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1.
Environ Sci Technol ; 57(27): 10117-10126, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-37364020

RESUMEN

Electrocatalytic reduction of nitrate to NH3 (NO3RR) on Cu offers sustainable NH3 production and nitrogen recycling from nitrate-contaminated water. However, Cu affords limited NO3RR activity owing to its unfavorable electronic state and the slow proton transfer on its surface, especially in neutral/alkaline media. Furthermore, although a synchronous "NO3RR and NH3 collection" system has been developed for nitrogen recycling from nitrate-laden water, no system is designed for natural water that generally contains low-concentration nitrate. Herein, we demonstrate that depositing Cu nanoparticles on a TiO2 support enables the formation of electron-deficient Cuδ+ species (0 < δ ≤ 2), which are more active than Cu0 in NO3RR. Furthermore, TiO2-Cu coupling induces local electric-field enhancement that intensifies water adsorption/dissociation at the interface, accelerating proton transfer for NO3RR on Cu. With the dual enhancements, TiO2-Cu delivers an NH3-N selectivity of 90.5%, mass activity of 41.4 mg-N h gCu-1, specific activity of 377.8 mg-N h-1 m-2, and minimal Cu leaching (<25.4 µg L-1) when treating 22.5 mg L-1 of NO3--N at -0.40 V, outperforming most of the reported Cu-based catalysts. A sequential NO3RR and NH3 collection system based on TiO2-Cu was then proposed, which could recycle nitrogen from nitrate-contaminated water under a wide concentration window of 22.5-112.5 mg L-1 at a rate of 209-630 mgN m-2 h-1. We also demonstrated this system could collect 83.9% of nitrogen from NO3--N (19.3 mg L-1) in natural lake water.


Asunto(s)
Nanopartículas , Nitratos , Nitratos/química , Protones , Cobre , Nitrógeno , Agua
2.
J Environ Sci (China) ; 127: 652-666, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36522094

RESUMEN

An ultra-efficient electro-Fenton catalyst with porous carbon coated Fe-Mo metal (FeMo@PC), was prepared by calcining MIL-53(Fe)@MoO3. This FeMo@PC-2 exhibited impressive catalytic performance for sulfamethazine (SMT) degradation with a high turnover frequency value (7.89 L/(g·min)), much better than most of reported catalysts. The mineralization current efficiency and electric energy consumption were 83.2% and 0.03 kWh/gTOC, respectively, at low current (5 mA) and small dosage of catalyst (25.0 mg/L). The removal rate of heterogeneous electro-Fenton (Hetero-EF) process catalyzed by FeMo@PC-2 was 4.58 times that of Fe@PC/Hetero-EF process. Because the internal-micro-electrolysis occurred between PC and Fe0, while the co-catalysis of Mo accelerated the rate-limiting step of the Fe3+/Fe2+ cycle and greatly improved the H2O2 utilization efficiency. The results of radical scavenger experiments and electron paramagnetic resonance confirmed the main role of surface-bound hydroxyl radical oxidation. This process was feasible to remove diverse organic contaminants such as phenol, 2,4-dichlorophenoxyacetic acid, carbamazepine and SMT. This paper enlightened the importance of the doped Mo, which could greatly improve the activity of the iron-carbon heterogeneous catalyst derived from metal-organic frameworks in EF process for efficient removal of organic contaminants.


Asunto(s)
Peróxido de Hidrógeno , Contaminantes Químicos del Agua , Carbono , Catálisis , Oxidación-Reducción , Porosidad , Sulfametazina , Contaminantes Químicos del Agua/análisis
3.
Psychol Health Med ; 27(8): 1682-1692, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-33879007

RESUMEN

Consequences of prenatal maternal depressive symptoms on infant health are well established. But the results of infants' sex differences of such consequences are mixed. The current study examines whether any association exists between prenatal maternal depressive symptoms and infant physical health different for the sex of newborns. A sample of 84 women pregnant with twins reported depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) in the late gestational stage. The Apgar scores of newborns were assessed by healthcare providers at 1, 5, and 10 minutes after birth. The relationship of maternal prenatal depressive symptoms and newborns' physical health was moderated by infant sex. Higher depressive symptoms were associated with a lower Apgar index among newborn boys but not girls. Fetus environment or biomarkers related to sex may be a key mechanism of the effect of prenatal depression symptoms on newborns' health. Tailored interventions targeting maternal depression symptoms may be warranted.


Asunto(s)
Depresión Posparto , Mujeres Embarazadas , China/epidemiología , Depresión/complicaciones , Depresión/epidemiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Madres , Embarazo
4.
Environ Sci Technol ; 51(18): 10519-10525, 2017 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-28845969

RESUMEN

Here we report a facile and cost-effective wet-chemical approach to the synthesis of calcium sulfate hemihydrate nanowires (HH NWs, CaSO4·0.5H2O), and their robust performance in immobilizing water molecules to the crystal lattice of CaSO4 and then separating them from a surfactant-stabilized water-in-oil emulsion (mean droplet size of around 1.2 µm). Every gram of HH NWs are capable of treating 20 mL emulsion (water content: 10.00 mg mL-1) with a separation efficiency of 99.23% at room temperature, and this efficiency can be further improved by tuning the surface charge density of HH. Along with the water immobilization, HH NWs are converted to large cubic-like calcium sulfate dihydrate microparticles (DH, CaSO4·2H2O, mean size: 50 µm), and the accompanied size increment enables efficient collection of the solid phase from oil. DH microparticles can be regenerated into HH NWs, which retain the high performance of the original NWs. Such a unique renewable feature improves the economics of our method and simultaneously prevents the secondary pollution. Further economic evaluation finds that purification of every cubic meters of emulsion (water content: 10.00 mg mL-1) will cost about $34.18 for HH NWs, much lower than the $490.78 for the previously reported HH NPs, and $11 052.05-$23 420.32 Fe3O4 NP-based adsorbents, respectively. With the high efficiency, easy collection, low cost, and renewable feature, HH NWs show highly promising applications in the field of oil purification and recycle.


Asunto(s)
Sulfato de Calcio , Nanocables , Emulsiones , Tensoactivos , Agua
5.
Artículo en Inglés | MEDLINE | ID: mdl-39016339

RESUMEN

STUDY DESIGN: Prospective cohort study. OBJECTIVE: Investigating the ability of a 6-minute walking test (6MWT) to assess functional status in patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: The 6MWT provides an objective assessment of a patient's ability to walk. There is the potential for its application to the assessment of functional status in patients with CSM. MATERIALS AND METHODS: One hundred and thirty-five patients from our institution were prospectively enrolled from July 2022 to August 2023. A control group of age- and sex-matched healthy individuals was established. The 6MWT was conducted in strict accordance with established guidelines. The Nurick score, the Prolo score, the Cooper-myelopathy-scale score (CMS), the Japanese Orthopedic Association score (JOA) and the European-myelopathy-scale score (EMS) were assessed preoperatively. Visual Analog Scale (VAS) for pain or numbness and Oswestry Neck Disability Index (NDI) were also collected. Radiographic parameters were measured and recorded. Continuous variables between patients and controls were compared by applying the t-test. The chi-square test was used to compare gender ratios between groups. Pearson's correlation analysis was used to analyze the association between continuous variables and ordinal variables. Subgroups of CSM patients were analyzed according to global spinal alignment types, based on whether the SVA was greater than or equal to 50 mm. Clinical scores and imaging parameters were compared by t-test. RESULTS: The preoperative 6-minute walking distance (6MWD) of CSM patients was 309.34 ± 116.71 m, which was significantly lower than that of the controls (464.30 ± 52.59 m, P<.01). The 6MWD was significantly correlated with scores on all clinical scales except the VAS. CMS Lower extremity score had the strongest correlation with preoperative 6MWD in CSM patients (r=-.794 , P<.01). Of the sagittal alignment parameters, only C7 sagittal vertical axis (SVA) and T1 slope were significantly correlated with 6MWD(r=-.510,-0.360, respectively). CSM patients with SVA greater than 50 mm had significantly lower 6MWD than CSM patients with SVA less than or equal to 50 mm (168.00 ± 137.26 vs 346.24 ± 84.27 m, P<.01). CONCLUSIONS: The 6MWD of CSM patients was significantly lower than that of the healthy population and correlated well with commonly used clinical scales. The 6MWD can potentially assist in the assessment of functional status in patients with CSM.

6.
Bone Res ; 12(1): 20, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38553442

RESUMEN

To date, several molecules have been found to facilitate iron influx, while the types of iron influx channels remain to be elucidated. Here, Piezo1 channel was identified as a key iron transporter in response to mechanical stress. Piezo1-mediated iron overload disturbed iron metabolism and exaggerated ferroptosis in nucleus pulposus cells (NPCs). Importantly, Piezo1-induced iron influx was independent of the transferrin receptor (TFRC), a well-recognized iron gatekeeper. Furthermore, pharmacological inactivation of Piezo1 profoundly reduced iron accumulation, alleviated mitochondrial ROS, and suppressed ferroptotic alterations in stimulation of mechanical stress. Moreover, conditional knockout of Piezo1 (Col2a1-CreERT Piezo1flox/flox) attenuated the mechanical injury-induced intervertebral disc degeneration (IVDD). Notably, the protective effect of Piezo1 deficiency in IVDD was dampened in Piezo1/Gpx4 conditional double knockout (cDKO) mice (Col2a1-CreERT Piezo1flox/flox/Gpx4flox/flox). These findings suggest that Piezo1 is a potential determinant of iron influx, indicating that the Piezo1-iron-ferroptosis axis might shed light on the treatment of mechanical stress-induced diseases.


Asunto(s)
Ferroptosis , Degeneración del Disco Intervertebral , Núcleo Pulposo , Animales , Ratones , Estrés Mecánico , Mitocondrias , Hierro , Ratones Noqueados , Canales Iónicos/genética
7.
J Hazard Mater ; 424(Pt D): 127674, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-34763926

RESUMEN

The reduced S-modified MIL-53(Fe) was prepared by sulfurizing MIL-53(Fe) at low temperature, which was an efficient electro-Fenton catalyst at wide pH range (3-9) for sulfamethazine (SMT) degradation. The best temperature and MIL-53(Fe)/S ratio were 350 °C and 1:2, at which the BET surface area was much enlarged. The MIL-53(Fe) surface was etched by S to many 2D nanosheets with the thickness of ~50 nm, while S2-2 replaced OH- to coordinate with Fe2+ and increased the Fe2+ content, which improved the catalytic performance. Even at initial pH of 7.0, the SMT removal was 95.8%, and the rate constant (k) in the Hetero-EF process was 16-folds of that in the Homo-EF process. The turnover frequency (TOFd) value of MIL-53(Fe)/S(1:2)-350 was 0.48 L g-1 min-1, which was 6.8 times that of commercial FeS2. The S2-2in catalyst adjusted the pH superfast, and promoted the generation of Fe2+ and thus efficiently activating H2O2 to form surface ·OH, which was verified to be the main radical by EPR and radical scavenger experiments. This catalyst showed promising prospect for environmental application and could be regenerated by sulfidation method. S-doped MIL-53(Fe) was an excellent pH regulator, thus promoting promising application in Hetero-EF processes.


Asunto(s)
Sulfametazina , Contaminantes Químicos del Agua , Peróxido de Hidrógeno , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/análisis
8.
J Hazard Mater ; 434: 128887, 2022 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-35430458

RESUMEN

The electrochemical reduction of nitrate to ammonia (ERNA) has become a green treatment technology for nitrate wastewater. However, strong adsorption for product caused high activation energy for product desorption in scaling relations, blocking activity of electrocatalyst in ERNA. Density functional theory (DFT) calculations indicated that constructing dual active sites (Cu and Co3O4) could achieve strong adsorption of nitrate (-2.91 eV) with low desorbing energy barrier of ammonia (0.13 eV), breaking scaling relations. This dual active sites Co3O4/Cu electrode achieved a high ammonia yield rate of 684 µg mgcat-1 h-1 with 94.6% faradic efficiency, surpassing single active site Co3O4 and Cu electrodes. For mechanism, In-situ electrochemical characterization found the vital intermediates of *NH and *NH2, demonstrating that indirect reduction was the main pathway on Co3O4/Cu electrode. Thus, it is believed that building dual active sites on electrode is a reliable strategy to enhance ERNA for purifying industrial wastewater polluted by nitrate.


Asunto(s)
Amoníaco , Nitratos , Amoníaco/química , Dominio Catalítico , Cobalto , Electrodos , Nitratos/química , Óxidos de Nitrógeno , Óxidos , Aguas Residuales
9.
J Hazard Mater ; 430: 128402, 2022 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-35149500

RESUMEN

The oxygen reduction reaction (ORR) activated by Fe0 in the presence of three aminopolycarboxylic acids (CAs), i.e. nitrilotriacetic acid (NTA), ethylenediamine-N,N'-disuccinic acid (EDDS) and ethylenediaminetetraacetic acid (EDTA), for the degradation of sulfamethazine (SMT) was investigated. At optimum conditions, Fe0/EDDS/O2, Fe0/EDTA/O2 and Fe0/NTA/O2 systems presented SMT removal of 58.2%, 75.3% and 93.8%, respectively, being much higher than that in the Fe0/O2 system (1.36%). The generation of surface-bound Fe2+ (Fe2+) and dissolved iron ion was enhanced by CAs. ORR through a two-electron transfer pathway was mainly responsible for H2O2 generation in NTA and EDTA systems, while a single-electron ORR was the major source for producing H2O2 in EDDS system. •OH produced by the homogeneous reaction of Fe2+ and H2O2 was the main species for SMT degradation. Fe0/EDDS/O2 produced more 1O2 than Fe0/EDTA/O2 and Fe0/NTA/O2; however, the radical contributed negligibly to SMT removal. The caging effect of CAs might be a major factor influencing the reaction rate of Fe2+ and O2. CAs provided protons to accelerate the electron transfer, the production of Fe2+ and thus the contaminant removal. This study is of great significance for revealing ORR mechanisms in the Fe0-chelate system.


Asunto(s)
Hierro , Oxidantes , Electrones , Peróxido de Hidrógeno , Oxidación-Reducción , Oxígeno , Protones
10.
ACS Appl Mater Interfaces ; 13(24): 28348-28358, 2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34124878

RESUMEN

As nitrate contamination causes serious environmental problems, it is necessary to develop stable and efficient electrocatalysts for efficient electrochemical nitrate reduction reaction (ENRR). Here, a nonprecious Co3O4/carbon felt (CF) electrode with a 3D structure was prepared by integrating electrodeposition with calcination methods. This 3D structured Co3O4/CF electrode exhibits a high-rate constant of 1.18 × 10-4 s-1 cm-2 for the ENRR, surpassing other Co3O4 electrodes in previous literature. Moreover, it also has an excellent stability with a decrease of 6.4% after 10 cycles. Density functional theory calculations, electron spin resonance analysis, and cyclic voltammetry were performed to study the mechanism of the ENRR on the Co3O4/CF electrode, proving that atomic H* (indirect pathway) plays a prominent role in NO3- reduction and clarifying the synergistic effect of Co(III) and Co(II) in the Co(II)-Co(III)-Co(II) redox cycle for the ENRR: Co(III) prefers the adsorption of NO3- and Co(II) favors the production of H*. Based on this synergy, a relatively large amounts of Co(II) on the surface of the Co3O4/CF electrode (1.3 Co(II)/Co(III) ratio) was maintained by controlling the temperature of calcination to 200 °C with a lower energy barrier of H* formation of 0.46 eV than other ratios, which is beneficial for forming H* and enhancing the performance of the ENRR. Thus, this study suggests that building 3D structure and optimizing Co(II)/Co(III) ratio are important for designing efficient Co3O4 electrocatalyst for ENRR.

11.
Anxiety Stress Coping ; 33(4): 466-478, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32192362

RESUMEN

Background: Pregnancy-related stress in women who are pregnant with twins, may increase the risk of adverse emotional outcomes such as depressive symptoms and anxiety. Possible protective coping resources of pregnant women could be their socio-economic background, their marital relationship quality (dyadic satisfaction), or their emotional intelligence. Objectives: The study aims at exploring the mechanisms by which protective factors are associated with pregnancy-related stress and adverse emotional outcomes such as depression and anxiety. Methods and Design: Hospitals in Beijing, China, provided questionnaire data from 134 women who were pregnant with twins. Pregnancy-related stress, anxiety, depression, and three resource factors (socio-economic status, emotional intelligence, and dyadic marital satisfaction) were measured. Results: The experience of pregnancy-related stress mediated between resource factors and adverse consequences. While some socio-economic background variables had a main effect, personal and social resources exerted a buffer effect: emotional intelligence as well as dyadic satisfaction buffered the negative effects of stress on prenatal anxiety and depressive symptoms, respectively. Conclusions: A unique mechanism was identified that may explain how protective coping resources are associated with psychosocial stress and adverse outcomes in pregnant at-risk women. Future studies should substantiate this finding using longitudinal research designs.


Asunto(s)
Ansiedad/psicología , Depresión/psicología , Inteligencia Emocional , Satisfacción Personal , Complicaciones del Embarazo/psicología , Embarazo Gemelar/psicología , Estrés Psicológico/psicología , Adaptación Psicológica , Adulto , Beijing , Femenino , Humanos , Embarazo , Encuestas y Cuestionarios , Adulto Joven
12.
Nanoscale ; 11(34): 15892-15899, 2019 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-31464326

RESUMEN

Identifying the rate-determining step over the catalysts and clarifying the underlying mechanisms are crucial for maximizing the electrocatalytic hydrodechlorination (EHDC) efficiency for detoxification of the chlorophenol pollutants in water. Here, monodisperse palladium nanoparticles (Pd NPs) separately supported on carbon (C) and titanium nitride (TiN) were synthesized as two model catalysts. The support effects on EHDC efficiency, kinetics and current efficiency towards 2,4-dichlorophenol (2,4-DCP), and the electronic structure of Pd and its binding strengths with 2,4-DCP, phenol and Cl- (the primary EHDC product) were investigated by experimental and density functional theory (DFT) analyses. The low current efficiency (<30%) of both catalysts and the good description of EHDC kinetics by the Langmuir-Hinshelwood model suggest that the 2,4-DCP coverage on Pd, rather than the well-known adsorbed hydrogen generation, determines EHDC efficiency. Furthermore, the superior EHDC efficiency on TiN-Pd (96.4% vs. 80.9% on C-Pd), coupled with the weakened adsorption of 2,4-DCP and phenol on TiN-supported Pd, demonstrates that the 2,4-DCP coverage is largely influenced by phenol due to its poisoning effect by blocking active sites, and phenol desorption is the rate-determining step of EHDC on the catalyst. The support TiN enables alleviation of the phenol poisoning by modulating the electronic structure of Pd. The d band center of Pd can serve as a potential descriptor of EHDC efficiency, and its optimization for balancing 2,4-DCP and phenol adsorption should be an effective strategy to enhance EHDC.

13.
J Hazard Mater ; 367: 658-667, 2019 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-30654283

RESUMEN

We exploit a novel role of MgAl-layered double oxide (LDO) as a powerful sweeper to remove trace emulsified water and organic acids from contaminated oil. Notably, 0.4 g of LDO enable to purify 20 mL of contaminated oil with 0.2 g of water and 0.1 mL of octanoic acid, and the separation efficiency reaches 94.6 and 28.2%, respectively. The separation process is initiated with the immobilization of water droplets at the crystalline matrix of LDO (driven by the unique water memory effect), accompanied by the LDO converted to MgAl-layered double hydroxide (LDH). LDH possesses a high point of zero charge and abundant OH- and Mg2+/Al3+ on its layered surface, which enables it to remove the acids via neutralization and complexing reactions. The immobilized water and adsorbed acids are eventually swept by collecting the solids. The collected solids, mainly composed of LDH, can be regenerated to LDO for recycle through a calcination process. Economy evaluation reveals it takes $6.7 for LDO to purify every cubic meters of emulsion, much more cost-effective than the reported CaSO4•0.5H2O and Fe3O4-based adsorbents. The robust performance with the competitive economy points to the high potential of LDO for oil regeneration.

14.
J Colloid Interface Sci ; 506: 633-643, 2017 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-28763767

RESUMEN

Zero-valent iron nanoparticles (Fe0 NPs) technologies are often challenged by poor dispersibility, chemical instability to oxidation, and mobility during processing, storage and use. This work reports a facile approach to synthesize Fe0 NPs embedded reduced graphene oxide-alginate beads (Fe@GA beads) via the immobilization of pre-synthesized Fe0 NPs into graphene oxide modified alginate gel followed by a modelling and in-situ reduction process. The structure/composition characterization of the beads finds that the graphene sheets and the Fe0 NPs (a shape of ellipsoid and a size of <100nm) are uniformly dispersed within the alginate beads. We demonstrate that these Fe@GA beads show a robust performance in aqueous Cr(VI) removal. With a optimized Fe and alginate content, Fe@GA bead can achieve a high Cr(VI) removal efficiency and an excellent mechanical strength. The initial Cr(VI) concentration, ionic strength, temperature and especially solution pH are all critical factors to control the Fe@GA beads performance in Cr(VI) removal. Fitness of the pseudo second-order adsorption model with data suggests adsorption is the rate-controlling step, and both Langmuir and Freundlich adsorption isotherm are suitable to describe the removal behavior. The possible Cr(VI) removal path by Fe@GA beads is put forward, and the synergistic effect in this ternary system implies the potentials of Fe@GA beads in pollutant removal from water body.

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