• Journal of Veterinary Science
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• 제22권5호
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• pp.75.1-75.10
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• 2021

Background: Programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) have important roles in tumor evasion of the immune system. Objectives: This study aimed to assess the diagnostic utility of circulating PD-1 and PD-L1 levels in healthy dogs and dogs with tumors. Methods: Circulating PD-1 and PD-L1 levels in the serum of 71 dogs with tumors were compared with those of 52 healthy dogs by performing enzyme-linked immunosorbent assay (ELISA). Results: The ELISA results revealed higher circulating PD-1 and PD-L1 levels in dogs with tumors (2.9 [2.2-3.7] ng/mL; median [IQR] and 2.4 [1.4-4.4] ng/mL, respectively) than in healthy dogs (2.4 [1.9-3.0] ng/mL; p = 0.012 and 1.4 [0.9-2.1] ng/mL; p < 0.001, respectively). Especially, there was a significant difference in circulating PD-1 levels between healthy dogs and dogs with malignant epithelial tumors (2.4 [1.9-3.0] ng/mL and 3.1 [2.6-4.4] ng/mL, respectively; p < 0.01). In addition, there was a significant difference in circulating PD-L1 levels between healthy dogs and dogs with lymphomas (1.4 [0.9-2.1] ng/mL and 2.7 [1.6-5.8] ng/mL, respectively; p < 0.001). Conclusion: This study indicates that circulating PD-1 and PD-L1 have potential as tumor diagnostic biomarkers in dogs with tumors.

• 센서학회지
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• 제15권2호
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• pp.120-126
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• 2006

Physicochemical and electrical properties for hydrogen gas sensors based on Pd-deposited $WO_3$ thin films were investigated as a function of Pd thickness, annealing temperature, and operating temperature. $WO_3$ thin films were deposited on an insulating material by thermal evaporator. XRD, FE-SEM, AFM, and XPS were used to evaluate the crystal structure, microstructure, surface roughness, and chemical property, respectively. The deposited films were grown $WO_3$ polycrystalline with rhombohedral structure after annealing at $500^{\circ}C$. The addition effect of Pd is not the crystallinity but the suppression of grain growth of $WO_3$. Pd was scattered an isolated small spherical grain on $WO_3$ thin film after annealing at $500^{\circ}C$ and it was agglomerated as an irregular large grain or diffused into $WO_3$ after annealing at $600^{\circ}C$. 2 nm Pd-deposited $WO_3$ thin films operated at $250^{\circ}C$ showed good response and recovery property.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권5호
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• pp.198-205
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• 2005

Many precedent investigations hate been made for the reliable assessment of the insulation state of large power apparatus for which partial discharge detection is one of tile plausible way. In this work, experimental investigations have been carried out to make the comparison on the PD(partial discharge) pattern analysis related to the five different types of artificial defects such as SFMP (Single Free Moving Particle), MFMP (Multi Free Moving Particle), Void, CFP (Conductor-Fixed Protrusion), EP (Enclosure Protrusion). For each PD pattern, PD detection has been done by tee different types of PD sensors such as HFCT(High Frequency Current Transformer), AE(Acoustic Emission) and UHF(Ultra High Frequency). And, in addition, frequency spectrum by the UHF sensor has been also made for each defect respectively. As a result, it is observed that the possibility of obtaining PD pattern based on PRPD(Phase Resolved Partial Discharge) in connection with the defects tinder investigation is dependant on the type of the sensor while the spectrum analysis is always successful to be achieved for every defect. Therefore, it could be suggested that the nature of PD source can be identified more distinctively when the conventional PRPDA is combined with spectrum analysis.

• 한국식물병리학회지
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• 제14권5호
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• pp.519-525
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• 1998

Intraspecific genetic diversity of Korean isolates of Phytophthora drechsleri was investigated based on PCR-RFLP of rDNA along with closely related species in the genus; P. cryptogea, P. melonis, P. erythroseptica, P. cinnamomi, P. cambivora and P. cactorum. Gene regions of nuclear small subunit and internal transcribed spacer (ITS) in rDNA were amplified with polymerase chain reaction and digested with 9 restriction enzymes. Phytophthora species was readily differentiated from each other based on the digestion patterns, however, P. cryptogea was not separable from some isolates of P. drechsleri. Twenty one isolates of P. drechsleri originated from 15 host plants were divided into three distinct groups designated as PdG1, PdG2 and PdG3, respectively. Four isolates in PdG1 were originated from green vegetables and tomato and nine isolates in PdG2 were mainly isolated from medicinal plants. The two groups showed 95.3% homology and four isolates of P. cyptogea came under the groups. However, Eight isolates in PdG3 collected from cucurbits were clearly differentiated from those of PdG1 and PdG2 by 66.5% homology, but completely matched with a Taiwan isolate of P. melonis. Results indicated that three distinct groups exist in Korean isolates of P. drechleri and each group has host preference. In addition, reclassification of the cucurbits isolates are reserved because of their distinct genetic characters from other intraspecific groups in P. drechsleri.

• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.488-493
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• 2022

Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.219-227
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• 2021

Hydrogen isotopes, which are used as raw materials in fusion reaction, participate in the reaction only in small amount, and most of them are released together with impurities. In order to recover and reuse only hydrogen isotopes from this exhaust gas, a recovery process is required, and most of the hydrogen isotopes can be recovered using a Pd Membrane. In this study, the recovery rate of hydrogen isotopes was measured through the first and second stage Pd membrane experiments. In the case of the experiment using a single stage Pd membrane, about 99.2%, and in the case of the first stage and second stage Pd membrane connection experiments, a recovery rate of 99.9% or more was obtained. Therefore, the recovery rate of Pd membrane process applied to hydrogen can be applied to hydrogen isotopes. In addition, the simulation model was established using aspen custom modeler, a commercial software, and the validity of the simulation was checked by applying the references and experimental data. The simulation results based on the experimental data showed a difference of 2% or less.

• 멤브레인
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• 제32권6호
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• pp.456-464
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• 2022

본 실험에서는 무전해 도금을 통하여 Pd 및 Pd-Cu 분리막을 제조하여 수소 투과 성능을 분석하였다. 분리막의 지지체는 α-Al₂O₃ 세라믹 중공사를 사용하였다. Pd-Cu 분리막은 무전해 도금을 실시하였고 Pd-Cu 합금을 만들기 위하여 수소 분위기에서 500°C, 18 h 동안의 열처리 과정을 거쳤다. 그 후, Pd-Cu 분리막은 EDS (Energy Dispersive X-ray Spectroscopy), XRD (X-ray Diffraction) 분석을 통해 합금이 형성된 것을 확인하였다. Pd 및 Pd-Cu 도금층의 두께는 SEM (Scanning Electron Microscope) 분석을 통해 각각 약 3.21, 3.72 µm으로 측정되었다. 수소 투과 성능은 수소 단일 가스, 혼합가스(H₂, N₂)에서 350~450°C, 1~4 bar의 범위에서 수소 투과 실험을 진행하였다. 수소 단일 가스에서 Pd 및 Pd-Cu 분리막은 450°C, 4 bar에서 최대 54.42, 67.17 ml/cm²⋅min의 flux를 가지며, 혼합가스에서는 450°C, 4 bar의 조건일 때, 각각 1308, 453의 separation factor가 나오는 것을 확인하였다.

• 대한치과기공학회지
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• 제20권1호
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• pp.37-49
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• 1998

실용치과재료로 사용되고 있는 Ag-Pd-Cu 3 원계 합금의 시효석출과정을 Pd 및 Cu의 용질 농도의 조성비가 약 1.7인 합금과 이 합금에서 2wt%Au의 첨가합금에 미치는 영향을 조사 분석하여 아래와 같은 결론을 얻었다. Ag-25Pd-15Cu 3원 합금은 ${\alpha}$의 단일상에서 ${\alpha}_1$ (Cu-rich), ${\alpha}_2$(Ag-rich) 및 PdCu 규칙상에 의해서 경화반응이 진행되며 연속승온시효에 의하면 $100{\sim}300^{\circ}C$의 저항증가와 $300{\sim}500^{\circ}C$의 저항감소라고 하는 2단계 변화에 의해서 경화곡선이 얻어졌다. 또한 본 합금의 시효과정은 ${\alpha}{\to}{\alpha}+{\alpha}_2+PdCu{\to}{\alpha}_1+{\alpha}_2+PdCu$이고 2상분리 반응에 경화되며 최고경화는 ${\alpha}_1,\;{\alpha}_2$ 및 PdCu 규칙상의 혼합영역에서 나타났다. 이들 석출반응은 입계반응이고 반응의 진행과 함께 경도값은 상승하고 경화촉진에 기여하였다. 또한 Nodule은 미세한 lamella조직을 나타내고 이들 ${\alpha}_2$와 PdCu상과의 미세한 혼합상의형성이 시효경화에 기여하는 주된 원인이 되었다. 과시효는 lamella의 조대화와 PdCu상의 ${\alpha}2$상으로의 용해에 따른 정량적 감소에 대응하였다. 석출상은 thin lamella구조의 잘 방위된 미세한 판상석출물로서 이들 미세 판상석출물은 AuCu($L1_0$)type의 face-centered tetragonal(fct)의 초격자구조였다. 규칙화된 미세한 판상석출물은 stair-step mode로서 twinning에 의해 형성되며 이것은 시효에 의해 $L1_0$ type의 PdCu 규칙상과 같은 초격자 형성시 정방비틀림 때문이라고 생각된다. 이들 twinning lamella는 귀금속원소에 의해 형성된 $L1_0$ type의 PdCu 규칙상과 같기 때문에 이들 합금의 부식저항에도 기여하였다. Ag-25Pd-15Cu합금은 전반적으로 양호한 내식성을 나타내며 Pd.Cu=1인 합금에서보다도 Pd함량이 높은 Pd/Cu=1.7에서 내식성이 보다 우수한 것은 Pd 함량이 내식성에 기여하였고 2%Au의 첨가에 의해서 부식성을 개선할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1205-1208
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• 2014

• 대한치과기공학회지
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• 제21권1호
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• pp.27-41
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• 1999

치과용 Ag기 합금에서 30wt%Pd 및 10wt%Cu의 용질농도의 구성비가 3이 되는 3원 합금과 여기에 2wt% Au의 첨가에 미치는 석출상의 영향을 조사 분석하여 아래와 같은 결론을 얻었다. Ag-Pd-Cu 3원 합금은 $\alpha$ 단일상에서 Ag-rich ${\alpha}_2 $ 및 PdCu 규칙상에 의해서 경화반응이 진행되며 연속승온시효곡선에 의하면 100-$300^{\circ}C$의 저항증가와 300-$500^{\circ}C$의 저항감소라고 하는 2단계 변화에 의해서 경화곡선이 얻어졌다. 또한 본 합금의 시효과정에서는 ${\alpha}{\to}{\alpha}_2+PdCu{\to}$의 2상 분리반응에 의하여 경화원인이 되었다. 석출과정은 ${\alpha}{\to}{\alpha}_1+PdCu{\to}{\alpha}_2+PdCu$ 이고 Cu-rich인 ${\alpha}_2$상은 거의 나타나지 않으며 최고 경도값은 ${\alpha}_2$ 및 PdCu의 2상공존 구역에서 나타났다. 미량의 Au첨가에 의해서 경화는 다소 증가하지만 경화성보다는 내식성에 보다 크게 기여하였고 Pd/Cu=3인 합금은 Pd/Cu=1 또는 1.7의 합금보다도 전반적으로 경도값은 가장 낮게 나타나며 이것은 치과용 Ag기 합금의 시효경화성에는 Cu농도가 크게 기여하였다. 불연속석출물인 nodule 생성물은 입계에 우선 형성되어 $\alpha$ matrix로 진행되어 nodule 석출물은 부드러운 경계면을 가지고 $\alpha$ matrix주위에 strain matrix를 나타내므로 nodule 형성이 본 합금의 시효경화를 야기하였다. 내식성은 Pd 함량이 가장 높은 본 합금에서 매우 양호하게 나타났으며 Pd 함량이 증가가 내식성의 향상에 크게 기여하여 미량의 Au 첨가에 의해서 보다 현저히 효과를 얻었다. 본 합금의 시효열처리 조건은 $450^{\circ}C$ 적절하며 1-120min 시효시간에 걸쳐서 소정의 경도 값을 얻을 수 있고 시효경화성 및 내식성의 결과로부터 Ag-30wt%Pd-10wt%Cu합금 및 미량 Au 합금은 치과용 금속재료로 적합하였다.