VIBRATIONALLY COOLED MATRIX-ASSIST LASER DESORPTION/IONIZATION FTMS

振动冷却基质辅助激光解吸/电离 FTMS

• 批准号: 7955884
• 负责人: PETER B. O'CONNOR
• 金额: $ 0.95万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7955884
• 关键词: Aluminum; Area; Articular Range of Motion; Automation; Back; Biology; Caliber; Cardiovascular system; Collaborations; Computer Retrieval of Information on Scientific Projects Database; Copper; Diffusion; Electronics; Fourier Transform; Funding; Grant; Hardness; Heating; Image; Institutes; Institution; Language; Lasers; Libraries; Link; Lubrication; Magnetism; Marshal; Mass Spectrum Analysis; Medicine; Motor; Noise; Oils; Optics; Performance; Positioning Attribute; Programming Languages; Proteomics; Pump; Research; Research Personnel; Resources; Robot; Route; Sampling; Shipping; Ships; Signal Transduction; Slide; Source; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Speed; Spottings; Staging; Stainless Steel; Surface; System; Testing; Time; Torque; Translations; Travel; United States National Institutes of Health; Vacuum; Vent; Visit; Visual; Work; base; cryogenics; design; design and construction; evaluation/testing; improved; instrument; mass spectrometer; pressure; prevent; research study; two-dimensional; vapor; virtual

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The improvement and optimization of the Vibrationally Cooled MALDI-FTMS continues. This year we carried out further testing and evaluation of the XY stage that was designed and constructed in collaboration with the Fraunhofer Institute. This stage is a critical component for full automation of the MALDI-FTMS. The design parameters for this stage were defined to handle the typical proteomic type sample. Many proteomic experiments use robots that are designed to work with microtiter plates which are ~76 x 89 mm in size. Therefore, the stage was required to have full travel of at least 100 x 100 mm. For the MALDI Fourier transform mass spectrometer used, the travel time from spot to spot is not the limiting factor in the experiment speed, so a travel of 2 mm/sec was defined as it would allow the stage to position to the next spot 1 mm away in 0.5 seconds. The positioning accuracy was defined to be 1 um, which is much more accurate than is needed for the standard MALDI experiment in which the laser beam spot is often 50 um diameter, but will allow the stage to be used in a MALDI imaging mode. Aside from this, the stage had to be truly vacuum compatible, had to be mounted vertically, and to generate no detectable RF interference noise, and had to take up minimal space so that the vacuum chamber could be made as small as possible for improved pumping performance. The two-dimensional stage is a single block design with the two axis motors, linear encoders, and position switches all integrated into the central block. The system uses ballscrews and crossed roller bearings which will require minimal lubrication in vacuum; what little lubrication is needed is provided by low vapor pressure diffusion pump oil. In order to build the motors into this block, they are mounted on copper brackets (to dump their heat into the block which acts as a heat sink) and pulleys are used to transfer their torque to the ballscrew. The belts for these pulleys are actually small electrowelded stainless steel bands, and in order to keep them centered on the pulleys, the pulley wheels are ground to be slightly concave. Tensioning set screws are mounted into the block to allow the pulleys to be tightened properly during testing. In order to prevent over determination of the position of the ballscrew, it is mounted in two places only: the pulley bearing assembly and the plate. The stage itself is designed in three pieces, an upper and lower plate, and the central block. The motors, limit switches, and linear encoder electronics are all mounted (and heat sinked) to the central block. The linear encoder slides are mounted to the upper and lower plates. The three pieces are black anodized to improve surface hardness, but even more importantly, to improve radiative cooling of the blocks. All wire routes are also contained within the block. The motors and electronics dump their heat loads into the central block, which is only able to dissipate that heat through conductive cooling at the bearings and radiative cooling. The conductive cooling is very inefficient since the bearings are stainless steel (very low heat transfer capacity) and the contact area is very low. A copper band or braid was considered for improving the conductive heat transfer rate, but a quick calculation of the heat transfer of such a band compared to the radiative cooling rate showed that the heat transfer through the copper band was negligible. There are several positioning screws for the crossed roller bearings, wire traces, and bolt holes for mounting the motors, bearings, and electronics. All of these holes are vented to minimize virtual leaks. The system uses four position encoders, two linear encoders for determining position, and two rotary encoders mounted on the back of the motors for determining velocity. The system uses optical limit switches. The switch is a photodiode/phototransistor pair mounted on the central stage body which is interrupted by an aluminum flag mounted on the upper and lower stage plates. Two such switches are mounted for each axis. When the stage moves to the end of its range of motion, this flag blocks the photodiode's signal to the phototransistor, and the electronics signal the stage to stop. Such a system, while similar to a rocker switch or magnetic switch involves fewer parts and greater positioning accuracy. The sample translation stage requires a large number of vacuum electrical feedthroughs (46) to control 2 motors, 4 encoders, 4 limit switches, and a thermocouple. Furthermore, because this is being mounted on an FTMS which has high sensitivity to RF interference noise, it was critical that the feedthrough and cables be well shielded. The vacuum chamber for this sample translation stage was designed to be as small as possible (for efficient pumpdown) but large enough to allow the full range of motion for the stage. The sample translation stage control was developed as a set of commands that can be called from a dynamically linked library (dll) in any Microsoft window's based programming language. The language used here was C++ as implemented in Microsoft Visual C++, version 6. A copy of the stage was constructed for use with the cryogenic FTMS being assembled within the BUSM Cardiovascular Proteomics Center and the Resource instrument has been used for its testing and evaluation prior to installation in the cryoFTMS. Additional copies have been shipped to R. Heeren, FOM Amsterdam and A. G. Marshall, NHMFL, Gainesville, FL. K. Aizikov visited FOM for the installation, testing and initial experiments.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 振动冷却的MALDI-FTM的改进和优化仍在继续。 今年，我们对与Fraunhofer Institute合作设计和构建的XY阶段进行了进一步的测试和评估。 此阶段是MALDI-FEFM完全自动化的关键组成部分。 定义了此阶段的设计参数以处理典型的蛋白质组织样品。 许多蛋白质组学实验使用的机器人旨在与尺寸约76 x 89毫米的微量滴定板一起使用。 因此，要求阶段至少完全行驶100 x 100毫米。 对于使用的MALDI傅立叶变换质谱仪，从点到点的旅行时间不是实验速度的限制因素，因此定义了2 mm/sec的行程，因为它可以在0.5秒内将阶段定位到下一个位置1 mm的位置。 定位精度定义为1 UM，比标准MALDI实验所需的精确度要精确得多，在该标准MALDI实验中，激光光束斑点通常直径为50 UM，但将允许在MALDI成像模式下使用该阶段。 除此之外，阶段必须真正兼容，必须垂直安装，并且没有产生可检测的RF干扰噪声，并且必须占用最小的空间，以便可以使真空室尽可能小，以提高抽水性能。 二维阶段是带有两个轴电机，线性编码器的单个块设计，并且位置开关都集成到中央块中。 该系统使用滚球和交叉辊轴承，需要在真空中润滑最少。低蒸气压扩散泵油提供的几乎没有润滑。 为了将电动机置于此块中，它们安装在铜支架上（将热量倒入充当散热器的块中），并使用皮带轮将其扭矩传递到弹丸上。这些皮带轮的皮带实际上是小的电气不锈钢带，为了使它们居中在皮带轮上，滑轮轮的地面略微凹陷。 张紧套件被安装到块中，以使皮带轮在测试过程中正确拧紧。 为了防止过度确定击球的位置，它仅在两个地方安装：皮带轮轴承组件和板。 舞台本身的设计分为三块，上板和下板以及中央块。 电动机，限制开关和线性编码器电子设备都安装在中央块上。 线性编码器载玻片安装在上部和下板上。 这三块是黑色阳极氧化的，以改善表面硬度，但更重要的是，可以改善块的辐射冷却。 所有电线路线也包含在块中。 电动机和电子设备将其热量载入中央块，这只能通过在轴承和辐射冷却下通过导电冷却来散发热量。 导电冷却非常低效，因为轴承是不锈钢（非常低的传热能力），并且接触面积非常低。 考虑了用于提高导电传热速率的铜带或辫子，但是与辐射冷却速率相比，这种带的传热速度的快速计算表明，通过铜带的热传递可以忽略不计。 有几个定位螺钉，用于越过的滚子轴承，电线轨迹和螺栓孔，用于安装电动机，轴承和电子设备。 所有这些孔都被排气以最大程度地减少虚拟泄漏。 系统使用四个位置编码器，两个线性编码器来​​确定位置，以及安装在电动机背面的两个旋转编码器来确定速度。 系统使用光学限制开关。 开关是安装在中央舞台主体上的光电二极管/光晶体管对，被安装在上层和下阶层板上的铝制标志中断。 每个轴安装了两个这样的开关。 当阶段移至其运动范围的末端时，该标志将光电二极管的信号阻塞到光晶体管，并且电子设备向停止的阶段发出信号。 这样的系统虽然类似于摇杆开关或磁开关，涉及较少的零件和更高的定位精度。 样品翻译阶段需要大量的真空电馈线（46）来控制2个电动机，4个编码器，4个限制开关和一个热电偶。 此外，由于将其安装在对RF干扰噪声高灵敏度的FTM上，因此至关重要的是将进料和电缆充分屏蔽。 该样品翻译阶段的真空室被设计为尽可能小（用于有效的抽水台），但足够大，可以允许阶段的全部运动范围。 示例翻译阶段控制是作为一组命令开发的，可以从任何Microsoft Window的基于的编程语言中的动态链接库（DLL）调用。 此处使用的语言是C ++，如Microsoft Visual C ++（版本6）所实现的。该阶段的副本被构建，用于在BUSM心血管蛋白质组学中心组装的低温FTM，并且资源仪器已用于在网络上安装之前的测试和评估。 佛罗里达州盖恩斯维尔的NHMFL的R. Heeren，Fom Amsterdam和A. G. Marshall已将其他副本运送到R. Heeren和A. G. Marshall。 K. Aizikov访问了FOM进行安装，测试和初始实验。