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1.
Risk Anal ; 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37853542

RESUMO

Recent events, including COVID-19, extreme floods, and explosion accidents, commonly induced localized closures and disruptions of urban road networks (URNs), resulting in significant impacts on human mobility and socio-economic activities. Existing studies on URN resilience to those events mainly took few cases for empirical studies, limiting our understanding on the URN resilience patterns across different cities. By conducting a large-scale nationwide resilience analysis of URNs in 363 cities in mainland China, this study attempts to uncover the resilience patterns of URNs against the worst-case single (SLDs) and multiple localized disruptions (MLDs). Results show that the distance from the worst-case SLD to the city center would be less than 5 km in 62.3% cities, as opposed to more than 15 km in 14.3% cities. Moreover, the average road network resilience of cities in western China could be 7% and 13% smaller than that of the eastern cities under the worst-case SLDs and MLDs, respectively. This inequality in the worst-case resilience is partly attributable to variations in urban socio-economic, infrastructure-related, and topographic factors. These findings could inspire nationwide pre-disaster mitigation strategies to cope with localized disruptions and help transfer insights for mitigation strategies against disruptive events across cities.

2.
Chaos ; 33(7)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37433653

RESUMO

Urban road networks (URNs), as simplified views and important components of cities, have different structures, resulting in varying levels of transport efficiency, accessibility, resilience, and many socio-economic indicators. Thus, topological characteristics of URNs have received great attention in the literature, while existing studies have used various boundaries to extract URNs for analysis. This naturally leads to the question of whether topological patterns concluded using small-size boundaries keep consistent with those uncovered using commonly adopted administrative boundaries or daily travel range-based boundaries. This paper conducts a large-scale empirical analysis to reveal the boundary effects on 22 topological metrics of URNs across 363 cities in mainland China. Statistical results show that boundaries have negligible effects on the average node degree, edge density, orientation entropy of road segments, and the eccentricity for the shortest or fastest routes, while other metrics including the clustering coefficient, proportion of high-level road segments, and average edge length together with route-related metrics such as average angular deviation show significant differences between road networks extracted using different boundaries. In addition, the high-centrality components identified using varied boundaries show significant differences in terms of their locations, with only 21%-28% of high-centrality nodes overlapping between the road networks extracted using administrative and daily travel range-based boundaries. These findings provide useful insights to assist urban planning and better predict the influence of a road network structure on the movement of people and the flow of socio-economic activities, particularly in the context of rapid urbanization and the ever-increasing sprawl of road networks.

3.
Nature ; 535(7611): 252-7, 2016 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-27338790

RESUMO

Immunomodulatory drugs bind to cereblon (CRBN) to confer differentiated substrate specificity on the CRL4(CRBN) E3 ubiquitin ligase. Here we report the identification of a new cereblon modulator, CC-885, with potent anti-tumour activity. The anti-tumour activity of CC-885 is mediated through the cereblon-dependent ubiquitination and degradation of the translation termination factor GSPT1. Patient-derived acute myeloid leukaemia tumour cells exhibit high sensitivity to CC-885, indicating the clinical potential of this mechanism. Crystallographic studies of the CRBN-DDB1-CC-885-GSPT1 complex reveal that GSPT1 binds to cereblon through a surface turn containing a glycine residue at a key position, interacting with both CC-885 and a 'hotspot' on the cereblon surface. Although GSPT1 possesses no obvious structural, sequence or functional homology to previously known cereblon substrates, mutational analysis and modelling indicate that the cereblon substrate Ikaros uses a similar structural feature to bind cereblon, suggesting a common motif for substrate recruitment. These findings define a structural degron underlying cereblon 'neosubstrate' selectivity, and identify an anti-tumour target rendered druggable by cereblon modulation.


Assuntos
Antineoplásicos/farmacologia , Peptídeo Hidrolases/metabolismo , Fatores de Terminação de Peptídeos/metabolismo , Compostos de Fenilureia/farmacologia , Talidomida/análogos & derivados , Proteínas Adaptadoras de Transdução de Sinal , Motivos de Aminoácidos , Antineoplásicos/química , Sítios de Ligação , Cristalografia por Raios X , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Humanos , Fator de Transcrição Ikaros/química , Fator de Transcrição Ikaros/metabolismo , Modelos Moleculares , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Peptídeo Hidrolases/química , Fatores de Terminação de Peptídeos/química , Fatores de Terminação de Peptídeos/deficiência , Compostos de Fenilureia/química , Ligação Proteica , Proteólise/efeitos dos fármacos , Especificidade por Substrato , Talidomida/química , Talidomida/farmacologia , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo
4.
World J Surg ; 46(3): 600-609, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34704148

RESUMO

BACKGROUND: Transoral endoscopic thyroidectomy, a novel technique, uses oral vestibule as the entry point and leaves no scar on the body surface. However, because the incisions are close to the mental nerve, nerve damage and the associated sensory impairment are concerning. Herein, we evaluated sensory alteration after transoral endoscopic thyroidectomy and determined factors associated with the prolonged sensory alteration. METHODS: Patients who underwent transoral endoscopic thyroidectomy were enrolled. Sensation over the lower lip, chin, and neck was evaluated before and after the surgery. A self-assessment questionnaire, Semmes-Weinstein monofilament test, and two-point discrimination test were used to subjectively and objectively evaluate sensory changes. RESULTS: Fifty-one patients were enrolled; most of them reported altered sensation, with chin (72.5%) being the most common site, followed by lower lip (52.9%), upper neck (33.3%), and lower neck (5.9%) on postoperative day 2. The sensory disturbance resolved within 3 months. Factors associated with prolonged sensory alteration are male sex and old age. Fourteen patients (27.5%) experienced mild drooling from the mouth, which was usually self-limiting in 1 month. Sensory impairments in light touch pressure threshold and two-point discrimination were significant in the chin and neck on postoperative day 2 and at 1 week. The ability to discern two-point was also compromised in the lower lip on postoperative day 2. All these significant changes normalized to preoperative baseline at 1 month. CONCLUSIONS: There was an altered sensation after transoral endoscopic thyroidectomy with the most common and disturbed in the chin. Sensory impairment was usually transient and recovered in 3 months.


Assuntos
Cirurgia Endoscópica por Orifício Natural , Tireoidectomia , Endoscopia , Humanos , Masculino , Boca , Pescoço , Sensação , Tireoidectomia/efeitos adversos
5.
World J Surg ; 45(6): 1779-1784, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33641001

RESUMO

BACKGROUND: The transoral approach and the bilateral axillo-breast approach (BABA) are remote access approaches for endoscopic thyroidectomy. Both follow a symmetric design and use CO2 insufflation to maintain the working space. The outcome differences between the techniques are rarely compared in the literature. METHODS: All patients who underwent endoscopic transoral (n = 72) and BABA (n = 63) thyroidectomy between October 2018 and August 2020 by a single surgeon were retrospectively reviewed. The following peri-operative data were collected and compared: operative time, blood loss, postoperative drainage amount, hospital stay, pain score, number of retrieved lymph nodes, and complications. RESULTS: Patients in the transoral group were younger (44.7 vs. 49.3 years, p = 0.022) and had smaller tumors (2.4 vs. 2.8 cm, p = 0.020) than those in the BABA group. The operative times were significantly longer in the transoral group than in the BABA group (lobectomy, 194.1 vs. 177.0 min, p = 0.026; total thyroidectomy, 246.0 vs. 214.3 min, p = 0.042). Nevertheless, the time difference became insignificant after completing the initial 20 cases of transoral thyroidectomy. The drainage fluid collected after the surgery was serosanguinous, and a lower drainage volume was observed in the transoral group than that in the BABA group (64.9 vs. 78.5 ml, p = 0.017). However, there was no significant difference regarding the blood loss, hospital stay, postoperative pain score, and lymph nodes retrieved. The rate of postoperative complications, such as hypoparathyroidism and vocal cord palsy was comparable between the two groups. CONCLUSIONS: Transoral approach and BABA are comparable with regard to surgical outcomes. Selected patients may choose either technique based on their preferences.


Assuntos
Procedimentos Cirúrgicos Robóticos , Cirurgiões , Neoplasias da Glândula Tireoide , Axila , Mama , Humanos , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Resultado do Tratamento
6.
BMC Anesthesiol ; 21(1): 170, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34126924

RESUMO

BACKGROUND: Transoral thyroidectomy can be performed using nasal or oral intubation. Recently, we encountered two cases of vocal cord granuloma that were suspected to result from intraoperative compression by the oral endotracheal tube. CASES PRESENTATION: Two women underwent transoral endoscopic thyroidectomy with oral endotracheal tubes fixed at the mouth angle. Their initial postoperative recovery was uneventful, but they developed hoarseness 2 months after the surgery. Subsequent strobolaryngoscopy revealed vocal cord granulomas at the side of contact of the endotracheal tube. One patient received medication and voice therapy, and her granuloma shrank significantly one month later. The other patient underwent granuloma resection. Thereafter, the symptoms improved in both the patients. CONCLUSIONS: Oral intubation with tube placement at the mouth angle might result in the formation of vocal cord granulomas. Therefore, we suggest positioning the tube at the midline to avoid excessive irritation on one side of the vocal cord.


Assuntos
Granuloma Laríngeo/etiologia , Intubação Intratraqueal/efeitos adversos , Complicações Pós-Operatórias/patologia , Prega Vocal/patologia , Adulto , Endoscopia/métodos , Feminino , Granuloma Laríngeo/diagnóstico , Granuloma Laríngeo/terapia , Rouquidão/etiologia , Humanos , Intubação Intratraqueal/métodos , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/terapia , Tireoidectomia/métodos , Fatores de Tempo
7.
J Struct Eng (N Y N Y) ; 144(5)2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29881140

RESUMO

ASCE 7 is moving toward adopting load requirements that are consistent with risk-informed design goals characteristic of performance-based engineering (PBE). ASCE 7-10 provided wind maps that correspond to return periods of 300, 700, and 1,700 years for Risk Categories I, II, and combined III/IV, respectively. The risk targets for Risk Categories III and IV buildings and other structures (designated as essential facilities) are different in PBE. The reliability analyses reported in this paper were conducted using updated wind load data to (1) confirm that the return periods already in ASCE 7-10 were also appropriate for risk-informed PBE, and (2) to determine a new risk-based return period for Risk Category IV. The use of data for wind directionality factor, Kd , which has become available from recent wind tunnel tests, revealed that reliabilities associated with wind load combinations for Risk Category II structures are, in fact, consistent with the reliabilities associated with the ASCE 7 gravity load combinations. This paper shows that the new wind maps in ASCE 7-16, which are based on return periods of 300, 700, 1,700, and 3,000 years for Risk Categories I, II, III, and IV, respectively), achieve the reliability targets in Section 1.3.1.3 of ASCE 7-16 for nonhurricane wind loads.

8.
BMC Infect Dis ; 16(1): 444, 2016 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-27553962

RESUMO

BACKGROUND: Multidrug-resistant Pseudomonas aeruginosa has emerged as one of the most important healthcare-associated pathogens. Colistin is regarded as the last-resort antibiotic for multidrug-resistant Gram-negative bacteria, but is associated with high rates of acute kidney injury. The aim of this in vitro study is to search for an alternative treatment to colistin for multidrug-resistant P. aeruginosa infections. METHODS: Multidrug and carbapenem-resistant P. aeruginosa isolates were collected between January 2009 and December 2012 at MacKay Memorial Hospital. Minimal inhibitory concentrations (MICs) were determined for various antibiotic combinations. Carbapenemase-producing genes including bla VIM, other ß-lactamase genes and porin mutations were screened by PCR and sequencing. The efficacy of carbapenems (imipenem, meropenem, doripenem) with or without rifampicin was correlated with the type of porin mutation (frameshift mutation, premature stop codon mutation) in multidrug-resistant P. aeruginosa isolates without carbapenemase-producing genes. RESULTS: Of the 71 multidrug-resistant clinical P. aeruginosa isolates, only six harboured the bla VIM gene. Imipenem, meropenem and doripenem were significantly more effective (reduced fold-change of MICs) when combined with rifampicin in bla VIM-negative isolates, especially in isolates with porin frameshift mutation. CONCLUSIONS: Imipenem + rifampicin combination has a low MIC against multidrug-resistant P. aeruginosa, especially in isolates with porin frameshift mutation. The imipenem + rifampicin combination may provide an alternative treatment to colistin for multidrug -resistant P. aeruginosa infections, especially for patients with renal insufficiency.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Colistina/uso terapêutico , Doripenem , Quimioterapia Combinada , Feminino , Humanos , Imipenem/farmacologia , Masculino , Meropeném , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Porinas/genética , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , Rifampina/farmacologia , Taiwan , Tienamicinas/farmacologia , beta-Lactamases/genética
9.
J Infect Dis ; 210(6): 982-91, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24620021

RESUMO

Group B streptococcus (GBS) can cause severe disease in susceptible hosts, including newborns, pregnant women, and the elderly. GBS serine-rich repeat (Srr) surface glycoproteins are important adhesins/invasins in multiple host tissues, including the vagina. However, exact molecular mechanisms contributing to their importance in colonization are unknown. We have recently determined that Srr proteins contain a fibrinogen-binding region (BR) and hypothesize that Srr-mediated fibrinogen binding may contribute to GBS cervicovaginal colonization. In this study, we observed that fibrinogen enhanced wild-type GBS attachment to cervical and vaginal epithelium, and that this was dependent on Srr1. Moreover, purified Srr1-BR peptide bound directly to host cells, and peptide administration in vivo reduced GBS recovery from the vaginal tract. Furthermore, a GBS mutant strain lacking only the Srr1 "latching" domain exhibited decreased adherence in vitro and decreased persistence in a mouse model of GBS vaginal colonization, suggesting the importance of Srr-fibrinogen interactions in the female reproductive tract.


Assuntos
Adesinas Bacterianas/fisiologia , Fibrinogênio/metabolismo , Glicoproteínas de Membrana/fisiologia , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/patogenicidade , Vagina/microbiologia , Animais , Aderência Bacteriana , Linhagem Celular , Modelos Animais de Doenças , Epitélio/microbiologia , Feminino , Camundongos , Serina , Streptococcus agalactiae/fisiologia , Doenças Vaginais/microbiologia
10.
Antimicrob Agents Chemother ; 58(1): 201-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24145535

RESUMO

The frequency of the carbapenem-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii (CRACB) complex increases annually in our hospitals. However, the types and prevalence of carbapenemases among isolates still remain unclear. In this study, we identified and collected 672 carbapenem-resistant isolates from a medical center in Northern Taiwan between April and December of 2010. There were 577 genospecies 2 (Acinetobacter baumannii), 79 genospecies 13TU, and 16 genospecies 3 isolates. The isolates had an acquired blaOXA-24-like gene, which was confirmed by sequencing for the encoded OXA-72 carbapenemase, and were often associated with high-level carbapenem resistance. These CRACB complex isolates remained susceptible to colistin (100%). The genotyping of isolates was conducted using pulsed-field gel electrophoresis with ApaI digestion. In most clonally related groups, patients were from both branch hospitals. The results indicate that interhospital dissemination of clones occurred. This study provides updated data on the types and prevalence of the CRACB complex. In addition, it presents a warning on the emergence and spread of CRACB complex harboring blaOXA-24-like genes in northern Taiwan.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Acinetobacter/efeitos dos fármacos , Acinetobacter/genética , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Prevalência , Taiwan
11.
Cell Microbiol ; 15(7): 1154-67, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23298320

RESUMO

Streptococcus agalactiae (Group B Streptococcus, GBS) is a frequent commensal organism of the vaginal tract of healthy women. However, GBS can transition to a pathogen in susceptible hosts, but host and microbial factors that contribute to this conversion are not well understood. GBS CovR/S (CsrR/S) is a two component regulatory system that regulates key virulence elements including adherence and toxin production. We performed global transcription profiling of human vaginal epithelial cells exposed to WT, CovR deficient, and toxin deficient strains, and observed that insufficient regulation by CovR and subsequent increased toxin production results in a drastic increase in host inflammatory responses, particularly in cytokine signalling pathways promoted by IL-8 and CXCL2. Additionally, we observed that CovR regulation impacts epithelial cell attachment and intracellular invasion. In our mouse model of GBS vaginal colonization, we further demonstrated that CovR regulation promotes vaginal persistence, as infection with a CovR deficient strainresulted in a heightened host immune response as measured by cytokine production and neutrophil activation. Using CXCr2 KO mice, we determined that this immune alteration occurs, at least in part, via signalling through the CXCL2 receptor. Taken together, we conclude that CovR is an important regulator of GBS vaginal colonization and loss of this regulatory function may contribute to the inflammatory havoc seen during the course of infection.


Assuntos
Regulação da Expressão Gênica , Proteínas Repressoras/metabolismo , Transdução de Sinais , Streptococcus agalactiae/imunologia , Streptococcus agalactiae/patogenicidade , Vagina/imunologia , Vagina/microbiologia , Animais , Proteínas de Bactérias/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Feminino , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Camundongos , Camundongos Knockout , Receptores de Interleucina-8B/genética , Receptores de Interleucina-8B/imunologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia
12.
IEEE Trans Vis Comput Graph ; 30(1): 847-857, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37878448

RESUMO

The provision of fire services plays a vital role in ensuring the safety of residents' lives and property. The spatial layout of fire stations is closely linked to the efficiency of fire rescue operations. Traditional approaches have primarily relied on mathematical planning models to generate appropriate layouts by summarizing relevant evaluation criteria. However, this optimization process presents significant challenges due to the extensive decision space, inherent conflicts among criteria, and decision-makers' preferences. To address these challenges, we propose FSLens, an interactive visual analytics system that enables in-depth evaluation and rational optimization of fire station layout. Our approach integrates fire records and correlation features to reveal fire occurrence patterns and influencing factors using spatiotemporal sequence forecasting. We design an interactive visualization method to explore areas within the city that are potentially under-resourced for fire service based on the fire distribution and existing fire station layout. Moreover, we develop a collaborative human-computer multi-criteria decision model that generates multiple candidate solutions for optimizing firefighting resources within these areas. We simulate and compare the impact of different solutions on the original layout through well-designed visualizations, providing decision-makers with the most satisfactory solution. We demonstrate the effectiveness of our approach through one case study with real-world datasets. The feedback from domain experts indicates that our system helps them to better identify and improve potential gaps in the current fire station layout.

13.
Sci Total Environ ; 859(Pt 1): 160131, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36372162

RESUMO

Microbial electrochemical system (MES) is an emerging wastewater treatment technology that compensates the energy demands of containments removal by in situ converting the chemical energy of organic pollutants. As the structure for exoelectrogens and the reaction site of extracellular electron transfer (EET), the anode is essential for MES. The future commercial application of MES requires efficiency and large-scale fabrication available anode. In this study, a 3D anode with millimeter-scale pores (3D-MPA) was successfully constructed by sacrificial template method, with low-cost phenolic resin as carbon precursor and polymethyl methacrylate (PMMA) pellets as template. With customized and ordered pore of 1 mm, the 3D-MPAs allowed the microorganisms to colonize inside, improving anodic space utilization efficiency. Different carbonization temperature in tested range from 700 °C to 1000 °C regulated the micrometer-scale convex structures and surface roughness of 3D-MPAs, causing electrochemical performance changes. The 3D-MPA-900 obtained the largest electroactive surface area (102 ± 4.1 cm2) and smallest ohmic resistance (1.8 ± 0.09 Ω). Equipped with MES, 3D-MPA-900 reached the highest power density and current density (2590 ± 25 mW m-2 and 5.20 ± 0.07 A m-2). Among tested 3D-MPA, the excellent performance of 3D-MPA-900 might be attributed by its convex structures with suitable size and surface coverage. The surface roughness of 3D-MPA-900 enhanced the microorganism adherence, which then promoted EET on anode surface. Generally, phenolic-based 3D-MPA made of sacrificial-template method had controllable porous structure, large-scale fabrication availability, high chemical stability and excellent mechanical property, which could be promising for the commercial application of MES.


Assuntos
Fontes de Energia Bioelétrica , Carbono , Carbono/química , Fontes de Energia Bioelétrica/microbiologia , Eletrodos , Transporte de Elétrons , Bactérias
14.
J Vis Exp ; (195)2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-37246864

RESUMO

The dried root of Aconitum pendulum Busch., called Tiebangchui (TBC) in Chinese, is one of the most famous Tibetan medicines. It is a widely used herb in northwest China. However, many cases of poisoning have occurred because of TBC's intense toxicity and because its therapeutic and toxic doses are similar. Therefore, finding a safe and effective method to reduce its toxicity is an urgent task. A search through the Tibetan medicine classics shows that the processing method of TBC stir-fried with Zanba was recorded in the "Processing specification of Tibetan medicine of Qinghai Province (2010)". However, the specific processing parameters are not yet clear. Thus, this study aims to optimize and standardize the processing technology of Zanba-stir-fried TBC. First, a single-factor experiment was conducted on four factors: the slice thickness of TBC, amount of Zanba, processing temperature, and time. With monoester and diester alkaloid contents in Zanba-stir-fried TBC as indexes, CRITIC combined with the Box-Behnken response surface method was used to optimize the processing technology of Zanba-stir-fried TBC. The optimized processing conditions of Zanba-stir-fried TBC were a TBC slice thickness of 2 cm, three times more Zanba than TBC, a processing temperature of 125 °C, and 60 min of stir-frying. This study determined the optimized and standard processing conditions for the usage of Zanba-stir-fried TBC, thus providing an experimental basis for the safe clinical use and industrial production of Zanba-stir-fried TBC.


Assuntos
Plantas Medicinais , China , Medicina Tradicional Tibetana , Tecnologia , Temperatura
15.
Sci Total Environ ; 898: 165448, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37442459

RESUMO

Porous anodes improve system performance in microbial electrochemical systems by increasing the specific surface area for electroactive bacteria. In this study, multilayer anodes with different pore diameters were constructed to assess the impact of pore size and depth on anode performance. This layered structure makes detecting electroactive biofilms more accessible layer by layer, which is the first study to examine electroactive biofilms' molecular biology and electrochemical properties at different depths in pores with varied pore sizes. The millimeter-scale pores inside the bioanode have a limited effect in increasing power. The larger the pore diameter, the higher the maximum power density (Pmax) obtained. The Pmax of anodes with 4 mm pore (1.91 ± 0.15 W m-2) was 1.4 times higher than that of the non-perforated (1.37 ± 0.07 W m-2) and 0.5 mm pore anodes (1.39 ± 0.04 W m-2). Electricigens can colonize into pore channels for at least 10 mm with a pore diameter ≥3 mm and current densities >0.05 A m-2. However, in the pores channel with 0.5 mm diameter, electricigens can only colonize to a depth of 2 mm. The biofilm thickness, electricity output, metabolic activity, and biocommunity changed with pore depth and were restricted by the limited mass transfer. The Geobacter sp. was the dominant species in inter-pore biofilms, with 43.8 %-78.6 % in abundance and decreased in quantity as pore depth increased. The inter-pore biofilms on the outer layer contributed a current density of 0.17 ± 0.003 A m-2, while that of the inner layer was only 0.02 ± 0.01 A m-2. Further studies found that the pore edge mass transfer effect can contribute up to 75 % of the current. The mass transfer process at the pore edge region could be a multidirectional mass transfer rather than a pore channel mass transfer.

16.
Chemosphere ; 331: 138819, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37127198

RESUMO

Electron-donor Lacking was the limiting factor for the denitrification of oligotrophic groundwater and hydrogenotrophic denitrification provided an efficient approach without secondary pollution. In this study, a hybrid system with microbial electrolysis cell (MEC) assisted hydrogen-based membrane biofilm reactor (MBfR) was established for advanced groundwater denitrification. The liquid-gas phase transition prevented the potential pollution from organic wastes in MEC to groundwater, while the bubble-free diffusion of MBfR promoted hydrogen utilization efficiency. The negative-pressure extraction from MEC and the positive pressure for gas supply into MBfR increased the hydrogen proportion and current density of MEC, and improved the kinetic constant K of the denitrification reaction in MBfR. With actual groundwater, the MEC-MBfR hybrid system achieved a nitrate reduction of 97.8% with an effluent NO3--N of 2.2 ± 1.0 mg L-1. The hydrogenotrophic denitrifiers of Thauera, Pannonibacter, and Azonexus, dominated the denitrification biofilm on the membrane and elastic filler in MBfR.


Assuntos
Desnitrificação , Água Subterrânea , Reatores Biológicos , Nitratos/metabolismo , Hidrogênio , Biofilmes , Eletrólise
17.
Water Res ; 219: 118570, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35597221

RESUMO

When facing wastewater with high organic and ammonia, e. g. swine wastewater, microbial electrolysis cell (MEC) is emerging for energy extraction as hydrogen and methane. However, the effects of highly concentrated ammonia on MEC haven't been fully evaluated. In this study, single-chamber MECs were operated with acetate and sucrose as substrates under various ammonia concentrations. The current generally increased with ammonia loading from 80 to 3000 mg L-1. Yet, the substrate consumption in MECs was inhibited with ammonia concentrations above 1000 mg L-1. As a combined result, the energy recovery efficiency of MECs was stable. The electrochemical activity of anode biofilm reached the peak under 1000 mg L-1 ammonia and was restricted under higher ammonia loadings. Under neutral pH, the NH4+ increases the cell membrane permeability, which benefited the electrochemical activity of exoelectrogens to a proper extent. Nevertheless, the toxic ammonia also accelerated the anode biomass loss and stimulated the extracellular polymeric substance (EPS) secretion. Due to the current increase, the abundance of exoelectrogens generally raised with ammonia loading from 80 to 3000 mg L-1. However, except for anode biomass loss, the carbon and methane metabolism pathways were inhibited in acetate-fed MEC, while the glycolysis acted as the rate-limiting step for substrate degradation in sucrose-fed conditions. This study systematically examined the influences of high ammonia loading on MEC performances, bio-community and anode electrochemical activities, and evaluated practical feasibility and application inch of MECs for the energy recovery and pollutant removal of high concentration organic and ammonia wastewater.


Assuntos
Fontes de Energia Bioelétrica , Purificação da Água , Acetatos/metabolismo , Amônia , Animais , Biofilmes , Eletrodos , Eletrólise , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Hidrogênio/metabolismo , Metano , Sacarose , Suínos , Águas Residuárias
18.
ACS Appl Mater Interfaces ; 14(34): 39441-39450, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35993697

RESUMO

NaCl has been successfully used as a template for the synthesis of 2D nanomaterials, but it is seldom used for the construction of flat small organic molecules. Herein, a simple, low-cost, and highly efficient synthesis of phenazines with planar main frames, such as 5-phenyl-5,14-dihydro-5,7,12,14-tetraazapentacene, in the presence of NaCl micro-crystal as a kind of molecular mold is described. The reactants were mixed with NaCl powder and heated to 320 °C for 5 min. Yields >90% were readily achieved after a simple precipitation in water. The effectiveness of NaCl crystal as a mold with HCl was confirmed by comparison with common inorganic salts, SiO2, and γ-Al2O3 with HCl together with combinations including NaNO3 + HNO3, Na2SO4 + H2SO4, NaH2PO4 + H3PO4, and NaH2PO4 + polyphosphoric acid. The mechanism was deduced with the aid of computer simulation, which confirms the stabilization of 5,14-dihydro-5,7,12,14-tetraazapentacene by the NaCl surface. DMSO solution of a product, 1,3-dihydro-imidazo[4,5-b]phenazin-2-one, showed enhanced fluorescence in H2O, and it was used as a fluorescent probe for pH and Hg2+. A full-color material was prepared by mixing precursors of epoxy resin and phenazines, and its fluorescent color could be adjusted by the ratio of phenazines.

19.
Water Res ; 225: 119064, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36130438

RESUMO

Microbial electrolysis cell (MEC) is a promising technology for effective energy conversion of wastewater organics to biogas. Yet, in swine wastewater treatment, the complex contaminants including antibiotics may affect MEC performance, while the high ammonia concentration might increase this risk by increasing cell membrane permeability. In this work, the responses of MECs on tetracycline (TC) with low and high ammonia loadings (80 and 1000 mg L-1) were fully investigated. The TC of 0 to 1 mg L-1 slightly improved MEC performance in current production and electrochemical characteristics with low ammonia loading, while TC ≥ 4 mg L-1 started to show negative effects. Generally, the high ammonia loading sensitized MECs to TC concentration, inducing the current and COD removal of MECs to sharply decline with TC ≥ 0.5 mg L-1. The positive effect of high ammonia loading on MEC due to conductivity increase was counteracted with TC ≥ 1 mg L-1. The co-contamination of TC and ammonia significantly decreased the bioactivity and biomass of anode biofilm. Although the high concentration of co-existing TC and ammonia inhibited MEC performance, the reactors still obtained positive energy feedback. The network analyses indicated that the effluent suspension contributed much to antibiotic resistance gene (ARG) transmission, while the microplastics (MPs) in wastewater greatly raised the risks of ARGs spreading. This work systematically examined the synergetic effects of TC and ammonia and the transmission of ARGs in MEC operation, which is conducive to expediting the application of MECs in swine wastewater treatment.


Assuntos
Amônia , Águas Residuárias , Suínos , Animais , Biocombustíveis , Microplásticos , Plásticos , Eletrólise , Tetraciclina/farmacologia , Antibacterianos/farmacologia
20.
J Microbiol Immunol Infect ; 55(6 Pt 2): 1229-1238, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34824020

RESUMO

BACKGROUND/PURPOSE: Carbapenem-nonsusceptible Enterobacterales (CNSE) are a growing global threat. Carbapenemases are often produced by plasmids, which allow rapid transmission. This study aimed to investigate (1) the bacterial type (2) resistant genes (3) antimicrobial susceptibility and (4) risk factors for acquisition of carbapenemase-producing carbapenem-nonsusceptible Enterobacterales (CP-CNSE) and non-carbapenemase-producing carbapenem-nonsusceptible Enterobacterales (non-CP-CNSE) bacteremia. METHODS: There were a total of 113 isolates of Enterobacterales from 2013 to 2018. After excluding nonblood isolates and including only one sample from each patient, 99 isolates were analyzed and the medical charts of these patients were reviewed. Carbapenemase genes, ß-lactamase genes and antimicrobial susceptibility of the isolates were determined. Multilocus sequence typing (MLST) was performed on CP-CNSE isolates. RESULTS: CP-CNSE carried more blaSHV (P = 0.004) and were more resistant to imipenem than non-CP-CNSE (P < 0.001). In the univariate analyses, we found that CP-CNSE bloodstream infection was associated with patient <65 years of age (odds ratio, 3.90; 95% confidence interval [CI], 1.16 to 13.10; P = 0.027), mechanical ventilation at the time of bloodstream infection (BSI) (odds ratio, 3.85; 95% CI, 1.16-12.78; P = 0.028) and exposure to piperacillin/tazobactam (odds ratio, 3.96; 95% CI, 1.09-14.38; P = 0.037). However, on multivariate analyses, no independent predictor for CP-CNSE was identified in this study. CONCLUSION: CP-CNSE carried more blaSHV and were more resistant to imipenem when compared to non-CP-CNSE. No independent predictor for CP-CNSE was identified after multivariate analysis. This is the first study conducted in Taiwan comparing risk factors between CP-CNSE and non-CP-CNSE from both clinical and molecular aspects.


Assuntos
Antibacterianos , Bacteriemia , Proteínas de Bactérias , Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Imipenem , beta-Lactamases , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Proteínas de Bactérias/genética , beta-Lactamases/genética , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Infecções por Enterobacteriaceae/complicações , Infecções por Enterobacteriaceae/diagnóstico , Infecções por Enterobacteriaceae/tratamento farmacológico , Imipenem/farmacologia , Imipenem/uso terapêutico , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fatores de Risco , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação
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