장내 미생물 군집은 소화 과정, 면역 시스템, 질병 발생 등 숙주의 다양한 면에 광범위한 영향을 주는 것으로 알려져 있으며, 주요 장내 미생물 종은 숙주의 생리 기능에 핵심적인 역할을 수행한다고 발표된 바 있다. 곤충의 장내 미생물 군집에 관한 연구가 최근 활발히 이루어지고 있으며, 이들 연구는 주로 장내 미생물 군집과 기생충, 병원체 간의 상호작용, 종간의 신호 전달 네트워크, 먹이의 소화 과정 등을 중심으로 이루어지고 있다. 이러한 연구들은 대부분 Illumina MiSeq을 활용하여 16S rRNA 유전자의 V1부터 V9 영역 중 선택된 특정 부분을 대상으로 짧은 서열 정보를 대상으로 진행되었다. 그러나, 최근에는 PacBio HiFi 기술이 상용화되면서 16S rRNA의 전장 분석이 가능할 수 있게 되었다. 이번 연구는 장수말벌(Vespa mandarinia)의 해부를 통해 gut과 carcass 부분을 분리한 뒤, 각 샘플을 Illumina MiSeq과 PacBio HiFi 기술을 활용하여 미생물 군집 간의 차이점을 확인하기 위하여 수행되었다.
Haemaphysalis longicornis는 사람과 동물에게 여러 심각한 병원체를 전달하는 주요 매개체로, 한반도에 널리 분포하고 있다. H. longicornis는 Rickettsia spp., Borrelia spp., Francisella spp., Coxiella spp., 그리고 중증열성혈소판 감소증후군 바이러스 (SFTS virus) 등을 매개하는 것으로 알려져 있다. 국내에 서식하는 H. longicornis의 미생물 군집과 관련된 연구는 많이 진행되지 않은 것으로 확인되었다. 이 연구는 한반도 내 다양한 지역에서 채집된 H. longicornis의 미생물군집 다양성을 지역별, 성장 단계 및 성별에 따라 분석하였다. 2019년 6월부터 7월까지 질병관리청 권역별기후변화매개체감시거점센터 16개 지역에서 채집한 H. longicornis의 16S rRNA 유전자 V3-V4 영역을 PCR로 증폭 후 Illumina MiSeq 플랫폼으로 시퀀싱하였다. Qiime2를 활용한 미생물 다양성 분석을 통해 총 46개의 샘플에서 1,754,418개의 non-chimeric reads를 얻었으며, 평균 126개 의 operating taxonmic unit (OTU) 을 식별하여 총 1,398개의 OTU를 확인하였다. 대부분의 지역에서 Coxiella spp.가 우점종으로 나타났으며, 특히 Coxiella endosymbiont는 가장 높은 우점도를 보이며, Coxiella burnetii와 계통 발생 학적으로 유사한 것으로 확인되었다. 이 연구를 통해 분석된 결과는 각 지역의 H. longicornis 미생물군집 데이터 베이스 구축에 활용되었으며, 이를 통해 지역별 미생물군집의 특이성을 식별할 수 있게 하였다. 이는 한반도의 H. longicornis에 의한 질병 전파 연구와 이를 통한 공중보건 개선에 기여할 것으로 기대된다.
Calonecrinae represent a unique but small subfamily of Nitidulidae that is endemic to South Asia. Their habitats, the South Asian lowland forests, are under the imminent threat of degradation, posing a risk of rapid extinction for these species in their specific locales. Despite the looming threat to their existence, our understanding of this enigmatic group remains limited. We conducted an examination of museum and newly collected specimens, alongside a review of the literature, leading to the discovery of a new species, Calonecrus mindanaoensis, from Mindanao, Philippines. For the first time, the morphology of all immature stages of the Calonecrinae was described, with detailed photographs including SEM images. Additionally, their natural history was uncovered for the first time, revealing that all life stages are uniquely adapted to spending their entire life cycle within sticky resin. We re-evaluated the phylogenetic placement of the Calonecrinae by constructing a phylogenetic tree based on the mitochondrial genome. Calonecrinae are positioned within the Epuraeinae clade and show significant affinity with the genus Trimenus. Consequently, this study proposes reclassifying Calonecrinae as Calonecrini stat nov, an extremely modified tribe within the Epuraeinae.
Intermuscular fat is essential for enhancing the flavor and texture of cultured meat. Mesenchymal stem cells derived from intermuscular adipose tissues are a source of intermuscular fat. Therefore, as a step towards developing a platform to derive intermuscular fat from mesenchymal stem cells (MSCs) for insertion between myofibrils in cultured beef, an advanced protocol of intermuscular adipose tissue dissociation effective to the isolation of MSCs from intermuscular adipose tissues was developed in cattle. To accomplish this, physical steps were added to the enzymatic dissociation of intermuscular adipose tissues, and the MSCs were established from primary cells dissociated with physical step-free and step-added enzymatic dissociation protocols. The application of a physical step (intensive shaking up) at 5 minutes intervals during enzymatic dissociation resulted in the greatest number of primary cells derived from intermuscular adipose tissues, showed effective formation of colony forming units-fibroblasts (CFU-Fs) from the retrieved primary cells, and generated MSCs with no increase in doubling time. Thus, this protocol will contribute to the stable supply of good quality adipose-derived mesenchymal stem cells (ADMSCs) as a fat source for the production of marbled cultured beef.
The Korea government decided to shut down Kori-1 and Wolsung-1 nuclear power plants (NPPs) in 2017 and 2019, respectively, and their decommissioning plans are underway. Decommissioning of a NPP generates various types of radioactive wastes such as concrete, metal, liquid, plastic, paper, and clothe. Among the various radioactive wastes, we focused on radioactive-combustible waste due to its large amount (10,000–40,000 drums/NPP) and environmental issues. Incineration has been the traditional way to minimize volume of combustible waste, however, it is no longer available for this amount of waste. Accordingly, an alternative technique is required which can accomplish both high volume reduction and low emission of carbon dioxide. Recently, KAERI proposed a new decontamination process for volume reduction of radioactivecombustible waste generated during operation and decommissioning of NPPs. This thermochemical process operates via serial steps of carbonization-chlorination-solidification. The key function of the thermochemical decontamination process is to selectively recover and solidify radioactive metals so that radioactivity of the decontaminated carbon meets the release criteria. In this work, a preliminary version of mass flow diagram of the thermochemical decontamination process was established for representative wastes. Mass balance of each step was calculated based on physical and chemical properties of each constituent atoms. The mass flow diagram provides a platform to organize experimental results leading to key information of the process such as the final decontamination factor and radioactivity of each product.
Globally, colon cancer is increased gradually and known as one of the major causes of cancer death. Stevia, a substitute of sugar, is known to have many components including alpha-tocopherol and anthocyanin etc, as antioxidants. This study's purpose is to investigate whether stevia plant extract can have a protective effect against colon carcinogenesis induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in mice. Total 30 male ICR mice were divided into 2 groups; AOM/DSS treatment (control group), AOM/DSS + stevia extract (0.5%, in drinking water). After acclimation for 1 week, five weeks old mice received three intraperitoneal AOM (10 mg/kg b.w.) injections weekly for 3 weeks (0–2nd weeks of the experiment) and 2% DSS as drinking water for the next one week. AIN-76A purified rodent diet and 0.5% stevia extract water were supplied to the animals for 6 weeks. The colons of mice were collected and the number of aberrant crypt foci (ACF) and aberrant crypts (ACs) in colonic mucosa were counted after staining with methylene blue. Malondialdehyde (MDA) concentration in feces were determined. The numbers of ACF and ACs were significantly (p<0.01) decreased in stevia-treated group compared with the control group. The MDA concentration in feces was also significantly (p<0.01) decreased in stevia-treated group compared with the control group. In histopathology of colonic epithelium, hyperplasia of colonic epithelium was less observed in steviatreated group. These results indicate that stevia has a protective effect against colon carcinogenesis induced by AOM/DSS in mice and further study needs to illustrate the protective mechanisms.
To enhance the thermal properties of epoxy composites, expanded graphite (EG) was oxyfluorinated and embedded into epoxy resin as a reinforcement. The maximum thermal conductivity was obtained for epoxy composites with oxyfluorinated EG, representing a 62% increase compared to that of neat epoxy. Additionally, the glass transition temperature (Tg) and integral procedural decomposition temperature of epoxy composites with oxyfluorinated EG show the increase of 6% (4.4 °C) and 106% (264 °C), respectively, which indicated the improvement in thermal stability. These results can be attributed to the interfacial interaction between epoxy and oxyfluorinated EG, which formed strong interfacial interactions between the epoxy resin and EG due to the presence of oxygen- and fluorine-containing functional groups in oxyfluorinated EG.
A residual contact vial plus water (RCVpW) bioassay method was established to monitor insectiside resistance in field populations of the melon thrips, Thrips palmi. Resistance level against six major insecticides were evalutated in five regions to test applicability of RCVpW as an on-site resistance monitoring tool. Reduced mortality in response to six test insecticides were exhibited compared to the RDA susceptable strain showing 100 % mortality, indicating different degree of resistance. An apparently reduced mortality to emamectin benzoate and chlofenapyr was observed in some field populations, suggesting uneven distribution of resistance to these insecticides in field populations. In addition, spinosad resistance was high and widely distributed in the test regions. Synergistic bioassay revealed that cytochrome P450-mediated metabolic factor is involved in spinosad resistance in the Korean population.
Samples were collected from benthic and subaerophytic habitats of fresh and brackish water in Korea from April 2017 to April 2018. Accordingly, three genera and seven species were newly recorded in Korea. Three unrecorded genera were Cephalothrix, Cyanophanon and Toxifilum, and seven species were Anagnostidinema pseudacutissimum, Calothrix elenkinii, Cephalothrix komarekiana, Cyanophanon mirabile, Cyanosarcina chroococcoides, Leptolyngbya ectocarpi and Toxifilum mysidocida. Anagnostidinema pseudacutissimum and Cephalothrix komarekiana had been previously reported to inhabit freshwater, but these were found to be present in brackish water during the period of the present study. Also, Cyanosarcina chroococcoides previously reported to inhabit moorland waters and swamps, were found to be present in subaerophytic habitat.
Six taxa of unrecorded Korean species of charophytes are described. Freshwater and aerial charophytes were collected from the bark of trees, reservoirs, small ponds and swamps from April 2017 to September 2017. The newly recorded species of Korea were Cosmarium quadrifarium f. octastichum, Euastrum turneri, Spondylosium nitens var. triangulare, Staurastrum kouwetsii, Staurodesmus dickiei var. latus, and Klebsormidium subtile. K. subtile was transferred from Stichococcus subtilis.
In 2017, the freshwater algae were collected from reservoirs, small ponds, soil, and rocks in Korea. Eight taxa of Chlorophyta (Chlorophyceae and Trebouxiophyceae) have been newly reported in Korea. The unrecorded indigenous species were Chlorolobion braunii, Coelastrum pseudomicroporum, Coelastrum reticulatum var. cubanum, Monoraphidium nanum, Tetrachlorella incerta, Ecdysichlamys obliqua, Gloeotila scopulina, and Stichococcus jenerensis.
Phytoplanktons were collected from various environments including small marshes, small ponds, reservoirs and brackish water from March 2017 to November 2017. In this study, five species of family Scenedesmaceae were newly recorded in Korea. The genus Desmodesmus was newly reported in Korea. The newly recorded species are Scenedesmus nanus, S. praetervisus, Desmodesmus costato-granulatus, D. lunatus and D. spinulatus. S. nanus and S. praetervisus are known to occur in freshwater, but they were found in the brackish water in this study.