• Biomolecules & Therapeutics
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• v.31 no.3
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• pp.253-263
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• 2023

The biogenesis and biological roles of extracellular vesicles (EVs) in the progression of liver diseases have attracted considerable attention in recent years. EVs are membrane-bound nanosized vesicles found in different types of body fluids and contain various bioactive materials, including proteins, lipids, nucleic acids, and mitochondrial DNA. Based on their origin and biogenesis, EVs can be classified as apoptotic bodies, microvesicles, and exosomes. Among these, exosomes are the smallest EVs (30-150 nm in diameter), which play a significant role in cell-to-cell communication and epigenetic regulation. Moreover, exosomal content analysis can reveal the functional state of the parental cell. Therefore, exosomes can be applied to various purposes, including disease diagnosis and treatment, drug delivery, cell-free vaccines, and regenerative medicine. However, exosome-related research faces two major limitations: isolation of exosomes with high yield and purity and distinction of exosomes from other EVs (especially microvesicles). No standardized exosome isolation method has been established to date; however, various exosome isolation strategies have been proposed to investigate their biological roles. Exosome-mediated intercellular communications are known to be involved in alcoholic liver disease and nonalcoholic fatty liver disease development. Damaged hepatocytes or nonparenchymal cells release large numbers of exosomes that promote the progression of inflammation and fibrogenesis through interactions with neighboring cells. Exosomes are expected to provide insight on the progression of liver disease. Here, we review the biogenesis of exosomes, exosome isolation techniques, and biological roles of exosomes in alcoholic liver disease and nonalcoholic fatty liver disease.

• Archives of Plastic Surgery
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• v.49 no.6
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• pp.729-739
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• 2022

Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm², and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology (p = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.

• Journal of Korea Trade
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• v.26 no.4
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• pp.83-97
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• 2022

Purpose - In this paper, we, taking South Korea's foreign direct investment in RCEP partners as an example, will examine its investment efficiency in these countries and analyze the main influencing factors, making suggestions for further liberalizing and facilitating its investment in and even for promoting its trade and economic cooperation with them. Design/methodology - In this study, we look at the panel data of South Korea and the other 13 RCEP countries (Brunei excluded) from 2000 to 2019 and apply the stochastic frontier analysis to measure its foreign direct investment efficiency and explore the influencing factors in RCEP countries. We examine the investment potential of South Korea in these places. Findings - We find that South Korea's average investment efficiency in RCEP countries reached 0.62, indicating large investment potential. We also find that its investment efficiency in RCEP partners was heterogeneous. Our study reveals that South Korea's foreign direct investment is significantly positively correlated with the market size and population of the two countries, as well as with whether the host country has a coastline and rich natural resources, while negatively with geographic distance. It shows that free trade agreements, economic freedom, and regulatory quality play significant roles in improving investment efficiency. Originality/value - Through theoretical and empirical analysis, we deal with the efficiency and influencing factors of South Korea's direct investment in RCEP partners, proposing new drivers for facilitating its trade and investment in these countries and comprehensively evaluating the efficiency and revealing the trend of its FDI in these countries. In this paper, we put forward a solid theoretical basis for empirical analysis of the future economic and trade development between South Korea and its RCEP partners and give objective insights for further improving its foreign direct investment efficiency and tapping its investment potential.

• Korea Trade Review
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• v.41 no.1
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• pp.159-186
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• 2016

This study analyzes the degree of dependency and comparative advantage of each country for intermediate goods trade in East Asia, which predicts the comparative advantage of the intermediate goods trade and fragmentation in East Asia when the FTA arrangement in East Asia is implemented. The results are as follows. First, the share of intra-regional trade in the intermediate goods in East Asia has increased over time, implying the deepening of interdependency in intermediate goods trade within the East Asia. Second, Korea is a net exporter in intermediate goods trade for China and ASEAN, whereas it is a net importer for Japan. Japan is a high net exporter for all East Asia, while China is a net importer for Korea, Japan and ASEAN. If FTA arrangement in East Asia is implemented, Japan and Korea will be key suppliers of the intermediate goods for East Asia, while China and ASEAN will play a role of the manufacturing factory through the import of intermediate goods. Third, Korea has a comparative advantage in intermediate trade of electric and electronics and transport vehicle industry in East Asia. Japan has a comparative advantage in all of electric and electronics, transport vehicle, precision instrument, general machinery industry, whereas China has a comparative advantage only in electric and electronics intermediate trade in East Asia. The intra-industry trade of the intermediate goods in precision instrument, general machinery industry is expected to grow among Korea, Japan and China.

• Design Convergence Study
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• v.17 no.3
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• pp.1-19
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• 2018

Hand rehabilitation training tools are used in hospitals and at home for patients and users who require recovery of disabled hands and improvement in overall hand function. However, existing training tools are not organized into a progressive system, and they lead to repeatability operations over a period of time. As a result, patients feel free and cannot be motivated by rehabilitation, and continuous rehabilitation training is difficult. Based on this argument, the study combines one of the elements of the game called the "Cat's cradle" to enable the user to feel achievement through play and to achieve natural rehabilitation through unconsciousness. After examining the characteristics of the tool, the user's environment, the relevance of the Cat's cradle game to the training tool and to the patient's continued rehabilitation was established. And design elements were derived through professional interviews. Later, design guidelines and prototypes have been created to complement the problems associated with guidelines and prototypes by conducting usability testing and design element assessment.

• Analyses & Alternatives
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• v.1 no.1
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• pp.44-64
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• 2017

Russia's push in the Asia-Pacific region stems from its interests that have the national, regional and global dimensions. In their turn, the aims of this policy are civilizational, geopolitical, economic and prospective, with a long-term outlook. In the course of their achievement, cooperation with Northeast Asia's countries will play one of the key roles owing to the factors of geographic proximity, Northeast Asia's economic potential, risk hedging and a growing influence Northeast Asia exerts upon the global development. A new cooperation paradigm between Russia and the states of Northeast Asia should be based upon establishing and cementing self-reproducing ties. This is the central aim of Russian initiatives in relations, with Japan, the Republic of Korea, Democratic People's Republic of Korea, Mongolia and China. However, numerous obstacles ranging from Russia's absence in the regional free trade agreements and supply-production chains of value-added production to the permanent international instability generated by Pyongyang's missile-nuclear developments hamper the practical implementation of this task. Realizing the necessity to give an additional impetus to this new cooperative paradigm, Russia has to develop directions with an apparent consolidating effect. The most promising may be the establishment of a permanent security forum based upon Northeast Asia Peace and Security Mechanism chaired by the Russian Federation. The urgency of this measure and its expected support stem from the necessity to strengthen security in Northeast Asia, a task neither the US-led hub-and-spoke system nor ASE-AN-led multilateral dialogue venues have been able to resolve. The issues addressed at the security forum must include the unification of approaches to North Korean nuclear issue and producing a document specifying actions of the claimants on the disputed maritime territories in the "direct contact" situations. At the expert level, Russia has elaborated on the idea to establish such a forum outlining the spectrum of the key directions of cooperation. With the urgency in the establishment of this dialogue venue, its agenda has to be coordinated with the agendas of the existing security systems presented by the US alliances and the ASE-AN-led multilateral negotiations. The practical implementation of this initiative will strengthen security in Northeast Asia as its challenges will be resolved in the pre-emptive way based on coordinated approaches. Therefore, Russia as the Eurasian state will be one of the role players in the advent of the Asian century.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.118-133
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• 2023

Background: Free-living amoebae (FLA) are widely distributed in freshwater, seawater, soil, and extreme environments, and play a critical role as feeders on diverse preys in the ecosystem. Also, some FLA can become opportunistic pathogens in animals including humans. The taxa Amoebozoa and Heterolobosea are important amoeboid groups associated with human pathogens. However, the identification and habitat of amoebae belonging to Amoebozoa and Heterolobosea remain poorly reported in the Republic of Korea. This study highlights the first record for identification and source of four amoebae including putative pathogens in the Republic of Korea. Results: In the present study, four previously reported FLA were isolated from freshwaters in Sangju Gonggeomji Reservoir (strain GO001), one of the largest reservoirs during the Joseon Dynasty period, and along the Nakdong River, the largest river in the Republic of Korea (strains NR5-2, NR12-1, and NR14-1) for the first time. Microscopic observations and 18S rDNA phylogenetic trees revealed the four isolated strains to be Acanthamoeba polyphaga (strains NR5-2 and NR12-1), Tetramitus waccamawensis (strain GO001), and Naegleria australiensis (strain NR14-1). Strains NR5-2 and NR12-1 might be the same species and belonged to the morphological Group 2 and the T4 genotype of Acanthamoeba. Strain GO001 formed a clade with T. waccamawensis in 18S rDNA phylogeny, and showed morphological characteristics similar to previously recorded strains, although the species' flagellate form was not observed. Strain NR14-1 had the typical morphology of Naegleria and formed a strongly supported clade with previously recorded strains of N. australiensis in phylogenetic analysis of 18S rDNA sequences. Conclusions: On the bases of morphological and molecular analyses, four strains of FLA were newly observed and classified in the Republic of Korea. Three strains belonging to the two species (A. polyphaga and N. australiensis) isolated from the Nakdong River have the potential to act as opportunistic pathogens that can cause fatal diseases (i.e. granulomatous amoebic encephalitis, Acanthamoeba Keratitis, and meningoencephalitis) in animals including humans. The Nakdong River in the Republic of Korea may provide a habitat for potentially pathogenic amoebae, but additional research is required to confirm the true pathogenicity of these FLA now known in the Republic of Korea.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.381-387
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• 2023

Background: Frailty is defined as a condition of being weak and delicate, and it represents a state of high vulnerability to adverse health outcomes. Recent studies have suggested that the cingulate gyrus is associated with frailty in the elderly population. However, few imaging studies have explored the relationship between frailty and the cingulate gyrus in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Methods: Eighteen right-handed patients with ESRD undergoing hemodialysis were enrolled in the study. We used the FreeSurfer software package to estimate the cortical thickness of the regions of interest, including the rostral anterior, caudal anterior, isthmus, and posterior cingulate gyri. The Beck Depression Inventory, Beck Anxiety Inventory, and laboratory tests were also conducted. Results: The cortical thickness of the right rostral anterior cingulate gyrus (ACG) was significantly correlated with the Fried frailty index, age, and creatinine level. Multiple regression analysis indicated that the cortical thickness of the right rostral ACG was associated with frailty after controlling for age and creatinine level. Conclusion: Our results indicate that the cortical thickness of the rostral ACG may be associated with frailty in patients with ESRD on hemodialysis and that the rostral ACG may play a role in the frailty mechanism of this population.

• Animal Bioscience
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• v.37 no.4_spc
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• pp.775-785
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• 2024

Pork production is a significant agricultural enterprise in the United States and Canada. The United States is the third-largest global producer of pork and Canada ranks seventh in pork production. The North American Free Trade Agreement and its successor, the U.S.-Mexico-Canada Agreement, have facilitated trade and integration between the two countries. The majority of production systems are modern and intensive, characterized by large vertically integrated farms using advanced technologies. Both nations benefit from their status as major producers of feed grains, with the United States leading in corn and soybeans, while Canada excels in canola and barley production. The regulatory frameworks for food safety, animal welfare, and environmental stewardship differ slightly, with the FDA and USDA overseeing these aspects in the United States, and Health Canada and the Canada Food Inspection Agency in Canada. The United States and Canada also have well-established distribution networks for pork products, relying on both domestic and international markets. Export markets play a crucial role, with the United States being a major importer of Canadian pigs, and both countries exploring opportunities in Asia. Despite a rise in global demand, domestic pork consumption trends differ, with per capita consumption remaining stable in the USA and declining in Canada. Changing consumer preferences, including a demand for ethically raised and locally sourced pork, may influence production practices. Future trends in pig production include a focus on consumer concerns, sustainability, disease prevention, reduction of antimicrobial use, and advancements in technology. The industry is adapting to challenges such as disease outbreaks and changing regulations, with a strong emphasis on animal welfare. Labor and workforce considerations, along with advancements in technology and automation, are expected to shape the efficiency of pork production in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.1-7
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• 2005

The levels of polyamines were measured to investigate the alternative nitrogen metabolism during maturation and sprouting in rice. The rice plants (cv. Ansanbyeo) were cultivated in 20-year-old non-fertilized field. The flag leaves and spikes were collected weekly after the earing stage and the seeds were harvested daily after lodging. Free, bound, and conjugated polyamines were analyzed using reverse phase HPLC. Putrescine, spermidine, spermine, agmatine and tyramine were the major amines found in rice. The level of stress-induced amine, putrescine increased during the preharvest sprouting confirming that the process was a stress to the plants. With all other polyamines, tyramine in free form decreased in flag leaves and panicles during seed maturation. However, agmatine in bound form showed a noticeable increase about 8-fold during 6 weeks period of maturation after which it declined to the bottom level. Among the individual amines, tyramine and spermine in conjugated form showed a marked change during matutation and sprouting. Interestingly, the level of tyramine with all conjugated polyamine decreased in spikes during seed maturation and increased during preharvest sprouting implying that tyrosine decarboxyation and conjugation to phenolic acids may play a key role in preharvest sprouting. Spermine in conjugated form was synthesized only at the early earing stage in the level of $3.4mole\;g^{-1}$ fresh weight, and then decreased to the level of nmole during maturation. Thereafter, it dramatically increased to 2.8 mole during preharvest sprouting. In this study we found the tyramine is a major amine in rice, and it would play a critical role in N-assimilation during seed maturation and sprouting.