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The appeal of metal halide perovskite solar cells (PSCs) has been widely demonstrated in the field of photovoltaic technology. On account of the excellent optical and electrical properties, as well as compatibility with flexible substrates, the PSCs also hold the highest record of specific power for lightweight solar cell devices, suggesting excellent promise in space applications. Hence, there is increasing interest in the performance of PSCs in space environments where radiation beams and thermal cycling can cause extreme stress on the devices. In this Perspective, we provide a brief summary of the research on PSCs for space applications. The radiation tolerance and thermal stability of PSCs and the fundamental mechanisms are discussed and analyzed. Key challenges facing PSC technology toward future space applications are demonstrated. This Perspective features the prospect of PSCs as the next frontier in space PV technology.

Seed-mediated synthesis strategies, in which small nanoparticle precursors are added to a growth solution to initiate heterogeneous nucleation, are among the most prevalent, simple, and productive methodologies for generating well-defined colloidal anisotropic nanostructures. Here, we identify the majority component in the seed solution as an atomically-precise gold nanocluster, consisting of a 32 atom Au core with 8 halide ligands and 12 neutral ligands constituting a bound ion pair between a halide and the cationic surfactant: Au32X8[AQA+•X-]12 (X = Cl, Br; AQA = alkyl quaternary ammonium). Ligand exchange is dynamic and versatile, occurring on the order of minutes and allowing for the formation of 48 distinct Au32 clusters with AQAX (alkyl quaternary ammonium halide) ligands. Anisotropic nanoparticle syntheses seeded with solutions enriched in Au32X8[AQA+•X-]12 show narrower size distributions and fewer impurity particle shapes, indicating the importance of this cluster as a precursor to the growth of well-defined nanostructures.

Simultaneously improving photovoltaic performance and longevity has become the main focus towards the commercialization of metal halide perovskite solar technology. Herein, we demonstrate resilient, high-efficiency triple-cation perovskite solar cells (PSCs) by incorporating carbon dots (CDs) derived from human hair into the perovskite film synthesis. It is found that a toluene-based antisolvent containing CDs results in the formation of a bilayer structure where a wave-like textured top perovskite layer is assembled on the bottom dense perovskite counterpart, enabling reduced optical losses through light trapping. Further characterization has revealed that the CDs are formed around and over the surface of perovskite crystals, serving as a full armour to preserve the perovskite stoichiometry during the crystallization and operation. Accordingly, the CD-wrapped perovskite film demonstrates a reduced density of interfacial defects including metallic lead clusters and uncoordinated halide vacancies, improved carrier recombination lifetime, better energy alignment with the adjacent hole transport layer, and enhanced hydrophobicity. By leveraging these advantages to enhance the efficiency of PSCs, we have achieved a maximum power conversion efficiency of 20.22%, higher than 18.72% for PSCs without CDs, and the device stability is also significantly enhanced.

Metal halide perovskite materials have demonstrated unique properties for applications in optoelectrical devices such as solar cells, light-emitting diodes and photodetectors. The unprecedented world-record energy conversion efficiency of over 25% achieved with solution-processed perovskite solar cells is escalating research towards the commercialisation of the perovskite materials. Nevertheless, the use of large amounts of hazardous and carcinogenic solvents such as N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and skin-penetrating dimethyl sulfoxide (DMSO) in the current perovskite synthesis protocols are limited for the commercial uptake of perovskite technology as these detrimental solvents can cause environmental, health and safety issues. Therefore, the development of alternative environmentally-friendly, green solvents for the synthesis of perovskite materials including thin films, nanocrystals or single-crystals with desirable properties is critical for the commercialisation of perovskite technologies. In this review, we summarize the research progress of solution-processable perovskite material using low-toxic and green solvent alternatives. We discuss the fundamental properties that need to be considered in screening solvents for the solution processing of metal halide perovskites. By carefully analysing the common features of solvents and anti-solvent systems that have been reported for making perovskite precursor inks for applications in solar cells and light-emitting diodes, we provide insight into the relationship between the solvent molecular ligand – properties of perovskite materials – device performance. We discuss the advantages and challenges of each type of green solvent based on their performance in metal halide perovskite technology, effects on the environment, human health and safety, aiming to provide guidelines towards green metal halide perovskite technology.

A hole transport layer (HTL) plays the role of extracting hole carriers while improving interfacial contacts of perovskite/carbon in planar heterojunction perovskite solar cells using carbon based electrodes (C-PSCs). For the future application of C-PSCs, the HTL also needs to have good stability and easy processability while maintaining high device efficiency. Herein, we compare the behaviour of the most widely used HTL based on spiro-OMeTAD to the much less studied HTL based on CuSCN in planar C-PSCs. The results show that 14.7% power conversion efficiency (PCE) is obtained for CuSCN based C-PSCs with good reproducibility and negligible hysteresis behaviour. In contrast, the C-PSCs using spiro-OMeTAD show a much lower PCE (12.4%) and significant hysteresis phenomenon. We conduct systematic characterisation of the electronic and energetic properties of the C-PSCs to understand this phenomenon. We find that a more favourable energy level alignment of CuSCN with the perovskite than spiro-OMeTAD leads to a reduced charge injection barrier, which favours a more efficient hole extraction capability, inhibited carrier recombination and reduced ionic capacitance. This in turn leads to better PCE and lower hysteresis for the C-PSCs. Moreover, the CuSCN based C-PSCs also demonstrate better stability against moisture with a high PCE retention ratio of 93% under a humid environment (55–70%) for 80 days without encapsulation.

Herein we demonstrate a new method for the synthesis of methylammonium lead bromide perovskite nanocrystals (MAPbBr3) by using environmentally friendly ionic liquids. The effects of different carboxylate anions in ionic liquids on crystal growth and the properties of MAPbBr3were investigated. This work paves a new avenue for the sustainable synthesis of perovskite materials by using ionic liquid based green solvents.

The remarkable evolution of metal halide perovskites in the past decade makes them promise for next-generation optoelectronic material. In particular, nanocrystals (NCs) of inorganic perovskites have demonstrated excellent performance for light-emitting and display applications. However, the presence of surface defects on the NCs negatively impacts their performance in devices. Herein, we report a compatible facial post-treatment of CsPbI

Purpose: This study explores consumers’ perceptions of the Affordable Care Act and its role in facilitating health insurance coverage for all Americans. Moreover, this research also examines how Hispanic consumers along the southern border of the United States and Mexico cope with healthcare related challenges. Design/Methodology: Narrative and observation research methods are employed to understand customers’ experiences and emotions regarding healthcare issues. We first read the excerpts to develop an initial understanding of the participants’ experience about healthcare. Then narrative analysis was conducted to further deconstruct participants’ stories. Findings: Results show that although some Hispanic consumers in the United States hold negative views toward the ACA, they perceive the AHCA as a less favorable alternative. Additionally, the study reveals idiosyncratic coping mechanisms of uninsured Hispanic consumers along the Mexican border. Originality: The study explores new servicescape elements that enhance the services marketing literature related to healthcare.

Published data on the size-specific effective orifice area (EOA) of transcatheter heart valves (THVs) remain scarce. Here, we sought to investigate the intra-individual changes in EOA and mean transvalvular aortic gradient (MG) of the Sapien 3 (S3), CoreValve (CV), and Evolut R (EVR) prostheses both at short-term and at 1-year follow-up. The study sample consisted of 260 consecutive patients with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI). EOAs and MGs were measured with Doppler echocardiography for the following prostheses: S3 23 mm (n = 74, 28.5%), S3 26 mm (n = 67, 25.8%), S3 29 mm (n = 20, 7.7%), CV 23 mm (n = 2, 0.8%), CV 26 mm (n = 15, 5.8%), CV 29 mm (n = 24, 9.2%), CV 31 mm (n = 9, 3.5%), EVR 26 mm (n = 22, 8.5%), and EVR 29 mm (n = 27, 10.4%). Values were obtained at discharge, 1 month, 6 months, and 1 year from implantation. At discharge, EOAs were larger and MGs lower for larger-size prostheses, regardless of being balloon-expandable or self-expandable. In patients with small aortic annulus size, the hemodynamic performances of CV and EVR prostheses were superior to those of S3. However, we did not observe significant differences in terms of all-cause mortality according to THV type or size. Both balloon-expandable and self-expandable new-generation THVs show excellent hemodynamic performances without evidence of very early valve degeneration.

Low‐dimensional‐networked (LDN) perovskites denote materials in which the molecular structure adopts 2D, 1D, or 0D arrangement. Compared to conventional 3D structured lead halide perovskite (chemical formula: ABX3 where A: monovalent cations, B: divalent cations, X: halides) that have been studied widely as light absorber and used in current state‐or‐the‐art solar cells, LDN perovskite have unique properties such as more flexible crystal structure, lower ion transport mobility, robust stability against environmental stress such as moisture, thermal, etc., making them attractive for applications in optoelectronic devices. Since 2014, reports on LDN perovskite materials used in perovskite solar cells, light emitting diodes (LEDs), luminescent solar concentrators (LSC), and photodetectors have been reported, aiming to overcome the obstacles of conventional 3DN perovskite materials in these optoelectronic devices. In this review, the variable ligands used to make LDN perovskite materials are summarized, their distinct properties compared to conventional 3D perovskite materials. The research progress of optoelectronic devices including solar cells, LEDs, LSCs, and photodetectors that used different LDNs perovskite, the roles and working mechanisms of the LDN perovskites in the devices are also demonstrated. Finally, key research challenges and outlook of LDN materials for various optoelectronic applications are discussed.

Background Stroke is a major cause of disability after transcatheter aortic valve replacement (TAVR) and stroke prediction models and data are crucially needed. Following TAVR, high molecular weight (HMW) multimers defect of von Willebrand factor (VWF) as assessed by closure time of adenosine diphosphate (CT-ADP) value > 180 seconds is an independent predictor of bleeding events. This study sought to identify predictors of ischemic neurological events in patients who underwent TAVR and the specific impact of HMW multimers defect of VWF. Methods Patients were prospectively enrolled between November 2012 and May 2018 at our institution. The CT-ADP, a point-of-care measure of hemostasis, was assessed the day before and 24 hours after the procedures. The rate of ischemic stroke and transient ischemic attack (TIA) was recorded up to 30 days after the procedures. Results Of 565 TAVR patients, ischemic stroke/TIA was observed in 21 (3.7%) patients within 30 days. Ischemic stroke/TIA was associated with major/life-threatening bleeding complications (MLBCs) (9 [43%] vs. 88 [16%], p = 0.002) and postprocedure CT-ADP > 180 seconds (10 [48%] vs. 116 [21%], p = 0.01). By multivariate analysis, MLBCs (odds ratio [OR]: 3.58; 95% confidence interval [CI]: 1.45–8.84; p = 0.006) and postprocedure CT-ADP > 180 seconds (OR: 3.38; 95% CI: 1.38–8.25; p = 0.008) were evidenced as independent predictors of ischemic stroke/TIA. Conclusion MLBCs and CT-ADP > 180 seconds were identified as predictors for ischemic stroke or TIA. The present study suggests that the defects of HMW multimers of the VWFs may contribute not only to bleeding events but also to thrombotic events.

BackgroundAlthough cardiovascular disease has been associated with an increased risk of coronavirus disease 2019 (COVID-19), no studies have reported its clinical course in patients with aortic stenosis who had undergone transcatheter aortic valve replacement (TAVR).Several observational studies have found an association between the A blood group and an increased susceptibility to SARS-CoV-2 infection, whereas the O blood group appears to be protective.ObjectiveTo investigate the frequency and clinical course of COVID-19 in a large sample of patients who had undergone TAVR and to determine the associations of the ABO blood group with disease occurrence and outcomes.MethodsPatients who had undergone TAVR between 2010 and 2019 were included in this study and followed-up through the recent COVID-19 outbreak. The main outcomes were the occurrence and severity (hospitalization and/or death) of COVID-19 and their association with the ABO blood group.ResultsOf the 1125 patients who had undergone TAVR, 403 (36%) died before January 1, 2020, and 20 (1.8%) were lost to follow-up. The study sample therefore consisted of 702 patients. Among them, we identified 22 cases (3.1%) with COVID-19. Fourteen patients (63.6%) were hospitalized or died of disease. Multivariate analysis identified the A blood group (versus others) as the only independent predictor of COVID-19 in patients who had undergone TAVR (odds ratio [OR] = 6.32; 95% confidence interval [CI] = 2.11-18.92; p=0.001). The A blood group (versus others; OR = 8.27; 95% CI = 1.83-37.43, p=0.006) and a history of cancer (OR = 4.99; 95% CI = 1.64-15.27, p = 0.005) were significantly and independently associated with disease severity (hospitalization and/or death).ConclusionsPatients who had undergone TAVR are vulnerable to COVID-19. The subgroup with the A blood group was especially prone to develop the disease and showed unfavorable outcomes.Condensed abstractAmong 702 patients who had undergone TAVR between 2010 and 2019 and who were alive on January 1, 2020, 22 patients developed COVID-19. Fourteen patients (63.6%) were hospitalized or died of disease. The A blood group (versus others) was the only independent predictor of COVID-19. The A blood group and a history of cancer were significantly and independently associated with disease severity (hospitalization and/or death). Altogether these findings suggest that patients who had undergone TAVR are vulnerable to COVID-19. The subgroup with the A blood group was especially prone to develop the disease and showed unfavorable outcomes.

BACKGROUND: Periprocedural and late (>30 days) bleedings represent major complications after transcatheter aortic valve replacement and have been identified as potential areas for improved patient care. OBJECTIVES: The authors sought to evaluate the impact of ongoing primary hemostasis disorders on late major/life-threatening bleeding complications (MLBCs). METHODS: Bleedings were assessed according to the VARC-2 (Valve Academic Research Consortium-2) criteria. Closure time of adenosine diphosphate (CT-ADP), a surrogate marker of high molecular weight von Willebrand multimers proteolysis was assessed 24 h after the procedure. Ongoing primary hemostasis disorder was defined by a CT-ADP >180 s. RESULTS: Among 372 patients who survived at 30 days, MLBCs occurred in 42 patients (11.3%) at a median follow-up of 383 days (interquartile range: 188 to 574 days). MLBCs were mainly of gastrointestinal origin (42.8%) and were associated with increased overall mortality (hazard ratio [HR]: 5.66; 95% confidence interval [CI]: 3.10 to 10.31; p < 0.001) and cardiac mortality (HR: 11.62; 95% CI: 4.59 to 29.37; p < 0.001). A 2.5-fold elevation of MLBCs could be evidenced in patients with a CT-ADP > 180 s (27.4% vs. 11.5%; p < 0.001). Multivariate regression analysis identified paravalvular leak (PVL) (HR: 6.31; 95% CI: 3.43 to 11.60; p < 0.0001) and CT-ADP > 180 s (HR: 3.08; 95% CI: 1.62 to 5.81; p = 0.0005) as predictor of MLBCs. CONCLUSIONS: MLBCs after transcatheter aortic valve replacement are frequent and associated with an increased morbidity and mortality. PVL and CT-ADP >180 s were identified as strong predictors for MLBCs. These findings strongly suggest that persistent HMW defects contribute to enhanced bleeding risk in patients with residual PVL.

The halide perovskite nanocrystals (P-NCs) can address a plethora of issues of the light-emission technologies, due to its low temperature processing. To successfully employ P-NCs for light-emitting diodes (LEDs), one needs to resolve the issues of stability of the LEDs. The stability of device can be achieved by charge balance of electrons and holes recombination in active material. To investigate this herein, a self-assembled carbon dots (CDs) layer is fabricated from waste small strands of human hair. The self-assembled CDs layer is used beneath P-NCs layer to reduce the band-off set for hole transport, thus balancing the electron and holes carrier in active layer. The layer is used as an active light-emitting layer to fabricate a LED device that exhibits green luminescence of 4800 cd m−2 at a current efficiency of 10.7 cd A−1 and external quantum efficiency of 4.8%. The LED exhibits operational stability of nearly 200 h. The same film is used to demonstrate a flexible device with maximum luminescence of 2259 cd m−2, with a high current density of 474 mA cm−2, current efficiency of 1.37 cd A−1 and a low turn-on voltage of 3.5 V. All the display devices are measured in air without encapsulation.

A carbon electrode with low cost and high stability exhibited competitiveness for its practical application in organic-inorganic hybrid perovskite solar cells (PSCs). Nonetheless, issues such as poor interface contact with an adjacent perovskite layer and obvious hysteresis phenomenon are bottlenecks that need to be overcome to make carbon-based PSCs (C-PSCs) more attractive in practice. Herein, we report an effective method to enhance the interfacial charge transport of C-PSCs by introducing the CuSCN material into the device. Two types of CuSCN-assisted devices were studied in this work. One was based on the deposition of an ultrathin CuSCN layer between the perovskite absorber layer and the carbon cathode (PSK/CuSCN/C), and the other was by infiltrating CuSCN solution into the carbon film (PSK/C-CuSCN) by taking advantage of the macroporous structure of the carbon. We have found that the CuSCN incorporation by both methods can effectively address the hysteretic feature in planar C-PSCs. The origin for the hysteresis evolution was unraveled by the investigation of the energy alignment and the kinetics of interfacial charge transfer and hole trap-state density. The results have shown that both types of CuSCN-containing devices showed improved interfacial charge carrier extraction, suppressed carrier recombination, reduced trap-state density, and enhanced charge transport, leading to negligible hysteresis. Furthermore, the CuSCN-incorporated C-PSCs demonstrated enhanced device stability. The power conversion efficiency remained 98 and 91% of the initial performance (13.6 and 13.4%) for PSK/CuSCN/C and PSK/C-CuSCN, respectively, after being stored under a high humidity (75-85%) environment for 10 days. The devices also demonstrated extraordinary long-term stability with a negligible performance drop after being stored in air (relative humidity: 33-35%) for 90 days.

Herein we report on integrated photoelectrolysis of water employing organic metal halide (OMH) perovskite material. Generic OMH perovskite material and device architecture are highly susceptible to degradation by moisture and water. We found that decomposition of perovskite devices proceeds by water ingress through pinholes in upper layers and is strongly affected by applied bias/light and electrolyte pH. It was also found that a pinhole-free hole transport layer (HTL) could significantly enhance the stability of the perovskite photoelectrode, thereby extending the photoelectrode lifetime to several tens of minutes, which is an unprecedented record-long operation. Furthermore, a carbon nanotube (CNT)/polymer composite layer was developed that can effectively protect the underlying perovskite layer from electrolyte molecules.

The inclusion of long chain alkyl-amine organics in perovskite solar cells (PSCs) has been reported to enhance water-resistance of perovskite films, but this strategy lowers device efficiency at the same time. Herein, we develop an approach that combines molecular dimensionality control and interfacial passivation of perovskite layers using a novel post-device treatment (PDT) with the vapour of ethylene-amine salts of different carbon chain lengths to improve both efficiency and stability of the PSCs. The effect of a series of ligand vapours including ethylenediamine (EDA), diethylenetriamine (DETA) and triethylenetetramine (TETA) was systematically investigated. A thin hydrophobic two-dimensional (2D) perovskite capping layer formed in the device after the 3D perovskite was exposed to the vapour of long chain ethylene-amine molecules, such as DETA and TETA, which protected the underlying bulk 3D perovskite layer from moisture attack. An improved energy level alignment was obtained in the treated devices and that a reduced density of defects was present in the perovskite after treatment with DETA and TETA vapours. Consequently, enhanced efficiency from 17.07% to 18.09% (DETA) and improved moisture stability with PCE retention from 73.8% to 90.0% (TETA) under a relative humidity>65% for 1000 h were achieved by this vapour treatment respectively.

Metal halide perovskite nanocrystals (PeNCs) are emerging as one of the most promising materials for optoelectrical devices such as light-emitting diode (LED) owing to their tunable band gaps, high color purity, and tolerance to defects. Nevertheless, the materials have not yet demonstrated their full potential in practical applications due to the poor stability of PeNCs and their unsatisfactory performance in devices. In this research, LED devices based on CsPbBr3 NCs are successfully demonstrated as an active light-emitting layer with enhanced efficiency via potassium doping. The study of the effect of potassium dopant on physicochemical properties of inorganic CsPbBr3 PeNCs shows that potassium cations (K+) remain in the crystal structure of perovskite compound as interstitial defects, which results in better coverage of surface ligands on the PeNCs and improved energy band alignment with adjacent electron injection layer (2,2′,2′-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)) and hole injection layer (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) in an LED. As a consequence, the green LED with the K-doped CsPbBr3 PeNCs shows luminance up to 5759 cd m-2 and external quantum efficiency (EQE) of 5.6%, which is superior to the pristine device without K-doping (luminance: 4579 cd m-2, EQE: 4.8%).

A simple yet effective method based on hot-pressing a free-standing carbon film onto adjacent hole transport layer (HTL) is used to fabricate carbon electrode for planar perovskite solar cells (C–PSCs). Due to the thermoplasticity of as-prepared carbon film, the conductivity of the carbon electrode is enhanced by over ten-fold and the adhesion to adjacent layer is dramatically strengthened via this hot-pressing process. By optimizing the pressing temperature, 15.3% of power conversion efficiency (PCE) is obtained for CuSCN based C–PSCs, which is 70% high than the device without heating at the same pressing pressure. The device demonstrates 93% performance retention after being stored in a humid environment (55–70%) without encapsulation over 80 days. This facile fabrication process of PSCs paves a way to facilitate commercialization of the new PV technology.

Environmental instability of Spiro-OMeTAD-based hole transport layer (HTL) caused due to rapid aggregation and hydration of its additive, Lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), gives rise to an accelerated degradation of the resulting perovskite solar cells (PSCs). Herein, we show that replacing the Li-TFSI with the more hydrophobic alkaline-earth bis(trifluoromethanesulfonyl)imide additives, namely Mg-TFSI2 and Ca-TFSI2, can effectively stabilize the coordination complexes between the TFSI-salts and 4-tert-Butylpyridine, which in turn results in retarded additive aggregation and hydration, enabling enhanced moisture-resistance of the subsequent HTLs. Moreover, by manipulating this substitution method, we achieved high-quality HTLs with increased hole mobility, better-formed interface with the adjacent perovskite, allowing improved hole extraction process. Incorporating these HTLs into photovoltaic devices, we obtained a substantial performance improvement, with the champion PSC yielded a power conversion efficiency of over 20%. In addition, un-encapsulated devices stabilized by the alkaline-earth bis(trifluoromethanesulfonyl)imide additive maintained 83% its initial efficiency for 193 days after aging in ambient air (RH% = 55–70%).

Background - Transcatheter aortic valve replacement (TAVR) is standard therapy for patients with severe aortic stenosis who are at high surgical risk. However, national data regarding procedural characteristics and clinical outcomes over time are limited. Objectives - The aim of this study was to assess nationwide performance trends and clinical outcomes of TAVR during a 6-year period. Methods - TAVRs performed in 48 centers across France between January 2013 and December 2015 were prospectively included in the FRANCE TAVI (French Transcatheter Aortic Valve Implantation) registry. Findings were further compared with those reported from the FRANCE 2 (French Aortic National CoreValve and Edwards 2) registry, which captured all TAVRs performed from January 2010 to January 2012 across 34 centers. Results - A total of 12,804 patients from FRANCE TAVI and 4,165 patients from FRANCE 2 were included in this analysis. The median age of patients was 84.6 years, and 49.7% were men. FRANCE TAVI participants were older but at lower surgical risk (median logistic European System for Cardiac Operative Risk Evaluation [EuroSCORE]: 15.0% vs. 18.4%; p < 0.001). More than 80% of patients in FRANCE TAVI underwent transfemoral TAVR. Transesophageal echocardiography guidance decreased from 60.7% to 32.3% of cases, whereas more recent procedures were increasingly performed in hybrid operating rooms (15.8% vs. 35.7%). Rates of Valve Academic Research Consortium-defined device success increased from 95.3% in FRANCE 2 to 96.8% in FRANCE TAVI (p < 0.001). In-hospital and 30-day mortality rates were 4.4% and 5.4%, respectively, in FRANCE TAVI compared with 8.2% and 10.1%, respectively, in FRANCE 2 (p

Due to their superior environmental stability, utilization of low-dimensional perovskites in organometal halide solar cells (OMHSCs) has seen a sharp increase. Herein, a method to form 1D pyrrolidinium lead iodide (PyPbI3) in situ atop photoactive 3D methylammonium lead iodide (MAPbI3) using pyrrolidine posttreatment is reported. As compared with 3D MAPbI3, 1D PyPbI3 has a wider bandgap and is more environmentally stable, and it serves as a tunneling contact to mitigate charge carrier recombination and as a robust barrier against environmental degradation when incorporated into OMHSCs. Accordingly, power conversion efficiencies of the resulting MAPbI3 devices are enhanced from an average of 14.86% ± 0.65% to 15.9% ± 0.58% and their shelf-life stability is significantly prolonged.

International audience; Importance: Low cardiac output syndrome after cardiac surgery is associated with high morbidity and mortality in patients with impaired left ventricular function.Objective: To assess the ability of preoperative levosimendan to prevent postoperative low cardiac output syndrome.Design, setting, and participants: Randomized, double-blind, placebo-controlled trial conducted in 13 French cardiac surgical centers. Patients with a left ventricular ejection fraction less than or equal to 40% and scheduled for isolated or combined coronary artery bypass grafting with cardiopulmonary bypass were enrolled from June 2013 until May 2015 and followed during 6 months (last follow-up, November 30, 2015).Interventions: Patients were assigned to a 24-hour infusion of levosimendan 0.1 µg/kg/min (n = 167) or placebo (n = 168) initiated after anesthetic induction.Main outcomes and measures: Composite end point reflecting low cardiac output syndrome with need for a catecholamine infusion 48 hours after study drug initiation, need for a left ventricular mechanical assist device or failure to wean from it at 96 hours after study drug initiation when the device was inserted preoperatively, or need for renal replacement therapy at any time postoperatively. It was hypothesized that levosimendan would reduce the incidence of this composite end point by 15% in comparison with placebo.Results: Among 336 randomized patients (mean age, 68 years; 16% women), 333 completed the trial. The primary end point occurred in 87 patients (52%) in the levosimendan group and 101 patients (61%) in the placebo group (absolute risk difference taking into account center effect, -7% [95% CI, -17% to 3%]; P = .15). Predefined subgroup analyses found no interaction with ejection fraction less than 30%, type of surgery, and preoperative use of β-blockers, intra-aortic balloon pump, or catecholamines. The prevalence of hypotension (57% vs 48%), atrial fibrillation (50% vs 40%), and other adverse events did not significantly differ between levosimendan and placebo.Conclusions and relevance: Among patients with low ejection fraction who were undergoing coronary artery bypass grafting with cardiopulmonary bypass, levosimendan compared with placebo did not result in a significant difference in the composite end point of prolonged catecholamine infusion, use of left ventricular mechanical assist device, or renal replacement therapy. These findings do not support the use of levosimendan for this indication.Trial registration: EudraCT Number: 2012-000232-25; clinicaltrials.gov Identifier: NCT02184819.