역전기투석(reverse electrodialysis, RED)은 이온교환막을 격막으로 이용하여 해수와 담수의 농도차로부터 발전하 는 유망한 친환경 재생에너지 기술 중 하나이다. 이온교환막은 RED의 성능을 좌우하는 핵심 구성요소로 낮은 전기적 저항, 높은 이온선택투과도, 우수한 내구성 및 저렴한 제조 비용 등의 요구조건을 만족시켜야 한다. 본 연구에서는 다양한 두께 및 기공율을 갖는 다공성 고분자 지지체를 이용하여 세공충진 음이온교환막을 제조하고 이온교환 고분자의 조성과 막 두께가 RED의 발전 성능에 미치는 영향을 조사하였다. 이온교환막의 전기적 저항이 충분히 낮은 경우 RED 발전 성능은 주로 막의 apparent permselectivity에 의해 좌우됨을 확인할 수 있었다. 또한 막의 apparent permselectivity는 IEC, 가교도, 막 두께, 표면 개질 등을 통해 향상시킬 수 있으며 전기적 저항과의 trade off 관계를 고려하여 최적 조건을 찾아야 함을 확인하였다.

본 연구에서는 zeolitic imidazolate framework-9 (ZIF-9)을 합성하고 poly(ether-b-amide)-1657 (Pebax-1657) 내에 함량을 달리하여 Pebax/ZIF-9 혼합막을 제조한 다음 단일기체 (N2, CO2)를 투과하여 혼합막에 대한 기체 투과 특성을 조사하 였다. 순수 Pebax 막 내에 혼입되는 ZIF-9 함량이 증가함에 따라 N2 투과도는 점차 감소하고, CO2 투과도는 Pebax/ZIF-9 3 wt% 혼합막까지 증가하다가 그 이후의 함량에서는 감소하였다. 그리고 혼합막들 중 Pebax/ZIF-9 3 wt% 혼합막은 극성 기체 인 CO2에 대해 gate-opening 현상이 일어나면서 선택적으로 CO2를 받아들여 가장 높은 선택도 69.3을 보였다. 또한 CO2 투 과도와 CO2/N2 선택도가 모두 증가하여 Robeson upper-bound에 가장 근접하는 결과를 얻었다.

Probiotics are live microorganisms that confer health benefits onto the host when administered at adequate doses. Most widely used probiotics, such as lactobacilli and bifidobacteria, are known to be elements of healthy gut microflora and hence are not considered a threat to the host. However, probiotics may pose a risk in certain populations with compromised immune systems or defects in gut barrier functions. Herein, we evaluated the safety of Bifidobacterium breve BB077, according to the safety evaluation guidelines for probiotics produced by the National Institute of Food and Drug Safety Evaluation (NIFDS). The results show that B. breve BB077 is both non-hemolytic and non-cytolytic. In contrast, B. breve BB077 exhibited higher streptomycin and tetracycline resistance than the suggested NIFDS standard cut-off values. Hence, a genetic analysis of the streptomycin and tetracycline resistance genes was performed to determine the origin of antimicrobial resistance. Streptomycin and tetracycline resistance was shown have arisen from chromosomal mutations and considered intrinsic to the taxonomic group. In conclusion, the B. breve BB077 strain might be safe for human consumption.

본 논문은 슬로싱 상태에 놓인 포화 상태 액체수소탱크에서 열 유속 및 BOG(Boil-off gas)의 경향을 다루고 있다. 특히, 액체-기체 간의 침투 및 혼합에 의한 열 교환에 관심을 두었다. 먼저, VOF(Volume of fluid)와 Eulerian 기반의 다상 유동모델로 모형 슬로싱 실험 을 모사하여 압력을 예측하고 계측된 값과 비교하였다. 자유 수면 및 충격 압력 실험 결과와 해석 결과를 비교하였으며, 유체의 속도 예측에서 정확할 수 있음을 간접적으로 증명하였다. 그리고 2차원의 Type-C 원통형 수소탱크를 대상으로 다상열유동해석을 수행하 였다. 이때 포화상태에 놓인 액체 및 기체수소를 가정하고, 해석을 통해 각 상간의 혼합에 의한 열 교환의 수준을 확인하고자 하였다. 단, 상간의 열 교환만을 관심으로 두고 있었으므로 질량전달 및 기화모델은 해석에서 제외하였다. 최종적으로 상의 혼합으로 인해 액 체수소로 유입되는 열 유속의 기여도에 대하여 정리하였다. 또한 액체수소로 유입되는 열 유속과 집중 질량 기반의 간이식을 통해 BOG 발생량 및 경향을 예측하고 분석하였다.

췌석은 만성췌장염에서 흔히 동반되는 소견으로 반복되는 복통과 췌장염의 원인이 될 수 있다. 췌석은 췌관 협착과 자주 동반되고 췌관내 박혀 있는 경우가 많아 바스켓을 이용하여 제거하기 어렵다. 체외충격파쇄석술(ESWL)로 치료하기도 하나 반복 시술이 필요하고 성공률도 높지 않았다. 최근에 개발된 SpyGlass™ DS II (Boston Scientific, Marlborough, MA, USA)는 직경이 3.5 mm로 가늘어 췌관이 확장되어 있을 때 안으로 삽입이 가능하게 되었다. 그리고 직접 췌석을 보면서 전기수압쇄석술(EHL)이나 레이저 유도 쇄석술(laser lithotripsy)를 시행하며 췌석을 제거해 볼 수 있게 되었다. 본고에서는 SpyGlass™ DS II와 EHL을 이용하여 10 mm 이상의 다발성 췌석을 제거하는 방법을 소개하고자 한다.

Sarcoma is rare malignant tumors that develop from mesenchymal cells. Metastasis to the oral cavity is a rare occurrence. Undifferentiated Pleomorphic sarcoma(UPS), formerly known as Malignant fibrous histiocytoma(MFH), is rare spindle cell neoplasm that can have poorly prognosis with metastasis and local recurrence. This report describes a case of a 77-year-old man who was diagnosed with Undifferentiated Pleomorphic Sarcoma of the chest wall and underwent adjuvant radiation therapy after surgical resection. Although there was success of wide excision, two years later, he presented with metastasis to the several organs including tongue. We retrospectively analyzed results of Next Generation Sequencing(NGS), and we figured out RB1 gene mutation. Until now targeted therapy of RB1 gene mutation is not established. Surgeon needs to consider metastatic tumors through identifying patients’ chief complaints and past medical & dental history. We need to research through NGS, and take a step closer to find targeted therapy for tumors.

Porphyromonas gingivalis, a major pathogen of chronic periodontitis, colonizes in subgingival crevice and affects surrounding oral tissues, especially in periodontitis patients. Oral cancer mainly occurs in old-aged persons, and are exposed to the P. gingivalis, released from periodontitis, one of the most common inflammatory disease of oral cavity. Thus oral cancer cells may be infected with P. gingivalis, and its biologic behavior are autologously and/or heterogeneously modulated by altering gene expression. Exosomes which are derived from cells contain not only coding genes but also non-coding RNAs such as long non-coding RNAs, miRNA, and piRNAs. Here, to investigate the effect of P. gingivalis on oral cancer cells and to gain insight into the crosstalk between inflammatory signal from tumor microenvironment and oral cancer, we observed miRNA profiles of exosomes from P. gingivalis–infected oral cancer cells. Upregulation of 6 miRNAs, miR-203-3p, miR-6516-3p, miR-483-5p, miR-1275, miR-8485, and miR-19a-3p, were observed whereas 14 miRNAs including let-7a-3p, miR-106a-5p were downregulated. In addition, KEGG pathway analysis using the upregulated- and downregulated- miRNAs showed association with cell adhesion molecules pathway and ECM-receptor interaction pathway, respectively. These findings suggest that P. gingivalis could modulate biologic behavior of oral cancer cells through changes of exosomal miRNAs.

PURPOSES : The "Super-Bus Rapid Transit" (S-BRT) standard guidelines recommend installing physical facilities to separate bus lanes, so as to remove possible conflicts with other traffic when using an existing road as an S-BRT route. Based on a collision simulation, we reviewed the protective performance and installation method of a low-profile barrier, i.e., one that does not occupy much of the width of the road as a physical facility and does not obstruct the driver's vision. METHODS : The LS-DYNA collision analysis software was used to model the low-profile barrier, and a small car collision simulation was performed with two different installation methods and by changing the collision speeds of the vehicle. The installation methods were divided into a fixed installation method based on on-site construction and a precast method, and collision speeds of 80 and 100 km/h were applied. The weight of the crash vehicle was 1.3 tons, and the segment lengths of the low-profile barriers were 2.5 and 4.0 m, respectively. The lowprofile barriers were modeled as precast concrete blocks, and the collision simulation for a fixed concrete barrier was performed by fixing the nodes at the bottom of the low-profile barrier. The low-profile barrier comprised a square cross-section reinforced concrete structure, and the segments were connected by connecting steel pipes with varying diameters to wire ropes. RESULTS : From comparing and analyzing the small car collision simulations for the changes in collision speeds and installation methods of the low-profile barrier, a significant difference was found in the theoretical head impact velocity (THIV) and acceleration severity index(ASI) for the 2.5-m barrier at a collision speed of 80 km/h. However, the differences in the installation method were not significant for the 4.0-m barrier. The occupant safety index with a collision speed of 80 km/h was calculated to be below the limit regardless of the installation method, and the length of the segment satisfied the occupant protection performance. At a collision speed of 100 km/h, when the segment length of the 2.5-m barrier was fixed, the THIV value exceeded the limit value; thus, the occupant protection performance was not satisfied, and the occupant safety index differed depending on the installation method. The maximum rotation angle of the vehicle, which reflects the behavior of the vehicle after the collision, also varied depending on the installation method, and was generally small in the case of precast concrete. CONCLUSIONS : Low-profile barriers can be installed using a fixed or precast method, but as a result of the simulation, the precast movable barrier shows better results in terms of passenger safety. Therefore, it would be advantageous to secure protection performance by installing a low-profile barrier with the precast method for increased safety in high-speed vehicle collisions.

PURPOSES : Currently, the domestic construction industry is dominated by large-scale projects such as roads, ports, airports, and buildings. Construction on such projects is generally conducted simultaneously, but the process and quality management are led by a small number of responsible managers. In the case of road pavements, owing to rapid industrial development, economic growth, and the expansion of social overhead capital investment in the road construction industry, highways and general national roads have been constructed on a large scale. Therefore, this study aimed to improve and develop domestic concrete production and construction quality management by improving the reliability and transparency of production quality management and simplifying business processes. This was accomplished through the development of an Internet of Things (IoT)-based cement quality management system capable of automated design and build (D/B) construction and real-time monitoring. METHODS : The "IQ" system is a quality management system for enabling real-time monitoring of D/B quality at the time of concrete production and according to the designated age by utilizing quality test equipment developed with an LTE-Bluetooth function. It is possible to immediately identify and respond to quality problems through real-time monitoring, secure a reliable quality D/B because the quality test results cannot be arbitrarily manipulated, and to simplify the work process through the automatic D/B construction. In addition, improved quality control can be achieved through real-time information sharing and feedback system operations between contractors, managers, and personnel involved in construction. The quality control test items for developing the IQ system are the compression and flexural strengths, as these can be used to determine the design standard strength of pre-curing concretes (such as their slump and unit quantity) and the adequacy of the workability and durability, as well as the air volume to predict the durability, and the chloride content in the sections where reinforcement is used. CONCLUSIONS : This study identified difficulties and limitations in quality management according to the operation method in the domestic quality management systems, and in the real-time monitoring between managers and contractors. Thus, it was necessary to establish an improved systematic and reliable quality management system. The IQ system was developed to solve this problem.

PURPOSES : The increasing heat wave warnings during the summer season in Korea have significant impacts on daily life and industry as a whole, especially in urban areas (such as areas with asphalt and sidewalk pavements). Heat waves directly affect urban heat island and heat dome phenomena. Various urban temperature reduction measures are being discussed to reduce urban heat islands and heat dome phenomena and to improve citizen safety against summer heat waves; suggestions include thermal packaging, rooftop greening, and expansion of vegetation areas. There is a lack of analysis on the methodology for increasing the road spraying effect during summer heat waves (e.g., there is no systematic engineering study on the effect from reducing the temperature of the road spraying during a heat wave in the city) and on the types of road pavements in the city. In addition, as the asphalt pavements of roadways and block pavements installed in sidewalks account for a considerable portion of all pavements, this study provides a more systematic and scientific approach and procedures for reducing temperatures through road spraying in the city by tracking the effects of heat waves. METHODS : In this preliminary experiment, four types of road pavement materials were selected as test specimens: asphalt test specimens (AP- 300 mm × 300 mm × 50 mm), concrete test specimens (CP-300 mm × 300 mm × 50 mm), impermeable blocks (IB-200 mm × 200 mm × 60 mm), and self-permeable blocks (PB-200 mm × 200 mm × 60 mm). As a test method to evaluate the size and duration of each spray effect package type, the surface temperature of each specimen was measured using thermal imaging cameras every 20 min after spraying at the maximum temperature point of each specimen, and the average surface temperature was analyzed based on the collected temperature data. In addition, to conduct a quantitative analysis of the effect of reducing the surface temperature of road pavements by road spraying in summer, field tests were conducted on asphalt roads and watertight blocks for sidewalks. RESULTS : As a result of the comparative analysis of the spray effect under a 36 ℃ air temperature based on a heat wave warning, the surface temperatures were, from high to low, the asphalt (68.8 ℃), concrete (59.1 ℃), impermeable block (57.3 ℃), and permeable block (58.7 ℃). The asphalt pavement had the greatest effect on the heat island and heat dome phenomena. From measuring the temperature reduction effect and sustainability of each type of road pavement, the surface temperature reduction effects were ranked in the following order: water-permeable block (Δ18.0 ℃), asphalt test piece (Δ17.5 ℃), concrete test piece (Δ12.2 ℃), and water-permeable block (over 240 min). In the report pitching block, the average road surface temperature reduction between the pore recovery and treatment was expected to continue to decrease by approximately -4.3 ℃ on the day of work and approximately -2.4 ℃ on the next day. The expected effect of the temperature reduction owing to simple spraying on the surface of the pore block was evaluated to be limited to the day. CONCLUSIONS : In the road spray effect analysis conducted on the common asphalt road, there was a slight difference in the initial temperature reduction size as the test specimen was measured, but the surface temperature difference between the non-spray section and spray section tended to be approximately Δ3°C after 140 minutes of spraying. Therefore, it was determined that the asphalt pavement temperature reduction plan through road spraying in urban areas in summer would be the most effective if it was repeated twice or more in an hour (between 13:00 and 14:00) on the day of the heat wave.

The recycling of solid waste materials to fabricate carbon-based electrode materials is of great interest for low-cost green supercapacitors. In this study, porous carbon foam (PCF) was prepared from waste floral foam (WFF) as an electrode material for supercapacitors. WFF was directly carbonized at various temperatures of 600, 800, and 1,000 oC under an inert atmosphere. The WFF-derived PCF (C-WFF) was found to have a specific surface area of 458.99 m2/g with multi-modal pore structures. The supercapacitive behavior of the prepared C-WFF was evaluated using a three-electrode system in a 6 M KOH aqueous electrolyte. As a result, the prepared C-WFF as an active material showed a high specific capacitance of 206 F/g at 1 A/g, a rate capability of 36.4 % at 20 A/g, a specific power density of 2,500 W/kg at an energy density of 2.68 Wh/kg, and a cycle stability of 99.96 % at 20 A/g after 10,000 cycles. These results indicate that the C-WFF prepared from WFF could be a promising candidate as an electrode material for high-performance green supercapacitors.