Background: Blocking the Rho A/ROCK Ⅱ/MLC 2(Ras homolog gene family member A/Rho kinase Ⅱ/myosin light chain 2) signaling pathway can initiate neuroprotective mechanisms against neurological diseases such as stroke,...Background: Blocking the Rho A/ROCK Ⅱ/MLC 2(Ras homolog gene family member A/Rho kinase Ⅱ/myosin light chain 2) signaling pathway can initiate neuroprotective mechanisms against neurological diseases such as stroke, cerebral ischemia, and subarachnoid hemorrhage. Nevertheless, it is not clear whether and how disrupting the Rho A/ROCK Ⅱ/MLC 2 signaling pathway changes the pathogenic processes of the blood–brain barrier(BBB) after intracerebral hemorrhage(ICH). The present investigation included the injection of rat caudal vein blood into the basal ganglia area to replicate the pathophysiological conditions caused by ICH. Methods: Scalp acupuncture(SA) therapy was performed on rats with ICH at the acupuncture point “Baihui”-penetrating “Qubin,” and the ROCK selective inhibitor fasudil was used as a positive control to evaluate the inhibitory effect of acupuncture on the Rho A/ROCK Ⅱ/MLC 2 signaling pathway. Post-assessments included neurological deficits, brain edema, Evans blue extravasation, Western blot, quantitative polymerase chain reaction, and transmission electron microscope imaging. Results: We found that ROCK Ⅱ acts as a promoter of the Rho A/ROCK Ⅱ/MLC 2 signaling pathway, and its expression increased at 6 h after ICH, peaked at 3 days, and then decreased at 7 days after ICH, but was still higher than the preintervention level. According to some experimental results, although 3 days is the peak, 7 days is the best time point for acupuncture treatment. Starting from 6 h after ICH, the neurovascular structure and endothelial cell morphology around the hematoma began to change. Based on the changes in the promoter ROCK Ⅱ, a 7-day time point was selected as the breakthrough point for treating ICH model rats in the main experiment. The results of this experiment showed that both SA at “Baihui”-penetrating “Qubin” and treatment with fasudil could improve the expression of endothelial-related proteins by inhibiting the Rho A/ROCK Ⅱ/MLC 2 signaling pathway and reduce neurological dysfunction, brain edema, and BBB permeability in rats. Conclusion: This study found that these experimental data indicated that SA at “Baihui”-penetrating “Qubin” could preserve BBB integrity and neurological function recovery after ICH by inhibiting Rho A/ROCK Ⅱ/MLC 2 signaling pathway activation and by regulating endothelial cell–related proteins.展开更多
Solid-state circuit breakers(SSCBs)are critical components in the protection of medium-voltage DC distribution networks to facilitate arc-free,fast and reliable isolation of DC faults.However,limited by the capacity o...Solid-state circuit breakers(SSCBs)are critical components in the protection of medium-voltage DC distribution networks to facilitate arc-free,fast and reliable isolation of DC faults.However,limited by the capacity of a single semiconductor device,using semi-conductor-based SSCBs at high voltage is challenging.This study presents the details of a 1.5 kV,63 A medi-um-voltage SSCB,composed primarily of a solid-state switch based on three cascaded normally-on silicon car-bide(SiC)junction field-effect transistors(JFETs)and a low-cost programmable gate drive circuit.Dynamic and static voltage sharing among the cascaded SiC JFETs of the SSCB during fault isolation is realized using the pro-posed gate drive circuit.The selection conditions for the key parameters of the SSCB gate driver are also analyzed.Additionally,an improved pulse-width modulation cur-rent-limiting protection solution is proposed to identify the permanent overcurrent and transient inrush current associated with capacitive load startup in a DC distribu-tion network.Using the developed SSCB prototype and the fault test system,experimental results are obtained to validate the fault response performance of the SSCB.Index Terms—Solid-state circuit breaker,DC distribu-tion network,SiC JFET,voltage balancing,inrush current.展开更多
Coronavirus disease 2019(COVID-19)has spread throughout China.However,information about COVID-19 in cities and regions outside Wuhan is limited and the indicators that predict the length of hospital stay for patients ...Coronavirus disease 2019(COVID-19)has spread throughout China.However,information about COVID-19 in cities and regions outside Wuhan is limited and the indicators that predict the length of hospital stay for patients with COVID-19 are unclear.Therefore,we collected clinical data from 47 patients with COVID-19 in Quanzhou City.The median age was 38 years[interquartile range(IQR):31–50 years],and 24(51%)were male.There were 8 mild,36 moderate,and 3 severe/critical cases.The median interval from exposure to disease onset was 13 days(IQR:8–18 days).The incidence of severe/critical cases was 33%(3/10)in patients with hypertension.Common symptoms included fever(83%),cough(77%),fatigue(40%),a sore,dry throat(28%),and diarrhea(21%).One patient(2%)developed respiratory distress syndrome on day 13 of inpatient treatment.Six patients had leukopenia,17 had elevated C-reactive protein(CRP),and 8 had lymphocytopenia and elevated lactate dehydrogenase(LDH).The median length of hospitalization was 22 days(IQR:16-30 days).Dynamic monitoring of LDH,CRP,and neutrophil-lymphocyte ratio predicted whether length of hospitalization would exceed 21 days.Most patients presented with mild and moderate disease.Patients with hypertension were more likely to become severe or critical.Dynamic monitoring of LDH,CRP,and neutrophil-lymphocyte ratio levels can help predict delayed discharge from the hospital.展开更多
基金supported by the National Natural Science Foundation of China(numbers:81774416 and 81473764)。
文摘Background: Blocking the Rho A/ROCK Ⅱ/MLC 2(Ras homolog gene family member A/Rho kinase Ⅱ/myosin light chain 2) signaling pathway can initiate neuroprotective mechanisms against neurological diseases such as stroke, cerebral ischemia, and subarachnoid hemorrhage. Nevertheless, it is not clear whether and how disrupting the Rho A/ROCK Ⅱ/MLC 2 signaling pathway changes the pathogenic processes of the blood–brain barrier(BBB) after intracerebral hemorrhage(ICH). The present investigation included the injection of rat caudal vein blood into the basal ganglia area to replicate the pathophysiological conditions caused by ICH. Methods: Scalp acupuncture(SA) therapy was performed on rats with ICH at the acupuncture point “Baihui”-penetrating “Qubin,” and the ROCK selective inhibitor fasudil was used as a positive control to evaluate the inhibitory effect of acupuncture on the Rho A/ROCK Ⅱ/MLC 2 signaling pathway. Post-assessments included neurological deficits, brain edema, Evans blue extravasation, Western blot, quantitative polymerase chain reaction, and transmission electron microscope imaging. Results: We found that ROCK Ⅱ acts as a promoter of the Rho A/ROCK Ⅱ/MLC 2 signaling pathway, and its expression increased at 6 h after ICH, peaked at 3 days, and then decreased at 7 days after ICH, but was still higher than the preintervention level. According to some experimental results, although 3 days is the peak, 7 days is the best time point for acupuncture treatment. Starting from 6 h after ICH, the neurovascular structure and endothelial cell morphology around the hematoma began to change. Based on the changes in the promoter ROCK Ⅱ, a 7-day time point was selected as the breakthrough point for treating ICH model rats in the main experiment. The results of this experiment showed that both SA at “Baihui”-penetrating “Qubin” and treatment with fasudil could improve the expression of endothelial-related proteins by inhibiting the Rho A/ROCK Ⅱ/MLC 2 signaling pathway and reduce neurological dysfunction, brain edema, and BBB permeability in rats. Conclusion: This study found that these experimental data indicated that SA at “Baihui”-penetrating “Qubin” could preserve BBB integrity and neurological function recovery after ICH by inhibiting Rho A/ROCK Ⅱ/MLC 2 signaling pathway activation and by regulating endothelial cell–related proteins.
基金supported in part by Hunan Provincial Natural Science Foundation of China(No.2021JJ40172).
文摘Solid-state circuit breakers(SSCBs)are critical components in the protection of medium-voltage DC distribution networks to facilitate arc-free,fast and reliable isolation of DC faults.However,limited by the capacity of a single semiconductor device,using semi-conductor-based SSCBs at high voltage is challenging.This study presents the details of a 1.5 kV,63 A medi-um-voltage SSCB,composed primarily of a solid-state switch based on three cascaded normally-on silicon car-bide(SiC)junction field-effect transistors(JFETs)and a low-cost programmable gate drive circuit.Dynamic and static voltage sharing among the cascaded SiC JFETs of the SSCB during fault isolation is realized using the pro-posed gate drive circuit.The selection conditions for the key parameters of the SSCB gate driver are also analyzed.Additionally,an improved pulse-width modulation cur-rent-limiting protection solution is proposed to identify the permanent overcurrent and transient inrush current associated with capacitive load startup in a DC distribu-tion network.Using the developed SSCB prototype and the fault test system,experimental results are obtained to validate the fault response performance of the SSCB.Index Terms—Solid-state circuit breaker,DC distribu-tion network,SiC JFET,voltage balancing,inrush current.
基金the Natural Science Foundation of China(81400625)Natural Science Foundation of Fujian Province(2019J01593,2017J01228)+2 种基金High-Level Talent Innovation Project of Quanzhou(2018C067R)Science and Technology Innovation Project of Fujian Province(2019Y9048)Pilot Project of Fujian Provincial Department of Science&Technology(2020Y0005)。
文摘Coronavirus disease 2019(COVID-19)has spread throughout China.However,information about COVID-19 in cities and regions outside Wuhan is limited and the indicators that predict the length of hospital stay for patients with COVID-19 are unclear.Therefore,we collected clinical data from 47 patients with COVID-19 in Quanzhou City.The median age was 38 years[interquartile range(IQR):31–50 years],and 24(51%)were male.There were 8 mild,36 moderate,and 3 severe/critical cases.The median interval from exposure to disease onset was 13 days(IQR:8–18 days).The incidence of severe/critical cases was 33%(3/10)in patients with hypertension.Common symptoms included fever(83%),cough(77%),fatigue(40%),a sore,dry throat(28%),and diarrhea(21%).One patient(2%)developed respiratory distress syndrome on day 13 of inpatient treatment.Six patients had leukopenia,17 had elevated C-reactive protein(CRP),and 8 had lymphocytopenia and elevated lactate dehydrogenase(LDH).The median length of hospitalization was 22 days(IQR:16-30 days).Dynamic monitoring of LDH,CRP,and neutrophil-lymphocyte ratio predicted whether length of hospitalization would exceed 21 days.Most patients presented with mild and moderate disease.Patients with hypertension were more likely to become severe or critical.Dynamic monitoring of LDH,CRP,and neutrophil-lymphocyte ratio levels can help predict delayed discharge from the hospital.
