233 research outputs found

    Small sensor probe for measuring plasma waves in space Space science

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    Background: Since conventional one-point observations of plasma phenomena in space cannot distinguish between time and spatial variations, the missions on the basis of multiple-point observations have become the trend. We propose a new system for multiple-point observation referred to as the monitor system for space electromagnetic environments (MSEE). Findings: The MSEE consists of small sensor probes that have a capability to measure electromagnetic waves and transfer received data to the central station through wireless communication. We developed the prototype model of the MSEE sensor probe. The sensor probe includes a plasma wave receiver, the microcontroller, the wireless communication module, and the battery in the 75-mm cubic housing. In addition, loop antennas, dipole antennas, and actuators that are used for expanding dipole antennas are attached on the housing. The whole mass of the sensor probe is 692 g, and the total power consumption is 462 mW. The sensor probe can work with both inner battery and external power supply. The maximum continuous operation time on battery power is more than 6 h. We verified the total performance for electric field measurements by inputting signal to preamplifier. In this test, we found that analog components had enough characteristics to measure electric fields, and the A/D conversion and the wireless transmission worked correctly. In the whole performance for electric fields, the sensor probe has equivalent noise level of - 135 dBV/m/√Hz. Conclusions: We succeed in developing the prototype model of the small sensor probe that had enough sensitivity for electric field to measure plasma waves and the ability to transfer observation data through wireless communication. The success in developing the small sensor probe for the measurement of plasma waves leads to the realization of the multiple-point observations using a lot of small probes scattered in space

    Stormwater inflow loading of PAHs into urban domestic wastewater treatment plant for separate sewer system

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    Polycyclic aromatic hydrocarbons (PAHs) are common contaminants present in wastewater, and determination of their sources is important for their management in the environment. In this study, stormwater loading of PAHs during rainfall periods was evaluated for sewage inflow into a wastewater treatment plant for separate sewer system. To accomplish this, sewage inflow volumes, suspended solid concentrations, and PAH concentrations were measured during eight rainfall events and on two no-rainfall days at the inlet of the plant. Based on a comparison between the rainfall and no-rainfall loading quantified by the measurements, excess PAH loadings with stormwater were evaluated for the rainfall events. The relationship between rainfall intensity and stormwater loading was then used to evaluate long-term stormwater loadings of water and PAHs. Their contributions to the sewage inflow were 0.7 % and 1.0 % for one-year for water and the sum of 16 measured PAHs, respectively. Our measurements and estimates demonstrate that direct stormwater inflow is not a primary source of PAHs to the plant for this separate sewer system.This work was supported by Japan Society for the Promotion of Science KAKENHI Grant Numbers 19760372

    MRI of Rheumatoid Arthritis:Comparing the Outcome Measures in Rheumatology Clinical Trials (OMERACT) Scoring and Volume of Synovitis for the Assessment of Biologic Therapy

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    The outcome measures in rheumatology clinical trials (OMERACT) scores are the most mature quantitation system for rheumatoid arthritis (RA) on magnetic resonance imaging (MRI). Direct measuring techniques of synovial volume have been reported with good reproducibility, although few reports have demonstrated the changes of these measures in response to treatment. To assess these clinical responses, we evaluated the correlation of the changes of clinical activity score 28-joints disease activity score (DAS28-CRP) with the changes of OMERACT scores and with synovial volume measurements. Eight RA patients who were treated by biologic agents were examined with MRI of the dominant affected wrist and finger joints before and one year after the treatment. The total OMERACT score was reduced from 48.0 to 41.3, and synovial volume was reduced from 15.4 to 8.8 milliliters. Positive correlations were seen between the changes of DAS28-CRP and the changes of OMERACT synovitis score (r=0.27), OMERACT total score (r=0.43) and synovial volume (r=0.30). Limited to synovium assessment, synovial volume showed a better correlation with DAS28-CRP than the OMERACT synovitis score. On the other hand, the OMERACT total score showed a higher correlation with DAS28-CRP than synovial volume, probably because the OMERACT total score includes scores for bone erosion and bone edema as well

    Favorable Outcome of Repeated Salvage Surgeries for Rare Metastasis to the Ligamentum Teres Hepatis and the Upper Abdominal Wall in a Stage IV Gastric Cancer Patient

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    Gastric cancer with peritoneal metastases is typically a devastating diagnosis. Ligamentum teres hepatis (LTH) metastasis is an extremely rare presentation with only four known cases. Herein, we report salvage surgery of successive metastases to the abdominal wall and LTH in a patient originally presenting with advanced gastric cancer with peritoneal metastasis, leading to long-term survival. A 72-year-old man with advanced gastric cancer underwent curative-intent distal gastrectomy with D2 lymph node dissection for gastric outlet obstruction. During this procedure, three small peritoneal metastases were detected in the lesser omentum, the small mesentery, and the mesocolon; however, intraoperative abdominal lavage cytology was negative. We added cytoreductive surgery for peritoneal metastasis. The pathological diagnosis of the gastric cancer was tubular adenocarcinoma with pT4aN1pM1(PER/P1b)CY0 stage IV (Japanese classification of gastric carcinoma/JCGC 15th), or T4N1M1b stage IV (UICC 7th). Post-operative adjuvant chemotherapy with S-1 (TS-1)+cisplatin (CDDP) was administered for 8 months followed by S-1 monotherapy for 4 months. At 28 months after the initial surgery, a follow-up computed tomography (CT) detected a small mass beneath the upper abdominal wall. The ass showed mild avidity on 18F-fluorodeoxyglucose positron-emission (FDG-PET) CT. Salvage resection was performed for diagnosis and treatment, and pathological findings were consistent with primary gastric cancer metastasis. At 49 months after the initial gastrectomy, a new lesion was detected in the LTH with a similar level of avidity on FDG-PET CT as the abdominal wall metastatic lesion. We performed a second salvage surgery for the LTH tumor, which also showed pathology of gastric cancer metastasis. There has been no recurrence up to 1 year after the LTH surgery. With multidisciplinary treatment the patient has survived almost 5 years after the initial gastrectomy. Curative-intent gastrectomy with cytoreductive surgery followed by adjuvant chemotherapy for advanced gastric cancer with localized peritoneal metastasis might have had a survival benefit in our patient. Successive salvage surgeries for oligometastatic lesions in the abdominal wall and the LTH also yielded favorable outcomes

    Ni-Catalyzed Multi-Component Coupling Reaction of Aldimine,1,3-Diene, Alkyne, and Organozinc

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    Aldimines composed of aldehydes and primary amines react with 1,3-diene,alkyne, and Me_2Zn to furnish dienyl homoallylamines in the presence of Ni catalyst.In case of Ph_2Zn, alkyne serves as a spectator ligand to promote the three-component coupling reaction of Ph_2Zn, diene, and aldimine.Nagasaki Symposium on Nano-Dynamics 2008 (NSND2008) 平成20年1月29日(火)於長崎大学 Poster Presentatio

    Fast Iterative Reconstruction in MVCT

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    Statistical iterative reconstruction is expected to improve the image quality of computed tomography (CT). However, one of the challenges of iterative reconstruction is its large computational cost. The purpose of this review is to summarize a fast iterative reconstruction algorithm by optimizing reconstruction parameters. Megavolt projection data was acquired from a TomoTherapy system and reconstructed using in-house statistical iterative reconstruction algorithm. Total variation was used as the regularization term and the weight of the regularization term was determined by evaluating signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and visual assessment of spatial resolution using Gammex and Cheese phantoms. Gradient decent with an adaptive convergence parameter, ordered subset expectation maximization (OSEM), and CPU/GPU parallelization were applied in order to accelerate the present reconstruction algorithm. The SNR and CNR of the iterative reconstruction were several times better than that of filtered back projection (FBP). The GPU parallelization code combined with the OSEM algorithm reconstructed an image several hundred times faster than a CPU calculation. With 500 iterations, which provided good convergence, our method produced a 512 × 512 pixel image within a few seconds. The image quality of the present algorithm was much better than that of FBP for patient data
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