Objective To examine the segmental bone defects healing by ? TCP/rhBMP 2 composites with different degradation rate and discuss the relationship between osteogenesis and degradation of ? TCP in vivo. Methods Three kinds of ? tricalcium phosphate(? TCP) with different degradation rate (? TCP1-3) were prepared by means of different techniques. ? TCP/rhBMP 2 composites with different degradation rate(? TCP1/rhBMP 2 and ? TCP2/rhBMP 2)were obtained by combining ? TCP1, ? TCP2 with recombinant human bone morphogenetic protein 2(rhBMP 2), respectively. ? TCP1/rhBMP 2, ? TCP2/rhBMP 2, ? TCP1, ? TCP2 and ? TCP3 were used to repair 15 mm radial segmental defects in 81 Chinese rabbits. When the samples were harvested in 4, 8, 16 and 24 weeks after surgery, a series of examination were carried out, including the roentgenographical, histomorphological, biomechanical and computerized graphical analysis, energy dispersion analysis X ray (EDAX), and measurements of inorganic contents. Results Roentgenographically and histologically, all of the defects that had been treated with implants exhibited new bone formation, increasing with time. The quantity and rate of new bone formation in ? TCP1/rhBMP 2 group and ? TCP2/rhBMP 2 group were higher than those in group of ? TCP alone. The ability of new bone formation in ? TCP1/rhBMP 2 group was strongest. At 24 weeks the defects in ? TCP1/rhBMP 2 group were bridged with the appearance of marrow cavities, the inorganic contents and ratio of calcium to phosphate and biomechanical property in implants approached to those of normal bone. Although degradation occurred to some extent in ? TCP alone the degradation were faster in ? TCP/rhBMP 2 composites. At 24 weeks the degradation rate in ? TCP1/rhBMP 2 group and ? TCP2/rhBMP 2 group were 97.4%and 73.4%, respectively. The defects in blank controls were repaired only by fibrous tissue at 24 weeks. Conclusion ? TCP/rhBMP 2 composites with different degradation rate could repair segmental bone defects, and osteogenesis could accelerate the degradation of ? TCP in vivo.

Objective To improve the precision of the traditional segmentation of echocardiogram, by suppressing the influence from inherent speckle noises in medical ultrasonic images. Method An automatic segmentation method based on reconstructed morphology was proposed in this paper. First, the opening and closing operations by reconstruction were imposed to the ultrasonic image. Second, the top-hat operation was used to extract the bright and/or dark features and to find out the boundaries corresponding to these features, whereby implemented the automatic segmentation. Result The segmented echocardiogram had less artificial boundaries resulted from speckle noise, and could accurately be extracted the artery and ventricle. Conclusion The presented method can detect both dark and bright objects accurately, and the boundary has a fine continuity. In addition, the algorithm is also applicable to the extraction of sole bright/dark features, accordingly to reduce the complexity and time needed and to improve the accuracy.

During the preparation of functional gradient materials (FGM) with plasma immersion ion implantation-ion beam enhanced deposition (PIII-IBED), the combination strength between the coating and the substrate would be greatly affected by the implantation dose and the distribution of implanted ions in substrate. According to the requirements of FGM, an idea of multi grades energy implantation had been suggested, with which the Gauss peak could be moved toward the surface, and the concentration of implanted ions could be maximized at the surface. In this study, the distribution of carbon ions implanted into titanic alloy substrate have been simulated theoretically, and the tentative idea have been confirmed experimentally.
Alloys ; Carbon ; Coated Materials, Biocompatible ; chemical synthesis ; Computer Simulation ; Heart Valve Prosthesis ; Titanium

Studies on bioactive glass and glass-ceramic are important research high-lights in the field of biomedical materials. Due to their bioactivity, these materials can form a tight chemical bond with the living bone, when implanted. As a preeminent kind of these materials, A-W(Apatite/Wollastonite) bioactive glass ceramic has not only the excellent bioactivity and biocompatibility, but also the eminent mechanical properties, so it has been largely applied and developed in clinical practice. The development, preparation, properties, applications and the mechanism of its bond with bone are introduced in this paper. We will also put forward the prospect of the research and development of A-W bioactive glass ceramic.
Apatites ; chemistry ; Bone Substitutes ; chemistry ; Calcium Compounds ; chemistry ; Ceramics ; chemistry ; Mechanics ; Research ; Silicates ; chemistry ; Surface Properties

In order to evaluate diamond like carbon film (DLC), DLC containing Si, graphite, diamond film (DF), low temperature isotropic carbon film (LTIC) and SiC, we investigated the correlations between surface energy parameters and hemocompatibility indices such as kinetic clotting time, hemolysis and platelet consumption. An analysis of T-type correlation degree in the Grey system theory was performed. The results showed: (1) all of correlation degrees between kinetic clotting time and polar surface energy parameters were positive, but for critical surface tension, the correlation degree was negative; among five of surface energy parameters, interface tension had the highest relation degree (0.63) with kinetic clotting time, and critical surface tension (-0.43) took the second place; (2) on the contrary, all of correlation degrees between hemolysis and polar surface energy parameters were negative, but for critical surface tension, the correlation degree was positive; and that which had closer correlations with hemolysis were still interface tension (-0.43) and critical surface tension (0.29); (3) critical surface tension had the highest relation degree (0.68) with platelet consumption, and surface tension (0.32) took the second place; (4) kinetic clotting time possessed higher negative correlation degrees with hemolysis (-0.57) and platelet consumption (-0.36). These data indicate that kinetic clotting time depended on a balance between the polarity of surface and the limited humidifying of water on the surface, and that platelet consumption was based on good humidification and power polarity of surface, while hemolysis was promoted by the aid of chromatic dispersion action stemming from the surface and fully humidifying of water on the surface. There was "seesaw effect" between kinetic clotting time and hemolysis or platelet consumption, hence the hemocompatibility of carbonaceous biomaterials could be equivalently evaluated by using kinetic clotting time as an index. It has been confirmed: (1) successive occurrences, including adhesion, deformation and collection of platelets on the material surfaces as results of protein adsorption, are the major mechanism of blood coagulation of carbonaceous materials; (2) the hemocompatibility of carbonaceous biomaterials can be evaluated by using critical surface tension as an index. These findings may underpin the hemocompatibility evaluation of carbonaceous biomaterials based on surface properties.
Adsorption ; Biocompatible Materials ; chemistry ; Blood Platelets ; cytology ; Carbon ; chemistry ; Diamond ; chemistry ; Feasibility Studies ; Graphite ; chemistry ; Hemolysis ; Platelet Adhesiveness ; Surface Properties

In the present paper, adhesive test, morphology observation, classified counting and deformation index calculation of the platelets on seven DLC samples made by different processes were carried out after XPS analysis, respectively. Then the effects of carbon phase components on amounts and deformation index of the platelets adhered to the samples were investigated by using the analysis of T-type correlation degree in the grey system theory. It has been shown from results that the amounts and the deformation index of the platelets adhered to the DLC samples made by plasma source ion implantation-ion beam enhanced deposition (PSII-IBED) are obviously less than those of DLC samples made by plasma CVD. The correlation degrees (negative) between the DLC carbon phase and the amounts as well as the deformation index of platelets are much more than those of the other four carbon phase components; besides, larger correlation degrees (positive) only appear between the deformation index of platelets and the C-H carbon phase or C-O carbon phase. It has been indicated that: (1) the effect of DLC carbon phase on platelets adhesion is much greater than that of the other four carbon phase components, the key to improvement in the hemocompatibility of DLC is to increase the DLC carbon phase content; (2) it is necessary to restrain the form or decrease the C-H carbon phase content and C-O carbon phase content so as to control their promotive action on deformation of the platelets adhered to the surface of DLC; (3) using PSII-IBED process to prepare DLC is helpful to improving the hemocompatibility of DLC. These conclusions are essential for designing and improving the deposition process of DLC.
Biocompatible Materials ; Carbon ; chemistry ; Diamond ; chemistry ; Humans ; Male ; Materials Testing ; Models, Biological ; Platelet Adhesiveness

In the present paper, the influence of carbon phase components of three kinds of diamond like carbon (DLC) films, viz. DLC, DLC rich in graphite and DLC rich in diamond films, on adsorption of human serum albumin (HSA), human serum fibrinogen (HFG) and immunoglobin (IgG) was quantitatively analyzed by use of T-type correlation degree in the grey system theory. Through the analysis, the rational explanation for adsorptive amounts variations of the serum proteins with phase components in the experiment is reached and some essential conclusions have been obtained: (1) The effect of graphite phase and C-H phase on HSA adsorption are greater than that of other phase components; with the increase of these two phase coumponents, the adsorptive amounts of HSA decrease; (2) The powerful influence on HFG adsorption stems from DLC phase and C-O phase; with the decrease of DLC phase or the increase of C-O phase, the adsorptive amounts of HFG increase; (3) All of the carbon phase components have only limited influence on IgG adsorption in positive or negative fashion with a little difference in degree; (4) DLC phase has both effects of enhancing adsorption for HSA and weakening adsorption for HFG and IgG, thus its influence on the hemocompatibility of DLC films is much more important than that of other phase components.
Adsorption ; Carbon ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Diamond ; chemistry ; Humans ; Materials Testing ; Membranes, Artificial ; Serum Albumin ; chemistry ; Surface Properties

The design and development of multi-dimensional ultrasonic reconstruction and visualization system (MURVS) have been described in the present paper. This system is basically composed of four modules: the data input/output module, image segmentation and arrangement module, multi-dimensional reconstruction module, and the dynamic visualization module. At first, some algorithms used in the system are introduced by the authors, including the AVI segmentation algorithm, three-dimensional interpolation algorithm, and volume rendering algorithms. Then the key questions of techniques to be discussed are: how to design the main modules, how to solve the dynamic visualization problem, and how to implement the system. The experiments indicate that MURVS is able to reconstruct all three-dimensional data fields in one cardiac cycle of a patient within 4 seconds, and dynamically display the motion of the heart. It allows the medical professionals to select different parameters when observing the reconstructed results. This is very helpful for medical professionals to reach more accurate diagnoses of their patients' diseases.
Adult ; Algorithms ; Echocardiography, Three-Dimensional ; methods ; Female ; Humans ; Image Processing, Computer-Assisted ; methods ; Mitral Valve Stenosis ; diagnostic imaging

In order to clarify the mechanism of blood coagulation for carbonaceous biomaterials, the plasma rich in platelet was obtaining through the centrifugation of fresh human blood containing anticoagulant. Adhesive tests of platelets to surfaces of DLC, diamond film(DF) and graphite was carried out at 37 degrees C. Then, morphology observation, counting and deformation index calculation of the platelets adhering to surfaces of the three kinds of materials were analyzed by SEM. It has been shown that there is no any platelet on the surface of DLC, but on DF and graphite, a lot of platelets are observed with serious deformation of type III-V. The adhesive amounts of platelet on the surface of graphite are more than those on DF, but deformation index of platelets on the surface of DF is more than that on graphite. Three major conclusions have been obtained through comparative analyses with our previous researches and related literatures: (1) Adhesion, deformation and collection of platelets occurred in succession on material surfaces resulting from protein adsorption are the major mechanism of blood coagulation of carbonaceous materials; (2) Deformation degree of platelets is more important hemocompatibility index than consumption ratio of platelets for carbonaceous materials; (3) The purer the DLC, the better is the hemocompatibility. These conclusions possess important directive function for improving and designing carbonaceous materials used in artificial mechanical heart valves.
Biocompatible Materials ; Blood Platelets ; pathology ; Carbon ; Diamond ; Graphite ; Humans ; In Vitro Techniques ; Materials Testing ; Platelet Adhesiveness ; Surface Properties

Image interpolation techniques were widely applied in medical imaging for image generation and post processing. Firstly, traditional interpolation methods were listed out in the details of shape-based interpolation and dynamic elastic registration interpolation. Secondly, the characteristics, development and problems in interpolation of rotary scanning ultrasonic cardiac images were analyzed. The relation between interpolation and registration was stated. The analysis indicated that excellent methods in rotary scanning interpolation should be registration-based methods. At last, several evaluation methods about images interpolation were discussed.
Algorithms ; Echocardiography, Three-Dimensional ; methods ; Fourier Analysis ; Image Processing, Computer-Assisted ; methods