Manipulation of micro solid particles and induced flows in water by laser irradiation

Q-switch for pulsing laser beam and Galvano scanner for rapid scanning laser beam were adapted to manipulatemicro solid particles in a water droplet.The trapping of fine particles at micron-sized diameters by a YAG lasersystem,induced flows,and the induced motion of the particles by laser beam irradiations are discussed.Particlerotations are observed by using anisotropic micro objects,and moreover the rotational rate with clockwise direc-tion is 22 r/min.The fragments of a cover glass were mixed in a water droplet,and their size and shape are un-even.The rotation of that non-spheres without scanning by the Galvano scanner is also observed in water.     

A Low-Loss Built-In Current Sensor

This paper presents a novel built-in current sensor that uses two additional power supply voltages besides the system power supply voltage, and that is constructed by using a current mirror circuit to pick up an abnormal IDDQ. It is activated only by an abnormal quiescent power supply current and minimizes the voltage drop at the terminal of the circuit under test. Simulation results showed that it could detect 16-A IDDQ against 0.03-V voltage drop at 3.3-V VDD and that it reduced performance degradation in the circuit under test. It is therefore suitable for testing low-voltage integrated circuits. Moreover, we verified the behavior of the sensor circuit implemented on the board by using discrete devices. Experimental results showed that the real circuit of the sensor functioned properly.     

Damage evolution behavior of CFRP laminates under post-impact fatigue with water absorption environment

In this study, the damage evolution behavior was evaluated considering the effect of the textile structure and water absorption. Damage observation was conducted by the integration of non-destructive and direct observation methods. Candidate textile reinforcements were T300-3k plain woven fabric (PW) and T700S-12k multi-axial knitted fabric (MA). The effect of water absorption on the performances of compression after impact (CAI) and PIF were small in PW CFRP laminates. Conversely, PIF properties of water-absorbed MA CFRP laminates drastically decreased than that of dry ones. CAI strength was not affected by water absorption. PIF performance of dry MA CFRP was fairly higher than that of the others. From the precise observation, some evidences of interfacial deterioration caused by water absorption were confirmed in both PW and MA CFRP laminates.     

A versatile planar QCM-based sensor design for nonlabeling biomolecule detection

Despite high theoretical sensitivity, low-cost manufacture, and compactness potentially amenable to lab-on-a-chip use, practical hurdles have stymied the application of the quartz crystal microbalance (QCM) for aqueous applications such as detection of biomolecular interactions. The chief difficulty lies in achieving a sufficiently stable resonance signal in the presence of even minute fluctuations in hydrostatic pressure. In this work, we present a novel versatile planar sensor chip design (QCM chip) for a microliter-scale on-line biosensor. By sealing the quartz resonator along its edges to a flat, solid support, we provide uniform support for the crystal face not exposed to solvent, greatly decreasing deformation of the crystal resonator under hydrostatic pressure. Furthermore, this cassette design obviates the need for direct handling when exchanging the delicate quartz crystal in the flow cell. A prototype 27-MHz sensor signal exhibited very low noise over a range of flow rates up to 100 microL/min. In contrast, signals obtained from a conventional QCM sensor employing an O-ring-based holder were less stable and deteriorated even further with increasing flow rate. Additional control designs with intermediate amounts of unsupported undersurface yielded intermediate levels of stability, consistent with the interpretation that deformation of the crystal resonator under fluctuating hydraulic pressure is the chief source of noise. As a practical demonstration of the design's high effective sensitivity, we readily detected interaction between myoglobin and surface-bound antibody.     

Fabrication of heterostructures of halogen-bridged quasi-one-dimensional mixed-valence transition metal complexes

Single-heterostructure crystals of a series of halogen-bridged quasi-one- dimensional mixed-valence transition metal complexes (HMMCs) were fabricated by selective coordination epitaxial growth (SCE growth). The overgrowth crystals of the HMMC were grown on the columnar crystals of the substrate HMMC in solution. The single-heterostructure crystals were epitaxially grown only when the two HMMCs had similar crystal structures. If their crystal structures were different, no heterostructure crystal was grown. This result suggests that the degree of mismatch between the crystal structures of the substrate and the overgrowth is the predominant factor which determines the SCE growth of the HMMCs.     

缓变弯道河道冲刷试验研究

有关弯道水流及其河道演变特性的研究一直为人们所关注。本文引入了在直线段和单一曲率圆弯道间插入曲率渐变的过渡段这一新的弯道型式,舒缓水流冲击力和离心力作用,以减轻水流对河床及堤身、堤脚的冲蚀破坏。作者首先对这一弯道和圆弯道的水流流速、副流强度进行了数值模拟的计算和比较;又通过变换床沙、流量及放水时间,进行了24组合的动床试验;最后,通过整理分析所有实验数据,对插有缓变曲线的弯道的减蚀作用进行了探讨。结果表明：插有缓变曲线的弯道可以减轻水流对两岸堤身和堤脚的冲蚀破坏;在弯道同一横断上的最大冲深与沙洲波高的比值最终稳定在0．58。     

Antisense Oligonucleotide Modified with Disulfide Units Induces Efficient Exon Skipping in mdx Myotubes through Enhanced Membrane Permeability and Nucleus Internalization

We have found that antisense oligonucleotides and siRNA molecules modified with repeat structures of disulfide units can be directly introduced into the cytoplasm and exhibit a suppressive effect on gene expression. In this study, we analyzed the mechanism of cellular uptake of these membrane-permeable oligonucleotides (MPONs). Time-course analysis by confocal microscopy showed that the uptake of MPONs from the plasma membrane to the cytoplasm reached 50 % of the total uptake in about 5 min. In addition, analysis of the plasma membrane proteins to which MPONs bind, identified several proteins, including voltage-dependent anion channel. Next, we analyzed the behavior of MPONs in the cell and found them to be abundant in the nucleus as early as 24 h after addition with the amount increasing further after 48 and 72 h. The amount of MPONs was 2.5-fold higher than that of unmodified oligonucleotides in the nucleus after 72 h. We also designed antisense oligonucleotides and evaluated the effect of MPONs on mRNA exon skipping using DMD model cells; MPONs caused exon skipping with 69 % efficiency after 72 h, which was three times higher than the rate of the control. In summary, the high capacity for intracytoplasmic and nuclear translocation of MPONs is expected to be useful for therapeutic strategies targeting exon skipping.     

Completely Chemically Synthesized Long DNA Can be Transcribed in Human Cells

Chemical ligation reaction of DNA is useful for the construction of long functional DNA using oligonucleotide fragments that are prepared by solid phase chemical synthesis. However, the unnatural linkage structure formed by the ligation reaction generally impairs the biological function of the resulting ligated DNA. We achieved the complete chemical synthesis of 78 and 258 bp synthetic DNAs via multiple chemical ligation reactions with phosphorothioate and haloacyl-modified DNA fragments. The latter synthetic DNA, coding shRNA for luciferase genes with a designed truncated SV promoter sequence, successfully induced the expected gene silencing effect in HeLa cells.     

A high-reliability alumina-platinum multilayer system for implantable medical devices

A new Pt-Al₂O₃ multilayer composite system has been developed and validated with an Accelerated Life Test (ALT) to confirm its potential for long-term use in implantable medical devices (IMD). Panels containing over 100 Pt vias were subjected to highly accelerated immersion testing in deionized water at temperatures ranging from 90 to 175°C. Deionized water was employed as it best represents the IMD use environment. Degradation of individual Pt vias was evaluated using fluorescent dye infiltration into the subsurface of the panels. ALT guided refinement of materials and processing to produce a Pt-Al₂O₃ multilayer composite system with promising performance for possible use in implantable devices.     

Formation mechanism of Cu2O particles using layered CaSi2 as a reduction/oxidation mediator

We demonstrate that Cu₂O particles can be produced along with siloxene formation by simply dispersing layered CaSi₂ into an aqueous solution of CuCl₂ and HCl at room temperature. The Cl⁻ ions induce oxidative extraction of Ca from CaSi₂ to form siloxene and trigger the reductive deposition of Cu particles. All particles are then gradually oxidized to form Cu₂O particles under optimized conditions as follows. A trace amount of residual CaSi₂ is dissolved in the solution, which provides OH⁻ ions, and a portion of the formed Cu particles are dissolved as [Cu(OH)₄]²⁻ ions. Accordingly, Cu₂O particles would be formed through the comproportionation reaction between Cu and [Cu(OH)₄]²⁻ ions in the solution. However, under conditions with an excess amount of Cl⁻ ions results in further oxidation of Cu to also form Cu₂Cl(OH)₃. Thus, CaSi₂ acts as an effective reduction and/or oxidation mediator to tune the number of Cl⁻ and OH⁻ ions and control the oxidation state of Cu.