• Macromolecular Research
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• 제12권5호
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• pp.459-465
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• 2004

We have synthesized poly(l,4-cyclohexylenedimethylene terephthalate-co-hexamethylene terephthalate) [P(CT-co-HT)] random copolymers having various comonomer contents, from 0 to 100 mol% HT, by melt-condensation and have investigated their crystallization behavior by using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). We observed that P(CT-co-HT)s exhibit clear melting and crystallization peaks in their DSC thermograms and sharp diffraction peaks in their WAXD patterns for all of their copolymer compositions as a result of cocrystallization of the CT and HT units, even though the copolymers are statistically random copolymers. When we plotted the melting and crystallization temperatures of P(CT-co-HT)s and the d-spacings of all the reflections against the copolymer composition, we observed a eutectic point at ca. 80 mol% HT, which suggests that a crystal transition occured from a PCT-type crystal to a PHT-type crystal. Both the DSC and WAXD results support the notion that P(CT-co-HT) copolymers undergo an isodimorphic cocrystallization.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.76-85
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• 2020

This study was conducted to analyze the application of boron compounds, methyl methacrylate (MMA), and heat treatment (HT) on changes in the density, moisture content, and flexural properties of samama (Anthocephalus macrophyllus) wood. Samama wood was impregnated with borax (BX) and boric acid (BA) using a pressure method at 5 atm for 4 h. Afterwards, the wood was impregnated with MMA at the same pressure and duration. Finally, the samama wood was given HT at 90 ℃ and 180 ℃. The results indicate that there was a weight gain of 93.4% in the wood impregnated using BA and MMA monomer and HT at 90 ℃. Consequently, the wood's density increased by 82.3%. Increased MOE and MOR percentages of 32.2% and 29.4%, respectively, were also found. HT at 180 ℃ degraded the wood components and MMA, and consequently, the density, MOE, and MOR also decreased. The wood impregnated by BX, BA, and MMA, and subjected to HT also had decreased moisture content (MC). This research recommends that the application of boron (BX, BA) should be combined with an MMA monomer and HT at 90 ℃ as an alternative method to improve samama wood quality. If darker color is preferable, HT should be conducted at 180 ℃.

• 약학회지
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• 제35권4호
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• pp.326-331
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• 1991

Brain serotonin and its utilization was investigated on stressed rats after feeding high tryptophan diet for a month. High tryptophan fed rats displayed significantly higher level of serum tryptophan, brain tryptophan, serotonin (5-hydroxytryptamine; 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) than the control diet fed rats. When rats were treated with 3 hour immobilization (IMMB) stress, serotonin turnover was slightly increased, but not statistically significant, in control diet group rats. However in high tryptophan diet rats, 3 hr IMMB stress resulted in statistically significantly (p<0.05) decreased the serum tryptophan, brain tryptophan and 5-HT level. The concentration of 5-HIAA was significantly increased indicating accelerated utilization of the brain 5-HT of the high trp. fed rat. The utilization pattern of the serotonin was found to be similar among young and adult rats. Rats on a tryptophan enriched diet displayed higher coping ability to the stress as they exhibited smaller increment of corticosterone level. A possble involvement of opioid system was suggested in serotonin utilization by measuring total $^{3}$[H]-naloxone binding in brain.

• Journal of Acupuncture Research
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• 제28권1호
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• pp.37-44
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• 2011

배경 및 목적 : 봉독약침요법(bee venom pharmacopuncture, BVP)은 rheumatoid arthritis(RA)의 치료에 활용되고 있으나, RA로 인한 염증성 통증에 대한 봉독약침의 진통효과와 specific mechanism은 아직까지 명확하게 밝혀지지 않았다. 이에 본 연구에서는 RA animal model로서 collagen-induced arthritis(CIA) rat model에서 봉독약침의 a1-adrenergic, 5HT-3 그리고 muscarinic cholinergic mechanism을 확인하고자 한다. 방법 : CIA를 유도하기 위하여 male Sprague-Dawley rat에 freund's incomplete adjuvant에 유화(乳化)시킨 bovine type II collagen을 주입하고 14일 후 booster injection 시행하였다. 진통효과는 tail flick latency (TFL)로 평가하였다. 결과 : 관절염의 유도 이후 염증성 통증 역치는 시간이 지나면서 낮아지며, 5주 이후로는 통증 역치에 큰 변화가 없이 유지되었다. 첫 번째 immunization으로부터 5주 경과 후 족삼리($ST_{36}$)에 봉독약침처치(0.25 mg/ kg)를 시행하여 유의한 진통효과를 관찰하였다. 또한 봉독약침의 진통효과는 ondansetron(5HT-3 receptor antagonist, 0.5mg/kg, i.p.), atropine(muscarinic cholinergic receptor antagonist, 1mg/kg, i.p.)의 전처치에 의하여 억제되었으나, prazosin(a1-adrenergic receptor antagonist, 1mg/kg, i.p.)의 전처치에 의해서는 억제되지 않았다. 결론 : 봉독약침은 CIA로 인한 염증성 통증에 유의한 진통효과를 나타내며 그 analgesic mechanism은 5HT-3와 muscarinic cholinergic receptor에 의하여 매개되며 a1-adrenergic receptor에 의하여 매개되지는 않았다.

• Journal of Yeungnam Medical Science
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• 제5권1호
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• pp.93-100
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• 1988

1985년 7월부터 1987년 6월까지 2년 동안 영남대학교 의과대학 부속병원 소아과에 입원한 환자중 신기능에 영향을 미치는 인자가 없는 1세부터 15세까지의 남녀환아 81명을 대상으로 키와 혈장 creatinine 농도를 이용한 공식 $GFR=k{\cdot}Ht/Pcr$ (k=상수)을 이용하여 실제 측정된 creatinine clearance와 Ht/Pcr에서 구해진 $k_M$ (measured k)의 적합성을 연령별로 1~5세(I군), 6~10세(II군), 11~15세(III순) 그리고 전 연령군으로 나누어 검정하였다. 1) 실제 측정된 creatinine clearance ($m{\ell}/min/1.73m^2$)는 I군에서 $109.73{\pm}9.97$, II군에서 $108.26{\pm}9.02$, III군에서 $96.20{\pm}4.72$ 그리고 전 연령군에서는 $105.48{\pm}5.23$이었다. 2) Ht/Pcr과 실제 측정된 creatinine clearance를 이용한 공식에서 얻어진 $k_M$값은 I군에서 $0.49{\pm}0.03$, II군에서 $0.48{\pm}0.02$, III군에서 $0.43{\pm}0.02$ 그리고 전 연령군에서는 $0.47{\pm}0.02$이었다. 3) Ht/Pcr(x)과 실제 측정된 creatinine clearance(y)를 이용하여 각 군별 및 전 연령군의 회귀방정식과 이들간의 얻어진 상관계수(r)는 I군에서 y=0.82x-65.63(r=0.99), II군에서 y=0.61x-23.46(r=0.72), III군에서 y=0.18x+54.44(r=0.54) 그리고 전 연령군에서는 y=0.58x-22.13(r=0.81)로 모두에게 상관관계가 높게 나왔다. 4) 이 회귀방정식을 이용하여 추정된 creatinine clearance($Ccr_E$) 값을 정리한 후, 추정된 creatinine clearance와 Ht/Pcr에서 구한 $k_E$(estimated k)값은 I군에서 $0.48{\pm}0.01$, II군에서 $0.49{\pm}0.01$, III군에서 $0.43{\pm}0.01$ 그리고 전 연령군에서는 0.47이었다. 5) 간군별 $k_M$과 $k_E$의 적합도는 I, II군에서 95~97.5%, III군에서 90~95% 그리고 전 연령군에서는 97.5%~99%로 모두에서 높게 나왔다. 이상의 연구결과를 종합해 보면 Ht/Pcr과 본 연구에서 계산된 $k_M$값을 이용한 공식을 사용하여 신속하고 간편하게 사구체여과율(GFR)을 산출하여 사구체기능을 평가할 수 있다.

• Corrosion Science and Technology
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• 제5권3호
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• pp.94-98
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• 2006

The next generation nuclear power reactor will use Pb-Bi as the cooling material. The steel structure materials such as HT-9 used in the reactor suffer from corrosion when they are exposed to high temperature Pb-Bi. Therefore corrosion should be prevented to use Pb-Bi as the coolant material without any safety problem. One method is to control the oxygen content in Pb-Bi. An appropriate amount of oxygen in Pb-Bi can produce a thin oxide layer on steel, and this layer protects the steel from corrosion attack. Since the required oxygen content in Pb-Bi is in the range of $10^{-5}$ to $10^{-7}$ wt%, this small oxygen content can be controlled by flowing a mixture of hydrogen gas and water vapor. The stagnant corrosion test of HT-9 samples was performed by controlling the oxygen content up to 2,000 hours. The corrosion behavior of HT-9 was analyzed at the temperatures of $500^{\circ}C$ and $650^{\circ}C$ with a reduced condition and a oxygen content of $10^{-6}$ wt%.

• Molecules and Cells
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• 제20권1호
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• pp.69-73
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• 2005

The flavonoid, quercetin, is a low molecular weight substance found in apple, tomato and other fruit. Besides its antioxidative effect, quercetin, like other flavonoids, has a wide range of neuropharmacological actions including analgesia, and motility, sleep, anticonvulsant, sedative and anxiolytic effects. In the present study, we investigated its effect on mouse 5-hydroxytryptamine type 3 ($5-HT_{3A}$) receptor channel activity, which is involved in pain transmission, analgesia, vomiting, and mood disorders. The $5-HT_{3A}$ receptor was expressed in Xenopus oocytes, and the current was measured with the two-electrode voltage clamp technique. In oocytes injected with $5-HT_{3A}$ receptor cRNA, quercetin inhibited the 5-HT-induced inward peak current ($I_{5-HT}$) with an $IC_{50}$ of $64.7{\pm}2.2{\mu}M$. Inhibition was competitive and voltage-independent. Point mutations of pre-transmembrane domain 1 (pre-TM1) such as R222T and R222A, but not R222D, R222E and R222K, abolished inhibition, indicating that quercetin interacts with the pre-TM1 of the $5-HT_{3A}$ receptor.

• 대한한의학회지
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• 제26권4호
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• pp.62-73
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• 2005

Objectives: This study was designed to identify the ergogenic effects of Red ginseng and Paeonia radix mixtures and optimal ratios. Materials and Methods: This study was conducted by administering treatments of Red ginseng and Paeonia radix mixtures to rats and by measuring the time to exhaustion by treadmill running. Results: The treatment of Red ginseng and Paeonia radix mixtures to the rats increased the time to exhaustion by treadmill running. The most potent inhibition of Red ginseng and Paeonia radix mixtures on the 5-HT synthesis and the TPH expression in the dorsal raphe was observed at the dose of 200 mg/kg and the optimal ratio of Red ginseng and Paeonia radix for the maximum efficacy was 50:50. Under normal conditions (not exercise), long-term treatment of Red ginseng and Paeonia radix mixtures did not affect the 5-HT synthesis and the TPH expression in the dorsal raphe, suggesting that Red ginseng and Paeonia radix mixtures does not alter serotonin level in the normal rats. The suppressive effect of Red ginseng and Paeonia radix mixtures on the 5-HT synthesis and the TPH expression during exercise is a possible ergogenic mechanism of these mixtures. Conclusions : Red ginseng and Paeonia radix mixtures reduce exercise-induced fatigue, and have the effect of acting as ergogenic aids on the time to exhaustion by treadmill exercise and on 5-HT synthesis and TPH expression.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1107-1112
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• 2009

The aim of this study is to develop and synthesize $5-HT_{1A}$ receptor imaging agents with WAY-100635 moiety and $^{99m}Tc(CO)_3$ core. WAY-100635 is commonly known as $5-HT_{1A}$ antagonist and its labeled compound ([$^{11}C$] WAY-100635) has been used as effective radioligand for imaging brain $5-HT_{1A}$ receptors with PET(Positron Emission Tomography). However, there are several restrictions in using a radioisotope of C-11 and requires for more effective radioisotopes and ligands. In order to produce a structure most similar to WAY-100635, WAY-100635 derivatives containing a cysteine chelator were designed and confirmed by using in silico (Hyperchem). The novel compounds (7a, 7b, 7c) were prepared in five or 7 steps with yields of 16%, 36% and 42%, respectively and radiolabeled with $[^{99m}Tc(CO)_3(H_2O)_3]^{+}$. The labeling yield was 99% for all the newly synthesized compounds. [$^{99m}Tc(CO)_3$]- WAY-100635 derivatives show a neutral charge which were confirmed by paper electrophoresis.

• 공업화학
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• 제29권3호
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• pp.336-341
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• 2018

기존의 문헌에서는 poly(3-hexylthiophene)(P3HT) 기반의 블록공중합체를 합성하기 위해서 최소 4-5단계 이상의 복잡한 공정을 거쳐야 했고, 일반적으로 분자량, 분자량 분포 및 블록의 비를 조절하기 위해서 단량체 전환율 및 반응 시간을 계속해서 모니터링 해야 한다. 또한, 여러 가지 이유에서 합성 스케일이 수 mg에서 수 g으로 제한되었다. 본 연구에서는 음이온 중합법을 이용해서 P3HT-b-poly(4-vinylprydine) (P4VP)를 오직 2단계로 중합할 수 있었으며, 중합 스케일은 수십 g 정도가 가능하였다. 반응 도중 단량체 전환율 및 농도를 계속 모니터링 해야 하는 번거로움 없이 초기 단량체 당량비만으로 블록 비율과 분자량 분포를 정밀 조절할 수 있었다. 만들어진 P3HT-b-P4VP를 친수성 및 소수성 용매에 녹여 분자 거동을 살펴보았다. 용액의 특성이 용액 속 미셸 구조와 필름 코팅 후 모포로지에 영향을 미친다는 것을 확인했다. P3HT-b-P4VP의 물리적 특성은 적외선-자외선 분광분석법, 원자힘현미경 및 자외선 광전자 분광분석법을 이용하여 평가하였다.