When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with bias.Because of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a ...When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with bias.Because of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a reciprocating symmetrical dynamic flow test.Since the traditional differential pressure flowmeter is affected by viscosity and inertia of the fluid,it is only suitable for measuring steady flow.Therefore,a new type of double pressure differential dynamic flowmeter is designed to improve the traditional differential pressure flowmeter.The influence of fluid viscosity and inertia in the flow process are negated by subtracting the differential pressure in section expansion from the differential pressure in section contraction.The double differential pressure flowmeter is modeled and a flow meter prototype is designed.Then,the flow coefficients are identified and corrected by a practical test.Finally,the dynamic performance and steady-state precision of the flowmeter are verified by comparing with the test results of the no-load hydraulic cylinder.The double differential pressure dynamic flowmeter is proven to measure dynamic flow accurately,especially at higher dynamic frequencies.展开更多
Background: In the last decade, sodium mag-netic resonance imaging was investigated for its potential as a functional cardiac imaging tool for ischemia. Later interest was developed in contrast enhancement for intrace...Background: In the last decade, sodium mag-netic resonance imaging was investigated for its potential as a functional cardiac imaging tool for ischemia. Later interest was developed in contrast enhancement for intracellular sodium. Little success was reported to suppress extracellular sodium resulting in the intracellular sodium MRI image acquisition using quantum filters or sodium transition states as contrast properties. Now its clinical application is ex-panding as a new challenge in brain and other cancer tumors. Contrast enhancement: We highlight the physical principles of sodium MRI in three different pulse sequences using filters (single quantum, multiple quantum, and triple quantum) meant for sodium contrast enhancement. The optimization of scan parameters, i.e. times of echo delay (TE), inversion recovery (TI) periods, and utility of Dysprosium (DyPPP) shift contrast agents, enhances contrast in sodium MRI images. Inversion recovery pulse sequence without any shift reagent measures the intracellular sodium concentration to evaluate ischemia, apoptosis and membrane integrity. Membrane integrity loss, apoptosis and malignancy are results of growth factor loss and poor epithelial capability related with MRI visible intracellular sodium concentration. Applications and limitations: The sodium MR imaging technical advances reduced scan time to distinguish intracellular and extracellular sodium signals in malignant tumors by use of quantum filter techniques to generate 3D sodium images without shift regents. We observed the association of malignancy with increased TSC, and reduced apoptosis and epithelial growth factor in breast cancer cells. The validity is still in question. Conclusion: Different modified sodium MRI pulse sequences are research tools of sodium contrast enhancement in brain, cardiac and tumor imaging. The optimized MRI scan pa-rameters in quantum filter techniques generate contrast in intracellular sodium MR images without using invasive contrast shift agents. Still, validity and clinical utility are in展开更多
目的:探讨超声双重造影参数在进展期胃癌肝转移(gastric cancer with liver metastasis,CGLM)治疗效果的可行性。方法:回顾性分析2021年4月—2022年4月于简阳市中医医院进行新辅助化疗(neoadjuvant chemotherapy,NAC)的71例CGLM患者的...目的:探讨超声双重造影参数在进展期胃癌肝转移(gastric cancer with liver metastasis,CGLM)治疗效果的可行性。方法:回顾性分析2021年4月—2022年4月于简阳市中医医院进行新辅助化疗(neoadjuvant chemotherapy,NAC)的71例CGLM患者的临床资料,按其治疗效果分为进展组(43例)、有效组(28例),对比两组治疗前后的超声参数指标。术后计算微血管密度(microvessel density,MVD),分析MVD与超声参数的相关性。结果:进展组与有效组BI、PI、EI治疗后下降且进展组高于有效组,RT、TTP均延长且进展组短于有效组;治疗3个周期后MVD与超声参数均呈正相关(P<0.05);超声双重造影检测各项指标的灵敏度依次为62.8%、46.5%、76.7%、48.8%、90.7%(P<0.05)。结论:超声双重造影参数能够有效评估CGLM患者治疗前后肿瘤变化情况,且能够对患者病情及新辅助化疗状况进行有效评估。展开更多
基金Supported by the National Natural Science Foundation of China(No.51875498)Hebei Provincial Natural Science Fund Key Project(No.E2018203339)Hebei Provincial Natural Science Foundation Steel Joint Research Fund(No.E2017203079)
文摘When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with bias.Because of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a reciprocating symmetrical dynamic flow test.Since the traditional differential pressure flowmeter is affected by viscosity and inertia of the fluid,it is only suitable for measuring steady flow.Therefore,a new type of double pressure differential dynamic flowmeter is designed to improve the traditional differential pressure flowmeter.The influence of fluid viscosity and inertia in the flow process are negated by subtracting the differential pressure in section expansion from the differential pressure in section contraction.The double differential pressure flowmeter is modeled and a flow meter prototype is designed.Then,the flow coefficients are identified and corrected by a practical test.Finally,the dynamic performance and steady-state precision of the flowmeter are verified by comparing with the test results of the no-load hydraulic cylinder.The double differential pressure dynamic flowmeter is proven to measure dynamic flow accurately,especially at higher dynamic frequencies.
文摘Background: In the last decade, sodium mag-netic resonance imaging was investigated for its potential as a functional cardiac imaging tool for ischemia. Later interest was developed in contrast enhancement for intracellular sodium. Little success was reported to suppress extracellular sodium resulting in the intracellular sodium MRI image acquisition using quantum filters or sodium transition states as contrast properties. Now its clinical application is ex-panding as a new challenge in brain and other cancer tumors. Contrast enhancement: We highlight the physical principles of sodium MRI in three different pulse sequences using filters (single quantum, multiple quantum, and triple quantum) meant for sodium contrast enhancement. The optimization of scan parameters, i.e. times of echo delay (TE), inversion recovery (TI) periods, and utility of Dysprosium (DyPPP) shift contrast agents, enhances contrast in sodium MRI images. Inversion recovery pulse sequence without any shift reagent measures the intracellular sodium concentration to evaluate ischemia, apoptosis and membrane integrity. Membrane integrity loss, apoptosis and malignancy are results of growth factor loss and poor epithelial capability related with MRI visible intracellular sodium concentration. Applications and limitations: The sodium MR imaging technical advances reduced scan time to distinguish intracellular and extracellular sodium signals in malignant tumors by use of quantum filter techniques to generate 3D sodium images without shift regents. We observed the association of malignancy with increased TSC, and reduced apoptosis and epithelial growth factor in breast cancer cells. The validity is still in question. Conclusion: Different modified sodium MRI pulse sequences are research tools of sodium contrast enhancement in brain, cardiac and tumor imaging. The optimized MRI scan pa-rameters in quantum filter techniques generate contrast in intracellular sodium MR images without using invasive contrast shift agents. Still, validity and clinical utility are in
文摘目的:探讨超声双重造影参数在进展期胃癌肝转移(gastric cancer with liver metastasis,CGLM)治疗效果的可行性。方法:回顾性分析2021年4月—2022年4月于简阳市中医医院进行新辅助化疗(neoadjuvant chemotherapy,NAC)的71例CGLM患者的临床资料,按其治疗效果分为进展组(43例)、有效组(28例),对比两组治疗前后的超声参数指标。术后计算微血管密度(microvessel density,MVD),分析MVD与超声参数的相关性。结果:进展组与有效组BI、PI、EI治疗后下降且进展组高于有效组,RT、TTP均延长且进展组短于有效组;治疗3个周期后MVD与超声参数均呈正相关(P<0.05);超声双重造影检测各项指标的灵敏度依次为62.8%、46.5%、76.7%、48.8%、90.7%(P<0.05)。结论:超声双重造影参数能够有效评估CGLM患者治疗前后肿瘤变化情况,且能够对患者病情及新辅助化疗状况进行有效评估。
