• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.137-145
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• 2021

Among the non-precious metal catalysts, iron-nitrogen doped carbon (Fe-N/C) catalysts have been recognized as the most promising candidates for an alternative to Pt-based catalysts for the oxygen reduction reaction (ORR) under alkaline and acidic conditions. In this study, the nano replication method using mesoporous silica, which features tunable primary particle sizes and shape, is employed to prepare the mesoporous Fe-N/C catalysts with different shapes. Platelet SBA-15, irregular KIT-6, and spherical silica particle (SSP) were selected as a template to generate three different kinds of shapes of the mesoporous Fe-N/C catalyst. Physicochemical properties of mesoporous Fe-N/C catalysts are characterized by using small-angle X-ray diffraction, nitrogen adsorption-desorption isotherms, and scanning electron microscopy images. According to the electrochemical evaluation, there is no morphological preference of mesoporous Fe-N/C catalysts toward the ORR activity with half-cell configuration under alkaline electrolyte. By implementing X-ray photoelectron spectroscopy analysis of Fe and N atoms in the mesoporous Fe-N/C catalysts, it is possible to verify that the activity towards ORR highly depends on the portions of "Fe-N" species in the catalysts regardless of the shape of catalysts. It was suggested that active site distribution in the Fe-N/C is one important factor towards ORR activity.

• 전자통신동향분석
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• 제36권1호
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• pp.54-63
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• 2021

Since the recent COVID-19 pandemic, countries have been strengthening trade protection for their security, and the importance of securing strategic materials, such as food, is drawing attention. In addition to the cultural aspects, the global preference for food produced in Korea is increasing because of the Korean Wave. Thus, the Korean food industry can be developed into a high-value-added export food industry. Currently, Korea has a low self-sufficiency rate for foodstuffs apart from rice. Korea also suffers from problems arising from population decline, aging, rapid climate change, and various animal and plant diseases. It is necessary to develop technologies that can overcome the production structures highly dependent on the outside world of food and foster them into export-type system industries. The global agricultural industry-related technologies are actively being modified via data accumulation, e.g., environmental data, production information, and distribution and consumption information in climate and production facilities, and by actively expanding the introduction of the latest information and communication technologies such as big data and artificial intelligence. However, long-term research and investment should precede the field of living organisms. Compared to other industries, it is necessary to overcome poor production and labor environment investment efficiency in the food industry with respect to the production cost, equipment postmanagement, development tailored to the eye level of field workers, and service models suitable for production facilities of various sizes. This paper discusses the flow of domestic and international technologies that form the core issues of the site centered on the 4th Industrial Revolution in the field of agriculture, livestock, and fisheries. It also explains the environmental awareness production technologies centered on sustainable intelligence platforms that link climate change responses, optimization of energy costs, and mass production for unmanned production, distribution, and consumption using the unstructured data obtained based on detection and growth measurement data.

• Journal of the Korean Wood Science and Technology
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• 제50권6호
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• pp.458-474
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• 2022

Many methods have been explored to increase the palatability of pine (Pinus merkusii), the most common wood used for termite baiting. However, because of the undersupply of pine in Indonesia, it is crucial to vary the wood species for termite baiting and look for potential alternatives. Furthermore, various studies have shown that baiting time influences the intensity and pattern of termite attacks. Therefore, the present research aimed to study the preferences of subterranean termites and find the ideal baiting time among community wood species from Bogor, West Java, as a baiting alternative to pine. The woods tested were Acacia mangium (acacia), Falcataria moluccana (sengon), Anthocephalus cadamba (jabon), Maesopsis eminii (manii), Swietenia mahagoni (mahogany), Hevea brasiliensis (rubberwood), and P. merkusii (pine). Field tests were carried out based on the American Society for Testing and Materials D 1758-06 at the Arboretum, Faculty of Forestry and Environment, IPB University, with a baiting time of one to six months. The results led to the identification of four species of termites, namely Microtermes sp., Macrotermes sp., Shedorhinotermes sp., and Capritermes sp.. The frequency of termite attacks on the test site reached 93.1%. Rubberwood was the most potential wood bait for subterranean termites, indicated by the highest average weight loss value (65.8%) with a shorter optimal baiting time (up to one month) than that of other tested woods.

• Journal of Microbiology and Biotechnology
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• 제33권3호
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• pp.387-397
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• 2023

Cytochrome P450 (CYP) is a heme-containing enzyme that catalyzes hydroxylation reactions with various substrate molecules. Steroid hydroxylases are particularly useful for effectively introducing hydroxyl groups into a wide range of steroids in the pharmaceutical industry. This study reports a newly identified CYP steroid hydroxylase (BaCYP106A6) from the bacterium Bacillus sp. and characterizes it using an in vitro enzyme assay and structural investigation. Bioconversion assays indicated that BaCYP106A1 catalyzes the hydroxylation of progesterone and androstenedione, whereas no or low conversion was observed with 11β-hydroxysteroids such as cortisol, corticosterone, dexamethasone, and prednisolone. In addition, the crystal structure of BaCYP106A6 was determined at a resolution of 2.8 Å to investigate the configuration of the substrate-binding site and understand substrate preference. This structural characterization and comparison with other bacterial steroid hydroxylase CYPs allowed us to identify a unique Arg295 residue that may serve as the key residue for substrate specificity and regioselectivity in BaCYP106A6. This observation provides valuable background for further protein engineering to design commercially useful CYP steroid hydroxylases with different substrate specificities.

• 한국식생활문화학회지
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• 제21권6호
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• pp.702-713
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• 2006

The purpose of this study was to identify the influence of school foodservice dietitians' work value on job satisfaction, organizational commitment, and turnover intentions. Also, this study explored the role of the expectation to the institution of nutrition teachers as a moderating variable in three relationships: 1) between work value and job satisfaction, 2) between work value and organizational commitment, and 3) between work value and turnover intentions. This study surveyed dietitians who worked at school foodservice in Kyunggii and Daegu${\cdot}$Gyeoungbuk province. A total of 509 responses were collected using on-site survey and online survey (response rate 59.3%). This study conducted hierarchical regression analysis to test the moderating effect of the expectation to the institution of nutrition teachers. Results of hierarchical regression showed that work value of status upgrade had a positive effect on job satisfaction to promotion opportunity and salary, and such effect was more significantly apparent in high expectation to new work. In addition, work value of status upgrade had a positive effect on turnover intention, and such effect was more significantly apparent in low expectation to new work environment improvement. Work value of work activity preference also appeared to have a positive effect on organizational commitment, and such effect was more significantly apparent in high expectation to social status and professionalism.

• 대한토목학회논문집
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• 제29권1D호
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• pp.91-100
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• 2009

본 연구는 옥외공간 설계변화에 대해 거주민들은 옥외공간에 대해서 어떤 인식을 가지고 있는지 조사하고자 옥외공간을 녹지공간, 놀이 및 운동 관련 공간, 보행공간, 휴식 및 조경시설 공간으로 분류하고 이에 대해 각각의 만족도와 개선사항을 단지규모별로 분석하였다. 분석결과에 따르면 단지내 특색있는 공간이 어딘지에 대한 질문에 단지의 규모가 클수록 녹지공간과 운동 및 놀이공간, 휴식 및 조경시설공간이 비슷한 비율로 응답된 반면, 모든 단지의 응답자들은 단지내 가장 부족한 공간으로 운동 및 놀이공간을 생각하고 있는 것으로 나타났다. 단지규모에 따른 아파트 단지의 옥외공간에 대한 세부공간별 평가결과를 살펴보면 대단지일수록 옥외공간 설계시 좀 더 많은 설계 항목이 도입되고 운동 및 놀이공간 및 휴게공간 등에 대한 강조가 이루어지고 있는 현실과 달리 주민들의 평가는 이와 상반된 결과를 보이고 있는 것으로 나타났다. 이는 단지규모가 클수록 옥외공간에 대한 이용객이 증가하여 이에 대한 수요가 증가하고 다양화되는데 비해 단지설계는 이를 뒷받침하지 못하고 있음을 보여주는 결과라 할 수 있을 것이다.

• 한국간담췌외과학회지
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• 제28권2호
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• pp.214-219
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• 2024

Backgrounds/Aims: Open cholecystectomy is becoming obsolete and laparoscopic cholecystectomy has become the treatment of choice in gallstone diseases. Difficult gallbladders are encountered whenever there is a frozen calot's triangle, obliterated cystic plate, or both. Rather than converting to open procedure, there has been a growing preference for laparoscopic subtotal cholecystectomy (LSC) during difficult gallbladders. This study aimed to assess the advantages, indications, and viability of LSC in difficult gallbladders. Methods: The study included patients undergoing laparoscopic cholecystectomy in NIMS Hospital, Jaipur, from January 2021 to January 2023. Data of the patients who underwent LSC for difficult gallbladders included demographics, comorbidities, operative time, conversion to open cholecystectomy, length of hospital stay, and complications. LSC was classified into three types depending on the part of the gallbladder remnant. Results: A total of 728 patients underwent laparoscopic cholecystectomy. Among them, 41 patients (5.6%) were attempted for LSC. However, one patient was converted to an open procedure and the rest 40 underwent LSC. LSC was divided into 3 types, 4 patients underwent LSC type I, 34 patients underwent type II, and 2 patients type III. The average operating time and postoperative length of hospital stay were 86.2 minutes and 2.1 days, respectively. Two patients had surgical site infection. No patient had a bile leak and none required intensive care unit care. Conclusions: LSC is a safe and feasible option for use in difficult gallbladders.

• Clinical Nutrition Research
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• 제13권2호
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• pp.108-120
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• 2024

The study aimed to investigate the basic data to derive plans for snack provision to improve the nutritional status of older adults living in long-term care facilities (LFs) or long-term care hospitals (LHs). The 252 respondents (118 from LHs and 134 from LFs) were included in the study. The questionnaire of nationwide cross-sectional survey was developed by the authors and registered dietitians. The written questionnaire was sent to the food service managers across 800 LFs or LHs. The online survey was introduced using the online platform and network site for dietitians. More than 70% of live-in and non-live-in LFs provided snacks, which were mainly provided one to two times a day. Most institutions provided fruits one to three times a week. The main considerations when providing fruit were in the order of residents' preference, cost, and ease of consumption. The reasons for not serving fruit included cost and differences in the residents' eating and mastication abilities. Most institutions also provided dairy products at a frequency of one to three times a week. The reasons for not serving dairy products included cost and the lack of awareness of the need to provide them. To improve the quality of life and the offer benefits of fruits and dairy products to older people, efforts are needed to propose a plan to expand the provision of snacks in appropriate quantities and varieties.

• Journal of Microbiology and Biotechnology
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• 제34권9호
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• pp.1826-1835
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• 2024

Paracoccus denitrificans has been identified as a representative strain with heterotrophic nitrificationaerobic denitrification capabilities (HN-AD), and demonstrates strong denitrification proficiency. Previously, we isolated the DYTN-1 strain from activated sludge, and it has showcased remarkable nitrogen removal abilities and genetic editability, which positions P. denitrificans DYTN-1 as a promising chassis cell for synthetic biology engineering, with versatile pollutant degradation capabilities. However, the strain's low stability in plasmid conjugation transfer efficiency (PCTE) hampers gene editing efficacy, and is attributed to its restriction modification system (R-M system). To overcome this limitation, we characterized the R-M system in P. denitrificans DYTN-1 and identified a DNA endonuclease and 13 DNA methylases, with the DNA endonuclease identified as HNH endonuclease. Subsequently, we developed a plasmid artificial modification approach to enhance conjugation transfer efficiency, which resulted in a remarkable 44-fold improvement in single colony production. This was accompanied by an increase in the frequency of positive colonies from 33.3% to 100%. Simultaneously, we cloned, expressed, and characterized the speculative HNH endonuclease capable of degrading unmethylated DNA at 30℃ without specific cutting site preference. Notably, the impact of DNA methylase M9 modification on the plasmid was discovered, significantly impeding the cutting efficiency of the HNH endonuclease. This revelation unveils a novel R-M system in P. denitrificans and sheds light on protective mechanisms employed against exogenous DNA invasion. These findings pave the way for future engineering endeavors aimed at enhancing the DNA editability of P. denitrificans.

• 한국응용곤충학회지
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• 제44권1호
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• pp.21-30
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• 2005

곤충병원성선충 {Heterorhabditis sp. KCTC 0991BP (He)와 Steinernema carpocapsae KCTC 0981BP (Sc)}에 의한 치사충과 선충의 공생세균(He공생세균=Photorhabditis sp.와 Sc공생세균= Xenorhabdus nematophila)에 의한 치사충에 대한 개미의 섭식행동을 알아보기 위하여 동래베네스트골프장과 안양베네스트골프장, 가평베네스트골프장, 울산골프장에서 치사 원인에 따른 개미의 방문수, 종류 및 선호성을 조사하였다. 방문하는 개미의 수나 종류 및 개미가 물고 간 먹이의 수는 치사원인에 따라 차이가 있었으며, 골프장이나 골프장내의 장소(페어웨이와 러프)간에도 차이가 있었다. 개미의 선호성은 모든 골프장에서 He에 의한 치사충에서 가장 낮았다. 동래베네스트 골프장의 6번 홀에서는 러프에서만 고동털개미(Lasius japonicu)($76{\pm}2.9\%$)와 검정꼬마개미(Monomorium floricola)($10\%$)가 치사충을 끌고 갔다. 러프의 치사충에 개미의 방문이 있었던 비율은 $87{\pm}3.5\%$였지만 페어웨이에서는 처리 16시간 후까지 모든 치사충에 개미의 방문이 없었다. 12시간 후까지 개미가 끌고 간 치사충의 비율은 He에 의한 치사충이 $16.7\%$로 Sc에 의한 치사충의 $40.0\%$, fenitrothion에 의한 치사충의 $53.3\%$, 자연치사충의 $56.7\%$에 비하여 낮았다. 안양베네스트골프장 6번 홀 러프에서는 주름개미(Tetramorium tsushimae)($33{\pm}6.9\%$)와 극동혹개미(Pheidole fervida)($17{\pm}8.7\%$), 일본왕개미(Camponotus japonicus)($10\%$), 곰개미(Formica japonica)($7{\pm}3.5\%$), 스미스개미(Paratrechina flavipes)($3{\pm}3.5\%$), 마쓰무라밑들이개미(Crematogaster matsumurai)($3{\pm}3.5\%$)가 치사충을 방문하였다. 개미가 치사충을 끌고 감이 없었던 비율은 $23{\pm}8.7\%$였고, Sc에 의한 치사충을 끌고 간 비율은 $40.0\%$, 냉동 치사충을 끌고 간 비율은 $16.7\%$, He에 의한 치사충을 끌고 간 비율은 $3.4\%$였다. 가평베네스트골프장 벚꽃나무 코스 9번 홀의 러프에서는 치사충을 방문하는 개미의 수가 매우 낮았는데, 주름개미와 스미스개미가 각각 한곳에서 발견되었다. 곤충병원성 선충의 접종 농도는 개미가 끌고 간 치사충의 비율에서 차이를 보이지 않았다. 한편, 치사충의 매장 유무는 개미의 섭식활동에 영향을 미쳤다. 동래베네스트골프장 6번 홀의 러프에서 토양 속에 묻은 치사충에서는 처리 16시간 동안 개미의 방문이 없었던 반면, 묻지 않은 치사충은 끌고 갔다. He와 Sc의 공생세균을 처리한 비스켓에 대한 개미의 방문은 선충의 치사충에 대한 방문과 동일한 경향을 보여, He의 공생세균인 Photorhabditis sp.처리에서 Sc 공생세균인 Xenorhabdus 처리보다 방문수가 적었다.