Authors:Y. Cheng, H. F. Wang, H. F. Sun, H. L. Li, Y. F. Liu, S. X. Peng, K. X. Liu, and Z. Y. Guo
Accelerator mass spectrometry (AMS) is an ultra-sensitive method to monitor and trace the environmental exposure levels of 14C-labeled molecules in vivo. Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Using 14C-labeled nicotine and AMS, we have investigated the inhibitory effect of curcumin, garlic squeeze, grapeseed extract, tea polyphenols, vitamin C and vitamin E, respectively, on nicotine-hemoglobin (Hb) adduction in vivo. The results demonstrated that these dietary constituents induced remarkable decrease of nicotine-Hb adducts. The inhibitory fact may afford an important clue of the chemoprevention of the potential nicotine-induced carcinogenesis.
Authors:Li-Fang Song, Cheng-Li Jiao, Chun-Hong Jiang, Jian Zhang, Li-Xian Sun, Fen Xu, Qing-Zhu Jiao, Yong-Heng Xing, F. L. Huang, Yong Du, Zhong Cao, Fen Li, and Jijun Zhao
One-three-dimensional metal-organic frameworks Mg1.5(C12H6O4)1.5(C3H7NO)2 (MgNDC) has been synthesized solvothermally and characterized by single crystal XRD, powder XRD, FT-IR spectra. The low-temperature molar heat capacities of MgNDC were measured by temperature modulated differential scanning calorimetry (TMDSC) over the temperature range from 205 to 470 K for the first time. No phase transition or thermal anomaly was observed in the experimental temperature range. The thermodynamic parameters of MgNDC such as entropy and enthalpy relative to reference temperature of 298.15 K were derived based on the above molar heat capacities data. Moreover, the thermal stability and decomposition of MgNDC was further investigated through thermogravimetry (TG)–mass spectrometer (MS). Three stages of mass loss were observed in the TG curve. TG–MS curve indicated that the oxidative degradation products of MgNDC are mainly H2O, CO2, NO, and NO2.
Authors:M. Wang, Y. Sawada, K. Saito, S. Horie, T. Uchida, M. Ohtsuka, S. Seki, S. Kobayashi, T. Arii, A. Kishi, T. Takahashi, Y. Nishimoto, T. Wakimoto, K. Monzen, I. Kashima, T. Nishikiori, L. Sun, and R. Ozao
The thermal change of the tris(8-hydroxyquinolinato)aluminum (Alq3) is currently investigated by XRD-DSC and TG. The phase transition of Alq3 from α-phase to γ-phase takes place at 643–669 K. A very sharp peak with the peak temperature at approx. 709 K is ascribed
to the melting of the Alq3. The decomposition of the Alq3 was observed accompanied with the melting and evaporation at >703K. The effect of the atmospheres on the mass loss procedure
was studied by TG. It was found that thermal process of Alq3 was strongly influenced by the partial pressure of water vapor in the atmosphere instead of oxygen.