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Organ-on-a-chip (OOAC) has attracted great attention during the last decade as a revolutionary alternative to conventional animal models. This cutting-edge technology has also brought constructive changes to the field of cardiovascular research. The cardiovascular system, especially the heart as a well-protected vital organ, is virtually impossible to replicate in vitro with conventional approaches. This made scientists assume that they needed to use animal models for cardiovascular research. However, the frequent failure of animal models to correctly reflect the native cardiovascular system necessitated a search for alternative platforms for preclinical studies. Hence, as a promising alternative to conventional animal models, OOAC technology is being actively developed and tested in a wide range of biomedical fields, including cardiovascular research. Therefore, in this review, the current literature on the use of OOACs for cardiovascular research is presented with a focus on the basis for using OOACs, and what has been specifically achieved by using OOACs is also discussed. By providing an overview of the current status of OOACs in cardiovascular research and its future perspectives, we hope that this review can help to develop better and optimized research strategies for cardiovascular diseases (CVDs) as well as identify novel applications of OOACs in the near future.

Passivation during ageing of precipitation-hardened UNS N07718 in 5 wt% NaCl + 0.5 wt% CH3COOH was investigated.

Combining β-CD with sulfonic surfactants yielded a novel nanotubular architecture which enhanced the rheological properties in aqueous phases.

The southern strait of Jeju is a divergence point of the Tsushima Warm Current (TWC), and it is the starting point of the thermohaline circulation in the waters of the Korean Peninsula, affecting the size and frequency of marine disasters such as typhoons and tsunamis, and has a very important oceanographic impact, such as becoming a source of harmful organisms and radioactively contaminated water. Therefore, for an immediate response to these maritime disasters, real-time ocean observation is required. However, compared to other straits, in the case of southern Jeju, such wide area marine observations are insufficient. Therefore, in this study, surface current field of the southern strait of Jeju was calculated using High-Frequency radar (HF radar). the large surface current field is calculated, and post-processing and data improvement are carried out through APM (Antenna Pattern Measurement) and FOL (First Order Line), and comparative analysis is conducted using actual data. As a result, the correlation shows improvement of 0.4~0.7 and RMSE of about 1~19 cm/s. These high-frequency radar observation results will help solve domestic issues such as response to typhoons, verification of numerical models, utilization of wide area wave data, and ocean search and rescue in the future through the establishment of an open data network.

The acaricidal activities of 86 plant extracts were investigated under laboratory conditions. The ethanol extract of Dioscorea japonica Thunb. root showed the strongest acaricidal activity, with 89.3% mortality against two-spotted spider mite, Tetranychus urticae Koch adults at a 2 mg/ml concentration. Bioassay-guided isolation of D. japonica root extract using silica gel open column chromatography, gas chromatography (GC), and gas chromatography–mass spectrometry (GC–MS) identified palmitic acid as the primary active compound. The acaricidal activities of palmitic acid against T. urticae were 91.2% and 69.7% at concentrations of 1 and 0.5 mg/ml, respectively. Among nine saturated fatty acids with carbon chains ranging from C8 to C26, the most vigorous acaricidal activity was observed with octanoic acid, followed by palmitic acid, and decanoic acid at a 1 mg/ml concentration. The acaricidal activity of the other fatty acids was less than 40% mortality at a 1 mg/ml concentration. These results indicate that a suitable carbon length is essential for fatty acids to exhibit acaricidal activity. The acaricidal efficacy of Eungjinssag (EJSG), an organic agricultural material authorized for the management of mites in the Republic of Korea, was compared to D. japonica root extract. At concentrations above 1 mg/ml, the acaricidal activity of D. japonica root extract was stronger than that of EJSG. The results of this study show that D. japonica root extract and palmitic acid are promising candidates as new environmentally-friendly control agents against two-spotted spider mite, which is one of the most severely damaging agricultural arthropod pests.

Parasitic moths are common in social wasp (Hymenoptera) nests, attacking many species of Polistinae and a few species of Vespinae. In the Republic of Korea, two moth species are known to parasitize the brood of Polistes rothneyi koreanus: Pyralis regalis (Pyralidae) and Anatrachyntis japonica (Cosmopterigidae). Although previously reported elsewhere, a novel case of parasitization was recently documented in the Republic of Korea, in which Hypsopygia mauritialis (Pyralidae) was identified in the nests of social wasps. Pyralis regalis is the most common parasitic moth in the Republic of Korea, feeding on the nests of 11 species of social wasps, mostly the Korean Vespa species. To that list of hosts, we add a species of Dolichovespula and two species of Polistes. Parasitism of Vespa velutina nigrithorax, an invasive alien hornet, by both P. regalis and H. mauritialis, was observed for the first time. However, their potential to control invasive alien hornets is expected to be low. This study provides new insights into the diversity of nest-parasitic moths in social wasp nests and their hosts in the Republic of Korea, and highlights the potential for these moths to impact pest populations.

This study aims to help firefighters conduct safe firefighting activities by revealing the factors affecting fire safety activities. The results of the study showed that accident experience had a significant effect on fire safety activities in terms of safety management competency, proactive response capability, safety learning capability and fire safety characteristics. Therefore, first, it is necessary to develop an easy-to-understand, simple and clear manual rather than a complicated standard disaster operation procedure to improve proactive response capability and establish a cooperative system for the smooth use of the resources of related organizations. Second, since safety learning competency has a positive effect on fire safety activities, it is necessary to systematize the education and training process on the management of the computerization of fire case data and advanced on-site response capabilities. Third, the direct and indirect accident experiences of firefighters reduce fire safety activities; therefore, the expansion of infrastructure, such as hospitals, legal support to strengthen the mental and physical stability of firefighters and a follow-up management system should be considered.

Superlattice (SL) phase change materials have shown promise to reduce the switching current and resistance drift of phase change memory (PCM). However, the effects of internal SL interfaces and intermixing on PCM performance remain unexplored, although these are essential to understand and ensure reliable memory operation. Here, using nanometer-thin layers of Ge

Parametric typhoon models reproduce realistic atmospheric pressure and wind fields during a typhoon. They require much less computation than planetary boundary layer models, allowing rapid coastal hazard estimations such as storm surges and waves. In these models, the maximum wind radius (Rmax) is a crucial parameter determining a wind field with the typhoon’s track and central pressure. This study proposes a new approach to Rmax estimation to generate accurate wind and pressure fields using numerical model data. We use the parametric typhoon model based on the basic vortex model. The track and central pressure of typhoons are obtained from the best track archives of the Joint Typhoon Warning Center (JTWC). Rmax was estimated hourly using circle fitting methods from the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) data. We tested this approach on five typhoons that passed near the Korean peninsula from 2016 to 2020. We evaluated the timeseries of Rmax with the JTWC archives. In addition, the prediction accuracy of storm surge and wave was compared using the reproduced wind field with Korea Operational Oceanographic System (KOOS). We also performed sensitivity tests for Rmax. This approach was tested on Typhoon Hinnamnor in 2022 with typhoon information from the Korea Meteorological Administration (KMA).

Many studies have focused on detecting coastal upwelling off the southeastern coast of Korea. Frequent occurrences of coastal upwelling are attributed to the persistent southwesterly (alongshore) wind blowing in the boreal summer season by the East Asian summer monsoon, reducing the surface water temperature by more than 5oC. Not just coastal upwelling cause variations in hydrodynamics, but it also gives rise to the primary production augmentation by phytoplankton blooms due to the supply of nutrients and fishery industry damage owing to sudden changes in water temperature. Accordingly, optimal coastal upwelling detection plays a crucial role in helping the augmentation of primary production and preventing industrial damage. Even though upwelling indices for detection are suggested, it would be inadequate to represent coastal upwelling compared with in-situ water temperature off the southeastern coast of Korea. Thus, we suggest upwelling-driven cold-water detection based on time-series observation, especially for real-time applications. By removing seasonal trends, we can define that an anomaly in sea surface temperature has occurred when the water temperature is out of natural variability (> 1σ). Furthermore, the suitability of the cold-water index was evaluated through an analysis between the index and the prerequisite when upwelling occurred, such as alongshore wind stress, wind duration, and vertical stratification.

Phosphorus, which is one of important factors of surface water eutrophication, has been the main issue in surface water quality management. In recent years, there has been an increasing interest in phosphorus in groundwater as well as surface water. Increasing number of studies has reported groundwater with high concentrations of phosphorus and its effect on adjacent surface water. The multi-level monitoring wells were installed in riparian zones of an agricultural area to demonstrate processes of phosphorus in groundwater. A stream in the area is largely in gaining condition, but losing condition was found in the area with extensive groundwater pumping. In this study, the processes of increasing and decreasing phosphorus concentration in groundwater under anaerobic conditions were examined with redox sensitive species. The dominant redox processes in groundwater were identified using redox sensitive parameters, which varied from oxic to sulfate reduction. Phosphorus concentrations were low in oxic and denitrification dominant condition and high in iron reducing dominant condition. This result was consistent with many recent studies. It is expected that phosphorus concentrations were reduced by precipitation of secondary iron minerals in the aerobic condition and increased by dissolution of the secondary minerals in the anaerobic condition. However, phosphorus concentration in the groundwater tended to attenuate under the more reducing condition than iron-reducing dominant condition. In this study, we tried to interpret dissolved phosphorus concentration in relation to the redox sensitive species and to understand the attenuation processes of dissolved phosphorus under strongly reducing conditions.

Background and Aims: Various guidewires are used for biliary cannulation, and each one has its own characteristics affecting its effectiveness. This study aimed to measure the basic properties and evaluate the effectiveness of a newly developed 0.025-inch guidewire for selective biliary cannulation. Methods: A total of 190 patients at five referral hospitals were randomly allocated to undergo selective biliary cannulation using the newly developed guidewire (NGW group, n = 95) or a conventional guidewire (CGW group, n = 95). The primary outcome was the selective biliary cannulation rate in naïve papillae. The secondary outcome was to measure the NGW basic properties, compare them with those of the CGW, and analyze the importance of basic property differences. Results: There were no significant differences between the groups in the baseline characteristics. The primary outcome (75.8% vs. 84.2%, p = 0.102) and adverse event rate (6.3% vs. 4.2%, p = 0.374) were similar in both groups. However, compared with the CGW group, the NGW group showed a higher number of ampulla contacts (2.58 vs. 2.02, p = 0.011) and longer cannulation time (216.5 vs. 135.1 s, p = 0.016). Furthermore, the NGW group had higher maximum friction (34.6 ± 1.34 vs. 30.2 ± 4.09), lower stiffness, and better elastic resiliency. In the multivariate analysis, a curved-tip GW (OR = 0.26, 95% CI 0.11–0.62, p = 0.002) and normal papillary shape (OR = 0.39, 95% CI 0.17–0.86, p = 0.021) were contributing factors for successful selective biliary cannulation. Conclusions: The NGW group had high friction and low stiffness, characteristics affecting biliary cannulation. Clinically, the NGW group had similar success and adverse event rates as the CGW, but they showed a higher number of ampulla contacts and longer cannulation time.

The occurrence of coastal upwelling is influenced by the intensity and duration of sea surface wind stress and geophysical components such as vertical stratification, bottom topography, and the entrainment of water masses. In addition, strong alongshore currents can drive upwelling. Accordingly, this study analyzes how wind stress and ocean currents contribute to changing coastal upwelling along the southwest coast of the East Sea (Japan Sea), which has not yet been reported quantitatively. This study aims to estimate each geophysical factor affecting upwelling processes using the Upwelling Age index. The index assesses the major contributors to the upwelling process using the relationship between physical forcing and upwelling water fraction estimated from shipboard hydrographic data from January 1993 to October 2018. These findings reveal that wind-driven upwelling was dominant off the northern coast. In contrast, current-driven upwelling prevailed off the southern coast. These results suggest that persistent alongshore currents through the Korea Strait make the southern region a prolific upwelling area. Accordingly, it can shed light on the mechanisms of coastal upwelling in the study area, which is crucial for understanding the influence of physical forces on ocean ecosystems.

Since the discovery of L-glutamate-producing Corynebacterium glutamicum, it has evolved to an industrial workhorse. For bio-based chemical production, suppling sufficient amounts of the NADPH cofactor is crucial. Glyceraldehyde-3-phosphate dehydrogenase (GapDH), a glycolytic enzyme that converts glyceraldehyde-3-phosphate (G3P) to 1,3-bisphosphoglycerate and produces NAD(P)H, is a major prospective solution for the cofactor imbalance issue. In this study, we determined the crystal structure of GapDH from C. glutamicum ATCC13032 (CgGapDH). This structural information was used to construct rational protein engineering strategies. We generated four CgGapDH variants that can produce both NADH and NAPDH. The final CgGapDHL36S/T37K/F100V/P192S variant showed a 212-fold increase in enzyme activity for NADP as well as 200% and 30% increased activity for the G3P substrate under NAD and NADP cofactor conditions, respectively. In addition, crystal structures of CgGapDH variants in complex with NAD(P) permit elucidation of differences between wild-type CgGapDH and variants in relation to cofactor stabilization.

The growing demand for various types of paper highlights the importance of optimizing the kraft pulping process to achieve desired paper properties. This work proposes a novel multiscale model to optimize the kraft pulping process and obtain desired paper properties. The model combines mass and energy balance equations with a layered kinetic Monte Carlo (kMC) algorithm to predict the degradation of wood chips, the depolymerization of cellulose, and the spatio-temporal evolution of the Kappa number and cellulose degree of polymerization (DP). A surrogate LSTM-ANN model is trained on data generated from the multiscale model under different operating conditions, dealing with both time-varying and time-invariant inputs, and an LSTM-ANN-based model predictive controller is designed to achieve desired set-point values of the Kappa number and cellulose DP while considering process constraints. The results show that the LSTM-ANN-based controller is able to drive the process to desired set-point values with the use of a computationally faster surrogate model with high accuracy and low offset.

Bioconversion of the C1 compounds into value-added products is one of the CO