이 연구 프로젝트는 유럽 공동체의 7 번째 프레임 워크 프로그램 (FP7/2007-2013) / ERC 보조금 협정 N ° 242710 아래에있는 유럽 연구위원회의 자금 지원을 받아했으며 추가로 인간 프론티어 과학 프로그램과 독일의 에미 Noether 프로그램에 의해 지원되었다 연구 재단 (SCHR 995/2-1).

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관심 없음 충돌이 선언 없습니다.

hyperpolarized 크세논의 준비에 중요한 측면은 펌핑 셀 및 circularly 편광과 세포의 충분한 조명을 포함한 가스 매니 폴드에 산소 불순물 수 있습니다. 위에서 언급 한 전구 검사 루비듐를 전송하는 동안 해로운 산소 농도를 감지하는 간단한 방법입니다. 알칼리 금속은 셀이 편광판에 설치되어있는 시간까지의 반짝이는 표면을 상실 할 수 있습니다. . 한 번, 그러나, 비 산화 RB의 충분한 기화가 감소 레?...

사람들이 특정 상황에서 2 감도 문제를 해결할 수 있기 때문에 Hyperpolarized 요원이 NMR / MRI 응용 프로그램 증가 관심을 받고있다. 모두가 전에 실제 분광이나 이미징 실험 NMR 자석 밖에서 인위적으로 증가 스핀 인구 차이를 준비하는 세 가지 주요 방법은 현재 (및 교환 광학 펌핑, SEOP를 돌리다; 파라 수소 유도 분극, PHIP 동적 핵 분극, DNP) 사용 . 여기 솔루션 상태 실험에 사용 hyperpolarized 129 XE의 생산에 최적화 된 SEOP 설정의 기능과 작동에 대해 설명합니다. 필수 구성 요소는 795 nm의에서 적외선 광자를 방출 강렬한 광원입니다. 레이저 다이오드 어레이 (LDA)는 높은 전력 출력을 저렴한 비용으로&gt; 100 W를 제공 편리한 장치입니다. 많은 설정에서 LDA는 더 많거나 적은이 일의 편광을 유지하는 광학 섬유로 배출된다전자 레이저 빛. 충분한 SEOP 과정을 보장하는 방법이 타원형 양극화는 고순도의 원형 편광으로 변환해야합니다. 편광 광학의 주요 구성 요소는 그림 1과 2에 표시된 시스템을 설정하는 것은 보충 영화 1 개략적으로 설명되어 있습니다. circularly 빛을 극성을하기 위해 먼저 전력 밀도를 줄이기위한 기본 빔 확장 광학 (예를 들어, 섬유 콜리메이터)에 섬유 끝을 연결합니다. 빛는 선형 편광을 생성, 편광 빔 스플리터 큐브를 통과한다. 이 큐브를 회전함으로써 우리는 파워 미터와 나머지 양극화의 기본 축을 결정할 수 있습니다. 최대 전송 큐브의 빠른 축이 주요 빛의 편광 축과 정렬되어있는 상황에 해당합니다. 높은 흡광 계수 (100,000 : 1 이상)의 조각은 편광 구성 요소의 좋은 분리를 얻을 수 있습니다. 이것은 테스트 할 수 있습니다첫 번째는 특별히 일반 빔의 최대 전송을 위해 정렬하는 동안 회전 분석기로 두 번째 빔 스플리터 큐브를 사용합니다. 전송 빛의 선형 편광이 확정되면, 795 nm의 설계 λ / 4 파장 판은 원형 편광으로 선형 변환 할 수있는 매우 일반적인 빔에 소개되어 있습니다. 이러한 목적을 위해, 파장 판의 빠른 축이 45 ° 빔 스플리터 큐브 빠른 축에 상대적으로 회전합니다. (원하는 경우, 추가 - 일반 빔에의 선형 편광 축 수직으로 반영 일반 빔의 원형 편광은 비슷한 방식으로 달성 될 수있다.) 원형 편광의 품질은 회전시 일정한 전송을 얻을 수 있어야 두 번째 빔 스플리터 큐브로 테스트 할 수 있습니다. 보조 빔 확장 광학 (갈릴리 망원경 구성의 예를 들어 두 렌즈는) 다음 완전히 전으로 빔 직경을 증가오븐 상자 안에 펌핑 프로세스의 유리 셀을 lluminate. 셀에 RB 증기에 의한 레이저 빛의 흡수는 상자의 끝에있는 펌핑 셀 뒤에 핀 구멍을 통해 모니터링됩니다 콜리메이터는 (셀 설치를 펌핑을위한 그림 3 참조 광학 분석기로 분석 할 수있는 감쇠 IR 빔을 수집 ). 펌핑 셀 외부 가열 메커니즘은 부분적으로 세포 (그림 4A) 안에 앉아 RB 비말을 증발하기 때문에 레이저 광 흡수가 발생합니다. 증기의 밀도는 각각의 PID 컨트롤러의 가열 세트 포인트를 통해 조정할 수 있습니다. 높은 온도 (ca. 190 ° C) 크세논가 양극화를 구축 할 시간을 제한 금액이 작은 설정을위한 좋은 수 있습니다. XE, N 2, 그는이 포함 된 가스 혼합물은 레이저 빔 방향에 반대 펌핑 셀 (그림 3)을 통해 흐른다. 레이저 빔으로 정렬 외부 자기장은 그 일을 보장합니다전자 IR의 광자는 하나 RB의 전환을 펌핑하고 있습니다. 전자 상태의 휴식은 빠른과 &#39;잘못된&#39;양극화와 IR 광자의 방출을 피하기 위해 비 발광해야합니다. 여기서, N 2는 잃게 가스로서 플레이에 있습니다. 다른 하나가 지속적으로 레이저 (그림 5)에 의해 소모되는 동안 결국, RB 시스템은 지상 상태 sublevels 중 하나의 인구 과잉을 구축합니다. RB 원자에 가까운 접촉 점점 크세논은 스핀 - 스핀 상호 작용을 경험과 전자 스핀 분극은 플립 플롭 과정에서 XE의 핵에 전송됩니다. 펌핑 감방에서 흐르는 hyperpolarized 가스. 생체 응용 프로그램에서는 그러나, 추가 제거를 낮은 온도 (4B 파악하기 위해 이와 유사한 것)으로 인해 콘센트 몇 cm 내에서 튜브 벽에 응축이 필요한 것을 RB 증기의 흔적 금액이 포함되어 알칼리 금속 (감기에 트랩을 통해 예를 들어)의 체외 experime의 반면이 hyperpolarizer를 떠나는 즉시 국세청은 가스와 안전하게 수행 할 수 있습니다. 테플론 튜브 테스트 솔루션에 NMR 실험을 수행 할 수있는 유리 장치의 입구와 편광판 콘센트를 연결합니다. 질량 유량 컨트롤러는 NMR 설치에 흐르는 XE의 양을 조정하는 데 사용됩니다. 그들은 NMR 펄스 시퀀스 명령을에 의해 실행됩니다. 달성 편광 향상을 확인 후, 가스 솔루션 상태 실험에서 NMR / MRI 대비 에이전트로 사용할 수 있습니다. XE는 물에 특정 용해도 (4.5 MM / ATM) 및 기타 용제가 있습니다. 따라서 이미 액체의 분포를 표시 할 수 대비 요원으로 자체 검색 할 수 있습니다. 그러나, 다른 불활성 가스를 통해 분자 특정 정보를 취득하기 위해 특정 분자에 NMR-활성 핵을 연결하는 것도 가능합니다. 용해 XE에 대한 분자 호스트를 제공함으로써, XE NMR 신호에 분자 특이성을 부여 할 수 있습니다. 이 할 수있는 기회를 제공디자인 작용 대비 에이전트 - 또한, 바이오 센서라고 - 같은 호스트 구조가 생명 관심의 특정 analytes (그림 6)에 바인딩 대상 장치에 연결된다. 바이오 센서는 MR 대비 에이전트 (&lt;100 μM)에 대한 낮은 농도에서 감지해야 할 때 추가로 감도를 향상이 필요합니다. 이것은 화학 교환 포화 전송 (중부 유럽 표준시)에 의해 달성 될 수있다. 이 방법은 갇힌 XE의 자화를 파괴 및 솔루션에서 무료로 XE의 신호 변화를 관찰하여 간접적으로 바이오 센서를 감지합니다. hyperpolarized 핵은 지속적으로 감지 수영장로 일부 10 밀리, 많은 100-1000 핵 전송 정보를 한 후 교체 및 신호 CA를 증폭되기 때문입니다. 10 3 배 (영화 2 참조).

<table border="1"><tbody><tr><td> 시약의 이름 </td><td> 회사 </td><td> 카탈로그 번호 </td><td> 코멘트 (선택 사항) </td></tr><tr><td> RB의 주괴 </td><td> 시그마 - 알드리치 </td><td> 276332-1G </td><td></td></tr><tr><td> P 4 O 10 </td><td> 시그마 - 알드리치 </td><td> 79610-500G </td><td></td></tr><tr><td> 아르곤 </td><td> Praxair </td><td></td><td></td></tr><tr><td> XE </td><td> 시그마 - 알드리치 </td><td> 00472 - 1EA </td><td></td></tr><tr><td> O이 </td><td> 시그마 - 알드리치 </td><td> 00476 - 1EA </td><td></td></tr><tr><td> 레이저 시스템 </td><td> QPC 레이저 / 레이저 운영 </td><td> Brightlock 50 </td><td></td></tr><tr><td> 진공 시스템 </td><td> 파이퍼 </td><td> HiCube </td><td></td></tr><tr><td> 열전대 </td><td> 뉴 포트 (Newport)오메가 </td><td> SA2F-KI-300 </td><td></td></tr><tr><td> 실리콘 히터 </td><td> 뉴 포트 오메가 </td><td> FMA5514 </td><td></td></tr><tr><td> 압력 변환기 </td><td> 뉴 포트 오메가 </td><td> PR 33X-V-10 </td><td></td></tr><tr><td> 프로세스 미터 </td><td> 뉴 포트 오메가 </td><td> INFCP-100B </td><td></td></tr><tr><td> 질량 유량 컨트롤러 </td><td> 뉴 포트 오메가 </td><td> MFC </td><td></td></tr><tr><td> PID 조절기 </td><td> 뉴 포트 오메가 </td><td> CN7800 </td><td></td></tr><tr><td> 제어 소프트웨어 </td><td> 뉴 포트 오메가 </td><td> DasyLab </td><td></td></tr><tr><td> 데이터 수집 </td><td> 뉴 포트 오메가 </td><td> Daqboard 3000 </td><td></td></tr><tr><td> 진공 센서 </td><td> Oerlikon </td><td> TTR91 </td><td></td></tr><tr><td> 진공 컨트롤러 </td><td> VACOM </td><td> MVC-3 </td><td></td></tr><tr><td> 빔 콜리메이터 </td><td> Thorlabs </td><td> F810SMA-780 </td><td></td></tr><tr><td> 편광 빔 스플리터 큐브 </td><td> Thorlabs </td><td> GL15-B </td><td></td></tr><tr><td> λ / 4 파장 판 </td><td> Thorlabs </td><td> WPQ10M-780 </td><td></td></tr><tr><td> 빔 확장 렌즈 </td><td> Thorlabs </td><td></td><td></td></tr><tr><td> 광학 분광계 </td><td> 바다 광학 </td><td> HR4000 </td><td></td></tr><tr><td> 광학 섬유 </td><td> 바다 광학 </td><td></td><td></td></tr><tr><td> 낮은 압력 NMR 관 </td><td> Wilmad </td><td> 513 - 7LPV-7 </td><td></td></tr><tr><td> 5mm NMR 관 </td><td> 시그마 - 알드리치 </td><td> HX58.1 </td><td></td></tr><tr><td> Helmholtz 코일 </td><td> Phywe </td><td> 06960-00 </td><td></td></tr><tr><td> 융합 siliCA 모세 혈관 </td><td> Polymicro </td><td> TSG 250,350 </td><td></td></tr></tbody></table>

hyperpolarized xenon for nmr and mri applications

~ 10 T의 강한 외부 자기장은 실내 온도 1의 샘플 만 작은 감지 그물 자화를 생성하기 때문에 핵 자기 공명 (NMR) 분광법 및 이미징 (MRI)는 고유 낮은 감도로 고통 받고 있습니다. 따라서, 대부분의 NMR과 MRI 응용 프로그램은 상대적으로 높은 농도 (예를 들면, 물 생물 조직의 이미징을위한)에서 분자의 검출에 의존하거나 과도한 수집 시간을 필요로합니다. 이것은 많은 생화학 및 의료 응용 프로그램에 대한 NMR 신호의 매우 유용한 분자 특이성을 악용 할 수있는 능력을 제한한다. 그러나 소설의 접근 방식은 지난 몇 년간에 부상 : 감지 스핀 종의 조작을 사전에 NMR / MRI 자석 내부의 검출에 크게 자화를 증가하기 때문에 훨씬 낮은 농도 2 분자의 검출을 허용 할 수 있습니다. 여기, 우리는 크세논 가스 혼합물 (2-5% XE, 10 %의 편광하기위한 방법을 제시N 2, CA와 컴팩트 설정에서 그는 균형). 16,000 배 신호 강화. 고귀한 가스가 다른 구성 요소에서 분리되지 않은 경우에도 현대적인 라인 좁혀 다이오드 레이저는 효율적인 편광 7 가스 혼합물의 즉시 사용 할 수 있습니다. SEOP 장치가 설명되어 있으며 달성 스핀 분극의 결정은 방법의 성능 제어 시연합니다. hyperpolarized 가스는 가스 유량 영상 또는 기타 자료 8,9와 인터페이스의 확산 연구 등의 무효 공간 영상에 사용할 수 있습니다. 또한, XE NMR 신호는 분자 환경 6 매우 민감합니다. 이 일시적으로 가스에게 10,11 함정에 작용 분자 호스트와 수용액에 용해 할 때 NMR / MRI 대비 에이전트로 사용 할 수있는 옵션이 있습니다. 직접 감지 및 구조의 높은 감도 간접적으로 감지 spectroscopic 및 이미징 모두 모드에서 증명된다. &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

광학 스핀 교환 (SEOP) 펌프에 의해 hyperpolarized 크세논의 생산 설명되어 있습니다. 이 방법은 XE-129의 핵 스핀 분극의 ~ 10,000 배 향상을 산출하고 핵 자기 공명 분광법 및 이미징에 응용 프로그램이 있습니다. 기상 및 솔루션 상태 실험의 예는 주어집니다.

NMR과 MRI 응용 프로그램 용 Hyperpolarized 지논

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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19.4K 조회수.  Leibniz-Institut für Molekulare Pharmakologie. 광학 스핀 교환 (SEOP) 펌프에 의해 hyperpolarized 크세논의 생산 설명되어 있습니다. 이 방법은 XE-129의 핵 스핀 분극의 ~ 10,000 배 향상을 산출하고 핵 자기 공명 분광법 및 이미징에 응용 프로그램이 있습니다. 기상 및 솔루션 상태 실험의 예는 주어집니다.

비디오: 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.

리튬 배터리 애플리케이션을위한 고체 그래프트 공중 합체 전해질

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

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공학

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.

과분극 자기 공명 에이전트의 연구 다중 구획 동적 단일 효소 팬텀의 사용

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.

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.

플라즈몬과 나노 포토닉스의 응용 프로그램에 대한 Nanopatch 안테나의 콜로이드 합성

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.

광 공진기 및 레이저 응용을위한 고분자 미소 구의 제조

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.

금속으로 인 한 MRI 아티팩트의 평가 대 한 프로토콜 임 플 란 트의 적합성 및 펄스 시퀀스의 취약성을 평가 하기 위해 임 플 란 트

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.

반 장식 응용 프로그램 Superhydrophobic 금속 표면의 제조

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.

고 강도 향상을 위한 Plasmonic 금 나노 입자에서 현상의 제어 Nucleation 집중 초음파 응용 프로그램

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.

최적화, 테스트 그리고 소형된 홀 로켓의 진단

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.

폴리머 기반 나노 복합체의 유전체 특성을 개선하기 위한 커플링 에이전트 적용

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