Functional analyses of neutrophil-like differentiated cell lines under a hyperglycemic condition

Diabetic patients are prone to severe bacterial infections. The functional alterations of neutrophils by hyperglycemia are thought to be partially responsible for such infections. In this study, we investigated the functional changes of neutrophil-like differentiated cell lines (dHL-60, dTHP-1, and dNB-4) by treatment with 5.5 mM, 11 mM, or 35 mM of glucose. In dHL-60 cells, the incubation with high glucose (35 mM) resulted in the enhancement of cell aggregation, the suppression of cellular fragility, the induction of reactive-oxygen species (ROS) production by phorbol myristate acetate (PMA) stimulation, and the impairment of phagocytosis. In dTHP-1 cells, the treatment with higher glucose generated the suppression of cellular fragility and extremely impaired phagocytosis (by 35 mM), and induced ROS production due to PMA stimulation (by 11 mM). Furthermore, the higher glucose exposure to dNB-4 cells enlarged intracellular vacuoles (by 35 mM) and induced ROS production due to PMA stimulation (by 11 mM). Since the ROS generation of those cells was enhanced only after PMA stimulation under the higher glucose conditions, glucose may have a priming effect rather than a triggering effect. These extraordinary sensitivities caused by the higher glucose treatments may reflect the dysfunction or overactivation of neutrophils.     

Preparation of nanocomposites by melt compounding polylactic acid/polyamide 12/organoclay at different screw rotating speeds using a twin screw extruder

This study analyzes the effect of different screw rotating speeds on the clay dispersion and mechanical properties of nanocomposites prepared by melt compounding polylactic acid (PLA) with an organoclay in a co‐rotating twin screw extruder. Polyamide 12 (PA12) was used as an additive. Two different screw rotating speeds, 65 rpm and 150 rpm, were used in this study. According to the tensile strength data, the Young's modulus of the PLA/clay nanocomposites showed improvement at a screw rotating speed of 150 rpm. The Young's modulus improved with the addition of the organoclay to PLA matrix, but decreased when PA12 was added to the PLA matrix. The tensile strengths and elongations become small by adding organoclay to PLA matrix. The tensile strengths of the PLA/organoclay nanocomposites increased for the higher screw rotating speed (150 rpm). The d‐spacing of PLA/PA12/Clay nanocomposites was independent of the addition of PA12. The size of the clay aggregates in the PLA/PA12/Clay nanocomposites is smaller than that of PLA/Clay. Furthermore, the thermal stability of the PLA/Clay nanocomposite increases with addition of PA12, while on the whole, it had little influence on the tensile properties. POLYM. COMPOS., 29:1–8, 2008. © 2007 Society of Plastics Engineers     

Physicochemical characteristics of rapidly dried onion powder and its anti-atherogenic effect on rats fed high-fat diet

Rapidly dried onion (Allium cepa L. cv. Momiji No. 3) powder (OP) prepared from the outer layers (from second to fourth scale leaves from the surface) of onion bulbs was analysed for its quercetin and polyuronide contents, the effects of enzymatic treatment and the anti-atherogenic effect on rats fed a high-fat diet. Quercetin 4′-glucoside (50%), free quercetin (30%) and quercetin 3,4′-diglucoside (20%) were identified as quercetin derivatives, and boiling-water extraction was effective in extracting these compounds. OP contained 12.9% of polyuronides, the basic skeleton of pectin. Enzymatic degradation (cellulase and pectinase, 50 °C for 12 h, pH 6.0) of OP was effective in obtaining a slurry of smaller particle sizes. The free quercetin increased and the glucosides decreased with enzyme treatment. In Wistar rats fed an OP-added high-fat diet, the total cholesterol, HDL-cholesterol and triglyceride concentrations were not significantly different from the rats fed a high-fat diet without OP. However, the atherogenic index (AI) of Wistar rats fed an OP-added high-fat diet was lower (AI = 3.3) than rats fed the diet without OP (AI = 4.1). The incremental elastic modulus (IEM) of the aorta from rats fed the OP-added diet was also significantly lower than that of the rats fed the diet without OP. The AI and IEM values of the rats fed the OP-added diet were quite similar to the values of rats fed the diet without OP but were allowed spontaneous exercise. These results suggest that OP intake is effective for decreasing the risk of arteriosclerosis.     

An FPGA implementation of hard‐wired sequence control system based on PLC software

Although a programmable logic controller (PLC) has been widely adopted for the sequence control of industrial machinery, its performance does not always satisfy the recent requirements in large and highly responsive systems. With the state‐of‐the‐art field programmable gate array (FPGA) technology, it is possible to implement a control program with hard‐wired logic for higher response and reduced implementation cost/space. This approach is also worthwhile for transmigration of legacy PLC software into forthcoming FPGA‐based control hardware. This study presents a systematic method to implement a hard‐wired sequence control from PLC software. PLC instructions are converted into VHDL codes, and then implemented as logic circuit with various peripheral functions. Productive PLC programs were examined with Mitsubishi Electric FX2N PLC and Altera Stratix II FPGA, and were shown to fit into a common FPGA chip. A straightforward Sequential design was estimated to be 184 times faster than PLC, while a performance‐oriented Flat design was estimated to be 44 times faster than Sequential design (i.e., 8050 times faster than PLC). A practical perfect layer winder system was actually built and successfully operated with our FPGA control board, whose logic design was implemented with our tools. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Development of lateral displacement sensor for real‐time detection of structural damage

We have developed a novel sensor that enables us to measure the relative story displacement of a building structure in real time. This lateral displacement sensor (LDS) is composed of a light‐emitting diode (LED) array, which is fixed on the ceiling, and a position‐sensitive detector (PSD) unit, which is placed on the floor. We optimized the LDS to achieve high accuracy in lateral displacement measurement. The accuracy was evaluated to be 60 µm by conducting shaking table tests. Two LDSs were implemented in an actual building equipped with an active variable stiffness (AVS) system, and the building was vibrated with seismic waveforms by an exciter placed on the rooftop. The seismic displacement of the second floor relative to the first floor was measured using the LDS. Furthermore, the inclination angle of the second floor could be measured using the LDS during the seismic vibration. Using the AVS system, we realized the residual displacement of the second floor without inducing damage to the building, and succeeded in real‐time residual displacement measurement for the first time. These results indicate that the LDS is useful for the health diagnosis of a building structure. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Calculation of the Characteristics of Salient‐Pole Synchronous Machines Assisted by Permanent Magnets on the Basis of the Operating Principle

In this study we investigate a method for accurately calculating the characteristics of salient‐pole synchronous machines assisted by permanent magnets. First, the operating principle of the machines is investigated by using both finite element analysis and a simple magnetic circuit. Then, a theoretical representation of the assist effect on the permanent magnets is derived based on the magnetic circuit. Finally, the measured and calculated results are compared in order to confirm the validity of the proposed calculation method. We show that the load characteristics of the proposed machine can be accurately estimated from the no‐load and short‐circuit characteristics of the conventional machine without permanent magnets, and the size and magnetization of the inserted permanent magnets.     

Eutectic compound (KNO3/NaNO3 : PCM) quasi‐encapsulated into SiC‐honeycomb for suppressing natural convection of melted PCM

The phase change eutectic compound, KNO₃/NaNO₃ (50/50 mol%) (phase change material (PCM)), which is used as the thermal energy storage material in the solar thermal power plant, was quasi‐encapsulated into the SiC‐honeycomb (SCH) for suppressing the natural convection occurring at the liquid state of PCM. The performance of the SCH as the material suppressing natural convection of PCM was investigated experimentally. PCM with three kinds of mixing ratios of SCH of 10%, 20%, and 30%, was prepared and packed in their respective stainless can with oil‐flowing pipe in the center, which is called thermal energy storage unit (TESU). Three units were linked together and stacked vertically by the connector at the inlet/outlet oil pipe. The time variation of temperature at the fixed positions inside the TESU in charging/discharging process and temperature gradient in the radial direction inside TESU when PCM was liquid state were investigated. It is concluded that the natural convection is suppressed by mixing the SCH with PCM up to around 30% in weight, because the PCM is quasi‐encapsulated into cell holes and porous structures of SCHs. And thus, the heat transfer of the PCM + 30%SCH composite is controlled mainly by its thermal conduction, which is also supported through comparison of simulation result with experimental one. And so, we conclude that SCH has a function as the quasi‐encapsulating material for suppressing the natural convection of PCM. Copyright © 2015 John Wiley & Sons, Ltd.     

Antimicrobial Microwebs of DNA–Histone Inspired from Neutrophil Extracellular Traps

Neutrophil extracellular traps (NETs) are decondensed chromatin networks released by neutrophils that can trap and kill pathogens but can also paradoxically promote biofilms. The mechanism of NET functions remains ambiguous, at least in part, due to their complex and variable compositions. To unravel the antimicrobial performance of NETs, a minimalistic NET‐like synthetic structure, termed “microwebs,” is produced by the sonochemical complexation of DNA and histone. The prepared microwebs have structural similarity to NETs at the nanometer to micrometer dimensions but with well‐defined molecular compositions. Microwebs prepared with different DNA to histone ratios show that microwebs trap pathogenic Escherichia coli in a manner similar to NETs when the zeta potential of the microwebs is positive. The DNA nanofiber networks and the bactericidal histone constituting the microwebs inhibit the growth of E. coli. Moreover, microwebs work synergistically with colistin sulfate, a common and a last‐resort antibiotic, by targeting the cell envelope of pathogenic bacteria. The synthesis of microwebs enables mechanistic studies not possible with NETs, and it opens new possibilities for constructing biomimetic bacterial microenvironments to better understand and predict physiological pathogen responses.     

Low‐frequency sound absorption of organic hybrid comprised of chlorinated polyethylene and N,N′‐dicyclohexyl‐2‐benzothiazolyl sulfenamide

We investigated the sound absorption characteristics of an organic hybrid material comprised of chlorinated polyethylene (CPE) as the matrix polymer and N,N′‐dicyclohexyl‐2‐benzothiazolyl sulfenamide (DBS) as the second component of an organic low‐molecular‐weight compound. We found specific crystallites, obtained by annealing, that generated new absorption for a low‐frequency sound in a CPE/DBS blend. We observed two sound absorption peaks, around 300 and 1000 Hz, in the annealed CPE/DBS (50 : 50 w/w) blends, whereas those peaks were not observed in the untreated sample. There were two kinds of crystals with different melting points in the annealed samples. It was confirmed that the crystals with the lower melting point brought about sound absorption at a low frequency. The crystals that had the lower melting point were smaller and/or more disordered than the crystals that had the higher melting point. We calculated the fraction of these two types of crystals from differential scanning calorimetry and wide‐angle X‐ray diffraction measurements. The annealing or reannealing temperature specified the fraction of the crystal with the lower melting point, and the obtained crystal fraction characterized sound absorption frequency. Therefore, it is possible to control the sound absorption frequency of an organic hybrid by heat treatment such as annealing. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Picoliter volume glass tube array fabricated by Si electrochemical etching process

Fabrication process for picoliter volume SiO₂ glass tube array partially embedded in Si wafer was developed. As a template for the glass tubes, macropore array was formed at the surface of n-Si(1 0 0) wafer by photo-assisted electrochemical etching process. The area-selective formation of the array was achieved by applying Au/Cr micropatterns formed at the back-side surface of the substrate as the shade mask, which controls the illumination condition to optimize the etching reaction conditions. Subsequently, surface of the macropores was wet-thermally oxidized to form glass layer, and the bulk Si region was removed by alkaline etching, remaining the “glass tubes”. As a result of complete removal of the bulk Si, released glass tubes were obtained. By partial removal of the bulk Si part, the glass tubes were exposed, fixed in the remaining Si substrate in the form of well-ordered array. It was confirmed that the depth, the exposed region and the wall thickness of each glass tube were controllable by adjusting the parameters such as the duration of the Si electrochemical etching, the alkaline etching and the wet-thermal oxidation, respectively. In order to demonstrate microreaction in the glass tube, aqueous rhodamine B solution was injected into the tubes and excitation light was irradiated to them. As a result, the fluorescence of rhodamine B was clearly detected, confirming the applicability of the glass tubes for various kinds of devices and systems such as microreactors.