2015, 4(3):1-7. DOI: 10.12146/j.issn.2095-3135.201503001
Abstract:Multi-scale entropy was introduced to analyze the blood oxygen sequence under hypoxic environment. Compared with mean analytical method, blood oxygen sequence analysis based on multi-scale entropy can reflect the dynamic adjustment mechanism of body hypoxia better. Multi-scale entropy, which is different from sample entropy that just estimates the difference between sequence length m and m＋1 on the smallest scale and ignores other scales, calculates sample entropy of time series on multiple scales and reflects the irregular degree of time series on scales. The result shows that blood oxygen sequence analysis based on multi-scale entropy can identify human hypoxia endurance. This method is a reliable analytical method for studying the mechanism of hypoxic regulation of human body. The result also shows that repeated hypoxic stimulation will produce acclimatization effects on the human body which shows memory of hypoxia environment.
2015, 4(3):8-28. DOI: 10.12146/j.issn.2095-3135.201503002
Abstract:The explosive growth of social networks as convenient communication tools has played an increasingly important role in personal communications, marketing, political struggles, diplomacy and some other aspects. The popularity and huge influences attract much attention of the scholars into the social network research. Through statistics of the papers concerning social networks from the most famous international conferences and journals, we conclude the focuses of the social network research are information diffusion and securities. About the researches on information diffusion, there are four main questions including information diffusion model, factors, influence maximization and prediction. About the researches on security of social networks, there are two main questions including security of users and information. In security of users, spammer identification and cascading failures were discussed. The source identification and control strategy were included in security of information. The related papers of the conferences and journals were introduced and the main research results in the above aspects were stated. Then, the problems, challenges and trends of the information diffusion and securities, which will provide a meaningful guidance to the social network research, were obtained.
2015, 4(3):29-34. DOI: 10.12146/j.issn.2095-3135.201503003
Abstract:Optogenetics technology has the advantage of regulating the activity of specific cell population in milliseconds level, which provides a novel bioengineering tools for understanding the mechanism of the neural circuits and the pathogenesis of some neurological diseases and interventions treatment. Based on the characteristics of optogenetics, we developed a set of LED light stimulation system for optogenetics modified in vitro cell culture or brain slice. This device can remotely control stimulation parameters of LED arrays such as time, frequency, duty cycle, and simultaneously detect physicochemical properties of cultured cells.
2015, 4(3):35-44. DOI: 10.12146/j.issn.2095-3135.201503004
Abstract:Feature detection plays an important role in object detection and registration. For data registration, correspondences of different frames in the same scene should be found firstly. However, in many cases, there are not effective correspondences, which leads to incorrect registration. One of the effective solutions is to add marker manually in the scene. A method for detecting 2D marker (a black circle drew on paper for scene, hollow circular for point cloud) automatically in 3D point cloud (3D position information only) was proposed. First of all, add a 2D marker in real scene, and divide data set of 3D scene into segments by using region-growing segmentation. Then for each segment, detect 2D marker by extended RANSAC doing shape fitting. By this method, the 2D marker in 3D point cloud could be effectively detected without deforming or changing object. It provides simple and available features for the scene that is lack of features, laying a good foundation for next steps.
2015, 4(3):45-52. DOI: 10.12146/j.issn.2095-3135.201503005
Abstract:Peripheral nerve injury and amputation have plagued neurosurgeons and patients. Autologous nerve grafts has been known as the “golden rule” to repair severe lesions but is limited by the length and potentially losing functions originally from the donor nerves. Meanwhile, tissue-electrode interface was proposed to overcome the limitation of the traditional neural interface, but long autologous nerves with original functions are preferred. So finding out a substitute material to replace the autologous nerves as donor nerves becomes critical. Dorsal root ganglia (DRG) proved an ideal original material. In this report, we described a method to isolate the DRG explants from the spinal cord of SD rat, and coated the Aclar films with poly-D-Lysine (PDL) and poly-L-Lysine (PLL) respectively. Then the strategy of culturing the DRG explants on the coated Aclar films was introduced. An experiment was designed to investigate the growth of the DRG explants, specifically the DRG axons cultured on the two separately coated -Aclar films. The results of the experiment show that PDL has an advantage in coating the Aclar film for culturing the DRG explants for nerve tissue growth.
2015, 4(3):53-61. DOI: 10.12146/j.issn.2095-3135.201503006
Abstract:Large-field high-resolution electron tomography enables visualizing detailed mechanisms under global structure. As field enlarges, the distortions of reconstruction and processing time become more critical. TxBR has proposed a curvilinear projection model, which can dramatically improve the quality of reconstruction. But its computation is more complex and time-consuming. Furthermore, previous parallel strategies are not suitable for curvilinear projection model. In this work, a block iterative parallel algorithm using curvilinear projection model on GPU platform was proposed. By studying the locality of curvilinear projection model, we proposed a vertical data decomposition method. We also adopt a page-based data transfer scheme to reduce the processing time. Experimental results show that our method can yield speedups of approximate 40 times.
2015, 4(3):62-68. DOI: 10.12146/j.issn.2095-3135.201503007
Abstract:In modern lung cancer radiotherapy, it is important to have a precise knowledge of the real-time lung tumor position during the treatment delivery. For a real-time 3D lung imaging algorithm from a single X-ray projection image, the inaccuracies contributed by the image registration process affects much on the PCA modelling and construction process. We utilize 3 deformable image registration algorithms: Optical Flow method, Demons method and Levelset method to evaluate the effect. By making quantitative analysis and qualitative analysis, we get the conclusion: Optical Flow method works much better in registration and PCA modelling.
2015, 4(3):69-78. DOI: 10.12146/j.issn.2095-3135.201503008
Abstract:Due to its characteristics of shortness and sparseness, short text, as the main body of microblog and other social media, cannot be accurately classified by the traditional text classification methods. To solve this problem, a method of short text classification based on association rules of lexical items was proposed in this paper. Firstly, the training set based on the strong association rules was mined, and then the strong association rules was added to the features of short text so as to increase the feature density of short text, thereby to increase the accuracy of results of short text classification. Comparative experiments show that this method, to some extent, reduces the impact of sparseness of short text on the classification results, and it improves the classification accuracy, recall values and F1 values.
2015, 4(3):79-85. DOI: 10.12146/j.issn.2095-3135.201503009
Abstract:Emitting plane wave makes ultrasonic imaging enough fast so that it could detect variable blood signal in body, hence it becomes one of the most popular research interest. A new algorithm, multi-angle plane wave coherent compound imaging (MPWCCI) was realized to suppress side-lobe signal, improving the quality of ultrasonic image. Trading off frame rate and signal-noise-ratio (SNR), it could be used to image blood Power Doppler (PD). The contrast of B mode image could be up to 40 dB, and the frame rate to 1000Hz, using more than ten plane waves to compound. Test was accomplished in the slow-flow blood phantom, it shows that clutter signal could be eliminated and blood signal could be extracted effectively, and finally an image depicting hemodynamics was obtained. Result verifies that MPWCCI-PD has a fine sensitivity to slow flow. Furthermore, the effect of the ensemble size on image quality and temporal resolution was discussed. Calculating blood PDs in varying ensemble size data reveals that its frame rate exceeds that of conventional PD imaging, up to tens of Hertz, and the shorter the ensemble images are, the higher the temporal resolution and the better image, and vice versa. Higher temporal resolution is conducive to detecting fast blood flow and better sensitivity is good for the detection of small vessels. MPWCCI-PD may be helpful to imaging cases caused by angiocardiopathy, or brain small vessels.
2015, 4(3):86-92. DOI: 10.12146/j.issn.2095-3135.201503010
Abstract:In this paper, a low-cost, rapid, automated centrifugal microfluidic chip for biochemical analysis was presented. The chip integrates sample pre-processing and multi-biochemical items assay. Through multi-level microfluidic channels and micro-siphon valves, the chip combines the pre-treatment of samples, sample transportation and the reaction processes between sample and biochemical reagent. The results are obtained by colorimetric detection. It is shown that the reproducibility of cuvette pathlength for chip is from 0.08% to 0.52%. The coefficient of variation (CV) of sample, diluents metering and mixing for chip by the CV of blood glucose results is 1.4%. The CV of day-to-day and within-run precision for 15 biochemical items are less than 3.5%. Therefore, it is concluded that the centrifugal microfluidic chip for biochemical analysis can satisfy the clinical testing requirements.