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•The use of arylsulfonium salts as versatile arylation reagents is summarized.•This digest describes the transition metal-catalyzed or -free arylation.•The metastable arylsulfonium ...intermediates for arylation are also discussed.
Arylsulfonium salts are versatile arylation reagents for the synthesis of functional molecules. This digest focuses on the recent advances on the transition metal-mediated or -free arylation using the stable arylsulfonium salts or the metastable arylsulfonium intermediates as arylation agents.
A simple and efficient method for transition‐metal‐free N‐arylation of various amines by triarylsulfonium triflates is described. Both aliphatic and aromatic amines were smoothly converted at 80 °C ...in the presence of tBuOK or KOH to give the corresponding mono N‐arylated products in good to high yields. The molar ratios of the reactants and the choice of bases had a big effect on the reaction. When a large excess of Ph3SOTf and tBuOK were employed for primary amines under the standard conditions, the bis(N‐phenyl) products were predominantly formed. This method was also applicable to the synthesis of bioactive N‐phenyl amino acid derivatives. The control experiments, the deuterium labelling study, and the presence of regioisomers of N‐arylated products when using 4‐substituted triarylsulfonium triflates suggested that the reaction might proceed through an aryne intermediate. The present protocol demonstrated that triarylsulfonium salts are versatile arylation reagents in the construction of CAr−N bonds.
Transition‐metal‐free N‐arylation of aliphatic and aromatic amines by Ar3SOTf in the presence of tBuOK or KOH gave the mono N‐arylated products in good to high yields. The reaction might proceed via an aryne intermediate. The molar ratios of the reactants and the choice of bases had a big influence on the reaction. When a large excess of Ph3SOTf and tBuOK were employed for primary amines, the corresponding bis(N‐phenyl) compounds were obtained as the major products.
With the rapid development of functional requirements in the emerging Industry 4.0 era, modern industrial control systems (ICSs) are no longer isolated islands, making them more vulnerable to various ...cyberattack threats. Cyberattacks on ICSs may have disruptive consequences, such as significant social and economic losses. To proactively address the security issue of ICSs, this article presents a unified architectural approach from the perspectives of cyberthreats on ICSs, security-related ICS technologies, and methods for ICSs. It incorporates secure networks, secure control systems, secure physical processes, and their interactions seamlessly into a unified framework. To increase the resistance of ICSs against intrusions, the network security in our architectural approach is to secure the data in motion through the integration of secure network architecture, secure industrial network protocols, and secure end-to-end communications. The protection of control systems in our architectural approach is risk-based and hierarchical and encompasses prevention- and tolerance-centric defenses. It provides a layer-by-layer defense so that an acceptable level of cybersecurity risk is achieved and maintained. Aiming to maintain the stable operation of physical ICS processes, the secure control in our architectural approach implements a security process against process-aware attacks through a resilient safety control scheme. The global and systematic architectural approach presented in this article for the ICS cybersecurity will help facilitate the design and implementation of cyberattack-resilient ICSs in the networked world. For further development of ICS security technologies, emerging challenges are identified and discussed to motivate future research efforts.
With the increasing deployment of data network technologies in industrial control systems (ICSs), cybersecurity becomes a challenging problem in ICSs. Dynamic cybersecurity risk assessment plays a ...vital role in ICS cybersecurity protection. However, it is difficult to build a risk propagation model for ICSs due to the lack of sufficient historical data. In this paper, a fuzzy probability Bayesian network (FPBN) approach is presented for dynamic risk assessment. First, an FPBN is established for analysis and prediction of the propagation of cybersecurity risks. To overcome the difficulty of limited historical data, the crisp probabilities used in standard Bayesian networks are replaced in our approach by fuzzy probabilities. Then, an approximate dynamic inference algorithm is developed for dynamic assessment of ICS cybersecurity risk. It is embedded with a noise evidence filter in order to reduce the impact from noise evidence caused by system faults. Experiments are conducted on a simplified chemical reactor control system to demonstrate the effectiveness of the presented approach.
In this paper, a multi-party quantum private comparison (MQPC) scheme is suggested based on entanglement swapping of Bell entangled states within
d
-level quantum system, which can accomplish the ...equality comparison of secret binary sequences from
n
users via one execution of scheme. Detailed security analysis shows that both the outside attack and the participant attack are ineffective. The suggested scheme needn’t establish a private key among
n
users beforehand through the quantum key distribution (QKD) method to encrypt the secret binary sequences. Compared with previous MQPC scheme based on
d
-level Cat states and
d
-level Bell entangled states, the suggested scheme has distinct advantages on quantum resource, quantum measurement of third party (TP) and qubit efficiency.
Abstract
Accurate forecasting tourism demand is crucial for improving the economic benefits of tourist attractions, but it is a challenging task. In this paper, we propose an effective daily tourism ...forecast model, principal component analysis‐grey wolf optimizer‐extreme learning machine (PCA‐GWO‐ELM), based on Baidu index data, holiday data, and weather data. Our model uses PCA to reduce the dimensionality of the data and employs the GWO to optimize the number of neural networks in the hidden layer of the ELM model, improving its forecast performance. We conduct an empirical study using the collected tourist data of Mount Siguniang. The results show that the proposed hybrid forecasting model outperforms other models in daily tourism demand forecasting, making it a potential candidate method for practitioners and researchers studying tourism demand forecasting.
Half‐light and half‐matter exciton polaritons have demonstrated profound impacts on coherent quantum phenomena. Two‐dimensional (2D) organic−inorganic perovskite semiconductors, exhibiting large ...exciton binding energy and spin‐based behavior, are an excellent platform for the study of exciton polaritons at room temperature. However, the implementation of these fascinating coherent phenomena is still constrained by the lack of an understanding of the crucial polariton–polariton interaction effects. Here, an experimental observation of spin‐dependent polariton–polariton interactions in a prototype 2D organic−inorganic perovskite microcavity by circularly polarization‐resolved transient absorption (TA) measurements is reported. A power‐dependent blue shift of the lower polariton bands with the same spin is clearly revealed, whereas the energy band of the polariton bands with the opposite spin is almost not changed. Spectacularly, it is found that the energy band blue shift mainly takes place before the spin depolarization, which provides accurate evidence for the spin‐dependent polariton–polariton interactions. Furthermore, the strong coherent polariton–phonon coupling of perovskite microcavity has also been detected firstly in ultrafast TA dynamics. These results demonstrate that microcavity polaritons inheriting the matter properties from their excitonic constituents exhibit strong nonlinear interactions and pave the way for realizing coherent quantum phenomena at room temperature.
The dynamics of spin‐dependent polariton–polariton interactions in a two‐dimensional layered halide perovskite microcavity is observed by femtosecond transient absorption spectroscopy with circularly polarized pump/probe lights at room temperature. The cause of the obvious power‐dependent blue shift in lower polariton bands with the same spin, together with the polaritons inheritance of excitons nature, is discussed in detail.
Baicalein, a widely used Chinese herbal medicine, has multiple pharmacological activities. However, the precise mechanisms of the anti-proliferation and anti-metastatic effects of baicalein on ...gallbladder cancer (GBC) remain poorly understood. Therefore, the aim of this study was to assess the anti-proliferation and anti-metastatic effects of baicalein and the related mechanism(s) on GBC. In the present study, we found that treatment with baicalein induced a significant inhibitory effect on proliferation and promoted apoptosis in GBC-SD and SGC996 cells, two widely used gallbladder cancer cell lines. Additionally, treatment with baicalein inhibited the metastasis of GBC cells. Moreover, we demonstrated for the first time that baicalein inhibited GBC cell growth and metastasis via down-regulation of the expression level of Zinc finger protein X-linked (ZFX). In conclusion, our studies suggest that baicalein may be a potential phytochemical flavonoid for therapeutics of GBC and ZFX may serve as a molecular marker or predictive target for GBC.
Triple-negative breast cancer (TNBC) remains an unmet medical challenge. We investigated metabolic dysregulation in TNBCs by using our multi-omics database (n = 465, the largest to date). TNBC ...samples were classified into three heterogeneous metabolic-pathway-based subtypes (MPSs) with distinct metabolic features: MPS1, the lipogenic subtype with upregulated lipid metabolism; MPS2, the glycolytic subtype with upregulated carbohydrate and nucleotide metabolism; and MPS3, the mixed subtype with partial pathway dysregulation. These subtypes were validated by metabolomic profiling of 72 samples. These three subtypes had distinct prognoses, molecular subtype distributions, and genomic alterations. Moreover, MPS1 TNBCs were more sensitive to metabolic inhibitors targeting fatty acid synthesis, whereas MPS2 TNBCs showed higher sensitivity to inhibitors targeting glycolysis. Importantly, inhibition of lactate dehydrogenase could enhance tumor response to anti-PD-1 immunotherapy in MPS2 TNBCs. Collectively, our analysis demonstrated the metabolic heterogeneity of TNBCs and enabled the development of personalized therapies targeting unique tumor metabolic profiles.
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•The metabolic reprogramming and heterogeneity of TNBC is systematically characterized•TNBCs are classified into three subtypes on the basis of metabolic pathways•Three subtypes show distinct sensitivities to various metabolic inhibitors•Inhibition of LDH enhances tumor response to anti-PD-1 immunotherapy in MPS2 TNBCs
Gong et al. reveal the metabolic heterogeneity of triple-negative breast cancer and identify three metabolic-pathway-based subtypes with distinct molecular features and sensitivities to various metabolic inhibitors. They find that inhibition of lactate dehydrogenase could enhance the anti-PD-1 immunotherapy response in a certain subtype of triple-negative breast cancer.
Unveiling the structural evolution of single-crystalline compounds based on certain building units may help greatly in guiding the design of complex structures. Herein, a series of praseodymium ...antimony oxohalide crystals have been isolated under solvothermal conditions via adjusting the solvents used, that is, HN(CH
CH
)
Fe
(2,2'-bpy)
Pr
Sb
O
Cl
·EtOH (
) (2,2'-bpy = 2,2'-bipyridine), HN(CH
CH
)
Fe
(2,2'-bpy)
Pr
Sb
O
Cl
)
Cl·N(CH
CH
)
·2H
O (
), and (H
O)Pr
Sb
O
Cl
(TEOA)
·2.5EtOH (
) (TEOA = mono-deprotonated triethanolamine anion). Single-crystal X-ray diffraction analysis revealed that all the three structures feature an anionic
chain of Pr
Sb
O
Cl
as the tertiary building unit (TBU), which is formed by interconnections of praseodymium antimony oxochloride clusters (denoted as {Pr
Sb
}) as secondary building units. Interestingly, different arrangements or linkages of chain-like TBUs result in one-dimensional, two-dimensional layered, and three-dimensional structures of
,
, and
, respectively, thus demonstrating clearly the structural evolution of metal oxohalide crystals. The title compounds have been characterized by elemental analysis, powder X-ray diffraction, thermogravimetric analysis, and UV-Vis spectroscopy, and the photodegradation for methyl blue in an aqueous solution of compound
has been preliminarily studied. This work offers a way to deeply understand the assembly process of intricate lanthanide-antimony(III) oxohalide structures at the atomic level.
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