Investigating the addition of Fe for improving contaminant removal and regulating microbes in a simulated coastal wetland.

Contaminants from wastewater of aquaculture are increasing the risks of red tides in coastal areas. Such types of contaminants are difficult to remove by using conventional biological and ecological treatment methods because of the relatively low C/N ratios and the high salinity in coastal water ambience. Fe is considered a key element in natural chemical cycling and promotes the growth of animals and plants as well. The cycling of Fe ion combined with carbon, nitrogen, and phosphorus stimulates bacterial growth. As a result, it acts as a microbial carbon pump in coastal areas, such as natural wetlands, which have been activated and adapted to be salinity resistant and insufficient energy supply. Along these lines, in this work, constructed wetlands (CWs) with high ecological benefits and low cost of maintenance were used to treat aquaculture wastewater. The impact of Fe ion recycling on multiple contaminants was also systematically investigated. The two types of Fe dosage were pure ferrous ions and a mixture of iron powder and ferrous ions. After the application of a 3-day treatment, the dosage of iron powder/ferric ions (1:1 m/m) at a concentration of 15 mg L-1 showed a better effect, where the total nitrogen, total phosphorus, and chemical oxygen demand removal rates were increased by 2.95%, 2.16%, and 9.76%, respectively. From the microbial analysis, it was indicated that Fe ion affected the abundance and functions of the microbial communities in the CWs. The significant enrichment of Proteobacteria promoted the removal of multiple contaminants under saline stress and fixed carbon, and affected the whole microbe distribution and diversity in CWs. The implementation of such an environmentally friendly and economical approach arises as a promising candidate for the efficient removal of multiple contaminants from aquacultural wastewater in coastal zones.

Augmentation of saline wastewater treatment via functional enrichment of bacteria and optimized distribution in constructed wetlands combined with slag-sponges at different temperatures.

China's aquatic environment continues to face several difficulties. Ecological constructed wetland systems (CWs) can be used to treat polluted saline water to alleviate water shortages regionally and globally. However, the performance is limited by low temperatures. To expand the use of CWs, we introduced a slag-sponge, a flaky material derived from alkaline waste slag, to create a newly constructed wetland system that can operate at both low and high temperatures. We evaluated its effectiveness by placing it at different heights in our devices. The results showed that the treatment was effective for saline wastewater with multiple contaminants. The efficiency was 20% higher than that of traditional CWs. Slag-sponges were found to carry pore structures and exhibit thermal insulation, which led to the enrichment of functional microbial communities (Chryseobacterium and Exiguerium) at low temperatures according to the microbial species analysis. The enhanced CWs offer another option for the treatment of polluted saline water in the environment and provide promising strategies for the utilization of waste slag.

CoP2O6-Assisted Copper/Carbon Catalyst for Electrocatalytic Reduction of CO2 to Formate.

Reducing CO2 into value-added chemicals and fuels by electrochemical reduction of CO2 (CO2ER) in an aqueous medium is considered a potential way to store intermittent renewable energy and alleviate the energy crisis. Cu-based catalysts are a common electrocatalyst used in CO2ER. However, selectivity has always been a difficult problem to solve, especially in terms of the production of C1 products. Based on the characteristics of the carbon framework and the CoP2O6 species, herein, Cu and CoP2O6 co-anchored N-doped hollow carbon spheres (CoP2O6/HCS-Cu) with a precisely controllable copper content were prepared, in order to produce formate with a high current density and Faraday efficiency from CO2ER. The ratio of copper to cobalt has a strong influence on the catalytic performance of the catalyst. In addition, the experimental results and density functional theory calculations show that CoP2O6 is an important factor in promoting the formation of formate.

Effects of two plant species combined with slag-sponges on the treatment performance of contaminated saline water in constructed wetland.

Constructed wetland (CW), an ecological water treatment system, can purify and repair the damaged saline water body in an open watershed, but its repairing function is limited at low temperature under salt stress. In this study, two different plant species with slag-sponge layer were operated to enhance the purification effect of CW on the damaged saline water body. The results showed that the combination of Scirpus mariqueter and slag-sponges in CW had a better purification effect especially under the condition of salinity of 10‰ (S = 10) with a respective removal efficiency of 91.04% of total nitrogen, 80.07% of total phosphorus, and 93.02% of COD in high temperature (25 ~ 35 °C). Furthermore, ecological traits (enzyme activity and amino acids) of plants, the abundance and distribution of functional microorganisms on the surface of slag-sponges, and the microbial state on the substrate surface of the denitrifying zone of CW were analyzed to explain how exactly the combinations worked. It was found that the enrichment of functional microorganisms in slag-sponge and the anaerobic zone of plants have improved the nitrogen and phosphorus removal. Plants maintained high enzyme activities and the ability to synthesize key amino acids under salt stress to ensure the growth and reproduction of plants and achieve the assimilation function. Scirpus mariqueter combined with slag-sponges in CW effectively improved the purification effect of damaged saline water, indicating that it is an ecological and green saline water treatment way.

In-situ activator-induced evolution of morphology on carbon materials for supercapacitors.

Carbonaceous materials with diverse morphologies have shown unique and excellent performance in many fields, such as catalysis, adsorption, separation and energy storage. However, regulating the structural changes of these morphologies accurately using simple approaches is a difficult process. In this study, porous carbon materials with a morphology that changed from carbon spindles to fold-carbon spheres and then to regular carbon spheres were prepared assisted by in-situ activator of KNO3 in co-assembly of resorcinol/phenol resin and 1-alkyl-3-methylimidazolium bromide. The activation of KNO3 greatly improves the hydrophily, pore volume and surface area of the inert carbon skeleton, and increases heteroatom defects for the carbon framework. As electrode materials of supercapacitors, the influence of different structures on energy storage performance was studied. The obtained fold-carbon spheres showed a higher capacitance (405 F g-1) than flake, spindle and spherical porous carbon, which is due to convenient electrolyte transmission and completely available active sites.

Advances in microbial electrochemistry-enhanced constructed wetlands.

Constructed wetland (CW) is an effective ecological technology to treat water pollution and has the significant advantages of high impact resistance, simple construction process, and low maintenance cost. However, under extreme conditions such as low temperature, high salt concentration, and multiple types of pollutants, some bottlenecks exist, including the difficulty in improving operating efficiency and the low pollutant removal rate. Microbial electrochemical technology is an emerging clean energy technology and has the similar structure and pollutant removal mechanism to CW. Microbial electrochemistry combined with CW can improve the overall removal effect of pollutants in wetlands. This review summarizes characterization methods of microbial electrochemistry-enhanced constructed wetland systems, construction methods of different composite systems, mechanisms of single and composite systems, and removal effects of composite systems on different pollutants in water bodies. Based on the shortcomings of existing studies, the potential breakthroughs in microbial electrochemistry-enhanced constructed wetlands are proposed for developing the optimization solution of constructed wetlands.

Almost Sure Stability of Complex-Valued Complex Networks: A Noise-Based Delayed Coupling Under Random Denial-of-Service Attacks.

This article is concerned with stability for stochastic complex-valued delayed complex networks under random denial-of-service (RDoS) attacks. Different from the existing literature on the stability of stochastic complex-valued systems that concentrate on moment stability, we investigate almost sure stability (ASS), where noise plays a stabilizing role. It is noted that, besides the vertex systems influenced by noise, the interactions among vertices are also at the mercy of noise. As a consequence, an innovative noise-based delayed coupling (NDC) in the presence of RDoS attacks is proposed first to accomplish the stability of complex-valued networks, where the RDoS attacks have a certain probability of triumphantly interfering with communications at active intervals of attackers. Namely, RDoS attacks considered are randomly launched at active periods, which is more realistic. In terms of the Lyapunov method and stochastic analysis theory, an almost sure exponential stability (ASES) criterion of the system discussed straightforwardly is developed by constructing a delay-free auxiliary system, while removing the traditional assumption of moment stability. The criterion strongly linked with topological structure, RDoS frequency, attack successful probability, and noise intensity reveals that the higher the noise intensity, the faster the convergence rate is for the stability of the network. In light of the criterion established, we present an algorithm that can be employed to analyze the tolerable attack parameters and the upper bound of the coupling delays, under the prerequisite of guaranteeing the stability of the network. Eventually, the theoretical results are applied to inertial complex-valued neural networks (ICNNs) and an illustrative example is presented to substantiate the efficiency of the theoretical works.

Reasonable Construction of Hollow Carbon Spheres with an Adjustable Shell Surface for Supercapacitors.

Hollow carbon spheres (HCS) manifest specific merit in achieving large interior void space, high permeability, wide contactable area, and strong stacking ability with negligible aggregation and have attracted attention due to their high supercapacitor activity. As the key factor affecting supercapacitor performance, the surface chemical properties, shell thickness, roughness, and pore volumes of HCS are the focus of research in this field. Herein, the surface chemical properties and structures of HCS are simultaneously adjusted by a feasible and simple process of in situ activation during assembly of resin and potassium chloride (KCl). This strategy involves KCl participating in resin polymerization and the superior performance of potassium species on activating carbon. The surface N/O content, thickness, defects, and roughness degree of HCS can be controlled by adjusting the dosage of KCl. Electrochemical tests show that optimized HCS has suitable roughness, high surface area, and abundant surface N/O functional groups, which endow it with excellent electrochemical capacitance properties, showing its high potential in supercapacitors.

Potentiometric aptasensing of Escherichia coli based on electrogenerated chemiluminescence as a highly sensitive readout.

We introduce here a versatile approach to read out potentiometric aptasensors by electrogenerated chemiluminescence (ECL), which can amplify the small potential changes induced by the bacterial concentrations via ECL signals. In the present system, the electrode modified with single-walled carbon nanotubes (SWCNTs) and aptamer molecules acts as the reference electrode and is placed in the sample solution for sensing the bacterial concentration changes, while the Ru(bpy)32+ modified gold electrode serves as the working electrode for generating ECL signals and is placed in the detection solution containing tripropylamine (TPA) spatially separated from the sample solution by a salt bridge. Ru(bpy)32+ is immobilized on the gold electrode's surface for enhancement of luminous efficiency and reduction of reagent consumption. A moving-part-free fluid flowing system is introduced to promote the mass transport of TPA from the detection solution to the surface of the ECL generating electrode. When a constant potential is imposed between the working and reference electrodes, the potential changes at the SWCNTs-aptamer modified electrode induced by the bacterial concentrations can modulate the potentials at the Ru(bpy)32+ modified electrode, thus generating the ECL signals. The developed sensing strategy shows a highly sensitive response to E. coli O157: H7 in the linear range of 5-1000 CFU mL-1 with a low detection limit of 2 CFU mL-1. We believe that the proposed approach is promising to develop aptasensors for sensitive detection of bacterial cells.

Encapsulating Ru(bpy)32+ in an infinite coordination polymer network: Towards a solid-state electrochemiluminescence sensing platform for histamine to evaluate fish product quality.

In this work, we demonstrate a novel solid-state electrochemiluminescence (ECL) sensor based on the Ru(bpy)32+@terbium-guanosine monophosphate infinite coordination polymer network ((Ru(bpy)32+@Tb-GMP ICPn). Comparing with the traditional luminescence of Ru(bpy)32+ observed in a liquid system, the proposed method of encapsulating Ru(bpy)32+ into ICPn for immobilization greatly improves the ECL signal and efficiency, which is attributed to the unique porous structure and large specific surface area of ICPn. Moreover, the solid-state Ru(bpy)32+ ECL sensor has good biocompatibility and low toxicity. Taking histamine (HA) as a detection model, a good linear relationship between ECL intensity and logarithm of HA concentration was obtained with a low detection limit of 17 nM, and satisfactory results were obtained for detecting HA levels in fish samples as well. The proposed solid-state Ru(bpy)32+ ECL sensor has great application prospects in the safety of food.

Identification of sequence polymorphisms in the mitochondrial deoxyribonucleic acid displacement-loop region as risk factors for systemic lupus erythematosus.

OBJECTIVES: This study aims to evaluate the relationship between sequence polymorphisms (SNPs) in the displacement-loop (D-loop) region of mitochondrial deoxyribonucleic acid (mtDNA) and systemic lupus erythematosus (SLE) in Chinese female patients. PATIENTS AND METHODS: This cross-sectional study was conducted between May 2017 and October 2017. The mtDNA was extracted from the peripheral blood of 97 female SLE patients (mean age 40.8 years; range, 20 to 79 years) and 108 age-matched healthy controls (mean age 48.7 years; range, 22 to 78 years). The SNPs of mtDNA D-loop were verified by polymerase chain reaction amplification and sequence analysis. The allele frequencies of D-loop region were compared by the Chi-square test between SLE and control groups. RESULTS: The SNP accumulation in SLE patients was significantly higher than that in the controls (p=0.027, 95% confidence interval [CI]: 0.075, 1.210). The frequencies of the major alleles of the nucleotides 73G/A (p<0.001, odds ratio [OR]=1.241) and 195T/C (p=0.047, OR=4.318) as well as the minor allele of nucleotide 199T/C (p=0.048, OR=0.279) were significantly higher in the SLE patients than in the controls, which indicated that 73G, 195T and 199C allele in the D-loop of mtDNA were associated with the risk of SLE. Further analysis indicated that the reactive oxygen species level in the SLE patients was significantly higher than that of controls (mean fluorescence intensity ± standard deviation: 3054.333±256.099 vs. 2099.167±599.662, p=0.009, 95% CI: 321.243, 1589.091). CONCLUSION: This study indicated the SNPs in the mtDNA may associated with the risk of SLE. Analysis of SNPs in the mitochondrial D-loop may help identify individuals who are at high risk of developing SLE.

Silica-Assisted Controlled Engineering of Nitrogen-Doped Carbon Cages with Bulges for High-Performance Supercapacitors.

The bulge structure of N-doped carbon cages is beneficial to improving the specific surface area and increasing the active sites of a chemical reaction. Therefore, this structure plays a role in increasing capacity in energy storage. However, the precise and most effective method of ensuring the bulge structures is still a challenge. Herein, a silica-assisted method is used to prepare N-doped carbon cages with bulges. The effective assembly of a nitrogen-rich resin and silica precursor is employed to construct the bulge structure on the surface. The reaction temperature of the assembly system and the amount of silica precursor are the key influences on the number and degree of bulges. In contrast to conventional carbon materials that have a smooth surface, the bulge structure allows for exposure and accessibility of the activity sites. Due to the N-doping features, a rich mesoporous structure and controllable bulges, the synergism of the high density, large ion-accessible surface area, and fast charge transfer, lead to high performance under the premise of high rate capability in supercapacitor. This silica-assisted strategy can also work on other preprepared corresponding templates that have a different architecture to prepare core-shell carbon tubes, carbon spheres, and carbon rods with a bulge structure.

Synthesis of europium(iii)-doped copper nanoclusters for electrochemiluminescence bioanalysis.

An electrochemiluminescence biosensor based on europium(iii)-doped copper nanoclusters was proposed for the first time to achieve rapid and sensitive bioanalysis, using dopamine detection as a model.

NiFe Oxalate Nanomesh Array with Homogenous Doping of Fe for Electrocatalytic Water Oxidation.

NiFe-based materials have shown impressive electrocatalytic activity for the oxygen evolution reaction (OER). The mutual effect between proximate Ni and Fe atoms is essential in regulating the electronic structure of the active site to boost the OER kinetics. Detailed studies confirm that the separated monometal phases in NiFe-based materials are detrimental to OER. Thus, the high-level blending of Ni and Fe in NiFe-based OER electrocatalysts is critical. Herein, an NiFe oxalate nanomesh array based on solid solutions between nickel (II) oxalate and iron (II) oxalate is prepared through a facile surfactant-free approach in the presence of the reductive oxalate anions. The integrated electrode can efficiently catalyze water oxidation to reach a current density of 50 mA cm-2 with a small overpotential of 203 mV in a 1.0 m KOH aqueous solution. The high efficiency can be attributed to the atomic level mix of Ni and Fe in the solid solutions and the hierarchical porous structure of the nanomesh array. These two aspects bring about fast kinetics, efficient mass diffusion, and quick charge transfer, which are the three major positive factors for a high-performance heterogenous electrocatalyst.

A specific electrochemiluminescence sensor for selective and ultra-sensitive mercury(ii) detection based on dithiothreitol functionalized copper nanocluster/carbon nitride nanocomposites.

Electrochemiluminescence (ECL) sensors are useful for the detection of heavy metal pollutants, in particular mercury(ii) ions, in water samples. We demonstrate the superior sensing performance of Hg2+ using a nanocomposite material based on carbon nitride nanosheets (CNNSs) and copper nanoclusters functionalized by dithiothreitol, which not only stabilizes the clusters, but also improves the sensitivity of Hg2+ detection. The ECL mechanism is related to the reaction of the nanocomposite with K2S2O8 in the electrochemical system, while the presence of Hg2+ leads to quenching of its excited state, and the suppression of the formation of anion-radicals. The Hg(ii) sensor presented here is cheap and fast, and shows high selectivity for the detection of Hg2+ on the background of other mono-, di-, and trivalent ions, with a linear range of 0.5-10 nM and the detection limit as low as 0.01 nM.

Manganese(ii) phosphate nanosheet assembly with native out-of-plane Mn centres for electrocatalytic water oxidation.

Nature selects Mn-clusters as catalysts for water oxidation, which is a significant reaction in photosynthesis. Thus, it is of critical importance to develop Mn-based superstructures and study their catalytic details for water-splitting-based renewable energy research. Herein, we report a manganese(ii) phosphate nanosheet assembly with asymmetric out-of-plane Mn centers from the transformation of amine-intercalated nanoplates for efficient electrocatalytic water oxidation in neutral aqueous solutions. From structural and computational studies, it is found that the native out-of-plane Mn centers with terminal water ligands are accessible and preferential oxidation sites to form active intermediates for water oxidation. In addition, the asymmetry can stabilize the key MnIII intermediate, as demonstrated by electrochemical and spectrometric studies. This study delivers a convenient strategy to prepare unique nanosheet assemblies for electrocatalysis and fundamental understandings of oxygen evolution chemistry.

Conductive Molybdenum Sulfide for Efficient Electrocatalytic Hydrogen Evolution.

Molybdenum sulfide (MoS2 ) is a layered material with high activity for electrocatalytic hydrogen evolution reaction (HER). In conventional MoS2 , the high electrical resistance between the layers hampers the bulk charge transfer and therefore greatly limits its performance in electrolysis. Herein, ultrathin MoS2 nanosheets with bent layers on reduced graphene oxide (RGO) are reported. In sharp contrast to the bulk MoS2 , the resulting MoS2 has mostly 1 or 2 layers, and the layer distance is significantly expanded to ≈1 nm. From computational studies, the prepared MoS2 with limited layer numbers and expanded layer distances has similar physical and chemical features with single-layer MoS2 . Importantly, the bent single layer is electrically conductive and is intrinsically more active than a normal flat single layer. In addition, the unusual features of confined sizes and distorted lattices in the prepared MoS2 can bring about plentiful active sites and are beneficial for mass diffusion during electrocatalysis. The hybrid material exhibits high activity for electrocatalytic HER, affording a current density of 10 mA cm-2 at a low overpotential of 66 mV.

Ischemic colitis caused by polycythemia vera: A case report and literature review.

Polycythemia vera (PV) is a chronic myeloproliferative disorder originating from hematopoietic stem cells and complicated by thrombosis and bleeding. This report describes a case of ischemic colitis (IC) caused by PV and includes a review of the relevant literature. The patient was a 59-year-old male with a history of PV who presented with abdominal pain and hematochezia. Colonoscopy and histopathological examination results indicated suspected ischemic bowel disease. Following experimental anticoagulant therapy for 7 days, the patient no longer experienced abdominal pain and hematochezia had resolved. Colonoscopy review showed no obvious anomalies 1 month later. These data demonstrated that PV is an uncommon cause of IC.

Hollow Mesoporous Silica@Metal-Organic Framework and Applications for pH-Responsive Drug Delivery.

Metal--organic frameworks (MOFs), a new type of porous crystalline material, hold great potential in biomedical applications, such as drug delivery. However, the efficacy of drug delivery is limited by low drug loading. In this work, we synthesized hollow mesoporous silica (HMS)@MOF capsules that can be used as a pH-responsive drug delivery system for the anticancer drug doxorubicin (DOX). DOX is loaded into the inner cavity of HMS. Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles are then coated on the outer surface of the DOX-loaded HMS. The obtained material is a capsule (denoted as DOX/HMS@ZIF), in which DOX is encapsulated. The DOX/HMS@ZIF can be used as an efficient pH-responsive drug delivery system. DOX is not released under physiological conditions (pH 7.4), but is released at low pH (4-6) from DOX/HMS@ZIF. The DOX/HMS@ZIF capsule shows much higher cytotoxicity than free DOX and alters the delivery pathway for DOX in cancer cells, while the drug-free HMS@ZIF shows excellent biocompatibility. This opens new opportunities to construct a safe and efficient delivery system for targeted molecules using pH-responsive release for a wide range of applications.

Graphene-Supported Pyrene-Modified Cobalt Corrole with Axial Triphenylphosphine for Enhanced Hydrogen Evolution in pH†0-14 Aqueous Solutions.

A cobalt complex of 5,15-bis(pentafluorophenyl)-10-(4)-(1-pyrenyl)phenyl corrole that contains a triphenylphosphine axial ligand (1-PPh3 ) was synthesized and examined as an electrocatalyst for the hydrogen evolution reaction (HER). If supported on graphene (G), the resulting 1-PPh3 /G material can catalyze the HER in aqueous solutions over a wide pH range of 0-14 with a high efficiency and durability. The significantly enhanced activity of 1-PPh3 /G, compared with that of its analogues 1-py/G (the Co-bound axial ligand is pyridine instead of triphenylphosphine) and 2-py/G (Co complex of 5,10,15-tris(pentafluorophenyl)corrole), highlights the effects of the pyrenyl substituent and the triphenylphosphine axial ligand on the HER activity. On one hand, the pyrenyl moiety can increase the π-π interactions between 1 and graphene and thus lead to a fast electron transfer from the electrode to 1. On the other hand, the triphenylphosphine axial ligand can increase the electron density (basicity) of Co and thus make the metal center more reactive to protons at the trans position through a so-called "push effect". This study concerns a significant example that shows the trans effect of the axial ligand on the HER, which has been investigated rarely. The combination of various ligand-design strategies in one molecule has been realized in 1-PPh3 to achieve a high catalytic HER performance. These factors are valuable to be used in other molecular catalyst systems.