Guan-fu base A(GFA),a new antiarrhythmic alkaloid with a structure of C_(20)-diterpenoid could react rapidly and quantitatively with trifluoroacetic anhydride(TFAA) to produce GFA—TFAA of which the structure was iden...Guan-fu base A(GFA),a new antiarrhythmic alkaloid with a structure of C_(20)-diterpenoid could react rapidly and quantitatively with trifluoroacetic anhydride(TFAA) to produce GFA—TFAA of which the structure was identified by GC—MSD.There was a wide linear range of the GC-ECD method from 10 to 20000ng/ml(r=0.9984).The average recovery of GFA from the spiked plasma was 97.52%.The coefficients of variation of within-day and between-day were less than 7% and 9%,respectively.The method was used in the preclinical experiment of pharmacology of GFA and the results showed that GFA con- centrations in rabbits' plasma within 6 hours after the administration ranged from 0.338± 0.014 to 13.459±5.393μg/ml for dosage 10mg/kg,from 0.133±0.038 to 2.546±0.480 μg/ml for dosage 2mg/kg and from 45.25±10.34 to 535.86±24.36ng/ml for dosage 0.4 mg/kg.展开更多
We consider the contributions of the extra gauge boson Z＇ to the like sign ^- production processes e-＇γ→e＋（μ＋）τ-τ-, induced by the tree-level flavor changing interactions. Since these rare production are fa...We consider the contributions of the extra gauge boson Z＇ to the like sign ^- production processes e-＇γ→e＋（μ＋）τ-τ-, induced by the tree-level flavor changing interactions. Since these rare production are far below the observable level in the Standard Model and other popular new physics models such as the minimal supersymmetric model, we find that, in the topcolor-assisted technicolor models, the Z＇ can give significant contributions to these processes, and with reasonable values of the parameters, the cross section cr can reach several tens of tb and may be detected at the eγ collisions.展开更多
Switching on/off single-molecule magnets(SMMs)at room temperature is still a challenge in moleculebased magnets.Herein,two photochromic Ln-based(Ln=Dy,Tb)phosphonate coordinated polymers were synthesized with regulabl...Switching on/off single-molecule magnets(SMMs)at room temperature is still a challenge in moleculebased magnets.Herein,two photochromic Ln-based(Ln=Dy,Tb)phosphonate coordinated polymers were synthesized with regulable SMM behavior.The reversible room-temperature photo-coloration was an electron transfer process with a generation of relatively stable radicals,characterized by structural analyses,ultraviolet-visible,luminescence and electron spin resonance spectra and magnetic measurements.Importantly,owing to the antiferromagnetic coupling interactions between Ln^(3+) ions and photogenerated radicals,the room-temperature light irradiation surprisingly switched off the SMM behavior,showing the first example of radicalquenched SMMs in the molecule-based magnets.Moreover,the silient SMM behavior could be recovered after eliminating photogenerated radicals via heat treatment,showing a reversible off/on switch of SMMs via light and heat.This work constructs a system for switching off/on SMMs through electron transfer photochromism,providing a visual operation way via naked-eye-detectable coloration for the switchable SMMs.展开更多
文摘Guan-fu base A(GFA),a new antiarrhythmic alkaloid with a structure of C_(20)-diterpenoid could react rapidly and quantitatively with trifluoroacetic anhydride(TFAA) to produce GFA—TFAA of which the structure was identified by GC—MSD.There was a wide linear range of the GC-ECD method from 10 to 20000ng/ml(r=0.9984).The average recovery of GFA from the spiked plasma was 97.52%.The coefficients of variation of within-day and between-day were less than 7% and 9%,respectively.The method was used in the preclinical experiment of pharmacology of GFA and the results showed that GFA con- centrations in rabbits' plasma within 6 hours after the administration ranged from 0.338± 0.014 to 13.459±5.393μg/ml for dosage 10mg/kg,from 0.133±0.038 to 2.546±0.480 μg/ml for dosage 2mg/kg and from 45.25±10.34 to 535.86±24.36ng/ml for dosage 0.4 mg/kg.
文摘We consider the contributions of the extra gauge boson Z＇ to the like sign ^- production processes e-＇γ→e＋（μ＋）τ-τ-, induced by the tree-level flavor changing interactions. Since these rare production are far below the observable level in the Standard Model and other popular new physics models such as the minimal supersymmetric model, we find that, in the topcolor-assisted technicolor models, the Z＇ can give significant contributions to these processes, and with reasonable values of the parameters, the cross section cr can reach several tens of tb and may be detected at the eγ collisions.
基金supported by the National Natural Science Foundation of China(21901133,22171155 and 22071126)the State Key Laboratory of Fine Chemicals(KF1905)。
文摘Switching on/off single-molecule magnets(SMMs)at room temperature is still a challenge in moleculebased magnets.Herein,two photochromic Ln-based(Ln=Dy,Tb)phosphonate coordinated polymers were synthesized with regulable SMM behavior.The reversible room-temperature photo-coloration was an electron transfer process with a generation of relatively stable radicals,characterized by structural analyses,ultraviolet-visible,luminescence and electron spin resonance spectra and magnetic measurements.Importantly,owing to the antiferromagnetic coupling interactions between Ln^(3+) ions and photogenerated radicals,the room-temperature light irradiation surprisingly switched off the SMM behavior,showing the first example of radicalquenched SMMs in the molecule-based magnets.Moreover,the silient SMM behavior could be recovered after eliminating photogenerated radicals via heat treatment,showing a reversible off/on switch of SMMs via light and heat.This work constructs a system for switching off/on SMMs through electron transfer photochromism,providing a visual operation way via naked-eye-detectable coloration for the switchable SMMs.
