Preventing lead leakage in perovskite solar cells and modules with a low-cost and stable chemisorption coating.

Despite the promising commercial prospects of perovskite solar cells, the issue of lead toxicity continues to hinder their future industrial applications. Here, we report a low-cost and rapidly degraded sulfosuccinic acid-modified polyvinyl alcohol (SMP) coating that prevents lead leakage and enhances device stability without compromising device performance. Even under different strict conditions (simulated heavy rain, acid rain, high temperatures, and competing ions), the coatings effectively prevent lead leakage by over 99%. After 75 days of outdoor exposure, the coating still demonstrates similar lead sequestration efficiency (SQE). In addition, it can be applied to different device structures (n-i-p and p-i-n) and modules, with over 99% SQE, making it a general method for preventing lead leakage.

Ionic Bonding Without Directionality Facilitates Efficient Interfacial Bridging for Perovskite Solar Cells.

Interface passivation through Lewis acid-base coordinate chemistry in perovskite solar cells (PSCs) is a universal strategy to reduce interface defects and hinder ion migration. However, the formation of coordinate covalent bonding demands strict directional alignment of coordinating atoms. Undoubtedly, this limits the selected range of the interface passivation molecules, because a successful molecular bridge between charge transport layer and perovskite bottom interface needs a well-placed molecular orientation. In this study, it is discovered that potassium ions can migrate to the hollow sites of multiple iodine ions from perovskite to form K-Ix ionic bonding, and the ionic bonds without directionality can support molecular backbone rotation to facilitate polar sites (carboxyl groups) chelating Pb at the bottom perovskite interface, finally forming a closed-loop bonding structure. The synergy of coordinate and ionic bonding significantly reduces interface defects, changes electric field distribution, and immobilizes iodine at the perovskite bottom interface, resulting in eliminating the hysteresis effect and enhancing the performance of PSCs. As a result, the corresponding devices achieve a high efficiency exceeding 24.5% (0.09 cm2 ), and a mini-module with 21% efficiency (12.4 cm2 ). These findings provide guidelines for designing molecular bridging strategies at the buried interface of PSCs.

Stable Inorganic Colloidal Tin and Tin-Lead Perovskite Nanocrystals with Ultralong Carrier Lifetime via Sn(IV) Control.

Inorganic tin (Sn) perovskite nanocrystals offer a promising solution to the potential toxicity concerns associated with their established lead (Pb)-based counterparts. Yet, achieving their superior stability and optoelectronic properties remains an ongoing challenge. Here, we report a synthesis of high-symmetry α-phase CsSnI3 nanocrystals with an ultralong 278 ns carrier lifetime, exceeding previous benchmarks by 2 orders of magnitude through meticulous Sn(IV) control. The nanocrystals demonstrate excellent colloidal stability, uniform monodispersity, and a distinct exciton peak. Central to these outcomes is our designed solid-liquid antioxidation suspension of tri-n-octylphosphine (TOP) and zerovalent tin (Sn(0)) that fully addresses the unique coexisting oxygen-driven and solvent-driven Sn oxidation mechanisms in Sn perovskite nanocrystal synthesis. We uncover the largely undervalued function of TOP in mitigating oxygen-driven Sn oxidation and introduce Sn(0) powder to generate a synergistic antioxidation function with TOP, significantly reducing Sn(IV)-induced defects and distortions and contributing to enhanced optoelectronic properties. Strikingly, this approach also profoundly impacts inorganic Sn-Pb perovskite nanocrystals, boosting lifetimes by 2 orders of magnitude and increasing photoluminescence quantum yield over 100-fold to 35%. Our findings illuminate the potential of Sn-based nanocrystals for optoelectronic applications.

Drumhead surface states promoted hydrogen evolution reactions in type-II nodal-line topological catalyst Mg3Bi2.

An excellent catalyst generally meets three indicators: high electron mobility, high surface density of states and low Gibbs free energy (ΔG) [H. Luo et al. Nat. Rev. Phys., 2022, 4, 611-624]. Recent studies have confirmed that topological materials exhibit more advantages than conventional precious metals with regard to the above-mentioned indicators. Herein, based on DFT calculations and symmetry analysis, we discovered for the first time that the topological surface states of Mg3Bi2 with a Kagome lattice promote hydrogen evolution reactions (HERs). In particular, there exists a snake-like type-II nodal loop (NL), located on kz = 0 plane in Mg3Bi2. Besides, the NL forms a topologically protected drumhead surface state on the (001) surface. It was found that the ΔG (0.176 eV) value of the (001) surface is comparable to that of the precious metal Pt. Then, through hole doping and strain regulation, it was found that the catalytic activity of Mg3Bi2 is closely related to the drumhead surface state formed by NL. With the above-mentioned results, this study not only provides a promising candidate material for hydrogen electrolysis, but also deepens our understanding of the dominant factors of NL semimetals for the catalytic activity.

Spontaneous healing of complicated crown-root fractures in children: Two case reports.

BACKGROUND: Complicated crown-root fracture is considered a severe dental trauma and is unlikely to heal without treatment. Usually, dentists have to remove the loose coronal fragment of the fractured tooth and treat the remaining part with multidisciplinary approaches. However, we observed spontaneous healing of fracture in two pediatric cases with a history of complicated crown-root fractures over 4 years ago. CASE SUMMARY: In case 1, a 12-year-old boy complained of pain at tooth 11 following an accidental fall 1 d ago. Clinical examination showed a crack line on the crown of tooth 11. Cone beam computed tomography (CBCT) images of tooth 11 showed signs of hard tissue deposition between the fractured fragments. The patient recalled that tooth 11 had struck the floor 1 year ago without seeking any other treatment. In case 2, a 10-year-old girl fell down 1 d ago and wanted to have her teeth examined. Clinical examination showed a fracture line on the crown of tooth 21. CBCT images of tooth 21 also showed signs of hard tissue deposition between the fractured fragments. She also had a history of dental trauma 1 year ago and her tooth 11 received dental treatment by another dentist. According to her periapical radiograph at that time, tooth 21 was fractured 1 year ago and the fracture was overlooked by her dentist. Both of these two cases showed spontaneous healing of complicated crown-root fractures. After over 4 years of follow-up, both fractured teeth showed no signs of abnormality. CONCLUSION: These findings may provide new insights and perspectives on the management and treatment of crown-root fractures in children.

Myostain is involved in ginsenoside Rb1-mediated anti-obesity.

CONTEXT: Obesity, one of the major public health problems worldwide, has attracted increasing attention. Ginsenoside Rb1 is the most abundant active component of Panax ginseng C.A.Mey (Araliaceae) and is reported to have beneficial effects on obesity and diabetes. However, the mechanisms by which Rb1 regulates obesity remain to be explored. OBJECTIVE: This paper intends to further explore the mechanism of Rb1 in regulating obesity. MATERIALS AND METHODS: The C57BL/6 obese mice were divided into two groups: the control (CTR) and Rb1. The CTR group [intraperitoneally (ip) administered with saline] and the Rb1 group (ip administered with Rb1, 40 mg/kg/d) were treated daily for four weeks. In vitro, Rb1 (0, 10, 20, 40 µM) was added to differentiated C2C12 cells and Rb1 (0, 20, 40 µM) was added to 3T3-L1 cells. After 24 h, total RNA and protein from C2C12 cells and 3T3-L1 cells were used to detect myostatin (MSTN) and fibronectin type III domain-containing 5 (FNDC5) expression. RESULTS: Rb1 reduced the body weight and adipocyte size. Improved glucose tolerance and increased basic metabolic activity were also found in Rb1 treated mice. MSTN was downregulated in differentiated C2C12 cells, 3T3-L1 cells and adipose tissues upon Rb1 treatment. FNDC5 was increased after Rb1 treatment. However, MSTN overexpression attenuated Rb1-mediated decrease accumulation of lipid droplets in differentiated 3T3-L1 adipocytes. DISCUSSION & CONCLUSIONS: Rb1 may ameliorate obesity in part through the MSTN/FNDC5 signalling pathway. Our results showed that Rb1 can be used as an effective drug in the treatment of human obesity.

Effects of Danggui-Shaoyao-San on depression- and anxiety-like behaviors of rats induced by experimental tooth movement.

PURPOSE: To investigate the effects of Danggui-Shaoyao-San (DSS) on depression- and anxiety-like behavior induced by experimental tooth movement (ETM) in rats. MATERIALS AND METHODS: Thirty-six rats were randomly divided into a sham group (n = 12; rats underwent all operation procedures, except placement of orthodontic forces, and received saline treatment), ETM group (n = 12; rats received saline treatment and ETM), and DETM group (n = 12; rats received DSS [dose: 150 mg/kg twice daily from preoperative day 5 to postoperative day 7] treatment and ETM). The vacuous chewing movement (VCM) test, open-field test, and elevated plus maze test were performed to assess the depression- and anxiety-like behaviors of the rats. RESULTS: DSS pretreatment significantly decreased the ETM-induced VCM time (P < 0.05, DETM vs. ETM), increased the ETM-induced time to the central area of experimental device during the 5 min open-field test (P < 0.05, DETM vs. ETM), and increased the ratio of time spent in the open arms of the 5 min elevated plus maze test induced by ETM (P < 0.01, DETM vs. ETM). CONCLUSIONS: DSS pretreatment can restore the impaired abilities of rats caused by ETM-induced depression- and anxiety-like behavior.

Analysis of Psychological Trends and Policy Recommendations of Medical Staff in Northern China in the Latter Stages of the COVID-19 Pandemic.

Aim: Since the 2019 coronavirus disease (COVID-19) outbreak, medical staff have faced greater psychological stress and are prone to psychological problems such as anxiety and depression, as confirmed by several studies. This study further clarifies the psychological status of Chinese medical staff during the stable phase of the pandemic through a cross-sectional investigation in a large population sample in northern China. Methods: Subjects: Clinical frontline medical staff from seven hospitals in Liaoning Province were recruited from November 2020 to February 2021. Research Tools: The research tools used were the Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), Simplified Coping Style Questionnaire (SCSQ), and General Status Questionnaire. Statistical Analysis: SPSS 22.0, ANOVA variance analysis, and multiple logistics regression were used for statistical analysis. P-values of <0.05 indicated significant statistical differences. Results: A total of 3,144 medical staff completed the survey (599 men [19.1%] and 2,545 women [80.9%]; 1,020 doctors [32.4%] and 2,124 nurses [67.6%]). Among all subjects, the rates of anxiety and depression were 21.1% (663/3, 144) and 43.9% (1,381/3,144), respectively. Multiple logistic comparative analysis revealed that age (OR = 1.272, 95% CI = 1.036-1.561, P = 0.022), the need for psychological counseling (OR = 1.566, 95% CI = 1.339-1.830, P < 0.001), and the coexistence of depression (OR = 0.050, 95% CI = 0.038-0.066, P < 0.001) were significantly associated with anxiety. Coexisting anxiety was also associated with the occurrence of depression (OR = 0.050, 95% CI = 0.038-0.065, P < 0.001). Conclusions: In the later stages of the pandemic in China, the occurrence rates of anxiety and depression among medical staff remain high. In addition to age, there is little correlation between anxiety or depression and general factors such as gender and profession. As a special group, medical staff show different psychological changes at various times during a stressful event. Concerning for the psychological needs of medical staff and different psychologically oriented policy implementation are needed.

The miR-378c-Samd1 circuit promotes phenotypic modulation of vascular smooth muscle cells and foam cells formation in atherosclerosis lesions.

MicroRNAs have emerged as key regulators in vascular diseases and are involved in the formation of atherosclerotic lesions. However, the atherosclerotic-specific MicroRNAs and their functional roles in atherosclerosis are unclear. Here, we report that miR-378c protects against atherosclerosis by directly targeting Sterile Alpha Motif Domain Containing 1 (Samd1), a predicted transcriptional repressor. miR-378c was strikingly reduced in atherosclerotic plaques and blood of acute coronary syndrome (ACS) patients relative to healthy controls. Suppression of miR-378c promoted vascular smooth muscle cells (VSMCs) phenotypic transition during atherosclerosis. We also reported for the first time that Samd1 prolonged immobilization of LDL on the VSMCs, thus facilitated LDL oxidation and subsequently foam cell formation. Further, we found that Samd1 contains predicted DNA binding domain and directly binds to DNA regions as a transcriptional repressor. Together, we uncovered a novel mechanism whereby miR-378c-Samd1 circuit participates in two key elements of atherosclerosis, VSMCs phenotypic transition and LDL oxidation. Our results provided a better understanding of atherosclerosis pathophysiology and potential therapeutic management by targeting miR-378c-Samd1 circuit.

CdS Induced Passivation toward High Efficiency and Stable Planar Perovskite Solar Cells.

In perovskite solar cells, the halide vacancy defects on the perovskite film surface/interface will instigate charge recombination, leading to a decrease in cell performance. In this study, cadmium sulfide (CdS) has been introduced into the precursor solution to reduce the halide vacancy defects and improve the cell performance. The highest efficiency of the device reaches 21.62%. Density functional theory calculation reveals that the incorporated Cd2+ ions can partially replace Pb2+ ions, thus forming a strong Cd-I bond and effectively reducing iodide vacancy defects (VI); at the same time, the loss of the charge recombination is significantly reduced because VI is filled by S2- ions. Besides, the substitution of Cd2+ for Pb2+ could increase the generation of PbI2, which can further passivate the grain boundary. Therefore, the stability of the cells, together with the efficiency of the power conversion efficiencies (PCEs), is also improved, maintaining 87.5% of its initial PCEs after being irradiated over 410 h. This work provides a very effective strategy to passivate the surface/interface defects of perovskite films for more efficient and stable optoelectronic devices.

A p-p+ Homojunction-Enhanced Hole Transfer in Inverted Planar Perovskite Solar Cells.

Perovskite solar cells (PSCs) have triggered a research trend in solar energy devices in view of their high power conversion efficiency and ease of fabrication. However, more delicate strategies are still required to suppress carrier recombination at charge transfer interfaces, which is the necessary path to high-efficiency solar cells. Here, a p-p+ homojunction was constructed on basis of NiO film to enhance hole transfer in an inverted planar perovskite solar cell. The homojunction was generated by fabricating a NiO/Cu:NiO bilayer film. The density functional theory calculation demonstrated the charge density difference in the two layers, which could generate a space charge region and a band bending at the junction, and the result was further proved by energy level structure analysis of NiO and Cu:NiO films. The designed homojunction could accelerate the hole transfer and inhibit carrier recombination at the interface between hole transfer layer and perovskite layer. Finally, the inverted planar perovskite solar cell with p-p+ homojunction showed an efficiency of 18.30 % and a high fill factor of 0.81, which were much higher than the counterpart of the PSCs individually using NiO or Cu:NiO as hole transfer layer. This work developed a new structure of hole transport layer to enhance the performance of PSCs, and also provided new ideas for design of charge transfer films.

Intermolecular π-π Conjugation Self-Assembly to Stabilize Surface Passivation of Highly Efficient Perovskite Solar Cells.

Surface passivation is an effective approach to eliminate defects and thus to achieve efficient perovskite solar cells, while the stability of the passivation effect is a new concern for device stability engineering. Herein, tribenzylphosphine oxide (TBPO) is introduced to stably passivate the perovskite surface. A high efficiency exceeding 22%, with steady-state efficiency of 21.6%, is achieved, which is among the highest performances for TiO2 planar cells, and the hysteresis is significantly suppressed. Further density functional theory (DFT) calculation reveals that the surface molecule superstructure induced by TBPO intermolecular π-π conjugation, such as the periodic interconnected structure, results in a high stability of TBPO-perovskite coordination and passivation. The passivated cell exhibits significantly improved stability, with sustaining 92% of initial efficiency after 250 h maximum-power-point tracking. Therefore, the construction of a stabilized surface passivation in this work represents great progress in the stability engineering of perovskite solar cells.

Enhanced Perovskite Solar Cell Efficiency Via the Electric-Field-Induced Approach.

The stability issue hinders the commercialization of the perovskite solar cells (PSCs), which is widely recognized. The efficiency generally decreases over time during the working condition. Here, we report an efficiency enhancement phenomenon of PSCs in the stability test at the maximum power point, which is speculated to be related to the electric-field-induced ion migration. The defect density and efficiency-related parameters were traced in situ by admittance spectroscopy and transient photovoltage when the cell works under bias voltage. The performance enhancement was revealed to be attributed to the reduction of the cell defects owing to ion migration. An efficiency of 22.3% can be achieved after the bias voltage was kept for 8 h. These findings suggest that ion migration is a double-edged sword that affects the electrical stability of PSCs, which presents a potential approach to improve the device's stability by appropriately controlling the defect states.

Integrative module analysis of HCC gene expression landscapes.

Despite hepatocellular carcinoma (HCC) being a common cancer globally, its initiation and progression are not well understood. The present study was designed to investigate the hub genes and biological processes of HCC, which change substantially during its progression. Three gene expression profiles of 480 patients with HCC were obtained from the Gene Expression Omnibus database. Subsequent to performing functional annotations and constructing protein-protein interaction (PPI) networks, 657 differentially expressed genes were identified, which were subsequently used to screen candidate hub genes. PPI networks were modularized using the weighted gene correlation network analysis algorithm, the topological overlapping matrix and the hierarchical cluster tree, which were utilized via STRING. Clinical data obtained from The Cancer Genome Atlas were then analyzed to validate the experiments performed using six hub genes. Additionally, a transcription factor and microRNA-mRNA network were constructed to determine the potential regulatory mechanisms of six hub genes. The results revealed that the oxidation-reduction process and cell cycle associated processes were markedly involved in HCC progression. Six highly expressed genes, including cyclin B2, cell division cycle 20, mitotic arrest deficient 2 like 1, minichromosome maintenance complex component 2, centromere protein F and BUB mitotic checkpoint serine/threonine kinase B, were confirmed as hub genes and validated via experiments associated with cell division. These hub genes are necessary for confirmatory experiments and may be used in clinical gene therapy as biomarkers or drug targets.

Effects of atorvastatin on time-dependent change of fast sodium current in simulated acute ischaemic ventricular myocytes.

INTRODUCTION: Our previous experiments showed that the transient sodium current (INa) was abnormally increased in early ischaemia and atorvastatin could inhibit INa. The aim of this study was to observe the time-dependent effects of simulated ischaemia on INa and characterise the direct effects of atorvastatin on ischaemic INa. METHODS: Left ventricular myocytes were isolated from Wistar rats and randomly divided into two groups: a control group (normal to simulated ischaemia) and a statin group (normal to simulated ischaemia with 5 µmol/l atorvastatin). The INa was recorded under normal conditions (as baseline) by whole-cell patch clamp and recorded from three to 21 minutes in the next phase of simulated ischaemic conditions. RESULTS: In the control group, normalised INa (at -40 mV) was increased to the peak (1.15 ± 0.08 mA) at three minutes of ischaemia compared with baseline (0.95 ± 0.04 mA, p < 0.01), it subsequently returned to baseline levels at nine and 11 minutes of ischaemia (0.98 ± 0.12 and 0.92 ± 0.12 mA, respectively), and persistently decreased with prolonged ischaemic time. In the statin group, there were no differences between baseline and the early stages of ischaemia (0.97 ± 0.04 mA at baseline vs 0.92 ± 0.12 mA in ischaemia for three minutes, p > 0.05). CONCLUSION: Our results suggest that, in the early stages of ischaemia, changes in INa in ventricular myocytes are time-dependent, showing an initial increase followed by a decrease, while atorvastatin inhibited the transient increase in INa and made the change more gradual.

Bladder drug mirabegron exacerbates atherosclerosis through activation of brown fat-mediated lipolysis.

Mirabegron (Myrbetriq) is a ß3-adrenoreceptor agonist approved for treating overactive bladder syndrome in human patients. This drug can activate brown adipose tissue (BAT) in adult humans and rodents through the ß3-adrenoreceptor-mediated sympathetic activation. However, the effect of the mirabegron, approved by the US Food and Drug Administration, on atherosclerosis-related cardiovascular disease is unknown. Here, we show that the clinical dose of mirabegron-induced BAT activation and browning of white adipose tissue (WAT) exacerbate atherosclerotic plaque development. In apolipoprotein E-/- (ApoE-/-) and low-density lipoprotein (LDL) receptor-/- (Ldlr-/-) mice, oral administration of clinically relevant doses of mirabegron markedly accelerates atherosclerotic plaque growth and instability by a mechanism of increasing plasma levels of both LDL-cholesterol and very LDL-cholesterol remnants. Stimulation of atherosclerotic plaque development by mirabegron is dependent on thermogenesis-triggered lipolysis. Genetic deletion of the critical thermogenesis-dependent protein, uncoupling protein 1, completely abrogates the mirabegron-induced atherosclerosis. Together, our findings suggest that mirabegron may trigger cardiovascular and cerebrovascular diseases in patients who suffer from atherosclerosis.

Circulating microRNA-378 levels serve as a novel biomarker for assessing the severity of coronary stenosis in patients with coronary artery disease.

Background: Circulating microRNAs (miRNA) are steady preserved in blood plasma. Multiple evidences have shown that miRNAs play a crucial role in cardiovascular disease including miRNA-378, which has been illustrated to participate in diverse physiological and pathological processes of cardiovascular disease. In the present study, we aim to explore the expression of plasma miRNA-378 and its clinical significance in patients with coronary artery disease (CAD).Methods: MiRNA-378 expression in blood plasma was performed by quantitative real-time PCR (qRT-PCR) in 215 CAD patients and 52 matched controls of healthy populations. Medical information of all patients including the results of coronary angiography (CAG) was acquired through hospital information system (HIS). Spearman's correlation, binary linear regression, and covariance analysis were used to examine the association between miRNA-378 and relative clinical risk factors. Receiver operating characteristic curve analysis was applied to evaluate the value of miRNA-378 in predicting the disease severity of coronary lesion.Results: Plasma miR-378 expression was significantly down-regulated in CAD patients compared with healthy controls. Relative miR-378 level was shown conversely correlated with Gensini score, which present the severity of coronary artery lesions. Moreover, it is indicated that miR-378 expression can effectively distinguish patients with or without coronary artery stenosis.Conclusions: Plasma miR-378 levels appear to be a promising non-invasive biomarker, but require to be further validated by a large cohort study in future.

Response to olaparib in metastatic castration-resistant prostate cancer with germline BRCA2 mutation: a case report.

BACKGROUND: Prostate cancer is a heterogeneous disease, meaning patients would benefit from different treatment strategies based on their molecular stratification. In recent years, several genomic studies have identified prostate cancers with defects in DNA repair genes. It is known that the PARP inhibitor, olaparib, has a significant synthetic lethal effect on tumors with BRCA 1/2 mutations, particularly in ovarian and breast cancer. CASE PRESENTATION: In this study, we describe a patient with metastatic castration-resistant prostate cancer (mCRPC) containing a BRCA2 germline mutation who underwent olaparib treatment. The efficacy of the treatment was monitored by serum TPSA level as well as mutation levels of circulating tumor DNA (ctDNA) using next-generation sequencing (NGS). The patient responded to the olaparib treatment as indicated by the minimal residual levels of TPSA and tumor-specific mutations of ctDNA in plasma after four months of treatment, although the patient eventually progressed at six-month post-treatment with significantly elevated and newly acquired somatic mutations in ctDNA. CONCLUSIONS: Our study provides evidence that mCRPC with BRCA2 germline mutations could response to PARP inhibitor, which improves patient's outcome. We further demonstrated that NGS-based genetic testing on liquid biopsy can be used to dynamically monitor the efficacy of treatment.

Room-temperature high spin-orbit torque due to quantum confinement in sputtered BixSe(1-x) films.

The spin-orbit torque (SOT) that arises from materials with large spin-orbit coupling promises a path for ultralow power and fast magnetic-based storage and computational devices. We investigated the SOT from magnetron-sputtered BixSe(1-x) thin films in BixSe(1-x)/Co20Fe60B20 heterostructures by using d.c. planar Hall and spin-torque ferromagnetic resonance (ST-FMR) methods. Remarkably, the spin torque efficiency (θS) was determined to be as large as 18.62 ± 0.13 and 8.67 ± 1.08 using the d.c. planar Hall and ST-FMR methods, respectively. Moreover, switching of the perpendicular CoFeB multilayers using the SOT from the BixSe(1-x) was observed at room temperature with a low critical magnetization switching current density of 4.3 × 105 A cm-2. Quantum transport simulations using a realistic sp3 tight-binding model suggests that the high SOT in sputtered BixSe(1-x) is due to the quantum confinement effect with a charge-to-spin conversion efficiency that enhances with reduced size and dimensionality. The demonstrated θS, ease of growth of the films on a silicon substrate and successful growth and switching of perpendicular CoFeB multilayers on BixSe(1-x) films provide an avenue for the use of BixSe(1-x) as a spin density generator in SOT-based memory and logic devices.