Search

Annual arrhythmic sudden cardiac death ranges from 0.6% to 4% in ischemic cardiomyopathy (ICM), 1% to 2% in non-ischemic cardiomyopathy (NICM), and 1% in hypertrophic cardiomyopathy (HCM). Towards a more effective arrhythmic risk stratification (ARS) we hereby present a two-step ARS with the usage of seven non-invasive risk factors: Late potentials presence (≥ 2/3 positive criteria), premature ventricular contractions (≥ 30/h), non-sustained ventricular tachycardia (≥ 1episode/24 h), abnormal heart rate turbulence (onset ≥ 0% and slope ≤ 2.5 ms) and reduced deceleration capacity (≤ 4.5 ms), abnormal T wave alternans (≥ 65μV), decreased heart rate variability (SDNN < 70ms), and prolonged QTc interval (> 440 ms in males and > 450 ms in females) which reflect the arrhythmogenic mechanisms for the selection of the intermediate arrhythmic risk patients in the first step. In the second step, these intermediate-risk patients undergo a programmed ventricular stimulation (PVS) for the detection of inducible, truly high-risk ICM and NICM patients, who will benefit from an implantable cardioverter defibrillator. For HCM patients, we also suggest the incorporation of the PVS either for the low HCM Risk-score patients or for the patients with one traditional risk factor in order to improve the inadequate sensitivity of the former and the low specificity of the latter. © 2022 Baishideng Publishing Group Co. All rights reserved.

Background: Significant sinus bradycardia (SB) in the context of sinus node dysfunction (SND) has been associated with neurological symptoms. The objective was to evaluate the effect of permanent pacing on the incidence of syncope in patients with rather mild degrees of SB, unexplained syncope, and “positive” invasive electrophysiologic testing. Methods: This was an observational study based on a prospective registry of 122 consecutive mild SB patients (61.90 ± 18.28 years, 61.5% male, 57.88 ± 7.73 bpm) presenting with recurrent unexplained pre and syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). Τhe implantation of a permanent antibradycardia pacemaker (ABP) was offered to all patients according to the results of the EPS. Eighty patients received the ABP, while 42 denied. Results: The mean of reported syncope episodes was 2.23 ± 1.29 (or presyncope 2.36 ± 1.20) in the last 12 months before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (50.39 ± 32.40 months), the primary outcome event (syncope) occurred in 18 of 122 patients (14.8%), 6 of 80 (7.5%) in the ABP group as compared to 12 of 42 (28.6%) in the no pacemaker group (P =.002). Conclusions: Among patients with mild degree of SB and a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined SND after differentiating reflex syncope, identifies a subset of patients who will benefit from permanent pacing. © 2020 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society

Biomethanation of biomass-derived syngas is a promising renewable methane production technology with high carbon efficiency, but there is lack of evidence on how process scale-up and biomass cost impact the profitability of full-scale processes. In this study, we developed a set of techno-economic models for the assessment of process competitiveness under several scales and configurations, integrating syngas biomethanation with Power-to-Gas (PtG) services, carbon capture and storage (CCS) and biomethane liquefaction. The results indicate that the incentive mechanism currently supporting biomethane production from anaerobic digestion in Italy would grant profitability for small-scale (6 MWth input) syngas biomethanation plants at biomass costs equal to or below 80 €/t. Under the Danish mechanism, such biomass cost corresponds to 60 €/t. At the currently valid biomass cost of 150 €/t, an 8-MW system delivers a minimum selling price (MSP) of 1.07 €/Nm3 biomethane, but such MSP increases substantially when PtG and CCS are included., Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 1-7

Background: Sudden cardiac death (SCD) risk stratification in hypertrophic cardiomyopathy (HCM) in the context of primary prevention remains suboptimal. The purpose of this study was to examine the additional contribution of programmed ventricular stimulation (PVS) on established risk assessment. Methods: Two-hundred-and-three consecutive patients with diagnosed HCM and ≥ 1 noninvasive risk factors were prospectively enrolled over 19 years. Patients were risk stratified, submitted to PVS and received an implantable cardioverter-defibrillator (ICD) according to then-current American Heart Association (AHA) guidelines and inducibility. Participants were prospectively followed-up for primary endpoint occurrence (appropriate ICD therapy or SCD). Contemporary (2015) AHA and European Society of Cardiology (ESC) guidelines were retrospectively assessed. Results: During a median follow-up period of 60 months the primary endpoint occurred in 20 patients, 19 of whom were inducible and received an ICD. Overall, 79 patients (38.9%) were inducible and 92 patients (45.3%) received an ICD (PVS sensitivity = 95%, specificity = 67.2%, positive predictive value = 24%, negative predictive value = 99.2%). AHA and ESC guidelines application misclassified 3 and 9 primary endpoint-meeting patients, respectively. Inducibility was the most important determinant of event-free survival in multivariate Cox regression (hazard ratio = 33.3). A combined approach of ESC score ≥ 6% or AHA indication for ICD with PVS inducibility yielded absolute sensitivity and negative predictive value, the former at a more cost-effective and specific way. Conclusions: Inducibility at PVS predicts SCD or appropriate device therapy in HCM. Non-inducibility is associated with prolonged event-free survival, while the procedure was proven safe. Reintegration of PVS into established risk stratification models in HCM may improve patient assessment. © 2017 Elsevier Ireland Ltd

Syngas fermentation is one of the most promising approaches among second generation biofuel technologies due to the benefits derived from the combination of thermochemical and biochemical conversion processes. In this process, a wide array of feedstocks of different nature can be converted through gasification into synthesis gas, composed by mainly H2, CO and CO2, which can be further converted biologically into both gaseous and liquid biofuels. The fermentation of synthesis gas has been typically carried out by pure cultures. However, using open mixed cultures and taking thus advantage of their inherent microbial diversity may offer a series of benefits such as high adaptive capacity, resilience to syngas impurities and non-sterile operation [1][2]. All the above may contribute to reducing utility consumption. On the other hand, a poor understanding of the microbial interactions within microbial consortia usually leads to low product selectivity in fermentation processes. Thus, gaining a better control on the activity of microbial consortia is fundamental for the further development of mixed microbial consortia fermentations.In this work, a number of enrichment strategies were designed for enhancing the microbial activity of anaerobic sludge towards the production of methane and ethanol. The methanogenic potential of the anaerobic sludge was assessed through enrichments at different temperatures, developing a mesophilic (37˚C) and a thermophilic (60˚C) methanogenic consortium. The ethanologenic potential of the anaerobic sludge was evaluated based on enrichments at different initial pH conditions (6, 5.5 and 5).The results showed that the enrichments led to less complex microbial consortia with a higher microbial activity towards the targeted products. The study of the behaviour of the methanogenic enriched consortia revealed different patterns of activity and inhibition between the mesophilic and the thermophilic consortia, obtaining a methane yield at the end of the enrichments of 81.4% and 92.6% of the theoretical maximum, respectively. In turn, the ethanologenic potential of the enriched consortia was observed to increase as the initial pH was lowered, achieving a maximum ethanol yield of 17.7%, 33.3% and 59.8% of the theoretical maximum in enrichments at pH 6, 5.5 and 5, respectively.Overall, controlling the operational conditions of the enrichments enhanced both the product yields and the activity of certain catabolic routes towards methane and ethanol. This allowed increasing significantly the overall conversion rate in methanogenic enrichments as well as the product selectivity in ethanologenic enrichments.

Over the last decades, the development of second generation biofuel technologies have been posed as a necessity due to the increasing energy demand in the transportation sector and the rising concerns about the climate change. Common approaches for the production of second generation biofuels involve the conversion of recalcitrant biomasses via either biochemical or thermochemical methods such as biomass pretreatment and fermentation of carbohydrates, and biomass gasification coupled to Fischer-Tropsch (FT) processes. Syngas fermentation has also been proposed as a promising alternative to the aforementioned technologies as it presents higher biomass conversion efficiency compared to biochemical methods, and lower operational costs when compared to FT processes.1The fermentation of syngas into ethanol has been mostly studied using pure cultures. Nevertheless, several acetogenic species have been reported to be partially inhibited by the impurities of raw syngas, which would increase the raw syngas cleaning requirements.2 A possible alternative to circumvent the additional gas clean-up step is using open mixed microbial consortia (MMC) as their inherent microbial diversity confers them with a higher resilience towards toxic compounds, thus reducing partial inhibition phenomena.3 Additionally, the fact that sterile operation is not required in MMC-based processes contributes to reducing the operational costs by minimizing the utility consumption. On the other hand, the microbial interactions prevailing within microbial communities are often poorly understood, which leads to a decreased performance in terms of yield and product selectivity.In order to overcome these limitations, this work focused on studying the effects of operational conditions on the enrichment of MMC for enhancing the product selectivity towards ethanol, as well as on studying the effects of operational parameters on the ethanol yield and productivity of a MMC-based continuous process using a 2 L stirred tank reactor. The results showed that the enrichments at different pH conditions had a strong effect on the microbial activity and the final ethanol yield in batch experiments, obtaining a maximum ethanol yield of 17.7%, 33.3% and 59.8% of the theoretical maximum at pH 6, 5.5 and 5, respectively. Further experiments in continuous mode showed that pH, HRT and gas loading rate are essential operational parameters governing microbial interactions within the microbial consortium, and consequently the ethanol yield and product distribution.

The fermentation of synthesis gas is a promising approach for the production of biofuels as it combines benefits derived from both thermochemical and biochemical conversion processes. In this process, a wide range of feedstocks can be converted through gasification into synthesis gas, a mixture of H2, CO and CO2, which can be further converted biologically into gaseous and liquid biofuels. The fermentation of synthesis gas has been typically studied using pure microbial cultures. However, open mixed cultures may offer a series of advantages over pure cultures such as high adaptive capacity, resilience to syngas impurities and non-sterile operation [1, 2]. On the other hand, the poor understanding of the microbial interactions in mixed cultures usually leads to low product selectivity in fermentation processes. Thus, gaining a better control on the activity of the whole microbial community is fundamental for the further development of mixed culture-based fermentations.In this work, a number of batch and continuous enrichment strategies were designed for enhancing the microbial activity of anaerobic sludge towards the production of methane and ethanol. The methanogenic potential of the anaerobic sludge was assessed through batch enrichments at different temperatures (37˚C and 60˚C). The ethanologenic potential of the anaerobic sludge was evaluated through batch enrichments at different initial pH conditions (6, 5.5 and 5) and through a continuous enrichment using a 2 L CSTR fermenter operated at pH 4.5, HRT of 5 days and a gas inflow rate of 10 mL/min. Subsequently, the effect of the HRT and the mass transfer on the distribution of fermentation products was studied.The results showed that the batch enrichments led to less complex microbial consortia with a higher activity towards the targeted products. At the end of the batch enrichments, the methane yield of the mesophilic and the thermophilic methanogenic consortia corresponded to 81.4% and 92.6% of the theoretical maximum, respectively. Additionally, the study of the specific activity on H2/CO2, CO and acetate of the methanogenic enriched consortia revealed different patterns of activity between the two methanogenic microbial consortia. The ethanol yield obtained using the different ethanologenic enriched consortia was observed to increase as the initial pH was lowered, achieving a maximum ethanol yield of 17.7%, 33.3% and 59.8% of the theoretical maximum in enrichments at pH 6, 5.5 and 5, respectively. Similarly, the enrichment in continuous mode promoted a higher ethanologenic activity compared to the initial anaerobic sludge used, and both HRT and mass transfer were shown to be influencing parameters on the distribution of fermentation products under operation in continuous mode.

Polyhydroxyalkanoates (PHA) are biopolymers produced as internal carbon storage in bacteria. They are a potential alternative to petroleum derived plastics, although their competitiveness is still limited by their productions costs. These could be lowered by the use of waste substrates - such as crude glycerol, a major by-product of the biodiesel industry- and microbial mixed cultures - which do not require sterilisation 1.An important limitation for the PHA production from glycerol is the side accumulation of glycogen, a polymer with no market value. This can be circumvented by submitting first the substrate to anaerobic fermentation to produce volatile fatty acids (VFA), which are preferred substrates for PHA production2. However, the fermentation also leads to 1,3-propanediol (1,3-PDO), a compound not previously described for PHA production.Initial experiments aimed at the transformation of both VFA and 1,3-PDO to PHA. Using the classical feast-famine enrichment strategy, PHA production from 1,3-PDO was not observed. Conversely, the transformation was achieved by using a new strategy that limited the nitrogen during the feast phase. Nevertheless, the PHA yield obtained form 1,3-PDO was very low compared to the one obtained from VFA (0.24 vs 0.74 Cmol PHA/Cmol S).Given that 1,3-PDO is also a high value product, a third enrichment strategy was applied where only VFA were converted into PHA (up to 70% of the cells dry matter with a yield of 0.9 Cmol PHA/Cmol S) and 1,3-PDO was recovered from the process (97% recovery) in a biorefinery scheme. This strategy, based on the development of substrate preferences in mixed cultures, has the potential of being applied in other downstream processes of biological conversions, where fermentation side-products could be transformed into a high value product (PHA).

The current increasing trend in worldwide gasification capacity anticipates that thermochemical biomass conversion methods will play a significant role in the transition to a future bio-based economy. However, the development of more efficient syngas conversion processes to produce biofuels and chemicals is still needed. In this context, the process of syngas biomethanation is currently being considered as an alternative to the catalytic syngas methanation process. This biological process presents a number of inherent benefits such as the use of inexpensive biocatalysts, milder conditions of operation and higher tolerance to the impurities of the raw syngas, which may result in a more cost-effective process [1]. Nevertheless, a thorough understanding of the biological processes that prevail during the biomethanation of syngas is fundamental for the control and optimization of this process.This work focuses on the study of methanogenic syngas-converting microbial consortia, with the ultimate objective of enhancing the efficiency of the biomethanation of syngas in terms of yield and rate of conversion. A series of enrichment experiments were performed in order to generate two different microbial consortia, one of them enriched at mesophilic conditions and the other at thermophilic conditions. Subsequently, these enriched consortia were kinetically characterized in order to study their patterns of activity and determine the main syntrophic interactions present in each of the consortia. The results showed a significant increase in the conversion efficiency of syngas by the enriched consortia due to the selection and adaptation of the most efficient microbial groups. The maximum methane yields obtained at the end of the enrichment corresponded to 82,4% and 92,7% of the stoichiometric yield for the mesophilic and the thermophilic consortium, respectively. Additionally, the kinetic studies revealed significant differences between the patterns of activity of the mesophilic and the thermophilic consortia. Overall, the thermophilic consortium presented higher conversion rates along with a less complex microbial structure, both of which would ultimately favor a much higher methane productivity in a continuous syngas biomethanation process.

Aqueous ammonia soaking (AAS) and subsequent ammonia removal has been tested as a simple and cheap method to disrupt the lignocellulose and increase the methane potential and the biogas productivity of manure fibers. In the present study, mesophilic anaerobic digestion of AAS pretreated manure fibers was tested in CSTR­type digesters fed with swine manure and/or a mixture of swine manure and AAS pretreated manure fibers fibers. The Anaerobic Digestion Model No.1 (ADM1) was used to simulate a mesophilic reactor fed with swine manure and to predict the effect of addition of swine manure fibers pretreated with AAS. According to our results, the CH4 productivity of liquid manure could be easily increased to more than 30 m3/ton if the total solids content of the manure was increased to around 12% by addition of AAS­treated raw or digested fibers., Proceedings of the 21st European Biomass Conference and Exhibition, 3-7 June 2013, Copenhagen, Denmark, pp. 723-724

The present study focused on the impact of methicillin resistance of Staphylococcus aureus on cytokine production by monocytes. Cytokine stimulation was studied by 20 heat-killed isolates, 10 methicillin-susceptible Staphylococcus aureus (MSSA) and 10 methicillin-resistant Staphylococcus aureus (MRSA). Bacterial endocarditis was induced in 27 male rabbits by challenge with 1 MSSA isolate and 1 MRSA isolate. Blood was sampled for estimation of tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) and stimulation of monocytes. MSSA induced greater stimulation of TNF-α than MRSA, as shown after addition of a Toll-like receptor-4 (TLR4) antagonist. Survival of rabbits challenged by MRSA was prolonged compared to those challenged by MSSA. Serum MDA was greater after MSSA stimulation. Serum of animals challenged by MRSA stimulated greater release of interleukin (IL)-8 and IL-10 compared with MSSA: the opposite was observed for TNF-α. It is concluded that MSSA and MRSA induce a different pattern of TNF-α stimulation through a TLR4-independent mechanism, leading to shorter survival in experimental endocarditis. © 2012 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases.

The data regarding the role of serum uric acid (SUA) along with subclinical inflammation in the context of hypertensive vascular damage are rather scarce and controversial. Towards this end, we assess the links between SUA, high-sensitivity CRP (hs-CRP), adiponectin and carotid to femoral pulse wave velocity (c-f PWV) in 292 subjects with never-treated stage I-II essential hypertension. On the basis of the median SUA levels (0.31 mmol l -1), the study population was divided into subjects with low (n=149) and high (n=143) SUA values. By multiple regression analysis, it was revealed that SUA was independently associated with log hs-CRP (R 2 = 0.098; P=0.02), log adiponectin (R 2 = 0.102; P=0.03), waist circumference (R 2 = 0.049; P=0.04), 24-h systolic blood pressure (SBP) (R 2 = 0.179; P=0.001) and estimated glomerular filtration rate (R 2 = 0.156; β (s.e.)=-0.169 (0.023); P=0.02). In addition, c-f PWV was independently associated with age (R 2 = 0.116; P < 0.0001), waist circumference (R 2 = 0.088; P

The IEA Bioenergy Task 42 „Biorefineries“ made the following definition on biorefinery: “Biorefining is the sustainable processing of biomass into a spectrum of bio­based products (food, feed, chemicals, materials) and bioenergy (biofuels, power and/or heat)”. “Energy­driven” biorefineries and “product­driven” biorefineries are distinguished. Based on the ongoing activities in the 12 countries (A, AUS, CA, DK, FR, G, I, IR, NL, T, UK, US) participating in Task 42, the task identifies and assesses the current status and development potential of both “energy­driven” biorefineries (incl. biofuels) and “product­driven” biorefineries. These assessments are based on a “Full Value Chain approach”, covering raw material issues, conversion processes and final product applications in an integrated approach. As a first step the 15 most interesting “energy­driven” biorefinery concepts until 2020 and their value chains, including the integration and deployment options in existing industrial infrastructures, are analysed. These concepts produce the following transportation biofuels: biodiesel, bioethanol, FT­biofuels, biomethane from upgraded biogas and SNG (synthetic natural gas) with the following feedstocks: oil crops, oil residues, sugar and starch crops, wood chips, straw, grass, saw mill residues, (sulfite) liquor, algae. The Task 42 is assessing the sustainability of these concepts by analysing economic, environmental and social aspects in comparison to conventional processes and products., Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 1075-1079

We report a 31-year old woman with essential hypertension grade III and history of branch retinal vein occlusion in the setting of hyperhomocysteinemia due to homozygous MTHFR gene mutation and elevated Lp(a). The patient was treated successfully with antihypertensive treatment, acetylsalicylic acid and multivitamin complex supplementation. © 2008 Elsevier Ireland Ltd.