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Search Results: 1 - 10 of 5028 matches for " Weijun Guan "
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Land use change of Kitakyushu based on landscape ecology and Markov model

GUAN Dongjie,GAO Weijun,WATARI Kazuyuki,FUKAHORI Hidetoshi,

地理学报 , 2008,
Abstract: Based on four phases of TM images acquired in 1990, 1995, 2000 and 2005, this paper took Kitakyushu in Japan as a case study to analyze spatial change of land use landscape and corresponding effects on environmental issues guided by landscape ecology theory in virtue of combining technology of Remote Sensing with GIS. Firstly, land use types were divided into 6 classes (farmland, mountain, forestland, water body, urban land and unused land) according to national classification standard of land use, comprehensible ability of TM image and purpose of this study. Secondly, following the theory of landscape ecology analysis, 11 typical landscape indices were abstracted to evaluate the environmental effects and spatial feature changes of land use. Research results indicated that land use has grown more and more diversified and unbalanced, human activities have disturbed the landscape more seriously. Finally, transfer matrix of Markov was applied to forecast change process of land use in the future different periods, and then potential land use changes were also simulated from 2010 to 2050. Results showed that conversion tendency for all types of land use in Kitakyushu into urban construction land were enhanced. The study was anticipated to help local authorities better understand and address a complex land use system, and develop improved land use management strategies that could better balance urban expansion and ecological conservation.
Transplantation of Porcine Hepatocytes Cultured with Polylactic Acid-O-Carboxymethylated Chitosan Nanoparticles Promotes Liver Regeneration in Acute Liver Failure Rats
Zhong Chen,Renan Chang,Weijun Guan,Hongyu Cai,Fei Tang,Wencai Zhu,Jiahui Chen
Journal of Drug Delivery , 2011, DOI: 10.1155/2011/797503
Abstract: In this study, free porcine hepatocytes suspension (Group A), porcine hepatocytes embedded in collagen gel (Group B), porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel (Group C), and PLA-O-CMC nanoparticles alone (Group D) were transplanted into peritoneal cavity of ALF rats, respectively. The result showed that plasma HGF levels were elevated post-transplantation with a peak at 12 hr. The rats in Group C showed highest plasma HGF levels at 2, 6, 12, 24 and 36 hr post-transplantation and lowest HGF level at 48 hr. Plasma VEGF levels were elevated at 48 hr post-transplantation with a peak at 72 hr. The rats in Group C showed highest plasma HGF levels at 48, 72, and 96 hr post-transplantation. The liver functions in Group C were recovered most rapidly. Compared with Group B, Group C had significant high liver Kiel 67 antigen labeling index (Ki-67 LI) at day 1 post-HTx (<.05). Ki-67 LI in groups B and C was higher than that in groups A and D at days 5 and 7 post-HTx. In conclusion, intraperitoneal transplantation of porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel can promote significantly liver regeneration in ALF rats.
Characterization of vascular endothelial progenitor cells from chicken bone marrow
Chunyu Bai, Lingling Hou, Minghai Zhang, Yabin Pu, Weijun Guan, Yuehui Ma
BMC Veterinary Research , 2012, DOI: 10.1186/1746-6148-8-54
Abstract: We found that the majority of chicken EPCs were spindle shaped. The growth-curves of chicken EPCs at passages (P) 1, -5 and -9 were typically “S”-shaped. The viability of chicken EPCs, before and after cryopreservation was 92.2% and 81.1%, respectively. Thus, cryopreservation had no obvious effects on the viability of chicken EPCs. Dil-ac-LDL and FITC-UAE-1 uptake assays and immunofluorescent detection of the cell surface markers CD34, CD133, VEGFR-2 confirmed that the cells obtained in vitro were EPCs. Observation of endothelial-specific Weibel-Palade bodies using transmission electron microscopy further confirmed that the cells were of endothelial lineage. In addition, chicken EPCs differentiated into endothelial cells and smooth muscle cells upon induction with VEGF and PDGF-BB, respectively, suggesting that the chicken EPCs retained multipotency in vitro.These results suggest that chicken EPCs not only have strong self-renewal capacity, but also the potential to differentiate into endothelial and smooth muscle cells. This research provides theoretical basis and experimental evidence for potential therapeutic application of endothelial progenitor cells in the treatment of atherosclerosis, vascular injury and diabetic complications.Endothelial progenitor cells (EPCs) are precursors of vascular endothelial cells. Progenitor cells [1]. EPCs originate from bone marrow with similar angioblast and umbilical vein endothelial cells, which together belong to a subgroup of hematopoietic stem cells [2].There are two types of EPCs that can be detected in vitro, early and late EPCs. While early EPCs display a linear growth structure termed spindle-shaped, late EPCs form cobblestone-like, oval shaped strutures [3]. EPCs not only take part in vascularization during embryonic development, but also participate in postnatal vascularization and reparative processes post-trauma [4]. Therefore, EPCs hold extensive prospects for vascular tissue engineering and possible clinical applic
Establishment and Biological Characteristics of Hereford Cattle Fibroblast Bank
Shen Wu,Wenxiu Zhang,Changli Li,Mei Li,Weijun Guan,Yuehui Ma
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2012.1763.1770
Abstract: A fibroblast line from kindey tissue of Hereford cattle was established successfully by direct culture of explants and biology cryopreservation techniques. The cell line contained 101 tubes of frozen cells from 34 primary kidney samples. Biological analysis showed that the cells were morphologically consistent with fibroblasts and the growth curve was sigmoidal with a Population Doubling Time (PDT) of 35 h.The average viability of the cells was 95.8% before freezing and 93.4% after thawing. Cross-contamination among cell lines was excluded by isoenzyme analysis of Lactate Dehydrogenase (LDH) and Malate Dehydrogenase (MDH). The frequency of cells having the diploid chromosome number (60) was 97.5%. Detection of bacteria, fungi, viruses and mycoplasmas was verified negative. At 24, 48 and 72 h after transfection, the expression efficiency of fluorescent protein genes (pEGFP-N3, pEYFP-N1 and pDsRed1-N1) were between 18.6~32%; The fluorescence could be observed well-distributed in cytoplasm and nucleus in addition to some cryptomere vesicles at 12 h after transfection.
The Apoptotic Effects of Alcohol Shock on Bovine Oocytes
Xiangchen Li,Yaxin Yao,Peng Liu,Dapeng Jin,Weijun Guan,M.A. Yuehui
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2011.2679.2682
Abstract: Bovine oocytes collected from slaughterhouse should be subject to rigorous antiseptic procedures. In this lab, alcohol immersion was applied for preventing microbial infection instead of antibiotics. However, it remains to be investigated whether alcohol treatment would lead to unpredictable results. In the present study, the ovaries were fully washed with 75% alcohol for 1, 5 and 10 min, respectively. Only in the 10 min group, the oocytes apoptotic rates significantly increased (p<0.05) and the development rates significantly decreased (p<0.01) while detectable difference in apoptosis was not observed. Therefore, washing ovaries with 75% alcohol for <5 min constitutes no obvious influences on the development of oocytes and embryos and could be used as a convenient and rapid method to prevent microbial contamination.
Establishment and Biological Characteristics of Qing Kedan Chicken Embryonic Fibroblast Line for Genetic Resource Conservation
Hui Wang,Xiangchen Li,Changli Li,Wenxiu Zhang,Weijun Guan,Yuehui Ma
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2012.4374.4381
Abstract: A fibroblast cell line of Qing Kedan chicken was successfully isolated, purified and cryopreseved through direct culturing of explants, serial passage and cryogenic techniques. Assays for biological characteristics were conducted and the results suggested that: the cells cultured with a Population Doubling Time (PDT) of about 20 h, constituted a typical fibroblast cell line in morphology; tests for microbial contamination regarding bacteria, fungi, viruses and mycoplasmas were exclusively negative; Lactate Dehydrogenase (LDH) and Malate Dehydrogenase (MDH) polymorphism analysis disproved the existence of cross-contamination from other cell lines; diploid cells making up 85-93% of the population verified the hereditary stability of the fibroblast line. pEGFP-N3, pEYFP-N1 and pDsRed1-N1 were transfected into the Qing Kedan chicken embryonic fibroblasts with transfection efficiencies between 12.6 and 39.7%. To locate their cellular distribution, transfected cells were observed at 24, 48 and 72 h with confocal microscopy and the fluorescences could be observed throughout the cytoplasm and nuclei of positive cells except in cryptomere vesicles. This research preserved the precious germplasm resource of Qing Kedan chicken at cell level and hence served as an enlightening reference for those of other poultry in the world.
Relative Widths of Some Sets of lmp  [PDF]
Weiwei Xiao, Weijun Luan
Advances in Pure Mathematics (APM) , 2011, DOI: 10.4236/apm.2011.12008
Abstract: n this paper, the relative widths of some sets in are studied. Relative widths is the further development of Kolmogorov widths and it is a new problem in approximation theory which aroused some mathematics workers great interest recently. We present some basic propositions of relative widths and investigate relative widths of some sets (ball or ellipsoid) of
Present Assessment of Public Traffic System Based on GIS in Kitakyushu  [PDF]
Kazuyuki Watari, Weijun Gao
Open Journal of Civil Engineering (OJCE) , 2014, DOI: 10.4236/ojce.2014.44034
Abstract: With increasing of serious environment problems and the coming of the aging society, new traffic systems should be urgently rebuilt. It is necessary to evaluate the traffic service level by utilizing new technique and tool. This paper takes Kitakyushu city as case study to carry out an evaluation of urban traffic system. The concept of accessibility and mobility is used to evaluate the present condition of existing public traffic system based on GIS technology, and then establishment of new route is discussed according to the evaluation results. Additionally, this paper established GIS database and illustrated the relationship between the public traffic and population density. The regions without enough existing traffic were identified. Moreover, the essential terms and considerations were put forward to simulate a new route of public traffic line.
Airfoil Trailing Edge Noise Generation and Its Surface Pressure Fluctuation  [PDF]
Weijun Zhu, Wenzhong Shen
Journal of Power and Energy Engineering (JPEE) , 2015, DOI: 10.4236/jpee.2015.37003
Abstract:

In the present work, Large Eddy Simulation (LES) of turbulent flows over a NACA 0015 airfoil is performed. The purpose of such numerical study is to relate the aerodynamic surface pressure with the noise generation. The results from LES are validated against detailed surface pressure measurements where the time history pressure data are recorded by the surface pressure microphones. After the flow-field is stabilized, the generated noise from the airfoil Trailing Edge (TE) is predicted using the acoustic analogy solver, where the results from LES are the input. It is found that there is a strong relation between TE noise and the aerodynamic pressure. The results of power spectrum density show that the fluctuation of aerodynamic pressure is responsible for noise generation.

Simulation Studies of Diesel Engine Combustion Characteristics with Oxygen Enriched Air  [PDF]
Heng Wang, Weijun Liu
Journal of Power and Energy Engineering (JPEE) , 2015, DOI: 10.4236/jpee.2015.38002
Abstract: Based on a six-cylinder direct injection diesel engine, the engine operating condition was simulated by application AVL-FIRE software coupling the n-heptane reduced mechanism containing polycyclic aromatic hydrocarbon (PAH) formation. The simulation and its verification test were both carried out under the maximum torque point. Then, the oxygen enriched combustion was simulated on the model, and the simulated condition was oxygen volume fraction from 21% to 30%. The simulation results show that, the oxygen enrichment (from 21% to 30%) increases the peak cylinder pressure of 3.32%, advances the start of combustion of 1.6 deg and rises the peak of average temperature in cylinder and wall heat flux. Among them, at the condition of 24% O2, the change of the results is the most significant. Benzene (A1) is one of the precursors of soot generated, the analysis of its impress-cuts of the mass distribution field in cylinder shows that, the increase of oxygen concentration can significantly inhibit the formation of benzene. But the oxygen enrichment makes the combustion more sufficient, cased a rise in the cylinder temperature, an extension in high temperature area, and an increment in the NOx emission.
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