Fine Structure of Remodeling Sites on Iliac Cancellous Bone in Senile Osteoporosis: A Study by Scanning Electron Microscopy Using an Improved Organic Specimen Preparation Method

We improved on the organic specimen preparation method in order to investigate the details of the functional state of bone in osteoporosis at high magnification level. The usefulness and possibilities of this method are discussed showing fine structural images of remodeling sites. Iliac bones of senile osteoporotic patients obtained by transilial biopsies were studied by scanning electron microscopy (SEM) using the improved preparation method. Excepting the region near the corticoendosteal surface, most of the iliac cancellous bone was composed of thin rod-shaped trabeculae. Remodeling sites on trabeculae appeared as concavities of various sizes and were easily distinguished from inert surfaces. The region near the cortico-endosteal surface showed a higher remodeling activity as compared with other regions. The morphological analysis of remodeling site by SEM made it possible to know its functional state. Five areas of different stages were distinguishable in remodeling sites, each corresponding to a different stage in the remodeling cycle: area in resorbing phase, in reversal phase, in early forming phase, in late forming phase, and in resting phase. The distribution patterns of the five areas in remodeling sites were investigated. More than half of the remodeling sites showed the heterogeneous composition: they were occupied by plural areas in different phases. Some remodeling sites were entirely occupied by a single area in reversal phase or in forming phase or resting phase. The remodeling site occupied by an area in resorbing phase alone was not found

Sulfur isotope ratios of some Roseki deposits in the Inner Zone of Southwest Japan

Sulfur isotope ratios of pyrite and alunite from 5 Roseki deposits in the Inner Zone of Southwest Japan were determined. The δ34S values of all pyrite samples were in the range from -13.2 to +2.3%, the variation range for each deposit being within 8%. In each deposit δ34S values of alunite were always higher than those of pyrite, which may be interpreted as that alunite was precipirated under more oxidizing conditions than pyrite. Sulfur isotope rations of the Roseki pyrite showed a distribution similar to that of ore sulfur from skarn and vein deposits in the same Zone. This suggests that the origin of sulfur of the Roseki deposits is also host igneous rocks

Discharge Phenomena of the Insulator Assembly and Occurrence of Critical Cascading Flashover Phenomena

This paper describes conditions for an occurrence of cascading flashover phenomena on the insulator assembly with the use of a high voltage transmission line by experiments in a laboratory room. The 154 kV suspension insulator assembly is employed as testing apparatus which consists of a chain of 9 standard suspension insulators equipped with an arcing horn. In the experiments, the apparatus is separated into two parts consisting of a bare insulator chain and a pair of arcing horns. The lightning impulse with positive polarity or negative are applied to the test pieces, and the over-voltage is used in those tests. Thus, the creeping flashover occurred with short lag time. The V-t curves and the 50% cascading flashover voltage were obtained and the prebreakdown phenomena were observed from the tests, then, it is concluded that the critical cascading flashovers occur with short time lag (T₀＝1.8 μ sec. or less) and a high steepness (1833 kV/μ sec. or more), and corona on the insulator surface starts from negative side electrode

Space Charge Measurement Using a Small Sphere as a Probe

A method for measuring the space charge produced by impulse corona in an air gap has been developed, using a small sphere as a probe. The probe is located far from the corona volume, and is connected to earth through resistance or capacitance. The probe induces a current or charge by electrostatic induction from the space charge. Since the induced charge on the probe is proportional to the space charge, it is possible to analyze the magnitude and polarity of the space charge from the probe signal. It is also possible to analyze the temporal variation caused by corona growth or movement of the space charge

Experimental Study of Critical Cascading Flashove on Insulator Assembly Using Model Arrangements (Part 1) : The Influence of a floating Electrode, Placed in the Air at Mid-Gap, on the Formation of a Flashover Path

This paper describes the phenomena of cascading flashovers in model arrangements for experimental analysis of critical cascading flashovers in an insulator assembly used on high voltage transmission lines. The testing model used consisted of a 15 cm gap length of rod-rod electrode which was 1.0 cm in diameter with a hemispherical end, with a potentially floating electrode which was a copper wire of 0.16 cm diameter. The applied lightning impulse voltage of positive or negative polarity was much higher than the breakdown voltage when the flashover occurred for only a short time lag. The experimental results included V-t curve and 50% flashover voltage characteristics for a gap on the testing model, flashover path, pre-breakdown corona distributions, and cascading flashover rates. The flashover phenomena in the air gap with a floating electrode clarified that the cascading flashover rate remained at a constant value whether the floating electrode existed or not. The coronas from the floating electrode were generated only when the coronas from the rod electrode reached the floating electrode. In order to form a cascading flashover, it was necessary that the bright leader coronas from the rod electrode grow toward the floating electrode, causing the coronas from the floating electrode to generate and meet the other coronas growing from the rod electrode

Behavior of The Space Charge Produced by The Positive Impulse Corona in Air

This paper describes the behavior of the space charge produced by the corona by applying the positive lightning impulse voltage to the rod-plane air gap. The relation between the amount of space charge and the injected charge from the rod electrode is discussed here. It was found that the amount of space charge became smaller than the injected charge for the corona highly developed so as to bridge the gap between the electrodes

Proposal and Performance Analysis of Hybrid NDN Based Ad Hoc Routing Combining Proactive and Reactive Mechanisms

This paper is an extension of our previous conference paper. In this paper, we propose a new routing protocol for named data networking (NDN) based ad hoc networks. One feature of our protocol is that it adopts a hybrid approach where a proactive routing is used in the producer side network and a reactive routing is used in the consumer side network. Another feature is that we focus only on the name prefix advertisement in the proactive routing. The result of performance evaluation focusing on the communication overhead shows that our proposal has a moderate overhead both for routing control messages and Interest packets compared with some of conventional NDN based ad hoc routing mechanisms proposed so far. The performance evaluation for a network configuration with a moving consumer node also shows the proposal realizes an effective content retrieval

Experimental Study of Critical Cascading Flashover on Insulator Assembly Using Model Arrangements (Part II) : The Influence of a Floating Electrode, Placed on a Porcelain Board, on the Formaiton of a Flashover Path

This paper describes the phenomena of cascading flashovers in model arrangements for experimental analysis of critical cascading flashovers occuring in an insulator assembly used on high voltage transmission lines. The testing model used consisted of a pair of rod-rod electrodes, a potentially floating copper wire and a porcelain board. The applied lightning impulse voltage of positive or negative polarity was much higher than the breakdown voltage, when the flashover occurred for only a short time lag. The experimental results included flashover paths and pre-breakdown corona distributions, and cascading flashover rates. The flashover phenomena on the testing model clarified that the cascading flashover rate was related to the position of the porcelain board with the floating wire and that the corona from the floating wire was generated just before the corona from the rod electrode reached the floating wire. In the summary, the influence of the floating electrode on the formation of flashover paths discussed in comparison with previous reports. As a result of this series of experiments, it was clarified that a cascading flashover occurred only through coexistence with the porcelain surface and floating metal

Pathologically Proven Intraocular Infiltration With Adult T-Cell Leukemia/Lymphoma: Two New Cases With Either Vitreous Opacity or Aqueous Hypopyon and Literature Review of 16 Cases

This study reported 2 new patients and 16 historical cases with pathologically proven intraocular infiltration with adult T-cell leukemia and lymphoma (ATLL) to know the timing of intraocular infiltration in the disease course. The first case was a 67-year-old woman who developed bilateral vitreous opacity about half a year after the onset of acute type of ATLL that had been unresponsive to chemotherapy. She underwent vitrectomy combined with cataract surgery in both eyes. She had bilateral optic disc atrophy and localized retinal white infiltrates in both eyes. Cytological examination of vitreous aspirates demonstrated medium-sized cells with aberrant flower-like convoluted nuclei, positive for CD3, and thus indicative of T-cells. The second case was a 38-year-old man who was diagnosed acute type of ATLL at the presentation of acute kidney injury. About half a year after initial chemotherapy and allogeneic hematopoietic stem cell transplantation, he developed aqueous hypopyon in the right eye, concurrent with cutaneous and central nervous system relapse. Aqueous tap disclosed class V abnormal cells. The aqueous “pseudohypopyon” resolved in response to another round of chemotherapy with mogamulizumab. In review of 18 patients, intraocular infiltration with ATLL was diagnosed by vitrectomy in 9, aqueous tap in 3, chorioretinal biopsy in 3, and autopsy in 3. The intraocular infiltration developed concurrently with systemic diagnosis of ATLL in 5 patients, but developed later after chemotherapy in 13. In conclusion, intraocular infiltration with ATLL appears rare, and pathological diagnosis by vitrectomy and aqueous tap would help determine therapeutic plan in relapse after chemotherapy

Decreased Prostaglandin E2 Production by Inflammatory Cytokine and Lower Expression of EP2 Receptor Result in Increased Collagen Synthesis in Keloid Fibroblasts

We investigated the metabolism of arachidonic acid in normal skin-derived fibroblasts (NF) as well as in keloid-derived fibroblasts (KF) in response to macrophage migration inhibitory factor (MIF), a pluripotent cytokine. We found that MIF enhanced cyclooxygenase-2 activity in NF more than in KF. Consistent with this finding, prostaglandin E2 (PGE2), an antifibrogenic molecule, was more significantly increased in NF than in KF by MIF treatment. As regarding E prostanoid receptor 2, the level of expression was significantly lower in KF than in NF. On the other hand, Forskolin, a direct activator of adenylcyclase, decreased collagen synthesis in both NF and KF, which indicates that cAMP plays an important role in regulating collagen synthesis. As PGE2 induces cAMP production, it is conceivable that increased collagen synthesis in KF might be owing to decreased PGE2 and cAMP production. These findings may aid in the development of a therapeutic strategy for the regulation of collagen synthesis in keloid fibroblasts