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Calcium silicate hydrate (C‐S‐H) synthesis follows multistep nucleation processes ranging from amorphous globules to nanocrystals. This type of nonclassical nucleation pathway attracts extensive interest and yet related molecular processes are mostly unexplored. Herein, atomic‐level structure evolution during this process is unveiled. From inside to outside of the globule, the atomic arrangement evolves from amorphous configuration to layered stacking of calcium silicate layers with layers spaced by 1.1 nm. Numerous cations surrounding the globules provide extra calcium ions to form nano C‐S‐H foils at the edge of the globule. The polymerization to form calcium silicate chains has almost been completed before 5 min reaction, and the C‐S‐H structure formation is basically based on the self‐assembly to be calcium silicate layers and then lamellar crystal inside the globule. Silicate chain defects inhibit a‐ and c‐axes crystallization, but promote b‐axes one, leading to anisotropic growth of crystalline C‐S‐H. The defects lead to the crystallization pathways conversion from Si–O–Si bonds formation to Ca2+ electrostatic linking. [ABSTRACT FROM AUTHOR]

Nanozymes have demonstrated significant potential in combating malignant tumor proliferation through catalytic therapy. However, the therapeutic effect is often limited by insufficient catalytic performance. In this study, we propose the utilization of strain engineering in metallenes to fully expose the active regions due to their ultrathin nature. Here, we present the first report on a novel tensile strain‐mediated local amorphous RhRu (la‐RhRu) bimetallene with exceptional intrinsic photothermal effect and photo‐enhanced multiple enzyme‐like activities. Through geometric phase analysis, electron diffraction profile, and X‐ray diffraction, it is revealed that crystalline‐amorphous heterophase boundaries can generate approximately 2 % tensile strain in the bimetallene. The ultrathin structure and in‐plane strain of the bimetallene induce an amplified strain effect. Both experimental and theoretical evidence support the notion that tensile strain promotes multiple enzyme‐like activities. Functioning as a tumor microenvironment (TME)‐responsive nanozyme, la‐RhRu exhibits remarkable therapeutic efficacy both in vitro and in vivo. This work highlights the tremendous potential of atomic‐scale tensile strain engineering strategy in enhancing tumor catalytic therapy. [ABSTRACT FROM AUTHOR]

Nanozymes have demonstrated significant potential in combating malignant tumor proliferation through catalytic therapy. However, the therapeutic effect is often limited by insufficient catalytic performance. In this study, we propose the utilization of strain engineering in metallenes to fully expose the active regions due to their ultrathin nature. Here, we present the first report on a novel tensile strain‐mediated local amorphous RhRu (la‐RhRu) bimetallene with exceptional intrinsic photothermal effect and photo‐enhanced multiple enzyme‐like activities. Through geometric phase analysis, electron diffraction profile, and X‐ray diffraction, it is revealed that crystalline‐amorphous heterophase boundaries can generate approximately 2 % tensile strain in the bimetallene. The ultrathin structure and in‐plane strain of the bimetallene induce an amplified strain effect. Both experimental and theoretical evidence support the notion that tensile strain promotes multiple enzyme‐like activities. Functioning as a tumor microenvironment (TME)‐responsive nanozyme, la‐RhRu exhibits remarkable therapeutic efficacy both in vitro and in vivo. This work highlights the tremendous potential of atomic‐scale tensile strain engineering strategy in enhancing tumor catalytic therapy. [ABSTRACT FROM AUTHOR]

As an environmentally friendly natural polymer, citric acid-modified chitosan (CAMC) can effectively regulate the hydration and exothermic processes of cement-based materials. However, the influence of CAMC on the macroscopic properties of concrete and the optimal dosage are still unclear. This work systematically investigates the effects of CAMC on the mixing performance, mechanical properties, shrinkage performance, and durability of concrete. The results indicated that CAMC has a thickening effect and prolongs the setting time of concrete. CAMC has a negative impact on the early strength of concrete, but it is beneficial for the development of the subsequent strength of concrete. With the increase in CAMC content, the self-shrinkage rate of concrete samples decreased from 86.82 to 14.52 με. However, the CAMC-0.6% sample eventually expanded, with an expansion value of 78.49 με. Moreover, the long-term drying shrinkage rate was decreased from 551.46 to 401.94 με. Furthermore, low-dose CAMC can significantly reduce the diffusion coefficient of chloride ions, improve the impermeability and density of concrete, and thereby enhance the freeze–thaw cycle resistance of concrete. [ABSTRACT FROM AUTHOR]

The fabrication of blue perovskite light‐emitting diodes (PeLEDs) in air conditions promises to liberate the manipulation procedures from the protection of inert atmosphere in the glovebox, which will remarkably promote the commercialization proceeding of perovskite‐based optoelectronic devices in display applications. However, achieving air‐processed blue PeLEDs in the interference of moisture meets great challenges in crystallization kinetics control. Herein, it is proposed that substrate‐adsorbed moisture dominates the perovskite crystallization kinetics during the fabrication in air, and the limited moisture from nonhygroscopic substrate inhibits the nucleation of the large‐n phase and allows the growth of the small‐n phase, thus yielding blue quasi‐2D perovskite films in a wide moisture range of 10–50% relative humidity. Then, air‐processed blue PeLEDs are successfully achieved for the first time, showing a brightness of 968 cd m−2, external quantum efficiency of 2.54% at stable peak emission of 483 nm, as well as an outstanding operating stability of 546 s at a peak brightness of 45 cd m−2, which are favorably competitive with PeLEDs fabricated in the glovebox. This work provides a guideline for air‐processed blue PeLEDs fabrication, which paves the way for air‐processed PeLEDs in further application of commercialization display. [ABSTRACT FROM AUTHOR]

Accelerating slow water dissociation kinetics is key to boosting the hydrogen evolution reaction (HER) in alkaline media. We report the synthesis of atomically dispersed MoOx species anchored on Rh metallene using a one‐pot solvothermal method. The resulting structures expose the oxide‐metal interfaces to the maximum extent. This leads to a MoOx‐Rh catalyst with ultrahigh alkaline HER activity. We obtained a mass activity of 2.32 A mgRh−1 at an overpotential of 50 mV, which is 11.8 times higher than that of commercial Pt/C and surpasses the previously reported Rh‐based electrocatalysts. First‐principles calculations demonstrate that the interface between MoOx and Rh is the active center for alkaline HER. The MoOx sites preferentially adsorb and dissociate water molecules, and adjacent Rh sites adsorb the generated atomic hydrogen for efficient H2 evolution. Our findings illustrate the potential of atomic interface engineering strategies in electrocatalysis. [ABSTRACT FROM AUTHOR]

Accelerating slow water dissociation kinetics is key to boosting the hydrogen evolution reaction (HER) in alkaline media. We report the synthesis of atomically dispersed MoOx species anchored on Rh metallene using a one‐pot solvothermal method. The resulting structures expose the oxide‐metal interfaces to the maximum extent. This leads to a MoOx‐Rh catalyst with ultrahigh alkaline HER activity. We obtained a mass activity of 2.32 A mgRh−1 at an overpotential of 50 mV, which is 11.8 times higher than that of commercial Pt/C and surpasses the previously reported Rh‐based electrocatalysts. First‐principles calculations demonstrate that the interface between MoOx and Rh is the active center for alkaline HER. The MoOx sites preferentially adsorb and dissociate water molecules, and adjacent Rh sites adsorb the generated atomic hydrogen for efficient H2 evolution. Our findings illustrate the potential of atomic interface engineering strategies in electrocatalysis. [ABSTRACT FROM AUTHOR]

Space charge problems have been widely acknowledged for solid insulation such as polyethylene for high-voltage dc cable insulation. However, the effect of space charge on the reliability of high-voltage power module packaging insulation has not been systematically investigated. In this article, a simultaneous measurement of space-charge and isothermal relaxation current (IRC) is performed on silicone packaging insulation. An iterative algorithm based on the nonnegative least-square method is introduced to estimate multilevel trap energy distribution in silicone insulation. It is found that homocharges are accumulated around the electrodes, and more charges are accumulated with the increase in applied electric field and temperature. The local electrical field is distorted, and the threshold of the external applied electric field for charge accumulation decreases with increasing temperature. The trapped charges tend to be trapped in deep traps as the temperature increases. Furthermore, to investigate the charge dynamics in the complex power module package structure, a 2-D space-charge simulation model based on the combination of the bipolar charge transport model and finite-element method (FEM) is proposed with the parameters derived from the simultaneous measurement. According to the simulation results, the maximum electric field is located at the triple-junction position of the high-voltage power module package. With the accumulation of homocharges and the increase in temperature, the electric field decreases at the triple-point position but increases between the injected positive and negative charges. Space-charge behavior affects the local electric field of power module packaging insulation and should be thoroughly investigated in the future. [ABSTRACT FROM AUTHOR]

A library of 23 synthetic heparan sulfate (HS) oligosaccharides, varying in chain length, types, and positions of modifications, was used to analyze the substrate specificities of heparin lyase III enzymes from both Flavobacterium heparinum and Bacteroides eggerthii. The influence of specific modifications, including N-substitution, 2-O sulfation, 6-O sulfation, and 3-O sulfation on lyase III digestion was examined systematically. It was demonstrated that lyase III from both sources can completely digest oligosaccharides lacking O -sulfates. 2-O Sulfation completely blocked cleavage at the corresponding site; 6-O and 3-O sulfation on glucosamine residues inhibited enzyme activity. We also observed that there are differences in substrate specificities between the two lyase III enzymes for highly sulfated oligosaccharides. These findings will facilitate obtaining and analyzing the functional sulfated domains from large HS polymer, to better understand their structure/function relationships in biological processes. [ABSTRACT FROM AUTHOR]

In this paper, the semi-theoretical kinetics equations were proposed and the electro-dewatering experiments of sludge were conducted to analyze the kinetics laws of electro-dewatering under constant voltage and constant current. The results showed that the decline rate of moisture content remained stable under constant current, while the decline rate of moisture content kept decaying in the operating mode of constant voltage. No matter in what kind of operating mode, the change in decline rate of moisture content was consistent with that of filtrate flow rate, both of which were essentially dependent on the current. The follow-up electro-dewatering tests under constant voltage were carried out by using three different kinds of sludge to understand the mechanism of electro-dewatering. The results showed that the main parameters that controlled the electro-dewatering behavior were measured current, conductivity and zeta potential of sludge. When treated at 30 V, sludge C reached the lowest moisture content, owing to its higher conductivity and zeta potential. However, the poorer electro-osmotic effect of sludge C led to its higher average unit energy consumption. By comparison, an increase of applied voltage was more effective for electro-dewatering process of sludge C but at the expense of higher energy consumption, while sludge A and B were more inclined to improve the electro-dewatering effect by extending the dewatering time. Finally, the derived equations were demonstrated by the experiments, which could provide guidance for the practical applications. [ABSTRACT FROM AUTHOR]

We designed an efficient self-quenching fluorescence probe and constructed this probe-mediated exponential isothermal amplification system for miRNA detection. Owing to the significant improvement in the detective signal-to-background ratio, a wide dynamic range of 9 orders of magnitude and a limit of detection as low as 0.08 aM can be easily achieved in a single step. Furthermore, benefiting from the additional advantages of high specificity and biocompatibility, the proposed method has been demonstrated to be capable of accurately quantifying miRNA biomarkers in serum, which will provide promising perspectives for clinical diagnosis. [ABSTRACT FROM AUTHOR]

Generating oxygen vacancies is an effective way to improve the lithium-ion storage performance of V2O5. However, the mechanism has not been theoretically investigated. In this study, first-principle calculations were performed to study the effect of oxygen vacancy on electrochemical properties of γ-V2O5 as cathode material for lithium-ion batteries. γ-V2O5 with oxygen vacancy mole fraction of 1.67% shows an open circuit voltage about 0.1 V lower than that of the perfect γ-V2O5. Oxygen vacancies generates gap states, which is beneficial to the electronic conductivity of γ-V2O5 and γ-LiV2O5. In addition, the activation energies for lithium-ion diffusion along [010] in both γ-V2O5 and γ-LiV2O5 are increased by oxygen vacancy, which might lead to the decrease of diffusion coefficient. Our results will provide guidance for further improving the lithium-ion storage performance of γ-V2O5. [ABSTRACT FROM AUTHOR]

In this paper, the effect of moisture on the charge behaviour in oil‐impregnated pressboard is analysed based on the characteristics of the interface and the bulk. Space charge behaviour and infrared spectra are acquired from a sample with a high moisture content of 1.92% and another with low moisture content of 0.13%. The results show that a greater number of hydrogen bonds form in the high‐moisture sample. The threshold fields of charge injection are 1 and 0.6 kV/mm in the low‐ and high‐moisture samples, respectively. The dynamic charge transport in bulk is significantly accelerated by moisture. The drop in the injection barrier at the interface and the accelerated transport of charge in bulk in the high‐moisture sample may be associated with the mediating effect of a water layer at the interface and the lower trap energy in bulk caused by the hydrogen bonds, respectively. The combined changes in the interface and the bulk led to the dominant position of negative charges inside the high‐moisture sample, regardless of the distribution area or the charge amount. [ABSTRACT FROM AUTHOR]

This study investigates the effect of moisture content on space charge characteristics based on the dynamic space charge response and conductivity characteristics of oilpaper insulation under a DC electric field. Moisture contents ranging from 0.34–2.89% are considered under an electric field of up to 20 kV/mm. The results show that homocharge accumulates inside the oil-paper insulator near both electrodes, with the amount of charge gradually increasing as the moisture content rises. It may be related to the decreased charge injection barrier at the electrode-sample interface as the moisture level increases. The conductivity increases with the rise in moisture level. However, as the conductivity increases, the corresponding space charge accumulation during polarization does not decrease, but increases significantly. This indicates that space charge accumulation may be related to both charge injection and conductivity. The electric field distortion inside the oil-paper insulator increases as the moisture content rises, with the maximum electric field distortion rate going from 16.9 to 92.9% at 5 kV/mm and from 29.7 to 62.5% at 20 kV/mm. [ABSTRACT FROM AUTHOR]

Droplet laden jet plays important roles in cutting-edge technologies including spray cooling, aerosol jet printing, pollution control, and cascade impactors. In this work, a numerical simulation scheme for jet flow is proposed. The turbulence is calculated based on the v 2 ¯ -f model and the droplets are described by the discrete phase model. The droplet-droplet collisions are calculated by a mesh-independent collision model. The results are compared with an experiment in which concentric dual-ring deposition patterns were observed on the impinging plate. The effects of the droplet volume fraction are investigated. Criteria for the necessity of two-way coupling as well as coalescence calculation are provided. This work provides a practical tool for aerosol impinging research and design. Copyright © 2020 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Several signal processing methods are introduced to improve the signal detected under periodic stress in terms of the signal-to-noise (S/N) ratio and behaviour in an arbitrary phase. In the filtering process for the averaging and fitting methods, it is assumed that the variation of space charge can be neglected for a given detecting phase. The averaging process is associated with the phase identification under periodic stress. The fitting process is shown to further enhance the S/N ratio based on space charge behaviour at different positions. A fitting model is chosen based on the signal characteristics, such as the dynamic response of the charge signal and the voltage waveform in the excitation source. The process is based on the premise that the space charge distribution can be detected without significant mutation near the interpolation phase. The procedure proposed optimises signal processing that is associated with space charge. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of nano-doping on partial discharge (PD) and electrical tree growth in cross-linked polyethylene (XLPE), samples of 0.5 wt% magnesium oxide MgO/XLPE were prepared and an AC experiment was carried out. A color-coded diagram for PD signal was developed to describe the PD activity during the whole process of treeing. The results show that the PD intensity in positive half cycle of voltage (PHC) is larger than that in negative half cycle of voltage (NHC), and the PD magnitude in MgO/XLPE is lower than that in XLPE. Moreover, the tree length and morphology in MgO/XLPE are similar to those in XLPE. Furthermore, a finite element simulation based on the bipolar charge transport model was applied to investigate the effect of space charge on PD under AC voltage. Simulation results suggest that the characteristics of PD and tree growth may be associated with the accumulated charge around the needle tip. The distribution of negative charges in NHC would be wider than that of positive charges in PHC, which would weaken the electric field in NHC and lead to the less PD in NHC. Moreover, the range of charge shield in MgO/XLPE may be larger and is equivalent to increasing the effective radius of curvature of needle tip, which would lead to smaller electric field and lower PD magnitude in MgO/XLPE. However, the addition of nano-MgO reduces the crystallinity of material based on the differential scanning calorimetry (DSC) result. Hence, although the PD magnitude in MgO/XLPE is lower, the MgO/XLPE researched in this paper does not show significant resistance to AC tree growth. [ABSTRACT FROM AUTHOR]

This study introduces silicone elastomers with micro and nano-sized boron nitride (BN) and silicon carbide (SiC) particles with various doping levels to improve thermal properties and partial discharge resistance. The effect of micro and nano-fillers on thermal conductivity, coefficient of thermal expansion (CTE), and thermal stability are investigated. Polarization and depolarization current and partial discharge are measured to investigate the non-linear conductivity, trap energy density distribution, and partial discharge resistance. Experimental results show higher thermal conductivity, lower CTE, and better thermal stability than the original silicone elastomer. Large size fillers dominate the thermal conductivity when the doping level is low, whereas the composite microstructure plays a significant role in the thermal conductivity when the doping level is high. The combination of different filler type and size has less effect on thermal stability and CTE compared to the effect of the doping level. According to the depolarization current, the composite's trap depth is generally shallower than that of the original silicone elastomer. With increased doping level, the shallow trap density increases, providing hopping sites for carriers, whereas the deep trap density decreases, reducing the number of trapped charges. The partial discharge inception voltage is higher than that of the original silicone elastomer, and it increases with the doping level, which may be because the electrostatic field generated by diffused charges reduces the local electric field near the high voltage electrode. [ABSTRACT FROM AUTHOR]

The charge transport characteristics of LDPE/SiO 2 nanocomposites were investigated by simultaneous measurement of space charge and relaxation current. The filling concentration of hydrophilic nano-SiO 2 ranged from 0.0 to 5.0 wt%. The effects of filling concentration on the relationship between charge accumulation and the quasi-steady current were analysed during the polarisation process. The trap energy distribution was calculated according to depolarisation current. For simplicity, a mean energy level is proposed through the overall averaging process in the detection period. Moreover, the total trap density within the measured energy level range was obtained by the integral of the energy distribution. The results show that the mean energy level and total trap density are non-monotonic with concentration. Based on the calculation results, the characteristics of charge accumulation and quasi-steady current were explained from the perspective of the trap energy distribution. Finally, a synchronous simulation of the space charge and relaxation current was carried out based on the above trap distribution parameters for pure LDPE and LDPE/SiO 2 nanocomposite with a concentration of 1.0 wt%. The simulation phenomena of charge accumulation characteristics and current decay trend were in close accordance with the experimental results, verifying the effectiveness of the analysis. [ABSTRACT FROM AUTHOR]

In this study, the electrical tree mechanisms during a growth period from tens of microns to hundreds of microns were investigated for cross‐linked polyethylene under a stepped DC voltage. The results show that the electrical tree grows along the direction of the needle tip pointing to the ground, and the tree growth follows a typical single branch type. The growth of the electrical tree is mainly detected during the voltage rising process and is rarely observed during the voltage maintenance step. Moreover, the length increment of the tree decreases with the increase in the length of the initial tree. The simulation results for the charge transport in the needle–plane electrode suggest that these growth characteristics are associated with the energy released near the needle tip during the charge trapping and detrapping processes. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is a common lung disease characterized by narrowed airways, resulting in serious breathing difficulty. Previous studies have demonstrated that inflammatory infiltration of leukocytes in the airway is associated with the pathogenesis of COPD. In the present study, we employed a microfluidic approach to assess the effect of COPD sputum on activated human peripheral blood T cell migration and chemotaxis under well‐controlled gradient conditions. Our results showed considerable basal migration of T cells derived from peripheral blood of COPD patients and healthy controls in the medium control groups. By contrast, the migration of T cells from COPD patients and healthy controls was significantly inhibited in the presence of a gradient of sputum supernatant from COPD patients. Furthermore, chemotaxis of T cells from COPD patients or healthy subjects toward an SDF‐1α gradient was clearly inhibited by sputum samples from the COPD patients. The inhibition effect revealed by the microfluidic cell migration experiments provides new information about the complex involvement of T cell trafficking in COPD. [ABSTRACT FROM AUTHOR]

This paper gives a detailed introduction of a simultaneous measurement system that can obtain the space charge distribution and the thermally stimulated current (TSC) of the same sample over the temperature range 213–373 K. This measurement system adopts a 4-electrode structure and a time sharing strategy to avoid the mutual interference between the space charge measurement and the current measurement. In addition, a space charge recovery method is proposed to obtain the real space charge distribution from the original data under varying temperature situation. Furthermore, a simultaneous measurement is performed on a cross-linked polyethylene (XLPE) sample. The experimental results show that the positive charges accumulate and dominate in the bulk during polarization and the cooling stages. During the thermal stimulation stage, the accumulated charges decay after ∼330 K, and the thermally stimulated current increases significantly after ∼330 K. The analysis results imply that the release of trapped charges may be the main cause of the thermally stimulated current, and most of the charges are trapped in traps more than 1 eV. [ABSTRACT FROM AUTHOR]

Abstract MYB proteins are major transcription factors that play significant roles in plant defenses against various stresses. However, available information regarding stress-related MYB genes in maize is minimal. Herein, a maize MYB gene, ZmMYB3R , was cloned and functionally characterized. Subcellular localisation analysis showed that ZmMYB3R is localised to the nucleus. Yeast one-hybrid results revealed that ZmMYB3R has trans-activation activity, and a minimal activation domain at the C-terminus spanning residues 217–563. Gene expression analysis suggested that ZmMYB3 R was induced by drought, salt and abscisic acid (ABA). Transgenic Arabidopsis plants overexpressing ZmMYB3R displayed enhanced growth performance and higher survival rates, elevated catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) enzyme activities, increased sensitivity to ABA, and regulation of the stomatal aperture, suggesting that ZmMYB3R enhances tolerance to drought and salt stress. qRT-PCR assays revealed elevated expression levels of stress/ABA genes in transgenic plants following stress treatments. Moreover, transgenic plants accumulated higher ABA content than wild-type plants under drought and salt stress conditions. Collectively, these results indicate that ZmMYB3R is a positive transcription factor that enhances tolerance to drought and salt stress via an ABA-dependent pathway. The findings may prove useful for engineering economically important crops. Highlights •. A novel maize MYB-3R gene was cloned and characterized. •. ZmMYB3R increases tolerance to drought and salt stress in transgenic plants. • ZmMYB3R is a positive transcription factor for stress responses. •. ZmMYB3R functions via an ABA-dependent pathway. [ABSTRACT FROM AUTHOR]

Abstract Cell-based assays including both cell identification assays and cell functional assays are broadly used in life science research and for medical applications. Traditionally, cell-based assays are performed in professional laboratories. Although such an approach is reliable, it significantly limits the accessibility of cell-based assays by many researchers without specialized cell imaging facilities and does not permit on-site use at most clinics. Over recent years, growing efforts have been made to overcome this limitation by developing various portable cell imaging platforms. Herein, we provide a timely review on the recent development of portable imaging systems and their biomedical applications. We describe the respective applications of three main classes of portable imaging technologies including miniaturized microscope, lens-free imaging device and smartphone-based microscope for cell-based assays. We conclude by discussing our views on the opportunities, problems and future directions of this emerging field. Graphical abstract fx1 Highlights • The recent development of portable imaging systems is reviewed. • Various cell-based assays enabled by portable imaging platforms are described. • The challenges, opportunities and future directions of this emerging field are discussed. [ABSTRACT FROM AUTHOR]

Chemotaxis plays a fundamental role in immune defense and cancer metastasis. Microfluidic devices are increasingly applied to studying chemotaxis, owing to their advantages of reduced reagent consumption, ability to control chemical gradients, tracking of individual cells, and quantification of chemotaxis. Many existing microfluidic chemotaxis devices suffer from limited throughput and complex operation. Here, we describe a microfluidic device with a radial channel design which allows for simultaneous chemotaxis tests of different cell types and different gradient conditions. This radial microfluidic device was capable of stand-alone stable gradient generation using passive pumping and pressure-balancing strategies. The device was validated by testing the migration of fast-migrating human neutrophils and two slower-migrating human breast cancer cell lines, MDA-MB-231 and MCF-7 cells. Furthermore, this radial microfluidic device was useful in studying the influence of the nuclear chromatin binding protein high mobility group A2 (HMGA2) on the migration of the human triple negative breast cancer cell line MDA-MB-231. [ABSTRACT FROM AUTHOR]

Among dissociation methods, negative electron transfer dissociation (NETD) has been proven the most useful for glycosaminoglycan (GAG) sequencing because it produces informative fragmentation, a low degree of sulfate losses, high sensitivity, and translatability to multiple instrument types. The challenge, however, is to distinguish positional sulfation. In particular, NETD has been reported to fail to differentiate 4-O- versus 6-O-sulfation in chondroitin sulfate decasaccharide. This raised the concern of whether NETD is able to differentiate the rare 3-O-sulfation from predominant 6-O-sulfation in heparan sulfate (HS) oligosaccharides. Here, we report that NETD generates highly informative spectra that differentiate sites of O-sulfation on glucosamine residues, enabling structural characterizations of synthetic HS isomers containing 3-O-sulfation. Further, lyase-resistant 3-O-sulfated tetrasaccharides from natural sources were successfully sequenced. Notably, for all of the oligosaccharides in this study, the successful sequencing is based on NETD tandem mass spectra of commonly observed deprotonated precursor ions without derivatization or metal cation adduction, simplifying the experimental workflow and data interpretation. These results demonstrate the potential of NETD as a sensitive analytical tool for detailed, high-throughput structural analysis of highly sulfated GAGs.Graphical Abstract [ABSTRACT FROM AUTHOR]

Ultra-lightweight foamed geopolymer (UFG) based on fly ash-metakaolin blends with its density of between 150 kg/m 3 and 300 kg/m 3 was successfully prepared by the mixed foaming method of chemical foaming. In the present study, the properties and characteristics of UFG were investigated by designing and optimizing the components of fly ash, metakaolin, alkaline activator, foam stabilizer and foaming agent (H 2 O 2 ), as well as the curing temperature. The results showed that foamed geopolymer with curing age of 7 days presented its dry density between 150 kg/m 3 and 300 kg/m 3 , the mean pore size between 0.57 mm and 1.13 mm, the porosity between 71.8% and 84.5%, the thermal conductivity between 0.0622 W/(m·K) and 0.0852 W/(m·K) and the compressive strength between 0.68 MPa and 2.23 MPa, showing better mechanical properties than the traditional portland cement foamed concrete with the same density. It is also found that curing temperature at 55 °C for 12 h seemed to substantially improve the compressive strength of UFG which is 1.91 MPa compared to curing at 25 °C for the same period of time. [ABSTRACT FROM AUTHOR]

M obile s ensing based on the integration of m icrofluidic device and s martphone, so-called MS 2 technology, has enabled many applications over recent years, and continues to stimulate growing interest in both research communities and industries. In particular, it has been envisioned that MS 2 technology can be developed for various cell functional assays to enable basic research and clinical applications. Toward this direction, in this paper, we describe the development of a MS 2 -based cell functional assay for testing cell migration (the M kit ). The system is constructed as an integrated test kit, which includes microfluidic chips, a smartphone-based imaging platform, the phone apps for image capturing and data analysis, and a set of reagent and accessories for performing the cell migration assay. We demonstrated that the M kit can effectively measure purified neutrophil and cancer cell chemotaxis. Furthermore, neutrophil chemotaxis can be tested from a drop of whole blood using the M kit with red blood cell (RBC) lysis. The effects of chemoattractant dose and gradient profile on neutrophil chemotaxis were also tested using the M kit . In addition to research applications, we demonstrated the effective use of the M kit for on-site test at the hospital and for testing clinical samples from chronic obstructive pulmonary disease patient. Thus, this developed M kit provides an easy and integrated experimental platform for cell migration related research and potential medical diagnostic applications. [ABSTRACT FROM AUTHOR]

To estimate arbitrary electron and hole trap energy distribution of cross-linked polyethylene (XLPE), a modified method based on the combination of relaxation current and space charge measurement is proposed. This method is on the premise that homocharges are injected at the shallow depth of dielectrics and then detrap and flow away from electrodes. During depolarization, space charge and relaxation current are measured simultaneously by a specialized pulsed electro-acoustic (PEA) equipment. Furthermore, the decrease rates of positive and negative space charge are separately calculated and the ratio between them are employed to differentiate the contribution of electrons and holes to relaxation current. Thus, the relaxation current can be divided into two components to calculate energy distribution of electron and hole traps. Besides, simulation based on a modified bipolar charge transport model with calculated energy distribution were performed to simulate the dynamics of space charge. The experiment results of XLPE show that more hole traps than electron traps exist at energy levels above 0.86 eV. The energy distribution corroborates the decay pattern of space charge. In addition, the simulation results show the same qualitative characters as experiment results. Therefore, this method could be employed to estimate arbitrary trap energy distribution and the simulation may help give an insight of trap properties as well as space charge dynamics. [ABSTRACT FROM AUTHOR]

In this study, a pulsed electroacoustic (PEA) system, which can measure the space charge distribution of polymer films from low to high temperatures, is introduced. The space charge behavior of direct current (DC) stressed low density polyethylene (LDPE) film is investigated at temperatures from −40 to 70 °C. The space charge results show that homocharges accumulate in the vicinity of electrodes at low temperatures (−40 to 0 °C), whereas heterocharges that appear during short circuit at the ambient temperature (30 °C), and negative charges gradually dominate the distribution with the increase of temperature. Moreover, the accumulated space charge density at −20 °C reaches the maximum within the investigated temperature range, which may be related to the traps formed by the polyethylene molecular chain branches. This finding coincides with the dynamic mechanical analysis (DMA) result and the thermally stimulated current (TSC) of LDPE reported by other researchers. Besides, the apparent mobilities of carriers at various temperatures calculated based on space charge decaying data indicates that the mobility decreases first and then increases with the increase of temperature from −40 to 70 °C. The variation of the apparent mobility can be explained by the hopping model. In addition, with the help of atomic force microscope (AFM) with Kelvin probe, the contact mode of aluminum/ LDPE/semiconductor was found to be the main reason that resulted in the slower decay of injected holes around the anode, as compared to the injected electrons around the cathode. [ABSTRACT FROM AUTHOR]

In a high voltage direct current (HVDC) transmission system, the devices like HVDC cable and its accessory, HVDC bush play important roles in power transmission and power transformation. The local electric field could be greatly enhanced due to the space charge accumulation in the insulation, which significantly influences the electrical performance of the electric devices. In this paper, an algorithm for solving the charge coupled systems of solid dielectrics is presented. The algorithm is based upon a finite element method (FEM) solving the Poisson equation and a finite volume method (FVM) discretizing the transportation equation on a cell-centered tessellation. Both FEM and FVM share a set of unstructured mesh. The study focuses on the capability of different upwind schemes on capture of charge density step. The numerical experiment results show that in contrast to conventional methods that constrain charge densities to piecewise constants within a cell, a higher-order approximation of charge density is obtained by reconstructing the charge densities gradient in the control volumes. And the oscillation could be avoided when a limiter function is adopted to make sure that no new extrema created between the central cell and the neighbor cells. The influences of time step, total calculation time, and the mesh structured or not are also investigated. The results show that the algorithm could provide enough accuracy when suitable time step and time duration are adopted with unstructured mesh. [ABSTRACT FROM PUBLISHER]

A modified method is proposed to directly determine the trap energy distribution in dielectrics after high electric field charge injection based on thermally stimulated current (TSC) measurement. Firstly, through a series of equation derivation, it is found that obtaining trap energy distribution from measured TSC data becomes solving a nonnegative least squares problem. Then, an iteration algorithm is introduced to solve the problem in detail. Finally, the modified method is applied to analyze TSC experiment results of polyethylene terephthalate (PET) film, which are compared with other researchers' work. The experiment results show that there is a wide apparent peak in TSC curves, extending from ?325 K to ?400 K. After analyzing with the method, the peak is composed of two components formed by released charges previously trapped in the traps of two major depths of ?1.09 eV and ?1.18 eV in the range of 0.5?1.3 eV. Altogether, these results generally agree with other researchers' analysis of PET, which acquired by various measurements and methods. Moreover, in order to check the reliability of the algorithm, R-square values are calculated. The values are close to 1 which manifests that the numerical solutions are almost coincide with experiment data and the method is proved to be trustworthy, realistic and stable. [ABSTRACT FROM PUBLISHER]

The simplest space charge measurement system is introduced for the direct space charge observation under arbitrary periodic stresses. An essential component of the system is the frequency allocation strategy for periodic stress fa and detection source fp. This strategy is based on the modified automatic equal phase shift (AEPS) principle, in which the relationship between fa and fp can be an integral multiple and a non-integral multiple. The phase detection in the range of 0??360? can be completed during Na cycles of periodic stress with Np detected excitation to realize phase resolution ?' = 2?/Np. Two different allocation strategies, namely, Na = 1 for the integral multiple between fa and fp and Na > 1 for the non-integral multiple between fa and fp, can be used to realize a high-phase resolution with consideration of the available frequency range for the detected source. Phase monitoring can be realized with the discrete voltage Va(i) of periodic stress at the detection phase and with the peak voltage Vg(i) of the raw signal representing the space charge density of the ground electrode. Phase delay is also introduced between the monitoring signal and real phase to avoid phase errors, especially at a high frequency and electric field. The detection phase of the space charge can be accurately identified through the monitoring signal via the data fitting or the Hilbert transform using the base wave component acquired with the Fourier transform. However, the data processing is complex for both methods. Thus, a simple and fast identification method is presented on the basis of the characteristic sequence of the AEPS principle. Finally, the feasibility and accuracy of the proposed system are successfully verified through the direct detection of the space charge within low-density polyethylene under several practical periodic stresses, namely, AC wave at 0.01 Hz, square wave at 1 kHz, and harmonic wave at 10 kHz. [ABSTRACT FROM AUTHOR]

The electrical properties of nanocomposites are closely related to their nanostructures. In order to investigate the nanostructures and space charge characteristics of magnesium oxide (MgO)/low-density polyethylene (LDPE), samples of LDPE with nano-MgO from 0.1 to 2.0 wt% are prepared, as well as pure LDPE. The nanostructures of nanocomposites are investigated by the technology of synchrotron radiation small-angle x-ray scattering (SAXS), and the space charge distributions in nanocomposites and LDPE are measured by the pulsed electro-acoustic (PEA) method. Results of the synchrotron radiation SAXS experiments reveal that there is obvious interphase between the nano-MgO particle and the LDPE matrix, the thickness of which increases along with the increase in nano-MgO concentration. The agglomeration and mass fractal exist in all nanocomposites, and become more obvious at higher concentration. Results of space charge measurements indicate that the apparent trap-controlled mobilities and the apparent trap depths are respectively larger and smaller than those in LDPE during the initial phase of depolarization when the concentrations are 0.1 and 0.5 wt%, and are respectively smaller and larger than those in LDPE when the concentrations are 1.0 and 2.0 wt%. The space charge amount decreases after the addition of nano-MgO. This is mainly due to the introduction of shallow traps which promote the charge recombination in 0.1 and 0.5 wt% MgO/LDPE nanocomposites, and the introduction of deep traps which restrict the charge transportation in 1.0 and 2.0 wt% MgO/LDPE nanocomposites. The space charge characteristics of MgO/LDPE nanocomposites are explained combined with the nanostructures obtained from the synchrotron radiation SAXS experiments. [ABSTRACT FROM AUTHOR]

In this paper, trap distribution variation in low density polyethylene (LDPE) after filled with 1 wt% nanosilica is investigated through the charge decay after corona charging with a needle-plane electrodes system. The LDPE and LDPE/SiO2 nanocomposite were firstly polarized under needle-plane electrodes system. The electrons and holes are injected through the variation of polarization of the needle. Then the surface space charge behavior and relaxation current were measured with a simultaneous measuring equipment, which overcomes the poor correlation of separate measurement. Lastly, the apparent mobility and trap distribution are evaluated based on the decay of surface space charge and relaxation current decay. It is found that the observed surface space charge and current are associated with trap distribution from 0.855 eV to 1.000 eV during decay process from 10 s to 3600 s. In LDPE/SiO2 nanocomposite, the estimated trap density of electrons and holes is more than that of LDPE in a relatively low energy range from 0.855 eV to 0.925 eV. These traps with low energy levels as transport media for carriers may be the main reason for the higher mobility of carriers in LDPE/SiO2 than LDPE, which is testified by surface space charge decay. It is also worth noting that according to the relaxation current decay, the estimated density of the relatively deep hole traps (>0.990 eV) is more than that of electron traps in LDPE, which is not observed in LDPE/SiO2. This is in accord with other scholar's molecular simulation result that most hole traps exist in intra-chain areas and electron traps exist in inter-chain areas, reflecting the different transportation characteristics of electrons and holes. [ABSTRACT FROM AUTHOR]

Multidrug and toxic compound extrusion (MATE) proteins are a group of secondary active transporters, which widely exist in all living organisms and play important role in the detoxication of endogenous secondary metabolites and exogenous agents. However, to date, no systematic and comprehensive study of this family is reported in maize. Here, a total of 49 MATE genes ( ZmMATE) were identified and divided into seven groups by phylogenetic analysis. Conserved intro-exon structures and motif compositions were investigated in these genes. Results by gene locations indicated that these genes were unevenly distributed among all 10 chromosomes. Tandem and segmental duplications appeared to contribute to the expansion and evolution of this gene family. The K / K ratios suggested that the ZmMATE has undergone large-scale purifying selection on the maize genome. Interspecies microsynteny analysis revealed that there were independent gene duplication events of 10 ZmMATE. In addition, most maize MATE genes exhibited different expression profiles in diverse tissues and developmental stages. Sixteen MATE genes were chosen for further quantitative real-time polymerase chain reaction analysis showed differential expression patterns in response to aluminum treatment. These results provide a useful clue for future studies on the identification of MATE genes and functional analysis of MATE proteins in maize. [ABSTRACT FROM AUTHOR]

Climate change is predicted to be a major threat to crop yield due to increasing global temperatures and periods of unpredictable rainfall. Therefore, it is important to identify some new genes that can help plants cope with drought stress. In this study, a drought-induced homeodomain-leucine zipper (HD-Zip) I gene, ZmHDZ4, was isolated from maize and characterized for its role in drought stress. Transient expression experiments showed that ZmHDZ4 is localized to the nucleus. Yeast one-hybrid assays demonstrated that ZmHDZ4 has trans-activation activity, and that the minimal activation domain was ZmHDZ4-1. We found that overexpression of ZmHDZ4 in rice can enhance tolerance to drought and increase sensitivity to abscisic acid (ABA). Compared to wild-type plants, ZmHDZ4-expressing transgenic plants had lower relative electrolyte leakage (REL), lower malondialdehyde (MDA) levels, and increased proline contents under drought stress conditions, all of which may contribute to enhanced drought tolerance. Taken together, these results suggest that ZmHDZ4 functions as a transcriptional regulator that can positively affect plant drought tolerance. Thus, ZmHDZ4 is an excellent candidate gene with potential applications in molecular breeding to improve crop drought tolerance. [ABSTRACT FROM AUTHOR]

An automatic equal phase shift principle (AEPS) is proposed to simplify space charge detection under periodic stress with the pulsed electroacoustic method. For pulse frequency, fp is a non-integral multiple with periodic stress frequency fa; the detecting phase can be automatically shifted with a certain value after each cycle of periodic stress. The pulse position will be at the same phase of periodic stress after several cycles. The minimum amounts of periodic stress cycles and pulse generated during this process are defined as Na (>1) and Np, respectively. They can be uniquely confirmed by the characteristic equation Na/fa = Np/fp. Moreover, the positions of pulse generated during this process are equally distributed in the periodic stress from 0o to 360° with a characteristic sequence of pulse. The phase interval, i.e. phase resolution Δ', is 2π divided by Np. Consequently, the phase resolution can be easily enhanced through an increase in the pulse amount Np by selection of fp, according to the characteristic equation. Finally, space charge behaviours in low-density polyethylene under 50 Hz AC stress were measured with three different pulse frequencies fp, i.e. 25.5, 1010 and 1001 Hz, to validate the proposed AEPS principle. Results show that the space charge distribution can be successfully acquired with a phase resolution from 7.07o to 0.36o, even if the pulse frequency is lower than the AC frequency at 25.5 Hz. This result indicates that AEPS can overcome the frequency limitation of the pulse generator, and a high phase resolution can be realised. [ABSTRACT FROM PUBLISHER]

Chronic Obstructive Pulmonary Disease (COPD) is a common lung disease characterized by breathing difficulty as a consequence of narrowed airways. Previous studies have shown that COPD is correlated with neutrophil infiltration into the airways through chemotactic migration. However, whether neutrophil chemotaxis can be used to characterize and diagnose COPD is not well established. In the present study, we developed a microfluidic platform for evaluating neutrophil chemotaxis to sputum samples from COPD patients. Our results show increased neutrophil chemotaxis to COPD sputum compared to control sputum from healthy individuals. The level of COPD sputum induced neutrophil chemotaxis was correlated with the patient’s spirometry data. The cell morphology of neutrophils in a COPD sputum gradient is similar to the morphology displayed by neutrophils exposed to an IL-8 gradient, but not a fMLP gradient. In competing gradients of COPD sputum and fMLP, neutrophils chemotaxis and cell morphology are dominated by fMLP. [ABSTRACT FROM AUTHOR]

A polysaccharide was purified from brown algaKjellmaniella crassifolia, and its precise structure was deduced on the basis of sequence analysis of oligosaccharide fragments obtained from mildly and strongly acidic hydrolysis of the polysaccharide. Electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS) was used to identify the structural features of the resultant oligosaccharides. The side chain oligosaccharides were composed of α-1,3-linked 4-O-sulfated fucose and α-1,3-linked 2,4-O-disulfated fucose, while the backbone oligosaccharides consisted of the disaccharide repeating unit of β-1,4-linked glucuronic acid and α-1,2-linked mannose. Thus, the fucoidan was determined to be a sulfated fuco-oligosaccharide branched glucuronomannan. [ABSTRACT FROM PUBLISHER]

T lymphocyte migration is crucial for adaptive immunity. Manipulation of signaling molecules controlling cell migration combined with in-vitro cell migration analysis provides a powerful research approach. Microfluidic devices, which can precisely configure chemoattractant gradients and allow quantitative single cell analysis, have been increasingly applied to cell migration and chemotaxis studies. However, there are a very limited number of published studies involving microfluidic migration analysis of genetically manipulated immune cells. In this study, we describe a simple microfluidic method for quantitative analysis of T cells expressing transfected chemokine receptors and other cell migration signaling probes. Using this method, we demonstrated chemotaxis of Jurkat transfectants expressing wild-type or C-terminus mutated CCR7 within a gradient of chemokine CCL19, and characterized the difference in transfectant migration mediated by wild-type and mutant CCR7. The EGFP-tagged CCR7 allows identification of CCR7-expressing transfectants in cell migration analysis and microscopy assessment of CCR7 dynamics. Collectively, our study demonstrated the effective use of the microfluidic method for studying CCR7 mediated T cell transfectant migration. We envision this developed method will provide a useful platform to functionally test various signaling mechanisms at the cell migration level. [ABSTRACT FROM AUTHOR]

Experimental studies on partial discharges (PD) occurred in oil-insulated devices using ultra-high frequency (UHF) sensors to detect PD signals and using wavelet analysis to process the acquired UHF signals are presented, and a threshold selecting method adapting to various noise circumstances when de-noising UHF signals using wavelet transform is proposed in this paper. The threshold method was based on numerical fitting of standard deviations and manual setting thresholds for brush-fire samples from a large scale. Horizontal comparisons between different geometries and vertical comparisons between different intensities of partial discharges in oil were also discussed and the mathematical tool was wavelet analysis. Multi-resolution analysis (MRA) results show the significant differences that can be used to recognize the discharge pattern and to judge the intensity. Particularly attention was given to needle-plate discharge geometry, which was often used by researchers focusing on the mechanism of pre-breakdown phenomena in liquid dielectrics. The results of needle-plate model show good agreement with electronic theory of liquid pre-breakdown mechanism. [ABSTRACT FROM AUTHOR]

This paper presented the measurement results of space charge distribution and high field conduction in cross-linked polyethylene (XLPE) plate sample at various electric fields for a broad temperature range from 30 to 90 °C. The temperature effect on charge trapping and transport mechanism is discussed based on estimation of threshold characteristic and apparent mobility. It is shown that the threshold field for space charge accumulation apparently decreased with the temperature, probably associated with acceleration of charge injection and ionic dissociation. The apparent mobility of charges showed an exponential dependence on temperature, which indicates enhancement of charge detrapping and transfer rate at higher temperature. The field dependence of the space charge decreases with the temperature, results in more space charge accumulate at room temperature than at high temperature at certain high field. This behavior indicates that the space charge formation rate increases slower than the charge detrapping rate as the temperature increases. Besides, negative charge is always dominant in the sample at the measuring field and temperature range. This is probably due to stronger electron injection at XLPE-aluminum interface or more negative ion formed by dissociation of chemical species. [ABSTRACT FROM AUTHOR]

[Display omitted] • ORR performance depended on the synergic transfer of molecules and electrons. • Ordered matrix and disordered edge regulate electrons and molecules transfer. • C = O functional groups enhanced the transfer of oxygen molecules. • Sparse pyridine-N regulated the transfer of interface electron. • Pyridine-N/C = O groups collaborated to improve the selectivity of 2e-ORR. In situ hydrogen peroxide (H 2 O 2) production by two-electron oxygen reduction reaction (2e-ORR) is limited by sluggish dynamics which are divided into molecule transfer and reaction kinetics. Ordered matrix and disordered edge is synthesized to regulate molecules and electrons transfer. Interface Atomic Domains (IAD) are used to regulate the dynamics of 2e-ORR, which are a local chemical environment composed of C/N/O atoms (C-N, C = O). IAD are synthesized by biomass tar through pyrolysis, oxidation and doping. Sparse pyridine-N are constructed by the formation of C = O groups and the placeholder of pyrrole-N. Results indicate that surface pyridine-N improves interface electrons transfer, while sparse pyridine-N increases 2e-ORR selectivity. Meanwhile, the surface C = O groups provide strong chemical adsorption for O 2 molecules. The collaboration of pyridine-N/C = O groups realized the high activity and selectivity of 2e-ORR. As a result, the synthetic material with N, O-functional groups possesses over 90% selectivity for 2e-ORR during a wide potential range. [ABSTRACT FROM AUTHOR]

The development of photocatalysts with efficient hydrogen evolution activity has been the goal for sustainable hydrogen production. In this work, heterojunction composite photocatalyst is formed by hydrothermal coupling of ZnO and Mn 0.2 Cd 0.8 S. Compared with pure ZnO and Mn 0.2 Cd 0.8 S, the composite photocatalyst has the ability to provide more abundant active sites and better photogenerated carriers separation efficiency. The optimized composite photocatalyst shows a 9.36-fold increase in hydrogen evolution activity (4297.99 μmol g−1 h−1) compared to Mn 0.2 Cd 0.8 S (459.31 μmol g−1 h−1) and exhibits excellent cycling stability. Density functional theory calculations identifies Type-II charge transfer path in the composite photocatalyst, achieving effective separation in space of photogenerated electrons from holes and suppressing recombination within the semiconductor. The results show that the construction of Type-II heterojunction in this work achieves a significant enhancement of the hydrogen evolution activity of the photocatalyst by constructing carrier transport channels at the contact interface of the heterojunction. [Display omitted] • Novel and low-cost Mn 0.2 Cd 0.8 S@ZnO structured photocatalyst is prepared by thermal coupling. • Construction of Type-II heterojunction enables efficient separation of photogenerated carriers. • More abundant active sites are exposed on the surface of Mn 0.2 Cd 0.8 S@ZnO. • Composite photocatalysts exhibit significantly enhanced photocatalytic activity and stability. [ABSTRACT FROM AUTHOR]

SEC6 and KEULE interact directly, and may coordinate cytokinesis in Arabidopsis thaliana. The interaction may serve as a novel molecular linkage between arriving vesicles and membrane fusion machinery or directly regulate membrane fusion during cell plate formation in plants.Proper vesicle tethering and membrane fusion at the cell plate are essential for cytokinesis. Both the vesicle tethering complex exocyst and membrane fusion regulator KEULE were shown to function in cell plate formation, but the exact mechanisms still remain to be explored. In this study, using yeast two-hybrid (Y-2-H) assay, we found that SEC6 interacted with KEULE, and that a small portion of C-terminal region of KEULE was required for the interaction. The direct SEC6–KEULE interaction was supported by further studies using in vitro pull-down assay, immunoprecipitation, and in vivo bimolecular florescence complementation (BIFC) microscopy. sec6 mutants were male gametophytic lethal as reported; however, pollen-rescued sec6 mutants (PRsec6) displayed cytokinesis defects in the embryonic cells and later in the leaf pavement cells and the guard cells. SEC6 and KEULE proteins were co-localized to the cell plate during cytokinesis in transgenic Arabidopsis. Furthermore, only SEC6 but not other exocyst subunits located in the cell plate interacted with KEULE in vitro. These results demonstrated that, like KEULE, SEC6 plays a physiological role in cytokinesis, and the SEC6–KEULE interaction may serve as a novel molecular linkage between arriving vesicles and membrane fusion machinery or directly regulate membrane fusion during cell plate formation in plants. [ABSTRACT FROM AUTHOR]

• Broaden the application of Ti3C2Tx (MXene) in the electromagnetic wave absorption field. • Provides a new means of developing high-performance MXene absorbers with adjustable conductivity and dielectric loss. • Optimized the impedance matching properties by loading highly defective TiO2 onto a Ti3C2Tx (MXene) sheet with S-doping and high-temperature annealing treatment. Ti 3 C 2 T x (MXene) materials with multilayered structures have been widely developed in various academic fields. However, the application of electromagnetic wave (EMW) absorption is limited because of the high conductivity, which leads to impedance mismatch. Herein, the impedance-matching properties were optimized by loading highly defective TiO 2 onto an MXene sheet with S-doping and high-temperature annealing treatment. This treatment enhanced the EMW absorption because of the synergistic effect between the appropriate conductivity and enhanced polarization. The results show that S-doped MXene-300 has a conductivity of 2.70 × 10–5 S/cm and exhibits the best area of impedance matching among the investigated samples. When the as-prepared S-doped MXene-300 quality ratio with paraffin was 1:1, the minimum reflection loss could reach −44.91 dB with a 4 mm coating thickness. In addition, the widest effective absorption (reflection loss ≤–10 dB) frequency bandwidth was 5.88 GHz when the thickness was 2.5 mm, which indicated that the dipolar polarization is the main positive EMW attenuation pathway for the S-doped MXene absorber. This research provides a new means of developing high-performance MXene EMW absorbers with adjustable conductivity and dielectric loss. [ABSTRACT FROM AUTHOR]

Microfluidic devices can better control cellular microenvironments compared to conventional cell migration assays. Over the past few years, microfluidics-based chemotaxis studies showed a rapid growth. New strategies were developed to explore cell migration in manipulated chemical gradients. In addition to expanding the use of microfluidic devices for a broader range of cell types, microfluidic devices were used to study cell migration and chemotaxis in complex environments. Furthermore, high-throughput microfluidic chemotaxis devices and integrated microfluidic chemotaxis systems were developed for medical and commercial applications. In this article, we review recent developments in microfluidics-based chemotaxis studies and discuss the new trends in this field observed over the past few years. [ABSTRACT FROM AUTHOR]

Abstract: Utilizing experimental methods, we have identified that the phase transition of WO3 from edge-sharing into corner-sharing can largely decrease the bleaching velocity during hydrogen sensing cycles. This phase transition was successfully prevented by the addition of silica and the gas sensing cycles of WO3/SiO2 film have been undertaken more than 500 times without any obvious property attenuation. The first principles calculations suggest a tendency of WO3 from clusters into cross-link network. During this process, the HOMO–LUMO gap of WO3 decreases as well as the hydrogen atom desorption energy, which indicates a decay of the bleaching velocity. [Copyright &y& Elsevier]

In the process of photocatalysis, semiconductor materials generate photogenerated electrons and photogenerated holes when excited by sunlight, so as to participate in the process of photocatalytic decomposition of water to produce hydrogen. In this work, under the combined action of ultrasonic and electrostatic forces, two semiconductors are successfully coupled through electrostatic self-assembly to effectively avoid the serious phenomenon of sulfide photocorrosion. Through electrochemical and fluorescence characterization experiments, it is confirmed that ZnCo2O4/CdS can accelerate the generation and transmission rates of photogenerated carriers. ZnCo2O4/CdS greatly increased the activity of the catalyst under simulated sunlight irradiation. With good photocatalytic activity, the hydrogen yield reached 80.71 mmol g−1 within 5 hours, far superior to those of Co3O4/CdS and ZnO/CdS. The relative values of the work functions of ZnCo2O4(311) and CdS(110) were calculated by DFT. Combined with the position of the conduction band, it was concluded that a new S-scheme induced by an internal electric field was formed at the ZCO/CS-25% contact interface, thus improving the photocatalytic activity. [ABSTRACT FROM AUTHOR]