Our work proposes a comparison between Spark Plasma Sintering of LiFePO4 carried out using an Alternating Current (AC) and Direct Current (DC). It quantifies the Li-ion migration using DC, and it ...validates such hypothesis using impedance spectroscopy, X-ray photoelectron spectroscopy and inductively coupled plasma optical emission spectroscopy. The use of an AC field seems effective to inhibit undesired Li-ion migration and achieve high ionic conductivity as high as 4.5 × 10−3 S/cm, which exceeds by one order of magnitude samples processed under a DC field. These results anticipate the possibility of fabricating a high-performance all-solid-state Li-ion battery by preventing undesired Li loss during SPS processing.
Identification of soil condition at the working face of a tunnel boring machine (TBM) is a key factor for the efficiency and safety of TBM tunneling. The paper presents the first application of the ...Horizontal-to-Vertical Spectral Ratio (HVSR) method on microtremors induced by a TBM during tunnelling. The innovative application is based on the development of an easy-to-use and economical early-warning system, which aims to confirm, or otherwise, the soil profile established in the design phase of tunnels by comparing the soil natural frequencies obtained from the soil profile carried out during the design phase and the soil natural frequencies coming from the HVSR analysis of the microtremors induced by the TBM during tunnelling. Just one or two geophones are necessary to use the proposed procedure. It can be applied to an area up to about 20 m ahead of the TBM excavation front and constitutes a powerful early warning system. Due to the great heterogeneity of the subsoil, dual-mode TBMs are often used, frequently changing from Open-Face (OF) mode for rock formations to Earth Pressure Balance (EPB) mode for cohesive and incoherent soil. Any “additional” information on the soil, which will be dug in the next days or hours is extremely useful for subsoil with great heterogeneity. The new procedure offers a reasonable time interval in which to modify the excavation method. This, in turn, can avoid damage to the TBM and existing structures and infrastructures. It allows us also to have a valuable geotechnical database for future works on the infrastructural networks. The proposed procedure has been successfully applied during the construction of the new underground lines in Catania (Italy).
Abstract Patients with acute exacerbation of lung fibrosis with usual interstitial pneumonia (EUIP) pattern are at increased risk for ventilator-induced lung injury (VILI) and mortality when exposed ...to mechanical ventilation (MV). Yet, lack of a mechanical model describing UIP-lung deformation during MV represents a research gap. Aim of this study was to develop a constitutive mathematical model for UIP-lung deformation during lung protective MV based on the stress–strain behavior and the specific elastance of patients with EUIP as compared to that of acute respiratory distress syndrome (ARDS) and healthy lung. Partitioned lung and chest wall mechanics were assessed for patients with EUIP and primary ARDS (1:1 matched based on body mass index and PaO 2 /FiO 2 ratio) during a PEEP trial performed within 24 h from intubation. Patient’s stress–strain curve and the lung specific elastance were computed and compared with those of healthy lungs, derived from literature. Respiratory mechanics were used to fit a novel mathematical model of the lung describing mechanical-inflation-induced lung parenchyma deformation, differentiating the contributions of elastin and collagen, the main components of lung extracellular matrix. Five patients with EUIP and 5 matched with primary ARDS were included and analyzed. Global strain was not different at low PEEP between the groups. Overall specific elastance was significantly higher in EUIP as compared to ARDS (28.9 22.8–33.2 cmH 2 O versus 11.4 10.3–14.6 cmH 2 O, respectively). Compared to ARDS and healthy lung, the stress/strain curve of EUIP showed a steeper increase, crossing the VILI threshold stress risk for strain values greater than 0.55. The contribution of elastin was prevalent at lower strains, while the contribution of collagen was prevalent at large strains. The stress/strain curve for collagen showed an upward shift passing from ARDS and healthy lungs to EUIP lungs. During MV, patients with EUIP showed different respiratory mechanics, stress–strain curve and specific elastance as compared to ARDS patients and healthy subjects and may experience VILI even when protective MV is applied. According to our mathematical model of lung deformation during mechanical inflation, the elastic response of UIP-lung is peculiar and different from ARDS. Our data suggest that patients with EUIP experience VILI with ventilatory setting that are lung-protective for patients with ARDS.
The double perovskites Sr2SmNbO6, Sr2CoNbO6 and Ba2CoNbO6 were investigated with first principles computations based on the density functional theory and plus U treatment. Firstly, different ...calculation methods were examined in order to quantitatively approach the exact band gap. It was found that neither the strongly constrained and appropriately normed (SCAN) semilocal density functional nor the hybrid HSE06 functional can well address the semiconducting nature of the investigated double perovskites, while PBE + U or SCAN + U with appropriately determining the U value can have good performance, which paves the way for future studies of double perovskites. With self-consistently calculated electron correlation strength, the magnetic states and the band gaps of the Sr2CoNbO6 and Ba2CoNbO6 were more precisely determined. The electronic, optical and thermoelectric properties were then investigated and discussed for possible applications.
To create your abstract, type over the instructions in the template box below. Display omitted
During one-lung ventilation (OLV), titrating the positive end-expiratory pressure (PEEP) to target a low driving pressure (∆P) could reduce postoperative pulmonary complications. However, it is ...unclear how to conduct PEEP titration: by stepwise increase starting from zero PEEP (PEEP
INCREMENTAL
) or by stepwise decrease after a lung recruiting manoeuvre (PEEP
DECREMENTAL
). In this randomized trial, we compared the physiological effects of these two PEEP titration strategies on respiratory mechanics, ventilation/perfusion mismatch and gas exchange. Patients undergoing video-assisted thoracoscopic surgery in OLV were randomly assigned to a PEEP
INCREMENTAL
or PEEP
DECREMENTAL
strategy to match the lowest ∆P. In the PEEP
INCREMENTAL
group, PEEP was stepwise titrated from ZEEP up to 16 cm H
2
O, whereas in the PEEP
DECREMENTAL
group PEEP was decrementally titrated, starting from 16 cm H
2
O, immediately after a lung recruiting manoeuvre. Respiratory mechanics, ventilation/perfusion mismatch and blood gas analyses were recorded at baseline, after PEEP titration and at the end of surgery. Sixty patients were included in the study. After PEEP titration, shunt decreased similarly in both groups, from 50 39–55% to 35 28–42% in the PEEP
INCREMENTAL
and from 45 37–58% to 33 25–45% in the PEEP
DECREMENTAL
group (both p < 0.001 vs baseline). The resulting ∆P, however, was lower in the PEEP
DECREMENTAL
than in the PEEP
INCREMENTAL
group (8 7–11 vs 10 9–11 cm H
2
O; p = 0.03). In the PEEP
DECREMENTAL
group the PaO
2
/ FIO
2
ratio increased significantly after intervention (from 140 99–176 to 186 152–243, p < 0.001). Both the PEEP
INCREMENTAL
and the PEEP
DECREMENTAL
strategies were able to decrease intraoperative shunt, but only PEEP
DECREMENTAL
improved oxygenation and lowered intraoperative ΔP.
Clinical trial number
NCT03635281; August 2018; “retrospectively registered”
Background:
Bilateral opacities on chest radiographs are part of the Berlin Definition for Acute Respiratory Distress Syndrome (ARDS) but have poor interobserver reliability. The “Radiographic ...Assessment of Lung Edema” (RALE) score was recently proposed for evaluation of the extent and density of alveolar opacities on chest radiographs of ARDS patients. The current study determined the accuracy of the RALE score for the diagnosis and the prognosis of ARDS.
Methods:
Post-hoc
analysis of a cohort of invasively ventilated intensive care unit (ICU) patients expected to need invasive ventilation for >24 h. The Berlin Definition was used as the gold standard. The RALE score was calculated for the first available chest radiograph after start of ventilation in the ICU. The primary endpoint was the diagnostic accuracy for ARDS of the RALE score. Secondary endpoints included the prognostic value of the RALE score for ICU and hospital mortality, and the association with ARDS severity, and the PaO
2
/FiO
2
. Receiver operating characteristic (ROC) curves were constructed, and the optimal cutoff was used to determine sensitivity, specificity and the negative and positive predictive value of the RALE score for ARDS.
Results:
The study included 131 patients, of whom 30 had ARDS (11 mild, 15 moderate, and 4 severe ARDS). The first available chest radiograph was obtained median 0 0 to 1 days after start of invasive ventilation in ICU. Compared to patients without ARDS, a higher RALE score was found in patients with ARDS (24 interquartile range (IQR) 16–30
vs.
6 IQR 3–11;
P
< 0.001), with RALE scores of 20 IQR 14–24, 26 IQR 16–32, and 32 IQR 19–36 for mild, moderate and severe ARDS, respectively, (
P
= 0.166). The area under the ROC for ARDS was excellent (0.91 0.86–0.96). The best cutoff for ARDS diagnosis was 10 with 100% sensitivity, 71% specificity, 51% positive predictive value and 100% negative predictive value. The RALE score was not associated with ICU or hospital mortality, and weakly correlated with the PaO
2
/FiO
2
.
Conclusion:
In this cohort of invasively ventilated ICU patients, the RALE score had excellent diagnostic accuracy for ARDS.
Background Sepsis is characterized by a dysregulated immune response and metabolic alterations, including decreased high-density lipoprotein cholesterol (HDL-C) levels. HDL exhibits beneficial ...properties, such as lipopolysaccharides (LPS) scavenging, exerting anti-inflammatory effects and providing endothelial protection. We investigated the effects of CER-001, an engineered HDL-mimetic, in a swine model of LPS-induced acute kidney injury (AKI) and a Phase 2a clinical trial, aiming to better understand its molecular basis in systemic inflammation and renal function. Methods We carried out a translational approach to study the effects of HDL administration on sepsis. Sterile systemic inflammation was induced in pigs by LPS infusion. Animals were randomized into LPS (n = 6), CER20 (single dose of CER-001 20 mg/kg; n = 6), and CER20 x 2 (two doses of CER-001 20 mg/kg; n = 6) groups. Survival rate, endothelial dysfunction biomarkers, pro-inflammatory mediators, LPS, and apolipoprotein A-I (ApoA-I) levels were assessed. Renal and liver histology and biochemistry were analyzed. Subsequently, we performed an open-label, randomized, dose-ranging (Phase 2a) study included 20 patients with sepsis due to intra-abdominal infection or urosepsis, randomized into Group A (conventional treatment, n = 5), Group B (CER-001 5 mg/kg BID, n = 5), Group C (CER-001 10 mg/kg BID, n = 5), and Group D (CER-001 20 mg/kg BID, n = 5). Primary outcomes were safety and efficacy in preventing AKI onset and severity; secondary outcomes include changes in inflammatory and endothelial dysfunction markers. Results CER-001 increased median survival, reduced inflammatory mediators, complement activation, and endothelial dysfunction in endotoxemic pigs. It enhanced LPS elimination through the bile and preserved liver and renal parenchyma. In the clinical study, CER-001 was well-tolerated with no serious adverse events related to study treatment. Rapid ApoA-I normalization was associated with enhanced LPS removal and immunomodulation with improvement of clinical outcomes, independently of the type and gravity of the sepsis. CER-001-treated patients had reduced risk for the onset and progression to severe AKI (stage 2 or 3) and, in a subset of critically ill patients, a reduced need for organ support and shorter ICU length of stay. Conclusions CER-001 shows promise as a therapeutic strategy for sepsis management, improving outcomes and mitigating inflammation and organ damage. Trial registration The study was approved by the Agenzia Italiana del Farmaco (AIFA) and by the Local Ethic Committee (Ndegrees EUDRACT 2020-004202-60, Protocol CER-001- SEP_AKI_01) and was added to the EU Clinical Trials Register on January 13, 2021. Keywords: ApoA-I complexes, Sepsis, Multi-organ dysfunction, Cytokine storm
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Caronia area is located in the Tyrrhenian north-eastern sector of Sicily (Italy). Starting in 2010, attention focused on the study of landslides phenomena that occurred in this area, which caused ...significant economic damage to buildings and infrastructures and loss of productive activities. The site is characterized by geotechnical, geological and morphological heterogeneity, and for this reason the site is particularly prone to seismic topographic amplification effects. In this paper, the authors carried out numerical studies focused on the topographic seismic effect evaluation concerning the slope affected by the landslide phenomena. For this site, geotechnical characterization was available concerning both in-situ and laboratory tests; boreholes, piezometers, down-hole tests, multichannel analysis of surface waves tests, seismic tomographies and inclinometer measurements were carried out. Furthermore, 1-D and 2-D local seismic response analyses were carried out by using different synthetic seismograms related to the earthquake of Messina and Reggio Calabria on 28 December 1908. The results of the numerical analyses are presented in terms of response seismograms and response spectra at the surface.
Flash spark plasma sintering of pure TiB2 Failla, Simone; Fu, Shuai; Sciti, Diletta ...
Open ceramics,
March 2021, 2021-03-00, 2021-03-01, Letnik:
5
Journal Article
Recenzirano
Odprti dostop
Flash Spark Plasma Sintering (FSPS) was used to rapidly sinter pure titanium diboride (TiB2). A pre-sintered sample (Ø = 20 mm with relative density 60%) was crossed under a current of 2–2.5 kA ...flowing entirely across the sample. The samples were locally densified up to 98% of relative density in a very short time of 20 s. The rapid heating (≈6000 °C/min) prevented the complete evaporation of B2O3, leading to the formation of rarely seen segregation of boron at the grain boundaries. Compared to SPS or hot press, the rapid FSPS processing promoted the formation boron rich grain boundaries during sintering, thus enhancing consolidation. The FSPS approach might be suitable to consolidate other refractory borides.
Display omitted
•Titanium diboride was successfully sintered by FSPS in less than 40 s.•The die-less configuration could enable an automated sintering process.•The consolidation was achieved using a low voltage (9 V) and a minimal energy input.•The formation of B liquid phase from B2O3 impurities accelerated the densification.
We report on a novel consolidation technique based on the combination of a liquid (cold sintering) and electricity (flash sintering). The evolution of hydrogen from electrolysis of the solvent ...triggered the Flash Cold Sintering (FCS) event without need for external heating. Electrochemical effects became pronounced in the presence of acetic acid solution as the electrolyte had an increased conductivity compared to pure water. By adjusting the acetic acid molar concentration to 0.5 M and by inverting the polarity during FCS a 5 mm diameter 0.8 mm thick Nb
2
O
5
sample was evenly sintered up to 99% in 100 s at a temperature as low as 350°C. Conventional sintered counterparts achieved a 95% relative density when dwelled for 240 min at 1400°C. The inherent complexity of the proposed FCS approach resulted in enhanced densification and weakly translucent samples.
PDF
