Enterovirus 71 (EV71) infection is known to cause hand, foot, and mouth disease (HFMD), which is associated with neurological complications; however, there is currently no effective treatment for ...this infection. Flavonoids are a large group of naturally occurring compounds with multiple bioactivities, and the inhibitory effects of several flavonoids against EV71 have been studied in cell cultures; however, to date, there are no reported data on their effects in animal models. In this study, we confirmed the in vitro activities of eight flavonoids against EV71 infection, based on the inhibition of cytopathic effects. Moreover, these flavonoids were found to reduce viral genomic RNA replication and protein synthesis. We further demonstrated the protective efficacy of these flavonoids in newborn mice challenged with a lethal dose of EV71. Apigenin, luteolin, kaempferol, formononetin, and penduletin conferred survival protection of 88.89%, 91.67%, 88.89%, 75%, and 66.67%, respectively, from the lethal EV71 challenge. In addition, isorhamnetin provided the highest mice survival protection of 100% at a dose of 10 mg/kg. This study, to the best of our knowledge, is the first to evaluate the in vivo anti-EV7l activities of multiple flavonoids, and we accordingly identified flavonoids as potential leading compounds for anti-EV71 drug development.
Trivalent copper complexes are active intermediates in aquatic redox reactions that involve copper ions or structural copper, but their reactivity and selectivity toward pollutants remain unknown. We ...characterized copper(III) periodate, a representative trivalent copper compound, with phenol and several antibiotics as model contaminants. The results show that Cu(III) is highly reactive to phenol degradation; near-complete degradation was achieved after 10 min at a molar ratio of 3:1 (CuIII: phenol). Common alcohols, including methanol and 2-propanol, showed pH-dependent reactivity for Cu(III). In contrast to aquo trivalent copper ions that react rapidly with tert-butanol, Cu(III) showed limited reactivity toward tert-butanol. A mechanistic investigation showed that the degradation was caused by direct oxidation by Cu(III) and that no hydroxyl radicals were involved. Common water components such as chloride ions did not influence the reaction, which suggests that the use of Cu(III) may help mitigate the generation of chlorinated products. As a one-electron oxidant, Cu(III) showed high reactivity to degrade electron-rich compounds; the concentrations of sulfamethazine, sulfamethoxazole, and sulfadiazine (100 μg/L) were reduced to 1.8, 7.5, and 42.5 ng/L, respectively, after 2 min of reaction with 10 μM Cu(III). These results demonstrate a novel and highly efficient oxidant for selective removal of ubiquitous micropollutants from water bodies.
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•Cu(III) was used to degrade a variety of contaminants.•The reactivity and selectivity of Cu(III) were investigated.•No hydroxyl radicals were involved in the degradation by Cu(III).•Cu(III) showed high reactivity to degrade electron-rich compounds.•Common water components such as chloride ions did not influence the degradation.
•Pyrite-peroxymonosulfate exhibited high 1,4-dioxane degradation activity.•Pyrite acted as a slow-release source of ferrous iron to activate peroxymonosulfate.•Radicals were generated and recorded by ...electron paramagnetic resonance.•The disulfide in pyrite played a significant role in the release of ferrous iron.•Chloride and bicarbonate ions had no obvious effects on pyrite-peroxymonosulfate.
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The controlled generation of radicals is an effective way to improve the stoichiometric efficiency of oxidants, particularly when treating highly recalcitrant contaminants. In this study, an innovative oxidation system was used to degrade extremely recalcitrant 1,4-dioxane. This system was based on a combination of pyrite, an abundant mineral used as a slow-release source of iron, and peroxymonosulfate (PMS). In addition, other oxidants, including hydrogen peroxide and peroxydisulfate, and their conditions were examined. PMS had the highest degradation performance of the oxidants tested. Near-100% degradation of 1,4-dioxane (50 mg L−1) was achieved after 40 min using PMS; the corresponding degradation rates with peroxydisulfate and hydrogen peroxide were around 50% and 15%, respectively. The production of hydroxyl radicals and sulfate radicals by pyrite-activated PMS was confirmed by electron paramagnetic resonance. Neither solid pyrite nor dissolved Fe2+ or Fe3+ was directly involved in the degradation. Instead, the Fe2+ generated from pyrite oxidation activated PMS homogeneously. Quenching tests and the rapid degradation of nitrobenzene show that hydroxyl radicals were the major active species produced by pyrite-PMS. In contrast to the significant scavenging effect of Cl− (3.0 mM) on Co2+-PMS, no significant Cl− (≤10 mM) scavenging was observed on pyrite-PMS. These results suggest that the use of pyrite-PMS mitigates the scavenging effects of Fe2+ and Cl−, and, therefore, may increase the application of iron-based materials and PMS in the water treatment industry.
In this work, hydroxyl-functionalized boron nitride nanosheet (OH-BNNS) was prepared and was blended with poly(l-lactide) (PLLA) to yield PLLA/OH-BNNS nanocomposites with excellent dispersion of ...OH-BNNS via the interaction of carbonyl in PLLA and hydroxyl in OH-BNNS. The effects of OH-BNNS on the crystallization and melting behaviors, isothermal crystallization kinetics, macroscopic crystal morphology and crystal structure of PLLA were studied by means of various techniques. The addition of OH-BNNS nanofillers can effectively accelerate the crystallization of PLLA and enhance the nucleation density, leading to a smaller spherulite size, increased crystallinity, a more obvious crystallization peak upon cooling but weakened cold crystallization behavior upon heating. Low OH-BNNS loading can increase the relative content of α-crystal, but the relative content of less perfect α'-crystal is increased at high OH-BNNS loading due to the strong interaction between PLLA and OH-BNNS.
The water vapor budget (WVB) over the Tibetan Plateau (TP) is closely related to the large-scale atmospheric moisture transportation of the surrounding mainland and oceans, especially for the ...Indo-Pacific warm pool (IPWP). However, the procession linkage between the WVBs over the TP and its inner basins and IPWP has not been sufficiently elucidated. In this study, the relationship between the summer WVB over the TP and the IPWP was quantitatively investigated using reanalysis datasets and satellite-observed sea surface temperature (SST). The results show that: (1) the mean total summer vapor budget (WVBt) over the TP in the period of 1979–2018 was 72.5 × 106 kg s−1. Additionally, for the 13 basins within the TP, the summer WVB has decreased from southeast to northwest; the Yarlung Zangbo River Basin had the highest WVB (33.7%), followed by the Upper Yangtze River Basin, Ganges River Basin and Qiangtang Plateau. (2) For the past several decades, the WVBt over the TP has experienced an increasing trend (3.81 × 106 kg s−1 decade−1), although the southern boundary budget (WVBs) contributed the most and is most closely related with the WVBt, while the eastern boundary budget (WVBe) experienced a decreasing trend (4.21 × 106 kg s−1 decade−1) which was almost equal to the interdecadal variations of the WVBt. (3) For the IPWP, we defined a new warm pool index of surface latent heat flux (WPI-slhf), and found that an increasing WPI-slhf would cause an anticyclone anomaly in the equatorial western Indian Ocean (near 70° E), resulting in the increased advent of water vapor to the TP. (4) On the interdecadal scale, the correlation coefficients of the variation of the summer WVBt over the TP with the WPI-slhf and Indian Ocean Dipole (IOD) signal were 0.86 and 0.85, respectively (significant at the 0.05% level). Therefore, the warming and the increasing slhf of the IPWP would significantly contribute to the increasing WVB of the TP in recent decades.
•An effective clean up method using SPE and sulphuric acid has been developed.•Recovery values for the majority of pesticides ranged from 70% to 110%.•The validated method was successfully applied in ...Alpinia oxyphylla samples.•Four pesticides were detected in three samples and confirmed by GC–MS.•No pesticide residues exceeded the MRLs set by the European Pharmacopoeia.
A simple and effective multi-residue method was developed and validated for the analysis of 26 organochlorine pesticide residues in Alpinia oxyphylla by a gas chromatography with an electron capture detector (GC-ECD). The target pesticides were extracted by sonication and cleaned up with florisil solid phase extraction and sulphuric acid. Some crucial parameters, including extraction solvent and time, sorbent type, elute solvent and concentration of sulphuric acid were optimized to improve the performance of sample preparation procedure. The optimized method gave high sensitivity with detection limit ranging from 0.1 to 2.0μg/kg. Matrix-matched calibration was employed for the quantification, and a wide linear range (from 1.0 to 1000μg/kg) with r2 values ranging from 0.9971 to 0.9998 was obtained. For the majority of the tested pesticides, the average recoveries were in acceptable range (between 70% and 110%) with relative standard deviation values below 15.0%. Matrix effect was evaluated for target compounds through the study of ratio of peak area obtained in the solvent and blank matrix. The proposed method was applied to simultaneously analyze 26 pesticides in 55 batches of Alpinia oxyphylla samples. 3 samples were found to be positive with four pesticides (α-BHC, quintozene, trans-chlordane and op'-DDD), which were confirmed by gas chromatography-mass spectrometry (GC–MS) in selective ion monitoring (SIM) mode.
In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of ...molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross-linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio-matrix samples.
A bottom-up and wet-chemical method employing l -cysteine as a precursor has been proven to be an effective strategy for producing fluorescent porous CQDs for the first time, which exhibit stable and ...strong photoluminescence, and reach a quantum yield of 18.1%. Under optimum conditions, a good linear semilogarithmic correlation between the quenching efficiency ( F 0 / F ) and the concentration of chromium ions, even at 10 −8 mol L −1 , was achieved, and the limit of detection was 1.491 × 10 −9 mol L −1 . The quenching of the porous CQDs’ fluorescence intensity by Cr 6+ may result from the inner filter effect. The application of these porous CQDs as probes for the detection of chromium ions is good, and they can be readily, rapidly and efficiently employed in the natural environment.
Obesity continues to be a global public health challenge.
seed is rich in bioactive ingredients with pharmacological effects, such as hypoglycemic activity and anti-oxidation. This study aimed to ...assess the potential anti-obesity effects of
seed and the changes of gut microbiota and mycobiota compositions in obese zebrafish induced by a high-fat diet. The anti-obesity effects were supplemented and validated in high-fat diet-induced obese mice. In this study, various chemical components of
seed water and ethanol extracts were detected using UHPLC-QE-MS, and both extracts showed strong
antioxidant activities. Network pharmacology analysis showed the potential of the extracts to improve obesity.
seed powder, water and ethanol extracts decreased the weight of obese zebrafish, improved lipid accumulation and lipid metabolism, regulated appetite, and inhibited cell apoptosis and inflammation of the liver and intestine. They showed similar effects in obese mice, and also reduced the weight of fat tissues, regulated insulin resistance and glucose metabolism, and improved the intestinal barrier. Additionally,
seed modulated the compositions of gut microbiota and mycobiota in zebrafish, with the regulation of the proportion of bacteria that produce short-chain fatty acids or affect intestine health, including
,
,
,
, and Micrococcaceae, and the proportion of fungi that produce mycotoxins or have special metabolic capacities, including
,
,
, and
. Spearman's correlation analysis revealed the potential link between zebrafish obesity parameters, gut bacteria and fungi. Overall, these findings indicated that
seed effectively improved obesity.
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