As a hot candidate for marine pollution control, electrocatalytic oxidation strongly depends on the characteristics of anode materials. Even though emerging 2D metal-organic frameworks ...(2D-MOFs)/graphene oxide (GO) complex has satisfied the conductive and tunable requirements of anode, electrocatalytic efficiency still needs to be improved by maximizing the electron carriers or shuttles. Herein, we capitalized upon crosslinking heteroatoms as pointcut to adjust the electron distribution, mobility, and transfer orientation in 2D-MOFs/GO. As a result, Ni3(BHT)2/2GO (metal centers: Ni; crosslinking heteroatoms: S), which was much higher than materials with metal centers of Cu or crosslinking heteroatoms of N, achieved superior conductivity and 100% tetracycline hydrochloride removal within 12 min. In Ni3(BHT)2/2GO, Ni ions and S atoms cooperated as electron shutters rather than isolated active center and granted accelerated electron transfer from 2D-MOFs to GO layers. Furthermore, Ni sites and S crosslinking heteroatoms exhibited superior activity for ⋅O2− and ⋅OH generation, whereas 1O2 depended more on C and O substrates. All experiments, theory calculations, and application expanding approved the practice feasibility of 2D-MOFs/GO in electrocatalytic oxidation by adjusting crosslinking heteroatoms. All these results provided new perspectives on the micro-molecular regulation for improving electrocatalytic efficiency.
Display omitted
•Ni and S atoms in Ni3(BHT)2/2GO act as cooperators rather than direct active centers.•Electron transfers from MOF to GO layers.•High electron-seizing potential of S atoms accelerate the electron transfer.
Redox-active organic cathode materials have drawn growing attention because of the broad availability of raw materials, eco-friendliness, scalable production, and diverse structural flexibility. ...However, organic materials commonly suffer from fragile stability in organic solvents, poor electrochemical stability in charge/discharge processes, and insufficient electrical conductivity. To address these issues, using Cu(II) salt and benzenehexathiolate (BHT) as the precursors, we synthesized a robust and redox-active 2D metal–organic framework (MOF), Cu3(C6S6) n , namely, Cu-BHT. The Cu-BHT MOFs have a highly conjugated structure, affording a high electronic conductivity of 231 S cm–1, which could further be increased upon lithiation in lithium-ion battery (LIB) applications. A reversible four-electron reaction reveals the Li storage mechanism of the Cu-BHT for a theoretical capacity of 236 mAh g–1. The as-prepared Cu-BHT cathode delivers an excellent reversible capacity of 175 mAh g–1 with ultralow capacity deterioration (0.048% per cycle) upon 500 cycles at a high current density of 300 mA g–1. Therefore, we believe this work would provide a practical strategy for the development of high-power energy storage materials.
The present study compares, theoretically and experimentally, the antiradical potential of four most commonly used antioxidants, namely butylated hydroxytolune (BHT), butylated hydroxyanisole (BHA), ...ascorbic acid (Asc) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). The antiradical activity was evaluated in vitro using DPPH and ABTS assays. DFT calculations at B3LYP/6-311G(d,p) level of theory have been employed to evaluate theoretically the antiradical potential of the investigated compounds in gas phase, ethanol and water. The three well-established antiradical mechanisms, hydrogen atom transfer (HAT), sequential electron transfer proton transfer (SETPT) and sequential proton loss electron transfer (SPLET) have been investigated. The results allowed assigning the antiradical activity to specific moieties and structural features of these compounds. It was found that for Asc the hydroxyl group (4-OH) is the most likely to be abstracted to form radicals and hence define antiradical properties of this compound. For BHA, the isomer 2-BHA is a better antiradical agent than the isomer 3-BHA. The H-benzylic of Trolox contributes to its antiradical properties. For all the studied compounds the HAT was found to be the thermodynamically dominant mechanism in gas-phase, whereas the SPLET mechanism is the thermodynamically favorable pathway in polar solvents. Both experimental and theoretical results indicate that the sequence of the antiradical potential of the investigated compounds is BHT > BHA > Trolox > Asc.
Display omitted
•A comparative study of the antiradical properties of Ascorbic Acid, BHT, BHA and Trolox have been carried out.•DPPH and ABTS assays were employed in order to investigate experimentally the antiradical properties of the studied compounds.•HAT, SPLET and SETPT mechanisms have been investigated by means of DFT calculations.•HAT was found to be the thermodynamically preferred mechanism in the gas phase, whereas SPLET in ethanol and water.•The sequence of the antiradical potential of the investigated compounds was found to be BHT > BHA > Trolox > Asc.
This study determined the effect of lead-cadmium toxicity in the liver of albino rats. 56 rats were divided into 7 groups of 8 rats each and were treated as follows : Group A Control (1 ml of diluent ...(corn oil); Group B (15mg/kg BW cadmium); Group C(50mg/kg BW lead); Group D (15mg/kg BW Cadmium and 50mg/kg BW lead); Group E (15mg/kg BW cadmium, 50mg/kg BW lead and 23mg/kg BW vitamin E);Group F (15mg/kg BW cadmium, 50mg/kg BW lead and 25mg/kg BW Butylated HydroxylToluene) and Group G (15 mg/kg BW Cd+50mg/kg BW lead+25mg/kg BW (BHT + vitamin E). Rats were sacrificed on the 29th and 56th day in sub-acute and chronic exposure respectively. Liver function, oxidative stress markers and histological examination were carried out. Results indicate that rats exposed to cadmium and lead suffered liver damage due to the significant (P<0.05) increase in Alanine Transferase, Aspartate transferase and Alkaline phosphatase, and significant decrease (P<0.05) in Total Protein and Albumin in the serum. Malonaldehyde (MDA) levels were also significantly increased (P<0.05) with a concomitant decrease in Superoxide dismutase, catalase and Glutathione peroxidase activities in both the chronic and acute exposure phase. Vitamin E and BHT singly had little ameliorative effect on the liver; however, a combination of these antioxidants reduced the enzymes levels significantly. Treatment with the antioxidants (Vitimin E and BHT) both singly and combined was also able to ameliorate the effects of the oxidative stress induced by the metals as was further confirmed by the histopathological reports.
Ba(Hf x Ti1–x )O3 ferroelectric ceramics were prepared by a conventional solid-state reaction process, and the correlation of structure, dielectric, ferroelectric, and electrocaloric properties ...were studied. The consequences indicated that the T C of Ba(Hf x Ti1–x )O3 ceramics decreased, while T T–O and T O–R increased with the increase of hafnium content. Large electrocaloric effect values of 1.64 K (117 °C) and 1.21 K (76 °C) were observed for Ba(Hf x Ti1–x )O3 with x = 0.05 compositions. And, corresponding electrocaloric coefficients respectively were 0.33 and 0.24 K·mm·kV–1. In addition, compared with the second-order phase transition region, larger electrocaloric coefficients (ΔT f /ΔE ≥ 0.19 K·mm·kV–1) were obtained in the first-order phase transition region for all compositions. Meanwhile, the maximum values of electrocaloric coefficients ΔT f /ΔE = 0.38 K·mm·kV–1 was achieved in a smaller electric field for Ba (Hf x Ti1–x )O3 with x = 0.03 compositions.
•Excessive addition or improper use of SPAs can produce possible harms.•BHT can induce apoptosis and promote tumorigenesis.•BHA metabolites are involved in carcinogenicity process.•TBHQ ...carcinogenicity is related to induction of TQ and CYP1A1.
Synthetic phenolic antioxidants can interact with peroxides produced by food. This paper reviews correlation between BHA, BHT and TBHQ metabolism and harms they cause and provides a theoretical basis for rational use of BHA, BHT and TBHQ in food, and also put some attention on the transformation and metabolic products of PG. We introduce BHA, BHT, TBHQ, PG and their possible metabolic pathways, and discuss possible harms and their specific mechanisms responsible. Excessive addition or incorrect use of synthetic phenolic antioxidants results in carcinogenicity, cytotoxicity, oxidative stress induction and endocrine disrupting effects, which warrant attention. BHA carcinogenicity is related to production of metabolites TBHQ and TQ, and cytotoxic effect of BHA is the main cause of apoptosis induction. BHT carcinogenicity depends on DNA damage degree, and tumour promotion is mainly related to production of quinone methylation metabolites. TBHQ carcinogenicity is related to induction of metabolite TQ and enzyme CYP1A1.
The Beijing–Tianjin–Hebei (BTH) integration project in China is ambitious which offers great potential with its promotion of sustainable and inclusive development. This study investigates the impact ...of regional financial development on economic growth in the BTH region, with panel data collected from 2007 to 2016. Two indicators namely, CREDIT (denoted as regional financial development depth) and BRANCH (denoted as regional financial intermediaries accessibility) are used to construct an integrated regional financial development indicator through the spatial econometrics approach. The spatio-temporal distribution characteristics of regional financial development and economic growth are analyzed. Afterward, the global Moran’s I and local Getis–Ord Gi* statistics are applied to detect the presence of spatial autocorrelation. Finally, a spatial Durbin model (SDM) is utilized to examine spatial distribution and spatial association. The research findings of this study suggest that the CREDIT has a positive effect on regional economic growth, while the BRANCH has no impact on regional economic growth. Moreover, it is found that the spatial autocorrelation of CREDIT and BRANCH are statistically significant. The CREDIT of the neighboring areas has a negative spatial spillover effect on economic growth of one area, while the BRANCH in the neighboring areas has a positive effect on the one area. The results and research findings reported in this article highlight the role of regional financial development in improving the economic growth not only for Chinese policy makers but also for other countries’ researchers and practitioners in this field.
•The impact of regional financial development on economic growth in the BTH region are estimated.•The spatial autocorrelation of regional financial development and economic growth is measured.•The magnitude of spatial spillover effects on economic growth are studied.•Some policy suggestions in better driving economic growth are presented.
A BHT-regulated chemoselective monofluorination of enaminones with Selectfluor under mild reaction conditions was unveiled for the first time. As a result, an array of monofluorinated chromones were ...efficiently assembled in a simple operational manner. Moreover, the scalability of this protocol and the versatility for the downstream transformations of the obtained fluorinated chromones to installing diverse nitrogen-containing heterocycles greatly broaden the practical applications of this developed protocol.
Display omitted
•A BHT-regulated chemoselective monofluorination of enaminones with Selectfluor under mild reaction conditions was unveiled for the first time.•Moreover, the scalability of this protocol and the versatility for the downstream transformations of the obtained fluorinated chromones to installing diverse nitrogen-containing heterocycles greatly broaden the practical applications of this developed protocol.
Synthetic phenolic antioxidants (SPAs) such as 2,6-di-tert-butyl-4-hydroxytoluene (butylated hydroxytoluene, BHT), are used in a wide variety of consumer products, including certain foodstuffs (e.g. ...fats and oils) and cosmetics. Although BHT is considered generally safe as a food preservative when used at approved concentrations, there is debate whether BHT exposure is linked to cancer, asthma, and behavioral issues in children. Little is known with regard to human exposure to SPAs and the methods to measure these chemicals in urine. In this study, six SPAs and the metabolites were analyzed in 145 urine samples collected from four Asian countries (China, India, Japan, and Saudi Arabia) and the United States. BHT was found in 88% of the urine samples at median and maximum concentrations of 1.26 and 15 ng/mL, respectively. BHT metabolites and butylated hydroxyanisole (BHA) were found in 39% to 89% of the urine samples at a concentration range of <LOQ-46 ng/mL. 3,5-Di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH), the major metabolite of BHT, is suggested as a potential urinary biomarker of exposure to BHT. The estimated median daily intakes (EDIs) of BHT, calculated from urinary concentrations, in children and adults were 0.38–56.6 and 0.21–31.3 μg/kg bw/day, respectively. BHT levels were high in urine samples from Japan, India, and the United States.
Display omitted
•Synthetic phenolic antioxidants were measured in human urine for the first time.•3,5-di-tert-butyl-4-hydroxybenzoic acid is a biomarker of BHT in urine.•The highest BHT exposure was found in samples from Japan, India and the U.S.•Besides diet, several other sources contribute to BHT exposure.
There are concerns about using synthetic phenolic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) as food additives because of the reported negative effects on ...human health. Thus, a replacement of these synthetics by antioxidant extractions from various foods has been proposed. More than 8000 different phenolic compounds have been characterized; fruits and vegetables are the prime sources of natural antioxidants. In order to extract, measure, and identify bioactive compounds from a wide variety of fruits and vegetables, researchers use multiple techniques and methods. This review includes a brief description of a wide range of different assays. The antioxidant, antimicrobial, and anticancer properties of phenolic natural products from fruits and vegetables are also discussed.
PDF
