bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPUTATIONAL GENE KNOCKOUT REVEALS TRANSDISEASE–TRANSGENE ASSOCIATION STRUCTURE
Authors: MATSUNAGA TSUTOMU , KUWATA SHUHEI , MURAMATSU MASAAKI
Published: June 2010

Genome-wide association studies for a variety of diseases are identifying increasing numbers of candidate genes. Now we are confronted with the fact that some genes are common candidates across diseases. Thus there is a strong need to develop a hypothesis formulation methodology to comprehend multifaceted associations between genes and diseases. We have developed a computational method for building transdisease–transgene association structure. By introducing the basic rationale underlying the gene knockout approach as an information processing procedure to a network constructed on the basis of hyperlinks between disease and gene pages listed in the Online Mendelian Inheritance in Man (OMIM) database, relations of genes with diseases are computationally quantified. We did successively eliminate gene pages (called "computational gene knockout" in this paper) expected to contribute to metabolic syndrome, and catalogued each association with various disease pages. We thereby apply a co-clustering method to the gene–disease relations to obtain an association structure by classifying diseases and genes simultaneously. Observing an association structure between over 100 diseases and their related genes, we then found that the structure revealed gene classes that were commonly associated with diseases as well as gene classes that were selectively associated with a specific disease class.
Optical Properties of Evolutionary Grown Layers of Carbon Nanowalls Analyzed by Spectroscopic Ellipsometry
Authors: Kawai Shinji , Kondo Shingo , Takeuchi Wakana , Kondo Hiroki , Hiramatsu Mineo , Hori Masaru
Published: June 2010

Carbon nanowalls (CNWs), vertically standing graphene sheets, grown by the radical injection plasma-enhanced chemical vapor deposition system were analyzed by spectroscopic ellipsometry. The refractive indexes (n), extinction coefficients (k), and optical band gaps (E
g) of evolutionary growth layers were evaluated using the Tauc–Lorentz model with the effective medium approximation. It was observed that an amorphous carbon interfacial layer with n of 1.9–2.0 was formed prior to the growth of CNWs with n of 1.2–1.5. Moreover, the imaginary parts of complex dielectric functions analyzed using the Tauc–Lorentz model indicate the possibility that the CNWs have semiconducting features.
Dielectric Degradation and Reversible Domain Motion in Ferroelectric Thin Films Evidenced by Double-Butterfly Capacitance–Voltage Loops with Sweeping Times from 500 ns to 1 s
Authors: Jiang An-Quan , Tang Ting-Ao
Published: June 2010

Generally, the ferroelectric capacitance under a d.c. voltage drops continuously with time, and the shape of capacitance–voltage (C–V) loops within a sweeping time more than 1 s resemble a butterfly, in comparison to the double-butterfly shape of an antiferroelectric. In this work, we developed a measuring technique for shortening sweeping time down to 500 ns for the rapid study of dielectric relaxation in ferroelectric Pb(Zr,Ti)O3 thin films. It is interestingly found that the traditional butterfly loops of a ferroelectric degenerate into double butterfly loops of an antiferroelectric when the sweeping time is sufficiently short, providing evidence of the nonlinear dielectric contribution of reversible domain motion. Reversible domains can align along a field under a voltage, but reverses back immediately into their previous directions under a reduced field strength to release their polarization charges, similarly to antiferroelectric domains. When the voltage stressing time is sufficiently long, the internal field for driving reversible domain motion is temporally screened by the injected charges accumulated in regions with different polarizations, dielectric permittivities, and conductivities (domain pinning), which results in time-dependent dielectric degradation. This charge injection is different from the traditional model of defect motion with a low mobility. Finally, we showed evidence of the charge injection from the imprint profile and reversible domain freezing into irrecoverable domains upon cooling.
Second Phase and Defect Formation in Bi0.5Na0.5-xKxTiO3 Ceramics
Authors: Chen Pin-Yi , Chou Chen-Chia , Tseng Tseung-Yuen , Chen Haydn
Published: June 2010

The second phase and defect formation mechanisms of [Bi0.5(Na1-x
K
x
)0.5]TiO3 (BNKT100x) ceramics were investigated using electron microscopy, X-ray photoelectron spectroscopy (XPS), and electrical properties measurement. Experimental results indicated that second phase formation induces Bi-rich regions and compositional inhomogeneity within the matrix owing to the thermodynamic stability of potassium titanate. The Ti valence transition for BNKT ceramics sintered in air might be ascribed to the formation of secondary phase and low oxygen atmosphere, rather than simply attributed to the volatilization of bismuth. Li substitution at the A-site in BNKT ceramics suppresses formation of the second phase and Ti valence transition. Appropriate atmosphere control during material processing, such as sintering at higher oxygen pressure, and post oxidization annealing suppress oxygen vacancies and titanium valence transition, and therefore decrease the leakage current as well as improve electrical properties.
Hong–Ou–Mandel Dip Using Degenerate Photon Pairs from a Single Periodically Poled Lithium Niobate Waveguide with Integrated Mode Demultiplexer
Authors: Zhang Qiang , Takesue Hiroki , Langrock Carsten , Xie Xiuping , Fejer Martin M. , Yamamoto Yoshihisa
Published: June 2010

We experimentally observed a Hong–Ou–Mandle dip with photon pairs generated in a periodically poled reverse-proton-exchange lithium niobate waveguide with an integrated mode demultiplexer at a wavelength of 1.5 µm. The visibility of the dip in the experiment was 80% without subtraction of any noise terms at a peak pump power of 4.4 mW. The technology developed in the experiment can find various applications in the research field of linear optics quantum computation in fiber or quantum optical coherence tomography with near infrared photon pairs.
Energetics and Electronic Structure of Ultimate Silicon Nanowire Confined in Nanospace
Authors: Okada Susumu
Published: June 2010

We performed the first-principle total-energy calculations to investigate the energetics of the ultimate (3,0) Si nanotube encapsulated in carbon and boron–nitride nanotubes. Encapsulation of the Si nanotubes into carbon (C) and boron nitride (BN) nanotubes with sufficient thickness is exothermic and the resultant hybrid structures are metastable. Owing to the confinement effect, the Si nanotubes keep their tubular form possessing a higher total energy than the bulk Si crystal.
Preparation of Antireflection SiO2 Structures Based on Nanoimprinting Using Anodic Porous Alumina Molds
Authors: Yanagishita Takashi , Endo Takahide , Nishio Kazuyuki , Masuda Hideki
Published: June 2010

SiO2 pillar arrays with high aspect ratios were fabricated by nanoimprinting using ordered anodic porous alumina as a mold. The size and shape of SiO2 pillars could be controlled by changing the geometrical structures of the anodic porous alumina mold. The used of the obtained SiO2 fine patterns composed of ordered arrays of tapered pillars could effectively suppress the reflectance of incident light at the surface of the sample.
Electric Resistivity Measurements of Sb2Te3and Ge2Sb2Te5Melts Using Four-Terminal Method
Authors: Endo Rie , Maeda Shimpei , Jinnai Yuri , Lan Rui , Kuwahara Masashi , Kobayashi Yoshinao , Susa Masahiro
Published: June 2010

In this work, we aim to determine the electric resistivities of liquid Sb2Te3and Ge2Sb2Te5. Electric resistivities were measured using the four-terminal method. First, the electric resistivities of liquid Ga and Sn were measured to establish this method. Second, the electric resistivities of Sb2Te3and Ge1.6Sb2.0Te5.0were measured over temperature ranges between the respective melting temperatures of samples and 1020 K. The electric resistivity of Sb2Te3has been determined to be 4.36±0.14 µΩ m at 992 K. The uncertainty was determined on the basis of the guide to the expression of uncertainty in measurement. The electric resistivity of Ge1.6Sb2.0Te5.0is smaller than that of Sb2Te3. It is also found that both resistivities decrease with an increase in temperature; which indicates that both liquid materials behave as a semiconductor. Therefore, the pseudogap model was applied to derive the electrical activation energies.
Effect of Series Capacitance and Accumulated Charge on a Substrate in a Deposition Process with an Atmospheric-Pressure Plasma Jet
Authors: Ito Yosuke , Fukui Yutaka , Urabe Keiichiro , Sakai Osamu , Tachibana Kunihide
Published: June 2010

In order to investigate the effect of accumulated charge on a substrate surface in the deposition of a SiO2film with an atmospheric-pressure plasma jet, we have measured the discharge current flowing into a copper substrate, which was placed 20 mm from the exit of the plasma jet and connected to a variable capacitor in series. We found that the discharge current decreased markedly when the capacitance of the substrate was below 100 pF, and the deposition rate of SiO2traced the variation of the capacitance. To analyze the behavior of the plasma jet, we considered an equivalent circuit of our system and verified the validity of our supposition that the accumulated charge restricts the deposition rate. Thereby, we found that the discharge current and deposition rate were determined by the capacitance of both the glass tube wall and the substrate.
Effects of Postdeposition Annealing on Cobalt Nanodots Embedded in Silica for Nonvolatile Memory Application
Authors: Pei Yanli , Kojima Toshiya , Hiraki Tatsuro , Fukushima Takafumi , Tanaka Tetsu , Koyanagi Mitsumasa
Published: June 2010

We studied the effects of postdeposition annealing (PDA) on the films of cobalt nanodots (Co-NDs) dispersed in silica formed by self-assembled nanodot deposition (SAND). High-resolution transmission electron microscopy (HRTEM) analysis showed that the as-grown Co-NDs have a high density of 8×1012/cm2 and a small size of ∼1.5 nm. After PDA at 800 °C, a monolayer of Co-NDs is produced by agglomeration. Under this PDA condition, the dot size and density are easily controlled by adjusting the thickness of the as-grown Co-ND film. In contrast, a high-temperature PDA of 900 °C induces the diffusion of cobalt into the silicon substrate and leads to the failure of memory effect. When the PDA temperature is between 600 and 800 °C, a large counterclockwise hysteresis memory window is obtained. Furthermore, in this region, the charge retention is enhanced by increasing the PDA temperature, which presumably contributes to the release of oxygen from oxidized cobalt.
Fabrication of Large-Area Graphene Using Liquid Gallium and Its Electrical Properties
Authors: Fujita Jun-ichi , Miyazawa Yosuke , Ueki Ryuichi , Sasaki Mio , Saito Takeshi
Published: June 2010

We demonstrated a new process for synthesizing a graphene sheet at the interface between solid amorphous carbon and liquid gallium. The insolubility of carbon in gallium strongly restricted the depth of graphitization, but a multilayered graphene sheet having four to six layers of graphene was produced over the entire area of the interface immediately beneath the liquid gallium. We also demonstrated the operation of an electric-field-effect device fabricated on the multilayered graphene with a back-gated configuration, and a maximum conductance modulation of 40% was observed for an applied gate voltage ranging from -100 to +100 V.
Resist Residue in Ion Implantation Level Lithography
Authors: Ojima Tomoko , Asano Masafumi , Takahashi Masanori , Seino Yuriko , Mimotogi Shoji
Published: June 2010

We report the analysis of residual resist remaining after implantation level lithography on the topographical substrate. The problem experienced in a 45-nm-node complementary metal–oxide–semiconductor (CMOS) is described. From our experiment and simulation study, we found that switching exposure wavelength from argon fluoride (ArF) excimer lasers to krypton fluoride (KrF) excimer lasers ameliorates the issue of residual resist on gate stack substrates. In lithography over device stack such as gates, resolution cannot be explained by the Rayleigh equation's k
1. However, for the 32 nm node and below, ArF imaging has to be applied at ion implantation levels in view of the required resolution for a given mask layout. Therefore, we used a three-dimensional (3D) lithography simulator in order to clarify the mechanism of residual resist. From the analysis, the absorption of exposure light by sidewall materials is considered to be the reason for the residual resist. For the post-gate lithography at the ion implantation level, it is necessary to consider not only the resolution of the mask layout but the absorption of exposure light.
Skewness and Kurtosis Risks of Quality Control in Overlay Inspection
Authors: Sato Takashi , Ikeda Takahiro , Kasa Kentaro , Asano Masafumi , Sato Yasuharu
Published: June 2010

The population of overlay errors in layer-to-layer structures in semiconductor manufacturing often obeys non-normal distribution functions such as elliptic, rectangular, and skewed distributions. Thus, there can be many wrong diagnoses of quality control that can lead to consumer's risk and producer's risk. In a lot acceptance test, a product should be judged by variables rather than by attributes because of the small sample size. A new acceptance test by variables was introduced for a non-normal population. It included sample skewness and kurtosis as well as mean and standard deviations. Using operating characteristic (OC) curves, it was shown that sampling inspection by variables can be applied safely to a strong non-normal population with new variables.
Robust Control Design for Vibration Isolation of an Electron Beam Projection Lithography System
Authors: Wang Fu-Cheng , Hong Min-Feng , Yen Jia-Yush
Published: June 2010

This paper describes vibration control for an electron beam projection lithography (EPL) system. Two kinds of disturbances should be considered for an EPL: load disturbances from the machine and ground disturbances from the environment. However, the suspension settings for insulating these two disturbances conflict with each other. Therefore, we propose a double-layer optical table and apply disturbance response decomposing (DRD) techniques to independently control the disturbances. We use a passive control structure to isolate the ground disturbances, and an active control structure to suppress load disturbances. In addition, symmetric transformation is applied to decouple a full optical table into bounce/pitch and roll/warp half-table models, which can be further decoupled into quarter-table models to simplify controller design. Finally, we apply robust control techniques to design active controllers. From both simulation and experimental results, the designed H
∞ robust controllers are proven effective in reducing EPL system vibrations.
Negative-type extreme ultraviolet Resist Materials based on Water-Wheel-like Cyclic Oligomer (Noria)
Authors: Seki Hiroyuki , Kato Yuki , Kudo Hiroto , Oizumi Hiroaki , Itani Toshiro , Nishikubo Tadatomi
Published: June 2010

The synthesis and properties of noria derivatives containing oxetanyl groups were investigated for their application as negative-type extreme ultraviolet (EUV) resist materials. The solubility, film-forming ability, and photochemical reactivity were consistent with the structures of noria derivatives. The patterning properties of the synthesized noria derivatives were also examined using an EUV system, and patterns with 45 and 50 nm half-pitch resolution were obtained.
Preparation of Multilayer TiO2 Thin Films for Dye-Sensitized Solar Cells
Authors: Chang Ho , Chen Yu-Ling
Published: June 2010

We adopt TiO2 materials with three different morphologies to fabricate multilayer thin films for dye-sensitized solar cell (DSSC) photoelectrodes. The three different TiO2 morphologies are (1) titania nanotubes (Tnt) hydrothermally fabricated by 550 °C calcinating treatment to form an anatase phase (Tnt-C550), (2) TiO2 nanoparticles (H200) prepared by subjecting Tnt to two cycles of hydrothermal treatment, and (3) a TiO2 nanofluid (SF) fabricated by our developed submerged arc nanofluids synthesis system (SANSS). Experimental results showed that DSSCs fabricated with Tnt photoelectrodes tested with AM 1.5 light to simulate sunlight (100 mW/cm2) had a photoelectric conversion efficiency of 2.84%. The thin-film photoelectrode was prepared using Tnt-C550 calcined at 550 °C. Its photoelectric conversion efficiency increased to 5.77%. The photoelectric conversion efficiency of DSSCs with photoelectrodes fabricated using H200 reached 5.91%. Moreover, the photoelectric conversion efficiency of DSSCs with photoelectrodes prepared using SF reached 4.45%. Finally, the TiO2 materials with three different morphologies were used to prepare a three-layer photoelectrode with the structure of H200/Tnt-C550/SF, which was combined with a counter electrode to assemble DSSCs. These DSSCs had a photoelectric conversion efficiency of as high as 7.07%.
Poly(3-hexylthiophene)/Fullerene Organic Thin-Film Transistors: Investigation of Photoresponse and Memory Effects
Authors: Mohamad Khairul Anuar , Goto Keisuke , Uesugi Katsuhiro , Fukuda Hisashi
Published: June 2010

Organic thin-film transistors (OTFTs) incorporating blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) as an active layer were fabricated, and the photoresponse and memory effects of the P3HT/PCBM-TFTs were investigated. With top source–drain contact, the device exhibited a unipolar property with p-channel characteristics in dark condition. Upon illumination, a significant increase in the drain current was observed, and the transfer curve was shifted in the positive direction with ΔV
th = 15.5 V. Moreover, the drain current increased gradually with the response time of light illumination, while it decreased gradually with delay time after turning off the light illumination. The memory effects of the P3HT/PCBM-TFTs were attributed to the slow relaxation of photoinduced charge carriers and the electron trapping–detrapping mechanism. The memory functions of program and erase can be performed using a combination of the optical response and gate voltages.
Electrical Characteristics of TiSi2 Nanocrystal Nonvolatile Memory with Barrier-Engineered Tunnel Layer
Authors: Han Seung Jong , Lee Dong Uk , Seo Ki Bong , Kim Seon Pil , Kim Eun Kyu , Oh Jun-Seok , Cho Won-Ju
Published: June 2010

In this study, we fabricated TiSi2 nanocrystal nonvolatile memory devices with silicon nitride–oxide–nitride (NON) and SiO2 tunnel barriers. The TiSi2 nanocrystals with diameters of 2–5 nm and a density of 1.5 ×1012 cm-2 were formed using radio frequency magnetron sputtering in argon and a postannealing process. The memory effect of the TiSi2 nanocrystal memory device with the NON tunnel barrier was observed at about 0.7 V at 100 ms when the applied program/erase voltages were +7 V/-7 V. Also, the memory window of the NON tunnel barrier device was maintained up to 1.3 V after 103 s. These results indicate that the NON tunnel barrier provides an effective tunneling thickness for the fast program/erase speeds and an adequate physical thickness for long charge retention characteristics in nonvolatile memory devices.
Ionic Liquid Thin Film Fabrication Using Nano-Inkjet Printing Method
Authors: Kaisei Kiyohiro , Kobayashi Kei , Matsushige Kazumi , Yamada Hirofumi
Published: June 2010

Nanometer-scale liquid droplets and a liquid film patterned with a controlled thickness using an ionic liquid thin film were successfully deposited by a newly developed nanoinkjet printing method based on atomic force microscopy (AFM). Liquid droplets were locally deposited through an aperture with a diameter of 200 nm adjacent to an AFM tip by applying an electric field between a cantilever backside coating and a conductive substrate. The liquid film was fabricated by depositing an array of droplets with a spacing smaller than 70 nm and by the AFM tip effect. The deposited thin film has a layer-by-layer structure with a layer thickness of 4 nm. In addition, we also succeeded in the deposition of yoctoliter-scale liquid droplets, having only several tens of the liquid molecules inside, by applying an AC voltage.
Deposition Yield and Physical Properties of Carbon Films Deposited by Focused-Ion-Beam Chemical Vapor Deposition
Authors: Kaito Takashi , Oba Hiroshi , Sugiyama Yasuhiko , Yasaka Anto , Fujita Jun-ichi , Suzuki Tsuneo , Kanda Kazuhiro , Matsui Shinji
Published: June 2010

The deposition yield and physical properties of carbon films fabricated by focused-ion-beam (FIB) chemical vapor deposition were examined using several ion beam species of hydrogen, helium, xenon, and gallium. A gas-FIB was generated using an inductively coupled plasma ion source. It was found that the deposition yield is proportional to the total stopping power of the beam that penetrates into the carbon film. The physical properties of the carbon films deposited using gas-FIB are similar to those of films deposited using Ga-FIB, except for the Young's modulus.
Nanoscale Wet Etching of Physical-Vapor-Deposited Titanium Nitride and Its Application to Sub-30-nm-Gate-Length Fin-Type Double-Gate Metal–Oxide–Semiconductor Field-Effect Transistor Fabrication
Authors: Liu Yongxun , Kamei Takahiro , Endo Kazuhiko , O'uchi Shinichi , Tsukada Junichi , Yamauchi Hiromi , Hayashida Tetsuro , Ishikawa Yuki , Matsukawa Takashi , Sakamoto Kunihiro , Ogura Atsushi , Masahara Meishoku
Published: June 2010

The nanoscale wet etching of physical-vapor-deposited (PVD) titanium nitride (TiN) and its application to sub-30-nm-gate-length fin-type double-gate metal–oxide–semiconductor field-effect transistor (FinFET) fabrication are systematically investigated. It is experimentally found that PVD-TiN side-etching depth can be controlled to be one-half of PVD-TiN thickness with precise time control using an ammonium hydroxide (NH4OH) : hydrogen peroxide (H2O2) : deionized water (H2O) = 1 : 2 : 5 solution at 60 °C. Using the developed nanoscale PVD-TiN wet etching technique, sub-30-nm-physical-gate-length FinFETs, 100-nm-tall fin-channel complementary MOS (CMOS) inverters and static random access memory (SRAM) half-cells have successfully been fabricated and demonstrated. These experimental results indicate that the developed nanoscale PVD-TiN wet etching technique is very useful for tall fin-channel CMOS fabrication.
Preparation of Perylenediimide Nanoparticle Colloids by Laser Ablation in Water and Their Optical Properties
Authors: Yasukuni Ryohei , Hironaka Takayuki , Asahi Tsuyoshi
Published: June 2010

Fluorescent nanoparticles of N,N '-bis(2,5-di-tert-butylphenyl)-3,4,9,10-perylenedicarboximide (DBPI) were fabricated by laser ablation of its microcrystals dispersed in pure water, and their optical extinction and fluorescence spectra were investigated. Colloidal nanoparticles withmean sizes of 30 to 80 nm were prepared without molecular decomposition by tuning the fluence of the irradiating laser. Spectral simulation based on Mie theory explains the difference in the absorption spectra of the nanoparticles and a DBPI vapor-deposited film. The fluorescence of the nanoparticle colloids showed a monomer-like emission band with a vibrational structure, while the initial microcrystals exhibited a broad excimer band. These results indicate that the DBPI nanoparticles have crystal morphologies different from those of microcrystals.
Uncertainty Analysis on Precision Measurement for Polystyrene Nanospheres Using Dynamic Light Scattering
Authors: Pan Shan-Peng , Weng Han-Fu , Lin Chih-Min , Liu Tzong-Shi
Published: June 2010

Dynamic light scattering (DLS) is the most commonly used technique for measuring nanosphere sizes. In order to establish the traceability of the DLS method to SI units, relevant parameters have been measured in this study. Several studies have been reported on error sources in DLS. However, these studies lacked a systematic method of analyzing the uncertainty of DLS. In this paper we describe the DLS method and present a measurement uncertainty budget. Monodispersed polystyrene latex (PSL) spheres are selected as reference materials in the uncertainty evaluation. The measured nanosphere sizes are 20, 50, 100, 300, 500, and 1000 nm, among which the measurement results of 100, 300, and 500 nm nanospheres obtained using DLS are compared with those for an electrogravitational aerosol balance (EAB) method. The uncertainties for both methods are calculated, and the results of repeated measurements are presented with confidence levels of 95%.
Precision Measurement of Sub-50 nm Linewidth by Stitching Double-Tilt Images
Authors: Pan Shan-Peng , Liou Huay-Chung , Chen Chao-Chang A. , Chen Jr-Rung , Liu Tzong-Shi
Published: June 2010

In this paper we present a stitching double-tilt image method (SDTIM) to measure sub-50 nm linewidth and to evaluate the measurement uncertainty. The SDTIM employs a parallel image method using a tilt mechanism to obtain two side scans. Moreover, the stitching method is used for linewidth determination. Experiments were performed by atomic force microscopy (AFM) using an ultrasharp tip, whose radius is smaller than 5 nm. The sample rotation axis is set parallel to the top surface of the sample in order to reduce the problem of measurement position variation. Experimental results show that the developed SDTIM can be used with an uncertainty of less than 5 nm at a confidence level of 95%.
Growth Behavior of an Adsorbed Monolayer from a Benzophenone-Containing Trimethoxysilane Derivative on a Fused Silica Surface for Nanoimprint Molds by Chemical Vapor Surface Modification
Authors: Kubo Shoichi , Nakagawa Masaru
Published: June 2010

The formation of a monolayer from a benzophenone-containing trimethoxysilane derivative was studied to understand the growth behavior of an antisticking layer from a trimethoxysilane derivative with an alkyl long tail often used as an antisticking layer in nanoimprint lithography. An adsorbed monolayer was formed from 4-{[(3-trimethoxysilyl)propyl]oxy}benzophenone on a fused silica surface by chemical vapor surface modification (CVSM). The growth behavior of the adsorbed monolayer was monitored by UV–visible spectroscopy, and the results were compared with those obtained by contact angle measurement for water and atomic force microscopy. The monolayer formation was confirmed with absorption spectra showing a characteristic absorption band derived from a benzophenone moiety. Changes in contact angle and absorbance with an increase in CVSM period suggested that the monolayer formation was completed in 2 h. The period of 2 h suitable for CVSM was also supported by atomic force microscopy topographic images. These results suggested that the monolayer growth comprises the following three steps: the surface adsorption, condensation and packing, and excess adsorption steps.
Resist Properties of Thin Poly(methyl methacrylate) and Polystyrene Films Patterned by Thermal Nanoimprint Lithography for Au Electrodeposition
Authors: Nagase Koichi , Kubo Shoichi , Nakagawa Masaru
Published: June 2010

Gold (Au) line patterns of 0.5 and 1 µm widths were fabricated on a silicon substrate covered with a Au thin film by thermal nanoimprint lithography with poly(methyl methacrylate) (PMMA) and polystyrene (PS), followed by Au electrodeposition with their thin films as resist masks. We described the differences in the fidelity of the deposited Au patterns for linewidth and linewidth roughness and differences in undesired Au deposition in the masked regions between thin PMMA and PS films. The linewidths of the convex deposited Au pattern were larger than those of the concave nanoimprinted polymer pattern, and the deviation from the polymer concave pattern in the case of PS was significantly smaller than that in the case of PMMA. The linewidth roughness of the Au lines deposited with a PMMA mask was markedly high owing to particle-like Au deposition in comparison with that deposited with a PS mask. Undesired Au deposition occurred even on electrode surfaces masked with the thin PMMA and PS films. It was considered from these results that the difference in the size accuracy of Au electrodeposition between PMMA and PS was responsible for the resistance in the oxygen dry-etching step of a residual layer during thermal nanoimprint lithography in addition to polymer water absorbability in Au electrodeposition.
Direct Patterning on Sol–Gel Low-k Porous Silica by Thermal Nanoimprinting
Authors: Okada Makoto , Nakayama Takahiro , Kang Yuji , Haruyama Yuichi , Kanda Kazuhiro , Matsui Shinji
Published: June 2010

The direct patterning of low-dielectric constant (low-k) materials via nanoimprint lithography (NIL) has the potential to simplify fabrication processes and significantly reduce the manufacturing costs of semiconductor devices. It is known that a low k is realized by introducing a large number of nanoscale pores into a material. We demonstrated nanoimprinting on a sol–gel low-k material (k∼2.0) formed using methyl silicate as a siloxane oligomer source and surfactants as a pore template. As a result, 200-nm-linewidth mold patterns were successfully transferred onto the sol–gel low-k material by thermal nanoimprinting at 200 °C. However, pattern shrinkage was observed. The imprinted pattern linewidth was 180 nm. We assumed from the Fourier transform infrared spectroscopy (FT-IR) spectra of the sol–gel film before and after baking that the pattern shrinkage was induced by the condensation reaction.
Evaluation of Viscosity Characteristics of Spin-Coated UV Nanoimprint Resin
Authors: Atobe Hidemasa , Hiroshima Hiroshi , Wang Qing
Published: June 2010

The viscosity of a UV-curable resin used in UV nanoimprint is one of the key parameters to determine the process speed of resin filling in the recesses of a mold. We have developed an apparatus to measure the viscosity of a spin-coated thin liquid film on a wafer. With this viscosity measuring apparatus we examined the effect of the film thickness, exposure of resin to atmosphere, and temperature of resin on the viscosity of PAK-01, which is a UV-curable resin commonly employed in UV nanoimprint. The viscosity of this resin with its film thickness larger than 2.3 µm showed a constant value of 83 mPa·s, which is almost the same as that of the bulk PAK-01. At below 2.3 µm, the viscosity seemed to increase with decreasing film thickness. The viscosity of the spin-coated resin was also found to increase with the duration of its exposure to atmosphere; for a 30 min exposure to atmosphere, the viscosity reached up to 461 mPa·s. It is considered that during the prolonged exposure, the volatile component of the resin evaporated. When subjected to heat treatment, the viscosity of the UV-curable resin did not seem to depend on film thickness and maintained a steady value of 385 mPa·s. It was found that as the film thickness decreased the viscosity approached the value obtained by heat treatment.
Development of a High-Speed Real-Time Polymerase Chain Reaction System Using a Circulating Water-Based Rapid Heat-Exchange
Authors: Terazono Hideyuki , Takei Hiroyuki , Hattori Akihiro , Yasuda Kenji
Published: June 2010

Polymerase chain reaction (PCR) is a powerful technique to detect microorganisms, viruses, or cells by amplifying a single copy or a few copies of a fragment of a particular DNA sequence. To reduce acquisition time, it is necessary to decrease the temperature transition time between denaturation and extension. We have developed a simple rapid real-time microlitter-sample droplet PCR system accomplished by the rapid liquid-based heat-exchange of sample droplets by quick switching of two circulating hot waters of denaturation and extension, a microlitter-sized droplet and a thin-film aluminum chip. Using this system, rapid PCR amplification of a set of droplets lined up on an aluminum chip was conducted successfully as shown by the increase in fluorescence intensity, and was accomplished within 3.5 min in 40 cycles of 1 s denaturation and 3 s extension reaction, which is one magnitude faster than conventional fast PCR systems. This method allows the rapid detection of DNA fragments and has a possibility for measuring multiple samples simultaneously in a miniaturized microfluidic chip.
Fabrication of 150-nm-Wide Transducer Gaps for Disk-Type Resonators by Single Dry Etching Process
Authors: Murakami Sunao , Konno Mitsuo , Ikehara Tsuyoshi , Maeda Ryutaro , Mihara Takashi
Published: June 2010

We have newly designed and fabricated single crystal silicon (SCS) disk-type micromechanical resonators with 150-nm-wide vertical transducer gaps. The transducer gaps have been fabricated through a simple process including a single trench etching of SCS by deep reactive ion etching (D-RIE) with a resist mask patterned by electron beam lithography. The peak resonant frequencies measured for the fabricated resonators agreed well with those predicted by finite element simulations. Furthermore, the D-RIE process conditions for transducer gaps have been improved. Using the improved D-RIE process conditions, less tapered gaps of 2 µm deep were successfully fabricated for 100-, 150-, and 200-nm-wide gap patterns. The sidewall angle was from 88 to 89° depending on the gap width.
Development of Roll Micromold System via Deep X-ray Lithography and Metal Electroforming Processes
Authors: Lee Bong-Kee , Kwon Tai Hun
Published: June 2010

In the present study, a novel roll-shaped micromold system, referred to as a roll micromold system (RMS), is proposed and developed by a deep X-ray lithography process and subsequent electroforming. The developed RMS consists of several cylindrical roll micromold modules (RMMs) including various cross-sectional microstructures along their circumferential surface. RMMs with different microstructures are assembled to construct the RMS, which can be utilized in roll-type micromolding processes for the continuous replication of more complicated microstructured sheets and/or films. As a representative example of an RMS, several copper RMMs having triangular, rectangular, and trapezoidal microstructures on their circumferential surface were precisely fabricated. The RMS was successfully obtained by assembling such RMMs. A rolling experiment utilizing the assembled RMS was also carried out to verify its usefulness.
Development of Surface Acoustic Wave-Based Microgyroscope Utilizing Progressive Wave
Authors: Oh Haekwan , Yang Sangsik , Lee Keekeun
Published: June 2010

An 80 MHz surface acoustic wave (SAW)-based gyroscope utilizing a progressive wave was developed on a 128° YX LiNbO3 piezoelectric substrate. The sensor developed consists of two SAW oscillators in which one is used as the sensing element and has metallic dots in the cavity between input and output interdigital transducers (IDTs). The other is used as the reference element. Coupling of modes (COM) modeling was conducted to determine the optimal device parameters prior to fabrication. On the basis of the simulation results, the device was fabricated and then measured on a rate table. When the device was subjected to an angular rotation, oscillation frequency differences between the two oscillators were observed because of the Coriolis force acting on the metallic dots. Depending on the angular velocity, the difference in oscillation frequency was modulated. The obtained sensitivity was approximately 52.35 Hz deg-1 s-1 at an angular rate range of 0–1000 deg/s. Device performances at different mass weights, mass positions, and temperatures were characterized. Good thermal stability was also observed during the evaluation process.
Micromachined Silicon Disk Resonator Transduced by Piezoelectric Lead Zirconate Titanate Thin Films
Authors: Lu Jian , Suga Tadatomo , Zhang Yi , Itoh Toshihiro , Maeda Ryutaro , Mihara Takashi
Published: June 2010

Piezoelectrically transduced microelectromechanical system (MEMS) devices are promising candidates for use in distributed wireless sensor networks (WSN) to their low driving voltage and various sensing actuation capabilities. In this paper, we present a micromachined silicon disk resonator with on-disk piezoelectric lead zirconate titanate (PZT) thin films as both the actuator and sensor for human healthcare and safety applications. The resonator shows preferred system integration compatibilities, and the negative effects of the PZT-electrode stacks were compressed. A high quality factor was achieved both in air (∼1,300) and under vacuum (∼5,000). The effects of through-hole and other parameters on device sensitivity were examined and discussed in this paper.
The role of thrust tectonic models in understanding structural evolution in NW Scotland
Authors: Butler R. W. H.
Published: June 2010

The NW Highlands of Scotland have been an important test-bed for concepts in thrust tectonics. Here, research following the breakthrough publication of the 1907 memoir is reviewed, especially that relating to structural evolution in the Moine Thrust Belt. This belt was WNW-directed, involving cover sediments and thin sheets of crystalline basement. Displacements total 50–100 km within a branching array of thrusts. There are significant lateral variations in imbricate thrust geometry and localization behaviour. Following the application of linked thrust tectonic models in the 1980s significant attention has been directed at deducing thrust sequences, patterns of strain localization, folding styles and the significance of extensional tectonics as part of the structural evolution. The key has lain in deducing the kinematic linkages between thrusts and other structures, tracing displacements and examining the consequences of structural interpretations through geometric restoration. Thrusting models have been up-scaled to the crust. However, these linked kinematic approaches have been applied only hesitantly to the ductile structures of the Moine Thrust Sheet where structural research has focused on outcrop-scale deformation, especially of folds. Consequently, the larger-scale significance for Caledonian tectonics of thrust systems in the NW Highlands of Scotland has yet to be developed fully.
The geometric characteristics, genesis and petroleum significance of inversion structures
Authors: Cooper Mark , Warren Marian J.
Published: June 2010

Inversion structures are now recognized in most orogenic belts and in many other tectonic settings, however, this has not always been the case. For many years the thin-skinned paradigm dominated the interpretation of thrust belts which resulted in many inversion structures being erroneously interpreted as thin-skinned thrusts. In rift basins, intra-cratonic basins and on passive margins inversion structures were often interpreted as having alternative origins, for example, strike-slip deformation. The classic paper of Bally described the geometric characteristics of inversion structures, in which he identified the extensional fault geometry and its subsequent compressional reactivation as essential requirements of an inversion structure. The increased recognition of inversion structures in a wide variety of tectonic settings is illustrated by four hydrocarbon exploration case studies. The geometric characteristics of inversion structures are remarkably consistent irrespective of the tectonic setting and by applying a few simple criteria they can easily be identified. The impact of inversion on hydrocarbon prospectivity is a function of the control on the petroleum system elements from the initial extensional tectonic history and of the later compressional tectonic history which commonly creates new, or modifies old trap configurations.
The fractionation of phosphorus in some modern and late-Holocene calcareous tufas in North Yorkshire, UK
Authors: Pentecost Allan
Published: June 2010

Phosphorus fractionation studies were undertaken on seven UK tufas: three modern, and four old. The phosphorus in the carbonate fraction of the tufa averaged 19% of the total phosphorus in the modern material, and from 48–64% in the 4000 year-old deposits and the increase attributed to the mineralization of the contained organic matter. Two further phosphorus fractions contained significant amounts of P. The dithionite fraction ranged from 10–27% of the total, and most of this fraction was probably associated with detrital iron minerals. The alkali-soluble fraction which removed most of the organically-bound P was highest in the modern bryophyte tufas.

Total P levels in the tufas ranged from 33–119 ppm. These are low values for stream sediments. Phosphorus uptake rates into tufa were estimated for these sites. They were less than 5% of the incoming P and deemed to have a negligible effect on the aquatic biota.
In vitro
investigations of the impact of different temperature and flow velocity conditions on tufa microfabric
Authors: Pedley H. Martyn , Rogerson Mike
Published: June 2010

A series of experiments on freshwater carbonates (tufas) involving biofilm colonization in both fast-flow and slow-flow mesocosms was carried out in order to assess the changing nature of biofilm and associated precipitates under contrasting conditions. A thin biofilm developed over 14 weeks during the ‘summer’ experimental run contained a basal calcite layer overlain by small calcite crystals suspended within the Extracellular Polymeric Substances (EPS). The ‘autumn’ biofilm, however, showed the development of multi-laminated calcite precipitates within the EPS despite constant environmental conditions throughout the run. The experiments also showed that the largest volume of calcite precipitate developed in the fast-flow flumes regardless of temperature control. Development of an extensive calcite layer at the base of EPS in conditions of complete darkness within the sump was also observed. This study provides increased weight for the concepts: (1) that fresh- and saltwater stromatolites appear to be highly comparable multi-laminated systems with precipitation strongly influenced by both phototrophic and heterotrophic microbes; and (2) that microbial precipitation may be more common within aphotic (including cave, lake bottom and soil) systems than has previously been considered.
BMPR2 mutation alters the lung macrophage endothelin-1 cascade in a mouse model and patients with heritable pulmonary artery hypertension
Authors: Talati M. , West J. , Blackwell T. R. , Loyd J. E. , Meyrick B.
Published: June 2010

Macrophage derived-endothelin-1 (ET-1) has been suggested to contribute to a number of chronic lung diseases. Whether the ET-1 cascade from non-vascular sources (inflammatory cells) also contributes to pulmonary artery hypertension (PAH) and in particular to heritable PAH (HPAH) with known bone morphogenetic protein type 2 receptor (BMPR2) mutations is not known. We tested this notion using bone marrow-derived macrophages (BMDM; precursors of tissue macrophages) isolated from ROSA26rtTAXTetO7-tet-BMPR2R899Xmice (model of PAH with universal expression of a mutated BMPR2 gene) with and without activation by LPS and in human lung tissue from HPAH with BMPR2 mutations and idiopathic PAH (IPAH). At baseline ETAand ETBreceptors and endothelin converting enzyme (ECE) gene expression was reduced in BMPR2 mutant BMDM compared with controls. In control BMDM, LPS resulted in increased ppET-1 gene expression and ET-1 in culture media, whereas ETAand ETBreceptor and ECE gene expression was decreased. These findings were more severe in BMPR2 mutant BMDM. Antagonism of the ETBreceptor resulted in increased ET-1 in the media, suggesting that decreased ET-1 uptake by the ETBreceptor contributes to the elevation. While ET-1 expression was demonstrated in lung macrophages from controls and IPAH and HPAH patients, ETAand ETBexpression was decreased in the HPAH, but not IPAH, patients compared with controls. We conclude that reduced expression of macrophage ET-1 receptors in HPAH increases lung ET-1 and may contribute to the pathogenesis and maintenance of HPAH. This is the first description of protein expression that distinguishes HPAH from IPAH in patients.
TRPV4 channels augment macrophage activation and ventilator-induced lung injury
Authors: Hamanaka Kazutoshi , Jian Ming-Yuan , Townsley Mary I. , King Judy A. , Liedtke Wolfgang , Weber David S. , Eyal Fabien G. , Clapp Mary M. , Parker James C.
Published: June 2010

We have previously implicated transient receptor potential vanilloid 4 (TRPV4) channels and alveolar macrophages in initiating the permeability increase in response to high peak inflation pressure (PIP) ventilation. Alveolar macrophages were harvested from TRPV4−/−and TRPV4+/+mice and instilled in the lungs of mice of the opposite genotype. Filtration coefficients ( Kf) measured in isolated perfused lungs after ventilation with successive 30-min periods of 9, 25, and 35 cmH2O PIP did not significantly increase in lungs from TRPV4−/−mice but increased >2.2-fold in TRPV4+/+lungs, TRPV4+/+lungs instilled with TRPV4−/−macrophages, and TRPV4−/−lungs instilled with TRPV4+/+macrophages after ventilation with 35 cmH2O PIP. Activation of TRPV4 with 4-α-phorbol didecanoate (4αPDD) significantly increased intracellular calcium, superoxide, and nitric oxide production in TRPV4+/+macrophages but not TRPV4−/−macrophages. Cross-sectional areas increased nearly 3-fold in TRPV4+/+macrophages compared with TRPV4−/−macrophages after 4αPDD. Immunohistochemistry staining of lung tissue for nitrotyrosine revealed increased amounts in high PIP ventilated TRPV4+/+lungs compared with low PIP ventilated TRPV4+/+or high PIP ventilated TRPV4−/−lungs. Thus TRPV4+/+macrophages restored susceptibility of TRPV4−/−lungs to mechanical injury. A TRPV4 agonist increased intracellular calcium and reactive oxygen and nitrogen species in harvested TRPV4+/+macrophages but not TRPV4−/−macrophages. Kfincreases correlated with tissue nitrotyrosine, a marker of peroxynitrite production.
On the Measurement of the (Non)linearity of Costas Permutations
Authors: Drakakis Konstantinos
Published: June 2010

We study several criteria for the (non)linearity of Costas permutations, with or without the
imposition of additional algebraic structure in the domain and the range of the permutation, aiming
to find one that successfully identifies Costas permutations as more nonlinear than randomly chosen
permutations of the same order.
and : Critical Residues for In Vitro Biological Activity of Reteplase
Authors: Mandi Naganath , Sundaram Kalyana R. , Tandra Sunil K. , Bandyopadhyay Suman , Padmanabhan Sriram
Published: June 2010

Reteplase (rPA) is a thrombolytic agent used for the treatment of acute myocardial infarction. We studied the expression of rPA and its selected asparagine mutants after integration into thePichiagenome. Though methanol induction of the native and the rPA mutants showed similar expression levels (~200–250 mg/L), the mutants displayed significant loss of protease activity. Strikingly, the clot lysis activities of these mutants were considerably different. While mutation of (N12P) of the Kringle 2 domain showed delayed clot lysis activity ( min) compared to the native rPA ( min), a faster rate of clot lysis ( min) was observed when the (N278S) of the serine protease domain was mutated. Interestingly, the slowest clot lysis activity ( min) demonstrated by the double mutant (N12P, N278S) suggests the dominant role of in regulating the fibrinolytic activity of rPA. The results presented in this paper indicate that the fibrinolytic and the proteolytic activities of rPA are independent of each other.