A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The...A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The obtained U-Pb ages for zircon standards GJ-1,TEMORA and SK10-2 are consistent with the preferred values within about 1% uncertainty (2σ) by simple external calibration against zircon standard 91500.Different data reduction softwares could yield different uncertainties for calculation of U-Pb ages.The commercially available program GLITTER4.4 could apply an improper uncertainty calculation strategy,but it may yield artificial high precisions for single analyses.Our trace element analyses indicate that Si is not an ideal internal standard for zircon when calibrated against the NIST glasses.Calibration against the NIST glasses using Si as an internal standard,a systematic deviation of 10% 30% was found for most trace elements including Zr.However,the trace element compositions of zircon can be accurately measured by calibration against multiple reference materials with natural compositions (e.g.,BCR-2G,BHVO-2G and BIR-1G),or calibration against NIST SRM 610 and using Zr as an internal standard.Analyses of two pieces of GJ-1 demonstrate that it is relatively homogenous for most trace elements (except for Ti).展开更多
AIM:To compare the incidence of early portal or splenic vein thrombosis(PSVT) in patients treated with irregular and regular anticoagulantion after splenectomy with gastroesophageal devascularization.METHODS:We retros...AIM:To compare the incidence of early portal or splenic vein thrombosis(PSVT) in patients treated with irregular and regular anticoagulantion after splenectomy with gastroesophageal devascularization.METHODS:We retrospectively analyzed 301 patients who underwent splenectomy with gastroesophageal devascularization for portal hypertension due to cirrhosis between April 2004 and July 2010.Patients were categorized into group A with irregular anticoagulation and group B with regular anticoagulation,respectively.Group A(153 patients) received anticoagulant monotherapy for an undesignated time period or with aspirin or warfarin without low-molecular-weight heparin(LMWH) irregularly.Group B(148 patients) received subcutaneous injection of LMWH routinely within the first 5 d after surgery,followed by oral warfarin and aspirin for one month regularly.The target prothrombin time/international normalized ratio(PT/INR) was 1.25-1.50.Platelet and PT/INR were monitored.Color Doppler imaging was performed to monitor PSVT as well as the effectiveness of thrombolytic therapy.RESULTS:The patients' data were collected and analyzed retrospectively.Among the patients,94 developed early postoperative mural PSVT,including 63 patients in group A(63/153,41.17%) and 31 patients in group B(31/148,20.94%).There were 50(32.67%) patients in group A and 27(18.24%) in group B with mural PSVT in the main trunk of portal vein.After the administration of thrombolytic,anticoagulant and antiaggregation therapy,complete or partial thrombus dissolution achieved in 50(79.37%) in group A and 26(83.87%) in group B.CONCLUSION:Regular anticoagulation therapy can reduce the incidence of PSVT in patients who undergo splenectomy with gastroesophageal devascularization,and regular anticoagulant therapy is safer and more effective than irregular anticoagulant therapy.Early and timely thrombolytic therapy is imperative and feasible for the prevention of PSVT.展开更多
基金supported by the National Natural Science Foundation of China (GrantNos. 40821061,90914007,40576030 and 90714010)the State Administration of Foreign Expert Affairs of China (Grant No. B07039)the Special Fund for Basic Scientific Research of Central Colleges,China University of Geosciences
文摘A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The obtained U-Pb ages for zircon standards GJ-1,TEMORA and SK10-2 are consistent with the preferred values within about 1% uncertainty (2σ) by simple external calibration against zircon standard 91500.Different data reduction softwares could yield different uncertainties for calculation of U-Pb ages.The commercially available program GLITTER4.4 could apply an improper uncertainty calculation strategy,but it may yield artificial high precisions for single analyses.Our trace element analyses indicate that Si is not an ideal internal standard for zircon when calibrated against the NIST glasses.Calibration against the NIST glasses using Si as an internal standard,a systematic deviation of 10% 30% was found for most trace elements including Zr.However,the trace element compositions of zircon can be accurately measured by calibration against multiple reference materials with natural compositions (e.g.,BCR-2G,BHVO-2G and BIR-1G),or calibration against NIST SRM 610 and using Zr as an internal standard.Analyses of two pieces of GJ-1 demonstrate that it is relatively homogenous for most trace elements (except for Ti).
基金Supported by Grants from Beijing Municipal Health Bureau,No.2011-2-18
文摘AIM:To compare the incidence of early portal or splenic vein thrombosis(PSVT) in patients treated with irregular and regular anticoagulantion after splenectomy with gastroesophageal devascularization.METHODS:We retrospectively analyzed 301 patients who underwent splenectomy with gastroesophageal devascularization for portal hypertension due to cirrhosis between April 2004 and July 2010.Patients were categorized into group A with irregular anticoagulation and group B with regular anticoagulation,respectively.Group A(153 patients) received anticoagulant monotherapy for an undesignated time period or with aspirin or warfarin without low-molecular-weight heparin(LMWH) irregularly.Group B(148 patients) received subcutaneous injection of LMWH routinely within the first 5 d after surgery,followed by oral warfarin and aspirin for one month regularly.The target prothrombin time/international normalized ratio(PT/INR) was 1.25-1.50.Platelet and PT/INR were monitored.Color Doppler imaging was performed to monitor PSVT as well as the effectiveness of thrombolytic therapy.RESULTS:The patients' data were collected and analyzed retrospectively.Among the patients,94 developed early postoperative mural PSVT,including 63 patients in group A(63/153,41.17%) and 31 patients in group B(31/148,20.94%).There were 50(32.67%) patients in group A and 27(18.24%) in group B with mural PSVT in the main trunk of portal vein.After the administration of thrombolytic,anticoagulant and antiaggregation therapy,complete or partial thrombus dissolution achieved in 50(79.37%) in group A and 26(83.87%) in group B.CONCLUSION:Regular anticoagulation therapy can reduce the incidence of PSVT in patients who undergo splenectomy with gastroesophageal devascularization,and regular anticoagulant therapy is safer and more effective than irregular anticoagulant therapy.Early and timely thrombolytic therapy is imperative and feasible for the prevention of PSVT.
