[Effect of Root Iron Plaque on Norfloxacin Uptake by Rice].

In anaerobic condition, release of oxygen by roots to rhyzosphere caused the formation of red plaque of iron oxides or hydroxides on the root surface of rice. The effect of iron plaque on norfloxacin uptake was investigated with solution culture in greenhouse, and the results are showed in the following. The content of iron plaque increased with the increase of Fe2+ concentration in medium.

Genetic variability of Echinococcus granulosus from the Tibetan plateau inferred by mitochondrial DNA sequences.

To analyse genetic variability and population structure, 84 isolates of Echinococcus granulosus (Cestoda: Taeniidae) collected from various host species at different sites of the Tibetan plateau in China were sequenced for the whole mitochondrial nad1 (894 bp) and atp6 (513 bp) genes. The vast majority were classified as G1 genotype (n=82), and two samples from human patients in Sichuan province were identified as G3 genotype. Based on the concatenated sequences of nad1+atp6, 28 different haplotypes (NA1-NA28) were identified.

[Degradation pathways and main degradation products of tetracycline antibiotics: research progress].

Tetracycline antibiotics (TCs) can produce a series of abiotic degradation reactions in the process of production and storage, and some of the degradation products have lower antibacterial activity but higher toxicity, as compared to the parent antibiotics. TCs can enter the environment via the disposal of livestock and poultry wastes, and then degrade in one or more ways according to the external conditions. Besides abiotic degradation, bio-degradation also happens.

[Effect of soil organic matter and cadmium (II) on adsorption and desorption of chlortetracycline in soil].

Chlortetracycline (CTC) has been widely used in veterinary medicines and disease treatment. Heavy metals and antibiotics often coexist in soil due to land application of animal wastes and other sources of inputs. On the basis of the OECD Guideline 106, the batch equilibrium experimental method was employed to investigate sorption and desorption processes of CTC in cinnamon soil with and without soil organic matter (SOM) and examine the effect of Cd2+ on these processes.

[Influences of cation species on adsorption and desorption of oxytetracycline in two typical soils of China].

On the basis of the OECD Guideline 106, batch sorption methods were employed to reveal the effect of different cations (0.01 mol x L(-1) Ca2+, K+ and Na+) on oxytetracycline (OTC) adsorption and desorption process in two tested soils (cinnamon soil and red soil). Results show that the Freundlich model is the best isotherm to describe the experimental data of adsorption and desorption, and the average fitting correlation coefficient is 0.

[Dynamic changes of nitrogen forms in livestock manure during composting and relevant evaluation indices of compost maturity].

In this paper, the dynamic changes of nitrogen (N) forms in different livestock manures were investigated during composting, and the relevant N evaluation indices of compost maturity were approached. The results indicated that during composting, the total nitrogen (TN) concentration in dairy cattle manure increased first and became steady then, but in other five test manures, it decreased first and became steady then. For all test manures, their hydrolizable nitrogen (HN) decreased after an initial increase, NH4(+)-N decreased first and became steady then, while NO3(-)-N had a persistent increase.