Completion of High Performance Scanning Ion Microprobe Upgrade

芝加哥大学高分辨率扫描离子微探针（UC SIM）的质量鉴别能力和二次离子探测灵敏度的彻底升级即将完成。这次升级需要将微探针与高性能磁扇形质谱仪连接起来，同时保留主光束离子光学的优越性能，并允许替代使用以前的射频四极杆质量滤波器。虽然这一复杂升级所需的主要硬件和电子部件已经建造完毕，并已投入使用，但新仪器研制的最关键阶段仍待完成。原先在以前的预算限制范围内被认为是次要优先的若干辅助装置的建造，现在被认为是对已经成功的仪器升级的有价值和必要的补充。最重要的是，微探针与高度复杂的Finnigan MAT化学质谱仪联合操作的复杂性需要广泛的优化和性能评估，以及对学生和工作人员的培训。正如我们仪器开发的前几个阶段所展示的那样，同时追求基础生物学研究一直是我们项目的最高优先级之一。在与几家学术机构的知名生物学家的合作下，高分辨率二次离子成像的系统调查和探索性应用已经产生了独特的结果，并在物理和生物科学之间建立了一个非常富有成效的界面。在大大提高的工作水平上，将积极进行几项已经显示出希望的试验性研究：(a)直接绘制人类染色体中同位素标记核苷的分布图和评价脆弱位点的核苷酸含量。(b)同位素标记核苷在黑腹果蝇中期和多丝染色体上的直接定位。(c)破骨细胞启动骨吸收途径的鉴定。测定骨形成和骨吸收过程中钙磷放射性。这将需要用钙同位素作示踪剂的实验，以及磷的检测和测量。U ~ s ~ s %) ~ + *，。g L c X 3 d h Z % i ？- 9317959 Levi-Setti t u的质量鉴别能力和二次离子检测灵敏度的根本性提升) O!!!!F k k；CG时代符号& & Arial 1 Courier 0 MS LineDraw E E h: %: % F = = abstract Deseree King, BIR Deseree King， BIR

9317959 Levi-Setti The radical upgrade of the mass discrimination capability and secondary ion detection sensitivity of the University of Chicago high resolution Scanning Ion Microprobe (UC SIM) is near completion. This upgrade has entailed the interfacing of the microprobe with a high performance magnetic sector mass spectrometer, while retaining the superior performance of the primary beam ion optics and allowing alternate use of the previous RF quadrupole mass filter. Although the principal hardware and electronic components needed for this complex upgrade have been constructed and are now operational, a most critical phase of new instrument development is still to be completed. The construction of several ancillary devices, originally deemed of secondary priority within the previous budgetary constraints, is now regarded as a worthwhile and necessary complement to the already successful instrumental upgrade. Most of all, the complexity of the joint operation of the microprobe with the highly sophisticated Finnigan MAT chemical mass spectrometer requires extensive optimization and performance evaluation, together with training of students and staff. As demonstrated in previous phases of our instrument development, the concurrent pursuit of fundamental biological studies has remained consistently one of the highest priorities of our program. In collaboration with established biologists from several academic institutions, systematic investigations and exploratory applications of high resolution secondary ion imaging have already yielded unique results and have created a very productive interface between the physical and the biological sciences. At a much improved level of performance, several pilot studies which already show promise will be actively pursued: (a) Direct mapping of the distribution of isotope labelled nucleosides in human chromosomes and evaluation of the nucleotide content of fragile sites. (b) Direct mapping of the distribution of isotope labelled nucleosides in Drosophila melanogaster metaphase and polytene chromosomes. (c) Identification of the pathways of bone resorption initiated by osteoclasts. Determination of the calcium to phosphorus radio in bone formation and resorption, This will entail experiments with Ca isotopes as tracers, and the detection and measurement of phosphorus. u ~ s t s % ) ~ + * , . g L c X 3 d h Z % i ? - 9317959 Levi-Setti The radical upgrade of the mass discrimination capability and secondary ion detection sensitivity of t u ) u O ! ! ! ! F K K ; CG Times Symbol & Arial 1 Courier 0 MS LineDraw E E h : % : % F = = abstract Deseree King, BIR Deseree King, BIR