Highly Stable Perovskite Solar Cells Based on the Efficient Interaction between Pb2+ and Cyano Groups of 4-Aminophthalonitrile.

Defects present on the top surface of perovskite films have a pronounced detrimental impact on the photovoltaic performance and stability of perovskite solar cells (PSCs). Consequently, the development of effective defect passivation strategies has become key in enhancing both the power conversion efficiency (PCE) and stability of PSCs. In this study, a small molecule material, 4-Aminophthalonitrile (4-APN), was introduced as a means to mitigate surface defects within perovskite films. Obviously, 4-APN effectively passivates the defects at grain boundaries by combining cyano groups (-C≡N) with Pb2+ , significantly reducing the density of defect states, inhibiting non-radiative recombination at the interface, and promoting the charge transfer efficiency from the perovskite layer to the hole transport layer. The 4-APN modification led to a significant upswing in the PCE, while concurrently bolstering the overall device stability. Importantly, the devices on 4-APN as passivation additive exhibited negligible performance degradation aging for 1200 h.

High-Fill-Factor Perovskite Solar Cells via Pseudohalide Salt Modification of the Substrate to Mitigate Nonradiative Recombination at the Interface.

The utilization of the sol-gel method for fabricating planar SnO2 as the electron transport layer (ETL) induces numerous defects on the SnO2 layer surface and perovskite film bottom, causing considerable deterioration of the device performance. Conventional inorganic salt-doped SnO2 precursor solutions used for passivation may cause incomplete substrate coverage due to the presence of inorganic salt crystals, further degrading the device performance. Here, a substrate modification approach involving the pretreatment of a fluorine-doped SnO2 (FTO) substrate with NH4PF6 is proposed. The interaction between PF6- ions and the FTO substrate enhances SnO2 film quality; excess PF6- ions decrease the number of defects on the film surface. NH4+ ions react with an -OH stabilizing agent in the SnO2 solution and are eliminated during annealing. The combined effects suppress nonradiative recombination and ion migration at the ETL-perovskite interface. The corresponding high-quality perovskite solar cells (PSCs) exhibit a fill factor of ∼0.825; PSC efficiency increases from 19.59% to 22.32%.

Enhancing the Efficiency of Perovskite Solar Cells by Bidirectional Modification of the Perovskite and Electron Transport Layer.

In perovskite solar cells (PSCs), the numerous defects present on the surface of the SnO2 electron transport layer (ETL) and the bottom of the perovskite film limit their power conversion efficiency (PCE) and stability. In view of this, a bidirectional modification strategy is designed using formamidine acetate (FAAc) to passivate the defects on the SnO2 ETL surface and bottom of the perovskite simultaneously. FA+ cations act on the harmful hydroxyl groups on the SnO2 ETL surface, whereas Ac- anions act on the iodine vacancy defect at the bottom of the perovskite. Because the interface defect is well passivated by FAAc, the interfacial charge recombination is restrained. This results in a significant increase in the filling factor of the PSC to ∼0.83 and the consequent increase in PCE to 23.05%, which considerably improves the stability. Bidirectional modification technology is an effective strategy for improving the PCE and stability of PSCs.

Defect management by a cesium fluoride-modified electron transport layer promotes perovskite solar cells.

SnO2 is a candidate material for electron transport layers (ETLs) in perovskite solar cells (PSCs). However, a large number of defects at the SnO2/perovskite interface lead to notable non-radiative interfacial recombination. Moreover, the energy level arrangement between SnO2/perovskite does not match well. In this study, a SnO2/CsF-SnO2 double-layer ETL was prepared by doping CsF into SnO2, effectively passivating the defects of the SnO2 ETL and SnO2/perovskite interface. The formation of a good energy level arrangement with the perovskite layer reduces the interface non-radiative recombination and improves the performance of the interface charge extraction. The photoelectric conversion efficiency of the optimal CsF-modified PSC reached 22.18%, owing to the significant increase in the open-circuit voltage to 1.180 V.

Prognostic Value of Systemic Immune-Inflammation Index among Critically Ill Patients with Acute Kidney Injury: A Retrospective Cohort Study.

Inflammation plays a significant role in the occurrence and development of acute kidney injury (AKI). Evidence regarding the prognostic effect of the systemic immune-inflammation index (SII) in critically ill patients with AKI is scarce. The aim of this study was to assess the association between SII and all-cause mortality in these patients. Detailed clinical data were extracted from the Medical Information Mart for Intensive Care Database (MIMIC)-IV. The primary outcome was set as the in-hospital mortality. A total of 10,764 AKI patients were enrolled in this study. The restricted cubic splines analyses showed a J-shaped curve between SII and the risk of in-hospital and ICU mortality. After adjusting for relevant confounders, multivariate Cox regression analysis showed that both lower and higher SII levels were associated with an elevated risk of in-hospital all-cause mortality. A similar trend was observed for ICU mortality. In summary, we found that the SII was associated in a J-shaped pattern with all-cause mortality among critically ill patients with AKI. SII appears to be have potential applications in the clinical setting as a novel and easily accessible biomarker for predicting the prognosis of AKI patients.

Efficient and Stable Perovskite Solar Cells via CsPF6 Passivation of Perovskite Film Defects.

Polycrystalline perovskite films have many fatal defects; defect passivation can improve the performance of perovskite solar cells (PSCs). In this study, the defects in perovskite films are passivated by introducing the pseudohalide salt CsPF6 into the films. Because the ionic radii of Cs+ and PF6- are close to those of FA+ and I-, respectively, they can be uniformly doped into perovskite films to passivate the bulk, surface, and grain boundary defects. The photovoltaic performance of the PSCs significantly improved after passivation. Moreover, the photoelectric conversion efficiency increased significantly from 21.36% to 23.15% after passivation. Because of defect passivation, PSCs also exhibit good environmental stability. This study introduces a scheme for improving the photovoltaic performance of PSCs via passivation.

Identification of Signature Genes and Construction of an Artificial Neural Network Model of Prostate Cancer.

This study aimed to establish an artificial neural network (ANN) model based on prostate cancer signature genes (PCaSGs) to predict the patients with prostate cancer (PCa). In the present study, 270 differentially expressed genes (DEGs) were identified between PCa and normal prostate (NP) groups by differential gene expression analysis. Next, we performed Metascape gene annotation, pathway and process enrichment analysis, and PPI enrichment analysis on all 270 DEGs. Then, we identified and screened out 30 PCaSGs based on the random forest analysis and constructed an ANN model based on the gene score matrix consisting of 30 PCaSGs. Lastly, analysis of microarray dataset GSE46602 showed that the accuracy of this model for predicating PCa and NP samples was 88.9 and 78.6%, respectively. Our results suggested that the ANN model based on PCaSGs can be used for effectively predicting the patients with PCa and will be helpful for early PCa diagnosis and treatment.

Electron Transport Assisted by Transparent Conductive Oxide Elements in Perovskite Solar Cells.

Fluorine and indium elements in F-doped SnO2 (FTO) and Sn-doped In2 O3 (ITO), respectively, significantly contribute toward enhancing the electrical conductivity of these transparent conductive oxides. In this study, fluorine was combined with indium to modify the SnO2 electron transport layer (ETL) through InF3 . Consequently, the modified perovskite solar cells (PSCs) showe the favorable alignment of energy levels, improved absorption and utilization of light, enhanced interfacial charge extraction, and suppressed interfacial charge recombination. After InF3 modification, the open circuit voltage (Voc ) and fill factor (FF) of the PSC were significantly improved, and the photoelectric conversion efficiency (PCE) reached 21.39 %, far exceeding that of the control PSC (19.62 %).

Precursor Engineering of the Electron Transport Layer for Application in High-Performance Perovskite Solar Cells.

The electron transport layer (ETL) is a key component of regular perovskite solar cells to promote the overall charge extraction efficiency and tune the crystallinity of the perovskite layer for better device performance. The authors present a novel protocol of ETL engineering by incorporating a composition of the perovskite precursor, methylammonium chloride (MACl), or formamidine chloride (FACl), into SnO2 layers, which are then converted into the crystal nuclei of perovskites by reaction with PbI2 . The SnO2 -embedded nuclei remarkably improve the morphology and crystallinity of the optically active perovskite layers. The improved ETL-to-perovskite electrical contact and dense packing of large-grained perovskites enhance the carrier mobility and suppress charge recombination. The power conversion efficiency increases from 20.12% (blank device) to 21.87% (21.72%) for devices with MACl (FACl) as an ETL dopant. Moreover, all the precursor-engineered cells exhibit a record-high fill factor (82%).

Enhanced crystallization of solution-processed perovskite using urea as an additive for large-grain MAPbI3perovskite solar cells.

Perovskite crystal quality plays an important role in perovskite solar cells, given that multiple grain boundaries and trap states in the perovskite films hamper further enhancement of solar cell efficiency. Using the solution method to prepare perovskite films with large grains and high coverage requires further improvements. Herein, we introduce Lewis base urea as an additive into the precursor of perovskite to control the crystallization dynamics, allowing for large-grain crystal growth. As a result, MAPbI3films with urea as an additive are well crystallized with large crystal grains of sizes >3µm. The large-grain perovskite is found to simultaneously improve the power-conversion efficiency (PCE) and device stability. With an optimal urea additive of 20 mol%, the PCE is significantly increased from 15.47% for the reference MAPbI3solar cell to 18.53% for the device with MAPbI3with urea as an additive. Finally, the optimized device demonstrates excellent stability and maintains 80% of the initial PCE after 60 days.

A sandwich-like electron transport layer to assist highly efficient planar perovskite solar cells.

Co-modification of an electron transport layer (ETL) with metal oxides and organic molecules can optimize the structure of the ETL and improve the performance of perovskite solar cells (PSCs). Here, a sandwich-structured ETL consisting of MgO/SnO2/EA was designed by co-modifying a SnO2 ETL with magnesium oxide (MgO) and ethanolamine (EA). The device with an ETL modified with MgO and EA has excellent performance in enhancing electron transport and blocking holes. It also inhibits the formation of deep defect states and improves the stability of the device. The introduction of MgO effectively improves the open-circuit voltage (VOC) of the device, while EA increases the short-circuit current density (JSC). The optimal efficiency of the PSC using the ETL co-modified with MgO and EA is 20.23%, which is much higher than that of the device with the unmodified SnO2 ETL (17.94%). The method described here provides an effective way to develop high performance ETLs co-modified with metal oxides and organic compounds for perovskite-based optoelectronic devices.

Correlation of Caveolin-1 With Vascular Intimal Thickness for Different Locations of Catheter Tips in a Dog Model.

INTRODUCTION: Many studies have reported increased intimal thickness around the catheter tip after catheterization. Caveolin-1 is a protein in the endothelial cell that acts as a shear sensor causing vascular remodeling. This study aimed to elucidate the suitability of different catheter locations and determine the role of caveolin-1 in canine models. MATERIALS AND METHODS: Tunneled silicone 14.5-F catheters were inserted into the left jugular vein and right femoral vein in 8 dogs. The dogs were separated into 2 groups by catheter location and were followed up for 28 days. All dogs underwent extracorporeal circulation 3 times a week. After animal sacrifice, histological and immunohistochemical assays were performed to measure specific cell populations. RESULTS: There were higher catheter dysfunction rates and lower blood flow rates in the right femoral vein group compared to the left jugular vein group. There was intimal hyperplasia around the catheter tip in both groups with no significant difference between the two groups. There were caveolin-1 expression in the intimal layer of venous wall around the catheter tip location sites in both groups. CONCLUSIONS: These findings indicate that different catheter tip locations may influence catheter function and specific targeting of caveonlin-1 could be a strategy of possible future novel therapies for catheter-related vein stenosis.

MTHFR gene C677T polymorphism and type 2 diabetic nephropathy in Asian populations: a meta-analysis.

BACKGROUND: Many studies have suggested a correlation between the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene and diabetic nephropathy (DN), but their results are inconclusive. METHODS: To confirm this correlation, we performed a meta-analysis of 15 studies. The dichotomous data are presented as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: The results of this study suggested that the MTHFR 677 T allele was more likely to increase the risk of DN in Asian (OR = 1.466, 95% CI = 1.143-1.880, P = 0.003), West Asian (OR = 1.750, 95% CI = 1.150-2.664, P = 0.009), and Chinese populations (OR = 2.162, 95% CI = 1.719-2.719, P = 0.001), but not in East Asian or Japanese populations. The carriers of the MTHFR 677 T allele were associated with progression of DN in the "5-10 year duration" group, but not in the "> 10 year duration" group (OR = 2.187, 95% CI = 1.787-2.677, P = 0.001). CONCLUSION: Development of DN is associated with MTHFR C677T polymorphisms in Asian populations, especially in early type 2 diabetes.

Effects of wall shear stress in venous neointimal hyperplasia of arteriovenous fistulae.

AIM: An arteriovenous fistulae (AVF) is the preferred vascular access for maintenance haemodialysis patients. Its dysfunction is often due to venous stenosis, which is mainly caused by neointimal hyperplasia. Additionally, haemodynamic forces, especially wall shear stress (WSS), as a mechanical stimuli to venous wall have a significant role in neointimal hyperplasia. The purpose of this study was to evaluate the association between WSS and neointimal hyperplasia. METHODS: An 'end-to-side' AVF was created between the right femoral artery and vein of canines. Canines were killed at 7 and 28 days post-surgery. The velocity and WSS in the three-dimensional computational model of AVF were simulated using computational fluid dynamics (CFDs). The four typical sites of the vein evaluated in this study, chosen according to the haemodynamic analysis, included the arteriovenous anastomosis (A-V), the juxta-anastomotic segment (J-V), the juxta-ligation segment (L-V) and the proximal vein (P-V). The specimens were haematoxylin-eosin stained and the intima-media thickening was then measured. RESULTS: Neointimal hyperplasia was more obvious in the inner wall of the J-V and L-V (low-and-disturbed WSS) sites compared with the P-V and A-V sites, and the outer wall of the L-V and J-V segments (high or laminar WSS) (P < 0.01). CONCLUSION: In this study, we described the haemodynamic condition in the AVF and found that neointimal hyperplasia predisposed to occur in the inner wall of venous segment near the anastomosis. We also found that not only the neointimal hyperplasia has a strong inverse correlation with WSS levels, but also is related to flow patterns.

Design of an expert system for the development and formulation of push-pull osmotic pump tablets containing poorly water-soluble drugs.

The purpose of this article was to build an expert system for the development and formulation of push-pull osmotic pump tablets (PPOP). Hundreds of PPOP formulations were studied according to different poorly water-soluble drugs and pharmaceutical acceptable excipients. The knowledge base including database and rule base was built based on the reported results of hundreds of PPOP formulations containing different poorly water-soluble drugs and pharmaceutical excipients and the experiences available from other researchers. The prediction model of release behavior was built using back propagation (BP) neural network, which is good at nonlinear mapping and learning function. Formulation design model was established based on the prediction model of release behavior, which was the nucleus of the inference engine. Finally, the expert system program was constructed by VB.NET associating with SQL Server. Expert system is one of the most popular aspects in artificial intelligence. To date there is no expert system available for the formulation of controlled release dosage forms yet. Moreover, osmotic pump technology (OPT) is gradually getting consummate all over the world. It is meaningful to apply expert system on OPT. Famotidine, a water insoluble drug was chosen as the model drug to validate the applicability of the developed expert system.