bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preservation of spleen and brain function in children with sickle cell anemia treated with hydroxyurea
Authors: Hankins Jane S. , Helton Kathleen J. , McCarville M. Beth , Li Chin‐Shang , Wang Winfred C. , Ware Russell E. 
Published: June 2007

AbstractIntroductionChronic organ damage is an insidious process in patients with sickle cell anemia (SCA). Although hydroxyurea prevents acute vaso‐occlusive events, its effects on the preservation of organ function remain undefined.Patients and MethodsWe retrospectively reviewed our single institution experience with children with SCA treated with hydroxyurea for clinical disease severity, who had optional radionuclide liver‐spleen (LS) and brain magnetic resonance imaging (MRI)/with angiography (MRA) performed before and during therapy. Studies were reviewed by pediatric radiologists blinded to treatment status. Demographic and laboratory predictors were modeled using logistic regression.ResultsA total of 43 children had spleen function measured both at baseline and on therapy. After a median of 2.6 years (range, 0.2–8.6 years) of hydroxyurea at maximum tolerated dose (MTD), six patients (14%) completely recovered splenic function and two (5%) had preserved splenic function. These eight children had a greater hemoglobin (Hb) concentration on hydroxyurea therapy than those without splenic function (9.1 vs. 8.6 gm/dl, P = 0.01). Of 25 children with brain MRI/MRA studies performed before initiating hydroxyurea and on therapy, 24 (96%) had no change in brain ischemic lesions compared with pre‐treatment studies, after a median of 2.9 years of treatment.ConclusionThese retrospective data suggest that hydroxyurea at MTD possibly preserves spleen and brain function in children with SCA, and can even result in recovery of splenic function. Higher final Hb concentration during therapy is a significant laboratory predictor of improved splenic function. Pediatr Blood Cancer 2008;50:293–297. © 2007 Wiley‐Liss, Inc.
The European sertindole safety and exposure survey: a follow‐up study of 8600 patients
Authors: Peuskens Joseph , Moore Nicholas , Azorin Jean‐Michel , Toumi Mondher , Cochran John 
Published: June 2007

AbstractBackgroundA regulatory signal suggested that sertindole was associated with a 10‐fold increased risk of death. This observational study aimed to identify deaths and their causes in patients treated with sertindole.MethodsSertindole‐treated patients in Germany, Austria, Belgium, Hungary, The Netherlands and the United Kingdom were identified and their vital status ascertained. Eventual cause of death and patient and treatment characteristics were ascertained. A nested case‐control study compared on‐treatment cardiac or unexplained deaths with randomly selected survivors matched on age and gender for potential risk factors.ResultsEight thousand six hundred eight patients were identified as having initiated treatment with sertindole, for a total 3819 person‐years exposure. Thirty‐five had died since (all‐cause mortality rate 0.92 per 100 person‐years exposed). Of these, 15 (43%) had been previously reported to the regulatory authorities. Eight deaths were suicides, of which 2 (25%) had been previously reported; 11 were cardiac deaths, of which 8 (73%) had been reported.On average, patients who died because of cardiac disorders were older, and patients who committed suicide were younger than the other patients who died. The nested case‐control study revealed that patients receiving sertindole were at a higher risk of premature cardiac or unexplained death if they had hypertension or other cardiovascular disorders associated with diabetes or metabolic disorder.ConclusionOverall and cardiovascular death rates were similar or lower than those observed in premarketing clinical trials. There was a very high reporting rate of all‐cause and cardiovascular deaths that could have contributed to the regulatory alert. Copyright © 2007 John Wiley & Sons, Ltd.
The impact of pharmaceuticals on the decline of cardiovascular mortality in Germany
Authors: Häussler Bertram , Schiffhorst Guido , Gothe Holger , Hempel Elke 
Published: June 2007

AbstractPurposeThe effect of innovative medicines and surgical interventions on the decline of (cardiovascular) mortality is often called into question. The increase in general economic prosperity is often seen as the main reason for the continuous increase in life expectancy. The purpose of this study is to investigate the extent to which mortality from cardiovascular diseases has been affected by pharmaceuticals and other medical interventions over the last 30 years in Germany.MethodsMain outcome measures were the time series of direct method death rates (DMDR) of cardiovascular and non‐cardiovascular mortalities. To control for socioeconomic and secular trends the difference between both time series was calculated. The impact of interventions on mortality was analysed by developing two linear regression models: The onset model analyses whether the introduction of interventions influences mortality or not. The consumption model estimates the quantitative impact of interventions in two phases.ResultsCardiovascular mortality as a percentage of total mortality fell from 40 to 38% over the study period. All investigated interventions had statistically significant effects on the decline of cardiovascular diseases, which is expressed by the standardised regression coefficient: onset model: preventive behaviour index (PBI) −8.3, angioplasty/CABG −0.6, antithrombotic agents −1.5, diuretics −0.9, beta‐blockers −1.0, calcium channel blockers −0.8 and ACE inhibitors −1.1 (all interventions p < 0.01); consumption model: innovative drugs phase I −7.5 (p = 0.017), innovative drugs phase II −6.9 (p < 0.01), PBI −13.1 (p < 0.01) and angioplasty/CABG −9.9 (p < 0.01).ConclusionsAll innovative drug classes and surgical interventions had a positive effect on the decline of cardiovascular mortality. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of fluorene‐based high performance polymers. I. Poly(arylene thioether)s with excellent solubility and high refractive index
Authors: Seesukphronrarak Surasak , Kawasaki Shinichi , Kobori Kana , Takata Toshikazu 
Published: June 2007

AbstractSeveral poly(arylene thioether)s (PTEs) containing a fluorene moiety were synthesized by the polycondensation of masked dithiols such as 9,9‐bis(4‐(N,N‐dimethyl‐S‐carbamoyl)phenyl)fluorene and various difluoroarenes. All PTEs were obtained in quantitative yields. The PTEs showed good thermal stability: the 10% weight loss temperature was over 480 °C under both nitrogen and air atmosphere by TGA, and glass temperature was within a range of 204–275 °C by DSC. Most PTEs exhibited remarkably high refractive index values in a range of 1.66–1.72 at 589 nm, whereas they had a very low degree of birefringence properties. Furthermore, the PTEs showed high solubility in ordinary organic solvents such as chloroform, N‐methylpyrrolidone, and tetrahydrofuran. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3073–3082, 2007
Preparation of polymers having hole and electron transport units by Friedel–Crafts reaction
Authors: Washizu Takashi , Pei Yuanfu , Ha Jaekook , Vacha Martin , Tani Kuniko , Ogino Kenji , Sato Hisaya 
Published: June 2007

AbstractPolymers having 2,5‐diphenyl‐1,3,4‐oxadiazole (BCO) or anthracene (BCA) as an electron transport unit and N,N′‐diphenyl‐N,N′‐bis(4‐butylphenyl)‐benzidine (BTPD) as a hole transport unit were prepared by condensation polymerization using Friedel–Crafts reaction. It was found that BCO was less reactive than BCA. The low reactivity of the BCO monomer can be explained by the oxygen atom in the oxadiazole unit, which acts as a Lewis base and reduces the activity of the catalyst. The redox behavior measured by cyclic voltammetry showed for both BTPD‐BCO and BTPD‐BCA almost the same oxidation potential. In addition, the BTPD‐BCO also exhibited a reduction peak. Hole and electron drifts mobility of the polymers were measured by the time‐of‐flight method. The hole drift mobility of both BTPD‐BCO and BTPD‐BCA was 7.4 × 10−5 cm2 V−1 s−1. The electron drift mobilities of BTPD‐BCO and BTPD‐BCA were 6.5 × 10−5 cm2 V−1 s−1 and 5.2 × 10−6 cm2 V−1 s−1, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3083–3089, 2007
Kinetics of methyl methacrylate and n‐butyl acrylate copolymerization mediated by 2‐cyanoprop‐2‐yl dithiobenzoate as a RAFT agent
Authors: Gao Jing , Luo Yingwu , Wang Rui , Li Bogeng , Zhu Shiping 
Published: June 2007

AbstractThe RAFT (co)polymerization kinetics of methyl methacrylate (MMA) and n‐butyl acrylate (BA) mediated by 2‐cyanoprop‐2‐yl dithiobenzoate was studied with various RAFT concentrations and monomer compositions. The homopolymerization of MMA gave the highest rate. Increasing the BA fraction fBA dramatically decreased the copolymerization rate. The rate reached the lowest point at fMMA ∼ 0.2. This observation is in sharp contrast to the conventional RAFT‐free copolymerization, where BA homopolymerization gave the highest rate and the copolymerization rate decreased monotonously with increasing fMMA. This peculiar phenomenon can be explained by the RAFT retardation effect. The RAFT copolymerization rate can be described by 〈Rp〉/〈Rp〉0 = (1 + 2(〈kc〉/〈kt〉)〈K〉)[RAFT]0)−0.5, where 〈Rp〉0 is the RAFT‐free copolymerization rate and 〈K〉 is the apparent addition–fragmentation equilibrium coefficient. A theoretical expression of 〈K〉 based on a terminal model of addition and fragmentation reactions was derived and successfully applied to predict the RAFT copolymerization kinetics with the rate parameters obtained from the homopolymerization systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3098–3111, 2007
Renewable chain transfer agents for metallocene polymerizations: The effects of chiral monoterpenes on the polyolefin molecular weight and isotacticity
Authors: Mathers Robert T. , Damodaran Krishnan 
Published: June 2007

AbstractMonoterpenes were used as renewable chain transfer agents and polymerization solvents for metallocene/methylaluminoxane (MAO) catalysis. The polymerization of 1‐hexene, ethylene, and propylene in d‐limonene, hydrogenated d‐limonene and α‐pinene is reported. As detected by 1H NMR analysis of the alkene region, chain transfer to d‐limonene yielded a higher percentage of trisubstituted alkenes. Size exclusion chromatography detected a decrease in molecular weight values resulting from chain transfer to d‐limonene. The [mmmm] pentads for isotactic polypropylene were characterized by 13C NMR and FTIR spectroscopy. Propylene polymerizations with the Et(Ind)2ZrCl2/MAO and Me2Si(Ind)2ZrCl2/MAO catalyst systems in d‐limonene gave [mmmm] pentad values as high as 0.97. For the Et(Ind)2ZrCl2/MAO catalyst system at 0 °C, the mol fraction of [mmmm] pentads increased from 0.86 to 0.94 upon switching the solvent from toluene to d‐limonene. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3150–3165, 2007
Linear and branched fluoroazo‐benzene chromophores with increased compatibility in semifluorinated polymers
Authors: Campbell Victoria E. , Paoprasert Peerasak , Mykietyn Justin D. , In Insik , McGee David J. , Gopalan Padma 
Published: June 2007

AbstractA family of fluorinated azobenzene‐based push‐pull chromophores with one, two, and three trifluorovinyl ether (TFV) groups in linear and branched architecture was synthesized and utilized as active materials in the low optical loss electro‐optic (EO) composites. The fluorinated azobenzene chromophores exhibited increased solubility (30–50 wt %) in semifluorinated polymer host, such as perfluorocyclobutane (PFCB) aromatic ether resin after crosslinking, compared with the commercially available nonfluorinated azobenzene chromophore Disperse Red 1 (1–2 wt %). The impact of this approach on the optical properties on the polymer blends is assessed through optical propagation loss measurements and EO characterization. The resulting fluorinated EO composites showed excellent optical clarity, low birefringence, and low optical loss less than 0.5 dB/cm, while giving EO coefficients of about 3–7 pm/V at 1550 nm. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3166–3177, 2007
Effects of carbon nanotubes on crystallization and melting behavior of poly(L‐lactide) via DSC and TMDSC studies
Authors: Shieh Yeong‐Tarng , Liu Gin‐Lung 
Published: June 2007

AbstractIn this work, multiwalled carbon nanotubes (MWNTs) were surface‐modified and grafted with poly(L‐lactide) to obtain poly(L‐lactide)‐grafted MWNTs (i.e. MWNTs‐g‐PLLA). Films of the PLLA/MWNTs‐g‐PLLA nanocomposites were then prepared by a solution casting method to investigate the effects of the MWNTs‐g‐PLLA on nonisothermal and isothermal melt‐crystallizations of the PLLA matrix using DSC and TMDSC. DSC data found that MWNTs significantly enhanced the nonisothermal melt‐crystallization from the melt and the cold‐crystallization rates of PLLA on the subsequent heating. Temperature‐modulated differential scanning calorimetry (TMDSC) analysis on the quenched PLLA nanocomposites found that, in addition to an exothermic cold‐crystallization peak in the range of 80–120 °C, an exothermic peak in the range of 150–165 °C, attributed to recrystallization, appeared before the main melting peak in the total and nonreversing heat flow curves. The presence of the recrystallization peak signified the ongoing process of crystal perfection and, if any, the formation of secondary crystals during the heating scan. Double melting endotherms appeared for the isothermally melt‐crystallized PLLA samples at 110 °C. TMDSC analysis found that the double lamellar thickness model, other than the melting‐recrystallization model, was responsible for the double melting peaks in PLLA nanocomposites. Polarized optical microscopy images found that the nucleation rate of PLLA was enhanced by MWNTs. TMDSC analysis found that the incorporation of MWNTs caused PLLA to decrease the heat‐capacity increase (namely, ΔCp) and the Cp at glass transition temperature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1870–1881, 2007
Analysis of recombinant human erythropoietin and darbepoietin in spiked plasma
Authors: Singh Ashok K. , Gupta Shveta 
Published: June 2007

AbstractDarbepoietin (DAR) and recombinant human erythropoietin (rhEPO) stimulate erythropoiesis, leading to an increase in red blood cells. Along with their legitimate clinical use, rhEPO and DAR are also misused in racing horses for performance enhancement. To control the illegal use of DAR and rhEPO, it is important to develop analytical methods for the detection and confirmation of these proteins in plasma. Analysis of rhEPO and DAR in plasma is challenging due to the presence of a number of high abundance proteins including albumin that interferes with their extraction. The present study showed that the extraction of rhEPO or DAR from plasma using anti‐EPO–antibody coupled immunoaffinity (IA) extraction yielded low (25–40%) recovery. Albumin‐depletion using antialbumin–antibody coupled IA columns also depleted the target proteins and further reduced their recovery. Pre‐extraction of spiked plasma using hydroxyapatite (HTP)‐ProGel or ConA columns followed by the IA column yielded 65 to 70% recovery. The extracted samples were (i) analyzed directly with or without SDS‐PAGE for intact proteins and (ii) analyzed after trypsin hydrolysis, with or without SDS‐PAGE, for peptide fingerprinting using MALDI‐TOF. Trypsin and enolase were used as internal calibrators for intact protein analysis and a peptide EYEATLEECCAK was used as internal calibrator for fragment analysis. Analysis of extracted sample without SDS‐PAGE yielded, along with the target proteins (rhEPO and DAR), albumin and other related proteins. SDS‐PAGE separated the target proteins with albumin and yielded clean samples. Inclusion of internal calibrators resulted in a linear dose–response relationship for both intact protein and digested fragments and allowed quantification of the target peptides. Thus, extraction of plasma using a combination of ConA and IA extractions yielded approximately 70% recovery of target proteins with a small amount of albumin and other proteins. SDS‐PAGE improved the quality of the MALDI‐TOF results. Minimum detection limits for digested fragments were lower than those for intact proteins.
Estimation of the marginal survival time in the presence of dependent competing risks using inverse probability of censoring weighted (IPCW) methods
Authors: Matsuyama Yutaka , Yamaguchi Takuhiro 
Published: June 2007

AbstractIn medical studies, there is interest in inferring the marginal distribution of a survival time subject to competing risks. The Kyushu Lipid Intervention Study (KLIS) was a clinical study for hypercholesterolemia, where pravastatin treatment was compared with conventional treatment. The primary endpoint was time to events of coronary heart disease (CHD). In this study, however, some subjects died from causes other than CHD or were censored due to loss to follow‐up. Because the treatments were targeted to reduce CHD events, the investigators were interested in the effect of the treatment on CHD events in the absence of causes of death or events other than CHD. In this paper, we present a method for estimating treatment group‐specific marginal survival curves of time‐to‐event data in the presence of dependent competing risks. The proposed method is a straightforward extension of the Inverse Probability of Censoring Weighted (IPCW) method to settings with more than one reason for censoring. The results of our analysis showed that the IPCW marginal incidence for CHD was almost the same as the lower bound for which subjects with competing events were assumed to be censored at the end of all follow‐up. This result provided reassurance that the results in KLIS were robust to competing risks. Copyright © 2007 John Wiley & Sons, Ltd.
The Unsteady Boundary Layer on a Spherical Gas Bubble
Authors: Slavchev S. G. , Simeonov G. 
Published: June 2007

AbstractThe boundary layer on a spherical gas bubble started from rest in a viscous incompressible fluid with unsteady velocity is investigated. The velocity is assumed to depend on the time as a power function. As initial motion of the bubble is studied, the Strouhal number is large. The Strouhal number and the Reynolds number are assumed to be of the same order. The Navier‐Stokes equations expressed in spherical polar co‐ordinates are solved by the method of inner and outer expansions. The stream function is analytically obtained up to the fourth approximation. The solution is uniformly valid in the whole flow field and takes into account the interaction between the boundary layer on the bubble surface and the coming external flow. The drag force experienced by the bubble is calculated. The impulsive and uniformly accelerated motions of of the bubble are considered.
On a Nonholonomic System Serving as a Model of a Four‐Wheeled Vehicle
Authors: Lobas L. G. 
Published: June 2007

AbstractThe nonholonomic system considered in this study consists of absolutey solid bodies. Their configuration is described by eight generalized coordinates, their motion obeys to six equations of nonholonomic constraints. The differential equations have two first integrals. The free, steered and programmed motion was investigated. The effects of the longitudinal distribution of the masses of the system are described, recommendations are given for an effective choise of a design scheme of the vehicle.
On the Construction of Operators and Bounding Functionals for Dual Extremum Principles
Authors: Smith P. 
Published: June 2007

AbstractA method is given for the decomposition of certain boundary‐value problems which contain Laplacian and non‐symmetric operators. For Hamiltonian systems this allows the application of upper and lower bounding functionals of dual extremum principles. The method is illustrated in the context of magnetohydrodynamic duct flow.
Konzentrationsschwankungen und Intermittenz in turbulenten, isothermen Freistrahlen
Authors: Haberda F. 
Published: June 2007

AbstractIn Freistrahlen unterschiedlicher Dichte und verschiedener Reynoldszahl wurden Streulichtmessungen der Wahrscheinlichkeitsdichte der Konzentration durchgeführt. Daraus wurden die Mittel‐ und Schwankungswerte der Konzentration und die dritten und vierten Momente der Wahrscheinlichkeitsdichte abgeleitet. Zusätzlich wurden die Intermittenzfaktoren für den Außenluft‐ und den Kernbereich in Abhängigkeit vom Turbulenzgrad der Konzentration bestimmt.
Dynamics of Initially Stressed Hyperelastic Solids
Authors: Reismann H. , Pawlik P. S. 
Published: June 2007

AbstractThis investigation presents a linear, three‐dimensional theory for the incremental motion of initially stressed, hyperelastic solids. The magnitude of the initial deformation and the form of the strain energy density function are both arbitrary except for the usual restrictions placed on them by the principles of mechanics and thermodynamics. A variational approach, using Hamilton's Principle, is used to derive the equations of motion and the proper natural boundary conditions for the incremental motion. This approach yields a variational principle which, because of its scalar form, can be used to derive the appropriate equations in any particular coordinate system. This variational principle also provides a framework for the systematic development of special, approximate theories, for the incremental motion of rods, beams, plates, shells, etc. The investigation concluded with an application: the theory of the initially stressed beam.
Die Invarianzgruppe des Oszillator‐Kepler‐Problems
Authors: Baumgarte J. 
Published: June 2007

AbstractEs wird eine sechsparametrige Gruppe kanonischer Transformationen konstruiert, welche die Hamiltonfunktion der Kepler‐bewegung — mit der exzentrischen Anomalie als unabhängiger Variablen — invariant lassen. Diese Gruppe ist isomorph zur vierdimensionalen Drehgruppe SO(4) und ist dadurch ausgezeichnet, daß sich die Impulse untereinander transformieren. Der Weg, der zur Konstruktion der Invarianz‐Gruppe SO(4) und ist dadurch ausgezeichnet, daß sich die Impulse untereinander transformieren. Der Weg, der zur Konstruktion der Invarianz‐Gruppe SO(4) führt, liefert auch die für die Dynamik der Kepler‐bewegung wichtige Nicht‐Invarianz‐Algebra so(4,2) mit der Invarianz‐Algebra so(4) als Unteralgebra. Im Falle der ebenen Keplerbewegung sind die Transformationen der Impulse durch die stereografische Projektion der Kugeldrehungen gegeben. Über die Konkretisierung von abstrakten Isomorphismen erhält man die KS‐Transformation, welche die dreidimensionale Keplerbewegung auf die vierdimensionale Oszillatorbewegung abbildet.
Über positive Lösungen von Eigenwertgleichungen mit Anwendungen auf elliptische Gleichungen zweiter Ordnung und auf ein Beulproblem für die Platte
Authors: Miersemann E. 
Published: June 2007

AbstractWir studieren positive Lösungen linearer symmetrischer und auch nichtlinearer Eigenwertgleichungen. Dabei wird das Eigenwertproblem direkt im Kegel der nichtnegativen Funktionen gestellt. Die Lösungen genügen zunächst einer Variationsungleichung. Anschließend wird, unter gewissen Voraussetzungen, mit Hilfe eines Zerlegungssatzes von Moreau gezeigt, daß der erste Eigenwert einfach ist und eine positive Eigenfunktion zum ersten Eigenwert gehört. Die Resultate wenden wir an auf elliptische Gleichungen zweiter Ordnung und auf ein Beulproblem für die dünne elastische Platte.
Quality in Mixed Integer Nonconvex and Nondifferentiable Programming
Authors: Chandra Suresh , Chandramohan M. 
Published: June 2007

AbstractIn this paper we formulate the duals of linear and nonlinear fractional programs and certain nondifferentiable programs in which some variables are integer constrained. We also show that in one of the cases an algorithm can be developed as an immediate consequence of this duality theory.