Paleovegetation and paleoclimate changes based on terrestrial n-alkanes and their carbon isotopes in sediment from the Jeongok-ri Paleolithic Site, Korea

Hyun, S.,Suh, Y.J.,Shin, K.H.,Nam, S.I.,Chang, S.W.,Bae, K. Pergamon Press 2015 QUATERNARY INTERNATIONAL Vol.384 No.-

Carbon isotope of total organic carbon (δ<SUP>13</SUP>C<SUB>org</SUB>) and long-chain n-alkanes, which are terrestrial plant biomarkers, and their compound-specific carbon isotope ratios (δ<SUP>13</SUP>C<SUB>ALK</SUB>) were investigated in the sediment of the Jeongok-ri Paleolithic Site in central Korea to interpret changes in paleovegetation and paleoclimate. The δ<SUP>13</SUP>C<SUB>org</SUB> ranged between approximately -24%% and -27%%, suggesting different organic matter sources. Relatively lighter δ<SUP>13</SUP>C<SUB>org</SUB> occurred in lower part and the occurrence of heavier δ<SUP>13</SUP>C<SUB>org</SUB> in upper part may indicate terrestrial C<SUB>3</SUB> plant dominance and/or a mixture of C<SUB>3</SUB> and C<SUB>4</SUB> plants, respectively. The patterns of n-alkane distribution were characterized by a continuous predominance of odd-numbered n-alkanes, particularly nC<SUB>29</SUB> and nC<SUB>31</SUB>, and by variation in the distribution of even-numbered n-alkanes. Total concentration of n-alkanes and distributions of each number of n-alkanes are quite different over time, suggesting paleovegetation changes. The average chain length (ACL) and carbon preferences index (CPI) showed gradual variations with distinctive switching points at about 160 ka. This variation reflecting changes in paleovegetation type, is coincident with those of the δ<SUP>13</SUP>C<SUB>org</SUB>. Individual n-alkane isotopes, δ<SUP>13</SUP>C<SUB>ALK</SUB>, ranged between -18.64%% and -38.09%%, suggesting different sources of n-alkanes. Although some petrogenic sources of n-alkanes were possible, the distribution of n-alkanes and their δ<SUP>13</SUP>C<SUB>ALK</SUB> support paleovegetation and paleoclimatic variations in Jeongok-ri Paleolithic site, Korea for the last 300 ka.

High-Pressure Synthesis of $SmFeAsO_{1-x}F_x$(x=0.2) Single Crystals

이현숙,박재현,이재엽,김주영,조병기,정창욱,이후종,Lee, Hyun-Sook,Park, Jae-Hyun,Lee, Jae-Yeap,Kim, Ju-Young,Cho, B.K.,Jung, Chang-Uk,Lee, Hu-Jong The Korean Superconductivity Society 2009 Progress in superconductivity Vol.10 No.2

Fluorine-doped $SmFeAsO_{1-x}F_x$ single crystals with the nominal value of x=0.2 were grown at $1350-1450^{\circ}C$ under the pressure of 3.3 GPa by using the self-flux method. Plate-shaped single crystals in the range of a few-150 ${\mu}m$ in their lateral size were obtained. The detailed crystal structure was analyzed by using the x-ray diffractometry. Superconducting transition temperature, determined by the resistive transition, of a single crystal was about 49 K with a narrow resistive transition width of ${\sim}1$ K. A relatively sharp transition, a low residual resistivity, and a large residual resistivity ratio compared with those reported for $REFeAsO_{1-x}F_x$(RE=Sm, Nd) single crystals indicate the high quality of our single crystals.

소결 알루미늄 고체축전기의 제조조건과 전기적특성

장현구,윤용구 대한금속재료학회(대한금속학회) 1971 대한금속·재료학회지 Vol.9 No.3

燒結 알루미늄 固體蓄電器의 製造 條件과 電氣的 特性에 對하여 硏究하였다. 燒結陽極素子의 有孔度는 粘結劑의 含量과 成型壓力을 變化시켜 주므로 調節하였다. 3% 붕산암모늄 수용액 중에서 陽極酸化시켜 多孔質素子의 表面上에 誘電皮膜을 입혀 주었다. 질산망간의 熱分解에 의하여 誘電酸化皮膜上에 固體電解質을 被覆 하였으며 熱分解와 再化成을 數回 반복하였다. 이와같이 製造된 燒結 알루미늄 固體蓄電器의 電氣的 特性은 알루미늄 電解蓄電器 보다는 優秀 하였지만 탄탈 固體蓄電器 보다는 劣等 하였다. g당 容量 2,450 μF·V를 얻었지만 漏洩電流는 아직도 充分히 낮추지 못하였다. 이 事實은 알루미늄의 燒結溫度가 낮기 때문에 陽極素子內에 不純物이 철저히 除去되지 못함에 기인한다고 생각된다. Fabrication variables of sintered aluminum solid capacitors were studied in relation to their electrical properties. The porosity of anode pellets was controlled by varying the content of binder and compacting pressure. The dielectric oxide layer on the porous surface of sintered anode pellets was formed by anodizing in 3% ammonium borate aqueous solution. The solid electrolyte on the dielectric oxide layer was applied by pyrolysis of manganese nitrate. Pyrolysis and reformation at a reduced voltage were repeated a few times. Electrical properties of sintered aluminum solid capacitors so fabricated were superior to those of aluminum electrolytic capacitors whereas they were inferior to those of sintered tantalum solid capacitors. A capacitance-voltage product of 2.450 μF·V/gram was achieved but a sufficiently low leakage current was not achieved as yet. This fact may be attributable to low sintering temperature and consequently, relatively high contents of impurity remaining in sintered anode pellets.

작용기를 포함하는 새로운 거대고리 폴리에테르의 합성

장승현,김동준,이갑득 대구대학교 부설 과학교육연구소 1993 과학교육 Vol.6 No.-

동전위 양극분극법에 의한 스텐레스강의 공식에 관한 연구

장현구 한국부식학회 1981 Corrosion Science and Technology Vol.10 No.1

The potentiokinetic anodic polarization method was applied to study the effects of some factors on pitting potential of stainless steel in 0.1N sulfuric acid solution containing chloride ion. Pitting potentials were varied with the potential scan rate and the surface roughness of specimen. The slow scan rate and the rough surface shifted the pitting potential to active direction. Increase in chloride ion concentration in 0.1N sulfuric acid solution reduced the pitting potential. Sensitizing treatment at 650℃ lowered pitting potential and made pitting initiation easy.

염화물 액상중에서의 강의 공식에 대한 소고

장현구 한국부식학회 1973 Corrosion Science and Technology Vol.2 No.1

Aerosol delivery of urocanic acid-modified chitosan/programmed cell death 4 complex regulated apoptosis, cell cycle, and angiogenesis in lungs of K-ras null mice.

Jin, Hua,Kim, Tae Hee,Hwang, Soon-Kyung,Chang, Seung-Hee,Kim, Hyun Woo,Anderson, Hanjo K,Lee, Han-Woong,Lee, Kee-Ho,Colburn, Nancy H,Yang, Hsin-Sheng,Cho, Myung-Haing,Cho, Chong Su American Association for Cancer Research, Inc 2006 Molecular cancer therapeutics Vol.5 No.4

<P>The low efficiency of conventional therapies in achieving long-term survival of patients with lung cancer calls for development of novel treatment options. Although several genes have been investigated for their antitumor activities through gene delivery, problems surrounding the methods used, such as efficiency, specificity, and toxicity, hinder application of such therapies in clinical settings. Aerosol gene delivery as nonviral and noninvasive method for gene therapy may provide an alternative for a safer and more effective treatment for lung cancer. In this study, imidazole ring-containing urocanic acid-modified chitosan (UAC) designed in previous study was used as a gene carrier. The efficiency of UAC carrier in lungs was confirmed, and the potential effects of the programmed cell death protein 4 (PDCD4) tumor suppressor gene on three major pathways (apoptosis, cell cycle, and angiogenesis) were evaluated. Aerosol containing UAC/PDCD4 complexes was delivered into K-ras null lung cancer model mice through the nose-only inhalation system developed by our group. Delivered UAC/PDCD4 complex facilitated apoptosis, inhibited pathways important for cell proliferation, and efficiently suppressed pathways important for tumor angiogenesis. In summary, results obtained by Western blot analysis, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated nick end labeling assay suggest that our aerosol gene delivery technique is compatible with in vivo gene delivery and can be applied as a noninvasive gene therapy.</P>

Large infantile hemangioma with subfascial location: a case with difficulty of clinical diagnosis

( Dae-lyong Ha ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Tae-wook Kim ),( Sung-min Park ),( Hyun-joo Lee ),( Gun-wook Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum Kim ),( Hoon-soo K 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.1

The unexpected finding of newly growing lump in an infant induces anxiety to parents and results in an urgent visit to hospital. Before performing invasive interventions for this infant patient, benign conditions like infantile hemangioma (IH) should be excluded as it could show variable clinical characteristics. A 6-month-old girl was presented with protruding skin-colored tumor on right upper back, with approximately 10cm in diameter and without surface change. The tumor abruptly enlarged over the period of 2 weeks without any previous episode. MRI showed a lobulated hypervascular mass in the subfascial layer with neovascularization inside. Through this findings, thought by radiologist and orthopedic surgeon to be malignant tumor, exploratory surgery was planned. Before surgical excision, this patient was consulted to our department. As the lesion was softly palpable and movable, incisional biopsy was performed to rule out the benign tumor like deep type IH. Histopathologic examination showed numerous vessels lined by plump endothelial cells. Immunohistochemical staining revealed the positivity of endothelial cells for CD-31, GLUT-1. Under the diagnosis of IH, the patient received oral propranolol medication for 1 year. Following the patient, we found the tumor diminished dramatically in volume. Although IHs are common benign tumor in infancy, Subfascial location is unfamiliar and rare. So, we herein report a case of subfascial lH.

Effect of Radiofrequency Induced Local Hyperthermia on Normal Canine Liver

Chang Ok Suh(서창옥) , John J.K.Loh(노준규) , Jin Sil Seong(성진실) , Sun Rock Moon(문성록) Hyung Sik Lee(이형식) , Hyun Soo Shin(신현수) , Sung Sil Chu(추성실) , Gwi Eon Kim(김귀언) , Chan Il Park(박찬일) ,Eun Kyung Han(한은경) 대한방사선종양학회 1991 Radiation Oncology Journal Vol.9 No.1

간조직에 온열치효를 시행시 출현하는 조직병리학적 소견 및 혈액의 생화학적 소견을 관찰하고자 13마리의 정상 간에 8MHz 라디오파를 이용한 온열치료를 시행하였다. 42.5±0.5°C로 30분간 온열치료를 받은 군 (제1군, n=5), 45±0.5°C로 30분간 온열치료를 받은 군 (제2군, n=5) 및 온열치료를 받지않은 대조군(n=3)으로 나누어 분석하였을때, 혈액의 SGOT의 SGPT는 온열치료를 시행한 두군 공히 증가된 소견을 보였고 제 1군에서는 간세포의 부종소견의 특이한 조직병리학적소견이 관찰되지않아 가역성 변화로 생각되었지만 제2군에서는 간 세포의 심한 괴사소견이 관찰되어 있는 불가역성의 가조직 손상으로 생각되었다. 이상의 결론으로 유추할 때 임상에서 행하여지는 간암의 온열치료시에 정상 가조직의 손상을 가능한 방지하기위하여는 정확한 종괴의 구역에 치료온도의 주의깊은 관찰이 요구된다. In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthermia in canine liver were studied. Hyperthemia was externally adminsitered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. Group I (N=5) was heated with 42.5±0.5°C for 30 minutes, and Group Ⅱ (N=5) was heated with 45±0.5°C for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately after hyperthermia and 7, 14, and 28 days after treatment. Blood samples were obtained before treatment and 1, 3, 5, 7, 14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in Group Ⅰ. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with 45°C for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liver damage dy heat of 42.5±0.5°C for 30 minutes is reversible, and liver damage by heat of 45±0.5°C for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in order to apply hyperthermic treatment on human liver tumor safely, close observation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible.

Terrestrial n-alkanes and their carbon isotope records from the Hanon paleo-maar sediment, Jeju Island, Korea: Implications for paleoclimate and paleovegetation over the last 35 kyrs

Hyun, S.,Shin, K.H.,Lee, S.C.,Chang, S.W.,Nam, S.I. Pergamon Press 2017 QUATERNARY INTERNATIONAL Vol.441 No.1

<P>The carbon isotope of total carbon (delta C-13(org)), long-chain n-alkanes, and their compound-specific carbon isotope ratios (delta C-13(ALK)) were investigated in the Hanon paleo-maar sediment, Jeju Island of Korea to understand paleoclimate variabilities and their paleovegetation linkages. Based on the organic geochemical data (TOC (%), TN (%), and their delta C-13(org) and delta N-15), the core column stratigraphy was divided into three units, namely from the bottom to 14.5 ka (Unit I), from 14.5 ka to 3.01<a (Unit II), and from 3.0 ka to the core top (Unit III), respectively. In particular, delta C-13(org) showed marked fluctuation from -17.31%o to -28.68%o, suggesting different organic carbon sources. A relatively narrow range of variation in delta C-13(org) was observed in Unit III, and drastic changes in delta C-13(org) were observed from Unit I to Unit II. This may indicate a predominance of C-4 plants in Unit I, and drastic changes from terrestrial C-4 to C-3 in Unit II and predominance of C-3 plants in Unit III. The distributions of n-alkane were characterized by a continuous predominance of odd-numbered n-alkanes, particularly nC(29) and nC(31), and by high fluctuation of the total n-alkanes concentration. The average chain length (ACL), carbon preferences index (CPI), and paleoplant proxy (Paq) showed high fluctuation and glacial-interglacial variations with distinctive a high and low ratio at about 9.2 ka, corresponding to the switching points of delta C-13(org) and a high concentration of nalkane distribution. Individual n-alkane odd-numbered isotopes of delta C-13(Auc) ranged between -11.80%o in delta C-13n(21) and -34.93%o in delta C-13n(31), suggesting different sources of n-alkanes. The distribution of n-alkanes and their individual delta C-13(Auc), in particular delta C-13n(21), support paleovegetation changes, and their time dependent variations matched well with glacial-interglacial paleoclimate variations. Therefore, organic geochemical proxies recorded in Hanon paleo-maar sediment reflects paleoclimate variabilities as well as paleovegetation changes for the last 35 kyr in Jeju Island, Korea. (C) 2016 Elsevier Ltd and INQUA. All rights reserved.</P>