Advanced Materials Research Vols. 726-731

Abstract: By taking advantage of the model of wheat-straw returning to field, we investigated the survey on the transitional trend of the temperature, pH, DO, COD and the bacterial number of the overlying temperature when wheat-straw returned to field. The result indicated that on the 22nd day of the test, the pH (7.60) and DO value (4.12 mg/L) of the wheat-straw returning stimulation area were obviously lower than the pH(7.85) and DO value (6.98 mg/L) of the control area. However, the COD value (35.0 mg/L) was clearly higher than that of the control area (26.0 mg/L). The result showed that the organic content among the overlying water in the straw returning stimulation area was improved and meanwhile the capacity of the self-purification of water is lower. At the same time, there was no significant difference of the total number of bacteria between the overlying water and the control area (p=0.656218). However, the proportion of cellulose bacteria was the 75 times of that in the control area, with the absolute growth advantages.

Abstract: A water-soluble polysaccharide named as HPS-1 was isolated from the roots of Hedysarum polybotrys Hand.-Mazz by hot water extraction, anion-exchange and gel-permeation chromatography and tested for its antitumor activity. Its structural characteristics were investigated by FTIR, HPLC, NMR spectroscopy, GLCMS, methylation analysis, Periodate oxidation and Smith degradation. Based on the data obtained, HPS-1 was found to be an α- (14)-D-glucan, with a single α-D-glucose at the C-6 position every nine residue, on average, along the main chain. The glucan has a weight-average molecular weight of about 9.4×10⁴ Da. MTT assay revealed that HPS-1 significantly inhibited the proliferation of Human hepatocellular carcinoma HEP-G2 cells and human gastric cancer MGC-803 cells in vitro, indicating HPS-1 could have a possible cancer therapeutic potential.

Abstract: To investigate the chemical constituents of the seed of Stellera Chamejasme L, the constituents were isolated by silica gel, and polyamide column chromatography, and their structures were determined on the basis of spectroscopic analysis. Three compounds were obtained and identified as umbelliferone, 3-hydroxy-6-methoxy-7-(2-oxochromen-7-yl) oxychromen-2-one and dephnin. A novel compound two was isolated from the seed of Stellera Chamejasme L.

Abstract: The adult male Rana nigromaculata were exposed to different doses of cadmium for 30d, serum concentrations of the steroid hormones, testosterone and estradiol were examined. Chronic exposure to cadmium caused significant changes both at the testosterone and estradiol levels. Exposure to cadmium resulted in lesser serum testosterone concentrations and more estradiol in 0.05 and 0.1 ppm. Although not statistically significant, frogs exposed to 0.2 ppm had smaller drop in testosterone and significant more estradiol. The results suggest that cadmium exhibited the non-monotonic dose-response relationship with the serum hormone concentrations, testosterone and estradiol.

Abstract: Rapid industrialization and usage of heavy metals in industrial processes have resulted in unprecedented increase in the heavy metal flux into groundwater. Hexavalent chromium is one of elements with high health risks such as mutagenicity and carcinogenicity. Adsorption is economically feasible alternative of chromium removal. We have used spectrophotometric method for monitoring of hexavalent chromium adsorption from aqueous solution with the use of black as adsorbent. We have monitored the influence of temperature and surface treatment on the adsorption process.

Abstract: Serratia marcescens strain JPP1 was isolated from the peanut hulls in Jiangsu Province, China. The strain exhibited antagonistic activity against aflatoxins production and chitinolytic activity by producing chitinases. For chitinase production glucose was identified as best carbon source, peptone as organic nitrogen source while ammonium sulphate as the best inorganic nitrogen source led to the highest chitinase activity. Chitin served as an essential inducer and chitinase production reached the peak level after 1.2% of chitin concentration. The crude chitinase was highly thermostable and had activity in broad pH (2-11) and temperature (30-90°C) range. Ca and Mn ions enhanced the chitinase production, while Na and K were of inhibitory action not more than 5%, and Cu, Zn and Fe ions resulted in drastic enzyme inhibition ranged between 63.7 to 70.5%. Addition of EDTA, mercaptoethanol and Tween 80 had positive effect on chitinase production while SDS decreased the chitinase production by S. marcescens JPP1.

Abstract: In situ monitoring of nitrate in respect of improvement of accuracy becomes more and more important. The direct spectrophotometer analysis of aqueous nitrates is a simple analytic procedure but prone to interferences. In order to solve this problem, the Least Area Value (LAV) Model for in situ determining nitrate in the ocean is reported. The absorbance response of the LAV model varies linearly with concentrations.Calculations of it are in excellent much higher accuracy than conventional measurement models.And more, it solves the problem without the need to measure the dark current first. This eliminated errors due to changes in the dark current during periods shortly after the instrument was turned on. The noise is nearly random and significant reductions in the detection limit are possible by averaging multiple observations in this model. The measurements were directly taken after dilution of the samples between 0.1μmol/l and 400μmol/l.The model was checked on and applied to real samples .The results show that this approach is suitable for routine field measurements of nitrate, which has achieved the precision of 99% and the stability of 99.5%. The model is simple, rugged. The precision, accuracy and stability of the concentrations are sufficiently used to support for many studies.

Abstract: An accurate and sensitive method has been developed for the determination of PCBs in water by gas chromatography coupled with mass spectrometry (GC/MS) with ionic liquid based headspace single-drop microextraction under ultrasound. The sample injection part of gas chromatographic instrument was modifed to avoid the ionic liquid leaking, selected 1-butyl-3-methylimidazolium hexafluorophosphate ([C₄MI[PF₆]) as extracting agents. Experimental parameters influencing the extraction performance, such as desorption temperature, ultrasound extraction time, extraction temperature, ionic liquid headspace volume and salt effect, were optimized. Calibration curve was linear within the range of 10~300.0 μg/L, and the extraction recoveries with RSD values lower than 9.1% were from 77.6% to 103.3%. The limits of detections (LOD), calculated on the basis of signal-to-noise ratio of 3 (S/N=3), was in the range of 0.005~0.007 μg/L. This method is found to be simple, sensitive, little interferential and good specificity for the determination of trace PCBs in water. Real sea sample was successfully analyzed using this method.

Abstract: Two Rumex japonicus populations, one from copper (Cu) mine and the other from uncontaminated site, were studied for root morphology and biomass under Cu stress. Main root length and number of tips of the two populations were both significantly inhibited by Cu treatments. However, those of metallicolous population (MP) were higher than non-metallicolous population (NMP) under Cu stress. Cu treatments significantly inhibited root surface area in NMP while MP showed little difference from control. Cu treatments inhibited average root diameter and root/shoot ratio in NMP, but those in MP were significantly higher than control. Cu treatments significantly inhibited shoot biomass and root biomass in NMP. These results suggested that more assimilates allocated to root and the average root diameter increased under Cu stress to form a greater and stronger root might be partly reasons why R. japonicus can colonize the Cu enriched soils.

Abstract: Ca and Mg in soil are essential nutrient elements for plants, and their exchangeable state is mainly effective. This paper studied the characteristic of statistics, distribution and exchangeable Ca/Mg for Chinese herbs plantation base soil of Yunnan Baiyao Group Co.LTD. The results of 214 soil samplings data show that 93.55% soil samplings of exchangeable Ca content were above 800 mg/kg, so the Baiyao base soil was rich in Ca element. 79.44% of the samples were seriously potential Mg deficiency. The moderate exchangeable Ca/Mg (between 5 and 10) accounts for 41.1%. Baiyao base soil with higher exchangeable Ca and Mg mainly distributed in southwest and north parts, and exchangeable Mg content in the southeast corner was also higher.