Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1...Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1 efficiently to less polar metabolites. Preparative scale transformation with both fungi Absidia coerulea (3.3538) and Aspergillus niger (3.1858) have resulted in the production of one same metabolite (MT1). Its structure was char-acterized as 6-O-b-D-glucopyranosyl-20(S)-protopanaxatriol (Ginsenoside Rh1) on the basis of its TOF-MS and 1H, 13C NMR spectral data. The biotransformation kinetic curves for Ginsenoside Rg1 and MT1 were reported for the first time, and the biotransformation pathway was proposed.展开更多
The failure modes of rock and soil under compression are complex phenomena that have not been explained in a mechanical perspective. However, large amounts of studies indicate that the failure modes of rock and soil s...The failure modes of rock and soil under compression are complex phenomena that have not been explained in a mechanical perspective. However, large amounts of studies indicate that the failure modes of rock and soil samples can be categorized into eight types. In this work, the inner tensile stress and the dissipation and conversion of energy of rock and soil under compression are analyzed, then the effective conversion coefficient of energy is deduced, thus the tensile failure criterion of rock and soil under compression is established. Combined with the shear strength criterion of Mohr–Coulomb, a tensile joint shear strength criterion for rock and soil under compression is built. Therefore, a mechanical criterion model concerning the failure modes of rock and soil under compression is established and verified by tests. This model easily explains the test results in the existing literature and many natural phenomena, such as collapse.展开更多
This paper presents the structural design and dynamic analysis of the magnetic field of the collector of machining wastes. From the viewpoint of energy the magnetic coupled force exerted on machining wastes by the no...This paper presents the structural design and dynamic analysis of the magnetic field of the collector of machining wastes. From the viewpoint of energy the magnetic coupled force exerted on machining wastes by the nonuniform magnetic field of a permanent magnet has been discussed. The difficult problem that machining wastes attracted by a permanent magnet above the iron base platform has been solved.展开更多
Objective: To elucidate the relation between human tissue factor pathwayinhibitor-2 (TFPI-2) expression and ovarian tumor migration and invasion. Methods: Human TFPI-2expression vector pBos-Cite-neo/TFPI-2 was transfe...Objective: To elucidate the relation between human tissue factor pathwayinhibitor-2 (TFPI-2) expression and ovarian tumor migration and invasion. Methods: Human TFPI-2expression vector pBos-Cite-neo/TFPI-2 was transfected into ovarian tumor cells line A2780- Afterthe transfected cells were selected by G418, transfected and nontransfected cells were screened forTFPI-2 mRNA and protein by reverse transcription-polymerase chain reaction and Western blotanalysis, respectively. The number of transfected or nontransfected cells passing through membraneof Boyden chamber was counted as the basis assessing tumor cells migratory and invasive behaviors.Results: Expression of mRNA and protein of TFPI-2 was detectable in transfected cells. In invasionassay, the number of TFPI-2-expressing cells to traverse a Matrigel-coated membrane was obviouslydecreased compared with that of nonexpressing cells (59.3±6.5 vs 109.7±5.5, P 【 0.01); While inmigration assay, no significant difference through a noncoated membrane was observed amongtransfected and nontransfected cells (114.7±8.6 vs 127.3±7.1, P 】 0.05). Conclusion: Expression ofTFPI-2 may strongly inhibit the invasive ability of ovarian tumor cells in vitro, but has no effecton the migratory ability which provides an experimental basis for genotherapy of human ovariantumor.展开更多
Based on comparative test of two transfer story models, in one of which the transfer beam and basement column is constructed of steel reinforced concrete, and the other is constructed of ordinary reinforced concrete, ...Based on comparative test of two transfer story models, in one of which the transfer beam and basement column is constructed of steel reinforced concrete, and the other is constructed of ordinary reinforced concrete, its force behavior, ductility and failure mechanism under vertical and horizontal loads are studied. The results show that loading bearing and seismic behavior of transfer story structure with steel reinforced concrete beam and basement column is good. The relative design suggestion is put forward.展开更多
The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx（x=10, 12） glass-forming alloyswerestudied by differential thermal analysis combining with ...The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx（x=10, 12） glass-forming alloyswerestudied by differential thermal analysis combining with solidification structure analysis. The results indicate that the undercooling degree of Nd9Fe85-xTi4C2Bx（x=10, 12） alloys significantly increaseswith the rise of melt overheating degree, and two overheating degree thresholds corresponding to the drastic increase of the mean undercooling degree are found for each of the alloys. The existence of two turning points of the mean undercooling degreescan be linked to the structure transitions inside the overheated melts, which result in the evident increase of volume fraction of amorphous phasein the solidified structures.展开更多
文摘Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1 efficiently to less polar metabolites. Preparative scale transformation with both fungi Absidia coerulea (3.3538) and Aspergillus niger (3.1858) have resulted in the production of one same metabolite (MT1). Its structure was char-acterized as 6-O-b-D-glucopyranosyl-20(S)-protopanaxatriol (Ginsenoside Rh1) on the basis of its TOF-MS and 1H, 13C NMR spectral data. The biotransformation kinetic curves for Ginsenoside Rg1 and MT1 were reported for the first time, and the biotransformation pathway was proposed.
基金Projects(41572277,41402239)supported by the National Natural Science Foundation of ChinaProject(2015A030313118)supported by the Natural Science Foundation of Guangdong Province,China+1 种基金Project(20120171110031)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(201607010023)supported by the Science and Technology Program of Guangzhou,China
文摘The failure modes of rock and soil under compression are complex phenomena that have not been explained in a mechanical perspective. However, large amounts of studies indicate that the failure modes of rock and soil samples can be categorized into eight types. In this work, the inner tensile stress and the dissipation and conversion of energy of rock and soil under compression are analyzed, then the effective conversion coefficient of energy is deduced, thus the tensile failure criterion of rock and soil under compression is established. Combined with the shear strength criterion of Mohr–Coulomb, a tensile joint shear strength criterion for rock and soil under compression is built. Therefore, a mechanical criterion model concerning the failure modes of rock and soil under compression is established and verified by tests. This model easily explains the test results in the existing literature and many natural phenomena, such as collapse.
文摘This paper presents the structural design and dynamic analysis of the magnetic field of the collector of machining wastes. From the viewpoint of energy the magnetic coupled force exerted on machining wastes by the nonuniform magnetic field of a permanent magnet has been discussed. The difficult problem that machining wastes attracted by a permanent magnet above the iron base platform has been solved.
文摘Objective: To elucidate the relation between human tissue factor pathwayinhibitor-2 (TFPI-2) expression and ovarian tumor migration and invasion. Methods: Human TFPI-2expression vector pBos-Cite-neo/TFPI-2 was transfected into ovarian tumor cells line A2780- Afterthe transfected cells were selected by G418, transfected and nontransfected cells were screened forTFPI-2 mRNA and protein by reverse transcription-polymerase chain reaction and Western blotanalysis, respectively. The number of transfected or nontransfected cells passing through membraneof Boyden chamber was counted as the basis assessing tumor cells migratory and invasive behaviors.Results: Expression of mRNA and protein of TFPI-2 was detectable in transfected cells. In invasionassay, the number of TFPI-2-expressing cells to traverse a Matrigel-coated membrane was obviouslydecreased compared with that of nonexpressing cells (59.3±6.5 vs 109.7±5.5, P 【 0.01); While inmigration assay, no significant difference through a noncoated membrane was observed amongtransfected and nontransfected cells (114.7±8.6 vs 127.3±7.1, P 】 0.05). Conclusion: Expression ofTFPI-2 may strongly inhibit the invasive ability of ovarian tumor cells in vitro, but has no effecton the migratory ability which provides an experimental basis for genotherapy of human ovariantumor.
文摘Based on comparative test of two transfer story models, in one of which the transfer beam and basement column is constructed of steel reinforced concrete, and the other is constructed of ordinary reinforced concrete, its force behavior, ductility and failure mechanism under vertical and horizontal loads are studied. The results show that loading bearing and seismic behavior of transfer story structure with steel reinforced concrete beam and basement column is good. The relative design suggestion is put forward.
基金Projects(51174121,51274125)supported by the National Natural Science Foundation of ChinaProject(2010R50016-30)supported by Zhejiang Province Science and Technology Innovation Team of Key Projects,ChinaProject supported by the K.C.Wong Magna Fund of Ningbo University,China
文摘The effectsof melt overheating degree on the undercooling degree and resultant solidification structures of Nd9Fe85-xTi4C2Bx（x=10, 12） glass-forming alloyswerestudied by differential thermal analysis combining with solidification structure analysis. The results indicate that the undercooling degree of Nd9Fe85-xTi4C2Bx（x=10, 12） alloys significantly increaseswith the rise of melt overheating degree, and two overheating degree thresholds corresponding to the drastic increase of the mean undercooling degree are found for each of the alloys. The existence of two turning points of the mean undercooling degreescan be linked to the structure transitions inside the overheated melts, which result in the evident increase of volume fraction of amorphous phasein the solidified structures.
