This test is usually recommended for women who have a higher risk of having a baby with Down syndrome or in response to risk detected by one of the previous tests. The mother's blood can be tested during pregnancy after 10 weeks gestation.iagnostic tests during pregnancy. If your screening test results are positive or worrisome, or you're at high risk of having a baby with Down syndrome, you might consider more testing to confirm the diagnosis. Your health care provider can help you weigh the pros and cons of these tests.
Original vs. Toluene Free. The Briwax Original formula contains the solvent Toluene and the Toluene Free formula contains the solvents Xylene and Naphtha. Solvents are necessary in the formulation of Briwax because without them Briwax would just be a hard chunk of wax, almost unusable.Toluene has a high aroma factor, a strong smell, and some people love it and some hate it. The Toluene Free formula has a much lower aroma; it smells more like a dry cleaning solvent.riwax Original uses toluene mainly because it dissolves the beeswax 100%. So even if Briwax is liquid it will still work as intended. Toluene is also an excellent grease and grime cleaner. As Briwax is used on old antique pieces, the solvent is really at work cleaning off the old oxidized surface.
Bromination on aromatic ring: toluene has one methyl group on aromatic group on benzene ring which imparts positive inductive effect and hyperconjugation. Because of these two effects, methyl groups increases the electron density on aromatic ring and acts as activating group.he methyl group on benzene ring in toluene is ortho and para directing and activating group due to hypercojugation and positive inductive effect of methyl group. Out of ortho and para products, ortho products are formed as major products around 63%, with para 34% and 3% meta products.