Colon cancer has been considered a leading cause of cancer-associated death. Folic acid is a vitamin necessary for cellular physiological functions and cell viability. However, the association between folic acid intake and colon cancer has been examined in several prospective cohort studies are controversial. This study investigated the effects of folate intake on colon carcinogenesis and oxidative stress in an azoxymethane (AOM)/dextran sodium sulfate (DSS) institute for cancer research (ICR) mouse model. Thirty male ICR mice (5 weeks old) were divided into the control group and the experimental group supplied 0.03% folic acid via drinking water (50 mL/week/mouse) for 6 weeks. To induce colonic pre-neoplastic lesions, the animals were subcutaneously injected three times weekly with AOM (10 mg/kg body weight), followed by 2% DSS in drinking water for a week. Folic acid supplementation significantly suppressed the total number of aberrant crypt foci and aberrant crypts. Histological image data showed that folic acid supplementation attenuated neoplastic change. In addition, we measured the thiobarbituric acid reactive substances concentration of dry feces samples to identify the effect of folic acid on reactive oxygen accumulation. The folic acid supplementation group had reduced reactive oxygen species levels in dry feces compared to the control group. In conclusion, these findings indicate that folic acid suppresses colon carcinogenesis and oxidative stress in an AOM/DSS mouse model.

2D 퍼즐은 인기있는 보드게임이다. 2D 퍼즐을 완성하는 기술은 많이 연구되었다. 하지만 2D만으로는 대상 을 효과적으로 표현하기 어렵다는 한계가 있다. 본 연구에서는 영상으로부터 높이를 가진 2D+ 레고 퍼즐을 생성하는 방법을 제안한다. 이를 위해서 본 연구에서는 영상의 높이 맵과 분할 맵의 정보를 활용한다. 우리 는 2D+ 퍼즐에 적용하기위해 다양한 대상의 높이 및 영역 정보를 적절하게 처리해야한다. 이러한 이유로, 우리는 깊이 맵과 분할영역 맵을 추출하기 위해 모델에 심층 학습 모델을 적용한다. 높이 맵을 추출하기 위 해 우리는 CelebAMask-HQ dataset으로 학습한 BiseNet을 채택했다. 그리고 분할 맵을 얻기 위해 NYU Depth V2 dataset으로 학습한 DenseDepth를 사용했다. 입력 영상에 대해서 저해상도 영상 및 높이 맵과 분할 맵을 추출하고, 저해상도 영상을 레고 브릭의 색 팔레트를 적용한 영상에 대해서 높이 맵과 분할 맵 정보를 적용해서 높이를 가진 2D+ 픽셀 아트 영상을 생성한다. 그리고, 이 픽셀 아트 영상에 대해서 같은 높이와 같은 색을 가진 픽셀들에 대해서 최대한 큰 브릭을 적용하는 그리디 알고리즘을 적용해서 2D+ 레 고 퍼즐을 완성한다. 본 연구에서는 다양한 초상화를 대상으로 2D+ 레고 퍼즐을 완성하는 예를 제시하였으 며, 그 중 하나를 직접 제작하여 그 결과를 제시한다.

Recently, the demand for atypical structures with functions and sculptural beauty is increasing in the construction industry. Existing mold-based structure production methods have many advantages, but building complex atypical structures represents limitations due to the cost and technical characteristics. Production methods using molding are suitable for mass production systems, but production cost, construction period, construction cost, and environmental pollution can occur in small quantity batch production. The recent trend in the construction industry calls for new construction methods of customized small quantity batch production methods that can produce various types of sophisticated structures. In addition to the economic effects of developing related technologies of 3D Concrete Printers (3DCP), it can enhance national image through the image of future technology, the international status of the construction civil engineering industry, self-reliance, and technology export. Until now, 3DCP technology has been carried out in producing and utilizing residential houses, structures, etc., on land or manufacturing on land and installing them underwater. The final purpose of this research project is to produce marine structures by directly printing various marine structures underwater with 3DCP equipment. Compared to current underwater structure construction techniques, constructing structures directly underwater using 3DCP equipment has the following advantages: 1) cost reduction effects: 2) reduction of construct time, 3) ease of manufacturing amorphous underwater structures, 4) disaster prevention effects. The core element technology of the 3DCP equipment is to extrude the transferred composite materials at a constant quantitative speed and control the printing flow of the materials smoothly while printing the output. In this study, the extruding module of the 3DCP equipment operates underwater while developing an extruding module that can control the printing flow of the material while extruding it at a constant quantitative speed and minimizing the external force that can occur during underwater printing. The research on the development of 3DCP equipment for printing concrete structures underwater and the preliminary experiment of printing concrete structures using high viscosity low-flow concrete composite materials is explained.

In this study, graphene was rapidly grown by chemical vapor deposition using a liquid cell for supplying methanol as a carbon source of graphene. To realize the rapid growth, methanol which is carbon-contained organic solvent was used instead of methane gas, a widely used carbon source for graphene growth. The graphene grown with the growth time as a variable was transferred to a SiO2/ Si substrate with an oxide thickness of 300 nm to confirm whether it was grown with full coverage with an optical microscope. The results confirmed a full coverage in 0.5 min of growth. The Raman spectra also confirmed the G-peak position at 1585.0 cm−1 and an intensity ratio of 2D/G at 2.3 or higher. Concerning electrical transport characteristics, at an induced carrier density of 1 × 1012 cm−2, the hole (μh) and electron (μe) mobilities were 1524 cm2 V−1 s−1 and 1528 cm2 V−1 s−1, respectively. Thus, our study confirmed that high-quality, large-area graphene can be grown within 0.5 min.

한-아프리카 농식품 기술협력 협의체 (KAFACI)는 아프리카 농업 공통현안을 연구과제를 통하여 해결하고자 2010년에 출범하여 현재 한국 포함 20개국으로 구성되었다. 본 논문은 지난 10년간 회원국에서 수행한 결과를 바탕으로 KAFACI 회원 국과 비회원국 간의 양자 무역 흐름에 대한 국제 기술 협력의 영향을 분석하였다. 분석은 UN 상품 무역 통계 데이터베이스에서 2000년에서 2018년 동안 45 개 아프리카 국가 간의 양 자 무역 패널 데이터를 이용하였으며 국제 무역 중력 모델을 적용하였다. 또한, 내생성, 표본 선택 편의, 패널내의 상관관계 를 통제하는 표본 선택 기법을 적용한 핵크만 랜덤 효과 회귀 모형을 사용하였다. 분석결과 경험적 결과는 국제 기술 협력이 KAFACI 회원국과 비회원 국 간의 양자 무역 흐름에 긍정적인 영향을 미친다는 것을 보여준다. 이러한 연구 결과 이 외에도 KAFACI는 회원국과 아프리카 이외의 주요 무역 파트 너 간의 양자 무역 흐름을 크게 늘렸을 가능성이 있지만 여기서는 다루지 않았다. 또한 KAFACI 회원국의 기술 채택 수준과 비율은 무역을 잠금 해제하기 위해 경제의 공급 측면에 영향을 미치는데 중요하지만 여기에서는 다루지 않았다.

The content of harmful materials was investigated for coffee beans sold in Daejeon. Total 79 samples were analysed and 213 residual pesticides and 2 heavy metals were analysed simultaneously by GC-MS/MS, GC-NPD, GC-ECD, LC-MS/MS and ICP-MS. The instrumental method was validated with limit of detection (LOD), limit of quantification (LOQ), the linearity of standard curves. LOD of the residual pesticides was between 0.0003 to 0.0021 mg/kg, LOQ of the residual pesticides was between 0.0008 to 0.0064 mg/kg. LOD of the heavy metals was between 0.0077 to 0.0079 μg/kg, LOQ of the heavy metals was between 0.0233 to 0.0239 μg/kg. The linearity correlation coefficient for the calibration curve was between 0.9929 to 0.9999 and the recovery rate was between 95.4% to 106.1%. According to the monitoring of residual pesticides and heavy metals, no pesticide was detected in all coffee bean samples. 88.6% (70 samples) of analysed total 79 coffee beans contained at least 1 heavy metal but there was no sample which exceeded the maximum residual limit. Risk assessment was also carried out based on the content of heavy metals detected in coffee beans. The carcinogenic risk assessment to heavy metals showed that all cancer-risk (CR) values were below 10–6 and it meant that the CR due to heavy metals intake was evaluated as safe. The non-carcinogenic risk assessment to heavy metals showed that all hazard index (HI) were below 1, which was considered acceptable at the current level of exposure. The %PTWI values of lead and cadmium for 55 roasted coffee bean samples were 0.09% and 0.04% respectively, compared with the reference values. This results indicate that there is almost no health risk from heavy metal intake through the consumption of coffee beans in circulation in Daejeon.

Rabies is a zoonotic disease that is caused by rabies virus and transmitted only in mammals. Domestic dogs are the most common reservoir of the virus, which is associated with more than 99% human deaths caused by dog-mediated rabies in the world. Rabies is one of the most fatal diseases, but it is fully preventable in animals by vaccination. Serological test of rabies virus antibody for samples collected from dogs and cats in Seoul during 2017–2019 was carried out in this study. To investigate antibody seroprevalence of rabies virus for dogs and cats, 2,769 serum samples were taken from 2,408 dogs and 361 cats in various regions of Seoul during 2017– 2019. Antibodies to rabies virus were detected by an indirect ELISA. Of 2,769 tested animal sera, 934 (33.7%) were positive; 886 (36.8%) of 2408 dogs and 48 (13.3%) of 361 cats. Of 990 companion animals, 547 (55.3%) was positive and 387 (21.8%) of 1779 stray animals was positive. These results indicate that antibody seroprevalence to rabies virus is still not enough to prevent rabies and rabies vaccination is required to enhance the antibody seroprevalence for rabies. To improve the situation, much public awareness and policy is needed to prevent the rabies. In addition, reducing stray animals and keeping companion animals from contact with wild animals are indispensable for the prevention of rabies.