この研究プロジェクトは 、欧州共同体の第7次フレームワーク計画（FP7/2007-2013）/ ERCの助成合意N°242710下欧州研究評議会から資金提供を受けており、さらにヒューマン·フロンティア·サイエンス·プログラムとドイツのエミーネーター·プログラムによってサポートされていました研究財団（SCHR 995/2-1）。

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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+magnetic+resonance+of+laser-polarized+noble+gases+in+molecules,+materials,+and+organisms.">Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials, and organisms.</a> J. Magn. Reson. 155, 157-216 (2002).</li><li>Nikolaou, P., Whiting, N., Eschmann, N. A., Chaffee, K. E., Goodson, B. M., Barlow, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+laser-polarized+xenon+using+fiber-coupled+laser-diode+arrays+narrowed+with+integrated+volume+holographic+gratings.">Generation of laser-polarized xenon using fiber-coupled laser-diode arrays narrowed with integrated volume holographic gratings.</a> J. Magn. Reson. 197, 249-254 (2009).</li><li>Ruppert, K., Brookeman, J. R., Hagspiel, K. D., Mugler, J. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetic+resonance+imaging+of+hyperpolarized+129Xe+produced+by+spin+exchange+with+diode-laser+pumped+Cs.">Magnetic resonance imaging of hyperpolarized 129Xe produced by spin exchange with diode-laser pumped Cs.</a> Appl. Phys. Lett. 73, 2666 (1998).</li><li>Zhou, X., Sun, X. P., Luo, J., Zeng, X. Z., Liu, M. L., Zhan, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+Hyperpolarized+129Xe+Gas+Without+Nitrogen+by+Optical+Pumping+at+133Cs+D2+Line+in+Flow+System.">Production of Hyperpolarized 129Xe Gas Without Nitrogen by Optical Pumping at 133Cs D2 Line in Flow System.</a> Chin. Phys. 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過分極キセノンの製造における重要な側面は、ポンプセルと円偏光を持つセルの十分な照明など、ガスマニホールド中の酸素不純物である。上記の電球テストはルビジウムの転送中に有害な酸素濃度を検出するための簡単​​な方法です。アルカリ金属は、セルを偏光子にインストールされた時点で、その光沢のある表面を失う可能性があります。 。一度、しかし、非酸化Rbの十分な気化を?...

彼らは、特定の状況下で2感度の問題を解決することができるので、過分極剤は、NMR / MRIのアプリケーションのために注目を集めている。すべてが前に実際分光やイメージング実験にNMRマグネット外人為的に増加したスピン集団間の差異を準備している3つの主要なアプローチは、現在（そして交換光ポンピング、ヒソプをスピン;、パラ水素誘起分極、PHIP動的核分極は、DNP）が使用されている。ここでは、溶液状態の実験で使用した超偏極129 Xeの製造用に最適化されてい燮セットアップの機能と動作について説明します。 必須成分は795 nmで赤外線光子を発する強烈な光源である。レーザダイオードアレイ（LDA）は、高出力、合理的なコストで&gt; 100 Wを提供する便利なデバイスです。多くのセットアップでは、LDAは多かれ少なかれ目の偏光を保持していることを光ファイバに放出している電子レーザー光。十分燮プロセスを保証するために、この楕円偏光は、高純度の円偏光に変換する必要があります。偏光光学系の主要な構成要素は、 図1および図2に示されており、システムのセットアップは補足ムービー1に模式的に説明されています。 円偏光を偏光させるために、我々は最初の電力密度を低減するための一次ビーム拡大光学素子（ 例えば 、ファイバコリメータ）にファイバ端を取り付けます。光は、直線偏光を発生させると、偏光ビームスプリッタキューブを通過します。このキューブを回転させることにより、我々は、パワー·メータと残留分極の好ましい軸を決定することができます。最大伝送は、キューブの速い軸は主光線の偏光軸と一致させている状況に対応しています。高い吸光係数を持つキューブ（10万：1以上）は、偏光成分の良好な分離が得られます。これは、テストすることができます最初のものは並外れたビームの最大伝送のために整列されている間回転させアナライザとして第2のビームスプリッタキューブを使用しています。 透過光の直線偏光が確認された後、795 nmのために設計され、λ/ 4波長板を円偏光に線形変換する超常光線に導入される。この目的のために、波長板の高速軸は45°ビームスプリッタキューブ速い軸に対してにより回転される。 （必要に応じて、その直線偏光軸に垂直と超常光線に対する反射普通の光の円偏光は、同様の方法で達成することができます。） 円偏光の質は回転時に一定の伝送が得られるはず第2のビームスプリッタキューブでテストすることができます。二次ビーム拡大光学系（ガリレイ望遠鏡の構成で例えば 2つのレンズが）その後、私は完全にビーム径を増大させるオーブンボックス内のポンピングプロセス用ガラスセルをlluminate。細胞におけるRb蒸気によるレーザ光 ​​の吸収がボックスの末尾にポンプセル背後にピンホールを介して監視されます。コリメータは、光分析装置（ポンピングセルのセットアップについては図3を参照して分析される減衰赤外線ビームを収集）。 ポンプセル外加熱機構が部分的にセルの中に座ったRb滴（ 図4a）を気化させ、したがって、レーザー光吸収を引き起こす。蒸気の密度はそれぞれのPIDコントローラの加熱セットポイントを経由して調整することができます。高い温度（約190℃）キセノンは偏光を構築するために、限られた時間を持っているコンパクトなセットアップのために良いです。 Xeを、N 2とHeの混合ガスは、レーザービーム方向と反対ポンピングセル（ 図3）を通って流れる。レーザービームで整列外部磁場は、その目を確実にE IR光子は1つだけRbの遷移を励起しています。電子状態の緩和が速く、 &quot;間違った&quot;偏光と赤外線光子の放出を避けるために、非放射性である必要があります。ここで、N 2は、クエンチガスとして場に出る。他の1が連続してレーザー（ 図5）により枯渇しながら最終的には、Rbのシステムは、基底状態のサブレベルの1の人口過剰を構築します。 Rb原子の​​経験スピン - スピン相互作用と電子スピン分極に密着取得キセノンは、フリップフロップのプロセスでのXe核に転写される。 ポンピングセルの流出超偏極ガスは低温（ 図4b、図のようなもの）に起因するコンセントの数cm内チューブの壁に凝縮そのRbの蒸気の微量が含まれています。vivoアプリケーションでは 、しかし、追加の除去を必要とするであろうアルカリ金属（コールドトラップなどによる） の in vitro における experimeに対しそれはhyperpolarizerを離れると国税庁はガスで安全に行うことができる。テフロンチューブは、テスト·ソリューションでNMR実験を行うためにガラス装置の入口と偏光コンセントを接続します。マスフローコントローラは、NMRのセットアップに流入Xeの量を調整するために使用されます。彼らは、NMRパルスシーケンス内のコマンドによってトリガーされます。達成偏強化を確認した後、ガスは溶液状態の実験でNMR / MRI造影剤として使用することができます。 Xeは、水中で一定の溶解度（4.5ミリモル/ atm）および他の溶剤を持っています。したがって、すでにいくつかの液体の分布を表示するために造影剤として単独で機能することができます。しかし、そうでなければ不活性ガスを介して分子固有の情報を取得するために、特定の分子にNMR活性核をリンクさせることも可能である。溶解XEの分子ホストを提供することによって、それは、Xe NMR信号に分子特異性を付与することが可能である。これは、機会を提供していますデザイン官能造影剤-また、バイオセンサーと呼ばれる-このようなホスト構造は生物医学の関心のある特定の分析物（ 図6）に結合し、標的ユニットに結合されている。 バイオセンサーは、MR造影剤（&lt;100μM）のために低い濃度で検出されるべきであると、さらに感度の向上が必要となります。これは、化学交換飽和移動（CEST）することによって達成することができる。この方法では、ケージXeの磁化を破壊し、溶液中の遊離Xeのシグナル変化を観察することによって、間接的にバイオセンサーを検出します。超偏極核がいくつか連続して10ミリ秒後に交換されているので、多くの100から1000の核が検出されたプールに情報を転送し、信号CAを増幅する。 10 3倍（動画2参照）。

<table border="1"><tbody><tr><td> 試薬の名称 </td><td> 会社 </td><td> カタログ番号 </td><td> コメント（オプション） </td></tr><tr><td> Rbのインゴット</td><td>シグマアルドリッチ</td><td> 276332-1G </td><td></td></tr><tr><td> P 4 O 10 </td><td>シグマアルドリッチ</td><td> 79610-500G </td><td></td></tr><tr><td> AR </td><td> Praxair社</td><td></td><td></td></tr><tr><td> Xeの</td><td>シグマアルドリッチ</td><td> 00472-1EA </td><td></td></tr><tr><td> O 2 </td><td>シグマアルドリッチ</td><td> 00476-1EA </td><td></td></tr><tr><td>レーザーシステム</td><td> QPCレーザー/レーザー操作</td><td> Brightlock 50 </td><td></td></tr><tr><td>真空システム</td><td>ファイファー</td><td> HiCube </td><td></td></tr><tr><td>熱電対</td><td>ニューポートオメガ</td><td> SA2F-KI-3M </td><td></td></tr><tr><td>シリコンヒーター</td><td>ニューポートオメガ</td><td> FMA5514 </td><td></td></tr><tr><td>圧力変換器</td><td>ニューポートオメガ</td><td> PRの33X-V-10 </td><td></td></tr><tr><td>プロセス計</td><td>ニューポートオメガ</td><td> INFCP-100B </td><td></td></tr><tr><td>マスフローコントローラ</td><td>ニューポートオメガ</td><td> MFC </td><td></td></tr><tr><td> PIDレギュレータ</td><td>ニューポートオメガ</td><td> CN7800 </td><td></td></tr><tr><td>制御ソフトウェア</td><td>ニューポートオメガ</td><td> DASYLabの</td><td></td></tr><tr><td>データ収集</td><td>ニューポートオメガ</td><td> Daqboard 3000 </td><td></td></tr><tr><td>真空センサ</td><td>エリコン</td><td> TTR91 </td><td></td></tr><tr><td>真空コントローラ</td><td> VACOM </td><td> MVC-3 </td><td></td></tr><tr><td>ビームコリメータ</td><td> Thorlabs </td><td> F810SMA-780 </td><td></td></tr><tr><td>偏光ビームスプリッタキューブ</td><td> Thorlabs </td><td> GL15-B </td><td></td></tr><tr><td> λ/ 4波長板</td><td> Thorlabs </td><td> WPQ10M-780 </td><td></td></tr><tr><td>ビーム拡大レンズ</td><td> Thorlabs </td><td></td><td></td></tr><tr><td>光学分光計</td><td>オーシャンオプティクス</td><td> HR4000 </td><td></td></tr><tr><td>光ファイバ</td><td>オーシャンオプティクス</td><td></td><td></td></tr><tr><td>低圧のNMRチューブ</td><td> Wilmad </td><td> 513-7LPV-7 </td><td></td></tr><tr><td> 5ミリメートルNMR管</td><td>シグマアルドリッチ</td><td> HX58.1 </td><td></td></tr><tr><td>ヘルムホルツコイル</td><td> Phywe </td><td> 06960から00 </td><td></td></tr><tr><td> SILI融合CA毛細血管</td><td>ポリマイクロ</td><td> TSG 250350 </td><td></td></tr></tbody></table>

hyperpolarized xenon for nmr and mri applications

〜10Tのさえ強い外部磁界が室温1の検体のごく検出正味磁化を生成するため、核磁気共鳴（NMR）分光法とイメージング法（MRI）は、内因性の低感度に悩まされている。したがって、ほとんどのNMRやMRIのアプリケーションでは、相対的に高濃度の分子の検出（ 例えば 、生体組織のイメージングのための水）に依存するか、または過度の取得時間を必要とします。これは、多くの生化学的および医療用アプリケーションのためのNMR信号の非常に有用な分子の特異性を利用する当社の能力を制限しています。しかし、斬新なアプローチは、過去数年間で浮上している：前NMR / MRI磁石内部の検出、検出されたスピン種の操作が劇的に磁化を高めることができ、したがって、はるかに低い濃度で2分子の検出を可能にします。 ここでは、キセノンガス混合物（2〜5％のXe、10％の偏光するための方法を提示するCAとコンパクトなセットアップで、N 2、彼はバランス）。 16000倍の信号増強。近代的なライン狭めダイオードレーザーは、希ガスは他の成分から分離されていない場合でも、効率的な分極7およびガス混合物の直接の使用を許可します。燮装置について説明されており、達成スピン偏極の測定は、メソッドのパフォーマンス制御に実証されている。 超偏極ガスは、ガス流イメージングまたは他の材料8,9とのインタフェースでの拡散の研究を含めて、ボイドスペースイメージングのために使用することができます。また、XeのNMR信号は、その分子環境6に非常に敏感です。一時的にガス10,11を捕捉官能分子のホストとの水溶液に溶解したときにこれはNMR / MRI造影剤として使用するオプションを有効にします。直接検出するとこのような構築物の高感度間接的な検出は、分光とイメージングの両方のモードで示されています&lt;/ P&gt;

Watch this Scientific Journal Video about Hyperpolarized Xenon for NMR and MRI Applications at JoVE.com

Hyperpolarized Xenon for NMR and MRI Applications

光ポンピングスピン交換（ヒソプ）により過分極キセノンの生産が記載されている。このメソッドは、Xe-129の核スピン偏極の約10000倍増強をもたらし、核磁気共鳴分光法とイメージングのアプリケーションを持っています。気相と溶液状態実験の例が出されます。

NMRやMRIのアプリケーションのための過分極キセノン

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 ...

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19.5K ビュー.  Leibniz-Institut für Molekulare Pharmakologie. 光ポンピングスピン交換（ヒソプ）により過分極キセノンの生産が記載されている。このメソッドは、Xe-129の核スピン偏極の約10000倍増強をもたらし、核磁気共鳴分光法とイメージングのアプリケーションを持っています。気相と溶液状態実験の例が出されます。

ビデオ: Hyperpolarized Xenon for NMR and MRI Applications

Solid-state Graft Copolymer Electrolytes for Lithium Battery Applications

Battery safety has been a very important research area over the past decade. Commercially available lithium ion batteries employ low flash point (&lt;80 &deg;C), flammable, and volatile organic electrolytes. These organic based electrolyte systems are viable at ambient temperatures, but require a cooling system to ensure that temperatures do not exceed 80 &deg;C. These cooling systems tend to increase battery costs and can malfunction which can lead to battery malfunction and explosions, thus endangering human life. Increases in petroleum prices lead to a huge demand for safe, electric hybrid vehicles that are more economically viable to operate as oil prices continue to rise. Existing organic based electrolytes used in lithium ion batteries are not applicable to high temperature automotive applications. A safer alternative to organic electrolytes is solid polymer electrolytes. This work will highlight the synthesis for a graft copolymer electrolyte (GCE) poly(oxyethylene) methacrylate (POEM) to a block with a lower glass transition temperature (Tg) poly(oxyethylene) acrylate (POEA). The conduction mechanism has been discussed and it has been demonstrated the relationship between polymer segmental motion and ionic conductivity indeed has a Vogel-Tammann-Fulcher (VTF) dependence. Batteries containing commercially available LP30 organic (LiPF6 in ethylene carbonate (EC):dimethyl carbonate (DMC) at a 1:1 ratio) and GCE were cycled at ambient temperature. It was found that at ambient temperature, the batteries containing GCE showed a greater overpotential when compared to LP30 electrolyte. However at temperatures greater than 60 &deg;C, the GCE cell exhibited much lower overpotential due to fast polymer electrolyte conductivity and nearly the full theoretical specific capacity of 170 mAh/g was accessed.

Lithium ion batteries employ flammable and volatile organic electrolytes that are suitable for ambient temperature applications. A safer alternative to organic electrolytes are solid polymer batteries. Solid polymer batteries operate safely at high temperatures (&gt;120 &deg;C), thus making them applicable to high temperature applications such as deep oil drilling and hybrid electric vehicles. This paper will discuss (a) the polymer synthesis, (b) the polymer conduction mechanism, and (c) provide temperature cycling for both solid polymer and organic electrolytes.

リチウム電池アプリケーションのためのソリッドステートグラフトコポリマー電解質

Battery safety has been a very important research area over the past decade. Commercially available lithium ion batteries employ low flash point (&lt;80 ...

工学

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents

Imaging of hyperpolarized substrates by magnetic resonance shows great clinical promise for assessment of critical biochemical processes in real time. Due to fundamental constraints imposed by the hyperpolarized state, exotic imaging and reconstruction techniques are commonly used. A practical system for characterization of dynamic, multi-spectral imaging methods is critically needed. Such a system must reproducibly recapitulate the relevant chemical dynamics of normal and pathological tissues. The most widely utilized substrate to date is hyperpolarized [1-13C]-pyruvate for assessment of cancer metabolism. We describe an enzyme-based phantom system that mediates the conversion of pyruvate to lactate. The reaction is initiated by injection of the hyperpolarized agent into multiple chambers within the phantom, each of which contains varying concentrations of reagents that control the reaction rate. Multiple compartments are necessary to ensure that imaging sequences faithfully capture the spatial and metabolic heterogeneity of tissue. This system will aid the development and validation of advanced imaging strategies by providing chemical dynamics that are not available from conventional phantoms, as well as control and reproducibility that is not possible in vivo.

A multi-compartment dynamic phantom is used to simulate some biology of interest for metabolic studies using hyperpolarized magnet resonance agents.

過分極磁気共鳴剤の研究のための多区画動的単一酵素ファントムの使用

Imaging of hyperpolarized substrates by magnetic resonance shows great clinical promise for assessment of critical biochemical processes in real time. Due ...

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic recording of image sequences. The basic components, features, constraints and optimization tips of a 3D-PTV topology consisting of a high-speed camera with a four-view splitter are described and discussed in this article. The technique is applied to the intermediate flow field (5 &#60;x/d &#60;25) of a circular jet at Re &#8776; 7,000. Lagrangian flow features and turbulence quantities in an Eulerian frame are estimated around ten diameters downstream of the jet origin and at various radial distances from the jet core. Lagrangian properties include trajectory, velocity and acceleration of selected particles as well as curvature of the flow path, which are obtained from the Frenet-Serret equation. Estimation of the 3D velocity and turbulence fields around the jet core axis at a cross-plane located at ten diameters downstream of the jet is compared with literature, and the power spectrum of the large-scale streamwise velocity motions is obtained at various radial distances from the jet core.

A three-dimensional particle tracking velocimetry (3D-PTV) system based on a high-speed camera with a four-view splitter is described here. The technique is applied to a jet flow from a circular pipe in the vicinity of ten diameters downstream at Reynolds number Re &#8776; 7,000.

ジェット流の場合：乱流のアプリケーションのための3次元粒子追跡流速

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic ...

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors.

A protocol for the colloidal synthesis of silver nanocubes and fabrication of plasmonic nanoscale patch antennas with sub-10 nm gaps is presented.

プラズモニクスとナノフォトニクスでのアプリケーションのためのNanopatchアンテナのコロイド合成

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, &#960;-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (&#181;-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, &#181;-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.

光共振器およびレーザ応用のためのポリマーマイクロスフェアの作製

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, ...

Protocol for the Evaluation of MRI Artifacts Caused by Metal Implants to Assess the Suitability of Implants and the Vulnerability of Pulse Sequences

As the number of magnetic resonance imaging (MRI) scanners and patients with medical implants is constantly growing, radiologists increasingly encounter metallic implant-related artifacts in MRI, resulting in reduced image quality. Therefore, the MRI suitability of implants in terms of artifact volume, as well as the development of pulse sequences to reduce image artifacts, are becoming more and more important. Here, we present a comprehensive protocol which allows for a standardized evaluation of the artifact volume of implants on MRI. Furthermore, this protocol can be used to analyze the vulnerability of different pulse sequences to artifacts. The proposed protocol can be applied to T1- and T2-weighted images with or without fat-suppression and all passive implants. Furthermore, the procedure enables the separate and three-dimensional identification of signal loss and pile-up artifacts. As previous investigations differed greatly in evaluation methods, the comparability of their results was limited. Thus, standardized measurements of MRI artifact volumes are necessary to provide better comparability. This may improve the development of the MRI suitability of implants and better pulse sequences to finally improve patient care.

We describe a standardized method to evaluate magnetic resonance imaging artifacts caused by implants to estimate the suitability of the implants for magnetic resonance imaging and/or the vulnerability of different pulse sequences to metallic artifacts simultaneously.

インプラントの適合性とパルス シーケンスの脆弱性を評価するためにインプラントの金属による MRI アーチファクトの評価のためのプロトコル

As the number of magnetic resonance imaging (MRI) scanners and patients with medical implants is constantly growing, radiologists increasingly encounter ...

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in industry. The wettability of the produced surface was analyzed by bouncing drop experiments and the topography was analyzed by confocal microscopy. In addition, we show various methodologies to measure its durability and anti-icing properties. Superhydrophobic surfaces hold a special texture that must be preserved to keep their water-repellency. To fabricate durable surfaces, we followed two strategies to incorporate a resistant texture. The first strategy is a direct incorporation of roughness to the metal substrate by acid etching. After this surface texturization, the surface energy was decreased by silanization or fluoropolymer deposition. The second strategy is the growth of a ceria layer (after surface texturization) that should enhance the surface hardness and corrosion resistance. The surface energy was decreased with a stearic acid film.
The durability of the superhydrophobic surfaces was examined by a particle impact test, mechanical wear by lateral abrasion, and UV-ozone resistance. The anti-icing properties were explored by studying the ability to repeal subcooled water, freezing delay, and ice adhesion.

We illustrate several methodologies to produce superhydrophobic metal surfaces and to explore their durability and anti-icing properties.

防氷用超撥水の金属表面の作製

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in ...

Controllable Nucleation of Cavitation from Plasmonic Gold Nanoparticles for Enhancing High Intensity Focused Ultrasound Applications

In this study, plasmonic gold nanoparticles were simultaneously exposed to pulsed near-infrared laser light and high intensity focused ultrasound (HIFU) for the controllable nucleation of cavitation in tissue-mimicking gel phantoms. This in vitro protocol was developed to demonstrate the feasibility of this approach, for both enhancement of imaging and therapeutic applications for cancer. The same apparatus can be used for both imaging and therapeutic applications by varying the exposure duration of the HIFU system. For short duration exposures (10 &#181;s), broadband acoustic emissions were generated through the controlled nucleation of inertial cavitation around the gold nanoparticles. These emissions provide direct localization of nanoparticles. For future applications, these particles may be functionalized with molecular-targeting antibodies (e.g. anti-HER2 for breast cancer) and can provide precise localization of cancerous regions, complementing routine diagnostic ultrasound imaging. For continuous wave (CW) exposures, the cavitation activity was used to increase the localized heating from the HIFU exposures resulting in larger thermal damage in the gel phantoms. The acoustic emissions generated from inertial cavitation activity during these CW exposures was monitored using a passive cavitation detection (PCD) system to provide feedback of cavitation activity. Increased localized heating was only achieved through the unique combination of nanoparticles, laser light and HIFU. Further validation of this technique in pre-clinical models of cancer is necessary.

This protocol demonstrates the controllable nucleation of cavitation in gel phantoms, through simultaneous exposure to both near-infrared pulsed laser light and high intensity focused ultrasound (HIFU). The cavitation activity can then be used for enhancing imaging and/or therapeutic uses of HIFU.

高強度を強化するため金ナノ粒子プラズモニックからキャビテーションの制御可能な核集中超音波アプリケーション

In this study, plasmonic gold nanoparticles were simultaneously exposed to pulsed near-infrared laser light and high intensity focused ultrasound (HIFU) ...

Optimization, Test and Diagnostics of Miniaturized Hall Thrusters

Miniaturized spacecraft and satellites require smart, highly efficient and durable low-thrust thrusters, capable of extended, reliable operation without attendance and adjustment. Thermochemical thrusters which utilize thermodynamic properties of gases as a means of acceleration have physical limitations on their exhaust gas velocity, resulting in low efficiency. Moreover, these engines demonstrate extremely low efficiency at small thrusts and may be unsuitable for continuously operating systems which provide real-time adaptive control of the spacecraft orientation, velocity and position. In contrast, electric propulsion systems which use electromagnetic fields to accelerate ionized gases (i.e., plasmas) do not have any physical limitation in terms of exhaust velocity, allowing virtually any mass efficiency and specific impulse. Low-thrust Hall thrusters have a lifetime of several thousand hours. Their discharge voltage ranges between 100 and 300 V, operating at a nominal power of &lt;1 kW. They vary from 20 to 100 mm in size. Large Hall thrusters can provide fractions of millinewton of thrust. Over the past few decades, there has been an increasing interest in small mass, low power, and high efficiency propulsion systems to drive satellites of 50-200 kg. In this work, we will demonstrate how to build, test, and optimize a small (30 mm) Hall thruster capable of propelling a small satellite weighing about 50 kg. We will show the thruster operating in a large space environment simulator, and describe how thrust is measured and electric parameters, including plasma characteristics, are collected and processed to assess key thruster parameters. We will also demonstrate how the thruster is optimized to make it one of the most efficient small thrusters ever built. We will also address challenges and opportunities presented by new thruster materials.

Here, we present a protocol to test and optimize space propulsion systems based on miniaturized Hall-type thrusters.

最適化、テストおよび小型ホールスラ スターの診断

Miniaturized spacecraft and satellites require smart, highly efficient and durable low-thrust thrusters, capable of extended, reliable operation without ...

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites

In this work, an easy, low-cost, and widely applicable method was developed to improve the compatibility between the ceramic fillers and the polymer matrix by adding 3-aminopropyltriethoxysilane (KH550) as a coupling agent during the fabrication process of BaTiO3-P(VDF-CTFE) nanocomposites through solution casting. Results show that the use of KH550 can modify the surface of ceramic nanofillers; therefore, good wettability on the ceramic-polymer interface was achieved, and the enhanced energy storage performances were obtained by a suitable amount of the coupling agent. This method can be used to prepare flexible composites, which is highly desirable for the production of high-performance film capacitors. If an excessive amount of coupling agent is used in the process, the non-attached coupling agent can participate in complex reactions, which leads to a decrease in dielectric constant and an increase in dielectric loss.

Here, we demonstrate a simple and low-cost solution-casting process to improve the compatibility between the filler and the matrix of polymer-based nanocomposites using surface modified BaTiO3 fillers, which can effectively enhance the energy density of the composites.

ポリマー系ナノ複合材料の誘電特性向上のためのカップリング剤の応用

In this work, an easy, low-cost, and widely applicable method was developed to improve the compatibility between the ceramic fillers and the polymer ...