Search

The micro-volume analysis and specific detection are both essential requirements in the field of chemical sensing and biological testing. Membrane prefiltration can be used to improve the selectivity and accuracy of detection. But for traditional porous membrane filtration, it is difficult to achieve the transmembrane transport of micro-volume liquid due to the influence of lateral diffusion on membrane surface. Herein, we studied the focused transmembrane transport of micro-volume liquid in the porous polyethersulfone membrane with asymmetric (Janus) surface wettability. The hydrophilic layer (polydopamine) and hydrophobic layer (fluoropolymer) were deposited with controllable thickness by dip-coating and roller-assisted liquid printing. The micro-volume liquid focusing effect was verified by experiments such as visual wetting circle and fluorescent tracer. The liquid focusing effect of as-prepared Janus membrane was integrated with glucose test strip in the application of micro-volume liquid biosensing. Compared with conventional porous membrane, detected signal amplitude and response time were improved 7.5× and 2.7×, respectively. In summary, this research studied the dynamics of liquid transport through Janus membrane and provides a new strategy for microfluidic detection applications through balancing detection volume, time and selectivity by the advantage of micro-volume liquid focusing effect.

Photochemical smog characterized by high concentrations of ozone (O3) is a serious air pollution issue in the North China Plain (NCP) region, especially in summer and autumn. For this study, measurements of O3, nitrogen oxides (NOx), volatile organic compounds (VOCs), carbon monoxide (CO), nitrous acid (HONO), and a number of key physical parameters were taken at a suburban site, Xianghe, in the NCP region during the summer of 2018 in order to better understand the photochemical processes leading to O3 formation and find an optimal way to control O3 pollution. Here, the radical chemistry and O3 photochemical budget based on measurement data from 1−23 July using a chemical box model is investigated. The daytime (0600−1800 LST) average production rate of the primary radicals referred to as ROx (OH + HO2 + RO2) is 3.9 ppbv h−1. HONO photolysis is the largest primary ROx source (41%). Reaction of NO2 + OH is the largest contributor to radical termination (41%), followed by reactions of RO2 + NO2 (26%). The average diurnal maximum O3 production and loss rates are 32.9 ppbv h−1 and 4.3 ppbv h−1, respectively. Sensitivity tests without the HONO constraint lead to decreases in daytime average primary ROx production by 55% and O3 photochemical production by 42%, highlighting the importance of accurate HONO measurements when quantifying the ROx budget and O3 photochemical production. Considering heterogeneous reactions of trace gases and radicals on aerosols, aerosol uptake of HO2 contributes 11% to ROx sink, and the daytime average O3 photochemical production decreases by 14%. The O3-NOx-VOCs sensitivity shows that the O3 production at Xianghe during the investigation period is mainly controlled by VOCs.

Chlorine dioxide (ClO2), an alternative disinfectant to chlorine, has been widely applied in water and wastewater disinfection. This paper aims at presenting an overview of the inactivation kinetics and mechanisms of ClO2 with viruses. The inactivation efficiencies vary greatly among different virus species. The inactivation rates for different serotypes within a family of viruses can differ by over 284%. Generally, to achieve a 4-log removal, the exposure doses, also being referred to as Ct values (mutiplying the concentration of ClO2 and contact time) vary in the range of 0.06–10 mg L−1 min. Inactivation kinetics of viruses show two phases: an initial rapid inactivation phase followed by a tailing phase. Inactivation rates of viruses increase as pH or temperature increases, but show different trends with increasing concentrations of dissolved organic matter (DOM). Both damages in viral proteins and in the 5′ noncoding region within the genome contribute to virus inactivation upon ClO2 disinfection. Supplementary Information The online version contains supplementary material available at 10.1007/s00128-021-03137-3.

Chlorine radicals, including Cl• and Cl2•-, can be produced in sunlight waters (rivers, oceans, and lakes) or water treatment processes (e.g., electrochemical and advanced oxidation processes). Dissolved organic matter (DOM) is a major reactant with, or a scavenger of, Cl• and Cl2•- in water, but limited quantitative information exists regarding the influence of DOM structure on its reactivity with Cl• and Cl2•-. This study aimed at quantifying the reaction rates and the formation of chlorinated organic byproducts produced from Cl• and Cl2•- reactions with DOM. Laser flash photolysis experiments were conducted to quantify the second-order reaction rate constants of 19 DOM isolates with Cl• (kDOM-Cl•) and Cl2•- (kDOM-Cl2•-), and compare those with the hydroxyl radical rate constants (kDOM-•OH). The values for kDOM-Cl• ((3.71 ± 0.34) × 108 to (1.52 ± 1.56) × 109 MC-1 s-1) were orders of magnitude greater than the kDOM-Cl2•- values ((4.60 ± 0.90) × 106 to (3.57 ± 0.53) × 107 MC-1 s-1). kDOM-Cl• negatively correlated with the weight-averaged molecular weight (MW) due to the diffusion-controlled reactions. DOM with high aromaticity and total antioxidant capacity tended to react faster with Cl2•-. During the same experiments, we also monitored the formation of chlorinated byproducts through the evolution of total organic chlorine (TOCl) as a function of chlorine radical oxidant exposure (CT value). Maximum TOCl occurred at a CT of 4-8 × 10-12 M·s for Cl• and 1.1-2.2 × 10-10 M·s for Cl2•-. These results signify the importance of DOM in scavenging chlorine radicals and the potential risks of producing chlorinated byproducts of unknown toxicity.

Materials with specific wettability properties have aroused enormous interest and research for their broad application prospects in chemical reaction, medical diagnosis, biological analysis, etc. Here, inspired by the unique Janus wettability of lotus leaf and Bragg stacks of beetles, we present a free-standing film with Janus wettability and tunable structural color for water quality monitoring. This film is constructed by using a flexible polymer polyurethane (PU) to pack poly(

Designing high-efficiency and low-cost bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of great significance to produce hydrogen by water electrolysis. Herein, a hierarchical FeCo2S4@CoFe layered double hydroxide (LDH) core–shell structure catalyst was successfully fabricated via a hydrothermal–sulfuration–electrodeposition three-step method. The unique structure can provide more abundant catalytically active sites for the electrochemical reaction. The resulting FeCo2S4@CoFe LDH electrode only requires overpotentials of 115 and 247 mV to reach a current density of 10 mA cm−2 for the HER and OER in 1 M KOH electrolyte, respectively. The electrode also exhibits a low Tafel slope and excellent stability. Furthermore, the bifunctional catalyst for overall water splitting can exhibit a cell voltage of 1.6 V at 10 mA cm−2, along with outstanding durability for 24 h testing. This work provides a new strategy to design effective bifunctional catalysts for overall water splitting.

A detailed analysis of the electrical response of In0.3Ga0.7As surface quantum dots (SQDs) coupled to 5-layer buried quantum dots (BQDs) is carried out as a function of ethanol and acetone concentration while temperature-dependent photoluminescence (PL) spectra are also analyzed. The coupling structure is grown by solid source molecular beam epitaxy. Carrier transport from BQDs to SQDs is confirmed by the temperature-dependent PL spectra. The importance of the surface states for the sensing application is once more highlighted. The results show that not only the exposure to the target gas but also the illumination affect the electrical response of the coupling sample strongly. In the ethanol atmosphere and under the illumination, the sheet resistance of the coupling structure decays by 50% while it remains nearly constant for the reference structure with only the 5-layer BQDs but not the SQDs. The strong dependence of the electrical response on the gas concentration makes SQDs very suitable for the development of integrated micrometer-sized gas sensor devices.

A reduction in the use of aluminum (Al)-based flocculants in the treatment of drinking water is considered essential for human health reasons. In this study, a novel composite flocculant, made of carboxymethylpullulan-AlCl3 , is evaluated in a lab-scale, jar test system for the flocculation of kaolin. The results showed that the coagulation efficiency of carboxymethylpullulan-AlCl3 was more effective in reducing turbidity than the solo use of carboxymethylpullulan or AlCl3 . The optimum treatment conditions assessed by a response surface methodology were obtained at pH 6.50, 13.03 mg/L carboxymethylpullulan, and 94.87 mg/L AlCl3 . Zeta potential measurements and photometric dispersion analysis demonstrated that AlCl3 had a more significant influence on charge neutralization than carboxymethylpullulan, whilst carboxymethylpullulan facilitated absorption and the development of particle bridges. Thus, the composite flocculant possessed both advantages that enhanced flocculation, and decreased the dosage of AlCl3 , thereby reducing the potential for secondary environment pollution. When 90 mg/L carboxymethylpullulan-AlCl3 was added to the model kaolin suspension characterized by a turbidity of 50 nephelometric turbidity units, the zeta potential and the maximum flocculating activity were determined as -2.28 mV and 98.0%, respectively. The results provide insight into the development of an environment-friendly composite flocculant prepared from water-dissolved polysaccharide and inorganic flocculants. PRACTITIONER POINTS: A novel composite flocculant CMP-AlCl3 was achieved by combining CMP and AlCl3 for water treatment. The coagulation efficiency of CMP-AlCl3 was more effective in reducing turbidity than the solo use of CMP or AlCl3 . The flocculation efficiency and mechanism were investigated by Zeta potential analysis, surface morphology, electron microscopy, and coagulation.

The design of electrode materials with rational core/shell structures is promising for improving the electrochemical properties of supercapacitors. Hence, hierarchical FeCo2 S4 @FeNi2 S4 core/shell nanostructures on Ni foam were fabricated by a simple hydrothermal method. Owing to their structure and synergistic effect, they deliver an excellent specific capacitance of 2393 F g-1 at 1 A g-1 and long cycle lifespan as positive electrode materials. An asymmetric supercapacitor device with FeCo2 S4 @FeNi2 S4 as positive electrode and graphene as negative electrode exhibited a specific capacitance of 133.2 F g-1 at 1 A g-1 and a high energy density of 47.37 W h kg-1 at a power density of 800 W kg-1 . Moreover, the device showed remarkable cycling stability with 87.0 % specific-capacitance retention after 5000 cycles at 2 A g-1 . These results demonstrate that the hierarchical FeCo2 S4 @FeNi2 S4 core/shell structures have great potential in the field of electrochemical energy storage.

We report a comparative study of the binding of I2 (iodine) in a pair of redox-active metal–organic framework (MOF) materials, MFM-300(VIII) and its oxidized, deprotonated analogue, MFM-300(VIV). Adsorption of I2 in MFM-300(VIII) triggers a host-to-guest charge-transfer, accompanied by a partial (∼30%) oxidation of the VIII centers in the host framework and formation of I3– species residing in the MOF channels. Importantly, this charge-transfer induces a significant enhancement in the electrical conductivity (Δσ = 700000) of I2@MFM-300(VIII/IV) in comparison to MFM-300(VIII). In contrast, no host–guest charge-transfer or apparent change in the conductivity was observed upon adsorption of I2 in MFM-300(VIV). High-resolution synchrotron X-ray diffraction of I2@MFM-300(VIII/IV) confirms the first example of self-aggregation of adsorbed iodine species (I2 and I3–) into infinite helical chains within a MOF., Adsorption of I2 in MFM-300(VIII) induces host-to-guest charge-transfer, resulting in the formation of a mixed-valence material I2@MFM-300(VIII/IV), which shows a significant enhancement in the electrical conductivity (Δσ = 700000) in comparison with MFM-300(VIII).

Microcystin-LR (MC-LR) generated by cyanobacteria is a potent toxin threatening human health. In this study the kinetics and mechanisms of MC-LR elimination from drinking water under solar irradiation with free chlorine (the solar/chlorine process) was evaluated. The rate of MC-LR degradation was dramatically enhanced in the solar/chlorine process (1.1 × 10−2 s−1) compared with chlorination alone (2.6 × 10−3 s−1) or solar irradiation alone (1.2 × 10−4 s−1) with a free chlorine dose of 42 μM (3.0 mg L−1 as Cl2). The enhancement was due to the presence of hydroxyl radicals, reactive chlorine species (RCS), and ozone during free chlorine photolysis. The second-order rate constants of Cl • and Cl2•- reacting with MC-LR were determined to be (2.25 ± 0.07) × 1010 and (5.58 ± 0.42) × 107 M−1s−1, respectively. Cl • was the major RCS contributing to MC-LR elimination. The highest MC-LR degradation rate was observed at pH 8.0. Free chlorine, HO •, Cl • and O3 together accounted for almost 95% of the MC-LR elimination. Hydroxyl- and chloro-MC-LR were generated in the process, followed by dechlorination, dehydration and cleavage of cyclic structures in MC-LR. Aldehyde- and ketone-MC-LR byproducts were also observed. The destruction of dienes led to a great reduction in MC-LR's toxicity. MC-LR removal in natural water samples under natural sunlight irradiation with free chlorine was demonstrated with limited formation of disinfection byproducts. The solar/chlorine process is an energy-efficient approach for MC-LR control, especially suitable for rural areas or where algal blooming threatens.

Iodine detection is crucial for nuclear waste clean-up and first responder activities. For ease of use and durability of response, robust active materials that enable the direct electrical detection of I2 are needed. Herein, a large reversible electrical response is demonstrated as I2 is controllably and repeatedly adsorbed and desorbed from a series of metal–organic frameworks (MOFs) MFM-300(X), each possessing a different metal center (X = Al, Fe, In, or Sc) bridged by biphenyl-3,3′,5,5′-tetracarboxylate linkers. Impedance spectroscopy is used to evaluate how the different metal centers influence the electrical response upon cycling of I2 gas, ranging from 10× to 106× decrease in resistance upon I2 adsorption in air. This large variation in electrical response is attributed not only to the differing structural characteristics of the MOFs but also to the differing MOF morphologies and how this influences the degree of reversibility of I2 adsorption. Interestingly, MFM-300(Al) and MFM-300(In) displayed the largest changes in resistance (up to 106×) yet lost much of their adsorption capacity after five I2 adsorption cycles in air. On the other hand, MFM-300(Fe) and MFM-300(Sc) revealed more moderate changes in resistance (10–100×), maintaining most of their original adsorption capacity after five cycles. This work demonstrates how changes in MOFs can profoundly affect the magnitude and reversibility of the electrical response of sensor materials. Tuning both the intrinsic (resistivity and adsorption capacity) and extrinsic (surface area and particle morphology) properties is necessary to develop highly reversible, large signal-generating MOF materials for direct electrical readout for I2 sensing.

A novel photoelectrochemical (PEC) biosensor based on hybrids of NaYF4:Yb, Tm, zinc oxide (ZnO) and cadmium sulfide (CdS) was constructed to detect alpha-fetoprotein (AFP), which possesses the advantages of low background noise and non-damage to the biological substance. Herein, we prepared NaYF4:Yb,Tm/ZnO/CdS composite film electrode by pulsed laser deposition. The selected materials of ZnO and CdS can make full use of the upconversion luminescence (˜360 nm, ˜480 nm) of NaYF4:Yb,Tm nanophosphors under 980 nm laser excitation. Meanwhile, an effective matching of energy levels between the conduction bands of CdS and ZnO can prompt photoelectrochemical performance of the electrode. The biosensor shows ultrasensitive detection of AFP with a wide linear range from 0.01 ng mL−1 to 200 ng mL−1 and a low detection limit of 5 pg mL−1. Therefore, the proposed PEC biosensor based on upconversion nanophosphors is potentially attractive for achieving excellent photoelectrochemical biosensor for detection of other cancer markers in clinical analysis.

This work addresses the massive multiple input multiple output (MIMO) beamforming scheduling problem. The scheduling model for packet transmission with paralleled caches using massive MIMO multicast beamforming is proposed by using reinforcement learning (RL) theory to denote the mapping function from the system state to the beamforming strategy. The delay-aware model-free RL scheduling problem for massive MIMO multicast beamforming is derived and analyzed in asymptotic condition. We show that the model-free RL method can be a complementary way to optimize the packet delay when the channel state information (CSI) is unavailable and the traditional convex optimization based methods are consequently ineffective. To derive low-complexity algorithm, we build the RL sub-problems for each specific multicast group which are asymptotically independent. The policy gradient method is used to solve the proposed RL problems. In numerical experiments we provide simulation results under different number of transmitting antennas and provide performance comparison between the proposed method and randomized method. It shows that even without using CSI, the RL based policy can still dynamically optimize the delay of the system and out-perform the randomized policy.

Surface modifications play an important role in endowing implant surface with excellent biocompatibility and bioactivity. Among the bioinspired surface modifications, the mussel-inspired polydopamine (PDA) has aroused great interest of researchers. Herein, we fabricated PDA on diverse implant surfaces, including biopolymer, biometal, and bioceramic. Then the effects of PDA coating on cell responsive behaviors in vitro and bone formation capacity in vivo were evaluated in detail. The results showed that PDA coating was fabricated on diverse samples surface successfully, which could significantly improve the hydrophilicity of different material surfaces. Furthermore, the results indicated that PDA coating exerted direct enhancing on the adhesion, proliferation and osteogenic differentiation of bone marrow derived mesenchymal stromal cells (BMSCs) through FAK and p38 signaling pathways. During the process, the focal adhesion protein expression and osteogenic-related genes expression level (e.g., ALP, BMP2, BSP, and OPN) were considerably upregulated. Most importantly, the in vivo study confirmed that PDA coating remarkably accelerated new bone formation and enhanced osseointegration performance. Our study uncovered the biological responses stimulated by PDA coating to make a better understanding of cell/tissue-PDA interactions and affirmed that PDA, a bioinspired polymer, has great potential as a candidate and functional bioactive coating medium in bone regeneration and orthopedic application.

Microcystin-LR (MC-LR), a toxin produced by cyanobacteria, is very toxic and poses a threat to public health when entering water treatment works. In this study, UV/chlorine process, as an advanced oxidation process (AOP), has been demonstrated for effective elimination of MC-LR levels and associated toxicity. At a chlorine dose of 3.0 mg L−1 and UV fluence of 125 mJ cm−2, MC-LR (initial concentration 1.0 μM) was reduced by 92.5%, which was much higher than 20.3% removal under UV irradiation alone and 65.1% removal during dark chlorination. Enhanced degradation was attributed by hydroxyl radicals (HO ) and reactive chlorine species (RCS), mainly Cl2 - and ClO . Increasing chlorine doses or lowering pH favored MC-LR removal. Increased bicarbonate and natural organic matter concentrations inhibited MC-LR removal, but bromide ions enhanced MC-LR removal instead. MC-LR elimination rates in natural waters were roughly two times smaller than those in ultrapure water. The reactive radicals promoted hydroxylation of both diene of Adda moiety and double bond of Mdha moiety in MC-LR. UV exposure enhanced the dechlorination of chloro-MC-LR via the cleavage of C Cl bond. The toxicity was evaluated by a protein phosphatase (PP2A) inhibition assay. At a chlorine dose of 3.0 mg L−1 and UV fluence of 125 mJ cm−2, the toxicity of the treated water was reduced by 75.0%, which was also higher than 25.7% and 46.7% removal under UV irradiation alone and during dark chlorination, respectively. These results highlight UV/chlorine is an efficient AOP for MC-LR degradation and detoxification.

Bone implants play a crucial role in bone repairing. Nevertheless, low capability of osteoinductivity and osteogenic differentiation for bone regeneration are disadvantages of bone implants. Therefore, it is imperative to develop a general and facile technology to promote the bioactivity of existing implants. Herein, a facile amorphous carbon-coating approach was developed to stimulate osteogenesis on diverse biomaterials, including bioceramics, biometals, and biopolymers via magnetron sputtering deposition. The results confirmed that the amorphous carbon-coating-modified surfaces could significantly enhance osteogenesis of bone marrow mesenchymal stem cells (BMSCs) on every kind of biomaterial surface. Furthermore, it was demonstrated that the FAK/ERK1/2 signaling pathways were involved in the osteogenic effects of this amorphous carbon coating. The bone regeneration ability using the calvarial bone defect model of rats confirmed that the amorphous carbon coating induced faster bone formation and mineralization, which suggested the effect of amorphous carbon coating on stimulating osteogenesis in vivo. These results suggest that the approach involving modifying a surface with amorphous carbon provides a general and simple strategy to enhance the osteogenesis for diverse biomaterials, and this has promising potential for bone repairing applications.

Modified metal–organic frameworks (MOFs) doping with enzymes exhibit high enzyme stability and catalytic performance, which is a research hotspot in the field of enzyme-based sensing. Although the MOF-enzyme constitutes a 3D structure in the nanoscale, the macroscopic assembly configuration still stays in 1D or 2D structures, limiting sensing applications towards complex biological targets. Herein, the MOF-enzyme hybrid nanosystem was assembled into 3D porous conductive supports via a controllable physical embedding method, displaying high enzymatic loading, stability and cascade catalytic performance. The modified MOFs combing with enzymes served as a sensing reaction system, and the conductive hollow fiber membranes (HFMs) served as a functional platform. The multifunctional device integrates pumpless hydrodynamic transport, interconnected conductive polymer, and blood separation modules, showing fast capillary fluid flow, trace sampling (3 μL), high selectivity and accuracy. The linear sensing range was in 2–24 mM glucose, 0.05–6 mM lactic acid, and 0.1–10 mM cholesterol, respectively, with sensitivities of 24.2, 150, 73.6 nA mM−1. Furthermore, this strategy of modular assembly of biosensing array can easily implement multiplex metabolites detection simultaneously.

We report a low-cost, highly energy efficient microwave-assisted chelation (MWAC) method, which enabled the post-synthetic modification of synthetic zeolites for adopting hierarchical structures within minutes. Exemplified by Zeolite Y, hierarchical Y zeolites prepared in this way showed exceptional specific external surface areas of >300 m2 g−1 and mesopore volumes of >0.46 cm3 g−1. Comparative assessments revealed that developed zeolites have shown significantly improved catalytic activities for catalysis involving large substrates, such as catalytic cracking and hydrocracking of plastics.

Structural transitions of host systems in response to guest binding dominate many chemical processes. We report an unprecedented type of structural flexibility within a meta-rigid material, MFM-520, which exhibits a reversible periodic-to-aperiodic structural transition resulting from a drastic distortion of a [ZnO4N] node controlled by the specific host-guest interactions. The aperiodic crystal structure of MFM-520 has no three-dimensional (3D) lattice periodicity but shows translational symmetry in higher-dimensional (3 + 2)D space. We have directly visualized the aperiodic state which is induced by incommensurate modulation of the periodic framework of MFM-520·H2O upon dehydration to give MFM-520. Filling MFM-520 with CO2 and SO2 reveals that, while CO2 has a minimal structural influence, SO2 can further modulate the structure incommensurately. MFM-520 shows exceptional selectivity for SO2 under flue-gas desulfurization conditions, and the facile release of captured SO2 from MFM-520 enabled the conversion to valuable sulfonamide products. MFM-520 can thus be used as a highly efficient capture and delivery system for SO2.

Numerous precipitation methods for creating nanoparticle dispersions that are based on mixing a solution with a miscible nonsolvent have been developed. Here, we show that for polymer particles, the formation is highly dependent on the rate of mixing. We also demonstrate the importance of the glass transition of the polymers on particle formation. A simple model of droplet formation during mixing provides a satisfactory description of the observed dependence of particle size on polymer molecular weight, concentration, solvent ratio, and mixing conditions.

Inorganic-enzyme composites have been widely used for applications in catalysis and analytical science. Amorphous calcium phosphate, as a biocompatible material, can form open hydrated structure to encapsulate and protect enzymes. So far, there have been few progress on size-adjustable amorphous calcium phosphate nanoparticles since the diameter controllability is limited by its natural aggregation characteristics. By co-precipitation and nano-channel extrusion, we developed enzyme-loaded amorphous calcium phosphate nanoparticles with adjustable diameters. These enzyme-loaded particles showed high thermal and chemical stability as well as biocompatibility. The nano-sized enzyme-loaded particles can further expand their application fields and be used as intracellular enzyme probes. Delivering glucose oxidase enzyme by amorphous calcium phosphate nanoparticles enables fluorescent monitoring of glucose levels in living cells, which can be used to study the metabolism rates of cancer cells and normal cells. The nano-channel extrusion method can also be used as a template to encapsulate different kinds of enzymes to expand catalysis and biosensing applications.

Nitrous Acid (HONO) is an important precursor of hydroxyl radical (OH) and has significant impacts on the formation of Ozone (O3) and Secondary Organic Aerosol (SOA). The atmospheric concentrations of HONO were measured during early autumn in downtown, Beijing (China). This study investigated HONO pollution characteristics and potential sources during day and night. The maximum hourly HONO levels reached 5.16 ppb, with 1.23 ppb on average. HONO concentration exhibited typical diurnal variation characteristics, with maximum at nighttime and minimum at daytime. The potential sources mainly included vehicle emission, heterogeneous reaction of NO2 on aerosol surfaces (Photo-enhanced at the daytime) and photolysis of particulate nitrate (NO3−) in Beijing. Vehicle emission was an important HONO source, particular at the morning rush period and lower HONO concentration. The simulated results highlighted that the main contribution of HONO was NO2 heterogeneous reaction on aerosol surfaces. The photolysis of particulate NO3− was also an important daytime HONO source, particularly in the pollution period. The main loss routine was the photolysis of HONO and dry deposition at day and night, respectively.

Injectable bioactive ceramics with excellent osteogenesis play important roles in bone regeneration field. In this study, we creatively fabricated the injectable nano-structured silicon-containing hydroxyapatite (Si-HAp) microspheres in diameter of 70–100 µm via hydrothermal treatment of calcium silicate (CaSiO3) microspheres in Na3PO4 aqueous solution. The fabricated Si-HAp microspheres were constructed by nano-rods with a diameter of 100 nm and length up to 1.5 µm. Comparing with the pure HAp microspheres, the obtained nano-structured Si-HAp microspheres exhibited excellent protein loading properties and sustained protein release capacities. Most importantly, the Si-substitution could apparently enhance the proliferation, osteogenic differentiation and the genes expression of angiogenic factors of rat bone marrow mesenchymal stem cells (rBMSCs). These all indicated that the nano-structured Si-HAp microspheres fabricated via hydrothermal transformation method might be used as promising injectable bioactive biomaterials and drug deliveries for bone regeneration.

Electrospinning is an effective way to fabricate ultralong nanotubes with a large surface area. However, the nanotubes synthesized through this way suffer from difficult controlling of structural parameters. A facile strategy for constructing highly controllable Pt@ZnO nanoparticles (NPs) drive TiO2 nanotubes (NTs) (Pt@ZnO-TiO2 NTs) was developed in this work. First, the polystyrene electrospun nanofibers (∼490 nm) containing Pt@zeolitic imidazolate framework-8 (ZIF-8) was fabricated as a self-sacrificial template and then was decorated by a thinner tetrabutyl orthotitanate layer through soaking. After annealing, the Pt@ZnO NPs were obtained due to the decomposition of Pt@ZIF-8 during calcination. The involving of ZIF-8 can effectively prevent the aggregation of Pt during heat treatment (∼3 nm, monodispersed), and thus highly improves its catalyst property. When Pt@ZnO-TiO2 NTs were evaluated as a sensing material for toluene detection, the obtained sensors exhibited an enhanced sensing response (11.1 to 1 ppm toluene), faster response/recovery times (7.5 and 20.1 s) and a lower detection limit (23 parts per billion) during dynamic measurement, when compared to the pristine TiO2 and directly mixed Pt-TiO2 NTs. This was mainly attributed to the improved oxygen vacancy concentration in the NT composite and resistance modulation effect induced by the unique NT structure, as well as the well-dispersed and small-sized Pt catalyst.

Emissions of SO2 from flue gas and marine transport have detrimental impacts on the environment and human health, but SO2 is also an important industrial feedstock if it can be recovered, stored and transported efficiently. Here we report the exceptional adsorption and separation of SO2 in a porous material, [Cu2(L)] (H4L = 4′,4‴-(pyridine-3,5-diyl)bis([1,1′-biphenyl]-3,5-dicarboxylic acid)), MFM-170. MFM-170 exhibits fully reversible SO2 uptake of 17.5 mmol g−1 at 298 K and 1.0 bar, and the SO2 binding domains for trapped molecules within MFM-170 have been determined. We report the reversible coordination of SO2 to open Cu(ii) sites, which contributes to excellent adsorption thermodynamics and selectivities for SO2 binding and facile regeneration of MFM-170 after desorption. MFM-170 is stable to water, acid and base and shows great promise for the dynamic separation of SO2 from simulated flue gas mixtures, as confirmed by breakthrough experiments.

UV–vis differential spectroscopy was applied to characterize and quantify the spectral changes after ClO2 oxidation of ten humic substances, seven aromatic model compounds and four surface waters. The differential spectra of ten humic substances after ClO2 oxidation all exhibited a peak near 230 nm and a broad absorbance band with a maximum at around 316 nm. The differential spectra after ClO2 oxidation were distinguished from the one after chlorination, which was indicative of their different oxidation mechanisms. The differential spectra after ClO2 treatment were well fitted by seven Gaussian bands with maxima at about 200, 225, 240, 276, 316, 385 and 457 nm. Differential absorbance at 316 nm and 400 nm (denoted as DA316 and DA400, respectively) were found to best quantify the degradation of organic matters during ClO2 oxidation with negligible interferences from water matrixes. Oxidation of substituted functional groups on aromatic structures, rather than destruction of aromatic rings, was more responsible for chlorite formation. Spectral parameters–DA316 and DA400 showed strong correlations with ClO2 consumption and chlorite formation during ClO2 oxidation of humic substances and surface water samples. The results demonstrate that DA316 and DA400 can serve as promising indicators of chlorite formation and ClO2 consumption, which provide a practical approach for online water quality monitoring during ClO2 water purification.

Recent demonstration of mobilities in excess of 10 cm2 V–1 s–1 have energized research in solution deposition of polymers for thin film transistor applications. Due to the lamella motif of most soluble, semiconducting polymers, the local mobility is intrinsically anisotropic. Therefore, fabrication of aligned films is of interest for optimization of device performance. Many techniques have been developed to control film alignment, including solution deposition via directed flows and deposition on topologically structured substrates. We report device and detailed structural analysis (ultraviolet–visible absorption, IR absorption, near-edge X-ray absorption (NEXAFS), grazing incidence X-ray diffraction, and atomic force microscopy) results from blade coating two high performing semiconducting polymers on unpatterned and nanostructured substrates. Blade coating exhibits two distinct operational regimes: the Landau–Levich or horizontal dip coating regime and the evaporative regime. We find that in the evapora...

This study investigated the role of bromide ions in the degradation of nine pharmaceuticals and personal care products (PPCPs) during the UV/chlorine treatment of simulated drinking water containing 2.5 mgC L−1 natural organic matter (NOM). The kinetics of contributions from UV irradiation and from oxidation by free chlorine, free bromine, hydroxyl radical and reactive halogen species were evaluated. The observed loss rate constants of PPCPs in the presence of 10 μM bromide were 1.6–23 times of those observed in the absence of bromide (except for iopromide and ibuprofen). Bromide was shown to play multiple roles in PPCP degradation. It reacts rapidly with free chlorine to produce a trace amount of free bromine, which then contributes to up to 55% of the degradation of some PPCPs during 15 min of UV/chlorine treatment. Bromide was also shown to reduce the level of HO• and to change the reactive chlorine species to bromine-containing species, which resulted in decreases in ibuprofen degradation and enhancem...

Three-dimensional ordered macroporous iridium oxides (3DOM IrO x 0 ≤ x ≤ 2), were synthesized through a simple self–assembly template method and developed as an electrode material for lable–free immunosensor of cancer biomarker alpha-fetoprotein (AFP). The 3DOM IrO x was well modified on flexible fluorine-doped tin oxide (FTO) electrode and such FTO electrodes based 3DOM IrO x immnuosensor enhanced the adsorption of electrolytes, the diffusion of reactants, and also could act as a rapid electron transfer channel benefited both from the advantage of 3DOM architecture and the nature of IrO x itself. These combined characteristics greatly increased the sensitivity, shortened the response time, reduced the interference, promoted the stability and moreover, demonstrated good accuracy to detect AFP in human serum. The optimum structure and sensing properties of immnuosensor were obtained based on 3DOM IrO x annealed at 500 °C. It allows detecting AFP over a wide concentration range from 1 to 250 ng/mL with a detection limit of 0.3 ng/mL, and a higher slope of the calibration equation. The manufactured immunosensor was also used to determine AFP in human serum with satisfactory results. This kind of 3DOM IrO x modified and FTO-based immunosensor has great application potential for the AFP electrochemical detection.

Brain tumor delineation and treatment are the main concerns of neurosurgeons in neurosurgical operations. Bridging the gap between imaging/diagnosis and treatment will provide great convenience for neurosurgeons. Here, we developed an optical theranostics platform that helps to delineate the boundary and quantitatively analyze glioblastoma multiforms (GBMs) with bioluminescence imaging (BLI) to guide laser ablation, and we imaged the GBM cells with two-photon microscopy (TPM) to visualize the laser ablation zone in vivo. Methods: Laser ablation, using the method of coupled ablated path planning with the guidance of BLI, was implemented in vivo for mouse brain tumors. The mapping relationship between semi-quantitative BLI and the laser ablation path was built through the quantitative tumor burden. The mapping was reflected through coupled ablated path planning. The BLI quantitatively and qualitatively evaluated treatment using laser ablation with the appropriate laser parameters and laser-tissue parameters. These parameters were measured after treatment. Furthermore, histopathological analysis of the brain tissue was conducted to compare the TPM images before and after laser ablation and to evaluate the results of in vivo laser ablation. The local recurrences were measured with three separate cohorts. The weights of all of the mice were measured during the experiment. Results: Our in vivo BLI data show that the tumor cell numbers were significantly attenuated after treatment with the optical theranostics platform, and the delineation of GBM margins had clear views to guide the laser resection; the fluorescence intensity in vivo of GBMs quantitatively analyzed the rapid progression of GBMs. The laser-tissue parameters under guidance of multimodality imaging ranged between 1.0 mm and 0.1 mm. The accuracy of the laser ablation reached a submillimeter level, and the resection ratio reached more than 99% under the guidance of BLI. The histopathological sections were compared to TPM images, and the results demonstrated that these images highly coincided. The weight index and local recurrence results demonstrated that the therapeutic effect of the optical theranostics platform was significant. Conclusion: We propose an optical multimodality imaging-guided laser ablation theranostics platform for the treatment of GBMs in an intravital mouse model. The experimental results demonstrated that the integration of multimodality imaging can precisely guide laser ablation for the treatment of GBMs. This preclinical research provides a possibility for the precision treatment of GBMs. The study also provides some theoretical support for clinical research.

Both the topographic surface and chemical composition modification can enhance rapid osteogenic differentiation and bone formation. Till now, the synergetic effects of topography and chemistry cues guiding biological responses have been rarely reported. Herein, the ordered micro-patterned topography and classically essential trace element of strontium (Sr) ion doping were selected to imitate topography and chemistry cues, respectively. The ordered micro-patterned topography on Sr ion-doped bioceramics was successfully duplicated using the nylon sieve as the template. Biological response results revealed that the micro-patterned topography design or Sr doping could promote cell attachment, ALP activity, and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Most importantly, the samples both with micro-patterned topography and Sr doping showed the highest promotion effects, and could synergistically activate the ERK1/2 and p38 MAPK signaling pathways. The results suggested that the grafts with both specific topography and chemistry cues have synergetic effects on osteogenic activity of BMSCs and provide an effective approach to design functional bone grafts and cell culture substrates.

Highly uniform and compositionally graded Pd–Zn nanocrystals (NCs) with particle diameters of approximately 5.0–6.5 nm are obtained via a facile one-pot synthesis process in dimethylformamide (DMF) and water solution. The Pd–Zn NCs are formed by the reduction of transition metal ions coexisting in ascorbic acid (AA) and noble metals. The NCs are characterized by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. Investigations indicated that the NCs have compositionally graded PdxZn1−x NCs with x ranging from 0.68 to 1.00. Electrochemical measurements reveal that the PdxZn1−x NCs exhibit superior electrocatalytic performance of both activity and stability for the formic acid oxidation (FAO) reaction compared with commercial Pd/C. The optimized Pd0.77Zn0.23 NCs exhibit a FAO catalytic oxidation current density of 1945 mA mgPd−1, which is 8.2 times higher than that of commercial Pd/C (237 mA mgPd−1). CO stripping measurement indicates that the tolerance to CO poisoning has been significantly improved by alloying Zn. The excellent performance can be attributed to the synergistic effect between Pd and Zn in Pd–Zn NCs.

Fixed-pattern noise seriously affects the clinical application of optical coherence tomography (OCT), especially, in the imaging of tumorous tissue. We propose a Hough transform-based fixed-pattern noise reduction (HTFPNR) method to reduce the fixed-pattern noise for optimizing imaging of tumorous tissue with OCT system. Using by the HTFPNR method, we detect and map the outline of fixed-pattern noise in the OCT images, and finally efficiently reduce the fixed-pattern noise by the longitudinal and horizontal intelligent processing procedure. We adopt the image-to-noise ratio with full information (INRfi) and the noise reduction ratio (NRR) to evaluate the outcome of fixed-pattern noise reduction ratio, respectively. The INRfi of OCT image's noise reduction of ex vivo brainstem tumor is approximate 21.92 dB. Six groups of OCT images, including three types of fixed-pattern noises, have been validated via experimental evaluation of the ex vivo gastric tumor. In the different types of fixed-pattern noise, the mean INRfis are 25.24, 23.04, and 19.35 dB, respectively. This result demonstrates that it is highly efficient and useful in fixed-pattern noise reduction. The fluctuating range of the NRR is 0.84-0.88 for three types of added noise in the OCT images. This result demonstrates that the HTFPNR method can as possible as save useful information by comparing to previous research. This proposed HTFPNR method can be used into the fixed-pattern noise reduction of OCT images in other soft biological tissue in the future.

Photolysis of ClO2 by UVC radiation occurs in several drinking water treatment scenarios (e.g., pre-oxidation by ClO2 with post-UVC disinfection or a multi-barrier disinfection system comprising ClO2 and UVC disinfection in sequence). However, whether micropollutants are degraded and undesired byproducts are formed during the co-exposure of ClO2 and UVC radiation remain unclear. This study demonstrated that four micropollutants (trimethoprim, iopromide, caffeine, and ciprofloxacin) were degraded by 14.4–100.0% during the co-exposure of ClO2 and UVC radiation in the synthetic drinking water under the environmentally relevant conditions (UV dose of 207 mJ cm−2, ClO2 dose of 1.35 mg L−1, and pH of 7.0). Trimethoprim and iopromide were predominantly degraded by ClO2 oxidation and direct UVC photolysis, respectively. Caffeine and ciprofloxacin were predominantly degraded by the radicals (HO• and Cl•) and the in-situ formed free chlorine from ClO2 photolysis, respectively. The yields of total organic chlorine (12.5 µg L−1 from 1.0 mg C L−1 of NOM) and chlorate (0.14 mg L−1 From 1.35 mg L−1 of ClO2) during the co-exposure were low. However, the yield of chlorite was high (0.76 mg L−1 from 1.35 mg L−1 of ClO2), which requires attention and control.

We have developed a three-dimensional (3D) enzyme loading strategy by modular assembly of enzyme loaded nanoparticles with porous conductive membranes. A 3D conductive structure was fabricated as electrode via the poly-(3,4-ethylenedioxythiophene) (PEDOT) in-situ synthesized on hollow fiber membranes (HFMs) framework, retaining the original gradient porous structures and capillary effect. Using physical entrapment pattern, enzyme-carrying nanoparticles were modularly assembled in the 3D conductive support and their spatial distribution can be regulated by particle size-tuning. The obtained enzyme entrapped 3D composites can be applied as a promising electrode in electrochemical sensing and catalysis. HFMs provide large surface area and gradient porous structure for entrapping the enzyme-carrying nanoparticles in the confined micro-space. The physical entrapment improves the enzymatic stability and promotes full contact between the enzymes and the conductive/catalytic substrates. The conductive support creates an interconnected network to increase the electrode area and the response current, thus enhancing the sensitivity of biosensors. It shows fast current response (~3 s), wide linear range (glucose, 2–24 mM; lactic acid, 0.1–6 mM), high sensitivity, and low detection limit (glucose, 100 µM; lactic acid, 10 µM) towards cancer cell metabolism monitoring. This electrode structure can be further applied in multi-target array detection towards metabolic markers by modulating different enzymes on the conductive HFMs.

This study explores the degradation kinetics and mechanisms of N-chloro-α-amino acids and the changes in the formation potential of nitrogenous disinfection byproducts (N-DBPs) upon UV254 irradiation. UV254 irradiation significantly accelerated the degradation of all the tested N-chloro-α-amino acids compared to those in the dark. Both direct photolysis-induced cleavage of the N-Cl bonds and radical oxidation (e.g., Cl• and Cl2•−) involved reactions that contributed to their enhanced degradation. The fluence-based photolysis rate constants of the N-chloro-α-amino acids varied in the range of (1.06—5.47) × 10−3 cm2 mJ−1 at pH 6.0 and (0.74—2.79) × 10−3 cm2 mJ−1 at pH 8.0. The apparent quantum yields (Φapp) of the majority of the N-chloro-α-amino acids were in the range of 0.41−0.95 at pH 6.0 and 0.22−0.79 at pH 8.0, except N-chloroaspartic acid, N-chlorohistidine, and N-chloroalanine. UV254 irradiation significantly enhanced the formation of trichloronitromethane (TCNM) from the tested N-chloro-α-amino acids after post-chlorination, but exhibited various effects on the formation of dichloroacetonitrile (DCAN). A longer UV254 irradiation time generated more TCNM, and a lower pH produced more DCAN from the N-chloro-α-amino acids. The degradation pathways of N-chlorotyrosine, as a representative N-chloro-α-amino acid, are proposed, and the β-scission and 1,2-H shift pathways led to the formation of different precursors of TCNM and DCAN. The results of this study improve our understanding of the fate of N-chloro-α-amino acids under UV254 irradiation and post-chlorination.

Cu(II)-catalyzed hydrolysis of β-lactam antibiotics has been well-identified and recognized as the key mechanism of antibiotic degradation. However, the overlooked Cu(II) oxidation susceptibly also plays an important role comparably with hydrolysis. This study evaluated the roles of hydrolysis and oxidation in Cu(II)-catalyzed degraded ampicillin (AMP), as a typical β-lactam antibiotic, under relevant environmental conditions (pH 5.0, 7.0, and 9.0; oxygen 0.2 and 6.2 mg/L). Under AMP and Cu(II) molar ratio of 1:1, AMP degradation was the fastest at pH 9.0, followed by pH 5.0 and pH 7.0. The facilitation of oxygen on AMP degradation was notable at pH 5.0 and 7.0 rather than pH 9.0. AMP degradation rate increased from 21.8% in 0.2 mg/L O2 solution to 85.9% in 6.2 mg/L O2 solution at pH 7.0 after 4-h reaction. AMP oxidation was attributed to both oxygen-derived Cu(I)/Cu(II) cycle and intermediate reactive oxygen species (HO. and O2 .−). Several intermediate and final products in AMP degradation were firstly identified by LC-quadrupole time-of-flight-MS analysis. Phenylglycine primary amine on the AMP structure was the essential complexation site to proceed with the oxidation reaction. The oxidation of AMP preferentially occurred on the β-lactam structure. The inherent mechanisms related to pH and oxygen conditions were firstly investigated, which could enhance the understanding of both oxidation and hydrolysis mechanisms in AMP degradation. This study not only has an important implication in predicting β-lactam antibiotic transformation and fate in natural environment but also benefits the developing of strategies of antibiotic control to reduce the environmental risk.

Three-dimensional inverse opal (3DIO) ZnO-Fe3O4 composite structure was prepared by a template method and the gas sensing property was investigated toward trace acetone which is an important biomarker of diabetes. The prepared 3DIO composite sensors have large surface area due to both macropores (larger than 100 nm) and mesoporous structure in skeleton, which make the inner surface accessible and provide more active sites to adsorb more oxygen species and target molecules. 3DIO ZnO-Fe3O4 composite sensor exhibits much higher response toward acetone relative to pure ZnO sensor. The optimal 3DIO sensor exhibited a detection limit as low as 100 ppb acetone and showed 40% response increase from 0.9 ppm (healthy humans) to 1.8 ppm (diabetics) which allow reliable diagnosis of diabetic patients by acetone monitoring.

Complete resection of diseased lesions reduces the recurrence of cancer, making it critical for surgical treatment. However, precisely resecting residual tumors is a challenge during operation. A novel integrated spectral-domain optical-coherence-tomography (SD-OCT) and laser-ablation therapy system for soft-biological-tissue resection is proposed. This is a prototype optical integrated diagnosis and therapeutic system as well as an optical theranostics system. We develop an optical theranostics system, which integrates SD-OCT, a laser-ablation unit, and an automatic scanning platform. The SD-OCT image of biological tissue provides an intuitive and clear view for intraoperative diagnosis and monitoring in real time. The effect of laser ablation is analyzed using a quantitative mathematical model. The automatic endoscopic scanning platform combines an endoscopic probe and an SD-OCT sample arm to provide optical theranostic scanning motion. An optical fiber and a charge-coupled device camera are integrated into the endoscopic probe, allowing detection and coupling of the OCT-aiming beam and laser spots. The integrated diagnostic and therapeutic system combines SD-OCT imaging and laser-ablation modules with an automatic scanning platform. OCT imaging, laser-ablation treatment, and the integration and control of diagnostic and therapeutic procedures were evaluated by performing phantom experiments. Furthermore, SD-OCT-guided laser ablation provided precision laser ablation and resection for the malignant lesions in soft-biological-tissue-lesion surgery. The results demonstrated that the appropriate laser-radiation power and duration time were 10 W and 10 s, respectively. In the laser-ablation evaluation experiment, the error reached approximately 0.1 mm. Another validation experiment was performed to obtain OCT images of the pre- and post-ablated craters of ex vivo porcine brainstem. We propose an optical integrated diagnosis and therapeutic system. The primary experimental results show the high efficiency and feasibility of our theranostics system, which is promising for realizing accurate resection of tumors in vivo and in situ in the future.

We propose a novel full-parallax autostereoscopic display based on a lenticular tracking method to achieve separation between the viewing angle and image resolution and to improve these two parameters simultaneously. The proposed method enables the viewing angle to be independent of the image resolution and has the potential to solve the long-term trade-off problem in integral photography. By employing the lenticular lens array instead of the micro-lens array in integral photography with viewing tracking, the proposed method shows a high-image resolution and wide viewing angle 3D display with full parallax. A real-time tracking and rendering algorithm for the display method is also proposed in this study. The experimental results, compared with those of the conventional integral photography display and the tracking-based integral photography display, demonstrate the feasibility of this lenticular tracking display technology and its advantages in display resolution and viewing angle, suggesting its potential in practical three-dimensional applications.

Nanocrystals of the charge transfer compound perylene:7,7′,8,8′-tetracyanoquinodimethane (TCNQ) were created using the reprecipitation method, a simple technique for inducing crystallization in solution by the rapid addition of a miscible non-solvent. The nanocrystal size was followed in situ using dynamic light scattering, showing rapid formation of crystals with sizes on the order of 100 nm followed by much slower growth. The complexation of the electron donor perylene and electron acceptor TCNQ was monitored in situ through the appearance of the charge transfer band in the infrared. Both 1:1 and 3:1 cocrystal stoichiometries could be obtained, but the ratio of the components did not always result in the same stoichiometry in the nanocrystals. In particular, a sample prepared with equal molar amounts of the constituents contained both 1:1 and 3:1 forms, as well as pure perylene and TCNQ nanocrystals. This sample also demonstrated non-classical nucleation, with solid particles forming immediately, but longer range order appearing later.

Purine and pyrimidines are present an important pool of dissolved organic nitrogen in aqueous medias and also precursors of disinfection byproducts. The degradation kinetics of cytosine and adenine—model pyrimidine and purine compounds—were investigated along with their transformation pathways leading to the formation of disinfection byproducts during two typical multi-barrier disinfection processes: UV irradiation and UV/chlorine pretreatment followed by post-chlorination. UV irradiation followed by post-chlorination enhanced the degradation of cytosine and adenine (by 17.1 and 26.1%, respectively), but it also generated more byproduct precursors compared to chlorination alone. The presence of reactive species in the UV/chlorine treatment greatly enhanced cytosine and adenine degradation (by 61.8 and 123.0%) but generated even more disinfection byproducts. Compared to 24 h chlorination, the concentrations of byproducts increased by up to 361.6% for cytosine and 85.1% for adenine with longer UV/chlorine treatment (from 2 to 30 min). Thirty minutes of combined UV/chlorine treatment decreased the total organic chlorine produced from cytosine by 34.4% (from 233.8 to 153.3 μg Cl L−1) but it increased byproduct generation by 68.3% compared with 24 h of simple chlorination. The TOCl from adenine increased by 50.0% (from 9.2 to 18.4 μg Cl L−1) but byproduct generation was 11.0% less after 30 min of UV/chlorine pretreatment followed by 24 h of chlorination. The intermediates generated were analyzed in detail and multiple transformation pathways leading to byproduct formation are proposed.

The integration of luminescence and chirality in easy-scalable metal-organic frameworks gives rise to the development of advanced luminescent sensors. To date, the synthesis of chiral metal-organic frameworks is poorly predictable and their chirality primarily originates from components that constitute the frameworks. By contrast, the introduction of chirality into the pores of metal-organic frameworks has not been explored to the best of our knowledge. Here, we demonstrate that chirality can be introduced into an anionic Zn-based metal-organic framework via simple cation exchange, yielding dual luminescent centers comprised of the ligand and Tb3+ ions, accompanied by a chiral center in the pores. This bifunctional material shows enantioselectivity luminescent sensing for a mixture of stereoisomers, demonstrated for Cinchonine and Cinchonidine epimers and amino alcohol enantiomers, from which the quantitative determination of the stereoisomeric excess has been obtained. This study paves a pathway for the design of multifunctional metal-organic framework systems as a useful method for rapid sensing of chiral molecules., Metal-organic frameworks with luminescence and chirality are promising for luminescent sensors for chiral molecules. Here, the authors use cation exchange to introduce chirality in multifunctional metal-organic framework systems for rapid enantioselective luminescent sensing.

The degradation of pharmaceuticals and personal care products (PPCPs) by using solar photolysis in the presence of free available chlorine (FAC) was investigated in simulated drinking water. The combination of free available chlorine and sunlight irradiation dramatically accelerated the degradation of all the contaminants tested through the generation of hydroxyl radicals, reactive chlorine species (RCS) and ozone. Contaminants containing electron-donating moieties degraded quickly and were preferentially degraded by RCS and/or HO oxidation. Primidone, ibuprofen and atrazine, which contain electron-withdrawing moieties, were mainly degraded by HO . Trace amounts of O3 contributed greatly to carbamazepine's degradation. Degradation of PPCPs was accelerated in oxygenated solutions. Increasing chlorine concentrations barely enhanced removal of PPCPs bearing electron-withdrawing moieties. Higher pH generally decreased the degradation rate constants along with reduced levels of HO and Cl , but diclofenac, gemfibrozil, caffeine and carbamazepine had peak degradation rate constants at pH 7–8. The cytotoxicity using Chinese hamster ovary (CHO) cell did not show significant enhancement in solar/FAC treated water. Combining chlorination with sunlight may provide a simple and energy-efficient approach for improving the removal of organic contaminants during water treatment.

The study of particle transport in porous media is of great significance for pollution mitigation, grouting reinforcement, municipal solid waste landfill management, and groundwater exploitation. We developed an analytical solution for a corrected convection-dispersion model that takes into account the effects of dispersion on deposition kinetics with regard to the particle concentration decay type. The rationality and correctness of the solution were verified using time, distance, deposition coefficient, diffusion coefficient, and decay coefficient. As the time increased, the particle concentration increased from zero to the peak value, then decreased to zero. However, as distance increased, the peak value of particle concentration gradually decreased. The deposition coefficient affected the magnitude of the peak value and the distance corresponding to the peak value. In addition, the greater the attenuation coefficient, the smaller the peak value. Overall, our method’s prediction results showed that considering the effect of dispersion on deposition kinetics produces better results than when this is not considered.

Air pollution by nitrogen oxides, NOx, is a major problem, and new capture and abatement technologies are urgently required. Here we report a metal-organic framework (MFM-520: MFM = Manchester Framework Material) that can efficiently confine dimers of NO2, resulting in a high adsorption capacity of 4.2mmol/g (298K, 0.01bar) with full reversibility and no loss of capacity over 125 cycles. Treatment of NO2@MFM-520 with water in air leads to quantitative conversion of the captured NO2 into HNO3, an important feedstock for fertilizer production, and fully regenerates MFM-520. The confinement of N2O4 inside nano-pores has been established at a molecular level, and dynamic breakthrough experiments using both dry and humid NO2 gas streams verify the excellent stability and selectivity of MFM-520, and confirm its potential for precious-metal-free deNOx technologies.

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

This review focuses on the degradation kinetics and mechanisms of disinfection byproducts (DBPs) under UV and solar irradiation and in UV-based advanced oxidation processes (AOPs). A total of 59 such compounds are discussed. The processes evaluated are low pressure, medium pressure and vacuum UV irradiation, solar irradiation together with UV/hydrogen peroxide, UV/persulfate and UV/chlorine AOPs. Under UV and solar irradiation, the photodegradation rates of N-nitrosamines are much higher than those of halogenated DBPs. Among halogenated DBPs, those containing iodine are photodegraded more rapidly than those containing bromine or chlorine. This is due to differences in their bond energies (EN−N