bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glucose Dehydrogenase Based Bioelectrode Utilizing a Synergistic Scheme of Substrate Conversion
Authors: Kulys Juozas , Bratkovskaja Irina 
Published: January 2012

AbstractA Bioelectrode utilizing a synergistic scheme of substrate conversion was built using glucose dehydrogenase from Acinetobacter calcoaceticus immobilized on the surface of a graphite electrode. At saturated glucose concentration the bioelectrode responded to the low reactive substrate hexacyanoferrate(III) with a sensitivity of 0.0035 µA/µM cm2. The response of the bioelectrode increased up to the 3.4×104 fold in the presence of high reactive organic electron acceptors (mediators). The increase of the response depended on the concentration of the mediators and their chemical nature. The sensitivity of the bioelectrode to mediators reached 7.3–77 µA/µM cm2. The comparison of the bioelectrode sensitivity with kinetic parameters of enzyme action in homogeneous solution revealed good correlation between the sensitivity of the bioelectrode and the predicted value from the kinetic scheme of the reactivity of mediators. This confirms a synergistic scheme of bioelectrode action.
The effect of near‐fault directivity on building seismic collapse risk
Authors: Champion Casey , Liel Abbie 
Published: January 2012

SUMMARYForward directivity may cause large velocity pulses in ground motion time histories that are damaging to buildings at sites close to faults, potentially increasing seismic collapse risk. This study quantifies the effects of forward directivity on collapse risk through incremental dynamic analysis of building simulation models that are capable of capturing the key aspects of strength and stiffness degradation associated with structural collapse. The paper also describes a method for incorporating the effects of near‐fault directivity in probabilistic assessment of seismic collapse risk. The analysis is based on a suite of RC frame models that represent both past and present building code provisions, subjected to a database of near‐fault, pulse‐like ground motions with varying pulse periods. Results show that the predicted collapse capacity is strongly influenced by variations in pulse period and building ductility; pulse periods that are longer than the first‐mode elastic building period tend to be the most damaging. A detailed assessment of seismic collapse risk shows that the predicted probability of collapse in 50 years for modern concrete buildings at a representative near‐fault site is approximately 6%, which is significantly higher than the 1% probability in the far‐field region targeted by current seismic design maps in the US. Copyright © 2012 John Wiley & Sons, Ltd.
RISK PERCEPTION, PREVENTION AND DIAGNOSTIC TESTS
Authors: Etner Johanna , Jeleva Meglena 
Published: January 2012

ABSTRACTThe objective of this paper is to study the impact of risk perception and diagnostic information on medical prevention decisions. The intertemporal preferences of individuals are represented by a model of recursive rank dependent utility, which has the advantage of allowing risk perceptions to vary over time and with health status. The main results of the paper are the following. Concerning the impact of risk perception on prevention, two types of pessimists have to be distinguished: the moderate pessimists and the fatalists. Both types overestimate the probability of disease, but the fatalists underestimate the reduction of the disease probability by prevention. Risk perception modification after the occurrence of the disease influences prevention decisions. Indeed, we show that moderate pessimists often choose a high level of primary and tertiary prevention, but a moderate pessimist who becomes fatalist after the occurrence of the disease may choose a high level of primary prevention and a low level of tertiary prevention. Copyright © 2012 John Wiley & Sons, Ltd.
Regulation of myocardial matrix metalloproteinase expression and activity by cardiac fibroblasts
Authors: Turner Neil A. , Porter Karen E. 
Published: January 2012

AbstractCardiac fibroblasts (CF) play a key role in orchestrating the structural remodeling of the myocardium in response to injury or stress, in part through direct regulation of extracellular matrix (ECM) turnover. The matrix metalloproteinases (MMPs) are a family of over 25 zinc‐dependent proteases that together have the capacity to degrade all the protein components of the ECM. Fibroblasts are a major source of several MMPs in the heart, thereby representing a viable therapeutic target for regulating ECM turnover in cardiac pathologies characterized by adverse remodeling, such as myocardial infarction, cardiomyopathy, hypertension and heart failure. This review summarizes current knowledge on the identity and regulation of MMPs expressed by CF and discusses future directions for reducing adverse myocardial remodeling by modulating the expression and/or activity of CF‐derived MMPs. © 2012 IUBMB IUBMB Life, 2012.
In situ formation of porous space maintainers in a composite tissue defect
Authors: Spicer Patrick P. , Kretlow James D. , Henslee Allan M. , Shi Meng , Young Simon , Demian Nagi , Jansen John A. , Wong Mark E. , Mikos Antonios G. , Kasper F. Kurtis 
Published: January 2012

AbstractReconstruction of composite defects involving bone and soft tissue presents a significant clinical challenge. In the craniofacial complex, reconstruction of the soft and hard tissues is critical for both functional and aesthetic outcomes. Constructs for space maintenance provide a template for soft tissue regeneration, priming the wound bed for a definitive repair of the bone tissue with greater success. However, materials used clinically for space maintenance are subject to poor soft tissue integration, which can result in wound dehiscence. Porous materials in space maintenance applications have been previously shown to support soft tissue integration and to allow for drug release from the implant to further prepare the wound bed for definitive repair. This study evaluated solid and low porosity (16.9% ± 4.1%) polymethylmethacrylate space maintainers fabricated intraoperatively and implanted in a composite rabbit mandibular defect model for 12 weeks. The data analyses showed no difference in the solid and porous groups both histologically, evaluating the inflammatory response at the interface and within the pores of the implants, and grossly, observing the healing of the soft tissue defect over the implant. These results demonstrate the potential of porous polymethylmethacrylate implants formed in situ for space maintenance in the craniofacial complex, which may have implications in the potential delivery of therapeutic drugs to prime the wound site for a definitive bone repair. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Collagen–silica xerogel nanohybrid membrane for guided bone regeneration
Authors: Lee Eun‐Jung , Jun Shin‐Hee , Kim Hyoun‐Ee , Koh Young‐Hag 
Published: January 2012

AbstractA collagen–silica xerogel hybrid membrane was fabricated by a sol–gel process for guided bone regeneration (GBR). The silica xerogel synthesized by the sol–gel method was distributed uniformly within the collagen matrix in the form of nanoparticles. The hybridization of the silica xerogel with collagen improved the biological properties of the membrane significantly. Preosteoblast cells were observed to adhere well and grow much more actively on the hybrid membrane than on the pure collagen membrane. In particular, the hybrid membrane containing 30% of the silica xerogel showed the highest level of osteoblast differentiation. Moreover, the GBR ability, as assessed by the in vivo animal test, was superior to that of the pure collagen membrane. These findings suggest that the collagen–silica xerogel hybrid can be used as a GBR membrane. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Dual surface modification with PEG and corn trypsin inhibitor: Effect of PEG:CTI ratio on protein resistance and anticoagulant properties
Authors: Alibeik Sara , Zhu Shiping , Yau Jonathan W. , Weitz Jeffrey I. , Brash John L. 
Published: January 2012

AbstractThe objective of this study was to investigate the bioactivity and protein‐resistant properties of dual functioning surfaces modified with PEG for protein resistance and corn trypsin inhibitor (CTI) for anticoagulant effect. Surfaces on gold substrate were prepared with varying ratios of free PEG to CTI‐conjugated PEG. Two methods designated, respectively, “sequential” and “direct” were used. For sequential surfaces, PEG was first immobilized on gold and the surfaces were incubated with CTI at varying concentration. For direct surfaces, a PEG–CTI conjugate was synthesized and gold surfaces were modified using solutions of the conjugate of varying concentration. The CTI density on these surfaces was measured using radiolabeled CTI. Water contact angles were measured and the thickness of PEG–CTI layers was determined by ellipsometry. Fibrinogen adsorption from buffer and human plasma, and adsorption from binary solutions of fibrinogen and α‐lactalbumin were investigated using radiolabeling methods. Bioactivity of the surfaces was evaluated via their effects on FXIIa inhibition and plasma clotting time. It was found that as the ratio of CTI‐conjugated PEG to free PEG increased, bioactivity increased but protein resistance was relatively constant. It is concluded that on these surfaces conjugation of PEG to CTI does not greatly compromise the protein resistance of the PEG but results in improved interactions between the CTI and the “target” protein FXIIa. At the same CTI density, sequential surfaces were more effective in terms of inhibiting FXIIa and prolonging clotting time. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Intramyocardial hematoma with epicardial rupture following percutaneous coronary intervention
Authors: Ertan Cagatay , Ozeke Ozcan , Demir Ahmet Duran 
Published: January 2012

AbstractIntramyocardial (or subepicardial) hematomas are uncommon conditions that occur mostly after myocardial infarction, percutaneous coronary intervention (PCI), coronary artery bypass surgery, cardiac surgery, or chest trauma. Coronary perforation is a rare complication of PCI and the subset of patients developing an intramyocardial hematoma, usually considered a catastrophic event, is even rarer. We describe here the case of 63‐year‐old man in whom an intramyocardial hematoma with epicardial rupture occurred after PCI. The patient was treated conservatively with a successful outcome. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2013.
Effect of surface roughness on magneto‐hydrodynamic couple‐stress squeeze film lubrication between circular stepped plates
Authors: Naduvinamani N. B. , Hanumagowda B. N. , Siddangouda A. 
Published: January 2012

ABSTRACTIn this paper, a theoretical analysis of the problem of magneto‐hydrodynamic couple‐stress squeeze film lubrication between rough circular stepped plates is presented. The modified averaged Reynolds equation is derived for the two types of one‐dimensional roughness structures, namely the radial roughness pattern and the azimuthal roughness pattern. The closed‐form expressions are obtained for the mean squeeze film pressure, load‐carrying capacity and squeeze film time. The results are presented for different operating parameters. It is observed that the effect of azimuthal (radial) roughness pattern on the bearing surface is to increase (decrease) the mean load‐carrying capacity and squeeze film time. The applied magnetic field increases the load‐carrying capacity and lengthens the squeezing time. Copyright © 2012 John Wiley & Sons, Ltd.
Pressure viscosity coefficients and traction properties of synthetic lubricants for wind turbine gear systems
Authors: Greaves Martin 
Published: January 2012

ABSTRACTSynthetic lubricants are increasingly used to provide equipment reliability for wind turbine gear boxes. The majority of synthetic lubricants used today are based on polyalphaolefins. In gear systems where contact pressures are high, the pressure viscosity coefficient and traction values of the lubricant are important fundamental properties. A comparison of these properties for a wind turbine lubricant based on a polyalphaolefin and two lubricants based on polyalkylene glycols has been undertaken. Pressure viscosity coefficients were calculated from viscosity measurements made using an ultra‐high pressure falling needle viscometer at pressures up to 50 000 psi. Significant differences in properties were observed with both polyalkylene glycol lubricants showing lower pressure viscosity coefficients and much lower traction values. A calculation of the film thickness values in the Hertzian contact zone suggests that polyalkylene glycol lubricants may provide elastohydrodynamic films that are approximately 25% thicker than polyalphaolefin lubricants. Copyright © 2012 John Wiley & Sons, Ltd.
Optimal wavelengths for vein‐selective photothermolysis
Authors: Rubin Iris K. , Farinelli William A. , Doukas Apostolos , Anderson R. Rox 
Published: January 2012

AbstractBackground and ObjectiveOxyhemoglobin (HbO2) has been regarded as the primary target chromophore for selective photothermolysis of vascular malformations. In theory, venous lesions might be better treated with wavelengths preferentially absorbed by deoxyhemoglobin (Hb).Study Design/Materials and MethodsWavelength‐dependent fluence thresholds for photocoagulation of whole human blood were determined in glass capillary samples with measured oxygen saturation levels. Pulsed dye lasers at 585, 590, 595, 600, 633 nm, a 694 nm ruby laser, a 755 nm alexandrite laser, and a 1,064 nm Nd:Yag laser were used, all with 1.5–3 milliseconds pulse width and similar exposure spot size.ResultsSelectivity (a lower fluence threshold) for venous blood was maximal at 694 nm, and significant at 595, 600, 633, and 755 nm. At 633 nm, a wavelength with strong relative absorption by metHb, selectivity for venous blood was much less than expected. The Nd:YAG laser at 1,064 nm showed significant selectivity for arterial blood.ConclusionPreferential photocoagulation of venous blood is possible at wavelengths with a high Hb/HbO2 absorption coefficient ratio. Laser‐induced metHb may also affect wavelength‐dependent selective photothermolysis. Venular malformations such as port wine stains could potentially be treated more selectively with ∼630–780 nm sources. Nd:YAG laser pulses at 1,064 nm tend to affect arterial more than venous blood. Lasers Surg. Med. 44:152–157, 2012. © 2012 Wiley Periodicals, Inc.
Huntington's disease: Objective assessment of posture—A link between motor and functional deficits
Authors: Reilmann Ralf , Rumpf Silke , Beckmann Heike , Koch Raphael , Ringelstein Erich B. , Lange Herwig W. 
Published: January 2012

AbstractBackground:Postural deficits in Huntington's disease are linked to functional impairment. We investigated whether assessment of center‐of‐mass variability using posturography provides objective and quantitative measures that correlate to the severity of motor phenotype, functional measures, and genotype as assessed by a disease burden score (based on repeat length and age). In addition, we investigated whether withdrawing visual feedback facilitates the detection of postural deficits.Methods:Using a force plate, the ability of symptomatic Huntington's disease patients (n = 34) and controls (n = 20) to stand as stably as possible was assessed in eyes‐open and eyes‐closed conditions.Results:All posturographic measures (DISTANCE, VELOCITY, and SURFACE of centre‐of‐mass mobility) were increased in patients and correlated to (1) the UHDRS Total Motor Score, (2) the UHDRS Total Functional Capacity, (3) the UHDRS Functional Assessment Score, and (4) the disease burden score. Correlations to motor and functional measures were stronger when visual feedback was provided.Conclusions:Posturography may provide useful objective and quantitative measures of postural motor dysfunction in Huntington's disease. © 2012 Movement Disorder Society
Optimization of iron oxide nanoparticle detection using ultrashort echo time pulse sequences: Comparison of T1, T2*, and synergistic T1 − T2* contrast mechanisms
Authors: Girard O. M. , Du J. , Agemy L. , Sugahara K. N. , Kotamraju V. R. , Ruoslahti E. , Bydder G. M. , Mattrey R. F. 
Published: January 2012

AbstractIron oxide nanoparticles (IONPs) are used in various MRI applications as negative contrast agents. A major challenge is to distinguish regions of signal void due to IONPs from those due to low signal tissues or susceptibility artifacts. To overcome this limitation, several positive contrast strategies have been proposed. Relying on IONP T1 shortening effects to generate positive contrast is a particularly appealing strategy because it should provide additional specificity when associated with the usual negative contrast from effective transverse relaxation time (T2*) effects. In this article, ultrashort echo time imaging is shown to be a powerful technique which can take full advantage of both contrast mechanisms. Methods of comparing T1 and T2* contrast efficiency are described and general rules that allow optimizing IONP detection sensitivity are derived. Contrary to conventional wisdom, optimizing T1 contrast is often a good strategy for imaging IONPs. Under certain conditions, subtraction of a later echo signal from the ultrashort echo time signal not only improves IONP specificity by providing long T2* background suppression but also increases detection sensitivity, as it enables a synergistic combination of usually antagonist T1 and T2* contrasts. In vitro experiments support our theory, and a molecular imaging application is demonstrated using tumor‐targeted IONPs in vivo. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Co‐administration of statins with cytochrome P450 3A4 inhibitors in a UK primary care population
Authors: Bakhai Ameet , Rigney Una , Hollis Samuel , Emmas Cathy 
Published: January 2012

ABSTRACTPurposeThe co‐administration of cytochrome P450 3A4 (CYP3A4) inhibitors with simvastatin or atorvastatin (CYP3A4‐metabolised statins) is associated with increased statin exposure and can increase the risk of adverse drug reactions. The aim of this study was to measure the concomitant exposure of patients to CYP3A4‐metabolised statins and CYP3A4 inhibitors in the UK primary care population.MethodsThe co‐administration of statins and CYP3A4 inhibitors during 2008 was examined in the General Practice Research Database, a large nationally representative UK primary care database. All known inhibitors were included with labelled inhibitors identified using the Medicines and Healthcare products Regulatory Agency Drug Safety Update and UK summary of product characteristics for statins. Exposure was examined in patients overall, patients 65 years and older and those prescribed higher doses of statins.ResultsThere were 364 574 patients included in the analyses. Ninety‐three percent of the patients were prescribed CYP3A4‐metabolised statins, most whom received simvastatin (72%) and atorvastatin (24%). Approximately one third (30%) of the patients prescribed a CYP3A4‐metabolised statin had also been prescribed a concomitant CYP3A4 inhibitor during the study period, including 11% prescribed a concomitant labelled inhibitor, with an annualised median days of concomitant use of 173 days, predominantly involving macrolide antibiotics and calcium channel blockers co‐prescriptions. Rates were higher in the subgroup aged 65 and over and in those on high dose statins.ConclusionsThe co‐prescription of CYP3A4‐metabolised statins and CYP3A4 inhibitors is common in UK primary care. This co‐prescription suggests the limited appreciation of potential interactions and Medicines and Healthcare products Regulatory Agency safety advice, with the potential to increase likelihood for side effects amongst patients. Strategies to reduce drug interactions with potential adverse effects should be targeted at prescribers and pharmacists. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of dual inhibition of apoptosis and autophagy in prostate cancer
Authors: Saleem Ahamed , Dvorzhinski Dmitri , Santanam Urmila , Mathew Robin , Bray Kevin , Stein Mark , White Eileen , DiPaola Robert S. 
Published: January 2012

AbstractPURPOSETargeting multiple anti‐apoptotic proteins is now possible with the small molecule BH3 domain mimetics such as ABT‐737. Given recent studies demonstrating that autophagy is a resistance mechanism to multiple therapeutic agents in the setting of apoptotic inhibition, we hypothesized that hydroxychloroquine (HCQ), an anti‐malarial drug that inhibits autophagy, will increase cytotoxicity of ABT‐737.EXPERIMENTAL DESIGNCytotoxicity of ABT‐737 and HCQ was assessed in vitro in PC‐3 and LNCaP cells, and in vivo in a xenograft mouse model. The role of autophagy as a resistance mechanism was assessed by siRNA knockdown of the essential autophagy gene beclin1. ROS was measured by flow cytometry, and mitophagy assessed by the mCherry‐Parkin reporter.RESULTSInduction of autophagy by ABT‐737 was a mechanism of resistance in prostate cancer cell lines. Therapeutic inhibition of autophagy with HCQ increased cytotoxicity of ABT‐737 both in vitro and in vivo. ABT‐737 induced LC‐3 and decreased p62 expression by immunoblot in cell lines and by immunohistochemistry in tumors in vivo. Assessment of ROS and mitochondria demonstrated that ROS production by ABT‐737 and HCQ was a mechanism of cytotoxicity.CONCLUSIONSWe demonstrated that autophagy inhibition with HCQ enhances ABT‐737 cytotoxicity in vitro and in vivo, that LC‐3 and p62 represent assessable markers in human tissue for future clinical trials, and that ROS induction is a mechanism of cytotoxicity. These results support a new paradigm of dual targeting of apoptosis and autophagy in future clinical studies. Prostate 72:1374–1381, 2012. © 2012 Wiley Periodicals, Inc.
Reading Coaches and the Relationship Between Policy and Practice
Authors: Coburn Cynthia E. , Woulfin Sarah L. 
Published: January 2012

AbstractMany educational policy initiatives use instructional coaching to accomplish their goals. Yet we know little about the role of reading coaches in mediating the relationship between policy and teachers’ classroom practice. In this article, we investigate the role of reading coaches in mediating the relationship between Reading First policy and teachers’ classroom practice. We conducted an in‐depth, longitudinal case study of one urban elementary school in Massachusetts, starting the year before the onset of Reading First and continuing through the first year of its implementation. In our analysis, we focus on seven first‐ and second‐grade teachers, two coaches, and two school administrators. We argue that, although reading coaches were only one of multiple sources from which teachers learned about Reading First policy, teachers were much more likely to make substantial changes in their classroom practice when they learned about the policy message from a coach than from other sources. Coaches influenced teachers by helping them to learn new approaches and to integrate them into their classroom. But, they also did so by pressuring teachers, shaping how they saw and understood Reading First, and by counseling them on which aspects of the policy to focus on and which aspects to ignore. Thus, we present a vision of coaching that goes much beyond its educational roles, to highlight the political roles of the coach as well. We close by drawing implications for research on coaching, policy implementation, and practice.