Through-Hole Contact (THC) integrated-type a-Si solar cell submodule by a new laser photo-etching method

A new laser photo-etching method has been developed for the formation of microscopic holes on a Through-Hole Contact (THC) integrated-type a-Si solar cell which is expected to obtain high output performance. It was confirmed that the insulator film can be removed without causing damage to the TCO (Transparent Conductive Oxide) film during formation of microscopic holes using a laser photo-etching method. A 6/s% increase in the maximum output power of THC solar cells was obtained by optimizing the hole pattern compared with that of conventional solar cells. Based on this technique, a conversion efficiency of 10.55% for 10 cm x 10 cm THC integrated-type a-Si solar cell submodules was achieved.     

High-efficiency single-cell entrapment and fluorescence in situ hybridization analysis using a poly(dimethylsiloxane) microfluidic device integrated with a black poly(ethylene terephthalate) micromesh

Here, we report a high-efficiency single-cell entrapment system with a poly(dimethylsiloxane) (PDMS) microfluidic device integrated with a micromesh, and its application to single-cell fluorescence in situ hybridization (FISH) analysis. A micromesh comprising of 10 x 10 microcavities was fabricated on a black poly(ethylene terephthalate) (PET) substrate by laser ablation. The cavity was approximately 2 microm in diameter. Mammalian cells were driven and trapped onto the microcavities by applying negative pressure. Trapped cells were uniformly arrayed on the micromesh, enabling high-throughput microscopic analysis. Furthermore, we developed a method of PDMS surface modification by using air plasma and the copolymer Pluronic F-127 to prevent nonspecific adsorption on the PDMS microchannel. This method decreased the nonspecific adsorption of cells onto the microchannel to less than 1%. When cells were introduced into the microfluidic device integrated with the black PET micromesh, approximately 70-80% of the introduced cells were successfully trapped. Moreover, for mRNA expression analysis, on-chip fluorescence in situ hybridization (e.g., membrane permeabilization, hybridization, washing) can be performed in a microfluidic assay on an integrated device. This microfluidic device has been employed for the detection of beta-actin mRNA expression in individual Raji cells. Differences in the levels of beta-actin mRNA expression were observed in serum-supplied or serum-starved cell populations.     

高速连铸结晶器内的保护渣膜

连铸结晶器中形成的保护渣膜在润滑与传热方面起重要作用,但渣膜的厚度和结构还没有完全被人们所了解。本次研究中,保护渣膜试样是取自浇铸结束后连铸结晶器内,保留浇铸期间所处位置的渣膜。通过此次试验,清楚了结晶器内弯月面处保护渣膜的厚度。根据显微镜下对渣膜截面的观察,研究了渣膜的结构,即渣膜的结晶情况。此外,基于上述观察结果,研究了结晶器内通过渣膜的传热现象,得出以下结论： （1）确认结晶器内保护渣膜的厚度约为1mm。玻璃层为连铸中钢水顶部的熔融保护渣,浇铸结束后成为薄膜,将其假定为浇铸期间的保护渣膜。 （2）按结晶器保护渣消耗量可估算出浇铸期间渣膜中的液渣层厚度。 （3）弯月面处渣膜约1mm厚时,辐射及传导的总热阻与渣膜和结晶器之间的界面热阻相等。 （4）文中提到的界面热阻可能大于实际浇铸中结晶器的热阻。原因可能是由于这些热阻是在无钢水压力情况下测得的,实际结晶器内的界面热阻似乎较小。     

Laser-based internal profile measurement system

An automatic laser-based system to measure the internal profiles of various structures has been developed. The system uses a point laser source through a rotating optical device fixed on to a laser measurement meter. A notebook computer with custom software is used to control the laser meter and rotating device to estimate the scanned profile shape and to determine the resulting cross-section area. The information provided by this system is essential to construction industry, including window and door builders; the glass, panel, board, and floor tile manufacturers; carpet venders; and building contractors for cost estimation and production control. As a result, the lead time for delivering the customized windowpanes, woodwork, floor tiles, and ceilings can be reduced. Applications of this system for measuring the shapes of window frames and floor plans are described and demonstrated. The measurement accuracy is evaluated and analyzed. Results have indicated that the measurement accuracy can be achieved within 4% of the measurement distance, for typical window designs and floor patterns required by major widow manufacturers. Recommendations to improve the system are also included.     

One-process surface texturing of a large area by electrochemical machining with short voltage pulses

Micro texturing is performed over a large area of a metal surface by an appropriate electrochemical machining. A micro texture pattern with a size of several tens of micrometers is fabricated on a millimeter-scale tool electrode surface and is simultaneously replicated on the workpiece in one process. A shorter pulse width is required for better machining accuracy, and then branched electric feeding is adopted because the minimum machinable pulse width is limited due to the inductance of the power supply circuit. Micro textures smaller than a hundred micrometers could be achieved with a machining area of several tens of square millimeters.     

Positive association between plasma levels of oxidized low‐density lipoprotein and myeloperoxidase after hemodialysis in patients with diabetic end‐stage renal disease

End‐stage renal disease (ESRD) patients undergoing hemodialysis (HD) have a high prevalence of cardiovascular events. Low‐density lipoprotein (LDL) in dialysis patients has been shown to be susceptible to in vitro peroxidation; therefore, oxidized‐LDL (ox‐LDL) could be generated in these patients. Moreover, myeloperoxidase (MPO) released from activated neutrophils may play a role in the induction of LDL oxidation. The purpose of this study was to investigate the relationship between plasma ox‐LDL levels, plasma MPO levels, and serum high‐sensitivity C‐reactive protein (hs‐CRP) levels during initial HD in patients with diabetic ESRD. Patients (n = 28) had serial venous blood samples drawn before and after HD at the initial, second, and third sessions. Plasma ox‐LDL levels were measured using a specific monoclonal antibody (DLH3), and plasma MPO levels were measured using an enzyme‐linked immunosorbent assay kit. Plasma ox‐LDL levels and MPO levels after a single HD session increased significantly (ox‐LDL, P < 0.005; MPO, P < 0.0001) compared with levels before that HD session. However, the increase was transient since the levels returned to pre‐HD session levels. Additionally, plasma MPO levels showed a positive correlation with plasma ox‐LDL levels during HD (R = 0.62, P = 0.0029). No significant change was observed in serum hs‐CRP levels before and after each HD session. This study demonstrates that plasma MPO levels are directly associated with plasma ox‐LDL levels in diabetic ESRD patients during initial HD. These findings suggest a pivotal role for MPO and ox‐LDL in the progression and acceleration of atherosclerosis in patients undergoing HD.     

Electron-irradiation-induced nano-crystallization in quasicrystal-forming Zr-based metallic glass

Phase selection in electron-irradiation-induced crystallization and crystal-to-amorphous-to-crystal (C–A–C) transition at 298 K in quasicrystal-forming Zr–Pt metallic glass alloys were investigated. Two types of f.c.c. nano-crystalline precipitates were formed in amorphous Zr₈₀Pt₂₀ and Zr_66.7Pt_33.3 alloys under electron irradiation; such unique nano-crystalline structures were not observed during thermal annealing. It was inferred that unique phase selection in electron-irradiation-induced crystallization and thermal crystallization can be explained by the large negative chemical mixing enthalpy (ΔH_chem) in Zr–Pd and Zr–Pt alloys.     

Computation of locational and hourly maximum output of a distributed generator connected to a distribution feeder

Recently, the total number of distributed generation such as photovoltaic generation systems and wind turbine generation systems connected to a distribution network has drastically increased. Distributed generation using renewable energy can reduce the distribution loss and emission of CO₂. However, the distribution network with the distributed generators must be operated while maintaining the reliability of the power supply and power quality. In this paper, the authors propose a computational method to determine the maximum output of a distributed generator under operational constraints [(1) voltage limit, (2) line current capacity, and (3) no reverse flow to bank] at arbitrary connection points and hourly periods. In the proposed method, a three‐phase iterative load flow calculation is applied to evaluate the above operational constraints. The three‐phase iterative load flow calculation has two simple procedures: (Procedure 1) addition of load currents from the terminal node of the feeder to root one, and (Procedure 2) subtraction of voltage drop from the root node of the feeder to terminal one. In order to check the validity of the proposed method, numerical simulations are performed for a distribution system model. Furthermore, the characteristics of locational and hourly maximum output of a distributed generator connected to a distribution feeder are analyzed using several numerical examples. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(2): 38–47, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20610     

Purified Canola Lutein Selectively Inhibits Specific Isoforms of Mammalian DNA Polymerases and Reduces Inflammatory Response

In the screening of DNA polymerase (pol) inhibitor, we isolated lutein, a carotenoid, from the crude (unrefined) pressed oil of canola (low erucic acid rapeseed, Brassica napus L.). Commercially prepared carotenoids such as lutein (1), zeaxanthin (2), β-cryptoxanthin (3), astaxanthin (4), canthaxanthin (5), β-carotene (6), lycopene (7), capsanthin (8), fucoxanthin (9) and fucoxanthinol (10), were investigated for the inhibitory activities of pols. Compounds 1, 2 and 8 exhibited strong inhibition of the activities of mammalian pols β and λ, which are DNA repair- and/or recombination-related pols. On the other hand, all carotenoids tested had no influence on the activity of a mammalian pol α, which is a DNA replicative pol. Lutein (1) was the strongest pol inhibitor of mammalian pols β and λ in the prepared ten carotenoids tested, but did not influence of the activities of mammalian pols α, γ, δ and ε. The tendency for pols β and λ inhibition by these carotenoids showed a positive correlation with the suppression of TPA (12-O-tetradecanoylphorbol-13-acetate)-induced inflammation. These results suggest that cold pressed unrefined canola/rapeseed oil, or other oils with high levels of lutein and other carotenoids, may be useful for their anti-inflammatory properties.     

Nutraceutical approach for preventing obesity-related colorectal and liver carcinogenesis

Obesity and its related metabolic abnormalities, including insulin resistance, alterations in the insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis, and the state of chronic inflammation, increase the risk of colorectal cancer (CRC) and hepatocellular carcinoma (HCC). However, these findings also indicate that the metabolic disorders caused by obesity might be effective targets to prevent the development of CRC and HCC in obese individuals. Green tea catechins (GTCs) possess anticancer and chemopreventive properties against cancer in various organs, including the colorectum and liver. GTCs have also been known to exert anti-obesity, antidiabetic, and anti-inflammatory effects, indicating that GTCs might be useful for the prevention of obesity-associated colorectal and liver carcinogenesis. Further, branched-chain amino acids (BCAA), which improve protein malnutrition and prevent progressive hepatic failure in patients with chronic liver diseases, might be also effective for the suppression of obesity-related carcinogenesis because oral supplementation with BCAA reduces the risk of HCC in obese cirrhotic patients. BCAA shows these beneficial effects because they can improve insulin resistance. Here, we review the detailed relationship between metabolic abnormalities and the development of CRC and HCC. We also review evidence, especially that based on our basic and clinical research using GTCs and BCAA, which indicates that targeting metabolic abnormalities by either pharmaceutical or nutritional intervention may be an effective strategy to prevent the development of CRC and HCC in obese individuals.