Ecosystem multifunctionality and soil microbial communities in response to ecological restoration in an alpine degraded grassland

Linkages between microbial communities and multiple ecosystem functions are context-dependent. However, the impacts of different restoration measures on microbial communities and ecosystem functioning remain unclear. Here, a 14-year long-term experiment was conducted using three restoration modes: planting mixed grasses (MG), planting shrub with Salix cupularis alone (SA), and planting shrub with Salix cupularis plus planting mixed grasses (SG), with an extremely degraded grassland serving as the control (CK). Our objective was to investigate how ecosystem multifunctionality and microbial communities (diversity, composition, and co-occurrence networks) respond to different restoration modes. Our results indicated that most of individual functions (i.e., soil nutrient contents, enzyme activities, and microbial biomass) in the SG treatment were significantly higher than in the CK treatment, and even higher than MG and SA treatments. Compared with the CK treatment, treatments MG, SA, and SG significantly increased the multifunctionality index on average by 0.57, 0.23 and 0.76, respectively. Random forest modeling showed that the alpha-diversity and composition of bacterial communities, rather than fungal communities, drove the ecosystem multifunctionality. Moreover, we found that both the MG and SG treatments significantly improved bacterial network stability, which exhabited stronger correlations with ecosystem multifunctionality compared to fungal network stability. In summary, this study demonstrates that planting shrub and grasses altogether is a promising restoration mode that can enhance ecosystem multifunctionality and improve microbial diversity and stability in the alpine degraded grassland

Linking between soil properties, bacterial communities, enzyme activities, and soil organic carbon mineralization under ecological restoration in an alpine degraded grassland

Soil organic carbon (SOC) mineralization is affected by ecological restoration and plays an important role in the soil C cycle. However, the mechanism of ecological restoration on SOC mineralization remains unclear. Here, we collected soils from the degraded grassland that have undergone 14 years of ecological restoration by planting shrubs with Salix cupularis alone (SA) and, planting shrubs with Salix cupularis plus planting mixed grasses (SG), with the extremely degraded grassland underwent natural restoration as control (CK). We aimed to investigate the effect of ecological restoration on SOC mineralization at different soil depths, and to address the relative importance of biotic and abiotic drivers of SOC mineralization. Our results documented the statistically significant impacts of restoration mode and its interaction with soil depth on SOC mineralization. Compared with CK, the SA and SG increased the cumulative SOC mineralization but decreased C mineralization efficiency at the 0–20 and 20–40 cm soil depths. Random Forest analyses showed that soil depth, microbial biomass C (MBC), hot-water extractable organic C (HWEOC), and bacterial community composition were important indicators that predicted SOC mineralization. Structural equal modeling indicated that MBC, SOC, and C-cycling enzymes had positive effects on SOC mineralization. Bacterial community composition regulated SOC mineralization via controlling microbial biomass production and C-cycling enzyme activities. Overall, our study provides insights into soil biotic and abiotic factors in association with SOC mineralization, and contributes to understanding the effect and mechanism of ecological restoration on SOC mineralization in a degraded grassland in an alpine region

Pedestal looseness extent recognition method for rotating machinery based on vibration sensitive time-frequency feature and manifold learning

To realize automation and high accuracy of pedestal looseness extent recognition for rotating machinery, a novel pedestal looseness extent recognition method for rotating machinery based on vibration sensitive time-frequency feature and manifold learning dimension reduction is proposed. Firstly, the pedestal looseness extent of rotating machinery is characterized by vibration signal of rotating machinery and its spectrum, then the time-frequency features are extracted from vibration signal to construct the origin looseness extent feature set. Secondly, the algorithm of looseness sensitivity index is designed to filter out the non-sensitive feature and poor sensitivity feature from the origin looseness extent feature set, avoiding the interference of non-sensitive and poor sensitivity feature. The sensitive features are selected to construct the looseness extent sensitive feature set, which has stronger characterization capabilities than the origin looseness extent feature set. Moreover, an effective manifold learning method called linear local tangent space alignment (LLTSA) is introduced to compress the looseness extent sensitive feature set into the low-dimensional looseness extent sensitive feature set. Finally, the low-dimensional looseness extent sensitive feature set is inputted into weight K nearest neighbor classifier (WKNNC) to recognize the different pedestal looseness extents of rotating machinery, the WKNNC’s recognition accuracy is more stable compared with that of a k nearest neighbor classification (KNNC). At the same time, the pedestal looseness extent recognition of rotating machinery is realized. The feasibility and validity of the present method are verified by successful pedestal looseness extent recognition application in a rotating machinery

Polyethylenimine nanogels incorporated with ultrasmall iron oxide nanoparticles and doxorubicin for MR imaging-guided chemotherapy of tumors

Development of versatile nanoplatforms for cancer theranostics remains a hot topic in the area of nanomedicine. We report here a general approach to create polyethylenimine (PEI)-based hybrid nanogels (NGs) incorporated with ultrasmall iron oxide (Fe3O4) nanoparticles (NPs) and doxorubicin for T1-weighted MR imaging guided chemotherapy of tumors. In this study, PEI NGs were first prepared using an inverse emulsion approach along with Michael addition reaction to cross-link the NGs, modified with citric acid stabilized ultrasmall Fe3O4 NPs through 1-ethyl-3-(3-(dimethylamino)- propyl) carbodiimide hydrochloride (EDC) coupling, and physically loaded with anticancer drug doxorubicin (DOX). The formed hybrid NGs possess good water dispersibility and colloidal stability, excellent DOX loading efficiency (51.4%), pH-dependent release profile of DOX with an accelerated release rate under acidic pH, and much higher r1 relaxivity (2.29 mM−1 s −1 ) than free ultrasmall Fe3O4 NPs (1.15 mM−1 s −1 ). In addition, in contrast to the drug-free NGs that possess good cytocompatibility, the DOX-loaded hybrid NGs display appreciable therapeutic activity and can be taken up by cancer cells in vitro. With these properties, the developed hybrid NGs enabled effective inhibition of tumor growth under the guidance of T1-weighted MR imaging. The developed hybrid NGs may be applied as a versatile nanoplatform for MR imaging-guided chemotherapy of tumors.info:eu-repo/semantics/publishedVersio

Ecosystem multifunctionality and soil microbial communities in response to ecological restoration in an alpine degraded grassland

Linkages between microbial communities and multiple ecosystem functions are context-dependent. However, the impacts of different restoration measures on microbial communities and ecosystem functioning remain unclear. Here, a 14-year long-term experiment was conducted using three restoration modes: planting mixed grasses (MG), planting shrub with Salix cupularis alone (SA), and planting shrub with Salix cupularis plus planting mixed grasses (SG), with an extremely degraded grassland serving as the control (CK). Our objective was to investigate how ecosystem multifunctionality and microbial communities (diversity, composition, and co-occurrence networks) respond to different restoration modes. Our results indicated that most of individual functions (i.e., soil nutrient contents, enzyme activities, and microbial biomass) in the SG treatment were significantly higher than in the CK treatment, and even higher than MG and SA treatments. Compared with the CK treatment, treatments MG, SA, and SG significantly increased the multifunctionality index on average by 0.57, 0.23 and 0.76, respectively. Random forest modeling showed that the alpha-diversity and composition of bacterial communities, rather than fungal communities, drove the ecosystem multifunctionality. Moreover, we found that both the MG and SG treatments significantly improved bacterial network stability, which exhabited stronger correlations with ecosystem multifunctionality compared to fungal network stability. In summary, this study demonstrates that planting shrub and grasses altogether is a promising restoration mode that can enhance ecosystem multifunctionality and improve microbial diversity and stability in the alpine degraded grassland

The use of a novel reduction plate in transoral anterior C1-ring osteosynthesis for unstable atlas fractures

BackgroundTransoral anterior C1-ring osteosynthesis has been reported as an effective treatment for unstable atlas fracture, which aims to preserve important C1–C2 motion. However, previous studies have shown that the anterior fixation plates used in this technique were not suitable for the anterior anatomy of the atlas and lacked an intraoperative reduction mechanism.ObjectiveThis study aims to evaluate the clinical effects of a novel reduction plate used in transoral anterior C1-ring osteosynthesis for unstable atlas fractures.Methods30 patients with unstable atlas fractures treated by this technique from June 2011 to June 2016 were included in this study. The patients' clinical data and radiographs were reviewed, and the reduction of the fracture, internal fixation placement, and bone fusion were assessed using pre- and postoperative images. The patients' neurological function, rotatory range of motion, and pain levels were evaluated clinically during follow-up.ResultsAll 30 surgeries were successfully performed, and the average follow-up duration was 23.5 ± 9.5 months (range 9–48 months). One patient suffered atlantoaxial instability during the follow-up and was treated with posterior atlantoaxial fusion. The remaining 29 patients had satisfactory clinical outcomes, with ideal fracture reduction, good screw and plate placement, well-preserved range of motion, neck pain alleviation and solid bone fusion. There were no vascular or neurological complications during the operation or follow-up.ConclusionsThe use of this novel reduction plate in transoral anterior C1-ring osteosynthesis is a safe and effective surgical option in the treatment of unstable atlas fractures. This technique offers an immediate intraoperative reduction mechanism, which provides satisfactory fracture reduction, bone fusion, and preservation of C1–C2 motion