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Carboniferous adakites and Nb-enriched arc basaltic rocks association in the Alataw Mountains, north Xinjiang: interactions between slab melt and mantle peridotite and implications for crustal growth

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Chinese Science Bulletin 2003年第19期48卷 2108-2115页

作者： WANGQiang ZHAOZhenhua BAIZhenghua BAOZhiwei XIONGXiaolin MEIHoujun XUJifeng WANGYixian bioengineeringcollege FujianNormalUniversityFuzhou350007China GuangzhouInstituteofGeochemistry ChineseAcademyofSciencesGuangzhou510640China

Adakites and Nb-enriched arc basaltic rocks (NEABs) are identified to occur within the Carboniferous arc volcanic sequence in the Alataw Mountains, Xinjiang. The adakites, which consist of calc-alkaline dacites and rhyolites, are characterized by strong depletion of heavy rare earth elements (HREEs) (e.g., Yb) and Y, high Sr contents and Sr/Y ratios, either with no Eu anomalies or obvious positive Eu anomalies, apparent positive Sr anomalies, and depleted Nb and Ti. The Alataw adakites are very geochemically similar to the adakites that were presumably derived from partial melting of subducting oceanic crust. The rhyolitic adakite in the Alataw Mountains shows low MgO contents of 0.35% and Mg# values of about 17. However, the dacitic adakite shows high MgO contents of 2.67% to 3.32% and Mg# values of 53 to 58, suggesting that the adakite was possibly contaminated by mantle peridotite. On the other hand, the NEABs are characterized by Na-rich (Na2O/K2O > 2.0), high P2O5 and TiO2 contents, positive to weakly negative Nb anomalies, and non-negative Ti anomalies, suggesting that the NEABs were probably derived from partial melting of mantle peridotite that interacted with slab melt under high geothermal gradient. The Alataw adakites were probably derived from partial melting of oceanic crust on the southern margin of the Junggar plate that was subducted beneath the Bole block in the Carboniferous. The Alataw adakites-NE- ABs association implies that the partial melting of the subducting oceanic crust and the succedent interactions between the slab melt and peridotite in the mantle wedge possibly took place under the Bole arc in Carboniferous. On the southern margin of the Junggar plate, the Carboniferous subduction of oceanic crust (basin) was possibly extensive in the late Paleozoic era. In the Alataw area, high geothermal gradient possibly occurred in Carboniferous, and partial melting of subducting oceanic crust was a probable mechanism of Carboniferous regional crus

关键词：石炭纪铌-富集弧玄武岩质阿拉善山脉新疆平面熔化橄榄岩地壳生长地幔交代作用

New discovery of submerged forest remains in Shenhu bay, Fujian Province, and its environmental significance

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Chinese Science Bulletin 2003年第19期48卷 2116-2120页

作者： LIUJianqiu LINWenqun ZHAOXitao WANShaohong YUMingtong bioengineeringcollege FujianNormalUniversityFuzhou350007China InstituteofGeologyandGeophysics ChineseAcademyofSciencesBeijing100029China CollegeofGeographicalSciences FujianNormalUniversityFuzhou350007China

The authors have made a further investigation on the tidal-zone paleoforest remains found in the Shenhu bay, Fujian Province. By surveying (scale of 1︰500) andnumbering of the remains, 65 tree trunks were found. They are relatively concentrated in three different regions fromsouth to north. Their growing ages ranged from 45 a to 100 a. 22 ancient trunks?sections with low degree of carbonizationshow that the paleoforest was composed of Keteleeria Carr., Morus L. and Gleditsia L. 14C dating shows that thepaleoforest was living in 9 420—6760 aBP. Later it stoppeddeveloping and was buried by the alluvial aggradation caused by the sea level rise.

关键词：水下森林遗迹福建 Shenhu海湾环境变迁全新世

The composition and distribution of metal clusters in the MoFe protein from a nifZ deletion strain(DJ 194)of Azotobacter vinelandii

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Chinese Science Bulletin 2005年第13期50卷 1342-1347页

作者： ZHOUHuina ZHANGChunxi ZHAOYing BIANShaomin WANGHuangping HUANGJufu KeyLaboratoryofPhotosynthesisandEnvironmentalMolecularPhysiology InstituteofBotanyChineseAcademyofSciences.Beijing100093China//BioengineeringCollegeFujianNormalUniversityFuzhou350007China GraduateSchooloftheChineseAcademyofSciences.Beijing 100039 KeyLaboratoryofPhotosynthesisandEnvironmentalMolecularPhysiology InstituteofBotanyChineseAcademyofSciences.Beijing100093China//CollegeofBiologicalSciencesChinaAgriculturalUniversityBeijing100094China KeyLaboratoryofPhotosynthesisandEnvironmentalMolecularPhysiology InstituteofBotanyChineseAcademyofSciences.Beijing100093China

Through the anaerobic chromatography on the columns of DEAE 52, Q-Sepharose and Sephacryl S-200, a nitrogenase MoFe protein (?nifZ Av1) was obtained from a nifZ deleted mutant of Azotobacter vinelandii (stain DJ194). The results of Western blotting after anoxic native electro-phoresis and SDS-PAGE showed that ?nifZ Av1 was similar to wild type MoFe protein (OP Av1) at the electrophoretic mobility, molecular weight and subunit composition. Fur-thermore, ?nifZ Av1 was also similar to OP Av1 at the mo-lybdenum content, EPR signal (g≈4.3, 3.65 and 2.01), and the molar extinction coefficient (?ε) of circular dichroism (CD) at 660 nm region. All of these indicated that, besides having the same α2β2 composition as OP Av1, the ?nifZ Av1 also contained equal amount of reductive FeMoco in the spin state of S=3/2 to OP Av1. However, the iron content and sub-strate (C2H2, H+ and N2)-reduction activity of ?nifZ Av1 were 74% and 46%―50% of those of OP Av1, respectively. Fur-thermore, the ?ε at around 450 nm, which reflects P-cluster in Av1, was obviously lower than that of OP Av1. It suggested that the difference between ?nifZ Av1 and OP Av1 resulted from P-cluster rather than FeMoco, and from the half num-ber of P-cluster in ?nifZ Av1, but the composition or redox state of P-cluster in ?nifZ Av1 were not changed. Thus it could propose that ?nifZ Av1 is composed of two different αβ subunit pairs. One is a FeMoco- and P-cluster-containing pair, and the other is a P-cluster-deficient but FeMoco-con- taining pair. Since the deletion of nifZ gene leads to the defi-ciency of only one of two P-clusters in a α2β2 tetramer, the assembly of P-cluster may not simply depend on one gene product, and so a possible mechanism of NifZ is supposed here.

关键词：蛋白质固氮菌电泳运动分子重量

Integrins mediating bone signal transduction

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Journal of Chongqing University 2004年第1期3卷 55-60页

作者： HEChuanglong WANGYuanliang YANGLihua ZHANGJun KeyLaboratoryforBiomechanics＆TissueEngineeringUndertheMinistryofEducation ChongqingUniversityChongqing400030P.R.China bioengineeringcollege ChongqingUniversityChongqing400030P.R.China

Integrin-mediated adhesions play critical roles in diverse cell functions. Integrins offers a platform on which mechanical stimuli, cytoskeletal organization, biochemical signals can concentrate. Mechanical stimuli transmitted by integrins influence the cytoskeleton, in turn, the cytoskeleton influences cell adhesion via integrins, then cell adhesion results in a series of signal transduction cascades. In skeleton, integrins also have a key role for bone resoption by osteoclasts and reformation by osteoblasts. In present review, the proteins involved in integrin signal transduction and integrin signal transduction pathways were discussed, mainly on the basic mechanisms of integrin signaling and the roles of integrins in bone signal transduction, which may give insight into new therapeutic agents to all kinds of skeletal diseases and new strategies for bone tissue engineering.

关键词： integrin, signal transduction bone absoption bone formation