An interesting flourophore, 4-（2,5-dimethoxyphenylmethelene）-2-phenyl-5-oxazolone （DMPO） was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5-dimethoxybenzaldehyde in acetic anhydride in...An interesting flourophore, 4-（2,5-dimethoxyphenylmethelene）-2-phenyl-5-oxazolone （DMPO） was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5-dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4-（2,5-dimethoxy-phenyl- methelene）-2-phenyl-5-oxazolone （DMPO） were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of mole- cules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B-type class of Steven＇s Classifica- tion. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.展开更多
Purpose: To evaluate planning quality of Stereotactic body Radiotherapy (SBRT) with multiple lungmetastases generated by the Pinnacle and Tomotherapy planning systems, respectively. Methods and Materials: Nine randoml...Purpose: To evaluate planning quality of Stereotactic body Radiotherapy (SBRT) with multiple lungmetastases generated by the Pinnacle and Tomotherapy planning systems, respectively. Methods and Materials: Nine randomly selected patients diagnosed with non-small cell lung carcinoma with multiple lesions were planned with Philips Pinnacle (version 9.2, Fitchburg, WI) and Tomotherapy (version 4.2, Madison, WI), respectively. Both coplanar and non-coplanar IMRT plans were generated on Pinnacle system. A total dose of 60 Gy was prescribed to cover 95% of Planning Target Volume (PTV) in 3 fractions based on the RTOG0236 protocol prescription [1]. All plans with single isocenter setting were used for multiple lesions planning. A set of nine static beams were used for Pinnacle plansusing Direct Machine Parameters Optimization (DMPO) algorithm of RTOT0236 dose constraints. Planning outcomes such as minimum and mean doses, V95, D95 (95% of target volume receivesprescription dose), D5, and D1 to PTV, maximum dose to heart, esophagus, cord, trachea, brachial plexus, rib, chest wall, and liver, mean dose toliver, total lung, right and left lung, volume of chest wall receives 30 Gy, volume of lungs receives 5 Gy and 20 Gy (V5 and V20), conformity index (CI) and heterogeneity index (HI) were all reported for evaluation. Results: Mean volume of PTV was 37.77 ± 23.4 cm3. D95 of PTV with Tomotherapy, coplanar, non-coplanar plan was 60.2 ± 0.3 Gy, 58.6 ± 1.2 Gy, and 59.1 ± 0.7 Gy, respectively. Mean dose to PTV was lower for Tomotherapy (p 5 (p 1 (p = 0.001). CI was higher with Tomotherapyplans (p p 5 which needs more attention for toxicity analysis.展开更多
Purpose: To evaluate planning quality and dosimetric differences of clinically deliverable Intensity-modulated Radiation Therapy lung plans generated from Tomotherapy, Pinnacle3, and RayStationTM treatment planning sy...Purpose: To evaluate planning quality and dosimetric differences of clinically deliverable Intensity-modulated Radiation Therapy lung plans generated from Tomotherapy, Pinnacle3, and RayStationTM treatment planning systems. Method and Materials: Ten patients diagnosed with non-small-cell lung carcinoma (NSCLC) previously treated with plans on Pinnacle using Direct Machine Parameter Optimization were randomly selected and re-planned with Tomotherapy dose volume constraints and same beam geometry with RayStation Multi Criteria Optimization (MCO) equivalent uniform dose (EUD) or dose volume constraints, respectively.? Prescription was established as 60 Gy to cover > 95% of PTV. Planning outcomes such as D95 (95% of volume of PTV receiving the prescribed dose), D5, D33, mean heart and lung doses, V20 (volume of lung receiving 20 Gy), and max cord dose of 1cm3 were evaluated according to our departmental clinical protocols. Conformity index (CI = PTV / prescription isodose volume) and homogeneity index (HI = D5/D95) were also reported simultaneously. All plans were successfully uploaded for delivery verification. Results: Mean volume of calculated PTV was 356 ± 141 cm3. The planning results indicated that CI, HI, D95 and D5 of PTV, V20 of lung, and 1cm3 max cord dose were comparable but with better overall dosimetric distributions with conformity and homogeneity index from Tomotherapy plans in comparison to both Pinnacle and RayStation planning outcomes. Conclusions: Tomotherapy plans achieved better uniform tumor coverage with fewer hot spots while sparing more critical structures with superior dose fall-off. RayStation plans with MCO automatically generated a set of Pareto optimized solutions with given objectives to allow tradeoffs between targets and critical organs and tended to achieve better tumor coverage compared to Pinnacle. All three planning algorithms can generate clinical deliverable IMRT lung plans while Tomotherapy plans provide superior dosimetric indexes compared to Pinnacle and RayStation due to its unique beamlet optimization process with high modulation.展开更多
Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-...Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-dimensional conformal radiation therapy (3DCRT), two-step intensity-modulated radiation therapy (TS-IMRT) and direct machine parameter optimization intensity-modulated radiation therapy (DMPO-IMRT) after breast-conserving surgery. Methods: For each of 20 randomly chosen patients, 4 plans were designed using 4 irradiation techniques. The prescribed dose was 50 Gy/2 Gy/25 f, 95% of the planning target volume received this dose. The cumulated DVHs and 3D dose distributions of CR, 3DCRT, TS-IMRT and DMPO-IMRT plans were compared. Results: For the homogeneity indices, no statistically significant difference was observed among CR, 3DCRT, TS-IMRT and DMPO-IMRT while the difference of the conformality indices were statistically significant. With regard to the organs at risk, IMRT and 3DCRT showed a significantly fewer exposure dose to the ipsilateral lung than CR in the high-dose area while in the low-dose area, IMRT demonstrated a significant increase of exposure dose to ipsilateral lung, heart and contralateral breast compared with 3DCRT and CR. In addition, the monitor units (MUs) for DMPO-IMRT were approximately 26% more than those of TS-IMRT and the segments of the former were approximately 24% less than those of the latter. Conclusion: Compared with CR, 3DCRT and IMRT improved the homogeneity and conformity of PTV, reduced the irradiated volume of OARs in high dose area but IMRT increased the irradiated volume of OARs in low dose area. DMPO-IMRT plan has fewer delivery time but more MUs than TS-IMRT.展开更多
As an alternative method, matrix-assisted laser desorption/ionization with Fourier transform mass spectrometry （MALDI-FTMS） has been successfully used to detect and identify free radical adducts with small molecular...As an alternative method, matrix-assisted laser desorption/ionization with Fourier transform mass spectrometry （MALDI-FTMS） has been successfully used to detect and identify free radical adducts with small molecular weights of hydroxyl and 2-cyano-2-propyl radicals trapped with 5,5-dimethylpyrroline N-oxide （DMPO）. The detection and identification by MS/MS experiments using sustained offresonance irradiation collision-induced dissociation （SORI-CID） of [（DMPO＋·OH-·H）＋H^＋] （m/z 130.0868） and [DMPO＋2 ·CH（CH3）2CN＋H^＋] （m/z 250.1917） have demonstrated that MALDI-FTMS could be an effective method for detection and identification of free radical adducts. Other radical adducts have been also detected and identified. The approach of MALDI-FTMS is simple, fast, and sensitive which has potential for high-throughput analysis.展开更多
That the photosensitive action of hematoporphyrin can damage tumor cells, has attracted much attention recently. However, its mechanism of action is not very clear. Some reported that the damage is due to the producti...That the photosensitive action of hematoporphyrin can damage tumor cells, has attracted much attention recently. However, its mechanism of action is not very clear. Some reported that the damage is due to the production of singlet oxygen （1O2）, a cy-展开更多
文摘An interesting flourophore, 4-（2,5-dimethoxyphenylmethelene）-2-phenyl-5-oxazolone （DMPO） was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5-dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4-（2,5-dimethoxy-phenyl- methelene）-2-phenyl-5-oxazolone （DMPO） were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of mole- cules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B-type class of Steven＇s Classifica- tion. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.
文摘Purpose: To evaluate planning quality of Stereotactic body Radiotherapy (SBRT) with multiple lungmetastases generated by the Pinnacle and Tomotherapy planning systems, respectively. Methods and Materials: Nine randomly selected patients diagnosed with non-small cell lung carcinoma with multiple lesions were planned with Philips Pinnacle (version 9.2, Fitchburg, WI) and Tomotherapy (version 4.2, Madison, WI), respectively. Both coplanar and non-coplanar IMRT plans were generated on Pinnacle system. A total dose of 60 Gy was prescribed to cover 95% of Planning Target Volume (PTV) in 3 fractions based on the RTOG0236 protocol prescription [1]. All plans with single isocenter setting were used for multiple lesions planning. A set of nine static beams were used for Pinnacle plansusing Direct Machine Parameters Optimization (DMPO) algorithm of RTOT0236 dose constraints. Planning outcomes such as minimum and mean doses, V95, D95 (95% of target volume receivesprescription dose), D5, and D1 to PTV, maximum dose to heart, esophagus, cord, trachea, brachial plexus, rib, chest wall, and liver, mean dose toliver, total lung, right and left lung, volume of chest wall receives 30 Gy, volume of lungs receives 5 Gy and 20 Gy (V5 and V20), conformity index (CI) and heterogeneity index (HI) were all reported for evaluation. Results: Mean volume of PTV was 37.77 ± 23.4 cm3. D95 of PTV with Tomotherapy, coplanar, non-coplanar plan was 60.2 ± 0.3 Gy, 58.6 ± 1.2 Gy, and 59.1 ± 0.7 Gy, respectively. Mean dose to PTV was lower for Tomotherapy (p 5 (p 1 (p = 0.001). CI was higher with Tomotherapyplans (p p 5 which needs more attention for toxicity analysis.
文摘Purpose: To evaluate planning quality and dosimetric differences of clinically deliverable Intensity-modulated Radiation Therapy lung plans generated from Tomotherapy, Pinnacle3, and RayStationTM treatment planning systems. Method and Materials: Ten patients diagnosed with non-small-cell lung carcinoma (NSCLC) previously treated with plans on Pinnacle using Direct Machine Parameter Optimization were randomly selected and re-planned with Tomotherapy dose volume constraints and same beam geometry with RayStation Multi Criteria Optimization (MCO) equivalent uniform dose (EUD) or dose volume constraints, respectively.? Prescription was established as 60 Gy to cover > 95% of PTV. Planning outcomes such as D95 (95% of volume of PTV receiving the prescribed dose), D5, D33, mean heart and lung doses, V20 (volume of lung receiving 20 Gy), and max cord dose of 1cm3 were evaluated according to our departmental clinical protocols. Conformity index (CI = PTV / prescription isodose volume) and homogeneity index (HI = D5/D95) were also reported simultaneously. All plans were successfully uploaded for delivery verification. Results: Mean volume of calculated PTV was 356 ± 141 cm3. The planning results indicated that CI, HI, D95 and D5 of PTV, V20 of lung, and 1cm3 max cord dose were comparable but with better overall dosimetric distributions with conformity and homogeneity index from Tomotherapy plans in comparison to both Pinnacle and RayStation planning outcomes. Conclusions: Tomotherapy plans achieved better uniform tumor coverage with fewer hot spots while sparing more critical structures with superior dose fall-off. RayStation plans with MCO automatically generated a set of Pareto optimized solutions with given objectives to allow tradeoffs between targets and critical organs and tended to achieve better tumor coverage compared to Pinnacle. All three planning algorithms can generate clinical deliverable IMRT lung plans while Tomotherapy plans provide superior dosimetric indexes compared to Pinnacle and RayStation due to its unique beamlet optimization process with high modulation.
文摘Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-dimensional conformal radiation therapy (3DCRT), two-step intensity-modulated radiation therapy (TS-IMRT) and direct machine parameter optimization intensity-modulated radiation therapy (DMPO-IMRT) after breast-conserving surgery. Methods: For each of 20 randomly chosen patients, 4 plans were designed using 4 irradiation techniques. The prescribed dose was 50 Gy/2 Gy/25 f, 95% of the planning target volume received this dose. The cumulated DVHs and 3D dose distributions of CR, 3DCRT, TS-IMRT and DMPO-IMRT plans were compared. Results: For the homogeneity indices, no statistically significant difference was observed among CR, 3DCRT, TS-IMRT and DMPO-IMRT while the difference of the conformality indices were statistically significant. With regard to the organs at risk, IMRT and 3DCRT showed a significantly fewer exposure dose to the ipsilateral lung than CR in the high-dose area while in the low-dose area, IMRT demonstrated a significant increase of exposure dose to ipsilateral lung, heart and contralateral breast compared with 3DCRT and CR. In addition, the monitor units (MUs) for DMPO-IMRT were approximately 26% more than those of TS-IMRT and the segments of the former were approximately 24% less than those of the latter. Conclusion: Compared with CR, 3DCRT and IMRT improved the homogeneity and conformity of PTV, reduced the irradiated volume of OARs in high dose area but IMRT increased the irradiated volume of OARs in low dose area. DMPO-IMRT plan has fewer delivery time but more MUs than TS-IMRT.
基金Project supported by the National Natural Science Foundation of China （Nos. 20475063 and 20475059） and Chinese Academy of Sciences （No. KGCX2-SW-213-04）.
文摘As an alternative method, matrix-assisted laser desorption/ionization with Fourier transform mass spectrometry （MALDI-FTMS） has been successfully used to detect and identify free radical adducts with small molecular weights of hydroxyl and 2-cyano-2-propyl radicals trapped with 5,5-dimethylpyrroline N-oxide （DMPO）. The detection and identification by MS/MS experiments using sustained offresonance irradiation collision-induced dissociation （SORI-CID） of [（DMPO＋·OH-·H）＋H^＋] （m/z 130.0868） and [DMPO＋2 ·CH（CH3）2CN＋H^＋] （m/z 250.1917） have demonstrated that MALDI-FTMS could be an effective method for detection and identification of free radical adducts. Other radical adducts have been also detected and identified. The approach of MALDI-FTMS is simple, fast, and sensitive which has potential for high-throughput analysis.
文摘That the photosensitive action of hematoporphyrin can damage tumor cells, has attracted much attention recently. However, its mechanism of action is not very clear. Some reported that the damage is due to the production of singlet oxygen （1O2）, a cy-
