Objective To study the effects of intramedullary pressure on the fluid flow behavior in bones.Methods Multi-scale models of macro bone tissue and macro-meso osteon groups were established using the COMSOL Multiphysics software.Considering the interrelationship of different pore scales,such as the bone marrow cavity,Haversia canal,and bone lacunar-canaliculus,the pore pressure and flow rate of hollow bone tissues and bone tissues with intramedullary pressure were compared,and the effects of the amplitude and frequency of intramedullary pressure on the pressure and flow velocity of the liquid in the bone were analyzed.Results When intramedullary pressure was considered,the pore pressure in bone tissues with intramedullary pressure was 6.4 kPa higher than that in hollow bone tissues.The flow pressure increased significantly with an increase in the intramedullary pressure amplitude,but the flow velocity remained unchanged.The frequency of intramedullary pressure had little effect on pore pressure and flow velocity.Conclusions The multi-scale pore model established in this study can accurately analyze bone fluid flow behavior.These results are of great significance for an in-depth understanding of force conduction in the bone.

Neonatal seizure is one of the most common manifestations of newborns, which could lead to severe neurological sequelae, such as epilepsy, cerebral palsy, developmental delay, mental retardation and even death.The causes of neonatal seizures are the key factors contributing to prognosis.In addition, individual factors, types of seizure and EEG could affect the prognosis in varying degrees.Therefore, for patients with poor prognosis, early diagnosis and treatment could effectively improve the prognosis and reduce the mortality.

Objective: To explore the relationship between features of neonatal seizure and recent outcomes of patients with unexplained neonatal seizure, which may provide evidence for early assessment of prognosis. Methods: Forty-seven cases of unexplained neonatal seizure admitted to the Department of Neonatology in Shengjing Hospital of China Medical University from January 2014 to June 2018, were followed-up at the age of more than 6 months.According to the recent outcomes(recurrent seizures during non-neonatal period and levels of development when they were followed-up), the patients were divided into good recent outcomes group(34 cases)and poor recent outcomes group(13 cases). The general information, characteristics of seizure and EEG changes during neonatal period were analyzed retrospectively. Results: There was no significant difference in gender, gestational age, birth weight, onset of first seizure, type of seizure, duration of seizure, and interval of seizures between two groups(P>0.05). There were 11 cases in poor recent outcomes group and 30 cases in good recent outcomes group that finished EEG.Compared with patients with good recent outcomes, patients with poor recent outcomes had significantly more abnormal EEG, paroxysmal abnormal changes and paroxysmal abnormal changes with abnormal background activity(90.9% vs.43.3%, 63.6% vs.10.0%, 36.4% vs.6.7%), with statistically significant difference(P<0.05). Thirty-nine cases with recurrent seizures during non-neonatal period had significantly higher rate of dysplasia than the 34 cases that without recurrent seizures(50.0% vs.12.8%), with statistically significant difference(P<0.05). Conclusion The recent outcomes of unexplained neonatal seizure may be related the EEG changes, but not gender, gestational age, birth weight, features of seizure.The neonates with unexplained neonatal seizure whose EEG manifest as paroxysmal abnormalities, were more likely to get poor recent outcomes, such as recurrent seizures and(or)dysplasia during non-neonatal period.

Amplitude-integrated electroencephalogram(aEEG)is a new method for bedside monitoring of cerebral function which is gradually used in clinical routine.Although the grading criteria has not been unified, some studies suggest that aEEG recorded during the very early period after birth can not only indicate the maturation of brain development, but also provide values of clinical application on the early identification, determination of the severity and long-term prognosis assessment of brain injury(e.g.white matter injury, intracranial hemorrhage, etc.)in premature infants.