A Semisynthetic Bioluminescence Sensor for Ratiometric Imaging of Metal Ions In Vivo Using DNAzymes Conjugated to An Engineered Nano-Luciferase

DNA-based probes have gained significant attention as versatile tools for biochemical analysis, benefiting from their programmability and biocompatibility. However, most existing DNA-based probes rely on fluorescence as the signal output, which can be problematic due to issues like autofluorescence and scattering when applied in complex biological materials such as living cells or tissues. Herein, we report the development of bioluminescent nucleic acid (bioLUNA) sensors that offer laser excitation-independent and ratiometric imaging of the target in vivo. The system is based on computational modelling and mutagenesis investigations of a genetic fusion between circular permutated Nano-luciferase (NLuc) and HaloTag, enabling the conjugation of the protein with a DNAzyme. In the presence of Zn²⁺, the DNAzyme sensor releases the fluorophore-labelled strand, leading to a reduction in bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. Consequently, this process induces ratiometric changes in the bioluminescent signal. We demonstrated that this bioLUNA sensor enabled imaging of both exogenous Zn²⁺ in vivo and endogenous Zn²⁺ efflux in normal epithelial prostate and prostate tumors. This work expands the DNAzyme sensors to using bioluminescence and thus has enriched the toolbox of nucleic acid sensors for a broad range of biomedical applications.     

Direct Visualization of Atomic Structure in Multivariate Metal-Organic Frameworks (MOFs) for Guiding Electrocatalysts Design

The direct utilization of metal–organic frameworks (MOFs) for electrocatalytic oxygen evolution reaction (OER) has attracted increasing interests. Herein, we employ the low-dose integrated differential phase contrast-scanning transmission electron microscopy (iDPC-STEM) technique to visualize the atomic structure of multivariate MOFs (MTV-MOFs) for guiding the structural design of bulk MOFs for efficient OER. The iDPC-STEM images revealed that incorporating Fe³⁺ or 2-aminoterephthalate (ATA) into Ni-BDC (BDC: benzenedicarboxylate) can introduce inhomogeneous lattice strain that weaken the coordination bonds, which can be selectively cleaved via a mild heat treatment to simultaneously generate coordinatively unsaturated metal sites, conductive Ni@C and hierarchical porous structure. Thus, excellent OER activity with current densities of 10 and 100 mA cm⁻² are achieved over the defective MOFs at small overpotentials of 286 mV and 365 mV, respectively, which is superior to the commercial RuO₂ catalyst and most of the bulk MOFs.     

Fluorine-Boosted Kinetic and Selective Molecular Sieving of C6 Derivatives

Porous molecular sorbents have excellent selectivity towards hydrocarbon separation with energy saving techniques. However, to realize commercialization, molecular sieving processes should be faster and more efficient compared to extended frameworks. In this work, we show that utilizing fluorine to improve the hydrophobic profile of leaning pillararenes affords a substantial kinetic selective adsorption of benzene over cyclohexane (20 : 1 for benzene). The crystal structure shows a porous macrocycle that acts as a perfect match for benzene in both the intrinsic and extrinsic cavities with strong interactions in the solid state. The fluorinated leaning pillararene surpasses all reported organic molecular sieves and is comparable to the extended metal–organic frameworks that were previously employed for this separation such as UIO-66. Most importantly, this sieving system outperformed the well-known zeolitic imidazolate frameworks under low pressure, which opens the door to new generations of molecular sieves that can compete with extended frameworks for more sustainable hydrocarbon separation.     

Breaking Surface Atomic Monogeneity of Rh2P Nanocatalysts by Defect-Derived Phosphorus Vacancies for Efficient Alkaline Hydrogen Oxidation

Breaking atomic monogeneity of catalyst surfaces is promising for constructing synergistic active centers to cope with complex multi-step catalytic reactions. Here, we report a defect-derived strategy for creating surface phosphorous vacancies (P-vacancies) on nanometric Rh₂P electrocatalysts toward drastically boosted electrocatalysis for alkaline hydrogen oxidation reaction (HOR). This strategy disrupts the monogeneity and atomic regularity of the thermodynamically stable P-terminated surfaces. Density functional theory calculations initially verify that the competitive adsorption behavior of H_ad and OH_ad on perfect P-terminated Rh₂P{200} facets (p-Rh₂P) can be bypassed on defective Rh₂P{200} surfaces (d-Rh₂P). The P-vacancies enable the exposure of sub-surface Rh atoms to act as exclusive H adsorption sites. Therein, the H_ad cooperates with the OH_ad on the peripheral P-sites to effectively accelerate the alkaline HOR. Defective Rh₂P nanowires (d-Rh₂P NWs) and perfect Rh₂P nanocubes (p-Rh₂P NCs) are then elaborately synthesized to experimentally represent the d-Rh₂P and p-Rh₂P catalytic surfaces. As expected, the P-vacancy-enriched d-Rh₂P NWs catalyst exhibits extremely high catalytic activity and outstanding CO tolerance for alkaline HOR electrocatalysis, attaining 5.7 and 14.3 times mass activity that of p-Rh₂P NCs and commercial Pt/C, respectively. This work sheds light on breaking the surface atomic monogeneity for the development of efficient heterogeneous catalysts.     

断层破碎带中的透镜体及透镜体力学效应初步研究

断层破碎带中的透镜体及透镜体力学效应研究在文献中不多见。但是许多断层尤其是扭性断层中的透镜体非常发育,这些透镜体往往控制断层破碎带的强度大小和变形破坏机理,是工程岩体中必须重视的工程地质力学问题。作者经研究认为:(1)透镜体类型多种;(2)透镜体周边一般具断层泥线或泥膜分布;(3)透镜体内具有节理裂隙系统;(4)透镜体周边可以当作结构面或软弱结构面看待;(5)透镜体本身可以作为一个复合结构体看待。在原位力学试验中也揭示了断层泥透镜体在原位剪切试验和单轴压缩试验中的若干力学行为,其表现是:(1)透镜体周边具有结构面力学效应;(2)断层泥透镜体控制着强度大小、变形破坏机理。     

十三陵抽水蓄能电站上池西外坡岩体稳定分析

上池西外坡岩体稳定是十三陵抽水蓄能电站主要的地质工程问题之一，由于受到倾向池外的数条缓倾角断层以及不良的岩体结构控制，存在着滑动位移、变形失稳的可能性，电站的安全运行受到潜在的威胁。因此对西外坡岩体进行稳定分析，并进行补强处理是必要的。     

对蓬安县三元水库大坝外坡裂缝产生的原因及整治工程的探讨

本文通过对蓬安县三元水库大坝外坡裂缝产生的原因分析，进而运用岩、土力学的理论与方法反算推论出了裂缝的产生不是深层坝体土滑动引起的，而是局部浅层坝体土在水的诱发作用下作蠕滑-拉裂变形所产生的。在明确了大坝裂缝产生的原因后，提出了一系列相应整治工程措施，以达到彻底根治裂缝和稳固大坝的目的。     

高速公路工程中水泥搅拌桩桩身合理设计强度研究

在公路工程的搅拌桩地基设计中,一般假设加固区桩土变形协调,从而采用复合地基理论进行设计。但是目前许多的工程实践表明在路堤荷载作用下,搅拌桩地基桩土之间存在差异沉降,桩身强度不能够完全发挥,为此需要对复合模量的表达式进行改进。本文采用有限元分析了路堤荷载作用下搅拌桩地基的变形响应情况,分析了加固区桩间土变形与桩身模量之间关系,得到了水泥土搅拌桩强度的合理范围。