Injectable bone cements are used in minimally invasive surgical techniques including vertebroplasty and kyphoplasty.This work is devoted to the development of magnesium-calcium phosphate cements(MCPCs)doped with gadol...Injectable bone cements are used in minimally invasive surgical techniques including vertebroplasty and kyphoplasty.This work is devoted to the development of magnesium-calcium phosphate cements(MCPCs)doped with gadolinium ions(Gd^(3+))for bone defect repair.Interaction between cement powders and a cement liquid resulted in the formation of newberyite and brushite phases,which gave mechanical strength up to 17 MPa without a thermal effect.The introduction of Gd3+into the lattice was confirmed by electron paramagnetic resonance spectroscopy;the doping increased injectivity while giving rise to antibacterial properties against Escherichia coli.Assays of the cement samples soaking in Kokubo’s simulated body fluid revealed the formation of calcium phosphate coatings on the cements’surface.The cements manifested biocompatibility with the MG-63 cell line and significantly enhanced contrast when Gd-MCPC was placed into a bone defect and examined by X-ray micro-computed tomography.For the first time,visualization of a Gd-doped cement material was achieved in a model of a bone defect analyzed by MRI.展开更多
Mixed-oxide nanostructures of the type xGd<sub>2</sub>O<sub>3</sub>-(1-x)α-Fe<sub>2</sub>O<sub>3</sub> (x=0.1, 0.3, 0.5 and 0.7) were synthesized by mechanochemical act...Mixed-oxide nanostructures of the type xGd<sub>2</sub>O<sub>3</sub>-(1-x)α-Fe<sub>2</sub>O<sub>3</sub> (x=0.1, 0.3, 0.5 and 0.7) were synthesized by mechanochemical activation for ball milling times of 0, 2, 4, 8 and 12 hours. The systems were subsequently analyzed by Mӧssbauer spectroscopy, X-ray powder diffraction (XRPD), magnetic measurements and optical diffuse reflectance spectroscopy. The magnetic hyperfine field was studied as function of ball milling time for all sextets involved and found to be consistent with the formation of a limited solid solution in the systems investigated. The end-product was the gadolinium perovskite, represented by a doublet whose abundance was derived as function of the milling time. The XRPD patterns recorded for the equimolar composition were dominated by the diffraction peaks of GdFeO<sub>3</sub> after 12 hours of milling. The hysteresis loops were recorded at 300 and 5 K in an applied magnetic field of 5 T and were interpreted as a superposition of paramagnetic behavior of gadolinium oxide and weak ferromagnetic behavior of hematite and gadolinium perovskite. The Morin transition of hematite was inferred from zero-field-cooling-field-cooling (ZFC-FC) curves measured with a magnetic field of 200 Oe in the 5-300 K temperature range and was found to depend on the ball milling time. Optical diffuse reflectance spectra showed that the compounds were semiconductors with an optical band gap of 2.1 eV.展开更多
BACKGROUND The prognostic value of late gadolinium enhancement(LGE)derived from cardiovascular magnetic resonance(CMR)is well studied,and several new metrics of LGE have emerged.However,some controversies remain;there...BACKGROUND The prognostic value of late gadolinium enhancement(LGE)derived from cardiovascular magnetic resonance(CMR)is well studied,and several new metrics of LGE have emerged.However,some controversies remain;therefore,further discussion is needed,and more precise risk stratification should be explored.AIM To investigate the associations between the positivity,extent,location,and pattern of LGE and multiple outcomes in dilated cardiomyopathy(DCM).METHODS PubMed,Ovid MEDLINE,and Cochrane Library were searched for studies that investigated the prognostic value of LGE in patients with DCM.Pooled hazard ratios(HRs)and 95%confidence intervals were calculated to assess the role of LGE in the risk stratification of DCM.RESULTS Nineteen studies involving 7330 patients with DCM were included in this metaanalysis and covered a wide spectrum of DCM,with a mean left ventricular ejection fraction between 21%and 50%.The meta-analysis revealed that the presence of LGE was associated with an increased risk of multiple adverse outcomes(all-cause mortality,HR:2.14;arrhythmic events,HR:5.12;and composite endpoints,HR:2.38;all P<0.001).Furthermore,every 1%increment in the extent of LGE was associated with an increased risk of all-cause mortality.Analysis of a subgroup revealed that the prognostic value varied based on different location and pattern of LGE.Additionally,we found that LGE was a stronger predictor of arrhythmic events in patients with greater left ventricular ejection fraction.CONCLUSION LGE by CMR in patients with DCM exhibited a substantial value in predicting adverse outcomes,and the extent,location,and pattern of LGE could provide additional information for risk stratification.展开更多
目的探讨3.0 T MRI联合小剂量高浓度对比剂(钆布醇)行对比增强磁共振血管成像(CE-MRA)及动态磁敏感对比增强灌注加权成像(DSC-PWI)对于急性缺血性脑卒中(AIS)患者的应用价值。方法前瞻性纳入临床怀疑AIS且需行CE-MRA及DSC-PWI的患者50例...目的探讨3.0 T MRI联合小剂量高浓度对比剂(钆布醇)行对比增强磁共振血管成像(CE-MRA)及动态磁敏感对比增强灌注加权成像(DSC-PWI)对于急性缺血性脑卒中(AIS)患者的应用价值。方法前瞻性纳入临床怀疑AIS且需行CE-MRA及DSC-PWI的患者50例,随机分为常规浓度组(25例,钆喷酸葡胺0.2 mL/kg)和高浓度组(25例,钆布醇0.06 mL/kg)。比较两组患者的图像质量评分、信号差异、血管狭窄情况及缺血半暗带情况。结果高浓度组与常规浓度组间图像质量评分的差异无统计学意义(3.54±0.32比3.44±0.58;t=0.752,P=0.457)。高浓度组颈总动脉分叉处信号强度(SI)(448.57±180.93)、信噪比(SNR)(196.05±70.86)、对比噪声比(CNR)(183.32±68.08)稍高于常规浓度组(426.99±147.88、189.39±55.89、178.34±53.68),差异无统计学意义(均P>0.05)。高浓度组大脑中动脉起始处SI(393.67±133.02)、SNR(254.61±81.03)、CNR(235.46±77.72)均高于常规浓度组(353.67±139.78、197.78±58.62、183.44±56.52),两组间SI差异无统计学意义(P>0.05),而两组间SNR、CNR的差异均有统计学意义(均P<0.05)。两组CE-MRA诊断动脉狭窄观察者之间一致性均较强(κ=0.763、0.819)。两组DSC-PWI诊断缺血半暗带观察者之间一致性均较强(κ=0.84、0.883)。结论使用小剂量高浓度对比剂行3.0 T MRI是一种可行的急性缺血性脑卒中MRI扫描方案。展开更多
AI coatings with different microstructures were prepared on the surface of Gd using the magnetron sputtering technique to improve its corrosion resistance. The corrosion behaviors for the pure Gd and Gd with Al coatin...AI coatings with different microstructures were prepared on the surface of Gd using the magnetron sputtering technique to improve its corrosion resistance. The corrosion behaviors for the pure Gd and Gd with Al coating in distilled water were studied using the mass loss and electrochemical performance. As a result, pure Gd without coating shows a certain amount of surface cracks under water flow conditions, whereas the polygonal Al coating decreases the path of the corrosive medium to body due to the existence of eroding pits structure. Compared with the polygonal structure Al coating and pure Gd, the lamellar structure of Al coating exhibits a higher electrochemical protection performance （e.g., a lower corrosion current and higher self-corrosion potential） and no occurrence of pitting corrosion. Due to an effective physical shield, the formation of the lamellar structure protected the inner Gd part from being corroded, and prolonged the duration of cathodic protection.展开更多
基金supported by the Russian Science Foundation,grant No.23-63-10056.
文摘Injectable bone cements are used in minimally invasive surgical techniques including vertebroplasty and kyphoplasty.This work is devoted to the development of magnesium-calcium phosphate cements(MCPCs)doped with gadolinium ions(Gd^(3+))for bone defect repair.Interaction between cement powders and a cement liquid resulted in the formation of newberyite and brushite phases,which gave mechanical strength up to 17 MPa without a thermal effect.The introduction of Gd3+into the lattice was confirmed by electron paramagnetic resonance spectroscopy;the doping increased injectivity while giving rise to antibacterial properties against Escherichia coli.Assays of the cement samples soaking in Kokubo’s simulated body fluid revealed the formation of calcium phosphate coatings on the cements’surface.The cements manifested biocompatibility with the MG-63 cell line and significantly enhanced contrast when Gd-MCPC was placed into a bone defect and examined by X-ray micro-computed tomography.For the first time,visualization of a Gd-doped cement material was achieved in a model of a bone defect analyzed by MRI.
文摘Mixed-oxide nanostructures of the type xGd<sub>2</sub>O<sub>3</sub>-(1-x)α-Fe<sub>2</sub>O<sub>3</sub> (x=0.1, 0.3, 0.5 and 0.7) were synthesized by mechanochemical activation for ball milling times of 0, 2, 4, 8 and 12 hours. The systems were subsequently analyzed by Mӧssbauer spectroscopy, X-ray powder diffraction (XRPD), magnetic measurements and optical diffuse reflectance spectroscopy. The magnetic hyperfine field was studied as function of ball milling time for all sextets involved and found to be consistent with the formation of a limited solid solution in the systems investigated. The end-product was the gadolinium perovskite, represented by a doublet whose abundance was derived as function of the milling time. The XRPD patterns recorded for the equimolar composition were dominated by the diffraction peaks of GdFeO<sub>3</sub> after 12 hours of milling. The hysteresis loops were recorded at 300 and 5 K in an applied magnetic field of 5 T and were interpreted as a superposition of paramagnetic behavior of gadolinium oxide and weak ferromagnetic behavior of hematite and gadolinium perovskite. The Morin transition of hematite was inferred from zero-field-cooling-field-cooling (ZFC-FC) curves measured with a magnetic field of 200 Oe in the 5-300 K temperature range and was found to depend on the ball milling time. Optical diffuse reflectance spectra showed that the compounds were semiconductors with an optical band gap of 2.1 eV.
基金the Research Grant of the National Natural Science Foundation of China,No.81801674Sichuan Province Science and Technology Support Program,No.2021YJ0242.
文摘BACKGROUND The prognostic value of late gadolinium enhancement(LGE)derived from cardiovascular magnetic resonance(CMR)is well studied,and several new metrics of LGE have emerged.However,some controversies remain;therefore,further discussion is needed,and more precise risk stratification should be explored.AIM To investigate the associations between the positivity,extent,location,and pattern of LGE and multiple outcomes in dilated cardiomyopathy(DCM).METHODS PubMed,Ovid MEDLINE,and Cochrane Library were searched for studies that investigated the prognostic value of LGE in patients with DCM.Pooled hazard ratios(HRs)and 95%confidence intervals were calculated to assess the role of LGE in the risk stratification of DCM.RESULTS Nineteen studies involving 7330 patients with DCM were included in this metaanalysis and covered a wide spectrum of DCM,with a mean left ventricular ejection fraction between 21%and 50%.The meta-analysis revealed that the presence of LGE was associated with an increased risk of multiple adverse outcomes(all-cause mortality,HR:2.14;arrhythmic events,HR:5.12;and composite endpoints,HR:2.38;all P<0.001).Furthermore,every 1%increment in the extent of LGE was associated with an increased risk of all-cause mortality.Analysis of a subgroup revealed that the prognostic value varied based on different location and pattern of LGE.Additionally,we found that LGE was a stronger predictor of arrhythmic events in patients with greater left ventricular ejection fraction.CONCLUSION LGE by CMR in patients with DCM exhibited a substantial value in predicting adverse outcomes,and the extent,location,and pattern of LGE could provide additional information for risk stratification.
文摘目的探讨3.0 T MRI联合小剂量高浓度对比剂(钆布醇)行对比增强磁共振血管成像(CE-MRA)及动态磁敏感对比增强灌注加权成像(DSC-PWI)对于急性缺血性脑卒中(AIS)患者的应用价值。方法前瞻性纳入临床怀疑AIS且需行CE-MRA及DSC-PWI的患者50例,随机分为常规浓度组(25例,钆喷酸葡胺0.2 mL/kg)和高浓度组(25例,钆布醇0.06 mL/kg)。比较两组患者的图像质量评分、信号差异、血管狭窄情况及缺血半暗带情况。结果高浓度组与常规浓度组间图像质量评分的差异无统计学意义(3.54±0.32比3.44±0.58;t=0.752,P=0.457)。高浓度组颈总动脉分叉处信号强度(SI)(448.57±180.93)、信噪比(SNR)(196.05±70.86)、对比噪声比(CNR)(183.32±68.08)稍高于常规浓度组(426.99±147.88、189.39±55.89、178.34±53.68),差异无统计学意义(均P>0.05)。高浓度组大脑中动脉起始处SI(393.67±133.02)、SNR(254.61±81.03)、CNR(235.46±77.72)均高于常规浓度组(353.67±139.78、197.78±58.62、183.44±56.52),两组间SI差异无统计学意义(P>0.05),而两组间SNR、CNR的差异均有统计学意义(均P<0.05)。两组CE-MRA诊断动脉狭窄观察者之间一致性均较强(κ=0.763、0.819)。两组DSC-PWI诊断缺血半暗带观察者之间一致性均较强(κ=0.84、0.883)。结论使用小剂量高浓度对比剂行3.0 T MRI是一种可行的急性缺血性脑卒中MRI扫描方案。
基金Project(BK2012463)supported by the Natural Science Foundation of Jiangsu Province of ChinaProject(51245010)supported by Special Funds of the National Natural Science Foundation of China+1 种基金Project(11047143)supported by the National Natural Science Foundation of ChinaProjects(12KF069,12KF036)supported by Opening Found of Laboratory of Nanjing University of Information Science and Technology,China
文摘AI coatings with different microstructures were prepared on the surface of Gd using the magnetron sputtering technique to improve its corrosion resistance. The corrosion behaviors for the pure Gd and Gd with Al coating in distilled water were studied using the mass loss and electrochemical performance. As a result, pure Gd without coating shows a certain amount of surface cracks under water flow conditions, whereas the polygonal Al coating decreases the path of the corrosive medium to body due to the existence of eroding pits structure. Compared with the polygonal structure Al coating and pure Gd, the lamellar structure of Al coating exhibits a higher electrochemical protection performance （e.g., a lower corrosion current and higher self-corrosion potential） and no occurrence of pitting corrosion. Due to an effective physical shield, the formation of the lamellar structure protected the inner Gd part from being corroded, and prolonged the duration of cathodic protection.
