91 research outputs found

    Evaluation of atherosclerotic lesions using dextran- and mannan–dextran-coated USPIO: MRI analysis and pathological findings

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    Magnetic resonance imaging (MRI) can detect atherosclerotic lesions containing accumulations of ultrasmall superparamagnetic iron oxides (USPIO). Positing that improved USPIO with a higher affinity for atherosclerotic plaques would yield better plaque images, we performed MRI and histologic studies to compare the uptake of dextran- and mannan–dextran-coated USPIO (D-USPIO and DM-USPIO, respectively) by the atherosclerotic walls of rabbits. We intravenously injected atherosclerotic rabbits with DM-USPIO (n = 5) or D-USPIO (n = 5). Two rabbits were the controls. The doses delivered were 0.08 (dose 1) (n = 1), 0.4 (dose 2) (n = 1), or 0.8 (dose 3) (n = 3) mmol iron/Kg. The dose 3 rabbits underwent in vivo contrast-enhanced magnetic resonance angiography (MRA) before and 5 days after USPIO administration. Afterwards, all animals were euthanized, the aortae were removed and subjected to in vitro MRI study. The signal-to-noise ratio (SNR) of the aortic wall in the same region of interest (ROI) was calculated in both in vivo and in vitro studies. Histological assessment through measurement of iron-positive regions in Prussian blue-stained specimens showed that iron-positive regions were significantly larger in rabbits injected with DM- rather than D-USPIO (P < 0.05) for all doses. In vivo MRA showed that the SNR-reducing effect of DM- was greater than that of D-USPIO (P < 0.05). With in vitro MRI scans, SNR was significantly lower in rabbits treated with dose 2 of DM-USPIO compared with D-USPIO treatment (P < 0.05), and it tended to be lower at dose 3 (P < 0.1). In conclusion, we suggest that DM-USPIO is superior to D-USPIO for the study of atherosclerotic lesions in rabbits

    Effect of Zinc Acetate Dihydrate (NobelzinR) Treatment on Anemia and Taste Disorders in Patients with Chronic Kidney Disease with Hypozincemia

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    Some patients with chronic kidney disease (CKD) receiving hemodialysis develop erythropoietin-resistant anemia, possibly due to zinc deficiency. The frequency of zinc deficiency in CKD (stages 1-5 and 5D) and CKD improvement via zinc supplementation are not completely verified. Here 500 CKD patients (Stage 1/2, n=100; Stage 3, n=100; Stage 4, n=100, Stage n=5, 100; Stage 5D, n=100) will be recruited to determine the frequency of serum zinc deficiency at each CKD stage. Patients with serum zinc concentrations <80 μg/dL will be treated with zinc acetate dihydrate (NobelzinR) to evaluate its effects on hypozincemia, taste disturbances, and anemia

    能登半島西方海域における3次元地質構造モデル

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    In the sea area off the west coast of the Noto Peninsula, there are faults and flexures that have been formed since the Tertiary Period. It is also the area in which the magnitude 6.9 Noto Hanto earthquake occurred on March 25th 2007. Many acoustic surveys have been carried out and have revealed the vertical cross-sections of subsurface sedimentary structures in this area. In this study, we compiled the boundary depths of the sedimentary structures, together with the distribution of faults and flexures, and created a three-dimensional (3D) depth distribution of the boundaries of the subsurface geological structures formed since the Tertiary Period in this area. The obtained 3D depth distribution of the boundaries illuminates the distribution of the flexure structure in the sea area off the city of Hakui at each boundary. We recognized that the boundary depths change steeply for the Quaternary Period reverse faults that lie relatively close to the coast, while little for the faults far from the coast

    シンケイ センイショウ 1ガタ ノ セキチュウ ヘンケイ ニ トモナウ ロッコツ ズ ノ セキチュウカン ナイ ダッキュウ

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    2006 年4 月~2010 年3 月の神経線維腫症1 型に伴う脊柱変形手術例10 例中3 例に肋骨頭の脊柱管内脱臼がみられた.症例1 は6 歳の男児でT4-8:74°,T8-11:72° の側弯があり,左第4 と第5 肋骨頭の脊柱管内への陥入を認めた.症例2 は11 歳の男児でT3-7:100° の側弯とT3-T9:90° の後弯があり,左第6 肋骨頭が脊柱管内へ脱臼し,脊髄を圧排していた.症例3 は27 歳の女性でT6~9:73°,T9~12:68° の側弯とT6-10:91°の後弯を認め,右第7 肋骨頭の脊柱管内脱臼がみられた.本病態の報告例は少ないが,決して希な病態ではなくdystrophic change を伴う脊柱変形においては,肋骨頭の脊柱管内脱臼による潜在的リスクに注意する必要があると考える.Spinal deformities are common features in neurofibromatosistype-1( NF-1). Several types of deformities have been reported, however, intraspinal rib head dislocation (IRD)due to dystrophic change is very rare and not well understood. Between April 2006 and March 2010, we experienced3 patients with IRD out of 10 consecutive patients who underwent surgical treatment for dystrophic spinal deformities in NF-1. Case 1:A 6-year-old boy who had 74 ° short angular scoliosis at T4-8 and 72 ° at T8-11 underwent surgery in our institute. CT myelography demonstrated dystrophic changes with for aminal enlargement, vertebral body scalloping, rib penciling and mild IRD. He underwent the Growing Rod techniques and finally underwent posterior spinal fusion (PSF) from T1 to L2 combined with prophylactic rib head resection followed by anterior spinal fusion(ASF) with autologous fibular strut graft. No neurological complications were observed postoperatively and complete bony fusions were achieved. Case 2:Neurologically intact11-year-old boy presented with spinal deformity and caf&eacute;au-lait spots. Radiography showed 100 ° scoliosis at T3-7and 72 ° at T3-9. CT myelography demonstrated dystrophic changes and IRD and impingement of spinal cord. He underwent PSF with removal of the T6 rib head followed by ASF. Case 3:A 27-year-old woman presented with back pain and spinal deformities. Radiography showed 73 °scoliosis at T6-9 and 91 ° at T9-12. CT myelography demonstrated dystrophic changes and IRD. She also underwentPSF with removal of T7 rib head followed by ASF. AllIRDs were observed at the apex of the convex side of scoliosis.It has a potential risk of spinal cord compression and may cause paraplegia or paraparesis. Therefore, high degree of suspicion is warranted for the treatments of scoliosis with intraspinal rib displacement in NF-1

    Pairwise classification using quantum support vector machine with Kronecker kernel

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    We investigated the potential application of quantum computing using the Kronecker kernel to pairwise classification and have devised a way to apply the Harrow-Hassidim-Lloyd (HHL)-based quantum support vector machine algorithm. Pairwise classification can be used to predict relationships among data and is used for problems such as link prediction and chemical interaction prediction. However, in pairwise classification using a Kronecker kernel, it is very costly to calculate the Kronecker product of the kernel matrices when there is a large amount of data. We found that the Kronecker product of kernel matrices can be represented more efficiently in time and space in quantum computing than that in classical computing. We also found that a pairwise classifier can be effectively trained by applying the HHL-based quantum support vector machine algorithm to the Kronecker kernel matrix. In an experiment comparing a classical algorithm with a quantum support vector machine with a Kronecker kernel run on a quantum computing simulator, the misclassification rate of the latter was almost the same as that of the former for the same pairwise classification problem in some cases. This indicates that a quantum support vector machine with a Kronecker kernel algorithm can achieve accuracy equivalent to that of the classical algorithm more efficiently and scalably. This finding paves the way for applying quantum machine learning to predicting relationships in large-scale data

    Effect of particle size and structure on harmonic intensity of blood-pooling multi-core magnetic nanoparticles for magnetic particle imaging

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    Magnetic particle imaging has been developed by the optimization of the tracer materials, excitation systems, and system functions for image reconstruction. Here, we prepared and studied magnetic nanoparticles with different core diameters, coated by carboxymethyl-diethylaminoethyl dextran as a blood-pooling agent. For comparison, measurements were also performed using Resovist®, a widely used tracer agent. Transmission electron microscopy analysis of the prepared samples of nanoparticles revealed monodisperse single-core, chainlike aggregation, and multi-core structures. For optimizing the core size and structure of magnetic nanoparticles for use as imaging tracers, we evaluated the magnetization response to an applied field and harmonic intensity by measuring direct and alternating current hysteresis loops. To evaluate the dependence of the harmonic intensity on the core size and particle structures, large-magnetization particles were assembled using magnetic separation. The harmonic intensity depended not only on the core size but also on the particle structure. Diameters and distributions of single- and multi-core particles are important parameters. Solid and liquid samples of particles were studied for characterization of imaging of solid objects (such as tumors and organs) and liquids (such as blood)
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