• Nuclear Engineering and Technology
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• 제31권5호
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• pp.498-505
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• 1999

Trivalent actinide-lanthanide group separation is difficult to perform on an industrial scale, because of the many drawbacks of the available chemical process. In this paper, picolinamide(C$_{8}$H$_{17}$) is synthesized and characterized, and extraction yields of Am-241, Eu-152 and Nd are determined in batch extraction experiments. In particular, the influence of the solvent is described. The extraction yields of Am-241, Eu-152 and Nd depended on the LiNO$_3$ concentration, the picolinamide(C$_{8}$H$_{17}$) concentration and the acidity. A favorable picolinamide(C$_{8}$H$_{17}$) concentration was found to be about 2M. The appropriate nitric acid concentration and LiNO$_3$ concentration were confirmed to be about 0.125M and 3M, respectively. The separation factor of Am and Eu was about 9.9 at optimum conditions. The picolinamide(C$_{8}$H$_{17}$) is a very promising extractant for the actinide(III)-lanthanides(III) separation.aration.aration.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.310-311
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• 1999

• 한국융합학회논문지
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• 제8권1호
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• pp.115-121
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• 2017

AHR(Aryl Hydrocarbon Receptor, 방향성탄화수소 수용체)은 리간드에 의해 활성화되어 체내 외래물질의 대사를 조절하는 전사인자다. 생체 내에서 AHR의 생리학적 역할은 오랜 기간 연구되어 왔으나 antagonist를 비롯한 적절한 화학적 도구의 부재로 그 역할 규명이 제한되어 있다. AHR이 암을 비롯한 여러 질병의 발병기전에 관여되어 있다는 것이 밝혀짐에 따라 유효한 약물 표적으로 간주되나 화학적 도구의 부재로 인해 치료용 약물 개발 역시 제한되어 있다. 기존 antagonist 들은 저농도에서는 활성이 있으나 높은 농도에서는 AHR의 활성화를 유도하는 부분적 antagonist이므로 순수 저해활성을 가지는 신규 antagonist의 개발이 필요하다. 본 연구에서는 2-methyl-4-(2-methylphenyldiazenyl)phenyl picolinamide의 o-toluidinyl 고리구조의 변경하여 활성을 평가하는 유기화학과 분자생물학의 융합연구를 통하여 o-toluidinyl 구조를 최적화하였다.

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1211-1216
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• 2008

A series of DTPA-bis(amides) functionalized by pyridine (1a-c) and N-phenylpicolinamide) (1d-e) and their Gd(III)-complexes of the type [Gd(1)($H_2O$)]·x$H_2O$ (2a-e) were prepared and characterized by analytical and spectroscopic techniques. Potentiality of 2a-e as contrast agents for magnetic resonance imaging (MRI CA) was investigated by measuring relevant physicochemical properties and relaxivities and compared with [Gd(DTPA-BMA)($H_2O$)] (DTPA-BMA=N,N''-di(methylcarbamoylmethyl)diethylenetriamine-N,N',N''-triacetate) ($Omniscan^{(R)}$). The R1 relaxivities of aqueous solutions of 2a-c are in the range of 3.33 -5.02 $mM^{-1}$$sec^{-1}$, which are comparable with those of $Omniscan^{(R)}$ (r1=4.58 $mM^{-1}sec^{-1}$). Complexes 2d-e, insoluble in water, exhibit relatively higher R1 values (8.1- 8.3 $mM^{-1}sec^{-1}$) in HP-$\beta$-CD solutions.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2980-2984
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• 2010

A new poly (vinyl chloride) (PVC) membrane electrode that is highly selective to $Mn^{+2}$ ions was prepared using N,N'-bis(2'-pyridinecarboxamide)-1,2-ethane ($bpenH_2$) as a suitable neutral carrier. This concentration range ($1.0{\times}10^{-5}$ to $1.0{\times}10^{-1}\;M$) with Nernstian slope of $29.3{\pm}0.5\;mV$ per decade. The detection limit and the response time of electrode were $8.0{\times}10^{-6}\;M$ and (${\leq}15\;s$) respectively. The membrane can be used for more than two months without observing any divergence. The electrodes exhibited excellent selectivity for $Mn^{+2}$ ion over other mono-, di- and trivalent cations. Selectivity coefficients were determined by the matched potential method (MPM). The electrode can be used in the pH range from 4.0 - 9.0. The isothermal coefficient of this electrode amounted to 0.00023 V/$^{\circ}C$. The stability constant (log $K_s$) of the $Mn^{+2}$ - $bpenH_2$ complex was determined at $25^{\circ}C$ by potentiometric titration in mixed aqueous solution. The proposed electrode was applied to the determination of $Mn^{+2}$ ions in real samples.

• Korean Journal of Radiology
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• 제25권8호
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• pp.742-748
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• 2024

Objective: ¹⁸F-N-(2-(Diethylamino)ethyl)-5-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy) picolinamide (¹⁸F-PFPN) is a novel positron emission tomography (PET) probe designed to specifically targets melanin. This study aimed to evaluate the diagnostic feasibility of ¹⁸F-PFPN in patients with ocular or orbital melanoma. Materials and Methods: Three patients with pathologically confirmed ocular or orbital melanoma (one male, two females; age 41-59 years) were retrospectively reviewed. Each patient underwent comprehensive ¹⁸F-PFPN and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET scans. The maximum standardized uptake value (SUV_max) of the lesion and the interference caused by background tissue were compared between ¹⁸F-PFPN and ¹⁸F-FDG PET imaging. In addition, the effect of intrinsic pigments in the uvea and retina on the interpretation of the results was examined. The contralateral non-tumorous eye of each patient served as a control. Results: All primary tumors (3/3) were detected using ¹⁸F-PFPN PET, while only two primary tumors were detected using ¹⁸F-FDG PET. Within each lesion, the SUV_max of ¹⁸F-PFPN was 2.6 to 8.3 times higher than that of ¹⁸F-FDG. Regarding the quality of PET imaging, the physiological uptake of ¹⁸F-FDG PET in the brain and periocular tissues limited the imaging of tumors. However, ¹⁸F-PFPN PET minimized this interference. Notably, intrinsic pigments in the uvea and retina did not cause abnormal concentrations of ¹⁸F-PFPN, as no anomalous uptake of ¹⁸F-PFPN was detected in the healthy contralateral eyes. Conclusion: Compared to ¹⁸F-FDG, ¹⁸F-PFPN demonstrated higher detection rates for ocular and orbital melanomas with minimal interference from surrounding tissues. This suggests that ¹⁸F-PFPN could be a promising clinical diagnostic tool for distinguishing malignant melanoma from benign pigmentation in ocular and orbital melanomas.