具有力传感器的纳米加工探针的设计

给出了一种用于复杂表面形状精密纳米加工的探针装置．该探针由一个高速可控的金刚石切割单元（FTC单元）和一个高灵敏度的压电式力传感器组成．而FTC单元由一个单点金刚石切割工具和一个压电陶瓷晶体（PZT）驱动器构成．压电陶瓷晶体（PZT）驱动器可对与切削量相对应的金刚石工具的Z向位置进行高速控制,从而实现加工复杂表面形状的目的．加工中的切削力是反映切削进程的重要指标,可由联结于FTC单元的高灵敏度力传感器进行测量．比对了用于联结力传感器和FTC单元的两种设计方法．     

Practical use of the statistically modified laminate model for injection moldings. Part 1: Method and verification

The fibers in injection molded FRP provide the material's strength and stiffness; however, they also supply many of the problems. Preferential orientation of fibers during molding can reduce strength and stiffness below expected values in critical directions, or induce warpage in thin walled sections. Makers of short fiber reinforced injection molded products typically use computer aided engineering packages to optimize product performance and manufacturing variables. However, the reliability of the fiber orientation simulation can be limited, and the method is not easily understood, making an assessment of accuracy for a given situation difficult. In addition, the structural module of flow analysis packages is often a basic package with many features missing. This paper presents a structural analysis system for injection molded parts made of short fiber reinforced plastics. A full-featured commercial structural analysis code is interfaced with a flow analysis program using a practical material model that takes into account the effects of local fiber orientation. The system is completely open to the user, and can be modified as required.     

Context aware messaging service: A dynamical messaging delivery using location information and schedule information

This paper describes a context-based dynamic messaging system. It uses schedule information and location information of the message addressee. According to the addressee's communication context (schedule, location, and available media), the system selects the most suitable telephone number or e-mail address, and redirects each incoming message dynamically. It also writes the schedule and location information of users into an HTML file which users can share on the WWW. It will work as mobile groupware for mobile workers. Evaluating the system during a two-month experiment in Tokyo, we found that our system produced smooth communication and a greater feeling of teamwork.     

Photooxidation of Benzo[ de ]naphtho[2,1,8,7- stuv ]anthra[2,1,9,8- hijkl ]pentacene

This article describes the photooxidation of benzo[ de ]naphtho-[2,1,8,7- stuv ]anthra[2,1,9,8- hijkl ]pentacene (BNAP) synthesized by the condensation of naphthanthrone with zinc dust. When an o -dichlorobenzene solution of BNAP was irradiated with light of its maximum absorption wavelength (535 nm), the original absorption band was reduced and a new band appeared at longer wavelengths showing a peak at 606 nm. Excitation of the photobleached sample with 600 nm gave rise to fluorescence on the red side of that of BNAP by about 90 nm. The new fluorescence spectrum showed a vibrational progression of about 1,600 cm m 1 , which corresponds to the stretching of a carbonyl group. No spectral changes occurred in degassed solution. These findings suggest that BNAP reacts with singlet oxygen to form a ketone. Molecular orbital calculations revealed that the carbonyl group of the product is located at the C-18 position and that a hydroxy group is also present at the C-2 position; therefore the product is predicted as 2,18-dihydrobenzo[ de ]-naphtho[2,1,8,7- stuv ]anthra[2,1,9,8- hijkl ]pentacen-18-one.     

ANALYSIS OF THE METABOLIC TRANSFORMATION OF MUTAGENIC NITROBENZOBENZANTHRONES BY MOLECULAR ORBITAL CALCULATIONS

The mutagenic activity of three nitrobenzobenzanthrones (NBBAs) and two dinitrobenzobenzanthrones (DNBBAs) was found to depend largely on the position and the number of the nitro groups as well as that of nitrobenzanthrones (NBAs). Two NBBAs exhibit the activity approximately two and a half times as large as that of 3-NBA, whereas the other less than one-hundredth. The activity of the DNBBAs is smaller than that of structurally corresponding NBBAs. To elucidate these differences in the mutagenicity, we postulated a metabolic activation pathway of NBAs and NBBAs and calculated physicochemical properties of the parent molecules, metabolites, and ultimate mutagens by the semi-empirical molecular orbital method. Correlation of the results with the mutagenic activity revealed that important factors determining the activity are the LUMO energies of the parent molecules and nitroso-metabolites and the HOMO energies of the hydroxylamino metabolites, which almost the same as those obtained in the case of NBAs and DNBAs.     

Nitration of Condensed Polycyclic Aromatic Ketones

Nitration of three isomeric dibenzanthrones, 13H-dibenzo[a,de]-anthracene-13-one(3), 7H-benzo[hi]chrysene-7-one(4), and 7H-dibenzo[a,kl]anthracene-7-one(5), with concentrated nitric acid was studied under various conditions. The nitration of (3) at 15 °C in 1,1,2,2-tetrachloroethane gave the 5-nitro derivative. The nitration of (4) in boiling acetic acid produced the 9-nitro derivative. The nitration of (5) at 70 °C in acetic acid gave the 5-nitro derivative. These nitro compounds are very useful in synthesizing undecacyclic aromatic hydrocarbons.     

Serotonin/5-HT1A Signaling in the Neurovascular Unit Regulates Endothelial CLDN5 Expression

We previously reported that site-selective claudin-5 (CLDN5) breakdown and protein kinase A (PKA) activation are observed in brain microvessels of schizophrenia, but the underlying molecular basis remains unknown. The 5-HT1 receptors decline the intracellular cAMP levels and inactivate the major downstream PKA, and the 5-HT1A receptor is a promising target for schizophrenia. Therefore, we elucidated the involvement of serotonin/5-HT1A signaling in the endothelial CLDN5 expression. We demonstrate, by immunohistochemistry using post-mortem human brain tissue, that the 5-HT1A receptor is expressed in brain microvascular endothelial cells (BMVECs) and mural cells of the normal prefrontal cortex (PFC) gray matter. We also show that PKA is aberrantly activated not only in BMVECs but also in mural cells of the schizophrenic PFC. We subsequently revealed that the endothelial cell–pericyte tube-like structure was formed in a novel two-dimensional co-culture of human primary BMVECs and a human brain-derived pericyte cell line, in both of which the 5-HT1A receptor was expressed. Furthermore, we disclose that the serotonin/5-HT1A signaling enhances endothelial CLDN5 expression in BMVECs under two-dimensional co-culture conditions. Our findings provide novel insights into the physiological and pathological significance of serotonin/5-HT1A signaling in the region-specific regulation of the blood-brain barrier.     

Concentrated colloids of silica-encapsulated gold nanoparticles: colloidal stability, cytotoxicity, and X-ray absorption

As an effort to develop a new, effective, nontoxic X-ray contrast agent, the concentrated colloids of silica-encapsulated gold nanoparticles (Au@SiO2 NPs) were fabricated and their colloidal stability, cytotoxicity, and X-ray absorption were investigated. The concentrated colloidal NPs were manufactured by forming a 4 nm-thick silica shell on the surface of each Au NP with 15 nm diameter, followed by enrichment to [Au] = 100 mM. They were very stable in water: the NPs were well separated each other without forming agglomerates and their optical property was very similar to that before enrichment. The colloidal stability of the NPs in biological environment was strongly dependent on their previous morphology in water. The NPs with minor shell damage were stable in phosphate buffered saline (PBS) solution: both in water and in PBS solution, they showed very similar morphology and optical property. However, the NPs with profound shell damage formed big agglomerates in PBS solution, resulting in the red-shift and broadening of the Au surface plasmon resonance peak. Cell viability and proliferation assessments revealed the biocompatibility of the Au@SiO2 NPs: no apparent cytotoxicity was observed even at 100 ppm NPs. The concentrated colloidal NPs showed very strong X-ray absorption. Their relative X-ray transmittance to water was comparable to that of a commercial agent. Considering these, the concentrated colloids of the Au@SiO2 NPs are suitable for an X-ray contrast agent.     

Blood compatibility and tissue responsiveness on simple and durable methylsiloxane coating

This study was conducted to evaluate the blood compatibility and tissue responsiveness of methylsiloxane (MS)-coated inorganic (glass and metal) substrates both in vitro and in vivo. MS was prepared from methyltriethoxysilane (MTES) through hydrolysis of a sol–gel solution at 80 °C. The adhesive strength of the MS coating was evaluated by using a tear-off test, revealing that the MS strongly adhered to the surface of the inorganic substrates. Blood compatibility was evaluated by assessing platelet adhesion and blood plasma coagulation time. The platelet aggregation ratio of the MS-coated glass tube was reduced to 10%, which was much smaller than that of the coating-free glass tubes (99%) and conventional blood-compatible polystyrene (PS) tubes (18%). Coagulation time was measured by active partial thromboplastin time (APTT) test, which showed that MS coating is as inert as PS in activating blood coagulation factor XII. Tissue responsiveness to the bulk MS sample, evaluated by animal test, showed a desirable compatibility comparable to that of the control titanium sample. This study indicated that MS coating is readily available to convert inorganic materials to useful biomaterials that have suitable mechanical strength and are compatible with blood and tissue.     

A study of producing an LCL probe for residential power lines

Although power‐line communications are expected as a promising method to realize an in‐home network, one of their difficulties is an unnecessary radiation due to the electrical unbalance of power‐line channels. To solve the problem, the statistical data of electrical unbalance based on measurements in the practical fields, that is, many and various Japanese residential power lines, must be collected as the first step. In this paper, a method to produce a longitudinal‐conversion‐loss (LCL) probe that can be used for the practical measurement is studied. The LCL is a measure of the electrical unbalance, and is often used to determine the impairment of EMC performance of a system by the cabling. To improve the dynamic range of the probe, an adjustment method of the transformers' parameters is proposed. According to our scenario, the obtained dynamic range was better than that of the conventional probe with the frequency band higher than 2 MHz. The achieved improvement was 6 dB at 6 MHz, and 14 dB at 30 MHz, for example. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(3): 38–44, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20166