HIPERC: a novel, high performance, economic steel concept for linepipe and general structural use

The HIPERC project has examined the effects of alloying elements and processing conditions in low carbon, < 0.09 wt %., niobium containing, 0.05 - 0.12 wt.%, steels. Laboratory-scale heats and pilot rolling trials simulating air and water-cooled plate production as well as hot-rolled strip production have been made. The effects of C, Mn, Ni, Cu, Cr, Mo, Nb, Ti and B, on transformation characteristics and temperatures of recrystallisation have been determined along with regression equations for characterisation of microstructure, tensile and impact properties, and for the weldability of these steels. The properties of products processed commercially to plate and coil-plate and made into pipe and to plate for structural use were determined and these compared well with the values predicted from the regression equations. The project has shown that excellent combinations of strength, toughness and weldability can be obtained using this steel type. Additional experiences have been gained in the processing of these steels through three commercial rolling mills and benefits were seen with this steel type due to higher production rates and lower amounts of surface dressing compared with steels currently being used to satisfy equivalent property specifications. Recommendations on the limits for niobium in Euronorms have been proposed; concerns relating to weldability have been addressed by proposing varying limits based on the carbon and manganese contents of the steel. This report makes the output of this project available to CEN working groups to support the revision of Euronorms based on the gathered data

Interface modification during oxidation of a glass-ceramic matrix/SiC fibre composite

Oxidation heat treatments between 375{degrees}C and 600{degrees}C for 100 hours in air, have been performed on the calcium aluminosilicate glass-ceramic matrix/SiC fibre reinforced composite CAS/Nicalon (manufactured by Coming, USA). Using a commercial nano-indentation system to perform fibre push-down tests, the fibre-matrix interfacial debond fracture surface energy (G{sub i}) and frictional shear stress ({tau}) have been determined. Modification of interface properties, compared to the as fabricated material, was observed at heat treatment temperatures as low as 375{degrees}C, where a significant drop in G{sub i} and an increase in {tau} were recorded. With 450{degrees}C, 525{degrees}C and 600{degrees}C heat treatments, an increase in G{sub i} but a dramatic increase in {tau} were recorded. Under four-point flexure testing, the as fabricated and the 375{degrees}C heat treated materials displayed tough, composite behaviour with extensive fibre pull out, but at {le}450{degrees}C, brittle failure with minimal fibre pull out, was observed. This transition from tough mechanical response to one of brittleness is due to the large increase in {tau} reducing fibre pull out to a minimum and therefore reducing the total required work of fracture. The large increases in {tau} and G{sub i} have been attributed to the oxidative removal of the lubricating, carbon interface and the compressive residual stresses across the interface

Neuroinflammation and structural injury of the fetal ovine brain following intra-amniotic Candida albicans exposure.

BackgroundIntra-amniotic Candida albicans (C. Albicans) infection is associated with preterm birth and high morbidity and mortality rates. Survivors are prone to adverse neurodevelopmental outcomes. The mechanisms leading to these adverse neonatal brain outcomes remain largely unknown. To better understand the mechanisms underlying C. albicans-induced fetal brain injury, we studied immunological responses and structural changes of the fetal brain in a well-established translational ovine model of intra-amniotic C. albicans infection. In addition, we tested whether these potential adverse outcomes of the fetal brain were improved in utero by antifungal treatment with fluconazole.MethodsPregnant ewes received an intra-amniotic injection of 10(7) colony-forming units C. albicans or saline (controls) at 3 or 5 days before preterm delivery at 0.8 of gestation (term ~ 150 days). Fetal intra-amniotic/intra-peritoneal injections of fluconazole or saline (controls) were administered 2 days after C. albicans exposure. Post mortem analyses for fungal burden, peripheral immune activation, neuroinflammation, and white matter/neuronal injury were performed to determine the effects of intra-amniotic C. albicans and fluconazole treatment.ResultsIntra-amniotic exposure to C. albicans caused a severe systemic inflammatory response, illustrated by a robust increase of plasma interleukin-6 concentrations. Cerebrospinal fluid cultures were positive for C. albicans in the majority of the 3-day C. albicans-exposed animals whereas no positive cultures were present in the 5-day C. albicans-exposed and fluconazole-treated animals. Although C. albicans was not detected in the brain parenchyma, a neuroinflammatory response in the hippocampus and white matter was seen which was characterized by increased microglial and astrocyte activation. These neuroinflammatory changes were accompanied by structural white matter injury. Intra-amniotic fluconazole reduced fetal mortality but did not attenuate neuroinflammation and white matter injury.ConclusionsIntra-amniotic C. albicans exposure provoked acute systemic and neuroinflammatory responses with concomitant white matter injury. Fluconazole treatment prevented systemic inflammation without attenuating cerebral inflammation and injury

Load transfer in ceramic matrix composites

SIGLEGBUnited Kingdo

Modelizacion de la fractura de los haces de fibras en materiales compuestos

In Spanish with English abstractSIGLEGBUnited Kingdo

Power of mentorship for civilian and military acute care surgeons: identifying and leveraging opportunities for longitudinal professional development

Across disciplines, mentorship has been recognized as a key to success. Acute care surgeons, focused on the care of trauma surgery, emergency general surgery and surgical critical care, practice in a wide variety of settings and have unique mentorship needs across all phases of their career. Recognizing the need for robust mentorship and professional development, the American Association for the Surgery of Trauma (AAST) convened an expert panel entitled 'The Power of Mentorship' at the 81st annual meeting in September 2022 (Chicago, Illinois). This was a collaboration between the AAST Associate Member Council (consisting of surgical resident, fellow and junior faculty members), the AAST Military Liaison Committee, and the AAST Healthcare Economics Committee. Led by two moderators, the panel consisted of five real-life mentor-mentee pairs. They addressed the following realms of mentorship: clinical, research, executive leadership and career development, mentorship through professional societies, and mentorship for military-trained surgeons. Recommendations, as well as pearls and pitfalls, are summarized below

Loop ileostomy versus total colectomy as surgical treatment for Clostridium difficile-associated disease: An Eastern Association for the Surgery of Trauma multicenter trial.

The mortality of patients with Clostridium difficile-associated disease (CDAD) requiring surgery continues to be very high. Loop ileostomy (LI) was introduced as an alternative procedure to total colectomy (TC) for CDAD by a single-center study. To date, no reproducible results have been published. The objective of this study was to compare these two procedures in a multicentric approach to help the surgeon decide what procedure is best suited for the patient in need. This was a retrospective multicenter study conducted under the sponsorship of the Eastern Association for the Surgery of Trauma. Demographics, medical history, clinical presentation, APACHE score, and outcomes were collected. We used the Research Electronic Data Capture tool to store the data. Mann-Whitney (continuous data) and Fisher exact (categorical data) were used to compare TC with LI. Logistic regression was performed to determine predictors of mortality. A propensity score analysis was done to control for potential confounders and determine adjusted mortality rates by procedure type. We collected data from 10 centers of patients who presented with CDAD requiring surgery between July 1, 2010 and July 30, 2014. Two patients died during the surgical procedure, leaving 98 individuals in the study. The overall mortality was 32%, and 75% had postoperative complications. Median age was 64.5 years; 59% were male. Concerning preoperative patient conditions, 54% were on pressors, 47% had renal failure, and 36% had respiratory failure. When comparing TC and LI, there was no statistical difference regarding these conditions. Univariate preprocedure predictors of mortality were age, lactate, timing of operation, vasopressor use, and acute renal failure. There was no statistical difference between the APACHE score of patients undergoing either procedure (TC, 22 vs LI, 16). Adjusted mortality (controlled for preprocedure confounders) was significantly lower in the LI group (17.2% vs 39.7%; p = 0.002). This is the first multicenter study comparing TC with LI for the treatment of CDAD. In this study, LI carried less mortality than TC. In patients without contraindications, LI should be considered for the surgical treatment of CDAD. Therapeutic study, level III

Developing and leading a sustainable organization for early career acute care surgeons: Lessons from the inaugural American Association for the Surgery of Trauma Associate Member Council

The associate membership of the American Association for the Surgery of Trauma (AAST) was established in 2019 to create a defined but incorporated entity within the larger AAST for the next generation of acute care surgeons. The Associate Member Council (AMC) was subsequently established in 2020 to provide the new AM with an elected group of leaders who would represent them within the AAST. In its inaugural year, this cohort of junior faculty and surgical trainees had developed for the AM a set of bylaws, a mission statement, a strategic vision, and a succession plan. The experience of the AAST AMC is exemplary of what can be accomplished with collaboration, mentorship, innovation, and tenacity. It has the potential to serve as a template for the creation and vitalization of future professional groups. In this piece, the AMC proposes a blueprint for the successful conception of a new organization