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1.
J Orthop Sci ; 29(2): 653-659, 2024 Mar.
Article in English | MEDLINE | ID: mdl-36858838

ABSTRACT

BACKGROUND: Peripheral nerve injuries are common and serious conditions. The effect of Neurotropin® (NTP), a nonprotein extract derived from the inflamed skin of rabbits inoculated with vaccinia virus, on peripheral nerve regeneration has not been fully elucidated. However, it has analgesic properties via the activation of descending pain inhibitory systems. Therefore, the current study aimed to determine the effects of NTP on peripheral nerve regeneration. METHODS: We examined axonal outgrowth of dorsal root ganglion (DRG) neurons using immunocytochemistry in vitro. In addition, nerve regeneration was evaluated functionally, electrophysiologically, and histologically in a rat sciatic nerve crush injury model in vivo. Furthermore, gene expression of neurotrophic factors in the injured sciatic nerves and DRGs was evaluated. RESULTS: In the dorsal root ganglion neurons in vitro, NTP promoted axonal outgrowth at a concentration of 10 mNU/mL. Moreover, the systemic administration of NTP contributed to the recovery of motor and sensory function at 2 weeks, and of sensory function, nerve conduction velocity, terminal latency, and axon-remyelination 4 weeks after sciatic nerve injury. In the gene expression assessment, insulin-like growth factor 1 and vascular endothelial growth factor expressions were increased in the injured sciatic nerve 2 days postoperatively. CONCLUSIONS: Therefore, NTP might be effective in not only treating chronic pain but also promoting peripheral nerve regeneration after injury.


Subject(s)
Crush Injuries , Peripheral Nerve Injuries , Polysaccharides , Rats , Animals , Rabbits , Peripheral Nerve Injuries/drug therapy , Vascular Endothelial Growth Factor A , Nerve Regeneration/physiology , Sciatic Nerve/surgery , Sciatic Nerve/injuries
2.
Bone Jt Open ; 3(3): 261-267, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35311581

ABSTRACT

AIMS: Low-energy distal radius fractures (DRFs) are the most common upper arm fractures correlated with bone fragility. Vitamin D deficiency is an important risk factor associated with DRFs. However, the relationship between DRF severity and vitamin D deficiency is not elucidated. Therefore, this study aimed to identify the correlation between DRF severity and serum 25-hydroxyvitamin-D level, which is an indicator of vitamin D deficiency. METHODS: This multicentre retrospective observational study enrolled 122 female patients aged over 45 years with DRFs with extension deformity. DRF severity was assessed by three independent examiners using 3D CT. Moreover, it was categorized based on the AO classification, and the degree of articular and volar cortex comminution was evaluated. Articular comminution was defined as an articular fragment involving three or more fragments, and volar cortex comminution as a fracture in the volar cortex of the distal fragment. Serum 25-hydroxyvitamin-D level, bone metabolic markers, and bone mineral density (BMD) at the lumbar spine, hip, and wrist were evaluated six months after injury. According to DRF severity, serum 25-hydroxyvitamin-D level, parameters correlated with bone metabolism, and BMD was compared. RESULTS: The articular comminuted group (n = 28) had a significantly lower median serum 25-hydroxyvitamin-D level than the non-comminuted group (n = 94; 13.4 ng/ml (interquartile range (IQR) 9.8 to 17.3) vs 16.2 ng/ml (IQR 12.5 to 20.4); p = 0.005). The AO classification and volar cortex comminution were not correlated with the serum 25-hydroxyvitamin-D level. Bone metabolic markers and BMD did not significantly differ in terms of DRF severities. CONCLUSION: Articular comminuted DRF, referred to as AO C3 fracture, is significantly associated with low serum 25-hydroxyvitamin-D levels. Therefore, vitamin D3 supplementation for vitamin D deficiency might prevent articular comminuted DRFs. Nevertheless, further studies must be conducted to validate the results of the current study. Cite this article: Bone Jt Open 2022;3(3):261-267.

3.
J Wrist Surg ; 8(5): 352-359, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31579542

ABSTRACT

Background Ulnar shortening osteotomy of the diaphysis is a common and effective surgical procedure for ulnar abutment syndrome. However, this procedure has some disadvantages, such as a long period until union and a relatively high nonunion rate. To overcome these disadvantages, we have developed distal ulnar metaphyseal wedge osteotomy. The purpose of this article is to describe the technique and to report its clinical results. Patients and Methods Distal ulnar metaphyseal wedge osteotomy consists of resection of the wedge fragment at the distal ulnar metaphysis, compressing the distal fragment of the ulna toward the radial-proximal direction and fixation with a Herbert type headless screw. We performed this procedure for 58 patients with ulnar abutment syndrome, and the clinical data of 43 patients who were followed for > 6 months were analyzed. We evaluated range of motion, grip strength, and HAND20 which is a validated subjective scoring system in Japan. Results All patients experienced relief from their ulnar wrist pain, and bone union was achieved within an average of 2.6 months. The range of dorsiflexion improved from 63° preoperatively to 69° postoperatively, grip strength compared with the contralateral hand improved from 77% preoperatively to 87% postoperatively, and HAND20 improved from 41.3 points preoperatively to 22.4 points postoperatively. Discussion This procedure has advantages especially in early bone union. This procedure should be taken into consideration as one of the options to treat ulnar abutment syndrome.

4.
Int J Mol Sci ; 19(5)2018 May 07.
Article in English | MEDLINE | ID: mdl-29735961

ABSTRACT

Ultra-fine bubbles (<200 nm in diameter) have several unique properties and have been tested in various medical fields. The purpose of this study was to investigate the effects of oxygen ultra-fine bubbles (OUBs) on a sciatic nerve crush injury (SNC) model rats. Rats were intraperitoneally injected with 1.5 mL saline, OUBs diluted in saline, or nitrogen ultra-fine bubbles (NUBs) diluted in saline three times per week for 4 weeks in four groups: (1) control, (sham operation + saline); (2) SNC, (crush + saline); (3) SNC+OUB, (crush + OUB-saline); (4) SNC+NUB, (crush + NUB-saline). The effects of the OUBs on dorsal root ganglion (DRG) neurons and Schwann cells (SCs) were examined by serial dilution of OUB medium in vitro. Sciatic functional index, paw withdrawal thresholds, nerve conduction velocity, and myelinated axons were significantly decreased in the SNC group compared to the control group; these parameters were significantly improved in the SNC+OUB group, although NUB treatment did not affect these parameters. In vitro, OUBs significantly promoted neurite outgrowth in DRG neurons by activating AKT signaling and SC proliferation by activating ERK1/2 and JNK/c-JUN signaling. OUBs may improve nerve dysfunction in SNC rats by promoting neurite outgrowth in DRG neurons and SC proliferation.


Subject(s)
Microbubbles/therapeutic use , Oxygen/therapeutic use , Sciatic Nerve/drug effects , Sciatic Nerve/injuries , Sciatic Neuropathy/drug therapy , Animals , Apoptosis/drug effects , Cells, Cultured , Ganglia, Spinal/drug effects , Ganglia, Spinal/physiopathology , Male , Nerve Crush , Nerve Regeneration/drug effects , Oxygen/administration & dosage , Rats, Wistar , Schwann Cells/drug effects , Schwann Cells/pathology , Sciatic Nerve/physiopathology , Sciatic Neuropathy/physiopathology
5.
Int J Mol Sci ; 19(2)2018 Feb 08.
Article in English | MEDLINE | ID: mdl-29419802

ABSTRACT

Neurotropin® (NTP), a non-protein extract of inflamed rabbit skin inoculated with vaccinia virus, is clinically used for the treatment of neuropathic pain in Japan and China, although its effect on peripheral nerve regeneration remains to be elucidated. The purpose of this study was to investigate the effects of NTP on Schwann cells (SCs) in vitro and in vivo, which play an important role in peripheral nerve regeneration. In SCs, NTP upregulated protein kinase B (AKT) activity and Krox20 and downregulated extracellular signal-regulated kinase1/2 activity under both growth and differentiation conditions, enhanced the expression of myelin basic protein and protein zero under the differentiation condition. In a co-culture of dorsal root ganglion neurons and SCs, NTP accelerated myelination of SCs. To further investigate the influence of NTP on SCs in vivo, lysophosphatidylcholine was injected into the rat sciatic nerve, leading to the focal demyelination. After demyelination, NTP was administered systemically with an osmotic pump for one week. NTP improved the ratio of myelinated axons and motor, sensory, and electrophysiological function. These findings reveal novel effects of NTP on SCs differentiation in vitro and in vivo, and indicate NTP as a promising treatment option for peripheral nerve injuries and demyelinating diseases.


Subject(s)
Cell Differentiation/drug effects , Demyelinating Diseases/etiology , Demyelinating Diseases/metabolism , Lysophosphatidylcholines/adverse effects , Polysaccharides/pharmacology , Remyelination/drug effects , Schwann Cells/cytology , Schwann Cells/physiology , Animals , Cell Proliferation/drug effects , Cells, Cultured , Demyelinating Diseases/drug therapy , Disease Models, Animal , MAP Kinase Signaling System/drug effects , Nerve Regeneration , Proto-Oncogene Proteins c-akt/metabolism , Rats , Schwann Cells/drug effects
6.
Acta Biomater ; 53: 250-259, 2017 04 15.
Article in English | MEDLINE | ID: mdl-28179161

ABSTRACT

Peripheral nerve injury is one of common traumas. Although injured peripheral nerves have the capacity to regenerate, axon regeneration proceeds slowly and functional outcomes are often poor. Pharmacological enhancement of regeneration can play an important role in increasing functional recovery. In this study, we developed a novel electrospun nanofiber sheet incorporating methylcobalamin (MeCbl), one of the active forms of vitamin B12 homologues, to deliver it enough locally to the peripheral nerve injury site. We evaluated whether local administration of MeCbl at the nerve injury site was effective in promoting nerve regeneration. Electrospun nanofiber sheets gradually released MeCbl for at least 8weeks when tested in vitro. There was no adverse effect of nanofiber sheets on function in vivo of the peripheral nervous system. Local implantation of nanofiber sheets incorporating MeCbl contributed to the recovery of the motor and sensory function, the recovery of nerve conduction velocity, and the promotion of myelination after sciatic nerve injury, without affecting plasma concentration of MeCbl. STATEMENT OF SIGNIFICANCE: Methylcobalamin (MeCbl) is a vitamin B12 analog and we previously reported its effectiveness in axonal outgrowth of neurons and differentiation of Schwann cells both in vitro and in vivo. Here we estimated the effect of local administered MeCbl with an electrospun nanofiber sheet on peripheral nerve injury. Local administration of MeCbl promoted functional recovery in a rat sciatic nerve crush injury model. These sheets are useful for nerve injury in continuity differently from artificial nerve conduits, which are useful only for nerve defects. We believe that the findings of this study are relevant to the scope of your journal and will be of interest to its readership.


Subject(s)
Guided Tissue Regeneration/instrumentation , Nanofibers/chemistry , Nerve Regeneration/drug effects , Peripheral Nerve Injuries/pathology , Peripheral Nerve Injuries/therapy , Tissue Scaffolds , Vitamin B 12/analogs & derivatives , Animals , Combined Modality Therapy/instrumentation , Combined Modality Therapy/methods , Diffusion , Drug Implants/administration & dosage , Drug Implants/chemical synthesis , Electroplating/methods , Equipment Design , Male , Membranes, Artificial , Nanocapsules/chemistry , Nanocapsules/ultrastructure , Nanofibers/ultrastructure , Nerve Regeneration/genetics , Rats , Rats, Wistar , Rotation , Treatment Outcome , Vitamin B 12/administration & dosage , Vitamin B 12/chemistry
7.
Biologicals ; 44(4): 206-211, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27233579

ABSTRACT

Neuropathic pain caused by nerve damage in the central and/or peripheral nervous systems is a refractory disorder and the management of such chronic pain has become a major issue. Neurotropin is a drug widely used in Japan and China to treat chronic pain. Although Neurotropin has been demonstrated to suppress chronic pain through the descending pain inhibitory system, the mechanism of analgesic action in the peripheral nervous system remains to be elucidated. In this study, we investigated the local effects of Neurotropin on peripheral nerve damage in a chronic constriction injury (CCI) model. Neurotropin reduced mRNA expressions of IL-1ß, IL-6, and TNF-α in the sciatic nerve 1 day after the injury. Activation of Erk was also inhibited locally in the Neurotropin treatment group. Since Erk activation results in demyelination along with dedifferentiation of Schwann cells, we investigated the expression level of myelin basic protein. Five days after the injury, Neurotropin attenuated the downregulation of myelin basic protein in the sciatic nerve in the CCI model. Local effects of Neurotropin around the injury site may result in discovery of new treatments for not only neuropathic pain but also demyelinating diseases and peripheral nervous system injury.


Subject(s)
Cytokines/genetics , Demyelinating Diseases/prevention & control , Polysaccharides/pharmacology , Sciatic Nerve/injuries , Analgesics/pharmacology , Animals , Blotting, Western , Chronic Disease , Constriction , Cytokines/metabolism , Demyelinating Diseases/etiology , Disease Models, Animal , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , Gene Expression/drug effects , Inflammation Mediators/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Interleukin-6/genetics , Interleukin-6/metabolism , Mice, Inbred C57BL , Microscopy, Fluorescence , Neuralgia/prevention & control , Peripheral Nerve Injuries/complications , Reverse Transcriptase Polymerase Chain Reaction , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
8.
Front Cell Neurosci ; 9: 298, 2015.
Article in English | MEDLINE | ID: mdl-26300733

ABSTRACT

Schwann cells (SCs) are constituents of the peripheral nervous system. The differentiation of SCs in injured peripheral nerves is critical for regeneration after injury. Methylcobalamin (MeCbl) is a vitamin B12 analog that is necessary for the maintenance of the peripheral nervous system. In this study, we estimated the effect of MeCbl on SCs. We showed that MeCbl downregulated the activity of Erk1/2 and promoted the expression of the myelin basic protein in SCs. In a dorsal root ganglion neuron-SC coculture system, myelination was promoted by MeCbl. In a focal demyelination rat model, MeCbl promoted remyelination and motor and sensory functional regeneration. MeCbl promoted the in vitro differentiation of SCs and in vivo myelination in a rat demyelination model and may be a novel therapy for several types of nervous disorders.

9.
J Hazard Mater ; 266: 174-81, 2014 Feb 15.
Article in English | MEDLINE | ID: mdl-24412625

ABSTRACT

Al-substituted 11Å-tobermorite was formed by alkaline hydrothermal treatment of blast furnace slag with sodium silicate added at 180°C for 2-48 h. Effects of the hydrothermal treatment time were characterized by XRD, SEM, and isothermal adsorption of N2. Sorption characteristics of the obtained samples were examined for Cs(+) and Sr(2+). The sample obtained by hydrothermal treatment for 48 h (HT-48 h) consisted of calcium silicate hydrate (C-S-H), and Al-substituted 11Å-tobermorite. The HT-48 h showed the highest performance for Cs(+) and Sr(2+) selectivity in the presence of Na(+). The interlayer Na(+) of Al-substituted 11Å-tobermorite and surface Ca(2+) played an important role in selective Cs(+) and Sr(2+).


Subject(s)
Calcium Compounds/chemistry , Cesium/chemistry , Industrial Waste , Silicates/chemistry , Strontium/chemistry , Adsorption , Sodium/chemistry
10.
Biochem Biophys Res Commun ; 443(3): 871-5, 2014 Jan 17.
Article in English | MEDLINE | ID: mdl-24342621

ABSTRACT

Methylcobalamin (MeCbl) is a vitamin B12 analog that has some positive effects on peripheral nervous disorders. Although some previous studies revealed the effects of MeCbl on neurons, its effect on the muscle, which is the final target of motoneuron axons, remains to be elucidated. This study aimed to determine the effect of MeCbl on the muscle. We found that MeCbl promoted the proliferation and migration of C2C12 myoblasts in vitro and that these effects are mediated by the Erk1/2 signaling pathway without affecting the activity of the Akt signaling pathway. We also demonstrated that MeCbl inhibits C2C12 cell apoptosis during differentiation. Our results suggest that MeCbl has beneficial effects on the muscle in vitro. MeCbl administration may provide a novel therapeutic approach for muscle injury or degenerating muscle after denervation.


Subject(s)
Apoptosis/drug effects , Cell Movement/drug effects , MAP Kinase Signaling System/drug effects , Myoblasts/cytology , Myoblasts/enzymology , Vitamin B 12/analogs & derivatives , Animals , Cell Differentiation/drug effects , Cell Line , Cell Proliferation/drug effects , Mice , Myoblasts/drug effects , Phosphorylation/drug effects , Vitamin B 12/pharmacology
11.
Langmuir ; 29(23): 6784-9, 2013 Jun 11.
Article in English | MEDLINE | ID: mdl-23701360

ABSTRACT

The photoinduced wettabilities of water, n-hexadecane, dodecane, and n-heptane on a flat TiO2 surface prepared by a sol-gel method-based coating were investigated. An amphiphilic surface produced by UV irradiation exhibited underwater superoleophobicity with an extremely high static oil contact angle (CA) of over 160°. The TiO2 surface almost completely repelled the oil droplet in water. A robust TiO2 surface with no fragile nanomicrostructure was fabricated on a Ti mesh with a pore size of approximately 150 µm. The fabricated mesh was found to be applicable as an oil/water separation filter.


Subject(s)
Alkanes/chemistry , Heptanes/chemistry , Plant Oils/chemistry , Titanium/chemistry , Water/chemistry , Hydrophobic and Hydrophilic Interactions , Particle Size , Photochemical Processes , Surface Properties , Wettability
12.
Adv Mater ; 23(48): 5750-4, 2011 Dec 22.
Article in English | MEDLINE | ID: mdl-22069179

ABSTRACT

A coaxial nanohybrid consisting of a single-walled carbon nanotube (SWCNT), fullerodendron, and SiO(2) shows high-efficiency light-driven hydrogen evolution from water. Upon visible light irradiation, SWCNT/fullerodendron/SiO(2) coaxial nanohybrid shows hydrogen evolution activity in the presence of methyl viologen (MV(2+)), benzyldihydronicotinamide (BNAH), and a colloidal polyvinyl alcohol(PVA)-Pt.


Subject(s)
Fullerenes/chemistry , Hydrogen/chemistry , Nanocomposites/chemistry , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Photosensitizing Agents/pharmacology , Silicon Dioxide/chemistry , Carbon/chemistry , Catalysis , Microscopy, Electron, Scanning/methods , Models, Chemical , Molecular Structure , Phase Transition , Spectroscopy, Near-Infrared/methods , Time Factors , Water/chemistry
13.
J Colloid Interface Sci ; 362(1): 188-93, 2011 Oct 01.
Article in English | MEDLINE | ID: mdl-21741658

ABSTRACT

W-doped TiO(2) nanofibers with various compositions (W/Ti: 2-8%) were fabricated by the electrospinning method from respective precursor solutions containing tungsten(V) pentaethoxide, titanium tetraisopropoxide (TTIP), and polyvinylpyrrolidone (PVP), followed with calcination at 550 °C. Morphological and structural characteristics of these nanofibers were studied with SEM, XRD and XPS. W-doping inhibited the crystal growth and anatase-to-rutile transformation of TiO(2) nanofibers. W-doped TiO(2) nanofiber mats showed good photocatalytic oxidation abilities for acetone. Obvious color change from white to blue of mats during the photocatalysis process can be detected by naked eyes, which provides a good way in detection of pollutants in indoor air, especially for the volatile organic compounds (VOCs).


Subject(s)
Nanofibers/chemistry , Titanium/chemistry , Volatile Organic Compounds/analysis , Nanofibers/ultrastructure , Oxidation-Reduction , Photochemical Processes , Spectrophotometry, Ultraviolet
14.
Langmuir ; 26(14): 11628-30, 2010 Jul 20.
Article in English | MEDLINE | ID: mdl-20552954

ABSTRACT

This Letter describes a new fabrication process for superhydrophilic-superhydrophobic patterns on a TiO(2) surface using a combination of an inkjet technique and the site-selective decomposition of a self-assembled monolayer (SAM) by a photocatalytic reaction under UV irradiation. To induce high surface wettability, we carried out simple calcination of a Ti substrate. The substrate was thus oxidized to titanium oxide and had a vortex-like rough morphology, which was suitable for the formation of wettability patterns. Furthermore, the substrate can be regenerated after elimination of the superhydrophilic-superhydrophobic patterns by the photocatalytic decomposition of TiO(2) using UV irradiation, and the patterns are deposited again. The renewed surface that we created had a wettability pattern that was different from the preceding pattern. This process is based on a TiO(2) surface and should offer a renewable, resource-saving, and environmentally friendly methodology for the formation of wettability patterns.


Subject(s)
Hydrophobic and Hydrophilic Interactions , Printing , Titanium/chemistry , Ink , Surface Properties , Ultraviolet Rays , Water/chemistry
15.
Langmuir ; 25(13): 7226-8, 2009 Jul 07.
Article in English | MEDLINE | ID: mdl-19563218

ABSTRACT

A renewable superhydrophobic-superhydrophilic pattern with a minimum dimension of 50 microm is prepared from octadecyltrimethoxysilane self-assembled monolayer-covered superhydrophobic Al2O3 overlayers on a superhydrophilic TiO2 surface via self-assembly and calcination of boehmite (AlOOH.nH2O) particles. The resulting Al2O3 layer plays dual roles as a superhydrophobic layer and as a UV-blocking layer for the underlying TiO2.


Subject(s)
Aluminum Oxide/chemistry , Titanium/chemistry , Water/chemistry , Crystallization , Surface Properties
16.
Chem Asian J ; 4(6): 984-988, 2009 Jun 02.
Article in English | MEDLINE | ID: mdl-19322804

ABSTRACT

A fabrication process for superhydrophilic-superhydrophilic patterns on titanium substrates prepared through a combination of an ink-jet technique and site-selective decomposition of a self-assembled monolayer (SAM) by a TiO(2) photocatalyst under UV irradiation is described. We demonstrate that the prepared titanium substrate is applicable as an offset printing plate with high resolution (133 and 150 lines per inch). Furthermore, the superhydrophilic-superhydrophobic patterns on the substrate can be deposited repeatedly after elimination of the patterns by photocatalytic decomposition of TiO(2) under UV irradiation. A second printed image with the renewed substrate showed no significant difference in image quality compared with the initial image.


Subject(s)
Printing , Titanium/chemistry , Catalysis , Hydrophobic and Hydrophilic Interactions , Ultraviolet Rays , X-Ray Diffraction
17.
Environ Sci Technol ; 42(22): 8547-51, 2008 Nov 15.
Article in English | MEDLINE | ID: mdl-19068846

ABSTRACT

Highly ordered TiO2 nanotube array prepared by electrochemical anodization generates considerable interest as a practical air purifier, since a nanotube array can form a TiO2 film with a porous surface and straight gas diffusion channel, simultaneously reserving enough geometric thickness. Here, we reported on the application of highly ordered TiO2 nanotube arrays with different lengths for degradation of gaseous acetaldehyde pollutants in air. The results showed that increasing the lengths of nanotube arrays within a certain range could significantly improve the degradation rate of acetaldehyde molecules. The main product of acetaldehyde degradation was detected to be CO2, which indicated that the mineralization of acetaldehyde molecules was the major process in this photocatalytic reaction. When compared with a P25 TiO2 nanoparticulate film with similar thickness and geometric area, in the initial degradation of acetaldehyde, the nanotube array did not show obvious superiority. However, in the subsequent degradation, the nanotube array demonstrated an enhanced photocatalytic activity. It was suggested that this enhancement resulted from the special infrastructure of the nanotube array, which was favorable for the diffusion of intermediates and the reduced deactivation of photocatalyst in the photocatalytic reaction.


Subject(s)
Acetaldehyde/chemistry , Nanotubes/chemistry , Photochemistry/methods , Titanium/chemistry , Catalysis , Electrochemistry , Nanotubes/ultrastructure
18.
Langmuir ; 23(22): 10916-9, 2007 Oct 23.
Article in English | MEDLINE | ID: mdl-17892314

ABSTRACT

We report here the use of a layer-by-layer assembly technique to prepare novel TiO2 heterogeneous nanostructures in which anatase nanoparticles are assembled on rutile nanorods. The preparation includes assembling anatase nanoparticle multilayers on rutile nanorods via electrostatic deposition using poly(sodium 4-styrene sulfonate) as a bridging or adhesion layer, followed by burning off the polymeric material via calcination. The composition of the heterogeneous nanostructures (i.e., the anatase-to-rutile ratio) can be tuned conveniently by controlling the experimental conditions of the layer-by-layer assembly. It was found that, with the optimum preparation conditions, the heterogeneous nanostructures showed better photocatalytic activity for decomposing gaseous acetaldehyde than either the original anatase nanoparticles or the rutile nanorods. This is discussed on the basis of the synergistic effect of the existence of both rutile and anatase in the heterogeneous nanostructure.

19.
Chem Commun (Camb) ; (46): 4949-51, 2007 Dec 14.
Article in English | MEDLINE | ID: mdl-18361379

ABSTRACT

A transparent superhydrophobic TiO2 film, prepared by spin-coating a TiO2 slurry on a glass substrate and modifying the resultant TiO2 film with fluoroalkylsilane molecules, was patterned by illumination with ultraviolet light through a photomask, producing a superhydrophobic/superhydrophilic surface micropattern with very small superhydrophilic areas, which we were able to selectively fill with alginate hydrogel.


Subject(s)
Titanium/chemistry , Alginates/chemistry , Catalysis , Chemical Phenomena , Chemistry, Physical , Hydrogels/chemistry , Microscopy, Electron, Scanning , Silanes/chemistry , Surface Properties , Titanium/radiation effects , Ultraviolet Rays
20.
Nanotechnology ; 18(7): 075605, 2007 Feb 21.
Article in English | MEDLINE | ID: mdl-21730507

ABSTRACT

Heat treatment of various compositions of AgNO(3)-doped polyvinylpyrrolidone (PVP) composite nanofibres fabricated by electrospinning produced two kinds of silver species: (i) Ag nanoparticles dispersed in PVP nanofibres, when the loading of AgNO(3) was 5 wt%, and (ii) a net-like silver nanofibre film when the loading of AgNO(3) was five times greater than that of PVP in the composite nanofibres. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible absorption spectroscopy, FT-IR spectra, powder x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) were used to characterize the silver nanoparticles and nanofibres. The formation mechanisms are discussed based on the redox reaction between AgNO(3) and PVP during heat treatment; essentially, the weight ratios of AgNO(3) to PVP determined the types of morphologies, from Ag nanoparticles to silver nanofibre film. The present results may find some potential application in the design of new composite materials in the dielectric and electronics areas.

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