764 research outputs found

    Petrology of the Yamato-8449 CR chondrite

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    The Yamato (Y)-8449 chondrite is a new CR (Renazzo-type) chondrite, and the constituent minerals coincide in chemical composition with those of the other CR chondrites except phyllosilicate and metal. FeO and Al_2O_3 contents of phyllosilicates in Y-8449 are richer than those in other CR chondrites. Fe-Ni metal in Y-8449 is classified into two types; one type has an exsolution texture indicating a slow cooling rate of the metal, and the other type has a massive texture free from exsolution texture. Massive Fe-Ni metal in Y-8449 is more homogeneous than that in the other CR chondrites. Groundmass glass and phenocrystic enstatite in Y-8449 chondrules have been replaced by phyllosilicate in the chondrule rims, and the aqueous alteration reaction that produced the phyllosilicate had possibly taken place in a nebula at low temperatures prior to accretion onto the parent body

    中国淮河流域付近の入梅前の時期における大気場や陸面状態の季節進行 (1998年の事例解析)

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     Seasonal evolution of atmospheric and land surface conditions around the Huaihe River Basin in China in the pre-Meiyu stage of 1998 were examined, mainly based on the GAME re-analysis data. Around the Huaihe River Basin in China (just to the nront of the Changjiang River Basin), although the air temperature increased rapidly already in early June (the Meuyu front was located to the south of that region), the specific humidity did not increas so much at time. In addition, the latent heat supplied from the ground there decreased from late May to early June, compared to that before early May. The time mean southerly wind component across the low-level baroclinic Zone (although not so strong as in the mature stage of the Meiyu) invaded into Central Cjina during late April to early May. On the other hand, the relatively strong wind region once retreated southward in the middle of May associated with the onset of the Southeast Asian monsoon, and the calm wind region with frequent appearance of the surface high was seen around the Huaihe River Basin from late May to early June. Thus the present study shows that the Huaihe River Basin once experiences the rather drier stage just before the onset stage of the mature Meiyu there

    The cerebral basis for language learner strategies: A near-infrared spectroscopy study

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    In this paper, we validate Macaro’s (2006) model of strategy use among language learners by assessing the amount of neural activity around the prefrontal cortex, the supposed locus of working memory (WM). We also examine whether WM activation during first language (L1) strategy deployment is lower than WM activation during second language (L2) strategy deployment, as predicted by Macaro’s model. In the analysis, we consider data obtained through an innovative neuroimaging technique (near-infrared spectroscopy) and stimulated- recall interviews. The results reveal greater brain activity during execution of the L1 and L2 tasks than in a control condition; further, use of strategies in the L2 resulted in stronger WM activation than use of strategies in the L1. These results provide partial support for the validity of Macaro’s model

    Anaphylaxis after jellyfish ingestion with no history of stings: a pediatric case report

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    Background Jellyfish stings are known to induce allergic skin reactions; however, case reports of anaphylaxis after jellyfish ingestion have been increasing, especially in Asian countries. Some cases of anaphylaxis after jellyfish ingestion have been reported in patients with a previous history of frequent jellyfish stings. Herein, we report a pediatric patient with anaphylaxis after jellyfish ingestion with no history of jellyfish stings. Case presentation A 14-year-old girl developed two episodes of anaphylaxis, and her diet diaries revealed that edible jellyfish was common to the meals in both the anaphylaxis events. A skin prick test using five types of edible jellyfish products revealed a positive reaction to some jellyfish, and anaphylaxis was observed after the ingestion of jellyfish in an oral food challenge test. She had no history of jellyfish stings or frequent swimming in the ocean. The basophil activation test showed positive results on stimulation with extracts from various types of edible jellyfish. We observed serum immunoglobulin E (IgE) reactivity to purified jellyfish collagen and jellyfish acid-soluble extracts. Moreover, immunoblotting analysis showed IgE reactivity to two bands at approximately 40 and 70 kDa using purified jellyfish collagen, which may be a causative antigen. Conclusions Edible salted jellyfish can be one of the causative foods of anaphylaxis. Clinicians should be aware of the possibility of anaphylactic reactions due to jellyfish ingestion even without a history of jellyfish stings

    Internal carotid artery dissection at the supraclinoid portion after severe traumatic head injury in a child

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    A 14-year-old boy with severe traumatic brain injury (TBI) and cranial fractures was admitted to our emergency department after a motor vehicle accident. An emergency craniotomy was performed, and traumatic carotid artery (CA) dissection (tCAD) was revealed by cerebral angiography. The patient then underwent close observation in the intensive care unit. Traumatic CADs are difficult to diagnose in the early period after injury, and are associated with serious problems and a high mortality rate. There is still a lack of knowledge surrounding its natural history and treatment options, especially in children. Moreover, it commonly occurs at the cervical internal CA, and tCAD at the supraclinoid portion is quite rare. To the best of our knowledge, this is the first report accompanied by radiological images of the clinical course of tCAD at the supraclinoid portion following severe TBI in a child

    金属ポルフィリンを電極触媒とする酸素還元反応に対する磁場効果

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    金沢大学教養部電気化学反応における磁場効果として,これまで不斉収率の向上や電解質のMHDフロ-による反応経路および拡散限界電流への影響などが報告されている。しかしながら,電極反応に直接関与する反応物や触媒の磁気的性質には殆んど注目されていない。そこで,本研究では電極触媒としての金属ポルフィリンの磁気的性質が磁場中での酸素還元にどのような影響を及ぼすかについて検討した。金属ポルフィリンには,水不溶性のメソ-テトラフェニルポルフィリン(TPP)並びに水溶性のメソ-テトラキス(4ースルホナトフェニル)ポルフィリン(TPPS)およびメソ-テトラキス(1ーメチルピリジニウムー4ーイル)ポルフィリン(TMPyP)のCo(III),Mn(III),Fe(III)錯体を使用した。1.水不溶性金属ポルフィリン(TPPーM)における磁場効果磁場効果は金属ポルフィリン被覆グラッシ-カ-ボン電極を使用して検討した。すなわち,酸素飽和0.1MNaOH中でのサイクリックボルタモグラムを磁場がある時とない時とで測定した。金属ポルフィリンの磁気的性質(磁化率)は異っているにもかかわらず,サイクリックボルタモグラムに殆んど差がなく顕著な磁場効果は認められなかった。2.水溶性金属ポルフィリン(TPPSーM.及びTMpyPーM)における磁場効果磁場効果は0.2×10^Mの金属ポルフィリンを含む酸素飽和0.1MNaOH,グラッシ-カ-ボン電極でのサイクリックボルタモグラムを磁場効果がある時とない時とで測定した。この場合,金属ポルフィリンの磁化率に依存した明確な磁場効果が認められた。即ち,電極触媒として電極反応に関与する水溶性金属ポルフィリンの磁化率の増加と共に酸素還元の拡散限界電流は増加した。この結果は,酸素の拡散が金属ポルフィリンのMHDフロ-によって効果的に促進される事,酸素還元が金属ポルフィリンの分子表面,恐らく金属サイト上で起る事を示唆している。Magnetic field effect in the electrochemical reactions has been reported to lead to the increase in asymmetric yield, and the MHD (magnetohydrodynamic) flow of electrolyte which affects the reaction pathway and the diffusion limiting current. However, much attention has not been given to the magnetic property of reactant and catalyst taking part in the electrode reaction directly. It was studied how the magnetic property of metalloporphyrin as the electrocatalyst affected the cathodic reduction of oxygen in the magnetic field. As the metalloporphyrin, Co(III), Mn(III), and Fe(III) complexes of (1) water-insoluble meso-tetraphenylporphyrin (TPP-M), and (2) water-soluble meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS-M) and meso-tetrakis (l-methylpyridinium-4-yl) porphyrin (TMpyP-M) were chosen in the present research. The different states in the electrolytic system were compared.(1) Magnetic field effect at water-insoluble metalloporphyrinsThe magnetic field effect was examined by the cyclic voltammetry, using a metalloporphyrin-coated glassy carbon electrode. The cyclic voltammograms in oxygen-saturated 0.1M NaOH with and without magnetic field were almost the same. The magnetic field (0.8 tesla) seems to have scarce effect on the activation of oxygen molecule at the immobilized metalloporphyrin.(2) Magnetic field effect at water-soluble metalloporphyrinsThe magnetic field effect was examined by the cyclic voltammetry in 0.1M NaOH dissolved metalloporphyrin, using a bare glassy carbon electrode. The cyclic voltammograms with and without magnetic field showed a difference, especially at the diffusion limiting current. The diffusion limiting current for oxygen reduction increased with increasing the magnetic susceptibility of dissolved metalloporphyrin, which take part in the electrode reaction as the catalyst. The results suggest that the diffusion of oxygen is effectively promoted by the MHD flow of metalloporphyrin, and the oxygen reduction occurs on the molecular surface of metalloporphyrin, probably on the metal site.研究課題/領域番号:63550600, 研究期間(年度):1988 – 1989出典:研究課題「金属ポルフィリンを電極触媒とする酸素還元反応に対する磁場効果」課題番号63550600(KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/ja/report/KAKENHI-PROJECT-63550600/635506001991kenkyu_seika_hokoku_gaiyo/)を加工して作

    多孔性ヒドロキシルアパタイト修飾電極による酵素の直接電気化学

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    金沢大学理学部ヒドロキシルアパタイト(HAP)を修飾した多孔性電極を用いて酵素(シトクロムc)の直接電気化学を検討し以下の成果を得た.(1) 極間電圧50Vでの電解還元析出により得たヒドロキシアパタイト(HAP)の等電点はpH=7.6で市販品(太平産業)の等電点,pH=7.5(球形HAP)〜pH=7.8(HAP200および300)とほぼ同じであった.(2) 上記市販のヒドロキシアパタイト(HAP)微粉末塗布電極において,基体電極としてPt,Au,GC(グラッシーカーボン)を選び,シトクロムcの直接電気化学を検討した.直接電気化学が可能であったのはGCのみで,基体電極とヒドロキシアパタイト微粒子との境界領域でシトクロムcの電極反応が進行すること,ならびにヒドロキシアパタイトが固体プロモータとして機能しうることが明らかとなった.(3) HAP微粉末塗布GC電極(塗布量35μg/cm2)の表面被覆率を中性の1,1\u27-フェロセンジメタノールを用いた電位ステップ法により測定した.被覆率は10〜20%,有効表面積は80〜90%であった.(4) 0.04Mリン酸二水素カルシウム水溶液中でのパルス電解(-9.5V(vs.Ag|AgCl)x20秒,0Vx20秒の繰り返し)によるヒドロキシアパタイトの析出挙動を購入した水晶振動子化学計測装置(Pt電極(表面積0.2cm^2))を用いて追跡した.析出量は電解時間に比例し,1200秒の電解で64.5μgの析出を確認した.(5) 定電圧電解(陰極GC,陽極Pt)で析出したHAPの微粉末塗布GC電極(塗布量35μg/cm^2)でのシトクロムcの直接電気化学では,還元ピーク電位と酸化ピーク電位との差(ΔEp)がHAPの結晶性の向上とともに低下し,50V電解析出物で可逆的電子移動を意味する65mVが得られた.研究課題/領域番号:09874140, 研究期間(年度):1997 – 1998出典:研究課題「多孔性ヒドロキシルアパタイト修飾電極による酵素の直接電気化学 」課題番号09874140(KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09874140/)を加工して作
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