BACKGROUND Intracranial atherosclerosis,a leading cause of stroke,involves arterial plaque formation.This study explores the link between plaque remodelling patterns and diabetes using high-resolution vessel wall imag...BACKGROUND Intracranial atherosclerosis,a leading cause of stroke,involves arterial plaque formation.This study explores the link between plaque remodelling patterns and diabetes using high-resolution vessel wall imaging(HR-VWI).AIM To investigate the factors of intracranial atherosclerotic remodelling patterns and the relationship between intracranial atherosclerotic remodelling and diabetes mellitus using HR-VWI.METHODS Ninety-four patients diagnosed with middle cerebral artery or basilar artery INTRODUCTION Intracranial atherosclerotic disease is one of the main causes of ischaemic stroke in the world,accounting for approx-imately 10%of transient ischaemic attacks and 30%-50%of ischaemic strokes[1].It is the most common factor among Asian people[2].The adaptive changes in the structure and function of blood vessels that can adapt to changes in the internal and external environment are called vascular remodelling,which is a common and important pathological mechanism in atherosclerotic diseases,and the remodelling mode of atherosclerotic plaques is closely related to the occurrence of stroke.Positive remodelling(PR)is an outwards compensatory remodelling where the arterial wall grows outwards in an attempt to maintain a constant lumen diameter.For a long time,it was believed that the degree of stenosis can accurately reflect the risk of ischaemic stroke[3-5].Previous studies have revealed that lesions without significant luminal stenosis can also lead to acute events[6,7],as summarized in a recent meta-analysis study in which approximately 50%of acute/subacute ischaemic events were due to this type of lesion[6].Research[8,9]has pointed out that the PR of plaques is more dangerous and more likely to cause acute ischaemic stroke.Previous studies[10-13]have found that there are specific vascular remodelling phenomena in the coronary and carotid arteries of diabetic patients.However,due to the deep location and small lumen of intracranial arteries and limitations of imaging techniques,the relationship between intracranial arterial remodelling and diabetes is still unclear.In recent years,with the development of magnetic resonance technology and the emergence of high-resolution(HR)vascular wall imaging,a clear and multidimensional display of the intracranial vascular wall has been achieved.Therefore,in this study,HR wall imaging(HR-VWI)was used to display the remodelling characteristics of bilateral middle cerebral arteries and basilar arteries and to explore the factors of intracranial vascular remodelling and its relationship with diabetes.展开更多
Objective To analyze the forces of rotational wall vessel （RWV） bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor. Methods The motion...Objective To analyze the forces of rotational wall vessel （RWV） bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor. Methods The motion of the microcarrier in the rotating wall vessel （RWV） bioreactor with both the inner and outer cylinders rotating was modeled by numerical simulation. Results The continuous trajectory of microcarrier particles, including the possible collision with the wall was obtained. An expression between the minimum rotational speed difference of the inner and outer cylinders and the microcarrier particle or aggregate radius could avoid collisions with either wall. The range of microcarrier radius or tissue size, which could be safely cultured in the RWV bioreactor, in terms of shear stress level, was determined. Conclusion The model works well in describing the trajectory of a heavier microcarrier particle in rotating wall vessel.展开更多
This study presents an analytical solution of thermal and mechanical displacements, strains, and stresses for a thick-walled rotating spherical pressure vessel made of functionally graded materials (FGMs). The pressur...This study presents an analytical solution of thermal and mechanical displacements, strains, and stresses for a thick-walled rotating spherical pressure vessel made of functionally graded materials (FGMs). The pressure vessel is subject to axisymmetric mechanical and thermal loadings within a uniform magnetic field. The material properties of the FGM are considered as the power-law distribution along the thickness. Navier’s equation, which is a second-order ordinary differential equation, is derived from the mechanical equilibrium equation with the consideration of the thermal stresses and the Lorentz force resulting from the magnetic field. The distributions of the displacement, strains, and stresses are determined by the exact solution to Navier’s equation. Numerical results clarify the influence of the thermal loading, magnetic field, non-homogeneity constant, internal pressure, and angular velocity on the magneto-thermo-elastic response of the functionally graded spherical vessel. It is observed that these parameters have remarkable effects on the distributions of radial displacement, radial and circumferential strains, and radial and circumferential stresses.展开更多
In order to provide an experimental foundation and pathological base for earlyreconstruction of maxillofacial tissues defects after firearms wound using microsurgicalmethods,an experiment,was made to study the microva...In order to provide an experimental foundation and pathological base for earlyreconstruction of maxillofacial tissues defects after firearms wound using microsurgicalmethods,an experiment,was made to study the microvascular pathological changesthrough light and electron microscopy observation.In the experiment we found somepathological changes of small vessels in wounded region,such as mierothrombi forma-tion,endothelial loss,internal elastic membrane break and some degenerations,necrosis within endothelial and smooth muscle cells of vessel.The nearer the woundededge was,the more evident injury was.The microvascular injurous range was 3 cm dis-tant from wounded edge,which recovered in 7 days later after wounding.The experi-ment indicated that if we used the vascularized free tissue transfer to repair defects ofmaxillofacial firearms wounds,the pedicles of flap should be anastomosed to distant re-cipient vesseles which could be chosen beyond 3 cm from wounded edge.Thereconstructive operation should be done 7 days later after wound.展开更多
A problem of couple motion between vessel wall and blood in the entrance regionof a tapered vessel is considered in this paper A mathematical model of co-coupleaction is formed for both motion of vessel wall and blood...A problem of couple motion between vessel wall and blood in the entrance regionof a tapered vessel is considered in this paper A mathematical model of co-coupleaction is formed for both motion of vessel wall and blood flow in the entrance regance regionof elastic vessel with tapered angle. Under the situation that the relative boundary conditions are satisfied a.set of velocity distribution formula. pressure distributionformula for the blood flow in a tapered elastic vessel are derived. Some importantconclusions are obtained.展开更多
This paper discusses the stresses developed in a thin-walled pressure vessels. Pressure vessels (cylindrical or spherical) are designed to hold gases or liquids at a pressure substantially higher than the ambient pres...This paper discusses the stresses developed in a thin-walled pressure vessels. Pressure vessels (cylindrical or spherical) are designed to hold gases or liquids at a pressure substantially higher than the ambient pressure. Equations of static equilibrium along with the free body diagrams will be used to determine the normal stresses in the circumferential or hoop direction and in the longitudinal or axial direction. A case study of internal pressure developed in a soda can was determined by measuring the elastic strains of the surface of the soda can through strain gages attached to the can and connected to Strain indicator Vishay model 3800.展开更多
脑小血管病(cerebral small vessel disease,CSVD)是一组临床、影像、病理综合征,主要累及颅内小血管,起病隐匿。CSVD与卒中、认知下降、情感障碍、步态异常及尿便失禁密切相关,给家庭和社会带来沉重的疾病负担和经济负担。但CSVD的致...脑小血管病(cerebral small vessel disease,CSVD)是一组临床、影像、病理综合征,主要累及颅内小血管,起病隐匿。CSVD与卒中、认知下降、情感障碍、步态异常及尿便失禁密切相关,给家庭和社会带来沉重的疾病负担和经济负担。但CSVD的致病机制仍不明确,临床诊断标准不统一,临床诊疗和试验研究面临重大挑战。本文旨在汇总当前CSVD的可能病因、发病机制和临床诊疗研究的进展及局限性,展望CSVD未来可能的临床研究方向。展开更多
基金Supported by National Natural Science Foundation of China,No.82071871Guangdong Basic and Applied Basic Research Foundation,No.2021A1515220131+1 种基金Guangdong Medical Science and Technology Research Fund Project,No.2022111520491834Clinical Research Project of Shenzhen Second People's Hospital,No.20223357022。
文摘BACKGROUND Intracranial atherosclerosis,a leading cause of stroke,involves arterial plaque formation.This study explores the link between plaque remodelling patterns and diabetes using high-resolution vessel wall imaging(HR-VWI).AIM To investigate the factors of intracranial atherosclerotic remodelling patterns and the relationship between intracranial atherosclerotic remodelling and diabetes mellitus using HR-VWI.METHODS Ninety-four patients diagnosed with middle cerebral artery or basilar artery INTRODUCTION Intracranial atherosclerotic disease is one of the main causes of ischaemic stroke in the world,accounting for approx-imately 10%of transient ischaemic attacks and 30%-50%of ischaemic strokes[1].It is the most common factor among Asian people[2].The adaptive changes in the structure and function of blood vessels that can adapt to changes in the internal and external environment are called vascular remodelling,which is a common and important pathological mechanism in atherosclerotic diseases,and the remodelling mode of atherosclerotic plaques is closely related to the occurrence of stroke.Positive remodelling(PR)is an outwards compensatory remodelling where the arterial wall grows outwards in an attempt to maintain a constant lumen diameter.For a long time,it was believed that the degree of stenosis can accurately reflect the risk of ischaemic stroke[3-5].Previous studies have revealed that lesions without significant luminal stenosis can also lead to acute events[6,7],as summarized in a recent meta-analysis study in which approximately 50%of acute/subacute ischaemic events were due to this type of lesion[6].Research[8,9]has pointed out that the PR of plaques is more dangerous and more likely to cause acute ischaemic stroke.Previous studies[10-13]have found that there are specific vascular remodelling phenomena in the coronary and carotid arteries of diabetic patients.However,due to the deep location and small lumen of intracranial arteries and limitations of imaging techniques,the relationship between intracranial arterial remodelling and diabetes is still unclear.In recent years,with the development of magnetic resonance technology and the emergence of high-resolution(HR)vascular wall imaging,a clear and multidimensional display of the intracranial vascular wall has been achieved.Therefore,in this study,HR wall imaging(HR-VWI)was used to display the remodelling characteristics of bilateral middle cerebral arteries and basilar arteries and to explore the factors of intracranial vascular remodelling and its relationship with diabetes.
基金This work was supported by Bureau of International Cooperation, NSF of China (2002008) and Science and Technology Funds of Liaoning Province (20022140).
文摘Objective To analyze the forces of rotational wall vessel （RWV） bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor. Methods The motion of the microcarrier in the rotating wall vessel （RWV） bioreactor with both the inner and outer cylinders rotating was modeled by numerical simulation. Results The continuous trajectory of microcarrier particles, including the possible collision with the wall was obtained. An expression between the minimum rotational speed difference of the inner and outer cylinders and the microcarrier particle or aggregate radius could avoid collisions with either wall. The range of microcarrier radius or tissue size, which could be safely cultured in the RWV bioreactor, in terms of shear stress level, was determined. Conclusion The model works well in describing the trajectory of a heavier microcarrier particle in rotating wall vessel.
文摘This study presents an analytical solution of thermal and mechanical displacements, strains, and stresses for a thick-walled rotating spherical pressure vessel made of functionally graded materials (FGMs). The pressure vessel is subject to axisymmetric mechanical and thermal loadings within a uniform magnetic field. The material properties of the FGM are considered as the power-law distribution along the thickness. Navier’s equation, which is a second-order ordinary differential equation, is derived from the mechanical equilibrium equation with the consideration of the thermal stresses and the Lorentz force resulting from the magnetic field. The distributions of the displacement, strains, and stresses are determined by the exact solution to Navier’s equation. Numerical results clarify the influence of the thermal loading, magnetic field, non-homogeneity constant, internal pressure, and angular velocity on the magneto-thermo-elastic response of the functionally graded spherical vessel. It is observed that these parameters have remarkable effects on the distributions of radial displacement, radial and circumferential strains, and radial and circumferential stresses.
文摘In order to provide an experimental foundation and pathological base for earlyreconstruction of maxillofacial tissues defects after firearms wound using microsurgicalmethods,an experiment,was made to study the microvascular pathological changesthrough light and electron microscopy observation.In the experiment we found somepathological changes of small vessels in wounded region,such as mierothrombi forma-tion,endothelial loss,internal elastic membrane break and some degenerations,necrosis within endothelial and smooth muscle cells of vessel.The nearer the woundededge was,the more evident injury was.The microvascular injurous range was 3 cm dis-tant from wounded edge,which recovered in 7 days later after wounding.The experi-ment indicated that if we used the vascularized free tissue transfer to repair defects ofmaxillofacial firearms wounds,the pedicles of flap should be anastomosed to distant re-cipient vesseles which could be chosen beyond 3 cm from wounded edge.Thereconstructive operation should be done 7 days later after wound.
文摘A problem of couple motion between vessel wall and blood in the entrance regionof a tapered vessel is considered in this paper A mathematical model of co-coupleaction is formed for both motion of vessel wall and blood flow in the entrance regance regionof elastic vessel with tapered angle. Under the situation that the relative boundary conditions are satisfied a.set of velocity distribution formula. pressure distributionformula for the blood flow in a tapered elastic vessel are derived. Some importantconclusions are obtained.
文摘This paper discusses the stresses developed in a thin-walled pressure vessels. Pressure vessels (cylindrical or spherical) are designed to hold gases or liquids at a pressure substantially higher than the ambient pressure. Equations of static equilibrium along with the free body diagrams will be used to determine the normal stresses in the circumferential or hoop direction and in the longitudinal or axial direction. A case study of internal pressure developed in a soda can was determined by measuring the elastic strains of the surface of the soda can through strain gages attached to the can and connected to Strain indicator Vishay model 3800.
文摘脑小血管病(cerebral small vessel disease,CSVD)是一组临床、影像、病理综合征,主要累及颅内小血管,起病隐匿。CSVD与卒中、认知下降、情感障碍、步态异常及尿便失禁密切相关,给家庭和社会带来沉重的疾病负担和经济负担。但CSVD的致病机制仍不明确,临床诊断标准不统一,临床诊疗和试验研究面临重大挑战。本文旨在汇总当前CSVD的可能病因、发病机制和临床诊疗研究的进展及局限性,展望CSVD未来可能的临床研究方向。
