Latest ArticlesFluorescence-guided surgery calls for development of near-infrared fluorophores. Despite the wide-spread application and a safe clinical record of Indocyanine Green (ICG), its maximal absorption wavelength at 780 nm is rather short and longer-wavelength dyes are desired to exploit such benefits as low photo-toxicity and deep penetration depth. Here, we report ECY, a stable deep near-infrared (NIR) fluorochromic scaffold absorbing/emitting at 836/871 nm with a fluorescence quantum yield of 16% in CH2Cl2. ECY was further rationally engineered for biological distribution specificity. Analogous bearing different numbers of sulfonate group or a polyethylene glycol chain were synthesized. By screening this focused library upon intravenous injection to BALB/c mice, ECYS2 was identified to be a suitable candidate for bioimaging of organs involved in hepatobiliary excretion, and ECYPEG was found to be a superior candidate for vasculature imaging. They have potentials in intraoperative imaging.
Li metal is considered an ideal anode material because of its high theoretical capacity and low electrode potential. However, the practical usage of Li metal as an anode is severely limited because of inevitable parasitic side reactions with electrolyte and dendrites formation. At present, single-component artificial solid electrolyte interphase cannot simultaneously meet the multiple functions of promoting ion conduction, guiding lithium ion deposition, inhibiting dendrite growth, and reducing interface side reactions. Therefore, multi-component design on Li metal surface is widely investigated to achieve long-term cycling. Herein, we report a Li2Ga-carbonate polymer interphase layer to solve volume changes, Li dendrites formation and side-reactions. As a result, the Li symmetric cell can be stabilized at 3.0 mA/cm2 in carbonate electrolyte with limited volume of 20 µL. Coupled with 13.6 mg/cm2 (loading of 2 mAh/cm2) LiFePO4 cathode, discharge capacity retains at 90% for over 150 cycles under limited electrolyte conditions. With such an alloy-polymer interphase layer, higher energy density Li metal batteries become prominent in the near future.
Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative, 5-aryl-1, 3-dioxan-5-ol, as versatile 1, 3-biselectrophile. In the reactions, 5-aryl-1, 3-dioxan-5-ol works like atropaldehydes or 2-aryl malondialdehydes, and can react with 2-naphthols and β-keto amides, allowing the synthesis of 4H-chromenes and 5-aryl-2-pyridinones. High yields, good functional group tolerance, broad substrate scope and simple reaction operation make this protocol attractive.
The precise synthesis of polymer with narrow molecular weight distribution (Đ) and well-defined architectures is very essential to exploring the functions and properties of polymer materials. Here, a universal polymerization method capable of low Đ and reactive hydrogen compatibility is reported by introducing super-Grignard reagents (R2Mg·LiCl) into polymer chemistry. Under mild conditions, various monomers, including nonpolar polystyrene and 4-methoxystyrene that cannot be initiated by Grignard reagents, and polar methacrylate, are successfully polymerized with full monomer conversion and low Đ. This approach is amenable to wide varieties of initiators, polymerization temperature, and feed ratio, which makes it attractive for applications in polymer synthesis. By adding methanol and water during the polymerization process, the reactive hydrogen compatibility of this method is confirmed, which makes this method avoid the rigorous restriction on polymerization conditions of anionic polymerization. Moreover, chain extension polymerization and block copolymerization are achieved and demonstrate the livingness of chain propagation, enabling the facile synthesis of well-defined macromolecular architectures. This work therefore expands the methodology libraries of living polymerization, which may cause inspirations to polymer science.
Herein, we report an efficient photochemical method for the synthesis of poly-substituted pyrazoles through a multicomponent reaction of acceptor-only diazoalkanes, alkynes, and solvents (cyclic ethers or nitriles). The key to this success was driven by the photolysis of acceptor-only diazoalkanes to form free carbene species and the fast in situ [3 + 2]-cycloaddition formation of nucleophilic NH pyrazole derivatives. This work also serves as an entry to allow future reaction design on the combination of carbene reactivity of diazoalkanes with their other reaction modes.
Adoptive immunotherapy expressing synthetic chimeric antigen receptors (CAR) on T cells through in vitro modifications represents a new and innovative strategy in cancer treatment. This new approach enables T cells to recognize and bind tumor antigens via a single-chain variable fragment recognition domain, circumventing the restriction of major histocompatibility complex. This review summarized the structure/design of CAR-T cells and the evolution process this technology went through, displaying the theoretical foundation for CAR-T therapy, the marketed products and the latest preclinical and clinical research progress. Finally, we provided perspectives on this technology's development and potential future applications, especially for treating hematological malignant and solid tumors.
The electro-peroxone technology, a novel type of advanced oxidation technology, is widely used in wastewater treatment. Herein, this paper reviews the advantages and problems of the electro-peroxone technology compared with electrochemical oxidation technology, ozonation technology, and traditional peroxone technology. Due to the high kinetics of pollutant degradation, the electro-peroxone process can reduce the reaction time and energy consumption of pollutant treatment in wastewater. The electro-peroxone technology can promote pollutant degradation and mineralization, which shows obvious synergistic effects of electrochemical oxidation and ozonation for wastewater treatment. Most importantly, the research mechanism of the electro-peroxone technology is systematically introduced from two aspects of cathode reaction and bulk reaction. The influence of experimental parameters on the wastewater treatment effect is also discussed. Finally, the potential applications and future research directions of the electro-peroxone technology in the wastewater field are proposed. The electro-peroxone process can offer a highly efficient and energy saving water treatment method to improve the performance of existing ozonation and electrochemical systems and has therefore become a promising electrochemical advanced oxidation process for wastewater treatment.
Two dimensional (2D) materials are promising gas sensing materials, but the most of them need to be heated to show promising sensing performance. Sensing structures with high sensing performance at room-temperature are urgent. Here, another 2D material, violet phosphorus (VP) nanoflake is investigated as gas sensing material. The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol. The VP nanoflakes are combined with graphene to form VP/G heterostructures-based NO sensor. An ultra-high gauge factor of 3 × 107 for ppb-level sensing and high resistance response of 59.21% with ultra-short recovery time of 6s for ppm-level sensing have been obtained. The sensing mechanism is also analysed by density functional theory (DFT) calculations. The adsorption energy of VP/G is calculated to be −0.788 eV, resulting in electrons migration from P to N to form a P−N bond in the gap between VP and graphene sheet. This work provides a facile approach to ablate VP for mass production. The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.
The misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems. Herein, a piezoelectic odd-layered MoS2 is prepared and applied to piezo-catalytic remove tinidazole (TNZ) and other antibiotic pollutants with aeration as a piezo-driving force. About 89.6% of TNZ can be degraded by MoS2 under aeration in the presence of dissolved oxygen with a reaction rate constant of 0.15 min−1, which is 2.4 times higher than that under N2 atmosphere and quiescence conditions. Quenching experiments and electron paramagnetic resonance (EPR) tests identify that singlet oxygen (1O2) and superoxide radical (O2•−) are dominant reactive oxygen species in MoS2/aeration system. These results demonstrate that MoS2 can trigger a piezoelectric effect and produce charge carriers to generate reactive oxygen species with dissolved oxygen (DO) for contaminant degradation with the turbulence and water bubbles rupture driven by aeration.