RESUMEN
The present study was conducted to evaluate the effect of Forsythiae Fructus aqueous extract (FAE) against cisplatin-induced emesis and to explore the antiemetic mechanism of FAE by focusing on NLRP3 inflammasome activation in a rat pica model. Our results showed that FAE significantly ameliorated cisplatin-induced acute and delayed pica in rats. Moreover, FAE improved the gastrointestinal histopathological injury and reduced the levels of serum ROS, IL-1ß, and IL-18 in cisplatin-treated rats. In addition, the expressions of NLRP3, ASC, caspase-1, and IL-1ß and the colocalization of the NLRP3 with ASC or caspase-1 in rat gastric antrum and ileum were also suppressed by FAE. Taken together, our findings indicate that FAE has a therapeutic effect against CINV, which may be related to its inhibition of the activation of NLRP3 inflammasome.
Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , Forsythia/química , Inflamasomas/efectos de los fármacos , Caolín/análisis , Proteína con Dominio Pirina 3 de la Familia NLR/antagonistas & inhibidores , Pica/inducido químicamente , Extractos Vegetales/farmacología , Animales , Antineoplásicos/aislamiento & purificación , Cisplatino/aislamiento & purificación , Extractos Vegetales/química , RatasRESUMEN
This study investigates the ability of spatial post-discharge mode functionalized kaolin to remove textile dye Reactive Red 2 from aqueous solution compared to that of the raw kaolinite. To fulfill the aim, the removal conditions, including plasma exposure time, processed mode (direct and post-discharge), pH of the aqueous dye solution, initial dye concentration and adsorbent dosage, were investigated. The changes that occur on clay surfaces before and after gliding arc plasma treatment were followed by Fourier transform infrared spectroscopy, scanning electron microscopy and nitrogen physisorption. The point of zero charge and the changes of the textural properties after gliding arc plasma treatment were also examined. The experimental data were analyzed using pseudo-first-order, pseudo-second-order and empirical Elovich models. The diffusion phenomenon was also studied. The results obtained indicate that spatial post-discharge pre-treatment of kaolin deeply influences the functional groups of some of its minerals as well as the morphology and texture of its particles. Consequently, at room temperature (â¼30 °C), the maximum adsorption capacities of natural raw kaolin clay were tripled after treatment with gliding arc plasma in spatial post-discharge mode and were almost doubled after the direct treatment mode.
Asunto(s)
Caolín/química , Modelos Químicos , Naftalenosulfonatos/química , Triazinas/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Caolín/análisis , Cinética , Naftalenosulfonatos/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica , Triazinas/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
The Talbragar Fish Bed is one of Australia's most important Jurassic deposits for freshwater fishes, land plants and aquatic and terrestrial insects. The site has yielded many well preserved fossils, which has led to the formal description of numerous new species and higher taxa. The excellent preservation of many fossils has allowed detailed anatomical studies, e.g. of the early teleost fish Cavenderichthys talbragarensis (Woodward, 1895). Here we report on the fluorescent characteristics and mineral composition of a range of Talbragar fossils. Most specimens fluoresce under ultraviolet, blue and green light. Elemental and mineralogical analyses revealed that the Talbragar fossils consist predominantly of quartz (SiO2), a mineral that is likely to account for the observed fluorescence, with trace kaolinite (Al2Si2O5(OH)4) in some of the fish fossils. Rock matrices are predominantly composed of quartz and goethite (FeO(OH)). Closer inspection of a plant leaf (Pentoxylon australicum White, 1981) establishes fluorescence as a useful tool for the visualisation of anatomical details that are difficult to see under normal light conditions.
Asunto(s)
Peces/anatomía & histología , Fósiles , Insectos/anatomía & histología , Hojas de la Planta/anatomía & histología , Plantas/anatomía & histología , Animales , Australia , Evolución Biológica , Historia Antigua , Insectos/química , Compuestos de Hierro/análisis , Compuestos de Hierro/química , Compuestos de Hierro/historia , Caolín/análisis , Caolín/química , Caolín/historia , Mediciones Luminiscentes , Metales Pesados/análisis , Metales Pesados/química , Metales Pesados/historia , Minerales/análisis , Minerales/química , Minerales/historia , Hojas de la Planta/química , Plantas/química , Cuarzo/análisis , Cuarzo/química , Cuarzo/historia , Espectrometría de FluorescenciaRESUMEN
Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (â¼50% removal; optimal pH: 6; optimal dosage: 4mg/L) and TYL (â¼60% removal; optimal pH: 7; optimal dosage: 7.5mg/L), due to π-π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (â¼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics' removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.
Asunto(s)
Aminoácidos/química , Antibacterianos/análisis , Quitosano/química , Sustancias Húmicas/análisis , Caolín/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Floculación , Modelos Teóricos , Tamaño de la PartículaRESUMEN
Tropical climate is rapidly changing, but the effects of these changes on the geosphere are unknown, despite a likelihood of climatically-induced changes on weathering and erosion. The lack of long, continuous paleo-records prevents an examination of terrestrial responses to climate change with sufficient detail to answer questions about how systems behaved in the past and may alter in the future. We use high-resolution records of pollen, clay mineralogy, and particle size from a drill core from Lake Malawi, southeast Africa, to examine atmosphere-biosphere-geosphere interactions during the last deglaciation (â¼ 18-9 ka), a period of dramatic temperature and hydrologic changes. The results demonstrate that climatic controls on Lake Malawi vegetation are critically important to weathering processes and erosion patterns during the deglaciation. At 18 ka, afromontane forests dominated but were progressively replaced by tropical seasonal forest, as summer rainfall increased. Despite indication of decreased rainfall, drought-intolerant forest persisted through the Younger Dryas (YD) resulting from a shorter dry season. Following the YD, an intensified summer monsoon and increased rainfall seasonality were coeval with forest decline and expansion of drought-tolerant miombo woodland. Clay minerals closely track the vegetation record, with high ratios of kaolinite to smectite (K/S) indicating heavy leaching when forest predominates, despite variable rainfall. In the early Holocene, when rainfall and temperature increased (effective moisture remained low), open woodlands expansion resulted in decreased K/S, suggesting a reduction in chemical weathering intensity. Terrigenous sediment mass accumulation rates also increased, suggesting critical linkages among open vegetation and erosion during intervals of enhanced summer rainfall. This study shows a strong, direct influence of vegetation composition on weathering intensity in the tropics. As climate change will likely impact this interplay between the biosphere and geosphere, tropical landscape change could lead to deleterious effects on soil and water quality in regions with little infrastructure for mitigation.
Asunto(s)
Silicatos de Aluminio/química , Cambio Climático/historia , Sedimentos Geológicos/química , Lagos , Fenómenos Fisiológicos de las Plantas , Polen/citología , Arcilla , Geografía , Historia Antigua , Caolín/análisis , Malaui , Tamaño de la Partícula , Lluvia , Silicatos/análisis , Especificidad de la Especie , Clima Tropical , Difracción de Rayos XRESUMEN
In this investigation, Raman spectroscopy with 1064 and 632.8 nm excitation was used to investigate real mineral samples of bauxite ore from mines of Northern Brazil, together with Raman mapping and X-rays diffraction. The obtained results show clearly that the use of microRaman spectroscopy is a powerful tool for the identification of all the minerals usually found in bauxites: gibbsite, kaolinite, goethite, hematite, anatase and quartz. Bulk samples can also be analysed, and FT-Raman is more adequate due to better signal-to-noise ratio and representativity, although not efficient for kaolinite. The identification of fingerprinting vibrations for all the minerals allows the acquisition of Raman-based chemical maps, potentially powerful tools for process mineralogy applied to bauxite ores.
Asunto(s)
Óxido de Aluminio/análisis , Minerales/análisis , Espectrometría Raman/métodos , Brasil , Compuestos Férricos/análisis , Compuestos de Hierro/análisis , Caolín/análisis , Cuarzo/análisis , Titanio/análisis , Difracción de Rayos XRESUMEN
In the wake of the 1989 Exxon Valdez oil spill, spatially and temporally spill-correlated biological effects consistent with polycyclic aromatic hydrocarbon (PAH) exposure were observed. Some works have proposed that confounding sources from local source rocks, prominently coals, are the provenance of the PAHs. Representative coal deposits along the southeast Alaskan coast (Kulthieth Formation) were sampled and fully characterized chemically and geologically. The coals have variable but high total organic carbon content technically classifying as coals and coaly shale, and highly varying PAH contents. Even for coals with high PAH content (approximately 4000 ppm total PAHs), a PAH-sensitive bacterial biosensor demonstrates nondetectable bioavailability as quantified, based on naphthalene as a test calibrant. These results are consistent with studies indicating that materials such as coals strongly diminish the bioavailability of hydrophobic organic compounds and support previous work suggesting that hydrocarbons associated with the regional background in northern Gulf of Alaska marine sediments are not appreciably bioavailable.
Asunto(s)
Petróleo , Hidrocarburos Policíclicos Aromáticos/análisis , Adsorción , Alaska , Técnicas Biosensibles , Carbono/química , Carbón Mineral , Exposición a Riesgos Ambientales , Contaminantes Ambientales/análisis , Sedimentos Geológicos/química , Proteínas Fluorescentes Verdes/química , Hidrocarburos/análisis , Hielo , Caolín/análisis , Naftalenos/análisis , Hidrocarburos Policíclicos Aromáticos/químicaRESUMEN
Time-resolved laser-induced fluorescence spectroscopy (TRLFS) was applied to study the U(VI) surface complexes on kaolinite in the presence and absence of humic acid (HA). Two uranyl surface species with fluorescence lifetimes of 5.9 +/- 1.4 and 42.5 +/- 3.4 micros and 4.4 +/- 1.2 and 30.9 +/- 7.2 micros were identified in the binary (U(VI)-kaolinite) and ternary system (U(VI)-HA-kaolinite), respectively. The fluorescence spectra of adsorbed uranyl surface species are described with six and five fluorescence emission bands in the binary and ternary system, respectively. The positions of peak maxima are shifted significantly to higher wavelengths compared to the free uranyl ion in perchlorate medium. HA has no influence on positions of the fluorescence emission bands. In the binary system, both surface species can be attributed to adsorbed bidentate mononuclear surface complexes, which differ in the number of water molecules in their coordination environment. In the ternary system, U(VI) prefers direct binding on kaolinite rather than via HA, but it is sorbed as a uranyl-humate complex. Consequently, the hydration shell of the U(VI) surface complexes is displaced with complexed HA, which is simultaneously distributed between kaolinite particles. Aluminol binding sites are assumed to control the sorption of U(VI) onto kaolinite.
Asunto(s)
Antidiarreicos/análisis , Sustancias Húmicas , Caolín/análisis , Contaminantes Radiactivos/análisis , Espectrometría de Fluorescencia/métodos , Uranio/análisis , Adsorción , Antidiarreicos/química , Cationes , Caolín/química , Rayos Láser , Percloratos/química , Contaminantes Radiactivos/química , Uranio/químicaRESUMEN
Natural radioactive materials are present in all geological rocks in varying amounts, they are easily mobilized in the environment, and can reach hazardous radiological levels under certain conditions, requiring precautions to be taken. The present study deals with 50 geological samples of local (Tushki and Kalabsha in upper Egypt) and imported (southeast Asia and Turkey) kaolin types. The samples were analyzed by gamma-ray spectroscopy using a HPGe detector. The activity concentrations of 232Th and 238U series and 40K and the contents (in ppm) are given. The radium equivalent activity varied from 187.8 to 10185.19 Bq/kg. 137Cs was found in a range of 0.23-8.5 Bq/kg, for the local samples. The kaolin in Tushki area was suitable for industrial use.
Asunto(s)
Caolín/análisis , Radioisótopos/análisis , Egipto , Sedimentos Geológicos/análisis , Radioisótopos de Potasio/análisis , Radiactividad , Espectrometría gamma , Torio/análisis , Uranio/análisisRESUMEN
Twenty five Chinese herbal medicinal prescriptions containing gypsum, kaolin, longgu, oyster shell and sodium sulfate were studied for the inhibitory activity of adenosine 3',5'-cyclic monophosphate phosphodiesterase. The inhibitory activity of 15 prescriptions without mineral drug was higher than that of each original prescription. On the contrary, four were lower and six were not recognized to be different. All 11 prescriptions containing gypsum with an exception increased the inhibitory activity by removing gypsum. The half prescriptions containing kaolin or sodium sulfate also increased the inhibitory activity by removing the drug.
Asunto(s)
3',5'-AMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , Medicamentos Herbarios Chinos/química , Sulfato de Calcio/análisis , Combinación de Medicamentos , Caolín/análisis , Minerales/análisis , Sulfatos/análisisRESUMEN
Fourier transform i.r. measurements of L-pyroglutamic acid dispersed in a matrix of a clay, silica or alumina have been obtained at various temperatures between 25 and 220 degrees C. The i.r. spectrum of L-pyroglutamic acid varies in a manner dependent upon the matrix material and shows considerable change as the temperature of the mixtures is increased. The differences in the spectrum at elevated temperatures are explained in terms of a chemical reaction between hydroxyl groups in the matrix and the carboxylic acid. The i.r. spectra of trimethylsilyl derivatives of L-pyroglutamic acid and aluminum pyroglutamate were also measured to assist the understanding of spectra and interpretation of the spectral changes dependent upon increasing temperature.