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Weaning individuals from mechanical ventilation (MV) is a challenge to physicians. Respiratory failure is the main reason for weaning failure (WF), but heart failure plays a pivotal role as well. Transesophageal Doppler (TED) is a minimally invasive method of hemodynamic tracking with fewer problems. The study authors evaluated the role of TED in predicting WF. An observational study. A university teaching hospital. Weaning individuals. TED was applied before initiating the spontaneous breathing trial (SBT). Hemodynamic parameters, arterial blood gases, and TED (peak velocity [PV], cardiac output [COP]) were reported while cases were on MV before initiating the SBT, and at the successful completion of SBT. Succeeded (group S) and failed individuals (group F, who needed reintubation within 48 hours) were compared. The sensitivity, specificity, and area under the receiver operating curve were calculated. A subgroup of patients with cardiac comorbidities and impaired cardiac contractility was further analyzed. The authors included 39 critically ill patients for weaning from MV. The reintubation rate was 54.8%. In patients with cardiac morbidity, delta change (dC) in PV and COP as predictors of WF showed 100% sensitivity and specificity, with 18% and 14% cut-offs after initiating the SBT (dC between the beginning and end of the successful SBT), respectively. Central venous oxygen saturation revealed a significant difference between patients with cardiac morbidity and noncardiac patients with lower sensitivity and specificity in the prediction of WF. TED could be a helpful method for the weaning of patients with cardiac morbidity from MV. The dC in PV and COP >18% and >14% were significant predictors of WF in these subjects, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various CB-SiO 2 composite counter electrodes were prepared by successive printing technique. • CB-SiO 2 composite counter electrodes were applied as Pt-free CEs in liquid-based dye-sensitized solar cells. • CB-SiO 2 composite counter electrodes exhibits catalytic activity compared with Pt CE. • The efficiency of assembled DSSC with CB-SiO 2 -1% composite counter electrodes was 7.99%, which is close to that achieved by Pt-based device. Platinum (Pt)-based counter electrodes (CEs) are promising electrocatalysts for dye-sensitized solar cells (DSSCs). However, replacing the expensive Pt with low-cost materials and comparable catalytic activity still a big challenge. Here, we prepared CB-SiO 2 composites by blending various weights of SiO 2 (1, 3, and 5 wt%) with carbon black (CB), followed by screen printed onto the FTO substrate to utilized as CEs for DSSCs. In comparison with pure CB, CB-SiO 2 composite CEs showed higher transferability and higher electrocatalytic activity toward I 3 - / I - redox couple. Among all, CB-SiO 2 -1% composite CE with 4 µm showed the best catalytic performance, and the related DSSC showed a power conversion efficiency of 6.38%. Increasing the CE thickness significantly enhances the catalytic ability and the total performance of the assembled devices, whereas the power conversion efficiency of the DSSC with CB-SiO 2 -1% composite CE in 8 µm thick was 7.99%, which is close to that achieved by Pt-based device under the same conditions. [ABSTRACT FROM AUTHOR]

Cardiac surgery for repair of congenital heart defects poses unique hazards to the developing brain. Deep hypothermic circulatory arrest (DHCA) is a simple and effective method for facilitating a bloodless surgical field during congenital heart defect repair. There are, however, some concerns that prolonged DHCA increases the risk of nervous system injury. The electroencephalogram (EEG) is used in adult and, to a lesser extent, pediatric cardiac procedures as a neuromonitoring method. The present study was performed to assess outcomes following DHCA with EEG monitoring in the pediatric population. In this systematic review and meta-analysis, the PubMed, Cochrane Central Register of Controlled Trials, Scopus, Institute of Science Index, and Embase databases were searched from inception for relevant articles. A fixed- or random-effects model, as appropriate, was used. Surgical setting. Pediatric population (≤18 y old). DHCA (18°C) with EEG monitoring. Nineteen articles with 1,267 pediatric patients ≤18 years were included. The event rate of clinical and EEG seizures among patients who underwent DHCA was 12.9% and 14.9%, respectively. Mortality was found to have a 6.3% prevalence. A longer duration of DHCA was associated with a higher risk of EEG seizure and neurologic abnormalities. In addition, seizures were associated with increased neurologic abnormalities and neurodevelopmental delay. EEG and neurologic abnormalities were common after DHCA. A longer duration of DHCA was found to lead to more EEG seizure and neurologic abnormalities. Moreover, EEG seizures were more common than clinical seizures. Seizures were found to be associated with increased neurologic abnormalities and neurodevelopmental delay. [ABSTRACT FROM AUTHOR]

[Display omitted] • MoS 2 /NC displays as a core like successfully prepared via solvothermal method. • Blending small portions of MoS 2 /NC composite significantly enhancing the catalytic activity of PEDOT: PSS composite CEs toward I 3 - / I - and [Co (bpy) 3 ]2+/3+ redox mediators due to the synergistic effect. • The MoS 2 /NC-PEDOT: PSS composite CEs are transparent in visible range, the power conversion efficiency of the assembled bi-facial DSSCs under the front and the rear irradiation are close to those with Pt CEs. A few-layered MoS 2 successfully grown on the nitrogen-doped carbon (NC) derived from zeolitic imidazolate framework (ZIF-8) via the hydrothermal method. A small portions of the obtained MoS 2 /NC composite blended with Poly (3, 4-ethylenedioxythiophene poly styrene sulfonic acid)PEDOT: PSS(as a conductive binder and utlized as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The spin-coated MoS 2 /NC-PEDOT: PSS composite on Fluorine-doped Tin Oxide (FTO) glass not only possesses promissing catalytic ability toward the I 3 - / I - and [Co(bpy) 3 ]2+/3+ redox mediators but also displayed considerable optical transparency in the visible range thus used to fabricate bi-facial DSSCs. The assembled bi-facial devices with MoS 2 /NC-PEDOT: PSS composite CEs showed an excellent power conversion efficiency (PCE) under both the front and the rear irradiations. The PCE of the device with 5% MoS 2 /NC-PEDOT: PSS composite CE and I 3 - / I - redox couple are 7.67 and 4.54%, under the front and rear irradiation respectively. Also, the values of the device with the same composite CE and [Co(bpy) 3 ]2+/3+ redox mediator are 7.87 and 5.34% under the front and rear irradiation, respectively. The optimum performance of the devices with the prepared CEs and both redox systems are comparable with Pt-based devices. Thus, the MoS 2 /NC-PEDOT: PSS composite CEs are recommend being a promising Pt-free CEs for DSSCs. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Si 3 N 4 /MoS 2 novel composite was synthetized by one step hydrothermal method. • The morphological and crystallographic structure of obtained Si 3 N 4 /MoS 2 composite was studied. • Si 3 N 4 /MoS 2 /PEDOT: PSS composite were applied as Pt-free CEs in bifacial DSSCs applications. • The front PCE of 5% Si 3 N 4 /MoS 2 /PEDOT: PSS based cell was 7.16% and 2.03% from rear irradiation. Abstract Si 3 N 4 /MoS 2 nanocomposite has been fabricated through a solvothermal process and Mixed with polystyrenesulfonate-doped poly (3, 4-ethylenedioxythiophene) to prepare (Si 3 N 4 /MoS 2 -PEDOT: PSS) as a counter electrode (CE) for bifacial dye-sensitized solar cells (DSSCs). The electrochemical studies confirm that Si 3 N 4 /MoS 2 -PEDOT: PSS CEs exhibits higher catalytic activity compared with pristine Si 3 N 4 /MoS 2 and PEDOT: PSS. The DSSCs with 5% Si 3 N 4 /MoS 2 -PEDOT: PSS composite CE achieves conversion efficiency (PCE) of 7.16%, which is comparable to that of the conventional platinum CE (7.50%) and better than those of the pristine Si 3 N 4 /MoS 2 (3.80%) or PEDOT: PSS (4.20%) CEs. Owing to the optical transparency of Si 3 N 4 /MoS 2 -PEDOT: PSS composite CEs, bifacial DSSCs based on 5% Si 3 N 4 /MoS 2 -PEDOT: PSS CE yield 2.03% PCE from rear irradiation. The simple preparation method, high catalytic activity and electrochemical stability demonstrate that Si 3 N 4 /MoS 2 -PEDOT: PSS can be used a transparent CE in bifacial DSSCs. [ABSTRACT FROM AUTHOR]