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Syntheses and crystal structures of aroyl-hydrazone ligands and their transition metal complexes (E)-N′-(2-hydroxybenzylidene)-1-methyl-4-nitro-1H-pyrrole-2-carbohydrazide (H21), [CuII(H1)Cl] (2), [FeIII(H1)Cl2(MeOH)] (3), [MnIII(1)(μ-OMe)(MeOH)]2 (4), [VVO(1)(OMe)] (5), Et3NH[VVO2(1)] (6), [CoII(H1)(μ-Cl)(H2O)]2 (7) and [CoII(1)2] (7′) are reported in this paper. The binding abilities of the compounds with calf thymus DNA are measured by using UV–Vis and fluorescence spectra. The apparent binding constant (Kobs = (1.66 ± 0.21) × 104 M−1) and rate constant (kobs = 3.62 ± 0.17 h−1) of 2 with CT-DNA is calculated, respectively. The quenching constants (Kq) 3.52 × 104 for 3, 1.97 × 104 for 4, 5.94 × 103 for 2, 3.32 × 103 for 7, 1.64 × 103 for 5, 1.55 × 103 M−1 for H21 are determined, respectively, using ethidium bromide, as fluorescence probe. Agarose gel electrophoresis studies indicated that the complexes cleave plasmid pBR322 DNA by a hydrolytic mechanism.

The interaction between N,N'-ethylenebis-[2-(o-hydroxyphenolic)glycine] (EHPG) and lanthanum was studied by the difference UV spectra and fluorescence spectra. At pH 7.4, 0.01 M N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (Hepes), with the addition of 1.0 x 10(-3)M lanthanum, two new peaks were observed at 238 nm and 294 nm by absorptivity spectroscopy compared with blank solution EHPG suggesting the interaction of lanthanum and EHPG. At the same time, the reaction could be measured by fluorescence spectra. The fluorescence intensity of EHPG at 310 nm was significantly decreased in the presence of lanthanum. The 1:1 stoichiometric ratio of EHPG to lanthanum was confirmed by both fluorescence and UV titration curves. In addition, the molar absorptivity of La-EHPG at 238 nm is (1.23+/-0.01)x10(4)cm(-1)M(-1). The conditional binding constant was calculated to be log K(La-EHPG)=12.09+/-0.37 on the basis of the result of UV titration curves.

This paper presents a novel scheme of news video story segmentation with the combination of topic caption frame and audio information. First of all, a new method of topic caption frame detection is proposed in which the topic caption frame is detected by features extraction from frame differences, the topic caption lasting time and times of caption transition in the same shot. Afterwards, the silence clip between two continuous news story boundaries is detected according to short-time average energy and short-time average zero-crossing rate. Moreover, one news video is segmented into a series of news story clips on the basis of topic caption text and silence clip. The experimental results showed that the proposed method could effectively detect topic caption text and news story clip boundaries for news video.

This paper presents a novel scheme for news video structure indexing and news story clip retrieving. Instead of using low-level features, the method is built upon the combination of topic content and visual features. First of all, a new method of topic caption text detection is proposed in which the topic caption frame is detected by features extraction from frame differences, the topic caption lasting time and times of caption transition in the same shot, and the dynamic split-merge strategy is used to segment individual character. Afterwards, one news video is segmented into a series of news story clips on the basis of topic caption text and silence clip. Finally, a reasonable model is built to retrieve news story clips by both visual similar degree and topic content relativity between two news clips with strong semantic meaning. The experimental results showed that the proposed method could effectively detect and recognize topic caption text and index news story clips.

Centrin is a member of the EF-hand superfamily that plays critical role in the centrosome duplication and separation. In the present paper, we characterized properties of metal ions binding to Euplotes octocarinatus centrin (EoCen) by fluorescence spectra and circular dichroism (CD) spectra. Changes of fluorescence spectra and α-helix contents of EoCen proved that Tb 3+ and Ca 2+ induced great conformational changes of EoCen resulting in exposing hydrophobic surfaces. At pH 7.4, Ca 2+ (and Tb 3+ ) bond with EoCen at the ratio of 4:1. Equilibrium experiment indicated that Ca 2+ and Tb 3+ exhibited different binding capabilities for C- and N-terminal domains of protein. C-terminal domain bond with Ca 2+ or Tb 3+ ∼ 100-fold more strongly than N-terminal. Aromatic residue-sensitized Tb 3+ energy transfer suggested that site IV bond to Tb 3+ or Ca 2+ more strongly than site III. Based on fluorescence titration curves, we reckoned the conditional binding constants of EoCen site IV quantitatively to be K IV = (1.23 ± 0.51) × 10 8 M −1 and K IV = (6.82 ± 0.33) × 10 5 M −1 with Tb 3+ and Ca 2+ , respectively. Metal ions bond to EoCen in the order of IV > III > II, I.

Glu is highly conserved as the first amino acid of E-helix of the EF-hand protein. In this paper, Glu 101, the first amino acid of E-helix of the third EF-hand motif in Euplotes octocarinatus centrin (EoCen) was mutated to be Lys by the method of site direct mutation. Tb3+ and TNS were used as fluorescence probes in the study of the effect of this mutation to the metal binding characteristic of EoCen by fluorescence spectra. Results indicate that compared with EoCen, the mutation protein (E101K) displays a different Tb3+ binding characteristic and an increased hydrophobic exposure surface. Polyacrylamide gels electrophoresis indicated that the electrophoretic mobilities of EoCen and E101K are distinctly different. It can be deduced that the conformation of EoCen has been altered by this mutation. The general conditional binding constant of Tb3+ to the three loops of EF-hand sites I-III in E101K was calculated to be (5.64+/-0.57)x10(5)M(-1) according to the modified equation of the single binding process.