strange units in Brain Research

[fernando boix]

In article <30jksm$fob at news.u.washington.edu>, dfitts at u.washington.edu (Douglas Fitts) says:
>
>An article in Brain Research uses some units I've never run into before,
>and I've exhausted my limited resources in my office and my colleagues'
>offices.  The authors are from Leipzig, Munich, and Quebec if that's a
>clue. 
>
>Apparently referring to concentrations of tritiated amino acids and 
>glucose or 14C tagged mannitol, etc., the authors use the units:
>
>TBq mmol(-1)  and GBq mmol(-1)
>
>where (-1) is of course an exponent.  What are these TBq and GBq?
>I'm guessing T is tera and G is giga.  I've no clue as to the Bq.

Despite I'm not working with radioactive materials, I can imagine that Bq 
is for becquerel, the SI-unit of radioactivity (one Bq corresponds to one
spontaneous nuclear transition per second). So, the units employed in the article 
may be tera and gigabecquerel per milimol.

>Later, referring to a permeability surface area product (the paper is 
>about transfer across the blood-brain barrier) they use the units:
>
>ml/hg/min
>
>I've often seen the PS product as ml/g/min, but what's 'hg'?

"h" is the prefix for hecto-, so that "hg" may correspond to hectogram
 (=100 grams). These units have to been read as mililitre per 100 grams per
minute.

For such kind of problems, I would recomend the book: Basic Facts for Basic
Science, by Radovan Zak (Raven Press, New York).