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1.
Int J Biol Macromol ; 270(Pt 1): 132142, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38719005

RESUMO

The severe negative effects of impurities adhering to the external surface of wearable devices can significantly influence the signal transmission, performance, and lifespan of hydrogel sensors. Herein, we developed an ion-conducting hydrogel sensor with a strong adhesive side and a non-adhesive side, similar to a "semi-releasing material." This hydrogel, formulated using deep eutectic solvents obtained from choline chloride and acrylic acid, contained lignin. This versatile material, exhibiting properties similar to semi-releasing materials, was treated with an AlCl3 solution on one side. Additionally, the hydrogel was successfully used as a highly adhesive strain sensor for real-time monitoring of various human activity signals. Moreover, the hydrogel demonstrated excellent environmental tolerance and conductivity. Lignin extracted from wood flour endowed the hydrogel sensor with excellent adhesion energy (up to 427.1 J/m2) and UV resistance. Treatment of hydrogels with AlCl3 completely eliminated their adhesiveness, thereby enhancing fracture elongation and tensile strength. This improvement can be attributed to the absence of carboxyl groups and the formation of a metal-phenolic network. The implementation of this convenient and efficient strategy provides a more feasible approach to address challenges related to impurity adhesion and signal transmission in flexible wearable devices.


Assuntos
Hidrogéis , Lignina , Dispositivos Eletrônicos Vestíveis , Lignina/química , Hidrogéis/química , Humanos , Condutividade Elétrica , Resistência à Tração , Cloreto de Alumínio/química , Íons/química
2.
Sci Total Environ ; 930: 172034, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38657806

RESUMO

Due to their assembly properties and variable molecular weights, the potential biological toxicity effects of macromolecular organic ligand heavy metal complexes are more difficult to predict and their mechanisms are more complex. This study unraveled the toxicity response and metabolic compensation mechanism of tannic acid-Cr(III) (TA-Cr(III)) complex on alga Raphidocelis subcapitata using multi-omics approaches. Results showed TA-Cr(III) complex caused oxidative damage and photosystem disruption, destroying the cell morphology and inhibiting algal growth by >80 % at high exposure levels. TA-Cr(III) complex stress down-regulated proteins linked to proliferation, photosynthesis and antioxidation while upregulating carbon fixation, TCA cycle and amino acid metabolism. The increase of fumarate, citrate, isocitrate and semialdehyde succinate was validated by metabolomics analysis, which improved the TCA cycle, amino acid metabolism and carbon fixation. Activation of the above cellular processes somewhat compensated for the inhibition of algal photosynthesis by TA-Cr(III) complex exposure. In conclusion, physiological toxicity coupled with downstream metabolic compensation in response to Cr(III) complex of macromolecular was characterized in Raphidocelis subcapitata, unveiling the adaptive mechanism of algae under the stress of heavy metal complexes with macromolecular organic ligands.


Assuntos
Taninos , Cromo/toxicidade , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Polifenóis
3.
J Neurosci Res ; 102(3): e25324, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38515341

RESUMO

Patients with symptomatic intracranial arterial stenosis (sICAS) suffer embarrassed hemodynamic status and acute ischemic stroke (AIS) recurrence. We aimed to assess the efficacy of remote ischemic conditioning (RIC) on improving this status by evaluating cerebral blood flow (CBF) and cerebral glucose metabolism (CGM) via PET/CT. Adult patients with unilateral sICAS in middle cerebral artery and/or intracranial segment of internal carotid artery-related AIS or transient ischemic attack within 6 months prior to randomization were enrolled. Individuals who received intravenous thrombolysis or endovascular treatment, or sICAS caused by cardiac embolism, small vessel occlusion, or other determined causes were excluded. Twenty-three eligible patients were randomly assigned to standard medical treatment (SMT) (n = 10) or RIC group (n = 13). The RIC protocol consisted of 5 cycles, each for 5-min bilateral upper limb ischemia and 5-min reperfusion period, twice a day, with a total duration of 3 months. Ten healthy volunteers were enrolled as healthy control group. We tested CBF and CGM at the rest stage and the methazolamide-induced stress stage. All patients received PET/CT at baseline and three-month followup. Both CBF and CGM in ipsilateral hemisphere of sICAS patients were significantly decreased at the rest stage and the stress stage (p < .05), which were improved by three-month RIC (p < .05). The lesions decreased notably in RIC group compared to SMT group (p < .05). RIC ameliorated the hemodynamic status and glucose metabolism in regions at high risk of infarction, which might improve the resistance capacity towards ischemic load in sICAS patients.


Assuntos
Arteriosclerose Intracraniana , AVC Isquêmico , Adulto , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/terapia , Isquemia , Hemodinâmica , Glucose
4.
Int J Stroke ; 19(6): 635-644, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38353219

RESUMO

BACKGROUND: The efficacy and safety of dabigatran etexilate for Chinese patients with cerebral venous thrombosis (CVT) has not been well established. METHODS: CHOICE-CVT was an exploratory, single-center, randomized, open-label study in the National Center for Neurological Disorders involving Chinese patients with CVT aged 18 to 80 years who were randomly assigned (1:1) to either dabigatran etexilate or warfarin. Oral anticoagulants were initiated after 10-15 days of LMWH. The primary efficacy and safety endpoints included the number of patients with recurrent CVT and/or deep venous thrombosis (DVT) and major clinical bleeding within 180 days. Secondary efficacy endpoints included venous recanalization and change in papilledema at day 180. Secondary safety outcomes comprised death, clinical nonmajor bleeding, and any bleeding. The study was registered with ClinicalTrials.gov under NCT03930940. RESULTS: Between October 2017 and February 2023, a total of 89 patients were enrolled and randomly assigned to receive either dabigatran etexilate (n = 44) or warfarin (n = 45). At day 180, the dabigatran etexilate group showed a statistically nonsignificant but likely clinically significant number of patients with recurrent CVT and/or DVT (8 (18.2%; 95% CI, 6.3-30.0) vs 3 (6.7%; 95% CI, 0.0-14.2), p = 0.099, with a power (1-ß) of 38.401%) compared with the warfarin group. The dabigatran etexilate group showed a comparable number of patients with clinical major bleeding (0 (0) vs 0 (0) p = 1.000), and clinical nonmajor bleeding (1 (2.3%; 95% CI, 0.0-6.9) vs 1 (2.2%; 95% CI, 0.0-6.7)) but demonstrated a lower risk of any bleeding (1 (2.3%; 95% CI, 0.0-6.9) vs 9 (20.0%; 95% CI, 7.8-32.2)) compared with the warfarin group. Most patients in both groups achieved venous recanalization according to the Modified Qureshi scale (27 (75%; 95% CI, 60.1-89.9) in the dabigatran etexilate group vs 34 (82.9%; 95% CI, 70.9-95.0) in the warfarin group) and exhibited improvement in papilledema as per the Frisén classification (35 (97.2%; 95% CI, 91.6-100.0) in the dabigatran etexilate group vs 37 (88.1%, 95% CI, 77.9-98.3) in the warfarin group). CONCLUSIONS: These findings regarding efficacy and safety support the consideration of dabigatran etexilate therapy as a viable treatment option for Chinese patients with CVT.


Assuntos
Anticoagulantes , Dabigatrana , Trombose Intracraniana , Trombose Venosa , Varfarina , Humanos , Dabigatrana/uso terapêutico , Dabigatrana/efeitos adversos , Masculino , Feminino , Varfarina/uso terapêutico , Varfarina/efeitos adversos , Pessoa de Meia-Idade , Trombose Venosa/tratamento farmacológico , Adulto , Anticoagulantes/uso terapêutico , Anticoagulantes/efeitos adversos , Trombose Intracraniana/tratamento farmacológico , Idoso , China/epidemiologia , Hemorragia/induzido quimicamente , Antitrombinas/uso terapêutico , Antitrombinas/efeitos adversos , Adulto Jovem , Adolescente , Resultado do Tratamento , Idoso de 80 Anos ou mais , População do Leste Asiático
5.
Environ Sci Technol ; 58(10): 4824-4836, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38408018

RESUMO

Electrochemically converting nitrate, a widely distributed nitrogen contaminant, into harmless N2 is a feasible and environmentally friendly route to close the anthropogenic nitrogen-based cycle. However, it is currently hindered by sluggish kinetics and low N2 selectivity, as well as scarce attention to reactor configuration. Here, we report a flow-through zero-gap electrochemical reactor that shows a high performance of nitrate reduction with 100% conversion and 80.36% selectivity of desired N2 in the chlorine-free system at 100 mg-N·L-1 NO3- while maintaining a rapid reduction kinetics of 0.07676 min-1. More importantly, the mass transport and current utilization efficiency are significantly improved by shortening the inter-electrode distance, especially in the zero-gap electrocatalytic system where the current efficiency reached 50.15% at 5 mA·cm-2. Detailed characterizations demonstrated that during the electroreduction process, partial Cu(OH)2 on the cathode surface was reconstructed into stable Cu/Cu2O as the active phase for efficient nitrate reduction. In situ characterizations revealed that the highly selective *NO to *N conversion and the N-N coupling step played crucial roles during the selective reduction of NO3- to N2 in the zero-gap electrochemical system. In addition, theoretical calculations demonstrated that improving the key intermediate *N coverage could effectively facilitate the N-N coupling step, thereby promoting N2 selectivity. Moreover, the environmental and economic benefits and long-term stability shown by the treatment of real nitrate-containing wastewater make our proposed electrocatalytic system more attractive for practical applications.


Assuntos
Nitratos , Águas Residuárias , Nitratos/química , Eletrodos , Nitrogênio/análise , Nitrogênio/química , Cinética
6.
Huan Jing Ke Xue ; 44(7): 3957-3969, 2023 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-37438294

RESUMO

Substituted polycyclic aromatic hydrocarbons (SPAHs) are a type of emerging pollutant that widely exist in the environment, which also exhibit carcinogenicity, mutagenicity, and teratogenicity. These pollutants belong to toxic pollutants because of their similar structures to polycyclic aromatic hydrocarbons (PAHs). Their environmental behavior and ecological risk have attracted increasing attention. Based on a literature review, we found a new breakthrough in the source, distribution, behavior, and risk of SPAHs with comparison to traditional pollutants PAHs. This paper reviewed the current research progress on the environmental occurrence and photochemical behavior of SPAHs. Their sources, formation mechanisms, and distribution characteristics in the multimedia environment were highlighted, and the photochemical transformation kinetics, pathways, and affecting factors of SPAHs in water, ice, and other media were discussed. Furthermore, the research prospects about the environmental behavior and risk of SPAHs were proposed.

7.
Chemosphere ; 335: 139180, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37302500

RESUMO

The secure and harmless disposal for Cr-bearing tannery sludge (Cr-TS) has attracted an increasing concern, due to potentially adverse effect on ecosystem and human health. A greener alternative method about "waste treatment with waste" for thermally stabilizing real Cr-TS was developed via employing coal fly ash (CA) as dopants in this research. The co-heat treatment of Cr-TS and CA was carried out at the temperature range of 600-1200 °C to investigate the oxidation of Cr(III), immobilization of chromium and leaching risk of the sintered products, and the mechanism of chromium immobilization was further explored. The results indicate that the doping of CA can significantly inhibit the oxidation of Cr(III) and immobilize chromium by incorporating chromium into spinel and uvarovite microcrystal. At the temperature higher than 1000 °C, most of chromium can be converted into stable crystalline phases. Furthermore, a prolonged leaching test was conducted to study the leaching toxicity of chromium in sintered products, indicating that leaching content of chromium is much less than the regulatory limit. This process is a feasible and promising alternative for immobilization of chromium in Cr-TS. The research findings are supposed to offer a theoretical foundation and strategy choice for thermal stabilization of chromium, as well as safety and harmless disposal of Cr-containing hazardous waste.


Assuntos
Cromo , Esgotos , Humanos , Cromo/química , Cinza de Carvão , Temperatura Alta , Carvão Mineral , Ecossistema , Incineração
8.
Mar Pollut Bull ; 191: 114883, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37105055

RESUMO

Organophosphate esters (OPEs) are widely distributed in surface water systems, but limited information was available on the spatial occurrence and ecological risks of OPEs in the Bohai Sea. In this study, 89 water samples in the Bohai Sea and the five surrounding rivers were investigated for the determination of 15 OPEs. The concentration of ∑15OPEs ranged from 373.20 to 2931.27 ng·L-1 in the river water and 137.81 to 2641.30 ng·L-1 in the seawater, with high levels of OPEs in Liaodong Bay. Tris(2-chloroethyl) phosphate (TCEP, 10- 92 %) and triethyl phosphate (TEP, 5- 64 %) were dominant for OPEs. The correlation analysis, principal component analysis and hierarchical cluster analysis suggested the conjunction of municipal wastewater via river input and maritime shipping was the main source of OPEs in the Bohai Sea. The ecological risk assessment indicated that the individual OPEs arise low ecological risks in the Bohai Sea, while medium ecological risks of ∑15OPEs are in minority river samples.


Assuntos
Retardadores de Chama , Poluentes Químicos da Água , Monitoramento Ambiental , Retardadores de Chama/análise , Poluentes Químicos da Água/análise , Ésteres/análise , Organofosfatos/análise , Água do Mar , Água/análise , China
9.
Neurol Clin Pract ; 13(2): e200122, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37064580

RESUMO

Objectives: Anticoagulation therapy for cerebral venous sinus thrombosis (CVST) with antithrombin (AT) deficiency due to SERPINC1 mutation does not often yield the expected outcomes. Argatroban may be effective for thrombophilia caused by SERPINC1 mutation. However, argatroban resistance deserves attention. Methods: We report a case of a 19-year-old man who was admitted to the hospital with sudden headache, nausea, vomiting, and eye swelling for 3 days. Brain MRI on admission showed multifocal CVST. Results: SERPINC1 mutation (exon1, c.40delA: [p.R14Gfs*17]) combined with hereditary AT deficiency (AT activity was 50% [reference range: 80%-120%]) was detected in this patient. A high dose of anticoagulation treatment with argatroban did not improve the activated partial thromboplastin time (APTT) level to the target range (1.5-3 times over the initial baseline level) for this case. We chose adjunctive anticoagulation (argatroban-combined low-molecular-weight heparin), and the APTT gradually reached the target level. At 3-month follow-up, no recurrence of headache or any systemic hemorrhage was found and the ultrasonography of the optic nerve sheath showed normal. Magnetic resonance black blood thrombosis imaging suggested thrombus absorption. Discussion: Argatroban resistance may be associated with thrombin receptor saturation and deserves attention. The use of adjunctive anticoagulants may be the optimum strategy during acute and subacute phases of CVST with AT deficiency due to SERPINC1 mutation.

10.
J Colloid Interface Sci ; 638: 26-38, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36731216

RESUMO

The electrochemical nitrate reduction reaction (NitRR) affords a sustainable way for nitrate mitigation and ammonia synthesis, but there are still some problems such as poor nitrate conversion, low ammonia selectivity, and slow reaction kinetics. A clear structure-performance relationship is essential for designing efficient catalysts and understanding the reaction mechanisms. Herein, ultrathin nickel metal-organic framework (Ni-MOF) nanosheets supported on Ni foam featuring a well-defined stable structure, large electrochemically active surface area, and low electron transport resistance were prepared by a one-step solvothermal process. At -1.4 V, the nitrate reduction, rate constant, ammonia selectivity, and yield reached 96.4%, 0.448 h-1, 80%, and 110.13 ug·h-1·cm-2, respectively. Experimental and theoretical studies demonstrated that the hydroxyl-ligated Ni atoms exhibited higher nitrate adsorption properties and lower activation energy towards NitRR compared to carboxylic acid-ligated Ni atoms. Mechanism investigations revealed a nitrate-to-ammonia reaction pathway involving multiple intermediate species on Ni-MOF nanosheet catalysts. This work offers a new avenue to construct highly efficient electrocatalysts for the selective transformation of nitrate to valuable ammonia.


Assuntos
Estruturas Metalorgânicas , Nitratos , Amônia , Níquel , Teoria da Densidade Funcional
11.
CNS Neurosci Ther ; 29(3): 957-967, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36601660

RESUMO

AIMS: To investigate the predicted factors influencing the outcomes in acute ischemic stroke (AIS) patients who received tirofiban after endovascular treatment (EVT) and the optimal administration of tirofiban. METHODS: In this retrospective study, AIS patients who received EVT followed by tirofiban between January 2017 and October 2021 were enrolled. The dose and duration of tirofiban were adjusted by trained clinicians according to the patient's clinical status. A reduction of at least four points on the National Institutes of Health Stroke Scale (NIHSS) after tirofiban compared with that before tirofiban was defined as an effective response. A modified ranking scale (mRS) of 0-2 was defined as a favorable outcome at a 90-day follow-up. RESULTS: A total of 260 consecutive patients were enrolled, and 36.5% of patients achieved a favorable outcome. The modified thrombolysis in cerebral infarction (mTICI) 2b-3 occurred in 93.5% of patients. Symptomatic intracerebral hemorrhage (sICH) occurred in 6.2% of patients, and the mortality at 90-day follow-up was 16.9%. Duration of tirofiban >24 h (adjusted OR: 2.545; 95% CI: 1.008-6.423; p = 0.048) and effective response to tirofiban (adjusted OR: 25.562; 95% CI: 9.794-66.715; p < 0.001) were related to the favorable outcome (mRS 0-2). Higher NIHSS (adjusted OR: 0.855; 95% CI: 0.809-0.904; p < 0.001) and glucose level on admission (adjusted OR: 0.843; 95% CI: 0.731-0.971; p = 0.018) were predictive for the unfavorable outcome (mRS 3-6). CONCLUSIONS: An effective response to tirofiban is an independent factor in predicting the long-term efficacy outcome, and extending the duration of tirofiban is beneficial for neurological improvement.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Tirofibana/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/cirurgia , Estudos Retrospectivos , Isquemia Encefálica/tratamento farmacológico , Resultado do Tratamento
12.
J Neurol ; 270(4): 2084-2095, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36596867

RESUMO

OBJECTIVES: To investigate the relationship between the initiation time of anticoagulation after endovascular treatment (EVT) and the outcomes in atrial fibrillation (AF)-related acute ischemic stroke (AIS) patients. METHODS: In this prospective registry study, from March 2013 to June 2022, patients with anterior circulation territories AF-related AIS who underwent EVT within 24 h were included. The primary outcome was favorable [modified Rankin Scale (mRS) 0-1) at ninety days and the secondary outcome was hemorrhage events after anticoagulants. Factors affecting the outcomes were pooled into multivariate regression and ROC curve analysis. RESULTS: Of 234 eligible patients, there were 63 (26.9%) patients achieved a favorable outcome. The symptomatic intracranial hemorrhage (sICH), ICH, and systemic hemorrhage events after anticoagulants occurred in 8 (3.4%), 28 (12.0%), and 39 (16.7%) patients, severally. A longer EVT to anticoagulation time (p = 0.033) was associated with an unfavorable outcome (mRS 3-6). An earlier EVT to anticoagulation time was the independent risk factor of sICH (p = 0.043), ICH (p = 0.005), and systemic hemorrhage (p = 0.005). There was no significant difference in recurrent AIS/ transient ischemic attack (TIA) or mortality among patients who started anticoagulation at ≤ 4 days, ≥ 15 days, or 4 to 15 days. The optimum cut-off for initiating anticoagulants to predict a favorable outcome and hemorrhage events was 4.5 days and 3.5 days after EVT, respectively. CONCLUSIONS: In AF-related AIS, the time of EVT to anticoagulation is an independent factor of the functional outcome and hemorrhage events after anticoagulation. The optimal initiate time of anticoagulant after EVT is 4.5 days. CLINICALTRIALREGISTER: NCT03754738.


Assuntos
Fibrilação Atrial , Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Anticoagulantes/efeitos adversos , Fibrilação Atrial/complicações , Fibrilação Atrial/cirurgia , Isquemia Encefálica/complicações , Isquemia Encefálica/cirurgia , Procedimentos Endovasculares/efeitos adversos , Hemorragia , Hemorragias Intracranianas/etiologia , AVC Isquêmico/complicações , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/cirurgia , Trombectomia/efeitos adversos , Resultado do Tratamento
13.
J Environ Sci (China) ; 124: 139-145, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182124

RESUMO

The photochemical behavior of organic pollutants in ice is poorly studied in comparison to aqueous photochemistry. Here we report a detailed comparison of ice and aqueous photodegradation of two representative OH-PAHs, 2-hydroxyfluorene (2-OHFL) and 9-hydroxyfluorene (9-OHFL), which are newly recognized contaminants in the wider environment including colder regions. Interestingly, their photodegradation kinetics were clearly influenced by whether they reside in ice or water. Under the same simulated solar irradiation (λ > 290 nm), OHFLs photodegraded faster in ice than in equivalent aqueous solutions and this was attributed to the specific concentration effect caused by freezing. Furthermore, the presence of dissolved constituents in ice also influenced photodegradation with 2-OHFL phototransforming the fastest in 'seawater' ice (k = (11.4 ± 1.0) × 10-2 min-1) followed by 'pure-water' ice ((8.7 ± 0.4) × 10-2 min-1) and 'freshwater' ice ((8.0 ± 0.7) × 10-2 min-1). The presence of dissolved constituents (specifically Cl-, NO3-, Fe(III) and humic acid) influences the phototransformation kinetics, either enhancing or suppressing phototransformation, but this is based on the quantity of the constituent present in the matrixes, the specific OHFL isomer and the matrix type (e.g., ice or aqueous solution). Careful derivation of key photointermediates was undertaken in both ice and water samples using tandem mass spectrometry. Ice phototransformation exhibited fewer by-products and 'simpler' pathways giving rise to a range of hydroxylated fluorenes and hydroxylated fluorenones in ice. These results are of importance when considering the fate of PAHs and OH-PAHs in cold regions and their persistence in sunlit ice.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Compostos Férricos , Fluorenos/análise , Substâncias Húmicas/análise , Gelo/análise , Cinética , Fotólise , Hidrocarbonetos Policíclicos Aromáticos/análise , Água/química , Poluentes Químicos da Água/análise
14.
Chemistry ; 28(70): e202202190, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36125783

RESUMO

C-N bond formation takes on a critical significance in reactions of organic synthesis, material production and pharmaceutical manufactory. Chan-Lam has proposed a useful methodology to furnish secondary arylamides under mild conditions. However, when chiral sulfinamides serve as the coupling precursors, the Cu-catalyzed coupling reaction is found with low efficacy. Complex side-products are generated under classic conditions. Moreover, it led to the racemization of the coupling product. In this study, an optimized Ni-catalyzed Chan-Lam type coupling conditions were proposed, which resulted in clean conversion from chiral sulfinamides and arylboronic acids to offer N-aryl sulfinamides efficiently and enantioretentively. The trans-N1 ,N2 -dimethylcyclohexane-1,2-diamine was proven as the most efficient ligand. Under the optimized conditions, a series of chiral N-aryl sulfinamides was prepared with high chemical yield without racemization. Furthermore, a plausible and novel mechanism was proposed. Interestingly, the method could efficiently furnish a wide variety of C-X bonds by coupling arylboronic acids with different nucleophiles.


Assuntos
Catálise , Técnicas de Química Sintética , Ligantes
15.
Ecotoxicol Environ Saf ; 240: 113676, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35653974

RESUMO

Chromium (Cr) is mainly found in the form of organic-Cr(III) complexes in the natural environment and industrial waste. The widespread existence of composite contaminants composed of organic matter (OM) and Cr pose a serious ecological threat, and its potential interaction and removal need to be further summarised. Organic ligands, such as carbohydrates, nitrogen compounds, phenolic compounds, humus substances (HS), and low molecular weight organic acids (LMWOAs), play an important role in governing the speciation, mobility, and absorption and desorption of Cr in the environment. Moreover, growing evidence indicates that oxygen-containing functional groups (e.g., carboxyl, hydroxyl, and phosphate) are closely related to the complexation of Cr(III). Advanced oxidation processes (AOPs) are efficient and widely applicable technologies. However, the re-complexation of oxidation intermediates with Cr(III) and the formation and accumulation of much more toxic Cr(VI) species hinder the possible utilisation of AOPs. In this paper, the sources and harmful effects of organic-Cr(III) complexes are reported in detail. The complexation behaviour and structure of the organic-Cr(III) complexes are also described. Subsequently, the application of AOPs in the decomplexation and degradation of organic-Cr(III) complexes is summarised. This review can be helpful for developing technologies that are more efficient for organic-Cr(III) complex removal and establishing the scientific background for reducing Cr discharge Cr into the environment.


Assuntos
Cromo , Resíduos Industriais , Cromo/química , Radical Hidroxila , Compostos Orgânicos , Oxirredução
16.
Materials (Basel) ; 15(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35591512

RESUMO

Cement-stabilized dredged sediment (CDS) when used as a new road construction material cannot only solve the problem of abandoned sediment disposal, but also effectively save natural soil resources. This study aimed to evaluate the strength and permeability of CDS and establish corresponding prediction models from the perspective of a stabilization mechanism. The soil-water composition and pore size distribution were investigated by the nuclear magnetic resonance (NMR) technique. The results demonstrated that more liquid pore water inside the CDS specimen transformed into combined water with cement hydration. The amount of combined water, which essentially characterized the hydration process of cement, presented a linear relationship with log (t). The cementation and filling action of hydrates resulted in the transformation of large pores into smaller ones, hence the optimal pore size decreased with an increasing curing period and cement content. The stress-strain curves and hydraulic conductivity were determined based on unconfined compression and flexible wall penetration tests, respectively. The unconfined compressive strength increased exponentially with the amount of combined water, and the functional correlations of hydraulic conductivity and micropore parameters were established. The reliability of the NMR technique as a new method to study the microscopic evolution mechanism of the strength and permeability of CDS was further verified by scanning electron microscopy and mercury intrusion porosimetry tests.

17.
Mar Pollut Bull ; 179: 113725, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35567963

RESUMO

Pyrethroids are increasingly receiving attention as aqueous micropollutants, but their presence has been reported only in a few small coastal areas. In this study, we investigated the distribution, sources, and risks of nine pyrethroids in large marine zones. The 40 seawater samples were collected from the South Yellow Sea (SYS) and East China Sea (ECS) in China, during the spring of 2020, using a high-volume, solid-phase extraction method. The total pyrethroid concentrations ranged from 0.72 to 1.82 ng L-1 in the SYS and from 0.02 to 11.0 ng L-1 in the ECS. We used cluster analysis to classify pollutant sources into five categories, and discussed the influence of sources on the transport and distribution of pyrethroids in each group. Ecological risk assessment indicated that pyrethroids pose a high risk to crustaceans and a negligible risk to others. These results are important for understanding the behavior of pyrethroids in marine environments.


Assuntos
Piretrinas , Poluentes Químicos da Água , China , Monitoramento Ambiental , Oceanos e Mares , Piretrinas/análise , Água do Mar , Poluentes Químicos da Água/análise
18.
Nanoscale ; 14(9): 3579-3588, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35179172

RESUMO

Electrocatalytic oxidation is regarded as an effective technique for decomposing refractory organic compounds like perfluorooctanoic acid (PFOA). However, achieving highly efficient and long-life electrodes is still a great challenge. Herein, Ti/RuO2-IrO2@Pt anodes consisting of Pt4+ and Pt0 species were fabricated by combining modified microemulsion technology with a calcination process, in which Pt nanoparticles were highly dispersed and encapsulated in Ru-Ir composite oxides to form a strong metal-support interaction (SMSI) structure. The as-constructed SMSI layer on the Ti/RuO2-IrO2@Pt anode resulted in the improvement of the charge transfer capability and also increased the degradation (99.30%) and mineralization (91.32%) of PFOA during the electrochemical oxidation process. Notably, the service lifetime of Ti/RuO2-IrO2@Pt anodes was remarkably improved from 24 to 42.3 h compared to commercial Ti/RuO2-IrO2 anodes. Moreover, the possible degradation mechanism of PFOA was also speculated through the detection of short-chain perfluorocarboxylic acids and reactive radicals. These results not only revealed that the concept and methodology of SMSI could be an effective way for constructing highly efficient and stable electrocatalysts but also greatly advanced fundamental understanding.

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