• Bulletin of the Korean Chemical Society
• /
• v.11 no.4
• /
• pp.309-313
• /
• 1990

The rates of solvolysis of trans-$[Co(N-eten)_2Cl_2)$+ (N-eten; N-ethylethylenediamine) have been investigated using spectrophotometric method in binary aqueous mixtures containing methyl alcohol, isopropyl alcohol, t-butyl alcohol, ethylene glycol and glycerol. The values of ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$ obtained from temperature effect on the rate constants were $80{\sim}84 kJmol^{-1}$ and $- 28{\sim} - 45 JK^{-1}mol^{-1}.$ Extrema found in the variation of the enthalpy and entropy of activation with solvent composition correlated very well with extrema in the variation of the physical properties of mixture which relate to sharp change in the solvent structure. The reaction mechanism was discussed in terms of correlation diagrams involving the exess molar Gibbs function of mixing for the binary mixtures. The behavior of this cobalt(Ⅲ) complex was compared with that of t-butyl chloride. The application of free energy cycle to the process initial state to transition state in water and in the mixture showed that the solvation of transition state had dominant effect on the rates in the mixtures. It was found that $S_N1$ character was increased with increasing the content of co-solvent in the mixture.

• Food Science of Animal Resources
• /
• v.31 no.4
• /
• pp.580-587
• /
• 2011

In this study, the effects of gamma-irradiation (1, 2 and 4 kGy) on texture profiles, fatty acid composition, free amino acids and sensory evaluation of dry-fermented sausage were evaluated. The hardness and adhesiveness of irradiated samples were significantly lower (p<0.01) than that of the control, while the gumminess of samples irradiated with 2 and 4 kGy was higher than the other tested samples (p<0.01). The sample irradiated at 4 kGy had a higher saturated fatty acid (SFA) content (C14:0, C16:0, C18:0) and significantly lower (p<0.05) unsaturated fatty acid content (UFA) (C16:1, C18:1, C18:3), trans, n-3 and n-6 fatty acid than the non-irradiated sample. Gamma-irradiation resulted in an increase (p<0.05) in phosposerine, aspartic acid and glutamic acid and a decrease (p<0.05) in glutamic acid in free amino acids. For the samples irradiated at 4 kGy, the sulfur odor and fat pungent flavor were significantly higher (p<0.05) and the moldy odor and moldy flavor were significantly lower than the control sample. In conclusion, gamma-irradiation had a significant effect on the texture profiles, fatty acid composition and sensory evaluation of dry-fermented sausage.

• Journal of the Korean Arthroscopy Society
• /
• v.10 no.2
• /
• pp.203-208
• /
• 2006

Purpose: Previous transtibial double bundle posterior cruciate ligament (PCL) reconstruction methods have several problems in graft length and tibial fixation. We introduce new surgical method that is less restrictive by graft length and is more stable with single tibial fixation. Operative technique: After diagnostic arthroscopy, we prepare the graft, ream the tibial tunnel and perform the procedure for TransFix tibial fixation. Femoral 2 tunnel is made and graft is passed via anteromedial (AM) portal. Tibial fixation is done and femoral 2 graft is fixed sequentially at each knee position. Conclusion: TtransFix tibial single fixation method in double bundle PCL reconstruction provides more stable fixation, more free graft selection and prevents graft damage by passing the graft via AM portal.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.6
• /
• pp.1126-1133
• /
• 2002

Conjugated linoleic acid (CLA) is a collective term for a class of positional and geometric conjugated dienoic isomers of linoleic acid (LA) and has anti-cancer activity in experimental animals. We have previously observed that an isomeric mixture of CLA and trans-10,cis-12 (t10c12) inhibited cell growth in a dose-dependent manner whereas LA and cis-9,trans-11 (c9t11) had no effect. The present study examined whether the CLA mixture and t10c12 induce apoptotic cell death. TSU-Prl cells were incubated for three days in serum-free medium in the absence or presence of individual fatty acids, and the DNA fragmentation assay was performed. Cells treated with the CLA mixture or t10c12 produced a distinct oligonucleosomal ladder with different sizes of DNA fragments, a typical characteristic of cells undergoing apoptosis. By contrast, LA and c9t11 had no effect. Western immunoblot analysis of total lysates revealed that t10c12 reduced anti-apoptotic, 26 kDa, Bcl-2 protein levels by 49$\pm$8% compared with controls, whereas this CLA isomer did not alter pro-apoptotic,21 kDa, Bax protein levels. These results suggest that growth inhibitory effect of the t10c12 CLA isomer may, at least in part, be attributed to Increased apoptotic death in TSU-Prl cells.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.6
• /
• pp.752-760
• /
• 2008

Scale-up production of low-trans fat containing conjugated linoleic acid (CLA-TFO) was performed through lipase-catalyzed synthesis. Blend of fully hydrogenated soybean oil, olive oil containing conjugated linoleic acid and palm oil with 1:2:7 ratio was interesterified through Lipozyme RM IM in the 1 L-batch type reactor at $65^{\circ}C$ for 12 hrs, and the physicochemical and melting properties of CLA-TFO were compared with conventional (high trans fat) or commercial low-trans fat shortening. The trans fatty acids content in the conventional shortening (48.8 area%) was much higher than that of low-trans shortening (0.4 area%) and CLA-TFO (0.3 area%+CLA; 7.6 area%). Acid, saponification and iodine values of CLA-TFO were 0.4, 173.9 and 59.0, respectively. Their ${\alpha}$-, ${\gamma}$-tocopherol contents showed 4.7, 1.0 mg/100 g. Differences were observed in the solid fat contents (SFC), melting point of the conventional or low-trans fat and CLA-TFO. Each SFC of conventional, low-trans fat and CLA-TFO was 32.0, 29.3 and 30.4% with melting point of 38.5, 43.0 and $39.5^{\circ}C$ at $35^{\circ}C$, respectively. In texture profile analysis, hardness of conventional, low-trans fat and CLA-TFO was 111.7, 75.2 and 63.8 g.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.2
• /
• pp.146-153
• /
• 1998

NC machines with 4 or 5 axes are capable of various tool approach motions, which makes interference-free and high machinablity machining possible. This paper deals with how to integrate these two advantages (interference-free and high machinability machining) in multi-axes NC machining with a ball-end mill. Feasible tool approach region at a point on a surface is first computed, then among which an approach direction is determined so as to minimize the cutting force required. Tool and spindle volumes are considered in computing the feasible tool approach region, and the computing time is improved by trans-forming surface patches into minimal enclosing spheres. A cutting force prediction model is used for estimating the cutting force. The algorithm is developed so as to be applied to 4- or 5-axes NC machining in common.

• Journal of Veterinary Clinics
• /
• v.28 no.2
• /
• pp.240-243
• /
• 2011

Several vascular accesses can be used for catheter guided coil embolization for occluding patent ductus arteriosus (PDA). Although trans-femoral approach is most commonly used in dogs, it is often unable to insert angiocatheter for inserting the coil delivery system, especially small puppies weighing less than 2 kg of body weight. Therefore this case study developed trans-carotid method for puppy using JR coronary catheter and free push delivery system. Using this new method, we successfully treated a puppy with PDA weighing 1.25 of body weight.

• Macromolecular Research
• /
• v.16 no.8
• /
• pp.717-724
• /
• 2008

In this study, we prepared all-trans retinoic acid (ATRA)-encapsulated, surfactant-free, PLGA nanoparticles. The nanoparticles were formed by nanoprecipitation process, after which the solvent was removed by solvent evaporation or dialysis method. When a nanoparticle was prepared by the nanoprecipitation - solvent evaporation method, the nanoparticles were bigger than the nanoparticles of the nanoprecipitation - dialysis method, despite the higher although loading efficiency. Nanoparticles from the nanoprecipitation - dialysis method were smaller than 200 nm in diameter, while the loading efficiency was not significantly changed. Especially, nanoparticles prepared from DMAc, 1,4-dioxane, and DMF had a diameter of less than 100 nm. In the transmission electron microscopy (TEM) observations, all of the nanoparticles showed spherical shapes. The loading efficiency of ATRA was higher than 90% (w/w) at all formulations with exception of THF. The drug content was increased with increasing drug-feeding amount while the loading efficiency was decreased. In the drug release study, an initial burst was observed for $2{\sim}6$ days according to the variations of the formulation, after which the drug was continuously released over one month. Nanoparticles from the nanoprecipitation - dialysis method showed faster drug release than those from the nanoprecipitation - solvent evaporation method. The decreased drug release kinetics was observed at lower drug contents. In the tumor cell cytotoxicity test, ATRA-encapsulated, surfactant-free, PLGA nanoparticles exhibited similar cytotoxicity with that of ATRA itself.

• International Commerce and Information Review
• /
• v.15 no.1
• /
• pp.309-330
• /
• 2013

Trans-Pacific Partnership started as a small scale 4 countries regional trade agreement. It became a grand free trade agreement when the United States announced its participation and Japn considers to join. Korea still hasn't decided the stance however, considering the economic and political relationship with the United States and the impact of TPP, it looks like that Korea is going to join TPP. US led the TPP agreement is expected to be made based on the previous FTA agreements of the US. In the promising E-Commerce part, it is likely that the e-commerce leading US would suggest favorable agreement. If Korea joins the TPP, it's necessary to suggest what Korea wants and needs based on the previous KORUS FTA to promote Korean e-commerce for the future.

• Korean Journal of Radiology
• /
• v.22 no.1
• /
• pp.118-130
• /
• 2021

Objective: This study aimed to investigate the blood-brain barrier (BBB) disruption in mild traumatic brain injury (mTBI) patients with post-concussion syndrome (PCS) using dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and automatic whole brain segmentation. Materials and Methods: Forty-two consecutive mTBI patients with PCS who had undergone post-traumatic MR imaging, including DCE MR imaging, between October 2016 and April 2018, and 29 controls with DCE MR imaging were included in this retrospective study. After performing three-dimensional T1-based brain segmentation with FreeSurfer software (Laboratory for Computational Neuroimaging), the mean K^trans and v_p from DCE MR imaging (derived using the Patlak model and extended Tofts and Kermode model) were analyzed in the bilateral cerebral/cerebellar cortex, bilateral cerebral/cerebellar white matter (WM), and brainstem. K^trans values of the mTBI patients and controls were calculated using both models to identify the model that better reflected the increased permeability owing to mTBI (tendency toward higher K^trans values in mTBI patients than in controls). The Mann-Whitney U test and Spearman rank correlation test were performed to compare the mean K^trans and v_p between the two groups and correlate K^trans and v_p with neuropsychological tests for mTBI patients. Results: Increased permeability owing to mTBI was observed in the Patlak model but not in the extended Tofts and Kermode model. In the Patlak model, the mean K^trans in the bilateral cerebral cortex was significantly higher in mTBI patients than in controls (p = 0.042). The mean v_p values in the bilateral cerebellar WM and brainstem were significantly lower in mTBI patients than in controls (p = 0.009 and p = 0.011, respectively). The mean K^trans of the bilateral cerebral cortex was significantly higher in patients with atypical performance in the auditory continuous performance test (commission errors) than in average or good performers (p = 0.041). Conclusion: BBB disruption, as reflected by the increased K^trans and decreased v_p values from the Patlak model, was observed throughout the bilateral cerebral cortex, bilateral cerebellar WM, and brainstem in mTBI patients with PCS.