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Improvement of learning and memory abilities and motor function in rats with cerebral infarction by intracerebral transplantation of neuron-like cells derived from bone marrow stromal cells 被引量:4
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作者 Ying Wang Yubin Deng +2 位作者 Ye Wang Yan Li Zhenzhen Hu 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第1期1-5,共5页
BACKGROUND: Transplantation of fetal cell suspension or blocks of fetal tissue can ameliorate the nerve function after the injury or disease in the central nervous system, and it has been used to treat neurodegenerat... BACKGROUND: Transplantation of fetal cell suspension or blocks of fetal tissue can ameliorate the nerve function after the injury or disease in the central nervous system, and it has been used to treat neurodegenerative disorders induced by Parkinson disease. OBJECTIVE: To observe the effects of the transplantation of neuron-like cells derived from bone marrow stromal cells (rMSCs) into the brain in restoring the dysfunctions of muscle strength and balance as well as learning and memory in rat models of cerebral infarction. DESIGN : A randomized controlled experiment.SETTING : Department of Pathophysiology, Zhongshan Medical College of Sun Yat-sen University.MATERIALS : Twenty-four male SD rats (3-4 weeks of age, weighing 200-220 g) were used in this study (Certification number:2001A027). METHODS: The experiments were carried out in Zhongshan Medical College of Sun Yat-sen University between December 2003 and December 2004. ① Twenty-four male SD rats randomized into three groups with 8 rats in each: experimental group, control group and sham-operated group. Rats in the experiment al group and control group were induced into models of middle cerebral artery occlusion (MCAO). After in vitro cultured, purified and identified with digestion, the Fischer344 rMSCs were induced to differentiate by tanshinone IIA, which was locally injected into the striate cortex (18 area) of rats in the experimental group, and the rats in the control group were injected by L-DMEM basic culture media (without serum) of the same volume to the corresponding brain area. In the sham-operated group, only muscle and vessel of neck were separated. ② At 2 and 8 weeks after the transplantation, the rats were given the screen test, prehensile-traction test, balance beam test and Morris water-maze test. ③ The survival and distribution of the induced cells in corresponding brain area were observed with Nissl stained with toluidine blue and hematoxylin and eosin (HE) staining in the groups.MAIN OUTCOME MEASURES : ① Results of the behavioral tests (time of the Morris water-maze test screen test, prehensile-traction test, balance beam test); ② Survival and distribution of the induced cells.RESULTS: All the 24 rats were involved in the analysis of results. ① Two weeks after transplantation, rats with neuron-like cells grafts in the experimental group had significant improvement on their general muscle strength than those in the control group [screen test: (9.4±1.7), (4.7±1.0) s, P 〈 0.01]; forelimb muscle strength [prehensile-traction test: (7.6±1.4), (5.2±1.2) s, P 〈 0.01], ability to keep balance [balance beam test: (7.9±0.74), (6.1±0.91) s, P 〈 0.01] and abilities of learning and memory [latency to find the platform: (35.8±5.9), (117.5±11.6) s, P 〈 0.01; distance: (623.1±43.4), (1 902.3±98.6) cm, P 〈 0.01] as compared with those in the control group. The functional performances in the experimental group at 8 weeks were better than those at two weeks, which were still obviously different from those in the sham-operated group (P 〈 0.05). ② The HE and Nissl stained brain tissue section showed that there was nerve cell proliferation at the infarcted cortex in the experiment group, the density was higher than that in the control group, plenty of aggregative or scattered cells could be observed at the site where needle was inserted for transplantation, the cells migrated directively towards the area around them, the cerebral vascular walls were wrapped by plenty of cells; In the control group, most of the cortices were destroyed, karyopyknosis and necrosis of neurons were observed, normal nervous tissue structure disappeared induced by edema, only some nerve fibers and glial cells remained.CONCLUSION: The rMSCs transplantation can obviously enhance the motor function and the abilities of learning and memory in rat models of cerebral infarction. 展开更多
关键词 Improvement of learning and memory abilities and motor function in rats with cerebral infarction by intracerebral transplantation of neuron-like cells derived from bone marrow stromal cells bone
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Set Programming Method and Performance Improvement of Phase Change Random Access Memory Arrays
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作者 范茜 陈后鹏 +6 位作者 王倩 王月青 吕士龙 刘燕 宋志棠 冯高明 刘波 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第6期184-187,共4页
A novel slow-down set waveform is proposed to improve the set performance and a 1 kb phase change random access memory chip fabricated with a 13nm CMOS technology is implemented to investigate the set performance by d... A novel slow-down set waveform is proposed to improve the set performance and a 1 kb phase change random access memory chip fabricated with a 13nm CMOS technology is implemented to investigate the set performance by different set programming strategies based on this new set pulse. The amplitude difference (I1 - I2) of the set pulse is proved to be a crucial parameter for set programming. We observe and analyze the cell characteristics with different I1 - I2 by means of thermal simulations and high-resolution transmission electron microscopy, which reveal that an incomplete set programming will occur when the proposed slow-down pulse is set with an improperly high I1 - I2. This will lead to an amorphous residue in the active region. We also discuss the programming method to avoid the set performance degradations. 展开更多
关键词 PCRAM Set Programming Method and Performance Improvement of Phase Change Random Access memory Arrays
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Improved Operation Characteristics for Nonvolatile Charge-Trapping Memory Capacitors with High-κ Dielectrics and SiGe Epitaxial Substrates
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作者 Zhao-Zhao Hou Gui-Lei Wang +4 位作者 Jin-Juan Xiang Jia-Xin Yao Zhen-Hua Wu Qing-Zhu Zhang Hua-Xiang Yin 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第9期95-99,共5页
A novel high-κ~ A1203/HfO2/AI203 nanolaminate charge trapping memory capacitor structure based on SiGe substrates with low interface densities is successfully fabricated and investigated. The memory capacitor exhibit... A novel high-κ~ A1203/HfO2/AI203 nanolaminate charge trapping memory capacitor structure based on SiGe substrates with low interface densities is successfully fabricated and investigated. The memory capacitor exhibits excellent program-erasable characteristics. A large memory window of ~4 V, a small leakage current density of ~2 ×10-6 Acre-2 at a gate voltage of 7V, a high charge trapping density of 1.42 × 1013 cm-2 at a working vo]tage of 4-10 V and good retention characteristics are observed. Furthermore, the programming (△ VFB = 2.8 V at 10 V for 10μs) and erasing speeds (△VFB =-1.7 V at -10 V for 10μs) of the fabricated capacitor based on SiGe substrates are significantly improved as compared with counterparts reported earlier. It is concluded that the high-κ Al2O3/HfO2/Al2O3 nanolaminate charge trapping capacitor structure based on SiGe substrates is a promising candidate for future nano-scaled nonvolatile flash memory applications. 展开更多
关键词 Dielectrics and SiGe Epitaxial Substrates Improved Operation Characteristics for Nonvolatile Charge-Trapping memory Capacitors with High
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Improvement of Operation Characteristics for MONOS Charge Trapping Flash Memory with SiGe Buried Channel
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作者 Zhao-Zhao Hou Gui-Lei Wang +2 位作者 Jia-Xin Yao Qing-Zhu Zhang Hua-Xiang Yin 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第5期110-114,共5页
We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure(named as MONOS), utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent pr... We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure(named as MONOS), utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent programerasable characteristics attributed to the fact that more carriers are generated by the smaller bandgap of Si Ge during program/erase operations. A flat-band voltage shift 2.8 V can be obtained by programming at +11 V for 100 us. Meanwhile, the memory device exhibits a large memory window of ~7.17 V under ±12 V sweeping voltage, and a negligible charge loss of 18% after 104 s' retention. In addition, the leakage current density is lower than 2.52 × 10^(-7) A·cm^(-2) below a gate breakdown voltage of 12.5 V. Investigation of leakage current-voltage indicates that the Schottky emission is the predominant conduction mechanisms for leakage current. These desirable characteristics are ascribed to the higher trap density of the Si_3N_4 charge trapping layer and the better quality of the interface between the SiO_2 tunneling layer and the Si Ge buried channel. Therefore, the application of the Si Ge buried channel is very promising to construct 3 D charge trapping NAND flash devices with improved operation characteristics. 展开更多
关键词 FB Improvement of Operation Characteristics for MONOS Charge Trapping Flash memory with SiGe Buried Channel
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