bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental evaluation of rectangular reinforced concrete column behaviour under biaxial cyclic loading
Authors: Rodrigues Hugo , Arêde António , Varum Humberto , Costa Aníbal G. 
Published: May 2012

SUMMARYThe cyclic behaviour of reinforced concrete columns has been the subject of many experimental studies in recent years. However, most of these studies have focused on the unidirectional loading of columns with square cross‐sections under constant axial loading conditions. In the present study, four types of full‐scale quadrangular building columns were tested under different types of loading, including uniaxial and biaxial loading conditions. The first two specimens of each column type were independently cyclically tested in the strong and weak directions. Bidirectional tests using different loading paths were performed on the other column specimens. All columns were tested under constant axial loading conditions. In this paper, the experimental results are presented, and the global behaviour of tested columns is discussed, particularly focusing on the stiffness and strength degradation because of the increasing cyclic demand. Finally, the deformation‐based performance limits proposed in Part 3 of Eurocode 8 were calculated and compared with the experimental results. Copyright © 2012 John Wiley & Sons, Ltd.
Damping identification of a full‐scale passively controlled five‐story steel building structure
Authors: Ji Xiaodong , Hikino Tsuyoshi , Kasai Kazuhiko , Nakashima Masayoshi 
Published: May 2012

SUMMARYA series of large‐scale dynamic tests was conducted on a passively controlled five‐story steel building on the E‐Defense shaking table facility in Japan to accumulate knowledge of realistic seismic behavior of passively controlled structures. The specimen was tested by repeatedly inserting and replacing each of four damper types, that is, the buckling restrained braces, viscous dampers, oil dampers, and viscoelastic dampers. Finally, the bare steel moment frame was tested after removing all dampers. A variety of excitations was applied to the specimen, including white noise, various levels of seismic motion, and shaker excitation. System identification was implemented to extract dynamic properties of the specimen from the recorded floor acceleration data. Damping characteristics of the specimen were identified. In addition, simplified estimations of the supplemental damping ratios provided by added dampers were presented to provide insight into understanding the damping characteristics of the specimen. It is shown that damping ratios for the specimen equipped with velocity‐dependent dampers decreased obviously with the increasing order of modes, exhibiting frequency dependency. Damping ratios for the specimen equipped with oil and viscoelastic dampers remained constant regardless of vibration amplitudes, whereas those for the specimen equipped with viscous dampers increased obviously with an increase in vibration amplitudes because of the viscosity nonlinearity of the dampers. In very small‐amplitude vibrations, viscous and oil dampers provided much lower supplemental damping than the standard, whereas viscoelastic dampers could be very efficient. Copyright © 2012 John Wiley & Sons, Ltd.
A formally second‐order cell centred scheme for convection–diffusion equations on general grids
Authors: Piar L. , Babik F. , Herbin R. , Latché J.‐C. 
Published: May 2012

SUMMARYWe propose, in this paper, a finite volume scheme to compute the solution of the convection–diffusion equation on unstructured and possibly non‐conforming grids. The diffusive fluxes are approximated using the recently published SUSHI scheme in its cell centred version, that reaches a second‐order spatial convergence rate for the Laplace equation on any unstructured two‐dimensional/three‐dimensional grids. As in the MUSCL method, the numerical convective fluxes are built with a prediction‐limitation process, which ensures that the discrete maximum principle is satisfied for pure convection problems. The limitation does not involve any geometrical reconstruction, thus allowing the use of completely general grids, in any space dimension. Copyright © 2012 John Wiley & Sons, Ltd.
Spatial interpolation of sub‐daily air temperatures for snow and hydrologic applications in mesoscale Alpine catchments
Authors: Jabot E. , Zin I. , Lebel T. , Gautheron A. , Obled C. 
Published: May 2012

AbstractAir temperature represents a key parameter for snow hydrology, as it controls the precipitation phase, as well as snow accumulation and snowmelt. Hydrological modelling in mountain regions like the Alps needs high‐resolution temperature fields as input, preferably at sub‐daily time steps. The estimation of such temperature fields is challenging due to the spatio‐temporal variability of environmental lapse rates (i.e. the decreasing of temperature with altitude) associated to complex topography. In this study, 10 years (2000–2009) of data from about 200 temperature stations were interpolated at 0, 6, 12 and 18 h Universal Time Coordinated (UTC) over a 1‐km resolution grid covering a window of 71 500 km2in the Northern French Alps. Three different kriging methods were tested. Kriging with elevation as external drift gave the best results in terms of mean absolute error, root mean square error and kriging standard deviation. Adding potential solar radiation as an additional external variable did not improve significantly the interpolation results. Prediction errors showed dependence on elevation and season, as well as on the time of interpolation, with globally better results in summer and daytime than in winter and night‐time. Despite some shortcomings that are discussed in the paper, the interpolated temperature fields look promising for further snowmelt and snow cover dynamics modelling studies. Copyright © 2012 John Wiley & Sons, Ltd.
Variants at chromosome 20 (ASIP locus) and melanoma risk
Authors: Maccioni Livia , Rachakonda P. Sivaramakrishna , Scherer Dominique , Bermejo Justo Lorenzo , Planelles Dolores , Requena Celia , Hemminki Kari , Nagore Eduardo , Kumar Rajiv 
Published: May 2012

AbstractAgouti signaling protein (ASIP) locus on chromosome 20q11 is implicated, as shown by genome‐wide association studies, in phenotype variation and melanoma risk. We genotyped 837 melanoma cases and 1,154 controls for 21 single nucleotide polymorphisms (SNPs) informative for 495 polymorphisms at the locus. Our data showed an increased risk of melanoma (odds ratio [OR] 1.27, 95% confidence interval [95% CI] 1.03–1.57) in carriers of the rs4911414 variant, located 120 kb upstream of ASIP. The main effect of rs4911414, as reported previously, was in tandem with a 10 kb adjacent polymorphism rs1015362; two constituted risk‐associated haplotype/diplotype. Except for rs1015363, none of the 12 tagging SNPs, genotyped to cover 239.9 kb region with polymorphisms linked to rs4911414 and rs1015362, were associated with melanoma. Our data confirmed a previous association of melanoma risk (OR 1.82, 95% CI 1.37–2.41) with rs4911442, located in intron 5 of the nuclear receptor coactivator 6 (NCOA6) gene. The rs910871, one of the six variants, genotyped to cover NCOA6, showed an association with melanoma risk (OR 1.33, 95% CI 1.04–1.70). Both, rs4911442 and rs910871 were in moderate linkage with a, previously reported, risk‐associated rs910873 polymorphism. A haplotype from the variants within NCOA6 showed an association with risk of melanoma (OR 1.49, 95% CI 1.17–1.88). Interaction between risk‐associated polymorphisms and previously genotyped melanocortin receptor 1 (MC1R) variants, in our study, was not statistically significant. Nevertheless, the carriers of the variant alleles over the background of MC1R variants were at a higher risk than the carriers not enriched for MC1R variants. Our data confirmed the association of different variants at chromosome 20q11 with melanoma risk.
Chemometric evaluation of physicochemical properties of carbonated‐apatitic preparations by Fourier transform infrared spectroscopy
Authors: Otsuka Makoto , Papangkorn Kongnara , Baig Arif A. , Higuchi William I. 
Published: May 2012

AbstractThe purpose of this study was to develop a simple and quick method of evaluating the physicochemical properties of carbonated apatite preparations (CAP) as an index of the bioaffinity of implantable materials based on Fourier‐transformed‐infrared (IR) spectra by chemometrics. The wet‐synthesized CAPs contained various levels of carbonate content (CO3), and were analyzed microstrain parameter (MS), crystallite size parameter (CP), specific surface area (Sw), CO3, and solubility parameter (pKHAP) using by X‐ray powder diffraction, nitrogen gas adsorption, IR, and UV absorption. The IR spectral results of CAPs suggested that the peak intensities of CAP reflected the physicochemical properties of the samples. The IR data sets were calculated to obtain calibration models evaluating the physicochemical properties of CAPs by a partial least squares regression analysis (PLS). As validation of the calibration model, physicochemical properties of CAP could be evaluated based on validation IR data sets of independent samples, and those values had sufficient accuracy. The regression vector of each calibration model suggested that the physicochemical properties of CAP, such as CO3, Sw, MS, CP, and pKHAP, were affected by phosphate, hydroxyl, and carbonate groups. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Degradable amorphous scaffolds with enhanced mechanical properties and homogeneous cell distribution produced by a three‐dimensional fiber deposition method
Authors: Sun Yang , Finne‐Wistrand Anna , Albertsson Ann‐Christine , Xing Zhe , Mustafa Kamal , Hendrikson Wim J. , Grijpma Dirk W. , Moroni Lorenzo 
Published: May 2012

AbstractThe mechanical properties of amorphous, degradable, and highly porous poly(lactide‐co‐caprolactone) structures have been improved by using a 3D fiber deposition (3DF) method. Two designs of 3DF scaffolds, with 45° and 90° layer rotation, were printed and compared with scaffolds produced by a salt‐leaching method. The scaffolds had a porosity range from 64% to 82% and a high interconnectivity, measured by micro‐computer tomography. The 3DF scaffolds had 8–9 times higher compressive stiffness and 3–5 times higher tensile stiffness than the salt‐leached scaffolds. There was a distinct decrease in the molecular weight during printing as a consequence of the high temperature. The chain microstructure was, however, not affected; the glass transition temperature and the decomposition temperature were constant. Human OsteoBlast‐like cells were cultured in vitro and the cell morphology and distribution were observed by scanning electron microscopy and fluorescence microscopy. The cell distribution on the 3DF scaffolds was more homogeneous than the salt‐leached scaffolds, suggesting that 3DF scaffolds are more suitable as porous biomaterials for tissue engineering. These results show that it is possible to design and optimize the properties of amorphous polymer scaffolds. The 3DF method produce amorphous degradable poly(lactide‐co‐caprolactone) that are strong and particularly suitable for cell proliferation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2739–2749, 2012.
Experimental and computational analysis of cellular interactions with nylon‐3‐bearing substrates
Authors: Liu Runhui , Vang Kang Z. , Kreeger Pamela K. , Gellman Samuel H. , Masters Kristyn S. 
Published: May 2012

AbstractThe ability to design biomaterials that interact with biological environments in a predictable manner necessitates an improved understanding of how surface chemistry influences events such as protein adsorption and cell adhesion. In this work, we examined mechanisms governing the interactions between 3T3 fibroblasts and nylon‐3 polymers, which have a protein‐like polyamide backbone and are highly amenable to tuning of chemical and physical properties. Protein adsorption and cell adhesion to a library of nylon‐3 polymers were characterized and analyzed by partial least squares regression. This analysis revealed that specific chemical features of the nylon‐3 polymers correlated with the extent of protein adsorption, which, in turn, correlated with cell adhesion in a serum‐containing environment. In contrast, in a serum‐free environment, cell adhesion could be predicted solely from chemical properties. Enzymatic treatments of 3T3 cells before plating indicated that proteins bound to the cell surface mediated cell‐nylon‐3 polymer interactions under serum‐free conditions, with additional analysis suggesting that cell‐associated fibronectin played a dominant role in adhesion in the absence of serum. The mechanistic insight gained from these studies can be used to inform the design of new polymer structures in addition to providing a basis for continued development of nylon‐3 copolymers for tissue engineering applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2750–2759, 2012.
Influence of multilayer rhBMP‐2 DNA coating on the proliferation and differentiation of MC3T3‐E1 cells seeded on roughed titanium surface
Authors: Jiang Qiao‐Hong , Liu Li , Shen Jian‐Wei , Peel Sean , Yang Guo‐Li , Zhao Shi‐Fang , He Fu‐Ming 
Published: May 2012

AbstractFor bone morphogenetic protein (BMP) gene therapy to be a viable approach for enhancing implant osseointegration clinically, requires the development of efficient nonviral delivery vectors that can coat the implant. This study evaluated a multilayer cationic liposome‐DNA complex (LDc) coating as a delivery vehicle for recombinant human BMP‐2 (rhBMP‐2). Multilayered coatings, comprising hyaluronic acid (HA) and LDc, were fabricated onto titanium using a layer‐by‐layer (LBL) assembly technique. Preosteoblastic MC3T3‐E1 cells were cultured on the roughened titanium surfaces coated with multilayers of HA/LDc, or on uncoated or HA/liposome only surfaces as controls. The amount of rhBMP‐2 secreted by the MC3T3‐E1 cells and the effect of the various surfaces on cell viability, proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OC) secretion, and calcium deposition were evaluated. Messenger RNA levels of OC, ALP, Runx2, and Osx were also investigated. The results demonstrated that rhBMP‐2 protein secreted into culture medium at 3 days was significantly higher than control groups. MC3T3‐E1 cells cultured on the HA/LDc coating displayed significantly higher ALP activity and OC secretion at 7 days and 14 days culture, respectively. MC3T3‐E1 cells cultured on HA/LDc upregulated expression of the osteoblast differentiation markers, especially on days 12 for OC and on days 6 and 12 for ALP and Osx. In conclusion, MC3T3‐E1 cell cultured on the multilayer HA/LDc coating surface can secret rhBMP‐2 protein and the protein levels were effective in inducing early osteogenic differentiation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A: 2766–2774, 2012.
Improved osteoblast compatibility of medical‐grade polyetheretherketone using arc ionplated rutile/anatase titanium dioxide films for spinal implants
Authors: Tsou Hsi‐Kai , Hsieh Ping‐Yen , Chi Meng‐Hui , Chung Chi‐Jen , He Ju‐Liang 
Published: May 2012

AbstractTitanium dioxide (TiO2), known to exhibit good biocompatibility, is applied in this study as a thin film formed onto polyetheretherketone (PEEK) substrate, which has been widely used in spinal interbody fusion cages. For successful deposition, an arc ionplating (AIP) technique was applied to deposit TiO2 at low deposition temperature without damaging PEEK substrate, while providing satisfactory film adhesion. This study systematically investigates the effects of TiO2 thin film phase composition and surface characteristics, controlled by using different target current and substrate bias, on osteoblast compatibility. Experimental results showed that anatase phase (A‐TiO2) and/or rutile phase (R‐TiO2) TiO2 coatings, respectively, can be prepared in appropriate deposition conditions. Overall, the TiO2‐coated PEEK presented better osteoblast compatibility than the bare PEEK material in terms of cell adhesion, cell proliferation, and cell differentiation abilities, as well as osteogenesis performance (as determined by levels of osteopontin, osteocalcin, and calcium content). Surface roughness and hydrophilicity of the AIP‐TiO2 films were found to be responsible for significant osteoblast cell growth. It is also noticeable that the R‐TiO2 exhibited better osteoblast compatibility than the A‐TiO2 due to the presence of negatively charged hydroxyl groups on R‐TiO2 (110) surface in nature. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2787–2792, 2012.
Punch and spindle‐shaped biopsies for collecting oral mucosal tissue for the fabrication of transplantable autologous epithelial cell sheets
Authors: Sasaki Ryo , Yamato Masayuki , Takagi Ryo , Ohki Takashi , Matsumine Hajime , Okano Teruo , Ando Tomohiro 
Published: May 2012

AbstractThe oral mucosa is an easily accessible source of cells. Oral mucosal collection will be an essential surgical procedure for regenerative medicine and cell biological research. However, there is no current report that describes the details of the surgical procedure used for oral mucosal collection. Moreover, the number of cells that can be obtained has not been determined. Two different procedures, the punch biopsy and the spindle‐shaped biopsy, were performed for the fabrication of transplantable autologous epithelial cell sheets. The mean values of the cells collected per square centimeter of tissue using the punch biopsy and the spindle‐shaped biopsy were 76.8 ± 45 × 104 cells/cm2 and 195.7 ± 120 × 104 cells/cm2, respectively. There was no significant difference between the punch biopsy and the spindle‐shaped biopsy. The coefficient of variation of the punch biopsy and the spindle‐shaped biopsy was 58.9% and 69.8%, respectively. This result indicated that both procedures showed variations in the number of collected cells. Although the punch biopsy may be easier and simpler than the spindle‐shaped biopsy, multiple punch biopsies may result in a more complicated procedure, and the spindle‐shaped biopsy may be preferable when a large number of cells is necessary. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2849–2854, 2012.
miR‐301a promotes pancreatic cancer cell proliferation by directly inhibiting bim expression
Authors: Chen Zhen , Chen Lian‐Yu , Dai Hai‐Yan , Wang Peng , Gao Song , Wang Kun 
Published: May 2012

AbstractIt is well known that microRNAs (miRNAs) play an important role in many diseases, including tumorigenesis. However, the mechanisms by which miRNAs regulate pancreatic cancer (PC) development remain poorly understood. In the present study, we assayed expression level of miR‐301a in PC tissues by real‐time PCR, and defined the target gene and biological function by luciferase reporter assay and Western blot analysis. We first verified that the expression level of miR‐301a was significantly increased in PC tissues. Moreover, miR‐301a overexpression promoted PC cell proliferation, whereas its depletion decreased cell proliferation. We further demonstrated that miR‐301a directly targeted 3′‐UTR of Bim gene, and inhibited its protein expression in vitro and in vivo. Importantly, Bim re‐expression reduced PC cell proliferation induced by miR‐301a. These data suggest an important role of miR‐301a in the molecular etiology of PC and implicate the potential application of miR‐301a in PC therapy. J. Cell. Biochem. 113: 3229–3235, 2012. © 2012 Wiley Periodicals, Inc.
Density functional theory study of high‐pressure effect on crystalline 4,4′,6,6′‐tetra(azido)hydrazo‐1,3,5‐triazine
Authors: Wang Fang , Du Hong‐Chen , Liu Hui , Gong Xue‐Dong 
Published: May 2012

AbstractPeriodic density functional theory calculations are performed to study the hydrostatic compression effects on the structure, electronic, and thermodynamic properties of the energetic polyazide 4,4′,6,6′‐tetra(azido)hydrazo‐1,3,5‐triazine (TAHT) in the range of 0−100 GPa. At the ambient pressure, the local density approximation/Ceperley‐Alder exchange‐correlation potential parameterized by Perdew and Zunger relaxed crystal structure compares well with the experimental results. The predicted heat of sublimation is 38.68 kcal/mol, and the evaluated condensed phase of formation (414.04 kcal/mol) approximates to the experimental value. The detonation velocity and detonation pressure for the solid TAHT are calculated to be 7.44 km/s and 23.71 GPa, respectively. When the pressure is exerted less than 35 GPa, the crystal structure and geometric parameters change slightly. However, at 36 GPa, the molecular structure, band structure, and density of states change abnormally because of the azide‐tetrazole transformation that has not been observed in gas phase or polar solvents. The azido group cyclizes to form a five‐membered tetrazole ring that is coplanar with the riazine ring and contributes to a larger conjunction system. As the pressure augments further to 80 GPa, the hydrogen transfer is found and a new covalent bond H2N9 is formed. In the studied pressure range, the band gap decreases generally except for some breaks due to the molecular transformation and drops to nearly zero at 100 GPa, which means the electronic character of the crystal changes toward a metallic system. An analysis of the electronic structure shows that an applied pressure increases the impact sensitivity of TAHT. © 2012 Wiley Periodicals, Inc.
Leukocyte Cell Population Analysis From the Coulter Automatic Blood Cell Analyzer DxH800 to Monitor the Effect of G‐CSF
Authors: Lee Sung‐Eun , Lim Jihyang , Kim Yonggoo , Min Woo‐Sung , Han Kyungja 
Published: May 2012

BackgroundGranulocyte colony‐stimulating factor (G‐CSF) induces the formation of toxic granulation neutrophils (TGNs), which are found in many inflammatory responses. Cell population data (CPD) may be able to clarify the effect of G‐CSF, and potentially help doctors in discriminating the effect of G‐CSF from other inflammatory situations.MethodsTo achieve this, we performed analyses of leukocyte CPD from normal controls and healthy donors that had received G‐CSF for peripheral blood stem cells (PBSCs) mobilization (G‐CSF group).ResultsTwo hundred and seventy‐one subjects were enrolled as normal controls, and 21 subjects were enrolled in the G‐CSF group. Mean volume (MN‐V)‐neutrophils (NE), mean axial light loss (MN‐AL2)‐NE, and all standard deviation (SD) parameters increased significantly, whereas all light scattering parameters, mean median angle light scatter (MN‐MALS)‐NE, mean upper median angle light scatter (MN‐UMALS)‐NE, mean lower median angle light scatter (MN‐LMALS)‐NE, and mean low angle light scatter (MN‐LALS)‐NE reduced significantly in the G‐CSF group. MN‐V‐lymphocytes (LY) from the G‐CSF group showed no significant difference (P = 0.143), whereas MN‐V‐monocytes (MO) were significantly decreased (P < 0.001). Receiver operating characteristic (ROC) curves for the discrimination of the G‐CSF group from normal controls showed excellent sensitivity in SD‐LALS‐NE (at 30.85, sensitivity 95.2%, specificity 76.0%), MN‐AL2‐NE (at 134.5, sensitivity 90.5%, specificity 83.0%), and SD‐AL2‐NE (at 16.4, sensitivity 95.2%, specificity 95.2). Several CPD parameters of lymphocytes and monocytes, as well as neutrophils can be used as markers for determining the effect of G‐CSF.ConclusionOur data show that many CPD of leukocytes can be considered to be useful parameters of the effect of G‐CSF. J. Clin. Lab. Anal. 26:194‐199, 2012. © 2012 Wiley Periodicals, Inc.