Biomedical subjects

Peijun Li

Publications and source records attributed to Peijun Li.

27 records · Page 2Linked to original sources

PubMed2003

[Application of terrestrial invertebrates biomarkers in soil pollution ecology study].

Biomarkers in terrestrial invertebrates play an important role in estimating either exposure or resultant effects of pollutants in soil ecosystem, which has received increasing attention and made significant progress. The present paper has drawn three important biomarkers, i.e., lysosomes, stress protein and mettllothioneins (MTs). The lysosomal membrane stability of coelomocytes was assayed as neutral-red retention time (NRR-time) resulting from toxicant stress. Hsp70 and Hsp60 were commonly used in the stress protein families. The quantification methods of different isofoms of the mettllothioneins could specifically indicate different metal contamination. The rationale, characteristics, and relevant exemplary case of assaying the biomarkers and their promising application to ecotoxicological diagnosing in soil contamination were discussed.

Animals↗

PubMed2002

[Chlorobenze-stressing injury of the germination of soybean seed].

Effects of various doses of 1,2,4-trichlorobenze on seed germination and seedling growth of soybean were studied. The results indicated that 50-200 micrograms.g-1 of 1,2,4-trichlorobenze had no effect on the percentage of seed germination, but delayed the rate of seedling growth. The seed germination was stopped by 300 micrograms.g-1 of 1,2,4-trichlorobenze. The most activity of SOD took place on the 4th day after sowing of soybean seed in the normal condition, then tended to be in a certain level with a little alteration. Under the various dose stress of 1,2,4-trichlorobenze, the activity of SOD in soybean hypocotyl was decreased, while MDA and protein contents as well as diameter of hypocotyls increased. Seedlings growth, fresh weight(FW), dry weight(DW) were inhibited, while the ratio of FW/DW didn't change. Damage-level of wheat seedlings was increased with increasing 1,2,4-trichlorobenze concentrations. Roots were more sensitive to 1,2,4-trichlorobenze-stress than hypocotyls.

Chlorobenzenes↗

PubMed2002

[Bioremediation of PAHs contaminated soil using bio-slurry reactor process].

Studies on bioremediation of PAHs contaminated soil were carried out using bio-slurry reactor process. Phenanthrene (PHE) and pyrene (PY) were chosen as the test pollutants. The results showed that the physical and chemical properties of the pollutants were key factor affecting the bio-remedying possibility of PAHs in soil. PAHs with less benzene rings and lower molecule weight were easier to be biodegraded. So, phenanthrene had higher bio-remedying possibility than pyrene. Temperature and airflow were important control factors in bio-slurry reactor process. In this research, the optimized parameters were operating temperature as 20-30 degrees C, ratio between water and soil as 2:1, airflow as 8 L.h-1.L-1, and the inoculating amount as 50 g.kg-1.

Air↗

PubMed2002

[Toxicity assessment of soil contaminated by heavy metals using algae growth inhibition test].

Scenedesmus obliquus growth inhibition test was carried out to assess the toxicity of soil contaminated by heavy metals. The results showed that the growth rate of Scenedesmus obliquus was positively related to the concentration of heavy metals added to soil, and it was decreased with the increasing concentration of heavy metals. Two parameters were chosen and the sensitivities were compared. It was found that the cell growth rate was more sensitive than OD growth rate. The orders of general detection limit by EC50 of different metals were Pb > Cu > Zn > Cd by using cell growth rate as the test index and Pb > Cu > Cd > Zn by using OD as the test index. This study also indicated that under the complex pollution condition, the toxicity of heavy metals in soil was stronger than that in the case of soil contaminated by single metal.

Cadmium↗

PubMed2002

[The degradation of phenanthrene and pyrene contaminated soil with immobilized technique].

The phenanthrene and pyrene contaminated soil was degradaded by immobilized-imbedding the selected Zoogloea sp. The degradation rate was determined under various amounts of inoculation and concentration, and the result showed that there was the best degradation rate at 5%. After 168 h, the degradation rate of immobilized Zoogloea sp. to phenanthrene and pyrene was 84.89% and 76.94% respectively. While, the degradation rate of the native bacterium was only 27.85% and 19.65% at the same condition. So the Zoogloea sp. had the better degradation ability. And, Zoogloea sp. distributing shape in immobilized carrier was studied with electric scan-photo, it inferred that immobilized bacterium had the better degradation rate.

Environmental Pollution↗

PubMed2002

[Ecological reconstruction of large opencut coal mine through ectomycorrhizal biotechnology].

Pot experiment with discarded greenish mudstone from large opencut coal mine as test soil was conducted to study the application of ectomycorrhizal fungi in the ecological reconstruction of fragile ecological belt of large opencut coal mine of Huolinhe region, Inner Mongolia. The result showed that after the greenish mudstone was inoculated with ectomycorrhizal fungi, the rates of seedling infection and survival were 1.21-2.78 higher in treatment with no fertilizer application than in that with fertilizer application. The test ectomycorrhizal inoculum 010, A and B had a stronger regulation ability in infertile and low penetration coefficient soil. The ammonification of the mudstone could improve its physical and chemical properties, but shorten the survival duration of seedling on account of the accumulation of ammonia and phosphorus in it.

Ammonia↗

PubMed2002

[Effects of aromatics on the degradation of benzo(a) pyrene in slurry reactors].

Benzo(a) pyrene (BaP) can't be biodegraded in the soil easily, the degradation of BaP is know as a cometabolic process. This paper dealed with the effects of some polycyclic aromatic hydrocarbons (PAHs) and two kinds of monoaromatics on the degradation of BaP. The test soil was pre-incubated with the aromatics for 3d and spiked with BaP stock solution, which eventually formed into slurry system in Erlenmeyer flasks and was incubated on rotary shaker. 42 d experiment demonstrated that lag period in degradation process of BaP disappeared due to the preexposure to phenanthrene, and degradation rate of BaP was enhanced. On the contrary, degradation pattern of BaP was not obviously improved by the preexposure to anthracene or pyrene, and was even inhibited by benz(a) anthracene. The lag period also disappeared after the preexposure to salicyclic acid or phthalic acid, and the degradation of BaP was accelerated by both monoaromatics, even though the impact of mass difference on the degradation of BaP was not detected.

Benzo(a)pyrene↗

PubMed2002

[Bio-remediation techniques of crude oil contaminated soils].

The bioremediation of soils contaminated by different types of petroleum were carried out with composting process in a prepared bed. By the measures of nutrient- and microbiological agent addition, and moisture- and pH control, an ideal environment for microbes were obtained. When total petroleum hydrocarbons, which consist of thin oil, high condensation oil, special viscous oil, and viscous oil, were in the range of 25.8-77.2 g.kg-1 dry soil, the petroleum removal rate could reach 38.37-56.74% by 2 months operation. The contents of aromatic hydrocarbon, asphaltum and resin were important factors controlling the degradation of petroleum. 6 fungi, 6 bacteria and 1 actinomyces were found to be the dominant strains for petroleum degradation. The results could provide theoretical bases for remediation of soil contaminated by petroleum.

Bacteria↗

PubMed2002

[Effects of 1,2,4-trichlorobenzene stress on active oxygen in germinated soybean seeds].

Pot culture experiment on the effects of 1,2,4-trichlorobenzene (TCB) stress on active oxygen metabolism of germinated soybean seeds indicated that during the beginning (1st-3rd day) of 100-300 micrograms.g-1 TCB treatment, the respiratory peak appeared earlier, and the respiratory rate, the accumulation of superoxide radical (O2-.) and H2O2, as well as the malondialdehyde (MDA) content were all enhanced. During 1-6 days of TCB stress, peroxidase (POD) activity gradually increased, and superoxide dismutase (SOD) activity increased firstly, and decreased afterward. These results suggested that the injury effects of TCB stress on germinated soybean seeds were achieved by excessive accumulation of active oxygen resulted from the degradation of active oxygen scavenging enzyme system.

Chlorobenzenes↗