"at chair" is not correct or usable in written English.
You would need to add a word or phrase to make it meaningful. For example: "Sitting at the chair, she enjoyed her morning coffee."
Anxiety, pain sensation, and pain distress were measured with visual analogue scales at chair rest initiation and 30 min later.
The objective of this study was to quantitatively determine, at chair side, the serum C-reactive protein (CRP) levels in dental emergency patients.
They're not quite finished with the chair rail — molding at chair height to prevent a pushed-back chair from marring the wall.
Bombus is the brainchild of Amelia Coward and Lee Hunnisett de Beer, and their wrapped pieces started out as a window display at Chair.
This particular meme, which has spread rapidly on social networks like Twitter and Facebook, shows the cantankerous character Grampa Simpson in a newspaper clipping, shaking his fist in a photograph beneath the headline "Old Man Yells at Chair".
LONDON — "When I see them, I remember every single dress," says Valentino, as he walks down the runway, looking at chair labels in the audience reading "Jennifer Lopez" or "Carla Bruni".
He added dimension subtlety to smooth walls with white wood stripping at chair-rail height and again close to the ceiling.
At some point most designers try their hand at chairs.
"But Win is very good at chairing meetings".
TruthTeller knocks into the furniture as he goes, kicking at chairs.
"Nearly all our stuff is scavenged from somewhere, but I draw the line at chairs you can't sit on".
