• Journal of the korean society of oceanography
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• v.34 no.4
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• pp.200-206
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• 1999

Seawater sampling is the primary task for the study of the marine environmental parameters that require shipboard or laboratory experiments for their analyses, and is also required for the calibration of some instruments for in situ measurement. A new automatic bottle (AUTTLE) is developed for seawater sampling at any desired time and water depth by self-triggering. Both any type of single or assembled mooring for 15 days and manual actuation by using a remote messenger as existing instantaneous single point water samplers are possible. Its sampling capacity and the resolution of time setting are 2 liters and 1 second, respectively. The result of a field experiment with an optical backscattering sensor (OBS) and a total of 14 AUTTLES for the in situ calibration of the OBS shows that the AUTTLE must improve our understanding on the behavior of the sand/mud mixtures in the environments with high waves and strong tides. The AUTTLE will serve as a valuable instrument in the various fields of oceanography, especially where synchronized seawater sampling at several sites is required and/or the information in storm period is important.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2187-2192
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• 2011

Hydrogen peroxide plays a key role as a second messenger in the normal cellular signaling but its overproduction has been implicated in various life-threatening diseases. Peroxalate chemiluminescence is the light emission from a three component reaction between peroxalate, hydrogen peroxide and fluorophores. It has proven great potential as a methodology to detect hydrogen peroxide in physiological environments because of its excellent sensitivity and specificity to hydrogen peroxide. We developed chemiluminescent micelles composed of amphiphilic polymers, peroxalate and fluorescent dyes to detect hydrogen peroxide at physiological concentrations. In this work, we studied the relationship between the chemiluminescence reactivity and stability of peroxalate by varying the substitutes on the aryl rings of peroxalate. Alkyl substitutes on the aryl ring of peroxalate increased the stability against water hydrolysis, but diminished the reactivity to hydrogen peroxide. Chemiluminescent micelles encapsulating diphenyl peroxalate showed significantly higher chemiluminescence intensity than the counterpart encapsulating dimethylphenyl or dipropylphenyl peroxalate. Diphenyl peroxalate-encapsulated micelles could detect hydrogen peroxide generated from macrophage cells stimulated by lipopolysaccharide (LPS) and image hydrogen peroxide generated during LPS-induced inflammatory responses in a mouse.

• YAKHAK HOEJI
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• v.35 no.1
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• pp.45-60
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• 1991

lonophores, uniquely, create specific pathways of ion permeability in model and cell membranes. Calcium-transporting ionophores of microbiological origin, such as A23187 and ionomycin, have been used as experimental tools to elucidate the physiological role of calcium as a second messenger in many cell types. These ionophores are believed to bypass the initial ligand-receptor step in the activation of cells by increasing membrane permeability to calcium. In this report, we shall discuss several naturally occurring substances that share some properties of calcium-ionophores, primarily concentrating on oxidized fatty acids. We have previously demonstrated that oxidized linoteic and arachidonic acids, obtained either by lipoxygenase catalysis or nonenzymatic processes, significantly promote calcium translocation in a two-phase partition model and modulate calcium-transporting function in the isolated sarcoplasmic reticulum vesicles obtained from mammalian hearts. We have also confirmed that calcium-ionophoric properties are due not to their general amphiphilic nature of certain lipids, but to distinct structural characteristics. Although there are some skeptical views on the occurrence of ionophores in higher organisms, increasing evidence suggests that membrane lipids or their derivatives may serve as physiological calcium-ionophores. Abnormal accumulation of lipid peroxidation products(particularly end products), however, may be associated with the general oxidative damages as seen in many pathological conditions.

• Journal of Plant Biology
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• v.38 no.3
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• pp.243-250
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• 1995

Involvement of calcium in signal transduction of salt stress was investigated in 1.7 M NaCl adapted Dunaliella salina, extremely halotolerant, unicellular green alga. When hyperosmotic (3.4 M NaCl) or Hypoosmotic (0.8 M NaCl) stress was treated, extracellular calcium was influxed in or intracellular calcium effluxed from D. salina, respectively, and these fluxes were proportional to the degree of stress. This might indicate indirectly that the change of calcium level occurred within the cells. In addition, the change of calcium flux was ahead of glycerol synthesis which has been known as the physiological response to salt stress. Osmoregulation was affected byextracellular calcium concentration, and increase of glycerol content as an osmoticum was inhibited about 50% by treatment of TFP and W-7 known as calmodulin specific inhibitors. Furthermore, in the case of the hyperosmotic stressed cells, the amount of 21 kD and 39 kD protein appeared to be calcium binding protein were increased. Among these, the 39 kD protein was detected only in the hyperosmotic stressed cells. The results obtained in the present work suggest that the possibility of calcium as a second messenger in the transduction of salt stress signal exists in the osmoregulation system of D. salina.

• BMB Reports
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• v.44 no.3
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• pp.147-157
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• 2011

The meiotic process from the primordial stage to zygote in female germ cells is mainly adjusted by post-transcriptional regulation of pre-existing maternal mRNA and post-translational modification of proteins. Several key proteins such as the cell cycle regulator, Cdk1/cyclin B, are post-translationally modified for precise control of meiotic progression. The second messenger (cAMP), kinases (PKA, Akt, MAPK, Aurora A, CaMK II, etc), phosphatases (Cdc25, Cdc14), and other proteins (G-protein coupled receptor, phosphodiesterase) are directly or indirectly involved in this process. Many proteins, such as CPEB, maskin, eIF4E, eIF4G, 4E-BP, and 4E-T, post-transcriptionally regulate mRNA via binding to the cap structure at the 5' end of mRNA or its 3' untranslated region (UTR) to generate a closed-loop structure. The 3' UTR of the transcript is also implicated in post-transcriptional regulation through an association with proteins such as CPEB, CPSF, GLD-2, PARN, and Dazl to modulate poly(A) tail length. RNA interfering is a new regulatory mechanism of the amount of mRNA in the mouse oocyte. This review summarizes information about post-transcriptional and post-translational regulation during mouse oocyte meiotic maturation.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.1032-1035
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• 2003

In pseudohypoparathyroidism as reported by Albright in 1942, the parathyroid gland can normally synthesize and secrete parathyroid hormone(PTH). Pseudohypoparathyroidism has a similar biochemical finding with hypoparathyroidisms like hypocalcemia and hyperphosphatemia due to target tissue resistance to PTH. Administered PTH does not raise the serum levels of calcium and urinary phosphate. PTH activates G-protein in peripheral tissue and adenylate cyclase through a second messenger, cAMP. Pseudohypoparathyroidism produces hyperphosphatemia and hypocalcemia because of the resistance to PTH in peripheral tissue due to a defect of G-protein, although it releases PTH normally. According to the mechanism of resistance, pseudohypoparathyroidism is classified into types : Ia, Ib, Ic and psedopseudohypoparathyroism. Type Ia is accompanied by congenital growth retardation and abnormal bony development that shows mental retardation, obesity, low height, round face, short metacarpal bone and metatarsal bone, ectopic calcification, etc. We report a case of pseudohypoparathyroidism in a premature who shows hypocalcemia, hyperphosphatemia, elevation of serum PTH and 24 hr urinary basal c-AMP in biochemical tests without Albright's hereditary osteodystrophy at physical examination, accompanied by a spontaneous fracture in the femur.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.416-430
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• 1996

With the progress of chemical researches in ginseng studies, efforts to elucidate the pharmacological actions of ginseng have been greatly increased. The majority of ginseng reaserches in the past has been performed with crude extracts from ginseng roots to verify scientifically the empirical application of ginseng in men and animals recently. Ginseng reaserches have been done mostly with pure ginsenosides and there has been a shift in focus to the various biochemical pathways. It was demonstvated that ginseng had diverse effects by modulating the second-messenger system, such as cyclic nucleotides. calcium The demonstration in 1987 of the formation of nitric oxide(NO, endothelium-derlled rectating factor) by an enzyme in vascular endothelial cells opened up a new area of biological reaserches of ginseng. It was shown that vascular relaxations induced by glnsenosides are mediated by release of nitric oxide from endothelial cells. According to the literature search from'hledline". There have been 737 original and review articles during the last 30 years. In these review articles, an attempt has been made to summalize some results from some of these published papers. Ginseng has a wide range of phal.macologtcal and therapeutical actions. It acts on the centralral nervous system and cardiovascular system, promotes immune function and metabolism. Possesses anti-stress. Anti-cancer and anti-ageing activities, and so on.o on.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.3
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• pp.147-154
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• 2020

The purpose of this study was to research the status of logistic service-related workers about untact works by case study in the Era of COVID-19. An experimental design was used by case analysis of interviews with ten office workers from May to June 2020. The results of this research were divided into three categories: work environment, work management and work effect. First, teleworking has a significantly positive influence on business efficiency about work environment. ZOOM, One drive, Skype, Chatbot, Microsoft Teams and Remote view are used as collaborative applications. Second, work instructions in documents are needed such as e-mail and messenger using information and communication technology about work management. Third, the strong points of teleworking are both high work efficiency and job satisfaction about work effect. The weak points of teleworking are both very low-technology and misunderstanding about work effect. The result offer some insights into the case study of logistic service-related workers about untact works. Based on the results, the implications and the limitations of this study were discussed.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.103.2-103.2
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• 2003

The hydrolysis of sphingomyelin (SM), known as the SM pathway, is induced by the activation of sphingomyelinase (SMase) to generate the second messenger ceramide, which plays a key role in cellular responses such as apoptosis, differentiation, senescence, and inflammation. Here, we identified a 60 kDa membrane-associated, neutral and Mg$\^$2+/-dependent SMase, termed N-SMase $\varepsilon$, from mammalian brains, which was revealed as the heat shock protein 60 (HSP60) through cDNA cloning and mass spectrometrical analysis. (omitted)

• Asia Marketing Journal
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• v.14 no.2
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• pp.1-22
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• 2012

Gifticon is an innovative new service of SK Marketing & Company. Launched in the end of 2006 for the first time in the world, the mobile gift certificate is in the form of a SMS message that bears a bar code to exchange with real products sent to the intended recipient through internet portal, messenger or/and mobile phones. The service started by connecting individuals (B2C business) and was expanded to the new marketing tools of companies (B2B business). While the business took off with soft progress in the initial year of launch, Gifticon business finally gained its momentum in the growth of sales in its second and third year. Yet, the data showed that the growth of user-base was getting stagnant that the number of users remained flat for the past few months. Moreover, competition from latecomers such as Giftishow from KTF and Heartcon from LG Telecom gets fierce. Particularly in B2B sector where Gifticon has made minimal profit, competitors started aggressive promotional activities, taking away shares from Gifticon. Under these circumstances, team is facing tough strategic decisions for its long-term growth; How can they further grow the business? Should they go after more massive targets for broader user-base? Should they pursue B2B business more aggressively? This case study asks students to come up with solutions for these questions by understanding concepts, theories and models for diffusion of innovations and strategies to overcome a chasm.