We describe the first wide-band tellurite-based fiber Raman amplifier (T-FRA) for application to seamless ultra-large-capacity dense wavelength-division multiplexing (WDM) systems. First, we ...confirmed that the Raman scattering characteristics of the tellurite-based fiber has so large a gain coefficient and Stokes shift that we can achieve a wide-band tellurite-based fiber Raman amplifier with a shorter fiber length than when using silica-based fiber. Second, we investigated the small signal gain and the signal transmission characteristics for a high gain and high output power operation with a single-stage amplifier. Focusing on double Rayleigh scattering, we compared the high gain limit of tellurite- and silica-based fibers. We then studied the impact of nonlinear effects by measuring the bit error rate (BER) when using a two-stage amplifier with a high output power of 18.8 dBm in which we simultaneously amplified eight channel signals in the L-band located on the ITU 100-GHz grid. Finally, we designed a wide-band tellurite-based fiber Raman amplifier with a multiwavelength band pumping scheme. We constructed this amplifier with a tellurite-based fiber only 250 m in length pumped by four-wavelength-channel laser diodes, and it provided a 160-nm bandwidth with a gain of over 10 dB and a noise figure below 10 dB from 1490 to 1650 nm. We also measured the BER to confirm the transmission characteristics of the amplifier for single channel operation over the whole signal wavelength range of 160 nm. We thus confirmed that the amplifier could be employed in ultra-high-capacity WDM systems.
In this study, the effect of Fe–Zn alloy layer that is formed during galvanizing process on the corrosion behavior of galvanized steel has been investigated. The galvanostatic dissolution of ...galvanized steel was carried out in 0.5
M NaCl solution to obtain the Fe–Zn alloy layer on the base steel. The alloy layer was characterized to be composed of FeZn
13, FeZn
7 and Fe
3Zn
10 intermetallic phases, which constitute the zeta, delta1 and gamma layers of galvanized steel, respectively. It was observed that the alloy layer has similar cathodic polarization behavior but different anodic polarization behavior compared to galvanized steel. The anodic current plateau of alloy layer was up to 100 times lower than that of galvanized coating. Corrosion test performed in wet–dry cyclic condition has shown that the alloy layer has lower corrosion rate as compared to galvanized steel. From the results of corrosion test of alloy layer and base steel, it was concluded that Zn
2+ has positive effect on the protectiveness of the zinc corrosion products. The measurement of surface potential over the alloy/steel galvanic couple has confirmed the galvanic ability of alloy layer to protect both the alloy layer itself and the base iron during initial stage of atmospheric corrosion.
Metal nanohole arrays with straight holes of high aspect ratio have been fabricated using a new replication process based on the preparation of polymer pillars, both sides of which are supported and ...can therefore be maintained upright. These nanopillar arrays are demonstrated as negatives for the preparation of metal (Ni) nanohole arrays (see Figure).
Abstract Aim Dysfunction of circulating endothelial progenitor cells (EPCs) has been shown to affect the development of microvascular diseases in diabetes patients. The aim of this study was to ...elucidate the development and mechanical dysfunction of EPCs in type 2 diabetes (T2D). Methods The colony-forming capacity of EPCs and differentiation potential of bone marrow (BM) c-Kit(+)/Sca-I(+) lineage-negative mononuclear cells (KSL) were examined in T2D mice, db/db mice and KKAy mice, using EPC colony-forming assay (EPC-CFA). Results T2D mice had fewer BM stem/progenitor cells, and proliferation of KSL was lowest in the BM of db/db mice. In T2D mice, the frequency of large colony-forming units (CFUs) derived from BM-KSL was highly reduced, indicating dysfunction of differentiation into mature EPCs. Only a small number of BM-derived progenitors CD34(+) KSL cells, which contribute to the supply of EPCs for postnatal neovascularization, was also found. Furthermore, in terms of their plasticity to transdifferentiate into various cell types, BM-KSL exhibited a greater potential to differentiate into granulocyte macrophages (GMs) than into other cell types. Conclusion T2D affected EPC colony formation and differentiation of stem cells to mature EPCs or haematopoietic cells. These data suggest opposing regulatory mechanisms for differentiation into mature EPCs and GMs in T2D mice.
Dot—or multiple dot—arrays of nanometer dimensions have applications in nanodevices. Control of the size and site of each dot is essential as variations can alter the optical or catalytic properties ...of the composite metal nanoparticles. A method is presented in which anodic porous alumina, a typical self‐organized structure, is used as an evaporation mask for the shadow evaporation of a metal beam, enabling the spatially resolved deposition of the metal—or several different metals—at the bottom of the apertures of the mask. Each dot in the array is composed of two or three deposits of one or more metals.
Lactosylceramide (LacCer), which is essential for many cellular processes, is highly expressed on the plasma membranes of human neutrophils and mediates innate immune functions. Less is known, ...however, about the properties and biological functions of LacCer in mouse neutrophils. This study therefore analyzed the properties of mouse neutrophil LacCer. LacCer was observed on the surface of these cells, with flow cytometry indicating that mouse neutrophil LacCer could be detected by the anti-LacCer mAb T5A7, but not by the anti-LacCer antibodies Huly-m13 and MEM-74. The molecular species of LacCer were nearly identical in mouse and human neutrophils, including C24:0 and C24:1 fatty acid chain-containing species, although the LacCer content in plasma membranes was ∼ 20-fold lower in mouse than in human neutrophils. Surface plasmon resonance analysis revealed that T5A7 bound to a lipid monolayer composed of LacCer, DOPC, cholesterol and sphingomyelin (molar ratio 0.1 : 10 : 10 : 1), whereas Huly-m13 did not. T5A7 induced neutrophil migration, which was abolished by inhibitors of Src-family kinases, PI-3 kinases, and trimeric G (o/i) proteins. T5A7 also inhibited phagocytosis of non-opsonized zymosans by neutrophils. Taken together, these findings suggest that in mouse neutrophils, (i) LacCer is expressed as LacCer-enriched microdomains in cell surface plasma membranes, (ii) these microdomains are recognized by T5A7 but not by other known anti-LacCer antibodies and (iii) LacCer is involved in cell migration and phagocytosis.
Mirrorless laser emission from fluorescent dye‐loaded anodic porous alumina with an ideally arranged hole array configuration is observed. The wavelength of the laser emission (see Figure) appears at ...the edge of the photonic bandgap in the two‐dimensional photonic bandgap that originates from the anodic porous alumina, and can be tuned by changing the geometrical structure of the anodic porous alumina.
This paper summarizes our research on the theory and application of particle charging in gas–solids pipe flow. The particles moving in a pipe are charged by collisions with the pipe wall. The charge ...transferred from the particles to the wall per unit time is equal to the electric current flowing from the wall to earth, and the current depends on the mass flow rate and the charge-to-mass ratio. Conversely, these values can be calculated from the electric current using a special technique; i.e., two short pipes that are made of different materials are installed in series with electrical isolation. The principle of the calculation is based on the contact charging between different materials and the charge balance in the system; the simultaneous equations can be solved analytically. This method is applicable to online measurement for polymer powders as well as mineral powders.
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