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Dry anaerobic digestion (dry-AD) is an attractive process for solid wastes such as agri-food waste. However, some limitations mainly associated to lack of effective mixing, can hinder the methane production capacity of the systems. Bulking agent (BA) has been proposed as a solution to the compaction issues in systems without mechanical agitation, such as leaching bed reactors. However, effects of BA are still not clear, and, thus, the factors to consider for its dose has not been optimized yet. This work studies the effect of BA in dry-AD. Two substrates with different characteristics were proposed as models, bean peel as a lignocellulosic substrate and a mixture of food waste as a readily biodegradable substrate. Inert plastic rings were used as BA at different BA:S ratios. Assessed BA:S ratio did not affect the performance of methane production for the lignocellulosic waste, but it did significantly affect to the easily biodegradable substrate, showing up to a 28% of methane production increase. This result could be due to the presence of lignocellulosic compounds in the bean peel, behaving like a natural BA. In assays with an increased bed height, the compaction of the system was more severe, resulting in the rapid acidification of the processes. At these conditions, the positive effect of BA addition was more marked, allowing methane production and no acidification of the system. Thus, the addition of BA is a suitable strategy for improving methane production or stability in dry-AD systems without requiring the stirring of the systems. • Bulking agent (BA) addition is assessed as alternative to stirring in dry AD. • Positive effects by BA was due to an increase of the porosity in the digester bed. • Optimal BA:S ratio was strongly dependent on the characteristics of the substrate. • Low lignocellulosic content substrates were more favoured by BA addition. • BA addition was able to avoid acidification by enhancing the methanogenic activity. [ABSTRACT FROM AUTHOR]

• Changes in disturbances can compromise the KKT matching in modifier adaptation method. • Including the disturbances in gradient estimation allows tracking the NOC of a process. • Implementation of modifier adaptation in laboratory using real data of disturbances. • Columnar flotation can increase its economic performance. In this work, we propose the inclusion of the available information of measured or estimated disturbances in the modifier adaptation methodology for real-time optimization (RTO). The idea is to extend the applicability of this technique to processes wherein the disturbances affect the quantities involved in the necessary optimality conditions of the process. To do so, we include the estimation of process gradients with respect to both the decision variables and disturbances in the methodology. This approach was performed in a laboratory-scale flotation column, where the effects of changes in the feed characteristics on the economic performance of the process were analyzed. The influence of the availability of the disturbance information was also analyzed, considering immediate and delayed availability. In the latter case, the auto regressive integrated moving average model (ARIMA) was used as an estimator in each RTO iteration. The results show that the inclusion of the available disturbance information enables tracking of the optimum of the process under continuously changing feed conditions. [ABSTRACT FROM AUTHOR]

The development of an economic model predictive control (E-MPC) strategy is presented. The strategy uses a novel dynamic flotation model that incorporates the physics of the froth phase in a flotation cell. The dynamic model was previously calibrated and validated using experimental data. Sensitivity analyses were conducted to select a suitable objective function that accounted for both process economics and control variable sensitivities. While the ultimate goal of a rougher flotation cell is to maximise the metallurgical recovery at a steady state for a specified minimum grade, it was evident that the incorporation of air recovery dynamics (which can be measured in real-time) and concentrate grade dynamics (calculated through first-principle models) led to the best results. The addition of a dynamic variable that can be easily measured online, i.e. air recovery, offers great potential to improve plant performance in existing froth flotation systems. Furthermore, a minimum concentrate grade was imposed in the E-MPC strategy. This acts as an economic constraint as it allows the metallurgical recovery to be optimised while ensuring that concentrate grade requirements are met. The dynamic optimisation problem for the E-MPC strategy was discretised using orthogonal collocations, and was implemented in Matlab using automatic differentiation via CasADi. Two typical manipulated variables were considered: air flowrate and pulp height setpoints. Based on laboratory-scale data, the implementation of the E-MPC strategy resulted in improvements ranging from +8 to +22 % in metallurgical recovery, while maintaining the specified grade. This is therefore an encouraging control strategy to explore in larger flotation systems. [Display omitted] • Novel EMPC strategy using dynamic physics-based froth models is presented. • Sensitivity analyses support the construction of a robust objective function. • Objective function includes dynamic air recovery, grade, and steady-state recovery. • Inclusion of dynamic air recovery dynamic improves flotation performance. • Simulation results show improvements of 8–22% in metallurgical recovery. [ABSTRACT FROM AUTHOR]

In this paper, a supervisory layer with real-time optimization (RTO) has been implemented in an experimental laboratory-scale flotation column for copper concentration. A two-stage and modifier adaptation (MA) methodology for RTO has been compared under structural, experimental and dynamic uncertainty. In addition, a gradient-free alternative for MA, called nested modifier optimization, has been proposed and tested. The results show that the KKT updates of the MA approach allow the process optimum to be determined under uncertain scenarios, unlike the two-stage approach. From the perspective of gradient modifiers, the performance of the nested methodology is comparable to the dual approach because previous past values are used to update the modifiers without requiring the gradient estimation step. In addition, the interaction of RTO with the regulatory layer must be considered to propose an optimal implementation. [ABSTRACT FROM AUTHOR]

Introduction: The use of veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) as a direct bridge to heart transplantation (BTT) is not common in adults worldwide. BTT with ECMO is associated with increased early/mid‐term mortality compared with other interventions. In low‐ and middle‐income countries (LMIC), where no other type of short‐term mechanical circulatory support is available, its use is widespread and increasingly used as rescue therapy in patients with cardiogenic shock (CS) as a direct bridge to heart transplantation (HT). Objective: To assess the outcomes of adult patients using VA‐ECMO as a direct BTT in an LMIC and compare them with international registries. Methods: We conducted a single‐center study analyzing consecutive adult patients requiring VA‐ECMO as BTT due to refractory CS or cardiac arrest (CA) in a cardiovascular center in Argentina between January 2014 and December 2022. Survival and adverse clinical events after VA‐ECMO implantation were evaluated. Results: Of 86 VA‐ECMO, 22 (25.5%) were implanted as initial BTT strategy, and 52.1% of them underwent HT. Mean age was 46 years (SD 12); 59% were male. ECMO was indicated in 81% for CS, and the most common underlying condition was coronary artery disease (31.8%). Overall, in‐hospital mortality for VA‐ECMO as BTT was 50%. Survival to discharge was 83% in those who underwent HT and 10% in those who did not, p <.001. In those who did not undergo HT, the main cause of death was hemorrhagic complications (44%), followed by thrombotic complications (33%). The median duration of VA‐ECMO was 6 days (IQR 3‐16). There were no differences in the number of days on ECMO between those who received a transplant and those who did not. In the Spanish registry, in‐hospital survival after HT was 66.7%; the United Network of Organ Sharing registry estimated post‐transplant survival at 73.1% ± 4.4%, and in the French national registry 1‐year posttransplant survival was 70% in the VA‐ECMO group. Conclusions: In adult patients with cardiogenic shock, VA‐ECMO as a direct BTT allowed successful HT in half of the patients. HT provided a survival benefit in listed patients on VA‐ECMO. We present a single center experience with results comparable to those of international registries. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Preamble The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS). [ABSTRACT FROM AUTHOR]

This work completes a series of three studies about the estimation of the cost of extracting vegetable oil from seeds using supercritical CO 2 . The focus of this work was determining the effect of extraction pressure (30, 50, and 70 MPa) in the production cost of a supercritical CO 2 extraction of a packed bed of 2-mm oilseeds in plants with two-extraction vessels with aspect ratio of 4.5, using a superficial velocity of 5 mm/s. When extraction pressure increased while keeping other variables constant, production cost decreased. For 2 × 1 m 3 extraction plants, increasing extraction pressure from 30 to 50 MPa decreased production cost 30.9%, but when extraction pressure further increased from 50 to 70 MPa production cost only decreased 9.9%. Results suggest that the recommended extraction pressure for oilseed extraction is 50 MPa. Also, this work compared plants operating at the three extraction pressures when annual productivity was kept constant (231, 456, or 596 ton of oil per year). The total extraction volume of the plant diminished as the extraction pressure increased. Optimum production cost in these cases was quite similar for plants operating at 30, 50, and 70 MPa, but the total volume of the plant decreased 63.6% when increasing extraction pressure from 30 to 50 MPa for the plant producing 456 ton of oil per year, and an additional 31% when increasing it from 50 to 70 MPa. The lowest production cost estimated was 5.52 USD per kg of oil (optimum extraction time of 2.75 h) in a 4 × 1 m 3 plant processing 2-mm prepressed oilseeds, and operating at 40 °C and 50 MPa. The manuscript includes a sensitivity analysis on production cost as a function of a variation of ±50% of uncertain variables cost (respect to nominal values), which were considered as constant in our previous contributions. That cost items were unitary cost of annual labor, CO 2 , and substrate, being the variation of the last one the more significant effect on production cost. [ABSTRACT FROM AUTHOR]

This study presents the development and validation of a digital twin for a semi-autogenous grinding (SAG) mill controlled by an expert system. The digital twin integrates three key components of the closed-loop operation: (1) fuzzy logic for expert control, (2) a state-space model for regulatory control, and (3) a recurrent neural network to simulate the SAG mill process. The digital twin is combined with a statistical framework for automatically detecting process disturbances (or critical operations), which triggers model retraining only when deviations from expected behavior are identified, ensuring continuous updates with new data to enhance the SAG supervision. The model was trained with 68 h of operational industrial data and validated with an additional 8 h, allowing it to predict mill behavior within a 2.5-min horizon at 30-s intervals with errors smaller than 5%. • Novel digital twin framework integrating fuzzy logic, state-space model and neural networks for SAG mills. • Prediction errors smaller than 5% over 2.5 min horizons at 30 s intervals. • Algorithm for automatic disturbance detection and model retraining upon deviations. • Provides a foundation for developing advanced control systems for SAG mill operations. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new updating price technique is presented to be used in the price-driven coordination methods on nonlinear systems. [•] Coordination method is formulated as feedback loop control. [•] The performance is as good as the ones achieved by a centralized NMPC controller. [•] Changes in the structure of the NMPC controllers are minimal, it is only necessary to add an extra term in the cost function. [Copyright &y& Elsevier]

Abstract: This paper explores the impact of exchange rate pegs on the fiscal stance of emerging markets during the nineties. We empirically show that announcing the pegs had deleterious effects on fiscal discipline, while ‘de facto’ pegs which were not announced delivered superior fiscal outcomes. The evidence suggests that this was due to the initial positive credibility shock of the announcement, which allowed for easier and less costly access to the financing of fiscal deficits in emerging countries. [Copyright &y& Elsevier]

[Display omitted] • A dynamic model for control purposes was developed and simulated. • Froth physics – such as air recovery and busting rate – has been incorporated. • The sensitivity of the fitting parameters to changes has been analysed. • The model showed good adaptability under changes in operating conditions. • Analysis of degrees of freedom showed that two variables are available for control. It is widely accepted that the implementation of model-based predictive controllers (MPC) ensures optimal operation if an accurate model of the process is available. In the case of froth flotation, modelling for control purposes is a challenging task due to inherent process instabilities. Most models for control have only focused on the pulp phase rather than the froth phase, which is usually oversimplified or even neglected. Despite the fact that froth stability can significantly affect the overall performance of flotation cells, there is still a gap in literature regarding flotation models for control purposes that properly include froth physics. In this paper we describe the development of a dynamic flotation model suitable for model predictive control, incorporating equations that describe the physics of flotation froths. Unlike other flotation models for control in the literature, the model proposed here includes important variables related to froth stability, such as bursting rate and air recovery, as well as simplified equations to calculate froth recovery and entrainment. These model equations allow estimating the amount of valuable material reporting to the concentrate, which can be used as a proxy to estimate grade and recovery. Additionally, pulp-froth interface physics was also included in our model, which enables a more accurate prediction of relevant flotation variables. A sensitivity analysis of the parameters showed that two out of seven parameters were highly sensitive. The highly sensitive parameters are the exponential factor n of the equation for the overflowing bubble size, and the constant value a of the equation for the bursting rate. Although the other parameters showed a reasonably lower sensitivity than n and a , the results also revealed that there is a significant difference in the prediction accuracy if the parameters are poorly estimated. Further simulations of important variables for control exhibited a good adaptability to changes in typical variables, such as air and feed flowrates. An analysis of degrees of freedom of the model established that two variables need to be fixed to have a completely determined system. This means that two variables are available for control purposes, which can be air and tailings flowrates (through the manipulation of the respective control valves). This study therefore paves the way for the implementation of a robust dynamic model for flotation predictive control, incorporating important froth phenomena. [ABSTRACT FROM AUTHOR]

Background and Aims: Atrial fibrillation frequently occurs in the postoperative period of cardiac surgery, associated with an increase in morbidity and mortality. The scores POAF, CHA2DS2-VASc and HATCH demonstrated a validated ability to predict atrial fibrillation after cardiac surgery (AFCS). The objective is to develop and validate a risk score to predict AFCS from the combination of the variables with highest predictive value of POAF, CHA2DS2-VASc and HATCH models.Methods: We conducted a single-center cohort study, performing a retrospective analysis of prospectively collected data. The study included consecutive patients undergoing cardiac surgery in 2010-2016. The primary outcome was the development of new-onset AFCS. The variables of the POAF, CHA2DS2-VASc and HATCH scores were evaluated in a multivariate regression model to determine the predictive impact. Those variables that were independently associated with AFCS were included in the final model.Results: A total of 3113 patients underwent cardiac surgery, of which 21% presented AFCS. The variables included in the new score COM-AF were: age (≥75: 2 points, 65-74: 1 point), heart failure (2 points), female sex (1 point), hypertension (1 point), diabetes (1 point), previous stroke (2 points). For the prediction of AFCS, COM-AF presented an AUC of 0.78 (95% CI 0.76-0.80), the rest of the scores presented lower discrimination ability (P < 0.001): CHA2DS2-VASc AUC 0.76 (95% CI 0.74-0.78), POAF 0.71 (95% CI 0.69-0.73) and HATCH 0.70 (95% CI: 0, 67-0.72). Multivariable analysis demonstrated that COM-AF score was an independent predictor of AFCS: OR 1,91 (IC 95% 1,63-2,23).Conclusion: From the combination of variables with higher predictive value included in the POAF, CHA2DS2-VASc, and HATCH scores, a new risk model system called COM-AF was created to predict AFCS, presenting a greater predictive ability than the original ones. Being necessary future prospective validations. [ABSTRACT FROM AUTHOR]

• Real time optimization, Modifier Adaptation and Model Predictive Control is integrated in a single layer to improve the application in industrial processes. • The convergence time is speed up using a direct estimation of modifiers with transient measurements. • The new framework is applied to Williams-Otto reactor where the model and process have significant parametric and structural mismatch. • The results show that the proposed framework reaches closely the real optimal economic operation point. In this work, a dynamic optimizer (DO) is enhanced with elements taken from the Modifier Adaptation (MA) methodology for Real-Time Optimization (RTO). The objective is to use the capability of MA methodologies to reach the real optimum of a process despite the existence of process-model mismatch. The modifiers are computed during a process transient, without waiting for several steady states to occur, speeding up the time required to reach the plant optimum. The architecture proposed includes a modified dynamic optimization, a module for estimating the model states and an additional module for direct estimation of the modifiers during transient. The proposed approach was applied in a well-known benchmark example: the Williams-Otto reactor, where the model and process have significant parametric and structural mismatch. The results show that the proposed integration is capable of bringing the process closer to the real optimal economic operation point. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the accuracy of predicted prosthesis‐patient mismatch (PPM) regarding actual PPM measured postoperatively. To assess the association between PPM and prosthetic valve dysfunction. Methods: Retrospective cohort study including adult patients after aortic valve replacement surgery with a biological prosthesis. Predicted PPM status was determined using mean reference effective orifice area indexed to total body surface (iEOA), without considering reference standard deviations. Postoperative PPM status was determined by measuring iEOA within the first 60 postoperative days. Prosthetic valve dysfunction was defined as thrombosis, pannus, valve degeneration, and/or disruption. Results: 205 patients were enrolled between January 2003 and June 2017: predicted PPM was absent in 52 patients (25.4%), moderate in 137 patients (66.8%), and severe in 16 patients (7.8%). After surgery, the actual postoperative iEOA was measured: 53 (25.9%) did not have PPM, 73 had moderate PPM (35.6%), and 79 had severe PPM (38.5%). Predicted PPM identified the presence of hemodynamically significant actual postoperative PPM (OR = 2.56; 95%CI 1.30–5.05; P =.006), though not its degree of severity. Prosthetic valve dysfunction was more frequent among patients with hemodynamically significant PPM (53.9% vs. 11.3%; P <.001), compared to those without PPM. The association between PPM and prosthetic valve dysfunction was maintained after adjusting for gender, age, and ever‐smoking (OR = 9.03; P <.001). The incidence of thrombosis or pannus was also nonsignificantly higher in patients with moderate or severe PPM. Conclusions: Predicted PPM identifies the presence, possibly not the severity, of actual postoperative PPM. Moderate or severe PPM is associated with prosthetic valve dysfunction. Actual postoperative prosthesis‐patient mismatch measured within 60 postoperative days showed a distinctive hemodynamic profile and presented a stronger association with prosthetic valve dysfunction than predicted prosthesis‐patient mismatch. A. Echocardiographic follow‐up in patients according to the actual postoperative PPM measured within 60 postoperative days. B. Prediction of prosthetic valve dysfunction based on preoperative predicted PPM or on actual postoperative PPM within 60 postoperative days. PPM: prosthesis‐patient mismatch. OR: Odds ratio. [ABSTRACT FROM AUTHOR]

At the time of this writing (July 6, 2020), the mortality rate reported for COVID‐19 in Argentina was <2%. Also, the country's critical care beds are ≤63% occupied. This achievement results from the excellent coordination and action by the Argentine Ministry of Health together with the 23 provinces and the Autonomous City of Buenos Aires of the nation for now. Materials and Methods: Regarding cardiovascular care for patients over 65 years of age, a more accurate analysis could be performed when two comparative half‐yearly periods corresponding to the years 2019 and 2020 (pandemic time) were compared. The data collected regarding this age range revealed issues that had not previously been evaluated in our country. That undoubtedly proposes a different solution for the future based on a strict scientific analysis. Results: The ratio of patients who received stents to those that underwent coronary surgery was 6 to 1, while the ratio of patients who had off‐pump surgery to those that underwent minimally invasive surgery was 69 to 1. Conclusion: An Argentinian perspective regarding cardiovascular care is good because the country has an excellent level of qualified medical training in its cardiac surgery and interventional cardiology services, as well as healthcare infrastructure distributed throughout the country, which will undoubtedly be able to respond to the new challenges posed by the post‐pandemic period. [ABSTRACT FROM AUTHOR]

Background and objectives: The APACHE II score allows predicting in-hospital mortality in patients admitted to intensive care units. However, it is not validated for patients undergoing cardiac surgery, since it does not have a good discriminatory capacity in this clinical scenario. The aim of this study is to determine prognostic value of APACHE II score in postoperative of cardiac surgery. Materials and methods; The study was performed using the cardiac surgery database. Patients undergoing surgery between 2017 and 2018, with APACHE II score calculated at the admission, were included. The ROC curve was used to determine a cut-off value The primary endpoint was in-hospital death. Secondary endpoints included low cardiac output (LCO), stroke, surgical bleeding, and dialysis requirement. A multivariable logistic regression model was developed to adjust to various variables of interest. Results: The study evaluated 559 patients undergoing cardiac surgery. The mean of APACHE II Score was 9.9 (SD 4). The prevalence of in-hospital death was 6.1%. The best prognostic cut-off value for the primary endpoint was 12, with a ROC curve of 0.92. Patients with an APACHE II score greater than or equal to 12 had significantly higher mortality, higher incidence of LCO, stroke, surgical bleeding and dialysis requirement. In a multivariate logistic regression model, the APACHE II score was independently associated with higher in-hospital death (OR, 1.14; 95CI%, 1.08-1.21; p < 0.0001). Conclusions: The APACHE II Score proved to be an independent predictor of in-hospital death in patients undergoing postoperative cardiac surgery, with a high capacity for discrimination. [ABSTRACT FROM AUTHOR]

Introduction: Veno-arterial extracorporeal membrane oxygenation may be used to support patients with refractory cardiogenic shock. Many patients can be successfully weaned, the ability of some medications to facilitate weaning from veno-arterial extracorporeal membrane oxygenation were reported. To date, there are limited studies investigating the impact of levosimendan on veno-arterial extracorporeal membrane oxygenation weaning. The objective of this systematic review and meta-analysis was to assess the effects of levosimendan on successful weaning from veno-arterial extracorporeal membrane oxygenation and survival in adult patients with cardiogenic shock. Methods: We performed a systematic review and meta-analysis (PubMed, the Cochrane Library, and the International Clinical Trials Registry Platform published from the year 2000 onwards) investigating whether levosimendan offers advantages compared to standard therapy or placebo, in cardiogenic shock adult patients treated with veno-arterial extracorporeal membrane oxygenation. The primary outcome was veno-arterial extracorporeal membrane oxygenation successful weaning, whereas secondary outcome was all-cause mortality at the longest follow-up available. We pooled risk ratio and 95% confidence interval using fixed and random effects models according to the heterogeneity. Results: A total of five non-randomized clinical trials comprising 557 patients were included, 299 patients for levosimendan and 258 patients for control groups. The pooled prevalence of veno-arterial extracorporeal membrane oxygenation successful weaning was 61.4% (95% confidence interval 39.8-82.9%), and all-cause mortality was 36% (95% confidence interval 29.6-48.8%). There was a significant increase in veno-arterial extracorporeal membrane oxygenation successful weaning with levosimendan compared to the controls (risk ratio = 1.42 (95% confidence interval 1.12-1.8), p for effect = 0.004, I2 = 71%). A decrease risk of all-cause mortality in the levosimendan group was also observed, risk ratio = 0.62 (95% confidence interval 0.44-0.88), p for effect = 0.007, I2 = 36%. Conclusion: The use of levosimendan on adult patients with cardiogenic shock may facilitate the veno-arterial extracorporeal membrane oxygenation weaning and reduce all-cause mortality. Few articles of this topic are available, and prospective, randomized multi-center trials are warranted to conclude decisively on the benefits of levosimendan in this setting. [ABSTRACT FROM AUTHOR]

Introduction; Postoperative atrial fibrillation (POAFib) occurs in 20 to 40% of patients following cardiac surgery, and is associated with an increased perioperative morbidity and mortality. We aimed to develop and validate a simple clinical risk model for the prediction of POAFib after cardiac surgery. Methods; An analytical single center retrospective cohort study was conducted, including consecutive patients undergoing cardiac surgery between 2004 and 2017 with POAFib. To create the predictive risk score, a logistic regression model was performed using a random sample of 75% of the population. Coefficients of the model were then converted to a numerical risk score, and three groups were defined: low risk (≤1 point), intermediate risk (2-5 points) and high risk (≥6 points). The score was validated using the remaining 25% of the patients. Discrimination was evaluated through the area under the curve (AUC) ROC, and calibration using the Hosmer-Lemeshow (HL) test, calibration plots, and ratio of expected and observed events (E/O). Results; Six thousand five hundred nine patients underwent cardiac surgery: 52% coronary artery bypass grafting (CABG), 20% valve surgery, 14% combined (CABG and valve surgery) and 12% other. New-onset AF occurred in 1222 patients (18.77%). In the multivariate analysis, age, use of cardiopulmonary bypass pump, severe reduction in left ventricular ejection fraction (LVEF), chronic renal disease and heart failure were independent risk factors for POAFib, while the use of statins was a protective factor. The NOPAF score was calculated by adding points for each independent risk predictor. In the derivation cohort, the AUC was 0.71 (CI95% 0.69-0.72), and in the validation cohort the model also showed good discrimination (AUC 0.67 IC 0.64-0.70) and excellent calibration (HL P = 0.24). The E/O ratio was 1 (CI 95%: 0.89-1.12). According to the risk category, POAFib occurred in 5% of low; 11% of intermediate and 27.7% of high risk patients in the derivation cohort (P <0.001), and 5.7%; 12.6%; and 23.6% in the validation cohort respectively (P <0.001) Conclusion: From a large hospitalized population, we developed and validated a simple risk score named NOPAF, based on clinical variables that accurately stratifies the risk of POAFib. This score may help to identify high-risk patients prior to cardiac surgery, in order to strengthen postoperative atrial fibrillation prophylaxis. [ABSTRACT FROM AUTHOR]

A virtual environment (VE) of an industrial splitter has been developed to test a dynamic real-time optimizer prior to on-site deployment. The paper describes the architecture of the VE, which represents the process using the EcosimPro© modeling and simulation software, and a real-time manager to maintain a controlled pace of simulation progress. The virtual process has been integrated with the same commercial predictive controller (Aspen© DMC) as installed in the plant (even with the same configuration) and a dynamic real-time optimizer has been developed in Matlab© and implemented on top of it, allowing the VE to test the optimization layer before deployment in the real factory. The data generated by the plant is stored using InfluxDB©, a time series data platform, for further analysis. The results show that the VE allows revamp studies to be conducted with less cost and more confidence. • A virtual environment (VE) of an industrial process has been developed. • The VE uses the same industrial communication and software as the plant. • The VE allows reliable validation of industrial control software. • The VE increases the confidence of industrial staff in revamping studies. [ABSTRACT FROM AUTHOR]

Anoxic mineralization of BTEX represents a promising alternative for their abatement from O 2 -deprived emissions. However, the kinetics of anoxic BTEX biodegradation and the interactions underlying the treatment of BTEX mixtures are still unknown. An activated sludge inoculum was used for the anoxic abatement of single, dual and quaternary BTEX mixtures, being acclimated prior performing the biodegradation kinetic tests. The Monod model and a Modified Gompertz model were then used for the estimation of the biodegradation kinetic parameters. Results showed that both toluene and ethylbenzene are readily biodegradable under anoxic conditions, whereas the accumulation of toxic metabolites resulted in partial xylene and benzene degradation when present both as single components or in mixtures. Moreover, the supplementation of an additional pollutant always resulted in an inhibitory competition, with xylene inducing the highest degree of inhibition. The Modified Gompertz model provided an accurate fitting for the experimental data for single and dual substrate experiments, satisfactorily representing the antagonistic pollutant interactions. Finally, microbial analysis suggested that the degradation of the most biodegradable compounds required a lower microbial specialization and diversity, while the presence of the recalcitrant compounds resulted in the selection of a specific group of microorganisms. [ABSTRACT FROM AUTHOR]

This paper presents a method to estimate process dynamic gradients along the transient that combined with the idea of Modifier Adaptation (MA) improves the economic cost fuction of the examples presented. The gradient estimation method, called TMA, aims to reduce the large convergence time required for traditional MA in processes of slow dynamics. TMA is used with an economic predictive control with MA (eMPC+TMA) and was applied in two case studies: a simulation of the Williams-Otto reactor and a hybrid laboratory plant based on the Van de Vusse reactor. The results show that eMPC+TMA could reach the plant real steady-state optimum despite process-model mismatch, due to the inclusion of the effect of process dynamics in the TMA algorithm. Despite the estimation errors, the proposed methodology improved the profit of the experimental case study, with respect to the use of an eMPC with no modifiers, by about 20% for the unconstrained case, and by 130% in the constrained case. [ABSTRACT FROM AUTHOR]

Recognition of the P wave is important for the correct characterization of atrial and ventricular arrhythmias. When the P wave is difficult to identify on standard electrocardiography (SECG), either esophageal electrocardiography (EECG) or intracardiac electrocardiography (IC-ECG), central venous catheter may be used. The feasibility of these methods has already been demonstrated, but there is no published study comparing them. This study compared the amplitude of the P wave obtained by IC-ECG with those of the P waves obtained by EECG and SECG. SECG, EECG, and IC-ECG were performed on each patient. IC-ECG and EECG made it possible to register P waves larger than registered by SECG (p <0.00001). The difference between the largest P waves obtained with IC-ECG (5.93 ± 3.56 mm) and EECG (4.67 ± 2.16 mm) was not statistically significant (p = 0.1953). In conclusion, IC-ECG is easy to perform and magnifies the P wave at least as effectively as EECG. [Copyright &y& Elsevier]

[Display omitted] • Model validation supported the implementation feasibility of this model into MPC. • Control vector parametrization was implemented to estimate feed flowrate. • The model predictions follow the same trends in all the variables analysed. Modelling for flotation control purposes is the key stage of the implementation of model-based predicted controllers. In Part I of this paper, we introduced a dynamic model of the flotation process, suitable for control purposes, along with sensitivity analysis of the fitting parameters and simulations of important control variables. Our proposed model is the first of its kind as it includes key froth physics aspects. The importance of including froth physics is that it improves the estimation of the amount of material (valuables and entrained gangue) in the concentrate, which can be used in control strategies as a proxy to estimate grade and recovery. In Part II of this series, experimental data were used to estimate the fitting parameters and validate the model. The model calibration was performed to estimate a set of model parameters that provide a good description of the process behaviour. The model calibration was conducted by comparing model predictions with actual measurements of variables of interest. Model validation was then performed to ensure that the calibrated model properly evaluates all the variables and conditions that can affect model results. The validation also allowed further assessing the model's predictive capabilities. For model calibration and validation purposes, experiments were carried out in an 87-litre laboratory scale flotation tank. The experiments were designed as a randomised 3 2 full factorial design, manipulating the superficial gas velocity and tailings valve position. All experiments were conducted in a 3-phase system (solid-liquid–gas) to ensure that the results obtained, as well as the behaviour of the flotation operation, are as similar as possible to those found in industrial flotation cells. In total, six fitting parameters from the model were calibrated: two terms from the equation for overflowing bubble size; three parameters from the bursting rate equation; and the number of pulp bubble size classes. After the model calibration, simulations were performed to validate the predictions of the model against experimental data. The validation results revealed good agreement between experimental data and model predictions of important flotation variables, such as pulp level, air recovery, and overflowing froth velocity. The high accuracy of the predictions suggests that the model can be successfully implemented in predictive control strategies. [ABSTRACT FROM AUTHOR]

A 67-year-old man presented with chest pain. Clinical examination revealed hypertension (160/90 mm Hg). Electrocardiogram indicated no acute coronary syndrome and cardiac enzymes were normal. Catheterization was performed owing to the patient's continuing chest pain and ascending aortogram revealed irregular aortic wall. A computed tomography image showed the shape of penetrating ulcer. The patient was taken to the operating room and intraoperative examination confirmed the diagnosis of penetrating atherosclerotic ulcer (PAU). Coronary artery bypass graft and bovine pericardial patch repair of PAU was performed. A bovine pericardial patch was done as aortic root was heavily calcified and was easy to handle and more hemostatic. [ABSTRACT FROM AUTHOR]

Abstract: Early antithrombotic therapy after biological aortic valve replacement (AVR) is controversial. The aim of this study was to determine the rate of thromboembolic events (TE) without anticoagulation treatment during the first 3 months after surgery. Out of 143 consecutive patients who underwent biological AVR from January 1998 to December 2004, 127 patients who did not receive anticoagulation were included (89%). Events during the first 3 months after surgery included: 2 strokes (1.5%), 2 major bleedings (1.5%) and 9 deaths (7%) (none of them due to TE). In conclusion, the management of patients without antithrombotic treatment after biological AVR seems to be safe due to a low rate of TE. [Copyright &y& Elsevier]

The deleterious effect of hyperglycemia in coronary artery bypass grafting (CABG) using cardiopulmonary bypass has already been published. However, there is scarce data on the prognostic impact of hyperglycemia after "off-pump" CABG. The purpouse of this study was to determine the prognostic value of the postoperative hyperglycemia (POH) and its association with type 2 diabetes (D2) in patients who underwent an off-pump CABG surgery. The primary endpoint was in-hospital mortality and the secondary endpoint was the appearance of infections within 30 days. We included 465 consecutive post operative off-pump CABG patients admitted to intensive care unit (ICU) between January 2004 to July 2005. We considered POH when the glucose peak level was 200 mg/dl or more. There were 163 (35%) patients who had POH and 301 (65%) who had not. Only 21% of the patients with POH had D2. The incidence of POH in our diabetic population was 58%. The patients with POH had greater incidence of previous acute myocardial infarction, D2, not elective surgery and a higher value in the Euroscore. In comparison with the patients who did not present POH, they had greater incidence of in-hospital mortality (4.3% Vs 0.2%. p: 0.002) and infections (17.4% Vs 7.4%, p: 0.02). When adjusted by the main prognostic factors in cardiac surgery (including D2) the POH proved to be an independent predictor of mortality (p < 0.001) and infections (p < 0.001). The odds ratio for mortality prediction was 1.3 for every 10 mg of glucose elevation and 1.2 for infections. In the multivariate analysis, D2, together with POH resulted as independent predicor of infections. We conclude that among patients admitted to the ICU after off-pump CABG surgery, the POH is a frecuent problem that affects both diabetic and non-diabetic population and it has a deleterious effect in patient's evolution in terms of mortality and infections. [ABSTRACT FROM AUTHOR]