• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.515-519
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• 1993

The retention behavior of proteins was investigated by using hydrophobic interaction chromatography (HIC), comparing to the results obtained in reversed-phase chromatography (RPC) described in the previous paper. A SynChropak propyl column was employed with 0.05 M phosphate buffer (pH 7.0) containing sodium sulfate. Conformational changes were recognized by examining Z values as a function of sodium sulfate concentration over a range of temperature between 5 and 65$^{\circ}C$. Z values did not change significantly at the range of the temperature showing the consistent ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ values. The sign and the magnitude of ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ of proteins in HIC were compared with those obtained in RPC. The signs of ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ of proteins in HIC were all positive, while those of proteins in RPC were all negative. These results suggested that the retention of proteins in HIC and in RPC were entropy-driven and enthalpy-driven process, respectively. From the two different investigations, it was concluded that the retention mechanism of RPC and HIC was based on the same fundamental principle in which separation is dependent on hydrophobicity, but the retention behavior of the proteins in HIC is clearly different from that observed in RPC.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.389-396
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• 2019

In patients with severely resorbed alveolar bone, it is difficult to gain retention in denture. Lack of retention makes denture unstable and lead to trouble in using denture. Suction denture seals the entire denture border with movable mucosa and this sealing mechanism forms negative pressure beneath the denture and produce higher retention and stability to denture. In this case, 4 edentulous patients visited for lack of retention with dentures. Considering their high expectation with retention, suction denture concept was used to fabricate retentive and stable denture. The purpose of this case report is to compare and analyze the considerations of suction denture restorations in edentulous patients.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.314-328
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• 1995

This study was attempted to investigate the mechanism of retention of sodium and water by naproxen which is a drug among nonsteroidal anti-inflammatory drugs in dogs. Napoxen, when given intravenously in doses ranging from 30 mg to 100 mg/kg, elicited antidiuresis accompanied vath the decrease of osmolar clearance(Cosm) and amounts of sodium excreted in urine(E$_{Na}$), with the increase of sodium reabsorption rate in renal tubule(R$_{Na}$) and ratio of potassium against sodium (K/Na). Naproxen infused into a renal artery in doses ranging from 1.0mg to 3.0mg/kg/min produced both diuretic action in infused kidney and antidiuretic action in control kidney. Naproxen injected into carotid artery in doses ranging from 10.0 mg to 30.0 mg/kg exhibited antidiuretic action. Changes of renal function in the circumstances of above two antidiuresis were the same with aspect of intravenous naproxen. Antidiuretic action of naproxen injected into carotid artery was not affected by renal denervation, was blocked by pretreatment with i.v. arachidonic acid, prostaglandin precursor, or i.v. indomethacin, cyclooxygenase inhibitor. Naproxen injected into carotid artery abolished the diuretic action of i.v. spironolactone, aldosterone antagonist, and i.v. spironolactone blocked the antidiuretic action of naproxen given into carotid artery. The results suggest that naproxen produced antidiuresis, and sodium and water retention through the central system, the mechanism being related to the prostaglandin biosynthetic inhibition and aldostercfne like action.

• YAKHAK HOEJI
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• v.53 no.5
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• pp.281-285
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• 2009

The retention of solutes in reversed-phase high-performance liquid chromatography depends on their hydrophobicity. Although the retention behaviors of alkyl benzenes have been reported so far, quite a few authors have mentioned the retention behavior of alkyl benzenes with plural hydrophobicity parameters. In this sense, we were interested in the retention behaviors of alkyl benzenes having benzene moiety and increasing alkyl chain. In this study, we therefore investigated the retention behavior of alkyl benzenes in reversed-phase high-performance liquid chromatography in order to obtain information concerning the effects of the aromatic moiety and the carbon chain on the retention mechanism by comparing their capacity factor (k') in relation to the carbon chain length. The eluent acetonitrile ($CH_3CN$) showed high selectivity on alkyl benzenes, showing the high difference of capacity factor (${\Delta}log\;k'$) between toluene and octyl benzene. Indeed, the ${\Delta}log\;k'$ of 80% $CH_3CN$ represented 1.42- and 4.25-times longer than 90% MeOH and 60% THF, respectively. The hydrophobicity parameters, van der Waals volume, bond constant, partition constant, $\pi$-energy effect and enthalpy were evaluated with the capacity factor (k') of alkyl benzenes eluted on 80% CH3CN, 90% MeOH and 60% THF, respectively. The best eluent for predicting retention behavior of alkyl benzenes was 90% MeOH ($R^2$ 0.999). The three parameters, van der Waals volume, bond constant and partition constant were well coincident to log k' by increasing alkyl benzenes. However, $\pi$-energy effect and enthalpy were severely disagreeable. Taken together, van der Waals volume, bond constant and partition constant were a reliable parameters to predict the retention behaviors of alkyl benzenes on reversed-phase column.

• BMB Reports
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• v.56 no.9
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• pp.514-519
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• 2023

Methyltransferase-like 3 (METTL3), a key component of the m⁶A methyltransferase complex, regulates the splicing, nuclear transport, stability, and translation of its target genes. However, the mechanism underlying the regulation of METTL3 expression by alternative splicing (AS) remains unknown. We analyzed the expression pattern of METTL3 after AS in human tissues and confirmed the expression of an isoform retaining introns 8 and 9 (METTL3-IR). We confirmed the different intracellular localizations of METTL3-IR and METTL3 proteins using immunofluorescence microscopy. Furthermore, the endogenous expression of METTL3-IR at the protein level was different from that at the mRNA level. We found that 3'-UTR generation by intron retention (IR) inhibited the export of METTL3-IR mRNA to the cytoplasm, which in turn suppressed protein expression. To the best of our knowledge, this is the first study to confirm the regulation of METTL3 gene expression by AS, providing evidence that the suppression of METTL3 protein expression by IR is an integral part of the mechanism by which 3'-UTR generation regulates protein expression via inhibition of RNA export to the cytoplasm.

• Journal of the Korean Chemical Society
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• v.21 no.1
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• pp.16-22
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• 1977

Bimolecular substitution of $Cl^-$ at carbonyl carbon of $CH_3COCl$ has been investigated MO theoretically by calculating energy profiles (EHT) and electronic distribution (CNDO/2) for frontside and backside attacks at several distances of approach. Considerations of other experimental and MO data together with these calculations support the $S_N2-$retention mechanism for the substitution at carbonyl carbon.

• Journal of the Korean Chemical Society
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• v.34 no.1
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• pp.44-50
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• 1990

The liquid chromatographic retention behavior of structural isomers of phenols was investigated by a change of the mobile phase properties. The retention behavior of structural isomer of phenols in reversed phase liquid chromatography was affected by eluent electrolyte added. It can be seen that this behavior is illustrated by a mechanism of Langmuir isotherm and ion exchange between phenolate and the reversed phase coated with ions. The retention behavior was represented as two different areas according to the concentration of the electrolytes. These areas can be explained as counter ion and co-ion effect, respectively. The maximum retention values were dependent not upon the kinds of organic modifier but upon the kinds of electrolyte.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.2
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• pp.229-242
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• 2022

Creating a new retailing environment to meet the seamless experience requirements of consumers is a challenge for Omnichannel-related businesses. Based on the "appraisal-emotion-response" chain, the purpose of this research is to explore the psychological mechanism of omnichannel integration influencing customer retention and the moderating effect of customer showrooming experience. This research uses a structural equation model in partial least square software to analyze a two-stage survey (Study 1: n = 210; Study 2: n = 342) conducted in China. The results show that channel control experience has three dimensions: perceived channel attribute familiarity, channel type matching, and cross-channel access convenience; consistent interactive experience has two dimensions: information cross-channel consistency and cross-channel service support. Furthermore, both channel control experience and consistent interactive experience are favorable for customer retention through increased customer satisfaction (transactional and retailer satisfaction). Finally, customer showrooming experience positively moderates the relationship between consistent interactive experience and customer satisfaction. This research proposes a self-regulation process model to explain how omnichannel integration enhances consumers' experience, finally leading to consumer retention. The findings contribute to the omnichannel retail business literature and provide management implications for Asian retailers to implement an omnichannel business strategy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.837-852
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• 2021

Recurrent neural network (RNN) architectures have been used for language modeling (LM) tasks that require learning long-range word or character sequences. However, the RNN architecture is still suffered from unstable gradients on long-range sequences. To address the issue of long-range sequences, an attention mechanism has been used, showing state-of-the-art (SOTA) performance in all LM tasks. A differentiable neural computer (DNC) is a deep learning architecture using an attention mechanism. The DNC architecture is a neural network augmented with a content-addressable external memory. However, in the write operation, some information unrelated to the input word remains in memory. Moreover, DNCs have been found to perform poorly with low numbers of weight parameters. Therefore, we propose a robust memory deallocation method using a limited retention vector. The limited retention vector determines whether the network increases or decreases its usage of information in external memory according to a threshold. We experimentally evaluate the robustness of a DNC implementing the proposed approach according to the size of the controller and external memory on the enwik8 LM task. When we decreased the number of weight parameters by 32.47%, the proposed DNC showed a low bits-per-character (BPC) degradation of 4.30%, demonstrating the effectiveness of our approach in language modeling tasks.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.4 s.107
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• pp.25-32
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• 2004

Flocculation of fibers and its distribution in paper are related to flocculation mechanisms, retention and drainage. Relationship between flocculation mechanisms and physical properties of paper has not been fully studied. In this study, flocculation of fibers was investigated by changing microparticles for flocculation mechanism analysis. When fillers were not added, formation and strength were deteriorated by 100, 300, or 500 ppm of linear PAM (all L-PAM), All L-PAM + 1200 ppm inorganic microparticle (1200-IM), all L-PAM + 120 ppm organic microparticle (120-OM), all L-PAM + 1200 ppm organic microparticle (1200-OM) because of too much flocculation. When 5, 15, $25\%$ (od.w/w) fillers were added, retention and drainage process were not affected by the extent flocculation when 500 ppm L - PAM, 500 ppm L - PAM + 1200- IM, and 500 ppm L - PAM + 120 ppm OM were added.