bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membranständige Ionenkanäle
Authors: Koert Ulrich 
Published: December 2003

AbstractDie schwedische königliche Akademie der Wissenschaften hat den Nobelpreis des Jahres 2003 in Chemie zu gleichen Teilen an Peter Agre und Roderick MacKinnon vergeben. Sie wurden für ihre Entdeckungen bezüglich der Kanäle in Zellmembranen ausgezeichnet.
Supraleiter‐ und Supraflüssigkeiten
Authors: Huebener Rudolf 
Published: December 2003

AbstractDie Königlich Schwedische Akademie der Wissenschaften vergab in diesem Jahr den Physik‐Nobelpreis zu gleichen Teilen an Aleksej Abrikossow, Witalij Ginsburg und Anthony Leggett für ihre „pionierhaften Beiträge zur Theorie der Supraleiter und Supraflüssigkeiten.”︁
Chemische Kampfstoffe, Vergangenheitsbewältigung und aktuelle Aufgabe, Teil 1
Authors: Hildebrandt Henry 
Published: December 2003

AbstractChemische Kampfstoffe sollten der Vergangenheit angehören [1], doch ihre Entsorgung gestaltet sich schwierig [2], zumal moderne Kampfgase seit dem ersten Weltkrieg häufig benutzt wurden — und leicht herzustellen sind [3].
Lithium‐Ionen‐Akkus
Authors: Borchard‐Tuch Claudia 
Published: December 2003

AbstractBeweglichkeit benötigt Energie. Kein Handy, Laptop oder Walkman kommt ohne leistungsfähige Batterien aus. Der Höhepunkt der Entwicklung zeigt sich derzeit in den Lithium‐Ionen‐Akkus, die pro Zelle bis zu 5 Volt liefern und über 1000 Mal wieder aufladbar sind.
Chemie — Augen — Blicke
Authors: Hirche Christina , Kreysa Gerhard 
Published: December 2003

AbstractVom 18. bis 24. Mai 2003 wurde anlässlich der ACHEMA und des Jahres der Chemie auf dem Frankfurter Messegelände auf etwa einem Kilometer Länge die größte Schülergalerie der Welt mit etwa 1.000 Bildern zum Thema Chemie präsentiert.
Dynamics of Photoinduced Electron‐Transfer Processes in Fullerene‐Based Dyads: Effects of Varying the Donor Strength
Authors: Thomas K. George , Biju V. , Kamat Prashant V. , George M. V. , Guldi Dirk M. 
Published: December 2003

AbstractTwo classes of fullerene‐based donor–bridge–acceptor (D–B–A) systems containing donors of varying oxidation potentials have been synthesized. These systems include fullerenes linked to heteroaromatic donor groups (phenothiazine/phenoxazine) as well as substituted anilines (p‐anisidine/p‐toluidine). In contrast to the model compound, an efficient intramolecular electron transfer is observed from the fullerene singlet excited state in polar solvents. An increase in the rate constant and quantum yield of charge separation (kcs and Φcs) has been observed for both classes of dyads, with decrease in the oxidation potentials of the donor groups. This observation indicates that the rates of the forward electron transfer fall in the normal region of the Marcus curve. The long‐lived charge separation enabled the characterization of electron transfer products, namely, the radical cation of the donor and radical anion of the pyrrolidinofullerene, by using nanosecond transient absorption spectroscopy. The small reorganization energy (λ) of C60 coupled with large negative free energy changes (‐ΔG°) for the back electron transfer places the back electron process in the inverted region of Marcus curve, thereby stabilizing the electron transfer products.
Experimental and Computational Investigations of the Properties of Fluorinated Single‐Walled Carbon Nanotubes
Authors: Bettinger Holger F. 
Published: December 2003

AbstractFluorination of single‐walled carbon nanotubes by reaction with elemental fluorine at elevated temperatures provides fluorinated single‐walled carbon nanotubes (F‐SWNT), which have the highest degree of functionalization (up to F/C=1/2) of any derivatized carbon‐nanotube material reported to date. Also, F‐SWNTs have received more scrutiny than any other functionalized carbon nanotubes. This Minireview covers experimental and computational investigations of F‐SWNTs with a focus on the nature and the strength of the C–F linkage.
Stability of surface waves at magnetized plasma – metal interface
Authors: Akimov Yu. A. , Azarenkov N. A. , Olefir V. P. 
Published: December 2003

AbstractThe stability of high‐frequency potential surface waves at a dense magnetized plasma – metal interface with respect to a low‐frequency plasma density modulation is studied in the point of view of the surface waves control. The discussion is addressed to the situation, when an external steady magnetic field is directed perpendicularly to the interface. The nonlinear interaction process of the high‐frequency surface wave, its satellites and the low‐frequency plasma density perturbation is investigated. It is shown that the low‐frequency plasma density perturbation can be represented as a superposition of forced waves of surface and volume types and can lead to an additional attenuation of the surface waves. This attenuation arises when the surface wave amplitude exceeds the threshold value. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Distributed location estimation method for mobile terminals based on SOM algorithm
Authors: Asakura Shigeru , Umehara Daisuke , Kawai Makoto 
Published: December 2003

AbstractAd hoc networks have excellent capabilities for data transmission in an environment with an incomplete communications infrastructure, and in mobility and portability of terminals. Routing protocols between terminals in an ad hoc network can be broadly divided into location‐aware routing, based on location information on the terminals, and non‐location‐aware routing, which is not based on location information. In the former, routing can be made accurate and easy by effectively utilizing location information. Hitherto, the use of the global positioning system (GPS) has been most often treated as the means of acquiring terminal location information. However, in location estimation by GPS, electromagnetic waves from multiple location estimation satellites must be received, and the method cannot be applied effectively in an environment in which that condition is not satisfied. This paper proposes the following method of location estimation. Fixed access points whose absolute locations are already known are placed in the network. Then, by using self‐organizing maps (SOM), the mutual location information among the terminals is organized, and the location of the home terminal is successively inferred. The feasibility and accuracy of estimation in the proposed method are examined by a computer simulation. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(4): 73–81, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10098
Fast fading compensation schemes for OFDM transmission
Authors: Yoshida Haruhito , Maehara Fumiaki , Sasamori Fumihito , Takahata Fumio 
Published: December 2003

AbstractA decision feedback compensation scheme that successively updates the channel estimate based on the decision values of the channel estimate (CE) symbols inserted in the frame header and the symbols in the data section is an effective fading compensation scheme for orthogonal frequency‐division multiplexing (OFDM). However, when rapid phase fluctuations are produced as the received signal level drops in the frame, errors are propagated in successive symbols, and the accuracy of the fading compensation severely degrades. In this paper, we propose a fading compensation scheme for information symbols that places CE symbols in the last section in addition to those in the header section in one frame, which should lessen the error propagation effect. Specifically, we propose a direction‐controlled unidirectional fading compensation scheme that adaptively controls the compensation direction based on the instantaneous signal‐to‐noise ratio (SNR) estimated from the CE symbols on both ends for each subcarrier and a bidirectional fading compensation scheme that detects drops in the received signal level in a frame and switches the direction of the fading compensation. The results of the performance evaluation showed that the performance was improved by the former scheme in a fast fading environment, and a significant improvement in the transmission performance was possible by applying the latter scheme. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(4): 35–44, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10130
A proposal of geographical routing protocols for location‐aware services
Authors: Yamazaki Kosuke , Sezaki Kaoru 
Published: December 2003

AbstractRapid advances in recent device technologies continue to create ubiquitous computing environments that have wireless devices everywhere in the surroundings. Positioning devices such as the Global Positioning System (GPS) and pseudolite continue to decrease in price and wireless devices containing them can determine the location of the device itself. Given this background, providing services based on the location information of a device group, in other words, location‐aware services, is currently an active topic. The location‐aware services being widely researched today provide guide systems to users. A typical service is Intelligent Transport Systems (ITS). However, these services are not available in an environment where special positioning devices cannot be used, and the user must switch to another service. Existing services have the drawback of architectures that are greatly affected by the user's environment. Thus, in this paper, we propose seamless location‐aware services that will improve on these conventional services. We present the problems of using existing methods as the routing protocol, which is an element technology of these services; propose and evaluate a method better suited to these services; and verify its effects by a computer simulation. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(4): 26–34, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10138
A multichannel media access control protocol for multihop wireless networks with guaranteed functions
Authors: Mizuno Kohei , Katayama Minoru , Nakayama Masayoshi , Suda Hirohito 
Published: December 2003

AbstractIn this paper, we propose a multichannel Medium Access Control (MAC) protocol based on the Point Coordination Function (PCF) stipulated in the IEEE 802.11 standard in order to guarantee the end‐to‐end bandwidth in a multihop wireless network. In the proposed protocol, each wireless terminal is equipped with multiple wireless interfaces and assigns a wireless channel to each wireless interface. Each wireless interface autonomously determines whether to operate in the master mode as the parent terminal, in the slave mode as a child terminal, or in the silent mode as a transmission disabled terminal, and builds a parent‐child relationship with each wireless link. Since this enables the use of the PCF at each wireless link and guarantees the bandwidth, the end‐to‐end bandwidth can be guaranteed in a multihop wireless network. We evaluate the performance of the proposed protocol in computer simulations and demonstrate improved throughput, delay, and packet loss rate compared to the conventional Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. We also demonstrate that the bandwidths for bandwidth‐guaranteed packets are guaranteed even when traffic mixing conventional bandwidth‐guaranteed packets and best‐effort packets are present on the network. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(4): 16–25, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10139
Biodiesel stability under commercial storage conditions over one year
Authors: Bondioli Paolo , Gasparoli Ada , Della Bella Laura , Tagliabue Silvia , Toso Guido 
Published: December 2003

AbstractResults obtained from a long‐term storage study using eleven different biodiesel samples are presented. Samples prepared from several feedstocks using different manufacturing technologies (with or without biodiesel distillation), some containing an antioxidant additive, were stored in 200 l drums. These were periodically monitored during the complete storage period by analysis of fifteen different properties.Several properties do not show any significant change during storage, while others such as viscosity, peroxide value and more dramatically, Rancimat Induction Period demonstrated changes related to the nature of the starting product.A parallel test, carried out in simulated wrong storage conditions (occasional shaking promoting intimate contact between biodiesel and air oxygen) lead to some strong changes in biodiesel composition and can be used as a guide for devising biodiesel production set‐up, storage and distribution chain.
Enzymatic production of fatty acid alkyl esters with a lipase preparation from Candida sp. 99‐125
Authors: Deng Li , Tan Tianwei , Wang Fang , Xu Xuebing 
Published: December 2003

AbstractA lipase preparation developed from Candida sp. 99‐125 was used for fatty acid alkyl ester synthesis by both enzymatic esterification of fatty acids, and transesterification of oils and fats. The lipase preparation was chosen based on screening of lipases from commercial sources as well as those produced in the laboratory. The effects of enzyme dosage, solvent types, water absorbent additions, inhibition of short‐chain alcohols, alcohol and acid types, molar ratio of substrates, and reusability of the lipase preparation in esterification were studied. Degree of esterification between oleic acid and methanol under optimal conditions reached 92%. Purity of the methyl ester after washing with water and distillation was 98%. Half‐life of the lipase preparation was calculated to be approximately 340 h. For transesterification of rapeseed oil with the same lipase preparation, the amount of methanol and mode of methanol addition to the reaction were also conducted. Transesterification of the oil with stepwise methanol addition reached 83% after 36 h reaction time.
13‐Phenyltridec‐9‐enoic and 15‐phenylpentadec‐9‐enoic acids in Arum maculatum seed oil
Authors: Christie William W. 
Published: December 2003

AbstractThe seed oil of Arum maculatum has been found to contain 13‐phenyltridec‐9‐enoic (0.4%) and 15‐phenyl‐pentadec‐9‐enoic (1%) acids, detected by gas chromatographymass spectrometry of the picolinyl ester and related derivatives.
The development and application of novel vegetable oils tailor‐made for specific human dietary needs
Authors: Sakurai Hidetoshi , Pokorný Jan 
Published: December 2003

AbstractConventional edible oils, such as sunflower, safflower, soya bean, rapeseed (canola) oils, were modified to obtain high‐oleic, low‐linoleic or even low‐linolenic oils. The aim was to develop salad, cooking and frying oils, that are very stable against lipid peroxidation. They are also suitable for margarine blends, as additives to cheeses and sausages, or even as feed components. Oils containing higher amounts of medium‐chain length or long‐chain polyunsaturated fish oil fatty acids are suitable as special dietetic oils or as nutraceuticals. High‐stearic oils are designed as trans‐fatty acid‐free substitutes for hydrogenated oils. New tailor‐made (designer) oils are thus a new series of vegetable oils suitable for edible purposes, where conventional oils are not suitable.
Georgetown University Fuel Cell Transit Bus Program
Authors: Romano S. , Larkins J.T. 
Published: December 2003

AbstractGeorgetown University (GU) has been at the forefront in the development of transportation fuel cells for over eighteen years. GU has been involved in the development, demonstration and testing of several fuel cell power plants and vehicles, including three 30‐foot transit buses and two 40‐foot transit buses. All of these vehicles are still operational. GU rolled out a 40‐foot fuel cell powered transit bus May 1998. This electric bus is powered by a 100 kW Phosphoric Acid Fuel Cell (PAFC) manufactured by UTC Fuel Cells, LLC. A second 100 kW Proton Exchange Membrane Fuel Cell (PEMFC) power plant has been fabricated by Ballard Transportation Business Unit and has been integrated into a second 40‐foot transit bus platform. This is the world′s largest PEMFC power plant capable of operating on liquid methanol; it rolled out in December, 2001. The GU program is the only one of its kind that is addressing the commercialization of the easily refueled and longer‐range, liquid‐fueled fuel cell buses. As a hydrogen carrier, methanol greatly exceeds the vehicular weight percent storage targets for hydrogen set by the US Department of Energy (DOE). Coal, an abundant US domestic fuel, can be used to produce methanol. The potential to make domestic coal the feedstock for transportation fuel cannot be ignored. This offers a realistic approach to true energy independence. The GU Fuel Cell Powered Transit Bus Program is supported by a grant from the Federal Transit Administration (FTA).
Fuel Cell Vehicle Simulation – Part 2: Methodology and Structure of a New Fuel Cell Simulation Tool
Authors: Hauer K.H. , Moore R.M. 
Published: December 2003

AbstractThis paper is the second part of a three part series. In Part I existing publicly available models for fuel cell vehicle (FCV) analysis and simulation were analyzed and the strengths and weaknesses of these models were identified. In this paper a fuel cell vehicle simulation program (and the methodology behind it) is introduced that overcomes the shortcomings of the previously benchmarked models. Specifically this new fuel cell model: (i)explicitly recognizes the dynamic interaction between the fuel cell system, drive train and optional additional energy storage via electrical and mechanical feedback; (ii) separates the controls from the physical component models (allowing for rapid prototyping techniques); (iii) is strictly modular and follows the vehicle physics as close as possible. Every block can be assigned to a single piece of hardware or control software in the vehicle). The third paper of this series will describe the modeling of individual fuel cell system components and how they are integrated into the overall vehicle model described in this paper.
A longitudinal study of neuropsychological change in individuals with Parkinson's disease
Authors: Azuma Tamiko , Cruz Robyn F. , Bayles Kathryn A. , Tomoeda Cheryl K. , Montgomery E. B. 
Published: December 2003

AbstractObjectivesNeuropsychological changes in individuals with Parkinson's disease (PD) were studied longitudinally.MethodsSixty‐nine idiopathic PD patients, with Mini‐Mental State Examination (MMSE) scores falling within normal range, and 37 elderly control participants were given neuropsychological tests twice approximately two years apart.ResultsThe PD group performed poorer than the control group on Semantic Fluency, Letter Fluency, Modified Wisconsin Card Sorting Task, and Block Design at test time 1. Two years later, the PD group showed significant decline in Semantic and Letter Fluency. A subset of 12 PD patients declined in mental status by second testing (>4 MMSE points). Cox proportional‐hazards models were used to see if any baseline measures were associated with relative risk of decline in mental status. In the final model, Repetition performance and Age were significantly associated with cognitive decline.ConclusionsConsistent with previous studies, executive function tasks were those most susceptible to disease progression. Copyright © 2003 John Wiley & Sons, Ltd.
Use of psychotropics among home‐dwelling nondemented and demented elderly
Authors: Hartikainen Sirpa , Rahkonen Terhi , Kautiainen Hannu , Sulkava Raimo 
Published: December 2003

AbstractObjectiveTo describe the use of psychotropics in the nondemented and demented elderly.ParticipantsThe home‐dwelling elderly (n=523) among the random sample of 700 subjects from the total population of individuals aged 75 years or more in 1998 and living in the city of Kuopio, Finland.MethodsA trained nurse interviewed the participants about their health and current use of medicines. A geriatrician performed clinical examinations and diagnosed diseases. Dementia and depression were diagnosed according to the DSM‐IV criteria.ResultsThe demented subjects used more medicines of all kinds (p<0.01), and especially more psychotropics than the nondemented (p<0.001). One in four demented subjects, compared to one in ten nondemented ones used at least two psychotropics (p<0.01). The demented subjects used antipsychotics six times more often than the nondemented ones (p<0.001). Among the nondemented subjects, one out of two antipsychotics users was suffering from depression according to DSM‐IV criteria. Three out of four persons who had dementia with Lewy bodies were using psychotropics. Persons with moderate dementia were more commonly using all kinds of psychotropic preparations especially, antipsychotics three times more commonly than persons with mild or severe dementia.ConclusionPsychotropics, especially antipsychotics, are commonly used in the treatment of both nondemented and demented elderly, even without proper indication. Physicians need more training about the appropriate use of psychotropics to minimize their adverse effects. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of two‐photon excitation fluorescence lifetime imaging microscopy for protein localization
Authors: Chen Ye , Periasamy Ammasi 
Published: December 2003

AbstractTwo‐photon excitation fluorescence resonance energy transfer (2P‐FRET) imaging microscopy can provide details of specific protein molecule interactions inside living cells. Fluorophore molecules used for 2P‐FRET imaging have characteristic absorption and emission spectra that introduce spectral cross‐talk (bleed‐through) in the FRET signal that should be removed in the 2P‐FRET images, to establish that FRET has actually occurred and to have a basis for distance estimations. These contaminations in the FRET signal can be corrected using a mathematical algorithm to extract the true FRET signal. Another approach is 2P‐FRET fluorescence lifetime imaging (FLIM). This methodology allows studying the dynamic behavior of protein‐protein interactions in living cells and tissues. 2P‐FRET‐FLIM was used to study the dimerization of the CAATT/enhancer binding protein α (C/EBPα). Results show that the reduction in donor lifetime in the presence of acceptor reveals the dimerization of the protein molecules and also determines more precisely the distance between the donor and acceptor. We describe the development and characterization of the 2P‐FRET‐FLIM imaging system with the Bio‐Rad Radiance2100 confocal/multiphoton microscopy system. Microsc. Res. Tech. 63:72–80, 2004. © 2003 Wiley‐Liss, Inc.