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Here we present a modular, chemo‐, regio‐, and stereoselective synthesis of fully‐substituted and configuration‐defined alkyl vinyl ethers (AVEs) using simple chemical feedstocks. The distinctive approach involves the chemo‐ and regioselective functionalization of the CF2 unit in gem‐difluorinated cyclopropanes with O−H and C−H nucleophiles in a specific order. The resulting highly functionalized cyclopropanyl ethers then undergo a stereoselective ring‐opening process to produce fully‐substituted and configuration‐defined AVEs. These AVEs are rarely accessible through conventional methods and are easily transformable. Mechanistic experiments indicate that the success of this method relies on the use of dual‐functional copper catalysis, which is involved in both the functionalization of the CF2 unit and the subsequent ring‐opening process. [ABSTRACT FROM AUTHOR]

Here we present a modular, chemo‐, regio‐, and stereoselective synthesis of fully‐substituted and configuration‐defined alkyl vinyl ethers (AVEs) using simple chemical feedstocks. The distinctive approach involves the chemo‐ and regioselective functionalization of the CF2 unit in gem‐difluorinated cyclopropanes with O−H and C−H nucleophiles in a specific order. The resulting highly functionalized cyclopropanyl ethers then undergo a stereoselective ring‐opening process to produce fully‐substituted and configuration‐defined AVEs. These AVEs are rarely accessible through conventional methods and are easily transformable. Mechanistic experiments indicate that the success of this method relies on the use of dual‐functional copper catalysis, which is involved in both the functionalization of the CF2 unit and the subsequent ring‐opening process. [ABSTRACT FROM AUTHOR]

Despite significant progress, precise control of the dispersion of ruthenium (Ru) nanoparticles (NPs) on the carrier, reduction of their aggregation and leaching during water splitting is always a challenging issue. In this work, metal-organic frameworks (MOFs) derived Co 7 Fe 3 alloy/Co NPs embedded in nitrogen-doped carbon and nitrogen-doped carbon nanotubes (FeCoSG/NCNT) with a three-dimensional (3D) spider-egg structure are synthesized by chemical vapor deposition (CVD) technique. Then, Ru NPs are uniformly loaded on the FeCoSG/NCNT through impregnation and reduction. The obtained FeCoSG/NCNT@Ru possesses enriched mesopore and high conductivity. In addition, the Ru NPs synergize with non-precious metal active sites to promote hydrogen-evolution-reaction (HER), which lowers the need for precious metals while maintaining excellent performance. The obtained FeCoSG/NCNT@Ru only requires a low overpotential of 21.1 mV to attain a current density of 10 mA cm−2 in 1 M KOH towards HER, which is smaller than the benchmark catalyst Pt/C (∼30.1 mV). Moreover, it shows ultra-high stability, which can work continuously at current densities of 10, 20, and 30 mA cm−2 for 25 h without degradation, respectively. The study presents insight on the design of advanced support and the construction of highly active and durable electrocatalysts. [Display omitted] • Co 7 Fe 3 alloy/Co NPs embedded in MOF-derived NC encapsulated by NCNT. • The N doping brings a favorable effect on the regulation of Ru distribution. • The unique spider-egg structure provides an abundance of Ru attachment sites. • FeCoSG/NCNT@Ru is a highly efficient and stability HER catalyst. • It exhibits an extremely small overpotential of 21.1 mV at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

The development of sodium‐ion battery (SIB) anodes is still hindered by their rapid capacity decay and poor rate capabilities. Although there have been some new materials that can be used to fabricate stable anodes, SIBs are still far from wide applications. Strategies like nanostructure construction and material modification have been used to prepare more robust SIB anodes. Among all the design strategies, the hollow structure design is a promising method in the development of advanced anode materials. In the past decade, research efforts have been devoted to modifying the synthetic route, the type of templates, and the interior structure of hollow structures with high capacity and stability. A brief introduction is made to the main material systems and classifications of hollow structural materials first. Then different morphologies of hollow structural materials for SIB anodes from the latest reports are discussed, including nanoboxes, nanospheres, yolk shells, nanotubes, and other more complex shapes. The most used templates for the synthesis of hollow structrual materials are covered and the perspectives are highlighted at the end. This review offers a comprehensive discussion of the synthesis of hollow structural materials for SIB anodes, which could be potentially of use to research areas involving hollow materials design for batteries. [ABSTRACT FROM AUTHOR]

Information asymmetry is particularly common in the supply chain framework. As we know, the downstream retailer usually knows more about the market demand information than the upstream manufacturer because of her proximity to consumers. This paper considers a supply chain that a manufacturer sells products to consumers via a retailer in a local market. Besides, the manufacturer has an option to establish a direct online channel in the overseas market, in which the retailer can sell products as a gray marketer to earn an extra profit. Both markets' demand information is transparent to the retailer but asymmetric to the manufacturer. There are two side an opposite effects of information sharing on the retailer. The positive effect is that when she withholds demand information she can possess an information advantage. However, the negative effect is that when the retailer shares her private demand information, especially when the manufacturer enters the overseas market, the retailer's profit may be negatively affected because of the competition. Therefore, whether the retailer has motivation to share her private demand information with the manufacturer is an intriguing yet unanswered question. We first characterize the tradeoff in three supply chain structures, Local Market, Dual Market and Gray Market. Then, we obtain the equilibrium results of each case and find that a co-opetition strategy may arise because of competition when considering gray market and dual-channel. Finally, we uncover the underlying reasons and develop valuable insights. [ABSTRACT FROM AUTHOR]

The detection of audio tampering plays a crucial role in ensuring the authenticity and integrity of multimedia files. This paper presents a novel approach to identifying tampered audio files by leveraging the unique Electric Network Frequency (ENF) signal, which is inherent to the power grid and serves as a reliable indicator of authenticity. The study begins by establishing a comprehensive Chinese ENF database containing diverse ENF signals extracted from audio files. The proposed methodology involves extracting the ENF signal, applying wavelet decomposition, and utilizing the autoregressive model to train effective classification models. Subsequently, the framework is employed to detect audio tampering and assess the influence of various environmental conditions and recording devices on the ENF signal. Experimental evaluations conducted on our Chinese ENF database demonstrate the efficacy of the proposed method, achieving impressive accuracy rates ranging from 91% to 93%. The results emphasize the significance of ENF-based approaches in enhancing audio file forensics and reaffirm the necessity of adopting reliable tamper detection techniques in multimedia authentication. [ABSTRACT FROM AUTHOR]

This study was aiming at the differences in the aroma, flavor compounds, and bioactivities of essential oil of Coreopsis tinctoria flower (CTFEO) and essential oil of Chrysanthemum morifolium flower (CMFEO). Both essential oils were extracted by steam distillation. Their flavor compositions were determined by GC-MS and the antioxidant, antibacterial, and anti-inflammatory activities were also evaluated. It was found that CTFEO possessed a special medicinal herb odor, which was obviously stronger than those of CMFEO. A preferred condition for steam distillation was flower powder–water ratio of 7.5:100 and extraction for more than 3.0 h. Interestingly, the main flavor compounds of CTFEO were determined as D-limonene (34.54%), cis-carveol (5.49%), trans-α-bergamotene (4.44%), and α-pinene (3.90%), which were quite different from those of CMFEO. CTFEO showed better antioxidant activities with IC50 value of 121.4 ± 9.8 μg/mL than those of CMFEO. It also exhibited stronger antibacterial effects than those of CMFEO, with minimal inhibitory concentrations (MICs) ranging from 0.183 to 1.412 mg/mL against six strains of bacteria. Moreover, CTFEO was also found to exhibit strong anti-inflammatory effects that reduced the LPS-induced RAW 264.7 cell mRNA expression of the cytokines IL-1β, IL-6, and TNF-α at a concentration of 10.0 μg/mL. All these results suggest that the aroma, flavor compounds, and bioactivities of the two essential oils were quite different and they could be used as tea, drink, and food additive in the food industry for further development. [ABSTRACT FROM AUTHOR]

Hydrogen gas production can be produced from dimethylamine borane by the catalytic effect of metal nanoparticles. Past research efforts were heavily focused on dehydrogenation in organic solvents. In this study, hydrolysis of the borane in aqueous solutions was investigated, which bears two significant advantages: that two-thirds of the hydrogen generated originate from water and that the hydrogen storage materials are non-flammable. Polymer hydrogels serve as good carriers for metal particles as catalysts in aqueous solutions. Kinetic analysis of hydrogen production was performed for Ni/Pd bimetallic nanoclusters dispersed in a polymer hydrogel with a 3-D network structure. The reaction catalyzed by the bimetallic nanoclusters has an activation energy of only 34.95 kJ/mol, considerably lower than that by Ni or other metal catalysts reported. A significant synergistic effect was observed in the Ni/Pd bimetallic catalysts (Ni–Pd = 20/1) with a higher activity than Pd or Ni alone. This proves the alloy nature of the nanoparticles in the borane hydrolysis and the activation of water and borane by both metals to break the O–H and B–H bonds. The hydrogel with the Ni/Pd metal can be recycled with a much longer lifetime than all the previously prepared catalysts. The aqueous borane solutions with a polymer hydrogel can become a more sustainable hydrogen supplier for long-term use. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) with abundant active sites, a class of materials composed of metal nodes and organic ligands, is widely used for photocatalytic degradation of pollutants. However, the rapid recombination of photoinduced carriers of MOFs limits its photocatalytic degradation performance. Herein, Ti3C2Tx nanosheets‐based NH2‐MIL‐101(Fe) hybrids with Schottky‐heterojunctions were fabricated by in situ hydrothermal assembly for improved photocatalytic activity. The photodegradation efficiencies of the NH2‐MIL‐101(Fe)/Ti3C2Tx (N‐M/T) hybrids for phenol and chlorophenol were 96.36 % and 99.83 % within 60 minutes, respectively. The N‐M/T Schottky‐heterojunction duly transferred electrons to the Ti3C2Tx nanosheets surface via built‐in electric fields, effectively suppressing the recombination of photogenerated carriers, thereby improving the photocatalytic performance of NH2‐MIL‐101(Fe). Moreover, the Fe‐mixed‐valence in the N‐M/T led to improvement in the efficiency of the in situ generated photo‐Fenton reactions, further enhancing the photocatalytic activity with more generated reactive oxygen species (ROS). The study proposes a highly effective removal of phenolic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

This work investigates a service-oriented manufacturing supply chain in which a manufacturer and an operator make decisions about equipment quality and maintenance service. Both the manufacturer and the operator have to make tradeoffs between equipment quality and maintenance service to maximize their own profit, which can lead to supply chain conflict. Decision models under decentralized decisions are formulated first for the manufacturer and the operator to make their respective independent optimal decisions, and a decision model under centralized decisions is formulated to obtain optimal decisions for the supply chain. The results show that channel coordination is not achievable and an agreement cannot be reached with decentralized decisions. To address this issue, two, i.e., a cost-sharing and a performance-based, strategies are introduced to coordinate the supply chain. The results reveal that the manufacturer and the operator are motivated to find the optimal decisions to maximize the profit of the supply chain when the subsidy rate or the penalty rate is equal to the profit margin of the operator. The models and the coordination strategies are extended to the situation considering the learning behavior of the manufacturer. The results show that the learning behavior impacts the profit of the supply chain with coordination and the preferences of the coordination strategy in the supply chain. [ABSTRACT FROM AUTHOR]

In this study, twenty-three ent -eudesmane sesquiterpenoids (1 – 23) including fifteen previously undescribed ones, named eutypelides A–O (1 – 15) were isolated from the marine-derived fungus Eutypella sp. F0219. Their planar structures and relative configurations were established by HR-ESIMS and extensive 1D and 2D NMR investigations. The absolute configurations of the previously undescribed compounds were determined by single-crystal X-ray diffraction analyses, modified Mosher's method, and ECD calculations. Structurally, eutypelide A (1) is a rare 1,10- seco - ent -eudesmane, whereas 2 – 15 are typically ent -eudesmanes with 6/6/-fused bicyclic carbon nucleus. The anti-neuroinflammatory activity of all isolated compounds (1 − 23) was accessed based on their ability to NO production in LPS-stimulated BV2 microglia cells. Compound 16 emerged as the most potent inhibitor. Further mechanistic investigation revealed that compound 16 modulated the inflammatory response by decreasing the protein levels of iNOS and increasing ARG 1 levels, thereby altering the iNOS/ARG 1 ratio and inhibiting macrophage polarization. qRT-PCR analysis showed that compound 16 reversed the LPS-induced upregulation of pro-inflammatory cytokines, including iNOS, TNF-α, IL-6, and IL-1β, at both the transcriptional and translational levels. These effects were linked to the inhibition of the NF-κB pathway, a key regulator of inflammation. Our findings suggest that compound 16 may be a potential structure basis for developing neuroinflammation-related disease therapeutic agents. Fifteen previously undescribed ent -eudesmane sesquiterpenoids (1 – 15) were isolated from the marine-derived fungus Eutypella sp. F0219. Compound 16 inhibited LPS stimulation induced macrophage polarization alongside canonical inflammatory-regulated pathway NF-κB suppression. [Display omitted] • 15 previously undescribed ent -eudesmane sesquiterpenoids were isolated. • Compound 16 displayed potent anti-neuroinflammatory activity. • Compound 16 inhibited LPS stimulation induced macrophage polarization. • Compound 16 suppressed the NF-κB pathway. [ABSTRACT FROM AUTHOR]

This paper studies the effect of perturbations on the gradient flow of a general nonlinear programming problem, where the perturbation may arise from inaccurate gradient estimation in the setting of data-driven optimization. Under suitable conditions on the objective function, the perturbed gradient flow is shown to be small-disturbance input-to-state stable (ISS), which implies that, in the presence of a small-enough perturbation, the trajectories of the perturbed gradient flow must eventually enter a small neighborhood of the optimum. This work was motivated by the question of robustness of direct methods for the linear quadratic regulator problem, and specifically the analysis of the effect of perturbations caused by gradient estimation or round-off errors in policy optimization. We show small-disturbance ISS for three of the most common optimization algorithms: standard gradient flow, natural gradient flow, and Newton gradient flow. [ABSTRACT FROM AUTHOR]

The Calcium-sensing receptor (CaSR) participates in the regulation of gastrointestinal (GI) motility under normal conditions and might be involved in the regulation of GI dysmotility in patients with Parkinson's disease (PD). CaSR antagonist-NPS-2143 was applied in in vivo and ex vivo experiments to study the effect and underlying mechanisms of CaSR inhibition on GI dysmotility in the MPTP-induced PD mouse model. Oral intake of NPS-2143 promoted GI motility in PD mice as shown by the increased gastric emptying rate and shortened whole gut transit time together with improved weight and water content in the feces of PD mice, and the lack of influence on normal mice. Meanwhile, the number of cholinergic neurons, the proportion of serotonergic neurons, as well as the levels of acetylcholine and serotonin increased, but the numbers of nitrergic and tyrosine hydroxylase immunoreactive neurons, and the levels of nitric oxide synthase and dopamine decreased in the myenteric plexus in the gastric antrum and colon of PD mice in response to NPS-2143 treatment. Furthermore, the numbers of c-fos positive neurons in the nucleus tractus solitarius (NTS) and cholinergic neurons in the dorsal motor nucleus of the vagus (DMV) increased in NPS-2143 treated PD mice, suggesting the involvement of both the enteric (ENS) and central (CNS) nervous systems. However, ex vivo results showed that NPS-2143 directly inhibited the contractility of antral and colonic strips in PD mice via a non-ENS mediated mechanism. Further studies revealed that NPS-2143 directly inhibited the voltage gated Ca2+ channels, which might, at least in part, explain its direct inhibitory effects on the GI muscle strips. CaSR inhibition by its antagonist ameliorated GI dysmotility in PD mice via coordinated neuronal regulation by both ENS and CNS in vivo , although the direct effects of CaSR inhibition on GI muscle strips were suppressive. [Display omitted] • Oral intake of NPS-2143 promoted gastrointestinal motility. • ENS and CNS are involved in the effects of NPS-2143 in vivo. • Direct effects of NPS-2143 on gastrointestinal strips is suppressive via VGCC. [ABSTRACT FROM AUTHOR]

The doping of transition metal ions in the up‐conversion (UC) luminescent material doped with Yb3+/Ln3+ is a facile way to increase their UC luminescence intensities and alter their colors. In this study, La2MgTiO6:Yb3+/Mn4+/Ln3+ (Ln3+ = Er3+, Ho3+, and Tm3+) phosphors showing excellent luminescence properties were prepared by a solid‐state method. The sensitivity of the La2MgTiO6:Yb3+/Ln3+/Mn4+ phosphor was double that without Mn4+, because Mn4+ affects the UC emissions of Ln3+ via energy transfer between these ions. Moreover, Mn4+ also acts as a down‐conversion activator, which can combine with UC ions to achieve multi‐mode luminescence at different wavelengths. Under 980 nm excitation, these samples emit green light (from Er3+ and Ho3+) and blue light (from Tm3+). In contrast, under 365 nm excitation, they emit red light (from Mn4+). Further testing revealed that the La2MgTiO6:Yb3+/Mn4+/Ln3+ phosphors have potential applications in temperature sensing and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Plasmonic nanozymes with both plasmonic and biocatalytic properties stand out due to their distinctive localized surface plasmon resonance (LSPR) feature and adjustable catalytic activity, while the enhancement effect of present reported plasmon excitation remains relatively low. Here, a plasmonic nanozyme of Cu 3 P nanoparticles (Cu 3 P NPs) with LSPR characteristics and intrinsic peroxidase (POD)-like activity was prepared via simple gas-solid reaction strategy, which presents significantly enhanced POD-like activity under plasmon stimulation than that without LSPR excitation, with catalytic constants for TMB and H 2 O 2 83 and 127 times higher than those without LSPR excitation respectively. On the one hand, the Cu 3 P plasmonic nanozyme generated abundant high-energy hot carriers under near-infrared (NIR) stimulation to promote cracking of H 2 O 2 to produce plentiful reactive oxide species (ROS); on the other hand, the LSPR-induced photothermal effect on Cu 3 P plasmonic nanozyme greatly improves the reaction kinetics, thus making a significantly boosts POD-like activity. According to the excellent POD-like activity of Cu 3 P plasmonic nanozyme and 8-hydroxyquinoline (8-HQ)-mediated chromaticity switch, a highly sensitive Cr (VI) chrominance sensing platform was developed with a detection limit of 9.6 nM within a range from 0.01 to 20 μM. This study spotlights the high utilization efficiency of plasmon stimulation for enzyme-like activity tuning. [Display omitted] • Cu 3 P with plasma effect showed significantly enhanced peroxidase-like activity. • Enhanced peroxidase-like activity came from hot carriers and photothermal effect. • An 8-HQ-mediated chromaticity switch was developed for Cr (VI) detection. • Enhanced peroxidase-like activity contributed to improve detection sensitivity. [ABSTRACT FROM AUTHOR]

Gem -difluorinated cyclopropanes have become an important type of allyl surrogate in transition-metal-catalyzed ring-opening processes, as demonstrated recently through various important advances, especially with palladium catalysis. The versatile fluorinated allyl species generated in this way from gem -difluorinated cyclopropanes exhibit unique advantages compared with conventional allyl sources. By using gem -difluorinated cyclopropanes as allyl surrogates, we achieved a direct allylation of simple arenes through rhodium catalysis under mild conditions. This transformation permits directing-group-free allylation of simple arenes, including electron-neutral, electron-rich, and electron-deficient ones. Here, we give a brief introduction to this area and we discuss our thoughts regarding our recent work and its design. 1 Introduction 2 Our Design 3 Condition Optimization and Substrate Scope 4 Applications in Synthesis 5 Mechanistic Discussions 6 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

One new virginiamycin derivative, 'beilunmycin' (1), and three known virginiamycin antibiotics, 16-hydroxy-virginiamycin M1 (2), virginiamycin M2 (3), and virginiamycin M1 (4), were isolated from the culture of a mangrove-derived endophytic Streptomyces sp. 2BBP-J2. The structures were characterized on the basis of their spectroscopic data, and the absolute configuration of 1 was established by ECD calculations. Compounds 1–4 exhibited antibacterial activities against Gram-positive bacteria, with MIC values in the range of 0.5–16 μg/ml. All the compounds demonstrated strong protein translation-stalling activity, with minimal concentrations detected with pDualrep2 in the range of 1.9–5.9 nmol. [ABSTRACT FROM AUTHOR]

Based on the laccase-mimicking activity of Cu2+-modified University of Oslo (UiO) metal–organic framework (UiO-67-Cu2+), we developed a colorimetric sensor array for distinguishing a series of phenols with different number and position of substituted hydroxyl group (-OH) and different substituent group on the benzene ring, including phenol, catechol, quinol, resorcinol, pyrogallol, phloroglucinol, o-chlorophenol, o-aminophenol, and o-nitrophenol. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of phenolic compounds were obtained by theoretical calculation. The results show that the lower the LUMO energy level, the easier the chromogenic reaction occurs. The UiO-67-Cu2+-catalyzed phenol chromogenic reaction showed a good linearity in the range from 0.1 to 200 μM with limit of detection approximately 61 nM. Through the detection of phenol in tap water and river water, the recovery rate and RSD (n = 3) were calculated as 94.1~103% and 1.0~3.3, respectively, showing good recovery, reliable results, and outstanding stability. Therefore, the proposed colorimetric sensor array will have a great potential for the detection of phenols in the environment. [ABSTRACT FROM AUTHOR]

The contradiction between supply and demand of energy leads to more and more attention on the large-scale energy storage technology; Compressed Air Energy Storage (CAES) technology is a new energy storage technology that is widely concerned in the world. The research of coupled heat transfer and seepage in fractured surrounding rocks is the necessary basis to evaluate the operation safety and effectiveness of CAES. Current studies point to the possibility of cracking in concrete liner seals, but the thermodynamic processes and leakage characteristics of compressed air in the presence of cracking and the heat transfer characteristics of seepage have not been addressed and reported. In order to investigate the leakage, the gas seepage and heat transfer law in fractured rock when the hard rock CAES gas reservoir seal cracks, the COMSOL fracture Darcy module, and the non-Darcy Forchheimer model are used as the constitutive seepage. The global ODE is used to calculate the thermodynamic process of compressed air in gas storage with coupled seepage and heat transfer process. The pressure and temperature of compressed air are obtained as the unsteady boundary of the seepage heat transfer model. A program for calculating the seepage and heat transfer characteristics of fractured surrounding rock in the CAES gas reservoir is established. On this basis, with the proposed Suichang CAES cavern as the background, the seepage and heat transfer characteristics of the fractured surrounding rock of the gas storage are studied. The results showed that when there are fewer cracks in the lining and surrounding rock of the air reservoir, the air pressure decreases due to a small amount of air leakage after 30 operation cycles, and the leakage rate of each cycle is 0.7% of the gas storage capacity, but it still meets the engineering requirements. If the plant is operating under these conditions, the charging rate will need to be increased by 1.2 kg/s per cycle charging stage. In the discharging and power generation phase, the high-pressure air that previously percolated into the rock mass cracks could flow back into the air storage through the lining cracks. Therefore, it is incorrect and unreliable to consider the gas which flows out from the inner surface of the lining as unusable. When the lining crack width is less than 0.3 mm, the seepage flow is Darcy flow and the non-Darcy effect can be ignored; when the lining crack width is greater than 0.5 mm, the non-Darcy effect of seepage cannot be ignored. The gas velocity in the surrounding rock fracture medium is on the order of 0.01 m/s with an influence range of over 100 m, and the gas velocity in the pore medium is on the order of 10-6 m/s with an influence range of 50 m. The findings of this study contribute to a better understanding of the interaction between the thermodynamic properties of compressed air and the seepage heat transfer process in compressed air storage underground reservoirs, as well as the gas leakage process in the event of liner seal cracking. [ABSTRACT FROM AUTHOR]

Herein, we report a rhodium catalyzed directing‐group free regioselective C−H allylation of simple arenes. Readily available gem‐difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C−C and C−F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late‐stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram‐scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio‐enriched gem‐difluorinated cyclopropanes. [ABSTRACT FROM AUTHOR]

Herein, we report a rhodium catalyzed directing‐group free regioselective C−H allylation of simple arenes. Readily available gem‐difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C−C and C−F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late‐stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram‐scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio‐enriched gem‐difluorinated cyclopropanes. [ABSTRACT FROM AUTHOR]

Herein, we report a rhodium catalyzed directing‐group free regioselective C−H allylation of simple arenes. Readily available gem‐difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C−C and C−F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late‐stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram‐scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio‐enriched gem‐difluorinated cyclopropanes. [ABSTRACT FROM AUTHOR]

Background and aim: We previously identified forkhead box (FOX) O4 mRNA as a predictor in gastric cancer (GC). However, the underlying mechanism has yet to be elucidated. We aimed to illustrate the mechanism by which FOXO4 regulated glycolysis under hypoxia in GC. Methods: FOXO4 protein expression was investigated by immunohistochemical staining of 252 GC and their normal adjacent tissues. We restored or silenced FOXO4 expression in GC cell lines to explore the underlying mechanisms. Results: FOXO4 was downregulated in GC. Loss of FOXO4 expression was validated in univariate and multivariate survival analysis as an independent prognostic predictor for overall survival (P < 0.05) and disease‐free survival (P<0.05). Restored FOXO4 expression significantly impaired the glycolysis rate in GC cells, while silencing FOXO4 expression enhanced glycolysis rate. FOXO4 expression was inversely associated with maximum standardized uptake value in mice models and patient samples. Mechanistically, FOXO4 bound to the glycolytic enzyme lactate dehydrogenase (LDH)A promoter and inactivated its activity in a dose‐dependent manner (P < 0.05). Finally, we determined that FOXO4 was a transcriptional target of hypoxia‐inducible factor (HIF) ‐1α, which is central in response to hypoxia. Conclusions: Our data suggested that FOXO4 plays a key role in the regulation of glycolysis in GC, and disrupting the HIF‐1α‐FOXO4‐LDHA axis might be a promising therapeutic strategy for GC. [ABSTRACT FROM AUTHOR]

In this paper, a heterogeneous multi-core SoC is modeled and analyzed, and the implementation problem of LT code' (Luby Transform code) encoding on a heterogeneous multi-core SoC is transformed into a mapping problem of LT code encoding subtasks on the heterogeneous multi-core SoC, Besides, a task mapping method based on genetic algorithm is given. Finally, the encoder is implemented on the heterogeneous multi-core SoC based on Xilinx ZYNQ-7000. Experimental results show that the Experimental results show that the designed LT code encoder can adapt to different performance and resource requirements, increasing the practicability of the hardware platform and the flexibility of application system design. [ABSTRACT FROM AUTHOR]

The tapertail anchovy Coilia brachygnathus, a commercially important species mainly distributed along the mid‐lower Chang‐Jiang basin, is by far the most dominant species in Lake Honghu. To figure out its success in this semiclosed lake, some basic biological parameters of this anchovy were analysed based on samples seasonally collected from October 2020 to December 2021. The results demonstrated that the age classes of fished individuals varied from 0.5 to 3.5, with the majority (97.36%) being between 0.5 and 3 years old. The size at 50% maturity of 17.2 cm total length (TL) for females and 19.0 cm TL for males corresponded to 1 and 1.6 years, respectively. Coilia brachygnathus has a short life span, early sexual maturity and a relatively fast growth rate. The flourishing of the fish in the lake is mainly attributed to its short life span, early maturity, fast growth rate, closed fishing, pelagic spawners, the availability of plenty of food and low predation effect on it. Age 3.5 year occurs in an extremely small percentage of the total (<3%), indicating that a large number of larger‐sized or older fish died after spawning, which is probably one of the major sources of water pollution if the closed fishing measure is adopted in Lake Honghu. Thus, individuals older than 2 years or more than 20.0 cm TL should be harvested. These findings have important management implications for the fish resources in Lake Honghu and beyond. [ABSTRACT FROM AUTHOR]

In the current study, a new heteroleptic triorganobismuth (V) complex with the chemical formula of Bi(phenyl)3(2,3-dfa)2 has been successfully prepared by using C donor phenyl ring and O donor 2,3-difluorobenzoic acid (2,3-H2dfa) ligands, which has been fully characterized by single crystal X‐ray crystallography, elemental analysis, powder X-ray diffraction along with the thermogravimetric analysis. Furthermore, a green hand grinding technique was used to get the nanocrystals of 1 with an average size of 200 nm as revealed via the scanning electron microscopy (SEM). The inhibitory effect of BT474 cells proliferation after nano 1 treatment was detected with CCK-8 assay. The apoptosis of BT474 cells was measured with FITC-Annexin V/PI double staining assay, the influence on ROS accumulation was determined with DCFH-DA staining. [ABSTRACT FROM AUTHOR]

Kinetic investigations including quasi-classical trajectory and canonical unified statistical theory method calculations are carried out on a potential energy surface for the hydrogen-abstraction reaction from methane by atom O(3P). The surface is constructed using a modified Shepard interpolation method. The ab initio calculations are performed at the CCSD(T) level. Taking account of the contribution of inner core electrons to electronic correlation interaction in ab initio electronic structure calculations, modified optimized aug-cc-pCVQZ basis sets are applied to the all-electrons calculations. On this potential energy surface, the triplet oxygen atom attacks methane in a near-collinear H–CH3 direction to form a saddle point with barrier height of 13.55 kcal/mol, which plays a key role in the kinetics of the title reaction. For the temperature range of 298–2500 K, our calculated thermal rate constants for the O(3P) + CH4 → OH + CH3 reaction show good agreement with relevant experimental data. This work provides detailed mechanism of this gas-phase reaction and a theoretical guidance for methane combustion. [ABSTRACT FROM AUTHOR]

This paper is focused on the gas properties over a cylinder from continuum to rarefied regimes based on the non-Newtonian constitutive model. This new constitutive model is first derived from Eu's nonequilibrium ensemble method, which is intended for accurate description of nonequilibrium flows. Some assumptions and simplifications are made during the establishing progress of the new constitutive model by both Eu and Myong. To verify its accuracy, temperature contours and skin frictions around the cylinder are simulated by this new model. The inflow Mach number is equal to 10 and the Knudsen number ranges from 0.002 to 0.05. All simulation results are compared with Navier–Stokes (NS) and the direct simulation Monte Carlo (DSMC) methods in detail. The comparisons of friction around the surface show that the non-Newtonian constitutive models are better than the linear constitutive relations of NS equations for the prediction of nonequilibrium flow and much more close to DSMC simulation results. [ABSTRACT FROM AUTHOR]

Summary: This paper studies the decentralized event‐triggered control of large‐scale nonlinear systems. We consider a class of decentralized control systems that are transformable into an interconnection of input‐to‐state stable subsystems with the sampling errors as the inputs. The sampling events for each subsystem are triggered by a threshold signal, and the threshold signals for the subsystems are independent with each other for the decentralized implementation. By appropriately designing the event‐triggering mechanisms, it is shown that infinitely fast sampling can be avoided for each subsystem and asymptotic regulation is achievable for the large‐scale system. The proposed design is based on the ISS small‐gain arguments, and is validated by a benchmark example of controlling two coupled inverted pendulums. [ABSTRACT FROM AUTHOR]

Synthesizing 2D metal–organic frameworks (2D MOFs) in high yields and rational tailoring of the properties in a predictable manner for specific applications is extremely challenging. Now, a series of porphyrin‐based 2D lanthanide MOFs (Ln‐TCPP, Ln=Ce, Sm, Eu, Tb, Yb, TCPP=tetrakis(4‐carboxyphenyl) porphyrin) with different thickness were successfully prepared in a household microwave oven. The as‐prepared 2D Ln‐TCPP nanosheets showed thickness‐dependent photocatalytic performances towards photooxidation of 1,5‐dihydroxynaphthalene (1,5‐DHN) to synthesize juglone. Particularly, the Yb‐TCPP displayed outstanding photodynamic activity to generate O2− and 1O2. This work not only provides fundamental insights into structure designing and property tailoring of 2D MOFs nanosheets, but also pave a new way to improve the photocatalytic performance. [ABSTRACT FROM AUTHOR]

Synthesizing 2D metal–organic frameworks (2D MOFs) in high yields and rational tailoring of the properties in a predictable manner for specific applications is extremely challenging. Now, a series of porphyrin‐based 2D lanthanide MOFs (Ln‐TCPP, Ln=Ce, Sm, Eu, Tb, Yb, TCPP=tetrakis(4‐carboxyphenyl) porphyrin) with different thickness were successfully prepared in a household microwave oven. The as‐prepared 2D Ln‐TCPP nanosheets showed thickness‐dependent photocatalytic performances towards photooxidation of 1,5‐dihydroxynaphthalene (1,5‐DHN) to synthesize juglone. Particularly, the Yb‐TCPP displayed outstanding photodynamic activity to generate O2− and 1O2. This work not only provides fundamental insights into structure designing and property tailoring of 2D MOFs nanosheets, but also pave a new way to improve the photocatalytic performance. [ABSTRACT FROM AUTHOR]

Phosphatidylserine (PS), a negatively charged phospholipid present predominantly at the inner leaflet of the plasma membrane, has been widely implicated in many cellular processes including membrane trafficking. Along this line, PS has been demonstrated to be important for endocytosis, however, the involved mechanisms remain uncertain. By monitoring clathrin‐mediated endocytosis (CME) of single vesicles in mouse chromaffin cells using cell‐attached capacitance measurements that offer millisecond time resolution, we demonstrate in the present study that the fission‐pore duration is reduced by PS addition, indicating a stimulatory role of PS in regulating the dynamics of vesicle fission during CME. Furthermore, our results show that the PS‐mediated effect on the fission‐pore duration is Ca2+‐dependent and abolished in the absence of synaptotagmin 1 (Syt1), implying that Syt1 is necessary for the stimulatory role of PS in vesicle fission during CME. Consistently, a Syt1 mutant with a defective PS–Syt1 interaction increases the fission‐pore duration. Taken together, our study suggests that PS–Syt1 interaction may be critical in regulating fission dynamics during CME. [ABSTRACT FROM AUTHOR]

Sphingosine‐1‐phosphate (S1P) is an essential bioactive sphingosine lipid involved in many neurological disorders. Sphingosine kinase 1 (SphK1), a key enzyme for S1P production, is concentrated in presynaptic terminals. However, the role of S1P/SphK1 signaling in exocytosis remains elusive. By detecting catecholamine release from single vesicles in chromaffin cells, we show that a dominant negative SphK1 (SphK1DN) reduces the number of amperometric spikes and increases the duration of foot, which reflects release through a fusion pore, implying critical roles for S1P in regulating the rate of exocytosis and fusion pore expansion. Similar phenotypes were observed in chromaffin cells obtained from SphK1 knockout mice compared to those from wild‐type mice. In addition, extracellular S1P treatment increased the number of amperometric spikes, and this increase, in turn, was inhibited by a selective S1P3 receptor blocker, suggesting extracellular S1P may regulate the rate of exocytosis via activation of S1P3. Furthermore, intracellular S1P application induced a decrease in foot duration of amperometric spikes in control cells, indicating intracellular S1P may regulate fusion pore expansion during exocytosis. Taken together, our study represents the first demonstration that S1P regulates exocytosis through distinct mechanisms: extracellular S1P may modulate the rate of exocytosis via activation of S1P receptors while intracellular S1P may directly control fusion pore expansion during exocytosis. Open science badges: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. [ABSTRACT FROM AUTHOR]

The continuous finite-time stabilization of a broad class of lower-triangular nonlinear systems using output feedback is studied in this paper. The nonlinearities are only assumed to be Hölder continuous. A constructive, continuous, finite-time, output-feedback stabilizer design is proposed based on a finite-time observer. Rigorous finite-time stability analysis is carried out for the closed-loop observer-controller system. The proposed design method is applied to a single-link robotic manipulator coupled to a dc motor. [ABSTRACT FROM AUTHOR]

Drug delivery by acoustic waves is a crucial technology for targeted therapy. Recently, a three-layered drug micro-particle was proposed and fabricated, the second shell of which greatly improves both the encapsulation of the drug and the flexibility in its release rate. In this work, the acoustic radiation force (ARF) of an acoustic focused Gaussian beam on a three-layered particle comprising an inner drug core (D), a middle layer of poly(lactide-co-glycolide) (PLGA), and an outer chitosan shell (CS) is investigated. A three-layered elastic shell (TES) mimics the D–PLGA–CS structure, and the acoustic scattering from and ARF of the D–PLGA–CS are studied using Mie theory. This paper focuses on how the geometry and acoustic parameters of the outer shell influence the ARF, finding that the Poisson's ratio of the outer shell affects the ARF more than does the density or Young's modulus. In addition, this paper finds that the choice of the inner drug has little effect on the ARF acting on the D–PLGA–CS particle. The present work may benefit the acoustic manipulation of both TESs and three-layered drugs. [ABSTRACT FROM AUTHOR]

Abstract Eleven undescribed ent -kauranes, named agallochanins A–K, were isolated from the stems and twigs of the Chinese semi-mangrove plant, Excoecaria agallocha L.. The absolute configurations of these diterpenoid compounds, except for the chirality of C-4 in agallochanin H, were unequivocally determined by HR-ESIMS, extensive NMR investigations, single-crystal X-ray diffraction analyses with Cu Kα radiation, quantum-chemical electronic circular dichroism (ECD) calculations, the comparison of experimental ECD spectra, and the modified Mosher's α -methoxy- α -(trifluoromethyl)phenylacetyl (MTPA) ester method. Agallochanins A–I are 3,4- seco - ent -kauranes. Agallochanin D represents the first example of 3,4- seco -17-nor- ent -kaurane. Agallochanin K exhibited NF-κB inhibitory activity with the inhibition rate of 79.6% at the concentration of 100.0 μM. Graphical abstract Eleven undescribed ent -kauranes, named agallochanins A–K, were isolated and identified. Agallochanin K exhibited NF-κB inhibitory activity. Unlabelled Image [ABSTRACT FROM AUTHOR]

The five-axis machine tool has been extensively employed in complex curved surface machining area. The linkage performance of the machine tool is one of the key origins of the machining accuracy. An accuracy measurement based on RTCP (rotation tool center point) is an effective means for multi-axes motion synchronously linkage performance detection. In order to demonstrate the linkage performance more completely, an RTCP trajectory description method is presented, and some trajectories which take account of curvature and speed changes are proposed in this paper. The trajectory sensitivity analysis is applied to examine the sensitivity of RTCP measuring trajectories in mismatch parameters of the five-axis machine tool. Through comparative analysis, some RTCP measuring trajectories are more sensitive to certain error parameters than others. Therefore, the corresponding RTCP measuring trajectories are necessary for various linkage performances detection of the five-axis machine tool. For this purpose, RTCP measuring trajectory is optimized based on sensitivity analysis result. Finally, linkage performance detection experiments based on RTCP are conducted, and the tool tip errors vary for the different linkage performance and different RTCP trajectories, which is consistent with trajectory sensitivity analysis results. These results indicate that the corresponding RTCP measuring trajectories are necessary for various linkage performance detections. Therefore, the RTCP trajectory that is more favourable to detection could be put forward according to the requirements of the five-axis machine tool. Furthermore, series of RTCP trajectories can be combined to exhibit the linkage performance of five-axis machine tools more comprehensively. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Triple-layered HAp/Al 2 O 3 /TiO 2 coatings were synthesized via RF magnetron sputtering method. • Biocompatibility and corrosion resistance features of HAp coatings were studied. • XRD, SEM, XPS, and EIS methods were employed for the characterizations of HAp coatings. • Biocompatibility and corrosion performances before and after immersion in simulated body fluid (SBF) solution were analysed. • Deconvolution of XPS spectra provide us with surface chemical bonding states of triple-layered HAp/Al 2 O 3 /TiO 2 coatings. Abstract Triple-layered RF magnetron sputtered HAp/Al 2 O 3 /TiO 2 coatings synthesized onto Ti-6Al-4V alloys were studied to improve the surface biocompatibility and corrosion resistance features. It was seen that the HAp layers played a substantial role in the biocompatibility, while the intermediate Al 2 O 3 /TiO 2 layers were used to enhance the corrosion behavior of the substrate. XRD results showed an enhanced crystallinity along with the (2 1 1) HAp phase after the simulated body fluid (SBF) immersion experiment. Local electronic and chemical bonding states of atomic phosphorus and calcium phosphate groups in the coatings, before and after immersion process, were confirmed via XPS studies. The electrochemical impedance spectroscopy (EIS) evaluated the corrosion, which indicated a reduction in capacitance values and a significant improvement of the corrosion resistance of such coatings; with improved bio-medical properties of Ti alloys. [ABSTRACT FROM AUTHOR]

The influence of the reaction gas composition during the DC magnetron sputtering process on the structural, chemical and optical properties of Ce-oxide thin films was investigated. X-ray diffraction (XRD) studies confirmed that all thin films exhibited a polycrystalline character with cubic fluorite structure for cerium dioxide. X-ray photoelectron spectroscopy (XPS) analyses revealed that cerium is present in two oxidation states, namely as CeO 2 and Ce 2 O 3 , at the surface of the films prepared at oxygen/argon flow ratios between 0% and 7%, whereas the films are completely oxidized into CeO 2 as the aforementioned ratio increases beyond 14%. Various optical parameters for the thin films (including an optical band gap in the range of 2.25–3.1 eV) were derived from the UV–Vis reflectance. A significant change in the band gap was observed as oxygen/argon flow ratio was raised from 7% to 14% and this finding is consistent with the high-resolution XPS analysis of Ce 3d that reports a mixture of Ce 2 O 3 and CeO 2 in the films. Density functional theory (DFT+U) implemented in the Cambridge Serial Total Energy Package (CASTEP) was carried out to simulate the optical constants of CeO 2 clusters at ground state. The computed electronic density of states (DOSs) of the optimized unit cell of CeO 2 yields a band gap that agrees well with the experimentally measured optical band gap. The simulated and measured absorption coefficient ( α ) exhibited a similar trend and, to some extent, have similar values in the wavelength range from 100 to 2500 nm. The combined results of this study demonstrate good correlation between the theoretical and experimental findings. [ABSTRACT FROM AUTHOR]

Abstract Nine new ent -abietanes, named decandrols A–I (1 – 9), which could be categorized into three groups (1 , 2 – 6 , 7 – 9), were isolated from the roots of an Indian mangrove, Ceriops decandra , collected in the swamp of Godavari estuary, Andhra Pradesh, together with six previously reported abietanes (10 – 15), of which the absolute configurations were first determined. The relative and absolute configurations of these compounds were unambiguously established by HR-ESIMS, extensive 1D and 2D NMR investigations, single-crystal X-ray diffraction analysis with Cu K α radiation, and quantum-chemical electronic circular dichroism (ECD) calculations. Decandrol A (1) is a rare C 9 -spirofused 7,8- seco - ent -abietane, whereas 2 – 15 are typically tricyclic ent -abietanes. Decandrols C (3) and E (5) exhibited significant NF-κB inhibitory activity at the concentration of 100 μM. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

The finite-time stabilization of a general class of lower-triangular nonlinear systems using output feedback is addressed in this paper. The system nonlinearities are only required to be Hölder continuous with output-dependent Hölder coefficients. A new constructive output-feedback, finite-time controller design is proposed based on a finite-time observer. Rigorous finite-time stability analysis is given for the closed-loop observer–controller system. A practical example of controlling a robotic model is adopted to illustrate the proposed method. [ABSTRACT FROM AUTHOR]

Abstract Development of advanced electrocatalysts to drive efficient hydrogen evolution reaction through water splitting is vital in many energy related technologies. Herein the development of nitrogen-doped carbon supported fewer-layer MoSe 2 (FL-MoSe 2 /NC) through calcining the hydrothermal product of the Se and Mo precursors in the presence of ammonium citrate is reported. This FL-MoSe 2 /NC is highly efficient for the hydrogen evolution reaction (HER) and exhibits a remarkably low onset potential of 15.2 mV, an extremely small overpotential of 74.6 mV (vs. RHE) at 10 mA cm−2, a greatly reduced Tafel slope of 45.2 mV dec−1, and a higher exchange current density of 0.266 mA cm−2. The performance of the FL-MoSe 2 /NC is much higher than that of most Mo-based HER electrocatalysts reported to date and even comparable to that of other most active non-precious metal based catalysts, suggesting the great potential of using the FL-MoSe 2 /NC as an efficient catalyst for the HER. The NC is believed to play an important role in the high performance of the FL-MoSe 2 /NC. It does not only promote a strong interaction between MoSe 2 and the NC, but facilitates the formation of MoSe 2 with few layers and shorter lattice fringe lengths, which expose more active sites accessible to the HER. Graphical abstract Nitrogen-doped carbon supported fewer-layer MoSe 2 (FL-MoSe 2 /NC) is demonstrated to be an efficient catalyst for the HER. The NC plays an important role in the high performance of the FL-MoSe 2 /NC. It facilitates the formation of MoSe 2 with few layers and shorter lattice fringe lengths and the exposure of more active sites to the HER. Image 1 Highlights • Nitrogen-doped carbon supported few-layer MoSe 2 (FL-MoSe 2 /NC) is prepared. • It exhibits low onset potential and small overpotential. • It exhibits a greatly reduced Tafel slope and a higher exchange current density. • MoSe 2 with few-layers and short fringe lengths exposes more edge and defect sites. • There exists a strong coupling between MoSe 2 and NC. [ABSTRACT FROM AUTHOR]

We demonstrate the regulation of metal-support interactions (MSI) by impregnating Co(NO 3 ) 2 as a precursor of cobalt over the silica coated with different amounts of amorphous carbon via carbonizing the glucose as a precursor in the inert atmosphere of an Ar. The materials were characterized by XRD, H 2 -TPR, H 2 -TPD, XPS, O 2 titration, and N 2 adsorption-desorption at low temperatures. In comparison with the parent 10 wt% Co/SiO 2 , the Co-supported carbon-coated SiO 2 (10 wt% Co/xC-SiO 2 ) showed obviously higher dispersion of the metallic cobalt (Co 0 ) and smaller Co 0 particle size. Moreover, the Co 0 dispersion was increased and the Co 0 particle size was decreased with increasing the carbon content over the catalysts. The weakened MSI between Co 0 and the xC-SiO 2 , the extent of which is dependent on the carbon content, was clearly revealed from the characterization results. This was further supported by the reaction results of Fischer-Tropsch synthesis (FT), and the highest CO conversion was obtained over 10 wt% Co/1C-SiO 2 . The simple procedure and the cheap glucose make it important for developing a more efficient FT catalyst. [ABSTRACT FROM AUTHOR]

A series of bimetallic lanthanide metal-organic frameworks (Ln-MOFs), namely Tb x /Eu 1−x -BTC, were prepared by wet grinding with a green and facile process. The as-prepared Tb x /Eu 1−x -BTC showed an adjustable dual emission performance for dipicolinic acid (DPA, Bacillus anthracis biomarker) ratiometric sensing. The highly efficient energy transfer from Tb3+ to Eu3+ endowed the strong red emission at 616 nm, even in Tb x /Eu 1−x -BTC with high proportion of Tb3+. Meanwhile, the energy transfer between Tb3+ and Eu3+ nodes could be blocked by the introduced DPA, showing a strong green emission at 544 nm, and thus resulting in a ratiometric fluorescence response. As a novel ratiometric fluorescence probe, the Tb 0.4 /Eu 0.6 -BTC exhibited an excellent linearity with DPA concentrations from 50 nM to 3 μM with high selectivity and low detection limit of 4.9 nM. The present work not only provided a green efficient method for the construction of bimetallic MOFs, but also proposed a new insight for designing fluorescence sensor with remarkable sensing performance. [Display omitted] • Wet grinding for the green synthesis of bimetallic lanthanide metal-organic frameworks. • Multicolor tunable lanthanide fluorescent probe. • DPA ratio sensing based on energy transfer regulation. • A powerful solution for monitoring Bacillus anthracis contamination. [ABSTRACT FROM AUTHOR]

Abstract This paper provides a personal account of the small-gain theory as a tool for stability analysis, control synthesis, and robustness analysis for interconnected uncertain systems. A milestone in modern control theory is the development of a transformative stability criterion known as the classical small-gain theorem proposed by George Zames in 1966, that surpasses Lyapunov theory in that there is no need to construct Lyapunov functions for the finite-gain stability of feedback systems. Under the small-gain framework, a feedback system composed of two finite-gain stable subsystems remains finite-gain stable if the loop gain is less than one. Despite its apparent simplicity at first sight, Zames's small-gain theorem plays a crucial role in the development of linear robust control theory. Borrowing techniques in modern nonlinear control, especially Sontag's notion of input-to-state stability (ISS), the first generalized, nonlinear ISS small-gain theorem proposed by one of the authors in 1994 overcomes the two shortcomings of Zames's small-gain theorem. First, the use of nonlinear gains allows to consider strongly nonlinear, interconnected systems. Second, the role of initial conditions is made explicit so that both internal Lyapunov stability and external input-output stability can be studied in a unified framework. In this survey paper, we first review early developments in the nonlinear small-gain theory for interconnected systems of various types such as continuous-time systems, discrete-time systems, hybrid systems and time-delay systems, along with applications in robust nonlinear control. Then, we describe how to obtain a network small-gain theory for large-scale dynamical networks that are comprised of more than two interacting nonlinear systems. Constructive methods for the generation of Lyapunov functions for the total network are presented as well. Finally, this paper discusses how the network/nonlinear small-gain theory can be applied to obtain innovative solutions to quantized and event-based nonlinear control problems, that are important for the development of a complete theory of controlling cyber-physical systems subject to communications and computation constraints. [ABSTRACT FROM AUTHOR]

Cascade phenomenon may lead to catastrophic disasters which extremely imperil the network safety or security in various complex systems such as communication networks, power grids, social networks and so on. In some flow-based networks, the load of failed nodes can be redistributed locally to their neighboring nodes to maximally preserve the traffic oscillations or large-scale cascading failures. However, in such local flow redistribution model, a small set of key nodes attacked subsequently can result in network collapse. Then it is a critical problem to effectively find the set of key nodes in the network. To our best knowledge, this work is the first to study this problem comprehensively. We first introduce the extra capacity for every node to put up with flow fluctuations from neighbors, and two extra capacity distributions including degree based distribution and average distribution are employed. Four heuristic key nodes discovering methods including High-Degree-First (HDF), Low-Degree-First (LDF), Random and Greedy Algorithms (GA) are presented. Extensive simulations are realized in both scale-free networks and random networks. The results show that the greedy algorithm can efficiently find the set of key nodes in both scale-free and random networks. Our work studies network robustness against cascading failures from a very novel perspective, and methods and results are very useful for network robustness evaluations and protections. [ABSTRACT FROM AUTHOR]

This paper provides a novel non-model-based, data-driven stochastic H ∞ control design for linear continuous-time stochastic interconnected systems with unknown dynamics. Our contributions are three-fold. First, we develop a tool to show how to assign an arbitrarily small input-to-output stochastic L 2 gain of the closed-loop system, by combining the gain assignment technique with the zero-sum dynamic game-based H ∞ control design. Second, robustness to dynamic uncertainties is tackled using the small-gain theory. Third, we develop a non-model-based stochastic robust adaptive dynamic programming (RADP) algorithm for adaptive optimal controller design. In sharp contrast to the existing methods, the obtained algorithm is based on value iteration (VI), and the knowledge of an initial stabilizing control policy is no longer needed. An example of a power electronic system is adopted to illustrate the obtained results. [ABSTRACT FROM AUTHOR]