Evaluation of Cretaceous Hinterland Weathering and Climate in the Sichuan Basin, SW China

Cretaceous is characterized by high atmospheric CO2 concentration and a resultantly high temperature. Thus, the Earth system, which operated during the greenhouse condition, can be deduced by the investigation of the paleoclimate during the Cretaceous. However, information of paleoclimate from continental inland-basins is scarce compared to that from continental margin marine-basins. In this research, the changes of weathering condition through the whole Cretaceous Period were reconstructed by analyzing the whole-rock chemical composition and clay mineral composition of mudstone samples collected in the Sichuan Basin, SW China. The reconstructed paleoweathering intensity positively correlates with paleotemperature estimate, indicating that Cenomanian-Turonian stages were climatic optimum in the Sichuan Basin as well. Furthermore, the result suggests a Cenomanian-Turonian extremely high amplitude humidity fluctuation.

Coprecipitation mechanisms of Zn by birnessite formation and its mineralogy under neutral pH conditions

Birnessite(δ-Mn(IV)O_(2))is a great manganese(Mn)adsorbent for dissolved divalent metals.In this study,we investigated the coprecipitation mechanism of δ-MnO_(2) in the presence of Zn(II)and an oxidizing agent(sodium hypochlorite)under two neutral pH values(6.0 and 7.5).Themineralogical characteristics and Zn–Mn mixed products were compared with simple surface complexation by adsorption modeling and structural analysis.Batch coprecipitation experiments at different Zn/Mn molar ratios showed a Langmuir-type isotherm at pH 6.0,which was similar to the result of adsorption experiments at pH 6.0 and 7.5.X-ray diffraction and X-ray absorption fine structure analysis revealed triple-corner-sharing innersphere complexation on the vacant sites was the dominant Zn sorption mechanism on δ-MnO_(2) under these experimental conditions.A coprecipitation experiment at pH 6.0 produced some hetaerolite(ZnMn(Ⅲ)_(2)O_(4))and manganite(γ-Mn(Ⅲ)OOH),but only at low Zn/Mn molar ratios(<1).These secondary precipitates disappeared because of crystal dissolution at higher Zn/Mn molar ratios because they were thermodynamically unstable.Woodruffite(ZnMn(IV)_(3)O_(7)•2H_(2)O)was produced in the coprecipitation experiment at pH 7.5 with a high Zn/Mn molar ratio of 5.This resulted in a Brunauer–Emmett–Teller(BET)-type sorption isotherm,in which formation was explained by transformation of the crystalline structure ofδ-MnO_(2) to a tunnel structure.Our experiments demonstrate that abiotic coprecipitation reactions can induce Zn–Mn compound formation on theδ-MnO_(2) surface,and that the pH is an important controlling factor for the crystalline structures and thermodynamic stabilities.

Removal of estrogens by electrochemical oxidation process

Treatments of estrogens such as Estrone （El）, Estradiol （E2） and Ethinylestradiol （EE2） were conducted using an electrolytic reactor equipped with multi-packed granular glassy carbon electrodes. Experimental results showed that El, E2 and EE2 were oxidized in the range of 0.45-0.85 V and were removed through electro-polymerization. Observed data from continuous experiments were in good agreement with calculated results by a mathematical model constructed based on mass transfer limitation. In continuous treatment of trace estrogens （1 μg/L）, 98% of El, E2 and EE2 were stably removed. At high loading rate （100 μg/L）, removal efficiency of E1 was kept around 74%-88% for 21 days, but removal efficiency reduced due to passivation of electrodes. However, removal efficiency was recovered after electrochemical regeneration of electrodes in presence of ozone. Electric energy consumption was observed in the range of 1-2 Wh/m3. From these results, we concluded that the present electrochemical process would be an alternative removal of estrogens.

Cell-Based Microfluidic Device Utilizing Cell Sheet Technology

The developmentof microelectromechanical systems hasresulted in the rapid development of polydimethylpolysiloxane(PDMS)microfluidic devices for drug screening models.Various cell functions,such as the response of endothelial cells to fluids,have beenelucdated using microuidic devices.Additionlly,organon-achip systems that includeorgans that are importantfor biologicalcirculation,such as the heart,liver,pancreas,kidneys,and brain,have been developed.These organs realize the biologicalcirculation system in a manner that cannot be reproduced by artificial organs;however,the flow channels between the organsare often artifically created by PDMS.In this study,we developeda microfluidic device consisting only of cels,by combiningcell sheet technology with microtitanium wires.Microwires were placed between stacked fibroblast cellsheets,and the celisheets adhered to each other,afer which the microwires were removed leaving a luminal structure with a size approximatelyequal to the arteriolar size.The lumen structure was constructed using wires with diameters of 50,100,150,and 200μm,which were approximations of the arteriole diameters.Furthermore using a perfusion device,we successfully perfused theluminal structure created inside the celsheets.The results revealed that a aulture solution can be supplied toa cellsheet witha very high cell density.The biofabrication technology proposed in this study can contribute to the development of organ-on-a-chip systems.