• Title/Summary/Keyword: Q-Factor

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Design of a Waveguide Band-Pass Filter Using a Modified H-type Resonant Iris (변형된 H-형 공진 아이리스를 이용한 도파관 대역통과 여파기 설계)

  • Park, Kyoung-Je;Choi, Tae-Ho;Lee, Jong-Ig;Kim, Byung-Mun;Cho, Young-Ki
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.2
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    • pp.347-353
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    • 2018
  • In this paper, we studied a design method for a band-pass waveguide filter with a modified H-type resonant iris (RI) placed in a thin transverse wall of a rectangular waveguide. The horizontal straight gap at the center of a conventional H-shaped iris is modified to a U-shaped one to increase the equivalent capacitance, and the equivalent inductance is improved by changing the vertical two straight slots into C-shaped ones. From some simulation results for the frequency response of the proposed RI, it was observed that the proposed iris was advantageous for reducing its size and having better cutoff, compared to typical H-shaped one. Equivalent inductance, capacitance, and quality factor of the proposed RI were extracted to analyze its performance. A third-order band pass filter using the proposed modified H-shaped iris was designed and, it was observed that the filter operated in the frequency range of 9.18-9.84 GHz with its insertion loss of 0.3 dB and return loss of 14 dB.

Biosurfactant as a microbial pesticide

  • Lee, Baek-Seok;Choi, Sung-Won;Choi, Ki-Hyun;Lee, Jae-Ho;Kim, Eun-Ki
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.40-44
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    • 2003
  • Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

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Modulated Gene Expression of Toxoplasma gondii Infected Retinal Pigment Epithelial Cell Line (ARPE-19) via PI3K/Akt or mTOR Signal Pathway

  • Zhou, Wei;Quan, Juan-Hua;Gao, Fei-Fei;Ismail, Hassan Ahmed Hassan Ahmed;Lee, Young-Ha;Cha, Guang-Ho
    • Parasites, Hosts and Diseases
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    • v.56 no.2
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    • pp.135-145
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    • 2018
  • Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, $CK2{\beta}$, VEGF, GCL, GST and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.

Polysaccharide isolated from fermented barley extract activates macrophages via the MAPK and NF-κB pathways (보리발효추출물로부터 분리한 다당의 대식세포 활성화 및 신호 전달)

  • Kim, Han Wool;Jee, Hee Sook;Shin, Kwang-Soon
    • Korean Journal of Food Science and Technology
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    • v.50 no.5
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    • pp.555-563
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    • 2018
  • Barley has nutritional benefits due to its high dietary fiber content; therefore, the intake of whole barley grains is recommended. However, barley is often consumed in the fermented form because of the improved texture and digestibility. The present study was designed to elucidate the intracellular signaling pathway for macrophage activation by the polysaccharide BF-CP from fermented barley. BF-CP is a neutral polysaccharide, composed of neutral sugars, including glucose (70.7%), xylose (11.4%), and arabinose (9.0%). BF-CP exhibited macrophage-stimulatory activity by inducing the production of interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, and nitric oxide in RAW 264.7 macrophages. Further, BF-CP treatment strongly increased the IL-6 and $TNF-{\alpha}$ gene expression in a concentration-dependent manner. Signal transduction experiments using immunoblotting showed that BF-CP phosphorylated mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38, and nuclear factor $(NF)-{\kappa}B$, in RAW 264.7 cells in a concentration-dependent manner. These results suggest that BF-CP activates the macrophages via MAPK and $NF-{\kappa}B$ pathways, and also induces an increase in the production of cytokines.

Development of the Technology Valuation Analysis Indicators Using the Delphi Method in the Offset Program (델파이 기법을 활용한 절충교역 기술가치평가 분석지표 개발)

  • Hong, Seoksoo;Seo, Jae-Hyun
    • Journal of Korea Technology Innovation Society
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    • v.16 no.1
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    • pp.252-278
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    • 2013
  • Many countries implement an offset program as a method of the acquisition of modern military technology for enhancement of the domestic military strength. Offset agreements are made based on the value, not a monetary unit. The value should be above minimum threshold fixed by the related regulation. Hence, technology valuation model which is objective and reasonable is required vitally. At present, some defense related organizations such as DTaQ, ADD valuate the proposed technology by using their own method. However, due to the lack of differentiation of valuation analysis indicators for various technologies, existing offset valuation models are inadequate to consider whole characteristics of such technologies. In this paper, we developed four sets of offset valuation analysis indicators considering the characteristics of each technology, parts production, depot maintenance, military equipment performance upgrade, and R&D related technology, by using the Delphi method. Also, we structurized those indicators in each technology by using the factor analysis. Through applying developed indicators, it is expected that technology valuation in the offset program would be more credible and accurate. Ultimately, it gives greater bargaining power to negotiators in the procedure of the offset negotiation.

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Isolation, Expression Pattern, Polymorphism and Association Analysis of Porcine TIAF1 Gene

  • Wang, Y.;Xiong, Y.Z.;Ren, Z.Q.;Zuo, B.;Lei, M.G.;Deng, C.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.3
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    • pp.313-318
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    • 2009
  • TIAF1 is a TGF-${\beta}$1-induced anti-apoptotic factor that plays a critical role in blocking TNF (tumor necrosis factor) cytotoxicity in mouse fibroblasts and participates in TGF-${\beta}$-mediated growth regulation. In this study, we obtained the full-length cDNA sequence of the porcine TIAF1 gene. Real-time PCR further revealed that the TIAF1 gene was expressed at the highest level in liver and kidney with prominent expressions detected in uterus, and lower levels detected in heart, spleen, lung, stomach, small intestine, skeletal muscle and fat of Large White pigs. Sequence analysis indicated that a 6 base-pair deletion mutation existed in the exon of the TIAF1 gene between Meishan and Large White pigs. This mutation induced deletion of Gln and Val amino acids. PCR-RFLP was used to detect the polymorphism in 394 pigs of a "Large White${\times}$Meishan" $F_{2}$ resource population and four purebred pig populations. The frequencies of the A allele (with a 6 bp deletion) were dominant in Chinese Meishan and Bamei pigs, and the frequencies of the B allele (no 6 bp deletion) were dominant in Large White and Landrace pigs. Association analyses revealed that the deletion mutation had highly significant associations (p<0.01) with meat marbling score of the thorax-waist longissimus dorsi (LD) muscle (MM1) and intramuscular fat percentage (IMF), and significant associations (p<0.05) with carcass length (CL). The results presented here supply evidence that the 6 bp deletion mutation in the TIAF1 gene affects porcine meat quality and provides useful information for further porcine breeding.

Effects of Pre-synthesized $BaTiO_3$ Addition on the Microstructure and Dielectric/ Piezoelectric Properties of $(Bi_{0.5}Na_{0.5})_{0.94}Ba_{0.06}TiO_3$ Piezoelectric Ceramics

  • Khansur, Neamul Hayet;Yoon, Man-Soon;Kweon, Soon-Yong;Lee, Young-Geun;Ur, Soon-Chul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.189-189
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    • 2008
  • Due to the environmental issue vast research is going on to replace the widely used lead contented piezoelectric materials. Bismuth sodium titanate (abbreviated as BNT) based bismuth sodium titanate-barium titanate (abbreviated as BNBT) ceramic was prepared by using modified method rather than conventional mixed oxide method. This modification was made to improve the properties of BNT based ceramic. In this procedure $BaTiO_3$ (abbreviated as BT) was prepared using conventional mixed oxide method. Analytical grade raw materials of $BaCO_3$ and $TiO_2$ were weighted and ball milled using ethanol medium. The mixed slurry was dried and sieved under 80 mesh. Then the powder was calcined at $1100^{\circ}C$ for 2 hours. This calcined BT powder was used in the preparation of BNBT. Stoichiometric amount of $Bi_2O_3$, $Na_2CO_3$, $TiO_2$ and BT were weighted and mixed by using ball mill. The used calcination temperature was $850^{\circ}C$ for 2 hours. Calcined powder was taken for another milling step. BNBT disks were pressed to 15 mm of diameter and then cold isostatical press (CIP) was used. Pressed samples were sintered at $1150^{\circ}C$ for 2 hours. The SEM microstructure analysis revealed that the grain shape of the sintered ceramic was polyhedral and grain boundary was well matched where as the sample prepared by conventional method showed irregular arrangement and grain boundary not well matched. And sintered density was better (5.78 g/cc) for the modified method. It was strongly observed that the properties of BNBT ceramic near MPB composition was found to be improved by the modified method compare to the conventional mixed oxide method. The piezoelectric constant dB of 177.33 pC/N, electromechanical coupling factor $k_p$ of 33.4%, dielectric constant $K_{33}^T$ of 688.237 and mechanical quality factor $Q_m$ of 109.37 was found.

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Astragaloside IV Prevents Obesity-Associated Hypertension by Improving Pro-Inflammatory Reaction and Leptin Resistance

  • Jiang, Ping;Ma, Dufang;Wang, Xue;Wang, Yongcheng;Bi, Yuxin;Yang, Jinlong;Wang, Xuebing;Li, Xiao
    • Molecules and Cells
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    • v.41 no.3
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    • pp.244-255
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    • 2018
  • Low-grade pro-inflammatory state and leptin resistance are important underlying mechanisms that contribute to obesity-associated hypertension. We tested the hypothesis that Astragaloside IV (As IV), known to counteract obesity and hypertension, could prevent obesity-associated hypertension by inhibiting pro-inflammatory reaction and leptin resistance. High-fat diet (HFD) induced obese rats were randomly assigned to three groups: the HFD control group (HF con group), As IV group, and the As IV + ${\alpha}$-bungaratoxin (${\alpha}-BGT$) group (As IV+${\alpha}-BGT$ group). As IV ($20mg{\cdot}Kg^{-1}{\cdot}d^{-1}$) was administrated to rats for 6 weeks via daily oral gavage. Body weight and blood pressure were continuously measured, and NE levels in the plasma and renal cortex was evaluated to reflect the sympathetic activity. The expressions of leptin receptor (LepRb) mRNA, phosphorylated signal transducer and activator of transcription-3 (p-STAT3), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), suppressor of cytokine signaling 3 (SOCS3) mRNA, and protein-tyrosine phosphatase 1B (PTP1B) mRNA, pro-opiomelanocortin (POMC) mRNA and neuropeptide Y (NPY) mRNA were measured by Western blot or qRT-PCR to evaluate the hypothalamic leptin sensitivity. Additionally, we measured the protein or mRNA levels of ${\alpha}7nAChR$, inhibitor of nuclear factor ${\kappa}B$ kinase subunit ${\beta}/nuclear$ factor ${\kappa}B$ ($IKK{\beta}/NF-KB$) and pro-inflammatory cytokines ($IL-1{\beta}$ and $TNF-{\alpha}$) in hypothalamus and adipose tissue to reflect the anti-inflammatory effects of As IV through upregulating expression of ${\alpha}7nAChR$. We found that As IV prevented body weight gain and adipose accumulation, and also improved metabolic disorders in HFD rats. Furthermore, As IV decreased BP and HR, as well as NE levels in blood and renal tissue. In the hypothalamus, As IV alleviated leptin resistance as evidenced by the increased p-STAT3, LepRb mRNA and POMC mRNA, and decreased p-PI3K, SOCS3 mRNA, and PTP1B mRNA. The effects of As IV on leptin sensitivity were related in part to the up-regulated ${\alpha}7nAchR$ and suppressed $IKK{\beta}/NF-KB$ signaling and pro-inflammatory cytokines in the hypothalamus and adipose tissue, since co-administration of ${\alpha}7nAChR$ selective antagonist ${\alpha}-BGT$ could weaken the improved effect of As IV on central leptin resistance. Our study suggested that As IV could efficiently prevent obesityassociated hypertension through inhibiting inflammatory reaction and improving leptin resistance; furthermore, these effects of As IV was partly related to the increased ${\alpha}7nAchR$ expression.

Syntaxonomy of the Forest Vegetation and Surrounding Taegu, Korea (대구 인접지역에 대한 삼림식생의 군락분류)

  • Choung, Heung-Lak;Lee, Ho-Joon;Lee, Jae-Seok
    • The Korean Journal of Ecology
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    • v.23 no.5
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    • pp.407-421
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    • 2000
  • The forest vegetation surrounding Taegu area was investigated by the methodology of the ZM school of phytosociology, from September, 1994 to August, 1997. The forest vegetation was classified into 7 communities, 8 subcommunities and 5 afforestations as follows : Quercus mongolica community (Typical subcommunity, Carex siderosticta subcommunity), Quercus variabilis community, Quercus acutissima community, Quercus dentate community, Carpinus cordata-Acer mono community (Typical subcommunity, Quercus serrata subcommunity, Cornus controversa subcommunity), Pinus densiflora community (Typical subcommunity, Sanguisorba officinalis subcommunity, Rhododendron schlippenbachii subcommunity), Lespedeza maximowiczii-Rhododendron mucronulatum community , Robinia pseudo-acacia afforestation, Pinus rigida afforestation, Larix leptolepis afforestation, Pinus thunbergii afforestation, Pinus koraiensis afforestation. The differential species of the Quercus mongolica community were Quercus mongolica, Athyrium yokoscense, Rhododendron schlippenbachii, Fraxinus sieboldiana, Acer pseudo-sieboldianum, Symplocos chinensis for. pilosa, Astilbe chinensis var. davidii, Weigela subsessilis, and Melampyrum roseum, those of the Carpinus cordata-Acer mono community were Acer mono, Carpinus cordata, Carpinus laxiflora, and Staphylea bumalda, those of the Pinus densiflora community were Pinus densiflora, Quercus serrata, Cocculus trilobus, and Juniperus rigida. Constance degree of the Quercus serrate was especially high in shrub and herb layers of the Pinus densiflora community. The results of factor analysis by DCA showed that distribution pattern of the communities were similar to that by Z-M method and that communities were arranged according to soil moisture gradient. Rhododendron schlippenbachii subcommunity of the P. densiflora community and the Typical subcommunity of the Q. mongolica community were distributed in similar environments.

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EXPRESSION OF DOMINANT NEGATIVE p63 ISOFORM IN WELL-DIFFERENCIATED ORAL SQUAMOUS CELL CARCINOMA (분화도 좋은 구강 편평상피세포암종에서 Dominant Negative p63 isoform의 발현)

  • Kim, In-Su;Kim, Chul-Hwan;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.3
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    • pp.191-198
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    • 2007
  • The p53 which is well known as tumor suppressor gene is located at 17p13. p53 is a sequence-specific DNA binding transcription factor that responds to certain cytotoxic stresses, such as DNA damage, by enhancing the transcription of genes that regulate cell-cycle progression as well as programmed cell death. The p63 gene that is located at 3q27-29, is recognized members of the p53 family, and responsible for the transcription of 6 isoforms. Three isoforms ($TAp63{\alpha}$, $TAp63{\beta}$, $TAp63{\gamma}$) contain an N-terminal transactivation (TA) domain and can induce apoptosis. The other 3 isoforms (${\Delta}Np63{\alpha}$, ${\Delta}Np63{\beta}$, ${\Delta}Np63{\gamma}$) lack the TA domain and may function in a dominant-negative fashion by inhibiting the transactivation functions of p53 and TAp63 proteins, and thus act as oncoproteins. A number of studies have investigated the role of p63 in human squamous cell carcinomas from different organs. Only a few studies have examined ${\Delta}Np63$ isoform in oral squamous cell carcinoma including normal epithelium. This study aimed to evaluate expression of ${\Delta}Np63$ isoform in human oral squamous cell carcinoma tissue and normal mucosa. The 3 cases of well differenciated oral squamous cell carcinoma specimen including adjacent normal mucosa were examined, and immunohistochemical study with monoclonal antibody(4A4) and tumor cell apoptosis analysis with Transmission Electon Microscopy were studied. And, RT-PCR analysis was done for expression of ${\Delta}Np63$ isoform. The results were as followed. 1. Normal gingiva showed the restricted p63 expression in basal cell layer. 2. Well differentiated squamous cell carcinoma showed mainly p63 expression in overall area of malignancy, especially in basal cell layer to adjacent stromal tissue. 3. Tumor cells around keratinized area with no p63 expression disclosed less micro-organelle in decreased size cytoplasm and severe chromatin margination with nuclear destruction that means apoptosis. 4. Comparison of mRNA expression of ${\Delta}Np63$ isoform by RT-PCR showed variable expression of ${\Delta}Np63$ isoform, but ${\Delta}Np63{\alpha}$ was most highly expressed in all 3 tumor specimen. From theses results, it should be suggested that ${\Delta}Np63$ isoform expression in well differentiated squamous cell carcinoma was closely related to tumor oncogenesis, expecially overexpression of ${\Delta}Np63{\alpha}$ is a most important factor in tumor genesis of oral squamous cell carcinoma.