The Buchwald‐Hartwig C‐N coupling reaction has found widespread applications in organic synthesis. Over the past two decades or so, many improved catalysts have been introduced, allowing various ...amines and aryl electrophiles to be readily used nowadays. However, there lacks a protocol that could be used to couple a wide range of chiral amines and aryl halides, without erosion of the enantiomeric excess (ee). Reported in this article is a method based on molecular Ni catalysis driven by light, which enables stereoretentive C‐N coupling of optically active amines, amino alcohols, and amino acid esters with aryl bromides, with no need for any external photosensitizer. The method is effective for a wide variety of coupling partners, including those bearing functional groups sensitive to bases and nucleophiles, thus providing a viable alternative to accessing synthetically important chiral N‐aryl amines, amino alcohols, and amino acids esters. Its viability is demonstrated by 92 examples with up to 99 % ee.
A stereoretentive C−N coupling of optically active amines and amino acid esters with aryl bromides is achieved by nickel catalysis under light irradiation, without the use of any external photosensitizers.
In a networked multiaxis motion control task, faults in any motor will cause the performance degradation of cooperative operation, which may considerably affect the whole network and the quality of ...products. The main objective of this article is to propose an improved observer-based fault-tolerant tracking control approach for industrial multiagent systems. First, a group of new distributed intermediate estimators is presented, where the design structure is modified to enhance the feasibility of the estimation scheme. It is shown that both of the nominal distributed intermediate estimator and the traditional extended state observer are special cases of the proposed estimator. Second, the estimation performance can be improved significantly via an online reinforcement learning estimation strategy, whose core is an adaptive switching mechanism integrated with a function block of source fault mode localization. Benefiting from satisfactory estimation results, good fault-tolerant tracking control performance can be guaranteed despite of multiple faults and disturbances. The application to a networked multiaxis motion control system demonstrates the effectiveness and superiority of the proposed method.
This review summarizes the AIE self-assembly gel research progresses on cyanostibene derivatives made in the past decade with an emphasis on the regulation and their applications in different fields.
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•The advances of AIE self-assembly gel based cyanostibene derivatives.•The design strategies and the regulation of self-assembly process of gel systems.•The diverse application of AIE self-assembly gel based cyanostibene derivatives.•The challenges and outlook in AIE self-assembly gel based cyanostibene derivatives.
Aggregation-induced emission (AIE) is attracting enormous attention due to the immense potential practical application of luminescent materials in the solid state. Cyanostilbene derivatives are a kind of desired AIE fluorophore with advantages of photostability and thermostability, distinguished fluorescence quantum yields and adjustable emission wavelengths. Cyanostilbene derivatives with AIE behaviour can be combined with self-assembly gels, to achieve advantages the complementary advantages of the two materials. In this review, we summarized the sate-of-the-art progress of supramolecular gel based on cyanostilbene derivatives, as well as their applications in the regulation of self-assembly process and emission behaviour, multifunctional sensor, photoresponsive materials, circularly polarized luminescence and biological fields. A brief summary and outlook on cyanostilbene-based supramolecular self-assembly materials are also included.
Feature selection is a crucial step in the development of a system for identifying emotions in speech. Recently, the interaction between features generated from the same audio source was rarely ...considered, which may produce redundant features and increase the computational costs. To solve this problem, feature selection method based on correlation analysis and Fisher is proposed, which can remove the redundant features that have close correlations with each other. To improve the recognition performance of the feature subset after proposal feature selection further, an emotion recognition method based on extreme learning machine (ELM) decision tree is proposed according to the confusion degree among different basic emotions. A framework of speech emotion recognition is proposed and the classification experiments based on proposed classification method by using Chinese speech database from institute of automation of Chinese academy of sciences (CASIA) are performed. And the experimental results show that the proposal achieved 89.6% recognition rate on average. By proposal, it would be fast and efficient to discriminate emotional states of different speakers from speech, and it would make it possible to realize the interaction between speaker-independent and computer/robot in the future.
Arginine methylation is an important posttranslational modification catalyzed by protein arginine methyltransferases (PRMTs). However, the role of PRMTs in colorectal cancer (CRC) progression is not ...well understood. Here we report that non-POU domain-containing octamer-binding protein (NONO) is overexpressed in CRC tissue and is a potential marker for poor prognosis in CRC patients. NONO silencing resulted in decreased proliferation, migration, and invasion of CRC cells, whereas overexpression had the opposite effect. In a xenograft model, tumors derived from NONO-deficient CRC cells were smaller than those derived from wild-type (WT) cells, and PRMT1 inhibition blocked CRC xenograft progression. A mass spectrometry analysis indicated that NONO is a substrate of PRMT1. R251 of NONO was asymmetrically dimethylated by PRMT1 in vitro and in vivo. Compared to NONO WT cells, NONO R251K mutant-expressing CRC cells showed reduced proliferation, migration, and invasion, and PRMT1 knockdown or pharmacological inhibition abrogated the malignant phenotype associated with NONO asymmetric dimethylation in both KRAS WT and mutant CRC cells. Compared to adjacent normal tissue, PRMT1 was highly expressed in the CRC zone in clinical specimens, which was correlated with poor overall survival in patients with locally advanced CRC. These results demonstrate that PRMT1-mediated methylation of NONO at R251 promotes CRC growth and metastasis, and suggest that PRMT1 inhibition may be an effective therapeutic strategy for CRC treatment regardless of KRAS mutation status.
Thrips are tiny insects from the order Thysanoptera (Hexapoda: Condylognatha), including many sap‐sucking pests that are causing increasing damage to crops worldwide. In contrast to their closest ...relatives of Hemiptera (Hexapoda: Condylognatha), including numerous sap‐sucking species, there are few genomic resources available for thrips. In this study, we assembled the first thrips genome at the chromosomal level from the melon thrips, Thrips palmi, a notorious pest in agriculture, using PacBio long‐read and Illumina short‐read sequences. The assembled genome was 237.85 Mb in size, with 1,324 contigs and a contig N50 of 567 kb. All contigs were assembled into 16 linkage groups assisted by the Hi‐C technique. In total, 16,333 protein‐coding genes were predicted, of which 88.13% were functionally annotated. Among sap‐sucking insects, polyphagous species (e.g., T. palmi and Bemisia tabaci) usually possess more detoxification genes than oligophagous species (e.g., Diaphorina citri). The polyphagous thrips genomes characterized so far have relatively more detoxification genes in the GST and CCE families than polyphagous aphids, but they have fewer UGTs. HSP genes, especially from the Hsp70s group, have expanded in thrips compared to other hemipterans. These differences point to different genetic mechanisms associated with detoxification and stress responses in these two groups of sap‐sucking insects. The expansion of these gene families may contribute to the rapid development of pesticide resistance in thrips, as supported by a transcriptome comparison of resistant and sensitive populations of T. palmi. The high‐quality genome developed here provides an invaluable resource for understanding the ecology, genetics, and evolution of thrips as well as their relatives more generally.
Adaptive evolution following colonization can affect the impact of invasive species. The fall webworm (FWW) invaded China 40 years ago through a single introduction event involving a severe ...bottleneck and subsequently diverged into two genetic groups. The well‐recorded invasion history of FWW, coupled with a clear pattern of genetic divergence, provides an opportunity to investigate whether there is any sign of adaptive evolution following the invasion. Based on genome‐wide SNPs, we identified genetically separated western and eastern groups of FWW and correlated spatial variation in SNPs with geographical and climatic factors. Geographical factors explained a similar proportion of the genetic variation across all populations compared with climatic factors. However, when the two population groups were analysed separately, environmental factors explained more variation than geographical factors. SNP outliers in populations of the western group had relatively stronger response to precipitation than temperature‐related variables. Functional annotation of SNP outliers identified genes associated with insect cuticle protein potentially related to desiccation adaptation in the western group and genes associated with lipase biosynthesis potentially related to temperature adaptation in the eastern group. Our study suggests that invasive species may maintain the evolutionary potential to adapt to heterogeneous environments despite a single invasion event. The molecular data suggest that quantitative trait comparisons across environments would be worthwhile.
Probiotics have been reported to reduce total cholesterol levels in vitro, but more evidence is needed to determine the clinical relevance of this activity. Chinese traditional fermented pickles ...are a good source of lactic acid bacteria. Therefore, pickle samples were collected for screening lactic acid bacteria based on their ability to survive stresses encountered during gastrointestinal passage and cholesterol reducing potency.
Seventy five lactic acid bacteria strains were isolated from 22 fermented pickles. From these bacteria, Lactobacillus plantarum E680, showed the highest acid (85.25%) and bile tolerance (80.79%). It was sensitive to five of the eight antibiotics tested, inhibited the growth of four pathogenic bacteria, and reduced the total cholesterol level by 66.84% in broth culture. In vivo testing using hypercholesterolemic mice fed high-fat emulsion, independent of food intake, found that L. plantarum E680 suppressed body weight gain and reduced total cholesterol and low-density lipoprotein cholesterol levels, with no effect on high-density lipoprotein cholesterol.
Chinese traditional fermented pickles are a good source for probiotics. L. plantarum E680, isolated from pickles, was acid and bile tolerant, sensitive to antibiotics, and reduced cholesterol levels both in vitro and in vivo. Based on these results, L. plantarum E680 may have potential as a novel probiotic for the development of cholesterol-lowering functional food.
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