次のプロトコルは、メリーランド大学の制度的動物ケア、利用委員会、治験審査委員会で受け付けています。プロトコルに従う中央政府、州およびローカルの基準とガイドラインの定めるバイオ セーフティに関するメリーランド大学のポリシー。
1. 目のサンプルの郭清
<ol><li>
地元の食肉処理場や組織の銀行から目のサンプルを取得します。全体の眼球を取得した場合は、即座にレンズ、添付 zonules、硝子体を抽出します。 注: 下記詳細はブタと人間の目に適用されます。<ol>
<li>消毒手術ハサミ、鉗子を使用して、カットし、強膜を取り巻くすべての余分な組織を削除します。</li>
		<li>しっかりとその側に目を保持し、かみそりの刃を使用すると、目の角膜から 3 mm の側に沿って小切開。眼の中の硝子体に達している十分なカットの深さを確認します。</li>
		<li>はさみを使用して、慎重に目のまわりを切開に沿ってさらにカット.レンズを刺さない。代表的な画像を図 2に示します。</li>
		<li>一度目の外径がカットされて、鉗子を使った眼の後部組織を削除します。鉗子でレンズ、zonules、毛様体、および接続されている硝子体を分離します。代表的なイメージは図 2Bに示すように。</li>
		<li>はさみとピンセットを使って、レンズは MLS にフラットに置くことができるので余分な硝子体を削除します。 メモ: 角膜移植の場合、角膜のボタンは手術で使用され、世界の残りの部分は研究目的のために利用できます。ただし、この部分のグローブは、レンズ担架セットアップのティッシュの準備でまだ使用できます。後部が得られる場合にのみステップ 1.1.4–1.1.5 を実行のみです。</li>
	</ol>
</li>
	<li>すべて 15% の漂白剤溶液中 30 分間の後郭清を使用する機器を消毒します。</li>
</ol>2. トライアル アセンブリ マニュアル レンズ担架の
<ol><li>靴インデントの後ろの壁と靴自体の 5 mm 隙間が残っているので、MLS の底板に 10 mm の靴底と対応する靴トップを挿入します。</li>
	<li>上部と下部のプレートは、プレートを一緒にスナップを揃えるデバイスが今ばねの位置です。</li>
	<li>プレート ケースと底板の側面にある穴にストッパーのネジにプレートを挿入します。</li>
	<li>ベースにプレート ケースに挿入し、一直線に並べられたインデントにレンチを配置します。</li>
	<li>靴を元の伸縮位置に戻ります戻る反時計回りにひねるし、靴を契約する停止ネジに達するまでレンチを時計回りにねじる。</li>
</ol>3. レンズの装着
<ol><li>5 mm の差のまま靴インデントと靴自体の後ろの壁、MLS で底板に 10 mm の靴底を挿入します。</li>
	<li>底板の真ん中に抽出されたレンズは表向きに置きカーブタイプ鉗子を使用して、靴は、中央の穴にレンズを支えています。</li>
	<li>、クリッピングだけ zonules と硝子体に対応する靴の上部をはめ込みます。視覚的に、維持レンズ中心とした底板の可能な限り。</li>
	<li>手順 2.3-2.4.</li>
</ol>4. レンズの測定
<ol><li>ビデオやストレッチのプロセスの写真をキャプチャするために装置の上に直接イメージング システムを配置します。定規を事後処理で正確にサイズとスケール画像に画像のフレームに含めるようにしてください。 注: 任意の適切なイメージング システムはこの手順のため十分ですここでは、12 メガピクセル, オート フォーカス スマート フォンのサンプルから片方の足を使用します。</li>
	<li>しっかりとまだスムーズにレンズをストレッチする時計回りの方向にレンチを回転します。図 3では、ばねと伸ばされた状態で代表的なイメージを示しています。</li>
	<li>拡大レンズを撮影後、サンプルを安静時の状態に復元する反時計回りの方向にレンチを回転します。 注意: レンズの脱水症状を最小限にするために、タイムリーでレンズの測定を実行することが不可欠です。</li>
	<li>明らかに写真レンズの最終的な静止状態。</li>
</ol>5. データの解析
<ol><li>ImageJ に画像をアップロードし、「ポイント」機能を使用して、図 4に示すように、レンズのまわりを少なくとも 40 ポイントを選択します。「分析」→「メジャー」オプションを使用すると、各選択したポイントの位置をもたらします。</li>
	<li>(ソフトウェア例えばMATLAB を使用して) 半径とカイ二乗適合図 4Bに示すように生成するために場所という点に合います。ピクセル半径とエラーを撮影した定規を使用して測定値に変換します。</li>
	<li>2 尾 t 検定 MLS からストレッチの前後に個々 のレンズの比較を実行します。</li>
</ol>

<ol>
	<li>Von Helmholtz, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uber+die+akkommodation+des+auges.">Uber die akkommodation des auges.</a> Arch Ophthal. 1, 1-74 (1855).</li><li>Schachar, R. A., Black, T. D., Kash, R. L., Cudmore, D. P., Schanzlin, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mechanism+of+accommodation+and+presbyopia+in+the+primate.">The mechanism of accommodation and presbyopia in the primate.</a> Ann Ophthalmol. 27, 58-67 (1995).</li><li>Glasser, A., Campbell, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presbyopia+and+the+optical+changes+in+the+human+crystalline+lens+with+age.">Presbyopia and the optical changes in the human crystalline lens with age.</a> Vision Res. 38 (2), 209-229 (1998).</li><li>Reilly, M. A., Hamilton, P. D., Perry, G., Ravi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+behavior+and+natural+and+refilled+porcine+lenses+in+a+robotic+lens+stretcher.">Comparison of the behavior and natural and refilled porcine lenses in a robotic lens stretcher.</a> Exp Eye Res. 88, 483-494 (2009).</li><li>Langenbucher, A., Huber, S., Nguyen, N. X., Seitz, B., Gusek-Schneider, G. C., K&#252;chle, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+accommodation+after+implantation+of+an+accommodating+posterior+chamber+intraocular+lens.">Measurement of accommodation after implantation of an accommodating posterior chamber intraocular lens.</a> J Cataract Refract Surg. 29 (4), 677-685 (2003).</li><li>Ehrmann, K., Ho, A., Parel, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+analysis+of+the+accommodative+apparatus+in+primates.">Biomechanical analysis of the accommodative apparatus in primates.</a> Clin Exp Optom. 91 (4), 411 (2008).</li><li>Pinilla Cort&#233;s, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Protocols+for+Ex+Vivo+Lens+Stretching+Tests+to+Investigate+the+Biomechanics+of+the+Human+Accommodation+Apparatus.">Experimental Protocols for Ex Vivo Lens Stretching Tests to Investigate the Biomechanics of the Human Accommodation Apparatus.</a> Invest Ophthalmol Vis Sci. 56 (5), 2926 (2015).</li><li>Fisher, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+elastic+constants+of+the+human+lens.">The elastic constants of the human lens.</a> J Physiol. 212 (1), 147-180 (1971).</li><li>Eppig, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+eye+model+and+measurement+setup+for+investigating+accommodating+intraocular+lenses.">Biomechanical eye model and measurement setup for investigating accommodating intraocular lenses.</a> Z Med Ohys. 23 (2), 144-152 (2013).</li><li>Manns, F., Parel, , et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+of+Human+and+Monkey+Lenses+in+a+Lens+Stretcher.">Response of Human and Monkey Lenses in a Lens Stretcher.</a> Invest Ophthalmol Vis Sci. 48 (7), 3260 (2007).</li><li>Scarcelli, G., Kim, P., Yun, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+measurement+of+age-related+stiffening+in+the+crystalline+lens+by+Brillouin+optical+microscopy.">In vivo measurement of age-related stiffening in the crystalline lens by Brillouin optical microscopy.</a> Biophys J. 101 (6), 1539-1545 (2011).</li><li>Besner, S., Scarcelli, G., Pineda, R., Yun, S. -. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Vivo+Brillouin+Analysis+of+the+Aging+Crystalline+Lens.">In Vivo Brillouin Analysis of the Aging Crystalline Lens.</a> Invest Ophthalmol Vis Sci. 57 (13), 5093 (2016).</li><li>Cortes, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Protocols+for+Ex+Vivo+Lens+Stretching+Tests+to+Investigate+the+Biomechanics+of+the+Human+Accommodation+Apparatus.">Experimental Protocols for Ex Vivo Lens Stretching Tests to Investigate the Biomechanics of the Human Accommodation Apparatus.</a> Invest Ophthalmol Vis Sci. 56 (5), 2926-2932 (2015).</li><li>Bernal, A., Parel, J. -. M., Manns, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+for+Posterior+Zonular+Fiber+Attachment+on+the+Anterior+Hyaloid+Membrane.">Evidence for Posterior Zonular Fiber Attachment on the Anterior Hyaloid Membrane.</a> Invest Ophthalmol Vis Sci. 47 (11), 4708 (2006).</li><li>Kammel, R., Ackermann, R., Mai, T., Damm, C., Nolte, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pig+Lenses+in+a+Lens+Stretcher.">Pig Lenses in a Lens Stretcher.</a> Optom Vis Sci. 89 (6), 908-915 (2012).</li><li>Hahn, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+Ex+Vivo+Porcine+Lens+Shape+During+Simulated+Accommodation,+Before+and+After+fs-Laser+Treatment.">Measurement of Ex Vivo Porcine Lens Shape During Simulated Accommodation, Before and After fs-Laser Treatment.</a> Invest Ophthalmol Vis Sci. 56 (9), 5332-5343 (2015).</li><li>D'Antin, J. C., Cortes, L. P., Montenegro, G. A., Barraquer, R. I., Michael, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+a+portable+manual+stretching+device+to+simulate+accommodation.">Evaluation of a portable manual stretching device to simulate accommodation.</a> Acta Ophthalmol. 93 (255), (2015).</li><li>Pierscionek, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-related+response+of+human+lenses+to+stretching+forces.">Age-related response of human lenses to stretching forces.</a> Exp Eye Res. 60 (3), 325-332 (1995).</li><li>Marussich, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+Crystalline+Lens+Volume+During+Accommodation+in+a+Lens+Stretcher.">Measurement of Crystalline Lens Volume During Accommodation in a Lens Stretcher.</a> Invest Ophthalmol Vis Sci. 56 (8), 4239 (2015).</li><li>Martinez-Enriquez, E., P&#233;rez-Merino, P., Velasco-Ocana, M., Marcos, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=OCT-based+full+crystalline+lens+shape+change+during+accommodation+in+vivo.">OCT-based full crystalline lens shape change during accommodation in vivo.</a> Biomed Opt Exp. 8 (2), 918-933 (2017).</li></ol>

AB は Bioniko コンサルティング LLC の持分です。

我々 は、サンプルに担架をカップルにデュアル部分クランプ機構を用いたレンズの収容能力を勉強の正確かつ効率的な方法を提供する手法を考案した.宿泊施設の中にレンズを緩和、直径はチン小帯1,2,4,19の緩和に対する応答で減少します。メソッドは、クランプし、チン小帯の緊張を制御するこ...

宿泊施設は、人間の目は鋭い焦点に遠くまたは近くの距離でオブジェクトを参照する、水晶体の形を動的に調整することができるプロセスです。宿泊施設は、本質的に生体力学的プロセスです。神経系の刺激には、毛様体筋は、レンズ カプセル1,2のまわりにアタッチ チン毛様体に力を生成します。宿泊施設のバイオメカニクスの背後にある別の理論がありますが、最も広く受け入れられているはヘルムホルツ仮説です。仮説によればレンズは、遠くのオブジェクトのフォーカスに最適なレンズの薄形に対応する自然な伸ばされた状態でです。毛様体筋の契約、近いオブジェクトにフォーカスを変更して、チン小帯が緩和されます。ターンでは、レンズが厚くなる、前部と後部の表面曲率の増加します。これは近くのビジョンは、したがってより短い焦点距離1に必要な屈折力の増加に対応しています。
老眼をという条件で時間をかけて対応する能力が損なわれます。老眼年齢 50 によって皆に影響を与える、目の距離3までいくからフォーカスを動的に変更することができませんになります。老眼に対処するため、現在の方法、矯正レンズ、遠近両用メガネなど受動的。いくつかの面で近いオブジェクトに焦点を当てる能力を増加しながらこのような受動的な治療はレンズ4、5のダイナミック フォーカス機能を復元できません。効率的に、老眼の治療、またはおそらくそれを防ぐため、継続的宿泊施設をよりよく理解する必要があります。
焦点調節を研究するには、4,6,7,8,9前のヴィヴォ現象をシミュレートするデバイスの数が開発されています。回転ディスクはまず遠心力8を介してレンズの伸縮を監視に導入されました。現象をより忠実に複製するには、レンズ伸縮装置が徐々 に導入し、革新。レンズ担架、に対するらを使用しています。レンズ電源と赤道の直径9そのような相関しながらレンズを収めるために必要な力を特徴とします。現在の理解は、レンズ硬直毛様体3,10、11,12の等しい力に応じ、レンズ形状の減少変更を伴う年齢とともにです。
現在レンズ担架ではしばしば、複雑なセットアップでは、エレクトロニクスおよびプログラム可能な伸縮率の実装を含む全体死体眼球6,7,10,13を必要とします。この要件は実験目あたり 500.00 ドル以上あたりのコストを増加し、サンプルの可用性が低下します。眼後部の合計約 $200.00 と低コストで焦点調節をレプリケートする方法をご紹介します。しばらくの間、今日使用される多くのデバイスよりもより少なく洗練された技術はよりコスト効果的で採用可能な結果を損なうことがなくです。このメソッドは、図 1に描かれているマニュアル レンズ担架 (MLS) を中心とし、レンズの直径を拡大する、チンと放射状のねじれ法に関するユニークなクランプ システムを使用しています。ベルナルらの調査結果によって、プロトコルの生理学的な精度を検証します。、前部と後部のチンがレンズ カプセル14を接続する経路を勉強しました。生理学的宿泊施設をレプリケートすることによってレンズのバイオメカニクスを研究するのみレンズ、チン、毛様体を必要とするカスタムの靴のデザインを使用して、目指しました。

<table border="0" cellpadding="0" cellspacing="0" style="width:856px;" width="856">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:191px;">Manual Lens Stretcher</td>
			<td style="width:233px;">Bioniko</td>
			<td style="width:132px;">MLS</td>
			<td style="width:300px;">Different animal species will require different shoe sizes</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Porcine Eye Samples</td>
			<td>George G. Ruppersberger; slaughterhouse</td>
			<td>N/A</td>
			<td>Whole eyeballs were obtained</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Human Eye Samples</td>
			<td>The National Disease Research Interchange</td>
			<td>N/A</td>
			<td>Posterior poles without corneas were ordered</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Dissecting Scissors (5 1/2&#39;&#39; Straight)</td>
			<td>Electron Microsopy Sciences</td>
			<td>72960</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tissue Forceps (4 1/2&#39;&#39;)</td>
			<td>Electron Microsopy Sciences</td>
			<td>72960</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">iPhone 6s</td>
			<td>Apple</td>
			<td>N/A</td>
			<td>Any imaging system with ~0.1 mm resolution will work</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sodium Hypochorite</td>
			<td>Clorox</td>
			<td>Clorox Regular-Bleach</td>
			<td>Any disinfectant will work</td>
		</tr>
	</tbody>
</table>

simulating the mechanics of lens accommodation via a manual lens stretcher

このプロトコルの目的は、コスト効率の高い、実用的な方法で生理学的宿泊施設の生体力学を模倣することです。宿泊施設は、毛様体の収縮と弛緩、チンの近見視力に必要なレンズの肥厚の結果によって実現されます。ここでは、小説、宿泊施設をレプリケートして、マニュアル レンズ担架 (MLS) を介して水晶体カプセルに接続されている zonules の緊張によって簡単な方法を提案します。このメソッドは一貫した力を受けるときのレンズにより橈骨ストレッチを監視し、ストレッチできません非対応のレンズに、伸ばすことができるレンズを収容を比較できます。重要なは、ストレッチャー カップル zonules を直接していない地球全体のサンプルではなく、レンズ、zonules、および毛様体従ってだけ必要とする、目の強膜。この違いは、地球全体の取得と比較して約 62% の死体ドナーのレンズを取得のコストを減らすことができます。

ブタ目、ストレッチ4,15、レンズによる老眼を勉強するための一般的なサンプルが得られた (n = 10) ローカル屠殺場、このプロトコルからレンズの収容能力を観察するため。図 5Aは MLS を介してストレッチの前後にブタのレンズの比較を示しています。拡大レンズの半径の平均 0.19 ± 0.07 mm 増...

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Simulating the Mechanics of Lens Accommodation via a Manual Lens Stretcher

マニュアル レンズ担架による焦点調節機構のシミュレーション

マニュアル レンズの担架を使用して焦点調節を勉強の効率的な方法を提案します。プロトコル mimics 生理宿泊施設、zonules を引いてレンズ カプセル周りにより、接続されているレンズをストレッチします。

The goal of this protocol is to mimic the biomechanics of physiological accommodation in a cost-efficient, practical manner. Accommodation is achieved ...

simulating-mechanics-lens-accommodation-via-manual-lens

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Bioengineering

6.7K ビュー.  University of Maryland. マニュアル レンズの担架を使用して焦点調節を勉強の効率的な方法を提案します。プロトコル mimics 生理宿泊施設、zonules を引いてレンズ カプセル周りにより、接続されているレンズをストレッチします。

ビデオ: Simulating the Mechanics of Lens Accommodation via a Manual Lens Stretcher

Impulsive Pressurization of Neuronal Cells for Traumatic Brain Injury Study

A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate blast-induced traumatic brain injury (TBI). We demonstrate in this video article how blast TBI-relevant impulsive pressurization is applied to the neuronal cells in vitro. This is achieved by using well-controlled pressure pulse created by a specialized Kolsky bar device, with complete pressure history within the cell pressurization chamber recorded. Pressurized neuronal cells are inspected immediately after pressurization, or further incubated to examine the long-term effects of impulsive pressurization on neurite/axonal outgrowth, neuronal gene expression, apoptosis, etc. We observed that impulsive pressurization at about 2 MPa induces distinct neurite loss relative to unpressurized cells. Our technique provides a novel method to investigate the molecular/cellular mechanisms of blast TBI, via impulsive pressurization of brain cells at well-controlled pressure magnitude and duration.

A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate the molecular/cellular mechanisms of blast-induced traumatic brain injury.

外傷性脳損傷の研究のための神経細胞のインパルス加

A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate blast-induced traumatic brain injury (TBI). ...

生物工学

Magnetic Resonance Elastography Methodology for the Evaluation of Tissue Engineered Construct Growth

Traditional mechanical testing often results in the destruction of the sample, and in the case of long term tissue engineered construct studies, the use of destructive assessment is not acceptable. A proposed alternative is the use of an imaging process called magnetic resonance elastography. Elastography is a nondestructive method for determining the engineered outcome by measuring local mechanical property values (i.e., complex shear modulus), which are essential markers for identifying the structure and functionality of a tissue. As a noninvasive means for evaluation, the monitoring of engineered constructs with imaging modalities such as magnetic resonance imaging (MRI) has seen increasing interest in the past decade1. For example, the magnetic resonance (MR) techniques of diffusion and relaxometry have been able to characterize the changes in chemical and physical properties during engineered tissue development2. The method proposed in the following protocol uses microscopic magnetic resonance elastography (&mu;MRE) as a noninvasive MR based technique for measuring the mechanical properties of small soft tissues3. MRE is achieved by coupling a sonic mechanical actuator with the tissue of interest and recording the shear wave propagation with an MR scanner4. Recently, &mu;MRE has been applied in tissue engineering to acquire essential growth information that is traditionally measured using destructive mechanical macroscopic techniques5. In the following procedure, elastography is achieved through the imaging of engineered constructs with a modified Hahn spin-echo sequence coupled with a mechanical actuator. As shown in Figure 1, the modified sequence synchronizes image acquisition with the transmission of external shear waves; subsequently, the motion is sensitized through the use of oscillating bipolar pairs. Following collection of images with positive and negative motion sensitization, complex division of the data produce a shear wave image. Then, the image is assessed using an inversion algorithm to generate a shear stiffness map6. The resulting measurements at each voxel have been shown to strongly correlate (R2&gt;0.9914) with data collected using dynamic mechanical analysis7. In this study, elastography is integrated into the tissue development process for monitoring human mesenchymal stem cell (hMSC) differentiation into adipogenic and osteogenic constructs as shown in Figure 2.

The procedure demonstrates the methodology of magnetic resonance elastography for monitoring the engineered outcome of adipose and osteogenic tissue engineered constructs through noninvasive local assessment of the mechanical properties using microscopic magnetic resonance elastography (&mu;MRE).

ティッシュエンジニアーコンストラクトの成長評価のための磁気共鳴エラストグラフィの方法論

Traditional mechanical testing often results in the destruction of the sample, and in the case of long term tissue engineered construct studies, the use ...

Monitoring the Wall Mechanics During Stent Deployment in a Vessel

Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis2-7. This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface8,9. As a mesh stent is deployed into a latex vessel with a random contrasting pattern sprayed or drawn on its outer surface, the surface strain is recorded at every instant of the deformation. The calculated strain distributions can then be used to understand the local lesion response, validate the computational models, and formulate hypotheses for further in vivo study.

Stent-induced arterial strain distributions are characterized using an optical surface strain measurement system. This visualization technique is used to gain insights into the impact of stent implantation on the host vessel.

容器内ステントの展開中の壁の力学を監視する

Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the ...

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is needed to open up the structure of the plant cell wall, increasing the accessibility of the cell wall carbohydrates. Lignin, a polyphenolic material present in many cell wall types, is known to be a significant hindrance to enzyme access. Reduction in lignin content to a level that does not interfere with the structural integrity and defense system of the plant might be a valuable step to reduce the costs of bioethanol production. In this study, we have genetically down-regulated one of the lignin biosynthesis-related genes, cinnamoyl-CoA reductase (ZmCCR1) via a double stranded RNA interference technique. The ZmCCR1_RNAi construct was integrated into the maize genome using the particle bombardment method. Transgenic maize plants grew normally as compared to the wild-type control plants without interfering with biomass growth or defense mechanisms, with the exception of displaying of brown-coloration in transgenic plants leaf mid-ribs, husks, and stems. The microscopic analyses, in conjunction with the histological assay, revealed that the leaf sclerenchyma fibers were thinned but the structure and size of other major vascular system components was not altered. The lignin content in the transgenic maize was reduced by 7-8.7%, the crystalline cellulose content was increased in response to lignin reduction, and hemicelluloses remained unchanged. The analyses may indicate that carbon flow might have been shifted from lignin biosynthesis to cellulose biosynthesis. This article delineates the procedures used to down-regulate the lignin content in maize via RNAi technology, and the cell wall compositional analyses used to verify the effect of the modifications on the cell wall structure.

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

A double stranded RNA interference (dsRNAi) technique is employed to down-regulate the maize cinnamoyl coenzyme A reductase (ZmCCR1) gene to lower plant lignin content. Lignin down-regulation from the cell wall is visualized by microscopic analyses and quantified by the Klason method. Compositional changes in hemicellulose and crystalline cellulose are analyzed.

のリグニンダウンレギュレーション<em&gt;トウモロコシ</em&gt; dsRNAiとクラソンリグニン分析によって

To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is ...

Determination of Zeta Potential via Nanoparticle Translocation Velocities through a Tunable Nanopore: Using DNA-modified Particles as an Example

Nanopore technologies, known collectively as Resistive Pulse Sensors (RPS), are being used to detect, quantify and characterize proteins, molecules and nanoparticles. Tunable resistive pulse sensing (TRPS) is a relatively recent adaptation to RPS that incorporates a tunable pore that can be altered in real time. Here, we use TRPS to monitor the translocation times of DNA-modified nanoparticles as they traverse the tunable pore membrane as a function of DNA concentration and structure (i.e., single-stranded to double-stranded DNA).
TRPS is based on two Ag/AgCl electrodes, separated by an elastomeric pore membrane that establishes a stable ionic current upon an applied electric field. Unlike various optical-based particle characterization technologies, TRPS can characterize individual particles amongst a sample population, allowing for multimodal samples to be analyzed with ease. Here, we demonstrate zeta potential measurements via particle translocation velocities of known standards and apply these to sample analyte translocation times, thus resulting in measuring the zeta potential of those analytes.
As well as acquiring mean zeta potential values, the samples are all measured using a particle-by-particle perspective exhibiting more information on a given sample through sample population distributions, for example. Of such, this method demonstrates potential within sensing applications for both medical and environmental fields.

Here we use a polyurethane tunable nanopore integrated into a resistive pulse sensing technique to characterize nanoparticles surface chemistry via the measurement of particle translocation velocities, which can be used to determine the zeta potential of individual nanoparticles.

調整可能なナノ細孔を介してナノ粒子の転ベロシティを経由してゼータ電位の決意：例として、DNA修飾された粒子を用いました

Nanopore technologies, known collectively as Resistive Pulse Sensors (RPS), are being used to detect, quantify and characterize proteins, molecules and ...

Patterning the Geometry of Human Embryonic Stem Cell Colonies on Compliant Substrates to Control Tissue-Level Mechanics

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that correspond to primary germ layer formation during embryogenesis. Thus, these cells represent a powerful tool with which to examine the mechanisms that drive early human development. We have developed a method to culture human embryonic stem cells in confined colonies on compliant substrates that provides control over both the geometry of the colonies and their mechanical environment in order to recapitulate the physical parameters that underlie embryogenesis. The key feature of this method is the ability to generate polyacrylamide hydrogels with defined patterns of extracellular matrix ligand at the surface to promote cell attachment. This is achieved by fabricating stencils with the desired geometric patterns, using these stencils to create patterns of extracellular matrix ligand on glass coverslips, and transferring these patterns to polyacrylamide hydrogels during polymerization. This method is also compatible with traction force microscopy, allowing the user to measure and map the distribution of cell-generated forces within the confined colonies. In combination with standard biochemical assays, these measurements can be used to examine the role mechanical cues play in fate specification and morphogenesis during early human development.

Extracellular matrix ligands can be patterned onto polyacrylamide hydrogels to enable the culture of human embryonic stem cells in confined colonies on compliant substrates. This method can be combined with traction force microscopy and biochemical assays to examine the interplay between tissue geometry, cell-generated forces, and fate specification.

組織レベルの力学を制御するための準拠基板上のヒト胚性幹細胞コロニーの幾何学的パターン化

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that ...

Transplantation of a 3D Bioprinted Patch in a Murine Model of Myocardial Infarction

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ligation is a challenging procedure and has a high mortality rate due to its nature. We developed a method to consistently transplant bioprinted patches of cells and hydrogels onto the epicardium of an infarcted mouse heart to test their regenerative properties in a robust and feasible way. First, a deeply anesthetized mouse is carefully intubated and ventilated. Following left lateral thoracotomy (surgical opening of the chest), the exposed LAD is permanently ligated and the bioprinted patch transplanted onto the epicardium. The mouse quickly recovers from the procedure after chest closure. The advantages of this robust and quick approach include a predicted 28-day mortality rate of up to 30% (lower than the 44% reported by other studies using a similar model of permanent LAD ligation in mice). Moreover, the approach described in this protocol is versatile and could be adapted to test bioprinted patches using different cell types or hydrogels where high numbers of animals are needed to optimally power studies. Overall, we present this as an advantageous approach which may change preclinical testing in future studies for the field of cardiac regeneration and tissue engineering.

This protocol aims to transplant a 3D bioprinted patch onto the epicardium of infarcted mice modeling heart failure. It includes details regarding anesthesia, the surgical chest opening, permanent ligation of the left anterior descending (LAD) coronary artery and application of a bioprinted patch onto the infarcted area of the heart.

心筋梗塞のマウスモデルにおける3次元バイオプリントパッチの移植

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ...

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Myosins are motor proteins that hydrolyze ATP to step along actin filament (AF) tracks and are essential in cellular processes such as motility and muscle contraction. To understand their force-generating mechanisms, myosin II has been investigated both at the single-molecule (SM) level and as teams of motors in vitro using biophysical methods such as optical trapping.
These studies showed that myosin force-generating behavior can differ greatly when moving from the single-molecule level in a three-bead arrangement to groups of motors working together on a rigid bead or coverslip surface in a gliding arrangement. However, these assay constructions do not permit evaluating the group dynamics of myosin within viscoelastic structural hierarchy as they would within a cell. We have developed a method using optical tweezers to investigate the mechanics of force generation by myosin ensembles interacting with multiple actin filaments.
These actomyosin bundles facilitate investigation in a hierarchical and compliant environment that captures motor communication and ensemble force output. The customizable nature of the assay allows for altering experimental conditions to understand how modifications to the myosin ensemble, actin filament bundle, or the surrounding environment result in differing force outputs.

Formation of actomyosin bundles in vitro and measuring myosin ensemble force generation using optical tweezers is presented and discussed.

光ピンセットを用いたアクチンフィラメント束中のミオシンアンサンブル機構の探索

Myosins are motor proteins that hydrolyze ATP to step along actin filament (AF) tracks and are essential in cellular processes such as motility and muscle ...

Chemical Triphosphorylation of Oligonucleotides

The 5&#8242;-triphosphate is an essential nucleic acid modification found throughout all life and increasingly used as a functional modification of oligonucleotides in biotechnology and synthetic biology. Oligonucleotide 5&#8242;-triphosphates have historically been prepared in vitro by enzymatic methods. However, these methods are limited to natural RNA oligonucleotides, have strong sequence preferences, and tend to produce heterogeneous products. New methods of chemical triphosphorylation complement both the reduced cost of automated oligonucleotide synthesis by phosphoramidite chemistry and the diverse range of nucleotide modifications now available. Thus, the synthesis of oligonucleotide triphosphates of arbitrary sequence and length, and optionally containing various nonnatural modifications, is now accessible.
This paper presents the appropriate methods and techniques for chemical triphosphorylation of oligonucleotides using salicyl phosphorochloridite and pyrophosphate. This method uses commercially available reagents, is compatible with most oligonucleotides prepared by standard solid-phase synthesis methods, and can be completed in 2 h following oligonucleotide synthesis, before deprotection and purification. Two uses of chemically triphosphorylated oligonucleotides as substrates for catalytic RNA enzymes are demonstrated, including the synthesis of a mirror-image version of the hammerhead ribozyme from nonbiological L-RNA triphosphates.

Oligonucleotide 5&#8242;-triphosphates are ubiquitous components in essential biological pathways and have seen increasing use in biotechnology applications. Here, we describe techniques for the routine synthesis and purification of oligonucleotide 5&#8242;-triphosphates, starting from oligonucleotides prepared by standard automated synthesis techniques.

オリゴヌクレオチドの化学的三リン酸化

The 5&#8242;-triphosphate is an essential nucleic acid modification found throughout all life and increasingly used as a functional modification of ...

Facilitating Cerebral Organoid Culture via Lateral Soft Light Illumination

At present, cerebral organoid culture technology is still complicated to operate and difficult to apply on a large scale. It is necessary to find a simple and practical solution. Therefore, a more feasible cerebral organoid protocol is proposed in the present study. To solve the unavoidable inconvenience in medium change and organoid transfer in the early stage, the current research optimizes the operation technology by applying the engineering principle. A soft light lamp was adopted to laterally illuminate the embryoid body (EB) samples, allowing the EBs to be seen by the naked eye through the enhanced diffuse reflection effect. Using the principle of secondary flow generated by rotation, the organoids gather toward the center of the well, which facilitates the operation of medium change or organoid transfer. Compared to the dispersed cell, the embryoid body settles faster in the pipette. Using this phenomenon, most of the free cells and dead cell fragments can be effectively removed in a simple way, preventing EBs from incurring damage from centrifugation. This study facilitates the operation of cerebral organoid culture and helps to promote the application of brain organoids.

Facilitating Cerebral Organoid Culture via Lateral Soft Light Illumination

Cerebral organoids provide unprecedented opportunities for studying organ development and human disease pathology. Although great success has been achieved with cerebral organoid culture systems, there are still operational difficulties in applying this technology. The present protocol describes a cerebral organoid procedure that facilitates medium change and organoid transfer.

横方向ソフトライト照明 による 大脳オルガノイド培養の促進

At present, cerebral organoid culture technology is still complicated to operate and difficult to apply on a large scale. It is necessary to find a simple ...

マニュアル レンズ担架による焦点調節機構のシミュレーション

マニュアルレンズ担架による焦点調節機構のシミュレーション