H<SUB>∞</SUB> Filtering for Descriptor Systems

Yue-Peng Chen,Zu-De Zhou,Chun-Nian Zeng,Qing-Ling Zhang 대한전기학회 2006 International Journal of Control, Automation, and Vol.4 No.6

The paper is concerned with H∞ filtering for descriptor systems. A necessary and sufficient condition is established in terms of linear matrix inequalities (LMIs) for the existence of normal filters such that the error systems are admissible and the transfer function from the disturbance to the filtering error output satisfies a prescribed H∞-norm bound constraint. When these LMIs are feasible, an explicit parameterization expression of all desired normal filter is given. All these results are yielded without decomposing the original descriptor systems, which makes the filter design procedure simple and direct. Finally, a numerical example is derived to demonstrate the applicability of the proposed approach.

Dexmedetomidine promotes the progression of hepatocellular carcinoma through hepatic stellate cell activation

Chen Peng,Luo Xiaojun,Dai Guanqi,Jiang Yuchuan,Luo Yue,Peng Shuang,Wang Hao,Xie Penghui,Qu Chen,Lin Wenyu,Hong Jian,Ning Xue,Li Aimin 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Dexmedetomidine (DEX) is an anesthetic that is widely used in the clinic, and it has been reported to exhibit paradoxical effects in the progression of multiple solid tumors. In this study, we sought to explore the mechanism by which DEX regulates hepatocellular carcinoma (HCC) progression underlying liver fibrosis. We determined the effects of DEX on tumor progression in an orthotopic HCC mouse model of fibrotic liver. A coculture system and a subcutaneous xenograft model involving coimplantation of mouse hepatoma cells (H22) and primary activated hepatic stellate cells (aHSCs) were used to study the effects of DEX on HCC progression. We found that in the preclinical mouse model of liver fibrosis, DEX treatment significantly shortened median survival time and promoted tumor growth, intrahepatic metastasis and pulmonary metastasis. The DEX receptor (ADRA2A) was mainly expressed in aHSCs but was barely detected in HCC cells. DEX dramatically reinforced HCC malignant behaviors in the presence of aHSCs in both the coculture system and the coimplantation mouse model, but DEX alone exerted no significant effects on the malignancy of HCC. Mechanistically, DEX induced IL-6 secretion from aHSCs and promoted HCC progression via STAT3 activation. Our findings provide evidence that the clinical application of DEX may cause undesirable side effects in HCC patients with liver fibrosis.

Feasibility of Free-Breathing, Non-ECG-Gated, Black-Blood Cine Magnetic Resonance Images With Multitasking in Measuring Left Ventricular Function Indices

Peng Pengfei,Yue Xun,Tang Lu,Wu Xi,Deng Qiao,Wu Tao,Cai Lei,Liu Qi,Xu Jian,Huang Xiaoqi,Chen Yucheng,Diao Kaiyue,Sun Jiayu 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.12

Objective: To clinically validate the feasibility and accuracy of cine images acquired through the multitasking method, with no electrocardiogram gating and free-breathing, in measuring left ventricular (LV) function indices by comparing them with those acquired through the balanced steady-state free precession (bSSFP) method, with multiple breath-holds and electrocardiogram gating. Materials and Methods: Forty-three healthy volunteers (female:male, 30:13; mean age, 23.1 ± 2.3 years) and 36 patients requiring an assessment of LV function for various clinical indications (female:male, 22:14; 57.8 ± 11.3 years) were enrolled in this prospective study. Each participant underwent cardiac magnetic resonance imaging (MRI) using the multiple breath-hold bSSFP method and free-breathing multitasking method. LV function parameters were measured for both MRI methods. Image quality was assessed through subjective image quality scores (1 to 5) and calculation of the contrast-to-noise ratio (CNR) between the myocardium and blood pool. Differences between the two MRI methods were analyzed using the Bland–Altman plot, paired t-test, or Wilcoxon signed-rank test, as appropriate. Results: LV ejection fraction (LVEF) was not significantly different between the two MRI methods (P = 0.222 in healthy volunteers and P = 0.343 in patients). LV end-diastolic mass was slightly overestimated with multitasking in both healthy volunteers (multitasking vs. bSSFP, 60.5 ± 10.7 g vs. 58.0 ± 10.4 g, respectively; P < 0.001) and patients (69.4 ± 18.1 g vs. 66.8 ± 18.0 g, respectively; P = 0.003). Acceptable and comparable image quality was achieved for both MRI methods (multitasking vs. bSSFP, 4.5 ± 0.7 vs. 4.6 ± 0.6, respectively; P = 0.203). The CNR between the myocardium and blood pool showed no significant differences between the two MRI methods (18.89 ± 6.65 vs. 18.19 ± 5.83, respectively; P = 0.480). Conclusion: Multitasking-derived cine images obtained without electrocardiogram gating and breath-holding achieved similar image quality and accurate quantification of LVEF in healthy volunteers and patients.

Synthesis and properties of ultrafine YAG powder via low-temperature microwave hydrothermal method

Yue Liu,Jieguang Song,Lin Chen,Huihui Luo,Guojian Lin,Peng Chen,Chenhui Wei,Jingjing Liu 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.4

Yttrium aluminum garnet (YAG) has good optical properties and has been widely used in engineering. The preparation ofconventional YAG powder is costly due to its high synthesis temperature, so lowering the synthesis temperature is the mosteffective way to save cost. The ultrafine oxide composite powder was rapidly synthesized using the microwave hydrothermalmethod at a low temperature. The effect of temperature and its performance. Differential thermal analysis and XRD phaseanalysis showed the mixed solution of Al(NO3)3 and Y(NO3)3 at pH=9 and C(Al3+)=0.42 mol·L−1. SEM, zeta potential, andparticle size analysis revealed that the microwave hydrothermal reaction temperature was 170 oC, and the high-purityultrafine YAG powder was calcined at 928 oC, which was lower than conventional calcination temperature. The synthesizedultrafine spherical YAG powder had a small particle size and a uniform distribution.

Sequencing, Genomic Structure, Chromosomal Mapping and Association Study of the Porcine ADAMTS1 Gene with Litter Size

Yue, K.,Peng, J.,Zheng, R.,Li, J.L.,Chen, J.F.,Li, F.E.,Dai, L.H.,Ding, SH.H.,Guo, W.H.,Xu, N.Y.,Xiong, Y.ZH.,Jiang, S.W. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.7

A disintegrin-like and metalloprotease (reprolysin type) with thrombospondin type 1 motif (ADAMTS1) plays a critical role in follicular rupture and represents a major advance in the proteolytic events that control ovulation. In this study, a 9,026-bp DNA sequence containing the full coding region, all 8 introns and part of the 5'and 3' untranslated region of the porcine ADAMTS1 gene was obtained. Analysis of the ADAMTS1 gene using the porcine radiation hybrid panel indicated that pig ADAMTS1 is closely linkage with microsatellite marker S0215, located on SSC13q49. The open reading frame of its cDNA covered 2,844 bp and encoded 947 amino acids. The coding region of porcine ADAMTS1 as determined by sequence alignments shared 85% and 81% identity with human and mouse cDNAs, respectively. The deduced protein contained 947 amino acids showing 85% sequence similarity both to the human and mouse proteins, respectively. Comparative sequencing of three pig breeds revealed one single nucleotide polymorphism (SNP) within exon 7 of which a G-C substitution at position 6006 changes a codon for arginine into a codon for proline. The substitution was situated within a PvuII recognition site and developed as a PCR-RFLP marker for further use in population variation investigations and association analysis with litter size. Allele frequencies of this SNP were investigated in seven pig breeds/lines. An association analysis in a new Qingping female line suggested that different ADAMTS1 genotypes have significant differences in litter size (p<0.01).

Inner Mechanism of Enhanced Energy Storage Properties and Efficiency for CaTiO3 Modified 0.92NaNbO3-0.08Bi(Mg0.5Ti0.5)O3 Lead-Free Ceramics

Peng Nong,Yue Pan,Qinpeng Dong,Dafu Zeng,Mingzhao Xu,Xiang Wang,Jiaming Wang,Lian Deng,Xiuli Chen,Huanfu Zhou 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.1

NaNbO 3 -based lead-free ceramics are gaining widespread interest in recent years due to their environmental friendlinessand low density, which can meet the needs of future advanced pulse power electronics for low cost, miniaturization andintegration. However, a reversible phase transition of FE-AFE at room temperature for pure NaNbO 3 ceramic will producea large residual polarization, resulting in a low energy storage capacity. In this work, the ternary system (1- x )(0.92NaNbO 3 -0.08Bi(M g0.5 Ti 0.5 )O 3 )- x CaTiO 3 was designed by introducing the linear material CaTiO 3 doped into (0.92NaNbO 3 -0.08Bi(Mg 0.5 Ti 0.5 )O 3 ) ceramics to enhance the disorder of A/B sites in the system. The introduce of CaTiO 3 could optimizethe relaxation characteristics of the ceramics, refi ne the grain size to improve the breakdown fi eld strength( E b ), which enhancethe energy storage properties to W rec = 5.71 J/cm 3 and η = 85.7% at 475 kV/cm. Additionally, the 0.8(0.92NN-0.08BMT)-0.2CT ceramic achieves both temperature (20–160 °C) and frequency (5 Hz -120 Hz) stability, while also obtains excellentcharge/discharge performance( C D = 607.22 A/cm 2 , P D = 48.58 MW/cm 3 , t 0.9 = 28 ns), which indicates the great potentialapplication in pulsed power capacities.

Influence of lining materials on the detonation driving of fragments

Yue Ma,Yong He,Chuan Ting Wang,Yuan He,Cheng Ji,Lei Guo,Peng Chen 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

The shape and strength of prefabricated fragments changes to some extent after detonation loading. In this paper, detonation loading process of prefabricated fragments under two types of lining layers was studied and compared with no lining. By observing the recovered fragments, it was found that the inner part of the material was cracked and the shape of the fragments changed significantly. Comparing the two lining materials, the Kevlar/epoxy was better protective lining than polyurethane. The detonation process was analyzed qualitatively by using shock wave theory. In order to further explore the process, the simulation software LS-DYNA was used to carry out 3D simulation. The simulation results, in good agreement with the experimental results, showed that the Kevlar/Epoxy liner had a great influence on the initial velocity of the fragment. The experimental results and simulation results suggest that spherical fragments are better than cylindrical fragments in detonation drive application.

Effect of Microstructure on Thermal Conductivity of Polymer Composites

Yue Yang,Junjie Shu,Peng Chen,Ru Xia,Jiasheng Qian,Bin Yang,JIBIN MIAO,LIFEN SU,Zhengzhi Zheng,Ming Cao 한국고분자학회 2017 Macromolecular Research Vol.25 No.4

Thermal conductivity (TC) of polymer composites is strongly depended on thermal conductive fillers as well as heat conduction pathways formed by these fillers. In this work, we examined effects of morphology, size and arrangement of fillers on TC of polymer composites by using energy-conserving dissipative particle dynamic (e-DPD) simulation. Theoretically, we explored effects of ideal and “pseudo” thermal conductive pathways on composites’ TC and investigated heat conduction of filler particles with cubic-center and lamellar morphology. To confirm orientation and size effects of lamellar filler particles on composites’ TC, we prepared a series of Boron Nitride/Silicon rubber composites (BN/SiR). Being same with those observed in e-DPD simulation, orientation could efficiently improve TC of BN/SiR composites. The TC of composites with filled diameters about 10 micrometer of BN flats is 11 times higher than that of SiR matrix. Our researching results show that heat conduction pathways are essential to transportation of heat flux in polymer composites and even “pseudo” pathways by disconnected filler particles along temperature gradient can accelerate heat conduction.

Microstructure and mechanical properties of yttrium aluminum garnet porous ceramics prepared by different sintering process parameters

Yue Liu,Xueqing Yang,Kangliang Peng,Qiong Wang,Jianzhen Huang,Zilin Zhang,Jiang Lu,Hao Xu,Jieguang Song,Lin Chen 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.4

Yttrium aluminum garnet (YAG), which possesses excellent properties, is investigated and applied. The sintering technology of YAG porous ceramics is optimized. Results show that the porosity initially increases and then decreases with an increase of increasing temperature rate, the porosity are decreased with an increase of removing carbon temperature, the porosity are decreased with an increase of sintering temperature, the porosity are decreased with an increase of holding time. Meanwhile, the compressive strength constantly exhibits an opposite tendency. The optimization of the sintering technology of YAG porous ceramics is based on porosity and compressive strength. A good sintering technology are an increasing temperature rate of 8 oC/min, a removing carbon temperature of 800 oC, removing carbon time of 1 h, a sintering temperature of 1450 oC and holding time of 2 h. The porosity of the prepared YAG porous ceramics is 57.4%, and the compressive strength is 8.89 MPa.

Depression and APOEε4 Status in Individuals with Subjective Cognitive Decline: A Meta-Analysis

Yue-ping Huang,Ju-jun Xue,Chao Li,Xi Chen,Hong-juan Fu,Teng Fei,Peng-xiang Bi 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.9

Objective To evaluate the associative role of depression and apolipoprotein E epsilon 4 allele (APOEε4) in subjective cognitive decline(SCD) and its progression to objective cognitive decline. Methods After literature search in electronic databases, studies were selected by following precise eligibility criteria. Meta-analyses were performed to examine the role of APOEε4 and depression in SCD or its progression to mild cognitive impairment (MCI) or dementia. Results APOEε4 positivity was not different between SCD and normal individuals but was significantly higher in individuals with SCD plus than in normal individuals [odds ratio: 2.39 (95% CI: 1.87, 3.05); p<0.00001] and in SCD converters than in non-converters [odds ratio: 5.19 (95% CI: 2.36, 11.42); p<0.00001]. Depression was significantly higher in individuals with SCD [standardized mean difference: 0.63 (0.45, 0.82); p<0.00001] and SCD plus [standardized mean difference: 0.83 (0.43, 1.22); p<0.0001] than in normal individuals. However, depression was not different between SCD and MCI or between SCD converters and non-converters. Age of SCD converters was higher than non-converters [mean difference: 2.95 years (0.58, 5.31)]. Conclusion Whereas APOEε4 positivity was higher in SCD plus and SCD converters, depression was higher in SCD and SCD plus but was not different between SCD and MCI.