bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Physical Environment on Molecular Electromechanical Switching
Authors: Flood Amar H. , Peters Andrea J. , Vignon Scott A. , Steuerman David W. , Tseng Hsian‐Rong , Kang Seogshin , Heath James R. , Stoddart J. Fraser 
Published: November 2004

AbstractThe influences of different physical environments on the thermodynamics associated with one key step in the switching mechanism for a pair of bistable catenanes and a pair of bistable rotaxanes have been investigated systematically. The two bistable catenanes are comprised of a cyclobis(paraquat‐p‐phenylene) (CBPQT4+) ring, or its diazapyrenium‐containing analogue, that are interlocked with a macrocyclic polyether component that incorporates the strong tetrathiafulvalene (TTF) donor unit and the weaker 1,5‐dioxynaphthalene (DNP) donor unit. The two bistable rotaxanes are comprised of a CBPQT4+ ring, interlocked with a dumbbell component in which one incorporates TTF and DNP units, whereas the other incorporates a monopyrrolotetrathiafulvalene (MPTTF) donor and a DNP unit. Two consecutive cycles of a variable scan rate cyclic voltammogram (10–1500 mV s−1) performed on all of the bistable switches (∼1 mM) in MeCN electrolyte solutions (0.1 M tetrabutylammonium hexafluorophosphate) across a range of temperatures (258–303 K) were recorded in a temperature‐controlled electrochemical cell. The second cycle showed different intensities of the two features that were observed in the first cycle when the cyclic voltammetry was recorded at fast scan rates and low temperatures. The first oxidation peak increases in intensity, concomitant with a decrease in the intensity of the second oxidation peak. This variation changed systematically with scan rate and temperature and has been assigned to the molecular mechanical movements within the catenanes and rotaxanes of the CBPQT4+ ring from the DNP to the TTF unit. The intensities of each peak were assigned to the populations of each co‐conformation, and the scan‐rate variation of each population was analyzed to obtain kinetic and thermodynamic data for the movement of the CBPQT4+ ring. The Gibbs free energy of activation at 298 K for the thermally activated movement was calculated to be 16.2 kcal mol−1 for the rotaxane, and 16.7 and 19.2 kcal mol−1 for the bipyridinium‐ and diazapyrenium‐based bistable catenanes, respectively. These values differ from those obtained for the shuttling and circumrotational motions of degenerate rotaxanes and catenanes, respectively, indicating that the detailed chemical structure influences the rates of movement. In all cases, when the same bistable compounds were characterized in an electrolyte gel, the molecular mechanical motion slowed down significantly, concomitant with an increase in the activation barriers by more than 2 kcal mol−1. Irrespective of the environment—solution, self‐assembled monolayer or solid‐state polymer gel—and of the molecular structure—rotaxane or catenane—a single and generic switching mechanism is observed for all bistable molecules.
New approaches in the treatment of myelofibrosis
Authors: Hennessy Bryan T. , Thomas Deborah A. , Giles Francis J. , Kantarjian Hagop , Verstovsek Srdan 
Published: November 2004

AbstractMyelofibrosis with myeloid metaplasia (MMM) is a chronic clonal neoangiogenesis disorder characterized by bone marrow fibrosis and neoangiogensis with extramedullary hematopoiesis. Identification of prognostic factors associated with MMM have not impacted the treatment of the disease, which continues to be palliative with the exception of allogeneic stem cell transplantation (SCT) for potential long‐term disease‐free survival in selected patients. Additional insights into the pathophysiology of MMM have resulted in the use of novel therapeutic strategies in the treatment of this disease. The rationale for the investigation of these agents in MMM and the status of clinical trials with various modalities such as angiogenesis inhibitors (e.g., thalidomide), tyrosine kinase inhibitors (e.g., imatinib mesylate), farnesyl transferase inhibitors (e.g., R115777), and other agents are reviewed, in addition to the potential roles of autologous and allogeneic SCT. Cancer 2005. © 2004 American Cancer Society.
Recent perspectives in the role of chemotherapy in the management of advanced nasopharyngeal carcinoma
Authors: Ma Brigette B. Y. , Chan Anthony T. C. 
Published: November 2004

AbstractBACKGROUNDRecent advances in the treatment of nasopharyngeal carcinoma (NPC) have transpired into better treatment outcomes for patients with locoregionally advanced NPC, and have broadened the chemotherapeutic options for patients with metastatic disease.METHODSData for this review were identified through searches of articles published in PubMed, MEDLINE, and abstracts from selected conference proceedings up to 2004.RESULTSThe results of two meta‐analyses and at least six randomized trials supported a survival benefit with the use of concurrent chemotherapy (e.g., platinum, tegafur‐uracil [UFT)] and standard fractionated radiotherapy (with or without adjuvant chemotherapy) in the management of patients with locoregionally advanced NPC (nonmetastatic Stage III/IV disease, according to the staging system of the International Union Against Cancer). For those patients with metastatic NPC, platinum‐based doublets using newer agents such as gemcitabine and the taxanes are reported to be better tolerated and can yield response rates comparable to those obtained with older, multidrug regimens.CONCLUSIONSThe current study reviewed the latest literature and pertinent issues concerning the role of chemotherapy in the treatment of patients with metastatic and locoregionally advanced NPC. Cancer 2005. © 2004 American Cancer Society.
Spin‐Coating Preparation of Highly Ordered Photoluminescent Films of Layered PbI2‐Aminoalkyloxysilane Perovskites
Authors: Cheng Zi‐Yong , Shi Bao‐Li , Gao Bao‐Xiang , Pang Mao‐Lin , Wang Shu‐Yun , Han Yan‐Chun , Lin Jun 
Published: November 2004

AbstractBy utilising 3‐aminopropyltrimethoxysilane (APTMOS) cations and PbI2 as the organic and inorganic precursors, respectively, a spin‐coated film of a layered perovskite‐type organic/inorganic derivative of APTMOS‐PbI4 was prepared. The structure of APTMOS‐PbI4 was characterised by X‐ray diffraction (XRD), UV/Vis absorption and infrared red spectroscopy (IR). The film showed green emission from the excitons of the inorganic layers and a weak blue emission related to the small amount of gel of adjacent APTMOS cations. Furthermore, the significant effect of the size of the inorganic framework on the cross‐linking degree of APTMOS molecules is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Coumarinolignans from the Root of Formosan Antidesma pentandrum var. barbatum
Authors: Chen Yu‐Chang , Cheng Ming‐Jen , Lee Shoiw‐Ju , Dixit Ajay Kumar , Ishikawa Tsutomu , Tsai Ian‐Lih , Chen Ih‐Sheng 
Published: November 2004

AbstractFour new coumarinolignans, antidesmanin A (=7‐(1,1‐dimethylallyl)‐2,3‐dihydro‐3‐(4‐hydroxy‐3,5‐dimethoxyphenyl)‐10‐methoxy‐2‐methyl‐6H‐1,4,5‐trioxaphenanthren‐6‐one; 1), antidesmanin B (=3,7‐bis(1,1‐dimethylallyl)‐2,3‐dihydro‐2‐(4‐hydroxy‐3‐methoxyphenyl)‐10‐methoxy‐6H‐1,4,5‐trioxaphenanthren‐6‐one; 2), antidesmanin C (=2,7‐bis‐(1,1‐dimethylallyl)‐2,3‐dihydro‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐10‐methoxy‐6H‐1,4,5‐trioxaphenanthren‐6‐one; 3) and antidesmanin D (=2‐(3,4‐dihydroxyphenyl)‐3,7‐bis(1,1‐dimethylallyl)‐2,3‐dihydroxy‐10‐methoxy‐6H‐1,4,5‐trioxaphenanthren‐6‐one or 3‐(3,4‐dihydroxyphenyl)‐2,7‐bis(1,1‐dimethylallyl)‐2,3‐dihydro‐10‐methoxy‐6H‐1,4,5‐trioxaphenanthren‐6‐one; 4) have been isolated from the root of the Formosan Antidesma pentandrum var. barbatum. The structures of these new compounds were elucidated by spectroscopic data. Compounds 1–3 exhibited marginal cytotoxicity against MCF‐7 (breast) and SF‐268 (CNS) cancer cell lines in vitro.
ent‐Clerodanoids from Isodon scoparius
Authors: Xiang Wei , Li Rong‐Tao , Song Qi‐Shi , Na Zhi , Sun Han‐Dong 
Published: November 2004

AbstractThree new ent‐clerodane diterpenoids, isoscoparin A, B, and C (1–3), were isolated from Isodon scoparius. Their structures were determined by NMR‐spectra analysis. The biogenetic implication of the diterpenes from Isodon genus is discussed.
Developmental regulation and cellular distribution of human cytosolic malate dehydrogenase (MDH1)
Authors: Lo Agnes Shuk‐Yee , Liew Choong‐Tsek , Ngai Sai‐Ming , Tsui Stephen Kwok‐Wing , Fung Kwok‐Pui , Lee Cheuk‐Yu , Waye Mary Miu‐Yee 
Published: November 2004

AbstractHuman cyotsolic malate dehydrogenase (MDH1) is important in transporting NADH equivalents across the mitochondrial membrane, controlling tricarboxylic acid (TCA) cycle pool size and providing contractile function. Cellular localization studies indicate that MDH1 mRNA expression has a strong tissue‐specific distribution, being expressed primarily in cardiac and skeletal muscle and in the brain, at intermediate levels in the spleen, kidney, intestine, liver, and testes and at low levels in lung and bone marrow. The observed MDH1 localizations reflect the role of NADH in the support of a variety of functions in different organs. These functions are primarily related to aerobic energy production for muscle contraction, neuronal signal transmission, absorption/resorption functions, collagen‐supporting functions, phagocytosis of dead cells, and processes related to gas exchange and cell division. During neonatal development, MDH1 is expressed in human embryonic heart as early as the 3rd month and then is over‐expressed from the 5th month until the birth. The expression of MDH1 is maintained in the adult heart but is not present in levels as high as in the fetus. Finally, over‐expression of MDH1 is found in left ventricular cardiac muscle of dilated cardiomyopathy (DCM) patients when contrasted to the diseased non‐DCM and normal heart muscle by in situ hybridization and Western blot. These observations are compatible with the activation of glucose oxidation in relatively hypoxic environments of fetal and hypertrophied myocardium. © 2004 Wiley‐Liss, Inc.
Homeostasis of neuroactive amino acids in cultured cerebellar and neocortical neurons is influenced by environmental cues
Authors: Waagepetersen Helle , Melø Torun , Schousboe Arne , Sonnewald Ursula 
Published: November 2004

AbstractNeuronal function is highly influenced by the extracellular environment. To study the effect of the milieu on neurons from cerebellum and neocortex, cells from these brain areas were cultured under different conditions. Two sets of cultures, one neocortical and one cerebellar neurons, were maintained in media containing [U‐13C]glucose for 8 days at initial concentrations of 12 and 28 mM glucose, respectively. Other sets of cultures (8 days in vitro) maintained in a medium containing initially 12 mM glucose were incubated subsequently for 4 hr either by addition of [U‐13C]glucose to the culture medium (final concentration 3 mM) or by changing to fresh medium containing [U‐13C]glucose (3 mM) but without glutamine and fetal calf serum. 13C Nuclear magnetic resonance (NMR) spectra revealed extensive γ‐aminobutyric acid (GABA) synthesis in both cultured neocortical and cerebellar neurons after maintenance in medium containing [U‐13C]glucose for 8 days, whereas no aspartate labeling was observed in these spectra. Mass spectrometry analysis, however, revealed high labeling intensity of aspartate, which was equal in the two types of neurons. Addition of [U‐13C]glucose (4 hr) on Day 8 in culture led to a similar extent of labeling of GABA in neocortical and in cerebellar cultures, but the cellular content of GABA was considerably higher in the neocortical neurons. The cellular content of alanine was similar regardless of culture type. Comparing the amount of labeling, however, cerebellar neurons exhibited a higher capacity for alanine synthesis. This is compatible with the fact that cerebellar neurons could ameliorate a low alanine content after culturing in low glucose (12 mM) by a 4‐hr incubation in medium containing 3 mM glucose. A low glucose concentration during the culture period and a subsequent medium change were associated with decreases in glutathione and taurine contents. Moreover, glutamate and GABA contents were reduced in cerebellar cultures under either of these conditions. In neocortical neurons, the GABA content was decreased by simultaneous exposure to low glucose and change of medium. These conditions also led to an increase in the aspartate content in both types of cultures, although most pronounced in the neocortical neurons. Further experiments are needed to elucidate these phenomena that underline the impact of extracellular environment on amino acid homeostasis. © 2004 Wiley‐Liss, Inc.
Surgical treatment for gastric carcinoma in the elderly
Authors: Coniglio Arianna , Tiberio Guido Alberto Massimo , Busti Monica , Gaverini Giacomo , Baiocchi Luca , Piardi Tullio , Ronconi Maurizio , Giulini Stefano Maria 
Published: November 2004

AbstractBackground and ObjectivesThe incidence of gastric cancer is increasing in the elderly. The aim of this study is to evaluate the impact of advanced age (≥80 years) on morbidity, mortality and late outcome after curative surgery for gastric cancer.MethodsThe cases of 30 octogenarians (Group A) with gastric cancer who underwent surgical treatment in our Institution from 1990 to 2003 were reviewed and compared to a simultaneous group of 228 younger patients (Group B).ResultsThe rate of resective and curative procedures was not different in the two groups, although the American Society of Anaesthesiologists (ASA) risk was significantly higher in the elderly (P < 0.001) and the lymphatic dissection was less extended in group A. In the two groups, the curability was directly correlated to the cancer stage, but not affected by the ASA risk. The postoperative morbidity and mortality rates were similar in the two groups and were not related to the ASA risk. Considering the mortality for gastric cancer alone, the two groups showed a similar survival rate, only correlated to the cancer stage.ConclusionsIn the elderly, an oncologically correct surgical procedure can safely be prosecuted with satisfactory immediate and late results. J. Surg. Oncol. 2004;88:201–205. © 2004 Wiley‐Liss, Inc.
Haemostatic alterations in colorectal cancer: Perspectives for future treatment
Authors: Lykke Jakob , Nielsen Hans Jørgen 
Published: November 2004

AbstractThe role of the haemostatic system in colorectal cancer (CRC) is reviewed. Correlations between the activation of the haemostatic system and overall survival have been suggested. Experimental studies indicate that the haemostatic system plays a key role in growth, invasion and dissemination of tumour cells, and in tumour related angiogenesis. Additional activation by the surgical trauma and postoperative infections are discussed. Finally, anti‐cancer modalities directed against regulation of the haemostatic system in CRC are considered. J. Surg. Oncol. 2004;88:269–275. © 2004 Wiley‐Liss, Inc.
Green coconut water for intravenous use: Trace and minor element content
Authors: Petroianu Georg A. , Kosanovic Melita , Shehatta Ibrahim Saad , Mahgoub Bahaa , Saleh Ayman , Maleck Wolfgang H. 
Published: November 2004

AbstractGreen coconut water (GCW; liquid endosperm) is sterile and has been used in the past in remote locations and/or during armed conflicts as a short‐term intravenous hydration fluid. It is also conceivable to use GCW for total parenteral nutrition (TPN) under similar circumstances. Patients on TPN need elemental supplementation. Although data on the major elements (calcium, magnesium, potassium, sodium, and phosphorus) found in GCW are abundant, very limited information concerning trace and minor element content in GCW is available. The purpose of this study was to determine trace and minor element content in GCW. Major elements were arbitrarily defined as those with a GCW concentration in the mM range, as opposed to minor ones in the μM range and trace elements in the nM range. The values determined show the great variability typical for samples of plant origin. Under TPN conditions, GCW (1,000 mL/day) would be able to provide adequate supplementation of manganese (12 ± 5 μmol/L) and possibly zinc (6 ± 1 μmol/L) but not chromium (not detected, i.e., less than 9 nM/L) and copper (105 ± 100 nM/L). With respect to elements usually considered nonessential or even toxic, GCW compares favorably with commonly used TPN solutions, most notably for aluminium content (740 ± 360 nM/L) and cadmium (7 ± 4 nM/L). The levels of lead (150 ± 67 nmol/L) and barium (600 ± 300 nmol/L) were similar to those typically found in commercial TPN solutions. Those of strontium (8 ± 4 μmol/L) are higher but unlikely to be harmful. In conclusion, although GCW is not completely equivalent to high‐tech (and high‐cost) TPN solutions with trace element supplements, it still may provide sufficient support of at least some of the trace elements if used as a substitute. The GCW investigated by us is, at least, not toxic. However, our results for several trace elements are much lower than values previously reported in the literature, especially in coconuts from “polluted” areas. GCW from polluted soil might be easily toxic if used intravenously. J. Trace Elem. Exp. Med. 17:273–282, 2004. © 2004 Wiley‐Liss, Inc.
Modellierung mehrfach gestufter, teleskopierbarer, spielbehafteter Maschinenelemente
Authors: Barthels Pierre , Wauer Jörg 
Published: November 2004

AbstractGestufte, spielbehaftete, teleskopartig gegeneinander verschiebbare Maschinenelemente werden durch die Bewegung in der Ebene senkrecht zur Teleskopierrichtung zu Transversalschwingungen angeregt. Diese Schwingungen führen in technischen Anwendungen zu einer Reduzierung der Leistungsfähigkeit und zu Sicherheitsproblemen. Die Entwicklung von Maßnahmen zur Schwingungsunterdrückung ist deshalb besonders wichtig. Ein erster Schritt dazu ist die Modellbildung und das Studium der entstehenden Schwingungen. Aus Sicht der Mechanik handelt es sich bei der Modellierung um nichtlineare Feldprobleme mit variabler Geometrie der betreffenden Festkörpersysteme. Materielle Begrenzungen einzelner Komponenten verschieben sich beim Teleskopieren entlang der Begrenzungen anderer Bauteile und definieren so komplizierte Rand bzw. Übergangsbedingungen. Das Spiel führt zu nichtlinearen Effekten. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of digital force control in the presence of damping
Authors: Stréli Tamás , Kisfalusi Krisztián , Stéphán Gábor 
Published: November 2004

AbstractIn the plain of the proportional gain and the ratio of the natural and sampling frequencies, the stability charts of digital force control are constructed for one degree of freedom mechanical models with large variety of viscous damping parameters. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization of Nonlinear Mechanical Systems under Constraints with the Particle Swarm Method
Authors: Sedlaczek Kai , Eberhard Peter 
Published: November 2004

AbstractIn recent years, stochastic optimization methods have gained increasing attention in parameter optimization of mechanical systems. Most popular techniques are Evolutionary Computation and the Simulating Annealing algorithm, which are applied more frequently to mechanical problems due to the increasing computing resources available now. Since theses methods do not require any gradient information, they are well suited for non‐smooth or discontinuous optimization tasks occurring in nonlinear multibody systems. In addition to these techniques, Kennedy and Eberhart [5] introduced the Particle Swarm Optimization method (PSO) based on the simulation of bird flocking. In this work, the efficiency of an extended PSO algorithm has been compared with an Evolutionary Strategy (ES) [6] and an Adapted Simulated Annealing method (ASA) [4]. In order to solve optimization tasks with both equality and inequality constraints the PSO algorithm has been extended by the Augmented Lagrangian Multiplier Method [2]. The proposed method shows often superior results and is quite simple to implement. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation and experimental validation of the dynamic behavior of an electromechanically actuated multiple‐disk clutch
Authors: Treder Marco , Woernle Christoph 
Published: November 2004

AbstractAutomated multiple‐disk clutches in automotive drivelines are at present hydraulically or electrohydraulically actuated. The electromechanical clutch actuation represents an alternative. The subject of the investigation is a functional model of an electromechanical clutch actuator which consists of a servo motor, a reduction gear and a mechanism for the realization of the force acting on the disks. For the simulation of the dynamic behavior of the electromechanically actuated multiple‐disk clutch a detailed multibody model is developed which includes models of the electromechanical actuator and the wet multiple‐disk clutch. The multiple‐disk clutch is described by coupled partial models for the rotational and translational dynamics. The coupling parameters are the relative disk distances and the forces between the disks. The results of test bench measurements are compared to simulation results. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Inertia on the Microscale in Homogenization
Authors: Alvermann S. , Schanz M. 
Published: November 2004

AbstractWhen calculating effective dynamical properties of a material, inertia on the microscale is usually neglected. Here, contrary to these approaches, inertia effects are taken into account, leading to a frequency dependent microscopic behavior. Thus, a frequency dependent macroscopic constitutive equation is required. Therefore, a viscoelastic constitutive equation is applied on the macroscale. The material parameters are found using an Evolutionary Strategy. In the 1‐D case, system responses on the micro‐ and macroscale show a good agreement in a frequency range from 0 up to the first eigenfrequency of the microstructure. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling the mechanical properties of biaxial weft‐knitted fabric reinforced
Authors: Haasemann Georg , Ulbricht Volker , Brummund Jörg 
Published: November 2004

AbstractThe subjects of the analysis are glass/epoxy‐composites with biaxial weft knitted fabric reinforcement. This fabric combines the advantages of high in‐plane stiffness and delamination resistance provided by the biaxial and knitted fabric, respectively. The asymptotic homogenisation procedure based on the displacement method in conjunction with a finite element model provides the possibility to obtain the effective material stiffness. The effort to generate a pure 3D‐model of the unit cell would be extremely high. A solution of this problem gives the Binary Model where a simplified geometry of the interior structure is used.Additionally, the Voigt and Reuss bounds for the Young's and shear moduli are found by using the 3D orientation averaging procedure. The results obtained with the Binary Model will be compared to these bounds and the experimental results. The work done for this paper is sponsored by the German Research Community (DFG) in the context of the priority program (SPP) no. 1123. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)