China
Africa
Explore chapters and articles related to this topic
Boron, Manganese, Molybdenum, Nickel, Silicon and Vanadium
Published in Judy A. Driskell, Ira Wolinsky, Sports Nutrition, 2005
Because the studies of both Schwarz and Carlisle were clouded by the use of high, possibly pharmacological, amounts of fairly soluble silicon for supplemental controls, the effects of silicon deprivation in rats were reexamined by Seaborn and Nielsen.177–179 In these studies, supplemented controls were fed a diet containing only 4.5–35 mg Si/kg as sodium metasilicate and compared with rats fed diets containing ≤ 2 mg Si/kg. These studies confirmed that silicon deprivation affects bone, hexosamine and collagen metabolism. Silicon deprivation decreased femur acid and alkaline phosphatase, and humerus hydroxyproline and plasma ornithine aminotransferase (a key enzyme in collagen synthesis). A recent study180 found that silicon deprivation decreased plasma osteopontin concentration, increased plasma sialic acid concentration and increased urinary helical peptide (bone collagen breakdown product) excretion. Also, the response of bone metabolism indicators to ovariectomy in young growing rats was generally lower in silicon-deprived than silicon-supplemented rats. It was concluded that the findings support the hypothesis that silicon has a biochemical function that affects bone growth processes before bone crystal formation, and this occurs by affecting bone collagen turnover and sialic acid-containing extracellular matrix proteins such as osteopontin.
Effect of micropore/microsphere topography and a silicon-incorporating modified titanium plate surface on the adhesion and osteogenic differentiation of BMSCs
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Wuchao Zhou, Tiesheng Wang, Yanzi Gan, Jian Yang, Hongshui Zhu, Anxun Wang, Yujiang Wang, Weihong Xi
The commercially obtained pure titanium material was cut into 10 mm × 10 mm × 1 mm plates. The titanium plates were polished sequentially with 400–1200 grit SiC sandpaper. The titanium plates were cleaned sequentially with acetone, ethanol and deionised water in an ultrasonic pot for 10 min and then dried at room temperature. The electrolyte was prepared with 0.02 M sodium dihydrogen phosphate pentahydrate (Na2HPO4·5H2O) and 0.1 M sodium metasilicate nonahydrate (Na2SiO3·9H2O). A model WHD-20 MAO power supply was used (Harbin University of Technology Sino-Russian Science and Technology Co., Ltd., China). The frequency and time were set to 50 Hz and 10 min, respectively. The voltage was set to 320 V, 350 V and 380 V for the MAO-320, MAO-350 and MAO-380 groups, respectively. The Ti group was the control group.
Effects of phosphate and silicate on stiffness and viscoelasticity of mature biofilms developed with simulated drinking water
Published in Biofouling, 2023
Conghui Huang, Gemma G. Clark, Farzana R. Zaki, Jungeun Won, Runsen Ning, Stephen A. Boppart, Ahmed E. Elbanna, Thanh H. Nguyen
Four types of biofilms were grown on PVC coupons (12.7 mm in diameter, Biosurface Inc.) in four CDC reactors fed by groundwater with or without nutrient or non-nutrient additives. The influent groundwater, a local drinking water supply, was pumped from a well located in Urbana-Champaign, IL. This groundwater was filtered by a greensand filter, similar to the treatment method used at the local drinking water treatment facility, to remove precipitates from the oxidation of iron and manganese. Silicate, phosphate, and phosphate blends (6:4 molar ratio of disodium phosphate and sodium hexametaphosphate) were selected to simulate common corrosion inhibitor levels applied in many drinking water plants (S. Mcneill and Edwards 2002). Groundwater (10 L) was mixed with disodium phosphate and sodium hexametaphosphate (2.4 mg L−1 as PO4) or sodium metasilicate (20 mg L−1 as SiO2) and served as influent to phosphate blends and silicate reactors, respectively. Disodium phosphate was mixed with 15 L of groundwater to reach a final concentration of 2 mg L−1 as PO4. The modified groundwater was prepared every two to three days. During biofilm formation, its structure and mechanical properties can change. For example, a soft top layer with increased thickness and biomass was reported in mature biofilms even though an increase in cell numbers was not observed (Martiny et al. 2003; Abe et al. 2011). The structural changes in three-year-old multispecies biofilms and succession events may not be predicted by biofilm formation models (Martiny et al. 2003; Sauer et al. 2022). The changes in mature biofilms can play an important role in the mechanical removal of biofilms in premise plumbing, which can be undisturbed for years. For example, a sanitary survey is required by the United States Environmental Protection Agency every three years in community water systems (USEPA 2008). Hence the biofilms used in the study were allowed to develop for three years. Shear condition (Re = ∼3510) in the CDC reactors was maintained by a stir bar during biofilm growth. The reactors were kept at around 25 °C and wrapped in foil.