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1.
Environ Sci Technol ; 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33961405

RESUMO

As one of the extensively used feed additives in livestock and poultry breeding, p-arsanilic acid (p-ASA) has become an organoarsenic pollutant with great concern. For the efficient removal of p-ASA from water, the combination of chemical oxidation and adsorption is recognized as a promising process. Herein, hollow/porous Mn-Fe-mixed oxide (MnFeO) nanocubes were synthesized and used in coupling with peroxymonosulfate (PMS) to oxidize p-ASA and remove the total arsenic (As). Under acidic conditions, both p-ASA and total As could be completely removed in the PMS/MnFeO process and the overall performance was substantially better than that of the Mn/Fe monometallic system. More importantly, an interface-promoted direct oxidation mechanism was found in the p-ASA-involved PMS/MnFeO system. Rather than activate PMS to generate reactive oxygen species (i.e., SO4·-, ·OH, and 1O2), the MnFeO nanocubes first adsorbed p-ASA to form a ligand-oxide interface, which improved the oxidation of the adsorbed p-ASA by PMS and ultimately enhanced the removal of the total As. Such a direct oxidation process achieved selective oxidation of p-ASA and avoidance of severe interference from the commonly present constituents in real water samples. After facile elution with dilute alkali solution, the used MnFeO nanocubes exhibited superior recyclability in the repeated p-ASA removal experiments. Therefore, this work provides a promising approach for efficient abatement of phenylarsenical-caused water pollution based on the PMS/MnFeO oxidation process.

2.
Opt Lett ; 46(8): 1975-1978, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33857120

RESUMO

In this Letter, considering the chiral-graphene-chiral structure, we investigate the more universal dispersion relation covering the achiral cases, the effect of the chirality of a medium, and the chemical potential of graphene on the behavior of graphene surface plasmon polaritons (GSPPs) and transverse spin density, which is key to understanding the lateral optical force. This research is dedicated to looking for a regulating mechanism based on chirality and graphene to apply in devices of information processing and biosensor for identifying molecular chirality. We found the averaging effect of chirality in both sides of graphene in tuning the behavior of GSPPs. We believe this work can make contributions to enrich SPP theory and benefit the development of novel detection techniques for chiral molecules based on graphene.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33860894

RESUMO

Pharmaceuticals, such as over-the-counter (OTC) medicines, may be an important source of human exposure to several endocrine disruptors, though unnoticed to date. In the present study, we investigated the presence of six parabens and nine bisphenol A (BPA) and its analogues in OTC medicines manufactured in China. Parabens and bisphenols were present in more than 90% of the samples. The total measured concentrations of parabens and bisphenols were in the range of non-detectable (ND) to 213 ng/g and ND to 415 ng/g, respectively. Regarding parabens, methyl paraben (MeP) was the predominant analog, accounting for 43 ± 36% of the total amount, followed by ethyl paraben (EtP) (39 ± 35%), and others (< 10%). Bisphenol F and BPA were the predominant bisphenols, accounting for 24 ± 28% and 22 ± 26% of the total amount, respectively. The median values of estimated daily intakes (EDIs) of parabens and bisphenols were the highest for infants (2.96 and 3.14 ng/kg_bw/day, respectively) and the lowest for adults (0.69 and 0.25 ng/kg_bw/day, respectively); moreover, the EDIs of parabens and bisphenols were higher in Chinese patent medicines than in western pediatric medicines. The hazard quotient (HQ) for sum of MeP and EtP (∑(MeP + EtP)) and BPA in three age groups were within the safe zone (HQ < 0.0004). Monte Carlo simulation was applied to predict the human exposure risk of parabens and bisphenols. The predicted ranges of EDIs of parabens and bisphenols were much wider, and the extreme predicted values were observed in all four age groups, which were higher than the acceptable daily intake. The extreme predicted values of ∑(MeP + EtP) and BPA were indicative of carcinogenic risk in toddlers. These results implied potential risks for the Chinese people existed. Considering the huge export of Chinese traditional medicines and western medicines worldwide, and easy access to OTC medicines for the general population, the presence of parabens, bisphenols, and other environmental contaminants in medicines still need to be monitored.

4.
Sci Total Environ ; 782: 146806, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33836381

RESUMO

We spend more than half of our daily time in indoor environments, and the contributions of phthalates present in it to total exposure are important. Here, we determined phthalate concentrations in paired indoor settled dust/air and their metabolites in human urine from 100 general families in south China to explore such kind of effect. The total concentrations of phthalates/metabolites were 48.7-2850 µg/g, 279-5080 ng/m3 and 10.7-2840 ng/mL in the indoor dust, air and urine samples, respectively. Among all targets, di-n-butyl phthalate, di-isobutyl phthalate and di-(2-ethylhexyl) phthalate and their metabolites were the predominant compounds. The daily intakes (DIs) of phthalates via dust or air decreased with age, except for infant, and the values of dust ingestion, air inhalation and air dermal uptake were 2720 ± 2460, 1300 ± 973 and 3590 ± 2890 ng/kg/day for toddlers and 236 ± 194, 360 ± 179 and 1120 ± 586 ng/kg/day for adults, respectively. The ratios of DIs from air to dust were greater than 1.0 for people in all age groups, and the ratio was the highest for adults. Furthermore, the contributions of phthalates from indoor dust and air to total DIs from all sources (estimated from urinary phthalate metabolites) were 0.60%-5.23% and 2.65%-12.2% for different ages, respectively. Our results indicated that indoor air was a quite important source for human exposure to phthalates in indoor environment in south China.

5.
J Drug Target ; : 1-8, 2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33896301

RESUMO

Intracellular Ca2+ ions as second messenger played key role in cell behaviour, which was often overlooked in traditional antitumor treatment. Disrupting Ca2+ ion homeostasis by Ca2+ overload might switch ions signal from 'regulating' to 'destroying'. Inspired by this, a biomimetic Ca2+ nanogenerator was constructed. Briefly, the curcumin (CUR) was loaded into mesoporous calcium carbonate nanoparticles (MCC NPs), and then coated with platelet (PLT) membrane. Upon reaching tumour cells by PLT membrane-mediated tumour targeting effect, PLT@MCC/CUR would instantaneously decompose in acidic lysosomes, concurrently accompanying with Ca2+ generation and CUR release. The CUR could further facilitate Ca2+ release from endoplasmic reticulum (ER) and inhibit Ca2+ efflux, aggravating Ca2+ overload to disrupt mitochondrial Ca2+ homeostasis for mitochondria apoptosis signalling pathway activation. Interestingly, such effect was ineffective in normal cells, realising the tumour-specific therapeutic therapy. Based on ions interference strategy, PLT@MCC/CUR herein offered synergistic combination of Ca2+ overload therapy and chemotherapy, which would pave the way towards more effective nanotherapeutics.

6.
Molecules ; 26(6)2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799697

RESUMO

Lithium metal batteries have achieved large-scale application, but still have limitations such as poor safety performance and high cost, and limited lithium resources limit the production of lithium batteries. The construction of these devices is also hampered by limited lithium supplies. Therefore, it is particularly important to find alternative metals for lithium replacement. Sodium has the properties of rich in content, low cost and ability to provide high voltage, which makes it an ideal substitute for lithium. Sulfur-based materials have attributes of high energy density, high theoretical specific capacity and are easily oxidized. They may be used as cathodes matched with sodium anodes to form a sodium-sulfur battery. Traditional sodium-sulfur batteries are used at a temperature of about 300 °C. In order to solve problems associated with flammability, explosiveness and energy loss caused by high-temperature use conditions, most research is now focused on the development of room temperature sodium-sulfur batteries. Regardless of safety performance or energy storage performance, room temperature sodium-sulfur batteries have great potential as next-generation secondary batteries. This article summarizes the working principle and existing problems for room temperature sodium-sulfur battery, and summarizes the methods necessary to solve key scientific problems to improve the comprehensive energy storage performance of sodium-sulfur battery from four aspects: cathode, anode, electrolyte and separator.

7.
JAMA Netw Open ; 4(4): e215302, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33835173

RESUMO

Importance: The World Health Organization End TB (Tuberculosis) Strategy aims to decrease the global incidence and mortality of TB by 90% and 95%, respectively, as of 2035. Objective: To characterize the recent epidemiological trend of pulmonary TB (PTB) in mainland China based on the national surveillance data. Design, Setting, and Participants: This cross-sectional study collected demographic and clinical data of all patients reported in the national Tuberculosis Information Management System of China from January 1, 2005, to November 21, 2016. Data were analyzed from December 1, 2019, to July 31, 2020. Exposures: Pulmonary TB was defined as bacteriologically confirmed or clinically diagnosed TB in the lung parenchyma or the tracheobronchial tree. Main Outcomes and Measures: Temporal and spatial variation of annual incidence and demographic features of PTB in mainland China. Results: In total, 10 582 903 patients with PTB were reported in mainland China from 2005 to 2016. The median age of patients with PTB was 46 (interquartile range [IQR], 30-61) years, and 28.53% were 60 years or older. Most patients with PTB were male (69.8%) and farmers or herders (70.0%). The mean (SD) incidence of PTB was 66.61 (8.09) per 100 000 population. The annual incidence decreased from 72.95 per 100 000 population in 2005 to 52.18 per 100 000 population in 2016, and the reduction was greater in the eastern and central regions (31.6%; from 69.43 to 47.48 per 100 000 population) than in the western region (21.0%; from 82.06 to 64.82 per 100 000 population). Xinjiang Uygur Autonomous Region (135.03 per 100 000 population), Guizhou Province (115.98 per 100 000 population), and the Tibet Autonomous Region (101.98 per 100 000 population) had the highest mean annual incidences. The median time from onset of illness to diagnosis decreased from 36 (IQR, 16-92) days from 2005 to 2007 to 31 (IQR, 15-63) days in 2008 and later (P < .001) and was longer in the western region than in the eastern and central regions (41 [IQR, 20-91] vs 30 [IQR, 13-61] days; P < .001). Conclusions and Relevance: Although this study found that the incidence of PTB in mainland China showed a downward trend from 2005 to 2016, to achieve the World Health Organization 2035 goal, innovative and more efficient prevention and control strategies are needed, particularly among the most susceptible population, that is, farmers and herders in western China.

8.
J Anim Sci ; 99(4)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33693756

RESUMO

The aim of this study was to investigate the involvement of prolactin (PRL) on development of secondary skin follicles in cashmere goats. Goats were randomly assigned to either a bromocriptine treatment or control group. Samples of cashmere fiber, blood, and skin were collected from all goats after 1 mo. The results indicated that the length, growth rate, and diameter of fibers were not influenced (P > 0.05) by the inhibition of PRL resulting from the treatment with bromocriptine. There was a tendency for increases in total follicle number, primary and secondary follicle numbers, and in the ratio of secondary to primary follicles following treatment with bromocriptine, but these differences were not significant (P > 0.05). The percentage of active secondary follicles in anagen was increased (P < 0.05) in the bromocriptine-treated goats, but there was no effect of treatment on the percentage of active primary follicles. Bromocriptine decreased (P < 0.05) circulating concentrations of PRL and Insulin-like growth factor 1 (IGF1) and increased (P < 0.05) those of melatonin (MT), but there was no effect of this treatment on the serum concentrations of cortisol, growth hormone, tetraiodothyronine, and triiodothyronine. In bromocriptine-treated goats, mRNA expressions of PRL and MT membrane receptor 1a (MTNR1a) were decreased (P < 0.05) and mRNA expression of MT nuclear receptor (RORα) was increased (P < 0.05), but there was no effect of the treatment on expression of long PRL receptor, short PRL receptor, MT membrane receptor 1b and IGF1. It is concluded that inhibition of PRL promotes secondary hair follicle development in the anagen phase, possibly by downregulating MTNR1a and up-regulating RORα gene expression in the skin.


Assuntos
Cabras , Prolactina , Animais , Feminino , Folículo Piloso , Receptores da Prolactina/genética , Pele
9.
J Trace Elem Med Biol ; 66: 126720, 2021 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-33676114

RESUMO

BACKGROUND: As4S4 is widely used in Chinese traditional medicine compound. However, based on some recent studies, we found that the cardiotoxicity risk of using As4S4 in ischemic heart disease patients may be increased. To study this potential risk, we compared the effects of As4S4 on rat ventricular H9c2 cell line with or without hypoxic pretreatment, and to elucidate mechanisms of c-Cbl mediated ubiquitination/degradation of integrin ß1. METHODS: The present study was conducted on rat ventricular H9c2 cell line in the absence or presence of hypoxic pretreatment for 6 h followed by As4S4 treatment for 24 h. Following As4S4 treatment, cell viability assay, flow cytometric quantification of apoptotic cells, caspase-3 activity assay and DAPI staining were conducted. Western blotting was carried out to detect expressions of ubiquitination related proteins. In addition, the ubiquitination/degradation of integrin ß1 and the role of c-Cbl in it was evaluated by immunoprecipitation and immunoblot assay. RESULTS: The viability of cells with hypoxic pretreatment followed by As4S4 treatment was decreased significantly, apoptosis rate and the activity of caspase-3 were increased than As4S4 treatment alone. The ubiquitin-proteasome degradation pathway induced by As4S4 was further enhanced by hypoxic pretreatment. The results of IP and immunoblot assay showed hypoxic enhanced down-regulation effect of As4S4 on integrin ß1 probably through c-Cbl activation. CONCLUSIONS: This study demonstrated that the hypoxia enhanced cytotoxicity of As4S4 on H9c2 cells may through increasing the ubiquitin-proteasome degradation of integrin ß1 mediated by the E3 ligase c-Cbl. The results provide an important clue that, in patients with ischemic heart disease, use of As4S4 may be associated with increased cardiotoxicity. We believe that the results worth to be further illuminated by in vivo and clinical research.

10.
Surg Innov ; : 15533506211006057, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33787389

RESUMO

Background. The Mirizzi syndrome (MS) is a rare complication of cholecystolithiasis that is often accompanied by severe inflammation and fibrosis around Calot's triangle. It is difficult to treat Type 2 MS surgically, and the treatment for this condition has not yet been standardized. The data on operative management are limited. The study aimed to review our institutional clinical experience regarding surgery and provide recommendations for treating Type 2 MS. Methods: We conducted a retrospective study on 6 patients with MS who were surgically treated at our institution between January 2010 and December 2019. The classification of MS by McSherry CK, Ferstenberg H, Virshup M. The Mirizzi syndrome: Suggested classification and surgical therapy. Surg Gastroenterol. 1982;1:219-225 was used. Mucosal approach was used to treat Type 2 MS. The parameters for comparison included patient demographics, operative procedures, operation time, blood loss, length of hospital stay, complications, and follow-up. Results: There were 23 patients with MS among 10 386 cholecystectomies in our area. Six patients with Type 2 MS had successful surgery, and the mucosal approach was used. The average operative time was 253.3 ± 32.5 minutes. The average blood loss was 70.0 ± 14.1 mL. The mean postoperative hospital stay was 9.5 ± 3.9 days. There was no postoperative mortality. The most frequent postoperative complications were bile leakage (16.7%), and postoperative intra-abdominal collection (16.7%). The mean postoperative follow-up was 10 months, and all patients are asymptomatic. The mucosal approach may decrease the risk of bile duct injury, biliary tract infection, and blood loss more than other surgical approaches. Conclusion: This study demonstrates that the mucosal approach is an effective surgical procedure for Type 2 MS.

11.
Stem Cell Res Ther ; 12(1): 171, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33691785

RESUMO

INTRODUCTION: Renal interstitial fibrosis, an important pathological feature of kidney aging and chronic renal failure, is regulated by mesenchymal stem cells (MSCs). We have previously demonstrated low expression of miR-133b in MSC-derived extracellular vesicles (MSC-EVs) in aged rats. However, miR-133b can mediate the inhibition of epithelial-mesenchymal transition (EMT) of renal tubules induced by transforming growth factor-ß1 (TGF-ß1). We investigated the effect of miR-133b for the treatment of geriatric renal interstitial fibrosis and evaluated its target genes. METHODS: We performed real-time polymerase chain reaction to detect miR-133b expression induced during EMT of HK2 cells by TGF-ß1 at different concentrations (0, 6, 8, and 10 ng/mL) and at different time points (0, 24, 48, and 72 h). The target genes of miR-133b were validated using the dual-luciferase reporter assay. In vitro experiments were performed to evaluate mRNA and protein expression of miR-133b targets, E-cadherin, α-smooth muscle actin (SMA), fibronectin, and collagen 3A1 (Col3A1), in HK2 cells transfected with miR-133b under TGF-ß1 stimulation. A 24-month-old unilateral ureteral obstruction (UUO) mouse model was established and injected with transfection reagent and miR-133b into the caudal vein. The target gene of miR-133b and other parameters mentioned above such as mRNA and protein expression levels and renal interstitial fibrosis were detected at 7 and 14 days. RESULTS: miR-133b expression gradually decreased with an increase in TGF-ß1 concentration and treatment time, and the miR-133b mimic downregulated connective tissue growth factor (CTGF) expression. The dual-luciferase reporter assay confirmed CTGF as a direct target of miR-133b. Transfection of the miR-133b mimic inhibited TGF-ß1-induced EMT of HK2 cells; this effect was reversed by CTGF overexpression. miRNA-133b expression significantly increased (approximately 70-100 times) in mouse kidney tissues after injection of the miRNA-133b overexpression complex, which significantly alleviated renal interstitial fibrosis in mice with UUO. CONCLUSION: miR-133b exerted targeted inhibitory effects on CTGF expression, which consequently reduced TGF-ß1-induced EMT of HK2 cells and renal interstitial fibrosis in aged mice with UUO.

12.
J Med Chem ; 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33586434

RESUMO

It remains a big challenge to develop HDAC inhibitors effective for solid tumors. Previous studies have suggested that the feedback activation of JAK-STAT3 pathway represents a key mechanism leading to resistance to HDAC inhibitors in breast cancer, suggesting the therapeutic promise of JAK/HDAC dual inhibitors. In this work, we discovered a series of pyrrolo[2,3-d]pyrimidine-based derivatives as potent JAK and HDAC dual inhibitors. Especially, compounds 15d and 15h potently inhibited JAK1/2/3 and HDAC1/6 and displayed antiproliferative and proapoptotic activities in triple-negative breast cancer cell lines. Besides, compounds 15d and 15h also diminished the activation of LIFR-JAK-STAT signaling triggered by tumor-associated fibroblasts, which suggests that these compounds could potentially overcome the drug resistance caused by the tumor microenvironment. More importantly, compound 15d effectively inhibited the tumor growth in MDA-MB-231 xenograft tumor model. Overall, this work provides valuable leads and novel antitumor mechanisms for the treatment of the SAHA-resistant triple-negative breast cancers.

13.
ACS Nano ; 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33569948

RESUMO

Superhydrophobic membranes are desirable for separation of water-in-oil emulsions, membrane distillation, and membrane condensation. However, the lack of large-scale manufacture methods of superhydrophobic membranes hampers their widespread applications. Here, a facile method of coaxial electrospinning is provided to manufacture superhydrophobic membranes for the ultrafast separation of water-in-oil emulsions. Under the high-voltage electric field, the polydimethylsiloxane (PDMS)-coated polyvinylidene fluoride (PVDF) nanofibers and PDMS microspheres with PVDF nanobulges were integrated together during the electrospinning process. Moreover, asymmetric composite membranes with selective layers are designed to reduce the resistance of the mass transfer. Consequently, the as-prepared asymmetric composite membrane exhibits an ultrafast permeance and excellent separation efficiency of about 99.6%, outperforming most of the state-of-the-art membranes reported previously. Most importantly, the membrane could be as large as 770 cm2, could be manufactured continuously, and could be easily enlarged further via tailoring the roller receptor, showing strong promise in the separation of water-in-oil emulsions.

14.
Inorg Chem ; 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33417440

RESUMO

The generation of elastic crystalline fibers from a nonfibrous crystal of metal complex is demonstrated. Applying mechanical stimuli to a platelike crystal of NiII(salophen) [1; H2salophen = N,N'-bis(salicylidene)-o-phenylenediamine] resulted in this complex being transformed into crystal fibers, which could be bent into a loop and demonstrated its high elasticity. Single-crystal X-ray diffraction analyses revealed that the transformation reflects the presence of molecular strands that are composed of a one-dimensional assembly of the slip-stacked arrangement by nearly planar Ni(salophen) molecules. The fiber flexibility was demonstrated to be lost upon the introduction of chloroform solvent molecules into the crystal lattice by recrystallization.

15.
Environ Int ; 149: 106405, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33516990

RESUMO

A comparative study of internal and external exposure is a good method to comprehensively understand human exposure to environmental contaminants that may trigger oxidative stress in human body. Information is limited regarding the influences of reactive oxygen species (ROS) on human health from the environment. In addition, data on the contribution of polycyclic aromatic hydrocarbons (PAHs) from indoor environments, especially air, to total human exposure are still insufficient. The present study measured PAHs in paired indoor dust (n = 101), gas (polyurethane foams, n = 100), and particle samples (quartz fiber filters, n = 100) and their hydroxy metabolites (OH-PAHs) in 205 urine samples from 101 families in Guangzhou, South China. The oxidative potential (OP) in dust samples was quantified with a dithiothreitol (DTT) assay to reflect the oxidizability of ROSs, and explore the relationship between environmental ROSs and oxidative stress in humans (using urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker). The estimated daily intakes (EDIs) of Σ16PAH via air inhalation were much higher than those from gas dermal contact, dust dermal contact, and dust ingestion (mean: 19.5 > 4.27 > 3.75 > 1.60 ng/kg_bw/day). Generally, approximately 16% of naphthalene, 28% of fluorene, 9% of phenanthrene, and 3% of pyrene were derived from indoor environments for all residents when compared with the total PAH exposure amount from all sources. Significantly positive relationships were found between OH-PAHs and 8-OHdG (coefficients ß: 0.129-0.366, p < 0.05) checked by linear mixed effect models, and males seemed to be more susceptible than females to the DNA oxidative damage related to PAH exposure. The mean OP value in dust was 7.14 ± 6.68 pmol/(min·µg). Individual PAHs in dust gradually intensified the oxidizability of dust particles as their molecular weight increased. A potential but not significant dose-relationship was found between dusty OP and urinary 8-OHdG. Further work should determine the impact of chemical profiles on OP in different environmental media and continuously explore the potential to use OP as a useful indicator to reflect the total oxidizability of several groups of environmental pollutants.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , China , Poeira/análise , Monitoramento Ambiental , Feminino , Corpo Humano , Humanos , Masculino , Estresse Oxidativo , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade
16.
Water Res ; 191: 116799, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33453457

RESUMO

Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) for wastewater treatment have recently attracted widespread interests. However, the degradation of organic pollutants via traditional radical-dominated pathway is severely limited by the side reactions between radicals and the co-existing inorganic anions, especially under high salinity conditions. Herein, an efficient Fe/O co-doped g-C3N4nanosheet catalyst was synthesized to dominantly activate PMS through a dual non-radical pathway with the singlet oxygen and high-valent iron-oxo species (Fe(V)=O). The rapid degradation of model pollutant bisphenol A (BPA) was achieved by dosing PMS (1 mM), catalyst (0.1 g/L) in a simulated high-salt wastewater (≥200 mM) of the developed Fe/O-doped g-C3N4+PMS system with a reaction rate constant of 1204-fold higher than that in g-C3N4+PMS system. The O and Fe co-dopants could reconfigurate the electronic structure of pristine g-C3N4 to produce more non-radical active species. The formed Fe(V)=O played a main role in the BPA degradation by promoting electron transfer from BPA molecule to the "metastable PMS/catalyst complex", which was verified by electrochemical tests and density functional theory calculations. The auxiliary transient productions of ·OH+SO4·- species were also favorable for the pollutant degradation. Excellent reusability in a wide pH range confirmed the practical application prospects of the Fe/O-doped g-C3N4+PMS system. The successive addition of PMS with a low dosage into the system rich in pollutants was confirmed to favor the PMS utilization. Our work unveils the potential applications of a non-radical dominated process for the decontamination of organic pollutants in saline water.


Assuntos
Poluentes Ambientais , Descontaminação , Peróxidos , Salinidade
17.
Artigo em Inglês | MEDLINE | ID: mdl-33440937

RESUMO

Electrochemical sensors, with high accuracy, good selectivity, and linear response, have been widely used for environmental protection, health monitoring, and disease treatment. However, to date, these sensors still have limit sensitivity or otherwise require the use of high-cost materials such as noble metals and enzymes. Here, we report a novel electrochemical sensor using a topological insulator, Bi2Te3. Through liquid-phase exfoliation, we prepared nano- and microflakes of Bi2Te3 and measured their performance in hydrogen peroxide sensing via electrocatalytic reduction processes. Our devices exhibit a sensitivity of ∼4900 µA mM-1 cm-2 and a detection limit of ∼10-8 molar, both of which are superior to typical noble metal-based electrochemical sensors. Through electrochemical analysis and microkinetic simulations, we extracted the kinetic parameters and gained insights into the reaction mechanism. We attribute the ultrahigh sensitivity to the facile electron transfer at the Bi2Te3-aqueous solution interface.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33427454

RESUMO

Membrane fouling is the obstacle that limits the practical application of membranes in efficient oil/water separation. The main reason for membrane fouling is the deposition of the dispersed phase (e.g., oil) on the membrane surface based on the sieving effect. The key challenge for solving the fouling problem is to achieve fouling removal via rationally considering hydrodynamics and interfacial science. Herein, a poly(vinylidene fluoride) membrane with a dual-scale hyperporous structure and rational wettability is designed to achieve a continuous "nonfouling" separation for oil/water emulsions via membrane demulsification. The membrane is fabricated via dual-phase separation (vapor and nonsolvent) and modified by in situ polymerization of poly(hydroxyethyl methylacrylate) (contact angle 59 ± 1°). The membrane shows stable permeability (1078 ± 50 Lm-2h-1bar-1) and high separation efficiency (>99.0%) in 2 h of continuous cross-flow without physicochemical washing compared to superwetting membranes. The permeation is composed of two distinct immiscible liquid phases via coalescence demulsification. The surface shearing and pore throat collision coalescence demulsification mechanism is proposed, and rational interface wettability facilitates the foulant/membrane interaction for "nonfouling" separation. Beyond superwetting surfaces, a new strategy for achieving "nonfouling" emulsion separation by designing membranes with a dual-scale hyperporous structure and rational wettability is provided.

19.
J Environ Manage ; 277: 111426, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33032002

RESUMO

A novel process for recycling of spent LiCoO2 cathode materials has been developed. The novel process comprises an ultrasonic enhanced leaching and one-step regeneration of LiCoO2 materials with spray drying method. The ultrasonic is novelly applied for effectively improving leaching process of spent LiCoO2 materials in the system of DL-malic acid and H2O2. The leaching efficiencies of 98.13% for Li and 98.86% for Co were presented under the optimal condition of 1.5 mol/L DL-malic acid with 3 vol% H2O2, the solid/liquid ratio of 4 g/L, ultrasonic power of 95 W, temperature of 80 °C and leaching time of 25 min. Based on kinetic analysis, the ultrasonic enhanced leaching process is mainly controlled by the diffusion control model. Meanwhile, the product of Co(C4O5O5)2 formed on particles surface of spent LiCoO2 materials during ultrasonic enhanced leaching process, which is provided from reaction mechanism analysis of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Finally, the regenerated LiCoO2 materials are regenerated in one step by spray drying from leaching solution, which present good electrochemical performance.


Assuntos
Lítio , Ultrassom , Fontes de Energia Elétrica , Eletrodos , Peróxido de Hidrogênio , Cinética , Reciclagem , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Dalton Trans ; 50(2): 494-498, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33367344

RESUMO

The synthesis of [M(dimphen)(NCS)2] (1; M = FeII), (2; M = CoII), (3; M = MnII) and [Fe(dimphen)(NCSe)2] (4), where dimphen = [1,2-bis(9-methyl-1,10-phenanthrolin-2-yl)ethane], are reported. The crystal packing structures of 1-3, show intermolecular π-π stacking and NCSSCN interactions. The complex 1 shows ferromagnetic interaction, and the complex 2 displays single-molecular magnet behaviour.

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