Optimizing yield and chemical compositions of dimethylsulfoxide-extracted birchwood xylan

Dimethylsulfoxide(DMSO)extraction is commonly used to study the chemical structures of orig-inal xylan in the plant cell wall,since the DMSO can preserve the original structure of the xylan as much as possible during the extracting process.In addition,the DMSO-extracted xylans have unique properties allowing their potential applications in emulsifying or filming materials.How-ever,the yield of DMSO-extracted xylan is always low and the effects of different DMSO extraction conditions on the chemical compositions of xylan have not been fully studied,which greatly hin-ders its researches and applications.In this study,we have found that extensive delignification before DMSO extraction results in destruction of lignin-carbohydrate complex(LCC),leading to xylan yield and xylose unit content increased by up to 220%and 20%,respectively.Tert-butanol washing of the holocellulose can further increase the DMSO extracted xylan yield by∼10%.The yield of xylan extracted by the DMSO at 80°C for 7 h was obviously higher than that at room temperature for 3 d by 30%-40%.Thermal analysis showed that the xylans extracted at differ-ent conditions had thermal stability without obvious differences.The results indicate that the DMSO-extracted xylan with a high yield,a high purity and a high degree of acetylation can be ex-tracted at a high delignification level,a high reaction temperature and a short reaction time.This study is of great significance for studying xylan structure-property relationships and promoting the applications of DMSO-extracted xylan.

Voxel-based magnetic resonance imaging investigation of poor and preserved clinical insight in people with schizophrenia

AIM To define regional grey-matter abnormalities in schizophrenia patients with poor insight(Insight-),relative to patients with preserved clinical insight(Insight+),and healthy controls.METHODS Forty stable schizophrenia outpatients(20 Insight-and 20 Insight+) and 20 healthy controls underwent whole brain magnetic resonance imaging(MRI).Insight in all patients was assessed using the Birchwood Insight Scale(BIS;a self-report measure).The two patient groups were preselected to match on most clinical and demographic parameters but,by design,they had markedly distinct BIS scores.Voxel-based morphometry employed in SPM8 was used to examine group differences in grey matter volumes across the whole brain.RESULTS The three participant groups were comparable in age [F(2,57) = 0.34,P = 0.71] and the patient groups did not differ in age at illness onset [t(38) = 0.87,P = 0.39].Insight-and Insight+ patient groups also did not differ in symptoms on the Positive and Negative Syndromes scale(PANSS):Positive symptoms [t(38) = 0.58,P = 0.57],negative symptoms [t(38) = 0.61,P = 0.55],general psychopathology [t(38) = 1.30,P = 0.20] and total PANSS scores [t(38) = 0.21,P = 0.84].The two patient groups,as expected,varied significantly in the level of BIS-assessed insight [t(38) = 12.11,P < 0.001].MRI results revealed lower fronto-temporal,parahippocampal,occipital and cerebellar grey matter volumes in Insightpatients,relative to Insight+ patients and healthy controls(for all clusters,family-wise error corrected P < 0.05).Insight+ patient and healthy controls did not differ significantly(P > 0.20) from each other.CONCLUSION Our findings demonstrate a clear association between poor clinical insight and smaller fronto-temporal,occipital and cerebellar grey matter volumes in stable long-term schizophrenia patients.