Biomedical subjects

Qixing Zhou

Publications and source records attributed to Qixing Zhou.

At least 55 records · Page 3Linked to original sources

PubMed2004

[Progress in pollution ecology of soil-plant systems and its expectation].

In order to promote the further healthy development and disciplinary construction of the rising discipline pollution ecology of soil-plant systems and give full play to its more and more important role in solving environmental pollution and food-chain safety at the national level, this paper reviewed the inceptive work and early researches in this scientific area, traced the development of disciplinary definition and connotation, and basic principles and methods, and expounded and prospected the scientific mission, principal research contents and future development of this subject.

Crops, Agricultural↗

PubMed2004

[Influence of acetochlor on Pb forms and their bioavailability in phaiozem of northeast China].

By using Pb-fractionation analytical methods and Pb-acetochlor response experiments, it was studied the Pb forms in clean and polluted phaiozems of northeast China and the response of Pb bioavailability to acetochlor application. The results showed that the dominant Pb forms in these soils were low bio-available organic-sulfide Pb and residual Pb, and the concentrations of high bio-available water-soluble and exchangeable Pb were relatively low. However, the ratio of bio-available Pb to total Pb was lower in polluted phaiozem than in clean phaiozem. The bioavailability of Pb in the soil was obviously increased after high dose of acetochlor was applied. The main reason was the contribution of organic-sulfide Pb to bio-available Pb interacted with acetochlor.

Biological Availability↗

PubMed2004

[Effects of long-term fertilization on soil microorganism and its role in adjusting and controlling soil fertility].

To clarify the relationships between soil microorganisms and soil fertility under the condition of long-term fertilization, a 12-year fertilization experiment was installed on a fluvo-aquic soil, and the amount of soil microorganisms and the content of soil nutrients were determined and analyzed. The results showed that chemical fertilizers combined with organic manure could significantly improve soil fertility and increase the amount of soil microorganisms. Organic manure was obviously superior to corn straw in improving soil fertility. The correlation between soil microorganisms and soil fertility was significant. A positive correlation was found between the amount of bacteria and azotobacteria and the contents of organic matter, total N, alkalified N, total P and available P. The relationship between the amount of fungi and actinomycetes and the content of soil nutrients was not obvious.

Actinobacteria↗

PubMed2004

[Accumulation of pollutants in sediments and their eco-toxicity in the wastewater irrigation channel of western Shenyang].

Sediment samples were collected from several sites in the upper, mid and lower reaches of the petroleum wastewater irrigation channel in western Shenyang of China, and the concentrations of their heavy metal Cd and mineral oil were determined. The results showed that pollutants were accumulated in all test sediments, with 400-12,500 mg x kg(-1) mineral oil and 1.6-27.2 mg x kg(-1) Cd. The sediments had significant inhibition effects on plant and earthworm. The inhibition rate of root elongation based on germination test was 10%-60%. During 14 d and 28 d exposure, the mortality rate of earthworm was 0%-70% and 0%-85%, and the inhibition rate of its body weight growth was -21.9%-17.7% and -18.6%-37.0%, respectively. It indicated that a long-term irrigation with wastewater resulted in the accumulation of pollutants in channel sediments and enhanced eco-toxicity. As an important source of pollution, the migration and release of pollutants in sediments possessed potential risks to underground water and soil.

China↗

PubMed2004

[Soil nematode as a bioindicator of environment pollution].

As a part of mesofauna in soil ecosystem, nematode plays an important role in essential soil processes. Because of its unique attributes, nematode was widely used in the study of soil health indication. Based on the current studies at home and abroad, this paper discussed the function and application of nematode in indicating and diagnosing soil pollution, and the indices (maturity index, diversity index, similarity index, key species, N/C ratio, and physiological index) and their characteristics of nematode communities used as indicators. As a useful index of bioindicators in ecotoxicological diagnosis, the prospect of soil nematode application was of potential.

Animals↗

PubMed2004

[Bio-indicating function of soil protozoa to environmental pollution].

Due to the abundant species and huge biomass, soil protozoa play an important role in soil ecosystem. As a bio-indicator, soil protozoa have many advantages over other soil animals. Studies on the community structures, quantities, and dynamic variations of biodiversity of soil protozoa could provide powerful means to evaluate natural environmental changes and to monitor the environmental pollution brought by anthropic activities. Based on the current study at home and abroad, this paper gave a review on the function of soil protozoa in ecosystems, their advantages as bio-indicator, and their responses to environmental factors, soil contaminants and the change of atmospheric CO2. The application prospect of soil protozoa in eco-toxicity diagnosis was also discussed.

Animals↗

PubMed2004

[Research advances in DNA adducts: their formation, diagnosis and pollution-exposure indication].

With the cognitive penetration of ecotoxicological effects into a molecular level, more attention has been paid to the research on DNA adducts. This paper analyzed toxic mechanisms and formative processes of DNA adducts, and introduced in brief their diagnostic methods, including chromatogram-mass spectrum method, 32P post-labeling method, immunology method and fluorescence method. The pollution-exposure indication of DNA adducts was expounded as an effective molecular biomarker, and thus, DNA adducts could be used by ecotoxicologists as a good caution signal in forecasting hazardous effects of pollutants.

Biomarkers↗

PubMed2004

[Response of soil-wheat ecosystem to soil magnetization and related ecological indicators].

By using outdoor pot-culture method combined with biological magnetic effect analysis, this paper studied the effect of soil magnetization on soil-wheat ecosystem health. It was showed that there was an improvement in soil-wheat ecosystem health after soil magnetization, e.g., the germination of wheat seeds promoted, and the seedling height, individuals of leaves and roots, overall and active absorption area of roots and their absorption rates, and biological yield of mature wheat were increased. The ecological indicators of magnetic health effect were also discussed. 200 mT was the best parameter of magnetic treatment for wheat growth.

Ecosystem↗

PubMed2003

A risk factor analysis of municipal domestic refuse landfills using a reactor with high water input.

Collapse, explosion and water pollution by leachate have been three major problems in confining the development of sanitary landfilling technology as an economical method for disposal of municipal refuse. Potential risk factors including settlement of landfilled refuse, the generation of methane, carbon dioxide and other gases from landfill, the dynamic changes in temperature within the landfill and its ambient environment, as well as COD(Cr), BOD5, nutrients (TKN, TP and organic matter), heavy metals (Cu, Pb and Zn) and pH in landfill leachate were simulated using a reactor with high water input. It was indicated that high content of organic components in landfilled refuse is a key risk factor to cause abrupt collapse and accidental explosion in the landfill because they have impact not only on the settlement, but also on the release of methane and other gases. Elevated temperatures coincided with maximum generation of methane and other gases, thus increasing the risk of accidental explosion. Leachate quality was closely related with the release of COD(Cr) and BOD5 and heavy metals such as Cu, Pb and Zn, as well as organic pollutants, there was less release of TKN and TP. The mass balance analysis for the reactor showed that 36% of organic carbon reduction in the refuse during the simulations was discharged into leachate as soluble organic carbon, and 3% was converted to methane and carbon dioxide as gas production. Mixing of refuse with soil and sand particles, the so-called drill-a-hole method and recycling leachate were measures suggested in order to mitigate and avoid potential accidents.

Carbon Dioxide↗

PubMed2003

[Roles of rhizosphere in remediation of contaminated soils and its mechanisms].

Rhizosphere is a special 'ecological remediation unit' to treat contaminated soils, which contains a great quantity of microorganisms such as fungi and rhizobacteria living with plant roots. Thus, physiological and ecological roles of plant roots to remedy contaminated soils, to accumulate and to solidify heavy metals, to absorb and degrade organic pollutants in rhizosphere were illustrated, and the function of mycorrhizospheric fungi to absorb, barrier and chelate heavy metals, to degrade organic pollutants through their metabolism activities, the action of rhizobacteria to absorb and solidify heavy metals, to degrade organic pollutants in rhizosphere through their active living activities, and the combined remediation of fungi and bacteria to pollutants in rhizosphere and their relevant mechanisms were explained. It was suggested that the remediation role of rhizosphere was the main part of phytoremediation, and one of the main basic theories to remedy contaminated soils by the activity of green plants and other organisms. The use of hyperaccumulative plants in remedying soils contaminated by some heavy metals would be prospective. It would be one of the important approach to contaminated soils remediation by organic pollutants through the mechanism of screening some special plants whose roots had strong secreting ability to absorb and accumulate dissolvent organic pollutants on the basis of inoculating specific or non-specific fungi and bacteria from the rhizosphere. This will be a developing trend of research on the remediation of contaminated soils by organic pollutants.

Bacteria↗

PubMed2003

[Endurance and mechanisms of soil urease and dehydrogenase exposed to reactive X-3B red dye contamination].

Endurance and mechanisms of urease and dehydrogenase in three Chinese typical soils (burozom, cinnamon soil and red soil) exposed to the contamination of reactive X-3B red dye were experimentally studied using the microcosmic method. The results indicated that the activities of urease and dehydrogenase were both promoted in the three soils by reactive X-3B red dye in low dose, 500 and 1000 mg/L although the stimulating intensity was different from each other. For one thing, the activity of urease in burozom was promoted mostly followed by that in red soil and that in cinamon was promoted most weakly. For the other, reactive X-3B red dye in the same concentration could increase the activity of dehydrogenase in cinnamon soil most greatly and in burozom most weakly. However, the stimulating intensity of urease and dehydrogenase activities in the three soils was more and more fainter with the extension of days. Furthermore, reactive X-3B red dye in high concentration (3000, 5000 and 10,000 mg/L) could not inhibit the activities of urease and dehydrogenase in tested soils. On the contrary, all of them remained the level of the activities in unpolluted soils and no toxicity of reactive X-3B red dye could reveal with time. Therefore, both enzymes in three types of soils had the tolerance to reactive X-3B red dye. Based on the experimental data, relevant endurant mechanisms were also analyzed and discussed.

Coloring Agents↗

PubMed2003

[Effects of land utilization of sewage sludge on grass and soils].

Effects of land disposal of sewage sludge on grass and soil environment were studied. The sewage sludge used was from Northern Shenyang Wastewater Treatment Plant. The results showed that contents of nutrient in the soil were increased after sewage sludge application, especially for organic matter. Grass biomass were increased and the green period were extended with a better growth of the lawn. The heavy metal contents in the soil were increased with Cd contents beyond 2nd grade national environmental quality standard for soils. However, Pb, Cu, Zn contents not accumulated heavily. Poa annua had better ability of absorbing and accumulating Pb from the sewage sludge. When the application rate of sewage sludge capacity was at 25, 30, 60 t.hm-2, Zoysia japonica expressed significant absorption and accumulation of Cd, Cu, Zn.

Agriculture↗

PubMed2003

[Introduction and progress of molecular microbial ecology].

Molecular microbial ecology is an interdisciplinary field of molecular biological techniques and microbial ecology, which deals with microbial population, diversity, function, and relationships between microorganisms and biotic and abotic environments in microbial ecosystem. All the progress in molecular microbial ecology, especially in microbial diversity, phylogeny and communities of some microoganisms, indicate the renovation in traditional microbial ecology by the introduction of molecular techniques and strategies. This article reviewed the ideation, development, key domains, main methods and the future hot fields in molecular microbial ecology.

Ecology↗

PubMed2003

[Effects of combined pollution of heavy metals on root vitality of wheat seeds].

The combined effects of Cu, Cd, Pb and Zn on the growth and activity of the seminal roots of wheat (Triticum aestivum) were studied by the method of quadratic regression revolution design. The mathematical models describing the above relations were established. As for the toxicity to the root vitality, their single effects, marginal utility and combined effects between two heavy metals were analyzed. The results showed that Pb had the most important effect on the activity of root, and then, Cu, Cd and Zn in sequence. The interaction between Cu and Cd, Cu and Zn, Zn and Cd, Cd and Pb had great effects on the activity of seminal roots. Furthermore, among the concentration range of 0 to 20 mg.L-1, as for Cu and Zn, the lowest density had the biggest marginal utility, while Cd and Pb had the biggest ones at the highest density.

Metals, Heavy↗

PubMed2003

[Effect of short-term phenanthrene stress on SOD activities and MDA contents in soybean (Glycine max) seedlings].

Growth of soybean (Glycine max) seedlings, changes of superoxide dismutase (SOD) activities, and malonyldialdehyde (MDA) contents were researched during different concentration phenanthrene stress and following recovery from stress. The results showed that seedling growth was interrupted after 5 d in 200 micrograms.g-1 phenanthrene treatment. However, during the period of recovery, growth was restored, although there was a delay in returning to control levels. The dose-related response of SOD activities were observed in manner of linear for 2 d and of parabola for 5 d and 8 d at 50-200 micrograms.g-1 phenanthrene. SOD activities of seedling were significantly induced by 100 and 200 micrograms.g-1 phenanthrene for 2 d (P < 0.05 and P < 0.01), while declined significantly under phenanthrene stress for 8 d, and was 88% of control at 200 micrograms.g-1 phenanthrene (P < 0.05). When releasing soybean seedlings from phenanthrene stress for 5 d to clear tap water for 2 d or 4 d, their SOD activities at 50 and 100 micrograms.g-1 phenanthrene recovered towards control level, while a significant increase in SOD activities was observed at 200 micrograms.g-1 phenanthrene (P < 0.05). The experiments also revealed that a significant increase of MDA contents in seedlings occurred after 5 d and 8 d in 100 and 200 micrograms.g-1 phenanthrene treatment (P < 0.05 and P < 0.01), which suggested that the membrane systems were damaged by phenanthrene stress. All of the above results showed that SOD activities of soybean seedling might be suitable to be the biomarkers of phenanthrene stress.

Malondialdehyde↗

PubMed2003

[Effects of chlorobenzene stress on seedling growth and cell division of Vicia faba].

Effects of 1, 2, 4-trichlorobenzene (TCB) stress on seedling growth, cell division and chromosomal aberration frequency of root-tip cells of Vicia faba were studied. The results indicated that the growth of the root length and mitotic index of root tip cells were successively decreased and even stopped with the increase of TCB concentrations and treatment duration. Numerical and structural chromosomal aberrations at metaphase and anaphase of root-tip cells in Vicia faba seedlings were produced by 50-300 micrograms.g-1 TCB treatment for 12-96 h. The percentage of c-mitosis, chromosomal bridge and chromosomal asymmetry array in root tip cells exposed to 50-100 micrograms.g-1 TCB for 12-24 h was up to 1.0-10.3%. The percentage of chromosomal stickness (S), chromosomal stickiness + chromosomal breakage (S + B), chromosomal stickness + chromosomal ring (S + R), chromosomal stickiness + chromosomal asymmetry array (S + A) and chromosomal stickness + chromosomal bridge (S + Be) in root tip cells reached 47.9-88.9%, and 18.1-29.6% for different kinds of chromosomal breakage at 300 micrograms.g-1 TCB for 12-96 h. Thus, the chromosomal aberration of root tip cells in Vicia faba seedlings could be used as a sensitive biomarker of monitoring soil contaminated with TCB.

Cell Division↗

PubMed2003

[Single and binary-combined toxicity of methamidophos, acetochlor and Cu on earthworm Eisenia foetida].

A population of earthworm Eisenia foetida was exposed to single and binary-combined contamination of phaeozem by methamidophos, acetochlor and Cu. The result showed that one of three test chemicals had its toxicity on the earthworm population, and the single toxic sequence of the chemicals was acetochlor > methamidophos > Cu. The values of their LD50 were 0.307, 0.708 and 118.70 mg.kg-1, respectively. The difference was depended on the biological mechanisms of the earthworm population. Acetochlor and Cu in soil could be absorbed by the earthworm population through penetrating through the skin of an earthworm. The result also showed that Cu could swell the toxicity of methamidophos, whether it was in low or high concentration by the binary-combined toxic effect test. Cu in low concentration could decrease the toxicity of acetochlor, but in high concentration, Cu could increase the acetochlor toxicity in soil. Therefore, these three pollutants were dangerous to the ecological security of soil ecosystem and soil-health quality. Furthermore, when the chemicals in same soil environment act one another, they could boost up the potential danger of soil ecosystem contaminated by the three pollutants. The joint toxic effects of various chemicals were in relation to their different concentration combinations in soil.

Animals↗

PubMed2003

[Effects of different application dosage of herbicide on rice production].

Investigations on the effects of different application dosage of Machete and Londax mixture to control weeds in paddy fields showed that applied common and double dosage could effectively control weeds, and the controlling effects exceeded 80% and 90%, respectively, while there were some inhibiting effects to height and branch number of rice, and some resistance of weed had appeared. Weed contest might make rice get some compensation in height and branch under the condition that no herbicide and half dosage were applied, but the rice yield was decreased 36.01% and 54.80%, respectively, mainly because of the decrease of the number of effective panicles and grain number per panicle. The narrow economic benefit of the herbicides should be high.

Crops, Agricultural↗