Simultaneous Information and Power Transfer for Multi-antenna Primary-Secondary Cooperation in Cognitive Radio Networks

Zhi Hui Liu,Wen Jun Xu,Sheng Yu Li,Cheng Zhi Long,Jia Ru Lin 한국전자통신연구원 2016 ETRI Journal Vol.38 No.5

In this paper, cognitive radio and simultaneous wireless information and power transfer (SWIPT) are effectively combined to design a spectrum-efficient and energy-efficient transmission paradigm. Specifically, a novel SWIPT-based primary-secondary cooperation model is proposed to increase the transmission rate of energy/spectrum constrained users. In the proposed model, a multi-antenna secondary user conducts simultaneous energy harvesting and information forwarding by means of power splitting (PS), and tries to maximize its own transmission rate under the premise of successfully assisting the data delivery of the primary user. After the problem formulation, joint power splitting and beamforming optimization algorithms for decode-and-forward and amplify-and-forward modes are presented, in which we obtain the optimal PS factor and beamforming vectors using a golden search method and dual methods. Simulation results show that the proposed SWIPTbased primary-secondary cooperation schemes can obtain a much higher level of performance than that of non-SWIPT cooperation and non-cooperation schemes.

Preparation and characterization of novel polyethylene/carbon nanotubes nanocomposites with core–shell structure

Zhi Liu,Qigu Huang,Mengshan Yu,Jing Wang,Fengjiao Li,Lu Cheng,Jiangping Guo,Yang Zhou,Baichun Zhu,Jianjun Yi,Yunfang Liu,Wantai Yang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Preparation of novel polyethylene/carbon nanotubes (CNTs) nanocomposites with core–shell structure was presented. The method involved in situ ethylene polymerization in which nanotube surface was treated with Grignard Agent, followed by reacting with active transition metal compound, TiCl4. The multiwalled carbon nanotubes (MWCNTs) supported catalysts polymerize ethylene to form polymer nanocomposite. MWCNTs were homogeneously dispersed within polymer matrix, and as expected, the resultant nanocomposites featured core–shell structure which was confirmed by HRTEM. For the nanocomposite, the microscopic examination of the cryogenically fractured surface not only ensured a good distribution of carbon nano-particles in the PE matrix but also revealed the ductile-like fracture. The Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were employed for the study of covalent sidewall functionalization and chemical bonding environment of MWCNTs, also indicated effective immobilization of titanium catalyst on the MWCNTs surface. The crystalline properties, dielectric property and thermal stability of the nanocomposites were determined by WAXD, impedance analyzer and TGA. The dielectric result showed a slight decline of the dielectric constant of the nanocomposites with increase of the polymerization time, and lower dielectric loss was also observed.

Antitumor Activity of Histone Deacetylase Inhibitor Trichostatin A in Osteosarcoma Cells

Cheng, Dong-Dong,Yang, Qing-Cheng,Zhang, Zhi-Chang,Yang, Cui-Xia,Liu, Yi-Wen Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Background: Histone deacetylase (HDAC) inhibitors have been reported to induce cell growth arrest, apoptosis and differentiation of tumor cells. The present study aimed to examine the effects of trichostatin A (TSA), one such inhibitor, on the cell cycle, apoptosis and invasiveness of osteosarcoma cells. Methods: MG-63 cells were treated with TSA at various concentrations. Then, cell growth and apoptosis were determined by 3-(4, 5-dimethyl-2-thiazolyl)-2H-tetrazolium bromide (MTT) and TUNEL assays, respectively; cell cycling was assessed by flow cytometry; invasion assays were performed with the transwell Boyden Chamber system. Results: MTT assays revealed that TSA significantly inhibited the growth of MG-63 cells in a concentration and time dependent manner. TSA treated cells demonstrated morphological changes indicative of apoptosis and TUNEL assays revealed increased apoptosis of MG-63 cells after TSA treatment. Flow cytometry showed that TSA arrested the cell cycle in G1/G2 phase and annexin V positive apoptotic cells increased markedly. In addition, the invasiveness of MG-63 cells was inhibited by TSA in a concentration dependent manner. Conclusion: Our findings demonstrate that TSA inhibits the proliferation, induces apoptosis and inhibits invasiveness of osteosarcoma cells in vitro. HDAC inhibitors may thus have promise to become new therapeutic agents against osteosarcoma.

Lack of Associations of the COMT Val158Met Polymorphism with Risk of Endometrial and Ovarian Cancer: a Pooled Analysis of Case-control Studies

Liu, Jin-Xin,Luo, Rong-Cheng,Li, Rong,Li, Xia,Guo, Yu-Wu,Ding, Da-Peng,Chen, Yi-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

This meta-analysis was conducted to examine whether the genotype status of Val158Met polymorphism in catechol-O-methyltransferase (COMT) is associated with endometrial and ovarian cancer risk. Eligible studies were identified by searching several databases for relevant reports published before January 1, 2014. Pooled odds ratios (ORs) were appropriately derived from fixed-effects or random-effects models. In total, 15 studies (1,293 cases and 2,647 controls for ovarian cancer and 2,174 cases and 2,699 controls for endometrial cancer) were included in the present meta-analysis. When all studies were pooled into the meta-analysis, there was no evidence for significant association between COMT Val158Met polymorphism and ovarian cancer risk (Val/Met versus Val/Val: OR=0.91, 95% CI=0.76-1.08; Met/Met versus Val/Val: OR=0.90, 95% CI=0.73-1.10; dominant model: OR=0.90, 95% CI=0.77-1.06; recessive model: OR=0.95, 95% CI=0.80-1.13). Similarly, no associations were found in all comparisons for endometrial cancer (Val/Met versus Val/Val: OR 0.97, 95% CI=0.77-1.21; Met/Met versus Val/Val: OR=1.02, 95% CI=0.73-1.42; dominant model: OR=0.98, 95% CI=0.77-1.25; recessive model: OR=1.02, 95% CI=0.87-1.20). In the subgroup analyses by source of control and ethnicity, no significant associations were found in any subgroup of population. This meta-analysis strongly suggests that COMT Val158Met polymorphism is not associated with increased endometrial and ovarian cancer risk.

Development and Evaluation of Loop-Mediated Isothermal Amplification Assay for Rapid Detection of Tylenchulus semipenetrans Using DNA Extracted from Soil

Zhi-Qiang Song,Ju-E Cheng,Fei-Xue Cheng,De-Yong Zhang,Yong Liu 한국식물병리학회 2017 Plant Pathology Journal Vol.33 No.2

Tylenchulus semipenetrans is an important and widespreadplant-parasitic nematode of citrus worldwideand can cause citrus slow decline disease leading tosignificant reduction in tree growth and yield. Rapidand accurate detection of T. semipenetrans in soil isimportant for the disease forecasting and management. In this study, a loop-mediated isothermal amplification(LAMP) assay was developed to detect T. semipenetrans using DNA extracted from soil. A setof five primers was designed from the internal transcribedspacer region (ITS1) of rDNA, and was highlyspecific to T. semipenetrans. The LAMP reaction wasperformed at 63°C for 60 min. The LAMP productwas visualized directly in one reaction tube by addingSYBR Green I. The detection limit of the LAMP assaywas 10–2 J2/0.5 g of soil, which was 10 times moresensitive than conventional PCR (10–1 J2/0.5 g of soil). Examination of 24 field soil samples revealed that theLAMP assay was applicable to a range of soils infestednaturally with T. semipenetrans, and the total assaytime was less than 2.5 h. These results indicated thatthe developed LAMP assay is a simple, rapid, sensitive,specific and accurate technique for detection of T. semipenetrans in field soil, and contributes to the effectivemanagement of citrus slow decline disease.

Key Application Technologies of High Efficiency Power Quality Control Systems

Liu, Ding-Guo,Shuai, Zhi-Kang,Tu, Chun-Ming,Cheng, Ying,Luo, An The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.3

Large capacity reactive power compensation and harmonic control in the low-voltage grid of an enterprise, are important technical means to improve power quality and reduce power loss. In this paper, the principle of an efficient power quality controller is analyzed. Then, key application technologies of the HPQC which would influence the performances of the HPQC are studied. Based on an analysis of the harmonic shunt problem, a frequency dividing control strategy of the HPQC continuous subsystem is proposed. A parameter design method of the HPQC discrete subsystem and its installation method are also proposed to ensure the system compensation effect. HPQC systems have been designed for a copper foil plant. The effectiveness of this paper has been verified by the simulation and application results.

Dronedarone Attenuates Ang II-Induced Myocardial Hypertrophy Through Regulating SIRT1/FOXO3/PKIA Axis

Cheng Chen,Song Hu,Heng-Jing Hu,Zhi-Xuan Liu,Xin-Teng Wu,Tao Zou,Hua Su 대한심장학회 2024 Korean Circulation Journal Vol.54 No.4

Background and Objectives: Long-term pathological myocardial hypertrophy (MH) seriously affects the normal function of the heart. Dronedarone was reported to attenuate left ventricular hypertrophy of mice. However, the molecular regulatory mechanism of dronedarone in MH is unclear. Methods: Angiotensin II (Ang II) was used to induce cell hypertrophy of H9C2 cells. Transverse aortic constriction (TAC) surgery was performed to establish a rat model of MH. Cell size was evaluated using crystal violet staining and rhodamine phalloidin staining. Reverse transcription quantitative polymerase chain reaction and western blot were performed to detect the mRNA and protein expressions of genes. JASPAR and luciferase activity were conducted to predict and validate interaction between forkhead box O3 (FOXO3) and protein kinase inhibitor alpha (PKIA) promoter. Results: Ang II treatment induced cell hypertrophy and inhibited sirtuin 1 (SIRT1) expression, which were reversed by dronedarone. SIRT1 overexpression or PKIA overexpression enhanced dronedarone-mediated suppression of cell hypertrophy in Ang II-induced H9C2 cells. Mechanistically, SIRT1 elevated FOXO3 expression through SIRT1-mediated deacetylation of FOXO3 and FOXO3 upregulated PKIA expression through interacting with PKIA promoter. Moreover, SIRT1 silencing compromised dronedarone-mediated suppression of cell hypertrophy, while PKIA upregulation abolished the influences of SIRT1 silencing. More importantly, dronedarone improved TAC surgery-induced MH and impairment of cardiac function of rats via affecting SIRT1/FOXO3/PKIA axis. Conclusions: Dronedarone alleviated MH through mediating SIRT1/FOXO3/PKIA axis, which provide more evidences for dronedarone against MH.

Flatness Measurement of a Mosaic Focal Plane by using a Coaxial Multispectral Laser

Liu Chang-hua,Guo Ning-Xin,Wang Jian-Li,Chen Tao,Wu Zhi-Yong,Cheng Xue 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.8

The wide-field telescope will be an important tool in the discovery and birth of new theories of astronomy in future. The detectors in this kind of telescope mostly adopt a mosaic focal plane array. The focal depth of a large-F-number optical system is very small, and the flatness of the mosaic detector should be less than half the focal depth. In this paper, a new flatness measurement and data processing method is developed. A flatness measurement platform composed of a high-precision gantry platform and a coaxial multispectral displacement meter was built. The flatness of a single detector was measured under uncooled and cooled working conditions, and data processing was conducted, in which the root mean square (RMS) and the peak–valley (PV) values of the cooled detector were 0.0017 mm and 0.0112 mm, respectively. Next, a 2 × 6 mosaic model of the focal plane with a dimension of 148.5 mm × 168.5 mm was built using a metal detector model. The measurement platform was used to measure the flatness of the mosaic focal plane. According to the measurement results, the preliminary installation and mosaic adjustment were completed. The final RMS and PV values of the mosaic focal plane are 0.009 mm and 0.0808 mm, respectively. The experimental results show that the measurement and the data processing method can accurately reflect surface information on the detectors. This suggests that the method has great potential for use in ensuring the accuracy of wide-field telescope equipment in all applicable research areas.

Prognostic Value of Vascular Endothelial Growth Factor Expression in Resected Gastric Cancer

Liu, Lei,Ma, Xue-Lei,Xiao, Zhi-Lan,Li, Mei,Cheng, Si-Hang,Wei, Yu-Quan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Background and Aims: Vascular endothelial growth factor (VEGF) is a potential prognostic biomarker for patients with resected gastric cancer. However, its role remains controversial. The objective of this study was to conduct a systematic review and meta-analysis of published literature. Methods: Relevant literature was identified using Medline and survival data from published studies were collected following a methodological assessment. Quality assessment of eligible studies and meta-analysis of hazard ratio (HR) were performed to review the correlation of VEGF overexpression with survival and recurrence in patients with gastric cancer. Results: Our meta-analysis included 44 published studies with 4,794 resected patients. VEGF subtype for the prediction of overall survival (OS) included tissue VEGF (HR=2.13, 95% CI 1.71-2.65), circulating VEGF (HR=4.22, 95% CI 2.47-7.18), tissue VEGF-C (HR=2.21, 95% CI 1.58-3.09), tissue VEGF-D (HR=1.73, 95% CI 1.25-2.40). Subgroup analysis showed that HRs of tissue VEGF for OS were, 1.78 (95% CI 0.90-3.51) and 2.31 (95% CI 1.82-2.93) in non-Asians and Asians, respectively. The meta-analysis was also conducted for disease free survival (DFS) and disease specific survival (DSS). Conclusion: Positive expression of tissue VEGF, circulating VEGF, VEGF-C and VEGF-D were all associated with poor prognosis in resected gastric cancer. However, VEGF demonstrated no significant prognostic value for non-Asian populations. Circulating VEGF may be better than tissue VEGF in predicting prognosis.

Meshing analysis and optimization for plane-generated enveloping toroid hourglass worm drive

Zhi Liu,Hong Lu,Qingmeng Wang,Zhangjie Li,Qianju Cheng 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.7

Optimal design parameter combination and transmission optimization for planegenerated enveloping toroid hourglass worm drive are proposed. The modeling frame and mathematical model of the worm were constructed first to provide a perfect transmission. Then, the mathematical representations of transmission performance, including lubrication angle, induced normal curvature, and length of meshing line for worm drive, were derived according to differential geometry and coordinate transformation approach. In addition, the influence of various design parameters on transmission performance was associated with main parameters, and the influence of the main parameters on transmission was evaluated. Next, a multivariate transmission optimization considering lubrication effect, bearing capacity and contact strength was conducted in view of the whole meshing cycle. The optimal global solution of the multivariate optimization model was also evaluated using a genetic algorithm. Calculation and experimental results indicated the optimization study was in good agreement with experimental results. Finally, the comprehensive transmission performance of the worm drive has an increase of 9.2 %.