A Nonequilibrium Model for Particle Networking/Jamming and Time-Dependent Dynamic Rheology of Filled Polymers.

We describe an approach for modeling the filler network formation kinetics of particle-reinforced rubbery polymers-commonly called filler flocculation-that was developed by employing parallels between deformation effects in jammed particle systems and the influence of temperature on glass-forming materials. Experimental dynamic viscosity results were obtained concerning the strain-induced particle network breakdown and subsequent time-dependent reformation behavior for uncross-linked elastomers reinforced with carbon black and silica nanoparticles. Using a relaxation time function that depends on both actual dynamic strain amplitude and fictive (structural) strain, the model effectively represented the experimental data for three different levels of dynamic strain down-jump with a single set of parameters. This fictive strain model for filler networking is analogous to the established Tool-Narayanaswamy-Moynihan model for structural relaxation (physical aging) of nonequilibrium glasses. Compared to carbon black, precipitated silica particles without silane surface modification exhibited a greater overall extent of filler networking and showed more self-limiting behavior in terms of network formation kinetics in filled ethylene-propylene-diene rubber (EPDM). The EPDM compounds with silica or carbon black filler were stable during the dynamic shearing and recovery experiments at 160 °C, whereas irreversible dynamic modulus increases were noted when the polymer matrix was styrene-butadiene rubber (SBR), presumably due to branching/cross-linking of SBR in the rheometer. Care must be taken when measuring and interpreting the time-dependent filler networking in unsaturated elastomers at high temperatures.

Berkeley Moynihan - early transfusionist and blood transfusion recipient.

Lord Sir Berkeley Moynihan (1865-1936) was a surgeon at the General Infirmary in Leeds (Yorkshire) from 1893, rising during his career to be one of the foremost surgeons in the UK whose reputation reached its pinnacle at the outbreak of the First World War (WW1). He was the only surgeon after Lister to be made a Baronet. In a letter to The Lancet in 1918, he claimed to have used blood transfusion on some of his patients during the 10-year period prior to that date. If true, this statement would make him the first surgeon in England to routinely use transfusion prior to WW1. This review investigates this claim using currently available evidence from Moynihan's personal records and publications, as well as published information from his colleagues.

The unwanted third wheel in the Calot's triangle: Incidence and surgical significance of caterpillar hump of right hepatic artery with a systematic review of the literature.

BACKGROUND: Caterpillar hump of the right hepatic artery is a rare variation increasing the risk of vascular and biliary injuries during hepatobiliary surgery. The aim of this study is to record the cases of the right hepatic artery forming caterpillar hump in a cohort of patients underwent laparoscopic cholecystectomy and to report a review of the literature systematically conducted. METHODS: We reviewed clinical and surgical video data of 230 patients with symptomatic cholelithiasis treated with laparoscopic cholecystectomy between January 2016 and August 2017. A systematic literature search in PubMed, Medline, Cochrane and Ovid databases until 30th June 2017 was also performed in accordance with the PRISMA statement. RESULTS: Our institutional data indicated that 1.3% of 230 patients presented caterpillar hump right hepatic artery. The systematic review included 16 studies reporting data from a total of 498 human cadavers and 579 patients submitted to cholecystectomy. The overall proportion of surgical patients with the caterpillar hump right hepatic artery was 6.9%. CONCLUSIONS: Variations of the cystic artery are not just an anatomical dissertation, assuming a very crucial role in surgical strategies to avoid uncontrolled vascular lesions. A meticulous knowledge of the hepatobiliary triangle in association with all elements of 'Culture of Safety in Cholecystectomy' is mandatory for surgeons facing more than two structures within Calot's triangle.

Dual Cystic Arteries in Association with Caterpillar Hump of Right Hepatic Artery- A Case Report and its Surgical Relevance.

A rare variation was seen in the arterial supply of liver and gall bladder during dissection of an adult female cadaver. The right hepatic artery was having a tortuous course with double loops and cystic artery was arising from the distal loop within the hepatobiliary triangle. There was an accessory cystic artery arising from the superior pancreaticoduodenal artery outside the hepatobiliary triangle which ascended anterior to the common bile duct and cystic duct towards the gall bladder. The knowledge of these vascular variations is very much essential owing to increase in surgical interventions involving the biliary tract. Recognition of such vascular variations is essential for laparoscopic surgeons to reduce complications like uncontrolled intraoperative bleeding, iatrogenic extrahepatic biliary injuries and conversion to open cholecystectomy. This report emphasizes the necessity of all surgeons being well aware of vascular variations and anomalies to be able to accomplish safe and uneventful hepatobiliary surgeries.

Retroanastomotic hernia after Moynihan's gastroenterostomy.

Retroanastomotic hernias after gastroenterostomies-either antecolic or retrocolic-are extremely rare but are associated with high mortality rates due to delayed identification which precludes immediate surgical reduction. In this report, we present a 77-year-old man with retroanastomotic herniation of the efferent loop segments that occurred 14 years after a Moynihan's gastroenterostomy.