MRI: Acquisition of a field emission scanning electron microscope with cryo transfer and EDS systems

该合同将为康涅狄格大学主校区的多用户电子显微镜实验室（EM Lab）提供资金，用于购买具有低温转移级和能量色散x射线光谱（EDS）系统的场发射扫描电子显微镜（FESEM）。新仪器取代了大量使用了15年的FESEM，从而确保了FESEM的持续可用性，并提供了新的能力，以加强和扩大康涅狄格大学的研究和研究培训。FESEM提供各种材料的图像，其分辨率以前在该设备中无法实现。电荷补偿系统最大限度地减少了在导电不良的样品图像退化。背向散射检测器和EDS系统提供成分信息和检测细胞和组织内与大分子结合的免疫金颗粒的能力。低温转移系统允许样品快速冷冻，转移到显微镜下，在完全水合状态下以高分辨率观察，水或碳氢化合物的污染最小。水在表面的受控升华揭示表面形态没有主要的结构变化，并确定水在样品中的位置。这些特征对于研究高度含水的样品特别有益，如植物组织或生物膜，它们往往随着水的去除而收缩和崩溃。冷冻转移系统还允许样品在冷冻后和转移和观察之前断裂和/或涂覆。新仪器的主要用户代表了从进化生物学到生物工程的广泛学科。该小组既包括具有成熟项目的高级研究人员，也包括正在发展职业生涯的初级教师。一位资深教员来自康涅狄格学院，这是一个以本科生为主的机构，没有FESEM仪器。这些研究人员正在进行的项目包括木本植物和苔藓植物的水分运输和保护研究、弹枝类绦虫的系统学、绿藻的形态学、沙漠生物结壳的生态学、多孔金属氧化物纳米颗粒的结构、植物细胞壁的分子生物学和生理学、淡水苔藓植物的生态学和生物地理学、海洋生物膜中矿物质的成核、心脏瓣膜的生物力学和微观结构。该系统提供了最先进的电子成像能力，以一个高度活跃和多学科的教师和学生群体，加强研究和研究培训。他们的研究正在帮助识别和分类世界各地发现的新绦虫物种。它描述了生物和岩石圈之间界面上微生物-矿物相互作用的特征，这对寻找生命的起源、其他行星上的生命、自然储层（孔隙度和渗透率）的特征以及碳封存至关重要。对多种植物物种的研究有助于了解陆地植物抵抗干燥和输送水分的能力以及植物细胞壁的组成和功能。在新生代早期的北极湖泊系统中发现的苔藓和硅藻的结构数据为了解未来温室气候下北极生态系统的变化提供了前所未有的机会。多孔氧化物催化剂和八面体分子锰氧化物的结构和组成研究对石油泄漏和污染物的修复具有潜在的应用价值。对心脏瓣膜纤维结构的研究提供了数据，以帮助生成人类心脏瓣膜对微创心脏瓣膜修复和置换的反应的计算模型。购买的设备有助于推动新的研究计划，并促进该研究小组内外的合作研究。

This award provides funds to purchase a Field Emission Scanning Electron Microscope (FESEM) with a cryo transfer stage and an energy dispersive x-ray spectroscopy (EDS) system for the Electron Microscopy Laboratory (EM Lab), a multi-user facility at the main campus of the University of Connecticut. The new instrument replaces a heavily used 15-year old FESEM, thus ensuring continued FESEM availability and providing new capabilities to enhance and expand both research and research training at the University of Connecticut. The FESEM provides images of a variety of materials at resolutions previously unattainable in this facility. A charge compensation system minimizes image degradation in poorly conducting samples. A backscatter detector and EDS system provide compositional information and the ability to detect immunogold particles conjugated to macromolecules within cells and tissues. The cryo transfer system allows samples to be rapidly frozen, transferred to the microscope and viewed at high resolution in the fully hydrated state, with minimal contamination by water or hydrocarbons. Controlled sublimation of water at the surface reveals surface morphology without major structural change and identifies the location of water in the sample. These features are especially beneficial for study of highly hydrated samples such as plant tissues or biofilms, which tend to shrink and collapse with removal of water. The cryo transfer system also allows samples to be fractured and/or coated after freezing and prior to transfer and viewing. The major users of the new instrumentation represent a wide range of disciplines from evolutionary biology to bioengineering. The group includes both senior investigators with well-established programs and junior faculty members developing their careers. One senior faculty member is from Connecticut College, a predominantly undergraduate institution with no FESEM instrumentation. The projects these investigators are carrying out include studies of water transport and conservation in woody plants and bryophytes, systematics of tapeworms in elasmobranchs, morphology of green algae, ecology of desert biotic crusts, structure of porous metal oxide nanoparticles, molecular biology and physiology of plant cell walls, ecology and biogeography of freshwater chrysophytes, nucleation of minerals in marine biofilms, and biomechanics and microstructure of heart valves. This system provides state-of-the-art electron imaging capabilities to a highly active and multidisciplinary group of faculty and students, enhancing both research and research training. Their research is helping to identify and classify new species of tapeworms found around the world. It is characterizing microbe-mineral interactions at the interface between the bio- and lithospheres that are critical in the search of the origin of life, life on other planets, the characterization of natural reservoir (porosity and permeability), and carbon sequestration. Studies of a variety of plant species are contributing to understanding of the ability of land plants to withstand desiccation and transport water and of the composition and function of the plant cell walls. Structural data on chrysophytes and diatomes found in Arctic lake systems of the early Cenozoic are providing an unprecedented opportunity to understand how Arctic ecosystems may change under future greenhouse climates. Structural and compositional studies of porous oxide catelysts and octahedral molecular seive manganese oxides are potentially useful for oil spills and remediation of pollutants. Studies of the fibrous structure of heart valves are providing data to help generate computational models of how human heart valves respond to minimally invasive heart valve repair and replacement. The purchased equipment is helping to drive new research initiatives and promote collaborative research within this group of investigators and beyond.