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991.
基于不同局部模型的联合滤波算法研究 总被引:3,自引:0,他引:3
从组合导航系统研究的角度出发,提出了一种基于不同局部模型的联合滤波算法,并对INS/GPS/Doppler组合导航系统进行了仿真。结果表明:该算法不要求局部模型一致,增强了系统的通用性,提高了运算速度。 相似文献
992.
Changyoun Kim Eun-Deok Cho Hyung-Koo Kim Sungyong You He-Jin Lee Daehee Hwang Seung-Jae Lee 《Experimental & molecular medicine》2014,46(4):e91
Chronic neuroinflammation is an integral pathological feature of major neurodegenerative diseases. The recruitment of microglia to affected brain regions and the activation of these cells are the major events leading to disease-associated neuroinflammation. In a previous study, we showed that neuron-released α-synuclein can activate microglia through activating the Toll-like receptor 2 (TLR2) pathway, resulting in proinflammatory responses. However, it is not clear whether other signaling pathways are involved in the migration and activation of microglia in response to neuron-released α-synuclein. In the current study, we demonstrated that TLR2 activation is not sufficient for all of the changes manifested by microglia in response to neuron-released α-synuclein. Specifically, the migration of and morphological changes in microglia, triggered by neuron-released α-synuclein, did not require the activation of TLR2, whereas increased proliferation and production of cytokines were strictly under the control of TLR2. Construction of a hypothetical signaling network using computational tools and experimental validation with various peptide inhibitors showed that β1-integrin was necessary for both the morphological changes and the migration. However, neither proliferation nor cytokine production by microglia was dependent on the activation of β1-integrin. These results suggest that β1-integrin signaling is specifically responsible for the recruitment of microglia to the disease-affected brain regions, where neurons most likely release relatively high levels of α-synuclein. 相似文献
993.
G. H. Sheng Y. Huo Y. T. Ye Z. You H. L. Zhu 《Russian Journal of Coordination Chemistry》2014,40(9):664-670
Two new oxovanadium(V) complexes, [VOL1(SHA)] (I) and [VOL2(BHA)] (II), were prepared by the reaction of [VO(Acac)2] (Acac = acetylacetonate) with N′-(2-hydroxybenzylidene)isonicotinohydrazide (H2L1) and salicylhydroxamic acid (HSHA) and 4-chloro-N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (H2L2) and benzohydroxamic acid (HBHA), respectively, in methanol. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared spectra and single crystal X-ray diffraction (CIF file CCDC nos. 978238 (I) and 978392 (II)). The V atoms are in octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied. 相似文献
994.
Gold‐Catalyzed C(sp3)H/C(sp)H Coupling/Cyclization/Oxidative Alkynylation Sequence: A Powerful Strategy for the Synthesis of 3‐Alkynyl Polysubstituted Furans 下载免费PDF全文
Yuanhong Ma Shuai Zhang Shiping Yang Dr. Feijie Song Prof. Dr. Jingsong You 《Angewandte Chemie (International ed. in English)》2014,53(30):7870-7874
In sharp contrast to the gold‐catalyzed reactions of alkynes/allenes with nucleophiles, gold‐catalyzed oxidative cross‐couplings and especially C? H/C? H cross‐coupling have been under represented. By taking advantage of the unique redox property and carbophilic π acidity of gold, this work realizes the first gold‐catalyzed direct C(sp3)? H alkynylation of 1,3‐dicarbonyl compounds with terminal alkynes under mild reaction conditions, with subsequent cyclization and in situ oxidative alkynylation. A variety of terminal alkynes including aryl, heteroaryl, alkenyl, alkynyl, alkyl, and cyclopropyl alkynes all successfully participate in the domino reaction. The protocol offers a simple and region‐defined approach to 3‐alkynyl polysubstituted furans. 相似文献
995.
Direct Asymmetric Dearomatization of Pyridines and Pyrazines by Iridium‐Catalyzed Allylic Amination Reactions 下载免费PDF全文
Ze‐Peng Yang Dr. Qing‐Feng Wu Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2014,53(27):6986-6989
The first iridium‐catalyzed intramolecular asymmetric allylic dearomatization reaction of pyridines and pyrazines has been realized. 2,3‐Dihydroindolizine and 6,7‐dihydropyrrolo[1,2‐a]pyrazine derivatives were obtained with excellent yields and enantioselectivity. This methodology features dearomatization by direct N‐allylic alkylation of pyridines or pyrazines under mild reaction conditions. 相似文献
996.
Tao Lv Xian‐En Zhao Shuyun Zhu Fei Qu Cuihua Song Jinmao You Yourui Suo 《Journal of separation science》2014,37(19):2757-2763
A novel hyphenated method based on ultrasound‐assisted dispersive liquid–liquid microextraction coupled to precolumn derivatization has been established for the simultaneous determination of bisphenol A, 4‐octylphenol, and 4‐nonylphenol by high‐performance liquid chromatography with fluorescence detection. Different parameters that influence microextraction and derivatization have been optimized. The quantitative linear range of analytes is 5.0–400.0 ng/L, and the correlation coefficients are more than 0.9998. Limits of detection for soft drinks and dairy products have been obtained in the range of 0.5–1.2 ng/kg and 0.01–0.04 μg/kg, respectively. Relative standard deviations of intra‐ and inter‐day precision for retention time and peak area are in the range of 0.47–2.31 and 2.76–8.79%, respectively. Accuracy is satisfactory in the range of 81.5–118.7%. Relative standard deviations of repeatability are in the range of 0.35–1.43 and 2.36–4.75% for retention time and peak area, respectively. Enrichment factors for bisphenol A, 4‐octylphenol, and 4‐nonylphenol are 170.5, 240.3, and 283.2, respectively. The results of recovery and matrix effect are in the range of 82.7–114.9 and 92.0–109.0%, respectively. The proposed method has been applied to the determination of bisphenol A, 4‐octylphenol, and 4‐nonylphenol in soft drinks and dairy products with much higher sensitivity than many other methods. 相似文献
997.
Effervescence‐assisted dispersive liquid–liquid microextraction using a solid effervescent agent as a novel dispersion technique for the analysis of fungicides in apple juice 下载免费PDF全文
Wenqing Jiang Xiaochu Chen Fengmao Liu Xiangwei You Jiaying Xue 《Journal of separation science》2014,37(21):3157-3163
A novel effervescence‐assisted dispersive liquid–liquid microextraction method has been developed for the determination of four fungicides in apple juice samples. In this method, a solid effervescent agent is added into samples to assist the dispersion of extraction solvent. The effervescent agent is environmentally friendly and only produces an increase in the ionic strength and a negligible variation in the pH value of the aqueous sample, which does not interfere with the extraction of the analytes. The parameters affecting the extraction efficiency were investigated including the composition of effervescent agent, effervescent agent amount, formulation of effervescent agent, adding mode of effervescent agent, type and volume of extraction solvent, and pH. Under optimized conditions, the method showed a good linearity within the range of 0.05–2 mg/L for pyrimethanil, fludioxonil, and cyprodinil, and 0.1–4 mg/L for kresoxim‐methyl, with the correlation coefficients >0.998. The limits of detection for the method ranged between 0.005 and 0.01 mg/L. The recoveries of the target fungicides in apple juice samples were in the range of 72.4–110.8% with the relative standard deviations ranging from 1.2 to 6.8%. 相似文献
998.
Potential of cross-priming amplification and DNA-based lateral-flow strip biosensor for rapid on-site GMO screening 总被引:2,自引:0,他引:2
Xin Huang Congcong Zhai Qimin You Hongjun Chen 《Analytical and bioanalytical chemistry》2014,406(17):4243-4249
The requirement to monitor the presence of genetically modified organisms (GMO) in a variety of marked products has generated an increasing demand for reliable, rapid, and time and cost-effective analytical methods. Here we report an on-site method for rapid detection of cauliflower mosaic virus promoter (CaMV 35S), a common element present in most GMO, using cross-priming amplification (CPA) technology. Detection was achieved using a DNA-based contamination-proof strip biosensor. The limit of detection was 30 copies for the pBI121 plasmid containing the CaMV 35S gene. The certified reference sample of GM maize line MON810 was detectable even at the low relative mass concentration of 0.05 %. The developed CPA method had high specificity for the CaMV 35S gene, as compared with other GM lines not containing this gene and non-GM products. The method was further validated using nine real-world samples, and the results were confirmed by real-time PCR analysis. Because of its simplicity, rapidity, and high sensitivity, this method of detecting the CaMV 35S gene has great commercial prospects for rapid GMO screening of high-consumption food and agriculture products. 相似文献
999.
Synthesis and Characterization of Two‐Photon Chromophores Based on a Tetrasubstituted Tetraethynylethylene Scaffold 下载免费PDF全文
Prof. Tzu‐Chau Lin Yi‐You Liu May‐Hui Li Che‐Yu Liu Sheng‐Yang Tseng Yu‐Ting Wang Ya‐Hsin Tseng Hui‐Hsin Chu Prof. Chih‐Wei Luo 《化学:亚洲杂志》2014,9(6):1601-1610
A new series of model dye molecules composed of three multibranched analogues based on the tetrasubstituted tetraethynylethylene structural motif have been synthesized and experimentally shown to possess strong and widely dispersed two‐photon absorption (2PA) in the near‐IR region. It was found that the spectral position of the major 2PA band could be tuned by the electronic nature of the selected substitution units. The studied model fluorophores also exhibited fairly low photodegradation of their fluorescence intensity even under prolonged UV‐light irradiation, which is beneficial for the development of fluorescence probes that are needed for long‐term light exposure. Furthermore, representative chromophores were selected to demonstrate the power‐control properties within the femtosecond and nanosecond time domains. 相似文献
1000.
De‐Yun Ma Jing Zheng Jie‐Qiong Cao Xu‐Min Lin You‐Biao Ling 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(8):801-804
A novel three‐dimensional ZnII complex, poly[aqua(μ4‐5‐carboxylato‐1‐carboxylatomethyl‐2‐oxidopyridinium)zinc(II)], [Zn(C8H5NO4)(H2O)]n, has been prepared by hydrothermal assembly of Zn(CH3COO)2·2H2O and 5‐carboxy‐1‐(carboxymethyl)pyridin‐1‐ium‐2‐olate (H2ccop). The ccop2− anions bridge the ZnII cations in a head‐to‐tail fashion via monodentate aromatic carboxylate and phenolate O atoms to form an extended zigzag chain which runs parallel to the [011] direction. One O atom of the aliphatic carboxylate group of the ccop2− ligand coordinates to the ZnII atom of a neighbouring chain thereby producing undulating layers which lie parallel to the (01) plane. A similar parallel undulating planar structure can be obtained if a path involving the other O atom of the aliphatic carboxylate group is considered. Thus, the aliphatic carboxylate group acts in a bridging bidentate mode to give extended –Zn–O–C–O–Zn– sequences running parallel to [001] which link the layers into an overall three‐dimensional framework. The three‐dimensional framework can be simplified as a 4‐connected sra topology with a Schläfli symbol of 42.63.8 if all the ZnII centres and ccop2− anions are regarded as tetrahedral 4‐connected nodes. The three‐dimensional luminescence spectrum was measured at room temperature with excitation and emission wavelengths of 344–354 and 360–630 nm, respectively, at intervals of 0.15 and 2 nm, respectively. 相似文献