Horizontal gas-liquid two-phase flows widely exist in chemical engineering,oil/gas production and other important industrial processes.Slug flow pattern is the main form of horizontal gas-liquid flows and characterize...Horizontal gas-liquid two-phase flows widely exist in chemical engineering,oil/gas production and other important industrial processes.Slug flow pattern is the main form of horizontal gas-liquid flows and characterized by intermittent motion of film region and slug region.This work aims to develop the ultrasonic Doppler method to realize the simultaneous measurement of the velocity profile and liquid film thickness of slug flow.A single-frequency single-channel transducer is adopted in the design of the field-programmable gate array based ultrasonic Doppler system.A multiple echo repetition technology is used to improve the temporal-spatial resolution for the velocity profile.An experiment of horizontal gas-liquid two-phase flow is implemented in an acrylic pipe with an inner diameter of 20 mm.Considering the aerated characteristics of the liquid slug,slug flow is divided into low-aerated slug flow,high-aerated slug flow and pseudo slug flow.The temporal-spatial velocity distributions of the three kinds of slug flows are reconstructed by using the ultrasonic velocity profile measurement.The evolution characteristics of the average velocity profile in slug flows are investigated.A novel method is proposed to derive the liquid film thickness based on the instantaneous velocity profile.The liquid film thickness can be effectively measured by detecting the position and the size of the bubbles nearly below the elongated gas bubble.Compared with the time of flight method,the film thickness measured by the Doppler system shows a higher accuracy as a bubble layer occurs in the film region.The effect of the gas distribution on the film thickness is uncovered in three kinds of slug flows.展开更多
Hepatocellular carcinoma （HCC） is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 16 （PPM1D） was highly expressed in the majority of HCC cases （approxi...Hepatocellular carcinoma （HCC） is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 16 （PPM1D） was highly expressed in the majority of HCC cases （approximately 59%） and significantly associated with high serum a-fetoprotein （AFP） level （P = 0.044）. Kaplan- Meier and Cox regression data indicated that PPM1D overexpression was an independent predictor of HCC- specific overall survival （HR, 2.799; 95% CI, 1.346-5.818, P = 0.006）. Overexpressing PPM1D promoted cell viability and invasion, whereas RNA interference-mediated knockdown of PPM1D inhibited proliferation, invasion, and migration of cultured HCC cells. In addition, PPM1D suppression by small interfering RNA decreased the tumorigenicity of HCC cells in vivo. Overall, results suggest that PPM1D is a potential prognostic marker and therapeutic target for HCC.展开更多
基金supported by the National Natural Science Foundation of China(41974139,42274148,42074142)。
文摘Horizontal gas-liquid two-phase flows widely exist in chemical engineering,oil/gas production and other important industrial processes.Slug flow pattern is the main form of horizontal gas-liquid flows and characterized by intermittent motion of film region and slug region.This work aims to develop the ultrasonic Doppler method to realize the simultaneous measurement of the velocity profile and liquid film thickness of slug flow.A single-frequency single-channel transducer is adopted in the design of the field-programmable gate array based ultrasonic Doppler system.A multiple echo repetition technology is used to improve the temporal-spatial resolution for the velocity profile.An experiment of horizontal gas-liquid two-phase flow is implemented in an acrylic pipe with an inner diameter of 20 mm.Considering the aerated characteristics of the liquid slug,slug flow is divided into low-aerated slug flow,high-aerated slug flow and pseudo slug flow.The temporal-spatial velocity distributions of the three kinds of slug flows are reconstructed by using the ultrasonic velocity profile measurement.The evolution characteristics of the average velocity profile in slug flows are investigated.A novel method is proposed to derive the liquid film thickness based on the instantaneous velocity profile.The liquid film thickness can be effectively measured by detecting the position and the size of the bubbles nearly below the elongated gas bubble.Compared with the time of flight method,the film thickness measured by the Doppler system shows a higher accuracy as a bubble layer occurs in the film region.The effect of the gas distribution on the film thickness is uncovered in three kinds of slug flows.
基金financially supported by the Scientific Research Start-up Funds of Hexi University(KYQD2022004)the 13th Innovation Program Science and Technology for college students of Hexi University(138)。
基金This study was supported by grants from the National Natural Science Foundation of China （Nos. 81000880 and 81370057 to Zhi Xu）, the Key Project supported by Medical Science and Technology Development Foundation, Nanjing Department of Health （JQX12007 to Zhi Xu）, the clinical special project for Natural Science Foundation of Jiangsu Province （BL2012016 to Jinfei Chen）, and the Nanjing 12th Five-Year Key Scientific Project of Medicine to Jinfei Chen.
文摘Hepatocellular carcinoma （HCC） is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 16 （PPM1D） was highly expressed in the majority of HCC cases （approximately 59%） and significantly associated with high serum a-fetoprotein （AFP） level （P = 0.044）. Kaplan- Meier and Cox regression data indicated that PPM1D overexpression was an independent predictor of HCC- specific overall survival （HR, 2.799; 95% CI, 1.346-5.818, P = 0.006）. Overexpressing PPM1D promoted cell viability and invasion, whereas RNA interference-mediated knockdown of PPM1D inhibited proliferation, invasion, and migration of cultured HCC cells. In addition, PPM1D suppression by small interfering RNA decreased the tumorigenicity of HCC cells in vivo. Overall, results suggest that PPM1D is a potential prognostic marker and therapeutic target for HCC.
