1,185 research outputs found
Determinants of Esports Highlight Viewership: The Case of League of Legends Champions Korea
Studies on esports league demand via new media platforms are limited yet. This paper is the first to identify determinants of esports highlight viewership. Using set-level highlight view count from YouTube, we analyze various determinants to explain view counts. As a result, we found that the number of kills, playoff games, age of video clip, 2nd round games, and 3rd set is positively correlated to view counts. Outcome uncertainty and upset results do not affect view counts. We interpret the results that as highlight clips are released after the game is finished, viewers can know the results when making a decision. Or, relatively short highlight videos reduce opportunity costs for fans and fans do not care about game outcomes much
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Session D5: Current Status of Fish Passages in South Korea
Abstract:
Weirs are important for countries that agriculture is the primary industry due to the stable supply of water to agricultural fields. Because agriculture is still important in Korean peninsula, weirs have been constructing until now from small streams to large rivers. However, only limited fish passages were installed in weirs, and there were no managements. As a results, streams and rivers have become highly fragmented, with fish migration being severely impeded. Thus, ministry of agriculture, food and rural affairs investigated entire fish passages in Korea in 2010-2011, and estimated current status and problems. A total of 33,718 weirs were installed (until year 2012), and this means that weirs are arithmetically located every 0.81km of the total stream length in Korea. Fish passages, however, were constructed only in 4,496 weirs (13.3% of installation rate). The weir type fish passages with Ice- Harbor type fishways (8.1%) which are favoured nowadays was showed the greatest number (36%), and the vertical slot type passages was in the second place (31%). The denil type and nature-like type were rarely installed. Only 18.1% of installed fish passages were left whole, and urgent repair is needed for 56.7%. Fish passages of 31.3% were incorporated into the recommended slope range of Korea (1:20). Most of problems are related discharge, poor entrance, breakage and sedimentation. With these structural problems, discontinuous installation of fish passages generates poor continuity of streams. Currently, to improve stream connectivity many projects from Korean government are now conducting and preparing, and additionally development of fish passages specialized for Korean fishes are required
Missed a live match? Determinants of League of Legends Champions Korea highlights viewership
This research aims to explore the determinants of the League of Legends Champions Korea (LCK) highlight views and comment counts. The data of 629 game highlight views and comment counts for seven tournaments were collected from YouTube. The highlight views and comment counts were regressed on a series of before-the-game factors (outcome uncertainty and game quality), after-the-game factors (sum and difference of kills, assists, multiple kills, and upset results), and match-related characteristics (game duration, evening game, and clip recentness). A multi-level least square dummy variable regression was conducted to test the model. Among the before-the-game factors, outcome uncertainty and game quality were significantly associated with highlight views and comment counts. This indicated that fans liked watching games with uncertain outcomes and those involving high-quality teams. Among the after-the-game factors, an upset result was a significant determinant of esports highlight views and comment counts. Thus, fans enjoy watching underdogs win. Finally, the sum of kills and assists only affected view counts, which indicated that fans prefer watching offensive games with more kills and a solo performance rather than teamwork
Retinoid production using metabolically engineered Escherichia coli with a two-phase culture system
<p>Abstract</p> <p>Background</p> <p>Retinoids are lipophilic isoprenoids composed of a cyclic group and a linear chain with a hydrophilic end group. These compounds include retinol, retinal, retinoic acid, retinyl esters, and various derivatives of these structures. Retinoids are used as cosmetic agents and effective pharmaceuticals for skin diseases. Retinal, an immediate precursor of retinoids, is derived by β-carotene 15,15'-mono(di)oxygenase (BCM(D)O) from β-carotene, which is synthesized from the isoprenoid building blocks isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Retinoids are chemically unstable and biologically degraded via retinoic acid. Although extensive studies have been performed on the microbial production of carotenoids, retinoid production using microbial metabolic engineering has not been reported. Here, we report retinoid production using engineered <it>Escherichia coli </it>that express exogenous BCM(D)O and the mevalonate (MVA) pathway for the building blocks synthesis in combination with a two-phase culture system using a dodecane overlay.</p> <p>Results</p> <p>Among the BCM(D)O tested in <it>E. coli</it>, the synthetic retinoid synthesis protein (SR), based on bacteriorhodopsin-related protein-like homolog (Blh) of the uncultured marine bacteria 66A03, showed the highest β-carotene cleavage activity with no residual intracellular β-carotene. By introducing the exogenous MVA pathway, 8.7 mg/L of retinal was produced, which is 4-fold higher production than that of augmenting the MEP pathway (<it>dxs </it>overexpression). There was a large gap between retinal production and β-carotene consumption using the exogenous MVA pathway; therefore, the retinal derivatives were analyzed. The derivatives, except for retinoic acid, that formed were identified, and the levels of retinal, retinol, and retinyl acetate were measured. Amounts as high as 95 mg/L retinoids were obtained from engineered <it>E. coli </it>DH5α harboring the synthetic <it>SR </it>gene and the exogenous MVA pathway in addition to <it>dxs </it>overexpression, which were cultured at 29°C for 72 hours with 2YT medium containing 2.0% (w/v) glycerol as the main carbon source. However, a significant level of intracellular degradation of the retinoids was also observed in the culture. To prevent degradation of the intracellular retinoids through <it>in situ </it>extraction from the cells, a two-phase culture system with dodecane was used. The highest level of retinoid production (136 mg/L) was obtained after 72 hours with 5 mL of dodecane overlaid on a 5 mL culture.</p> <p>Conclusions</p> <p>In this study, we successfully produced 136 mg/L retinoids, which were composed of 67 mg/L retinal, 54 mg/L retinol, and 15 mg/L retinyl acetate, using a two-phase culture system with dodecane, which produced 68-fold more retinoids than the initial level of production (2.2 mg/L). Our results demonstrate the potential use of <it>E. coli </it>as a promising microbial cell factory for retinoid production.</p
Severe steatohepatitis with hepatic decompensation resulting from malnutrition after pancreaticoduodenectomy
The most common finding related to nonalcoholic steatohepatitis is obesity, but a status of severe malnutrition can also induce the steatohepatitis. The authors report a rare case of steatohepatitis leading to hepatic decompensation caused by malnutrition after pancreaticoduodenectomy. A 68-year-old female patient who had been previously diagnosed with pancreatic cancer and had undergone pancreaticoduodenectomy 5 months previously presented with abdominal distension. Routine CT performed 3 months after the surgery revealed severe fatty liver without evidence of tumor recurrence. After undergoing pancreaticoduodenectomy her food intake had reduced, and as a result she had lost 7 kg of body weight over 2 months. At this admission, CT revealed moderate amounts of ascites without tumor recurrence. Furthermore, her albumin and lipid profile levels were markedly decreased, and she had a flapping tremor and slurred speech suggestive of hepatic encephalopathy. Her liver biopsy findings were consistent with steatohepatitis and disclosed macrovesicular steatosis without definite fibrosis. After careful nutritional control, her symptoms disappeared and her laboratory findings improved
Physicochemical, Biological, and Antibacterial Properties of Four Bioactive Calcium Silicate-Based Cements
Calcium silicate-based cement (CSC) is a pharmaceutical agent that is widely used in dentistry. This bioactive material is used for vital pulp treatment due to its excellent biocompatibility, sealing ability, and antibacterial activity. Its drawbacks include a long setting time and poor maneuverability. Hence, the clinical properties of CSC have recently been improved to decrease its setting time. Despite the widespread clinical usage of CSC, there is no research comparing recently developed CSCs. Therefore, the purpose of this study is to compare the physicochemical, biological, and antibacterial properties of four commercial CSCs: two powder–liquid mix types (RetroMTA® [RETM]; Endocem® MTA Zr [ECZR]) and two premixed types (Well-Root™ PT [WRPT]; Endocem® MTA premixed [ECPR]). Each sample was prepared using circular Teflon molds, and tests were conducted after 24 h of setting. The premixed CSCs exhibited a more uniform and less rough surface, higher flowability, and lower film thickness than the powder–liquid mix CSCs. In the pH test, all CSCs showed values between 11.5 and 12.5. In the biological test, cells exposed to ECZR at a concentration of 25% showed greater cell viability, but none of the samples showed a significant difference at low concentration (p > 0.05). Alkaline phosphatase staining revealed that cells exposed to ECZR underwent more odontoblast differentiation than the cells exposed to the other materials; however, no significant difference was observed at a concentration of 12.5% (p > 0.05). In the antibacterial test, the premixed CSCs showed better results than the powder–liquid mix CSCs, and ECPR yielded the best results, followed by WRPT. In conclusion, the premixed CSCs showed improved physical properties, and of the premixed types, ECPR exhibited the highest antibacterial properties. For biological properties, none of these materials showed significant differences at 12.5% dilution. Therefore, ECPR may be a promising material with high antibacterial activity among the four CSCs, but further investigation is needed for clinical situations
Continuous nanobelts of nickel oxide–cobalt oxide hybrid with improved capacitive charge storage properties
This paper reports the synthesis of continuous nanobelts, whose thickness is less than half of its pore diameter, of a material hybrid composing of nanograins of nickel oxide and cobalt oxide by electrospinning technique and their capacitive charge storage properties. While the constituent binary metal oxides (NiO and Co3O4) formed solid cylindrical nanofibers the hybrid and a stoichiometric compound in the Ni-Co-O system, i.e., spinel-type NiCo2O4, formed as thin nanobelts due to the magnetic interaction between nickel and cobalt ions. The nanobelts showed six-fold larger surface area, wider pores, and impressive charge storage capabilities compared to the cylindrical fibres. The hybrid nanobelts showed high specific capacitance (CS ~ 1250 F g− 1 at 10 A g− 1 in 6 M KOH) with high capacity retention, which is appreciably larger than found for the stoichiometric compound (~ 970 F g− 1 at 10 A g− 1). It is shown that the hybrid nanobelts have lower internal resistance (1.3 Ω), higher diffusion coefficient (4.6 × 10− 13 cm2 s− 1) and smaller relaxation time (0.03 s) than the benchmark materials studied here
A novel bispecific antibody dual-targeting approach for enhanced neutralization against fast-evolving SARS-CoV-2 variants
IntroductionThe emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has caused unprecedented health and socioeconomic crises, necessitating the immediate development of highly effective neutralizing antibodies. Despite recent advancements in anti-SARS-CoV-2 receptor-binding domain (RBD)-specific monoclonal antibodies (mAbs) derived from convalescent patient samples, their efficacy against emerging variants has been limited. In this study, we present a novel dual-targeting strategy using bispecific antibodies (bsAbs) that specifically recognize both the SARS-CoV-2 RBD and fusion peptide (FP), crucial domains for viral attachment to the host cell membrane and fusion in SARS-CoV-2 infection. MethodsUsing phage display technology, we rapidly isolated FP-specific mAbs from an established human recombinant antibody library, identifying K107.1 with a nanomolar affinity for SARS-CoV-2 FP. Furthermore, we generated K203.A, a new bsAb built in immunoglobulin G4-(single-chain variable fragment)2 forms and demonstrating a high manufacturing yield and nanomolar affinity to both the RBD and FP, by fusing K102.1, our previously reported RBD-specific mAb, with K107.1. ResultsOur comprehensive in vitro functional analyses revealed that the K203.A bsAb significantly outperformed the parental RBD-specific mAb in terms of neutralization efficacy against SARS-CoV-2 variants. Furthermore, intravenous monotherapy with K203.A demonstrated potent in vivo neutralizing activity without significant in vivo toxicity in a mouse model infected with a SARS-CoV-2 variant. ConclusionThese findings present a novel bsAb dual-targeting strategy, directed at SARS-CoV-2 RBD and FP, as an effective approach for rapid development and management against continuously evolving SARS-CoV-2 variants
Laboratory information management system for COVID-19 non-clinical efficacy trial data
Background : As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research.
Results : In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research.
Conclusions : This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.This research was supported by the National research foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2020M3A9I2109027 and 2021M3H9A1030260)
Graphene-Based Nanocomposites for Energy Storage
Since the first report of using micromechanical cleavage method to produce graphene sheets in 2004, graphene/graphene-based nanocomposites have attracted wide attention both for fundamental aspects as well as applications in advanced energy storage and conversion systems. In comparison to other materials, graphene-based nanostructured materials have unique 2D structure, high electronic mobility, exceptional electronic and thermal conductivities, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. Therefore, they are considered as attractive materials for hydrogen (H2) storage and high-performance electrochemical energy storage devices, such as supercapacitors, rechargeable lithium (Li)-ion batteries, Li–sulfur batteries, Li–air batteries, sodium (Na)-ion batteries, Na–air batteries, zinc (Zn)–air batteries, and vanadium redox flow batteries (VRFB), etc., as they can improve the efficiency, capacity, gravimetric energy/power densities, and cycle life of these energy storage devices. In this article, recent progress reported on the synthesis and fabrication of graphene nanocomposite materials for applications in these aforementioned various energy storage systems is reviewed. Importantly, the prospects and future challenges in both scalable manufacturing and more energy storage-related applications are discussed
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