Two carboxylation processes were carried out to modify multi-walled carbon nanot ube bundles (m-MWNTs). The results showed that both of the m-MWNTs could be high ly dispersed in water with the concentration up to 25 a...Two carboxylation processes were carried out to modify multi-walled carbon nanot ube bundles (m-MWNTs). The results showed that both of the m-MWNTs could be high ly dispersed in water with the concentration up to 25 and 15mg/mL in ethanol wit hout obvious deposition or conglomeration over 6 months. FTIR, Raman, TGA and TE M characterizations of the m- MWNTs showed that hydroxyl and carboxyl groups hav e been attached with MWNTs, and that the nanotube structure was only damaged a l ittle after modification treatments in mixed acids over 24h. Above prepared nano tube suspensions in water were successfully used as a filler of thermoplastic PV A composite to enhance its electrical conductivity. The results showed that the addition of m-MWNTs greatly improved the conductivity and the threshold of mass fraction was about 5wt%. The results also proved that purification process was n ot needed because of high purity of the raw MWNTs prepared in our group.展开更多
The oxidation behaviour of a fourth-generation single-crystal superalloy without coating and with two types of MCrAlY coatings at 1140℃was studied.The results showed that both coatings greatly improved the oxidation ...The oxidation behaviour of a fourth-generation single-crystal superalloy without coating and with two types of MCrAlY coatings at 1140℃was studied.The results showed that both coatings greatly improved the oxidation resistance of the superalloy,and the addition of Hf further improved the oxidation resistance by pinning the oxide layer into the coating.Before and after oxidation,obvious Cr and Al interdiffusion was detected.Inward Cr diffusion induces the precipitation of a topologically close-packed phase,while the diffusion of Al affects the structure of theγ/γ’phase,the solubility of refractory elements,and the formation of an interdiffusion zone.展开更多
Background To compare the preventive effects of levetiracetam and valproate on late-onset post-traumatic seizures in patients with traumatic brain injury(TBI).Methods A total of 95 patients with TBI were recruited fro...Background To compare the preventive effects of levetiracetam and valproate on late-onset post-traumatic seizures in patients with traumatic brain injury(TBI).Methods A total of 95 patients with TBI were recruited from 2017 to 2020.They were randomized into three groups:levetiracetam(LEV)group(n=30)receiving LEV treatment(500 mg,bid,po);valproate group(n=32)receiving sodium valproate(500 mg/d,once daily,po);and control group(n=33)receiving no anti-seizure medication.LEV and valproate were given to corresponding groups within seven days after TBI,and the administration lasted for one month.The incidence of epilepsy and adverse events were evaluated at 7 days and 12 months post-TBI.Results The cumulative incidences of late post-traumatic seizures at the 12-month follow-up in the LEV,valproate,and control groups were 3.33%,12.50%and 15.63%,respectively.The cumulative incidence of late post-traumatic seizures in the LEV group was significantly lower than those in the valproate and control groups(P<0.05).The cumulative incidence of late post-traumatic seizure in the valproate group was not significantly different from that in the control group(P>0.05).Conclusions LEV can reduce the cumulative incidence of late post-traumatic seizures,whereas valproate can not.展开更多
Background:The mechanism of sudden unexpected death in epilepsy remains poorly understood.Seizure induced cardiac arrhythmia,central and obstructive apneas have been proposed as possible causes of death.Here we report...Background:The mechanism of sudden unexpected death in epilepsy remains poorly understood.Seizure induced cardiac arrhythmia,central and obstructive apneas have been proposed as possible causes of death.Here we report a unique case of seizure related sudden unexpected death in a patient whose airway was fully protected by intubation and mechanic ventilation in the absence of fatal cardiac arrhythmia.Case presentation:A 70-year-old woman was undergoing mechanical ventilation and videoelectroencephalography(EEG)monitoring following two convulsive seizures with ictal hypoventilation and hypoxemia.Several hours after intubation,she suffered another generalized tonic clonic seizure lasted for 3 min and developed postictal generalized EEG suppression in the presence of stable vital signs with SpO2>90%.EEG suppression persisted throughout the postictal phase.There was a significant fluctuation of systolic blood pressure between 50 and 180 mmHg with several bouts of hypotension<60 mmHg.She remained unresponsive after the convulsive seizure and died of diffuse cerebral edema 12 h later.Autopsy revealed no clear cause of death,except for possible hypoxic and ischemic injury leading to the diffuse cerebral edema.Conclusion:Given the reliable periictal airway protection,neither seizure induced central apnea nor obstructive apnea appeared to be the direct cause of death in this unique case.In the absence of fatal cardiac arrhythmia,diffuse cerebral edema secondary to seizure-induced autonomic dysfunction,hypotension and hypoxemia might be the cause of death,highlighting the etiological heterogeneity of sudden unexpected death in epilepsy.展开更多
Continuous electroencephalogram(cEEG)has become an indispensable technique in the management of critically ill patients for early detection and treatment of non-convulsive seizures(NCS)and non-convulsive status epilep...Continuous electroencephalogram(cEEG)has become an indispensable technique in the management of critically ill patients for early detection and treatment of non-convulsive seizures(NCS)and non-convulsive status epilepticus(NCSE).It has also brought about a renaissance in a wide range of rhythmic and periodic patterns with heterogeneous frequency and morphology.These patterns share the rhythmic and sharp appearances of electrographic seizures,but often lack the necessary frequency,spatiotemporal evolution and clinical accompaniments to meet the definitive criteria for ictal patterns.They may be associated with cerebral metabolic crisis and neuronal injury,therefore not clearly interictal either,but lie along an intervening spectrum referred to as ictal-interictal continuum(IIC).Generally speaking,rhythmic and periodic patterns are categorized as interictal patterns when occurring at a rate of<1Hz,and are categorized as NCS and NCSE when occurring at a rate of>2.5 Hz with spatiotemporal evolution.As such,IIC commonly includes the rhythmic and periodic patterns occurring at a rate of 1–2.5 Hz without spatiotemporal evolution and clinical correlates.Currently there are no evidence-based guidelines on when and if to treat patients with IIC patterns,and particularly how aggressively to treat,presenting a challenging electrophysiological and clinical conundrum.In practice,a diagnostic trial with preferably a non-sedative anti-seizure medication(ASM)can be considered with the end point being both clinical and electrographic improvement.When available and necessary,correlation of IIC with biomarkers of neuronal injury,such as neuronal specific enolase(NSE),neuroimaging,depth electrode recording,cerebral microdialysis and oxygen measurement,can be assessed for the consideration of ASM treatment.Here we review the recent advancements in their clinical significance,risk stratification and treatment algorithm.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.50172043)National High Technical Research and Development Programme of China(No.2002AA334020)National Key Basic Research and Development Programme of China(No.G20000264-06).
文摘Two carboxylation processes were carried out to modify multi-walled carbon nanot ube bundles (m-MWNTs). The results showed that both of the m-MWNTs could be high ly dispersed in water with the concentration up to 25 and 15mg/mL in ethanol wit hout obvious deposition or conglomeration over 6 months. FTIR, Raman, TGA and TE M characterizations of the m- MWNTs showed that hydroxyl and carboxyl groups hav e been attached with MWNTs, and that the nanotube structure was only damaged a l ittle after modification treatments in mixed acids over 24h. Above prepared nano tube suspensions in water were successfully used as a filler of thermoplastic PV A composite to enhance its electrical conductivity. The results showed that the addition of m-MWNTs greatly improved the conductivity and the threshold of mass fraction was about 5wt%. The results also proved that purification process was n ot needed because of high purity of the raw MWNTs prepared in our group.
基金supported by the National Science and Technology Major Project under Grant No.2017-VI-0002-0072the National Key Research and Development Program of China under Grant No.2017YFA0700704+2 种基金the National Natural Science Foundation of China(NSFC)under Grant Nos.51671188 and 51771190the Youth Innovation Promotion Association,Chinese Academy of Sciences and Innovation Academy for Light-duty Gas TurbineChinese Academy of Sciences under Grant No.CXYJJ20-MS-03。
文摘The oxidation behaviour of a fourth-generation single-crystal superalloy without coating and with two types of MCrAlY coatings at 1140℃was studied.The results showed that both coatings greatly improved the oxidation resistance of the superalloy,and the addition of Hf further improved the oxidation resistance by pinning the oxide layer into the coating.Before and after oxidation,obvious Cr and Al interdiffusion was detected.Inward Cr diffusion induces the precipitation of a topologically close-packed phase,while the diffusion of Al affects the structure of theγ/γ’phase,the solubility of refractory elements,and the formation of an interdiffusion zone.
基金funded by the Scientific Research Fund of China Association Against Epilepsy(No 2012002).
文摘Background To compare the preventive effects of levetiracetam and valproate on late-onset post-traumatic seizures in patients with traumatic brain injury(TBI).Methods A total of 95 patients with TBI were recruited from 2017 to 2020.They were randomized into three groups:levetiracetam(LEV)group(n=30)receiving LEV treatment(500 mg,bid,po);valproate group(n=32)receiving sodium valproate(500 mg/d,once daily,po);and control group(n=33)receiving no anti-seizure medication.LEV and valproate were given to corresponding groups within seven days after TBI,and the administration lasted for one month.The incidence of epilepsy and adverse events were evaluated at 7 days and 12 months post-TBI.Results The cumulative incidences of late post-traumatic seizures at the 12-month follow-up in the LEV,valproate,and control groups were 3.33%,12.50%and 15.63%,respectively.The cumulative incidence of late post-traumatic seizures in the LEV group was significantly lower than those in the valproate and control groups(P<0.05).The cumulative incidence of late post-traumatic seizure in the valproate group was not significantly different from that in the control group(P>0.05).Conclusions LEV can reduce the cumulative incidence of late post-traumatic seizures,whereas valproate can not.
文摘Background:The mechanism of sudden unexpected death in epilepsy remains poorly understood.Seizure induced cardiac arrhythmia,central and obstructive apneas have been proposed as possible causes of death.Here we report a unique case of seizure related sudden unexpected death in a patient whose airway was fully protected by intubation and mechanic ventilation in the absence of fatal cardiac arrhythmia.Case presentation:A 70-year-old woman was undergoing mechanical ventilation and videoelectroencephalography(EEG)monitoring following two convulsive seizures with ictal hypoventilation and hypoxemia.Several hours after intubation,she suffered another generalized tonic clonic seizure lasted for 3 min and developed postictal generalized EEG suppression in the presence of stable vital signs with SpO2>90%.EEG suppression persisted throughout the postictal phase.There was a significant fluctuation of systolic blood pressure between 50 and 180 mmHg with several bouts of hypotension<60 mmHg.She remained unresponsive after the convulsive seizure and died of diffuse cerebral edema 12 h later.Autopsy revealed no clear cause of death,except for possible hypoxic and ischemic injury leading to the diffuse cerebral edema.Conclusion:Given the reliable periictal airway protection,neither seizure induced central apnea nor obstructive apnea appeared to be the direct cause of death in this unique case.In the absence of fatal cardiac arrhythmia,diffuse cerebral edema secondary to seizure-induced autonomic dysfunction,hypotension and hypoxemia might be the cause of death,highlighting the etiological heterogeneity of sudden unexpected death in epilepsy.
基金the Capital Healthy Development ResearchFunding 2020–1-2013 and 2016–1-2011.
文摘Continuous electroencephalogram(cEEG)has become an indispensable technique in the management of critically ill patients for early detection and treatment of non-convulsive seizures(NCS)and non-convulsive status epilepticus(NCSE).It has also brought about a renaissance in a wide range of rhythmic and periodic patterns with heterogeneous frequency and morphology.These patterns share the rhythmic and sharp appearances of electrographic seizures,but often lack the necessary frequency,spatiotemporal evolution and clinical accompaniments to meet the definitive criteria for ictal patterns.They may be associated with cerebral metabolic crisis and neuronal injury,therefore not clearly interictal either,but lie along an intervening spectrum referred to as ictal-interictal continuum(IIC).Generally speaking,rhythmic and periodic patterns are categorized as interictal patterns when occurring at a rate of<1Hz,and are categorized as NCS and NCSE when occurring at a rate of>2.5 Hz with spatiotemporal evolution.As such,IIC commonly includes the rhythmic and periodic patterns occurring at a rate of 1–2.5 Hz without spatiotemporal evolution and clinical correlates.Currently there are no evidence-based guidelines on when and if to treat patients with IIC patterns,and particularly how aggressively to treat,presenting a challenging electrophysiological and clinical conundrum.In practice,a diagnostic trial with preferably a non-sedative anti-seizure medication(ASM)can be considered with the end point being both clinical and electrographic improvement.When available and necessary,correlation of IIC with biomarkers of neuronal injury,such as neuronal specific enolase(NSE),neuroimaging,depth electrode recording,cerebral microdialysis and oxygen measurement,can be assessed for the consideration of ASM treatment.Here we review the recent advancements in their clinical significance,risk stratification and treatment algorithm.
