2019, 8(6):1-10. DOI: 10.12146/j.issn.2095-3135.20190423001
Abstract:In this paper, four design methods of gearbox are introduced, and their timing analysis is carried out. By comparing the number of cells (area), power consumption, speed and stability, a gearbox based on roundrobin saving mode is selected and applied to 100GE physical coding sublayer circuit. It can take out the output value within a certain range, which overcomes the influence of phase difference between input and output clocks and greatly improves the speed and stability of the circuit. After structure optimization and pipeline design, the gearbox can work stability at the clock frequency of over 700 MHz and meet the design requirement. The physical coding sublayer circuit which including the gearbox has been taped out in 0.18 μm complementary metal oxide semiconductor technology and measured results show that it can work properly at speed of 100 Gb/s.
2019, 8(6):11-20. DOI: 10.12146/j.issn.2095-3135.20190618001
Abstract:Wave-CAIPI is a novel 3D imaging method with multiple-channel coils and corkscrew trajectories in k-space to speed up magnetic resonance imaging acquisition. However, the 3D data acquisitions of Wave-CAIPI are usually time consuming. In order to accelerate the reconstruction procedure, we realized a Wave-CAIPI reconstruction method using a modified GPU-based conjugate gradient algorithm to reduce time cost of the image reconstructions. The experiments of phantom and in vivo human brain show that the proposed GPU-based Wave- CAIPI reconstruction can achieve similar imaging results with less time cost, comparing to the conventional CPU-based Wave-CAIPI reconstruction.
2019, 8(6):21-30. DOI: 10.12146/j.issn.2095-3135.20191016001
Abstract:The intelligent parking lock (IPL) can monitor parking spaces with its built-in magnetic sensor, and the parking information can be used to realize automatic payment, parking reservation, parking sharing, and so on. However, in the operation of locking and unlocking, the IPL generates magnetic interference signals, which will result in false detections of traditional parking detection algorithms. To solve this problem, a robust parking detection algorithm was investigated. The vehicle magnetic signal is modeled as a variance sequence, and a filtering method of interference signal is applied to remove noisy signal. The parking detection algorithm is implemented based on the state machine. In the experiment, fifty IPLs were deployed in the parking spaces. The results show that the proposed algorithm is more robust and can improve the vehicle detection accuracy.
2019, 8(6):31-38. DOI: 10.12146/j.issn.2095-3135.20190814001
Abstract:Direct repeat sequences widely exist in eukaryotic and prokaryotic genomes, which involves in human diseases like hereditary neuromuscular neurodegenerative disease. Thus, it is of great importance to quantify the frequency of the deletion of direct repeat sequences. Using the high-throughput microscopy imaging and analysis technology, we designed a three-color fluorescent-based reporter system to quantify the frequency of the deletion of direct repeat sequences. We found that the frequency of the deletion of direct repeat sequences decreased in the recA mutant in P. aeruginosa, and the absence of RadA and UvrD increased the occurrence frequency of the deletion of direct repeat sequences, but the frequency of the deletion of direct repeat sequences was independent of the following factors: fitness or promoter variants etc. This work can be helpful to the further understanding of the deletion of direct repeat sequences, which also provide a novel method to quantify the deletion of direct repeat sequences.
2019, 8(6):39-47. DOI: 10.12146/j.issn.2095-3135.20190729005
Abstract:Ischemic stroke is an acute cerebrovascular disease. Currently, it is treated mainly by timely thrombolysis or mechanical thrombectomy to achieve vascular recanalization, but this process causes serious reperfusion injury to cerebrovasculature, damages the structure and function of the blood-brain barrier (BBB), and increases the risk of cerebral hemorrhage. Studies have shown that the Wnt/β-catenin signaling pathway plays a critical role in regulating the function of BBB, but whether the R-spondin, an agonistic protein of the Wnt/β-catenin signaling pathway, plays a role in regulation of BBB and cerebral injury is unclear. In this study, using mouse recombinant R-spondin-1 protein prepared in vitro, we determined the activation of Wnt/β-catenin signaling pathway induced by combined treatment of the R-spondin-1 protein and Wnt3a protein in mouse primary cerebrovascular endothelial cells, and found that R-spondin1 significantly changed the expression levels of BBB function related genes Cldn3 and Plvap. In a mouse cerebral ischemia/reperfusion model, intravenous injection of recombinant R-spondin-1 protein was inclined to reduce the cerebral infarction and increase mouse survival but did not reach statistical significance compared to phosphate buffer solution controls. Our study reported the molecular mechanisms of BBB function regulation by R-spondin protein, and preliminarily identified its therapeutic effect on cerebral injury following stroke and potential for clinical use.
2019, 8(6):48-64. DOI: 10.12146/j.issn.2095-3135.20190805001
Abstract:Memristor, as the fourth fundamental circuit element (resistor, capacitor, inductor and memristor), possessing non-volatile characteristics, is expected to be one kind of the basic devices of brain-like computing circuits. Compared with traditional complementary metal oxide semiconductor (CMOS) devices, its switch performance and size need to be further improved. Ge2Sb2－xBixTe5(x＝0, 0.2) material can undergo reversible phase change under thermal effect, and can also be crystallized under femtosecond laser treatment. To provide a basis for high performance and high integration of brain-like circuits, this work proposes the one-dimension nanowire-based memristor. Firstly, the Ge2Sb2－xBixTe5(x＝0, 0.2) material was analyzed by X-ray diffraction analysis, Raman scattering, scanning electron microscope, atomic force microscope and Hall effect test. The results show that Bi doping could reduce the crystalline temperature, increase the resistivity and the phase transition temperature, while the lattice structure is unchanged. Secondly, the 500 nm width Ge2Sb2－xBixTe5 nanobelt was obtained via ourself-made femtosecond laser nano fabrication system. Finally, a resistance switch ratio up to 7 400 was observed in a Ag/Ge2Sb2－xBixTe5/Ag memristor, with a stable cycle of 60 cycles, maintaining 3 250 s.
2019, 8(6):65-74. DOI: 10.12146/j.issn.2095-3135.20190710001
Abstract:In this paper, the degradation of unsym-dimethylhydrazine wastewater with low atmospheric plasma generated by floating-electrode dielectric barrier discharge was studied, and the treatment conditions were optimized. Firstly, the degradation effects of low atmospheric plasma equipment, xenon lamp and ultraviolet lamp were compared. Secondly, the influence of discharge gap, initial solution pH, treatment time, addition of sodium hydroxide solution were also studied. Meanwhile, the effect of low temperature plasma on the pH value of unsym-dimethylhydrazine wastewater was also investigated. Without the addition of other reagents, the degradation of unsym-dimethylhydrazine with low temperature plasma was better than xenon lamp and ultraviolet lamp. When the discharge gap was shortened from 4 mm to 2 mm, the degradation rate of unsymdimethylhydrazine was increased by 47.2%. With the increase of plasma treatment time, the content of unsymdimethylhydrazine decreased, and 82.1% of unsym-dimethylhydrazine could be degraded after treatment for 20 minutes. The pH value of the unsym-dimethylhydrazine wastewater decreased from 10 to 6.9 after 10 min of treatment. While, the degradation rate of unsym-dimethylhydrazine increased by 65.9% with the initial pH value increased from 2 to 10. After 10 min of low temperature plasma treatment, sodium hydroxide solution was added to the wastewater with a concentration of 1 mg/mL, and the degradation rate of unsym-dimethylhydrazine reached 95% after another 10 min treatment.