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We report multinary CuZn2AS x Se4-x semiconductor nanocrystals in a wurtzite phase, achieved via hot-injection synthesis. These nanocrystals exhibit a tunable bandgap and photoluminescence in the visible range. We employ density functional theory and virtual crystal approximation to reveal the bandgap trends influenced by the main group metals and S/Se alloying.
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Interfacial modification is vital to boost the performance of colloidal quantum-dot light-emitting diodes (QLEDs). We introduce phenethylammonium bromide (PEABr) as an interlayer to reduce the trap states and exciton quenching at the interface between the emitting layer (EML) with CdSe/ZnS quantum-dots and the electron transport layer (ETL) with ZnMgO. The presence of PEABr separates the EML and the ETL and thus passivates the surface traps of ZnMgO. Moreover, the interfacial modification also alleviates electron injection, leading to more improved carrier injection balance. Consequently, the external quantum efficiency of the PEABr-based red QLED reached 27.6%, which outperformed those of the previously reported devices. Our results indicate that the halide ion salts are promising to balance charge carrier injection and reduce exciton quenching in the QLEDs.
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Air stability is a big challenge for inverted perovskite solar cells (IPVSCs). We focus on effect of a cathode interlayer (BCP or TOASiW12) on air degradation of IPVSCs with an Al or Ag cathode. Combined measurements have been carried out to check the changes of the device electrical performance with exposure to air. Our results demonstrated that the IPVSCs with BCP/Al suffered an overall deterioration in terms of dissociation of excitons, transport, and extraction of charge carriers, which was accompanied by improved trap density and serious trap-induced recombination when exposed to air. Instead, all the electrical characteristics of the IPVSCs with TOASiW12/Al, BCP/Ag and TOASiW12/Ag remained stable or slightly reduced after exposed to air over 2 days. This work provides new insight into the air aging of IPVSCs and facilitates the development of CIL materials for cost-effective IPVSCs.
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@#Objective To explore the correlation between perioperative blood transfusion and acute kidney injury (AKI) after heart transplantation. Methods A retrospective study was performed on 67 patients who underwent heart transplantation in the Department of Cardiac Surgery, Guangdong Provincial People's Hospital from January 2016 to December 2018, and finally 63 patients were included according to the exclusion criteria. There were 53 males and 10 females with an average age of 44.3±12.9 years. Twenty patients who adopted continuous renal replacement therapy (CRRT) after heart transplantation were divided into a RT group and the other 43 patients who did not use CRRT were divided into a non-RT group. Baseline characteristics, perioperative blood transfusion data and clinical prognosis were compared between the two groups. Results The preoperative baseline characteristics of the two groups were basically the same. There were significant differences in perioperative infusion of red blood cells and plasma, postoperative 24 h bleeding and re-exploration (P<0.05) between the two groups. The area under the receiver operating characteristic (ROC) curve was 0.923 (95%CI 0.852 to 0.995, P<0.001). The ROC curve showed that perioperative infusion of red blood cells more than 18 mL/kg would increase the incidence of AKI after heart transplantation. Conclusion Perioperative blood transfusion is closely related to AKI after heart transplantation. The more blood transfusion is in clinics, the higher incidence of renal injury is and the worse prognosis is. It is suggested that various blood-saving measures can be carried out.
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@#Objective To analyze the assessment and maintenance of 125 donor hearts from brain death donation and explore the use of marginal donor hearts. Methods A retrospective analysis was conducted on the evaluation, maintenance, operation and follow-up results of 125 donor hearts from April 2016 to August 2019. There were 98 males and 27 females at age of 6-50 (36.0±2.4) years. Results Twelve donor hearts were discarded due to unqualified evaluation after heart harvest. 113 patients of heart transplantation were performed with a double lumen venous anastomosis manner. The mean time of cold ischemia was 220.1±6.7 min. Four patients died within 30 days after operation. Postoperative right ventricular assist circulation was performed in 4 patients, intra-aortic balloon counterattack (IABP) in 12 patients and extracorporeal membrane oxygenation (ECMO) in 12 patients. Marginal donors included 15 hepatitis B antigen positive donor hearts, 2 tricuspid regurgitation, 1 mitral regurgitation, 5 coronary calcification, 4 myocardial stunning and 2 severe weight mismatch. The results of follow-up (2 years) after marginal donor heart transplantation were satisfactory. Conclusion Improving the assessment and maintenance of donor hearts can improve the utilization rate of the heart, and the marginal donor heart transplantation needs long-term follow-up.
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@#Objective To evaluate the efficacy of a combination of beating-heart minimally invasive approach and leaflets augmentation technique treating severe tricuspid regurgitation (TR) after cardiac surgery. Methods From January 2015 to August 2017, patients undergoing reoperative tricuspid valve repair (TVP) with minimally invasive approach and leaflets augmentation were enrolled. Cardiopulmonary bypass (CPB) was established via femoral vessels and the procedures were performed on beating heart with normothermic CPB. A bovine pericardial patch was sutured to leaflets to augment the native anterior and posterior leaflets. Other repair techniques, such as ring implantation and leaflet mobilization, were also applied as needed. Results A total of 28 patients (mean age 55.6±10.1 years, 5 males, 23 females) were enrolled. One patient was converted to median sternotomy due to pleural cavity adhesion. Twenty-seven patients underwent totally endoscopic TVP with leaflets augmentation. No patients was transferred to tricuspid valve replacement. Two patients died in hospital. All patients were followed up for 7.4±5.0 months and there was no late death and reoperation. Regurgitation area was converted from 20.7±10.1 cm2 to 3.3±3.3 cm2 after TVP according to the latest echocardiography (P<0.001). Conclusion Minimally TVP with leaflets augmentation is effective in treating severe isolated TR after primary cardiac surgery. It can significantly increase success rate of tricuspid valvuloplasty and decrease the surgical trauma.
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@#Objective To retrospectively reviewed our experience of the surgical and perioperative treatment of patients suffering from critical Marfan syndrome with severe left ventricular dysfunction and to evaluate its therapeutic effect and prognosis. Methods Between January 2012 and October 2016, 15 patients diagnosed with Marfan syndrome combined with severe left ventricular dysfunction (left ventricular ejection fraction≤40% or left ventricular end diastolic diameter≥75 mm) underwent operations for aortic root aneurysm in Zhujiang Hospital and Guangdong General Hospital. Among them, 11 were males and 4 were females with a mean age of 32.9±8.7 years ranging from 19 to 55 years. Five patients with aortic dissection underwent Bentall procedure and total arch reconstruction with stent graft implantation. Two patients underwent Bentall procedure and hemi-arch replacement, seven patients underwent Bentall procedure and one patient underwent Cabrol procedure. Concomitant procedures included mitral valve repair in 12 patients, mitral valve replacement in 3 patients and tricuspid valve repair in 12 patients. Results There were 11 patients (73.3%) receiving intra-aortic balloon pumping implantation. One (6.7%) in-hospital death occurred. The left ventricular end diastolic diameter decreased from 80.5±7.4 mm to 58.3±6.0 mm (P<0.05) and the left ventricular ejection fraction improved from 37.3%±5.2% to 46.3%±4.4% 3 months postoperatively (P<0.05). The left ventricular end diastolic diameter decreased from 80.5±7.4 mm to 53.7±3.6 mm (P<0.05) and the left ventricular ejection fraction improved from 37.3%±5.2% to 57.7%±4.2% after one year (P<0.05). No death and reoperation occurred in the follow-up. Conclusion Although the patients with Marfan syndrome and severe left ventricular dysfunction usually have a high surgical mortality, the key to satisfactory outcomes of severe Marfan syndrome is adequate preoperative preparation, complete correction of all vascular lesions during the operation, application of circulatory auxiliary device and perioperative strict and long-term ICU monitoring.