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are considered as suitable candidates for various applications such as gas storage, separation, and catalysis because of their highly ordered structure and tailored porosity (microporosity (<2 nm), mesoporosity (2-50 nm), and macroporosity (>50 nm)). [15,16] However, the development of a kind of porous organic materials with a predesignable structure remains a great challenge, which is crucial to achieve desirable and tunable functionalities. The emergence of "reticular chemistry" enlightened the discovery of a kind of novel porous polymeric material, [17][18][19] namely covalent organic frameworks (COFs). COFs are crystalline, porous, organic polymers composed of organic building blocks and interconnected by strong covalent bonds, which are receiving substantial attention due to their unique features of light weight, good thermal stability, permanent and periodic porosity, adjustable pore sizes, and large surface area. [20][21][22][23][24][25] Inspired by these merits, COFs have emerged as ideal candidates for a wide range of applications, such as gas storage and separation, [26][27][28][29][30] adsorption, [31][32][33] catalysis, [34][35][36][37] sensors, [38,39] optoelectronics devices, [40,41] drug delivery, [42][43][44] energy storage and conversion. [45][46][47][48][49] Unlike the traditional amorphous organic polymers which are formed by strong but irreversible covalent bonds, COFs allow reversible condensation between building blocks, [50,51] leading to the construction of highly ordered crystalline structures due to the "error correction" during the crystallization process. [52,53] Depending on the topological establishment of building blocks, COFs are classified into 2D COFs and 3D COFs. [54,55] Notably, 2D COFs are commonly regarded as a new class of layer-stacked materials and have attracted considerable interests because they exhibit not only 2D extended layered structures but also periodic columnar π-arrays. [56][57][58] The first two 2D COFs linked by boroxine and boronate ester were reported in 2005, [59] which were highly sensitive to acid, base, and even moisture, demonstrating reasonably poor chemical stability. Since then, a large number of robust 2D COFs have been reported to be constructed from numerous chemically stable linkages such as triazine, [60] imine, [61][62][63][64] hydrazone, [65] imide, [66,67] ether, [68] olefin, [69] and oxazole [70,71] (Figure 1a). In addition, based on the symmetry of the monomers, 2D COFs can be designed in various topologies (tetragonal, hexagonal, rhombic, and trigonal), exhibiting different pore sizes and shapes (Figure 1b). By Covalent organic frameworks (COFs), an emerging class of organic crystalline polymers with highly oriented structures and permanent porosity, can adopt 2D or 3D architectures depending on the different topological diagrams of the monomers. Notably, 2D COFs have particularly gained much attention due to the extraordinary merits of their extended in-plane π-conjugation and topologically ordered columnar π-arrays. These properties tog...

The sandwich technique in combination with chimney grafts permits a total endovascular exclusion of thoraco abdominal aortic aneurysms. In all cases off-the shelf products and grafts could be used. The number of patients treated so far is still too small to draw further more robust conclusions with regard to long term performance and durability.

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In repairs for type B ADs, the chimney technique provides a minimally invasive way of preserving flow to the arch branches combined with a favourable mid-term outcome. The bare stents seemed to be related to a higher probability of the immediate type I endoleaks. A balloon-expandable stent should be regarded as the first choice due to its greater radial strength.

Electrochemical reduction of CO 2 into value-added chemicals provides a promising approach to mitigate climate change caused by CO 2 from excess consumption of fossil fuels. As the CO 2 molecule is chemically inert and the reaction kinetics is sluggish, efficient electrocatalysts are thus highly required for promoting the conversion of CO 2 . With great efforts devoted to improving the catalytic performance, the development of electrocatalysts for CO 2 reduction has gone from bulk metals with poor control to nanostructures with atomic precision. Nanostructured electrocatalysts with atomic precision are believed to be capable of combining the advantages of heterogeneous and homogenous catalysts. In this review, the recent advances in designing nanostructured electrocatalysts at the atomic level for boosting the catalytic performance toward CO 2 reduction and revealing the structure-property relationship are summarized. The challenges and opportunities in the near future are also proposed for paving the development of electrocatalytic CO 2 reduction.half reactions and equilibrium potentials (versus reversible hydrogen electrode (RHE)) are listed as Reaction (1) to (6): [7] CO 2H 2e HCOOH 0.12 V Adv. Funct.

Tuning the intrinsic strain of Pt‐based nanomaterials has shown great promise for improving the oxygen reduction reaction (ORR) performance. Herein, reported is a tunable surface strain in penta‐twinned ternary Pt–Cu–Mn nanoframes (NFs). Pt–Cu–Mn ultrafine NFs (UNFs) exhibit ≈1.5% compressive strain compared to Pt–Cu–Mn pentagonal NFs (PNFs) and show the superior activity toward ORR in an alkaline environment. Specifically, the specific and mass activity of Pt–Cu–Mn UNFs are 3.38 mA cm−2 and 1.45 A mg−1, respectively, which is 1.45 and 1.71 times higher than that of Pt–Cu–Mn PNFs, demonstrating that compressive strain in NFs structure can effectively enhance the catalytic activity of ORR. Impressively, Pt–Cu–Mn UNFs exhibit 8.67 and 9.67 times enhanced specific and mass activity compared with commercial Pt/C. Theoretical calculations reveal that compression on the surface of Pt–Cu–Mn UNFs can weaken the bonding strengths and adsorption of oxygen‐containing intermediates, resulting in an optimal condition for ORR.

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