71 research outputs found

    THE DESERT ROSE DOMES OF THE SOUF REGION (ALGERIA). PRELIMINARY EVALUATIONS ON THE VULNERABILITY OF A UNIQUE VERNACULAR HERITAGE

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    Abstract. The vernacular architecture of the Souf region in Algeria, a desert environment where wood is rare, presents multiple heritage values due to the way in which local materials (especially the desert rose stone) are exploited to build houses and erect distinctive domes. Unfortunately, extensive damage and abandonment compromise the stability of these buildings and accelerate their disappearance, which would negatively affect the urban landscape and the identity of the region. In order to safeguard this unique vernacular heritage, the study focuses on the definition of the typical typology of building, its structural and geometric characteristics, explaining the constructive technique used. Recurrent damage and pathologies that threaten this building culture are also highlighted. Then, estimation of mechanical parameters of the desert rose stone masonry is carried out defining typical characteristics according to the evaluation of the respect of "the rule of the art". Results are then used to perform numerical simulations of the structural behaviour of a typical building, through the finite element method with linear and nonlinear approaches. In particular, the structural behaviour of the dome has been investigated, being the most vulnerable element of the system

    Ventilator-associated pneumonia in patients with covid-19: A systematic review and meta-analysis

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    The aim of this systematic review and meta-analysis was to estimate the pooled occurrence of ventilator-associated pneumonia (VAP) among patients admitted to an intensive care unit with COVID-19 and mortality of those who developed VAP. We performed a systematic search on PubMed, EMBASE and Web of Science from inception to 2nd March 2021 for nonrandomized studies specifically addressing VAP in adult patients with COVID-19 and reporting data on at least one primary outcome of interest. Random effect single-arm meta-analysis was performed for the occurrence of VAP and mortality (at the longest follow up) and ICU length of stay. Twenty studies were included in the systematic review and meta-analysis, for a total of 2611 patients with at least one episode of VAP. The pooled estimated occurrence of VAP was of 45.4% (95% C.I. 37.8–53.2%; 2611/5593 patients; I2 = 96%). The pooled estimated occurrence of mortality was 42.7% (95% C.I. 34–51.7%; 371/946 patients; I2 = 82%). The estimated summary estimated metric mean ICU LOS was 28.58 days (95% C.I. 21.4–35.8; I2 = 98%). Sensitivity analysis showed that patients with COVID-19 may have a higher risk of developing VAP than patients without COVID-19 (OR 3.24; 95% C.I. 2.2–4.7; P = 0.015; I2 = 67.7%; five studies with a comparison group)

    Procalcitonin levels in candidemia versus bacteremia: A systematic review

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    open7BackgroundProcalcitonin (PCT) is a biomarker used to assess systemic inflammation, infection, and sepsis and to optimize antimicrobial therapies. Its role in thein the differential diagnosis between candidemia and bacteremia is unclear. The aim of this systematic review was to summarize the current evidence about PCT values for differentiating candidemia from bacteremia.MethodsPubMed and EMBASE were searched for studies reporting data on the diagnostic performance of serum PCT levels in intensive care unit (ICU) or non-ICU adult patients with candidemia, in comparison to patients with bacteremia.ResultsWe included 16 studies for a total of 45.079 patients and 785 cases of candidemia. Most studies claimed to report data relating to the use of PCT values for differentiating between candidemia and bacteremia in septic patients in the intensive care unit. However, the studies identified were all retrospective, except for one secondary analysis of a prospective dataset, and clinically very heterogeneous and involved different assessment methods. Most studies did show lower PCT values in patients with candidemia compared to bacteremia. However, the evidence supporting this observation is of low quality and the difference seems insufficiently discriminative to guide therapeutic decisions. None of the studies retrieved actually studied guidance of antifungal treatment by PCT. PCT may improve diagnostic performance regarding candidemia when combined with other biomarkers of infection (e.g., beta-d-glucan) but more data is needed.ConclusionsPCT should not be used as a standalone tool for the differential diagnosis between candidemia and bacteremia due to limited supporting evidence.openCortegiani A.; Misseri G.; Ippolito M.; Bassetti M.; Giarratano A.; Martin-Loeches I.; Einav S.Cortegiani, A.; Misseri, G.; Ippolito, M.; Bassetti, M.; Giarratano, A.; Martin-Loeches, I.; Einav, S

    Procalcitonin levels in candidemia versus bacteremia: A systematic review

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    Background: Procalcitonin (PCT) is a biomarker used to assess systemic inflammation, infection, and sepsis and to optimize antimicrobial therapies. Its role in the in the differential diagnosis between candidemia and bacteremia is unclear. The aim of this systematic review was to summarize the current evidence about PCT values for differentiating candidemia from bacteremia. Methods: PubMed and EMBASE were searched for studies reporting data on the diagnostic performance of serum PCT levels in intensive care unit (ICU) or non-ICU adult patients with candidemia, in comparison to patients with bacteremia. Results: We included 16 studies for a total of 45.079 patients and 785 cases of candidemia. Most studies claimed to report data relating to the use of PCT values for differentiating between candidemia and bacteremia in septic patients in the intensive care unit. However, the studies identified were all retrospective, except for one secondary analysis of a prospective dataset, and clinically very heterogeneous and involved different assessment methods. Most studies did show lower PCT values in patients with candidemia compared to bacteremia. However, the evidence supporting this observation is of low quality and the difference seems insufficiently discriminative to guide therapeutic decisions. None of the studies retrieved actually studied guidance of antifungal treatment by PCT. PCT may improve diagnostic performance regarding candidemia when combined with other biomarkers of infection (e.g., beta-D-glucan) but more data is needed. Conclusions: PCT should not be used as a standalone tool for the differential diagnosis between candidemia and bacteremia due to limited supporting evidence

    Seismic Vulnerability Assessment of a 17th Century Colonial Adobe Church in the Central Valley of Chile

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    This paper focuses on the seismic vulnerability assessment of the San Judas TadeoŽs church in Malloa (Chile), an iconic example of Colonial Chilean architecture. This small adobe structure is a single-nave building consisting of the main nave, a bell-tower located in the façade, two external wooden galleries and additional units such as the sacristy, chapel, and two services areas. The Church has survived several strong earthquakes larger than Mw>8. Besides, after the February 27th, 2010 Maule event it showed remarkable resilience due to the implementation of traditional timber retrofits inserted in the earthen walls. The use of traditional wooden devices such as bond beams, corner keys, and wooden gables, proved to be effective solutions against strong earthquakes. Therefore, this church appears as a relevant case of the use of seismic resistant constructive techniques of the17th century colonial architecture and the study of its seismic behaviour holds great interest and relevance. Aimed to assess the seismic performance of the monument, a complete preliminary study of the church was carried out using a multi-level approach comprising historical research, in situ surveys, crack pattern analysis, physical and mechanical characterization of materials, and structural analyses. In particular as part of an ongoing research, linear and incremental kinematic approaches of limit analyses have been employed with the aim of interpreting the local mechanisms activated during the 2010 Maule earthquake. In these models, the effect of friction on masonry-to-masonry and timber-to-masonry interfaces was considered with promising outcomes. This study results prove the general validity in the field of timber seismic retrofitting of unreinforced adobe buildings

    Tidal Volume Estimation during Helmet Noninvasive Ventilation: an Experimental Feasibility Study

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    We performed a bench (BS) and human (HS) study to test the hypothesis that estimation of tidal volume (VT) during noninvasive helmet pressure support ventilation (nHPSV) would be possible using a turbine driven ventilator (TDV) coupled with an intentional leak single-limb vented circuit. During the BS a mannequin was connected to a lung simulator (LS) and at different conditions of respiratory mechanics, positive end expiratory pressure (PEEP) levels and leaks (30, 50 and 80 L/min). All differences were within the 95% limits of agreement (LoA) in all conditions in the Bland-Altman plot. The overall bias (difference between VT measured by TDV and LS) was 35 ml (95% LoA 10 to 57 ml), 15 ml (95% LoA -40 to 70 ml), 141 ml (95% LoA 109 to 173 ml) in the normal, restrictive and obstructive conditions. The bias at different leaks flow in normal condition was 29 ml (95% LoA 19 to 38 ml). In the HS four healthy volunteers using nHPSV had a pneumotachograph (P) inserted through a mouthpiece to measure subject's VT.The bias showed a scarce clinical relevance. In conclusions, VT estimation seems to be feasible and accurate in all conditions but the obstructive one. Additional leaks seem not to affect VT reliability

    Conditional Ablation of Macrophages Halts Progression of Crescentic Glomerulonephritis

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    The presence of macrophages in inflamed glomeruli of rat kidney correlates with proliferation and apoptosis of resident glomerular mesangial cells. We assessed the contribution of inflammatory macrophages to progressive renal injury in murine crescentic glomerulonephritis (GN). Using a novel transgenic mouse (CD11b-DTR) in which tissue macrophages can be specifically and selectively ablated by minute injections of diphtheria toxin, we depleted renal inflammatory macrophages through days 15 and 20 of progressive crescentic GN. Macrophage depletion reduced the number of glomerular crescents, improved renal function, and reduced proteinuria. Morphometric analysis of renal tubules and interstitium revealed a marked attenuation of tubular injury that was associated with reduced proliferation and apoptosis of tubular cells. The population of interstitial myofibroblasts decreased after macrophage depletion and interstitial fibrosis also decreased. In the presence of macrophages, interstitial myofibroblasts exhibited increased levels of both proliferation and apoptosis, suggesting that macrophages act to support a population of renal myofibroblasts in a high turnover state and in matrix deposition. Finally, deletion of macrophages reduced CD4 T cells in the diseased kidney. This study demonstrates that macrophages are key effectors of disease progression in crescentic GN, acting to regulate parenchymal cell populations by modulating both cell proliferation and apoptosis

    Epidemiology of intra-abdominal infection and sepsis in critically ill patients: “AbSeS”, a multinational observational cohort study and ESICM Trials Group Project

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    Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection
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