Suspended State Research Articles

Loss of inter-cellular cooperation by complete epithelial-mesenchymal transition supports favorable outcomes in basal breast cancer patients.

According to the sequential metastasis model, aggressive mesenchymal (M) metastasis-initiating cells (MICs) are generated by an epithelial-mesenchymal transition (EMT) which eventually is reversed by a mesenchymal-epithelial transition (MET) and outgrowth of life-threatening epithelial (E) macrometastases. Paradoxically, in breast cancer M signatures are linked with more favorable outcomes than E signatures, and M cells are often dispensable for metastasis in mouse models. Here we present evidence at the cellular and patient level for the cooperation metastasis model, according to which E cells are MICs, while M cells merely support E cell persistence through cooperation. We tracked the fates of co-cultured E and M clones and of fluorescent CDH1-promoter-driven cell lines reporting the E state derived from basal breast cancer HMLER cells. Cells were placed in suspension state and allowed to reattach and select an EMT cell fate. Flow cytometry, single cell and bulk gene expression analyses revealed that only pre-existing E cells generated E cells, mixed E/M populations, or stem-like hybrid E/M cells after suspension and that complete EMT manifest in M clones and CDH1-negative reporter cells resulted in loss of cell plasticity, suggesting full transdifferentiation. Mechanistically, E-M coculture experiments supported the persistence of pre-existing E cells where M cells inhibited EMT of E cells in a mutual cooperation via direct cell-cell contact. Consistently, M signatures were associated with more favorable patient outcomes compared to E signatures in breast cancer, specifically in basal breast cancer patients. These findings suggest a potential benefit of complete EMT for basal breast cancer patients.

Establishment and characterization of cell clones from the Papilio cell line RIRI-PaDe-3 by a high-efficiency clonal method.

Cell cloning is of great importance in keeping particular properties of cultured cells, and interesting cells can be selected by cloning from heterogeneous cell populations. In addition, continuous cell lines usually from primary culture are prone to heterologous constitution and genetic instability, so that supplementary cloning steps are necessary for achieving a homogenous cell population. In this study, limiting dilution culture and feeder layer culture were originally used for cloning RIRI-PaDe-3 cell line, but both failed. Afterward, we designed a cloning protocol which was composed of two steps: cells in semisolid medium with seeding density in the range of 3.05 × 105-6.10 × 105cells/mL formed colonies from monodispersed cell suspensions; 40 well-dispersed colonies were removed from the suspended state by using micromanipulator system and finally scaled up. To determine whether this method can isolate cell lines possessing characteristics different from the parent population, we made an evaluation of cells monoclonal in biological characteristics. Significant differences have been found among clones isolated from the RIRI-PaDe-3 insect cell line in cell morphology, chromosome numbers, and genetic background. Thus the indicated modified semisolid medium cloning protocol was advantageous to the convenient and genuine cloning from the previously heterogeneous population.

Історія розвитку поліграфа в Україні: Науково-дослідний інженерний центр "Пульс" - перша в Україні наукова установа, яка займалася розробкою вітчизняних поліграфів у 2000-х роках

In July 2018, 10 years have passed since the liquidation of the first state scientific institution in Ukraine, which was professionally engaged in the development of domestic single-channel polygraphs for their mobile use in practical activities. Thus, by Resolution No. 320 of the Cabinet of Ministers of Ukraine dated May 5, 1995, the state institution "Research and Engineering Center "Pulse" was established in Ukraine, which was part of the Military Medical Department of the Security Service of Ukraine, with the class (type) of professional activity. Research and development in the field of natural and technical sciences" (KVED-2005: 73.10.0). Legal address: 01021, Kyiv, Pecherskyi district, Lypska street, 11. During 2001 - 2008, the Center was engaged in the development and implementation of registration devices emotional tension of a person - "lie detectors" of domestic production of the "Vector" series models - "Vector 01.1", "Vector 02.1", mock-up sample "Vector 14", as well as methodical support for scientific developments and introduction into professional activity of single-channel devices - "Vector 01.1 ", "Vector 02.1". Of the specified devices, the "Vector 14" model was produced in a single copy as an experimental, mock-up sample, which consisted of an open board of circuit elements and provided for the possibility of recording the research protocol and was supposed to become the first full-fledged Ukrainian multi-channel polygraph, however, in did not receive a connection with the suspended state funding for further development.

OPTIMISATION OF AUTOMATIC DOSED MOULD FILLING WITH FERROMAGNETIC POWDERS

The effectiveness of the technique for automatic dosed mould filling with fine ferromagnetic powders without natural fluidity is experimentally proved in the paper. In order to obtain steady powder fluidity, disperse medium in the hopper of the considered device is affected by variable 50 Hz gradient magnetic field with vertical induction lines and higher gradient in the area of stimulated fluidity formation and constant magnetic field with horizontal induction lines. At certain magnetic fields parameters, disperse medium passes to a dynamically steady suspended state thus forming a magnetic fluidized bed, and powder flows into a dispenser. The paper provides the results obtained in experimental studies of constant magnetic field induction and variable magnetic field gradient influence on the mass flowrate of barium ferrite powders with an average particle size dav of 1 μm and strontium ferrite powders with dav = 1, 9 and 50 μm through a 2 mm hole. Presented experimental dependencies show that for dav = 1 μm barium and strontium ferrite powders the speeds of powder transportation to the dispenser reach their maximum values at a constant magnetic field induction of 15,7 mT and a variable magnetic field induction gradient of 593 mT/m and are equal to 96,9 and 181,1 mg/s, respectively. According to experimental data, the minimal relative mass error of dav = 1 μm strontium ferrite powder flowed in the dispenser is observed at electromagnetic effect modes providing maximal disperse material fluidity and equals to 2,1–2,3 %.

Effect of ac electric field on the dynamics of a vesicle under shear flow in the small deformation regime.

Vesicles or biological cells under simultaneous shear and electric field can be encountered in dielectrophoretic devices or designs used for continuous flow electrofusion or electroporation. In this work, the dynamics of a vesicle subjected to simultaneous shear and uniform alternating current (ac) electric field is investigated in the small deformation limit. The coupled equations for vesicle orientation and shape evolution are derived theoretically, and the resulting nonlinear equations are handled numerically to generate relevant phase diagrams that demonstrate the effect of electrical parameters on the different dynamical regimes such as tank treading (TT), vacillating breathing (VB) [called trembling (TR) in this work], and tumbling (TU). It is found that while the electric Mason number (Mn), which represents the relative strength of the electrical forces to the shear forces, promotes the TT regime, the response itself is found to be sensitive to the applied frequency as well as the conductivity ratio. While higher outer conductivity promotes orientation along the flow axis, orientation along the electric field is favored when the inner conductivity is higher. Similarly a switch of orientation from the direction of the electric field to the direction of flow is possible by a mere change of frequency when the outer conductivity is higher. Interestingly, in some cases, a coupling between electric field-induced deformation and shear can result in the system admitting an intermediate TU regime while attaining the TT regime at high Mn. The results could enable designing better dielectrophoretic devices wherein the residence time as well as the dynamical states of the vesicular suspension can be controlled as per the application.

Planning working futures: precarious work through carceral space

Geographies of precarious work are advanced through an eight month qualitative study of prisoners nearing release from HMP Brixton in London, providing a spatial rendering of working uncertainty. This builds on geographical scholarship highlighting the porosity of prison walls such that carceral space is understood as non-totalising yet extensive. Release on Temporary License (ROTL) is examined as a mechanism of such porosity, allowing offenders to undertake work outside prison. Within the context of the rehabilitation agenda in England and Wales that emphasises the generative function of prison time, we frame the ROTL as a flow mechanism that anticipates both the end of the custodial sentence and precarious work. Experiences of such precariousness emerge through prisoners’ processes of planning for future work through states of suspension, compulsion and experimentation. The focus on planning work contributes to understandings firstly of the porosity of carceral space and secondly of labour precarity. Firstly, it highlights the frictions in the flow mechanism of the ROTL, such that the porosity of carceral space cannot be understood as seamless mobility. Secondly, these frictions indicate how the structural condition of labour precarity can be lived through forms of mundane stability that might be generative as well as exhausting.

Influence of laser surface texturing on a low‐adhesion and superhydrophobic aluminium alloy surface

An aluminium alloy surface with a microgroove array was fabricated via laser processing, and exhibited superhydrophobicity. The as-prepared surface showed excellent anti-adhesion properties and potential self-cleaning behaviour. The wettability of the fabricated surface was investigated by measurement of the water contact angle. The surface morphology and chemical composition were characterised by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. The wettability of the surface was successfully modified from hydrophilicity to superhydrophobicity by the laser processing. The water contact angle was increased to 155°, and the sliding angle reduced to <;5°, without any chemical modification. Water droplets on the surface existed in an almost perfectly suspended state, resembling a model Cassie state. The superhydrophobic surface showed excellent stability under conditions of external extrusion. This easy and inexpensive modification method is expected to play an important role in extending the applications of aluminium alloys.

Air–Liquid Segmented Continuous Crystallization Process Optimization of the Flow Field, Growth Rate, and Size Distribution of Crystals

The continuous crystallization behavior of an air–liquid segmented tubular crystallization process was investigated using glycine as a model compound. Process parameters such as aspect ratio of the liquid slug, Reynolds number, seed loading, tubing material, slug shape, and tube crystallizer arrangement were optimized experimentally for their effect on the growth rate, size distribution, and morphology of the produced crystals. An Eulerian liquid–solid two-phase model coupled with a realizable k−e model in a computational fluid dynamics platform was also used to simulate the suspension state and the flow trajectory of crystals in a liquid slug. The results of our study indicated that a uniform crystal size benefiting from a heightened flow dynamics of crystals can be achieved under the following conditions: a slug aspect ratio of 1:1, 2 wt % seed loading, a Reynolds number higher than 22.87, a tubing material with highly hydrophobic properties and a resulted highly spherical slug shape. The growth rate of...

Biocompatible Au@Carbynoid/Pluronic-F127 nanocomposites synthesized by pulsed laser ablation assisted CO2 recycling

Ligand-free carbynoid-encapsulated gold nanocomposites (Au@Carbynoid NCs) with blue-shifted localized surface plasmon resonance (LSPR) have been synthesized by CO2 recycling induced by pulsed laser ablation (PLA) of a solid gold target in aqueous solution with NaOH at pH 7.0. High Resolution Transmission Electron Microscopy (HRTEM) images at not destructive acceleration voltage of 80 kV revealed carbynoid nanocrystals around the gold core, associated to the intense bond length alternation (BLA) Raman mode of the carbon atomic wires (CAWs), centered at 2124 cm−1, observed in the Surface Enhanced Raman Scattering (SERS) spectra. It was verified that interlinking process with sp to sp2 conversion of the CAWs is induced both by high acceleration voltage in HRTEM and high irradiance of the excitation beam used in SERS measurements. Post synthesis mixing of Pluronic-F127 copolymer with pre-synthesized Au@Carbynoid NCs allows the formation of a fully biocompatible colloidal solution of Au@Carbynoid/Copolymer NCs. SERS investigation highlights that the Raman band of the BLA mode can be used as efficient Raman tag to monitor the functionalization of the NCs with the copolymer. The biocompatibility of the NCs was demonstrated performing a study of cytotoxicity using human skin fibroblasts. As proof of principle, it was demonstrated that the photodynamic activity of the bifunctional Au@Carbynoid/PF127 NCs in the presence of chlorin e6 (Ce6) drug can be enhanced inducing the aggregation state of the colloidal suspension. The stability of the colloidal dispersions of Au@Carbynoid NCs functionalized with Pluronic-F127 is verified after centrifugation in PBS (0.15 mol L−1 NaCl) solutions, confirming the possibility to use the green carbynoid based NCs as drug-carrier in biological applications.

FEATURES OF SHELL STRUCTURE OF OIL GLOBULE IN WATER-OIL EMULSION

Background The development of oil fields exploited for a long time is characterized by high water cut of oil, which causes a number of serious complications, such as the formation of inorganic salts on the inner surface of oil pipelines, high corrosion activity of the extracted products, and intensive emulsion formation. These complications increase the accident rate, accompanied by environmental and material damage. Attempts to reduce the corrosion rate of pipelines by applying inhibitor protection lead to surfactants concentration increase in the aqueous phase. Removal of salt deposits from tubing and oil pipelines leads to an increase in the mass of mechanical impurities present in the suspended state in the water-oil stream. As a result, electrostatic stabilization of the oil globules in water of the surfactant and the mechanical stabilization of individual oil globules in water by suspended particles occur. Aims and Objectives To examine features of shell structure of oil globule in water-oil emulsion. Results The results of the analysis of literature sources showed that the stability of the emulsions is ensured by the formation of energetically stable globules, the shell of which consists of surfactants, resins and solids, made by hydrogen bonds and van der Waals forces. In the shell of globules, layer of resins and surfactants made by hydrogen bonds and oriented by mutual polarization is formed. In case of emulsion type «oil in water» formation hydrophilic ligand mole-molecules emerge on the shell surface. As the surfaces of globules have like charges, globules are repelling from each other, and electrostatic stabilization of emulsions occurs. Emulsions stability increases in course of time due to globules crushing and aging. For this emulsions stabilization mechanism there is a need of development of new methods of breaking based on the induced in the flow of emulsion directed electric field that can change the orientation of the surfactant molecules and resins in the outer shell of the globules, reduce the surface tension, the magnitude of the charge on the surface and, thus, ensure the fusion of globules colliding in a turbulent flow.

Bail Again: Reforming Appellate Review of Bail Determinations in State Court

On any given day, local jails detain nearly half-a-million people who cannot afford bail. Opposition to this status quo, and to monetary conditions of pretrial release more broadly, has reached a fever pitch in recent years. Critics from across the political spectrum decry bail as a wellspring of mass incarceration and acknowledge its profoundly discriminatory effects, particularly within low-income communities of color. Academic studies link bail to poorer case outcomes and a myriad of destabilizing collateral consequences for pretrial detainees. And local justice systems have begun to grapple with the high human and economic costs of incarcerating large numbers of people still presumed innocent under the law. Amid widespread agreement that bail is broken, it is easy to forget that the system has been in a suspended state of crisis for decades and proved resistant to change before. In the face of this critical and persistent problem, this Note offers appellate review of bail determinations as a viable avenue for reform. By revamping the “bail appeal”—a procedure that has received little attention from reformers and academics alike—states have an opportunity to reduce the scourge of pretrial detention, conserve the time and resources of local justice systems, and provide a durable promise of pretrial justice.

Solid-liquid suspension of microcarriers in stirred tank bioreactor – Experimental and numerical analysis

Solid-liquid suspensions in stirred tank reactors are common operations in many processes, including bioprocesses such as animal or stem cell cultures. These cells are often anchorage-dependent, i.e. they need to adhere to a surface to grow. Typically, they are cultivated on the surface of small spherical microbeads, the so-called microcarriers, suspended in stirred-tank bioreactors.As far as we know, no extensive experimental characterization, and thus no validated simulation approach, of microcarrier suspensions in stirred-tank reactor exists in the literature. Therefore, the first aim of this work is to develop an experimental technique based on light attenuation to characterize the spatial distribution of particle concentration for various particle suspension states. The second aim is to determine the validity of Euler-Euler CFD simulations to predict the spatial distribution of low density particles, such as microcarriers, in a stirred tank bioreactor.Experiments and simulations were performed in a small hemispherical bottom bioreactor stirred with a down-pumping axial impeller. The particles used were Cytodex-1 microcarriers (dP=162μm and ρS=1020 kg m−3) at a solid concentration of 10% in volume.The light attenuation technique enabled the characterization of the spatial distribution of the solid phase in the whole bioreactor, even for very dense suspensions by advantageously using the optical properties of the Cytodex-1 microcarriers. The analysis of the solid spatial distribution shows that the bioreactor volume can be divided in three distinct zones: a clear layer below the free surface where αS,layer tends to 0, a bulk zone where the solid phase is homogeneously distributed (αS,bulk⩽αS) and a packed bed of motionless particles at the bottom (αS,bed=αS,max). One very interesting finding is that the evolution of the bulk solid concentration is directly proportional to the agitation rate and its value equals the averaged volume fraction αS,bulk=αS at N=Njs.Concerning the simulation results, the modeling approach presented in this work enables a reasonable estimation of the just-suspended agitation rate Njs. Nevertheless, the solid spatial distributions are not well predicted for agitation rates below or above Njs. The solid concentration at the vessel bottom is underestimated for N<Njs but overestimated for N⩾Njs.

Suspension state promotes metastasis of breast cancer cells by up-regulating cyclooxygenase-2.

Hematogenous metastasis requires tumor cells to detach from primary tumor into blood/lymphatic circulation and extravasate. Tumor cells in the blood circulation system, named circulating tumor cells (CTCs), are in a suspension state, with unique cytoskeletal structure and molecular phenotype different from primary tumor cells. The aim of this study is to assess the impact of suspension state on the metastatic potential of breast cancer cells (BCCs) and study its underlying mechanism.Methods: BCCs were cultured on low-adhesion plates to mimic the suspension state. Conventional adherent culture BCCs were used as the control. This study examined the metastatic potential of adherent and suspension BCCs in vitro and in vivo. RNA sequencing analysis, siRNA, and inhibitors were used to determine the underlying molecular mechanism.Results: The suspension state significantly increased the metastatic potential of BCCs, but slightly suppressed their tumor growth. RNA sequencing analysis revealed that the suspension state resulted in an acquisition of unique molecular signature enriched in pro-metastatic and tumor-suppressive genes. Specifically, prostaglandin-endoperoxide synthase 2 (PTGS2), which encodes protein cyclooxygenase-2 (COX-2), was identified as a highly up-regulated gene in suspension state compared with adherent cultured BCCs. Inhibition of the catalytic activity of COX-2 by celecoxib markedly suppressed suspension-increased migration and invasion of BCCs. In addition, knock-down of COX-2 by siRNA reduced the experimental lung metastasis formation of suspension cultured BCCs, which was associated with a remarkable decrease in retention and survival of BCCs in lungs of mice in the early stage of metastasis. Activation of Ca2+/calcineurin (CaN)/nuclear factor of activated T cells (NFAT) pathway and disruption of cytoskeleton contributed to the COX-2 up-expression by suspension state.Conclusions: Our results demonstrate that suspension state plays an important role in the metastatic potential of CTCs, and suggest a potential application of COX-2 inhibitor for anti-metastasis.

Suspension state promotes extravasation of breast tumor cells by increasing integrin β1 expression

Mechanical microenvironment can strongly affect the metastatic efficiency of circulating tumor cells. However, the effect of suspension state on their extravasation and the mechanisms involved are still unclear. To explore the influence of suspension state on extravasation (including adhesion, spreading and transendothelial migration) of breast tumor cells and its relevant molecular mechanism, MDA-MB-231 cells were cultured on poly (2-hydroxyethyl methacrylate) coated 6-well plates to minic the suspension state. Suspension state promoted adhesion, spreading and transendothelial migration of MDA-MB-231 cells to EAhy926 endothelial cells (ECs) monolayer under both the static condition and 0.5 dyne/cm2 flow shear stress (FSS). The number of cells adhered to ECs monolayer reached 2.15 (static condition, 3 d) and 1.67 (FSS, 3 d) times, and the number of migration reached 10.60 times, respectively, as compared to that in adhesion state. Moreover, MDA-MB-231 cells knockdown of integrin β1 provoked poor adhesion and transendothelial migration, as compared with MDA-MB-231 cells. But it made no difference in cell spreading. Our results implied the increasing expression of integrin β1 induced by suspension culture promoted the adhesion and transendothelial migration of MDA-MB-231 cells, but had no significant influence on their spreading.

The Mystery of Aviation

Suddenly the Mazowian landscape reared, it swerved askew from its logical angle and absolutely refused to straighten out no matter how much mental effort put into it doing so. The gray curtain of clouds was perforated. Blue sky, always present here at these altitudes, brushed against the pupils of my eyes. By now a cozy calm smoothness reigned beneath the wing. Cotton candy spread out over the spacious sky. I am free from rain, torrential storms, inundation and all sorts of excesses of nature, I am getting a rest from myself. In a state of suspension I belong nowhere. At the controls is an important surrogate for God. During the last seven years I obstinately stuck to the earth. This dearth of take offs would have lasted longer were it not for Jozef Wittlin...

Oh Paris! The Journeys of Lasse Braun’s 8mm Pornography

Oh Paris! The Journeys of Lasse Braun’s 8mm Pornography Mariah Larsson (bio) An easy way to challenge the concept of national cinema is by drawing on examples: if a Danish film director makes a film, set in the United States, funded by various European institutions and production companies, in Trollhättan, Sweden, bringing in an Icelandic singer as the star of the film as well as a French cinematic icon and American actors—how do we describe that film? Film journalists and critics have used the disparaging term “Euro-pudding” to mark such ventures, but as various recognized auteurs have come to exploit the possibilities of European funding, this type of transnational film production has become much more common and is not routinely disregarded anymore. The same kind of transnationality can be found in a 1970s porn context: if an Italian pornographer, with a production company at the time based in Copenhagen, makes a film in France with French and Vietnamese performers—how do we describe that film, in particular if the film surfaces in an American archive with an Italian title? Such is the case for the film Hotel Amour (Lasse Braun), of the Oh Paris! series from 1971 that also includes Petite fleur and Magnifique! Comparing Dancer in the Dark (Lars von Trier, 2000), described in the first instance, with Hotel Amour may seem far-fetched, but I would say that in terms of maverick transnationalism the two directors are not so different. The opportunistic transnationalism—that is, “responding to available economic opportunities at a given moment in time and in no wise about the creation of lasting networks or about the fostering of social bonds”—is evident in both cases, and in their respective contexts both are recognized as auteurs with distinct personal visions.1 The purpose of this article is not to compare Lars von Trier and Lasse Braun. Rather, I wish to point to and discuss some aspects of late 1960s to early 1970s pornography, using Lasse Braun and Hotel Amour to argue that adult film history provides a perspective on transnational film studies that contests received notions about how transnational films are produced and circulate. In fact, adult film and pornography in general challenge three traditionally strong conceptualizations of film history. First, because many such films were made in some [End Page 158] sort of transnational collaboration but were also often excluded from national film histories, they make evident the concept of national cinema as a clearly demarcated canon of films. Second, the history of adult film and pornography contests the notion of a world-dominant American (Hollywood) cinema, as the international diversity of productions on the internet and in the former “adult” sections of video stores demonstrate. Third, adult film and pornography defy the notion that popular European genre cinema and stars have difficulty traveling—that is, that European film stars often have to make a mark in a Hollywood film to be recognized in other European countries than their own. Transnationality has become something of a buzzword within film studies—and, as Mette Hjort astutely observes, it seems to carry with it an intrinsic value in and of itself. Nevertheless, as Hjort goes on to point out, there are many different types of transnational cinema, and by distinguishing them, their ostensible value can be defined and measured.2 In addition, one could argue that “transnationality” per se is a neutral term, simply referring to cross-border interactions. Outside of film studies, it is used in conjunction with both positive and negative issues, like transnational cooperation or transnational crime. However, what is quite often disregarded in discussions of transnational cinema is the importance of nationality to making someone or something itinerant. Without any kind of acknowledged nationality, travel becomes difficult and may leave the traveler in a state of suspension, an eternal limbo, much like the stranded Viktor Navorski (Tom Hanks) in Steven Spielberg’s The Terminal (2004), whose passport became invalid when his home country ceased to exist. Nationality, or at least an assumed nationality, is in fact a prerequisite for transnational interactions to take place. Perhaps the most apparent example of the transnationality of pornography in the predigital era, and...

Перенос примеси наночастиц в сосуде с наклонными боковыми границами

Mixtures of components with different densities are stratified in the gravitational field. Colloidal particles with sizes about 10-100 nanometers can be supported by thermal motion in a suspended state, which distinguishes them from roughly dispersed mixtures. In the case of inclined lateral boundaries longitudinal inhomogeneity of the nanoparticles concentration is occurring. In this case, the mechanical equilibrium of the mixture is impossible, and a macroscopic fluid flow occurs. The paper studies the influence of flow on the sedimentation of nanoparticles in colloidal mixtures.

Interface adhesion property between graphene film and surface of nanometric microstructure

The performance of graphene can be influenced by its surface mophology, while the surface morphology of graphene is closely related to the substrate. The adsorption and peeling process of graphene on a corrugated surface can provide a theoretical basis for the functional preparation and transfer of graphene. In this work, the adhesion properties and peeling process of graphene on nanostructured substrate are investigated by using molecular dynamics (MD) simulation. As an effective tool of atomic collision theory, MD simulation can provide detailed information about the adsorption configuration and peeling properties of graphene on the nanostructure surface, making up for the deficiency of experiment. The results indicate that graphene can conformably coat on the surface, partially adhere to or remain flat on the top of the stepped substrate. We find that the continuous transition occurs in the adsorption configuration of graphene on the stepped substrate, but the repeated process appears in the transition from partial adherence to conformable coating. When graphene coats on the nanostructured substrate conformably, the adsorption energy can reach its peak value. The adsorption configuration of graphene can change from suspension to partial adhesion after the adsorption energy has exceeded 360 eV -2. It is also shown that the average peeling force fluctuates periodically when the absorption configuration of graphene is conformably coated or suspended on the stepped substrate. Two kinds of behaviors can be noticed in the peeling process. The graphene can directly slide over the bottom while it is fully coated on the surface. The graphene is separated directly from the corrugated surface while it suspends or partially adheres to the surface. If the absorption configuration of graphene is in the suspension state, the average peeling force appears to change drastically within a section of peeling distance and then decreases immediately below zero. Although the flexural stiffness of graphene can be overcome, the interfacial friction between graphene and the substrate is also an essential factor affecting the final adsorption configuration. In this paper, we propose a theoretical formula for the average peeling force according to the changes of size parameters on the nanostructured substrate. The theoretical formula is validated by the simulation results. In addition, with the increase of peeling angle, the average peeling force first increases and then becomes smaller. As a result, a larger average peeling force can be found when the graphene with Stone-Wales defect structure is peeled from the flat substrate. With the increase of double vacancy defect, the maximum peeling force decreases in a certain range, whereas it increases beyond this range. This work can provide a theoretical reference for exploring the peeling property and the adhesion mechanism of graphene on nanostructure surface.

"Liquid, gel and soft glass" phase transitions and rheology of nanocrystalline cellulose suspensions as a function of concentration and salinity.

The colloidal size and rod morphology of nanocrystalline cellulose (NCC) lead to suspensions with useful phase and gelation behaviours as well as complex rheologies. However, these have not been comprehensively evaluated previously. Here we report the detailed phase behaviour of sulphonated NCC aqueous suspensions as a function of concentration and salinity. Four phases - liquid, viscoelastic, repulsive glass and attractive glass/gel - are identified in terms of their distinct rheological behaviours. The liquid-solid transitions (LSTs) are determined rheologically, and these are supported by a simplified model based on the DLVO theory that indicates the importance of charge in determining the phase behaviour. Rheology is also used to investigate the solid-solid transition from a repulsive glass to an attractive gel with increasing salt at high NCC concentrations. A time-dependent aging phenomenon is observed in suspensions with a composition just below the LSTs, and the implications of this on the dynamics occurring during gelation processes are discussed. This work can be directly applied to the development of structure-function relationships and the expanding utilisation of NCC suspensions, whilst also providing a basis for the study of charged colloidal rods more generally and evaluation of theoretical models.

Fiber Orientation State of Cellulose Nanofiber Suspension in Simple Shear Flow : Effect of Polymer

Fiber Orientation State of Cellulose Nanofiber Suspension in Simple Shear Flow : Effect of Polymer