Synthesis and Antioxidant Properties of Psoralen Derivatives.

Five psoralen derivatives were synthesized and the structures of them were characterized by 1 H-NMR, 13 C-NMR, and IR. The antioxidant properties of the compounds were tested by inhibiting the free radical-initiated DNA oxidation and scavenging the radical reaction. The results showed that the effective stoichiometric factors (n) of the compounds V and IV could reach 2.00 and 2.11 in the system of inhibiting the DNA oxidation reaction initiated by 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). In the inhibition of ⋅OH-oxidation of the DNA system, compounds I~V showed antioxidant properties. The thiobarbituric acid absorbance (TBARS) percentages of compounds IV and V were 76.19 % and 78.84 %. Compounds I~V could also inhibit Cu2+ /GSH-oxidation of DNA, and all compounds exhibited good antioxidant properties except compound II (94.00 %). All the five compounds were able to trap diammonium 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) salt radical (ABTS+ ⋅), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH⋅) and 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-p-tolylox radical (galvinoxyl⋅). The ability of compounds I~V to scavenge those free radicals can be measured by the k values. The k values ranged from 0.07 to 0.82 in scavenging ABTS+ ⋅, galvinoxyl, and DPPH radicals, respectively.

[A case-control study of environmental and genetic factors and prostate cancer in Guangdong].

OBJECTIVE: To explore the etiologic relationship of prostate cancer and environmental and genetic polymorphism in southern China METHODS: A hospital-based and 1:1 matched case-control study was conducted. A total of 142 matched pairs of subjects were investigated in this study. The blood samples were collected from 85 cases of prostate cancer and 82 controls of other diseases after informing consent. The CYP1A1, CYP17 and AR genes were analyzed by using the method of PCR, PCR-RFLP. The data were analyzed with conditional logistic regression model. RESULTS: An increased risk of prostate cancer development was observed with the early first spermatorrhea (age < 18) (OR = 2.90, 95% CI: 1.76 - 4.80), early first sexual intercourse (age < or = 24) (OR = 2.38, 95% CI: 1.14 - 4.96), frequent sexual intercourse before 35 year old (OR = 1.80, 95% CI: 1.19 - 2.70), family history of cancer (OR = 2.70, 95% CI: 1.31 - 5.58), more intake of pork (OR =2.27, 95% CI: 1.38 - 3.70). Factors in lowing the risks were the fruit intake and drinking of green tea by OR value at 0.25 (95% CI: 0.08 - 0.75) and 0.52 (95% CI: 0.28 -0.96) respectively. CYP17 A1/A2 and CYP17 A2/A2 genotypes were related with a high risk of prostate cancer and OR values of 1.78 (95% CI: 0.70 - 4.53) and 2.57 (95% CI: 0.91 - 7.25) respectively. Study also showed that there was an interaction between CYP17 polymorphisms and early first spermatorrhea and family cancer history related to the risk of prostate cancer with OR value at 13.35 (95% CI: 1.58 - 113.00) and 4.01 (95% CI: 1.22 - 13.17) respectively. CONCLUSION: Sexual intercourse, dietary intake and family cancer history should be related to prostate cancer occurrence. CYP17 polymorphism might be associated with a high risk of prostate cancer. It suggests that there are multiple environmental and genetic factors to the prostate cancer.

Adaptive terminal sliding mode control for hypersonic flight vehicles with strictly lower convex function based nonlinear disturbance observer.

In this paper, the altitude and velocity tracking control of a generic hypersonic flight vehicle (HFV) is considered. A novel adaptive terminal sliding mode controller (ATSMC) with strictly lower convex function based nonlinear disturbance observer (SDOB) is proposed for the longitudinal dynamics of HFV in presence of both parametric uncertainties and external disturbances. First, for the sake of enhancing the anti-interference capability, SDOB is presented to estimate and compensate the equivalent disturbances by introducing a strictly lower convex function. Next, the SDOB based ATSMC (SDOB-ATSMC) is proposed to guarantee the system outputs track the reference trajectory. Then, stability of the proposed control scheme is analyzed by the Lyapunov function method. Compared with other HFV control approaches, key novelties of SDOB-ATSMC are that a novel SDOB is proposed and drawn into the (virtual) control laws to compensate the disturbances and that several adaptive laws are used to deal with the differential explosion problem. Finally, it is illustrated by the simulation results that the new method exhibits an excellent robustness and a better disturbance rejection performance than the convention approach.

Characterization, catalyzed water oxidation and anticancer activities of a NIR BODIPY-Mn polymer.

To obtain near-IR absorbing biomaterials as fluorescence cellular imaging and anticancer agents for hypoxic cancer cell, a nano NIR fluorescence Mn(III/IV) polymer (PMnD) was spectroscopically characterized. The PMnD shows strong emission at 661nm when excited with 643nm. Furthermore, PMnD can catalyze water oxidation to generate dioxygen when irradiated by red LED light (10W). In particular, the PMnD can enter into HepG-2 cells and mitochondria. Both anticancer activity and the inhibition of the expression of HIF-1α for PMnD were concentration dependent. Our results demonstrate that PMnD can be developed as mitochondria targeted imaging agents and new inhibitors for HIF-1 in hypoxic cancer cells.