The phrase "a upon" is not correct and usable in written English.
It does not form a coherent expression and lacks clarity in meaning.
Example: "There is a upon the hill."
Alternatives: "on" or "at".
The formation of an oxodisulfonium ion intermediate 8 a upon mixing diaryl sulfoxide and Tf2O in equimolar amounts would be in accord with formation of Hendrickson's reagent under similar conditions (Scheme 3 b).
Sub-study A: Upon clinical examination, no test substance-related adverse effects were observed in any of the test groups.
Most people receive Medicare Part A upon reaching the age of 65.
In this system the expression takes the form where x, y, and z are the projections of A upon the coordinate axes.
As revived by Ms. Sokol, who more or less channels Brice's antic spirit, it reminds us that once a upon time the vaudeville stage was home to a kind of raw show business silliness that has all but disappeared in these more self-conscious times.
(a) Upon the formation of Ag NPs from different concentrations of AgNO3: (b) 1 mM, (c) 4 mM, (d) 10 mM, and (e) 15 mM.
The photooxidative behavior of a series of polybenzoxazines based on various amines with the same phenolic unit (bisphenol-A), upon exposure to ultraviolet (UV) radiation (λ>290 nm), is examined.
The reason for a differential release of sJAM-A upon inflammatory stimulation of different EC types currently remains unknown.
The expression of RCAN1.4 mRNA in response to VEGF-A upon collagen and gelatin matrices over a 24 hour period was determined using RT-qPCR (Fig. 8A).
However, it is clear that both albumin and fetuin-A, upon being boiled up to 30 minutes, retained their respective mineralization-inhibitory capabilities, a property that was lost upon more extensive boiling (120 min), at which point, seeding prevailed.
The major finding of this study is that in contrast to previously reported EC types, cultured human brain EC do not show an inducible release of sJAM-A under pro-inflammatory conditions, while the expression of cell-bound JAM-A upon pro-inflammatory stimulation is altered as previously described in other EC types.
