The fact that the lifetime of photoluminescence is often difficult to access because of the weakness of the emission signals, seriously limits the possibility to gain local bioimaging information in ...time‐resolved luminescence probing. We aim to provide a solution to this problem by creating a general photophysical strategy based on the use of molecular probes designed for single‐luminophore dual thermally activated delayed fluorescence (TADF). The structural and conformational design makes the dual TADF strong in both diluted solution and in an aggregated state, thereby reducing sensitivity to oxygen quenching and enabling a unique dual‐channel time‐resolved imaging capability. As the two TADF signals show mutual complementarity during probing, a dual‐channel means that lifetime mapping is established to reduce the time‐resolved imaging distortion by 30–40 %. Consequently, the leading intracellular local imaging information is serialized and integrated, which allows comparison to any single time‐resolved signal, and leads to a significant improvement of the probing capacity.
Luminogens for a superior time‐resolved (TR) imaging effect with channel selectivity were achieved by engineering dual thermally activated delayed fluorescence (TADF) from anti‐Kasha/Kasha emission pathways. Intracellular local imaging information that is serialized and integrated was observed by calibrating the two TR signals. The technology is pertinent to precision medicine as TR signals are typically difficult to access in weak emission areas.
The conductive framework is generating considerable interest for lithium metal anodes to accommodate Li+ deposition, due to its ability to reduce electrode current density by increasing the ...deposition area. However, in most cases, the electroactive surface area is not fully utilized for the nucleation of Li in 3D current collectors, especially under high current densities. Herein, uniform nucleation of Li in the conductive skeleton is achieved by a two-step synergetic process arising from CuBr- and Br-doped graphene-like film. The modified electrode regulates Li nucleating in uniform pancake-like seeds and growing into a granular Li metal ascribed to the excellent lithiophilicity of CuBr- and Br-doping sites and the low Li diffusion barrier on the surface of generated LiBr, as confirmed by the experimental and computational results. Therefore, the modified anode endows small nucleation overpotential, a high-reversibility Li plating/stripping process, and excellent performance in full batteries with industrially significant cathode loading. This work suggests that a two-step cooperative strategy opens a viable route to the development of a Li anode with high reversibility for stable cycling Li metal batteries.
In pursuit of novel adsorbents with efficient adsorptive gas storage and separation capabilities remains highly desired and challenging. Although the documented zirconium‐tricarboxylate‐based ...metal–organic frameworks (MOFs) have displayed a variety of topologies encompassing underlying and geometry mismatch ones, the employed organic linkers are exclusively rigid and poorly presenting one type of conformation in the resultant structures. Herein, a used and semirigid tricarboxylate ligand of H3TATAB was judiciously selected to isolate a zirconium‐based spe‐MOF after the preliminary discovery of srl‐MOF. Single‐crystal X‐ray diffraction reveals that the fully deprotonated TATAB linker in spe‐MOF exhibits two distinct conformers, concomitant with popular Oh and rare S6 symmetrical Zr6 molecular building blocks, generating an unprecedented (3,3,12,12)‐c nondefault topology. Specifically, the spe‐MOF exhibits structurally higher complexity, hierarchical micropores, open metal sites free and rich electronegative groups on the pore surfaces, leading to relatively high methane storage capacity without considering the missing‐linker defects and efficient MTO product separation performance.
One topologically unprecedented zirconium–organic framework was successfully assembled by virtue of a used and semirigid tricarboxylate ligand via ligand‐conformer‐induction. The spe‐MOF exhibits relatively high methane storage capacity and efficient MTO product separation performance due to its integrated features, shedding light on the development of novel zirconium‐based adsorbents by the utilization of semirigid organic linkers aiming advanced applications.
Li-rich layered materials have been considered as the most promising cathode materials for future high-energy-density lithium-ion batteries. However, they suffer from severe voltage decay upon ...cycling, which hinders their further commercialization. Here, we report a Li-rich layered material 0.5Li2MnO3·0.5LiNi0.8Co0.1Mn0.1O2 with high nickel content, which exhibits much slower voltage decay during long-term cycling compared to conventional Li-rich materials. The voltage decay after 200 cycles is 201 mV. Combining in situ X-ray diffraction (XRD), ex situ XRD, ex situ X-ray photoelectron spectroscopy, and scanning transmission electron microscopy, we demonstrate that nickel ions act as stabilizing ions to inhibit the Jahn–Teller effect of active Mn3+ ions, improving d–p hybridization and supporting the layered structure as a pillar. In addition, nickel ions can migrate between the transition-metal layer and the interlayer, thus avoiding the formation of spinel-like structures and consequently mitigating the voltage decay. Our results provide a simple and effective avenue for developing Li-rich layered materials with mitigated voltage decay and a long lifespan, thereby promoting their further application in lithium-ion batteries with high energy density.
The optimal hypothermic level in total arch replacement with stented elephant trunk implantation for acute type A aortic dissection (aTAAD) has not been established, and the superiority of unilateral ...or bilateral cerebral perfusion remains a controversial issue. Therefore, we evaluated the application of moderate hypothermic circulatory arrest (MHCA) with a core temperature of 29 °C and bilateral selective antegrade cerebral perfusion in aTAAD treated by total arch replacement with stented elephant trunk implantation.
From July 2019 to January 2020, 25 aTAAD patients underwent total arch replacement with stented elephant trunk implantation via MHCA (29 °C) and bilateral selective antegrade cerebral perfusion (modified group). Thirty-six patients treated by the same procedure with MHCA (25 °C) and unilateral selective antegrade cerebral perfusion during this period were selected as controls.
There were no differences between the two groups of patients in terms of age, sex, incidence of hypertension, malperfusion, and pericardial effusion, although the incidence of cardiac tamponade was higher in the modified group (control 2.8%, modified 20%; P = 0.038). The lowest mean circulatory arrest temperature was 24.6 ± 0.9 °C in the control group, and 29 ± 0.8 °C in the modified group (P < 0.001). In-hospital mortality was 4.9% (3/61) for the entire cohort (control 8.3%, modified 0; P = 0.262). The incidence of permanent neurologic deficit was 4.9% (control 8.3%, modified 0; P = 0.262). There were no significant differences in the occurrence of temporary neurological deficit, renal failure, and paraplegia between groups. The rate of major adverse events in the modified group was lower (30.6% vs. 4%, P = 0.019). A shorter duration of ventilation and ICU stay was identified in the modified group, as well as a reduced volume of drainage within the first 48 h and red blood cell transfusion.
The early results of MHCA (29 °C) and bilateral selective antegrade cerebral perfusion applied in total arch replacement with stented elephant trunk implantation for aTAAD were acceptable, providing similar inferior cerebral and visceral protection compared with that of the conventional strategy. A higher core temperature may account for the shorter duration of ventilation and ICU stay, as well as a reduced volume of drainage and red blood cell transfusion.
Sufficient swelling pressure of compacted bentonite upon wetting is necessary to provide long-term stability to an engineered barrier system under conditions of thermal gradient and variable water ...chemistry in a high-level radioactive waste repository. To investigate the combined thermal and saline effects on the swelling pressure of Gaomiaozi (GMZ) bentonite, constant-volume swelling pressure tests were performed on densely compacted specimens inundated with deionized water, NaCl, and CaCl2 solutions at 20 °C and 60 °C. The results indicate that high temperature and saline solutions decrease the swelling pressure. Crystalline swelling dominates the constant-volume swelling of densely compacted bentonite. For a given cation type, a higher temperature or higher solution concentration resulted in a lower swelling pressure. The decreasing surface potential and increasing osmotic suction with solution concentration both weaken the clay swelling. The effects of temperature on the swelling pressure are explained by the role of the lattice contraction. The degeneration of the interlamellar adsorbed water at high temperature weakens the crystalline swelling. The effects of cation types are interpreted by their difference in chemical activity. Ca2+ ions possess higher exchange capacity and larger hydrated radius than those of the Na+ ions. When densely compacted Na-bentonite is wetted with CaCl2 solution, the possible change of the interlamellar cations from Na+ to Ca2+ ions would promote the crystalline swelling. The osmotic suction imposed by CaCl2 solution may offset the role of the cation exchange to a small extent. The effect of temperature on the swelling pressure exceeds that of the cation types. For a given solution concentration, the specimen wetted with NaCl solution developed lower swelling pressure than that with CaCl2 solution at 20 °C, whereas the opposite tendency appeared at 60 °C. In addition, specimens saturated with deionized water and NaCl solution at 20 °C obtained insignificant difference in pore size distribution, whereas identifiable differences in pore size distribution occured at 60 °C. The combined thermal and saline effects on the swelling pressure may be explained by the role of the lattice contraction at varied clay structure. When CaCl2 solution is used, the quasicrystals contain more montmorillonite layers than the case of the NaCl solution. The role of the lattice contraction at high temperature is expected to decrease the swelling pressure to a greater degree in the case of the CaCl2 solution. The remarkable increase in the osmotic suction at high temperature and high solution concentration could also enlarge the decrease in the swelling pressure. These conjectures, however, still require quantitative interpretations via microscopic tests such as X-ray powder diffraction tests on bulk samples.
•High temperature preferentially dominates crystalline swelling.•High temperature has greater effects on PSD.
Reticular chemistry and methane storage materials have been predominately focused on finite metal-cluster-based metal–organic frameworks (MOFs). In contrast, MOFs constructed from infinite rod ...secondary building units (SBUs), i.e., rod MOFs, are less developed, and the existing ones are typically built from simple one-way helical, zigzag, or (mixed)polyhedron SBUs. Herein, inspired by a recent unveiled structure of Zn6(H2O)3(BTP)4 and by means of an amide-functionalized preliminary single tricarboxylate, a subsequent mixed tricarboxylate, and dicarboxylate linkers, an intricate three-way rod MOF and the next three isoreticular three-way rod MOFs have been successfully realized, namely, 3W-ROD-1 and 3W-ROD-2-X (X = −OH, −F, and −CH3), respectively. The structural analyses disclosed that the four compounds were constructed from unprecedented three-way invariant nonintersecting trigonal rod-packing SBUs cross-linked via the noncovalent-interaction-driven self-assembly of pseudo hexacarboxylates with the original tricarboxylate or different functional ditopic linkers, resulting in cage-like pore geometries accessible via ultramicroporous apertures concomitant with the complex topology transitivity, namely, 18 42 and 18 44. Sorption studies show that the apparent surface areas of these materials are among the most highly porous materials for rod MOFs. Due to the presence of favorable pocket sites created by X, ketone, and proximal amide groups as revealed by Monte Carlo molecular dynamics (MCMD) computational calculations, the MOFs exhibit impressive methane storage working capacities, outperforming the well-known rod Ni-MOF-74 and representing the highest values among rigid rod MOFs.
Current wound scaffold dressing constructs can facilitate wound healing but do not exhibit antibacterial activity, resulting in high infection rates. We aimed to endow wound scaffold dressing with ...anti‐infective ability by polyhexamethylenebiguanide (PHMB). We prepared PHMB hydrogel at varying concentrations (0.25%, 0.5%, 1%, 2%) and assessed release and cytotoxicity. PHMB hydrogel was added to the wound scaffold dressing to generate a PHMB hydrogel‐modified wound scaffold dressing. Wound healing and infection prevention were evaluated using a full‐thickness skin defect model in rats. In vitro, the hydrogel PHMB release time positively correlated with PHMB concentration, with 1% allowing sufficiently long release time to encompass the high‐incidence period (3‐5 days) of infection following wound scaffold dressing implantation. Implantation of 1% PHMB hydrogel into the skin did not cause adverse responses. in vitro cytotoxicity assays showed the PHMB hydrogel‐modified wound scaffold dressing did not significantly affect proliferation of fibroblasts or vascular endothelial cells, 99.90% vs 99.84% for fibroblasts and 100.21% vs 99.28% for vascular endothelial cells at 21 days. Transplantation of PHMB hydrogel‐modified wound scaffold dressing/unmodified wound scaffold dressing on the non‐infected wounds of rats yielded no significant difference in relative vascularization rate, 47.40 vs 50.87 per view at 21 days, whereas bacterial content of the wound tissue in the PHMB hydrogel‐modified wound scaffold dressing group was significantly lower than the unmodified wound scaffold dressing group, (1.80 ± 0.35) × 103 vs (9.34 ± 0.45) × 103 at 14 days. Prevalence of persistent wound infection in the rats receiving PHMB hydrogel‐modified wound scaffold dressing transplantation onto infected wounds was significantly lower than the unmodified wound scaffold dressing group, 30% vs 100%. PHMB hydrogel‐modified wound scaffold dressing exhibited suitable antibacterial ability, and its biological activity did not significantly differ from that of the unmodified wound scaffold dressing, thereby allowing it to effectively prevent infection following wound scaffold dressing implantation.
Memory plays a vital role in modern information society. High‐speed and low‐power nonvolatile memory is urgently demanded in the era of big data. However, ultrafast nonvolatile memory with ...nanosecond‐timescale operation speed and long‐term retention is still unavailable. Herein, an ultrafast nonvolatile memory based on van der Waals heterostructure is proposed, where a charge‐trapping material, graphdiyne (GDY), serves as the charge‐trapping layer. With the band‐engineered heterostructure and excellent charge‐trapping capability of GDY, charges are directly injected into the GDY layer and are persistently captured by the trapping sites in GDY, which result in an ultrafast writing speed (8 ns), a low operation voltage (30 mV), and a long retention time (over 104 s). Moreover, a high on/off ratio of 106 is demonstrated by this memory, which enables the achievement of multibit storage with 6 discrete storage levels. This device fills the blank of ultrafast nonvolatile memory technology, which makes it a promising candidate for next‐generation high‐speed and low‐power‐consumption nonvolatile memory.
A novel semi‐floating‐gate nonvolatile memory based on van der Waals heterostructure is proposed, which combines the advantages of ultrafast writing speed (8 ns), low operation voltage (2–30 mV), long retention time (over 104 s), and high on/off ratio (106). This memory device fills the blank of ultrafast nonvolatile memory technology.
Porous carbon and metal oxides/sulfides prepared by using metal–organic frameworks (MOFs) as the precursors have been widely applied to the realm of supercapacitors. However, employing MOF‐derived ...metal phosphides as positive and negative electrode materials for supercapacitors has scarcely been reported thus far. Herein, two types of MOFs are used as the precursors to prepare CoP and FeP4 nanocubes through a two‐step controllable heat treatment process. Due to the advantages of composition and structure, the specific capacitances of FeP4 and CoP nanocubes reach 345 and 600 F g−1 at the current density of 1 A g−1, respectively. Moreover, a quasi‐solid‐state asymmetric supercapacitor is assembled based on charge matching principle by employing CoP and FeP4 nanocubes as the positive and negative electrodes, respectively, which exhibits a high energy density of 46.38 Wh kg−1 at the power density of 695 W kg−1. Furthermore, a solar‐charging power system is assembled by combining the quasi‐solid‐state asymmetric supercapacitor and monocrystalline silicon plates, substantiating that the device can power the toy electric fan. This work paves a practical way toward the rational design of quasi‐solid‐state asymmetry supercapacitors systems affording favorable energy density and long lifespan.
CoP and FeP4 nanocubes with unique structure are prepared successfully by phosphorization engineering with two types of metal–organic frameworks as precursors. Based on the charge matching principle, a quasi‐solid‐state asymmetric supercapacitor is assembled by using CoP and FeP4 nanocubes as positive and negative electrodes, which exhibits good electrochemical performance.
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