• 제목/요약/키워드: $L^1$-convergence

검색결과 663건 처리시간 0.02초

인체 흉부 영상 복원을 위한 행렬 적응 조정 방법의 적용 (Application of Matrix Adaptive Regularization Method for Human Thorax Image Reconstruction)

  • 전민호;김경연
    • 전기전자학회논문지
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    • 제19권1호
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    • pp.33-40
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    • 2015
  • 전기 임피던스 단층촬영법(EIT)에서 역문제는 매우 높은 비정치성이므로 이것을 완화시키기 위해서 사전정보가 사용되고 EIT 역문제를 푸는 과정에서 만족스러운 복원성능을 갖기 위해 조정 기법은 적용된다. 반복적 Gauss-Newton 방법은 정확성과 빠른 수렴속도로 인해서 일반적으로 역문제를 푸는데 사용되지만 항상 좋은 성능을 내는 것은 아니며 조정 인자 선택에 따라 성능이 좌지우지된다. 비록 L-곡선과 같이 조정 인자를 결정하는데 이용할 수 있는 여러 가지 방법들이 존재하지만 이러한 방법들이 모든 경우에 적용할 수 있는 것은 아니다. 게다가 조정 인자는 스칼라이고 반복 연산동안 변하지 않는다. 그러므로 이 논문에서는 복원 성능을 향상시키기 위해서 조정 인자를 결정해주는 새로운 방법을 사용하였다. 각각의 반복 연산과정에서 도전율의 norm을 구하고 이것을 대각 행렬형태인 조정 인자를 구하는데 사용한다. 제안한 방법을 인체 흉부 영상 복원에 적용하였고, 기존의 방법들과 복원 성능을 비교하였다. 모의실험 결과, 기존의 방법들과 비교해서 개선된 성능을 확인할 수 있었다.

LPS로 유도된 RAW 264.7 대식세포에서 청대의 항염증효과 (Anti-Inflammatory Effect of Chung-Dae in LPS-Treated RAW 264.7 Cells)

  • 장수주;강순아
    • 한국식품영양학회지
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    • 제35권2호
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    • pp.116-126
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    • 2022
  • The purpose of this study was to analyze the anti-inflammatory effect of Chung-Dae Indigo Pulverata Levis, indigo naturalis) produced during indigo dyeing. As a result of in vitro cytotoxicity experiments using RAW 264.7 cell, Chung-Dae extract did not inhibit cell proliferation in Raw 264.7 cells in the range of 1~32 ㎍/mL. NO production was significantly reduced when Chung-Dae extracts were treated at concentrations of 2, 8, and 32 ㎍/mL (p<0.05). The pro-inflammatory cytokines TNF-α, IL-6, IL-1β and IFN-γ significantly decreased when the Chung-Dae extract was treated at concentrations of 2, 8, and 32 ㎍/mL compared to the LPS group, and similarly, the TNFα and IL-6 mRNA levels also decreased. Additionally, the mRNA level of COX-2 was also suppressed. At the protein expression level, the expression of TNF-α, IL-6, iNOS and COX-2 were observed with LPS and Chung-Dae extract significantly decreased compared to the group treated with only LPS (p<0.05). From the above results, it shows that Chung-Dae extract, a plant-derived compound, inhibits the inflammatory response induced by LPS in RAW 264.7 cells. and in particular, regulates the inflammatory response by inhibiting the expression of pro-inflammatory cytokines and inflammation-related enzymes.

Constitutive Activating Eel Luteinizing Hormone Receptors Induce Constitutively Signal Transduction and Inactivating Mutants Impair Biological Activity

  • Byambaragchaa, Munkhzaya;Choi, Seung-Hee;Kim, Dong-Wan;Min, Kwan-Sik
    • 한국발생생물학회지:발생과생식
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    • 제25권3호
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    • pp.133-143
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    • 2021
  • In contrast to the human lutropin receptor (hLHR) and rat LHR (rLHR), very few naturally occurring mutants in other mammalian species have been identified. The present study aimed to delineate the mechanism of signal transduction by three constitutively activating mutants (designated M410T, L469R, and D590Y) and two inactivating mutants (D383N and Y546F) of the eel LHR, known to be naturally occurring in human LHR transmembrane domains. The mutants were constructed and measured cyclic adenosine monophosphate (cAMP) accumulation via homogeneous time-resolved fluorescence assays in Chinese hamster ovary (CHO)-K1 cells. The activating mutant cells expressing eel LHR-M410T, L469R, and D590Y exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response without agonist treatment, respectively. However, inactivating mutant cells expressing D417N and Y558F did not completely impaired signal transduction. Specifically, signal transduction in the cells expressing activating mutant L469R was not occurred with a further ligand stimulation, showing that the maximal response exhibited approximately 53% of those of wild type receptor. Our results suggested that the constitutively activating mutants of the eel LHR consistently occurred without agonist treatment. These results provide important information of LHR function in fish and regulation with regard to mutations of highly conserved amino acids in glycoprotein hormone receptors.

Green synthesis of fluorescent carbon dots from carrot juice for in vitro cellular imaging

  • Liu, Yang;Liu, Yanan;Park, Mira;Park, Soo-Jin;Zhang, Yifan;Akanda, Md Rashedunnabi;Park, Byung-Yong;Kim, Hak Yong
    • Carbon letters
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    • 제21권
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    • pp.61-67
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    • 2017
  • We report the use of carrot, a new and inexpensive biomaterial source, for preparing high quality carbon dots (CDs) instead of semi-conductive quantum dots for bioimaging application. The as-derived CDs possessing down and up-conversion photoluminescence features were obtained from carrot juice by commonly used hydrothermal treatment. The corresponding physiochemical and optical properties were investigated by electron microscopy, fluorescent spectrometry, and other spectroscopic methods. The surfaces of obtained CDs were highly covered with hydroxyl groups and nitrogen groups without further modification. The quantum yield of as-obtained CDs was as high as 5.16%. The cell viability of HaCaT cells against a purified CD aqueous solution was higher than 85% even at higher concentration ($700{\mu}g\;mL^{-1}$) after 24 h incubation. Finally, CD cultured cells exhibited distinguished blue, green, and red colors, respectively, during in vitro imaging when excited by three wavelength lasers under a confocal microscope. Offering excellent optical properties, biocompatibility, low cytotoxicity, and good cellular imaging capability, the carrot juice derived CDs are a promising candidate for biomedical applications.

Phellinus linteus KACC 93057P, '한경상황버섯'인공재배 자실체 페놀추출물의 항산화 활성 및 화학적 동정 (Chemical identification and antioxidant activity of phenolic compounds extracted from the fruiting body of 'Hankyong Sanghwang', Phellinus linteus KACC 93057P)

  • 민경진;정이은;윤봉식;강희완
    • 한국버섯학회지
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    • 제16권4호
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    • pp.311-317
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    • 2018
  • 참나무 단목원목으로 재배한 P. linteus KACC93057P(PLHS)2년산 자실체 60%에탄올 추출물의 총 페놀함량은 $19.05{\pm}0.32mg\;GAE/g$로 다른 비교구 버섯 종에 비하여 4배에서 10배이상의 높게 나타났다. $125{\mu}g/mL$농도에서 DPPH와 ABTS 라디칼 소거능은 62%와 100%를 나타냈으며 FRAP 환원력은 $0.7{\mu}MFeSO_4/g$으로 비교 구 버섯종 보다 2에서 10배이상의 유효활성이 검출 되었다. PLHS 자실체 ethyl acetate분배 추출물의 HPLC분석에서 styrylpyrone 계열의 화합물 davallialactone, hispidin, hypholomine B와 phenylpropanoid 계열의 화합물인 caffeic acid가 동정 되었다.

호흡기를 통한 약액 전달을 위한 진세노사이드 초미세입자 분무장치 제작 (Fabrication of an ultra-fine ginsenoside particle atomizer for drug delivery through respiratory tract)

  • 이병철;박진수;양웅모
    • 대한융합한의학회지
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    • 제2권1호
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    • pp.5-12
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    • 2021
  • Objectives: The purpose of this study is to fabricate an ultra-fine ginsenoside particle atomizer that can provide a new treatment method by delivering ginsenoside components that have a therapeutic effect on respiratory diseases directly to the lungs. Methods: We fabricated the AAO vibrating mesh by using the micromachining process. The starting substrate of an AAO wafer has a 350nm pore diameter with 50㎛ thickness. A photomask having several 5㎛ opening holes with a 100㎛ pitch was used to separate each nanopore nozzle. The photoresist structure was optimized to pattern the nozzle area during the lift-off process precisely. The commercial vibrating mesh was removed from OMRON's NE-U100 product, and the fabricated AAO vibrating mesh was installed. A diluted sample of 20mL with 30% red ginseng concentrate was prepared to atomize from the device. Results: As a result of liquid chromatography analysis before spraying the ginsenoside solution, ginsenoside components such as 20S-Rg3, 20R-Rg3, and Rg5 were detected. After spraying through the AAO vibrating mesh, ginsenosides of the same component could be detected. Conclusion: A nutrient solution containing ginsenosides was successfully sprayed through the AAO vibrating mesh with 350 nm selective pores. In particular, during the atomizing experiment of ginsenoside drug solution having excellent efficacy in respiratory diseases, it was confirmed that atomizing through the AAO vibrating mesh while maintaining most of the active ingredients was carried out.

산수유(Corni fructus) 분획 추출물의 항산화 활성 및 RAW 264.7 대식세포에서 염증매개물질 억제 효과 (Antioxidant activity and suppression of pro-inflammatory mediator of Corni fructus extracts in activated RAW 264.7 macrophage)

  • 김예진;손대열
    • 한국식품저장유통학회지
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    • 제23권6호
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    • pp.876-882
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    • 2016
  • 산수유에 함유된 유효성분을 극성이 다른 용매로 계통분획하여 얻은 추출물(water 분획물, CWF; EtOAc 분획물, CEF; butanol 분획물, CBF)의 항산화활성및 항염증 효과를 확인하였다. 그 결과, 모든 분획물은 농도가 증가함에 따라 자유 라디칼 소거능이 증가하였으며, 특히 가장 높은 폴리페놀 함량(179.3 mg TAE/g)이 확인된 CEF의 경우 대조군으로 사용된 BHA와 ${\alpha}-tocopherol$보다 뛰어난 자유 라디칼 소거활성(DPPH: $RH_{50}$; $25.1{\mu}g/mL$, ABTS: $RC_{50}$; $36.1{\mu}g/mL$)이 확인되다. Mouse macrophage RAW 264.7 cell을 사용하여 NO, $PGE_2$ 및 염증성 사이토카인($TNF-{\alpha}$, $IL-1{\beta}$, IL-6)의 생성억제 측정을 통한 항염증 효과 분석 결과, 산수유 분획물(CWF, CEF, CBF)은 용매에 따른 유의적 차이 없이 처리농도 범위($1{\sim}100{\mu}g/mL$)에서 NO, $PGE_2$ 및 염증성 cytokine 생성을 유의적으로 억제하였다. CWF와 CEF는 농도 의존적으로 NO 생성을 억제하였으며, $100{\mu}g/mL$ 농도에서 CWF($0.5{\mu}M$)와 CEF($1.2{\mu}M$)는 LPS 비처리군과 유사하게 NO 생성을 억제하였다. $100{\mu}g/mL$ 농도에서 가장 높은 염증성 cytokine 생성 억제 효과는 CWF가 $TNF-{\alpha}$의 생성을 51.2%, CEF가 $IL-1{\beta}$와 IL-6의 생성을 각각 67%와 58% 억제하여, 산수유 분획물의 뛰어난 항염증 효과가 확인되었다.

몬테카를로 시뮬레이션을 이용한 복숭아의 방사선 조사 (Monte Carlo Simulation of Irradiation Treatment of Peaches (Prunus persica L. Batsch))

  • 김종순;김동현;박종민;최원식;권순홍
    • 한국산업융합학회 논문집
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    • 제21권6호
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    • pp.337-344
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    • 2018
  • Food irradiation is important not only in ensuring safety but also improving antioxidant activity of peaches. Our objective was to establish the best irradiation treatment for peaches by calculating dose distribution using Monte Carlo simulation. 3-D geometry and component densities of peaches, extracted from CT scan, were entered into MCNP to obtain simulated dose distribution. Radiation energies for electron beam were 1.35 MeV (low energy) and 10 MeV (high energy). Co (1.25 MeV) and the Husman irradiator, containing three sealed Cs source rods in an annular array, were used for gamma irradiation. At 1.35 MeV electron beam simulation, electrons penetrated well beyond the peach skin, enough for surface treatment for microorganisms and allergens. At 10 MeV electron beam simulation, for top-beam only treatment, doses at the core were the highest and for double beam treatment, the electron energy was absorbed by the entire sample. At Co source, the radiation doses were presented on the whole area. At Cs source, the dose uniformity ratios were 2.78 for one source and 1.48 for three ones at 120 degrees interval. Proper control of irradiation treatment is critical to establish confidence in the irradiation process.

Kiwi-persimmon wine produced using wild Saccharomyces cerevisiae strains with sugar, acid, and alcohol tolerance

  • Hee Yul Lee;Kye Man Cho;Ok Soo Joo
    • 한국식품저장유통학회지
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    • 제30권1호
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    • pp.52-64
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    • 2023
  • 100 different yeast colonies were isolated from spontaneously fermented kiwis, persimmons, apples, pears, watermelons, grapes, grape fruits, peachs, and plums, and selected yeast strains were used to produce kiwi-persimmon mixed wine (KPMW). Among the isolates, five representative strains exhibited tolerance to sucrose, alcohol, pH, and potassium metabisulfite when compared with the control yeast strain (Saccharomyces cerevisiae KCCM 12615). All five yeast strains (Y4, Y10, Y28, Y78, and Y81) exhibited 99% 26S rDNA sequence similarity to S. cerevisiae. The pH, acidity, Brix, reducing sugar, alcohol, and organic acid contents were consistent in KPMW prepared from the S. cerevisiae KCCM 12615 and Y28 strains. KPMW made from the Y4, Y10, and Y28 strains exhibited lower quantities of free sugars than those of the KPMW made from the other yeast strains. The level of ethyl esters in KPMW prepared from the Y28 was higher than that in the other KPMWs. All strains, except for Y28, produced lower concentrations of sulfur and ketone compounds. Furthermore, the KPMW produced by the Y28 strains had total phenolic contents with 1.1 g/L, with DPPH and ABTS radical scavenging activities of 57.06% and 55.62%, respectively, and a FRAP assay value of 0.72. Our results suggest that Y28 is a promising yeast strain for producing high-quality wines.