Signal transduction of 4-1BB for CD8+ T cell survival

Pakr, SJ,Choi, BK,Kim, HH,Nam, KO,Kwon, BS,Lee, HW 이화여자대학교 세포신호전달연구센터 2002 고사리 세포신호전달 심포지움 Vol. No.4

Engagement of two signals, T cell receptor(TCR) and co-stimulatory molecule, are necessary for proper activation of T cells. Co-stimulatory signals in T cell are provided by the corresponding ligands on antigen presenting cells(APC). TCR signal alone leads to T cell anergy. 4-1BB, one of co-stimulatory molecules, is a member of TNF receptor superfamily and expressed on T cells upon TCR ligation. It is well known that 4-1BB is co-stimulatory molecule enhancing proliferation and inhibiting activation-induced cell death(AICD) of T cells. Moreover, 4-1BB has been appreciated as a critical molecule for enhancing immune rejection in allograft transplantation, eradication of tumor, integrin-mediated T cell adhesion, and T cell-mediated cytolysis. It is reported that 4-1BB-mediated co-stimulation is involved in responses of CD4+ and CD8+ T cell To elucidate molecular mechanisms by which 4-1BB enhances proliferation and survival of T cells, we purified CD8+ T cells and investigated the effect of 4-1BB on T cell activation. 4-1BB stimulation increased proliferation and survival of CD8+ T cells. 4-1BB-mediated proliferation was inhibited by pharmacological blockers for NF B and PI3-kinase(PDTC and LY294002, respectively). 4-1BB stimulation up-regulated expression of anti-apoptotic gene, Bcl-X_(L) mRNA and protein, and the effect of 4-1BB on Bcl-X_(L) was blocked by NF B inhibitor, but not by PI3-kinase inhibitor. Beads conjugated with anti-CD3 plus anti-4-1BB antibody induced raft formation at the site where T cells contacts to beads, suggesting 4-1BB ligation recruits signaling molecules such as PKC and IKK to initiate T cell signaling. 4-1BB induced NF B activation as shown by I B degradation, whereas it did not increase phosphorylation of Akt, downstream kinase activated by PI-3 kinase. These data suggest that 4-1BB ligation activates signaling events in raft which results in CD8+ T cell activation. 4-1BB-evoked NF B activation may be responsible for up-regulation of Bcl-X_(L) expression, which could be one of mechanisms by which 4-1BB enhances survival and proliferation of T cells.

The Effect of Phosphate Treatment on Nickel Dispersion on MCM-41 Mesoporous Material

Pakr, Sung Soo,Choe, Sang Joon,Park, Dong Ho 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.2

The incorporation of nickel into mesoporous molecular sieves MCM-41 was carried out. Ni-PO/MCM41 and Ni-CI/ MCM41 were prepared by using Ni(Ⅱ) acetate solution adjusted to pH=2.5 with phosphoric acid and hydrochloric acid, respectively, by the incipient wetness method. Photoacoustic spectroscopy(PAS) was used to study the local environments of Ni(Ⅱ) incorporate into mesopores. The PAS of as-prepared Ni/MCM41, Ni-CI/MCM41, and Ni-PO/MCM41 with Ni(Ⅱ) acetate solution exhibits two bands of λ_max around 400nm and 750nm, which could be assigned to the ^2A_2g → ^3T_1g(F) and the ^3A_2g → ^3T1g(P) transition of octahedral Ni(Ⅱ) species. After calcination, Ni ion within Ni-PO/MCM41 dispersed atomically onto the surface of MCM-41 channel as an octahedral species without the transformation to nickel oxide phase, while Ni ion within Ni-CI/MCM41 and Ni/MCM41 transformed to nickel oxide phase. It may be attributed to the fact that each Ni ion is separated by the phosphate grafted to surface silanol group. The effects of phosphoric acid on the dispersity of Ni ion within MCM-41 have been investigated using ^31P and ^29Si MAS NMR spectroscopy and X-ray photoelectron spectrosecopy.

Traditional Korean Medicine in the US: Public Attitude and Utilization

Pakr, Jung-Wee 인제대학교 1998 仁濟論叢 Vol.14 No.1

This paper examines the public's utilization of, and attitude towards, Korean traditional medicine, also known as hanbang, in the United States. This study relies on information given by 134 clients of Korean acupuncturists in New York. Results show that an increasing number of Americans utilize hanbang although their attitude appears quite different from that of Korean immigrants. Americans visit Korean traditional medical clinics either out of desperation or curiosity while Korean immigrants use hanbang out of a true belief in its effectiveness. Thus, most American patients tend to use this Korean alternative treatment only as a last resort. That is not always the case for Koreans who also receive a sort of cultural healing from their indigenous healers: Korean emigrants, especially the elderly who suffer from various migration related mental and physical maladies, prefer to seek help from compatriot hanbang practitioners. This paper also examines the impact of other socio-demographic variables, such as age, income, education, and medical insurance status. It is worth noting that the coverage of medical insurance plays an important role in the public's use of traditional Korean medicine.

단순지지구조 농업용수로교 거동분석을 통한 강재판받침장치의 개선방안에 대한 고찰 (부제 : 단순지지형식의 농업용수로교 강재판받침장치의 한계거동에 대한 연구)

박병진(Pakr, Byung Jin),마호성(Mha, Ho Seong),김재형(Kim, Jae Hyeong),김상욱(Kim, Sang Wook) 한국강구조학회 2023 한국강구조학회 학술대회 발표집 Vol.34 No.6

정부혁신에 내재화된 한국병의 진단과 처방

박우순(Pakr Woo-Soon) 서울행정학회 1998 한국사회와 행정연구 Vol.9 No.1

Surface Area of Char from Sewage Sludge

Min Pakr,Tanveer Ahmad,Sang-Sup Lee 한국폐기물자원순환학회 2015 한국폐기물자원순환학회 학술대회 Vol.2015 No.05

Experimental studies were carried out on surface area of char during pyrolysis of sewage sludge. To evaluate surface area of resultant char we use iodine number. Increase of iodine number shows that the surface area of char increases. The process parameters, temperature and holding time have significant effect on surface area of char. Increasing temperature above 400℃ surface area of char decreases while slightly increasing when holding time increases. In this study, the optimum conditions for high surface area of resultant char were found 400℃ and 30minutes, respectively.

사회과에서 사고력의 의미와 향상 방안

박형준(Pakr, Hyoung-joon) 성신여자대학교 교육문제연구소 2004 교육연구 Vol.38 No.-

본 논문에서는 사회과 교육의 다양한 맥락 속에서 사고력의 의미를 생각해 보았다. 또한 사회과 교육의 목적인 민주 시민성과 민주주의 이상을 실질적으로 구현시키기 위해서는 기존의 지식이나 가치 체계를 그대로 전수하거나 학습하기보다 이에 대해 문제 의식을 갖고 비판적으로 검토하며 해결책을 찾기 위해 적극적으로 노력하는 사고 활동이 더욱 강조되어야 한다고 주장하였다. 아울러 이런 사고 활동이 발현될 수 있기 위해서 사회과 교실이 어떻게 변해야 하는지도 제안해 보았다. The purposes of this study are to search for the meanings of thinking in the context of the social studies and to propose the conditions for the promotion of thinking. We reviewed the meanings of thinking in the various contexts of the social studies, that is, citizenship transmission, social science, reflective inquiry, informed social criticism, and personal development. And then, it was strongly argued that the social studies for the social transformation is required to essentially realize the idea of democratic citizenship which has been the core of the social studies education. In this point of view, special attention should be given to the reflective thinking and the critical thinking for social transformation. Lastly, we examined the conditions for social studies classrooms in which critical thinking for social transformation can be encouraged and activated.

센서 네트워크용 소형 섹터 안테나에 관한 연구

박주덕(Pakr Ju Derk),이강우(Lee Kang Woo),김내수(Kim Nae Soo),표철식(Pyo Cheol Sig) 한국통신학회 2010 한국통신학회 학술대회논문집 Vol.2010 No.6

건설기계 시공능력 산정에 관한 연구 : 작업효율 중심으로

박희성(Pakr Hee-Sung),한예령(Han Ye Lyeong),허영기(Huh Youngki),안방률(Ahn Bang Ryul) 대한토목학회 2008 대한토목학회논문집 D Vol.28 No.1D

건설기계는 건설사업의 성공적인 수행을 위한 중요한 요인이다. 그리고 건설기계에 소요되는 비용이 건설공사비에서 차지하는 비중이 크다. 따라서 건설기계 비용의 산정은 건설계획 단계에서 중요한 업무이다. 이를 위해서 우리나라는 표준 품셈에 제시된 건설기계 시공능력 산정식을 이용하여 건설기계의 시간당 작업량을 계산하는 방식을 활용하고 있다. 그러나 건설기계의 성능은 개선되고 있으나 시공능력 산정식에서 활용되고 있는 작업효율은 이를 반영하지 못하는 실정이다. 이에 본 연구는 유압식 백호, 로우더, 덤프트럭을 대상으로 현장실사를 통해 작업효율을 실측하였다. 그 결과 백호와 로우더는 현재 활용중인 작업효율보다 현장실사 값이 높게 나타났으며, 텀프트럭은 낮게 나타났다. 본 연구결과를 바탕으로 건설기계의 작업효율 표준 산정식에 대한 정의가 수립되어야 하며, 체계적이고 장기적인 조사를 거쳐 작업효율의 개정이 필요할 것으로 사료된다. Heavy equipment is a very important factor for successful construction implementation. Also, the cost for heavy equipment is a major part of construction cost. Therefore, the estimation of equipment cost is a critical job in the construction planning phase. A formula for production rates shown in 'Standard Unit Labor' has been used to estimate construction equipment capability per hour and cost. Although the performance of equipment has been improved, the efficiency rates in the formula are not updated lately. Therefore, this research performed several site visits to measure construction equipment working time and then calculates the efficiency rates for hydraulic backhoe, loader, and dump truck. The results show that the measured efficiencies of backhoe and loader are higher than current ones and vice versa for dump truck. This research proposes the needs for a standardized calculation formula and systematic and long-term data collection and measurement for updating efficiency rates for heavy equipment.

Surface Area of Char from Sewage Sludge

( Min Pakr ),( Tanveer Ahmad ),( Sang-sup Lee ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2015 No.-

Experimental studies were carried out on surface area of char during pyrolysis of sewage sludge. To evaluate surface area of resultant char we use iodine number. Increase of iodine number shows that the surface area of char increases. The process parameters, temperature and holding time have significant effect on surface area of char. Increasing temperature above 400℃ surface area of char decreases while slightly increasing when holding time increases. In this study, the optimum conditions for high surface area of resultant char were found 400℃ and 30minutes, respectively.