• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.249-253
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• 2001

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium ${\alpha}-sulfonated$ dodecanoyl ethyl esther (${\alpha}-SR_{12}Et$) or sodium dodecyl sulfate(SDS)-polyoxyethylene 23 lauryl ether (Brij 35) un water and in 0.1M sodium chloride solution at $25^{\circ}C$. This technique applies the Gibbs-Duhem equation to the mixed micelles, which is treated as a pseudophase. This proposed methodology, which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.83-88
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• 2010

The composite electroplating is accomplished by adding inert materials during the electroplating. Permalloy is the term for Ni-Fe alloy and it is used for industrial applications due to its high magnetic permeability. Microhardness for microdevices is enhanced after composite coating and it increases the life cycle. However, the hydroxyl group on the silica makes their surface susceptible to moisture and it causes the silica nanoparticles to be agglomerated in the aqueous solution. The agglomeration problem causes poor dispersion which eventually interrupts uniform deposition of silica nanoparticles. In this study, the dispersion of silica nanoparticles in the permalloy electroplated layer is reported with variation of additives and sonication time. Longer sonication period guaranteed better silica nanopowder dispersion and sonication period also influenced on composition of deposits. The amount of silica nanopowder codeposition and surface morphologies were influenced with variation of additives. In alkaline bath, smooth surface morphology and relatively high contents of silica nanopowder codeposition were obtained with addition of sodium lauryl sulfate.

• Toxicological Research
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• v.19 no.2
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• pp.133-139
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• 2003

Allergic contact dermatitis may be caused by a wide variety of chemicals. A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pig models for assessing the contact sensitization potential of chemical. However, there is a need to develop a nonradioisotopic endpoint for the LLNA, because of the radioisotopic method's requiring the use of special facilities. In this study, we investigated the development of a nonradioisotopic endpoint for LLNA using ELISA (enzyme-linked immunosorbent assay). Female Balb/c mice were treated by the topical application on the dorsum of both ears with four different strong sensitizers, 2,4-dinitrochlorobenzene (DNCB), oxazolone (OXZ), toluene diisocyanate (TDI), and trimellitic anhydride (TMA), and a strong irritant, sodium lauryl sulfate (SLS), once daily for three consecutive days. The proliferation of cells in the auricular Iymph node was analyzed by means of the labelling index (Ll) of bromodeoxyuridine (BrdU) incorporation into cells. The weights of the Iymph nodes in the mice treated with allergens, DNCB, OXZ, TDl and TMA were increased compared to the vehicle control. The stimulation index (Sl) of mice treated with DNCB, OXZ, TDl, and TMA was over three-fold increase compared to the vehicle control. However, the S1 of mice exposed to SLS was not significantly increased compared to the vehicle control, while the lymph node weight of SLS was significantly increased. These results suggest that the LLNA modified endpoint using ELISA based on BrdU incorporation could provide a useful method of screening for irritants and allergens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2935-2941
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• 2010

This study used 3 kinds of experimental toothpaste with different contents(0%, 1.1%,2.2% of SLS. A total of 150 young adults in their 20's without any systemic disease were recruited for the study. These 150 subjects were subdivided into three groups(each having 50 subjects) according to the results of preliminary oral examination.After 4 weeks application of the three groups of toothpaste, Group C showed the highest halitosis index, followed by Groups A and B which had similar halitosis indices. Both oral sulfur compound and aerobic sulfur compound were measured at high content possibly because higher SLS content which is associated with the lower salivary flow rate is causing the xerostomia. SLS content was correlated with oral sulfur compound (r=0.412) and aerobic sulfur compound (r=0.285).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.193-202
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• 2009

This study was done to assess an alternative method as a replacement of in vivo phototoxicity test. The human fibroblasts were exposed to several phototoxic chemicals (promethazine, chlorpromazine chlortetracycline, 8-methoxypsoralen, neutral red, bithionol) and non-phototoxic materials (cinnamic aldehyde, p-aminobenzoic acid, sodium lauryl sulfate, L-cysteine). The cell viability was measured by neutral red uptake (NRU) assay. The results of the NRU phototoxicity (PT) assay showed a close agreement with in vivo test except bithionol. We also have tested the cosmetic ingredients including $Medimin^{(R)}$ A, $Medimin^{(R)}$ D, $LG^{(R)}$ 106W, $Phytoclear^{(R)}$ EL-1, Carex humilis L. extract, Canna indica L. extract, Salvia miltiorrhira Bunge extract, $Parsol^{(R)}$ MCX and $Parsol^{(R)}$ 1789. Most materials except Salvia miltiorrhira Bunge extract did not show any phototoxicity.

• Journal of Pharmaceutical Investigation
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• v.34 no.3
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• pp.185-192
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• 2004

The objective of this study was to evaluate the effects of surfactant type and concentration upon dissolution rates of carbamazepine from an immediate-release tablet. The dissolution media used in this study were aqueous solutions containing 0.1-2% sodium lauryl sulfate, cetyltrimethylammonium bromide, or polysorbate 80. The solubility of carbamazepine in the dissolution media was determined at first. A dissolution study was then conducted by using the USP dissolution apparatus II (paddle method) with an agitation rate of 75 rpm. Aliquots of the dissolution media were taken at predetermined time intervals, and the amount of carbamazepine dissolved was measured spectrophotometrically at 285 nm. The dissolution data obtained were fitted into a biphasic exponential equation with four parameters. Excellent correlations were observed between the experimental data and the theoretical ones predicted by the equation. This equation permitted the calculation of $T_{50%}$ (the time required for dissolving 50% of carbamazepine) under various experimental conditions. Differentiation of the equation also led to the attainment of dissolution rates at dissolution time points. The addition of a surfactant to an aqueous solution led to increasing the solubility of carbamazepine by 3- to 12-folds, depending upon its type and concentration. This event also resulted in enhancing the magnitude of a sink condition during the dissolution study. As a result, the dissolution rate of carbamazepine was affected by the aqueous surfactant concentration in a proportional manner. Subsequently, $T_{50%}$ values declined rapidly, as the surfactant concentration increased. Such effects were observed in decreasing order of sodium lauryl sulfate, cetyltirmethylammonium bromide, and polysorbate 80. These results clearly demonstrated that it was possible to tailor a dissolution rate and $T_{50%}$ of carbamazepine by manipulating the type and concentration of a surfactant. Relevant information would be beneficial to setting up dissolution specifications for poorly water-soluble drug products.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.879-883
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• 2006

To develop a $^{13}C-urea-containing$ capsule for more economic and sensitive diagnosis of Helicobacter pylori infection, the $^{13}C-urea-containing$ capsules were prepared with various additives such as polyethylene glycol, microcrystalline cellulose, sodium lauryl sulfate and citric acid. Their dissolution test and $^{13}C-urea$ Breath Test in human volunteers were then performed. Polyethylene glycol increased the initial dissolution rates of urea and difference ${\sigma}$ $^{13}C$ values from $^{13}C-urea$, while microcrystalline cellulose and sodium lauryl sulfate decreased them. Irrespective of addition of citric acid, the compositions with polyethylene glycol showed higher values from $^{13}C-urea$ compared to a commercial 76 mg $^{13}C-urea-containing$ capsule due to higher initial dissolution rate. The capsules with 38 mg $^{13}C-urea$ and 1.9 mg polyethylene glycol, which showed higher Helicobacter pylori-positive value of about $8{\textperthousand}$ at 10 min, improved the sensitivity of $^{13}C-urea$ in human volunteers. Thus, the $^{13}C-urea-containing$ capsule with polyethylene glycol would be a more economical and sensitive preparation for diagnosis of Helicobacter pylori infection.

• Resources Recycling
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• v.2 no.2
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• pp.1-8
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• 1993

This study was carried out in order to define the effective collectors and the opitimum conditions for the removal of iron ion in waste water by flotation method. The results obtained in this study are summarized as follows. Fe(II) and Fe(III) were removed effectively at pH7 and 6 respectively by using sodium lauryl sulfate, an anionic collector. The anionic collector, aeropromotor 845, removed both Fe(II) and Fe(III) effectively in pH ranges of from 5 to 9. The cationic collector, trimetyl dodecyl ammonium chloride, removed both Fe(II) and Fe(III) effectively in pH ranges from 10 to 11 and from 4 to 10, respectively. Therefore, Fe(II) and Fe(III) could be effectively removed by forming the iron hydroxide precipitates by simple pH adjustment of the solutions above precipitation point of ferrous and ferric ion by flotation method. Then, the effective pH regulator and collector were NaOH and $Na_2CO_3$,aeropromotor 845 and trimetyl dodecyl ammonium chloride, respectively.

• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.186-194
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• 1988

The electrochemical reduction of O,O-dimethyl-O-(3-methyl-4-nitrophenyl)-phosphorothioate (Fenitrothion) has been studied in acetonitrile solution containing surfactant micelle by direct current (DC)-differential pulse (DP) polarography, cyclic voltammetry (CV) and controlled potential coulometry (CPC). The partially reversible electron transfer-chemical reaction(EC, EC mechanism) of fenitrothion reduction proceeded by four electron transfer to form O,O-dimethyl-O-(3-methyl-4-hydroxyaminophenyl)-phosphorothioate which undergoes single bond of the phosphorus atom and phenoxy group cleaves to give p-amino-m-cresol and dimethyl thiophosphinic acid as major product by two electron transfer-protonation at higher negative potential. The polarograpic reduction waves shown to suppressed due to inhibitory effect of sodium lauryl sulfate micelle solution and split up on selectivity of anionic micelle effect in two step at the first reduction peak.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.70-77
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• 1991

1-Benzyl-4-iodomethyl-2-azetidinone(BIMA) was synthesized and its electrochemical reduction was investigated by direct current, differential pulse polarography, cyclic voltammetry and controlled potential coulometry. The irreversible two electron transfer on reductive dehalogenation of iodo group proceeded to form 1-benzyl-4-methyl-2-azetidinone by EEC electrode reaction mechanism at the first reduction step(-1.35 volts vs. Ag-AgCl). The polarographic reduction waves separated into two reduction steps due to anionic surfactant (sodium lauryl sulfate) effects, while the waves were shifted to the positive potential as the concentration of cationic surfactant (cetyltrimethylammonium bromide) increased. Upon the basis of results on the product analysis and interpretation of polarogram with pH variable, EEC electrochemical reaction mechanism was suggested.