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1.
Environ Res ; 232: 116350, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37290619

RESUMEN

The performance of a moving bed biofilm reactor (MBBR) depends largely on the type of biofilm carrier used. However, how different carriers affect the nitrification process, particularly when treating anaerobic digestion effluents, is not completely understood. This study aimed to evaluate the nitrification performance of two distinct biocarriers in MBBRs over a 140-d operation period, with a gradually decreasing hydraulic retention time (HRT) from 20 to 10 d. Reactor 1 (R1) was filled with fiber balls, whereas a Mutag Biochip was used for reactor 2 (R2). At an HRT of 20 d, the ammonia removal efficiency of both reactors was >95%. However, as the HRT was reduced, the ammonia removal efficiency of R1 gradually declined, ultimately dropping to 65% at a 10-d HRT. In contrast, the ammonia removal efficiency of R2 consistently exceeding 99% throughout the long-term operation. R1 exhibited partial nitrification, whereas R2 exhibited complete nitrification. Analysis of microbial communities showed that the abundance and diversity of bacterial communities, particularly nitrifying bacteria such as Hyphomicrobium sp. And Nitrosomonas sp., in R2 was higher than that in R1. In conclusion, the choice of biocarrier significantly impact the abundance and diversity of microbial communities in MBBR systems. Therefore, these factors should be closely monitored to ensure the efficient treatment of high-strength ammonia wastewater.


Asunto(s)
Microbiota , Nitrificación , Amoníaco , Biopelículas , Anaerobiosis , Reactores Biológicos/microbiología , Bacterias , Eliminación de Residuos Líquidos
2.
Environ Technol ; 42(3): 429-443, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31230556

RESUMEN

This study aimed to fully recover ammonia contained at a high concentration in anaerobic digestate of piggery wastewater (ADPW) by forming struvite. As magnesium and phosphorus sources, ferronickel slag (FNS) and K2HPO4 were used, respectively. By leaching 200 g L-1 of FNS with 3.0 M H2SO4, 10,309 mg L-1 of magnesium ions were extracted, and this acid-leachate of FNS (FNSL) also contained 5965 mg L-1 of total iron. In order to simultaneously remove both high concentrations of organic matters in ADPW and iron in FNSL which were known to hinder struvite formation, the mixture of ADPW and FNSL was added with H2O2 at the H2O2/Fe molar ratio of 0.75 and pH 4.0. After Fenton reaction, removal efficiencies of COD and total iron reached 77.36% and 99.89%, respectively. Then COD and an iron-reduced mixture of ADPW and FNSL were added with K2HPO4 satisfying Mg:N:P molar ratio of 1.2:1:1.15 at pH 9.5 to produce struvite for 1 h. From 1 L of ADPW (2.21 g NH3-N), 0.65 L of FNSL (4.65 g Mg2+), and 5.63 g of PO4 3-P, 46.7 g of precipitates were obtained. Overall removal efficiencies of magnesium, NH3-N, and phosphorus were 98.59%, 94.25%, and 99.97%, respectively. Obtained precipitates were analysed by using XRD, XRF, SEM-EDX and found to be struvite with impurities of potassium and metals. Additionally, the economic feasibility of FNS was assessed by estimating chemical costs of various magnesium sources.


Asunto(s)
Magnesio , Aguas Residuales , Anaerobiosis , Precipitación Química , Peróxido de Hidrógeno , Hierro , Níquel , Fosfatos , Fósforo , Estruvita
3.
J Infect Public Health ; 13(2): 244-252, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31806561

RESUMEN

BACKGROUND: The insulin-responsive glucose transporter 4 (GLUT4) plays prominent role in insulin-mediated facilitated glucose uptake into most of the cell types, majorly muscle, liver and adipose tissue. Impaired expression of GLUT4 has been linked to insulin resistance and diabetes. In adipocytes, excess lipids that are generated from liver and by de novo lipogenesis utilizing blood sugar, are stored. There are various nuclear factors, co-factors and signaling mechanisms that directly and indirectly regulate glucose transporter activity in adipocytes. Molecular mechanism behind the regulation of GLUT4 in adipocytes has not elucidated well. OBJECTIVE: Therefore, the present study focuses to explore the role of Liver X receptor- alpha (LXRα) on GLUT4 expression and the possible co-factors involved during in vitro adipogenesis and is assessed by modulating the activity of LXRα with specific agonist and antagonist ligands in 3T3L1 differentiated cells. RESULTS: The results demonstrate that SR 9238 (300nM), a strong inhibitor of LXRα, decreased the rate of adipogenesis through reduced lipid droplet formation in adipocytes without affecting the cell morphology. The FMOC-l-Leucine (FLL), a known partial ligand of PPARγ, enhanced the expression of LXRα. Thus, it can be concluded that LXRα has a significant role in adipocyte differentiation and FLL interaction promoted the transcription of LXRα, thereby promotes GLUT4 expression. The results in this study identified the role of LXRα in regulating the expression of GLUT4 through SRC1. CONCLUSION: The study is of much relevance in treatment of diabetes and also opens the possibility of identifying new drug molecules that target LXRα.


Asunto(s)
Adipocitos/metabolismo , Diabetes Mellitus/patología , Transportador de Glucosa de Tipo 4/metabolismo , Receptores X del Hígado/metabolismo , Células 3T3 , Adipogénesis , Animales , Diferenciación Celular , Diabetes Mellitus/metabolismo , Glucosa/metabolismo , Ratones , PPAR gamma/metabolismo
4.
ACS Omega ; 3(5): 5896-5902, 2018 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-30023928

RESUMEN

Here, we describe a rapid and efficient synthetic method of peptide-conjugated perylene diimide (P-PDI) using solid-phase peptide synthesis (SPPS). Due to severe insolubility of perylene dianhydride (PDA) as a starting material of perylene diimide (PDI), PDA was initially conjugated with amino acids to obtain soluble PDI derivatives. Target peptides were synthesized on a 2-chlorotrityl chloride resin using the SPPS method and then conjugated with the amino acid-appended PDI. Various conditions such as loading levels, reaction times and solvents were optimized for introducing the peptides to both sides of the amino acid-appended PDI. The final P-PDI was obtained with a maximum yield of 80% in 12 h. Its singlet oxygen-derived phototoxicity on cells was confirmed, which could be applicable to photodynamic therapy.

5.
ACS Omega ; 3(6): 5938-5945, 2018 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-30023933

RESUMEN

The topoisomerase I inhibitors SN-38 and camptothecin (CPT) have shown potent anticancer activity, but water insolubility and metabolic instability limits their clinical application. Utilizing carbon nanotubes as a protective shell for water-insoluble SN-38 and CPT while maintaining compatibility with aqueous media via a carboxylic acid-functionalized surface can thus be a strategy to overcome this limitation. Through hydrophobic-hydrophobic interactions, SN-38 and CPT were successfully encapsulated in carboxylic acid functionalized single-walled carbon nanotubes and dispersed in water. The resulting cell proliferation inhibition and drug distribution profile inside the cells suggest that these drug-encapsulated carbon nanotubes can serve as a promising delivery strategy for water-insoluble anticancer drugs.

6.
Environ Technol ; 39(7): 831-842, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28355496

RESUMEN

Anaerobic digestate of piggery wastewater (ADPW) contains high concentrations of ammonia and phosphorus with unbalanced molar ratio. Thus, ammonia remains at a high level even after phosphorus is completely removed through struvite formation. In this study, both ammonia and phosphorus were recovered by adding leachate of sewage sludge ash (SSA) into ADPW. It was demonstrated that 11,600 mg L-1 of total phosphorus and 7266.7 mg L-1 of [Formula: see text]-P were extracted from SSA by using sulfuric acid at the H2SO4/SSA mass ratio of 0.35. ADPW and the leachate of SSA were mixed at the volumetric ratio of 1:1.29, and then struvite was formed at the molar ratio of 1.2 (Mg2+):1.0 ([Formula: see text]-P):1.0 (NH3-N). Removal efficiencies of ammonia and phosphorus were 91.95% and 99.65%, respectively. The obtained struvite was analyzed by various methods and was found to meet the Korean fertilizer standards, except for copper.


Asunto(s)
Amoníaco/química , Aguas del Alcantarillado , Estruvita/química , Fosfatos , Fósforo , Aguas Residuales
7.
ACS Omega ; 3(4): 3901-3907, 2018 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-31458629

RESUMEN

Self-assembled nanostructures of tyrosine-rich peptides have a number of potential applications such as biocatalysts, organic conducting films, and ion-selective membranes. In modulating a self-assembly process of peptides, the interfacial force is an important factor for kinetic control. Here, we present the formation of large-sized and thickness-controllable nanofilms from the YYACAYY peptide sequence (Tyr-C7mer peptide) using Langmuir-Blodgett and Langmuir-Schaefer deposition methods. The Tyr-C7mer peptide showed typical surfactant-like properties, which were demonstrated via the isotherm test (surface pressure-area) by spreading the Tyr-C7mer peptide solution onto an air/water interface. Uniform and flat peptide nanofilms were successfully fabricated and characterized. The redox activity of densely packed tyrosine moieties on the peptide nanofilm was also evaluated by assembling silver nanoparticles on the nanofilm without requiring any additives.

8.
Nat Commun ; 5: 3665, 2014 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-24722220

RESUMEN

In two-dimensional interfacial assemblies, there is an interplay between molecular ordering and interface geometry, which determines the final morphology and order of entire systems. Here we present the interfacial phenomenon of spontaneous facet formation in a water droplet driven by designed peptide assembly. The identified peptides can flatten the rounded top of a hemispherical droplet into a plane by forming a macroscopic two-dimensional crystal structure. Such ordering is driven by the folding geometry of the peptide, interactions of tyrosine and crosslinked stabilization by cysteine. We discover the key sequence motifs and folding structures and study their sequence-specific assembly. The well-ordered, densely packed, redox-active tyrosine units in the YYACAYY (H-Tyr-Tyr-Ala-Cys-Ala-Tyr-Tyr-OH) film can trigger or enhance chemical/electrochemical reactions, and can potentially serve as a platform to fabricate a molecularly tunable, self-repairable, flat peptide or hybrid film.


Asunto(s)
Péptidos/química , Tirosina/química , Catálisis
9.
J Public Health Dent ; 72(1): 8-18, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22316105

RESUMEN

OBJECTIVES: Using an ecological conceptual model, this study examined the social context, structural, and behavioral factors within an immigrant community that contribute to increased access and use of oral health services by Latino children. The predictors of health service use at the level of the individual, the family, the provider, and the health service system were studied for their effects on the initiation of care, continuity of care, and frequency of planned visits. METHODS: In-depth face-to-face interviews were conducted with 320 Latino mothers regarding their use of oral health services for 4-8-year-old children [Mexican (n = 221), Puerto Rican (n = 69), and Central and South American (n = 30)]. Outcome measures of dental care utilization were early age at initiation of care, continuity of care, and frequency of planned dental visits. RESULTS: Regular planned dental visits were significantly related to the structural variables of household income and provider availability. The initiation of dental care was related to the mother's beliefs about the value of early preventive dental care. Mothers were more likely to continue care if they believed that the purpose was to keep the child's teeth healthy and had satisfactory communication with the dentist. CONCLUSIONS: Identifying the structural and behavioral factors that increase the likelihood of the use of oral health services can provide the basis for developing effective interventions specific to Latino children at the neighborhood level. The study findings can be also used for designing culturally appropriate oral health promotion programs and provider coordination of care.


Asunto(s)
Servicios de Salud Dental/estadística & datos numéricos , Accesibilidad a los Servicios de Salud , Hispánicos o Latinos/estadística & datos numéricos , Modelos Psicológicos , Aceptación de la Atención de Salud , Factores de Edad , Actitud Frente a la Salud , Chicago , Niño , Servicios de Salud del Niño/estadística & datos numéricos , Preescolar , Continuidad de la Atención al Paciente , Disparidades en Atención de Salud , Humanos , Renta , Seguro Odontológico , Entrevistas como Asunto , Análisis Multinivel , Análisis de Regresión , Factores Socioeconómicos , Encuestas y Cuestionarios
10.
J Prev Interv Community ; 37(4): 326-38, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19830627

RESUMEN

A social ecological framework integrated the six elements of the U.S. Department of Education Safe Schools/Healthy Students Initiative in High School District 201, Cook County, Illinois. Program components were organized across ecological levels (community-wide strategies, school-wide strategies, classrooms, and targeted individual students) along the developmental continuum from preschool to Grade 12. The goal of the community initiative was to promote positive youth development and social and emotional learning in all youth settings in the community, including the schools. There were demonstrated program effects for each of the components of the Initiative. The coalition and the program's activities have been sustained and have brought new interagency collaboration to more effectively serve Latino immigrant youth and their families.


Asunto(s)
Participación de la Comunidad , Instituciones Académicas/organización & administración , Medio Social , Violencia/prevención & control , Absentismo , Adolescente , Desarrollo del Adolescente , Niño , Desarrollo Infantil , Preescolar , Relaciones Comunidad-Institución , Conducta Cooperativa , Emigrantes e Inmigrantes , Femenino , Hispánicos o Latinos , Humanos , Masculino , Servicios de Salud Mental/organización & administración , Servicio Social/organización & administración
11.
J Health Care Poor Underserved ; 16(3): 431-43, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16086006

RESUMEN

Using a social ecological model, this study examined the influences of socio-demographic factors, mother's attitudes, financial barriers, and the health care delivery system on the use of dental services for 4-8 year-old Hispanic children. Initiating dental care during the preschool years was significantly related to the mothers' beliefs and her social network's beliefs in the value of preventive dental care. The mother was almost four times more likely to continue the care if she believed that dentist visits would keep the child's teeth healthy. Extended clinic hours in the evenings also increased the likelihood of the mother's return to the dentist to continue child's care. It was not the mother's attitudes but provider availability, dental insurance (including Medicaid) and family income that were related to frequency of planned visits. The study findings can be used in improving access to care and reducing barriers for low-income, urban Hispanic children.


Asunto(s)
Atención Odontológica/estadística & datos numéricos , Accesibilidad a los Servicios de Salud , Hispánicos o Latinos , Pobreza , Justicia Social , Chicago , Niño , Preescolar , Hispánicos o Latinos/psicología , Humanos
12.
J Health Care Poor Underserved ; 15(2): 170-82, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15253371

RESUMEN

This study examined social determinants affecting successful completion of the hepatitis B vaccination protocol among Korean American children in immigrant families. The effects of family characteristics, social support from support network, barriers to immunizations, and health beliefs concerning hepatitis B vaccination were examined using logistic regression analysis. Information support concerning parenting and child health (adjusted odds ratio [aOR] 2.55, 95% confidence interval [CI] 1.11-7.02) and perception that hepatitis B was a difficult disease from which to recover (aOR 2.11, 95% CI 1.20-3.72) appear to be the most important factors for vaccination compliance after adjusting for family income, mother's education level, and health insurance coverage. The burden of paying for immunizations (aOR 0.50, 95% CI 0.22-0.90) also had an impact on the vaccination status. These findings suggest that identifying the children at risk of undervaccination against hepatitis B maybe aided by focusing on these social determinants in addition to provider and sociodemographic characteristics.


Asunto(s)
Asiático/estadística & datos numéricos , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Vacunas contra Hepatitis B/administración & dosificación , Hepatitis B/etnología , Hepatitis B/prevención & control , Programas de Inmunización/estadística & datos numéricos , Aceptación de la Atención de Salud/etnología , Asiático/psicología , Chicago , Preescolar , Barreras de Comunicación , Emigración e Inmigración , Accesibilidad a los Servicios de Salud/economía , Humanos , Programas de Inmunización/economía , Corea (Geográfico)/etnología , Lenguaje , Pacientes no Asegurados , Pobreza
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