•Techno-economic model for flexibly operated power & biomass-to-X plants.•Sizing criteria of process units in plants conceived to operate flexibly discussed.•Electricity price curves affect the ...operating modes of power & biomass-to-X plants.•Power & biomass-to-X plants require low average electricity prices.•Flexibly operated plants favoured if 10-20% of time with high electricity prices.
This paper assesses the optimal design criteria of a flexible power and biomass to methanol (PBtM) plant, conceived to operate both without green hydrogen addition (baseline mode) and with hydrogen addition (enhanced mode), following an intermittent use of the electrolysis system, which is turned on when the electricity price allows an economically viable hydrogen production. The assessed plant includes a gasification section, syngas cleaning and compression, methanol synthesis and purification and heat recovery steam cycle, to be flexibly operated. A sorption-enhanced gasification technology allows to produce a tailored syngas for the downstream synthesis in both the baseline and enhanced operating conditions, by controlling the in-situ CO2 separation rate. Two designs are assessed for the methanol synthesis unit, with two different reactor sizes: (i)a larger reactor, designed on the enhanced operation mode (enhanced reactor design – ERD) and (ii)a smaller reactor, designed on the baseline operation mode (baseline reactor design – BRD). The ERD design resulted to be preferable from the techno economic perspectives, resulting in 20% lower cost of the e-MeOH (30.80 vs. 37.76€/GJLHV) with the baseline assumptions (i.e. 80% of electrolyzer capacity factor and 2019 Denmark day-ahead market electricity price). Other important outcomes are: (i)high electrolysis capacity factor is needed to obtain competitive cost of e-MeOH and (ii)advantages of flexibly operated PBtM plants with respect to inflexible PBtM plants are significant in scenarios with high penetration of intermittent renewables, leading to low average prices of electricity but also longer periods of high peak prices.
Prescription opioids are a major contributor to the ongoing epidemic of persistent opioid use (POU). The incidence of POU among opioid-naïve patients after cardiac implantable electronic device ...(CIED) procedures is unknown.
This retrospective cohort study used data from a national administrative claims database from 2004 to 2018 of patients undergoing CIED procedures. Adult patients were included if they were opioid-naïve during the 180-day period before the procedure and did not undergo another procedure with anesthesia in the next 180 days. POU was defined by filling an additional opioid prescription >30 days after the CIED procedure.
Of the 143 400 patients who met the inclusion criteria, 15 316 (11%) filled an opioid prescription within 14 days of surgery. Among these patients, POU occurred in 1901 (12.4%) patients 30 to 180 days after surgery. The likelihood of developing POU was increased for patients who had a history of drug abuse (odds ratio, 1.52;
=0.005), preoperative muscle relaxant (odds ratio, 1.52;
<0.001) or benzodiazepine (odds ratio, 1.23;
=0.001) use, or opioid use in the previous 5 years (OR, 1.76;
<0.0001). POU did not differ after subcutaneous implantable cardioverter defibrillator or other CIED procedures (11.1 versus 12.4%;
=0.5). In a sensitivity analysis excluding high-risk patients who were discharged to a facility or who had a history of drug abuse or previous opioid, benzodiazepine, or muscle relaxant use, 8.9% of the remaining cohort had POU. Patients prescribed >135 mg of oral morphine equivalents had a significantly increased risk of POU.
POU is common after CIED procedures, and 12% of patients continued to use opioids >30 days after surgery. Higher initially prescribed oral morphine equivalent doses were associated with developing POU.
Targeting non-pulmonary vein triggers (NPVTs) after pulmonary vein isolation may reduce atrial fibrillation (AF) recurrence. Isoproterenol infusion and cardioversion of spontaneous or induced AF can ...provoke NPVTs but typically require vasopressor support and increased procedural time.
The purpose of this study was to identify risk factors for the presence of NPVTs and create a risk score to identify higher-risk subgroups.
Using the AF ablation registry at the Hospital of the University of Pennsylvania, we included consecutive patients who underwent AF ablation between January 2021 and December 2022. We excluded patients who did not receive NPVT provocation testing after failing to demonstrate spontaneous NPVTs. NPVTs were defined as non-pulmonary vein ectopic beats triggering AF or focal atrial tachycardia. We used risk factors associated with NPVTs with P <.1 in multivariable logistic regression model to create a risk score in a randomly split derivation set (80%) and tested its predictive accuracy in the validation set (20%).
In 1530 AF ablations included, NPVTs were observed in 235 (15.4%). In the derivation set, female sex (odds ratio OR 1.40; 95% confidence interval CI 0.96-2.03; P = .080), sinus node dysfunction (OR 1.67; 95% CI 0.98-2.87; P = .060), previous AF ablation (OR 2.50; 95% CI 1.70-3.65; P <.001), and left atrial scar (OR 2.90; 95% CI 1.94-4.36; P <.001) were risk factors associated with NPVTs. The risk score created from these risk factors (PRE
SSS
score; PREvious ablation: 2 points, female Sex: 1 point, Sinus node dysfunction: 1 point, left atrial Scar: 2 points) had good predictive accuracy in the validation cohort (area under the receiver operating characteristic curve 0.728; 95% CI 0.648-0.807).
A risk score incorporating predictors for NPVTs may allow provocation of triggers to be performed in patients with greatest expected yield.
Ventricular fibrillation (VF) can be initiated by ventricular premature depolarizations (VPDs) in the absence of obvious structural abnormalities.
The purpose of this study was to determine the ...prevalence of 12-lead electrocardiographic (ECG) sinus rhythm reduced QRS amplitude, QRS fractionation (QRSf), and early repolarization (ER) pattern, and the outcome of catheter ablation and VPD anatomic distribution in patients with VPDs initiating VF.
We compared a cohort with no apparent structural heart disease and VPDs initiating VF (group 1; n = 42) to a reference cohort (group 2; n = 61) of patients with no structural heart disease and symptomatic unifocal VPDs.
A reduced QRS amplitude (<0.55 mV) in aVF (59% vs 10%; P <.001), QRSf in ≥2 contiguous leads (50% vs 16%; P <.001), and ER pattern (21.4% vs 1.6%; P = .01) were more common in group 1 than in group 2. At least 1 abnormal ECG finding was present in 34 group 1 patients (81%) vs 17 group 2 patients (28%) (P <.001). VPD origin included right ventricular and left ventricular distal Purkinje system and moderator band/papillary muscles in 83% of group 1 patients vs 18% of group 2 patients (P <.001). VF was eliminated with a single ablation procedure in 77% of group 1 patients with at least 2 years of follow-up.
A reduced QRS amplitude (<0.55 mV) in aVF, QRSf in ≥2 contiguous leads, and/or an ER pattern are frequently observed in patients with VPDs initiating VF. VPDs initiating VF typically originate from the distal Purkinje system and papillary muscles and can be successfully eliminated with catheter ablation.
Context: The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) cohort represents the largest and best-characterized national sample of American youth with recent-onset type 2 ...diabetes.
Objective: The objective of the study was to describe the baseline characteristics of participants in the TODAY randomized clinical trial.
Design: Participants were recruited over 4 yr at 15 clinical centers in the United States (n = 704) and enrolled, randomized, treated, and followed up 2–6 yr.
Setting: The study was conducted at pediatric diabetes care clinics and practices.
Participants: Eligible participants were aged 10–17 yr inclusive, diagnosed with type 2 diabetes for less than 2 yr and had a body mass index at the 85th percentile or greater.
Interventions: After baseline data collection, participants were randomized to one of the folllowing groups: 1) metformin alone, 2) metformin plus rosiglitazone, or 3) metformin plus a lifestyle program of weight management.
Main Outcome Measures: Baseline data presented include demographics, clinical/medical history, biochemical measurements, and clinical and biochemical abnormalities.
Results: At baseline the cohort included the following: 64.9% were female; mean age was 14.0 yr; mean diabetes duration was 7.8 months; mean body mass index Z-score was 2.15; 89.4% had a family history of diabetes; 41.1% were Hispanic, 31.5% were non-Hispanic black; 38.8% were living with both biological parents; 41.5% had a household annual income of less than $25,000; 26.3% had a highest education level of parent/guardian less than a high school degree; 26.3% had a blood pressure at the 90th percentile or greater; 13.6% had a blood pressure at the 95th percentile or greater; 13.0% had microalbuminuria; 79.8% had a low high-density lipoprotein level; and 10.2% had high triglycerides.
Conclusions: The TODAY cohort is predominantly from racial/ethnic minority groups, with low socioeconomic status and a family history of diabetes. Clinical and biochemical abnormalities and comorbidities are prevalent within 2 yr of diagnosis. These findings contribute greatly to our understanding of American youth with type 2 diabetes.
The TODAY cohort, representing the largest and best-characterized national sample of American youth with type 2 diabetes, is described at baseline.
Bioenergy plants with carbon capture and storage have been recently receiving attention as negative emission technologies. In this work, a techno-economic analysis of bio-methanol and bio-hydrogen ...production plants coupled with carbon capture and storage is conducted. The plants include different gasification technologies (direct oxygen-blown gasification and indirect gasification) and different CO
2
capture processes (pre-combustion MDEA-based and post-combustion MEA-based CO
2
capture) from different streams, to achieve increasing CO
2
capture rates at increasing marginal costs. Moreover, an assessment of the economic impact of multi-product plants which flexibly produce methanol and hydrogen is carried out. Overall fuel production efficiencies of between 65.1 and 68.1% have been computed in all cases, showing a little dependency of energy efficiency on the gasification technology and the final product. In methanol production plants, a CO
2
capture rate of between 26 and 55%, depending on the gasification technology, can be reached
via
a pre-combustion capture process at a cost of 41-46 € per t
CO
2
. In hydrogen production plants, between 64 and 90% capture efficiency can be reached at a cost of 52-56 € per t
CO
2
. Higher CO
2
capture efficiency, resulting in CO
2
residual emissions below 2% of the inlet carbon, can be achieved
via
post-combustion capture with a marginal cost of 98-205 € per t
CO
2
and an average cost of 47-77 € per t
CO
2
. Flexible methanol-H
2
production plants result in the highest capex and the highest LCOF. However, when considering the time-dependent H
2
market price, the internal rate of return of flexible methanol-H
2
plants is slightly higher or slightly lower than that of the corresponding best single-product plant. On the other hand, multi-product flexible plants are never the worst case scenario despite the highest investment costs, thus offering a potential advantage from the financial risk perspective thanks to lower exposure to market price volatility.
Multi-product plants with CCS maximize carbon utilization and may obtain economic advantages from flexible production of H
2
and methanol.
Background
The use of a multi-electrode Optrell mapping catheter during ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation procedures has not been widely reported.
...Objectives
We aim to describe the feasibility and safety of using the Optrell multipolar mapping catheter (MPMC) to guide catheter ablation of VT and PVCs.
Methods
We conducted a single-center, retrospective evaluation of patients who underwent VT or PVC ablation between June and November 2022 utilizing the MPMC.
Results
A total of 20 patients met the inclusion criteria (13 VT and 7 PVC ablations, 80% male, 61 ± 15 years). High-density mapping was performed in the VT procedures with median 2753 points IQR 1471–17,024 collected in the endocardium and 12,830 points IQR 2319–30,010 in the epicardium. Operators noted challenges in manipulation of the MPMC in trabeculated endocardial regions or near valve apparatus. Late potentials (LPs) were detected in 11 cases, 7 of which had evidence of isochronal crowding demonstrated during late annotation mapping. Two patients who also underwent entrainment mapping had critical circuitry confirmed in regions of isochronal crowding. In the PVC group, high-density voltage and activation mapping was performed with a median 1058 points IQR 534–3582 collected in the endocardium.
Conclusions
This novel MPMC can be used safely and effectively to create high-density maps in LV endocardium or epicardium. Limitations of the catheter include a longer wait time for matrix formation prior to starting point collection and challenges in manipulation in certain regions.
Background
There is growing interest in the possibility of discontinuing oral anticoagulation following successful catheter ablation of atrial fibrillation (AF). However, it remains unknown whether ...patients can accurately detect arrhythmia recurrences following ablation. We therefore sought to characterize the accuracy of pulse checking and arrhythmia symptoms for the identification of AF following ablation.
Methods
This prospective cohort study included patients at the Hospital of the University of Pennsylvania with an insertable cardiac monitor (ICM) treated with catheter ablation for AF who recorded the results from minimum twice daily pulse checks and additionally with arrhythmia symptoms into a diary for 2 months following their procedure. Accuracy of this self-assessment protocol was determined by comparison to ICM-detected AF.
Results
A total of 55 patients (age 69 ± 8 years, 30 (55%) male, CHA
2
DS
2
VASc score 3.2 ± 1. 5) were included. Patients recorded a total of 5911 pulse checks, and there were 280 episodes of ICM-documented AF among 26 patients with an average duration of 2.5 ± 3.3 h. Among 362 episodes of patient-suspected AF, 134 correlated with ICM-identified AF (37% true positive rate). Of the 5549 pulse checks that did not identify AF, 196 correlated with ICM-identified AF (4% false negative rate). Twice daily pulse checking had a sensitivity of 47% and a specificity of 96% for identifying each episode of AF.
Conclusions
Our data indicate that a strategy of pulse checks and symptom assessment is insufficient to identify all episodes of AF in many patients following catheter ablation.
PDF
