• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.76-76
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• 2012

Surface engineering of polymers has a broad array of scientific and technological applications that range from tissue engineering, regenerative medicine, microfluidics and novel lab on chip devices to building mechanical memories, stretchable electronics, and devising tunable surface adhesion for robotics. Recent advancements in the field of nanotechnology have provided robust techniques for controlled surface modification of polymers and creation of structural features on the polymeric surface at submicron scale. We have recently demonstrated techniques for controlled surfaces of soft and relatively hard polymers using ion beam irradiation and plasma treatment, which allows the fabrication of nanoscale surface features such as wrinkles, ripples, holes, and hairs with respect to its polymers. In this talk, we discuss the underlying mechanisms of formation of these structural features. This includes the change in the chemical composition of the surface layer of the polymers due to ion beam irradiation or plasma treatment and the instability and mechanics of the skin-substrate system. Using ion beam or plasma irradiation on polymers, we introduce a simple method for fabrication of one-dimensional, two-dimensional and nested hierarchical structural patterns on polymeric surfaces on various polymers such as polypropylene (PP), polyethylene (PE), poly (methyl methacrylate) PMMA, and polydimethylsiloxane (PDMS).

• Journal of fish pathology
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• v.22 no.1
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• pp.15-21
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• 2009

White spot syndrome virus (WSSV) is a strong causative agent for high mortality in cultured and wild shrimps. From this study, the WSSV prevalence in marine organisms around shrimp farm as well as live feed-mediated transmission of WSSV to farmed shrimps were investigated. Based on nested-PCR method, WSSV was detected in wide array of marine organisms including Perinereis aibuhitensis (81.3% of prevalence rate, 13/16), Enedrias fangi (100%, 16/16), Ruditapes philippinarum (20%, 2/10), crab larvae (100%, 10/10), copepoda (30%, 3/10), Periophthalmus modestus (50%, 5/10), Pachygrapsus crassipes (10%, 1/10), Helice tridens (20%, 2/10) and Neomysis sp. (70%, 7/10). On the other hand, WSSV was not detected in Bullacta exarata, Uca arcuata, and Reishia clavigera. The percent prevalence of WSSV in wild shrimps, Fenneropenaeus chinensis was only 6%, but markedly increased up to 56% after a feeding trial using polychaete worms for one month, indicating that the live feed is one of significant carriers of WSSV to shrimps under practical farming conditions.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3773-3778
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• 2014

Background: The study was aimed to evaluate the prevalence and genotype distribution of HPV infection in vulvar squamous cell carcinoma (SCC) in northern Thailand and the clinicopathological difference with regard to HPV infection status. Materials and Methods: Formalin-fixed paraffin-embedded tissue samples of vulvar SCC diagnosed between January 2006 and December 2012 were collected. HPV infection was detected by nested polymerase chain reaction (PCR) with primers MY09/11 and GP5+/6+. HPV genotyping was performed using the Linear Array Genotyping Test, followed by type-specific PCR targeting the E6/E7 region of HPV16/18/52 if the Linear Array test was negative. The histologic slides of vulvar lesions and the medical records were reviewed. Results: There were 47 cases of vulvar SCC included in the study (mean patient age $57.9{\pm}13.2$ years). HPV infection was detected in 29 cases (62%), all of which had single HPV infections. HPV16 accounted for 23 (49%). The patients with HPV-positive SCC had a significantly younger mean age than those with HPV-negative tumors (52.7 years vs 66.2 years, p<0.001). There was no significant difference in tumor stage distribution with regard to the status of HPV infection. The presence of vulvar intraepithelial neoplasia (VIN) of usual type (basaloid or warty) was significantly more frequent in HPV-positive cases compared with HPV-negative cases (62% vs 6%, p<0.001), whereas differentiated-type VIN was more common in HPV-negative cases (24% vs 0%, p=0.019). Conclusions: HPV infection was detected in 62% of vulvar SCC in northern Thailand. HPV16 was the predominant genotype similar to the data reported from other regions. HPV-positive SCC occurred in younger patients compared with HPV-negative SCC, and was associated with usual-type VIN. Vaccination against HPV16/18 may potentially prevent almost one half of vulvar SCC in northern Thailand.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.609-617
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• 2020

Plasmodium vivax reemerged in 1993. It has been sustained for more than 25 years and become one of the important indigenous parasitic diseases in northern and western parts of the Republic of Korea near the demilitarized zone. In particular, relapse is a significant concern for the control of malaria, as short- and long-term incubation periods vary among those infected in Korea. In this study, the prevalence of asymptomatic carriers was examined among residents of high endemic areas of vivax malaria during nonseasonal transmission of mosquitoes. Blood samples from 3 endemic regions in northwestern Korea were evaluated by microscopic examination, rapid diagnostic testing, and nested PCR to identify asymptomatic patients carrying malaria parasites in the community. However, no positive malaria case among residents of endemic areas was detected. Additionally, serological analysis was carried out to measure antibodies against 3 antigenic recombinant proteins of P. vivax, merozoite surface protein 1-19, circumsporozoite surface protein-VK210, and liver-stage antigen (PvLSA-N), by the protein array method. Interestingly, seropositivity of sera between previous exposure and samples without exposure to malaria was significantly higher using the PvLSA-N antigen than the other antigens, suggesting that PvLSA-N can be used as a serological marker to analyze the degree of exposure for malaria transmission in endemic areas. This indicates a very low asymptomatic carrier prevalence during the nonmalaria season in the endemic areas of Korea.