Search

Abstract Single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate in cytotoxic levels within organs of various animal models and cell types, which emerge as a wide range of promising biomedical imaging. Septic encephalopathy (SE) is an early sign of sepsis and associated with an increased rate of morbidity and mortality. Microglia activation plays an important role in neuroinflammation, which contributes to neuronal damage. Inhibition of microglia activation may have therapeutic benefits, which can alleviate the progression of neurodegeneration. Therefore, we investigated the functional changes of mice microglia cell lines pre-treated with or without lipopolysaccharide (LPS) induced by SWNHs. To address this question, the research about direct role of SWNHs on the growth, proliferation, and apoptosis of microglia cell lines in mice (N9 and BV2) pre-treated with or without LPS had been performed. Our results indicate that the particle diameter of SWNHs in water is between 342 to 712 nm. The images in scanning electron microscope showed that SWNHs on polystyrene surface are individual particles. LPS induced activation of mice microglia, promoted its growth and proliferation, and inhibited its apoptosis. SWNHs inhibited proliferation, delayed mitotic entry, and promoted apoptosis of mice microglia cells. The effects followed gradually increasing cultured time and concentrations of SWNHs, especially in cells pre-treated with LPS. SWNHs induced a significantly increase in G1 phase and inhibition of S phase of mice microglia cells in a dose-manner dependent of SWNHs, especially in cells pre-treated with LPS. The transmission electron microscope images showed that individual spherical SWNH particles smaller than 100 nm in diameters were localized inside lysosomes of mice microglia cells. SWNHs inhibited mitotic entry, growth and proliferation of mice microglia cells, and promoted its apoptosis, especially in cells pre-treated with LPS. SWNHs inhibited expression of Sirt3 and energy metabolism related with Sirt3 in mice microglia cells in a dose-dependent manner, especially in cells pre-treated with LPS. The role of SWNHs on mice microglia was implicating Sirt3 and energy metabolism associated with it.

The electrosynthesis, isolation and characterization of reaction products between [C.sub.60.sup.2-] and benzyl bromide in PhCN are reinvestigated. The visible and near-infrared spectra of the monoanion and dianion of 1,2-[(PhC[H.sub.2]).sub.2][C.sub.60] are described.

A Y-Ni alloy and graphite rod has been used to produce single-wall carbon nanotubes (SWCNTs) with 50%-70% purity. Experiments demonstrate that SWCNTs produced with yttrium-nickel as a catalyst have the same structures as those obtained with Co-Ni catalyst.

A stable mixed low-dimensional nanomaterial consisting of Mo[S.sub.2] inorganic nanoribbons encapsulated in carbon nanotubes (nanoburritos) is prepared and the method is also used for preparing nanoburritos composed of ultranarrow transition-metal chalcogenide nanoribbons and carbon nanotubes. The edges of the Mo[S.sub.2] nanoribbons are identified as zigzag-shaped by using both high-resolution transmission electron microscopy and density functional theory calculations.

The gate-controlled rectification behavior in [C.sub.70] at the rate single-walled carbon nanotube (SWNT) networks is reported at room temperature in air. The current rectification characteristics have resulted from highly asymmetric Schottky barriers between semiconducting peapods and the S/D electrodes.

The long fibers of high purity single-walled carbon nanotubes (SWNTs) are directly synthesized macroscopically by the modified arc discharge method. The purity of the SWNT in fibers are evaluated by scanning electron microscopy, thermogravimetric analysis, and Raman spectroscopy.

Study is conducted to demonstrate that iodine atoms/ions dope at the intratubular position in the [C.sub.60] peapods. It is found that the heating the iodine-doped peapod at 550 degree C induces the transformation of [C.sub.60] into a tubular structure.

Sn@C nanocomposites are of great interest for use as high-capacity anode materials for lithium ion batteries (LIBs). In this paper, we describe a facile arc-discharge method to produce carbon-coated tin-nanostructured composites by reducing SnO2 in CO gases. Metallic Sn species are homogeneously coated in dual carbonaceous layers and effectively confined within the nanostructures. The resulting composites are used as anode materials for LIBs and exhibit excellent cyclability of over 200 cycles along with high specific capacities (1220 mA h g−1 at a current density of 372 mA g−1 and 600 mA h g−1 at high current densities up to 3720 mA g−1). By tuning the content of tin precursor, a unique morphology conversion from spherical Sn nanoparticles embedded in the carbon framework to Sn rods that can regulate the electrochemical property has been observed. Most of all, such a Sn@C composite is a very promising anode material for LIBs for practical applications. [ABSTRACT FROM AUTHOR]

Single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate in cytotoxic levels within organs of various animal models and cell types, which emerge as a wide range of promising biomedical imaging. Septic encephalopathy (SE) is an early sign of sepsis and associated with an increased rate of morbidity and mortality. Microglia activation plays an important role in neuroinflammation, which contributes to neuronal damage. Inhibition of microglia activation may have therapeutic benefits, which can alleviate the progression of neurodegeneration. Therefore, we investigated the functional changes of mice microglia cell lines pre-treated with or without lipopolysaccharide (LPS) induced by SWNHs. To address this question, the research about direct role of SWNHs on the growth, proliferation, and apoptosis of microglia cell lines in mice (N9 and BV2) pre-treated with or without LPS had been performed. Our results indicate that the particle diameter of SWNHs in water is between 342 to 712 nm. The images in scanning electron microscope showed that SWNHs on polystyrene surface are individual particles. LPS induced activation of mice microglia, promoted its growth and proliferation, and inhibited its apoptosis. SWNHs inhibited proliferation, delayed mitotic entry, and promoted apoptosis of mice microglia cells. The effects followed gradually increasing cultured time and concentrations of SWNHs, especially in cells pre-treated with LPS. SWNHs induced a significantly increase in G1 phase and inhibition of S phase of mice microglia cells in a dose-manner dependent of SWNHs, especially in cells pre-treated with LPS. The transmission electron microscope images showed that individual spherical SWNH particles smaller than 100 nm in diameters were localized inside lysosomes of mice microglia cells. SWNHs inhibited mitotic entry, growth and proliferation of mice microglia cells, and promoted its apoptosis, especially in cells pre-treated with LPS. SWNHs inhibited expression of Sirt3 and energy metabolism related with Sirt3 in mice microglia cells in a dose-dependent manner, especially in cells pre-treated with LPS. The role of SWNHs on mice microglia was implicating Sirt3 and energy metabolism associated with it. [ABSTRACT FROM AUTHOR]

We report novel graphene nanoribbon (GNR)/semiconductor nanowire (SNW) heterojunction light-emitting diodes (LEDs) for the first time. In the device, the GNR and SNW have face-to-face contact with each other, which has the merits of a larger active region and smaller series resistance, and may benefit high-efficiency electroluminescence and even electrically driven lasers in the future. ZnO, CdS, and CdSe NWs were employed in our case. At forward biases, the GNR/SNW heterjunction LEDs could emit light with wavelengths varying from ultraviolet (380 nm) to green (513 nm) to red (705 nm), which were determined by the band-gaps of the involved SNWs. The mechanism of light emitting for the GNR/SNW heterojunction LEDs was discussed. Our work opens new routes to developing diverse graphene-based nano-optoelectronic devices, which are basic components in integrated optoelectronic system. Besides, the novel graphene/SNW hybrid devices, by taking advantage of both graphene and SNW, will be promising candidates for use in applications such as high-sensitivity sensor and transparent flexible devices in the future. [ABSTRACT FROM AUTHOR]

Layered tungsten disulfide nanostructures are of both fundamental and technological interest. The widths of currently synthesized WS2ribbons are in the microscale. By using single-walled carbon nanotubes and double-walled carbon nanotubes as templates, we fabricate WS2nanoribbons with smooth zigzag edges and uniform widths down to 1–3 nm and layer numbers down to 1–3, dependent on the nanotube diameter. Although bulk WS2is a nonmagnetic semiconductor, the ultra-narrow free-standing zigzag-edged WS2nanoribbons turn out to be magnetic or nonmagnetic metals depending on the edge passivation way according to our first-principles calculations, whereas the ultra-narrow armchair-edged WS2nanoribbons remain nonmagnetic semiconductors with a narrow gap. [ABSTRACT FROM AUTHOR]

A series of monogadolinium metallofullerenes of Gd@C80, Gd@C82 (II), and Gd@C82 (HI) was produced and isolated by an efficient multi-stage HPLC method for the first time. All these newly isolated metallofullerenes were characterized by LD-TOF mass spectrometry and Vis-NIR absorptitm spectroscopy. Their possible molecular symmetries are discussed according to their HPLC retention times and absorption spectra. [ABSTRACT FROM AUTHOR]

The compound growth of single-walled carbon nanotube (SWCNT) and multiwalled carbon nanotube (MWCNT), which formed a nanotube cable, was achieved by the chemical vapor deposition of natural gas on an Fe catalyst supported on SiO[sub2]-Al[sub2]O[sub3] hybrid materials at 950°C. The microstructure of nanotubes was characterized by high-resolution transmission electron microscopy (HRTEM). The SWCNTs encapsulated inside MWCNTs can be two, three, or even more in quantity with a diameter range from 1.0 nm to 2.0 nm. The diameter of SWCNT is controlled by the size of the catalyst nanoparticles. Some bundles of SWCNT and double-walled nanotubes were also found. The possible mechanism of compound growth is briefly discussed. [ABSTRACT FROM AUTHOR]

Investigates the electrochemical and electrocatalytic behavior of single-wall carbon nanotube (SWNT) film on a glassy carbon electrode. Stable group corresponding to the redox of the carboxylic acid group; Biomolecules that derived favorable electrocatalytic behavior from the SWNT film-modified electrode.

We present a simple approach of tuning the hole doping level of iodine-doped single-walled carbon nanotubes by adjusting temperature, utilizing the structural conversion of iodine species encapsulated in SWNTs. [ABSTRACT FROM AUTHOR]

Triple-walled carbon nanotubes (TWNTs) with three concentric cylindrical graphene layers have been selectively synthesized for the first time from decomposition of ferrocene encapsulated inside double-walled carbon nanotubes, and were identified by high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy; HRTEM observations reveal that the formation of inner tubes of TWNTs follows a base-growth mechanism. [ABSTRACT FROM AUTHOR]

Two-bit memory devices of SWNTs, based on the hysteresis effect, have been demonstrated for the first time. The pertinent memory behaviours seem to originate from the capacitive effect due to polarization of molecules, especially the surface-bound water molecules on SiO2in close proximity to carbon nanotubes. Our investigations are intimately linked with ultrahigh-density memory applications, and possibly go a long way in broadening the memory applications of SWNTs, for example from nonvolatile to volatile cells. [ABSTRACT FROM AUTHOR]

Examines the electrochemistry of a horse heart cytochrome c using cyclic voltammetry with single-wall carbon nanotubes. Reaction of electrodes to cytochrome c; Interaction of cytochrome c with adenine; Mechanical properties of single-wall carbon nanotubes.

Quasi-one-dimensional nanotubes and two-dimensional nanoribbons are two fundamental forms of nanostructures, and integrating them into a novel mixed low-dimensional nanomaterial is fascinating and challenging. We have synthesized a stable mixed low-dimensional nanomaterial consisting of MoS2 inorganic nanoribbons encapsulated in carbon nanotubes (which we call nanoburritos). This route can be extended to the synthesis of nanoburritos composed of other ultranarrow transition-metal chalcogenide nanoribbons and carbon nanotubes. The widths of previously synthesized MoS2 ribbons are greater than 50 nm, while the encapsulated MoS2 nanoribbons have uniform widths down to 1-4 nm and layer numbers down to 1-3, depending on the nanotube diameter. The edges of the MoS2 nanoribbons have been identified as zigzag-shaped using both high-resolution transmission electron microscopy and density functional theory calculations. [ABSTRACT FROM AUTHOR]

The article studies the coalescence of C60 molecules assisted by intratubular doped iodine atoms inside single-walled carbon nanotubes (SWNT). According to the results of the high-resolution transmission electron microscope and Raman spectroscopy, the doped iodine atoms can assist the structure transformation of fullerenes inside SWNTs. The authors note that heating the iodine-doped peopod at 550 °C induces the transformation of fullerenes into a tubular structure.