• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.343-350
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• 2008

PD-L1 is expressed in a variety of antigen-presenting cells and provides T cell tolerance via ligation with its receptor PD-1 and B7-1 on T cells. Stimulation with lipopolysaccharide (LPS) can increase the level of PD-L1 expression in B cells and macrophages, which suggests that this molecule plays a role in the immunosuppression observed in severe sepsis. The aim of this study was to identify which of the downstream pathways of TLR4 are involved in the up-regulation of PD-L1 by LPS in macrophages. Flow cytometry was used to examine the expression of PD-L1 in RAW 264.7 macrophages stimulated with LPS. The following chemical inhibitors were used to evaluate the role of each pathway: LY294002 for PI3K/Akt, SB202190 for p38 MAPK, and U0126 for MEK. LPS induced the expression of PD-L1 in a time- and dose-dependent manner. Transfection of siRNA for TLR4 suppressed the induction of PD-L1. Pretreatment with LY294002 and SB202190 decreased the level of PD-L1 expression but U0126 did not. Overall, the PI3K/Akt and p38 MAPK pathways are involved in the up-regulation of PD-L1 expression in RAW 264.7 macrophages stimulated with LPS.

• Journal of the Mineralogical Society of Korea
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• v.8 no.1
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• pp.13-22
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• 1995

Phase relations of the Pd-Sb system were investigated using the sealed-capsule technique; the quenched run products were studied by reflected light microscopy, X-ray diffraction, and electron microprobe analysis. Eight binary phases were confirmed to exist in the system: Pd20Sb7, Pd31Sb12, Pd8Sb3 (mertieite II), Pd5Sb2, Pd2Sb, Pd5Sb3, PdSb (sudburyite), and PdSb2, (unnamed PdSb2), The X-ray powder diffraction data of all the phases, except for Pd5Sb3, however, may be indexable on an orthorhombic cell, space group Cmc2, with a=3.362(1), b=17.484(7), c=6.934(2)$\AA$. Some physical properties as well as re-determined cell parameters are newly established. A revised phase relations of the Pd-Sb system are presented.

• Journal of Hydrogen and New Energy
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• v.27 no.3
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• pp.264-269
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• 2016

A simple dry chemical approach was developed in order to load palladium (Pd) as a promoter on Pt/gas diffusion electrode (GDE) for polymer electrolyte membrane fuel cell (PEMFC). Palladium(II) bis (acetylacetonate), $Pd(acac)_2$ was sublimed, penetrated into Pt/GDE and then reduced to Pd nanoparticles simultaneously without any reducing agent and any solvent in a glass reactor of $N_2$ atmosphere at $180^{\circ}C$ for 3, 5 and 15 min. Pd distribution was analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), and I-V curve was estimated by using a unit cell with $5{\times}5cm^2$ active area.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.73-73
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• 2003

본 연구는 돼지 체세포의 clonal cell lines을 효율적으로 확립할 수 있는 배양방법을 제시하기 위하여 실시하였다. 50일령의 돼지태아로부터 섬유아세포를 회수하여 2회 계대배양 후 단일 세포를 96-well plate와 4-well dish에서 배양하여 배양액내의 FBS농도(10, 30, 50%), 첨가제(catalase, $\beta$-mercaptoethanol; BME), 세포의 크기(<16, 16~20, 20<) 및 형태(smooth, rough)에 따른 cell line 확립 효율을 검토하였다. FBS 농도에 따른 clonal line 확립 효율과 PD를 검토한 결과, 효율에 있어서 30% FBS 처리구(5.1%)가 10%(0.3%) 및 50%처리구(2.1%)보다 비교적 높게 나타났으나 유의적 차이는 없었으며, PD의 경우는 10, 30, 50%처리구에서 각각 36.7, 29.4, 26.3 시간으로 FBS 농도가 증가할수록 PD 시간이 유의적으로 짧아졌다(p<0.05). 배양액 첨가제에 있어서 BME 가시 무처리구나 catalase 첨가시보다 유의적으로 높은 효율을 보였으며(11.4%, 3.2%, 3.2%; p<0.05), PD 시간은 짧게 나타났다(23.6, 25.5, 28.1; p<0.05). 그러나 catalase는 cell line 확립 효율에 영향을 미치지 않는 것으로 나타났다. 세포의 크기에 따른 cell line 확립효율은 5.2~8.2%로 크기에 따른 차이는 보이지 않았으며, PD 또한 23.7~27.9 시간으로 세포 크기에 따른 차이는 없었다. 세포의 형태에 따른 세포의 부착율은 smooth(55.8%)구가 rough(73.0%)구보다 유의적으로 낮게 나타났으나(p<0.05), clonal line 확립 효율(7.7%n vs. 6.6%) 및 PD(23.5h vs. 24.0h)에서는 차이가 없었다. 본 연구의 결과, 세포의 형태에 따른 cell line 확립 효율은 큰 차이가 없었으나, 세포 배양액내에 30% FBS와 BME의 첨가로 clonal cell line 확립 효율을 향상시킬 수 있음을 확인할 수 있었다. 또한 cell line 확립 효율이 높아질수록 PD 시간이 짧아지는 경향을 볼 수 있었다.

• Animal Bioscience
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• v.36 no.5
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• pp.710-719
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• 2023

Objective: The present study investigated whether protodioscin (PD), a steroidal saponin mainly found in rhizome of Dioscorea species, alleviates oxidative stress-induced damage of porcine oocytes during in vitro maturation. Methods: Oocytes were treated with different concentrations of PD (0, 1, 10, 100, and 200 µM) in the presence of 200 µM H₂O₂ during in vitro maturation. Following maturation, spindle morphology and mitogen-activated protein kinase activity was assessed along with reactive oxygen species level, GSH activity, and mRNA expression of endogenous antioxidant genes at the MII stage. On the day 7 after parthenogenetic activation, blastocyst formation rate was calculated and the quality of embryo and mRNA expression of development-related genes was evaluated. Results: Developmental competence was significantly poorer in the 0 µM PD-treated (control) group than in the non-treated (normal) and 10 µM PD-treated (10PD) groups. Although the reactive oxygen species level did not significantly differ between these three groups, the glutathione level and mRNA expression of antioxidant genes (superoxide dismutase 1 [SOD1], SOD2, nuclear factor erythroid 2-related factor 2 [Nrf2], and hemo oxygenase-1 [HO-1]) were significantly higher in the normal and 10PD groups than in the control group. In addition, the percentage of oocytes with defective spindle and abnormal chromosomal alignment was significantly lower and the ratio of phosphorylated p44/42 to total p44/42 was significantly higher in the normal and 10PD groups than in the control group. The total cell number per blastocyst was significantly higher in the 10PD group than in the control group. The percentage of apoptotic cells in blastocysts was highest in the control group; however, the difference was not significant. mRNA expression of development-related genes (POU domain, class 5, transcription factor 1 [POU5F1], caudal type homeobox 2 [CDX2], Nanog homeobox [NANOG]) was consistently increased by addition of PD. Conclusion: The PD effectively improves the developmental competence and quality of blastocysts by protecting porcine oocytes against oxidative stress.

• IMMUNE NETWORK
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• v.20 no.1
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• pp.8.1-8.15
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• 2020

Immune checkpoint blockade targeting PD-1 and PD-L1 has resulted in unprecedented clinical benefit for cancer patients. Anti-PD-1/PD-L1 therapy has become the standard treatment for diverse cancer types as monotherapy or in combination with other anticancer therapies, and its indications are expanding. However, many patients do not benefit from anti-PD-1/PD-L1 therapy due to primary and/or acquired resistance, which is a major obstacle to broadening the clinical applicability of anti-PD-1/PD-L1 therapy. In addition, hyperprogressive disease, an acceleration of tumor growth following anti-PD-1/PD-L1 therapy, has been proposed as a new response pattern associated with deleterious prognosis. Anti-PD-1/PD-L1 therapy can also cause a unique pattern of adverse events termed immune-related adverse events, sometimes leading to treatment discontinuation and fatal outcomes. Investigations have been carried out to predict and monitor treatment outcomes using peripheral blood as an alternative to tissue biopsy. This review summarizes recent studies utilizing peripheral blood immune cells to predict various outcomes in cancer patients treated with anti-PD-1/PD-L1 therapy.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.2
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• pp.6-11
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• 2001

Abstract- In this paper, a new Partial Discharge (PD) detection using Pockels cell was proposed and considerable apparent chaotic characteristics were discussed. For this purpose, PD was generated from needle-plane electrode in air and detecte by optical measuring system using Pockels cell, based on Mach-Zehner interferometer, consisting of He-Ne laser, single mode optical fiber, 50/50 beam splitter and photo detector. In addition, the presence of chaos of the PD signals has been investigated by examining their means of qualitative and quantitative information. For the former, return map and 3-dimensional strange attractor have been drawn in order to investigate the presence of chaotic characteristics relevant to PD signals, detected through CT and Peckels sensor respectively, in the normalized time series. The presence of strange attractor indicates the existence of fractal structures in it's phase space. For the latter, several dimension values of strange attractor were verified sequentially. Throughout this paper, it is likely that the chaotic characteristics regarding the PD signals under air are verified.

• Journal of Hydrogen and New Energy
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• v.27 no.3
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• pp.270-275
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• 2016

A simple solid state incorporation method was employed in order to incorporate Pd nanocatalyst into a Nafion film for polymer electrolyte membrane fuel cell (PEMFC) via the reduction of palladium (II) bis (acetylacetonate), $Pd(acac)_2$. It was sublimed, penetrated into Nafion film and then reduced to Pd nanoparticles simultaneously in a glass reactor of N2 atmosphere at $180^{\circ}C$ for 1, 3 and 5 min. This reaction was took place without any reducing agent and any solvent. The morphology of the Pd nanoparticles was observed by transmission electron microscopy (TEM), and Pd distribution was analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). And 23% modification of tensile strength of Pd/Nafion composite film was measured by universal testing machine and I-V curve was estimated by using a unit cell with $5{\times}5cm^2$ active area.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.63-70
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• 2019

Myeloid-derived suppressor cells (MDSCs) that are able to suppress T cell function are a heterogeneous cell population frequently observed in cancer, infection, and autoimmune disease. Immune checkpoint molecules, such as programmed death 1 (PD-1) expressed on T cells and its ligand (PD-L1) expressed on tumor cells or antigen-presenting cells, have received extensive attention in the past decade due to the dramatic effects of their inhibitors in patients with various types of cancer. In the present study, we investigated the expression of PD-1 on MDSCs in bone marrow, spleen, and tumor tissue derived from breast tumor-bearing mice. Our studies demonstrate that PD-1 expression is markedly increased in tumor-infiltrating MDSCs compared to expression in bone marrow and spleens and that it can be induced by LPS that is able to mediate $NF-{\kappa}B$ signaling. Moreover, expression of PD-L1 and CD80 on $PD-1^+$ MDSCs was higher than on $PD-1^-$ MDSCs and proliferation of MDSCs in a tumor microenvironment was more strongly induced in $PD-1^+$ MDSCs than in $PD-1^-$ MDSCs. Although we could not characterize the inducer of PD-1 expression derived from cancer cells, our findings indicate that the study on the mechanism of PD-1 induction in MDSCs is important and necessary for the control of MDSC activity; our results suggest that $PD-1^+$ MDSCs in a tumor microenvironment may induce tumor development and relapse through the modulation of their proliferation and suppressive molecules.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.29-32
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• 2008

The cell performance of direct formic acid fuel cell (DFAFC) having catalysts coated by electrospray was analyzed. Pd catalyst was used for the anode electrode and Pd catalyst loading amount and formic acid feed rate dependances of fuel cell performance were evaluated. When loading amount of Pd is in between 3mg/$cm^2$ and 7mg/$cm^2$ and formic acid feed rate is 5ml/min., 3mg/$cm^2$ sample showed better potential at 129 mA/$cm^2$ and power density due to difference in mass transfer limitation. However, when the feed rate is greater than 10ml/min., the opposite tendency was observed between 3mg/$cm^2$ and 7mg/$cm^2$ samples. The result was attributed to improvement in electrochemical reaction of the Pd. Based on the above results, In DFAFC including Pd catalyst that was coated by electrospray, 0.537V as the maximum potential at 129 mA/$cm^2$ was attained.