作者感谢韦斯·戈登博士（ECBC），用于支持在仪器设计。这项工作是由埃里克·温斯坦和迈克尔·罗伯茨（国防威胁降低局）根据计划CA08MSB317资助的两个研究项目的累积结果。本文引用的技术报告可在以下<a href="http://www.dtic.mil">http://www.dtic.mil</a> 。

1，条件涂料底物的所期望的环境<ol><li>预设的环境室的基板调节到规定的温度和相对湿度（20℃，50％）。确保基板的条件一直保持，因为两者的温度和水含量可以吸收率显著影响到材料。 </li><li>外套0.32厘米厚，5.08厘米半径不锈钢圆片与20.25 平方厘米，表面积有一层涂料（MIL-DTL-53039，溶剂分散性（标准差）的脂肪族聚氨酯涂料系统6）总涂层厚度（大约为100微米的底漆和面漆）。放置在基板（具有重复的期望的数量）在不锈钢托盘与试验表面被暴露在朝上的化学试剂。 </li><li>盖上培养皿的底物。含有试验衬底的托盘放入环境腔室至少60英里n，而是理想的O / N，如果可能的话。 </li></ol> 2，污染预处理基底的<ol><li>唐的个人防护装备，如实验室外套，护目镜和手套。 </li><li>注意：获取从冷库中的化学污染物，并允许初级容器小瓶中平衡至室温。在这个协议中使用的化学品化学战剂的分析标准参考物质（CASARM，98.0％纯度）级高清和CASARM（89.0％高纯度）级VX（包括液相）。从任一核磁共振或气相色谱法/质谱法分析得到的纯度的信息和对文件的维护。 注：警告：化学战剂的处理只能由经过培训的人员在经批准的设施使用相关的安全，保安和担保注意事项执行。 </li><li>注意：安装代理递送工具用枪头和配置提供代理液滴（ 如 1微升）的工具。摘帽了污染物小瓶，然后将引擎盖上表面的帽，螺纹朝上。拿起吸管，慢慢放下尖端插入污染物的解决方案。加载剂递送工具代理按照制造商的指示。轻轻将吸管装上遮光罩的工作表面，并盖上污染物小瓶。 </li><li>注意：污染测试基板。 <ol><li>删除包含从环境试验箱试验基板的托盘。 </li><li>从测试基板取出培养皿，并在罩的表面上。数字拍摄各试验基体，记录每个基片的污染前的外观。 </li><li>拿起装吸管，并提供一个单一的液滴（ 如 1微升）的代理到第一测试基板。覆盖污染的材料有聚苯乙烯培养皿中，以减少蒸发，同时污染额外的底物。重复每个基片;重装枪头（STEP 2.3）是必要的。 注：前，通过色谱分析底物给药后收集吸管确认样品，以确认污染物的质量交付。 </li><li>从测试基板取出培养皿和引擎盖上表面设置。数字拍摄各试验基体，记录初始污染物的材料的相互作用。 </li><li>覆盖测试基板的培养皿。 </li><li>放置衬底的托盘放回环境室。 </li></ol></li></ol> 3，污染物物质相互作用老化期<ol><li>之前老化的样品中，放空不锈钢高真空实验室向它的第4制备的使用。 </li><li>使被污染的基底与年龄的环境室，用于在指定的持续时间，其可以基于所述化学物质与环境相互作用动力学（ 例如 ，60分钟）而变化的。 </li><li>从环境功能移除基板威威廉斯室和地方机罩的工作表面上。从测试基板取出培养皿和数字拍摄的每个基片记录后老化污染物质的相互作用。 </li><li>双包含测试样品（ 例如 ，多个气密容器）和转移到工作机罩具有高真空腔室中。 </li></ol> 4，高真空蒸发排放测试室在高真空室抽用涡轮分子拖动泵和膜片的前级泵（ 图2）的小体积容器。一种四极质谱仪上安装有端口直接面对温度控制的衬底保持器和用于测量从高真空条件下，受污染的基材实时放出气体上。是在真空腔室的规格和材料的全部细节包括在参考文献4。 <ol><li>确保室内适当通风。 </li><li>小心：解包在第3节中制备的样品，并且从测试基板取出培养皿。放置一测试衬底送入用不锈钢镊子每个温度控制的衬底保持器。 </li><li>密封在真空室，并开始抽空序列。执行这个步骤，使得所述腔室是真空中于指定年龄时的密封（ 例如 ，60分钟），就当衬底被污染。 </li><li>开始录制选择的质量碎片频道作为时间确定每单位电荷的值特定的质量（m / z）的一个函数（直接测量质量流量的）。测量特定背景气体物种除了从感兴趣的分子的主要质量碎片：;：实时（VX M / Z = 114的HD M / Z = 109），在&lt;0.25赫兹，直到污染物的分压降至低于检测限的质谱仪（10 - 8帕）。 </li><li>收集用于发射曲线污染物从衬底发射的持续时间。 </li><li>停止录制与质谱仪发射曲线一旦污染物质量通量减小到腔室压力基线。 </li><li>泄的高真空室中的大气压力。 </li></ol> 5，治疗后评价总剩余污染物<ol><li>开启高真空蒸气排放室（HVVEC）仪器和除去从使用不锈钢镊子腔室中的衬底。 </li><li>将底物转化为玻璃萃取罐和添加20毫升萃取溶剂的罐子（ 例如 ，异丙醇：VX：氯仿：HD）。盖上罐子，摇动瓶子三次。留在萃取溶剂中的底物60分钟。 </li><li>再次摇动瓶子三次，然后开盖的罐子。使用干净的，一次性的，玻璃吸管，通过气体或液体转移约1〜2毫升的萃取溶剂的成分析小瓶中以供分析色谱7测量污染物质量的衬底保留。 </li></ol> 6，数据分析和建模<ol><li>原始质谱数据（从测量离子电流的偏压力）转换为质量流量从衬底。使用赫兹 - 克努森式的组合，用于将检测到的气体物种的分压与入射蒸汽熔剂在检测器和包括该占从原始污染事件在衬底上的污染区域的缩放因子。 </li><li>利用反演方法（ 例如 ，Levenberg-Marquardt算法）来确定通过油漆涂料的污染物运移的饱和浓度和扩散常数的值（关键质量传输参数）。比较试验确定水汽通量预测水汽通量（施加适当的边界条件下的解析解菲克第二定律（见式（4）从参考文献4））。 </li&gt; <li>使用质量传递的参数来预测对污染物的材料体系中的浓度分布。 </li></ol>

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作者什么都没有透露。

用于HD和VX的油漆质量传递的参数是通过蒸气排放数据的数值反演分析确定。与计算出的参数，有可能再产生随时间变化的浓度梯度映射为在油漆涂层的污染物分布。逆分析结果表明，HD的在SD涂料中的溶解度比VX为高，但扩散度为约5倍以下。该结果表明，HD污染是高度浓缩在涂层的表面上，而对VX污染信息通过SD漆涂层穿透。因此，对于标清喷漆净化需求将有所不同根据化学污染物。这种方法的应?...

用的材料污染的化学战剂相关联的质量传递机构是由各种卷积处理，其中包括物理状态转换，移动物种之间的化学相互作用，与材料界面驱动。开发有效的净化技术，优化的净化程序，以及预测模式，这一点是至关重要的污染过程是众所周知的，包括污染物的运输成材料通过吸收和随后的化学排放回环境中。因此，当务之急是方法被开发，可用于评估污染物质对由于环境条件的地下浓度分布。甲连续尺度，基于物理学的模型的开发是为了预测在被污染的基底吸收剂的浓度分布。实验得出的质量传递参数使T的预测他蒸气的污染物质净化后排放。的预测中的材料的浓度分布的能力可以促进潜在蒸气危害的评估，并反过来，使毒性危险1的准确的诊断。这种方法允许对污染物的材料对特定质量传输参数，如扩散和饱和浓度的估算，这反过来允许建模的其他方案和条件。在这项研究中，我们已经处理过的溶剂分散，聚氨酯漆涂料液相污染的化学战剂双（2 -氯乙基）硫醚（蒸芥菜，疱剂HD）和O -乙基南- [2 - （异丙基氨基）乙基] methylphosphonothioate（VX），有机磷神经毒剂。 所开发的方法，从污染的材料，包括像HD和VX化学战剂的特征气体解吸曲线，无许多妨碍其他限制接近2,3。时间分辨质谱污染物演变测量受污染的基材允许与反分析扩散输运模型来计算污染物的材料，包括从原来的渗透活动启动污染物的吸收浓度分布质量传输参数。与建立在材料的环境条件的划定污染物浓度分布的预测能力来评估毒性危险，并最终制定有效去污路线的能力。 在本文中，与样品制备相关的细节被提出，包括化学战剂污染的工作，以及从污染的材料的实验数据的收集和随后的模型4。实验中同样进行递减进项税的化学污染物和去污剂源文献5中，并在接下来的部分将讨论。在包括在图1的流程图，用于样品制备和分析步骤。

<table border="0" cellpadding="0" cellspacing="0" width="646">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:203px;">Name of Material/Equipment</td>
			<td style="width:101px;">Company</td>
			<td style="width:97px;">Catalog Number</td>
			<td style="width:245px;">Comments/Description</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:203px;">Stainless Steel Tray</td>
			<td style="width:101px;">McMaster Carr</td>
			<td style="width:97px;">4189T1</td>
			<td style="width:245px;">13-5/8&#34; L x 9-3/4&#34; W, http://www.mcmaster.com/#stainless-steel-trays/=p8dcgp</td>
		</tr>
		<tr height="67">
			<td height="67" style="height:67px;width:203px;">MIL-DTL-53039 solvent-dispersible aliphatic polyurethane coating system</td>
			<td style="width:101px;"></td>
			<td style="width:97px;"></td>
			<td style="width:245px;">Substrates supplied by internal source</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:203px;">Environmental Chamber</td>
			<td style="width:101px;"></td>
			<td style="width:97px;"></td>
			<td style="width:245px;">Custom Design. Full details on vacuum chamber specifications and materials included in reference 4.</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:203px;">bis(2-chloroethyl) sulfide</td>
			<td style="width:101px;">CASARM</td>
			<td style="width:97px;"></td>
			<td style="width:245px;">TOXIC</td>
		</tr>
		<tr height="65">
			<td height="65" style="height:65px;width:203px;">O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate</td>
			<td style="width:101px;">CASARM</td>
			<td style="width:97px;"></td>
			<td style="width:245px;">TOXIC</td>
		</tr>
		<tr height="49">
			<td height="49" style="height:49px;width:203px;">Pipetter</td>
			<td style="width:101px;">Fisher Scientific</td>
			<td>22260201</td>
			<td style="width:245px;">Range of 1.0 &#181;L to 10 mL</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:203px;">Pipetter Tips</td>
			<td style="width:101px;">Fisher Scientific</td>
			<td style="width:97px;">13-683-709</td>
			<td style="width:245px;">0.1 mL Volume</td>
		</tr>
		<tr height="44">
			<td height="44" style="height:44px;width:203px;">Stainless Steel High Vacuum Experimental Chamber</td>
			<td style="width:101px;"></td>
			<td style="width:97px;"></td>
			<td style="width:245px;">Custom Design</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:203px;">Quadrupole Mass Spectrometer</td>
			<td style="width:101px;">ExTorr</td>
			<td style="width:97px;">RGA300</td>
			<td style="width:245px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:203px;">Stainless Steel Tweezers</td>
			<td style="width:101px;">McMaster Carr</td>
			<td style="width:97px;">5516A15</td>
			<td style="width:245px;">Any stainless steel tweezers are appropriate.</td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:203px;">Glass Extraction Jar</td>
			<td style="width:101px;">Scientific Specialties</td>
			<td style="width:97px;">170808</td>
			<td style="width:245px;">Jar fits a ~5 cm diameter substrate.&#160; Different glass jars with teflon lined lids are appropriate for different sized substrates.</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:203px;">Chloroform</td>
			<td style="width:101px;">Sigma-Aldrich</td>
			<td style="width:97px;">650498</td>
			<td style="width:245px;">HARMFUL.&#160; The extraction solvent for HD may change depending on the analytical method.</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:203px;">Isopropanol</td>
			<td style="width:101px;">Sigma-Aldrich</td>
			<td style="width:97px;">650447</td>
			<td style="width:245px;">HARMFUL.&#160; The extraction solvent for VX may change depending on the analytical method.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:203px;">Pasteur Pipette</td>
			<td style="width:101px;">VWR</td>
			<td style="width:97px;">14673-010</td>
			<td style="width:245px;">size= 5 3/4&#34;</td>
		</tr>
	</tbody>
</table>

an inverse analysis approach to the characterization of chemical transport in paints

直接表征材料中发生的化学品运输和互动的能力（ 即地下动态）是了解污染物大众运输及净化材料的能力的重要组成部分。如果材料被污染，随着时间的推移，高毒性的化学物质（如化学战剂的种类）出来的材料的运输可导致蒸汽暴露或转移到皮肤上，这可能会导致经皮暴露于谁与交互人员材料。由于化学战剂的高毒性，微量化学量的释放是显著关注。吸收剂测绘地下浓度分布和迁移特征使暴露的危险在未经测试的情况进行评估。此外，这些工具可以用来表征地表下的反应动力学，最终设计出更好的去污剂或净化程序。牛逼ö实现这一目标，逆分析质量传递模型方法的开发，利用蒸气排放的从被污染的油漆涂料作为用于对地下浓度分布计算的输入参数的时间分辨质谱法测量。提供了样品制备的详细信息，包括污染物和材料处理，质谱仪的应用程序发出的污染气体的测量，以及反分析使用基于物理学的扩散模型，以确定现场化学战剂的输运性质的实施，包括蒸馏水芥菜（HD）和VX神经毒剂。

图3显示基于时间分辨质谱为VX和HD（主要质量碎片VX所计算的质量流量和HD从SD涂底物的例子在顶板质量电荷比，m / z = 114和109，分别）。四极杆质谱仪，主要有三个组成部分：离子发生器，质量分析器或过滤器，以及充电检测器。气体物质通过电子轰击电离（热丝式电子源）电离，而所产生的离子被注入到四极质量过滤器的途中到达法拉第杯或电子倍增检测器，用于测量离子电...

Watch this Scientific Journal Video about An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints at JoVE.com

An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

在本文中，用于量化在各种材料的化学品的质量传输参数的过程被呈现。这个过程涉及采用一逆分析基于扩散模型为蒸气所记录的实时，质谱法在高真空中发射分布。

一个反分析方法化工运输的油漆表征

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in ...

an-inverse-analysis-approach-to-characterization-chemical-transport

Research

JoVE Journal

Chemistry

8.3K 次观看.  U.S. Army Edgewood Chemical Biological Center. 在本文中，用于量化在各种材料的化学品的质量传输参数的过程被呈现。这个过程涉及采用一逆分析基于扩散模型为蒸气所记录的实时，质谱法在高真空中发射分布。 

视频: An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological processes. This subject embraces diverse scientific areas, spanning from physical, biological and bioorganic chemistry to biology and medicine, with applications to the amelioration of quality of life, health and aging. Multidisciplinary skills are required for the full investigation of the many facets of radical processes in the biological environment and chemical knowledge plays a crucial role in unveiling basic processes and mechanisms. We developed a chemical biology approach able to connect free radical chemical reactivity with biological processes, providing information on the mechanistic pathways and products. The core of this approach is the design of biomimetic models to study biomolecule behavior (lipids, nucleic acids and proteins) in aqueous systems, obtaining insights of the reaction pathways as well as building up molecular libraries of the free radical reaction products. This context can be successfully used for biomarker discovery and examples are provided with two classes of compounds: mono-trans isomers of cholesteryl esters, which are synthesized and used as references for detection in human plasma, and purine 5',8-cyclo-2'-deoxyribonucleosides, prepared and used as reference in the protocol for detection of such lesions in DNA samples, after ionizing radiations or obtained from different health conditions.

Radical-based biomimetic chemistry has been applied to building-up libraries necessary for biomarker development.

自由基化学生物学的化学行为，生物标记开发

The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological ...

科研

化学

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria

Lipopolysaccharide (LPS) is the major cell surface molecule of gram-negative bacteria, deposited on the outer leaflet of the outer membrane bilayer. LPS can be subdivided into three domains: the distal O-polysaccharide, a core oligosaccharide, and the lipid A domain consisting of a lipid A molecular species and 3-deoxy-D-manno-oct-2-ulosonic acid residues (Kdo). The lipid A domain is the only component essential for bacterial cell survival. Following its synthesis, lipid A is chemically modified in response to environmental stresses such as pH or temperature, to promote resistance to antibiotic compounds, and to evade recognition by mediators of the host innate immune response. The following protocol details the small- and large-scale isolation of lipid A from gram-negative bacteria. Isolated material is then chemically characterized by thin layer chromatography (TLC) or mass-spectrometry (MS). In addition to matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS, we also describe tandem MS protocols for analyzing lipid A molecular species using electrospray ionization (ESI) coupled to collision induced dissociation (CID) and newly employed ultraviolet photodissociation (UVPD) methods. Our MS protocols allow for unequivocal determination of chemical structure, paramount to characterization of lipid A molecules that contain unique or novel chemical modifications. We also describe the radioisotopic labeling, and subsequent isolation, of lipid A from bacterial cells for analysis by TLC. Relative to MS-based protocols, TLC provides a more economical and rapid characterization method, but cannot be used to unambiguously assign lipid A chemical structures without the use of standards of known chemical structure. Over the last two decades isolation and characterization of lipid A has led to numerous exciting discoveries that have improved our understanding of the physiology of gram-negative bacteria, mechanisms of antibiotic resistance, the human innate immune response, and have provided many new targets in the development of antibacterial compounds.

Isolation and characterization of the lipid A domain of lipopolysaccharide (LPS) from gram-negative bacteria provides insight into cell surface based mechanisms of antibiotic resistance, bacterial survival and fitness, and how chemically diverse lipid A molecular species differentially modulate host innate immune responses.

隔离和脂质A的化学表征革兰氏阴性菌

Lipopolysaccharide (LPS) is the major cell surface molecule of gram-negative bacteria, deposited on the outer leaflet of the outer membrane bilayer. LPS ...

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in traditional materials, including low cost and mechanical flexibility. In a similar vein, it would be advantageous to expand the use of organics into high frequency electronics and spin-based electronics. This work presents a synthetic process for the growth of thin films of the room temperature organic ferrimagnet, vanadium tetracyanoethylene (V[TCNE]x, x~2) by low temperature chemical vapor deposition (CVD). The thin film is grown at &#60;60 &#176;C, and can accommodate a wide variety of substrates including, but not limited to, silicon, glass, Teflon and flexible substrates. The conformal deposition is conducive to pre-patterned and three-dimensional structures as well. Additionally this technique can yield films with thicknesses ranging from 30 nm to several microns. Recent progress in optimization of film growth creates a film whose qualities, such as higher Curie temperature (600 K), improved magnetic homogeneity, and narrow ferromagnetic resonance line-width (1.5 G) show promise for a variety of applications in spintronics and microwave electronics.

We present the synthesis of the organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]x, x~2) via low temperature chemical vapor deposition (CVD). This optimized recipe yields an increase in Curie temperature from 400 K to over 600 K and a dramatic improvement in magnetic resonance properties.

化学气相沉积的有机磁体，钒四氰

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

超分子胶体的合成与表征

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Glycan Node Analysis: A Bottom-up Approach to Glycomics

Synthesized in a non-template-driven process by enzymes called glycosyltransferases, glycans are key players in various significant intra- and extracellular events. Many pathological conditions, notably cancer, affect gene expression, which can in turn deregulate the relative abundance and activity levels of glycoside hydrolase and glycosyltransferase enzymes. Unique aberrant whole glycans resulting from deregulated glycosyltransferase(s) are often present in trace quantities within complex biofluids, making their detection difficult and sometimes stochastic. However, with proper sample preparation, one of the oldest forms of mass spectrometry (gas chromatography-mass spectrometry, GC-MS) can routinely detect the collection of branch-point and linkage-specific monosaccharides ("glycan nodes") present in complex biofluids. Complementary to traditional top-down glycomics techniques, the approach discussed herein involves the collection and condensation of each constituent glycan node in a sample into a single independent analytical signal, which provides detailed structural and quantitative information about changes to the glycome as a whole and reveals potentially deregulated glycosyltransferases. Improvements to the permethylation and subsequent liquid/liquid extraction stages provided herein enhance reproducibility and overall yield by facilitating minimal exposure of permethylated glycans to alkaline aqueous conditions. Modifications to the acetylation stage further increase the extent of reaction and overall yield. Despite their reproducibility, the overall yields of N-acetylhexosamine (HexNAc) partially permethylated alditol acetates (PMAAs) are shown to be inherently lower than their expected theoretical value relative to hexose PMAAs. Calculating the ratio of the area under the extracted ion chromatogram (XIC) for each individual hexose PMAA (or HexNAc PMAA) to the sum of such XIC areas for all hexoses (or HexNAcs) provides a new normalization method that facilitates relative quantification of individual glycan nodes in a sample. Although presently constrained in terms of its absolute limits of detection, this method expedites the analysis of clinical biofluids and shows considerable promise as a complementary approach to traditional top-down glycomics.

This article presents an enhanced form of a novel bottom-up glycomics technique designed to analyze the pooled compositional profile of glycans in unfractionated biofluids through the chemical breakdown of glycans into their constituent linkage-specific monosaccharides for detection by GC-MS. Potential applications include early detection of cancer and other glycan-affective disorders.

聚糖节点分析：自下而上的方法，以糖原组学

Synthesized in a non-template-driven process by enzymes called glycosyltransferases, glycans are key players in various significant intra- and ...

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. Herein, we introduce a microfluidic-based technology, employing a double-layer microfluidic device, which can trap and localize in situ and ex situ synthesized structures on microfluidic channel surfaces. Crucially, we show how such a device can be used to conduct controlled chemical reactions onto on-chip trapped structures and we demonstrate how the synthetic pathway of a crystalline molecular material and its positioning inside a microfluidic channel can be precisely modified with this technology. This approach provides new opportunities for the controlled assembly of structures on surface and for their subsequent treatment.

Herein, we describe the fabrication and operation of a double-layer microfluidic system made of polydimethylsiloxane (PDMS). We demonstrate the potential of this device for trapping, directing the coordination pathway of a crystalline molecular material and controlling chemical reactions onto on-chip trapped structures.

微流控气动笼：在芯片水晶捕获，处理的新方法和控制化学处理

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. ...

Original Experimental Approach for Assessing Transport Fuel Stability

The study of fuel oxidation stability is an important issue for the development of future fuels. Diesel and kerosene fuel systems have undergone several technological changes to fulfill environmental and economic requirements. These developments have resulted in increasingly severe operating conditions whose suitability for conventional and alternative fuels needs to be addressed. For example, fatty acid methyl esters (FAMEs) introduced as biodiesel are more prone to oxidation and may lead to deposit formation. Although several methods exist to evaluate fuel stability (induction period, peroxides, acids, and insolubles), no technique allows one to monitor the real-time oxidation mechanism and to measure the formation of oxidation intermediates that may lead to deposit formation. In this article, we developed an advanced oxidation procedure (AOP) based on two existing reactors. This procedure allows the simulation of different oxidation conditions and the monitoring of the oxidation progress by the means of macroscopic parameters, such as total acid number (TAN) and advanced analytical methods like gas chromatography coupled to mass spectrometry (GC-MS) and Fourier Transform Infrared - Attenuated Total Reflection (FTIR-ATR). We successfully applied AOP to gain an in-depth understanding of the oxidation kinetics of a model molecule (methyl oleate) and commercial diesel and biodiesel fuels. These developments represent a key strategy for fuel quality monitoring during logistics and on-board utilization.

Oxidation stability of transport fuels has become a concern for future fuel development. This work presents an original methodology developed by IFP Energies Nouvelles for assessing fuel stability using two different reactors. This methodology was successfully applied to gain an in-depth understanding of the oxidation kinetics and pathways of model molecules and commercial fuels.

评定运输燃料的稳定性原始实验方法

The study of fuel oxidation stability is an important issue for the development of future fuels. Diesel and kerosene fuel systems have undergone several ...

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic acids containing three to six carbons), such as malate and citrate, are critical to the proper functioning of many biological systems, where they function in cellular respiration and can serve as indicators of cell health. In foods, organic acid content can have significant impact on taste, with increased SCCA levels resulting in a sour or &#34;acid&#34; taste. Because of this, methods for the rapid analysis of organic acid levels are of particular interest to the food and beverage industries. Unfortunately, however, most methods used for SCCA quantification are dependent on time-consuming protocols requiring the derivatization of samples with hazardous reagents, followed by costly chromatographic and/or mass spectrometric analyses. This method details an alternate method for the detection and quantification of organic acids from plant material and food samples using free zonal capillary electrophoresis (CZE), sometimes simply referred to as capillary electrophoresis (CE). CZE provides a cost-effective method for measuring SCCAs with a low limit of detection (0.005 mg/ml). This article details the extraction and quantification of SCCAs from plant samples. While the method provided focuses on measurement of SCCAs from coffee beans, the method provided can be applied to multiple plant-based food materials.

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

This article presents a method for the detection and quantification of organic acids from plant material using free zonal capillary electrophoresis. An example of the potential application of this method, determining the effects of a secondary fermentation on organic acid levels in coffee seeds, is provided.

利用毛细管电泳从植物组织量化有机酸：一个测试用例检查<em&gt;小粒种咖啡</em&gt;种子

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic ...

Characterizing Electron Transport through Living Biofilms

Here we demonstrate the method of electrochemical gating used to characterize electrical conductivity of electrode-grown microbial biofilms under physiologically relevant conditions.1 These measurements are performed on living biofilms in aqueous medium using source and drain electrodes patterned on a glass surface in a specialized configuration referred to as an interdigitated electrode (IDA) array. A biofilm is grown that extends across the gap connecting the source and drain. Potentials are applied to the electrodes (ES and ED) generating a source-drain current (ISD) through the biofilm between the electrodes. The dependency of electrical conductivity on gate potential (the average of the source and drain potentials, EG = [ED + ES]/2) is determined by systematically changing the gate potential and measuring the resulting source-drain current. The dependency of conductivity on gate potential provides mechanistic information about the extracellular electron transport process underlying the electrical conductivity of the specific biofilm under investigation. The electrochemical gating measurement method described here is based directly on that used by M. S. Wrighton2,3 and colleagues and R. W. Murray4,5,6 and colleagues in the 1980&#39;s to investigate thin film conductive polymers.

A protocol for measuring electrical conductivity of living microbial biofilms under physiologically relevant conditions is presented.

通过活生物膜表征电子传输

Here we demonstrate the method of electrochemical gating used to characterize electrical conductivity of electrode-grown microbial biofilms under ...

Pretargeted Radioimmunotherapy Based on the Inverse Electron Demand Diels-Alder Reaction

While radioimmunotherapy (RIT) is a promising approach for the treatment of cancer, the long pharmacokinetic half-life of radiolabeled antibodies can result in high radiation doses to healthy tissues. Perhaps not surprisingly, several different strategies have been developed to circumvent this troubling limitation. One of the most promising of these approaches is pretargeted radioimmunotherapy (PRIT). PRIT is predicated on decoupling the radionuclide from the immunoglobulin, injecting them separately, and then allowing them to combine in vivo at the target tissue. This approach harnesses the exceptional tumor-targeting properties of antibodies while skirting their pharmacokinetic drawbacks, thereby lowering radiation doses to non-target tissues and facilitating the use of radionuclides with half-lives that are considered too short for use in traditional radioimmunoconjugates. Over the last five years, our laboratory and others have developed an approach to in vivo pretargeting based on the inverse electron-demand Diels-Alder (IEDDA) reaction between trans-cyclooctene (TCO) and tetrazine (Tz). This strategy has been successfully applied to pretargeted positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging with a variety of antibody-antigen systems. In a pair of recent publications, we have demonstrated the efficacy of IEDDA-based PRIT in murine models of pancreatic ductal adenocarcinoma and colorectal carcinoma. In this protocol, we describe protocols for PRIT using a 177Lu-DOTA-labeled tetrazine radioligand ([177Lu]Lu-DOTA-PEG7-Tz) and a TCO-modified variant of the colorectal cancer targeting huA33 antibody (huA33-TCO). More specifically, we will describe the construction of huA33-TCO, the synthesis and radiolabeling of [177Lu]Lu-DOTA-PEG7-Tz, and the performance of in vivo biodistribution and longitudinal therapy studies in murine models of colorectal carcinoma.

This protocol describes the synthesis and characterization of a trans-cyclooctene (TCO)-modified antibody and a 177Lu-labeled tetrazine (Tz) radioligand for pretargeted radioimmunotherapy (PRIT). In addition, it details the use of these two constructs for in vivo biodistribution and longitudinal therapy studies in a murine model of colorectal cancer.

基于逆电子需求函数-alder 反应的隐形放射免疫治疗

While radioimmunotherapy (RIT) is a promising approach for the treatment of cancer, the long pharmacokinetic half-life of radiolabeled antibodies can ...