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1.
Environ Sci Pollut Res Int ; 27(25): 31543-31554, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32495202

RESUMO

In this study, we evaluated the possible effects of sequenced pulsed magnetic fields (PMF) of 1-mT treatments with designed different frequencies (PMF-1-1, 3, 5, 7 Hz or PMF-2-7, 9, 12, 14 Hz) on the inflammatory signs such as abnormal pain behaviors, hyperalgesia and allodynia, edema, and fever in carrageenan (CG)-induced hind paw inflammation model in rats. Paw tissues were also histologically examined. PMF exposure was applied 3 times in 24 h. CG injection gradually decreased the thermal latencies and mechanical threshold and caused significant increases in temperature and mass of paw. PMF treatments significantly reduced the temperature and mass in the paw of rats with inflammation. PMF-1 treatments caused significant increases in the latencies and thresholds. However, administration of PMF-2 treatment was significantly decreased the latency and threshold. Furthermore, the histological pieces of evidence also suggested the anti-inflammatory effects of PMF-1 treatments or inflammatory actions of PMF-2 treatments. Findings presented in this paper suggest that 1-mT PMF treatments may have anti-edematous and antipyretics activities in inflamed rats. However, the effects of PMF treatments on abnormal pain hypersensitivities may be different. PMF treatments may make inflammatory pain relief or worse in inflamed rats depending on the PMF frequencies in sequence.


Assuntos
Hiperalgesia , Inflamação/tratamento farmacológico , Animais , Anti-Inflamatórios , Edema , Campos Magnéticos , Ratos , Ratos Wistar
2.
Water Sci Technol ; 81(3): 622-629, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32385215

RESUMO

The effect of the magnetic field on denitrification process in immobilized bacteria particles was investigated in this study. The magnetic field could enhance the denitrification efficiency, especially for wastewater with low C/N ratios, and the average removal efficiencies of NO3--N increased by 6.58%. High-throughput sequencing analysis revealed that the magnetic field had substantial impacts on the stability of microbial community structure and relative abundance in immobilized bacteria particles, which was beneficial for the stability of denitrifying bacteria. Through the research in this paper, we suggest that magnetic field can be used to improve the denitrification performance of immobilized bacteria particles in the wastewater treatment industry.


Assuntos
Reatores Biológicos , Desnitrificação , Bactérias , Campos Magnéticos , Nitrogênio , Águas Residuárias
3.
Bioresour Technol ; 310: 123450, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32388352

RESUMO

Enhancing anaerobic digestion performance is highly desired for its large-scale application. In the present work, magnetic fields (0-30 mT) and Ti-sphere core-shell structured additives (Ti-1 and Ti-2) are simultaneously introduced in anaerobic mono-digestion and co-digestions. Compared with the control group, the Ti-sphere core-shell structured additives increase the biogas yield by 27.12%-65.53% for mono-digestion and 8.47%-35.89% for co-digestion systems under the optimized magnetic field intensity (5 mT), respectively. Meanwhile, the degradation rate of total chemical oxygen demand is 54.68%-69.14% for anaerobic mono-digestion and 53.03%-78.25% for anaerobic co-digestion with Ti-sphere core-shell structured additives, respectively. The digestate with Ti-sphere core-shell structured additives exhibits the remarkable stability (45.24%-53.17%) and fertility (4.85%-4.97%). This work clarifies the effect of magnetic field in AD system, and proposes a possible mechanism for understanding the enhanced methanogenesis pathways induced by Ti-sphere core-shell structured additives.


Assuntos
Reatores Biológicos , Esterco , Anaerobiose , Biocombustíveis , Campos Magnéticos , Metano
4.
PLoS One ; 15(4): e0231213, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32271819

RESUMO

Limited data is available concerning the safety of active middle ear implants (AMEI) during Magnetic Resonance Imaging (MRI). Measurements in temporal bones are the gold standard for preclinical assessment of device safety. In this study the coupling stability of an actuator as used in a fully implantable AMEI was determined in temporal bones. Eleven temporal bones were implanted with the actuator according to the manufacturer's surgical guidelines. The actuator was coupled on the incus short process as recommended for sensorineural hearing loss. Temporal bones were exposed 10 times to the MRI magnetic field by entering the MRI suite in a clinically relevant way. Computed Tomography (CT) images were acquired before and after the experiment to investigate the risk of actuator dislocation. Based on the electrical impedance of the actuator, the loading of the actuator to the incus was confirmed. Relative actuator displacement was determined on the CT images by comparing the initial with the final actuator position in 3D space. Impedance curves were analyzed after each exposure to check the loading of the actuator to the ossicles. Analysis of CT images with a 0.30.6 mm in-plane resolution indicate no actuator displacement. The maximum detected change in impedance for all actuators was 8.43 Ω at the actuator's resonance frequency. Impedance curves measured when the actuator was retracted from the short process after the experiment still indicate the presence of a clear resonance peak. No actuator displacement or dislocation could be detected in the analysis of CT images and the measured impedance curves. Impedance curves obtained when the actuator was retracted from the incus short process still show a clear resonance peak, indicating the device is still functional after the MRI exposures.


Assuntos
Bigorna/diagnóstico por imagem , Imagem por Ressonância Magnética , Prótese Ossicular , Impedância Elétrica , Humanos , Campos Magnéticos , Osso Temporal/cirurgia , Tomografia Computadorizada por Raios X
5.
PLoS One ; 15(4): e0232136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330188

RESUMO

Determining the East-West position was a classical problem in human sea navigation until accurate clocks were manufactured and sailors were able to measure the difference between local time and a fixed reference to determine longitude. Experienced night-migratory songbirds can correct for East-West physical and virtual magnetic displacements to unknown locations. Migratory birds do not appear to possess a time-different clock sense; therefore, they must solve the longitude problem in a different way. We showed earlier that experienced adult (but not juvenile) Eurasian reed warblers (Acrocephalus scirpaceus) can use magnetic declination (the difference in direction between geographic and magnetic North) to solve this problem when they were virtually displaced from Rybachy on the eastern Baltic coast to Scotland. In this study, we aimed to test how general this effect was. Adult and juvenile European robins (Erithacus rubecula) and adult garden warblers (Sylvia borin) under the same experimental conditions did not respond to this virtual magnetic displacement, suggesting significant variation in how navigational maps are organised in different songbird migrants.


Assuntos
Migração Animal/fisiologia , Aves Canoras/fisiologia , Navegação Espacial/fisiologia , Animais , Campos Magnéticos , Magnetismo , Orientação , Passeriformes/fisiologia , Fenômenos Físicos , Escócia
6.
Anticancer Res ; 40(4): 1809-1815, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32234869

RESUMO

BACKGROUND/AIM: Wire-guided localisation (WGL) remains the most widely used technique for the localisation of non-palpable breast lesions; however, recent technological advances have resulted in non-wire, non-radioactive alternatives, such as magnetic seeds (Magseeds). The aim of this pooled analysis was to determine whether Magseeds are an effective tool for localising non-palpable breast lesions. MATERIALS AND METHODS: Various databases were searched for publications which reported data on the localisation and placement rates of Magseed. Data on re-excision rates under use of Magseed and WGL were also collected. RESULTS: Sixteen studies, spanning the insertion of 1,559 Magseeds, were analysed. The pooled analysis showed a successful placement rate of 94.42% and a successful localisation rate of 99.86%. Four studies were analysed in a separate pooled analysis and showed no statistically significant difference between re-excision rates using Magseeds and WGL. CONCLUSION: The use of Magseeds is an effective, non-inferior alternative to WGL that overcomes many of the limitations of the latter.


Assuntos
Neoplasias da Mama/terapia , Mama/efeitos da radiação , Terapia de Campo Magnético , Campos Magnéticos , Mama/patologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Feminino , Humanos , Magnetismo , Mastectomia Segmentar
7.
Phys Rev Lett ; 124(12): 128101, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32281830

RESUMO

The discovery of magnetic protein provides a new understanding of a biocompass at the molecular level. However, the mechanism by which magnetic protein enables a biocompass is still under debate, mainly because of the absence of permanent magnetism in the magnetic protein at room temperature. Here, based on a widely accepted radical pair model of a biocompass, we propose a microscopic mechanism that allows the biocompass to operate without a finite magnetization of the magnetic protein in a biological environment. With the structure of the magnetic protein, we show that the magnetic fluctuation, rather than the permanent magnetism, of the magnetic protein can enable geomagnetic field sensing. An analysis of the quantum dynamics of our microscopic model reveals the necessary conditions for optimal sensitivity. Our work clarifies the mechanism by which magnetic protein enables a biocompass.


Assuntos
Campos Magnéticos , Modelos Teóricos , Animais , Biofísica , Aves , Proteínas com Ferro-Enxofre/química , Proteínas com Ferro-Enxofre/fisiologia , Navegação Espacial
8.
Bioresour Technol ; 309: 123299, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32289656

RESUMO

Two anoxic/oxic (A/O) sequencing batch reactor (SBR) processes were utilized to study the effects of static magnetic field (SMF) on biological wastewater treatment process. Except for conventional indices, the reduced nicotinamide adenine dinucleotide (NADH)/oxidized nicotinamide adenine dinucleotide (NAD+) ratio and electron transport system activity (ETSA), as well as poly-beta-hydroxybutyrate (PHB) and extracellular polymetric substance (EPS) contents in two reactors which were with and without SMF under two cyclic times (12 h and 8 h) were monitored. When the process was enhanced by SMF, the total nitrogen removal efficiency can be improved (>80%), and the NADN/NAD+ ratio, ESTA, the maximum EPS content and the maximum PHB content in the reactor with SMF were higher. Besides, SMF can reduce the microorganism community diversity and make species distribute more even and abundant. SMF can promote the performance of A/O SBR process via improving electron transport and microbial community.


Assuntos
Reatores Biológicos , Eliminação de Resíduos Líquidos , Campos Magnéticos , Nitrogênio , Esgotos , Águas Residuárias
9.
Mutat Res ; 850-851: 503150, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32247559

RESUMO

Extremely low frequency electromagnetic fields have been classified as a possible human carcinogen by the International Agency for Research on Cancer and this has raised some concern about its health effects on employees extensively exposed to these fields at thermal power plants. In this study, the effect of using vitamin E and C supplements have been examined on employees working at a thermal power plant. In this randomized controlled, double-blind clinical trial, 81 employees from different parts of the thermal power plant were enrolled between July and November 2017, and divided into four groups: Group 1 received vitamin E (400 units/day), Group 2: vitamin C (1000 mg/day), Group 3: vitamin E + C and Group 4: no intervention. DNA damage was measured in peripheral blood lymphocytes using comet assay and apoptosis, using flow cytometry. Based on the results, tail intensity and tail length in the vitamin E group, and all comet assay indices in the vitamin E + C and vitamin C groups (except DNA damage index) significantly decreased after the intervention, while the comet assay indices did not change significantly in the control group. None of the flow cytometry indices including early apoptosis, late apoptosis and necrosis changed after intervention in either group. The use of antioxidant vitamins such as E and C, can increase the activity of the non-enzymatic antioxidant defense system, and protect DNA from damage caused by exposure to extremely low frequency magnetic fields. But, taking these vitamins has no effect on apoptosis. It seems that consumption of vitamin E affected all investigated comet assay indices and can be probably considered as the best intervention.


Assuntos
Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Vitamina E/administração & dosagem , Adulto , Apoptose/efeitos dos fármacos , Dano ao DNA/genética , Método Duplo-Cego , Citometria de Fluxo , Humanos , Irã (Geográfico) , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Campos Magnéticos/efeitos adversos , Masculino , Centrais Elétricas
10.
J Environ Sci (China) ; 91: 151-159, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32172963

RESUMO

Two chromium removal experiments were performed in bioreactors with and without a magnetic field under the same conditions. The release of the chromium present in the biomass was tested in two experiments one with the initial pH of the medium and one with pH 4.0. The objective was to remove Cr(VI) and total Cr from the effluent, this was carried out by placing biological treatments of synthetic effluent contaminated with 100 mg/L of Cr(VI) in a bioreactor with neodymium magnets that applied a magnetic field (intensity 85.4 mT) to the mixed culture. The removal of Cr(VI) was approximately 100.0% for the bioreactor with a magnetic field and 93.3% for the bioreactor without a magnetic field for 9 hr of recirculation of the synthetic effluent by the bioreactor. The removal of total Cr was 61.6% and 48.4%, with and without a magnetic field, respectively, for 24 hr. The desorption of Cr(VI) in the synthetic effluent was 0.05 mg/L, which is below the limit established by Brazilian legislation (0.1 mg/L) for the discharge of effluent containing Cr(VI) into bodies of water. The results obtained for the removal of chromium in synthetic effluent suggested that there was no significant influence on the viable cell count of the mixed culture. The desorption of Cr(VI) in synthetic effluent after bioadsorption of chromium by the mixed culture in the process of removal of chromium in bioreactors with and without a magnetic field was not significant in either of the experiments with different initial pHs.


Assuntos
Cromo/análise , Poluentes Químicos da Água/análise , Biomassa , Reatores Biológicos , Brasil , Campos Magnéticos
11.
PLoS One ; 15(3): e0229142, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32134934

RESUMO

Migratory birds can detect the direction of the Earth's magnetic field using the magnetic compass sense. However, the sensory basis of the magnetic compass still remains a puzzle. A large body of indirect evidence suggests that magnetic compass in birds is localized in the retina. To confirm this point, an evidence of visual signals modulation by magnetic field (MF) should be obtained. In a previous study we showed that MF inclination impacts the amplitude of ex vivo electroretinogram (ERG) recorded from isolated pigeon retina. Here we present the results of an analysis of putative MF effect on one component of ERG, the photoreceptor's response, isolated from the total ERG by adding sodium aspartate and barium chloride to the perfusion solution. Photoresponses were recorded from isolated retinae of domestic pigeons Columba livia. The retinal samples were placed in MF that was modulated by three pairs of orthogonal Helmholtz coils. Light stimuli (blue and red) were applied under two inclinations of MF, 0° and 90°. In all the experiments, preparations from two parts of retina were used, red field (with dominant red-sensitive cones) and yellow field (with relatively uniform distribution of cone color types). In contrast to the whole retinal ERG, we did not observe any effect of MF inclination on either amplitude or kinetics of pharmacologically isolated photoreceptor responses to blue or red half-saturating flashes. A possible explanations of these results could be that magnetic compass sense is localized in retinal cells other than photoreceptors, or that photoreceptors do participate in magnetoreception, but require some processing of compass information in other retinal layers, so that only whole retina signal can reflect the response to changing MF.


Assuntos
Migração Animal/fisiologia , Columbidae/anatomia & histologia , Campos Magnéticos , Orientação Espacial/fisiologia , Células Fotorreceptoras de Vertebrados/fisiologia , Retina/anatomia & histologia , Resposta Táctica/fisiologia , Animais , Cor , Eletrorretinografia/veterinária , Fundo de Olho , Luz , Magnetismo , Estimulação Luminosa , Células Fotorreceptoras de Vertebrados/citologia , Retina/citologia , Retina/diagnóstico por imagem , Células Fotorreceptoras Retinianas Cones/citologia , Células Fotorreceptoras Retinianas Cones/fisiologia
12.
Int J Nanomedicine ; 15: 1321-1333, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32161461

RESUMO

Introduction: Currently, the unsatisfactory treatment of cardiac hypertrophy is due to the unbridled myocardial fibrosis. Melatonin has been demonstrated to ameliorate cardiac hypertrophy and its accompanied fibrosis in previous studies. But it is not clinically appealing due to its short-lasting time against the hostile microenvironment when administered orally. Methods: Herein, to address this, poly (lactide) polycarboxybetaine (PLGA-COOH) accompanied by cardiac homing peptide (CHP) and superparamagnetic iron oxide nanoparticles (SPIONs) were used to establish a novel drug delivery and transportation strategy for melatonin via a facile two-step emulsion method. This study characterized these nanoparticles (CHP-mel@SPIONs) and tested their delivery to the hypertrophied heart and their effect on myocardial hypertrophy and fibrosis in an animal model of pressure overload-induced cardiac hypertrophy. Results: The engineered magnetic nanoparticles of CHP-mel@SPIONs were spherical (diameter = 221 ± 13 nm) and had a negative zeta potential of -19.18 ± 3.27 mV. The CHP-mel@SPIONs displayed excellent drug encapsulation capacities of SPIONs (75.27 ± 3.1%) and melatonin (77.69 ± 6.04%) separately, and their magnetic properties were characterized by constructing magnetic hysteresis curves and exhibited no remnant magnetization or coercivity. The animal experiments showed that compared with mel@SPIONs, CHP-mel@SPIONs accumulated more in the heart, especially in the presence of an external magnetic field, with in vivo echocardiography and RT-PCR and histological assessments confirming the amelioration of the myocardial hypertrophy and fibrosis with low drug doses. Conclusion: This simple biocompatible dual-targeting nanoagent may be a potential candidate for the guided clinical therapy of heart disease.


Assuntos
Cardiomegalia/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas de Magnetita/química , Melatonina/administração & dosagem , Miocárdio/patologia , Animais , Cardiomegalia/patologia , Modelos Animais de Doenças , Óxido Ferroso-Férrico/química , Fibrose , Coração/efeitos dos fármacos , Campos Magnéticos , Melatonina/farmacologia , Nanoestruturas , Peptídeos/química , Pressão , Ratos Sprague-Dawley
13.
Ecotoxicol Environ Saf ; 194: 110407, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32146198

RESUMO

Extremely low-frequency electromagnetic fields (ELF-EMFs) present a kind of common non-ionizing radiation in public and occupational environments. Previous studies have suggested that ELF-EMF exposure might have a potential impact on co-carcinogenesis and the progression of tumorigenesis by inducing cell proliferation. However, the underlying mechanisms remain largely unknown. In this study, we investigated the possible role of the sphingosine-1-phosphate (S1P)-related pathway in regulating cell proliferation induced by 50-Hz, 0.4-mT magnetic-field (MF) exposure. The results showed that MF exposure significantly promoted sphingosine kinase 1 (SphK1) activity, and that inhibition of the SphK1-S1P-S1P receptor (S1PR) pathway could remarkably reverse MF-induced cell proliferation. Additionally, we could infer indirectly from an exogenous-S1P experiment that MF-induced S1P might act on S1PR1/3 in a paracrine and/or autocrine manner to mediate the proliferation effect. Notably, although the MF activated the extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) pathways, the SphK1-S1P-S1PR1/3 cascade regulated MF-induced proliferation by activating the ERK rather than the Akt pathway. Taken together, the findings of this study indicated that the SphK1-S1P-S1PR1/3 cascade played an important role in MF-induced proliferation by mediating the ERK signaling pathway, which could bring new insights into understanding and preventing the adverse effects of MFs.


Assuntos
Âmnio , Células Epiteliais/metabolismo , Lisofosfolipídeos/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Campos Magnéticos/efeitos adversos , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Esfingosina/análogos & derivados , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Epiteliais/patologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Esfingosina/metabolismo , Receptores de Esfingosina-1-Fosfato/metabolismo
15.
Ecotoxicol Environ Saf ; 193: 110350, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114242

RESUMO

Epidemiological studies have shown associations between exposure to environmental extremely low frequency magnetic fields (ELF-MF) and health effects, but the mechanisms of ELF-MF induced biological effects remain unclear. We hypothesized that ELF-MF may regulate functions of tissues or cells via its effects on surrounding environment, e.g., culture medium. To test this hypothesis, we investigated the effects of 50 Hz MF on the relative permittivity of zebrafish embryos culture medium as well as of MF-exposed medium on zebrafish embryos development. The responses of medium to 50 Hz MF exposure were evaluated by a phase-sensitive surface plasmon resonance (SPR) system. The results demonstrated that MF treatment decreased relative permittivity of zebrafish embryos medium in a dose and time-dependent way. Interestingly, the decreased permittivity induced by MF exposure gradually recovered and approached to the base level when the exposure was removed off. However, MF-exposed medium did not trigger adverse consequences of embryos during zebrafish embryonic development, including mortality, malformation, hatching and heart rate when the MF pre-exposed medium was subjected to one cell-stage embryos. Moreover, the MF-exposed medium did not induce apoptosis of zebrafish embryos at 48 and 72 h post fertilization. Our data demonstrated that the relative permittivity of zebrafish embryos medium was decreased by MF exposure, whereas this decrease failed to result in abnormal development of zebrafish embryos.


Assuntos
Desenvolvimento Embrionário , Campos Magnéticos/efeitos adversos , Animais , Apoptose , Meios de Cultura , Peixe-Zebra/embriologia
16.
Water Environ Res ; 92(8): 1131-1141, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32056340

RESUMO

Photosynthetic bacteria (PSB) technology is a promising method for biomass, protein, pigments, and other value-added substances generation from wastewater. However, the above bioresources production efficiency is relatively low. In this work, a static magnetic field (SMF) was used to promote bioresources production. Results showed that SMF had positive effects on value-added substances production. With 0.35 Tesla (T) SMF, the PSB biomass, protein, carotenoids, and bacteriochlorophyll concentration were promoted by 31.1%, 22.6%, 56.7%, and 73.1% compared with the control group, respectively. Biomass yield finally reached 0.58 g biomass/g COD removal, which was promoted by 37.1%. The doubling time was shortened by 37.9% in 0.35 T group, showing that SMF can promote cell growth. With 0.35 T SMF, the intracellular NADH dehydrogenase and ATP synthase activities concentration increased by 23.4% and 29.1%, respectively, thus increased the ATP content by 38.0%. Succinic dehydrogenase activity concentration greatly increased by 609.0% at 48 hr, which potentially accelerated the tricarboxylic acid cycle and COD degradation as well as enhanced biomass production. PRACTITIONER POINTS: SMF promoted PSB bioresource production during wastewater treatment processing. Biomass, protein, carotenoids, and Bchl concentration were promoted by 31.1%, 22.6%, 56.7%, and 73.1%, respectively. PSB yield of 0.35 T group was promoted by 37.1% compared with the control group. SDH concentration of 0.35 T was promoted by 609.0% compared with the control group. Increased NADH and ATP synthase activity concentration by SMF enhanced energy metabolism.


Assuntos
Águas Residuárias , Purificação da Água , Bactérias , Campos Magnéticos , Fotossíntese
17.
Chemosphere ; 248: 126112, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32069698

RESUMO

Coal fly ash (CFA) is one of the most promising secondary sources of rare earth elements and yttrium (REY). This research first studied the modes of occurrence of REY in CFA collected from a China's power generation plant which utilizes a coal feedstock with an elevated REY content. The fact that rare earth minerals remain in CFA and REY associate with metal oxides was proved by emission-scanning electron microscope with an energy-dispersive X-ray spectrometer. The technical feasibility of recovery of REY from CFA was then studied through conducting various physical separation methods followed by acid leaching. It was found that REY are concentrated in fine particle size, non-magnetic and middle density fractions. Using combined physical separation processes, the REY of CFA was enriched from 782 µg·g-1to 1025 µg g-1. The acid leaching process was optimized for various parameters via the Taguchi three-level experimental design. Upon optimization, the physical separation product was leached at the optimum condition and 79.85% leaching efficiency was obtained. Based on the obtained results, a conceptual process flowsheet was developed for recovery of REY from CFA. Such recovery maximizes REY resources utilization and enhances sustainability of CFA disposal.


Assuntos
Cinza de Carvão/química , Metais Terras Raras/análise , Minerais/química , Centrais Elétricas , Eliminação de Resíduos/métodos , Ácidos/análise , Fracionamento Químico , China , Campos Magnéticos , Solubilidade , Ítrio/análise
18.
Int J Nanomedicine ; 15: 315-332, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32021182

RESUMO

Purpose: The clinical outcome of spinal cord injury is usually poor due to the lack of axonal regeneration and glia scar formation. As one of the most classical supporting cells in neural regeneration, Schwann cells (SCs) provide bioactive substrates for axonal migration and release molecules that regulate axonal growth. However, the effect of SC transplantation is limited by their poor migration capacity in the astrocyte-rich central nervous system. Methods: In this study, we first magnetofected SCs with chondroitinase ABC-polyethylenimine functionalized superparamagnetic iron oxide nanoparticles (ChABC/PEI-SPIONs) to induce overexpression of ChABC for the removal of chondroitin sulfate proteoglycans. These are inhibitory factors and forming a dense scar that acts as a barrier to the regenerating axons. In vitro, we observed the migration of SCs in the region of astrocytes after the application of a stable external magnetic field. Results: We found that magnetofection with ChABC/PEI-SPIONs significantly up-regulated the expression of ChABC in SCs. Under the driven effect of the directional magnetic field (MF), the migration of magnetofected SCs was enhanced in the direction of the magnetic force. The number of SCs with ChABC/PEI-SPIONs migrated and the distance of migration into the astrocyte region was significantly increased. The number of SCs with ChABC/PEI-SPIONs that migrated into the astrocyte region was 11.6- and 4.6-fold higher than those observed for the intact control and non-MF groups, respectively. Furthermore, it was found that SCs with ChABC/PEI-SPIONs were in close contact with astrocytes and no longer formed boundaries in the presence of MF. Conclusion: The mobility of the SCs with ChABC/PEI-SPIONs was enhanced along the axis of MF, holding the potential to promote nerve regeneration by providing a bioactive microenvironment and relieving glial obstruction to axonal regeneration in the treatment of spinal cord injury.


Assuntos
Astrócitos/fisiologia , Condroitina ABC Liase/metabolismo , Nanopartículas de Magnetita/uso terapêutico , Regeneração Nervosa/fisiologia , Células de Schwann/fisiologia , Animais , Astrócitos/citologia , Axônios/efeitos dos fármacos , Movimento Celular , Células Cultivadas , Condroitina ABC Liase/genética , Condroitina ABC Liase/farmacologia , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Feminino , Campos Magnéticos , Nanopartículas de Magnetita/química , Masculino , Regeneração Nervosa/efeitos dos fármacos , Polietilenoimina/química , Ratos , Ratos Sprague-Dawley , Células de Schwann/citologia , Traumatismos da Medula Espinal/terapia
19.
Chemosphere ; 249: 126057, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062204

RESUMO

A non-uniform magnetic field was applied to sequester Cr(VI) with microscale zero-valent iron (ZVI). When the non-uniform magnetic field was applied, the average removal rate of Cr(VI) was increased and the lag phase was shortened with the increasing of magnetic field intensity. The instantaneous rate was fast at the beginning and about 40% of the Cr(VI) was sequestered rapidly when ZVI was added into the magnetic field system. Later, the sequestration rate of Cr(VI) was reduced and remained stable with time until Cr(VI) was removed completely. The instantaneous removal rate was positively correlated with ZVI dosage and the rate per unit mass of ZVI was 0.455 mg/(L·min·gZVI). The constant rate stage was not affected by the initial and the residual concentration of Cr(VI). In the case where no magnetic field was applied, the removal of Cr(VI) is a process in which ZVI is depassivated and its reactivity is restored continuously. The promotion of a magnetic field on the removal of Cr(VI) is mainly due to increasing the role of adsorbed reducing species of Fe2+ or Fe0 on the ZVI surface. Aging of ZVI under a magnetic field could enhance the release rate of Fe2+ in the initial 5 min though the remanence of this kind of ZVI had little effect on the enhancement of the sequestration of Cr(VI).


Assuntos
Cromo/química , Poluentes Químicos da Água/química , Adsorção , Ferro , Campos Magnéticos
20.
Bioresour Technol ; 303: 122884, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32035387

RESUMO

This paper investigated the effects of temperature and cultivation methods (batch or semi-continuous culture) on the filamentous microalgae Tribonema sp. biomass production and nutrients removal in starch wastewater under low intensity magnetic field (MF) intervention. The MF significantly promoted algal growth in the late logarithmic-phase of batch cultivation, and the effect was even more obvious at lower temperatures. The MF treated group at 30 °C accumulated the highest biomass of 4.44 g/L of batch culture, an increase of 15.0% compared with the control group. The oil content of Tribonema sp. was enhanced with the MF intervention, especially for the batch culture. In the semi-continuous culture under MF intervention, Tribonema sp. reached the high biomass of 18.45 g/L after 25 days. When gradually reducing hydraulic retention time (HRT) to 1 day, the average removal rates for COD, TN, NH3-N and TP were all more than 90% in the semi-continuous cultivation.


Assuntos
Microalgas , Biomassa , Campos Magnéticos , Nutrientes , Amido , Temperatura , Águas Residuárias
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