Geometric Optimization of a Mathematical Model of Radiofrequency Ablation in Hepatic Carcinoma

Wang, Kai-Feng,Pan, Wei,Wang, Fei,Wang, Gao-Feng,Madhava, Pai,Pan, Hong-Ming,Kong, De-Xing,Liu, Xiang-Guan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Radio frequency ablation (RFA) is an effective means of achieving local control of liver cancer. It is a particularly suitable mode of therapy for small and favorably located tumors. However, local progression rates are substantially higher for large tumors (>3.0 cm). In the current study, we report on a mathematical model based on geometric optimization to treat large liver tumors. A database of mathematical models relevant to the configuration of liver cancer was also established. The specific placement of electrodes and the frequency of ablation were also optimized. In addition, three types of liver cancer lesion were simulated by computer guidance incorporating mathematical models. This approach can be expected to provide a more effective and rationale mechanism for employing RFA in the therapy of hepatic carcinoma.

The Impact of Internet on Education : Towards and Emerging Paradigm

Kai Lung Hui,Shan Ling Pan,Bernard C . Y . Tan 한국경영정보학회 2001 한국경영정보학회 학술대회논문집 Vol.2001 No.-

Research Paper : Influences of long-term different types of fertilization on weed community biodiversity in rice paddy fields

( Kai Yuan Wan ),( Yong Tao ),( Ru Hai Li ),( Jun Feng Pan ),( Lei Lei Tang ),( Fang Chen ) 한국잡초학회 2012 Weed Biology and Management Vol.12 No.1

In order to provide a scientific basis for developing integrated weed management strategies in rice paddy fields, this study investigated the influences of different types of fertilization on weed biodiversity. The experiment was conducted at Long-term-located Monitoring Station for Soil Fertility, Agricultural Science Academy, of Jiangxi Province, China. Five fertilization treatments were set: no fertilization (NOF), PK, NP, NK, and NPK. The results showed that the influence of different fertilization treatments on weed community traits followed the models PK > NOF > NK > NP > NPK for species richness, PK > NOF > NK > NP > NPK for species diversity, NPK > NP > NK > NOF > PK for community dominance, and PK > NOF > NK > NP > NPK for community evenness. Under NPK (i.e. balanced fertilization), the weed species diversity and richness and weed community evenness were the lowest. The principal component analysis showed that the weed community was divided into three groups: (i) NK and a part of NOF; (ii) NP and NPK; and (iii) PK and NOF. The correlation analysis indicated that the influence of each macro-element on the weed community followed the model N > P > K. The organic content in the paddy soil might have played an equally important role with the amount of available N in determining the weed community`s characteristics. Regarding the way by which N, P, and K influenced the weed community, the amount of available P and K mainly influenced the organic content, while the amount of available N influenced both the organic content and light transmittance within the canopy, thereby enhancing the capacity of rice to compete with weeds.

Relationship of fractures in coal with lithotype and thickness of coal lithotype

Pan, Jienan,Wang, Haichao,Wang, Kai,Niu, Qinghe Techno-Press 2014 Geomechanics & engineering Vol.6 No.6

The fractures in coal are the main migration and output channels of coalbed methane, directly influencing the permeability of the coal seams. It is of great significance to study the effect of fracture distribution in coals on the permeability of coal seam. The development rules of endogenetic and exogenetic fractures are different among various coal lithotypes. There is also difference in the fracture density for the same lithotype with different thicknesses. Through the observation and description of the macroscopic fractures in coal and the origin of fractures in coal, the effect of the coal lithotype and its thickness on fracture development in coal was discussed. It was found through the study that the density of fractures in vitrain band was the maximum for the same coal rank and thickness, followed by clarain band. There were few fractures developed in the durain band. However, the changes of fracture density in three types of bands presented different declining trends for low, medium and high coal rank. There were no fractures developed in the fusain. There were three variation patterns for the fracture densities at the same coal rank and coal lithotype: linear decrease, nonlinear decrease, and first decrease then remaining unchanged. However, the overall trend was that the fracture density decreased with the increase of thickness of coal band for the same coal rank and coal lithotype.

Separation of Madecassoside and Madecassic Acid Isomers by High Performance Liquid Chromatography Using β -Cyclodextrin as Mobile Phase Additive

Kai, Guiqing,Pan, Jian,Yuan, Chuanxun,Yuan, Yuan Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.3

An improved HPLC method for the separation of madecassoside isomers (madecassoside and asiaticoside-B) has been developed. The isomers can be separated with high resolution from extracts of Centella asiatica by HPLC using $\beta$-cyclodextrin as a mobile phase added on a $C_{18}$ column. The result shows that the isomers can be separated with a mobile phase consisting of methanol:water (50:50, v/v) with 4 mmol/L $\beta$-CD. To elucidate the mechanism of the separation of madecassoside and asiaticoside-B, this paper studied the separation of their aglycon parts (madecassic acid and terminolic acid), another pair of isomers. The isomers can also be separated with high resolution with a mobile phase consisting of methanol:water (65:35, v/v) with 4 mmol/L $\beta$-CD and the pH of the mobile phase was adjusted to 4. The paper also studied the separation of the two isomers by HPLC using $\alpha$-CD and Glucosyl-$\beta$-CD as a mobile phase additive in order to elucidate the mechanism of the separation process.

Peroxisome Proliferator-Activated Receptor α Facilitates Osteogenic Differentiation in MC3T3-E1 Cells via the Sirtuin 1-Dependent Signaling Pathway

Kai Gong,Bo Qu,Cairu Wang,Jingsong Zhou,Dongfa Liao,Wei Zheng,Xianming Pan 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.6

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by lack of insulin and high glucose levels. T2DM can cause bone loss and fracture, thus leading to diabetic osteoporosis. Promoting osteogenic differentiation of osteoblasts may effectively treat diabetic osteoporosis. We previously reported that Sirtuin 1 (Sirt1), a NAD+-dependent deacetylase, promotes osteogenic differentiation through downregulation of peroxisome proliferator-activated receptor (PPAR) γ. We also found that miR-132 regulates osteogenic differentiation by downregulating Sirt1 in a PPAR /δ-dependent manner. The ligand-activated transcription factor, PPAR , is another isotype of the peroxisome proliferator-activated receptor family that helps maintain bone homeostasis and promot bone formation. Whether the regulatory role of PPAR in osteogenic differentiation is mediated via Sirt1 remains unclear. In the present study, we aimed to de-termine this role and the underlying mechanism by using high glucose (HG) and free fatty acids (FFA) to mimic T2DM in MC3T3-E1 cells. The results showed that HG-FFA significantly inhibited expression of PPAR , Sirt1 and osteogenic differentiation, but these effects were markedly reversed by PPAR overexpression. Moreover, siSirt1 attenuated the positive effects of PPAR on osteogenic differentiation, suggesting that PPAR promotes osteogenic differentiation in a Sirt1-dependent manner. Luciferase activity assay confirmed interactions between PPAR and Sirt1. These findings indicate that PPAR promotes osteogenic differentiation via the Sirt1-dependent signaling pathway.

Investigation of the Effect Mechanism of Cutting Sequence on Spiral Milling of CFRP/Ti Laminates Under Ultrasonic-Assisted Conditions

Kai Yang,Jie Pan,Ziyang Cao,Yiwen Zhu 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.25 No.4

The hole-making mechanism of carbon fiber reinforced plastic (CFRP)/titanium alloy stacks is different from that of monolayer materials. In order to reveal the effects of different cutting sequence strategies on the hole-making quality and machining efficiency of the stacked materials, valuable insights are provided for the design of the stacking machining process and the selection of the most suitable cutting sequence. The researchers conducted ultrasonic vibration-assisted helical milling and conventional helical milling experiments with different milling parameters, and explored the basic influence mechanisms of CFRP → Ti and Ti → CFRP on the hole-making in both ways. The results show that different cutting sequences have significant effects on the axial force and chip morphology changes during CFRP/Ti stack machining. The dimensional accuracy and consistency of the holes cut from the Ti side are better, and the quality of the entrance and exit from the Ti side under the ultrasonically assisted condition is close to the quality level of the holes cut from the CFRP side under the normal helical milling, and the ultrasonically assisted condition plays a good role in improving the quality of the holes made. In addition, the tearing coefficients of CFRP hole entry/exit in both machining modes increased with the increase of feed per tooth in tangential direction and decreased with the increase of spindle speed. The tearing coefficients of entry/exit holes in CFRP direction were smaller than those in titanium direction.

Image Quality Assessment with Saliency Map in Nonsubsampled Contourlet Transform Domain

Pan Wang,Wei Wu,Xiaomin Yang,Kai Liu,Gwanggil Jeon 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.6

Many researchers evaluate images by objective image quality assessments instead of subjective ones. Objective image quality assessment sets up mathematical model according to the human visual system, and it evaluates the image quality through the reference image and the distorted image. The Structural Similarity Index (SSIM) is one of the most classical methods in image quality assessment. However, SSIM has several inherent shortcomings. First, SSIM does not take spatial position, spatial frequency, or direction into account. Second, SSIM considers that different regions in an image have equal importance for overall image quality assessment. Third, it is unreasonable to use fixed parameters for various images. To overcome these shortcomings, we propose a new method of image quality assessment based on Nonsubsampled Contourlet Transform (NSCT). Firstly, NSCT is performed to decompose the image into a low-pass map and high-pass ones. Then, low-pass and high-pass maps are respectively assessed with different strategies. In addition, saliency map is added to describe the importance of different regions in an image. Last, we proposed an approach to calculate the adaptive parameters for various images. Experimental comparisons among five public benchmark databases demonstrate that the proposed method is better than other competing methods.

Dyadic Green

Kai Li,Seong Ook Park,Wei Yan Pan 한국전자파학회JEES 2001 Journal of Electromagnetic Engineering and Science Vol.1 No.1

Research on Community Knowledge Modeling of Readers Based on Interest Labels

Kai Wang,Wei Pan,Xingzhi Chen 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.1

Community portraits can deeply explore the characteristics of community structures and describe the personalizedknowledge needs of community users, which is of great practical significance for improving communityrecommendation services, as well as the accuracy of resource push. The current community portraits generallyhave the problems of weak perception of interest characteristics and low degree of integration of topic information. To resolve this problem, the reader community portrait method based on the thematic and timelinesscharacteristics of interest labels (UIT) is proposed. First, community opinion leaders are identified based onmulti-feature calculations, and then the topic features of their texts are identified based on the LDA topic model. On this basis, a semantic mapping including “reader community-opinion leader-text content” was established. Second, the readers' interest similarity of the labels was dynamically updated, and two kinds of tag parameterswere integrated, namely, the intensity of interest labels and the stability of interest labels. Finally, the similaritydistance between the opinion leader and the topic of interest was calculated to obtain the dynamic interest setof the opinion leaders. Experimental analysis was conducted on real data from the Douban reading community. The experimental results show that the UIT has the highest average F value (0.551) compared to the state-ofthe-art approaches, which indicates that the UIT has better performance in the smooth time dimension.