Dielectric properties measurements of brown and white adipose tissue in rats from 0.5 to 10 GHz.
Dielectric properties measurements of brown and white adipose tissue in rats from 0.5 to 10 GHz.
复制标题
在 0.5 至 10 GHz 范围内测量大鼠棕色和白色脂肪组织的介电特性。
DOI：
10.1088/2057-1976/2/2/025005
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发表时间：
2016
影响因子：
1.4
通讯作者：
Topsakal,E
中科院分区：
文献类型：
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作者：
Rodrigues,DB;Stauffer,PR;Colebeck,E;Hood,AZ;Salahi,S;Maccarini,PF;Topsakal,E
棕色脂肪组织（BAT）在全身代谢中起着重要作用，适当的刺激可能介导体重增加和胰岛素敏感性。虽然成像技术可用于检测地下BAT，但目前没有可行的方法用于连续采集BAT能量消耗。微波（MW）辐射测量是一种新兴的技术，允许量化的组织温度变化在几厘米的深度。这种温差可能与代谢率的变化有关，从而提供了监测最佳可得技术代谢的定量方法。为了优化微波辐射测量，需要具有精确介电特性的数值和实验模型来开发和校准辐射传感器。因此，我们提出了第一次，表征的相对介电常数和电导率的棕色（BAT）和白色（WAT）脂肪组织在大鼠在MW范围0.5-10 GHz。对6只体重约为200 g的雌性大鼠进行原位和死后测量。使用Cole-Cole模型将实验数据拟合成参数模型，该模型描述了介电特性随频率的变化。测量证实BAT的介电性能（ε r= 14.0-19.4，σ= 0.3-3.3 S m− 1）显著高于WAT的介电性能（ε r= 9.1-11.9，σ= 0.1-1.9 S m− 1），这与BAT的较高水含量一致。
Brown adipose tissue (BAT) plays an important role in whole body metabolism and with appropriate stimulus could potentially mediate weight gain and insulin sensitivity. Although imaging techniques are available to detect subsurface BAT, there are currently no viable methods for continuous acquisition of BAT energy expenditure. Microwave (MW) radiometry is an emerging technology that allows the quantification of tissue temperature variations at depths of several centimeters. Such temperature differentials may be correlated with variations in metabolic rate, thus providing a quantitative approach to monitor BAT metabolism. In order to optimize MW radiometry, numerical and experimental phantoms with accurate dielectric properties are required to develop and calibrate radiometric sensors. Thus, we present for the first time, the characterization of relative permittivity and electrical conductivity of brown (BAT) and white (WAT) adipose tissues in rats across the MW range 0.5–10 GHz. Measurements were carried out in situ and post mortem in six female rats of approximately 200 g. A Cole–Cole model was used to fit the experimental data into a parametric model that describes the variation of dielectric properties as a function of frequency. Measurements confirm that the dielectric properties of BAT (ε r= 14.0–19.4, σ= 0.3–3.3 S m− 1) are significantly higher than those of WAT (ε r= 9.1–11.9, σ= 0.1–1.9 S m− 1), in accordance with the higher water content of BAT.