Cleroindicin B, C and E, three new natural products originally isolated from Clerodendrum indicum, have been synthesized (in racemic forms for Cleroindicin C and E) by a facile route, starting from 2-(p-methoxy-phenyl...Cleroindicin B, C and E, three new natural products originally isolated from Clerodendrum indicum, have been synthesized (in racemic forms for Cleroindicin C and E) by a facile route, starting from 2-(p-methoxy-phenyl) ethanol 1. The (() cleroindicin C (5) has been resovled by the enantioselective inclusion methodology.展开更多
X65 low carbon steel was exposed to Co-60 radiation source with 1.25 MeV gamma rays, and cumulatively absorbed gamma irradiation doses(1, 2, and 3 Mgy) were obtained after different exposure time(333, 667, and 100...X65 low carbon steel was exposed to Co-60 radiation source with 1.25 MeV gamma rays, and cumulatively absorbed gamma irradiation doses(1, 2, and 3 Mgy) were obtained after different exposure time(333, 667, and 1000 h). The effect of cumulative gamma irradiation on microstructure and corrosion behaviour of the carbon steel in unirradiated aerobic Beishan groundwater at 25℃ was investigated by using positron annihilation, scanning vibrating electrode, and electrochemical techniques. Cumulative gamma irradiation increases vacancy intensity and decreases open circuit potential(OCP) of carbon steel. They indicate that the irradiated carbon steel is activated. Measured current density distribution above the irradiated carbon steel shows that cumulative gamma irradiation accelerates localized corrosion after 0.5 h of immersion. In contrast, the analysis of electrochemical impedance spectroscopy of the irradiated carbon steel indicates that localized corrosion is transformed into general corrosion after 12 h of immersion, which is also accelerated by cumulative gamma irradiation.展开更多
The research question being studied in this paper is how do different types of bacteria as food (Pseudomonas fluorescens and Bacillus megaterium) affect the lifespan of Caenorhabditis elegans in dpy-11 mutant-type and...The research question being studied in this paper is how do different types of bacteria as food (Pseudomonas fluorescens and Bacillus megaterium) affect the lifespan of Caenorhabditis elegans in dpy-11 mutant-type and wild-type? P. fluorescens and B. megaterium will be the two pathogens that will be tested on two different types of C. elegans: mutant-type dpy-11 and wild-type. From the analysis of primary articles studying these pathogens, it can be concluded that P. fluorescens and B. megaterium are decent contenders for allowing C. elegans to grow and possibly extend the lifespan of it. P. fluorescens will allow the lifespan of the two types of nematodes to be longer. Additionally, the mu-tant-type dpy-11 of C. elegans will have a much longer lifespan, even double, compared to that of the wild-type. The results showed P. fluorescens had a longer lifespan than B. megaterium but not as long as C. elegans’ main food source, E. coli. C. elegans mutant dpy-11 had a longer lifespan than the wild-type. Furthermore, there were no C. elegans present in the B. megaterium wild-type plates.展开更多
Vitamins are natural materials essential for maintaining the normal physical function of the live cells. It has been reported that 13 vitamins are needed in our body, included vitamin A, B vitamins (thiamine, ribofla...Vitamins are natural materials essential for maintaining the normal physical function of the live cells. It has been reported that 13 vitamins are needed in our body, included vitamin A, B vitamins (thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid and cobalamin), vitamin C, vitamin D, vitamin E and vitamin K. Nowadays, the functions of vitamins have been extensively investigated. The objective of this paper is to summarize the new functions of vitamins, aiming to provide suggestions on the usage of various vitamins in clinical application.展开更多
三次有理B e zier曲线不能随着工程造型的需要而随时改变其次数,因此本文根据n次有理B e zier曲线和C-B样条曲线的一些性质,给出了C-B样条曲线与n次有理B e zier曲线的三种拼接条件,即G^0、G^1、G^2连续,由于n次有理B e zier曲线能够随...三次有理B e zier曲线不能随着工程造型的需要而随时改变其次数,因此本文根据n次有理B e zier曲线和C-B样条曲线的一些性质,给出了C-B样条曲线与n次有理B e zier曲线的三种拼接条件,即G^0、G^1、G^2连续,由于n次有理B e zier曲线能够随意的改变其次数,从而可以被应用于CAD/CAM中.展开更多
Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and 13CNMR),they were identified as 3,7,11,...Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and 13CNMR),they were identified as 3,7,11,12,15,23-hexaoxo-5α-lanosta-8-en-26-oic acid(Ⅰ),gano- deric acid B(Ⅱ),C(Ⅲ),D(Ⅳ)and ganodermanontriol(Ⅴ).Compound Ⅰ is a new natural product, named ganosporeric acid A.Compounds Ⅱ,Ⅲ,Ⅳ and Ⅴ are known compounds and were obtained for the first time from the spores of Ganoderma lucidum.Pharmacological experiments showed that ganosporeric acid A has an activity for lowering the levels GPT in mice with liver injury by CCl_4 and GaNI and exhibits heptoprotective effects.展开更多
摘要Cleroindicin B, C and E, three new natural products originally isolated from Clerodendrum indicum, have been synthesized (in racemic forms for Cleroindicin C and E) by a facile route, starting from 2-(p-methoxy-phenyl) ethanol 1. The (() cleroindicin C (5) has been resovled by the enantioselective inclusion methodology.
基金supported by Key Research Program of Frontier Sciences,Chinese Academy of Sciences[QYZDY-SSWJSC012]National Natural Science Foundation[No.51771211]+1 种基金the National Key Research and Development Program of China[2017YFB0702100,2016YFE0105200]Key Program of the Chinese Academy of Sciences[ZDRW-CN-2017-1]
摘要X65 low carbon steel was exposed to Co-60 radiation source with 1.25 MeV gamma rays, and cumulatively absorbed gamma irradiation doses(1, 2, and 3 Mgy) were obtained after different exposure time(333, 667, and 1000 h). The effect of cumulative gamma irradiation on microstructure and corrosion behaviour of the carbon steel in unirradiated aerobic Beishan groundwater at 25℃ was investigated by using positron annihilation, scanning vibrating electrode, and electrochemical techniques. Cumulative gamma irradiation increases vacancy intensity and decreases open circuit potential(OCP) of carbon steel. They indicate that the irradiated carbon steel is activated. Measured current density distribution above the irradiated carbon steel shows that cumulative gamma irradiation accelerates localized corrosion after 0.5 h of immersion. In contrast, the analysis of electrochemical impedance spectroscopy of the irradiated carbon steel indicates that localized corrosion is transformed into general corrosion after 12 h of immersion, which is also accelerated by cumulative gamma irradiation.
摘要The research question being studied in this paper is how do different types of bacteria as food (Pseudomonas fluorescens and Bacillus megaterium) affect the lifespan of Caenorhabditis elegans in dpy-11 mutant-type and wild-type? P. fluorescens and B. megaterium will be the two pathogens that will be tested on two different types of C. elegans: mutant-type dpy-11 and wild-type. From the analysis of primary articles studying these pathogens, it can be concluded that P. fluorescens and B. megaterium are decent contenders for allowing C. elegans to grow and possibly extend the lifespan of it. P. fluorescens will allow the lifespan of the two types of nematodes to be longer. Additionally, the mu-tant-type dpy-11 of C. elegans will have a much longer lifespan, even double, compared to that of the wild-type. The results showed P. fluorescens had a longer lifespan than B. megaterium but not as long as C. elegans’ main food source, E. coli. C. elegans mutant dpy-11 had a longer lifespan than the wild-type. Furthermore, there were no C. elegans present in the B. megaterium wild-type plates.
摘要Vitamins are natural materials essential for maintaining the normal physical function of the live cells. It has been reported that 13 vitamins are needed in our body, included vitamin A, B vitamins (thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid and cobalamin), vitamin C, vitamin D, vitamin E and vitamin K. Nowadays, the functions of vitamins have been extensively investigated. The objective of this paper is to summarize the new functions of vitamins, aiming to provide suggestions on the usage of various vitamins in clinical application.
摘要三次有理B e zier曲线不能随着工程造型的需要而随时改变其次数,因此本文根据n次有理B e zier曲线和C-B样条曲线的一些性质,给出了C-B样条曲线与n次有理B e zier曲线的三种拼接条件,即G^0、G^1、G^2连续,由于n次有理B e zier曲线能够随意的改变其次数,从而可以被应用于CAD/CAM中.
基金This project was supported by National Natural Science Foundation of China
摘要Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and 13CNMR),they were identified as 3,7,11,12,15,23-hexaoxo-5α-lanosta-8-en-26-oic acid(Ⅰ),gano- deric acid B(Ⅱ),C(Ⅲ),D(Ⅳ)and ganodermanontriol(Ⅴ).Compound Ⅰ is a new natural product, named ganosporeric acid A.Compounds Ⅱ,Ⅲ,Ⅳ and Ⅴ are known compounds and were obtained for the first time from the spores of Ganoderma lucidum.Pharmacological experiments showed that ganosporeric acid A has an activity for lowering the levels GPT in mice with liver injury by CCl_4 and GaNI and exhibits heptoprotective effects.