Upgrading of the heavy reformate fraction (HR), containing mainly C 9+ aromatics, is usually performed by dealkylation or by transalkylation with added benzene and/or toluene to obtain the more valuable xylenes. However, when the costs related to the use of benzene and toluene are considered, the one-step dealkylation/ transalkylation of the C 9+ alkylaromatics to xylenes becomes economically attractive. Thus, in a first step, ethylmethylbenzenes (EMB) will have to be dealkylated to toluene, which will then react with the trimethylbenzenes (TMB) present in the HR feed to produce xylenes by transalkylation. Medium pore zeolites will favor dealkylation, whereas large pore zeolites will be more adequate for carrying out the transalkylation reaction. In this work, we present the one-pot synthesis of beta-pentasil aggregates with tunable ratios of the large pore beta to the medium pore component. We show that the close proximity of the beta and pentasil nanocrystals obtained by one-pot co-crystallization synthesis, results in a highly efficient catalyst for the consecutive dealkylation/transalkylation process. The bifunctional catalyst based on the co-crystallized aggregate is more active and selective to xylenes than a catalyst based on a physical mixture of equivalent beta and pentasil nanozeolites synthesized following an analogous procedure. The small crystallite sizes of the co-crystallized zeolites provide the additional advantage of a lower deactivation rate as compared to a reference benchmark catalyst. Results are shown on both, model molecules and industrial HR feed.
BackgroundInfective endocarditis is one of the most common infections among intravenous drug addicts. Its complications can affect many systems, and these can include acute renal failure. There is a scarcity of cases in the literature related to acute renal failure secondary to infective endocarditis treated with peritoneal dialysis. In this paper, the case of a 48-year-old Saudi male is reported, who presented with features suggestive of infective endocarditis and who developed acute kidney injury that was treated successfully with high tidal volume automated peritoneal dialysis. To our knowledge, this is the second report of such an association in the literature.Case presentationA 48-year-old Saudi gentleman diagnosed to have a glucose-6-phosphate dehydrogenase deficiency and hepatitis C infection for the last 9 years, presented to the emergency department with a history of fever of 2 days’ duration. On examination: his temperature = 41 °C, there was clubbing of the fingers bilaterally and a pansystolic murmur in the left parasternal area. The results of the blood cultures and echocardiogram were supportive of the diagnosis of infective endocarditis, and the patient subsequently developed acute kidney injury, and his creatinine reached 5.2 mg/dl, a level for which dialysis is essential for the patient to survive.ConclusionHigh tidal volume automated peritoneal dialysis is highly effective as a renal replacement therapy in acute renal failure secondary to infective endocarditis if no contraindication is present.
Background A perceived increase in the use of biliary stents during endoscopic retrograde cholangiopancreatography (ERCP) was observed by our nursing team leader and brought to the attention of the Director of Endoscopy. Purpose To assess a) biliary stent utilization during ERCP, b) the adherence for stent placement based on published guidelines, and c) the associated cost. Method A chart review of all consecutive patients that underwent ERCP for one year (January 2020 to 2021) at the University of Alberta Hospital (UAH) was performed. The need for biliary stent placement was assessed independently by two blinded reviewers and compared with published guidelines. Costs were calculated using Alberta Health Services fee codes. Result(s) A total of 598 patients (316 F) with mean age of 60±19 years (range 3-99 years) underwent 842 ERCPs. Clinical indications for the initial ERCP were common bile duct (CBD) stones (376, 63%), malignant stricture (84, 14%), benign stricture (49, 8%), bile leak (27, 5%), stent removal (15, 3%), and others (47, 8%). Of the 244 patients that had a follow-up ERCP, the most common indications were stent removal (126, 52%), stent replacement (61, 25%), stent placement (28, 11%), and stone extraction (8, 3%). A total of 296 biliary stents were inserted, of which 223 stents (114 plastic, 109 metal) were inserted during the first ERCP (223/598, 37%) and 73 stents (43 plastic, 30 metal) during follow-up ERCP (73/244, 30%). Of the 296 stents, 79 (27%) were inserted for indications not in accordance with published guidelines (63/223 initial ERCP, and 16/73 follow-up ERCP, kappa=0.62). Most of these were placed in CBD stone cases (61/63 initial ERCP, 6/16 follow-up ERCP). In the subgroup of 376 patients with CBD stones, 61 (16%) underwent stent placement not in accordance with published guidelines. The added cost of such stent insertions and follow-up ERCPs for stent removal was $130,000. Conclusion(s) Stent insertion not in accordance with published guidelines was identified in some patients with CBD stones presenting for ERCP. To reduce unnecessary follow-up procedures and healthcare resource utilization, ERCP stent insertion education based on published guidelines, as well as regular practice audit and feedback are required. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared
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