The synthesis and evaluation of proton conducting electrolytes for high temperature steam electrolysers

Proton conducting ceramics based on acceptor doped perovskites are the subject of investigation as candidate electrolyte materials for Solid Oxide Electrolyser Cells (SOECs). Specifically, BaCe0.9Y0.1O3-[delta](BCY10) and BaZr0.9Y0.1O3-[delta](BZY10) were investigated. Samples with greater than 95% of the maximum theoretical density were successfully prepared using a BCY10 commercial powder. It was found that when small additions of ZnO were added to a BZY10 commercial powder, a density of greater than 95% of the theoretical maximum was achievable whereas without ZnO addition, the maximum achievable density was 85%. BCY10 was found to have a total conductivity approximately one order of magnitude greater than Zndoped BZY10 over the entire temperature range studied. Spray pyrolysis and sol-gel methods were used successfully to prepare single phase pure BZY10 powders. The sintering behaviours of the powders produced by spray pyrolysis were found to alter significantly with changes in powder processing parameters. BCY10 and Zn-doped BZY10 cells were tested in electrolysis and fuel cell modes and the effects of varying operating conditions on cell performances were studied. At 750oC, the Area Specific Resistances (ASR) of a BCY10 cell in electrolysis mode was found to be lower when the anode compartment was humidified to [approximately equal]83% than to[approximately equal]3%. Below this temperature, ASR values were greater when using increased humidity levels. It was concluded that a degree of oxide ion conduction may be beneficial to the operation of proton conducting electrolysers. Post-test, BCY10 cell cross-sections were imaged using scanning electron microscopy and analysed using Energy Dispersive X-ray (EDX) spectroscopy. Significant erosion of grain boundaries regions close the electrode-electrolyte interfaces was observed and EDX spectroscopy results suggested the formation of a secondary phase in these regions, possibly Y:CeO2. Had testing continued over an extended period of time it is probable that BCY10 cells would have undergone mechanical failure

Effect of distortion on the buckling strength of stiffened panels

This paper predicts the behaviour of stiffened plates with different distortion levels in order to address a rational structural design procedure as pre-existing and fabricationrelated (like weld-induced) initial geometrical distortion is of great importance in structural design point of view. The considered range of scantlings, the distortion typesand levels were chosen, based on panels used at BVT Surface Fleet Ltd., where the type 45 destroyer were under construction. An analytical relation is presented based on Perry's column approach to establish the variation of buckling strength against the geometrical distortion. A parametric form of non linear finite element analysis using ABAQUS has been carried out under axial loading condition to predict the behaviour and the buckling strength. The effect of residual stress is not considered in this study. A new strength parameter is proposed to represent buckling strength which takes into account the inelastic post-buckling behaviour of the structure. The results from FE analysis are plotted in non-dimensional terms and arrived at some important conclusions

Pharmacokinetics of Hyperthermic Intrathoracic Chemotherapy following Pleurectomy and Decortication

In patients with pseudomyxoma peritonei or peritoneal mesothelioma, direct extension of disease through the hemidiaphragm may result in an isolated progression of tumor within the pleural space. We monitored the intrapleural and plasma levels of mitomycin C and doxorubicin by HPLC assay in order to determine the pharmacokinetic behavior of this intracavitary use of chemotherapy. Our results showed a persistent high concentration of intrapleural drug as compared to plasma concentrations. The increased exposure for mitomycin C was 96, and the increased exposure for doxorubicin was 241. When the clearance of chemotherapy from the thoracic cavity was compared to clearance from the abdomen and pelvis, there was a considerably more rapid clearance from the abdomen as compared to the thorax. The pharmacologic study of intrapleural chemotherapy in these patients provides a strong pharmacologic rationale for regional chemotherapy in this group of patients

Intraperitoneal Gemcitabine Chemotherapy Treatment for Patients with Resected Pancreatic Cancer: Rationale and Report of Early Data

Currently, the surgical management of pancreas cancer is recognized around the world as inadequate. Despite a potentially curative R0 resection, long-term survival is rare. There is a strong rationale for the use of chemotherapy in the operating room to reduce local-regional of recurrent/progressive disease. Gemcitabine monotherapy administered by an intraperitoneal route in the operating room with hyperthermia and then for long-term treatment postoperatively has a pharmacologic basis in that the exposure of peritoneal surfaces to intraperitoneal gemcitabine is approximately 200–500 times the exposure that occurs within the plasma. A standardized treatment with intraoperative and long-term chemotherapy that is well tolerated would greatly facilitate further improvements in pancreas cancer treatment and may lead the way to an evolution of more successful treatment strategies of this dread disease. The aim of this paper is to present the early data on a protocol in progress in patients with resected pancreatic cancer

Using Pharmacologic Data to Plan Clinical Treatments for Patients with Peritoneal Surface Malignancy

The surfaces of the abdomen and pelvis are an important anatomic site for the dissemination of gastrointestinal and gynecologic malignancy. This transcoelomic spread of cancer cells gives rise to peritoneal carcinomatosis which, without special treatments, is a fatal manifestation of these diseases. In order to control peritoneal carcinomatosis cytoreductive surgery to remove gross disease is combined with perioperative intraperitoneal and perioperative intravenous chemotherapy to eradicate microscopic residual disease. Chemotherapy agents are selected to be administered by the intraperitoneal or intravenous route based on their pharmacologic properties. A peritoneal-plasma barrier which retards the clearance of high molecular weight chemotherapy from the peritoneal cavity results in a large exposure of small cancer nodules on abdominal and pelvic surfaces. Tissue penetration is facilitated by moderate hyperthermia (41-42ºC) of the intraperitoneal chemotherapy solution. A constant dose of chemotherapy agent and volume of carrier solution based on body surface area allows prediction of systemic drug exposure and systemic toxicity. Timing of the chemotherapy as a planned part of the surgical procedure to maximize exposure of all peritoneal surfaces is crucial to success

Gastrointestinal Complications in 147 Consecutive Patients with Peritoneal Surface Malignancy Treated by Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is increasingly used in the treatment of peritoneal carcinomatosis from gastrointestinal malignancies. The purpose of this study is to reevaluate the incidence of gastrointestinal events and identify risk factors associated with this treatment approach. Between January 1, 2006 and December 31, 2009, 147 patients with appendiceal and colorectal carcinomatosis were treated. Gastrointestinal events were analyzed. The overall incidence of grade I–IV gastrointestinal events was 17%. There were 4 grade III gastrointestinal events that occurred in 4 patients and 11 grade IV gastrointestinal events that occurred in 8 patients. On univariate analysis of grade I–IV events a statistically significant association was observed with the following variables: histological grade, peritoneal cancer index (PCI), small bowel resection, colorectal anastomosis, and the number of anastomoses performed per patient. By multivariate analysis, PCI was identified as the only independent risk factor for gastrointestinal complications. CRS combined with a uniform HIPEC regimen is associated with a 17% gastrointestinal morbidity rate (grade I–IV). The frequency of gastrointestinal complications was associated with a large extent of disease measured by PCI (>30)

Hyperthermic Intraperitoneal Chemotherapy with Melphalan: A Summary of Clinical and Pharmacological Data in 34 Patients

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment option for peritoneal metastases. The optimal agents for HIPEC have not been established. Melphalan is a drug with broad activity and a favorable profile for intraperitoneal application. The purpose of this study is to review our experience using melphalan for HIPEC. Pharmacologic data was obtained. Thirty four patients who underwent CRS for peritoneal metastases received melphalan for HIPEC between 2003 and 2011. The first 10 patients received 70 mg/m 2 ; subsequent 24 received 60 or 70 mg/m 2 . The mean PCI was 21±7. Twenty-eight patients (83%) had a CC score of 1 or 2. The mean length of stay was 18 ± 2 days. Nine patients (26%) had a grade 3 and 6 (17%) had grade 4 morbidity. There were no postoperative deaths. The pharmacologic analysis of plasma to peritoneal fluid levels of melphalan showed an AUC ratio of 33 while the tumor nodules to peritoneal ratio was 8. Melphalan is an acceptable agent for use in HIPEC. The morbidity of intraperitoneal melphalan at the dose of 60-70 mg/m 2 appears acceptable. Further studies comparing the effectiveness of melphalan and other HIPEC agents are needed

Towards modifying the genetic predisposition for glaucoma: An overview of the contribution and interaction of genetic and environmental factors

Glaucoma, the leading cause of irreversible blindness worldwide, is a complex human disease, with both genetic and environmental determinants. The availability of large-scale, population-based cohorts and biobanks, combining genotyping and detailed phenotyping, has greatly accelerated research into the aetiology of glaucoma in recent years. Hypothesis-free genome-wide association studies have furthered our understanding of the complex genetic architecture underpinning the disease, while epidemiological studies have provided advances in the identification and characterisation of environmental risk factors. It is increasingly recognised that the combined effects of genetic and environmental factors may confer a disease risk that reflects a departure from the simple additive effect of the two. These gene-environment interactions have been implicated in a host of complex human diseases, including glaucoma, and have several important diagnostic and therapeutic implications for future clinical practice. Importantly, the ability to modify the risk associated with a particular genetic makeup promises to lead to personalised recommendations for glaucoma prevention, as well as novel treatment approaches in years to come. Here we provide an overview of genetic and environmental risk factors for glaucoma, as well as reviewing the evidence and discussing the implications of gene-environment interactions for the disease

Structures of tetrasilylmethane derivatives C(SiXMe2)4 (X = H, F, Cl, Br) in the gas phase and their dynamic structures in solution.

The structures of the molecules C(SiXMe2)4 (X = H, F, Cl, Br) have been determined by gas electron diffraction (GED). Ab initio calculations revealed nine potential minima for each species, with significant ranges of energies. For the H, F, Cl, and Br derivatives nine, seven, two, and two conformers were modelled, respectively, as they were quantum-chemically predicted to be present in measurable quantities. Variable-temperature 1H and 29Si solution-phase NMR studies and, where applicable, 13C NMR, 1H/29Si NMR shift-correlation, and 1H NMR saturation-transfer experiments are reported for C(SiXMe2)4 (X = H, Cl, Br, and also I). At low temperature in solution two conformers (one C1-symmetric and one C2-symmetric) are observed for each of C(SiXMe2)4 (X = Cl, Br, I), in agreement with the isolated molecule ab initiocalculations carried out as part of this work for X = Cl, Br. C(SiHMe2)4 is present as a single C1-symmetric conformer in solution at the temperatures at which the NMR experiments were performed

Prevalence of diabetic retinopathy in Indigenous and non-Indigenous Australians: a systematic review and meta-analysis

TOPIC: This systematic review and meta-analysis summarises evidence relating to the prevalence of diabetic retinopathy (DR) among Indigenous and non-Indigenous Australians. CLINICAL RELEVANCE: Indigenous Australians suffer disproportionately from diabetes-related complications. Exploring ethnic variation in disease is important for equitable distribution of resources and may lead to identification of ethnic-specific modifiable risk factors. Existing DR prevalence studies comparing Indigenous and non-Indigenous Australians have shown conflicting results. METHODS: This study was conducted following Joanna Briggs Institute guidance on systematic reviews of prevalence studies (PROSPERO ID: CRD42022259048). We performed searches of Medline (Ovid), EMBASE, and Web of Science until October 2021, using a strategy designed by an information specialist. We included studies reporting DR prevalence among diabetic patients in Indigenous and non-Indigenous Australian populations. Two independent reviewers performed quality assessments using a 9-item appraisal tool. Meta-analysis and meta-regression were performed using double arcsine transformation and a random-effects model comparing Indigenous and non-Indigenous subgroups. RESULTS: Fifteen studies with 8219 participants met criteria for inclusion. The Indigenous subgroup scored lower on the appraisal tool compared to the non-Indigenous subgroup (mean score 50% vs 72%, p=0.04). In the unadjusted meta-analysis, DR prevalence in the Indigenous subgroup (30.2% [95%CI: 24.9-25.7]) did not differ significantly (p=0.17) from the non-Indigenous subgroup (23.7% (95%CI: 16.8-31.4]). After adjusting for age and for quality, DR prevalence was higher in the Indigenous subgroup (p-values<0.01), with prevalence ratio point estimates ranging between 1.72-2.58, depending on the meta-regression model. For the secondary outcomes, prevalence estimates were higher in the Indigenous subgroup for diabetic macular oedema (8.7% vs 2.7%, p=0.02) and vision-threatening DR (8.6% vs 3.0%, p=0.03), but not for proliferative DR (2.5% vs 0.8%, p=0.07). CONCLUSION: Indigenous studies scored lower for methodological quality, raising the possibility that systematic differences in research practices may be leading to underestimation of disease burden. After adjusting for age and for quality, we found a higher DR prevalence in the Indigenous subgroup. This contrasts with a previous review which reported the opposite finding of lower DR prevalence using unadjusted pooled estimates. Future epidemiological work exploring DR burden in Indigenous communities should aim to address methodological weaknesses identified by this review