• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.161-168
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• 2017

In this study, we examined the effect of Perilla frutescens extract (PFE) on oxidative stress-induced cell death in RGC-5 cell lines. Staurosporine-differentiated RGC-5 (ssdRGC-5) cells obtained by treating RGC-5 cells with $1{\mu}M$ staurosporine were incubated with PFE for 30 min and then exposed to buthionine sulfoximine plus glutamate (B/G) for 20 h. Cell death was detected using lactate dehydrogenase release assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. To investigate the mechanism underlying cell death, we determined caspase-3 activity, level of reactive oxygen species (ROS) formation, and expression levels of cytoplasmic cytochrome c and mitochondrial Bax. Treatment of ssdRGC-5 cells with B/G increased intracellular ROS and induced apoptosis with increasing caspase-3 activity. PFE rescued ssdRGC-5 cells from oxidative stress-induced cell death by inhibiting intracellular ROS production and caspase-3 activation and regulating apoptosis-related proteins such as cytochrome c and Bax. These findings suggest that PFE may have a beneficial neuroprotective effect against oxidative stress-induced apoptotic death in ssdRGC-5 cells.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.331-344
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• 2011

The well-conserved NBS domain of resistance (R) genes cloned from many plants allows the use of a PCR-based approach to isolate resistance gene analogs (RGAs). In this study, we isolated an RGA (CapRGC) from Capsicum annuum "CM334" using a PCR-based approach. This sequence encodes a protein with very high similarity to Rx genes, the Potato Virus X (PVX) R genes from potato. An evolutionary analysis of the CapRGC gene and its homologs retrieved by an extensive search of a Solanaceae database provided evidence that Rx-like genes (eight ESTs or genes that show very high similarity to Rx) appear to have diverged from R1 [an NBS-LRR R gene against late blight (Phytophthora infestans) from potato]-like genes. Structural comparison of the NBS domains of all the homologs in Solanaceae revealed that one novel motif, 14, is specific to the Rx-like genes, and also indicated that several other novel motifs are characteristic of the R1-like genes. Our results suggest that Rx-like genes are ancient but conserved. Furthermore, the novel conserved motifs can provide a basis for biochemical structural. function analysis and be used for degenerate primer design for the isolation of Rx-like sequences in other plant species. Comparative mapping study revealed that the position of CapRGC is syntenic to the locations of Rx and its homolog genes in the potato and tomato, but cosegregation analysis showed that CapRGC may not be the R gene against PVX in pepper. Our results confirm previous observations that the specificity of R genes is not conserved, while the structure and function of R genes are conserved. It appears that CapRGC may function as a resistance gene to another pathogen, such as the nematode to which the structure of CapRGC is most similar.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.415-422
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• 2011

Previously, we reported that besides retinal ganglion cell (RGC) spike, there is ~10 Hz oscillatory rhythmic activity in local field potential (LFP) in retinal degeneration model, rd1 mice. The more recently identified rd10 mice have a later onset and slower rate of photoreceptor degeneration than the rd1 mice, providing more therapeutic potential. In this study, before adapting rd10 mice as a new animal model for our electrical stimulation study, we investigated electrical characteristics of rd10 mice. From the raw waveform of recording using $8{\times}8$ microelectrode array (MEA) from in vitro-whole mount retina, RGC spikes and LFP were isolated by using different filter setting. Fourier transform was performed for detection of frequency of bursting RGC spikes and oscillatory field potential (OFP). In rd1 mice, ~10 Hz rhythmic burst of spontaneous RGC spikes is always phase-locked with the OFP and this phase-locking property is preserved regardless of postnatal ages. However, in rd10 mice, there is a strong phase-locking tendency between the spectral peak of bursting RGC spikes (~5 Hz) and the first peak of OFP (~5 Hz) across different age groups. But this phase-locking property is not robust as in rd1 retina, but maintains for a few seconds. Since rd1 and rd10 retina show phase-locking property at different frequency (~10 Hz vs. ~5 Hz), we expect different response patterns to electrical stimulus between rd1 and rd10 retina. Therefore, to extract optimal stimulation parameters in rd10 retina, first we might define selection criteria for responding rd10 ganglion cells to electrical stimulus.

• Journal of Gastric Cancer
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• v.22 no.3
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• pp.210-219
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• 2022

Purpose: Completion total gastrectomy (CTG) for remnant gastric cancer (RGC) is a technically demanding procedure and associated with increased morbidity. The present study aimed to evaluate postoperative complications and their risk factors following surgery for RGC after initial partial gastrectomy due to gastric cancer excluding peptic ulcer. Materials and Methods: We retrospectively reviewed the data of 107 patients who had previously undergone an initial gastric cancer surgery and subsequently underwent CTG for RGC between March 2002 and December 2020. The postoperative complications were graded using the Clavien-Dindo classification. Logistic regression analyses were used to determine the risk factors for complications. Results: Postoperative complications occurred in 34.6% (37/107) of the patients. Intra-abdominal abscess was the most common complication. The significant risk factors for overall complications were multi-visceral resections, longer operation time, and high estimated blood loss in the univariate analysis. The independent risk factors were multi-visceral resection (odds ratio [OR], 2.832; 95% confidence interval [CI], 1.094-7.333; P=0.032) and longer operation time (OR, 1.005; 95% CI, 1.001-1.011; P=0.036) in the multivariate analysis. Previous reconstruction type, minimally invasive approach, and current stage were not associated with the overall complications. Conclusions: Multi-visceral resection and long operation time were significant risk factors for the occurrence of complications following CTG rather than the RGC stage or surgical approach. When multi-visceral resection is required, a more meticulous surgical procedure is warranted to improve the postoperative complications during CTG for RGC after an initial gastric cancer surgery.

• Journal of Gastric Cancer
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• v.22 no.4
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• pp.369-380
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• 2022

Purpose: Tumor recurrence is the principal cause of poor outcomes in remnant gastric cancer (RGC) after resection. We sought to elucidate the recurrent patterns according to tumor locations in RGC. Materials and Methods: Data were collected from the Shanghai Cancer Center between January 2006 and December 2020. A total of 129 patients with RGC were included in this study, of whom 62 had carcinomas at the anastomotic site (group A) and 67 at the non-anastomotic site (group N). The clinicopathological characteristics, surgical results, recurrent diseases, and survival were investigated according to tumor location. Results: The time interval from the previous gastrectomy to the current diagnosis was 32.0±13.0 and 21.0±13.4 years in groups A and N, respectively. The previous disease was benign in 51/62 cases (82.3%) in group A and 37/67 cases (55.2%) in group N (P=0.002). Thirty-three patients had documented sites of tumor recurrence through imaging or pathological examinations. The median time to recurrence was 11.0 months (range, 1.0-35.1 months). Peritoneal recurrence occurred in 11.3% (7/62) of the patients in group A versus 1.5% (1/67) of the patients in group N (P=0.006). Hepatic recurrence occurred in 3.2% (2/62) of the patients in group A versus 13.4% (9/67) of the patients in group N (P=0.038). Patients in group A had significantly better overall survival than those in group N (P=0.046). Conclusions: The tumor location of RGC is an essential factor for predicting recurrence patterns and overall survival. When selecting an optimal postoperative follow-up program for RGC, physicians should consider recurrent features according to the tumor location.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.364-366
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• 2009

광 바이오 센서 시스템에서 Trans-Impedance amplifier (TIA)는 광검출기로부터 입력단으로 들어오는 미세한 전기 신호를 원하는 신호레벨까지 증폭하는 역할을 한다. TIA는 광 바이오 센서 시스템의 감도 (sensitivity)를 결정하는 매우 중요한 회로로 저잡음, 저전력, 낮은 입력 임피던스 등의 특성이 요구되어진다. 본 논문에서는 광 바이오 센서 시스템에서 요구되어 지는 저전력, 저잡음 성능을 구현하기 위하여 regulated cascode (RGC) TIA를 설계하였다. 본 연구에서는 기존 common gate (CG) 기법의 TIA에서 전류원 역할을 하는 current source를 저항으로 대체하고, local feedback stage를 이용하는 RGC TIA를 저잡음, 저전력 특성 및 회로 면적 감소의 장점을 갖도록 설계하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.3
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• pp.15-20
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• 2012

This paper presents a 5-Gb/s optical receiver circuit realized in a $0.13-{\mu}m$ CMOS technologies for the applications of high-speed digital interface. Exploiting modified RGC input stage at the front-end transimpedance amplifier, interleaving active feedback and source degeneration techniques at the limiting amplifier, the proposed optical receiver chip demonstrates the measured results of $72-dB{\Omega}$ transimpedance gain, 4.7-GHz bandwidth, and $400-mV_{pp}$differential output voltage swings up to the data rate of 5-Gb/s. Also, the chip dissipates 66mW in total from a single 1.2-V supply, and occupies the area of $1.6{\times}0.8mm^2$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.8 s.338
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• pp.53-60
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• 2005

Recently, sub-micron CMOS technologies have taken the place of III-V materials in a number of areas in integrated circuit designs, in particular even for the applications of gjgabit optical communication applications due to its low cost, high integration level, low power dissipation, and short turn-around time characteristics. In this paper, a four-channel transimpedance amplifier (TIA) array is realized in a standard 0.35mm CMOS technology Each channel includes an optical PIN photodiode and a TIA incorporating the fully differential regulated cascode (RGC) input configuration to achieve effectively enhanced transconductance(gm) and also exploiting the inductive peaking technique to extend the bandwidth. Post-layout simulations show that each TIA demonstrates the mid-band transimpedance gain of 59.3dBW, the -3dB bandwidth of 2.45GHz for 0.5pF photodiode capacitance, and the average noise current spectral density of 18.4pA/sqrt(Hz). The TIA array dissipates 92mw p in total from a single 3.3V supply The four-channel RGC TIA array is suitable for low-power, high-speed optical interconnect applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.241-244
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• 2012

In this paper, three types of optical receivers are designed using a $0.35-{\mu}m$ standard CMOS technology for plastic optical fiber (POF) applications. Basic common-source transimpedance amplifier (CS-TIA), common-gate TIA (CG-TIA), and regulated-cascode TIA (RGC-TIA) are optimally designed, and their transimpedance gain (TZ gain), 3-dB bandwidth, and noise characteristics are compared and analyzed. As a result of simulations, the RGC-TIA indicates better TZ gain and 3-dB bandwidth than other topologies, and CS-TIA has the best noise performance. Each optical receiver occupies area of $0.35mm^2$.

• Molecules and Cells
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• v.37 no.8
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• pp.613-619
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• 2014

The optic nerve often suffers regenerative failure after injury, leading to serious visual impairment such as glaucoma. The main inhibitory factors, including Nogo-A, oligodendrocyte myelin glycoprotein, and myelin-associated glycoprotein, exert their inhibitory effects on axonal growth through the same receptor, the Nogo-66 receptor (NgR). Oncomodulin (OM), a calcium-binding protein with a molecular weight of an ~12 kDa, which is secreted from activated macrophages, has been demonstrated to have high and specific affinity for retinal ganglion cells (RGC) and promote greater axonal regeneration than other known polypeptide growth factors. Protamine has been reported to effectively deliver small interference RNA (siRNA) into cells. Accordingly, a fusion protein of OM and truncated protamine (tp) may be used as a vehicle for the delivery of NgR siRNA into RGC for gene therapy. To test this hypothesis, we constructed OM and tp fusion protein (OM/tp) expression vectors. Using the indirect immunofluorescence labeling method, OM/tp fusion proteins were found to have a high affinity for RGC. The gel shift assay showed that the OM/tp fusion proteins retained the capacity to bind to DNA. Using OM/tp fusion proteins as a delivery tool, the siRNA of NgR was effectively transfected into cells and significantly down-regulated NgR expression levels. More importantly, OM/tp-NgR siRNA dramatically promoted axonal growth of RGC compared with the application of OM/tp recombinant protein or NgR siRNA alone in vitro. In addition, OM/tp-NgR siRNA highly elevated intracellular cyclic adenosine monophosphate (cAMP) levels and inhibited activation of the Ras homolog gene family, member A (RhoA). Taken together, our data demonstrated that the recombinant OM/tp fusion proteins retained the functions of both OM and tp, and that OM/tp-NgR siRNA might potentially be used for the treatment of optic nerve injury.