AIM: To investigate the influence of peroxisome proliferator activated receptor γ (PPARγ) ligand, 15-deoxy-△12, 14-prostaglandin J2 (15dPGJ2) on the proliferation and apoptosis of MCG-803 human gastric cancer cell ...AIM: To investigate the influence of peroxisome proliferator activated receptor γ (PPARγ) ligand, 15-deoxy-△12, 14-prostaglandin J2 (15dPGJ2) on the proliferation and apoptosis of MCG-803 human gastric cancer cell lines.METHODS: Cell proliferation was measured by 3H-TdR assay. Apoptosis was determined by ELISA and TUNEL staining. Protein and mRNA level of bcl-2 family and COXs were measured by Western blotting and Northern blotting respectively. PGE2 production was examined by RIA.RESULTS: 15dPGJ2 inhibited cell growth and induced apoptosis of MlCG-803 cells. The COX-2 and bcl-2/bax ratios were decreased following 15dPGJ2 treatment. The PGE2production in supernatants was also decreased. These changes were in a dose-dependent manner.CONCLUSION: 15dPGJ2 may be a useful therapeutic agent for the treatment of gastric cancer.展开更多
The X56 steel samples was corroded in the medium of salt water solution at the conditions of CO2 partial pressure POM 0.5 to 2.0 MPa, temperature 80 °C and flow rate 1.4m/s. Corrosion weigh loss, composition and ...The X56 steel samples was corroded in the medium of salt water solution at the conditions of CO2 partial pressure POM 0.5 to 2.0 MPa, temperature 80 °C and flow rate 1.4m/s. Corrosion weigh loss, composition and structure, morphology and phase of corrosion films of the samples were investigate by SEM, EDS, XRD and XPS. The results indicated that the corrosion degree was accelerated with increasing POM ? The intense localised corrosion occurred on the surface of samples. The corrosion films mainly comprised of FeCO3 and complex phase products (Fe, Ca....)COj. There exists serious pitting on the metal substrates under the corrosion film. The theoretic and experimental analyses indicate this is caused by existed micropores or micro holes in films, which have the function of mass transportation.展开更多
Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au...Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C60Py molecules on Au (111) only exhibited randoml aggregation of C60Py even the films were annealed at 50 and 105℃. By co-assembling with benzyl mercaptan (BM), the C60Py- BM films showed highly dense aggregation, but C60Py assemblies still had disordered structure. After the co-assembled C60Py-BM films were annealed at 50℃, BM molecules were partially desorbed, but the assembly of C60Py remained without obvious change. After the co-assembled C60Py-BM films were further annealed at 105℃, the C60Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C60Py monolayer.展开更多
Chinese Forest Ecosystem Research Network, established in late 1950s and directly constructedand administered by the Science and Technology Department of State Forestry Administration of China,is a large ecology resea...Chinese Forest Ecosystem Research Network, established in late 1950s and directly constructedand administered by the Science and Technology Department of State Forestry Administration of China,is a large ecology research network focuses on long-term ecosystem fixed-observation. It embodies 15 sitesthat represent diverse ecosystems and research priorities, including 6 state-level sites. CFERN Officecoordinates communications, network publications, and research-planning activities. CFERN uses theadvanced ground and spatial observation technologies such as RS, GPS, GIS to study the structure,functional laws and feedback mechanism of Chinese forest ecosystem, as well as its effects on Chinassocial and economic development. The main tasks carried out by CFERN are: (1) construction of thedatabase on the structure and functions of Chinese forest ecosystem and its ecological environmentalfactors; (2) the database construction of forest resources, ecological environment, water resources andrelated social economy in both regional and national scales; (3) the establishment of an evaluation systemof forest ecological effects in Chinas main drainage areas; (4) the establishment of a forest environmentmonitoring network and a dynamic prediction and alarm system.展开更多
基金Science Fund of Guangdong Province,No.015012Science Fund of Guangzhou,2001-Z-01-2the State 973 Projects,2002ccc0400
文摘AIM: To investigate the influence of peroxisome proliferator activated receptor γ (PPARγ) ligand, 15-deoxy-△12, 14-prostaglandin J2 (15dPGJ2) on the proliferation and apoptosis of MCG-803 human gastric cancer cell lines.METHODS: Cell proliferation was measured by 3H-TdR assay. Apoptosis was determined by ELISA and TUNEL staining. Protein and mRNA level of bcl-2 family and COXs were measured by Western blotting and Northern blotting respectively. PGE2 production was examined by RIA.RESULTS: 15dPGJ2 inhibited cell growth and induced apoptosis of MlCG-803 cells. The COX-2 and bcl-2/bax ratios were decreased following 15dPGJ2 treatment. The PGE2production in supernatants was also decreased. These changes were in a dose-dependent manner.CONCLUSION: 15dPGJ2 may be a useful therapeutic agent for the treatment of gastric cancer.
文摘The X56 steel samples was corroded in the medium of salt water solution at the conditions of CO2 partial pressure POM 0.5 to 2.0 MPa, temperature 80 °C and flow rate 1.4m/s. Corrosion weigh loss, composition and structure, morphology and phase of corrosion films of the samples were investigate by SEM, EDS, XRD and XPS. The results indicated that the corrosion degree was accelerated with increasing POM ? The intense localised corrosion occurred on the surface of samples. The corrosion films mainly comprised of FeCO3 and complex phase products (Fe, Ca....)COj. There exists serious pitting on the metal substrates under the corrosion film. The theoretic and experimental analyses indicate this is caused by existed micropores or micro holes in films, which have the function of mass transportation.
基金supported by the National Project for the Development of Key Fundamental Science in China(G2001CB3095)the National Natural Science Foundation of China(Grant Nos.50121202,50132030&10374083).
文摘Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C60Py molecules on Au (111) only exhibited randoml aggregation of C60Py even the films were annealed at 50 and 105℃. By co-assembling with benzyl mercaptan (BM), the C60Py- BM films showed highly dense aggregation, but C60Py assemblies still had disordered structure. After the co-assembled C60Py-BM films were annealed at 50℃, BM molecules were partially desorbed, but the assembly of C60Py remained without obvious change. After the co-assembled C60Py-BM films were further annealed at 105℃, the C60Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C60Py monolayer.
文摘Chinese Forest Ecosystem Research Network, established in late 1950s and directly constructedand administered by the Science and Technology Department of State Forestry Administration of China,is a large ecology research network focuses on long-term ecosystem fixed-observation. It embodies 15 sitesthat represent diverse ecosystems and research priorities, including 6 state-level sites. CFERN Officecoordinates communications, network publications, and research-planning activities. CFERN uses theadvanced ground and spatial observation technologies such as RS, GPS, GIS to study the structure,functional laws and feedback mechanism of Chinese forest ecosystem, as well as its effects on Chinassocial and economic development. The main tasks carried out by CFERN are: (1) construction of thedatabase on the structure and functions of Chinese forest ecosystem and its ecological environmentalfactors; (2) the database construction of forest resources, ecological environment, water resources andrelated social economy in both regional and national scales; (3) the establishment of an evaluation systemof forest ecological effects in Chinas main drainage areas; (4) the establishment of a forest environmentmonitoring network and a dynamic prediction and alarm system.
