Building a Charge Transfer Bridge between g-C3N4 and Perovskite with Molecular Engineering to Achieve Efficient Perovskite Solar Cells.

Effective defect passivation and efficient charge transfer within polycrystalline perovskite grains and corresponding boundaries are necessary to achieve highly efficient perovskite solar cells (PSCs). Herein, focusing on the boundary location of g-C3N4 during the crystallization modulation on perovskite, molecular engineering of 4-carboxyl-3-fluorophenylboronic acid (BF) on g-C3N4 was designed to obtain a novel additive named BFCN. With the help of the strong bonding ability of BF with both g-C3N4 and perovskite and favorable intramolecular charge transfer within BFCN, not only has the crystal quality of perovskite films been improved due to the effective defects passivation, but the charge transfer has also been greatly accelerated due to the formation of additional charge transfer channels on the grain boundaries. As a result, the champion BFCN-based PSCs achieve the highest photoelectric conversion efficiency (PCE) of 23.71% with good stability.

Review on NMR as a tool to analyse natural products extract directly: Molecular structure elucidation and biological activity analysis.

INTRODUCTION: Natural products, the small organic molecules produced by plants, microbes and invertebrates, often present in the form of a mixture, this leads to the structural characterisation of natural extracts often requiring time-consuming multistep purification procedures. Nuclear magnetic resonance (NMR) technology is traditionally utilised as a tool for the structural elucidation of pure compounds. Contemporarily, an up-to-date trend in the application of NMR in natural product research is shifting to the direct NMR analysis of crude mixtures, to obtain molecular structure and biological activity information without performing cumbersome separation. OBJECTIVE: To review works of literature on the evolution, principle and progress of NMR technologies for analysing mixtures, we focus on the successful application of NMR technologies in direct analysis of natural product extracts. METHODOLOGY: Based on our research experience, academic tracking and extensive literature search, which involved, but not limited to, the use of various databases, like Web of Knowledge and PubMed. The keywords used, in various combinations, to retrieve recent literature on the successful application of NMR technologies to sheer natural product extracts, and excluded artificially natural product mixture and biofluid. RESULTS: NMR technologies for direct natural extracts analysis, including two-dimensional J-resolved spectroscopy (2D-JRES), pure shift NMR, diffusion-ordered NMR spectroscopy (DOSY), statistical correlation spectroscopy (STOCSY), concentration-ordered NMR spectroscopy (CORDY), saturation transfer difference (STD) and water-ligand observed via gradient spectroscopy (WaterLOGSY) were illustrated. CONCLUSIONS: By these methods, molecular structure and biological activity information will be directly obtained from NMR analysis of natural products extract, aiming to save experimental time and expenses.

Identification of QTL, QTL-by-environment interactions, and their candidate genes for resistance HG Type 0 and HG Type 1.2.3.5.7 in soybean using 3VmrMLM.

Introduction: Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is an important disease affecting soybean yield in the world. Potential SCN-related QTLs and QTL-by-environment interactions (QEIs) have been used in SCN-resistant breeding. Methods: In this study, a compressed variance component mixed model, 3VmrMLM, in genome-wide association studies was used to detect QTLs and QEIs for resistance to SCN HG Type 0 and HG Type 1.2.3.5.7 in 156 different soybean cultivars materials. Results and discussion: The results showed that 53 QTLs were detected in single environment analysis; 36 QTLs and 9 QEIs were detected in multi-environment analysis. Based on the statistical screening of the obtained QTLs, we obtained 10 novel QTLs and one QEI which were different from the previous studies. Based on previous studies, we identified 101 known genes around the significant/suggested QTLs and QEIs. Furthermore, used the transcriptome data of SCN-resistant (Dongnong L-10) and SCN-susceptible (Suinong 14) cultivars, 10 candidate genes related to SCN resistance were identified and verified by Quantitative real time polymerase chain reaction (qRT-PCR) analysis. Haplotype difference analysis showed that Glyma.03G005600 was associated with SCN HG Type 0 and HG Type 1.2.3.5.7 resistance and had a haplotype beneficial to multi-SCN-race resistance. These results provide a new idea for accelerating SCN disease resistance breeding.

Genome-wide association analysis of resistance to frogeye leaf spot China race 7 in soybean based on high-throughput sequencing.

KEY MESSAGE: FLS is a disease that causes severe yield reduction in soybean. In this study, four genes (Glyma.16G176800, Glyma.16G177300, Glyma.16G177400 and Glyma.16G182300) were tentatively confirmed to play an important role in the resistance of soybean to FLS race 7. Frogeye leaf spot (FLS) causes severe yield loss in soybean and has been found in several countries worldwide. Therefore, it is necessary to select and utilize FLS-resistant varieties for the management of FLS. In the present study, 335 representative soybean materials were assessed for partial resistance to FLS race 7. Quantitative trait nucleotide (QTN) and FLS race 7 candidate genes were identified using genome-wide association analysis (GWAS) based on a site-specific amplified fragment sequencing (SLAF-seq) approach. A total of 23,156 single-nucleotide polymorphisms (SNPs) were used to evaluate the level of linkage disequilibrium with a minor allele frequency ≥ 5 and deletion data < 3%. These SNPs covered about 947.01 MBP, nearly 86.09% of the entire soybean genome. In addition, a compressed mixed linear model was utilized to identify association signals for partial resistance to FLS race 7. A total of 15 QTNs associated with resistance were found to be novel for FLS race 7 resistance. A total of 217 candidate genes located in the 200-kb genomic region of these peak SNPs were identified. Based on gene association analysis, qRT-PCR, haplotype analysis and virus-induced gene silencing (VIGS) systems were used to further verify candidate genes Glyma.16G176800, Glyma.16G177300, Glyma.16G177400 and Glyma.16G182300. This indicates that these four candidate genes may participate in FLS race 7 resistance responses.

Correction: Regioselective O-alkylation of 2-pyridones by TfOH-catalyzed carbenoid insertion.

Correction for 'Regioselective O-alkylation of 2-pyridones by TfOH-catalyzed carbenoid insertion' by Zhewei Yan et al., Chem. Commun., 2023, 59, 106-109, https://doi.org/10.1039/d2cc05676c.

Regioselective O-alkylation of 2-pyridones by TfOH-catalyzed carbenoid insertion.

Selective alkylation of 2-pyridone could solve a challenge in chemistry and streamline the synthesis of important molecules. Here we report the regioselective O-alkylation of 2-pyridones by TfOH-catalyzed carbenoid insertion. In the catalytic system, alkylation of 2-pyridone was achieved with unprecedented regioselectiviy (>99 : 1). This protocol is characterized by mild reaction conditions, metal-free, and simplicity. Moreover, this method provides the desired products in good yield and demonstrates a broad substrate scope in this transformation.

Detoxification mechanism of vinegar-processed Kansui revealed by systematic phytochemical analysis using ultrahigh-performance liquid chromatography diode array detection tandem mass spectrometry, ultrahigh-performance liquid chromatography high-resolution mass spectrometry and in silico drug target identification.

RATIONALE: The dried roots of Euphorbia kansui L., known as Kansui, are used to treat ascites and edema in traditional Chinese medicine. However, the toxicity of this herb has seriously restricted its clinical application. A unique vinegar-processing method has been used to reduce its toxicity since the time of ancient China. However, the detoxification mechanism underlying such vinegar processing has not been fully revealed. To find the answer, the process-induced changes in components should be carefully investigated. METHODS: We performed a systematic analysis of chemical components in raw and vinegar-processed Kansui using ultrahigh-performance liquid chromatography (UHPLC) diode array detection tandem mass spectrometry and UHPLC high-resolution mass spectrometry. Thirty-one chemical components in raw and vinegar-processed Kansui were found, the chemical structures of 28 components among them were proposed and the process-induced changes in components were then investigated. RESULTS: A comprehensive conclusion about the process-induced chemical change was drawn. It was found that jatrophane-type diterpenoids decreased markedly after vinegar processing, while ingenane-type diterpenoids were retained during vinegar processing. In silico drug target identification gave hints that jatrophane-type diterpenoids, which decreased markedly during vinegar processing, may have more intense toxicity involving cholinesterase and mitogen-activated protein kinases, while ingenane-type diterpenoids, which were retained during vinegar processing, may have a more intense therapeutic effect involving carbonic anhydrase. CONCLUSIONS: The possible detoxification mechanism of vinegar-processed Kansui is presented. The research has significance for the therapeutic/toxic chemical basis of Kansui. Also, it has significance for drug discovery from terpenoids within the herb.

TfOH-catalyzed regioselective N2-alkylation of indazoles with diazo compounds.

Selective alkylation of indazoles is still a highly challenging topic in chemistry and the synthesis of important molecules. Herein, a novel highly selective N2-alkylation of indazoles with diazo compounds is described in the presence of TfOH. Unlike the traditional metal- and base-catalysed version, this protocol highlights the regioselectivity of alkylation of indazoles and a metal-free catalysis system, affording N2-alkylated products in good to excellent yields with high regioselectivity (N2/N1 up to 100/0) and excellent functional group tolerance. Furthermore, a gram scale synthesis was conducted successfully to give rise to the corresponding products. Mechanistic studies through control experiments provide plausible mechanistic proposals.

CircRNA ACAP2 induces myocardial apoptosis after myocardial infarction by sponging miR-29.

BACKGROUND: The aim of this study was to investigate the effect of circular RNA circ ACAP2 on apoptotic phenotype of rat cardiomyocytes and its molecular mechanism. METHODS: Left anterior descending ligation was used to establish a rat myocardial infarction (MI) model, and real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of circ ACAP2 in apoptotic rat cardiomyocytes. The stability of circ ACAP2 was tested by actinomycin D and RNase R. H9C2 cells were infected by recombinant circ ACAP2 adenovirus (rAd-circ ACAP2), and the expression of apoptotic related genes Bax and BCL-2 in H9C2 was detected. Double luciferase reporter gene experiment, RNA antisense purification experiment and RNA Pull-Down experiments verified the binding effect of circ ACAP2 and miR-29. RESULTS: RT-qPCR results showed that the expression of circ ACAP2 was increased in cardiomyocytes of MI rats. Actinomycin D and RNase R experiment confirmed that circ ACAP2 had better stability and resistance to RNase R degradation than its host gene ACAP2 mRNA. Overexpression of circ ACAP2 promotes apoptosis. The double luciferase reporter gene assay, RNA antisense purification assay and RNA Pulldown assay consistently confirmed the specific binding effect between circ ACAP2 and miR-29, and circ ACAP2 promoted the apoptotic phenotype in rats. CONCLUSIONS: The expression of circ ACAP2 increased in cardiomyocytes after MI and promoted apoptosis by binding to miR-29.

Quality control and product differentiation of LMWHs marketed in China using 1H NMR spectroscopy and chemometric tools.

Low molecular weight heparins (LMWHs) are heterogeneous mixtures of glycosaminoglycan chains composed of mixture of different lengths and substitution patterns. Structural characterization and quality control of LMWHs have always been challenging. The Chinese drug regulatory authorities have been committed to improve the supervision standards of LMWHs to better regulate the quality and safety of LMWHs in current Chinese market. In the present paper, 80 batches of three types LMWHs (dalteparin, enoxaparin and naldroparin) marketed in China from different manufacturers were studied by 1H NMR experiments and chemometric analysis. The method can be used not only to monitor impurities and contaminants, but also to check the batch-to-batch consistency of each manufacture. Moreover, for the biosimilar LMWHs from different manufactures, they can be differentiated and clustered according to their slightly different structural compositions originated from production process. By using this method, the quality and safety of LMWHs marketed in China were initially assessed.

Weighted gene co-expression network analysis identifies genes related to HG Type 0 resistance and verification of hub gene GmHg1.

Introduction: The soybean cyst nematode (SCN) is a major disease in soybean production thatseriously affects soybean yield. At present, there are no studies on weighted geneco-expression network analysis (WGCNA) related to SCN resistance. Methods: Here, transcriptome data from 36 soybean roots under SCN HG Type 0 (race 3) stresswere used in WGCNA to identify significant modules. Results and Discussion: A total of 10,000 differentially expressed genes and 21 modules were identified, of which the module most related to SCN was turquoise. In addition, the hub gene GmHg1 with high connectivity was selected, and its function was verified. GmHg1 encodes serine/threonine protein kinase (PK), and the expression of GmHg1 in SCN-resistant cultivars ('Dongnong L-204') and SCN-susceptible cultivars ('Heinong 37') increased significantly after HG Type 0 stress. Soybean plants transformed with GmHg1-OX had significantly increased SCN resistance. In contrast, the GmHg1-RNAi transgenic soybean plants significantly reduced SCN resistance. In transgenic materials, the expression patterns of 11 genes with the same expression trend as the GmHg1 gene in the 'turquoise module' were analyzed. Analysis showed that 11genes were co-expressed with GmHg1, which may be involved in the process of soybean resistance to SCN. Our work provides a new direction for studying the Molecular mechanism of soybean resistance to SCN.

Identification of glutathione transferase gene associated with partial resistance to Sclerotinia stem rot of soybean using genome-wide association and linkage mapping.

KEY MESSAGE: Association and linkage mapping techniques were used to identify and verify single nucleotide polymorphisms (SNPs) associated with Sclerotinia sclerotiorum resistance. A novel resistant gene, GmGST , was cloned and shown to be involved in soybean resistance to SSR. Sclerotinia stem rot (SSR), caused by the fungus Sclerotinia sclerotiorum, is one of the most devastating diseases in soybean (Glycine max (Linn.) Merr.) However, the genetic architecture underlying soybean resistance to SSR is poorly understood, despite several mapping and gene mining studies. In the present study, the identification of quantitative trait loci (QTLs) involved in the resistance to S. sclerotiorum was conducted in two segregating populations: an association population that consisted of 261 diverse soybean germplasms, and the MH population, derived from a cross between a partially resistant cultivar (Maple arrow) and a susceptible cultivar (Hefeng25). Three and five genomic regions affecting resistance were detected by genome-wide association study to control the lesion length of stems (LLS) and the death rate of seedling (DRS), respectively. Four QTLs were detected to underlie LLS, and one QTL controlled DRS after SSR infection. A major locus on chromosome (Chr.) 13 (qDRS13-1), which affected both DRS and LLS, was detected in both the natural population and the MH population. GmGST, encoding a glutathione S-transferase, was cloned as a candidate gene in qDRS13-1. GmGST was upregulated by the induction of the partially resistant cultivar Maple arrow. Transgenic experiments showed that the overexpression of GmGST in soybean increased resistance to S. sclerotiorum and the content of soluble pigment in stems of soybean. The results increase our understanding of the genetic architecture of soybean resistance to SSR and provide a framework for the future marker-assisted breeding of resistant soybean cultivars.

Diluted-CdS Quantum Dot-Assisted SnO2 Electron Transport Layer with Excellent Conductivity and Suitable Band Alignment for High-Performance Planar Perovskite Solar Cells.

An electron transport layer (ETL) with excellent conductivity and suitable band alignment plays a key role in accelerating charge extraction and transfer for achieving highly efficient planar perovskite solar cells (PSCs). Herein, a novel diluted-cadmium sulfide quantum dot (CdS QD)-assisted SnO2 ETL has been developed with a low-temperature fabrication process. The slight addition of CdS QDs first enhances the crystallinity and flatness of SnO2 ETLs so that it provides a promising workstation to obtain high-quality perovskite absorption layers. It also amazingly increases the conductivity of the SnO2 ETL by an order of magnitude and regulates the energy level matching between the SnO2 ETL and perovskite. These outstanding properties greatly accelerate the charge extraction and transfer. Thus, the MAPbI3-based PSCs with such a diluted-CdSQD-assisted SnO2 ETL achieve a maximum power conversion efficiency of 20.78% and obtain a better stability of devices in air. These findings testify the importance and potential of semiconductor QD modification on ETLs, which may pave the way for developing such composite ETLs for further enhancing photovoltaic performance of planar PSCs.

NMR-based screening for natural product subfraction to precisely identify ligand of target protein.

INTRODUCTION: The inherent diversity of natural product extracts has not only made their value for biological activity attractive, but has also presented significant challenges for separation and detection techniques to enable rapid characterisation of the biologically active component present in the complicated mixture. OBJECTIVE: Nuclear magnetic resonance (NMR) is routinely valued for its ability to shed light on molecular structure, when NMR is used as a promising tool in drug screening, it can detect and quantify molecular interactions, and at the same time provide detailed structural information with atomic level resolution. Here, we introduced an accurate and efficient strategy for discovering ligands from natural product extracts, by taking the advantage of NMR-based drug screening. METHODOLOGY: The characteristic pre-purified subfraction libraries were brought into screening, and combinatorial ligand-observed NMR interaction detection experiments were performed, once hits were found from one subfraction, the repository of the subfraction would be subject to separation and preparation, and the structure of the hits would be easily identified. RESULTS: Screening procedure of Radix Polygoni Multiflori water extract against human serum albumin (HSA) was used as an example, to discuss and verify the detailed methodology. Furthermore, human fatty acid binding protein 4 (FABP4 ) was presented as an example target protein, to illustrate the utility of this method for discovering biologically active component. CONCLUSIONS: It is proved that suitable subfraction library and well-combined ligand-detected NMR experiments will make the screening streamline more accurate and efficient. NMR is a promising tool to integrate natural product extracts into modern drug screening.

Polyphenols as reactive carbonyl species scavengers-The solution to the current puzzle of polyphenols' health effects.

Evidence from epidemiological analysis confirmed the protective effects of polyphenol-rich foods or beverages from certain chronic diseases, however, a direct antioxidant effect is not fully feasible when considering for the real in vivo behavior of polyphenols. Polyphenols have a limited bioavailability and only low concentrations are present in the systemic circulation compared with other endogenous and exogenous antioxidants, besides, how polyphenol can enter tissue (especially brain) and cells were not answered yet. There is investigation showed that reactive carbonyl species (RCS), which accumulated in circulatory system and tissue, also plays a significant role in the etiology and progression of certain chronic diseases. In the effort of searching for nontoxic trapping agents of RCS from dietary sources, some natural polyphenols have been found to have reactivity with RCS, It should be realized that polyphenols are versatile bioactive rather than mere antioxidants. We present here the hypothesis that polyphenols acting as RCS scavengers maybe the supplementary and reasonable mechanism for the puzzle of polyphenols' health effects.

Inhibition evaluation of gas inhibitors in micron-sized aluminum dust explosion.

The inhibition effects of gas inhibitors (nitrogen, carbon dioxide, and heptafluoropropane) on aluminum dust explosion were investigated experimentally and numerically. The results showed that as the inhibition volume fraction increased, the flame propagation characteristics parameters and explosion severity parameters were inhibited by inert gases accordingly. The inhibition performance of carbon dioxide was superior to that of nitrogen, and the minimum inhibition volume fractions of nitrogen and carbon dioxide were determined. XRD results indicated that the crystal form of major condensed product of aluminum dust explosion using two kinds of inert gas as inhibitors was different due to the distinct inhibition effect. Moreover, the XPS analysis revealed that the nitrogen oxide of aluminum adsorbed on the surface of aluminum particles blocked gasification process of aluminum particles. To explore the inhibition mechanism microscopically, a kinetic model concerning gas phase combustion was established. The above discussion indicated that the inhibition effect was the combination of multiple factors. In addition, due to the strong reactions between aluminum particles and heptafluoropropane, it cannot be regarded as gas inhibitor in aluminum dust explosion.

A NMR-based drug screening strategy for discovering active substances from herbal medicines: Using Radix Polygoni Multiflori as example.

ETHNOPHARMACOLOGICAL RELEVANCE: Herbal medicines have always been important sources for new drugs. And developing new drugs from traditional herbal medicine is currently still an effective way. However, screening for active substances from herbal medicines extracts has ever been a challenging topic, due to their intrinsic complexity. The herb Radix Polygoni Multiflori has been used as a tonic and an antiaging herb in Traditional Chinese Medicine. In clinical studies, the extract of Radix Polygoni Multiflori can improve hypercholesterolemia, atherosclerotic, diabetes and other diseases commonly associated with glycolipid metabolism, however, the molecular mechanisms of these actions are unknown. AIM OF THE STUDY: We devised a NMR-based drug screening strategy for discovering active substances from herbal medicines, using Radix Polygoni Multiflori as example to address such challenging topic, meanwhile, to explore molecular target of Radix Polygoni Multiflori's glycolipid metabolism benefit. MATERIALS AND METHODS: Herbal medicines extracts were subjected to moderate separation to generate libraries of pre-purified subfractions, target protein was then added to each subfraction, and ligand-observed NMR experiments (line-broadening experiment, chemical shift perturbations measurements and saturation transfer difference spectrum) were performed, active substances identification and structural optimization were then accomplished using signals provided by ligand-observed NMR interaction detection and HPLC-SPE-NMR. The strategy was demonstrated by discovering an active component from extract of herb Radix Polygoni Multiflori, using human fatty acid binding protein 4 (FABP4) as target protein. RESULTS: 2,4-dihydroxy-6-[(1E)-2-(4-hydroxyphenyl)ethenyl]phenyl-ß-D-glucopyranoside(TSG), the hit from one subfraction, has obvious interaction with target protein FABP4, due to FABP4 is a potential therapeutic target for metabolic diseases such as diabetes and atherosclerosis, the screening result will give clue to the active component and molecular target of Radix Polygoni Multiflori's glycolipid metabolism benefit. Besides, interaction information at atom level offered by ligand-observed NMR experiment would be valuable in the further stage of lead optimization. CONCLUSIONS: The devised NMR-based drug screening strategy can discover active substances from herbal medicines efficiently and precisely, meanwhile, can shed light on molecular mechanism of traditional usage of the herb.

Suppression mechanism of Al dust explosion by melamine polyphosphate and melamine cyanurate.

The suppression mechanism of melamine polyphosphate (MPP) and melamine cyanurate (MCA) for Al dust explosions is investigated experimentally and computationally. Results show that depending on the concentration of suppressants, the addition of MCA and MPP promotes or suppresses Al dust explosion. For high additive concentration, large agglomerated residues are generated, and condensed phase residues may contain Al particles, MCA or MPP. The chemical composition of condensed phase residues of Al/MCA mixture explosion is mainly Al2O3 and the high boiling products of MEL decomposition (mainly C‒ and N‒containing species). The explosion residues of Al/MPP mixture are composed of Al2O3, high boiling products of MEL decomposition and condensed phosphates. To understand the reasons for pressure enhancement and explosion suppression, a kinetic model considering both gas and surface chemistry of Al particles combustion is developed. The simulations indicate that the high pressure rise is caused by the extra heat released from the exothermic reactions of suppressants and the increase of gas phase products. MPP and MCA can suppress surface reaction by decreasing Al(L) site fraction. Additionally, the vaporization rate of Al particles and the diffusion rate of oxidizers close to the droplet surface are reduced by MPP and MCA addition.

Structure characterization and optical properties investigation of the four main components of the classical phenazinium dye Safranin O.

Safranin O is an important and classical phenazinium dye; since the 19th century, it has been extensively used in the academic field as a spectroscopic probe and indicator. Surprisingly, we found that this long-used reagent is without exception a mixture. In this study, the four main components in a Safranin O sample were prepared, and their chemical structures were elucidated for the first time. Optical property investigations showed that the components had somewhat different absorbance properties and markedly different fluorescence properties, and their structure-optical activity relationships were also discussed. It could be inferred that the variation of each component in the content would unavoidably result in inconsistent optical data when using this Safranin O reagent as a spectroscopic probe or indicator. Considering the accurate transfer of measurement results between laboratories, high-purity Safranin O is in urgent demand in the academic field.

Flame suppression mechanism of aluminum dust cloud by melamine cyanurate and melamine polyphosphate.

The suppression effect of melamine cyanurate (MCA) and melamine polyphosphate (MPP) on the flame propagation of aluminum dust were studied experimentally. The results indicated that the concentration of MPP required to supress the aluminum dust explosion was lower than MCA. As the concentration of suppressant increased, the acceleration and the maximum flame speed extremely decreased, and the flame morphology became isolated spot flames. The MPP addition exerted a stronger suppression effect on the temperature of aluminum flame compared to MCA addition. Meanwhile, the mechanism of flame suppression was further investigated. Decomposition of MCA and MPP particles could absorb the heat released from the flame front. Scanning electron microscopy demonstrated that the gas phase reaction of aluminum particles was suppressed by MCA and MPP, resulting in a larger particle size of the explosion products. XRD results indicated that MCA and MPP did not react with aluminum. Gaseous products of suppressant decomposition altered flame chemistry by radically recombining O atom and reducing AlO, which resulted in less amount of heat release, lower flame speed and lower flame temperature.