High-Order Harmonic Generation in Photoexcited Three-Dimensional Dirac Semimetals.

High-order harmonic generation (HHG) in condensed matter is highly important for potential applications in various fields, such as materials characterization, all-optical switches, and coherent light source generation. Linking HHG to the properties or dynamic processes of materials is essential for realizing these applications. Here, a bridge has been built between HHG and the transient properties of materials through the engineering of interband polarization in a photoexcited three-dimensional Dirac semimetal (3D-DSM). It has been found that HHG can be efficiently manipulated by the electronic relaxation dynamics of 3D-DSM on an ultrafast time scale of several hundred femtoseconds. Furthermore, time-resolved HHG (tr-HHG) has been demonstrated to be a powerful spectroscopy method for tracking electron relaxation dynamics, enabling the identification of electron thermalization and electron-phonon coupling processes and the quantitative extraction of electron-phonon coupling strength. This demonstration provides insights into the active control of HHG and measurements of the electron dynamics.

Manipulating electron redistribution between iridium and Co6Mo6C bridging with a carbon layer leads to a significantly enhanced overall water splitting performance at industrial-level current density.

Nowadays, alkaline water electrocatalysis is regarded as an economical and highly effective approach for large-scale hydrogen production. Highly active electrocatalysts functioning under large current density are urgently required for practical industrial applications. In this work, we present a meticulously designed methodology to anchor Ir nanoparticles on Co6Mo6C nanofibers (Co6Mo6C-Ir NFs) bridging with nitrogen-doped carbon as efficient bifunctional electrocatalysts with both excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity and stability in alkaline media. With a low Ir content of 5.9 wt%, Co6Mo6C-Ir NFs require the overpotentials of only 348 and 316 mV at 1 A cm-2 for the HER and OER, respectively, and both maintain stability for at least 500 h at ampere-level current density. Consequently, an alkaline electrolyzer based on Co6Mo6C-Ir NFs only needs a voltage of 1.5 V to drive 10 mA cm-2 and possesses excellent durability for 500 h at 1 A cm-2. Density functional theory calculations reveal that the introduction of Ir nanoparticles is pivotal for the enhanced electrocatalytic activity of Co6Mo6C-Ir NFs. The induced interfacial electron redistribution between Ir and Co6Mo6C bridging with nitrogen-doped carbon dramatically modulates the electron structure and activates inert atoms to generate more highly active sites for electrocatalysis. Moreover, the optimized electronic structure is more conducive to the balance of the adsorption and desorption energies of reaction intermediates, thus significantly promoting the HER, OER and overall water splitting performance.

Interface Engineering of the Cu1.5Mn1.5O4/CeO2 Heterostructure for Highly Efficient Electrocatalytic Nitrate Reduction to Ammonia.

The electrochemical nitrate reduction reaction (NO3RR) is considered a sustainable technology to convert the nitrate pollutants to ammonia. However, developing highly efficient electrocatalysts is necessary and challenging given the slow kinetics of the NO3RR with an eight-electron transfer process. Here, a Cu1.5Mn1.5O4 (CMO)/CeO2 heterostructure with rich interfaces is designed and fabricated through an electrospinning and postprocessing technique. Benefiting from the strong coupling between CMO and CeO2, the optimized CMO/CeO2-2 catalyst presents excellent NO3RR performance, with NH3 Faraday efficiency (FE) up to 93.07 ± 1.45% at -0.481 V vs reversible hydrogen electrode (RHE) and NH3 yield rate up to 48.06 ± 1.32 mg cm-2 h-1 at -0.681 V vs RHE. Theoretical calculations demonstrate that the integration of CeO2 with CMO modulates the adsorption/desorption process of the reactants and intermediates, showing a reduced energy barrier in the rate determination step of NO* to N* and achieving an outstanding NO3RR performance.

A novel MOF-808 derived material for oxidative desulfurization: the synergistic effect of hydrophobicity and electron transfer.

A functionalized modified metal-organic framework material, T-MOF-808, was synthesized through hydrophobic modification with tetraethyl orthosilicate (TEOS) and chlorotrimethylsilane (TMCS). Then a supported oxidative desulfurization catalyst, [C12Py]3(NH4)3Mo7O24/T-MOF-808(s), was prepared by using a heteropoly acid ionic liquid as the active component. The prepared samples were characterized using FT-IR, XRD, SEM, TEM, XPS, etc. [C12Py]3(NH4)3Mo7O24/T-MOF-808(s) was used in the oxidative desulfurization of dibenzothiophene (DBT). At the same time, the effects of different loadings of the active component, oxygen sulfur ratios, reaction temperatures, and reaction time were also investigated. [C12Py]3(NH4)3Mo7O24/T-MOF-808-15%(s) could oxidize 100% of DBT in 40 min at 60 °C. Significantly, the catalyst exhibited no discernible decline in catalytic activity after 14 runs. In addition, the efficiency of sulfur removal was 85.76% in actual diesel oil. It was found that the cooperative impact of hydrophobic modification and electron transfer makes an important contribution to the high activity. The hydrophobic modification provides a novel approach for using MOF materials in the oxidative desulfurization process.

Acoustic phonon excitation in gold probed by time-resolved photoemission electron microscopy.

Electron-phonon coupling is an important energy transfer mechanism in solids after ultrafast laser excitation. In this study, we present an extreme ultraviolet (EUV) and infrared (IR) pump-probe photoemission experiment to investigate the electron-phonon coupling in nonequilibrium gold. The energy of IR-laser-emitted photoelectrons is shifted due to the EUV photoemission and oscillates with a ∼4THz frequency. Such oscillation is considered as the effective excitation of the longitudinal acoustic phonon mode in gold through the spectral-dependent electron-phonon coupling. Our study showcases the capability of time-resolved photoemission electron microscopy to monitor the non-equilibrium lattice vibrations with ultrahigh spatial and temporal resolution.

Exposure to O3 and NO2 on the interfacial chemistry of the pulmonary surfactant and the mechanism of lung oxidative damage.

Exposure to ozone (O3) and nitrogen dioxide (NO2) are related to pulmonary dysfunctions and various lung diseases, but the underlying biochemical mechanisms remain uncertain. Herein, the effect of inhalable oxidizing gas pollutants on the pulmonary surfactant (PS, extracted from porcine lungs), a mixture of active lipids and proteins that plays an important role in maintaining normal respiratory mechanics, is investigated in terms of the interfacial chemistry using in-vitro experiments; and the oxidative stress induced by oxidizing gases in the simulated lung fluid (SLF) supplemented with the PS is explored. The results showed that O3 and NO2 individually increased the surface tension of the PS and reduced its foaming ability; this was accompanied by the surface pressure-area isotherms of the PS monolayers shifting toward lower molecular areas, with O3 exhibiting more severe effects than NO2. Moreover, both O3 and NO2 produced reactive oxygen species (ROS) resulting in lipid peroxidation and protein damage to the PS. The formation of superoxide radicals (O2•-) was correlated with the decomposition of O3 and the reactions of O3 and NO2 with antioxidants in the SLF. These radicals, in the presence of antioxidants, led to the formation of hydrogen peroxide and hydroxyl radicals (•OH). Additionally, the direct oxidation of unsaturated lipids by O3 and NO2 further caused an increase in the ROS content. This change in the ROS chemistry and increased •OH production tentatively explain how inhalable oxidizing gases lead to oxidative stress and adverse health effects. In summary, our results indicated that inhaled O3 and NO2 exposure can significantly alter the interfacial properties of the PS, oxidize its active ingredients, and induce ROS formation in the SLF. The results of this study provide a basis for the elucidation of the potential hazards of inhaled oxidizing gas pollutants in the human respiratory system.

Machine-Learning-Based Interatomic Potentials for Group IIB to VIA Semiconductors: Toward a Universal Model.

Rapid advancements in machine-learning methods have led to the emergence of machine-learning-based interatomic potentials as a new cutting-edge tool for simulating large systems with ab initio accuracy. Still, the community awaits universal interatomic models that can be applied to a wide range of materials without tuning neural network parameters. We develop a unified deep-learning interatomic potential (the DPA-Semi model) for 19 semiconductors ranging from group IIB to VIA, including Si, Ge, SiC, BAs, BN, AlN, AlP, AlAs, InP, InAs, InSb, GaN, GaP, GaAs, CdTe, InTe, CdSe, ZnS, and CdS. In addition, independent deep potential models for each semiconductor are prepared for detailed comparison. The training data are obtained by performing density functional theory calculations with numerical atomic orbitals basis sets to reduce the computational costs. We systematically compare various properties of the solid and liquid phases of semiconductors between different machine-learning models. We conclude that the DPA-Semi model achieves GGA exchange-correlation functional quality accuracy and can be regarded as a pretrained model toward a universal model to study group IIB to VIA semiconductors.

Highly diverse sputum microbiota correlates with the disease severity in patients with community-acquired pneumonia: a longitudinal cohort study.

BACKGROUND: Community-acquired pneumonia (CAP) is a common and serious condition that can be caused by a variety of pathogens. However, much remains unknown about how these pathogens interact with the lower respiratory commensals, and whether any correlation exists between the dysbiosis of the lower respiratory microbiota and disease severity and prognosis. METHODS: We conducted a retrospective cohort study to investigate the composition and dynamics of sputum microbiota in patients diagnosed with CAP. In total, 917 sputum specimens were collected consecutively from 350 CAP inpatients enrolled in six hospitals following admission. The V3-V4 region of the 16 S rRNA gene was then sequenced. RESULTS: The sputum microbiota in 71% of the samples were predominately composed of respiratory commensals. Conversely, 15% of the samples demonstrated dominance by five opportunistic pathogens. Additionally, 5% of the samples exhibited sterility, resembling the composition of negative controls. Compared to non-severe CAP patients, severe cases exhibited a more disrupted sputum microbiota, characterized by the highly dominant presence of potential pathogens, greater deviation from a healthy state, more significant alterations during hospitalization, and sparser bacterial interactions. The sputum microbiota on admission demonstrated a moderate prediction of disease severity (AUC = 0.74). Furthermore, different pathogenic infections were associated with specific microbiota alterations. Acinetobacter and Pseudomonas were more abundant in influenza A infections, with Acinetobacter was also enriched in Klebsiella pneumoniae infections. CONCLUSION: Collectively, our study demonstrated that pneumonia may not consistently correlate with severe dysbiosis of the respiratory microbiota. Instead, the degree of microbiota dysbiosis was correlated with disease severity in CAP patients.

Association Between the Improvement of Knowledge, Attitude and Practice of Hypertension Prevention and Blood Pressure Control-A Cluster Randomized Controlled Study.

BACKGROUND: Hypertension-related knowledge, attitude and practice (KAP) of hypertensive patients can affect the awareness, treatment and control of hypertension. However, little attention has been paid to the association between the change of hypertension preventive KAP and blood pressure (BP) control in occupational population using longitudinal data. We assess the effectiveness of a workplace-based multicomponent hypertension intervention program on improving the level of KAP of hypertension prevention, and the association between improvement in KAP and BP control during intervention. METHODS: From January 2013 to December 2014, workplaces across 20 urban regions in China were randomized to either the intervention group (n = 40) or control group (n = 20) using a cluster randomized control method. All employees in each workplace were asked to complete a cross-sectional survey to screen for hypertension patients. Hypertension patients in the intervention group were given a 2-year workplace-based multicomponent hypertension intervention for BP control. The level of hypertension prevention KAP and BP were assessed before and after intervention in the two groups. RESULTS: Overall, 3331 participants (2658 in the intervention group and 673 in the control group) were included (mean [standard deviation] age, 46.2 [7.7] years; 2723 men [81.7%]). After 2-year intervention, the KAP qualified rate was 63.2% in the intervention groups and 50.1% in the control groups (odds ratio = 1.65, 95% CI, 1.36∼2.00, P < .001). Compared with the control group decreased in the qualified rate of each item of hypertension preventive KAP questionnaire, all the items in the intervention group increased to different degrees. The increase of KAP score was associated with the decrease of BP level after intervention. For 1 point increase in KAP score, systolic blood pressure (SBP) decreased by .28 mmHg and diastolic blood pressure (DBP) decreased by .14 mmHg [SBP: ß = -.28, 95%CI: -.48∼-.09, P = .004; DBP: ß = -.14, 95%CI: -.26∼-.02, P = .024]. SBP and DBP was significantly in manual labor workers (SBP: ß = -.34, 95%CI: -.59∼-.09, P = .008; DBP: ß = -.23, 95%CI: -.38∼-.08, P = .003), workers from private enterprise, state-owned enterprise (SOE) (SBP: ß = -.40, 95%CI: -.64∼-.16, P = .001; DBP: ß = -.21, 95%CI: -.36∼-.06, P = .005) and a workplace with an affiliated hospital (SBP: ß = -.31, 95%CI: -.52∼-.11, P = .003; DBP: ß = -.16, 95%CI: -.28∼-.03, P = .016). The improvement of knowledge (SBP: ß = -.29, 95%CI: -.56∼-.02, P = .038; DBP: ß = -.12, 95%CI: -.29∼.05, P = .160), as well as attitude (SBP: ß = -.71, 95%CI: -1.25∼-.18, P = .009; DBP: ß = .18, 95%CI: -.23∼.59, P = .385) and behavior (SBP: ß = -.73, 95%CI: -1.22∼-.23, P = .004; DBP: ß = -.65, 95%CI: -.97∼-.33, P < .001) was gradually strengthened in relation to BP control. CONCLUSION: This study found that workplace-based multicomponent hypertension intervention can effectively improve the level of hypertension preventive KAP among employees, and the improvement of KAP levels were significantly associated with BP control. TRIAL REGISTRATION: Chinese Clinical Trial Registry No. ChiCTR-ECS-14004641.

Effects of loneliness and isolation on cardiovascular diseases: a two sample Mendelian Randomization Study.

BACKGROUND: Loneliness and isolation are associated with multiple cardiovascular diseases (CVDs), but there is a lack of research on whether they were causally linked. We conducted a Mendelian Randomization (MR) study to explore causal relationships between loneliness and isolation and multiple CVDs. METHODS: Single nucleotide polymorphisms associated with loneliness and isolation were identified from a genome-wide association study (GWAS) of 455,364 individuals of European ancestry in the IEU GWAS database. Summary data for 15 CVDs were also obtained from the IEU GWAS database. We used three MR methods including inverse variance weighting, MR-Egger, and weighted median estimation to assess the causal effect of exposure on outcomes. Cochran's Q test and MR-Egger intercept test were used to evaluate the heterogeneity and pleiotropy. RESULTS: MR analysis showed that loneliness and isolation were significantly associated with essential hypertension (OR = 1.07, 95% CI: 1.03-1.12), atherosclerotic heart disease (OR = 1.04; 95% CI: 1.02-1.06), myocardial infarction (OR = 1.02; 95% CI: 1-1.04) and angina (OR = 1.04; 95% CI =1.02-1.06). No heterogeneity and pleiotropy effects were found in this study. CONCLUSIONS: Causal relationship of loneliness and isolation with CVDs were found in this study.

Applications of Engineered Skin Tissue for Cosmetic Component and Toxicology Detection.

The scale of the cosmetic market is increasing every day. There are many safety risks to cosmetics, but they benefit people at the same time. The skin can become red, swollen, itchy, chronically toxic, and senescent due to the misuse of cosmetics, triggering skin injuries, with contact dermatitis being the most common. Therefore, there is an urgent need for a system that can scientifically and rationally detect the composition and perform a toxicological assessment of cosmetic products. Traditional detection methods rely on instrumentation and method selection, which are less sensitive and more complex to perform. Engineered skin tissue has emerged with the advent of tissue engineering technology as an emerging bioengineering technology. The ideal engineered skin tissue is the basis for building good in vitro structures and physiological functions in this field. This review introduces the existing cosmetic testing and toxicological evaluation methods, the current development status, and the types and characteristics of engineered skin tissue. The application of engineered skin tissue in the field of cosmetic composition detection and toxicological evaluation, as well as the different types of tissue engineering scaffold materials and three-dimensional (3D) organoid preparation approaches, is highlighted in this review to provide methods and ideas for constructing the next engineered skin tissue for cosmetic raw material component analysis and toxicological evaluation.

A comprehensive transformer-based approach for high-accuracy gas adsorption predictions in metal-organic frameworks.

Gas separation is crucial for industrial production and environmental protection, with metal-organic frameworks (MOFs) offering a promising solution due to their tunable structural properties and chemical compositions. Traditional simulation approaches, such as molecular dynamics, are complex and computationally demanding. Although feature engineering-based machine learning methods perform better, they are susceptible to overfitting because of limited labeled data. Furthermore, these methods are typically designed for single tasks, such as predicting gas adsorption capacity under specific conditions, which restricts the utilization of comprehensive datasets including all adsorption capacities. To address these challenges, we propose Uni-MOF, an innovative framework for large-scale, three-dimensional MOF representation learning, designed for multi-purpose gas prediction. Specifically, Uni-MOF serves as a versatile gas adsorption estimator for MOF materials, employing pure three-dimensional representations learned from over 631,000 collected MOF and COF structures. Our experimental results show that Uni-MOF can automatically extract structural representations and predict adsorption capacities under various operating conditions using a single model. For simulated data, Uni-MOF exhibits remarkably high predictive accuracy across all datasets. Additionally, the values predicted by Uni-MOF correspond with the outcomes of adsorption experiments. Furthermore, Uni-MOF demonstrates considerable potential for broad applicability in predicting a wide array of other properties.

Temporal-spatial analysis of transportation CO2 emissions in China: Clustering and policy recommendations.

Reducing transportation-related carbon dioxide (CO2) emissions in China poses significant challenges due to the sector's growth potential and variations among provinces and transportation modes. This study utilizes the bottom-up approach and the Logarithmic Mean Divisia Index (LMDI) decomposition method to calculate transportation CO2 emissions and explores the temporal-spatial differences across Chinese provinces. The results reveal that national transportation CO2 emissions increased by 50.14% from 2010 to 2019, and emissions from private cars present the fastest growth among all transportation modes by 254% over the decade. Spatially, higher emissions are found in eastern provinces, and neighboring provinces notably distinguish from each other in terms of the emission proportion of different modes and the factor analysis from LMDI. Regarding the heterogeneity of the spatial emission characteristics, a cluster-based evaluation method is proposed for the 31 provinces according to the emission structure and the LMDI decomposition. Four clusters are derived, each featuring varied emission distribution and driving factors. Correspondingly, policy recommendations are proposed to address the characteristics of each cluster, such as controlling car ownership, promoting integrated transport modes, improving fuel economy, and electrifying urban transportation services. The cluster-based analysis method can provide more specific suggestions to province targeting its emission characteristics rather than its location, which is one of the major contributions of this study.

Single-cell transcriptome analysis reveals tumoral microenvironment heterogenicity and hypervascularization in human carotid body tumor.

Carotid body tumor (CBT) is a rare neck tumor located at the adventitia of the common carotid artery bifurcation. The prominent pathological features of CBT are high vascularization and abnormal proliferation. However, single-cell transcriptome analysis of the microenvironment composition and molecular complexity in CBT has yet to be performed. In this study, we performed single-cell RNA sequencing (scRNA-seq) analysis on human CBT to define the cells that contribute to hypervascularization and chronic hyperplasia. Unbiased clustering analysis of transcriptional profiles identified 16 distinct cell populations including endothelial cells (ECs), smooth muscle cells (SMCs), neuron cells, macrophage cells, neutrophil cells, and T cells. Within the ECs population, we defined subsets with angiogenic capacity plus clear signs of later endothelial progenitor cells (EPCs) to normal ECs. Two populations of macrophages were detectable in CBT, macrophage1 showed enrichment in hypoxia-inducible factor-1 (HIF-1) and as well as an early EPCs cell-like population expressing CD14 and vascular endothelial growth factor. In addition to HIF-1-related transcriptional protein expression, macrophages1 also display a neovasculogenesis-promoting phenotype. SMCs included three populations showing platelet-derived growth factor receptor beta and vimentin expression, indicative of a cancer-associated fibroblast phenotype. Finally, we identified three types of neuronal cells, including chief cells and sustentacular cells, and elucidated their distinct roles in the pathogenesis of CBT and abnormal proliferation of tumors. Overall, our study provided the first comprehensive characterization of the transcriptional landscape of CBT at scRNA-seq profiles, providing novel insights into the mechanisms underlying its formation.

Identification of a highly conserved neutralizing epitope within the RBD region of diverse SARS-CoV-2 variants.

The constant emergence of SARS-CoV-2 variants continues to impair the efficacy of existing neutralizing antibodies, especially XBB.1.5 and EG.5, which showed exceptional immune evasion properties. Here, we identify a highly conserved neutralizing epitope targeted by a broad-spectrum neutralizing antibody BA7535, which demonstrates high neutralization potency against not only previous variants, such as Alpha, Beta, Gamma, Delta and Omicron BA.1-BA.5, but also more recently emerged Omicron subvariants, including BF.7, CH.1.1, XBB.1, XBB.1.5, XBB.1.9.1, EG.5. Structural analysis of the Omicron Spike trimer with BA7535-Fab using cryo-EM indicates that BA7535 recognizes a highly conserved cryptic receptor-binding domain (RBD) epitope, avoiding most of the mutational hot spots in RBD. Furthermore, structural simulation based on the interaction of BA7535-Fab/RBD complexes dissects the broadly neutralizing effect of BA7535 against latest variants. Therapeutic and prophylactic treatment with BA7535 alone or in combination with BA7208 protected female mice from the circulating Omicron BA.5 and XBB.1 variant infection, suggesting the highly conserved neutralizing epitope serves as a potential target for developing highly potent therapeutic antibodies and vaccines.

Interactions between inhalable aged microplastics and lung surfactant: Potential pulmonary health risks.

The relationship between microplastics (MPs) and human respiratory health has garnered significant attention since inhalation constitutes the primary pathway for atmospheric MP exposure. While recent studies have revealed respiratory risks associated with MPs, virgin MPs used as plastic surrogates in these experiments did not represent the MPs that occur naturally and that undergo aging effects. Thus, the effects of aged MPs on respiratory health remain unknown. We herein analyzed the interaction between inhalable aged MPs with lung surfactant (LS) extracted from porcine lungs vis-à-vis interfacial chemistry employing in-vitro experiments, and explored oxidative damage induced by aged MPs in simulated lung fluid (SLF) and the underlying mechanisms of action. Our results showed that aged MPs significantly increased the surface tension of the LS, accompanied by a diminution in its foaming ability. The stronger adsorptive capacity of the aged MPs toward the phospholipids of LS appeared to produce increased surface tension, while the change in foaming ability might have resulted from a variation in the protein secondary structure and the adsorption of proteins onto MPs. The adsorption of phospholipid and protein components then led to the aggregation of MPs in SLF, where the aged MPs exhibited smaller hydrodynamic diameters in comparison with the unaged MPs, likely interacting with biomolecules in bodily fluids to exacerbate health hazards. Persistent free radicals were also formed on aged MPs, inducing the formation of reactive oxygen species such as superoxide radicals (O2•-), hydrogen peroxide (HOOH), and hydroxyl radicals (•OH); this would lead to LS lipid peroxidation and protein damage and increase the risk of respiratory disease. Our investigation was the first-ever to reveal a potential toxic effect of aged MPs and their actions on the human respiratory system, of great significance in understanding the risk of inhaled MPs on lung health.

Dose-response association between physical activity and blood pressure among Chinese adults: a nationwide cross-sectional study.

OBJECTIVES: The aim of this study was to examine the dose-response associations of physical activity with blood pressure (BP) and hypertension risk among Chinese adults. METHODS: Derived from the national community-based China Hypertension Survey database during 2012--2015, a total of 203 108 residents aged at least 18 years were included. Individual-level physical activity was evaluated using a standardized questionnaire, and minutes of metabolic equivalent tasks per week (MET-min/week) were calculated, integrating domain, intensity, frequency, and duration. Multivariable linear and logistic regressions were used to estimate associations of physical activity with BP and hypertension risk, and restricted cubic spline regressions were performed for their nonlinear dose-response relationships. RESULTS: Overall, the median total physical activity (TPA) was 3213.0 MET-min/week and the prevalence of physical inactivity was 14.8%. TPA was negatively associated with BP. Increasing TPA levels was related to a steep decrease in systolic BP, up to approximately 2500 MET-min/week, with more modest benefits above that level of TPA. Higher levels of domain-specific and intensity-specific physical activity were found to be associated with lower BP levels and hypertension risk, except for the association between vigorous-intensity physical activity and systolic BP. We found that TPA within the range of 2000--4000 MET-min/week, a higher frequency and shorter duration were inversely associated with diastolic BP levels. CONCLUSION: Total, domain-specific, and intensity-specific physical activity were inversely related to BP levels, respectively, in a dose-response fashion. Of a given amount, higher-frequency, shorter-duration, and lower-intensity physical activity produced more beneficial effects.

Strain Regulation and Defect Passivation of FA-Based Perovskite Materials for Highly Efficient Solar Cells.

Formamidine lead triiodide (FAPbI3 ) perovskites have attracted increasing interest for photovoltaics attributed to the optimal bandgap, high thermal stability, and the record power conversion efficiency (PCE). However, the materials still face several key challenges, such as phase transition, lattice defects, and ion migration. Therefore, external ions (e.g., cesium ions (Cs+ )) are usually introduced to promote the crystallization and enhance the phase stability. Nevertheless, the doping of Cs+ into the A-site easily leads to lattice compressive strain and the formation of pinholes. Herein, trioctylphosphine oxide (TOPO) is introduced into the precursor to provide tensile strain outside the perovskite lattice through intermolecular forces. The special strain compensation strategy further improves the crystallization of perovskite and inhibits the ion migration. Moreover, the TOPO molecule significantly passivates grain boundaries and undercoordinated Pb2+ defects via the forming of P═O─Pb bond. As a result, the target solar cell devices with the synergistic effect of Cs+ and TOPO additives have achieved a significantly improved PCE of 22.71% and a high open-circuit voltage of 1.16 V (voltage deficit of 0.36 V), with superior stability under light exposure, heat, or humidity conditions.

Exosome Derived from Mesenchymal Stem Cells Alleviates Hypertrophic Scar by Inhibiting the Fibroblasts via TNFSF-13/HSPG2 Signaling Pathway.

Background: Mesenchymal stem cell-derived exosomes (MSC-exo) have been shown to have significant potential in wound healing and scar relief processes. According to reports, TNFSF13 and HSPG2 are associated with various fibrotic diseases. The aim of this study is to investigate how TNFSF13 and HSPG2 affect the formation of hypertrophic scar (HS) and the mechanism by which exosomes regulate HS. Methods: Immunohistochemistry, qRT-PCR, Western blot, and immunofluorescence were performed to measure TNFSF13 expression in HS skin tissues and hypertrophic scar fibroblast (HSF). HSF were treated with recombinant TNFSF13 protein and TNFSF13 siRNAs to probe the effect of TNFSF13 on the activity of HSF. The CCK-8, EdU, Transwell, and Western blot were used to investigate the role of TNFSF13 in viability, proliferation and inflammation. The influence of MSC-exo on the proliferation and function of HSF was determined by scratch and Western blot. Results: TNFSF13 was dramatically up-regulated in HS skin tissues and HSF. Recombinant TNFSF13 protein increased cell viability, proliferation, migration, fibrosis, inflammation, and the binding between TNFSF13 and HSPG2 of HSF. The opposite results were obtained in TNFSF13 siRNAs transferred HSF. Furthermore, TNFSF13 activated the nuclear factor-κB (NF-κB) signaling pathway. Silencing of HSPG2 and inhibition of NF-κB remarkably eliminated the promoting effects of TNFSF13 on cell viability, proliferation, migration, fibrosis and inflammation of HSF. MSC-exo reduced α-SMA and COL1A1 inhibited the proliferation and migration of HSF by inhibiting TNFSF13 and HSPG2. Conclusion: TNFSF13 activates NF-κB signaling pathway by interacting with HSPG2, which regulates the proliferation, migration, fibrosis and inflammatory response of HSF. Through the above mechanisms, knocking out TNFSF13 can inhibit the proliferation, migration, fibrosis and inflammatory response of HSF, whereas MSC-exo could reverse this process. These results suggest that MSC-exo alleviates HS by inhibiting the fibroblasts via TNFSF-13/HSPG2 signaling pathway.