TMPRSS2 and glycan receptors synergistically facilitate coronavirus entry.

The entry of coronaviruses is initiated by spike recognition of host cellular receptors, involving proteinaceous and/or glycan receptors. Recently, TMPRSS2 was identified as the proteinaceous receptor for HCoV-HKU1 alongside sialoglycan as a glycan receptor. However, the underlying mechanisms for viral entry remain unknown. Here, we investigated the HCoV-HKU1C spike in the inactive, glycan-activated, and functionally anchored states, revealing that sialoglycan binding induces a conformational change of the NTD and promotes the neighboring RBD of the spike to open for TMPRSS2 recognition, exhibiting a synergistic mechanism for the entry of HCoV-HKU1. The RBD of HCoV-HKU1 features an insertion subdomain that recognizes TMPRSS2 through three previously undiscovered interfaces. Furthermore, structural investigation of HCoV-HKU1A in combination with mutagenesis and binding assays confirms a conserved receptor recognition pattern adopted by HCoV-HKU1. These studies advance our understanding of the complex viral-host interactions during entry, laying the groundwork for developing new therapeutics against coronavirus-associated diseases.

V-Based MXene/MAX Heterostructure Composites with Enhancing Dielectric Loss for Broadband Microwave Absorption.

Electromagnetic wave absorption performance is strictly dependent on attenuation and impedance matching, which are directly influenced by the ratio of MXene/MAX in the multilayer structured MXene/MAX composites. However, there is still a challenge to achieve collaborative optimization of dielectric loss and impedance matching by precisely regulating the proportional relationship of MXene/MAX. Herein, V-based MXene/MAX heterostructure composites with different V2C/V2AlC ratios were successfully synthesized by rationally controlling the temperature and time of the hydrothermal reaction. Experimental results indicated that V2C-100 °C-1 harvested the balance between reduced impedance matching and enhanced dielectric losses, which was attributed to the mildly enhanced conduction loss and polarization loss. The first principles indicated that abundant electrons migrate from the V atoms of the MXene to the C atoms of the MAX phase. The charge redistributed and accumulated at the interface, exciting the increase in the dielectric loss of V2C-100 °C-1. As a result, the V2C-100 °C-1 heterostructure composite had an excellent electromagnetic absorption effect with a minimum reflection loss of -50.06 dB and a wide effective absorption bandwidth of 4.0 GHz (12.72-16.72 GHz). This work provides a valuable experience for the development of efficient MXene-based microwave absorbing materials.

Positive buttress reduction in femoral neck fractures: a literature review.

BACKGROUND: Femoral neck fractures (FNFs) in young adults are usually caused by high-energy trauma, and their treatment remains a challenging issue for orthopedic surgeons. The quality of reduction is considered an important factor in improving the poor prognosis of patients with FNFs. In recent years, positive buttress closed reduction technique has received widespread attention in the treatment of FNFs. This comprehensive literature review is designed to encapsulate the impacts of both non-anatomic and anatomic reduction on the biomechanical stability, clinical outcomes, and postoperative complications in the management of FNFs, conjecture the efficacy of positively braced reduction techniques and provide a thorough summarization of the clinical outcomes. METHODS: In this literature review, we have examined all clinical and biomechanical studies related to the treatment of FNFs using non-anatomical reduction or positive and negative buttress reduction. PubMed, Web of Science, Google Scholar and Embase Library databases were searched systematically for studies published before September 1, 2023. Published literature on fracture reduction techniques for treating FNFs was reviewed. In addition, we evaluated the included literature using the MINORs tool. RESULTS: Although the "arch bridge" structure formed by the positive buttress reduction technique improved the support to the cortical bone and provided a more stable biomechanical structure, no significant differences were noted in the clinical efficacy and incidence of postoperative complications between the positive buttress reduction and anatomical reduction. CONCLUSION: Positive buttress reduction is an effective treatment method for young patients with FNFs. When facing difficult-to-reduce FNF, positive buttress reduction should be considered first, followed by anatomical reduction. However, negative buttress reduction should be avoided.

Distribution of multi-level B cell subsets in thymoma and thymoma-associated myasthenia gravis.

B-cell subsets in peripheral blood (PB) and tumor microenvironment (TME) were evaluated to determine myasthenia gravis (MG) severity in patients with thymoma-associated MG (TMG) and the distribution of B cells in type B TMG. The distribution of mature B cells, including Bm1-Bm5, CD19+ and CD20+ B cells and non-switched (NSMBCs) and switched (SMBCs) memory B cells, were determined in 79 patients with thymoma or TMG. Quantitative relationships between the T and TMG groups and the TMG-low and TMG-high subgroups were determined. NSMBCs and SMBCs were compared in TME and PB. Type B thymoma was more likely to develop into MG, with types B2 and B3 being especially associated with MG worsening. The percentage of CD19+ B cells in PB gradually increased, whereas the percentage of CD20+ B cells and the CD19/CD20 ratio were not altered. The (Bm2 + Bm2')/(eBm5 + Bm5) index was significantly higher in the TMG-high than in thymoma group. The difference between SMBC/CD19+ and NSMBC/CD19+ B cell ratios was significantly lower in the thymoma than TMG group. NSMBCs assembled around tertiary lymphoid tissue in thymomas of patients with TMG. Few NSMBCs were observed in patients with thymoma alone, with these cells being diffusely distributed. MG severity in patients with TMG can be determined by measuring CD19+ B cells and Bm1-Bm5 in PB. The CD19/CD20 ratio is a marker of disease severity in TMG patients. Differences between NSMBCs and SMBCs in PB and TME of thymomas can synergistically determine MG severity in patients with TMG.

Dexamethasone improves thymoma-associated myasthenia gravis via the AKT-mTOR pathway.

Clinically, thymoma patients are often complicated with myasthenia gravis (MG). Dexamethasone, a glucocorticoid with anti-inflammatory effects, could be used as an immunosuppressant for thymoma-associated MG, but the mechanism of action remains to be explored. In this study, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, weighted gene co-expression network analysis (WGCNA) of potential targets was performed by screening the intersection targets of dexamethasone and thymoma-associated MG from the database. Furthermore, the key targets and core active components were identified by topological analysis of the protein-protein interaction (PPI) network. Molecular docking technology was applied to screen the complexes with stable binding of dexamethasone and core targets. Patients with thymoma were divided into two groups according to whether they received dexamethasone before operation, and immunohistochemistry and western blot were used to verify the selected target of dexamethasone in treating thymoma-associated MG. The results showed that the action pathway of dexamethasone on the disease was closely enriched to phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB/AKT), mammalian target of rapamycin (mTOR) signaling pathways. The expressions of AKT1 and its downstream molecule mTOR in the thymoma microenvironment of thymoma-associated MG patients who did not receive dexamethasone before operation were higher than those in the group receiving dexamethasone before operation. This study demonstrates that dexamethasone can promote apoptosis through the AKT-mTOR pathway for the treatment of thymoma-associated MG, as validated by network pharmacology predictions and clinical specimen experiments, and can be verified by large-scale clinical trials in the future. This study also provides theoretical support and new research perspectives for this disease.

Downregulation of HMGB1 in thymoma cells affects T cell differentiation.

Introduction: Thymoma is the most common anterior mediastinal tumor and is closely associated with myasthenia gravis (MG). Our previous study showed that the expression of Th17 cells increased and the expression of Treg decreased in MG-associated thymoma tissues and peripheral blood. High mobility group box 1 (HMGB1) is an inflammatory mediator and participates in the pathogenesis of various autoimmune diseases. However, its function in thymoma is still unclear. Material and methods: We first analyzed immune indices in peripheral blood of patients with MG-associated thymoma and patients with thymoma alone. Next, we explored the expression of HMGB1 in MG-associated thymoma and thymoma alone tissues. Furthermore, we transfected si-HMGB1 in thymoma cell line Thy0517 and co-cultured Thy0517 with peripheral blood mononuclear cells (PBMC). Results: In this study, the levels of IgG, C3, C4, CRP and globulins in peripheral blood of patients with MG-associated thymoma were different from those of patients with thymoma alone (p < 0.05). The expression of HMGB1 in MG-associated thymoma tissues was higher than thymoma alone. Co-culture of Thy0517 and PBMC showed that the percentage of Th17 cells in PBMC was lower than that in the control group, and the percentage of Treg cells was higher than that in the control group. Conclusions: These findings demonstrate that HMGB1 is involved in the mechanism of abnormal Th17/Treg cell differentiation in thymoma and affects the occurrence of immune abnormalities in MG-associated thymoma.

The Diagnostic and Prognostic Value of the Immune Checkpoint BGN in Thymoma.

Thymoma is frequently correlated with various autoimmune diseases. However, unequivocal therapeutic targets for thymoma remain undefined, and the role of immune checkpoints in the development of thymoma-related autoimmune illnesses is unclear. We examined 39 thymoma samples and 44 normal control samples from the GEO database. Following batch correction, we identified 224 Differentially Expressed Genes (DEGs) using the Limma package. We employed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to enrich for functional pathways of DEGs. We utilized a Protein-Protein Interaction (PPI) network to identify hub genes and determine their correlation with immune cell infiltration using CIBERSORT. Real-time quantitative polymerase chain reaction (RT-qPCR), western blot, and immunohistochemical staining were implemented to verify identified hub genes in vivo. Simultaneously, we evaluated the prognostic relevance of the hub gene using clinical data. We determined COL1A1, COL1A2, and BGN to be the central hub genes in thymoma. Validation via RT-qPCR, Western blot, and immunohistochemical staining established significant statistical divergence between thymoma tissue and the normal thymus for only BGN. Expression levels of BGN showed strong negative correlation with the infiltration level of B cells and CD4+ T cells, yet a significant positive correlation with the level of neutrophil infiltration. We found high immune infiltration levels of macrophages, NK cells, and Th1 cells in the thymoma microenvironment in patients with a high expression of BGN. Co-localization of BGN and macrophages within thymoma tissue was discerned via tissue staining. Clinical data dictated that thymoma patients exhibiting elevated BGN expression underwent longer hospital stays, longer lengths in intensive care units, greater hospitalization costs, and extended ventilator usage; our study, augmented by clinical information, recognized BGN as possessive of diagnostic and prognostic significance in thymoma through in silico and molecular verification experiments. Our findings offered an important objective for thymoma-treated autoimmune disease comprehension, supplemented by the strong association with immune infiltration.

A New Design to Rayleigh Wave EMAT Based on Spatial Pulse Compression.

The main disadvantage of the electromagnetic acoustic transducer (EMAT) is low energy-conversion efficiency and low signal-to-noise ratio (SNR). This problem can be improved by pulse compression technology in the time domain. In this paper, a new coil structure with unequal spacing was proposed for a Rayleigh wave EMAT (RW-EMAT) to replace the conventional meander line coil with equal spacing, which allows the signal to be compressed in the spatial domain. Linear and nonlinear wavelength modulations were analyzed to design the unequal spacing coil. Based on this, the performance of the new coil structure was analyzed by the autocorrelation function. Finite element simulation and experiments proved the feasibility of the spatial pulse compression coil. The experimental results show that the received signal amplitude is increased by 2.3~2.6 times, the signal with a width of 20 µs could be compressed into a δ-like pulse of less than 0.25 µs and the SNR is increased by 7.1-10.1 dB. These indicate that the proposed new RW-EMAT can effectively enhance the strength, time resolution and SNR of the received signal.

Laser welding simulation of large-scale assembly module of stainless steel side-wall.

Due to the advantageous characteristics of laser welding technology, it is being increasingly used for constructing stainless steel rail vehicles. It can improve the appearance of a vehicle, enable designs with a relatively high degree of flatness, and ensure higher-quality connections between different parts of a vehicle. Moreover, it can improve the strength and stiffness of the components of the vehicle. In this study, a large-scale assembly module of a stainless steel side-wall was considered as the research object. The combined heat source model of a Gaussian heat source and a cylindrical volume heat source was used to obtain the heat source parameters of laser welding to match the experimental data. Based on the thermal cycle curve method (TCCM), the influence of the number of weld segments and mesh divisions of the local model on the efficiency and accuracy of laser welding simulations was investigated. Thereafter, the research results were applied to the welding simulation of the whole side-wall module. The shape of the molten pool obtained using the combined heat source was closer to that of the experiments (error < 10%), demonstrating the accuracy and effectiveness of the developed the heat source model for laser welding simulation. For local model laser welding using the TCCM, a coarse mesh was used, and the weld was divided into four segments, and highly accurate results were obtained. This calculation time was only 5.97% of that of a moving heat source in case of the thermo-elastic-plastic method (TEPM). Residual stress and welding deformation of the stainless steel side-wall module were calculated according to actual process parameters and the results of local model simulation. Residual stress was discontinuously distributed at the weld segments, and it only slightly influenced the overall stress distribution. The maximum residual stress (462.15 MPa) occurred at the weld of the large crossbeam. Welding eight small and two large crossbeams influenced the deformation change and the maximum deformation (1.26 mm) appeared in the middle position of the left side-wall. The findings of this study show that the TCCM has high calculation accuracy and is sufficiently economical for predicting laser welding of large structures.

ECGNet: An Efficient Network for Detecting Premature Ventricular Complexes Based on ECG Images.

BACKGROUND: Preoperative prediction of the origin site of premature ventricular complexes (PVCs) is critical for the success of operations. However, current methods are not efficient or accurate enough. In addition, among the proposed strategies, there are few good prediction methods for electrocardiogram (ECG) images combined with deep learning aspects. METHODS: We propose ECGNet, a new neural network for the classification of 12-lead ECG images. In ECGNet, 609 ECG images from 310 patients who had undergone successful surgery in the Division of Cardiology, the First Affiliated Hospital of Soochow University, are utilized to construct the dataset. We adopt dense blocks, special convolution kernels and divergent paths to improve the performance of ECGNet. In addition, a new loss function is designed to address the sample imbalance situation, whose cause is the uneven distribution of cases themselves, which often occurs in the medical field. We also conduct extensive experiments in terms of network prediction accuracy to compare ECGNet with other networks, such as ResNet and DarkNet. RESULTS: Our ECGNet achieves extremely high prediction accuracy (91.74%) and efficiency with very small datasets. Our newly proposed loss function can solve the problem of sample imbalance during the training process. CONCLUSION: The proposed ECGNet can quickly and accurately realize the multiclassification of PVCs after training with little data. Our network has the potential to be helpful to doctors with a preoperative diagnosis of PVCs. We will continue to collect similar cases and perfect our network structure to further improve the accuracy of our network's prediction.

[Role of Histone Modifications in Acute Kidney Injury Progressing to Chronic Kidney Disease]. / ç»„è›‹ç™½ä¿®é¥°åœ¨æ€¥æ€§è‚¾æŸä¼¤å‘æ ¢æ€§è‚¾è„ç— è½¬åŒ–ä¸­çš„ä½œç”¨.

Acute kidney injury (AKI), a clinical syndrome caused by various factors, is characterized by a rapid decline in kidney function in a short period of time. AKI affects the short-term prognosis of patients and may also induce chronic kidney disease (CKD). However, the current treatment options for AKI mainly focus on symptom management. Specific therapeutic measures available for the prevention of transition from AKI to CKD are very limited in number. Histones are basic proteins that intricately bind the DNA in chromosomes. After translation, histones undergo various modifications on their amino-terminal tails, such as methylation, acetylation, phosphorylation, ubiquitination, and lactylation, collectively forming the "histone code", which affects the expression of genes mainly by regulating the elastic structure of chromatin or recruiting specific proteins. Extensive research conducted in recent years on histone post-translational modifications (PTMs) has also sparked continuous interest in their association with the AKI-to-CKD transition. Therefore, this paper highlights the significant role of PTMs in the process of AKI developing and progressing to CKD, with a view to finding new approaches to preventing the progression of AKI to CKD.

Adaptive Response and Transcriptomic Analysis of Flax (Linum usitatissimum L.) Seedlings to Salt Stress.

Soil salinity constrains agricultural development in arid regions. Flax is an economically important crop in many countries, and screening or breeding salinity-resistant flax cultivars is necessary. Based on the previous screening of flaxseed cultivars C71 (salt-sensitive) and C116 (salt-tolerant) as test materials, flax seedlings stressed with different concentrations of NaCl (0, 100, 150, 200, and 250 mmol/L) for 21 days were used to investigate the effects of salt stress on the growth characteristics, osmotic regulators, and antioxidant capacity of these flax seedlings and to reveal the adaptive responses of flax seedlings to salt stress. The results showed that plant height and root length of flax were inhibited, with C116 showing lower growth than C71. The concentrations of osmotic adjustment substances such as soluble sugars, soluble proteins, and proline were higher in the resistant material, C116, than in the sensitive material, C71, under different concentrations of salt stress. Consistently, C116 showed a better rapid scavenging ability for reactive oxygen species (ROS) and maintained higher activities of antioxidant enzymes to balance salt injury stress by inhibiting growth under salt stress. A transcriptome analysis of flax revealed that genes related to defense and senescence were significantly upregulated, and genes related to the growth and development processes were significantly downregulated under salt stress. Our results indicated that one of the important adaptations to tolerance to high salt stress is complex physiological remediation by rapidly promoting transcriptional regulation in flax.

Thymectomy in ocular myasthenia gravis-prognosis and risk factors analysis.

BACKGROUND: Several retrospective studies have identified risk factors associated with ocular myasthenia gravis (OMG) generalization in non-surgical patients. However, the outcomes of OMG after thymectomy have not been investigated fully. This study aimed to explore the clinical predictors of post-thymectomy OMG prognosis. METHODS: We performed a retrospective review of OMG patients who underwent thymectomy at our institution from January 2012 to December 2021. Kaplan-Meier and Cox proportional hazard regression analyses were used to evaluate associations between clinical features and prognosis. The main outcome measures were OMG conversion, complete stable remission (CSR), and clinical improvement. RESULTS: Fifty-eight patients were identified for conversion analysis. Thirteen (22.4%) developed generalized myasthenia gravis (GMG) at a median time of 12.7 (3-37.3) months from symptom onset. Repetitive nerve stimulation (RNS)-positivity was associated with increased risk of conversion to GMG (P = 0.002). Patients with histotype B2/B3 thymoma showed a higher risk of conversion (P = 0.002) than did patients with hyperplasia and AB/B1 thymoma. Fifty-two patients fulfilled the criteria for CSR and improvement. Sixteen (30.8%) achieved CSR at a median time of 28.7 (15-54) months after thymectomy. Fifteen (28.8%) showed clinical improvement at last follow up. Patients who achieved CSR showed a younger age of onset (P = 0.022), lower percentage of acetylcholine receptor antibody-seropositivity (P = 0.029). Histologically, patients with thymic hyperplasia and stage I thymoma showed a higher chance of CSR (P = 0.010) than did patients with stage II/III thymoma. Multivariate analysis revealed that RNS-positivity (hazard ratio [HR] 6.007, P = 0.021) and histotype B2/B3 thymoma (HR 4.611, P = 0.048) were associated with OMG conversion. Thymic hyperplasia and stage I thymoma (HR 0.300, P = 0.026) were associated with OMG CSR after thymectomy. CONCLUSION: For OMG patients after thymectomy, RNS-positivity and histotype B2/B3 thymoma are independent predictors of conversion to GMG. On the other hand, thymic hyperplasia and stage I thymoma independently predict CSR.

Oxidative Stress-Related lncRNAs Are Potential Biomarkers for Predicting Prognosis and Immune Responses in Patients With LUAD.

Lung adenocarcinoma is increasingly harmful to society and individuals as cancer with an inferior prognosis and insensitive to chemotherapy. Previous studies have demonstrated that oxidative stress and lncRNAs play a vital role in many biological processes. Therefore, we explored the role of lncRNAs associated with oxidative stress in the prognosis and survival of LUAD patients. We examined the expression profiles of lncRNAs and oxidative stress genes in this study. A prognosis prediction model and a nomogram were built based on oxidative stress-related lncRNAs. Functional and drug sensitivity analyses were also performed depending on oxidative stress-related lncRNA signature. Moreover, we investigated the relationship between immune response and immunotherapy. The results showed that a risk scoring model based on 16 critical oxidative stress lncRNAs was able to distinguish the clinical status of LUAD and better predict the prognosis and survival. Additionally, the model demonstrated a close correlation with the tumor immune system, and these key lncRNAs also revealed the relationship between LUAD and chemotherapeutic drug sensitivity. Our work aims to provide new perspectives and new ideas for the treatment and management of LUAD.

Self-Growing Binary Activation Network: A Novel Deep Learning Model With Dynamic Architecture.

For a deep learning model, the network architecture is crucial as a model with inappropriate architecture often suffers from performance degradation or parameter redundancy. However, it is experiential and difficult to find the appropriate architecture for a certain application. To tackle this problem, we propose a novel deep learning model with dynamic architecture, named self-growing binary activation network (SGBAN), which can extend the design of a fully connected network (FCN) progressively, resulting in a more compact architecture with higher performance on a certain task. This constructing process is more efficient than neural architecture search methods that train mass of networks to search for the optimal one. Concretely, the training technique of SGBAN is based on the function-preserving transformations that can expand the architecture and combine the information in the new data without neglecting the knowledge learned in the previous steps. The experimental results on four different classification tasks, i.e., Iris, MNIST, CIFAR-10, and CIFAR-100, demonstrate the effectiveness of SGBAN. On the one hand, SGBAN achieves competitive accuracy when compared with the FCN composed of the same architecture, which indicates that the new training technique has the equivalent optimization ability as the traditional optimization methods. On the other hand, the architecture generated by SGBAN achieves 0.59% improvements of accuracy, with only 33.44% parameters when compared with the FCNs composed of manual design architectures, i.e., 500 + 150 hidden units, on MNIST. Furthermore, we demonstrate that replacing the fully connected layers of the well-trained VGG-19 with SGBAN can gain a slightly improved performance with less than 1% parameters on all these tasks. Finally, we show that the proposed method can conduct the incremental learning tasks and outperform the three outstanding incremental learning methods, i.e., learning without forgetting, elastic weight consolidation, and gradient episodic memory, on both the incremental learning tasks on Disjoint MNIST and Disjoint CIFAR-10.

Identification and Validation of a Prognostic Immune-Related Gene Signature in Esophageal Squamous Cell Carcinoma.

Esophageal carcinoma (EC) is a common malignant cancer worldwide. Esophageal squamous cell carcinoma (ESCC), the main type of EC, is difficult to treat because of the widespread morbidity, high fatality rates, and low quality of life caused by postoperative complications and no specific molecular target. In this study, we screened genes to establish a prognostic model for ESCC. The transcriptome expression profiles of 81 ESCC tissues and 340 normal esophageal mucosal epithelium tissues were obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) cohorts. The transcriptome expression datasets of 19 esophageal squamous carcinoma cell lines were downloaded from Cancer Cell Line Encyclopedia (CCLE). The R software Limma package was used to identify 6,231 differentially expressed genes and 647 differentially expressed immune-related genes between normal and ESCC tissues. Gene functional analysis was performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Weighted gene co-expression network analysis (WGCNA) was used to screen out 18 immune-related prognostic genes. We then established the prognostic and risk signature using these genes, and the patients were divided into low-risk and high-risk groups. Compared with high-risk group patients, the low-risk group patients had longer overall survival. M1 macrophages and resting dendritic cells were differentially distributed between the low-risk and high-risk groups and were related to patient survival. We also examined the functional immune cell and immune molecule levels in low-risk and high-risk group patients, with significant differences in the tumor microenvironment between the two groups. To further verify the accuracy of the prognostic risk model, we performed area under the ROC curve (AUC) analysis. The AUC value was 0.931 for the prognostic risk, which was better than the microsatellite instability (MSI) and Tumor Immune Dysfunction and Exclusion (TIDE) scores. In conclusion, we found 18 immune-related prognostic genes related to the occurrence of ESCC and established a prognostic model for predicting disease severity.

Generic water-based spray-assisted growth for scalable high-efficiency carbon-electrode all-inorganic perovskite solar cells.

A water-based spray-assisted growth strategy is proposed to prepare large-area all-inorganic perovskite films for perovskite solar cells (PSCs), which involves in spraying of cesium halide water solution onto spin-coating-deposited lead halide films, followed by thermal annealing. With CsPbBr3 as an example, we show that as-proposed growth strategy can enable the films with uniform surface, full coverage, pure phase, large grains, and high crystallinity, which primarily benefits from the controllable CsBr loading quantity, and the use of water as CsBr solvent makes the reaction between CsBr and PbBr2 immune to PbBr2 film microstructure. As a result, the small-area (0.09 cm2) and large-area (1.00 cm2) carbon-electrode CsPbBr3 PSCs yield the record-high efficiencies of 10.22% and 8.21%, respectively, coupled with excellent operational stability. We also illustrate that the water-based spray-assisted deposition strategy is suitable to prepare CsPbCl3, CsPbIBr2, and CsPbI2Br films with outstanding efficiencies of 1.27%, 10.44%, and 13.30%, respectively, for carbon-electrode PSCs.

Microstructure Evolution in He-Implanted Si at 600 °C Followed by 1000 °C Annealing.

Si single crystal was implanted with 230 keV He+ ions to a fluence of 5 × 1016/cm2 at 600 °C. The structural defects in Si implanted with He at 600 °C and then annealed at 1000 °C were investigated by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The microstructure of an as-implanted sample is provided for comparison. After annealing, rod-like defects were diminished, while tangled dislocations and large dislocation loops appeared. Dislocation lines trapped by cavities were directly observed. The cavities remained stable except for a transition of shape, from octahedron to tetrakaidecahedron. Stacking-fault tetrahedrons were found simultaneously. Cavity growth was independent of dislocations. The evolution of observed lattice defects is discussed.

Polymer-Derived Ceramic Nanoparticle/Edge-Functionalized Graphene Oxide Composites for Lithium-Ion Storage.

Polymer-derived ceramics demonstrate great potential as lithium-ion battery anode materials with good cycling stability and large capacity. SiCNO ceramic nanoparticles are produced by the pyrolysis of polysilazane nanoparticles that are synthesized via an oil-in-oil emulsion crosslinking and used as anode materials. The SiCNO nanoparticles have an average particle size of around 9 nm and contain graphitic carbon and Si3N4 and SiO2 domains. Composite anodes are produced by mixing different concentrations of SiCNO nanoparticles, edge-functionalized graphene oxide, polyvinylidenefluoride, and carbon black Super P. The electrochemical behavior of the anode is investigated to evaluate the Li-ion storage performance of the composite anode and understand the mechanism of Li-ion storage. The lithiation of SiCNO is observed at ∼0.385 V versus Li/Li+. The anode has a large capacity of 705 mA h g-1 after 350 cycles at a current density of 0.1 A g-1 and shows an excellent cyclic stability with a capacity decay of 0.049 mA h g-1 (0.0097%) per cycle. SiCNO nanoparticles provide a large specific area that is beneficial to Li+ storage and cyclic stability. In situ transmission electron microscopy analysis demonstrates that the SiCNO nanoparticles exhibit extraordinary structural stability with 9.36% linear expansion in the lithiation process. The X-ray diffraction and X-ray photoelectron spectroscopy investigation of the working electrode before and after cycling suggests that Li+ was stored through two pathways in SiCNO lithiation: (a) Li-ion intercalation of graphitic carbon in free carbon domains and (b) lithiation of the SiO2 and Si3N4 domains through a two-stage process.

Synchronous Interface Modification and Bulk Passivation via a One-Step Cesium Bromide Diffusion Process for Highly Efficient Perovskite Solar Cells.

Perovskite film modification is one of the most effective methods to improve the performance of perovskite solar cells. The modification should follow its characters of an asymmetric structure and the corresponding charge transportation and extraction. In this work, it is shown that synchronous interface modification and bulk passivation for highly efficient PSCs can be achieved by a one-step cesium bromide (CsBr) diffusion process because it is more suitable for an asymmetric structure. The synchronous interface modification and bulk asymmetric passivation can be better applied to the asymmetric PSC structure and can boost the power conversion efficiency apparently from 19.5 to 22.1%. It is shown that the perovskite crystallization is improved and the charge extraction is also enhanced obviously due to the better band alignment matching. The diffusion of CsBr into the perovskite bulk could form a gradient distribution, which is more applicable to the asymmetric charge transport and extraction. Thus, the CsBr at the interface between the electronic transport layer (ETL) and perovskite, as well as in the perovskite bulk, could suppress charge recombination. All of these factors can improve the JSC and VOC as well as the power conversion efficiency (PCE) of the PSCs. The results point out that the studied method is a simple and efficient way to fabricate high-performance PSCs by interface modification and bulk asymmetric passivation in a single step.