• Korean Chemical Engineering Research
• /
• v.58 no.2
• /
• pp.176-183
• /
• 2020

In this study, synthesis of a hydrogel consisted of a coordination bond network between small organic molecules and transition metals had been carried out. By adding a tackifying material to the gel, the potential of the gel to be used as an adhesive material had been also confirmed. Synthesis of the adhesive had been done with simple mixing of 3 components: tannic acid, transition metal, and polymer. The tannic acid molecule possesses multiple hydroxyl groups that can form coordination bonds with the transition metals and hydrogen bonds with the hydrophilic polymers. Due to the morphology of the metal-organic complex and polymer dispersed in water, the fabricated material exhibited high adhesiveness and cohesiveness. Optimizing the rheological property had been conducted for use in adhesive by the synthesis with varying the transition metal (Fe³⁺, Ti⁴⁺), polymer, and treatment conditions. Rheological measurement results demonstrate the promising potential of the material as a bio-compatible and versatile pressure-sensitive adhesive with both high adhesiveness and cohesiveness.

• The Journal of Churna Manual Medicine for Spine and Nerves
• /
• v.6 no.2
• /
• pp.61-70
• /
• 2011

Objectives : The purpose of this study was to investigate the effect of Bee-venom acupuncture on low back pain by traffic accidents. Methods : We included 34 patients with low back pain caused by TA for this study. The experimental group was treated by usual therapy plus Bee-venom acupuncture therapy, the control group was treated by usual therapy such as acupunture therapy and herbal medicine therapy. Oswestry Disability Index(ODI) and Visual Analog Scale(VAS) were evaluated at 4 week from baseline for the treatment effect in the both group. Results : After the subjects being treated by Bee-venom or general acupuncture therapy. It was detected that the scores of ODI and VAS in both groups decreased at the 4 week from baseline. There was significant difference between both groups in the VAS. However, there was no significant difference between both groups in the ODI. Conclusions : The results suggested that bee-venom acupuncture was effective on low back pain by traffic accidents.

• Journal of Veterinary Clinics
• /
• v.28 no.2
• /
• pp.262-266
• /
• 2011

A 4-year-old intact male, Maltese dog weighing 2.2 kg was presented for evaluation of tachypnea and hyperthermia. On initial evaluation, the dog was dyspneic, but alert and responsive. Muffled heart sound was noted with auscultation of the right hemithorax. The radiographic findings were consolidation of the right middle lung lobe, pleural effusion, and abdominal fluid accumulation. Thoracic computed tomography confirmed a contrast-enhancing mass within the right middle lung lobe. Surgical exploration of the thoracic cavity was performed using a right fifth intercostal thoracotomy. Examination of the right lung lobe revealed $360^{\circ}C$ torsion of the right middle lung lobe at the level of the hilus, in a clockwise direction. Lung lobectomy was performed using a thoracoabdominal stapling device with 2.5-mm vascular staples. Full-thickness intestinal biopsy by exploratory laparotomy was taken from the jejunum for histological assessment. Histopathologic examination of the full-thickness intestinal biopsy revealed distended lacteal located within the submucosa of the jejunum. Intestinal lymphangiectasia was resolved with prednisone and low fat diets. Subsequent communication with the owner revealed that the patient was in good health 6 months post-discharge.

• Korean Journal of Materials Research
• /
• v.22 no.5
• /
• pp.243-248
• /
• 2012

ZrN nanoparticles were prepared by an exothermic reduction of $ZrCl_4$ with $NaN_3$ in the presence of NaCl flux in a nitrogen atmosphere. Using a solid-state combustion approach, we have demonstrated that the zirconium nitride nanoparticles synthesis process can be completed in only several minutes compared with a few hours for previous synthesis approaches. The chemistry of the combustion process is not complex and is based on a metathesis reaction between $ZrCl_4$ and $NaN_3$. Because of the low melting and boiling points of the raw materials it was possible to synthesize the ZrN phase at low combustion temperatures. It was shown that the combustion temperature and the size of the particles can be readily controlled by tuning the concentration of the NaCl flux. The results show that an increase in the NaCl concentration (from 2 to 13 M) results in a temperature decrease from 1280 to $750^{\circ}C$. ZrN nanoparticles have a high surface area (50-70 $m^2/g$), narrow pore size distribution, and nano-particle size between 10 and 30 nm. The activation energy, which can be extracted from the experimental combustion temperature data, is: E = 20 kcal/mol. The method reported here is self-sustaining, rapid, and can be scaled up for a large scale production of a transition metal nitride nanoparticle system (TiN, TaN, HfN, etc.) with suitable halide salts and alkali metal azide.

• The Journal of the Korean Society for Microbiology
• /
• v.18 no.1
• /
• pp.53-58
• /
• 1983

Enterotoxigenic E. coli is one of causative agents of the infantile diarrhea and traveler's diarrhea. A modified infant mouse assay(IMA) was developed for the detection of heat stable enterotoxin (ST) of E. coli isolated from diarrheal and control infants and assay system was established with using enterotoxin producing reference strains. The supernatant of the 24 hour-shaking culture of E. coli in Casamino Acid Yeast Extract Salt Broth(CYES-2) was ingested orally into the 2-4 day old ICR mice. After the mice were kept at $25^{\circ}C$ for 4 hours, they were sacrificed and the gut weight body weight ratio(GW/BW) was taken as the index of fluid accumulation induced by heat stable enterotoxin of E. coli. The results obtained were as follows; 1. The GW/BW responses of IMA tested with enterotoxin reference strains of E. coli(E. coli O148H28:$ST^+LT^+$, E. coli $O78H^-:ST^+LT^+$, E. coli O15H11:$ST^-LT^+$, E. coli O1H7:$ST^-LT^-$) appeared ta be ST dose-dependent, and not LT-dependent. From the dose-response curve, $25{\mu}l$ of culture supernatant was determined as test amount of the IMA. 2. Frequency distribution of IMA result from 643 strain of E. coli showed normal distribution at low GW/BW ratio and dispersed pattern at high GW/BW ratio. The GW/BW ratios of $0.056{\pm}0.004(mean{\pm}SD)$ of normal distribution which distributed from 0.044 to 0.068(P<0.01) was considered as ST negative. Thus the GW/BW ratio above 0.069 could be regarded as ST positive.

• Food Science and Biotechnology
• /
• v.16 no.2
• /
• pp.285-289
• /
• 2007

A 3% suspension of heat-stabilized defatted rice bran was treated with papain, followed by inactivating the enzyme by heat, and centrifuged. The supernatant was subjected to ultrafiltration, and fractions with various molecular sizes, F1 (>30 kDa), F2 (10-30 kDa), F3 (5-10 kDa), F4 (3-5 kDa), and F5 (3 kDa<), were freeze-dried, and evaluated for antimutagenicity by Ames test using Salmonella typhimurium TA 100 against phenazine methosulfate. The F3 fraction containing highest antimutagenicity from ultrafiltration was separated into 6 fractions by DEAE-Sephadex A-25 ion-exchange column chromatography (F3-1-F3-6). Each fractions having protein contents were pooled, dialyzed, freeze dried, and evaluated for antimutagenicity. Among the six fractions, the F3-1, F3-2, and F3-6 fractions showed antimutagenicity, which were 80.2, 53.4, and 58.6% at concentration of $100\;{\mu}g/plate$, respectively. These F3-1, F3-2, and F3-6 fractions were subjected to Sephadex G-50 gel filtration column chromatography for further purification. Among the purified fractions, the F3-1-1, F3-2-2, and F3-6-1 fractions showed antimutagenicity of 84.5, 58.6, and 69.8% at concentration of $100\;{\mu}g/plate$, respectively. It is thought that these peptides can find application for nutraceutical and pharmaceutical products.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.7 no.4
• /
• pp.289-295
• /
• 2005

This paper reports on the dendrochronological investigation of tree ring growth of Pinus densiflora in the Gyeongbuk region. Tree ring growth was analysed using basic statistical value and correlation analysis to evaluate the relative contribution of climatic factors. Ta extract age-related trends and nonclimatic signals, each measurement series was standardized using a negative exponential growth function. In the Gyeongbuk region, tree ring growth was positively correlated with the current year in February, March and April, January, February, and March precipitation showed a positive correlation with the current growth year. This suggests that climatic factors (monthly average temperature, precipitation) limit breaking of dormancy and promotion of growth of Pinus densiflora in the Gyeongbuk region.

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2002.11a
• /
• pp.42-43
• /
• 2002

반도체 디바이스의 발전은 높은 직접화 및 동작 속도를 추구하고 있으며, 이를 위해서 MOSFET의 scale down시 발생되는 문제를 해결해야만 한다. 특히, Channel이 짧아짐으로써 발생하는 device의 열화현상으로 동작전압의 조절이 어려워 짐을 해결해야만 하며, gate oxide 두께를 줄임으로써 억제할 수 있다고 알려져 왔다. 현재, gate oxide으로 사용되고 있는 SiO2박막은 비정질로써 ～8.7 eV의 높은 band gap과 Si기판 위에서 성장이 용이하며 안정하다는 장점이 있으나, 두께가 1.6 nm 이하로 얇아질 경우 전자의 direct Tunneling에 의한 leakage current 증가와 gate impurity인 Boron의 channel로의 확산, 그리고 poly Si gate의 depletion effect[1,2] 등의 문제점으로 더 이상 사용할 수 없게 된다. 2001년 ITRS에 의하면 ASIC제품의 경우 2004년부터 0.9～l.4 nm 이하의 EOT가 요구된다고 발표하였다. 따라서, gate oxide의 물리적인 두께를 증가시켜 전자의 Tunneling을 억제하는 동시에 유전막에 걸리는 capacitance를 크게 할 수 있다는 측면에서 high-k 재료를 적용하기 위한 연구가 진행되고 있다[3]. High-k 재료로 가능성 있는 절연체들로는 A1₂O₃, Y₂O₃, CeO₂, Ta₂O, TiO₂, HfO₂, ZrO₂,STO 그리고 BST등이 있으며, 이들 재료 중 gate oxide에 적용하기 위해 크게 두 가지 측면에서 고려해야 하는데, 첫째, Si과 열역학적으로 안정하여 후속 열처리 공정에서 계면층 형성을 배제하여야 하며 둘째, 일반적으로 high-k 재료들은 유전상수에 반비례하는 band gap을 갖는 것으로 알려줘 있는데 이 Barrier Height에 지수적으로 의존하는 leakage current때문에 절연체의 band gap이 낮아서는 안 된다는 점이다. 최근 20이상의 유전상수와 ～5 eV 이상의 Band Gap을 가지며 Si기판과 열역학적으로 안정한 ZrO₂[4], HfiO₂[5]가 관심을 끌고 있다. HfO₂은 ～30의 고유전상수, ～5.7 eV의 높은 band gap, 실리콘 기판과의 열역학적 안전성 그리고 poly-Si와 호환성등의 장점으로 최근 많이 연구가 진행되고 있다. 또한, Hf은 SiO₂를 환원시켜 HfO₂가 될 수 있으며, 다른 silicide와 다르게 Hf silicide는 쉽게 산화될 수 있는 점이 보고되고 있다.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.2
• /
• pp.257-264
• /
• 2009

The purpose of this study was to investigate the lower extremity kinematics and muscle activities of adductor longus(AL), gluteus medius(GME), gluteus maximus(GMA), biceps femoris(BF), rectus femoris(RF), gastrocnemius(GA), and tibialis anterior(TA) using three dimensional and Noraxon 8 channels EMG system during turn 0, 60, 90 and 120 degrees in patients with Parkinson's disease. Seven parkinson's patients and five healthy subjects were participated in the study. Participants with Parkinson's disease demonstrated significant differences in reduction of stride length and stride width. Also, they showed ill difference in muscle activities. The strength and balance of the lower extremity muscles may help to improve cutting movement and to prevent falling in parkinson's patients.

• Korean journal of food and cookery science
• /
• v.24 no.1
• /
• pp.46-51
• /
• 2008

In this study, the antioxidant and antimutagenic activities of Cuscutae semen ethanol extract were evaluated. Antioxidant activity was measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the Ames test was employed to determine the inhibition effect on mutagenicity in Salmonella typhimurium TA100. The extract showed significant free radical-scavenging activity towards the DPPH radical, and at a concentration of 400 ppm, its free radical-scavenging activity was similar to that of BHT. The $IC_{50}$ value of the extract was 89 ppm, indicating good antioxidant capacity. Moreover, at 5 mg/mL, the extract presented inhibitions of approximately 98.0% and 49.2% on mutagenicity induced by 4-nitroquinoline 1-oxide and sodium azide, respectively. The total polyphenols and flavonoid contents of the extract were 20.1 mg/g and 1.9 mg/g, respectively. Therefore, this study indicates that the ethanolic extract of Cuscutae semen has excellent antioxidative and antimutagenic potential.