Innovative PEA space charge measurement systems for industrial applications

This article introduces new space charge measurement systems developed in Japan using the pulsed electroacoustics (PEA) method. The new methods include two types of 3-D systems, two types of transient systems for extremely high or low temperature, a small PEA unit for a portable system, and a mountable PEA unit that can be applied to another facility, such as a vacuum chamber. These new PEA systems should expand the applicable research field.     

Pharyngeal cross-sectional area and pharyngeal compliance in normal males and females

In the control of Functional Electrical Stimulation (FES) gait systems artificial sensors are used to provide the controller with feedback information. The sensors used range in complexity from simple heel or hand switches to tri-axial accelerometers. There are three basic problems connected with the selection of sensors: the type(s) of sensor(s) to be used, the number of sensors required and the optimum location of the sensor set. In general the choice of the sensor sets has been based on the availability of actual sensors and the experts understanding of where these sensors should be located. Using motion analysis data it is possible to construct an almost unlimited number of virtual sensors on any location of the body surface. Our aim was to develop this technique for construction of virtual sensors and compare these virtual sensors with their physical counterparts. Virtual goniometers, inclinometers, accelerometers and foot switches were constructed and compared with their physical counterparts. In addition visualisation tools were developed to aid in the choice of sensor location. There was a very good correlation between all the virtual and physical sensors. This technique gives flexibility to place virtual sensors almost anywhere on the body surface and also allows the construction of novel sensors.     

Ultrastructural characteristics of intercellular contacts and bile canaliculi in neonatal rat hepatocytes in primary culture

The ultrastructure of the cellular contacts and bile canaliculi was examined in cultured neonatal (day 5) rat hepatocytes to elucidate the development of cellular polarity. A new scanning electron microscopic technique for cultured hepatocytes allowed a view of cell-cell attachment and the entire cell surface, including the underside on plastic dishes. At 3 h after plating, neonatal hepatocytes were shown to be round, with loss of the preferential localization of cell organelles. After 6 h of culture, the cells had become oblong; they were aggregated in groups of several cells and the cellular contacts were not as rigid or as straight as those in adult hepatocytes. Transmission electron microscopy showed the biliary functional polarity to be like that in vivo. On the undersurfaces of adjacent neonatal hepatocytes a hemicanalicular structure lined with microvilli was found, which probably corresponds to the ultrastructure of bile canaliculi in vivo. However, no canaliculi or orifices of bile channels were found in adult hepatocytes. These results suggest that in neonatal rat hepatocytes the formation of tight rigid cellular contacts was suppressed. Modulation of cell membranes appeared on the undersurfaces of neonatal hepatocytes in early culture stages. The differences in the development of cellular polarity could be caused by the proliferating activity of neonatal hepatocytes.     

Metastasizing placental site trophoblastic tumor. An immunohistochemical and flow cytometric study of two cases

An immunohistochemical and flow cytometric DNA study of two cases of metastasizing placental site trophoblastic tumor are presented. One patient aged 29 died rapidly of widespread metastases despite hysterectomy and multiagent chemotherapy. The patient had a low level of serum HCG. The course was complicated by the presence of a nephrotic syndrome. The other patient aged 34 had a vaginal metastasis and high levels of serum HCG, and was alive without disease for 9 years after hysterectomy and chemotherapy. Histologically, these tumors were characterized by a monomorphic trophoblastic cell population, probably derived from intermediate trophoblast in the placental site. The mitotic rate in these tumors was 2-4/10 high-power fields. Immunohistochemically, many tumor cells contained human placental lactogen and placental alkaline phosphatase. Beta-unit chorionic gonadotropin was present in many cells of the second patient, and only focally in the first. All specimens including the curettaged and metastatic lesions revealed a diploid DNA content in both cases. Neither DNA ploidy nor S-phase fraction was associated with survival of patient. Since predicting the biologic behavior of placental site trophoblastic tumor is very difficult, making a correct diagnosis on endometrial curettings, hysterectomy, and monitoring serum HCG level is essential in patients with this tumor.     

Neutron Diffraction Study on the Structure of Na-Si-O-N Oxynitride Glasses

The local structure of a Na₂O─SiO₂ oxide glass and a Na₂O─iO₂─Si₃N₄ oxynitride glass has been investigated by the pulsed neutron diffraction method. In the oxide glass, the first peak of radial distribution function (RDF) curves appeared at 0.1627 nm corresponding to Si─O boxh length. In the oxynitride glass, the first peak of the RDF curve was shifted to longer distances at 0.1650 nm due to the coexistence of Si─O and Si─N boxhs. The first peak in the RDF curve of the oxynitride glass was deconvoluted into two peaks whose positions are located at 0.1626 and 0.1709 nm. The one at 0.1626 nm is ascribed to Si─O boxhs and the other at 0.1709 nm to Si─N boxhs. The number of silicon atoms around a nitrogen was found to be 2.42, suggesting that not all of the nitrogen atoms are boxhed to three silicon atoms, but 58% twofold (─N─) and 42% threefold (>N─) nitrogens coexist in the present Na-Si-O-N oxynitride glass. The formation of twofold nitrogens may arise from the reaction between ≡Si─O⁻ and ≡Si₃N groups. This model is compatible with the experimental observation that the density and Vickers hardness of oxynitride glasses increase with the nitrogen content.     

Broad-Band Coaxial Boosted Media Employing Negative-Impedance Junctions and Amplifiers

As an approach to the broad-band, multi-port, multilateral media with idealized transmitting ability for various communications, a "Flat Loss Boosted Coaxial Line" (FLB Line) with many ports, such a centipede, has been proposed. It has been built from Negativeresistance BridgedTtypesqrt{f}shape Boosters (FBA) with about 10 dB gain at 300 MHz and Negative-resistance Boosting Junctions (NBJ) with an effective gain of 4.8 dB and no directivity nor phase distortion. In this line, signal powers at all branching ports axe principally equal and are transmitted bilaterally over all frequency range, while maintaining not only sufficient stability margin but also allowable transmission performance. A trial 2 km line composed of 8 FLB sections and 3 NBJ units has demonstrated engineering feasibility that bidirectional transmission of 5 color TV signals. It operated with almost no ghosts and without any adjacent channel interferences over a frequency range from 5 MHz up to about 400 MHz.     

The Role of CaMKII and ERK Signaling in Addiction

Nicotine is the predominant addictive compound of tobacco and causes the acquisition of dependence through its interactions with nicotinic acetylcholine receptors and various neurotransmitter releases in the central nervous system. The Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) and extracellular signal-regulated kinase (ERK) play a pivotal role in synaptic plasticity in the hippocampus. CaMKII is involved in long-term potentiation induction, which underlies the consolidation of learning and memory; however, the roles of CaMKII in nicotine and other psychostimulant-induced addiction still require further investigation. This article reviews the molecular mechanisms and crucial roles of CaMKII and ERK in nicotine and other stimulant drug-induced addiction. We also discuss dopamine (DA) receptor signaling involved in nicotine-induced addiction in the brain reward circuitry. In the last section, we introduce the association of polyunsaturated fatty acids and cellular chaperones of fatty acid-binding protein 3 in the context of nicotine-induced addiction in the mouse nucleus accumbens and provide a novel target for the treatment of drug abuse affecting dopaminergic systems.