Objective To evaluate in vivo stability of ethylenedylbis cysteine diethylester (ECD) brain SPECT. Methods Each of 13 normal volunteers (31. 2 ± 11. 8 years) has 12 dynamic SPECK scans ac-quired in 60min 1h after...Objective To evaluate in vivo stability of ethylenedylbis cysteine diethylester (ECD) brain SPECT. Methods Each of 13 normal volunteers (31. 2 ± 11. 8 years) has 12 dynamic SPECK scans ac-quired in 60min 1h after an injection of 99mTc-ECD using a triple headed gamma camera equipped with ultra high resolution fan beam collimators. Average counts per pixel were measured from frontal, temporal, parie-tal, occipital regions, cerebellum, basal ganglia, thalamus and white matter. Regional ECD clearance rates, regional gray-to-white matter (G/W) ratios and the change of the G/W ratio were calculated. Results The average ECD clearance rate was 4. 2% /h, ranged from 3. 03% /h to 5. 41% /h corresponding to white matter and occipital. There was no significant difference between regional ECD clearance rates. Regional G 7W ratio was between 1.27 to 1.75. The G/W ratio of temporal lobe was lower than the occipital ( P <0.05). The change of regional G/W ratio with time is slow. Conclusion Regional ECD distribution is stable in normal brain. ECD clearance from brain is slow and no significant regional difference.展开更多
Earthquakes with magnitudes M ≤ 3.5 were registered in the Andes backarc between ~32.5°S 33.75°S within a temporary experiment from November 2002 to March 2003. Data were collected from 15 seismological bro...Earthquakes with magnitudes M ≤ 3.5 were registered in the Andes backarc between ~32.5°S 33.75°S within a temporary experiment from November 2002 to March 2003. Data were collected from 15 seismological broad band stations, deployed above flat subduction section and also above the transitional to normal section of the Nazca plate. Seismic events were located mostly in part of the Southern Precordillera and Cerrilladas Pedemontanas of Mendoza Province. Focal mechanism solutions were obtained, for selected data between15 kmand35 kmdepths, from P wave first motion using FOCMEC software. A band trending NW-NNW of normal focal mechanism earthquakes is located just by the thrust front towards West, and covers the Southern tip of the Southern Precordillera and the Western side of the Cerrilladas Pedemontanas, Mendoza Province, Argentina. Thrust focal mechanism solutions obtained in the present work for events with magnitude less than or equal to 3.5 also show that the thrust front South of ~33.1°S is located in the same place as Mw ≥ 3.6 earthquakes. The most significant findings in this work are these signals of extensional regimen which appear in a compressional subduction tectonic regimen. Nevertheless the short temporal experiment precludes firm interpretations about this particular phenomenon. Probably it is related to a temporary stress relaxation. The normal earthquakes are likely associated to normal faults, and/or to their subsidiaries, that were inverted by contraction and now re-inverted at least transitorily as normal. These faults, which are near and to the East of the suture between Chilenia and Cuyania Paleozoic terranes, were originally involved in the Cuyo Triassic basin formation.展开更多
The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Fur...The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Further study has proved the normal distributions exist in both the east and west parts of Chinese mainland partitioned along meridian 105°E. The empirical two-dimensional normal distribution functions for the deviations are presented in the paper. The results are of significance in reducing uncertainty of losses assessment immediately after a destroyed earthquake.展开更多
The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the veg...The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season(SOS)based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer–Normalized Difference Vegetation Index data for 2000–13. We then reconstruct the SOS time series based on the temperature data for 1960–2013.The regional mean SOS shows an advancing trend of 1.42 d(10 yr)during 1960–2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d(10 yr)during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d(10 yr)] during 2000–13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region,during 2000–13.展开更多
文摘Objective To evaluate in vivo stability of ethylenedylbis cysteine diethylester (ECD) brain SPECT. Methods Each of 13 normal volunteers (31. 2 ± 11. 8 years) has 12 dynamic SPECK scans ac-quired in 60min 1h after an injection of 99mTc-ECD using a triple headed gamma camera equipped with ultra high resolution fan beam collimators. Average counts per pixel were measured from frontal, temporal, parie-tal, occipital regions, cerebellum, basal ganglia, thalamus and white matter. Regional ECD clearance rates, regional gray-to-white matter (G/W) ratios and the change of the G/W ratio were calculated. Results The average ECD clearance rate was 4. 2% /h, ranged from 3. 03% /h to 5. 41% /h corresponding to white matter and occipital. There was no significant difference between regional ECD clearance rates. Regional G 7W ratio was between 1.27 to 1.75. The G/W ratio of temporal lobe was lower than the occipital ( P <0.05). The change of regional G/W ratio with time is slow. Conclusion Regional ECD distribution is stable in normal brain. ECD clearance from brain is slow and no significant regional difference.
文摘Earthquakes with magnitudes M ≤ 3.5 were registered in the Andes backarc between ~32.5°S 33.75°S within a temporary experiment from November 2002 to March 2003. Data were collected from 15 seismological broad band stations, deployed above flat subduction section and also above the transitional to normal section of the Nazca plate. Seismic events were located mostly in part of the Southern Precordillera and Cerrilladas Pedemontanas of Mendoza Province. Focal mechanism solutions were obtained, for selected data between15 kmand35 kmdepths, from P wave first motion using FOCMEC software. A band trending NW-NNW of normal focal mechanism earthquakes is located just by the thrust front towards West, and covers the Southern tip of the Southern Precordillera and the Western side of the Cerrilladas Pedemontanas, Mendoza Province, Argentina. Thrust focal mechanism solutions obtained in the present work for events with magnitude less than or equal to 3.5 also show that the thrust front South of ~33.1°S is located in the same place as Mw ≥ 3.6 earthquakes. The most significant findings in this work are these signals of extensional regimen which appear in a compressional subduction tectonic regimen. Nevertheless the short temporal experiment precludes firm interpretations about this particular phenomenon. Probably it is related to a temporary stress relaxation. The normal earthquakes are likely associated to normal faults, and/or to their subsidiaries, that were inverted by contraction and now re-inverted at least transitorily as normal. These faults, which are near and to the East of the suture between Chilenia and Cuyania Paleozoic terranes, were originally involved in the Cuyo Triassic basin formation.
基金National Natural Science Foundation of China (40474023).
文摘The primary results have been obtained by the analyses on the deviation of macroscopic epicenters from relevant microscopic epicenters determined rapidly after the 139 earthquake events occunrred during 1989-2004. Further study has proved the normal distributions exist in both the east and west parts of Chinese mainland partitioned along meridian 105°E. The empirical two-dimensional normal distribution functions for the deviations are presented in the paper. The results are of significance in reducing uncertainty of losses assessment immediately after a destroyed earthquake.
基金supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0600400 and 2016YFA0602500)supported by the Open Research Fund of the Key Laboratory of Tibetan Environmental Changes and Land Surface Processes,Chinese Academy of Sciencesthe National Natural Science Foundation of China(Grant No.41405082)
文摘The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season(SOS)based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer–Normalized Difference Vegetation Index data for 2000–13. We then reconstruct the SOS time series based on the temperature data for 1960–2013.The regional mean SOS shows an advancing trend of 1.42 d(10 yr)during 1960–2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d(10 yr)during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d(10 yr)] during 2000–13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region,during 2000–13.
