bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the mechanical and thermal properties of cross‐linked poly(methylmethacrylate‐acrylic acid‐allylmethacrylate)‐modified bone cement
Authors: Nien Yu‐Hsun , Chen Jason 
Published: March 2006

AbstractBone cement is used as load‐distributing filler between the prosthesis and the bone, as well as a method to anchor prosthesis in orthopedic implants. One of the disadvantages of using polymethylmethacrylate (PMMA) as bone cement is shrinkage of the cement during polymerization. Shrinkage of the cement during polymerization may lose the good load transfer through the interface between the bone and bone cement, and is a source of prosthetic loosening. A crosslinked poly(methylmethacrylate‐acrylic acid‐allylmethacrylate) was applied to bone cement, because it was found that this copolymer exhibits the ability to absorb body fluids and swell in a controlled manner to compensate shrinkage of the cement during polymerization. In this study, the crosslinked poly(methylmethacrylate‐acrylic acid‐allylmethacrylate) modified bone cement was prepared and characterized using tensile analysis and dynamic mechanical analysis. The results show that the modified bone cement is able to enhance the mechanical properties of bone cement. From dynamic mechanical analysis, the transition temperature and the tan δ value of the cement may be affected by prepolymerized crosslinked poly(methylmethacrylate‐acrylic acid‐allylmethacrylate) powder. From the observation of the fracture surfaces of the cements, the modified bone cement may improve fracture toughness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3727–3732, 2006
Effects of additives with different functional groups on the physical properties of starch/PVA blend film
Authors: Yoon Soon‐Do , Chough Sung‐Hyo , Park Hye‐Ryoung 
Published: March 2006

AbstractThe effects of additives with different functional groups, that is, hydroxyl and carboxyl groups, on the physical properties of starch/PVA blend films were examined. Starch/PVA blend films were prepared by the mixing process. Glycerol (GL) with 3 hydroxyl groups, succinic acid (SA) with 2 carboxyl groups, malic acid (MA) with 1 hydroxyl and 2 carboxyl groups, and tartaric acid (TA) with 2 hydroxyl and 2 carboxyl groups were used as additives. The results of measured tensile strength and elongation verified that hydroxyl and carboxyl groups as functional groups increased the flexibility and strength of the film. The degree of swelling (DS) and solubility (S) of the GL/SA‐added films were low. However, the DS and S of the films with added MA or TA with both hydroxyl and carboxyl groups were comparatively high. When the film was dried at low temperature, the properties of the films evidently improved, probably because hydrogen bonding was activated at low temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3733–3740, 2006
Polyesters from renewable resources: Preparation and characterization
Authors: Bakare I. O. , Pavithran C. , Okieimen F. E. , Pillai C. K. S. 
Published: March 2006

AbstractPolyesters were synthesized with monoglycerides prepared from rubber seed oil, a renewable resource. Monoglycerides were obtained by an alcoholysis method from the oil, which was neat or modified by treatments with different amounts of maleic anhydride at 230°C. The polyester resins were subsequently prepared by the condensation polymerization of the monoglycerides with phthalic anhydride. The monoglycerides and resins were characterized by spectroscopic analysis and measurements of the physicochemical properties. The chemical resistance of the polyesters was also studied. The results revealed that the polyesters prepared from the modified monoglycerides possessed better properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3748–3755, 2006
A structural model of an accessibility of polycarbonate melt to thermooxidative degradation processes
Authors: Kozlov G. V. , Dolbin I. V. , Zaikov G. E. 
Published: March 2006

AbstractIt is shown that the “accessibility” of a polymer for oxidation is the only structural factor and quantitative estimate within the framework of the fractional derivation. The oxidation rate of the “accessible” part of a macromolecular coil is independent on its structure, which allows to assume its dependence only on the chemical constitution of polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 3765–3768, 2006
Preparation and properties of some thermosets derived from allyl‐functional naphthoxazines
Authors: Agag Tarek 
Published: March 2006

AbstractA series of novel naphthoxazine monomers containing allyl functionalities were synthesized from the reaction of 1‐naphthol, 2‐naphthol, and 1,5‐dihdroxynaphthalene with allylamine and formalin. Another series of naphthoxazines were similarly prepared by using aniline instead of allylamine for comparison. The chemical structures of these novel monomers were confirmed by IR, 1H NMR, and elemental analysis. DSC of the aniline‐ based naphthoxazines showed an exotherm due to the ring‐opening polymerization of oxazine. For allylamine‐based naphthoxazines, two exotherms were observed. The first exotherm is attributed to the thermal crosslinking of the allyl group and the second is due to the ring‐ opening polymerization of oxazine. The thermal cure of the allylamine‐based naphthoxazine monomers gave thermoset resins with novel structure comprising of polynaphthoxazine with extended network via the polymerization of allyl functionalities. Dynamic mechanical analyses and thermogravimetric analyses showed that the thermosets derived from allyl‐ functional naphthoxazines have high Tg's and stable storage moduli to higher temperature as well as better thermal stability than that of aniline‐based naphthoxazines. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3769–3777, 2006
Structural and functional classes of multipolar cells in the ventral cochlear nucleus
Authors: Doucet John R. , Ryugo David K. 
Published: March 2006

AbstractMultipolar cells in the ventral cochlear nucleus (VCN) are a structurally and functionally diverse group of projection neurons. Understanding their role in the ascending pathway involves partitioning multipolar cells into distinct populations and determining where in the brain each sends its coded messages. In this study, we used retrograde labeling techniques in rats to identify multipolar neurons that project their axons to the ipsilateral dorsal cochlear nucleus (DCN), the contralateral CN, or both structures. Three rats received injections of biotinylated dextran amine in the ipsilateral DCN and diamidino yellow in the contralateral CN. Several radiate multipolar neurons (defined by their axonal projections to the ipsilateral DCN and their dendrites that traverse VCN isofrequency sheets) were double‐labeled but over 70% were not. This result suggests two distinct populations: (1) radiate‐commissural (RC) multipolar cells that project to the ipsilateral DCN and the contralateral CN, and (2) radiate multipolar cells that project exclusively (in this context) to the ipsilateral DCN. In a different group of animals, we retrogradely labeled multipolar neurons that project their axons to the contralateral CN and measured the size of their cell bodies. The mean size of this population (266 ± 156 μm2) was significantly smaller than those of RC‐multipolar cells (418 ± 140 μm2). We conclude that the CN commissural pathway is composed of at least two components: (1) RC multipolar cells and (2) commissural multipolar cells that are small‐ and medium‐sized neurons that project exclusively (in this context) to the contralateral CN. These results identify separate structural groups of multipolar cells that may correspond to physiological unit types described in the literature. They also provide protocols for isolating and studying different populations of multipolar cells to determine the neural mechanisms that govern their responses to sound. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Differential representation of speech sounds in the human cerebral hemispheres
Authors: Firszt Jill B. , Ulmer John L. , Gaggl Wolfgang 
Published: March 2006

AbstractVarious methods in auditory neuroscience have been used to gain knowledge about the structure and function of the human auditory cortical system. Regardless of method, hemispheric differences are evident in the normal processing of speech sounds. This review article, augmented by the authors' own work, provides evidence that asymmetries exist in both cortical and subcortical structures of the human auditory system. Asymmetries are affected by stimulus type, for example, hemispheric activation patterns have been shown to change from right to left cortex as stimuli change from speech to nonspeech. In addition, the presence of noise has differential effects on the contribution of the two hemispheres. Modifications of typical asymmetric cortical patterns occur when pathology is present, as in hearing loss or tinnitus. We show that in response to speech sounds, individuals with unilateral hearing loss lose the normal asymmetric pattern due to both a decrease in contralateral hemispheric activity and an increase in the ipsilateral hemisphere. These studies demonstrate the utility of modern neuroimaging techniques in functional investigations of the human auditory system. Neuroimaging techniques may provide additional insight as to how the cortical auditory pathways change with experience, including sound deprivation (e.g., hearing loss) and sound experience (e.g., training). Such investigations may explain why some populations appear to be more vulnerable to changes in hemispheric symmetry such as children with learning problems and the elderly. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Genetics of hearing loss: Allelism and modifier genes produce a phenotypic continuum
Authors: Mchugh Richard K. , Friedman Rick A. 
Published: March 2006

AbstractRecent genetic and genomic studies have greatly advanced our knowledge of the structure and function of genes involved in hearing loss. We are starting to recognize, however, that many of these genes do not appear to follow traditional Mendelian expression patterns and are subject to the effects of allelism and modifier genes. This review presents two genes illustrative of this concept that have varied expression pattern such that they may produce either syndromic or nonsyndromic hearing loss. One of these genes, cadherin 23, produces a spectrum of phenotypic traits, including presbycusis, nonsyndromic prelingual hearing loss (DFNB12), and syndromic hearing loss as part of Usher syndrome (Usher 1D). Missense mutations in CDH23 have been associated with presbycusis and DFNB12, whereas null alleles cause the majority of Usher 1D. Modifier gene products that interact with cadherin 23 also affect the phenotypic spectrum. Similarly, allelsim in the gene encoding wolframin (WFS1) causes either a nonsyndromic dominant low‐frequency hearing loss (DFNA6/14/38) or Wolfram syndrome. Missense mutations within a defined region are associated with DFNA6/14/38, while more severe mutations spanning WFS1 are found in Wolfram syndrome patients. The phenotypic spectrum of Wolfram syndrome is also hypothesized to be influenced by modifier genes products. These studies provide increasing evidence for the importance of modifier genes in elucidating the functional pathways of primary hearing loss genes. Characterizing modifier genes may result in better treatment options for patients with hearing loss and define new diagnostic and therapeutic targets. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Comparative gene expression analysis reveals a characteristic molecular profile of the superior olivary complex
Authors: Nothwang Hans Gerd , Koehl Alexander , Friauf Eckhard 
Published: March 2006

AbstractThe superior olivary complex (SOC) is a very conspicuous structure in the mammalian auditory brainstem. It represents the first binaural processing center and is important for sound localization in the azimuth and in feedback regulation of cochlear function. In order to define molecular determinants of the SOC, which are of potential functional relevance, we have performed a comprehensive analysis of its transcriptome by serial analysis of gene expression in adult rats. Here, we performed a detailed analysis of the SOC's gene expression profile compared to that of two other neural tissues, the striatum and the hippocampus, and with extraocular muscle tissue. This tested the hypothesis that SOC‐specific or significantly upregulated transcripts provide candidates for the specific function of auditory neurons. Thirty‐three genes were significantly upregulated in the SOC when compared to the two other neural tissues. Thirteen encoded proteins involved in neurotransmission, including action potential propagation, exocytosis, and myelination; five genes are important for the energy metabolism, and five transcripts are unknown or poorly characterized and have yet to be described in the nervous system. The comparison of functional gene classes indicates that the SOC has the highest energy demand of the three neural tissues, yet protein turnover is apparently not increased. This suggests a high energy demand for fueling auditory neurotransmission. Such a demand may have implications on auditory‐specific tasks and relate to central auditory processing disorders. Ultimately, these data provide new avenues to foster investigations of auditory function and to advance molecular physiology in the central auditory system. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Differential expression of cytoskeletal genes in the cochlear nucleus
Authors: Friedland David R. , Popper Paul , Eernisse Rebecca , Ringger Benjamin , Cioffi Joseph A. 
Published: March 2006

AbstractThe relationship between structure and function is clearly illustrated by emerging evidence demonstrating the role of the neuronal cytoskeleton in physiological processes. For example, alterations in axonal caliber, a feature of the cytoskeleton, have been shown to affect reflex arc latencies and are prominent features of several neuropathological disorders. Even in the nonpathologic situation, however, axonal diameter may be a crucial element for the normal function of specialized auditory neurons. To investigate this relationship, we used serial analysis of gene expression and microarray analyses to characterize the expression of cytoskeletal genes in the central auditory system. These data, confirmed by real‐time RT‐PCR, identified differential expression of intermediate neurofilament transcripts (i.e., Nefh, Nef3, and Nfl) among the subdivisions of the cochlear nucleus. In situ hybridization was used to identify specific classes of neurons within the cochlear nucleus expressing these neurofilament genes. Robust neurofilament expression was seen in bushy cells and cochlear nerve root neurons, suggesting an association between cytoskeletal structure and rapid conduction velocities. Gene expression data were also identified for other classes of cytoskeletal and structural genes important in neuronal function. These results may help to explain some causes of hearing loss in hereditary neuropathies and provide an anatomic basis for understanding normal neuronal function in the central auditory system. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Semicircular canal geometry, afferent sensitivity, and animal behavior
Authors: Hullar Timothy E. 
Published: March 2006

AbstractThe geometry of the semicircular canals has been used in evolutionary studies to predict the behaviors of extinct animals. These predictions have relied on an assumption that the responses of the canals can be determined from their dimensions, and that an organism's behavior can be determined from these responses. However, the relationship between a canal's sensitivity and its size is not well known. An intraspecies comparison among canal responses in each of three species (cat, squirrel monkey, and pigeon) was undertaken to evaluate various models of canal function and determine how their dimensions may be related to afferent physiology. All models predicted the responses of the cat afferents, but the models performed less well for squirrel monkey and pigeon. Possible causes for this discrepancy include incorrectly assuming that afferent responses accurately represent canal function or errors in current biophysical models of the canals. These findings leave open the question as to how reliably canal anatomy can be used to estimate afferent responses and how closely afferent responses are related to behavior. Other labyrinthine features, such as orientation of the horizontal canal, which is reliably held near earth‐horizontal across many species, may be better to use when extrapolating the posture and related behavior of extinct animals from labyrinthine morphology. Anat Rec Part A, 2006. © 2006 Wiley‐Liss, Inc.
Structural and functional neural correlates of music perception
Authors: Limb Charles J. 
Published: March 2006

AbstractThis review article highlights state‐of‐the‐art functional neuroimaging studies and demonstrates the novel use of music as a tool for the study of human auditory brain structure and function. Music is a unique auditory stimulus with properties that make it a compelling tool with which to study both human behavior and, more specifically, the neural elements involved in the processing of sound. Functional neuroimaging techniques represent a modern and powerful method of investigation into neural structure and functional correlates in the living organism. These methods have demonstrated a close relationship between the neural processing of music and language, both syntactically and semantically. Greater neural activity and increased volume of gray matter in Heschl's gyrus has been associated with musical aptitude. Activation of Broca's area, a region traditionally considered to subserve language, is important in interpreting whether a note is on or off key. The planum temporale shows asymmetries that are associated with the phenomenon of perfect pitch. Functional imaging studies have also demonstrated activation of primitive emotional centers such as ventral striatum, midbrain, amygdala, orbitofrontal cortex, and ventral medial prefrontal cortex in listeners of moving musical passages. In addition, studies of melody and rhythm perception have elucidated mechanisms of hemispheric specialization. These studies show the power of music and functional neuroimaging to provide singularly useful tools for the study of brain structure and function. Anat Rec Part A, 2006. Published 2006 Wiley‐Liss, Inc.
Managing déjà vu: Collection building for the identification of nonidentical duplicate documents
Authors: Conrad Jack G. , Schriber Cindy P. 
Published: March 2006

AbstractAs online document collections continue to expand, both on the Web and in proprietary environments, the need for duplicate detection becomes more critical. Few users wish to retrieve search results consisting of sets of duplicate documents, whether identical duplicates or close variants. The goal of this work is to facilitate (a) investigations into the phenomenon of near duplicates and (b) algorithmic approaches to minimizing its deleterious effect on search results. Harnessing the expertise of both client‐users and professional searchers, we establish principled methods to generate a test collection for identifying and handling nonidentical duplicate documents. We subsequently examine a flexible method of characterizing and comparing documents to permit the identification of near duplicates. This method has produced promising results following an extensive evaluation using a production‐based test collection created by domain experts.
Dosimetric assessment of an exposure system for simulating GSM and WCDMA mobile phone usage
Authors: Bahr Achim , Dorn Hans , Bolz Thomas 
Published: March 2006

AbstractAn exposure system for investigation of volunteers during simulated GSM and WCDMA mobile phone usage has been designed. The apparatus consists of a dual band antenna with enhanced carrying properties that enables exposure for at least 8 h a day. For GSM a 900 MHz pulse modulated carrier was used. The QPSK modulated WCDMA signal at 1966 MHz comprises a power control scheme, which was designed for investigations of biological effects. The dosimetry of the exposure system by measurements and calculations is described in detail within this paper. It is shown that the SAR distribution of the antenna shows similar characteristics to mobile phones with an integrated antenna. The 10 g averaged localized SAR, normalized to an antenna input power of 1 W and measured in the flat phantom area of the SAM phantom, amounts to 7.82 mW/g (900 MHz) and 10.98 mW/g (1966 MHz). The simulated SAR10g in the Visible Human head model agrees with measured values to within 20%. A variation of the antenna rotation angle results in an SAR10g change below 17%. The increase of the antenna distance by 2 mm with respect to the human head leads to an SAR10g change of 9%. Bioelectromagnetics 27:320–327, 2006. © 2006 Wiley‐Liss, Inc.
Conformational differences in protein disulfide linkages between normal hair and hair from subjects with trichothiodystrophy: A quantitative analysis by Raman microspectroscopy
Authors: Schlücker S. , Liang C. , Strehle K. R. , DiGiovanna J. J. , Kraemer K. H. , Levin I. W. 
Published: March 2006

AbstractRaman spectra of normal hair shafts and hair shafts from patients exhibiting trichothiodystrophy (TTD) were obtained using line focus laser illumination. Because hair from TTD patients has a significant decrease in the content of the sulfur‐containing amino acids in comparison to normal hair, the 550–500 cm−1 disulfide stretching mode region of the Raman spectrum was examined in detail. A quantitative spectral analysis demonstrates significant increases in the two energetically less favored gauche–gauche–trans (g‐g‐t) and trans–gauche–trans (t‐g‐t) forms. These observations suggest that the increased amounts of these less stable disulfide conformers are contributing factors to or associated with the hair brittleness observed for this congenital disorder. Structure–spectra correlations for the three dominant disulfide conformers are confirmed by quantum chemical calculations using modern density functional theory (DFT). © 2006 Wiley Periodicals, Inc. Biopolymers 82: 615–622, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Synthesis of Aminooxy‐Functionalized Lanthanide(III) Chelates for Carbonyl‐Group Conjugation
Authors: Hovinen Jari 
Published: March 2006

AbstractThe syntheses of three new aminooxy‐tethered lanthanide(III) chelates, compounds 1–3, incorporating DOTA (=1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid), DTPA (=diethylenetriaminepentaacetic acid), or a substituted terpyridine (2,2′,2″,2′′′‐[2,2′: 6′,2″‐terpyridine‐6,6″‐diylbis(methylenenitrilo)]tetraacetic acid), respectively, are described. Reagents 1–3 can be used for carbonyl ‘labeling’, as shown by the formation of the corresponding oxime‐ether bioconjugates of naltrexone (16) and 2‐deoxy‐β‐D‐glucose (17) (Scheme 4).