This study explored effects of a sludge-based biochar addition on nitrogen removal of membrane bioreactor (MBR) for wastewater treatment. The membrane fouling reduction by the biochar addition was also investigated. A dose of 3 g/L of the biochar was applied to an MBR (i.e., BC-MBR) and treatment efficiencies of organic matter and nutrient were analyzed. The MBRs with powdered activated carbon (i.e., AC-MBR) and without any additives were also operated in parallel. The average removals of COD and TN were improved with the biochar addition compared to those with the control MBR. Interestingly, operational duration was also increased with biochar addition. The CLSM analysis revealed that biomass amounts of BC-MBR and AC-MBR were reduced by more than 40%, and thickness of the biofilm attached to the membrane surface also was decreased. The physical properties of biochar surfaces were compared with a commercial powdered activated carbon. The specific surface area with 38 m2/g and pore volume with 0.13 cm3/g of the biochar were much smaller than those of the powdered activated carbon, which were 1100 m2/g and 0.67 cm3/g, respectively. Manufacturing conditions for the biochar production needs to be further investigated for enhancing physical properties for adsorption and biological improvement.

Due to the complexity of urban area, the city vehicle routing problem has been a difficult problem. The problem has involved factors such as parking availability, road conditions, and traffic congestion, all of which increase transportation costs and delivery times. To resolve this problem, one effective solution can be the use of parcel lockers located near customer sites, where products are stored for customers to pick up. When a vehicle delivers products to a designated parcel locker, customers in the vicinity must pick up their products from that locker. Recently, identifying optimal locations for these parcel lockers has become an important research issue. This paper addresses the parcel locker location problem within the context of urban traffic congestion. By considering dynamic environmental factors, we propose a Markov decision process model to tackle the city vehicle routing problem. To ensure more real situations, we have used optimal paths for distances between two nodes. Numerical results demonstrate the viability of our model and solution strategy.

본 연구는 햄프씨드오일 (Cannabis sativa L. seed oil, CSO)와 햄프씨드오일 복합물 (Cannabis sativa L. seed oil complex, CSOC)의 비교분석을 통해 항염증 소재로서의 가능성을 평가하였다. CSO와 CSOC의 항염증 효과는 lipopolysaccharide (LPS)-induced RAW264.7 모델을 통해 확인하였다. Lipoxygenase inhibition activity를 통해 지질산화억제를 확인한 결과, CSO는 억제되지 않았지만 COSC는 70% 이상 억제되었다. MTT assay를 통해 세포독성을 확인해본 결과, CSO는 세포독성을 보이지 않았지 만 CSOC는 200 μg/ml 이상 농도에서 세포독성을 보였다. LPS로 유도된 RAW264.7에서 inducible nitric oxide synthase (iNOS)의 발현과 nitric oxide (NO)의 생산은 CSOC가 CSO보다 현저하게 억제하였다. 또한, cyclooxygenas (COX)-2의 발현과 prostraglandin E2 (PGE2)의 생성을 확인해본 결과에서도 CSOC 가 CSO보다 현저하게 억제하였다. 본 연구를 통해, CSOC가 CSO보다 우수한 항염증 효과를 가지며, 항 염증 소재로 활용 가능성이 있음을 확인했다.

본 연구에서는 머위에탄올추출물 (PJE)의 기능성 소재로서의 활용 가능성을 알아보기 위해 UVB로 유도된 Human keratinocyte (HaCaT cell)를 통해 피부장벽과 염증 개선에 대한 활성을 알아보 고자 하였다. DPPH 라디칼 소거능 측정, ABTS+ 라디칼 소거능 측정, Hydrogen peroxide 소거능 측정 을 통해 항산화 효과를 확인한 결과, 1 mg/ml 농도에서 대조군인 ascorbic acid과 비슷한 항산화 효과 를 가지고 있음을 확인하였다. UVB로 유도된 HaCaT 세포의 filaggrin과 aquaporin-3의 생성능의 mRNA의 발현을 확인해본 결과, UVB 자극에 의해 줄어든 발현량이 머위 추출물 처리 시, 농도 의존적 으로 증가하고 있음을 확인하였다. TNF-α와 IL-1β의 mRNA 발현은 UVB 자극에 의해 증가되었으 며 머위 추출물을 처리하였을 때 감소되는 것을 확인할 수 있었다. Migration assay 결과 농도 의존적 으로 피부 각질세포의 증식과 상처의 회복율을 증가시켰음을 확인하였다. 실험결과를 바탕으로 머위가 피부 보습 및 피부장벽 기능을 개선할 수 있는 기능성 소재의 화장품으로 사용될 수 있음을 시사한다.

본 연구는 간호대학생의 그릿과 사회적 지지가 대학생활적응에 미치는 영향요인을 파악하기 위한 조사연구이다. 연구 대상자는 간호대학생 196명을 대상으로 하였으며 자료수집은 2020년 7월 1일부터 8월 13일까지 수행하였다. 자료 분석은 SPSS 22.0을 이용하여 기술통계, 상관관계 분석 및 다중회귀분석을 사용하였다. 연구결과, 간호대학생의 대학생활적응은 그릿(r=.328, p<.001)과 사회적 지지(r=.334, p<.001) 와 유의한 정적 상관관계를 보였다. 학년, 그릿 및 사회적 지지는 간호대학생의 대학생활적응에 유의한 영향을 미치는 요인으로 나타났다. 이에 본 연구결과를 바탕으로 간호대학생의 대학 생활 적응을 위해서 그릿과 사회적 지지와 같은 긍정적 요인을 포함시킨 대학생활적응 프로그램 개발 및 적용을 제안한다.

Canine parvovirus (CPV) type 2a (CPV-2a) has recently been identified as the main genotype circulating in the dog population in South Korea. Although CPV vaccines protect domestic dogs from CPV-2 infection, the efficacy of commercial live or inactivated CPV vaccines against CPV-2a has not been reevaluated. In this study, dogs were immunized with one of 7 commercial CPV vaccines (4 modified live and 3 inactivated vaccines) followed by challenge with CPV-2a strain, KV0901 that had been isolated from naturally infected dog in 2009. All dogs vaccinated twice with 4 commercial modified live CPV vaccines were seroconverted (geometric mean HI titer > 190.2) and most of dogs were completely protected against virulent CPV-2a strain infection. The dogs inoculated with 3 commercial inactivated CPV vaccines were also seroconverted and showed a slight loss of appetite and light diarrhea for 4 days after challenge and returned to normal at 5 days post challenge. However, the non-vaccinated dogs revealed the typical clinical signs of CPV infection including haemorrhgic diarrhea. In conclusion, the 4 live CPV vaccines licensed in Korea cross-protected dogs against virulent challenge with CPV-2a and are applicalble to pet dogs for the prevention of CPV infection.

Porcine circovirus type 2 (PCV2) is associated with porcine circovirus diseases (PCVD), of which postweaning multisystemic wasting syndrome is considered to cause considerable economic losses in pig industry worldwide. As the virus-like particle (VLP) is a highly effective type of subunit vaccine and has unique advantages in terms of safety and immunogenicity, this study aimed to develop PCV2-like particles, which matched currently circulating Korean PCV2 and were applicable as vaccines. The ORF2 genes encoding PCV2 capsid protein were amplified from the PCV2 subgroup 1A/B Korean C275 isolate and the subgroup 2E C94 isolate by PCR assay with primer pair specific to PCV2 ORF2 gene, and were cloned into baculovirus transfer vector. Recombinant baculovirus was generated by cotransfection with the transfer vector and linear baculovirus DNA into the Sf9 cells, and then by plaque purification. Expression of PCV2 capsid protein was determined by the indirect immunofluorescence and Western blotting assays, and electron microscopy. By both immunological assays, PCV2 capsid antigen was detected in the Sf9 cells infected with the recombinant baculoviruses. The formation of empty virus particles, characteristic of VLP, was detected in the lysate of Sf9 cells infected with the recombinant baculoviruses by negative electron microscopy. From these results, VLPs of two genogroups of PCV2 were successfully expressed and generated in a baculovirus expression system. It is expected that the expressed VLPs of two genotypic groups can be used for control of PCV2 infection as good vaccine candidates.

Although several enteric viral pathogens including the porcine groups A, B and C rotaviruses (PGARV, PGBRV, and PGCRV), sapovirus (PSaV), and torovirus (PToV) are known to cause endemic diarrheas in weaning and post-weaning piglets, their precise prevalence in Korea is not clear. Therefore, we examined 1,222 diarrhea stools obtained from 627 farms during 2004～2009 by RT-PCR and/or nested PCR for evaluating their precise prevalence in Korea. PGARV was the predominant pathogen during 2004～2007 but its prevalence was markedly reduced during 2008～2009. PGBRV infections caused endemic diarrhea during 2004～2007, but was hardly detected during 2008-2009. PGCRV was detected at 27.0%, 14.5%, 42.4%, 28.8%, 7.3%, and 54.2% during each year of 2004～2009, respectively, indicating its high prevalence in Korea throughout the years. PSaV induced with high prevalence (32.4-39.2%) during 2004～2005 but its detection rate was markedly decreased during 2006～2009. PToV caused sporadic infections only during 2006 (1.0%) and 2007 (6.9%). These enteric viruses were detected in diarrhea specimens in piglets usually in combination with each other and/or together with bacterial pathogens including the Escherichia coli, Salmonella spp., Brachispira hyodysenteriae, and Lawsonia intracellularis. Infections with PGARV, PGCRV, PSaV, and PToV were more prevalent in fecal samples collected in cold seasons. These results provide important epidemiological data for the control and establishment of a surveillance system for the prevailing enteric viruses in Korea.