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61.
Ascorbic acid (AA) induced differentiation of neural stem cells (NSCs) into dopaminergic (DAergic) neurons is reported.NSCs derived from rat mesencephalon were maintained and expanded in a defined medium containing mitogens of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF).Compared with the control, ascorbic acid treatment led to more DAergic neuronal differentiation as indicated by the expression of tyrosine hydroxylase (TH) and dopamine transporter (DAT), which are specific markers of dopamine neurons.AA induction also enhanced expression of Nurr1 and Shh.PD98059, an inhibitor of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway, could block AA-induced Nurr1, TH and DAT mRNA expression.The results might suggest a new strategy to provide enough dopaminergic cells for the therapy of Parkinson's disease (PD), and Nurr1 and ERK signaling pathway might participate in the AA-induced DAergic differentiation.  相似文献   
62.
朱晓晶  张锦盛  段楠 《科技资讯》2014,12(18):15-16
本文从昆明长水国际机场鸟击防治工作现状出发,提出人工管理、纸质台账存在的问题,由此引出构建鸟击防治管理信息平台的必要性。在需求及技术框架层面上,对系统功能进行了简洁明了的说明。  相似文献   
63.
Clinical observations indicate that DanHong Injection (DHI) can increase blood flow and reduce various syndromes in patients with cardiovascular disease. How- ever, it still needs to define the function of DHI and the involved mechanisms in details, such as the protective effect on the development of primary abdominal aortic aneurysms (AAAs). In this study, we determined whether DHI is able to inhibit AAA in apoE knockout (apoE-/-) mice. Thirty apoE-/- male mice on high-fat diet (0.5 % cholesterol, 21% fat) were randomly divided into two groups and received i.p. injection of saline (100 μL/day) and DHI (100 μL/day), respectively, for 16 weeks. At the end of experiment, we determined the development of atherosclerosis in en face aorta and aneurysms,pathological morphology of arterial wall, and serum lipid levels. We also determined the expression of monocyte chemoattractant protein-1 (MCP-1), MMP-2, and MMP-9 mRNA in aortic wall using real-time RT-PCR. Our results indicated that high-fat diet induced the development of AAAs in apoE-/- mice, but the induction was totally blocked by DHI (P 〈 0.01). The result of staining of abdominal aortic cross sections showed that DHI main- tained the collagen content in arterial wall, thereby pre- venting the animals from the development of AAA. Although DHI had little effect on serum total- and LDL- cholesterol levels, it reduced the expression of MCP-1, MMP-2, and MMP-9 mRNA in aortic wall (P 〈 0.01). Taken together, our study suggests that DHI can inhibit the high-fat diet-induced AAA formation. The inhibitory effects may be related to the maintenance of the collagen content and inhibition of expression of AAA-related genes. Our study may suggest a new application of DHI in clinics.  相似文献   
64.
概述了氨酸法料床直接反应工艺的特点,并提出其后续优化措施,即将浓硫酸的稀释热用于液氨的汽化或将部分原料加热熔融生成料浆,采用两段湿法洗涤的手段对造粒尾气、干燥尾气和冷却尾气进行综合治理。采用上述改进措施后,能进一步提高热量的利用水平,明显提高了尾气的净化效果,实现洗涤液零排放。  相似文献   
65.
提出了一种基于生成对抗网络的无载体信息隐藏方法.发送方用伪装图像和Improved Wasserstein GAN生成一张与秘密图像相同的图像,发送方发送伪装图像,接收方收到伪装图像后用生成器生成和秘密图像视觉上相同的图像.与现有的信息隐藏方法相比,该方法不需要修改载体,能够有效地抵抗隐写分析工具的检测,能够达到秘密信息安全传输的目的.  相似文献   
66.
An ion flux dropout near the dipolarization front (DF) at around XGSM =- 11 RE in the Earth' s plasma sheet was observed by Time History of Events and Macroscale Interaction during substorms (THEMIS) on March 31, 2009. The ion differential energy fluxes at energies from 450 eV to 150 keV measured by the ESA and SST instruments from THC began to decrease about 2 s before the detection of the DF and reached a local minimum 6 s later. Then, the ion fluxes gradually increased to form a dropout around the DF. The spatial extent of the dropout was about 4,000 km. For energies above 20 keV, the ion fluxes after the dropout are greater than those before it, contrary to the fluxes at energies below 20 keV. The associated ion density variation indicates that the ion flux dropout coincides with the ion density dropout. Taking advantage of multipoint observations, THD, THC, and THE detected the same DF consecutively. Only THC detected an obvious ion flux dropout; THD observed an indistinct one about 2 s before THC; no high-energy (E 〉 30 keV) ion flux dropout was observed by THE. Our study suggests that the ion flux dropout may evolve with the earthward-propagating DF, and its properties can depend on locations relative to the DF.  相似文献   
67.
For the improvement of accuracy and better fault-tolerant performance, a global position system (GPS)/vision navigation (VISNAV) integrated relative navigation and attitude determination approach is presented for ultra-close spacecraft formation flying. Onboard GPS and VISNAV system are adopted and a federal Kalman filter architecture is used for the total navigation system design. Simulation results indicate that the integrated system can provide a total improvement of relative navigation and attitude estimation performance in accuracy and fault-tolerance.  相似文献   
68.
通过浸渍法制备了Mo/TiO2,Mn-Mo/TiO2和Mo-Mn/TiO2三种催化剂,采用X射线衍射(XRD)、比表面积测定(BET)、拉曼光谱(LRS)、原位红外(in situ FT-IR)、扫描电镜(SEM)等技术进行相关的微观表征分析.在模拟氨气选择性催化还原NO的反应条件下(NH3-SCR)对催化剂的脱硝反应...  相似文献   
69.
超声波浸渍法制备MnOx/TiO2催化剂低温选择性催化还原NO   总被引:1,自引:0,他引:1  
采用超声波浸渍法、传统浸渍法和溶胶凝胶法制备了一系列的MnOx/TiO2催化剂,采用X射线衍射(XRD)、比表面积测定(BET)、原位红外(in situ FT-IR)、高分辨率扫描电镜(HRTEM)程序升温还原(TPR)等技术进行表征,同时在模拟氨气选择性催化还原NO的反应条件下( NH3-SCR)对催化剂的低温反应...  相似文献   
70.
干线协调交叉口多相公交信号优先控制策略   总被引:1,自引:0,他引:1  
针对干线协调交叉口多个相位有公交车到达的情况,为降低公交车延误,建立了以不破坏协调绿波带为前提的多相位公交优先控制策略.在该策略中,提出了“就近原则”以解决多个相位的公交优先申请冲突,对公交优先级别进行排序,并建立了多相位公交优先控制流程;考虑最高优先级别公交车的不同相位属性,采用绿灯延长和绿灯提前起亮两种优先方式,分...  相似文献   
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