Using a suitable process model based on oxygen metabolism and an a priori objective function, a hybrid control law is derived that can use online measurements and the states predicted by SAN for computing the desired control action.
RESULTS: The performance
of the SAN-hybrid controller is tested for simulated fed-batch production of methionine for three different process conditions. Simulations assume that online measurements of dissolved oxygen (DO) concentration are available. The performance of the SAN-hybrid controller gave an NRMSE of similar to 10(-4) in the absence of noise, similar to 10(-3) and similar to 10(-2) for +/- 5% and +/- 10% noise in the DO measurement and similar to 10(-2) for parameter uncertainty when compared with the ideal model prediction.
CONCLUSIONS: LDC000067 nmr GW2580 Protein Tyrosine Kinase inhibitor The observed performance for unmeasured state prediction and control implementation shows that the proposed SAN-hybrid controller can efficiently compute the manipulated variable required to maintain methionine production along the optimized trajectory for different conditions. The test results show that the SAN-hybrid controller can be used for online real-time implementation in fed-batch bioprocesses. (C) 2009 Society of Chemical Industry”
“Objectives: To study incidence, handling and outcome of patients hospitalised with
symptomatic and ruptured abdominal aortic aneurysm in Norway.
Design, material and methods: Retrospective study of 1291 patients, between January 2008 and August 2010 using the National Patient Registry and a regional vascular surgery registry. We applied a stepwise logistic regression model to detect differences in regional in-hospital mortality.
Results: 385/711 (54%) patients hospitalised for aneurysm rupture, rAAA (ICD-10:171.3), died. The odds of dying
varied with a factor 2.3 between the extreme regions. 475/711 (67%) underwent repair, 323 survived, giving an in-hospital mortality rate of 32% after surgery. Older patients were significantly less likely to be transported for surgery. The overall incidence for patients aged >50 was 16.6 rAAA per 100 000 person-years. There was remarkable variation across counties with rates between 7.7 and 26.8. A total of HM781-36B purchase 580 patients were hospitalised with suspected symptomatic aneurysms (ICD-10:171.4, acute admission); 224 (39%) were treated with aneurysm repair, 356 (61%) were discharged without repair without a significant difference across health regions.
Conclusions: For rAAA, we found substantial geographical variations in incidence, surgery and patient outcome. These results highlight the need for increased awareness about the condition and suggest ways to improve care trajectories to reduce delay to surgery, thereby minimising rupture mortality. (C) 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.