• Analytical Science and Technology
• /
• v.23 no.4
• /
• pp.331-346
• /
• 2010

Perfluorinated compounds have characteristics of resistance to heat, acidic, basic conditions and also resist water, oil, grease, pollutant. Futhermore they are used by various industrial material, nowadays, they produced in large scale for indutrial and commercial areas. However, they also resist metabolizing and degrading in environmental system (plant, animal, even human body). Moreover, in animal's bodies, PFCs can be accumulated in organ (eg; liver) and lead to liver cell necrosis even oncogenesis. Perfluorinated compounds are newly registered as new persistent organic pollutants (POPs) on Stockholm convention in 2009. Therefore necessity for analytical methodology for determination of PFCs in various environmental samples is even more increased. This study discussed sample preparation and instrumental conditions for the analysis of PFCs in environmental and biota samples.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.23-23
• /
• 2018

In this study, new titanium alloys were prepared by adding elements such as tantalum (Ta), zirconium (Zr) and the like to complement the biological, chemical and mechanical properties of titanium alloys. The Ti-40Ta-xZr ternary alloy was formed on the basis of Ti-40Ta alloy with the contents of Zr in the contents of 0, 3, 7 and 15 wt. %. Plasma electrolytic oxidation (PEO), which combines high-voltage sparks and electrochemical oxidation, is a novel method to form ceramic coatings on light metals such as Ti and its alloys. These oxide film produced by the electrochemical surface treatment is a thick and uniform porous form. It is also composed of hydroxyapatite and calcium phosphate-based phases, so it has the characteristics of bone inorganic, non-toxic and very high bioactivity and biocompatibility. Ti-40Ta-xZr alloys were homogenized in an Ar atmosphere at $1050^{\circ}C$ for 1 hour and then quenched in ice water. The electrochemical oxide film was applied by using a power supply of 280 V for 3 minutes in 0.15 M calcium acetate monohydrate ($Ca(CH_3COO)_2{\cdot}H_2O$) and 0.02 M calcium glycerophosphate ($C_3H_7CaO_6P$) electrolyte. A small amount of 0.0075M zinc acetate and magnesium acetate were added to the electrolyte to enhance the bioactivity. The mechanical properties of the coated surface of Ti-40Ta-xZr alloys were evaluated by Vickers hardness, roughness test, and elastic modulus using nano-indentation, and the surface wettability was evaluated by measuring the contact angle of the coated surface. In addition, cell activation and differentiation were examined by cell culture of HEK 293 (Human embryonic kidney 293) cell proliferation. Surface properties of the alloys were analyzed by scanning electron microscopy(FE-SEM), EDS, and X-ray diffraction analysis (XRD).

• Journal of Life Science
• /
• v.27 no.5
• /
• pp.579-583
• /
• 2017

Tetragonia tetragonioides seems to be a promising antiulcer medicinal plant due to the presence of water-soluble polysaccharide and cerebroside as its major constituents. There have been no previous studies using T. tetragonioides polysaccharide extract (TPE) to assess its antidiabetic effect in streptozotocin (STZ)-induced diabetes in mice. This study was designed to evaluate the antidiabetic effect of TPE in diabetic mice, which was established by one-week intraperitoneal injection of 65 mg/kg STZ. After three weeks of TPE treatment at a dose of 100 mg/kg, a maintenance of body weight, a decrement in plasma glucose, and low levels of triglyceride, lactate dehydrogenase, alkaline phosphatase, and glutamic pyruvic transaminase were observed in diabetic mice. Furthermore, the ingestion of TPE lowered the blood glucose levels during the oral glucose tolerance test (OGTT) and restored most of the tested parameters to their normal levels. Therefore, the antidiabetic potential of T. tetragonioides has been demonstrated for the first time by our research.

• Korean Chemical Engineering Research
• /
• v.43 no.1
• /
• pp.76-79
• /
• 2005

Dry etching of NiFe, NiFeCo, and Ta for magnetic random access memory (MRAM) by inductively coupled plasmas (ICPs) of $Cl_2/Ar$ has been carried out. NiFe and NiFeCo showed maximum etch rates at a particular ICP source power, but the etch rate of Ta increased with the ICP source power. The etch rates of the magnetic thin films increased with the RF chuck power, but decreased with the operating pressure and the $Cl_2$ concentration. To avoid a corrosion problem by chlorine, the etched samples were rinsed with de-ionized water for 5 minutes after etching. The etch profile showed a clean and smooth surface at 50% $Cl_2$ concentration.

• The Korea Journal of Herbology
• /
• v.26 no.3
• /
• pp.65-73
• /
• 2011

Objectives : The present study was evaluated the protective roles of Spatholobi Caulis in hepatotoxic rats due to APAP overdose. Methods : In experiments, rats were orally administrated with the aqueous extract of Spatholobi Caulis (SCE; 50, 100 mg/kg) for 4 days and then, orally gavage with APAP (1.2 g/kg) to induce acute liver damage. Results : Oral injection of APAP caused severe hepatic injury. Plasma ALT, AST and LDH levels were significantly elevated, but SCE significantly decreased ALT, AST and LDH to the normal level. In histopathological analysis, peripheral hemorrhage around portal triads and central necrosis around central veins were founded after APAP treatment. However, these histopathological changes were recovered by SCE pretreatment. SCE also decreased the percentage of generative hepatic regions (%/$mm^2$ hepatic parenchyma), the numbers of inflammatory cells (cells/$mm^2$ hepatic parenchyma) and the number of degenerative hepatic cells (N/100 hepatic cellls) which were significantly elevated after APAP injection. Furthermore, SCE down-regulated the contents of hepatic MDA and up-regulated hepatic GSH. SCE also inhibited the decrease in the expression of pro-caspase-3 by APAP treatment. Conclusions : Collectively, these data indicate that SCE protected APAP-induced hapatic damages through antioxidative and anti-apoptotic process. These findings the significant therapeutic potential of SCE during APAP-induced liver injury.

• The Korea Journal of Herbology
• /
• v.26 no.4
• /
• pp.139-147
• /
• 2011

Objectives : The aim of this study is to research an anti-thrombus effect by Diospyros Kaki Calyx. Methods : The healthy human plasma were gained and used in vitro study such as factor X activity (FXa) inhibition, prothrombinase inhibition, prothrombin time (PT) and activated partial thromboplastin time. Fifteen SD rats were divided into three groups ; intact control group (orally administrated with distilled water 5ml/kg) and two experimental group treated with extract of diospyros kaki calyx (EKC). Experimental rats were orally 600 mg/kg concentration of EKC and 200 mg/kg concentration of EKC. After an hour from administration, we anesthetized rats and made arteriovenous (AV) shunt rat models to study weight of thrombus, took whole blood to study content of thromboxane B2 and blood clotting time. Results : In vitro, EKC significantly increased inhibitory activity of FXa, prothrombinase compared with intact control group ($^*P$ <0.05). PT and aPTT were increased in EKC treated (600 mg/kg) group compared with intact control group ($^*P$ <0.05). In vivo, blood clotting time of experiment group treated with EKC 600 mg/kg were significantly increased compare with that of intact control group (p<0.05) and content of thromboxane B2 was significantly decreased in group treated with EKC 600 mg/kg in serum. The weight of thrombus were significantly reduced in group treated with EKC 600 mg/kg compared with intact control group (p<0.05). But in vivo experiment study, those parameters of group treated with EKC 200 mg/kg were relatively decreased compared with those of intact control group without statistical significance. Conclusions : EKC has an antithrombic activity because of inhibition internal course such as FXa and prothrombin. And EKC inhibited a hole blood clotting in vivo experiment by low content of thromboxane B2.

• Archives of Pharmacal Research
• /
• v.13 no.2
• /
• pp.151-160
• /
• 1990

In order to develop a controlled-release oral drug delivery system (DDS) which sustains the plasma acetaminophen (AAP) concentration for a certain period of time, microporous membrane-coated tablets were prepared and evaluated in vitro. Firstly, highly water-soluble core tablet of AAP were prepared with various formulations by wet granulation and compression technique. Then the core tablets were coated with polyvinychloride (PVC) in which micronized sucrose particles were dispersed. Effect of formula compositions of core tablets and coating suspensions on the pharmaceutical characteristics such as drug release kinetics and membrane stability of the coated tablets was investigated in vitro. AAP was released from the coated tablets as a zero-order rate in a pH-independent manner. This independency of AAP release to pH change from 1.2 to 7.2 is favorable for the controlled oral drug delivery, since it will produce a constant drug release in the stomach and intestine regardless of the pH change in the GI tract. Drug release could be extended upto 10 h according to the coating condition. The release rate could be controlled by changing the formula compositions of the core tablets and coating suspensions, coat weight per each tablet, and especially PVC/sucrose ratio and particle size of the sucrose in the coating suspension. The coated tablets prepared in this study had a fairly good pharmaceutical characteristics in vitro, however, overall evaluation of the coated tablet should await in vivo absorption study in man.

• Journal of Life Science
• /
• v.21 no.4
• /
• pp.515-520
• /
• 2011

This study was carried out to evaluate the immunomodulatory capacity of edible mushrooms, including Lepista nuda, Corprinis comatus, Letinus edodes, and Pleurotus eryngii, in mice. BALB/c mice were administered 1, 50, and 500 mg/kg body weight of various mushrooms five times a week over 4 weeks through gastric intubation. The control mice were administered distilled water. No significant changes in body weight were observed. IL-4 and IFN${\gamma}$ production was evaluated with splenic T lymphocytes stimulated in vitro with phytohemagglutinins for 48 hr. The mice group administered L. edodes showed significantly higher ratio of IFN${\gamma}$ versus IL-4 than the other groups. In addition, the ratio of plasma IgG2a versus IgG1 was also significantly elevated in mice treated with L. edodes. However, no significant change was observed in ratio of IgG2a versus IgG1 in splenic B lymphocytes stimulated in vitro with lipopolysaccharides for 7 days. These results indicate that L. edodes can enhance type-1 helper T cell-mediated cellular immunity.

• Korean Journal of Medicinal Crop Science
• /
• v.10 no.1
• /
• pp.37-40
• /
• 2002

GABA tea which was increased of GABA by anaerobic conditions in green tea leaves) was fed in the diet to spontaneously hypertensive rats(SHR). The mean systolic blood pressure of SHR fed a diet containing 1.5% GABA tea after 3 weeks was not different with zero day as 177.3mmHg. However, 1.5% green tea and control after 3 weeks were more increased 4.2 percents and 10 percents than in zero day. The plasma levels of aldosterone of SHR fed a diat containing 1.5% GABA green tea after 3 weeks was more decreased 2.5 times than in water treatment.

• Journal of Pharmaceutical Investigation
• /
• v.41 no.3
• /
• pp.173-178
• /
• 2011

Injectable chitosan hydrogels have attracted great potential due to sustained-release property and safety. Here, palmityl-acylated glycol chitosan (Pal-GC) was used to generate physically cross-linked hydrogels by virtue of hydrophobic attraction of linear fatty carbons. Glycol chitosan was chemically modified with N-hydroxysuccinimide-activated palmitic acid in dimethylsulfoxide (DMSO) containing dimethylaminopyridine. Through a series of preparation steps of (i) dialysis with DMSO, (ii) addition of palmityl-acylated exendin-4 (Ex4-C16), and (iii) dialysis with water, Pal-GC was self-assembled to form physically cross-linked hydrogels entrapped with Ex4-C16. The Pal-GC derivative was analyzed by using 1H NMR, and the surface morphology of Pal-GC hydrogels formed was examined by scanning electron microscopy. Also, the hypoglycemic effect induced by Pal-GC hydrogels containing Ex4-C16 (250 nmol/kg) was evaluated in non-fasted type 2 diabetic db/db mice and compared with GC hydrogels containing native Ex4 at the same dose. Results showed that palmityl group was successfully conjugated with the amines of glycol chitosan, and that Pal-GC efficiently generated the hydrogels formation. Moreover, Pal-GC hydrogels containing Ex4-C16 was found to greatly prolong the hypoglycemia duration (~ 4 days). This was due to the dual-functions of the palmityl groups present in both GC and exendin-4 such as hydrophobic attraction and plasma albumin-binding. We consider this new type of self-assembled GC hydrogels loaded with Ex4-C16 would be a promising long-acting sustained-release system with anti-diabetic property.