この作品は、BU / CIMIT応用医療工学博士号を取得する前のフェローシップ、工学への参加研究開始グラント（BRIGE）を広げる国立科学財団、国立衛生研究所（R21EB0094930）によってサポートされていました。

1。位相シフトナノエマルジョンの調製（PSNE） <ol><li> 11 mgのDPPCおよびクロロホルム中1.68ミリグラムDSPE-PEG2000を溶解</li><li>ガラス丸底フラスコに乾燥脂質膜を形成するために有機溶剤を蒸発させる</li><li>一晩脂質フィルムをDessicate </li><li>リン酸緩衝食塩水（PBS）の5.5ミリリットルと脂質膜を水和</li><li> 45℃の水浴中で熱ソリューションは、脂質膜は、定期的にボルテックスし、溶解するまで</li><li> 7ミリリットルバイアルに脂質溶液を移す</li><li> 20％の振幅で2分間脂質溶液を超音波処理</li><li> 2.5ミリリットルずつの2つのバイアルに溶液を分ける（残りの0.5ミリリットルを廃棄） </li><li>各バイアルに2.5 mlのPBSを追加</li><li> 0℃の氷水浴中で各バイアルを置きます</li><li>各バイアルに50μlのDDFPを追加</li><li>時間に25％の振幅、パルスモード（10秒オン、50秒オフ）、60秒合計：次の設定を使用して氷水浴中で各バイアルを超音波処理</li><li> TR20mlのシンチレーションバイアルにansfer PSNEソリューション</li><li> 10ミリリットル最終容量で、その結果、各バイアルに5mlのPBSを追加</li><li>製造業者によって提供さ押出次の方向を組み立てる<ol><li>脱イオン水を用いて、各部分をすすぐ</li><li>フィルタ支持基盤の中心にステンレス製のサポートディスクを置きます</li><li>ステンレス鋼のサポートディスクの上にステンレスメッシュを配置</li><li>ピンセットを使用して、ステンレス製のメッシュで押出機ドレンディスク膜（光沢のある面を上に）置く</li><li>ピンセットを使用して、ドレインディスク膜上に押出機フィルター（光沢のある面を上に）置く</li><li>慎重にフィルター上に小さなOリングを配置し、支持基盤上thermobarrelと押出機の上部に置く</li><li>部分的に第1の各ウィングナットを締め、その後完全に交互に手でウィングナットを締め</li><li>に押出機を接続窒素ガスライン</li><li>トップサンプルポートに押出機、ピペット10ミリリットルの脱イオン水を準備するために、開口部をキャップ、ベントバルブを締め</li><li>ゆっくり膜を通してサンプルを強制的に圧力を増加させ、出口チューブからサンプルを収集するために窒素ガスラインを開く</li><li>使用後は、逆の順序で分解し脱イオン水を用いて押出機の部品をすすぎ、メンブレンフィルターとメンブレンドレインディスクを破棄</li></ol></li><li> 200nmのフィルターを通して10回押し出して、100nmの液滴の場合のみ、事前条件PSNE </li><li>フィルターは100nm〜200nmで押し出しPSNEの16倍狭い粒度分布を得るために</li></ol> 2。 PSNEを含むポリアクリルアミドハイドロゲルの調製<ol><li> 5ミリリットルの脱イオン水に1.2グラムのBSA粉末を希釈することによって、24％BSA溶液を準備</li><li> 1ミリリットル脱ウォートで希釈し0.1グラムのAPS粉で10％APS溶液を準備R </li><li>次の順序で、2.1ミリリットルのアクリルアミド溶液、1.2ミリリットルのトリス緩衝液、0.1mlの10％APS、4.5ミリリットル24パーセントBSA溶液、プラスチックチャンバー内で脱イオン水3.6ミリリットルを混ぜる</li><li> 40℃、1時間真空下に置く熱</li><li> PSNEの480μlを加え、徹底的に優しくプラスチックチャンバーを回して混ぜる。 </li><li> 12μlのTEMEDを加え、2時間12℃の水浴で室を配置</li></ol> 3。代表的な結果組織模倣ハイドロゲルファントムによる超音波実験のセットアップの模式図を図1に示します。このプロトコルは、少なくとも1週間は溶液中で安定であり、狭いサイズ分布を有する脂質でコーティングされたパーフルオロカーボン液滴を生じる。動的光散乱（90Plus粒度分布測定装置、ブルックヘブンインスツルメンツ、ホールトヴィル、ニューヨーク州）を用いて測定粒度分布は、押し出さPSNEが100と200を使用するために、図2に示されていますnmのフィルター。動的光散乱法を用いて測定時間をかけPSNE有効径は、PSNEは、少なくとも1週間は安定していることを実証し、表1に示します。ポリアクリルアミドハイドロゲルの気化前後PSNEのBモード画像を図3に示します。また、アルブミンとPSNEを含むポリアクリルアミドハイドロゲルにおけるHIFU媒介の15によって形成された病変秒加熱は、 図4に示されている。病変の非対称形状は、超音波経路における気泡雲の存在に起因して発生するprefocal加熱の結果です。これは、送信された音響の電力を低減することで最小限に抑えることができ、そのprefocal加熱や気泡からの散乱に起因する病変形成に注意することが重要である。 <img src="/files/ftp_upload/4308/4308fig1.jpg" alt="図1"/> 図1：組織-MIMと超音波実験のための実験装置の模式図ヒドロゲルをicking。 <img src="/files/ftp_upload/4308/4308fig2.jpg" alt="図2"/> 図2：サイズ100 nmまたは200 nmのフィルターを通して押し出さPSNEの分布は、動的光散乱法を用いて測定。縦軸の単位は、サンプルからトータル散乱光強度に対して一定の大きさの粒子からの散乱光の強度に基づいています。 <img src="/files/ftp_upload/4308/4308fig3.jpg" alt="図3"/> （3）Bモード画像（）の前と（b）のポリアクリルアミドハイドロゲル中PSNE気化した後の図 。矢印はバブル雲がPSNE蒸発によって形成された震源域を示しています。 <img src="/files/ftp_upload/4308/4308fig4.jpg" alt="図4"/> 図4 polyacrの画像アルブミンとPSNE含むイルアミドハイドロゲルは、（a）、HIFUによる気化、超音波処理前と（b）の後、超音波誘導加熱の結果として病巣の形成を実証しています。超音波の中心周波数は3.3 MHzである。超音波信号は、直ちに0.77 Wで連続的な超音波の15秒、続いてPSNEを蒸発させるために最初の30サイクル、6.4 Wのパルスで構成されてい<table border="1"><tbody><tr><td rowspan="2"> 押出後の日 </td><td colspan="2"> 200 nmフィルターで押し出し </td><td colspan="2"> 100 nmフィルターで押し出し </td></tr><tr><td> 径を意味します。 （NM） </td><td> STD。 devの。 （NM） </td><td> 径を意味します。 （NM） </td><td> STD。 devの。 （NM） </td></tr><tr><td> 1 </td><td> 182.9 </td><td> 4.9 </td><td> 118.0 </td><td> 0.9 </td></tr><tr><td> 7 </td> &lt;TD&gt; 177.7 </td><td> 2.5 </td><td> 124.8 </td><td> 3.1 </td></tr></tbody></table> 表1。100 nmと200 nmのフィルターを備えた押出後の1及び7日目の直径とPSNEの標準偏差を平均値。

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高強度集束超音波（HIFU）は熱的に腫瘍を切除するために臨床的に使用されます。1が局部加熱を強化し、腫瘍内の熱焼灼を改善するために、脂質でコーティングされたパーフルオロカーボン液滴は、HIFUによって蒸発させることができるが開発されてきた。多くの腫瘍における血管系が原因で彼らの急速な成長に異常漏出であり、図2は、このように、ナノ粒子は、腫瘍内に蓄?...

<table border="1"><tbody><tr><td> 共通名 </td><td> メーカー </td><td> 猫。数 </td><td> 完全な名前/説明 </td></tr><tr><td> DPPC </td><td>アヴァンティ脂質、アラバスター、アラバマ、米国</td><td> 850355P </td><td> 1,2 - ジパルミトイル-sn-グリセロ-3 - ホスホコリン</td></tr><tr><td> DSPE-PEG2000 </td><td>アヴァンティ脂質、アラバスター、アラバマ、米国</td><td> 880120P </td><td> 1,2 - ジステアロイル-sn-グリセロ-3 - ホスホエタノールアミン-N-[メトキシ（ポリエチレングリコール）-2000]（アンモニウム塩） </td></tr><tr><td> DDFP </td><td> Fluoromed、ラウンドロック、テキサス州、アメリカ合衆国</td><td> CAS：138495-42-8 </td><td>ドデカ（C 5 F 12） </td></tr><tr><td> PBS </td><td> Sigma-Aldrich社、セントルイス、ミズーリ州、米国</td><td> P2194 </td><td>リン酸緩衝生理食塩水</td></tr><tr><td>クロロホルム</td><td> Sigma-Aldrich社、セント。ルイ、ミズーリ州、米国</td><td> 372978 </td><td>クロロホルム</td></tr><tr><td>アクリルアミド</td><td> Sigma-Aldrich社、セントルイス、ミズーリ州、米国</td><td> A9926 </td><td> 40パーセント19時01アクリルアミド/ビスアクリルアミド</td></tr><tr><td>トリス緩衝液</td><td> Sigma-Aldrich社、セントルイス、ミズーリ州、米国</td><td> T2694 </td><td> 1M、pHを8、トリズマ塩酸塩とトリズマベース</td></tr><tr><td> BSA </td><td> Sigma-Aldrich社、セントルイス、ミズーリ州、米国</td><td> A3059 </td><td>ウシ血清アルブミン</td></tr><tr><td> APS </td><td> Sigma-Aldrich社、セントルイス、ミズーリ州、米国</td><td> A3678 </td><td>過硫酸アンモニウム溶液</td></tr><tr><td> TEMED </td><td> Sigma-Aldrich社、セントルイス、ミズーリ州、米国</td><td> 87689 </td><td> N、N、N &#39;、N&#39;-テトラメチルエチレンジアミン</td></tr><tr><td></td><td></td><td></td><td> 機器 </td></tr><tr><td>ソニケーター（3mmの先端） </TD&gt; <td>ソニックス＆マテリアルズ、ニュータウン、コネチカット州、アメリカ合衆国</td><td>振動セル</td><td></td></tr><tr><td>水浴</td><td>サーモフィッシャーサイエンティフィック、ウォルサム、マサチューセッツ州、米国</td><td> Neslab EX-7 </td><td></td></tr><tr><td>押出機</td><td>ノーザン脂質、バーナビー、BC、カナダ</td><td>ライペックス</td><td></td></tr><tr><td>押出機フィルター</td><td>ワットマン、ピスカタウェイ、NJ、USA </td><td> Nuclepore＃110605と＃110606 </td><td></td></tr><tr><td>押出機ドレインディスク</td><td> Sterlitechコーポレーションケント、ワシントン州、アメリカ合衆国</td><td> ＃PETEDD25100 </td><td></td></tr><tr><td>プラスチック容器</td><td>米国プラスチック（株）、リマ、オハイオ州、米国</td><td> ＃55288、1 3/16 &quot;×3/16&quot;×2 7/16 &quot; </td><td></td></tr></tbody></table>

synthesis of phase-shift nanoemulsions with narrow size distributions for acoustic droplet vaporization and bubble-enhanced ultrasound-mediated ablation

高強度集束超音波（HIFU）は、熱的に腫瘍を切除するために臨床的に使用されます。局部加熱を強化し、腫瘍内の熱焼灼を改善するために、脂質でコーティングされたパーフルオロカーボン液滴は、HIFUによって蒸発させることができるが開発されてきた。多くの腫瘍における血管系が原因で彼らの急速な成長に異常漏出であり、ナノ粒子は、開窓を貫通し、受動的に腫瘍内に蓄積することができます。このように、液滴の大きさを制御することは腫瘍内の良い蓄積をもたらすことができます。本報告では、狭いサイズ分布を有する位相シフトナノエマルジョン（PSNE）で安定した液滴の調製が記載されている。 PSNEは液体パーフルオロカーボンの存在下で脂質溶液を超音波処理することによって合成した。狭いサイズ分布は、100または200 nmの細孔径を持つフィルタを使うPSNE複数回押し出すことにより得られた。粒度分布は、動的光散乱法を用いて7日間にわたって測定した。 PolyacPSNEを含むrylamideのヒドロゲルは、in vitroの実験のために調製した。ヒドロゲルでPSNE滴は、超音波および結果として生じる泡強化局所的に加熱して気化された。気化PSNEはより急速加熱を可能にし、また熱アブレーションに必要な超音波強度を低減します。したがって、PSNEは、潜在的にHIFU媒介熱アブレーション治療の治療成績を向上させ、腫瘍内の熱アブレーションを高めることが期待される。

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Synthesis of Phase-shift Nanoemulsions with Narrow Size Distributions for Acoustic Droplet Vaporization and Bubble-enhanced Ultrasound-mediated Ablation

位相シフトナノエマルジョン（PSNE）は局所的な加熱を強化し、腫瘍内の熱焼灼を向上させるために高強度集束超音波を用いて蒸発させることができる。本報告では、狭いサイズ分布を有する安定したPSNEの調製が記載されている。さらに、超音波媒介アブレーションで気化PSNEの影響は組織模倣ファントムに示されています。

アコースティック液滴蒸発とバブルが強化された超音波媒介アブレーションのための狭いサイズ分布を有する位相シフトナノエマルジョンの合成

High-intensity  focused ultrasound (HIFU) is used clinically to thermally ablate tumors. To  enhance localized heating and improve thermal ablation in ...

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JoVE Journal

Engineering

11.0K ビュー.  Boston University. 位相シフトナノエマルジョン（PSNE）は局所的な加熱を強化し、腫瘍内の熱焼灼を向上させるために高強度集束超音波を用いて蒸発させることができる。本報告では、狭いサイズ分布を有する安定したPSNEの調製が記載されている。さらに、超音波媒介アブレーションで気化PSNEの影響は組織模倣ファントムに示されています。

ビデオ: Synthesis of Phase-shift Nanoemulsions with Narrow Size Distributions for Acoustic Droplet Vaporization and Bubble-enhanced Ultrasound-mediated Ablation

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

For aqueous based supramolecular polymers, the simultaneous control over shape, size and stability is very difficult1. At the same time, the ability to do so is highly important in view of a number of applications in functional soft matter including electronics, biomedical engineering, and sensors. In the past, successful strategies to control the size and shape of supramolecular polymers typically focused on the use of templates2,3, end cappers4 or selective solvent techniques5. 
Here we disclose a strategy based on self-assembling discotic amphiphiles that leads to the control over stack length and shape of ordered, chiral columnar aggregates. By balancing electrostatic repulsive interactions on the hydrophilic rim and attractive non-covalent forces within the hydrophobic core of the polymerizing building block, we manage to create small and discrete spherical objects6,7. Increasing the salt concentration to screen the charges induces a sphere-to-rod transition. Intriguingly, this transition is expressed in an increase of cooperativity in the temperature-dependent self-assembly mechanism, and more stable aggregates are obtained. 
For our study we select a benzene-1,3,5-tricarboxamide (BTA) core connected to a hydrophilic metal chelate via a hydrophobic, fluorinated L-phenylalanine based spacer (Scheme 1). The metal chelate selected is a Gd(III)-DTPA complex that contains two overall remaining charges per complex and necessarily two counter ions. The one-dimensional growth of the aggregate is directed by &pi;-&pi; stacking and intermolecular hydrogen bonding. However, the electrostatic, repulsive forces that arise from the charges on the Gd(III)-DTPA complex start limiting the one-dimensional growth of the BTA-based discotic once a certain size is reached. At millimolar concentrations the formed aggregate has a spherical shape and a diameter of around 5 nm as inferred from 1H-NMR spectroscopy, small angle X-ray scattering, and cryogenic transmission electron microscopy (cryo-TEM). The strength of the electrostatic repulsive interactions between molecules can be reduced by increasing the salt concentration of the buffered solutions. This screening of the charges induces a transition from spherical aggregates into elongated rods with a length &gt; 25 nm. Cryo-TEM allows to visualise the changes in shape and size. In addition, CD spectroscopy permits to derive the mechanistic details of the self-assembly processes before and after the addition of salt. Importantly, the cooperativity -a key feature that dictates the physical properties of the produced supramolecular polymers- increases dramatically upon screening the electrostatic interactions. This increase in cooperativity results in a significant increase in the molecular weight of the formed supramolecular polymers in water.

The goal of this experiment is to determine and control the size, shape and stability of self-assembled discotic amphiphiles in water. For aqueous based supramolecular polymers such level of control is very difficult. We apply a strategy using both repulsive and attractive interactions. The experimental techniques applied to characterize this system are broadly applicable.

水中での超分子ポリマーのサイズ、形状と安定性を制御する

For aqueous based supramolecular polymers, the simultaneous control over shape, size and stability is very difficult1. At the same time, the ability to do ...

工学

Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

This paper discusses fluorescent core microcavity-based sensors that can operate in a microfluidic analysis setup. These structures are based on the formation of a fluorescent quantum-dot (QD) coating on the channel surface of a conventional microcapillary. Silicon QDs are especially attractive for this application, owing in part to their negligible toxicity compared to the II-VI and II-VI compound QDs, which are legislatively controlled substances in many countries. While the ensemble emission spectrum is broad and featureless, an Si-QD film on the channel wall of a capillary features a set of sharp, narrow peaks in the fluorescence spectrum, corresponding to the electromagnetic resonances for light trapped within the film. The peak wavelength of these resonances is sensitive to the external medium, thus permitting the device to function as a refractometric sensor in which the QDs never come into physical contact with the analyte. The experimental methods associated with the fabrication of the fluorescent-core microcapillaries are discussed in detail, as well as the analysis methods. Finally, a comparison is made between these structures and the more widely investigated liquid-core optical ring resonators, in terms of microfluidic sensing capabilities.

Fluorescent-core microcavity sensors employ a high-index quantum-dot coating in the channel of silica microcapillaries. Changes in the refractive index of fluids pumped into the capillary channel cause shifts in the microcavity fluorescence spectrum that can be used to analyze the channel medium.

Refractometricセンシング用蛍光コアマイクロキャビティの合成と操作

This paper discusses  fluorescent core microcavity-based sensors that can operate in a microfluidic  analysis setup. These structures are based on the ...

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.

The Vaporization of a Sacrificial Component (VaSC) process is used to fabricate microvascular structures. This procedure uses sacrificial poly(lactic) acid fibers to form hollow microchannels with precise 3D geometric positioning provided by laser micromachined guide plates.

犠牲成分の蒸発を用いた三次元微細構造を作る過程

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material ...

Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we present the fabrication protocol for a multilayered SAW acoustic counterflow device. The device is fabricated starting from a lithium niobate (LN) substrate onto which two interdigital transducers (IDTs) and appropriate markers are patterned. A polydimethylsiloxane (PDMS) channel cast on an SU8 master mold is finally bonded on the patterned substrate. Following the fabrication procedure, we show the techniques that allow the characterization and operation of the acoustic counterflow device in order to pump fluids through the PDMS channel grid. We finally present the procedure to visualize liquid flow in the channels. The protocol is used to show on-chip fluid pumping under different flow regimes such as laminar flow and more complicated dynamics characterized by vortices and particle accumulation domains.

In this video we first describe fabrication and operation procedures of a surface acoustic wave (SAW) acoustic counterflow device. We then demonstrate an experimental setup that allows for both qualitative flow visualization and quantitative analysis of complex flows within the SAW pumping device.

表面弾性波駆動型アコースティック·逆流マイクロフルイディクスで製作、操作と流れの可視化

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we ...

Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model

Analysis of the size distribution of nanocrystals is a critical requirement for the processing and optimization of their size-dependent properties. The common techniques used for the size analysis are transmission electron microscopy (TEM), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL). These techniques, however, are not suitable for analyzing the nanocrystal size distribution in a fast, non-destructive and a reliable manner at the same time. Our aim in this work is to demonstrate that size distribution of semiconductor nanocrystals that are subject to size-dependent phonon confinement effects, can be quantitatively estimated in a non-destructive, fast and reliable manner using Raman spectroscopy. Moreover, mixed size distributions can be separately probed, and their respective volumetric ratios can be estimated using this technique. In order to analyze the size distribution, we have formulized an analytical expression of one-particle PCM and projected it onto a generic distribution function that will represent the size distribution of analyzed nanocrystal. As a model experiment, we have analyzed the size distribution of free-standing silicon nanocrystals (Si-NCs) with multi-modal size distributions. The estimated size distributions are in excellent agreement with TEM and PL results, revealing the reliability of our model.

We demonstrate how to determine the size distribution of semiconductor nanocrystals in a quantitative manner using Raman spectroscopy employing an analytically defined multi-particle phonon confinement model. Results obtained are in excellent agreement with the other size analysis techniques like transmission electron microscopy and photoluminescence spectroscopy.

多粒子フォノン閉じ込めモデルとラマン分光法を用いて、ナノ結晶のサイズ分布の特性

Analysis of the size distribution of nanocrystals is a critical requirement for the processing and optimization of their size-dependent properties. The ...

Characterization of Full Set Material Constants and Their Temperature Dependence for Piezoelectric Materials Using Resonant Ultrasound Spectroscopy

During the operation of high power electromechanical devices, a temperature rise is unavoidable due to mechanical and electrical losses, causing the degradation of device performance. In order to evaluate such degradations using computer simulations, full matrix material properties at elevated temperatures are needed as inputs. It is extremely difficult to measure such data for ferroelectric materials due to their strong anisotropic nature and property variation among samples of different geometries. Because the degree of depolarization is boundary condition dependent, data obtained by the IEEE (Institute of Electrical and Electronics Engineers) impedance resonance technique, which requires several samples with drastically different geometries, usually lack self-consistency. The resonant ultrasound spectroscopy (RUS) technique allows the full set material constants to be measured using only one sample, which can eliminate errors caused by sample to sample variation. A detailed RUS procedure is demonstrated here using a lead zirconate titanate (PZT-4) piezoceramic sample. In the example, the complete set of material constants was measured from room temperature to 120 &#176;C. Measured free dielectric constants <img alt="Equation 1" src="/files/ftp_upload/53461/image001.jpg" /> and&#160;<img alt="Equation 2" src="/files/ftp_upload/53461/image002.jpg" /> were compared with calculated ones based on the measured full set data, and piezoelectric constants d15 and d33 were also calculated using different formulas. Excellent agreement was found in the entire range of temperatures, which confirmed the self-consistency of the data set obtained by the RUS.

This protocol describes the procedure of measuring the temperature dependence of the full set material constants of piezoelectric materials using resonant ultrasound spectroscopy (RUS).

フルセット材料定数のキャラクタリゼーションと共鳴超音波スペクトロスコピーを用いた圧電材料のための彼らの温度依存性

During the operation of high power electromechanical devices, a temperature rise is unavoidable due to mechanical and electrical losses, causing the ...

Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal microfluidic device. W/O microdroplets have recently been used in powerful methods that enable miniaturized chemical experiments. Therefore, developing a versatile method to yield monodisperse W/O microdroplets is needed. We have developed a method for generating monodisperse W/O microdroplets based on a capillary-based centrifugal axisymmetric co-flowing microfluidic device. We succeeded in controlling the size of microdroplets by adjusting the capillary orifice. Our method requires equipment that is easier-to-use than with other microfluidic techniques, requires only a small volume (0.1-1 &#181;l) of sample solution for encapsulation, and enables the production of hundreds of thousands number of W/O microdroplets per second. We expect this method will assist biological studies that require precious biological samples by conserving the volume of the samples for rapid quantitative analysis biochemical and biological studies.

Here, we demonstrate a simple production method for size-controllable, monodisperse, water-in-oil (W/O) microdroplets using a capillary-based centrifugal microfluidic device. This method requires only a small sample volume and enables high-yield production. We expect this method will be useful for rapid biochemical and cellular analyses.

単分散微小液滴のサイズ制御可能な形成のためのキャピラリーベースの遠心マイクロ流体デバイス

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal ...

Fabrication and Operation of Acoustofluidic Devices Supporting Bulk Acoustic Standing Waves for Sheathless Focusing of Particles

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must be smaller than the incident wavelength of sound and the width of the fluidic channels are typically tens to hundreds of micrometers across, acoustofluidic devices typically use ultrasonic waves generated from a piezoelectric transducer pulsating at high frequencies (in the megahertz range). At characteristic frequencies that depend on the geometry of the device, it is possible to induce the formation of standing waves that can focus particles along desired fluidic streamlines within a bulk flow. Here, we describe a method for the fabrication of acoustophoretic devices from common materials and clean room equipment. We show representative results for the focusing of particles with positive or negative acoustic contrast factors, which move towards the pressure nodes or antinodes of the standing waves, respectively. These devices offer enormous practical utility for precisely positioning large numbers of microscopic entities (e.g., cells) in stationary or flowing fluids for applications ranging from cytometry to assembly.

Acoustofluidic devices use ultrasonic waves within microfluidic channels to manipulate, concentrate and isolate suspended micro and nanoscopic entities. This protocol describes the fabrication and operation of such a device supporting bulk acoustic standing waves to focus particles in a central streamline without the aid of sheath fluids.

作製とAcoustofluidicのデバイスの動作は、粒子のフォーカシングSheathlessためのバルク弾性定在波を支援

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must ...

Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.

We present protocols to be used in the measurement of spray droplet size from agricultural nozzles used in both aerial and ground based agrochemical applications. These methods presented were developed to provide consistent and repeatable droplet size data both inter- and intra-laboratory, when using laser diffraction systems.

レーザー回折を使用した農業ノズルから測定スプレー液滴サイズ

When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to ...

A Pipette-Tip Based Method for Seeding Cells to Droplet Microfluidic Platforms

Amongst various microfluidic platform designs frequently used for cellular analysis, droplet-microfluidics provides a robust tool for isolating and analyzing cells at the single-cell level by eliminating the influence of external factors on the cellular microenvironment. Encapsulation of cells in droplets is dictated by the Poisson distribution as a function of the number of cells present in each droplet and the average number of cells per volume of droplet. Primary cells, especially immune cells, or clinical specimens can be scarce and loss-less encapsulation of cells remains challenging. In this paper, we present a new methodology that uses pipette-tips to load cells to droplet-based microfluidic devices without the significant loss of cells. With various cell types , we demonstrate efficient cell encapsulation in droplets that closely corresponds to the encapsulation efficiency predicted by the Poisson distribution. Our method ensures loss-less loading of cells to microfluidic platforms and can be easily adapted for downstream single cell analysis, e.g., to decode cellular interactions between different cell types.

This article presents a protocol for seeding scarce population of cells using pipette-tips to droplet microfluidic devices in order to provide higher encapsulation efficiency of cells in droplets.

ピペット チップを用いた液滴マイクロ流体プラットフォームに播種細胞メソッド

Amongst various microfluidic platform designs frequently used for cellular analysis, droplet-microfluidics provides a robust tool for isolating and ...