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Nowadays, ultra wideband (UWB) has been popular in indoor positioning systems. Because of obstacles such as walls, doors, desks and pedestrians in the indoor area, UWB devices have to be conducted in a non-line-of-sight (NLOS) environment. The placement of nodes has significant influences on the performance of localization. In this paper, an anchor placement method for the target’s trajectory based on genetic heuristic differential evolution algorithm is proposed to improve the UWB localization accuracy. To be specific, in an area with low anchor densities, a target does not have enough anchors for multilateration localization; thus, a coverage degree criterion is defined. Meanwhile, the Cramer–Rao lower bound (CRLB) is used as an evaluation metric for localization accuracy, and both of CRLB and coverage degree criterion are incorporated into the evaluation function of the differential evolution (DE) algorithm. Furthermore, instead of using the liner distance path loss model, the more practical UWB-based through-wall signal propagation model is adopted to reflect the influences of obstacles that are widespread in indoor environments. In addition, a software application is developed to visualize the indoor scenario, signal propagation status and anchor placement results. Finally, field experiments and simulations are performed, and a thorough case study confirms the effectiveness of the proposed method. The average localization error of the proposed placement scheme can be reduced by 28.2% and 12.5% compared to the random scheme and the default DE-based scheme.

The dust cake is critical to improve the fine particle collection efficiency in the gas-solid separation process of the granular bed filter (GBF). In this work, the dust cake formation and the corresponding filtration characteristics in a cyclone-granular bed filter (C-GBF) were investigated by experiments under a constant-velocity filtering condition. It was found that cake filtration, deep-bed filtration and the corresponding transitional phenomena could be observed in the C-GBF. A critical porosity was defined to identify the transition from cake filtration to deep-bed filtration. A following parametric study showed that a higher filtration gas velocity could increase the critical porosity and made it more difficult to form a dust cake. It was also demonstrated that the critical porosity was little affected by the dust concentration. However, the time point of the transition of different filtration modes was earlier with a higher dust concentration. The inlet gas velocity ultimately resulted in the different dust concentrations into the GBF. The similar dynamic processes of cake formation were obtained for different granular sizes. These results provided a deeper understanding of the dynamic behaviors of cake formation and filtration mode transition, which played an important role in the design and the scaling-up of the C-GBF filtration systems.

Graphene, as a highly conducting material, incorporated into silk fibroin (SF) substrates is promising to fabricate an electroactive flexible scaffold toward neural tissue engineering. It is well known that aligned morphology could promote cell adhesion and directional growth. The purpose of this study was to develop aligned conductive scaffolds made of graphene and SF (G/SF) by electrospinning technique for neural tissue engineering applications. The physicochemical characterization of scaffolds revealed that the mechanical and electrochemical property of aligned G/SF scaffolds continually raised with the increasing contents of graphene (A0% G/SF, A1% G/SF, A2% G/SF, and A3% G/SF), but the mechanical property descended when the graphene concentration reached to 4% (the A4% G/SF group). The results of the cell experiment in vitro indicated that all the aligned G/SF scaffolds were no neurotoxic to primary cultured spinal cord neurons. In addition, the neurite elongation in all aligned groups was significantly enhanced by the upregulation of Netrin-1 expression compared to them in the control group. Thus, A3% G/SF scaffolds not only possessed the optimal property based on the mechanical and electrochemical performances but also displayed the beneficial capability to neurite outgrowth, which might perform a suitable candidate to successfully scaffold electrically active tissues during neural regeneration or engineering.

The rapid and efficient filtration of particles from high temperature pyrolysis vapors is of crucial importance for enhancing yields and quality of pyrolysis oil. In this work, an integrated dust removal technology of cyclone-granular bed filter (C-GBF) was designed. A computational fluid dynamics (CFD) simulation of the flow pattern of the C-GBF was carried out. The Reynolds stress model (RSM) and discrete phase model (DPM) were used to describe the gas-solid flow behavior in the C-GBF. The simulated results demonstrated that the flow pattern characterized by a free vortex in the C-GBF was observed. The location of maximum tangential velocity was found to be at the inlet section and the maximum value was about 1.2 times larger than the inlet gas velocity. The pressure drop of the C-GBF was mainly affected by the granular bed with the free vortex playing a trivial role. Based on the understanding of flow characteristics of the free vortex, the effects of the inlet gas velocity and filtration gas velocity on separation performance of the C-GBF were analyzed. The feasibility of the C-GBF was further examined by laboratory experiments under a constant-velocity filtration condition. The matching condition of the C-GBF was obtained with an inlet gas velocity of 30 m/s and the corresponding filtration gas velocity of 0.4 m/s.

Drug delivery systems (DDSs) limited to a single function or single-drug loading are struggling to meet the requirements of clinical medical applications. It is of great significance to fabricate DDSs with multiple functions such as magnetic targeting or fluorescent labeling, as well as with multiple-drug loading for enhancing drug efficacy and accelerating actions. In this study, inspired by the dual-chamber structure of rapeseed pods, biomimetic magnetic–luminescent bifunctional drug delivery carriers (DDCs) of 1.9 ± 0.3 μm diameter and 19.6 ± 4.4 μm length for dual drug release were fabricated via double-needle electrospraying. Morphological images showed that the rapeseed pod-like DDCs had a rod-like morphology and Janus dual-chamber structure. Magnetic nanoparticles and luminescent materials were elaborately designed to be dispersed in two different chambers to endow the DDCs with excellent magnetic and luminescent properties. Synchronously, the Janus structure of DDCs promoted the luminescent intensity by at least threefold compared to single-chamber DDCs. The results of the hemolysis experiment and cytotoxicity assay suggested the great blood and cell compatibilities of DDCs. Further inspired by the core–shell structure of rapeseeds containing oil wrapped in rapeseed pods, DDCs were fabricated to carry benzimidazole molecules and doxorubicin@chitosan nanoparticles in different chambers, realizing the sequential release of benzimidazole within 12 h and of doxorubicin from day 3 to day 18. These rapeseed pod-like DDSs with excellent magnetic and luminescent properties and sequential release of dual drugs have potential for biomedical applications such as targeted drug delivery, bioimaging, and sustained treatment of diseases.

Electrical or mechanical stimulation has been applied widely in bone fracture treatment or bone tissue construction. The effect of combined mechanical and electrical stimulation to osteoblasts or bone tissue has not been deeply studied, which would provide a more actual simulation of in vivo microenvironment. In this study, a cell culture device that can simultaneously load mechanical and electrical stimulation on cells was self-designed and fabricated. The combined laminar shear stress and electrical stimulation could be supplied to MC3T3-E1 cells seeded on the nano-crystalline fluorine-doped tin oxide glass plate. Cell counting kit-8 assay was used to study the proliferation of MC3T3-E1 cells. The changes in alkaline phosphatase activities, genes expression of collagen-I (Col-I) and fibronectin and concentration of Col-I were also measured. Compared with single stimulation, the combined stimulation obviously enhanced proliferation, differentiation and synthesis of extracellular matrix of pre-osteoblasts in a greater extent. The combined mechanical and electrical stimulation provide a new way to promote in vitro cultivation of cells and tissues, which will be very significant in the development of tissue engineering.

It is generally recognized that internal-loop reactors are well-developed mass and heat-transfer multiphase flow reactors. However, the internal flow field in the internal-loop reactor is influenced by the structure parameter of the reactor, which has a great effect on the reaction efficiency. In this study, the computational fluid dynamics simulation method was used to determine the influence of reactor structure on flow field, and a volume-of-fluid model was employed to simulate the gas–liquid, two-phase flow of the internal-loop micro-electrolysis reactor. Hydrodynamic factors were optimized when the height-to-diameter ratio was 4:1, diameter ratio was 9:1, draft-tube axial height was 90 mm. Three-dimensional simulations for the water distributor were carried out, and the results suggested that the optimal conditions are as follows: the number of water distribution pipes was four, and an inhomogeneous water distribution was used. According to the results of the simulation, the suitable structure can be used to achieve good fluid mechanical properties, such as the good liquid circulation velocity and gas holdup, which provides a good theoretical foundation for the application of the reactor.

The degradation of nitrobenzene by synchronistic oxidation and reduction was investigated using an internal circulation microelectrolysis (ICE) reactor with an active volume of 0.018 m3. Compared with a conventional fixed bed reactor with and without aeration, the ICE reactor exhibited a markedly higher nitrobenzene degradation efficiency. The effects of various operational parameters such as reaction time, aeration rate, initial nitrobenzene concentration, initial pH, and a volume ratio of iron and carbon (Fe/C) were also investigated. The optimal operating conditions (reaction time = 60 min, aeration rate = 5 × 10−4 m3/s, initial concentration of nitrobenzene = 300 mg/L, pH = 3.0, Fe/C = 1:1) gave removal efficiencies of nitrobenzene and chemical oxygen demand of 98.2% and 58%, respectively. The biodegradability index of the treated nitrobenzene solution was 0.45, which is 22 times that of the original solution. The reaction intermediates were identified through high-performance liquid chromatography, ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and ion chromatography. The primary intermediates were determined to be aniline, phenol, and carboxylic acids, indicating that nitrobenzene was synchronously oxidized and reduced in the ICE reactor. Based on the identified intermediates, a possible pathway for nitrobenzene degradation in the ICE reactor is proposed.

Development of bone tissue engineering has provided a promising method for bone rehabilitation. Tissue engineering scaffolds with magnetic or conductive properties may conduct electric or magnetic signals and bring out synergetic promoting effect to cells growth. In this work, polypyrrole (PPy)/Fe₃O₄/polylactic acid-glycolic acid (PLGA) magnetic-conductive bifunctional fibrous scaffolds were prepared through in-situ polymerization of pyrrole on Fe₃O₄/PLGA fibers. The prepared magnetic-conductive bifunctional PPy/Fe₃O₄/PLGA fibrous scaffolds showed good conductive and magnetic properties to deliver electrical and magnetic signals. The PPy/Fe₃O₄/PLGA fibrous scaffolds had a conductivity of 0.58 S/cm at 180 mM pyrrole and still remained with good fibrous morphology. MC3T3-E1 pre-osteoblasts inoculated on PPy/Fe₃O₄/ PLGA scaffolds under double electrical stimulation (ES) and magnetic stimulation (MS) demonstrated highest cell viabilities compared with those under single ES, MS or without any stimulation. The enhancement of cell viabilities by the Fe₃O₄/PLGA and PPy/Fe₃O₄/PLGA fibrous scaffolds from 1 to 5 d culture indicate that both of them had good biocompatibility. MS can also induce cell alignment arrangement on the magnetic scaffolds according to resultant cell scanning electron microscope (SEM) images. In addition, better hydrophilicity and thermal stability of the PPy/Fe₃O₄/PLGA fibrous scaffolds, as compared to Fe₃O₄/PLGA fibrous scaffolds, allowed the bifunctional scaffolds wide application in bone tissue engineering.

INTRODUCTION: Sirtuin1 (SIRT1), one of NAD(+)-dependent protein deacetylases, is proved to be neuroprotective in aging diseases, but its effect on neuronal apoptosis has not been clarified. To investigate the role of SIRT1 in inhibiting neuronal apoptosis, SIRT1 was interfered or overexpressed in cortical neurons. METHODS: We exerted overloading laminar shear stress with 10 dyn/cm(2) for 4, 8, and 12 h on neurons to cause cortical neuronal apoptosis, and the apoptosis percentage was tested by TUNEL assay. The adenovirus plasmids containing SIRT1 RNA interference or SIRT1 wild type gene were transfected into neurons before shear stress loading. SIRT1 mRNA and protein level were tested by Real-time PCR, immunofluorescence and western blots assay. RESULTS: SIRT1 was primarily expressed in nucleus of cortical neurons, and its mRNA level was significantly increased after 4 h stimulation. SIRT1 RNAi cortical neurons had higher TUNEL positive cells, while SIRT1 overexpression significantly decreased the percentage of died cells induced by shear stress compared to control group. CONCLUSIONS: SIRT1 plays a neuroprotective role in shear stress induced apoptosis and could be as potential pharmacological targets against neuronal degeneration in future.

Now science and technology are developing rapidly, and the microelectronics, wireless, and network technologies are also developing rapidly. At the same time, people's living standards are constantly improving, and the requirements for the safety and convenience of the places where they live are becoming higher and higher. In smart residential buildings, people are more in urgent need of a new type of wireless doorbell product, which can integrate the advantages of reliability, security, convenience and so on, so the design of intelligent voice message doorbell has become a hot spot. The design consists of STC89C52 single-chip microcomputer circuit, 315M wireless module circuit, voice recording and playback circuit, music chip circuit key circuit and power circuit. Wireless data transmission is carried out by the 315M wireless remote control module, which has a long transmission distance and strong anti-interference ability. Outsiders can record voice and leave messages through the recording module. This system has low price, relatively stable performance, wide application range, and very promising market.

In order to understand the asphalt separation processes in a new technique of solvent deasphalting, the hydrodynamics of the jet-driven swirling flow within a spray granulation tower (SGT) ...

Nanomaterials of graphene and its derivatives have been widely applied in recent years, but whose impacts on the neuronal guidance growth are still not reported. In the present study, graphene oxide (GO) and carboxylated graphene oxide (GO-COOH) were used to investigate the potential effects on axonal guidance growth in the primary cultured cortical neurons. In addition, we characterized the structure and chemical composition of synthesized GO and GO-COOH using Fourier transform infrared spectrophotometer and scanning electron microscope assays and Raman analysis. GO is not neurotoxic and not conductive in a soluble form. However, GO-COOH has higher solubility and conductivity. Cell viability was assessed using CCK-8 assays and fluorescein diacetate after GO and GO-COOH treatment (0, 1, 2, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 50, and 100 µg/mL). There are significant increases of cell viability and axonal growth after GO (2 and 4 μg/mL) and GO-COOH treatment (2 and 4 μg/mL). We further investigated the molecular mechanism of axonal guidance growth after GO and GO-COOH (2 and 4 μg/mL) application. Additionally, GO and GO-COOH up-regulated expression of Netrin-1 and its receptor, deleted in colorectal cancer by immunofluorescence assays and western blots assay. Our study demonstrated that GO-COOH activated Cdc42 and Rac1 and dramatically decreased RhoA. Thus, GO-COOH (2 µg/mL) is much better to be nanocarriers than GO for axonal guidance and growth in this study. GO-COOH may be used to facilitate guidance for regenerating neurons in the future. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1500-1510, 2018.

A novel hydrocyclone with guide vanes, named as axial hydrocyclone (AHC), is designed to tackle the problem of oil–water separation faced by most mature oilfields. Optimal design of the AHC is carried out by using numerical methods. The effects of guide vanes, cone angle, tapered angle and overflow pipe on the oil–water separation are discussed in this paper. The results show that a double swirling flow is generated in the tapered section where oil–water separation occurs. Both the cylindrical and the tapered section have important influences on AHC performance. On the basis of single factor results, response surface methodology is employed to optimize the AHC design. The experimental results indicate that the novel AHC has an excellent performance for the oil–water separation.

H2O2 is a green, environmentally friendly potential energy source. The photocatalytic reduction of molecular oxygen to synthesise H2O2 is an eco-friendly strategy compared with the anthraquinone method and H2/O2 direct synthesis. We proposed oxygen-enriched carbon nitride polymer (OCN) models, which were proven to more easily produce 1,4-endoperoxide species and have a high selectivity for molecular oxygen reduction to H2O2, rather than superoxide radicals, through theoretical calculations and experiments. The apparent quantum yield for H2O2 production by OCNs reached 10.2% at 420 nm under an O2 atmosphere, which was 3.5 times higher than that of g-C3N4 and the activity did not decay over 20 h. OCN has a better oxygen reducibility and electron–hole separation efficiency than g-C3N4 and is more prone to 2-electron reduction in the ORR. This work promotes understanding of the mechanism of photocatalytic oxygen reduction and provides a new idea for the design and synthesis of new materials for the preparation of H2O2.

Electrical stimulation (ES) and magnetic stimulation (MS) can promote bone tissue formation in vivo. Loading ES and MS simultaneously would be very beneficial for bone tissue construction in vitro or in vivo. Magnetic-conductive bi-functional scaffolds which are favorable for the transfer of ES and MS, could further facilitate bone cell/tissue growth. Poly(3,4-ethylenedioxythiophene) (PEDOT)/Fe3O4/polylactic acid-co-glycolic acid (PLGA) magnetic-conductive bi-functional fibrous scaffolds were prepared through in situ polymerization of EDOT on Fe3O4/PLGA fibers. MC3T3-E1 pre-osteoblasts were incubated on the PEDOT/Fe3O4/PLGA fibrous scaffolds and were stimulated by electrical, magnetic and electrical–magnetic signals respectively to detect the impact of different stimulation on cell viability. The measured results show that the scaffolds possess good conductivity and superparamagnetic responsiveness. Furthermore, both electrical and magnetic stimulation promoted cell proliferation and magnetic stimulation could induce cell alignment arrangement. Meanwhile, under electrical–magnetic double stimulation, cell viability was much higher than for cells under single electrical or magnetic stimulation. The growth promoting effects of PEDOT/Fe3O4/PLGA fibrous scaffolds under electrical–magnetic double stimulation has great practical potential for bone tissue engineering.

In the communication network, since the interconnection of a large number of components, mobile network operators run Operations Support Systems that generate vast amounts of alarm events. The harsh challenge for network operators is how to find the potential root causes from massive alarms in real time. In this paper, we propose a novel solution for the root causes analysis. The solution includes a silent gap based approach to resolve the asynchrony of alarms, an algorithm for constructing Bayesian network (BN) based on sequentiality between alarms, and Bayesian inference to identify the root causes. The silent gap-based approach reduces preprocessing time while taking into account the validity. Also, the proposed BN-based mechanism allows the identification of the root causes with a higher accuracy. Experiments conducted on a real alarm dataset are provided to support the proposed methods. In addition, we propose a new algorithm processing framework.

Oily wastewater needs to be effectively treated to minimize the hazardousness to the environment. Flotation is an excellent pre-treatment technology for low-content oily wastewater with small oil droplets. The separation process of flotation is very complicated and involves the theories of thermodynamics, kinetics and hydrodynamics. Despite the numerous theoretical, numerical simulation and experimental investigations, the mechanism of flotation remains far from been fully understood. This paper uses the CFD-PBM numerical simulation method to research the dynamic separation characteristics of oil droplets including the oil droplet diameter distribution, the Sauter-Mean diameter, and the oil-water separation efficiency under different circulating flow rates (Corresponding to different turbulent kinetic energy) both from micro and macro scale. The results showed that the oil droplet diameter distribution is consistently changing during the separation process because of coalescence and breakup of oil droplets. The improvement of turbulent kinetic energies or turbulence intensity can effectively promote the collision efficiency of oil droplets and accelerate the oil-water separation process. While the turbulent kinetic energies or turbulence intensity is too strong, the strong shear stress of the fluid will promote the breakage of oil droplets and result in the decrease of oil-water separation efficiency. When the circulating flow rate is about 0.75 m 3 /h, the collision and coalescence efficiency of oil droplets is strong enough and the shear stress of the fluid is relatively weaker, and the oil-water separation efficiency reached the highest of 75%. The numerical simulation results are verified by the experimental results and it shows that the simulation results are in agreement with the experimental results both from micro scale and macro scale, which indicates that the numerical simulation method of CFD-PBM are stable and reliable.

The 10-layer unbonded flexible riser is modeled with parametric modeling technology in FEM and the model is imported into ABAQUS to simulate the riser mechanical behavior under the torsion loading conditions. The FEM model considering material nonlinearity and nonlinear boundary conditions (the interaction between layers) has been set to simulate the riser behavior. Based on the detailed finite element model, the influence of friction coefficient on the calculation results of the riser under torsion force is studied. The computation results reveal a large difference between the internal layers and the tension armor consisting of steel strips, which is the main load-bearing component. Friction coefficient is shown to have a strong effect on the stress-strain calculation results.

Rod-like microparticles are important drug delivery systems for their large specific surface area and high cell uptake rate. However, complex preparation methods, such as mechanical stretching and cutting after electrospinning restrict applications of rod-like microparticles. In this study, uniformly sized microrods were fabricated via one-step electrospray by using poly(lactide-co-glycolide) (PLGA) solutions with low viscosity, mainly low concentration, and low molecular weights. In contrast to previous results that polymer beads are usually obtained with low-concentration precursor solutions, we prepared 0.5–2.0 μm diameter and 4–20 μm long microrods when the concentration of the solution and molecular weight of the polymer were further decreased. Moreover, the aspect ratio of the microrods decreased significantly after upregulating the loading voltage, adding salt, and using high permittivity solvents. It is suggested that the formation of microrods with an aspect ratio of 4.51·N (N = 1, 2, 3…) was based on the surface wave theory, which was tallied with the experimental data. Furthermore, the doxorubicin(DOX)@PLGA microrods showed higher entrapment efficiency and drug-loading capacity as a drug delivery system compared with those of DOX@PLGA microspheres. Microrods have the potential for a broader range of applications in biomedicine due to the easy preparation process of one-step electrospray.

Huge amounts of produced water are generated in offshore oil production. The Compact Flotation Unit (CFU) is an excellent pretreatment technology of produced water with high separation efficiency, low residence, and small split ratio. The Computational Fluid Dynamics-population balance model (CFD-PBM) method is used in the present work to study the oil–water separation characteristics in the self-developed Beijing Institute of Petrochemical Technology Compact Flotation Unit (BIPTCFU) at both micro-scale and macro-scale, which would help us gain more insights into the mechanism and the influence of flow field on the oil–water separation process such as the oil droplets’ diameter distribution and separation efficiency. The effects of the inlet diameter, the height of the preliminary separation zone, and the width of the annular space on the oil–water separation characteristics of CFU were discussed systematically. It is illustrated that the appropriate increase of inlet velocity, decrease of annular...

A novel micro-electrolysis reactor bringing iron-carbon filler to cycle flow was developed in this study, called as an internal circulation micro-electrolysis (ICE) reactor, which can overcome the disadvantage of conventional fixed bed (CFB) reactor. In order to investigate the performance of the ICE reactor, a practical dyes wastewater was selected as target wastewater. The removal efficiency of chemical oxygen demand (COD) and chroma of the CFB reactor with commercial hardening resistance iron-carbon filler (CRIF) are only 23% and 40%, respectively. However, for the ICE reactor with a common iron-carbon mixture (CIM), the removal efficiency of COD and chroma are 73% and 98.5%, respectively. The improvement efficiency of biodegradability index of dyes wastewater for the ICE reactor with the CIM is 23 times, which is about fourfold as much as that of the CFB reactor with CRIF. The ICE reactor with CIM can stably keep a high treatment performance for 60 days continuous operation. However, the performance of CFB reactor with CIM decreases sharply. The results indicate that the ICE reactor has an excellent performance for the pretreatment of dyes wastewater, which should be due to the elimination of hardening, blocking and inactivation occurring in the CFB reactor with CIM by the circulation action.

The hydrodynamics of a jet-driven swirling flow has a dramatic influence on the separation performance of a spray granulation tower. To understand the macro-instabilities of the flow patterns, this work performs a detailed study on the gas flow field in a spray granulation tower with an array of nozzles. The experimental results attained by a phase Doppler particle analyzer (PDPA) indicate that the flow field is in a fully turbulent state and that a low-frequency oscillation exists in the spray granulation tower. The velocity profiles and frequency distributions obtained using the full-scaled grid system and the Reynolds stress model are in good agreement with experimental data. Based on the observed flow field, a general flow pattern is summarized. Both the experimental and numerical results indicate that a quasi-periodic unsteady velocity flow is observed in the spray granulation tower. Compared with the original spray granulation tower, it is beneficial for reducing the flow oscillation and velocity fluctuation when the baffle is added. The flow stability criterion proposed in this study can characterize the flow state in the spray granulation tower.

The mechanistic role of adenine, which assists the catalytic activity of low-molecular weight phosphatases, has been investigated using ONIOM calculations. Results confirm the dephosphorylation step being the rate-limiting step. In the absence and presence of adenine, the energy barriers of the rate-limiting step are 16.0 kcal/mol and 14.3 kcal/mol respectively, in agreement with experimental data. The formation of the favorable hydrogen bond contributes to the decreasing of barrier energy, resulting in the optimized attacking angle of the nucleophile. These results support the notion that adenine disfavors the formation of adverse hydrogen bond, which enables more effective hydrolyzation of phosphoenzyme intermediate.

The filter packing of traditional iron–carbon micro-electrolysis reactors is prone to hardening and passivation during operation. In this study, internal loop airlift reactors were used to contain iron–carbon fillings in order to solve these problems and realize a synchronistic oxidation and reduction environment in an internal circulation micro-electrolysis (ICE) reactor. The hydrodynamics of the novel gas–liquid–solid three-phase reactor were investigated through a computational approach. A 2D and 3D transient Eulerian–Eulerian multiphase model was carried out with the standard k − e turbulence model. Important design parameters of the ICE reactor were identified: the solid velocity, radial profiles of the axial gas holdup and water distribution. The effects of the mesh grid size sensitivity, superficial gas velocity, riser diameter (Dr), height–diameter ratio (H/D), draft tube axial height (Hd) and number of water distribution pipes were considered. The key observations were as follows. The minimum fluidization velocity was 1 m·s−1. With the increase in the number of distribution pipes, the distribution of water was more uniform, but the solid flow resistance increased. When Dr = 30 mm, H/D = 4:1, Hd = 90 mm, and the number of distribution pipes was 4, the hydrodynamic performance was observed to be better. The dissolved oxygen distribution was simulated based on the optimum structural parameters. The experimental results have the same trend as the simulation results, and synchronistic oxidation and reduction was verified in the ICE reactor. Therefore, the optimum structural design and operating parameters and the three-phase system theory were obtained through the CFD simulation, and these findings will provide a basis for the design and enlargement of the ICE reactor.

Microspheres with magnetic-fluorescent functions have received attention due to fluorescent tracking and target positioning. To improve the accuracy of optical imaging and the fluorescent tracking of drug release, it is essential to enhance the fluorescent intensity of microparticles. Magnetic-fluorescent bifunctional poly lactic-co-glycolic acid (PLGA) Janus microspheres [PLGA/TbLa3(Bim)12]//[PLGA/Fe3O4] with double chambers were fabricated with the double-needle electrospraying method. The fluorescent drug TbLa3(Bim)12 with dual rare earth ions was encapsulated in one chamber, while Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were simultaneously encapsulated in another chamber. In comparison, magnetic-fluorescent PLGA composite microspheres PLGA/TbLa3(Bim)12/Fe3O4 were also prepared, which encapsulated fluorescent drugs TbLa3(Bim)12 with dual rare earth (RE) ions and Fe3O4 MNPs in one chamber. The fluorescent intensity at 542 nm of Janus microspheres was about three times higher than that of composite microspheres due to a decrease in contact between fluorescent-labeling RE drug and MNPs. The fluorescent intensities of Janus microspheres with different contents of Fe3O4 MNPs and TbLa3(Bim)12 were investigated. Furthermore, the magnetic properties, thermostability, cell toxicity and hemolytic properties of Janus microspheres were also assayed to conduct a tentative exploration of their bioapplication. The Janus microspheres provide many opportunities for application in biofields such as drug delivery.

RhBMP-2 has shown great promise for the reconstruction of teeth segmental bone defects due to its osteoinductive properties. But the application of rhBMP-2 is limited by its weak drug controled release. It is usually loaded in a Chitosan Microspheres (CMs) delivery system with excess single cross-linker and then removed before practice. In this study, cross-linkers were replaced with RhBMP-2 which contains vanillin and vitriolic acid, and thus CMs were developed. The materials were studied by SEM, FTIR and drug release experiments. It showed an ideal releasing profile and excellent osteoconductive and osteoinductive performance in the delivery system. Therefore, designing biomaterials with a controllable delivery system composite and releasing profile of rhBMP-2 are critical for applications of bone regeneration and tissue engineering.