28 research outputs found

    Data_Sheet_1_Structural and functional characteristics of soil microbial communities in response to different ecological risk levels of heavy metals.docx

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    ObjectiveThe potential ecological risk index (RI) is the most commonly used method to assess heavy metals (HMs) contamination in soils. However, studies have focused on the response of soil microorganisms to different concentrations, whereas little is known about the responses of the microbial community structures and functions to HMs at different RI levels.MethodsHere, we conducted soil microcosms with low (L), medium (M) and high (H) RI levels, depending on the Pb and Cd concentrations, were conducted. The original soil was used as the control (CK). High-throughput sequencing, qPCR, and Biolog plate approaches were applied to investigate the microbial community structures, abundance, diversity, metabolic capacity, functional genes, and community assembly processes.ResultThe abundance and alpha diversity indices for the bacteria at different RI levels were significantly lower than those of the CK. Meanwhile, the abundance and ACE index for the fungi increased significantly with RI levels. Acidobacteria, Basidiomycota and Planctomycetes were enriched as the RI level increased. Keystone taxa and co-occurrence pattern analysis showed that rare taxa play a vital role in the stability and function of the microbial community at different RI levels. Network analysis indicates that not only did the complexity and vulnerability of microbial community decrease as risk levels increased, but that the lowest number of keystone taxa was found at the H level. However, the microbial community showed enhanced intraspecific cooperation to adapt to the HMs stress. The Biolog plate data suggested that the average well color development (AWCD) reduced significantly with RI levels in bacteria, whereas the fungal AWCD was dramatically reduced only at the H level. The functional diversity indices and gene abundance for the microorganisms at the H level were significantly lower than those the CK. In addition, microbial community assembly tended to be more stochastic with an increase in RI levels.ConclusionOur results provide new insight into the ecological impacts of HMs on the soil microbiome at different risk levels, and will aid in future risk assessments for Pb and Cd contamination.</p

    Anodic Oxidation in Aluminum Electrode by Using Hydrated Amorphous Aluminum Oxide Film as Solid Electrolyte under High Electric Field

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    Dense and nonporous amorphous aluminum oxide (AmAO) film was deposited onto platinized silicon substrate by sol–gel and spin coating technology. The evaporated aluminum film was deposited onto the AmAO film as top electrode. The hydrated AmAO film was utilized as a solid electrolyte for anodic oxidation of the aluminum electrode (Al) film under high electric field. The hydrated AmAO film was a high efficiency electrolyte, where a 45 nm thick Al film was anodized completely on a 210 nm thick hydrated AmAO film. The current–voltage (<i>I</i>–<i>V</i>) characteristics and breakdown phenomena of a dry and hydrated 210 nm thick AmAO film with a 150 nm thick Al electrode pad were studied in this work. Breakdown voltage of the dry and hydrated 210 nm thick AmAO film were 85 ± 3 V (405 ± 14 MV m<sup>–1</sup>) and 160 ± 5 V (762 ± 24 MV m<sup>–1</sup>), respectively. The breakdown voltage of the hydrated AmAO film increased about twice, owing to the self-healing behavior (anodic oxidation reaction). As an intuitive phenomenon of the self-healing behavior, priority anodic oxidation phenomena was observed in a 210 nm thick hydrated AmAO film with a 65 nm thick Al electrode pad. The results suggested that self-healing behavior (anodic oxidation reaction) was occurring nearby the defect regions of the films during <i>I</i>–<i>V</i> test. It was an effective electrical self-healing method, which would be able to extend to many other simple and complex oxide dielectrics and various composite structures

    Mutation V65I in the β1 Subunit of the Nicotinic Acetylcholine Receptor Confers Neonicotinoid and Sulfoxaflor Resistance in Insects

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    Neonicotinoids have been widely used to control pests with remarkable effectiveness. Excessive insecticides have led to serious insect resistance. Mutations of the nicotinic acetylcholine receptor (nAChR) are one of the reasons for neonicotinoid resistance conferred in various agricultural pests. Two mutations, V65I and V104I, were found in the nAChR β1 subunit of two neonicotinoid-resistant aphid populations. However, the specific functions of the two mutations remain unclear. In this study, we cloned and identified four nAChR subunits (α1, α2, α8, and β1) of thrips and found them to be highly homologous to the nAChR subunits of other insects. Subsequently, we successfully expressed two subtypes nAChR (α1/α2/α8/β1 and α1/α8/β1) by coinjecting three cofactors for the first time in thrips, and α1/α8/β1 showed abundant current rapidly. Acetylcholine, neonicotinoids, and sulfoxaflor exhibited different activation capacities for the two subtypes of nAChRs. Finally, V65I was found to significantly reduce the binding ability of nAChR to neonicotinoids and sulfoxaflor through electrophysiology and computer simulations. V104I caused a decrease in agonist affinity (pEC50) but an increase in the efficacy (Imax) of nAChR against neonicotinoids and reduced the binding ability of nAChR to sulfoxaflor. This study provides theoretical and technical support for studying the molecular mechanisms of neonicotinoid resistance in pests

    Paleoenvironment and Organic Characterization of the Lower Cretaceous Lacustrine Source Rocks in the Erlian Basin: The Influence of Hydrothermal and Volcanic Activity on the Source Rock Quality

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    Lower Cretaceous lacustrine source rocks in the Erlian Basin are highly heterogeneous. It is important to assess and explain these heterogeneities for the reconstruction of paleoenvironments and the prediction of high-quality source rock distributions. In this study, well-logging, organic, and elemental geochemical data were comprehensively analyzed for the source rocks of Member 4 of the Aershan Formation (Fm) and Member 1 of the Tengger Fm in the southern Bayindulan (BNAN), southern Wulanhua (WLHs), Anan, Aer, and southern Wuliyasitai sags of the Erlian Basin. The variability in sedimentary environments, sources of organic matter of the source rocks in different sags, and the influence of hydrothermal and volcanic activity on the source rock quality in the Erlian Basin were assessed. The results reveal that the source rocks can be divided into four types of organic facies (A, B, BC, and C). Organic facies A–B present hydrogen indices (HIs) higher than 400 mg/g and are mainly composed of mudstone and thick (average thickness >50 m) dolomitic mudstone, with biomarkers characterized by a Pr/Ph ratio lower than 1.0, a gammacerane/C30 hopane (Gam/C30H) ratio higher than 0.2, and a C19 tricyclic terpane/C23 tricyclic terpane (C19/C23TT) ratio lower than 0.6. Organic facies BC–C are composed of mudstone with an HI < 400 mg/g, with biomarkers characterized by a Pr/Ph ratio higher than 0.8, a Gam/C30H ratio lower than 0.2, a C19/C23TT ratio higher than 0.6, and a sterane/hopane ratio lower than 0.4. Dolomitic mudstone belonging to organic facies A–B is mainly developed in the BNAN, WLHs, and Anan sag and is characterized by a fault-controlled distribution in the sag, a right-declined rare earth element pattern, and an enrichment in the elements of Ba, Cu, Zn, Fe, and Ni. The genesis of high HI dolomitic mudstone is associated with hydrothermal and volcanic activity because the hydrothermal fluid or hydrolysis of volcanic ash result in increasing input of reducing gas and soluble nutrient ions, thus promoting the formation of anoxic and saline Cretaceous lakes with high primary productivity

    Phosphatase and tensin homolog (PTEN) expression on oncologic outcome in renal cell carcinoma: A systematic review and meta-analysis

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    <div><p>The phosphatase and tensin homolog (<i>PTEN</i>) gene is suggested to be a dormant tumor suppressor. However, the prognostic value of the loss of <i>PTEN</i> expression in renal cell carcinoma (RCC) remains controversial. Therefore, we conducted a meta-analysis to evaluate the association of <i>PTEN</i> expression with the clinicopathological presentations and outcomes of patients with RCC through immunohistochemistry staining analysis. We systematically searched for relevant studies in PubMed, Web of Science, and Embase until March 2016. Data regarding clinical stage, pathological type, Fuhrman grade, overall survival (OS), progression-free survival (PFS), and disease-specific survival (DSS) was analyzed in the present study. In total, there were 12 studies with 2,368 patients included in this meta-analysis. The low <i>PTEN</i> expression in RCC was significantly associated with unfavorable DSS (HR = 1.568, 95% CI 1.015–2.242) in a random-effects model but not with OS (HR = 1.046, 95% CI 0.93–1.176) and PFS (HR = 1.244, 95% CI 0.907–1.704). Other results indicated that <i>PTEN</i> expression was not correlated with clinical stage, pathological type, and Fuhrman grade. This meta-analysis suggests that <i>PTEN</i> expression is of limited value in predicting the prognosis of patients with RCC for OS and PFS via immunohistochemistry staining analysis; and that for DSS, low <i>PTEN</i> expression is significantly associated with an unfavorable outcome.</p></div

    Sensitivity analysis for OS, PFS and DSS.

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    <p>a. Sensitivity analysis for OS; b. Sensitivity analysis for PFS; c. Sensitivity analysis for DSS.</p
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