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>
	<li>Verstraete, W., Van de Caveye, P., Diamantis, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maximum+use+of+resources+present+in+domestic+&#34;used+water&#34;.">Maximum use of resources present in domestic &#34;used water&#34;.</a> Bioresource Technology. 100 (23), 5537-5545 (2009).</li><li>Lei, X., Sugiura, N., Feng, C., Maekawa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pretreatment+of+anaerobic+digestion+effluent+with+ammonia+stripping+and+biogas+purification.">Pretreatment of anaerobic digestion effluent with ammonia stripping and biogas purification.</a> Journal of Hazardous Materials. 145 (3), 391-397 (2007).</li><li>Siegrist, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitrogen+removal+from+digester+supernatant-comparison+of+chemical+and+biological+methods.">Nitrogen removal from digester supernatant-comparison of chemical and biological methods.</a> Water Science and Technology. 34 (1), 399-406 (1996).</li><li>Desloover, J., Abate Woldeyohannis, A., Verstraete, W., Boon, N., Rabaey, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+Resource+Recovery+from+Digestate+to+Prevent+Ammonia+Toxicity+during+Anaerobic+Digestion.">Electrochemical Resource Recovery from Digestate to Prevent Ammonia Toxicity during Anaerobic Digestion.</a> Environmental Science &amp; Technology. 46 (21), 12209-12216 (2012).</li><li>Kim, J. R., Zuo, Y., Regan, J. M., Logan, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+ammonia+loss+mechanisms+in+microbial+fuel+cells+treating+animal+wastewater.">Analysis of ammonia loss mechanisms in microbial fuel cells treating animal wastewater.</a> Biotechnology and Bioengineering. 99 (5), 1120-1127 (2008).</li><li>Emerson, K., Russo, R. C., Lund, R. E., Thurston, R. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aqueous+ammonia+equilibrium+calculations:+effect+of+pH+and+temperature.">Aqueous ammonia equilibrium calculations: effect of pH and temperature.</a> Journal of the Fisheries Board of Canada. 32 (12), 2379-2383 (1975).</li><li>Kuntke, P., Sleutels, T. H. J. A., Saakes, M., Buisman, C. J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrogen+production+and+ammonium+recovery+from+urine+by+a+Microbial+Electrolysis+Cell.">Hydrogen production and ammonium recovery from urine by a Microbial Electrolysis Cell.</a> International Journal of Hydrogen Energy. 39 (10), 4771-4778 (2014).</li><li>Guo, K., 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=Surfactant+treatment+of+carbon+felt+enhances+anodic+microbial+electrocatalysis+in+bioelectrochemical+systems.">Surfactant treatment of carbon felt enhances anodic microbial electrocatalysis in bioelectrochemical systems.</a> Electrochemistry Communications. 39, 1-4 (2014).</li><li>Guo, K., Chen, X., Freguia, S., Donose, B. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spontaneous+modification+of+carbon+surface+with+neutral+red+from+its+diazonium+salts+for+bioelectrochemical+systems.">Spontaneous modification of carbon surface with neutral red from its diazonium salts for bioelectrochemical systems.</a> Biosensors and Bioelectronics. 47, 184-189 (2013).</li><li>Rice, E. W., Greenberg, A. E., Clesceri, L. S., Eaton, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Standard Methods For The Examination Of Water And Wastewater. , (1992).</li><li>Andersen, S. 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=Electrolytic+Membrane+Extraction+Enables+Production+of+Fine+Chemicals+from+Biorefinery+Sidestreams.">Electrolytic Membrane Extraction Enables Production of Fine Chemicals from Biorefinery Sidestreams.</a> Environmental Science &amp; Technology. 48 (12), 7135-7142 (2014).</li><li>Harnisch, F., Rabaey, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Diversity+of+Techniques+to+Study+Electrochemically+Active+Biofilms+Highlights+the+Need+for+Standardization.">The Diversity of Techniques to Study Electrochemically Active Biofilms Highlights the Need for Standardization.</a> Chemsuschem. 5 (6), 1027-1038 (2012).</li><li>Clauwaert, P., 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=Minimizing+losses+in+bio-electrochemical+systems:+the+road+to+applications.">Minimizing losses in bio-electrochemical systems: the road to applications.</a> Applied Microbiology and Biotechnology. 79 (6), 901-913 (2008).</li><li>Atkins, P., De Paula, 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> Elements of Physical Chemistry. , (2012).</li><li>Aelterman, P., Freguia, S., Keller, J., Verstraete, W., Rabaey, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anode+potential+regulates+bacterial+activity+in+microbial+fuel+cells.">The anode potential regulates bacterial activity in microbial fuel cells.</a> Applied Microbiology and Biotechnology. 78 (3), 409-418 (2008).</li><li>Kuntke, P., 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=Ammonium+recovery+and+energy+production+from+urine+by+a+microbial+fuel+cell.">Ammonium recovery and energy production from urine by a microbial fuel cell.</a> Water Research. 46 (8), 2627-2636 (2012).</li><li>Liu, H., Cheng, S., Logan, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Power+Generation+in+Fed-Batch+Microbial+Fuel+Cells+as+a+Function+of+Ionic+Strength.">Power Generation in Fed-Batch Microbial Fuel Cells as a Function of Ionic Strength.</a> Temperature, and Reactor Configuration. Environmental Science &amp; Technology. 39 (14), 5488-5493 (2005).</li><li>Gimkiewicz, C., Harnisch, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Waste+Water+Derived+Electroactive+Microbial+Biofilms:+Growth,+Maintenance,+and+Basic+Characterization.">Waste Water Derived Electroactive Microbial Biofilms: Growth, Maintenance, and Basic Characterization.</a> JoVE. (82), e50800 (2013).</li><li>Ping, Q., Cohen, B., Dosoretz, C., He, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+investigation+of+fouling+of+cation+and+anion+exchange+membranes+in+microbial+desalination+cells.">Long-term investigation of fouling of cation and anion exchange membranes in microbial desalination cells.</a> Desalination. 325, 48-55 (2013).</li><li>Guerin, T., Mondido, M., McClenn, B., Peasley, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+resazurin+for+estimating+abundance+of+contaminant-degrading+micro-organisms.">Application of resazurin for estimating abundance of contaminant-degrading micro-organisms.</a> Letters in Applied Microbiology. 32 (5), 340-345 (2001).</li></ol>

The authors have nothing to disclose.

이 원고는 bioelectrochemical 암모늄 복구를위한 전기 화학 셀을 설정하는 데 필요한 도구를 제공합니다. 결과 섹션에 제시된 계산은 시스템 성능의 평가를 위해 파라미터를 제공한다. 생물학적 및 전기 시스템 설치 및 기능에서 유사하다. 두 시스템 사이의 주요 차이점은 bioelectrochemical 셋업 고정 양극 전위 대 전기 화학 셀의 현재의 고정 된 선택이다. 비 생물 적 설정을위한 고정 전류는 전극 반응을...

폐수 이익의 중요성에서 가치있는 제품의 복구 귀중한 자원이 회복없이 부족과 치료가로는 비용을 나타냅니다. 폐수는 생산 루프 1을 닫으하는 데 도움이 될 수 있습니다 에너지 및 복구 할 수 있습니다 영양소, 영양 복구를 모두 포함되어 있습니다. 영양소의 회복이 덜 일반적인 상태에서 혐기성 소화를 통해 에너지의 복구, 잘 설립 과정이다. 뇨 및 배설물과 같은 액상 폐기물 스트림으로부터 영양소의 복구 널리 트루 바이트 및 암모니아 스트리핑 2,3- 직접 제조함으로써, 예를 들면, 연구되어왔다. 그러나, 화학적 첨가의 필요성은 이러한 프로세스 (4)의 단점이다. 여기서 우리는 칼륨 및 암모늄 모두 포함한 폐수로부터 양이온 영양소 복구하는 기술을 제시한다. 이러한 영양소의 양이온 형태는 전기 시스템에서 이온 선택성 막을 사용하여 복구 할 수 있습니다. 이 경우, electrochemic알 시스템 (산화가 일어나는) 양극 실의 구성 (환원이 일어나는)과 음극 실 구획을 분리하는 이온 선택성 막. 전압은 애노드로부터 캐소드로의 전류 흐름을 생성하기 위해 셀에인가된다. 이 전압을 물 산화 및 환원 반응을 구동하기 위해 외부 전원에 의해 생성 될 수있다. 선택적 양극 산화, 예를 들면, 유기물, 더 적은 전력을 필요로하는 전기 활성 박테리아에 의해 촉진 될 수있다. 충전 균형을 회로를 폐쇄하고 유지하기 위해, 충전 된 종은 생성 된 각 전자의 전극 사이에 마이그레이션해야합니다. 양이온 교환막 (CEM)에 걸쳐 음극 실에 양극 실에서 암모늄 따라서 트랜스 4,5 전자의 플럭스를 보상 할 수있다. 여기에 제시된 기술뿐만 아니라 폐기물에서 암모늄을 제거하지만 또한 복구 할 수 있습니다. 총 암모니아 성 질소 (TAN)은 모두 암몬의 평형에 존재IUM (NH + 4) 및 암모니아 (NH 3), 및 6의 pH 및 온도에 의존한다. NH 4 + 인해 따라서 음극 실에 걸쳐 CEM 전류에 의해 구동 될 수있는 높은 TAN 농도 및 양극 실의 pH가 중성이 양전하 종 근처 풍부하게된다. 전류는 수산화 이온 및 수소 가스의 생산에 이르는, 음극에서 물의 감소를 구동한다. TAN 평형으로 인해 음극 실 (&gt; 10.0)의 높은 pH로 거의 100 % NH 3으로 이동한다. NH 3는 쉽게 산성 용액에서 포획하고 농축 포집 탑에 스트리핑 부에서 공기 순환을 통해 전송 될 수있는 가스이다. 이 기술은 분뇨와 같은 N - 농후 스트림의 혐기성 소화 동안 암모늄 독성을 감소시키는 잠재력을 보유하고, 따라서, 이들 폐기물 스트림에서의 에너지 회수를 증가하면서 동시에복구 영양소 4. 암모늄의 전기 및 추출 bioelectrochemical 또한 뇨함으로써 WWTP 7에 영양소 제거 비용을 회피 같이 높은 TAN 함량 폐기물에 영양소 회수 기술로서 적용 할 수있다. 우리가 사용하는 모듈 형 반응기로 여기에 제시된 프로토콜은, 다양한 전기 화학적 및 bioelectrochemical 실험 기반이 될 수있다. 아래에 설명 된 것처럼 프로토콜 전극 유형 막 두께와 프레임은 서로 다른 결합 될 수있다. 프로토콜의 주요 목적은 전기 분해 셀을 이용하여 전기 화학적 암모늄 복구 및 전기 화학적 바이오 암모늄 회복의 비교를위한 수단을 제공하는 것이다. 시스템은 추출 효율, 전원 입력과 재현성 측면에서 평가됩니다.

<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.

Chronoamperometry는 생물 반응기의 결과 chronoamperometry 결과, 수학 식 1에 따라 계산 (그림 4) 연속 반응에 대한 전형적인 그래프를 보여줍니다. 실험 시작시의 양극과 음극은 재순환 모드로 작동시켰다. 이것은 개발 생물막과 현재의 생산의 개시를 허용한다. 수술 5 일 후에, 전류 밀도는 현재의 생산의 감소에 이어 최대에 도달. 이 바이오 필름은 현재 생?...

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.

전기 및 Bioelectrochemically 유도 암모늄 복구

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 조회수.  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. 

비디오: 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 ...

연구

화학

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.

토양 닮은를 사용하여 펄스 에너지 및 타이밍 매개 변수에 대한 레이저 유도 내역 분광학 결과의 의존

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.

분할 및 풀 합성 펩타이드 급 아미드 도서관의 특성

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 종이 접기 분석 및 실험에 대한 운모와 실리콘 기판의 제조

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.

준비 및 개인의 특성과 다중 약물은 물리적으로 고분자 미셀을 포획로드

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.

막 효소 용매 역학에 의해 유도 탈피 엔트 속도 가속

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.

건설 및 바이너리 또는 삼항 암모늄 Triphenylacetates와 초분자 클러스터의 시리즈의 체계적 대칭 연구

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.

열 안정성 및 카르 셀룰로오스 나노 결정과 Nanofibrils를 사용하여 재활용도가 높은 디카 르 복실 산의 녹색과 저비용 생산

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.

구조와 계면 물 검색과 터널링 현미경 분광학의 역학 조사

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.