Authors:Xiao-Ling Xing, Feng-Qi Zhao, Shun-Nian Ma, Si-Yu Xu, Li-Bai Xiao, Hong-Xu Gao, and Rong-Zu Hu
The thermal decomposition behavior of composite modified double-base propellant containing hexanitrohexaazaisowurtzitane (CL-20/CMDB propellant) was studied by microcalorimetry. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow curves. The effect of different proportion of CL-20 to the thermal decomposition behavior, kinetics, and thermal hazard was investigated at the same time. The critical temperature of thermal explosion (Tb), the self acceleration decomposition temperature (TSADT), and the adiabatic decomposition temperature rise (ΔTad) were calculated to evaluate the thermal hazard of the CL-20/CMDB propellant. It shows that the CMDB propellant with 38% CL-20 has relative lower values of E and lgA, and with 18% CL-20 has the highest potential hazard.
Authors:Kit-leong Cheong, Ding-tao Wu, De-jun Hu, Jing Zhao, Kai-yue Cao, Chun-feng Qiao, Bang-xing Han, and Shao-ping Li
Multiple species of ginseng are well-known Chinese medicinal herbs. The glycome of Panax species has various beneficial effects; however, studies related to their systematic profiling are very limited. Therefore, the systematic profiling of the glycome of Panax species was investigated in this study. The sugars from different locations and different species of Panax (Panax ginseng, Panax quinquefolium, and Panax notoginseng) were prepared by microwave-assisted extraction. Free mono- and oligo-saccharides were identified by high-performance thin-layer chromatography (HPTLC). Furthermore, polysaccharides were compared and characterized by using saccharide mapping based on HPTLC analysis. The results showed that the mono- and oligo-saccharide in Panax species were similar, including the glucan and pectin type of polysaccharides in different locations and different species of Panax, respectively. The data are helpful to better understand the glycome of different species of Panax and may contribute to rational usage of polysaccharides from Panax species.
Authors:Jian-Hua Yi, Feng-Qi Zhao, Ying-Hui Ren, Bo-Zhou Wang, Cheng Zhou, Xiao-Ning Ren, Si-Yu Xu, Hai-Xia Hao, and Rong-Zu Hu
The high-pressure thermal properties and their correlation with burning rates of the composite modified double base (CMDB) propellants containing 3,6-bis (1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz), a substitute of hexogen (RDX), were investigated using the high-pressure differential scanning calorimetry (PDSC). The results show that there is a main exothermal decomposition process with the heating of each propellant. High pressure can restrain the volatilization of NG, accelerate the main decomposition reaction, and make the reaction occur easily. High pressure can change the main decomposition reaction mechanism function and kinetics, and the control process obeys the rule of Avrami–Erofeev equation at high pressure and chemical reaction at normal pressure. However, the mechanism function can not be changed by the ballistic modifier. The correlation between PDSC characteristic values and burning rates was carried out and found that u and keep a good linear relation, ku keeps a similar changing trend with u, and it can be used to study the effect of the ballistic modifier or the other component on the burning rates.
Authors:Chuan-Min Qi, Yong He, Xiao Wang, Man Feng, Jing-Li Xu, Rui Ding, Hang Liu, Yu-Rong Chen, Fang Li, Zhao-Hui Zhu, Yong-Hong Dang, Shu-Ting Zhang, and Ying Xie
d-glucosamine at concentration of certain range could kill tumor cells without influencing normal cells. There are also some
reports on the antitumor activity of d-glucosamine and its derivatives in murine models. It was therefore postulated that d-glucosamine might have the potential to invade tumor cells. We designed and radiosynthesized a glucosamine derivative, N-(2-[18F]fluoro-4-nitrobenzoyl)glucosamine ([18F]FNBG([18F]7)). Evaluations in vitro and in vivo were performed on tumor bearing mice. Excitingly, the radiochemical purity of [18F]FNBG([18F]7) was 99%, and besides the best radiochemical yield was up to 35%. The best T/Bl (Tumor/Blood) and T/M (Tumor/Muscle) ratios
of [18F]FNBG([18F]7) were 4.40 and 4.84. Although [18F]FNBG([18F]7) deserved further studies, the results revealed it might become a potential PET imaging agent for detecting tumors.
Authors:Yong He, Rui Ding, Hang Liu, Xiao Wang, Jing-Li Xu, Man Feng, Yu-Rong Chen, Chuan-Min Qi, Cheng Peng, Zhao-Hui Zhu, Yong-Hong Dang, Ming Wang, and Yun-Chuan Ma
As degradation product of Antineoplaston A10 in vivo, phenylacetyl glutamine showed antitumor activities. According to literatures,
we designed and radiosynthesized a phenylacetyl glutamine derivative, which was achieved under a mild reaction condition.
Evaluations in vitro and in vivo were performed on tumor bearing mice. Excitingly, the radiochemical purity of (S)-2-((S)-2-(4-(3-fluoropropyl)benzamido)-3-phenylpropanamido)pentanedioic
acid ([18F]FBPPA) was 98%, and besides the best radiochemical yield was up to 46%. T/Bl (Tumor/Blood) and T/M (Tumor/Muscle) ratios
of [18F]FBPPA at 60 min post injection were 2.33 and 3.51. Meanwhile, it showed satisfied stability in vitro and in vivo, compared
with 2-[18F]fluorodeoxyglucose ([18F]FDG). Although [18F]FBPPA deserved further studies to make optimizations on its structure, the results revealed it might become a potential
PET imaging agent for detecting tumors.