Latest ArticlesDue to its high theoretical capacity and appropriate potential platform, tin-based alloy materials are expected to be a competitive candidate for the next-generation high performance anodes of lithium-ion batteries. Nevertheless, the immense volume change during the lithium-ion insert process leads to severe disadvantages of structural damage and capacity fade, which limits its practical application. In this work, a three-dimensional (3D) multicore-shell hollow nanobox encapsulated by carbon layer is obtained via a three-step method of hydrothermal reaction, annealing and alkali etching. During the electrochemical reactions, the CoSn@void@C nanoboxes provide internal space to compensate the volumetric change upon the lithiation of Sn, while the inactive component of Co acts as chemical buffers to withstand the anisotropic expansion of nanoparticles. Owing to the above-mentioned advantages, the elaborated anode delivers an excellent capacity of 788.2 mAh/g at 100 mA/g after 100 cycles and considerable capacity retention of 519.2 mAh/g even at a high current density of 1 A/g after 300 cycles. The superior stability and high performance indicate its capability as promising anodes for lithium-ion batteries.
The first-principles calculations demonstrate that covalently bonded (cb) heterojunction and van der Waals (vdW) heterojunction can coexist in silicene/CeO2 heterojunctions, due to the different stacking patterns. Especially, the cb heterojunction with band gap of 1.97 eV, forms a type-II heterojunction, exhibits good redox performance and has high-effective optical absorption spectra, thus it is a promising photocatalyst for overall water splitting. Besides, for the vdW heterojunction, the Dirac cone of silicene is well kept on CeO2 semiconducting substrate, with a considerable energy gap of 0.43 eV, which can be an ideal material in building silicene-based electronic device. These results may open a new gateway in both of nanoelectronic device and energy conversion for silicene/CeO2 nanocomposites.
We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes. This mild and operationally simple protocol is distinguished by its broad substrate scope and excellent chemo-, regio-, and stereo-selectivity, offering a new and organometallic agent-free platform for the construction of fluoroalkyl-incorporated diene motifs. Preliminary mechanistic studies have been conducted to probe the potential reaction pathway.
Herein, we report a practical electro-reductive protocol for the direct C–H cyanoalkylation of quinoxalin-2(1H)-ones via iminyl radical-mediated ring opening. These mild reactions proceed under metal-, reductant-, and reagent-free conditions to provide synthetically useful cyanoalkylated quinoxalin-2(1H)-ones.
A Ru(Ⅲ)-catalyzed annulation reaction of 2-aminoaromatic aldehydes (ketones) and isoxazoles to afford diverse 3-cyanoquinolines has been developed. Notably, isoxazole acted as a cyclization reagent and nontoxic cyano source via N-O bond cleavage and fragmentation. Variously substituted (especially 6- or 7-substituted) quinolines could be easily afforded. This procedure features wide functional group compatibility, efficiency and avoiding toxic cyano source. Meanwhile, this protocol could be successfully applied to scale-up synthesis. Further chemical transformations of 3-cyanoquinoline could give some valuable skeletons, demonstrating its potential in synthetic application
With an intensive understanding of the mechanism of immune system, developing a therapeutic tumor vaccine is one of the most perspective strategy of cancer immunotherapy. In this study, we report a facile approach to prepare graphene oxide (GO)-based therapeutic cancer-nanovaccine. The model antigen (ovalbumin, OVA) and adjuvant (CpG ODN), are conjugated with GO-PEI nanosheet through electrostatic interaction. The addition of PEG can improve biocompatibility and prevent nanoparticle aggregation. The prepared GO-based nanovaccine, GO-PEI-OVA-PEG-CpG, exhibits good biocompatibility and low toxicity both in vivo and in vitro. More importantly, it can efficiently induce the maturation of dendritic cells (DCs), the enhancement of antigen cross-presentation ability, and the amplification of cytokine production of immune cells. Impressively, this nanovaccine shows a remarkable therapeutic effect against pre-established B16-OVA-melanoma tumors, which can significantly inhibit tumor growth and prolong the survival time of the OVA-expressed tumor-bearing mice. Moreover, combining GO-PEI-OVA-PEG-CpG with NLG919, an IDO-1 (indoleamine-2,3-dioxygenase) inhibitor which can regulate the tumor microenvironment, displays a synergistic therapeutic effect. These findings indicate the GO-PEI-OVA-PEG-CpG nanovaccine actively induces an antigen-specific antitumor immune response and it combined with NLG919 could achieve better therapeutic outcomes.
Sugar-dependent targeting and immune adjuvant effects of hyperbranched glycosylated polypeptide nanoparticles were disclosed for ovalbumin (OVA) delivery system. The mannose-coated polypeptide nanoparticles can induce strongest targeting and immune adjuvant effects to macrophages than those glucose/lactose-coated ones, which effectively transported OVA into cells and facilitated OVA subcellular escape from endolysosomes into cytoplasm with the assistance of UV irradiation or intracellular acidic pH.
Targeted alpha-therapy (TAT) is increasingly attractive due to its extraordinary antitumor efficacy. However, the supply of α-emitters for TAT is insufficient and under control by a limited number of countries. 212Pb is a promising α-emitter with an optimal half-life (10.6 h) and favored decay chain. Of interest, 212Pb can be extracted directly from natural thorium, which may be abundant in the mining waste of rare-earth, uranium, etc. Indeed, radioactive thorium waste has been a longstanding environmental challenge that needs immediate action. Developing an on-demand and facile process to isolate 212Pb from natural thorium would be ideal to meet the above challenges, yet is difficult. In theory, the ratio of 212Pb to natTh is below 10−13 in commercially available thorium salts. As a pilot study, 2.2 MBq of 212Pb was successfully extracted from a 5 L solution of thorium nitrate by using a Pb-selective resin. The radiochemical purity of 212Pb is over 99.9% according to gamma-ray analysis. The purified 212Pb was applied to radiolabel a couple of peptides used in clinics (i.e. PSMA, TATE and FAPI-04), and the radiochemical yields are > 85%. Of note, 212Pb can be repeatedly separated from the thorium solution every 2 days. In summary, a practical and scalable method was developed to isolate 212Pb for potentially clinical use, which may be of great importance as it does not require either cyclotron or nuclear reactor.
The extraction complexes of uranyl(Ⅵ) in HNO3 to a hydroxyl-functionalized ionic liquid (IL) phase, HOEtmimNTf2 bearing CMPO, were investigated. Three possibly successive extraction complexes, UO2L2+ (L = CMPO), UO2L22+ and UO2L32+, were detected based on variable U/L ratios. Uranyl(Ⅵ) prefers to be extracted as complex UO2L32+, combining with the ions from HOEtmimNTf2 to construct a solid material through self-assembly. The thermodynamics of complexes, UO2L2+ (j = 1-3), were studied by spectrophotometry and microcalorimetry. All the formation reactions are principally driven by entropy, although a small part of the driving force of complexes UO2L22+ and UO2L32+ comes from enthalpy. Based on the thermodynamic properties for complex UO2L32+, we provide a possible coordination mode in HOEtmimNTf2: the first CMPO molecule coordinates with UO22+ in a bidentate fashion while the others do in a monodentate fashion. The results offer a thermodynamic insight into the formation behaviors of the uranyl(Ⅵ)/CMPO complexes involving the special IL HOEtmimNTf2, which is of significance to advance the novel IL extraction strategy.