• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.4
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• pp.247-255
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• 2018

This paper proposes a transformer design of a direct cell-to-cell active cell balancing circuit with a multi-winding transformer for battery management system (BMS) applications. The coupling coefficient of the multi-winding transformer and the output capacitance of MOSFETs significantly affect the balancing current transfer efficiency of the cell balancing operation. During the operation, the multi-winding transformer stores the energy charged in a specific source cell and subsequently transfers this energy to the target cell. However, the leakage inductance of the multi-winding transformer and the output capacitance of the MOSFET induce an abnormal energy transfer to the non-target cells, thereby degrading the transfer efficiency of the balancing current in each cell balancing operation. The impacts of the balancing current transfer efficiency deterioration are analyzed and a transformer design methodology that considers the coupling coefficient is proposed to enhance the transfer efficiency of the balancing current. The efficiency improvements resulting from the selection of an appropriate coupling coefficient are verified by conducting a simulation and experiment with a 1 W prototype cell balancing circuit.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.3
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• pp.253-258
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• 1995

Microtubules and microfilaments are major cytoskeletal components in mammalian ova that provide the framework for chromosomal movement and cellular division. Extensive changes of cytoskeletal organization occur during maturation and fertilization. The changes in cytoskeletons are essential for the normal meiotic maturation and for the formation of the biparental diploid genome of the embryo, and thus are repeated at each cell cycle during embryonic development. Disturbance of the cytoskeletal organization could result in abnormal gamete development and early embryonic death.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.1
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• pp.1-7
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• 2017

The task force of the Korean Society for Reproductive Immunology recommends intravenous immunoglobulin G treatment in women with reproductive failure, including recurrent pregnancy loss and/or repeated implantation failure, who show cellular immune factors such as abnormal natural killer cell levels, natural killer cell cytotoxicity, and/or type 1 T helper immunity.

• Reproductive and Developmental Biology
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• v.33 no.4
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• pp.195-202
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• 2009

Abnormal development and fetal loss during the post-implantation period are key concerns in the production of cloned animals by somatic cell nuclear transfer (SCNT). We hypothesized that the problems in cloned porcine offspring derived from SCNT are related to interactions between the conceptus and the endometrial environment. In the present study, we investigated expression patterns in the formation of placenta-related genes (Cdx2 and GATA6) in whole in vivo normal porcine embryos (from single cell to blastocyst) and each tissue of a normal fetus at Days 25, 35 and 55 by quantitative mRNA expression analysis using real-time PCR. The expression of Cdx2 and GATA6 mRNA increased to around the blastocyst stage. These genes were gradually decreased from the peri-implantation to post-implantation stage. Moreover, we examined the expression patterns of Cdx2 and GATA6 in Day 35 normal and SCNT cloned fetuses by the same methods. And, the level of Cdx2 and GATA6 gene expression in the extraembryonic tissue of SCNT was significantly higher than that of control tissues. From the present results, it can be postulated that the aberrant expression of Cdx2 and GATA6 genes in the endometrial and extraembryonic tissues at pre- and peri-implantation stages may be closely related to the lower efficiency of animal cloning.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7415-7419
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• 2013

The diagnosis of latent Mycobacterium tuberculosis infection (LTBI) is recommended in hematological malignancy patients and before hematopoietic stem cell transplantation (Guidelines for the prevention and management of infectious complications of solid organ transplantation, 2004). Compared to traditional methods such as tuberculin skin test (TST), T-SPOT.TB has been shown to be more specific. In the present study we enrolled 536 patients for whom T-SPOT.TB was performed, among which 295 patients also received the TST test. The agreement (79%) between T-SPOT.TB and TST was poor (x=0.274, P<0.001). The patients with positive T-SPOT.TB results numbered 62 (11.6%), in which only 20 (48.8%) of the 41 receiving the TST test had positive results. A majority of the patients with T-SPOT.TB positive results had some other evidence ofTB, such as TB history, clinical symptoms and an abnormal chest CT scan. Active TB was found in 9 patients, in which 2 had negative TST results. We followed up the patients and no one developed active TB. Our study suggested that the T-SPOT.TB may be more useful for screening LTBI and active TB in hematological malignancy patients and hematopoietic stem cell transplant recipients than the TST test.

• Anatomy and Cell Biology
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• v.56 no.1
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• pp.155-159
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• 2023

Studies describing the vascular systems and their variations in Situs inversus totalis (SIT) from a whole-body computed tomographic (CT) angiography perspective are lacking. We report a case of SIT in which postmortem CT angiography (PMCTA) was performed as a part of the forensic death investigation and incidentally detected several vascular variations in it. The PMCTA procedure was performed using the multiphase PMCTA protocol. Almost all major vessels were visualized, indeed in a completely reversed pattern. Contrast mixture flow interruptions were noted in the right coronary arterial branches suggesting possible blockage, upon which autopsy revealed >90% vessel occlusions at several locations. As such the cause of death was due to ischemic heart disease. Anomalous origins of the right internal mammary artery; abnormal left thyrocervical trunk and variations in the drainage of testicular veins were noted. Our findings might be helpful to clinicians and add to the body of literature on SIT.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.874-879
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• 2008

Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be reduced by treatment with depigmenting agents. The methanol extract of Lespedeza cyrtobotrya $M_{IQ}$ showed inhibitory activity against mushroom tyrosinase. The active compound was purified from the methanol extract of L. cyrtobotrya, followed by several chromatographic methods, and identified as dalbergioidin (DBG) by spectroscopic methods. The results showed that DBG exhibited tyrosinase inhibitory activity with an $IC_{50}$ of $20\;{\mu}M$. The kinetic analysis of tyrosinase inhibition revealed that DBG acted as a noncompetitive inhibitor. In addition, DBG showed a melanin biosynthesis inhibition zone in the culture plate of Streptomyces bikiniensis that has commonly been used as an indicator organism. Furthermore, $27\;{\mu}M$ DBG decreased more than 50% of melanin contents on the pigmentation using the immortalized mouse melanocyte, melan-a cell.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.2
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• pp.33-42
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• 2011

Zinc plays a key role in genetic expression, cell division, and cell growth and is essential for the functions of more than 450 metalloenzyme. There are high concentrations of zinc in pigment epithelium in bullfrog eye. Zinc deficiency causes night blindness and abnormal dark adaptation. The purpose of this study was to identify ERG (electroretinogram) b-wave sensitivity during light and dark adaptation in bullfrog retina after zinc and zinc chelators treatment such as histidine and TSQ (N-(6-methoxy-8-qunolyl)-p-toluenesulfon amide). Especially, we focused whether histidine act as a zinc chelator in the Muller cell. The results of our study are summarized as follows: 1) Both zinc and histidine elevated ERG b-wave amplitude and threshold in Muller cells by accelerating rhodopsin regeneration time and increased a-peak absorbance during light adaptation. 2) TSQ reduced those by prolonging rhodopsin regeneration time and decrement of a-peak absorbance during light adaptation. 3) Zinc shortened rhodopsin regeneration time and prolonged a-peak absorbance. These results suggested that histidine may act as a zinc-mediated transporter in presynaptic Muller cell membrane rather than zinc chelator and acts as a GABA-receptor inhibitor which blocks $Cl^-$ influx to the postsynapse.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.443-451
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• 2001

In order to investigate what kind of response anaerobic bifidobacteria has on oxygen stress, five oxygen-tolerant bifidobacteria were isolated from human fecal samples. All were temporarily identified as Bifidobacterium longum through an analysis of carbohydrate utilization patterns and cellular fatty acid profiles. In the presence of oxygen, the lag phase became extended and the cell growth was suppressed. Bifidobacterial cell was able to remove dissolved oxygen in an early stage of growth and to overcome oxygen stress to a certain extent. The cell became long n size and showed a rough surface containing many nodes which were derived from abnormal or incomplete cell division. Cellular fatty acid profiled changed remarkably under a partially aerobic condition, so that the carbon chain of cellular fatty acid became short. All the dimethyl acetals originated from plasmalogen were reduced, any cyclopropane fatty acid, 9, 10-methyleneoctadecanoic acid ($C_{19:0}cyc9,10$), was increased remarkably. Oxygen stress induced a 5.5 kD protein in B. longum JI 1 of the oxygen-teolerant bifidobacteria, that was named Osp protein, and its N-terminal amino acid sequence was as follows: unknown amino acid-Thr-Gly-Val-Arg-Phe-Ser-Asp-Asp-Glu. Therefore, the oxygen-tolerant bifidobacteria seemed to defend against oxygen stress byincreasing the content of short fatty acid and cyclopropane fatty acid, and induction of an oxygen stress protein, but not the plasmalogen.

• Genomics & Informatics
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• v.8 no.3
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• pp.122-130
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• 2010

Abnormal hematological values are associated with various disorders including cancer and cardiovascular, metabolic, infectious, and immune diseases. We report the copy number variations (CNVs) in clinically relevant hematological parameters, including hemoglobin level, red and white blood cell counts, platelet counts, and red blood cell (RBC) volume. We describe CNVs in several loci associated with these hematological parameters in 8,842 samples from Korean population-based studies. The data that we evaluated included four RBC parameters, one platelet parameter, and one associated with total white blood cell (WBC) count, exceeding the genome-wide significance. We show that CNVs in hematological parameters are associated with some loci, different from previously associated loci reported in single nucleotide polymorphism (SNP) association studies.