bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spin‐echo fMRI in humans using high spatial resolutions and high magnetic fields
Authors: Yacoub Essa , Duong Timothy Q. , Van De Moortele Pierre‐Francois , Lindquist Martin , Adriany Gregor , Kim Seong‐Gi , Uğurbil Kâmil , Hu Xiaoping 
Published: March 2003

AbstractThe Hahn spin‐echo (HSE)‐based BOLD effect at high magnetic fields is expected to provide functional images that originate exclusively from the microvasculature. The blood contribution that dominates HSE BOLD contrast at low magnetic fields (e.g., 1.5 T), and degrades specificity, is highly attenuated at high fields because the apparent T2 of venous blood in an HSE experiment decreases quadratically with increasing magnetic field. In contrast, the HSE BOLD contrast is believed to arise from the microvasculature and increase supralinearly with the magnetic field strength. In this work we report the results of detailed and quantitative evaluations of HSE BOLD signal changes for functional imaging in the human visual cortex at 4 and 7 T. This study used high spatial resolution, afforded by the increased signal‐to‐noise ratio (SNR) of higher field strengths and surface coils, to avoid partial volume effects (PVEs), and demonstrated increased contrast‐to‐noise ratio (CNR) and spatial specificity at the higher field strengths. The HSE BOLD signal changes induced by visual stimulation were predominantly linearly dependent on the echo time (TE). They increased in magnitude almost quadratically in going from 4 to 7 T when the blood contribution was suppressed using Stejskal‐Tanner gradients that suppress signals from the blood due to its inhomogeneous flow and higher diffusion constant relative to tissue. The HSE signal changes at 7 T were modeled accurately using a vascular volume of 1.5%, in agreement with the capillary volume of gray matter. Furthermore, high‐resolution acquisitions indicate that CNR increased with voxel sizes < 1 mm3 due to diminishing white matter or cerebrospinal fluid‐space vs. gray matter PVEs. It was concluded that the high‐field HSE functional MRI (fMRI) signals originated largely from the capillaries, and that the magnitude of the signal changes associated with brain function reached sufficiently high levels at 7 T to make it a useful approach for mapping on the millimeter to submillimeter spatial scale. Magn Reson Med 49:655–664, 2003. © 2003 Wiley‐Liss, Inc.
Unsupervised reconstruction of a three‐dimensional left ventricular strain from parallel tagged cardiac images
Authors: Denney Thomas S. , Gerber Bernhard L. , Yan Litao 
Published: March 2003

AbstractA new algorithm, called the Unsupervised Tag ExTraction and Heart strain(E) Reconstruction (UNTETHER) algorithm, is presented for quantifying three‐dimensional (3D) myocardial strain in tagged cardiac MR images. Five human volunteers and five postinfarct patients were imaged. 3D strains measured by UNTETHER and a user‐supervised technique were compared. Each study was analyzed in 49 ± 8 min with UNTETHER, compared to ∼4 hr with the user‐supervised technique. For pooled human data, the correlation coefficient between the two methods for circumferential shortening (Ecc) was r = 0.91 at the mid‐wall (P < 0.0005). UNTETHER is capable of measuring wall motion abnormalities resulting from coronary artery disease, and has the potential to overcome the main limitations (time and user‐supervision requirements) to routine clinical use of tagged cardiac MRI. Magn Reson Med 49:743–754, 2003. © 2003 Wiley‐Liss, Inc.
Local reconstruction of stenosed sections of artery using multiple MRA acquisitions
Authors: Herment A. , Roullot E. , Bloch I. , Jolivet O. , De Cesare A. , Frouin F. , Bittoun J. , Mousseaux E. 
Published: March 2003

AbstractA method for reconstructing magnetic resonance angiography (MRA) volumes from successive acquisitions is described. The method is based on double oblique acquisitions of highly anisotropic MRA volumes, each of which corresponds to reduced k‐space filling. These partial k‐spaces are then combined to obtain a 3D k‐space adapted to the frequency spread of the angiographic image of the stenosis. The SNR‐resolution compromise of MRA is thus improved by focusing the acquisition on the most relevant k‐space regions. The reconstruction is performed directly in k‐space by averaging the partial k‐spaces. The feasibility of the method was demonstrated in studies on a Lucite stenosis phantom, on MRAs of carotid arteries using three bolus injections, and on MRAs of renal arteries using a single contrast injection. Magn Reson Med 49:731–742, 2003. © 2003 Wiley‐Liss, Inc.
Screening for risk of rehospitalization from home care: Use of the outcomes assessment information set and the probability of readmission instrument
Authors: Bowles Kathryn H. , Cater Jacqueline R. 
Published: March 2003

AbstractThe purpose of this study was to evaluate the Outcomes Assessment Information Set (OASIS) compared with the Probability of Readmission (Pra) instrument for use in predicting rehospitalization during home care. Using logistic regression and receiver operating characteristic (ROC) curve analysis, the Pra instrument was found to be significantly better at predicting rehospitalization than the OASIS case mix weight, clinical, or service scores. The area under the curve (AUC) for the Pra was .686 compared with .549 for the OASIS case mix weight (p = .010). Similar results were found for the OASIS clinical and service scores. The AUC for the function score of ≥2 (.599) provided the closest approximation to the Pra (.686), and the difference between the two was not statistically significant (p = .120). The OASIS function score could be used to identify at‐risk home care patients without having to also use the Pra instrument. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:118–127, 2003
Toward a metasynthesis of qualitative findings on motherhood in HIV‐positive women
Authors: Sandelowski Margarete , Barroso Julie 
Published: March 2003

AbstractA qualitative metasynthesis of qualitative findings ought to be more than a mere summary of those findings. Yet the processes by which the interpretive innovation expected of qualitative metasynthesis projects can be achieved remain opaque. Several analytic devices for the metasynthesis of findings were clarified in the course of an ongoing methodological project involving 45 reports of qualitative studies of HIV‐positive women. These devices include the creation of a taxonomy of findings, the explicit use of sustained comparisons, the translation of in vivo concepts, and the use of imported concepts. Any qualitative metasynthesis of findings constitutes an interpretation at least three times removed from the lives represented in them. Clarifying the analytic devices used to create such metasyntheses is essential to demonstrating that despite being far away from participants' lives, these interpretations remain close to them. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:153–170, 2003
Psychometric characteristics of the breastfeeding self‐efficacy scale: Data from an Australian sample
Authors: Creedy Debra K. , Dennis Cindy‐Lee , Blyth Rosemary , Moyle Wendy , Pratt Jan , De Vries Susan M. 
Published: March 2003

AbstractMany new mothers discontinue breastfeeding prematurely because of difficulties encountered rather than maternal choice. Research has shown that a significant predictor of breastfeeding duration is a mother's confidence in her ability to breastfeed. To measure breastfeeding confidence, the Breastfeeding Self‐Efficacy Scale (BSES) was developed and psychometrically tested at 1 week postpartum. The purpose of this methodological study was to psychometrically test the BSES antenatally and at 1 week and 4 months postpartum in a sample of Australian women and to determine predictive validity. The psychometric assessment of the original BSES study was replicated, including internal consistency, principal components factor analysis, comparison of contrasted groups, and correlations with a similar construct. Support for predictive validity was demonstrated through positive correlations and significant mean differences between antenatal BSES scores and infant‐feeding method at 1 week and 4 months postpartum. The BSES is now considered ready for both research and clinical use (a) to identify new mothers with low breastfeeding confidence who require additional assistance, (b) to assess breastfeeding behaviors and cognitions in order to have individualized confidence‐building strategies, and (c) to assist in the evaluation of various nursing interventions. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:143–152, 2003
Effects of stress management on PNI‐based outcomes in persons with HIV disease
Authors: McCain Nancy L. , Munjas Barbara A. , Munro Cindy L. , Elswick R. K. , Robins Jo L. Wheeler , Ferreira‐Gonzalez Andrea , Baliko Beverly , Kaplowitz Lisa G. , Fisher Evelyn J. , Garrett Carleton T. , Brigle Kevin E. , Kendall Linda C. , Lucas Valentina , Cochran Katherine L. 
Published: March 2003

AbstractA pretest–posttest, repeated‐measures design was used to evaluate the effects of two stress management interventions on a battery of outcomes derived from a psychoneuroimmunological (PNI) framework. The effects of cognitive‐behavioral relaxation training groups (CBSM) and social support groups (SSG) were compared with a WAIT‐listed control group on the outcomes of psychosocial functioning, quality of life, neuroendocrine mediation, and somatic health. Participants were 148 individuals (119 men, 29 women), diagnosed with HIV disease; 112 (76%) completing the study groups. Using analysis of covariance, the CBSM group was found to have significantly higher postintervention emotional well‐being and total quality‐of‐life scores than did either the SSG or WAIT groups. SSG participants had significantly lower social/family well‐being scores immediately postintervention and lower social support scores after 6 months. The findings point to a pressing need for further, well‐controlled research with these common intervention modalities. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:102–117, 2003
Teaching nursing research to undergraduates: A text analysis of instructors' intentions
Authors: Porter Eileen J. , Mansour Tamam B. 
Published: March 2003

AbstractReviews of teaching strategies for undergraduate nursing research have been organized according to (a) the type of learning to be achieved, such as learning by doing, or (b) the specific teaching strategy, such as a poster session. For this text analysis, a new tack was taken to reveal the intentions of undergraduate nursing research instructors for student learning. Giorgi's (1985) descriptive phenomenological method was used to analyze 77 narrative reports of instructors about research teaching strategies. Seven intentions were identified, including desensitizing negative perceptions about research and stimulating collaborative learning about research. The intentions were contrasted in scope and relevance to frameworks organized according to learning goals or teaching techniques. The relevance of the intentions was considered in relation to critical trends influencing nursing education. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:128–142, 2003
Situated clinical reasoning: Distinguishing acute confusion from dementia in hospitalized older adults
Authors: McCarthy Marianne 
Published: March 2003

AbstractIn this study a dimensional analysis approach was used to explore the clinical reasoning of nurses who care for hospitalized older adults to identify factors that might explain their failure to detect acute confusion and to distinguish it from dementia in this patient population. Data analysis yielded a grounded theory of situated clinical reasoning, which proposes that the ability of nurses to identify acute confusion varies widely. This variation can be attributed to the differences in nurses' philosophical perspectives on aging. According to this theory, three distinct perspectives are unwittingly embraced by nurses who care for older patients. These perspectives influence how nurses characterize aging and the aged and condition the ways in which they judge and ultimately deal with older adults in clinical situations. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:90–101, 2003
Applying TAF to generate efficient derivative code of Fortran 77‐95 programs
Authors: Giering Ralf , Kaminski Thomas 
Published: April 2003

AbstractThis paper features FastOpt's automatic differentiation (AD) tool Transformation of Algorithms in Fortran (TAF), a source to source translator for programs written in Fortran 77‐95. TAF and its predecessor TAMC have a long record of successful large‐scale applications. Here we give an overview on how TAF approaches typical challenges of AD such as handling of badly written program code, of large memory/disk requirements, of iterative solvers or of black box routines. We also point out, where the user is required to prepare his program code prior to invoking TAF.
Preparation, characterization, and properties of novolac‐type phenolic/SiO2 hybrid organic–inorganic nanocomposite materials by sol–gel method
Authors: Chiang Chin‐Lung , Ma Chen‐Chi M. , Wu Dai‐Lin , Kuan Hsu‐Chiang 
Published: March 2003

AbstractThis article describes the preparation of novolac‐type phenolic resin/silica hybrid organic–inorganic nanocomposite, with a sol–gel process. The coupling agent was used to improve the interface between the organic and inorganic phases. The effect of the structure of the nanocomposite on its physical and chemical properties is discussed. The coupling agent reacts with the resin to form covalent bonds. The structure of the modified hybrid nanocomposites was identified with a Fourier transform infrared spectroscope. The silica network was characterized by nuclear magnetic resonance imaging (29Si NMR). Results revealed that Q4 (tetrasubstituted) and T3 (trisubstituted) are the dominant microstructures. The size of the silica in the phenolic resin was characterized with a scanning electron microscope. The size of the particles of inorganic silica in the modified system was less than 100 nm. The nanocomposite exhibited good transparency. Moreover, the thermal and mechanical properties exhibited significant improvement. The modified hybrid composite exhibited favorable thermal properties. The temperature at which a weight loss of 5% occurred increased from 281 to 350 °C. The flexural strength increased by 6–30%. The limiting oxygen index of the nanocomposite reached 37, and the Underwriters Laboratory test was 94V‐0. Consequently, these materials possess excellent flame‐retardant properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 905–913, 2003
Ethyl‐iso‐butylaluminoxane activated metallocene catalyst for olefin polymerization
Authors: Wang Qi , Hong Jian , Fan Zhiqiang , Tao Ruoyuan 
Published: March 2003

AbstractEthylene and propylene were polymerized by different combinations of metallocenes and aluminoxanes. Ethyl‐iso‐butylaluminoxane (EBAO), which could be easily obtained by direct hydrolysis of Et3Al/iso‐Bu3Al in toluene with water, displayed as good polymerization activity as methylaluminoxane when it was paired with some metallocenes. The UV–visible spectroscopic study on different metallocene/aluminoxane pairs suggests that tightness of the ionic pairs generated from the reaction between metallocene and aluminoxane is different for a fixed metallocenium. The loose ionic pair derived from EBAO prefers the monomer propagation and hinders the interaction between active species, which results in high catalytic activity and molecular weight. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 998–1003, 2003
Copolymerization of styrene and conjugated dienes with half‐sandwich titanium(IV) catalysts: The effect of the ligand structure on the monomer reactivity, monomer sequence distribution, and insertion mode of dienes
Authors: Naga Naofumi , Imanishi Yukio 
Published: March 2003

AbstractThe copolymerization of styrene and 1,3‐butadiene (Bd) or isoprene (Ip) was carried out with half‐sandwich titanium(IV) Cp′TiCl3 catalysts (where Cp′ is cyclopentadienyl 1, indenyl 2, or pentamethylcyclopentadienyl 3) with methylaluminoxane as a cocatalyst. For the copolymerization with Bd, catalyst 3 gave the copolymers containing the highest amount of Bd among the catalysts used. The resulting copolymers were composed of a styrene–Bd multiblock sequence. High melting points were observed in the copolymers prepared with catalyst 1. The structures of hydrogenated poly(styrene‐co‐Bd) were studied by 13C NMR spectroscopy, and the long styrene sequence length was detected in the copolymers prepared with catalyst 1. For styrene/Ip copolymerization, random copolymers were obtained. Among the used catalysts, catalyst 1 gave the copolymers containing the highest amount of Ip. The copolymers prepared with catalyst 1 showed a steep melting point depression with increasing Ip content because of the high ratio of 1,4‐inserted Ip units and/or the low molecular weights of the copolymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 939–946, 2003
Helicity induction on a poly(phenylacetylene) derivative bearing aza‐18‐crown‐6 ether pendants in water
Authors: Nonokawa Ryuji , Yashima Eiji 
Published: March 2003

AbstractA stereoregular poly(phenylacetylene) bearing the bulky aza‐18‐crown‐6 ether as the pendant (poly‐1) formed a predominantly one‐handed helical conformation upon complexation with various chiral compounds, such as amino acids, peptides, aminosugars, amines, and amino alcohols in water. The complexes exhibited an induced circular dichroism (ICD) in the UV–visible region of the polymer main chain. Therefore, poly‐1 can be used as a novel probe for determining the chirality of chiral compounds in water. The assay of 19 common free L‐amino acids gave the same ICD sign at 0 °C except for L‐phenylalanine. The effects of pH, temperature, guest concentration, and organic solvent content on the ICD during the complexation of poly‐1 with chiral compounds were also investigated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1004–1013, 2003
Isolation and identification of cyclic oligomers of the poly(ethylene terephthalate)–poly(ethylene isophthalate) copolymer
Authors: Lim Byung‐Ho , Kwon Soo‐Han , Kang En‐Chang , Park Heon , Lee Hyun‐Woo , Kim Whan‐Gi 
Published: March 2003

AbstractNew cyclic oligomers of the copolymer of poly(ethylene terephthalate) (PET) and poly(ethylene isophthalate) (PEI) were isolated and identified. A condensation polymerization was carried out at a high temperature, and the solid‐state polymerization that followed yielded the high molecular weight polymer. The oligomers were extracted from the high molecular weight PET–PEI copolymer and separated with preparative high performance liquid chromatography techniques. Their chemical structures and properties were analyzed and determined by 1H NMR, differential scanning calorimetry, and mass spectroscopy. The oligomers observed at early retention times were a cyclic dimer and cyclic trimers and consisted of [GT]3, [GI]2, [GI]3, [GT]2[GI]1, and [GT]1[GI]2. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 881–889, 2003
Molecular and structural analysis of a triepoxide‐modified poly(ethylene terephthalate) from rheological data
Authors: Dhavalikar R. , Yamaguchi M. , Xanthos M. 
Published: March 2003

AbstractThe effects of reactive melt modification of poly(ethylene terephthalate) (PET) with a multifunctional epoxide—triglycidyl isocyanurate—that lead to chain extension/branching and formation of gel‐like structures were rheologically characterized. The storage and loss moduli and the complex viscosity of the modified PET were larger than those of the unmodified PET. The elastic or solidlike behavior of PET was enhanced after reactive modification as a result of chain extension/branching. Modified Cole–Cole plots revealed that the modified resins show higher elasticity than the unmodified one. Reactive modification characterized by the presence of long‐chain branching resulted in a wider molecular weight distribution. The effects of mixing temperature and the concentration of modifier corresponding to different stoichiometries were investigated. Higher amounts of modifier resulted in a polymeric structure near the sol–gel transition point whose linear viscoelastic properties obey scaling law. The relaxation spectrum was calculated from the oscillatory shear data by Tschoegl equations. Certain modified resins have rheological properties suitable for process operations such as extrusion foaming, blow molding, and thermoforming. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 958–969, 2003
Convenient synthesis and polymerization of 5,6‐disubstituted dithiophthalides toward soluble poly(isothianaphthene): An initial spectroscopic characterization of the resulting low‐band‐gap polymers
Authors: Polec I. , Henckens A. , Goris L. , Nicolas M. , Loi M. A. , Adriaensens P. J. , Lutsen L. , Manca J. V. , Vanderzande D. , Sariciftci N. S. 
Published: March 2003

AbstractA new synthetic procedure toward substituted dithiophthalides, 5,6‐dialkyloxydithiophthalide and 5,6‐dithioalkyldithiophthalide, is presented. 5,6‐Dithiooctyldithiophthalide was obtained from 4,5‐dichlorophthalic acid in an eight‐step reaction with an overall yield of 26%. 5,6‐Dioctyloxydithiophthalide was obtained from 4,5‐dihydroxyphthalic acid dimethyl ester in a seven‐step reaction (overall yield = 15%). Both monomers were polymerized by a thermal and nonoxidative polymerization that resulted in soluble poly(isothianaphthene) derivatives with a band gap of about 1.2 eV. Photoinduced absorption measurements revealed the existence of charged excitations upon illumination. The photoinduced charge generation, combined with the extensive light‐harvesting properties and the easy processability, makes these materials quite promising for photovoltaic applications. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1034–1045, 2003
Synthesis and ring‐opening (co)polymerization of L‐lysine N‐carboxyanhydrides containing labile side‐chain protective groups
Authors: Hernández Juan Rodríguez , Klok Harm‐Anton 
Published: March 2003

AbstractThis contribution describes the synthesis and ring‐opening (co)polymerization of several L‐lysine N‐carboxyanhydrides (NCAs) that contain labile protective groups at the ϵ‐NH2 position. Four of the following L‐lysine NCAs were investigated: Nϵ‐trifluoroacetyl‐L‐lysine N‐carboxyanhydride, Nϵ‐(tert‐butoxycarbonyl)‐L‐lysine N‐carboxyanhydride, Nϵ‐(9‐fluorenylmethoxycarbonyl)‐L‐lysine N‐carboxyanhydride, and Nϵ‐(6‐nitroveratryloxycarbonyl)‐L‐lysine N‐carboxyanhydride. In contrast to the harsh conditions that are required for acidolysis of benzyl carbamate moieties, which are usually used to protect the ϵ‐NH2 position of L‐lysine during NCA polymerization, the protective groups of the L‐lysine NCAs presented here can be removed under mildly acidic or basic conditions or by photolysis. As a consequence, these monomers may allow access to novel peptide hybrid materials that cannot be prepared from ϵ‐benzyloxycarbonyl‐L‐lysine N‐carboxyanhydride (Z‐Lys NCA) because of side reactions that accompany the removal of the Z groups. By copolymerization of these L‐lysine NCAs with labile protective groups, either with each other or with γ‐benzyl‐L‐glutamate N‐carboxyanhydride or Z‐Lys NCA, orthogonally side‐chain‐protected copolypeptides with number‐average degrees of polymerization ≤20 were obtained. Such copolypeptides, which contain different side‐chain protective groups that can be removed independently, are interesting for the synthesis of complex polypeptide architectures or can be used as scaffolds for the preparation of synthetic antigens or protein mimetics. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1167–1187, 2003