| 1. |
- Chen, Zhen, et al.
(author)
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Synthesis and preliminary evaluation of a novel positron emission tomography (PET) ligand for imaging fatty acid amide hydrolase (FAAH)
- 2020
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In: Bioorganic & Medicinal Chemistry Letters. - : Elsevier. - 0960-894X .- 1464-3405. ; 30:21
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Journal article (peer-reviewed)abstract
- Fatty acid amide hydrolase (FAAH) exerts its main function in the catabolism of the endogenous chemical messenger anandamide (AEA), thus modulating the endocannabinoid (eCB) pathway. Inhibition of FAAH may serve as an effective strategy to relieve anxiety and possibly other central nervous system (CNS)-related disorders. Positron emission tomography (PET) would facilitate us to better understand the relationship between FAAH in certain disease conditions, and accelerate clinical translation of FAAH inhibitors by providing in vivo quantitative information. So far, most PET tracers show irreversible binding patterns with FAAH, which would result in complicated quantitative processes. Herein, we have identified a new FAAH inhibitor (1-((1-methyl-1H-indol-2-yl)methyl)piperidin-4-yl)(oxazol-2-yl)methanone (8) which inhibits the hydrolysis of AEA in the brain with high potency (IC50 value 11 nM at a substrate concentration of 0.5 µM), and without showing time-dependency. The PET tracer [11C]8 (also called [11C]FAAH-1906) was successfully radiolabeled with [11C]MeI in 17 ± 6% decay-corrected radiochemical yield (n = 7) with >74.0 GBq/μmol (2 Ci/μmol) molar activity and >99% radiochemical purity. Ex vivo biodistribution and blocking studies of [11C]8 in normal mice were also conducted, indicating good brain penetration, high brain target selectivity, and modest to excellent target selectivity in peripheral tissues. Thus, [11C]8 is a potentially useful PET ligand with enzyme inhibitory and target binding properties consistent with a reversible mode of action.
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| 2. |
- Yi, Peng, et al.
(author)
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Late Holocene pathway of Asian Summer Monsoons imprinted in soils and societal implications
- 2019
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In: Quaternary Science Reviews. - : Elsevier. - 0277-3791 .- 1873-457X. ; 215, s. 35-44
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Journal article (peer-reviewed)abstract
- The Asian Summer Monsoons (ASM) represent the main source of precipitation in China and East Asia with about one third of the world population and a region of widespread civilizations. Identifying the temporal and spatial patterns (pathways) of these monsoonal events during the Late Holocene to today has been a matter of debate amongst the scientific community. Here we show that the distribution patterns of the cosmogenic isotope Be-10 and oceanic I-127 in the topsoil across China exhibit imprints of the main ASM pathways. Our results indicate the monsoon pathway pattern persisted for several millennia or more and suggest a strong bond between Be-10 and water vapor transport patterns. Our data also reveal a(127)I distribution pattern controlled by the ASM pathways, rather than proximity to the sea or bedrock weathering. The persistent pathway of the ASM during the late Holocene, together with higher than average global soil iodine concentration, may have further strengthened the development of civilizations in this region of the world through reduction of iodine deficiency related diseases. (C) 2019 Elsevier Ltd. All rights reserved.
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| 3. |
- Gao, Yijun, et al.
(author)
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Enhancing PbS Colloidal Quantum Dot Tandem Solar Cell Performance by Graded Band Alignment
- 2019
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In: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 10:19, s. 5729-5734
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Journal article (peer-reviewed)abstract
- Colloidal quantum dot solids are attractive candidates for tandem solar cells because of their widely tunable bandgaps. However, the development of the quantum dot tandem solar cell has lagged far behind that of its single-junction counterpart. One of the fundamental problems with colloidal quantum dot solar cells is the relatively small diffusion length, which limits the quantum dot absorbing layer thickness and hence the power conversion efficiency. In this research, guided by optical modeling and utilizing a graded band alignment strategy, a two-terminal monolithic solution-processed quantum dot tandem solar cell has been successfully fabricated and a power conversion efficiency of 6.8% has been achieved. The band grading approach utilized the complementary tuning of work functions and band alignment through judicious choices of the nanoparticle surface chemistry and quantum dot confined size. This work demonstrates a general approach to improving the efficiency for tandem thin-film solar cells.
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