In situ FTIR reaction analysis of pharmaceutical-related chemistry and processes.

The potential for the production of increasing numbers of drug candidates as a result of combinatorial techniques, coupled with the necessity of striving for safer, more efficient processes, poses a special challenge and opportunity to the development chemist and engineer. In support of this quest for better molecules and processes, in situ analytical methodologies are becoming an ever-important ally. In particular, in situ FTIR spectroscopy is providing a wealth of information about reaction kinetics, pathways and mechanisms for a wide range of chemistry in both academic and industrial laboratories. This review article provides an historic perspective on the use of in situ FTIR spectroscopy and covers the recent literature published as a variety of pharmaceutical-related topics.

Raman scattering as a characterization tool for epitaxial GaN thin films grown on sapphire by turbo disk metal-organic chemical vapor deposition.

Thin layers of GaN, a few micrometers thick, grown on sapphire substrate, are the basic structure in the rapidly developing GaN-based blue optoelectronics devices. We are looking for nondestructive, effective, and convenient characterization tools for GaN/sapphire. Ordinary Raman scattering measurements have limited use because strong Raman signals from the sapphire substrate overwhelm the GaN Raman features. We describe two techniques for making commercial laser Raman systems serve as convenient characterization tools for GaN/sapphire. One uses a near right-angle laser beam incidence, and the other uses microscope lens focusing. In these two ways the detected GaN Raman signals are much stronger than sapphire features, and correct assignments can be made quickly.

Direct fetal blood examination for prenatal diagnosis of homozygous familial hypercholesterolemia.

Prenatal diagnosis of homozygous hypercholesterolemia was achieved at the 24th week of gestation by analysis of lipid values in a fetal blood sample obtained by a needle guided by ultrasound. These abnormal values were compared to values in blood obtained from normal fetuses at the same stage of gestation. After abortion, the diagnosis was confirmed by measuring LDL receptor activity on fibroblast cultures from a skin biopsy. The main advantages of this procedure over measuring LDL receptor activity on cultured amniotic cells are its simplicity and speed.