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1.
Water Environ Res ; 96(3): e11011, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38477462

RESUMEN

The current study focuses on the degradation of Procion brilliant yellow H-E6G, an azo dye, using ultrasonic and hydrodynamic cavitation (HC), evaluating the impact of various parameters on the extent of degradation. The use of only ultrasound showed less oxidation capacity as indicated by only 19.1% degradation at an optimized power of 140 W, pH of 2.5, temperature of 40°C, and initial dye concentration of 15 ppm. The effectiveness of hybrid approaches involving US + H2 O2 , US + Fenton, and US + H2 O2 + potassium persulfate (KPS) was subsequently evaluated under optimized conditions. A notable enhancement in decolorization extent was observed for combined operations, including US + H2 O2 , US + Fenton, and US + H2 O2 + KPS (dual oxidant scheme) with the actual decolorization extents as 80.6%, 85%, and 92.2% respectively. An optimized scheme of US + H2 O2 + KPS was also utilized to decolorize the dye at a pilot scale using a US flow cell and also an HC reactor that yielded 91.8% and 88% reductions in initial concentration. The dye decolorization was elucidated to follow first-order kinetics for all the individual and combination approaches. The obtained values of the rate constants were also utilized for the evaluation of the synergistic index. A toxicity analysis was also performed on the dye, both before and following treatment, utilizing two bacterial strains. A comparative analysis of various treatment approaches has been presented focusing on factors such as cavitational yield, operational expenses, and energy requirements. The study elucidated that the combination of US + H2 O2 + KPS effectively removes Procion brilliant yellow H-E6G giving 92.2% as the maximum degradation at an operating cost of 0.1862 $/L. PRACTITIONER POINTS: First depiction of cavitative degradation of Procion brilliant yellow H-E6G Optimizing the equipment operating parameters and chemical oxidants Demonstration of optimized treatment scheme at pilot scale Evaluation of various approaches based on synergy and costs of treatment US + H2 O2  + KPS is the best approach for dye degradation.


Asunto(s)
Compuestos Azo , Bencenosulfonatos , Peróxido de Hidrógeno , Oxidantes , Hidrodinámica , Ultrasonido
2.
J Environ Manage ; 350: 119642, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38016239

RESUMEN

The complexity of wastewater matrix poses a challenge for conventional processes especially due to the presence of refractory compounds such as dyes. The present work focuses on utilizing ultrasound-induced cavitation in conjunction with different oxidants such as hydrogen peroxide, Fenton's reagent and potassium persulfate to treat Procion Brilliant Purple H-3R dye containing wastewater. The impact of various operating parameters as pH, frequency, and power on degradation levels has been studied with the aim of optimizing degradation. The optimal conditions for the degradation of Procion Brilliant Purple H-3R were determined as pH of 12, frequency of 22 kHz, and power of 250 W, resulting in a maximum degradation of 70.25%. Combination of a cavitation reactor with hydrogen peroxide, Fenton reagent, and KPS was then applied at optimized conditions, which confirmed a notable enhancement in degradation compared to the only ultrasound based process. Specifically, the degradation extent was 95.99% for combination with H2O2 at 0.5 g/L loading, 99.79% for combination with Fenton at H2O2/Fe2+ ratio of 50:1, and 99.05% for combination with KPS at loading of 0.75 g/L. The kinetic rate constant for the combined approach of US + Fenton was also maximum at 7.47 × 10-1 L mg-1 min-1. Toxicity analysis was conducted on two bacterial strains, Escherichia coli and Staphylococcus aureus, using the wastewater in native form and after treatment. The various processes were evaluated in terms of the cavitational yield and overall treatment cost and it was determined that US + Fenton process is the most efficient treatment method for fully degrading Procion Brilliant Purple H-3R, particularly at larger scales of operation and cost efficiently as demonstrated in the work.


Asunto(s)
Peróxido de Hidrógeno , Aguas Residuales , Peróxido de Hidrógeno/química , Oxidación-Reducción , Oxidantes , Colorantes
3.
Vector Borne Zoonotic Dis ; 19(9): 647-651, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30835649

RESUMEN

Murine typhus is a flea-borne typhus group rickettsiosis caused by Rickettsia typhi. Once a prevalent disease in the United States, the use of dichlorodiphenyltrichloroethane in the 1940s broke the classic rat-rat flea cycle of transmission, and the remaining endemic foci are now believed to be associated with opossums and the cat flea (Ctenocephalides felis). In Galveston, Texas murine typhus has re-emerged as a cause of febrile illness, and 7% of fleas collected from opossums are infected with R. typhi. In this study, we sought to explore the prevalence of rickettsiae associated with fleas on cats, as these animals have been speculated to play a role in the epidemiology of murine typhus. Fleas were collected from feral cats entering a local veterinary clinic as part of a trap, spay, neuter, and release program. Fleas were identified and subjected to analysis by PCR and sequencing. An estimation of the minimum infection rate (MIR) of pooled samples was performed. Three hundred fourteen fleas (all C. felis) were collected from 24 cats. Sequences for the outer membrane protein B gene revealed R. typhi in one pool (MIR 0.3%), Rickettsia felis in four pools (MIR 1.3%), Rickettsia asembonensis in one pool (MIR 0.3%), and "Candidatus R. senegalensis" in six pools (MIR 2.0%). Results were confirmed by sequencing portions of the rickettsial citrate synthase and 17-kD protein gene. In this study, the presence of R. typhi in fleas from cats suggests that in Galveston, there exists a small but measurable risk to humans who come into contact with flea-infested cats. Despite this, we believe that the low prevalence from cat-collected fleas, compared with that previously detected from opossums, makes cats less likely to play a role in the maintenance of R. typhi in this region. The significance of other identified flea-borne rickettsiae is yet to be elucidated.


Asunto(s)
Enfermedades de los Gatos/parasitología , Infestaciones por Pulgas/veterinaria , Rickettsia/aislamiento & purificación , Siphonaptera/microbiología , Animales , Enfermedades de los Gatos/epidemiología , Gatos , Femenino , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/parasitología , Masculino , Texas/epidemiología
4.
Am J Trop Med Hyg ; 98(6): 1594-1598, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29637877

RESUMEN

Murine typhus, caused by Rickettsia typhi, is an undifferentiated febrile illness with no available rapid and sensitive diagnostic assay for use during early disease. We aimed to compare the health-care charges in those diagnosed with murine typhus to those with influenza, a febrile illness with an available rapid diagnostic test. A comparison of health-care-associated charges at the University of Texas Medical Branch at Galveston demonstrated a median of $817 for influenza versus $16,760 for murine typhus (P < 0.0001). Median laboratory ($184 versus $3,254 [P < 0.0001]) and imaging charges ($0 versus $514 [P < 0.0001]) were also higher in those with murine typhus. Those receiving at least one imaging study during their illness were greater in the murine typhus group (91.3% versus 20.3%) (P < 0.0001). The median time needed to establish a confirmed or presumptive diagnosis was 2 days for influenza compared with 9 days for murine typhus (P < 0.0001). The median number of health-care encounters was greater for those with murine typhus (2 versus 1) (P < 0.0001). Eleven patients (15.9%) with influenza were hospitalized as a result of their illness compared with 16 (69.6%) with murine typhus (P < 0.0001). The estimated mortality based on disease severity at presentation by Acute Physiology and Chronic Health Evaluation II scoring was similar in the two groups-both had a median 4% mortality risk (P = 0.0893). These results highlight the need for improved clinical recognition and diagnostics for acute rickettsioses such as murine typhus.


Asunto(s)
Tifus Endémico Transmitido por Pulgas/diagnóstico , Tifus Endémico Transmitido por Pulgas/economía , APACHE , Enfermedad Aguda , Adulto , Anciano , Atención Ambulatoria/economía , Atención Ambulatoria/estadística & datos numéricos , Animales , Estudios de Casos y Controles , Estudios de Cohortes , Honorarios y Precios/estadística & datos numéricos , Humanos , Persona de Mediana Edad , Ratas , Estudios Retrospectivos , Texas/epidemiología , Factores de Tiempo , Tifus Endémico Transmitido por Pulgas/epidemiología , Tifus Endémico Transmitido por Pulgas/transmisión , Adulto Joven
5.
Emerg Infect Dis ; 21(3): 484-6, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25695758

RESUMEN

Twelve patients with murine typhus were identified in Galveston, Texas, USA, in 2013. An isolate from 1 patient was confirmed to be Rickettsia typhi. Reemergence of murine typhus in Galveston emphasizes the importance of vector control and awareness of this disease by physicians and public health officials.


Asunto(s)
Enfermedades Transmisibles Emergentes/epidemiología , Tifus Endémico Transmitido por Pulgas/epidemiología , Anciano , Anciano de 80 o más Años , Animales , Enfermedades Transmisibles Emergentes/transmisión , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tipificación Molecular , Vigilancia de la Población , Rickettsia typhi/clasificación , Rickettsia typhi/genética , Serotipificación , Texas/epidemiología , Tifus Endémico Transmitido por Pulgas/transmisión
6.
Mymensingh Med J ; 23(3): 480-4, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25178599

RESUMEN

Early onset of hyperglycemia is common among low birth weight neonates. Increased risk for death and major morbidities has been observed among hyperglycemic low birth weight infants. This prospective observational study was done to find out hyperglycemia as a predictor of increased morbidity and mortality in the low birth weight sick newborn and was conducted among the hospitalized newborn of Special Care Baby Unit (SCABU), BIRDEM hospital, Dhaka, Bangladesh from July 2009 to December 2009. A total of 198 LBW neonates were included in this study. One third (30.8%) LBW neonates were found hyperglycemic. The mean gestational age was 33.2±3.6 weeks and mean birth weight was 1535.8±780gm in the hyperglycemic neonates. In this study, highest prevalence of hyperglycemia was observed in birth weight <1000gm (38.46%) and in gestational age ≤28 weeks (46.15%). Apnoea, confirmed sepsis and suspected sepsis, confirmed necrotizing enterocollitis (NEC) and neonatal jaundice showed statistically significant association with hyperglycemia than that of non hyperglycemic group. Mortality of neonates in hyperglycemic group was higher (31.15%) than that of non hyperglycemic neonates (10.22%) and the difference in mortality between two groups were found statistically significant (p<0.002). From this study it can be concluded that hyperglycemia in early neonatal period is related to increased morbidity and mortality in low birth weight newborn.


Asunto(s)
Hiperglucemia/mortalidad , Mortalidad Infantil , Recién Nacido de Bajo Peso , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Morbilidad , Estudios Prospectivos
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