Chemical Bath Deposited Antimony Oxide Thin Films for Efficient Perovskite Solar Cells.

The metal oxide electron transport layers (ETLs) of n-i-p perovskite solar cells (PSCs) are dominated by TiO2 and SnO2, while the efficacy of the other metal oxide ETLs still lags far behind. Herein, an emerging, economical, and environmentally friendly metal oxide, antimony oxide (Sb2Ox, x = 2.17), prepared by chemical bath deposition is reported as an alternative ETL for PSCs. The deposited Sb2Ox film is amorphous and very thin (∼10 nm) but conformal on rough fluorine-doped tin oxide substrates, showing matched energy levels, efficient electron extraction, and then reduced nonradiative recombination in PSCs. The champion PSC based on the Sb2Ox ETL delivers an impressive power conversion efficiency of 24.7% under one sun illumination, which represents the state-of-the-art performance of all metal oxide ETL-based PSCs. Additionally, the Sb2Ox-based devices show improved operational and thermal stability compared to their SnO2-based counterparts. Armed with these findings, we believe this work offers an optional ETL for perovskites-based optoelectronic devices.

Fast Organic Cation Exchange in Colloidal Perovskite Quantum Dots toward Functional Optoelectronic Applications.

Colloidal quantum dots with lower surface ligand density are desired for preparing the active layer for photovoltaic, lighting, and other potential optoelectronic applications. In emerging perovskite quantum dots (PQDs), the diffusion of cations is thought to have a high energy barrier, relative to that of halide anions. Herein, we investigate the fast cross cation exchange approach in colloidal lead triiodide PQDs containing methylammonium (MA+) and formamidinium (FA+) organic cations, which exhibits a significantly lower exchange barrier than inorganic cesium (Cs+)-FA+ and Cs+-MA+ systems. First-principles calculations further suggest that the fast internal cation diffusion arises due to a lowering in structural distortions and the consequent decline in attractive cation-cation and cation-anion interactions in the presence of organic cation vacancies in mixed MA+-FA+ PQDs. Combining both experimental and theoretical evidence, we propose a vacancy-assisted exchange model to understand the impact of structural features and intermolecular interaction in PQDs with fewer surface ligands. Finally, for a realistic outcome, the as-prepared mixed-cation PQDs display better photostability and can be directly applied for one-step coated photovoltaic and photodetector devices, achieving a high photovoltaic efficiency of 15.05% using MA0.5FA0.5PbI3 PQDs and more precisely tunable detective spectral response from visible to near-infrared regions.

Atomic Imaging of Multi-Dimensional Ruddlesden-Popper Interfaces in Lead-Halide Perovskites.

Ruddlesden-Popper (RP) interface with defined stacking structure will fundamentally influence the optoelectronic performances of lead-halide perovskite (LHP) materials and devices. However, it remains challenging to observe the atomic local structures in LHPs, especially for multi-dimensional RP interface hidden inside the nanocrystal. In this work, the advantages of two imaging modes in scanning transmission electron microscopy (STEM), including high-angle annular dark field (HAADF) and integrated differential phase contrast (iDPC) STEM, are successfully combined to study the bulk and local structures of inorganic and organic/inorganic hybrid LHP nanocrystals. Then, the multi-dimensional RP interfaces in these LHPs are atomically resolved with clear gap and blurred transition region, respectively. In particular, the complex interface by the RP stacking in 3D directions can be analyzed in 2D projected image. Finally, the phase transition, ion missing, and electronic structures related to this interface are investigated. These results provide real-space evidence for observing and analyzing atomic multi-dimensional RP interfaces, which may help to better understand the structure-property relation of LHPs, especially their complex local structures.

Development of two novel on-site detection visualization methods for murine hepatitis virus based on the multienzyme isothermal rapid amplification.

Murine hepatitis virus (MHV) infection is one of the most prevalent types of mice infection in laboratory. MHV could cause death in mice and even interfere with the results in animal experiments. Herein, we developed two isothermal approaches based on the Multienzyme Isothermal Rapid Amplification (MIRA), for rapid detection of MHV in conserved M gene. We designed and screened several pairs of primers and probes and the isothermal fluorescence detector was applied for the exonuclease Ⅲ reverse transcription MIRA (exo-RT-MIRA) assay. To further simplify the workflow, the portable fluorescence visualization instrument, also as a palm-sized handheld system, was used for the naked-eye exo-RT-MIRA assay. The amplification temperature and time were optimized. The assay could be processed well at 42 °C 20 min for the exo-RT-MIRA and the naked-eye exo-RT-MIRA assay. The limit of detection (LoD) of the exo-RT-MIRA assay was 43.4 copies/µL. The LoD of the naked-eye exo-RT-MIRA assay was 68.2 copies/µL. No nonspecific amplifications were observed in the two assays. A total of 107 specimens were examined by qPCR and two assays developed. The experimental results statistical analysis demonstrated that the exo-RT-MIRA assay with the qPCR yielded sufficient agreement with a kappa value of 1.000 (p < 0.0001). The results also exhibited a good agreement (kappa value, 0.961) (p < 0.0001) between the naked-eye exo-RT-MIRA assay and the qPCR assay. In our study, the exo-RT-MIRA assay and the naked-eye exo-RT-MIRA assay presented the possibility of new methods in MHV point-of-testing diagnosis.

m6A facilitates hippocampus-dependent learning and memory through YTHDF1.

N6-methyladenosine (m6A), the most prevalent internal RNA modification on mammalian messenger RNAs, regulates the fates and functions of modified transcripts through m6A-specific binding proteins1-5. In the nervous system, m6A is abundant and modulates various neural functions6-11. Whereas m6A marks groups of mRNAs for coordinated degradation in various physiological processes12-15, the relevance of m6A for mRNA translation in vivo remains largely unknown. Here we show that, through its binding protein YTHDF1, m6A promotes protein translation of target transcripts in response to neuronal stimuli in the adult mouse hippocampus, thereby facilitating learning and memory. Mice with genetic deletion of Ythdf1 show learning and memory defects as well as impaired hippocampal synaptic transmission and long-term potentiation. Re-expression of YTHDF1 in the hippocampus of adult Ythdf1-knockout mice rescues the behavioural and synaptic defects, whereas hippocampus-specific acute knockdown of Ythdf1 or Mettl3, which encodes the catalytic component of the m6A methyltransferase complex, recapitulates the hippocampal deficiency. Transcriptome-wide mapping of YTHDF1-binding sites and m6A sites on hippocampal mRNAs identified key neuronal genes. Nascent protein labelling and tether reporter assays in hippocampal neurons showed that YTHDF1 enhances protein synthesis in a neuronal-stimulus-dependent manner. In summary, YTHDF1 facilitates translation of m6A-methylated neuronal mRNAs in response to neuronal stimulation, and this process contributes to learning and memory.

Controllable Colloidal Synthesis of MAPbI3 Perovskite Nanocrystals for Dual-Mode Optoelectronic Applications.

This study demonstrates an acetate ligand (AcO-)-assisted strategy for the controllable and tunable synthesis of colloidal methylammonium lead iodide (MAPbI3) perovskite nanocrystals (PNCs) for efficient photovoltaic and photodetector devices. The size of colloidal MAPbI3 PNCs can be tuned from 9 to 20 nm by changing the AcO-/MA ratio in the reaction precursor. In situ observations and detailed characterization results show that the incorporation of the AcO- ligand alters the formation of PbI6 octahedral cages, which controls PNC growth. A well-optimized AcO-/MA ratio affords MAPbI3 PNCs with a low defect density, a long carrier lifetime, and unique solid-state isotropic properties, which can be used to fabricate solution-processed dual-mode photovoltaic and photodetector devices with a conversion efficiency of 13.34% and a detectivity of 2 × 1011 Jones, respectively. This study provides an avenue to further the precisely controllable synthesis of hybrid PNCs for multifunctional optoelectronic applications.

High-Throughput Deposition of Recyclable SnO2 Electrodes toward Efficient Perovskite Solar Cells.

Chemical bath deposited (CBD) SnO2 is one of the most prevailing electron transport layers for realizing high-efficiency perovskite solar cells (PSCs) so far. However, the state-of-the-art CBD SnO2 process is time-consuming, contradictory to its prospect in industrialization. Herein, a simplified yet efficient method is developed for the fast deposition of SnO2 electrodes by incorporating a concentrated Sn source stabilized by the ethanol ligand with antimony (Sb) doping. The higher concentration of Sn source promotes the deposition rate, and Sb doping improves the hole-blocking capability of the CBD SnO2 layer so that its target thickness can be reduced to further save the deposition time. As a result, the deposition time can be appreciably reduced from 3-4 h to only 5 min while maintaining 95% of the maximum efficiency, indicating the power of the method toward high-throughput production of efficient PSCs. Additionally, the CBD SnO2 substrates are recyclable after removing the upper layers of complete PSCs, and the refurbished PSCs can maintain ≈98% of their initial efficiency after three recycling-and-fabrication processes.

Parkin-mediated mitophagy protects against aluminum trichloride-induced hippocampal apoptosis in mice via the mtROS-NLRP3 pathway.

Aluminum is a neurotoxic food contaminant. Aluminum trichloride (AlCl3) causes hippocampal mitochondrial damage, leading to hippocampal injury. Damaged mitochondria can release mitochondrial reactive oxygen species (mtROS) and activate nucleotide-binding oligomerization domain-like receptor-containing 3 (NLRP3) inflammasomes and apoptosis. E3 ubiquitin ligase PARK2 (Parkin)-mediated mitophagy can attenuate mitochondrial damage. However, the role of mitophagy in AlCl3-induced mice hippocampal damage and its regulatory mechanism remain elusive. First, C57BL/6 N mice were treated with 0, 44.825, 89.65, and 179.3 mg/kg body weight AlCl3 drinking water for 90 d. Apoptosis, NLRP3-inflammasome activation and mitochondrial damage were increased in AlCl3-induced hippocampal damage. In addition, Parkin-mediated mitophagy peaked in the middle-dose group and was slightly attenuated in the high-dose group. Subsequently, we used wild-type and Parkin knockout (Parkin-/-) mice to investigate the AlCl3-induced hippocampal damage. The results showed that Parkin-/- inhibited mitophagy, and aggravated AlCl3-induced mitochondrial damage, NLRP3-inflammasome activation, apoptosis and hippocampal damage. Finally, we administered MitoQ (mtROS inhibitor) and MCC950 (NLRP3 inhibitor) to AlCl3-treated Parkin-/- mice to investigate the mechanism of Parkin-mediated mitophagy. The results showed that inhibition of mtROS and NLRP3 attenuated hippocampal NLRP3-inflammasome activation, apoptosis, and damage in AlCl3-treated Parkin-/- mice. These findings indicate that Parkin-mediated mitophagy protects against AlCl3-induced hippocampal apoptosis in mice via the mtROS-NLRP3 pathway.

Ligand-Assisted Coupling Manipulation for Efficient and Stable FAPbI3 Colloidal Quantum Dot Solar Cells.

For emerging perovskite quantum dots (QDs), understanding the surface features and their impact on the materials and devices is becoming increasingly urgent. In this family, hybrid FAPbI3 QDs (FA: formamidium) exhibit higher ambient stability, near-infrared absorption and sufficient carrier lifetime. However, hybrid QDs suffer from difficulty in modulating surface ligand, which is essential for constructing conductive QD arrays for photovoltaics. Herein, assisted by an ionic liquid formamidine thiocyanate, we report a facile surface reconfiguration methodology to modulate surface and manipulate electronic coupling of FAPbI3 QDs, which is exploited to enhance charge transport for fabricating high-quality QD arrays and photovoltaic devices. Finally, a record-high efficiency approaching 15 % is achieved for FAPbI3 QD solar cells, and they retain over 80 % of the initial efficiency after aging in ambient environment (20-30 % humidity, 25 °C) for over 600 h.

Highly efficient A-site cation exchange in perovskite quantum dot for solar cells.

The mixed cation colloidal Cs1-XFAXPbI3 perovskite quantum dots (PQDs) obtained by cation exchange between CsPbI3 and FAPbI3 PQDs have been reported to exhibit enhanced photovoltaic performance. However, the cation exchange mechanism requires further in-depth investigation in terms of both material properties and device application. In this work, the impact of PQD weight ratio, PQD concentration, and host solvent polarity during cation exchange is comprehensively investigated for the first time. In addition, the whole exchange process under varying conditions is monitored by photoluminescence spectroscopy. As a result, we observe extremely fast cation exchange (∼20 min) under a condition at a CsPbI3/FAPbI3 PQD weight ratio of 1:1, a concentration of 70 mg/ml, and a host solvent using toluene. Moreover, we directly fabricate a PQD solar cell device using these obtained mixed cation Cs0.5FA0.5PbI3 PQDs and achieved an enhanced power conversion efficiency of 14.58%. We believe that these results would provide more insights into the cation exchange in emerging PQDs toward efficient photovoltaic fabrication and application.

T-2 toxin-induced femur lesion is accompanied by autophagy and apoptosis associated with Wnt/ß-catenin signaling in mice.

T-2 toxin is one of the most common mycotoxins found in grain foods, animal feed, and other agricultural by-products causing food contamination and health threat. The skeletal system is the main target tissue for T-2 toxin. T-2 toxin exposure is also recognized as a potential contributor to multiple types of bone diseases, including Kashin-Beck disease. However, the mechanisms of T-2 toxin-induced bone toxicity remain unclear. In this study, 60 male C57BL/6 mice were exposed T-2 toxin with 0, 0.5, 1 or 2 mg/kg body weight by intragastric administration for 28 days, respectively. Femora were collected for the detections of femur lesion, bone formation factors, oxidative stress, autophagy, apoptosis, and Wnt/ß-catenin signaling. Our research showed that T-2 toxin caused bone formation disorders, presenting as the reduction of the BMD and femur length, bone structure changes and abnormal bone formation proteins expressions, along with enhanced oxidative stress. Meanwhile, T-2 toxin increased expressions of autophagy-related proteins (Beclin 1, ATG5, p62, and LC3), and promoted apoptosis in mouse femur. Moreover, T-2 toxin suppressed the Wnt/ß-catenin signaling and expressions of downstream target genes. Taken together, our data indicated T-2 toxin-induced femur lesion was accompanied by autophagy and apoptosis, which was associated with Wnt/ß-catenin signaling.

Tailoring Phase Alignment and Interfaces via Polyelectrolyte Anchoring Enables Large-Area 2D Perovskite Solar Cells.

Ruddlesden-Popper phase 2D perovskite solar cells (PSCs) exhibit improved lifetime while still facing challenges such as phase alignment and up-scaling to module-level devices. Herein, polyelectrolytes are explored to tackle this issue. The contact between perovskite and hole-transport layer (HTL) is important for decreasing interfacial non-radiative recombination and scalable fabrication of uniform 2D perovskite films. Through exploring compatible butylamine cations, we first demonstrate poly(3-(4-carboxybutyl)thiophene-2,5-diyl)-butylamine (P3CT-BA) as an efficient HTL for 2D PSCs due to its great hydrophilicity, relatively high hole mobility and uniform surface. More importantly, the tailored P3CT-BA has an anchoring effect and acts as the buried passivator for 2D perovskites. Consequently, a best efficiency approaching 18 % was achieved and we further first report large-area (2×3 cm2 , 5×5 cm2 ) 2D perovskite minimodules with an impressive efficiency of 14.81 % and 11.13 %, respectively.

PK15 cell line stably overexpressing IL2 enhances PCV2 replication.

Porcine circovirus type 2 (PCV2) is the primary agent responsible for porcine circovirus-associated diseases (PCVADs), which is acknowledged as one of the most economically important diseases for the swine industry worldwide. Currently, the development of PCV2 vaccine against PCVADs and for other applications require large amounts of viral particles. The low propagation rate of PCV2 in vitro limits vaccine production. Previous studies showed that a cell line transfected with the porcine interleukin (IL)-2 gene gave higher PCV2 yield in vitro. However, transient transfection may become less effective and unstable after serial generations. In this work, we constructed a PK15 cell line with stable expression of porcine IL2 by lentivirus transfection. The results demonstrated that the transgenic cell line stably expressed IL2 protein significantly enhanced PCV2 replication. Thus, the transgenic PK15 cell line could be a promising cell line for vaccine production.

T-2 toxin causes dysfunction of Sertoli cells by inducing oxidative stress.

T-2 toxin is an inevitable mycotoxin in food products and feeds. It is a proven toxicant impairing the male reproductive system. However, previous studies have concentrated on the toxic effect of T-2 toxin on Leydig cells, with little attention on the Sertoli cell cytotoxicity. Therefore, this study aimed to establish the toxic mechanism of T-2 toxin on Sertoli cells. The Sertoli cell line (TM4 cell) was cultured and exposed to different concentrations of T-2 toxin with/without N-acetyl-L-cysteine (NAC) for 24 h. A CCK-8 assay then measured the cell viability. In addition, the expression of TM4 cell biomarkers (FSHR and ABP) and functional factors (occludin (Ocln), zonula occluden-1 (ZO-1), Connexin 43 (Cx-43), and N-Cadherin (N-cad)) were measured by qRT-PCR and Western blotting. The oxidative stress status (ROS, MDA, CAT, and SOD) and apoptosis rate, including the caspase-9, 8, and 3 activities in TM4 cells, were analyzed. We established that (1): T-2 toxin decreased TM4 cells viability and the half-maximal inhibitory concentration was 8.10 nM. (2): T-2 toxin-induced oxidative stress, evidenced by increased ROS and MDA contents, and inhibited CAT and SOD activities. (3): T-2 toxin inhibited FSHR, ABP, ocln, ZO-1, Cx-43, and N-Cad expressions. (4): T-2 toxin promoted TM4 cell apoptosis and caspase-9, 8, and 3 activities. (5): N-acetyl-L-cysteine relieved oxidative stress, functional impairment, and apoptosis in TM4 cells treated with T-2 toxin. Thus, T-2 toxin induced TM4 cell dysfunction through ROS-induced apoptosis.

Vegetation successions of coastal wetlands in southern Laizhou Bay, Bohai Sea, northern China, influenced by the changes in relative surface elevation and soil salinity.

Vegetation successions of coastal wetlands were influenced by the changes in relative surface elevation and soil salinity. In this study, the vegetation successions of coastal wetlands in southern Laizhou Bay and the factors influencing the successions were investigated by quadrat survey. The changes of relative surface elevation and soil salinity in coastal wetlands of the study region were caused by climate change, sea-level rise, coastal erosion, sedimentation, neotectonism, storm surge, seawater intrusion, invasion of Spatina alterniflora, and utilization of underground brine. The changes led to the regressive vegetation succession of coastal wetlands without the protection of sea embankment and the progressive vegetation succession of coastal wetlands with the protection of sea embankment. The invasion of S. alterniflora resulted in the regressive vegetation succession of wetlands in the riparian zone. The successions weakened the coastal wetlands' ecological capacities of carbon sequestration, pollutant purification, and resisting marine disasters, decreasing their species diversity. Some measures were proposed to resist the adverse impact of successions, such as introducing passenger water, storing water in flood season, digging 200 hm2 of ponds, and planting Salix matsudana and Tamarix chinensis around the ponds.

Effect of heat shock on murine norovirus replication in RAW264.7 cells.

Murine norovirus (MNV), is a prevalent pathogen of laboratory mice closely related to human norovirus (HuNoV), a contagious pathogen known to cause gastroenteritis worldwide; however, the mechanism of norovirus replication remains poorly understood. Both heat shock protein 90 (Hsp90) and heat shock protein 70 (Hsp70) play an important role in viral genome replication and viral gene expression. In this study, we first found that heat stress exerted a positive effect on the replication of MNV in the murine macrophage RAW264.7 cell line. Inhibition of Hsp70 and Hsp90 by the specific inhibitors, KNK437 and 17-AGG, respectively showed that Hsp70 and Hsp90 enhanced MNV genome replication and virion production. In addition, we found that KNK437 and 17-AGG could decrease the level of IL-1ß, IL-10, and TNF-α mRNA expression in MNV-infected cells. These data suggested that heat stress can positively regulate MNV replication, which advances our understanding of the molecular mechanism of MNV infection.

Molecular detection of Hsp90 inhibitor suppressing PCV2 replication in host cells.

Porcine Circovirus Type 2 (PCV2) is a pathogen that has the ability to cause devastating disease manifestations in pig populations with major economic implications. Our previous research found that Hsp90 is required for PCV2 production in PK-15 and 3D4/31 cells. The aim of this study was to evaluate the effect of Hsp90 inhibitor regulating PCV2 replication and to explore its underlying mechanism. In PK-15 and 3D4/31 cells treated with 17-AAG after viral adsorption, replication of PCV2 was attenuated as assessed by quantitating the expression of viral protein. Following NF-κB activation it was observed that 24hpi with PCV2 was significantly inhibited in the presence of 17-AAG. The expression of Hsp90 associated client proteins in PCV2-infected cells were also reduced in the presence of 17-AAG. However, treatment with MG-132 failed to rescue 17-AAG mediated reduction of PCV2 production in host cells. Thus, Hsp90 regulates PCV2 by modulating cellular signaling proteins. These results highlight the importance of cellular proteins during PCV2 infection and the possibility of targeting cellular chaperones for developing new anti-rotaviral strategies.

Atomically Dispersed Single Co Sites in Zeolitic Imidazole Frameworks Promoting High-Efficiency Visible-Light-Driven Hydrogen Production.

As photocatalysis technology could transform renewable and clean solar energy into green hydrogen (H2 ) energy through solar water splitting, it is regarded as the "Holy Grail" in chemistry field in the 21st century. Unfortunately, the bottleneck of this technique still lies in the exploration of highly active, cost-effective, and robust photocatalysts. This work reports the design and synthesis of a novel zeolitic imidazole framework (ZIF) coupled Zn0.8 Cd0.2 S hetero-structured photocatalyst for high-performance visible-light-induced H2 production. State-of-the-art characterizations and theoretical computations disclose that the interfacial electronic interaction between ZIF and Zn0.8 Cd0.2 S, the high distribution of Zn0.8 Cd0.2 S on ZIF, and the atomically dispersed coordinately unsaturated Co sites in ZIF synergistically arouse the significantly improved visible-light photocatalytic H2 production performance.

The Hsp90 inhibitor 17-DMAG decreases infection of porcine circovirus type 2 in mice.

Although several factors affecting porcine circovirus type 2 (PCV2) infection have been reported, their precise roles are far from clear. The aim of this study was to determine whether 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), an inhibitor of Hsp90, could significantly affect PCV2 infection and immune responses in BALB/c mice. Intraperitoneal injection of 17-DMAG significantly reduced viral loads in the blood and tissues of mice infected with PCV2, compared with control groups. The 17-DMAG treatment decreased serum interleukin (IL)-10 and tumor necrosis factor(TNF)-α levels, but it did not have a significant effect on the IL-1ß level. These data demonstrate that 17-DMAG is highly effective in suppressing PCV2 replication in BALB/c mice, indicating that it has potential value as an antiviral drug against PCV2 infection.