bluuebunny/crossref_metadata_2025_split huggingface dataset:
Triple repetition time saturation transfer (TRiST) 31P spectroscopy for measuring human creatine kinase reaction kinetics
Authors: Schär Michael , El‐Sharkawy AbdEl‐Monem M. , Weiss Robert G. , Bottomley Paul A. 
Published: May 2010

AbstractHuman cardiac phosphorus MR saturation transfer experiments to quantify creatine kinase forward rate constants (kf) have previously been performed at 1.5 T. Such experiments could benefit from increased signal‐to‐noise ratio (SNR) and spectral resolution at 3 T. At 1.5 T, the four‐angle saturation transfer method was applied with low‐angle adiabatic pulses and surface coils. However, low‐angle adiabatic pulses are potentially problematic above 1.5 T due to bandwidth limitations, power requirements, power deposition, and intrapulse spin‐spin relaxation. For localized metabolite spin‐lattice relaxation time (T1) measurements, a dual repetition time approach with adiabatic half‐passage pulses was recently introduced to solve these problems at 3 T. Because the saturation transfer experiment requires a T1 measurement performed while one reacting moiety is saturated, we adapt the dual repetition time approach to measure kf using a triple repetition time saturation transfer (TRiST) method. A new pulsed saturation scheme with reduced sensitivity to static magnetic field inhomogeneity and compatibility with cardiac triggering is also presented. TRiST measurements of kf are validated in human calf muscle against conventional saturation transfer and found to agree within 3%. The first 3‐T TRiST measurements of creatine kinase kf in the human calf (n = 6), chest muscle, and heart (n = 8) are 0.26 ± 0.04 s−1, 0.23 ± 0.03 s−1, and 0.32 ± 0.07 s−1, respectively, consistent with prior 1.5 T values. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Improved 3‐Tesla cardiac cine imaging using wideband
Authors: Lee Hsu‐Lei , Shankaranarayanan Ajit , Pohost Gerald M. , Nayak Krishna S. 
Published: May 2010

AbstractCine balanced steady‐state free precession (SSFP) is the most widely used sequence for assessing cardiac ventricular function at 1.5 T because it provides high signal‐to‐noise ratio efficiency and strong contrast between myocardium and blood. At 3 T, the use of SSFP is limited by susceptibility‐induced off‐resonance, resulting in either banding artifacts or the need to use a short‐sequence pulse repetition time that limits the readout duration and hence the achievable spatial resolution. In this work, we apply wideband SSFP, a variant of SSFP that uses two alternating pulse repetition times to establish a steady state with wider band spacing in its frequency response and overcome the key limitations of SSFP. Prospectively gated cine two‐dimensional imaging with wideband SSFP is evaluated in healthy volunteers and compared to conventional balanced SSFP, using quantitative metrics and qualitative interpretation by experienced clinicians. We demonstrate that by trading off temporal resolution and signal‐to‐noise ratio efficiency, wideband SSFP mitigates banding artifacts and enables imaging with approximately 30% higher spatial resolution compared to conventional SSFP with the same effective band spacing. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Molecular imaging of angiogenic therapy in peripheral vascular disease with ανβ3‐integrin‐targeted nanoparticles
Authors: Winter Patrick M. , Caruthers Shelton D. , Allen John S. , Cai Kejia , Williams Todd A. , Lanza Gregory M. , Wickline Samuel A. 
Published: May 2010

AbstractNoninvasive molecular imaging of angiogenesis could play a critical role in the clinical management of peripheral vascular disease patients. The ανβ3‐integrin, a well‐established biomarker of neovascular proliferation, is an ideal target for molecular imaging of angiogenesis. This study investigates whether MR molecular imaging with ανβ3‐integrin‐targeted perfluorocarbon nanoparticles can detect the neovascular response to angiogenic therapy. Hypercholesterolemic rabbits underwent femoral artery ligation followed by no treatment or angiogenic therapy with dietary L‐arginine. MR molecular imaging performed 10 days after vessel ligation revealed increased signal enhancement in L‐arginine‐treated animals compared to controls. Furthermore, specifically targeted nanoparticles produced two times higher MRI signal enhancement compared to nontargeted particles, demonstrating improved identification of angiogenic vasculature with biomarker targeting. X‐ray angiography performed 40 days postligation revealed that L‐arginine treatment increased the development of collateral vessels. Histologic staining of muscle capillaries revealed a denser pattern of microvasculature in L‐arginine‐treated animals, confirming the MR and X‐ray imaging results. The clinical application of noninvasive molecular imaging of angiogenesis could lead to earlier and more accurate detection of therapeutic response in peripheral vascular disease patients, enabling individualized optimization for a variety of treatment strategies. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Characterization of 1H NMR signal in human cortical bone for magnetic resonance imaging
Authors: Horch R. Adam , Nyman Jeffry S. , Gochberg Daniel F. , Dortch Richard D. , Does Mark D. 
Published: May 2010

AbstractRecent advancements in MRI have enabled clinical imaging of human cortical bone, providing a potentially powerful new means for assessing bone health with molecular‐scale sensitivities unavailable to conventional X‐ray‐based diagnostics. In human cortical bone, MRI is sensitive to populations of protons (1H) partitioned among water and protein sources, which may be differentiated according to intrinsic NMR properties such as chemical shift and transverse and longitudinal relaxation rates. Herein, these NMR properties were assessed in human cortical bone donors from a broad age range, and four distinct 1H populations were consistently identified and attributed to five microanatomical sources. These findings show that modern human cortical bone MRI contrast will be dominated by collagen‐bound water, which can also be exploited to study human cortical bone collagen via magnetization transfer. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Compartment‐specific enhancement of white matter and nerve ex vivo using chromium
Authors: Dortch Richard D. , Apker Greg A. , Valentine William M. , Lai Barry , Does Mark D. 
Published: May 2010

AbstractChromium—Cr(VI) in the form of potassium dichromate—has been shown to specifically enhance white matter signal. The proposed mechanism for this enhancement is reduction of diamagnetic Cr(VI) to paramagnetic chromium species by oxidizable myelin lipids. The purpose of the study herein was to better understand the microanatomical basis of this enhancement (i.e., the relative enhancement of myelin, intra‐axonal, and extra‐axonal water). Toward this end, integrated T1‐T2 measurements were performed in potassium dichromate loaded (hereafter referred to as chromated) rat brains, rat optic nerve samples, and frog sciatic nerve samples ex vivo. In control optic nerve and white matter, two T1‐T2 components were resolved, representing myelin and nonmyelin water (intra‐ and extra‐axonal water). Following chromation, three T1‐T2 components were resolved in these same tissues. Results from similar measurements in sciatic nerve—all three components are resolvable in control and chromated samples—and quantitative histologic analysis suggest that this additional T1‐T2 component is due to a splitting of the nonmyelin water component into intra‐ and extra‐axonal water components. This compartment‐specific enhancement may provide unique contrast for MR histology, as well as allow one to probe the compartmental basis of various contrast mechanisms in neural tissue. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Designing adiabatic radio frequency pulses using the Shinnar–Le Roux algorithm
Authors: Balchandani Priti , Pauly John , Spielman Daniel 
Published: May 2010

AbstractAdiabatic pulses are a special class of radio frequency (RF) pulses that may be used to achieve uniform flip angles in the presence of a nonuniform B1 field. In this work, we present a new, systematic method for designing high‐bandwidth (BW), low‐peak‐amplitude adiabatic RF pulses that utilizes the Shinnar–Le Roux (SLR) algorithm for pulse design. Currently, the SLR algorithm is extensively employed to design nonadiabatic pulses for use in magnetic resonance imaging and spectroscopy. We have adapted the SLR algorithm to create RF pulses that also satisfy the adiabatic condition. By overlaying sufficient quadratic phase across the spectral profile before the inverse SLR transform, we generate RF pulses that exhibit the required spectral characteristics and adiabatic behavior. Application of quadratic phase also distributes the RF energy more uniformly, making it possible to obtain the same spectral BW with lower RF peak amplitude. The method enables the pulse designer to specify spectral profile parameters and the degree of quadratic phase before pulse generation. Simulations and phantom experiments demonstrate that RF pulses designed using this new method behave adiabatically. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Image‐based calculation of perfusion and oxyhemoglobin saturation in skeletal muscle during submaximal isometric contractions
Authors: Elder Christopher P. , Cook Ryan N. , Chance Marti A. , Copenhaver Elizabeth A. , Damon Bruce M. 
Published: May 2010

AbstractThe relative oxygen saturation of hemoglobin and the rate of perfusion are important physiological quantities, particularly in organs such as skeletal muscle, in which oxygen delivery and use are tightly coupled. The purpose of this study was to demonstrate the image‐based calculation of the relative oxygen saturation of hemoglobin and quantification of perfusion in skeletal muscle during isometric contractions. This was accomplished by establishing an empirical relationship between the rate of radiofrequency‐reversible dephasing and near‐infrared spectroscopy–observed oxyhemoglobin saturation (relative oxygen saturation of hemoglobin) under conditions of arterial occlusion and constant blood volume. A calibration curve was generated and used to calculate the relative oxygen saturation of hemoglobin from radiofrequency‐reversible dephasing changes measured during contraction. Twelve young healthy subjects underwent 300 s of arterial occlusion and performed isometric contractions of the dorsiflexors at 30% of maximal contraction for 120 s. Muscle perfusion was quantified during contraction by arterial spin labeling and measures of muscle T1. Comparisons between the relative oxygen saturation of hemoglobin values predicted from radiofrequency‐reversible dephasing and that measured by near‐infrared spectroscopy revealed no differences between methods (P = 0.760). Muscle perfusion reached a value of 34.7 mL 100 g−1 min−1 during contraction. These measurements hold future promise in measuring muscle oxygen consumption in healthy and diseased skeletal muscle. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Bayesian estimation of changes in transverse relaxation rates
Authors: Walker‐Samuel Simon , Orton Matthew , McPhail Lesley D. , Boult Jessica K. R. , Box Gary , Eccles Suzanne A. , Robinson Simon P. 
Published: May 2010

AbstractAlthough the biasing of
R*2 estimates by assuming magnitude MR data to be normally distributed has been described, the effect on changes in R*2 (ΔR*2), such as induced by a paramagnetic contrast agent, has not been reported. In this study, two versions of a novel Bayesian maximum a posteriori approach for estimating ΔR*2 are described and evaluated: one that assumes normally distributed data and the other, Rice‐distributed data. The approach enables the robust, voxelwise determination of the uncertainty in ΔR*2 estimates and provides a useful statistical framework for quantifying the probability that a pixel has been significantly enhanced. This technique was evaluated in vivo, using ultrasmall superparamagnetic iron oxide particles in orthotopic murine prostate tumors. It is shown that assuming magnitude data to be normally distributed causes ΔR*2 to be underestimated when signal‐to‐noise ratio is modest. However, the biasing effect is less than is found in R*2 estimates, implying that the simplifying assumption of normally distributed noise is more justifiable when evaluating ΔR*2 compared with when evaluating precontrast R*2 values. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
See‐Sedimente als Zeugen der Schadstoffbelastung
Authors: Bogdal Christian , Schmid Peter , Anselmetti Flavio S. , Scheringer Martin 
Published: May 2010

AbstractSchadstoffmessungen in den Sedimenten von Seen ermöglichen es, die Eintragsgeschichte von Chemikalien zu rekonstruieren. In Gletscherseen steigt die Konzentration persistenter organischer Schadstoffe, die längst verboten sind.
Organischen Kohlenstoff in Feststoffen messen
Authors: Hupach Sascha 
Published: May 2010

AbstractEin neues Verfahren macht feste Proben zu flüssigen Proben, um ihren Gehalt an organischem Kohlenstoff zu bestimmen. Es besteht aus drei Schritten: Einwiegen, Dispergieren und Messen.
Umfangreiches Programm trotz sinkender Teilnehmerzahlen
Authors: Terborg Lydia 
Published: May 2010

AbstractZur Pittcon in Orlando reisten zwar noch weniger Besucher an als im Jahr zuvor, das Programm konnte sich aber sehen lassen. Etwa 960 Unternehmen präsentierten ihre neuesten Analytikgeräte.
Analytical integrations in 3D BEM for elliptic problems: Evaluation and implementation
Authors: Salvadori A. 
Published: May 2010

AbstractThe present publication deals with 3D elliptic boundary value problems (potential, Stokes, elasticity) in the framework of linear, isotropic, and homogeneous materials. Numerical approximation of the unique solution is achieved by 3D boundary element methods (BEMs). Adopting polynomial test and shape functions of arbitrary degree on flat triangular discretizations, the closed form of integrals that are involved in the 3D BEMs is proposed and discussed. Analyses are performed for all operators (single layer, double layer, hypersingular). The Lebesgue integrals are solved working in a local coordinate system. For singular integrals, both a limit to the boundary as well as the finite part of Hadamard (Lectures on Cauchy's Problem in Linear Partial Differential Equations. Yale University Press: New Haven, CT, U.S.A., 1923) approach have been considered. Copyright © 2010 John Wiley & Sons, Ltd.
Finite deformation frictional mortar contact using a semi‐smooth Newton method with consistent linearization
Authors: Gitterle Markus , Popp Alexander , Gee Michael W. , Wall Wolfgang A. 
Published: May 2010

AbstractA two‐dimensional, finite deformation frictional contact formulation with Coulomb's law is presented. The approach considers multibody contact and is based on a mortar formulation. The enforcement of contact constraints is realized with dual Lagrange multipliers. These alternative multiplier spaces are constructed in a way that the multipliers can easily be eliminated from the global system of equations by static condensation such that the system size does not increase. Friction kinematic variables are formulated in an objective way and enter non‐smooth complementarity functions for expressing the contact constraints. An active set strategy is derived by applying a semi‐smooth Newton method, which treats contact nonlinearities, material and geometrical nonlinearities in one single iterative scheme. By further carrying out a consistent linearization for both normal and frictional contact forces and constraints, a robust and highly efficient algorithm for linear and higher‐order (quadratic) interpolation is achieved. Efficiency of the proposed method and quality of results are demonstrated in several examples. Copyright © 2010 John Wiley & Sons, Ltd.
Coupled meshfree and fractal finite element method for mixed mode two‐dimensional crack problems
Authors: Rajesh K. N. , Rao B. N. 
Published: May 2010

AbstractThis paper presents a coupling technique for integrating the element‐free Galerkin method (EFGM) with the fractal finite element method (FFEM) for analyzing homogeneous, isotropic, and two‐dimensional linear‐elastic cracked structures subjected to mixed‐mode (modes I and II) loading conditions. FFEM is adopted for discretization of the domain close to the crack tip and EFGM is adopted in the rest of the domain. In the transition region interface elements are employed. The shape functions within interface elements which comprise both the EFG and the finite element (FE) shape functions, satisfies the consistency condition thus ensuring convergence of the proposed coupled EFGM–FFEM. The proposed method combines the best features of EFGM and FFEM, in the sense that no special enriched basis functions or no structured mesh with special FEs are necessary and no post‐processing (employing any path independent integrals) is needed to determine fracture parameters, such as stress‐intensity factors (SIFs) and T‐stress. The numerical results show that SIFs and T‐stress obtained using the proposed method are in excellent agreement with the reference solutions for the structural and crack geometries considered in the present study. Also, a parametric study is carried out to examine the effects of the integration order, the similarity ratio, the number of transformation terms, and the crack length to width ratio on the quality of the numerical solutions. A numerical example on mixed‐mode condition is presented to simulate crack propagation. As in the proposed coupled EFGM–FFEM at each increment during the crack propagation, the FFEM mesh (around the crack tip) is shifted as it is to the new updated position of the crack tip (such that FFEM mesh center coincides with the crack tip) and few meshless nodes are sprinkled in the location where the FFEM mesh was lying previously, crack‐propagation analysis can be dramatically simplified. Copyright © 2010 John Wiley & Sons, Ltd.
Twins in prehistory: The case from Olèrdola (Barcelona, Spain; s. IV II BC)
Authors: Crespo L. , Subirà M. E. , Ruiz J. 
Published: May 2010

AbstractThis paper details the discovery of two perinatal individuals interred simultaneously at the archaeological site of Olèrdola, Barcelona, Spain. Information from the excavation and from the subsequent anthropological study of the recovered skeletal and dental remains suggests that these individuals (OL–2000–8245 and OL–2000–8246) are the first documented case of twins in Iberian period. The possibility of a simultaneous perinatal twins burial at Olèrdola raises new questions concerning about the frequency of twins in prehistory and protohistory. Copyright © 2010 John Wiley & Sons, Ltd.
The association between preeclampsia and placental disruption induced by chorionic villous sampling
Authors: Farina Antonio , Hasegawa Junichi , Raffaelli Simonetta , Ceccarini Chiara , Rapacchia Giuseppina , Pittalis M. Carla , Brondelli Lorena , Righetti Francesca , Rizzo Nicola 
Published: May 2010

AbstractObjectivesThe objectives of this study were (1) to evaluate if the elevation of maternal serum α‐feto protein (MSAFP) and pregnancy‐associated placental protein‐A (PAPP‐A) in the maternal blood after chorionic villous sampling (CVS) is associated with a higher preeclampsia (PE) rate and (2) to verify the clinical utility of the analytes elevation for predicting PE.MethodsA prospective study on 106 subjects who underwent CVS was performed. At the time of CVS, two blood samples were obtained for MSAFP and PAPP‐A dosage, the first just before the procedure, and the second one 30 min after the procedure. Cases with abnormal karyotype, major anomalies or preterm delivery were subsequently excluded. The ratio between the two samples was calculated as Σ (MSAFP or PAPP‐A post‐CVS/MSAFP or PAPP‐A pre‐CVS) and it was related to subsequent occurrence of PE.ResultsThe rate of PE was 5.7% (6/106). Both MSAFP and PAPP‐A levels were higher after than before CVS (median ratio = 8.33 and 1.08, respectively). Cases developing PE had significantly higher MSAFP ratio (11.6 vs 7.4, p‐value = 0.04) and PAPP‐A ratio (1.13 vs 1.08, p‐value = 0.009) than those who did not develop PE. Receiver operating characteristic curve analysis showed that PAPP‐A ratio was a better predictor of subsequent PE than MSAFP ratio: at a fixed false positive rate of 10%, the detection rates for MSAFP and PAPP‐A ratios were 33 and 50%, respectively.ConclusionThe elevation of MSAFP and PAPP‐A observed with CVS is associated with increased risk of subsequent PE. The ability of such increases to predict PE appears to be modest. Copyright © 2010 John Wiley & Sons, Ltd.
ABCD position statement on physical activity and exercise in diabetes
Authors: Nagi D , Gallen I 
Published: May 2010

AbstractThe Association of British Clinical Diabetologists (ABCD) recognises the key importance of exercise and physical activity in the management of diabetes. This position statement by the ABCD aims to help health professionals working in diabetes to familiarise themselves with the issues surrounding the management of type 1 and type 2 diabetes.ABCD strongly supports that exercise and physical activity are key components of the initial and ongoing management of type 2 diabetes and can help to improve metabolic control and tackle cardiovascular risk factors. ABCD also believes that diabetes teams have an important role both in promotion of physical activity and in education of the key benefits to patients, carers and health professionals involved in the day to day management of this condition. ABCD also recognises that the issues in type 1 diabetes are very different and that, in this category of patients, the health benefits of exercise are not well documented – the issue is to help and support people to engage in physical activity or sports of their choice in a safe manner. This kind of support is not universally available at present and much needs to be done to achieve this. Copyright © 2010 John Wiley & Sons.
Recommending NSAIDs and paracetamol: A survey of New Zealand physiotherapists' knowledge and behaviours
Authors: Braund Rhiannon , Abbott J. Haxby 
Published: May 2010

AbstractBackground. Clinical guidelines recommend medications as first line treatment for many musculoskeletal injuries. As first line health professionals for musculoskeletal conditions, including sprains and strains, physiotherapists may be asked to recommend suitable medications. Currently recommending medications is outside of the physiotherapists scope of practice. However there is evidence that physiotherapists often do recommend medications, mostly simple analgesics and non‐steroidal anti‐inflammatory drugs (NSAIDs). Purpose. The aim of this study was to investigate the current knowledge and behaviour of New Zealand musculoskeletal physiotherapists regarding recommendation of non‐prescription medications for the treatment of musculoskeletal sprains and strains. Method. 2438 New Zealand physiotherapists were surveyed, of whom approximately 948 work in musculoskeletal physiotherapy. Results. Of 278 respondents (29.3% response rate), 213 (81.0%) sometimes or often recommend oral NSAIDs to patients, and 216 (82.1%) recommend oral paracetamol. Most respondents (225, 85.5%) report that they routinely provide information on potential side effects, 181 (68.8%) on potential risks. Many refer to a pharmacist, however 146 (55.5%) make recommendations on dose, and 119 (45.2%) recommend specific brand names. When asked what the risks associated with NSAIDs were, most respondents (>70%) were able to name at least gastrointestinal upset, ulcers or bleeding, while the proportion able to name respiratory, renal or allergic risks was lower (<31%). Conclusion. These data indicate that a large proportion of New Zealand musculoskeletal physiotherapists are practicing outside of the general scope of physiotherapy practice with regards recommending medicines to patients. While a large proportion have a good knowledge of potential side effects and risks, the knowledge is incomplete and inadequate for this practice. Copyright © 2010 John Wiley & Sons, Ltd.