Showing papers by "Pacific Northwest National Laboratory published in 1975"

Scanning electron microscopy of human reproductive physiology.

Abstract: Recent findings on the scanning electron microscopical (SEM) structures of epithelium of female and male reproductive organs spermatozoa placenta amniotic cells umbilical cord neonatal blood cells and pathologies of their structures - carcinoma of the endometrium cervix vagina and vulva - are reviewed. The methodology in preparation of soft tissue cervical mucus and amniotic tissues is described including pinning fixation dehydration and drying mounting and metal coating and viewing with the SEM. There are striking morphological differences between the tissue organization of the mucosa of different segments of the reproductive tract. These morphological di fferences are discussed in terms of observed physiological functions. SEM is a useful tool in studying infertility the status of the newborn monitoring fetal maturity and carcinoma diagnosis.

Synthesis of polytertiary phosphines and ‘mixed’ phosphorus–sulphur and ‘mixed’ phosphorus–nitrogen polydentate ligands via free-radical catalysis

Abstract: In the presence of free radicals, phosphorus–hydrogen and sulphur–hydrogen bonds cleanly and readily add to the carbon–carbon double bonds of vinyl derivatives to produce organic compounds that are useful as polydentate chelating ligands. The generality and mild conditions of the reaction are demonstrated by the synthesis of di-, tri-, and tetra-(tertiary phosphines) and of compounds that contain both phosphorus and sulphur or phosphorus and nitrogen donor groups. This free-radical-catalysed addition of molecules containing P–H and S–H bonds to vinyl compounds provides a general valuable alternative to the base-catalysed addition method.

Recent Advances in Gas Scintillation Proportional Counters

Abstract: Various geometrical configurations for gas scintillation proportional counters have been investigated in order to determine which is best for use in a large volume, high efficiency counter for measuring low energy gamma and x-rays. A xenon filled counter having a rod anode inside a cylindrical cathode appears to provide the best configuration for providing a uniform field and the best resolution over the total volume of the counter. The details of construction and operating characteristics of various shaped counters are described.