The concept of hemangioblast was proposed a century ago. The existence of hemangioblasts has been demonstrated recently in vitro by differentiation of mouse and human embryonic stem (ES) cell into em-bryoid bodies(EBs). In the developing embryo, a common progenitor, termed "hemangioblast", generates both hematopoietic and endothelial cell lineages. The in vitro differentiation of embryonic stem cells to hemangioblast is a powerful approach for studying the commitment of the hematopoietic and endothelial lineages. This review will summarize recent development in the studies on hemangioblast.

Vascular graft is an important component of vascular tissue engineering. In the past several decades, the scaffold materials for vascular tissue engineering have developed from simple natural materials to compound of degradable polymer and biological materials. Great progress has been made in material design and procossing. Electrospirming has been introduced to replace the manual processing. However, more work still needs to be done to make the method of design and processing more satisfactory. Main efforts should be put into the studies on improving the mechanical properties and biological functions of the scaffold materials.

Objective To study the effect of diabetes on spatial memory ability and spatial associative memory ability in rats. Methods 70 SD rats( 180±20 g) were randomly divided into 3 groups: control group,type1 diabetes group and type2 diabetes group. Type1 and type2 diabetic rat models were set up by streptozocin (STZ) intraperitoneal injection and high fat forage raise. The blood glucose was determined. After rat diabetic model established 1 month and 3 months, respectively, the Morris water maze experiments were implemented,including 4 days' place swimming and 1 day's space exploration. Results After 1 month, diabetic rats' spatial memory ability and spatial associative memory ability were not affected. After 3 months, in place swimming test,the escape latency of two diabetic rat groups was obviously longer than that of the control group (P＜0.05). From the second day of the experiment, escape latency of the control descended sharply, while that of the diabetic group descended slowly. There was no difference between type 1 and type2 diabetic groups in escape latency (P＞0.05). After 3 months, in the space exploration test, when rats were put into the maze from I quadrant which already trained, swimming time in the platform quadrant was shorter, the other parameter scores were lower of the two diabetic model groups, contrast to the control group (P＜0.05). The parameter scores of type2 diabetic group were lower slightly than type1 diabetic group. When rats were put into the maze from IV quadrant for which never trained, the parameter scores of two diabetic groups were lower than that of the control group (P＜0.05) and the total score of type 1 group was lower than that of type2 group. Conclusion The spatial memory ability and spatial associative memory ability of type 1 and type2 diabetic rats descended. In the experiment, the spatial memory ability of type2 diabetic rats was more significantly affected than that of type1 diabetic rats. By contrast,type 1 diabetic rats' spatial associative memory ability descended greatly than that of type2 diabetic rats.

Different cells could be utilized as seed cells in the construction of tissue-engineered skelet al muscle, which include satellite stem cells, myohlasts, embryonic stem cells and mesenchymal stem cells includ-ing bone marrow-derived stem cells, amniotic fluid-derived stem cells, and adipose tissue-derived stem cells. Seed cells from different origins are capable of trans-differentiating into myogenic cells or fusing with myogenic cells, expressing the surface antigen of sarcogenic cells, and participating in the regeneration of muscle fiber, both in vivo and ex vivo. This review gives a summarization of the recent progress in the research on seed cell source in skelet al muscle tissue engineering.

Gene chip is a recently developed high-throughput gene expression analyzing technique. Key techniques and new development of gene chip are reviewed in this paper, including carrier(or substrate) surface chemical modification, preparations of DNA fragment, preparation of gene chips, tagging of the probes, hybridization, and analysis of gene chips. Comprehensive introduction of advantages and disadvantages of various technical taches and elements are introduced in this article. Particular attention is paid to further improvement needed to promote the popularization and application of this technology.

In recent years,with the updating of radiation treatment equipment,more and more advanced and accurate equipments are used in clinics,improving the accuracy of the radiation treatment.But there is no improvement in diagnosis and treatment process,work efficiency and equipment application area of no improvement.The use of Siemens CTVision radiation treatment system can not only improve the accuracy radiation treatment,but also simplify the work process,shorten the diagnosis and treatment time and broaden the range of application equipment.With the high efficiency,more medical projects can be carried out.Hardware and software function of Siemens CTVision radiation treatment system are introduced in this review,with clinical application and medical projects developed on the basis of the system.Analysis of the new radiation treatment work patterns are carried out and the importance of the changes of decentralized polymorphism mode into the integration polymorphism mode in tumor radiation therapy are discussed in this article.

Objective To investigate the effect of fast-aging on the excitability of hippocampus CA1 neurons in mouse and the possible interaction between fast-aging and hippocampus. Methods Using brain slice and extracellular recording technique to record the firing of hippocampus CA1 neurons in fast-aging(SA M-P/8) and normal control mice, after preprocessing, neural firing train were obtained. Using neural firing rate and inter-spike-inter to investigate interaction between fast-aging and hippocampal neural firing. Results The neural firing rate of hippocampus CA1 neurons in fast-aging mice is (1.052±0.364) Hz(n=14), while the neural firing ratein normal control mice is (4.416±1.306) Hz(n=22). In fast-aging mice, 80.5% inter spike intervel(ISI) is longerthan 1sec, but in normal control mice, 95.6% ISI is shorter than 0.5sec. Conclusion The decreased firing rate of hippocampus CA1 and longer ISI observed in the fast-aging mice indicates that fast-aging significantly inhibit hippocampal CA1 neurons excitability.

As a novel functional material with great application values, magnetic nanobead has been in fast development in recent years. Magnetic nanobead is provided with characteristics of beth polymeric and mag-netic particles, so it can be detected easily fi'om the medium and can be easily located since they can move di-rectionally when motivated by external electric field. The magnetic nanobead is widely used in biomedical engi-neering research due to its unique physical and chemical properties which simplify the complex experiments op-erations and shorten the testing period.

ObjectiveTo study the feasibility of analyzing photosensitizers absorbing process by cells based on image processing technology.MethodsFluorescence images of Laryngeal cells were taken by inverted fluorescence microscope after adding photosensitizers for a certain time.Parameter L that reflects the fluorescence intensity of cells in different times was obtained and the calculation results were compared.ResultsThe fluorescence intensity of cells increased over time.Sobel operater and Otsu algorithm can both reflect the fluorescence intensity of images.ConclusionImage processing technology can effectively analyzes the process of photosensitizers absorbed by cells.

ObjectiveMatching pursuit algorithm(MAP),for its good parametric characterization,was applied in epileptic electroencephalography(EEG) to study time-frequency distribution.MethodsSimulation experiment of time-frequency analysis was carried out to verify the matching pursuit algorithm s superiority on frequency resolution and parametric characterization.Fourier transform,Wigner-Ville distribution and matching pursuit algorithm were applied to the time-frequency analysis on normal EEG and epileptic EEG to study epileptic discharge in the time-frequency plane and the results were compared.ResultsSimulation results showed that the matching pursuit algorithm obtained a better time-frequency distribution.Distributions of epileptic EEG and normal EEG had significant difference in time-frequency plane.ConclusionTime-frequency analysis based on matching pursuit can better reveal the EEG characteristics.