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        검색결과 17

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A glassy carbon electrode modified with a composite consisting of electrodeposited chitosan and carboxylated multi-walled carbon nanotubes (e-CS/MWCNTs/GCE) was used as a working electrode for simultaneous determination of dopamine (DA), serotonin (5-HT) and melatonin (MT), which were related to circadian rhythms. The electrochemical characterizations of the working electrode were carried out via electrochemical impedance spectroscopy and chronocoulometry. It was found that electrochemical modification method, that was cyclic voltammetry, may can cause continuous CS polymerization on MWCNTs surface to form a dense membrane with more active sites on the electrode, and the electrochemically active surface area of e-CS/MWCNTs/GCE obtained was about 7 times that of GCE. The electrochemical behaviour of DA, 5-HT and MT on working electrode were carried out via differential pulse voltammetry and cyclic voltammetry. The results showed that e-CS/MWCNTs/GCE solved the problem that the bare electrode could not detect three substances simultaneously, and can catalyze oxidation potential difference as low as 0.17 V of two substances reaction at the same time, indicating very good electrocatalytic activity. By optimizing the detection conditions, the sensor showed a good linear response to DA, 5-HT and MT in the range of 20-1000 μmol/L, 9-1000 μmol/L and 20-1000 μmol/L, and the detection limits were 12 μmol/L, 10 μmol/L and 22 μmol/L (S/N = 3), respectively. In addition, the proposed sensor was successfully applied to the simultaneous detection of DA, 5-HT and MT in human saliva samples.
        4,200원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, reduced graphene oxide/polypyrrole (rGO/PPy) particles were synthesized and used to measure the amount of dopamine (DA) electrochemically. The obtained rGO/PPy particle was characterized by Fourier Transform Infrared Spectrophotometer (FTIR), UV–Visible Spectrophotometer (UV–Vis), and X-Ray Diffraction Diffractometry (XRD). To investigate the DA sensor performance, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to acquire electrochemical measurements of the sensor. Current values of 1.65 and 5.9 mA were observed in the CV at 0.2 mM and 1.2 mM concentrations of target molecule, respectively. Under optimized conditions, the linear calibration plots were found to exhibit significant sensitivity in the linear range of 0.2 and 1.2 mM, with a corresponding detection limit of 0.061 μM for DA. The results obtained were similar to the sensor results of DA made using precious metals. This work was a demonstration of the feasibility of high-sensitivity electrochemical analysis with conductive carbon materials without the use of precious metals. It was also observed that the cost-effective rGO/PPy exhibited a very high potential for DA detection.
        4,000원
        3.
        2023.10 구독 인증기관·개인회원 무료
        The salivary glands of hard ticks consist of three types (type I, II, and III) of acini according to their functions and location. The type II and III acini play critical roles in tick salivation, which is likely controlled by a variety of neuropeptides or neurotransmitter via interaction with their receptor, G protein-coupled receptors (GPCRs). Orchestration of dopamine receptor (D1) and invertebrate specific D1-like dopamine receptor (InvD1L) located in type II and III acini precisely control tick salivary secretion via collection of primary saliva in the lumen and expulsion of collected saliva, respectively. The two dopamine receptors (D1 and InvD1L) in Haemaphysalis longicornis were identified as 1278 bp (426 aa) and 1362 bp (454 aa) in length, respectively. Both dopamine receptors were functionally analyzed through Ca2+ and cAMP assay using the heterologous expression system. The transcripts of D1 and InvD1L were profiled from synganglion and salivary glands of female ticks (unfed, 3/18/60/96 post blood meal and replete). D1 and InvD1L were significantly upregulated in the early phase of blood feeding from female H. longicornis. Salivary secretion induced by dopamine was significantly reduced by RNAi of D1 and InvD1L. Interestingly, RNAi of two dopamine receptors induced a significantly longer period of blood feeding in female ticks, which were significantly lighter after feeding than control. Taken together, it was suggested that D1 and InvD1L play critical roles in early and late phase of tick blood feeding for feeding capability.
        5.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 파킨슨병 환자를 대상으로 16주간 복합운동을 수행하였을 때 혈중 도파민 농도, 기능적 체력 및 삶의 질에 어떠한 영향을 미치는지를 규명하는데 있다. 이를 위해 본 연구에 참여한 60 대 이상의 파킨슨병 환자 24명을 운동군(n=12)과 통제군(n=12)으로 분류한 후 운동군을 대상으로 16주 동안 주 2회, 회기 당 70분의 복합운동을 실시하였다. 복합운동 실시 전·후 항목별 차의 비교를 위해 그룹 내 차이는 대응 t 검정, 그룹 간 차이는 독립 t 검정, 상호작용 검증을 위해 이원 반복측정 분산분석을 사용 하였으며, 각 항목별 통계적 유의수준은 .05로 설정하였다. 그 결과 첫째, 도파민 농도는 운동군(p<.01)이 16주간 운동 전보다 운동 후 유의하게 증가하였고, 통제군의 경우 유의한 차이가 나타나지 않았다. 둘째, 기능적 체력에서 악력은 운동군(p<.001)과 통제군(p<.05) 모두 16주간 운동 전보다 운동 후 유의하게 증가 하였고, 덤벨들기(p<.001), 의자 일었다 앉기(p<.001), 3m 걸어갔다 돌아오기(p<.01)가 16주간 운동 전보다 운동 후 운동군에서 유의한 차이를 보였고, 통제군은 유의한 차이가 나타나지 않았다. 셋째, 삶의 질은 운동군(p<.001)이 16주간 운동 전보다 운동 후 유의하게 증가하였다. 이상의 결과를 종합해 볼 때 16주간 의 복합운동은 파킨슨병 환자에게 매우 효과적임을 알 수 있었으며, 도파민 농도를 증가시키고 근력, 근지 구력, 평형성 및 보행능력 등 기능적 체력과 삶의 질을 향상시키는데 도움을 줄 수 있다고 사료된다.
        4,300원
        6.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biomass porous carbons derived from Laminaria japonica were prepared by KOH and H3PO4 activation methods, respectively. The results indicated that the chemical activation had an apparent effect on the molecular framework and space of materials. To enhance the selective adsorption for organic acids, biomass carbons were modified by dopamine combined with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. The SEM and BET results illustrated the effect of the chemical activation approach on the morphology and porous texture. The biomass porous carbon using KOH activation method had the highest surface area (up to 1558 m2/ g). Compared with unmodified materials, the modified materials showed higher adsorption capacity for organic acids (27.90 μg/mL for chlorogenic acid and 25.47 μg/mL for caffeic acid). It was suggested that modification of porous carbons might be a viable pathway to increase the specific adsorption affinity and efficiency for organic acids in dried jujube samples.
        4,000원
        7.
        2020.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Dopamine (DA) receptor (D1 and D2-like receptors) agonists are known to affect expression levels of DA receptors. Rotigotine, a DA D2-like receptor agonist, has been developed for treating Parkinson’s disease (PD). However, its role in PD by acting through DA D2-like receptors has not been fully understood yet. The purpose of this study was to investigate neuroprotective effects of rotigotine through DA D2 and D3 receptors in 6-hydroxydopamine (6-OHDA) induced mouse model of PD. Expression level of tyrosine hydroxylase (TH) was examined using immunohistochemistry and Western blot analysis. Results revealed that unilateral injection of 6-OHDA into the midbrain caused significant loss of TH positive cells in the substantia nigra, whereas rotigotine inhibited such loss of TH cells in 6-OHDA-induced mouse model of PD. In vitro experiments demonstrated that rotigotine increased expression levels of TH against 6-OHDA-induced toxicity. The expression level of TH after treatment with L’741,626, a D2 receptor antagonist was decreased more than that after treatment with GR 103691, a D3 receptor antagonist. These results suggest that rotigotine can protect DA neurons against 6-OHDA induced toxicity and that the protective effect of rotigotine for DAergic neurons through a DA D2 receptor is stronger than that through a DA D3 receptor.
        4,000원
        8.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 이 연구에서는 도파민이 적용된 히알루론산 가교 하이드로겔을 제조하고 항산화 활성을 조사하였다. 방법: 먼저 히알루론산과 p(HEMA)로 구성된 상호침투고분자구조로 후처리 한 p(HEMA) 기반 하이드로겔을 제조하였다. 다음으로 아마이드 결합반응을 통해 도파민이 적용된 항산화 하이드로겔을 제조하였다. 항산화 활성의 평가는 ABTS 와 DDPH 라디칼 소거능 방법을 사용하였다. 결과: 도파민이 적용된 하이드로겔은 유의한 항산화 활성을 나타내었다. 히알루론산의 가교는 하이드로겔 표면의 습윤성을 개선시킨 반면에 도파민이 적용된 하이드로겔은 대조군과 비교하여 유의한 차이를 나타내지 못했다. 도파민이 적용된 하이드로겔은 높은 광투율을 나타내었다. (>88%) 결론: 도파민이 결합된 히알루론산의 가교에 기초한 항산화 하이드로겔의 개발이 안의료 및 생물의학 재질 개발에 도움을 줄 수 있을 것으로 사료된다.
        4,000원
        10.
        2018.05 구독 인증기관·개인회원 무료
        본 연구에서는 해수를 유도용액으로 사용하고 하수처리수를 공급수로 사용하는 정삼투막 공정의 유기/바이오 오염물에 의한 막오염을 저감하기 위해 폴리도파민/탄소 나노 튜브 복합 분리막을 제작하였다. 분리막은 기존 계면중합반응에 탄소 나노 튜브를 첨가하여 초박형 복합 분리막을 제조한 후, 폴리도파민으로 코팅시켜 제조하였다. 제작 된 분리막은 알긴산나트륨(Sodium alginate)용액과 미생물(Pseudomonas aeruginosa PA01) 부착 실험을 통하여 수투과도와 막오염도를 평가하였다. 그 결과, 폴리도파민/탄소 나노 튜브 복합 분리막은 복합되지 않은 분리막에 비하여 높은 수투과도와 낮은 막오염 성능을 보였다.
        12.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 큰 각광을 받고 있는 표면개질소재 중 하나인 도파민은 알칼리 수용액상에서 자발적으로 반응이 진행되어 금속, 고분자 등 거의 모든 소재에 강하게 흡착되는 물질로 흡착 메커니즘 및 반응 후 최종구조에 관해 많은 논란이 있다. 기 존의 도파민의 최종구조는 aryl-aryl 결합에 의한 고분자 구조가 제안되었지만, 본 연구에서는 구조분석을 통해 기존에 제안된 aryl-aryl 결합이 형성되지 않는 결과와 열적거동을 통해 고분자의 특징이 나타나지 않는 것을 확인하였으며, 기체투과거동을 통해 고분자와 같이 비다공성 코팅층을 형성하지 못하는 결과를 토대로, 도파민의 최종구조는 2차 결합에 의한 초분자 구조 로 서로 응집되어 있는 것으로 판단된다.
        4,000원
        17.
        2014.09 서비스 종료(열람 제한)
        Melatonin has several known physiological functions, the main one being synchronization of daily and seasonal rhythms. In addition, melatonin has been reported to influence reproduction and behavioral rhythms with varying results depending on the species. To date, it remains unknown how this rhythm in locomotor activity is controlled endogenously, although there must be coordination of chemical and molecular drivers. However, the species is poorly characterized at molecular level with little sequence information available in public databases. The aim of study was to clarify involvement of endogenous melatonin rhythms and locomotor activity in day-night activity of the eel, Anguilla japonica which is an economically important but endangered species. The levels during daytime (zeitgeber time; ZT 6) were significantly (P<0.05) lower than those during nighttime (ZT 18). A similar pattern was persisted under DD conditions, whereas it disappeared under LL conditions and ocular melatonin levels remained low. Therefore, it is likely that ocular melatonin levels of the nocturnal eel reared under LD and DD conditions fluctuate in a daily/circadian manner and night-related physiological processes are dependent on eel locomotor activities which is a nocturnal species. We found that similar number of genes were differentially expressed between day (ZT6) and nighttime (ZT18), suggesting that during the nighttime also important in differential gene expression with daytime. This work also provides essential information for further studies investigating the molecular basis of daily/circadian system in this species.