Thermo Electron DELTA V Advantage Isotope Ratio Mass Spectrometer

描述（由申请人提供）：要求购买一台热电子Delta V优势同位素比质谱仪及其附件。该仪器是为了更新美国农业部/美国农业部儿童营养研究中心（CNRC）气体同位素比质谱实验室（GIRMSL）的质谱仪。GIRMSL目前的质谱仪是在1986年至1990年之间购买的。制造商要么不再经营，要么不再支持过时的硬件和操作软件。Delta V仪器是最先进的同位素比质谱仪系统，用于测量稳定的氢和氧同位素。这些同位素是双标记水（DLW）方法的基础，该方法被研究界认为是估计自由生活条件下能量消耗或热量需求的参考方法。随着肥胖的流行，许多研究都在使用DLW方法，因为该方法无创，便携，安全。这使得DLW方法非常适合于涉及婴儿和儿童以及孕妇和哺乳期妇女的研究。随着18o水越来越容易获得，我们预计DLW方法的使用将在不久的将来呈指数级增长。GIRMSL在同位素比质谱仪和DLW方法的操作方面具有丰富的经验。例如，GIRMSL参与了DLW方法在人体能量消耗测量中的首次全室量热验证，并负责开发DLW方法中使用的许多分析技术。1991年，GIRMSL还受国际原子能机构委托，生产几种同位素标准物质，包括浓缩2H和18O标准，以便为世界各地的研究界提供国际认可的标准。更重要的是，GIRMSL自1982年成立以来一直是一个开放实验室，并在该中心和全国范围内培训和支持了许多美国国立卫生研究院资助的研究人员。最近，GIRMSL已被NIH/NIA选定为中央DLW实验室，以支持其多中心CALERIE（减少能量摄入的长期影响综合评估）二期临床试验。目前，GIRMSL还支持NIH在CNRC、波士顿儿童医院、加州大学欧文分校、华盛顿大学圣路易斯分校、范德比尔特大学、塔夫茨大学和彭宁顿生物医学研究中心资助的项目。因此，购买Thermo Electron Delta V仪器的资金将允许GIRMSL继续为NIH资助的研究人员提供培训和分析支持，无论是在CNRC还是在世界各地。

DESCRIPTION (provided by applicant): Support to purchase a Thermo Electron Delta V Advantage isotope ratio mass spectrometer and accessories is requested. The instrument is to update the mass spectrometers in the Gas-Isotope-Ratio Mass Spectrometry Laboratory (GIRMSL) at the USDA/ARS Children's Nutrition Research Center (CNRC). The current mass spectrometers in the GIRMSL were purchased between 1986 and 1990. The manufacturers are either no longer in business or no longer support the antiquated hardware and operating software. The Delta V instrument is the most advanced isotope ratio mass spectrometer system for the measurements of stable hydrogen and oxygen isotopes. These isotopes are the backbone of the doubly labeled water (DLW) method which is considered by the research community to be the reference method for the estimation of energy expenditure or caloric requirement under free-living conditions. With the obesity epidemic, many studies are using the DLW method because the method is non-invasive, portable, and safe. This makes the DLW method ideal for studies involving infants and children as well as pregnant and lactating women. With 18O-water becoming more readily available, we anticipate the use of the DLW method will increase exponentially in the near future. The GIRMSL has extensive experience in the operation of the isotope ratio mass spectrometers and the DLW method. For instance, the GIRMSL participated in the first whole-room calorimetric validation of the DLW method for energy expenditure measurement in man and is responsible for the development of many analytical techniques employed in the DLW method. The GIRMSL also was commissioned by the International Atomic Energy Agency in 1991 to produce several isotope reference materials including enriched 2H and 18O standards in order to provide internationally validated standards for the research community across the world. More importantly, the GIRMSL has been an OPEN laboratory since its inception in 1982 and has trained and supported numerous NIH-funded investigators at the Center and across the country. Recently, the GIRMSL has been selected by the NIH/NIA to be the Central DLW Laboratory to support their multi-center CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) phase 2 clinical trial. Currently, the GIRMSL is also supporting the NIH funded projects at the CNRC, Children's Hospital Boston, University of Califorina at Irvine, Washington University at St. Louis, Vanderbilt University, Tufts University, and Pennington Biomedical Research Center. Therefore, funding to purchase the Thermo Electron Delta V instrument will allow the GIRMSL to continue to provide training and analytical support to NIH funded investigators, both here at the CNRC and around the world. PUBLIC HEALTH RELEVANCE: To combat the epidemic of obesity in this country, it is important to know the amount of energy used or the amount of calorie consumed in the study population. Doubly labeled water is the reference method for estimation of energy expenditure or consumption under free-living conditions. The isotope ratio mass spectrometer requested is the most accurate and precise instrument to measure the stable hydrogen and oxygen isotopes in the doubly labeled water method and will be used for these measurements.