bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fat mass accumulation compromises bone adaptation to load in finnish women: A cross-sectional study spanning three generations
Authors: Xu Leiting , Nicholson Patrick , Wang Qing-Ju , Wang Qin , Alén Markku , Cheng Sulin 
Published: May 2010

Abstract
Body weight and lean mass correlate with bone mass, but the relationship between fat mass and bone remains elusive. The study population consisted of 396 girls and 138 premenopausal mothers and 114 postmenopausal grandmothers of these girls. Body composition and tibial length were assessed using dual-energy X-ray absorptiometry (DXA), and bone traits were determined at the tibia using peripheral quantitative computed tomography (pQCT) in the girls at the ages of 11.2 ± 0.8, 13.2 ± 0.9, and 18.3 ± 1.0 years and in the mothers (44.7 ± 4.1 years) and grandmothers (70.7 ± 6.3 years). The values of relative bone strength index (RBSI), an index reflecting the ratio of bone strength to the load applied on the tibia, were correlated among family members (all p &lt; .05). The mean values of RBSI were similar among 11- and 18-year-old girls and premenopausal women but significantly lower in 13-year-old girls and postmenopausal women. However, in each age group, subjects in the highest BMI tertiles had the lowest RBSI values (all p &lt; .01). RBSI was inversely associated with body weight (all p &lt; .01), indicating a deficit in bone strength relative to the applied load from greater body weight. RBSI was inversely associated with fat mass (all p &lt; .001) across age groups and generations but remained relatively constant with increasing lean mass in girls and premenopausal women (all p &gt; .05), indicating that the bone-strength deficit was attributable to increased fat mass, not lean mass. Moreover, the adverse effect of fat mass was age-dependent, with every unit increase in fat mass associated with a greater decrease in RBSI in pre- and postmenopausal women than in girls (all p &lt; .001). This is largely due to the different capacity of young and adult bones to increase diaphyseal width by periosteal apposition in response to increased load. In summary, increasing body weight with fat accumulation is accompanied by an age-dependent relative bone-strength deficit in women because the beneficial effects of increased fat mass on bone, if any, do not compensate for the mechanical burden that it imposes. © 2010 American Society for Bone and Mineral Research.
Molecular silencing of Twist1 enhances osteogenic differentiation of murine mesenchymal stem cells: Implication of FGFR2 signaling
Authors: Miraoui Hichem , Severe Nicolas , Vaudin Pascal , Pagès Jean‐Christophe , Marie Pierre J. 
Published: May 2010

AbstractThe capacity of mesenchymal stem cells (MSCs) to differentiate into functional osteoblasts is tightly controlled by transcription factors that trigger osteoblast commitment and differentiation. The role of Twist1, a basic helix‐loop‐helix (bHLH) transcription factor, in osteogenic differentiation of MSCs remains unclear. Here we investigated the role of Twist1 in the osteogenic differentiation program of murine C3H10T1/2 mesenchymal cells. We showed that molecular silencing of Twist1 using short hairpin RNA (shRNA) expression moderately increased C3H10T1/2 cell proliferation and had no effect on cell survival. In contrast, Twist1 silencing enhanced osteoblast gene expression and matrix mineralization in vitro. Biochemical analyses revealed that Twist1 silencing increased the expression of FGFR2 protein level, which was reduced by a mutant Runx2. Consistent with this finding, Twist1 silencing increased ERK1/2 and PI3K signaling. Moreover, molecular or pharmacological inhibition of FGFR2 or of ERK1/2 and PI3K signaling partly abolished the increased osteoblast gene expression induced by Twist1 silencing in C3H10T1/2 cells. These results reveal that Twist1 silencing upregulates osteoblast differentiation of murine mesenchymal cells in part via activation of FGFR2 expression and downstream signaling pathways, which provides novel insights into the molecular signals by which this transcription factor regulates the osteogenic differentiation program in MSCs. J. Cell. Biochem. 110: 1147–1154, 2010. Published 2010 Wiley‐Liss, Inc.
Poly (ADP‐ribose) polymerase‐1 binds to BCL2 major breakpoint region and regulates BCL2 expression
Authors: Yang Nan , Gong Feiran , Sun Luan , Yang Dapeng , Han Xiao , Ma Changyan , Sun Yujie 
Published: May 2010

AbstractBCL2, originally identified as a proto‐oncogene in B‐cell lymphoma, is a key regulator of apoptosis. Although it is more than 200 kb in length, at least 70% of the t(14;18) translocation in follicular lymphomas occurs at the BCL2 major breakpoint region (mbr), located in the 3′‐untranslated region (3'‐UTR). We have previously found that the mbr is a regulatory element which positively regulates BCL2 expression and this regulatory function was closely associated with SATB1, which binds to a 37 bp mbr (37 mbr) in the 3′‐end of the mbr directly. However, the precise molecular mechanisms by which the mbr regulates gene expression are not fully understood. In this study, we purified Poly(ADP‐ribose) polymerase‐1 (PARP‐1) from the DNA–protein complexes formed by 37 mbr in Jurkat cells and demonstrated that PARP‐1 participates in the 37 mbr–protein complex's formation in vitro and in vivo. Functional analysis showed that overexpression of PARP‐1 decreases 37 mbr regulatory function and BCL2 expression. Conversely, knockdown of PARP‐1 with RNAi increases BCL2 expression. Taken together, the present findings indicate that PARP‐1 is a component of BCL2 37 mbr–protein complexes, and PARP‐1 is involved in the regulation of BCL2 expression. These findings are helpful in understanding the regulatory mechanisms of BCL2 expression. J. Cell. Biochem. 110: 1208–1218, 2010. Published 2010 Wiley‐Liss, Inc.
Chemical reactivity predictions: Use of data mining techniques for analyzing regioselective azidolysis of epoxides
Authors: Borghini Alice , Crotti Paolo , Pietra Daniele , Favero Lucilla , Bianucci Anna Maria 
Published: May 2010

AbstractAzidolysis of epoxides followed by reduction of the intermediate azido alcohols constitutes a valuable synthetic tool for the construction of β‐amino alcohols, an important chemical functionality occurring in many biologically active compounds of natural origin. However, depending on conditions under which the azidolysis is carried out, two regioisomeric products can be formed, as a consequence of the nucleophilic attack on both the oxirane carbon atoms. In this work, predictive models for quantitative structure‐reactivity relationships were developed by means of multiple linear regression, k‐nearest neighbor, locally weighted regression, and Gaussian Process regression algorithms. The specific nature of the problem at hand required the creation of appropriate new descriptors, able to properly reflect the most relevant features of molecular moieties directly involved in the opening process. The models so obtained are able to predict the regioselectivity of the azidolysis of epoxides promoted by sodium azide, in the presence of lithium perchlorate, on the basis of steric hindrance, and charge distribution of the substituents directly attached to the oxirane ring. © 2010 Wiley Periodicals, Inc. J Comput Chem 2010
A density‐functional study of the phase diagram of cementite‐type (Fe,Mn)3C at absolute zero temperature
Authors: Von Appen Jörg , Eck Bernhard , Dronskowski Richard 
Published: May 2010

AbstractThe phase diagram of (Fe1−x Mnx)3C has been investigated by means of density‐functional theory (DFT) calculations at absolute zero temperature. The atomic distributions of the metal atoms are not random‐like as previously proposed but we find three different, ordered regions within the phase range. The key role is played by the 8d metal site which forms, as a function of the composition, differing magnetic layers, and these dominate the physical properties. We calculated the magnetic moments, the volumes, the enthalpies of mixing and formation of 13 different compositions and explain the changes of the macroscopic properties with changes in the electronic and magnetic structures by means of bonding analyses using the Crystal Orbital Hamilton Population (COHP) technique. © 2010 Wiley Periodicals, Inc. J Comput Chem 2010
Morphology of epithelial cells lining the digestive tract of the giant keyhole limpet, Megathura crenulata (Mollusca; Vetigastropoda)
Authors: Martin Gary G. , Bessette Tracy , Martin Alanna , Cotero Renae , Vumbaco Kathryn , Oakes Christopher 
Published: May 2010

AbstractTo understand the digestive functions in the giant keyhole limpet, it is important to know the types of cells present in each region of the gut and their roles in the secretion of digestive enzymes and absorption of nutrients. This study describes the morphology of cells lining the entire gut and identifies sites that may be secreting materials to aid digestion. Previous studies involving electron microscopy and enzyme analysis have focused on the salivary and digestive glands of several gastropods. Studies on the rest of the gut tract typically include only histological descriptions of the epithelia and although several types of cells have been described, they appear very similar. The purpose of this study is to determine if electron microscopy can provide better insights into the functions of cells in these poorly studied regions of the gut. Our ultrastructural observations suggest that only two types of cells, mucus secreting cells and apocrine secretory cells make up the epithelium in the esophagus, style sac, and intestine. These regions account for 85% of the length of the entire digestive tract. Apocrine secretory cells contain pigment granules, bear cilia, and/or microvilli at their apices, and release product into the gut lumen via apocrine secretion. This suggests that the secretory processes involved with digestion are occurring in most regions of the gut and that apocrine secretion is the primary mode by which materials are introduced into the gut lumen. The lips, salivary glands, stomach, and digestive gland lack apocrine secretory cells and the epithelial cells are similar to those described in other gastropods. J. Morphol. 271:1134–1151, 2010. © 2010 Wiley‐Liss, Inc.
Inhibition of uPAR and uPA reduces invasion in papillary thyroid carcinoma cells
Authors: Nowicki Theodore S. , Kummer Nicolas T. , Iacob Codrin , Suslina Nina , Schaefer Steven , Schantz Stimson , Shin Edward , Moscatello Augustine L. , Tiwari Raj K. , Geliebter Jan 
Published: May 2010

AbstractObjectives/Hypothesis:We analyzed the expression of urokinase plasminogen activator (uPA) and its receptor (uPAR) in papillary thyroid carcinoma (PTC) and normal thyroid tissue and examined in vitro how uPA and uPAR contribute to an invasive/metastatic phenotype, and the functional consequences of inhibiting this system.Study Design:Retrospective chart review of PTC patients, followed by prospective study using previously obtained patient tissue and PTC cellular models.Methods:uPA and uPAR RNA and protein levels were analyzed in PTC patient tissue samples, PTC and normal thyroid tissue culture cells, and conditioned media (CM) using quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) and/or Western blotting. The plasminogen‐activating ability of CM was examined using dark‐quenched casein fluorimetry and casein‐plasminogen gel zymography. The invasive potentials of the PTC and normal thyroid epithelial cell lines were assessed using an in vitro cellular invasion/migration system.Results:uPA and uPAR RNA and protein levels were increased in PTC patient samples and PTC cells relative to controls. uPA and uPAR RNA were also significantly higher in patients with metastatic disease. Casein‐plasminogen zymography and Western blotting demonstrated increased active uPA secreted by PTC cells compared with normal thyroid cells. Fluorimetric assays revealed that the PTC cells' CM was able to activate plasminogen, resulting in measurable casein hydrolysis. This casein hydrolysis was prevented by the addition of several specific uPA inhibitors. Finally, the in vitro invasion phenotypes of PTC cells were augmented by the addition of plasminogen, and this augmentation was reversed by inhibitory anti‐uPA and anti‐uPAR antibodies.Conclusions:These data provide new functional evidence of the uPA/uPAR system's role in PTC invasion/metastasis and demonstrate the attractiveness of uPA and uPAR as molecular biomarkers and therapeutic targets.
A Polycation Scaffold Presenting Tunable “Click” Sites: Conjugation to Carbohydrate Ligands and Examination of Hepatocyte‐Targeted pDNA Delivery
Authors: Lee Chen‐Chang , Grandinetti Giovanna , McLendon Patrick M. , Reineke Theresa M. 
Published: May 2010

AbstractA versatile polycation scaffold that can easily be modified with targeting ligands has been designed, synthesized, and characterized. A series of galactose‐containing polymers has been produced to demonstrate the ease of modification of this polynucleotide delivery vehicle motif via the click reaction and to study how various structural modifications affect recognition by ASGPr on hepatocytes. A small library of structures was created where DCS and alkyl spacer length between the targeting group and the polymer backbone was varied. The novel polymer scaffold described proves to be a valuable tool for understanding structure/activity relationships of complexes made with receptor‐targeted polymers.magnified image
Accounting for Solvent Signal Offsets in the Analysis of Interferometric Sedimentation Velocity Data
Authors: Zhao Huaying , Brown Patrick H. , Balbo Andrea , Fernández‐Alonso María del Carmen , Polishchuck Natasha , Chaudhry Charu , Mayer Mark L. , Ghirlando Rodolfo , Schuck Peter 
Published: May 2010

AbstractSedimentation velocity (SV) analytical ultracentrifugation has re‐emerged as an important tool in the characterization of biological macromolecules and nanoparticles. The computational analysis of the evolution of the macromolecular concentration profile allows the characterization of many hydrodynamic and thermodynamic properties of the macromolecules and their interactions. The Rayleigh interference optical system is often the detection method of choice, for its usually superior data quality and the wide applicability of refractive index sensitive detection. However, the interference optical system is also sensitive to the redistribution of co‐solvent molecules, which are not of primary experimental interest. In principle, their contribution can be eliminated by an exact geometric and compositional match of the sample solution and the reference solution, achieving the complete optical subtraction of unwanted buffer signals. Unfortunately, in practice, this can often not be perfectly achieved for various reasons, leading to signal offsets arising from unmatched sedimentation of solvent components. If unrecognized, this can lead to significant misfit, accompanied by significant errors in the macromolecular sedimentation parameters. In the present work, we describe an approach of computationally accounting for signals from sedimenting buffer components through explicitly modeling their redistribution with Lamm equation solutions, implemented in the software SEDFIT. We demonstrate how this can restore the SV analysis to yield a high quality fit of the data and to provide correct macromolecular sedimentation parameters.magnified image
Towards Semiconducting Graft Copolymers: Switching from ATRP to “Click” Approach
Authors: Bolognesi Alberto , Galeotti Francesco , Mróz Wojciech , Gancheva Valeria , Terlemezyan Levon 
Published: May 2010

AbstractThe synthesis of two polyconjugated graft copolymers based on a poly(fluorene‐phenylene) backbone and polystyrene side chains is described here. The two different approaches followed, ATRP growth of side chains from a preformed conjugated backbone and “click” connection of well‐defined polymeric chains to the backbone, led to different results in terms of solubility and material properties. While the ATRP method seems to be responsible of a partially cross‐linked and nonsoluble copolymer, the “click” approach provides a graft copolymer, which is completely soluble, showing atypical spectroscopic properties that are here elucidated.magnified image
Highly Flexible Electronic and Optical Films Composed of Hydrophobic and Hydrophilic Multilayers
Authors: Kim Sungwoo , Lee Bokyoung , Kim Sanghyo , Bang Joona , Cho Jinhan 
Published: May 2010

AbstractWe introduce a novel and efficient strategy for producing free‐standing functional films via photo‐crosslinking and electrostatic layer‐by‐layer (LbL) assembly, which can allow the build‐up of hydrophilic multilayers onto hydrophobic surfaces. Hydrophobic multilayers were deposited on ionic substrates by a photo‐crosslinking LbL process using photo‐crosslinkable polymers. The photo‐crosslinked surface was converted to an anionic surface by excess UV light irradiation. This treatment allowed also the stable adhesion between metal electrode or cationic polyelectrolyte and hydrophobic multilayers. After dissolving the ionic substrates in water, the formed free‐standing films exhibited unique functionalities of inserted components within hydrophobic and/or hydrophilic multilayers.magnified image
Poly[(vinylidene fluoride)‐co‐trifluoroethylene] Membranes Obtained by Isothermal Crystallization from Solution
Authors: Ferreira Armando , Silva Jaime , Sencadas Vitor , Ribelles José Luis Gómez , Lanceros‐Méndez S. 
Published: May 2010

AbstractElectroactive macroporous poly[(vinylidene fluoride)‐co‐trifluoroethylene] membranes have been produced by solvent evaporation at room temperature, starting with a diluted solution of the copolymer in dimethylformamide. The pore architecture consists of interconnected spherical pores. This architecture is independent of the membrane thickness. The thickness of the membranes ranges from a few to several hundred µm, using spin coating and evaporation in static conditions, respectively. The pore structure is explained by a spinodal decomposition of the liquid/liquid phase separation and crystallization in the copolymer‐rich phase.magnified image
Hollow Poly(3‐hydroxybutyrate) Fibers Produced by Melt Spinning
Authors: Hinüber Claudia , Häussler Liane , Vogel Roland , Brünig Harald , Werner Carsten 
Published: May 2010

AbstractNative and nucleated PHB has been melt‐spun and the properties of the resulting fibers have been investigated. Biocompatible nucleating agents such as HAP and THY were compared to BN as a reference material. DSC was used to investigate the non‐isothermal crystallization kinetics as a function of processing temperature and cooling rate. It was found that particularly the choice of process temperature can ensure sufficient primary crystallization of native PHB: heating not higher than 10–15 K above the melting temperature induced a favorable crystallization behavior of native PHB. Thus, melt spinning at low process temperatures without additives was demonstrated to be the key to the formation of well‐defined hollow PHB fibers.magnified image
Hydrolytic Depolymerization of PET in a Microwave Reactor
Authors: Siddiqui Mohammad Nahid , Achilias Dimitris S. , Redhwi Halim Hamid , Bikiaris Dimitris N. , Katsogiannis Konstantinos–Alexandros G. , Karayannidis George P. 
Published: May 2010

AbstractRecycling of PET was examined using hydrolytic depolymerization in an alkaline solution under microwave irradiation. The reaction was carried out in a sealed microwave reactor in which the pressure and temperature were controlled and recorded. The main products were the monomers TPA and EG. The effect of reaction temperature, time, amount of PET and alkaline concentration on the degree of PET depolymerization and TPA recovery was investigated. Microwave irradiation was found to reduce the time needed to achieve a specific degradation of PET significantly, with almost complete depolymerization occurring in 30 min at 180 °C and only 46 W of microwave power. Using a phase transfer catalyst (TOMAB) resulted in the same amount of unreacted PET but at significantly lower depolymerization temperatures.magnified image
Intracellular Protein Delivery Systems Formed by Noncovalent Bonding Interactions between Amphipathic Peptide Carriers and Protein Cargos
Authors: Lo Seong Loong , Wang Shu 
Published: May 2010

AbstractSuccessful molecular therapy using protein‐based therapeutic agents for intracellular targets depends on the development of efficient and safe protein delivery systems that are able to overcome the problem of poor permeability of cell membrane to proteins. Here, we summarize recent studies elucidating how one particular class of peptide‐based carriers, amphipathic peptide, has been designed and utilized for intracellular protein delivery in a simple yet effective manner. The unique feature of these delivery systems lies in the noncovalent binding of amphipathic peptides to protein cargos, mainly through hydrophobic interactions. At least five different types of amphipathic peptides have been developed and demonstrated to be able to deliver various biologically active proteins into a variety of cell types without the use of chemical conjugation. In view of their efficiency and presumably low toxicity, we anticipate that amphipathic peptides will continue to be developed as powerful carriers for intracellular delivery of protein therapeutics.magnified image
Ultrafast Responsive Poly‐ (N‐isopropylacrylamide) Gel Produced by Cryostructuring of Self‐crosslinkable Polymer Microgels
Authors: Kirsebom Harald , Mattiasson Bo , Galaev Igor Yu. 
Published: May 2010

AbstractA macroporous material composed of closely aggregated particles was prepared by cryo‐structuration of N‐isopropylacrylamide‐co‐N‐hydroxymethylacrylamide (NIPA‐co‐HMAm) particle suspensions. The formed structure was maintained by the formation of covalent bonds through self‐crosslinking between the particles while the system was in a semi‐frozen state thus avoiding the need to freeze‐dry the sample. This resulted in macroporous structure composed of closely aggregated thermoresponsive particles which exhibit an ultrafast temperature response. The response rate can be attributed both to the macroporous structure as well as the fast responsive properties of the individual particles.magnified image
Seeded Growth and Solvent‐Induced Fragmentation of Fiberlike Polyferrocenylsilane–Polyisoprene Block Copolymer Micelles
Authors: Qian Jieshu , Guerin Gerald , Cambridge Graeme , Manners Ian , Winnik Mitchell A. 
Published: May 2010

AbstractAddition of a concentrated solution of PI1000–PFS50 dissolved in THF to a solution of PI1000–PFS50 seed micelles in decane led to the formation of uniform elongated fiberlike micelles with a narrow length distribution. When additional THF (>10 vol.‐%) was added to the micelles, the micelle length decreased and the contour‐length distribution broadened. This effect was shown to be inconsistent with a transition to an equilibrium, in which individual polymer molecules dissociated from and added to existing micelles. Rather, it appears that the polar solvent induced fragmentation of the fiberlike micelles.magnified image
Fiberlike Micelles Formed by Living Epitaxial Growth from Blends of Polyferrocenylsilane Block Copolymers
Authors: Cambridge Graeme , Guerin Gerald , Manners Ian , Winnik Mitchell A. 
Published: May 2010

AbstractPoly(ferrocenyldimethylsilane) (PFS) block copolymers form fiberlike micelles by a seeded growth process. This paper describes the effect of adding similar amounts of PFS block copolymers, PFS–PDMS and PFS–PI, to a common micelle seed. The lengths of the micelles obtained were strongly influenced by the degree of polymerization of the corona‐forming blocks. The change in length was due to a change in the number of polymer molecules per unit length of the micelle.
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