High Performance Secondary Ion Mass Spectrometer Upgrade of Advanced Scanning Ion Microprobe

我们提出了一个生物仪器开发计划， 大规模歧视能力的根本升级， 芝加哥大学二次离子探测灵敏度 高分辨率扫描离子微探针（UC SIM）。 这要作 通过替换现有的RF四极杆质量过滤器来实现 高性能扇形磁质谱仪 的 设计和构造适当的传输光学器件，以及 对本二次离子提取系统的改进， 加上高压和硬件建设， 要实现这一目标。 追求根本 生物学研究的性能水平大大提高， 这一文书，已经作出了重大贡献 许多领域的进展得益于成像显微分析， 说明拟议升级的合理性。 来自多个学术机构的知名生物学家将 与我们合作，在升级后的 微探针，在所有情况下的延续和扩增 已成功进行了UC SIM的试点实验。 这些应用程序的目的是： (a)同位素标记的放射性核素分布的指向矢作图 人类染色体中的核苷酸和评估 脆性位点的核苷酸含量。 (b)骨中矿物相的鉴定 骨吸收的形成和机制 由破骨细胞启动。 这将需要实验 以Ca同位素为示踪剂，进行检测和 磷的测量。 (c)微量元素在牙体及牙周组织中的定位及动力学研究 骨组织，相对于显微结构。 受影响器官（骨、脑）的显微结构研究 铝。 (d)钙离子在神经元缺血中作用的研究 视网膜神经元作为模型系统。 这些研究将 利用Ca同位素和同位素标记 核苷酸作为示踪剂。

We propose a biological instrumentation development program aimed at a radical upgrade of the mass discrimination capability and secondary ion detection sensitivity of the University of Chicago high resolution Scanning Ion Microprobe (UC SIM). This is to be accomplished by replacing the existing RF quadrupole mass filter with a high performance magnetic sector mass spectrometer. The design and construction of appropriate transfer optics, and modification to the present secondary ion extraction system, together with high voltage and hardware construction, will be required to implement this goal. The pursuit of fundamental biological studies at a much improved level of performance with this instrument, that has already contributed substantial advances in many areas that benefit from imaging microanalysis, justifies the proposed upgrade. Established biologists from several academic institutions will collaborate with us in exciting applications of the upgraded microprobe, in all cases continuation and amplification of successful pilot experiments already carried out with the UC SIM. These applications will aim at: (a) Director mapping of the distribution of isotope-labelled nucleotides in human chromosomes and evaluation of the nucleotide content of fragile sites. (b) Identification of the mineral phases involved in bone formation and of the mechanism of bone resorption initiated by osteoclasts. This will entail experiments with Ca isotopes as tracers, and the detection and measurement of phosphorus. (c) Localization and kinetics of trace elements in tooth and bone tissues, relative to microstructure. Microstructural study of organs (bone, brain) affected by aluminum. (d) Study of the role of calcium in neuronal ischemia using retinal neurons as model system. These studies will make use of Ca isotopes and isotope-labelled nucleotides as tracers.