Alkaline phosphatase (ALP) catalyzes the hydrolysis and transphosphorylation of a wide variety of phosphoric acid monoesters and plays an important role in clinical diagnosis. In this work, an ...ALP-responsive anodic electrochemiluminescence (ECL) system based on coreaction of CdSe nanoparticles (NPs) and triethylamine has been designed for facile detection of ALP. The substrate of ALP, i.e., phenyl phosphate salt, shows no effect on the ECL emission whereas its catalytic product of phenol may induce ECL inhibition. For the buffer containing phenyl phosphate, the ECL emission is found to decline in the presence of ALP with different incubation time. The mechanism investigations indicate that the deposition of the electropolymerized phenol products may compete with the electrophoretic-driven adsorption of CdSe NPs on glassy carbon electrode and induce the ECL inhibition, which can be demonstrated by scanning electron microscopy, energy dispersive spectrometry, and anodic stripping voltammetry. Therefore, an inhibition type strategy has been developed to sensitively detect ALP ranging from 0.5 to 6.4 nM (activity ca. 2–25 U/L), with a detection limit of 0.5 nM. The potential interference from the common proteins is negligible. The recovery of ALP in diluted serum samples ranges from 91 to 114%, implicating its potential applications in the complex biological matrixes.
Heavy metal pollution has threatened the ecological environment and human health, therefore, effective removal of these toxic pollutants from various complex substrates is of great significance. So ...far, adsorption is still one of the most effective approaches. Metal-organic frameworks (MOFs), which are porous crystalline materials consisting of metal ions or metal clusters and organic ligands through coordination bonds. Due to their high surface area, porosity, as well as good chemical/thermal stability, the materials have recently attracted great attention in environmental analytical chemistry. This review mainly focused on the recent studies about the applications of UiO series MOFs and their composites as the emerging MOFs, which have been used effectively for the adsorption and removal of diverse heavy metal ions from a variety of environmental samples as novel adsorption materials. Moreover, an elaboration about UiO-MOFs and its composites including the synthetic methods and the applications of these materials in the removal of heavy metal ions were presented in detail. In addition, the adsorption characteristics and mechanism of UiO-MOFs as solid sorbents for heavy metal ions were discussed, including adsorption isotherms equation, adsorption thermodynamics, and kinetics. To this end, the developing trends of MOF-based composites for the removal of heavy metal ions had also prospected. This review will provide a new idea for the study of the adsorption mechanism of heavy metal ions on sorbents and the development of high-performance media for the efficient removal of pollutants in wastewater.
•Synthetic methods of UiO series of metal-organic frameworks composites were reviewed.•The removal of heavy metal ions by UiO-MOFs as advanced sorbents were presented.•Adsorption isotherms equation, adsorption thermodynamics and kinetics were demonstrated.•The developing trends of MOFs for removal of heavy metal ions were prospected.
The increased global consumption of chicken products has resulted in the generation of huge amounts of manure. Numerous studies emphasized the large potential of this waste as an untapped source of ...renewable energy through anaerobic digestion (AD). However, intrinsic difficulties, in particular the high N content, induce instable process conditions, including the accumulation of intermediates, and foaming, which reduces methane yields. Such issues limit the widespread application of this energy-rich substrate for biogas production. The process inhibition by ammonia is usually prevented by reducing the concentration of chicken manure through dilution or by operating the plant considerably below its theoretical reactor capacity. However, this process compromises process efficiency, thereby increasing capital investments and operational costs. Another option to achieve optimal process performance is co-digestion with less N-rich materials. However, co-digestion also has its limitations due to the frequent unavailability of sufficient amounts of C-rich substrates. A series of promising technical solutions have been developed to overcome the aforementioned bottlenecks. Examples include stripping or membrane extraction as means to reduce ammonia concentration in the fermenter. Several full-scale plants employing ammonia removal techniques have been installed recently. Latest research also investigated the use of additives, such as zeolites and trace elements, as well as bioaugmentation, to mitigate ammonia inhibition. The current study reviews the state of technology as well as recent achievements and perspectives. It provides an overview of the different approaches to remove ammonia from AD-process and presents practical examples from China and Europe.
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•High N content chicken wastes induce instable digestion process conditions.•Current common approaches reduce the process efficiency or increase the costs.•Co-digestion could be an option with limitation of plenty amounts C-rich substrates.•Novel technologies such as stripping and membrane extraction are introduced.•Some typical practical examples from China and Europe are presented.
It is well known that an unhealthy lifestyle is a major risk factor for metabolic diseases, while in recent years, accumulating evidence has demonstrated that the gut microbiome and its metabolites ...also play a crucial role in the onset and development of many metabolic diseases, including obesity, type 2 diabetes, nonalcoholic fatty liver disease, cardiovascular disease and so on. Numerous microorganisms dwell in the gastrointestinal tract, which is a key interface for energy acquisition and can metabolize dietary nutrients into many bioactive substances, thus acting as a link between the gut microbiome and its host. The gut microbiome is shaped by host genetics, immune responses and dietary factors. The metabolic and immune potential of the gut microbiome determines its significance in host health and diseases. Therefore, targeting the gut microbiome and relevant metabolic pathways would be effective therapeutic treatments for many metabolic diseases in the near future. This review will summarize information about the role of the gut microbiome in organism metabolism and the relationship between gut microbiome-derived metabolites and the pathogenesis of many metabolic diseases. Furthermore, recent advances in improving metabolic diseases by regulating the gut microbiome will be discussed.
The validity of the Johnson–Cook constitutive relation and failure criterion at high strain rates, up to ∼106 s−1, was assessed by predicting the dynamic response of Ti–6Al–4V under high-speed ball ...impact at various velocities and angles. White-light scanning was performed to characterize impact craters formed on target surfaces. The measured crater was compared with that predicted by the corresponding finite element model developed using the finite element code Abaqus/Explicit. The target material behavior was modeled by the Johnson–Cook material model that induced both plastic deformation and damage mechanism. Good agreement was obtained between the experimental measurements and numerical predictions for all testing conditions.
Despite a relatively large number of studies on teachers’ identity development in the University-School community, few studies have explicitly focused on school EFL teachers’ research identity ...construction. This study adopts the Activity Theory and examines three English as a foreign language (EFL) teachers from three middle schools in a University–School community in China. It investigates how three teachers constructed their research identity and what factors influenced the construction of their identities within the University–School activity system from the dual perspectives of the school and university teachers. Data are collected through semi-structured narrative interviews, triangulated by documents such as meeting minutes, and then analyzed by NVivo 12. The findings of this study show that (1) the University–School collaborative program helps form a University–School community of both teaching and research; (2) in this community, school EFL teachers continuously construct their identities in a spiral process of “practitioner” and “researcher”; (3) it highlights the internal factors containing the research experience and the stage of career and the external factors including the curriculum reform context and the communication in the community. The findings carry important implications for school EFL teachers’ research identity construction and professional development in the University–School cooperation.
•Atmospheric N deposition in China was evaluated by two time-scale deposition databases.•Bulk and dry N deposition reached a peak between 2000 and 2010 and then began a steady decline.•Significant ...decrease of oxidized N deposition proved the effectiveness of NOx emissions control.•Increase of NH3 dry deposition highlighted the importance of regional NH3 mitigation.
China has experienced a dramatic change in atmospheric reactive nitrogen (Nr) emissions over the past four decades. However, it remains unclear how nitrogen (N) deposition has responded to increases and/or decreases in Nr emissions. This study quantitatively assesses temporal and spatial variations in measurements of bulk and calculated dry N deposition in China from 1980 to 2018. A long-term database (1980–2018) shows that bulk N deposition peaked in around 2000, and had declined by 45% by 2016–2018. Recent bulk and dry N deposition (based on monitoring from 2011 to 2018) decreased from 2011 to 2018, with current average values of 19.4 ± 0.8 and 20.6 ± 0.4 kg N ha−1 yr−1, respectively. Oxidized N deposition, especially dry deposition, decreased after 2010 due to NOx emission controls. In contrast, reduced N deposition was approximately constant, with reductions in bulk NH4+-N deposition offset by a continuous increase in dry NH3 deposition. Elevated NH3 concentrations were found at nationwide monitoring sites even at urban sites, suggesting a strong influence of both agricultural and non-agricultural sources. Current emission controls are reducing Nr emissions and deposition but further mitigation measures are needed, especially of NH3, built on broader regional emission control strategies.
The anti-hyperglycemic effect of metformin is believed to be caused by its direct action on signaling processes in hepatocytes, leading to lower hepatic gluconeogenesis. Recently, metformin was ...reported to alter the gut microbiota community in humans, suggesting that the hyperglycemia-lowering action of the drug could be the result of modulating the population of gut microbiota. However, the critical microbial signaling metabolites and the host targets associated with the metabolic benefits of metformin remained elusive. Here, we performed metagenomic and metabolomic analysis of samples from individuals with newly diagnosed type 2 diabetes (T2D) naively treated with metformin for 3 d, which revealed that Bacteroides fragilis was decreased and the bile acid glycoursodeoxycholic acid (GUDCA) was increased in the gut. These changes were accompanied by inhibition of intestinal farnesoid X receptor (FXR) signaling. We further found that high-fat-diet (HFD)-fed mice colonized with B. fragilis were predisposed to more severe glucose intolerance, and the metabolic benefits of metformin treatment on glucose intolerance were abrogated. GUDCA was further identified as an intestinal FXR antagonist that improved various metabolic endpoints in mice with established obesity. Thus, we conclude that metformin acts in part through a B. fragilis-GUDCA-intestinal FXR axis to improve metabolic dysfunction, including hyperglycemia.
The development of locally developed English language teaching (ELT) materials is believed to be conducive to meeting the requirements of local language education policies and practices, and to ...enhance learners’ agency. In China, in order to implement national educational policy of curriculum-based value education, many locally developed ELT materials have been recently developed. However, there is a paucity of empirical research concerning the actual effects of such materials in practice. This study presents an empirical study of a recently developed set of teaching materials in the context of curriculum-based value education by adopting an approach consisting of questionnaires and interviews to examine the attitudes and experiences of users of these materials. The findings revealed a range of challenges in the use of these materials, including issues related to language and content of the materials, the integration of ideological and value elements, and the development of multi-dimensional teaching materials. The article then proposes possible solutions from the perspectives of optimizing the writing community, carefully selecting teaching materials, innovating the integration of ideological and political elements, and improving the development of multi-dimensional teaching materials. A framework for the evaluation of locally developed ELT materials is also proposed, with the intention of offering a useful benchmark for enhancing the development of such materials.
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