Br-rich tips of calcified crab claws are less hard but more fracture resistant: A comparison of mineralized and heavy-element biological materials

	Br-rich tips of calcified crab claws are less hard but more fracture resistant: A comparison of mineralized and heavy-element biological materials
	Schofield, RMS; Niedbala, JC; Nesson, MH; Tao, Y; Shokes, JE; Scott, RA; Latimer, MJ; Tao Y(陶冶)
刊名	JOURNAL OF STRUCTURAL BIOLOGY
	2009
卷号	166 期号:3 页码:#REF!
关键词	Crab Cheliped Biomineralization Bromine Zinc Br Zn Mechanical properties Hardness Modulus of elasticity Metal Halogen Abrasion Energy of fracture XAS Bromotyrosine Arthropod Cuticle Exoskeleton Invertebrate Scanning X-ray microscopy Scanning X-ray microprobe spectroscopy EXAFS
通讯作者	Schofield, RMS (reprint author), Univ Oregon, Dept Phys, Eugene, OR 97403 USA.
英文摘要	We find that the spoon-like tips of the chelipeds (large claws) of the crab Pachygrapsus crassipes differ from the rest of the claw in that they are not calcified, but instead contain about 1% bromine-thus they represent a new example of a class of structural biological materials that contain heavy elements such as Zn, Mn, Fe, Cu, and Br bound in an organic matrix. X-ray absorption spectroscopy data suggest that the bromine is bound to phenyl rings, possibly in tyrosine. We measure a broad array of mechanical properties of a heavy-element biological material for the first time (abrasion resistance, coefficient of kinetic friction, energy of fracture, hardness, modulus of elasticity and dynamic mechanical properties), and we make a direct comparison with a mineralized tissue. Our results suggest that the greatest advantage of bromine-rich cuticle over calcified cuticle is resistance to fracture (the energy of fracture is about an order of magnitude greater than for calcified cuticle). The greatest advantage relative to unenriched cuticle, represented by ant mandible cuticle, is a factor of about 1.5 greater hardness and modulus of elasticity. The spoon-like tips gain additional fracture resistance from the orientation of the constituent laminae and from the viscoelasticity of the material. We suggest that fracture resistance is of greater importance in smaller organisms, and we speculate that one function of heavy elements in structural biological materials is to reduce molecular resonant frequencies and thereby increase absorption of energy from impacts. (C) 2009 Elsevier Inc. All rights reserved.
学科主题	Biochemistry & Molecular Biology; Biophysics; Cell Biology
类目[WOS]	Biochemistry & Molecular Biology ; Biophysics ; Cell Biology
收录类别	SCI
WOS记录号	WOS:000266066500004
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/227323]
专题	高能物理研究所_多学科研究中心
推荐引用方式 GB/T 7714	Schofield, RMS,Niedbala, JC,Nesson, MH,et al. Br-rich tips of calcified crab claws are less hard but more fracture resistant: A comparison of mineralized and heavy-element biological materials[J]. JOURNAL OF STRUCTURAL BIOLOGY,2009,166(3):#REF!.
APA	Schofield, RMS.,Niedbala, JC.,Nesson, MH.,Tao, Y.,Shokes, JE.,...&陶冶.(2009).Br-rich tips of calcified crab claws are less hard but more fracture resistant: A comparison of mineralized and heavy-element biological materials.JOURNAL OF STRUCTURAL BIOLOGY,166(3),#REF!.
MLA	Schofield, RMS,et al."Br-rich tips of calcified crab claws are less hard but more fracture resistant: A comparison of mineralized and heavy-element biological materials".JOURNAL OF STRUCTURAL BIOLOGY 166.3(2009):#REF!.