Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet

Laser action in methyl methacrylate （MMA） co-doped with sulforhodamine B and crystal violet dyes was investi- gated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd：YAG laser. Distributed feedback dye laser （DFDL） action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor-donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor-donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

Effect of Guizhi Fuling capsule and its extracts on human breast cancer cells proliferation

OBJECTIVE To evaluate the effect of Guizhi Fuling Capsule active pharmaceutical ingredient(API)and its fractions on human breast cancer cells proliferation by high-throughput screening assay.METHODS The crude fractions were obtained from the extraction and elution of the API of Guizhi Fuling Capsule,and 929 standard fractions were obtained by the optimal separation conditions.Sulforhodamine B(SRB)method was used to evaluate the effects of the Guizhi Fuling capsule API and929 kinds of fractions on the proliferation of human breast cancer cells MCF-7 and MDA-MB-231.RESULTS The Guizhi Fuling capsule API had a strong ability to inhibit the proliferation of MCF-7 cells at high concentration and the ability to inhibit MDA-MB-231 cells' proliferate at low concentration following 72 h treatment;some samples of 929 fractions(5μg·mL^(-1))was found to have a breast cancer cell growth inhibition rate above 50%,without toxicity on HUVECs proliferation.CONCLUSION The API of Guizhi Fuling capsule had significant cytotoxicity effects on these two human breast cancer cells,with significant concentration-and time-dependent manner.

New Green Synthesis and Antineoplastic Activity of Bis (3-Arylimidazolidinyl-1) Methanes

A new green synthesis and anti-tumor activity of the series of bis (3-arylimidazolidinyl-1) methanes 1 - 6 are described. The compounds were synthesized from the corresponding N-arylethylenediamine and trioxane as sources of formaldehyde and the reactions were performed in heterogeneous phase catalyzed by an acidic ion-exchange resin (Amberlyst 15). The compounds were tested with the Sulforhodamine B assay according to the protocol of the National Cancer Institute for several cell lines. The results were expressed as percentage inhibition of growth cell in comparison with the full growth of the cells without treatment. Cytotoxicity on normal cells using the Annexing-PI staining and flow cytometry has been evaluated. The parent compound, bis(3-phenylimidazolidinyl-1)methane 1 and the monohalogenated derivatives 4-chlorophenyl 3 and 3-bromophenyl 5 showed antineoplastic activity, 60%, 82% and 89% inhibition growth cell respectively on the human colon cell line (HCT116). The 4-tolyl derivative 6 presented inhibitory activity (73% inhibition of growth cell) on human lung adenocarcinoma cell line (A549) and 62% on human mammary cell line MCF-7.

Biological Activities and Crystal Structure of the Natural Anti-cancer Drug: Cucurbitacin Ⅱa

We isolated cucurbitacinⅡa from the rhizomes of Hemsleya pengxianensis,and tested the cytotoxicity of cucurbitacinⅡa against various cancer cell lines by the sulforhodamine B assay(SRB).At the same time,we preliminarily found that cucurbitacinⅡa has a certain inhibitory activity on kinase CDK1/cyclin B,and shows potent inhibitory activities against many cancer cell lines.The cucurbitacinⅡa was structurally characterized by specific optical rotation measurement,high-resolution mass spectroscopy and NMR spectroscopic analysis.In addition,the molecular structure of cucurbitacinⅡa was further determined by X-ray single-crystal crystallography.