[Response of Topsoil Fungal Community Structure to Soil Improvement Measures in Degraded Forest of Red Soil Region].

Soil fungal community structure and diversity are highly sensitive to variations in the external environment, as well as soil improvement measures. In order to clarify the effects of soil improvement measures on topsoil fertility or quality, a field experiment was conducted in eroded forest of a red soil region. Organic fertilizer, biochar, and lime+microbial fertilizer were added to the topsoil, respectively. After four years, the chemistry properties and nutrients in the topsoil were measured, and the diversity and composition of fungi were analyzed. The results showed that the additions of organic fertilizer, biochar, and lime+microbial fertilizer reduced fungal richness in topsoil, compared to that with no fertilizer addition (CK). Among them, lime+microbial fertilizer had the most negative effect on fungal richness. The three soil improvement measures also affected the diversity of topsoil fungi, but the impacts were not significant. The dominant fungal phyla in the topsoil were Ascomycota (31.29%-46.55%) and Basidiomycota (30.07%-70.71%), and the dominant fungal genera were Amphinema and Archaeorhizomyces. The effects of soil improvement measures on fungal community structure in the topsoil were different; organic fertilizer increased the relative abundance of Ascomycetes and Archaeopteroides, and biochar enhanced the relative abundance of Basidiomycetes and Archaeopteroides, whereas lime+microbial fertilizer improved the relative abundance of Basidiomycetes and Archaeopteroides. Fungal diversity and community structure in the topsoil was affected by edaphic factors, and fungal richness was regulated by pH value, whereas fungal community structure was influenced by pH, total nitrogen, and organic carbon. This study provides scientific guidance for soil improvement and ecological restoration below the canopy in eroded forests of red soil regions.

Low Serum Superoxide Dismutase Is Associated With a High Risk of Cognitive Impairment After Mild Acute Ischemic Stroke.

Background: Post-stroke cognitive impairment (PSCI) is a common complication after stroke, but effective therapy is limited. Identifying potential risk factors for effective intervention is warranted. We investigated whether serum superoxide dismutase (SOD) levels were related to cognitive impairment after mild acute ischemic stroke (AIS) by using a prospective cohort design. Methods: A total of 187 patients diagnosed with mild AIS (National Institutes of Health Stroke Scale ≤ 8) were recruited. Serum SOD, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and interleukin-6 (IL-6) levels were measured, and cognitive assessments (Mini-Mental State Examination, MMSE; Montreal Cognitive Assessment, MoCA) were performed in the early phase (within 2 weeks). These indexes and assessments were repeated at 3 months after onset. MoCA < 22 was defined as early cognitive impairment (CI-E) within 2 weeks and late cognitive impairment (CI-L) at 3 months after stroke. Results: In a survey, 105 of 187 (56.1%) patients were identified as CI-E after mild AIS. Lower serum SOD associated with higher inflammatory biomarkers (ESR, CRP, and IL-6) and worse cognitive scores was observed in CI-E patients. In a survey, 39 of 103 (37.9%) stroke patients who completed the 3-month follow-up were identified as CI-L. Serum SOD was consistently lower in CI-L patients at baseline and 3 months and positively associated with cognitive scores. In adjusted analyses, low serum SOD at baseline was independently associated with high risks of CI-E and CI-L, with odds ratios (ORs) of 0.64 and 0.33 per standard deviation increase in serum SOD, respectively. Multiple-adjusted spline regression models showed linear associations between serum SOD and CI-E (P = 0.044 for linearity) and CI-L (P = 0.006 for linearity). Moreover, 35.2% (19/54) of CI-E patients cognitively recovered during the 3-month follow-up. In multivariable analysis, SOD was identified as a protective factor for cognitive recovery after stroke (OR 1.04, 95% CI: 1.01-1.08, P = 0.024). Conclusion: We demonstrate that low serum SOD is associated with a high risk of cognitive impairment after mild AIS, indicating SOD may be a potential modifiable factor for PSCI.

Effect of photoperiod change on chronobiology of cercarial emergence of Schistosoma japonicum derived from hilly and marshy regions of China.

The chronobiology of cercarial emergence appeared to be a genetically controlled behavior, adapted to definitive host species, for schistosome. However, a few physiological and ecological factors, for example the change of photoperiod, were reported to affect the rhythmic emergence of cercariae. Therefore, the effect of photoperiod change on cercarial emergence of two Schistosoma japonicum isolates, the hilly and the marshland, was investigated. Four shedding experiments each under a different photoperiod were conducted. Under a natural photoperiod, two distinct shedding modes, one from the hilly region and one from the marshland, were observed. Under a reversed photoperiod, the regular pattern (i.e. under a natural photoperiod) of S. japonicum cercarial emergence was reversed for the marshland isolate and disappeared for the hilly isolate. With an input of a 2 h darkness from 7am to 9am, the cercarial emergence peak were delayed for the two isolates; whereas with an input of a 2 h darkness from 5pm to 7pm, neither effect on the cercarial emergence rhythm was observed. The total cercariae emerged for both parasite isolates varied with a different photoperiod. The results indicate that the change of photoperiod could affect the chronobiology of S japonicum cercarial emergence.

[Cloning, expression and antigenic analysis of merozoite surface protein MSPDBL2-DBL2 domain from Plasmodium falciparum].

OBJECTIVE: To clone and express the DBL domain of Plasmodium falciparum merozoite surface protein MSPDBL2(DBL2), and investigate its antigenicity. METHODS: The DBL2 fragment was amplified by PCR and cloned into pET28a vector. The recombinant pET28a-DBL2 plasmid was transformed into E. coli BL21 (DE3) and protein expression was induced by IPTG. The expressed product was purified by Ni-NTA affinity chromatography, and analyzed by SDS-PAGE and Western blotting. RESULTS: DBL2 gene fragment of Plasmodium falciparum merozoite surface protein MSPDBL2 (950 bp) was obtained by PCR. The recombinant pET28a-DBL2 plasmid was identified by PCR, double enzyme digestion, and DNA sequencing. The recombinant DBL2 protein was expressed in an inclusion body form with Mr 340,000 after being induced with IPTG. Moreover, the purified recombinant DBL2 protein was recognized by sera from patients with falciparum malaria. CONCLUSION: The recombinant pET28a-DBL2 plasmid has been constructed. The purified rDBL2 protein shows adequate antigenicity.