Response of photosynthetic characteristics and non-structural carbohydrate accumulation of seedlings to drought stress.

We explored the effects of drought stress on photosynthetic characteristics and non-structural carbohydrate (NSC) accumulation of the timberline tree species in Changbai Mountain with a drought control experiment. The results showed that drought significantly reduced the net photosynthetic rate and stomatal conductance, but increased water use efficiency (WUE) of seedlings. Drought dramatically improved the contents of soluble sugar and total NSC in leaves, barks, stems, and roots of seedlings, but significantly reduced their starch content.

Mesostructured tin oxide as sensitive material for C(2)H(5)OH sensor.

Mesostructured tin oxide with high specific surface area was synthesized using cationic surfactant (cetyltrimethylammonium bromide, CTAB: CH(3)(CH(2))(15)N(+)(CH(3))(3)Br(-)) as the organic template and hydrous tin chloride (SnCl(4).5H(2)O) and NH(4)OH as the inorganic precursors under acidic conditions at ambient temperature. Thermogravimetric analysis (TGA), Fourier transformed infrared (FTIR), X-ray diffraction analysis (XRD), X-ray photoelectron spectrum (XPS) and N(2)-sorption isotherms were used to characterize the mesostructured tin oxide that was formed at room temperature as well as calcined at different temperature.

[Study of adherence of normal oral bacteria on polymethyl methyacrylate containing silver-supported silicate inorganic antibacteria].

Objective: To study the oral normal bacteria adherence on polymethyl methyacrylate (PMMA) containing silver-supported silicate inorganic antibacterial, and the growth inhibitory concentration of silver-supported silicate inorganic antibacterial to normal oral bacteria were also investigated.

Methods: A certain volume of normal oral bacteria was inoculated on the RHI plate containing different dilution of silver-supported silicate inorganic antibacterial, then the growth of the bacteria was investigated by light microscope and biochemical methods; the oral bacteria plaque model in vitro was used to evaluate the adherence of 4 species normal oral bacteria mixture on the surface of PMMA which containing silver-supported silicate inorganic antibacterial in the proportion of 5% or 10%.

Results: The growth of normal oral bacteria was inhibited effectively by silver-supported silicate inorganic antibacterial within the concentration of 8%, and the growth of Porphyromonas gingivalis and Conclida albicans were inhibited at concentration from 1.