A Low-Cost Filament Winding Technology for University Laboratories and Startups.

This paper systematically explains the methodology and results of empirical work on the development of a low-cost filament winding technology for manufacturing axisymmetric polymer composite structures with a high length-to-diameter ratio, such as tubes, motor casings, and pressure vessels. The principal objective was to examine the experiences and most optimal practices in the development of computer-controlled equipment and auxiliary tooling for the wet filament-winding process. To preclude expensive commercial software for the automated control of a winding machine, analytical equations were derived for the winding trajectory of a four-axis filament-winding machine. The feasibility of the proposed equations was successfully validated by laying the fiber along the geodesic path marked on the surface of a cylindrical mandrel with hemispherical ends. Moreover, the carbon/epoxy cylindrical casings with hemispherical ends and port openings of the same diameter were wound to determine the thickness distribution in the hemispherical dome. The fiber volume ratio in the wound composite parts was evaluated using an optical technique.

Chronic use of renin-angiotensin-aldosterone inhibitors in hypertensive COVID-19 patients: Results from a Spanish registry and meta-analysis.

Background: Hypertension is a prevalent condition among SARS-CoV-2 infected patients. Whether renin-angiotensin-aldosterone system (RAAS) inhibitors are beneficial or harmful is controversial. Methods: We have performed a national retrospective, nonexperimental comparative study from two tertiary hospitals to evaluate the impact of chronic use of RAAS inhibitors in hypertensive COVID-19 patients. A meta-analysis was performed to strengthen our findings. Results: Of 849 patients, 422 (49.7%) patients were hypertensive and 310 (73.5%) were taking RAAS inhibitors at baseline. Hypertensive patients were older, had more comorbidities, and a greater incidence of respiratory failure (-0.151 [95% CI -0.218, -0.084]). Overall mortality in hypertensive patients was 28.4%, but smaller among those with prescribed RAAS inhibitors before (-0.167 [95% CI -0.220, -0.114]) and during hospitalization (0.090 [-0.008,0.188]). Similar findings were observed after two propensity score matches that evaluated the benefit of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers among hypertensive patients. Multivariate logistic regression analysis of hypertensive patients found that age, diabetes mellitus, C-reactive protein, and renal failure were independently associated with all-cause mortality. On the contrary, ACEIs decreased the risk of death (OR 0.444 [95% CI 0.224-0.881]). Meta-analysis suggested a protective benefit of RAAS inhibitors (OR 0.6 [95% CI 0.42-0.8]) among hypertensive COVID-19. Conclusion: Our data suggest that RAAS inhibitors may play a protective role in hypertensive COVID-19 patients. This finding was supported by a meta-analysis of the current evidence. Maintaining these medications during hospital stay may not negatively affect COVID-19 outcomes.

Introducción: La hipertensión es una condición prevalente entre los pacientes infectados por el SARS-CoV-2. Es controvertido si los inhibidores del sistema renina-angiotensina-aldosterona (SRAA) son beneficiosos o perjudiciales. Métodos: Hemos desarrollado un estudio comparativo nacional retrospectivo y no experimental en 2 hospitales terciarios para evaluar el impacto del uso crónico de inhibidores del SRAA en pacientes hipertensos con COVID-19. Se realizó un metaanálisis para reforzar los hallazgos. Resultados: De 849 pacientes, 422 (49,7%) eran hipertensos y 310 (73,5%) tomaban inhibidores del SRAA al inicio del estudio. Los pacientes hipertensos eran mayores, tenían más comorbilidades y una mayor incidencia de insuficiencia respiratoria (−0,151; IC 95%: [−0,218; −0,084]). La mortalidad global en los pacientes hipertensos fue del 28,4%, pero fue menor entre los que tenían prescritos inhibidores del SRAA antes (−0,167; IC 95%: [−0,220; −0,114]) y durante la hospitalización (0,090; [−0,008; 0,188]). Se observaron hallazgos similares tras 2 emparejamientos de puntuación de propensión que evaluaron el beneficio de los inhibidores de la enzima convertidora de angiotensina y los bloqueadores de los receptores de angiotensina entre los pacientes hipertensos. El análisis de regresión logística multivariante de los pacientes hipertensos reveló que la edad, la diabetes mellitus, la proteína C reactiva y la insuficiencia renal se asociaban de forma independiente con la mortalidad por todas las causas. Por el contrario, los inhibidores de la enzima convertidora de angiotensina disminuyeron el riesgo de muerte (OR 0,444; IC 95%: 0,224-0,881). El metaanálisis indicó un beneficio protector de los inhibidores del SRAA (OR 0,6; IC 95%: 0,42-0,8) entre los hipertensos con COVID-19. Conclusión: Nuestros datos indican que los inhibidores del SRAA pueden desempeñar un papel protector en los pacientes hipertensos con COVID-19. Este hallazgo fue apoyado por un metaanálisis de la evidencia actual. Su mantenimiento durante la estancia hospitalaria puede no afectar negativamente a los resultados de la COVID-19.

Chronic use of renin-angiotensin-aldosterone inhibitors in hypertensive COVID-19 patients: Results from a Spanish registry and meta-analysis.

BACKGROUND: Hypertension is a prevalent condition among SARS-CoV-2 infected patients. Whether renin-angiotensin-aldosterone system (RAAS) inhibitors are beneficial or harmful is controversial. METHODS: We have performed a national retrospective, nonexperimental comparative study from two tertiary hospitals to evaluate the impact of chronic use of RAAS inhibitors in hypertensive COVID-19 patients. A meta-analysis was performed to strengthen our findings. RESULTS: Of 849 patients, 422 (49.7%) patients were hypertensive and 310 (73.5%) were taking RAAS inhibitors at baseline. Hypertensive patients were older, had more comorbidities, and a greater incidence of respiratory failure (-0.151 [95% CI -0.218, -0.084]). Overall mortality in hypertensive patients was 28.4%, but smaller among those with prescribed RAAS inhibitors before (-0.167 [95% CI -0.220, -0.114]) and during hospitalization (0.090 [-0.008,0.188]). Similar findings were observed after two propensity score matches that evaluated the benefit of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers among hypertensive patients. Multivariate logistic regression analysis of hypertensive patients found that age, diabetes mellitus, C-reactive protein, and renal failure were independently associated with all-cause mortality. On the contrary, ACEIs decreased the risk of death (OR 0.444 [95% CI 0.224-0.881]). Meta-analysis suggested a protective benefit of RAAS inhibitors (OR 0.6 [95% CI 0.42-0.8]) among hypertensive COVID-19. CONCLUSION: Our data suggest that RAAS inhibitors may play a protective role in hypertensive COVID-19 patients. This finding was supported by a meta-analysis of the current evidence. Maintaining these medications during hospital stay may not negatively affect COVID-19 outcomes.

Impact of renin-angiotensin system inhibitors on outcomes after surgical or transcatheter aortic valve replacement. A meta-analysis.

INTRODUCTION AND OBJECTIVES: To determine whether renin-angiotensin system inhibitor (RASi) prescription is associated with better outcomes after transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). METHODS: All comparative studies of RASi vs no RASi prescription in patients undergoing TAVI/SAVR were gathered from PubMed, Web of Science, and Google Scholar through August, 2019. We extracted hazard ratios (HRs) with their confidence intervals (CIs) for mortality from each study and combined study-specific estimates using inverse variance-weighted averages of logarithmic HRs in the random effects model. RESULTS: We identified 6 eligible studies with a total of 21 390 patients (TAVI: 17 846; SAVR: 3544) and included them in the present meta-analysis. The 6 studies were observational comparative studies (including 3 propensity score matched and 3 cohort studies) of RASi vs no RASi prescription. The analysis demonstrated that RASi prescription was associated with significantly lower mortality in the whole group of patients undergoing aortic valve intervention (HR, 0.64; 95%CI, 0.47-0.88; P <.001). However, subgroup analysis suggested differences according to the selected therapy, with TAVI showing better mortality rates in the RASi group (HR, 0.67; 95%CI, 0.49-0.93) but not in the SAVR group (HR, 0.61; 95%CI, 0.29-1.30). No funnel plot asymmetry was identified, suggesting minimum publication bias. Sensitivity analyses sequentially eliminating dissimilar studies did not substantially alter the primary result favoring RASI prescription. CONCLUSIONS: These findings suggest a mortality benefit of RASi in patients with AS treated with aortic valve replacement that might be particularly relevant following TAVI. Future randomized studies are warranted to confirm this relevant finding.

Atrial fibrillation in patients with SARS-CoV-2 infection.

INTRODUCTION AND OBJECTIVE: the SARS-CoV-2 infection ranges from asymptomatic to critical forms and several prognostic factors have been described. Atrial fibrillation (AF) is common in acute situations where it is linked with more complications and mortality. We aimed to evaluate the prognostic information of AF in this population. METHODS: retrospective analysis of a cohort of 517 patients consecutively admitted in a tertiary hospital due to SARS-CoV-2 infection. We divided the patients in two groups according the development of AF and compared the main features of both groups. An univariable and multivariable analysis of mortality were also performed. RESULTS: among 517 patients with SARS-CoV-2 infection admitted in a tertiary center, 54 (10.4%) developed AF. These patients are older (81.6 vs 66.5 years old, p<0.001) and present more hypertension (74% vs 47%, p<0.001), cardiomyopathy (9% vs 1%, p=0.002), previous heart failure admission (9% vs 0.4%, p<0.001), previous episodes of AF (83% vs 1%, p<0.001) and bigger left atrium (47.8 vs 39.9mm, p<0.001). AF COVID-19 patients present more acute respiratory failure (72% vs 40%, p<0.001) and higher in-hospital mortality (50% vs 22%, p<0.001). Predictors of AF development are age and previous AF. AF is not an independent predictor of in-hospital mortality. Predictors are age, creatinine>1.5mg/dL at admission, LDH>250UI/L at admission and acute respiratory failure. CONCLUSION: Atrial fibrillation appears in 10% of hospitalized patients with SARS-CoV-2 infection. These patients present more comorbidities and two-fold increase in hospital mortality. Atrial fibrillation is not an independent prognostic factor.

Atrial fibrillation in patients with SARS-CoV-2 infection.

INTRODUCTION AND OBJECTIVE: the SARS-CoV-2 infection ranges from asymptomatic to critical forms and several prognostic factors have been described. Atrial fibrillation (AF) is common in acute situations where it is linked with more complications and mortality. We aimed to evaluate the prognostic information of AF in this population. METHODS: retrospective analysis of a cohort of 517 patients consecutively admitted in a tertiary hospital due to SARS-CoV-2 infection. We divided the patients in two groups according the development of AF and compared the main features of both groups. An univariable and multivariable analysis of mortality were also performed. RESULTS: among 517 patients with SARS-CoV-2 infection admitted in a tertiary center, 54 (10.4%) developed AF. These patients are older (81.6 vs 66.5 years old, p < 0.001) and present more hypertension (74% vs 47%, p < 0.001), cardiomyopathy (9% vs 1%, p = 0.002), previous heart failure admission (9% vs 0.4%, p < 0.001), previous episodes of AF (83% vs 1%, p < 0.001) and bigger left atrium (47.8 vs 39.9 mm, p < 0.001). AF COVID-19 patients present more acute respiratory failure (72% vs 40%, p < 0.001) and higher in-hospital mortality (50% vs 22%, p < 0.001). Predictors of AF development are age and previous AF. AF is not an independent predictor of in-hospital mortality. Predictors are age, creatinine > 1.5 mg/dL at admission, LDH > 250 UI/L at admission and acute respiratory failure. CONCLUSION: Atrial fibrillation appears in 10% of hospitalized patients with SARS-CoV-2 infection. These patients present more comorbidities and two-fold increase in hospital mortality. Atrial fibrillation is not an independent prognostic factor.

INTRODUCCIÓN Y OBJETIVO: La infección por SARS-CoV-2 presenta un amplio espectro clínico, y varios factores pronósticos han sido descritos. La fibrilación auricular (FA) es frecuente en situaciones agudas, donde se ha relacionado con aumento de complicaciones y mortalidad. Nuestro objetivo ha sido evaluar el impacto pronóstico de la FA en esta población. MÉTODOS: Análisis retrospectivo de una cohorte de 517 pacientes con infección SARS-CoV-2 consecutivamente ingresados en un hospital terciario. Dividimos a los pacientes en dos grupos de acuerdo al desarrollo de FA durante el ingreso y comparamos las características de los grupos. Realizamos análisis univariado y multivariado de mortalidad. RESULTADOS: De los 517 pacientes, 54 (10,4%) desarrollaron FA. Estos pacientes son mayores (81,6 vs. 66,5 años, p < 0,001) y presentan más hipertensión (74% vs. 47%, p < 0,001), miocardiopatía (9% vs. 1%, p = 0,002), ingreso previo por insuficiencia cardiaca (9% vs. 0,4%, p < 0,001), historia de FA (83% vs. 1%, p < 0,001) y mayor aurícula izquierda (47,8 vs. 39,9 mm, p < 0,001). Los pacientes con FA presentan más fallo respiratorio agudo (72% vs. 40%, p < 0,001) y mayor mortalidad hospitalaria (50% vs. 22%, p < 0,001). Los predictores de FA son la edad y la historia de FA previa. La FA no es un predictor independiente de mortalidad hospitalaria. Los predictores son: edad, creatinina > 1,5 mg/dL al ingreso, LDH > 250 U/L al ingreso y el fallo respiratorio agudo. CONCLUSIÓN: La FA aparece en el 10% de los pacientes hospitalizados por SARS-CoV-2. Estos presentan mayor comorbilidad y el doble de mortalidad hospitalaria, pero la FA no es un factor pronóstico independiente.

The COVID-19 lab score: an accurate dynamic tool to predict in-hospital outcomes in COVID-19 patients.

Deterioration is sometimes unexpected in SARS-CoV2 infection. The aim of our study is to establish laboratory predictors of mortality in COVID-19 disease which can help to identify high risk patients. All patients admitted to hospital due to Covid-19 disease were included. Laboratory biomarkers that contributed with significant predictive value for predicting mortality to the clinical model were included. Cut-off points were established, and finally a risk score was built. 893 patients were included. Median age was 68.2 ± 15.2 years. 87(9.7%) were admitted to Intensive Care Unit (ICU) and 72(8.1%) needed mechanical ventilation support. 171(19.1%) patients died. A Covid-19 Lab score ranging from 0 to 30 points was calculated on the basis of a multivariate logistic regression model in order to predict mortality with a weighted score that included haemoglobin, erythrocytes, leukocytes, neutrophils, lymphocytes, creatinine, C-reactive protein, interleukin-6, procalcitonin, lactate dehydrogenase (LDH), and D-dimer. Three groups were established. Low mortality risk group under 12 points, 12 to 18 were included as moderate risk, and high risk group were those with 19 or more points. Low risk group as reference, moderate and high patients showed mortality OR 4.75(CI95% 2.60-8.68) and 23.86(CI 95% 13.61-41.84), respectively. C-statistic was 0-85(0.82-0.88) and Hosmer-Lemeshow p-value 0.63. Covid-19 Lab score can very easily predict mortality in patients at any moment during admission secondary to SARS-CoV2 infection. It is a simple and dynamic score, and it can be very easily replicated. It could help physicians to identify high risk patients to foresee clinical deterioration.

Impact of the presence of heart disease, cardiovascular medications and cardiac events on outcome in COVID-19.

BACKGROUND: Cardiovascular risk factors and usage of cardiovascular medication are prevalent among coronavirus disease 2019 (COVID-19) patients. Little is known about the cardiovascular implications of COVID-19. The goal herein, was to evaluate the prognostic impact of having heart disease (HD) and taking cardiovascular medications in a population diagnosed of COVID-19 who required hospitalization. Also, we studied the development of cardiovascular events during hospitalization. METHODS: Consecutive patients with definitive diagnosis of COVID-19 made by a positive real time- -polymerase chain reaction of nasopharyngeal swabs who were admitted to the hospital from March 15 to April 14 were included in a retrospective registry. The association of HD with mortality and with mortality or respiratory failure were the primary and secondary objectives, respectively. RESULTS: A total of 859 patients were included in the present analysis. Cardiovascular risk factors were related to death, particularly diabetes mellitus (hazard ratio in the multivariate analysis: 1.810 [1.159- -2.827], p = 0.009). A total of 113 (13.1%) patients had HD. The presence of HD identified a group of patients with higher mortality (35.4% vs. 18.2%, p < 0.001) but HD was not independently related to prognosis; renin-angiotensin-aldosterone system inhibitors, calcium channel blockers, diuretics and beta-blockers did not worsen prognosis. Statins were independently associated with decreased mortality (0.551 [0.329-0.921], p = 0.023). Cardiovascular events during hospitalization identified a group of patients with poor outcome (mortality 31.8% vs. 19.3% without cardiovascular events, p = 0.007). CONCLUSIONS: The presence of HD is related to higher mortality. Cardiovascular medications taken before admission are not harmful, statins being protective. The development of cardiovascular events during the course of the disease is related to poor outcome.

Charcoal production from waste pequi seeds for heat and power generation.

Many specialized technologies are available to convert waste biomass into secondary products that have a higher value and are more convenient to process than the original feedstock. This study evaluated the potential of waste pequi seeds to produce high-quality charcoal for subsequent gasification into low-tar producer gas for heat engine applications. We focused on the characterization of pequi seeds, the derived charcoal, and the collected bio-oil from slow pyrolysis conversion of the feedstock. Thermodynamic equilibrium calculations were conducted to assess gasification performance of the parent biomass and its charcoal. We also investigated the thermal degradation kinetics of pequi seeds through non-isothermal thermogravimetric analysis. Finally, a two-step energy-extraction analysis was performed for the carbonization of the parent biomass and further utilization of its charcoal in an integrated gasification gas-engine cycle. Slow pyrolysis of pequi seeds (2 °C min-1, 430 °C) produced up to 40% of high-grade charcoal with 60% fixed carbon, 43% of bio-oil, and 16% of light gases. The overall energy extraction efficiency was estimated as 61%, based on the higher heating value of wet pequi seeds. The investigation confirmed that waste pequi seeds could be considered a promising renewable energy source for combined heat and power generation for the Brazilian agro-food industry.

Exercise right heart catheterization predicts outcome in asymptomatic degenerative aortic stenosis.

INTRODUCTION AND OBJECTIVES: Degenerative aortic stenosis (DAS) is the most frequent valvular heart disease. It remains unclear how to identify asymptomatic DAS patients with normal left ventricular ejection fraction who have a high probability of event occurrence and would thus benefit from early intervention. Here, we describe a protocol for exercise hemodynamics in true asymptomatic patients with moderate or severe DAS and assess the prognostic value of the data obtained in this population. METHODS: This study involved a prospective single-centre registry of consecutive asymptomatic patients with moderate or severe DAS. Patients underwent cardiopulmonary exercise testing to confirm symptom absence during exercise and then right heart catheterization (RHC) at rest and during exercise. Events were defined as death, surgical aortic valve replacement, or transcatheter aortic valve implantation according to clinical guidelines. RESULTS: Thirty-three patients underwent baseline and exercise RHC. The mean aortic valve area was 1.08 cm2 and the aortic gradient was 39mmHg. The mean pulmonary artery pressure was 21mmHg with a pulmonary artery occlusion pressure of 14mmHg and cardiac output of 5.6 L/min. The mean pulmonary artery pressure at peak exercise was 34mmHg. After a mean follow-up of 27 months, 8 patients experienced an event (24%). There were no differences in baseline variables, aortic valve area, or cardiopulmonary exercise testing parameters between the event and event-free groups. Patients with an event did not have higher pulmonary or filling pressures after peak exercise but had lower pulmonary artery oxygen saturation on effort (median, 48% vs 57%, P=.03). CONCLUSIONS: Exercise RHC is feasible and safe in this population. Peak pulmonary artery oxygen saturation might identify patients with increased risk of serious adverse events.