bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative study between tissue‐engineered periosteum and structural allograft in rabbit critical‐sized radial defect model
Authors: Zhao Lin , Zhao Junli , Wang Shuanke , Wang Junsheng , Liu Jia 
Published: February 2011

AbstractThe purpose of this study was to compare the efficacy of tissue‐engineered periosteum (TEP) to allgeneic bone in repairing segmental bone defect. TEP was fabricated with osteoinduced rabbit bone marrow mesenchymal stem cells (MSCs) and porcine small intestinal submucosa (SIS). Allogrfats were cryopreserved radial segments of New Zealand Rabbits. Forty‐eight radial critical‐sized defects (CSD) were bilaterally produced in 24 rabbits. The defects were divided into three groups, group A, TEP implantation, group B, SIS implantation, and group C allograft. Bone defect reconstruction was kinetically analyzed at 4, 8, and 12 weeks by radiographic and histological scoring system. In group A, bone defects were radiographically and histologically healed with mature cortex and marrow cavity by 12 weeks, while none of the defects healed in group B. Group C showed a slow process of creeping substitution with lymphocyte infiltration. Statistical comparison confirmed that group A had a more efficient and rapid bone defect reparation as well as remodelling than Group B and C. In conclusion, TEP is superior to structural allograft in reconstruction of allogenic segmental bone defect. Pure SIS cannot guide bone regeneration in this rabbit model. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Microstructure and drug‐release studies of sirolimus‐containing poly(lactide‐co‐glycolide) films
Authors: Ro Andrew J. , Falotico Robert , Davé Vipul 
Published: February 2011

AbstractSirolimus‐containing poly(lactide‐co‐glycolide) (PLGA) films were prepared by solution casting and removing the residual solvent, 1,4‐dioxane, by liquid and supercritical carbon dioxide (CO2) extraction. The effect of lactide:glycolide ratio, stereochemistry of PLGA, and extraction condition (i.e., temperature and pressure) on the polymer and drug morphologies was studied using wide‐angle X‐ray scattering and differential scanning calorimetry. The polymer and drug crystallinity increased after liquid and supercritical CO2extraction, and the level of drug crystallinity within the film depended on the extraction conditions. Generally, higher levels of drug crystallinity were observed in the films with amorphous polymer matrices, and the drug crystallinity increased with temperature and pressure of the extraction conditions.In vitrodrug elution from these films was studied using a USP 4 apparatus. Polymer crystallinity was found to be the determining factor for drug release, whereby films with higher polymer crystallinity eluted less drug compared to films with amorphous polymer matrices. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Dysregulation of monocytic cytokine secretion by endodontic sealers
Authors: Brackett Martha Goël , Lewis Jill B. , Messer Regina L. W. , Lei Li , Lockwood Petra E. , Wataha John C. 
Published: February 2011

AbstractRecent studies have reported that sealers may alter the secretion of specific cytokines from THP1 monocytic cells in vitro. In this study, a cytokine array was used to determine if endodontic sealers changed secretion of 42 cytokines. White mineral trioxide aggregate (WMTA), MTA preparation (CS), AH‐Plus (AHP), and Pulp Canal Sealer (PCS) were mixed, allowed to set for 72 h, then “aged” in buffered‐saline for 12 weeks. Aged specimens were placed in direct contact with THP1 for 72 h and their cytotoxicity (MTT assay) was assessed. Materials that were not severely toxic were then exposed to THP1 with or without lipolysaccharide (LPS), and the culture medium was assayed for cytokine secretion. Secretion of cytokines was quantified using infrared scanning (Odyssey®); replicate pairs were averaged. PCS severely suppressed MTT activity and was not assessed for its influence on cytokine secretion. WMTA, CS, and AHP induced a broad‐based increase in cytokine secretion (>20% vs. Teflon controls), but AHP induced the greatest increase (>100% in 17 of 42 cytokines). The effects of the sealers on LPS‐activated THP1 were biphasic, with some increases and decreases cytokine secretion of >20%, but few larger effects. This work shows endodontic sealers may alter the secretion of a broad cross section of cytokines from monocytic cells. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
In situ formation of silver nanoparticles in photocrosslinking polymers
Authors: Cheng Ya‐Jun , Zeiger Diana N. , Howarter John A. , Zhang Xinran , Lin Nancy J. , Antonucci Joseph M. , Lin‐Gibson Sheng 
Published: February 2011

AbstractNanocomposites of cross‐linked methacrylate polymers with silver nanoparticles have been synthesized by coupling photoinitiated free radical polymerization of dimethacrylates with in situ silver ion reduction. A polymerizable methacrylate bearing a secondary amino functional group was used to increase the solubility of the silver salt in the hydrophobic resin system. Fourier transform infrared spectroscopy (FTIR) revealed that the silver ion reduction had no significant effect on the degree of vinyl conversion of the methacrylate. X‐ray photoelectron spectroscopy (XPS) measurements showed an increased silver concentration at the composite surface compared to the expected concentration based on the total amount of silver salt added. Furthermore, the surface silver concentration leveled off when the silver salt mass fractions were 0.08% or greater. Composites with low concentrations of silver salt (< 0.08% by mass) exhibited comparable mechanical properties to those containing no silver. Transmission electron microscopy (TEM) confirmed that the silver nanoparticles formed within the polymer matrix were nanocrystalline in nature and primarily ≈ 3 nm in diameter, with some large particle aggregates. Composites containing silver nanoparticles were shown to reduce bacterial colonization with as little as 0.03% (by mass) silver salt, while additional amounts of silver salt did not further decrease their surface colonization. With a substantial effect on bacterial growth and minimal effects on mechanical properties, the in situ formation of silver nanoparticles within methacrylate materials is a promising technique for synthesizing antibacterial nanocomposites for biomedical applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
In vitro assessment of strength, fatigue durability, and disassembly of Ti6Al4V and CoCrMo necks in modular total hip replacements
Authors: Nganbe Michel , Khan Usman , Louati Hakim , Speirs Andrew , Beaulé Paul E. 
Published: February 2011

AbstractModularity in total hip replacement offers advantages with regard to biomechanical adjustments and leg lengths. Recently, modular femoral necks were introduced as an added advantage to head modularity permitting further adjustments in femoral version as well as offset and ease of revision. Currently, most necks are made of Ti6Al4V for which cases of in vivo fractures and inseparable neck‐stem junctions have been reported. Therefore, we investigated CoCrMo head–Ti6Al4V stem hip replacements with necks made of CoCrMo as an alternative to Ti6Al4V. We compared the two materials with respect to (1) compressive load bearing capacity; (2) fatigue durability; and (3) component distraction. We performed in vitro fatigue‐pull‐off, microscopy, fatigue durability and compression investigations. The CoCrMo neck showed a load bearing capacity of 18 kN, 38% higher than 13 kN for the Ti6Al4V neck. A fatigue load of 11.2 kN for 1 million cycle failure was achieved with CoCrMo translating into nearly 1000 times longer fatigue life compared to Ti6Al4V necks. The neck‐stem distraction force showed large statistical variation and was similar for both neck materials. Overall, the results suggest a superiority of CoCrMo over Ti6Al4V as neck material with regard to mechanical behavior. However, the corrosion behavior was not appropriately assessed and necessitates additional investigations. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
A pH‐sensitive chitosan‐tripolyphosphate hydrogel beads for controlled glipizide delivery
Authors: Sun Ping , Li Ping , Li Yu‐Min , Wei Qin , Tian Lin‐Hong 
Published: February 2011

AbstractA chitosan(CS)‐tripolyphosphate (TPP) hydrogel bead was prepared by the ionic gelation method for the controlled delivery of glipizide. The structure and surface morphology of the beads were characterized by FT‐IR and SEM, separately. Factors influencing the swelling behavior of the hydrogel beads were also investigated, such as CS concentration (X1), TPP concentration (X2), the weight ratio of drug to polymer (X3), crosslinking time (X4), and the volume ratio of CS to TPP (X5). In addition, the swelling property and the delivery behavior of the hydrogel bead was studied as well. With decreasing of pH value, the swelling ratio of the bead was increasing. The swelling ratio of hydrogel bead at pH 1.5 was relatively high, while this value was low at pH 6.8. The amount of glipizide released from the hydrogel bead at pH 1.5 was about 90%, while this value approached 36% at pH 6.8. The results clearly suggested that the CS‐TPP hydrogel beads were used as a pH‐sensitive controlled release system for the delivery of glipizide. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
DLK1 is a novel regulator of bone mass that mediates estrogen deficiency–induced bone loss in mice
Authors: Abdallah Basem M , Ditzel Nicholas , Mahmood Amer , Isa Adiba , Traustadottir Gunnhildur A , Schilling Arndt F , Ruiz-Hidalgo María-José , Laborda Jorge , Amling Michael , Kassem Moustapha 
Published: February 2011

Abstract
Delta-like 1/fetal antigen 1 (DLK1/FA-1) is a transmembrane protein belonging to the Notch/Delta family that acts as a membrane-associated or a soluble protein to regulate regeneration of a number of adult tissues. Here we examined the role of DLK1/FA-1 in bone biology using osteoblast-specific Dlk1-overexpressing mice (Col1-Dlk1). Col1-Dlk1 mice displayed growth retardation and significantly reduced total body weight and bone mineral density (BMD). Micro–computed tomographis (µCT) scanning revealed a reduced trabecular and cortical bone volume fraction. Tissue-level histomorphometric analysis demonstrated decreased bone-formation rate and enhanced bone resorption in Col1-Dlk1 mice compared with wild-type mice. At a cellular level, Dlk1 markedly reduced the total number of bone marrow (BM)–derived colony-forming units fibroblasts (CFU-Fs), as well as their osteogenic capacity. In a number of in vitro culture systems, Dlk1 stimulated osteoclastogenesis indirectly through osteoblast-dependent increased production of proinflammatory bone-resorbing cytokines (eg, Il7, Tnfa, and Ccl3). We found that ovariectomy (ovx)–induced bone loss was associated with increased production of Dlk1 in the bone marrow by activated T cells. Interestingly, Dlk1−/− mice were significantly protected from ovx-induced bone loss compared with wild-type mice. Thus we identified Dlk1 as a novel regulator of bone mass that functions to inhibit bone formation and to stimulate bone resorption. Increasing DLK1 production by T cells under estrogen deficiency suggests its possible use as a therapeutic target for preventing postmenopausal bone loss. © 2011 American Society for Bone and Mineral Research.
Composition‐induced structural transitions in mixed Lennard‐Jones clusters: Global reparametrization and optimization
Authors: Dieterich Johannes M. , Hartke Bernd 
Published: February 2011

AbstractAs extended benchmarks to global cluster structure optimization methods, we provide a first systematic point of entry into the world of strongly mixed rare gas clusters. A new set of generalized Lennard‐Jones pair potentials is generated for this purpose, by fitting them to high‐end ab initio reference data. Employing these potentials in our genetic algorithm‐based global structure optimization framework, we examined various systems from binary to quinary mixtures of atom types. A central result from this study is that the famous fcc structure for 38 atoms can survive for certain binary mixtures but appears to be prone to collapsing into the dominating icosahedral structure, which we observed upon introduction of one single atom of a ternary type. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Theoretical investigation of novel carbazole‐fluorene based D‐π‐A conjugated organic dyes as dye‐sensitizer in dye‐sensitized solar cells (DSCs)
Authors: Yakhanthip Thanisorn , Jungsuttiwong Siriporn , Namuangruk Supawadee , Kungwan Nawee , Promarak Vinich , Sudyoadsuk Taweesak , Kochpradist Palita 
Published: February 2011

AbstractThe ground state structure and frontier molecular orbital of newly synthesized carbazole‐fluorene based D‐π‐A organic dyes, CFP1A, CFP2A, CFP1CA, and CFP2CA, were theoretically investigated using density functional theory (DFT) at B3LYP/6‐31G(d,p) level. These dye molecules have been constructed based on carbazole‐fluorene as the electron‐donating moiety while introducing benzene units as π‐spacer connected to different anchor groups, such as acrylic acid and cyanoacrylic acid, as acceptors. The electronic vertical excitation energies and absorption wavelength were carried out using time‐dependent DFT (TD‐DFT). Furthermore, the adsorptions of phenylacrylic acid and phenylcyanoacrylic acid on the TiO2 anatase (101) surface were carried out by means of quantum‐chemical periodic calculations employing periodic PBE functional with DNP basis set. The results promise that anchor dyes with strong withdrawing CN group have easier injected electron to the conduction band of semiconductor implying that CFP1CA and CFP2CA show better performance among four dyes. Additionally, the intramolecular charge transfers (ICT) from electron donor group to anchoring group of CFP1CA and CFP2CA have shown better performance. The calculated results provide the efficiency trend of our new dyes as CFP1CA ≈ CFP2CA > CFP1A ≈ CFP2A which are excellently agree with experimental observation. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Extensive theoretical study on electronically excited states and predissociation mechanisms of sulfur monoxide including spin–orbit coupling
Authors: Yu Le , Bian Wensheng 
Published: February 2011

AbstractThe potential energy curves of the 69 Ω states generated from the 24 Λ–S states of sulfur monoxide are calculated for the first time using the internally contracted multireference configuration interaction method with the Davidson correction and the entirely uncontracted aug‐cc‐pV5Z basis set. Spin–orbit coupling is taken into account by the state interaction approach with the full Breit–Pauli Hamiltonian. Very good agreement is achieved between our computed spectroscopic properties and the available experimental data. The transition properties of the B3Σ−–X3Σ− and (4)1–X0+ transitions are predicted, and our computed Franck–Condon factors and radiative lifetimes match the experimental results very well. The predissociation mechanisms are investigated, and various new predissociation channels are located. We present a new interpretation on the breaking‐off of the rotational levels of the B3Σ− lower vibrational states observed in experiment, and propose that the predissociation is induced by the Coriolis coupling between the B3Σ− rovibrational levels and the A3Π state. Our calculations indicate that, at ν′ = 9, the B3Σ− state predissociates via the C3Π state; around ν′ = 14, three spin‐orbit‐induced predissociation pathways via (1)5Σ+, (2)5Π, and e1Π would be open; around ν′ = 17, the pathways via (2)1Σ+, (2)3Σ+ and (2)5Σ+ would contribute. These satisfactorily explain the experimental results about the diffuseness of the B3Σ− bands. Furthermore, various predissociation pathways of the C′3Π state are predicted, through which the C′3Π state could predissociate rapidly. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
The through‐space transmission of 77Se — 77Se coupling constants
Authors: Contreras R. H. , Gavarini H. O. , Natiello M. A. 
Published: February 2011

AbstractThe IPPP‐INDO method is applied to study different interactions as well as transmission mechanisms of 77Se — 77Se coupling constants in cis‐ and trans‐1,2‐bis(methylseleno)ethene. Preferential conformations were determined using a modified version of the PCILO‐CNDO method. The preferential conformation of the cis compound is such that nonbonding electron pairs of both Se atoms overlap to some extent. In this conformation a large and positive through‐space transmission of the Fermi contact term of the 77Se — 77Se coupling takes place, which strongly depends on the Se — Se distances. The similarity between this coupling and others involving different nuclei is discussed. The total calculated coupling is in fair agreement with experimental values for similar compounds. The 77Se — 77Se coupling in the trans‐compound is largely dominated by the orbital interaction, which is mainly transmitted through the vinyl π‐electron system.
Screening for and prevalence of HIV and Hepatitis C among an outpatient urban sample of people with serious mental illness and co‐occurring substance abuse
Authors: Himelhoch Seth , Goldberg Richard , Calmes Christine , Medoff Deborah , Slade, Eric , Dixon Lisa , Gallucci Gerard , Rosenberg Stanley 
Published: February 2011

AbstractBackground: To assess rates of screening and testing of HIV and HCV among those with serious mental illness and co‐occurring substance use disorders.Methods: One hundred fifty‐three people with serious mental illness and co‐occurring substance use disorders completed measures and were screened for HIV and HCV.Results: Six percent were HIV positive and 25% were HCV positive. Almost a quarter reported a history of injection drug use and 86% reported a history of unprotected sexual encounters. Compared to those without a diagnosis of Hepatitis C, those diagnosed with Hepatitis C were significantly more likely to have a sexually transmitted infection, (p=0.01), have a lifetime history of injection drug use, (p<0.001), and a lifetime history of sniffing drugs, (p=0.01).Conclusions: Given the high levels of infection of HIV and HCV and high levels of transmission risk factors efforts to improve screening and provide risk reduction counseling are warranted. © 2011 Wiley Periodicals, Inc.
Prevention service system transformation using Communities That Care
Authors: Brown Eric C. , Hawkins J. David , Arthur Michael W. , Briney John S. , Fagan Abigail A. 
Published: February 2011

AbstractThis study examines prevention system transformation as part of a community‐randomized controlled trial of Communities That Care (CTC). Using data from surveys of community leaders, we examine differences between CTC and control communities 4.5 years after CTC implementation. Significantly higher levels of adopting a science‐based approach to prevention observed in CTC communities compared with controls in 2004 were maintained in 2007. Leaders in CTC communities expressed a willingness to contribute significantly more funds to prevention than did leaders in control communities in 2007. Significant differences in levels of community collaboration observed in 2004 were not maintained in 2007. Leaders in CTC communities with high poverty rates and large minority student populations reported higher levels of community norms against drug use and greater use of the social development strategy, respectively, than did leaders in control communities with similar characteristics. © 2011 Wiley Periodicals, Inc.
Evidence of specific characteristics and osteogenic potentiality in bone cells from tibia
Authors: Manferdini Cristina , Gabusi Elena , Grassi Francesco , Piacentini Anna , Cattini Luca , Zini Nicoletta , Filardo Giuseppe , Facchini Andrea , Lisignoli Gina 
Published: February 2011

AbstractHuman bone cells used for in vitro studies are mainly derived from bone marrow (BM) or trabecular bone (TB). There are no specific markers or procedures for isolation and growth of these cells. To validate the potentiality of these cells, we isolated human mesenchymal stromal cells (MSCs) and osteoblasts (OBs) from the tibial plateau of the same subject, grown in two different media (α‐MEM and DMEM/F12) and analyzed for cell growth, proliferation, phenotype and osteogenic potential. We found that OBs grew well in both media tested, but MSCs were able to grow only in α‐MEM medium. OBs in DMEM/F12 showed reduced proliferation capability and expressed a low level of alkaline phosphatase (AP), RUNX‐2, osteocalcin (OC), bone sialoprotein (BSP), collagen type I (Col.I) compared with OBs in α‐MEM but high level of collagen type XV (Col.XV). Compared with MSCs in α‐MEM, OBs have an increased ability to proliferate and express more OC and BSP at molecular level but less AP, RUNX‐2 and Col.I than MSCs. Time‐course experiments to analyze the osteogenic potential of these cells showed that OBs were more efficient than MSCs. However, these cells obtained from tibial plateau showed a different trend of AP, OC and Col.I osteogenic markers compared to control MSCs from the iliac crest. This study shows that bone‐adherent OBs grown in α‐MEM medium are more efficient for osteogenic differentiation than BM MSCs and contribute to defining their phenotypic and functional characteristics, so providing a rationale for their use in bone tissue engineering or therapeutic purposes. J. Cell. Physiol. 226: 2675–2682, 2011. © 2011 Wiley‐Liss, Inc.
Macrophage‐induced expression and release of matrix metalloproteinase 1 and 3 by human preadipocytes is mediated by IL‐1β via activation of MAPK signaling
Authors: Gao Dan , Bing Chen 
Published: February 2011

AbstractObesity is associated with a chronic low‐grade inflammation and increased macrophage infiltration in adipose tissue. Matrix metalloproteinases (MMPs) are involved in adipose tissue remodeling and inflammatory responses in obesity. This study investigated whether macrophage‐derived factors modulate expression and secretion of MMP1 and MMP3 in human preadipocytes. The potential mediators and signaling pathways were also explored. MMP1 and MMP3 were primarily expressed and secreted by preadipocytes and dramatically reduced post‐differentiation. Preadipocytes were incubated with RPMI 1640 medium (control) or THP‐1 macrophage‐conditioned (MC) medium (25% and 100%) for 24 h. MC medium markedly increased mRNA levels of MMP1 (up to 122‐fold) and MMP3 (up to 59‐fold), as well as protein release of MMP1 (up to 378‐fold) and MMP3 (up to 10‐fold) in a dose‐dependent manner. Treatment with IL‐1β or TNFα, the major products of macrophages, also induced MMP1 and MMP3 secretion by preadipocytes. Neutralizing IL‐1β abolished the induction of MMP1 and MMP3 in preadipocytes by MC medium while the effects of TNFα neutralization were modest. Furthermore, MC medium or IL‐1β led to the phosphorylation of p38, ERK and JNK MAPKs. Inhibition of p38, ERK and JNK reversed the stimulatory effects of MC or IL‐1β on MMP1 and MMP3 production. MC medium and IL‐1β also activated NF‐κB p65 whereas reduced IκBα protein expression in preadipocytes. These results suggest that macrophage accumulation in adipose tissue has a central role in stimulating MMP1 and MMP3 production by preadipocytes, and this is partially mediated by IL‐1β via activation of the MAPK and NF‐κB signaling pathways. J. Cell. Physiol. 226: 2869–2880, 2011. © 2011 Wiley‐Liss, Inc.