Objective To explore the clinical features and risk factors of post-concussion syndrome (PCS) in patients after mild traumatic brain injury (mTBI).Methods Two hundred and seventy-six patients with mTBI,admitted to our hospital from December 2016 to June 2018,were chosen in our study;114 patients (41.30％) developed PCS.The epidemiological data,causes and sites of brain injury,clinical symptoms,and duration and time of PCS occurrence were investigated.Multivariate Logistic regression was used to analyze the risk factors of PCS in patients with mTBI.Results The most common syndromes of PCS were headache (89.13％),amnesia (63.77％),dizziness (63.04％) and nausea (57.61％).The incidence rate of PCS was 51.75％ in the first month of injury and decreased with time.Multifactor Logistic regression analysis showed that student (P=0.041,OR=0.36,95％ CI:0.14-0.95),electric bicycle accidents (P=0.043,OR=0.54,95％CI:0.30-0.98),and occipital injury (P=0.022,OR=0.28,95％CI:0.09-0.83) were independent risk factors of PCS of mTBI patients.Conclusion Patients with mTBI,especially those who are students,victims of electric bicycle accidents and victims of occipital injury,should be highly alert to the occurrence of PCS,and need reasonable rest,symptomatic treatments and memory training or other rehabilitation treatments within one month of injury,in order to prevent the development of PCS.

【Objective】 To compare the supply data of red blood cells(RBCs) from 18 blood centers in China before and after the outbreak of COVID-19 during 2018 to 2021. 【Methods】 Eight indicators related to RBCs supply from 18 blood centers in China during 2018-2021 were collected retrospectively, including the storage of total amount of qualified RBCs (referred to as the total amount of storage), the distribution of total amount of RBCs (referred to as the total amount of distribution), the distribution amount of RBCs per 1 000 population (referred to as the amount of distribution per 1 000 population), the distribution amount of RBCs from 400 mL original blood per 1 000 population [referred to as the amount of distribution per 1 000 population (400 mL)], the average daily distribution amount of RBCs (referred to as the average daily distribution amount), the average daily storage amount of RBCs (referred to as the average daily storage amount), the average storage days of RBCs when distribute (referred to as the RBC storage days), and the expired amount of RBCs (referred to as the expired amount). Based on the outbreak time of COVID-19, the data of 2018 and 2019 were the pre-pandemic group, and the data of 2020 and 2021 were the post-pandemic group. 【Results】 Data on RBCs supply in 18 blood centers from 2018 to 2021(comparison of the pre-pandemic group and the post-pandemic group): the amount of distribution per 1 000 population (median 14.68 U>13.92 U) decreased, the amount of distribution per 1 000 population (400 mL) (median 10.16 U>9.21 U) decreased, and the difference was statistically significant (P<0.05); data comparison between 2019 and 2020:the total amount of distribution (median 117 770.38 U>99 084.08 U) decreased, the amount of distribution per 1 000 population (median 15.04 U>12.19 U) decreased, the amount of distribution per 1000 population (400 mL) (median 10.11 U>8.94 U), the average daily distribution amount(322.66 U>270.73 U) decreased and RBC storage days (median 10.50 d<11.45 d) increased, the difference has statistical significance (P<0.05); data comparison between 2020 and 2021:the total amount of storage (median 101 920.25 U<120 328.63 U), the total amount of distribution (median 99 084.08 U<118 428.62 U), the amount of distribution per 1 000 population (median 12.19 U<15.00 U), the amount of distribution per 1 000 population (400 mL) (median 8.94 U<9.46 U), the average daily distribution amount (270.73 U>324.46 U), the average daily inventory (median 3 222.00 U<4 328.00 U) increased, the expired amount (median 1.50 U>0.00 U) decreased, the difference has statistical significance (P<0.05). The results of ANOVA showed that there were significant differences on the data related to RBCs supply (except expired amount) in different blood centers (P<0.05). The ratio of average daily stock to average daily distribution in the post-outbreak group (median 12.36 d) was higher than that in the pre-outbreak group (median 10.92 d), the difference has statistical significance (P<0.05), with significant difference among different blood centers (P <0.05). 【Conclusion】 The COVID-19 pandemic has a significant impact on RBCs supply in different blood centers. In the second year of the pandemic, the supply capability had recovered to some extent, and there were differences in RBCs supply in different blood centers.