Helicobacter pylori are known as a causative agent of gastritis, gastric duodenum and peptic ulcer, and gastric cancer, and multiple drug use is associated with various side effects in patients. The discovery of antibacterial substances against H. pylori from Korean resource plants is an important substitute for antibiotics. 52 species of Korean resource plants were collected and extracted with 50% ethanol, and antibacterial activity against H. pylori was measured using the disk diffusion method. The toxicity of plant extracts to human gastric adenocarcinoma(AGS) cells was measured by MTT assay, and the level of IL-8 secreted when gastric epithelial cells were inoculated with H. pylori was measured. As a result of measuring the antibacterial activity of H. pylori, antibacterial activity was confirmed in 38 plant extracts. The plant species with the strongest antibacterial activity were Chrysanthemum indicum, Rheum rhabarbarum, Patrinia scabiosaefolia and Petasites japonicus. C. indicum was not cytotoxic to H. pyroli-infected AGS cells and showed anti-inflammatory effects. This study's results can be used to develop healthy, functional foods and medical materials.
말라리아는 Anopheles 모기들에 의해 전파되며, 대한민국에서는 코로나 팬데믹 기간 동안(2020~2022) 약 200~300명대의 말라리아 환자가 발생하였으나, 지난 2023년에는 그 수가 폭증해 약 800명의 환자가 발생하였다. 현재까지 모기를 방제하기 위한 가장 효율적인 수단은 살충제를 사용한 방제이나, 지속적으로 이러한 화합물에 노출된 모기 개체군은 살충제에 저항성을 갖게 되는 것으로 알려져 있다. 이에 본 연구에서는 대한민국의 주요 말라리아 발생 지역인 비무장지대 부근 및 이외 지역인 용산, 평택, 오산에서 채집을 진행하였으며, 채집된 An. sinensis에 대해서 살충제 저항성과 관련되어 있다고 알려진 유전자인 acetylcholinesterase-1(ace-1)와 voltage-gated sodium channel(vgsc) 영역에 대한 저항성 돌연변이 보유 여부를 각각 확인하였다. 실험 결과 채집된 모든 지역에서 G119S(ace-1), L1014F,C(vgsc) 돌연변이가 발견되었으며, 그 빈도는 계절과 장소에 따라 차이를 나타내었다. 본 실험 결과는 향후 말라리아 감염 억제를 위한 매개체 연구에 활용될 수 있을 것으로 기대된다.
한강 3개 보 구간 수변부 11개 지점을 대상으로 2023년 총 2회 채집된 저서성 대형무척추동물은 총 100종 평균 426.0 개체/m2였다. 여주보에서 64종으로 가장 많이 출현하였고, 강천보에서 59종, 이포보에서 54종, 한강보상류 에서 41종, 한강보하류에서 32종이 확인되었다. 전체 평균 개체밀도는 강천보에서 944.1 개체/m2로 가장 많았고, 한강보상류에서 282.7 개체/m2, 여주보에서 251.9 개체/m2, 이포보에서 180.6 개체/m2, 한강보하류에서 172.9 개체 /m2 순으로 확인되었다. 한강 보 구간에서는 플라나리아류, 실지렁이, 깔따구류 등이 우점함. 보구간의 특성상 상대적으로 단순한 하상 및 깊은 수심에 적응성이 높은 실지렁이, 깔따구류의 우점은 일반적인 특성으로 볼 수 있으며 일시적으로 수변부에서 밀집된 플라나리아류의 채집이 이뤄져 우점된 결과를 보인 것으로 보임. 한강 보 구간 수변부 및 중앙부 조사지점별 군집분석을 실시한 결과 한강보 하류는 3개 보에 비해 우점도가 높고 다양도 와 풍부도가 낮았으며 전반적으로 상류부에 위치한 한강보상류 등의 지점에서 군집안정성이 확보되고 있는 것으로 보이며 이러한 점은 상대적으로 다양한 미소서식환경에 기인한 것으로 판단된다.
국내 원예작물에서 화분매개곤충의 의존도는 해마다 증가하고 있다. 우리는 사과, 딸기 등 화분매개곤충의 의존도가 높은 주요 과수와 시설작물에 대하여 화분매개곤충의 사용기술을 개발하고 이를 현장에 적용하는 연구를 수행하고 있다. 2021년부터 2022년까지 딸기, 키위 등 5가지 주요 농작물에서 화분매개벌을 적용한 결과, 딸기에서 뒤영벌의 적용결과 기존 꿀벌과 통계적으로 같은 수준의 화분매개효과를 나타내었으며, 하우스에서 농약적용시 하우스 밖으로 벌통을 위치시키는 것이 방치보다 벌의 소실을 20% 더 감소시킬 수 있었다. 인공수분 에 의존하고 있는 씨없는 수박에서 수분수 식재와 꿀벌을 이용함으로 기존 벌 방사보다 16% 착과율을 향상시킬 수 있었다. 시설고추에서 꿀벌과 뒤영벌의 혼합사용시 기존 꿀벌 방사보다 고추 수량이 10% 향상되었고, 토마토 에서 660㎡당 뒤영벌의 봉군량을 1.5배 증가시 토마토 수량은 4.4% 향상되었다. 키위는 꿀벌로 기존의 인공수분 을 충분히 대체할 수 있었고, 인건비가 60%이상 절감되었다. 또한 현재 시판중인 30종의 살충제와 27종의 살균제 에 대하여 24시간내 반수치사를 보인 농약은 각각 살충제 6종와 살균제 4종 이었다. 이어서 2023년부터 참외, 멜론, 사과, 단감에 대한 현장적용연구가 진행되고 있다.
Bacterial phytopathogen Pectobacterium causes soft rot disease in several vegetable crops globally, resulting in heavy agricultural losses at both the pre and postharvest stages. The present work was carried out to screen Kimchi cabbage genetic resources conserved at the National Agrobiodiversity Center, Rural Development Administration, Korea, for resistance against the soft rot pathogen Pectobacterium carotovorum subsp. carotovorum KACC 21701 over a period of three years (from 2020 to 2022). Infection of the phytopathogen was carried out at four-leaf stage and for each accession, twenty-five plants per germplasm were infected with KACC 21701. Kimchi cabbage cultivars Wangmatbaechu, Seoulbaechu, and CR Kiyoshi were used as control. Seven-days post-infection, the Disease Index (DI) values were manually recorded from zero to four, zero matched perfectly heathy plants and four completely dead plants. The 682 accessions of Kimchi cabbage exhibited varying degrees of disease resistance to KACC 21701 and thirty accessions, exhibiting a DI≤2, were considered for replication studies. During the replication studies, four landrace germplasms (IT102883, IT120036, IT120044, and IT120048) and one cultivar (IT187919) were confirmed to be moderately susceptible to KACC 21701. Results of the preliminary screening as well as replication studies were documented for the all the 682 germplasms. Addition of such information to the passport data of stored germplasms might serve as potential bio-resource for future breeders and researchers to develop resistant varieties or study the mechanisms involved in resistance of plants to such phytopathogen.
The bacterial soft-rot disease is one of the most critical diseases in vegetables such as Chinese cabbage. The researchers isolated two bacteria (Pseudomonas kribbensis and Pantoea vagans) from diseased tissue samples of Chinese cabbages and confirmed them as being the strains that cause soft-rot disease. Lactic-acid bacteria (LAB), were screened and used to control soft-rot disease bacteria. The researchers tested the treatments with hypochlorous acid water (HAW) and LAB supernatant to control soft-rot disease bacteria. The tests confirmed that treatments with the HAW (over 120 ppm) or LAB (Lactobacillus plantarum PL203) culture supernatants (0.5 mL) completely controlled both P. kribbensis and P. vagans.
Abstract In this study, micro-defects on/in carbon fibers were modified by irradiation with an electron beam, which improved the mechanical strength of single carbon fibers. The electron beam irradiation was 10 kGy (using a 1.5 MeV accelerator in the air). The total doses ranged from 100 to 500 kGy. The tensile strength of the single carbon fiber was measured using a universal testing machine. The micro-defects on the fiber surface were observed with scanning electron microscopy and atomic force microscopy, and those in the fiber were evaluated by Raman spectroscopy. In conclusion, the electron beam treatment produced changes in the micro-defects on/in the carbon fibers, resulting in up to 14% improvement in the tensile strength of single carbon fiber.
In Korea livestock farms breeding cattle have been suffering from re-emerging problems of Brucella (B.) abortus infection while steady decline of bovine brucellosis. Therefore, this study underscored the identification and association of etiological agent of brucellosis in cattle in South Korea. The incidence of brucellosis in cattle was analyzed by bacteriological and molecular methods in 187 brucellosis-suspicious farms of 11 regions between 2018 and 2020. Brucella isolates from various specimens were identified by Brucella-specific multiplex PCR. Epidemiological data were collected by local official veterinarians through history taking from farmers and animal data systems. In 230 of 560 cattle (40.9%) and 94 of 187 farms (50.3%), a total of 313 B. abortus were isolated from various specimens, the majority of isolates were from supramammary lymph node (41%). In epidemiological findings, the majority of positive cases were mainly caused by resurgence (43.7%) and unknown (37.2%). Of 94 positive cases isolated B. abortus, abortion in cattle infected by B. abortus occurred in 51 farms (54.3%) where led to resurgence in 30 farms and environmental survival of B. abortus in 9 farms. Consequently, these findings revealed the existence of etiological agent of bovine brucellosis in Korea, which still occurred at low levels in distinct regions where are allowed to call for persistent biosecurity. Thus, we highlight that brucellosis in Korea needs to take more effective control strategies with potential evidence. Moreover it is ultimately important to maintain a constant monitoring for eradication of brucellosis.
Giant miscanthus (GM) is an Asian grass that can produce biomass in high yields per land area. It can be used as a cathode material in lithium sulfur (Li/S) batteries. Giant-miscanthus-derived activated carbon (GMAC) is prepared via carbonization of GM followed by KOH activation. It is prepared with a large amount of KOH, and thus contained more defects but had a highly porous structure and graphitic cluster lattice. GMAC has a large specific surface area of 3327 m2/g and a large total pore volume of 1.86 cm3/g. The pore volume served as a storage space for the retention of polysulfides, thereby inhibiting the shuttle effect. When a GMAC–sulfur composite cathode is tested in a Li/S battery, an initial discharge capacity of 1148 mAh/g can be attained at 0.1 C. In a cyclic charge–discharge experiment at 1 C, discharge capacities of 529 mAh/g and 248 mAh/g are observed in the first and 200th cycles, respectively.