA, ECAD, EPCAM, CDX2 and CK6. Comparison of qRT-PCR data with IHC showed correlation between fifteen markers. Conclusion Our study is unique as it included matched controls that provided a comparative assessment for tumour tissue analysis, whereas many previous studies report tumour data only. Additionally, we utilised qRT-PCR, a relatively quantitative diagnostic tool for differential marker profiling, having the advantage of being reproducible, fast, cheap and accurate. qRT-PCR has the potential to improve the defining of tumour phenotypes and, in combination with IHC may have clinical utility towards improving tumour stratification or distinguishing tumour grades. The results need to be validated with different grades of NENs and related to clinical outcomes.

High strength steel in marine environments suffers from severe corrosion susceptibility and the presence of bacteria can exacerbate the effect, accelerating degradation via microbiologically influenced corrosion (MIC). Here we propose a novel approach to MIC inhibition by designing a system capable of limiting the effects of both bacteria growth and corrosion. The combination of a newly synthesised compound, cetrimonium 4-hydroxycinnamate, with lanthanum 4-hydroxycinnamate was the only system tested to date that could both inhibit abiotic corrosion in artificial seawater and minimise bacteria consortium densities over an exposure period of 24 hours. This success was proposed to be due to their compatibility in the testing environment.Furthermore, we confirmed from cytotoxicity testing that Cet-4OHCin demonstrated similarly limited toxicity towards human cells as the commercially available cetrimonium bromide, a known safe additive to cosmetic products. Thus, this new system shows promise as a safe and effective multifunctional inhibitor to reduce the effects of MIC.