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1.
Water Res ; 188: 116498, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33080455

RESUMO

Complete biological denitrification is usually restricted in electron donor lacking waters. Hydrogenotrophic denitrification attracts attention for its clean and cost-efficiency advantages. Therein, the hydrogen could be effectively generated by microbial electrolysis cells (MECs) from organic wastes. In this study, a gas diffusion membrane (GDM) integrated MEC (MMEC) was constructed and provided a novel non-polluting approach for nitrate contaminated water remediation, in which the hydrogen was recovered from substrate degradation in anode and diffused across GDM as electron donor for denitrification. The high overall nitrogen removal of 91 ± 0.1%-95 ± 1.9% and 90 ± 1.6%-94 ± 2.2% were respectively achieved in Ti-MMEC and SS-MMEC with titanium and stainless-steel mesh as cathode at all applied voltages (0.4-0.8 V). Decreasing applied voltage from 0.8 to 0.4 V significantly improved the electron utilization efficiency for denitrification from 26 ± 3.6% to 73 ± 0.1% in Ti-MMEC. Integrating MEC with GDM greatly improved TN removal by 40% under applied voltage of 0.8 V. The hydrogenotrophic denitrifiers of Rhodocyclaceae, Paracoccus, and Dethiobacter, dominated in MMECs facilitating TN removal. Functional denitrification related genes including napAB, nirKS, norBC and nosZ predicted by PICRUSt2 based on 16S rRNA gene data demonstrated higher abundance in MMECs.


Assuntos
Desnitrificação , Nitratos , Biofilmes , Reatores Biológicos , Eletrólise , Membranas , Nitrogênio , RNA Ribossômico 16S
2.
Sci Total Environ ; 753: 142021, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32898810

RESUMO

Membrane filtration electrode based microbial fuel cell provides a promising route to simultaneously recover energy and produce high-quality effluent during water treatment. Enhancing effluent quality and oxygen reduction reaction (ORR) activity of the membrane electrode still remains a major challenge. In this study, filtration types of membrane electrodes with Prussian blue (PB) doping and PVDF-PVC-PEG triblock copolymers were prepared by a simple phase inversion fabrication process. The PB-0.2 membrane electrode with optimal 0.2 wt% of PB obtained the highest current density (12.0 A m-2) and the lowest charge transfer resistance (5.0 ± 0.1 Ω). Rotating disk electrode (RDE) results also demonstrated that the PB-0.2 catalyst exhibited the superior ORR activity with the highest number of transferred electrons (n = 3.90). Furthermore, the MFC with PB-0.2 produced the maximum power density of 1401 ± 17 mW m-2, which was 186.5% higher than that of the control. Moreover, the filtrated effluent tCODeff was 20.6 ± 1.2 mg L-1 for the PB-0.2, which was significantly reduced by 63% compared with the control. These results showed that the addition of PB was an effective strategy to enhance the overall oxygen reduction performance and improve effluent quality of microbial fuel cells.


Assuntos
Fontes de Energia Bioelétrica , Eletrodos , Ferrocianetos , Oxigênio
3.
Sci Total Environ ; 755(Pt 2): 142641, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33049541

RESUMO

The microbial electrochemical system (MES) has great advantages in wastewater treatment for rapid chemical oxygen demand (COD) removal and low sludge yield rate. Herein, biocathode MES was proposed to remove COD from high-ammonia wastewater with low carbon­nitrogen ratio and regulate the nitrogen forms in effluent for ANAMMOX process. The biocathode was more sensitive to ammonia nitrogen (NH4+-N) than anode and determined the power generation of MES. With COD of 500-550 mg L-1 in influent, increasing NH4+-N from 50 to 150 mg L-1 improved maximum power output (Pmax) from 3.0 ± 0.2 to 3.4 ± 0.1 W m-3, which was then reduced with further increase of NH4+-N from 300 to 600 mg L-1. However, for the cathodic reductive current, the negative effects of ammonia only revealed with NH4+-N ≥ 450 mg L-1. The cathodic equilibrium potential drop determined the power degradation, because the increased reductive compounds (NH4+ and COD) in catholyte. The high NH4+-N reduced the abundance of denitrifiers, exoelectrogens and organic-degrading bacteria on electrodes, while that of nitrogen-fixing bacteria increased. External alkalinity addition achieved in-situ short-cut nitrification and nitrite accumulation. With comparable NH4+ and NO2-, limited NO3- and low COD, the biocathode MES effluent was then suitable for subsequence ANAMMOX process.

4.
Neural Netw ; 132: 108-120, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32866745

RESUMO

Neuromorphic data, recording frameless spike events, have attracted considerable attention for the spatiotemporal information components and the event-driven processing fashion. Spiking neural networks (SNNs) represent a family of event-driven models with spatiotemporal dynamics for neuromorphic computing, which are widely benchmarked on neuromorphic data. Interestingly, researchers in the machine learning community can argue that recurrent (artificial) neural networks (RNNs) also have the capability to extract spatiotemporal features although they are not event-driven. Thus, the question of "what will happen if we benchmark these two kinds of models together on neuromorphic data" comes out but remains unclear. In this work, we make a systematic study to compare SNNs and RNNs on neuromorphic data, taking the vision datasets as a case study. First, we identify the similarities and differences between SNNs and RNNs (including the vanilla RNNs and LSTM) from the modeling and learning perspectives. To improve comparability and fairness, we unify the supervised learning algorithm based on backpropagation through time (BPTT), the loss function exploiting the outputs at all timesteps, the network structure with stacked fully-connected or convolutional layers, and the hyper-parameters during training. Especially, given the mainstream loss function used in RNNs, we modify it inspired by the rate coding scheme to approach that of SNNs. Furthermore, we tune the temporal resolution of datasets to test model robustness and generalization. At last, a series of contrast experiments are conducted on two types of neuromorphic datasets: DVS-converted (N-MNIST) and DVS-captured (DVS Gesture). Extensive insights regarding recognition accuracy, feature extraction, temporal resolution and contrast, learning generalization, computational complexity and parameter volume are provided, which are beneficial for the model selection on different workloads and even for the invention of novel neural models in the future.

5.
Lab Chip ; 20(18): 3474, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32812609

RESUMO

Correction for 'On-chip stool liquefaction via acoustofluidics' by Shuaiguo Zhao et al., Lab Chip, 2019, 19, 941-947, DOI: .

6.
Arch Gynecol Obstet ; 302(3): 553-567, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32643040

RESUMO

PURPOSE: To analyze the effect of Chlamydia trachomatis (C. trachomatis) on adverse pregnancy outcomes based on the currently available evidence. METHODS: Multiple databases were comprehensively searched from the available date of inception through December 9, 2019. The effect of C. trachomatis on adverse pregnancy outcomes was assessed using pooled odds rations (ORs) and 95% confidence intervals (CIs). Egger's test was used for publication bias. RESULTS: Fifty studies involving 502,141 participants were identified. C. trachomatis infection was found to be associated with preterm birth in antibody detection [OR (95% CI): 1.571 (1.112-2.220), P = 0.010] and high-quality assessment [OR (95% CI): 1.734 (1.295-2.321), P < 0.001], preterm premature rupture of membranes (PPROM) in culture detection [OR (95% CI): 4.339 (1.806-10.424), P = 0.001] and high-quality assessment [OR (95% CI): 2.822 (1.333-5.973), P = 0.007], stillbirth [OR (95% CI): 1.585 (1.219-2.062), P = 0.001], low-birthweight babies [OR (95% CI): 2.205 (1.137-4.274), P = 0.019], and babies small for gestational age [OR (95% CI): 1.193 (1.091-1.305), P < 0.001]. No publication bias was exhibited in miscarriage (P = 0.170), preterm birth (P = 0.303), PPROM (P = 0.341), stillbirth (P = 0.533), and low-birthweight babies (P = 0.535). CONCLUSIONS: C. trachomatis infection during pregnancy is associated with a higher risk of preterm birth, PPROM, stillbirth, low-birthweight babies, and babies small for gestational age.


Assuntos
Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis/isolamento & purificação , Ruptura Prematura de Membranas Fetais/epidemiologia , Trabalho de Parto Prematuro/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Aborto Espontâneo , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/microbiologia , Feminino , Ruptura Prematura de Membranas Fetais/microbiologia , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/microbiologia , Resultado da Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Natimorto
7.
J Zhejiang Univ Sci B ; 21(6): 485-494, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32478494

RESUMO

Resveratrol (3,5,4'-trihydroxystilbene, RSV) has been widely used in mammalian cells, but whether it can be used during freezing boar semen is still unknown. The effects of RSV treatment during boar semen freezing on its anti-freezing ability, apoptosis, and possible apoptotic pathways were observed in this study. Sperm motility, mitochondrial membrane potential (ΔΨm), adenosine triphosphate (ATP) content, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)-positive apoptotic state, and messenger RNA (mRNA) expression levels of apoptotic genes involved in different apoptotic pathways after freezing with or without RSV treatment were tested. The results showed that: (1) Compared with fresh sperm, the motility, normal acrosome rate, and plasma membrane integrity rate of frozen boar sperm decreased significantly (P<0.05), and RSV did not significantly increase the sperm motility (0.44 vs. 0.40, P>0.05), but it did significantly improve the normal acrosome rate (57.65% vs. 47.00%, P<0.05) and plasma membrane integrity rate (46.67% vs. 38.85%, P<0.05). (2) After freezing, most boar sperm showed low mitochondrial ΔΨm. RSV treatment could increase the rate of high mitochondrial ΔΨm of boar sperm. (3) RSV treatment significantly decreased reactive oxygen species (ROS) levels (58.65% vs. 88.41%, P<0.05) and increased the ATP content (0.49 µmol/L vs. 0.25 µmol/L, P<0.05) of boar sperm during freezing. (4) The apoptotic rate of the freezing group (80.41%) with TUNEL detection increased significantly compared to the fresh group (9.70%, P<0.05), and RSV treatment greatly decreased the apoptotic rate (68.32%, P<0.05). (5) Real-time polymerase chain reaction (RT-PCR) showed that not only the genes from the death receptor-mediated apoptotic pathway (tumor necrosis factor-α (TNF-α), Fas ligand (FasL), and Caspase-8), but also the genes from the mitochondria-mediated apoptotic pathway (manganese superoxide dismutase (MnSOD), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and Caspase-9) were both significantly changed after freezing. RSV treatment during freezing greatly changed their expression levels. Although RSV treatment during boar semen freezing did not significantly increase motility after thawing, it still played an efficient antioxidant role, which could enhance the mitochondrial function and decrease the apoptotic level induced by both the death receptor- and mitochondria-mediated apoptotic pathways.

8.
Bioresour Technol ; 311: 123478, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32446232

RESUMO

The microbial separator (MS) was promising alternative of ion exchange membrane for biocathode microbial electrochemical system (MES). Four microbial separators developed from porous matrixes were equipped in biocathode MESs. The power generation of MESs responded to cross-separator transfer characters of ions, dissolved oxygen (DO) and chemical oxygen demand (COD). The MES with carbon felt (CF) obtained 31% higher maximum power density at 70 ± 3 mW m-2 and 51% higher current density at 271 ± 21 mA m-2 than those of cation exchange membrane (CEM) separator. All MSs showed higher ionic conductivity than CEM. However, the power variation was mainly due to cathodic equilibrium potential changes rather than internal resistance. The power density demonstrated negative correlation with mass transfer coefficients of DO and COD. The cross-separator transfer of COD caused cathode variation and was identified as the primary parameter for further optimization of MES with microbial separators.


Assuntos
Fontes de Energia Bioelétrica , Análise da Demanda Biológica de Oxigênio , Eletrodos , Íons , Oxigênio
10.
Bioresour Technol ; 294: 122236, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610499

RESUMO

A 10-liter single chamber vertical baffle flow biocathode microbial electrochemical system (MES) with microbial separator was designed for wastewater treatment. The anode and cathode compartments were incompletely isolated by the microbial separator, which enabled module integration and centralized sludge collection of MES. The effluent COD was <50 mg L-1 with COD removal of 86 ±â€¯2% and low sludge yield rate of 0.05 ±â€¯0.02 g-sludge g-1 -COD. The MES performance was mainly restricted by biocathodes and supporting matrixes with higher permeability resulted in better cathode performance. The MES obtained the maximum power density of 67.5 ±â€¯7.8 mW m-2 with two layers of filter cloth and one layer of polyurethane sponge (S2P1) and supporting matrix with moderate permeability was more suitable in overall power generation and anode stability. The influences on bio-community of both cathodes and separators by the permeability of supporting matrixes were observed.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Esgotos , Têxteis , Águas Residuárias
11.
Biomed Pharmacother ; 117: 109092, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31203134

RESUMO

BACKGROUND: 17ß-Estradiol (E2) is a critical regulator of trophoblast function during pregnancy. Serum- and glucocorticoid-inducible kinase (SGK1) has been shown to regulate specific cellular targets downstream of E2. However, whether and how SGK1 directly mediates the regulatory effects of E2 on trophoblasts functions remain unknown. METHODS: SGK1 expression in human villous samples and serum E2 levels were measured in women with early pregnancy loss (EPL) and healthy pregnant women. The effect of E2 on SGK1 regulation was assessed using luciferase reporter gene assay and Chromatin Immunoprecipitation assay. The mediation of regulatory effects of E2 by SGK1 on trophoblast functions including cell viability, invasion and related signaling molecules such as B cell leukemia/lymphoma 6, E-cadherin, matrix metalloproteinase 2, α-ENaC, vascular endothelial growth factor, and the phosphorylation status of FOXO1 and AKT were evaluated in HTR8/SVneo cells transfected with SGK1 knockdown plasmid with/without E2 treatment. RESULTS: SGK1 protein levels in human villous samples and serum E2 levels were decreased in patients with EPL compared to controls. E2 (10 nM) increased SGK1 promoter activity directly through estrogen receptor. E2-activated SGK1 enhanced cell viability, invasion and downstream targets in trophoblast cells. SGK1 knockdown abrogated the above responses to E2 treatment. CONCLUSIONS: SGK1 mediates the effects of E2 on trophoblast viability and invasion, suggesting that SGK1 acts as a key node in regulating the cross-talk at the feto-maternal interface during the development of placenta and might be a potential therapeutic target for EPL.


Assuntos
Sobrevivência Celular/fisiologia , Estradiol/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Trofoblastos/metabolismo , Caderinas/metabolismo , Linhagem Celular , Movimento Celular/fisiologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Placenta/metabolismo , Gravidez , Regiões Promotoras Genéticas/fisiologia , Receptores Estrogênicos/metabolismo
12.
Water Res ; 155: 372-380, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30856521

RESUMO

A pilot microbial electrochemical system (MES) system with a total volume of 1.5 m3 was developed and operated outdoor in a municipal wastewater treatment plant (WWTP). Microbial separator based on the dynamic biofilm on low-cost porous matrix was applied to replace ion exchange membranes (IEMs), while the separate plug-in module architecture allowed the totally 336 pairs of MES units and 14 separator modules to be integrated into one wastewater tank. The separator layer equally divided the wastewater tank into 7 cathodic and 8 anodic compartments. Fed with primary sedimentation tank effluent of WWTP, the pilot MES achieved stable removal efficiency for chemical oxygen demand (91 ±â€¯3%), total nitrogen (64 ±â€¯2%) and ammonium nitrogen (91 ±â€¯3%), which were complied with the first grade A standard of pollutants for municipal wastewater treatment plant (DSPMWTP) in China. The stable power output of pilot MES was 406 ±â€¯30 mW m-3 based on effective liquid volume, or energy conversion performance of 2.03 × 10-3 kWh m-3 (one cubic meter of influent wastewater). The pilot MES achieved much lower effluent COD of 25 ±â€¯7 mg L-1 with HRT of 5 h, while that of activated sludge process in WWTP was 43 ±â€¯6 mg L-1 under HRT of 12 h. Even though the aeration of biocathode demanded a net electricity consumption of 3.44 × 10-3 kWh m-3, the low operation energy requirement for pilot MES was only 12% of that in a typical activated sludge process (0.3 kWh m-3). By avoiding the utilization of IEMs and redundant structural materials, the pilot MES achieved a low system cost of $1702.1 (or $1135 m-3) as well and promoted the further real-world application of MES.


Assuntos
Esgotos , Águas Residuárias , Análise da Demanda Biológica de Oxigênio , China , Nitrogênio , Eliminação de Resíduos Líquidos
13.
Lab Chip ; 19(6): 941-947, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30702741

RESUMO

Microfluidic-based portable devices for stool analysis are important for detecting established biomarkers for gastrointestinal disorders and understanding the relationship between gut microbiota imbalances and various health conditions, ranging from digestive disorders to neurodegenerative diseases. However, the challenge of processing stool samples in microfluidic devices hinders the development of a standalone platform. Here, we present the first microfluidic chip that can liquefy stool samples via acoustic streaming. With an acoustic transducer actively generating strong micro-vortex streaming, stool samples and buffers in microchannel can be homogenized at a flow rate up to 30 µL min-1. After homogenization, an array of 100 µm wide micropillars can further purify stool samples by filtering out large debris. A favorable biocompatibility was also demonstrated for our acoustofluidic-based stool liquefaction chip by examining bacteria morphology and viability. Moreover, stool samples with different consistencies were liquefied. Our acoustofluidic chip offers a miniaturized, robust, and biocompatible solution for stool sample preparation in a microfluidic environment and can be potentially integrated with stool analysis units for designing portable stool diagnostics platforms.


Assuntos
Bactérias/isolamento & purificação , Fezes/microbiologia , Microfluídica/métodos , Bactérias/metabolismo , Biomarcadores/metabolismo , Fezes/química , Gastroenteropatias/diagnóstico , Gastroenteropatias/patologia , Humanos , Microscopia de Fluorescência , Miniaturização , Sistemas Automatizados de Assistência Junto ao Leito , Transdutores
14.
Biomicrofluidics ; 13(5): 054109, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31893009

RESUMO

In this study, we proposed a microfluidic device with compact structures integrating multiple modalities for cell capture, pairing, fusion, and culture. The microfluidic device is composed of upper and lower parts. The lower part configured with electrodes and capture wells is used for cell trapping/pairing/fusion, while the upper part configured with corresponding culture wells is used for cell culture. Dielectrophoresis is used to enable accurate cell trapping and pairing in capture wells. Moreover, the paired cells are fused flexibly by either electrical pulses or polyethylene glycol (PEG) buffer. The fused cells are then transferred to culture wells for on-chip culture simply by flipping the device. Using the device and HeLa cells, we demonstrated pairing efficiency of ∼78% and fusion efficiencies of ∼ 26% for electrical fusion or ∼ 21% for PEG fusion, and successful cell proliferation and migration after 72 h on-chip culture. We believe that this multifunction-integrated but structure-simplified microfluidic device would largely facilitate cell fusion oriented tasks.

15.
Electrophoresis ; 40(5): 784-791, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30350868

RESUMO

Cell rotation is widely required in various fields as an important technique for single cell manipulation. Usually, the electro-rotational manipulation of single cells by dielectrophoresis technologies requires at least three electrodes to generate rotating electric fields which induce cells to rotate. Here, we present a novel microfluidic chip capable of rotating single cell using only two planar electrodes by taking polarized cells as the extra electrodes with phase-shifted signal. To demonstrate this idea, we configured two parallel and planar electrodes as basic dielectrophoresis elements and placed trenches above these electrodes to attract cells, which were in turn polarized to be electrodes. Through simulation, we confirmed the functional structure of the device works well to generate proper rotating electric fields for cell rotation. Through experiment, we successfully demonstrated controlled electro-rotation of HeLa and HepaRG cells. The novel electro-rotation mechanism not only simplifies the micro-device structure but also reduces the complexity of single cell rotation operation which will be a benefit to the potential users.


Assuntos
Técnicas Eletroquímicas/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Análise de Célula Única/instrumentação , Eletrodos , Desenho de Equipamento , Células HeLa , Humanos , Rotação
16.
Rev Sci Instrum ; 89(11): 115106, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30501278

RESUMO

The dynamic fragmentation of shock-loaded high-Z metal is of considerable importance for both basic and applied science. The areal density and mass-velocity distribution of dynamic fragmentation are crucial factors in understanding this issue. Experimental methods, such as pulsed X-ray radiography and proton radiography, have been utilized to obtain information on such factors; however, they are restricted to a complex device, and the spatial resolution is in the order of 100 µm. In this work, we present the high-quality radiography of the dynamic fragmentation of laser shock-loaded tin, with good two-dimensional (2D) spatial resolution. Dynamic fragmentation is generated via high-intensity ns-laser shock-loaded tin. A high-energy X-ray source in the 50-200 keV range is realized by the interaction of a high-intensity ps-pulse with an Au microwire target, attached to a low-Z substrate material. A high 2D resolution of 12 µm is achieved by point-projection radiography. The dynamic-fragmentation radiography is clear, and the signal-to-noise ratio is sufficiently high for a single-shot experiment. This unique technique has potential application in high-energy density experiments.

17.
Biosens Bioelectron ; 122: 217-223, 2018 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-30265972

RESUMO

Microbial fuel cells (MFCs) are a promising clean energy source to directly convert waste chemicals to available electric power. However, the practical application of MFCs needs the increased power density, enhanced energy conversion efficiency and reduced electrode material cost. In this study, three-dimensional (3D) macroporous N, P and S co-doped carbon foams (NPS-CFs) were prepared by direct pyrolysis of the commercial bread and employed as free-standing anodes in MFCs. As-obtained NPS-CFs have a large specific surface area (295.07 m2 g-1), high N, P and S doping level, and excellent electrical conductivity. A maximum areal power density of 3134 mW m-2 and current density of 7.56 A m-2 are generated by the MFCs equipped with as-obtained NPS-CF anodes, which is 2.57- and 2.63-fold that of the plain carbon cloth anodes (areal power density of 1218 mW m-2 and current density of 2.87 A m-2), respectively. Such improvement is explored to mainly originate from two respects: the good biocompatibility of NPS-CFs favors the bacterial adhesion and enrichment of electroactive Geobacter species on the electrode surface, while the high conductivity and improved bacteria-electrode interaction efficiently promote the extracellular electron transfer (EET) between the bacteria and the anode. This study provides a low-cost and sustainable way to fabricate high power MFCs for practical applications.


Assuntos
Fontes de Energia Bioelétrica , Pão , Carbono/química , Pirólise , Aderência Bacteriana , Fontes de Energia Bioelétrica/economia , Fontes de Energia Bioelétrica/microbiologia , Pão/análise , Pão/economia , Condutividade Elétrica , Eletricidade , Eletrodos/economia , Geobacter/fisiologia , Nitrogênio/química , Fósforo/química , Porosidade , Enxofre/química
18.
Bioelectrochemistry ; 123: 190-200, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29800809

RESUMO

Nanomaterials for facilitating the microbial extracellular electron transfer (EET) process have drawn increasing attention due to their specific physical, chemical and electrical properties. This review summarizes the research advances of nanomaterials for accelerating the EET process. Nanostructured materials, including oligomer, carbon nanotube (CNT), graphene, metal, metal oxides, and polymer, exhibit numerous admirable properties such as large surface area, high electrical conductivity, and excellent catalytic activity. In this review, depending on the exact site where the nanomaterials work, the nanomaterials are classified into four groups: inside-membrane, interface, inside-biofilm and interspecies. Synthesis of the nanomaterials, EET enhancement performance, and corresponding enhancement mechanisms are also discussed. In spite of the challenges, nanomaterials will be extremely promising for promoting the EET process application in the future.


Assuntos
Bactérias/metabolismo , Técnicas Eletroquímicas/métodos , Transporte de Elétrons , Nanoestruturas/química , Nanotecnologia/métodos , Fenômenos Fisiológicos Bacterianos , Biofilmes , Técnicas Eletroquímicas/instrumentação , Elétrons , Desenho de Equipamento , Nanoestruturas/ultraestrutura
19.
Water Res ; 138: 129-136, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29574200

RESUMO

A migration electric-field assisted electrocoagulation (MEAEC) system was developed to increase phosphate removal from domestic wastewater, with reduced energy consumption, using a titanium charging (inert) electrode and a sacrificial iron anode. In the MEAEC, an electric field was applied between the inert electrode (titanium) and an air cathode to drive migration of phosphate anions towards the sacrificial anode. Current was then applied between the sacrificial anode (Fe or Al mesh) and the air cathode to drive electrocoagulation of phosphate. A MEAEC with the Fe electrode using primary clarifier effluent achieved 98% phosphate removal, producing water with a total phosphorus of 0.3 mg/L with <6 min total treatment time (five cycles; each 10 s inert electrode charging, and 1 min electrocoagulation), at a constant current density of 1 mA/cm2. In the absence of the 10 s charging time, electrocoagulation required 15 min for the same removal. With an aluminum anode and the same phosphorus removal, the MEAEC required 7 cycles (7 min total treatment, 1 min 10 s total charging), while conventional electrocoagulation required 20 min. The energy demand of Fe-MEAEC was only 0.039 kWh/m3 for 98% phosphate removal, which was 35% less than with the Al-MEAEC of 0.06 kWh/m3, and 28% less than that previously obtained using an inert graphite electrode. Analysis of the precipitate showed that a less porous precipitate was obtained with the Al anode than with the Fe anode. The phosphorus in precipitate of Fe-MEAEC was identified as PO43- and HPO42-, while the Fe was present as both Fe2+ and Fe3+. Only HPO42- and Al3+ were identified in the precipitate of the Al-MEAEC. These results indicated that the MEAEC with a titanium inert charging electrode and iron anode could achieve the most efficient phosphate removal with very low energy demands, compared to previous electrochemical approaches.


Assuntos
Técnicas Eletroquímicas , Fosfatos/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Alumínio/química , Eletricidade , Eletrodos , Floculação , Ferro/química , Titânio/química , Águas Residuárias/química
20.
Biomed Pharmacother ; 86: 136-142, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27960135

RESUMO

Pre-therapeutic cryopreservation of ovarian tissue and subsequent transplantation after disease remission has recently emerged as an option to restore endocrinal function and preserve fertility for patients subjected to gonadotoxic treatments such as chemotherapy. However, the relatively low survival rate of follicles after grafting the frozen-thawed ovarian tissue largely limited the application of this technique. Gonadotropin-releasing hormone analogues (GnRHa), owing to their endocrinal regulatory effect, have been successfully used for fertility preservation against gonadotoxic conditions such as cytotoxic agents based anti-cancer therapy. In this study, we evaluated the potential protective effect of precedent GnRHa treatment before cryopreservation on freezing-thawing related follicular damages using a rat autoxenograft model. We have observed that GnRHa significantly increases the fraction of follicles with normal morphology, while presenting negnigible effect on the physiological recovery of the grafted follicular tissue, as demonstrated by the estrous cycle, folliculogenesis and post-autograft vascularization. Our data implicates that GnRHa pretreatment may effectively increase the efficacy of cryopreservation and the subsequent successful rate of transplantation.


Assuntos
Criopreservação/métodos , Hormônio Liberador de Gonadotropina/análogos & derivados , Transplante de Órgãos/métodos , Ovário/efeitos dos fármacos , Ovário/transplante , Animais , Feminino , Hormônio Liberador de Gonadotropina/administração & dosagem , Ovário/fisiologia , Ratos , Ratos Sprague-Dawley , Transplante Autólogo/métodos , Resultado do Tratamento
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