[Impacts of Land Use Intensification Level on Fluvo-aquic Cropland Soil Microbial Community Abundance and Necromass Accumulation in North China].

Despite the essential role of soil microorganisms in nutrient turnover in soil ecological systems and the recognized paramount significance of microbial necromass to soil organic carbon accumulation, how microbial community abundance and necromass respond to land use intensification level regulation remains poorly understood. To address this knowledge gap, based on the land use intensification level, three treatments were set up[annual wheat-maize rotation (CC), alternating temporary grassland with wheat planting (TG), and perennial grassland (PG)], and a long-term fixed filed experiment was established to investigate the influences of the regulation of land use intensification level on bacterial and fungal community abundances; the accumulation of bacterial, fungal, and total microbial necromass; and their contributions to SOC sequestration using droplet digital PCR and amino sugar detection technologies. We further sought to determine the key factors driving the bacterial, fungal, and total microbial necromass C accumulation. Our results demonstrated that fungal community abundance was strongly affected by land use intensification level regulation compared to that of the bacterial community, which increased with decreasing land use intensification level. The total microbial necromass C predominated the SOC accumulation across all three land use intensification levels, which contributed 52.78%, 58.36%, and 68.87% to SOC, respectively, exhibiting an increasing trend with the decline in land use intensification level. Fungal necromass C accounted for more than 80% of the total microbial necromass C, indicating its predominance in the accumulation of the total microbial necromass C and active variation via the reduction in land use intensification level. There was no significant difference in bacterial necromass C (MurA) content, with the trend of CC

Neural stem cell-derived exosome as a nano-sized carrier for BDNF delivery to a rat model of ischemic stroke.

Our previous study demonstrated the potential therapeutic role of human neural stem cell-derived exosomes (hNSC-Exo) in ischemic stroke. Here, we loaded brain-derived neurotrophic factor (BDNF) into exosomes derived from NSCs to construct engineered exosomes (BDNF-hNSC-Exo) and compared their effects with those of hNSC-Exo on ischemic stroke both in vitro and in vivo. In a model of H2O2-induced oxidative stress in NSCs, BDNF-hNSC-Exo markedly enhanced cell survival. In a rat middle cerebral artery occlusion model, BDNF-hNSC-Exo not only inhibited the activation of microglia, but also promoted the differentiation of endogenous NSCs into neurons. These results suggest that BDNF can improve the function of NSC-derived exosomes in the treatment of ischemic stroke. Our research may support the clinical use of other neurotrophic factors for central nervous system diseases.

[Impacts of Co-application of Chemical Fertilizer Reduction and Organic Material Amendment on Fluvo-aquic Soil Microbial N-cycling Functional Gene Abundances and N-converting Genetic Potentials in Northern China].

The emerging environment-associated issues due to the overuse of inorganic fertilizers in agricultural production are of global concern despite the benefit of high yields. Eco-friendly organic materials with the capability to fertilize soil are encouraged to partially replace mineral fertilizer. The N cycle conducted by soil microorganisms is the most important biogeochemical process, dictating the N bioavailability in farmland ecosystems; however, little is known about how organic material amendment affects soil microbial N cycling under chemical fertilizer reduction. Hence, a fixed field trial with five fertilization practices was implemented to experimentally alter microorganisms essential for the soil N cycle, including conventional chemical fertilization (NPK), reduced chemical fertilization (NPKR), reduced chemical fertilization plus straw (NPKRS), reduced chemical fertilization plus organic fertilizer (NPKRO), and reduced chemical fertilization plus organic fertilizer and straw (NPKROS). The microbial N-cycling gene abundances and associated N-converting genetic potentials were evaluated using real-time quantitative PCR. In comparison to conventional chemical fertilization (NPK), organic addition significantly increased the amounts of heterotrophic microbes involved in organic N decomposition, N fixation, and N reduction; however, it reduced autotrophic microbes performing ammonia oxidization. Consequently, the overall proportion of heterotrophic microbes was remarkably enhanced, and the autotrophic proportion was correspondingly lowered. The fertilization practice shift significantly improved N fixation and gaseous N emission potentials, whereas it suppressed NO3- leaching potential. A significant discrepancy among five fertilization treatments was observed based on functional gene abundances (PERMANOVA, P=0.002),as revealed by distance-based redundancy analysis (db-RDA), with NH4+ as the dominant factor. Organic fertilizer addition was beneficial for heterotrophic N functional microorganisms, with simultaneous input of straw augmenting such an effect. Pearson's correlation analysis revealed that N storage and gaseous N emission potentials were both substantially negatively correlated with NH4+; NO3- leaching potential was notably negatively associated with SOC and TN but significantly related to NH4+. In conclusion, chemical fertilizer reduction combined with organic material amendments, a main fertilization recommendation, may enhance soil N storage, diminish N loss by leaching, and mitigate the environmental risk of N2O emission. This deserves attention considering that healthy and sustainable agricultural soil environment can be cultivated from the view of microbial N-cycling.

Acupuncture for emotional disorders in patients with inflammatory bowel disease: a systematic review protocol.

INTRODUCTION: Emotional disorders are often observed in inflammatory bowel disease (IBD). IBD with emotional disorders leads to poor quality of life. This systematic review aims to assess the effectiveness of acupuncture in patients with IBD with emotional disorders. METHODS AND ANALYSIS: Nine electronic databases, including Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Allied and Complementary Medicine Database, Cumulative Index to Nursing & Allied Health Literature, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Database and Wanfang Database, will be searched from inception to October 2021 without language restriction. The grey literature containing conference proceedings, as well as systematic reviews listed in the reference of definite publications, will also be retrieved. Randomised controlled trials either in English or Chinese reporting acupuncture therapy for IBD with emotional disorders will be included. The primary outcome is changes of emotional functioning outcomes. The Colitis Activity Index, Crohn's Disease Activity Index, C reactive protein and adverse events will be assessed as the secondary outcomes. More than two assessors will conduct the study retrieval and selection, as well as the data extraction and evaluation of the risk of bias. Data synthesis will be performed using a random-effects model based on the results of heterogeneity. Data analysis will be performed using RevMan software (V.5.4). Moreover, the dichotomous data will be presented as risk ratios, and the continuous data will be calculated using weighted mean difference or standard mean difference. ETHICS AND DISSEMINATION: This systematic review contains no individual patient data; thus, ethical approval is not required. Moreover, this review will be disseminated in a peer-reviewed journal or relevant conference. PROSPERO REGISTRATION NUMBER: CRD42020176340.

[Effects of tillage managements on soil microbial community structure in soil aggregates of fluvo-aquic soil]. / 耕作方式对潮土土壤团聚体微生物群落结构的影响.

In order to explore the impacts of different tillage managements on the structure and diversity of microbial community in fluvo-aquic soil, the phospholipid fatty acid (PLFA) method was used to determine microbial community composition in soil aggregates. Four tillage treatments were set up in Qihe County, Shandong Province, including rotary tillage with straw return (RT), deep ploughing with straw return (DP), subsoiling with straw return (SS) and no-tillage with straw return (NT). Our results showed that DP treatment significantly increased the amount of fungal PLFAs and fungi/bacteria ratio in >5 mm soil aggregates compared with RT. DP could provide favorable conditions for fungi reproduction, facilitate soil organic matter storage and soil buffering capacity. DP increased the amount of PLFAs in 5-2 mm soil aggregates, reduced the gram-positive (G+) /gram-negative (G-) bacteria ratio in the soil, and improved soil nutritional status. In addition, DP improved the microbial abundance index in <0.25 mm soil aggregates. In general, DP could not only increase the abundance of bacteria and fungi in soil aggregates, but also improve the microbial community structure of soil aggregate, which help increase soil carbon sequestration capacity and keep soil microbial diversity to a certain extent. Results of the redundancy analysis showed that the total PLFAs, PLFAs of bacteria, G- bacteria and actinomycetes in soil aggregates are closely correlated with soil organic carbon, while PLFAs of G+ bacteria had a strong correlation with soil total nitrogen concentration. In each treatment, microbial communities in larger sizes of soil aggregates were mainly affected by the ratio of organic carbon to total nitrogen, soil moisture, pH, and mass fractions of soil aggregates, while the microbial communities in smaller sizes of soil aggregates were affected by the concentrations of organic carbon and total nitrogen.

Role and mechanism of neural stem cells of the subventricular zone in glioblastoma.

Glioblastoma multiforme (GBM), the most frequently occurring malignant brain tumor in adults, remains mostly untreatable. Because of the heterogeneity of invasive gliomas and drug resistance associated with the tumor microenvironment, the prognosis is poor, and the survival rate of patients is low. Communication between GBMs and non-glioma cells in the tumor microenvironment plays a vital role in tumor growth and recurrence. Emerging data have suggested that neural stem cells (NSCs) in the subventricular zone (SVZ) are the cells-of-origin of gliomas, and SVZ NSC involvement is associated with the progression and recurrence of GBM. This review highlights the interaction between SVZ NSCs and gliomas, summarizes current findings on the crosstalk between gliomas and other non-glioma cells, and describes the links between SVZ NSCs and gliomas. We also discuss the role and mechanism of SVZ NSCs in glioblastoma, as well as the interventions targeting the SVZ and their therapeutic implications in glioblastoma. Taken together, understanding the biological mechanism of glioma-NSC interactions can lead to new therapeutic strategies for GBM.

Effect of conditioned medium from neural stem cells on glioma progression and its protein expression profile analysis.

BACKGROUND: Emerging evidence suggests that the spread of glioma to the subventricular zone (SVZ) is closely related to glioma recurrence and patient survival. Neural stem cells (NSCs) are the main cell type in the SVZ region and exhibit tumor-homing ability. AIM: To evaluate the effects of conditioned medium (CM) derived from SVZ NSCs on the cancer-related behaviors of glioma cells. METHODS: The characteristics of SVZ hNSCs were identified by immunofluorescence. The normoxic-hNSC-CM and hypoxic-hNSC-CM (3% O2, oxygen-glucose deprived [OGD] culturing) were collected from 80%-90% confluent SVZ NSCs in sterile conditions. The CCK8 and Transwell assays were used to compare and evaluate the effects of normoxic-CM and hypoxic-CM on glioma proliferation and invasion. Then proteins secreted from SVZ NSCs into the CM were investigated by mass spectrometry, and the potential effects of candidate protein NCAN in the regulation of glioma progression were examined by CCK8 and Transwell assays. RESULTS: The CM from SVZ NSCs significantly increased the proliferation and invasion of glioma cells, particularly the CM from OGD NSCs induced under hypoxic conditions. Furthermore, the secreted protein neurocan (NCAN) in CM from OGD NSCs was identified by proteomic analysis. NCAN was expressed in glioma cells and played regulatory roles in mediating the progression of glioma cells mainly via the Rho/Rho-associated protein kinase pathway. CONCLUSION: Our study identified a potential interactive mechanism between SVZ NSCs and glioma cells, in which SVZ NSCs promote glioma progression via the secreted protein NCAN. These findings suggested that exploring the CM derived from cells could be a novel strategy for optimizing treatments and that NCAN derived from SVZ NSCs may be a potential new target in glioma progression.

[Effects of Conversion of Forest to Arable Land on the Abundance and Structure of the cbbL-Harboring Bacterial Community in Albic Soil of the Hilly Region of Northeast China].

Soil CO2 fixer, which plays an important role in soil carbon cycling, can convert CO2 into organic matter. However, the effect of land-use change on the abundance and community structure of soil CO2 fixer is poorly understood. Examining the community of functional microbes that encode the large subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase under the conversion of land-use patterns may provide valuable information for promoting soil carbon sequestration ability and sustainable use. In this study, we investigated how the abundance and community diversity of the CO2-fixing bacteria responded to conversion of forest to arable land in the hilly region of Northeast China. We found that the abundance of soil cbbL-harboring bacteria was substantially lower in arable land (2.57×108 copies·g-1, soil) compared to forest (7.30×108 copies·g-1, soil), while the cbbL/16S rRNA gene ratio did not differ significantly between the two treatments. The values of the Shannon and Chao1 index decreased significantly with the conversion of forest to arable land, but the Simpson index was in contrast to these results. Neighbor-joining phylogenetic tree and principal coordinates analysis (PCoA) both demonstrated that the composition of the cbbL-harboring bacterial community was significantly affected by land-use change. Soil cbbL gene abundance and Shannon diversity significantly positively correlated with pH, and significantly negatively correlated with AP and NO3-, indicating that the changes in soil pH and available nutrients caused by land-use change greatly affected soil cbbL abundance and diversity. Meanwhile, pH, NO3-, available phosphorus (AP) and NH4+ significantly correlated with soil cbbL-harboring bacterial community structure. In conclusion, a 25-year long-term conversion of forest to arable land changed the community structure of soil cbbL-harboring bacteria, and soil pH, AP and available N played crucial roles in controlling the ecological properties of soil cbbL-harboring bacteria.

Neural stem cell transplantation therapy for brain ischemic stroke: Review and perspectives.

Brain ischemic stroke is one of the most common causes of death and disability, currently has no efficient therapeutic strategy in clinic. Due to irreversible functional neurons loss and neural tissue injury, stem cell transplantation may be the most promising treatment approach. Neural stem cells (NSCs) as the special type of stem cells only exist in the nervous system, can differentiate into neurons, astrocytes, and oligodendrocytes, and have the abilities to compensate insufficient endogenous nerve cells and improve the inflammatory microenvironment of cell survival. In this review, we focused on the important role of NSCs therapy for brain ischemic stroke, mainly introduced the methods of optimizing the therapeutic efficacy of NSC transplantation, such as transfection and overexpression of specific genes, pretreatment of NSCs with inflammatory factors, and co-transplantation with cytokines. Next, we discussed the potential problems of NSC transplantation which seriously limited their rapid clinical transformation and application. Finally, we expected a new research topic in the field of stem cell research. Based on the bystander effect, exosomes derived from NSCs can overcome many of the risks and difficulties associated with cell therapy. Thus, as natural seed resource of nervous system, NSCs-based cell-free treatment is a newly therapy strategy, will play more important role in treating ischemic stroke in the future.

[Effects of different fertilizer application on soil active organic carbon].

The variation characteristics of the content and components of soil active organic carbon under different fertilizer application were investigated in samples of calcareous fluvo-aquic soil from a field experiment growing winter wheat and summer maize in rotation in the North China Plain. The results showed that RF (recommended fertilization), CF (conventional fertilization) and NPK (mineral fertilizer alone) significantly increased the content of soil dissolved organic carbon and easily oxidized organic carbon by 24.92-38.63 mg x kg(-1) and 0.94-0.58 mg x kg(-1) respectively compared to CK (unfertilized control). The soil dissolved organic carbon content under OM (organic manure) increased greater than those under NPK and single fertilization, soil easily oxidized organic carbon content under OM and NPK increased greater than that under single chemical fertilization. OM and NPK showed no significant role in promoting the soil microbial biomass carbon, but combined application of OM and NPK significantly increased the soil microbial biomass carbon content by 36.06% and 20.69%, respectively. Soil easily oxidized organic carbon, dissolved organic carbon and microbial biomass carbon accounted for 8.41% - 14.83%, 0.47% - 0.70% and 0.89% - 1.20% of the total organic carbon (TOC), respectively. According to the results, the fertilizer application significantly increased the proportion of soil dissolved organic carbon and easily oxidized organic carbon, but there was no significant difference in the increasing extent of dissolved organic carbon. The RF and CF increased the proportion of soil easily oxidized organic carbon greater than OM or NPK, and significantly increased the proportion of microbial biomass carbon. OM or RF had no significant effect on the proportion of microbial biomass carbon. Therefore, in the field experiment, appropriate application of organic manure and chemical fertilizers played an important role for the increase of soil active organic carbon content and the effective control of its key components.

[Optimization of conservation network system for inter-basin wetland ecosystem in Huang-Huai-Hai Region].

By using systematic conservation planning (SCP) method, and taking catchment as planning unit, an optimization of conservation network system for the inter-basin wetland ecosystem in Huang-Huai-Hai Region was conducted, with a comprehensive consideration of 3-dimensional (lateral, longitudinal and vertical) connectivity and Inter-basin Water Transfer Project and by the methods of irreplaceability analysis and gap identification. The efficacy of the optimized conservation network system was evaluated, as compared with the existing conservation network system. According to the principles of irreplaceability and connectivity, the wetland conservation gaps could be divided into two types, i.e. , be conserved in priority and in general. After the optimization, the conservation status of the inter-basin wetland ecosystem in Huang-Huai-Hai Region had an overall improvement. The conserved percentage of the wetland types was from about 20% up to 46.8%, and, for each wetland type, its conserved level increased to some extent, almost above 40%. Both in the near future and in the long term, more attention should be paid to the conservation of lake wetland. In addition, the integration of ecosystem service function and biodiversity and the combination of protection with restoration would be the main task for the wetland ecosystem conservation planning in the future.