Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Chronic Illn ; 19(3): 646-664, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-35957597

RESUMEN

OBJECTIVES: With about half of older adults reporting feelings of loneliness, interventions are needed to improve connectedness among our aging population. The health benefits of Chronic Disease Self-Management Education (CDSME) programs are well documented, but workshops' ability to reduce loneliness remains unknown. METHODS: Using the Campaign to End Loneliness Measurement Tool, we examined 295 CDSME participants' loneliness changes before and after the 6-week face-to-face workshops. Statistical analyzes used generalized estimating equations (GEE). RESULTS: On average, participants were age 74.3(±8.9) years and self-reported 3.3(±2.2) chronic conditions. The majority of participants were female (83%) and attended workshops in English (77%). Significant reductions in loneliness scores were observed from baseline to post-workshop (p < 0.001). DISCUSSION: Findings expand our understanding about the benefits of small-group CDSME workshops to reduce loneliness among participants. CDSME workshops may reduce loneliness because of their highly interactive and process-driven format and ability to create bonds between participants with chronic conditions and shared experiences.


Asunto(s)
Soledad , Automanejo , Humanos , Masculino , Femenino , Anciano , Automanejo/educación , Autoinforme , Emociones , Enfermedad Crónica
2.
Bioresour Technol Rep ; 15: 100737, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34179735

RESUMEN

Water is one of many viral transmission routes, and the presence of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) in wastewater has brought attention to its treatment. SARS CoV-2 primarily transmits in the air but the persistence of the virus in the water possibly can serve as a secondary source even though current studies do not show this. In this paper, an evaluation of the current literature with regards to the treatment of SARS-CoV-2 in wastewater treatment plant (WWTP) effluents and biosolids is presented. Treatment efficiencies of WWTPs are compared for viral load reduction on the basis of publicly available data. The results of this evaluation indicate that existing WWTPs are effectively removing 1-6 log10 viable SARS-CoV-2. However, sludge and biosolids provide an umbrella of protection from treatment and inactivation to the virus. Hence, sludge treatment factors like high temperature, pH changes, and predatory microorganisms can effectively inactivate SARS-CoV-2.

4.
Bioelectrochemistry ; 127: 1-11, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30614442

RESUMEN

Constructed wetland microbial fuel cells (CW-MFCs) or phyto-power systems are integrated bioelectrochemical systems (BES) that can sustainably harvest electricity from the anaerobic respiration of rhizospheric bacteria. This integration of techniques shows a promise in phytoremediation of wastewater along with bioenergy generation. In CW-MFCs, electrons harvested in anaerobic respiration of bacteria proliferating in the rhizospheric zone are electrochemically coupled with electron acceptors at the aerobic cathode submersed in water. Use of indigenous non-food plants in CW-MFCs has gained increasing interest primarily due to high yield of biomass that can be applied for other bioenergy purposes and bioaccumulation of pollutants. Furthermore, CW-MFCs can provide other benefits such as wastewater treatment, carbon dioxide assimilation, power generation and air purification. Microbial interaction with plant roots (rhizosphere), isolated species from the phyto-systems, with soil particles and pollutants are reviewed in this paper. In addition, successful applications of CW-MFCs are discussed with focus on power generation, the role of plant-microbe interactions as well as evaluating the critical operational parameters and their effect on power generation output efficiency.


Asunto(s)
Fuentes de Energía Bioeléctrica/microbiología , Fenómenos Fisiológicos de las Plantas , Purificación del Agua/métodos , Humedales , Biodegradación Ambiental , Electricidad , Electrodos , Diseño de Equipo , Aguas Residuales/análisis , Aguas Residuales/microbiología
5.
Appl Biochem Biotechnol ; 186(4): 1017-1033, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29808454

RESUMEN

Microbial fuel cells (MFCs) have potential to treat industrial wastewater containing organic compounds and simultaneously generate power. Organic compounds include textile dyes with various chromophore groups, which can be decolorized reductively by microorganisms under anaerobic conditions. In the present study, we examined the decolorization of Reactive Black 5 (RB5) azo dye and Reactive Blue 4 (RBL4) anthraquinone dye under open circuit potential in MFCs with graphite plate and graphite felt electrodes and a microbial consortium originally derived from bovine rumen fluid. RB5 dye was more than 90% decolorized in 120, 165, and 225 min at 50, 100, and 200 mg L-1 concentrations, respectively. RBL4 dye at 50 and 100 mg L-1 took 225 and 300 min to decolorize, while 200 mg L-1 RBL4 dye was not decolorized at all. Under closed circuit conditions, decolorization increased with decrease in external load, whereas current generation increased with external resistance. The results demonstrate that the reductive cleavage of the chromophore was more rapid with RB5 than with RBL4.


Asunto(s)
Fuentes de Energía Bioeléctrica/microbiología , Naftalenosulfonatos/química , Triazinas/química
6.
Bioelectrochemistry ; 113: 79-84, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27816024

RESUMEN

Microbial fuel cells (MFCs) were designed for laboratory scale experiments to study electroactive biofilms in anodic chambers. Anodic biofilms and current generation during biofilm growth were examined using single chambered MFCs submersed in algal catholyte. A culture of the marine green alga Nanochloropsis salina was used as a biocatholyte, and a rumen fluid microbiota was the anodic chamber inoculum. Electrical impedance spectroscopy was performed under varying external resistance once a week to identify mass transport limitations at the biofilm-electrolyte interface during the four-week experiment. The power generation increased from 249 to 461mWm-2 during the time course. Confocal laser scanning microscopy imaging showed that the depth of the bacterial biofilm on the anode was about 65µm. There were more viable bacteria on the biofilm surface and near the biofilm-electrolyte interface as compared to those close to the anode surface. The results suggest that biofilm growth on the anode creates a conductive layer, which can help overcome mass transport limitations in MFCs.


Asunto(s)
Fuentes de Energía Bioeléctrica/microbiología , Biopelículas , Organismos Acuáticos/metabolismo , Organismos Acuáticos/fisiología , Técnicas de Cultivo , Electroquímica , Electrodos , Inmersión
7.
Case Rep Gastroenterol ; 10(2): 489-493, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27721737

RESUMEN

Clostridium septicum is a highly virulent pathogen which is associated with colorectal malignancy, hematological malignancy, immunosuppression, diabetes mellitus and cyclical neutropenia. Presentation may include disseminated clostridial infection in the form of septicemia, gas gangrene, and mycotic aortic aneurysms. We report the case of a 62-year-old female presenting with necrotizing fasciitis of her left thigh and subsequently developing rectal bleeding. While she was being treated with empiric antibiotics, her blood culture was found to be positive for C. septicum. We would like to highlight the importance of early colorectal cancer screening in minimizing the occurrence of undetected tumors which provide an optimal growth environment for C. septicum, leading to localized and/or remote infection.

8.
FEMS Microbiol Lett ; 363(6)2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26872494

RESUMEN

Biobutanol is a next-generation liquid biofuel with properties akin to those of gasoline. There is a widespread effort to commercialize biobutanol production from agricultural residues, such as corn stover, which do not compete with human and animal foods. This pursuit is backed by extensive government mandates to expand alternative energy sources. This review provides an overview of research on biobutanol production using corn stover feedstock. Structural composition, pretreatment, sugar yield (following pretreatment and hydrolysis) and generation of lignocellulose-derived microbial inhibitory compounds (LDMICs) from corn stover are discussed. The review also discusses different Clostridium species and strains employed for biobutanol production from corn stover-derived sugars with respect to solvent yields, tolerance to LDMICs and in situ solvent recovery (integrated fermentation). Further, the economics of cellulosic biobutanol production are highlighted and compared to corn starch-derived ethanol and gasoline. As discussed herein, the economic competitiveness of biobutanol production from corn stover largely depends on feedstock processing and fermentation process design.


Asunto(s)
Acetona/metabolismo , Butanoles/metabolismo , Etanol/metabolismo , Fermentación , Zea mays , Biodegradación Ambiental , Biomasa , Comercio , Destilación , Hidrólisis
9.
Int J Phytoremediation ; 17(11): 1060-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25849115

RESUMEN

Azo dyes are commonly generated as effluent pollutants by dye using industries, causing contamination of surface and ground water. Various strategies are employed to treat such wastewater; however, a multi-faceted treatment strategy could be more effective for complete removal of azo dyes from industrial effluent than any single treatment. In the present study, rice husk material was used as a substratum in two constructed wetlands (CWs) and augmented with microorganisms in the presence of wetland plants to effectively treat dye-polluted water. To evaluate the efficiency of each process the study was divided into three levels, i.e., adsorption of dye onto the substratum, phytoremediation within the CW and then bioremediation along with the previous two processes in the augmented CW. The adsorption process was helpful in removing 50% dye in presence of rice husk while 80% in presence of rice husk biocahr. Augmentation of microorganisms in CW systems has improved dye removal efficiency to 90%. Similarly presence of microorganisms enhanced removal of total nitrogen (68% 0 and Total phosphorus (75%). A significant improvement in plant growth was also observed by measuring plant height, number of leaves and leave area. These findings suggest the use of agricultural waste as part of a CW substratum can provide enhanced removal of textile dyes.


Asunto(s)
Bacterias/metabolismo , Colorantes/metabolismo , Naftalenosulfonatos/metabolismo , Oryza/química , Polygonaceae/metabolismo , Contaminantes Químicos del Agua/metabolismo , Humedales , Adsorción , Agricultura , Biodegradación Ambiental , Grano Comestible/química , Manipulación de Alimentos , Residuos Industriales/análisis , Pakistán , Industria Textil , Aguas Residuales/análisis
10.
Bioresour Technol ; 129: 281-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23262001

RESUMEN

The objective of this work was to evaluate methanogenesis in relation to the changes in performance and microbial diversity of cellulose-fed microbial fuel cells (MFCs). Replicate MFCs were inoculated with a ruminal microbial consortium and operated under 20 (R20Ω) or 100 Ω (R100Ω) external resistances. During the first week of operation, 0.31 and 0.44 mmol l(-1) of methane were produced in the R20Ω and R100Ω MFCs, respectively. Methanogenesis was, however, suppressed to undetectable levels within 90 days of operation, accompanied with increased current production and improved coulombic efficiency. Suppressed methanogenesis coincided with changes in the concentrations of short chain fatty acids and a decrease in the microbial diversity. The results demonstrated that methanogenesis was active during the early stage of cellulose-fed MFCs but this activity declined over prolonged operation.


Asunto(s)
Biodiversidad , Fuentes de Energía Bioeléctrica/microbiología , Metano/metabolismo , Consorcios Microbianos/fisiología , Diseño de Equipo , Análisis de Falla de Equipo
11.
Bioresour Technol ; 102(1): 278-83, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20627719

RESUMEN

External resistance affects the performance of microbial fuel cells (MFCs) by controlling the flow of electrons from the anode to the cathode. The purpose of this study was to determine the effect of external resistance on bacterial diversity and metabolism in MFCs. Four external resistances (20, 249, 480, and 1000 Ω) were tested by operating parallel MFCs independently at constant circuit loads for 10 weeks. A maximum power density of 66 mW m(-2) was achieved by the 20 Ω MFCs, while the MFCs with 249, 480, and 1000 Ω external resistances produced 57.5, 27, and 47 mW m(-2), respectively. Denaturing gradient gel electrophoresis analysis of partial 16S rRNA genes showed clear differences between the planktonic and anode-attached populations at various external resistances. Concentrations of short chain fatty acids were higher in MFCs with larger circuit loads, suggesting that fermentative metabolism dominated over anaerobic respiration using the anode as the final electron acceptor.


Asunto(s)
Bacterias/metabolismo , Fuentes de Energía Bioeléctrica/microbiología , Celulosa/metabolismo , Variación Genética , Electroforesis en Gel de Gradiente Desnaturalizante/métodos , Impedancia Eléctrica , Electricidad , Electrodos/microbiología , Ácidos Grasos Volátiles/análisis , Plancton/genética , Plancton/metabolismo , ARN Ribosómico 16S/análisis , ARN Ribosómico 16S/genética , Factores de Tiempo
12.
Biotechnol Bioeng ; 97(6): 1398-407, 2007 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-17274068

RESUMEN

In microbial fuel cells (MFCs) bacteria generate electricity by mediating the oxidation of organic compounds and transferring the resulting electrons to an anode electrode. The objective of this study was to test the possibility of generating electricity with rumen microorganisms as biocatalysts and cellulose as the electron donor in two-compartment MFCs. The anode and cathode chambers were separated by a proton exchange membrane and graphite plates were used as electrodes. The medium in the anode chamber was inoculated with rumen microorganisms, and the catholyte in the cathode compartment was ferricyanide solution. Maximum power density reached 55 mW/m(2) (1.5 mA, 313 mV) with cellulose as the electron donor. Cellulose hydrolysis and electrode reduction were shown to support the production of current. The electrical current was sustained for over 2 months with periodic cellulose addition. Clarified rumen fluid and a soluble carbohydrate mixture, serving as the electron donors, could also sustain power output. Denaturing gradient gel electrophoresis (DGGE) of PCR amplified 16S rRNA genes revealed that the microbial communities differed when different substrates were used in the MFCs. The anode-attached and the suspended consortia were shown to be different within the same MFC. Cloning and sequencing analysis of 16S rRNA genes indicated that the most predominant bacteria in the anode-attached consortia were related to Clostridium spp., while Comamonas spp. abounded in the suspended consortia. The results demonstrated that electricity can be generated from cellulose by exploiting rumen microorganisms as biocatalysts, but both technical and biological optimization is needed to maximize power output.


Asunto(s)
Fuentes de Energía Bioeléctrica , Celulosa/metabolismo , Clostridium/fisiología , Comamonas/fisiología , Electricidad , Electroquímica/instrumentación , Rumen/microbiología , Animales , Bovinos , Electroquímica/métodos , Diseño de Equipo , Análisis de Falla de Equipo
13.
J Antimicrob Chemother ; 57(4): 666-72, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16464890

RESUMEN

OBJECTIVES: To describe the distribution of trimethoprim-sulfamethoxazole resistance genes and the role of horizontal gene transfer and clonal expansion in recent increases of antibiotic resistance rates among uropathogenic Escherichia coli in Europe and Canada. METHODS: We identified antibiotic resistance alleles sul1, sul2, sul3 and dfr along with type 1 and type 2 integrons among 350 uropathogenic E. coli isolates from a cross-sectional study of acute, uncomplicated, community-acquired urinary tract infections in 16 western European countries and Canada (ECOSENS). RESULTS: Trimethoprim resistance gene distributions showed no regional dependency (P = 0.84). The most common trimethoprim resistance gene was dfrA1, which occurred in 37.9% of dfr containing isolates. Similarly, the sulfamethoxazole resistance gene distributions did not vary significantly by region (P = 0.20). sul2, the most common sulfamethoxazole resistance gene, was found in 77.9% of sulfamethoxazole-resistant isolates. The distribution of type 1 and type 2 integrons varied slightly by region (P = 0.04) with type 1 integrons being the more common (85.9%). We observed 34 combinations of the sul genes, dfr genes and integron types; the most common combinations were broadly disseminated across every region examined. CONCLUSIONS: Horizontal gene transfer plays a larger role than clonal expansion in the increase of trimethoprim-sulfamethoxazole resistance levels in Europe and Canada.


Asunto(s)
Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Transferencia de Gen Horizontal , Sulfametoxazol/farmacología , Combinación Trimetoprim y Sulfametoxazol/farmacología , Antibacterianos/farmacología , Canadá/epidemiología , Farmacorresistencia Bacteriana/genética , Escherichia coli/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Europa (Continente)/epidemiología , Humanos , Integrones , Pruebas de Sensibilidad Microbiana , Resistencia al Trimetoprim , Infecciones Urinarias/epidemiología , Infecciones Urinarias/microbiología
14.
Clin Infect Dis ; 40(8): 1101-7, 2005 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-15791508

RESUMEN

BACKGROUND: Antibiotic resistance is increasingly complicating the management of urinary tract infection. We investigated the extent to which a group of Escherichia coli called clonal group A (CGA), which is associated with resistance to trimethoprim-sulfamethoxazole (TMP-SMZ), accounted for TMP-SMZ resistance among a prospectively collected set of uropathogenic and rectal E. coli isolates from a university population in Michigan. METHODS: Resistant and susceptible uropathogenic E. coli isolates (45 each) and 79 randomly selected rectal E. coli isolates were evaluated for CGA status by use of 2 definitions of this group-- the enterobacterial repetitive intergenic consensus sequence 2 (ERIC2)-polymerase chain reaction (PCR) pattern A fingerprint and the C288T single nucleotide polymorphism (SNP) in the fumC gene. We compared virulence gene profiles and molecular mechanisms of resistance to TMP-SMZ between isolates classified as CGA by both approaches to better characterize the relationship between isolates. RESULTS: Of the 45 isolates that exhibited ERIC2-PCR pattern A, one-half (23 of 45) were resistant to TMP-SMZ, and 16 contained the C288T SNP. The pattern A isolates were diverse, exhibiting multiple mechanisms of resistance to TMP-SMZ and various combinations of virulence factors. C288T SNP isolates showed less variation, with 15 of 16 resistant to TMP-SMZ and a 1.8-kb class I integron bearing the dfrA17 gene present in 14 of 15 resistant isolates. Twelve of 16 exhibited the same combination of virulence genes. Pulsed-field gel electrophoresis patterns for these 12 isolates were unique. CONCLUSION: CGA, as defined by the fumC C288T SNP, appears to be distantly clonal but is not an outbreak-related group. The widespread group has likely evolved through lateral transfer of genes conferring virulence and antibiotic resistance.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple , Escherichia coli/clasificación , Escherichia coli/efectos de los fármacos , Combinación Trimetoprim y Sulfametoxazol/farmacología , Infecciones Urinarias/microbiología , Adolescente , Adulto , Dermatoglifia del ADN , Escherichia coli/genética , Escherichia coli/patogenicidad , Femenino , Humanos , Infecciones Urinarias/tratamiento farmacológico , Virulencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA