• 한국지하수토양환경학회지:지하수토양환경
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• 제6권3호
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• pp.93-106
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• 2001

장기적인 강수량 및 지하수위 관측과 강수, 지표수 및 지하수에 대하여 동위원소모니터링을 수행함으로써, 여수지역 소규모 수계에서의 지표수와 지하수 상관관계 및 지하수의 함양특성을 고찰하였다. 지표수 및 지하수의 동위원소조성은 강우량과 강우의 동위원소조성에 직접적으로 영향을 받고 있음을 보여준다. 또한 강우량이 약 20mm이하일 경우는 강우가 지하수로 침투되지 못함을 나타낸다. 지하수의 동위원소조성은 2000년 6월과 9월사이 발생한 12번의 각 강우사건에 의해 변화된 후, 다시 지하수 저류체의 조정으로 변화되는 양상을 확인하였다. 이는 모니터링된 강우 초기에는 강우가 상층부로부터 지하수체계로 유입되고 있음을 보여준다. 혼합방정식을 이용하면 갈수기 이후 첫 번째 강우의 지하수에 침투비율은 16.5%로 산출된다. 지하수의 함양특성에 대하여 기존 방법과 결부시켜, 보완된 동위원소방법을 적용한다면, 지하수 함양율을 보다 정량적으로 평가할 수 있을 것으로 판단된다.

• Parasites, Hosts and Diseases
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• 제29권3호
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• pp.227-234
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• 1991

1990연 6월부터 9월 사이에 강원도 횡성군의 백로 서식지에서 12마리의 중대백로를 포획하여 소장 내의 흡충류 감염 상태를 조사하고 아울러 검출된 흡충의 형태 특징을 관찰하여 종을 분류한 결과 5종의 흡충 Metagonimus sp. (67%), Centrocestus armntus(67%), Echinochasmus japonicus(50%), Strigea falconis(83%)와 Diplostomidae요(33%) 감염이 분류동정되었다. 이상의 결과로 중대백로는 인수공통기생충의 보유숙주로서 중요한 인체 기생충의 매개조류임을 알 수 있었다. Key words: Metagonimus sp., Centrocestus armatus, Echinochasmus iaponicus, Strigea falconis, Diplostomidae, Egrets, Hoengseong-gun (Kangwon Province)

• Parasites, Hosts and Diseases
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• 제42권3호
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• pp.93-119
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• 2004

Acanthamoeba and Naegleria are widely distributed in fresh water, soil and dust throughout the world, and cause meningoencephalitis or keratoconjunctivitis in humans and other mammals. Korean isolates, namely, Naegleria sp. YM-1 and Acanthamoeba sp. YM-2, YM-3, YM-4, YM-5, YM-6 and YM-7, were collected from sewage, water puddles, a storage reservoir, the gills of a fresh water fish, and by corneal washing. These isolates were categorized into three groups based on the mortalities of infected mice namely, highly virulent (YM-4), moderately virulent (YM-2, YM-5 and YM-7) and nonpathogenic (YM-3). In addition, a new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Korean isolate YM-4. The morphologic characters of its cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Based on experimentally infected mouse mortality, Acanthamoeba YM-4 was highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. Moreover, an anti-Acanthamoeba YM-4 monoclonal anti-body reacted only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of a 188 small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster based on phylogenic distances. Thus Acanthamoeba YM-4 was identified as a new species, and assigned Acanthamoeba sohi. Up to the year 2002 in Korea, two clinical cases were found to be infected with Acanthamoeba spp. These patients died of meningoencephalitis. In addition, one case of Acanthamoeba pneumonia with an immunodeficient status was reported and Acanthamoeba was detected in several cases of chronic relapsing corneal ulcer, chronic conjunctivitis, and keratitis.

• Parasites, Hosts and Diseases
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• 제57권6호
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• pp.647-656
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• 2019

Isthmiophora hortensis (Digenea: Echinostomatidae) is a dominant echinostome in animal reservoir hosts and humans in the Republic of Korea (Korea). We intended to investigate the infection status with this echinostome species in the several species of wild animals and describe the morphological characteristics in the faunistic view point. A total of 175 animal carcasses belonging to 3 families, i.e., Canidae, Felidae and Mustelidae, were collected from the southern regions of Korea from March 2010 to July 2017. Isthmiophora spp. worms were recovered from the small intestines of each animal under a stereomicroscope after washing of intestinal contents. Isthmiophora hortensis was recovered from 4 species of wild carnivores, i.e., Nyctereutes procyonoides (3/107: 2.8%), Mustela sibirica (11/31: 35.5%), Meles lucurus (2/3: 33.3%) and Martes flavigula (1/2: 50%). The other 3 carnivores comprising stray dogs, cat and leopard cat were negative for I. hortensis infection (0/2, 0/10 and 0/12, respectively). Specimens obtained from the Lutra lutra (6/8: 75%) were identified as a distinct species, I. inermis, by morphological comparison. Isthmiophora inermis has thinner body, elongate testes and different anterior limits of vitelline fields. Detailed morphological descriptions and comparisons with the morphological characteristics are provided. Conclusively, it was confirmed for the first time that 3 species of mustelid mammals, i.e., M. sibirica, M. lucurus, and M. flavigula, are to be the new definitive hosts of I. hortensis in Korea. Additionally, I. inermis is to be newly added in the Korean echinostome fauna.

• Journal of Microbiology and Biotechnology
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• 제29권2호
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• pp.274-282
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• 2019

Mercury-resistant ($Hg^R$) bacteria were isolated from heavy metal polluted wastewater and soil collected near to tanneries of district Kasur, Pakistan. Bacterial isolates AZ-1, AZ-2 and AZ-3 showed resistance up to $40{\mu}g/ml$ against mercuric chloride ($HgCl_2$). 16S rDNA ribotyping and phylogenetic analysis were performed for the characterization of selected isolates as Bacillus sp. AZ-1 (KT270477), Bacillus cereus AZ-2 (KT270478) and Bacillus cereus AZ-3 (KT270479). Phylogenetic relationship on the basis of merA nucleotide sequence confirmed 51-100% homology with the corresponding region of the merA gene of already reported mercury-resistant Gram-positive bacteria. The merE gene involved in the transportation of elemental mercury ($Hg^0$) via cell membrane was cloned for the first time into pHLV vector and transformed in overexpressed C43(DE3) E. coli cells. The recombinant plasmid (pHLMerE) was expressed and the native MerE protein was obtained after thrombin cleavage by size exclusion chromatography (SEC). The purification of fusion/recombinant and native protein MerE by Ni-NTA column, dialysis and fast protein liquid chromatography (FPLC/SEC) involved unfolding/refolding techniques. A small-scale reservoir of wastewater containing $30{\mu}g/ml$ of $HgCl_2$ was designed to check the detoxification ability of selected strains. It resulted in 83% detoxification of mercury by B. cereus AZ-2 and B. cereus AZ-3, and 76% detoxification by Bacillus sp. AZ-1 respectively (p < 0.05).

• 한국물환경학회지
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• 제34권6호
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• pp.569-578
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• 2018

To minimize the negative alterations in hydrologic and water quality environment in urban areas due to urbanization, Low Impact Development (LID) techniques are actively applied. In Korea, LID facilities are classified as Non-point Pollution Reduction Facilities (NPRFs), and therefore they are evaluated using the performance evaluation method for NPRFs. However, while LID facilities are generally installed in small, distributed configuration and mainly work with the infiltration process, the existing NPRFs are installed on a large scale and mainly work with the reservoir process. Therefore, some limitations are expected in assessing both facilities using the same method as they differ in properties. To solve these problems, in this study, a new method for performance evaluation was proposed with focus on bio-retention LID facilities. EPA SWMM was used to reproduce the hydrologic and water quality phenomena in study area, and SWMM-LID module used to simulate TP interception performance by installing a bio-retention cell under various conditions through long-term simulations. Finally, an empirical formula for Load Capture Ratio (LCR) was derived based on storm water interception ratio in the same form as the existing method. Using the existing formula in estimating the LCR is likely to overestimate the performance of interception for non-point pollutants in the extremely low design capacity, and also underestimate it in the moderate and high design capacity.

• Clinical and Experimental Reproductive Medicine
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• 제49권1호
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• pp.9-15
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• 2022

The angiotensin-converting enzyme 2 receptor (ACE2) appears to be widely expressed in cells in the testes, predominantly in spermatogonia, Sertoli cells, and Leydig cells, and its co-expression with transmembrane protease serine 2 (TMPRSS2) is essential for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For this reason, the male reproductive system could be considered a potential target for SARS-CoV-2, as well as a possible reservoir of infection. However, to date, there is very little evidence about the presence of SARS-CoV-2 in semen and testicular samples. The aim of this paper was to review the current evidence regarding the impact of SARS-CoV-2 on male fertility and sexual health, with a particular focus on reproductive hormones, the presence of the virus in seminal fluid and testis, and its impact on fertility parameters. We found very limited evidence reporting the presence of SARS-CoV-2 in semen and testicular samples, and the impact of SARS-CoV-2 on reproductive hormones and fertility parameters is unclear. The quality of the examined studies was poor due to the small sample size and several selection biases, precluding definitive conclusions. Hence, future well-designed prospective studies are needed to assess the real impact of SARS-CoV-2 on male reproductive function.

• 생태와환경
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• 제56권1호
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• pp.83-93
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• 2023

This study compares the abundance and community structure of zooplankton organisms from pelagic regions, and considers particularly the trophic levels vs. zooplankton abundances and biomass. Zooplankton samples were collected three times from May to November 2022, at 30 temperate lakes and reservoirs, which belong to four different river basins. The total zooplankton abundance, biomass and species index were showed considerable spatial variation. The spatial pattern of rotifer abundance was similar to that of total zooplankton abundance, while there were not showed similar patterns of zooplankton biomass (㎍ L^-1) in lentic ecosystems. The rotifer strongly dominated the zooplankton assemblage in smaller lentic system than that of larger. A total of 130 species of zooplankton were identified (83 rotifers, 34 cladocerans and 13 copepods). The total average of zooplankton abundance and biomass were 213.7±342.3 Ind. L^-1 (n=129) and 1382.8±1850.4 ㎍ L^-1, respectively. Total and average of zooplankton abundance were usually dominated by the rotifers (>56.9%), while those of zooplankton biomass were dominated by the cladocerans and copepods (>73.6%) in lentic ecosystems. Considering the Trophic State Index (TSI), the factors of zooplankton abundance and biomass were included in between meso- and eutrophic states(27 lakes, 90% of all). The mean abundance and biomass of zooplankton in eutrophic systems were higher than that of meso- and hypertrophic systems. From this result, we suggest that management strategy for the lentic ecosystem water environment has to be focused more on small-sized lakes and reservoirs, in terms of zooplankton assemblages.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.710-724
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• 2024

Flavobacterium can synthesize xanthophyll, particularly the pigment zeaxanthin, which has significant economic value in nutrition and pharmaceuticals. Recently, the use of carotenoid biosynthesis by bacteria and yeast fermentation technology has shown to be very efficient and offers significant advantages in large-scale production, cost-effectiveness, and safety. In the present study, JSWR-1 strain capable of producing xanthophyll pigment was isolated from a freshwater reservoir in Wanju-gun, Republic of Korea. Based on the morphological, physiological, and molecular characteristics, JSWR-1 classified as belonging to the Flavobacterium species. The bacterium is strictly aerobic, Gram-negative, rod-shaped, and psychrophilic. The completed genome sequence of the strain Flavobacterium sp. JSWR-1 is predicted to be a single circular 3,425,829-bp chromosome with a G+C content of 35.2% and 2,941 protein-coding genes. The optimization of carotenoid production was achieved by small-scale cultivation, resulting in zeaxanthin being identified as the predominant carotenoid pigment. The enhancement of zeaxanthin biosynthesis by applying different light-irradiation, variations in pH and temperature, and adding carbon and nitrogen supplies to the growth medium. A significant increase in intracellular zeaxanthin concentrations was also recorded during fed-batch fermentation achieving a maximum of 16.69 ± 0.71 mg/l, corresponding to a product yield of 4.05 ± 0.15 mg zeaxanthin per gram cell dry weight. Batch and fed-batch culture extracts exhibit significant antioxidant activity. The results demonstrated that the JSWR-1 strain can potentially serve as a source for zeaxanthin biosynthesis.

• Journal of Gastric Cancer
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• 제4권4호
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• pp.242-251
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• 2004

목적: 최근 조기위암 환자가 증가하기 때문에 수술 후 환자의 영양상태 개선을 포함한 삶의 질에 많은 관심이 모아지고 있다. 그러나 원위부 위절제 후 많이 이용되고 있는 Billroth-I, II 및 Roux-en-Y 술식은 남은 위의 작은 용량과 십이지장 우회에 따른 철분, 지방, 칼슘, 카로틴 등의 흡수 장애 등의 단점이 있다. 이를 보완하고자 저자들은 위 원위부 절제 후 소장낭을 저장소 역할을 하게 하고, 또한 십이지장과 문합하여 음식물이 생리적 방향으로 통과하도록 공장낭 간치술을 시행하였다. 대상 및 방법: 2001년 3월부터 2004년 2월까지 가톨릭의과대학 성가병원 외과에서 위암으로 원위부 절제를 시행한 196예를 공장낭 공장낭 간치술(JPI 군, n=100), B-I 군(n=29), B-II군(n=67)으로 나누어, 혈액 및 생화학적 검사의 변화, 몸무게를 포함한 영양학적 변화 및 위내시경 소견과 위 배출시간을 분석하였다. 결과: 환자들의 체중은 3군 모두 술 후 6개월에 최대로 감소된 후 회복되는 경향을 보였으며, 술 후 6개월, 1년, 2년째의 체중 감소율이 JPI군이 $5.14\%,\;3.01\%,\;2.37\%$로 B-I 군의 $8.41\%,\;6.69\%,\;5.90\%$B-II 군의 $7.50\%,\;7.65\%\;5.86\%$에 비해 의의있게 작았다(P=0.011, P=0.000, P=0.013). 검사실 소견은 술 후 6개월에 총 단백이 JPI 군이 B-I과 B-II 군보다 더 높았으며, 특히 1,2기 위암 환자의 경우 술 후 1년째 총 단백과 알부민이 JPI군에서 의의있게 높았다. 그러나 빈혈과 관련된 검사 칼슘, 인, 콜레스테롤, 트리글리세라이드 등에서는 3군 간의 차이는 관찰되지 않았다. 술 후 6개월, 1년, 2년째의 $\^{99m}$Tc-반 고형식(샌드위치)를 이용한 위 배출시간은 JPI 군이 102.5분, 83.1분, 58.1분, B-I 군이 95.5분, 92.0분, 58.5분, B-II 군이 53.9분, 69.1분, 50.2분으로 B-II 군이 가장 빠르고, JPI군이 가장 느리게 관찰되었다. 또한 위 내시경 검사 상 술 후 6개월째 정밀관찰이 불가능한 음식 저류가 JPI 군에서 가장 많았으나 시간이 지나면서 호전되는 것을 관찰하였다. 결론: 공장낭을 이용한 간치술은 기존 술식보다 1시간 정도 수술시간이 더 걸리고, 수술 후 초기에 위 배출시간이 지연되는 경향이 있지만, 몸무게를 포함한 영양학적인 면을 고려할 때, 장기 생존이 기대되는 제 I, II기 위암 환자에게 적용될 수 있는 또 하나의 좋은 재건 술식이라고 생각한다.