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Background: Very few studies have been made to investigate functional activity changes in occult spastic diplegic cerebral palsy (SDCP). The purpose of this study was to analyze whole-brain resting state regional brain activity and functional connectivity (FC) changes in patients with SDCP. Methods: We examined 12 occult SDCP and 14 healthy control subjects using resting-state functional magnetic resonance imaging. The data were analyzed using Resting-State fMRI Data Analysis Toolkit (REST) software. The regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and whole brain FC of the motor cortex and thalamus were analyzed and compared between the occult SDCP and control groups. Results: Compared with the control group, the occult SDCP group showed decreased ReHo regions, including the bilateral frontal, parietal, and temporal lobes, the cerebellum, right cingulate gyrus, and right lenticular nucleus, whereas an increased ReHo value was observed in the left precuneus, calcarine, fusiform gyrus, and right precuneus. Compared with the control group, no significant differences in ALFF were noted in the occult SDCP group. With the motor cortex as the region of interest, the occult SDCP group showed decreased connectivity regions in the bilateral fusiform and lingual gyrus, but increased connectivity regions in the contralateral precentral and postcentral gyrus, supplementary motor area, and the ipsilateral postcentral gyrus. With the thalamus being regarded as the region of interest, the occult SDCP group showed decreased connectivity regions in the bilateral basal ganglia, cingulate, and prefrontal cortex, but increased connectivity regions in the bilateral precentral gyrus, the contralateral cerebellum, and inferior temporal gyrus. Conclusions: Resting-state regional brain activities and FC changes in the patients with occult SDCP exhibited a special distribution pattern, which is consistent with the pathology of the disease. Key Words: cerebral palsy, functional connectivity, magnetic resonance imaging, regional homogeneity, resting-state functional magnetic resonance imaging

Aluminum (Al) toxicity severely decreases plant growth and productivity in acidic soil globally. Ectomycorrhizal (ECM) fungi can promote host plant’s Al-tolerance by acting as a physical barrier or bio-filter. However, little information is available on the role of ECM fungus on Al immobilization with respect to Al-tolerance. This present study aimed to screen a promising indigenous ECM fungus with high Al-tolerance and to understand its role in Al immobilization related to Al-tolerance. Two ECM fungal strains (Lactarius deliciosus 2 and Pisolithus tinctorius 715) isolated from forest stands in Southwest China were cultured in vitro with 0.0, 1.0 or 2.0 mM Al addition for 21 days to compare their Al accumulation and Al-tolerance. Meanwhile, fungal mycelia were incubated in 0.037 mM Al3+ solutions, and then Al3+ concentrations in the solution were determined at time 2, 5, 10, 20, 40, 60, 120, 180, and 240 min, and the Al3+ immobilization characteristics were evaluated using the pseudo-first order, pseudo-second order and intraparticle diffusion models. Results showed that 1.0 or 2.0 mM Al3+ addition significantly increased fungal biomass production by 23% or 41% in L. deliciosus 2, not in P. tinctorius 715. Fungal Al3+ concentrations in L. deliciosus 2 and P. tinctorius 715 were significantly increased by 293% and 103% under 2.0 mM than under 1.0 mM Al3+ addition. The pH values in the culture solution were significantly decreased by 0.43 after 21 d fungus growth but no changes between these two fungi under the same Al3+ addition. Fungal Al3+ immobilization showed a three-stage trend with initially a rapid rate followed a relatively slower rate until reaching equilibrium. The pseudo-second order model was the best (R2 = 0.98 and 0.99 for L. deliciosus 2 and P. tinctorius 715) to fit the experimentally observed data among the three models. Compared to P. tinctorius 715, L. deliciosus 2 also had greater intercept value, cation exchange capacity (CEC), and extracellular Al3+ proportion in fungal mycelia. Additionally, bio-concentration on Al3+, active site numbers for Al3+, boundary layer thickness, CEC, and immobilization on the cell wall in fungal mycelia were involved in ECM fungal Al-tolerance. These results show that both ECM fungi are Al-tolerant while L. deliciosus 2 is a promising indigenous ECM isolate with higher Al-tolerance in Southwest China, and they can be hence applied to the afforestation and ecological restoration in acidic soil.

This is a novel study about responses of leaf photosynthetic traits and plant mercury (Hg) accumulation of rice grown in Hg polluted soils to elevated CO2 (ECO2). The aim of this study was to provide basic information on the acclimation capacity of photosynthesis and Hg accumulation in rice grown in Hg polluted soil under ECO2 at day, night, and full day. For this purpose, we analyzed leaf photosynthetic traits of rice at flowering and grain filling. In addition, chlorophyll content, soluble sugar and Malondialdehyde (MDA) of rice leaves were measured at flowering. Seed yield, ear number, grain number per ear, 1000-grain weight, total mercury (THg) and methylmercury (MeHg) contents were determined after harvest. Our results showed that Hg polluted soil and ECO2 had no significant effect on leaf chlorophyll content and leaf mass per area (LMA) in rice. The contents of soluble sugar and MDA in leaves increased significantly under ECO2. Mercury polluted soil treatment significantly reduced the light saturated CO2 assimilation rate (Asat) of rice leaves only at flowering, but not at grain filling. Night ECO2 greatly improved rice leaf water use efficiency (WUE). ECO2 greatly increased seed yield and ear number. In addition, ECO2 did not affect THg accumulation in rice organs, but ECO2 and Hg treatment had a significant interaction on MeHg in seeds, husks and roots.