bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow analysis for a double suction centrifugal machine in the pump and turbine operation modes
Authors: González José , Fernández Oro Jesús Manuel , Argüelles‐Díaz Katia M. , Santolaria Carlos 
Published: November 2008

AbstractA double suction centrifugal machine has been studied, both experimentally and numerically, operating as a pump and as a turbine. Experimentally, the static performance of the machine working as a pump was obtained. These measurements were compared with equivalent numerical results from a URANS calculation. As a second step, the numerical results have been exploited to get detailed information about the flow in both operating modes (pump and turbine).The main goals of the study are, first, the validation of the numerical procedure proposed and second, the possible turbine operation of the impeller, which could point out a wider working range for the machine. The first aspect is handled by detailed analysis in the pump mode, according to previous experience of the research group. The second objective is obtained by using the numerical model to explore the flow fields obtained, when working in an inverse mode. Therefore, the presented results join the use of a numerical methodology and the turbine mode of operation for a centrifugal impeller, providing insight into the flow characteristics.When working as a pump, the flow at the suction side is characterized by the existence of an inlet tongue, which tends to enforce a uniform flow for the nominal conditions. For the turbine mode, flow patterns in the impeller, volute and suction regions are carefully investigated. The influence of the specific geometrical arrangement is also considered for this operation mode. Copyright © 2008 John Wiley & Sons, Ltd.
Treatment with galantamine and time to nursing home placement in Alzheimer's disease patients with and without cerebrovascular disease
Authors: Feldman Howard H. , Pirttila Tuula , Dartigues Jean François , Everitt Brian , Van Baelen Bart , Schwalen Susanne , Kavanagh Shane 
Published: November 2008

AbstractObjectiveThis study evaluated patient and treatment (galantamine and other acetylcholinesterase inhibitors (AChEIs)) factors associated with the time until nursing home placement (NHP) in patients with Alzheimer's disease (AD) with and without cerebrovascular disease (CVD).MethodsRe‐contact follow‐up study conducted in 2004 of 548 patients who had previously participated in RCTs with galantamine. Time to NHP was analyzed using Kaplan‐Meier estimates and Cox regression analysed factors associated with NHP.ResultsThere were 57% of female subjects and the mean age (SE) was 73.6 (±0.33) years. Within this cohort 78% of patients had AD, and 22% had AD with CVD. Overall, 59% of subjects had a NHP (median 42.4 months 95%CI: 38.0–48.0). The Cox regression model identified higher baseline Disability Assessment in Dementia (DAD) and Mini Mental State Examination (MMSE) scores, diagnosis (AD with CVD vs AD), living with caregiver, country, and treatment duration with galantamine or other AChEIs as factors associated with a reduced risk of institutionalization (p < 0.05). For each year of treatment with galantamine or other AChEI, the risk of being admitted to a nursing home within a given period was reduced by 31% (galantamine) and 29% (other AChEI).ConclusionsLong‐term treatment with galantamine or other AChEIs appears to be associated with a significant delay in the time to NHP in patients with AD and AD with CVD. Further prospective studies are needed to confirm these findings. Copyright © 2008 John Wiley & Sons, Ltd.
Next‐day residual effects of gaboxadol and flurazepam administered at bedtime: a randomized double‐blind study in healthy elderly subjects
Authors: Boyle Julia , Wolford Dennis , Gargano Cynthia , McCrea Jacqueline , Cummings Corinne , Cerchio Kristine , Lines Christopher 
Published: November 2008

AbstractObjectiveTo evaluate the next‐day residual effects of the novel hypnotic, gaboxadol, following bedtime dosing in healthy elderly subjects.MethodsHealthy women (N = 15) and men (N = 10) aged 65–79 years received a single bedtime (22:00 h) dose of gaboxadol 10 mg, flurazepam 30 mg (positive control), and placebo in a randomized, double‐blind, crossover study. Measures of information processing and psychomotor performance (choice reaction time, critical flicker fusion, digit symbol substitution, compensatory tracking, body sway), memory (immediate and delayed word recall), and daytime sleepiness (Multiple Sleep Latency Test), as well as subjective ratings (line analog rating scales, Leeds Sleep Evaluation Questionnaire), were obtained starting at 07:00 h the following morning. Adverse events were recorded.ResultsGaboxadol did not show next‐day impairments versus placebo on any pharmacodynamic measures whereas the positive control, flurazepam, did show impairments versus placebo on most measures. Gaboxadol showed improvements versus placebo on some measures including subjective rating of next‐day alertness/clumsiness on the Leeds Sleep Evaluation Questionnaire. Gaboxadol was generally well‐tolerated; there were no serious adverse experiences and no subjects discontinued due to an adverse experience.ConclusionsA single oral bedtime dose of gaboxadol 10 mg did not have next‐day residual effects in healthy elderly subjects, as measured by a range of pharmacodynamic assessments, in contrast to the clear impairments produced by flurazepam 30 mg. Copyright © 2008 John Wiley & Sons, Ltd.
Immunological responses in C3H/HeJ mice following nose‐only inhalation exposure to different sizes of beryllium metal particles
Authors: Salehi Fariba , Zayed Joseph , Audusseau Séverine , Muller Caroline , Truchon Ginette , Plamondon Philippe , L'Espérance Gilles , Chevalier Gaston , Mazer Bruce 
Published: November 2008

AbstractBeryllium is used in a wide variety of industries. Chronic beryllium disease is the most common occupational disease among workers following exposure to Be. The objective of this study was to determine the immunologic effects of two different particle sizes of Be metal, <2.5 µm (fine Be or Be‐F) and <10 µm (inhalable Be or Be‐I) on C3H/HeJ mice following 3 weeks of nose‐only inhalation exposure at a target concentration of 250 µg m−3. Mice were sacrificed either on day 28 or day 42 (Be‐F group only) after exposure. The mass median aerodynamic diameter obtained in the inhalation chamber was 1.5 ± 0.1 µm for Be‐F and 4.1 ± 0.6 µm for Be‐I. Results showed peri‐bronchial inflammation with early granulomatous changes in exposed mice. The extent of the inflammation appeared more severe for mice sacrificed at day 42. Splenocyte proliferation was higher for mice exposed to fine particles compared with Be‐I and control animals. Flow‐cytometric analysis indicated a significantly greater expression of CD4+, CD8+ and intracellular IFN‐γ expression for both Be particle sizes, particularly for fine particles. Cytokine assays of bronchoalveolar lavage revealed significantly greater levels of IL‐12, TNF‐α and IFN‐γ for mice exposed to fine particles. Our findings suggest that exposure to fine particles may induce more pronounced immunological effects than inhalable particles. Copyright © 2008 John Wiley & Sons, Ltd.
Metabolic significance of bisphenol A‐induced oxidative stress in rat urine measured by liquid chromatography–mass spectrometry
Authors: Cho Sung‐Hee , Choi Man Ho , Kwon Oh Seung , Lee Won‐Yong , Chung Bong Chul 
Published: November 2008

AbstractModified nucleosides are formed by DNA repair as a result of oxidative DNA damage and post‐transcriptionally modified tRNA in cells. In the present study, profiling of 14 nucleoside was investigated in rat urine to evaluate bisphenol A (BPA)‐induced oxidative stress after intraperitoneally injecting rats with 0, 10 or 50 mg kg−1 per day of BPA for four consecutive days. The urinary concentrations of individual nucleosides were measured by liquid chromatography–tandem mass spectrometry combined with column switching on‐line extraction. Increased levels of 5‐hydroxymethyl‐2′‐deoxyuridine (P <0.01 on first, P <0.005 on second, P <0.001 on third and P <0.01 on fourth day) and 8‐hydroxy‐2′‐deoxyguanosine (P <0.005 on second, P <0.001 on third and P <0.001 on fourth day) were found. Also, the patterns of urinary nucleosides in three dosage groups (control, BPA1, BPA2) were significantly different. Statistical significance was observed between BPA1 (5‐hydroxymethyl‐2′‐deoxyuridine, P <0.05; 8‐hydroxy‐2′‐deoxyguanosine, P <0.005) and BPA2 (5‐hydroxymethyl‐2′‐deoxyurindine, P <0.005; 8‐hydroxy‐2′‐deoxyguanosine, P <0.001) during the treatment period. Supervised analysis with partial least‐squares‐discrimination analysis led to discrimination between the three dosage groups. Quantitative alterations showed the metabolic trajectories responsible for physiological responses. The described methods could be used to evaluate and monitor BPA‐induced oxidative stress early after exposure. Copyright © 2008 John Wiley & Sons, Ltd.
Bioinspired superhydrophobic poly(L‐lactic acid) surfaces control bone marrow derived cells adhesion and proliferation
Authors: Alves Natália M. , Shi Jun , Oramas Elena , Santos José L. , Tomás Helena , Mano João F. 
Published: November 2008

AbstractThe aptitude of a cell to adhere, migrate, and differentiate on a compact substrate or scaffold is important in the field of tissue engineering and biomaterials. It is well known that cell behavior can be controlled and guided through the change in micro‐ and nano‐scale topographic features. In this work, we intend to demonstrate that special topographic features that control wettability may also have an important role in the biological performance of biodegradable substrates. Poly(L‐lactic acid) surfaces with superhydrophobic characteristics were produced, based on the so‐called Lotus effect, exhibiting dual micro‐ and nano‐scale roughness. The water contact angle could be higher than 150° and a value of that order could be kept even upon immersion in a simulated body fluid solution for more than 20 days. Such water repellent surfaces were found to prevent adhesion and proliferation of bone marrow derived cells previously isolated from the femurs of 6‐week‐old male Wistar rats, when compared with smoother surfaces prepared by simple solvent casting. Such results demonstrate that these superhydrophobic surfaces may be used to control cell behavior onto biodegradable substrates. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Methods to promote Notch signaling at the biomaterial interface and evaluation in a rafted organ culture model
Authors: Beckstead Benjamin L. , Tung Jason C. , Liang Katharine J. , Tavakkol Zarry , Usui Marcia L. , Olerud John E. , Giachelli Cecilia M. 
Published: November 2008

AbstractThe Notch signaling pathway is a promising target for controlling cell fate choices at the biomaterial‐tissue interface. Building on our previous work in developing Notch‐signaling biomaterials, we evaluated various immobilization schemes for Notch ligands, and their effect on human foreskin keratinocytes. A peptide sequence derived from the Jagged‐1 DSL‐region and immobilized to poly(2‐hydroxyethyl methacrylate) (polyHEMA) showed no bioactivity in relation to the Notch‐CSL pathway. The full‐length Jagged‐1 protein immobilized directly to the polyHEMA surface showed activity in signaling the Notch‐CSL pathway. However, an indirect affinity immobilization approach yielded a stronger signal. Human keratinocytes plated on bound Jagged‐1 showed upregulated involucrin, keratin 10, and loricrin protein expression, with this expression being cell density‐dependent. Utilizing a human foreskin rafted organ culture model as a bridge between in vitro and in vivo studies, Jagged‐1‐modified or control polyHEMA rods were implanted in human foreskin and cultured at the air‐medium interface. Keratinocyte proliferation was suppressed and intermediate‐stage differentiation promoted in Jagged‐1‐modified rods compared with control rods. Thus, Notch‐signaling biomaterials provide a robust approach to control keratinocyte differentiation and may find application to other progenitor and stem cells. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Preparation and characterization of alginate/gelatin blend films for cardiac tissue engineering
Authors: Rosellini Elisabetta , Cristallini Caterina , Barbani Niccoletta , Vozzi Giovanni , Giusti Paolo 
Published: November 2008

AbstractThe aim of this work was the preparation of blends based on alginate and gelatin, with different weight ratio, to combine the advantages of these two natural polymers for application in cardiac tissue engineering. The physicochemical characterization, performed by Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis, revealed a good miscibility and the presence of interactions among the functional groups of pure biopolymers. Concerning the swelling and degradation tests, performed in different solutions simulating body fluids, both swelling degree and weight losses were higher in phosphate buffer saline (PBS) and for the blends with a higher content of gelatin. These results indicated a better stability of the blends in cell culture medium than in PBS and suggested a mainly hydrolytic degradation process. Cell culture tests, carried out using C2C12 myoblasts, showed a good cell proliferation for all the blends containing more than 60% of gelatin, with the alginate/gelatin 20:80 showing the best response. The same blend was the only one on which cell differentiation was observed. The results obtained in the biological characterization allow to select the alginate/gelatin 20:80 blend as a suitable material to prepare scaffolds for myocardial tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Addition of TPGS to folate‐conjugated polymer micelles for selective tumor targeting
Authors: Zhao Haizheng , Yung Lin Yue Lanry 
Published: November 2008

AbstractFolate‐conjugated polymer micelles poly(D,L‐lactide‐co‐glycolide)‐poly(ethylene glycol)‐folate (PLGA‐PEG‐FOL) was fabricated to encapsulate anticancer drug doxorubicin for targeting delivery to cancer cells with overexpression of folate receptors. To increase therapeutic effect, D‐α‐tocopheryl polyethylene glycol succinate (TPGS) was added during the micelles preparation. The physicochemical study showed that the mixed micelles of PLGA‐PEG‐FOL and TPGS formed a homogeneous population. The addition of TPGS did not result in much variation in the micellar size, surface charge, and drug encapsulation efficiency. The cellular uptake study showed that mixed micelles with TPGS had higher cellular uptake compared with the ones without TPGS to drug‐resistant cancer cells. These mixed micelles also selectively increased the cytotoxicity of drug on cancer cells but exhibited minimal cytotoxic enhancement on normal fibroblasts. Furthermore, the accumulation of rhodamine study showed that the mixed micelles with TPGS increased the cellular uptake of drugs on Caco‐2 cells. This indicates that TPGS in the mixed micelles may act as P‐glycoprotein inhibitor to reduce drug efflux. This new formulation with TPGS may have dual functions of folate‐mediated targeting and multidrug resistance inhibition and can be promising in improving the therapeutic efficacy of polymer micellar targeting delivery system. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Melt‐based compression‐molded scaffolds from chitosan–polyester blends and composites: Morphology and mechanical properties
Authors: Correlo V. M. , Boesel L. F. , Pinho E. , Costa‐Pinto A. R. , Alves da Silva M. L. , Bhattacharya M. , Mano J. F. , Neves N. M. , Reis R. L. 
Published: November 2008

AbstractBlends of chitosan and synthetic aliphatic polyesters (polybutylene succinate, polybutylene succinate adipate, polycaprolactone, and polybutylene terepthalate adipate) were compounded with and without hydroxyapatite, a bioactive mineral filler known to enhance osteoconduction. The blends and composites were compression molded with two different granulometric salt sizes (63–125 μm and 250–500 μm) having different levels of salt content (60, 70, and 80%) by weight. By leaching the salt particles, it was possible to produce porous scaffolds with distinct morphologies. The relationship between scaffold morphology and mechanical properties was evaluated using scanning electron microscopy, microcomputed tomography, compression testing, differential scanning calorimetry, small‐angle X‐ray scattering (SAXS), and wide‐angle X‐ray scattering. The produced scaffolds are characterized by having different morphologies depending on the average particle size and the amount of NaCl used. Specimens with higher porosity level have a less organized pore structure but increased interconnectivity of the pores. The stress–strain curve under compression displayed a linear elasticity followed by a plateau whose characteristics depend on the scaffold polymer composition. A decrease in the salt particle size used to create the porosity caused in general a decrease in the mechanical properties of the foams. Composites with hydroxyapatite had a sharp reduction in yield stress, modulus, and strain at break. The melting temperature decreased with increased chitosan content. SAXS results indicate no preferential crystalline orientation in the scaffolds. Cytotoxicity evaluation were carried out using standard tests (accordingly to ISO/EN 10993 part 5 guidelines), namely MTS test with a 24‐h extraction period, revealing that L929 cells had comparable metabolic activities to that obtained for the negative control. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Assessment of novel chemical strategies for covalent attachment of adhesive peptides to rough titanium surfaces: XPS analysis and biological evaluation
Authors: Dettin Monica , Herath Thushari , Gambaretto Roberta , Iucci Giovanna , Battocchio Chiara , Bagno Andrea , Ghezzo Francesca , Di Bello Carlo , Polzonetti Giovanni , Di Silvio Lucy 
Published: November 2008

AbstractBioactive molecules have been proposed to promote beneficial interactions at bone‐implant interfaces for enhancing integration. The main objective of this study was to develop novel methods to functionalize oxidized titanium surfaces by the covalent immobilization of bioactive peptides, through selective reaction involving single functional groups. In the first protocol, an aminoalkylsilane was covalently linked to the Ti oxide layer, followed by covalent binding of glutaric anhydride to the free NH2 groups. The carboxylic group of glutaric anhydride was used to condense the free N‐terminal group of the side‐chain protected peptide sequence. Finally, the surface was treated with trifluoroacetic acid to deprotect side‐chain groups. In the second protocol, the peptide was directly anchored to the Ti oxide surface via UV activation of an arylazide peptide analogue. X‐ray photoelectron spectroscopy analyses confirmed that modifications induced onto surface composition were in agreement with the reactions performed. The peptide density of each biomimetic surface was determined on the basis of radiolabeling and XPS derived reaction yields. The in vitro cellular response of the biomimetic surfaces was evaluated using a primary human osteoblast cell model. Cell adhesion, proliferation, differentiation, and mineralization were examined at initial‐, short‐, and long‐time periods. In was shown that the biomimetic surface obtained through photoprobe‐marked analogue that combines an easily‐performed modification provides a favorable surface for an enhanced cellular response. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Distinct extracellular matrix microenvironments of progenitor and carotid endothelial cells
Authors: Vartanian Keri B. , Kirkpatrick Sean J. , McCarty Owen J. T. , Vu Tania Q. , Hanson Stephen R. , Hinds Monica T. 
Published: November 2008

AbstractEndothelial cells (ECs) produce and maintain the local extracellular matrix (ECM), a critical function that contributes to EC and blood vessel health. This function is also crucial to vascular tissue engineering, where endothelialization of vascular constructs require a cell source that readily produces and maintains ECM. In this study, baboon endothelial progenitor cell (EPC) deposition of ECM (laminin, collagen IV, and fibronectin) was characterized and compared to mature carotid ECs, evaluated in both elongated and cobblestone morphologies typically found in vivo. Microfluidic micropatterning was used to create 15‐μm wide adhesive lanes with 45‐μm spacing to reproduce the elongated EC morphology without the influence of external forces. Both EPCs and ECs elongated on micropatterned lanes had aligned actin cytoskeleton and readily deposited ECM. EPCs deposited and remodeled the ECM to a greater extent than ECs. Since a readily produced ECM can improve graft patency, EPCs are an advantageous cell source for endothelializing vascular constructs. Furthermore, EC deposition of ECM was dependent on cell morphology, where elongated ECs deposited more collagen IV and less fibronectin compared to matched cobblestone controls. Thus micropatterned surfaces controlled EC shape and ECM deposition, which ultimately has implications for the design of tissue‐engineered vascular constructs. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Three‐dimensional conductive constructs for nerve regeneration
Authors: George Paul M. , Saigal Rajiv , Lawlor Michael W. , Moore Michael J. , LaVan David A. , Marini Robert P. , Selig Martin , Makhni Melvin , Burdick Jason A. , Langer Robert , Kohane Daniel S. 
Published: November 2008

AbstractThe unique electrochemical properties of conductive polymers can be utilized to form stand‐alone polymeric tubes and arrays of tubes that are suitable for guides to promote peripheral nerve regeneration. Noncomposite, polypyrrole (PPy) tubes ranging in inner diameter from 25 μm to 1.6 mm as well as multichannel tubes were fabricated by electrodeposition. While oxidation of the pyrrole monomer causes growth of the film, brief subsequent reduction allowed mechanical dissociation from the electrode mold, creating a stand‐alone, conductive PPy tube. Conductive polymer nerve guides made in this manner were placed in transected rat sciatic nerves and shown to support nerve regeneration over an 8‐week time period. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009