Surface activity of cancer cells:The fusion of two cell aggregates

A key feature that distinguishes cancer cells from all other cells is their capability to spread throughout the body.Although how cancer cells collectively migrate by following molecular rules which influence the state of cell-cell adhesion contacts has been comprehensively formulated,the impact of physical interactions on cell spreading remains less understood.Cumulative effects of physical interactions exist as the interplay between various physical parameters such as(1)tissue surface tension,(2)viscoelasticity caused by collective cell migration,and(3)solid stress accumulated in the cell aggregate core region.This review aims to point out the role of these physical parameters in cancer cell spreading by considering and comparing the rearrangement of various mono-cultured cancer and epithelial model systems such as the fusion of two cell aggregates.While epithelial cells undergo volumetric cell rearrangement driven by the tissue surface tension,which directs cell movement from the surface to the core region of two-aggregate systems,cancer cells rather perform surface cell rearrangement.Cancer cells migrate toward the surface of the two-aggregate system driven by the solid stress while the surface tension is significantly reduced.The solid stress,accumulated in the core region of the two-aggregate system,is capable of suppressing the movement of epithelial cells that can undergo the jamming state transition;however,this stress enhances the movement of cancer cells.We have focused here on the multi-scale rheological modeling approaches that aimed at reproducing and understanding these biological systems.

Outage Behaviors of Active Intelligent Reflecting Surface Enabled NOMA Communications

Active intelligent reflecting surface(IRS)is a novel and promising technology that is able to overcome the multiplicative fading introduced by passive IRS.In this paper,we consider the application of active IRS to nonorthogonalmultiple access(NOMA)networks,where the incident signals are amplified actively through integrating amplifier to reflecting elements.More specifically,the performance of active/passive IRS-NOMA networks is investigated over large and small-scale fading channels.Aiming to characterize the performance of active IRSNOMA networks,the exact and asymptotic expressions of outage probability for a couple of users,i.e.,near-end user n and far-end user m are derived by exploiting a 1-bit coding scheme.Based on approximated analyses,the diversity orders of user n and user m are obtained for active IRS-NOMA.In addition,the system throughput of active IRS-NOMA is discussed in the delay-sensitive transmission.The simulation results are carried out to verify that:i)The outage behaviors of active IRS-NOMAnetworks are superior to that of passive IRS-NOMAnetworks;ii)As the reflection amplitude factors increase,the active IRS-NOMAnetworks are capable of furnishing the enhanced outage performance;and iii)The active IRS-NOMA has a larger system throughput than passive IRS-NOMA and conventional communications.

Sum-Rate Maximization in Active RIS-Assisted Multi-Antenna WPCN

In this paper,we propose an active reconfigurable intelligent surface(RIS)enabled hybrid relaying scheme for a multi-antenna wireless powered communication network(WPCN),where the active RIS is employed to assist both wireless energy transfer(WET)from the power station(PS)to energyconstrained users and wireless information transmission(WIT)from users to the receiving station(RS).For further performance enhancement,we propose to employ both transmit beamforming at the PS and receive beamforming at the RS.We formulate a sumrate maximization problem by jointly optimizing the RIS phase shifts and amplitude reflection coefficients for both the WET and the WIT,transmit and receive beamforming vectors,and network resource allocation.To solve this non-convex problem,we propose an efficient alternating optimization algorithm with the linear minimum mean squared error criterion,semidefinite relaxation(SDR)and successive convex approximation techniques.Specifically,the tightness of applying the SDR is proved.Simulation results demonstrate that our proposed scheme with 10 reflecting elements(REs)and 4 antennas can achieve 17.78%and 415.48%performance gains compared to the single-antenna scheme with 10 REs and passive RIS scheme with 100 REs,respectively.

YAG laser welding with surface activating flux

YAG laser welding with surface activating flux has been investigated, and the influencing factors and mechanism are discussed. The results show that both surface activating flux and surface active element S have fantastic effects on the YAG laser weld shape, that is to obviously increase the weld penetration and D/W ratio in various welding conditions. The mechanism is thought to be the change of weld pool surface tension temperature coefficient, thus, the change of fluid flow pattern in weld pool due to the flux.

Highly reversible lead-carbon battery anode with lead grafting on thecarbon surface

A novel C/Pb composite has been successfully prepared by electmless plating to reduce the hydrogenevolution and achieve the high reversibility of the anode of lead-carbon battery （LCB）. The depositedlead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Becauselead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogenevolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead.Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge-discharge reversibility, which is attributed to the good connection between carbon additives and leadthat has been stuck on the surface of C/Pb composite during the preparation process. The addition of CIPb composite maintains a solid anode structure with high specific surface area and power volume, andthereby, it plays a significant role in the highly reversible lead-carbon anode.

Novel Zwitterionic Surfactants: Synthesis and Surface Active Properties of N-(3-Alkoxy-2-Hydroxypropyl)-N, N-Dimethyl glycine Betaines

Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)-C-13. Surface tension experiments showed that these surfactants have higher surface activity than those without hydroxypropyl group. The values of CMC and gamma(CMC) of these surfactants have been determined.

The surface activation of boron to improve ignition and combustion characteristic

Boron is a very promising and highly attractive fuel because of high calorific value. However, the practical applications in explosives and propellants of boron have been limited by long ignition delay time and low combustion efficiency. Herein, nano-Al and graphene fluoride(GF) as surface activated materials are employed to coat boron(B) particles to improve ignition and combustion performance. The reaction heat of nano-Al coated B/KNO_(3)and GF coated B/KNO_(3)are 1116.83 J/g and 862.69 J/g, respectively, which are higher than that of pure B/KNO_(3)(823.39 J/g). The ignition delay time of B/KNO_(3)could be reduced through nano-Al coating. The shortest ignition delay time is only 75 ms for B coated with nano-Al of 8 wt%, which is much shorter than that of pure B/KNO_(3)(109 ms). However, the ignition delay time of B/KNOcoated with GF has been increased from 109 to 187 ms. B coated with GF and nano-Al shown significantly influence on the pressure output and flame structure of B/KNO_(3). Furthermore, the effects of B/O ratios on the pressure output and ignition delay time have been further fully studied. For B/KNO_(3)coated with nano-Al and GF, the highest pressures are 88 KPa and 59 KPa for B/O ratio of 4:6, and the minimum ignition delay time are 94 ms and 148 ms for B/O ratio of 7:3. Based on the above results, the reaction process of boron coated with GF and nano-Al has been proposed to understand combustion mechanism.

Effect of Anion Surface Active Agent on the Preparation of SrTiO_3 Nano-Crystals

SrTiO_3 nano-crystal samples with floccule or flake crystal morphology,which were indexed as a perovskite-type crystal structure based on the results of XRD and TEM,were successfully prepared by one-step liquid reaction method.And the growth mechanism of the SrTiO_3 nano-crystals under the liquid condition with/without adding the surface active agent was investigated.It was found that adding the surface active agent contributes to the processing in which the ions gathering bodies transit to a more stable phase through the chemical reaction and form the flake SrTiO_3 nano-crystals.

Magnetic Properties and Surface Activity Sites of Pt-Dy/γ-Al_2O_3 Catalysts

The magnetism and surface behaviour of Pt-Dy/γ-Al_2O_3 catalysts were studied respectively by means of a Faraday magnetic balance and the method of carbon disulfide.The ferromagnetic impurity in the support,γ-Al_2O_3,at low temperature was corrected for the first time.The magnetic susceptibilities of the cat- alysts follow the sequence in different stage of preparation:χ_(uncalcined)<χ_(calcined)<χ_(reduced). The magnetic susceptibilities of the catalysts decrease as they adsorb hydrogen,cyclohexane or benzene. There is a correlation between the aromatization yield of cyclohexane or heptane on these catalysts and the magnetic susceptibility of the catalysts.Since addition of Dy increases the number of adsorption sites and the relevant proportions of weak adsorption sites,the abilities of sulfur-resistance and cyclohexane dehydrogenation are improved.In Pt-Dy/γ-A:_2O_3 catalysts,Dy improves the aromatization activity and stability of the catalyst and plays the role of the electron promoter.

STUDIES ON THE SURFACE MODIFICATION OF ANHYDRITE

The lack of the early phase gelation property has limited the application of anhydrite as building material products. The use of additives, however, activates the anhydrite surfaces and results in the occurrence of early phase gelation. Under different surface modification conditions,the solubility of anhydrite in water has been measured and it has indicated a correlation between the anhydrite surface activity and its solubility in water. This relationship can be utilized to further study the anhydrite surface activation.

Surface Activation of Plane and Curved Automotive Polymer Surfaces by Using a Fittable Multi-Pin DBD Plasma Source

In this work, surface activation of automotive polymers using atmospheric pressure plasmas was investigated. The aim was to increase the polar fraction of the surface energy of both plane and convex polymer devices with a radius in the range of 30 mm. For this purpose, a fittable low temperature atmospheric pressure plasma source based on capacitively coupled multi-pin electrodes was set up and applied. Each single electrode generates a treatment spot of approximately 2 cm2 with a tunable power density of up to 1.4 W/cm2. The surface energy was evaluated by contact angle measurements. After treatment at a low energy density of 1.01 J/cm2, the polar fraction of the surface energy of the investigated polymers was increased by a factor of 3.3 to 132, depending on the polymer materials. It was shown that by applying the presented fittable plasma source, this effect is independent of the surface radius of the polymer sample.

Mechanical and histological properties of an electrospun scaffold with a modified surface by plasma polymerization implanted in an in vivo model

This article presents the construction of scaffolds composed of polylactic acid(PLA)with different concentrations of hydroxyapatite(HA)by electrospinning,which were superficially modified with polypyrrole(PPy/I)by plasma polymerization.A preliminary study was conducted of the biological and mechanical behavior of the scaffolds when they were implanted in the back of rabbits for 30 days;bone cells differentiated from mesenchymal stem cells(MSCs)were used.The bone cell and scaffold structures were characterized by histological,immunohistochemical,and mechanical stress tests.Hematoxylin–eosin staining showed good tissue conformation.The immunohistochemical tests highlighted the presence of the main bone tissue proteins,such as collagen,osteocalcin,and osteopontin.The PLA/HA scaffolds were observed to exhibit cell adhesion and proliferation properties;however,the response was much better in the scaffolds that had a higher concentration of HA and that were coated with PPy/I.The results of the mechanical tests of the scaffolds indicated that the plasma treatment improved the adhesion and cell proliferation properties and contributed to the mechanical support,allowing the formation of neotissues with good viability of cell growth.

SYNIHESIS AND SURFACE ACTIVE PROPERTIES OF OXYETHYLENATED FATTY ALCOHOL 2-HYDROXYPROPYL SULFONATES

Synthesis and surface active properties of the oxyethylenated fatty alcohol 2-hydroxypropyl sulfonates were investigated.Of all surface active compounds studied,those with a 2-hydroxypropyl (HP) moiety in the molecule are more surface-active than the corresponding compounds without it.

Ab Initio Potential Surface in CH_4 Activation by PTCL_2

Ab initio potential surface of oxidative addition of CH4 to coordinatively unsaturated PtC12 is presented. The electron correlation has a big effect on the transition state and activation energy.

Design of double-layer active frequency-selective surface with PIN diodes for stealth radome

An experimental double-layer active frequency-selective surface（AFSS） for stealth radome is proposed. The AFSS is a planar structure which is composed of a fixed frequency-selective surface（FSS）, a PIN diodes array, and a DC bias network. The AFSS elements incorporating switchable PIN diodes are discussed. By means of controlling the DC bias network, it is possible to switch the frequency response for reflecting and transmitting. Measured and simulated data validate that when the incidence angle varies from 0°to 30° the AFSS produces more than-11.5 dB isolation across6–18 GHz when forward biased. The insertion loss（IL） is less than 0.5 dB across 10–11 GHz when reverse biased.

A MOLECULAR BEAM INVESTIGATION ON ACTIVATED CHEMISORPTION OF N_2 ON Ni SURFACE AND La FILM

The activated chemisorption of N2 on Ni （poly） and La film was performed on a molecular beam—surface scattering apparatus. Experimental results indicate that the initial sticking probability so increases linearly from 0 to 0.03 as normal component of translational energy of the molecuar beam En increases from 11.00 to 19.91 kcal/mol for N2/Ni system and S0 from 0 to 0. 10 as En from 10. 40 to 19.91 kcal/mol for N2/La system. The apparent activation energy △E are 6.16 kcal/mol and 5.30 kcal/mol for N2/Ni and N2/La systems respectively.

Experimental Study on the Dependency of Ice Nucleation Active Surface Site Density on ATD Aerosol Size

In light of the percentage of Earth’s cloud coverage, heterogeneous ice nucleation in clouds is the most important global-scale pathway. More recent parameterizations of ice nucleation processes in the atmosphere are based on the concept of ice nucleation active surface site density (ns). It is usually assumed that ns is independent of time and aerosol size distribution, i.e. that the surface properties of aerosols of the same species do not vary with size. However, the independence of ns on aerosol size for every species has been questioned. This study presents the results of ice nucleation processes of ATD laboratory-generated aerosol (particle diameters of 0 - 3 μm). Ice nucleation in the condensation mode was performed in a Dynamic Filter Processing Cham- ber at temperatures of -18°C and -22°C, with a saturation ratio with respect to water of 1.02. Results show that ns increased by lowering the nucleation temperature, and was also dependent on the particle size. The ns of particles collected on the filters, after a 0.5 μm D50 cut-off cyclone, resulted statistically higher with respect to the values obtained from the particles collected on total filters. The results obtained suggest the need for further investigation of ns dependence of same composition aerosol particles with a view to support weather and climate predictions.

A Comparative Investigation of Single Crystal and Polycrystalline Ni-Rich NCMs as Cathodes for Lithium-Ion Batteries

Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs suffer from poor cycle stability,limiting its further application.Herein,single crystal and polycrystalline LiNi_(0.84)Co_(0.07)Mn_(0.09)O_(2)cathode materials are compared to figure out the relation of the morphology and the electrochemical storage performance.According to the Li^(+)diffusion coefficient,the lower capacity of single crystal samples is mainly ascribed to the limited Li+diffusion in the large bulk.In situ XRD illustrates that the polycrystalline and single crystal NCMs show a virtually identical manner and magnitude in lattice contraction and expansion during cycling.Also,the electrochemically active surface area(ECSA)measurement is employed in lithium-ion battery study for the first time,and these two cathodes show huge discrepancy in the ECSA after the initial cycle.These results suggest that the single crystal sample exhibits reduced cracking,surface side reaction,and Ni/Li mixing but suffers the lower Li^(+)diffusion kinetics.This work offers a view of how the morphology of Ni-rich NCM effects the electrochemical performance,which is instructive for developing a promising strategy to achieve good rate performance and excellent cycling stability.

New Nano Polymer Materials for Composite Exterior-Wall Coatings

A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine(TETA).Then triethyltetramine(TETA)was injected dropwise into a pro-pylene glycol methyl ether(PM)solution for chain extension reaction.A hydrophilic andflexible polyether seg-ment was introduced into the hardener molecule.The effects of TETA/DGEPG,reaction temperature and reaction time on the epoxy conversion of polyethylene glycol diglycidyl ether(DGEPG)were studied.In addition,several alternate strategies to add epoxy resin to the high-speed dispersion machine and synthesize MEA DGEBA adduct(without catalyst and with bisphenol A diglycidyl ether epoxy resin)were compared.It was found that the higher the molecular weight of triethylenetetramine,the longer the chain segment of the surface active molecule.When the equivalence ratio of amine hydrogen and epoxy group is low,the stability of lotion is good.When the ratio of amine hydrogen to epoxy group is large,the content of triethylenetetramine is small.The main objective of this study is the provision of new data and knowledge for the development of new materials in the coating and electronic industry.