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991.
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993.
高效蛋白质浓缩剂的制备及浓缩作用的研究 总被引:3,自引:0,他引:3
采用自由基水溶液聚合方法合成了超高分子量的丙烯酸(钠)聚合物。该聚合物具有高达几十倍至上千倍的吸水能力,通过适当控制聚合物的交联度使其成为具有一定孔径的网状物,可用于生物大分子,如:蛋白质溶液或其它生物提取液的浓缩。试验了用反透析法浓缩胰蛋白酶的方法,与直接加入浓缩法相比,能够更好地保持酶的活性。与传统的浓缩方法相比,用该方法浓缩蛋白质具有效率高,浓缩剂用量少的优点。 相似文献
994.
Laser induced fluorescence excitation spectroscopy has been used to determine the previously ambiguous assignments of A-state stretching frequencies of CF2 radical under supersonic free jet conditions. The measured frequencies are v’1=1012.1±0.5cm-1, v’3=1180.2±0.5cm-1, which is in good agreement with Cameron's[6] calculation result. Furthermore, some transitions attributed to the (1,n-2,0)←(0,0,0), n≦6 progressions are first reported, and new parameters are derived from the spectra obtained. 相似文献
995.
以对苯二酚为基本原料,通过改进的甲氧基化、氯甲基化、锍化3个反应合成,得到(2,5-二甲氧基对苯乙炔)单体双锍盐2,5-二甲氧基对苯二苄氯锍盐,且产率达84%,并对每步反应的合成条件及原因进行了解释,运用色谱/质谱联用仪和核磁共振仪对每步产物进行了表征 相似文献
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Yan Fan Tao Wang Yinwei Qiu Yinli Yang Qiubo Pan Jun Zheng Songwei Zeng Wei Liu Gang Lou Liang Chen 《Molecules (Basel, Switzerland)》2021,26(22)
Graphene p-n junctions have important applications in the fields of optical interconnection and low–power integrated circuits. Most current research is based on the lateral p-n junction prepared by chemical doping and other methods. Here, we report a new type of pure graphene oxide (pGO) vertical p-n junctions which do not dope any other elements but only controls the oxygen content of GO. The I–V curve of the pGO vertical p–n junction demonstrates a remarkable rectification effect. In addition, the pGO vertical p–n junction shows stability of its rectification characteristic over long-term storage for six months when sealed and stored in a PE bag. Moreover, the pGO vertical p–n junctions have obvious photoelectric response and various rectification effects with different thicknesses and an oxygen content of GO, humidity, and temperature. Hall effect test results show that rGO is an n–type semiconductor; theoretical calculations and research show that GO is generally a p–type semiconductor with a bandgap, thereby forming a p–n junction. Our work provides a method for preparing undoped GO vertical p–n junctions with advantages such as simplicity, convenience, and large–scale industrial preparation. Our work demonstrates great potential for application in electronics and highly sensitive sensors. 相似文献
999.
Huilan Tang Ningyi Qin Chang Rao Jiahui Zhu Haiqiang Wang Guang Hu 《Molecules (Basel, Switzerland)》2021,26(22)
Background: Danshen (DS), the dry root of Salvia miltiorrhiza Bge., has been used in traditional Chinese medicine (TCM) for many years to promote blood circulation and to inhibit thrombosis. However, the active ingredients responsible for the anti-thrombotic effect and the underlying mechanisms are yet to be fully elucidated. Methods: Molecular docking was used to predict the active ingredients in DS and their potential targets by calculating the scores of docking between DS ingredients and thrombosis-related proteins. Then, a chemical-induced zebrafish thrombosis model was applied to confirm their anti-thrombotic effects. Result: The molecular docking results indicated that compared to the control ligand, higher docking scores were observed for several compounds in DS, among which salvianolic acid B (SAB), lithospermic acid (LA), rosmarinic acid (MA), and luteolin-7-O-β-d-glucoside (LG) could attenuate zebrafish caudal vein thrombosis and recover the decrease in heart red blood cells (RBCs) in a dose-dependent manner. Conclusions: Our study showed that it is possible to screen the potential active components in natural products by combining the molecular docking method and zebrafish in vivo model. 相似文献
1000.
Nilupaier Tayier Ning-Yi Qin Li-Nan Zhao Yi Zeng Yu Wang Guang Hu Yuan-Qiang Wang 《Molecules (Basel, Switzerland)》2021,26(22)
Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin in the human body. Overproduction of melanin can lead to a variety of skin disorders. Calycosin is an isoflavone from Astragali Radix, which is a traditional Chinese medicine that exhibits several pharmacological activities including skin whitening. In our study, the inhibitory effect of calycosin on melanin production is confirmed in a zebrafish in vivo model by comparing with hydroquinone, kojic acid, and arbutin, known as tyrosinase inhibitors. Moreover, the inhibitory kinetics of calycosin on tyrosinase and their binding mechanisms are determined using molecular docking techniques, molecular dynamic simulations, and free energy analysis. The results indicate that calycosin has an obvious inhibitory effect on zebrafish pigmentation at the concentration of 7.5 μM, 15 μM, and 30 μM. The IC50 of calycosin is 30.35 μM, which is lower than hydroquinone (37.35 μM), kojic acid (6.51 × 103 μM), and arbutin (3.67 × 104 μM). Furthermore, all the results of molecular docking, molecular dynamics simulations, and free energy analysis suggest that calycosin can directly bind to the active site of tyrosinase with very good binding affinity. The study indicates that the combination of computer molecular modeling and zebrafish in vivo assay would be feasible in confirming the result of the in vitro test and illustrating the target-binding information. 相似文献