• Title, Summary, Keyword: X7R

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A Roentgenographic Study on the Development of Human Permanent Posterior Teeth (영구 구치 발육에 관한 방사선학적 연구)

  • Young-Ku Kim
    • Journal of Oral Medicine and Pain
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    • v.16 no.1
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    • pp.73-84
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    • 1991
  • 저자는 연령을 추정하기 위한 기본자료를 얻기 위하여 상하악의 대구치, 소구치의 발육정도를 평가하였다. Orthopantomograph를 촬영한 722명의 3,464개 치아를 대상으로 crown-root ratio를 측정하여 발육정도를 평가하였으며, 다음과 같은 결론을 얻었다. 1. 완전히 형성된 치아의 crown-root ration에는 남녀간에 유의한 차이가 없었다. 2. 발육중인 치아의 crown-root ratio에는 좌우측간에 유의한 차이가 없었다. 3. 각 치아의 crown-root ratio를 이용한 연령추정의 회귀방정식은 다음과 같다. 남자: 여자 : 하악좌측 제 2대구치 : Y=4.599X+7.832(r=0.8337) 하악 좌측 제 2대구치 : Y=4.857X+7.429(r=0.8975) 제 1대구치 : Y=5.179X+2.324(r=0.7948) 제 1대구치 : Y=5.919X+2.018(r=0.8144) 제 2소구치 : Y=3.863X+7.432(r=0.8638) 제 2소구치 : Y=3.679X+7.275(r=0.8819) 제 1소구치 : Y=3.472X+7.120(r=0.8352) 제 1소구치 : Y=4.001X+6.544(r=0.9024) 하악우측 제 2대구치 : Y=4.447X+7.938(r=0.8045) 하악 우측 제 2대구치 : Y=4.653X+7.365(r=0.8598) 제 1대구치 : Y=5.954X+1.495(r=0.7777) 제 1대구치 : Y=5.449X+2.012(r=0.7553) 제 2소구치 : Y=3.894X+7.253(r=0.8689) 제 2소구치 : Y=3.772X+7.025(r=0.8719) 제 1소구치 : Y=4.189X+6.717(r=0.8370) 제 1소구치 : Y=4.327X+6.193(r=0.8524) 상악좌측 제 2대구치 : Y=4.430X+7.722(r=0.7538) 상악 좌측 제 2대구치 : Y=4.876X+7.606(r=0.8311) 제 1대구치 : Y=4.645X+2.886(r=0.6894) 제 1대구치 : Y=6.754X+1.891(r=0.5378) 제 2소구치 : Y=4.391X+6.686(r=0.7700) 제 2소구치 : Y=1.245X+10.575(r=0.1908) 제 1소구치 : Y=5.564X+6.037(r=0.9032) 제 1소구치 : - 상악우측 제 2대구치 : Y=4.587X+7.966(r=0.7882) 상악 우측 제 2대구치 : Y=4.454X+7.803(r=0.8443) 제 1대구치 : Y=4.047X+4.124(r=0.6352) 제 1대구치 : Y=6.336X+2.911(r=0.4688) 제 2소구치 : Y=2.920X+8.089(r=0.7277) 제 2소구치 : Y=3.105X+8.082(r=0.6381) 제 1소구치 : Y=3.264X+6.970(r=0.7292) 제 1소구치 : - 4. Orthopantomograph상의 crown-root ratio를 이용한 연령의 추정에는 상악치아들 보다 하악치아들이 더 정확하게 사용될 수 있다.

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Effects of Additives on Dielectric Properties and Microstructure of MLCC X7R Composition (첨가물의 형태가 MLCC X7R 조성의 유전 특성 및 미세구조에 미치는 영향)

  • Moon, Hwan;Kim, Min-Kee;Jeon, Hyun-Pyo;Ahn, Jae-Pyoung;Yoon, Jung-Rag;Chung, Tae-Serk
    • Journal of the Korean Ceramic Society
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    • v.40 no.7
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    • pp.644-651
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    • 2003
  • Effects of additives on electrical properties and microstructure of MLCC X7R dielectrics have been investigated. The additives of glass frit or oxide form were added in the same main composition by the different powder processing conditions. As a result of the dielectric property and microstructure analysis, the composition having the glass layer with dopant concentration gradient showed the excellent dielectric properties. The MLCCs were fabricated with the excellent composition and all dielectric properties satisfied the X7R requirements.

Dielectric Properties of Non-reducible X7R Dielectric Materials in $BaTiO_3$-$Er_2$$O_3$--MgO ($BaTiO_3$-$Er_2$$O_3$-MgO 첨가계를 이용한 내환원성 X7R 재질의 유전특성에 관한 연구)

  • 한영호;최상근;황진현
    • Journal of the Korean Ceramic Society
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    • v.38 no.7
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    • pp.615-620
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    • 2001
  • E $r_2$ $O_3$-MgO 복합 첨가가 BaTi $O_3$계 내환원성 X7R 재질의 유전특성에 미치는 영향에 대하여 환원성 분위기에서 연구하였다. (B $a_{1-x}$ E $r_{x}$)( $Ti_{1-y}$M $g_{y}$ ) $O_3$첨가계에서 1.0 mol% 이상 MgO의 복합첨가로 E $r_{Ba}$ 도너 불순물과 $Mg_{Ti}$ 억셉터 불순물이 전기적으로 보상되어, 환원성분위기 소결 후에도 $10^{10}$Ωcm 이상의 높은 절연저항을 나타내었다. E $r_2$ $O_3$가 첨가된 시편에서 MgO가 2.0 mol% 이상 첨가될 경우, 유전율의 온도안정성이 향상되어 X7R 규격을 만족시켰으며 1.0$mu extrm{m}$ 이하의 작고 균일한 입자가 관찰되었다. 한편, E $r_2$ $O_3$의 첨가량이 3.0 mol%로 증가함에 따라 유전율의 온도안정성이 향상되었으나 상대적으로 상온 유전상수값이 현저히 감소하였다.였다.다.

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Syntheses and Characteristics of R-P Phase $Ln_{1-x}Sr_{2-x}Mn_2O_7$(Ln=La, Pr, Gd, Eu, Er, Nd, Sm) (R-P Phase $Ln_{1-x}Sr_{2-x}Mn_2O_7$(Ln=La, Pr, Gd, Eu, Er, Nd, Sm)의 합성 및 특성연구)

  • 송민석;서상일;이재열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.337-340
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    • 1999
  • Since the first reports of CMR(colossal magnetoresistance) effects in some single crystal R-P Phase Ln$_{1-x}$ Sr$_{2-x}$Mn$_{2}$O$_{7}$ 1996. many researches have been carried out to find optimum compositions and processing conditions in this system. In this study, layered perovskite R-P Phase Ln$_{1-x}$ Sr$_{2-x}$Mn$_{2}$O$_{7}$ (x=0.4, Ln=-La, Eu, Gd, Nd, Pr, Sm) phases were synthesized by solid state reaction and their structures were refined by Rietveld method. Electrical and magnetic properties were measured drown to 20K and compare with those of R-P Phase Ln$_{1-x}$ Sr$_{2-x}$Mn$_{2}$O$_{7}$ Phases.es.es.es.es.es.

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Prediction of Physical Properties in the Design of Mono-Acetate Filter Cigarette by Response Surface Methodology (반응표면 실험 계획법에 의한 Mono-Acetate 필터담배 설계의 물리성 예측)

  • 김영호;이영택;김성한;김윤동;임광수;김용태
    • Journal of the Korean Society of Tobacco Science
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    • v.16 no.1
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    • pp.3-13
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    • 1994
  • To minimize the time ordinarily spent in mono filter cigarette design, we studied the relationship between major seven independant variables ; filament(X1) and total denier(X2), porosity of the aller plug wrap(X3), filter length(X4), Porosity of the tip paper(X5) and cigarette paper(X6) and net weight of the reference cut tobacco(X7). Ninty trial numbers were obtained as a results of using rotatable central composite design and it is analyzed by the multiple regression analysis with stepwise in SAS/pc under restricted conditions. That is, UPD (Y1) = 82.96 - 3.80X1 + 2.50X2 - 3.29X3 - 3.15X5 - 0.83X22 + 1.88X5X6 - 1.38 X5X7(R2: 0.63), EPD(Y2) : 120.91 - 5.70X1 + 3.60X2 + 4.23X4 - 0.93X6 + 4.06X7 (R2=0.84), TVR(Y3) = 49.70 - 0.78X1 + 3.60X3 + 2.00X4 + 4.20X5 - 0.93X6 + 2.64X7 - 1.07X1X2 + 1.0IX1 X3 + 1.05X2X6 + 0.45X22 - 0.64X42 + 1.29X4X6 - 0.97X4X7 - 1.28X5X6 + 1.53X5X7 + 1.39X6X7(R2=0.65), and EVR(Y4) : 3.24-0.21X3-0.20X4 -0.24X5+0.67X6+0.26X4X7 (R2=0.55), where EPD : encapsulated pressure drop, VPD : unencapsulated pressure drop, TVR ; tip ventilation rate, and En : envelope ventilation rate. All variables in the model are significant at the 0.05 level.

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A Cross-sectional Survey on Drug Abuse among High School Students in Taegu City (대구시내 고등학생의 약물남용에 관한 연구)

  • Lee, Hyun-Sook;Kim, Chung-Nam;Oh, Yun-Jung
    • Journal of Korean Academy of Community Health Nursing
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    • v.8 no.2
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    • pp.347-367
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    • 1997
  • The purpose of this study was to investigate drug abuse and to find related factors among high school students. The subjects for this study were 973 students from 10 high schools in Taegu city. The data were collected from September 30, 1996 to October 30, 1996. The questionnaire developed by Kim Soyoaja (1991) surveyed adolescent drug use and questions on smoking and drinking were readjusted and added by the researcher based on review. The data was analyzed using frequency, percentage, $X^2-test$, t -test, Pearson Correlation Coefficient with the SPSS /PC+. The results of this study were summarized as follows: 1. The proportion of students who drank alcohol 1-2 times or more per year was 52.4% and smoked Cigarette 1 -2 times or more per year was 20.8%. The 7 different drugs(Analgetics 5.7%. sleeping pills and sedatives 4.2%, antihistamines 1.1%. stimulants 7.7%, hallucinogens 0.8%, inhalants 3.3%, and narcotics 0.6%) were also evaluated. 2. There was a significant relationship between drinking and type of school($X^2$=62.97, p<.0l), grades($X^2$=33.86, P<.001), school life($X^2$= 19.04, p<.001), and delinquent friends($X^2$= 64.72, P<.001). 3. There was a significant relationship between smoking and type of school($X^2$=153.65, p<.001), grades ($X^2$=67.53, p<.001), their respect for teachers ($X^2$=33.80, p<.001) school life($X^2$ =50.87, p<.001), and delinquent friends($X^2$ =85.28, p<.001). 4. There was a significant relationship between the 7 different kinds of drug abuse and type of school ($X^2$=14.65, p<.01), grades($X^2$=12.89, p<.01), their respect for teachers ($X^2$=8.46, p<.05), and delinquent friends($X^2$=22.42, p<.001). 5. There was a significant relationship between a parent's habitual drug abuse and the 7 different kinds of drug abuse($X^2$=7.78, p<.01), as well as a parent's attitude toward drugs and the 7 different kinds of drug abuse($X^2$=6.33, p<.05). 6. There was a significant difference between drinking(t=-12.53, p<.001), smoking(t=-15.98, p<.001), the 7 different kinds of drug abuse(t=-5.77, p<.001), and the respondant's delinquent experience. 7. There was a correlation between drinking and smoking(r=.4166, p<.001), drinking and the 7 different kinds of drug abuse(r=.2200, p<.001), smoking and the 7 different kinds of drug abuse(r=.1428, p<.05). There was a correlation between drinking and smoking(r=.5977, p<.001), drinking and the 7 different kinds of drug abuse(r=.2849, p<. 001), smoking and the 7 different kinds of drug abuse(r=.1711, p<.05) among male students. There was a correlation between drinking and smoking(r=.4219, p<.001), drinking and the 7 different kinds of drug abuse(r=.2611, p<.001), smoking and the 7 different kinds of drug abuse(r=.1764, p<.001) among female students. 8. There was a correlation between drinking and family stability(r=.0709, p<.05) drinkry and parent -child relationships (r=.1321, p<.01), drinking and mother's rearing attitude(r=.0704, P<.05), smoking and parent -child relationships(r=.0813, P<.05). There was a correlation between drinking and family stability(r=.14S7, p<.01), drinkng and parent-child relationships(r=.2147, p<.001), smoking and family stability(r=.1544, p<.01), smoking and parent. -child relationships (r=. 2018, P<.01) among male students. There was a correlation between drinking and family stability(r=.1l21, p<.05), drinking and mother's rearing attitude (r=.0988, P<.05), smoking and parent -child relationships (r=. 0940, P<.05) among female students. 9. There was a significant difference between the 7 different kinds of drug abuse and family stability (t=2.23, p<.05), parent-child relationships (t=4. 34, p<.001), satisfaction with family (t=4.02, p<.001), father's rearing attitude(t=3.04, p<.01), mother's rearing attitude(t=2.87, p<.01). The distribution channel of drugs including alcohol beverages and cigarettes should be evaluated and restructured to discourage student's temptation and to limit accessibility. The step by step preventive teaching on alcohol drinking and cigarette smoking is needed from middle school to help prevent further drug abuse.

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Adipose-Derived Stem Cells Suppress Inflammation Induced by IL-1β through Down-Regulation of P2X7R Mediated by miR-373 in Chondrocytes of Osteoarthritis

  • Jin, Rilong;Shen, Miaoda;Yu, Liedao;Wang, Xuanwei;Lin, Xiangjin
    • Molecules and Cells
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    • v.40 no.3
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    • pp.222-229
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    • 2017
  • Adipose-derived stem cells (ADSCs) were previously considered to have an anti-inflammatory effect, and Interleukin-$1{\beta}$ ($IL-1{\beta}$) was found to be a pro-inflammatory factor in chondrocytes, but the mechanism underlying ADSCs and $IL-1{\beta}$ is unclear. In this study, we investigate whether P2X7 receptor (P2X7R) signalling, regulated by microRNA 373 (miR-373), was involved in the ADSCs and $IL-1{\beta}$ mediated inflammation in osteoarthritis (OA). Chondrocytes were collected from 20 OA patients and 20 control participants, and ADSCs were collected from patients who had undergone abdominal surgery. The typical surface molecules of ASDCs were detected by flow cytometry. The level of nitric oxide (NO) was determined by Griess reagent. Concentrations of prostaglandin E2 (PGE2), interleukin 6 (IL-6), matrix metallopeptidase 3 (MMP-3) were detected by enzyme-linked immunosorbent assay (ELISA). The expressions of IL-6, MMP-3, miR-373 and P2X7R were determined by real-time polymerase chain reaction (PCR), and Western blot was used to detect the protein expression of P2X7R. The typical potential characters of ADSCs were verified. In chondrocytes or OA tissues, the miR-373 expression level was decreased, but the P2X7R expression was increased. $IL-1{\beta}$ stimulation increased the level of inflammatory factors in OA chondrocytes, and ADSCs co-cultured with $IL-1{\beta}$-stimulated chondrocytes decreased the inflammation. OA chondrocytes transfected with the miR-373 inhibitor increased the inflammation level. The miR-373 mimic suppressed the inflammation by targeting P2X7R and regulated its expression, while its effect was reversed by overexpression of P2X7R. $IL-1{\beta}$ induced inflammation in OA chondrocytes, while ADSCs seemed to inhibit the expression of P2X7R that was regulated by miR-373 and involved in the anti-inflammatory process in OA.

A study on the Degradation and By-products Formation of NDMA by the Photolysis with UV: Setup of Reaction Models and Assessment of Decomposition Characteristics by the Statistical Design of Experiment (DOE) based on the Box-Behnken Technique (UV 공정을 이용한 N-Nitrosodimethylamine (NDMA) 광분해 및 부산물 생성에 관한 연구: 박스-벤켄법 실험계획법을 이용한 통계학적 분해특성평가 및 반응모델 수립)

  • Chang, Soon-Woong;Lee, Si-Jin;Cho, Il-Hyoung
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.1
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    • pp.33-46
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    • 2010
  • We investigated and estimated at the characteristics of decomposition and by-products of N-Nitrosodimethylamine (NDMA) using a design of experiment (DOE) based on the Box-Behken design in an UV process, and also the main factors (variables) with UV intensity($X_2$) (range: $1.5{\sim}4.5\;mW/cm^2$), NDMA concentration ($X_2$) (range: 100~300 uM) and pH ($X_2$) (rang: 3~9) which consisted of 3 levels in each factor and 4 responses ($Y_1$ (% of NDMA removal), $Y_2$ (dimethylamine (DMA) reformation (uM)), $Y_3$ (dimethylformamide (DMF) reformation (uM), $Y_4$ ($NO_2$-N reformation (uM)) were set up to estimate the prediction model and the optimization conditions. The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were $Y_1$ [% of NDMA removal] = $117+21X_1-0.3X_2-17.2X_3+{2.43X_1}^2+{0.001X_2}^2+{3.2X_3}^2-0.08X_1X_2-1.6X_1X_3-0.05X_2X_3$ ($R^2$= 96%, Adjusted $R^2$ = 88%) and 99.3% ($X_1:\;4.5\;mW/cm^2$, $X_2:\;190\;uM$, $X_3:\;3.2$), $Y_2$ [DMA conc] = $-101+18.5X_1+0.4X_2+21X_3-{3.3X_1}^2-{0.01X_2}^2-{1.5X_3}^2-0.01X_1X_2+0.07X_1X_3-0.01X_2X_3$ ($R^2$= 99.4%, 수정 $R^2$ = 95.7%) and 35.2 uM ($X_1$: 3 $mW/cm^2$, $X_2$: 220 uM, $X_3$: 6.3), $Y_3$ [DMF conc] = $-6.2+0.2X_1+0.02X_2+2X_3-0.26X_1^2-0.01X_2^2-0.2X_3^2-0.004X_1X_2+0.1X_1X_3-0.02X_2X_3$ ($R^2$= 98%, Adjusted $R^2$ = 94.4%) and 3.7 uM ($X_1:\;4.5\;$mW/cm^2$, $X_2:\;290\;uM$, $X_3:\;6.2$) and $Y_4$ [$NO_2$-N conc] = $-25+12.2X_1+0.15X_2+7.8X_3+{1.1X_1}^2+{0.001X_2}^2-{0.34X_3}^2+0.01X_1X_2+0.08X_1X_3-3.4X_2X_3$ ($R^2$= 98.5%, Adjusted $R^2$ = 95.7%) and 74.5 uM ($X_1:\;4.5\;mW/cm^2$, $X_2:\;220\;uM$, $X_3:\;3.1$). This study has demonstrated that the response surface methodology and the Box-Behnken statistical experiment design can provide statistically reliable results for decomposition and by-products of NDMA by the UV photolysis and also for determination of optimum conditions. Predictions obtained from the response functions were in good agreement with the experimental results indicating the reliability of the methodology used.

Effect of Soil Physical Characteristics on Rhizome Rot Incidence of Platycodon grangiflorus (토양 물리적특성이 도라지 근경부패병에 미치는 영향)

  • Lee, Young-Han;Choi, Yong-Jo;Park, Sang-Ryeol;Kim, Min-Keun;Cho, Soo-Jeong;Yun, Han-Dae
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.1
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    • pp.24-31
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    • 2000
  • This study was conducted to determine the effect of soil physical characteristics on rhizome rot incidence of platycodon. Sampling sites were Keochang 4, Kimhae 7, Haman 6, Chinju 6 and Koseong 3 fields in Kyongnam province and Hongcheon 6 fields in Kangwon province. The root disease incidence rate was correlated with soil depth Y=-0.747X+88.19($R^2=0.394^{***}$), soil hardness Y=4.36X+8.93($R^2=0.201^*$), bulk density Y=104.7X-80.99($R^2=0.295^{**}$), clay content Y=1.24X+14.14($R^2=0.196^*$), porosity Y=-3.11X+215.9($R^2=0.220^*$) and silt content Y=-0.75X+67.85($R^2=0.178^*$). The yield was correlated with soil depth Y=0.263X+0.971($R^2=0.105^*$), clay content Y=-0.688X+32.74($R^2=0.158^*$), porosity Y=1.974X-93.19($R^2=0.231^{**}$) and silt content Y=53.05X-108.65($R^2=0.232^*$), The optimum cultivated land of perennial platycodon was soil depth over 1m, soil hardness under $5kg\;cm^{-2}$, bulk density $1.0Mg\;m^{-3}$, moisture content 13~17%. clay content 5~10%, porosity 58~63%, silt content 38~64% and soil texture of silt loam.

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Expression of the ATP-gated $P2X_7$ Receptor on M Cells and Its Modulating Role in the Mucosal Immune Environment

  • Kim, Sae-Hae;Lee, Ha-Yan;Jang, Yong-Suk
    • IMMUNE NETWORK
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    • v.15 no.1
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    • pp.44-49
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    • 2015
  • Interactions between microbes and epithelial cells in the gastrointestinal tract are closely associated with regulation of intestinal mucosal immune responses. Recent studies have highlighted the modulation of mucosal immunity by microbe-derived molecules such as ATP and short-chain fatty acids. In this study, we undertook to characterize the expression of the ATP-gated $P2X_7$ receptor ($P2X_7R$) on M cells and its role in gastrointestinal mucosal immune regulation because it was poorly characterized in Peyer's patches, although purinergic signaling via $P2X_7R$ and luminal ATP have been considered to play an important role in the gastrointestinal tract. Here, we present the first report on the expression of $P2X_7R$ on M cells and characterize the role of $P2X_7R$ in immune enhancement by ATP or LL-37.