• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.487-497
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• 2018

Water quality improvement processes for stagnant area consist mainly of technologies applying vegetation and artificial water circulation, and these existing technologies have some limits to handle pollution loads effectively. To improve the purification efficiency, eco-friendly technologies should be developed that can reinforce self-purification functions. In this study, a multi-functional floating island combined with physical chemical biological functions ((1) flotation and oxidization using microbubbles, (2) vegetation purification and (3) bio-filtration with improved adsorption capacity) has been developed and basic experiments were performed to determine the optimal combination conditions for each unit process. It has been shown that it is desirable to operate the microbubble unit process under conditions greater than $3.5kgf/cm^2$. In vegetation purification unit process, Yellow Iris (Iris pseudacorus) was suggested to be suitable considering water quality, landscape improvement and maintenance. When granular red-mud was applied to the bio-filtration unit process, it was found that T-P removal efficiency was good and its value was also stable for various linear velocity conditions. The appropriate thickness of filter media was suggested between 30 and 45 cm. In this study, the optimal design and operating parameters of the multi-functional floating island have been presented based on the results of the basic experiments of each unit process.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.486-490
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• 2015

Two-demensional echocardiography is routinely used for evaluation of cardiac function. Visualization of the endocardial border is essential for the assessment of global and regional left ventricular with cardiac disease. SonoVue$^{TM}$ is a microbubble contrast agent that consists of sulfur hexafluoride-filled microbubbles in a phospholipid shell. There were many studies about contrast echocardiographic examination using SonoVue$^{TM}$ contrast agent, and various doses of SonoVue$^{TM}$ were used. To our knowledge, in published veterinary medicine, there was not reported for diagnostic efficient dose of SonoVue$^{TM}$ to evaluate contrast enhanced left ventricular endocardial border delineation (LVEBD). The purpose of this study is to compare the visualization time of LVEBD and find efficient dose of SonoVue$^{TM}$ for using various doses in dogs. Ten healthy Beagles were recruited to the study. Three different doses (0.03 ml/kg, 0.05 ml/kg and 0.1 ml/kg) of SonoVue$^{TM}$ were injected. Endocardial segments were assigned based on previously established methodology, where by the four-chamber views of the LV were divided into 6 segments. In this study, Contrast enhancement of the LVEBD after each injection was evaluated visually at the time point of overall contrast enhancement (Segmental scoring 5+) in the LV by three investigators in a blind manner. Statistical analysis was performed with SPSS version 14.0. All data were analyzed using one-way ANOVA, the multiple comparison Scheffe test. When data for the three offsite readers were combined, mean durations of useful contrast were $3.54({\pm}2.14)$, $6.15({\pm}2.61)$, and $24.39({\pm}11.10)$ seconds for the 0.03 ml/kg, 0.05 ml/kg, and 0.1 ml/kg SonoVue$^{TM}$ doses, respectively. After injection of contrast agent, there were no significant change in side effects such as urticaria, angioedema, hypersensitivity reactions, and digestive system disorders. This study suggests that efficient dose of SonoVue$^{TM}$ contrast agent for improvement of the left ventricle visualization is 0.1 ml/kg. The duration of useful enhancement of LVEBD and the reproducibility were also the highest at the 0.1 ml/kg dosage.

• Ultrasonography
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• v.32 no.1
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• pp.59-65
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• 2013

Purpose: The purpose of this study is to establish the methodology regarding synthesis of ultrasound contrast agent imaging, and to evaluate the characteristics of the synthesized ultrasound contrast agents, including size or degradation interval and image quality. Materials and Methods: The ultrasound contrast agent, composed of liposome and SF6, was synthesized from the mixture solution of $21{\mu}mol$ DPPC (1, 2-Dihexadecanoyl-sn-glycero-3-phosphocholine, $C_{40}H_{80}NO_8P$), $9{\mu}mol$ cholesterol, $1.9{\mu}mol$ of DCP (Dihexadecylphosphate, $[CH_3(CH_2)_{15}O]_2P(O)OH$), and chloroform. After evaporation in a warm water bath and drying during a period of 12-24 hours, the contrast agent was synthesized by the sonication process by addition of buffer and SF6 gas. The size of the contrast agent was controlled by use of either extruder or sonication methods. After synthesis of contrast agents, analysis of the size distribution of the bubbles was performed using dynamic light scattering measurement methods. The degradation curve was also evaluated by changes in the number of contrast agents via light microscopy immediate, 12 hours, 24 hours, 36 hours, 48 hours, 60 hours, 72 hours, and 84 hours after synthesis. For evaluation of the role as an US contrast agent, the echogenicity of the synthesized microbubble was compared with commercially available microbubbles (SonoVue, Bracco, Milan, Italy) using a clinical ultrasound machine and phantom. Results: The contrast agents were synthesized successfully using an evaporation-drying-sonication method. The majority of bubbles showed a mean size of 154.2 nanometers, and they showed marked degradation 24 hours after synthesis. ANOVA test revealed a significant difference among SonoVue, synthesized contrast agent, and saline (p < 0.001). Although no significant difference was observed between SonoVue and the synthesized contrast agent, difference in echogenicity was observed between synthesized contrast agent and saline (p < 0.01). Conclusion: We could synthesize ultrasound contrast agents using an evaporation-drying-sonication method. On the basis of these results, many prospective types of research, such as anticancer drug delivery, gene delivery, including siRNA or microRNA, targeted molecular imaging, and targeted therapy can be performed.

• Ultrasonography
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• v.32 no.2
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• pp.132-142
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• 2013

Purpose: The purpose of this study is to investigate the correlations of various kinetic parameters derived from the time intensity curve in a xenograft mouse model injected with a prostate cancer model (PC-3 and LNCaP) using an ultrasound contrast agent with histopathologic parameters. Materials and Methods: Twenty nude mice were injected with human prostate cancer cells (15 PC-3 and five LNCaP) on their hind limbs. A bolus of $500{\mu}L$ ($1{\times}10^8$ microbubbles) of second-generation US contrast agent (SonoVue) was injected into the retroorbital vein. The region of interest was drawn over the entire tumor. The time intensity curve was acquired and then fitted to a gamma variate function. The maximal intensity (A), time to peak (Tp), maximal wash-in rate (washin), washout rate (washout), area under the curve up to 50 sec ($AUC_{50}$), area under the ascending slope ($AUC_{in}$), and area under the descending slope ($AUC_{out}$) were derived from the parameters of the gamma variate fit. Immunohistochemical staining for VEGF and CD31 was performed. Tumor volume, the area percentage of VEGF stained in a field, and the count of CD31 (microvessel density, MVD) positive vessels showed correlation with the parameters from the time intensity curve. Results: No significant differences were observed between the kinetic and histopathological parameters from each group. MVD showed positive correlation with A (r=0.625, p=0.003), washin (r=0.462, p=0.040), $AUC_{50}$ (r=0.604, p=0.005), and $AUC_{out}$ (r=0.587, p=0.007). Positive correlations were also observed between tumor volume and $AUC_{50}$ (r=0.481, p=0.032), washin (r=0.662, p=0.001), and $AUC_{out}$ (r=0.547, p=0.012). Washout showed negative correlations with MVD (r=-0.454, p=0.044) and tumor volume (r=-0.464, p=0.039). The area percentage of VEGF did not show any correlation with calculated data from the curve. Conclusion: MVD showed correlations with several of the kinetic parameters. CEUS has the potential for prediction of tumor vascularity in a prostate cancer animal model.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.889-902
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• 2021

Purpose To assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) for additional MR-detected enhancing lesions and to determine whether or not kinetic pattern results comparable to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of the breast can be obtained using the quantitative analysis of CEUS. Materials and Methods In this single-center prospective study, a total of 71 additional MR-detected breast lesions were included. CEUS examination was performed, and lesions were categorized according to the Breast Imaging-Reporting and Data System (BI-RADS). The sensitivity, specificity, and diagnostic accuracy of CEUS were calculated by comparing the BI-RADS category to the final pathology results. The degree of agreement between CEUS and DCE-MRI kinetic patterns was evaluated using weighted kappa. Results On CEUS, 46 lesions were assigned as BI-RADS category 4B, 4C, or 5, while 25 lesions category 3 or 4A. The diagnostic performance of CEUS for enhancing lesions on DCE-MRI was excellent, with 84.9% sensitivity, 94.4% specificity, and 97.8% positive predictive value. A total of 57/71 (80%) lesions had correlating kinetic patterns and showed good agreement (weighted kappa = 0.66) between CEUS and DCE-MRI. Benign lesions showed excellent agreement (weighted kappa = 0.84), and invasive ductal carcinoma (IDC) showed good agreement (weighted kappa = 0.69). Conclusion The diagnostic performance of CEUS for additional MR-detected breast lesions was excellent. Accurate kinetic pattern assessment, fairly comparable to DCE-MRI, can be obtained for benign and IDC lesions using CEUS.