• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권9호
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• pp.1613-1631
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• 2011

Several metrics have been reported in the literature to assess stereo image quality, mostly based on visual attention or human visual sensitivity based distortion prediction with the help of disparity information, which do not consider the combined aspects of human visual processing. In this paper, visual attention and depth assisted stereo image quality assessment model (VAD-SIQAM) is devised that consists of three main components, i.e., stereo attention predictor (SAP), depth variation (DV), and stereo distortion predictor (SDP). Visual attention is modeled based on entropy and inverse contrast to detect regions or objects of interest/attention. Depth variation is fused into the attention probability to account for the amount of changed depth in distorted stereo images. Finally, the stereo distortion predictor is designed by integrating distortion probability, which is based on low-level human visual system (HVS), responses into actual attention probabilities. The results show that regions of attention are detected among the visually significant distortions in the stereo image pair. Drawbacks of human visual sensitivity based picture quality metrics are alleviated by integrating visual attention and depth information. We also show that positive correlation with ground-truth attention and depth maps are increased by up to 0.949 and 0.936 in terms of the Pearson and the Spearman correlation coefficients, respectively.

• Biomolecules & Therapeutics
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• 제31권4호
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• pp.425-433
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• 2023

During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

• 한국환경과학회지
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• 제17권6호
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• pp.699-709
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• 2008

To understand the development mechanism of the aerosols in the surface boundary layer, the variation in the aerosol number concentration due to the divergence and convergence of the wind fields was investigated. The aerosol number concentration was measured in the size ranges of $0.3{\sim}10.0{\mu}m$ using a laser particle counter(LPC) from 0000 LST on 03 Feb. to 0600 LST on 07 Feb. 2004 at Mokpo in Korea during snowfall. The Velocity Azimuth Display(VAD) technique was used to retrieve the radar wind fields such as the horizontal wind field, divergence, and deformations including the vertical air velocity from a single Doppler radar. As a result, the distribution of the aerosol number concentration is apparently different for particles larger than $1{\mu}m$ during snowfall, and it has a tendency to increase at the beginning of the snowfall. The increase and decrease in the aerosol concentration due to the convergence and divergence of the wind fields corresponded to the particles with diameters greater than $1{\mu}m$. It is found that the fluctuations in the aerosol number concentration are well correlated with the development and dissipation of snowfall radar echoes due to the convergence and divergence of horizontal wind fields near the surface boundary layer in the inland during the snowfall.

• 대한한방내과학회지
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• 제33권4호
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• pp.587-598
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• 2012

Objectives : This study was performed to elucidate the pro-apoptotic effect of Artemisiae capillaris herba extracted with ethanol on biliary tract cancer cells. Materials and Methods : The biliary tract cancer cell line SNU-1196 was used in this study. Cells were treated with different concentrations of Artemisiae capillaris herba for 24, 48 and 72 hours. After the treatment, cell viability, apoptosis, caspase activities and the mRNA expressions of the Bcl-2, Bax, P53, and P21 were measured by using MTT assay, cell cycle analysis, apoptosis assay, and RT-PCR. The cell cycle analysis was done by flow cytometry and apoptosis assay by cell death detection ELISA kit. Results : Artemisiae capillaris herba inhibited proliferation of SNU-1196 in long-time culture group with dose-dependent manner. All cells treated with Artemisiae capillaris herba showed increased apoptosis with dose- and time-dependent manner. Exposure of SNU-1196 to Artemisiae capillaris herba induced caspase-3 activation. However, apeoptosis was blocked when SNU-1196 was treated together with the pan-caspase inhibitor Z-VAD-FMK and the caspase-3 inhibitor Z-DEVE-FMK. After the treatment of Artemisiae capillaris herba, the mRNA expressions of caspase -3, -8, -9, p53, and p21 was increased in all cells. Artemisiae capillaris herba resulted in a significant decrease in Bcl-2 and an increase in Bax mRNA levels. Conclusions : These results suggest that Artemisiae capillaris herba would be beneficial in the treatment of biliary tract cancer.

• 한국전산유체공학회지
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• 제20권3호
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• pp.79-86
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• 2015

A blood pump is an important part of a cardiac assist device. Since the shear rate in blood is known to be a primary factor on hemolysis generation, it has been very important to evaluate hemolysis inside blood pumps for understanding performance and reliability of cardiac assist devices. In this study, hemolysis generation inside blood pumps is analyzed using CFD with power-law based models for the blood damage index(BDI), in order to overcome difficulties in measuring hemolysis by experiment. The BDI values in blood pumps can be evaluated using Lagrangian or Eulerian approaches. In this study, several Lagrangian and Eulerian approaches are compared to estimate the efficiency of the numerical methods in a practice sense. It is found that the Eulerian approaches are advantageous in terms of the efficiency and robustness. Two different Eulerian approaches are used to evaluate the BDI values of a few commercial blood pumps. For the conditions of extracorporeal membrane oxygenator(ECMO) and ventricular assist device(VAD), local generation of hemolysis is analyzed using divided regions of blood pumps, in order to investigate the effects of the pump geometry.

• 대한약침학회지
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• 제22권4호
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• pp.269-278
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• 2019

Objectives: Naesohwangryeon-tang (NHT) is a type of traditional herbal formula, however, little is known about its antitumor activity. In this study, the antitumor properties of NHT was evaluated in human lung adenocarcinoma cells. Methods: To check the inhibitory effect of NHT, MTT assay was performed. Cell cycle analysis and detection of ROS production were conducted by flow cytometry. To evaluate the signaling pathway, Western blotting was conducted. Results: Our results showed that the decrease of cell proliferation by NHT stimulation occurred more significantly in A549 cells than in NCI-H460 cells. In addition, NHT-induced apoptosis was associated with the activation of caspases and production of reactive oxygen species (ROS). NHT-induced apoptosis was attenuated after pretreatments with z-VAD-fmk or N-acetylcysteine, suggesting that NHT-induced apoptosis was caspaseand ROS-dependent. Interestingly, NHT treatment led to the development of autophagic vesicular organelles and upregulation of several autophagy-related genes. The pretreatment of bafilomycin A1 decreased apoptosis slightly but increased cell viability in the presence of NHT. Conclusion: These findings indicated that NHT induces both apoptosis and cell-protective autophagy in human lung cancer cells. This data suggests that NHT might be a novel herbal drug for lung cancer.

• Parasites, Hosts and Diseases
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• 제52권5호
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• pp.459-469
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• 2014

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-${\kappa}B$ (p65) in Caco-2 cells. However, $I{\kappa}B$, an inhibitor of NF-${\kappa}B$, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-${\kappa}B$ was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-${\kappa}B$ and STATs in colonic epithelial cells, which ultimately accelerates cell death.

• Journal of Chest Surgery
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• 제24권11호
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• pp.1045-1057
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• 1991

Over the past four decades after World War II a great deal of data and clinical experiences have been accumulated relating to the diagnosis and surgical treatment of cardiovascular diseases in Korea. Clinical data after the first open heart surgery by Professor Yung Kyoon Lee on August 7, 1959 up to 1984 revealed the total number of cardiovascular surgery in Korea as 13,100 cases performed in 22 institutes with overall hospital mortality of 7.7%[Cardiovascular Surgery in Korea 1985], Publishing committee of the Korean Thoracic and Cardiovascular Surgical Society collected the data of cardiovascular surgical cases in Korea again in between 1985 and 1990 from 38 institutes out of total 42 institutes of open heart centers in Korea. The results are: 1. The survey reply ratio was 90.5%[38 out of 42 institutes]. 2. Of the total 30,061 cases of cardiovascular surgery reported from 38 institutes 1,402 cases were failed as hospital mortality of 4.7%[4.5% of the 21,761 operations for congenital, and 5.2% of the 8,300 operations for acquired heart diseases]. Out of the total congenital cases, 17,303 cases were acyanotic group with a operative mortality as 2.0%, and 4,458 cases were cyanotic group with a hospital mortality as 14.le The incidence of corrective operations for complex congenital cardiac anomalies were increasing recently with decreasing age group. 3. During the year in 1990, 38 institutes performed 5,427 cardiovascular surgery with a hospital mortality of 3.4%. 4. Of the total cumulative 6,458 cases for cardiac valve surgery more than 90% cases were put to prosthetic valve replacement with hospital mortality as 4.8%. And the incidence of re-Do valve surgery was increasing recently as 13.1% in 1990. 5. Coronary artery bypass graft was increasing recently with 7.9% of hospital mortality in total 440 cases. Intracardiac operation for intractable arrhythmia was started since 1987 as 49 cases in total. Experiences on VAD and ECMO were also reported sporadically in recent year. 6. Home made oxygenator[OXYREX] is now in clinical use, and under animal experiment for clinical trial in near future.

• 전기학회논문지
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• 제58권4호
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• pp.857-866
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• 2009

In this paper, a noise cancellation-method using microphone array for digital hearing aids is proposed. The microphone array is located around the ear of a dummy. Speech sound is generated from the forward speaker positioned in the front of the dummy and noise sound is generated from the backward speaker. The speech and noise are mixed in the air space and entered into the microphones. VAD(voice activity detector) and ANC(adaptive noise cancellation) methods were used to eliminate noise in the sound of the microphones. 10 two-syllable words and 4 sentences were used for speech signals. Babble and car interior noise were used for noise signals. The performance of the proposed algorithm was evaluated by SNR(signal-to-noise ratio) and PESQ-MOS(perceptual evaluation of speech quality-mean opinion score). In babble noise condition, SNR was improved as much as $7.963{\pm}1.3620dB\;and\;3.968{\pm}0.6659dB$ for words and sentences respectively. In the case of car interior noise, SNR was improved as $10.512{\pm}2.0665dB\;and\;6.000{\pm}1.7642dB$ for words and sentences respectively. PESQ-MOS of the babble noise was improved as much as $0.1722{\pm}0.0861$ score for words and $0.083{\pm}0.0417$ score for sentences. And PESQ-MOS of the car interior noise was improved as $0.2661{\pm}0.0335$ score and $0.040{\pm}0.0201$ score for words and sentences respectively. It is verified that the proposed algorithm has a good performance in noise cancellation of microphone array for digital hearing aids.

• 전자공학회논문지
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• 제51권5호
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• pp.188-194
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• 2014

계산적 청각 장면 분석 시스템의 특징 추출은 시간 연속성과 주파수 채널간에 유사성을 이용하여 청각 요소의 상관지도를 구성한다. 세그먼테이션은 상호상관계수 함수를 이용하여 2진 마스크를 구성하고, 마스크 성분 1(음성)은 동일한 주기성과 동기를 가진다. 그러나 채널간에 비슷한 주기성을 갖지만 지연이 있는 경우에 음성으로 잘못 결정되는 문제가 있다. 본 논문에서는 세그먼테이션에서 가중치 상호상관계수를 이용해 채널간에 유사성의 변별력을 높이는 방법을 제안한다. 계산적 청각 장면 분석 시스템의 음성분리 성능을 평가하기 위하여 배경 잡음(사이렌, 기계, 백색, 자동차, 군중) 환경에서 신호 대 잡음비(5dB, 0dB)의 변화에 따라 실험을 수행하였다. 본 논문에서는 기존의 방법과 제안한 방법과 비교한 결과, 제안한 방법이 기존의 방법에 비하여 각각 신호 대 잡음비 5dB에서 2.75dB 그리고 0dB에서 4.84dB 향상되었다.