Xi Cao,Miao Qiao,Yayu Pan,Qingbin Bao,Guiquan Zhang,Yikun Xian
The fatty acid (FA) composition of giant panda colostrum and the variation during lactation were determined. Of the 35 FAs detected in giant panda milk fat , the most abundant were oleic acid , palmitic acid and linoleic acid . There were 14 very long-chain and 5 short- and medium-chain FAs detected. The ratio of n-6 to n-3 FAs was 3.60–7.21. Hierarchical clustering analysis demonstrated there was an unusually slow transition from colostrum to mature milk, probably an adaptive strategy. The oleic acid/linoleic acid ratio was higher in colostrum than mature milk, which may benefit digestion. Most saturated FAs were more abundant in mature milk than colostrum. Arachidonic acid accounted for 48.49% of very long-chain polyunsaturated FAs in colostrum, which was 3.34 fold that in mature milk, and for docosahexaenoic acid , 2.75 fold. During the lactation, Spearman correlations within unsaturated and saturated FAs were generally positive; correlations between them were generally negative.
It is highly anticipated to explore low-priced raw materials for preparing nitrocellulose (NC). The use of low-priced raw materials reduces environmental pollution while utilizing waste. In this paper, it is fascinating to prepare NC for propellants based on giant panda feces. The synthesis of NC based on giant panda feces and bitter bamboo stems as raw materials were labeled as P-NC and B-NC, respectively. Compared with cotton-based NC (NC12.5%), P-NC has certain advantages in decomposition heat, burning flame and speed, and mechanical properties. However, this advantage is very slight. The gastrointestinal digestion of giant pandas shortens the time for extracting α-cellulose. P-NC and B-NC are very similar in structure and properties, except that P-NC maintains a higher degree of crystallinity. The results show that P-NC can replace cotton-based NC in terms of performance for propellants. It should be emphasized that this paper is based on the use of animal excrement, which not only protects the environment and saves resources, but also reduces the workload of the staff at the giant panda conservation base. In addition, this paper also provides us with a new idea about waste utilization.
Yi Wang,Chuanting Qin,Xiaoxue Wang,Ting Wang,Jian Dong,Yuan Lu
The sense of smell in animals enables them to detect and discriminate among many volatile odor molecules in complex environments. This task is accomplished by the family of G-proteins (olfactory receptor proteins, odorant-binding proteins, and chemosensory proteins). Here, we mechanistically elucidate how odors bind to odorant-binding proteins (OBPs) by studying the binding properties of 50 odorant ligands to six OBPs. We confirmed that OBP7 from Ailuropoda melanoleuca and OBP9 from Anopheles gambiae have binding affinities for 16 odors, and further analyzed the structures and protein-ligand interactions by homology modeling and molecular docking. This study found that OBP7 had an affinity for nonanol and camphor, and the docking results indicated that Glu120 was a residue that played a key role in the binding process of OBP7 to odorant ligands. We also explored the binding properties between OBP9 and ligands as well as the binding mechanism, and found that OBP9 bound well to some odorant molecules with repellent efficacy, such as nonanol, camphor, and citral. These findings not only contributed to our understanding of how OBPs were sensitively bound to odorant ligands but also promoted them as suitable targets for applied research in various industrial fields such as pesticides, cosmetics, and pharmaceuticals.
危险品化学品经营许可证（带存储）