226 research outputs found

    Electrostatic Discharge Ground Test of a Polar Orbit Satellite Solar Panel

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    The Advanced Land Observing Satellite that was launched by the Japan Aerospace Exploration Agency in 2006 carries a large solar-array paddle of 22 times 3 m in polar orbit. The wake side of the solar paddle can be charged to a negative value exceeding -1000 V. Numerical simulations and laboratory experiments are carried out to investigate charging and arcing phenomena on the backside of the solar paddle that has exposed bypass diode boards and silver-Teflon thermal film. Possibility of secondary arc and surge voltage between hot and return ends of power circuit has been investigated. The authors irradiate solar-panel coupons with an electron beam to simulate charging situation near the North Pole. Surface flashover is observed once the insulator potential exceeds -7000 V. The authors have also tested charging situation near the South Pole where carbon fiber-reinforced plastics surface facing dense ionospheric plasma may arc easily once a satellite potential drops to -80 or -90 V. The solar-paddle design has been modified to increase the safety margin against arcing, and tests have been carried out to identify the strength limit under extremely harsh test environment

    mTORC1 signaling in primary central nervous system lymphoma.

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    BACKGROUND:Mammalian target of rapamycin (mTOR) complex 1 (mTORC1) acts as a downstream effector of phosphatidyl-inositol-3 kinase, which is frequently hyperactivated in glioblastoma multiforme and links to cell signaling in cellular proliferation, differentiation, metabolism, and survival. Although many studies have suggested the importance of mTORC1 in tumorigenesis, its role remains unclear in brain tumors other than glioblastoma.METHODS:In the present study, we evaluated the activation of mTORC1 in 24 cases of primary central nervous system lymphoma (PCNSL).RESULTS:Immunohistochemical analysis showed overexpression of Rheb, which is immediately upstream of mTORC1, in 20 cases of PCNSL. Immunohistochemical analysis also showed overexpression of phospho-4E-BP1 (Thr37/46) and phospho-S6 (Ser235/236), which are increased after mTORC1 activation as mTORC1 downstream effectors in 17 and 21 cases, respectively.CONCLUSION:Our data suggest that abnormal activation of the mTORC1 signaling pathway may cause tumor growth in patients with PCNSL

    Improvement in the productivity of xylooligosaccharides from waste medium after mushroom cultivation by hydrothermal treatment with suitable pretreatment

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    The effective xylooligosaccharides (XOs) production from the waste medium after mushroom cultivation (WM) was investigated. The WM contains rich nutrients (protein, etc.) which induce Maillard reaction with reducing sugars under hydrothermal conditions. To improve the productivity of XOs, the suitable pretreatment combined with washing and grinding was investigated, and subsequently hydrothermal treatment was demonstrated with batch type and continuous flow type reactor. The washing pretreatment with hot water of 60 degrees C was effective to remove nutrients from the WM, and it led to prevent brownish discoloration on the hydrothermal treatment. On the basis of experimental data, industrial XOs production processes consisting of the pretreatment, hydrothermal treatment and purification step was designed. During the designed process, 2.3 kg-dry of the purified XOs was produced from 30 kg-wet of the WM (15% yield as dry basis weight). Theoretical yield of XOs attained to 48% as xylan weight in the WM.ArticleBioresource Technology. 101(15):6006-6011 (2010)journal articl

    Coronary angioplasty ameliorates hypoperfusion-induced endothelial dysfunction in patients with stable angina pectoris

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    Objectives.This study sought to investigate the effect of coronary angioplasty on chronic hypoperfusion-induced endothelial dysfunction in patients with coronary heart disease.Background.The endothelium is an important component for organ flow regulation. Ischemia with or without reperfusion is known to cause endothelial dysfunction. We tested the hypothesis that chronic hypoperfusion impairs endothelial function in the angiographically normal coronary artery segment distal to stenosis and that the impairment by chronic hypoperfusion is reduced by coronary angioplasty.Methods.In 13 patients with stable angina pectoris, substance P (10, 30 and 100 pmol) and nitroglycerin (200 μg) were sequentially infused into the coronary artery in a cumulative manner on the day after coronary angioplasty. In 10 of these patients, vascular responses to these agents were again investigated 3 months after angioplasty. Changes in vascular diameter were evaluated in vessels located proximal and distal to the target lesion, both of which were angiographically normal, by performing computer-assisted quantitative coronary angiography. In five patients, the transstenotic pressure gradient was also measured with a pressure sensor-mounted guide wire before angioplasty.Results.On the day after angioplasty, the magnitude of dilation by substance P in distal segments was significantly less than that in proximal segments and inversely correlated with the transstenotic pressure gradient (p < 0.05) and lesion stenosis (p < 0.05). There was no difference in nitroglycerin-induced vasodilation between the two vessel segment groups. Three months later, the impaired response to substance P in the distal segment was restored to normal.Conclusions.We conclude that chronic hypoperfusion impairs endothelium-dependent dilation of coronary artery distal to critical stenosis in patients with ischemic heart disease and that coronary angioplasty ameliorates the endothelial dysfunction within 3 months

    Visualizing Trimming Dependence of Biodistribution and Kinetics with Homo- and Heterogeneous N-Glycoclusters on Fluorescent Albumin

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    A series of N-glycans, each sequentially trimmed from biantennary sialoglycans, were homo- or heterogeneously clustered efficiently on fluorescent albumin using a method that combined strain-promoted alkyne-azide cyclization and 6π-azaelectrocyclization. Noninvasive in vivo kinetics and dissection analysis revealed, for the first time, a glycan-dependent shift from urinary to gall bladder excretion mediated by sequential trimming of non-reducing end sialic acids. N-glycoalbumins that were trimmed further, in particular, GlcNAc- and hybrid biantennary-terminated congeners, were selectively taken up by sinusoidal endothelial and stellate cells in the liver, which are critical for diagnosis and treatment of liver fibrillation. Our glycocluster strategy can not only reveal the previously unexplored extracellular functions of N-glycan trimming, but will be classified as the newly emerging glycoprobes for diagnostic and therapeutic applications

    Diagnosis of demyelinating brain lesion simulating brain tumors on fast imaging employing steady-state acquisition magnetic resonance imaging.

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    Background:A single inflammatory demyelinating brain lesion sometimes mimics a brain tumor on conventional magnetic resonance imaging (MRI), and thus poses a considerable diagnostic challenge. We assessed the usefulness of a new MRI technique, fast imaging employing steady-state acquisition (FIESTA), for the diagnosis of inflammatory demyelinating disease (IDD).Methods:Three patients (2 males, 1 female) with a histopathologically proven inflammatory demyelinating brain lesion which mimicked a brain tumor on MRI were evaluated with a post-contrast three-dimensional FIESTA sequence before biopsy and treatment. Those images were compared with the images of intra-axial brain tumors (n = 147).Results:Preoperative FIESTA showed an iso- or slightly hyperintense distinct intralesional structure that appeared reticulate or broad-line in patients with IDD. These structures traversed a hyperintense demyelinating lesion in the deep grey matter (DGM) and were connected to the surrounding extralesional area, which appeared to be dense fibers between DGM. Such distinct intralesional structures were not observed in most brain tumors.Conclusion:Reticulate or broad-line-like intralesional structures on FIESTA may, therefore, be suggestive of IDD rather than indicate a brain tumor

    Impact of frailty on long-term mortality in older patients receiving intensive care via the emergency department

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    The aim of this study was to evaluate whether frailty was associated with 6-month mortality in older adults who were admitted to the intensive care unit (ICU) with an illness requiring emergency care. The investigation was a prospective, multi-center, observational study conducted among the ICUs of 17 participating hospitals. Patients >= 65 years of age who were admitted to the ICU directly from an emergency department visit were assessed to determine their baseline Clinical Frailty Scale (CFS) scores before the illness and were surveyed 6 months after admission. Among 650 patients included in the study, the median age was 79 years old, and overall mortality at 6 months was as low as 21%, ranging from 6.2% in patients with CFS 1 to 42.9% in patients with CFS >= 7. When adjusted for potential confounders, CFS score was an independent prognostic factor for mortality (one-point increase in CFS, adjusted risk ratio with 95% confidence interval 1.19 [1.09-1.30]). Quality of life 6 months after admission worsened as baseline CFS score increased. However, there was no association between total hospitalization cost and baseline CFS. CFS is an important predictor of long-term outcomes among critically ill older patients requiring emergent admission
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