Conventional and inverse magnetocaloric effects, and critical behaviors in Ni₄₃Mn₄₆Sn₈In₃ alloy

Thanh, T.D.,Nan, W.Z.,Nam, G.,Van, H.T.,You, T.S.,Phan, T.L.,Yu, S.C. Elsevier 2015 CURRENT APPLIED PHYSICS Vol.15 No.10

A systematic study of the conventional and inverse magnetocaloric effects, and critical behaviors in an alloy ingot of Ni<SUB>43</SUB>Mn<SUB>46</SUB>Sn<SUB>8</SUB>In<SUB>3</SUB> has been performed. Our results reveal the sample exhibiting structural and magnetic phase transitions at temperatures T<SUB>C</SUB><SUP>M</SUP> = 166 K (T<SUB>C</SUB> of the martensitic phase), T<SUB>M-A</SUB> = 260 K (the martensitic-to-austenitic phase transformation) and T<SUB>C</SUB><SUP>A</SUP> = 296 K (T<SUB>C</SUB> of the austenitic phase). The large values of refrigerant capacity (RC) around T<SUB>M-A</SUB> and T<SUB>C</SUB><SUP>A</SUP> are found to be RC<SUB>M-A</SUB> = 172.6 and RC<SUB>A</SUB> = 155.9 J kg<SUP>-1</SUP>, respectively, under an applied field change of 30 kOe. Our critical analyses near the T<SUB>C</SUB><SUP>M</SUP> and T<SUB>C</SUB><SUP>A</SUP> reveal that a coexistence of the long- and short-range ferromagnetic order in the martensitic phase, while the long-range ferromagnetic order exists in the austenitic phase. Interestingly, at around T<SUB>C</SUB><SUP>A</SUP>, the maximum magnetic entropy change (|ΔS<SUB>max</SUB>|) versus magnetic field H obeys a power law, |ΔS<SUB>max</SUB>| = a.H<SUP>n</SUP>, where the exponent n is found to be about 0.66.

Levels of 4-1BB transcripts and soluble 4-1BB protein are elevated in the adipose tissue of human obese subjects and are associated with inflammatory and metabolic parameters

Tu, T H,Kim, C-S,Kang, J-H,Nam-Goong, I S,Nam, C W,Kim, E S,Kim, Y I,Choi, J I,Kawada, T,Goto, T,Park, T,Yoon Park, J H,Choi, M-S,Yu, R Macmillan Publishers Limited 2014 International journal of obesity Vol.38 No.8

Background:4-1BB, a member of the TNF receptor superfamily, has a role in various inflammatory pathologies through its interaction with 4-1BB ligand. We previously demonstrated that it participates in initiating and promoting obesity-induced adipose inflammation in a rodent model.Objective:In this study, we examined whether 4-1BB is related to obesity-induced adipose inflammation and metabolic parameters in humans.Methods:A total of 50 subjects, 25 obese (body mass index (BMI)⩾25 kg m<SUP>−2</SUP>) and 25 lean (BMI<23 kg m<SUP>−2</SUP>) participated in the study. The levels of 4-1BB transcripts and soluble 4-1BB protein (s4-1BB) in subcutaneous adipose tissue were measured by quantitative real-time PCR and enzyme-linked immunosorbent assay, respectively. Inflammatory and metabolic parameters were measured by enzymatic analysis and immunoassay.Results:Obese subjects had higher levels of both 4-1BB transcripts and s4-1BB protein in subcutaneous adipose tissue than lean controls, and the levels were correlated with BMI and the expression of inflammatory markers, as well as with serum metabolic parameters. Moreover, s4-1BB was released from human adipocytes, and elicited chemotactic responses from human monocytes/T cells as well as enhancing their inflammatory activity, indicating that it may promote human adipose inflammation.Discussion:Our data demonstrate that elevated levels of 4-1BB transcripts and s4-1BB in adipose tissue are closely associated with obesity-induced inflammation and metabolic dysregulation. They suggest that both 4-1BB transcripts and s4-1BB could serve as novel biomarkers and/or therapeutic targets for obesity-induced inflammation and metabolic syndrome in humans.

채종박 품질이 이유돈의 성장에 미치는 영향

강창원,남기택,임호중,공진훈,안상태 한국축산학회 1995 한국축산학회지 Vol.37 No.4

This study was made to evaluate the nutritional values and glucosinolate contents of three types of rapeseed oil meal(RSM), originated from Canada(canola), China(CRSM:Chinese Rapeseed Oil Meal) and India (IRSM:Indian Rapeseed Oil Meal), and their dietary effects on the performance of weanling pigs. Nutritional evaluation included the contents of moisture, crude protein(CP), ether extracts (EE), crude fiber(CF), Ash, Ca and P, KOH solubility, tannin, and glucosinolate contents of each RSM. Total of two hundred-forty weanling pigs weighing about 20㎏ initially were housed in 24 pens with 10 pigs per pen. The thirty animals were assigned to one of eight rations : T₁ (0% RSM + 2% molasses), T₂ (6% canola + 2% molasses), T₃ (6% CRSM + 2% Molasses), T₄(6% IRSM + 2% molasses), T_5 (0% RSM + 5% molasses), T_6 (6% Canola + 5% molasses). T_7 (6% CRSM + 5% molasses), T_8 (6% IRSM + 5% molasses). During the experimental period, body weight and feed intakes were measured weekly and feed conversion rates were calculated. The results obtained from this experiments are summarized as follows. 1. The KOH solubility of canola, CRSM and IRSM was found to be 54.6, 35.7 and 64.8%, respectively. The glucosinolate contents of canola, CRSM and IRSM were found to be 0.11, 0.22 and 0.79%, respectively. 2. There were no significant differences between the 2% molasses and the 5% molasses supplemented groups in feed intake and body weight gain. 3. The 6% CRSM(T₃, T_7) and IRSM(T₄, T_8) groups were significantly (P$lt;0.05) inferior to the control groups(T₁, T_5) and 6% canola groups(T₂, T_6) in feed intake and body weight gains. The control groups(T₂, T_6) were significantly (P$lt;0.05) superior to the 6% canola groups(T₂, T_6), 6% CRSM(T₃, T_7) and 6% IRSM groups(T₄, T_8) in feed conversion rate.

Electrical and Magnetotransport Properties of <inline-formula> <tex-math notation='TeX'> <tex> ${\rm La}_{{0.7}}{\rm Ca}_{{0.3}}{\rm Mn}_{{1-x}}{\rm Co}_{{x}}{\rm O}_{3}$ </tex> </tex-math></inline-formula>

Tran Dang Thanh,Phan, T. L.,Phung Quoc Thanh,Hoang Nam Nhat,Duong Anh Tuan,Yu, S. C. IEEE 2014 IEEE transactions on magnetics Vol.50 No.6

<P>This paper presents a detailed study on the Co-doping influence on the electrical and magnetotransport properties of La0.7Ca0.3Mn1-xCoxO3(x = 0.09-0.17) prepared by solid-state reaction. Magnetic measurements versus temperature revealed a gradual decrease of the magnetization (M) and Curie temperature (T-C) with increasing Co concentration (x). The T-C values vary from 194 to 159 K as changing x from 0.09 to 0.17, respectively. H/M versus M-2 performances around T-C prove the x = 0.09 sample undergoing a first-order magnetic phase transition (FOMT) while the samples with x >= 0.11 undergo a second-order magnetic phase transition (SOMT). The other with x = 0.10 is considered as a threshold concentration of the FOMT-SOMT transformation. Considering temperature dependences of resistivity, rho(T), in the presence and absence of the magnetic field, the samples (excepting for x = 0.17) exhibit a metal-insulator transition at T (P) = 60-160 K, which shifts toward lower temperatures with increasing x. In the metallic-ferromagnetic region, the rho(T) data are well fitted to a power function rho(T) = rho(0) + rho(2) T-2 + rho(4.5) T-4.5. This indicates electron-electron and electron-magnon scattering processes are dominant at temperatures T < T (P). In addition, the conduction data at temperatures T > theta(D)/2 (theta(D) is the Debye temperature) and T (P) < T < theta(D)/2 obey the small-polaron and variable-range hopping models, respectively. The values of activation energy E-p, and density of states at the Fermi level N(E-F) were accordingly determined. Here, N(E-F) increases while E-p decreases when an external magnetic field is applied. We also have found that N(E-F) increases when materials transfer from the FOMT to the SOMT, and N(E-F) value becomes smallest for the sample having the coexistence of the FOMT and SOMT (i.e., x = 0.10).</P>

Prediction of pathologic staging with magnetic resonance imaging after preoperative chemoradiotherapy in rectal cancer: Pooled analysis of KROG 10-01 and 11-02

Lee, J.H.,Jang, H.S.,Kim, J.G.,Lee, M.A.,Kim, D.Y.,Kim, T.H.,Oh, J.H.,Park, S.C.,Kim, S.Y.,Baek, J.Y.,Park, H.C.,Kim, H.C.,Nam, T.K.,Chie, E.K.,Jung, J.H.,Oh, S.T. Elsevier Science Publishers 2014 Radiotherapy and oncology Vol.113 No.1

Background and purpose: The reported overall accuracy of MRI in predicting the pathologic stage of nonirradiated rectal cancer is high. However, the role of MRI in restaging rectal tumors after neoadjuvant CRT is contentious. Thus, we evaluate the accuracy of restaging magnetic resonance imaging (MRI) for rectal cancer patients who receive preoperative chemoradiotherapy (CRT). Methods and materials: We analyzed 150 patients with locally advanced rectal cancer (T3-4N0-2) who had received preoperative CRT. Pre-CRT MRI was performed for local tumor and nodal staging. All patients underwent restaging MRI followed by total mesorectal excision after the end of radiotherapy. The primary endpoint of the present study was to estimate the accuracy of post-CRT MRI as compared with pathologic staging. Results: Pathologic T classification matched the post-CRT MRI findings in 97 (64.7%) of 150 patients. 36 (24.0%) of 150 patients were overstaged in T classification, and the concordance degree was moderate (k=0.33, p<0.01). Pathologic N classification matched the post-CRI MRI findings in 85 (56.6%) of 150 patients. 54 (36.0%) of 150 patients were overstaged in N classification. 26 patients achieved downstaging (ycT0-2N0) on restaging MRI after CRT. 23 (88.5%) of 26 patients who had been downstaged on MRI after CRT were confirmed on the pathological staging, and the concordance degree was good (k=0.72, p<0.01). Conclusions: Restaging MRI has low accuracy for the prediction of the pathologic T and N classifications in rectal cancer patients who received preoperative CRT. The diagnostic accuracy of restaging MRI is relatively high in rectal cancer patients who achieved clinical downstaging after CRT.

Large Magnetic Entropy Change in La_0.6Ce_0.4Fe_11.5Si_1.5 Alloy Exhibiting First- and Second-Order Phase Transitions

Tran Dang Thanh,Nan, W. Z.,Jeon, B. Y.,Yu, T. S.,Jong Suk Lee,Hoang Nam Nhat,Seong Cho Yu IEEE 2016 IEEE magnetics letters Vol.7 No.-

<P>A polycrystalline alloy ingot of La<SUB>0.6</SUB>Ce<SUB>0.4</SUB>Fe<SUB>11.5</SUB>Si<SUB>1.5</SUB> was prepared by an arc-melting method. Magnetic measurements of magnetization M as a function of field H and temperature T show a ferromagnetic-paramagnetic phase transition at a Curie temperature TC = 170 K. Interestingly, curves of H/M versus M<SUP>2</SUP> have a positive slope at low field (H ≤ 10 kOe), which corresponds to a second-order phase transition (SOPT), but a negative slope at high field (H > 10 kOe), which corresponds to a first-order phase transition (FOPT). The magnetic entropy change ΔS<SUB>m</SUB>(T) under different ranges of field change ΔH, calculated from M(H) isotherms, has a maximum IΔS<SUB>max</SUB>I around TC that increases in magnitude with increasing ΔH. Refrigerant capacity (RC), indicative of magnetic cooling efficiency, also increases with increasing ΔH. Curves of ΔS<SUB>m</SUB>(T)/ΔS<SUB>max</SUB> versus θ = (T - TC)/(Tr - TC), where Tr is the reference temperature, collapse into a universal curve when ΔH ≤ 10 kOe. In contrast, curves of ΔS<SUB>m</SUB>(T)/ΔS<SUB>max</SUB> versus θ do not reduce to a universal curve when ΔH > 10 kOe. These suggest a coexistence of FOPT and SOPT properties in the alloy.</P>

Conserved sequences of thrombospondin‐related adhesive protein gene of <i>Plasmodium vivax</i> in clinical isolates from Korea

Nam, Myung H.,Jang, Jin W.,Kim, Hanna,Han, Eun T.,Lee, Won J.,An, Seong S. A.,Park, Ae S. D.,Lim, Chae S. Blackwell Publishing Ltd 2011 Tropical medicine & international health Vol.16 No.8

<P><B>Summary</B></P><P>Thrombospondin‐related adhesive protein (TRAP) from <I>Plasmodium vivax</I> (<I>P.?vivax</I>) became one of the important vaccine candidates for malaria, because <I>P.?vivax</I> TRAP (PvTRAP) is responsible for the sporozoite–host interactions. PvTRAP polymorphisms in the isolates from Republic of Korea (ROK) were analysed, setting the valuable baseline data for the future vaccine developments and clinical trials with PvTRAP, as a strong vaccine candidate. A total of 54 isolates were collected in 2010. PvTRAP genes from above isolates were amplified and sequenced, and the results were analysed and compared against Sal‐1 strain. Sequencing analysis of 1424‐bp‐size PvTRAP PCR products revealed one major allelic type with six non‐synonymous substitutions, where S81T, E95D, I121V and T127R substitutions were found in region II, and K371N and A425E substitutions from region IV. The ROK isolates revealed the limited sequence polymorphisms in PvTRAP in comparison with the reported isolates from other nations.</P>

Biomarkers indicate mixture toxicities of fluorene and phenanthrene with endosulfan toward earthworm (Eisenia fetida)

Nam, T. H.,Kim, L.,Jeon, H. J.,Kim, K.,Ok, Y. S.,Choi, S. D.,Lee, S. E. Springer Science + Business Media 2017 Environmental geochemistry and health Vol.39 No.2

<P>alpha-Endosulfan and some polycyclic aromatic compounds (PAHs) are persistent in the environment and can reach crop products via contaminated agricultural soils. They may even be present as mixtures in the soil and induce mixture toxicity in soil organisms such as earthworms. In this study, the combined toxicities of PAHs with alpha-endosulfan were determined in Eisenia fetida adults using an artificial soil system. alpha-Endosulfan and five PAHs were tested for their acute toxicity toward E. fetida in artificial soils. Only alpha-endosulfan, fluorene, and phenanthrene showed acute toxicities, with LC50 values of 9.7, 133.2, and 86.2 mg kg(-1), respectively. A mixture toxicity assay was conducted using alpha-endosulfan at LC10 and fluorene or phenanthrene at LC50 in the artificial soils. Upon exposure to the mixture of fluorene and alpha-endosulfan, earthworms were killed in increasing numbers owing to their synergistic effects, while no other mixture showed any additional toxicity toward the earthworms. Along with the acute toxicity results, the biochemical and molecular changes in the fluorene- and phenanthrene-treated earthworms with or without alpha-endosulfan treatment demonstrated that enhancement of glutathione S-transferase activity was dependent on the addition of PAH chemicals, and the HSP70 gene expression increased with the addition of alpha-endosulfan. Taken together, these findings contribute toward understanding the adverse effects of pollutants when present separately or in combination with other types of chemicals.</P>

인버터 고전압 전원공급장치를 이용한 펄스전원공급장치 연구

박성수(S.S. Park),김상희(S.H. Kim),황정연(J.Y. Hwang),남상훈(S.H. Nam),이경태(K.T. Lee),김흥근(H.G. Kim) 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-

The klystron-modulator(K&M) system of the Pohang Light Source(PLS) had been supplying high power microwaves for the acceleration of 2.5 GeV electron beams since October 2002. There are 12 sets of K&M systems to accelerate electron beams to 2.5GeV nominal beam energy. One module of the K&M system consists of an 80 MW S-band (2856 MHZ) klystron tube and the matching 200 MW modulator. In order to obtain electron beam of the consequently stability for linac, the pulse-to-pulse beam voltage regulation is less than +/- 0.5 %. To get the reliable stability of the modulator which is less than +/- 0.5 %, a charging section is improved in a modulator which has been operated with inverter power supply.

부분가열 T-형 열간단조공정의 마모현상의 유한요소해석

김민철(M. C. Kim),남찬희(C. H. Nam),남태현(T. H. Nam),강석순(S. S. Kang),전만수(M. S. Joun) 한국소성가공학회 2014 한국소성가공학회 학술대회 논문집 Vol.2014 No.5

In this paper, finite element analysis of die wear phenomenon in hot forging of a partially heated material for T-shape product is conducted using a rigid-thermoviscoplastic finite element method with an Archard wear model. The entire process including partial heating process and two hot forging stages is dealt with. The predictions are compared with experiments in terms of die wear in a qualitative manner. The comparison shows a good agreement between the predictions and experiments.