Primary renal leiomyosarcoma with a tumor thrombus in the inferior vena cava.

Introduction: We report a rare case of primary renal leiomyosarcoma with a tumor thrombus in the inferior vena cava.

Case Presentation: A 54-year-old woman presented with right flank pain and abdominal distension. Physical examination findings were unremarkable.

Yolk/Shell Colloidal Crystals Incorporating Movable Cores with Their Motion Controlled by an External Electric Field.

Yolk/shell particles composed of a submicrometer-sized movable core and a silica shell are promising building blocks for novel optical colloidal crystals, because the locations of cores in the shell compartment can be reversibly changed by using external stimuli. Two dimensional arrays of yolk/shell particles incorporating movable cores were prepared by a self-assembly method. The movable cores of colloidal crystals in water could be observed with an optical microscope under application of external electric field.

Imprinting Dimples on Narrowly Dispersed Polymeric Spheres by Heterocoagulation between Hard Polymer Particles and Soft Oil Droplets.

Golf ball-like particles having a number of dimples on their spherical surfaces were prepared by a combined method of heterocoagulation between hard polymer particles and soft silicone oil droplets, polymerization of the oil droplets, and dissolution of the polymer particles with tetrahydrofuran. In the heterocoagulation, polystyrene (PSt) particles of three different sizes were employed as hard particles. Distribution of dimples formed with small-sized PSt particles was less homogeneous than that with middle-sized PSt particles (MPS).

Magnetic field aligned assembly of nonmagnetic composite dumbbells in nanoparticle-based aqueous ferrofluid.

Monodisperse, nonmagnetic, asymmetrical composite dumbbells in a suspension of magnetic nanoparticles (ferrofluid) were aligned by application of an external magnetic field to the ferrofluid. The asymmetrical composite dumbbells were prepared by two-step soap-free emulsion polymerization consisting of the first polymerization to coat spherical silica cores with cross-linked poly(methyl methacrylate) (PMMA) shell and the second polymerization to protrude a polystyrene (PSt) lobe from the core-shell particles. A chain structure of nonmagnetic dumbbells oriented to the applied magnetic field was observed at nanoparticle content of 2.

Rattle-type colloidal crystals composed of spherical hollow particles containing an anisotropic, movable core.

Controls over the position and orientation of anisotropic particles in their assemblies are intriguing issues for functional colloidal crystals that are switchable with external fields such as electric and magnetic fields. We propose a novel approach for the fabrication of rattle-type colloidal crystals containing an anisotropic, movable core surrounded by a void space that allows rearrangement of the anisotropic core in the assembly. In the fabrication, multilayered core-shell particles composed of a titania core, polystyrene shell, and silica shell were prepared and then heated at 500 °C for 4 h to selectively remove the middle layer of polystyrene.

Membrane surface-enhanced Raman spectroscopy for sensitive detection of molecular behavior of lipid assemblies.

The dynamic properties of phospholipid (PL) membranes (phase state and phase transition) play crucial roles in biological systems. However, highly sensitive, direct analytical methods that shed light on the nature of lipids and their assemblies have not been developed to date. Here, we describe the analysis of PL-modified Au nanoparticles (Au@PL) using membrane surface-enhanced Raman spectroscopy (MSERS) and report the properties of the self-assembled PL membranes on the Au nanoparticle.

Dispersed-nanoparticle loading synthesis for monodisperse Au-titania composite particles and their crystallization for highly active UV and visible photocatalysts.

Submicrometer-sized amorphous titania spheres incorporating Au nanoparticles (NPs) were prepared in a one-pot synthesis consisting of a sol-gel reaction of titanium(IV) isopropoxide in the presence of chloroauric acid and a successive reduction with sodium borohydride in a mixed solvent of ethanol/acetonitrile. The synthesis was allowed to prepare monodisperse titania spheres that homogeneously incorporated Au NPs with sizes of ca. 7 nm.

Colloidal polarization of yolk/shell particles by reconfiguration of inner cores responsive to an external magnetic field.

Yolk/shell particles, which were hollow silica particles containing a movable magnetic silica core (MSC), were prepared by removing a middle polystyrene layer from multilayered particles of MSC/polystyrene/silica shell with heat treatment followed by a slight etching with a basic solution. An ac electric field was applied to the suspension of the yolk/shell particles to form pearl chains (1D structure) of yolk/shell particles. Observation with an optical microscope showed that the MSCs in the silica compartment of the pearl chains had a zigzag structure under the electric field.

A unified mechanism to quantitatively understand silica particle formation from tetraethyl orthosilicate in batch and semi-batch processes.

Factors for controlling sizes of silica particles formed in the hydrolysis and condensation of silicon alkoxides were examined in batch and semi-batch processes with our model previously proposed. Particle sizes in the particle formation were simulated for buffer systems to reduce time-variation in pH. Effectiveness of the buffer system to suppress time-variation in ionic strength was experimentally verified in a silicon alkoxide concentration range of 0.

Novel mini-reactor of silicone oil droplets for synthesis of morphology-controlled polymer particles.

Inside spaces of emulsion droplets can be used as mini-reactors for material synthesis. The novel application of sol-gel derived silicone oil droplets as mini-reactors was examined for the case of polymerization of styrene (St) and comonomers with the oil-soluble initiator 2,2'-azobis(2,4-dimethylvaleronitrile). Polydimethylsiloxane (PDMS) droplets prepared from dimethylsiloxane were used as the mini-reactors, in which the polymerization of St without comonomers was first conducted.

Directed orientation of asymmetric composite dumbbells by electric field induced assembly.

Assembly and directed orientation of anisotropic particles with an external ac electric field in a range from 1 kHz to 2 MHz were studied for asymmetric composite dumbbells incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere. The asymmetric composite dumbbells, which were composed of a polymethylmethacrylate (PMMA)-coated sphere (core-shell part) and a polystyrene (PSt) lobe, were synthesized with a soap-free emulsion polymerization to prepare PMMA-coated inorganic spheres and another soap-free emulsion polymerization to form a polystyrene (PSt) lobe from the PMMA-coated inorganic spheres. The composite dumbbells dispersed in water were directly observed with optical microscopy.

Anionic liposome template synthesis of raspberry-like hollow silica particle under ambient conditions with basic catalyst.

Hollow silica particle was obtained with a vesicle template synthesis in water under ambient conditions in the presence of ammonia. Biomimetic vesicles, liposomes were used, which consisted of a zwitterionic phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and a tiny amount of charged amphiphiles, hexadecylamine (HDA) or dicetylphosphate (DCP). Aggregation of silica occurred for DPPC or cationic DPPC/HDA liposome, whereas well-dispersed hollow silica particle could be obtained for anionic DPPC/DCP liposome.

Preparation of asymmetrically nanoparticle-supported, monodisperse composite dumbbells by protruding a smooth polymer bulge from rugged spheres.

A novel method is proposed to create asymmetrically nanoparticle-supported, monodisperse composite dumbbells. The method consists of the three steps of double soap-free emulsion polymerizations before and after a heterocoagulation. In the first step, soap-free emulsion polymerization was conducted to cover silica cores with cross-linked poly(methyl methacrylate) (PMMA) shells.

A durable PtRu/C catalyst with a thin protective layer for direct methanol fuel cells.

A methanol oxidation catalyst with improved durability in acidic environments is reported. The catalyst consists of PtRu alloy nanoparticles on a carbon support that were stabilized with a silane-coupling agent. The catalyst was prepared by reducing ions of Pt and Ru in the presence of a carbon support and the silane-coupling agent.

Electrolyte-added one-pot synthesis for producing monodisperse, micrometer-sized silica particles up to 7 microm.

A facile one-pot synthesis to produce micrometer-sized silica particles with low polydispersity was examined in a semibatch process where an ethanol solution of tetraethyl orthosilicate (TEOS) was continuously supplied to another ethanol solution of water and ammonia containing an electrolyte of LiCl, NaCl, or KCl. Supply rates of the TEOS solution was ranged with the water and electrolyte concentrations, which indicated that the addition of KCl at a low water concentration was effective to increase size of silica particles in a micrometer range. Highly monodisperse silica particles with an average size of 6.

Synthesis of hollow asymmetrical silica dumbbells with a movable inner core.

Hollow asymmetrical silica dumbbells containing a movable inner core were fabricated by a template-assisted method. Three different templates were employed for the fabrication of the hollow asymmetrical dumbbells. For the preparation of the first template, silica particles were uniformly covered with a cross-linked polymethylmethacrylate (PMMA) shell and the polymerization of styrene was conducted to induce a protrusion of polystyrene (PSt) from the PMMA shell.

Repetitive heterocoagulation of oppositely charged particles for enhancement of magnetic nanoparticle loading into monodisperse silica particles.

Oppositely charged particles were repetitively heterocoagulated to fabricate highly monodisperse magnetic silica particles with high loading of magnetic nanoparticles. Positively charged magnetic nanoparticles prepared by surface modification with N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TSA) were used to heterocoagulate with silica particles under basic conditions to give rise to negative silica surface charge and prevent the oxidation of the magnetic nanoparticles. The resultant particles of silica core homogeneously coated with the magnetic nanoparticles were further coated with thin silica layer with sodium silicate in order to enhance colloidal stability and avoid desorption of the magnetic nanoparticles from the silica cores.

Synthesis of highly monodisperse particles composed of a magnetic core and fluorescent shell.

Highly monodisperse particles composed of a magnetic silica core and fluorescent polymer shell were synthesized with a combined technique of heterocoagulation and soap-free emulsion polymerization. Prior to heterocoagulation, monodisperse, submicrometer-sized silica particles were prepared with the Stober method, and magnetic nanoparticles were prepared with a modified Massart method in which a cationic silane coupling agent of N-trimethoxysilylpropyl- N, N, N-trimethylammonium chloride was added just after coprecipitation of Fe (2+) and Fe (3+). The silica particles with negative surface potential were heterocoagulated with the magnetic nanoparticles with positive surface potential.

X-ray absorption of gold nanoparticles with thin silica shell.

Silica-coated gold (Au) nanoparticles were prepared and their morphological and X-ray absorption properties were investigated. These core-shell type nanoparticles are very stable in aqueous media and may be suitable for an X-ray contrast agent in biological systems. Transmission electron micrographs confirmed well-separated and relatively homogeneous morphology of the nanoparticles in highly concentrated colloids.

Preparation of micrometer-sized polymer particles with control of initiator dissociation during soap-free emulsion polymerization.

A previously proposed method of soap-free emulsion polymerization employing an amphoteric initiator, 2,2'-azobis [N-(2-carboxyethyl)-2-methylpropionamidine] tetrahydrate (VA-057), was extended to synthesize micrometer-sized polystyrene particles with low polydispersity in an acidic region of pH from 3.3 to 4.6.

Preparation and characterization of long-lived anode catalyst for direct methanol fuel cells.

Entry of direct methanol fuel cells into the market requires anode catalyst with stable activity. This paper presents a novel method for stabilizing the activity by immobilizing silica on the catalytic PtRu nanoparticles. Characterization was performed by STEM-EDX, XRD, and ICP.

Preparation of highly monodisperse poly(methyl methacrylate) particles incorporating fluorescent rhodamine 6G for colloidal crystals.

Soap-free emulsion polymerization was extended to preparation of monodisperse poly(methyl methacrylate) (PMMA) particles incorporating rhodamine 6G (R6G) fluorescent molecules. The polymerization was conducted in the presence of an anionic monomer, p-styrenesulfonate (NaSS), which improved dispersion stability of the polymer particles. NaSS concentrations was ranged up to 2 mol/m3 H2O in the polymerization at 0.

Direct coating of gold nanoparticles with silica by a seeded polymerization technique.

Gold nanoparticles prepared through a conventional citrate-reduction method were directly coated with silica by means of a seeded polymerization technique based on the Stöber method. The method required no surface modification. The addition of tetraethylorthosilicate and water prior to ammonia was found to be critical to obtain a proper coating.

Preparation and colloidal stability of monodisperse magnetic polymer particles.

A previously proposed method was examined for producing monodisperse, submicrometer-sized magnetic polymer particles. The method applies soap-free emulsion polymerization during which Fe3O4 magnetic nanoparticles are heterocoagulated onto precipitated polymer nuclei. To chemically fix the magnetic particles to the polymer nuclei, vinyl groups were introduced on the Fe3O4 particles in a preliminary surface modification reaction with methacryloxypropyltrimethoxysilane, and methacryloxypropyldimethoxysilane (MPDMS) was added to reaction systems of the soap-free emulsion polymerization.

Preparation and characterization of aqueous colloids of Pt-Ru nanoparticles.

A synthetic method for platinum-ruthenium (PtRu) nanoparticles in aqueous media is proposed. This method employs citric acid as a capping agent and NaBH(4) as a reducing agent with the aid of pH control. The number-averaged size of the PtRu nanoparticles was ca.