The authors thank Prof. Peter Imming and Diana M&#252;ller for synthesis of the Trityl spin probe and Prof. Sebastian Polarz, Martin Wessig and Andreas Schachtschneider for the synthesis of the porous materials. Financial support by the DFG (DR 743/7-1) and within the SPP 1570 is gratefully acknowledged.

注意:使用前请咨询所有相关的材料安全数据表（MSDS）。如果吞入或吸入酒精是有害的，它是易燃的。 1.优化的连续波（CW）EPR参数<ol><li>在1mM的浓度制备的乙醇IPSL的40微升（PA）。 </li><li>取吸管控制器和填充的毛细管与IPSL溶液至2厘米的填充高度。溶液1厘米进一步拉入毛细管使得存在的溶液下方的空气间隙。密封与毛细管密封胶两端的毛细血管。气隙可以防止密封剂的成分扩散到样品。 </li><li>以1cm从毛细管的上下端部的距离环绕毛细管约5厘米长的聚四氟乙烯（PTFE）胶带的两个条带。 </li><li>把毛细管导入的EPR样品管（4内径）。确保PTFE带保持毛细管固定在样品管的中心轴。推毛细管下降到样品管的底部。 </li><li>把样品到谐振器和中心谐振器内的自旋标记物溶液。 </li><li>调通过以下在光谱仪说明手册分光计为临界耦合。 </li><li>初步光谱仪设置<ol><li>使用微波频率设置中心场B使用下式 <img alt="式（1）" src="/files/ftp_upload/54335/54335eq1.jpg" /> 其中g≈2.003为不成对自由基在氮氧化物自旋标记的g因子的粗略估计，h是普朗克常数和μB是玻尔磁。 </li><li>建立一个新的实验"field_sweep"与磁场为横坐标，信号强度为纵坐标。使用下面的参数:Centerfield如在先前步骤中，扫描宽度计算值:400 G，modulati振幅:0.8 G，调制频率:100kHz，微波衰减30分贝点数:2048，扫描次数:1，扫描时间:80秒，时间常数:50毫秒。 </li><li>激活设置扫描模式。对于设置扫描时间常数，选择最低值，光谱仪的优惠。调节接收机增益的值，其中所显示的信号填充显示强度范围的80％，因此，即使有噪声没有数据点具有比最大的80％的较高的强度。禁用设置扫描之后。 </li><li>按"运行"按钮。 </li><li>读出的过零点，从得到的频谱的中心峰的字段值。中间字段设置为该值。 </li><li>就拿水平线工具，测量从点谱宽，其中最左边的峰值开始上升基线水平之上的地步，最右边的峰值返回到基线水平。 </li><li>设置扫描宽度的三倍光谱宽度。 </li></ol></li><li>重新计算谱仪参数<ol><li>计算扫描时间:扫描宽度/扫描速度。使用5 G /秒的扫描速度。 </li><li>计算数据点的最小数目:10 *扫描宽度/线条宽度。 </li><li>计算转换时间:扫描时间/数据点的数目。 </li><li>计算时间常数:0.1 *行宽*扫描时间/扫描宽度。 </li></ol></li><li>衡量一个饱和曲线，以确定最佳微波功率<ol><li>将微波衰减为10 dB，按步骤1.7.3描述调节接收机增益。 </li><li>设置微波衰减到50分贝，记录光谱。如果信噪比低于5:1，增加扫描次数。重复此步骤直到信噪比为5:1或更大。 </li><li>创建新的实验"饱和"使用磁场为横坐标1，微波功率为横坐标2和信号强度作为纵轴。从日复制所有设置E"field_sweep"的实验步骤1.9.2。为横坐标2，微波衰减的开始值设置为10分贝的增量的值为1 dB和点至41以覆盖范围为10分贝至50分贝数。运行实验。 </li><li>创建饱和曲线的电子表格。插入以dB微波衰减到第一列。 </li><li>计算出微波功率的平方根中的Au在与式第二列 <img alt="公式（2）" src="/files/ftp_upload/54335/54335eq2.jpg" /> 其中x是从第一塔以dB微波衰减。 </li><li>使用分光计软件来测量峰峰值为在实验中每个微波衰减的中心谱线的强度。编写强度到电子表格中的第三列。 </li><li>绘制对峰峰值强度（针对2栏第3栏）的微波功率的平方根以获得饱和曲线。 Inclu在德积原点（0,0）。 </li><li>识别饱和曲线的线性状态。最佳微波功率是最高的微波功率是仍处于线性状态。使用相应的衰减设置为所有进一步的实验。 </li></ol></li></ol> 2.确定磁场梯度强度和时间分辨率<ol><li>创建与磁场为横坐标1和信号强度作为纵轴分光计软件新的实验。使梯度线圈控制。 </li><li>从在1.8和1.9.8确定之前的实验复制所有光谱仪的设置。 </li><li>设置磁场梯度强度170克/厘米的朝上样品轴的方向。 </li><li>计算扫描宽度SW = SW 0 + FOV·G，其中SW 0是在1.8.4在不存在磁场梯度的确定的扫描宽度，FOV 是视场（2.5厘米）和G是磁场梯度强度。 </li><li>计算估计像素尺寸=线宽/ G，采用在不存在磁场梯度的记录在1.9.3频谱的线宽。 </li><li>计算扫描时间= SW /扫描速度。使用相同的扫描速度为1.8.1。 </li><li>计算需要使用更高的值的数据点的最小数量 我。N + 1 = 10 *扫描宽度/线宽 二，N 2 = 10 *视图/（G *像素大小）的领域。 </li><li>计算转换时间:扫描时间/数据点的数目。 </li><li>计算时间常数:0.1 *线宽*扫描时间/扫描宽度或更低。 </li><li>通过2.9设置2.3计算参数，并按下"运行"按钮。 </li><li>测量基准的噪声电平以及峰值强度的峰与垂直线工具的中心线。计算出的信噪比。 </li><li>如果信噪比低于5:1，加倍扫描数在光谱仪的参数的"扫描"面板，并重复步骤2.1.3至2.11。 </li></ol> 3.准备样本注意:戴安全防护眼镜。 注:请溶剂在任何时候都完全淹没气凝胶。参见图2的照片和示意图。 <ol><li>填充直径为10厘米，用乙醇（PA）的培养皿高达5mm的高度。 </li><li>把气凝胶入培养皿和圆柱形一块5毫米切断为1厘米的长度。 </li><li>准备一块热缩管的比所述气凝胶筒长约1厘米。 </li><li>使用玻璃管切刀突破200内径的样品管创建4个厘米长的两件。两件应该有两个开口端。 <br/&gt;注意:操作热风枪时，应戴防护眼镜和合适的手套。不要直接对皮肤或衣服气流和易燃材料保持它拿走。 </li><li>插入该样品管件5 mm深入热缩管的一端中的一个。使用加热枪小心加热热缩管的这一端，而不管的其余部分缩小。该热缩管现在应该固定在玻璃管中。 <ol><li>浸没在气凝胶的培养皿玻璃管和热缩管的这种组合。小心地从步骤3.2推片气凝胶到热缩管的开口端。 </li></ol></li><li>填用乙醇（PA）的试管至7厘米的高度。从培养皿转移样品放入试管。虽然这样做，确保热缩管的开口端是面向上方。确保气凝胶在乙醇中完全淹没。 </li><li>插入第二个4厘米长片从步骤3.4到热缩管的开放端的试样管。不适用的力，重力应该足以关闭气凝胶和样品管段之间的间隙。把试管用样品放入烧杯中。 </li><li>填写一个压力锅至少500毫升乙醇中并加入搅拌棒。 </li><li>把含在高压锅内脚架样品的烧杯中。 注意:执行通风橱内的下一步，继续戴安全防护眼镜。 </li><li>库克和搅拌样品在上述的磁力搅拌器环境压力1巴的压力设置。温度必须至少达到90℃。让它尽快达到的压力和压力阀释放乙醇蒸汽冷却。如果热缩套管没有缩水，重复此步骤。 注:立即清洁压力锅用水，以尽量减少乙醇对密封阀的作用。在这一点上，所制备的样品可以储存在乙醇塞弗拉尔个月。 </li></ol> 4.准备光谱仪<ol><li>创建使用磁场为横坐标1 2d的实验，时间为横坐标2和信号强度为纵坐标，以使得磁场扫描记录每个时间步长。使梯度线圈控制。 </li><li>测量之间的时间延迟设置为零。如在第2组点为时间轴的数量确定为20小时/扫描时间设置其他参数。设置微波桥每个切片扫描后执行微调。 </li><li>按照1.7节的步骤调整光谱仪的空谐振器。 </li></ol> 5.准备测量样本注意:此协议的唯一时间关键步骤是5.3至6.2，它是从与另外的自旋标记物，直到在光谱仪中的数据采集开始时的扩散过程的开始。执行这些步骤，而不会引入任何延误。 <ol><li>把一个手指在样品的顶部从第3保持乙醇溶液从底部流出。然后使用注射器从底部5毫米较低的采样管的移除一些乙醇和密封以管密封化合物这一目的。确保有2毫米的高度密封化合物上方的气泡。 </li><li>从除于3 mm只用巴斯德毛细吸管气凝胶上述气凝胶上述样品管中取出所有乙醇。 </li><li>注入20微升的自旋标记物溶液中乙醇对气凝胶的顶部。确保不上气凝胶的顶部创建一个气泡。标记当前时间作为扩散过程的开始。 </li><li>放置在样品中有4个内径的样品管中。使用PTFE带居中样本。 </li><li>使用毡尖笔在68毫米气凝胶的上边缘上方的位置来标记所述外样品管中。这有助于在谐振器正确地定心在样品和所说的C谐振器的输入气凝胶的上边缘低于1毫米。 </li></ol> 6.执行扩散实验<ol><li>放置在样品中的谐振器，以使从5.5对准与谐振器和调分光计为如在分光计的操作手册中描述了临界耦合的聚四氟乙烯支架的顶部标记。 </li><li>使用设置扫描模式，如1.7.3所述，而梯度线圈仍然关闭，设置接收机增益。 </li><li>启动已成立了第4节写下当前时间的实验。要么等待20小时的实验，以完成或停止实验时所记录的信号不超过4小时以上的过程中发生变化。保存结果。 </li></ol> 7.执行数据分析所需的附加实验注:扩散试验后直接和不与莫相同的样品进行实验，在7.1和7.2咏样品。 <ol><li>记录为反卷积点扩散函数<ol><li>从步骤1.7.2切换到"扫场"实验。复制在步骤6从实验的所有设置。 </li><li>记录的光谱和测量的信噪比。如果它小于20:1，增加扫描次数，并重复此工序。否则，保存光谱。 </li></ol></li><li>执行2D成像实验<ol><li>创建与磁场分光计新实验为横坐标1，磁场梯度为横坐标2的角度和信号强度作为纵轴。的参数从步骤6.成像平面设置于YZ平面，这是包括静态磁场B 0的方向和样品轴的平面复制。 </li><li>设置渐变方向到N = FOV /所需的像素尺寸或更高氮角度的数量。 </li><li>开始测量并保存结果。 </li><li>重复次7.1Ë步骤，并保存结果。 </li></ol></li><li>测量谐振器灵敏度分布<ol><li>通过重复步骤1.1至1.5制备在溶液旋探针的另一样品，但这次加入4厘米溶液进入毛细管代替2厘米。 </li><li>跟随在第2步骤记录的样品的光谱与样品轴的方向的磁场梯度。对于步进2.3，使用的角度为3厘米的字段。保存结果。 </li><li>重复测量在不存在磁场梯度的和保存的结果。 </li></ol></li></ol> 8.数据分析<ol><li>重建二维成像实验<ol><li>从装载7.2.3二维成像实验到光谱仪软件的主视窗。 </li><li>从装载7.2.4实验到光谱仪软件的二次视口。 </li><li>去处理&gt;变换&gt;解卷积，选择切片:所有并点击适用于执行反卷积。 </li><li>去卷积的数据保存到磁盘。 </li><li>用下面的命令使用免费提供的图像重建软件20:重建--input result_from_8_1_4.DSC --output reconstructed_image.DSC --steps 100 --size 256 </li><li>从8.1.5加载结果到光谱仪的软件以供日后参考。 </li></ol></li><li>分析记录的扩散试验<ol><li>启动数据分析软件，进入到图3中所示的软件的"装载"标签。从步骤6.3下"扩散试验"装入扩散实验。负载下的"扩散试验W / O梯度"步骤7.1.2对应的点扩散函数。从步骤7.3.2下的"谐振器简介实验"并从步骤7.3.3下的"谐振腔轮廓EXP W / O梯度"的结果，将结果。 </li><li>转到图4中所示的谐振器敏感度标签</s仲&gt;使用7.3.3点扩散函数从实验7.3.2执行数据的卷积。降低噪声功率值，直到结果是嘈杂，然后将其抬，直到噪音刚好消失。 </li><li>去，以便从7.1去卷积使用实验记录在6.2每个场扫描为点扩展函数在图5所示的一维的自旋密度分布标签。降低噪声功率值，直到结果是嘈杂，然后将其抬，直到噪音刚好消失。 </li><li>切换到如图6所示的作物面积选项卡，选中完全位于气凝胶在那里旋转探头正要从上面在该地区的第一时间步进入和内部扩散热图的区域。如果有疑问，从8.1.6加载重建图像光谱仪软件，以帮助识别气凝胶的确切位置。 </li><li>从步骤8.2在样品的向下方向增加的区域，使得没有自旋概率Ë到达的区域的实验时间内的下边界。参见图6，以供参考。 </li><li>切换到图7和压配合所示的涌入标签。左边的面板显示剪切区域从8.2.5沿位置轴的积分。 </li><li>验证中间面板所示的曲线从零开始，并立即开始上升。如果不是的话，回去8.2.5。 </li><li>验证中间面板中显示的红线后面的黑色数据点。 </li></ol></li><li>模拟一维自旋浓度随时间和合适的扩散系数<ol><li>切换到扩散系数选项卡，压配合。 </li><li>等待的计算的结果。 </li><li>验证左侧所示的实验数据显示在右边的数字数据相匹配。 </li><li>阅读翻译宏观扩散系数D 宏的值是DISPLAYED在屏幕上。 </li></ol></li></ol>

<ol>
	<li>Sch&#252;th, F., Sing, K. S. W., Weitkamp, 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> Handbook of Porous Solids. , (2002).</li><li>Hoffmann, F., Cornelius, M., Morell, J., Fr&#246;ba, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silica-Based+Mesoporous+Organic-Inorganic+Hybrid+Materials.">Silica-Based Mesoporous Organic-Inorganic Hybrid Materials.</a> Angew. Chem. Int. Edit. 45 (20), 3216-3251 (2006).</li><li>Sanchez, C., Boissi&#232;re, C., Grosso, D., Laberty, C., Nicole, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design,+Synthesis,+and+Properties+of+Inorganic+and+Hybrid+Thin+Films+Having+Periodically+Organized+Nanoporosity.">Design, Synthesis, and Properties of Inorganic and Hybrid Thin Films Having Periodically Organized Nanoporosity.</a> Chem. of Mat. 20 (3), 682-737 (2008).</li><li>Le Bihan, D., Johansen-Berg, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+MRI+at+25:+Exploring+brain+tissue+structure+and+function.">Diffusion MRI at 25: Exploring brain tissue structure and function.</a> NeuroImage. 61 (2), 324-341 (2012).</li><li>Pregosin, P. S., Kumar, P. G. A., Fern&#225;ndez, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+Gradient+Spin&#8722;Echo+(PGSE)+Diffusion+and+1H,19F+Heteronuclear+Overhauser+Spectroscopy+(HOESY)+NMR+Methods+in+Inorganic+and+Organometallic+Chemistry:+Something+Old+and+Something+New.">Pulsed Gradient Spin&#8722;Echo (PGSE) Diffusion and 1H,19F Heteronuclear Overhauser Spectroscopy (HOESY) NMR Methods in Inorganic and Organometallic Chemistry: Something Old and Something New.</a> Chem. Rev. 105 (8), 2977-2998 (2005).</li><li>Talmon, Y., 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=Molecular+diffusion+in+porous+media+by+PGS+ESR.">Molecular diffusion in porous media by PGS ESR.</a> Phys. Chem. Chem. Phys. 12 (23), 5998-6007 (2010).</li><li>Okazaki, M., Seelan, S., Toriyama, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Condensation+process+of+alcohol+molecules+on+mesoporous+silica+MCM-41+and+SBA-15+and+fumed+silica:+a+spin-probe+ESR+study.">Condensation process of alcohol molecules on mesoporous silica MCM-41 and SBA-15 and fumed silica: a spin-probe ESR study.</a> Appl. Magn. Reson. 35 (3), 363-378 (2009).</li><li>Wessig, M., Spitzbarth, M., Drescher, M., Winter, R., Polarz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+scale+investigation+of+molecular+diffusion+inside+functionalized+porous+hosts+using+a+combination+of+magnetic+resonance+methods.">Multiple scale investigation of molecular diffusion inside functionalized porous hosts using a combination of magnetic resonance methods.</a> Phys. Chem. Chem. Phys. 17 (24), 15976-15988 (2015).</li><li>Yakimchenko, O. E., Degtyarev, E. N., Parmon, V. N., Lebedev, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+in+Porous+Catalyst+Grains+as+Studied+by+EPR+Imaging.">Diffusion in Porous Catalyst Grains as Studied by EPR Imaging.</a> J. Phys. Chem. 99 (7), 2038-2041 (1995).</li><li>Cleary, D. A., Shin, Y. K., Schneider, D. J., Freed, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+determination+of+translational+diffusion+coefficients+using+ESR+imaging.">Rapid determination of translational diffusion coefficients using ESR imaging.</a> J. Magn. Reson. 79 (3), 474-492 (1988).</li><li>Hornak, J. P., Moscicki, J. K., Schneider, D. J., Freed, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+coefficients+in+anisotropic+fluids+by+ESR+imaging+of+concentration+profiles.">Diffusion coefficients in anisotropic fluids by ESR imaging of concentration profiles.</a> J. Chem. Phys. 84 (6), 3387-3395 (1986).</li><li>Berliner, L. J., Fujii, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EPR+imaging+of+diffusional+processes+in+biologically+relevant+polymers.">EPR imaging of diffusional processes in biologically relevant polymers.</a> J. Magn. Reson. 69 (1), 68-72 (1986).</li><li>Degtyarev, Y. N., Schlick, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+Coefficients+of+Small+Molecules+as+Guests+in+Various+Phases+of+Pluronic+L64+Measured+by+One-Dimensional+Electron+Spin+Resonance+Imaging.">Diffusion Coefficients of Small Molecules as Guests in Various Phases of Pluronic L64 Measured by One-Dimensional Electron Spin Resonance Imaging.</a> Langmuir. 15 (15), 5040-5047 (1999).</li><li>Marek, A., Labsk&#253;, J., Ko&#328;&#225;k, &. #. 2. 6. 8. ;., Pila&#345;, J., Schlick, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Translational+Diffusion+of+Paramagnetic+Tracers+in+HEMA+Gels+and+in+Concentrated+Solutions+of+PolyHEMA+by+1D+Electron+Spin+Resonance+Imaging.">Translational Diffusion of Paramagnetic Tracers in HEMA Gels and in Concentrated Solutions of PolyHEMA by 1D Electron Spin Resonance Imaging.</a> Macromolecules. 35 (14), 5517-5528 (2002).</li><li>Shin, Y. K., Ewert, U., Budil, D. E., Freed, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microscopic+versus+macroscopic+diffusion+in+model+membranes+by+electron+spin+resonance+spectral-spatial+imaging.">Microscopic versus macroscopic diffusion in model membranes by electron spin resonance spectral-spatial imaging.</a> Biophys. J. 59 (4), 950-957 (1991).</li><li>Spitzbarth, M., 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=Simultaneous+Monitoring+of+Macroscopic+and+Microscopic+Diffusion+of+Guest+Molecules+in+Silica+and+Organosilica+Aerogels+by+Spatially+and+Time-Resolved+Electron+Paramagnetic+Resonance+Spectroscopy.">Simultaneous Monitoring of Macroscopic and Microscopic Diffusion of Guest Molecules in Silica and Organosilica Aerogels by Spatially and Time-Resolved Electron Paramagnetic Resonance Spectroscopy.</a> J. Phys. Chem. C. 119 (30), 17474-17479 (2015).</li><li>Kruczala, K., Schlick, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+Diffusion+Coefficients+of+Nitroxide+Radicals+in+Heterophasic+Propylene&#8722;Ethylene+Copolymers+by+Electron+Spin+Resonance+Imaging.">Measuring Diffusion Coefficients of Nitroxide Radicals in Heterophasic Propylene&#8722;Ethylene Copolymers by Electron Spin Resonance Imaging.</a> Macromolecules. 44 (2), 325-333 (2011).</li><li>Wessig, M., Drescher, M., Polarz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+Functional+Group+Specific+Surface+Interactions+in+Porous+Solids+Using+ESR+Spectroscopy+as+a+Sensitive+and+Quantitative+Tool.">Probing Functional Group Specific Surface Interactions in Porous Solids Using ESR Spectroscopy as a Sensitive and Quantitative Tool.</a> The J. Phys. Chem. C. 117 (6), 2805-2816 (2013).</li><li>Kuschel, A., Polarz, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organosilica+Materials+with+Bridging+Phenyl+Derivatives+Incorporated+into+the+Surfaces+of+Mesoporous+Solids.">Organosilica Materials with Bridging Phenyl Derivatives Incorporated into the Surfaces of Mesoporous Solids.</a> Adv. Funct. Mater. 18 (8), 1272-1280 (2008).</li><li>Spitzbarth, M., Drescher, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+iterative+reconstruction+technique+software+for+spectral-spatial+EPR+imaging.">Simultaneous iterative reconstruction technique software for spectral-spatial EPR imaging.</a> J. Magn. Reson. 257, 79-88 (2015).</li><li>Stoll, S., Schweiger, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EasySpin,+a+comprehensive+software+package+for+spectral+simulation+and+analysis+in+EPR.">EasySpin, a comprehensive software package for spectral simulation and analysis in EPR.</a> J. Magn. Reson. 178 (1), 42-55 (2006).</li></ol>

作者什么都没有透露。

该协议允许顺位分子的扩散的监控。一维成像方法已被选中，是因为它允许较高的时间分辨率相比，2D或3D成像。一维方式需要样品的恒定横截面面积，因为所获得的一维图像的强度不仅取决于浓度，而且在样品上的横截面面积。该方法还要求在样品内的自旋探头的EPR谱只在强度上而不是在形状改变。否则更耗时的谱空间成像，必须使用，这是本方案的范围之外。该方法也只限于系统，其中...

多孔材料发挥在实际应用中，如催化和层析1的主要作用。通过添加表面基团以及调整孔尺寸和表面特性，所述材料可以根据所需的应用程序2,3。多孔材料的功能关键取决于细孔内客体分子的扩散性能。在多孔材料，必须区分微观平移扩散常数D 微 ，它描述在一方面分子长度规模和宏观平移扩散常数D 宏扩散之间进行 另一方面，这是由扩散通过多个细孔，晶界，扭曲和材料的不均匀性的影响。 有几种磁共振方法可用来研究扩散，每个适合的一部分icular尺度。在毫米刻度，核磁共振（NMR）成像4和电子顺磁共振（EPR）成像（如在此协议提交）都可以使用。较小尺度成为通过使用核磁共振脉冲磁场梯度以及EPR实验5,6的访问。在纳米尺度，EPR谱可以通过观察自旋探针7,8之间海森堡交换作用的变化来使用。使用EPR成像范围从工业催化剂支持平移扩散， 例如，氧化铝9，研究各向异性取得高分子凝胶12流体10,11，药物释放系统- 14和膜模型15。 该协议使用EPR成像监测圆柱形spin探测器的宏观动扩散，多孔介质在原地的做法提出了一个。它展示了由日的主机 - 客户系统Ë氮氧spin探测器3-（2-Iodoacetamido）-2,2,5,5-四甲基-1-吡咯烷（IPSL）作为周期性中孔有机二氧化矽内客（PMO）UKON1-GEL气凝胶作为主机和乙醇作为溶剂。该协议已成功以前使用16比较维宏 作为测定用的EPR成像以D 微主机材料UKON1 -凝胶和硅胶和旅客的物种IPSL和三（8-羧基-2,2,6,6- perdeutero四甲基苯并〔1,2-D :4,5-D&#39;]双（1,3）二硫）甲基（三苯甲基），参见图1。 在基于连续波（CW）的EPR成像17的其它方法，扩散需要分光计以外的地方。与此相反，在这里提出的方法在原位方法使用。一系列的一维自旋密度分布ρ1d的快照（T，γ）是记录一段数小时。在此期间，一个快照是在其他之后拍摄并提供具有约5分钟的时间分辨率的实时扩散图案。 UKON1-GEL和硅胶已在3毫米内径的样品管被合成在文献中描述。16,18,19的UKON1 -凝胶和硅胶合成导致样品的收缩。将样品置于一个热缩管，以防止客体分子从气凝胶和样品管的壁之间移动的内部。这一附加步骤是没有必要的，可以直接在样品管进行合成而不改变它们的大小的样品。气凝胶样品崩溃时，他们干出来的，所以他们必须在溶剂中在任何时候都被淹没。所需要的热缩管的温度比在环境压力的乙醇的沸点。因此该协议描述了使用高压锅的提高沸腾的乙醇点。 该协议包括预先为EPR成像实验和用于监视IPSL自旋探头扩散分光计设置合成UKON1-GEL的样品制备。进行数据分析，在本地编写的软件提供并且描述其使用。从分光计的原始数据可以直接装载。软件计算的空间1d中的自旋密度分布ρ1D（T，γ），并考虑到谐振器灵敏度分布。用户可以选择的气凝胶和一个时间窗口，在其上扩散常数将被确定的区域。然后，该软件确定基于选择扩散方程的边界条件，解决了扩散方程。它支持最小二乘拟合找到维宏其中数值解的实验数据的最佳匹配的值。 ρ1D（T，γ）给出直接访问的浓度，并且不通过样品的横截面的变化的影响。对于维宏访问值的范围 估计16 10 7 /秒之间-12米2 /秒和·10 -9 m 2以下。

<table><tbody><tr><td>X-Band spectrometer</td><td>Bruker</td><td>E580</td><td></td></tr><tr><td>Spectrometer software</td><td>Bruker</td><td>Xepr 2.6b.108</td><td></td></tr><tr><td>gradient coil system</td><td>Bruker</td><td>E540 GCX2</td><td></td></tr><tr><td>imaging resonator</td><td>Bruker</td><td>TMHS 1007</td><td></td></tr><tr><td>micro-classic pipette controller</td><td>Brand</td><td>25900</td><td></td></tr><tr><td>microcapillary ringcaps 50&amp;nbsp;&amp;micro;l</td><td>Hirschmann</td><td>9600150</td><td>inner diameter 0.5 mm</td></tr><tr><td>EPR sample tube 2 mm inner diameter</td><td>Bruker</td><td>ER 221TUB/2</td><td></td></tr><tr><td>EPR sample tube 4 mm inner diameter</td><td>Bruker</td><td>ER 221TUB/4</td><td></td></tr><tr><td>heat-shrink tubing DERAY-IB</td><td>DSG-Canusa</td><td>2210048952</td><td>4.8 mm/2.4 mm, 2:1, 95&amp;nbsp;&amp;deg;C - 200&amp;nbsp;&amp;deg;C</td></tr><tr><td>heat gun</td><td>Bosch</td><td>PHG 600-3</td><td></td></tr><tr><td>PTFE&amp;nbsp; band</td><td>VWR</td><td>332362S</td><td>width 12 mm</td></tr><tr><td>test tube</td><td></td><td></td><td>length 16 cm, diameter 1.5 cm</td></tr><tr><td>beaker</td><td></td><td></td><td>250 ml, height 9 cm, diameter 7 cm</td></tr><tr><td>capillary tube sealing</td><td>Fisher Scientific</td><td>02-678</td><td></td></tr><tr><td>pressure cooker, 3 L with trivet</td><td>Beem</td><td>Vital-X-Press V2, F1000675</td><td></td></tr><tr><td>magnetic stirrer with heating element</td><td></td><td></td><td></td></tr><tr><td>ethanol (p.a.)</td><td></td><td></td><td></td></tr><tr><td>ethanol (techn.)</td><td></td><td></td><td></td></tr><tr><td>syringe</td><td>Hamilton</td><td>1705</td><td>0.05 ml, custom length: 20 cm</td></tr><tr><td>Pasteur capillary pipette</td><td></td><td></td><td>length 23 cm</td></tr><tr><td>data analysis software</td><td>homemade</td><td></td><td>Available for download at http://www.uni-konstanz.de/drescher/software. Requires Matlab.</td></tr><tr><td>UKON1-GEL</td><td>kindly provided by Prof. Sebastian Polarz, Martin Wessig and Andreas Schachtschneider&amp;nbsp;</td><td></td><td>See references 16, 18, 19 for the synthesis</td></tr></tbody></table>

in situ monitoring of diffusion of guest molecules in porous media using electron paramagnetic resonance imaging

A method is demonstrated to monitor macroscopic translational diffusion using electron paramagnetic resonance (EPR) imaging. A host-guest system with nitroxide spin probe 3-(2-Iodoacetamido)-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (IPSL) as a guest inside the periodic mesoporous organosilica (PMO) aerogel UKON1-GEL as a host and ethanol as a solvent is used as an example to describe the protocol. Data is shown from a previous publication, where the protocol has been applied to both IPSL and Tris(8-carboxy-2,2,6,6-perdeutero-tetramethyl-benzo[1,2-d:4,5-d&#8242;]bis(1,3)dithiole) methyl (Trityl) as guest molecules and UKON1-GEL and SILICA-GEL as host systems. 
A method is shown to prepare aerogel samples that cannot be synthesized directly in the sample tube for measurement due to a size change during synthesis. The aerogel is attached to sample tubes using heat shrink tubing and a pressure cooker to reach the necessary temperature without evaporating the solvent in the process. The method does not assume a clearly defined initial distribution of guest molecules at the start of the measurement. Instead, it requires a reservoir on top of the aerogel and experimentally determines the influx rate during data analysis.
The diffusion is monitored continually over a period of 20 hr by recording the 1d spin density profile within the sample. The spectrometer settings for the imaging experiment are described quantitatively. Data analysis software is provided to take the resonator sensitivity profile into account and to numerically solve the diffusion equation. The software determines the macroscopic translational diffusion coefficient by least square minimization of the difference between the experiment and the numerical solution of the diffusion equation.

收缩管内的气凝胶的照片和示意图示于图2a和2b。在图2c的二维EPR图像清楚地显示了气凝胶的上边缘。气凝胶上述样品管内ρ1d的强度是低虽然自旋探针的浓度是在至少高达气凝胶内。然而，垂直于图象平面的样本深度是由于样品管的小内径小得多。注意，EPR图像还示出在该样品管无气泡和气凝胶似乎不具有热收缩管的收?...

Watch this Scientific Journal Video about In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging at JoVE.com

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging

A protocol for the in situ monitoring of the diffusion of guest molecules in porous media using electron paramagnetic resonance (EPR) imaging is presented.

在多孔介质中使用电子顺磁共振成像客体分子扩散的原位监测

A method is demonstrated to monitor macroscopic translational diffusion using electron paramagnetic resonance (EPR) imaging. A host-guest system with ...

in-situ-monitoring-diffusion-guest-molecules-porous-media-using

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging

6.3K 次观看.  Universität Konstanz. A protocol for the in situ monitoring of the diffusion of guest molecules in porous media using electron paramagnetic resonance (EPR) imaging is presented.

视频: In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging

Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring 

Nanomedications can be carried by blood borne monocyte-macrophages into the reticuloendothelial system (RES; spleen, liver, lymph nodes) and to end organs. The latter include the lung, RES, and brain and are operative during human immunodeficiency virus type one (HIV-1) infection. Macrophage entry into tissues is notable in areas of active HIV-1 replication and sites of inflammation. In order to assess the potential of macrophages as nanocarriers, superparamagnetic iron-oxide and/or drug laden particles coated with surfactants were parenterally injected into HIV-1 encephalitic mice. This was done to quantitatively assess particle and drug biodistribution. Magnetic resonance imaging (MRI) test results were validated by histological coregistration and enhanced image processing. End organ disease as typified by altered brain histology were assessed by MRI. The demonstration of robust migration of nanoformulations into areas of focal encephalitis provides '"proof of concept" for the use of advanced bioimaging techniques to monitor macrophage migration. Importantly, histopathological aberrations in brain correlate with bioimaging parameters making the general utility of MRI in studies of cell distribution in disease feasible. We posit that using such methods can provide a real time index of disease burden and therapeutic efficacy with translational potential to humans.

Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring

Bioimaging methods used to assess cell biodistribution of nanoparticles are applicable for therapeutic and diagnostic monitoring of nanoformulated compounds. The methods described herein are sensitive and specific when assessed by histological coregistration. The methodologies provide a translational pathway from rodent to human applications.

注册生物成像，纳米材料可用于诊断和治疗监测

Nanomedications can be carried by blood borne monocyte-macrophages into the reticuloendothelial system (RES; spleen, liver, lymph nodes) and to end ...

科研

生物工程

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow

While the first Electron Paramagnetic Resonance (EPR) studies regarding the effects of oxidation on the structure and stability of carbon radicals date back to the early 1980s the focus of these early papers primarily characterized the changes to the structures under extremely harsh conditions (pH or temperature)1-3. It is also known that paramagnetic molecular oxygen undergoes a Heisenberg spin exchange interaction with stable radicals that extremely broadens the EPR signal4-6. Recently, we reported interesting results where this interaction of molecular oxygen with a certain part of the existing stable radical structure can be reversibly affected simply by flowing a diamagnetic gas through the carbon samples at STP7. As flows of He, CO2, and N2 had a similar effect these interactions occur at the surface area of the macropore system.
This manuscript highlights the experimental techniques, work-up, and analysis towards affecting the existing stable radical nature in the carbon structures. It is hoped that it will help towards further development and understanding of these interactions in the community at large.

Stable radicals that are present in carbon substrates interact with paramagnetic oxygen through a Heisenberg spin exchange. This interaction can be significantly reduced under STP conditions by flowing a diamagnetic gas over the carbon system. This manuscript describes a simple method to characterize the nature of those radicals.

通过电子顺磁共振和校准气体流量探索碳表面的激进性质

While the first Electron Paramagnetic Resonance (EPR) studies regarding the effects of oxidation on the structure and stability of carbon radicals date ...

化学

In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment

This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic probes to provide quantitative information on the chemical tumor microenvironment (TME), including pO2, pH, redox status, concentrations of interstitial inorganic phosphate (Pi), and intracellular glutathione (GSH). In particular, an application of a recently developed soluble multifunctional trityl probe provides unsurpassed opportunity for in vivo concurrent measurements of pH, pO2 and Pi in Extracellular space (HOPE probe). The measurements of three parameters using a single probe allow for their correlation analyses independent of probe distribution and time of the measurements.

In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment

Low-field (L-band, 1.2 GHz) electron paramagnetic resonance using soluble nitroxyl and trityl probes is demonstrated for assessment of physiologically important parameters in the tumor microenvironment in mouse models of breast cancer.

体内在肿瘤微环境中 pH 值、 pO2、氧化还原状态、磷酸盐和谷胱甘肽浓度的 EPR 评价

This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic ...

癌症研究

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents

Imaging of hyperpolarized substrates by magnetic resonance shows great clinical promise for assessment of critical biochemical processes in real time. Due to fundamental constraints imposed by the hyperpolarized state, exotic imaging and reconstruction techniques are commonly used. A practical system for characterization of dynamic, multi-spectral imaging methods is critically needed. Such a system must reproducibly recapitulate the relevant chemical dynamics of normal and pathological tissues. The most widely utilized substrate to date is hyperpolarized [1-13C]-pyruvate for assessment of cancer metabolism. We describe an enzyme-based phantom system that mediates the conversion of pyruvate to lactate. The reaction is initiated by injection of the hyperpolarized agent into multiple chambers within the phantom, each of which contains varying concentrations of reagents that control the reaction rate. Multiple compartments are necessary to ensure that imaging sequences faithfully capture the spatial and metabolic heterogeneity of tissue. This system will aid the development and validation of advanced imaging strategies by providing chemical dynamics that are not available from conventional phantoms, as well as control and reproducibility that is not possible in vivo.

A multi-compartment dynamic phantom is used to simulate some biology of interest for metabolic studies using hyperpolarized magnet resonance agents.

一个多腔动态单一酶幻影超极化磁共振剂研究的用途

Imaging of hyperpolarized substrates by magnetic resonance shows great clinical promise for assessment of critical biochemical processes in real time. Due ...

工程学

From Fast Fluorescence Imaging to Molecular Diffusion Law on Live Cell Membranes in a Commercial Microscope

It has become increasingly evident that the spatial distribution and the motion of membrane components like lipids and proteins are key factors in the regulation of many cellular functions. However, due to the fast dynamics and the tiny structures involved, a very high spatio-temporal resolution is required to catch the real behavior of molecules. Here we present the experimental protocol for studying the dynamics of fluorescently-labeled plasma-membrane proteins and lipids in live cells with high spatiotemporal resolution. Notably, this approach doesn&#8217;t need to track each molecule, but it calculates population behavior using all molecules in a given region of the membrane. The starting point is a fast imaging of a given region on the membrane. Afterwards, a complete spatio-temporal autocorrelation function is calculated correlating acquired images at increasing time delays, for example each 2, 3, n repetitions. It is possible to demonstrate that the width of the peak of the spatial autocorrelation function increases at increasing time delay as a function of particle movement due to diffusion. Therefore, fitting of the series of autocorrelation functions enables to extract the actual protein mean square displacement from imaging (iMSD), here presented in the form of apparent diffusivity vs average displacement. This yields a quantitative view of the average dynamics of single molecules with nanometer accuracy. By using a GFP-tagged variant of the Transferrin Receptor (TfR) and an ATTO488 labeled 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine (PPE) it is possible to observe the spatiotemporal regulation of protein and lipid diffusion on &#181;m-sized membrane regions in the micro-to-milli-second time range.

Spatial distribution and temporal dynamics of plasma membrane proteins and lipids is a hot topic in biology. Here this issue is addressed by a spatio-temporal image fluctuation analysis that provides conceptually the same physical quantities of single particle tracking, but it uses small molecular labels and standard microscopy setups.

从快速荧光成像在分子扩散法对活细胞的膜在商业显微镜

It has become increasingly evident that the spatial distribution and the motion of membrane components like lipids and proteins are key factors in the ...

In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework

In situ infrared spectroscopy is an inexpensive, highly sensitive, and selective valuable tool to investigate the interaction of polycrystalline solids with adsorbates. Vibrational spectra provide information on the chemical nature of adsorbed species and their structure. Thus, they are very useful for obtaining molecular level understanding of surface species. The IR spectrum of the sample itself gives some direct information about the material. General conclusions can be drawn concerning hydroxyl groups, some stable surface species and impurities. However, the spectrum of the sample is &#34;blind&#34; with respect to the presence of coordinatively unsaturated ions and gives rather poor information about the acidity of surface hydroxyls, species decisive for the adsorption and catalytic properties of the materials. Furthermore, no discrimination between bulk and surface species can be made. These problems are solved by the use of probe molecules, substances that interact specifically with the surface; the alteration of some spectral features of these molecules as a result of adsorption provides valuable information about the nature, properties, location, concentration, etc., of the surface sites.
The experimental protocol for in-situ IR studies of gas/sample interaction includes preparation of a sample pellet, activation of the material, initial spectral characterization through the analysis of the background spectra, characterization by probe molecules, and study of the interaction with a particular set of gas mixtures. In this paper we investigate a zirconium terephthalate metal organic framework, Zr6O4(OH)4(BDC)6 (BDC = benzene-1,4-dicarboxylate), namely UiO-66 (UiO refers to University of Oslo). The acid sites of the UiO-66 sample are determined by using CO and CD3CN as molecular probes. Furthermore, we have demonstrated that CO2 is adsorbed on basic sites exposed on dehydroxylated UiO-66. Introduction of water to the system produces hydroxyl groups acting as additional CO2 adsorption sites. As a result, CO2 adsorption capacity of the sample is strongly enhanced.

In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework

The use of FTIR spectroscopy for investigation of the surface properties of polycrystalline solids is described. Preparation of sample pellets, activation procedures, characterization with probe molecules and model studies of CO2 adsorption are discussed.

原位FTIR 光谱作为气体/固体相互作用研究工具:UiO-66 金属-有机框架中的水增强 CO2吸附

In situ infrared spectroscopy is an inexpensive, highly sensitive, and selective valuable tool to investigate the interaction of polycrystalline solids ...

Rapid Scan Electron Paramagnetic Resonance Opens New Avenues for Imaging Physiologically Important Parameters In Vivo

We demonstrate a superior method of 2D spectral-spatial imaging of stable radical reporter molecules at 250 MHz using rapid-scan electron-paramagnetic-resonance (RS-EPR), which can provide quantitative information under in vivo conditions on oxygen concentration, pH, redox status and concentration of signaling molecules (i.e., OH&#8226;, NO&#8226;). The RS-EPR technique has a higher sensitivity, improved spatial resolution (1 mm), and shorter acquisition time in comparison to the standard continuous wave (CW) technique. A variety of phantom configurations have been tested, with spatial resolution varying from 1 to 6 mm, and spectral width of the reporter molecules ranging from 16 &#181;T (160 mG) to 5 mT (50 G). A cross-loop bimodal resonator decouples excitation and detection, reducing the noise, while the rapid scan effect allows more power to be input to the spin system before saturation, increasing the EPR signal. This leads to a substantially higher signal-to-noise ratio than in conventional CW EPR experiments.

Rapid Scan Electron Paramagnetic Resonance Opens New Avenues for Imaging Physiologically Important Parameters In Vivo

A new electron paramagnetic resonance (EPR) method, rapid scan EPR (RS-EPR), is demonstrated for 2D spectral spatial imaging which is superior to the traditional continuous wave (CW) technique and opens new venues for in vivo imaging. Results are demonstrated at 250 MHz, but the technique is applicable at any frequency.

快速扫描电子顺磁共振打开新的途径成像生理重要参数<em&gt;在体内</em

We demonstrate a superior method of 2D spectral-spatial imaging of stable radical reporter molecules at 250 MHz using rapid-scan ...

Performing In Situ Closed-Cell Gas Reactions in the Transmission Electron Microscope

Gas reactions studied by in situ electron microscopy can be used to capture the real-time morphological and microchemical transformations of materials at length scales down to the atomic level. In situ closed-cell gas reaction (CCGR) studies performed using (scanning) transmission electron microscopy (STEM) can separate and identify localized dynamic reactions, which are extremely challenging to capture using other characterization techniques. For these experiments, we used a CCGR holder that utilizes microelectromechanical systems (MEMS)-based heating microchips (hereafter referred to as &#34;E-chips&#34;). The experimental protocol described here details the method for performing in situ gas reactions in dry and wet gases in an aberration-corrected STEM. This method finds relevance in many different materials systems, such as catalysis and high-temperature oxidation of structural materials at atmospheric pressure and in the presence of various gases with or without water vapor. Here, several sample preparation methods are described for various material form factors. During the reaction, mass spectra obtained with a residual gas analyzer (RGA) system with and without water vapor further validates gas exposure conditions during reactions. Integrating an RGA with an in situ CCGR-STEM system can, therefore, provide critical insight to correlate gas composition with the dynamic surface evolution of materials during reactions. In situ/operando studies using this approach allow&#160;for detailed investigation of the fundamental reaction mechanisms and kinetics that occur at specific environmental conditions (time, temperature, gas, pressure), in real-time, and at high spatial resolution.

Performing In Situ Closed-Cell Gas Reactions in the Transmission Electron Microscope

Here, we present a protocol for performing in situ TEM closed-cell gas reaction experiments while detailing several commonly used sample preparation methods.

在传输电子显微镜中执行 原位 闭电池气体反应

Gas reactions studied by in situ electron microscopy can be used to capture the real-time morphological and microchemical transformations of materials at ...

Electron Spin Resonance Micro-imaging of Live Species for Oxygen Mapping

This protocol describes an electron spin resonance (ESR) micro-imaging method for three-dimensional mapping of oxygen levels in the immediate environment of live cells with micron-scale resolution1. Oxygen is one of the most important molecules in the cycle of life. It serves as the terminal electron acceptor of oxidative phosphorylation in the mitochondria and is used in the production of reactive oxygen species. Measurements of oxygen are important for the study of mitochondrial and metabolic functions, signaling pathways, effects of various stimuli, membrane permeability, and disease differentiation. Oxygen consumption is therefore an informative marker of cellular metabolism, which is broadly applicable to various biological systems from mitochondria to cells to whole organisms. Due to its importance, many methods have been developed for the measurements of oxygen in live systems. Current attempts to provide high-resolution oxygen imaging are based mainly on optical fluorescence and phosphorescence methods that fail to provide satisfactory results as they employ probes with high photo-toxicity and low oxygen sensitivity. ESR, which measures the signal from exogenous paramagnetic probes in the sample, is known to provide very accurate measurements of oxygen concentration. In a typical case, ESR measurements map the probe's lineshape broadening and/or relaxation-time shortening that are linked directly to the local oxygen concentration. (Oxygen is paramagnetic; therefore, when colliding with the exogenous paramagnetic probe, it shortness its relaxation times.) Traditionally, these types of experiments are carried out with low resolution, millimeter-scale ESR for small animals imaging. Here we show how ESR imaging can also be carried out in the micron-scale for the examination of small live samples. ESR micro-imaging is a relatively new methodology that enables the acquisition of spatially-resolved ESR signals with a resolution approaching 1 micron at room temperature2. The main aim of this protocol-paper is to show how this new method, along with newly developed oxygen-sensitive probes, can be applied to the mapping of oxygen levels in small live samples. A spatial resolution of ~30 x 30 x 100 &mu;m is demonstrated, with near-micromolar oxygen concentration sensitivity and sub-femtomole absolute oxygen sensitivity per voxel. The use of ESR micro-imaging for oxygen mapping near cells complements the currently available techniques based on micro-electrodes or fluorescence/phosphorescence. Furthermore, with the proper paramagnetic probe, it will also be readily applicable for intracellular oxygen micro-imaging, a capability which other methods find very difficult to achieve.

This protocol describes a method for micron-scale three-dimensional imaging of oxygen concentration in the immediate environment of live cells by electron spin resonance microscopy.

电子自旋共振氧测绘活体物种显微成像

This protocol describes an electron spin resonance (ESR) micro-imaging method for three-dimensional mapping of oxygen levels in the immediate environment ...

生物学

<meta charset="utf8"></head><body>使用 EPRI 和超声对肿瘤氧水平进行临床前成像

Tumor Hypoxia Assessment: In Vivo 3D Oxygen Imaging Through Electron Paramagnetic Resonance

The precise and real-time measurement of oxygen partial pressure (pO2) brings valuable information in many pathologies, including cancer. Low tumor pO2 (i.e., hypoxia) is connected to tumor aggressiveness and poor response to therapy. The quantification of tumor pO2 allows the evaluation of treatment effectiveness. Electron Paramagnetic Resonance Imaging (EPRI), particularly Pulse EPRI, has emerged as an advanced three-dimensional (3D) method of assessing tissue oxygenation in vivo. This innovation was enabled by the technological developments in EPR (Electron Paramagnetic Resonance) and the application of the water-soluble oximetric spin probes from the triaryl family, offering fast and sensitive oxygenation data. The relaxation time of the spin probe (T1 and/or T2) provides accurate information about pO2 in selected voxels.
Human glioblastoma LN229 tumors were grown in the interscapular fad pad of BALB/c nude mice. Ultrasound (US) imaging was used as a reference for tumor anatomical information. To image tissue pO2, the animals were placed in a fixed position in the animal bed with fiducials, enabling registration between the imaging modalities. After the OX071 contrast agent was administered, EPRI was performed, followed by US B-mode. Because of the low spin probe toxicity, the procedure can be repeated during tumor growth or treatment. Following imaging, the registration process was carried out using software written in MATLAB. Ultimately, the hypoxic fraction can be calculated for a specific tumor, and the histogram of pO2 tissue distribution can be compared over time. EPRI combined with ultrasound is an excellent tool for oxygen mapping of tumors in the preclinical setting.

<meta charset="utf8"></head><body>肿瘤缺氧评估：通过电子顺磁共振进行体内 3D 氧成像

Quantitative 3D oxygen maps of murine tumors were imaged noninvasively using Pulse Electron Paramagnetic Resonance. Ultrasound B-mode and Power Doppler were used for anatomy and vascular structure. Images from both modalities were superimposed enabling multi-parametric tumor analysis.

肿瘤缺氧评估：通过电子顺磁共振进行体内 3D 氧成像 

The precise and real-time measurement of oxygen partial pressure (pO2) brings valuable information in many pathologies, including cancer. Low tumor pO2 ...

在多孔介质中使用电子顺磁共振成像客体分子扩散的原位监测

摘要

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此视频中的章节

注册生物成像，纳米材料可用于诊断和治疗监测

通过电子顺磁共振和校准气体流量探索碳表面的激进性质

体内在肿瘤微环境中 pH 值、 pO₂、氧化还原状态、磷酸盐和谷胱甘肽浓度的 EPR 评价

一个多腔动态单一酶幻影超极化磁共振剂研究的用途

从快速荧光成像在分子扩散法对活细胞的膜在商业显微镜

原位FTIR 光谱作为气体/固体相互作用研究工具:UiO-66 金属-有机框架中的水增强 CO₂吸附

快速扫描电子顺磁共振打开新的途径成像生理重要参数

在传输电子显微镜中执行原位闭电池气体反应

电子自旋共振氧测绘活体物种显微成像

肿瘤缺氧评估：通过电子顺磁共振进行体内 3D 氧成像

在多孔介质中使用电子顺磁共振成像客体分子扩散的原位监测

摘要

探索更多视频

此视频中的章节

注册生物成像，纳米材料可用于诊断和治疗监测

通过电子顺磁共振和校准气体流量探索碳表面的激进性质

体内在肿瘤微环境中 pH 值、 pO2、氧化还原状态、磷酸盐和谷胱甘肽浓度的 EPR 评价

一个多腔动态单一酶幻影超极化磁共振剂研究的用途

从快速荧光成像在分子扩散法对活细胞的膜在商业显微镜

原位FTIR 光谱作为气体/固体相互作用研究工具:UiO-66 金属-有机框架中的水增强 CO2吸附

快速扫描电子顺磁共振打开新的途径成像生理重要参数

在传输电子显微镜中执行 原位 闭电池气体反应

电子自旋共振氧测绘活体物种显微成像

肿瘤缺氧评估：通过电子顺磁共振进行体内 3D 氧成像

体内在肿瘤微环境中 pH 值、 pO₂、氧化还原状态、磷酸盐和谷胱甘肽浓度的 EPR 评价

原位FTIR 光谱作为气体/固体相互作用研究工具:UiO-66 金属-有机框架中的水增强 CO₂吸附

在传输电子显微镜中执行原位闭电池气体反应