Photodissociation dynamics of ketene at 218 nm has been investigated using the velocity map ion-imaging method. Both angular and translational energy distributions for the CO products at different rotational and vibra...Photodissociation dynamics of ketene at 218 nm has been investigated using the velocity map ion-imaging method. Both angular and translational energy distributions for the CO products at different rotational and vibrational states have been obtained. The 2＋1 REMPI spectrum of CO products is also obtained. The results are as bellow： （i） CO products in the first two vibrational states （ v＂=0 and v＂=1 ） exhibit significant rotational excitation. Furthermore the rotational excitation of CO at the v＂=0 level is noticeably higher than that at the v＂=1 level. （ii） It was found that the major photodissociation pathway of ketene at 218 nm is the CH2（ǎ^1A1）＋CO（X^1∑^＋） channel, while the CH2（b^1B1）＋CO（X^1∑^＋） channel and the CH2（X^3B1）＋CO（X^1E^＋） channel are also likely present, （iii） The anisotropy parameters β of CO different rovibronic states all appear to be larger than zero. No significant difference is observed at the two vibrational states,展开更多
Objective： Cancer-associated fibroblasts （CAFs） are one of the hallmarks of the cancer microenvironment. Recent evidence has indicated that CAFs are more competent in enhancing cancer cell growth and migration than...Objective： Cancer-associated fibroblasts （CAFs） are one of the hallmarks of the cancer microenvironment. Recent evidence has indicated that CAFs are more competent in enhancing cancer cell growth and migration than normal fibroblasts. However, the unique protein expression of CAFs has not been fully elucidated. This study aims to investigate the characterizations of colon CAFs by comparing the differential protein expression between CAFs and normal fibroblasts. Methods： Primary fibroblasts were isolated from surgical specimen of human colon cancer and matched normal colonic tissue. Purity of the cell population was verified through immunostain analysis. Total cell lysates and conditioned media from each group of cells were extracted, and protein expression analysis was con- ducted using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry （SELDI-TOF-MS） ProteinChip platform. Results： Most primary cells showed typical fibroblast-like features after two weeks. Increased proportion of a-smooth muscle actin-positive myofibroblasts was detected within the CAFs in four of the six pairs of primary cells. Fibroblast activation protein was weakly expressed in most cells without differences. Using SELDI-TOF-MS ProteinChip platform, four protein peaks mass over charge ratio （m/z） 1142, 3011, 4035, and 4945 were detected in the total cell lysates, and two protein peaks m/z 1368 and 1389 were detected in the conditioned media. The potential candidate proteins found in the Swiss-Prot database include morphogenetic neuropeptides, FMRFamide-related peptides, insulin-like growth factor II, thymosin 13-4-like protein 3, and tight junction-associated protein 1. Conclusions： Using the SELDI-ProteinChip platform, differential protein expressions were identified in colon CAFs compared with normal colonic stromal fibroblasts. The complex proteomic alternations in colon CAFs may play important roles related to the colon cancer microenvironment.展开更多
基金This work is suppotted by the Chinese Academy of Sciences,the Ministry of Science and Technology,and the National Natural Science Foundation of China.
文摘Photodissociation dynamics of ketene at 218 nm has been investigated using the velocity map ion-imaging method. Both angular and translational energy distributions for the CO products at different rotational and vibrational states have been obtained. The 2＋1 REMPI spectrum of CO products is also obtained. The results are as bellow： （i） CO products in the first two vibrational states （ v＂=0 and v＂=1 ） exhibit significant rotational excitation. Furthermore the rotational excitation of CO at the v＂=0 level is noticeably higher than that at the v＂=1 level. （ii） It was found that the major photodissociation pathway of ketene at 218 nm is the CH2（ǎ^1A1）＋CO（X^1∑^＋） channel, while the CH2（b^1B1）＋CO（X^1∑^＋） channel and the CH2（X^3B1）＋CO（X^1E^＋） channel are also likely present, （iii） The anisotropy parameters β of CO different rovibronic states all appear to be larger than zero. No significant difference is observed at the two vibrational states,
基金supported by the National Natural Science Foundation of China (Nos. 81000892, 81071801, and 30801341)the Research Fund for the Doctoral Program of Higher Education of China (No. 200803351107)
文摘Objective： Cancer-associated fibroblasts （CAFs） are one of the hallmarks of the cancer microenvironment. Recent evidence has indicated that CAFs are more competent in enhancing cancer cell growth and migration than normal fibroblasts. However, the unique protein expression of CAFs has not been fully elucidated. This study aims to investigate the characterizations of colon CAFs by comparing the differential protein expression between CAFs and normal fibroblasts. Methods： Primary fibroblasts were isolated from surgical specimen of human colon cancer and matched normal colonic tissue. Purity of the cell population was verified through immunostain analysis. Total cell lysates and conditioned media from each group of cells were extracted, and protein expression analysis was con- ducted using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry （SELDI-TOF-MS） ProteinChip platform. Results： Most primary cells showed typical fibroblast-like features after two weeks. Increased proportion of a-smooth muscle actin-positive myofibroblasts was detected within the CAFs in four of the six pairs of primary cells. Fibroblast activation protein was weakly expressed in most cells without differences. Using SELDI-TOF-MS ProteinChip platform, four protein peaks mass over charge ratio （m/z） 1142, 3011, 4035, and 4945 were detected in the total cell lysates, and two protein peaks m/z 1368 and 1389 were detected in the conditioned media. The potential candidate proteins found in the Swiss-Prot database include morphogenetic neuropeptides, FMRFamide-related peptides, insulin-like growth factor II, thymosin 13-4-like protein 3, and tight junction-associated protein 1. Conclusions： Using the SELDI-ProteinChip platform, differential protein expressions were identified in colon CAFs compared with normal colonic stromal fibroblasts. The complex proteomic alternations in colon CAFs may play important roles related to the colon cancer microenvironment.
