[Comparison of shaping ability of 4 nickel-titanium rotary instruments in preparation of curved root canals].

Prupose: To compare the shaping ability of 4 nickel-titanium rotary instruments in preparation of curved root canals.

Methods: Forty extracted human maxillary first or second molars with mesiobuccal root canal curvature ranging from 20°-40° were selected. The teeth were randomly equally divided into 4 groups(n=10).

Response of phytoplankton assemblages to nitrogen reduction in the Laizhou Bay, China.

The response of phytoplankton assemblages to decreases in nitrogen loading is an essential index to assess the recovery of aquatic ecosystems from eutrophic status. However, a positive signal is hard to observe from short-term operations considering ecosystem complexity. Here, we used decadal data from the Laizhou Bay, China to track the seasonal and annual variations in phytoplankton assemblages after ammonia reduction in the Xiaoqing and Yellow Rivers.

Application of a bacterial whole cell biosensor for the rapid detection of cytotoxicity in heavy metal contaminated seawater.

A toxicity biosensor Acinetobacter baylyi Tox2 was constructed with the host strain A. baylyi ADP1 harboring a new and medium-copy-number plasmid pWH1274_lux, and was applied to detect the cytotoxicity of heavy metal contaminated seawater. The gene cassette luxCDABE was controlled by constitutively expressed promoter P on pWH1274_lux and the bioluminescence intensity of the biosensor reduces in proportional to the concentrations of toxic compounds.

Seasonal and spatial variation of Deuteromycetes population in polluted cost of Kiaochow Bay.

Objective: To reveal the relationship between Deuteromycetes community and the environmental in Kiaochow Bay of the Yellow Sea.

Methods: Using recorded pollution survey, we used molecular methods to study seasonal and spatial variation of Deuteromycetes community diversity in different polluted waters of Kiaochow Bay of the Yellow Sea, China.

Results: Denaturing gradient gel electrophoresis fingerprints varied obviously among different sites of similar level of pollution.

Molecular detection of Penicillium griseofulvum as the coastal pollution indicator.

Molecular methods were carried out to detect Penicillium griseofulvum, a dominant species related to heavy metal pollution, which was screened from marine contaminated sediments. Based on differences in internal transcribed spacer (ITS) sequences of Penicillium genus and specific isoamyl alcohol oxidase (IAO) sequences, species-specific primers AS1/RS4 and IAO1/IAO2 of Penicillium griseofulvum were designed and synthesized which were then employed in optimized PCR systems. The detection sensitivities were compared through ordinary PCR and nested-PCR using two pairs of primers, respectively.