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Solar energy has the potential to supply more than enough energy to meet humanity’s energy demands. Here, a method for thermochemical solar energy storage through fuel production is presented. A porous non-stoichiometric oxide, ceria, undergoes partial thermal reduction and oxidation with concentrated solar energy as a heat source, and water as an oxidant. The resulting yields for hydrogen fuel and oxygen are produced in two discrete steps, while the starting material maintains its original phase.Ordered porosity has been shown superior to random porosity for thermochemical fuel production applications, but stability limits for these structures are currently undefined. Ceria-based inverse opals are currently being investigated to assess the architectural influence on thermochemical hydrogen production. Low tortuosity and continuous interconnected pore network allow for facile gas transport and improved reaction kinetics. Ceria-based ordered materials have recently been shown to increase maximum hydrogen production over non-ordered porous ceria. Thermal stability of ordered porosity was quantified using quantitative image analysis. Fourier analysis was applied to SEM images of the material. The algorithm results in an order parameter gamma that describes the degree of long range order maintained by these structures, where γ>4 signifies ordered porosity. According to this metric, a minimum zirconium content of 20 atomic percent (at%) is necessary for these architectures to survive aggressive annealing up to 1000˚C. Zirconium substituted ceria (ZSC) with Zr loadings in excess of 20at% developed undesired tetragonal phases. Through gamma, we were able to find a balance between the benefit of zirconium additions on structural stability and its negative impact on phase. This work demonstrates the stability of seemingly delicate architectures, and the operational limit for ceria based inverse opals to be 1000˚C for 1µm pore size. Inverse opals having sub-micron pores did not sustain ordered structures after heating, and those larger than 1µm had reinforced structural stability. Furthermore, this analysis was applied to materials which underwent isothermal hydrogen/water redox cycles. ZDC20 inverse opals having 300, 650 and 1000nm pore sizes maintained ordered porosity at 800˚C, indicating a novel opportunity for use at higher temperatures.The mechanism of inverse opal degradation was investigated. Both in situ and ex situ electron microscopy studies were performed on inverse opals subjected to high temperatures. Coarsening by surface diffusion was found to be the dominant grain growth mechanism. The inverse opal grain growth mechanism was found to deviate from that of porous materials due to the high porosity and an upper limit to grain size caused by structural confinement. Furthermore, in situ experiments enabled correlation of nano-scale grain growth to micro-scale feature changes, resulting in an empirical relationship.Lastly, this dissertation presents an investigation of the effect of ordered porosity on hydrogen production rate and quantity. These results differ from those presented in literature, and an opportunity for further investigation is proposed.

Introduction Traumatic injuries to the lower gastrointestinal tract (rectum and anus) have been largely reported in the military setting with sparse publications from the civilian setting. Additionally, there remains a lack of international consensus regarding definitive treatment pathways. This systematic review aimed to assess the current literature and propose a standardised treatment algorithm to aid management in the civilian setting. Methods A systematic review of available literature from 1999 to 2016 that was performed. Primary endpoints were the assessment and surgical management of reported rectal and anal trauma. Results Seven studies were included in this review, reporting on 1255 patients. 96.3% had rectal trauma and 3.7% had anal trauma. Gunshot wounds are the most common mechanism of injury (46.9%). The overwhelming majority of injuries occurred in males (>85%) and were associated with other pelvic injuries. Surgical management has substantially evolved over the last five decades, with no clear consensus on best management strategies. Conclusion There remains significant international discrepancy regarding the management of penetrating trauma to the rectum. Key management principals include the varying use of the direct primary closure, faecal diversion, pre-sacral drainage and/or distal rectal washout (rarely used). To date, there is sparse evidence regarding the management of penetrating anal trauma.

Bacterially derived short chain fatty acids (SCFAs), such as butyrate, are vital in maintaining the symbiotic relationship that exists between humans and their gastrointestinal microbial populations. A key step in this process is the transport of SCFAs across colonic epithelial cells via MCT1 transporters. This study investigated MCT1 protein abundance in various human intestinal tissues. Initial RT-PCR analysis confirmed the expected MCT1 RNA expression pattern of colon > small intestine > stomach. Using surgical resection samples, immunoblot analysis detected higher abundance of a 45 kDa MCT1 protein in colonic tissue compared to ileum tissue (P

Aim Previous meta-analyses of mechanical bowel preparation (MBP) before colorectal surgery have grouped colon and rectal resection together. An increased postoperative morbidity has been suggested in the absence of MBP following proctectomy. The current study used meta-analytical techniques to evaluate the comparative outcome of patients who received MBP prior to proctectomy. Method A comprehensive search was performed for published studies examining the effect of MBP before proctectomy on patient outcome. Random effects methods were used to combine data. Results Eleven studies including 1258 patients were identified. There was no significant difference in overall morbidity (OR 1.062, 95% CI 0.584–1.933, P = 0.844), anastomotic leakage (OR 1.144, 95% CI 0.767–1.708, P = 0.509), surgical site infection (OR 0.946, 95% CI 0.549–1.498, P = 0.812) or mortality (OR 1.377, 95% CI 0.549–3.455, P = 0.495) between those who did not and those who did receive MBP prior to proctectomy. Conclusion The current study did not demonstrate a beneficial effect of MBP prior to proctectomy, but the data were limited. Decision-making as to its use should be made on a case-by-case basis.

Recurrent and locally advanced colorectal cancers frequently require en bloc resection of involved organs to achieve negative margins. The aim of this review is to evaluate the most current literature related to the surgical management of locally advanced and recurrent colorectal cancer. A literature review was performed on the electronic databases MEDLINE from PubMed, EMBASE and the Cochrane library for publications in the English language from January 1993 to July 2013. The MeSH search terms ‘locally advanced colorectal cancer’, ‘recurrent colorectal cancer’ and ‘surgical management’ were used. A total of 1,470 patients with recurrent or locally advanced primary colorectal cancer were included in 22 studies. Surgical removal of the tumour with negative margins (R0) offers the best prognosis in term of survival with a 5-year survival of up to 70 %. MVR is needed in approximately 10 % with the most commonly involved organ being the bladder. The mean post-operative morbidity is 40 %, mainly relating to superficial surgical site infection, pelvic collections and delayed wound healing. Most patients will undergo radiotherapy and/or chemotherapy pre- or post-operatively. The mean 5-year overall survival for R0 resection is 50 % for recurrent and locally advanced primary tumours while survival following R1 or R2 is 12 and

Bacterially derived short chain fatty acids (SCFAs), such as butyrate, are vital in maintaining the symbiotic relationship that exists between humans and their gastrointestinal microbial populations. A key step in this process is the transport of SCFAs across colonic epithelial cells via MCT1 transporters. This study investigated MCT1 protein abundance in various human intestinal tissues. Initial RT-PCR analysis confirmed the expected MCT1 RNA expression pattern of colon small intestine stomach. Using surgical resection samples, immunoblot analysis detected higher abundance of a 45 kDa MCT1 protein in colonic tissue compared to ileum tissue (P 0.001, N = 4, unpaired t-test). Importantly, MCT1 abundance was found to be significantly lower in sigmoid colon compared to ascending colon (P 0.01, N = 8-11, ANOVA). Finally, immunolocalization studies confirmed MCT1 to be abundant in the basolateral membranes of surface epithelial cells of the ascending, transverse, and descending colon, but significantly less prevalent in the sigmoid colon (P 0.05, N = 5-21, ANOVA). In conclusion, these data confirm that basolateral MCT1 protein abundance is correlated to levels of bacterially derived SCFAs along the human gastrointestinal tract. These findings highlight the importance of precise tissue location in studies comparing colonic MCT1 abundance between normal and diseased states.

Spigelian hernias are a rare abdominal wall hernia. The aim of this study was to assess the efficacy and outcomes of patients who underwent a laparoscopic spigelian hernia repair. A retrospective study was performed reviewing all patients who had a laparoscopic spigelian hernia repair. We assessed the success of the procedure including conversion rates, postoperative morbidities, and recurrence rates. Forty patents had a laparoscopic repair. Two thirds (n=25) had an intraperitoneal repair. There was no conversion to open repair. Four patients had postoperative morbidities. At 6-month follow-up all patients were pain free, with 1 recurrence. There is considerable evidence supporting the opinion that laparoscopic repair offers excellent outcomes. This report is the largest series to date, and we advocate that this approach should become the standard of care.

The incidence of locally advanced prostate cancer has decreased in the last few decades since the introduction of screening programmes. Despite earlier detection and treatment, there is still a proportion of late presentation and/or recurrences (around 10 %) of locally advanced prostate cancer. Additionally, sporadic reports of synchronous pelvic neoplasms have been published with various treatment strategies to optimize patient survival. Pelvic exenteration is a technically demanding surgical procedure that is performed for locally advanced, recurrent or synchronous pelvic malignancies. The role of pelvic exenteration in locally advanced prostate cancer has been controversial, as there is a lack of strong statistical evidence to support its role. Despite this, studies have outlined benefits of this procedure, especially in the presence of synchronous pelvic cancers or for palliative indications. Despite advances in surgical care and techniques, pelvic exenteration remains a high-risk procedure with troublesome complications. However, with better patient selection, multi-disciplinary team (tumour board) involvement and surgery being performed in specialist high volumes centres, rates of morbidity and mortality have substantially reduced.

Background Troponin estimation is increasingly performed on emergency medical admissions. We report on a high-sensitivity troponin (hscTn) assay, introduced in January 2011, and its relevance to in-hospital mortality in such patients. Aim To evaluate the impact of hscTn results on in-hospital mortality and the value of incorporating troponin into a predictive score of in-hospital mortality. Methods All patients admitted as general medical emergencies between January 2011 and October 2012 were studied. Patients admitted under other admitting services including cardiology were excluded. We examined outcomes using generalised estimating equations, an extension of generalised linear models that permitted adjustment for correlated observations (readmissions). Margins statistics used adjusted predictions to test for interactions of key predictors while controlling for other variables using computations of the average marginal effect. Results A total of 11 132 admission episodes were recorded. The in-hospital mortality for patients with predefined cut-offs was 1.9% when no troponin assay was requested, 5.1% when the troponin result was below the 25 ng/L ‘normal’ cut-off, 9.7% for a troponin result ≥25 and 1000 ng/L. The OR for an in-hospital death for troponin-positive patients was 2.02 (95% CI 1.84 to 2.21); when adjusted for other mortality predictors including illness severity, the OR remained significant at 2.83 (95% CI 2.20 to 3.64). The incorporation of troponin into a multivariate logistic predictive algorithm resulted in an area under the receiver operating characteristic curve to predict an in-hospital death of 0.87 (95% CI 0.85 to 0.88). Conclusions An increase in troponin carries prognostic information in acutely ill medical patients; the extent of the risk conferred justifies incorporation of this information into predictive algorithms for hospital mortality.

Urea transporters (UTs) encoded by the Slc14a1 (UT-B) and Slc14a2 (UT-A) genes facilitate the movement of urea across plasma membranes. Urea flux into the gastrointestinal tract enhances the growth...

Rectal carcinoids are increasing in incidence worldwide. Frequently thought of as a relatively benign condition, there are limited data regarding optimal treatment strategies for both localized and more advanced disease. The aim of this study was to summarize published experiences with rectal carcinoids and to present the most current data.Following PRISMA guidelines, an electronic literature search performed of PubMed, Medline, Embase, and the Cochrane Library using the terms "rectum" or "rectal" AND "carcinoid" over a 20-year study period from January 1993 to May 2013. Non-English-language studies, animal studies, and studies of fewer than 100 patients were excluded. Study end points included demographic information, tumor features, intervention and outcomes. All included articles were quality assessed.Using the search parameters and exclusions as outlined above, a total of 14 articles were identified for detailed analysis. The quality of articles was low/moderate for all included scoring 9 to 17 of 27. The articles included 4,575 patients diagnosed with a rectal carcinoid. Approximately 80% of tumors were10 mm, 15% 11-20 mm, and 5%20 mm. Eight percent of patients presented with regional lymph node metastases, and 4% presented with distant metastases. Tumor size10 mm, and muscular and lymphovascular invasion are independently associated with an increased risk of metastases. The 5-year survival was 93% in patients presenting with localized disease and 86% overall.Small tumors up to 10 mm without any adverse features can be treated with endoscopic or local excision. The treatment of carcinoids between 10 and 20 mm is still contentious, but those up to 16 mm without adverse feature are suitable for local/endoscopic excision followed by careful histopathological assessment. Those20 mm or with adverse features require radical surgery with mesorectal clearance in suitable patients.

• 1 University of Auckland, School of Psychology, New Zealand Background: Long-term potentiation (LTP) is a form of synaptic plasticity involved in learning and memory. Abnormal levels of LTP have been suggested to contribute to symptoms in a number of disorders, and here we examined the extent to which LTP may be affected in autism spectrum disorders (ASD). While animal models of ASD have suggested LTP may be atypical, the results have been inconsistent in terms of the direction of abnormality. Methods: An EEG paradigm for non-invasively eliciting LTP in humans was applied to a group of adults with ASD and matched neurotypical (NT) controls. This paradigm uses high frequency visual stimulation as the LTP inducing stimulus, and the increase in amplitude of the visually-elicited N1b component of the visual evoked potential (VEP) is taken as the index of LTP. Results: It was found that the ASD group had a significantly larger LTP effect relative to the neurotypical control group. Discussion: These results provide support for the “Intense World” theory, in which hyper-plasticity is thought to underlie cognitive symptoms in ASD. This non-invasive paradigm for eliciting LTP has potential to be applied in a clinical setting as a neural marker for ASD.