Chimneys in wooden roofs: a 3D steady numerical model for the prediction of the temperatures

Chimneys convey exhaust gas produced in domestic heat appliances to the external environment and to do this they have to pass through floors and roofs: if these elements are made up of flammable materials, the fire hazard may occur. This article presents the verification of a 3D numerical model set for the determination of the stationary temperatures reached on the flammable materials in the vicinity of chimneys. The verification has been done comparing the temperatures measured in experimental tests with those estimated by means of the numerical model. Results show that the 3D numerical model is a valid tool for the analysis of heat transfer between chimney and roof. Since in the experimental tests it is not always possible to reach stationary temperatures, a lumped element model to estimate them is also proposed and it could support the chimney certification

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Inclusive and differential measurements of the t(t)over-bar charge asymmetry in pp collisions at root s=8 TeV

Peer reviewe

DISPOSITIVO ISOLANTE PER CANNE FUMARIE INSTALLATE IN STRUTTURE EDILIZIE

DISPOSITIVO ISOLANTE PER CANNE FUMARIE INSTALLATE IN STRUTTURE EDILIZIE La presente invenzione ha come oggetto un dispositivo per limitare la temperatura dei materiali infiammabili di tetti attraversati da canne fumarie. Il dispositivo della presente domanda di brevetto è destinato al settore dell’evacuazione fumi nel settore delle costruzioni edile e/o industriale, da impiegarsi laddove si ravvisano condizioni di pericolo di incendio per la presenza di materiali combustibili, come ad esempio solai o tetti in legno. Scopo dell’invenzione è limitare la temperatura dei materiali combustibili in prossimità di una canna fumaria, evitare la formazione di ponti termici, e generare un recupero del calore proveniente dalla canna fumaria. Il dispositivo deve essere montato sulla superficie esterna della canna fumaria nel punto in cui quest’ultima attraversa elementi edilizi quali solai e/o tetti. Il dispositivo è costituito da elementi in materiale isolante ed elementi in materiale conduttivo che per la loro forma e posizione consentono di limitare la temperatura dei materiali infiammabili del tetto in cui è installata la canna fumaria

Early Hemodynamic and Biochemical Changes in Overloaded Swine Ventricle

The present study was undertaken to investigate, in an animal model, the relationship between sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) activity, phospholamban phosphorylation, acylphosphatase activity, and hemodynamic changes that occur in the early phase of pressure overload. In 54 study-group pigs, weighing 40±5 kg each, an aortic stenosis was created with a band of umbilical tape tied around the aorta; 18 sham-operated pigs formed our control group. Eight animals (6 study and 2 control) were randomly assigned to each experimental time (0.5, 3, 6, 12, 24, 48, 72, 96, and 168 hr). All indices of left ventricular function declined significantly, with a peak at 6 hr and a return to baseline at 168 hr. At each observational time, SERCA2a activity, Ca2+ uptake, and acylphosphatase activity rose significantly, with a maximum increase at 6 hr. These changes indicated a higher expression of these proteins; conversely, phospholamban did not show significant changes in its concentration or in its phosphorylation status. Nuclear proto-oncogene c-fos expression rose at 6 hr. A strong inverse correlation was found when Ca2+-ATPase activity, Ca2+-ATPase expression, Ca2+ uptake, and acylphosphatase were compared with indices of systolic function. In our model of induced pressure overload, an initial phase of depressed myocardial contractility was accompanied by an increased sarcoplasmic reticulum function and by higher Ca2+-ATPase and Ca2+ uptake activities mediated by acylphosphatase. This new finding of Ca2+ homeostasis might indicate a compensatory mechanism for mechanical stress. Further studies are needed to confirm our findings

Contact forces during hybrid atrial fibrillation ablation: an in vitro evaluation

PURPOSE: Data on epicardial contact force efficacy in dual epicardial–endocardial atrial fibrillation ablation procedures are lacking. We present an in vitro study on the importance of epicardial and endocardial contact forces during this procedure. METHODS: The in vitro setup consists of two separate chambers, mimicking the endocardial and epicardial sides of the heart. A circuit, including a pump and a heat exchanger, circulates porcine blood through the endocardial chamber. A septum, with a cut out, allows the placement of a magnetically fixed tissue holder, securing porcine atrial tissue, in the middle of both chambers. Two trocars provide access to the epicardium and endocardium. Force transducers mounted on both catheter holders allow real-time contact force monitoring, while a railing system allows controlled contact force adjustment. We histologically assessed different combinations of epi-endocardial radiofrequency ablation contact forces using porcine atria, evaluating the ablation’s diameters, area, and volume. RESULTS: An epicardial ablation with forces of 100 or 300 g, followed by an endocardial ablation with a force of 20 g did not achieve transmurality. Increasing endocardial forces to 30 and 40 g combined with an epicardial force ranging from 100 to 300 and 500 g led to transmurality with significant increases in lesion’s diameters, area, and volumes. CONCLUSIONS: Increased endocardial contact forces led to larger ablation lesions regardless of standard epicardial pressure forces. In order to gain transmurality in a model of a combined epicardial–endocardial procedure, a minimal endocardial force of 30 g combined with an epicardial force of 100 g is necessary