[Study on the characters of phytoplankton chlorophyll fluorescence excitation spectra based on fourth-derivative].

Chlorophyll fluorescence excitation spectra of six phytoplankton species, belonging to Bacillariophyta and Dinophyta, were dealt by fourth-derivative analysis with the Matlab program. The results show that between 350 nm and 550 nm six fluorescence peaks were found in the fourth-derivative spectra, which are representatives of non-pigments, chlorophylls and carotenoides respectively. The method makes Bacillariophyta and Dinophyta more distinguishable when the fourth-derivative spectra are compared with the chlorophyll fluorescence excitation spectra. It can be used not only to discriminate the two groups of algaes, but also to reduce the effect of noise. The fluorescence peaks in the fourth-derivative spectra are proved to be stable.

[Research on characterization analysis of synchronous fluorescence spectra of living phytoplankton].

The synchronous fluorescence spectra of five phytoplankton species growing under three temperatures (25, 20 and 15 degrees C)and three illuminations (7000, 4100 and 1100 Lx)were measured and processed by multinomial smoothness and autoscaling to obtain the characteristic spectra. Principal component analysis was used to obtain standard spectra. The analysis shows that at different temperatures, the characteristic spectra of Skeletonema costatuma, Isochrysis galbana, and Platymonas helgolanidica show high similarities, while the spectra similarities of Alexandrium tamarense and Gymnodinium stein are not as good as the above three species. The standard spectrum of Skeletonema costatuma, which belongs to Bacillariophyta, is quite different from those of Alexandrium tamarense and Gymnodinium stein, which belong to Dinophyta.

Discrimination of phytoplankton classes using characteristic spectra of 3D fluorescence spectra.

The discrimination of phytoplankton classes using the characteristic fluorescence spectra extracted from three-dimensional fluorescence spectra was investigated. Single species cultures of 11 phytoplankton species, representing 5 major phytoplankton divisions, were used. The 3D fluorescence spectra of the cultures grown at different temperatures (20 and 15 degrees C) and illumination intensities (140, 80 and 30 microM m(-2) s(-1)) were measured and their feature extraction methods were explored. Ordering Rayleigh and Raman scattering data as zero, the obtained excitation-emission matrices were processed by both singular value decomposition (SVD) and trilinear decomposition methods. The resulting first principal component can be regarded as the characteristic spectrum of the original 3D fluorescence spectrum. The analysis shows that such characteristic spectra have a discriminatory capability. At different temperatures, the characteristic spectra of Isochrysis galbana, Platymonas helgolanidica and Skeletonema costatuma have high degrees of similarity to their own species samples, while the spectra similarities of Alexandrium tamarense, Prorocentrum dentatum, Pseudo-nitzschia pungens, Chaetoceros curvisetus, Ch. Debilis, Ch. Didymus and Synechococcus sp. are not as significant as the other three species. C. curvisetus, Ch. Debilis and Ch. Didymus, belonging to genus Chaetoceros, have identical spectra and cannot be discriminated at all. Regarding all six diatom species as one class, the average discriminant error rate is below 9%. It is worth mentioning that the diatom class can be distinguished from A. tamarense and P. dentatum, which belong to Dinophyta.

[Characteristics of absorption spectra of phytoplankton].

Nine typical phytoplankton species were chosen and cultivated under two temperatures (20 and 15 degrees C) and two illumi- nations (7000 and 1100 lux), and their absorption spectra at different growth period were measured. Firstly, singular value decomposition was used on the matrix, which is composed of the autoscaled spectra data. The S1/msigma(i=1)Si was used to compare the similarities of spectra. Twenty-five representative spectra were obtained for the nine species of phytoplankton. Among them, there are one spectrum for each of Isochrysis galbana and Chaetoceros Debilis, two for each of Platymonas helgolanidica and Chaetoceros curvisetus, three for Gymnodinium sp., and four for each of Alexandrium tamarense, Prorocentrum dentatum, Skeletonema costatuma and Synechococcus sp. Then, feature extraction was processed to obtain the characteristic spectra, including seven incontinuous wavelengths that have great ability to differentiate species. They are 340. 5-420. 5 nm, 423. 5-431 nm, 440.5-525.5 nm, 760.5, 763.5, 769.5 and 856.5 nm. Consequently, they form characteristic spectra. The discriminant result is 80%.

[Synthesis and DNA binding spectroscopy studies of Cu(II)-Thr-Phen].

A new complex [Cu (Thr)(Phen)H2O] SO4 . HO2 x CH3 OH (Thr = DL-Threonine, Phen = o-Phenanthroline), which has not been published, was synthesized and characterized by elemental analysis, IR spectroscopy, and TG-DTA. The interaction of the complex and sperm DNA was studied by electronic absorption and ethidium bromide (EB) fluorescence spectroscopy. The result indicates that the maximal absorption peaks of this complex are red-shifted and the intensity is weakened; At the same time, it can to some extent quench the emission intensity of EB-DNA system. Therefore, the authors come to a conclusion that the interaction of this complex and sperm DNA is intercalation.

[Distribution and controlling factors of nitric oxide concentrations in surface seawater of Jiaozhou Bay and adjacent waters].

Distribution of nitric oxide (NO) concentrations in surface seawater of Jiaozhou Bay and adjacent waters was studied adopting the chemiluminescence method during February and March 2011. Based on the data of NO concentrations and related environmental parameters in hydrology, chemistry and biology, the distribution and controlling factors were discussed. The results showed that the range and the mean of NO concentrations in surface seawater of Jiaozhou Bay were 0.080-0.493 nmol x L(-1) and (0.292 +/- 0.146) nmol x L(-1), respectively. The concentrations of NO ranged from below detection limit to 0.435 nmol x L(-1) in adjacent waters of Jiaozhou Bay, with the mean of (0.160 +/- 0.130) nmol x L(-1). The concentrations of NO showed a gradually decreasing trend from inside to outside of Jiaozhou Bay, which was possibly due to the effect of terrestrial runoff and human activities. The NO concentration of surface seawater in Jiaozhou Bay and adjacent waters was one order of magnitude higher than that in the open sea. The concentrations of NO in the surface seawater exhibited an obvious diurnal variation. The highest concentration of NO appeared at 15:00, which was presumably due to the effect of illumination intensity. The influencing factors of NO concentration and distribution were complex, including nitrite, pH, light intensity and so on. The present study showed that Jiaozhou Bay and adjacent waters was a source of atmosphere NO in spring,and F(NO) was about 1.09 x 10(-15)mol x (cm2 x s) (-1).

The application and comparison of several chemometric methods of excitation-emission matrix spectra in studying the interactions of metal complexes with DNA.

The interactions of fs DNA and two metal complexes [Cu(phen)SO4] x 2 H2O and [Ni(phen)SO4] x 2 H2O were explored by several chemometric methods, including parallel factor (PARAFAC), singular value decomposition-least squares (SVD-LS), and singular value decomposition-nonnegative least squares (SVD-NNLS) of excitation-emission matrix spectra (EEMs). The applications of SVD-LS and SVD-NNLS in this domain have been discussed. Rayleigh scatter part is avoided by ordered zero and reconstructed by linear interpolation. The importance of avoiding Rayleigh scatter has also been discussed. All the three methods do well in qualitative analysis. SVD-LS does best in present small changes of ethidium bromide (EB). In order to get accurate results, PARAFAC and SVD-NNLS can be utilized together in quantitative analysis. All the three chemometric methods indicate that the DNA binding modes of [Cu(phen)SO4] x 2 H2O are hydrogen bond effect and intercalation, while intercalation is the only DNA binding mode for [Ni(phen)SO4] x 2 H2O. These results are verified by the electronic absorption and emission fluorescence spectra. Just like PARAFAC, both SVD-LS and SVD-NNLS are proven to be convenient and convincing in studying the interactions between nucleic acids and complexes.

[Ecological effect of No.0 diesel water accommodated fraction on marine algae].

With batch culture experiments in field and laboratory, the ecological effect of No. 0 diesel water accommodated fraction on marine algae was studied. A growth model of marine algae under grazing pressure and a model of growth effect on marine algae with different doses No.0 diesel water accommodated fraction were proposed. Based on the model and experiments, the growth effect of No.0 diesel water accommodated fraction on marine algae was studied. The results show that, the growth model of marine algae under grazing pressure is more suited for the marine ecological system than Logistic model. And the final biomass (B(f)) of marine algae with different doses No.0 diesel water accommodated fraction was calculated by the model with none-linear fitting software. The results also show that, under the field and laboratory conditions, lower doses No.0 diesel water accommodated fraction promotes the growth of marine algae, and the most promoting ratio are 180% and 120% respectively, however, higher doses hardly promotes but bates the growth of marine algae.

[Selective algicidal activity of Gemini1231 biquaternary ammonium salt].

The growth-inhibiting effects of Gemini1231 surfactant on Prorocentrum donghaiense, Alexandrium tamarense, Gymnodinium sp., Heterosigma akashiwo, Skeletonema costatum , Platymonas helgolanidica and Platymonas subcordiforus were investigated. The results demonstrate that the growth of P. donghaiense, A. tamarense and H. akashiwo was strongly inhibited in medium containing Gemini1231 from 0.2 to 0.5 mg x L(-1), and the S. costatum was also inhibited at concentrations above 0.5 mg x L(-1). However, the effects of this surfactant on the growth of Gymnodinium sp. and two beneficial green microalgae tested were negligible under the same treatment, indicating the potential for the selective control of red tide organisms. In addition, the analysis of the correlation between the inhibitory effect of the Gemini1231 on the algae tested and fatty acid composition of the algae implied that the differences in the fatty acid composition, especially the proportion of PUFAs, were responsible for the species-specific responses to biquaternary ammonium salt.

[Kinetic model for bioconcentration of No. 0 diesel water-accommodated fraction by phytoplankton].

A "cW (pollutant concentration in water) Balance Method" was proposed, and the kinetic parameters for bioconcentration of No. 0 diesel water-accommodated fraction by phytoplankton was measured and calculated by a modified bioconcentration model with non-linear fitting software. The data and parameters obtained by "cW Balance Method" showed well correlationship with those by the extraction of ultrasonication bath with the equilibrium method. The technique proposed in the present study is particularly well suited for the study on the bioconcentration of organic pollution toxins in the field for its convenience, simplicity, veracity and reliability.