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The electromagnetic mill (EMM) promoted mechanochemical solvent-free palladium-catalyzed borylation of aryl bromides using low palladium catalyst loading (0.05-0.5 mol %) was realized. This protocol exhibits many advantages, such as broad substrate scope, good functional group tolerance, short reaction times, no additional heating, and practical gram-scale synthesis. This EMM system not only showed excellent prospects for industrial application but also unlocked broad areas of solvent-free solid-state metal-catalyzed syntheses.

We herein report the first visible-light-induced hydromono- and difluoroalkylations of alkenes with inexpensive and easily accessible α-fluoro carboxylic acids. This metal-free protocol exhibits mild conditions, high efficiency, and excellent functional-group tolerance, providing a straightforward approach to mono- and difluoroalkylated alkanes. Moreover, the fluorine effect on the hydrofluoroalkylation reaction is discussed in detail.

Recently, PLMs (pre-trained language models) and syntax-based GCNs (graph convolutional neural networks) have been widely and deeply applied in aspect-based sentiment analysis, effectively promoting the development of this field. However, these methods rarely make use of external knowledge, such as knowledge of high-quality sentiment lexicons, which can be a powerful complement to these methods if the prior knowledge can be effectively used. In this paper, to use external knowledge, we propose a Knowledge Enhanced Graph Convolutional Network for aspect-based sentiment analysis (KEGCN). KEGCN automatically calculates the sentiment eigenvalue of each word and extracts strong sentiment words, then retrains the PLM representations of strong sentiment words to integrate external sentiment knowledge into our model. Experimental results on several benchmark datasets demonstrate the effectiveness of our model, which outperforms previous baseline models in terms of both accuracy and macro-F1.

A mild and efficient method for direct C-H monofluoroalkylation of heteroarenes with easily accessible and inexpensive α-fluorocarboxylic acids has been developed. This silver-catalyzed reaction affords mono- and bis-monofluoroalkylated heteroarenes in good yields under mild conditions, and the solvent effect on the monofluoroalkylation reaction is discussed in detail.

In regiodivergent arylamination/aryloxygenation of allenamides, use of Cy2NMe caused 2,1-arylamination and the corresponding alkenes were formed with excellent Z configuration. Whereas, utilizing Ag2CO3 caused 2,3-aryloxygenation via an unexpected CO2 insertion from Ag2CO3.

An efficient and convenient three-component phosphorylation-acylation of 2-vinyl pyridines under mild conditions has been developed. This protocol provides a sustainable and practical strategy for synthesis of novel α,β-acylphosphinoyl compounds, and...

Intrusion detection is a fuzzy classification problem. Intrusion detection can detect the attack behaviors of hackers in advance. For generating a visualizing architecture for identifying intrusions, this study proposes an approach that combines ANFIS (Adaptive Network-based Fuzzy Inference System), DT (Decision Tree), and K-means clustering algorithm for visualizing the deep pattern of intrusion detection. The ANFIS generates complex and fuzzy combinations of selected attributes. To reduce the rules generation of ANFIS, Pearson Correlation analysis is used to select attributes that highly relate to the target. Meanwhile, standard deviation analysis and a proposed adaptive K-means algorithm are used for determining the interval division of selected attributes. Then, the CART (classification and regression tree) is used to identify the deep mode in generated rules and selected attributes. The architecture of the proposed algorithm is a hybrid visualizing approach. The architecture can identify deep and hybrid features in intrusion detection. The proposed algorithm was trained, validated, and tested on the NSL-KDD dataset. Using 22 attributes that highly relate to the target, the performance of the proposed method achieved a 99.86% detection rate and 0.14% false alarm rate, which is better than many classifiers. Besides, the visualizing model can help us visually identify the complex pattern of intrusions and analyze the pattern of various intrusions.

A Pd/Et

A palladium/norbornene cooperative catalyzed selective C–H bond amination of aryl iodides was explored, providing an efficient tool for constructing benzocyclic molecules. When ortho-substituted io...

Aggregation-induced/enhanced emission (AIE/AEE) materials have aroused wide attention for their potential applications in optoelectronic devices and biosensors. In this paper, the working mechanism of a new kind of AEE-active luminogen, tetraphenylpyrazine (TPP) and its derivatives, is studied by first-principles calculations contrasting their pyrazine core with an inherent n → π* transition. Our results indicate that the attachment of phenyl rings to the pyrazine core can change the n → π* transition component to π → π* via the electronic conjugated effect and evoke restriction of intramolecular motion (RIM) that is responsible for the AEE characteristics. Decoration of the TPP peripheries with electron-withdrawing CF3 groups hardly affects the electronic transition properties and barely improves the solid-state luminescence. Substitution of the peripheral phenyls with electron-donating OCH3 groups thoroughly opens up the radiative channel and greatly enhances the emission quantum efficiency. Moreover, CF3 and OCH3 substituents can respectively generate extra CH⋯F/F⋯F/CF⋯π and CH⋯O interactions, which could promote RIM and slow down the non-radiative decay process. The experimental results confirm the theoretical predictions well. The above modulation guideline can be summarized from a molecular picture: the phenyl attachment reduces the n → π* transition component and evokes RIM, while the substituent decoration imparts altered electronic conjugation and promotes RIM. Our work not only offers valuable insight into AEE phenomena, but also provides a strategy for the rational design of efficient heterocycle-containing emitters.

Herein, a nickel-catalyzed two-component reductive arylcyanation of aryl (pseudo)halide tethered alkenes using benzyl thiocyanate as the cyanide source via C–S bond activation is developed. Using this protocol, a wide scope of 3,3-disubstituted oxindoles bearing all-carbon quaternary stereocenters are accessible in moderate to excellent yields. The preliminary mechanistic investigations reveal that a Ni(I)/Ni(III) process might be involved in the mechanism.

Herein reported is a nickel-catalyzed reductive aryl thiocarbonylation of alkene via thioester group transfer strategy by using simple and readily available thioesters. In contrast to traditional activation of weaker C(acyl)-S bond, the C(acyl)-C bond of thioester was selectively cleaved to enable this reaction under mild conditions. Furthermore, this approach features operational simplicity and broad substrate scope, providing a complementary and practical route for thioester synthesis without requiring toxic thiol or CO gas.

A novel ortho-arene C–H acylation of aryl iodides catalyzed by the palladium/norbornene cooperative system by employing triazine esters has been developed, leading to the synthesis of polysubstituted aryl ketones. This ortho-acylation even proceeds smoothly in water. Preliminary mechanistic experiments indicate that the strong electron-withdrawing ability and coordination chemistry of triazine play crucial roles in this transformation.

Environmental protection is the core of sustainable economic development, and environmental policy plays a key role in achieving protection goals. Therefore, it is extremely crucial to evaluate the effectiveness of environmental policies. Existing studies mainly focus on the average impact of environmental policies on environmental pollution but ignore their dynamic impact, which is prone to misestimate the effect of environmental policies. To make up for the deficiency, a semiparametric additive panel data model is used to explore the dynamic impact of China’s sewage charging policy on environmental performance at each level of the levy. The results show that the relationship between sewage charge level and environmental degeneration is an “M-shaped” pattern, indicating that the current sewage charge policy is not absolutely effective. Moreover, the results also reveal an “N-shaped” linkage between economic growth and environmental pollution, indicating that economic development is not sustainable. Moreover, the factors of energy consumption, population growth, and industrialization contribute to increasing environmental degeneration. Although technological development has a positive impact on environmental performance, its impact is insignificant. This study could provide new evidence for strengthening environmental regulatory reform and promoting green economic development.

A sandwich-type electrochemical immunosensor was fabricated for the quantitation of alpha fetoprotein (AFP). To this end, the Au@Pt dendritic nanorods loaded with amino functionalized molybdenum selenide nanosheets (Au@Pt 41 DNRs/NH2-MoSe2 NSs) with enhanced peroxidase-like properties were selected as the secondary antibody label (Ab2) to achieve signal amplification. The as-obtained Au@Pt DNRs/NH2-MoSe2 NSs exhibited better catalytic activity toward hydrogen peroxide reduction and offered rich anchors for bioconjugation. Meanwhile, gold nanoparticles anchored on an amino functionalized graphene (Au NPs/NH2-GS) composite with admirable conductivity and biocompatibility was used as the matrix material to improve sensitivity. Under optimal conditions, amperometric current responses had a good linear relationship with the logarithm values of AFP concentration in the range 10 fg mL–1 to 200 ng mL–1 with a detection limit of 3.3 fg mL–1 (S/N = 3). Additionally, the immunosensor had excellent reproducibility, selectivity, and stability, which indicated superior performance for AFP detection compared with previous reports. The satisfactory results of human serum samples analysis showed that the designed immunosensor has potential applicability for the sensitive detection of other tumor markers.

A novel palladium-catalyzed regiocontrollable hydroarylation reaction of allenamides with B2pin2/H2O has been disclosed. H2O as an ideal hydrogen source was activated by B2pin2 to furnish allylamines or enamines with a broad functional group tolerance. The regioselectivity for both of the two products was up to 99 : 1 for most of the examples, which was achieved by adjusting the addition order of the catalyst and iodobenzene derivatives. The tentative investigation of the mechanism proved the reaction to be a non-radical process and the deuterium-labeled experiments indicated that the hydrogen was from H2O.

1,1-Difluoroethylated aromatics are of great importance in medicinal chemistry and related fields. 1,1-Difluoroethyl chloride (CH3CF2Cl), a cheap and abundant industrial raw material, is viewed as an ideal 1,1-difluoroethylating reagent, but the direct introduction of the difluoroethyl (CF2CH3) group onto aromatic rings using CH3CF2Cl has not been successfully accomplished. Herein, we disclose a nickel-catalyzed 1,1-difluoroethylation of arylboronic acids with CH3CF2Cl for the synthesis of (1,1-difluoroethyl)arenes.

The introduction of fluorine atoms into an organic molecule has become an important research field since fluorinated compounds play crucial roles in life science and materials chemistry. Among various fluorinated moieties, the difluoroethyl group (CF2CH3) mimics the steric and electronic features of a methoxy group, and this modification can often bring about many beneficial effects to the target molecules. This feature article summarizes the presently known methods for the synthesis of (1,1-difluoroethyl)arenes, including nucleophilic, electrophilic, and free radical fluorination or 1,1-difluoroethylation reactions.

A palladium/norbornene cooperative catalyzed selective C-H bond amination of aryl iodides was explored, providing an efficient tool for constructing benzocyclic molecules. When

The hepatitis B virus (HBV) can cause chronic hepatitis and hepatocellular carcinoma. Hepatitis B surface antigen (HBs-Ag) and Hepatitis B e-antigen (HBe-Ag) are key markers for the diagnosis of HBV. In this study, electrodeposited gold was used as a sensing platform. Three-dimensional (3D) SnO2-loaded graphene sheets functionalized by Thionine (Thi) and ferrocene (Fc) and hybridized by sea urchin–like bimetallic nanoparticles (GS-SnO2-BMNPs) were used as redox probes for labeling antibodies to fabricate sandwich-type immunosensors for the simultaneous determination of HBs-Ag and HBe-Ag. The bimetallic nanoparticles, gold hybrid platinum nanoparticles (Au@Pt) and l-cysteine-connected gold-silver nanoparticles (Ag-cys-Au), have large electroactive surface areas. They were prepared by an efficient and economical method. Additionally, the sea urchin morphology accelerates spatial utilization, thus increasing the number of combination sites. Therefore, the immune probe can load a mass of signal source molecules (Thi and Fc). Furthermore, GS-SnO2-BMNPs (GS-SnO2-Au@Pt and GS-SnO2-Ag-cys-Au) with excellent electrical conductivity and bimetallic synergy can enhance the square wave voltammetry (SWV) signal. SWV was used to record the electrochemical signal by scanning the potential from − 0.6 to 0.6 V (vs. SCE). The signal peaks resulted from the reduction reaction of Thi and Fc, and two signal peaks were completely separate. The peak position and current intensity reflect the identity and level of the corresponding antigens. Therefore, the simultaneous detection of two viral biomarkers was achieved by the proposed immunosensor. The fabricated immunosensor showed a linear concentration range for HBs-Ag (0.01–100 ng·mL−1) and HBe-Ag (0.01–100 ng·mL−1), with detection limits for HBs-Ag and HBe-Ag of 4.67 pg·mL−1 and 4.68 pg·mL−1, respectively. The RSD of HBs-Ag ranged between 2.0 and 4.4%and the recovery was in the range 98.7 to 99.4%. For HBe-Ag the RSD was between 2.6 and 3.3% andrecoveries in the range 99.2 to 100.5% were obtained.

The hepatitis B virus (HBV) can cause chronic hepatitis and hepatocellular carcinoma. Hepatitis B surface antigen (HBs-Ag) and Hepatitis B e-antigen (HBe-Ag) are key markers for the diagnosis of HBV. In this study, electrodeposited gold was used as a sensing platform. Three-dimensional (3D) SnO

As a specific biomarker, neuron-specific enolase (NSE) is an essential clinical indicator for diagnosing small cell lung cancer. In this paper, a sandwich-type electrochemical immunosensor was designed for the quantitative detection of NSE. AuPt nanoblock spherical nanoarchitectonics (AuPt NSNs), a bimetallic nanoparticle with a rugged morphology, were utilized as the substrate, which could enhance the electronic conduction and increase the immobilization capacity of the primary antibody (Ab

A sandwich-type electrochemical immunosensor was designed utilizing ferrocene-functionalized cuprous oxide superparticles (Au/Fc@CuxO SPs) as the signal label and graphene supported by hollow carbon balls (HCNs-GR) as the substrate. The CuxO SPs possess a superparticle structure with synergistic properties of isotropy and promising catalytic activity. Ferrocene (Fc) was deposited on the CuxO SPs to act as the electronic transmission medium. The Au/Fc@CuxO SPs played a pivotal role in improving the sensitivity of the immunosensor. The graphene supported by hollow carbon balls (HCNs-GR) was used to modify the electrode surface. The embedding of hollow carbon nanospheres (HCNs) reduced the decrease of the effective surface area caused by the stacking of graphene nanotubes. Meanwhile, the load of carbon balls further increases the surface area of graphene, enabled HCNs-GR to immobilize antibodies more effectively, improved the sensitivity of the immunosensor. The proposed immunosensor showed a linear range from 500 fg/mL to 100 ng/mL, with the detection limit to 25.7 fg/mL.

In existing evacuation methods, the large number of pedestrians and the complex environment will affect the efficiency of evacuation. Therefore, we propose a hierarchical evacuation method based on multi-agent deep reinforcement learning (MADRL) to solve the above problem. First, we use a two-level evacuation mechanism to guide evacuations, the crowd is divided into leaders and followers. Second, in the upper level, leaders perform path planning to guide the evacuation. To obtain the best evacuation path, we propose the efficient multi-agent deep deterministic policy gradient (E-MADDPG) algorithm for crowd-evacuation path planning. E-MADDPG algorithm combines learning curves to improve the fixed experience pool of MADDPG algorithm and uses high-priority experience playback strategy to improve the sampling strategy. The improvement increases the learning efficiency of the algorithm. Meanwhile we extract pedestrian motion trajectories from real motion videos to reduce the state space of algorithm. Third, in the bottom layer, followers use the relative velocity obstacle (RVO) algorithm to avoid collisions and follow leaders to evacuate. Finally, experimental results illustrate that the E-MADDPG algorithm can improve path planning efficiency, while the proposed method can improve the efficiency of crowd evacuation.

The synthesis method of P(O)-S organophosphorus compounds by dehydrogenative coupling reaction of P(O)H compounds and aryl thiols was developed. The reaction was carried in the presence of a base and air, and exhibited good characters such as metal-free, mild reaction temperature, excellent substrate tolerance and with moderate to good yields. A plausible mechanism was proposed.

We novelly designed and synthesized a set of fluorinated diphenyl-diketopyrrolopyrrole (DPP) compounds by varying the position and amount of fluorine atom, and to the best of our knowledge, it is the first time a difluoromethyl group and perfluoroalkyl chains had been introduced into the DPP unit in good yields. We investigate the optical/electrochemical properties of all the compounds. Density functional theory (DFT) calculations were applied to explore orbital energy value of these compounds. The results demonstrated that the perfluorocarbon chains substituted DPPs with larger red-shift in both absorption and emission spectra and narrower bandgap.

Little attention has been paid to the stability and reactivity of the C–F bond under different conditions. In this study, the stability and reactivity of tri-, di-, and monofluoromethyl/methoxy/methylthio moiety groups on arenes under acidic or basic conditions are carefully investigated.

1,1-Difluoroethylated aromatics are of great importance in medicinal chemistry and related fields. 1,1-Difluoroethyl chloride (CH

A voltammetric sandwich immunoassay is described for the biomarker cardiac troponin I (cTnI). The gold nanocube-functionalized graphene oxide (AuNC/GO) is employed as a substrate to accelerate the electron transfer and to immobilize more primary antibodies. It also employs composite materials prepared from bimetallic gold/silver core-shell nanocubes and nitrogen and sulfur co-doped reduced graphene oxide as the signal amplifier. The introduction of N and S into GO enlarges the active surface and accelerates the electron transfer rate. Such unique characteristics render the material an effective support substrate to load more Au@AgNC and to immobilize an increasing number of second antibodies via Ag-N bonds. After specific binding with cTnI, the immunosensor was incubated in a labeled cTnI secondary antibody solution. The amperometric signal change is then measured at 0.34 V (vs. SCE) using o-phenylenediamine and hydrogen peroxide as an electrochemical probe. Response is linear in the concentration range from 100 fg∙mL−1 to 250 ng∙mL−1, and the detection limit is 33 fg∙mL−1.

A sandwich-type electrochemical immunosensor for detecting amyloid-beta protein was fabricated based on Au NP-functionalized reduced graphene oxide (Au@rGO) as an effective sensing platform and AuCu