Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Hazard Mater ; 453: 131446, 2023 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-37088025

RESUMEN

Bis (2-chloro-1-methylethyl) ether (DCIP), one U.S. Environmental Protection Agency priority pollutant, could pose health and/or odor risk in water environment. In this study, odor characteristics, occurrence and source of DCIP in drinking waters of China were investigated based on sensory analysis and a nation-wide investigation covering 140 drinking water treatment plants. Then multi-risk integrated health and aesthetic aspects through oral and inhalation (showering) exposure by drinking water were first estimated. Sensory evaluation showed DCIP exhibited "solvent-like" odor with thresholds of 34.8 ng/L in air and 142.0 ng/L in water. DCIP was detected at comparable concentrations in raw and finished waters (<1280 ng/L) and was by-product from industrial production of epichlorohydrin/propylene oxide. Lifetime Average Daily Dose through oral exposure was 0-36.65 ng/day/kg, corresponding to odor activity values of 0-8.4 and hazard quotients of far < 1, indicating drinking tap water might cause odor issues rather than significant health hazard. The proportion of sensitive population to DCIP's odor was 6.1%. In contrast, residents rarely detect DCIP's odor by inhalation. The presence in drinking water as industrial by-product, poor removal using conventional water treatment and potential to be T&O issues, indicates urgent demand for pollutant source control to protect DCIP from entering source waters.


Asunto(s)
Agua Potable , Contaminantes Ambientales , Contaminantes Químicos del Agua , Agua Potable/análisis , Éter/análisis , Solventes , Contaminantes Químicos del Agua/análisis , Éteres , Éteres de Etila , Contaminantes Ambientales/análisis , Medición de Riesgo , China , Monitoreo del Ambiente
2.
Arch Microbiol ; 204(8): 531, 2022 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-35904606

RESUMEN

There is an urgent need to develop natural antimicrobials for the control of rapidly mutating drug-resistant bacteria and poultry viruses. Five extracts were prepared using diethyl ether, ethyl acetate, methanol, 1-butanol and n-hexane from abdominal fats of Varanus griseus locally known as Indian desert monitor. Antibacterial, antioxidant and antiviral activities from oil extracts were done through disc diffusion method, stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay and in ovo antiviral assay, respectively. The gas chromatography mass spectrometry (GC-MS) analyses were used to determine principal active compounds and chemical profile of each oil extract. n-Hexane extract showed clear zones of inhibition (ZOI) against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae (12 ± 0.5 mm, 9 ± 0.5 mm, and 9 ± 0.5 mm) while diethyl ether extract exhibited significant antibacterial activity (11 ± 0.5 mm) against Proteus vulgaris only. In case of drug-resistant strains, methanol extract was active (6 ± 0.5 mm) against Staphylococcus aureus, whereas n-hexane extract has shown ZOI 11 ± 0.5 mm against P. aeruginosa. Range of percentage scavenging activity of V. griseus oil extracts from DPPH free radical assay was 34.9-70.7%. For antiviral potential, growth of new castle disease virus (NDV) was effectively inhibited by all five extracts (HA titer = 0-4). The highest antiviral activity against avian influenza virus (H9N2) was observed from methanol, diethyl ether and 1-Butanol oil extracts with HA titers of 2, 2 and 0, respectively. Methanol, diethyl ether, 1-butanol and n-hexane oil extracts produced best hemagglutination assay (HA) titer values (0, 0, 4 and 0) against infectious bronchitis virus (IBV). Ethyl acetate and 1-Butanol extract exhibited good antiviral potential against infectious bursal disease virus (IBDV) with indirect hemagglutination assay (IHA) titers of 8 and 4, respectively. Main classes of identified compounds through gas chromatography were aldehydes, fatty acids, phenols and esters. GC-MS identified 11 bioactive compounds in V. griseus oil extracts. It is summarized that V. griseus oil has strong antioxidant activity and good antimicrobial potential because of its bioactive compounds.


Asunto(s)
Antiinfecciosos , Subtipo H9N2 del Virus de la Influenza A , 1-Butanol/análisis , Animales , Antibacterianos/química , Antiinfecciosos/farmacología , Antioxidantes/análisis , Antivirales/farmacología , Éter/análisis , Radicales Libres/análisis , Cromatografía de Gases y Espectrometría de Masas , Metanol , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/química , Extractos Vegetales/farmacología
3.
J Anim Sci ; 100(9)2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35894938

RESUMEN

Previous research demonstrated that a fixed value of 0.2433 (SE = 0.0134) Mcal of CH4/kg of dry matter intake (DMI) could be used to predict CH4 production with accuracy and precision on par with similar equations in the literature. Slope bias was substantially less for the fixed-coefficient equation than noted for the other DMI- or gross energy intake (GEI)-based equations, but mean bias was substantially greater, presumably reflecting the failure of the fixed-coefficient approach to account for dietary factors that affect CH4 production. In this article, we report on the use of the dietary ratio of concentrations of starch to neutral detergent fiber (NDF) and dietary ether extract (EE) concentration to improve the accuracy and precision of the fixed-coefficient equation. The same development data set used to create the fixed-coefficient equation was used in the present study, which included 134 treatment means from 34 respiration calorimetry studies. Based on stepwise regression with dietary NDF, starch, crude protein, EE, and the starch:NDF ratio as possible dependent variables, the starch:NDF ratio and EE were the only dietary variables selected (P ≤ 0.15). The study-adjusted relationship with the starch:NDF ratio (r2 = 0.673; root mean square error [RMSE] = 0.0327) was: Mcal of CH4/kg of DMI = 0.2883 - 0.03474 × starch:NDF; whereas the relationship with a model that included both starch:NDF ratio and dietary EE (r2 = 0.738; RMSE = 0.0315) was: Mcal of CH4/kg of DMI = 0.3227 - 0.0334 × starch:NDF - 0.00868 × % EE. A previously published independent data set with 129 treatment means from 30 respiration calorimetry studies was used to evaluate these two equations, along with two additional equations in which g/d of CH4 was predicted directly from DMI, starch:NDF ratio, and/or dietary EE. The two Mcal of CH4/kg of DMI equations had superior fit statistics to the previously published 0.2433 Mcal of CH4/kg of DMI equation, with a substantial decrease in mean bias and improved concordance correlation coefficients. Moreover, the Mcal of CH4/kg of DMI equations resulted in improved fit relative to direct prediction of g/d of CH4 from DMI, the starch:NDF ratio, and % EE. Based on these results, further evaluation of the dietary ratio of starch-to-NDF concentrations and EE concentration to predict methane production per unit DMI in beef cattle is warranted.


Accurate and precise equations to predict enteric methane production are an important tool as the beef industry works to mitigate greenhouse gas emissions. We predicted the megacalories of methane per unit of dry matter intake using data from growing and finishing beef and dairy steers and heifers. The predicted value was then multiplied by dry matter intake to estimate methane production. The most important predictor variables were the ratio of dietary starch to neutral detergent fiber concentrations and dietary ether extract concentration. When tested with an independent data set, predicting methane per unit dry matter intake from the ratio of starch to neutral detergent fiber, with or without the addition of dietary ether extract as a predictor variable, yielded better fits to the independent data set than equations in which the daily production of methane was predicted directly from dry matter intake, the ratio of starch to neutral detergent fiber, and/or dietary ether extract. Predictions could potentially be further refined by adjusting the starch component of the ratio for degradability in the rumen (e.g., degree of gelatinization or processing) and the neutral detergent fiber content for the contributions from roughage vs. grains and grain byproducts.


Asunto(s)
Metano , Almidón , Animales , Bovinos , Detergentes/análisis , Dieta/veterinaria , Fibras de la Dieta/metabolismo , Éter/análisis , Femenino , Lactancia , Leche/metabolismo , Extractos Vegetales , Almidón/metabolismo
4.
J Agric Food Chem ; 61(38): 9063-6, 2013 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-24000828

RESUMEN

MS with GC-RI evidence was found for the presence of linden ether in cooked carrot (Daucus carota). Evaluation of the GC effluent from cooked carrot volatiles using aroma extract dilution analysis (AEDA) found linden ether with the highest flavor dilution (FD) factor. Others with 10-fold lower FD factors were ß-ionone, eugenol, the previously unidentified ß-damascenone, (E)-2-nonenal, octanal (+ myrcene), and heptanal. All other previously identified volatiles showed lower FD factors. Odor thresholds, concentrations, and odor activity values of previously identified compounds are reviewed. This indicated that at least 20 compounds occur in cooked carrots above their odor thresholds (in water). Compounds showing the highest odor activity values included ß-damascenone, (E)-2-nonenal, (E,E)-2,4-decadienal, ß-ionone, octanal, (E)-2-decenal, eugenol, and p-vinylguaiacol.


Asunto(s)
Daucus carota/química , Éter/análisis , Odorantes/análisis , Extractos Vegetales/análisis , Compuestos Orgánicos Volátiles/análisis , Culinaria
5.
J Agric Food Chem ; 56(13): 5021-5, 2008 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-18547046

RESUMEN

Volatile chemicals in a dichloromethane extract from a steam distillate of juniper berry fruit (Juniperus drupacea L.) and its two column chromatographic fractions (eluted with hexane and ethyl ether) were analyzed by gas chromatography/mass spectrometry. The major compounds in the dichloromethane extract were alpha-pinene (23.73%), thymol methyl ether (17.32%), and camphor (10.12%). A fraction eluted with hexane contained alpha-pinene (44.24%) as the major constituent. A fraction eluted with ethyl ether had thymol methyl ether (22.27%) and camphor (19.65%) as the main components. Three samples prepared from the distillate and two additional samples prepared by petroleum ether and ethanol extraction directly from juniper berry fruits exhibited clear antioxidant activities with dose response in both 1,2-diphenyl picrylhydrazyl and beta-carotene assays. All samples except the hexane fraction showed comparable activities to that of the synthetic antioxidant t-butyl hydroquinone at a level of 200 microg/mL in the two testing systems. The extracts of dichloromethane, petroleum ether, and ethanol exhibited appreciable antimicrobial activities against six microorganisms with minimum inhibitory concentrations ranging from 0.5 mg/mL (volatile extract against Candida albicans ) to 1.2 mg/mL (ethanol extract against Aspergillus niger ). The results of the present study suggest that this fruit could be a natural antioxidant supplement for foods and beverages.


Asunto(s)
Antiinfecciosos/química , Antioxidantes/química , Frutas/química , Juniperus/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Antiinfecciosos/farmacología , Antioxidantes/farmacología , Bacterias/efectos de los fármacos , Éter/análisis , Hongos/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Hexanos/análisis
6.
Arch Latinoam Nutr ; 28(4): 401-11, 1978 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-753185

RESUMEN

Hen's non-hatched eggs were processed by boiling for 30 minutes, milling in a meat grinder, and drying at 60 degrees C with continuous ventilation. The product contained 36% of protein, 27% of ether extract, 17% of ash, 10% of calcium, and 0.6% of phosphorus. The quality of the protein was comparable to that of a reference casein and of fresh egg meal, as determined by protein efficiency ratio and apparent net protein utilization.


Asunto(s)
Proteínas en la Dieta/análisis , Huevos/análisis , Aminoácidos/análisis , Animales , Peso Corporal , Calcio/análisis , Caseínas/normas , Éter/análisis , Valor Nutritivo , Fósforo/análisis , Ratas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA