bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hoch effiziente asymmetrische Katalyse durch doppelte Aktivierung von Nucleophil und Elektrophil
Authors: Ma Jun‐An , Cahard Dominique 
Published: September 2004

AbstractDie Entwicklung neuer Hochleistungs‐Katalysatoren für asymmetrische Katalysereaktionen ist für die Organische Chemie von dauerhaftem Interesse. Eine aktuelle Methode bei der stereoselektiven Synthese ist die Verwendung einer Kombination von Lewis‐Säure und Lewis‐Base. Der Synergieeffekt durch die Aktivierung mithilfe von zwei oder mehr reaktiven Zentren führt zu hohen Reaktionsgeschwindigkeiten und zu einer hervorragenden Übertragung der stereochemischen Information. Obwohl durch die unerwünschte Reaktion der Lewis‐Säure mit der Lewis‐Base der Katalysator inaktiviert werden kann, wird das Konzept der doppelten Aktivierung mit großem Aufwand weiterentwickelt. Das Ziel ist die Herstellung biomimetischer Katalysesysteme auf der Grundlage enzymatischer Prozesse mit cokatalytischen Metallionen. Doppelt aktivierende Katalysatorsysteme erweitern die Zahl bereits bekannter Katalysatoren beträchtlich. Die effektivsten dieser Systeme werden in diesem Aufsatz erörtert und die Wirkungsmechanismen diskutiert.
Katalytische Carbonylierungen: kein Bedarf an Kohlenmonoxid
Authors: Morimoto Tsumoru , Kakiuchi Kiyomi 
Published: September 2004

AbstractErste bahnbrechende Erfolge in der metallorganischen Katalyse gelangen mit der Entdeckung der Roelen‐Reaktion 1938 (Hydroformylierung mit Kohlenmonoxid und Wasserstoff) und der Reppe‐Reaktion 1939 (Hydrocarboxylierung mit Kohlenmonoxid und Wasser). Seither haben Carbonylierungen mit Kohlenmonoxid einen festen Platz in der metallorganischen Chemie und der organischen Synthese. Allerdings ist die Verwendung von gasförmigem Kohlenmonoxid problematisch (toxisches Treibhausgas), sodass in neuerer Zeit Strategien zur Verwendung anderer Carbonylierungsreagentien entwickelt wurden. Dieser Kurzaufsatz beschreibt Carbonylierungen, die ohne direkten Einsatz von Kohlenmonoxid durchgeführt werden können.
Der Begriff “Dimensionalität” in der Analytischen Chemie – Grundlagen und Anwendungen
Authors: Danzer Klaus 
Published: September 2004

AbstractDer Begriff Dimensionalität wird in der Analytischen Chemie mit unterschiedlicher Bedeutung verwendet. So sprechen Analytiker von zweidimensionalen Analysenmethoden, z. B. der 2D‐NMR‐Spektroskopie oder der 2D‐Dünnschichtchromatographie, von zweidimensionalen oder dreidimensionalen analytischen Informationen,1 von zweidimensionalen oder dreidimensionalen Bildern in der Oberflächenanalytik sowie von m‐dimensionalen Analysendaten,2 die beispielsweise als Resultat von Mehrkomponentenanalysen erhalten werden. Diese Beispiele belegen, dass der Begriff Dimensionalität gegenwärtig teilweise widersprüchlich verwendet wird. Diese verwirrende Situation trägt nicht zu einem einheitlichen Verständnis des Begriffs Dimensionalität in der Analytischen Chemie bei. Es ist deshalb das Anliegen dieses Dokuments, ein Konzept für die Verwendung des Begriffs Dimensionalität in der Analytischen Chemie vorzustellen.
Prognostic significance of serum osteoprotegerin levels in patients with bladder carcinoma
Authors: Mizutani Yoichi , Matsubara Hiroki , Yamamoto Kosuke , Nan Li Yong , Mikami Kazuya , Okihara Koji , Kawauchi Akihiro , Bonavida Benjamin , Miki Tsuneharu 
Published: September 2004

AbstractBACKGROUNDTumor necrosis factor–related apoptosis‐inducing ligand (TRAIL) plays an important role in the process of lymphocyte‐mediated cytotoxicity against malignant cells. Osteoprotegerin (OPG) is a soluble decoy receptor for TRAIL, and circulating OPG has been implicated in the protection of cells from TRAIL‐mediated apoptosis. Thus, OPG may protect tumor cells from lymphocyte‐mediated cytotoxicity and, as a result, contribute to tumor progression. In the current study, the authors investigated this hypothesis in patients with bladder carcinoma.METHODSSerum OPG levels for 185 patients with bladder carcinoma were determined using an enzyme‐linked immunosorbent assay. These levels then were assessed for potential correlations with various disease characteristics and outcome measures.RESULTSThe mean serum OPG concentration in patients with bladder carcinoma was approximately 3 times greater than the mean concentration in healthy individuals, and among patients with bladder carcinoma, higher tumor stage and grade were found to be associated with increased serum OPG levels. Within the subpopulation of patients with superficial bladder carcinoma, after a follow‐up period of 5 years, those who had low serum OPG levels tended to have a longer postoperative tumor‐free interval compared with those who had high serum OPG levels. Furthermore, among patients with muscle‐invasive bladder carcinoma, the 5‐year disease‐specific survival rate was greater for those who had low serum OPG levels than for those who had high serum OPG levels.CONCLUSIONSTo the authors' knowledge, the current study is the first to demonstrate that serum OPG concentration is correlated with both tumor stage and tumor grade and that elevated serum OPG levels are predictive of early recurrence in patients with bladder carcinoma. These findings suggest that serum OPG concentration may have utility as a prognostic parameter in this setting. Cancer 2004. © 2004 American Cancer Society.
Is routine triple endoscopy for head and neck carcinoma patients necessary in light of a negative chest computed tomography scan?
Authors: Guardiola Emmanuel , Pivot Xavier , Dassonville Olivier , Poissonnet Gilles , Marcy Pierre‐Yves , Otto Josiane , Poudenx Michel , Francois Eric , Bensadoun René‐Jean , Thyss Antoine , Demard François , Schneider Maurice 
Published: September 2004

AbstractBACKGROUNDThe objective of the current study was to analyze the results obtained by triple endoscopy during the initial evaluation of a primary carcinoma of the head and neck.METHODSA total of 487 patients with a squamous cell carcinoma of the head and neck was studied. None of the patients had evidence of metastasis or a second primary tumor on the thoracic computed tomography (CT) scan or chest X‐ray. All patients underwent a triple endoscopy including nasopharyngoscopy, laryngoscopy, pharyngoscopy, bronchoscopy, and esophagoscopy.RESULTSA synchronous primary invasive carcinoma of the lung and esophagus was diagnosed in 5 patients (1%) and 10 patients (2%), respectively. In addition, nine lesions were considered to be a regional extension of the primary tumor to the esophagus, and nine in situ carcinomas were observed. It is interesting to note that a significant correlation was found between the risk of a second synchronous esophageal carcinoma and the initial location of the primary head and neck carcinoma (P = 0.002, chi‐square test). Esophageal carcinoma was observed in 1.3% of the patients with an oropharyngeal tumor, 2% of the patients with a laryngeal tumor, none of the patients with a tumor of the oral cavity, and 9.2% of the patients with a hypopharyngeal tumor.CONCLUSIONSThe role of bronchoscopy and esophagoscopy in the presence of a normal thoracic CT scan has been questioned because of the relatively low incidence of a second esophageal and/or lung primary tumor. Nonetheless, based on the same incidence criterion, it appears reasonable to schedule a routine esophagoscopy for those patients with a squamous cell carcinoma of the hypopharynx. Cancer 2004. © 2004 American Cancer Society.
Electronically steerable parasitic array radiator antenna
Authors: Ohira Takashi , Iigusa Kyouichi 
Published: September 2004

AbstractThe electronically steerable parasitic array radiator antenna consists of one feed radiating element and parasitic radiating elements placed in the near field of the active radiator. A beam is formed due to spatial electromagnetic field coupling among radiating elements. The radiation pattern is electronically controlled by means of the variable capacitance devices (varactors) loading the parasitic elements. Unlike a conventional phased array, only one transmitter and receiver are needed for system configuration. Therefore, adaptive beamforming of low dissipation power and low fabrication cost can be achieved. On the other hand, there is only one output port to observe the signal and the weights can be controlled indirectly via reactors instead of direct control. In addition, due to interelement mutual coupling and the parasitic element being directly connected to the reactive device, the linear adaptive array theory developed to date cannot be applied straightforward. In this paper, the configuration of this antenna, its operating principle and formulation, and its measurement method, control scheme, and applications to signal processing are presented. We describe a mathematical model to simulate the radio frequency behavior of the antenna, the equivalent weight vector used for formulation of the characteristics, the admittance matrix including varactors, the effective element length, the equivalent steering vector method, the method for effectively extending the variable range of the capacitance of the varactor, the reactance circuit to cancel nonlinear distortions, the method for calibration of varactors and radiation pattern by measurement of near field of the radiating element, the learning criteria used to control radiation patterns autonomously in adaptation to the electromagnetic environment, the reactance optimization algorithm, the concept of the reactance domain signal processing and the direction of arrival estimation based on such a process, and diversity reception and spatial correlation. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(10): 25–45, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20081
Improved transient and steady‐state performance of series resonant ZCS high‐frequency inverter‐coupled voltage multiplier converter with dual mode PFM control scheme
Authors: Chu Enhui , Gamage Laknath , Ishitobi Manabu , Hiraki Eiji , Nakaoka Mutsuo 
Published: September 2004

AbstractA variety of switched‐mode high‐voltage DC power supplies using voltage‐fed‐type or current‐fed‐type high‐frequency transformer resonant inverters with MOS gate bipolar power transistors (IGBTs) have been recently developed for medical‐use X‐ray high power generators. In general, the high‐voltage high‐power X‐ray generator using voltage‐fed high‐frequency inverter with a high‐voltage transformer link has to meet some performances such as (i) short rising period in start transient of X‐ray tube voltage, (ii) no overshoot transient response in tube voltage, (iii) minimized voltage ripple in periodic steady‐state under extremely wide load variations and filament heater current fluctuation conditions of the X‐ray tube.This paper presents two lossless inductor snubber‐assisted series resonant zero current soft switching high‐frequency inverters using a diode‐capacitor ladder‐type voltage multiplier called Cockcroft‐Walton circuit, which is effectively implemented for a high DC voltage X‐ray power generator. This DC high‐voltage generator which incorporates a pulse frequency modulated series resonant inverter using IGBT power module packages is based on the operation principle of zero current soft switching commutation scheme under discontinuous resonant current and continuous resonant current transition modes. This series capacitor compensated for transformer resonant power converter with a high‐frequency transformer‐linked voltage boost multiplier can efficiently work a novel selectively changed dual mode PFM control scheme in order to improve the start transient and steady‐state response characteristics and can completely achieve stable zero current soft switching commutation tube filament current dependent on wide load parameter setting values with the aid of two lossless inductor snubbers. It is proved on the basis of simulation and experimental results in which a simple and low cost control implementation based on selectively changed dual‐mode PFM for high‐voltage X‐ray DC‐DC power converter with a voltage multiplier strategy has some specified voltage pattern tracking voltage response performances under rapid rising time and no overshoot in start transient tube voltage as well as the minimized steady‐state voltage ripple in tube voltage. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(4): 60–72, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10345
Determination of direct and quadrature axis inductances of synchronous reluctance motors with allowance for cross saturation
Authors: Yamamoto Shu , Ara Takahiro 
Published: September 2004

AbstractThe d‐axis inductance of reluctance motor is affected by not only the d‐axis current but also the q‐axis current, because of cross magnetic saturation between the direct and quadrature axes. This situation is similar for the q‐axis inductance. The authors propose a method to determine the d‐axis inductance related to the d‐ and q‐axis currents and the q‐axis inductance related to the d‐ and q‐axis currents from a standstill test. This method involves the following four steps. First a rectangular‐wave voltage, alternated between plus and minus, is applied to the two armature winding terminals after breaking the rotor in the d‐axis position. Secondly, the voltage and current between the terminals are measured. Thirdly, the d‐axis inductance related with d‐axis current is calculated from the voltage and current. Finally, the process above is repeated when a DC current flows from the remaining armature terminal to neutral point terminal and the d‐inductance related to the d‐ and q‐axis currents is derived. A similar treatment applies when determining the q‐axis inductance related to the d‐ and q‐axis currents in the q‐axis rotor position. The method is implemented on a 1.1 kW–178 V–6.3 A‐4P–2200 min−1 flux barrier type reluctance motor. Results of load performance on a vector controlled reluctance motor measured by on‐load tests and calculated from the d‐ and q‐axis inductances obtained by the proposed method clearly demonstrate the validity of the proposed method. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(4): 52–59, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10377
Network centric approach to protection, control, and monitoring for power system
Authors: Sekiguchi Katsuhiko , Shirota Yoshihiro , Shimoo Manabu , Sugiura Hideaki , Kagami Toshiro , Nakamura Tadashi 
Published: September 2004

AbstractDue to the explosion in use of the Internet, it is expected that a variety of services will be provided through the communication network in the near future. Protection and control systems using the latest communication and information technology also allow for innovative solution to a wide range of power system problems. This paper describes a network‐centric approach to protection, control, and monitoring systems. When the proposed “Network” devices, server, and browser can communicate with each other, they can share information which can enhance the overall protection and control of the power systems. The paper includes: overview of network devices, key technologies, protection and control applications, issues, and conclusion. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(4): 31–41, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20006
Combined carbon‐dioxide‐capturing high‐performance power generation system using a solid oxide fuel cell operating on pressurized fuel/air
Authors: Inui Yoshitaka , Ishida Taichi , Matsumae Tomohiro 
Published: September 2004

AbstractThe authors recently proposed a high‐performance combined carbon‐dioxide‐capturing power generation system using a solid oxide fuel cell (SOFC) and a closed‐cycle MHD generator, in which pure oxygen is used as the oxidant. This combined system makes the best use of the advantages of combustion with pure oxygen but fails to prevent the efficiency deterioration caused by high power demand for oxygen production. In the present study, the authors modified this previous system and proposed an improved combined carbon‐dioxide‐capturing power generation system using SOFC/MHD characterized by a higher overall thermal efficiency. In this system, pure oxygen is supplied only to the combustor to reduce the power required for the oxygen production, and pressurized air is used as the oxidant gas in the SOFC. The power saving amounts to about 5% of the thermal input, resulting in a very high total thermal efficiency of 67.53% (HHV) or 74.94% (LHV), which is considered to be the highest possible value of the overall thermal efficiency of carbon‐dioxide‐capturing systems. Advantages of the proposed system suggest that it is advisable to continue further research in this direction. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(4): 21–30, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20010
High‐resolution image reconstruction with displacement errors: A framelet approach
Authors: Chan Raymond H. , Riemenschneider Sherman D. , Shen Lixin , Shen Zuowei 
Published: September 2004

AbstractHigh‐resolution image reconstruction arises in many applications, such as remote sensing, surveillance, and medical imaging. The Bose and Boo (1998) model can be viewed as the passage of the high‐resolution image through a blurring kernel built from the tensor product of a univariate low‐pass filter of the form [½ + ϵ, 1, …, 1, ½ − ϵ], where ϵ is the displacement error. When the numberLof low‐resolution sensors is even, tight‐frame symmetric framlet filters were constructed (Chan et al.,2004b) from this low‐pass filter using Ron and Shen's (1997) unitary extension principle. The framelet filters do not depend on ϵ, and hence the resulting algorithm reduces to that of the case where ϵ = 0. Furthermore, the framelet method works for symmetric boundary conditions. This greatly simplifies the algorithm. However, both the design of the tight framelets and extension to symmetric boundary are only for evenLand cannot, be applied to the case whenLis odd. In this article, we design tight framelets and derive a tight‐framelet algorithm with symmetric boundary conditions that work for both odd and evenL. An analysis of the convergence of the algorithms is also given. The details of the implementations of the algorithm are also given. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 91–104, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20012
Single‐frame image super‐resolution using learned wavelet coefficients
Authors: Jiji C. V. , Joshi M. V. , Chaudhuri Subhasis 
Published: September 2004

AbstractWe propose a single‐frame, learning‐based super‐resolution restoration technique by using the wavelet domain to define a constraint on the solution. Wavelet coefficients at finer scales of the unknown high‐resolution image are learned from a set of high‐resolution training images and the learned image in the wavelet domain is used for further regularization while super‐resolving the picture. We use an appropriate smoothness prior with discontinuity preservation in addition to the wavelet‐based constraint to estimate the super‐resolved image. The smoothness term ensures the spatial correlation among the pixels, whereas the learning term chooses the best edges from the training set. Because this amounts to extrapolating the high‐frequency components, the proposed method does not suffer from oversmoothing effects. The results demonstrate the effectiveness of the proposed approach. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 105–112, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20013
Target image enhancement using representative line in MR cholangiography images
Authors: Kobashi Syoji , Kondo Katsuya , Hata Yutaka 
Published: September 2004

AbstractMR cholangiography (MRC) is a commonly used imaging method for diagnosing the pancreatic duct. This article proposes a novel method for enhancing medical images called target image enhancement using representative line (TIER), and its application to MRC images. Our method first finds the representative line (RL) of the pancreatic duct using a fuzzy if‐then rule. TIER presumes the approximate region of the pancreatic duct using the obtained RL, and then emphasizes the intensity in the approximate region. Therefore, our method does not require any segmentation procedures, which often may be hard work. We evaluated the ability to find the RL and to estimate the approximate region of the pancreatic duct by applying the proposed method to computer‐simulated data and MRI phantom data. We also show the image‐enhanced images for normal and abnormal patients. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 122–130, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20015
The use of super‐resolution techniques to reduce slice thickness in functional MRI
Authors: Peeters Ronald R. , Kornprobst Pierre , Nikolova Mila , Sunaert Stefan , Vieville Thierry , Malandain Grégoire , Deriche Rachid , Faugeras Olivier , Ng Michael , Van Hecke Paul 
Published: September 2004

AbstractThe problem of increasing the slice resolution of functional MRI (fMRI) images without a loss in signal‐to‐noise ratio is considered. In standard fMRI experiments, increasing the slice resolution by a certain factor decreases the signal‐to‐noise ratio of the images with the same factor. For this purpose an adapted EPI MRI acquisition protocol is proposed, allowing one to acquire slice‐shifted images from which one can generate interpolated super‐resolution images, with an increased resolution in the slice direction. To solve the problem of correctness and robustness of the created super‐resolution images from these slice‐shifted datasets, the use of discontinuity preserving regularization methods is proposed. Tests on real morphological, synthetic functional, and real functional MR datasets have been performed, by comparing the obtained super‐resolution datasets with high‐resolution reference datasets. In the morphological experiments the image spatial resolution of the different types of images are compared. In the synthetic and real fMRI experiments, on the other hand, the quality of the different datasets is studied as function of their resulting activation maps. From the results obtained in this study, we conclude that the proposed super‐resolution techniques can both improve the signal‐to‐noise ratio and augment the detectability of small activated areas in fMRI image sets acquired with thicker slices. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 131–138, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20016
Pseudo‐random properties of self‐complementary symmetric graphs
Authors: Kisielewicz Andrzej , Peisert Wojciech 
Published: September 2004

AbstractThere are some results in the literature showing that Paley graphs behave in many ways like random graphs G(n, 1/2). In this paper, we extend these results to the other family of self‐complementary symmetric graphs. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 310–316, 2004