bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐quality poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylenevinylene] synthesized by a solid–liquid two‐phase reaction: Characterizations and electroluminescence properties
Authors: Wu Xufeng , Shi Gaoquan , Chen Feng'En , Han Shaohu , Peng Junbiao 
Published: May 2004

AbstractPoly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylenevinylene] (MEH‐PPV) with a molar mass of 26–47 × 104 g mol−1 and a polydispersity of 2.5–3.2 was synthesized by a liquid–solid two‐phase reaction. The liquid phase was tetrahydrofuran (THF) containing 1,4‐bis(chloromethyl)‐2‐methoxy‐5‐(2′‐ethylhexyloxy)benzene as the monomer and a certain amount of tetrabutylammonium bromide as a phase‐transfer catalyst. The solid phase consisted of potassium hydroxide particles with diameters smaller than 0.5 mm. The reaction was carried out at a low temperature of 0 °C and under nitrogen protection. No gelation was observed during the polymerization process, and the polymer was soluble in the usual organic solvents, such as chloroform, toluene, THF, and xylene. A polymer light‐emitting diode was fabricated with MEH‐PPV as an active luminescent layer. The device had an indium tin oxide/poly(3,4‐ethylenedioxylthiophene) (PEDOT)/MEH‐PPV/Ba/Al configuration. It showed a turn‐on voltage of 3.3 V, a luminescence intensity at 6.1 V of 550 cd/m2, a luminescence efficiency of 0.43 cd/A, and a quantum efficiency of 0.57%. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3049–3054, 2004
Effect of raised lung volume technique on subsequent measures of V′maxFRC in infants
Authors: Lum S. , Hulskamp G. , Hoo A.‐F. , Ljungberg H. , Stocks J. 
Published: May 2004

AbstractPartial and “full” forced expiratory maneuvers are both used to assess airway function in infants. Despite the increasing use of the raised volume technique, there is little information regarding the influence of lung inflations as are necessary for the raised volume technique on other measurements of lung function in infants. The aim of this study was to assess whether application of the raised volume technique influences subsequent tidal measurements of maximal expired flow at functional residual capacity (V′maxFRC). Paired measurements of V′maxFRC were obtained in 29 healthy infants (aged 6–65 weeks) before and after raised volume maneuvers, wherein a lung inflation pressure of 3 kPa was used. When compared with measurements prior to raising lung volume, there was a highly significant (P < 0.001) decrease in V′maxFRC by 40 ml · sec−1 when measurements were repeated (95% CI, −59, −20 ml · sec−1), equivalent to a reduction of 20% or −0.6 SD scores in flows. There was no significant change in selected tidal breathing parameters, 95% CI of differences between the two sets of measurements being −1.5, 1.2 bpm for respiratory rate; −0.5, 0.2 ml · kg−1 for weight corrected tidal volume, and −0.04, 0.01 for tidal breathing ratio (tPTEF:tE). In conclusion, although the mechanism remains unclear, raised volume maneuvers may influence subsequent measures of lung function in infants. Further research is needed to clarify the potential mechanisms. In the meantime, the potential impact of the order of lung function tests within any given study protocol should be considered carefully. Pediatr Pulmonol. © 2004 Wiley‐Liss, Inc.
Transient phrenic nerve paralysis associated with status asthmaticus
Authors: Santuz Pierantonio , Piccoli Alessandra , Zaglia Federico , Biban Paolo 
Published: May 2004

AbstractPhrenic nerve paralysis is a condition typically occurring after invasive procedures in the chest and neck. Here we describe a case of transient unilateral diaphragmatic paralysis in a child with status asthmaticus complicated by complete right lung atelectasis. Common causes of this disorder and possible implications for our case are discussed. Pediatr Pulmonol. © 2004 Wiley‐Liss, Inc.
Cyproheptadine is an effective appetite stimulant in cystic fibrosis
Authors: Homnick Douglas N. , Homnick Benjamin D. , Reeves Andrew J. , Marks John H. , Pimentel Ronald S. , Bonnema Sally K. 
Published: May 2004

AbstractChronic pulmonary infection and intestinal malabsorption often lead to malnutrition in children and adults with cystic fibrosis (CF). Appetite stimulants, along with provision of adequate calories, may aid in overcoming nutritional deficits, allowing a better prognosis. We undertook a trial of cyproheptadine hydrochloride (CH) to determine its effectiveness as an appetite stimulant in 18 adults and children with CF. This was a 12‐week, randomized, double‐blind, controlled trial of CH vs. placebo. Eighteen subjects with documented CF (sweat or genetics positive), minimum age of 5 years, and ideal body weight for height <100% were entered, and 16 completed the study. Subjects were seen at baseline and every 4 weeks. Measures included baseline demographics, Shwachman score, anthropometrics (weight, height, body mass index, skin folds, and body composition by bioelectric impedance analysis), spirometry, caloric intake, days of oral (PO) and intravenous (IV) antibiotics, and a symptom and satisfaction survey. Subjects in the CH group showed significant increases in weight (mean 3.45 kg vs. 1.1 kg in the placebo group), height, BMI percentiles, ideal body weight/height, weight for age z‐scores, and fat and fat‐free mass. There were no changes or differences in PO or IV antibiotic use or spirometric changes. No significant side effects except transient mild sedation occurred in the CH group. Patient acceptance was good. In conclusion, CH appears to be an effective appetite stimulant with minimal side effects in children and adults with CF. Pediatr Pulmonol. © 2004 Wiley‐Liss, Inc.
Bilirubin influence on oxidative lung damage and surfactant surface tension properties
Authors: Dani Carlo , Martelli Elena , Tronchin Michele , Buonocore Giuseppe , Longini Mariangela , Di Filippo Alessandro , Giossi Massimo , Rubaltelli Firmino F. 
Published: May 2004

AbstractTo study the hypothesis that hyperbilirubinemia might reduce in vivo oxidative lung damage while also diminishing lung surfactant surface tension properties during acute lung injury, we performed a randomized study in a rabbit model of acute lung injury. Twenty rabbits were randomized to receive bilirubin or saline intravenously. Acute lung injury was induced by lung lavages with saline. Lung tissue oxidation was evaluated by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and protein carbonyls (PC) in bronchial aspirate (BA) samples. Surface surfactant activity was studied in BA samples using a capillary surfactometer. Bilirubin BA concentration increased in bilirubin‐treated rabbits, while it remained undetectable in controls. A similar increase in TH, AOPP, and PC bronchial aspirate concentrations was found in both the study and control groups, while surfactant surface activity was lower in the bilirubin than in the control group. We conclude that during hyperbilirubinemia, bilirubin enters the lung tissue, where it can be detected in BA fluid. Bilirubin is not effective as an antioxidant agent and exerts a detrimental effect on lung surfactant surface tension properties. These findings may have relevance to the management of premature neonates suffering from respiratory distress syndrome and hyperbilirubinemia. Pediatr Pulmonol. © 2004 Wiley‐Liss, Inc.
Serum vitamin D levels in children with cystic fibrosis
Authors: Chavasse R.J. , Francis J. , Balfour‐Lynn I. , Rosenthal M. , Bush A. 
Published: May 2004

AbstractOsteopenia is increasingly recognized in adults with cystic fibrosis (CF), and is potentially related to vitamin D deficiency in both adulthood and childhood. Vitamin D supplements are recommended and prescribed to all pancreatic‐insufficient patients. We aimed to ascertain whether vitamin D deficiency in children with CF was prevalent. 25‐hydroxyvitamin D (25‐OHD) was measured in 290 children attending a specialist pediatric CF clinic for annual assessment. 25‐OHD levels were compared with reference values and to other biochemical markers, lung function, and growth. Levels were also analyzed by pancreatic status and by the presence of CF‐related liver disease. Median 25‐OHD was 65 (range, 9–190) nmol/l. One percent had levels below 15 nmol/l, and 6% had levels less than 25 nmol/l. Levels were lower in adolescents (P < 0.001) and during the “winter” months (P < 0.001). No relationship was found with pancreatic status or liver disease. In conclusion, the majority of children had normal 25‐OHD levels. Interpretation is difficult due to a lack of knowledge of optimal levels of 25‐OHD required for healthy bone accretion. Lower levels in adolescents may be a precursor to low levels in adulthood, and did not seem to be simply related to poor compliance with supplementation. This may reflect normal physiology. Pediatr Pulmonol. © 2004 Wiley‐Liss, Inc.
The (CuGaSe2)1−x (MgSe)x alloy system (0 ≤ x ≤ 0.5): X‐ray diffraction, energy dispersive spectrometry and differential thermal analysis
Authors: Grima Gallardo P. , Muñoz M. , Delgado G. E. , Briceño J. M. , Ruiz J. 
Published: May 2004

AbstractThe (CuGaSe2)1−x(MgSe)x alloy system (0 < x ≤ 0.5) was investigated using X‐ray powder diffraction, energy dispersion spectrometry and differential thermal analysis. The solubility of MgSe in CuGaSe2 was found to be nearly complete for all the compositions studied, although traces of MgSe appear as a secondary phase at x ≥ 0.15. All the alloys showed the chalcopyrite structure and the lattice parameters of the unit cell do not follow a linear behavior but showed a soft local maximum at x ∼ 0.15. In the single‐phase field, the increasing behavior of the lattice parameters can be reproduced using an extension for quaternary alloys of Jaffe and Zunger's model for chalcopyrites. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intersubband optical absorption in parabolic quantum wires under a tilted magnetic field
Authors: Ibragimov G. B. 
Published: May 2004

AbstractWe have analyzed the intersubband absorption process in parabolic quantum wires in the presence of a tilted magnetic field. We show that for an increasing magnetic field, the intersubband absorption peak is shifted higher in energy and the peak amplitude is increased. In particular, it is shown that the direction of the magnetic field plays a significant role in the intersubband optical absorption. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and characterization of (CuInSe2)1−x(CoSe)x alloys in the composition range 0 ≤ x ≤ 2/3
Authors: Grima‐Gallardo P. , Muñoz M. , Ruiz J. , Power C. , González J. , LeGodec Y. , Munsch P. , Itié J. P. , Briceño V. , Briceño J. M. 
Published: May 2004

AbstractPolycrystalline samples of (CuInSe2)1−x(CoSe)x alloys were prepared by the normal melt and anneal technique in the composition range 0 < x ≤ 2/3. The obtained ingots were characterized by scanning electron microscopy, X‐ray diffraction and differential thermal analysis techniques. A sample with x = 2/3 (prepared a posteriori) was also studied by the Raman shift technique. The results showed a complex behavior of the phase diagram. The phase (α) with chalcopyrite structure exists in a narrow interval 0 < x < 0.1 in the composition range; then, for 0.1 < x < 0.25, the ordered α phase gradually transforms into a disordered (α′) phase where the cation sites are multi‐occupied (Cu, Co and In) at random. For 0.25 < x < 0.35, two phases were observed, the α′ phase and another, not identified (γ) phase. Finally, for 0.35 < x < 2/3, another chalcopyrite‐like phase (α″) was observed together with traces of the γ phase. The sequence of phase transformations in the studied composition range seems to be α → α′ → α′ + γ → α″ + γ. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between the magnetic phase transition and the electric properties in substituted spinels Zn1−xCuxCr2Se4
Authors: Tokiwa N. , Hidaka M. 
Published: May 2004

AbstractThe electric properties of normal‐type spinels Zn1−xCuxCr2Se4 have been studied by measuring the electric resistivity from 5 K to 300 K. It is found that the substituted compounds with x = 0.02 and 0.15 are semiconductors down to 5 K, while ones with x ≥ 0.30 are metals with high conductivity. However, it is also found that the metallic properties of the latter are characterized by new electric modulations in a low‐temperature region. Zn1−xCuxCr2Se4 with x = 0.3 and 0.5 show the electric phase transition from semiconductor to metal at about 60 K and 25 K, respectively. The metallic compounds with x = 0.75 and 1.0 show the kink of the resistivity at about 60 K with increasing temperature. The highly conductive Zn0.4Cu0.6Cr2Se4 slightly shows the weak semiconducting behavior in the region from 5 K to 280 K. It is considered for the substituted system Zn1−xCuxCr2Se4 with x < 0.75 that, only in the semiconducting phase (0.0 < x < 0.75) and the insulating phase (x = 0.0), there are partially localized Cr3+ spins showing the superexchange interaction between the Cr3+ and Cr3+ spins in the antiferromagnetic phase below about 22 K to 28 K. The antiferromagnetic to ferromagnetic phase transitions occurring at 24 K to 28 K in Zn1−xCuxCr2Se4 with 0.15 ≤ x < 0.75 are induced by the disappearance of the superexchange interaction between localized Cr3+ and Cr3+ spins, and by the predominance of the double‐exchange interaction between Cr3+ spin and conductive Cr4+ spin polaron in the Se2− valence band. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exact solutions for the position‐dependent effective mass Schrödinger equation using the analogy with a PT‐symmetric invariant anharmonic potential
Authors: Moayedi S. K. , Solimannejad M. , Jalbout Abraham F. 
Published: May 2004

AbstractThe aim of the present study is to obtain exact solutions for the one‐dimensional position‐dependent effective mass Schrödinger equation. After the change of wave function on position‐dependent effective mass Schrödinger equation and comparison between the resulted equation with the PT‐symmetric invariant anharmonic potential, three distinct classes of exact solutions are obtained for the Schrödinger equation. As an illustrative example for a Gaussian form of m(x), energy spectrum, potential energy function and wave function are obtained explicitly. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Trial introduction of a complex potential function for perturbation that causes quantum mechanical transition in a one‐dimensional harmonic oscillator
Authors: Yamada Mitsuru 
Published: May 2004

AbstractSome results of computer simulation of the behavior of a one‐dimensional quantum mechanical oscillator are reported in this article. This harmonic oscillator comprises a particle trapped within a hyperbolic potential V(x) = x2. Further, a perturbation potential function V′(x, t) was superposed upon the hyperbolic potential in order to induce a quantum mechanical transition. This perturbation function V′(x, t) is a function of both of space and time variables, and is set to represent a wave packet that is enveloped by a Gaussian bell‐shaped curve. A wave that probably has an appropriate wave number and angular frequency was inputted into the expression for the wave packet. In the initial phase, while the harmonic oscillator was allowed to oscillate almost freely, the wave packet was allowed to approach the harmonic oscillator. In the middle phase, the wave packet passes through the harmonic oscillator, affecting the shape of the quantum mechanical wave that represents the physical state of the system. In the last phase, when the wave packet left the system of the harmonic oscillator, the system settled onto an energetically stable state. The main objective of the simulation was to simulate the instance of a quantum mechanical transition from one eigenstate to another. After several trials, it was found that the perturbation function consisting of a complex function was, at least superficially, able to cause one desired transition, that is, a transition from one eigenstate to another eigenstate. By using such a complex perturbation function, a transition from the first excited state to the ground state was observed to occur. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Climate change, land use change and runoff prediction in the Rhine–Meuse basins
Authors: Pfister Laurent , Kwadijk Jaap , Musy André , Bronstert Axel , Hoffmann Lucien 
Published: May 2004

AbstractAs a consequence of increasing winter rainfall totals and intensities over the second half of the 20th century, signs of increased flooding probability in many areas of the Rhine and Meuse basins have been documented. These changes affecting rainfall characteristics are most evidently due to an increase in westerly atmospheric circulation types. Land use changes, particularly urbanization, can have significant local effects in small basins (headwaters) with respect to flooding, especially during heavy local rainstorms, but no evidence exists that land use change has had significant effects on peak flows in the rivers Rhine and Meuse.For the 21st century, most global circulation models suggest higher winter rainfall totals. Most hydrological simulations of the Rhine–Meuse river basins suggest an increased flooding probability, with a progressive shift of the Rhine from a ‘rain‐fed/meltwater’ river into a mainly ‘rain‐fed’ river. A very limited effect of changes in land use on the discharge regime seems to exist for the main branches of the Meuse and Rhine rivers. For mesoscale basins, future changes in peak flows depend on the changes in the variability of extreme precipitations in combination with land use changes. Copyright © 2004 John Wiley & Sons, Ltd.
Implementation of flood risk management measures into spatial plans and policies
Authors: Böhm Hans Reiner , Haupter Birgit , Heiland Peter , Dapp Klaus 
Published: May 2004

AbstractFloods and risk in river basins can only effectively be reduced if, in addition to technical measures, spatial planning regulates land use in flood‐prone areas. The development of new settlements and industry has to be kept out of the main risk zones. Furthermore detention areas as well as room for river functions must be safeguarded in a long‐term perspective. To make the requirements of flood risk management applicable for regional planning approaches, the Rhine basin is divided into eight different ‘action areas’, according to the following criteria: (1) prevailing flood danger, (2) geophysical situation and (3) possible effects of retention measures. Groups of required actions are assigned to each action area. By this means the framework for regional flood risk management in the Rhine basin is determined.In this framework the improved application of regulative instruments is recommended. Based on obligatory hazard maps graded for different planning levels, regional and local planning activities have to regulate the land use in flood‐prone and detention areas. A two‐zone concept is recommended. Priority zones shall prevent the rise of vulnerability in high risk zones. Reserve zones deliver restrictions and demands on precautionary measures concerning the constructions. The comparison of different planning systems in countries throughout the Rhine basin shows many similarities but also fundamental differences in the planning instruments and their application. In the framework of an interregional co‐operation structure (‘flood management alliance’) it is recommended that the approaches are harmonized in terms of a common basic methodology. Additionally, financial compensation and burden sharing between downstream and upstream regions have to support the implementation of the strategies into spatial plans and policies. Copyright © 2004 John Wiley & Sons, Ltd.
Perspectives on flood management in the Rhine and Meuse rivers
Authors: Middelkoop Hans , Van Asselt Marjolein B. A. , Van' T Klooster Susan A. , Van Deursen Willem P. A. , Kwadijk Jaap C. J. , Buiteveld Hendrik 
Published: May 2004

AbstractFlood management of the Rhine and Meuse is surrounded by major uncertainties. The central question is then: given the uncertainties, what is the best management strategy? Moreover, flood management cannot be considered independently from other river functions such as nature, agriculture, inland navigation and landscape values. This raises the need for integrated scenarios that consider possible futures in a coherent and consistent way. In the present project a scenario study was carried out in which physical modelling has been combined with socio‐cultural theory. The focus of the study was on flood risk management. Existing climate, land use and socio‐economic scenarios, as well as water management strategies have been structured using the Perspectives method. This resulted in integrated scenarios for water management, each representing a different view of the future, together with the corresponding water management style. These were put in a scenario matrix with combinations of world views and management styles, where these both match and mis‐match. Using a suite of existing modelling tools the implications of each scenario for the water systems were evaluated. Finally, a comparison of different water management styles under different possible futures was made, showing the risk, cost and benefits of different strategies. The scenario analyses demonstrate that–at the scale of the entire Rhine basin–the influence of climate change on extreme floods is much stronger than the influence of land use changes. Flood risk management in the lower river deltas should not fully rely on flood mitigation measures in the upstream basin. It also becomes clear that no flood risk management strategy is superior in all respects and in all circumstances and that safety versus societal costs is really a policy dilemma: win–win situations cannot always be attained. Under changing climate conditions, the present‐day type of management in the lower river reaches runs the risk of becoming an expensive attempt to fully control flood risk problems, while trying to avoid real choices, without actually solving the problems in a long‐term view. Copyright © 2004 John Wiley & Sons, Ltd.
The influence of different amounts of clomiphene citrate on follicle‐stimulating hormone, luteinizing hormone and estradiol levels and on the number and maturation of follicles
Authors: Chryssikopoulos A. , Antoniou A. , Kassanos D. , Vazoura E. 
Published: May 2004

AbstractSixty‐eight anovulatory women were divided into three groups according to the administered doses of clomiphene citrate (CC) (A 250 mg, B 500 mg, C 750 mg). Daily follicle‐stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) measurements were performed. Follicular maturation was monitored by ultrasound. In the high‐CC dose group, a statistically significant FSH rise was noted. As a result, earlier selection of the dominant follicle (DF), faster increase in the DF diameter and increased E2 production was found.
Sonographic detection of an asymptomatic rupture of the uterus due to necrosis during the third trimester
Authors: Osmers R. , Ulbrich R. , Schauer A. , Kuhn W. 
Published: May 2004

AbstractThis is a report on the first sonographic detection of a silent rupture of the uterus in the 33rd week of pregnancy of a 35‐year‐old patient. On the basis of the clear sonographic picture immediate cesarian section was (considered) indicated in spite of lack of clinical symptoms. The intraoperative situs confirmed the sonographic diagnosis of a ruptured uterus related to an old cesarian section, combined with partial necrosis of the lower uterine segment.