Porous Ti3SiC2with high purity was synthesized using TiH2,Si and C powders with mole ratio of Ti to Si to C being3:1.2:2by reactive synthesis method.The corrosion behaviors of porous Ti3SiC2in nitric acid and aqua reg...Porous Ti3SiC2with high purity was synthesized using TiH2,Si and C powders with mole ratio of Ti to Si to C being3:1.2:2by reactive synthesis method.The corrosion behaviors of porous Ti3SiC2in nitric acid and aqua regia were investigated byimmersing test.Scanning electron microscope(SEM),X-ray diffractometer(XRD),energy dispersive spectrometer(EDS)and X-rayphotoelectron spectroscopy(XPS)were used to analyze the morphology,compositions and element contents of the samples beforeand after corrosion to determine the corrosion product and corrosion mechanism.The mass loss values of porous Ti3SiC2are26.9and132.5μg/cm2,respectively after immersing in nitric acid and aqua regia for600h.The results indicate that Ti3SiC2transforms toTi5Si3which has better corrosion resistance in nitric acid and aqua regia with mass loss values of9.34and7.06μg/cm2under thesame immersing time,respectively.The dramatic dissolution of porous Ti3SiC2in the acids is due to its special microstructure.展开更多
One new triterpenoid, 3β-[(E)-caffeoyloxy]-D:C-friedooleana-7,9(11)-dien-29-oic acid(1) and nine known triterpenoids identified as cucurbitacin B(2), 23,24-dihydrocucurbitacin B(3), 23,24-dihydrocu-curbitacin D(4), c...One new triterpenoid, 3β-[(E)-caffeoyloxy]-D:C-friedooleana-7,9(11)-dien-29-oic acid(1) and nine known triterpenoids identified as cucurbitacin B(2), 23,24-dihydrocucurbitacin B(3), 23,24-dihydrocu-curbitacin D(4), cucurbitacin D(5), cucurbalsaminol A(6), 3-epi-isocucurbitacin D(7), curbitacin G(8), cucurbitacin J(9) and cucurbitacin I(10) were purified from Trichosanthes cucumeroides. Their structures were confirmed by spectroscopic data analysis and comparison with previous literature. All compounds were obtained from T. cucumeroides for the first time.展开更多
Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs h...Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs have anti-senescence activity for human cells remains.Human embryonic lung fibroblast (HFL-I)cells were cultured in media containing no MRJPs (A),MRJPs at 0.1mg/ml (B),0.2mg/ml (C),or 0.3mg/ml (D),or bovine serum albumin (BSA)at 0.2mg/ml (E).The mean population doubling levels of cells in media B,C,D,and E were increased by 12.4%,31.2%,24.0%,and 10.4%,respectively,compared with that in medium A.The cells in medium C also exhibited the highest relative proliferation activity,the lowest senescence,and the longest telomeres.Moreover, MRJPs up-regulated the expression of superoxide dismutase-1(SOD1)and down-regulated the expression of mammalian target of rapamycin (MTOR),catenin beta like-1(CTNNB1),and tumor protein p53(TP53).Raman spectra analysis showed that there were two unique bands related to DNA synthesis materials,amide carbonyl group vibrations and aromatic hydrogens.These results suggest that MRJPs possess anti-senescence activity for the HFL-I cell line,and provide new knowledge illustrating the molecular mechanism of MRJPs as anti-senescence factors.展开更多
基金Projects(51604305,51504296) supported by the National Natural Science Foundation of ChinaProject(2016M592445) supported by the China Postdoctoral Science FoundationProject(169715) supported by the Postdoctoral Science Foundation of Central South University,China
文摘Porous Ti3SiC2with high purity was synthesized using TiH2,Si and C powders with mole ratio of Ti to Si to C being3:1.2:2by reactive synthesis method.The corrosion behaviors of porous Ti3SiC2in nitric acid and aqua regia were investigated byimmersing test.Scanning electron microscope(SEM),X-ray diffractometer(XRD),energy dispersive spectrometer(EDS)and X-rayphotoelectron spectroscopy(XPS)were used to analyze the morphology,compositions and element contents of the samples beforeand after corrosion to determine the corrosion product and corrosion mechanism.The mass loss values of porous Ti3SiC2are26.9and132.5μg/cm2,respectively after immersing in nitric acid and aqua regia for600h.The results indicate that Ti3SiC2transforms toTi5Si3which has better corrosion resistance in nitric acid and aqua regia with mass loss values of9.34and7.06μg/cm2under thesame immersing time,respectively.The dramatic dissolution of porous Ti3SiC2in the acids is due to its special microstructure.
基金Hubei Provincial Outstanding Young and Middle-aged Science and Technology Innovation Team Project(Grant No.T201813)。
文摘One new triterpenoid, 3β-[(E)-caffeoyloxy]-D:C-friedooleana-7,9(11)-dien-29-oic acid(1) and nine known triterpenoids identified as cucurbitacin B(2), 23,24-dihydrocucurbitacin B(3), 23,24-dihydrocu-curbitacin D(4), cucurbitacin D(5), cucurbalsaminol A(6), 3-epi-isocucurbitacin D(7), curbitacin G(8), cucurbitacin J(9) and cucurbitacin I(10) were purified from Trichosanthes cucumeroides. Their structures were confirmed by spectroscopic data analysis and comparison with previous literature. All compounds were obtained from T. cucumeroides for the first time.
基金Project supported by the Science and Technology Project of Zhejiang Province(No.2017C32033)the National Natural Science Foundation of China(No.3127848)
文摘Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs have anti-senescence activity for human cells remains.Human embryonic lung fibroblast (HFL-I)cells were cultured in media containing no MRJPs (A),MRJPs at 0.1mg/ml (B),0.2mg/ml (C),or 0.3mg/ml (D),or bovine serum albumin (BSA)at 0.2mg/ml (E).The mean population doubling levels of cells in media B,C,D,and E were increased by 12.4%,31.2%,24.0%,and 10.4%,respectively,compared with that in medium A.The cells in medium C also exhibited the highest relative proliferation activity,the lowest senescence,and the longest telomeres.Moreover, MRJPs up-regulated the expression of superoxide dismutase-1(SOD1)and down-regulated the expression of mammalian target of rapamycin (MTOR),catenin beta like-1(CTNNB1),and tumor protein p53(TP53).Raman spectra analysis showed that there were two unique bands related to DNA synthesis materials,amide carbonyl group vibrations and aromatic hydrogens.These results suggest that MRJPs possess anti-senescence activity for the HFL-I cell line,and provide new knowledge illustrating the molecular mechanism of MRJPs as anti-senescence factors.
