Gyeongsang National University
  • Chinju, Gyeongnam, South Korea
Recent publications
Ob/ob mice are leptin-deficient animals with uninhibited food intake and susceptibility to gain weight and develop type 2 diabetes. The mice have been used to study obesity and diabetes. We generated a dataset of different tissue gene expressions from wild-type and ob/ob mice with a normal diet (ND) or high-fat diet (HFD). The gene expression was profiled at a genome-scale using RNA-seq. We deposited the raw data to the short read archive and the processed data to the gene expression omnibus. In this manuscript, we describe generating the dataset and technical validation of the gene expression profiles. We assessed the quality of the reads, alignment, and the quantification of gene expression. We found that the tissue of origin explained the most variance between samples. Non-coding features differed in their contribution to the mice profiles. Gene expression profiles diverged between the experimental groups. To sum, this dataset can be used to study tissue-specific gene expression in weight gain susceptible mice and the response to HFD.
We evaluated whether the neutrophil-to-lymphocyte ratio (NLR) could aid dialysis decision-making in combination with the clinical presentation and biochemical findings. We retrospectively evaluated the medical records of 279 patients who commenced chronic maintenance hemodialysis. We compared the laboratory findings at 6 months before dialysis to those at dialysis initiation. NLR cutoffs and risk factors for each of six uremic symptoms were determined. Mean age was 60.7 years and mean estimated glomerular filtration rate (eGFR) was 5.7 ± 2.5 mL/min/1.73 m² at the time of hemodialysis and 7.7 ± 3.8 mL/min/1.73 m² 6 months earlier (p < 0.001). The mean NLR increased significantly from 2.5 ± 1.0 to 4.9 ± 2.8 (p < 0.001). The NLR was positively correlated with the C-reactive protein level (r = 0.202, p = 0.009) and negatively correlated with those of albumin (r = −0.192, p = 0.001) and total CO2 (r = −0.134, p = 0.023). The NLR cutoffs for neurological and gastrointestinal symptoms as determined using receiver operator curve analysis were 2.4 (area under the curve [AUC] 0.976; 95% confidence interval [CI] 0.960–0.993; sensitivity 92.2%; specificity 94.7%) and 3.6 (AUC 0.671; 95% CI 0.588–0.755; sensitivity 68.1%; specificity 63.5%), respectively. On multiple linear regression analysis of neurological symptoms, the NLR was a significant predictor (β = −0.218, p = 0.017), as was age (β = 0.314, p = 0.037). In conclusion, the NLR may serve as a supplementary marker predicting uremic symptoms and a need for hemodialysis in stage 5 CKD patients.
Objective To disseminate the portable sequencer MinION in developing countries for the main purpose of battling infectious diseases, we found a consortium called Global Research Alliance in Infectious Diseases (GRAID). By holding and inviting researchers both from developed and developing countries, we aim to train the participants with MinION’s operations and foster a collaboration in infectious diseases researches. As a real-life example in which resources are limited, we describe here a result from a training course, a metagenomics analysis from two blood samples collected from a routine cattle surveillance in Kulan Progo District, Yogyakarta Province, Indonesia in 2019. Results One of the samples was successfully sequenced with enough sequencing yield for further analysis. After depleting the reads mapped to host DNA, the remaining reads were shown to map to Theileria orientalis using BLAST and OneCodex. Although the reads were also mapped to Clostridium botulinum, those were found to be artifacts derived from the cow genome. An effort to construct a consensus sequence was successful using a reference-based approach with Pomoxis. Hence, we concluded that the asymptomatic cow might be infected with T. orientalis and showed the usefulness of sequencing technology, specifically the MinION platform, in a developing country.
Piperonal is a simple aromatic aldehyde compound with a characteristic cherry-like aroma and has been widely used in the flavor and fragrance industries. Despite piperonal being an important aroma in black pepper (Piper nigrum), its biosynthesis remains unknown. In this study, the bioinformatic analysis of the P. nigrum transcriptome identified a novel hydratase-lyase, displaying 72% amino acid identity with vanillin synthase, a member of the cysteine proteinase family. In in vivo substrate-feeding and in vitro enzyme assays, the hydratase-lyase catalyzed a side-chain cleavage of 3,4-methylenedioxycinnamic acid (3,4-MDCA) to produce 3,4-methylenedioxybenzaldehyde (piperonal) and thus was named piperonal synthase (PnPNS). The optimal pH for PnPNS activity was 7.0, and showed a K m of 317.2 μM and a k cat of 2.7 s-1. The enzyme was most highly expressed in the leaves, followed by the fruit. This characterization allows for the implementation of PnPNS in various microbial platforms for the biological production of piperonal. Supplementary information: The online version contains supplementary material available at 10.1186/s13765-022-00691-0.
In this study, we investigated the effects of dicaffeoylquinic acid derivatives, including 1,4-di-O-caffeoylquinic acid (1,4-DCQA), 3,4-di-O-caffeoylquinic acid (3,4-DCQA), 3,5-di-O-caffeoylquinic acid (3,5-DCQA), 4,5-di-O-caffeoylquinic acid (4,5-DCQA), and 1,5-di-O-caffeoylquinic acid (1,5-DCQA) on glucose-stimulated insulin secretion (GSIS) activity and α-glucosidase activity were compared in rat INS-1 pancreatic β-cells. The α-glucosidase inhibitory activities of dicaffeoylquinic acid derivatives were as follows: 1,4-DCQA > 1,5-DCQA > 3,4-DCQA > 4,5-DCQA > 3,5-DCQA. In INS-1 cells, dicaffeoylquinic acid derivatives showed no cytotoxic effect at any concentration (2.5–10 μM). In addition, the GSIS activities of dicaffeoylquinic acid derivatives were as follows: 4,5-DCQA > 3,4-DCQA > 1,4-DCQA > 3,5-DCQA > 1,5-DCQA. Treatment of INS-1 cells with 4,5-DCQA resulted in a marked increase in protein expression of extracellular signal-regulated protein kinases (ERK), insulin receptor substrate-2 (P-IRS-2), Akt, phosphoinositide 3-kinase (P-PI3K), and pancreatic and duodenal homeobox-1 (PDX-1), which might be related to its GSIS activity in INS-1 cells. These findings indicate that the location of the dicaffeoyl functional group influences the anti-diabetic activity of quinic acid.
Triboelectric nanogenerator (TENG) uses charge transfer between two asymmetric charge affinity materials such as metal and dielectrics. Metal electrode acts as charge collector from dielectrics and acts as charge transfer path to an external load, which model deals with only a net charge of metal electrode concerning electrical output. In this work, we found that metal electrode in triboelectric generator has non-negligible surface charge polarization causing open-circuit voltage difference in the model TENG system. The output voltage depends on the initial preparation conditions of the TENG for I–V measurements, even for the same measured charge densities. The measured output voltage difference with the same charge density implies that electric charges of TENG are composed of movable charges that affect current and voltage output and the bounded fixed charges that only affect open-circuit voltage.
Para -aminosalicylic acid (PAS) is an antibiotic that was largely used for the multi-therapy of tuberculosis in the twentieth century. To try to overcome the inconvenience of its low efficacy and poor tolerance, we searched for novel chemical entities able to synergize with PAS using a combination screening against growing axenic Mycobacterium tuberculosis . The screening was performed at a sub-inhibitory concentration of PAS on a library of about 100,000 small molecules. Selected hit compounds were analyzed by dose–response and further probed with an intracellular macrophage assay. Scaffolds with potential additive effect with PAS are reported, opening interesting prospects for mechanism of action studies. We also report here evidence of a yet unknown bio-activation mechanism, involving activation of pyrido[1,2-a]pyrimidin-4-one (PP) derivatives through the Rv3087 protein.
Electric vertical take-off and landing (eVTOL) aircraft with multiple lifting rotors or prop-rotors have received significant attention in recent years due to their great potential for next-generation urban air mobility (UAM). Numerical models have been developed and validated as predictive tools to analyze rotor aerodynamics and wake dynamics. Among various numerical approaches, the vortex method is one of the most suitable because it can provide accurate solutions with an affordable computational cost and can represent vorticity fields downstream without numerical dissipation error. This paper presents a brief review of the progress of vortex methods, along with their principles, advantages, and shortcomings. Applications of the vortex methods for modeling the rotor aerodynamics and wake dynamics are also described. However, the vortex methods suffer from the problem that it cannot deal with the nonlinear aerodynamic characteristics associated with the viscous effects and the flow behaviors in the post-stall regime. To overcome the intrinsic drawbacks of the vortex methods, recent progress in a numerical method proposed by the authors is introduced, and model validation against experimental data is discussed in detail. The validation works show that nonlinear vortex lattice method (NVLM) coupled with vortex particle method (VPM) can predict the unsteady aerodynamic forces and complex evolution of the rotor wake.
With the growing interest in wearable devices in recent decades, considerable effort has been devoted to developing mechanical elastomeric devices such as sensors, transistors, logic circuits, and integrated circuits. To successfully implement elastomeric devices subjected to large mechanical deformations or stretching, all the components, including conductors, semiconductors, and dielectrics, must have high stability and mechanical sustainability. Elastomeric conductors, which exhibit excellent electrical performances under mechanical deformations, are key components of elastomeric devices. Herein, we prepared fully elastomeric electrodes based on interconnected 2D gold nanosheets (AuNSs) to develop mechanically resilient integrated electronics. The AuNS elastomeric electrodes exhibited a sheet resistance of less than 2 Ω/sq under 50% stretching and sustained 100,000 stretching–releasing cycles. These electrodes with a dedicated design were used in combination with elastomeric semiconductors of P3HT nanofibrils in the PDMS elastomer (P3NF/PDMS) and an ion gel as a dielectric to realize elastomeric transistors, inverters, and NOR and NAND logic gates. Additionally, an elastomeric 8 × 8 transistor array that can sustain various types of mechanical stimuli was successfully demonstrated. Furthermore, the elastomeric electronic devices implemented on a soft robot showed no interfering performances during robot gripping motion. The proposed framework is expected to aid in the rapid development and broaden the application scope of soft electronics.
Background Retinoic acid is a major metabolite of vitamin A and exerts beneficial effects including anti-oxidant and anti-inflammatory activities in neurons. The ubiquitin–proteasome system is an important biological system that regulates cell survival. Ubiquitination regulates protein degradation and plays an important role in oxidative stress. Deubiquitinating enzymes cleave ubiquitin from proteins and control ubiquitination-induced degradation. We detected decreases in ubiquitin carboxy-terminal hydrolase L1, ubiquitin thioesterase OTUB1, and proteasome subunit alpha types 1 and 3 in cerebral ischemic damage. In this study, we investigated whether retinoic acid regulates the expression of deubiquitinating enzymes ubiquitin carboxy-terminal hydrolase L1, ubiquitin thioesterase OTUB1, and proteasome subunit alpha types 1 and 3 in cerebral ischemic injury. Right middle cerebral artery occlusion (MCAO) was performed to induce cerebral ischemic damage in male rats. Retinoic acid (5 mg/kg) or vehicle was intraperitoneally injected every day from 4 days before surgery. Neurological behavioral tests were performed 24 h after MCAO, and right cerebral cortical tissues were collected. Results MCAO damage caused neurological behavioral dysfunction, and retinoic acid alleviated these deficits. The identified proteins decreased in MCAO animals with vehicle, while retinoic acid treatment attenuated these decreases. The results of proteomic study were confirmed by a reverse transcription-PCR technique. Expressions of ubiquitin carboxy-terminal hydrolase L1, ubiquitin thioesterase OTUB1, and proteasome subunit alpha types 1 and 3 were decreased in MCAO animals treated with vehicle. Retinoic acid treatment alleviated these MCAO-induced reductions. The ubiquitin–proteasome system plays an essential role in maintaining cell function and preserving cell shape against ischemic damage. Conclusions These findings suggest that retinoic acid regulates ubiquitin- and proteasome-related proteins including ubiquitin carboxy-terminal hydrolase L1, ubiquitin thioesterase OTUB1, and proteasome subunit alpha types 1 and 3 in a brain ischemia model. Changes in these proteins are involved in the neuroprotective effects of retinoic acid.
The use of Pipelines for long-distance transportation of crude oil, natural gas and similar applications is increasing and has pivotal importance in recent times. High specific strength plays a crucial role in improving transport efficiency through increased pressure and improved laying efficiency through reduced diameter and weight of line pipes. TRIP-based high-strength and high-ductility alloys comprise a mixture of ferrite, bainite, and retained austenite that provide excellent mechanical properties such as dimensional stability, fatigue strength, and impact toughness. This study performs microstructure analysis using both Nital etching and LePera etching methods. At the time of Nital etching, it is difficult to distinctly observe second phase. However, using LePera etching conditions it is possible to distinctly measure the M/A phase and ferrite matrix. The fraction measurement was done using OM and SEM images which give similar results for the average volume fraction of the phases. Although it is possible to distinguish the M/A phase from the SEM image of the sample subjected to LePera etching. However, using Nital etching is nearly impossible. Nital etching is good at specific phase analysis than LePera etching when using SEM images.
Background: Gastrointestinal microbiota, which comprises hundreds of different types of microbes, biologically plays crucial roles in the host's health. Probiotics (PRO) did not always have a positive benefit on the host, depending on strains of microbes and the physiochemical properties of prebiotics (PRE), indicating that the properties of PRE in combination with PRO might have different effects on the gut ecology. The aim of this study was to assess the effects of insoluble or soluble PRE with PRO on intestinal digestive hydrolase, the fecal microbes, and immunological biomarkers in SD rats fed an AIN-93G diet. Results: Forty, 8-week-old SD rats were randomly assigned to 4 groups with 10 replicates in each; cellulose (CELL), cellulose + probiotics (CELPRO), oatmeal (OATS), and oatmeal + probiotics (OATPRO) groups. After 4-week feeding trial, rats were treated with saline or lipopolysaccharide (LPS, 1 mg/kg) to examine the alleviating effects of PRO and PRE on immunological responses. There was a significant (p < 0.05) decrease in feed intake of rats fed the oatmeal supplemented diet without affecting growth performance. Blood triglyceride was significantly (p < 0.05) decreased in rats fed the oatmeal diet, and aspartate aminotransferase (AST) was significantly (p < 0.05) decreased in rats fed the PRO supplemented diet. Intestinal maltase, sucrose, and lactase activities were significantly (p < 0.05) higher in rats fed PRO compared with rats not fed PRO. Rats fed the oatmeal showed a significant (p < 0.01) increase in the fecal colony forming units (CFU) of Lactobacillus plantarum, Bacillus subtilis, and Saccharomyces cerevisiae compared with those fed cellulose. LPS-treated rats fed PRO showed a significant (p < 0.05) increase in blood secretory immunoglobulin A (sIgA) compared with those not fed PRO. The LPS-treated rats fed PRO resulted in decreased (p < 0.05) blood IL-6 compared with those not fed PRO, indicating that a dietary PRO alleviated inflammatory response in LPS-treated rats. Conclusions: Dietary oatmeal increased fecal microbes, and PRO supplement resulted in increased intestinal hydrolase and immune functions of the host, demonstrating that soluble PRE with supplemented with PRO could be a more bioactive combination of synbiotics in SD rats.
Terpenoids are of great interests in a broad range of health-beneficial biological activities and various industrial applications. In plants, terpenoids are synthesized by two distinct pathways, methylerythritol phosphate (MEP) and mevalonate pathways in a separate location. MEP pathway supplies isoprene precursors isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP) of terpenoid biosynthesis in plant plastids. The MEP pathway has been an engineering target to increase the metabolic flux towards higher terpenoid production in plants. 1-Hydroxy-2-methyl-2-( E )-butenyl-4-diphosphate reductase (HDR) is the terminal step of the MEP pathway to regulate the terpenoid biosynthesis and is encoded by three paralogous genes in Ginkgo biloba. In this study, we assessed the effect of overexpression of GbHDR1 on terpenoid metabolism in poplar plants. Overexpression of GbHDR1 in poplar plants accelerated growth and delayed winter-bud formation. Transcript levels of gibberellin, chlorophylls, and carotenoid biosynthetic genes in GbHDR1- overexpressing ( GbHDR1 ox) poplars were up-regulated, suggesting metabolic flux enhancement. Moreover, enhanced contents of chlorophylls and carotenoids in the leaves of the GbHDR1 ox plants resulted in a higher photosynthetic rate as a consequence. Therefore, we expect the GbHDR1 overexpression will be a desirable engineering point of the MEP pathway for enhancing terpenoid metabolic flux and production in plants.
The room temperature sodium-sulfur (RT/NaS) battery provides a potential energy storage technology with high theoretical capacity and low cost. However, the gap between its practical performance and theoretical expectation confines its comprehensive implementation. In this work, a simple annealing process successfully synthesized a hierarchical micro/mesoporous egg carbon with KOH activation (ECK) from albumen as sulfur hosting for RT/NaS batteries. KOH activation plays a vital role in enhancing conductivity, surface area, and porosity. Elemental sulfur was loaded to the ECK through simple heat evaporation to form an ECK@S composite. Even at the high rate of 1 C, the discharge capacity of the ECK@S electrode reached 473 mAh/g and maintained 202 mAh/g after 800 cycles, representing an outstanding performance. Therefore, preparing micro/mesoporous egg carbon by KOH activation creates a promising electrode material for RT/NaS batteries.
Bioelectrohydrogenesis using a microbial electrolysis cell (MEC) is a promising technology for simultaneous hydrogen production and wastewater treatment which uses electrogenic microbes. Microbial activity at the anode and hydrogen evolution reaction at the cathode can be controlled by electrode–microbe interaction and electron transfer. The selection of anode electrode material is governed by electrochemical oxidation of substrates and subsequent electron transfer to the anode. Similarly, a good cathodic material should reduce the overpotential at the cathode and enhance the hydrogen evolution reaction and H2 recovery. This review mainly focused on modifications in electrode materials and cheaper novel alternatives to improve the performance for MEC and overcome its scale-up challenges for practical applications. Performance of various anode and cathode materials based on Ni alloys, stainless steel, polyaniline, palladium, and carbon has been discussed. The scalability of the material should consider its inexpensive fabrication procedure and efficiency.
In this study, we aimed to evaluate the properties and mechanisms of heavy metal adsorption by biochar derived from fallen leaves (FLB). The optimum manufacturing temperature of FLB for heavy metal removal was 650 °C, which resulted in a high carbon content and specific surface area. The maximum adsorption capacities of Cd and Pb by FLB650 were 86.2 and 135.1 mg/g, respectively; their adsorption was achieved via chemisorption. The results from chemisorption agreed with the Langmuir isotherm and pseudo-second order models. We confirmed that the adsorption of Pb by FBL was dominantly affected by the surface boundary layer; however, the adsorption of Cd occurred in cooperation with the boundary layer and pore diffusion; which was accomplished by employing the intraparticle diffusion model. After heavy metal adsorption, the distribution characteristics and mechanisms of each heavy metal in the FLB were noticeably observed through SEM-EDS, FTIR, and XRD. In addition, the content of exchangeable cations released from the FLB during the heavy metal adsorption process corresponded to 52% for Cd and 34% for Pb of the total amount of adsorbed heavy metals. We determined that FLB exhibits high affinity for heavy metals and its adsorption occurs via an adsorption mechanism based on the properties of FLB.
Front Cover: The cover image is based on the Research Article Biallelic variants in WARS1 cause a highly variable neurodevelopmental syndrome and implicate a critical exon for normal auditory function by Sheng‐Jia Lin et al., https://doi.org/10.1002/humu.24435.
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1,480 members
Suvendu Das
  • Institute of Agriculture and Life Science
Woe Yeon Kim
  • Department of Agricultural Chemistry
Akshat Goel
  • College of Agricultural and Life Science
Fernand Ferando Fagutao
  • College of Veterinary Medicine
Tae Sung Jung
  • College of Veterinary Medicine
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816 beongil 15, Jinju-daero, 52717, Chinju, Gyeongnam, South Korea