MiR-431 inhibits colorectal cancer cell invasion via repressing CUL4B.

OBJECTIVE: To detect the expression of microRNA-431 (miR-431) in epithelial-mesenchymal transition (EMT) in colorectal carcinoma and investigate its effects on the migration of colorectal cancer cells. PATIENTS AND METHODS: MiR-431 expressions in colorectal cancer tissues and adjacent tissues were examined via Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The expression levels of cullin-4B (CUL4B) and EMT-related protein were evaluated by Western blotting assay. The invasive ability of the cells was examined via transwell method. RESULTS: The expression level of miR-431 in colorectal cancer tissues was lower than that in adjacent tissues (p<0.05). After colorectal cancer cell line was transfected with miR-431 mimics, the expression level of e-cadherin was increased in the cells, and the expression levels of n-cadherin, vimentin, fibronectin (FN), and snail were reduced (p<0.05). The migration ability of colorectal cancer cells with miR-431 overexpression was significantly decreased. Moreover, the reverse effect was observed in cells transfected with miR-431 inhibitors. CONCLUSIONS: The low expression of miR-431 in colorectal cancer patients is involved in the development of colorectal cancer by promoting the migration of colorectal cancer cells.

Single-step deposition of high-mobility graphene at reduced temperatures.

Current methods of chemical vapour deposition (CVD) of graphene on copper are complicated by multiple processing steps and by high temperatures required in both preparing the copper and inducing subsequent film growth. Here we demonstrate a plasma-enhanced CVD chemistry that enables the entire process to take place in a single step, at reduced temperatures (<420 °C), and in a matter of minutes. Growth on copper foils is found to nucleate from arrays of well-aligned domains, and the ensuing films possess sub-nanometre smoothness, excellent crystalline quality, low strain, few defects and room-temperature electrical mobility up to (6.0±1.0) × 10(4) cm(2) V(-1) s(-1), better than that of large, single-crystalline graphene derived from thermal CVD growth. These results indicate that elevated temperatures and crystalline substrates are not necessary for synthesizing high-quality graphene.

Field-induced expansion deformation in Pb islands on Cu(111): evidence from energy shift of empty quantum-well states.

We use scanning tunneling microscopy and spectroscopy to measure the energy shift of empty quantum-well (QW) states in Pb islands on the Cu(111) surface. It is found that, with an increase of the electric field, the behavior of the energy shift can be grouped into two different modes for most QW states. In the first mode, the state energy moves toward high energy monotonically. In the second mode, the state energy shifts to a lower energy initially and then turns around to a higher energy. Moreover, we have observed that the QW states of higher energy behave in preference to the first mode, but they gradually change to the second mode as the Pb island becomes thicker. This thickness-dependent behavior reflects the existence of local expansion in the Pb islands, due to the electric field, and that the expansion is larger for a thicker island. QW states can thus be used for studying the localized lattice deformation in the nanometer scale.

Investigation of magnetic properties and microstructure of ultrathin Co films grown on Si(111)- 7 x 7 surface.

Magnetic properties and growth mechanism of ultrathin Co films on Si(111)-7 x 7 surface have been studied by using both surface magneto-optic Kerr effect (SMOKE) and scanning tunneling microscopy (STM), respectively. STM results show that the growth mechanism of ultrathin Co films on Si(111)-7 x 7 surface at room temperature belongs to Stranski-Krastanov (SK) growth mode. Due to formation of CoSi2 layer, no magnetic signal could be detected by SMOKE for 1-4 ML Co deposited on Si(111) surface. Because of rougher surface, both longitudinal and perpendicular magnetic anisotropy configuration appear for 4.2-10 ML Co/Si(111) films. When the Co thickness is increased to 10 ML, only longitudinal anisotropy configuration is found, resulting from the contribution to the volume anisotropy. Furthermore, in-plane coercivity increases with Co coverage because of enhancement of ferromagnetic coupling with Co thickness, out-of-plane coercivity increases with Co coverage due to the increment of demagnetized field, induced by the rougher Co surface and pinhole structures.

Co nanoislands on Au(111) and Cu(111) surfaces studied by scanning tunneling microscopy and spectroscopy.

Co nanoislands on the Au(111) and Cu(111) surfaces have been studied by scanning tunneling microscopy and spectroscopy. The experimental results showed that Co nanoislands prefer to aggregate at the step edge and dislocation sites on the reconstructed Au(111) surface and at the step edge on the Cu(111) surface, respectively. In addition, based on dZ/dV-V spectra, in both the Co/Au(111) and the Co/Cu(111) systems, Gundlach oscillation was observed. From the peak shift of dZ/dV-V spectra between Co nanoisland and substrate surface, we can quantitatively obtain that the constant energy separation is -0.13 +/- 0.01 eV for the Co/Au(111) system, and 0.41 +/- 0.02 eV for the Co/Cu(111) system, respectively. These values indicate the work function difference between Co nanoisland and these surfaces.

Phase contribution of image potential on empty quantum well States in pb islands on the cu(111) surface.

We use scanning tunneling spectroscopy to explore the quantum well states in the Pb islands grown on a Cu(111) surface. Our observation demonstrates that the empty quantum well states, whose energy levels lie beyond 1.2 eV above the Fermi level, are significantly affected by the image potential. As the quantum number increases, the energy separation between adjacent states is shrinking rather than widening, contrary to the prediction for a square potential well. By simply introducing a phase factor to reckon the effect of the image potential, the shrinking behavior of the energy separation can be reasonably explained with the phase accumulation model. The model also reveals that there exists a quantum regime above the Pb surface in which the image potential is vanished. Moreover, the quasi-image-potential state in the tunneling gap is quenched because of the existence of the quantum well states.

Manifestation of work function difference in high order Gundlach oscillation.

Gundlach oscillation (or the standing-wave state) is a general phenomenon manifesting in the tunneling spectrum acquired from a metal surface using scanning tunneling spectroscopy. Previous studies relate the energy shift between peaks of the lowest-order Gundlach oscillation observed on the thin film and the metal substrate to the difference in their work functions. By observing Gundlach oscillations on Ag/Au(111), Ag/Cu(111), and Co/Cu(111) systems, we demonstrate that the work function difference is not the energy shift of the lowest order but the ones of higher order where a constant energy shift exhibits. Higher order Gundlach oscillations can thus be applied to determine the work function of thin metal films precisely.

Vertical friedel oscillations in interface-induced surface charge modulations of ultrathin quantum islands.

Two-dimensional Pb islands of a few atomic layers are grown on the incommensurate Si(111)-Pb surface at low temperatures. Among them, two types of islands having different stacking with the substrate are observed. These islands, respectively, display an alternating image contrast with their thickness. Besides, the contrasts of the islands of different types are complementary to each other layer by layer. These intriguing behaviors do not show significant bias dependence throughout the range from -3 to +3 V and can be explained by the vertical charge oscillation with the growth of a new layer. The charge oscillation in the out-of-plane direction originates from electron scattering by the in-plane potential variation at the Pb/Si interface.

Correlation between quantized electronic states and oscillatory thickness relaxations of 2D Pb islands on Si(111)-(7 x 7) surfaces.

Two-dimensional lead (Pb) islands of varying heights have been grown on the Si(111)-(7 x 7) surface at low temperature. Individual islands are investigated concurrently with real-space and local-probe scanning tunneling microscopy and spectroscopy. Quantum size effects, manifested in the formation of new electronic bound states, redistribution of surface charge density, and oscillatory relaxations in island thickness are found to be perfectly correlated to each other.

Fiberglass dermatitis: a case report.

Glass fibers are the most widely distributed mineral fibers because of their multiple applications, chiefly as insulation materials, and have become important in replacing asbestos fibers. Fiberglass dermatitis is one of the most common forms of occupational dermatitis resulting from mechanical irritation. Here we report a typical case. A 30-year-old male worker handled the cutting and grinding of fiberglass mats and then mixed them with resin as reinforcing materials. He complained of intense itching after the first two weeks of employment. Erythematous macules, papules and folliculitis with excoriation developed over his arms, neck, face and upper chest. There were many transparent glass fiber spicules with the diameter around 7-10 microns detected by applying the adhesive tape against the skin lesion, followed by microscopic observation. He was much improved during hospitalization with oral antihistamine and topical steroid ointment. To prevent this occupational disease, we suggest proper procedures of production, storage, transportation and cleaning in the industrial setting and proper protective clothing in personnel to minimize the release of and exposure to glass fibers.