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Search Results: 1 - 10 of 3544 matches for " Hiroyuki Okada "
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Assessment of the effectiveness of standardized infusion devices for healthcare management  [PDF]
Shio Sugita, Hideko Aida, Aya Okada, Hiroyuki Kobayashi
Health (Health) , 2011, DOI: 10.4236/health.2011.32017
Abstract: Since standardization is an important safety measure in healthcare systems, it is essential to systematically assess the effects of introducing new and increasingly complex medical equip-ment, such as infusion devices. In this study, we compared the effects of standardized polyvinyl chloride (PVC)-free closed-system integrated infusion devices with conventional infusion de-vices. Specifically, we assessed the safety, work efficiency, user-friendliness, and cost effec-tiveness of these devices. Compared with con-ventional infusion devices, integrated PVC-free infusion devices were more expensive to pur-chase and dispose, but were safer and more user-friendly and efficient. Although it would be preferable to use standardized infusion devices in all hospital departments, their cost may limit their application to departments that use high-risk treatments, where they would be most beneficial.
Investigation of Infrasound Radiated from Highway Bridge Owing to Moving Truck  [PDF]
Saiji Fukada, Hiroyuki Okada, Hirokazu Hama, Takeshi Mitsuda
Journal of Environmental Protection (JEP) , 2013, DOI: 10.4236/jep.2013.412155

Several complaints arose from houses near an object bridge about rattling sounds caused by infrasound, a low-frequency noise in the 0 - 20 Hz frequency range. In Japan, conventional trucks with a rear leaf suspension have vibration frequencies of about 3.0 Hz; furthermore, their tire spring vibration frequency is 10 - 20 Hz. Infrasound is radiated from the bridge owing to the truck’s suspension spring vibration and/or tire spring vibration. In this study, the bridge vibrations were investigated using test trucks or conventional trucks to determine the cause of rattling sounds. It was found that the truck’s spring vibration caused excessive bending vibration in the object bridge; this in turn was transmitted to nearby houses as infrasound. Various preventive measures for infrasound were then considered, and their effectiveness was investigated through a simulation of the dynamic response using a running truck. The difference between each measure’s effectiveness as obtained by a comparison with each simulation’s result provided a clear picture about the infrasound reduction methods in consideration of both construction cost and working difficulty.

Measurement of shear wave velocities coupled with an evaluation of elasticity using ARFI elastography in diagnosis of papillary thyroid carcinoma  [PDF]
Ryuhei Okada, Masami Suzuki, Koji Takeuchi, Hiroyuki Horikoshi, Atsunobu Tsunoda
Open Journal of Clinical Diagnostics (OJCD) , 2013, DOI: 10.4236/ojcd.2013.34033
Abstract: This study aimed to evaluate the diagnostic value of measuring the shear wave velocities (Vs) of thyroid nodules in diagnosis of the thyroid carcinoma. Using Virtual Touch Tissue Quantification (VTTQ) of acoustic radiation force impulse (ARFI) elastography (ACUSON S2000®, Siemens Medical Solutions, Mountain View, CA, USA), we measured the Vs of thyroid nodules in 39 nodules from 34 patients (four males and 30 females) before surgery. Elasticity itself was also estimated by VTTI (Virtual Touch Tissue Imaging) using ARFI. The average Vs of normal thyroid tissue was 2.24 ± 0.68 m/s. Twenty-three out of 39 nodules showed an average 2.52 ± 1.33 m/s. However, 16 other nodules showed “X.XX m/s”. These 16 nodules showed either “black” or “honeycomb” patterns of elasticity in VTTI. This value suggested that the Vs of these nodules were too fast or heterogenous to measure by this device. After the surgery, the pathologies of these nodules were revealed to be papillary carcinoma (21 cases), adenomatous goiter (11), follicular carcinoma (4), follicular adenoma (2) and follicular lymphoma (1). Five papillary carcinomas were found within adenomatous goiters. Nodules from four follicular carcinomas showed average Vs of 1.92 ± 0.48 m/s, while two follicular adenomas and follicular lymphoma showed 2.19 ± 0.06 and 2.34 m/s respectively. Nodules of adenomatous goiter showed 2.14 ± 0.60 m/s. On the other hand, nodules from five out of 21 papillary carcinomas showed average Vs of 4.00 ± 2.37 m/s. In the nodules of 16 papillary carcinomas, Vs were measured as “X.XX m/s” and this value was only observed in nodules of papillary carcinoma. These data reflected high and/or heterogenous elasticity of papillary carcinoma, in other words, the tissue of papillary carcinoma was hard and/or heterogenous. It was notable that the Vs value of “X.XX m/s” strongly suggested papillary carcinoma.
Effects of Long-lived 10 MeV Scale Sterile Neutrino on Primordial Elemental Abundances and Effective Neutrino Number
Hiroyuki Ishida,Motohiko Kusakabe,Hiroshi Okada
Physics , 2014, DOI: 10.1103/PhysRevD.90.083519
Abstract: The primordial lithium abundance inferred from observations of metal-poor stars is ~3 times smaller than the theoretical value in standard big bang nucleosynthesis (BBN) model. We assume a simple model including a sterile neutrino nu_H with mass of O(10) MeV which decays long after BBN. We then investigate cosmological effects of a sterile neutrino decay. We formulate the injection spectrum of nonthermal photons induced by electrons and positrons generated at the nu_H decay, as a function of the nu_H mass and the photon temperature. We then consistently solve (1) the cosmic thermal history, (2) nonthermal nucleosynthesis induced by the nonthermal photons, (3) the baryon-to-photon ratio eta, and (4) the effective neutrino number N_eff. Amounts of energy injection at the nu_H decay are constrained from limits on primordial D and 7Li abundances, the N_eff value, and the cosmic microwave background energy spectrum. We find that 7Be is photodisintegrated and the Li problem is partially solved for the lifetime 10^4-10^5 s and the mass >~ 14 MeV. 7Be destruction by more than a factor of 3 is not possible because of an associated D over-destruction. In the parameter region, the eta value is decreased slightly, while the N_eff value is increased by a factor of <~ 1. In this study, errors in photodisintegration cross sections of 7Be(g, a)3He and 7Li(g, a)3H that have propagated through literatures are corrected. It is then found that the new photodisintegration rates are 2.3 to 2.5 times smaller than the old rates, so that efficiencies of 7Be and 7Li photodisintegration are significantly smaller.
Constraints on f(R) theory and Galileons from the latest data of galaxy redshift surveys
Hiroyuki Okada,Tomonori Totani,Shinji Tsujikawa
Physics , 2012, DOI: 10.1103/PhysRevD.87.103002
Abstract: The growth rate of matter density perturbations has been measured from redshift-space distortion (RSD) in the galaxy power spectrum. We constrain the model parameter space for representative modified gravity models to explain the dark energy problem, by using the recent data of f_m(z)sigma_8(z) at the redshifts z = 0.06--0.8 measured by WiggleZ, SDSS LRG, BOSS, and 6dFGRS. We first test the Hu-Sawicki's f(R) dark energy model, and find that only the parameter region close to the standard Lambda Cold Dark Matter (Lambda-CDM) model is allowed (lambda > 12 and 5 for n = 1.5 and 2, respectively, at 95% CL). We then investigate the covariant Galileon model and show that the parameter space consistent with the background expansion history is excluded by the RSD data at more than 10 sigma because of the too large growth rate predicted by the theory. Finally, we consider the extended Galileon scenario, and we find that, in contrast to the covariant Galileon, there is a model parameter space for a tracker solution that is consistent with the RSD data within a 2 sigma level.
A Pfaffian-Hafnian analogue of Borchardt's identity
Masao Ishikawa,Hiroyuki Kawamuko,Soichi Okada
Mathematics , 2004,
Abstract: We present an identity which can be regarded as a Pfaffian-Hafnian analogue of Borchardt's identity and as a generalization of Schur's identity. We give a proof using the complex analysis.
Disparity in clinical care for patients with inflammatory bowel disease between specialists and non-specialists  [PDF]
Tomoko Hirakawa, Jun Kato, Sakuma Takahashi, Hideyuki Suzuki, Mitsuhiro Akita, Izumi Inoue, Hisanobu Deguchi, Sakiko Hiraoka, Hiroyuki Okada, Kazuhide Yamamoto
Open Journal of Gastroenterology (OJGas) , 2013, DOI: 10.4236/ojgas.2013.31010

Background: Although inflammatory bowel disease (IBD) patients have been increasing and new thera-peutic options for IBD have been developed, there are relatively few clinicians who specialize in IBD. Patients treated by a non-specialist of IBD may not receive appropriate treatment. This study aimed to compare disease and medication status between IBD patients treated by a specialist and those treated by a non-specialist. Methods: Medical charts of ambulating IBD patients in two hospitals were examined. All patients in one hospital were treated by one of the IBD specialists, while in the other hospital, patients were treated by one of the gastroenterologists who was a non-specialist of IBD. Results: The numbers of IBD patients were 255 (hospital with specialists) and 74 (hospital without specialists), respectively. Disease activity of the patients was not well-controlled in the hospital without specialists compared to in the hospi- tal with specialists (ulcerative colitis (UC): p = 0.0006 and Crohn’s disease: p = 0.012, respectively). The proportion of UC patients who received an insufficient dose of mesalazine (Pentasa < 3 g/day or Asacol < 3.6 g/day) was higher in the hospital without specialists (47% vs. 15%, p < 0.0001). In the hospital without specialists, more patients received long-term corticosteroids (UC: 23% vs. 5%, p < 0.0001), while fewer patients received immunomodulators (UC: 8% vs. 46%, p < 0.0001). Conclusions: IBD patients of the hospital without specialists were not well-controlled and were not prescribed appropriately with thera-peutic drugs. Fostering and placement of the specialist of IBD is an urgent problem.

Cementoblastoma Arising in the Maxilla of an 8-Year-Old Boy: A Case Report
Hiroyuki Harada,Ken Omura,Seiki Mogi,Norihiko Okada
International Journal of Dentistry , 2011, DOI: 10.1155/2011/384578
Abstract: Cementoblastoma is an uncommon disease, representing only 1–8% of all odontogenic tumours. Furthermore, this tumour is especially uncommon in children, as only five cases have been reported in this age group. Here, we describe a case of cementoblastoma arising in the maxilla of an 8-year-old boy, that was treated with a partial maxillectomy. The patient's facial appearance has remained satisfactory, and the tumour has not recurred in the 9 years after the operation. 1. Introduction Cementoblastoma, characterized by the formation of hard cemental tissue contiguous with a dental root, is an uncommon mesenchymal neoplasm, representing 1% to 8% of all odontogenic tumours [1–3]. Reported cases include patients from 6 to 75 years old, with the highest incidence in the second decade. This tumour is especially uncommon in patients under 10 years old, and its occurrence in the maxilla is also rare [4]. To our knowledge, only five cases of cementoblastoma in patients under the age of 10 have been reported [5–9] (Table 1). In this paper, we describe a case of cementoblastoma arising in the maxilla of an 8-year-old boy who was followed up for the extended period of 9 years. Table 1: Clinical data for five cementoblastoma patients under age 10. 2. Case Report The patient was an 8-year-old boy. He was referred to our department on August 24, 2001 for evaluation of a hard mass in the right maxilla. He had noticed the asymptomatic mass 3 months before. The patient had no significant past medical history. Oral examination revealed a firm, painless mass located on the posterior hard palate, contiguous with the maxillary first molar (Figure 1). The lesion measured 3.0?cm × 2.5?cm and extended over the midline of the hard palate. The overlying mucosa showed slight redness, and the first and second premolars were displaced toward the buccal side. However, extensive mobility of the premolar and molar teeth or effect on tooth vitality determined by the electric pulp test was not observed. The patient had no nasal obstruction or difficulty with speech or chewing. A computed tomography (CT) scan showed a 2.9?cm × 2.7?cm × 2.6?cm well-circumscribed mass involving the roots of the right maxillary first molar (Figure 2(a)). The tumour consisted of low-density cemental regions that penetrated into the nasal cavity and maxillary sinus (Figure 2(b)). Bone scintigraphy showed an intense uptake in the right maxilla. The lesion was clinically diagnosed as a cementoblastoma or osteoblastoma. However, approval for immediate treatment could not be obtained by the patient and his parents.
Intranasal Delivery of Camptothecin-Loaded Tat-Modified Nanomicells for Treatment of Intracranial Brain Tumors
Hiroyuki Taki,Takanori Kanazawa,Fuminari Akiyama,Yuuki Takashima,Hiroaki Okada
Pharmaceuticals , 2012, DOI: 10.3390/ph5101092
Abstract: The blood-brain barrier is a substantial obstacle for delivering anticancer agents to brain tumors, and new strategies for bypassing it are sorely needed for brain tumor therapy. Intranasal delivery provides a practical, noninvasive method for delivering therapeutic agents to the brain. Intranasal application of nano-sized micelles that have been modified with Tat peptide facilitates brain delivery of fluorescent model materials. In this study, we evaluated a nose-to-brain delivery system for brain tumor therapy. We nasally administered the anti-tumor drug camptothecin (CPT) in solution and in methoxy poly(ethylene glycol) (MPEG)/poly(e-caprolactone) (PCL) amphiphilic block copolymers (MPEG-PCL) and cell penetrating peptide, Tat analog-modified MPEG-PCL (MPEG-PCL-Tat) MPEG-PCL-Tat to rats bearing intracranial glioma tumors and quantified the cytotoxicity against glioma cells, and the therapeutic effects. CPT-loaded MPEG-PCL-Tat micelles showed higher cytotoxicity than CPT-loaded MPEG-PCL. CPT-free MPEG-PCL-Tat didn’t show any cytotoxicity, even at high concentrations (2 mmol/mL). CPT-loaded MPEG-PCL-Tat micelles significantly prolonged the median survival of rats. These results indicate that intranasal delivery of anti-cancer drugs with cell penetrating peptide-modified nanomicelles might be an effective therapy for brain tumors.
Activation and detection of HTLV-I Tax-specific CTLs by Epitope expressing Single-Chain Trimers of MHC Class I in a rat model
Takashi Ohashi, Mika Nagai, Hiroyuki Okada, Ryo Takayanagi, Hisatoshi Shida
Retrovirology , 2008, DOI: 10.1186/1742-4690-5-90
Abstract: We have established expression vectors which encode SCTs of rat MHC-I (RT1.Al) with Tax180-188 peptide. Human cell lines transfected with the established expression vectors were able to induce IFN-γ and TNF-α production by a Tax180-188-specific CTL line, 4O1/C8. We have further fused the C-terminus of SCTs to EGFP and established cells expressing SCT-EGFP fusion protein on the surface. By co-cultivating the cells with 4O1/C8, we have confirmed that the epitope-specific CTLs acquired SCT-EGFP fusion proteins and that these EGFP-possessed CTLs were detectable by flow cytometric analysis.We have generated a SCT of rat MHC-I linked to Tax epitope peptide, which can be applicable for the induction of Tax-specific CTLs in rat model systems of HTLV-I infection. We have also established a detection system of Tax-specific CTLs by using cells expressing SCTs fused with EGFP. These systems will be useful tools in understanding the role of HTLV-I specific CTLs in HTLV-I pathogenesis.Human T-cell leukemia virus type I (HTLV-I) is etiologically linked to adult T-cell leukemia (ATL) [1,2], a chronic progressive neurological disorder termed HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) [3,4], and various other human diseases [5-8]. ATL is a malignant lymphoproliferative disease affecting a subgroup of middle-aged HTLV-I carriers characterized by the presence of mature T cell phenotype [9]. HTLV-I genome contains a unique 3' region, designated as pX, which encodes the viral transactivator protein, Tax [10]. Because of its broad transactivation capabilities [11], it is speculated that Tax plays a central role in HTLV-I associated immortalization and transformation of T cells, which may lead to the development of ATL.Tax is also known as a major target protein recognized by cytotoxic T lymphocytes (CTL) of HTLV-I carriers [12]. It has been reported that the levels of HTLV-I-specific CTL are quite diverse among HTLV-I carriers and that ATL patients have impaired l
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