著者らは、GWバイオミメティクスバイオインスピレーション工学センターからの支援と資金援助を認めている。ジョージ・ワシントン大学生物科学科のL・パトリシア・ヘルナンデス教授は、調査にインスピレーションを与え、継続的なコラボレーションを行い、銀鯉の生理学に関する生物学的専門知識を提供し、粘液サンプルを提供してくれたことに感謝します。私たちは、デビッド・パルンボ氏、カーリー・コーエン氏、アイザック・フィンバーグ氏、ドミニク・ペトロシーノ氏、アレクシス・レンデロス氏、プリシラ・ヴァルゲーゼ氏、カーター・テゲン氏、ラガフ・パイジュル氏の研究室での支援、トーマス・エヴァンス氏とTAインスツルメンツのトーマス・エヴァンス氏とジェームズ・トーマス氏に感謝します。図5A,Cの画像は、ジョージワシントン大学生物科学科のL.パトリシア・ヘルナンデス教授が行った解剖中に撮影されました。

<ol>
	<li>Cohen, K. E., Hernandez, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+complex+trophic+anatomy+of+silver+carp,+Hypophthalmichthys+molitrix,+highlighting+a+novel+type+of+epibranchial+organ.">The complex trophic anatomy of silver carp, Hypophthalmichthys molitrix, highlighting a novel type of epibranchial organ.</a> Journal of Morphology. 279, 1615-1628 (2018).</li><li>Cohen, K. E., Hernandez, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Making+a+master+filterer:+Ontogeny+of+specialized+filtering+plates+in+silver+carp+(Hypophthalmichthys+molitrix).">Making a master filterer: Ontogeny of specialized filtering plates in silver carp (Hypophthalmichthys molitrix).</a> Journal of Morphology. 279, 925-935 (2018).</li><li>Cremer, M., Smitherman, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Food+habits+and+growth+of+silver+and+bighead+carp+in+cages+and+ponds.">Food habits and growth of silver and bighead carp in cages and ponds.</a> Aquaculture. 20 (1), 57-64 (1980).</li><li>Battonyai, I., 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=Relationship+between+gill+raker+morphology+and+feeding+habits+of+hybrid+bigheaded+carps+(Hypophthalmichthys+spp.).">Relationship between gill raker morphology and feeding habits of hybrid bigheaded carps (Hypophthalmichthys spp.).</a> Knowledge and Management of Aquatic Ecosystems. 416, 36 (2015).</li><li>Zhou, Q., Xie, P., Xu, J., Ke, Z., Guo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+food+availability+of+silver+and+bighead+carps:+Evidence+from+stable+isotope+and+gut+content+analysis.">Growth and food availability of silver and bighead carps: Evidence from stable isotope and gut content analysis.</a> Aquaculture Research. 40 (14), 1616-1625 (2009).</li><li>Freedman, J. A., Butler, S. E., Wahl, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Impacts of invasive Asian carps on native food webs (Final Report). , (2012).</li><li>Nico, L., Fuller, P., Li, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Silver carp (Hypophthalmichthys molitrix)-FactSheet. , (2017).</li><li>Walleser, L., Howard, D., Sandheinrich, M., Gaikowski, M., Amberg, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Confocal+microscopy+as+a+useful+approach+to+describe+gill+rakers+of+Asian+species+of+carp+and+native+filter-feeding+fishes+of+the+upper+Mississippi+River+system.">Confocal microscopy as a useful approach to describe gill rakers of Asian species of carp and native filter-feeding fishes of the upper Mississippi River system.</a> Journal of Fish Biology. 85 (5), 1777-1784 (2014).</li><li>Nelson, A. Z., Ewoldt, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+of+yield-stress+fluids:+a+rheology-to-structure+inverse+problem.">Design of yield-stress fluids: a rheology-to-structure inverse problem.</a> Soft Matter. 13, 7578-7594 (2017).</li><li>Chen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rheological+Techniques+for+Yield+Stress+Analysis.">Rheological Techniques for Yield Stress Analysis.</a> TA Instruments Applications Note, RH025. , (2020).</li><li>Ewoldt, R. H., Johnston, M. T., Caretta, L. M., Spagnolie, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+challenges+of+shear+rheology:+how+to+avoid+bad+data.">Experimental challenges of shear rheology: how to avoid bad data.</a> Complex Fluids in Biological Systems. , (2015).</li><li>Thornton, D. J., Sheehan, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+Mucins+to+Mucus:+Toward+a+more+coherent+understanding+of+this+essential+barrier.">From Mucins to Mucus: Toward a more coherent understanding of this essential barrier.</a> Proceedings of the American Thoracic Society. 1, 54-61 (2004).</li><li>Shepard, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functions+for+fish+mucus.">Functions for fish mucus.</a> Reviews in Fish Biology and Fisheries. 4, 401-429 (1994).</li><li>Fern&#225;ndez-Alacid, 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=Skin+mucus+metabolites+in+response+to+physiological+challenges:+A+valuable+non-invasive+method+to+study+teleost+marine+species.">Skin mucus metabolites in response to physiological challenges: A valuable non-invasive method to study teleost marine species.</a> Science of the Total Environment. 644, 1323-1335 (2018).</li><li>Wagner, C. E., Wheeler, K. M., Ribbeck, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucins+and+Their+Role+in+Shaping+the+Functions+of+Mucus+Barriers.">Mucins and Their Role in Shaping the Functions of Mucus Barriers.</a> Annual Reviews in Cell and Developmental Biology. 34, 189-215 (2018).</li><li>Bird, R. B., Armstrong, R. C., Hassager, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Dynamics of Polymeric Liquids, Volume 1: Fluid Mechanics. , 1255-1284 (1987).</li><li>Mantle, M., Allen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+characterisation+of+the+native+glycoprotein+from+pig+small+intestinal+mucus.">Isolation and characterisation of the native glycoprotein from pig small intestinal mucus.</a> Biochemical Journal. 195, 267-275 (1981).</li><li>Allen, A., Hutton, D. A., Pearson, J. P., Sellers, L. A., Nugent, J., O'Conner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucus+glycoprotein+structure,+gel+formation+and+gastrointestinal+mucus+function.">Mucus glycoprotein structure, gel formation and gastrointestinal mucus function.</a> Mucus and Mucosa (Ciba Foundation Symposium). , 137-156 (1984).</li><li>Asakawa, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histochemical+studies+of+the+mucus+on+the+epidermis+of+eel,+Anguillajaponica.">Histochemical studies of the mucus on the epidermis of eel, Anguillajaponica.</a> Bulletin of Japanese Society of Scientific Fisheries. 36, 83-87 (1970).</li><li>Fletcher, T. C., Jones, R., Reid, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+glycoproteins+in+goblet+cells+of+epidermis+and+gill+of+plaice+(Pleuroneces+platessa+L.),+flounder+(Platichthys+flesus+(L.))+and+rainbow+trout+(Salmo+gairdneri+Richardson).">Identification of glycoproteins in goblet cells of epidermis and gill of plaice (Pleuroneces platessa L.), flounder (Platichthys flesus (L.)) and rainbow trout (Salmo gairdneri Richardson).</a> Histochemical Journal. 8, 597-608 (1976).</li><li>Silberberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucus+glycoprotein,+its+biophysical+and+gel+forming+properties.">Mucus glycoprotein, its biophysical and gel forming properties.</a> Symposia of the Society for Experimental Biology. 43, 43-64 (1989).</li><li>Hills, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Biology of Surfactants. , 408 (1988).</li><li>Aubert, H., Brook, A. J., Shephard, K. L. <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+the+adhesion+of+a+desmid+to+a+substrate.">Measurement of the adhesion of a desmid to a substrate.</a> British Phycology Journal. 24, 293-295 (1989).</li><li>Sanderson, S. L., Cech, J. J., Patterson, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluid+dynamics+in+suspension+feeding+black+fish.">Fluid dynamics in suspension feeding black fish.</a> Science. 251, 1346-1348 (1991).</li><li>Lai, S. K., Wang, Y. Y., Wirtz, D., Hanes, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro-+and+macrorheology+of+mucus.">Micro- and macrorheology of mucus.</a> Advanced Drug Delivery Reviews. 61 (2), 86-100 (2009).</li><li>Chaudhary, G., Ewoldt, R. H., Thiffeault, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unravelling+hagfish+slime.">Unravelling hagfish slime.</a> Journal of Royal Society Interface. 16 (150), 20180710 (2019).</li><li>Downing, S., Salo, W., Spitzer, R., Koch, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+hagfish+slime+gland:+a+model+system+for+studying+the+biology+of+mucus.">The hagfish slime gland: a model system for studying the biology of mucus.</a> Science. 214, 1143-1145 (1981).</li><li>Hwang, S. H., Litt, M., Forsman, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rheological+properties+of+mucus.">Rheological properties of mucus.</a> Rheologica Acta. 8, 438-448 (1969).</li><li>Litt, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucus+rheology.">Mucus rheology.</a> Archives of Internal Medicine. 126, 417-423 (1970).</li><li>Quarishi, M. S., Jones, N. S., Mason, 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+rheology+of+nasal+mucus:+a+review.">The rheology of nasal mucus: a review.</a> Clinical Otolaryngology. 23, 403-413 (1998).</li><li>Nordg&#229;rd, C. T., Draget, K. I., Seternes, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rheology+of+salmon+skin+mucus.">Rheology of salmon skin mucus.</a> Annual Transactions - The Nordic Rheology Society. 23, 175-179 (2015).</li><li>Fern&#225;ndez-Alacid, 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=Comparison+between+properties+of+dorsal+and+ventral+skin+mucus+in+Senegalese+sole:+Response+to+an+acute+stress.">Comparison between properties of dorsal and ventral skin mucus in Senegalese sole: Response to an acute stress.</a> Aquaculture. 513, 734410 (2019).</li><li>Y&#252;ce, C., Willenbacher, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Challenges+in+Rheological+Characterization+of+Highly+Concentrated+Suspensions+-+Case+Study+for+Screen-printing+Silver+Pastes.">Challenges in Rheological Characterization of Highly Concentrated Suspensions - Case Study for Screen-printing Silver Pastes.</a> Journal of Visualized Experiments. (122), e55377 (2017).</li><li>Sultan, S., Mathew, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+Printed+Porous+Cellulose+Nanocomposite+Hydrogel+Scaffolds.">3D Printed Porous Cellulose Nanocomposite Hydrogel Scaffolds.</a> J. Vis. Exp. (146), (2019).</li><li>Barnes, H. A., Hutton, J. F., Walters, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> An Introduction to Rheology. , (1989).</li><li>USGS Current Conditions for USGS 06910450 Missouri River at Jefferson City, MO. U.S. Geological Survey Available from: <a target="_blank" href="https://nwis.waterdata.usgs.gov/usa/nwis/uv/?cb_00010=on&amp;cb_00060=on&amp;cb_00065=on&amp;format=gif_default&amp;site_no=0691045&amp;p09-19&amp;end_date=2018-09-21">https://nwis.waterdata.usgs.gov/usa/nwis/uv/?cb_00010=on&amp;cb_00060=on&amp;cb_00065=on&amp;format=gif_default&amp;site_no=0691045&amp;p09-19&amp;end_date=2018-09-21</a> (2020)</li></ol>

利益相反は宣言されていません。

このプロトコルを開発する主な目的の1つは、非常に小さなサンプル量が利用可能な場合にGR粘液のレオロジー特性に適していることを確立することです。我々は、GR粘液のレオロジー特性を完全に特徴付けるために銀鯉の群れからのより多くのサンプルが必要であり、ここに提示されるデータは銀鯉の集団全体の一般化ではないことを認める。我々の技術は、少量のサンプルのレオロジー特?...

銀の鯉、眼圧性モリトリックスは、プランクチボラスフィルターフィーダーであり、米国のいくつかの自然水路に浸透している侵略的な種です。この種は、最初は藻類の花1、2、3を制御するために、ミシシッピ川の上流域で導入されました。銀の鯉は非常に有効なフィーダーである。通常、その消耗品の粒子サイズは4〜20μmから約80μm3、4、5の大きな動物プランクトンまで及ぶ。この種は他の在来魚と競合しており、利用可能な資源1、2、6を制限することで、ネイティブの水路に甚大な被害を与える可能性があります。したがって、銀の鯉や大きな頭の鯉などの魚を餌にするフィルターは、五大湖1、2、6、7、8に大きな脅威を与えます。
魚の餌付けフィルターは、その表面に存在する粘液の薄い層を持つギルレーカー(RS)と呼ばれる特別な器官を持っています。これらの器官は入ってくる液体からの小さい粒子のろ過および凝集の効率を改善する。本明細書に提示されるプロトコルの目標は、銀の鯉の中のギルレーカーの内面から取得した非ニュートン、剪断間薄化材料特性および降伏応力を特徴付ける。GR粘液の降伏応力の値は、回転式の表現力計を用いて確認され、この研究で注目されている。測定された降伏応力は、「見かけの降伏応力」とも呼ばれ、定常せん断速度や動的振動歪型タイプ9、10などの試験方法に依存します。せん断間化の「降伏応力流体」は、重要な加重応力9,11において固体状から液体様の挙動への移行を受ける。見かけの降伏応力は、流れを開始するために必要な最小せん断応力、または粘液がゲル状の材料から流体状の材料に移行するときに、不可逆的な塑性変形が最初に観察される最小せん断応力です。この挙動は、構造化粘弾性材料で観察することができます。GR粘液のゲル状から流体状の挙動への移行には、食品微粒子を収集する接着的役割と、粒子状の送達および濾過プロセスを支援する輸送車両の役割の2つの機能が必要です。粘液の拡張機能は、疾患耐性および呼吸における拡散障壁の作成、栄養因子の制御放出、毒性成分および排泄の制御放出、摂食および入れ子のための代謝経路の作成、捕食者保護の支援、および移動および推進効率12、13、14を改善する境界層改変を生み出すことである。
単純な流体とは異なり、粘液のような複雑な流体は、流れの条件によって異なる特性を持ち、バルクスケールの物理的挙動を定義するために追加の測定パラメータを必要とします。GR粘液の粘度と降伏応力を監視するために、回転レオメーターを使用してレオロジー測定を行います。回転式の回転計は、流体サンプルに接触する回転ディスクを使用して、安定したまたは振動性のせん断応力または歪みを適用し、その応答を測定します。この装置と技術を使用する背後にある根拠は、この測定器は、密度だけでは定義できない銀の鯉のGR粘液の材料特性を記述するための一連の測定値を提供することができるということです。
粘液は粘弾性材料であり、強制変形に対する機械的反応は、純粋な固体(フックの弾性法則によって支配される)と純粋な液体(ニュートンの粘性法則によって支配される)の間にある15,16である。粘液内に含まれる複雑な高分子ネットワークは、外力や変形に応じて伸縮し、方向を変えることができます。回転式の回転計は、図 1と図 2に示すように、円錐形状とペルチェプレートで構成されます (計測仕様については表1を参照)。本研究の目的は、GR粘液のレオロジー特性を決定するプロトコルを開発することであった。粘度計よりも回転式の回転計の利点は、少量のサンプルを使用して動的測定を行う能力です。この研究におけるGR粘液サンプル容積は約1.4mLであった。一方、粘度計は一定のせん断速度に制限されており、大量のサンプルを必要とします。
粘液のレオロジー特性は、銀の鯉の解剖学内で大きく変化することが期待される。例えば、GR表面に存在する粘液の特性は、エピブランチ器官と異なってもよい。魚の異なる領域における粘液特性の潜在的な変動性を考慮して、獲得したGR粘液サンプルを希釈し、回転リオメーターを用いて3つの濃度の溶液を作成し、試験した。プロトコルを実行した後に報告された粘液の変性に関するデータと結果は、測定技術の有効性を示した。この論文で示す例示的なデータは、銀の鯉の集団全体にわたって一般化されることを意図したものではありません。本明細書に提示されるプロトコルは、他の仮説をテストするために、より大きなサンプルセットにわたる粘液学を調査するために拡張することができる。
本研究の目的は、3つの異なる粘液濃度(400mg/mL、200mg/mLおよび100mg/mL)を有するGR粘液学のレオロジー特性の変動を実証することにある。400mg/mL濃度は、魚グラムから採取した生粘液サンプルを表し、除イオン水(DI)を使用して、生の粘液サンプルを200mg/mLおよび100mg/mL濃度に希釈した。粘液サンプルを希釈することで、濃度の関数としての剪断薄化および明らかな収量応力の評価と、GR粘液が非ニュートン行動に移行する濃度の決定が可能となった。シェーカーは、不均一性によるレオロジーデータの誤差を軽減するために、サンプル内の粘液の大きな塊を分解するために使用されました。
魚を含むほとんどの脊椎動物において、主な粘液形成高分子は、絡み合いや化学的架橋によって水中に膨れ込み、ゲル状物質12、13、17、18、19、20を生成する傾向がある糖タンパク質(ムチン)である。高分子、ゲル形成高分子および高含水率は、粘液13における滑りやすさを反映する。高い高い高分子間相互作用はゲル形成をもたらすが、高分子間相互作用または結合の崩壊のレベルが低いと、高粘度流体21が得られる。
魚を供給するフィルターにおける食品微粒子濾過のプロセスは、接着性およびタック22の可能性を決定する凝集および粘度などのGR粘液関連の特性によって助けられている。粘液ベースの接着の強さは、特定の分子間、静電または疎水性相互作用23に依存する。サンダーソンら24 は、粘液ベースの接着の証拠を発見したブラックフィッシュで懸濁液試験を行った。彼らは、粘膜表面を有する浮遊食品微粒子の接着が続いて、それに作用する指向水流によって粘液と結合した粒子の凝集塊の輸送が続くと述べた。水流から発生するせん断ひずみ速度にさらされた粘液は、食物粒子を消化器官に送り込むのを促進する。内視鏡的手法は、ろ過粒子24を観察するために用いた。
GR粘液のレオロジー検査におけるせん断速度と実用的限界の範囲に関する文献は乏しい。そこで、胃、鼻、子宮頸管および肺粘液、サケの皮膚粘液、ハグフィッシュスライム、および骨関節表面潤滑剤に関するレオロジー研究から指導を求め、その後、レオロジー特性と非ニュートン属性を11、12、25、26、27、28、29、30、31に求めた。最近では、魚の皮膚粘液が移動や推進効率に及ぼす影響を、一定のせん断速度粘度測定を用いて検討されている。シーブリーム、シーバスおよびミーグレに関する皮膚粘液の分析研究(希釈または均質化なし)は、典型的には低い剪断速度14で非ニュートンの挙動を示した。 別の関連研究では、セネガルソールの側側および腹側からの生の皮膚粘液サンプルは、非ニュートン的な挙動を示すことが判明し、32と考えられるすべてのせん断速度で腹側粘液のより高い粘度を示した。ヒドロゲル足場の発達に関する他のレオロジープロトコルおよび一定の剪断速度粘度計を用いた高濃度懸濁液についても文献33,34に報告されている。
本研究では、GR粘液特性を、複雑な生体流体25に対する流動学実験で広く使用されている歪速度制御、回転式流動計を用いて調べた。ニュートン流体の場合、見かけの粘度は一定のままで、せん断速度に依存しない、せん断応力はせん断応力率で線形に変化する(図3A、B)。非ニュートン流体(剪断間薄化流体など)の粘度は、せん断速度依存または変形履歴依存である(図3A、B)。損失係数(G")は、材料が流れる傾向に抵抗する程度を表し、流体粘度を表す(図4)。貯蔵弾性率(G')は、応力によって引き起こされた変形に続いて元の形状を回復する材料の傾向を表し、弾性に相当する(図4)。位相角度(δ)または損失接線値は、G"/G'の逆正接から計算されます。これは、エネルギー損失と貯蔵のバランスを表し、粘弾性材料(δ =フック固体の場合は0°、粘性液体の場合はδ=90°、粘弾性固体の場合はδ <45°、粘弾性液体の場合は45°をδ >)を特徴付けるための一般的なパラメータでもあります(図4)25。構造化流体における見かけの降伏応力(σ y)は、定常状態スイープおよび動的応力歪スイープ10からのレオロジーデータで観察できる状態の変化を表す。外部適用応力が見かけの降伏応力よりも小さい場合、材料は弾性的に変形します。応力が見かけの降伏応力(図3Bで「平均応力」としてマーク)を超えると、材料は弾性から塑性変形に移行し、液体状態35で流れ始める。振動応力(または歪み)条件下での粘液サンプルの貯蔵弾性率(G')と損失率(G")を測定すると、ゲル状から粘弾性性の液体状の挙動に物質状態の変化を定量化します。
貯蔵弾性率(G')、損失率(G")および見かけの粘度(η)に関するデータを監視するために実行されるレオメータ試験の種類をここに説明します。ダイナミック振動試験(歪みスイープと周波数スイープ)は、コーンジオメトリの制御された振動の下でG'とG"を監視しました。動的歪みスイープ試験では、固有の材料応答を監視することによって粘液の線形粘弾性領域(LVR)を決定した(図4)。歪みスイープは、一定の振動周波数と温度での降伏動作を決定するために使用されました。動的周波数スイープテストでは、一定の振幅(ひずみまたは応力)と温度での周波数の増加(変形率)に対する材料の応答を監視しました。ひずみは、動的周波数スイープ試験のために線形粘弾性領域(LVR)で維持された。定常せん断率テストでは、コーンジオメトリの安定した回転下での見かけの粘度(η)を監視しました。GR粘液を段階的な応力ステップを行い、見かけの粘度(η、Pa.s)を、せん断速度(ý,1/s)の変化をモニタリングした。
本論文では、GR粘液を、ある線形粘弾性応答範囲を持つ未知の粘弾性の複雑な構造化材料として扱う。魚の粘液は、L.パトリシア・ヘルナンデス教授(ジョージワシントン大学生物科学科)によってミズーリ川のハートクリークの場所での釣り遠征中に銀の鯉のDRから抽出されました1,2,36. Silver 鯉の口の中にある一連の GRs を図 5Aに示し、図5Bに概略図を示します。切除された GR を図5Cに示します。 銀色の鯉のGRsからの粘液の抽出は、図5D、図5D、Eの図の一例として提示される。すべてのレオメータ試験は、22±0.002°Cの一定の制御温度で行われ、漁場1、2、36で記録された温度。 各粘液サンプルを、その測定結果を3回測定し、平均結果を統計的誤差棒と共に提示した。

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		<tr height="21">
			<td height="21" style="height:21px;width:191px;">Materials</td>
			<td style="width:245px;"></td>
			<td style="width:191px;"></td>
			<td style="width:261px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Kim Wipes</td>
			<td style="width:245px;">VWR</td>
			<td style="width:191px;">470224-038</td>
			<td style="width:261px;">To clean Sample from plate</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Gloves</td>
			<td style="width:245px;">VWR</td>
			<td style="width:191px;">89428-750</td>
			<td style="width:261px;">To prevent contamination of sample</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:191px;">Pipette</td>
			<td style="width:245px;">VWR</td>
			<td style="width:191px;">89079-974</td>
			<td style="width:261px;">To transport sample from vial to rheometer</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:191px;">Pipette Tips</td>
			<td style="width:245px;">Thermo Scientific</td>
			<td style="width:191px;">72830-042</td>
			<td style="width:261px;">To transport sample from vial to rheometer</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:191px;">Shaker</td>
			<td style="width:245px;">VWR</td>
			<td style="width:191px;">89032-094</td>
			<td style="width:261px;">To homogenously mix sample of mucus</td>
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		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Vials</td>
			<td style="width:245px;">VWR</td>
			<td style="width:191px;">66008-710</td>
			<td style="width:261px;">Contains measured sample volumes</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Weigh Scale</td>
			<td style="width:245px;">Ohaus</td>
			<td style="width:191px;">Scout &#8211;SPX Balances</td>
			<td style="width:261px;">To weigh mass of mucus samples</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Chemical Reagents</td>
			<td></td>
			<td></td>
			<td></td>
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		<tr height="41">
			<td height="41" style="height:41px;width:191px;">De-Ionized Water (H20)</td>
			<td style="width:245px;">-</td>
			<td style="width:191px;">-</td>
			<td style="width:261px;">Liquid</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:191px;">Sterile 70% Isopropanol (C3H8O)</td>
			<td style="width:245px;">VWR</td>
			<td style="width:191px;">89108-162</td>
			<td style="width:261px;">Liquid</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">GR Mucus</td>
			<td></td>
			<td></td>
			<td></td>
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		<tr height="41">
			<td height="41" style="height:41px;width:191px;">100 mg/mL concentration, 2mL</td>
			<td style="width:245px;">-</td>
			<td style="width:191px;">-</td>
			<td style="width:261px;">Viscoelastic Material</td>
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		<tr height="41">
			<td height="41" style="height:41px;width:191px;">400 mg/mL concentration, 1mL</td>
			<td style="width:245px;">-</td>
			<td style="width:191px;">-</td>
			<td style="width:261px;">Viscoelastic Material</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:191px;">200 mg/mL concentration, 1mL</td>
			<td style="width:245px;">-</td>
			<td style="width:191px;">-</td>
			<td style="width:261px;">Viscoelastic Material</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:191px;">Software</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:191px;">MATLAB</td>
			<td style="width:245px;">Mathworks</td>
			<td style="width:191px;">R2017a</td>
			<td style="width:261px;">Data analysis, post-processing and graphical representation</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:191px;">Trios</td>
			<td>TA Instruments</td>
			<td style="width:191px;">v4.5.042498</td>
			<td style="width:261px;">Rheometer instrument control and analysis software</td>
		</tr>
	</tbody>
</table>

macro-rheology characterization of gill raker mucus in the silver carp, hypophthalmichthys molitrix

銀の鯉 、眼圧動性モリトリクスは、その非常に効率的なフィルター供給機構のために、ミシシッピ川の上流域の自然の水路がはびこる侵襲的なプランクチボラスフィルターフィーダー魚です。ギルレーカー(DR)と呼ばれる特徴的な器官は、多くのそのようなフィルターフィーダーに見られる、数ミクロンの大きさの植物プランクトンのような食品粒子の効率的なろ過を促進する。
GR粘液のレオロジーを調査する動機は、銀の鯉のフィルター供給プロセスを支援する役割を理解したいという私たちの願望に由来します。粘液が豊富な流体は、「厚くて粘着性のある」状態で、食品微粒子の付着を促進し得る。GR膜を通る浸透および輸送は、様々なせん断歪速度を誘発する外部せん断力の作用によって促進される。したがって、粘液の手引きは、魚を供給するフィルターのプール内の銀の鯉の驚異的な競争の性質に重要な手がかりを提供することができます。これに基づいて、GR粘液は、食品粒子に接着機能を提供し、フィルター供給プロセスを支援する輸送手段として作用し得ることを示唆した。
プロトコルの主な目的は、粘液の降伏応力を決定することです, 不可逆塑性変形が構造化された粘弾性材料を介して最初に観察される流れを開始するために必要な最小せん断応力に起因します.従って、GR粘液のレオロジー特性、すなわち、粘度、貯蔵、および損失モジュライは、回転レオメータを用いてその非ニュートン、剪断薄膜性について調べた。
ここで提示されたプロトコルは、ミズーリ川のハートクリークの場所で釣られた銀鯉のギルレーカーから抽出された粘液のレオロジー特性を分析するために使用されます。このプロトコルは、構造粘弾性材料と想定される粘液のレオロジー試験および物質的特性化のための効果的な戦略を開発することを目的としています。

このセクションでは、円錐形状(直径40mm、1°0'11')とペルチェプレートを持つ回転式流圧計を用いたGR粘液の実験結果を紹介します。実験は、GR粘液の非ニュートン、せん断間の挙動と、ゲル状物質から流体状の材料への粘液の移行を表す明らかな収量応力を特徴付けるのに役立った。代表的な結果は、低トルク限界と回転式流量計の二次流れ効果の定量的記述を伴う。計測限界と定常および動?...

Watch this Scientific Journal Video about Macro-Rheology Characterization of Gill Raker Mucus in the Silver Carp, Hypophthalmichthys molitrix at JoVE.com

Macro-Rheology Characterization of Gill Raker Mucus in the Silver Carp, Hypophthalmichthys molitrix

このプロトコルは、銀の鯉のギルレーカー(の)上に存在する粘液のレガロジー特性を実行する方法を提示します。粘度、保存および損失モジュライを測定して得られるGR粘液の粘弾性特性は、見かけの収量応力について評価され、GRにおけるフィルタ供給機構を理解する。

銀の鯉、眼圧軟化モリクスにおけるギル・レイカー粘液のマクロ・レオロジー特性

The silver carp, Hypophthalmichthys molitrix, is an invasive planktivorous filter feeder fish that infested the natural waterways of the upper Mississippi ...

macro-rheology-characterization-gill-raker-mucus-silver-carp

Research

JoVE Journal

Engineering

Macro-Rheology Characterization of Gill Raker Mucus in the Silver Carp, Hypophthalmichthys molitrix

3.0K ビュー.  The George Washington University. このプロトコルは、銀の鯉のギルレーカー(の)上に存在する粘液のレガロジー特性を実行する方法を提示します。粘度、保存および損失モジュライを測定して得られるGR粘液の粘弾性特性は、見かけの収量応力について評価され、GRにおけるフィルタ供給機構を理解する。

ビデオ: Macro-Rheology Characterization of Gill Raker Mucus in the Silver Carp, Hypophthalmichthys molitrix

A Method to Fabricate Disconnected Silver Nanostructures in 3D

The standard nanofabrication toolkit includes techniques primarily aimed at creating 2D patterns in dielectric media. Creating metal patterns on a submicron scale requires a combination of nanofabrication tools and several material processing steps. For example, steps to create planar metal structures using ultraviolet photolithography and electron-beam lithography can include sample exposure, sample development, metal deposition, and metal liftoff. To create 3D metal structures, the sequence is repeated multiple times. The complexity and difficulty of stacking and aligning multiple layers limits practical implementations of 3D metal structuring using standard nanofabrication tools. Femtosecond-laser direct-writing has emerged as a pre-eminent technique for 3D nanofabrication.1,2 Femtosecond lasers are frequently used to create 3D patterns in polymers and glasses.3-7 However, 3D metal direct-writing remains a challenge. Here, we describe a method to fabricate silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm. The method enables the fabrication of patterns not feasible using other techniques, such as 3D arrays of disconnected silver voxels.8 Disconnected 3D metal patterns are useful for metamaterials where unit cells are not in contact with each other,9 such as coupled metal dot10,11or coupled metal rod12,13 resonators. Potential applications include negative index metamaterials, invisibility cloaks, and perfect lenses.
In femtosecond-laser direct-writing, the laser wavelength is chosen such that photons are not linearly absorbed in the target medium. When the laser pulse duration is compressed to the femtosecond time scale and the radiation is tightly focused inside the target, the extremely high intensity induces nonlinear absorption. Multiple photons are absorbed simultaneously to cause electronic transitions that lead to material modification within the focused region. Using this approach, one can form structures in the bulk of a material rather than on its surface.
Most work on 3D direct metal writing has focused on creating self-supported metal structures.14-16 The method described here yields sub-micrometer silver structures that do not need to be self-supported because they are embedded inside a matrix. A doped polymer matrix is prepared using a mixture of silver nitrate (AgNO3), polyvinylpyrrolidone (PVP) and water (H2O). Samples are then patterned by irradiation with an 11-MHz femtosecond laser producing 50-fs pulses. During irradiation, photoreduction of silver ions is induced through nonlinear absorption, creating an aggregate of silver nanoparticles in the focal region. Using this approach we create silver patterns embedded in a doped PVP matrix. Adding 3D translation of the sample extends the patterning to three dimensions.

Femtosecond-laser direct-writing is frequently used to create three-dimensional (3D) patterns in polymers and glasses. However, patterning metals in 3D remains a challenge. We describe a method for fabricating silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm.

3Dで切断された銀ナノ構造体を製造する方法

The standard nanofabrication toolkit includes  techniques primarily aimed at creating 2D patterns in dielectric media. Creating  metal patterns on a ...

工学

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

Construction and Characterization of External Cavity Diode Lasers for Atomic Physics

Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and Titanium Sapphire lasers as the workhorse laser of atomic physics labs1,2. Their versatility and prolific use throughout atomic physics in applications such as absorption spectroscopy and laser cooling1,2 makes it imperative for incoming students to gain a firm practical understanding of these lasers. This publication builds upon the seminal work by Wieman3, updating components, and providing a video tutorial. The setup, frequency locking and performance characterization of an ECDL will be described. Discussion of component selection and proper mounting of both diodes and gratings, the factors affecting mode selection within the cavity, proper alignment for optimal external feedback, optics setup for coarse and fine frequency sensitive measurements, a brief overview of laser locking techniques, and laser linewidth measurements are included.

This is an instructional paper to guide the construction and diagnostics of external cavity diode lasers (ECDLs), including component selection and optical alignment, as well as the basics of frequency reference spectroscopy and laser linewidth measurements for applications in the field of atomic physics.

原子物理学外部共振器半導体レーザーの構築とキャラクタリゼーション

Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and ...

Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via stereotactic radiotherapy where positioning accuracy allows delivering very high doses per fraction in a small volume of the patient. Dosimetric measurements on medical accelerators are conventionally realized using air-filled ionization chambers. However, in small beams these are subject to nonnegligible perturbation effects. This study focuses on liquid ionization chambers, which offer advantages in terms of spatial resolution and low fluence perturbation. Ion recombination effects are investigated for the microLion detector (PTW) used with the Cyberknife system (Accuray). The method consists of performing a series of water tank measurements at different source-surface distances, and applying corrections to the liquid detector readings based on simultaneous gaseous detector measurements. This approach facilitates isolating the recombination effects arising from the high density of the liquid sensitive medium and obtaining correction factors to apply to the detector readings. The main difficulty resides in achieving a sufficient level of accuracy in the setup to be able to detect small changes in the chamber response.

A growing number of radiation therapy devices offer the advantage of delivering the dose through very small beams to the tumor, allowing for increased conformity and higher doses per fraction. Many different detectors can be used for the dosimetry of these small fields. In the present study, the effect of ion recombination is investigated for a liquid ionization chamber using a stereotactic radiation therapy system.

放射線外科アクセラレータの線量測定に使用される液体電離箱における再結合効果の特性評価

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via ...

Patterning via Optical Saturable Transitions - Fabrication and Characterization

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical Saturable Transitions (POST). In this technique the chemical properties of organic photochromic molecules that undergo single-photon reactions are exploited, enabling rapid top-down nanopatterning over large areas at low light intensities, thereby, allowing for the circumvention of the far-field diffraction barrier.4 Simple, cost-effective, high throughput and resolution alternatives to nanopatterning are being explored, such as, two-photon polymerization5,6, beam pen lithography (BPL)7, scanning electron beam lithography (SEBL), and focused ion beam (FIB) patterning. However, multi-photon approaches require high light intensities, which limit their potential for high throughput and offer low image contrast. Although, electron and ion beam lithographic processes offer increased resolution, the serial nature of the process is limited to slow writing speeds, which also prevents patterning of features over large areas. Beam-pen lithography is an approach towards parallel near-field optical lithography. However, the gap between the source of the beam and the surface of the photoresist needs to be controlled extremely precisely for good pattern uniformity and this is very challenging to accomplish for large arrays of beams. Patterning via Optical Saturable Transitions (POST) is an alternative optical nanopatterning technique for patterning sub-wavelength features1-3. Since this technique uses single photons instead of electrons, it is extremely fast and does not require high light intensities1-3, opening the door to massive parallelization.

We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.

光可飽和遷移を経由してパターニング - 作製と特性評価

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical ...

Electron Channeling Contrast Imaging for Rapid III-V Heteroepitaxial Characterization

Misfit dislocations in heteroepitaxial layers of GaP grown on Si(001) substrates are characterized through use of electron channeling contrast imaging (ECCI) in a scanning electron microscope (SEM). ECCI allows for imaging of defects and crystallographic features under specific diffraction conditions, similar to that possible via plan-view transmission electron microscopy (PV-TEM). A particular advantage of the ECCI technique is that it requires little to no sample preparation, and indeed can use large area, as-produced samples, making it a considerably higher throughput characterization method than TEM. Similar to TEM, different diffraction conditions can be obtained with ECCI by tilting and rotating the sample in the SEM. This capability enables the selective imaging of specific defects, such as misfit dislocations at the GaP/Si interface, with high contrast levels, which are determined by the standard invisibility criteria. An example application of this technique is described wherein ECCI imaging is used to determine the critical thickness for dislocation nucleation for GaP-on-Si by imaging a range of samples with various GaP epilayer thicknesses. Examples of ECCI micrographs of additional defect types, including threading dislocations and a stacking fault, are provided as demonstration of its broad, TEM-like applicability. Ultimately, the combination of TEM-like capabilities &#8211; high spatial resolution and richness of microstructural data &#8211; with the convenience and speed of SEM, position ECCI as a powerful tool for the rapid characterization of crystalline materials.

The use of electron channeling contrast imaging in a scanning electron microscope to characterize defects in III-V/Si heteroexpitaxial thin films is described. This method yields similar results to plan-view transmission electron microscopy, but in significantly less time due to lack of required sample preparation.

迅速なIII-Vヘテロ特徴付けのための電子チャネリングコントラストイメージング

Misfit dislocations in heteroepitaxial layers of GaP grown on Si(001) substrates are characterized through use of electron channeling contrast imaging ...

Integration of Light Trapping Silver Nanostructures in Hydrogenated Microcrystalline Silicon Solar Cells by Transfer Printing

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly known as plasmonic effects, play an important role. Research in this field has, however, been impeded owing to the difficulty of fabricating devices containing the desired functional metal nanostructures. In order to provide a viable strategy to this issue, we herein show a transfer printing-based approach that allows the quick and low-cost integration of designed metal nanostructures with a variety of device architectures, including solar cells. Nanopillar poly(dimethylsiloxane) (PDMS) stamps were fabricated from a commercially available nanohole plastic film as a master mold. On this nanopatterned PDMS stamps, Ag films were deposited, which were then transfer-printed onto block copolymer (binding layer)-coated hydrogenated microcrystalline Si (&#181;c-Si:H) surface to afford ordered Ag nanodisk structures. It was confirmed that the resulting Ag nanodisk-incorporated &#181;c-Si:H solar cells show higher performances compared to a cell without the transfer-printed Ag nanodisks, thanks to plasmonic light trapping effect derived from the Ag nanodisks. Because of the simplicity and versatility, further device application would also be feasible thorough this approach.

A viable transfer printing-based methodology to introduce plasmonic metal nanostructures in solar cells is described. Using nanopillar poly(dimethylsiloxane) stamps, an Ag-based ordered nanodisk array was integrated with standard hydrogenated microcrystalline Si solar cells, which led to improved device performances due to plasmonic light trapping.

転写印刷により水素化微結晶シリコン太陽電池の光トラッピング銀ナノ構造の統合

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly ...

Production of Synthetic Nuclear Melt Glass

Realistic surrogate nuclear debris is needed within the nuclear forensics community to test and validate post-detonation analysis techniques. Here we outline a novel process for producing bulk surface debris using a high temperature furnace. The material developed in this study is physically and chemically similar to trinitite (the melt glass produced by the first nuclear test). This synthetic nuclear melt glass is assumed to be similar to the vitrified material produced near the epicenter (ground zero) of any surface nuclear detonation in a desert environment. The process outlined here can be applied to produce other types of nuclear melt glass including that likely to be formed in an urban environment. This can be accomplished by simply modifying the precursor matrix to which this production process is applied. The melt glass produced in this study has been analyzed and compared to trinitite, revealing a comparable crystalline morphology, physical structure, void fraction, and chemical composition.

A protocol for the production of synthetic nuclear melt glass, similar to trinitite, is presented.

合成核メルトガラスの製造

Realistic surrogate nuclear debris is needed within the nuclear forensics community to test and validate post-detonation analysis techniques. Here we ...

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of stretchable electronic devices is the preparation of stretchable conductors with great mechanical stability. In this study, we developed a simple fabrication method to chemically solder the contact points between silver nanowire (AgNW) networks. AgNW nanomesh was first deposited on a glass slide via spray coating method. A reactive ink composed of silver nanoparticle (AgNPs) precursors was applied over the spray coated AgNW thin films. After heating for 40 min, AgNPs were preferentially generated over the nanowire junctions to solder the AgNW nanomesh, and reinforced the conducting network. The chemically modified AgNW thin film was then transferred to polyurethane (PU) substrates by casting method. The soldered AgNW thin films on PU exhibited no obvious change in electrical conductivity under stretching or rolling process with elongation strains up to 120%.

A simple synthesis method is used to chemically solder silver nanowire thin film to fabricate highly stretchable and conductive metal conductors.

シルバーナノワイヤーと伸縮性の高い導体の製造方法

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

高度に濃縮された懸濁液のレオロジー特性評価における課題 - スクリーン印刷シルバーペーストのためのケーススタディ

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...