Silicon (Si) is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4), as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, h...

PURPOSES The aim of this study was to analyse clinical data of children undergoing orthokeratology (ortho-k) and to investigate patients'/parents' perspective on ortho-k via telephone interviews. METHODS Clinical records of children undergoing ortho-k from a university optometry clinic were reviewed and the effects of ortho-k on refraction, vision and cornea were investigated. A telephone int...

hydrogen is an unusual substance in that its molecule exists in two forms, known as ortho and para, with markedly different properties. energy level of the ortho molecule is higher than para, therefore, the latter is employed for industrial purposes. consequently, for a high  conversion of  ortho to para hydrogen a catalyst reactor must be employed.  therefore, one of  the main objectives of th...

We discuss the ratio of orthoto para-H2 in photodissociation regions (PDRs). We draw attention to an apparent confusion in the literature between the ortho-to-para ratio of molecules in FUV-pumped vibrationally excited states, and the total H2 ortho-to-para abundance ratio. These ratios are not the same because the process of FUV-pumping of fluorescent H2 emission in PDRs occurs via optically t...

BACKGROUND Women of childbearing age represent a growing proportion of people living with HIV. Preventing pregnancy is important in HIV-infected women receiving efavirenz as part of their antiretroviral therapy. METHODS The effects of coadministration of efavirenz (600 mg once daily) on the pharmacokinetics (PK) of the active components (ethinyl estradiol [EE] and 17-deacetyl norgestimate [NG...

mgo nanopartticels (np-mgo) in average size between 30—130 nm were prepared by sonochemistry method. some phenols have been converted to ortho-hydroxybezaldehyd by ortho-formylation using mgo nanoparticles and (ch2o)n in xylene and subsequently treated with aqueous nh2oh.hcl, affording the corresponding aldoxime in a one-pot procedure. moreover, this one-pot process, with two transformations, o...

Simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho-ortho, ortho-para, or para-para homo-couplings of phenols are described. In addition, chromium salen catalysts have been discovered as uniquely effective in the cross-coupling of different phenols with high chemo- and regioselectivity.

Installing subsurface tile drain systems in poorly drained claypan soils to improve corn ( L.) yields could potentially increase environmental phosphorus (P) loss through the tile drainage system. The objectives of the study were to quantify the average concentration and loss of ortho-P in tile drain water from a claypan soil and to determine whether managed subsurface drainage (MD) could reduc...

Nitration of N-acetyl anilides using a simple combination AgNO3 and K2S2O8 as stable nitro source an oxidant, respectively, was explored. The reaction practical to operate proceeded under considerably mild conditions (reflux in acetonitrile) within acceptable time (6 h). para-substituted gave only ortho-nitrated products moderate good yields (30–63% yields). ortho-, meta-, or non-substituted mi...