Latest ArticlesExosome, which is a kind of extracellular vesicles with size around 40-160 nm, plays an important role in cell-to-cell communication in multiple diseases. Especially in tumor microenvironment, exosomes are the important pathway to transit proteins, nucleic acids and small molecules between different kinds of cells. Based on these characteristics, exosomes are served as both therapeutic agents and drug delivery systems in cancer therapy. In this review, the applications of exosomes as drug delivery systems in cancer therapy were summarized and classified according to the cell source of the exosomes, including normal cells, immune cells and tumor cells. Different modifications of exosomes and drug loading methods were presented. Finally, some challenges that hindered the clinical translation of exosomes were also discussed.
One-dimensional carbon nanofibers are widely applied as anode material in the energy storage field due to its unique structure and high conductivity. In this work, one-dimensional ZnSe@N-doped carbon nanofibers (ZnSe@NC NFs) are successfully synthesized by electrospinning and annealed without extra troublesome conditions. ZnSe nanocrystals are enfolded in the N-doped carbon nanofibers, which can act as a protective layer to avoid the volume expansion of active material and promote ion transport during the cycling process. More importantly, the as-synthesized ZnSe@NC NFs are served as the anode material and display the admirable storage properties for Na/K-ion batteries. The one-dimensional ZnSe@NC NFs material shows the high capacity of 237 mAh/g for Na-ion batteries at a current density of 1 A/g for 2000 cycles. Meanwhile, it also delivers a high discharge capacity of 337 mAh/g for K-ion batteries at 0.2 A/g for 300 cycles. Additionally, it is confirmed that the pseudocapacitive contribution of the nano-structure material is up to 54.5% at a scan rate of 0.6 mV/s through the cyclic voltammetry (CV) measurement in K-ion batteries.
Photocatalytic recovery, a novel precious metal recycling technology, dedicates to solving the environmental and energy consumption problems caused by traditional technologies. The activation of molecular oxygen (O2) is one of the most critical steps in the whole process. Herein, we regulated the different adsorption intensity of oxygen on the surface by designing phosphate (PO43−) modified titanium oxide (TiO2). The results show that the adsorption of oxygen on the photocatalyst surface is gradually enhanced, which effectively improves the dissolution rate of precious metals. PO43− modification increased the photocatalytic dissolution rate of gold (Au) by 2.8 times. The photocatalytic activity of other precious metals dissolution (such as palladium (Pd), platinum (Pt), rhodium (Rh), ruthenium (Ru) and iridium (Ir)) was also significantly improved. It is applied to the recovery of precious metals from spent catalysts and electronic devices to significantly promote the recovery efficiency. This indicates the direction for designing more efficient photocatalysts for precious metal recovery.
Hydroxyl radicals (•OH) generated on anode play a vital role in electrochemical oxidation (EO) of organic pollutants for water treatment. Inspired by the four-electron oxygen evolution reaction (OER), we supposed an anode-selection strategy to stabilize deeply oxidized states (*O and *OOH) which are beneficial to generating •OH. To verify the hypothesis, a candidate anode component (MIL-101(Cr), a well-known metal-organic framework with active variable-valence transition metal centers) was used to coat Ti/TiO2 plate to fabricate anodes. Compared to TiO2(101) plane on undecorated anode surface, fast and complete removal of aniline and phenol, and improved energy utilization were achieved on MIL-101(Cr)-coated-Ti/TiO2 anode. Mechanism investigation, including pollutant degradation pathways, showed the predominate contribution (69.60%–75.13%) of •OH in pollutant mineralization. Density functional theory (DFT) computations indicated Cr site in MIL-101(Cr) was more conducive to stabilizing *O and *OOH, leading to thermodynamical spontaneous generation of •OH. This work opens up an exciting avenue to explore •OH production, and supplies a useful guidance to the development of anode materials for EO process.
A series of DL-serine covalently modified multinuclear lanthanide implanted arsenotungstates K2[{Ln(H2O)7}2{As4W44O137(OH)18(H2O)2(DL-Ser)2}{Ln2(H2O)5(DL-Ser)}2]·65H2O (DL-Ser = DL-serine, Ln = La (1), Ce (2), Pr (3)) are obtained. Crystal structure analysis shows that these compounds are isomorphic and contain the basic [{As4W44O137(OH)18(H2O)2(DL-Ser)2}{Ln2(H2O)5(DL-Ser)}2]8– polyoxoanion constituted by two {As2W19O59(OH)8(H2O)}6‒ subunits, a [W6O23(OH)2(DL-Ser)2]14‒ fragment, and two embedded [Ln2(H2O)5(DL-Ser)]5+ groups, which further build into one dimensional linear chainlike structure via two peripheral Ln3+ ions. Most remarkably, these compounds exhibit rapid photochromic behaviors, which changed color quickly from white (1), yellow (2), green (3) to blue (1), brown (2) and glaucous (3) in ten minutes under UV irradiation, and that the colors gradually recovered in the dark for approximately 22 h.
The freshness of seafood can be judged by detecting the concentration of triethylamine (TEA). In this work, 2D CuO porous nanosheets (CuO PNs) were prepared by a graphene oxide template method and their particle sizes were regulated by changing the calcination temperature. Their structure, morphology and gas sensing performances were investigated by various characterization methods. The response (Rg/Ra) of the gas sensor based on CuO PNs calcined at 700 ℃ was as high as 440-100 ppm TEA at the operating temperature of 40 ℃. The detection limit was as low as 0.25 ppm. In addition, the gas sensor has good selectivity and stability. The excellent TEA sensitivity is mainly resulted from the appropriate particle size and loose porous framework. This work not only paves the way to explore the novel low temperature TEA gas sensors, but also provides deep insight on improving the structure and properties of gas sensitive materials by controlling the calcination temperature.
The conversion of carbon dioxide into useful fuels or chemical feedstocks is of great importance for achieving carbon emission peak and carbon neutrality. The harvesting and conversion of solar energy will provide a sustainable and environmentally friendly energy source for human production and living. Very recently, photothermal catalysis has been proved to exhibit great advantages in reducing the reaction temperature, promoting the catalytic activity, and manipulating the reaction pathway in comparison with traditional thermal catalysis. In this review, we firstly introduced the fundamental mechanisms and categories of photothermal catalysis to understand the synergy or the difference between photochemical and thermochemical reaction pathways. Subsequently, the criteria and strategies for photothermal catalyst design are discussed in order to inspire the development of high-efficiency photothermal catalytic route by achieving intense absorption of broadband solar energy spectrum and high conversion capability of solar-to-heat. Recent progress in CO2 reduction achieved by photothermal catalysis was summarized in terms of production types. In the end, the future challenges and perspectives of photothermal catalytic CO2 reduction are presented. We hope that this review will not only deepen the understanding of photothermal catalysis, but also inspire the design, preparation and application of high-performance photothermal catalysts, aiming at alleviating non-renewable fossil energy consumption and carbon emissions for early carbon emission peak and carbon neutrality.
Defect-rich, highly porous two-dimensional carbon nanosheets (CNS) have attracted tremendous research interests in catalysis and environmental purification and other fields, because of their unique micromorphology, chemical stability and high specific surface area. Herein, in this work, we report a new solution to synthesize an ultrathin two-dimensional CNS with rich defects and abundant pores via two-step etching the Ti3AlC2 with the help of I2 and NaOH. The CNS thickness, specific surface area and pore volume could be all tunable by adding the amount of I2. And the highest specific surface area and pore volume of the synthesized 2D CNS can be achieved 1134.4 m2/g and 0.80 cm3/g, with a thickness of only 0.64 nm and a yield of 35.9%. When employed as the anodes for lithium-ion batteries, the synthesized CNS anodes exhibit good cycling and rate capabilities. This work provides a novel and facile strategy for synthesizing highly porous and defective 2D carbon materials with good lithium storage properties.
Exosome and inclusive cargoes have manifested significant function in different biological events. In particular, glycopeptides in exosome are closely associated with occurrence and development of various diseases. Developing advanced tools is highly desired to enrich glycopeptides from exosomes, and enrich exosomes from complex biological samples as well. In this work, integration of L-cysteine and titania onto the surface of magnetic nanoparticles is designed to realize the coefficient affinity towards exosomes and inclusive glycopeptides. Benefiting from the synergistic affinity, we separate exosomes from human urine concentrate directly, which was proved by the detection of three typical antigen markers of exosomes. Furthermore, hardly any exosomes remained on materials after ultrasonication, which confirmed the good capture performance of Fe3O4@TiO2@L-Cys and high release effect of direct lysis. Moreover, 146 glycopeptides corresponding to 77 glycoproteins were successfully identified from captured exosomes. These satisfactory results will inspire more efforts to be devoted to this field and will be extremely helpful to in-depth information excavation of biological markers, especially disease-related ones, through exosomes and inclusive glycopeptides.
Acetylene (C2H2) and ethylene (C2H4) both are important chemical raw materials and energy fuel gasses. But the effective removement of trace C2H2 from C2H4 and the purification of C2H2 from carbon dioxide (CO2) are particularly challenging in the petrochemical industry. As a class of porous physical adsorbent, metal-organic frameworks (MOFs) have exhibited great success in separation and purification of light hydrocarbon gas. Herein, we rationally designed four novel MOFs by the strategy of pore space partition (PSP) via introducing triangular tri(pyridin-4-yl)-amine (TPA) into the 1D hexagonal channels of acs-type parent skeleton. By modulating the functional groups of linear dicarboxylate linkers for the parent skeleton, a series of isoreticular PSP-MOFs (SNNU-278−281) were successfully obtained. The synergistic effects of suitable pore size and Lewis basic functional groups make these MOFs ideal C2H2 adsorbents. The gas adsorption experimental results show that all MOFs have excellent C2H2 uptakes. Specially, SNNU-278 demonstrates a high C2H2 uptake of 149.7 cm3/g at 273 K and 1 atm. Meanwhile, SNNU-278−281 MOFs also show extremely great C2H2 separation from CO2 and C2H4. The optimized SNNU-281 with high-density hydroxy groups exhibits extraordinary C2H2/CO2 and C2H2/C2H4 dynamic breakthrough interval times up to 31 min/g and 17 min/g under 298 K and 1 bar.