Bioavailability of β-cryptoxanthin in the presence of phytosterols: in vitro and in vivo studies

Bioactive compounds are used in the design and development of new food products with potential health benefits, although little is known regarding their bioavailability and interactions. This study assessed the stability, in vitro bioaccessibility, and human bioavailability of β-cryptoxanthin from β-cryptoxanthin-rich drinks with and without added phytosterols developed for this purpose. The developed drinks showed no difference in the content of β-cryptoxanthin, and they were stable over 6 months. In vitro, hydrolysis of β-cryptoxanthin esters and the amount of free β-cryptoxanthin at duodenal and micellar phases were similar regardless of the presence of phytosterols. In the human study, the daily intake provoked significant increments of β-cryptoxanthin in serum regardless of the type of the drink. In conclusion, in vitro and in vivo human studies have shown that the bioavailability of β-cryptoxanthin is not significantly affected by the presence of phytosterols when they are simultaneously supplied in a drink.     

Size of Microbial Biomass in Soils of China

The microbial biomass C,N and P of soils all over China were determined in this study to study their affecting factors.The results,about 100-417 mg C kg^-1 soil,18-51 mg Nkg^-1 soil and 4.4-27.3mg P kg^-1 soil,showed the biomass C,N and P in linear relationship with the soil total organic C,toal N and soil organic P.The ratios of C:Nand C:P,ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively,were affected by soil pH.texture,crop rotation,macroclimate etc.The ratio of C:N in soil biomass increases gradually from the north to the south in China.     

Fractionation of Zinc in Paddy Soils of China

The rice fields in China amount to 25.4 million hectares of which low yield paddy soils areabout 26％(Xu,1981;Xiao,1981).One of the most important causes of low yield is the defi-ciency in nutrients including zinc.Zinc deficiency usually occurs in calcareous paddy soils withpH>6.5(Zhu and Liu,1981).And the availability of zinc in calcareous paddy soils is lowerthan that in neutral and acid paddy soils.     

Transformation of Fertilizer-N in Rhizosphere Soils of Wheat

INTRODUCTION There is a close relationship between the transformation of fertilizer-N and the statusof nitrogen nutrition in rhizosphere soils.Previously,Harmsen and Jager(1962)made ananalysis of N and C contents in the rhizosphere soils of upland crops and found thatclose to the root zone there was an enrichment of these substances.     

Assessment and prediction of changes in the reserves of organic carbon in abandoned soils of European Russia in 1990–2020

Experimental studies and the analysis of published data have shown that carbon reserves in soils generally increase upon soil exclusion from agricultural use. The rate of carbon accumulation in the abandoned soils depends on the soil type, the time elapsed since the soil abandoning (the restoration period), and the thickness of the layer for which the rate of carbon accumulation is determined. For the upper 20-cm-thick layer, it varies from 66 to 175 g C/m² per year in dependence on the type of soil and averages 111 g C/m² per year. The highest rate is typical of the first 10–15 years of soil restoration. According to our calculations, the carbon sequestration in the upper 20-cm-thick layer of Russian soils due to changes in land use was 184–673 Mt C in 1990–2005 and may reach 282–1030 Mt C by 2020.     

Influence of Salinity in the Bioavailability of Zn in Sediments of the Gulf of Cádiz (Spain)

This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K _D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p?<?0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p?<?0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease.     

Substances in Urban Snow. A comparison of the contamination of snow in different parts of the city of Luleå, Sweden

The aim of the study was to investigate how the quality of snow varies within a city. The study area is situated in the Luleå municipality, in northern Sweden (lat. 65°35′N and long. 22°10′E). For this study, the city was divided into three different types of areas: housing areas, city centre and outskirts. In one area of each type, sampling sites were selected. Snow samples were taken at nine occasions, once every fourteenth day in the city centre and in the housing area. Analyses were carried out for pH, conductivity, suspended solids and both the total and dissolved concentration of phosphorus and selected metals. It was concluded that traffic or activities related to traffic were a major source of heavy metals and phosphorus in urban snow, both in the city centre and in the housing area. Also, the type of area and the design of the street were important for the quality of snow. A clear relation was found between the pH and the quantity of suspended solids in the snow. Higher pH values were found in snow samples from sites with higher traffic loads, and lower pH values at sites, which were the no-traffic sites, with small quantities of particles. The particulate and dissolved substances in the snow behaved in different ways.     

Difference in selenium accumulation in shoots of two rice cultivars

Two japonica rice （Oryza sativa L.） cultivars, Xiushui 48 and S. Andrea, differing in their ability to accumulate Se in the grain （as high as a three-fold difference）, were compared for selenium （Se） accumulation in their shoots when their growth media was supplied with different forms of Se. Results indicated that when treated with 0.25μmol L^-1 Na2SeO3, Xiushui 48 accumulation of Se in the shoots was significantly more rapid （P〈0.05） than S. Andrea, probably because of greater Se uptake and transport in Xiushui 48. Xiushui 48 rice seedlings had a higher shoot-Se accumulation rate and absorbed selenocysteine （Se-Cys） more rapidly than S. Andrea seedlings. However, when treated with Se as 0.25μmol L^-1 selenomethionine （Se-Met）, the S. Andrea seedlings＇ accumulation rate was significantly greater （P〈0.05） than that of Xiushui 48. Possibly, the high Se accumulation rate of Xiushui 48 seedling shoots compared to S. Andrea shoots was the result of a higher capacity of Xiushui 48 to transform selenite to organic Se compounds and a higher selenite uptake rate.     

Status of Soil Zn in Citrus-Cultivated Area of South China

INTRODUCTION In recent 10 years,citrus production has developed rapidly in China.The citrus-cul-tivated area of our country is among the largest and its yield occupies the third place inthe world(Shen,1991).     

Analysis of variation patterns in rice milled quality in the offspring of indica–japonica hybridization

Genetic Resources and Crop Evolution - Asian cultivated rice (Oryza sativa L.) is divided into two subspecies, indica (O. sativa L. subsp. indica) and japonica (O. sativa L. subsp. japonica)....     

Radiocarbon pollution and self-purification of humus in chernozems of the East-European plain in 1900–2008

The dynamics of the ¹⁴C content in the humus of chernozems in 1900?C2008 are considered. The elevated ¹⁴C content in the atmosphere because of nuclear weapons tests has led to the contamination of humus with bomb radiocarbon. In 1966?C1968, the ¹⁴C reserves in the profiles of chernozems exceeded the background ones by 15%; in 1978, by 12%; and, in 1998, by 2%. By the year of 2008, its reserves became equal to the background ones. The ¹⁴C distribution along the soil profiles changed. By 1978, the 0- to 30-cm-thick soil layer became free from radiocarbon due to its self-purification; however, at depths of 40?C70 and 100?C115 cm, its weak accumulation was registered. By 2008, the whole soil profile was free from ¹⁴C. The main mechanism of the soil self-purification from radiocarbon is suggested to be the constant substitution of fragments of humus compound structures for those of fresh organic matter entering the soils with the ¹⁴C content being in equilibrium with the atmospheric one, i.e., due to the renewal of the carbon in the humus. The rate of the carbon renewal and its migration in the soils are assed based on the ¹⁴C concentrations in the humus.     

Input and migration of dissolved organic carbon in soils of forest ecosystems in the subzone of deciduous–coniferous forests

The results of four-year monitoring of natural waters in forest ecosystems of the Zvenigorod Biological Station (Moscow State University, Moscow oblast) show regular changes in the concentrations and fluxes of dissolved organic carbon (DOC) within the atmospheric precipitation–throughfall–soil waters system. Precipitation passing through the tree canopy is enriched with DOC (2–3 and 9–24 mg/L). The average carbon concentration in soil waters reaches 100–110 mg/L in complex spruce and pine–spruce forests and does not exceed 40–60 mg/L in spruce–birch forests.     

The content of microelements and iron in soils and plants in the basin of lake Kotokel’ in Western Transbaikalia

The content of microelements (Mn, Zn, Cu, Co, Ni, Cr, Pb, and Cd) and Fe is determined in the soils and plants of the Lake Kotokel’ basin. Their content in the soils is proved not to exceed the regional background and the existing MPC and APC. The content of Cd is revealed to exceed its clarke value for the world soils, which is related to the natural origin of this element. The concentrations of Mn, Co, and Pb are close to their clarke values, and those of Zn, Cu, Ni, and Cr are lower than their clarkes. The studied soils are specified by the maximal amount of the mobile forms of microelements. The profile distribution of the microelements differs depending on the genetic soil type. For Mn, Zn, and Cu, a significant biogenic accumulation is pronounced in the organic soil horizons. The content of microelements in the aboveground phytomass exceeds the maximal permissible levels for Mn, Co, Cr, and Fe. The intensity of the microelements absorption by the plants varies widely, being specified by the high coefficient of the biological adsorption (except for Fe). Mn, Zn, and Cu are accumulated in the plant phytomass the most intensely.     

Transformation and Availability of Various Forms of Zinc in Soils

The transformation and availability of various forms of Zn applied into a cinnamon soil and a carbonate meadow soil as well as the effects of fertillizer-P on them were studied by using the field experiment method and chemically sequential extraction procedure.Zn added into the soils was found to be rapidly transformed into the various forms. In the cinnamon soil,the amount of Zn transformed into the carbonate bound form was the highest,and the carbonate bound form was proven by the analyses of intensity factor and capacity factor to be the primary available Zn pool.But in the carbonate meadow soil,the Zn transformed was relatively homogeneously distributed in the various forms though the amount of Zn transformed into the Mn-oxide bound form was relatively high,and the organically bound,Mn-oxide bound and amorphous Fe-oxide,bound forms were found to be the main available Zn pool.Fertilizer-P took part in the regulation and control of available Zn in the soils to a certain degree.In the carbonate meadow soil,application of P fertilizer probably aggravated Zn deficiency at low Zn rate,while it was favorable to the storage of available Zn in the case of high Zn rate.     

Surface Chemical Properties of Colloids in Main Soils of China

Surface chemical properties of soil colloids are the important factor affecting soil fertility and genesis.To provide scientific basis for soil genetic classification,promotion of soil fertility and reasonable fertilizqation,the specific surface area and electric charge of soil colloids in relation to clay minerals and organic matter are further discussed on the basis of the results obtained from the studies on surface chemical properties of soil colloids in five main soils of China.Results from the studies show that the effect of clay minerals and organic matter on the surface chemical properties of soil colloids is very complicated because the siloxane surface,hydrated oxide surface and organic matter surface do not exist separately,but they are always mixed together and influenced each other.The understanding of the relationship among clay minerals,organic matter and surface chemical properties of soil colloids depends upon further study of the relevant disciplines of soil science,especially the study on the mechanisms of organo-mineral complexes.     

Integration of Soil pH with Soil‐Test Values of Zinc for Prediction of Yield Response in Rice Grown in Mollisols

Seventeen Mollisols having pH_(1:2) in the range of 6.00 to 8.42 were analyzed with five extractants, and the extractable zinc (Zn) ranges were 0.84 to 2.75 mg Zn kg^?1 soil for diethylenetriaminepentaacetic acid (DTPA) (pH 7.3), 0.91 to 2.72 mg Zn kg^?1 soil for DTPA + ammonium bicarbonate (pH 7.6), 1.82 to 7.18 mg Zn kg^?1 soil for Mehlich 3, 1.22 to 3.83 mg Zn kg^?1 soil for ethylenediaminetetraacetic acid (EDTA) + ammonium carbonate, and 0.88 to 1.18 mg Zn kg^?1 soil for 1 mol L^?1 magnesium chloride (MgCl₂) (pH 6.0). Zinc extracted by DTPA (pH 7.3) and Mehlich 3 showed significant positive correlation with sand content, whereas only Mehlich 3 showed negative correlation with soil pH. All extractants showed significant positive correlation with each other except for 1 mol L^?1 MgCl₂‐extractable Zn, which had significant positive correlation with only Mehlich 3– and EDTA + ammonium carbonate–extractable Zn. A greenhouse experiment showed that Bray's percentage yield of rice was poorly correlated to extractable soil Zn but had a significant and negative linear correlation with soil pH (r = ?0.662, significant at p = 0.01). Total Zn uptake by rice had a significant positive correlation with 1 mol L^?1 MgCl₂– and Mehlich 3–extractable Zn. A proposed parameter (p extractable Zn + p OH^?) involving both soil extractable Zn and pH terms together showed significant and positive correlation with Bray's percentage yield and total Zn uptake of rice. The calculated values of critical limits of soil Zn in terms of the proposed parameter were 14.1699 for DTPA (pH 7.3), 13.9587 for DTPA + ammonium bicarbonate, 13.7016 for Mehlich 3, 13.9402 for EDTA + ammonium carbonate, and 14.1810 for 1 mol L^?1 MgCl₂ (pH 6.0). The critical limits of Zn in rice grain and straw were 17.32 and 22.95 mg Zn kg^?1 plant tissue, respectively.     

Factors Affecting Diffusion of Ions in Soils

In this work the diffusion coefficients of Na+, K+, Ca2+, NO3- and Cl- ions were estimated in terms of measuring apparent direct current (DC) conductivities of latosol, red soil and yellow-brown earth containing, respectively, NaNO3, KCI, and CaCl2 of different concentrations (0.005, 0.05, 0.10, and 0.15 mol/L) in the case of moisture contents ranging from wet to water saturation. The results showed that when bulk density, moisture content, and electrolyte concentration were constant, the diffusion coefficients of cations were in the order Na+> K+> Ca2+ except for Na+ and K+ in latosol, while the order for anions was NO3- > Cl-. The diffusion coefficients (Di) of cations and anions were linearly proportional to volumetric moisture content (θ) as electrolyte concentration and bulk density were unchanged. When moisture content and bulk density were constant, the diffusion coefficients of cations decreased, to varying extents, with the increase of electrolyte concentration, and the decrement in differen     

Chemiqal Behavior of Cadmium in Wheat Rhizosphere

The present study deals with some chemical behavior,including Cd extractability,species transformation and adsorption-desorption characteristics,of Cd in the rhizosphere(R) of wheat seedlings grown on both yellow-brown earth(YBE) and red earth (RE).Results indicated an increase of pH about 0.5 unit in the R of the yellow-brown earth and a decrease about 0.4 unit in the R of red earth in comparison with their respective bulk soils(NR).More Cd adsorbed and less Cd desorbed,and hence less Cd extracted in the R of YBE than those in the NR were found.The opposite cases were got for the R of RE.Fractionation experiment showed that in the R of YBE,more Cd was bound to Mn oxides and organic matter,less Cd was in exchangeable form,and little Cd was bound to amorphous and crystal iron oxides.However,little difference of the Cd species between the R and NR of RE was found. Regression analysis indicated that pH was one of the dominant factors affecting the chemical behavior of Cd in rhizosphere.