This work was supported by the BOF grant for SG from Ghent University. AL is supported by the Rutgers University NSF Fuels-IGERT. SA is supported by the European Union Framework Programme 7 project &#8220;ProEthanol 2G.&#8221; SA and KR are supported by Ghent University Multidisciplinary Research Partnership (MRP)&#8212;Biotechnology for a sustainable economy (01 MRA 510W). JD is supported by an IOF Advanced grant (F2012/IOF-Advanced/094). KR is supported by by the ERC Starter Grant &#8220;Electrotalk&#8221;. The authors thank Tim Lacoere for designing the TOC art figure, Robin Declerck for building the strip and absorption columns and Kun Guo for providing the inoculum source.

<ol>
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The authors have nothing to disclose.

この原稿は、アンモニウム回復のための生物電気化学および電気化学セルを設定するために必要なツールを提供します。結果のセクションで提示計算は、システムの性能を評価するためのパラメータを提供する。生物学的および電気化学システムは、セットアップおよび機能において類似している。二つのシステムの主な違いは、生物電気化学セットアップのための固定アノード電位に対し?...

排水·ゲインの重要性から価値ある製品の回収貴重な資源が回復せずに乏しいと治療になるとだけコストを表しています。廃水を回収することができる両方のエネルギーと栄養素を含み、栄養回復が生産ループ1を閉じるのを助けることができる。栄養素の回復はあまり一般的ではないながら、嫌気性消化によるエネルギーの回収は、十分に確立されたプロセスである。尿や肥料などの液体廃棄物の流れからの栄養分の回復が広くスツルバイトアンモニア2,3の直接のストリッピングの生産を通して、 例えば 、検討されている。しかしながら、化学添加の必要性は、これらのプロセス4の欠点がある。ここでは、カリウム及びアンモニウムの両方を含む廃棄物の流れからのカチオン性栄養素の回収のための手法を提示する。これらの栄養素のカチオン形態は、電気化学システムにおけるイオン選択性膜を使用して回収を可能にする。この場合、electrochemicらのシステムは（酸化が起こる）陽極室から成る、（還元が起こる）陰極室と区画を分離するためのイオン選択膜。電圧は、アノードからカソードへの電流の流れを生成するために、セルの両端に印加される。この電圧は、水の酸化還元反応を駆動するために外部電源によって生成することができる。代替的に、陽極酸化は、 例えば 、有機物の、より少ない電力を必要とする、電気細菌によって触媒され得る。回路を閉じて、電荷バランスを維持するために、荷電種は、生成された各電子のための電極の間に移行する必要があります。陽イオン交換膜（CEM）全体の陰極室に陽極室からアンモニウム輸送は、このように電子が4,5のフラックスを補償することができる。 ここで紹介するテクニックだけでなく、廃棄物の流れからアンモニアを削除するだけでなく、そのリカバリを可能にします。総アンモニア態窒素（TAN）は、両方のアモンの平衡状態で存在するイウム（NH 4 +）およびアンモニア（NH 3）、そしてpHおよび温度6に依存する。 NH 4 +は、陽極室に高いTAN濃度にし、pHが中性付近に豊富に入手可能であり、この正に帯電した種は、従って、陰極室にCEM横切る電流で駆動することができる。電流は、水酸化物イオンおよび水素ガスの産生をもたらす、カソードにおける水の還元を駆動する。 TAN平衡に起因陰極室（&gt; 10.0）で高いpHにほぼ100％のNH 3に移行する。 NH 3を簡単には、酸溶液中で捕捉され、集中して吸収塔に、ストリッピングユニットからの空気の循環を介して転送することができるガスである。 この技術は、肥料のようなNに富むストリームの嫌気性消化中にアンモニウム毒性を減少させる可能性があり、従って、これらの廃棄物の流れからのエネルギー回収を増加させると同時に、一方回復栄養素4。廃棄物に栄養回復技術は、尿、それによってWWTP 7における栄養素を除去するためのコストを回避するような高TAN含量ストリームとして電気化学的およびアンモニウムの生物電気化学抽出を適用することもできる。 我々はモジュール式反応器を用いるようにここに提示プロトコルは、多くの異なる化学的及び生物電気化学実験のための基礎として役立つことができる。以下のプロトコールで説明したように異なる電極タイプ、膜およびフレームの厚さを組み合わせることができる。プロトコルの主な目的は、電解セルを用いた電気化学アンモニウム回収、バイオ電気化学アンモニウム回復を比較するための手段を提供することである。システムは、抽出効率、電力入力および再現性の観点から評価される。

<table border="0" cellpadding="0" cellspacing="0" width="876">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:192px;">Company</td>
			<td style="width:301px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Carbon Felt 3.18 mm Thick&#160;</td>
			<td style="width:192px;">Alfa Aesar</td>
			<td style="width:301px;">ALFA43199</td>
			<td>Used as bioanode, 110 mm x 110 mm</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Ti electrode coated with Ir MMO&#160;</td>
			<td style="width:192px;">Magneto Special Anodes (The Netherlands)</td>
			<td style="width:301px;"></td>
			<td>Used as stable anode for electrochemical tests</td>
		</tr>
		<tr height="73">
			<td height="73" style="height:74px;width:216px;">Stainless steel mesh</td>
			<td style="width:192px;">Solana (Belgium)</td>
			<td style="width:301px;">RVS 554/64: material AISI 316L, mesh width: 564 micron, wire thickness: 140 micron, mesh number: 36,6</td>
			<td>Used as cathode, 110 mm x 110 mm</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:216px;">Stainless steel plate</td>
			<td style="width:192px;">Solana (Belgium)</td>
			<td style="width:301px;">inox 304 sheet, thickness: 0,5mm</td>
			<td>Used as current collector for the bioanode</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ag/AgCl Reference Electrode</td>
			<td style="width:192px;">Bio-Logic (France)</td>
			<td style="width:301px;">A-012167 RE-1B</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Potentiostat (VSP Multipotentiostat)&#160;</td>
			<td style="width:192px;">Bio-Logic (France)</td>
			<td style="width:301px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">EC Lab</td>
			<td style="width:192px;">Bio-Logic (France)</td>
			<td style="width:301px;"></td>
			<td>software for performing electrochemistry measurements</td>
		</tr>
		<tr height="44">
			<td height="44" style="height:44px;width:216px;">Cation Exchange Membrane</td>
			<td style="width:192px;">Membranes International (USA)</td>
			<td style="width:301px;">Ultrex CMI-7000</td>
			<td>Pretreated according to the manufacturers&#39; instructions</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Turbulence Promotor mesh</td>
			<td style="width:192px;">ElectroCell Europe A/S (Tarm, Denmark)</td>
			<td style="width:301px;">EPC20432-PP-2</td>
			<td>spacer material, 110 mm x 110 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Connectors</td>
			<td style="width:192px;">Serto</td>
			<td style="width:301px;">1,281,161,120</td>
			<td>Other sizes possible, dependant on tubing type and size of holes in frames</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Strip and absorption column</td>
			<td style="width:192px;"></td>
			<td style="width:301px;"></td>
			<td>In house design</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tubing</td>
			<td style="width:192px;">Masterflex</td>
			<td style="width:301px;">HV-06404-16</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Gas bag</td>
			<td style="width:192px;">Keika Ventures</td>
			<td style="width:301px;"></td>
			<td>Kynar gas bag with Roberts valve</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Rashig Rings</td>
			<td style="width:192px;">Glasatelier Saillart (Belgium)</td>
			<td style="width:301px;">Raschig rings 4 x 4 mm</td>
			<td>Put inside the strip and absorption column to improve the air/liquid contact. Available with many suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Rubber sheet</td>
			<td style="width:192px;"></td>
			<td style="width:301px;"></td>
			<td>Cut to fit on the perspex frames</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Perspex reactor frames</td>
			<td style="width:192px;">Vlaeminck, Beernem</td>
			<td style="width:301px;"></td>
			<td>In-house design, see tab &#34;reactor frames&#34; in this file</td>
		</tr>
	</tbody>
</table>

electrochemically and bioelectrochemically induced ammonium recovery

Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made.
This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems.

バイオリアクターからのクロノアンペロメトリーの結果 クロノアンペロメトリーの結果は、式（1）に従って算出（ 図4）連続反応のための典型的なグラフを示している。実験の開始時に、アノード及びカソードは、再循環モードで操作した。これは開発するバイオフィルムと、現在の生産の開始を可能にする。操作の5日後に、電流密度は、現?...

Watch this Scientific Journal Video about Electrochemically and Bioelectrochemically Induced Ammonium Recovery at JoVE.com

Electrochemically and Bioelectrochemically Induced Ammonium Recovery

We demonstrate the extraction of ammonium from an ammonium-rich stream using an electrochemical and a bioelectrochemical system. The reactor setup, operation and data analysis are discussed.

電気化学的およびBioelectrochemically誘起アンモニウム回復

Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ...

electrochemically-and-bioelectrochemically-induced-ammonium-recovery

Research

Education

JoVE Journal

JoVE Core

Chemistry

Chemical Equilibrium

SCIENTISTS IN ACTION

12.6K ビュー.  Ghent University. We demonstrate the extraction of ammonium from an ammonium-rich stream using an electrochemical and a bioelectrochemical system. The reactor setup, operation and data analysis are discussed. 

ビデオ: Electrochemically and Bioelectrochemically Induced Ammonium Recovery

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Copper (I) binding by metallochaperone transport proteins prevents copper oxidation and release of the toxic ions that may participate in harmful redox reactions. The Cu (I) complex of the peptide model of a Cu (I) binding metallochaperone protein, which includes the sequence MTCSGCSRPG (underlined is conserved), was determined in solution under inert conditions by NMR spectroscopy.
NMR is a widely accepted technique for the determination of solution structures of proteins and peptides. Due to difficulty in crystallization to provide single crystals suitable for X-ray crystallography, the NMR technique is extremely valuable, especially as it provides information on the solution state rather than the solid state. Herein we describe all steps that are required for full three-dimensional structure determinations by NMR. The protocol includes sample preparation in an NMR tube, 1D and 2D data collection and processing, peak assignment and integration, molecular mechanics calculations, and structure analysis. Importantly, the analysis was first conducted without any preset metal-ligand bonds, to assure a reliable structure determination in an unbiased manner.

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

The NMR-solution structure of a metallochaperone model peptide with Cu (I) was determined, and a detailed protocol from sample preparation and 1D and 2D data collection to a three-dimensional structure is described.

Copper (I) binding by metallochaperone transport proteins prevents copper oxidation and release of the toxic ions that may participate in harmful redox ...

化学

Dependence of Laser-induced Breakdown Spectroscopy Results on Pulse Energies and Timing Parameters Using Soil Simulants

The dependence of some LIBS detection capabilities on lower pulse energies (&lt;100 mJ) and timing parameters were examined using synthetic silicate samples. These samples were used as simulants for soil and contained minor and trace elements commonly found in soil at a wide range of concentrations. For this study, over 100 calibration curves were prepared using different pulse energies and timing parameters; detection limits and sensitivities were determined from the calibration curves. Plasma temperatures were also measured using Boltzmann plots for the various energies and the timing parameters tested. The electron density of the plasma was calculated using the full-width half maximum (FWHM) of the hydrogen line at 656.5 nm over the energies tested. Overall, the results indicate that the use of lower pulse energies and non-gated detection do not seriously compromise the analytical results. These results are very relevant to the design of field- and person-portable LIBS instruments.

LIBS detection capabilities on soil simulants were tested using a range of pulse energies and timing parameters. Calibration curves were used to determine detection limits and sensitivities for different parameters. Generally, the results showed that there was not a significant reduction in detection capabilities using lower pulse energies and non-gated detection.

土壌模擬を使用したパルスエネルギーおよびタイミングパラメータにレーザー誘起ブレークダウン分光法の結果の依存性

The  dependence of some LIBS detection capabilities on lower pulse energies (&lt;100  mJ) and timing parameters were examined using synthetic silicate ...

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid phase by using combinatorial chemistry. One of the most well studied classes of peptidomimetics is peptoids. Peptoids are easy to synthesize and have been shown to be proteolysis-resistant and cell-permeable. Over the past decade, many useful protein ligands have been identified through screening of peptoid libraries. However, most of the ligands identified from peptoid libraries do not display high affinity, with rare exceptions. This may be due, in part, to the lack of chiral centers and conformational constraints in peptoid molecules. Recently, we described a new synthetic route to access peptide tertiary amides (PTAs). PTAs are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. With side chains on both &#945;-carbon and main chain nitrogen atoms, the conformation of these molecules are greatly constrained by sterical hindrance and allylic 1,3 strain. (Figure 1) Our study suggests that these PTA molecules are highly structured in solution and can be used to identify protein ligands. We believe that these molecules can be a future source of high-affinity protein ligands. Here we describe the synthetic method combining the power of both split-and-pool and sub-monomer strategies to synthesize a sample one-bead one-compound (OBOC) library of PTAs.

Peptide tertiary amides (PTAs) are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. Here we describe a synthetic method which combines&#160;both split-and-pool and sub-monomer strategies to synthesize a one-bead one-compound library of PTAs.

ペプチド第三級アミドライブラリのスプリット·アンド·プールの合成とキャラクタリゼーション

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid ...

Preparation of Mica and Silicon Substrates for DNA Origami Analysis and Experimentation

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of these applications require interaction with and adhesion of DNA nanostructures to a substrate. Due to its atomically flat and easily cleaned nature, mica has been the substrate of choice for DNA origami experiments. However, the practical applications of mica are relatively limited compared to those of semiconductor substrates. For this reason, a straightforward, stable, and repeatable process for DNA origami adhesion on derivatized silicon oxide is presented here. To promote the adhesion of DNA nanostructures to silicon oxide surface, a self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) is deposited from an aqueous solution that is compatible with many photoresists. The substrate must be cleaned of all organic and metal contaminants using Radio Corporation of America (RCA) cleaning processes and the native oxide layer must be etched to ensure a flat, functionalizable surface. Cleanrooms are equipped with facilities for silicon cleaning, however many components of DNA origami buffers and solutions are often not allowed in them due to contamination concerns. This manuscript describes the set-up and protocol for in-lab, small-scale silicon cleaning for researchers who do not have access to a cleanroom or would like to incorporate processes that could cause contamination of a cleanroom CMOS clean bench. Additionally, variables for regulating coverage are discussed and how to recognize and avoid common sample preparation problems is described.

Reproducible cleaning processes for substrates used in DNA origami research are described, including bench-top RCA cleaning and derivatization of silicon oxide. Protocols for surface preparation, DNA origami deposition, drying parameters, and simple experimental set-ups are illustrated.

DNA折り紙解析と実験のためのマイカとシリコン基板の作製

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of ...

Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar concentration forming hydrophobic cores surrounded by hydrophilic shells in aqueous environments. The core of these micelles can be utilized to load hydrophobic, poorly water soluble drugs like docetaxel (DTX) and everolimus (EVR). Systematic characterization of the micelle structure and drug loading capabilities are important before in vitro and in vivo studies can be conducted. The goal of the protocol described herein is to provide the necessary characterization steps to achieve standardized micellar products. DTX and EVR have intrinsic solubilities of 1.9 and 9.6 &#181;g/ml respectively Preparation of these micelles can be achieved through solvent casting which increases the aqueous solubility of DTX and EVR to 1.86 and 1.85 mg/ml, respectively. Drug stability in micelles evaluated at room temperature over 48 hr indicates that 97% or more of the drugs are retained in solution. Micelle size was assessed using dynamic light scattering and indicated that the size of these micelles was below 50 nm and depended on the molecular weight of the polymer. Drug release from the micelles was assessed using dialysis under sink conditions at pH 7.4 at 37 oC over 48 hr. Curve fitting results indicate that drug release is driven by a first order process indicating that it is diffusion driven.

The goal of this protocol is to describe the preparation and characterization of physically entrapped, poorly water soluble drugs in micellar drug delivery systems composed of amphiphilic block copolymers.

調製とキャラクタリゼーション個々のとマルチ薬ロード物理的に捕捉さ高分子ミセル

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar ...

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Enzyme catalysis evolved in an aqueous environment. The influence of solvent dynamics on catalysis is, however, currently poorly understood and usually neglected. The study of water dynamics in enzymes and the associated thermodynamical consequences is highly complex and has involved computer simulations, nuclear magnetic resonance (NMR) experiments, and calorimetry. Water tunnels that connect the active site with the surrounding solvent are key to solvent displacement and dynamics. The protocol herein allows for the engineering of these motifs for water transport, which affects specificity, activity and thermodynamics. By providing a biophysical framework founded on theory and experiments, the method presented herein can be used by researchers without previous expertise in computer modeling or biophysical chemistry. The method will advance our understanding of enzyme catalysis on the molecular level by measuring the enthalpic and entropic changes associated with catalysis by enzyme variants with obstructed water tunnels. The protocol can be used for the study of membrane-bound enzymes and other complex systems. This will enhance our understanding of the importance of solvent reorganization in catalysis as well as provide new catalytic strategies in protein design and engineering.

Channels for the transportation of water molecules in enzymes influence active site solvation and catalysis. Herein we present a protocol for the engineering of these additional catalytic motifs based on in silico computer modeling and experiments. This will enhance our understanding of the influence of solvent dynamics on enzyme catalysis.

膜酵素で溶剤ダイナミクスによって誘導される解明エントロピーレートの高速化

Enzyme catalysis evolved in an aqueous environment. The influence of solvent dynamics on catalysis is, however, currently poorly understood and usually ...

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Functions of clusters in nano or sub-nano scale significantly depend on not only kinds of their components but also arrangements, or symmetry, of their components. Therefore, the arrangements in the clusters have been precisely characterized, especially for metal complexes. Contrary to this, characterizations of molecular arrangements in supramolecular clusters composed of organic molecules are limited to a few cases. This is because construction of the supramolecular clusters, especially obtaining a series of the supramolecular clusters, is difficult due to low stability of non-covalent bonds compare to covalent bonds. From this viewpoint, utilization of organic salts is one of the most useful strategies. A series of the supramolecules could be constructed by combinations of a specific organic molecule with various counter ions. Especially, primary ammonium carboxylates are suitable as typical examples of supramolecules because various kinds of carboxylic acids and primary amines are commercially available, and it is easy to change their combinations. Previously, it was demonstrated that primary ammonium triphenylacetates using various kinds of primary amines specifically construct supramolecular clusters, which are composed of four ammoniums and four triphenylacetates assembled by charge-assisted hydrogen bonds, in crystals obtained from non-polar solvents. This study demonstrates an application of the specific construction of the supramolecular clusters as a strategy to conduct systematical symmetric study for clarification of correlations between molecular arrangements in supramolecules and kinds and numbers of their components. In the same way with binary salts composed of triphenylacetates and one kind of primary ammoniums, ternary organic salts composed of triphenylacetates and two kinds of ammoniums construct the supramolecular clusters, affording a series of the supramolecular clusters with various kinds and numbers of the components.

This article describes construction of a series of hydrogen-bonding supramolecular clusters in crystals using primary ammonium triphenylacetates, which are recrystallized from non-polar solvents. This selective construction of the supramolecular clusters leads to effective systematical symmetric studies about a correlation between the supramolecular clusters and their components.

バイナリまたは三元アンモニウムTriphenylacetatesと超分子クラスターのシリーズの構築と体系的対称研究

Functions of clusters in nano or sub-nano scale significantly depend on not only kinds of their components but also arrangements, or symmetry, of their ...

Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

Here we demonstrate potentially low cost and green productions of high thermally stable and carboxylated cellulose nanocrystals (CNCs) and nanofibrils (CNF) from bleached eucalyptus pulp (BEP) and unbleached mixed hardwood kraft pulp (UMHP) fibers using highly recyclable dicarboxylic solid acids. Typical operating conditions were acid concentrations of 50 - 70 wt% at 100 &#176;C for 60 min and 120 &#176;C (no boiling at atmospheric pressure) for 120 min, for BEP and UMHP, respectively. The resultant CNCs have a higher thermal degradation temperature than their corresponding feed fibers and carboxylic acid group content from 0.2 - 0.4 mmol/g. The low strength (high pKa of 1.0 - 3.0) of organic acids also resulted in CNCs with both longer lengths of approximately 239 - 336 nm and higher crystallinity than CNCs produced using mineral acids. Cellulose loss to sugar was minimal. Fibrous cellulosic solid residue (FCSR) from the dicarboxylic acid hydrolysis was used to produce carboxylated CNFs through subsequent mechanical fibrillation with low energy input.

Here we demonstrate a novel method for green and sustainable productions of highly thermally stable and carboxylated cellulose nanocrystals (CNC) and nanofibrils (CNF) using highly recyclable solid dicarboxylic acids.

緑とリサイクル性の高いジカルボン酸を使用して熱的に安定したカルボキシル化セルロースナノ結晶とナノフィブリルの低コスト生産

Here we demonstrate potentially low cost and green productions of high thermally stable and carboxylated cellulose nanocrystals (CNCs) and nanofibrils ...

Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy

Water/solid interfaces are ubiquitous and play a key role in many environmental, biophysical, and technological processes. Resolving the internal structure and probing the hydrogen-bond (H-bond) dynamics of the water molecules adsorbed on solid surfaces are fundamental issues of water science, which remains a great challenge owing to the light mass and small size of hydrogen. Scanning tunneling microscopy (STM) is a promising tool for attacking these problems, thanks to its capabilities of sub-&#197;ngstr&#246;m spatial resolution, single-bond vibrational sensitivity, and atomic/molecular manipulation. The designed experimental system consists of a Cl-terminated tip and a sample fabricated by dosing water molecules in situ onto the Au(111)-supported NaCl(001) surfaces. The insulating NaCl films electronically decouple the water from the metal substrates, so the intrinsic frontier orbitals of water molecules are preserved. The Cl-tip facilitates the manipulation of the single water molecules, as well as gating the orbitals of water to the proximity of Fermi level (EF) via tip-water coupling. This paper outlines the detailed methods of submolecular resolution imaging, molecular/atomic manipulation, and single-bond vibrational spectroscopy of interfacial water. These studies open up a new route for investigating the H-bonded systems at the atomic scale.

Here, we present a protocol to investigate the structure and dynamics of interfacial water at the atomic scale, in terms of submolecular resolution imaging, molecular manipulation, and single-bond vibrational spectroscopy.

構造と走査型トンネル顕微鏡および分光法による界面の水のダイナミクスを調べる

Water/solid interfaces are ubiquitous and play a key role in many environmental, biophysical, and technological processes. Resolving the internal ...

Constructing Thioether/Vinyl Sulfide-tethered Helical Peptides Via Photo-induced Thiol-ene/yne Hydrothiolation

Here, we describe a detailed protocol for the preparation of thioether-tethered peptides using on-resin intramolecular/intermolecular thiol-ene hydrothiolation. In addition, this protocol describes the preparation of vinyl-sulfide-tethered peptides using in-solution intramolecular thiol-yne hydrothiolation between amino acids that possess alkene/alkyne side chains and cysteine residues at i, i+4 positions. Linear peptides were synthesized using a standard Fmoc-based solid-phase peptide synthesis (SPPS). Thiol-ene hydrothiolation is carried out using either an intramolecular thio-ene reaction or an intermolecular thio-ene reaction, depending on the peptide length. In this research, an intramolecular thio-ene reaction is carried out in the case of shorter peptides using on-resin deprotection of the trityl groups of cysteine residues following the complete synthesis of the linear peptide. The resin is then set to UV irradiation using photoinitiator 4-methoxyacetophenone (MAP) and 2-hydroxy-1-[4-(2-hydroxyethoxy)-phenyl]-2-methyl-1-propanone (MMP). The intermolecular thiol-ene reaction is carried out by dissolving Fmoc-Cys-OH in an N,N-dimethylformamide (DMF) solvent. This is then reacted with the peptide using the alkene-bearing residue on resin. After that, the macrolactamization is carried out using benzotriazole-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBop), 1-hydroxybenzotriazole (HoBt), and 4-Methylmorpholine (NMM) as activation reagents on the resin. Following the macrolactamization, the peptide synthesis is continued using standard SPPS. In the case of the thio-yne hydrothiolation, the linear peptide is cleaved from the resin, dried, and subsequently dissolved in degassed DMF. This is then irradiated using UV light with photoinitiator 2,2-dimethoxy-2-phenylacetophenone (DMPA). Following the reaction, DMF is evaporated and the crude residue is precipitated and purified using high-performance liquid chromatography (HPLC). These methods could function to simplify the generation of thioether-tethered cyclic peptides due to the use of the thio-ene/yne click chemistry that possesses superior functional group tolerance and good yield. The introduction of thioether bonds into peptides takes advantage of the nucleophilic nature of cysteine residues and is redox-inert relative to disulfide bonds.

We present a protocol for the construction of thioether/vinyl sulfide-tethered helical peptides using photo-induced thiol-ene/thiol-yne hydrothiolation.