This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well ...This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well the Atlantic Water core temperature (AWCT) in the Arctic Ocean and shows that four largest decadalscale warming episodes occurred in the 1930s, 70s, 80s, and 90s, in agreement with the hydrographic observational data. The difference is that there was no pre-warming prior to the 1930s episode, while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s, leading the 1990s into the largest and prolonged warming in the 20th century. Over the last century, the simulated heat transport via Fram Strait and the Barents Sea was estimated to be, on average, 31.32 TW and 14.82 TW, respectively, while the Bering Strait also provides 15.94 TW heat into the west- ern Arctic Ocean. Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT ( C = 0.75 ) at 0- lag. The modeled North Atlantic Oscillation (NAO) index has a significant correlation with the heat transport ( C = 0.37 ). The observed AWCT has a significant correlation with both the modeled AWCT ( C =0.49) and the heat transport ( C =0.41 ). However, the modeled NAO index does not significantly correlate with either the observed AWCT ( C = 0.03 ) or modeled AWCT ( C = 0.16 ) at a zero-lag, indicating that the Arctic climate system is far more complex than expected.展开更多
Background: Determination of cyclosporine A (CsA) and tacrolimus (Tac) in dried blood spots (DBS) could enable drug monitoring in transplanted patients without the necessity of having to take venous blood samples. The...Background: Determination of cyclosporine A (CsA) and tacrolimus (Tac) in dried blood spots (DBS) could enable drug monitoring in transplanted patients without the necessity of having to take venous blood samples. Therefore, we have developed a method for quantitative determination of calcineurin inhibitors (CNI) by liquid-chromatography-tandem mass spectrometry (LCMS). Methods: In a study with 68 kidney transplant recipients (KTR, 34 CsA, 34 Tac), we tested the clinical application of LCMS monitoring in DBS in comparison to LCMS in whole blood. Results: The measuring range is proven for 27.33 to 1345 ng/ml for CsA and for 1.63 to 39.7 ng/ml for Tac. The requirements for clinical chemical analyses for precision and accuracy are complied with. Stability is documented for a period of 14 days. The study showed the following deviations from LCMS in whole blood for determination of CsA and Tac in DBS after introducing a correction factor by the haematocrit (Hct) value (CsA trough level: mean = 4.7%, ±1.96 standard deviation (SD) -52.1% to 61.4%, N = 96;CsA peak level: mean = 7.3%, ±1.96 SD -39.7% to 54.4%, N = 95;Tac trough level: mean = -0.5%, ±1.96 SD -76.4% to 75.3%, N = 88;Tac peak level: mean = 3.9%, ±1.96 SD -80.1% to 88.7%, N = 92). Conclusions: Our data show comparable results with the reference method by means of LCMS in whole blood. Therefore, DBS of KTR for determination of CNI levels could be transported on filter cards by mail to the respective laboratory resistant to breakage and the hazard of infection.展开更多
基金supported by the Frontier Research Center for Global Change and International Arctic Research Center,through JAMSTEC,JapanThe climate model was run on the Earth Simulator of JAMSTEC,Yokohama,Japan+1 种基金Constructive discussions with Drs.T.Matsuno,T.Tokioka and N.Suginohara of FRCGC/JAMSTEC andDr.A.Sumi of CCSR/UT are very much appreciatedJW also thanks NOAA Office of Arctic Research for partial support.This is GLERL Contribution No.1496.
文摘This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well the Atlantic Water core temperature (AWCT) in the Arctic Ocean and shows that four largest decadalscale warming episodes occurred in the 1930s, 70s, 80s, and 90s, in agreement with the hydrographic observational data. The difference is that there was no pre-warming prior to the 1930s episode, while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s, leading the 1990s into the largest and prolonged warming in the 20th century. Over the last century, the simulated heat transport via Fram Strait and the Barents Sea was estimated to be, on average, 31.32 TW and 14.82 TW, respectively, while the Bering Strait also provides 15.94 TW heat into the west- ern Arctic Ocean. Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT ( C = 0.75 ) at 0- lag. The modeled North Atlantic Oscillation (NAO) index has a significant correlation with the heat transport ( C = 0.37 ). The observed AWCT has a significant correlation with both the modeled AWCT ( C =0.49) and the heat transport ( C =0.41 ). However, the modeled NAO index does not significantly correlate with either the observed AWCT ( C = 0.03 ) or modeled AWCT ( C = 0.16 ) at a zero-lag, indicating that the Arctic climate system is far more complex than expected.
文摘Background: Determination of cyclosporine A (CsA) and tacrolimus (Tac) in dried blood spots (DBS) could enable drug monitoring in transplanted patients without the necessity of having to take venous blood samples. Therefore, we have developed a method for quantitative determination of calcineurin inhibitors (CNI) by liquid-chromatography-tandem mass spectrometry (LCMS). Methods: In a study with 68 kidney transplant recipients (KTR, 34 CsA, 34 Tac), we tested the clinical application of LCMS monitoring in DBS in comparison to LCMS in whole blood. Results: The measuring range is proven for 27.33 to 1345 ng/ml for CsA and for 1.63 to 39.7 ng/ml for Tac. The requirements for clinical chemical analyses for precision and accuracy are complied with. Stability is documented for a period of 14 days. The study showed the following deviations from LCMS in whole blood for determination of CsA and Tac in DBS after introducing a correction factor by the haematocrit (Hct) value (CsA trough level: mean = 4.7%, ±1.96 standard deviation (SD) -52.1% to 61.4%, N = 96;CsA peak level: mean = 7.3%, ±1.96 SD -39.7% to 54.4%, N = 95;Tac trough level: mean = -0.5%, ±1.96 SD -76.4% to 75.3%, N = 88;Tac peak level: mean = 3.9%, ±1.96 SD -80.1% to 88.7%, N = 92). Conclusions: Our data show comparable results with the reference method by means of LCMS in whole blood. Therefore, DBS of KTR for determination of CNI levels could be transported on filter cards by mail to the respective laboratory resistant to breakage and the hazard of infection.