Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculation were adopted to study the structures and properties of metal-free and magnesium tetrathieno[2,3-b]porphyrazine (TTPPzH2 and TTPPzMg) using B3LYP method with the 6–31G(d) basis set. A comparison of the geometrical structures, atomic charges, molecular orbitals, UV-vis spectra and infrared (IR) spectra among tetrathieno[2,3-b]porphyrazine (TTPPzH2), phthalocyanine (H2Pc) and porphyrazine (H2Pz) compounds was performed. The substituent effect of the thiophene heterocycle for electron-donating on the structures and properties of these compounds has been discussed. Compared with other atoms, the charge distribution of Cβ atoms adjacent to the sulfur atom is significantly influenced by the thiophene heterocycle substituents. The enlargement of the HOMO-LUMO gaps from H2Pc and MgPc to TTPPzH2 and TTPPzMg is at the origin of the observed blue shift of the Q band when moving from H2Pc to TTPPzH2 compounds. Special emphasis has been devoted to the strongest B bands for TTPPzH2 compounds which show red shift due to the large destabilization of the lower lying occupied orbitals compared with the corresponding B bands of H2Pc compounds. With the assistance of animated pictures produced on the basis of the normal coordinates, the significant peaks and vibration modes in the IR spectra of all the compounds were assigned and analyzed. 相似文献
Luminol-type compounds can be used as chemiluminescent (CL) derivatization reagents for amines, carboxylic acids and protein. Copper chelate diperiodatocuprate(III) (K5[Cu(HIO6)2], DPC) was synthesized by complexation of copper at trivalent oxidation state and periodate in a strong basic medium. It was found that DPC can greatly enhance the reaction between luminol-type compounds and H2O2 to produce very strong CL emission. Based on this fact, a rapid CE method combined with high-sensitive end-column CL detection was established to simultaneously analyze luminol and N-(4-aminobutyl)-N-ethylisoluminol (ABEI) with wide concentration range of 3.0-300 nmol/L in 5 min. The RSDs of the signal intensity and the migration time were less than 3.9 and 7.0% for a standard sample containing 100 nmol/L luminol and ABEI (n=5), respectively. The investigation implies that DPC is a promising sensitizer for CE-CL detection of a great variety of biomolecules and drugs in biological samples after derivatization using luminol derivatives. 相似文献
A simple and mild method for the determination of fatty acids (C1 – C10) based on a condensation reaction using 7-aminonaphthalene-1,3-disulfonic acid (ANDSA) as labeling reagent with capillary zone electrophoresis has been developed. The detection was performed with a diode array detector at 254 nm. A 58.5 cm × 50 μm i.d. (50 cm effective length) untreated fused-silica capillary was used. To optimize the separation conditions, the background electrolyte concentration, column temperature, voltage and other factors were evaluated. The optimal separation conditions were as follows: 30 mmol L−1 borate buffer (pH 9.5), 15 mmol L−1 β-CD, temperature at 20 °C, pressure 50 mbar and injection time 8 s. Under the established conditions, 10 fatty acid derivatives could be well-separated within 17 min. The linearity was in the range of 0.07–5.0 μmol L−1. Detection limits (at a signal-to-noise ratio of 3) were in the range of 0.027–0.042 μmol L−1. The fatty acids from the extracted Funaria Hedw. and Selaginella samples were determined with satisfactory results.
A novel method using liquid chromatography coupled to electrospray ionization mass spectrometry (LC-ESI-MS) has been optimized and established for the qualitative and quantitative analysis of ten active phenolic compounds originating from the pigeon pea leaves and a medicinal product thereof (Tongluo Shenggu capsules). In the present study, the chromatographic separation was achieved by means of a HiQ Sil C18V reversed-phase column with a mobile phase consisting of methanol and 0.1% formic acid aqueous solution. Low-energy collision-induced dissociation tandem mass spectrometry (CID-MS/MS) using the selected reaction monitoring (SRM) analysis was employed for the detection of ten analytes which included six flavonoids, two isoflavonoids and two stilbenes. All calibration curves showed excellent coefficients of determination (r(2) ≥ 0.9937) within the range of tested concentrations. The intra- and inter-day variations were below 5.36% in terms of relative standard deviation (RSD). The recoveries were 95.08-104.98% with RSDs of 2.06-4.26% for spiked samples of pigeon pea leaves. The method developed was a rapid, efficient and accurate LC-MS/MS method for the detection of phenolic compounds, which can be applied for quality control of pigeon pea leaves and related medicinal products. 相似文献
<正>A relatively high predetermined crystallization temperature(135℃) was chosen to grow well developed iPP spherulites,then the partial melting was carried out at a temperature of 165℃,where the preformed spherulites were seen to only decrease their size but not completely melted.The crystallization behavior of partially melted isotactic polypropylene (iPP) has been carefully examined by different scanning calorimetry(DSC) and polarized light microscopy(PLM).The experimental results show that at a special annealing temperature(165℃) the melting behavior of iPP includes two parts with different mechanism,one part is the melting of iPP spherulite outside,another is the partial lamellae perfection during longer annealing time in the unmelted spherulite.The conformational orders of the iPP melt decrease with the increase of the annealing temperature. 相似文献
The aim of this paper is to study the effect of low-level laser irradiation (LLLI) on proliferation of myoblasts in culture.
Myoblasts derived from rat skeletal muscle were irradiated by He-Ne laser with different doses. Compared with nonirradiated
control group, the number of myoblasts increased when the cells in normal culture conditions were exposed to the laser of
specific energy density. The amount of cells with proliferating cell nuclear antigen (PCNA) positive expression and the 5-bromo-2′-deoxyuridine
(BrdU) incorporation rate after laser irradiation were also higher than that of the control group, suggesting that LLLL at
certain doses can effectively enhance myoblasts growth activity in vitro. This study firstly demonstrated that stimulating
myoblasts to enter into proliferative stage from initial resting state was an important mechanism of regeneration and repair
of injured skeletal muscle promoted by LLLI in clinical treatment. 相似文献
We report a continuous-wave (CW) coherent green radiation at 532 nm by intracavity frequency doubling generation of 1064 nm
Nd:Gd0.18Y0.82VO4 laser. With incident pump power of 18.2 W, output power of 1.08 W at 532 nm has been obtained using a 5 mm-long KTP crystal.
The optical conversion efficiency was up to 5.9%. At the output power level of 1.08 W, the output stability is better than
5%. The beam quality M2 values were equal to 1.26 and 1.12 in X and Y directions, respectively. 相似文献
We report a diode-pumped Pr3+:YAlO3 laser emitting at 747 nm. A power of 232 mW at 747 nm has been achieved in continuous-wave operation with a diode emitting
2 W at 448 nm. Furthermore, intracavity second-harmonic generation in continuous-wave mode has also been demonstrated with
a power of 52 mW at 374 nm by using a LBO nonlinear crystal. The fluctuation of the violet output power was better than 2.3%.
The beam quality M2 value is 2.2. 相似文献