The Effect of Sliding Speed on the Tribological Properties of Ceramic Materials.

Ceramics are considered to be candidate materials for galvanising pot bearing materials due to their excellent corrosion resistance in many molten metals. Galvanising pot roll bearings must have excellent wear resistance, and, therefore, it is important to understand the wear behaviour of prospective bearing materials. This study investigates the friction- and wear-resistant properties of select ceramics, namely, pure hBN, BN M26, AlN-BN, Macor, 3YSZ, Al2O3 and Si3N4. The ceramics were tested at different sliding speeds using a pin-on-disc device equipped with SiC pins. The lowest coefficient of friction (COF) achieved was below 0.1, and it was measured for pure hBN at a 3.14 m/min sliding speed. However, a wear scar analysis showed that the BN grades suffered from severe wear. The highest wear rate was obtained for BN M26 at a 9.42 m/min sliding speed and was equal to 17.1 × 10-6 mm3 N-1 m-1. It was shown that the wear coefficient of the tested ceramics varied exponentially with hardness. The lowest wear was observed on the 3YSZ, Al2O3 and Si3N4 ceramics, which showed no volume loss, and, for this reason, they can be potentially used as bearing materials in continuous galvanising lines.

Practical Guide to Measuring Wetland Carbon Pools and Fluxes.

Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions. Supplementary Information: The online version contains supplementary material available at 10.1007/s13157-023-01722-2.

Intraductal tubulopapillary neoplasm.

A man aged above 70 years old with a medical history of ulcerative colitis presented with unintentional weight loss. A pancreatic mass associated with pancreatic duct dilatation was detected on imaging procedures. Initial investigations including fine needle aspiration and cytology examination were inconclusive. A diagnosis of intraductal tubulopapillary neoplasm (ITPN) was made with histopathology and immunohistochemistry examination on a surgically resected specimen. Two years after surgery, the patient remained well with no radiological evidence of recurrence.ITPN is a rare pancreatic duct tumour with limited case reports in medical literature. Risk factors are not well established. We report the first case of ITPN occurring in a patient with ulcerative colitis. A typical presentation of this rare tumour is reported to encourage clinicians to consider ITPN in the differential diagnoses of a pancreatic mass.

Continuous In-Line Chromium Coating Thickness Measurement Methodologies: An Investigation of Current and Potential Technology.

Coatings or films are applied to a substrate for several applications, such as waterproofing, corrosion resistance, adhesion performance, cosmetic effects, and optical coatings. When applying a coating to a substrate, it is vital to monitor the coating thickness during the coating process to achieve a product to the desired specification via real time production control. There are several different coating thickness measurement methods that can be used, either in-line or off-line, which can determine the coating thickness relative to the material of the coating and the substrate. In-line coating thickness measurement methods are often very difficult to design and implement due to the nature of the harsh environmental conditions of typical production processes and the speed at which the process is run. This paper addresses the current and novel coating thickness methodologies for application to chromium coatings on a ferro-magnetic steel substrate with their advantages and limitations regarding in-line measurement. The most common in-line coating thickness measurement method utilized within the steel packaging industry is the X-ray Fluorescence (XRF) method, but these systems can become costly when implemented for a wide packaging product and pose health and safety concerns due to its ionizing radiation. As technology advances, nanometer-scale coatings are becoming more common, and here three methods are highlighted, which have been used extensively in other industries (with several variants in their design) which can potentially measure coatings of nanometer thickness in a production line, precisely, safely, and do so in a non-contact and non-destructive manner. These methods are optical reflectometry, ellipsometry and interferometry.

Inhibition of Wnt signalling by Notch via two distinct mechanisms.

Notch and Wnt are two essential signalling pathways that help to shape animals during development and to sustain adult tissue homeostasis. Although they are often active at the same time within a tissue, they typically have opposing effects on cell fate decisions. In fact, crosstalk between the two pathways is important in generating the great diversity of cell types that we find in metazoans. Several different mechanisms have been proposed that allow Notch to limit Wnt signalling, driving a Notch-ON/Wnt-OFF state. Here we explore these different mechanisms in human cells and demonstrate two distinct mechanisms by which Notch itself, can limit the transcriptional activity of ß-catenin. At the membrane, independently of DSL ligands, Notch1 can antagonise ß-catenin activity through an endocytic mechanism that requires its interaction with Deltex and sequesters ß-catenin into the membrane fraction. Within the nucleus, the intracellular domain of Notch1 can also limit ß-catenin induced transcription through the formation of a complex that requires its interaction with RBPjκ. We believe these mechanisms contribute to the robustness of cell-fate decisions by sharpening the distinction between opposing Notch/Wnt responses.

Australia after Bawa-Garba: Does Reflective Learning Remain Tenable for Health Care Practitioners?

Should a written reflection about regrets be part of the private life of a doctor - or of any health care practitioner - or something that can be used in the public domain when things do go wrong? This article examines the tenability of reflective practice in Australia after the Bawa-Garba cases, outlining the options for the future of reflective practice, and assessing the options ranging from maintaining the current status quo to protecting the use of reflections via absolute legal privilege. In particular, this article explores the value of reflective practice in the broader context, weighing up which of the options for change to reflective practice bring with it the greatest enhancement to public safety. This work concludes by suggesting a potential method for allowing the continued safe implementation of reflective practice by stakeholder groups: briefly considering the novel proposition in the Williams Review that could be adopted in Australia.

Determinants influencing immediate breast reconstruction in an Australian tertiary public hospital.

BACKGROUND: In Australia, the rate of immediate breast reconstruction (IBR) following breast cancer surgery is highly variable. This study aimed to identify the rate of IBR within an Australian public tertiary breast oncology referral centre and analyse the tumour and demographic factors that impact upon IBR uptake. METHODS: A retrospective cohort study of 288 admissions of women requiring mastectomy between January 2012 and March 2015 was performed. Data collected included demographic data, tumour pathology, operative details and neoadjuvant therapy. Demographic data included a Socioeconomic Index for Area score, based on individual residential postcode, country of birth and need for an interpreter. RESULTS: Our study demonstrated an IBR rate of 41.3% and included a wide variety of reconstructions. Factors that increased the IBR rate included younger age and negative lymph node status. Our patient population was ethnically and linguistically diverse, with over 50 different countries of birth represented and with 53 patients requiring interpreters in 19 different languages. Our analysis shows that the requirement for an interpreter is negatively correlated with having an IBR. CONCLUSIONS: Our research demonstrates a high rate of IBR that includes a wide range of autologous and alloplastic reconstructions. Our study represents a unique opportunity to identify socioeconomic barriers that influence patient choice for reconstruction following mastectomy. This can lead to improved health care provision for our patients. This is particularly important in tertiary services with a strong multicultural and multi-linguistic population.

Differentiation of a Contractile, Ureter-Like Tissue, from Embryonic Stem Cell-Derived Ureteric Bud and Ex Fetu Mesenchyme.

BACKGROUND: There is intense interest in replacing kidneys from stem cells. It is now possible to produce, from embryonic or induced pluripotent stem cells, kidney organoids that represent immature kidneys and display some physiologic functions. However, current techniques have not yet resulted in renal tissue with a ureter, which would be needed for engineered kidneys to be clinically useful. METHODS: We used a published sequence of growth factors and drugs to induce mouse embryonic stem cells to differentiate into ureteric bud tissue. We characterized isolated engineered ureteric buds differentiated from embryonic stem cells in three-dimensional culture and grafted them into ex fetu mouse kidney rudiments. RESULTS: Engineered ureteric buds branched in three-dimensional culture and expressed Hoxb7, a transcription factor that is part of a developmental regulatory system and a ureteric bud marker. When grafted into the cortex of ex fetu kidney rudiments, engineered ureteric buds branched and induced nephron formation; when grafted into peri-Wolffian mesenchyme, still attached to a kidney rudiment or in isolation, they did not branch but instead differentiated into multilayer ureter-like epithelia displaying robust expression of the urothelial marker uroplakin. This engineered ureteric bud tissue also organized the mesenchyme into smooth muscle that spontaneously contracted, with a period a little slower than that of natural ureteric peristalsis. CONCLUSIONS: Mouse embryonic stem cells can be differentiated into ureteric bud cells. Grafting those UB-like structures into peri-Wolffian mesenchyme of cultured kidney rudiments can induce production of urothelium and organize the mesenchyme to produce rhythmically contracting smooth muscle layers. This development may represent a significant step toward the goal of renal regeneration.

Australia after Cresswell and Chapman: A Legal and Regulatory Paradox, or an Opportunity for Uniformity?

Australia, like many overseas jurisdictions, has recognised the need to cope with advancing medical technology and changing community attitudes towards assisted reproductive technology (ART). Despite this, several States in Australia still do not have legislative instruments regulating ART, and those that have legislated have done so in a non-uniform way. In 2018/2019, four cases came before State Supreme Courts, where the female applicants had to endure significant legal battle in order to utilise their late partner's gametes, highlighting the inability of the law to provide an appropriate clinical framework. This article outlines and discusses the current position of Australian States on the utilisation of posthumous gametes and how the recent decisions of the Supreme Courts of New South Wales, Queensland and Western Australia augment the current law and National Health and Medical Research Council Guidelines, and finally, considers how future legislation might account for the potential posthumous utilisation of oocytes.

Effects of Two Competitive Soccer Matches on Landing Biomechanics in Female Division I Soccer Players.

Fatigue has been proposed to increase the risk of knee injury. This study tracked countermovement jump, knee isometric strength, and kinetics and kinematics in 8 female soccer players (experimental group) during an anticipated sidestep maneuver before and after two matches played over a 43-h period. Time points were: Before and after match 1 (T0 and T1), 12 h after the first match (T2), and immediately after the second match (T3). A control group participated only in practice sessions. Isometric knee extension strength decreased by 14.8% at T2 (p = 0.003), but knee flexion was not affected until T3, declining by 12.6% (p = 0.018). During the sidestep maneuver, knee joint degrees of flexion at initial contact was increased by 17.1% at T3, but maximum knee and hip angle at initial contact were unchanged. Peak resultant ground reaction force (GRF) increased by 12.6% (p = 0.047) at T3 (3.03 xBW) from 2.69 xBW at T0, while posterior GRF was significantly higher than T0 at all three subsequent time points (T1 = 0.82 ± 0.23 xBW, T2 = 0.87 ± 0.22 xBW, T3 = 0.89 ± 0.22 xBW). Anterior tibial shear force increased significantly (p = 0.020) at T3 (1.24 ± 0.12 xBW) compared to T1 (1.15 ± 0.13 xBW), an 8.8% increase. Lateral tibial shear force was significantly higher at both T1 (0.95 ± 0.20 xBW) and T3 (1.15 ± 0.38 xBW) compared to T0 (0.67 ± 0.25 xBW). These findings suggest that participation in a soccer match has significant effects on both physical performance parameters and kinetics/kinematics during a sidestep cut, but these can be more pronounced after a second match with short rest.

X-ray micro-computed tomography as a non-destructive tool for imaging the uptake of metal nanoparticles by graphene-based 3D carbon structures.

Graphene-based carbon sponges can be used in different applications in a large number of fields including microelectronics, energy harvesting and storage, antimicrobial activity and environmental remediation. The functionality and scope of their applications can be broadened considerably by the introduction of metallic nanoparticles into the carbon matrix during preparation or post-synthesis. Here, we report on the use of X-ray micro-computed tomography (CT) as a method of imaging graphene sponges after the uptake of metal (silver and iron) nanoparticles. The technique can be used to visualize the inner structure of the graphene sponge in 3D in a non-destructive fashion by providing information on the nanoparticles deposited on the sponge surfaces, both internal and external. Other deposited materials can be imaged in a similar manner providing they return a high enough contrast to the carbon microstructure, which is facilitated by the low atomic mass of carbon.

Millimeter-Scale Unipolar Transport in High Sensitivity Organic-Inorganic Semiconductor X-ray Detectors.

Hybrid inorganic-in-organic semiconductors are an attractive class of materials for optoelectronic applications. Traditionally, the thicknesses of organic semiconductors are kept below 1 µm due to poor charge transport in such systems. However, recent work suggests that charge carriers in such organic semiconductors can be transported over centimeter length scales opposing this view. In this work, a unipolar X-ray photoconductor based on a bulk heterojunction architecture, consisting of poly(3-hexylthiophene), a C70 derivative, and high atomic number bismuth oxide nanoparticles operating in the 0.1-1 mm thickness regime is demonstrated, having a high sensitivity of ∼160 µC mGy-1 cm-3. The high performance enabled by hole drift lengths approaching a millimeter facilitates a device architecture allowing a high fraction of the incident X-rays to be attenuated. An X-ray imager is demonstrated with sufficient resolution for security applications such as portable baggage screening at border crossings and public events and scalable medical applications.

Protecting the Continued Development of Collaborative Expert Witness Evidence in Australia: Surely We Should?

Australia has recognised the need to cope with changing attitudes towards advocate and expert witness immunity. While some international jurisdictions have chosen to abolish the immunity altogether, Australia has most recently, via the High Court decisions in Attwells v Jackson Lalic Lawyers Pty Ltd [2016] HCA 16 and Kendirjian v Lepore [2017] HCA 13, recognised the need for the immunity to exist, albeit with significantly narrowed scope. Generally, the principles and scope of expert witness immunity tend to follow that of advocate immunity. However, Australia is widely accepted as the most advanced judicial system supporting the use of concurrent expert evidence. This analysis discusses the unique position of Australia after these two High Court decisions that shape expert witness immunity, recognising the ongoing policy of protecting the finality of litigation. However, the legislature must be careful not to maintain this as the foremost reason for the immunity merely because the courts have chosen this pathway previously. Nor should the legislature merely maintain the status quo of expert witness immunity following advocate immunity.

Unplanned postoperative reintubation following general and vascular surgical procedures: Outcomes and risk factors.

BACKGROUND: Unplanned postoperative reintubation (UPR) is a marker for severe adverse outcomes following general and vascular surgery. STUDY DESIGN: A retrospective analysis of 8809 adult patients, aged 18 years and older, who underwent major general and vascular surgery at a large single-center urban hospital was conducted from January 2013 to September 2016. Patients were grouped into those who experienced UPR and those who did not. Univariate and multivariate regression analyses were used to identify predictors of UPR, and association of UPR with adverse postoperative outcomes. All regression models had Hosmer-Lemeshow P > 0.05, and C-statistic >0.75, indicating excellent goodness-of-fit and discrimination. RESULTS: Of the 8809 patients included, 138 (1.6%) experienced UPR. There was no statistical difference in incidence of UPR between general and vascular surgery patients (p = 0.53). Independent predictors of UPR advanced age (OR 5.1, 95%CI 3.5-7.5, p < 0.01), higher ASA status (OR 7.9, 95%CI 5.6-11.1, p < 0.01), CHF (OR 7.0, 95%CI 3.6-13.9, p = 0.02), acute renal failure or dialysis (OR 3.1, 95%CI 1.8-5.7, p = 0.01), weight loss (OR 5.2, 95%CI 2.8-9.6, p = 0.01), systemic sepsis (OR 4.8, 95%CI 3.4-6.9, p < 0.01), elevated preoperative creatinine (OR 4.2, 95%CI 3.0-5.9, p = 0.01), hypoalbuminemia (OR 5.3, 95% CI 3.8-7.5, p = 0.01), and anemia (OR 4.0, 95%CI 2.8-5.9, p < 0.01). Following surgery, UPR was associated with increased mortality (OR 3.8, 95%CI 2.7-5.2, p < 0.01), pulmonary complications (OR 1.8, 95%CI 1.7-2.0, p < 0.01), renal complications (OR 2.6, 95%CI 1.7-3.5, p < 0.01), cardiac complications (OR 4.6, 95%CI 2.0-6.7, p < 0.01), postoperative RBC transfusion (OR 5.7, 95%CI 3.8-8.6,p < 0.01), and prolonged hospitalization (OR 1.8, 95%CI 1.5-2.4, p < 0.01). CONCLUSION: UPR is significantly associated with postoperative morbidity and mortality. Perioperative management aimed at decreasing incidences of UPR after noncardiac surgery should target preoperative anemia in addition to previously identified predictors.

Hepatic angiosarcoma as a cause of acute liver failure.

Hepatic angiosarcoma is an extremely rare disease entity that accounts for approximately 0.1%-2% of primary liver malignancy. It is three times more common in men than women and usually affects the former in their sixth or seventh decade of life. Risk factors for the development of hepatic angiosarcoma include the use of oral contraceptives, exposure to anabolic steroids, radiation, thorium dioxide, arsenic and vinyl chloride. The prognosis of hepatic angiosarcoma is extremely poor which is attributable to early metastases to other organs, resistance to traditional chemotherapy and radiotherapy regimens and rapid progression of the tumour. Optimal management of patients is poorly demarcated due to the rarity of the tumour. We present a case series of two patients: one who passed away due to acute hepatic failure secondary to hepatic angiosarcoma and the second who underwent a liver transplantation and was subsequently diagnosed with hepatic angiosarcoma based on his explant histology.

Risk factors contributing to cardiac events following general and vascular surgery.

BACKGROUND: Cardiac events (CE) following surgery have been associated with morbidity and mortality. Defining risk factors that contribute to CE is essential to improve surgical outcomes. STUDY DESIGN: This was a retrospective study at a large urban teaching hospital for surgery performed from 2013 to 2015. Adult patients (≥18 years) that underwent general and vascular surgery were analyzed. Patients were grouped into those who experienced postoperative CE and those who did not. Univariate and multivariate regression analyses were used to identify predictors of postoperative CE, and association of CE with adverse postoperative outcomes. Separate subgroup analyses were also conducted for general and vascular surgery patients to assess predictors of CE. RESULTS: Out of 8441 patients, 157 (1.9%) experienced CE after major general and vascular surgery. Underlying predictors for CE included age >65 years(OR 4.9, 95%CI 3.4-6.9,p < 0.01), ASA >3(OR 12.0, 95%CI 8.5-16.9,p < 0.01), emergency surgery(OR 3.7, 95%CI 2.7-5.1,p = 0.01), CHF(OR 11.2, 95%CI 6.4-16.7,p = 0.02), COPD(OR 3.9, 95%CI 2.4-6.4,p = 0.04), acute renal failure or dialysis(OR 8.0, 95%CI 5.2-12.1,p = 0.04), weight loss(OR 3.3, 95%CI 1.7-6.7,p < 0.01), preoperative creatinine >1.2 mg/dL(OR 5.1, 95%CI 3.7-7.1,p = 0.01), hematocrit <34%(OR 4.0, 95%CI 2.8-5.7,p < 0.01), and operative time >240 min(OR 2.0, 95%CI 1.3-3.3,p = 0.02). Following surgery, CE was associated with increased mortality(OR 3.5, 95%CI 1.2-6.5,p < 0.01), pulmonary complications(OR 5.0, 95%CI 3.1-8.9,p < 0.01), renal complications(OR 2.3, 95%CI 1.9-4.5,p < 0.01), neurologic complications(OR 2.5, 95%CI 1.4-5.2,p < 0.01), systemic sepsis(OR 2.2, 95%CI 1.7-4.0,p < 0.01), postoperative RBC transfusion(OR 4.4, 95%CI 2.7-6.5,p < 0.01), unplanned return to operating room(OR 4.0, 95%CI 2.3-6.9,p < 0.01), and prolonged hospitalization (OR 5.5, 95%CI 3.1-8.8,p = 0.03). There was no statistical difference in incidence of CE between general and vascular surgery patients (p = 0.44); however, predictors of CE differed between the two surgical groups. CONCLUSION: Postoperative CE are associated with significant morbidity and mortality. Identified predictors of CE should allow for adequate risk stratification and optimization of perioperative surgical management.

Breast Implant-Associated Anaplastic Large Cell Lymphoma: Case Report and Review of the Literature.

We are reporting the case of a 58-year-old woman with history of bilateral silicone breast implants for cosmetic augmentation. At 2-year interval from receiving the breast implants, she presented with swelling of the right breast with associated chest wall mass, effusion around the implant, and axillary lymphadenopathy. Pathology confirmed breast implant-associated anaplastic large cell lymphoma (stage III, T4N2M0, using BIA-ALCL TNM staging and stage IIAE, using Ann-Arbor staging). The patient underwent bilateral capsulectomy and right partial mastectomy with excision of the right breast mass and received adjuvant CHOP chemotherapy and radiation to the right breast and regional nodes. Since completion of multimodality therapy, the patient has sustained remission on both clinical exam and PET/CT scan. We report this case and review of the literature on this rare form of lymphoma.

Carbon Dioxide Insufflation Increases Colonoscopic Adenoma Detection Rate Compared With Air Insufflation.

GOALS: To determine the effect of carbon dioxide insufflation on the most important outcome measure of colonoscopic quality: adenoma detection rate (ADR). BACKGROUND: Bowel cancer is the second most common cause of cancer deaths in males and females in Australia. Carbon dioxide has in recent times become the insufflation methodology of choice for screening colonoscopy for bowel cancer, as this has been shown to have significant advantages when compared with traditional air insufflation. STUDY: Endoscopies performed over a period of 9 months immediately before and after the implementation of carbon dioxide insufflation at endoscopy centers were eligible for inclusion. RESULTS: The difference in ADR between the carbon dioxide and air insufflation methods was statistically significant, with an increased ADR in the carbon dioxide group. The superiority of carbon dioxide insufflation was sustained with a logistic regression model, which showed ADR was significantly impacted by insufflation method. CONCLUSIONS: Carbon dioxide insufflation is known to reduce abdominal pain, postprocedural duration of abdominal pain, abdominal distension, and analgesic requirements. This study represents for the first time the beneficial effect of carbon dioxide insufflation upon the key quality colonoscopy indicator of ADR.