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A Andre

Publications and source records attributed to A Andre.

32 records · Page 2Linked to original sources
PubMed1974

Nucleoside conformations. 15. Flexibility of natural pyrimidine nucleosides around the glycosidic bond.

The flexibility of pyrimidine nucleosides has been investigated by measuring their circular dichroism in hydroalcoholic solutions over a large temperature range (-100 degrees to +40 degrees C). It was observed that ss-Uridine (Urd) and ss-Cytidine (Cyd) showed a decrease of the main dichroic band of about 40 percent, while sterically hindered nucleosides (alphaUrd, ara-Uracile, 02-2' anhy-dro-Urd, 2'3'-0-isopropylidene-Urd) showed only small decreases. It is concluded that the flexibility of the glycosidic linkage in conjunction with the pseudo-rotation of the sugar residue is responsible for these changes; the thermodynamic values which can be deduced from these decreases are compatible with an oscillatory motion around the glycosidic bond, but exclude anti-syn transformations in pyrimidine nucleosides.

Circular Dichroism↗
PubMedDate not supplied

Identification of blood stains by non-genetic characteristics: the HBs antigen of viral hepatitis B.

In forensic cases, until recently, identification of biological stains was based on the use of genetic markers, such as blood groups. In this paper, we show that another acquired characteristic, even if not immutable during life, may afford similar possibilities. As an example, we have demonstrated that the HBs antigen, associated with the hepatitis B virus, can help in the identification of bloodstains. The requisite condition for using this new marker, is that not too much time should elapse between the time the biological stains are formed and the moment when victim and suspected individual are examined for comparison of their blood with the stain. We have shown that in a dried state, the HBs antigen is very stable for a least six months. In vivo, it persists for a few week to 6 or 7 years according to thecase. HBs antigen is a relatively rate factor, its frequency being 0.5%ew marker, is that not too much time should elapse between the time the biological stains are formed and the moment when victim and suspected individual are examined for comparison of their blood with the stain. We have shown that in a dried state the, HBs antigen is very stable for a least six months. In vivo, it persists for a few week to 6 or 7 years according to the case. HBs antigen is a relatively rate factor its frequency being 0.5% in the Belgian population; the frequency reaches 2 to 3% in the Mediterranean population who constitute most of the immigrants in Belgium.

Blood Stains↗