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A key barrier to the development of vaccines that induce broadly neutralizing antibodies (bnAbs) against human immunodeficiency virus (HIV) and other viruses of high antigenic diversity is the design of priming immunogens that induce rare bnAb-precursor B cells. The high neutralization breadth of the HIV bnAb 10E8 makes elicitation of 10E8-class bnAbs desirable; however, the recessed epitope within gp41 makes envelope trimers poor priming immunogens and requires that 10E8-class bnAbs possess a long heavy chain complementarity determining region 3 (HCDR3) with a specific binding motif. We developed germline-targeting epitope scaffolds with affinity for 10E8-class precursors and engineered nanoparticles for multivalent display. Scaffolds exhibited epitope structural mimicry and bound bnAb-precursor human naive B cells in ex vivo screens, protein nanoparticles induced bnAb-precursor responses in stringent mouse models and rhesus macaques, and mRNA-encoded nanoparticles triggered similar responses in mice. Thus, germline-targeting epitope scaffold nanoparticles can elicit rare bnAb-precursor B cells with predefined binding specificities and HCDR3 features.

Recyclable elastomers based on adaptable covalent networks fabricated via different types of dynamic bonds have been designed and prepared to resolve the urgent problems generated by waste elastomers. However, due to inevitable side reactions during thermal recycling (e.g., oxidation, permanent cross-linking), mechanical recovery efficiency after thermal recycling is normally <90% for most recyclable elastomers, making it difficult to achieve comparable performance. Herein, we report a novel semi-interpenetrating network design that achieves mechanical reinforcement after thermal recycling via network topology isomerization and formation of new cross-linking points. The designed semi-interpenetrating network includes an aromatic disulfide bond-containing polyurethane network and long linear polyurethane chains with side-chain vinyl groups. Triggered by heat during reprocessing, the disulfide bonds inside the cross-linked network break and the generated phenyl sulfur radicals undergo thiol–ene reactions with the side-chain vinyl groups in the linear polyurethane chains, resulting in increased cross-linking density. Electron paramagnetic resonance testing, in situFourier transform infrared spectrometry, high-temperature stress relaxation testing, and cross-linking density measurements were utilized to monitor the process. The tensile strength and extensibility recycling efficiencies reached 186 and 131% of original values after reprocessing twice, realizing mechanical reinforcement after thermal recycling. Interestingly, based on a similar mechanism, mechanical fatigue after repeated stretch and release cycles was efficiently eliminated upon thermal treatment. Such a strategy achieving polymer design with reinforced physical properties after recycling will benefit practical applications of sustainable elastomers and other thermosetting materials.

The experimental study on aramid fiber-reinforced composites (AFRP) was carried out. The milling experiments of AFRP were carried out from different fiber orientations. The changes in surface quality, fiber section, and chip shape in mPIC1195147illing under different fiber orientations were studied, and the action law of the blade and tooth was analyzed from the micro perspective. The response surface are used to analyze the cutting force. The mathematical model is established to predict the minimum cutting force. The variance analysis method is used to analyze the influencing factors and their weights of cutting force. The research shows that the cutting force is the smallest when the fiber orientation angle is 0° or 90°, the milling surface quality is good, and the chips are primarily powdery. The cutting force is the largest when the fiber orientation angle is 45° and the milling surface quality is poor. The chips are mainly flocculent. At this angle, the cutting force is affected by three factors, and the interaction has the most significant proportion. When the fiber orientation angle is 30° or 60°, the cutting force, the fiber cross-section, and the surface quality are between the former two, and most of the chips are mixed chips (powdery and flocculent). The evolution and distribution law of burr is obtained. During AFRP milling, the milling surface is always sheared on one side and accompanied by extrusion. The fibers are sheared and broken, the surface burrs are few, the side is stretched, the fibers are stretched and broken, and the surface burrs are many. The action rule of the cutting tool on transverse and longitudinal fibers is summarized.

Conductive fillers are critical raw materials for many applications. However, vulnerability to salt spray corrosion remains the biggest problem for silver-plated conductive fillers. Herein, highly conductive silver-plated carbon fiber powders (Ag/pCF) were prepared via catechol/polyamine activation and subsequently formed a tannic acid/metal ion (TA@Me) complex inhibition layer. The electromagnetic interference (EMI) shielding effectiveness of the composite fabricated with original Ag/pCF decreased from 106.4 to 90.4 dB after a 4-cycle salt spray corrosion test, while the composites protected by TA@Me remained unchanged above 110 dB. Further research revealed that TA@Me could effectively block the penetration of Cl–, which is the primary corrosive chemical in a salt fog environment. Considering the high conductivity and the excellent antisalt spray performance, the Ag/pCF protected by the efficient TA@Me inhibition layer via an eco-friendly approach will be a priority alternative for high-performance EMI-shielding applications.

A decoupled plasma nitridation (DPN)/postnitridation annealing (PNA) process scheme to reduce the metal boundary effect (MBE) was experimentally demonstrated using a 28-nm high- $k$ first/gate last process platform. Through extensive physical and electrical characterization, it was found that the main reason for the MBE effect could be the lateral diffusion of aluminum through the HK layer. The DPN/PNA treatment process was found to improve the nitrogen distribution in the HK layer and enhance its diffusion barrier properties. Consequently, the MBE-induced ${}V_{\text{t}}$ shift was successfully suppressed in pFETs that were particularly susceptible to the MBE effect. Additionally, the proposed solution led to an increased static noise margin (SNM) of a specially designed tightly spaced SRAM. This outcome not only validates the effectiveness of the proposed approach, but also demonstrates its value for future SRAM scaling in advanced nodes.

Decorating the backbone of dielectric elastomers (DEs) with polar functionalities is an important practice that increases the total charge quantity of the chain segments, allowing DEs to have high dielectric permittivity (ε′). However, most established methods have struggled with optimizing the electromechanical performance of DEs, as the interactions among their polar functionalities have inevitably deteriorated the network flexibility of DEs. Herein, we present an innovative design concept for homogeneous DEs with superior dielectric properties by incorporating angle-containing monomers as building blocks that enable a flexible “zigzag” chain configuration in the DEs. This configuration, in turn, facilitates the charge separation within the chain segments. Therefore, a substantial increase of ε′ (∼90%) can be achieved while reducing the corresponding Young’s modulus, enabling superior and dynamically stable actuation performance in DEs. These findings have the potential to break the longstanding trade-off between dielectric and mechanical performances of conventional DEs upon chemical decorations.

Background: Posthepatitic cirrhosis is one of the leading risk factors for hepatocellular carcinoma (HCC) worldwide, among which hepatitis B cirrhosis is the dominant one. This study explored whether laparoscopic splenectomy and azygoportal disconnection (LSD) can reduce the risk of HCC among patients with hepatitis B virus (HBV)-related cirrhotic portal hypertension (CPH). Methods: A total of 383 patients with HBV-related CPH diagnosed as gastroesophageal variceal bleeding and secondary hypersplenism were identified in our hepatobiliary pancreatic center between April 2012 and April 2022, and conducted an 11-year retrospective follow-up. We used inverse probability of treatment weighting (IPTW) to correct for potential confounders, weighted Kaplan–Meier curves, and logistic regression to estimate survival and risk differences. Results: Patients were divided into two groups based on treatment method: LSD (n= 230) and endoscopic therapy (ET; n= 153) groups. Whether it was processed through IPTW or not, LSD group showed a higher survival benefit than ET group according to Kaplan–Meier analysis (P&lt; 0.001). The incidence density of HCC was higher in the ET group compared to LSD group at the end of follow-up [32.1/1000 vs 8.0/1000 person-years; Rate ratio: 3.998, 95% confidence intervals (CI) 1.928–8.293]. Additionally, in logistic regression analyses weighted by IPTW, LSD was an independent protective predictor of HCC incidence compared to ET (odds ratio 0.516, 95% CI 0.343–0.776; P= 0.002). Conclusion: Considering the ability of LSD to improve postoperative survival and prevent HCC in HBV-related CPH patients with gastroesophageal variceal bleeding and secondary hypersplenism, it is worth promoting in the context of the shortage of liver donors. Graphical abstract:

Recently developed elastomers with an adaptable covalent network, e.g., elastic vitrimers, have great potential as sustainable materials, although most of them suffer from limited recyclability and unsatisfied mechanical properties. Here, we report a polydimethylsiloxane (PDMS)-based recyclable elastic network, combining permanent chemical and high-density dynamic physical crosslinks utilizing side-chain reactions, which provides energy dissipation for superb toughness and enables efficient chain rearrangement for excellent recyclability. The optimal elastic network achieves an unprecedented recyclability of 70 cycles, one order of magnitude higher than existing elastic vitrimers, extraordinary toughness of 66 MJ/m3, significantly higher than previously reported PDMS elastomers, excellent chemical resistance, and vitrimer-like rheological behavior. Physical analysis is also performed to provide the accurate estimation of bond-exchange dynamics excluding the often-neglected chain dynamics and to offer insight into the superb performance. We anticipate that such a design principle enables an alternative approach for developing superior recyclable polymer networks.

In this study, a hydrogenated nitrile rubber (HNBR)/tetrafluoroethylene, ethylene, and hexafluoropropylene terpolymer (EFEP) thermoplastic vulcanizate (TPV) is prepared by decreasing the cohesive energy density of HNBR, improving the compatibilization of two phases via dioctyl phthalate, and optimizing the cross-linking characteristics and the dynamic vulcanization process. The as-produced HNBR/EFEP TPV exhibits a fine dispersion of the HNBR phase within the EFEP matrix, resulting in good mechanical and rheological properties, high elasticity, excellent recyclability, high resistance to heat and oil, and good gas barrier properties. The morphological evolution of the HNBR/EFEP TPV indicates that the development of the microstructure is controlled by the in situ cross-linking and clustering of HNBR particles, with the subsequent breakup of the rubber particle aggregates. The enhancement of the compatibility of HNBR/EFEP and the effect of the shearing force led to a reduction in the size of HNBR particle agglomerates and an enhancement in the quantity of single HNBR particles during dynamic vulcanization.

Cascaded relativistic magnetron (CRM) is a novel design for relativistic magnetron (RM) with phase-locked microwave output. A cascaded phase-locking RM contains two slow wave structures (SWSs) and an axially extended coupling cavity, which was designed to obtain eight-way phase-locked microwave output. Simulations show that under 650-kV anode voltage and 0.59-T axial magnetic field, the CRM operated in $\pi $ -mode, the output signals fell into a phase-locked state in 14 ns, the power of each way is about 200 MW with 3.75-GHz frequency, and total power exceeded 1.5 GW under 5.5-kA anode voltage. In the serial cascaded configuration, the driven voltage is fed from the intersection of the anode, which obtains a 44% device efficiency.

Highly conductive fillers are an essential raw material in the fabrication of conductive composites, paste, ink, adhesive, etc. Still, susceptibility to salt spray erosion remains a serious issue for silver-based fillers. Herein, we first prepared highly conductive silver-plated microspherical silica (Ag/pSiO2) through catechol/polyamine surface functionalization and subsequently formed a self-assembled inhibition layer on the surface of Ag/pSiO2by using (3-mercaptopropyl)trimethoxysilane (KH590) to enhance the salt spray erosion resistance. The results suggested that the self-assembled KH590 greatly improved the salt spray erosion resistance of the Ag/pSiO2. The total shielding effectiveness (SEt) of the composites protected by KH590 was 106 dB after the salt spray erosion, which was even 16 dB higher than that before erosion. In contrast, the SEt of the composites without KH590 decreased significantly from 111 to 76 dB. Further studies revealed that the KH590 inhibitor strongly prevented the penetration of Cl–and subsequently enhanced the salt spray resistance. Considering the facile and effective preparation, this strategy could be applied in large-scale silver-based EMI shielding materials.

Superhydrophobic surfaces present promising potential for improving the mechanical and chemical durability of electromagnetic interference (EMI) shielding materials. However, integrating superhydrophobicity and EMI shielding is still a challenge due to the complex structural design. Herein, superhydrophobic and highly durable fabrics with excellent EMI shielding effectiveness were fabricated. First, the meta-aramid nonwoven fabrics were functionalized by a polydopamine layer. Then, with the assistance of the metal-binding ability of polydopamine, silver nanoparticles were immobilized on the fiber surface by electroless plating. Finally, after the introduction of fluorine-containing agents via a facile dipping method, a superhydrophobic surface was successfully obtained. The as-prepared fabrics showed excellent EMI shielding effectiveness of 111 dB due to superior electrical conductivity (234 S/cm). Moreover, thanks to the low surface energy of fluorine-containing molecules as well as the micro-nanoroughness created by the stacking of silver nanoparticles, the composite fabrics exhibited a large water contact angle of 152° and a low sliding angle of 5°. It was noted that the composite fabrics still maintain superhydrophobicity and high EMI shielding effectiveness (110 dB) even after the acid and alkali corrosion, bending, abrading, and salt fog test, respectively, demonstrating their durability under harsh environments.

Pharmacological manipulation of mGluR5 has showed that mGluR5 is implicated in the pathophysiology of anxiety and mGluR5 has been proposed as a potential drug target for anxiety disorders. Nevertheless, the mechanism underlying the mGluR5 involvement in stress-induced anxiety-like behavior remains largely unknown. Here, we found that chronic restraint stress induced anxiety-like behavior and decreased the expression of mGluR5 in hippocampal CA1. Specific knockdown of mGluR5 in hippocampal CA1 pyramidal neurons produced anxiety-like behavior. Furthermore, both chronic restraint stress and mGluR5 knockdown impaired inhibitory synaptic inputs in hippocampal CA1 pyramidal neurons. Notably, positive allosteric modulator of mGluR5 rescued stress-induced anxiety-like behavior and restored the inhibitory synaptic inputs. These findings point to an essential role for mGluR5 in hippocampal CA1 pyramidal neurons in mediating stress-induced anxiety-like behavior.

Lithium production in China mainly depends on hard rock lithium ores, which has a defect in resources, environment, and economy compared with extracting lithium from brine. This paper focuses on the research progress of extracting lithium from spodumene, lepidolite, petalite, and zinnwaldite by acid, alkali, salt roasting, and chlorination methods, and analyzes the resource intensity, environmental impact, and production cost of industrial lithium extraction from spodumene and lepidolite. It is found that the sulfuric acid method has a high lithium recovery rate, but with a complicated process and high energy consumption; alkali and chlorination methods can directly react with lithium ores, reducing energy consumption, but need to optimize reaction conditions and safety of equipment and operation; the salt roasting method has large material flux and high energy consumption, so require adjustment of sulfate ratio to increase the lithium yield and reduce production cost. Compared with extracting lithium from brine, extracting lithium from ores, calcination, roasting, purity, and other processes consume more resources and energy; and its environmental impact mainly comes from the pollutants discharged by fossil energy, 9.3–60.4 times that of lithium extracted from brine. The processing cost of lithium extraction from lepidolite by sulfate roasting method is higher than that from spodumene by sulfuric acid due to the consumption of high-value sulfate. However, the production costs of both are mainly affected by the price of lithium ores, which is less competitive than that of extracting lithium from brine. Thus, the process of extracting lithium from ores should develop appropriate technology, shorten the process flow, save resources and energy, and increase the recovery rate of related elements to reduce environmental impact and improve the added value of by-products and the economy of the process.

Established herein is a radical-mediated C–H alkylation of enamides with cyclopropanols. An environmentally benign catalytic system with iron salt and air is used to permit the oxidative coupling process. The protocol demonstrates a broad substrate scope, allowing the stereoselective synthesis of alkylated enamides. The value of this strategy is further reflected by late-stage diversification of complex cyclopropanol-containing molecules and downstream transformations. Mechanistic studies reveal the dual role of iron salt in the reaction.

Highly oxidized germacranolides are mainly found in the genus Elephantopus, contain a characteristic ten-membered molecular core that is highly flexible, and exhibit potential cytotoxic properties. However, their configurations were assigned ambiguously in previous reports due to spectroscopic observation of macrocyclic systems. Herein, 17 highly oxidized germacranolides, including 12 new germacranolides (1–12), were isolated from Elephantopus tomentosus. Their structures were characterized by spectroscopic data analysis combined with X-ray crystallography and ECD calculations, and it was possible to propose configurational revisions of five previously reported analogues (13–17). Cytotoxic activities for 1–17against two hepatocellular carcinoma cell lines (HepG2 and Hep3B) were tested, and compounds 1–10and 13–16generated IC50values of 2.2–9.8 μM. Furthermore, the observed cytotoxic activity of 1was determined as being mediated by inducing the apoptosis of HepG2 and Hep3B cells via mitochondrial dysfunction.

Documented cases of ipsilateral ptosis caused by midbrain infarction remain rare. Herein, we present a patient with isolated ipsilateral ptosis that was initially considered to be a consequence of myasthenia gravis but was subsequently attributed to ventral midbrain infarction. We also discuss the possible underlying mechanisms; ipsilateral ptosis in our patient was attributed to selective damage of the levator palpebral muscle branch of the oculomotor nerve. The patient was started on aspirin (200 mg once daily) and atorvastatin (40 mg once daily). Improvement in ptosis occurred from day 5 of admission, and the patient was subsequently discharged. Ptosis disappeared 1 month after onset. This report describes an extremely rare case of ventral midbrain infarction presenting with isolated ipsilateral ptosis. Careful examination, including magnetic resonance imaging, is essential in such patients, especially in those with multiple cerebrovascular risk factors.

Transition metal oxides are well-known catalysts for oxidative dehydrogenation thanks to their excellent ability to activate alkanes. However, they suffer from an inferior alkene yield due to the trade-off between the conversion and selectivity induced by more reactive alkenes than alkanes, which obscures the optimization of catalysts. Herein, we attempt to overcome this challenge by activating a selective main-group indium oxide considered to be inactive for oxidative dehydrogenation in conventional wisdom. Atomically dispersed In sites with the local structure of [InOH]2+anchored by substituting the protons of supercages in HY are enclosed to be active centers that enable the activation of ethane with a metal-normalized turnover number of almost one magnitude higher than those of their supported In2O3counterparts. Furthermore, the structure of isolated [InOH]2+sites could be stabilized by in situ formed H2O from the selective oxidation of hydrogen by In2O3nanoparticles. As a result, the as-designed main-group In catalysts exhibit 80% ethene selectivity at 80% ethane conversion, thus achieving 60% ethene yield due to active isolated [InOH]2+sites and selective In2O3nanoparticles, outperforming state-of-the-art transition metal oxide catalysts. This study unlocks new opportunities for the utilization of main-group elements and could pave the way toward a more rational design of catalysts for highly efficient selective oxidation catalysis.

•Some representative design ideas and methods for preparing DEA driven soft robots are described.•The configuration and performance requirements of DEA for various bioinspired robots are introduced.•Perspectives of research on developing new DEA materials and improving DEA performances are proposed.

ABSTRACTThis study compares the benefits, stakeholders, program implementation, and locations of community forestry (CF) programs in Taiwan and Indonesia based on expert views. An online survey was submitted to 49 experts between December 2019 and January 2020. We evaluated CF benefits, stakeholder roles, and available programs in both countries using the Friedman and Hollander–Wolfe tests. Concerning benefits, Taiwan and Indonesia differed considerably, in that environmental, economic, and social benefits of CF in Taiwan were all assigned equal values. However, in Indonesia, economic benefits (R = 55.0) had the highest score. Regarding stakeholders’ contributions, community organizations (R = 99.5) constituted the highest contribution in Taiwan, while the government (R = 79.5) was the dominant stakeholder in Indonesia. The government mostly contributed by providing financial support (R = 67.5) for community organization development in Taiwan, while in Indonesia, it focused on devolving forestland and forest resources (R = 61.0) to communities. The contributions of non-governmental organizations in facilitating CF were the same in Taiwan and Indonesia. In terms of the available programs, Taiwan and Indonesia also differed, indicated by the community participation motives that were equally important to increase income, protect forests, and conserve biodiversity and ecosystem in Taiwan, whereas in Indonesia, increasing income (R = 63.0) was the most important to communities. For community development programs, ecotourism (R = 51.5) is more influential than product industry development in Taiwan, while in Indonesia, they were equally influential. CF implementation in Taiwan was more likely located in mountainous areas, while CFs were situated throughout Indonesia.

Brain-inspired intelligent systems demand diverse neuromorphic devices beyond simple functionalities. Merging biomimetic sensing with weight-updating capabilities in artificial synaptic devices represents one of the key research focuses. Here, we report a multiresponsive synapse device that integrates synaptic and optical-sensing functions. The device adopts vertically stacked graphene/h-BN/WSe2heterostructures, including an ultrahigh-mobility readout layer, a weight-control layer, and a dual-stimuli-responsive layer. The unique structure endows synapse devices with excellent synaptic plasticity, short response time (3 μs), and excellent optical responsivity (105A/W). To demonstrate the application in neuromorphic computing, handwritten digit recognition was simulated based on an unsupervised spiking neural network (SNN) with a precision of 90.89%, well comparable with the state-of-the-art results. Furthermore, multiterminal neuromorphic devices are demonstrated to mimic dendritic integration and photoswitching logic. Different from other synaptic devices, the research work validates multifunctional integration in synaptic devices, supporting the potential fusion of sensing and self-learning in neuromorphic networks.

Thermoset elastomers are widely used in industry and frontier research due to their advantage of mechanical robustness, high thermal/chemical resistance, and good dimensional stability. However, the presence of permanent crosslinks in thermoset elastomers significantly limits their recyclability. Polymer networks with associative exchangeable crosslinkers, called vitrimers, are reported to provide a path to polymer circularity for traditional thermosets. Herein, we provide a review of representative studies dedicated to the design, synthesis, fundamental physics, and property evaluation of elastic vitrimers that are synthesized based on different types of dynamic covalent bonds. Control on the network parameters (e.g., type of chemical bond, crosslink density, polymer backbone, and network architecture) of the elastic vitrimers enables them to tailor their mechanical performance, network dynamics, self-healing capability, and recyclability. The dynamic nature of reversible chemical bonds allows controlling the responsive behavior of elastic vitrimers to a variety of external stimuli, such as temperature, light, and moisture. Special attention is paid to the critical physical parameters in elastic vitrimers, such as topology freezing temperature (Tv), and their comparison with those of widely used thermoset and thermoplastic elastomers. The merits, bottlenecks, and future research directions of elastic vitrimers are also discussed toward their practical applications in various fields.