Taking the six common anthocyanidins in nature, i.e. cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin, as examples, this paper summarized the main achievements about the structure-activity relatio...Taking the six common anthocyanidins in nature, i.e. cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin, as examples, this paper summarized the main achievements about the structure-activity relationships of the coloration and stability of anthocyanidins. The coloration and stability of anthocyanidins are funda- mentally determined by the chemical and spatial structures of the anthocyanidins. The electron-deficient state, hydroxylation and methylation patterns, especially the ones on the B-ring, and coplanarity of the three rings of anthocyanidins are inde- pendently or synergetically, positively and/or negatively, influence the coloration and stability of the anthocyanidins. Thereinto, the in vivo colorations of anthocyanins are also related to the organ-selective and crystal- or anthocyanic vacuolar inclusion- related existence of the anthocyanidins. This review could provide a reference for the researches of the structure-optimizing and function-exploiting of anthocyanidins and also for the selection of the crops and cultivars containing specific anthocyani- din profiles.展开更多
AIM: To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy (MC). METHODS: As ...AIM: To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy (MC). METHODS: As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an "autorun" file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer. RESULTS: For classification in 3 groups, both intra- [Cohen's kappa (K) = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st (moderate) to 6th observation (k = 0.94). Also, agreement with reference increased in the last observations (0.90, 1.00 and 1.00, for observers A, B and C, respectively). Validity of 100% was obtained by all observers at their 4th observation. When a 4th (sub)group was considered, inter-observer agreement was almost perfect (K = 0.92) at 6th observation. The relation with reference clearly improved into K (0.93-1.00) and sensitivity (75%-100%) at their 6th observations. CONCLUSION: This MC classification seems to be easily explainable and learnable as shown by excellent intra- and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.展开更多
Ce/Sm ions are covalently grafted to a Keggin polyoxomolybdate cluster[PMo12O40]3-to yield interesting fluorescent-photodarkening molecular systems.Their photoresponce processes are observed to be activated via energy...Ce/Sm ions are covalently grafted to a Keggin polyoxomolybdate cluster[PMo12O40]3-to yield interesting fluorescent-photodarkening molecular systems.Their photoresponce processes are observed to be activated via energy transfer from luminescent fragments to photocoloration components.展开更多
In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of ligaments.Valley phononic crystals were introduced into a topological insulator(TI)system to...In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of ligaments.Valley phononic crystals were introduced into a topological insulator(TI)system to produce topologically protected edge waves(TPEW s)along the topological interfaces.The implementation of chiral topological edge states is different from the implementation of topological edge states of systems with symmetry.Unlike the conventional breaking of mirror symmetry,a new complete band with topological edge modes gap was opened up at the Dirac point by tuning the difference in lengths of the ligaments in the chiral unit cells.We investigated the dispersion properties in chiral systems and applied the dispersion properties to waveguides on the interfaces to achieve designable route systems.Furthermore,we simulated the robust propagation of TPEWs in different routes and demonstrated their immunity to backscattering at defects.Finally,the existence of the valley Hall effect in chiral systems was demonstrated.The study findings may lead to the further study of the topological states of chiral materials.展开更多
基金Supported by the National Natural Science Foundation of China(31060045,31260091)~~
文摘Taking the six common anthocyanidins in nature, i.e. cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin, as examples, this paper summarized the main achievements about the structure-activity relationships of the coloration and stability of anthocyanidins. The coloration and stability of anthocyanidins are funda- mentally determined by the chemical and spatial structures of the anthocyanidins. The electron-deficient state, hydroxylation and methylation patterns, especially the ones on the B-ring, and coplanarity of the three rings of anthocyanidins are inde- pendently or synergetically, positively and/or negatively, influence the coloration and stability of the anthocyanidins. Thereinto, the in vivo colorations of anthocyanins are also related to the organ-selective and crystal- or anthocyanic vacuolar inclusion- related existence of the anthocyanidins. This review could provide a reference for the researches of the structure-optimizing and function-exploiting of anthocyanidins and also for the selection of the crops and cultivars containing specific anthocyani- din profiles.
基金Sociedade Portuguesa de Endoscopia Digestiva (Research Grant 2002)the European Society for Gastrointestinal Endoscopy
文摘AIM: To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy (MC). METHODS: As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an "autorun" file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer. RESULTS: For classification in 3 groups, both intra- [Cohen's kappa (K) = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st (moderate) to 6th observation (k = 0.94). Also, agreement with reference increased in the last observations (0.90, 1.00 and 1.00, for observers A, B and C, respectively). Validity of 100% was obtained by all observers at their 4th observation. When a 4th (sub)group was considered, inter-observer agreement was almost perfect (K = 0.92) at 6th observation. The relation with reference clearly improved into K (0.93-1.00) and sensitivity (75%-100%) at their 6th observations. CONCLUSION: This MC classification seems to be easily explainable and learnable as shown by excellent intra- and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.
基金supported by the National Natural Science Foundation of China(50971063)the Natural Science Foundation of Fujian Province of China(2003F006,2010J01042)the Scientific Research Foundation for Returned Overseas Chinese Scholars of the State Education Ministry of China
文摘Ce/Sm ions are covalently grafted to a Keggin polyoxomolybdate cluster[PMo12O40]3-to yield interesting fluorescent-photodarkening molecular systems.Their photoresponce processes are observed to be activated via energy transfer from luminescent fragments to photocoloration components.
基金supported by the National Natural Science Foundation of China(Grant Nos.11872313 and 12172297).
文摘In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of ligaments.Valley phononic crystals were introduced into a topological insulator(TI)system to produce topologically protected edge waves(TPEW s)along the topological interfaces.The implementation of chiral topological edge states is different from the implementation of topological edge states of systems with symmetry.Unlike the conventional breaking of mirror symmetry,a new complete band with topological edge modes gap was opened up at the Dirac point by tuning the difference in lengths of the ligaments in the chiral unit cells.We investigated the dispersion properties in chiral systems and applied the dispersion properties to waveguides on the interfaces to achieve designable route systems.Furthermore,we simulated the robust propagation of TPEWs in different routes and demonstrated their immunity to backscattering at defects.Finally,the existence of the valley Hall effect in chiral systems was demonstrated.The study findings may lead to the further study of the topological states of chiral materials.