Offset-tracking is an essential method for deriving glacier flow rates using optical imagery.Sentinel-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial ...Offset-tracking is an essential method for deriving glacier flow rates using optical imagery.Sentinel-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial resolution with relatively short revisit time,wide swath width,and free accessibility.To evaluate and compare the precision of offset-tracking results yielded with these two kinds of data,in this study S2 and L8/9 imagery observed in Petermann Glacier in Greenland,Karakoram in High-Mountains Asia,and Amery Ice Shelf in the Antarctic are analyzed.Outliers and various systematic error sources in the offset-tracking results including orbital and strip errors were analyzed and eliminated at the pre-process stage.Precision at the off-glacier(bare rock)region was evaluated by presuming that no deformation occurred;then for both glacierized and the off-glacier regions,precision of velocity time series was evaluated based on error propagation theory.The least squares method based on connected components was used to solve flow rates time series based on multi-pair images offset-tracking.The results indicated that S2 achieved slightly higher precision than L8/9 in terms of both single-pair derived displacements and least square solved daily flow rates time series.Generally,the RMSE of daily velocity is 26%lower for S2 than L8/9.Moreover,S2 provided higher temporal resolution for monitoring glacier flow rates.展开更多
目的探讨2型糖尿病患者冠状动脉钙化(coronary arterial calcification,CAC)与骨质疏松症指标的相关性。方法根据冠脉钙化积分将200例2型糖尿病患者分成冠脉钙化组和对照组,分别记录一般资料,检测血糖、血脂、钙、磷、碱性磷酸酶(alkali...目的探讨2型糖尿病患者冠状动脉钙化(coronary arterial calcification,CAC)与骨质疏松症指标的相关性。方法根据冠脉钙化积分将200例2型糖尿病患者分成冠脉钙化组和对照组,分别记录一般资料,检测血糖、血脂、钙、磷、碱性磷酸酶(alkaline phosphatase,ALP)、N端中段骨钙素(molecular fragment of osteocalcin N terminal,N-MID)、I型胶原羧基端肽交联(β-cross-linked C-telopeptide of type I collagen,β-CTX)等生化指标,同时进行骨密度(bone mineral density,BMD)和冠脉增强CT等检查,探寻BMD、骨代谢指标与CAC等指标是否存在相关性。在此基础上,进一步对冠脉钙化组患者检测指标进行相关性分析。依据冠脉增强CT结果将受试者分为冠脉狭窄组和无冠脉狭窄组,进一步探讨2型糖尿病患者冠脉狭窄与骨质疏松症的关系。结果冠脉钙化组的年龄、ALP、腰围、体质量指数(body mass index,BMI)、空腹血糖(fasting blood glucose,FBG)高于对照组,差异有统计学意义(P<0.05)。BMD及骨代谢指标组间比较差异无统计学意义(P>0.05)。相关性分析表明,磷、25(OH)D 3、β-CTX、甲状旁腺素(parathyroid hormone,PTH)与腰椎、髋部BMD均为负相关(P<0.05);有无冠心病既往史与腰椎BMD为正相关(P<0.05),绝经年限与腰椎BMD为负相关(P<0.05);年龄、绝经年限、收缩压、HDL-C、HOMA-IS与髋部BMD均为负相关(P<0.05)。CAC与各指标的Logistic回归分析表明,冠脉是否钙化与有无冠脉狭窄、有无冠心病既往史、有无颈动脉粥样硬化显著相关(P<0.05)。冠脉狭窄与各指标的Logistic回归分析显示,冠脉是否狭窄与有无冠脉钙化、有无冠心病既往史之间显著相关(P<0.05)。结论冠脉狭窄与腰椎BMD相关,冠脉钙化与冠脉狭窄显著相关;冠脉狭窄、冠心病既往史、颈动脉粥样硬化是冠脉钙化的危险因素,冠脉钙化是冠心病的致病危险因素。2型糖尿病患者控制血糖、防治骨质疏松症的发生或可降低冠心病的发生风险。展开更多
目的评价脊髓水平程序性死亡配体1(programmed cell death ligand-1,PD-L1)在骨癌痛小鼠模型中的作用。方法SPF级雄性C3H/HeJ小鼠96只,4~6周龄,体质量20~25g,采用右侧股骨远端骨髓腔接种NCTC2472纤维肉瘤细胞制备小鼠骨癌痛模型。第一...目的评价脊髓水平程序性死亡配体1(programmed cell death ligand-1,PD-L1)在骨癌痛小鼠模型中的作用。方法SPF级雄性C3H/HeJ小鼠96只,4~6周龄,体质量20~25g,采用右侧股骨远端骨髓腔接种NCTC2472纤维肉瘤细胞制备小鼠骨癌痛模型。第一部分实验:C3H/HeJ雄性小鼠64只,采用随机数字表法分为两组(n=32):假手术组(Sham组)和骨癌痛组(Tumor组)。第二部分实验:C3H/HeJ雄性小鼠32只,采用随机数字表法分为四组(每组n=8):骨癌痛组(T组)、骨癌痛+鞘内注射PD-L1组(PD-L1组)、骨癌痛+鞘内注射生理盐水组(NS组)和假手术组(S组)。Sham组和Tumor组分别于接种前、接种后4、7、10、14、21d时进行痛行为学测量,包括机械缩足阈值(PWMT)和自发抬足次数(NSF),每组于各时点随机处死4只小鼠取脊髓腰膨大,Westernblot检测PD-L1的表达。接种瘤细胞后14d,PD-L1组和NS组小鼠分别单次鞘内注射PD-L11μg/5μl和生理盐水5μl。T组、PD-L1组、NS组和S组于接种后14d、给药前、给药后2、4、6、24h时测定小鼠PWMT和NSF。结果与Sham组比较,Tumor组接种后7~21dPMWT降低,NSF增加(P<0.05)。与接种前和Sham组比较[接种前(0.38±0.06)、Sham组:10d(0.35±0.08)、14d(0.38±0.08)、21d(0.36±0.07)],Tumor组接种后10d,14d,21d脊髓水平PD-L1表达上调[(0.77±0.06)、(1.21±0.04)、(1.18±0.06)](均P<0.05)。与NS组比较,PD-L1组给药后2~6h时PWMT升高[NS组(0.25±0.12)g、(0.25±0.12)g、(0.31±0.12)g,PD-L1组(1.43±0.49)g、(1.35±0.44)g、(0.95±0.26)g],NSF减少[NS组(11.74±1.31)次、(13.78±0.0.91)次、(13.63±1.06)次,PD-L1组(4.90±0.82)次、(4.15±0.71)次、(7.65±0.56)次](P<0.05),直至24h基本恢复正常。结论小鼠接种肿瘤细胞后脊髓水平PD-L1表达增加,且鞘内注射PD-L1可减轻骨癌痛模型小鼠的疼痛。展开更多
基金supported by the National Natural Science Foundation of China(Grant no.42371136)the Guangdong Basic and Applied Basic Research Foundation(Grant no.2021B1515020032)the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant no.311022003).
文摘Offset-tracking is an essential method for deriving glacier flow rates using optical imagery.Sentinel-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial resolution with relatively short revisit time,wide swath width,and free accessibility.To evaluate and compare the precision of offset-tracking results yielded with these two kinds of data,in this study S2 and L8/9 imagery observed in Petermann Glacier in Greenland,Karakoram in High-Mountains Asia,and Amery Ice Shelf in the Antarctic are analyzed.Outliers and various systematic error sources in the offset-tracking results including orbital and strip errors were analyzed and eliminated at the pre-process stage.Precision at the off-glacier(bare rock)region was evaluated by presuming that no deformation occurred;then for both glacierized and the off-glacier regions,precision of velocity time series was evaluated based on error propagation theory.The least squares method based on connected components was used to solve flow rates time series based on multi-pair images offset-tracking.The results indicated that S2 achieved slightly higher precision than L8/9 in terms of both single-pair derived displacements and least square solved daily flow rates time series.Generally,the RMSE of daily velocity is 26%lower for S2 than L8/9.Moreover,S2 provided higher temporal resolution for monitoring glacier flow rates.
文摘目的探讨2型糖尿病患者冠状动脉钙化(coronary arterial calcification,CAC)与骨质疏松症指标的相关性。方法根据冠脉钙化积分将200例2型糖尿病患者分成冠脉钙化组和对照组,分别记录一般资料,检测血糖、血脂、钙、磷、碱性磷酸酶(alkaline phosphatase,ALP)、N端中段骨钙素(molecular fragment of osteocalcin N terminal,N-MID)、I型胶原羧基端肽交联(β-cross-linked C-telopeptide of type I collagen,β-CTX)等生化指标,同时进行骨密度(bone mineral density,BMD)和冠脉增强CT等检查,探寻BMD、骨代谢指标与CAC等指标是否存在相关性。在此基础上,进一步对冠脉钙化组患者检测指标进行相关性分析。依据冠脉增强CT结果将受试者分为冠脉狭窄组和无冠脉狭窄组,进一步探讨2型糖尿病患者冠脉狭窄与骨质疏松症的关系。结果冠脉钙化组的年龄、ALP、腰围、体质量指数(body mass index,BMI)、空腹血糖(fasting blood glucose,FBG)高于对照组,差异有统计学意义(P<0.05)。BMD及骨代谢指标组间比较差异无统计学意义(P>0.05)。相关性分析表明,磷、25(OH)D 3、β-CTX、甲状旁腺素(parathyroid hormone,PTH)与腰椎、髋部BMD均为负相关(P<0.05);有无冠心病既往史与腰椎BMD为正相关(P<0.05),绝经年限与腰椎BMD为负相关(P<0.05);年龄、绝经年限、收缩压、HDL-C、HOMA-IS与髋部BMD均为负相关(P<0.05)。CAC与各指标的Logistic回归分析表明,冠脉是否钙化与有无冠脉狭窄、有无冠心病既往史、有无颈动脉粥样硬化显著相关(P<0.05)。冠脉狭窄与各指标的Logistic回归分析显示,冠脉是否狭窄与有无冠脉钙化、有无冠心病既往史之间显著相关(P<0.05)。结论冠脉狭窄与腰椎BMD相关,冠脉钙化与冠脉狭窄显著相关;冠脉狭窄、冠心病既往史、颈动脉粥样硬化是冠脉钙化的危险因素,冠脉钙化是冠心病的致病危险因素。2型糖尿病患者控制血糖、防治骨质疏松症的发生或可降低冠心病的发生风险。
文摘目的评价脊髓水平程序性死亡配体1(programmed cell death ligand-1,PD-L1)在骨癌痛小鼠模型中的作用。方法SPF级雄性C3H/HeJ小鼠96只,4~6周龄,体质量20~25g,采用右侧股骨远端骨髓腔接种NCTC2472纤维肉瘤细胞制备小鼠骨癌痛模型。第一部分实验:C3H/HeJ雄性小鼠64只,采用随机数字表法分为两组(n=32):假手术组(Sham组)和骨癌痛组(Tumor组)。第二部分实验:C3H/HeJ雄性小鼠32只,采用随机数字表法分为四组(每组n=8):骨癌痛组(T组)、骨癌痛+鞘内注射PD-L1组(PD-L1组)、骨癌痛+鞘内注射生理盐水组(NS组)和假手术组(S组)。Sham组和Tumor组分别于接种前、接种后4、7、10、14、21d时进行痛行为学测量,包括机械缩足阈值(PWMT)和自发抬足次数(NSF),每组于各时点随机处死4只小鼠取脊髓腰膨大,Westernblot检测PD-L1的表达。接种瘤细胞后14d,PD-L1组和NS组小鼠分别单次鞘内注射PD-L11μg/5μl和生理盐水5μl。T组、PD-L1组、NS组和S组于接种后14d、给药前、给药后2、4、6、24h时测定小鼠PWMT和NSF。结果与Sham组比较,Tumor组接种后7~21dPMWT降低,NSF增加(P<0.05)。与接种前和Sham组比较[接种前(0.38±0.06)、Sham组:10d(0.35±0.08)、14d(0.38±0.08)、21d(0.36±0.07)],Tumor组接种后10d,14d,21d脊髓水平PD-L1表达上调[(0.77±0.06)、(1.21±0.04)、(1.18±0.06)](均P<0.05)。与NS组比较,PD-L1组给药后2~6h时PWMT升高[NS组(0.25±0.12)g、(0.25±0.12)g、(0.31±0.12)g,PD-L1组(1.43±0.49)g、(1.35±0.44)g、(0.95±0.26)g],NSF减少[NS组(11.74±1.31)次、(13.78±0.0.91)次、(13.63±1.06)次,PD-L1组(4.90±0.82)次、(4.15±0.71)次、(7.65±0.56)次](P<0.05),直至24h基本恢复正常。结论小鼠接种肿瘤细胞后脊髓水平PD-L1表达增加,且鞘内注射PD-L1可减轻骨癌痛模型小鼠的疼痛。
