Objective To investigate the abnormal changes characteristics of the degree centrality(DC)of the brain functional network in patients with benign paroxysmal positional vertigo(BPPV)in the classical frequency band(0.010-0.080 Hz),the slow-4 frequency band(0.027-0.073 Hz),and the slow-5 frequency band(0.010-0.027 Hz).Methods Twenty patients with BPPV(BPPV group)and 14 healthy controls(HC)(HC group)were selected.Resting-state functional magnetic resonance imaging(rs-fMRI)scans were performed,and the clinical data were analyzed.The DC method was used to analyze the changes of centrality of resting state network in patients with BPPV.Results Compared with the HC group,the BPPV group showed an increase in DC in the left caudate nucleus in the classical frequency band(P＜0.05),and a decrease in DC in the right auxiliary motor region in the classical frequency band(P＜0.05);within the slow-4 frequency band,no significant differences were observed in brain regions(P＞0.05);within the slow-5 frequency band,the BPPV group showed an increase in DC in the left thalamus(P＜0.05),while the left anterior cingulate and paracingulate gyrus showed a decrease in DC(P＜0.05).Conclusion Patients with BPPV have spontaneous activity disorders in multiple brain regions at resting states,and these changes show frequency band specificity.

Objective To investigate the abnormal changes characteristics of the degree centrality(DC)of the brain functional network in patients with benign paroxysmal positional vertigo(BPPV)in the classical frequency band(0.010-0.080 Hz),the slow-4 frequency band(0.027-0.073 Hz),and the slow-5 frequency band(0.010-0.027 Hz).Methods Twenty patients with BPPV(BPPV group)and 14 healthy controls(HC)(HC group)were selected.Resting-state functional magnetic resonance imaging(rs-fMRI)scans were performed,and the clinical data were analyzed.The DC method was used to analyze the changes of centrality of resting state network in patients with BPPV.Results Compared with the HC group,the BPPV group showed an increase in DC in the left caudate nucleus in the classical frequency band(P＜0.05),and a decrease in DC in the right auxiliary motor region in the classical frequency band(P＜0.05);within the slow-4 frequency band,no significant differences were observed in brain regions(P＞0.05);within the slow-5 frequency band,the BPPV group showed an increase in DC in the left thalamus(P＜0.05),while the left anterior cingulate and paracingulate gyrus showed a decrease in DC(P＜0.05).Conclusion Patients with BPPV have spontaneous activity disorders in multiple brain regions at resting states,and these changes show frequency band specificity.

OBJECTIVE To optimize the extraction process of polysaccharides from Dendrobium officinale， and preliminarily study its effect on acute lung injury （ALI） in mice. METHODS Using D. officinale as raw material， the polysaccharides were extracted from D. officinale by ultrasonic-assisted hot water immersion. Using the extraction rate of D. officinale polysaccharides as response value， the single-factor experiments and Box-Behnken response surface method were used to optimize the ratio of material to liquid， extraction time and extraction temperature. ALI mice were induced by lipopolysaccharide. Using prednisone acetate （5 mg/kg） as the positive control， the effects on the mass ratio of wet and dry lung and pathological changes of lung tissue （HE staining and Masson staining） of low-dose， medium-dose and high-dose D. officinale polysaccharides （50，100，200 mg/kg） were investigated. RESULTS The optimal extraction technology of D. officinale polysaccharides was as follows： the ratio of material to liquid was 1∶25 （g/mL）， the extracting time was 1 h， and the extracting temperature was 58 ℃ . Under these conditions， the average extraction rate of D. officinale polysaccharides was 37.75% （RSD＝1.12%，n＝3）， the relative error of which with predicted value （38.63%） was 2.28%. Compared with the model group， the ratios of wet and dry lung in the positive control group and D. officinale polysaccharides groups were all decreased significantly （P＜0.05 or P＜0.01）， and the pathological changes in lung tissue （severe destruction of alveolar structure， significant widening of alveolar septa， extensive infiltration of inflammatory cells and proliferation of fibroblasts） were alleviated to varying degrees. CONCLUSIONS The optimal extraction process of D. officinale polysaccharides is feasible； the obtained polysaccharide extract has a certain improvement effect on ALI in mice.