• 대한치과기공학회지
• /
• 제22권1호
• /
• pp.145-152
• /
• 2000

In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.

• Parasites, Hosts and Diseases
• /
• 제54권2호
• /
• pp.215-219
• /
• 2016

Clonorchis sinensis is currently the most important parasite affecting public health problems in the Republic of Korea. We investigated the prevalence of C. sinensis infection among residents living along 5 major rivers in Korea. A total of 42,562 individual stool samples were collected from 37 localities and examined using the formalin-ether sedimentation technique. Helminth eggs were detected in 4,052 (9.5%) residents and 3,586 (8.4%) were infected with C. sinensis. The egg positive rate of C. sinensis in Nakdong, Seomjin, Geum, Yeongsan, and Han River was 11.7%, 9.9%, 6.5%, 3.1%, and 1.0%, respectively. The overall prevalence of clonorchiasis by sex was 11.2% in males and 6.2% in females. The age-prevalence was the highest in the 50-59 years band. It has been reconfirmed that the endemicity of clonorchiasis is higher in southern areas of Korea, especially along Nakdong and Seomjin Rivers. A combination of continuous control programs with health education initiatives is urgently required in these highly endemic areas of clonorchiasis in Korea.

• 한국환경복원기술학회지
• /
• 제6권6호
• /
• pp.1-13
• /
• 2003

This study aims at conducting an awareness survey of three parties, namely, citizens, government officials, and developers for improvement of urban landscape and, based on the survey result, to suggest a direction to develop a landscape plan for improvement of urban landscape of Yong-in city in the future. The summary of this study is as follows. First, in case of Yong-in, the main drivers of forest landscape destruction were "residential complexes developed for apartment buildings" and "golf courses", the driver of river landscape damage was "the status of cleanliness of riverside and poor facilities", the driver of roadside landscape damage was "construction sites" that completely eliminate original natural landscape in both citizen and government official groups. When granting development-related approvals in the future, appropriate actions should be prepared such as developing a landscape management guideline or including a landscape plan in advance to assure plans and designs fully reflecting landscape. Second, citizens' commitment to participate in urban landscape creation and improvement was rated high at even willing to tolerate regulations including restriction of property rights. In the future, landscape improvement programs allowing resident participation should be developed proactively. The roles of government officials include preparing various criteria at a city level and convincing and guiding citizens to initiate landscape improvement project together with citizens and developers through proactive efforts by government officials. Third, the role of developers would be to realize development projects conserving local environment and/or harmonizing with local natural environment before preparing a development plan or launching construction rather than offering various considerations after executing development projects.

• 한국농촌건축학회논문집
• /
• 제9권1호
• /
• pp.61-68
• /
• 2007

Rutian village is situated at the lower stream of Tumen river- U shaped entrance which is around many small mountains. This village which can be entered through the ferry of the HyoRyongBong village had started to be founded before the "Korean village"was founded. It was cultivated by Chinese, but because of the increasing number of the Korean immigrants, it finally became the village for only Korean Chinese. It has become from the very small village in the reclamation period to the prosperous one containing 45 houses in the Cultural Revolution period. Unfortunately, after adopting the Open policy, the village got smaller and contained only 15 houses. The reasons were: many young people emigrated to big cities for economic security and the education of their children; some went abroad to get job. To see the space structure for the village, streets and the roads, which can connect 130-year-old village to the villages around it, were opened as national roads. Bat these roads disappeared and also were not used much because of the decreasing number of resident population. The residence has become from the very small village in the reclamation period to the prosperous one and then become a smaller one again now. Especially, front villages and remote villages have started to disappear. Moreover, because of a good geographical condition such as the mountain and the water, fish farms have been much built up, and so houses with business facilities have started to build up.