bluuebunny/crossref_metadata_2025_split huggingface dataset:
High temperature causes masculinization of genetically female medaka by elevation of cortisol
Authors: Hayashi Yuki , Kobira Hiroshi , Yamaguchi Toshiya , Shiraishi Eri , Yazawa Takashi , Hirai Toshiaki , Kamei Yasuhiro , Kitano Takeshi 
Published: May 2010

AbstractIn poikilothermic vertebrates, sex determination is sometimes influenced by environmental factors such as temperature. However, little is known about the molecular mechanisms underlying environmental sex determination. The medaka (Oryzias latipes) is a teleost fish with an XX/XY sex determination system. Recently, it was reported that XX medaka can be sex‐reversed into phenotypic males by high water temperature (HT; 32–34°C) treatment during the sex differentiation period. Here we report that cortisol caused female‐to‐male sex reversal and that metyrapone (an inhibitor of cortisol synthesis) inhibited HT‐induced masculinization of XX medaka. HT treatment caused elevation of whole‐body levels of cortisol, while metyrapone suppressed the elevation by HT treatment during sexual differentiation. Moreover, cortisol and 33°C treatments inhibited female‐type proliferation of germ cells as well as expression of follicle‐stimulating hormone receptor (fshr) mRNA in XX medaka during sexual differentiation. These results strongly suggest that HT induces masculinization of XX medaka by elevation of cortisol level, which, in turn, causes suppression of germ cell proliferation and of fshr mRNA expression. Mol. Reprod. Dev. 77: 679–686, 2010. © 2010 Wiley‐Liss, Inc.
Reducing distortions in diffusion‐weighted echo planar imaging with a dual‐echo blip‐reversed sequence
Authors: Gallichan Daniel , Andersson Jesper L. R. , Jenkinson Mark , Robson Matthew D. , Miller Karla L. 
Published: May 2010

AbstractThe inherent distortions in echo‐planar imaging that arise due to inhomogeneities in the static magnetic field can lead to difficulties when attempting to obtain structurally accurate diffusion‐tensor imaging data. Parallel acceleration techniques can reduce the magnitude of these distortions but do not remove them entirely. Images can be corrected using a measured field map, but this is prone to error. One approach to correcting for these distortions, referred to here as “blip‐reversed” echo‐planar imaging, involves collecting a second set of images with the phase encoding reversed. Here, a novel approach to collecting blip‐reversed echo‐planar imaging data for diffusion‐tensor imaging is presented: a dual‐echo sequence is used in which the phase‐encoding direction of the second echo is swapped compared to the first echo. This allows benefits of the blip‐reversed approach to be exploited, with only a modest increase in scan time and, due to the extra data acquired, no significant loss of signal‐to‐noise efficiency. A novel approach to recombining blip‐reversed data is also presented, which involves refining the measured field map, using an algorithm to minimize the difference between the corrected images. The field map refinement is also applicable to conventionally acquired blip‐reversed sequences. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Noncompartmental kinetic analysis of DCE‐MRI data from malignant tumors: Application to glioblastoma treated with bevacizumab
Authors: Port Ruediger E. , Bernstein Lisa J. , Barboriak Daniel P. , Xu Lu , Roberts Timothy P. L. , van Bruggen Nicholas 
Published: May 2010

AbstractDynamic contrast enhanced MRI contrast agent kinetics in malignant tumors are typically complex, requiring multicompartment tumor models for adequate description. For consistent comparisons among tumors or among successive studies of the same tumor, we propose to estimate the total contrast agent–accessible volume fraction of tumor, including blood plasma, vpe, and an average transfer rate constant across all tumor compartments, Ktrans.av, by fitting a three‐compartment tumor model and then calculating the area under the tumor impulse‐response function (= vpe) and the ratio area under the tumor impulse response function over mean residence time in tumor (= Ktrans.av). If the duration of dynamic contrast enhanced MRI was too short to extrapolate the tumor impulse‐response function to infinity with any confidence, then conditional parameters v and Ktrans.av* should be calculated from the available incomplete impulse response function. Median decreases of 33% were found for both v and Ktrans.av* in glioblastoma patients (n = 16) 24 hours after the administration of bevacizumab (P < 0.001). Median total contrast‐enhancing tumor volume was reduced by 18% (P < 0.0001). The combined changes of tumor volume, v, and Ktrans.av* suggest a reduction of true vpe, possibly accompanied by a reduction of true Ktrans.av. The proposed method provides estimates of a scale and a shape parameter to describe contrast agent kinetics of varying complexity in a uniform way. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
The acellular matrix (ACM) for bladder tissue engineering: A quantitative magnetic resonance imaging study
Authors: Cheng Hai‐Ling Margaret , Loai Yasir , Beaumont Marine , Farhat Walid A. 
Published: May 2010

AbstractBladder acellular matrices (ACMs) derived from natural tissue are gaining increasing attention for their role in tissue engineering and regeneration. Unlike conventional scaffolds based on biodegradable polymers or gels, ACMs possess native biomechanical and many acquired biologic properties. Efforts to optimize ACM‐based scaffolds are ongoing and would be greatly assisted by a noninvasive means to characterize scaffold properties and monitor interaction with cells. MRI is well suited to this role, but research with MRI for scaffold characterization has been limited. This study presents initial results from quantitative MRI measurements for bladder ACM characterization and investigates the effects of incorporating hyaluronic acid, a natural biomaterial useful in tissue‐engineering and regeneration. Measured MR relaxation times (T1, T2) and diffusion coefficient were consistent with increased water uptake and glycosaminoglycan content observed on biochemistry in hyaluronic acid ACMs. Multicomponent MRI provided greater specificity, with diffusion data showing an acellular environment and T2 components distinguishing the separate effects of increased glycosaminoglycans and hydration. These results suggest that quantitative MRI may provide useful information on matrix composition and structure, which is valuable in guiding further development using bladder ACMs for organ regeneration and in strategies involving the use of hyaluronic acid. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Vessel‐encoded dynamic magnetic resonance angiography using arterial spin labeling
Authors: Okell Thomas W. , Chappell Michael A. , Woolrich Mark W. , Günther Matthias , Feinberg David A. , Jezzard Peter 
Published: May 2010

AbstractA new noninvasive MRI method for vessel‐selective angiography is presented. The technique combines vessel‐encoded pseudocontinuous arterial spin labeling with a two‐dimensional dynamic angiographic readout and was used to image the cerebral arteries in healthy volunteers. Time‐of‐flight angiograms were also acquired prior to vessel‐selective dynamic angiography acquisitions in axial, coronal, and/or sagittal planes, using a 3‐T MRI scanner. The latter consisted of a vessel‐encoded pseudocontinuous arterial spin labeling pulse train of 300 or 1000 ms followed by a two‐dimensional thick‐slab flow‐compensated fast low‐angle shot readout combined with a segmented Look‐Locker sampling strategy (temporal resolution = 55 ms). Selective labeling was performed at the level of the neck to generate individual angiograms for both right and left internal carotid and vertebral arteries. Individual vessel angiograms were reconstructed using a bayesian inference method. The vessel‐selective dynamic angiograms obtained were consistent with the time‐of‐flight images, and the longer of the two vessel‐encoded pseudocontinuous arterial spin labeling pulse train durations tested (1000 ms) was found to give better distal vessel visibility. This technique provides highly selective angiograms quickly and noninvasively that could potentially be used in place of intra‐arterial x‐ray angiography for larger vessels. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Absence of a significant extravascular contribution to the skeletal muscle BOLD effect at 3 T
Authors: Sanchez Otto A. , Copenhaver Elizabeth A. , Elder Christopher P. , Damon Bruce M. 
Published: May 2010

AbstractBlood oxygenation level dependent (BOLD) contrast in skeletal may reflect the contributions of both intravascular and extravascular relaxation effects. The purpose of this study was to determine the significance of the extravascular BOLD effect in skeletal muscle at 3 T. In experiments, R2* was measured before and during arterial occlusion under the following conditions: (1) the leg extended and rotated (to vary the capillary orientation with respect to the amplitude of static field) and (2) with the blood's signal nulled using a multiecho vascular space occupancy experiment. In the leg rotation protocol, 3 min of arterial occlusion decreased oxyhemoglobin saturation from 67% to 45% and increased R2* from 34.2 to 36.6 sec−1, but there was no difference in the R2* response to occlusion between the extended and rotated positions. Numerical simulations of intra‐ and extravascular BOLD effects corresponding to these conditions predicted that the intravascular BOLD contribution to the R2* change was always > 50 times larger than the extravascular BOLD contribution. Blood signal nulling eliminated the change in R2* caused by arterial occlusion. These data indicate that under these experimental conditions, the contribution of the extravascular BOLD effect to skeletal muscle R2* was too small to be practically important. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Factors related to self‐efficacy in persons with scleroderma
Authors: Buck Una , Poole Janet , Mendelson Cindy 
Published: May 2010

AbstractPurpose: Scleroderma (SSc) is rare, and few studies have examined self‐efficacy in persons with the disease. Self‐efficacy is one precursor that has been shown to initiate changes in behaviour when managing chronic disease. The objective of this study was to explore the levels of self‐efficacy in persons with SSc, compare self‐efficacy in persons with limited or diffuse SSc and determine correlations between self‐efficacy, physical function and psychological variables.Methods: Sixty‐two participants with SSc completed measures assessing self‐efficacy, depression, fatigue, pain, hand function and activity limitations. The mean age of participants was 52.9 years. The mean educational level was 15.8 years. Sixty‐seven per cent were married and 87.1% were women. Thirty participants had diffuse SSc, 27 had limited SSc and five were unclassified.Results: The only significant differences between the two disease subtypes were in hand function and self‐efficacy function subscale scores. Total self‐efficacy scores significantly correlated with marital status, employment, self‐reported health, depression, functional ability, fatigue, pain and hand function. Similarly, self‐efficacy function scale scores correlated significantly with employment, self‐reported health, functional ability, pain and hand function. Self‐efficacy pain scale scores correlated significantly with fatigability. The self‐efficacy other scale scores correlated significantly with depression and fatigability. Participants with higher levels of pain and depression, more fatigue, more general disability and more hand disability had lower self‐efficacy.Conclusion: Self‐efficacy correlates with physical function and psychological variables, and could predict how patients manage their health. Self‐efficacy may increase through participation in educational programmes focusing on self‐management of these variables. Copyright © 2010 John Wiley & Sons, Ltd.
Can the application of control theory assist patient management in rheumatoid arthritis?
Authors: Mann Cindy 
Published: May 2010

AbstractSupporting patient self‐management is an important part of the care of patients with rheumatoid arthritis (RA) but patients vary in their capacity and willingness to manage their illness and may feel overwhelmed by the challenge of controlling the impact on their life. This paper discusses the value and importance of control theory and how it might be applied to enhance patients' self‐management. Not only does it offer a means of identifying those who might have greatest difficulty in managing their illness, but it also points the way to effective interventions. Copyright © 2010 John Wiley & Sons, Ltd.
Monitoring disease progression using high‐density motor unit number estimation in amyotrophic lateral sclerosis
Authors: van Dijk Johannes P. , Schelhaas Helenius J. , Van Schaik Ivo N. , Janssen Henny M.H.A. , Stegeman Dick F. , Zwarts Machiel J. 
Published: May 2010

AbstractIn amyotrophic lateral sclerosis (ALS), progressive motor neuron loss causes severe weakness. Functional measurements tend to underestimate the underlying pathology because of collateral reinnervation. A more direct marker of lower motor neuron loss is of significant importance. We evaluated high‐density motor unit number estimation (MUNE), as compared with the ALS Functional Rating Scale (ALSFRS) and maximal compound muscle action potential (CMAP) amplitude, for monitoring and classifying disease progression. MUNE showed good reproducibility (intraclass correlation coefficient = 0.86). MUNE showed a significantly greater decrease than the ALSFRS, the Medical Research Council (MRC) scale, and CMAP amplitude. Patients could be stratified into groups with rapidly or slowly progressive disease based on a decrement in MUNE at 4 months from baseline; ALSFRS score at 8 months was significantly lower in the rapidly progressive group. MUNE was sensitive to motor neuron loss early in the disease course when compared to other clinical measures. Stratification of patients based on a decrease in MUNE seems feasible. Muscle Nerve, 2010
Nonsurgical transurethral collagen denaturation for stress urinary incontinence in women: 18‐month results from a prospective long‐term study
Authors: Elser Denise M. , Mitchell Gretchen K. , Miklos John R. , Nickell Kevin G. , Cline Kevin , Winkler Harvey , Wells W. Glen 
Published: May 2010

AbstractAimsTo evaluate 18‐month safety and durability of efficacy of nonsurgical transurethral collagen denaturation as treatment for stress urinary incontinence (SUI) in women.MethodsStudy comprised women with SUI due to bladder outlet hypermobility for at least 12 months who failed conservative treatment and had not undergone surgery or bulking agent treatment. This one‐time procedure was performed in a physician's office or ambulatory treatment center. Patients kept voiding diaries and completed the Incontinence Quality of Life (I‐QOL), Urogenital Distress Inventory (UDI‐6), and Patient Global Impression of Improvement measures at baseline and at 3, 6, 12, and 18 months posttreatment.ResultsAt 18 months, intent‐to‐treat analysis revealed that patients experienced significant reductions in the median number of stress leaks daily (0.43; P < 0.006) and weekly (3.0; P < 0.006) versus baseline, with 46.7% reporting a 50% or greater reduction in leakage. Mean I‐QOL score improved 10.9 points (median 8.5; P < 0.0001), with 47.8% having a 10‐point or greater improvement and 50.4% reporting improved symptoms versus baseline. Mean UDI‐6 improvement was 13.0 points, with a stress incontinence subscore improvement of 17.0 points. Overall, 47.0% of patients were “somewhat” or “very” satisfied, and 52.9% would recommend the procedure to a friend. The procedure was shown to be safe and effective, with no new treatment‐related adverse events reported at 18 months.ConclusionsTransurethral collagen denaturation resulted in significant improvements in stress leaks and quality of life for at least 18 months. This procedure offers a safe, effective, nonsurgical treatment option for women with SUI. Neurourol. Urodynam. 29:1424–1428, 2010. © 2010 Wiley‐Liss, Inc.
Evaluating the use of different waveforms for intravesical electrical stimulation: A study in the rat
Authors: De Bock Filip , Dirckx Joris , Wyndaele Jean‐Jacques 
Published: May 2010

AbstractAimFor decades, monophasic square wave pulses have been used for intravesical electrical stimulation (IVES) in diagnosis and treatment of lower urinary tract dysfunction. The use of other waveforms, more preferred by patients or more effective for neural stimulation, has hardly been studied before. This study compares the effect of several waveforms and derived parameters in IVES.MethodsIVES, performed in eight female Sprague–Dawley rats, was given for 300 sec with constant frequency (10 Hz) and current amplitude (6 mA) with unipolar square, biphasic square, asymmetric biphasic square, double square, unipolar exponential rise, biphasic exponential rise, and double‐exponential rise wavepulses with different pulse durations (2 × 5 msec, 20 msec, or 2 × 20 msec). Bladder pressure was recorded. Average current and average power were calculated.ResultsStimulations with the different waveforms resulted in the same maximal pressure rise (all P > 0.1). The average charge was zero for biphasic waveforms. For exponential rise pulse waveforms the total injected charge was lower than that for the monophasic square pulse waveform. The average power was the highest for biphasic waveforms and the lowest for monophasic double‐exponential rise pulses waveform.ConclusionsCharge‐balanced waveforms, which are more preferred by patients, are equally effective in evoking IVES‐induced detrusor contraction as monophasic square pulse waveforms. Thus, it can be beneficial in clinical practice to replace the monophasic square pulse waveform for IVES by charge‐balanced waveforms. Furthermore, the stimulation power and thus the requested energy can be reduced by changing the waveform. This can be important for electrical stimulation using implanted batteries. Neurourol. Urodyn. 30:169–173, 2011. © 2010 Wiley‐Liss, Inc.
Max–min utility fair flow management for networks with route diversity
Authors: Rubin Izhak , Zhang Runhe 
Published: May 2010

AbstractA regional central manager is employed to set aside, for the regional (or back‐bone) network that it manages, for each flow class, communications capacity resources for a specific future time horizon. In the context of such a traffic management operation, a longer temporal scale is involved in controlling the admission and distribution of flows across the network. For management scal‐ability purposes, flows are aggregated into flow classes. Furthermore, we consider a network operation under which multiple simultaneously activated routes are employed, across possibly distinct segments, to distribute traffic between identified source–destination pairs. We aim to ensure that the utility assigned to each class is as high as feasibly possible while striving to raise the utility gained by all classes in a max–min fair manner. In doing so, we incorporate the communications capacity constraints that are imposed by the underlying hybrid of directional and/or multiple‐access wireline and wireless communications media employed across the network system. We develop and present in this paper an optimal algorithm for solving such a traffic management problem. It yields multi‐utility‐based max–min fair distributions of flow rates, per each class, across the specified multitude of simultaneously activated multi‐segment routes. To guarantee that admitted flows are granted their desired capacity resources (and targeted corresponding utility levels), the selection of optimal flow distributions across the network routes is combined with the use of a flow admission control scheme that serves to optimally limit the aggregate rate of flows admitted for each flow class. As illustrative examples, we demonstrate the effectiveness of our solution in comparing its performance with that obtained under the use of a traffic regulation scheme that is not overlaid with a traffic management mechanism that serves to set aside resources for the support of flow classes. We also illustrate the use of our optimal algorithm for determining the optimal placement of unmanned aerial vehicle platforms that serve to supplement a terrestrial transport segment with a space‐based one. Copyright © 2010 John Wiley & Sons, Ltd.
Three‐dimensional modelling and simulation of magnetorheological fluids
Authors: Han K. , Feng Y. T. , Owen D. R. J. 
Published: May 2010

AbstractA magnetorheological fluid (MR fluid) is a type of smart fluid composed of micrometer‐sized magnetizable particles suspended in a carrier fluid. The rheological properties of an MR fluid can be greatly altered upon application of an external magnetic field. This paper presents a computational framework for the numerical study of MR fluids, in which a two‐stage modelling and simulation strategy is proposed to achieve reasonable accuracy and computational efficiency. At the first stage for simulating the particle chain formation, the particle dynamics plays a major role whereas the hydrodynamics of the fluid flow is of secondary importance. Thus an MR fluid is modelled in the context of the discrete element method and the simple Stokes formula is adopted for the hydrodynamic interaction. At the second stage, the formulated particle chains are applied as the initial configuration for simulating the rheological properties of the fluid under different shear loading conditions. A combined lattice Boltzmann and discrete element approach is employed to fully resolve the fluid field and the hydrodynamic interactions between the fluid and the particles. Some relevant magnetic models are comprehensively reviewed and the mutual dipole model is employed in this work to account for the magnetic interactions between the particles. The proposed solution procedure is illustrated via a set of numerical simulations for a representative volume element of an MR fluid. Copyright © 2010 John Wiley & Sons, Ltd.
A theoretical study on the smoothed FEM (S‐FEM) models: Properties, accuracy and convergence rates
Authors: Liu G. R. , Nguyen‐Xuan H. , Nguyen‐Thoi T. 
Published: May 2010

AbstractIncorporating the strain smoothing technique of meshfree methods into the standard finite element method (FEM), Liu et al. have recently proposed a series of smoothed finite element methods (S‐FEM) for solid mechanics problems. In these S‐FEM models, the compatible strain fields are smoothed based on smoothing domains associated with entities of elements such as elements, nodes, edges or faces, and the smoothed Galerkin weak form based on these smoothing domains is then applied to compute the system stiffness matrix. We present in this paper a general and rigorous theoretical framework to show properties, accuracy and convergence rates of the S‐FEM models. First, an assumed strain field derived from the Hellinger–Reissner variational principle is shown to be identical to the smoothed strain field used in the S‐FEM models. We then define a smoothing projection operator to modify the compatible strain field and show a set of properties. We next establish a general error bound of the S‐FEM models. Some numerical examples are given to verify the theoretical properties established. Copyright © 2010 John Wiley & Sons, Ltd.