bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the application of chemical shift‐based multipoint water‐fat separation methods in balanced SSFP imaging
Authors: Kim Hyeonjin , Pinus Alexander B. , Wang Jinghua , Murphy Philip S. , Constable R. Todd 
Published: July 2007

AbstractChemical shift‐based multipoint water‐fat separation methods have been applied in balanced steady‐state free precession (bSSFP) sequences because of the high signal‐to‐noise‐ratio (SNR) attainable. In this approach the echo formation is approximated to occur concurrently for both water and fat at an echo time (TE) equal to half the repetition time (TR/2 approximation). However, the degree to which the imaging conditions underlying the TR/2 approximation are satisfied can significantly vary in vivo depending upon the imaging region of interest (ROI) and the pixels across a field of view (FOV). The consequence of the TR/2 approximation on chemical shift‐based multipoint water‐fat separation was investigated. The influence of a mismatch between the pass‐band profiles of water and fat (pass‐band mismatch) on fat quantification was also examined. Theoretical and experimental results demonstrate that the TR/2 approximation can result in spatially dependent noise performance of multipoint water‐fat separation methods, and the pass‐band mismatch can render the precision of fat quantification spatially dependent. Given that local tissue characteristics in affected liver can be substantially variable, this study is of particular importance in liver imaging. Magn Reson Med 58:413–418, 2007. © 2007 Wiley‐Liss, Inc.
Spectroscopic imaging of the pilocarpine model of human epilepsy suggests that early NAA reduction predicts epilepsy
Authors: Gomes W.A. , Lado F.A. , de Lanerolle N.C. , Takahashi K. , Pan C. , Hetherington H.P. 
Published: July 2007

AbstractReduced hippocampal N‐acetyl aspartate (NAA) is commonly observed in patients with advanced, chronic temporal lobe epilepsy (TLE). It is unclear, however, whether an NAA deficit is also present during the clinically quiescent latent period that characterizes early TLE. This question has important implications for the use of MR spectroscopic imaging (MRSI) in the early identification of patients at risk for TLE. To determine whether NAA is diminished during the latent period, we obtained high‐resolution 1H spectroscopic imaging during the latent period of the rat pilocarpine model of human TLE. We used actively detuneable surface reception and volume transmission coils to enhance sensitivity and a semiautomated voxel shifting method to accurately position voxels within the hippocampi. During the latent period, 2 and 7 d following pilocarpine treatment, hippocampal NAA was significantly reduced by 27.5 ± 6.9% (P < 0.001) and 17.3 ± 6.9% (P < 0.001) at 2 and 7 d, respectively. Quantitative estimates of neuronal loss at 7 d (2.3 ± 7.7% reduction; P = 0.58, not significant) demonstrate that the NAA deficit is not due to neuron loss and therefore likely represents metabolic impairment of hippocampal neurons during the latent phase. Therefore, spectroscopic imaging provides an early marker for metabolic dysfunction in this model of TLE. Magn Reson Med 58:230–235, 2007. © 2007 Wiley‐Liss, Inc.
Absolute and relative contributions of BOLD effects to the muscle functional MRI signal intensity time course: Effect of exercise intensity
Authors: Damon Bruce M. , Wadington Megan C. , Hornberger Jennifer L. , Lansdown Drew A. 
Published: July 2007

AbstractThe time course of exercise‐induced T2‐weighted signal intensity (SI) changes contains an initial rise, early dip, and secondary rise. The purposes of this study were to test the hypothesis that the secondary rise occurs earlier during more intense contractions, and to determine the contribution of BOLD contrast to the SI changes. Eight subjects performed 90‐s isometric dorsiflexion contractions at 30% and 60% of maximum voluntary contraction (MVC) while T2‐weighted (TR/TE = 4000 ms/35 ms) images were acquired and total hemoglobin ([THb]) and oxy‐Hb saturation (%HbO2) were measured. At 30% MVC, [THb] remained constant and %HbO2 decreased from 66.3% (standard error [SEM] = 2.6%) to 32.4% (SEM = 6.4%). At t = 88 s, SI increased by ∼8% and was greater than at t = 8 and 56s. At 60% MVC, [THb] remained constant and %HbO2 decreased from 70.2% (SEM = 2.3%) to 40.4% (SEM = 5.4%). SI increased by ∼17% and at t = 56 and 88 s was greater than at t = 8 and 20 s. The absolute contribution of calculated BOLD effects was −1% at 30% and 60% MVC. The relative contribution was greater at 30% than at 60% MVC (up to −26% and −10%, respectively). We conclude that the secondary rise occurs earlier at 60% MVC and that the relative contribution of BOLD effects is greater during less intense contractions. Magn Reson Med 58:335–345, 2007. © 2007 Wiley‐Liss, Inc.
Development of a compact MRI system for trabecular bone microstructure measurements of the distal radius
Authors: Handa Shinya , Tomiha Sadanori , Haishi Tomoyuki , Kose Katsumi 
Published: July 2007

AbstractA compact MRI system for trabecular bone (TB) microstructure measurements of the distal radius was developed using a 1.0 T permanent magnet and a compact MRI console. TB microstructure of the distal radius was clearly visualized using a three‐dimensional (3D) driven equilibrium spin‐echo (DESE) sequence in 23 min. The image obtained had a sufficient spatial resolution (150 μm × 150 μm × 500 μm) and signal‐to‐noise ratio (SNR) (approximately 10) for 3D bone microstructure analysis. The system demonstrated the feasibility of using a permanent magnet compact MRI system as a clinical instrument for bone microstructure measurements of the distal radius. Magn Reson Med 58:225–229, 2007. © 2007 Wiley‐Liss, Inc.
On the noise correlation matrix for multiple radio frequency coils
Authors: Brown Ryan , Wang Yi , Spincemaille Pascal , Lee Ray F. 
Published: July 2007

AbstractNoise correlation between multiple receiver coils is discussed using principles of statistical physics. Using the general fluctuation‐dissipation theorem we derive the prototypic correlation formula originally determined by Redpath (Magn Res Med 1992;24:85–89), which states that correlation of current spectral noise depends on the real part of the inverse impedance matrix at a given frequency. A distinct correlation formula is also derived using the canonical partition function, which states that correlation of total current noise over the entire frequency spectrum depends on the inverse inductance matrix. The Kramers‐Kronig relation is used to equate the inverse inductance matrix to the spectral integral of the inverse impedance matrix, implying that the total noise is equal to the summation of the spectral noise over the entire frequency spectrum. Previous conflicting arguments on noise correlation may be reconciled by differentiating between spectral and total noise correlation. These theoretical derivations are verified experimentally using two‐coil arrays. Magn Reson Med 58:218–224, 2007. © 2007 Wiley‐Liss, Inc.
Can studies of the second lumbrical interossei and its premotor potential reduce the number of tests for carpal tunnel syndrome?
Authors: Therimadasamy Aravinda K. , Li Eileen , Wilder‐Smith Einar P. 
Published: July 2007

AbstractThe second lumbrical interossei latency difference test (2‐LINT) is a frequently used test for diagnosing carpal tunnel syndrome (CTS). Recently, the premotor potential (2‐LUMP) observed with 2‐LINT was identified as a median sensory potential. 2‐LINT recording therefore not only compares conduction across equidistant median and ulnar motor segments, but also registers median sensory conduction. In 52 CTS and 50 control hands, we tested whether motor and sensory data obtained with 2‐LINT help to reduce the number of tests necessary to diagnose CTS. The combined sensitivity of 2‐LINT derived parameters (2‐LUMP latency, median second lumbrical to ulnar interossei latency difference, ulnar digit 5 sensory to 2‐LUMP velocity, and ulnar interossei to 2‐LUMP latency difference) was 89%, identical to that of combined non–2‐LINT derived parameters (median digit 3 sensory velocity, ulnar digit 5 to median digit 3 sensory velocity difference, median abductor pollices brevis [APB] latency, median APB to ulnar abductor digiti minimi latency). The 2‐LINT technique with its premotor potential may therefore help to reduce the number of nerve conduction tests commonly needed to investigate patients with suspected CTS. Muscle Nerve, 2007
Effect of age on adrenergic and vagal baroreflex sensitivity in normal subjects
Authors: Huang Chih‐Cheng , Sandroni Paola , Sletten David M. , Weigand Stephen D. , Low Phillip A. 
Published: July 2007

AbstractThe baroreflex maintains a stable blood pressure (BP) by dynamically adjusting heart rate (vagal component) and total peripheral resistance (adrenergic component). Vagal baroreflex sensitivity (BRS‐v) is widely used but no methodology existed to quantitate adrenergic baroreflex sensitivity (BRS‐a) until we developed the indices of BP recovery time (PRT) and BRS‐a. The aims of this study were to generate a normative database and to evaluate whether there is an age effect on the cardiovagal and adrenergic sensitivities. We evaluated recordings of heart rate (HR) and BP in 255 normal subjects during the Valsalva maneuver (VM) and determined both BRS‐v and BRS‐a sensitivities. PRT increased with age whereas all other parameters declined with age. The adrenergic parameters correlated well with each other but not significantly with BRS‐v. The results indicate that both BRS‐a and BRS‐v become blunted with increasing age and that these indices behave independently of each other. Muscle Nerve, 2007
Frequency of seronegativity in adult‐acquired generalized myasthenia gravis
Authors: Chan Koon Ho , Lachance Daniel H. , Harper C. Michel , Lennon Vanda A. 
Published: July 2007

AbstractWe determined the prevalence of muscle acetylcholine receptor (AChR) antibodies in patients with adult‐acquired generalized myasthenia gravis (MG), the seroconversion rate at 12 months, and the prevalence of muscle‐specific tyrosine kinase (MuSK) antibody among persistently seronegative patients. We identified 562 consecutive Mayo Clinic patients with MG based on clinical and electrophysiological criteria. At presentation, 508 patients (90.4%) tested positive for AChR binding or AChR modulating antibodies. After 12 months, 15.2% of initially seronegative patients had become seropositive, yielding a seronegativity rate of 8.2% (95% confidence interval: 6.2–9.6%). Among seronegative patients not receiving immunosuppressants, 38% were MuSK antibody‐positive and 43% were seropositive for nonmuscle autoantibodies. Classification as seronegative MG should be reserved for nonimmunosuppressed patients with generalized MG who lack muscle AChR binding, AChR modulating, or MuSK antibodies at presentation and at follow‐up of at least 12 months. Muscle Nerve, 2007
Pain and soreness associated with a percutaneous electrical stimulation muscle cramping protocol
Authors: Miller Kevin C. , Knight Kenneth L. 
Published: July 2007

AbstractMuscle cramps are difficult to study scientifically because of their spontaneity and unpredictability. Various laboratory techniques to induce muscle cramps have been explored but the best technique for inducing cramps is unclear. Electrical stimulation appears to be the most reliable, but there is a perception that it is extremely painful. Data to support this perception are lacking. We hypothesized that electrical stimulation is a tolerable method of inducing cramps with few side effects. We measured cramp frequency (HZ), pain during electrical stimulation, and soreness before, at 5 s, and 30, 60, and 90 min after cramp induction using a 100‐mm visual analog scale. Group 1 received tibial nerve stimulation on 5 consecutive days; Group 2 received it on alternate days for five total treatments. Pain and soreness were mild. The highest ratings occurred on Day 1 and decreased thereafter. Intersession reliability was high. Our study showed that electrical stimulation causes little pain or soreness and is a reliable method for inducing cramps. Muscle Nerve, 2007
Episodic hypoxia exacerbates respiratory muscle dysfunction in DMDmdx mice
Authors: Farkas Gaspar A. , Mccormick Kathleen M. , Gosselin Luc E. 
Published: July 2007

AbstractMany patients with Duchenne muscular dystrophy (DMD) are eventually diagnosed with sleep‐disordered breathing (SDB). SDB is associated with reduced ventilation, decreased arterial oxygen tension, and increased respiratory muscle recruitment during sleep, factors that could be especially detrimental to respiratory muscles in DMD. To assess whether SDB impacts dystrophin‐deficient respiratory muscle function and fibrosis, diaphragm strength, and collagen content were evaluated in dystrophic mice (Dmdmdx) exposed to experimental SDB. Diurnal exposure to episodic hypoxia resulted in a 30% reduction in diaphragm strength without affecting collagen content. Episodic hypoxia secondary to SDB can exacerbate respiratory muscle dysfunction in DMD. Muscle Nerve, 2007
Urethral diverticula: A review and an update
Authors: Rovner Eric S. 
Published: July 2007

AbstractLikely originating from the periurethral glands, female urethral diverticula (UD) are an uncommon but fascinating clinical entity. UD are variable in their presentation and the diagnosis is sometimes difficult and delayed. Modern imaging modalities such as surface coil and endoluminal magnetic resonance imaging (MRI) have added to the diagnostic armamentarium but have also furthered our understanding of UD. Accurate preoperative characterization of the often complex anatomical patterns seen on these imaging studies including saddlebag and circumferential urethral involvement, as well as complete evaluation of associated voiding dysfunction such as complete evaluation of associated voiding dysfunction such as urinary incontinence often impacts contemporary surgical management. Neurourol. Urodynam. 26:972–977, 2007. © 2007 Wiley‐Liss, Inc.
Tail hazard rate ordering properties of order statistics and coherent systems
Authors: Navarro Jorge 
Published: July 2007

AbstractWe study tail hazard rate ordering properties of coherent systems using the representation of the distribution of a coherent system as a mixture of the distributions of the series systems obtained from its path sets. Also some ordering properties are obtained for order statistics which, in this context, represent the lifetimes of k‐out‐of‐n systems. We pay special attention to systems with components satisfying the proportional hazard rate model or with exponential, Weibull and Pareto type II distributions. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
The maximum residual flow problem:NP‐hardness with two‐arc destruction
Authors: Du Donglei , Chandrasekaran R. 
Published: July 2007

AbstractThe maximum residual flow problem with one‐arc destruction is shown to be solvable in strongly polynomial time in [Aneja et al., Networks, 38 (2001), 194–198]. However, the status of the corresponding problem with more than one‐arc destruction is left open therein. We resolve the status of the two‐arc destruction problem by demonstrating that it is already NP‐hard. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(3), 181–182 2007
Continuum approximation techniques for the design of integrated package distribution systems
Authors: Smilowitz Karen R. , Daganzo Carlos F. 
Published: July 2007

AbstractComplex package distribution systems are designed using idealizations of network geometries, operating costs, demand and customer distributions, and routing patterns. The goal is to find simple, yet realistic, guidelines to design and operate a network integrated both by transportation mode and service level; i.e., overnight (express) and longer (deferred) deadlines. The decision variables and parameters that define the problem are presented along with the models to approximate total operating cost. The design problem is then reduced to a series of optimization subproblems that can be solved easily. The proposed approach provides valuable insight for the design and operation of integrated package distribution systems. Qualitative conclusions suggest that benefits of integration are greater when deferred demand exceeds express demand. This insight helps to explain the different business strategies of package delivery firms today. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(3), 183–196 2007
On tree 3‐spanners in directed path graphs
Authors: Panda B.S. , Das Anita 
Published: July 2007

AbstractA spanning tree T of a graph G is said to be a tree t‐spanner if the distance between any two vertices in T is at most t times their distance in G. While the complexity of the problem of recognizing whether a graph has a tree t‐spanner is known for any fixed t≠3, the case t = 3 is still open. H.‐O. Le and V. B. Le (1999, Networks, 34(2), 81‐87) have shown that every directed path graph admits a tree 3‐spanner by proposing an algorithm to construct a tree 3‐spanner of a given directed path graph. In this paper, we point out a flaw in their algorithm by producing a directed path graph for which their algorithm fails to produce a tree 3‐spanner although the graph admits a tree 3‐spanner. Furthermore, we show that directed path graphs need not admit tree 3‐spanners in general. Next, we show that directed path graphs of diameter two always admit tree 2‐spanners and hence tree 3‐spanners. Finally, we show that a tree 2‐spanner of a diameter two directed path graph can be constructed in linear time. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(3), 203–210 2007
Patient involvement in health‐related decisions during prolonged critical illness
Authors: Happ Mary Beth , Swigart Valerie A. , Tate Judith A. , Hoffman Leslie A. , Arnold Robert M. 
Published: July 2007

AbstractWe describe patterns of communication of patients involved in health‐related decision making during prolonged mechanical ventilation (PMV). Data were collected using observation, interview, and record review. Twelve of 30 patients participated in decisions about initiating, withdrawing, and withholding life‐sustaining treatment, surgery, artificial feeding, financial/legal issues, discharge care, and daily care procedures. Patient involvement was largely validation or confirmation of what clinicians and families had already decided. Patients' participation was enlisted by clinicians and family members even when the patients did not exhibit full decisional capacity. Patient involvement in health‐related decisions during prolonged critical illness is a shared and negotiated process that requires continued empirical study and ethical analysis. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:361–372, 2007.
Is the CVI an acceptable indicator of content validity? Appraisal and recommendations
Authors: Polit Denise F. , Beck Cheryl Tatano , Owen Steven V. 
Published: July 2007

AbstractNurse researchers typically provide evidence of content validity for instruments by computing a content validity index (CVI), based on experts' ratings of item relevance. We compared the CVI to alternative indexes and concluded that the widely‐used CVI has advantages with regard to ease of computation, understandability, focus on agreement of relevance rather than agreement per se, focus on consensus rather than consistency, and provision of both item and scale information. One weakness is its failure to adjust for chance agreement. We solved this by translating item‐level CVIs (I‐CVIs) into values of a modified kappa statistic. Our translation suggests that items with an I‐CVI of .78 or higher for three or more experts could be considered evidence of good content validity. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:459–467, 2007.
Staff–family relationships in the care of older people: A report on a systematic review
Authors: Haesler Emily , Bauer Michael , Nay Rhonda 
Published: July 2007

AbstractThis article reports on a systematic review of the strategies, practices, and organizational characteristics that promote constructive staff–family relationships in the care of older adults in the health care setting. Research evidence points to the need to address power and control issues, communication, and collaborative approaches to care. Interventions designed to promote family–staff relationships are more likely to achieve maximum benefit when implemented with accompanying information sharing, education, and managerial support. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:385–398, 2007.
Using standardized survey items with older adults hospitalized for chronic illness
Authors: Fox Mary T. , Sidani Souraya , Streiner David 
Published: July 2007

AbstractWe used the stages of the question response model as a framework to discuss the challenges in administering standardized measures to older adults hospitalized with chronic illnesses. Items with complex content and those with negative stems were associated with difficulties during the comprehension stage. Present experience with the subject of the item was a barrier to retrieving past experiences. The lack of relevance of an item's content to the respondent's situation was associated with problems during the judgment stage. The numeric response format of the items was an obstacle during the response stage. Strategies to enhance the validity of the surveys included breaking up, rephrasing, and contextualizing items, and using descriptive response options. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:468–481, 2007.
Using crash scene variables to predict the need for trauma center care in older persons
Authors: Scheetz Linda J. , Zhang Juan , Kolassa John E. 
Published: July 2007

AbstractCurrent trauma triage protocols lack sensitivity to occult injuries in older persons, resulting in unacceptable undertriage rates. We identified crash scene information that could be used by emergency personnel to identify the need for trauma center care in older persons injured in motor vehicle crashes. Crash records of 7,883 persons 65 years and older were explored using classification and regression trees (CART) analysis. CART analysis of 26 crash scene variables resulted in two classification trees from which triage decision rules were stated for persons with severe and moderate injuries. Sensitivity and specificity of the rules were 95.15% and 76.47% for severe injury and 83.1% and 81.5% for moderate injury. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:399–412, 2007
Nurse adherence to a minimal‐contact smoking cessation intervention on cardiac wards
Authors: Segaar Dewi , Willemsen Marc C. , Bolman Catherine , De Vries Hein 
Published: July 2007

AbstractHealth promotion interventions are often underused by care practitioners and, therefore, are not effective. In this study, we assessed nurses' use of a smoking cessation intervention in Dutch cardiac wards and factors associated with their adherence. Ninety‐four of 206 nurses did not fully apply the intervention in daily practice; they did not always provide patients with self‐help guides, discuss smoking cessation aids, or provide follow‐up care. The significant factors in our integrated change model accounted for 52% of the variance in adherence. Adherence was most likely if nurses consistently used an intervention card, perceived advantages of the intervention, had other nurses around them who used it, and had been involved in decision‐making. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:429–444, 2007.