Kihoon Eom

Primo-vessels and Primo-nodes in Rat Brain, Spine and Sciatic Nerve

We report a method using Trypan blue staining to detect primo-vessels in the nervous system on internal organs or in the skin of rat. We applied this technique to visualize the primo-vessels and primo-nodes in the brain, spinal cord and sciatic nerve of a rat. Primo-vessels and primo-nodes were preferentially stained at nerves, blood vessels, or fascia-like membranes and turned blue after the spread and washing of Trypan blue. The physiological role of the primo-vessels within the nervous system is an important question warranting further investigation.

Putative Primo-vascular System in Mesentery of Rats

Primo-vessels have been observed in the rat abdominal cavity as floating thread like structures on and not adhering to fascia-wrapped internal organs. To date their presence, locations, and lengths have been irregular and unpredictable, and their identification not regularly repeatable, thus they have remained a nagging enigma in primo-vascular system research for several years. In this work, locations were found where primo-vessels were regularly present and observed repeatedly. These vessels were not floating or freely movable but lay in a regular position in the mesentery in the abdominal cavity of the rat, being observed between the cecum and small intestine and between the colon and mesentery root. The difference between a lymph vessel and a primo-vessel is described in anatomical and histological aspects. In addition, trypan blue was found to enter primo-vessels through the surrounding membranes and filled spaces between fibers comprising the primo-vessels. It is conjectured that the previously observed floating primo-vessels had anomalously and irregularly emerged, for some unknown physiological reasons, from primo-vessels normally located in the fascia-like mesentery.

Novel Threadlike Structures on the Surfaces of Mammalian Abdominal Organs are Loose Bundles of Fibrous Stroma with Microchannels Embedded with Fibroblasts and Inflammatory Cells

Novel threadlike structures (NTSs) on the surfaces of mammalian abdominal organs have recently attracted interests regarding their ability to transport fluid, enable cell migration, and possibly facilitate cancer metastasis. Nevertheless, histological studies of NTSs have been sporadic and often have inconsistent interpretations of the NTS internal structure. In this article, we provide a synthetic and consistent view of the NTS internal structure: the NTS is a loose bundle of fibrous stroma that forms interstitial channels and microsinusoids infiltrated with inflammatory cells. The fibroblasts are embedded in the stroma and mostly aligned along the major axis of the NTS. The sinusoids, which are in inconsecutive cross sections, have boundaries more or less delineated by extracellular fibers, partly surrounded by endothelial-like cells, or both. We compare these morphological features to other well-known connective tissues (i.e., trabecular meshwork and lymphatic capillary) and discuss the biomechanical and biological functions of NTSs based on their structural characteristics.

Sol-gel synthesis of Sc 2 O 3 doped W nano-particle for cathode application

Sc2O3 doped W nano-powder is believed to play a dominant role for improving emission capabilities of the high current density thermionic cathodes. In this study a novel nano-particle synthesis approach was adopted in order to precisely control the particle parameters. The particle characteristics and sintering behavior has been analyzed using SEM, TEM, EDS, XRD and XPS. Uniform grain size with average particle diameter~50 nm, spherical morphology, uniform phase and homogeneous mixing of Sc2O3 doped W nano-powder was obtain which will enhance the emission current density, emission uniformity and life of the cathode.

Effect of surface roughness of high current density nano-particle cathode for terahertz vacuum devices application

High current density dispenser cathode is critical need for used in high power terahertz devices. Recently scandate cathode using nanoparticle offers very high current density more than 100 A/cm2. Fabrication of this kind of cathode is challenging issue due to its nano dimension of the particle size. One of the critical parameter is surface roughness of the emission surface. We develop dispenser cathode using tungsten nano-particle of average particle diameter ~50 nm, spherical morphology and uniform phase. In this paper we explain the effect of surface roughness on the emission current density of the dispenser cathode.