摘要：Using FX-4000 strain unit, the prolieration in human lung adenocarcinoma A549 cells that underwent mechanical strain of different waveform、frequency and duration were studied. Image analysis revealed that cellular proliferation rate(PR) reduced significantly after cells were subjected to square wave with 0～20% elongation at frequency 30,40,50 and 60 cycles/min for 2h. The PR had no distinct difference at heart wave , triangle wave and sine wave group compared with control. It is concluded that square wave and higher frequency play an important role in inhibiting A549 cells proliferation.
摘要：The advantages and disadvantages of genetic algorithm and BP algorithm are introduced. A neural network based on GA-BP algorithm is proposed and applied in the prediction of protein secondary structure, which combines the advantages of BP and GA. The prediction and training on the neural network are made respectively based on 4 structure classifications of protein so as to get higher rate of predication-the highest prediction rate 75.65%, the average prediction rate 65.04%.
摘要：Level Set methods are robust and efficient numerical tools for resolving curve evolution in image segmentation. This paper proposes a new image segmentation algorithm based on Mumford-Shah module. The method is used to CT images and the experiment results demonstrate its efficiency and veracity.
摘要：The effect of age-related bone loss on the structural capacity of the proximal femur were investigated by Finite Element Analysis(FEA). Four bone loss patterns were considered. These were "uniform cortical bone loss", "neck cortical bone loss", "intertrochanteric cortical bone loss" and "uniform trabecular bone loss". The results show that the two "non-uniform cortical bone loss" patterns are more dangerous than the "uniform cortical bone loss" pattern, and that the cortical bone loss in intertrochanteric region is associated with a greater reduction in cortical failure load than the cortical bone loss in the femoral neck. The trabecular bone loss causes a limited decrease in both cortical failure and trabecular failure loads. This research should be helpful to the clinical assessment of femur fracture risk due to age-related bone loss.
摘要：Objective: The aim of this experiment is to study the effect of three methods of surface modification on the corrosion resistance of commercial pure Titanium when used in oral environment for half a year. Method: 48 specimens of pure titanium were made and divided into four groups randomly, one group was selected randomly as Group Ⅰ(control group), the other three groups were treated by three methods of surface modification individually, Group Ⅱ: heating oxidation in air(400℃,30min.), Group Ⅲ : anodization(45 volts, 10 min.), Group Ⅳ: TiN coating(firing temperature 200℃ , total coating time 62min.). Six edentulous volunteers with healthy oral mucosa participated in the in vivo study. One testing piece from each group was selected and fixed in the polished surface of upper complete dentures. Dynamic polarization curves were traced with electrochemical method after the specimens were placed either in oral cavity or in air for 6 months. Results: After all specimens were used, Ecorr altered in every group , Ecorr from high to low were in turn: TiN coating group ＞ heating oxidation group ＞ anodization group ＞control group, no obvious passive potential Ep and Ip was found in control group.Heating oxidation in air exhibited similar Ep to anodization, but Ip was remarkably lower than that of anodization; TiN coating showed obviously different polarization curves compared with heating -oxidation group and anodization group, Ecorr was positive, and no Ep and Ip was found. Conclusion: Under present experimental condition, all the three treatment methods could enhance corrosion resistance of pure titanium in oral environment, heating oxidation in air exhibited better resistance to corrode than anodization, TiN coating possessed the most excellent corrosion resistance, even after exposed in oral condition for 6 months, there was little change of corrosion resistance. Therefore TiN coating could be adopted to improve corrosion resistance of pure titanium in oral environment.
摘要：Objective:This paper is to explore a method of transferring human SDF-1 and its mutant SDF-1/54 intrakine gene into COS-7 cells for determining their expression and subcelluar localization of the fusion protein. This could offer feasibility for inhibiting the metastasis of malignant tumors by phonotypic knockout for blocking functional expression of receptor on the cell-surface. Methods:Amplify the target gene with PCR from the constructed plasimid SDF-WT-Gly×4-Dec/PET-30a(+)with a C-terminal retention signal fragment KDEL. After the pcDNA3.1 /SDF-1/KDEL, pcDNA3.1 /SDF-1/54/KDEL, pEGFP/SDF-1/KDEL and pEGFP/SDF-1/54/KDEL eukaryotic expression vectors were constructed and the DNA sequence was accurate, they were transferred into COS-7 cells with liposome. The exogenous expressions were observed, fusion protein SDF-1/His and SDF-1/54/His were confirmed by Western blot, and the SDF-1/EGFP and SDF-1/54/EGFP were determined by Laser Scanning Confocal Microscopy. Results:Four expression vectors were constructed successfully, the fusion protein SDF-1/KDEL/His and SDF-1/54 KDEL/His expressed in COS-7 cells. Subcelluar localization analysis showed that SDF-1/KDEL/EGFP and SDF-1/54/KDEL/EGFP were located mainly in endoplasmic reticulum. Conclusion: Four expression vectors pcDNA3. 1/ SDF -1/KDEL, pcDNA3.1/SDF - 1/54/KDEL, pEGFP/SDF - 1/KDEL and pEGFP/SDF-1/54/KDEL were constructed successfully, which could express in eukaryotic cell and locate mainly in the endoplasmic reticulum.
摘要：This paper proposes a practical algorithms of plane cutting, stereo clipping and arbitrary cutting for 3D surface model reconstructed from medical images. In plane cutting and stereo clipping algorithms, the 3D model is cut by plane or polyhedron. Lists of edge and vertex in every cut plane are established. From these lists the boundary contours are created and their relationship of embrace is ascertained. The region closed by the contours is triangulated using Delaunay triangulation algorithm. Arbitrary cutting operation creates cutting curve interactively.The cut model still maintains its correct topology structure. With these operations,tissues inside can be observed easily and it can aid doctors to diagnose. The methods can also be used in surgery planning of radiotherapy.
摘要：The effects of various cartilage extracellular matrix on the construction of rabbit growth plate cartilage tissue in vitro were studied. The results show that collagen, proteoglycan and hyaluronic acid can promote the growth of cultured chondrocytes but the effects of various cartilage extracellular matrix(ECM)on chondrocyte differentiation are different. Collagen can promote the hypertrophy of chondrocytes while proteoglycan and hyaluronic acid inhibit the transition of mature chondrocytes into hypertrophied chondrocytes.
摘要：Traditionally, differentiation of syndromes of Traditional Chinese Medicine (TCM) mainly depends on the information obtained from four diagnosis methods. Now many physicochemical parameters are available in clinic. There exists great correlation between TCM syndromes and physicochemical parameters.The objective of the paper is to analyze the correlation between TCM syndromes and physicochemical parameters quantitatively. Correlation analysis has been widely studied and many analysis methods have been developed. Mutual information based on entropy can measure arbitrary dependence between variables. It has been applied to many kinds of fields, especially to pattern recognition. But most works are restricted to discrete variables and little work has been done to study the relation between discrete and continuous variables. A novel algorithm is proposed to calculate the mutual information between discrete and continuous variables. It is used to analyze the correlation between TCM syndromes and physicochemical parameters.
摘要：Tissue engineering basically made up growing the relevant cell in vitro and extracellular matrix. A major goal of tissue engineering is to preparate porous three dimension scaffold for cell proliferate, migrate, differention and to form the structure of desirable tissue and organ. In this study, the effects of various content and macromolecular weight of PEG to chitosan were investigated and evaluated. The pore morphology of chitosan was controlled by changing the concentration and macromolecular weight of PEG.Chitosan porous scaffold has interconecting porosity. The pore morphology can be controlled with varying PEG concentration and macromolecular weight. The pore size is between 10 ～ 50 um, the degree of swelling in water is 85.70%.
摘要：In this study Digital Image Correlation (DIC) was adopted to evaluate the mechanical properties of bovine hoof horn. Using specific process, tensile specimens comprised of Zones 4 and 5 of the sole were excised from the claws of the front and rear hooves of a mature Black Angus cow. After extraction the specimens were conditioned to obtain horn with relative moisture content of either 0 % (dry)or 100% (wet) and then subjected to uniaxial tension to failure. The average elastic modulus (E) of all "dry" and "wet" hoof horn was 2870 ± 460 MPa and 102 ± 34 MPa respectively. Similarly, the average proportional limit stress (σ) was 29.0 ± 4.8 MPa and 1.4 ± 0.3 MPa respectively. Although the mechanical properties were dependent on distance from the dermal -epidermal junction, the influence of moisture on mechanical behavior was far greater.
摘要：Developing a shear thinning non-Newtonian fluid to substitute blood is desirable in studies of biomedicine engineering since blood is a shear thinning nonNewtonian fluid that exhibits both viscous and elastic properties, and generally not available in large volume. The rheological properties of aqueous Xanthan gum with different concentrations and temperatures were studied in present paper. The results show that aqueous Xanthan gum is a non-Newtonian fluid which displays remarkable shear thinning behaviour and is a suitable blood analog fluid. There is a power law distribution relationship between shear stress and shear rate, and the higher the solution concentration is, the more strongly it displays shear thinning behaviours. Viscosity values of aqueous Xanthan gum increase with the solution temperature decrease or with the solution concentration increase in linearity. Moreover at the temperature of 37℃, aqueous Xanthan gum with concentration of 0.4‰ and 0.6‰ matches human blood best in rheological properties. According to the resuits, the viscosity expression varied with temperature and concentrition is obtained, and the stability of Xanthan gum solution is discussed.
摘要：The degradation of chitosan ( DD of 72.05%) with aid of cellulase was carried out under the conditions of 45℃, pH 5.0 and a ratio of 1:15( chitosan/enzyme). The results showed cellulase could degrade chitosan efficiently. Viscosity of chitosan was decreased very quickly and reducing sugar released was increased with time during degradation. By using the membrane, the separation of the hydrolysis mixture was studied. Rejection of protein can be reached to be 99.74%.65.9% of low-molecular-weight chitosans was less than 2 kDa. Solubility of low-molecular-weight chitosan was found to be better than chitosan and transmittance could reach to be more than 95 % in entire range of pH 1 ～ 13.
摘要：This paper introduces the techniques of direct volume rendering in VTK and discusses ray-casting-the most popular technique of direct volume rendering. The visualizations for medical volumetric data by three functions of raycasting are offered. Visualization effects prove that VTK is easy to get satisfied results with good quality in short time.
摘要：The recognition of electroencephalogram (EEG) signals is the key of brain computer interface (BCI).Aimed at the problem that the recognition rate of EEG by using support vector machine (SVM) is low in BCI,based on the assumption that a well-defined physiological signal which also has a smooth form"hides" inside the noisy EEG signal,a Quasi-Newton-SVM recognition method based on Quasi-Newton method and SVM algorithm was presented.Firstly,the EEG signals were preprocessed by Quasi-Newton method and got the signals which were fit for SVM.Secondly,the preprocessed signals were classified by SVM method.The present simulation results indicated the Quasi-Newton-SVM approach improved the recognition rate compared with using SVM method; we also discussed the relationship between the artificial smooth signals and the classification errors.
摘要：In order to analyze the experimental cardiovascular signal with high accuracy,a system,integrating real-time monitoring and off-line further analysis,was developed and verified.The design,data processing and analysis methods as well as testing results are described.With 5 sampling frequency choices and 8channel data acquisition,the system achieved high performances in beat-to-beat monitoring,signal processing and analysis.Tests were carried out to validate its performance in real-time monitoring,effectiveness of digital filters,QRS and blood pressure detection reliability,and RR-interval timing accuracy.The QRS detection rate was at least 99.46% for the records with few noises from MIT-BIH arrhythmia database using the algorithm for real-time monitoring,and no less than 96.43% for the records with some noises.In the condition that noise amplitude levels were less than 80%,the standard deviations for RR-interval timing were less than 1 ms with a generated ECG corrupted with variousnoises from MIT-Bm Noise Stress Test Database.Besides,the system is open for function expansion to meet further studyspecific needs.
摘要：With the rapid development of brain computer interface (simply called BCI),electroencephalography (EEG) will be another interesting bio-electrical signal applied in robotics after EMG.In order to realize it finally,the accurate measurement and pattern recognition of EEG signal must be a very important and elementary research objective.Based on our current researches and some reports from the other international colleagues in the field,we deeply discuss the basic characteristics of EEG signal,the development and selection of EEG measurement system,feature extraction and recognition methods of EEG signal,and then review EEG's applications in robotics as well as the future research trends in this paper.
摘要：Objective: Prepare cross-linked HA gels with higher mechanical stability,lower degradation velocity and desirable biocompatibility,so as to extend the usage of HA.Method: 1.Test molecular weight of HA (MrHA) by viscosimetry;2.Prepare cross-linked HA gels by DVS,GTA,DEC;3.Discuss the cross-linking and degradation procedure;4,evaluate the biocompatibility of the best HA gels.Results: The mechanical stability and durability to degradation of HA-DVS gels are superior to those of other gels,and when HA :DVS = 40:1 (g/g),at 35℃ and in 0.2M NaOH solution,the HA-DVS gel shows the best mechanical stability,and its cytotoxicity reaches class I,hemolysis ratio is lower than 5 %.Conclusion:Our HADVS gel can be used to prepare biologic scaffolds.
摘要：Based on the variations of wavelet transform modulus maxima at multi-scales,the singularity of chaotic signals are studied,and the singularity of these signals are measured by the Lipschitz exponent.In the meantime,a nonlinear method is proposed based on the higher order statistics,on the other aspect,which characterizes the higher order singular spectrum (HOSS) of chaotic signals.All computations are done with Lorenz attractor,Rossler attractor and EEG (electroencephalogram) time series and the comparisions among these results are made.The experimental results show that the Lipschitz exponents and the higher order singular spectra of these signals are significantly different from each other,which indicates these methods are effective for studing the singularity of chaotic signals.
摘要：EEG inverse problem has great significance and importance for both clinical and research applications. It discusses EEG dipole source localization problems solved by nonlinear local optimization methods, such as Levenberg-Marquartb. This paper presents the relation between location errors and noise level on condition that the source number is known; if the source number is not known, the selected number in model may not equal to the actual one, and a computation is carried out and a corresponding discrimination criteria is proposed. Computer simulation demonstrates that Levenberg-Marquardt algorithm is better than global methods if the source number is small.
摘要：Objective:To assess the influence of mimic cardiac rate on hydrodynamics of the different mechanical prosthetic cardiac valves. Methods: US-made CarboMedics bileaflet valve and China-made Jiuling bileaflet valve and C-L tilting disc valve have been tested in a pulsatile flow simulator in the aortic position. The testing condition was set at the mimic cardiac rate of 55 beats/min,75 beats/min,100beats/min and a constant mimic cardiac output of 4L/min. The mean pressure differences (△P) ,leakage volumes (LEV) and closing volumes (CLV) across each valve,and the effective orifice areas(EOA) have been analyzed. Results:Within the range of physiology,the △P,LEV and CLV were falling as the increasing of mimic cardiac rate,and the extent of variance was larger. The EOA was increasing with the increase of the mimic cardiac rate. It is a different response as the altering of the cardiac rate for the different type of the mechanical prosthetic cardiac valves.Conclusions:The change of the mimic cardiac rate can affect the hydrodynamics of the mechanical prosthetic cardiac valves. The hydrodynamics of the bileaflet valve prosthesis is better than the tilting disc valve.
摘要：By means of FEM, the physiological blood flow in coronary bypass graft is simulated. The stenosis in coronary artery is involved in the graft model,and the deformation of graft end to allow the surgical suture with a smaller diameter coronary is taken into consideration. The flow pattern, secondary flow and wall shear stress in the vicinity of anastomosis are analyzed. It is shown that a zone of low wall stress and high wall stress gradient exists downstream the toe. The floor opposed to the anastomosis is an area of high wall stress and high wall stress gradient. Both the toe downstream and the anastomosis bottom floor are prone to intimal hyperplasia.
摘要：Thermographic technique can be used to measure temperature distribution of body surface in real-time, non-contact and full-field, which has been successfully used in medical diagnosis, remote sensing, and NDT, etc. The authors have developed a thermographic experiment that can be applied to inspect the effect of action of acupuncture and qi-gong (a system of deep breathing exercises) by measuring the temperature of hand and arm. The observation is performed respectively by thermography for the dynamic changes of temperature of the arm and hand after acupuncture treatment and qi-gong treatment. Thermographic results show that the temperature on the collateral channels increases significantly. In the meantime, it can be seen that the above therapies of traditional Chinese medicine can stimulate the channel collateral system. This also contributes a new basis to the effect of action of the therapies of traditional Chinese medicine. The work shows that thermographic technique is a powerful tool for research in traditional Chinese medicine. In this paper, some thermal images are obtained from the persons treated with acupuncture and qi-gong.
摘要：The objective of this study was to produce the porous collagen-chitosan/Glycosanminglycans (GAG) for corneal ceil-seed implant as a three-dimensional tissue engineering scaffold to improve the regeneration corneas. The effect of various content of glycerol as form porous agent to collagen-chitosan/GAG preserved a porous dimensional structure was investigated. The heat-drying was used to prepare porous collagen-chitosan /GAG scaffold. The pore morphology of collagenchitosan/GAG was controlled by changing the concentration of glycerol solution and drying methods. The porous structure morphology was observed by SEM. The diameter of the pores form 10 to 50 μm. The highly porous scaffold had interconnecting pores. The corneal cell morphology was observed under the light microscope. These results suggest that collagen-chitosan/GAG showed that corneal cell have formed confluent layers and resemble the surface of normal corneal cell surface.
摘要：This paper briefly introduces the collection and recognition of biomedical signals, designs the method to collect FM signals. A detailed discussion on the system hardware, structure and functions is also given. Under LabWindows/CVI, the hardware and the driver do compatible, the hardware equipment work properly actively. The paper adopts multi threading technology for real-time analysis and makes use of latency time of CPU effectively, expedites program reflect speed, improves the program to perform efficiency. One threading is collecting data; the other threading is analyzing data. Using the method, it is broaden to analyze the signal in real-time. Wavelet transform to remove the main interference in the FM and by adding time-window to recognize with BP network; Finally the results of collecting signals and BP networks are discussed. 8 pregnant women' s signals of FM were collected successfully by using the sensor. The correct of BP network recognition is about 83.3% by using the above measure.
摘要：Tongue diagnosis is one of the most precious and widely used diagnostic methods in Traditional Chinese Medicine (TCM). However, due to its subjective, qualitative and experience-dependent nature, the studies on tongue characterization have been widely emphasized. This paper surveys recent progresses in analysis of tongue manifestation. These new developments include the cross-network and cross-media color reproduction of tongue image, the automatic segmentation of tongue body based on knowledge, the automatic analysis of curdiness and griminess for the tongue fur and the automatic analysis of plumpness, wryness and dot -thorn of tongue body. The clinic experiments verify the validity of these new methods.
摘要：Herbs of activating blood circulation to remove blood stasis(ABCRBS) are a category of over 10% in the modern Chinese Pharmacopoeia. A new borderline discipline, biomechanopharmacology, is shaping by the efforts of applying biomechanics in pharmacological studies of ABCRBS herbs. Biomechanics is involved in modeling of blood stasis syndrome (BSS) with mechanical force induced injury and model evaluation by shear stress monitoring for blood coagulation. Investigations showed that tetramethylpyrazine (TMP) contained in Ligusticum chuanxiong Hort and diallyl trisulfide (DT) extracted from garlic demonstrated inhibiting characteristics on vWF mediated platelet activation and thrombus formation occurring under high shear rates. The effect of TMP on shear-induced platelet aggregation might be due to inhibition of calcium channel activity since it showed significant inhibition on intracellular level of calcium demonstrated by laser confocal microscope. The combined effects of TMP and shear stress on rat cerebral microvascular endothelial cell (rCMEC) were investigated by various doses of TMP incorporated with different levels of shear stress generated by a rotational coneplate rheometer. The results indicated that apoptosis of rCMECs could be restrained by a combination of medial level of shear stress with a suitable dose of TMP. To study the influences of shear stress, pressure and TMP on angiogenesis of vascular endothelial cell, cultured rCMEC was pretreated in a flow chamber with independent adjustment for levels of shear stress and pressure, and then 3D cultured on Matrigel. The results indicate that combined effects of shear stress, pressure and TMP may influence angiogenesis significantly. We believe that research on interactions among blood shear stress, secretion of endothelial cell, and pharmacodynamics will be an interesting area of biomechanopharmacology. Herbs of ABCRBS and their extracts for protecting endothelial cells to maintain their normal functions are expected.
摘要：Photodynamic therapy(PDT) is a new medical technology, the study on photodynamic therapy was in full swing in the past two decade. Scientists have made great progress in it. Photosensitizer,oxygen and light source play important role in photodynamic therapy.PDT is a light activated chemotherapy. A photon is adsorbed by a photosensitizer which moves the drug into an excited state. The excited drug can then pass its energy to oxygen to create a chemical radical called "singlet oxygen". Singlet oxygen attacks cellular structures by oxidation. Such oxidative damage might be oxidation of cell membranes or proteins. When the accumulation of oxidative damage exceeds a threshold level,the cell begins to die.Photodynamic therapy allows selective treatment of localized cancer. PDT involves administration of a photosensitizer to the patients, followed by delivery of light to the cancerous region. The light activates the agent which kills the cancer cells. Without light,the agent is harmless.As a new therapy,photodynamic Therapy has great Advantage in treating cancers. 1. PDT avoids systemic treatment. The treatment occurs only where light is delivered, hence the patient does not undergo go needless systemic treatment when treating localized disease. Side-effects are avoided, from losing hair or suffering nausea to more serious complications. 2. PDT is selective. The photosensitizing agent will selectively accumulate in cancer cells and not in surrounding normal tissues.Hence ,there is selective targeting of the cancer and sparing of surrounding tissues.3. when surgery is not possible. PDT kills cancer cells but does not damage collagenous tissue structures,and normal cells will repopulate these structures. Hence,if a patient has cancer in a structure that cannot be removed surgically(eg. ,the upper bronchi of the lung) ,PDT can still treat the site. 4. PDT is repeatable. Unilke radiation therapy, PDT can be used again and again. Hence,it offers a means of longterm management of cancer even if complete cure is not attainable.
摘要：Because of the incomparable merits (nontoxicity, non-remainder,fast transfer mass) of supercritical carbon dioxide fluid technique(SC-CO2), it was used to developed a series of novel biodegradable tissue engineering scaffold materials in this research. The novel PLA/chitosan composite materials could be molded to different shapes, and the porosity of the materials were over 200 μm and connected. Chondrocyte cultivation, subcutaneous and intramuscular implantation were mainly discussed this paper. The results showed that the cells could well adhere,grow and multiplicate on the surface of the materials, which indicated good biocompatibility of the composite materials. The plantation test revealed that the PLA materials had already dismissed 2 month late in the body, while the composite materials could still keep certain strength and shape, and the most important things is the response of the tissue toward the implanted PLA/chitosan composite materials was mild and had far less inflammation than PLA materials. 8 to 16 weeks later, fiber membrane was stable; degradation of the materials was seen clear and tissue had already spread into it.
摘要：Based on the one-dimensional and unsteady-state Krogh model, this paper investigates mass transfer of artificial kidney under three blood cycle modes during the course of hemodialysis. The variations of the permeable solute clearance with increasing time and the dialysis time with increasing blood flux are simulated in detail ,and then one optimal blood cycle mode is acquired. The results are very important to improve the clinical dialysis efficiency of artificial kidney.
