bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular engineering of dye‐doped polymers for optoelectronics
Authors: Ishchenko Alexander 
Published: January 2003

AbstractThe main approaches to molecular engineering of prospective dye‐doped polymer matrices for optoelectronics have been considered. The advantages of such matrices over polymers and dyes separately were analyzed. It was shown that these advantages can be realized in the case where a doping of polymers by low‐molecular‐weight dyed impurities does not essentially distort spectral, luminescent and nonlinear optical properties of the individual components of polymer composition. The influence of polymer nature and chemical constitution of organic dyes on photophysical and photochemical properties of these matrices was analyzed. Processes of dye aggregation in polymers were characterized. Their influence on photophysical properties and the photochemical stability of dye‐doped materials was discussed. The different approaches for struggle with it is offered. The influence of the method of introduction of a dye into a polymer on the output parameters of dyed materials was considered. The main paths of energy degradation of electronic excitation in such materials – internal conversion, electron transfer and photoisomerization – were analyzed. The role of dyes in the process of generation, in recombination and in the carriage of charges in photoconductive polymers was discussed. The prospects for the application of dye‐doped polymer materials as passive Q‐switches of solid‐state lasers, as active laser media with large Stokes shift, as luminescent solar converters and as electroluminescent emitters were demonstrated. Copyright © 2003 John Wiley & Sons, Ltd.
PLA‐PEG nanospheres: new carriers for transmucosal delivery of proteins and plasmid DNA
Authors: Vila Ana , Sánchez Alejandro , Pérez Celso , Alonso María J. 
Published: January 2003

AbstractThere is little doubt that advances in polymer synthesis and in the design of delivery systems will have a profound impact on future therapeutics and immunization practices based on complex molecules such as proteins and plasmids. Our approach in this area has been the design of nanoparticles made of poly(lactic acid)‐poly(ethyleneglycol) (PLA‐PEG), for mucosal delivery of proteins and plasmid DNA. The technologies for the formation of these nanoparticles, were conveniently adapted in order to encapsulate proteins efficiently (i.e., tetanus toxoid) and DNA (i.e., pCMV‐βGal) into a PLA core coated by PEG. These techniques include the w/o/w emulsion–solvent evaporation technique and the w/o emulsion–solvent diffusion technique, both providing high protein/DNA loadings. Results showed that the presence of a PEG coating around the nanoparticles significantly enhanced their stability in the gastrointestinal fluids, as well as in contact with mucus enzymes. This coating was also found to be responsible for the enhanced transport of 125I‐radiolabelled tetanus toxoid and its delivery to the blood circulation and the lymph nodes, following nasal administration to rats. Additionally, fluorescent microscopy studies aimed at examining the interaction and transport of the nanoparticles through the nasal mucosa demonstrated that these nanoparticles can, indeed, cross the nasal epithelium. Finally, the efficacy of these PEG‐coated nanoparticles as nasal vaccine delivery vehicles was shown in vivo. More specifically, the tetanus toxoid‐loaded nanoparticles were able to elicit enhanced and long‐lasting immunogenic responses following nasal administration. On the other hand, a single dose of encapsulated DNA administered intranasally led to a significant systemic antibody response to the encoded protein, confirming that plasmid DNA can be encapsulated in PLA‐PEG nanoparticles with significant retention of biological function. To summarize, the data reported in the present paper provide evidence of the potential of PLA‐PEG nanoparticles as carriers for the transport of proteins and DNA across mucosal surfaces. Copyright © 2003 John Wiley & Sons, Ltd.
Convergent and discriminant construct validity of the internalizing symptoms scale for children with the BASC‐SRP‐C
Authors: MERRELL KENNETH W. , BLADE RICHARD L. , LUND JACQUELINE , KEMPF KARI K.G. 
Published: January 2003

AbstractThis brief report details a study of the construct validity of the Internalizing Symptoms Scale for Children (ISSC) in comparison with the Child Self‐Report Form of the Behavioral Assessment System for Children (BASC). Using self‐reports of 121 students ages 8–12 from general education classes, who were administered both measures, correlational data were obtained between the scores of the two instruments. ISSC factor and total scores were found to have weak associations with the BASC School Adjustment Scales, and negatively associations with the BASC personal adjustment scales, providing discriminant evidence of the construct validity of the ISSC. Moderate to strong correlations were found between ISSC scores and the BASC Clinical Maladjustment, Other Problems, and Emotional Symptoms Index scores, evidencing convergent construct validity between the two measures. These results support the validity and clinical use of the ISSC as a measure of internalizing symptoms and emotional problems. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 139–144, 2003.
Social desirability and behavior rating scales: An exploratory study with the Child Behavior Checklist/4–18
Authors: MERYDITH SCOTT P. , PROUT H. THOMPSON , BLAHA JOHN 
Published: January 2003

AbstractThis study investigated the relationship between the Child Behavior Checklist/4–18 (CBCL/4–18) and two modified measures of social desirability, the Marlowe‐Crowne Social Desirability Scale and the Edwards Social Desirability Scale with a sample of 65 parents of normal children from grades K–7. Results from correlational and multiple regression analyses showed that the Aggressive Behaviors and Attention Problems cross‐informant syndromes were modestly associated with social desirability scale scores. The relevance of findings are discussed in terms of the susceptibility of behavior rating scales to the self‐deception and other‐deception factors of social desirability [Paulhus, D.L. (1984). In: J.P. Robinson et al., (eds.) Measures of social psychological attitudes. (pp. 17–59). San Diego: Academic Press.] and fake‐good response sets. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 225–235, 2003.
Conduct disorder in girls: Diagnostic and intervention issues
Authors: DELLIGATTI NINA , AKIN‐LITTLE ANGELEQUE , LITTLE STEVEN G. 
Published: January 2003

AbstractCurrent prevalence rates of Conduct Disorder (CD) in girls may be an underestimate due to inappropriate diagnostic criteria, biased perceptions by those responsible for reporting problematic behavior, and differential social constraints for each gender. Relatively few published studies of CD and related behaviors in girls exist. Available evidence suggests adolescent girls with CD have a poor outcome including early and violent death, arrest, substance abuse and dependence, antisocial personality disorder, failure to finish high school, pregnancy, sexual promiscuity, and contraction of sexually transmitted disease. Even with its relatively low, possibly underestimated prevalence rate in comparison with that of boys, CD has been found to be the second most common psychiatric disorder in adolescent girls. In addition to examining possible reasons for the lack of research on CD in girls, this article reviews possible risk factors and suggested assessment and intervention strategies for this population. Particular attention is paid to implications for practitioners in the school setting. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 183–192, 2003.
Job satisfaction, burnout, and perceived effectiveness of “in‐house” versus traditional school psychologists
Authors: PROCTOR BRILEY E. , STEADMAN TARA 
Published: January 2003

AbstractThe present study examined whether school psychologists who serve a single school (“In‐House” group) differed from school psychologists who serve several schools concurrently (“Traditional” group) in the three areas of job satisfaction, burnout, and effectiveness as perceived by the school psychologist. A total of 63 school psychology practitioners were surveyed using a 28‐item questionnaire developed specifically for this study that yielded scores for Job Satisfaction, Burnout, and Perceived Effectiveness. Results of a multivariate analysis of variance (MANOVA) indicated that the In‐House group reported higher rates of satisfaction and perceived effectiveness and lower rates of burnout than did the traditional group. Items that distinguished between the two groups related to job diversity, caseload, others' familiarity with the school psychologist, the school psychologists' level of integration into school activities, and administrators' knowledge about the school psychologists' capabilities. Suggestions for further research and implications for current practice are discussed. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 237–243, 2003.
Relations between measures of Cattell‐Horn‐Carroll (CHC) cognitive abilities and mathematics achievement across the school‐age years
Authors: FLOYD RANDY G. , EVANS JEFFREY J. , McGREW KEVIN S. 
Published: January 2003

AbstractCognitive clusters from the Woodcock‐Johnson III (WJ III) Tests of Cognitive Abilities that measure select Cattell‐Horn‐Carroll broad and narrow cognitive abilities were shown to be significantly related to mathematics achievement in a large, nationally representative sample of children and adolescents. Multiple regression analyses were used to predict performance on the Math Calculation Skills and Math Reasoning clusters from the WJ III Tests of Achievement for 14 age groups ranging in age from 6 to 19 years. Comprehension‐Knowledge (Gc) demonstrated moderate relations with Math Calculation Skills after the early school‐age years and moderate to strong relations with Math Reasoning. Fluid Reasoning (Gf), Short‐term Memory (Gsm), and Working Memory generally demonstrated moderate relations with the mathematics clusters. Processing Speed (Gs) demonstrated moderate relations with Math Reasoning during the elementary school years and moderate to strong relations with Math Calculation Skills. During the earliest ages of the analysis, Long‐term Retrieval (Glr) demonstrated moderate relations with the mathematics clusters, and Auditory Processing (Ga) demonstrated moderate relations with Math Calculation Skills. Visual‐Spatial Thinking (Gv) generally demonstrated nonsignificant relations with the mathematics clusters. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 155–171, 2003.
Strategies for structural proteomics of prokaryotes: Quantifying the advantages of studying orthologous proteins and of using both NMR and X‐ray crystallography approaches
Authors: Savchenko Alexei , Yee Adelinda , Khachatryan Anna , Skarina Tatiana , Evdokimova Elena , Pavlova Marina , Semesi Anthony , Northey Julian , Beasley Steven , Lan Ning , Das Rajdeep , Gerstein Mark , Arrowmith Cheryl H. , Edwards Aled M. 
Published: January 2003

AbstractOnly about half of non‐membrane‐bound proteins encoded by either bacterial or archaeal genomes are soluble when expressed in Escherichia coli (Yee et al., Proc Natl Acad Sci USA 2002;99:1825–1830;
Christendat et al., Prog Biophys Mol Biol 200;73:339–345). This property limits genome‐scale functional and structural proteomics studies, which depend on having a recombinant, soluble version of each protein. An emerging strategy to increase the probability of deriving a soluble derivative of a protein is to study different sequence homologues of the same protein, including representatives from thermophilic organisms, based on the assumption that the stability of these proteins will facilitate structural analysis. To estimate the relative merits of this strategy, we compared the recombinant expression, solubility, and suitability for structural analysis by NMR and/or X‐ray crystallography for 68 pairs of homologous proteins from E. coli and Thermotoga maritima. A sample suitable for structural studies was obtained for 62 of the 68 pairs of homologs under standardized growth and purification procedures. Fourteen (eight E. coli and six T. maritima proteins) samples generated NMR spectra of a quality suitable for structure determination and 30 (14 E. coli and 16 T. maritima proteins) samples formed crystals. Only three (one E. coli and two T. maritima proteins) samples both crystallized and had excellent NMR properties. The conclusions from this work are: (1) The inclusion of even a single ortholog of a target protein increases the number of samples for structural studies almost twofold; (2) there was no clear advantage to the use of thermophilic proteins to generate samples for structural studies; and (3) for the small proteins analyzed here, the use of both NMR and crystallography approaches almost doubled the number of samples for structural studies. Proteins 2003;50:392–399. © 2003 Wiley‐Liss, Inc.
Structure of the Clade 1 catalase, CatF of Pseudomonas syringae, at 1.8 Å resolution
Authors: Carpena Xavi , Soriano Manuel , Klotz Martin G. , Duckworth Harry W. , Donald Lynda J. , Melik‐Adamyan William , Fita Ignacio , Loewen Peter C. 
Published: January 2003

AbstractCatalase CatF of Pseudomonas syringae has been identified phylogenetically as a clade 1 catalase, closely related to plant catalases, a group from which no structure has been determined. The structure of CatF has been refined at 1.8 Å resolution by using X‐ray synchrotron data collected from a crystal flash‐cooled with liquid nitrogen. The crystallographic agreement factors R and Rfree are, respectively, 18.3% and 24.0%. The asymmetric unit of the crystal contains a whole molecule that shows accurate 222‐point group symmetry. The crystallized enzyme is a homotetramer of subunits with 484 residues, some 26 residues shorter than predicted from the DNA sequence. Mass spectrometry analysis confirmed the absence of 26 N‐terminal residues, possibly removed by a periplasmic transport system. The core structure of the CatF subunit was closely related to seven other catalases with root‐mean‐square deviations (RMSDs) of 368 core Cα atoms of 0.99–1.30 Å. The heme component of CatF is heme b in the same orientation that is found in Escherichia coli hydroperoxidase II, an orientation that is flipped 180° with respect the orientation of the heme in bovine liver catalase. NADPH is not found in the structure of CatF because key residues required for nucleotide binding are missing; 2129 water molecules were refined into the model. Water occupancy in the main or perpendicular channel of CatF varied among the four subunits from two to five in the region between the heme and the conserved Asp150. A comparison of the water occupancy in this region with the same region in other catalases reveals significant differences among the catalases. Proteins 2003;50:423–436. © 2003 Wiley‐Liss, Inc.
Structure validation by Cα geometry: ϕ,ψ and Cβ deviation
Authors: Lovell Simon C. , Davis Ian W. , Arendall W. Bryan , de Bakker Paul I. W. , Word J. Michael , Prisant Michael G. , Richardson Jane S. , Richardson David C. 
Published: January 2003

AbstractGeometrical validation around the Cα is described, with a new Cβ measure and updated Ramachandran plot. Deviation of the observed Cβ atom from ideal position provides a single measure encapsulating the major structure‐validation information contained in bond angle distortions. Cβ deviation is sensitive to incompatibilities between sidechain and backbone caused by misfit conformations or inappropriate refinement restraints. A new ϕ,ψ plot using density‐dependent smoothing for 81,234 non‐Gly, non‐Pro, and non‐prePro residues with B < 30 from 500 high‐resolution proteins shows sharp boundaries at critical edges and clear delineation between large empty areas and regions that are allowed but disfavored. One such region is the γ‐turn conformation near +75°,−60°, counted as forbidden by common structure‐validation programs; however, it occurs in well‐ordered parts of good structures, it is overrepresented near functional sites, and strain is partly compensated by the γ‐turn H‐bond. Favored and allowed ϕ,ψ regions are also defined for Pro, pre‐Pro, and Gly (important because Gly ϕ,ψ angles are more permissive but less accurately determined). Details of these accurate empirical distributions are poorly predicted by previous theoretical calculations, including a region left of α‐helix, which rates as favorable in energy yet rarely occurs. A proposed factor explaining this discrepancy is that crowding of the two‐peptide NHs permits donating only a single H‐bond. New calculations by Hu et al. [Proteins 2002 (this issue)] for Ala and Gly dipeptides, using mixed quantum mechanics and molecular mechanics, fit our nonrepetitive data in excellent detail. To run our geometrical evaluations on a user‐uploaded file, see MOLPROBITY (http://kinemage.biochem.duke.edu) or RAMPAGE (http://www‐cryst.bioc.cam.ac.uk/rampage). Proteins 2003;50:437–450. © 2003 Wiley‐Liss, Inc.
Structure and dynamics of the potato carboxypeptidase inhibitor by 1H and 15N NMR
Authors: González Carlos , Neira José Luis , Ventura Salvador , Bronsoms Silvia , Rico Manuel , Avilés Francese X. 
Published: January 2003

AbstractThe solution structure and backbone dynamics of the recombinant potato carboxypeptidase inhibitor (PCI) have been characterized by NMR spectroscopy. The structure, determined on the basis of 497 NOE‐derived distance constraints, is much better defined than the one reported in a previous NMR study, with an average pairwise backbone root‐mean‐square deviation of 0.5 Å for the well‐defined region of the protein, residues 7–37. Many of the side‐chains show now well‐defined conformations, both in the hydrophobic core and on the surface of the protein. Overall, the solution structure of free PCI is similar to the one that it shows in the crystal of the complex with carboxypeptidase A. However, some local differences are observed in regions 15–21 and 27–29. In solution, the six N‐terminal and the two C‐terminal residues are rather flexible, as shown by 15N backbone relaxation measurements. The flexibility of the latter segment may have implications in the binding of the inhibitor by the enzyme. All the remaining residues in the protein are essentially rigid (S2 > 0.8) with the exception of two of them at the end of a short 3/10 helix. Despite the small size of the protein, a number of amide protons are protected from exchange with solvent deuterons. The slowest exchanging protons are those in a small two‐strand β‐sheet. The unfolding free energies, as calculated from the exchange rates of these protons, are around 5 kcal/mol. Other protected amide protons are located in the segment 7–12, adjacent to the β‐sheet. Although these residues are not in an extended conformation in PCI, the equivalent residues in structurally homologous proteins form a third strand of the central β‐sheet. The amide protons in the 3/10 helix are only marginally protected, indicating that they exchange by a local unfolding mechanism, which is consistent with the increase in flexibility shown by some of its residues. Backbone alignment‐based programs for folding recognition, as opposite to disulfide‐bond alignments, reveal new proteins of unrelated sequence and function with a similar structure. Proteins 2003;50:410–422. © 2003 Wiley‐Liss, Inc.
Refinement of protein structures in explicit solvent
Authors: Linge Jens P. , Williams Mark A. , Spronk Christian A.E.M. , Bonvin Alexandre M. J. J. , Nilges Michael 
Published: January 2003

AbstractWe present a CPU efficient protocol for refinement of protein structures in a thin layer of explicit solvent and energy parameters with completely revised dihedral angle terms. Our approach is suitable for protein structures determined by theoretical (e.g., homology modeling or threading) or experimental methods (e.g., NMR). In contrast to other recently proposed refinement protocols, we put a strong emphasis on consistency with widely accepted covalent parameters and computational efficiency. We illustrate the method for NMR structure calculations of three proteins: interleukin‐4, ubiquitin, and crambin. We show a comparison of their structure ensembles before and after refinement in water with and without a force field energy term for the dihedral angles; crambin was also refined in DMSO. Our results demonstrate the significant improvement of structure quality by a short refinement in a thin layer of solvent. Further, they show that a dihedral angle energy term in the force field is beneficial for structure calculation and refinement. We discuss the optimal weight for the energy constant for the backbone angle omega and include an extensive discussion of meaning and relevance of the calculated validation criteria, in particular root mean square Z scores for covalent parameters such as bond lengths. Proteins 2003;50:496–506. © 2003 Wiley‐Liss, Inc.
Hydration in proteins observed by high‐resolution neutron crystallography
Authors: Chatake Toshiyuki , Ostermann Andreas , Kurihara Kazuo , Parak Fritz G. , Niimura Nobuo 
Published: January 2003

AbstractIt is well known that water molecules surrounding a protein play important roles in maintaining its structural stability. Water molecules are known to participate in several physiological processes through the formation of hydrogen bonds. However, the hydration structures of most proteins are not known well at an atomic level at present because X‐ray protein crystallography has difficulties to localize hydrogen atoms. In contrast, neutron crystallography has no problem in determining the position of hydrogens with high accuracy.1 In this article, the hydration structures of three proteins are described— myoglobin, wild‐type rubredoxin, and a mutant rubredoxin—the structures of which were solved at 1.5‐ or 1.6‐Å resolution by neutron structure determination. These hydration patterns show fascinating features and the water molecules adopt a variety of shapes in the neutron Fourier maps, revealing details of intermolecular hydrogen bond formation and dynamics of hydration. Our results further show that there are strong relationships between these shapes and the water environments. Proteins 2003;50:516–523. © 2003 Wiley‐Liss, Inc.
Molecular dynamics simulation reveals a surface salt bridge forming a kinetic trap in unfolding of truncated Staphylococcal nuclease
Authors: Gruia Andreea D. , Fischer Stefan , Smith Jeremy C. 
Published: January 2003

AbstractSurface salt bridges are ubiquitous in globular proteins. Their contribution to protein stability has been extensively debated in the past decade. Here, molecular dynamics simulations are performed starting from a non‐equilibrium state of Staphylococcal nuclease (SNase) with C‐terminal truncation (SNaseΔ). The results indicate a key role in the unfolding of the surface salt bridge between arginine 105 and glutamate 135. Experimentally, SNaseΔ is known to be partially unfolded. However, in simulations over 1 ns at 300 K and over 500 ps at 400 K, SNaseΔ remains stable in the native‐like folded conformation, the salt bridge hindering unfolding. When the potential function is altered so as to selectively weaken the salt bridge, which then breaks rapidly at 430 K, the protein starts to unfold. The results suggest that breaking of this salt bridge presents a significant barrier to the unfolding transition of SNaseΔ from a native‐like state to the unfolded state. Potential of mean force calculations indicate that the barrier height for this transition is ∼7 kcal/mol. Proteins 2003;50:507–515. © 2003 Wiley‐Liss, Inc.