Search

Abstract: Ni and Co supported on SiO2 and Al2O3 silica cloth thin layer catalysts have been investigated in the catalytic decomposition of natural gas (CDNG) reaction. The influence of carrier nature and reaction temperature was evaluated with the aim to individuate the key factors affecting coke formation. Both Ni and Co silica supported catalysts, due to the low metal support interaction (MSI), promotes the formation of carbon filament with particles at tip. On the contrary, in case alumina was used as support, metals strongly interact with surface thus depressing both the metal sintering and the detachment of particles from catalyst surface. In such cases, carbon grows on metal particle with a “base mechanism” while particles remain well anchored on the catalyst surface. This allowed to realize a cyclic dual-step process based on methane decomposition and catalyst oxygen regeneration without deactivation of catalyst. Technological considerations have led to conclude that the implement of a process based on decomposition and regeneration of catalyst by oxidation requires the development of a robust catalytic system characterized by both a strong MSI and a well defined particle size distribution. In particular, the catalyst should be able to operate at high temperature, necessary to reach high methane conversion values (> 90%), avoiding at the same time the formation of both the carbon filaments with metal at tip or the encapsulating carbon which drastically deactivate the catalyst. [Copyright &y& Elsevier]

Abstract: Ni and Co supported on SiO2 and Al2O3 Silica Cloth Thin Layer Catalysts (TLC) were investigated in the Catalytic Decomposition of Natural Gas (CDNG) reaction using a Multilayer Catalytic Reactor (MCR). The influence of support and reaction temperature was evaluated with the aim to design a novel catalyst suitable to develop a dual-step process to produce pure hydrogen for fuel cell. Ni and Co silica supported catalyst, due to the low metal supported interaction (MSI) characterizing such systems, were not found suitable to efficiently perform CDNG reaction. On the contrary in case alumina was used as support both metals strongly interact with surface becoming so more resistant to sintering. In addition in case the metals (both Ni and Co) strongly interact with support surface, the formation of encapsulating carbon is depressed and only filamentous carbon forms. Using Ni and Co TLC supported on Al2O3 samples it has been possible to realize a cyclic dual-step process based on reaction and regeneration in oxygen stream without any catalyst detriment. A deactivation modelling to discriminate the role of sintering and coking on the deactivation pattern is proposed. [Copyright &y& Elsevier]

Abstract: Using a new structured multilayer reactor (MLR) that houses Ni based thin layer catalysts, catalytic decomposition of natural gas (CDNG) for making “CO x -free” hydrogen in a T R range of 773–873K was investigated. The influence of Ni loading (5–50wt%), Ni particle size, T R, and GHSV (h−1) on the reaction pattern was evaluated. A volcano shape relationship between H2 space time yield and Ni loading with a maximum range of 20–25wt% was found. H2 productivity and catalyst lifetime are controlled by the nature of the coke formed on Ni active species. As such, T R and GHSV significantly affect both the kinetics and the mechanism of coking. At T R <873K and low GHSV (<2000h−1), the prevailing formation of filamentous carbon (whisker-like) prolongs the catalyst lifetime, while at T R =873K and high GHSV (>2000h−1) encapsulating carbon is formed, causing a sudden decline in catalytic activity. A preliminary attempt to find optimal operating conditions ensuring the highest values of H2 productivity is presented. The features of the MLR that allowed CDNG reaction under a quasi-isothermal regime without any pressure drop, irrespective of operating conditions and the extent of carbon formation, are discussed. [Copyright &y& Elsevier]

The influence of the Mg addition on the catalytic performance of a 20% Ni based SiO2/silica cloth system in the decomposition of methane for making “CO x -free” H2 in the TR range 773–873 K has been evaluated. As the Mgat/Niat ratio increases from 0.10 to 2.20 the incipient Ni–Mg-O interaction becomes stronger until the formation of Ni x Mg(1− x)O solid solution. The presence of Mg2+ ions allows a higher carbon capacity (C/Ni, number of CH4 molecules converted per Ni atom until complete catalyst deactivation) and consequently a higher H2 productivity of the Ni based systems which results in a smoothing effect of the unavoidable declining activity trend even if it does not affect the tip growth coking mechanism. [ABSTRACT FROM AUTHOR]

The influence of the Mg addition on the catalytic performance of a 20% Ni based SiO2/silica cloth system in the decomposition of methane for making “CO x -free” H2 in the TR range 773–873 K has been evaluated. As the Mgat/Niat ratio increases from 0.10 to 2.20 the incipient Ni–Mg-O interaction becomes stronger until the formation of Ni x Mg(1− x)O solid solution. The presence of Mg2+ ions allows a higher carbon capacity (C/Ni, number of CH4 molecules converted per Ni atom until complete catalyst deactivation) and consequently a higher H2 productivity of the Ni based systems which results in a smoothing effect of the unavoidable declining activity trend even if it does not affect the tip growth coking mechanism. [ABSTRACT FROM AUTHOR]

Background: Varicocele still today represents a common cause of infertility in young men. The treatment strategy remains a surgical approach such as scleroembolization; however, the complete restoration of spermatic parameters afterward requires an average of six or more months to fully regain optimal seminal parameters. Recently, many studies have demonstrated the beneficial effects of Resveratrol in male fertility, given its potential anti-inflammatory, antiapoptotic, and mitochondrial effects. Therefore, Resveratrol-based nutraceuticals could be promising as an adjuvant to mitigate subfertility in patients with varicocele. Methods: In the present study, we retrospectively analyzed the effects of the administration of a Resveratrol-based nutraceutical after the scleroembolization procedure. The improvement of sperm quality in terms of number, motility, and morphology were considered to be the study's main endpoints. A spreadsheet program was used for data analysis, and a p -value of <0.05 was considered significant. Results: We found a statistically significant improvement in the spermatic parameters (sperm count and total motility) and an increase in normal sperm after only 4 months of treatment. The supplementation with a Resveratrol-based nutraceutical associated with the surgical procedure showed encouraging results if compared to data from a control group and the results reported in the literature linked to scleroembolization practice alone. In fact, there was a clear improvement in the seminal parameters at 4 months. Conclusions: This suggests the positive impact of the Resveratrol-based nutraceutical in synergizing with scleroembolization in reducing the time needed to fully recover sperm function.

Background: In hypertension, β-blockers have a high rate of nonadherence to treatment likely because of fatigue., Methods: We evaluate daily physical activity and maximal exercise performance in 56 patients with hypertension (grades I-II), with and without β-blockers (bisoprolol 10 mg or atenolol 100 mg) added to standard treatment; 48 patients completed the study. Study tests were performed after 8 weeks of antihypertensive therapy without β blockers and after the following 8 weeks with β-blockers., Results: No significant differences between β-blockers were observed. At office measurement, β-blockers decreased heart rate (HR) from 78 ± 9 to 62 ± 7 bpm (P < 0.01) and SBP from 133 ± 13 to 125 ± 12 mmHg (P < 0.01). No significant changes were observed for DBP. Conversely, at ambulatory pressure monitoring DBP but not SBP decreased with β-blockers (mean-24-h DBP 77 ± 8 vs. 74 ± 7 mmHg, P < 0.01). An overall reduction of daily activities and of estimated kilocalories consumption was observed as measured by a portable armband device. Of note, time with activity more than 3 METS was reduced by β-blockers from 148.1 (83-201) to 117.9 (82-189) min (P < 0.01). Cardiopulmonary exercise (CPE) showed a preserved exercise performance unaffected by β-blockers., Conclusion: In hypertension, β-blocker treatment is associated to reduction of daily physical activity but not of maximal exercise performance., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Coronary artery disease (CAD) represents the most common cardiovascular disease, with high morbidity and mortality. Historically patients with chest pain of suspected coronary origin have been assessed with functional tests, capable to detect haemodynamic consequences of coronary obstructions through depiction of electrocardiographic changes, myocardial perfusion defects or regional wall motion abnormalities under stress condition. Stress echocardiography (SE), single-photon emission computed tomography (SPECT), positron emission tomography (PET) and cardiovascular magnetic resonance (CMR) represent the functional techniques currently available, and technical developments contributed to increased diagnostic performance of these techniques. More recently, cardiac computed tomography angiography (cCTA) has been developed as a non-invasive anatomical test for a direct visualisation of coronary vessels and detailed description of atherosclerotic burden. Cardiovascular imaging techniques have dramatically enhanced our knowledge regarding physiological aspects and myocardial implications of CAD. Recently, after the publication of important trials, international guidelines recognised these changes, updating indications and level of recommendations. This review aims to summarise current standards with main novelties and specific limitations, and a diagnostic algorithm for up-to-date clinical management is also proposed.

We aimed to evaluate the feasibility and accuracy of machine learning-based automated dynamic quantification of left ventricular (LV) and left atrial (LA) volumes in an unselected population. We enrolled 600 unselected patients (12% in atrial fibrillation) clinically referred for transthoracic echocardiography (2DTTE), who also underwent 3D echocardiography (3DE) imaging. LV ejection fraction (EF), LV, and LA volumes were obtained from 2D images; 3D images were analyzed using dynamic heart model (DHM) software (Philips) resulting in LV and LA volume-time curves. A subgroup of 140 patients also underwent cardiac magnetic resonance (CMR) imaging. Average time of analysis, feasibility, and image quality were recorded, and results were compared between 2DTTE, DHM, and CMR. The use of DHM was feasible in 522/600 cases (87%). When feasible, the boundary position was considered accurate in 335/522 patients (64%), while major (n = 38) or minor (n = 149) border corrections were needed. The overall time required for DHM datasets was approximately 40 seconds. As expected, DHM LV volumes were larger than 2D ones (end-diastolic volume: 173 ± 64 vs. 142 ± 58 mL, respectively), while no differences were found for LV EF and LA volumes (EF: 55% ± 12 vs. 56% ± 14; LA volume 89 ± 36 vs. 89 ± 38 mL, respectively). The comparison between DHM and CMR values showed a high correlation for LV volumes (r = 0.70 and r = 0.82, p < 0.001 for end-diastolic and end-systolic volume, respectively) and an excellent correlation for EF (r = 0.82, p < 0.001) and LA volumes. The DHM software is feasible, accurate, and quick in a large series of unselected patients, including those with suboptimal 2D images or in atrial fibrillation.

MitraClip (MC) is the most common percutaneous treatment for severe mitral regurgitation (MR). An accurate two-dimensional and three-dimensional echocardiographic (3DTEE) imaging is mandatory for the optimal procedural result. Recently transillumination 3DTEE rendering (3DTr) has been introduced integrating a virtual light source into the dataset and with the addition of glass effect (3DGl) allows to adjust tissue transparency improving depth perception and anatomical structure delineation in comparison with the standard 3DTEE (3DSt). The aim of this retrospective study in 30 patients undergoing MC, was to compare 3DSt, 3DTr, and 3DGl in mitral valve (MV) evaluation and procedural result assessment. 3DTEE acquisitions obtained before and after MC were processed with 3DSt, 3DTr, and 3DGl rendering. Each reconstruction was scored for quality and for ability to recognize MV anatomy, MR origin, clip position, dimension and grasping. Imaging quality was judged good or optimal in 52%, 76%, and 96% in 3DSt, 3DTr, and 3DGl reconstructions respectively. In 26/30 patients a diagnostic incremental value was found with 3DTr vs. 3DSt and in 15/26 with 3DGl vs. 3DTr and 3DSt. Only 3DGl with perpendicular cropping of the clip allowed to visualize and measure the grasped portion of each mitral leaflets. 3DTEE imaging during MC may be improved by 3DTr and 3DGl providing a better evaluation of MV, of leaflet grasping and of residual MR jets after MC.

Psoriatic arthritis (PsA) patients are often treated by dermatology and rheumatology specialities and may receive different treatments. To evaluate the impact of dermatology/rheumatology specialist settings on diagnosis and therapeutic approach in PsA patients. This cross-sectional multicounty study in Italy involved twenty-eight rheumatology or dermatology clinics. Patients with suspected or confirmed PsA were examined by both a dermatologist and a rheumatologist. A total of 413 patients were enrolled and 347 (84%) were diagnosed with PsA. The majority of patients were enrolled from a rheumatology setting (N = 224, 64.6%). Patients with PsA in the dermatology settings had significantly higher disease activity, including skin involvement and musculoskeletal symptoms. Time from PsA onset to diagnosis was 22.3 ± 53.8 vs. 39.4 ± 77.5 months (p = 0.63) in rheumatology and dermatology settings; time from diagnosis to initiation of csDMARD was 7.3 ± 27.5 vs. 19.5 ± 50.6 months, respectively (p < 0.001). In contrast, time from diagnosis to bDMARD use was shorter in dermatology settings (54.9 ± 69 vs. 44.2 ± 65.6 months, p = 0.09, rheumatology vs. dermatology), similar to the time taken from first csDMARDs and bDMARDs (48.7 ± 67.9 vs. 35.3 ± 51.9 months, p = 0.34). The choice to visit a rheumatologist over a dermatologist was positively associated with female gender and swollen joints and negatively associated with delay in time from musculoskeletal symptom onset to PsA diagnosis. This study highlights a diagnostic delay emerging from both settings with significantly different therapeutic approaches. Our data reinforce the importance of implementing efficient strategies to improve early identification of PsA that can benefit from the integrated management of PsA patients. Key Points • A diagnostic delay was observed from both dermatology and rheumatology settings with significantly different therapeutic approaches. • Shared dermatology and rheumatology clinics offer the combined expertise to improve in the early identification and management of PsA.

Cardiovascular imaging is developing at a rapid pace and the newer modalities, in particular three-dimensional echocardiography, allow better analysis of heart structures. Identifying valve lesions and grading their severity represents crucial information and nowadays is strengthened by the introduction of new software, such as transillumination, which provide detailed morphology descriptions. Chambers quantification has never been so rapid and accurate: machine learning algorithms generate automated volume measurements, including left ventricular systolic and diastolic function, which is extremely important for clinical decisions. This review provides an overview of the latest innovations in the echocardiography field, and is helpful by providing a better insight into heart diseases.

Objective: Mitral annular disjunction (MAD) is an abnormality linked to mitral valve prolapse (MVP), possibly associated with malignant ventricular arrhythmias. We assessed the agreement among different imaging techniques for MAD identification and measurement., Methods: 131 patients with MVP and significant mitral regurgitation undergoing transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) were retrospectively enrolled. Transoesophageal echocardiography (TOE) was available in 106 patients. MAD was evaluated in standard long-axis views (four-chamber, two-chamber, three-chamber) by each technique., Results: Considering any-length MAD, MAD prevalence was 17.3%, 25.5%, 42.0% by TTE, TOE and CMR, respectively (p<0.05). The agreement on MAD identification was moderate between TTE and CMR (κ=0.54, 95% CI 0.49 to 0.59) and good between TOE and CMR (κ=0.79, 95% CI 0.74 to 0.84). Assuming CMR as reference and according to different cut-off values for MAD (≥2 mm, ≥4 mm, ≥6 mm), specificity (95% CI) of TTE and TOE was 99.6 (99.0 to 100.0)% and 98.7 (97.4 to 100.0)%; 99.3 (98.4 to 100.0)% and 97.6 (95.8 to 99.4)%; 97.8 (96.2 to 99.3)% and 93.2 (90.3 to 96.1)%, respectively; sensitivity (95% CI) was 43.1 (37.8 to 48.4)% and 74.5 (69.4 to 79.5)%; 54.0 (48.7 to 59.3)% and 88.9 (85.2 to 92.5)%; 88.0 (84.5 to 91.5)% and 100.0 (100.0 to 100.0)%, respectively. MAD length was 8.0 (7.0-10.0), 7.0 (5.0-8.0], 5.0 (4.0-7.0) mm, respectively by TTE, TOE and CMR. Agreement on MAD measurement was moderate between TTE and CMR (ρ=0.73) and strong between TOE and CMR (ρ=0.86)., Conclusions: An integrated imaging approach could be necessary for a comprehensive assessment of patients with MVP and symptoms suggestive for arrhythmias. If echocardiography is fundamental for the anatomic and haemodynamic characterisation of the MV disease, CMR may better identify small length MAD as well as myocardial fibrosis., Competing Interests: Competing interests: GP reports research grants and/or honorarium as speaker from GE Healthcare, Bracco, Bayer, Medtronic and Heartflow., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)