Carbonaceous shale exposures of the Late Cretaceous Mamu Formation along Ifon-Uzebba road in western arm(Benin Flank) of Anambra Basin, southwestern Nigeria, were analyzed for bulk organic geochemical, molecular biolo...Carbonaceous shale exposures of the Late Cretaceous Mamu Formation along Ifon-Uzebba road in western arm(Benin Flank) of Anambra Basin, southwestern Nigeria, were analyzed for bulk organic geochemical, molecular biological and poly-aromatic hydrocarbon(PAH) compositions to investigate the organic matter source, paleo-depositional condition, thermal maturity and petroleum potential of the unit. The bulk organic geochemistry was determined using Leco and Rock-Eval pyrolysis analyses while the biomarkers and PAH compositions were investigated using gas chromatography-mass spectrometer(GC-MS).The bulk organic geochemical parameters of the shale samples showed total organic carbon(TOC)(1.11-6.03 wt%), S2(0.49-11.73 mg HC/g Rock), HI(38-242 mg HC/g TOC) and Tmax(425-435 C) indicating good to excellent hydrocarbon source-rock. Typical HI-Tmax diagram revealed the shale samples mostly in the gas-prone Type Ⅲ kerogen region with few gas and oil-prone Type Ⅱ-Ⅲ kerogen. The investigated biomarkers(n-alkane, isoprenoid, terpane, hopane, sterane) and PAH(alkylnaphthalene, methylphenanthrene and dibenzothiophene) indicated that the carbonaceous shales contain mix contributions of terrestrial and marine organic matter inputs that were deposited in a deltaic to shallow marine settings and preserved under relatively anoxic to suboxic conditions.Thermal maturity parameters computed from Rock-Eval pyrolysis, biomarkers(hopane, sterane) and PAH(alkylnaphthalene, alkylphenanthrene, alkyldibenzothiophene) suggested that these carbonaceous shales in Anambra Basin have entered an early-mature stage for hydrocarbon generation. This is also supported by fluoranthene/pyrene(0.27-1.12), fluoranthene/(fluoranthene + pyrene)(0.21-0.53) ratios and calculated vitrinite reflectance values(0.49-0.63% Ro) indicative that these shales have mostly reached early oil window maturity, thereby having low hydrocarbon source potential.展开更多
Chinese-descent rhesus macaques have become more prevalent for HIV infection and vaccine investigation than Indian-origin macaques. Most of the currently available data and reagents such as major histocompatibility co...Chinese-descent rhesus macaques have become more prevalent for HIV infection and vaccine investigation than Indian-origin macaques. Most of the currently available data and reagents such as major histocompatibility complex （MHC） class I tetramers, however, were derived from Indian-origin macaques due to the dominant use of these animals in history. Although there are significant differences in the immunogenetic background between the two macaque populations, they share a few of common MHC class I alleles. We reported in this study the procedure for preparation of a soluble Mamu-B＊1703 （a MHC class I molecule of Chinese macaques） monomer and tetramer loaded with a dominant simian immunodeficiency virus （SIV） epitope IW9 （IRYPKTFGW） that was identified to be Mamu-B＊1701-restricted in Indian macaques. The DNA fragment encoding the Mamu-B＊1703 extracellular domain fused with a BirA substrate peptide （BSP） was amplified from a previously cloned cDNA and inserted into a prokaratic expression vector. In the presence of the antigenic peptide IW9 and light chain β2-microglobulin, the expressed heavy chain was refolded into a soluble monomer. After biotinylation, four monomers were polymerized as a tetramer by phycoerythrin-conjugated streptavidin. The tetramer, having been confirmed to have the right conformation, was a potential tool for investigation of antigen-specific CD8^＋ T-lymphocytes in SIV vaccine models of Chinese macaques. And our results also suggested that some antigenic peptides reported in Indian-origin macaques could be directly recruited as ligands for construction of Chinese macaque MHC tetramers.展开更多
TOURISM has developed rapidly in Beijing, and there are more and more sites to see, from the World Park to the China Ethnic Garden and a Miniature Replica of Old Beijing. These sites attract a large number of traveler...TOURISM has developed rapidly in Beijing, and there are more and more sites to see, from the World Park to the China Ethnic Garden and a Miniature Replica of Old Beijing. These sites attract a large number of travelers from both home and abroad. This is Mamu Age, from the Daliangshan Yi Nationality Autonomous Prefecture in Sichuan Province. She展开更多
文摘Carbonaceous shale exposures of the Late Cretaceous Mamu Formation along Ifon-Uzebba road in western arm(Benin Flank) of Anambra Basin, southwestern Nigeria, were analyzed for bulk organic geochemical, molecular biological and poly-aromatic hydrocarbon(PAH) compositions to investigate the organic matter source, paleo-depositional condition, thermal maturity and petroleum potential of the unit. The bulk organic geochemistry was determined using Leco and Rock-Eval pyrolysis analyses while the biomarkers and PAH compositions were investigated using gas chromatography-mass spectrometer(GC-MS).The bulk organic geochemical parameters of the shale samples showed total organic carbon(TOC)(1.11-6.03 wt%), S2(0.49-11.73 mg HC/g Rock), HI(38-242 mg HC/g TOC) and Tmax(425-435 C) indicating good to excellent hydrocarbon source-rock. Typical HI-Tmax diagram revealed the shale samples mostly in the gas-prone Type Ⅲ kerogen region with few gas and oil-prone Type Ⅱ-Ⅲ kerogen. The investigated biomarkers(n-alkane, isoprenoid, terpane, hopane, sterane) and PAH(alkylnaphthalene, methylphenanthrene and dibenzothiophene) indicated that the carbonaceous shales contain mix contributions of terrestrial and marine organic matter inputs that were deposited in a deltaic to shallow marine settings and preserved under relatively anoxic to suboxic conditions.Thermal maturity parameters computed from Rock-Eval pyrolysis, biomarkers(hopane, sterane) and PAH(alkylnaphthalene, alkylphenanthrene, alkyldibenzothiophene) suggested that these carbonaceous shales in Anambra Basin have entered an early-mature stage for hydrocarbon generation. This is also supported by fluoranthene/pyrene(0.27-1.12), fluoranthene/(fluoranthene + pyrene)(0.21-0.53) ratios and calculated vitrinite reflectance values(0.49-0.63% Ro) indicative that these shales have mostly reached early oil window maturity, thereby having low hydrocarbon source potential.
基金supported by Natural Science Fund of Guangdong Province (No.8451063201000340)the Talented Man Initiation Fund of Jinan University (No.51208004, No.51208017) to Dr. DY Ouyang +1 种基金grants from the National Natural Science Foundation of China (No.30572199, No.30230350 and No.30371651) to Prof. XH Hethe Biochemistry and Molecular Biology Key Discipline of Guangdong Province.
文摘Chinese-descent rhesus macaques have become more prevalent for HIV infection and vaccine investigation than Indian-origin macaques. Most of the currently available data and reagents such as major histocompatibility complex （MHC） class I tetramers, however, were derived from Indian-origin macaques due to the dominant use of these animals in history. Although there are significant differences in the immunogenetic background between the two macaque populations, they share a few of common MHC class I alleles. We reported in this study the procedure for preparation of a soluble Mamu-B＊1703 （a MHC class I molecule of Chinese macaques） monomer and tetramer loaded with a dominant simian immunodeficiency virus （SIV） epitope IW9 （IRYPKTFGW） that was identified to be Mamu-B＊1701-restricted in Indian macaques. The DNA fragment encoding the Mamu-B＊1703 extracellular domain fused with a BirA substrate peptide （BSP） was amplified from a previously cloned cDNA and inserted into a prokaratic expression vector. In the presence of the antigenic peptide IW9 and light chain β2-microglobulin, the expressed heavy chain was refolded into a soluble monomer. After biotinylation, four monomers were polymerized as a tetramer by phycoerythrin-conjugated streptavidin. The tetramer, having been confirmed to have the right conformation, was a potential tool for investigation of antigen-specific CD8^＋ T-lymphocytes in SIV vaccine models of Chinese macaques. And our results also suggested that some antigenic peptides reported in Indian-origin macaques could be directly recruited as ligands for construction of Chinese macaque MHC tetramers.
文摘TOURISM has developed rapidly in Beijing, and there are more and more sites to see, from the World Park to the China Ethnic Garden and a Miniature Replica of Old Beijing. These sites attract a large number of travelers from both home and abroad. This is Mamu Age, from the Daliangshan Yi Nationality Autonomous Prefecture in Sichuan Province. She
