Latest ArticlesDiamide compounds such as chlorantraniliprole, a famous anthranilic diamide insecticide targeting the insect ryanodine receptor (RyR), have received continuous attention in pesticide research during the past 15 years owing to their excellent insecticidal potentials. With the aim of discovering new heterocyclic pesticides used for crop protection, based on the structural information of compound M from the reported pharmacophore-based virtual screening for RyR insecticides and diamide compound, a series of new heterocyclic mono-, di-, and tri-amide derivatives containing piperazine moiety have been synthesized in this paper. The new compounds were identified and confirmed by melting point, 1H NMR, 13C NMR and HRMS. Compound M was firstly validated for insecticidal activities, and the new synthesized compounds were all made comprehensive insecticidal evaluations against diamondback moth and oriental armyworm. The bioassay results showed that some of the compounds exhibit favorable insecticidal potentials, particularly some novel piperazine-containing heterocyclic mono-/di-/tri-amide derivatives such as 8g, 14a, 15a, 15g, 15i, 15j, 15k, 15l, and 15m could be used as new insecticidal leading structures for further study (e.g., towards diamondback moth, 15i-15m LC50: 0.0022−0.0081 mg/L). The structure-activity relationships of the compounds discussed in detail provide useful guidance for further design and development of new insecticides.
Tumor drug resistance and systemic side effects of chemotherapeutic drugs are the main reasons for the failure of cancer treatment. In recent years, it was found that some natural active ingredients can reverse MDR and regulate body immunity to enhance the efficacy and reduce toxicity of chemotherapeutic drugs. In this paper, a new nanosuspensions, HCPT and QUR hybrid nanosuspensions (HQ-NPs), was prepared by the microprecipitation-high pressure homogenization method to reverse tumor drug resistance, reduce toxicity, and increase therapeutic efficacy. The in vitro investigation results showed that HQ-NPs had a unique shape (particle size was about 216.3±5.9 nm), changed crystalline, and different dissolution rates compared with HCPT-NPs and QUR-NPs, which is attributed to the strong intermolecular forces between HCPT and QUR as indicated by the results of the molecule dock. It was verified that the HQ-NPs could double the retention of HCPT in cells and enhance the cytotoxicity to A549/PTX cells in vitro tests compared with HCPT-NPs. We also found that HQ-NPs can significantly enhance the accumulation of HCPT in tumor sites, improve the antitumor activity of HCPT, and protect the immune organs and other normal tissues (P < 0.01), compared with HCPT-NPs. Therefore, hybrid nanosuspensions can offer promising potential as the drug delivery system for HCPT and QUR to increase the therapeutic efficacy and reduce the toxicity of HCPT.
Electrochemical oxidation of water to produce highly reactive hydroxyl radicals (OH) is the dominant factor that accounts for the organic compounds removal efficiency in water treatment. As an emerging carbon-based material, the investigation of electrocatalytic of water to produce OH on Graphdiyne (GDY) anode is firstly evaluated by using first-principles calculations. The theoretical calculation results demonstrated that the GDY anode owns a large oxygen evolution reaction (OER) overpotential (ηOER=1.95 V) and a weak sorptive ability towards oxygen evolution intermediates (HO*, not OH). The high Gibbs energy change of HO* (3.18 eV) on GDY anode makes the selective production of OH (ΔG=2.4 eV) thermodynamically favorable. The investigation comprises the understanding of the relationship between OER to electrochemical advanced oxidation process (EAOP), and give a proof-of-concept of finding the novel and robust environmental EAOP anode at quantum chemistry level.
In comparison with lithium-ion batteries (LIBs) with liquid electrolytes, all-solid-state lithium batteries (ASSLBs) have been considered as promising systems for future energy storage due to their safety and high energy density. As the pivotal component used in ASSLBs, composite solid polymer electrolytes (CSPEs), derived from the incorporation of inorganic fillers into solid polymer electrolytes (SPEs), exhibit higher ionic conductivity, better mechanical strength, and superior thermal/electrochemical stability compared to the single-component SPEs, which can significantly promote the electrochemical performance of ASSLBs. Herein, the recent advances of CSPEs applied in ASSLBs are presented. The effects of the category, morphology and concentration of inorganic fillers on the ionic conductivity, mechanical strength, electrochemical window, interfacial stability and possible Li+ transfer mechanism of CSPEs will be systematically discussed. Finally, the challenges and perspectives are proposed for the future development of high-performance CSPEs and ASSLBs.
Gold nanoparticles (Au NPs) are nanoscale sources of light and electrons, which are highly relevant for their extensive applications in the field of photocatalysis. Although a number of research works have been carried out on chemical reactions accelerated by the energetic hot electrons/holes, the possibility of reaction pathway change on the plasmonic Au surfaces has not been reported so far. In this proof-of-concept study, we find that Au NPs change the reaction pathway in photooxidation of alkyne under visible light irradiation. This reaction produces benzil (-CO-CO-) without the presence of Au NPs. In contrast, as indicated by surface-enhanced Raman spectroscopic (SERS) results, the C-C triple bonds (-C≡C-) adsorbed on Au NPs are converted into carboxyl (-COOH) and acyl chloride (-COCl) groups. The plasmonic Au NPs not only provide energetic charge carriers but also activate the reactant molecules as conventional heterogeneous catalysts. This study discloses the second role of plasmonic NPs in photocatalysis and bridges the gap between plasmon-driven and conventional heterogeneous catalysis.
A self-synthesized bi-pyridine chelating resin (PAPY) could separate Cu(Ⅱ)/Ni(Ⅱ)/Fe(Ⅱ) sequentially from strong-acidic pickling wastewater by a two-stage pH-adjusted process, in which Cu(Ⅱ), Ni(Ⅱ), and Fe(Ⅱ) were successively preferred by PAPY. In the first stage (pH 1.0), the separation factor of Cu(Ⅱ) over Ni(Ⅱ) reached 61.43 in Cu(Ⅱ)-Ni(Ⅱ)-Fe(Ⅱ) systems. In the second stage (pH 2.0), the separation factor of Ni(Ⅱ) over Fe(Ⅱ) reached 92.82 in Ni(Ⅱ)-Fe(Ⅱ) systems. Emphasis was placed on the selective separation of Cu(Ⅱ) and Ni(Ⅱ) in the first-stage. The adsorption amounts of Cu(Ⅱ) onto PAPY were 1.2 mmol/g in the first stage, while those of Ni(Ⅱ) and Fe(Ⅱ) were lower than 0.3 mmol/g. Cu(Ⅱ) adsorption was hardly affected by Ni(Ⅱ) with the presence of dense Fe(Ⅱ), but Cu(Ⅱ) inhibited Ni(Ⅱ) adsorption strongly. Part of preloaded Ni(Ⅱ) could be replaced by Cu(Ⅱ) based on the replacement effect. Compared with the absence of Fe(Ⅱ), dense Fe(Ⅱ) could obviously enhance the separation of Cu(Ⅱ)-Ni(Ⅱ). More than 95.0% of Cu(Ⅱ) could be removed in the former 240 BV (BV for bed volume of the adsorbent) in the fixed-bed adsorption column process with the flow rate of 2.5 BV/h. As proved by X-ray photoelectron spectrometry (XPS) and density functional theory (DFT) analyses, Cu(Ⅱ) exerted a much stronger deprotonation and chelation ability toward PAPY than Ni(Ⅱ) and Fe(Ⅱ). Thus, the work shows a great potential in the separation and purification of heavy metal resources from strong-acidic pickling wastewaters.
As organic pollutants of emerging concern, organophosphate esters (OPEs) have shown toxicity to organisms after entering the water environment. However, research on OPEs in freshwater in Southwest China is very limited. The levels, distribution and partitioning behavior of OPEs in the Minjiang River and their influencing factors is still unknown. In this study, six OPEs, tri-n-butyl phosphate (TnBP), tri(2-chloroethyl)-phosphate (TCEP), trichloropropyl phosphate (TCPP), triphenyl phosphate (TPhP), tributoxyethyl phosphate (TBEP), and tris(2-ethylhexyl)-phosphate (TEHP), were determined in surface water, suspended particle matter (SPM) and sediments of the Minjiang River. The results showed that the average concentrations of Σ6OPEs in surface water, SPM and sediments of the Minjiang River were 199.32±124.95 ng/L, 38463.79±45641.89 ng/g dry weight (dw) and 76.45±28.00 ng/g dw, respectively. High concentrations of OPEs were detected in SPM samples, indicating that more attention should be paid to pollution in SPM. It is worth noting that the variation trend of OPEs in SPM was almost opposite to that in water but basically similar to that in sediment. The proportions of alkyl OPEs in Σ6OPEs increased from surface water to SPM and sediments. Alkyl OPEs were the main pollutants in SPM (10.44%–80.88% of Σ6OPEs, mean of 54.52%) and sediments (59.08%–81.30% of Σ6OPEs, mean of 68.91%), whereas chlorinated OPEs were the most abundant components in surface water (43.16%–75.99% of Σ6OPEs, mean of 55.50%). The water-sediment partition coefficient (logKOC) of OPEs was 4.97–7.58, while the water-SPM partition coefficient was 6.71–10.00. No significant correlations were found between logKOW and logKOC. KOW was not the main factor affecting the distribution of OPEs in the Minjiang River, China.
Recent advances in the desilylative acylation of 1-alkenylsilanes with acid anhydrides under transition metal catalysis are summarized. This catalytic desilylative acylation of 1-alkenylsilanes provides an efficient route to α, β-unsaturated ketones by using rhodium or iridium as the catalyst. Moreover, various one pot sequence reactions have been developed, which can synthesize α, β-unsaturated ketones from simple starting materials in an economic way. Additionally, this approach is applied to the asymmetric synthesis of atropisomers possessing silanol groups with excellent enantioselectivity.
Carbon dots (CDs) are metal-free fluorescent materials that can be used in optical and electronic devices, but few studies have focused on one-step synthesis routes for CDs with tunable color and high photoluminescence quantum yield (PLQY). Herein, CDs with tunable light emission were synthesized using a novel amide-assisted solvothermal approach. The as-prepared CDs were well dispersed and homogeneous, with average diameters of approximately 2.0–4.0 nm, depending on the dopants. Owing to the surface states with different ratios of nitrogen- and oxygen-related species, different CDs can exhibit blue, green, red, or white emission with relatively high PLQYs of 61.6%, 41.3%, 29.1% and 19.7%, respectively. XPS measurements, in conjunction with DFT calculations, indicate that nitrogen substitution (pyridinic/pyrrolic nitrogen) dominates the blue emission, while introducing oxygen functional groups lowered the LUMO energy level, which resulted in redder emission. In addition, the CDs are demonstrated as a bioimaging probe in bothin vitro and in vivo assays, and the white light CDs have been demonstrated to be potential fluorescent materials for white-light-emitting diode (WLED).
In the field of volatile organic compounds (VOCs) pollution control, adsorption is one of the major control methods, and effective adsorbents are desired in this technology. In this work, the density functional theory (DFT) calculations are employed to investigate the adsorption of typical VOCs molecules on the two-dimensional material borophenes. The results demonstrate that both structure of χ3 and β12 borophene can chemically adsorb ethylene and formaldehyde with forming chemical bonds and releasing large energy. However, other VOCs, including ethane, methanol, formic acid, methyl chloride, benzene and toluene, are physically adsorbed with weak interaction. The analysis of density of states (DOS) reveals that the chemical adsorption changes the conductivity of borophenes, while the physical adsorption has no distinct effect on the conductivity. Therefore, both χ3 and β12 borophene are appropriate adsorbents for selective adsorption of ethylene and formaldehyde, and they also have potential in gas sensor applications due to the obvious conductivity change during the adsorption.