BACKGROUND AND AIMS Previous studies have shown that silica in grass leaves defends them against small herbivores, which avoid high-silica grasses and digest them less efficiently. This study tested the idea that silica can reduce digestibility by preventing the mechanical breakdown of chlorenchyma cells. METHODS Both the percentage of total chlorophyll liberated from high- and low-silica gra...

Silica nanoparticles have been functionalized by click chemistry and atom transfer radical polymerization (ATRP) simultaneously. First, the silanized silica nanoparticles were modified with bromine end group, and then the azide group was grafted onto the surface via covalent coupling. 3-Bromopropyl propiolate was synthesized, and then the synthesized materials were used to react with azide-modi...

G roundwaters in areas such as Texas, New Mexico, Arizona, California, parts of southern Europe, the Pacific Rim, and Latin America contain high silica concentrations (50 to 100 ppm, as colloidal silica [SiO 2 ]). These levels arise from dissolution of various silicate-containing minerals into the groundwater. Silica precipitation and deposition occur mostly in evaporative cooling systems, wher...

Polyamide 6/silica nanocomposites were synthesized by in situ ring-opening anionic polymerization of ε-caprolactam in the presence of sodium caprolactamate as a catalyst and caprolactam-functionalized silica as an initiator. The initiator precursor, isocyanate-functionalized silica, was prepared by directly reacting commercial silica with excess toluene 2,4-diisocyanate. This polymerization was...

metal nanoshells consists of a dielectric core surrounded by a thin noble metal shell, possess unique optical properties that render nanoshells attractive for use in different technologies. this paper reports a facile method for growth of small gold nanoparticles on the functionalized surface of larger silica nanoparticles. mono-dispersed silica particles and gold nanoparticles were prepared by...

This study examined the effect that silica content in diatom cells has on the behavior of protists. The diatoms Thalassiosira weissflogii and T. pseudonanawere cultured in high or low light conditions to achieve low and high silica contents, respectively. These cells were then fed to a heterotrophic dinoflagellate Noctiluca scintillans and a ciliate Euplotes sp. in single and mixed diet experim...

Occupational exposure to mineral dusts, such as silica, has been associated with progressive pulmonary inflammation, lung cancer, and fibrosis. However, the mechanisms involved in this process are poorly understood. Because p53 is a key transcription factor regulating many important apoptosis-related genes, we hypothesized that p53 may play a key role in silica-induced apoptosis and that abnorm...

Nowadays, the study of preparing silica/rubber composites, which can be used in “green 16 tire”, in energy saving method is fast-growing. In our work, silica modified by using alcohol 17 polyoxyethylene ether (AEO) and 3-Mercaptopropyltriethoxysilane (K-MEPTS) together were 18 investigated. Thermal gravimetric analyzer (TGA) result indicated that both AEO and K-MEPTS 19 could be grafted on the ...

Miners face a variety of respiratory hazards while on the job, including exposure to silica dust which can lead to silicosis, a potentially fatal lung disease. Currently, field-collected filter samples of silica are sent for laboratory analysis and the results take weeks to be reported. Since the mining workplace is constantly moving into new and often different geological strata with changing ...

Silica biomineralization associated with unicellular microbes (Cyanidium caldarium) living in strongly acidic hot springs were observed by electron microscopy. The unicellular microbes form green biomats undergoing photosynthesis in Kamuiwakka Falls, Hokkaido, Japan. The hot-spring water is strongly acidic, with pH less than 2, and rich in S. Electron microscopy observations showed that the cel...