• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.376-383
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• 2011

The CMCs of LA and LA3 nonionic surfactants obtained from the reaction between glycidol and lauryl alcohol were found to be $0.97{\times}10^{-3}mol/L$ and $1.02{\times}10^{-3}mol/L$ respectively and the surface tensions for 1 wt% surfactant were 26.99 and 27.48 mN/m respectively. Dynamic surface tension measurements using a maximum bubble pressure tensiometer showed that the adsorption rate of surfactant molecules at the interface between the air and the surfactant solution was found to be relatively fast in both surfactant systems, presumably due to the high mobility of surfactant molecules. The contact angles of LA and LA3 nonionic surfactants were 27.8 and $20.9^{\circ}$ respectively and the dynamic interfacial tension measurement by a spinning drop tensiometer showed that interfacial tensions at equilibrium condition in both systems were almost the same. Also both surfactant systems reached equilibrium in 2~3 min. Both surfactant solutions showed high stability when evaluated by conductometric method and the LA nonionic surfactant system provided the higher foam stability than the LA3 nonionic surfactant system. The phase behavior experiments showed a lower phase or oil in water (O/W) microemulsion in equilibrium with an excess oil phase at all temperatures studied. No three-phase region was observed including a middle-phase microemulsion or a lamellar liquid crystalline phase.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.562-565
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• 2011

In this study, we developed a bioprocess using Clostridium ljungdahlii as a biological catalyst to produce bio-ethanol, and the effect of pH on microbial growth and ethanol production was investigated. From the results of fermentation at various initial pH condition without pH control, pH of fermentation broth decreased to 4.5 within 24 h due to accumulation of by-product acetic acid and both microbial growth and ethanol production were stopped. The experimental result of initial pH 8 showed the highest microbial growth and ethanol production (0.53 g/L), since the pH drop was relatively slow. From the experiment of pH 7 maintained fermentation using pH controllable bioreactor, the maximum cell dry weight of 1.65 g/L and the maximum ethanol concentration of 1.43 g/L were obtained within 24 h. In conclusion, the C. ljungdahlii growth was enhanced by pH maintenance of neutral range, and the ethanol production was also enhanced based on the growth-associated ethanol production characteristics of C. ljungdahlii.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1315-1323
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• 2018

We studied the carbonization due to the annealing condition of waste coffee powder for application as an active anode material for lithium-ion batteries (LIBs). The coffee powder used as an active anode material for LIBs was obtained from coffee beans, not from a coffee shells. The waste coffee powder was dried in air and heat-treated in an $Ar/H_2$ atmosphere to obtain a pore-forming activated carbon powder. The specific capacity of the sample annealed at $700^{\circ}C$ was still 303 mAh/g after 1000 cycles at a current density of 1000 mA/g and with a coulombic efficiency of over 99.5%. The number of pores and the pore size of the waste coffee powder were increased due to chemical treatment with KOH, which had the some effect as an increased specific surface area. The waste coffee powder is considered to be a very promising active anode material because of both its excellent electrochemical properties due to enhanced carrier conduction and its being a cost effective resource for use in LIBs.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.32 no.1
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• pp.15-23
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• 2021

Background and Objectives During speech, the vocal folds oscillate at frequencies ranging from 100-200 Hz with amplitudes of a few millimeters. Mechanical stimulation is an essential factor which affects metabolism of human vocal folds. The effect of mechanical vibration on the cellular response in the human vocal fold fibroblasts cells (hVFFs) was evaluated. Materials and Method We created a culture systemic device capable of generating vibratory stimulations at human phonation frequencies. To establish optimal cell culture condition, cellular proliferation and viability assay was examined. Quantitative real time polymerase chain reaction was used to assess extracellular matrix (ECM) related and growth factors expression on response to changes in vibratory frequency and amplitude. Western blot was used to investigate ECM and inflammation-related transcription factor activation and its related cellular signaling transduction pathway. Results The cell viability was stable with vibratory stimulation within 24 h. A statistically significant increase of ECM genes (collagen type I alpha 1 and collagen type I alpha 2) and growth factor [transforming growth factor β1 (TGF-β1) and fibroblast growth factor 1 (FGF-1)] observe under the experimental conditions. Vibratory stimulation induced transcriptional activation of NF-κB by phosphorylation of p65 subunit through cellular Mitogen-activated protein kinases activation by extracellular signal regulated kinase and p38 mitogen-activated protein kinases (MAPKs) phosphorylation on hVFFs. Conclusion This study confirmed enhancing synthesis of collagen, TGF-β1 and FGF was testified by vibratory stimulation on hVFFs. This mechanism is thought to be due to the activation of NF-κB and MAPKs. Taken together, these results demonstrate that vibratory bioreactor may be a suitable alternative to hVFFs for studying vocal folds cellular response to vibratory vocalization.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.234-247
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• 2021

We used a heterozygous gene deletion library of fission yeasts comprising all essential and non-essential genes for a microarray screening of target genes of the antifungal terbinafine, which inhibits ergosterol synthesis via the Erg1 enzyme. We identified 14 heterozygous strains corresponding to 10 non-essential [7 ribosomal-protein (RP) coding genes, spt7, spt20, and elp2] and 4 essential genes (tif302, rpl2501, rpl31, and erg1). Expectedly, their erg1 mRNA and protein levels had decreased compared to the control strain SP286. When we studied the action mechanism of the non-essential target genes using cognate haploid deletion strains, knockout of SAGA-subunit genes caused a down-regulation in erg1 transcription compared to the control strain ED668. However, knockout of RP genes conferred no susceptibility to ergosterol-targeting antifungals. Surprisingly, the RP genes participated in the erg1 transcription as components of repressor complexes as observed in a comparison analysis of the experimental ratio of erg1 mRNA. To understand the action mechanism of the interaction between the drug and the novel essential target genes, we performed isobologram assays with terbinafine and econazole (or cycloheximide). Terbinafine susceptibility of the tif302 heterozygous strain was attributed to both decreased erg1 mRNA levels and inhibition of translation. Moreover, Tif302 was required for efficacy of both terbinafine and cycloheximide. Based on a molecular modeling analysis, terbinafine could directly bind to Tif302 in yeasts, suggesting Tif302 as a potential off-target of terbinafine. In conclusion, this genome-wide screening system can be harnessed for the identification and characterization of target genes under any condition of interest.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.211-218
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• 2021

This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.35-42
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• 2022

The article deals with the role of extra-curricular work by means of multimedia technologies in order to improve the quality of training of future specialists. An important condition for achieving high results in training specialists is the optimal combination of classroom and independent extra-curricular work of students by means of multimedia technologies. Very significant is the development of student independence, the formation of skills of independent search activity, the ability to take responsibility, independently solve a problem, find constructive solutions, a way out of a crisis situation, and so on. Extra-curricular work forms students' ability to master the techniques of analysis, synthesis, generalization, comparison; develops flexibility of thinking; opens up opportunities for the development and stabilization of positive learning motives to activate the process of mastering knowledge by means of multimedia technologies as a means of forming the personality of a highly qualified specialist. The concept of multimedia as one of the priority areas of Information Technology, which plays a particularly important role in the process of informatization of education, is revealed, and its advantages in education are shown. The advent of multimedia systems optimizes transformations in education, in many areas of professional activity, science, art, etc. The necessity of distance learning to improve the quality of training of future specialists using multimedia technologies in extra-curricular work is justified. The effectiveness of pedagogical support in the process of distance learning is achieved by the following conditions, which is revealed in the article. Various forms and types of extra-curricular work of students that are used in the modern practice of the educational environment of a higher education institution are described. Scientific and informational activity is considered a key area of information activity. The analysis of scientific and information activities in the field of education allows us to identify its main functions, which emphasize the growing role of scientific information in the education system, in particular, extra-curricular work using multimedia technologies. Operational, complete, accurate, targeted information that meets objective and subjective needs becomes an important link between the field of management, science and practice.

• Journal of Nutrition and Health
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• v.56 no.5
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• pp.469-482
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• 2023

Purpose: Obesity has emerged as a critical global public health concern as it is associated with and increases susceptibility to various diseases. This condition is characterized by the excessive enlargement of adipose tissue, primarily stemming from an inequity between energy intake and expenditure. The purpose of this study was to investigate the potential of sweet pumpkin powder in mitigating obesity and metabolic disorders in leptin-deficient obese (ob/ob) mice and to compare the effects of raw sweet pumpkin powder (HNSP01) and heat-treated sweet pumpkin powder (HNSP02). Methods: Leptin-deficient obese mice were fed a diet containing 10% HNSP01 and another containing 10% HNSP02 for 6 weeks. Results: The supplementation of ob/ob mice with HNSP01 and HNSP02 resulted in decreased body weight gain, reduced adipose tissue weight, and a smaller size of lipid droplets in the adipose tissue and liver. Furthermore, the ob/ob-HNSP01 and ob/ob-HNSP02 supplemented groups exhibited lower levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, fasting blood glucose, and insulin, as well as a reduced atherogenic index in comparison with the control group. Molecular analysis also demonstrated that the intake of HNSP01 and HNSP02 resulted in a diminished activation of factors associated with fatty acid synthesis, including acetyl-CoA carboxylase and fatty acid synthase, while concurrently enhancing factors associated with lipolysis, including adipose triglyceride lipase and hormone-sensitive lipase, in the adipose tissue. Conclusion: Taken together, these findings collectively demonstrate the potential of sweet pumpkin powder as a functional food ingredient with therapeutic properties against obesity and its associated metabolic disorders, such as insulin resistance and dyslipidemia.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1635-1647
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• 2023

Muscle atrophy, which is defined as a decrease in muscle mass and strength, is caused by an imbalance between the anabolism and catabolism of muscle proteins. Thus, modulating the homeostasis between muscle protein synthesis and degradation represents an efficient treatment approach for this condition. In the present study, the protective effects against muscle atrophy of ethanol extracts of Morus alba L. (MA) and Angelica keiskei Koidz. (AK) leaves and their mixtures (MIX) were evaluated in vitro and in vivo. Our results showed that MIX increased 5-aminoimidazole-4-carboxamide ribonucleotide-induced C2C12 myotube thinning, and enhanced soleus and gastrocnemius muscle thickness compared to each extract alone in dexamethasone-induced muscle atrophy Sprague Dawley rats. In addition, although MA and AK substantially improved grip strength and histological changes for dexamethasone-induced muscle atrophy in vivo, the efficacy was superior in the MIX-treated group. Moreover, MIX further increased the expression levels of myogenic factors (MyoD and myogenin) and decreased the expression levels of E3 ubiquitin ligases (atrogin-1 and muscle-specific RING finger protein-1) in vitro and in vivo compared to the MA- and AK-alone treatment groups. Furthermore, MIX increased the levels of phosphorylated phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR) that were reduced by dexamethasone, and downregulated the expression of forkhead box O3 (FoxO3a) induced by dexamethasone. These results suggest that MIX has a protective effect against muscle atrophy by enhancing muscle protein anabolism through the activation of the PI3K/Akt/mTOR signaling pathway and attenuating catabolism through the inhibition of FoxO3a.

• The Journal of the Acoustical Society of Korea
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• v.29 no.1
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• pp.48-55
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• 2010

It has a falling off in speech quality, especially when consecutive packet loss occurs, even if a vocoder implemented in the packet network has its own packet loss concealment (PLC) algorithm. PLC algorithm is divided into transmitter and receiver algorithm. Algorithm in the transmitter gives superior quality by additional information. however it is impossible to provide mutual compatibility and it occurs extra delay and transmission rate. The method applied in the receiver does not require additional delay. However, it sets limits to improve the speech quality. In this paper, we propose a new method that puts extra information for PLC in a part of Extension Header Data which is not used in RTP Header. It can solve the problem and obtain enhanced speech quality. There is no extra delay occurred by the proposed algorithm because there is a jitter buffer to adjust network delay in a receiver. Extra information, 16 bits each frame for G.729 PLC, is allocated for MA filter index in LP synthesis, excitation signal, excitation signal gain and residual gain reconstruction. It is because a transmitter sends speech data each 20 ms when it transfers RTP payload. As a result, the proposed method shows superior performance about 13.5%.