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Abstract Non-radiative recombination of perovskite solar cells (PSCs) will increase as a result of the numerous crystallographic defects that the solution-grown perovskite films will cause, particularly at the grain boundary and film surface. As a result, it negatively influences the performance of the device. Consequently, lowering perovskite film defects is a useful strategy for raising the efficiency of PSCs. This study reports a grain regeneration and passivation approach that can decrease the recombination loss of the perovskite layer/charge transfer layer interface and the grain border. Guanidine iodide (GAI) treatment of perovskite films is the means by which this objective is accomplished. Unlike most methods that use GAI to post-treatment the perovskite layer or add GAI into the perovskite precursor solution, this work uses GAI for pre-treatment before spin coating the perovskite layer. It can effectively passivate surface defects and increase the grain size of perovskite films by controlling the crystallization process. The water stability of devices was enhanced, the short-circuit current (J sc), filling factor (FF), and power conversion efficiency (PCE) of PSCs were markedly improved, and non-radiative recombination was successfully reduced. The best efficiency of PSCs was 20.56% after the additional GAI treatment was applied to the perovskite layer, an 11.9% increase over the efficiency of the control device without GAI treatment. This method has the advantage of being simple and straightforward, providing a feasible pathway for the low-cost preparation and commercialization of PSCs.

Abstract Molecular ferroelectrics have garnered significant attention due to their structural tunability, low synthesis temperature, and high flexibility. Herein, we successfully synthesized imidazole perchlorate (ImClO4) single crystals and high-quality, highly-oriented thin films on Si substrates. These films demonstrated a high inverse piezoelectric coefficient of 55.7 pm/V. Two types of domain bands were observed: type-I bands tilted ~60° relative to the horizontal axis, and type-II bands positioned perpendicular to the horizontal axis. Under a + 20 V bias, type-I bands showed a reduction and detachment of 180° domain walls to form a needle-like domain. It extended toward the band boundary after applying −20 V bias, which grew along the boundary upon contact. In contrast, type-II bands showed straight domain wall motion and displayed a higher piezoresponse than type-I bands. The growth of high quality molecular ferroelectric thin films on Si substrates paves the way for the development of on-chip devices.

Abstract Current harmonics are generated at the switching frequency and its multiples when the traction converters are modulated. To address this, multi-trap filters are introduced, which are capable of selectively eliminating these specific harmonics to the limits set by IEEE 519-2014. This targeted removal significantly reduces the need for high total inductance, thereby allowing for a more compact filter design. Comparatively, to traditional inductor-capacitor-inductor (LCL) filters, more magnetic cores are needed for trap inductors. Furthermore, the traction systems have not been examined in conjunction with multi-trap filters. To reduce the filter size and investigate its application in traction converters, this paper presents an integrated double-trap LCL (DTLCL) filter. A tiny capacitor is connected in parallel with the grid-side inductor to form one LC-trap. In addition, another LC-trap is formed by connecting the equivalent trap inductor, introduced through the magnetic coupling between inverter-side and grid-side inductors, in series with the filter capacitor. The presented filters' features are thoroughly analyzed, and the design method has been developed. Finally, the simulation and hardware-in-the-loop (HIL) experiment results validate the proposed method's viability and efficacy. Compared to the discrete windings, the integrated ones enable a size decrease of two cores. Furthermore, the proposed filters can meet IEEE 519-2014 criteria with 0.3% for all the current switching harmonics and total harmonic distortion (THD) of 2.36% of the grid‐side current.

Abstract Electric field-induced second harmonic generation allows electrically controlling nonlinear light-matter interactions crucial for emerging integrated photonics applications. Despite its wide presence in materials, the figures-of-merit of electric field-induced second harmonic generation are yet to be elevated to enable novel device functionalities. Here, we show that the polar skyrmions, a topological phase spontaneously formed in PbTiO3/SrTiO3 ferroelectric superlattices, exhibit a high comprehensive electric field-induced second harmonic generation performance. The second-order nonlinear susceptibility and modulation depth, measured under non-resonant 800 nm excitation, reach ~54.2 pm V−1 and ~664% V−1, respectively, and high response bandwidth (higher than 10 MHz), wide operating temperature range (up to ~400 K) and good fatigue resistance (>1010 cycles) are also demonstrated. Through combined in-situ experiments and phase-field simulations, we establish the microscopic links between the exotic polarization configuration and field-induced transition paths of the skyrmions and their electric field-induced second harmonic generation response. Our study not only presents a highly competitive thin-film material ready for constructing on-chip devices, but opens up new avenues of utilizing topological polar structures in the fields of photonics and optoelectronics.

Abstract In ferroelectrics, complex interactions among various degrees of freedom enable the condensation of topologically protected polarization textures. Known as ferroelectric solitons, these particle-like structures represent a new class of materials with promise for beyond-CMOS technologies due to their ultrafine size and sensitivity to external stimuli. Such polarization textures have scarcely been demonstrated in multiferroics. Here, we present evidence for ferroelectric solitons in (BiFeO3)/(SrTiO3) superlattices. High-resolution piezoresponse force microscopy and Cs-corrected high-angle annular dark-field scanning transmission electron microscopy reveal a zoo of topologies, and polarization displacement mapping of planar specimens reveals center-convergent/divergent topological defects as small as 3 nm. Phase-field simulations verify that some of these structures can be classed as bimerons with a topological charge of ±1, and first-principles-based effective Hamiltonian computations show that the coexistence of such structures can lead to non-integer topological charges, a first observation in a BiFeO3-based system. Our results open new opportunities in multiferroic topotronics.

Abstract Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.

Abstract Solution growth of single-crystal ferroelectric oxide films has long been pursued for the low-cost development of high-performance electronic and optoelectronic devices. However, the established principles of vapor-phase epitaxy cannot be directly applied to solution epitaxy, as the interactions between the substrates and the grown materials in solution are quite different. Here, we report the successful epitaxy of single-domain ferroelectric oxide films on Nb-doped SrTiO3 single-crystal substrates by solution reaction at a low temperature of ~200 oC. The epitaxy is mainly driven by an electronic polarization screening effect at the interface between the substrates and the as-grown ferroelectric oxide films, which is realized by the electrons from the doped substrates. Atomic-level characterization reveals a nontrivial polarization gradient throughout the films in a long range up to ~500 nm because of a possible structural transition from the monoclinic phase to the tetragonal phase. This polarization gradient generates an extremely high photovoltaic short-circuit current density of ~2.153 mA/cm2 and open-circuit voltage of ~1.15 V under 375 nm light illumination with power intensity of 500 mW/cm2, corresponding to the highest photoresponsivity of ~4.306×10−3 A/W among all known ferroelectrics. Our results establish a general low-temperature solution route to produce single-crystal gradient films of ferroelectric oxides and thus open the avenue for their broad applications in self-powered photo-detectors, photovoltaic and optoelectronic devices.

Despite various known topological polar structures, the dynamic property of isolated ones is still poorly understood. Here, the authors show the controlled nucleation and ability to move of isolated three-fold vertices under an applied electric field.

Measurement(s) metagenomics analysis • Cytochrome C Oxidase Subunit 1 Technology Type(s) amplicon sequencing • Dideoxy Chain Termination DNA Sequencing Factor Type(s) tree species • geographic location • mean annual temperature • mean annual precipitation Sample Characteristic - Organism Fungi • Insecta Sample Characteristic - Environment dormant tree twigs Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.16764229

Extravasated erythrocytes in cerebrospinal fluid (CSF) contribute to the pathogenesis of subarachnoid haemorrhage (SAH). Here, the authors show that meningeal lymphatics drain extravasated erythorcytes and that blockage of this drainage aggravates SAH severity.

Abstract Tumor cells are characterized as redox-heterogeneous intracellular microenvironment due to the simultaneous overproduction of reactive oxygen species and glutathione. Rational design of redox-responsive drug delivery systems is a promising prospect for efficient cancer therapy. Herein, six paclitaxel-citronellol conjugates are synthesized using either thioether bond, disulfide bond, selenoether bond, diselenide bond, carbon bond or carbon-carbon bond as linkages. These prodrugs can self-assemble into uniform nanoparticles with ultrahigh drug-loading capacity. Interestingly, sulfur/selenium/carbon bonds significantly affect the efficiency of prodrug nanoassemblies. The bond angles/dihedral angles impact the self-assembly, stability and pharmacokinetics. The redox-responsivity of sulfur/selenium/carbon bonds has remarkable influence on drug release and cytotoxicity. Moreover, selenoether/diselenide bond possess unique ability to produce reactive oxygen species, which further improve the cytotoxicity of these prodrugs. Our findings give deep insight into the impact of chemical linkages on prodrug nanoassemblies and provide strategies to the rational design of redox-responsive drug delivery systems for cancer therapy.

Abstract The goal of this work was to investigate the tumor mutational burden (TMB) in Chinese patients with gynecologic cancer. In total, 117 patients with gynecologic cancers were included in this study. Both tumor DNA and paired blood cell genomic DNA were isolated from formalin-fixed paraffin-embedded (FFPE) specimens and blood samples, and next-generation sequencing was performed to identify somatic mutations. TP53, PTEN, ARID1A, and PIK3CA alterations were significantly different in various types of gynecologic cancers (p = 0.001, 1.15E-07, 0.004, and 0.009, respectively). The median TMB of all 117 gynecologic tumor specimens was 0.37 mutations/Mb, with a range of 0–41.45 mutations/Mb. Despite the lack of significant difference, endometrial cancer cases had a higher median TMB than cervical and ovarian cancer cases. Younger gynecologic cancer patients (age

The interaction of DOT1L with MLL oncogenic fusion proteins has been implicated in leukemogenesis. Here, the authors show a contrasting role for DOT1L in protecting UVR-induced melanomagenesis by facilitating DNA repair through interaction with XPC.

Abstract To determine whether cell sheets generated with long-term passaged (P10) aging human mesenchymal stromal cells (MSCs) could be used for bone tissue regeneration as tissue engineered periosteum in a femoral allograft mouse model similar to fresh passaged (P3) young MSCs. At 3 weeks after transplantation of MSC sheets, results showed more bony callus formed between allograft and host bone ends in both young P3 MSC and aged P10 MSC sheet-wrapped groups when compared to allograft alone. At 6 weeks, while both MSC sheet-wrapped allografts showed more bony callus formation when compared to allograft alone groups, the bony callus size in aged P10 MSC sheet groups was significantly less than young P3 MSC sheet groups. Biomechanical testing confirmed that P3 MSC sheet-grafted femurs had the highest biomechanical strength in the three groups. Histology sections showed that the area of the chondriod callus in the aged P10 MSC sheet groups was significantly larger than in P3 MSC sheet groups. Finally, a significant increase of chondro-osteoclast activity was observed in the P3 MSC sheet-grafted femur. Our data demonstrates that extensive long-term culture-induced MSC aging impaired their osteogenic ability and subsequent bony callus formation, and could be used to induce cartilaginous callus formation.

Abstract Oleanolic acid (OA), a pentacyclic triterpenoid, has been shown to modulate multiple signaling pathways in a variety of cell linages. But the mechanisms underlying OA-mediated mesenchymal stromal cell (MSC) osteogenic differentiation are not known. In this study, we examined effects of OA on cell viability, osteogenic differentiation in MSCs, and the involvement of Notch and BMP signaling. OA induced bone marrow derived MSC differentiation towards osteoprogenitor cells and inhibited Notch signaling in a dose dependent manner. Constitutive activation of Notch signaling fully blocked OA induced MSC osteogenic differentiation. The expression level of early osteogenic marker genes, ALP, Runx2, and type I collagen, which play a critical role in MSC to osteoblast transition and servers as a downstream target of BMP signaling, was significantly induced by OA. Furthermore, BMP2 mediated MSC osteogenic differentiation was significantly enhance by OA treatment, indicating a synergistic effect between BMP2 and OA. Our results suggest that OA is a promising bioactive agent for bone tissue regeneration, and inhibition of Notch signaling is required for its osteogenic effects on MSCs.

Abstract Osteosarcoma is the most common primary bone cancer in children and adolescents. In spite of aggressive treatment, osteosarcoma has a high mortality rate with minimal improvements in survival over past few decades. Polyphyllin I (PPI), a component in the traditional Chinese medicinal herb Paris polyphylla Smith, has been shown to have anti-tumor properties. However, its mechanism as an anti-osteosarcoma agent has not been well elucidated. In this study, we found that PPI suppressed osteosarcoma cell viability, arrested cell cycle in G2/M phase, induced apoptosis and inhibited invasion and migration of osteosarcoma cells. Moreover, PPI significantly suppressed intratibial primary tumor growth in xenograft orthotopic mouse model without any obvious side effects. These therapeutic efficacies were associated with inactivation of Wnt/β-catenin pathway, as PPI treatment decreased the amount of p-GSK-3β, leading to down-regulated levels of active β-catenin. PPI induced inhibition of osteosarcoma cell viability was abolished upon addition of GSK-3β specific inhibitor, CHIR99021, while PPI induced inhibition of osteosarcoma cell viability and migration were potentiated by β-catenin silencing. These findings suggested that, in vitro and in vivo, PPI treatment inhibited osteosarcoma, at least in part, via the inactivation of Wnt/β-catenin pathway. Thus, PPI could serve a novel therapeutic option for osteosarcoma patients.

Abstract We aimed to investigate the association between carotid plaques and cognitive impairment among patients with acute ischemic stroke, and to assess key clinical implications. In the Acute Ischemic Stroke Study, patients who received a cognitive testing and underwent complete carotid artery ultrasound scans were included. Cognitive function was measured by the mini-mental state examination. The cross-sectional relationships between cognitive impairment and carotid plaques were evaluated using multivariate logistic regression analysis. Of the 3116 patients included in this study, 826 (26.51%) patients were diagnosed with cognitive impairment. After adjusting for potential confounders, patients with ≥2 carotid plaques (odds ratio [OR] = 1.47; 95% confidence interval [CI]: 1.19–1.82), patients with ≥2 number of carotid arteries with plaque (OR = 1.48; 95% CI: 1.19–1.84) and patients with hypoechoic plaque (OR = 2.05; 95% CI: 1.24–3.38) are more likely to have cognitive impairment. In this acute ischemic stroke population, the number of carotid plaques, the number of carotid arteries with plaque and plaque stability are all associated with cognitive impairment.

Abstract The study aimed to evaluate whether the benefits of dual antiplatelet therapy would be influenced by blood pressure (BP) levels, among acute minor stroke or transient ischemic attack (TIA). In CHANCE (Clopidogrel in High-Risk Patients with Acute Nondisabling cerebrovascular Events) trail, Patients were stratified by systolic BP (SBP) and diastolic BP (DBP) level measured on admission, respectively, using the supine position BP within 24 hours after symptoms onset. The primary efficacy outcome was stroke recurrence, bleeding was the safety outcome. Patients with SBP ≥ 140 mmHg, dual antiplatelet treatment could reduce the risk of stroke recurrence significantly (HR 0.654, 95% CI 0.529–0.793, p

Abstract Thrombolysis treatment for patients with mild stroke is controversial. The aim of our study was to investigate whether patients with mild stroke or its specific etiologic subtype might benefit from rt-PA therapy. Data were derived from two cohorts of patients with and without rt-PA treatment: (1) the Thrombolysis Implementation and Monitor of Acute Ischemic Stroke in China (TIMS-China) and (2) the China National Stroke Registry (CNSR) database. Patients with mild stroke (defined as National Institutes of Health Stroke Scale ≤5) receiving the rt-PA therapy and without rt-PA therapy were matched in 1:2 for age, sex, stroke severity and etiologic subtype. A total of 134 rt-PA-treated patients were matched to 249 non-rt-PA-treated patients in the study. Among them, 104 (76%) rt-PA-treated patients with mild stroke had good outcome after 3 months compared with 173 (69.5%) non-rt-PA-treated matching cases (odds ratio [OR], 1.48; 95% confidence interval [CI], 0.91–2.43; P = 0.12). Compared with non-rt-PA-treated group, rt-PA-treated patients had good outcome after 3 months in those with stroke subtype of large-artery atherosclerosis (LAA) (80.5% vs 65.1%; OR, 2.19; 95%CI, 1.14–4.21; P = 0.02). For patients with mild stroke, intravenous rt-PA treatment may be effective. Patients with stroke subtype of LAA might benefit more from rt-PA treatment.