MnZn-doped W-type barium cobalt ferrite powder composites of Ba(MnZn)xCo2(1-x)Fe16O27 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) were prepared in a sol-gel process. The microwave absorbing properties of the composites in the r...MnZn-doped W-type barium cobalt ferrite powder composites of Ba(MnZn)xCo2(1-x)Fe16O27 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) were prepared in a sol-gel process. The microwave absorbing properties of the composites in the range of 2 - 18 GHz and their electromagnetic loss mechanisms were studied. The results demonstrated that the synthesized Ba(MnZn)xCo2(1-x)Fe16O27 samples possess a W-type phase of the crystal structure with a hexagonal flaky shape in micro-morphology, and the samples exhibited a soft magnetic trait that enables improving their microwave absorption properties through suitable MnZn doping. For Ba(MnZn)0.4Co1.2Fe16O27 with a thickness of 2.8 mm, the reflection loss peak was -40.7 dB at a frequency of 7.3 GHz, with a bandwidth of 6.6 GHz at a loss of less than -10 dB. The microwave absorption primarily resulted from magnetic losses caused by magnetization relaxation, domain wall resonance, and natural resonance.展开更多
Acute myocardial infarction(AMI)is a life-threatening disease when sudden blockage of coronary artery occurs.As the most specific biomarker,cardiac troponin I(cTnI)is usually checked separately to diagnose or eliminat...Acute myocardial infarction(AMI)is a life-threatening disease when sudden blockage of coronary artery occurs.As the most specific biomarker,cardiac troponin I(cTnI)is usually checked separately to diagnose or eliminate AMI,and achieving the accurate detection of cTnI is of great significance to patients'life and health.Compared with other methods,fluorescent detection has the advantages of simple operation,high sensitivity and wide applicability.However,due to the strong fluorescence interference of biological molecules in body fluids,it is often difficult to obtain high sensitivity.In order to solve this problem,in this study,surface acoustic wave separation is designed to purify the target to achieve more sensitive detection performance of fluorescent detection.Specifically,the interference of background noise is almost completely removed on a microfluidic chip by isolating microbeads through acoustic radiation force,on which the biomarkers are captured by the immobilized detection probe.And then,the concentration of cTnI in human serum is detected by the fluorescence intensity change of the isolated functionalized beads.By this way,the detection limit of our biosensor calculated by 3σ/K method is 44 pg/mL and 0.34 ng/mL in PBS buffer and human serum respectively.Finally,the reliability of this method has been validated by comparison with clinical tests from the nephelometric analyzer in hospital.展开更多
文摘MnZn-doped W-type barium cobalt ferrite powder composites of Ba(MnZn)xCo2(1-x)Fe16O27 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) were prepared in a sol-gel process. The microwave absorbing properties of the composites in the range of 2 - 18 GHz and their electromagnetic loss mechanisms were studied. The results demonstrated that the synthesized Ba(MnZn)xCo2(1-x)Fe16O27 samples possess a W-type phase of the crystal structure with a hexagonal flaky shape in micro-morphology, and the samples exhibited a soft magnetic trait that enables improving their microwave absorption properties through suitable MnZn doping. For Ba(MnZn)0.4Co1.2Fe16O27 with a thickness of 2.8 mm, the reflection loss peak was -40.7 dB at a frequency of 7.3 GHz, with a bandwidth of 6.6 GHz at a loss of less than -10 dB. The microwave absorption primarily resulted from magnetic losses caused by magnetization relaxation, domain wall resonance, and natural resonance.
基金financially supported by the National Key R&D Program of China(2022YFC2406600,2020YFB2009000)Program for Innovation Team of Shaanxi Province(2021TD-23).
文摘Acute myocardial infarction(AMI)is a life-threatening disease when sudden blockage of coronary artery occurs.As the most specific biomarker,cardiac troponin I(cTnI)is usually checked separately to diagnose or eliminate AMI,and achieving the accurate detection of cTnI is of great significance to patients'life and health.Compared with other methods,fluorescent detection has the advantages of simple operation,high sensitivity and wide applicability.However,due to the strong fluorescence interference of biological molecules in body fluids,it is often difficult to obtain high sensitivity.In order to solve this problem,in this study,surface acoustic wave separation is designed to purify the target to achieve more sensitive detection performance of fluorescent detection.Specifically,the interference of background noise is almost completely removed on a microfluidic chip by isolating microbeads through acoustic radiation force,on which the biomarkers are captured by the immobilized detection probe.And then,the concentration of cTnI in human serum is detected by the fluorescence intensity change of the isolated functionalized beads.By this way,the detection limit of our biosensor calculated by 3σ/K method is 44 pg/mL and 0.34 ng/mL in PBS buffer and human serum respectively.Finally,the reliability of this method has been validated by comparison with clinical tests from the nephelometric analyzer in hospital.
