• Volume 13,Issue 3,1998 Table of Contents
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    • THE MECHANICAL ANALYSIS OF GRAVITATE FLOW LOOP SYSTEM FOR A PARALLEL PLATE FLOW CHAMBER

      1998, 13(3):129-124. DOI: 10.3871/j.1004-7220.1998.3.124.

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      Abstract:A kind of flow loop system of parallel plate flow chamber to employ gravitate of pouring were analyzed in this paper. According to experimental result, corresponding coefficient of the resistance was determented. The relations pouring height with shear stress, Reynolds number and inlet length were obtained.

    • RELATIONSHIP BETWEEN REFERENCE VALUE OF CHINESE ADULT AND YOUNG PEOPLE'S HEMATOCRIT AND GEOGRAPHICAL FACTORS

      1998, 13(3):135-139. DOI: 10.3871/j.1004-7220.1998.3.139.

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      Abstract:In order to supply a basis for uniting the reference value standard of Chinese adult and young people's hematocrit,a research is made about relationship between the reference value of Chinese healthy adult and young people's hematocrit and five geographical factors, which are determined by the way of wintrobe lows. It is found that altitude is the main factor affecting the reference value of Chinese adult and young people's hematocrit.As the altitude increases gradually, the reference value of Chinese adult and young people's hematocrit also increases gradually, and the correlation is quite obvious.Applying the method of mathematical regression analysis, two regression equations are given out. If geographical values are obtained in some area, the refbrence value of Chinese adult and young people's hematocrit of this area can be reckoned using regression equations.Furthermore, according to the similarity of the reference value of Chinese adult and young people's hematocrit, taking the altitude as the main dividing basis and considering effects of other geographical factors and population distribution, China can be divided into six regions: Qingzang,Southwest, Northwest, Southeast, north and Northeast region.

    • HEMODYNAMICS STUDY ON TIPS FOR PORTAL HYPERTENSION

      1998, 13(3):140-146. DOI: 10.3871/j.1004-7220.1998.3.146.

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      Abstract:Transjuguler Intrahepatic Portosystemic Shunt (TIPS) is one of effective surgeries for portal hypertension. A lumped parameter mathematical model of the splanchnic circulation was presented to study TIPS hemodynamics. Firstly the hemodynamics parameters of portal Hypertension were calculated according to both Back word Mechanism and Forword Mechanism. Then the hemody nanmics parameters of portal system after TIPS were calculated. The variation of these hemodynamics parameters with cirrhosis and effection of TIPS shunt resistance on it were analysised. It is shown that the results were accord with clinical measurement, and the model presented in this paper can be applied to hemodynamics mechanism study of portal hypertension and other shunt surgeries,and can supply information for clinical application.

    • AN STUDY ON INIYIAL STAKILITY OF THREADED ACETABULAR PROSTHESIS

      1998, 13(3):147-153. DOI: 10.3871/j.1004-7220.1998.3.153.

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      Abstract:Objective:The design and initial stability of threaded acetabular prosthesis was studied in this paper. Method: The initial stability of threaded acetabular component was tested on the biomechanical test system. The threaded cup was fixed by direct rotation, the control group smooth acetabular cup was fixed with three cancellous screws. The forces moving prosthesis 100μm were tested at three direction of axial, clockwise and anti-clockwise. Results: The study shows that the threaded acetabular prosthesis has excellent initial stability with significant difference in statistics and provide theoretical basis for this prosthesis applied in clinical practice.

    • PROTECTIVE EFFECT OF GROWTH HORMONE FOR UPPER TIBIEN MECHANICAL PROPERTIES OF OVARIECTOMIZIED RATS

      1998, 13(3):154-156. DOI: 10.3871/j.1004-7220.1998.3.156.

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      Abstract:This study uses vertical compressive tests to observe the protective effects of different recombinant human growth hormone on for upper tibian mechanical properties of rats 3 months after ovariectomy and compared with estrogen therapy. Results:1.mechanical strength of upper tibiae obviously decreased after ovariectomy. 2.Middle and high doses of growth hormone could obviously increase mechanical strength of upper tibien of OVX rats.3.Estrogen and low dose of growth hormone had no influence on upper tibiae mechanical strength of OVX rats. The protective effects of growth hormone may be contributed to increment of bone mass of cancellous and cortical bone.

    • AN ESTIMATING METHOD FOR ARTERIAL TRANSVERSE IMPEDANCE

      1998, 13(3):157-163. DOI: 10.3871/j.1004-7220.1998.3.163.

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      Abstract:The arterial transverse impedance is an important hemodynamic parameter, but studies and experimental results on which are much lacking. In this paper a method to determine the arterial transverse impedance through the arterial compliance of unit length vessel is jointly, with the related data of transverse impedance in the canine arteries including carotid、femoral artery、and aorta. These results agree well with the experiments of Milnor et al(1978) and Busse et al(1979) in vivo, which showed the method given in this study is simple and useful for the determination of vascular transverse impedance.

    • COMPARSION OF FEMORAL BIOMECHANICS INFLUENCED BY EXERCISE, CALCIUM AND ESTROGEN IN OVARIECTOMIZED RATS

      1998, 13(3):164-168. DOI: 10.3871/j.1004-7220.1998.3.168.

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      Abstract:Objectives:To assess and compare the influence of exercise, calcium and estrogen on biomechanics of femurs in ovariectomized rats. Material and Method: Nine groups were established: (1)Normal Control group;(2)Osteoporosis model(OVX), (3)Combined Exercise and Calcium (Ex-Ca group); (4)Exercise-1 group;(5)Exercise-2 group;(6)Exercise Control Normal group (Ex-C), (7)Immobilization group (I group), (8)Female Hormone group (H group) and (9)Calcium group. Parameters of biomechanics were measured and analyzed. Results:The result of biomechanic tests showed that:(1)No significant difference was observed in all parameters except Flexibility Coefficient between Normal Control group and all groups related to exercise, calcium and estrogen. (2)No significant difference was obtained between E-Ca group and Normal group in all parameters. (3)No significant difference was showh among all 4 groups related to Exercise in all parameters. (4)biomechanic test showed that Flexibility in H-group was worse th...更多an in Normal group, indicating that the biomechanic charaters in H group were not good as those in exercise groups. (5)There was significantly difference between I-group and all exercise groups in each parameter. Concludsion:Exercise was showed to be independent effects for improving biomechanic nature during the growing stage and early and middle stage after ovarietomy, providing valuable information for designing rational exercise scheme to prevent postmenopausal osteoporosis. 还原

    • A EXPLORATION OF THE REASON ON DEFORMATION OF EGGS OF ENTEROBIUS VERMICULARIS IN PARAFFIN-SECTION

      1998, 13(3):169-172. DOI: 10.3871/j.1004-7220.1998.3.172.

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      Abstract:objective: To explore the cause of the eggs shell of E.vermicularis presented deformation during the making of the sample of paraffin section. Methods:Based on the morphologic feature of eggs shell and the recived pressure which was presented during the sample of eggs was made, the internal stress of eggs was analysed by meaus of the theory of elasticity-plastic mechanic. Result and Conclusion: The permanent deformation of egg-shell in paraffin-section caused by an overpressue bring to bear on the egg-shell out during the sample was made using improper technigue. The most deformed place of egg-shell were located in the lateral.

    • THE RELATIONSHIP BETWEEN GAP WIDTH(GW) AND ACTUAL DEFECT LENGTH(ADL) OF FEMORAL ARTERY AND VEIN IN RABBIT MODELS

      1998, 13(3):173-178. DOI: 10.3871/j.1004-7220.1998.3.178.

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      Abstract:Objective:To investigate the relationship between gap width(GW) and actual defect length(ADL) of femoral artery and vein. Methods:The influence of actual isolated length(ACIL) on GW was investigated in section A. Twenty-four femoral arteries (veins) in 12 rabbits were randomly divided into three groups. A range of 15.0mm, 25.0mm and 35.0mm of artery(vein) was isolated from peri-vascular connective tissues(including femoral nerve and vein) and arterial (venous) brallches respectively to clear off longitudinal vascular tedlering in different groups. Apparent isolated lengh (ApIL), increased isolated lengal (IIL) and GW were measured after the artery was transected at its middle portion and stretch ratio(λ) was caculated. The influence of ADL on GW was investigated in section B. Eighteen femoral arteries (veins) in nine rabbits were randomly divided into three groups (AcIL=35.00mm). A segment of 5.0mm, 15.0mm and 25.0mm long arteries (veins) at physiological tension was resected respectively. ApIL. IIL and GW were measured. Results:IIL and λ were unchallgeable while a linear relationship existed between GW and AcIL (GW=AcIL· (1 -1/λ) in statistics in section A. In section B, ADL didn't influence ApIL and IIL but increased GW linealy (ΔGW=ΔADL/λ) in statistics. Conclusion: An adaptive relationship may exist between GW, AcIL and ADL within 35.0mm AcIL range of rabbit's femoral vessel: ADL=AcIL- (AcIL+IIL- GW)·λ orADL= (ApIL-IIL)-(ApIL - GW)·λ. (λa=1.58, λv = 1.64, IILa= 3.85mm, IILv= 3.39mm).

    • E VALUTION OF INTERMAL FIOATIVE EFFECT FOR PEDICULAR SCREW IN BIOMECHANICE

      1998, 13(3):179-184. DOI: 10.3871/j.1004-7220.1998.3.184.

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      Abstract:Aim To seek the fixative relation between the pedicular Screw and the verterbral bodies and to furnish the basis of the improve for pedicular screw. Methods: the five not alike pedicular screw were evaluted With three dimensional limited element method. The pullout test and boundary surface stree measure were taken on the specimens of 9 cadaverice thareco Lumbar Result:the pullout power and boundary surface shearing stress of RF. UT, steffee, Dick, et al, were remarkabl difefrent(p<0.01) It was explain for heinfluence factors of the pedicular screw fixation were the shape,screw parameter, bone density and tightening up pitching moment. Conclusion: It was nessesery to increase the external diameter. deepen and the Length of pedicular screw according to the differece patients.

    • MEASUREMENT OF INTERFRAGENTRY MICROMOTION INDUCED BY MECHANICAL VIBRATION UNDER INTERNAL FIXATIONS AND ITS CLINICAL RELEVANCE

      1998, 13(3):185-188. DOI: 10.3871/j.1004-7220.1998.3.188.

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      Abstract:The interfragmentary micromotions in seven osteotomized cadaveric femurs were measured by using of strain accelerometers to study the effect of mechanical vibration on them under plate fixation or intramedullary nailing. The results showed that this measurement method with accelerometers was considerably accurate. It was confirmed that mechanical vibration could induce interfragmentary micromotion under nailing, but not under plate fixation. The negative curvilinear coorelation was found between vibration frequency and micromotion. Therefore, the choice of suitable vibration frequency deserves further researches if mechanical vibration is considered to be used in clinical practive.

    • A CLINICAL STUDY OF CBA EXAMINATION IN PATIENTS OF CEREBROVASCULAR DISEASE AND ITS CAUSATIVE AILMENTS

      1998, 13(3):189-192. DOI: 10.3871/j.1004-7220.1998.3.192.

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      Abstract:Patients of cerebrovascular disease (CVD) and its causative ailments were examined with a Cerebrovascular Blood-Dynamics Analyzer(CBA,CV-300).Positive rates were between 92.5 to 98.5%.Cerebral pressure (CP) increased in most patients of cerebral hemorrhage, and arterial sclerosis were detected in nearly all of cerebral infarction cases.In Hypertension,abnormalities of cerebrovascular hemodynamics indices (CVDI) were bilateral and symmetrical, and their marked asymmetry was often the omen of stroke. Abnormalities of CVDI were coinsident with focus localyzation by CT in most cases, and they appeared earlier than CT's localyzation, so they have certain value in early stage diagnosis.

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