69 research outputs found

    Microwave analog of Stern-Gerlach effects using nonuniform chiral metamaterials

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    This study observes microwave beam splitting dependent on circular polarizations through nonuniform chiral metamaterials. Nonuniform chiral metamaterials with a gradation in refractive index are constructed using chiral meta-atoms that exhibit optical activities at microwave frequencies. Microwave scattering far-field patterns by the nonuniform chiral metamaterials demonstrate a deflection of microwaves, which transmit in a direction perpendicular to the refractive index gradient. Furthermore, circularly polarized microwaves with opposite “spins of light” go their separate ways in the nonuniform chiral metamaterials. This phenomenon is an optical analog of the Stern-Gerlach effects for electrons

    Effects of astaxanthin on accommodation, critical flicker fusion, and pattern visual evoked potential in visual display terminal workers

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    We evaluated the effects of astaxanthin, a red carotenoid, on accommodation, critical flicker fusion (CFF), and pattern visual evoked potential (PVEP) in visual display terminal (VDT) workers. As controls, 13 non-VDT workers received no supplementation (Group A). Twenty-six VDT workers were randomized into 2 groups: Group B consisted of 13 subjects who received oral astaxanthin, 5 mg/day, for 4 weeks, and Group C consisted of 13 subjects who received an oral placebo, 5 mg/day, for 4 weeks. No significant difference in age was noted among the 3 groups. A double-masked study was designed in Groups B and C. Accommodation amplitude in Group A was 3.7± 1.5 diopters. Accommodation amplitudes (2.3±1.4 and 2.2±1.0 diopters) in Groups B and C before supplementation were significantly (p<0.05) lower than in Group A. Accommodation amplitude (2.8±1.6 diopters) in Group B after astaxanthin treatment was significantly (p<0.01) larger than before supplementation, while accommodation amplitude (2.3±1.1 diopters) in Group C after placebo supplementation was unchanged. The CFFs and amplitude and latency of P100 in PVEP in Group A were 45.0±4.2 Hz, 6.5±1.8μV, and 101.3±6.5 msec, respectively. The CFFs in Groups B and C before supplementation were significantly (p<0.05) lower than in Group A. The CCFs in Groups B and C did not change after supplementation. Amplitudes and latencies of P100 in PVEP in Groups B and C before supplementation were similar to those in Group A and did not change after supplementation. Findings of the present study indicated that accommodation amplitude improved after astaxanthin supplementation in VDT workers. 赤色カロチノイドの一種であるアスタキサンチンのvisual display terminal(VDT)作業者の調節力,中心フリッカー値,パターン視覚誘発電位に及ぼす影響を調べた。VDT作業を行わない13人をコントロールとした(Group A)。26人のVDT作業者を2群に無作為に分けた。Group Bはアスタキサンチン一日5mg 4週間内服した13人で,Group Cはアスタキサンチンを含有しないカプセルを4週間内服した13人とした。外見上同じカプセルでの内服投与を行った。結果:Group AはGroup B及びGroup Cと比較して,調節力,中心フリッカー値は有意に高い値であったが,パターン視覚誘発電位検査結果は,Group B,Cと有意差はなかった。Group Bでは,アスタキサンチンの投与前後で有意な調節力の改善がみられた(p<0.01)。しかし,中心フリッカー値,パターン視覚誘発電位に変化はみられなかった。Group Cでは,投与前後で,調節力,中心フリッカー値,パターン視覚誘発電位に変化はみられなかった。考察:VDT作業者では,非作業者と比べ調節力,中心フリッカー値が低下していることは以前より報告されており,今回の我々の研究でも同様の結果であった。VDT作業者で,アスタキサンチン非内服群では,調節力は投与前後で変化がなかったが,アスタキサンチンの内服群で,有意に調節力が改善した。VDT作業者の調節力の改善には,アスタキサンチンの内服が有効と考えられた

    Curved-Tip Disposable Injector (OUReP Injector) to Insert Photoelectric Dye-Coupled Polyethylene Film (OUReP) as Retinal Prosthesis into Subretinal Space of Rabbit Eyes

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    The photoelectric dye-coupled thin polyethylene film functions as a novel type of retinal prosthesis in subretinal space of the eye. We previously reported a novel disposable injector to insert the thin film into subretinal space of the rabbit eye by vitreous surgery. The injection system composed of two separate parts, injector and loader. A circular film in 5 mm to 10 mm diameter was pulled into a transparent tube of the loader with a commercial 25-gauge forceps. The loader tube was joined with a sleeve to tube tip of the injector. The film in the loader was pushed with a plunger for the loader into the injector tube tip. The loader with the sleeve was removed from the injector tip, and the tube tip with the film was filled with solution. This study reported a small-bore curved-tip disposable injector with outer diameter of 1.6 mm. A curved-tip polypropylene tube was formed by the process of heating and cooling of the tube inserted with a curved guide wire. The plunger for the curved-tip tube was made of a polyphenylsulfone tip connected with a press-fitting inner polypropylene tube to a nylon rod. Bleb retinal detachment in 4 surgically aphakic eyes of rabbits were induced by infusing solution into subretinal space with a 38-gauge polyimide tip, and a retinal tear was made at the edge of retinal detachment with 25-gauge diathermy. The injector tip with the rolled film in 6 mm diameter was inserted from 2 mm wide scleral incision into vitreous and then into subretinal space. The rolled films were released into subretinal space with the tip end inserted into the retinal tear, and the released films were confirmed to stay under the retina with no additional aid. Dissection one month after surgeries confirmed successful implantation of 4 films into subretinal space of each rabbit eye. The curved-tip injector could release the rolled film into the subretinal space without additional effort, compared with the straight-tip injector, and would help surgeons implant photoelectric dye-coupled thin film retinal prosthesis easily at vitreous surgery

    Pharmacological preconditioning in type 2 diabetic rat hearts: the roles of mitochondrial ATP-sensitive potassium channels and the phosphatidylinositol 3-kinase-Akt pathway.

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    PURPOSE: The authors examined whether olprinone, a phosphodiesterase type 3 inhibitor, or isoflurane, a volatile anesthetic, could protect the heart against myocardial infarction in type 2 diabetic rats and whether the underlying mechanisms involve protein kinase C (PKC), mitochondrial ATP-sensitive potassium (m-K(ATP)) channels, or the phosphatidylinositol 3-kinase (PI3K)-Akt pathway. METHODS: All rats underwent 30 min of coronary artery occlusion followed by 2 h of reperfusion. Wistar rats received isoflurane or olprinone before ischemia with or without the PKC inhibitor chelerythrine (CHE), the m-K(ATP) channel blocker 5-hydroxydecanoic acid (5HD), or the PI3K-Akt inhibitor LY294002 (LY). Goto-Kakizaki (GK) rats were randomly assigned to receive isoflurane or olprinone. In another group, GK rats received LY before the olprinone. RESULTS: In the Wistar rats, both isoflurane (38 +/- 11%) and olprinone (40 +/- 11%) reduced infarct size as compared to the control group (59 +/- 8%). In the GK rats, olprinone (41 +/- 9%) but not isoflurane (53 +/- 11%) reduced infarct size as compared to the GK control group (58 +/- 14%). The beneficial effects of olprinone were blocked by LY (58 +/- 14%). In the Wistar rats, CHE, 5HD, and LY prevented isoflurane-induced reductions of infarct size. On the other hand, LY but not CHE or 5HD prevented olprinone-induced reductions of infarct size. CONCLUSIONS: Olprinone but not isoflurane protects the heart against myocardial infarction in type 2 diabetic rats. The olprinone-induced cardioprotective effect is mediated by the PI3K-Akt pathway but not PKC or m-K(ATP) channels

    Clinical impact of the loss of chromosome 7q on outcomes of patients with myelodysplastic syndromes treated with allogeneic hematopoietic stem cell transplantation

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    We conducted a nationwide retrospective study to evaluate the prognostic influence of +1, der(1;7)(q10;p10) [hereafter der(1;7)] and ?7/del(7q) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for de novo myelodysplastic syndromes (MDS). In this database, 69 MDS patients with der(1;7), 75 with ?7/del(7q), and 511 with normal karyotype (NK) underwent allo-HSCT at advanced disease status. The 3-year overall survival (OS) and cumulative incidence of relapse (CIR) were 50.4 and 19.4% for those with der(1;7), 36.2 and 38.4% for ?7/del(7q),and 51.1 and 20.7% for NK, respectively. In the multivariate analysis, the presence of ?7/del(7q) correlated with a significantly shorter OS (HR [95% CI], 1.38 [1.00?1.89]; P = 0.048) and higher CIR (HR, 2.11 [1.36?3.28]; P = 0.001) than those with NK. There were 23 patients with der(1;7), 29 with ?7/del(7q), and 347 with NK who underwent allo-HSCT at early disease status.The 3-year OS and CIR were as follows: 47.3 and 9.5% for the der(1;7) group, 70.5 and 13.8% for ?7/del(7q), and 70.9 and 5.6% for NK,respectively. No significant differences were observed in OS and CIR among three groups. The impact of the loss of chromosome 7q on OS and CIR may differ based on its type and disease status after allo-HSCT for MDS

    Measurement of Indoor Thoron Gas Concentrations Using a Radon-Thoron Discriminative Passive Type Monitor: Nationwide Survey in Japan

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    As part of a nationwide survey of thoron (220Rn) in Japan, the indoor 220Rn gas concentrations in 940 dwellings were measured throughout one year, from 1993 to 1996, using a passive type 222Rn-220Rn discriminative monitor. The monitor was placed in a bedroom or a living room in each house for four successive three-month periods. The mean annual indoor 220Rn concentration was estimated from the four measurements in each house. The arithmetic mean, the median and the geometric mean for indoor 220Rn concentrations in 899 dwellings were 20.1, 9.6 and 10.0 Bq m−3, respectively. The 220Rn concentrations exhibited a log-normal distribution. It was found that the 220Rn concentrations were dependent on the nature of the materials used for wall construction and also on the distance of measurement from the wall. Significant seasonal variations in the 220Rn concentration were not observed. It would seem that the nature of the wall material contributed to the increased indoor 220Rn concentrations

    Japanese population dose from natural radiation

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    The radiation doses from natural radiation sources in Japan are reviewed using the latest knowledge. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the Nuclear Safety Research Association report the annual effective doses from cosmic rays, terrestrial radiation, inhalation, and ingestion as natural sources. In this paper, the total annual effective dose from cosmic-ray exposure is evaluated as 0.29 mSv. The arithmetic mean of the annual effective dose from external exposure to terrestrial radiation is 0.33 mSv for the Japanese population using the data of nationwide surveys by the National Institute of Radiological Sciences. Previously in Japan, although three different groups have conducted nationwide indoor radon surveys using passive-type radon monitors, to date only the Japan Chemical Analysis Center (JCAC) has performed a nationwide radon survey using a unified method for radon measurements conducted indoor, outdoor, and in the workplace. Consequently, the JCAC results are used for the annual effective dose from radon and that for radon inhalation is estimated as 0.50 mSv using a current dose conversion factor. In this paper, UNSCEAR values are used for the mean indoor and outdoor thoron-progeny concentrations, and the annual effective dose from thoron is reported as 0.09 mSv. Thus, the annual effective dose from radon and thoron inhalation is 0.59 mSv. From a JCAC large-scale survey of foodstuffs, the committed effective dose from the main radionuclides in dietary intake is 0.99 mSv. Finally, the Japanese population dose from natural radiation is given as 2.2 mSv, which is similar to the reported global average of 2.4 mSv
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