44 research outputs found

    Simultaneous Measurements of Proton Ratio and Beam Divergence of Positive-ion-based Neutral Beam in the Large Helical Device

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    A spectroscopy system was installed on the diagnostic neutral beam injector in LHD. The Hα lines spectrum emitted by full, half and one-third energy component are clearly observed, and the proton ratio and the beam divergence were estimated by the line intensity and the line width, respectively. The proton ratio of 85?90 % is achieved in high arc power discharge. The beam divergence of them shows their minimum with the same perveance. It was experimentally confirmed that the spectroscopy system is useful for the monitor of the proton ratio and the divergence of the beam

    Spatial resolved high-energy particle diagnostic system using time-of-flight neutral particle analyzer in Large Helical Device

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    The time-of-flight-type neutral particle analyzer has an ability of horizontal scanning from 40 to 100° of the pitch angle. The information from the spatially resolved energy spectrum gives not only the ion temperature but also the information of the particle confinement and the electric field in plasmas. We have been studying the energy distributions at various magnetic configurations in the neutral beam injection (NBI) plasma. The spatially resolved energy spectra can be observed during long discharges of the NBI plasma by continuous scanning of the neutral particle analyzer. The shape of spectra is almost similar from 44° to 53°. However, the spectra from 55° are strongly varied. They reflect the injection pitch angle of the beam. The pitch angle scanning experiment during the long discharge of NBI plasma has also been made under the reversal of the magnetic field direction. NBI2 becomes counter injected with the reversal. We can easily observe the difference between co- and counter injections of NBI. During the electron cyclotron heating in the low-density plasma for the formation of the internal thermal barrier, large neutral particle increase or decease can be observed. The degree of the increase/decrease depends on the energy and the density. The reason for the variation of the particle flux is that the orbit of the trapped particle changes due to the electric field formed by the strong electron cyclotron heating

    High Energy Particle Measurements during Long Discharge in LHD

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    The spatial resolved energy spectra can be observed during a long discharge of NBI plasma bycontinuously scanning the neutral particle analyzer. In these discharges, the plasmas are initiated by the ECH heating, after that NBI#2 (Co-injection) sustains the plasma during 40-60 seconds. The scanned pitch angle is from 44 degrees to 74 degrees. The injected neutral beam (hydrogen) energy of NBI#2 is only 130 keV because the original ion source polarity is negative. The shape of spectra is almost similar from 44 degrees to 53 degrees. However the spectra from 55 degrees are strongly varied. It reflects the injection pitch angle of the beam according to the simulation (53 degrees ot R* = 3.75 m in simulation). The beam keeps the pitch angle at incidence until the beam energy becomes to the energy, which the pitch angle scattering is occurred by the energy loss due to the electron collision. The low flux region can be observed around 10-15 keV, which is 15 times of the electron temperature. The energy region may be equal to the energy at which the pitch angle scattering is occurred. At the energy, the particle is scattered by the collision with the plasma ions and some of particles may run away from the plasma because they have a possibility to enter the loss cone. According to the simulation, the loss cone can be expected at the 10 keV with the small angular dependence. The depth of the loss cone is deep at the small pitch angle. The hollow in the spectrum may be concluded to be the loss cone as the tendency is almost agreed with the experimental result

    Impurity emission characteristics of long pulse discharges in Large Helical Device

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    Line spectra from intrinsic impurity ions have been monitored during the three kinds of long-pulse discharges (ICH, ECH, NBI). Constant emission from the iron impurity shows no preferential accumulation of iron ion during the long-pulse operations. Stable Doppler ion temperature has been also measured from Fe XX, C V and C III spectra

    Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

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    he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix

    Damage control surgery for unstable thoracic wall injury

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    Damage control surgery (DCS) consists of three steps: an abbreviated initial operation, resuscitation in the ICU, and a planned reoperation. Although DCS for lung and heart injury have been established, there is no concept of DCS for the chest wall. We experienced a successful case, in which a DCS of chest wall lifting procedure and internal pneumatic stabilization were performed on the flail chest accompanied by a remarkable destruction of chest wall. As a result, the patient's abnormal breathing improved. Surgical fixations using KANI plate were performed at a later date. We suggest that the chest wall lifting procedure may be suitable as a DCS for thoracic cage destruction from severe chest wall injury. Keywords: Damage control surgery, Thoracic wall destruction, Rib fracture, Surgical stabilizatio

    First establishment of a new table-rotated-type hybrid emergency room system

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    Abstract The hybrid emergency room (hybrid ER) system was first established in 2011 in Japan. It is defined as an integrated system including an ER, emergency computed tomography (CT) and interventional radiology (IVR) rooms, and operating rooms. Severe trauma patients can undergo emergency CT examinations and therapies (surgeries) without being transferred. The hybrid ER system is attracting attention because trauma resuscitation using this system has been reported to potentially improve the mortality rate in severe trauma patients. In August 2017, we established a new table-rotated-type hybrid ER to facilitate surgical functions. Herein, we introduce a new table-rotated-type hybrid ER consisting of an IVR–CT–operating room system and discuss its efficiency and feasibility for trauma resuscitation, including surgery and IVR. This system includes four new concepts: (1) to secure a wide working space during trauma resuscitation by reconsidering the arrangement of the C-arm, (2) ensure an air-conditioned operating room in the hybrid ER, (3) adopt an operating table but not interventional radiology table, and (4) prepare a trauma bay with three additional beds for multiple victims. This hybrid ER system also adopted the rotated-type table to secure a wide working space during the resuscitation phase. The C-arm was located away from the patients and placed on the wall opposite to the CT gantry, in contrast to that in previous systems. If patients needed an emergency IVR, the table was just rotated, and the IVR could be conducted immediately. This improvement can secure a wide working space in the hybrid ER. Moreover, the patient table was also a surgical operating table, and the hybrid ER system had an air-conditioned operating room (class 10,000). In the anticipation of many trauma patients being transported to the ER, a new trauma bay with three additional beds next to the hybrid ER was established, which also had an air-conditioned operating room. This new rotated-type hybrid ER system facilitates efficient surgical functions during trauma resuscitation and can secure a wide working space for the medical team to immediately perform resuscitative procedures and IVRs without delay

    Increased Regulatory T Cells and Decreased Myeloid-Derived Suppressor Cells Induced by High CCL17 Levels May Account for Normal Incidence of Cancers among Patients with Atopic Dermatitis

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    The incidence of cancers in atopic dermatitis (AD) is not increased, although the Th2-dominant environment is known to downregulate tumor immunity. To gain mechanistic insights regarding tumor immunity in AD, we utilized CCL17 transgenic (TG) mice overexpressing CCL17, which is a key chemokine in AD. Tumor formation and lung metastasis were accelerated in CCL17 TG mice when melanoma cells were injected subcutaneously or intravenously. Flow cytometric analysis showed increases in regulatory T cells (Tregs) in lymph nodes in CCL17 TG mice with high mRNA levels of IL-10 and Foxp3 in tumors, suggesting that Tregs attenuated tumor immunity. The frequency of myeloid-derived suppressor cells (MDSCs), however, was significantly decreased in tumors of CCL17 TG mice, suggesting that decreased MDSCs might promote tumor immunity. Expression of CXCL17, a chemoattractant of MDSCs, was decreased in tumors of CCL17 TG mice. Depletion of Tregs by the anti-CD25 antibody markedly reduced tumor volumes in CCL17 TG mice, suggesting that tumor immunity was accelerated by the decrease in MDSCs in the absence of Tregs. Thus, CCL17 attenuates tumor immunity by increasing Tregs and Th2 cells, while it decreases MDSCs through reductions in CXCL17, which may work as a “safety-net” to reduce the risk of malignant tumors in the Th2-dominant environment
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