bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Oxygen Impurities on Thermal Diffusivity of AlN Thin Films Deposited by Reactive RF Magnetron Sputtering
Authors: Yagi Takashi , Oka Nobuto , Okabe Takashi , Taketoshi Naoyuki , Baba Tetsuya , Shigesato Yuzo
Published: November 2011

The thermal diffusivities of AlN thin films with a thickness of about 600 nm deposited by reactive rf magnetron sputtering were measured by the pulsed light heating thermoreflectance technique. The AlN films contain oxygen impurities ranging from 1.1 to 13.6 at. % depending on the sputtering conditions. The measured thermal diffusivity increases from 1.5×10-6 to 12×10-6 m2 s-1 with the decrease in oxygen concentration. An X-ray diffraction study shows that the AlN lattice parameter of the c-axis decreases with the increase in oxygen concentration. The average crystal diameter of the AlN films derived from the X-ray diffraction peaks is 41 nm. The dependence of the thermal conductivity of the AlN films on the oxygen concentration was discussed on the basis of the thermal resistance induced by oxygen impurities and phonon scattering by grain boundaries.
Thermal Boundary Resistance between N,N '-Bis(1-naphthyl)-N,N '-diphenylbenzidine and Aluminum Films
Authors: Oka Nobuto , Kato Kazuki , Yagi Takashi , Taketoshi Naoyuki , Baba Tetsuya , Shigesato Yuzo
Published: November 2011

To determine the thermal boundary resistance between N,N '-bis(1-naphthyl)-N,N '-diphenylbenzidine (α-NPD) and aluminum (Al) films, we prepared α-NPD films sandwiched between Al films (Al/α-NPD/Al); the nominal thicknesses of the α-NPD and Al films were 1–30 and 74 nm, respectively. Then, we used “rear heating/front detection type” picosecond and nanosecond thermoreflectance systems to directly observe the heat transfer through the film thickness. We found that the thermal boundary resistance between α-NPD and Al was 3.5 ×10-9 m2 K W-1, corresponding to the thermal resistance of a 0.9-nm-thick α-NPD film or a 720-nm-thick Al film.
Representation of the Viscosity of Molten Alloy as a Function of the Composition and Temperature
Authors: Sato Yuzuru
Published: November 2011

Although the viscosity of molten metal is very important, the measurement is considerably difficult for high temperature melts. The author's group has developed an oscillating viscometer for high temperature metal. The prediction of the viscosity behavior of the alloys is most useful task because the experimental data acquisition is not easy. In the prediction process, important issue is the composition and temperature dependence. The author has found that the additivity of the logarithmic viscosity was dominant criteria on the composition dependence based on the result of Fe–Si binary melt. Therefore, the logarithmic additivity was adapted to some nickel based super-alloys which were multi component systems. The viscosities of nickel based five binary melts were measured for the representation of the viscosities of super-alloys. The formulation was done by using the separation of variables method. The pre-exponential term and the activation energy were separately approximated as a function of the composition. The results of the approximation successfully represented the viscosities of molten super-alloys.
Density of Multicomponent Melts Measured by Electromagnetic Levitation
Authors: Brillo Jürgen , Egry Ivan
Published: November 2011

A significant amount of time and costs could be saved on the development of new materials through numerical modeling, if there was an understanding on how their thermophysical properties change with a change of composition. Here, we report on systematic measurements of the density for a number of liquid metallic alloys. These measurements were carried out containerlessly using the technique of electromagnetic levitation. Systems were investigated from mono-atomic liquid metals, to binary and ternary alloys. The results are discussed using the excess volume as the key mixing parameter. We found that there is no strict rule for liquid alloys, whether or not the excess volume should be positive, negative, or zero. However, a clear tendency was observed: immiscible systems tend to exhibit a positive excess volume, strongly mixing systems show a negative excess volume, and alloys of which the components are chemically similar, exhibit an excess volume of almost zero.
Relationship of Surface Tension, Oxygen Partial Pressure, and Temperature for Molten Iron
Authors: Ozawa Shumpei , Takahashi Suguru , Suzuki Shoji , Sugawara Hiroharu , Fukuyama Hiroyuki
Published: November 2011

Surface tension of molten iron was measured under reducing gas atmosphere of Ar–He–5 vol % H2 by an oscillating droplet method using electromagnetic levitation. The temperature dependence of surface tension did not exhibit a linear relationship but revealed a peculiar kink at around 1810 K, due to competition between the temperature dependence of oxygen partial pressure and that of the oxygen adsorption equilibrium constant. We successfully derived the surface tension of molten iron as functions of both oxygen partial pressure and temperature. Furthermore, the standard enthalpy and entropy for oxygen adsorption reaction on molten iron were also estimated.
Evaluation System for Figure of Merit of Thermoelectric Devices
Authors: Kwon Su Yong , Kim Yong-Gyoo , Lee Sanghyun , Kim Jong Chul
Published: November 2011

The apparatus for evaluation of the figure of merit (ZT) of thermoelectric devices has been developed in order to investigate the performance of the thermoelectric devices.ZTvalue is comprised of three physical quantities, Seebeck coefficient, electrical conductivity, and thermal conductivity. In this study, we present new apparatus developed for evaluating theZTand power generation efficiency of devices by direct measurement of thermal conductivity using guarded hot plate (GHP) method. The measuredZTvalues and power generation efficiency of the thermoelectric devices are presented.
Emissivity Compensation Utilizing Radiance Distribution in Thermal Images for Temperature Measurement of Electronic Devices
Authors: Yamada Yoshiro , Ishii Juntaro
Published: November 2011

Two novel techniques of compensating for unknown distributed emissivity in temperature measurement by thermal imagers are presented. For both techniques the reflected image of a planar auxiliary source is superimposed on the thermal image of the object. In the first, the true temperature of the object is obtained by treating it as a blackbody when the radiance distribution, corresponding to emissivity pattern of the object, disappears. In the second, the reflectance ratio at two areas in the thermal image is utilized to compensate for emissivity. In this paper, principle of the emissivity compensation and preliminary test results are presented, and the procedures and their capabilities are demonstrated. The features of the schemes, such as elimination of the size-of-source effect, are discussed. The method is expected to become powerful tools for temperature distribution measurements in various applications, most notably the monitoring of local heat generation in highly-integrated or power electronic devices.
Specific Heat Capacity of Gallium Nitride
Authors: Lee Sanghyun , Kwon Su Yong , Ham Hye Jeong
Published: November 2011

The specific heat capacity of gallium nitride (GaN) was measured for polycrystalline powder and single crystal samples. We present the temperature dependence of the specific heat capacity for single crystal and powdered GaN from 100 to 1300 K. The difference between the polycrystalline powder and single crystal arises from thermal evaporation in the high-temperature region, and this depends on the degree of heat transfer at 100–200 K. The temperature dependence of the specific heat capacity in the form c

p
= 7.1380 ×10-17
T
6 - 2.9836 ×10-13
T
5 + 4.2185 ×10-10
T
4 - 1.5068 ×10-7
T
3 - 1.6713 ×10-4
T
2 + 0.1774T - 1.3545 (J mol-1 K-1) was derived from a least squares fitting routine.
Inorganic Materials Database for Exploring the Nature of Material
Authors: Xu Yibin , Yamazaki Masayoshi , Villars Pierre
Published: November 2011

An inorganic materials database system, AtomWork, has been developed and released on the Internet. It includes the phase diagram, crystal structure, X-ray powder diffraction, and property data of more than 80,000 inorganic materials extracted from scientific literature. The feature of this database is that the information of the synthesis, identification, and property of materials is organically linked, which enables the data reported in different papers to be grouped and compared at four different levels: chemical system, compound, substance, and material. The database can provide users with a comprehensive overview of substances and necessary information to understand the relationships among chemical component, structure, and property.
Microstructure of Bulk AlN Grown by A New Solution Growth Method
Authors: Kangawa Yoshihiro , Kuwano Noriyuki , Epelbaum Boris M. , Kakimoto Koichi
Published: November 2011

We used transmission electron microscopy to analyse the microstructures in a thick AlN layer grown on a self-nucleated, columnar AlN seed crystal. The growth direction of the AlN layer grown by a new solution growth method was [1100]. The threading dislocation (TD) density near the epilayer-seed interface (on the seed crystal) was 109 cm-2. However, owing to dislocation annihilation, the TD density decreased to 108 cm-2 at a thickness of ∼5 µm. These results imply that the new solution growth method can grow high-crystalline-quality bulk AlN under moderate growth conditions (T ≈1200 °C, nitrogen pressure = 1 atm).
Electrical Stability of Power Efficient Half Corbino Hydrogenated Amorphous Silicon Thin-Film Transistors
Authors: Lee Hojin , Jung Hyunseung , Choi Keun-Yeong , Kanicki Jerzy
Published: November 2011

In this paper, we study the electrical properties and current-temperature stress (CTS) induced electrical instability of half Corbino and fork-shaped hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) fabricated on the same substrate. The influence on overall electrical properties of the threshold voltage shift of half Corbino a-Si:H TFT is discussed in comparison to fork-shaped a-Si:H TFT. The results indicate that half Corbino a-Si:H TFT has improved ON-current levels and electrical stability in comparison to fork-shaped a-Si:H TFT with the similar structural dimension.
Effect of Cu/In Ratio in Crystal Growth of CuInSe2 Thin Films Fabricated by Reduction and Selenization Using Cu and In2O3 Paste Materials
Authors: Tsutsumi Keiji , Minemoto Takashi , Uzawa Koichi , Yaginuma Kiyoshi , Makuta Fujio , Takakura Hideyuki
Published: November 2011

Chalcopyrite CuInSe2 thin films were formed from paste precursors including Cu and In2O3 fine particles. The compositions of the pastes were In- and Cu-rich. Paste was coated on Mo/soda-lime glass by screen printing. The precursors were annealed at 450 °C under N2:H2 (97:3) ambient to reduce them. The reduced films consisted of the Cu11In9 and In phases. The reduced precursor showed granular shape and poor adhesion with the Mo layer because the melting point of Cu11In9 was about 300 °C and Cu11In9 does not wet with Mo. The reduced precursors were annealed at 600 °C under Se and Ar ambient to form the CuInSe2 thin films. The In-rich CuInSe2 thin film consisted of small grains. The Cu-rich CuInSe2 thin film was dense and consisted of large grains of about 3 µm.
Proposal for a Novel Bistable Device Using Two-Mode Competition between an In-Plane Laser Diode and a Vertical-Cavity Surface-Emitting Laser
Authors: Nomiyama You , Kobayashi Kohroh , Uenohara Hiroyuki
Published: November 2011

On the basis of mode competition, we propose a novel bistable device that has the potential to improve the degrees of freedom of optical input-output directions. Unlike the conventional mode competition in a single cavity, the proposed device uses two cavities that are cross-coupled between an in-plane laser diode (LD) and a vertical-cavity surface-emitting laser (VCSEL). We calculated rate equations using the cross-gain saturation model in order to elucidate the conditions under which the proposed device may have bistability. We also analyzed the static and dynamic responses. From the calculations, we found that the product of the optical confinement factor and the photon lifetime of the two lasers should have almost equal values. The results show that by coupling two cavities having similar characteristics, the switching characteristic becomes comparable to those of other reported bistable devices. In the case of static operations, switching powers of less than 2 mW and about 20 fJ could be achieved; these are some of the smallest operational performances.
Optical Modeling and Analysis of Organic Solar Cells with Coherent Multilayers and Incoherent Glass Substrate Using Generalized Transfer Matrix Method
Authors: Jung Sungyeop , Kim Kyoung-Youm , Lee Yeon-Il , Youn Jun-Ho , Moon Hie-Tae , Jang Jin , Kim Jungho
Published: November 2011

We present optical modeling and physical analysis results of thin-film organic solar cells (OSCs) based on a generalized transfer matrix method, which can calculate, with a simple matrix form, the mixed coherent and incoherent interaction of an incoherent glass substrate with other coherent layers. The spatial distribution of the electric field intensity, power density, and power dissipation are calculated in both coherent and incoherent layers with respect to the optical spacer thickness. By decomposing the power density and power dissipation into forward-propagating, backward-propagating, and their interference components, we demonstrate that the dependence of the spacer thickness on the total device reflectance plays an important role in determining the light absorption efficiency of the OSC.
Cation Extraction Process in Bilayer Cyanide Film as Investigated by Depth-Resolved X-ray Absorption Spectroscopy
Authors: Omura Ayako , Kurihara Yutaro , Matsuda Tomoyuki , Tanida Hajime , Uruga Tomoya , Moritomo Yutaka
Published: November 2011

The cation extraction process in the bilayer cyanide film with an epitaxial interface, Na0.84-y
Co2+[Fe
y

3+Fe1-y

2+(CN)6]0.713.8H2O (NCF71)/Na1.60-x
(Co
x

3+Co1-x

2+)[Fe2+(CN)6]0.902.8H2O (NCF90), was investigated by depth-resolved X-ray absorption spectroscopy. Assuming stepwise depth (z) distributions of Co3+ and Fe3+, we estimated the step depths, d
Co and d
Fe, and concentrations, δCo and δFe, of the respective ions against the average quantity (δav) of cation extraction. The Na+ extraction was found to be dominant in the NCF90 surface layer, consistent with the lower redox potential in the NCF90 layer. We found that the magnitude of d
Fe (∼600 nm) is much deeper than the actual depth (d = 200 nm) of the NCF71/NCF90 interface, and interpreted the behavior in terms of the redox interaction in the vicinity of the interface.
Analysis of Dose-Pitch Matrices of Line Width and Edge Roughness of Chemically Amplified Fullerene Resist
Authors: Kozawa Takahiro , Oizumi Hiroaki , Itani Toshiro , Tagawa Seiichi
Published: November 2011

The resist materials are evaluated using their resolution, line edge roughness (LER), and sensitivity. However, the evaluation of chemically amplified resists is tricky because of the trade-off relationships between resolution, LER, and sensitivity. In this study, we investigated a chemically amplified resist with a fullerene matrix by analyzing the dose-pitch matrices of line width and LER. The effective quencher concentration of the fullerene resist obtained by the analysis was higher than those of typical polymer-type resists. This suggests that the quantum efficiency of acid generation in the fullerene matrix is slightly lower than those of polymer-type resists. The effective reaction radius was 0.06 nm, which was smaller than those of polymer-type resists. The proportionality constant between LER and the chemical gradient of the fullerene resist was smaller than those of polymer-type resists, probably owing to its molecular size.
Nanoimprint Molds with Circumferentially Aligned Patterns Fabricated by Liftoff Process
Authors: Okada Takeru , Fujimori Jiro , Iida Tetsuya
Published: November 2011

A liftoff process was used to fabricate nanoimprint molds with dense patterns below 50 nm pitch. Circumferentially aligned patterns were defined by electron-beam lithography (EBL) using an electron-beam recorder with a rotary stage. Undercut profiles suitable for liftoff were fabricated by etching multilayered resist systems that use a hydrogen silsesquioxane (HSQ) layer as an etching mask for the underlying resin, and liftoff was performed by dissolving the HSQ layer on an insoluble resin layer. By using an undercut profile that was formed in a trilayered stack after EBL, a mold with high-density (42 nm pitch) and large-area (2.5 in.) pillar patterns was fabricated. Quartz replica molds were also fabricated by the liftoff process combined with UV nanoimprint. It was possible to fabricate molds with both a positive tone and a negative tone, and the fabrication of a replica mold with pillar patterns (49 nm pitch) was demonstrated.
Growth of Cu2ZnSnS4 Single Crystal by Traveling Heater Method
Authors: Nagaoka Akira , Yoshino Kenji , Taniguchi Hiroki , Taniyama Tomoyasu , Miyake Hideto
Published: November 2011

A Cu2ZnSnS4 (CZTS) single crystal was grown at 900 °C, which is less than its melting point (962 °C) using a traveling heater method, which is one of the solution growth methods. No twins and no secondary phases could be distinguished from the Laue and X-ray diffraction patterns, respectively.
Software model checking using languages of nested trees
Authors: Alur Rajeev , Chaudhuri Swarat , Madhusudan P.
Published: November 2011

While model checking of pushdown systems is by now an established technique in software verification, temporal logics and automata traditionally used in this area are unattractive on two counts. First, logics and automata traditionally used in model checking cannot express requirements such as pre/post-conditions that are basic to analysis of software. Second, unlike in the finite-state world, where the μ-calculus has a symbolic model-checking algorithm and serves as an “assembly language” to which temporal logics can be compiled, there is no common formalism—either fixpoint-based or automata-theoretic—to model-check requirements on pushdown models. In this article, we introduce a new theory of temporal logics and automata that addresses the above issues, and provides a unified foundation for the verification of pushdown systems.

The key idea here is to view a program as a generator of structures known as
nested trees
as opposed to trees. A fixpoint logic (called N
T
-μ) and a class of automata (called
nested tree automata
) interpreted on languages of these structures are now defined, and branching-time model-checking is phrased as language inclusion and membership problems for these languages. We show that N
T
-μ and nested tree automata allow the specification of a new frontier of requirements usable in software verification. At the same time, their model checking problem has the same worst-case complexity as their traditional analogs, and can be solved symbolically using a fixpoint computation that generalizes, and includes as a special case, “summary”-based computations traditionally used in interprocedural program analysis. We also show that our logics and automata define a robust class of languages—in particular, just as the μ-calculus is equivalent to alternating parity automata on trees, NT-μ is equivalent to alternating parity automata on nested trees.
Bottom-up shape analysis using LISF
Authors: Gulavani Bhargav S. , Chakraborty Supratik , Ramalingam G. , Nori Aditya V.
Published: November 2011

In this article, we present a new shape analysis algorithm. The key distinguishing aspect of our algorithm is that it is completely compositional, bottom-up and noniterative. We present our algorithm as an inference system for computing Hoare triples summarizing heap manipulating programs. Our inference rules are compositional: Hoare triples for a compound statement are computed from the Hoare triples of its component statements. These inference rules are used as the basis for bottom-up shape analysis of programs.

Specifically, we present a Logic of Iterated Separation Formulae (LISF), which uses the iterated separating conjunct of Reynolds [2002] to represent program states. A key ingredient of our inference rules is a strong bi-abduction operation between two logical formulas. We describe sound strong bi-abduction and satisfiability procedures for LISF.

We have built a tool called S
p
I
n
E that implements these inference rules and have evaluated it on standard shape analysis benchmark programs. Our experiments show that S
p
I
n
E can generate expressive summaries, which are complete functional specifications in many cases.
The grounding practice
Authors: Denning Peter J.
Published: November 2011

The skill of making and recognizing grounded claims is essential for professional practice. Getting objective data to support your conclusions is not enough.
Answer set programming at a glance
Authors: Brewka Gerhard , Eiter Thomas , Truszczyński Mirosław
Published: November 2011

The motivation and key concepts behind answer set programming---a promising approach to declarative problem solving.
Doctoral program rankings for U.S. computing programs
Authors: Bernat Andrew , Grimson Eric
Published: November 2011

A proposal for improving doctoral program ranking strategy.
Fuzzy cognitive map based approach for software quality risk analysis
Authors: Bhatia Nitin , Kapoor Namarta
Published: November 2011

This paper presents a software risk prediction tool for risk analysis during the development of a software product. The term "Risk" refers to a problem that can threaten the success of the software project but has not happened yet. Risks are uncertain. The main objective of each organization is to provide very high quality software to their customers. The term "Quality" is a value to the person. But there is a long list of software risks that can have adverse impact on the quality of the software. It is necessary to address all the risks; otherwise, they may lead to undesireable results. Fuzzy Cognitive Maps (FCMs) describe different concepts with different aspects of the behaviour of complex systems. A software tool based upon FCM has been developed for assessing software risks. This paper describes the reasoning behind the focus on risk management during the software development process and its importance in delivering high quality software by assessing software risks during the development process using fuzzy cognitive maps.
Measuring bug complexity in object oriented software system
Authors: Khatri Sujata , Chhillar R. S. , Singh V. B.
Published: November 2011

Bugs are inevitable in any software development life cycle. Most bugs are detected and removed in the testing phase. In software, we can classify bugs into two categories: (1) bugs of different severity, from a user's perspective,(how much damage the bug does) and (2) bugs of different complexity(how much is the debugging time lag between detection and correction). Prior knowledge of bug distribution of different complexity can help project managers in allocating testing resources and tools. Various researchers have proposed models for determining the proportion of bugs present in software of different complexity but none of these models have been applied to object oriented software. In this paper, we have proposed a model that will determine the proportion of different bug complexity. The paper also suggests the suitability of the proposed model for a particular data set. We have taken two data sets based on object oriented methodology namely SQL for Python and SQuirreL SQL Client software developed under open source environment.
Industry linked graduate software engineering curriculum
Authors: Mishra Alok , Mishra Deepti
Published: November 2011

In recent years, Software Engineering (SE) has emerged as an independent and mature discipline. In this context, various studies are being done to provide guidelines for undergraduate about graduate software engineering curriculum design. This article presents need of software industry related courses and discusses significance of industry linked software engineering education to meet educational objectives of all stakeholders. Software industry oriented curriculum for graduate level are discussed. Software industry aligned courses will facilitate to increase their employment prospects in industrial and other sectors.
Identifying structural similarity of methods using isomorphic graphs
Authors: Tee Sim-Hui
Published: November 2011

It is a recommended practice to use overloaded methods in a class for a group of similar operations and functions. However, it is possible that software developers may violate the rule of overloaded methods. In addition, non-overloaded method is used incorrectly sometimes in composing similar functions. This paper presents a technique, using isomorphic graphs, to identify structural similarity between class methods.
Coevolution of information ecosystems
Authors: Yu Liguo
Published: November 2011

With the increasing use of information technology, information ecosystems have emerged. Information ecosystems not only include software products, but also include hardware products. For example, application software depends on system software, and both application software and system software depend on hardware devices. Together, they play important roles in an information ecosystem. This paper analyzes the coevolution of information ecosystem, where three representatives of computer hardware, system software, and application software products are studied. Specifically, we analyze (1) the growth rate of Intel processors, Linux operating systems, and Apache web servers; and (2) the statistical relations among the evolution of Intel processors, Linux operating systems, and Apache web servers. Our study finds that a system software product grows slower than its supporting hardware products and a application software product grows slower than its supporting system software and hardware products.
Synthesis and Characterization of the Ligand Based on Benzimidazole and Its Copper Complex: DNA Binding and Antioxidant Activity
Authors: Wu Huilu , Kou Fan , Jia Fei , Liu Bin , Yuan Jingkun , Bai Ying
Published: November 2011

A new copper(II) complex with formulae of [Cu(buobb)2](pic)2, where buobb stands for the ligand of 1,3-bis(1- butylbenzimidazol-2-yl)-2-oxopropane and pic represents 2,4,6-trinitrophenol, has been synthesized and characterized by elemental analyses, molar conductivity, IR, UV-Vis spectra measurements, and cyclic voltammetry. The crystal structure of the copper(II) complex has been determined by X-ray single-crystal diffraction. The coordination environment around each copper(II) atom can be described as a distorted octahedral geometry. The π-π stacking interactions link the copper(II) complex into a 1D infinite network. The interactions of the ligand and the copper(II) complex with calf thymus DNA (CT-DNA) are investigated by using electronic absorption titration, ethidium bromide-DNA displacement experiments, and viscosity measurements. Additionally, the copper(II) complex’s antioxidant properties have been investigated in vitro.
Novel Therapeutic Strategies for Malignant Salivary Gland Tumors: Lessons Learned from Breast Cancer
Authors: Murase Ryuichi , Sumida Tomoki , Ishikawa Akiko , Murase Rumi , McAllister Sean D. , Hamakawa Hiroyuki , Desprez Pierre-Yves
Published: November 2011

Malignant salivary gland tumors (MSGTs) account for 2–6% of all head and neck cancers. Despite the rarity, MSGTs have been of great interest due to a wide variety of pathological features and high metastasis rates resulting in poor prognosis. Surgical resection followed by radiation therapy represents the main treatment of this malignancy. Adjuvant therapy is reserved for the management of local recurrence, no longer amenable to additional local therapy, and for metastasis. Based on the studies from other types of tumors, particularly breast cancer, the expression and function of sex steroid hormone receptors in cancer have been extensively studied and applied to diagnosis and treatment. Although a number of studies in MSGTs have been published, the rationale for hormone therapy is still controversial due to the disparate results and insufficient number of cases. However, some recent reports have demonstrated that certain salivary gland neoplasms are similar to breast cancer, not only in terms of the pathological features, but also at the molecular level. Here, we shed light on the biological similarity between MSGTs and certain types of breast cancer, and describe the potential use of hormone and additional therapies for MSGTs.
Coal Depolymerising Activity and Haloperoxidase Activity of Mn Peroxidase fromFomes durissimusMTCC-1173
Authors: Singh Sunil Kumar , Yadav Meera , Yadava Sudha , Yadav Kapil Deo Singh
Published: November 2011

Mn peroxidase has been purified to homogeneity from the culture filtrate of a new fungal strainFomes durissimusMTCC-1173 using concentration by ultrafiltration and anion exchange chromatography on diethylaminoethyl (DEAE) cellulose. The molecular mass of the purified enzyme has been found to be 42.0 kDa using SDS-PAGE analysis. The values using MnSO4and H2O2as the variable substrates in 50 mM lactic acid-sodium lactate buffer pH 4.5 at were 59 μM and 32 μM, respectively. The catalytic rate constants using MnSO4and H2O2were 22.4 s−1and 14.0 s−1, respectively, giving the values of 0.38 μM−1s−1and 0.44 μM−1s−1, respectively. The pH and temperature optima of the Mn peroxidase were 4 and , respectively. The purified MnP depolymerises humic acid in presence of H2O2. The purified Mn peroxidase exhibits haloperoxidase activity at low pH.
Molecular Pathology of Gastric Carcinoma
Authors: Jang Bo-Gun , Kim Woo Ho
Published: November 2011

Gastric carcinoma (GC) is a biologically heterogeneous disease involving numerous genetic and epigenetic alterations. A very small proportion of GCs can be caused by a specific germ-line mutation of the E-cadherin gene (CDH1). Sporadic GC is developed through multistep processes that begin with Helicobacter pylori-induced atrophic gastritis. Epstein-Barr virus is another infectious cause of GC, and the above two infection-associated GCs are characterized by global CpG island methylation in the promoter region of cancer-related genes. Mutations of tumor protein p53 (TP53) and β-catenin (CTNNB1) genes occur early in the development of GC and contribute to gastric carcinogenesis. Furthermore, significant numbers of GCs show loss of Runx3 due to hemizygous deletion and hypermethylation of the promoter region. Aberrant Cdx2 expression has been shown in precancerous lesions as well as GC. However, it remains unclear whether Cdx2 plays an oncogenic role in gastric carcinogenesis. GC with microsatellite instability is also a well-defined subset exhibiting distinctive clinicopathologic features. Targeted therapy against GC with ERBB2 amplification recently improved the prognosis of patients with advanced GC. In addition, epigenetic changes in GC could be attractive targets for cancer treatment with modulators. A genome-wide search has been undertaken to identify novel methylation-silenced genes in GC, which will help us understand the overall molecular features of GC and further provide novel opportunities in the treatment of GC.
Robot-Assisted Surgery for Gastric Cancer: Experience at Our Institute
Authors: Isogaki Jun , Haruta Shusuke , Man-i Mariko , Suda Koichi , Kawamura Yuichiro , Yoshimura Fumihiro , Kawabata Toshiki , Inaba Kazuki , Ishikawa Ken , Ishida Yoshinori , Taniguchi Keizo , Sato Seiji , Kanaya Seiichiro , Uyama Ichiro
Published: November 2011

Objective: The robot-assisted surgical system was developed for minimally invasive surgery and is thought to have the potential to overcome the shortcomings of laparoscopic surgery. We introduced this system for the treatment of gastric cancer in 2008. Here we report our initial experiences of robot-assisted surgery using the da Vinci system. Methods: A retrospective review of robot-assisted gastrectomy for gastric cancer patients was performed in our institute. The clinicopathological features and surgical outcomes were analyzed. Whereas the procedures of the gastrectomy were similar to those of the usual laparoscopic surgery, several aspects such as the port placement and the role of the assistant were modified from those for conventional laparoscopic surgery. Results: From January 2008 to December 2010, 61 patients with gastric cancer underwent robot-assisted surgery. Gastrectomy was distal in 46 patients, total in 14, proximal in 1 and no operation was converted to the open procedure. D2 lymph node dissection was performed on 28 patients in the distal gastrectomy group and on 11 in the total gastrectomy group. Complications occurred in 2 cases (4%): these consisted of ruptured sutures and hemorrhage from the anastomotic site. Conclusions: This study demonstrated that robot-assisted gastrectomy using the da Vinci system can be applied safely and effectively for patients with gastric cancer.
Cerebral Microbleeds: Histopathological Correlation of Neuroimaging
Authors: Shoamanesh A. , Kwok C.S. , Benavente O.
Published: November 2011

Background: In recent years, there has been a growing interest in cerebral microbleeds (CMBs) and their role in cerebrovascular disease. A few studies have investigated the histopathological correlation between CMBs and neuroimaging findings. We conducted a systematic review in an attempt to characterize the pathological and radiological correlation. Methods: A systematic literature search was conducted for studies in which CMBs were characterized histopathologically and correlated with MRI findings. Results: Five studies met the inclusion criteria, with a total of 18 patients. Hemosiderin deposition was reported in 42 CMBs (49%), while 16 CMBs (19%) were described as old hematomas which stained for iron, 13 (15%) had no associated specific pathology, 11 (13%) contained intact erythrocytes, 1 (1%) was due to vascular pseudocalcification, 1 (1%) was a microaneurysm and 1 (1%) was a distended dissected vessel. Lipofibrohyalinosis was the most prominent associated vascular finding. Amyloid angiopathy was present primarily in patients with dementia. Conclusions: Although histopathological associations have been observed using MRI in patients with CMBs, the findings have yet to be validated and further research is warranted.
Cognitive Profile of Elderly Patients with Mild Stroke
Authors: Gramstad Arne , Aarsland Dag , Naess Halvor
Published: November 2011

Background: A pattern characterizing cognitive deficits in mild stroke could help in differential diagnosis and rehabilitation planning. Methods: Fifty patients with mild stroke (modified Rankin scale ≤2 at discharge) aged >60 years were given the Mini Mental State Examination (MMSE), the Hopkins Verbal Learning Test-Revised (HVLT-R) and the Stroop test. Results: On HVLT-R, significant impairments were found in learning and recall, but not in delayed recall. The Stroop test revealed significant impairments in reading speed, but not in color-word interference. Using the MMSE, significant deficits were only found in the youngest age group. Conclusion: Elderly patients with mild stroke show deficits in verbal learning/recall and in reading speed, but not in the MMSE, delayed recall or color-word interference. The deficits are consistent with a mild-to-moderate brain dysfunction, with relative sparing of medial brain structures.
Influence of Stroke Localization on Autonomic Activation, Immunodepression, and Post-Stroke Infection
Authors: Harms Hendrik , Reimnitz Peter , Bohner Georg , Werich Tabea , Klingebiel Randolf , Meisel Christian , Meisel Andreas
Published: November 2011

Background and Purpose: Experimental and clinical data suggest that overactivation of the sympathetic nerve system (SNS) is an essential mediator of stroke-induced immunodepression, which in turn increases susceptibility to post-stroke infections. In a post hoc analysis of the PANTHERIS (Preventive Antibacterial Treatment in Acute Stroke) trial, we investigated the impact of distinct lesion patterns on SNS activation, immunodepression, and frequency of post-stroke infections. Methods: Stroke volume, stress hormone levels, and immune function were determined on day 1 after stroke onset. Stroke localization was graded using the Alberta Stroke Programme Early CT score (ASPECTS). In univariate analysis, we investigated the impact of clinical (National Institutes of Health Stroke Scale, NIHSS) and imaging stroke characteristics (lesion volume, lateralization, localization grading) on autonomous nervous system activity (norepinephrine, cortisol), immune competence (monocytic HLA-DR expression), and the frequency of post-stroke infections. In a logistic regression model, we tested for independent factors that might increase susceptibility to post-stroke infections. Results: In a single-factor analysis, large stroke volume, lesions affecting distinct regions of the MCA cortex, and SNS activation (elevated norepinephrine levels) were associated with an impaired immune function (reduced mHLA-DR expression) and a higher susceptibility to post-stroke infections. Multivariate analysis identified increased levels of norepinephrine and infarction of the anterior MCA cortex as independent risk factors of post-stroke infections. Neither stroke severity nor stroke volume was independently associated with post-stroke infections. Conclusions: Apart from sympathetic activation, our data suggest that ischemic lesion in the anterior MCA cortex may be a major determinant of stroke-associated infection. This finding has to be confirmed in larger prospective studies.
Choosing an Appropriate Length of Loop Type Ureteral Stent Using Direct Ureteral Length Measurement
Authors: Kawahara Takashi , Ito Hiroki , Terao Hideyuki , Yoshida Minoru , Ogawa Takehiko , Uemura Hiroji , Kubota Yoshinobu , Matsuzaki Junichi
Published: November 2011

Purpose: The ureteral stent is now a fundamental part of many urological procedures. To decrease ureteral stent-related symptoms, loop type ureteral stent was developed. However the most important factor to decrease urinary symptoms is choosing the optimal length of a ureteral stent. We investigated the relationship between the actual ureteral length and the loop type ureteral stent position. Materials and Methods: A total of 226 loop type polyurethane ureteral stents (156 patients) were inserted with four options for stent length (20, 22, 24 and 26 cm). The ureteral length was measured using a ruled 5-Fr ureteral catheter. The appropriateness of stent position was defined into three groups based on kidney-ureter-bladder films. Results: Nine stents (3.9%) migrated, 171 stents (75.7%) were in the appropriate position and 46 stents (19.5%) were overlong. The rate of migration rate and overlong stents closely correlated with the ureteral length when the proximal end of the stent was in the renal pelvis. Conclusions: It is appropriate to choose a loop type ureteral stent that is the same or 1 cm less than the length of the ureter when the proximal end of the stent will be in the renal pelvis.
Narrow-Band Imaging Flexible Cystoscopy in the Detection of Clinically Unconfirmed Positive Urine Cytology
Authors: Zhu Yi-Ping , Shen Yi-Jun , Ye Ding-Wei , Wang Chao-Fu , Yao Xu-Dong , Zhang Shi-Lin , Dai Bo , Zhang Hai-Liang , Shi Guo-Hai
Published: November 2011

Introduction: The objective of this study was to investigate the value of narrow-band imaging (NBI) cystoscopy in the detection of patients with positive voided urine cytology (VUC) who have no evidence of disease after standard initial investigations. Patients and Methods: Between February 2009 and December 2010, 12 patients with positive or suspicious VUC but no regular endoscopic evidence of cancer were investigated with NBI flexible cystoscopy. All the specimens were biopsied both under NBI and white light imaging (WLI). Random biopsies of bladder and prostatic urethra were performed in cases without suspect lesions. Results: Fourteen NBI cystoscopies were carried out in 12 patients. Non-muscle-invasive bladder cancer was diagnosed in 5 of 12 (42%) patients on the first NBI. One patient had carcinoma in situ diagnosed on repeat NBI 3 months later. The sensitivity and specificity in diagnosing unconfirmed positive VUC was 78 and 91% for NBI vs. 50 and 80% for WLI. Conclusions: NBI cystoscopy significantly improves detection of unconfirmed positive VUC over WLI. It should be carried out early in the investigation of such patients before random biopsies and ureteroscopy.
The Role of Vascular Endothelial Growth Factors and Fibroblast Growth Factors in Angiogenesis during Otitis Media
Authors: Husseman Jacob , Palacios Sean D. , Rivkin Alexander Z. , Oehl Heinz , Ryan Allen F.
Published: November 2011

The middle ear response to otitis media includes transformation and hyperplasia of the mucosal epithelium and subepithelial connective tissue. Significant neovascularization is also noted, which occurs both to support the hypertrophied mucosa and to mediate the increased trafficking of leukocytes. We investigated the role of two known potent angiogenic growth factor families, the fibroblast growth factors (FGFs) and vascular endothelial growth factors (VEGFs), in middle ear mucosal angiogenesis. DNA microarrays were used to evaluate the expression of FGFs and VEGFs, as well as their receptors and unique signaling proteins, in the middle ears of mice undergoing a complete course of acute bacterial otitis media. In addition, a member of each family was introduced to the middle ear submucosal compartment of the normal middle ears of guinea pigs, by a continuous-release osmotic minipump system over 1 week. During the course of bacterial otitis media, a significant regulation of a number of genes important for angiogenesis was identified. Histologic evaluation of middle ear mucosa following micropump infusion of both FGF1 and VEGF-A showed significant angiogenesis at the site of infusion in comparison to control saline infusion. These results support a role for FGFs and VEGFs in the neovascularization of the middle ear mucosa during otitis media, and offer a potential avenue for therapeutic intervention.
Cryptic Introgression of Dasypyrum villosum Parental DNA in Wheat Lines Derived from Intergeneric Hybridization
Authors: Caceres M.E. , Pupilli F. , Ceccarelli M. , Vaccino P. , Sarri V. , De Pace C. , Cionini P.G.
Published: November 2011

Cytogenetic and DNA molecular analyses have been carried out in 3 wheat introgression lines (ILs; CS×V58, CS×V59, and CS×V60) derived from Triticum aestivum cv. ‘Chinese Spring’ (CS) × Dasypyrum villosum(Dv) intergeneric hybridization. All lines, which showed several phenotypic differences compared to CS, had the same chromosome number (2n = 42) and structure as CS, and neither chromosomes nor chromatin from Dv were apparently added to their complement. However, Feulgen/DNA cytophotometry showed that there was more nuclear DNA in the lines than in the parental wheat (by 1.85%, 2.76%, and 1.26% in CS×V58, CS×V59, and CS×V60, respectively). Molecular investigation indicated the presence of Dv DNA in the ILs. AFLP analysis of genomic DNA from the ILs, CS, and Dv detected a total of 120 polymorphic bands, of which 7 (5.8%) were present in some or all the ILs and Dv but were absent in CS. PCR amplification, sequence analysis of amplicons, and Southern blot hybridization confirmed the presence of Dv-specific sequences in each of the ILs. These results indicate cryptic introgression of Dv DNA sequences into the genome of the ILs. Some implications of this finding are discussed.
Effect of the Mi gene on reproduction of Meloidogyne hispanica on tomato genotypes
Authors: Santos Maria Clara Vieira dos , Curtis Rosane H.C. , de O. Abrantes Isabel M. , Maleita Carla M. , Powers Stephen J.
Published: November 2011

The root-knot nematode resistance (Mi) gene was screened in 25 tomato genotypes of Solanum lycopersicum, by amplification of REX-1 and Mi23 markers. Ten heterozygous tomato genotypes (Mimi), nine homozygous (MiMi) at the Mi locus and six lacking the Mi gene for resistance to root-knot nematode were identified using the marker REX-1. The results obtained with Mi23 marker confirmed the Mi gene status of the tomato genotypes, except for genotype Valouro RZ F1 that was homozygous (MiMi) and heterozygous (Mimi) at the Mi locus when using the REX-1 and Mi23 markers, respectively. The pathogenicity of Meloidogyne hispanica on the 25 tomato genotypes was assessed 60 days after inoculation with 5000 eggs on the basis of root gall index (GI) and reproduction factor (Rf). All the tomato genotypes were susceptible (excellent or good hosts), with GI > 4 and Rf > 2, except the genotype Rapit (Mimi), considered as resistant/hypersensitive (poor host). In this genotype, the nematode induced galls (GI = 4) on its roots and a small number of eggs were produced (Pf = 3085 ± 485). Significant differences in reproduction were detected between the Mi allelic conditions and genotypes within Mi allelic conditions. The increasing number of Mi alleles (0, 1 or 2) is associated with decreasing Rf, which suggests a possible dosage effect of the Mi gene. The variability observed in the Rf values for MiMi tomato genotypes may reflect an influence of the genetic background of the plants containing the Mi gene. Ten of the 25 tomato genotypes with Mi gene are commercially available. However, only Rapit can be used to control the three most common Meloidogyne spp. and inhibit the increasing of M. hispanica populations, and may have potential to be included in an integrated pest management programme. However, it is advisable to evaluate the pathogenicity of local populations of this nematode species associated with different environmental factors.