کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5407703 | 1393227 | 2006 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Dynamic nuclear polarization properties of nitroxyl radicals used in Overhauser-enhanced MRI for simultaneous molecular imaging
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
DNP parameters relevant to Overhauser-enhanced magnetic resonance imaging (OMRI) are reported for a few nitroxyl radicals and their corresponding 15N and 2H enriched analogues, used in simultaneous imaging by OMRI. DNP enhancement was measured at 14.529Â mT, using a custom-built scanner operating in a field-cycled mode, for different concentrations, ESR irradiation times and RF power levels. DNP enhancements increased with agent concentration up to 2.5Â mM and decreased above 3Â mM, in tune with ESR line broadening measured at X-band as a function of the agent concentration. The proton spin-lattice relaxation times (T1) measured at very low Zeeman field (14.529Â mT) and the longitudinal relaxivity parameters were estimated. The relaxivity parameters were in good agreement with those independently computed from the linear region of the concentration dependent enhancement. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameters of 14N- and 15N-labeled carbamoyl-PROXYL showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. Upon 2H labeling, about 70% and 40% increases in enhancement for 15N- and 14N-labeled nitroxyl agents were observed, respectively. It is envisaged that the results reported here may enable better understanding of the factors determining DNP enhancement to design suitable 'beacons' for simultaneous molecular imaging by OMRI.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 182, Issue 2, October 2006, Pages 273-282
Journal: Journal of Magnetic Resonance - Volume 182, Issue 2, October 2006, Pages 273-282
نویسندگان
A. Milton Franklin Benial, Kazuhiro Ichikawa, Ramachandran Murugesan, Ken-ichi Yamada, Hideo Utsumi,