Tuneable Efficient White Emission of Sb3+/Mn2+ Co-Doped Lead-Free Perovskites for Single-Component White Light-Emitting Diodes.

Inorganic lead-free perovskite nanocrystals (NCs) with broadband self-trapped exciton (STEs) emission and low toxicity have shown enormous application prospects in the field of display and lighting. However, white light-emitting diodes (WLEDs) based on a single-component material with high photoluminescence quantum yield (PLQY) remain challenging. Here, we demonstrate a novel codoping strategy by introducing Sb3+/Mn2+ ions to achieve the tuneable dual emission in lead-free perovskite Cs3InCl6 NCs. The PLQY increases to 59.64% after doping with Sb3+. The codoped Cs3InCl6 NCs exhibit efficient white light emission due to the energy transfer channel from STEs to Mn2+ ions with PLQY of 51.38%. Density functional theory (DFT) calculations have been used to verify deeply the effects of Sb3+/Mn2+ doping. WLEDs based on Sb3+/Mn2+-codoped Cs3InCl6 NCs are explored with color rendering index of 85.5 and color coordinate of (0.398, 0.445), which have been successfully applied as photodetector lighting sources. This work provides a new perspective for designing novel lead-free perovskites to achieve single-component WLEDs.

The Voltage-Adaptive Effect in Lithium-Sulfur Batteries Integrated with an Electron-Conductive Interlayer.

Lithium-sulfur (Li-S) batteries are considered as one of the top competitors to go beyond Li-ion batteries. However, the shuttle effect triggered by soluble lithium polysulfides (LPSs) brings great troubles for understanding the solid-liquid-solid conversion process of the sulfur cathode. Herein, a new characterization technique is developed to deepen the understanding of such soluble LPSs shuttling, by integrating an electron-conductive interlayer. The voltage of the interlayer exhibits a voltage-adaptive effect to the cathode, indicating the true dependence of the open-circuit voltages on the LPSs instead of on the solid cathodes. Furthermore, a quantitative method can be introduced to monitor the shuttling LPSs by such interlayer design, and it shows great potential to be a new standard technique, providing direct comparison of the shuttle effect between different studies. The newly developed interlayer design paves an avenue to gain new insight into the reaction process and improve the performance of Li-S batteries.

[Emission Inventory of Airborne Pollutants from Biomass Combustion in Guizhou Province].

With the objective to ascertain the emissions of biomass combustion in Guizhou, the activity levels were measured through data collection and field surveys, and the emission factors were acquired using actual monitoring data and data cited from previous literature. A 3 km×3 km-gridded emission inventory of nine air pollutants from biomass combustion sources in Guizhou Province in 2019 was developed in combination with GIS technology. The results showed that the total emissions of CO, NOx, SO2, NH3, VOCs, PM2.5, PM10, BC, and OC in Guizhou were estimated to be 293505.53, 14781.19, 4146.11, 8501.07, 45025.70, 39463.58, 41879.31, 6832.33, and 15134.74 t, respectively. The distribution of atmospheric pollutants emitted by biomass combustion sources in different cities was noticeably uneven, being mainly concentrated in Qiandongnan Miao and Dong Autonomous Prefecture. The analysis of variation characteristics of emissions indicated that the monthly emissions were concentrated in February, March, April, and December, and the hourly emissions peaked daily from 14:00 to 15:00. Some uncertainty remained in the emission inventory. It is necessary to perform in-depth analyses of the accuracy of obtaining activity-level data, localize the emission factors through more combustion experiments in subsequent research for improving the emission inventory of air pollutants from biomass combustion in Guizhou Province, and provide a basis for the cooperative governance of the atmospheric environment.

Regulatory Mechanisms of bHLH Transcription Factors in Plant Adaptive Responses to Various Abiotic Stresses.

Basic helix-loop-helix proteins (bHLHs) comprise one of the largest families of transcription factors in plants. They have been shown to be involved in responses to various abiotic stresses, such as drought, salinity, chilling, heavy metal toxicity, iron deficiency, and osmotic damages. By specifically binding to cis-elements in the promoter region of stress related genes, bHLHs can regulate their transcriptional expression, thereby regulating the plant's adaptive responses. This review focuses on the structural characteristics of bHLHs, the regulatory mechanism of how bHLHs are involved transcriptional activation, and the mechanism of how bHLHs regulate the transcription of target genes under various stresses. Finally, as increasing research demonstrates that flavonoids are usually induced under fluctuating environments, the latest research progress and future research prospects are described on the mechanisms of how flavonoid biosynthesis is regulated by bHLHs in the regulation of the plant's responses to abiotic stresses.

Synthesis, Structure, and Reactivity of Acid-Free Neutral Oxoborane.

An efficient synthesis of an acid-free neutral oxoborane of the type carboranyl-B(carbene)=O has been developed via a serendipitous discovery from the reaction of 1,2-[BBr(carbene)]-o-carborane with AgOTf. This represents a new type of oxoborane. The stabilization of this oxoborane may be attributed to 1) kinetic stabilization provided by a bulky 3D carboranyl ligand and 2) thermodynamic stabilization offered by a carbene ligand. Crystallographic analyses support the presence of the shortest terminal B=O double bond ever reported thus far. Its reactivity has also been examined.

WinRoots: A High-Throughput Cultivation and Phenotyping System for Plant Phenomics Studies Under Soil Stress.

Soil stress, such as salinity, is a primary cause of global crop yield reduction. Existing crop phenotyping platforms cannot fully meet the specific needs of phenomics studies of plant response to soil stress in terms of throughput, environmental controllability, or root phenotypic acquisition. Here, we report the WinRoots, a low-cost and high-throughput plant soil cultivation and phenotyping system that can provide uniform, controlled soil stress conditions and accurately quantify the whole-plant phenome, including roots. Using soybean seedlings exposed to salt stress as an example, we demonstrate the uniformity and controllability of the soil environment in this system. A high-throughput multiple-phenotypic assay among 178 soybean cultivars reveals that the cotyledon character can serve as a non-destructive indicator of the whole-seedling salt tolerance. Our results demonstrate that WinRoots is an effective tool for high-throughput plant cultivation and soil stress phenomics studies.

Global and Local Tensor Factorization for Multi-criteria Recommender System.

In multi-criteria recommender systems, matrix factorization characterizes users and items via latent factor vectors inferred from user-item rating patterns. However, two-dimensional matrix factorization models may not be able to cope with the recommendation problem that involves additional criterion-specific rating data. This study introduces a tensor factorization method to handle three-dimensional user-item-criterion rating data. Moreover, we observe that using single global tensor factorization alone may not be sufficient to characterize diverse preferences among different groups of users, and a combined global and local tensor factorization method (GLTF) for multi-criteria recommendation is thus proposed. One key benefit of the GLTF is that it can leverage global user-item-criterion rating patterns while also exploiting local user-subset specific rating behaviors to jointly infer the latent factor representations for users, items, and specific item criteria. Experimental results, which used real-life data available to the public, demonstrated that the GLTF is superior to well-established baseline methods.

The salt-induced transcription factor GmMYB84 confers salinity tolerance in soybean.

Transcription factor activation and DNA methylation are important plant responses to abiotic stress. Here, we established that the salinity stress-induced expression of the soybean (Glycine max) transcription factor-encoding gene GmMYB84 relies on DNA methylation. The level of DNA methylation at sequences 690 nt to 950 nt upstream of the GmMYB84 transcription initiation codon was markedly reduced in plants exposed to salinity stress, resulting in a higher abundance of transcripts. When challenged with salinity stress, plants constitutively expressing GmMYB84 outperformed untransformed plants with respect to their germination rate, primary root elongation, proline accumulation, antioxidant enzyme activity, membrane integrity, and K+ levels. Arabidopsis thaliana plants heterologously expressing GmMYB84 were more tolerant to salt stress and exhibited higher germination rates than the wild type. Electrophoretic mobility shift assays revealed that GmMYB84 binds to the cis-regulatory sequences of GmAKT1, the homolog of ARABIDOPSIS K+ TRANSPORTER 1 (AKT1). Thus, DNA methylation modulates the salinity stress-induced expression of the soybean transcription factor-encoding gene GmMYB84 and thereby confers salinity stress tolerance.

Catalytic Regioselective Cage B(8)-H Arylation of o-Carboranes via "Cage-Walking" Strategy.

A proof-of-concept example of catalytic regioselective cage B(8)-H functionalization of o-carboranes has been disclosed for the first time. Under the help of an acylamino directing group at cage B(3), a series of B(8)-arylated, B(4,7,8)-triarylated and B(4,7,8)-trifluorinated o-carborane derivatives were conveniently prepared. On the basis of isolation of a key intermediate, deuterium labeling experiments and DFT calculations, a reaction mechanism involving a high-valent palladium induced "cage-walking" from B(4) to B(8) vertex is proposed to account for the regioselective B(8)-H activation.

Gastrointestinal non-motor dysfunction in Parkinson's disease model rats with 6-hydroxydopamine.

Parkinson's disease (PD) is a neurodegenerative disease with a progressive loss of mesencephalic dopaminergic neurons of the substantia nigra (SN). To further evaluate its pathophysiology, accurate animal models are needed. The current study aims to verify the impact of a 6-hydroxydopamine (6-OHDA) bilateral microinjection into the SN on gastrointestinal symptoms in rats and confirm that the 6-OHDA rat model is an appropriate tool to investigate the mechanisms of Parkinsonian GI disorders. Immunohistochemistry, digital X-ray imaging, short-circuit current, FITC-dextran permeability and ultra-performance liquid chromatography tandem mass spectrometry were used in this study. The results indicated that the dopaminergic neurons in SN and fibres in the striatum were markedly reduced in 6-OHDA rats. The 6-OHDA rats manifested reductions in occupancy in a rotarod test and increases in daily food debris but no difference in body mass or daily consumption. Compared with control rats, faecal pellets and their contents were significantly decreased, whereas gastric emptying and intestinal transport were delayed in 6-OHDA rats. The increased in vivo FITC-dextran permeability and decreased intestinal transepithelial resistance in the model suggest attenuated barrier function in the digestive tract in the PD model. Moreover, inflammatory factors in the plasma showed that pro-inflammatory factors IL-1? and IL-8 were significantly increased in 6-OHDA rats. Collectively, these findings indicate that the model is an interesting experimental tool to investigate the mechanisms involved in the progression of gastrointestinal dysfunction in PD.

Artificial Synapses Emulated by an Electrolyte-Gated Tungsten-Oxide Transistor.

Considering that the human brain uses ≈1015 synapses to operate, the development of effective artificial synapses is essential to build brain-inspired computing systems. In biological synapses, the voltage-gated ion channels are very important for regulating the action-potential firing. Here, an electrolyte-gated transistor using WO3 with a unique tunnel structure, which can emulate the ionic modulation process of biological synapses, is proposed. The transistor successfully realizes synaptic functions of both short-term and long-term plasticity. Short-term plasticity is mimicked with the help of electrolyte ion dynamics under low electrical bias, whereas the long-term plasticity is realized using proton insertion in WO3 under high electrical bias. This is a new working approach to control the transition from short-term memory to long-term memory using different gate voltage amplitude for artificial synapses. Other essential synaptic behaviors, such as paired pulse facilitation, the depression and potentiation of synaptic weight, as well as spike-timing-dependent plasticity are also implemented in this artificial synapse. These results provide a new recipe for designing synaptic electrolyte-gated transistors through the electrostatic and electrochemical effects.

Toward Switchable Photovoltaic Effect via Tailoring Mobile Oxygen Vacancies in Perovskite Oxide Films.

The defect chemistry of perovskite oxides involves the cause to most of their abundant functional properties, including interface magnetism, charge transport, ionic exchange, and catalytic activity. The possibility to achieve dynamic control over oxygen anion vacancies offers a unique opportunity for the development of appealing switchable devices, which at present are commonly based on ferroelectric materials. Herein, we report the discovery of a switchable photovoltaic effect, that the sign of the open voltage and the short circuit current can be reversed by inverting the polarity of the applied field, upon electrically tailoring the distribution of oxygen vacancies in perovskite oxide films. This phenomenon is demonstrated in lateral photovoltaic devices based on both ferroelectric BiFeO3 and paraelectric SrTiO3 films, under a reversed applied field whose magnitude is much smaller than the coercivity value of BiFeO3. The migration of oxygen vacancies was directly observed by employing an advanced annular bright-field scanning transmission electron microscopy technique with in situ biasing equipment. We conclude that the band bending induced by the motion of oxygen vacancies is the driving force for the reversible switching between two photovoltaic states. The present work can provide an active path for the design of novel switchable photovoltaic devices with a wide range of transition metal oxides in terms of the ionic degrees of freedom.

High-performance visible blind ultraviolet photodetector based on KTaO3 single crystal.

We report a visible-blind ultraviolet photoconductive detector with interdigitated electrodes based on KTaO3 (KTO) single crystals. Both the steady spectral responses and the transient photovoltaic measurements clearly exhibit a cutoff wavelength at 344 nm (∼3.6 eV), in accordance with the bandgap of KTO. The KTO photodetectors show a low dark current ∼1.5 pA at 20 V, and a high UV-to-visible rejection ratio with 3 orders of magnitude at room temperature. The quantum efficiency is 37.49% under 20 V bias, and the detectivity D* of 3.85×1012 cm·Hz0.5/W, which is comparable to that of silicon photodetectors in the UV region. The rise time of photoelectric response is ∼260 ps, indicating an ultrafast photoelectric response characteristic. The present work offers appealing prospects for the application of KTO materials in high-performance visible blind ultraviolet photodetectors.

The association between polymorphism of P53 Codon72 Arg/Pro and hepatocellular carcinoma susceptibility: evidence from a meta-analysis of 15 studies with 3,704 cases.

Emerging evidence has shown that p53gene participates in human carcinogenesis as tumor suppressors. Polymorphism of p53 gene codon72 arginine (Arg)/proline (Pro) (rs1042522) may influence the function of p53 protein and then affect the processing of carcinogenesis. It has been suggested that p53 codon72 Arg/Pro polymorphism is associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. To examine the validity of the association between the polymorphism and HCC risk, we performed this meta-analysis. We have conducted a search of case-control studies on the associations of p53 codon72 polymorphism with susceptibility to HCC in PubMed, ScienceDirect, BioMed central, Springer, EBSCO, Wanfang databases, and Chinese National Knowledge Infrastructure databases. A total of 15 studies were identified with 3,704 cases and 4,559 controls for codon72 Arg/Pro polymorphism. The result did support a significant genetic association between Pro allele and susceptibility to HCC in all the genetic models. Similarly, subgroup analysis showed significant associations between the Arg/Pro polymorphism and susceptibility to HCC when stratifying by race, gender, source of controls, and hepatitis virus infection status. This meta-analysis suggests that p53 codon72 Arg/Pro polymorphism may be associated with the risk of HCC, especially in subgroup analysis of Asian and Caucasian population, hospital-based population, the female, and the individuals infected with hepatitis virus. However, well-designed studies based on different ethnic groups with larger sample size and more detailed data are needed to confirm these conclusions.

The association between two common polymorphisms in MicroRNAs and hepatocellular carcinoma risk in Asian population.

BACKGROUND: Emerging evidence has shown that microRNAs (miRNAs) participate in human carcinogenesis as tumor suppressors or oncogenes. Single nucleotide polymorphism (SNP) located in the miRNAs may influence the function of mature miRNAs and then affect the processing of carcinogenesis. It has been suggested that two common SNPs rs2910164 in miR-146a and rs3746444 in miR-499 are associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. To acquire a more precise effect of the association between these polymorphisms and HCC risk, we performed this meta-analysis. METHODOLOGY/PRINCIPAL FINDINGS: We have conducted a search of case-control studies on the associations of SNPs rs2910164 and/or rs3746444 with susceptibility to HCC in PubMed, ScienceDirect, Cochrane Central Register of Controlled Trials, and Chinese National Knowledge Infrastructure databases for the period up to Sep 10th, 2012. A total of 6 studies were identified with 2071 cases and 2350 controls for miR-146a rs2910164 polymorphism, 667 cases and 1006 controls for miR-499 rs3746444 polymorphism. It was found that neither allele frequency nor genotype distribution of the two polymorphisms was associated with risk of HCC in all genetic models. Similarly, subgroup analysis in Asian population showed no associations between the two SNPs and the susceptibility to HCC. CONCLUSIONS/SIGNIFICANCE: This meta-analysis suggests that miR-146a rs2910164 and miR-499 rs3746444 polymorphisms may not be associated with the risk of HCC, especially for Asian population. However, well-designed studies with larger sample size and more detailed data are needed to confirm these conclusions.

The association between polymorphism of P53 codon 72 Arg/Pro and hepatocellular carcinoma susceptibility: evidence from a meta-analysis of 15 studies with 3704 cases.

BACKGROUND: Emerging evidence has shown that p53gene participates in human carcinogenesis as tumor suppressors. Polymorphism of p53 gene codon 72 Arg/Pro (rs1042522) may influence the function of p53 protein and then affect the processing of carcinogenesis. It has been suggested that p53 codon 72 Arg/Pro polymorphism is associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. To examine the validity of the association between the polymorphism and HCC risk, we performed this meta-analysis. METHODOLOGY/PRINCIPAL FINDINGS: We have conducted a search of case-control studies on the associations of p53 codon 72 polymorphism with susceptibility to HCC in PubMed, ScienceDirect, Bio-Med central, Springer-link, EBSCO, Wanfang databases and Chinese National Knowledge Infrastructure (CNKI) databases. A total of 15 studies were identified with 3704 cases and 4559 controls for codon 72 Arg/Pro polymorphism. The result did support a significant genetic association between Pro allele and susceptibility to HCC in all the genetic models. Similarly, subgroup analysis showed significant associations between the Arg/Pro polymorphism and susceptibility to HCC when stratifying by race, gender, source of controls and hepatitis virus infection status. CONCLUSIONS/SIGNIFICANCE: This meta-analysis suggests that p53 codon 72 Arg/Pro polymorphism may be associated with the risk of HCC, especially in subgroup analysis of Asian and Caucasian population, hospital-based population, the female, and the individuals infected with hepatitis virus. However, well-designed studies based on different ethnic groups with larger sample size and more detailed data are needed to confirm these conclusions.