bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing the Non‐Unity of Rate Ratio under Inverse Sampling
Authors: Tang Man‐Lai , Liao Yi Jie , Ng Hong Keung Tony , Chan Ping Shing 
Published: July 2007

AbstractInverse sampling is considered to be a more appropriate sampling scheme than the usual binomial sampling scheme when subjects arrive sequentially, when the underlying response of interest is acute, and when maximum likelihood estimators of some epidemiologic indices are undefined. In this article, we study various statistics for testing non‐unity rate ratios in case‐control studies under inverse sampling. These include the Wald, unconditional score, likelihood ratio and conditional score statistics. Three methods (the asymptotic, conditional exact, and Mid‐P methods) are adopted for P ‐value calculation. We evaluate the performance of different combinations of test statistics and P ‐value calculation methods in terms of their empirical sizes and powers via Monte Carlo simulation. In general, asymptotic score and conditional score tests are preferable for their actual type I error rates are well controlled around the pre‐chosen nominal level, and their powers are comparatively the largest. The exact version of Wald test is recommended if one wants to control the actual type I error rate at or below the pre‐chosen nominal level. If larger power is expected and fluctuation of sizes around the pre‐chosen nominal level are allowed, then the Mid‐P version of Wald test is a desirable alternative. We illustrate the methodologies with a real example from a heart disease study. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Partial Oxidation of 4‐tert‐Butyltoluene Catalyzed by Homogeneous Cobalt and Cerium Acetate Catalysts in the Br−/H2O2/Acetic Acid System: Insights into Selectivity and Mechanism
Authors: van de Water Leon G. A. , Kaza Arati , Beattie James K. , Masters Anthony F. , Maschmeyer Thomas 
Published: July 2007

AbstractThe partial oxidation of 4‐tert‐butyltoluene to 4‐tert‐butylbenzaldehyde by hydrogen peroxide in glacial acetic acid, catalyzed by bromide ions in combination with cobalt(II) acetate or cerium(III) acetate, has been studied in detail. Based on the observed differences in reaction rates and product distributions for the different catalysts, a reaction mechanism involving two independent pathways is proposed. After the initial formation of a benzylic radical species, either oxidation of this intermediate by the metal catalyst or reaction with bromine generated in situ occurs, depending on which catalyst is used. The first pathway leads to the exclusive formation of 4‐tert‐butylbenzaldehyde, whereas reaction of the radical intermediate with bromine leads to formation of the observed side products 4‐tert‐butylbenzyl bromide and its hydrolysis and solvolysis products 4‐tert‐butylbenzyl alcohol and 4‐tert‐butylbenzyl acetate, respectively. The cobalt(II) catalysts Co(OAc)2 and Co(acac)2 are able to quickly oxidize the radical intermediate, thereby largely preventing the bromination reaction (i.e., side‐product formation) from occurring, and yield the aldehyde product with 75–80 % selectivity. In contrast, the cerium catalyst studied here exhibits an aldehyde selectivity of around 50 % due to the competing bromination reaction. Addition of extra hydrogen peroxide leads to an increased product yield of 72 % (cerium(III) acetate) or 58 % (cobalt(II) acetate). Product inhibition and the presence of increasing amounts of water in the reaction mixture do not play a role in the observed low incremental yields.
Overcoming the Demons of Protecting Groups with Amphoteric Molecules
Authors: Yudin Andrei K. , Hili Ryan 
Published: July 2007

AbstractSynthetic organic chemists have long depended on protecting group manipulations when faced with the challenges of chemoselectivity and functional group incompatibility. Overcoming this dependence will improve the overall efficiency of chemical synthesis. By taking advantage of orthogonally reactive functional groups, amphoteric molecules can afford access not only to more efficient and strategic syntheses but also to the development of novel chemical transformations.
X‐ray Structures and Thermodynamics of the Interaction of PA‐IIL from Pseudomonas aeruginosa with Disaccharide Derivatives
Authors: Marotte Karine , Sabin Charles , Préville Cathy , Moumé‐Pymbock Myriam , Wimmerová Michaela , Mitchell Edward P. , Imberty Anne , Roy René 
Published: July 2007

AbstractPseudomonas aeruginosa is an opportunistic bacterium showing increasing resistance to antibiotics and consequently represents elevated threatening problems in hospital environments, particularly for cystic fibrosis patients. The use of glycomimetics as an anti‐adhesive strategy against microorganisms may complement the use of antibiotics. PA‐IIL lectin (LecB) from P. aeruginosa constitutes an appealing target for antibacterial agents, as it has been proposed to play a key role in binding to airway epithelia and/or to be involved in biofilm formation. The lectin has an unusually high affinity for L‐fucose and related oligosaccharides. In the work presented herein, the disaccharide αFuc1‐4GlcNAc is used as a scaffold toward the synthesis of a series of glycomimetic derivatives. Microcalorimetry and structural studies indicate that several of the derivatives are potent inhibitors of the lectin, with affinity in the same range as the best known natural ligand, Lewis a, and could represent interesting leads for the development of future antibacterial compounds.
The impact of pre‐ and post‐transplantation positron emission tomography using 18‐fluorodeoxyglucose on poor‐prognosis lymphoma patients undergoing autologous stem cell transplantation
Authors: Filmont Jean‐Emmanuel , Gisselbrecht Christian , Cuenca Xavier , Deville Laure , Ertault Marjan , Brice Pauline , De Kerviler Eric , Briere Josette , Larghero Jérome , Moretti Jean‐Luc , Mounier Nicolas 
Published: July 2007

AbstractBACKGROUND.In patients with lymphoma who had a poor prognosis, pretransplantation 18‐fluorodeoxyglucose (FDG)‐positron‐emission tomography (PET) was important for the evaluation of response and outcome. However, little is known about the correlation of FDG‐PET with post‐transplantation PET. The current study was designed to ascertain whether positive pretransplantation PET images are modified by the conditioning regimen.METHODS.Sixty consecutive patients who had achieved remission and underwent consolidation by autologous stem cell transplantation (ASCT) had PET images obtained before ASCT (after 3 or 4 chemotherapy cycles) and 100 days after ASCT. The correlation was explored between the presence of abnormal 18‐FDG uptake (PET positive) or its absence (PET negative) and patient outcomes.RESULTS.Before ASCT, 31 patients achieved complete remission (CR), and 23 patients achieved uncertain CR. Before ASCT, 44 patients (75%) were had negative PET images; and, after ASCT, 48 patients (80%) had negative PET images. One year after ASCT, the estimated event‐free survival (EFS) rate was 80% in patients who had negative pre‐ASCT PET images compared with 43% in patients who had positive pre‐ASCT PET images (P = .0002). The EFS rate was 81% in patients who had negative post‐ASCT PET images compared with 25% in patients who had negative post‐ASCT PET images (P < .0001). In multivariate analysis, only the results for pre‐ and post‐ASCT PET images retained prognostic value, with relative risks of failure estimated at 4.9 and 11.9, respectively.CONCLUSIONS.A positive pre‐ASCT PET image indicated a high risk of ASCT failure, which was increased by a positive post‐ASCT PET image. For patients with lymphoma who have positive pre‐ASCT PET images, more investigations using new treatment approaches will be required. For patients who have negative pre‐ASCT PET images, obtaining post‐ASCT PET images does not seem to be mandatory. Cancer 2007. © 2007 American Cancer Society.
Numerical study of radiation effect on MHD transient mixed‐convection flow over a moving vertical cylinder with constant heat flux
Authors: Elgazery Nasser S. , Hassan M. A. 
Published: July 2007

AbstractIn this paper, a numerical analysis to study thermal radiation effect on magnetohydrodynamic (MHD) unsteady mixed‐convection flow over a moving vertical cylinder with constant heat flux through a porous medium in the presence of transversal uniform magnetic field has been performed. The boundary layer equations are transformed into a linear algebraic system by a Crank–Nicolson type of implicit finite‐difference method. The stability condition of the scheme was studied. Numerical results are presented with various sets of parameters for both air and water. The results show many interesting effects on velocity, temperature and concentration profiles on local as well as average shear stress, rate of heat and mass transfer. Also, the velocity and temperature profiles are compared with the available results in the literature and it is found to be in good agreement. Copyright © 2007 John Wiley &
Sons, Ltd.
Remedies to rotational frame dependence and interpolation failure of US‐QUAD8 element
Authors: Ooi E. T. , Rajendran S. , Yeo J. H. 
Published: July 2007

AbstractIt is known that the recently introduced unsymmetric 8‐node quadrilateral element (US‐QUAD8) is highly tolerant to mesh distortions. The high distortion tolerance of US‐QUAD8 is due to the ability of the element to satisfy all the desirable compatibility and completeness requirements of the test and trial functions. The element uses isoparametric and metric shape functions as the test and trial functions, respectively. Despite its high distortion tolerance, the element has two defects. The use of metric shape functions as trial functions causes the element to exhibit rotational frame dependence as well as interpolation failure under certain conditions. A detailed investigation into both these problems is reported and remedies are proposed. Copyright © 2007 John Wiley & Sons, Ltd.
From Carbon Nanostructures to New Photoluminescence Sources: An Overview of New Perspectives and Emerging Applications of Low‐Pressure PECVD
Authors: Gordillo‐Vázquez F. J. , Herrero V. J. , Tanarro I. 
Published: July 2007

AbstractLow‐pressure, plasma‐enhanced (PE)CVD is a powerful and versatile technique that has been used for thin‐film deposition and surface treatment since the early 1960s. However, it is only recently that it has been used in applications other than the different stages of microelectronic circuit fabrication. Now, PECVD is being used in emerging applications due to new materials and process requirements in a wide variety of areas, such as biomedical applications, solar cells, fuel cell development, fusion research, or the synthesis of silicon nanocrystals showing efficient photoluminescence, useful for future solid‐state light sources. These new scenarios have stimulated further development of novel PECVD diagnostic techniques, together with fundamental experimental and theoretical studies aimed at a better understanding of some of the basic processes underlying the plasma/surface interaction. This paper gives an overview of some new research areas where PECVD is finding promising applications.
Plasma‐Enhanced Atomic Layer Deposition of Palladium on a Polymer Substrate
Authors: Ten Eyck G. A. , Pimanpang S. , Juneja J. S. , Bakhru H. , Lu T.‐M. , Wang G.‐C. 
Published: July 2007

AbstractIn this paper, a method for the plasma‐enhanced (PE) atomic layer deposition (ALD) of palladium on air‐exposed, annealed poly(p‐xylylene) (Parylene‐N, or PPX) is presented. Palladium is successfully deposited on PPX at 80 °C using a remote, inductively coupled, hydrogen/nitrogen plasma with palladium (II) hexafluoroacetylacetonate (PdII(hfac)2) as the precursor. By optimizing the mixture of hydrogen and nitrogen, the polymer surface is modified to introduce active sites allowing the chemisorption of the PdII(hfac)2. In addition, enough free hydrogen atoms are available at the surface for ligand removal and Pd reduction, while at the same time, enough hydrogen atoms are consumed in the plasma to ensure there is no visible degradation of the PPX. X‐ray photoelectron spectroscopy (XPS) measurements of the substrate after hydrogen/nitrogen plasma treatment at 50 W clearly show the presence of nitrogen bound to the substrate surface. XPS measurements of the deposited Pd films indicate good quality for both substrates, suggesting that the substrate temperature was low enough to prevent dissociation of the hfac ligand and adequate scavenging of the hfac ligand by the available atomic hydrogen. The remote hydrogen/nitrogen plasma enables Pd film deposition on polymer surfaces, which do not typically react with the Pd precursor, and are not catalysts for the dissociation of molecular hydrogen.
On the Mechanism of Nitrogenated Carbon Film Deposition by PACVD in the Presence of Nitrogen. A Cryo‐Trapping Assisted Mass Spectrometric Study
Authors: Tabarés F. L. , Tafalla D. , Ferreira J. A. 
Published: July 2007

AbstractThe well‐documented effect of film inhibition/perturbation that nitrogen molecules have in the plasma‐assisted (PA)CVD of a‐C/N:H films in a DC glow discharge reactor under low pressure is investigated. Plasma parameters, gas‐phase composition, and film characteristics are recorded using several diagnostic techniques, including the newly developed cryo‐trapping assisted mass spectrometry (CTAMS). Five gas mixtures are investigated; CH4/H2, CH4/N2/H2, and CH4/Ar/H2 as precursors for the films, at low relative concentration of the hydrocarbon molecule (methane), and H2/N2 and He/N2 as film etchers. There are found to be strong differences in the composition of reaction product between systems in which plasma/surface interactions are dominated by ion‐induced processes (sputtering), and those where chemical reactions with nitrogenated species would behave as scavengers of the film precursor. The implications of these findings for the proposed mechanisms of a‐C/N:H film growth are addressed. The application of the scavenger technique for the inhibition of tritium‐containing carbon co‐deposits in the divertor region of fusion reactors, as an international thermonuclear experimental reactor (ITER) in the carbon‐dominated scenarios, is analyzed in the light of these findings.
Notes on q‐ary expanded Reed‐Solomon codes over GF(qm)
Authors: Sakakibara Katsumi , Tokiwa Kin‐Ichiroh , Kasahara Masao 
Published: July 2007

AbstractError‐correcting techniques are important in digital communications, for example, satellite communications, mobile communications, and digital audio systems. In digital communications, block codes such as Reed‐Solomon (RS) codes (recommended for compact disc (CD) and digital audio tape (DAT)) are used.This paper treats q‐ary expanded RS codes over GF(qm) as two‐dimensional codes over GF(q) and gives a new interpretation to q‐ary codes by utilizing the concept of superimposed concatenated codes. Using this new interpretation a lower bound on the minimum distance of q‐ary expanded RS codes over GF(qm) is derived and a new decoding algorithm is clarified.
Upper bounds for the fg‐chromatic index of graphs
Authors: Nakano Shin‐Ichi , Nishizeki Takao , Saito Nobuji 
Published: July 2007

AbstractThis paper introduces a new edge‐coloring of graphs called “fg‐edge‐coloring.” It is used to color all edges of a graph so that at most f(v) edges of a same color exist among edges incident at each vertex v, and at most g(vw) edges among multiple edges joining each pair of vertices v and w. Various upper bounds are given for the fg‐chromatic index, that is, the minimum number of colors required for fg‐coloring. One of them is a generalization of the upper bounds for the ordinary edge‐coloring by Vizing and Hakimi‐Kariv. the proof is constructive and yields a polynomial time algorithm to determine fg‐coloring using colors no more than the upper bound.
An algorithm to enumerate all rectangular dual graphs
Authors: Tani Katsunori , Shirakawa Isao , Tsukiyama Shuji 
Published: July 2007

AbstractDue to the recent development of VLSI technology, circuits have begun to be made on LSI chips in every field of industry. In the layout design, one of the LSI design processes, the main objective, is to minimize the chip area to increase the efficiency and yield rate of ICs. Thus, it is important to find a good floor plan in the sense of area efficiency.This paper considers the problem of enumerating all rectangular dual graphs which are useful in floor plan design of VLSI using the notion of rectangular dual graph. We present an efficient algorithm which runs in O(|V|2) per one rectangular dual graph to be enumerated for a given maximal planar graph G0, where V is a vertex set of G0.
A generalized sampling theorem
Authors: Ogawa Hidemitsu 
Published: July 2007

AbstractUsing the theory of pseudo‐biorthogonal base and the notion of reproducing kernel, we derive a very broad generalized sampling theorem with real pulse. In addition, it includes the traditional sampling theorem with ideal pulse as its special case. It also includes all the sampling theorems in the cases of bandpass‐type band‐limited signal space for nonuniformly spaced sampling points, for many variables, and for the case in which the notion of frequency is extended from Fourier transform to general integral transform. This generalized sampling theorem is effective also for so‐called undersampling whereby there are too few sampling points compared with the dimension of signal space, and for so‐called oversampling due to too many sampling points. Moreover, it is effective in the case where both occur; that is, in the case where it is undersampling from the standpoint of signal space while it is oversampling in a space of restored signal. For undersampling, the generalized sampling theorem provides the best approximation for each original signal.
An NIC‐improved balanced integrator and its application to filters
Authors: Takagi Shigetaka , Anzai Takashi , Yanagisawa Takeshi 
Published: July 2007

AbstractThe authors have proposed a high‐frequency monolithic integrator in [1]. In the proposed circuit, lateral pnp transistors with less satisfactory high‐frequency response were utilized and they limited the high‐frequency response of the integrator. the response was improved by a passive compensation. However, it is difficult to determine the capacitance for the passive compensation.From such a viewpoint, this paper shows that an integrator with a balanced negative impedance converter can be constructed using only npn transistors. the computer analysis is made for the proposed integrator and the integrator proposed in [1], using SPICE 2G.1. It is shown that a performance better than that of the integrator in [1] is obtained without compensation owing to the elimination of pnp transistors. the proposed integrator was applied to the balanced third‐order low‐pass active RC filter system with a cutoff frequency of 1 MHz and with an automatically tunable function. an experiment was performed indicating the practical usefulness of the proposed integrator as well as the system.
A 2‐D digital filter design technique using separate approximation of phase and magnitude responses by denominator and numerator
Authors: Taguchi Akira , Nakahashi Tomoko , Hamada Nozomu 
Published: July 2007

AbstractThis paper discusses a design of two‐dimensional HR digital filter in the frequency domain, where the magnitude and the phase responses are assigned separately to the denominator and the numerator, respectively, and are designed independently. the design procedure is as follows. Considering only the phase, the all‐pole filter (denominator polynomial) is designed. Then the numerator is designed from the 2‐D mirror‐ image polynomial as a correction for the magnitude. In earlier methods of this kind, a nonlinear problem is encountered in the design of the all‐pole filter in approximating the phase. By contrast, in this paper, the 2‐D group‐delay (phase) approximation is reduced to the 2‐D spectral approximation by using the cepstrum, and the derivation of the parameters is reduced to the solution of the 2‐D normal equation. From the viewpoint of ensuring the stability, an approximation by three‐term separable all‐pole filter is also shown, which makes the stability test easy. an algorithm is shown which solves the ap proximation problem for this case by iteratively solving the linear problem. the proposed design method features smaller computational complexity, since the denominator and the numerator polynomials are derived independently. In addition, the design is made easy since the linear problems are handled throughout the filter design.
Determination of parameters of VHF quartz crystal units equipped with evaporated electrodes using an Fr‐meter fixture
Authors: Watanbe Yasuaki , Oomura Yoshimasa , Lizuka Yukinori 
Published: July 2007

AbstractThe Fr meter method is described as a method of measuring quartz crystal units in Appendix 1 of the Japanese Industrial Stand ard (JIS). When the resonance frequency and equivalent parameters of a quartz crystal unit are measured with the Fr‐meter fixture, an equivalent circuit based on four parameters has usually been employed. However, this equivalent circuit is not accurate for representing the impedance characteristic of the unit over a wide frequency range. to solve this problem, this paper offers an accurate method based on an equivalent circuit having five parameters for measuring the parameters over a wide range (from fs to fp) with the Fr meter fixture. the method is based on an equivalent circuit having five parameters.This paper describes the principle of the method; measurements of VHF‐band quartz crystal units; comparisons of the results with those obtained by using the drop method; and an examination of the repeatability of the method. the results show that the standard deviation of the resonance frequencies is within 2 × 10‐8, and the frequency agrees well with that obtained by the drop method. the characteristics between frequency and impedance of quartz crystal units calculated by using the parameters obtained agree well with those measured. It was confirmed that the proposed method with the Fr‐meter fixture could accurately measure the resonance frequency and the parameters of quartz crystal units.
Method of designing SAW low‐pass filters
Authors: Fushimi Shigeo , Watanabe Takaya 
Published: July 2007

AbstractSince it has been rather difficult to realize a relatively steep cutoff characteristic in a video band with switched‐capacitor filters and active ones, LC filters have been used for this purpose. This paper discusses surface acoustic wave (SAW) filters, and proposes a method of designing SAW low‐pass filters which were thought to be difficult to realize, the method offers an easy realization of low‐pass filters having a small size, excellent temperature characteristic, and linear phase characteristic. the low‐ pass filter is obtained by cutting a pair of electrodes having an equal length and an interval of quarter wavelength at a certain distance from the busbars so that electrically floating electrodes are formed without connecting any busbar. This paper describes the conditions required for coefficients of the FIR filter suitable for forming electrodes of an SAW filter, and the method of designing SAW low‐pass filters. A design example of an SAW filter consisting of unapodized electrode (five taps) and apodized electrodes (141 taps) is given. the electrode configuration of a prototype device using this design is shown together with its frequency characteristic.