Chemical, Mechanical, and Durability Properties of Concrete with Local Mineral Admixtures under Sulfate Environment in Northwest China

Over the vast Northwest China, arid desert contains high concentrations of sulfate, chloride, and other chemicals in the ground water, which poses serious challenges to infrastructure construction that routinely utilizes portland cement concrete. Rapid industrialization in the region has been generating huge amounts of mineral admixtures, such as fly ash and slags from energy and metallurgical industries. These industrial by-products would turn into waste materials if not utilized in time. The present study evaluated the suitability of utilizing local mineral admixtures in significant quantities for producing quality concrete mixtures that can withstand the harsh chemical environment without compromising the essential mechanical properties. Comprehensive chemical, mechanical, and durability tests were conducted in the laboratory to characterize the properties of the local cementitious mineral admixtures, cement mortar and portland cement concrete mixtures containing these admixtures. The results from this study indicated that the sulfate resistance of concrete was effectively improved by adding local class F fly ash and slag, or by applying sulfate resistance cement to the mixtures. It is noteworthy that concrete containing local mineral admixtures exhibited much lower permeability (in terms of chloride ion penetration) than ordinary portland cement concrete while retaining the same mechanical properties; whereas concrete mixtures made with sulfate resistance cement had significantly reduced strength and much increased chloride penetration comparing to the other mixtures. Hence, the use of local mineral admixtures in Northwest China in concrete mixtures would be beneficial to the performance of concrete, as well as to the protection of environment

Selective and Cleavable Extraction of Sialo-glycoproteins by Disulfide-Linked Amino-oxy-Functionalized Fe₃O₄ Magnetic Nanoparticles

The low abundance of sialo-glycoprotein hampered the separation, enrichment, and analysis of sialo-glycoproteins, which are critical for studying their functions. Here, we designed cleavable amino-oxy functionalized magnetic materials and employed to fast and selective isolate sialo-glycoproteins. This includes the ligation of disulfide-linked amino-oxy-functionalized magnetic nanoparticles with periodate-treated glycoproteins or cells, followed by magnetic separation. A reductive reagent could release the sialo-glycoproteins with small molecular fragments on the terminal of glycan chains, and the sialo-glycoproteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. On-bead digestion of the peptides were analyzed by tandem mass spectrometry. The results indicated that this method could selectively separate the majority of cell-surface sialo-glycoproteins

Selective and Cleavable Extraction of Sialo-glycoproteins by Disulfide-Linked Amino-oxy-Functionalized Fe₃O₄ Magnetic Nanoparticles

The low abundance of sialo-glycoprotein hampered the separation, enrichment, and analysis of sialo-glycoproteins, which are critical for studying their functions. Here, we designed cleavable amino-oxy functionalized magnetic materials and employed to fast and selective isolate sialo-glycoproteins. This includes the ligation of disulfide-linked amino-oxy-functionalized magnetic nanoparticles with periodate-treated glycoproteins or cells, followed by magnetic separation. A reductive reagent could release the sialo-glycoproteins with small molecular fragments on the terminal of glycan chains, and the sialo-glycoproteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. On-bead digestion of the peptides were analyzed by tandem mass spectrometry. The results indicated that this method could selectively separate the majority of cell-surface sialo-glycoproteins