Low-frequency low-field magnetic susceptibility of ferritin and hemosiderin
Low-frequency low-field magnetic susceptibility of ferritin and hemosiderin
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DOI：
10.1016/s0925-4439(99)00104-0
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发表时间：
2000-02-21
影响因子：
6.2
通讯作者：
Rao, KV
中科院分区：
文献类型：
--
作者：
Allen, PD;St Pierre, TG;Rao, KV
对哺乳动物组织氧化铁沉积物的四个样品进行了低频低场磁化率测量。样品包括：(1)马脾铁蛋白； (') 儒艮肝含铁血黄素； (3)地中海贫血人脾铁蛋白； (4)粗制地中海贫血人脾含铁血黄素。选择这些样品是因为对样品的穆斯堡尔光谱测量表明它们例证了哺乳动物组织氧化铁沉积物中发现的磁性和矿物结构的变化。交流磁感度计获得了四个样品的磁化动力学信息，表明样品 1、2 和 3 具有超顺磁性，尼尔-阿伦尼乌斯方程中的指前频率因子值约为 10(11) s(-1)，特征磁各向异性能垒的值在 250-400 K 范围内。样品 4 在高于 1.3 K 的所有温度下均具有顺磁性。交流磁敏感度测量数据还表明，与样品 1 和 3 相比，儒艮肝脏样品中的磁各向异性能量分布更大，这与之前关于这些样品的穆斯堡尔光谱数据一致。在低于 200 K 的温度下，样品 1-3 表现出居里-韦斯定律行为，表明弱的粒子-粒子相互作用倾向于有利于粒子磁矩的反平行排列。这些相互作用对于儒艮肝含铁血黄素最为强烈。可能反映了该样品中矿物颗粒之间的较小分离。这是第一个针对含铁血黄素铁沉积物的磁感受器研究，并表明交流磁感受器技术是研究此类组织氧化铁沉积物的一种快速且信息丰富的方法。 (C) 2000 Elsevier Science B.V. 保留所有权利。
Low-frequency low-field magnetic susceptibility measurements were made on four samples of mammalian tissue iron oxide deposits. The samples comprised: (1) horse spleen ferritin; (') dugong liver hemosiderin; (3) thalassemic human spleen ferritin; and (4) crude thalassemic human spleen hemosiderin. These samples were chosen because Mossbauer spectroscopic measurements on the samples indicated that they exemplified the variation in magnetic and mineral structure found in mammalian tissue iron oxide deposits. The AC-magnetic susceptometry yielded information on the magnetization kinetics of the four samples indicating samples 1, 2, and 3 to be superparamagnetic with values of around 10(11) s(-1) for the preexponential frequency factor in the Neel-Arrhenius equation and values for characteristic magnetic anisotropy energy barriers in the range 250-400 K. Sample 4 was indicated to he paramagnetic at all temperatures above 1.3 K. The AC-magnetic susceptometry data also indicated a larger magnetic anisotropy energy distribution in the dugong liver sample compared with samples 1 and 3 in agreement with previous Mossbauer spectroscopic data on these samples. At temperatures below 200 K, samples 1-3 exhibited Curie-Weiss law behavior, indicating weak particle-particle interactions tending to favor antiparallel alignment of the particle magnetic moments. These interactions were strongest for the dugong liver hemosiderin. possibly reflecting the smaller separation between mineral particles in this sample. This is the first magnetic susceptometry study of hemosiderin iron deposits and demonstrates that the AC-magnetic susceptometry technique is a fast and informative method of studying such tissue iron oxide deposits. (C) 2000 Elsevier Science B.V. All rights reserved.