Studio su profili a basso numero di Reynolds con tecniche numeriche

Il presente lavoro di tesi ha come scopo lo studio su profili operanti a basso numero di Reynolds attraverso l’utilizzo del codice di calcolo STAR-CD 3.15. Il profilo preso in esame è l’SG 6042, di cui si ha a disposizione la polare sperimentalmente ottenuta per Re = 100.000. Data la fenomenologia caratterizzata del basso valore del numero di Reynolds, lo studio si è principalmente concentrato sulla valutazione dei parametri che meglio approssimano il comportamento reale del flusso: griglia di calcolo, modello di turbolenza, condizioni al contorno, metodo di soluzione delle equazioni di campo. Vengono, inoltre, riportati tutti i risultati numerici e i grafici relativi alle grandezze d’interesse e, di seguito, una loro approfondita analisi

Peach [Prunus persica (L.) Batsch] KNOPE1, a class 1 KNOX orthologue to Arabidopsis BREVIPEDICELLUS/KNAT1, is misexpressed during hyperplasia of leaf curl disease

Class 1 KNOTTED-like (KNOX) transcription factors control cell meristematic identity. An investigation was carried out to determine whether they maintain this function in peach plants and might act in leaf curliness caused by the ascomycete Taphrina deformans. KNOPE1 function was assessed by overexpression in Arabidopsis and by yeast two-hybrid assays with Arabidopsis BELL proteins. Subsequently, KNOPE1 mRNA and zeatin localization was monitored during leaf curl disease. KNOPE1 and Arabidopsis BREVIPEDICELLUS (BP) proteins fell into the same phyletic group and recognized the same BELL factors. 35S:KNOPE1 Arabidopsis lines exhibited altered traits resembling those of BP-overexpressing lines. In peach shoot apical meristem, KNOPE1 was expressed in the peripheral and central zones but not in leaf primordia, identically to the BP expression pattern. These results strongly suggest that KNOPE1 must be down-regulated for leaf initiation and that it can control cell meristem identity equally as well as all class 1 KNOX genes. Leaves attacked by T. deformans share histological alterations with class 1 KNOX-overexpressing leaves, including cell proliferation and loss of cell differentiation. Both KNOPE1 and a cytokinin synthesis ISOPENTENYLTRANSFERASE gene were found to be up-regulated in infected curled leaves. At early disease stages, KNOPE1 was uniquely triggered in the palisade cells interacting with subepidermal mycelium, while zeatin vascular localization was unaltered compared with healthy leaves. Subsequently, when mycelium colonization and asci development occurred, both KNOPE1 and zeatin signals were scattered in sectors of cell disorders. These results suggest that KNOPE1 misexpression and de novo zeatin synthesis of host origin might participate in hyperplasia of leaf curl disease

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

ECMOLIFE intra-hospital transport in life-saving for pulmonary vein obstruction

Abstract Background Transport with extracorporeal membrane oxygenation (ECMO) in the hospital setting can become a challenge as well as in the out-of-hospital setting. In particular, the management of intra-hospital transport with ECMO support of the critically ill patient foresees his shift from the intensive care to the diagnostic areas, from the diagnostic areas to the interventional and surgical areas. Case presentation In this context, we present a life-saving transport case with the veno-venous (VV) configuration of the ECMOLIFE Eurosets system, for right heart and respiratory failure in a 54-year-old woman, due to thrombosed obstruction of the right superior pulmonary vein, following mitral valve repair surgery in minimally invasive approach in a patient already operated on for complex congenital heart disease. After stabilizing the vital parameters with Veno-venous ECMO for 19 h, the patient was transported to hemodynamics for angiography of the pulmonary vessels, where the diagnosis of obstruction of the pulmonary venous return was made. Subsequently, the patient was brought back to the operating room for a procedure of unblocking the right superior pulmonary vein using a minimally invasive approach, passing from the ECMO to the support in extracorporeal circulation. Conclusions The transportable ECMOLIFE Eurosets System was safe and effective during transport in maintaining the vital parameters of oxygenation and CO2 reuptake and systemic flow, allowing the patient to be mobilized for diagnostic tests instrumental to diagnosis. The patient was extubated 36 h after the surgical procedures and was discharged 10 days later from the hospital

A new technique to adjust the length of artificial chordae during mitral anterior leaflet repair

Background Length measurement of artificial chordae remains a critical step during mitral valve repair (MVr). The aim of this study is to assess the effectiveness of a new length measuring technique. Methods All consecutive patients with anterior leaflet prolapse/flail who underwent MVr using the described method between January 2020 and January 2022 at our institution were included in the analysis. Clinical and transesophageal echocardiography data were collected postoperatively and at 1-year follow-up. The primary outcome was freedom from mitral regurgitation (MR). Secondary outcomes were presentation with New York Heart Association (NYHA) class Of 25 patients, 16 (64%) were males. A total of 15 (60%) had isolated anterior leaflet disease, while 10 (40%) had concomitant posterior involvement. Twenty patients with isolated MR (80%) underwent right anterior mini-thoracotomy, while 5 (20%) with associated valvular or coronary disease underwent sternotomy. The median number of chordae implanted was 2 [1-4]. Postrepair intraoperative MR grade was 0 in 23 patients (92%) and 1 in 2 (8%). Thirty-day mortality was 0%. De novo atrial fibrillation was 20%. At follow-up, mortality was 0%. No patients presented with moderate or severe MR. A total of 22 patients (88%) were in NYHA class I, while 3 (12%) in class II. The coaptation length was 11 +/- 1 mm. Conclusions The short-term outcomes of the described technique are good with adequate leaflet coaptation in all treated patients. Long-term results are needed to assess the stability and durability of this repair technique

Predictors of late arrhythmic events after generator replacement in Brugada syndrome treated with prophylactic ICD

INTRODUCTION: Predictors of late life-threatening arrhythmic events in Brugada syndrome (BrS) patients who received a prophylactic ICD implantation remain to be evaluated. The aim of the present long-term multicenter study was to assess the incidence and clinical-electrocardiographic predictors of late life-threatening arrhythmic events in BrS patients with a prophylactic implantable cardioverter defibrillator (ICD) and undergoing generator replacement (GR). METHODS: The study population included 105 patients (75% males; mean age 45 ± 14years) who received a prophylactic ICD and had no arrhythmic event up to first GR. RESULTS: The median period from first ICD implantation to last follow-up was 155 (128–181) months and from first ICD Implantation to the GR was 84 (61–102) months. During a median follow-up of 57 (38–102) months after GR, 10 patients (9%) received successful appropriate ICD intervention (1.6%/year). ICD interventions included shock on ventricular fibrillation (n = 8 patients), shock on ventricular tachycardia (n = 1 patient), and antitachycardia pacing on ventricular tachycardia (n = 1 patient). At survival analysis, history of atrial fibrillation (log-rank test; P = 0.02), conduction disturbances (log-rank test; P < 0.01), S wave in lead I (log-rank test; P = 0.01) and first-degree atrioventricular block (log-rank test; P = 0.04) were significantly associated with the occurrence of late appropriate ICD intervention. At Cox-regression multivariate analysis, S-wave in lead I was the only independent predictor of late appropriate ICD intervention (HR: 9.17; 95%CI: 1.15–73.07; P = 0.03). CONCLUSIONS: The present study indicates that BrS patient receiving a prophylactic ICD may experience late appropriate intervention after GR in a clinically relevant proportion of cases. S-wave in lead I at the time of first clinical evaluation was the only independent predictor of persistent risk of life-threatening arrhythmic events. These findings support the need for GR at the end of service regardless of previous appropriate intervention, mostly in BrS patients with conduction abnormalities