In the paper, two theoretical poroelastic osteon models are presented to compare their poroelastic behaviors, one is the hollow osteon model （Haversian fluid is neglected） and the other is the osteon model with Have...In the paper, two theoretical poroelastic osteon models are presented to compare their poroelastic behaviors, one is the hollow osteon model （Haversian fluid is neglected） and the other is the osteon model with Haversian fluid con- sidered. They both have the same two types of imperme- able exterior boundary conditions, one is elastic restraint and the other is displacement constrained, which can be used for analyzing other experiments performed on similarly shaped poroelastic specimens. The obtained analytical pressure and velocity solutions demonstrate the effects of the loading fac- tors and the material parameters, which may have a signifi- cant stimulus to the mechanotransduction of bone remodel- ing signals. Model comparisons indicate： （1） The Haversian fluid can enhance the whole osteonal fluid pressure and ve- locity fields. （2） In the hollow model, the key loading fac- tor governing the poroelastic behavior of the osteon is strain rate, while in the model with Haversian fluid considered, the strain rate governs only the velocity. （3） The pressure ampli- tude is proportional to the loading frequency in the hollow model, while in the model with Haversian fluid considered, the loading frequency has little effect on the pressure ampli- tude.展开更多
Background:Human bone analysis is a useful tool in assessing and identifying skeletal remains.To make this easier,newer and modified approaches have often being documented.Aims and Objectives:The aim of this study is ...Background:Human bone analysis is a useful tool in assessing and identifying skeletal remains.To make this easier,newer and modified approaches have often being documented.Aims and Objectives:The aim of this study is to analyze the histomorphometric features of various bone segments and its relevance in forensic case diagnosis.Materials and Methods:The human bones used were that of cadaveric bone samples harvested from three adult male Nigerians.The proximal,midshaft and distal segments of the femur,tibia,and humerus were utilized for the study.The bone sections were subjected to processing using Frost’s rapid manual preparation of ground sections techniques.Histomorphometric evaluation studied the number of primary osteons,secondary osteons,and osteon fragments,as well as the Haversian canal diameter(HCD).Results:The primary osteons,secondary osteons,osteon fragments,and HCD in each of the segments of the long bones show that the F values are less than the F critical for an alpha level of 0.05.This shows that there is no statistically significant(P>0.05)variation in the histomorphometric pattern for the various segments of the bones studied.Again differences in the haversian canal diameter of the various segments of the long bones shows statistically significant variation(P<0.05)among the long bones investigated.Conclusion:These findings have laid to rest the challenges with using the only available bone fragment for forensic case investigation as no notable variations exist across various segments.展开更多
Objective： To observe the distribution of the nerve fibers in the bone tissue and the entry points of these fibers into the bone. Methods： The adult tibia was used for the ground sections which were afterwards made...Objective： To observe the distribution of the nerve fibers in the bone tissue and the entry points of these fibers into the bone. Methods： The adult tibia was used for the ground sections which were afterwards made into the slice sections by decalcification in ethylenediamine tetraacetic acid （EDTA）. The ground sections were stained in silver and the slice sections were stained in silver and haematoxylin and eosin （HE） respectively. Then, the samples of the transmission electron microscope and the atomic force microscope were made and observed. Results ： In the human long bone tissue, many nerve fibers were distributed in the membrane, cortical bone, cancellous bone and marrow. The nerve fibers entered the bone from the nutrient foramen, and passed through the nutrient canal, Haversian＇ s canal and Volkmann＇ s canal, and finally into the bone marrow. In the nutrient canal, the nerve fibers, mainly the medullary nerve fibers, followed the blood vessel into the bone. In the cortical bone, the nerve fibers also followed the blood vessels and were mainly distributed along Haversian＇ s canal and Volkmann＇ s canal. In the bone trabecular and bone marrow, there were many nerve fiber endings arranged around the blood vessels, mainly around the tunica media of medium-size arteries in the marrow and around capillary blood vessels, and a few scattered in the bone marrow. There were sporadic nerve endings in epiphyseal plate and no nerve fibers permeated epiphysis to diaphysis. No distribution of nerve fibers could be found in cartilaginous part. Conclusions： There are many nerve fibers in bone and the nerve passageway is nutrient foramen, Volkman＇ s canal, Haversian＇ s canal and bone marrow.展开更多
基金supported by the National Natural Science Foundation of China(11032008 and 11302143)
文摘In the paper, two theoretical poroelastic osteon models are presented to compare their poroelastic behaviors, one is the hollow osteon model （Haversian fluid is neglected） and the other is the osteon model with Haversian fluid con- sidered. They both have the same two types of imperme- able exterior boundary conditions, one is elastic restraint and the other is displacement constrained, which can be used for analyzing other experiments performed on similarly shaped poroelastic specimens. The obtained analytical pressure and velocity solutions demonstrate the effects of the loading fac- tors and the material parameters, which may have a signifi- cant stimulus to the mechanotransduction of bone remodel- ing signals. Model comparisons indicate： （1） The Haversian fluid can enhance the whole osteonal fluid pressure and ve- locity fields. （2） In the hollow model, the key loading fac- tor governing the poroelastic behavior of the osteon is strain rate, while in the model with Haversian fluid considered, the strain rate governs only the velocity. （3） The pressure ampli- tude is proportional to the loading frequency in the hollow model, while in the model with Haversian fluid considered, the loading frequency has little effect on the pressure ampli- tude.
文摘Background:Human bone analysis is a useful tool in assessing and identifying skeletal remains.To make this easier,newer and modified approaches have often being documented.Aims and Objectives:The aim of this study is to analyze the histomorphometric features of various bone segments and its relevance in forensic case diagnosis.Materials and Methods:The human bones used were that of cadaveric bone samples harvested from three adult male Nigerians.The proximal,midshaft and distal segments of the femur,tibia,and humerus were utilized for the study.The bone sections were subjected to processing using Frost’s rapid manual preparation of ground sections techniques.Histomorphometric evaluation studied the number of primary osteons,secondary osteons,and osteon fragments,as well as the Haversian canal diameter(HCD).Results:The primary osteons,secondary osteons,osteon fragments,and HCD in each of the segments of the long bones show that the F values are less than the F critical for an alpha level of 0.05.This shows that there is no statistically significant(P>0.05)variation in the histomorphometric pattern for the various segments of the bones studied.Again differences in the haversian canal diameter of the various segments of the long bones shows statistically significant variation(P<0.05)among the long bones investigated.Conclusion:These findings have laid to rest the challenges with using the only available bone fragment for forensic case investigation as no notable variations exist across various segments.
文摘Objective： To observe the distribution of the nerve fibers in the bone tissue and the entry points of these fibers into the bone. Methods： The adult tibia was used for the ground sections which were afterwards made into the slice sections by decalcification in ethylenediamine tetraacetic acid （EDTA）. The ground sections were stained in silver and the slice sections were stained in silver and haematoxylin and eosin （HE） respectively. Then, the samples of the transmission electron microscope and the atomic force microscope were made and observed. Results ： In the human long bone tissue, many nerve fibers were distributed in the membrane, cortical bone, cancellous bone and marrow. The nerve fibers entered the bone from the nutrient foramen, and passed through the nutrient canal, Haversian＇ s canal and Volkmann＇ s canal, and finally into the bone marrow. In the nutrient canal, the nerve fibers, mainly the medullary nerve fibers, followed the blood vessel into the bone. In the cortical bone, the nerve fibers also followed the blood vessels and were mainly distributed along Haversian＇ s canal and Volkmann＇ s canal. In the bone trabecular and bone marrow, there were many nerve fiber endings arranged around the blood vessels, mainly around the tunica media of medium-size arteries in the marrow and around capillary blood vessels, and a few scattered in the bone marrow. There were sporadic nerve endings in epiphyseal plate and no nerve fibers permeated epiphysis to diaphysis. No distribution of nerve fibers could be found in cartilaginous part. Conclusions： There are many nerve fibers in bone and the nerve passageway is nutrient foramen, Volkman＇ s canal, Haversian＇ s canal and bone marrow.
