Technical Note: Design of rockfall net fences and the new ETAG 027 European guideline

Abstract. The need for protection against rockfall has led to the development of different types of technological solutions that are able to both prevent blocks from detaching from rock walls and to control, intercept or deviate the blocks during movement. Of the many devices that are able to intercept and stop a block, one of the most frequently used is net fence. Many different types of full-scale tests have been carried out, with different test site geometries and procedures to study their behaviour and to certify these devices. This has led to a series of data and information that are not easy to compare. The recent endorsement, by the European Organization for Technical Approvals (EOTA), of a European Technical Approval Guideline (ETAG), which defines how to test and assess the performance of a net fence, is therefore a great innovation that will change both the market and the design procedures of these devices. The most important innovations introduced by this new guideline are here presented and discussed and a net fence design procedure for protection against rockfall is provided

Biology of mitral valve prolapse: from general mechanisms to advanced molecular patterns—a narrative review

Mitral valve prolapse (MVP) represents the most frequent cause of primary mitral regurgitation. For several years, biological mechanisms underlying this condition attracted the attention of investigators, trying to identify the pathways responsible for such a peculiar condition. In the last ten years, cardiovascular research has moved from general biological mechanisms to altered molecular pathways activation. Overexpression of TGF-β signaling, for instance, was shown to play a key role in MVP, while angiotensin-II receptor blockade was found to limit MVP progression by acting on the same signaling pathway. Concerning extracellular matrix organization, the increased valvular interstitial cells density and dysregulated production of catalytic enzymes (matrix metalloproteinases above all) altering the homeostasis between collagen, elastin and proteoglycan components, have been shown to possibly provide a mechanistic basis contributing to the myxomatous MVP phenotype. Moreover, it has been observed that high levels of osteoprotegerin may contribute to the pathogenesis of MVP by increasing collagen deposition in degenerated mitral leaflets. Although MVP is believed to represent the result of multiple genetic pathways alterations, it is important to distinguish between syndromic and non-syndromic conditions. In the first case, such as in Marfan syndrome, the role of specific genes has been clearly identified, while in the latter a progressively increasing number of genetic loci have been thoroughly investigated. Moreover, genomics is gaining more interest as potential disease-causing genes and loci possibly associated with MVP progression and severity have been identified. Animal models could be of help in better understanding the molecular basis of MVP, possibly providing sufficient information to tackle specific mechanisms aimed at slowing down MVP progression, therefore developing non-surgical therapies impacting on the natural history of this condition. Although continuous progress has been made in this field, further translational studies are advocated to improve our knowledge of biological mechanisms underlying MVP development and progression

Surgical Repair of Postinfarction Ventricular Septal Rupture: Systematic Review and Meta-Analysis.

Background. Ventricular septal rupture (VSR) is a rare but life-threatening complication after acute myocardial infarction. Although surgical correction is challenging and associated with high mortality, it remains the treatment of choice. This systematic review and meta-analysis aimed to evaluate the early outcome of surgical VSR repair.Methods. We searched electronic databases from January 1998 to February 2020. Studies reporting patients undergoing surgical treatment for VSR were analyzed. The primary outcome assessed was operative mortality. Differences were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) to assess the relationships of predefined surgical variables and clinical prognosis.Results. A total of 6361 adult patients from 41 studies were identified. Operative mortality was 38.2%. Pooled ORs showed increased odds of operative mortality in patients with preoperative or perioperative intraaortic balloon pump insertion (OR = 3.48; 95% CI, 3.01-4.02; P >= .001), right ventricular dysfunction (OR = 2.85; 95% CI, 1.47-5.52; P = .002), posterior VSR (OR = 1.73; 95% CI, 1.30-2.31; P >= .001), and emergency surgery (OR = 3.79; 95% CI, 2.52-5.72; P >= .001). Temporal trend evaluation revealed no difference over time in the operative mortality rate; it was 34% in both time-related groups (1971-2000 versus 2001-2018).Conclusions. Ventricular septal rupture repair has a high operative mortality. Patients with preoperative or perioperative intraaortic balloon pump support, right ventricular dysfunction at presentation, or posterior defects, and those undergoing emergent VSR correction have increased odds of operative mortality. (C) 2021 by The Society of Thoracic Surgeons. Published by Elsevier Inc

Temperature responsive PEG-based polyurethanes “ a la carte”

Temperature responsive polymers able to alter their chemical or physical properties have been extensively investigated. Most of these polymers have an alkane polymer backbone with only carbon-carbon bonds. In this sense, the design of thermoresponsive polymers not only with sharp transition temperatures but also possessing hydrolizable linkages such as esters, carbonates or urethanes in the main backbone are highly desired. Here we show a library of thermoresponsive cationic and anionic polyurethanes synthesized by copolymerization of isophorone diisocyanate with poly(ethylene glycol) and ionic diols. These polyurethanes exhibit lower critical solution temperatures (LCST) that can be easily tuned from 20 C to 60 C by altering the polyurethane composition. Our findings show that LCST temperature could be reduced by the using poly(ethylene glycol) of lower molecular weight and/or increasing the hydrophobicity of the employed ionic diol. We also demonstrated that the thermoresponsive behavior could be translated to hydrogels based on those ionic polyurethanes. These “a la carte” thermoresponsive polyurethanes materials present a great potential in the biomedical field due to the presence of hydrolizable linkages in the main polymer backboneThe authors would like to thank the European Commission for their financial support through the project SUSPOL-EJD 642671 and the Gobierno Vasco/Eusko Jaurlaritza (Grant IT999-16). Ludmila I. Ronco thanks to the European Project IRSES-IONRUN and CONICET of Argentina for the financial support of her stay in Spain

Cost-effectiveness analysis of online hemodiafiltration versus high-flux hemodialysis

BACKGROUND: Clinical studies suggest that hemodiafiltration (HDF) may lead to better clinical outcomes than high-flux hemodialysis (HF-HD), but concerns have been raised about the cost-effectiveness of HDF versus HF-HD. Aim of this study was to investigate whether clinical benefits, in terms of longer survival and better health-related quality of life, are worth the possibly higher costs of HDF compared to HF-HD. METHODS: The analysis comprised a simulation based on the combined results of previous published studies, with the following steps: 1) estimation of the survival function of HF-HD patients from a clinical trial and of HDF patients using the risk reduction estimated in a meta-analysis; 2) simulation of the survival of the same sample of patients as if allocated to HF-HD or HDF using three-state Markov models; and 3) application of state-specific health-related quality of life coefficients and differential costs derived from the literature. Several Monte Carlo simulations were performed, including simulations for patients with different risk profiles, for example, by age (patients aged 40, 50, and 60 years), sex, and diabetic status. Scatter plots of simulations in the cost-effectiveness plane were produced, incremental cost-effectiveness ratios were estimated, and cost-effectiveness acceptability curves were computed. RESULTS: An incremental cost-effectiveness ratio of €6,982/quality-adjusted life years (QALY) was estimated for the baseline cohort of 50-year-old male patients. Given the commonly accepted threshold of €40,000/QALY, HDF is cost-effective. The probabilistic sensitivity analysis showed that HDF is cost-effective with a probability of ~81% at a threshold of €40,000/QALY. It is fundamental to measure the outcome also in terms of quality of life. HDF is more cost-effective for younger patients. CONCLUSION: HDF can be considered cost-effective compared to HF-HD

Extracorporeal life support in mitral papillary muscle rupture: Outcome of multicenter study

Background: Post-acute myocardial infarction papillary muscle rupture (post-AMI PMR) may present variable clinical scenarios and degree of emergency due to result of cardiogenic shock. Veno-arterial extracorporeal life support (V-A ECLS) has been proposed to improve extremely poor pre- or postoperative conditions. Information in this respect is scarce.Methods: From the CAUTION (meChanical complicAtion of acUte myocardial infarcTion: an InternatiOnal multiceNter cohort study) database (16 different Centers, data from 2001 to 2018), we extracted adult patients who were surgically treated for post-AMI PMR and underwent pre- or/and postoperative V-A ECLS support. The end-points of this study were in-hospital survival and ECLS complications.Results: From a total of 214 post-AMI PMR patients submitted to surgery, V-A ECLS was instituted in 23 (11%) patients. The median age was 61.7 years (range 46-81 years). Preoperatively, ECLS was commenced in 10 patients (43.5%), whereas intra/postoperative in the remaining 13. The most common V-A ECLS indication was post-cardiotomy shock, followed by preoperative cardiogenic shock and cardiac arrest. The median duration of V-A ECLS was 4 days. V-A ECLS complications occurred in more than half of the patients. Overall, in-hospital mortality was 39.2% (9/23), compared to 22% (42/219) for the non-ECLS group.Conclusions: In post-AMI PMR patients, V-A ECLS was used in almost 10% of the patients either to promote bridge to surgery or as postoperative support. Further investigations are required to better evaluate a potential for increased use and its effects of V-A ECLS in such a context based on the still high perioperative mortality

Prufrock, o L'Ecclesiaste

Nel testo si cerca di evidenziare un rapporto tra la poesia di Eliot e l'Ecclesiast

Bibliografia di Élisée Reclus

Questa bibliografia non pretende di essere esaustiva, ma tenta di essere un aiuto per tutti coloro che si accingeranno allo studio della estesa opera di Élisée Reclus, sia in campo geografico, sociologico, politico. Molti materiali certamente saranno ancora da rintracciare, dal momento che articoli, opuscoli e fogli volanti (prodotti in tutte le lingue del mondo) sono soggetti a sfuggire maggiormente e più facilmente alle normali catalogazioni bibliografiche

Le Battaglie di Antonio Gamberi

Si tratta della Prefazione al volume antologico delle poesie di Antonio Gamberi, poeta-minatore, socialista e antifascista, vissuto a cavallo tra ’800 e ’900. Gamberi, autodidatta, insegna a leggere e scrivere ai suoi compagni, perché quella di saper leggere e scrivere era, sul finire dell’Ottocento, una condizione indispensabile per poter votare, ma trova nello studio e nella cultura molto di più di uno strumento politico, vi trova il riscatto dall’ignoranza, il riscatto dalla sudditanza alle classi dirigenti colte e ricche. Solo quel riscatto, a suo modo di vedere, avrebbe permesso a lui e ai suoi compagni minatori di dar vita ad una società come egli spesso diceva “di giusti e di eguali”. Le sue poesie sono dunque partecipi di un periodo storico e sociale segnato da lotte contadine ed operaie per la libertà e per un mondo più giusto; Gamberi, minatore a Ribolla, partito da Roccatederighi per approdare in Spagna, in Belgio e in Francia, dove morì, rappresenta uno degli esempi più fulgidi di quei poeti militanti, cantori della tradizione risorgimentale, laica, anticlericale, libertaria e socialista, diffusa in Toscana e in Maremma in particolare