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1.
Anal Bioanal Chem ; 413(6): 1739-1747, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33462659

RESUMEN

Perovskite materials have attracted attention due to their excellent optical and electrical properties; however, their unsatisfactory stability limits their application in biochemical detection. In this paper, CsPbBr3 perovskite quantum dots were successfully encapsulated in poly(styrene/acrylamide) microspheres, using a swelling-shrinking method. The manufactured perovskite microspheres (PDPS composites) not only maintained strong photoluminescence (PL) stability but also demonstrated great water solubility. Additionally, a real-time pH monitoring platform was constructed based on the prepared PDPS composites and dopamine, and the system showed a good linear relationship in a pH range of 4-12. Furthermore, urea could be hydrolyzed to produce hydroxyl groups, thereby increasing the pH of the solution. Therefore, this system was then extended for urea and urease detection. As a result, the detection limits of urea and urease were recorded as 1.67 µM and 2.1 mU/mL, respectively. This development provides an interesting demonstration of the expanding list of applications of perovskite materials.


Asunto(s)
Compuestos de Calcio/análisis , Óxidos/análisis , Titanio/análisis , Urea/sangre , Urea/orina , Ureasa/sangre , Ureasa/orina , Agua/química , Técnicas Biosensibles/métodos , Ácidos Carboxílicos/química , Enzimas Inmovilizadas/química , Colorantes Fluorescentes , Concentración de Iones de Hidrógeno , Hidrólisis , Límite de Detección , Modelos Lineales , Microscopía Electrónica de Transmisión , Microesferas , Puntos Cuánticos , Solubilidad , Temperatura , Difracción de Rayos X
2.
Environ Geochem Health ; 43(5): 2065-2080, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33392897

RESUMEN

This paper attempts to evaluate the mineralogical and chemical composition of sedimentary limestone mine waste alongside its mineral carbonation potential. The limestone mine wastes were recovered as the waste materials after mining and crushing processes and were analyzed for mineral, major and trace metal elements. The major mineral composition discovered was calcite (CaCO3) and dolomite [CaMg(CO3)2], alongside other minerals such as bustamite [(Ca,Mn)SiO3] and akermanite (Ca2MgSi2O7). Calcium oxide constituted the greatest composition of major oxide components of between 72 and 82%. The presence of CaO facilitated the transformation of carbon dioxide into carbonate form, suggesting potential mineral carbonation of the mine waste material. Geochemical assessment indicated that mean metal(loid) concentrations were found in the order of Al > Fe > Sr > Pb > Mn > Zn > As > Cd > Cu > Ni > Cr > Co in which Cd, Pb and As exceeded some regulatory guideline values. Ecological risk assessment demonstrated that the mine wastes were majorly influenced by Cd as being classified having moderate risk. Geochemical indices depicted that Cd was moderately accumulated and highly enriched in some of the mine waste deposited areas. In conclusion, the limestone mine waste material has the potential for sequestering CO2; however, the presence of some trace metals could be another important aspect that needs to be considered. Therefore, it has been shown that limestone mine waste can be regarded as a valuable feedstock for mineral carbonation process. Despite this, the presence of metal(loid) elements should be of another concern to minimize potential ecological implication due to recovery of this waste material.


Asunto(s)
Carbonato de Calcio , Residuos Industriales/análisis , Minería , Carbonato de Calcio/análisis , Compuestos de Calcio/análisis , Compuestos de Calcio/química , Dióxido de Carbono/química , Carbonatos/análisis , Carbonatos/química , Monitoreo del Ambiente , Contaminación Ambiental , Magnesio/análisis , Malasia , Metales Pesados/análisis , Minerales/análisis , Óxidos/análisis , Óxidos/química , Oligoelementos/análisis
3.
Microb Ecol ; 81(2): 314-322, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32935184

RESUMEN

In this study, the joint use of high throughput sequencing, real-time quantitative PCR, and ammonia-oxidizing bacteria (AOB)-inhibiting allylthiourea was used to differentiate between the contributions of ammonia-oxidizing archaea (AOA) vs AOB to ammonia oxidation and ascertain how AOA and AOB responded to two widely used river remediation techniques (aeration and Ca(NO3)2 injection). Results showed that ammonia oxidation was largely attributed to ATU-sensitive AOB rather than AOA and Nitrosomonas was the predominant AOB-related genus (53.86%) in the malodorous river. The contribution of AOB to ammonia oxidation in the context of aeration and Ca(NO3)2 injection was 75.51 ± 2.77% and 60.19 ± 10.44%, respectively. The peak of AOB/AOA ratio and the marked increase of relative abundances of Nitrosomonas and Nitrosospira in aeration runs further demonstrated aeration favored the ammonia oxidation of AOB. Comparatively, Ca(NO3)2 injection could increase the ammonia oxidation contribution of AOA from 31.32 ± 6.06 to 39.81 ± 10.44% and was significantly correlated with Nitrosococcus of AOB (r = 0.796, p < 0.05), Candidatus_Nitrosopelagicus of AOA (r = 0.986, p < 0.01), and AOA Simpson diversity (r = - 0.791, p < 0.05). Moreover, Candidatus_Nitrosopelagicus was only present in Ca(NO3)2 runs. Taken together, Ca(NO3)2 was recognized as an important factor in mediating the growth and ecological niches of ammonia oxidizers.Graphical abstract.


Asunto(s)
Amoníaco/metabolismo , Archaea/metabolismo , Bacterias/metabolismo , Restauración y Remediación Ambiental/métodos , Sedimentos Geológicos/microbiología , Ríos/microbiología , Amoníaco/análisis , Archaea/clasificación , Archaea/genética , Archaea/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Compuestos de Calcio/análisis , Sedimentos Geológicos/química , Nitratos/análisis , Oxidación-Reducción , Oxígeno/análisis , Ríos/química , Especificidad de la Especie , Contaminantes Químicos del Agua/metabolismo
4.
Int J Occup Med Environ Health ; 33(6): 757-769, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-33051631

RESUMEN

Mineral wool is widely used for thermal and sound insulation. The subject of the study is to identify hazards for employees resulting from exposure to mineral wool, when it is used to insulate buildings, and to assess the risk arising from this exposure. When installing mineral wool insulation, respirable mineral fibers, dust, and volatile organic compounds may pose a hazard at workplaces. Based on the results of concentration measurements, it was assessed that the probability of adverse health effects related to the work of insulation installers, resulting from exposure to mineral wool fibers, is low, but for dust associated with exposure, an average health risk was estimated. An additional threat may be the sensitizing effect of substances used as binders and additives improving the utility properties of mineral wool, for example, phenol formaldehyde resins. The paper also contains some information on the labeling of mineral wool; this is very important because the label allows downstream users to recognize mineral wools, the composition and properties of which cause that they are not classified as carcinogens. Int J Occup Med Environ Health. 2020;33(6):757-69.


Asunto(s)
Compuestos de Calcio/efectos adversos , Materiales de Construcción/efectos adversos , Exposición Profesional/efectos adversos , Silicatos/efectos adversos , Compuestos de Calcio/análisis , Compuestos de Calcio/normas , Materiales de Construcción/análisis , Materiales de Construcción/normas , Polvo/análisis , Humanos , Fibras Minerales/efectos adversos , Fibras Minerales/análisis , Fibras Minerales/normas , Exposición Profesional/prevención & control , Exposición Profesional/normas , Etiquetado de Productos , Medición de Riesgo , Silicatos/análisis , Silicatos/normas , Compuestos Orgánicos Volátiles/efectos adversos , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/normas , Lugar de Trabajo
5.
Ecotoxicol Environ Saf ; 203: 111010, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32888587

RESUMEN

Manganese (Mn) toxicity is common in plants grown on very acid soils. However, some plants species that grow in this condition can take up high amounts of Mn and are referred to as hyperaccumulating species. In this study, we evaluated the capacity of Ilex paraguariensis to accumulate Mn and the effect of excessive concentrations on plant growth and nutrition. For this, a container experiment was conducted using soils from different parent materials (basalt and sandstone), with and without liming, and at six doses of applied Mn (0, 30, 90, 270, 540 and 1,080 mg kg-1). Clonal plants grown for 203 days were harvested to evaluate yield, and leaf tissue samples were evaluated for Mn and other elements. Without liming and with high Mn doses, leaf Mn concentrations reached 13,452 and 12,127 mg kg-1 in sandstone and basalt soils, respectively; concentrations in excess of 10,000 mg kg-1 are characteristic of hyperaccumulating plants. Liming reduced these values to 7203 and 8030 mg kg-1. More plant growth accompanied increased Mn leaf concentrations, with a growth reduction noted at the highest dose in unlimed soils. Elemental distribution showed Mn presence in the mesophyll, primarily in vascular bundles, without high Mn precipitates. Interveinal chlorosis of young leaves associated with high Mn concentration and lower Fe concentrations was observed, especially in sandstone soil without liming. However, the occurrence of this symptom was not associated with decreased plant growth.


Asunto(s)
Ácidos/farmacología , Ilex paraguariensis/metabolismo , Manganeso/metabolismo , Enfermedades de las Plantas/inducido químicamente , Contaminantes del Suelo/metabolismo , Ácidos/análisis , Compuestos de Calcio/análisis , Compuestos de Calcio/farmacología , Ilex paraguariensis/efectos de los fármacos , Ilex paraguariensis/crecimiento & desarrollo , Hierro/metabolismo , Manganeso/análisis , Manganeso/toxicidad , Óxidos/análisis , Óxidos/farmacología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Suelo/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
6.
Eur Endod J ; 5(2): 128-133, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32766523

RESUMEN

Objective: Initial setting time is one of the most important properties of calcium silicate cements (CSCs) such as white mineral trioxide aggregate (WMTA). This study aimed to evaluate the effect of two methods used to reduce the particle size of WMTA, mechanical activation and chemical synthesis. Methods: WMTA without bismuth oxide (WMTA-B) was provided and divided into four groups (n=5) including: WMTA-B, WMTA-B+10 min milling, WMTA-B+30 min milling, and sol-gel. In groups 2 and 3, the milling was performed by using tungsten carbide balls in a ratio 1:15 (w/w) and a vibration frequency of 30 Hz together with absolute ethanol. For the fourth group, polyethylene glycol (PEG), calcium acetate (Ca(C2H3O2)2), SiO2, and aluminum oxide (Al2O3) were used for the sol-gel process. After preparation, sample powders were mixed with distilled water and placed in cylindrical molds, covered with water-moistened gauze, and incubated at 37°C for 24 hours. The Vicat needle test analyzed the initial setting time. Data were analyzed by ANOVA and Tukey tests at a significance level of P<0.05. The correlation between particle size and setting time was determined. Results: Initial setting time of the sol-gel and WMTA-B+30 min milling was significantly lower than in the other two groups (P<0.05). A significant correlation was noticed between particle size and initial setting time (P<0.05). Conclusion: Sol-gel process introduces a promising alternative strategy for the reduction of initial setting time of CSC materials. While both methods increased surface area, mechanical activation was not as successful in reducing surface area and initial setting time as effectively as the sol-gel process.


Asunto(s)
Acetatos/análisis , Compuestos de Aluminio/análisis , Compuestos de Calcio/análisis , Óxidos/análisis , Materiales de Obturación del Conducto Radicular/química , Silicatos/análisis , Dióxido de Silicio/análisis , Combinación de Medicamentos , Humanos , Ensayo de Materiales , Tamaño de la Partícula
7.
Environ Sci Pollut Res Int ; 27(6): 6180-6192, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31865574

RESUMEN

More knowledge of the geochemical behavior of tungsten (W) and associated contamination risks is needed. Therefore, weathering of scheelite (CaWO4) and secondary sequestration and transport of W to groundwater in historical skarn tailings and surface water downstream of the tailings were studied. The tailings contained 920 mg/kg W, primarily in scheelite. Mineralogical and geochemical analyses were combined to elucidate the geochemical behavior of W in the tailings, and water samples were taken monthly during 2018 to monitor its mobility. In the tailings, a large peak of W was found at 1.5 m depth. There, 30 wt%. of W was present in easily reducible phases, indicating former scheelite weathering. Currently, W is being released from scheelite to water-soluble phases at 2.5 m depth. The release of WO42- is hypothetically attributed to anion exchange with CO32- released from calcite neutralizing acid produced from pyrrhotite oxidation in the upper tailings and transported downwards to pH conditions > 7. Higher concentrations of dissolved W were found in the groundwater and particulate W in downstream surface water than in reference water, but they were lower than current contamination thresholds. Tungsten showed correlations with hydrous ferric oxides (HFO) in both the tailings and surface water.


Asunto(s)
Compuestos de Calcio/análisis , Monitoreo del Ambiente , Contaminantes del Suelo/análisis , Compuestos de Tungsteno/análisis , Tungsteno , Minería , Modelos Químicos , Sulfuros , Suecia , Tiempo (Meteorología)
8.
J Food Sci ; 84(12): 3653-3663, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31750939

RESUMEN

This research aimed to evaluate the effect of different calcium compounds and their concentration on the viscoelastic parameters of flours and tortillas obtained with traditional and ecological nixtamalization. Specimens (tablets) of nixtamalized flours and tortillas (14% moisture) prepared with three different calcium sources and four concentrations were sintered using a die and a hydraulic press and were evaluated by stress-relaxation tests with a texturometer. Data collected from the stress-relaxation curve were fitted into a three-element generalized Maxwell model (r2 = 0.9999), allowing the detection of significant differences in the estimated viscoelastic parameters. When flours are processed into tortillas, the most notable change was the increase of +88.44% and +73.44%, respectively, in the summation of the elastic modulus, and the compressional viscosity in samples produced with CaCO3. On the contrary, tablets from samples with Ca(OH)2 presented a sharp diminishing (loss) in both of the evaluated viscoelastic parameters, accounting a decrease of -39.82% and -46.28% for the elastic modulus and compressional viscosity summations, respectively. Highly significant correlations were found among viscoelastic parameters when a slight proportional increase was observed in the specific elastic moduli, meaning that the energy was stored by each elastic element in the tablets, while the compressional viscosity coefficients varied as a function of time. Finally, it was found that the residual spring due to the pure elastic component (E0 ) stored energy during the entire test. PRACTICAL APPLICATION: There is no published information about a simple methodology for the evaluation of the viscoelastic properties of dry nixtamalized flours (powder) with a texturometer. The method proposed was sensitive and accurate, since it was capable of detecting differences among samples processed under distinct processing factors conditions. The study of viscoelastic properties of grain foods contributes to the construction of molecular theories occurring in their chemical compounds, which is strongly related to food texture. Those theories are handy to improve nutritional and textural properties of grain foods and are essential to powder handling, processing, and transportation, which allows the processing factors optimization.


Asunto(s)
Pan/análisis , Compuestos de Calcio/análisis , Harina/análisis , Elasticidad , Manipulación de Alimentos , Minerales/análisis , Comprimidos/química , Viscosidad , Zea mays/química
9.
PLoS One ; 14(10): e0223764, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31613923

RESUMEN

Soil pH is a critical soil quality index and controls soil microbial activities, soil nutrient availability, and plant roots growth and development. The current study aims to evaluate various pedotransfer functions for predicting soil pH using different geochemical indices (CaO, ratios of Al2O3, Fe2O3, TiO2, SiO2, MgO, and K2O to CaO) in forest soils. Various models including empirical functions (quadratic, cubic, sigmoid, logarithmic) and artificial neural network with these geochemical indices were assessed by independent testing set. Mean bias error (MBE), root mean square error (RMSE), mean absolute percentage error (MAPE), mean absolute error (MAE), coefficient of determination (R2), t-statistics (t-stat), and Akaike's Information Criterion (AIC) were applied to evaluate the model performances. Additionally, a new indicator (global performance indictor, GPI) was originally introduced in this study and was used to rank these models. According to GPI, the sigmoid functions and ANNs performed better than others. On average, they could explain above 70% of the variability in soil pH. Both model structure and dataset shape impact on model performance. The best input was CaO for ANNs, sigmoid, and logarithmic functions. The ratios of K2O to CaO and Al2O3 to CaO were the best inputs for quadratic and cubic equations, respectively.


Asunto(s)
Compuestos de Calcio/análisis , Monitoreo del Ambiente/métodos , Óxidos/análisis , Suelo/química , Algoritmos , China , Bosques , Concentración de Iones de Hidrógeno
10.
Environ Sci Pollut Res Int ; 26(20): 20248-20263, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31098908

RESUMEN

Currently, activated coke is widely used in the removal of multiple pollutants from industrial flue gas. In this paper, a series of novel FexLayOz/AC catalysts was prepared by the incipient wetness impregnation for NH3-SCR denitrification reaction. The introduction of Fe-La bimetal oxides significantly improved the denitrification performance of activated coke at mid-high temperature, and 4% Fe0.3La0.7O1.5/AC exhibited a superior NOx conversion efficiency of 90.1% at 400 °C. The catalysts were further characterized by BET, SEM, XRD, Raman, EPR, XPS, FTIR, NH3-TPD, H2-TPR, et al., whose results showed that the perovskite-type oxide of LaFeO3 and oxygen vacancies were produced on the catalysts' surfaces during roasting. Fe-La doping enhanced the amount of acid sites (mainly Lewis and other stronger acid sites) and the content of multifarious oxygen species, which were beneficial for NOx removal at mid-high temperature. Moreover, it was investigated that the effect of released CO from activated coke at mid-high temperature on the NOx removal through the lifetime test, in which it was found that a large amount of CO produced by pyrolysis of activated coke could promote the NOx removal, and long-term escaping of CO on the activated coke carrier did not have a significant negative impact on catalytic performance. The results of the TG-IR test showed that volatile matter is released from the activated coke while TG results showed that the weight loss rate of 4% Fe0.3La0.7O1.5/AC only was 0.0015~0.007%/min at 300-400 °C. Hence, 4% Fe0.3La0.7O1.5/AC had excellent thermal stability and denitrification performance to be continuously used at mid-high temperature. Finally, the mechanisms were proposed on the basis of experiments and characterization results.


Asunto(s)
Compuestos de Amonio/análisis , Monóxido de Carbono/análisis , Carbón Orgánico/química , Óxidos de Nitrógeno/análisis , Óxidos/química , Compuestos de Calcio/análisis , Catálisis , Desnitrificación , Oxidación-Reducción , Óxidos/análisis , Oxígeno/análisis , Temperatura , Titanio/análisis
11.
J Cardiol ; 74(5): 428-435, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31101573

RESUMEN

BACKGROUND: Calciprotein particles (CPPs) have been suggested to be associated with the degree of coronary atherosclerosis, and have also been established as a molecular marker for clinical outcome in patients with chronic kidney disease (CKD). However, there are several concerns with regard to conventional measurement of CPPs. We therefore developed a new CPP measurement system that can detect both smaller and lower-density CPPs. METHODS: We analyzed 71 consecutive patients who underwent percutaneous coronary intervention for acute coronary syndrome (ACS, n=29) and/or stable angina pectoris (AP, n=42) who did not have CKD of stage 4 or greater. CPP measurement was made using an infrared fluorescent bisphosphonate (OsteoSense, PerkinElmer, Waltham, MA, USA) and a gel filtration method. The coronary artery plaque was analyzed by gray-scale intravascular ultrasound (IVUS) and integrated backscatter (IB)-IVUS. RESULTS: The median CPP level (interquartile range) was 40,953 (19,171-74,131) arbitrary units (AU). When we divided the CPP level into quintiles, the total and lipid plaque volume were incrementally higher with increasing quintile from lowest to highest (both p<0.02). After adjustment by age, body mass index, and estimated glomerular filtration rate, which factors were correlated with the above-described plaque components, the top quintile of CPP (>86,751AU) had significantly higher total plaque (263mm3 vs. 161mm3; p=0.001) and lipid plaque volume (156mm3 vs. 89mm3; p<0.001) than the other quintiles. However, these associations were not found for the fibrous or calcified plaque volume. The CPP level was higher in the ACS group than the stable AP group (p=0.02), and the total and lipid plaque volume were also higher in the ACS group than the stable AP group (both p<0.05). CONCLUSIONS: The results suggested that a high CPP level, as measured by the novel assay, is a surrogate marker for coronary atherosclerosis, especially in lipid-rich plaques, contributing to an increased risk of plaque vulnerability.


Asunto(s)
Síndrome Coronario Agudo/patología , Angina Estable/patología , Compuestos de Calcio/análisis , Enfermedad de la Arteria Coronaria/patología , Placa Aterosclerótica/diagnóstico , Síndrome Coronario Agudo/complicaciones , Síndrome Coronario Agudo/cirugía , Anciano , Angina Estable/complicaciones , Angina Estable/cirugía , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/cirugía , Estudios Transversales , Femenino , Tasa de Filtración Glomerular , Humanos , Lípidos/análisis , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea , Placa Aterosclerótica/complicaciones , Placa Aterosclerótica/cirugía , Factores de Riesgo , Índice de Severidad de la Enfermedad
12.
Chemosphere ; 226: 149-158, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30928714

RESUMEN

Acid deposition and algae blooms have resulted in great changes in the water chemistry of Taihu Lake; however, there have been few calculated results to describe these processes. Here we used a mass balance model to estimate base cation losses and evaluate the model applicability in this intensively human-impacted watershed based on a long-term database (1985-2015). The results showed that carbonate weathering induced Ca2+ and Mg2+ losses in the watershed were responsible for the increased ion net reaction (INR) of Ca2+and Mg2+ in the lake. While the increase of K+ and Na+ were not appropriate to provide independents check on the mass balance model because they generally entered the lake as human discharges, not reflecting change of the geochemical process in the watershed as the watershed dominant bedrock is carbonate but not silicate. Acid deposition in Taihu region caused decrease in pH, lime potential, and different Ca, Mg species of surface soils. Our field measurements of sediments in the two lake parts showed that the sediment lime potential was significantly higher in the algae dominated lake area than in the hydrophyte-dominated area due to the in-lake alkalinization by algae blooms, indicating that algae blooms played a significant role in the acidification resistance. Meanwhile, the measured lime potential of the watershed soils was lower than that of the sediment, implying a potential risk of acidification in the watershed. This research helps understand the accelerated interactions between human activities and natural geochemical processes and accelerated water chemistry change at the watershed level.


Asunto(s)
Cationes , Sedimentos Geológicos/química , Lagos/química , Suelo/química , Compuestos de Calcio/análisis , China , Monitoreo del Ambiente/métodos , Eutrofización , Humanos , Concentración de Iones de Hidrógeno , Óxidos/análisis
13.
Sci Adv ; 5(3): eaav8083, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30891501

RESUMEN

The application of 87Sr/86Sr in prehistoric mobility studies requires accurate strontium reference maps. These are often based from present-day surface waters. However, the use of agricultural lime in low to noncalcareous soils can substantially change the 87Sr/86Sr compositions of surface waters. Water unaffected by agriculture in western Denmark has an average 87Sr/86Sr ratio of 0.7124 as compared to an average of 0.7097 in water from nearby farmland. The 87Sr/86Sr ratio obtained from samples over 1.5 km along a stream, which originates in a forest and flows through lime-treated farmland, decreased from 0.7131 to 0.7099. Thus, 87Sr/86Sr-based mobility and provenance studies in regions with low to noncalcareous soils should be reassessed. For example, reinterpreting the iconic Bronze Age women at Egtved and Skrydstrup using values unaffected by agricultural lime indicates that it is most plausible that these individuals originated close to their burial sites and not far abroad as previously suggested.


Asunto(s)
Agricultura/historia , Agua Subterránea/química , Migración Humana/historia , Datación Radiométrica/métodos , Suelo/química , Isótopos de Estroncio/análisis , Agricultura/métodos , Arqueología/métodos , Compuestos de Calcio/análisis , Dinamarca , Femenino , Fertilizantes/análisis , Historia Antigua , Humanos , Óxidos/análisis
14.
J Sci Food Agric ; 99(3): 1302-1310, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30094839

RESUMEN

BACKGROUND: Lemongrass is an aromatic plant with antioxidant and antimicrobial properties, used for the preparation of medicinal tea and for essential oil production. Previous studies have shown that extracts of lemongrass leaves contain phenolic compounds associated with health benefits. Although essential oils have been widely used as flavoring agents, there is no scientific evidence regarding the use of lemongrass essential oils in beverages. Thus, the objectives of the present study were to develop blends with lemongrass derivatives (aqueous extract, lyophilized extract, and essential oil) and lime juice for the preparation of mixed beverages, to evaluate the antioxidant and physicochemical characteristics of blends, and to determine the sensory profile and acceptance of mixed beverages. RESULTS: The formulated blends showed favorable physicochemical characteristics such as acidity and color, and they contained bioactive compounds (phenolics and vitamin C) and important antioxidant properties. Mixed beverages prepared from blends containing aqueous extract or lyophilized extract plus essential oil, which showed higher intensity of lemongrass aroma and flavor, were more readily accepted. CONCLUSION: This study demonstrates that it is possible to make suitable blends with lemongrass derivatives and lime juice for the preparation of high-quality mixed beverages with sensory pleasantness, and potentially beneficial health components. © 2018 Society of Chemical Industry.


Asunto(s)
Antioxidantes/análisis , Bebidas/análisis , Compuestos de Calcio/análisis , Cymbopogon/química , Aditivos Alimentarios/análisis , Óxidos/análisis , Aromatizantes/análisis , Manipulación de Alimentos , Humanos , Aceites Volátiles/análisis , Fenoles/análisis , Gusto
15.
J Dairy Sci ; 102(1): 1-13, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30527984

RESUMEN

In addition to their high sodium content, cheeses are thought to induce an acid load to the body, which is associated with deleterious effects on consumers' health. Our objective was to explore the use of alkalinizing salts in partial substitution of NaCl to reduce both the sodium content and the acid-forming potential of cheese, without altering its sensory properties. Blue-veined cheeses were produced under industrial conditions, using brine salting followed by dry salting with a 4:1 (wt/wt) mixture of calcium lactate:NaCl or calcium citrate:NaCl. Sodium chloride was used in 2 granulometries: coarse (control treatment) and fine, to obtain homogeneous mixtures with the organic salts. Cheeses were then ripened for 56 d. No major appearance defects were observed during ripening. Calcium lactate substitution decreased the Na content of the cheese core by 33%, and calcium citrate substitution increased the citrate content of the cheese core by 410%, respectively, compared with fine NaCl. This study highlighted the substantial role of salt granulometry in sodium content, with the use of the coarse salt reducing the sodium content by 21% compared with fine salt. Sensory profiles showed nonsignificant differences in bitter and salty perceptions of salt-substituted cheeses with calcium lactate and calcium citrate compared with control cheeses. The use of calcium lactate should be considered to reduce the sodium content and improve the nutritional quality of cheeses while maintaining the sensory quality of the products. Alkalinizing organic salts could replace the acidifying salts KCl or CaCl2, which are currently used in salt replacement and are not recommended for consumers with renal disease. The method described here should be considered by cheese-making producers to improve the nutritional quality of cheese. Additional nutritional optimization strategies are suggested.


Asunto(s)
Compuestos de Calcio/metabolismo , Queso/análisis , Lactatos/metabolismo , Cloruro de Sodio Dietético/metabolismo , Análisis de Varianza , Animales , Calcio/análisis , Citrato de Calcio/análisis , Citrato de Calcio/metabolismo , Compuestos de Calcio/análisis , Bovinos , Queso/normas , Manipulación de Alimentos/métodos , Concentración de Iones de Hidrógeno , Lactatos/análisis , Valor Nutritivo , Odorantes , Sales (Química) , Cloruro de Sodio Dietético/efectos adversos , Cloruro de Sodio Dietético/análisis , Gusto/efectos de los fármacos
16.
Artículo en Inglés | MEDLINE | ID: mdl-30563040

RESUMEN

Acid mine drainage (AMD) is a serious environmental problem resulting from extensive sulfide mining activities. There is a lack of more comprehensive and detailed studies on the effect of AMD on calcareous soil characteristics and seed germination. In this study, five calcareous soil samples, collected from Xiaoyi, Taigu, Xiangning, Hejin, and Xixian counties in Shanxi Province, China, were used to investigate the effects of acid AMD on soil characteristics and Lolium perenne L. germination through laboratory culture experiments. The results showed that the increase in the total soil calcium oxide and magnesium oxide (CaO + MgO) contents led to a rise in the amount of Fe2+ in AMD converted into Fe3+, and that major ions (H⁺, Fe, SO42-) in AMD were trapped in the soil. The total Cao + MgO contents in the soil collected from Hejin and Taigu counties were 14.23% and 6.42%, the pH of AMD-polluted soil decreased to 7.24 and 3.10, and 98.7% and 54.0% of the Fe2+, 99.9% and 58.6% of the total Fe, and 76.0% and 26.4% of the SO42-, respectively, were trapped in the soil when the AMD volume to soil mass ratio was 10 mL/g. The results for the soil from Taigu County showed that when the soil had an AMD volume to soil mass ratio of 10 mL/g, the organic matter, available phosphorus (available P), available potassium (available K), Cr, and Cd contents in soil decreased by 16.2%, 63.0%, 97.1%, 7.8%, and 73.2%, respectively; the total phosphorus (total P) and total potassium (total K) did not significantly change; whereas the available nitrogen (available N) and total nitrogen (total N) increased to 16.1 times and 1.76 times, respectively. Compared to the initial soil collected from Taigu County, the Lolium perenne L. germination rate decreased by 81.1%, and the cumulative amount of Cr in the Lolium perenne L. increased by 7.24 times in the AMD-polluted soil when the AMD volume to soil mass ratio was 6 mL/g. The soil conditions could not support Lolium perenne L. germination when the AMD volume to soil mass ratio was 10 mL/g. The outcomes of this study could have important implication in understanding the hydrological/geochemical-behaviour of major ions of AMD in calcareous soil. The findings also have great significance in predicting plant growth behavior in AMD-polluted calcareous soil.


Asunto(s)
Lolium/efectos de los fármacos , Minería , Contaminantes del Suelo/análisis , Suelo/química , Compuestos de Calcio/análisis , China , Germinación , Lolium/crecimiento & desarrollo , Óxido de Magnesio/análisis , Óxidos/análisis , Fósforo/análisis , Contaminantes del Suelo/efectos adversos
17.
Water Sci Technol ; 2017(2): 578-591, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29851411

RESUMEN

A novel magnetic calcium silicate hydrate composite (Fe3O4@CSH) was proposed for phosphorus (P) removal and recovery from a synthetic phosphate solution, facilitated by a magnetic separation technique. The Fe3O4@CSH material was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), zeta-potential and magnetic curves. The chemical composition and structure of Fe3O4@CSH and the successful surface loading of hydroxyl functional groups were confirmed. Phosphate adsorption kinetics, isotherm, and thermodynamic experiments showed that adsorption reaches equilibrium at 24 h, with a maximum adsorption capacity of 55.84 mg P/g under optimized experimental conditions. Adsorption kinetics fitted well to the pseudo second-order model, and equilibrium data fit the Freundlich isotherm model. Thermodynamic analysis provided a positive value for ΔH° (129.84 KJ/mol) and confirmed that phosphate adsorption on these materials is endothermic. The P-laden Fe3O4@CSH materials could be rapidly separated from aqueous solution by a magnetic separation technique within 1 min. A removal rate of more than 60% was still obtained after eight adsorption/desorption cycles, demonstrating the excellent reusability of the particles. The results demonstrated that the Fe3O4@CSH materials had high P-adsorption efficiency and were reusable.


Asunto(s)
Compuestos de Calcio/análisis , Fosfatos/química , Silicatos/análisis , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Adsorción , Cinética , Magnetismo
18.
J Sci Food Agric ; 98(14): 5435-5443, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29675868

RESUMEN

BACKGROUND: The preharvest application of Ca-containing foliar fertilizers can reduce the incidence of bitter pit (BP) in apples and improve fruit quality by increasing the Ca content and decreasing both the N content and the N/Ca ratio in fruits. In this study, we aimed to investigate the control efficacy of Ca-containing fertilizers on the incidence of BP and their effects on the Ca and N contents in bagged 'Fuji' apples by spraying foliar fertilizer containing calcium chloride (CaCl2 ), calcium nitrate [Ca(NO3 )2 ] or calcium formate [Ca(HCOO)2 ] at an early stage, five days after full bloom (DAFB) and 40 DAFB, and at a late stage, 80 DAFB and 125 DAFB. RESULTS: The incidences of BP were reduced significantly by 43.2-73.0%, and the efficacy of spraying at an early stage was significantly higher than that of spraying at a late stage. The Ca content of bagged apple fruits increased whereas the N content and N/Ca ratio decreased after spraying Ca-containing foliar fertilizers; however, the Ca content, N content and N/Ca ratio of apple leaves were differentially influenced. CONCLUSION: Foliar fertilizer containing CaCl2, Ca(NO3 )2 or Ca(HCOO)2 can be used at an early stage to control BP in apple and improve the quality of bagged apple fruits. © 2018 Society of Chemical Industry.


Asunto(s)
Calcio/análisis , Fertilizantes/análisis , Malus/química , Nitrógeno/análisis , Calcio/metabolismo , Cloruro de Calcio/análisis , Cloruro de Calcio/metabolismo , Compuestos de Calcio/análisis , Compuestos de Calcio/metabolismo , Formiatos/análisis , Formiatos/metabolismo , Frutas/química , Frutas/metabolismo , Humanos , Malus/metabolismo , Nitratos/análisis , Nitratos/metabolismo , Nitrógeno/metabolismo , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Gusto
19.
Nutr Hosp ; 35(1): 11-18, 2018 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-29565143

RESUMEN

INTRODUCTION: Newborn infants and small children require large amounts of calcium and phosphate in a low volume of solution which can increase the risk of precipitation of calcium phosphate. Calcium gluconate is the predominant calcium salt form employed in parenteral nutrition (PN) compounding due to its solubility profile with phosphate. Unfortunately, calcium gluconate contains higher levels of aluminum contamination than calcium chloride, resulting in an increased potential for aluminum toxicity in patients receiving traditional PN. The physicochemical stability of 30 total parenteral admixtures containing inorganic calcium salts was evaluated. METHODS: Parenteral admixtures were prepared in one-chamber ethylene vinyl acetate bags: amino acids, glucose, electrolytes including only inorganic calcium salt and 20% (w/w) lipid emulsions (SMOFlipid®, Omegaven® or Lipofundin MCT/LCT®) were placed together in a one chamber bag. Admixtures were stored at +4 °C for up to eight days after preparation. Visual observations, globule size distribution (using optical microscopy, laser diffraction and photon correlation spectroscopy methods), pH analysis and zeta potential measurements were performed. RESULTS: The physicochemical stability of 29 of parenteral admixtures in the presence of inorganic calcium salt was confirmed. One admixture was deemed unsuitable for use in clinical practice due to the coalescence of oil droplets. CONCLUSION: Despite the presence of inorganic calcium salts, pediatric parenteral admixtures were stable up to eight days of storage. Due to presence of multiple components and a high risk of incompatibilities, physicochemical studies should be performed for each admixture before use in clinical practice.


INTRODUCCIÓN: los recién nacidos y los lactantes precisan aportes elevados de calcio y fósforo en soluciones con pequeño volumen lo que aumenta el riesgo de formar precipitados de fosfato cálcico. La principal sal de calcio empleado en nutrición parenteral (NP) es el gluconato cálcico, debido a su perfil de solubilidad con el fosfato. Lamentablemente el gluconato cálcico contiene unas concentraciones elevadas de aluminio mayores que el cloruro cálcico, lo que resulta en riesgo potencial de toxicidad por aluminio en pacientes que reciben NP. En este trabajo se evalúa la estabilidad fisicoquímica de 30 mezclas de NP con sales de calcio inorgánico. MÉTODOS: las mezclas de NP se prepararon en bolsas de acetato de etilenvinilo. En una bolsa unicameral se mezclaron aminoácidos, glucosa, y electrolitos incluyendo una sal de calcio inorgánico y una emulsión lipídica al 20% (SMOFlipid®, Omegaven®o Lipofundin MCT/LCT®). Las mezclas se almacenaron a +4 ° C hasta 8 días tras la elaboración. Se realizó un examen visual, estudio de la distribución del tamaño de los glóbulos (mediante microscopía óptica, difracción por láser y espectroscopia fotónica), análisis de pH y medición del potencial zeta. RESULTADOS: se confirmó la estabilidad fisicoquímica de 29 mezclas de NP que contenían sales de calcio inorgánico. Sólo una de las preparaciones se consideró inválida para su uso clínico debido a la coalescencia de las gotas de grasa. CONCLUSIÓN: a pesar de la presencia de sales de calcio inorgánico, las mezclas de NP pediátrica fueron estables hasta 8 días de almacenamiento. La presencia de múltiples componentes y el riesgo elevados de incompatibilidades hace recomendable el estudio de estabilidad fisicoquímica de cada mezcla antes de su empleo en la clínica.


Asunto(s)
Compuestos de Calcio/análisis , Soluciones para Nutrición Parenteral/análisis , Nutrición Parenteral , Niño , Composición de Medicamentos , Estabilidad de Medicamentos , Humanos , Lactante , Recién Nacido , Nutrición Parenteral en el Domicilio , Pediatría
20.
Lasers Med Sci ; 33(6): 1225-1236, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29453616

RESUMEN

Bone may be similar to geological formulations in many ways. Therefore, it may be logical to apply laser-based geological techniques in bone research. The mineral and element oxide composition of bioapatite can be estimated by mathematical models. Laser-induced plasma spectrometry (LIPS) has long been used in geology. This method may provide a possibility to determine the composition and concentration of element oxides forming the inorganic part of bones. In this study, we wished to standardize the LIPS technique and use mathematical calculations and models in order to determine CaO distribution and bone homogeneity using bovine shin bone samples. We used polished slices of five bovine shin bones. A portable LIPS instrument using high-power Nd++YAG laser pulses has been developed (OpLab, Budapest). Analysis of CaO distribution was carried out in a 10 × 10 sampling matrix applying 300-µm sampling intervals. We assessed both cortical and trabecular bone areas. Regions of interest (ROI) were determined under microscope. CaO peaks were identified in the 200-500 nm wavelength range. A mathematical formula was used to calculate the element oxide composition (wt%) of inorganic bone. We also applied two accepted mathematical approaches, the Bartlett's test and frequency distribution curve-based analysis, to determine the homogeneity of CaO distribution in bones. We were able to standardize the LIPS technique for bone research. CaO concentrations in the cortical and trabecular regions of B1-5 bones were 33.11 ± 3.99% (range 24.02-40.43%) and 27.60 ± 7.44% (range 3.58-39.51%), respectively. CaO concentrations highly corresponded to those routinely determined by ICP-OES. We were able to graphically demonstrate CaO distribution in both 2D and 3D. We also determined possible interrelations between laser-induced craters and bone structure units, which may reflect the bone structure and may influence the heterogeneity of CaO distributions. By using two different statistical methods, we could confirm if bone samples were homogeneous or not with respect to CaO concentration distribution. LIPS, a technique previously used in geology, may be included in bone research. Assessment of element oxide concentrations in the inorganic part of bone, as well as mathematical calculations may be useful to determine the content of CaO and other element oxides in bone, further analyze bone structure and homogeneity and possibly apply this research to normal, as well as diseased bones.


Asunto(s)
Densidad Ósea , Huesos/química , Geología/instrumentación , Rayos Láser , Gases em Plasma/química , Análisis Espectral/métodos , Animales , Huesos/diagnóstico por imagen , Compuestos de Calcio/análisis , Hueso Esponjoso/química , Hueso Esponjoso/diagnóstico por imagen , Bovinos , Modelos Biológicos , Modelos Teóricos , Óxidos/análisis , Óxidos/química , Espectrofotometría Atómica , Estadística como Asunto , Tomografía Computarizada por Rayos X
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