Latest ArticlesHigh entropy oxides (HEOs) have attracted extensive attention of researchers due to their remarkable properties. The electrocatalytic activity of electrocatalysts is closely related to the reactivity of their surface atoms which usually shows a positive correlation. Excellenet stability of HEOs leads to their surface atoms with relative poor reactivity, limiting the applications for electrocatalysis. Therefore, it is significant to activate surface atoms of HEOs. Constructing amorphous structure, introducing oxygen defects and leaching are very effective strategies to improve the reactivity of surface atoms. Herein, to remove chemical inert, low-crystallinity (Fe, Co, Ni, Mn, Zn)3O4 (HEO-Origin) nanosheets with abundant oxygen vacancies was synthesized, showing an excellent catalytic activity with an overpotential of 265 mV at 10 mA/cm2, which outperforms as-synthesized HEO-500℃-air (335 mV). The excellent catalytic performance of HEO-Origin can be attributed to high activity surface atoms, the introduction of oxygen defects efficiently altered electron distribution on the surface of HEO-Origin. Apart from, HEO-Origin also exhibits an outstanding electrochemical stability for oxygen evolution reaction (OER).
Based on the reported Fe clusters constructed by using N-tris(hydroxymethyl)methylglycine (H5thmmg), herein, we explored the use of H5thmmg for Ni chemistry. Successfully, an octanuclear Ni cluster, Ni8O(H3thmmg)6·2NO3 (Ni8) was acquired under solvothermal condition. Its metallic core is comprised of two centrosymmetric cubanes Ni4(µ3-O)3(µ6-O) linked by sharing an O2− ion and six H3thmmg2− ligands are attached to the periphery. Interestingly, the 2-mercapto-5-amino-1,3,4-thiadiazole (Hmat) ligand with both N and S donor atoms was introduced into the synthesis of Ni8 cluster, a disparate decanuclear nickel cluster, Ni10O(OH)2(H3thmmg)4(mat)8 (Ni10) is assembled by H3thmmg2− and mat− mixed ligands. The metal core of Ni10 cluster is a pudgy tetrahedron, whose four vertexes are four Ni2+ ions and the remanent six Ni2+ ions are located in the tetrahedral cavity. Four H3thmmg2− ligands are located at the four vertices of the tetrahedron and 8 mat− ligands are all on the six sides of the tetrahedron. The different synthetic conditions contribute to the different configurations. Magnetic studies indicate that both complexes Ni8 and Ni10 display antiferromagnetic interactions.
Although SiO2-based anode is a strong competitor to supersede graphite anode for lithium-ion batteries, it still has problems such as low electrochemical activity, enormous loss of active lithium, and serious volume expansion. In order to solve these problems, we used a graphene network loaded with cobalt metal nanoparticles (rGO–Co) to coat SiO2 porous hollow spheres (SiO2@rGO–Co). The construction of porous hollow structure and graphene network can shorten the lithium-ion (Li+) diffusion distance and enhance the conductivity of the composite, which improves the electrochemical activity of SiO2 effectively. They also alleviate the volume expansion of the anode in the cycling process. Moreover, nano-scale cobalt metal particles dispersed on graphene catalyze the conversion reaction of SiO2 and activate the locked Li+ in Li2O through a reversible reaction, which improves the charge and discharge capacity of the anode. The capacity of SiO2@rGO–Co reaches 370.4 mAh/g after 100 cycles at 0.1 A/g, which is 6.19 times the capacity of pure SiO2 (59.8 mAh/g) under the same circumstance. What is more, its structure also exhibits excellent cycle stability, with a volume expansion rate of only 13.0% after 100 cycles at a current density of 0.1 A/g.
Versatile module design of precursor networks enables flexible functionalization of nano-carbon electrode materials to meet the adaptable energy-storage demand. Functionalized heterogeneous networks are more likely to decompose by swift temperature programming together with predesign module removal, so high functionality/network transfer from precursor to carbon is still a work in progress. A pre-stabilization route is proposed here to enhance the network strength at early pyrolysis and pin up precursor-level functionalities on the final carbon. Such strategy successfully fixes more electroactive N (4.28−8.86 wt%) into the resultant carbon microspheres compared with non-pretreated carbon (2.89 wt%), as well as achieves broad ion-accessible platforms of 1575–2269 m2/g with preset structural superiorities. As a result, a typical acidic device reveals an outstanding specific capacitance of 383 F/g at 10 mV/s. Taking advantage of a novel LiNO3-PAM polymer electrolyte, the upgraded symmetric device displays the maximum specific capacitance of 229 F/g, along with a boosted energy density of 41.1 Wh/kg at 643.4 W/kg. This work opens up a feasible insight into realizing highly efficient precursor/electrode design toward superior system with outstanding energy/power feature and temperature applicability.
Cell stress responses are associated with numerous diseases including diabetes, neurodegenerative diseases, and cancer. Several events occur under cell stress, in which, are protein expression and organelle-specific pH fluctuation. To understand the lysosomal pH variation under cell stress, a novel NIR ratiometric pH-responsive fluorescent probe (BLT) with lysosomes localization capability was developed. The quinoline ring of BLT combined with hydrogen ion which triggered the rearrangement of π electrons conjugated at low pH medium, meanwhile, the absorption and fluorescent spectra of BLT showed a red-shifts, which gived a ratiometric signal. Moreover, the probe BLT with a suitable pKa value has the potential to discern changes in lysosomal pH, either induced by heat stress or oxidative stress or acetaminophen-induced (APAP) injury stress. Importantly, this ratiometric fluorescent probe innovatively tracks pH changes in lysosome in APAP-induced liver injury in live cells, mice, and zebrafish. The probe BLT as a novel fluorescent probe possesses important value for exploring lysosomal-associated physiological varieties of drug-induced hepatotoxicity.
The transdermal drug delivery (TDD) shows considerable advantages over other administration pathways. However, conventional enhancing permeation methods face a series of challenges owing to barrier function provided by the skin, of which enhancing abilities either are so strong that it results in toxicity and irritation, or too weak to achieve desirable therapeutical effects. To address these issues, it is an urgent need to develop a novel method to overcome the limitations of current measures. Fortunately, in the preceding decades, ionic liquids (ILs) have been extensively studied and increasingly applied in pharmaceutical drug delivery due to their unique physicochemical and biological properties. What is more, tunability of structure resolves the challenges in processing active pharmaceutical ingredient (API) formulation, such as polymorphism and poor solubility of drugs. Thus, the presence of ILs provides an ample design space for the transdermal drug delivery system (TDDS). This review discusses the shortcomings of conventional enhancing permeation methods and introduces the application of ILs in transdermal delivery from three aspects: ⅰ) ILs are applied as enhancers to weaken the barrier function of the stratum corneum (SC). ⅱ) As counterions, ILs are combined with API to modify the physicochemical properties of drugs. ⅲ) ILs assist in the design of transdermal preparation for perfecting formulation. This review comprehensively introduces the major breakthroughs made in the applications of ILs, which can serve as guidance to provide novel ideas for formulation scientists who hit the bottleneck in the development of TDD.
Trauma and neurosurgery often result in dural defects and are followed by serious complications or even death, finding suitable dural replacement materials to repair the defective dura has important clinical significance. Porcine peritoneal acellular matrix (PPAM) is a promising alternative material, but its poor stability makes it difficult to meet the various needs of dural reconstruction. In this work, we developed a novel antibacterial cross-linking agent oxidized quaternized guar gum (OQGG) and used it for the first time to stabilize PPAM to construct a dural mater substitute (OQGG-PPAM). The results showed that 1.5% OQGG-PPAM presented suitable mechanical property as well as good thermal stability and resistance to enzymatic degradation. It also exhibited good antibacterial activity and good anti-leakage ability. Furthermore, 1.5% OQGG-PPAM not only exhibited excellent cell compatibility but also significantly stimulated the secretion of bFGF and VEGF from seeded cells which was convenient for dural remodeling. In vivo experiment, it also exhibited the excellent histocompatibility and good anti-adhesion property. This study showed that OQGG can be used as a novel antibacterial cross-linking reagent for crosslinking natural tissues and 1.5% OQGG-PPAM was a potential candidate material for dura mater substitute.
Cancer is the leading cause that threatens human life expectancy due to the lack of effective therapies. Cancer immunotherapy has been explored to improve the body's immune system against cancer and accompanied by promising results in recent years. Interleukin 15 (IL-15), a pleiotropic immunomodulator, is critical for immune cells development and displays great anti-tumor potential in both preclinical and clinical trials. In this study, superagonist IL-15 plasmid (psIL-15) consisting of IL-15Rα-sushi-linker-IL-15 was constructed in order to secret superagonist IL-15 (sIL-15) in tumor site. A gene delivery system through self-assembly by methylated polyethylene glycol-b-polylactic acid-b-methylated polyethylene glycol (mPEG-PLA-mPEG) and 1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP), named DMAM, was designed to deliver psIL-15. Further study showed that DMAM/psIL-15 could successfully deliver psIL-15 to tumor cells and the supernatants of the tumor cells could further stimulate lymphocytes proliferation as well as activation in vitro. Local delivery of DMAM/psIL-15 in animal models demonstrated significant tumor inhibition through enhancing immune cells responses, reducing angiogenesis, promoting tumor cell apoptosis and inhibiting proliferation, with no evidence of system toxicities. These results indicate that DMAM/psIL-15 may be a promising strategy for cancer immunotherapy.
The macrocyclic family comprising pillar[n]arenes and cucurbit[n]urils have received much attention recently. However, studies on the construction of supramolecular complexes formed directly with derivatized pillar[n]arenes and cucurbit[n]urils are scant. Given the interest in such systems, herein we have synthesized a new type of naphthalene-derivatized pillar[n]arene NTP5 and selected Q[10] as the host molecule. The 4-[2-(1-naphthalenyl)ethenyl]pyridine of NTP5 is encapsulated by Q[10] and formed a host-guest complex in water-acetic acid (1:1) solution accompanied by enhanced fluorescence, which changed the morphology of NTP5 from a sphere to a porous form. In addition, the fluorescence of Q[10]-NTP5 can be quenched by the addition of the highly toxic pesticide paraquat (PQ), and the mechanism was shown to be the formation of a new charge transfer ternary system of Q[10]-NTP5-PQ. This work provides new ideas for the contribution of supramolecular assemblies based on derivatized pillar[n]arenes and their combination with cucurbit[n]urils and reveals their potential applications.
The development of out-of-equilibrium self-assembly systems using light as input fuel is highly desirable and promising for the fabrication of smart supramolecular materials. Herein, we report the construction of new artificial light-fueled dissipative molecular and macroscopic self-assembly systems based on a visible-light-responsive transient quadruple H-bonding array, which consists of an azobenzene-modified ureidopyrimidinone (UPy) module (Azo-O-UPy) and a nonphotoactive diamidonaphthyridine (DAN) derived competitive binder (Napy-1). The visible light (410 nm) irradiation can induce the E to Z isomerization of the azobenzene unit of E-Azo-O-UPy to produce Z-Azo-O-UPy with an opened UPy binding site, which can complex with Napy-1 to form a quadruply H-bonded heterodimer. The heterodimer is metastable and can be quickly disassembled in dark, owing to the fast thermal relaxation of Z-Azo-O-UPy to E-Azo-O-UPy. While introducing such transient quadruple H-bonding interaction into a linear polymer system or a polymeric gel system, light-fueled out-of-equilibrium polymeric assembly both at molecular and macro-scale can be achieved.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
