Physicochemical Properties of Starches from Lotus Rhizomes Harvested in Different Months.

We investigated the physicochemical properties of starches extracted from 8 lotus (Nelumbo nucifera Gaertn.) rhizomes harvested in different months (September 2012 to May 2013). The physicochemical properties of the lotus starches depended on the harvest date. The peak viscosity (PV) in the Rapid Visco-Analyser analysis, and the viscosity at 65 °C (V65) in the rotational viscometer analysis were significantly lower in SEP starch (extracted from the September-harvested sample) than in the other lotus starches. The Spearman's rank correlation coefficients of potassium ion (K) content vs. V65 and of K content vs. PV were 0.905 and 0.714, respectively, indicating that potassium ions are important for expressing the pasting properties of lotus starch. Principal component analysis suggested that the potassium, magnesium, calcium, and phosphorus contents are important for displaying both the pasting and gelatinization properties of the lotus starches. Meanwhile, the cluster analysis revealed that physicochemical properties of the SEP starch were different from those of the starches harvested in other months.

Characterization of soil organic matter with different degrees of humification using evolved gas analysis-mass spectrometry.

Evolved gas analysis-mass spectrometry (EGA-MS) provides a direct connection between the pyrolyzer and mass spectrometer through a deactivated capillary tube, and provides both a thermal profile relating to the differential thermogravimetric curve of the sample and a mass spectrum of evolved gas from the sample. In this study, EGA-MS was performed to obtain thermal profiles and identify the pyrolysis products of 12 humic acids (HAs) with different degrees of humification extracted from 5 Andisols, 3 Entisols, and 3 Inceptisols, as well as soil samples. All HAs were thermally decomposed gradually over a wide temperature range (100-700°C), and the EGA curves showed four peaks and shoulders at around 250, 350, 450, and 550°C. The peaks at around 550°C were observed for the Andisol HAs only. Carboxyl groups, carbohydrates, and short chain alkanes and alkenes of the HAs and bulk soil samples evolved at a relatively low-temperature region (200-300°C). On the other hand, aromatics including benzenes and lignin derivatives evolved at a relatively high-temperature region (300-600°C). While the shapes of the EGA curves were different between the soils and extracted HAs, the major components of the evolved gas and the pyrolysis behavior of the constituents in the HAs and soil samples were similar. The amount of evolved gas from the Andisol HAs, which mainly consisted of CO2, was very low in comparison to that from the Entisol and Inceptisol HAs. The amount of evolved gas and the molecular weight of the pyrolysis products decreased as humification progressed, but the proportion of CO2 in the total area of the EGA curves increased. The results demonstrated that humification reduces the proportion of volatile components and increases the amount of carboxyl groups. As a result, the molecular structure of HAs is found to be mainly composed of non-volatile components and carboxyl groups. Since EGA-MS can provide information about the chemical structure and pyrolysis characteristics of a small sample without pretreatment, it is a useful tool for soil organic matter research.

Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids.

Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, (13)C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant.

Physicochemical Properties of Starches from Different Lotus Cultivars in Japan: Shinashirobana cultivar and Kanasumi-line No. 20.

We investigated the physicochemical properties of starches from rhizomes of two lotus (Nelumbo nucifera Gaertn.) cultivars, Shinashirobana cultivar and Kanasumi-line No. 20, harvested at the same farm in Japan. A rapid visco analyser analysis indicated that pasting temperatures of the starches from Shinashirobana cultivar and Kanasumi-line No. 20 were 62.1 and 66.5 °C, respectively, and the peak viscosities of the starch of both lotuses were similar 244 and 240 RVU, respectively. The starch from the Kanasumi-line No. 20 at 60 °C had low viscosity, 16.2 mPa∙s, but the starch from Shinashirobana cultivar had higher viscosity, 2,720 mPa∙s, at 60 °C. The onset and peak temperatures of the differential scanning calorimetry (DSC) curve of the starch from Shinashirobana cultivar were 4-5 °C lower than those of the starch from Kanasumi-line No. 20, although both exhibited similar ΔH values (13.4 and 11.6 J/g). The distribution patterns of the branched chain lengths of amylopectin in the two starches indicated that the rate of low-degree of polymerization (DP 5-12) of all branched chains was higher for the starch from Shinashirobana cultivar than that for the starch from Kanasumi-line No. 20. These results suggest that the increased rate of DP 5-12 in the starch from Shinashirobana cultivar is related to the higher viscosity of the starch.

Activation of Nitrogen-Fixing Endophytes Is Associated with the Tuber Growth of Sweet Potato.

Endophytic nitrogen-fixing organisms have been isolated from the aerial parts of field-grown sweet potato (Ipomoea batatas). The (15)N dilution method, which is based on the differences in stable nitrogen isotope ratios, is useful for measuring nitrogen fixation in the field. In this study, seedlings of two sweet potato cultivars, 'Beniazuma' and 'Benikomachi,' were transplanted into an alluvial soil that had been treated with organic improving material in advance. Whole plants were sampled every 2 or 3 weeks. After separating plants into tuberous roots and leaves, the fresh weights of the samples were measured, and the nitrogen content and natural (15)N content of leaves were determined with an elemental analyzer and an isotope ratio mass spectrometer linked to an elemental analyzer, respectively. The contribution of nitrogen fixation derived from atmospheric N2 in sweet potato was calculated by assuming that leaves at 2 weeks after transplanting were in a non-nitrogen-fixing state. The contribution ratios of nitrogen fixation by nitrogen-fixing endophytes in leaves of both sweet potato cultivars increased rapidly from 35 to 61 days after transplanting and then increased gradually to 55-57% at 90 days after transplanting. Over the course of the sweet potato growing season, the activity of nitrogen-fixing endophytes in leaves began to increase at about 47 days after transplanting, the weight of leaves increased rapidly, and then growth of tuberous roots began a few weeks later. Our findings indicate that nitrogen-fixing endophytes will be activated under inorganic nitrogen-free sweet potato cultivation, allowing for growth of the tuberous roots.

Cadmium sorption characteristics of phosphorylated sago starch-extraction residue.

The residue produced by the extraction of sago starch is usually discarded as a waste material. In this study, we phosphorylated the sago starch-extraction residue with phosphoryl chloride and used the phosphorylated residue to remove cadmium from wastewater. The phosphoric ester functionality in the phosphorylated residue was evaluated by means of infrared microspectrometry and solid-state NMR. The dependence of the cadmium sorption behavior on pH, contact time, and electrolyte concentration and the maximum sorption capacity of the phosphorylated residue were also studied. The cadmium sorption varied with pH and electrolyte concentration, and the maximum sorption capacity was 25.2 mg g(-1), which is almost half the capacity of commercially available weakly acidic cation exchange resins. The phosphorylated residue could be reused several times, although cadmium sorption gradually decreased as the number of sorption-desorption cycles increased. The phosphorylated residue sorbed cadmium rapidly, which is expected to be favorable for the continuous operation in a column.

Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice-wheat rotational cultivation.

The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha(-1)) and a material derived from MgO and magnesium silicate minerals named 'MgO-SH-A' (2250 and 4500 kg ha(-1)1), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice-wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg(-1)). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha(-1) produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg(-1). It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.

Suppressive effects of magnesium oxide materials on cadmium uptake and accumulation into rice grains I: Characteristics of magnesium oxide materials for cadmium sorption.

The objective of this study is to assess the applicability of a commercial magnesium oxide (MgO) and a composite material containing MgO and natural minerals ('MgO-SH-A') as the soil amendments for suppression of cadmium (Cd) uptake and accumulation into rice grains. Firstly, the mineralogical and physicochemical properties, soil neutralizing capacities and Cd sorption characteristics of these materials were investigated. Both materials were strongly alkaline and possessed large surface areas. The X-ray diffraction pattern of MgO-SH-A indicated the presence of MgO and a magnesium-silicate mineral (antigorite) as the main components. MgO-SH-A showed a milder soil neutralizing capacity as compared to commercial MgO. The sorptions of Cd on commercial MgO and MgO-SH-A both fitted Langmuir isotherm. The maximum Cd sorption capacity of commercial MgO (46.8 mmol g(-1) DW) was higher than that of MgO-SH-A (5.87 mmol g(-1) DW), although the latter material showed higher affinity to Cd as compared to the former one. The dominant reaction involved in the Cd sorptions was suggested to be precipitation of Cd(OH)2 on the material surface. About 40% of Cd sorbed on MgO-SH-A was resistant to desorption by 0.1 M HCl, implying that this portion was strongly retained on the material surface.

Suppressive effects of magnesium oxide materials on cadmium uptake and accumulation into rice grains II: Suppression of cadmium uptake and accumulation into rice grains due to application of magnesium oxide materials.

The objective of this study is to assess the applicability of a commercial magnesium oxide (MgO) and a composite material containing MgO and natural minerals ('MgO-SH-A') as the soil amendments for suppression of cadmium (Cd) uptake and accumulation into rice grains. A cultivation experiment of rice plants (Oryza sativa L. cv. Kinuhikari) was conducted in an actual Cd-contaminated alluvial paddy field to evaluate the effectiveness of these materials. The 'plant available' fractions of Cd in the paddy soil significantly decreased by application of commercial MgO at 2250 kg ha(-1) or MgO-SH-A at 4500 kg ha(-1). These decreases would be primarily attributed to the increase in soil pH due to applications of the MgO materials because these soil Cd fractions were significantly negatively correlated with the soil pH. Even under a suppressive condition for Cd uptake by rice plants, i.e., continuous flooding of the paddy field around the heading stage, applications of these materials further reduced Cd concentration in brown rice as compared to that from the control. It was concluded that the two MgO materials examined would be effective in preventing Cd contamination of rice grains grown in Cd-polluted paddy fields.

The input-output balance of cadmium in a paddy field of Tokyo.

Field monitoring was practiced from 2001 to 2003 to evaluate the input (irrigation, atmospheric deposition, and fertilizer application) and the output (uptake and accumulation into the above-ground biomass of rice plants and leaching) of cadmium (Cd) in a contaminated paddy field in Tokyo. The cadmium concentrations of irrigated water, open-bulk precipitation, soil solution (leaching water), rice plants collected at the harvesting stage and the chemical fertilizer and the cow manure compost applied were determined. The Cd flux of each factor was calculated by multiplying the Cd concentration by the volume or mass of the media. The annual input-output balance of Cd in the paddy field in 2001 and 2002 was estimated to be -5.44 [corrected] g ha(-1) and -2.01 [corrected] g ha(-1), respectively, indicating the loss of Cd from the paddy field, although the losses accounted for only 0.24% [corrected] and 0.089% [corrected] of the total amount of Cd in the ploughed layer soil in 2001 and 2002, respectively. Among the factors involved, the input from fertilizers (including manure compost) and the output due to the uptake by rice plants played a major role in the balance. The former largely depended on the types and amounts of fertilizers applied, and the latter on the water management practices in the paddy field, such as flooding and drainage of the surface water.

Basal blood flow in complex regional pain syndrome does not necessarily indicate vasoconstrictor nerve activity.

OBJECTIVES: To quantitatively investigate simultaneous skin blood flow and sweating in a patient with complex regional pain syndrome. METHOD: Using one probe, skin blood flow and sweating were measured on the affected and non-affected sides at baseline and after activation of sympathetic system in a 47-year-old woman with complex regional pain syndrome type I of the left hand. RESULTS: Basal sweating, sympathetic sweat response, basal blood flow, sympathetic flow response, and attrition rate of blood flow (the ratio of sympathetic flow response to basal blood flow) of the affected side were greater than those on the non-affected side. CONCLUSIONS: Although sympathetic nerve activity (sympathetic flow response) appeared greater on one side, basal blood flow was also greater on that side. These contradictory results suggest that some factor or factors increase basal blood flow despite a higher sympathetic nerve tone on the side. Comparing basal blood flow on one side to the contralateral side does not necessarily indicate lesser vasoconstrictor nerve activity on that side. Advantages of simultaneous measurement of skin blood flow and sweating with a single probe may make the method useful.

Micro volume changes due to Pb(II) and Cu(II) sorption on amorphous Fe(III) hydroxide.

Micro volume changes due to Pb(II) and Cu(II) sorption on amorphous Fe(III) hydroxide (AFH) were determined by a dilatometer at pH 4.50. Volume change is attributed to change in hydration status of dissolved and/or suspended substances. The volume of the system increased due to Pb(II) and Cu(II) sorption, suggesting that water molecules hydrated around Pb(II) or Cu(II) ions and AFH were released during sorption. Volume increases due to Pb(II) and Cu(II) sorption were smaller than those due to bulk precipitation of Pb and Cu hydroxides. Precipitation of Pb(II) and Cu(II) was not likely to occur at pH 4.50 in the presence of AFH. In conclusion, Pb(II) and Cu(II) formed an inner-sphere complex on AFH at pH 4.50, keeping hydrated water on the adsorbed species. Adsorbed Cu(II) kept more hydrated water than adsorbed Pb(II) on AFH.