• Title/Summary/Keyword: $Mg_{2}Si$

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ORIGIN AND STATUS OF LOW-MASS CANDIDATE HYPERVELOCITY STARS

  • Yeom, Bum-Suk;Lee, Young Sun;Koo, Jae-Rim;Beers, Timothy C.;Kim, Young Kwang
    • Journal of The Korean Astronomical Society
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    • v.52 no.3
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    • pp.57-69
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    • 2019
  • We present an analysis of the chemical abundances and kinematics of six low-mass dwarf stars, previously claimed to be candidate hypervelocity stars (HVSs). We obtained moderate-resolution (R ~ 6000) spectra of these stars to estimate the abundances of several chemical elements (Mg, Si, Ca, Ti, Cr, Fe, and Ni), and derived their space velocities and orbital parameters using proper motions from the Gaia Data Release 2. All six stars are shown to be bound to the Milky Way, and in fact are not even considered high-velocity stars with respect to the Galactic rest frame. Nevertheless, we attempt to characterize their parent Galactic stellar components by simultaneously comparing their element abundance patterns and orbital parameters with those expected from various Galactic stellar components. We find that two of our program stars are typical disk stars. For four stars, even though their kinematic probabilistic membership assignment suggests membership in the Galactic disk, based on their distinct orbital properties and chemical characteristics, we cannot rule out exotic origins as follows. Two stars may be runaway stars from the Galactic disk. One star has possibly been accreted from a disrupted dwarf galaxy or dynamically heated from a birthplace in the Galactic bulge. The last object may be either a runaway disk star or has been dynamically heated. Spectroscopic follow-up observations with higher resolution for these curious objects will provide a better understanding of their origin.

Effects of Black rice (Oryza sativa L.) Aleurone layer on Cyclophosphamide-induced Immunosuppression in Mice (Cyclophosphamide에 의해 유도된 면역 저하 마우스에서 흑미 (Oryza sativa L.) 호분층의 면역 활성 효과)

  • Lee, Eun Byeol;Choi, Ji-Hye;Kim, Si Hyun;Jang, Hwan Hee;Lee, Sung Hyen
    • Korean Journal of Pharmacognosy
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    • v.52 no.3
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    • pp.170-176
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    • 2021
  • Anthocyanins are considered as one of the major functional components including cyanidin-3-glucoside and peonidin-3-glucoside anthocyanins of black rice (Oryza sativa L., BR) aleurone layer (OAL) extract. The immunomodulatory biological effects of OAL has rarely been evaluated. This study has extensively studied the immunomodulatory effects of BR in immunosuppressed mice by CPA. The immunostimulatory effects of BR extract in in vivo at 150 (OAL-1) and 300 mg/kg body weight (OAL-2) for OAL groups were measured and compared to the normal group (CON) ingested with distilled water only or other groups. After the 14 days of oral administration, immune related organ weights, serum immunoglobulin (Ig) A and IgG, and cytokines (IL-12, TNF-α) levels, splenocytes proliferation rate, and NK cell activity were evaluated as immune related biomarkers. The serum IgA and IgG values in the OAL-treated groups increased to the level of the CON. OAL significantly and effectively controlled the IL-12 and TNF-α levels and NK activity compared to the negative control (NC) group. The results suggest that BR aleurone layer with immunomodulatory activities has a great potential as a functional food by itself or as a supplement.

Renal Impairment Associated with Weekly Cisplatin and Gemcitabine Combination Therapy for Treatment of Biliary Tract Cancer

  • Galam Leem;Hee Seung Lee;Moon Jae Chung;Jeong Youp Park;Si Young Song;Seungmin Bang
    • Journal of Digestive Cancer Research
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    • v.4 no.1
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    • pp.36-38
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    • 2016
  • Biliary tract cancer, a relatively rare disease, is usually found in an unresectable stage. Weekly cisplatin plus gemcitabine has been applied as a standard first-line therapy for advanced biliary tract cancer, but almost up to 3-5% patients experience drug induced renal impairment. Many anticancer medication guidelines recommend drug adjustment when kidneys are damaged, but weekly cisplatin is somewhat low dose so that there is a controversy on reducing the dose. And it is known that the cumulative dose of cisplatin is the most important factor contributing to renal impairment. Therefore, clinicians face troubles whether or not to maintain the chemotherapy. Here, we reported a patient whose renal function (eGFR) had been decreased as the number of chemotherapy increased, so her chemotherapy should be stopped. Since we held the chemotherapy on her, the disease progressed aggressively. Weekly cisplatin regimen is just 25 mg/m2, so it may be meaningless to reduce this dose, and it is well known that cumulative dose of cisplatin is the most important factor contributing to renal impairment, it is better not to use cisplatin anymore. Therefore, we recommend that if the patient responds well to weekly cisplatin plus gemcitabine regimen, it would be beneficial to use gemcitabine alone.

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Method for the Assembly of a High-density Multi-channel Deformable Mirror for High Energy Lasers (고에너지 레이저용 고밀집 다채널 실리콘-카바이드 변형거울의 정밀 조립 방법)

  • Hyug-Gyo Rhee;Sunho Cho;Sihyun Kim;Jaehyun Lee;Pilseong Kang
    • Korean Journal of Optics and Photonics
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    • v.35 no.4
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    • pp.170-174
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    • 2024
  • A laser beam propagating in free space can be negatively affected by atmospheric turbulence. To overcome this and correct the wavefront error of the laser beam itself, a deformable mirror (DM), which is a key component of adaptive optics, is widely used. In this paper, a novel precision assembling method is suggested for a multi-channel high-density DM. The material of the mirror sheet of the DM is silicon carbide (SiC), and the actuator is a stacked-type lead-magnesium-niobate (Pb(Mg1/3Nb2/3)O3; PMN). To connect the mirror sheet and each actuator, a flexure is inserted. The flexure can make the DM operate with full strokes without the failure of adhesive. A series of jigs were designed and applied in order to assemble these three parts (the mirror sheet, actuators, and flexures) precisely. After assembly, the performance of the DM was also checked.

Geochemical Characteristics of Soils and Sediments at the Narim Mine Drainage, Korea: Dispersion, Enrichment and Origin of Heavy Metals (나림광산 수계의 토양과 퇴적물에 관한 지구화학적 특성: 중금속 원소의 분산, 부화 및 기원)

  • Lee, Chan Hee;Lee, Hyun Koo;Lee, Jong Chang
    • Economic and Environmental Geology
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    • v.31 no.4
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    • pp.297-310
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    • 1998
  • Geochemical characteristics of environmental toxic elements at the Narim mine area were investigated on the basis of major, minor, rare earth element geochemistry and mineralogy. Ratios of $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ in soils and sediments range from 11.57 to 22.21 and from 1.86 to 3.93, and are partly negative and positive correlation against $SiO_2/Al_2O_3$ (3.41 to 4.78), respectively. These suggested that sediment source of host granitic gneiss could be due to rocks of high grade metamorphism originated by sedimentary rocks. Characteristics of some trace and rare earth elements of V/Ni (0.33 to 1.95), Ni/Co (2.00 to 6.50), Zr/Hf (11.27 to 53.10), La/Ce (0.44 to 0.55), Th/Yb (4.07 to 7.14), La/Th (2.35 to 3.93), $La_N/Yb_N$ (6.58 to 13.67), Co/Th (0.63 to 2.68), La/Sc (3.29 to 5.94) and Sc/Th (0.49 to 1.00) are revealed a narrow range and homogeneous compositions may be explained by simple source lithology. Major elements in all samples are enriched $Al_2O_3$, MgO, $TiO_2$ and LOI, especially $Fe_2O_3$ (mean=7.36 wt.%) in sediments than the composition of host granitic gneiss. The average enrichment indices of major and rare earth elements from the mining drainage are 2.05 and 2.91 of the sediments and are 2.02 and 2.60 of the soils, normalizing by composition of host granitic gneiss, respectively. Average composition (ppm) of minor and/or environmental toxic elements in sediments and soils are Ag=14 and 1, As=199 and 14, Cd=22 and 1, Cu=215 and 42, Pb=1770 and 65, Sb=18 and 3, Zn=3333 and 170, respectively, and extremely high concentrations are found in the subsurface sediments near the ore dump. Environmental toxic elements were strongly enriched in all samples, especially As, Cd, Cu, Pb, Sb and Zn. The level of enrichment was very severe in mining drainage sediments, while it was not so great in the soils. Based on the EPA value, enrichment index of toxic elements is 8.63 of mining drainage sediments and 0.54 of soils on the mining drainage. Mineral composition of soils and sediments near the mining area were partly variable being composed of quartz, mica, feldspar, amphibole, chlorite and clay minerals. From the gravity separated mineralogy, soils and sediments are composed of some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, goethite and various hydroxide minerals.

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Surface Morphology of PEO-treated Ti-6Al-4V Alloy after Anodic Titanium Oxide Treatment (ATO 처리후, 플라즈마 전해 산화 처리된 Ti-6Al-4V 합금의 표면 형태)

  • Kim, Seung-Pyo;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2018.06a
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    • pp.75-75
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    • 2018
  • Commercially pure titanium (CP-Ti) and Ti-6Al-4V alloys have been widely used in implant materials such as dental and orthopedic implants due to their corrosion resistance, biocompatibility, and good mechanical properties. However, surface modification of titanium and titanium alloys is necessary to improve osseointegration between implant surface and bone. Especially, when titanium oxide nanotubes are formed on the surface of titanium alloy, cell adhesion is greatly improved. In addition, plasma electrolytic oxide (PEO) coatings have a good safety for osseointegration and can easily and quickly form coatings of uniform thickness with various pore sizes. Recently, the effects of bone element such as magnesium, zinc, strontium, silicon, and manganese for bone regeneration are researching in dental implant field. The purpose of this study was researched on the surface morphology of PEO-treated Ti-6Al-4V alloy after anodic titanium oxide treatmentusing various instruments. Ti-6Al-4V ELI disks were used as specimens for nanotube formation and PEO-treatment. The solution for the nanotube formation experiment was 1 M $H_3PO_4$ + 0.8 wt. % NaF electrolyte was used. The applied potential was 30V for 1 hours. The PEO treatment was performed after removing the nanotubes by ultrasonics for 10 minutes. The PEO treatment after removal of the nanotubes was carried out in the $Ca(CH_3)_2{\cdot}H_2O+(CH_3COO)_2Mg{\cdot}4H_2O+Mn(CH_3COO)_2{\cdot}4H_2O+Zn(CH_3CO_2)_2Zn{\cdot}2H_2O+Sr(CH_2COO)_2{\cdot}0.5H_2O+C_3H_7CaO_6P$ and $Na_2SiO_3{\cdot}9H_2O$ electrolytes. And the PEO-treatment time and potential were 3 minutes at 280V. The morphology changes of the coatings on Ti-6Al-4V alloy surface were observed using FE-SEM, EDS, XRD, AFM, and scratch tester. The morphology of PEO-treated surface in 5 ion coating solution after nanotube removal showed formation or nano-sized mesh and micro-sized pores.

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Inhibitory Effect of Garlic Extract on Histamine Accumulation in Mackerel Meat (마늘 추출물의 고등어육에서의 히스타민 생성 억제)

  • Shim, Jae-Hun;Paik, Hyun-Dong;Lee, Si-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.8
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    • pp.957-964
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    • 2017
  • This study was carried out to investigate the effects of garlic extract on histamine reduction in mackerel meat stored at $4^{\circ}C$ and $15^{\circ}C$, respectively. The number of total bacteria in mackerel meat treated with 7.5% garlic extract was ten times lower than that of the control stored for 6 days of $4^{\circ}C$. However, there was no difference among the samples after 9 days of storage. Reduction of eicosapentaenoic acid (C20:5) and docosahexaenoic acid (C22:6) contents was observed in the normal control group at both temperatures. However, contents of these two polyunsaturated fatty acids slightly increased in garlic extract-treated fish. Amounts of volatile basic nitrogen increased over time in the control group, but decreased in the garlic extract-treated meat, indicating that garlic extract might suppress decomposition. No histamine was detected initially in all samples. However, a small amount of histamine (42.87 mg/kg) was detected in the control at 3 days after storage at $4^{\circ}C$. Histamine content increased continuously with storage period but was lower in mackerel meat containing garlic extract, in which histamine suppression was proportional to the concentration of garlic extract. It can be concluded that garlic extract could be utilized to extend the storage period of mackerel.

A Case of Patient with Non-Small Cell Lung Carcinoma Treated with Samchilchoongcho-Jung in Conjunction with Crizotinib (비소세포성 폐암환자의 Crizotinib과 삼칠충초정 병용투여 경과관찰 1례)

  • Ha, Su jeong;Song, Si yeon;Park, So-jung;Jeon, Hyung-joon;Lee, Yeon-weol;Cho, Chong-kwan;Yoo, Hwa-seung
    • Journal of Korean Traditional Oncology
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    • v.23 no.1
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    • pp.23-32
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    • 2018
  • Objective: The purpose of this study is to report the case of a patient with non-small cell lung adenocarcinoma (NSCLC) with anaplastic lymphoma kinase (ALK) mutation treated by Samchilchoongcho-Jung in conjunction with Crizotinib. Methods: An NSCLC patient diagnosed with multiple pleural and lymph nodes metastasis has been taking Crizotinib (500 mg/day) since January 2014. The patient has been treated with Samchilchoongcho-Jung (1,500 mg/day) since June 2014. The tumor size was measured by computed tomography (CT) and laboratory analysis was conducted. Adverse events were evaluated by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), version 5.0. Results: After combining treatment, stable disease was shown on CT. The tumor marker (CEA, Cyfra 21-1) levels were maintained. NCI-CTCAE 5.0 showed no adverse events. Conclusion: This case study suggests that Samchilchoongcho-Jung may contribute to tumor response, in conjunction with Crizotinib on the treatment of patients with NSCLC.

Rheological Properties of Dough and Quality Characteristics of Bread Containing Whey Ferment Cultured by L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227 (L. acidophilus KCCM 32820과 P. freudenreichii KCCM 31227로 배양한 유청발효물을 첨가한 반죽 레올로지 및 식빵의 품질특성)

  • Lee, Jeong-Hoon;Choi, Mi-Jung;Chung, Koo-Chun;Lee, Si-Kyung
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.803-809
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    • 2012
  • This study was carried out to evaluate the effects of whey ferment containing L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227 on the quality characteristics of white pan bread. Instrumental analysis such as alveograph, gelatinization temperature, texture analysis, retrogradation rate was determined. In an alveograph test, $P_{max}$ value in the treatment was higher than that in the control, but extensibility of dough in the control showed to be higher than in the treatment, so test dough showed more strength than the control. In terms of DSC analysis for gelatinization, temperature there were no significant differences of $T_p$ and ${\Delta}H$ between the control and the treatment. In hardness analysis by rheometer, dough containing whey ferment revealed lower values than the control. From the analysis of the organic acid contents, propionic acid was not detected in the control, however 1.13 mg/g of propionic acid was detected in the treatment. In the retrogradation analysis by DSC, the test delayed slightly compared to the control.

The Anticancer Effects and Drug Metabolic Enzyme Change by Oral Intake of Agrimonia Pilosa Ledeb (선학초(짚신나물) 경구투여시 항암효과 탐색 및 약물 대사효소의 변화)

  • Rhee, Si-Hyung;Jung, Hee;Lee, Ju-Ah;Go, Ho-Yeon;Choi, Yu-Kyung;Park, Jong-Hyung;Kim, Ji-Hye;Ko, Seong-Kyu;Jun, Chan-Yong
    • Journal of Society of Preventive Korean Medicine
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    • v.13 no.2
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    • pp.51-64
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    • 2009
  • Objective : This research was aimed to investigate the anti-tumor effect, safety, mechanism and metabolizing enzyme of Agrimonia pilosa LEDEB(APL) in female C57B/L mouse. Methods : At first, to evaluate the anti-tumor activity of APL, we divided into four groups, normal, control, APL100(100mg/kg), APL150(150mg/kg). LLC obtained American Type Culture Collection was used. LLC had been inoculated to induce tumor. To measure the anti-tumor effect of APL, we calibrate tumor size and weight. To study for mechanism of anti-tumor in APL, we used western blotting and to know metabolizing enzyme in APL we used to real-time PCR. Results : APL100, APL150 inhibited tumor growth after medicine injected. APL did not only induced caspase-dependent apoptosis in LLC-bearing mouse tumor. In APL100, it were decreased 72% in CYP3A11. In APL150, it were decreased 62%, 75% in CYP3A11 and MRP1a respectively. Conclusion : These results suggests that APL has some anti-tumor effects in female C57B/L mouse tumor. APL should be careful use with other drugs related with CYP3A11 or MRP1a.

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