bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometric Indices of Bone Strength Are Associated With Physical Activity and Dietary Calcium Intake in Healthy Older Women
Authors: Nurzenski Michelle K , Briffa N Kathryn , Price Roger I , Khoo Benjamin CC , Devine Amanda , Beck Thomas J , Prince Richard L 
Published: December 2006

Abstract
A population-based study on 1008 postmenopausal women identified that the 24% of women achieving high levels of PA and CI had 3.4–4.4% higher femoral bone strength in axial compression and 1.7–5.2% in bending than those achieving low levels, indicating that lifestyle factors influence bone strength in the proximal femur.
Introduction: Extensive research has shown that increased physical activity (PA) and calcium intake (CI) decrease the rate of bone loss; however, there is little research on how these lifestyle variables affect bone geometry. This study was designed to investigate the effects of modifiable lifestyle variables, habitual PA and dietary CI, on femoral geometry in older women.
Materials and Methods: Femoral geometry, habitual PA, and dietary CI were measured in a population-based sample of 1008 women (median age ± interquartile range, 75 ± 4years) enrolled in a randomized controlled trial (RCT) of calcium supplementation. Baseline PA and CI were assessed by validated questionnaires, and 1-year DXA scans (Hologic 4500A) were analyzed using the hip structural analysis technique. Section modulus (Z), an index of bending strength, cross-sectional area (CSA), an index of axial compression strength, subperiosteal width (SPW), and centroid position, the position of the center of mass, were measured at the femoral neck (NN), intertrochanter (IT), and femoral shaft (FS) sites. These data were divided into tertiles of PA and CI, and the results were compared using analysis of covariance (ANCOVA), with corrections for age, height, weight, and treatment (calcium/placebo).
Results and Conclusions: PA showed a significant dose–response effect on CSA all hip sites (p &lt; 0.03) and Z at the narrow neck and intertrochanter sites (p &lt; 0.02). For CI, there was a dose–response effect for centroid position at the intertrochanter (p = 0.03). These effects were additive, such that the women (n = 240) with PA in excess of 65.5 kcal/day and CI in excess of 1039 mg/day had significantly greater CSA (NN, 4.4%; IT, 4.3%; FS, 3.4%) and Z (NN, 3.9%; IT, 5.2%). These data show a favorable association between PA and aspects of bone structural geometry consistent with better bone strength. Association between CI and bone structure was only evident in 1 of 15 variables tested. However, there was evidence that there may be additive effects, whereby women with high levels of PA and CI in excess of 1039 mg/day had significantly greater CSA (NN, 0.4%; FS, 2.1%) and Z (IT, 3.0%) than women with high PA but low CI. These data show that current public health guidelines for PA and dietary CI are not inappropriate where bone structure is the health component of interest.
Low-Density Lipoprotein Receptor–Related Protein 5 (LRP5) Gene Polymorphisms Are Associated With Bone Mass in Both Chinese and Whites
Authors: Xiong Dong-Hai , Lei Shu-Feng , Yang Fang , Wang Liang , Peng Yu-Mei , Wang Wei , Recker Robert R , Deng Hong-Wen 
Published: December 2006

Abstract
In this study, the associations of novel LRP5 variants with BMD variation were detected and some replicated in the two ethnic groups of Chinese and white origins, respectively. These data support the concept that LRP5 variation can contribute to minor and major variation in bone structure.
Introduction: Mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene have been shown to cause both high and low bone mass. However, it is still controversial whether LRP5 is associated with normal BMD variation. This study explored the association of LRP5 with BMD phenotypes at three clinically important skeletal sites—the spine, hip, and ultradistal radius (UD)—in two independent populations of Chinese and white ethnicities, respectively.
Materials and Methods: The Chinese sample consisted of 733 unrelated subjects. The white sample was made up of 1873 subjects from 405 nuclear families. High-density single nucleotide polymorphisms (SNPs) across the whole LRP5 gene were genotyped and analyzed in both samples.
Results: Linkage disequilibrium (LD) analyses showed that the haplotype structures of LRP5 between Chinese and whites were in good agreement. Association tests showed that polymorphisms in block 5 spanning intron 7 to intron 19 of LRP5 significantly associated with spine BMD variation in both samples. Particularly, the significant association of SNP rs491347 in intron 7 with spine BMD in the Chinese sample (p = 0.002) was replicated in whites, even after adjusting for multiple testing (p = 0.005). Its strongly associated SNP rs1784235 could cause the loss of an estrogen receptor α (ERα) binding site in LRP5, which could partially explain the above replicated association. However, we did not observe any significant replication with BMD variation at the hip and UD. After accounting for multiple testing, associations with BMD variation at these two sites were mainly found in Chinese. Sex-stratified analyses further revealed that the LRP5 associations with BMD in Chinese and whites were driven by male and female subjects, respectively.
Conclusions: Our work supported LRP5 genetic variants as possible susceptibility factors for osteoporosis and fractures in humans. Especially, the SNP rs491347 and its strongly associated SNPs (e.g., rs1784235) could be important to human osteoporosis phenotypes.
Calcination of Marls to Produce Roman Cement
Authors: Hughes DC , Jaglin D , Kozlowski R , Mayr N , Mucha D , Weber J 
Published: December 2006

Abstract
Marls were identified from a range of European sources and assessed for their Cementation Index, as proposed by Eckel. Two were selected for calcination in a laboratory kiln; one from Folwark in Poland (CI 1.75) and one from Lillienfeld in Austria (CI 2.03). Analysis of historical documents, while not revealing precise kiln conditions, does suggest that they were such as not to yield complete decarbonation of the calcite. Consequently, a series of calcinations was undertaken in which the peak temperature control of the kiln was set in the range 730°C to 1100°C, with residence times in the range 150 to 1250 min. The airflow through the kiln was sufficient to maintain a minimum oxygen content of at least 12 %. The resulting clinker was ground to comply with the 19th century Austrian Norme. Pastes were produced at w/c = 0.65 and assessed for setting time and strength development (6 h to 1 year). Both parameters were highly dependent upon calcination conditions with both “low” and “high” calcinations producing slower setting and slower strength development than intermediate conditions. Two strength development profiles were identified; one being the expected continuous increase of strength, albeit with a declining rate of increase with time, while the other showed a three-step sequence of high initial strength, a dormant period which could last for many weeks and a final increase in strength to an age of one year. The cements were compared using X-ray diffraction (XRD). Considerable variation in the composition was noted and related to the calcination conditions. Of particular interest is the formation of both α'-belite and β-belite under differing calcination conditions. Clinker particles were also compared using the SEM in back-scattered electron imaging mode and the development of morphology observed.
Low temperature synthesis and characterization of Mn3O4 nanoparticles
Authors: Baykal Abdülhadi , Köseoğlu Yüksel , Şenel Mehmet 
Published: December 2006

AbstractHeating hydrous manganese (II) hydroxide gel at 85 °C for 12 hours produces Mn3O4 nanoparticles. They were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (FTIR). The particle size estimated from the SEM and X-ray peak broadening is approximately 32 nm, showing them to be nanocrystalline. EPR measurements confirm a typical Mn2+signal with a highly resolved hyperfine structure.
An Efficient Bulk‐Heterojunction Photovoltaic Cell Based on Energy Transfer in Graded‐Bandgap Polymers
Authors: Gupta D. , Kabra D. , Kolishetti N. , Ramakrishnan S. , Narayan K. S. 
Published: December 2006

AbstractIt is demonstrated that the energy transfer from low‐conjugated (LC) poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene] (MEHPPV) to high‐conjugated (HC) MEHPPV, coupled with significant electron transfer from HC‐MEHPPV to an acceptor species, offers a viable route for an efficient photodiode over a wide spectral range. An enhanced incident‐photon‐to‐current conversion efficiency (IPCE) of 19 % over a wide spectral range and a power‐conversion efficiency (ηP) of 1 % (under monochromatic illumination at λ ∼ 530 nm and a power density of ca. 1 mW cm–2) are achieved in a ternary polymer‐blend film that consists of HC‐MEHPPV (low bandgap), LC‐MEHPPV (high bandgap), and an acceptor polymer, cyanoPPV (CNPPV), in an optimized ratio. The decisive role of the morphology that emerges during phase separation in the polymer blend is demonstrated by wide‐field photocurrent imaging.
Effect of Nanotube Functionalization on the Coefficient of Thermal Expansion of Nanocomposites
Authors: Wang S. , Liang Z. , Gonnet P. , Liao Y.‐H. , Wang B. , Zhang C. 
Published: December 2006

AbstractSingle‐walled carbon nanotubes (SWNTs) are functionalized through both covalent and noncovalent bonding approaches to enhance dispersion and interfacial bonding. The coefficient of thermal expansion (CTE) of the functionalized‐SWNT‐reinforced epoxy composites are measured with a thermal mechanical analyzer (TMA). Experimental results indicate that changes of the glass‐transition temperature (Tg) in functionalized SWNT–polymer composites are dependent upon the functionalization methods. The CTE below the glass‐transition temperature of nanocomposites with a 1 wt % loading of nanotubes is substantially diminished compared to a neat polymer. A reduction in the CTE of up to 52 % is observed for nanocomposites using functionalized nanotubes. However, the CTE above the Tg significantly increases because of the contribution from phonon mode and Brownian motions of a large number of SWNTs in resin‐crosslinked networks, but the increments are compromised by possible interfacial confinement. A tunable CTE induced through nanotube functionalization has application potentials for high‐performance composites, intelligent materials, and circuit protections.
Ordered Mesoporous Silicate Structures as Potential Templates for Nanowire Growth
Authors: Rice R. L. , Arnold D. C. , Shaw M. T. , Iacopina D. , Quinn A. J. , Amenitsch H. , Holmes J. D. , Morris M. A. 
Published: December 2006

AbstractMesoporous thin films are prepared using a simple sol–gel technique. Using lithographically patterned (100)‐orientated substrates and a dip‐coating method reproducible alignment of the pores across the substrate surface can be obtained. The pores preferentially align parallel to the long side of the channels etched into the surface. The channels within the aligned films are subsequently filled with cobalt (to form nanowire‐type structures) using a supercritical fluid inclusion technique, to allow high‐resolution imaging of the pore by using secondary electron microscopy. The channel structure imposes a strain on the mesoporous arrangement resulting in some variation in d‐spacings compared to simple films. The results indicate that the topographic structure can be used to engineer the placement and directionality of the pore structure and the potential of the aligned mesostructures are discussed.
Inside Front Cover: Self‐Assembly of Diblock‐Copolymer Micelles for Template‐Based Preparation of PbTiO3 Nanograins (Adv. Funct. Mater. 18/2006)
Authors: Kronholz S. , Rathgeber S. , Karthäuser S. , Kohlstedt H. , Clemens S. , Schneller T. 
Published: December 2006

AbstractA bottom‐up fabrication route for PbTiO3 nanograins with dimensions of 30 nm, based on predefined TiO2 nanostructures, is presented on p. 2346 by Karthäuser, Rathgeber, and co‐workers. The patterning of the TiO2 seeds was performed by means of a self‐organized micellar monofilm used as an etching template. The dimensions of the micelle template are transferred across all process steps to the final PbTiO3 nanograins.A bottom‐up fabrication route for PbTiO3 nanograins grown on predefined TiO2 nanostructures used as seeds is presented. The structuring of the TiO2 seeds is performed using a self‐organized template constructed from a gold‐loaded micellar monofilm. With this fabrication process, TiO2 seeds and PbTiO3 grains with diameters of 12 and 30 nm, respectively, are prepared without the need for electron‐beam lithography. The dimensions of the structure imposed by the micellar template are transferred through all the processing steps to the final PbTiO3 grains. Furthermore, it is shown that the intermicelle distance and the degree of order in the dried monofilm is mainly determined by the preparation conditions, such as the pulling velocity in the dipping process and the strength of the surface–micelle interaction, and not necessarily by the architectural properties (block length and ratio) of the diblock copolymers that build the micelles. The intermicelle spacing in the dried film is much smaller than the micelle dimensions in solution, and approaches the dimensions of a fully collapsed micelle when the dipping process is performed slowly enough.
Tunable Wettability by Clicking Counterions Into Polyelectrolyte Brushes
Authors: Azzaroni O. , Brown A. A. , Huck W. T. S. 
Published: December 2006

AbstractPolymer brushes have recently emerged as an extremely versatile way to modify surface properties in a robust and controlled way. The introduction of responsive polymers and block copolymers in polymer‐brush systems has also opened up new routes to ‘smart' surfaces with switchable surface properties. Here, the use of polyelectrolyte brushes as a supramolecular platform for the immobilization of a wide range of species, leading to a tunable wettability of substrates, is presented.
Relationship between composition and properties for stable chitosan films containing lipid microdomains
Authors: Grant J. , Tomba J. P. , Lee H. , Allen C. 
Published: December 2006

AbstractBiocompatible, biodegradable films composed of a hybrid blend of chitosan and egg phosphatidylcholine (ePC) were characterized in terms of composition, morphology, and performance‐related properties. The miscibility between chitosan and ePC for blends of 1 : 0.2 to 1 : 2.5 chitosan : ePC (wt/wt) was examined by differential scanning calorimetry and X‐ray diffraction analysis. The partial miscibility exhibited between chitosan and ePC provided an understanding of the microdomain morphology that was visualized by laser scanning confocal fluorescence microscopy of the films. The stability of the films in physiologically relevant media was assessed by percent weight loss over time. The mechanical properties of the chitosan–ePC films were determined by dynamic mechanical analysis and tensile tests. Interestingly, the dry film composed of a high lipid formulation (1 : 2.5 (wt/wt) chitosan: ePC) had the lowest tensile strength, contained lipid microdomains (10–30 μm in size), and provided the highest degree of stability. Following immersion in phosphate buffer solution, the Young's modulus of the film was found to decrease by more than two orders of magnitude and could be further manipulated by decreasing the lipid content within the film. In this way, relationships between the composition and the physical as well as mechanical properties of the chitosan–ePC blends were established. Furthermore, this study demonstrates the potential usefulness of partially miscible chitosan‐based blends for biomedical purposes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3453–3460, 2007
Polymerization kinetics of methylmethacrylate by oxidation: Reduction system using cerium(IV)/lactic acid in aqueous medium
Authors: Demappa Mahadevaiah T. 
Published: December 2006

AbstractThe kinetics of polymerization of methylmethacrylate initiated by cerium(IV)–lactic acid redox system was studied in an aqueous medium in the temperature range of 25–50°C. The rate of polymerization (Rp) and the rate of cerium(IV) disappearance have been measured. The effects of some water‐miscible organic solvents, cationic, anionic, nonionic surfactants, and complexing agents on the rate of polymerization were investigated. The temperature dependence of the rate was studied, and the activation parameters were computed using the Arrhenius and Eyring plots. The effects of inorganic and organic solvents on polymerization were also investigated. All of them depressed both the initial rate and limiting conversion. A mechanism consistent with the experimental data, involving cerium(IV)–lactic acid complex formation, which generates free radicals, is suggested. The chain termination step of the polymerization reaction is by mutual interaction of the growing macromolecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3498–3505, 2007
Studies on xanthate/dithiocarbamate accelerator combination in NR/BR blends
Authors: Palaty Shiny , Joseph Rani 
Published: December 2006

AbstractZinc butyl xanthate [Zn(bxt)2] was prepared in the laboratory. The effect of this xanthate with zinc diethyl dithiocarbamate (ZDC) on the vulcanization of natural rubber (NR), polybutadiene rubber (BR), and NR/BR blend has been studied at different temperatures. The amounts of Zn (bxt)2 and ZDC in the compounds were optimized by varying the amount of ZDC from 0.75 to 1.5 phr and Zn (bxt)2 from 0.75 to 1.5 phr. The cure characteristics were also studied. HAF filled NR, BR, and NR/BR blend compounds were cured at different temperatures from 60 to 150°C. The sheets were molded and properties such as tensile strength, tear strength, crosslink density and elongation at break, compression set, abrasion resistance, etc. were evaluated. The results show that the mechanical properties of 80NR/20BR blends are closer to that of NR vulcanizates, properties of 60NR/40BR blends are closer to BR vulcanizates, while the 70NR/30BR blends show an intermediate property. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3516–3520, 2007
Synthesis and Bioimaging of Positron‐Emitting 15O‐Labeled 2‐Deoxy‐D‐glucose of Two‐Minute Half‐Life
Authors: Yorimitsu Hideki , Murakami Yoshihiro , Takamatsu Hiroyuki , Nishimura Shintaro , Nakamura Eiichi 
Published: December 2006

AbstractIn positron emission tomography (PET), which exploits the affinity of a radiopharmaceutical for the target organ, a systematic repertoire of oxygen‐15‐labeled PET tracers is expected to be useful for bioimaging owing to the ubiquity of oxygen atoms in organic compounds. However, because of the 2‐min half‐life of 15O, the synthesis of complex biologically active 15O‐labeled organic molecules has not yet been achieved. A state‐of‐the‐art synthesis now makes available an 15O‐labeled complex organic molecule, 6‐[15O]‐2‐deoxy‐D‐glucose. Ultrarapid radical hydroxylation of 2,6‐dideoxy‐6‐iodo‐D‐glucose with molecular oxygen labeled with 15O of two‐minute half‐life provided the target 15O‐labeled molecule. The labeling reaction with 15O was complete in 1.3 min, and the entire operation time starting from the generation of 15O‐containing dioxygen by a cyclotron to the purification of the labeled sugar was 7 min. The labeled sugar accumulated in the metabolically active organs as well as in the bladder of mice and rats. 15O‐labeling offers the possibility of repetitive scanning and the use of multiple PET tracers in the same body within a short time, and hence should significantly expand the scope of PET studies of small animals.
Structural and Magnetic Study of N2, NO, NO2, and SO2 Adsorbed within a Flexible Single‐Crystal Adsorbent of [Rh2(bza)4(pyz)]n
Authors: Kachi‐Terajima Chihiro , Akatsuka Takamasa , Kohbara Masa‐aki , Takamizawa Satoshi 
Published: December 2006

AbstractThe crystalline one‐dimensional compound, [RhII2(bza)4(pyz)]n (1) (bza=benzoate, pyz=pyrazine) demonstrates gas adsorbency for N2, NO, NO2, and SO2. These gas‐inclusion crystal structures were characterized by single‐crystal X‐ray crystallography as 1⋅1.5 N2 (298 K), 1⋅2.5 N2 (90 K), and 1⋅1.95 NO (90 K) under forcible adsorption conditions and 1⋅2 NO2 (90 K) and 1⋅3 SO2 (90 K) under ambient pressure. Crystal‐phase transition to the P$\bar 1$ space group that correlates with gas adsorption was observed under N2, NO, and SO2 conditions. The C2/c space group was observed under NO2 conditions without phase transition. All adsorbed gases were stabilized by the host lattice. In the N2, NO, and SO2 inclusion crystals at 90 K, short interatomic distances within van der Waals contacts were found among the neighboring guest molecules along the channel. The adsorbed NO molecules generated the trans‐NO⋅⋅⋅NO associated dimer with short intermolecular contacts but without the conventional chemical bond. The magnetic susceptibility of the NO inclusion crystal indicated antiferromagnetic interaction between the NO molecules and paramagnetism arising from the NO monomer. The NO2 inclusion crystal structure revealed that the gas molecules were adsorbed in the crystal in dimeric form, N2O4.
DNA Base Trimers: Empirical and Quantum Chemical Ab Initio Calculations versus Experiment in Vacuo
Authors: Kabeláč Martin , Sherer Edward C. , Cramer Christopher J. , Hobza Pavel 
Published: December 2006

AbstractA complete scan of the potential‐energy surfaces for selected DNA base trimers has been performed by a molecular dynamics/quenching technique using the force field of Cornell et al. implemented in the AMBER7 program. The resulting most stable/populated structures were then reoptimized at a correlated ab initio level by employing resolution of the identity, Møller–Plesset second‐order perturbation theory (RI‐MP2). A systematic study of these trimers at such a complete level of electronic structure theory is presented for the first time. We show that prior experimental and theoretical interpretations were incorrect in assuming that the most stable structures of the methylated trimers corresponded to planar systems characterized by cyclic intermolecular hydrogen bonding. We found that stacked structures of two bases with the third base in a T‐shape arrangement are the global minima in all of the methylated systems: they are more stable than the cyclic planar structures by about 10 kcal mol−1. The different behaviors of nonmethylated and methylated trimers is also discussed. The high‐level geometries and interaction energies computed for the trimers serve also as a reference for the testing of recently developed density functional theory (DFT) functionals with respect to their ability to correctly describe the balance between the electrostatic and dispersion contributions that bind these trimers together. The recently reported M052X functional with a polarized triple‐zeta basis set predicts 11 uracil trimer interaction energies with a root‐mean‐square error of 2.3 kcal mol−1 relative to highly correlated ab initio theoretical calculations.