Bumpy Surface Research Articles

Implicit Frictional Boundary Handling for SPH.

In this article, we present a novel method for the robust handling of static and dynamic rigid boundaries in Smoothed Particle Hydrodynamics (SPH) simulations. We build upon the ideas of the density maps approach which has been introduced recently by Koschier and Bender. They precompute the density contributions of solid boundaries and store them on a spatial grid which can be efficiently queried during runtime. This alleviates the problems of commonly used boundary particles, like bumpy surfaces and inaccurate pressure forces near boundaries. Our method is based on a similar concept but we precompute the volume contribution of the boundary geometry. This maintains all benefits of density maps but offers a variety of advantages which are demonstrated in several experiments. First, in contrast to the density maps method we can compute derivatives in the standard SPH manner by differentiating the kernel function. This results in smooth pressure forces, even for lower map resolutions, such that precomputation times and memory requirements are reduced by more than two orders of magnitude compared to density maps. Furthermore, this directly fits into the SPH concept so that volume maps can be seamlessly combined with existing SPH methods. Finally, the kernel function is not baked into the map such that the same volume map can be used with different kernels. This is especially useful when we want to incorporate common surface tension or viscosity methods that use different kernels than the fluid simulation.

High flavivirus structural plasticity demonstrated by a non-spherical morphological variant

Previous flavivirus (dengue and Zika viruses) studies showed largely spherical particles either with smooth or bumpy surfaces. Here, we demonstrate flavivirus particles have high structural plasticity by the induction of a non-spherical morphology at elevated temperatures: the club-shaped particle (clubSP), which contains a cylindrical tail and a disc-like head. Complex formation of DENV and ZIKV with Fab C10 stabilize the viruses allowing cryoEM structural determination to ~10 Å resolution. The caterpillar-shaped (catSP) Fab C10:ZIKV complex shows Fabs locking the E protein raft structure containing three E dimers. However, compared to the original spherical structure, the rafts have rotated relative to each other. The helical tail structure of Fab C10:DENV3 clubSP showed although the Fab locked an E protein dimer, the dimers have shifted laterally. Morphological diversity, including clubSP and the previously identified bumpy and smooth-surfaced spherical particles, may help flavivirus survival and immune evasion.

Clinical case of breast tumor relapse in domestic cat

Domestic shorthair 10-year-old cat, not sterilized, not vaccinated, feeding from the table. We went to the clinic with breast cancer. General and special research methods were performed: blood analysis, x-ray examination of the lungs and abdominal ultrasound. Based on anamnesis and clinical examination, the diagnosis was made: a malignant breast tumor. The operation was performed. The operating material is sent for histological examination. Chemotherapy was prescribed. After the fi rst chemotherapy and monitoring of the animal's condition, it was necessary to perform a second unilateral mastoectomy of the remaining mammary glands, but the animal's owners refused to perform the operation. Chemotherapy was performed twice. Re-applied, after a year and a half with a sharp deterioration in the General condition and the appearance of a new tumor on the non-removed mammary glands. The owners refused the necessary treatment and decided to euthanize the cat. At the autopsy, breast neoplasms are presented as tubercles of various sizes. There are pronounced signs of inflammation, ulceration and necrosis foci. In the chest cavity, the lungs are enlarged, there were single and multiple formations of white and brown color, round shape of different diameters, dense consistency. There is a large number of metastases in the liver parenchyma. The organ is enlarged in size, dark brown in color, irregularly colored, with an uneven (bumpy) surface. In General, there are many dense nodes of a round-oval shape of white color, of various diameters. Histological examination of the tumor revealed foci of necrosis, atypical glandular complexes with frequently occurring mitosis figures. This structure indicates a low-grade breast adenocarcinoma. In the lungs, there is an expansion of the alveoli and bronchioles, thinning and rupture of the interalveolar partitions. There is a complex of tumor cells. In the liver, there is a lack of structural units of the liver, hepatocytes disperse chaotically, liver triads do not have a clear localization, atrophy and necrosis are expressed. Metastases in the liver, various forms. In a cat, a breast tumor interpreted as an adenocarcinoma had different biological behavior. At the initial diagnosis-adenocarcinoma of medium differentiation, and a year and a half later-low-grade adenocarcinoma.

Optimized state feedback control of quarter car active suspension system based on LMI algorithm

Suspension systems are applied in vehicles so as to improve the passengers ride comfort, vehicle stability and better road handling when the vehicle moves on roads with bumps and terrains. In this paper, Linear Matrix Inequality (LMI) and linear quadratic regulator (LQR) controllers were proposed and this was also compared with passive suspension system. Using nonlinear quarter car active suspension system model with hydraulic actuator to reduce the effect of bumpy road surfaces on vehicle and hence improve passenger ride comfort. Vehicle body suspension travel and wheel deflection were measured to determine the performance of the active suspension system. Mean absolute error (MAE) and integral square error (ISE) were used as the performance indexes, thus a MAE and ISE of passive 75.01%, LQR 82.65% and LMI 89.11% and passive 4.11x10−6, LQR 3.24x10−6 and LMI 2.19x10−6 respectively were recorded. Based on the simulation results and analysis, the LMI based control performs better in minimizing vibration effects and also guarantee better ride quality and vehicle stability when compared to the conventional LQR and the passive suspension system.

Atmospheric-pressure plasma jet deposition of bumpy coating improves polypropylene surface flashover performance in vacuum

Polypropylene (PP) with low leakage current and high mechanical strength is a promising candidate for recyclable vacuum insulation applications, but its surface flashover voltage is low. Advantageously to widely used technologies such as fluorination and sanding, here it is shown that plasma polymerization can provide a new way to achieve higher flashover strength by depositing a bumpy coating in a two-step process using atmospheric-pressure plasma jet. The experimental results show that the suitable volume content of methyl methacrylate monomer in argon to obtain plasma polymerized coating is about 5%, and the corresponding vacuum flashover voltage is improved by 35.5%. Moreover, the morphology analysis of surface appearance shows that the PP has a bumpy surface after plasma jet deposition. The surface charge dissipation of the PP treated for 5 min is about 26% higher than that of the untreated sample, and the secondary electron emission yield decreases from 2.35 to 1.64, which can result in the surface flashover performance enhancement. This plasma-based method for depositing bumpy micropatterns is simple and may be applicable in other areas.

Influence of submarine topography and associated sedimentary processes on the distribution of live and dead rhodoliths near Udo Island, Korea

The distribution of rhodoliths growing near the Udo islands in the Republic of Korea was identified and the controlling factors influencing their growth and distribution were investigated. Their mineralogical and textural features of growth patterns and the physical oceanographic properties that influence the rhodolith distribution were also examined. The study area is relatively shallow with a water depth of less than 20 m and thus is influenced by seasonal typhoons and winter storms as well as wind-driven waves and strong tidal currents. The study site was divided into four areas based on the distribution of the rhodoliths and the associated physical and biological factors. The bedrock-exposed area partially covered with live rhodoliths (area I) at depths of up to 10 m provides an environment characterized by high wave energy and irregular seabed topography, which precludes continuous rhodolith growth and accumulation. Living rhodoliths were rarely observed and the sediments continuously migrate to adjacent beaches and shallow waters. The depth range of 10–15 m can be divided into the northern (the active growth area of live rhodoliths, area II) and southern (the sand dune area with dead rhodoliths, area III) areas. The southern part, where underwater sand dunes appear, is predominantly distributed with sandy sediments and ripple marks, which makes it an adverse environment for continuous growth of rhodoliths. In contrast, the northern part has a bowl-shaped seabed with gentle slopes, providing a stable condition for the constant and active growth of rhodoliths. In areas deeper than 15 m (the seagrass-covered area with live rhodoliths, area IV), an irregular seabed topography is present and the wave energy is reduced. Consequently, various sizes of rhodoliths with bumpy surfaces are distributed throughout this area. Therefore, it is suggested that the distribution of the rhodoliths is affected by the bottom topography and the associated physical energy, in conjunction with different types of surface sediments. The results of this study will increase the understanding of rhodoliths elsewhere in the world.

Synergistic role of graphene oxide-magnetite nanofillers contribution on ionic conductivity and permeability for polybenzimidazole membrane electrolytes

Efficient nanofillers within polymeric electrolytes are an interesting design for constructing high-performance membranes for direct methanol alkaline fuel cells. In this work magnetite (Fe3O4) particles are synthesized onto graphene oxide (GO) nanofillers and incorporating into a polybenzimidazole (PBI) matrix for membrane formation. The Fe3O4 nanoparticles are simultaneously anchored onto GO carbon basal planes to form GO-Fe3O4 via the solvothermal process. The pristine PBI, PBI/GO, PBI/Fe3O4, and PBI/GO-Fe3O4 composites are formulated and doped with potassium hydroxide solution to form ionic conductors. GO nanofillers suppress the methanol permeation rate in PBI/GO-Fe3O4 composite membranes while the anchored Fe3O4 nanoparticles result in a bumpy surface, reducing chain packing and promoting anionic conductivity via the loose polymeric free volume. Therefore, the conductivity-to-permeability selectivity of PBI/GO-Fe3O4 composite membrane is improved three times than other samples. The maximum peak power density (Pmax) of a fuel cell employing the PBI/GO-Fe3O4 composite membrane achieves 233 mW cm−2 at 80 °C. The superior power output is attributed to the combined effect of the enhanced anionic conduction resulting from anchored GO-Fe3O4 particles' steric hindrance on polymer chains to enlarged ion diffusion pathways, and the reduced methanol cross-over from the GO's high aspect ratio to retard molecular permeation in the composite membrane.

Molecular basis of dengue virus serotype 2 morphological switch from 29°C to 37°C.

The ability of DENV2 to display different morphologies (hence different antigenic properties) complicates vaccine and therapeutics development. Previous studies showed most strains of laboratory adapted DENV2 particles changed from smooth to “bumpy” surfaced morphology when the temperature is switched from 29°C at 37°C. Here we identified five envelope (E) protein residues different between two alternative passage history DENV2 NGC strains exhibiting smooth or bumpy surface morphologies. Several mutations performed on the smooth DENV2 infectious clone destabilized the surface, as observed by cryoEM. Molecular dynamics simulations demonstrated how chemically subtle substitution at various positions destabilized dimeric interactions between E proteins. In contrast, three out of four DENV2 clinical isolates showed a smooth surface morphology at 37°C, and only at high fever temperature (40°C) did they become “bumpy”. These results imply vaccines should contain particles representing both morphologies. For prophylactic and therapeutic treatments, this study also informs on which types of antibodies should be used at different stages of an infection, i.e., those that bind to monomeric E proteins on the bumpy surface or across multiple E proteins on the smooth surfaced virus.

Fabrication of anodic porous alumina via galvanostatic anodizing in alkaline sodium tetraborate solution and their morphology

The anodizing of aluminum in an alkaline sodium tetraborate (Na2B4O7) solution was investigated with respect to the nanostructural characterization of anodic porous alumina. Electropolished aluminum specimens were galvanostatically anodized under various conditions in 0.1–0.5M sodium tetraborate solutions at 293–353K and a current density of 2.5–400Am−2. Anodic oxide with numerous flower-like defects was formed by anodizing in a 0.1M Na2B4O7 solution due to the film breakdown with continuous visible sparking. On the other hand, a uniform porous alumina film without any breakdown was successfully obtained by anodizing a more concentrated solution than 0.3M at 333K. The anodic oxide was almost pure alumina and consisted of a thin outer layer with numerous small pits and a thick inner layer with typical porous alumina cells. The pore walls possessed continuous bumpy surfaces measuring 10–20nm in roughness. As the temperature further increased to 353K, the regularity of the porous alumina improved due to the high current density of more than 150Am−2 during anodizing. Slippery superhydrophobic and sticky superoleophobic aluminum surfaces could be easily fabricated via high temperature anodizing and subsequent self-assembled monolayer modification.

Selaginella ayitiensis and S. brigitteana (Selaginellaceae): two new species from Hispaniola Island

Two new species of Selaginella (i.e. S. ayitiensis and S. brigitteana) from Hispaniola Island are described. Illustrations are provided for both new species and their affinities are discussed. Selaginella ayitiensis was collected in the Massif de la Hotte, Haiti, and is characterized by its long-creeping stems, corrugate to bumpy leaf upper surfaces, broadly acute to obtuse or apiculate median leaf apices, and white megaspores. It is morphologically related to the “Selaginella flexuosa group”. Selaginella ayitiensis differs chiefly from S. denudata and S. krugii (the only two other members of the “Selaginella flexuosa group” in the Greater and Lesser Antilles) by the shape of the median and lateral leaves apices. Selaginella brigitteana is known from different localities in the Dominican Republic and Haiti; it can be distinguished by its long-creeping, 2–4-branched stems, coriaceous leaves with the upper surfaces glossy, the median leaves with broadly hyaline, long-ciliate margins, and short-acuminate apices tipped by 2 or 3 cilia, and light yellow to cream megaspores. Selaginella brigitteana differs from S. leonardii, with which it has been confused in the past, by its broadly ovate median leaves with rounded, non-auriculate, and glabrous outer bases, submarginal and marginal stomata along proximal ½ of outer halves of the laminae, and with the upper surfaces glossy, comprising rounded and rectangular to elongate cells, many of which are papillate.

Three-Dimensionally Structured Flexible Fog Harvesting Surfaces Inspired by Namib Desert Beetles.

Fog harvesting of the Namib desert beetles has inspired many researchers to design artificial fog harvesting hybrid surfaces, which commonly involve flat hydrophilic patterns on hydrophobic surfaces. However, relatively less interest has been shown in the bumpy topography of the Namib desert beetle’s dorsal surface as well as its curved body shape when designing artificial hybrid surfaces. In this work, we explore a fog harvesting flexible hybrid surface that has a superhydrophilic 3D copper oxide pattern on a hydrophobic rough elastomer background surface enabled by transferring a copper layer from a prepared donor substrate to a receiving elastomer substrate. The water collection rates of the hybrid surface and control samples are measured, and the results reveal the advantages of 3D bumpy structures on a curved shape surface to facilitate fog harvesting, particularly in more unfavorable fog stream conditions. The curved 3D bumpy hybrid surface exhibits an over 16 times higher water collection rate than the flat 2D hybrid surface in the fog stream in parallel to the hybrid surface. This work provides an improved understanding of the role of the Namib desert beetle’s bumpy dorsal surface and curved body shape, and offers an insight into the design of novel surfaces with enhanced fog harvesting performance.

Near-atomically flat, chemically homogeneous, electrically conductive optical metasurface.

Metasurfaces, or two-dimensional arrays of subwavelength-scale structures, can exhibit extraordinary optical properties. However, typical metasurfaces have a bumpy surface morphology that may restrict their practical applications. Here, we propose and demonstrate an optical metasurface that is composed of a thin metallic film, with hidden dielectric structures underneath, and a metal back mirror layer. Exploiting the large difference between the Thomas-Fermi screening length for longitudinal electric fields and the skin depth for transverse electromagnetic fields, the near-atomically flat top surface of the proposed structure can appear homogeneous chemically and electrically but highly inhomogenous optically. The size and shape of the hidden dielectric structures as well as the thickness of the top metallic layer can be tailored to acquire desired optical properties. We performed both theoretical and experimental studies of the proposed metasurface, finding a good agreement between them. This work provides a new platform for ultra-flat optical devices, such as a wavelength selective electrode, diffusive back reflector, meta-lens, and plasmonically enhanced optical biosensors.

Size-controllable and uniform gold bumpy nanocubes for single-particle-level surface-enhanced Raman scattering sensitivity.

Gold nanocubes modified to form roughened structures, namely, gold bumpy nanocubes (Au BNCs), with very strong and uniform single-particle surface-enhanced Raman scattering (SERS) intensity were developed. The Au BNCs were synthesized by controlled regrowth, competing with 4-aminothiophenol during gold nanocube growth. Under controlled conditions, Au BNCs of various sizes were successfully generated while maintaining a cubic outline. As the bumpy surfaces of the Au BNCs increased the number of hot spots on a single cubic nanoparticle, these nanoparticles exhibited 15-times stronger SERS than normal cubic nanoparticles. We expect that this unique nanostructure will be applicable in versatile fields as an ultrasensitive SERS nanoprobe or nanoantenna owing to its cubic outline and high uniformity, as well as the ease of particle size adjustment.

PH-Responsive Charge-Conversional Poly(ethylene imine)-Poly(l-lysine)-Poly(l-glutamic acid) with Self-Assembly and Endosome Buffering Ability for Gene Delivery Systems.

Poly(ethylene imine)-poly(l-lysine)-poly(l-glutamic acid) (PKE) polymers with various glutamic acid portions were synthesized by ring opening polymerization of l-lysine N-carboxyanhydride (NCA) and l-glutamic acid NCA from poly(ethylene imine) 1.8 kDa (PEI1.8k) as a macroinitiator. It was found that their glutamic acid residues could buffer endosomal pH. PK5E9 polymer could form nanoparticles by self-assembly and nanosized polyplexes, possessing pH-responsive charge-conversion properties. PK5E9 or its polyplex nanoparticles showed polyhedral structures with bumpy surfaces. Its cytotoxicity was marginal at both pH 7.4 and 6.0, and its transfection efficiency was highly increased at pH 6.0. The improved transfection efficiency in acidic conditions was thought to be induced by elevated cellular uptake of the polyplexes via charge-conversion from negative to positive charges. Its transfection was also found to be mediated by endosomal escape through endosome buffering by bafilomycin A1-treated transfection. In conclusion, PK5E9 polymer with self-assembly and endosome buffering ability was found to possess potentials for efficient gene delivery systems in acidic conditions via charge conversion, which may be applied for tumor microenvironment-targeting.

Synthesis, characterization, and pharmacological evaluation of zinc oxide nanoparticles formulation.

Zinc oxide nanoparticles (ZnONPs) are being used extensively in manufacturing skin lotions and food products and in various biological and pharmaceutical industries because of their immunomodulatory and antimicrobial properties. In this study, ZnONPs were synthesized by a precipitation method and characterized by X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM), and ultraviolet-visible spectroscopy to investigate their structural, morphological, and optical properties. For in vivo evaluation, 40 healthy albino mice were randomly allocated to four equal groups among which the first one was the control group, while the second, third, and fourth were treated with carbon tetrachloride (CCl4), a blend of CCl4 and ZnONPs, and ZnONPs alone, respectively, for 21 days. The XRD analysis confirmed hexagonal wurtzite type structures having an average crystallite size of 41.54 nm. The morphology of ZnONPs analyzed through SEM showed uniform distribution of the grains and shape of the synthesized oxide. The energy band gap of the ZnONPs was found to be 3.498 eV. Hepatic and renal damage following CCl4 administration was apparent after 14 days and was increased at the 21st day, showing nodular fibrotic masses in the liver and bumpy surfaces in the kidney as observed by gross and histological examination. Coadministration of ZnONPs (15 mg/kg b.w. intragastrically 5 days a week) significantly prevented the CCl4-dependent increases in alanine transaminase, aspartate transaminase, creatinine, and urea levels, suggesting a protective potential of ZnONPs.

Intracellular calcite and sulfur dynamics of Achromatium cells observed in a lab-based enrichment and aerobic incubation experiment.

We investigated the intracellular dynamics of calcite and sulfur in the large sulfur-oxidizing, calcite-accumulating bacterium Achromatium, with an emphasis on oxygen exposure as a physiological control. For this purpose, morphological changes and possible accretion mechanisms of calcite granules in cells that were freshly collected from natural Achromatium-containing sediment were compared to cells from the same source after prolonged exposure to atmospheric oxygen. Intracellular sulfur is oxidized and removed in response to oxygen exposure. Calcite granules also undergo distinct oxygen-related dynamics; they alternate between tightly packaged, smooth granules with narrow but sharply defined interstitial spaces in atmospheric oxygen-exposed cells, and more loosely packaged granules with irregular, bumpy surface texture and larger interstitial spaces in cells that were not artificially exposed to oxygen. These results suggest that morphological changes of the calcite granules reflect their changing physiological role inside the cell. Sulfur oxidation and calcite dissolution appear to be linked in that proton generation during sulfur oxidation is buffered by gradual calcite erosion, visible in the smooth, rounded surface morphology observed after oxygen exposure. Our results support the hypothesis that calcite dynamics buffer the intracellular pH fluctuations linked to electron acceptor limitation during proton-consuming sulfide oxidation to sulfur, and electron acceptor abundance during proton-generating sulfur oxidation to sulfate.

Synthesis of electrospun polyacrylonitrile- derived carbon fibers and comparison of properties with bulk form.

This study deals with the fabrication of polyacrylonitrile (PAN) nanofibers via an electrospinning process followed by stabilizing and carbonization in order to remove all non-carboneous matter and ensure a pure carboneous material. The as-spun PAN fibers were stabilized in air at 270°C for one hour and then carbonized at 750, 850, and 950°C in an inert atmosphere (argon) for another one hour. Differential scanning calorimetry and Raman spectroscopy were employed to determine the thermal and chemical properties of PAN. Surface features and morphologies of PAN-derived carbon nanofibers were investigated by means of scanning electron microscopy (SEM). SEM micrograms showed that fiber diameters were reduced after carbonization due to evolution of toxic gases and dehydrogenation. The Raman spectra of carbonized fibers manifested D/G peaks. The Raman spectroscopy peaks of 1100 and 500 cm-1 manifested the formation of γ phase and another peak at 900 cm-1 manifested the formation of α-phase. The water contact angle measurement of carbonized PAN fibers indicated that the nanofibers were superhydrophobic (θ > 150o) due to the formation of bumpy and pitted surface after carbonization. In DSC experiment, the stabilized fibers showed a broad exothermic peak at 308°C due to cyclization process. The mechanical andThermal analysis was used to ascertain mechanical properties of carbonized PAN fibers. PAN-derived carbon nanofibers possess excellent physica and mechanical properties and therefore, they may be suitable for many industrial applications such as energy, biomedical, and aerospace.

(Invited) Fabrication of Copper/Carbon Nanotube Composite Films Using Plating Techniques

Carbon nanotubes (CNTs) [1,2] have excellent thermal conductivity [3], extremely high current-carrying capacity (ampacity), i.e., stable electrical resistance in the presence of high currents [4], and superior mechanical properties [5,6]. Metal/CNT composites are therefore expected to be potential functional materials, and there have been many investigations concerning the fabrication of metal/CNT composites [7,8]. Composite plating is one promising process for the fabrication of metal/CNT composite films, and its application to such has been investigated [9]. In particular, Cu/CNT composite films are expected to be used for electronics applications. CNTs are generally categorized into single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs). CNTs have anisotropic electrical and thermal conductivity, i.e., they have higher electrical and thermal conductivity in the axis direction than in the direction perpendicular to the axis direction. In this study, Cu/MWCNT and Cu/SWCNT composite films were fabricated using composite plating techniques, including electroplating and electroless plating. The dispersibility of CNTs in the plating baths is extremely important for composite plating with CNTs that are hydrophobic. Polyacrylic acid (mean molecular weight 5000) is an effective dispersant for MWCNTs in an acidic copper sulfuric bath [10], and Cu/MWCNT composite films with a homogeneous MWCNT distribution have been formed by electroplating using such a Cu/MWCNT composite bath [11,12]. Metal/MWCNT composite films, including the Cu/MWCNT composite film, intrinsically have a tendency toward a bumpy surface morphology due to the (anisotropic) electrical conductivity of MWCNTs [13]. However, a relatively flat surface morphology could be obtained using appropriate current densities (cathode overpotentials) [14] or surfactants [15]. In addition, reverse current electrodeposition could be used to increase the MWCNT content in Cu/MWCNT composite films [16]. Cu/MWCNT composite films have also been obtained by electroless plating using an alkaline bath. Ethylenediaminetetraacetic acid (EDTA), glyoxylic acid and sodium dodecyl sulfate (SDS) + hydroxypropyl cellulose (HPC) were used as a complexing agent, a reducing agent and surfactants for MWCNTs, respectively [17]. The Cu/MWCNT composite films were also successfully fabricated on an acrylonitrile butadiene styrene resin substrate [18]. SWCNTs have the smallest diameter among CNTs and have a tendency to form a characteristic aggregate known as a bundle. This bundle cannot be disintegrated to a primary particle, i.e., single SWCNTs, with the addition of dispersants alone. The use of both a powerful mechanical disintegration method and a dispersant is effective for the disintegration of SWCNT bundles. The selection of dispersants for SWCNTs is also important. In this study, trimethyl stearyl ammonium chloride (TMSAC), which is a cationic surfactant, was selected to prepare a Cu/SWCNT composite electroplating bath [19]. Cu/SWCNT composite films with relatively homogeneous SWCNT distribution were formed by electroplating. Cu/SWCNT composite films with homogeneously dispersed SWCNTs were also fabricated by electroless plating using a bath containing EDTA, glyoxylic acid, SDS+HPC (Fig. 1) [20]. References A. Oberlin, M. Endo and T. Koyama, J. Cryst. Growth, 32, 335 (1976).S. Iijima, Nature, 354, 56 (1991).S. Berber, Y.K. Kwon and D. Tomanek, Phys. Rev. B, 84, 4613 (2000).Z. Yao, C.L. Kane and C. Dekker, Phys. Rev. Lett., 84, 2941 (2000).M.F. Yu, O. Lourie, M.J. Dyer, K. Moloni, T.F. Kelly and R.S. Ruoff, Science, 287, 637 (2000).J.P. Lu, Phys. Rev. Lett., 79, 1297 (1997).S. Cho, K. Kikuchi, T. Miyazaki, K. Takagi, A. Kawasaki and T. Tsukada, Scr. Mater., 63, 375 (2010).A.K. Shukla, N. Nayan, S.V.S.N. Murty and S.C. Sharma, Mater. Sci. Eng. A, 560, 365 (2013).X.H. Chen, J.C. Peng, X.Q. Li, E.M. Deng, J.X. Wang and W.Z. Li, J. Mater. Sci. Lett., 20, 2057 (2001).S. Arai and M. Endo, Electrochem. Commun., 5, 797 (2003).S. Arai and M. Endo, Electrochem. Solid-State Lett., 7(3), C25 (2004).S. Arai and M. Endo, Electrochem. Commun., 7, 19 (2005).S. Arai, M. Endo and N. Kaneko, Carbon, 42, 641 (2004).S. Arai, T. Saito and M. Endo, J. Electrochem. Soc., 157(3), D147 (2010).S. Arai, T. Saito and M. Endo, J. Electrochem. Soc., 157(3), D127 (2010).S. Arai, Y. Suwa and M. Endo, J. Electrochem. Soc., 158(2), D49 (2011).S. Arai and T. Kanazawa, ECS J. Solid State Sci. Technol., 3, P201 (2014).S. Arai and T. Kanazawa, J. Electrochem. Soc., 162 (1), D68 (2015).T. Ogasawara, M. Shimizu and S. Arai, Proc. ADMETA Plus 2017, pp. 54-55 (2017).S. Arai, T. Osaki, M. Hirota and M. Uejima, Mater. Today Commun., 7, 101 (2016). Figure 1

Bioinspired one-step construction of hierarchical superhydrophobic surfaces for oil/water separation

It is imperative to develop efficient and environmentally friendly oil-spill cleanup materials to solve the problems raised by frequent oil spillages and industrial discharge of organic solvents. Here, we present a bioinspired one-step construction of hierarchical superhydrophobic surfaces on various commercial porous materials by immersing the materials into an alkaline aqueous mixture consisting of dopamine (DA) and dodecyltrimethoxysilane (DTMS). The self-polymerization of DA constructs the bumpy surfaces, while the DTMS coatings enhance the hydrophobicity of the surfaces. The combined use of both results in the hierarchical superhydrophobic surfaces. This surface modification of porous materials allows them as the potential candidates for collecting a wide variety of oils/organic solvents from water in a highly efficient, recyclable, and durable way. This approach proposes a general, yet green path for constructing superhydrophobic surfaces, which can be further adapted to prepare economic oil/organic solvents absorbents applied in the fields of oil/water separation, wastewater remediation, and organics recovery.

Sa1302 PROSPECTIVE EVALUATION OF DIGITAL SINGLE-OPERATOR CHOLANGIOSCOPE FOR DIAGNOSTIC AND THERAPEUTIC PROCEDURES

For difficult cases to diagnose or treat for biliary disease, peroral cholangioscopy (POCS) has clinical benefit. Recently, the digital single-operator cholangioscope (DSOCS) has become available. This system may allow diagnosis by direct visualization and allow performance of various therapeutic procedures. The aim of this study was to prospectively evaluate the clinical utility of the DSOCS for diagnostic and therapeutic procedures for biliary disease. Technical success was defined as successful visualization of target lesions in the biliary tract and performing forceps biopsy as a diagnostic procedure, and successfully performing treatment such as guidewire insertion for the area of interest, electrohydraulic lithotripsy (EHL), or migrated stent removal. Cholangioscopic findings were divided into two groups, according to previous reports: malignant findings: 1) irregular thick tortuous vessels, 2) easy oozing of blood, 3) irregular papillogranular surface, and 4) nodular elevated surface like a submucosal tumor, benign findings: 1) fine network of thin vessels and flat surface with or without shallow pseudodiverticula, 2) lower homogenyous papillogranular surface without primary masses, suggesting hyperplasia, 3) bumpy surface with or without pseudodiverticula, suggesting inflammation, and 4) white surface with convergence of folds, suggesting scar. The present study aimed at investigating diagnostic yield of the cholangioscopic findings and biopsy specimens. The present study was primarily aimed at investigating technical feasibility and safety of SPY-DS for diagnostic and therapeutic procedures. Secondly, the present study was aimed at investigating diagnostic yield such as sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of the cholangioscopic findings and biopsy specimens compared with that of the final diagnosis. A total of 55 consecutive patients were prospectively enrolled in this study; a diagnostic procedure was performed in 33 patients, and a therapeutic procedure was performed in 22 patients. The overall accuracy of visual findings was 93%, with a sensitivity of 83%, a specificity of 89%, PPV of 83%, and NPV of 100%. However, the overall accuracy of forceps biopsy was 89%, with a sensitivity, specificity, and PPV of 100%, and NPV of 90%. The overall technical success rate of therapeutic procedures such as selective guidewire insertion, EHL or migrated stent removal was 91% (20/22). Finally, adverse events were seen in two cases in diagnostic group, and were not seen in therapeutic group. Although additional cases and a randomized, controlled study with another cholangioscope are needed, diagnostic and therapeutic procedures using SPY-DS appear to be feasible and safe.