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Tunnel lining falling blocks can cause great threats to traffic safety, resulting in traffic interruptions or speed limits and endangering operational safety. Traditional lining disease remediation measures have low efficiency and high costs and are time consuming. Combining the research methods used in the literature, indoor testing, and model experiments, a very normal material, namely, polyurea spray film material, is proposed as a means by which to remediate the lining falling block disease in tunnels. A 1 : 1 tunnel lining structure model was established at the site, and four experimental conditions were tested. The experiments revealed that the tensile stress was less than the tensile strength and that no tensile fracture occurred in the polyurea spray film material under the joint action of the block’s self-weight and aerodynamic loads. Factors such as side seam treatment, surface sanding, and spray temperature may influence the bond strength of the polyurea spray film material. In order to remediate the issue of lining blocks falling, we recommended increasing the bond strength between the spray film material and the concrete or increasing the thickness of the polyurea spray film material.

AIE-featured PEG-condensed Cu(i)-p-MBA aggregates (PCuA), showing enhanced photodynamic antibacterial activities, were developed in water.

A theranostic probe was developed by conjugating NIR-II emitting Au44MBA26 nanoclusters with photothermal Cy7 molecules via click chemistry, achieving NIR-II luminescent and photoacoustic imaging-guided cancer photothermal therapy.

Composite sandwich plates and beams are increasingly employed as an engineering material in structures such as airplanes, ships, bridges, and vehicles because of their superb strength to weight ratio. Understanding a sandwich structure’s failure mechanism is a prerequisite for a safety design. In this paper, we employ a new experimental technique called DVSP (Digital Volumetric Speckle Photography) to map the interior deformation of a short composite sandwich beam under three-point bending. 3D displacement fields and shear strain fields of 5 transverse and 4 longitudinal sections of the beam are mapped quantitatively in detail as a function of increasing load. The beam fails in delamination of the interface between the face sheet and core.

The concept of acute aortic syndrome (AAS) facilitates the early identification of patients with chest pain caused by an aortic condition, and expedites risk stratification and definitive treatment. Important differential diagnoses are acute coronary syndrome, pulmonary embolism and chest pain from trauma. Individuals with AAS should be evaluated using a combination of blood tests, electrocardiography and imaging, such as computed tomography CT or echocardiography initially, and magnetic resonance imaging at a later stage. Classic aortic dissection is the most common form of AAS. Risk factors include congenital factors such as hereditary connective tissue disorders, bicuspid aortic valve with aortopathy and, most importantly, acquired conditions such as untreated hypertension. Patients with evidence of rupture of one aortic layer, malperfusion syndrome or end-organ ischaemia require urgent intervention; in cases of proximal dissection including the arch this is typically open surgery, and in distal or type B dissection it is usually endovascular stent-graft placement with ancillary procedures. The optimal management of patients with AAS is challenging and requires a multidisciplinary team approach. Further studies are required to fully characterize conditions within the AAS spectrum and to offer an individualized, patient-centred treatment.

Small interfering RNAs (siRNAs) are the key components for RNA interference (RNAi), a conserved RNA-silencing mechanism in many eukaryotes1,2. In Drosophila, an RNase III enzyme Dicer-2 (Dcr-2), aided by its cofactor Loquacious-PD (Loqs-PD), has an important role in generating 21 bp siRNA duplexes from long double-stranded RNAs (dsRNAs)3,4. ATP hydrolysis by the helicase domain of Dcr-2 is critical to the successful processing of a long dsRNA into consecutive siRNA duplexes5,6. Here we report the cryo-electron microscopy structures of Dcr-2–Loqs-PD in the apo state and in multiple states in which it is processing a 50 bp dsRNA substrate. The structures elucidated interactions between Dcr-2 and Loqs-PD, and substantial conformational changes of Dcr-2 during a dsRNA-processing cycle. The N-terminal helicase and domain of unknown function 283 (DUF283) domains undergo conformational changes after initial dsRNA binding, forming an ATP-binding pocket and a 5′-phosphate-binding pocket. The overall conformation of Dcr-2–Loqs-PD is relatively rigid during translocating along the dsRNA in the presence of ATP, whereas the interactions between the DUF283 and RIIIDb domains prevent non-specific cleavage during translocation by blocking the access of dsRNA to the RNase active centre. Additional ATP-dependent conformational changes are required to form an active dicing state and precisely cleave the dsRNA into a 21 bp siRNA duplex as confirmed by the structure in the post-dicing state. Collectively, this study revealed the molecular mechanism for the full cycle of ATP-dependent dsRNA processing by Dcr-2–Loqs-PD.

The end-Permian mass extinction (EPME) was known as the most severe biocrisis of the past 600 Ma. In order to explore the redox state of deep water environments, and the causal relationship between anoxia/euxinia and the EPME, this study selected the Penglaitan section in Guangxi, China, and measured the iron speciation and concentrations of trace elements and major elements. Several redox proxy approaches, including both iron speciation proxies and the excess fractions and enrichment factors of redox sensitive elements (RSEs), indicate that anoxia in the Penglaitan depositional environment was sporadic, with the majority of the section deposited under oxic conditions. This includes the interval immediately prior to and during the EPME; euxinia did not occur at the Penglaitan section around the EPME. Thus, anoxia was not the primary driver for the EPME at the Penglaitan section, and the accumulation of free H2S in the oceanic water-column could not have been the only proximal kill mechanism for the EPME at the Penglaitan section.

Capacitive deionization (CDI), as a novel, energy-efficient, and environment-friendly desalination technology, has received substantial attention in the scientific community during the last five decades, while the electrode materials, acting as the ion storage media, play a vital role during its desalination process. Meanwhile, developing electrode materials from biomass has been proven to be a feasible strategy due to their abundance in nature, unique microstructure, as well as feasibility for further modifications. In this review, various bio-mass-based electrode materials and their unique advantages as CDI electrodes are systematically presented.

Metal nanoclusters (NCs) have emerged as novel antibacterial agents featuring broad-spectrum antibacterial activity without drug resistance for bacteria, but suffer from fast antibacterial invalidation due to their consumption by bacteria. Herein we report the design of a visible-light-driven photodynamic antibacterial agent based on conjugating aggregation-induced emission (AIE)-featured AuAg NCs with highly luminescent carbon dots (CDs). The conjugation of CDs with AuAg NCs could not only enhance the visible-light harvest, but also promote charge carrier generation/separation

A molecular Au nanocluster (NC)-based photocatalyst was developed by chemically grafting the three-in-one function of Co-TCPP molecules for improved photocatalytic H2O2 production.

Electromagnetic topological edge states typically are created in photonic systems with crystalline symmetry and these states emerge because of the topological feature of bulk Bloch bands in momentum space according to the bulk-edge correspondence principle. In this work, we demonstrate the existence of chiral topological electromagnetic edge states in Penrose-tiled photonic quasicrystals made of magneto-optical materials, without relying on the concept of bulk Bloch bands in momentum space. Despite the absence of bulk Bloch bands, which naturally defiles the conventional definition of topological invariants in momentum space characterizing these states, such as the Chern number, we show that some bandgaps in these photonic quasicrystals still could host unidirectional topological electromagnetic edge states immune to backscattering in both cylinders-in-air and holes-in-slab configurations. Employing a real-space topological invariant based on the Bott index, our calculations reveal that the bandgaps hosting these chiral topological edge states possess a nontrivial Bott index of $\pm 1$, depending on the direction of the external magnetic field. Our work opens the door to the study of topological states in photonic quasicrystals., Comment: 4 pages, 4 figures