Optimization Model of Reliable Data Storage in Cloud Environment Using Genetic Algorithm

Feng Liu,Haitao Wu,Xiaochun Lu,Xiyang Liu 보안공학연구지원센터 2014 International Journal of Grid and Distributed Comp Vol.7 No.6

Massive data storage is one of the great challenges for cloud computing service, and reliable storage of sensitive data directly affects quality of storage service. In this paper, based on analysis of data storage process in cloud environment, the cost of massive data storage is considered to be comprised of data storage price, data migration and communication; and the storage reliability consists of data transmission reliability and hardware dependability. A multi-objective optimization model for reliable massive storage is proposed, in which storage cost and reliability are the objectives. Then, a genetic algorithm for solving the model is designed. Finally, experimental results indicate that the proposed model is positive and effective.

Esophageal/Gastric Cancer Screening in High-risk Populations in Henan Province, China

Lu, Yu-Fei,Liu, Zhi-Cai,Li, Zhong-Hong,Ma, Wen-Hao,Wang, Fu-Rang,Zhang, Ya-Bing,Lu, Jian-Bang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Objective: To summarize the endoscopic screening findings in high-risk population of esophageal and gastric carcinoma and analyze influential factors related to screening. Methods: In seven selected cities and counties with high incidences of esophageal carcinoma, people at age of 40-69 were set as the target population. Those with gastroscopy contradictions were excluded, and all who were voluntary and willing to comply with the medical requirements were subjected to endoscopic screening and histological examination for esophageal, gastric cardia and gastric carcinoma in accordance with national technical manual for early detection and treatment of cancer. Results: In three years, 36,154 people were screened, and 16,847 (46.60%) cases were found to have precancerous lesions. A total of 875 cases were found to have cancers (2.42%), and among them 739 cases had early stage with an early diagnosis rate is 84.5%. Some 715 patients underwent prompt treatment and the success rate was 81.8%. Conclusions: In a high-risk population of esophageal and gastric carcinoma, it is feasible to implement early detection and treatment by endoscopic screening. Screening can identify potential invasive carcinoma, early stage carcinoma and precancerous lesions, improving efficacy through early detection and treatment. The exploratory analysis of related influential factors will help broad implementation of early detection and treatment for esophageal and gastric carcinoma.

Strengthening effect of Ti₃C₂T_x in copper matrix composites prepared by molecular-level and high-shear mixings and SPS

Liu, Lu,Ying, Guobing,Wen, Dong,Hu, Cong,Zhang, Chen,Wang, Cheng Techno-Press 2021 Advances in nano research Vol.11 No.3

MXene (Ti₃C₂T_x) reinforced copper matrix composites with weight fractions of MXene from 1 to 4 wt.% were fabricated based on molecular-level and high-shear mixings and spark plasma sintering (SPS) method. The mechanical properties of the composites with different weight fractions of MXene were studied, and X-ray photoelectron spectroscopy (XPS) was used to track the state of MXene in the composite preparation process. Chemical state and interface transitions would result in an interesting ductile-brittle transition phenomenon of the composite. The Vickers hardness and compressive strength of the composites prepared by the molecular-level mixing and high-shear mixing methods have been improved (the maxima are 44.9% and 41.8%, respectively), where the addition of 1wt.% MXene results in a tensile strength increase of 29.9%. The results show that molecular-level mixing and high-shear mixing methods are hopeful to be applied to produce many kinds of MXene composites.

Adaptive Synchronization of Chua’s Circuit with an Uncertain Harmonic System

Lu Liu,Jie Huang 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Motivated by an adaptive synchronization problem for the Chua’s circuit with an uncertain harmonic system, we first consider an adaptive stabilization problem for a class of uncertain nonlinear systems with both dynamic and static uncertainties. A sufficient condition on the convergence of the estimated parameter to true parameter is also given. Then we show that the synchronization problem for the Chua’s circuit and the uncertain harmonic system can be converted into the adaptive stabilization problem under consideration. Finally, an adaptive feedback control law is designed such that, the output of the Chua’s circuit can asymptotically synchronize, in the presence of large parameter variations, with a sine function with arbitrary unknown frequency, amplitude, and phase angles.

High-Quality Water-Soluble Core/Shell/Shell CdSe/CdS/ZnS Quantum Dots Balanced by Ionic and Nonionic Hydrophilic Capping Ligands

Lu Liu,Hu Xu,Bing Shen,Xinhua Zhong 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.7

Pentaerythritol tetrakis 3-mercaptopropionate (PTMP) grafted poly(acryl acid) (PAA) ionic hydrophilic oligomer PAA-PTMP (PP) and dihydrolipoic acid (DHLA) grafted methoxypoly (ethylene glycol) (mPEG) nonionic hydrophilic oligomer mPEG-DHLA (PD) have been designed, synthesized and used as co-capping ligands in water-solubilization of hydrophobic quantum dots (QDs) via ligand exchange. The obtained oligomers with multi-thiol groups could bind strongly to the surface atoms of QDs. Meanwhile, the carboxyl groups (from PP) and mPEG segment (from PD) can render QDs water-soluble, and the free carboxylic groups can possibly be used for the further bioconjugation. The resulting water-soluble QDs have been characterized by ultraviolet-visible (UV-Vis), fluorescence, Fourier transform infrared (FTIR) spectroscopy as well as transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The water-soluble QDs have relatively small hydrodynamic size (10-12 nm), and importantly, retain high fluorescence quantum yields (up to 45%) compared with that of the originally hydrophobic QDs (49%). In addition, they have tunable surface charges and show excellent colloidal stability over a relatively broad pH range (2-13), in high salt concentration, and even after thermal treatment at 100℃. These results indicate that the water-soluble QDs coated by PP and PD oligomers have potential applications in cellular imaging and biosensor.

Olfactory response of female Bactroceraminax to chemical components of the preference host citrus volatile oils

Lu Liu, Qiong Zhou 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

Citrus fruit fly Bactrocera minax (Enderlein) (Diptera:Tephritidae) is a devastating pest of citrus plants in China. In order to characterize the behavioral mechanisms and possible chemical cues involved in host selection by female citrus fruit fly, the host plant volatiles was analyzed and Y-tube olfactometer assays were used. Host odor from citrus fruits peels elicited upwind orientation flights followed by landing and egg-laying, demonstrating the essential role of host plant volatiles in B. minax host-finding and oviposition behavior. GC–MS analysis of volatiles from the peels of three varieties citrus fruits, that were Bingtang sweet oranges (Citrus sinensis cv. Bingtang), Satsumas mandarins (Citrus reticulata cv. Satsuma) and Sour oranges (Citrus aurantium), which adult and larval of B. minax preferred to, showed that the major compounds extracted from the basal region were different from those of the distal region to some extent. Furthermore, in Y-tube olfactometer attraction assays, female flieswere significantly attracted (P b 0.05) to four out of the thirteen tested compounds from the citrus volatiles, including nonanal, citral, limonene and linalool. Conversely, furfuryl alcohol and guaiastil significantly repelled females (P b 0.05). The percentage composition of nonanal, citral, limonene and linalool from different regions of the fruits displayed a positive correlation with the numbers of egg marks made by females, whereas furfuryl alcohol and guaiastil displayed a correspondingly negative correlation. These results suggest that the oviposition preference of B. minax females is highly related to the chemical compounds emitted from host fruit peels.

Inhibitory effect of StCYP707A1 gene on tuberization in transgenic potato

Lu Liu,Rui-Jie Zhang,Wen-jiao Zhu,Xin-Ru Liu,Ke Shi,Min Chen,Qing Yang 한국식물생명공학회 2017 Plant biotechnology reports Vol.11 No.4

Tuber formation of potato is a complex biological process and is regulated by many factors including phytochrome, hormones, transcription factors, RNAs, microRNAs, etc. In our previous study, CYP707A1, an ABA 80-hydroxylase gene, was down-regulated in the StCOL antisense transgenic potato stolons, but its relation with potato tuberization has not been studied yet. In this study, to investigate the role of this gene in potato tuberization, we cloned a CYP707A1 gene from potato cultivar De ´sire ´e and constructed the StCYP707A1 over-expression and anti-sense potato lines by Agrobacterium-mediated transformation. In total, four over-expression transgenic lines and nine anti-sense transgenic lines were confirmed by PCR analysis. Semi-quantitative RT-PCR and qRTPCR analysis showed that the level of StCYP707A1 transcripts was significantly higher in the over-expression lines (A7 and A9) and lower in the anti-sense lines (F2 and F8), compared to the wild-type control. We further analyzed tuber formation in the transgenic lines and the wild-type control. The result showed that tuber yield per plant and average tuber weight were decreased in A7 and A9 and increased in F2. We also measured the content of ABA and GA3 in transgenic lines. ABA level was reduced in A7 and A9 and increased in F2. Contrariwise, the concentration of GA3 was higher in A7 and A9, and lower in F2 than in wild-type control. These results indicate that StCYP707A1 negatively affects potato tuberization through ABA regulation on gibberellic acid concentration.

Effect of bamboo and rice straw biochars on the mobility and redistribution of heavy metals (Cd, Cu, Pb and Zn) in contaminated soil

Lu, K.,Yang, X.,Gielen, G.,Bolan, N.,Ok, Y.S.,Niazi, N.K.,Xu, S.,Yuan, G.,Chen, X.,Zhang, X.,Liu, D.,Song, Z.,Liu, X.,Wang, H. Academic Press 2017 Journal of Environmental Management Vol.186 No.2

<P>Biochar has emerged as an efficient tool to affect bioavailability of heavy metals in contaminated soils. Although partially understood, a carefully designed incubation experiment was performed to examine the effect of biochar on mobility and redistribution of Cd, Cu, Pb and Zn in a sandy loam soil collected from the surroundings of a copper smelter. Bamboo and rice straw biochars with different mesh sizes (<0.25 mm and <1 mm), were applied at three rates (0, 1, and 5% w/w). Heavy metal concentrations in pore water were determined after extraction with 0.01 M CaCl2. Phytoavailable metals were extracted using DTPA/TEA (pH 7.3). The European Union Bureau of Reference (EUBCR) sequential extraction procedure was adopted to determine metal partitioning and redistribution of heavy metals. Results showed that CaCl2-and DTPA-extractable Cd, Cu, Pb and Zn concentrations were significantly (p < 0.05) lower in the bamboo and rice straw biochar treated soils, especially at 5% application rate, than those in the unamended soil. Soil pH values were significantly correlated with CaCl2-extractable metal concentrations (p < 0.01). The EUBCR sequential extraction procedure revealed that the acid extractable fractions of Cd, Cu, Pb and Zn decreased significantly (p < 0.05) with biochar addition. Rice straw biochar was more effective than bamboo biochar in decreasing the acid extractable metal fractions, and the effect was more pronounced with increasing biochar application rate. The effect of biochar particle size on extractable metal concentrations was not consistent. The 5% rice straw biochar treatment reduced the DTPA-extractable metal concentrations in the order of Cd < Cu < Pb < Zn, and reduced the acid extractable pool of Cd, Cu, Pb and Zn by 11, 17, 34 and 6%, respectively, compared to the control. In the same 5% rice straw biochar treatments, the organic bound fraction increased by 37, 58, 68 and 18% for Cd, Cu, Pb and Zn, respectively, compared to the control, indicating that the immobilized metals were mainly bound in the soil organic matter fraction. The results demonstrated that the rice straw biochar can effectively immobilize heavy metals, thereby reducing their mobility and bioavailability in contaminated soils. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Amperometric Immunosensor for Myeloperoxidase in Human Serum Based on a Multi-wall Carbon Nanotubes-Ionic Liquid-Cerium Dioxide Film-modified Electrode

Lu, Lingsong,Liu, Bei,Liu, Chenggui,Xie, Guoming Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.11

A label-free amperometric immunosensor has been proposed for the detection of myeloperoxidase (MPO) in human serum. To fabricate such an immunosensor, a composite film consisting of N,N-dimethylformamide (DMF), multiwall carbon nanotubes (MWCNTs) and 1-ethyl-3-methyl imidazolium tetrafluoroborate ($EMIMBF_4$) suspension was initially formed on a glassy carbon electrode (GCE). Then cerium dioxide ($CeO_2$) dispersed by chitosan was coated on the GCE. After that, MPO antibodies (anti-MPO) were attached onto the nano$CeO_2$ surface. With a noncompetitive immunoassay format, the antibody-antigen complex formed between the immobilized anti-MPO and MPO in sample solution. The immunosensor was characterized by cyclic voltammetry, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The factors influencing the performance of the immunosensor were studied in detail. Under optimal conditions, the current change before and after the immunoreaction was proportional to MPO concentration in the range of 5 to $300\;ng\;mL^{-1}$ with a detection limit of $0.2\;ng\;mL^{-1}$.

Synthesis of 2,5-Disubstituted Pyrrolidines from N-Alkenyl and Alkynyl N-Benzoyloxysulfonamides Catalyzed by (CuOTf)₂･C₆H₆

Liu, Wei-Min,Liu, Zhen-Hong,Cheong, Wei-Wen,Priscilla, Lu-Yi Teo,Li, Yongxin,Narasaka, Koichi Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.3

A new synthetic method of 2,5-disubstituted pyrrolidines is developed by the cyclization of unsaturated N-benzoyloxysulfonamides by $(CuOTf)_2{\cdot}C_6H_6$ in refluxing dichloroethane. Various N-4- and N-5-alkenyl and alkynyl N-benzoyloxysulfonamides are cyclized to give pyrrolidines. The cyclization proceeds via addition of sulfonamidoyl radicals to intramolecular unsaturated bonds or allylic hydrogen abstraction with the radical intermediates.