• Title/Summary/Keyword: auxiliary cells

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Fine Needle Aspiration Cytology of Two Cases of Leiomyosarcoma (평활근육종의 세침 흡인 세포학적 소견 -2예 보고-)

  • Ha, Chang-Won;Myong, Na-Hye;Cho, Kyung-Ja;Jang, Ja-June
    • The Korean Journal of Cytopathology
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    • v.1 no.2
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    • pp.147-151
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    • 1990
  • Leiomyosarcoma of the soft tissue is a well-defined and characteristic entity histologically, but cytomorphological studes are lacking. A correlaive cytological study of 2 cases of leiomyosarcoma is presented. The smears from case 1 were rich in tumor cells and most cells were arranged in large sheets or clusters. The cells showed round to oval nuclei containing fine chromatin and small promiment nucleoli. The smears from case 2 were moderate in cellularity with loose clusters or isolated cells. The characteristic blunt-ended and cigar-shaped nuclei containing coarse chromatin and prominent nucleoli were identified in case 2. Nuclear atypia, prominent nucleoli and high cellularity permit diagnosis of malignancy, although the atypia is generally less pronounced than in the histology. The cytological diagnosis of leiomyosarcoma may be auxiliary in the diagnosis of recurrence or metastasis in the patients with alleged leiomyosarcoma.

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A New Photovoltaic System Architecture of Module-Integrated Converter with a Single-sourced Asymmetric Multilevel Inverter Using a Cost-effective Single-ended Pre-regulator

  • Manoharan, Mohana Sundar;Ahmed, Ashraf;Park, Joung-Hu
    • Journal of Power Electronics
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    • v.17 no.1
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    • pp.222-231
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    • 2017
  • In this paper, a new architecture for a cost-effective power conditioning systems (PCS) using a single-sourced asymmetric cascaded H-bridge multilevel inverter (MLI) for photovoltaic (PV) applications is proposed. The asymmetric MLI topology has a reduced number of parts compared to the symmetrical type for the same number of voltage level. However, the modulation index threshold related to the drop in the number of levels of the inverter output is higher than that of the symmetrical MLI. This problem results in a modulation index limitation which is relatively higher than that of the symmetrical MLI. Hence, an extra voltage pre-regulator becomes a necessary component in the PCS under a wide operating bias variation. In addition to pre-stage voltage regulation for the constant MLI dc-links, another auxiliary pre-regulator should provide isolation and voltage balance among the multiple H-bridge cells in the asymmetrical MLI as well as the symmetrical ones. The proposed PCS uses a single-ended DC-DC converter topology with a coupled inductor and charge-pump circuit to satisfy all of the aforementioned requirements. Since the proposed integrated-type voltage pre-regulator circuit uses only a single MOSFET switch and a single magnetic component, the size and cost of the PCS is an optimal trade-off. In addition, the voltage balance between the separate H-bridge cells is automatically maintained by the number of turns in the coupled inductor transformer regardless of the duty cycle, which eliminates the need for an extra voltage regulator for the auxiliary H-bridge in MLIs. The voltage balance is also maintained under the discontinuous conduction mode (DCM). Thus, the PCS is also operational during light load conditions. The proposed architecture can apply the module-integrated converter (MIC) concept to perform distributed MPPT. The proposed architecture is analyzed and verified for a 7-level asymmetric MLI, using simulation results and a hardware implementation.

Usefulness of p16INK4a Immunocytochemical staining for the Differentiation between Atrophy and ASCUS in Diagnosis of Uterine Cervical Cancer

  • Hye Ryoung Shin;Taekil Eom;Wan-Su Choi
    • Biomedical Science Letters
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    • v.29 no.3
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    • pp.144-151
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    • 2023
  • A Pap smear is the most important screening test for the diagnosis of cervical cancer. However, subjective judgment by the operator cannot be excluded, and replicability may greatly be reduced if uncertain specimens are examined. Examiners often experience difficulties in differentiating atrophy with inflammatory changes and ASCUS when diagnosing squamous epithelial lesions from a pap smear. Reports often vary between cytologists and pathologists, and misdiagnosis may result in delayed follow-ups and advanced diseases. Hence, auxiliary examinations are necessary when confusing results between atrophy and ASCUS are obtained. The importance of p16INK4a activation due to HPV infection, which is an important factor in the outbreak of cervical cancer, has been highlighted. Recent studies have reported that p16INK4a immunocytochemical staining and HPV high-risk type tests using liquid-based cervical specimens are effective to detect the presence of lesions of grade HSIL or higher in patients with ASC-H. However, no research exists on the utility of HPV and p16INK4a tests on the differential diagnosis of atrophy and ASCUS. This study focused on whether p16INK4a immunocytochemical staining and HPV tests can help diagnose borderline lesions between atrophy and ASCUS. The results reported that p16INK4a activation can significantly (P<0.001) differentiate atrophy from ASCUS in atrophic lesions infected with High risk-HPV. Therefore, it may be concluded that p16INK4a immunocytochemical staining is an effective auxiliary test in lesions infected with HR-HPV when atrophic lesions are difficult to differentiate by morphology. Such results are expected to help decide on adequate follow-up and treatment.

Enhanced UV-Visible Absorbance Detection in Capillary Electrophoresis Using Modified T-Shaped Post-Column Flow Cell

  • Lim, Kwan-Seop;Kim, Su-Hyeon;Hahn, Jong-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.295-300
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    • 2002
  • The construction of the T-shaped post-column flow cell has been changed to enhance the practicability as a UV-visible absorbance detector for capillary electrophoresis. In this new design, a rectangular cube-shaped inner structure is employed, which completely fits the outer rectangular tubing. This arrangement has greatly facilitated the fabrication of the T-cells. In addition, the volume for the auxiliary flow has been dramatically reduced down to 300 ${\mu}L$, and its volume flow rate is optimized at 4.2 ${\mu}L$/min. The short optical path length in the sheath flows (500 ${\mu}m$ on each side) minimizes background absorption, and thus enhances its performance in low-UV wavelengths. We have optimized the auxiliary flow rate at 50 ${\mu}m$/s, so that migration times are insensitive to the flow rate. This optimization has improved repeatabilities in migration times and peak heights. A double-beam detection scheme using a pair of photodiodes is employed to increase the signal-to-noise ratio.

High Luminous Efficiency Flat Light Source with Xe mixture Gas Discharge and Areal Brightness Control Method (제논 혼합가스를 이용한 고효율 면광원과 국부적 밝기 제어 방식)

  • Jung, Jae-Chul;Seo, In-Woo;Oh, Byung-Joo;Whang, Ki-Woong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.153-157
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    • 2009
  • A Highly efficient Mercury-free Flat Fluorescent Lamp (MFFL) with dielectric barrier Xe gas discharge was developed for an alternative of conventional line-type Cold Cathode Fluorescent Lamps (CCFLs) which shows a wide voltage margin and a stable discharge operation for diffuse glow discharge with an application of a auxiliary electrode. Electro-optic characteristics of the MFFL were examined through the changes in ambient temperature, total pressure and Xe partial pressure. the single cell is expanded into a multi-structured configuration to realize a large sized lamp by a simple repetition of the single cells, and a new driving scheme is proposed for an adaptive brightness control using dual auxiliary electrodes and bi-polar drive scheme. In addition, interesting application of this ultra high luminance flat lamp by the optimization of the gas condition and the pattern of the rear phosphor layer is suggested as a good alternative of daylight lamp source

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Improved Bridgeless Interleaved Boost PFC Rectifier with Optimized Magnetic Utilization and Reduced Sensing Noise

  • Cao, Guoen;Kim, Hee-Jun
    • Journal of Power Electronics
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    • v.14 no.5
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    • pp.815-826
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    • 2014
  • An improved bridgeless interleaved boost power factor correction (PFC) rectifier to improve power efficiency and component utilization is proposed in this study. With combined conventional bridgeless PFC circuit and interleaved technology, the proposed rectifier consists of two interleaved and magnetic inter-coupling boost bridgeless converter cells. Each cell operates alternatively in the critical conduction mode, which can achieve the soft-switching characteristics of the switches and increase power capacity. Auxiliary blocking diodes are employed to eliminate undesired circulating loops and reduce current-sensing noise, which are among the serious drawbacks of a dual-boost PFC rectifier. Magnetic component utilization is improved by symmetrically coupling two inductors on a unique core, which can achieve independence from each other based on the auxiliary diodes. Through the interleaved approach, each switch can operate in the whole line cycle. A simple control scheme is employed in the circuit by using a conventional interleaved controller. The operation principle and theoretical analysis of the converter are presented. A 600 W experimental prototype is built to verify the theoretical analysis and feasibility of the proposed rectifier. System efficiency reaches 97.3% with low total harmonic distortion at full load.

A High Efficiency Zero Voltage/Zero Current Transition Converter for Series Connected Battery Cell Equalization (영전압/영전류 스위칭을 이용한 고효율의 직렬 접속 배터리 전압 밸런싱 방법)

  • Kim, Tae-hoon;Park, Nam-Ju;Hyun, Dong-seok;Kim, Rae-young
    • Proceedings of the KIPE Conference
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    • 2011.11a
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    • pp.26-27
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    • 2011
  • This paper focuses on the zero-voltage/zero current transition voltage equalization circuit for the series connected battery cell. By adding auxiliary resonant cells at the main switching devices such as MOSFET or IGBT, zero current switching is achieved and turned off loss of switching elements is eliminated and by the voltage/second balancing of the inductor, zero voltage switching can be applied to switching element. Transformer coupling between battery cells and ZVZCT (Zero Voltage Zero Current Transition) switching method allow the fast balancing speed and high frequency operation, which reduces the size and weight of the circuit. The validity of the battery equalization is further verified using simulation involving four lithium-ion battery cell models.

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DEVELOPMENT OF HOT CELL FACILITIES FOR DEMONSTRATION OF ACP

  • You, Gil-Sung;Choung, Won-Myung;Ku, Jeong-Hoe;Cho, Il-Je;Kook, Dong-Hak;Park, Seong-Won
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.02a
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    • pp.191-204
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    • 2004
  • The research and development of effective management technologies of the spent fuels discharged from power reactors are an important and essential task of KAERI. In resent several years KAERI has focused on a project named "development and demonstration of the Advanced spent fuel Conditioning Process (ACP) in a laboratory scale." The Facility for ACP demonstration consists of two Hot Cells and auxiliary facilities. It is now in the final design stage and will be constructed in 2004. After construction of the facility the ACP equipments will be installed in Hot Cells. The ACP will be demonstrated by some simulated spent fuels first and then by spent fuels.

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Mitochondrial DNA Somatic Mutation in Cancer

  • Kim, Aekyong
    • Toxicological Research
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    • v.30 no.4
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    • pp.235-242
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    • 2014
  • Cancer cells are known to drastically alter cellular energy metabolism. The Warburg effect has been known for over 80 years as pertaining cancer-specific aerobic glycolysis. As underlying molecular mechanisms are elucidated so that cancer cells alter the cellular energy metabolism for their advantage, the significance of the modulation of metabolic profiles is gaining attention. Now, metabolic reprogramming is becoming an emerging hallmark of cancer. Therapeutic agents that target cancer energy metabolism are under intensive investigation, but these investigations are mostly focused on the cytosolic glycolytic processes. Although mitochondrial oxidative phosphorylation is an integral part of cellular energy metabolism, until recently, it has been regarded as an auxiliary to cytosolic glycolytic processes in cancer energy metabolism. In this review, we will discuss the importance of mitochondrial respiration in the metabolic reprogramming of cancer, in addition to discussing the justification for using mitochondrial DNA somatic mutation as metabolic determinants for cancer sensitivity in glucose limitation.

Effects of immune-challenged domestic silkworm hemolymph on the regulation of SIRT5 and PRDx1 expression

  • Jin Ha Yun;Seong Ryul Kim;Seung-Won Park
    • International Journal of Industrial Entomology and Biomaterials
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    • v.47 no.2
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    • pp.134-139
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    • 2023
  • SIRT5 and PRDx1 play crucial roles in cancer and are involved in the basic mechanisms of reactive oxygen species detoxification. In our previous studies, we showed that hemolymph extracts of immune-challenged Bombyx mori have antioxidant properties. Following H2O2 stimulation, immune-challenged B. mori hemolymph extracts elicited SIRT5 downregulation activity, reaching effective activity at the highest concentration of 100 ppm. Additionally, cells treated with immune-challenged B. mori hemolymph extracts demonstrated increased PRDx1 mRNA expression compared to that of PBS-treated cells. Therefore, immune-challenged B. mori hemolymph extracts offer a potential auxiliary means of treating drug-resistant tumors through downregulation of SIRT5 and upregulation of PRDx1 expression. Nevertheless, further studies on the effects of B. mori hemolymph on SIRT5 and PRDx1 regulation are pertinent for using it as a food or pharmaceutical material and understanding its therapeutic effect on tumors, including those that are drug-resistant.