RESUMO
Organic-inorganic hybrid linear and nonlinear optical (NLO) materials have received increasingly wide spread attention in recent years. Herein, the first hybrid noncentrosymmetric (NCS) borophosphate, (C5H6N)2B2O(HPO4)2 (4PBP), is rationally designed and synthesized by a covalent-linkage strategy. 4-pyridyl-boronic acid (4 PB) is considered as a bifunctional unit, which may effectively improve the optical properties and stability of the resultant material. On the one hand, 4 PB units are covalently linked with PO3(OH) groups via strong B-O-P connections, which significantly enhances the thermal stability of 4PBP (decomposition at 321, vs lower 200 °C of most of hybrid materials). On the other hand, the planar π-conjugated C5H6N units and their uniform layered arrangements represent large structural anisotropy and hyperpolarizability, achieving the largest birefringence (0.156 @ 546 nm) in the reported borophosphates and a second-harmonic generation response (0.7 × KDP). 4PBP also exhibits a wide transparency range (0.27-1.50 µm). This work not only provides a promising birefringent material, but also offers a practical covalent-attachment strategy for the rational design of new high-performance optical materials.
RESUMO
OBJECTIVE: To evaluate the relationship between the metabolism of arsenic and the damage of exon 5 and 8 of p53 gene from workers in a arsenic mill, and with real-time PCR technique, to establish the method probing the gene-specific DNA damage in people. METHODS: By real-time PCR, the damages of exon 5 and 8 of p53 gene were probed in 37 workers exposed highly to, 16 manager and logistic employees exposed less to an arsenic mill in Yunnan province, and also 25 local people who did not contact with any white arsenic in near past time. At the same time, the urinary total and organic arsenic of workers were detected. The correlation between metabolism of arsenic and damage of p53 gene was evaluated. RESULTS: Total urinary arsenic concentrations were (1.18 +/- 0.76) mg/L and (0.32 +/- 0.28) mg/L for high and low exposed male workers, and 0.23 mg/L, (0.53 +/- 0. 30) mg/L for high and low exposed females. Organic urinary arsenic concentrations were (0.48 +/- 0.37) mg/L and (0.08 +/- 0.05) mg/L for high and low exposed males, and 0.11 mg/L, (0.30 +/- 0.24) mg/L for high and low exposed females. The total and organic urinary arsenic of high exposed group was higher than that of control male (P < 0.05), all in control group were lower than 0.02 mg/L for reference. The Ct relative value of exon 5 of p53 gene in high exposed group was higher than that in control male (P < 0.05), and the increased tendency of Ct relative value of exon 5 of p53 gene was found in workers with organic arsenic concentration going up (r(s) = 0.355, P = 0.011). The Ct relative value of exon 8 of p53 gene in low exposed group was higher than that in control male (P < 0.05), but the difference between high exposed and low exposed or reference's was not obvious (P > 0.05). CONCLUSION: The damages in exon 5 and 8 of p53 gene in workers exposed to arsenic may be induced. The metabolism of arsenic may be very important in the damage of exon 5. It is feasible for real-time PCR technique used to detect gene-specific DNA damage in people.