Quantitative detection and comparison of sulfate glycosaminoglycans content in extracellular matrix of in vitro cultured epiphyseal, articular and rib chondrocytes

Objective To establish a method for quantitative detection of the sulfate glycosaminoglycans ( GAG) content in extracellular matrix of in vitro cultured chondrocytes so as to evaluate the biological characteristics of epiphyseal, articular and rib chondrocytes. Methods Sulfate GAG content in extracellular matrix of three chondrocytes was measured by the modified dimethylmethylene blue (DMB) method. The changes of the toluidine blue (TB) stain of chondrocytes were observed by light microscope. Results Primary chondrocytes had the highest content of sulfate GAG in the extracellular matrix, ie, epiphyseal chondrocytes reached ( 70. 12 ± 7. 72 )μg/cm2, articular chondrocytes (92.00 ± 10.15) μg/cm2 and rib chondrocytes (80.61 ± 11. 40) μg/cm2, respectively. On the third pasage chondrocytes, epiphyceal chondrocytes decreased to (53.27 ± 9. 50 ) μg/cm2, articular chondrocytes to (63.88 ± 11.92) μg/cm2 and rib chondrocytes to (58.94 ±8.21) μg/cm2, respectively. The change of TB in every passage

The optimum conditions for methanol conversion to dimethyl ether over modified sulfated zirconia catalysts prepared by different methods

Sulfated zirconia(SZ)and two promoted 1% Mn/SZ catalysts which have been prepared via sol gel(Mn/SZ-S)and impregnation(Mn/SZ-I)methods were studied.The morphology of the catalysts was characterized by XRD,BET,NH3-TPD,ICP,SEM and FT-IR analysis.The conversion of methanol to dimethyl ether and hydrocarbons was carried out in the temperature range of 120−300℃.The Mn/SZ-S showed the highest activity due to the high surface area with suitable acidity.The optimum condition of Mn/SZ-S catalyst was investigated at 200℃ and LHSV of 0.02 h^−1 in a time range from 30 to 210 min.It was found that the total conversion decreased from 80.18% to 53.26% at 210 min.The reusability of this catalyst was studied at the optimum condition up till four cycles for 1 h.The characterization of the reused catalyst showed a significant change in the structure and surface acidity due to the blockage of the surface acid sited by carbonaceous materials.

Effect of Sulfate on an Iron Manganese Catalyst for Fischer-Tropsch Synthesis

The effect of sulfate on Fischer-Tropsch synthesis performance was investigated in a slurryphase continuously stirred tank reactor （CSTR） over a Fe-Mn catalyst. The physiochemical properties of the catalyst impregnated with different levels of sulfate were characterized by N2 physisorption, X-ray photoelectron spectroscopy （XPS）, H2 （or CO） temperature-programmed reduction （TPR）, Mossbauer spectroscopy, and CO2 temperature-programmed desorption （TPD）. The characterization results indicated that the impregnated sulfate slightly decreased the BET surface area and pore volume of the catalyst, suppressed the catalyst reduction and carburization in CO and syngas, and decreased the catalyst surface basicity. At the same time, the addition of small amounts of sulfate improved the activities of FischerTropsch synthesis （FTS） and water gas shift （WGS）, shifted the product to light hydrocarbons （C1-C11） and suppressed the formation of heavy products （C12＋）. Addition of SO4^2- to the catalyst improved the FTS activity at a sulfur loading of 0.05-0.80 g per 100 g Fe, and S-05 catalyst gave the highest CO conversion （62.3%）, and beyond this sulfur level the activity of the catalyst decreased.

Geophysical, Petrographic and Geochemical Survey on the Nazca Lines

This paper reports some results of geoscientific investigations of the shallow subsurface beneath the Nazca geoglyphs in the stone desert in southern Peru. A resistivity and georadar survey was accompanied by soil sampling at a test site in the Palpa district. The resulting images of the two geophysical methods indicate similar structures. Georadar enables a fast and continuous data acquisition but is restricted in its depth of penetration. Despite the dry surface conditions, the electrical method yielded good results in the desert area. The resulting resistivity images for both vertical and horizontal slices provide structural information that might be interpreted in terms of lithology and water content. A promising correlation between sulfate content and electrical resistivity at shallow depth was observed that might be helpful to provide insight into the migration of chemical constituents. The approach to combine geophysical, mineralogical and geochemical methods proves to be successful to extend the knowledge on the weathering processes in the desert soil.