层层自组装法制备碳纳米管薄膜研究进展

综述了近年来通过层层自组装法制备碳纳米管薄膜的一些最新研究进展,重点介绍了通过物理吸附和化学吸附两种方式来制备碳纳米管组装膜,并对如何提高碳纳米管薄膜的电化学稳定性方面进行了论述。     

Characterization and CO2 sorption properties of poly[methacryloxypropylheptacyclopentyl‐T8‐silsesquioxane‐ co‐3‐methacryloxypropyltris(trimethylsiloxy)silane]

Poly[methacryloxypropylheptacyclopentyl‐T8‐silsesquioxane (MAPOSS)‐co‐3‐methacryloxypropyltris(trimethylsiloxy)silane (SiMA)] was synthesized through free radical polymerization. The physical and carbon dioxide (CO₂) sorption properties of the copolymer membranes were investigated in terms of the MAPOSS content. As the MAPOSS content increases, the membrane density increased, suggesting a decrease in the fractional free volume. In addition, the thermal stability was improved with increasing the MAPOSS content. These are because of the polyhedraloligomericilsesquioxane (POSS) units that restrict the high mobility of poly(SiMA) segments. The glass transition temperature, T_g of the copolymers was single T_g based on the differential scanning calorimetry, suggesting that the copolymers were random and not phase separation. Based on the CO₂ sorption measurement, the POSS units play a role in reducing Henry's dissolution by suppressing the mobility of the poly(SiMA) component, while POSS units increase the nonequilibrium excess free volume, which contributes to the Langmuir dissolution. Based on these results, the introduction of MAPOSS unit is one of the effective ways to improved the thermal stability and CO₂ sorption property due to the enhancement of the polymer rigidity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Electrical Properties of Pre-Alloyed Cu-P Containing Electrically Conductive Adhesive

In this study, a pre-alloyed Cu-P powder with a trace amount of P (0.002 at.%) was used as a metallic filler in a phenolic resin-based electrically conductive adhesive (ECA). The electrical property of the Cu-P-filled ECA was investigated for long-term stability and reliability by aging at high temperature exposure at 125°C and 85°C/85% RH for 1000 h, respectively. Results showed that the electrical resistivity of the Cu-P-filled ECA could be maintained consistently low after high temperature exposure at 125°C for 1000 h or aging at 85°C/85% RH for 1000 h, compared with the rapidly increased resistivity of Cu-filled ECA over time. A significantly low final resistivity at an order of magnitude of 10^?4 Ω·cm could be maintained in Cu-P-filled ECA even after aging at 85°C/85% RH for 1000 h.     

Contribution of Nitrated Polycyclic Aromatic Hydrocarbons in Diesel Particles to Human Lung Cancer Induction

By following the prognosis of 112 patients with carcinomas, we found that the deposition of 1-nitropyrene (1-NP), 1,3-dinitropyrene (1,3-DNP), and 3-nitrofluoranthene (3-NF) in lung tissues influenced their 5-year-survival after determination of chemicals. Lung specimens were divided into two groups of higher and lower chemical concentrations at levels of 18 pg/g for 1-NP, 15 for 1,3-DNP, and 35 for 3-NF, and the findings were statistically analyzed by adjusting for age, gender, stage, smoking status and cell type. The 5-year-survival of patients was significantly lower in the higher concentration group than the lower group. In addition, the higher concentration group correlated significantly with poor cell differentiation. The results suggest that tumors can be induced by continuous deposition of small amounts of environmental carcinogens in human lungs.

Formation of 8-hydroxyguanosine (8-OHdG) is normally used as a biomarker of oxidative damage in in vitro and in vivo systems. 8-OHdG was detected in all 22 cases of lung tissues with carcinomas, and levels increased with the increasing age of the patients, suggesting a correlation between age and the presence of diesel-originating carbon particles in lung tissues. In the inhatlacheal intratracheal administration diesel particles without most organic chemicals into mice, & OHdG formation was elevated more than by a single admummion of benzo[a]p,mne, 1-NP and 1,8-DNP. These results suggest that olbaneceous particles, but not mutagens or carcinogens, promote the formation of & OHdG, and that as a mechanism, alveolar mamphages may be assoCiated with oxidative damage, involving the generation of a hydroxyl radical during phagocytosis in the lungs.     

Immunological Effects of Oenothein B,an Ellagitannin Dimer,on Dendritic Cells

Oenothein B is a unique macrocyclic ellagitannin dimer that has been found in various medicinal plants belonging to Onagraceae, Lythraceae, and Myrtaceae, with diverse biological activities. The immunological effects of tannins in terms of cytokine-release from macrophages and monocytes have been discussed, while the effects on other immunocompetent cells have been the subject of minimal investigation. We evaluated the immunomodulatory effects induced by tannin treatment in human dendritic cells (DCs), which play a critical role in the initial immune response, by measuring the changes in cytokine production, cell differentiation, and cell viability. Oenothein B showed significant down-regulation of the expression of cell surface molecules, CD1a and CD83, suggesting the inhibition of DC differentiation and/or maturation. The suppressive effect on DCs was associated with the induction of apoptosis without the activation of caspase-3/7, 8, and 9, and this was supported by the morphological features indicating significant nuclear condensation. Oenothein B also markedly suppressed the production of inflammatory cytokines, such as IL-1β and IL-6, in a dose-dependent manner. These data may, in part, be able to explain the traditional use of tannin-containing medicinal plants for the treatment of a variety of inflammatory diseases, including inflammatory bowel disease, celiac disease, and rheumatoid arthritis.     

Serial Changes of Serum Growth Factor Levels and Liver Regeneration after Partial Hepatectomy in Healthy Humans

This study aimed to investigate the associations of the serial changes of serum levels of various growth factors with liver regeneration after hepatectomy in healthy liver donors. Sixteen healthy liver donors who underwent conventional liver resection were included. Serum levels of various growth factors before hepatectomy and on postoperative day (POD) 1, 3, 5 and 7 were measured. Liver volume data calculated by multi-detector computed tomography using workstation. The ratio of remnant liver volume on POD 0 to liver volume before the operation was 51% ± 20%. The ratio of liver volume on POD 14 to liver volume on POD 0 were inversely correlated with remnant liver volume on POD 0 (r = −0.91). The ratio of liver volume on POD 14 to liver volume on POD 0 were significantly correlated with serum hepatocyte growth factor (HGF) levels on POD 1 (r = 0.54), serum leptin levels on POD 1 (r = 0.54), and serum macrophage colony-stimulating factor (M-CSF) levels on POD 5 (r = 0.76) and POD 7 (r = 0.80). These results suggest that early-phase elevation of serum levels of HGF, leptin and M-CSF may be associated with the acceleration of liver regeneration after hepatectomy in humans.     

A windows software for simulation of the membrane excitation in nerve and skeletal muscle fiber.

A windows 95/98 software program for simulating membrane excitation in nerve and skeletal muscle fiber has been developed. This program simulates (1) the action potentials of the nerve under two conditions (space clamped conditions and conducting conditions), (2) the membrane currents of the nerve under voltage clamped conditions, and (3) the propagated action potentials of skeletal muscle fiber. Since users can utilize quadruple precision in the simulation of propagated action potentials, such simulation can be done for a long period (60 ms in skeletal muscle at 2 degrees C). In addition, users can change the conditions such as the capacitance of the membrane, the maximum conductance of the channel, etc., arbitrarily without quitting the program. It is also possible to easily modify the time and the voltage dependence of the gate particles in order to confirm the effects of various changes on the action potential or the membrane current. This program also has an analysis mode in which the current-voltage relationship of a channel can be measured automatically.     

Plasma-tolerant structure for organic light-emitting diodes with aluminum cathodes fabricated by DC magnetron sputtering: Using a Li-doped electron transport layer

We fabricate aluminum cathodes that are almost free from plasma damage by DC magnetron sputtering for organic light-emitting diodes (OLEDs). While sputtering is widely known to have numerous advantages over conventional evaporation for mass production of devices, it can cause serious damage to organic layers. In this report, we fabricate devices that are free from plasma damage by introducing a 1%-Li-doped electron transport layer (ETL). The difference of external electroluminescence quantum efficiency between OLEDs with the structure ITO/α-NPD/ETL/Al (where ITO is indium tin oxide and α-NPD is N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine) with Al cathodes deposited by conventional evaporation or sputtering is 0.1%, and their driving voltage is identical. We find that the Li-doped ETL should be thicker than 40 nm. Analysis of the depth profile of the ETL by time-of-flight secondary ion mass spectrometry indicates that considerable damage from sputtering extended to a depth of approximately 30 nm, suggesting that high-energy particles penetrated about 30 nm into the ETL.     

PCE-based fast path control in multi-domain photonic networks

We discuss issues for controlling an optical path in large-scale photonic networks, and introduce an inter-domain path control system based on Path Computation Elements (PCEs). In the system, maximum flow information enables the load balancing of traffic, and Path Key scheme preserve the confidentiality of internal topology information among carrier networks. Based on the experimental results, we show the path setup in the introduced system is significantly faster than the manual path setup among domains in current carriers' networks. For the additional reduction of the path setup time, we propose the domain-wise paralleled signaling method. We also show that decreasing the number of nodes per domain makes path setup faster in the introduced system with deployment of the proposed signaling method.     

A quad‐band W‐CDMA transceiver IC–direct conversion architecture with fractional frequency divider

A quad‐band (0.8, 1.7, 2, and 1.4 GHz) wideband code division multiple access (W‐CDMA) transceiver, which uses a divide‐by‐2.5 frequency divider in local parts of a direct‐conversion architecture, has been developed. Using the fractional‐2.5 frequency divider reduces the fractional bandwidth of the voltage‐controlled oscillator and avoids injection locking of the local RF synthesizer perfectly. This transceiver achieved 3% error‐vector magnitude and—46 dB ACLR, which satisfy the margin given in standard specifications. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.