• Journal of Digestive Cancer Research
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• v.6 no.2
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• pp.59-63
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• 2018

Over the past decade, circulating tumor cell have received tremendous attention as new biomarkers and basic research subjects.In recent years, research on circulating tumor DNA, exosomes and microRNAs has also been actively conducted.These circulating tumor markers have the potential to become the basis of precision medicine, such as determining the genome / immune profile, monitoring response and tolerance, and selecting therapeutic agents beyond the early diagnosis and prognosis prediction.In this article, we introduce the diagnostic methods, efficacy, meaning, and applicability of various circulating tumor markers.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.371-372
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• 2008

Many kinds of electrodes have been developed in various forms and shapes for measurement of bio potential signal. Textile electrode has benefit of collect long tenn data monitoring because of it is non-consciousness, convenient and do not occur skin irritation. However, It is very difficult to acquire available data due to high impedance of electrode and unstable skin-electrode contact which generate motion artifact. Also snap button which usually used as mediator between textile and measurement device cause change of electrical characteristics. In this paper, we inflated textile electrode to stabilize contact and add conductive silver paste between textile and snap button to improve conductance. To compare the performance of two methods, flat or inflated and add conductive paste or not, four types of electrodes are tested on each impedance and SNR by ECG measurement. In result, the first type electrode which flat and non-conductive paste showed the worst performance and the last type electrode which is inflated shape and contain conductive paste show the best performance.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.410-416
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• 2007

This paper presents quantitative analysis of a training system based on an unstable platform and a visual interactive system for improving sense of equilibrium. The training system consists of an unstable platform, a force plate, a safety harness, a monitoring device, and a personal-computer. To confirm the effects of the training system, fifteen young volunteers and five elderly volunteers went through a series of balance training using the system. During the training, we measured relevant parameters such as the time a subject maintain his or her center of pressure on a target, the time a subject moves his or her center of pressure to the target, and the mean absolute deviation of the trace before and after training with this system and training programs to evaluate the effects of the training. The results showed that the training system can successfully assess the gradual improvement of the postural control capability of the subject in the system and showed a possibility of improving balance of the subject. Moreover, the significant improvement in the postural capability of the elderly subject suggests that elderly subjects can benefit more from the training using the system for the improvement of sense of equilibrium.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.299-306
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• 2013

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been widely used as a treatment for the movement disturbances caused by Parkinson's disease (PD). Despite successful application of DBS, its mechanism of therapeutic effect is not clearly understood. Because PD results from the degeneration of dopamine neurons that affect the basal ganglia (BG) network, investigation of neuronal responses of BG neurons during STN DBS can provide informative insights for the understanding of the mechanism of therapeutic effect. However, it is difficult to observe neuronal activity during DBS because of large stimulation artifacts. Here, we report the observation of neuronal activities of the globus pallidus (GP) in normal and PD model rats during electrical stimulation of the STN. A custom artifact removal technique was devised to enable monitoring of neural activity during stimulation. We investigated how GP neurons responded to STN stimulation at various stimulation frequencies (10, 50, 90 and 130 Hz). It was observed that activities of GP neurons were modulated by stimulation frequency of the STN and significantly inhibited by high frequency stimulation above 50 Hz. These findings suggest that GP neuronal activity is effectively modulated by STN stimulation and strongly dependent on the frequency of stimulation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.176-183
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• 2016

In this study, disease surveillance was performed to monitor the prevalence of viral haemorrhagic septicaemia virus (VHSV) and red seabream iridovirus (RSIV) in olive flounder, Paralichthys olivaceus in 2015. The fish samples were collected in March (60 farms), May (55 farms) and July (52 farms) from different farms in Jeju. Reverse transcription polymerase chain reaction (RT-PCR) (VHSV) or PCR (RSIV) results showed that VHSV detected in 2 farms, but RSIV has not been detected in any farms. The sequences of the nucleocapsid protein (N) and glycoprotein (G) gene of the 2 VHSV isolates were successfully sequenced. Phylogenetic analysis was included VHSV isolates reported here together with a representative VHSV isolates available in GenBank. Phylogenetic analysis indicated that most of Korea VHSV isolates were closely related to the Japan and China genotype IVa which is clearly distinct from the North American genotype IVb.

• Current Optics and Photonics
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• v.3 no.6
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• pp.555-565
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• 2019

Development of a biomarker for predicting tumor-treatment efficacy is a matter of great concern, to reduce time, medical expense, and effort in oncology therapy. In a preclinical study, we hypothesized that the blood-flow parameter based on laser speckle flowmetry (LSF) could be a potential indicator to estimate the efficacy of breast-cancer treatment. To verify this hypothesis, a 13762-MAT-B-III rat breast tumor was grown in a dorsal skinfold window chamber applied to a nude mouse, and the change in blood flow rate (BFR) - or the speckle flow index (SFI) is used together as the same meaning in this manuscript - was longitudinally monitored during tumor growth and metronomic cyclophosphamide treatment. Based on the daily LSF angiogram, several BFR parameters (baseline SFI, normalized SFI, and △rBFR) were compared to tumor size in the normal, treated, and untreated tumor groups. Despite the incomplete tumor treatment, we found that the daily changes in all BFR parameters tended to have partially positive correlation with tumor size. Moreover, we observed that the changes in baseline SFI and normalized SFI responded one day earlier than the tumor shrinkage during chemotherapy. However, daily variations in the hypercapnia-induced △rBFR lagged tumor shrinkage by one day. This study would contribute not only to evaluating tumor vascular response to treatment, but also to monitoring blood-flow-mediated diseases (in brain, skin, and retina) by using LSF in preclinical settings.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.73-79
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• 2002

The goals of this study are twofold: To investigate non-phobics'and Phobics'Physiological response in virtual environments. and to analyze the trend of phobics' Physiology during virtual reality treatment. As a measure of Physiology. heart rate, skin resistance. and skin temperature were acquired. The data of two group subjects were analyzed: twenty-two non-Phobic subjects (M=32.94 years). thirty-six subjects with fear of flying (M=40.12 yearn) who met the DSM-lV criteria for a fear of flying. As a result. skin resistance showed significant differences between non-Photics and phobics. T(56) =2.978, P〈0.01 And the physiological responses of 33 subjects among the Phobics. who succeed to fly without medicine after virtual reality treatment, showed a gradual trend toward the non-Phobics Physiological responses as therapy sessions went on. In this study. Physiological monitoring. skin resistance appeared to be useful both in understanding the Physiological state of Phobic individuals and in evaluating the results of treatment in virtual reality Psychotherapy.

• Current Optics and Photonics
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• v.1 no.4
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• pp.412-420
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• 2017

Multinucleated bone resorptive osteoclasts differentiate from bone marrow-derived monocyte/macrophage precursor cells. During osteoclast differentiation, mononuclear pre-osteoclasts change their morphology and biochemical characteristics. In this study, Raman spectroscopy with multivariate techniques such as Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were used to extract biochemical information related to various cellular events during osteoclastogenesis. This technique allowed for label-free and noninvasive monitoring of differentiating cells, and clearly discriminated four different time points during osteoclast differentiation. The Raman band intensity showed significant time-dependent changes that increased up to day 4. The results of Raman spectroscopy agreed with results from atomic force microscopy (AFM) and tartrate-resistant acid phosphatase (TRAP) staining, a conventional biological assay. Under AFM, normal spindle-like mononuclear pre-osteoclasts became round and smaller at day 2 after treatment with a receptor activator of nuclear $factor-{\kappa}B$ ligand and they formed multinucleated giant cells at day 4. Thus, Raman spectroscopy, in combination with PCA-LDA, may be useful for noninvasive label-free quality assessment of cell status during osteoclast differentiation, enabling more efficient optimization of the bioprocesses.

• Journal of the Korean Magnetic Resonance Society
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• v.13 no.2
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• pp.64-83
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• 2009

The purpose of this study was to evaluate the usefulness of in vivo 3T $^1H$ MRS with short TE for prescreening various brain diseases. Together with ten normal volunteers, 12 brain tumor patients(2 lymphomas, 5 malignant gliomas) and 5(benign meningiomas) and 10 brain ischemic disease patients(6 acute and 4 subacute infarctions) participated. Lymphomas showed increased intensities of Cho and Lac. Likewise, gliomas showed increased Cho and Lac, but with decreased NAA and ${\beta}\;{\gamma}$-Glx; in higher grade of gliomas, Lac, Cho, mI and Lip predominantly increased with decrease of NAA. Benign meningiomas showed increased Cho, Lac and ${\beta}\;{\gamma}$-Glx; with decreased of NAA. The alanine peak at 1.47 ppm is a neuronal marker for meningiomas. Infarctions showed increased Lac and Lip and decreased NAA, ${\alpha}$-Glx and ${\beta}\;{\gamma}$-Glx where Lac increased with decreased of ${\alpha}$-Glx in acute, and Cho, Lac and Lip increased with decrease of NAA in subacute. Elevated Lac and decreased NAA levels were more aggravated in subacute. Clinical application of the $^1H$ MRS with short TE at 3T is able to povide valuable spectral information for prescreening various brain diseases by monitoring the changes of disease-specific cerebral metabolite concentrations in vivo, and consequently, it can be applicable to assessment of differential diagnosis and malignancy as well.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.71-75
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• 2019

Sleep apnea is a disease that causes various complications, and the polysomnography is expensive and difficult to measure. The purpose of this study is to develop an unrestricted wearable monitoring system so that patients can be examined in a familiar environment. We used a method to detect sleep apnea events and to determine sleep satisfaction by non-constrained method using SpO2 measurement sensor and 3-axis acceleration sensor. Heart rate and SpO2 were measured at the finger using max30100. After acquiring the SpO2 data of the user in real time, the apnea measurement algorithm was used to transmit the number of apnea events of the user to the mobile phone using Bluetooth (HC-06) on the wrist. Using the three-axis acceleration sensor (mpu6050) attached to the upper body, the number of times of tossing and turning during sleep was measured. Based on this data, this algorithm evaluates the patient's tossing and turning during sleep and transmits the data to the mobile phone via Bluetooth. The power source used 9 volts battery to operate Arduino UNO and sensors for portability and stability, and the data received from each sensor can be used to check the various degree between sleep apnea and sleep tossing and turning on the mobile phone. Through thisstudy, we have developed a wearable sleep apnea measurement system that can be easily used at home for the problem of low sleep efficiency of sleep apnea patients.