• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.382-390
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• 2020

Periplanetasin-4 is an antimicrobial peptide with 13 amino acids identified in cockroaches. It has been reported to induce fungal cell death by apoptosis and membrane-targeted action. Analogs were designed by substituting arginine residues to modify the electrostatic and hydrophobic interactions accordingly and explore the effect of periplanetasin-4 through the increase of net charge and the decrease of hydrophobicity. The analogs showed lower activity than periplanetasin-4 against gram-positive and gram-negative bacteria. Similar to periplanetasin-4, the analogs exhibited slight hemolytic activity against human erythrocytes. Membrane studies, including determination of changes in membrane potential and permeability, and fluidity assays, revealed that the analogs disrupt less membrane integrity compared to periplanetasin-4. Likewise, when the analogs were treated to the artificial membrane model, the passage of molecules bigger than FD4 was difficult. In conclusion, arginine substitution could not maintain the membrane disruption ability of periplanetasin-4. The results indicated that the attenuation of hydrophobic interactions with the plasma membrane caused a reduction in the accumulation of the analogs on the membrane before the formation of electrostatic interactions. Our findings will assist in the further development of antimicrobial peptides for clinical use.

• Applied Microscopy
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• v.18 no.2
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• pp.21-33
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• 1988

The purpose of this study was to investigate the effect of chlorambucil on the mouse Leydig cell by electron microscopy. Chlorambucil suspended in the 0.5N sodium bicarbonate(pH 8.0) was injected I.P.(intraperitoneal) at a dosage of level 20mg/kg for 1 weeks, 3 weeks and 5 weeks, respectively. The results obtained from this experiment are as follows: 1. One week after the administration of chlorambucil, there was an increase in heterochromatin, swelling and cristae disruption in some mitochondria, mild vacuolation between cells and the occurrence of membrane bound inclusions in some nuclei. 2. After 3 weeks, smooth endoplasmic reticulum dilations, cytoplasmic vacuolation, mitochondrial swelling, inner mitochondrial cristae disruption, membranous whorls, and intranuclear inclusions were observed in the treated cells. 3. After 5 weeks of treatment, most mitochondria were swollen and their membranes were severely disrupted. Further, smooth endoplasmic reticulum dilations and vacuolation of the cytoplasm were apparent in the treated Leydig cells. In addition numerous membranous whorls and intranuclear inclusion bodies were present. The nuclei displayed invaginatons of the nuclear membrane and large clumps of heterochromatin. From these results it is concluded the longer the duration of chlorambucil administration, the greater the degeneration of the nucleus and cytoplasmic organelles.

• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.54-61
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• 1999

The industrial techniques of ultrasound have been used in the various fields, such as cleaning, medical surgery, emulsification, cell disruption etc. Especially the application of cell disruption was interested in the field of disinfection process in water by ultrasonic irradiation. It has been recognized that the ultrasounds are irradiated in aqueous solution, cavitation bubbles are generated and shock waves of high temperature and pressure are emitted as the bubbles are developed and finally broken, which function as a energy source to promote reaction efficiencies of various kinds of chemical reactions such as disinfection reaction in water. Therefore, this study was performed to apply the ultrasound for the disinfection method of infected drinking raw water and to discuss the limiting factors such as pH, sample volume and reaction temperature influenced on the removal efficiency of E. coli from experimental analysis of the results obtained in bench-scale plant. For the experiments to measure the influence of reaction parameters in the ultrasonic disinfection process, escalated reactivity of aqueous solutions was excellent when pH in aqueous solution was low, and sample volume was small. On the contrary, the reactivity of disinfection became elevated when reaction temperature was high. It was found that the rate constant of disinfection reaction was applied by Chick's law, reaction kinetics of Chick's law was irreversible and pseudo-first order at all the tested conditions.As a conclusion it appeared that the technology using ultrasonic irradiation can be applied to the treatment of disinfection in infected water which are difficult to be treated by conventional methods.

• Journal of Chest Surgery
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• v.20 no.1
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• pp.55-69
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• 1987

The result of valve failure with the lonescu-Shiley pericardial xenograft was presented with the review of current knowledge. This study reviewed 557 patients, who underwent total of 683 lonescu-Shiley pericardial valve replacement from 1979 to 1985 at Seoul National University Hospital. There were 357 patients who had mitral valve replacement, 73 with aortic valve and 127 with double valve replacement. There were 35 operative deaths. The survivors were followed at OPD. There were 32 patients who had prosthetic valve failure, whose ages ranged from 11 to 58 years [mean 27.8] and their postop interval was 56 ~ 22 months [range; 6-87] The causes of valve failure are prosthetic valve endocarditis in 14, primary disruption or calcification in 13, paravalvular leakage in 4, and others in 2 patients. Redo valve replacement was done in 12 patients after a mean interval of 50 * 20 months. [range; 6-79 months] Actuarial analysis of late results indicates actuarial freedom from endocarditis at 6 year is 87.9 ~ 6.8%, and actuarial freedom from primary disruption or calcification or paravalvular leakage at 5 year is 84.4 * 2.3%. In this series, however, valve failure due to thrombosis is not included.

• Journal of Environmental Health Sciences
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• v.42 no.3
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• pp.169-188
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• 2016

Objectives: Although information on the toxicity of phthalate diesters is readily available, little is known about phthalate alternatives. The present article provides a summary of available information on the toxicity of phthalate diesters and their alternatives, with a special focus on estrogenicity and androgenicity. Methods: We collected a battery of in vitro and in vivo assay data from the literature to assess the estrogenicity/anti-estrogenicity and androgenicity/anti-androgenicity of 15 phthalate diesters and 21 phthalate alternatives. Results: A number of in vitro studies show that certain phthalate diesters can bind to estrogen receptors and have a weak estrogenic potential. However, this potential was not seen in in vivo studies. Phthalate diesters produced anti-androgenic effects in animals by reducing testosterone production. Among them, di-(2-ethyl-hexyl) phthalate (DEHP) was the most potent. While almost all phthalate alternatives have a lower toxic potential than does DEHP, evidence of reproductive toxicity and estrogenic potential were found in several substances. Conclusion: Significant data gaps exist for phthalate alternatives regarding reproductive endocrine disruption, requiring further investigation.

• Journal of Chest Surgery
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• v.28 no.8
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• pp.772-777
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• 1995

Bronchoplastic procedure has been considered as an appropriate surgery for traumatic bronchial disruption and occasionaly for primary bronchial tumors or tuberculosis because it can bring preservation of pulmonary tissue for patients without compromising the chance for cure. Nowadays bronchoplastic procedure is also applicable for the selected cases of bronchogenic carcinomas with favorable long term survival, when compared to standard pneumonectomy.Eighteen bronchoplastic procedures were performed with or without pulmonary resection at Department of Thoracic and Cardiovascular Surgery, Catholic University Medical College, between 1990 and 1994. The patients were 11 men and 7 wemen with average age of 57 years [range, 19 to 71 years . Tumor comprised 56% of the lesions, including 6 squamous cell carcinoma [33% , 2 bronchial adenoma [11% , 1 leiomyoma and 1 metastatic osteogenic sarcoma. Cicatrical stenosis secondary to endobronchial tuberculosis and traumatic disruption occurred in 6 [33% and 1 patient respectively.Applied bronchoplastic procedures were as follows ; sleeve lobectomy, 8 cases [right upper : 6, left upper : 1, right middle : 1 : bronchial segmental resection without pulmonary resection, 2 cases : sleeve bi-lobectomy, 1 cases :patch dilating bronchoplasty with or without concomitant lobectomy in 7. There was no perioperative mortality. Morbidity in 4 patients included 1 transient recurrent laryngeal nerve palsy, 1 unstability of bronchial patch resulting atelectasis of afftected lung and 2 bronchial stenosis of anastomotic site.Throughout our experiences, we feel strongly that bronchoplastic procedure is a safe and effective surgical method preserving normal pulmonary tissue below affected bronchus for the wide range of various bronchial lesion including selected cases of bronchogenic carcinoma with acceptable complication and mortality.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2143-2159
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• 2011

The hybrid architecture of content delivery networks (CDN) and peer-to-peer overlay networks (P2P) is a promising technology enables effective real-time streaming services. It complements the advantages of quality control and reliability in a CDN, and the scalability of a P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues in deploying the CDN-P2P system. These issues result from biased peer selection without location awareness or content awareness, and can lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (iCDN-P2P) with a location/content-aware selection of peers. Specifically, a SuperPeer network makes a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through a performance evaluation, we show that the proposed architecture outperforms the original CDN-P2P hybrid architecture in terms of connection setup delay and media delivery time.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.808-812
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• 2008

In recent years, the software vulnerability becomes an important problem to the safety in operating system kernel. Many organizations endeavor to publish patches soon after discovery of vulnerability. In spite of the effort, end-system administrators hesitate to apply the patches to their system. The reasons of hesitation are the reboot disruption and the distrust of patches. To solve this problem we propose a dynamic update system for non-updatable kernel, named DUNK. The DUNK provides: 1) a dynamic update mechanism at function-level granularity to overcome the reboot disruption and 2) a safety verification mechanism to overcome the distrust problem, named MAFIA. In this paper, we describe the design of DUNK and detailed algorithm of MAFIA.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.551-558
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• 2007

From the view point of biological wastewater treatment, C/N ratio is one of the most important factor in biological nutrient removal process. However, municipal sewage in Korea is characterized by extremely low content of carbon source and relatively higher portion of N source. Accordingly, it is necessary to dose external carbon source in order to obtain higher degree of carbon source within the process. In this study, the effects of pH pretreatment as an alternative plan for increasing carbon source on the cell disruption and COD solubility of waste activated sludge were conducted under well defined experimental conditions. During 5 hours, the value of COD solubilization rate ($S_R$) at pH 11.5 is approximately 4.4 times higher than the value of $S_R$ at pH 9.5. It is expected that the level of SCOD increased due to the result from cell disruption. However, VSS/TSS ratio was not significantly changed after 5 hours. As Alkalinity changes gradually from less than 15, 30 and 60 meq NaOH/L, average RBCOD/SCOD fraction showed 34, 36 and 45%,respectively.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.311-316
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• 2011

Objective : Stroke is the third leading cause of death in the Republic of Korea. Time is the most important factor in hyperacute stroke. Yet, there had been no protocol for mechanical thrombolysis. We have treated patients with hyperacute stroke by mechanical thrombolysis for 3 years. In current study, we analyzed the outcome of mechanical thrombolysis. Methods : From March 2008 to February 2011, 36 patients were treated with mechanical thrombolysis. Initially we treated the patients by aggressive mechanical clot disruption (AMCD) who were admitted within 6 hours after the symptom onset. If revascularization was not achieved, balloon angioplasty was performed, followed by stenting or temporary endovascular bypass was performed. The result in 15 cases was not so successful. Since then, we started using the thromboaspiration method as the first line treatment of the mechanical thrombolysis. Results : After using the thromboaspiration, we had better results in recanalization rate, modified Rankin Score (mRS) and reperfusion injury compared to AMCD. The recanalization rate was 80.85%, mRS is 2.85, and there was only 0.09% hemorrhagic formation. Conclusion : Even though thromboaspiration is not statistically significant due to the limited numbers of patients enrolled in this study, we think it is a good way in mechanical thronbolysis for hyperacute stroke.