Objective To study the effects of collateral circulation on the infarct types and cerebral perfusion state in patients with unilateral middle cerebral artery (MCA) severe stenosis or occlusion. Methods From January 2013 to June 2018,144 consecutivc patients with unilateral MCA severe stenosis or occlusion admitted to the Department of Neurology, Central War Zone General Hospital of PLA and diagnosed with 320-row Ct angiography were enrolled retrospectively. According to the collateral circulation,they were divided into good collateral circulation group (n =67) and reduced collateral circulation group (n -11). The infarct types were compared and analyzed between the two groups (perforator artery infarction [PAIJ ,pial infarct [PI] .large territory infarct [LTI] .and border-zone infarction [BZI] including corticle border-zone infarct (CBZI) .internal border-zone infarct (IBZI) and mixed BZI [MT.CBZI with IBZI]) and cerebral perfusion parameters (time to peak [11Y], cerebral blood volume [CBV],mean transit time [MTT] .cerebral blood flow [CBF] and ratio of affected side to normal side (affected side and healthy side,rCBV.rCBF, rTTP, and rMTT) between the two groups. SPSS22. 0 statistical software was used for data analysis and processing. Results (1) In 144 patients with unilateral MCA severe stenosis or occlusion,67 had good collateral circulation,77 had reduced collateral circulation. The occurrence of different types of infarction is as follows:PAI in 18 cases,PI in 11 cases,LTI in 18 cases,CBZI in 13 cases, IBZI in 32 cases, MT in 13 cases, MI in 17 cases, and non-infarction in 22 cases (including transient ischemic attack in 14 cases). In the good collateral circulation group, the proportion of patients with non-infarction was the highest (16 cases,23. 9%) and the proportion of LTI was the lowest (4 cases, 6. 0%) , while the proportion of IBZI was the highest (26 cases,33. 8%) and the proportion of PI was the lowest (4cases,5. 2%) in the reduced collateral circulation group. There was significant difference in the distribution of different types of infarction between the two groups (P <0. 01). (2) The results of comparison of cerebral perfusion parameters between the healthy side and the affected side in patients with different collateral circulation showed that the CBV (2. 48 ±0. 43 ml/100 g) of the affected side in patients with good collateral was increased significantly ,TTP (16.0 ±3.1 s) and MTT (4.4 ±0. 9 s) were prolonged significantly. The differences were statistically significant (all P <0.01). The TTP (18. 9 ±2.7 s) on the affected side in the reduced collateral group was significantly prolonged,MTT (3.8 ± 1.0s) was significantly shortened,and CBF (38 ± 13ml/100g • min) was significantly increased The differences were statistically significant (all P<0.01). (3) Comparison of cerebral perfusion parameters in patients with different collateral circulation,i€BV and rMTT (1.07 ±0l 15 and 1.06 ±0.15respectively) in the good collateral circulation group were higher than tlwse (Ol 98 ±0l 19 and 0.89 ±0l 20respectively) in the reduced collateral circulation group .while rTTP and rCBF (1. 12 ±0. 09 and 1. 03 ±0. 21 respectively) in the good collateral circulation group were lower than those (1.20 ±0.09 and 1. 12 ±0.29 respectively) in the reduced collateral circulation group. The differences were statistically significant (all P < 0. 05) . Conclusion Good collateral circulation can compensate for cerebral perfusion in patients with unilateral MCA severe stenosis or occlusion to prevent the occurrence of cerebral infarction or reduce the infarct size.

Objective To measure the present situation of medical students' learning adaptability and find the influencing factors in order to revise Learning Adaptability Scale for medical students.Methods A stratified sampling method was used to collect 1 180 medical students from Harbin Medical University.Using the internal consistency reliability test,the reliability of the revised student learning adaptability scale was verified.Five common factors were extracted by the exploratory factor analysis of the principal analysis method,and Logistic regression was used to analyze the influencing factors of medical student learning adaptability.Results The revised Student Learning Adaptability Scale (Cronbach's Alpha=0.914) consists of 27 measurement items.It includes five dimensions,namely self-directed learning,information utilization,environment choice,stresses response and goal orientation.The results showed that the adaptability of medical students was moderate (3.28 ± 0.52),and the influencing factors included job position (OR =1.496,95％ CI=1.114-2.009),academic achievement (OR =1.638,95 ％ CI=1.386-1.936),satisfaction with learning (OR=2.160,95％CI=1.745-2.673),professional satisfaction (OR=1.369,95％CI=1.092-1.718),professional interest (OR =1.426,95％ CI=1.186-1.715) and employment prospects (OR =1.526,95％ CI=1.251-1.862).Conclusion The reliability and validity of the Student Learning Adaptability Scale is appropriate.Medical students' learning adaptability is influenced by many factors.

Diabetes can significantly increase the risk of post-stroke cognitive impairment (PSCI). Previous studies have shown that diabetes can be involved in the occurrence of cognitive impairment by insulin resistance, blood-brain barrier damage, low level inflammation, β-amyloid deposition and tau phosphorylation, aggravation of ischemic brain injury and oxidative stress. In recent years, the role of diabetes in the pathophysiology of PSCI is attracting increasing attention. This article reviews the correlation between diabetes mellitus and PSCI and the possible pathophysiological mechanisms, hoping to provide reference for prevention and treatment strategies of PSCI in diabetics.

Innovative self-efficacy is the degree of self-confidence in the individual's ability to per-form innovative activities. Although the theory of innovation self-efficacy is shorter, but as an important indicator of innovation ability measurement, it has been accepted by scholars in various countries, and innovative self-efficacy provides a new perspective for the cultivation of innovative talents. The research of innovation self-efficacy is still the initial stage. Chinese and foreign scholars have made some progress in measuring tools, antecedents, aftereffect and development, but there are still obvious differences and defi-ciencies,and the research results are not abundant.The future research will focus on the measurement tools, influencing factors and research direction of three aspects of systematic research to improve the theory of innovation self-efficacy.

Objective:To investigate the metabolic disorder of gut microbiota and short-chain fatty acids (SCFAs) in patients with hypertensive intracerebral hemorrhage and their correlations with the poor outcomes.Methods:Thirty-eight patients with hypertensive intracerebral hemorrhage within 7 d of onset and 32 healthy controls were enrolled prospectively. Fecal samples were collected for 16S rRNA sequencing and SCFAs levels detection. The outcome was evaluated by the modified Rankin Scale at 90 d after the onset, and >2 points were defined as a poor outcome. Multivariate logistic regression model was used to determine the correlations between the gut microbiota and the fecal SCFAs levels and outcomes. Results:The gut microbiota of patients with hypertensive intracerebral hemorrhage was significantly different from that of healthy control group. It is manifested as a decrease in α diversity, a difference in β diversity, an increase in the abundance of potential undesirable bacteria, a decrease in the abundance of common SCFA-producing bacteria and a decrease in the fecal SCFAs levels. In patients with hypertensive intracerebral hemorrhage, compared with the good outcome group, the α diversity of the gut microbiota, the abundance of SCFA-producing bacteria such as Lacetospirillum and Bacteroides, and the total SCFAs, acetic acid and propionic acid levels decreased in the poor outcome group. Multivariate logistic regression analysis showed that after adjusting for potential confounding factors, the decrease of fecal SCFAs levels after log2 conversion was significantly and independently correlated with the poor outcomes. Conclusion:Patients with hypertensive intracerebral hemorrhage have gut microbiota and SCFAs metabolic disorder, the latter is significantly correlated with the poor outcomes. Gut microbiota and SCFAs may become an outcome marker and treatment target for patients with hypertensive intracerebral hemorrhage