bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small tourism business research change and evolution
Authors: Morrison Alison , Carlsen Jack , Weber Paul 
Published: May 2010

AbstractThe paper critically reflects on key knowledge contributions that coalesce to inform contemporary understanding of the phenomenon of small tourism business. The purpose is to scrutinise change and evolution in perspectives and how these impact on what knowledge is disclosed and what is not. Conventionally accepted wisdom is challenged, indoctrinated presuppositions are questioned, and research methodological advancements are offered. This is achieved through a comprehensive review and critical‐reflective analysis of key academic contributions spanning a period of approximately 35 years. The value is to stimulate criticality relative to what constitutes ‘truth’ within the given context and to inspire fresh research perspectives. Conclusions are drawn regarding future research directions. Furthermore, informed by thorough analysis of the content of the paper, five guiding research principles provide an appropriate conclusion. Copyright © 2010 John Wiley & Sons, Ltd.
Institutionally based health care workers' exposure to traumatogenic events: Systematic review of PTSD presentation
Authors: Robertson Noelle , Perry Andrew 
Published: May 2010

AbstractThis review sought to identify published evidence for the presentation of posttraumatic stress disorder (PTSD) symptoms in institutionally based health care workers. The databases Medline, Psycinfo, PILOTS, CINAHL (R), EMBASE, and ISI Web of Science were searched in a systematic manner eliciting 9 quantitative studies. Presentation of PTSD among such workers appears comparable to data reported for emergency services staff. The authors discuss some of the theoretical debates underpinning the research as well as methodological weaknesses that temper the strength of conclusions drawn.
Accurate Elemental Analysis of Metal‐Containing Polymer Latexes Using ICP‐Optical Emission Spectrometry
Authors: Vogel Nicolas , Hauser Christoph P. , Schuller Kilian , Landfester Katharina , Weiss Clemens K. 
Published: May 2010

AbstractThe use of ICP‐OES to determine the metal content of metal‐complex‐containing colloidal dispersions is explored. Colloidal dispersions containing a defined amount of metal complex were produced by miniemulsion polymerization. It was found that simple ICP‐OES measurements yielded apparent metal concentrations significantly below the expected value. To examine the behavior of the colloidal dispersions in the ICP spectrometer, a systematic study on measurement conditions was performed. It was found that the addition of a surfactant to both colloidal dispersions and standards led to measured metal contents close to the theoretical value. Most reliable results were obtained using SDS in concentrations above the cmc.magnified image
Molecular dynamics of the blood–testis barrier components during murine spermatogenesis
Authors: Chihara Masataka , Otsuka Saori , Ichii Osamu , Hashimoto Yoshiharu , Kon Yasuhiro 
Published: May 2010

AbstractThe blood–testis barrier (BTB) separates the seminiferous epithelium into the adluminal and basal compartments. During murine spermatogenesis, preleptotene/leptotene spermatocytes migrate from the basal to the adluminal compartment through the BTB during stages VIII–IX. In the present study, we focused on the tight junction (TJ) molecules and analyzed their spatiotemporal expression during the murine seminiferous epithelial cycle. Structural analysis revealed that the principal components of the BTB, for example, claudin‐3, claudin‐11, occludin, and zonula occludens‐1 (ZO‐1), were localized at the basal and luminal sides of the preleptotene/leptotene spermatocytes during the migration stages (VIII–IX). Although we detected claudin‐11, occludin, and ZO‐1 throughout spermatogenesis, claudin‐3 was only detected during stages VI–IX. Quantitative PCR using dissected seminiferous tubules from three stages (Early: II–VI, Middle: VII–VIII, Late: IX–I) clarified that the mRNA levels of TJ molecules were not correlated with the histoplanimetrical protein levels during spermatogenesis. Additionally, tubulobulbar complexes, considered to be involved in the internalization of TJ, were observed at the BTB site. Furthermore, a significant reduction in the mRNA levels of genes for the degradation of occludin (Itch) and endocytic recycling (Rab13) were observed during the Late and Middle stages, respectively. Therefore, we hypothesized that the lag between mRNA and protein expression of TJ molecules may be due to posttranslational modulation, for example, tubulobulbar complexes and endocytic recycling processes. In conclusion, these findings indicate that the integrity of the BTB is maintained throughout spermatogenesis, and the stage‐specific localization of claudin‐3 protein plays an important role in regulating BTB permeability. Mol. Reprod. Dev. 77: 630–639, 2010. © 2010 Wiley‐Liss, Inc.
Reproducibility of quantitative magnetization‐transfer imaging parameters from repeated measurements
Authors: Levesque Ives R. , Sled John G. , Narayanan Sridar , Giacomini Paul S. , Ribeiro Luciana T. , Arnold Douglas L. , Pike G. Bruce 
Published: May 2010

AbstractQuantitative magnetization‐transfer imaging methods provide in vivo estimates of parameters of the two‐pool model for magnetization‐transfer in tissue. The goal of this study was to evaluate the reproducibility of quantitative magnetization‐transfer imaging parameter estimates in healthy subjects. Magnetization‐transfer–weighted and T1 relaxometry data were acquired in five healthy subjects at multiple time points, and the variability of the resulting fitted magnetization‐transfer parameters was evaluated. The impact of subsampling the magnetization‐transfer data and correcting field inhomogeneities was also evaluated. The key parameters measured in this study had an average variability, across time points, of 4.7% for the relative size of the restricted pool (F), 7.3% for the forward exchange constant (kf), 1.9% for the free pool spin‐lattice relaxation constant (R1f), 4.5% for the T2 of the free pool (T2f), and 2.3% for the T2 of the restricted pool (T2r). Our findings show that serial quantitative magnetization‐transfer imaging experiments can be performed reliably, with good reproducibility of the model parameter estimates, and demonstrate the reproducibility of acquisition schemes with fewer magnetization‐transfer contrasts. This establishes the feasibility of this technique for monitoring patients affected by degenerative white matter diseases while providing critical data to estimate the statistical power of such studies. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Quantitative sodium imaging with a flexible twisted projection pulse sequence
Authors: Lu Aiming , Atkinson Ian C. , Claiborne Theodore C. , Damen Frederick C. , Thulborn Keith R. 
Published: May 2010

AbstractThe quantification of sodium MR images from an arbitrary intensity scale into a bioscale fosters image interpretation in terms of the spatially resolved biochemical process of sodium ion homeostasis. A methodology for quantifying tissue sodium concentration using a flexible twisted projection imaging sequence is proposed that allows for optimization of tradeoffs between readout time, signal‐to‐noise ratio efficiency, and sensitivity to static field susceptibility artifacts. The gradient amplitude supported by the slew rate at each k‐space radius regularizes the readout gradient waveform design to avoid slew rate violation. Static field inhomogeneity artifacts are corrected using a frequency‐segmented conjugate phase reconstruction approach, with field maps obtained quickly from coregistered proton imaging. High‐quality quantitative sodium images have been achieved in phantom and volunteer studies with real isotropic spatial resolution of 7.5 × 7.5 × 7.5 mm3 for the slow T2 component in ∼8 min on a clinical 3‐T scanner. After correcting for coil sensitivity inhomogeneity and water fraction, the tissue sodium concentration in gray matter and white matter was measured to be 36.6 ± 0.6 μmol/g wet weight and 27.6 ± 1.2 μmol/g wet weight, respectively. Magn Reson Med 63:1583–1593, 2010. © 2010 Wiley‐Liss, Inc.
Assessment of synovitis in the osteoarthritic knee: Comparison between manual segmentation, semiautomated segmentation, and semiquantitative assessment using contrast‐enhanced fat‐suppressed T1‐weighted MRI
Authors: Fotinos‐Hoyer Amber Kassel , Guermazi Ali , Jara Hernán , Eckstein Felix , Ozonoff Al , Khard Hussain , Norbash Alexander , Bohndorf Klaus , Roemer Frank W. 
Published: May 2010

AbstractOsteoarthritic joints regularly exhibit synovitis, which is ideally assessed on contrast‐enhanced MRI. Manual segmentation is the reference standard for volumetric analysis but is labor intensive. The aim was to evaluate alternative semiautomated approaches of targeted thresholding and gaussian deconvolution. Volumetric and semiquantitative synovitis assessment was compared in addition. Thirty‐two knees with osteoarthritis were scanned on a 1.5‐T system. Synovitis volumes were plotted against each other and distributions fit with linear functions. The relationship between semiquantitative scores and synovitis volumes was assessed using Spearman's correlation coefficient. Semiautomated volume measurement was more time efficient than manual segmentation and showed a high correlation with manual analysis (R2 = 0.88 and 0.82). Manual segmentation was correlated with summed and with maximum semiquantitative synovitis scores (ρ = 0.71 and 0.47). In conclusion, semiautomated analysis provides comparable quantitative results when compared to manual segmentation but is approximately five times more time efficient. Semiquantitative assessment adds anatomic information on synovitis distribution. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
A simple method for rectified noise floor suppression: Phase‐corrected real data reconstruction with application to diffusion‐weighted imaging
Authors: Prah Douglas E. , Paulson Eric S. , Nencka Andrew S. , Schmainda Kathleen M. 
Published: May 2010

AbstractDiffusion‐weighted MRI is an intrinsically low signal‐to‐noise ratio application due to the application of diffusion‐weighting gradients and the consequent longer echo times. The signal‐to‐noise ratio worsens with increasing image resolution and diffusion imaging methods that use multiple and higher b‐values. At low signal‐to‐noise ratios, standard magnitude reconstructed diffusion‐weighted images are confounded by the existence of a rectified noise floor, producing poor estimates of diffusion metrics. Herein, we present a simple method of rectified noise floor suppression that involves phase correction of the real data. This approach was evaluated for diffusion‐weighted imaging data, obtained from ethanol and water phantoms and the brain of a healthy volunteer. The parameter fits from monoexponential, biexponential, and stretched‐exponential diffusion models were computed using phase‐corrected real data and magnitude data. The results demonstrate that this newly developed simple approach of using phase‐corrected real images acts to reduce or even suppress the confounding effects of a rectified noise floor, thereby producing more accurate estimates of diffusion parameters. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Phase‐based arterial input function measurements for dynamic susceptibility contrast MRI
Authors: Bleeker Egbert J. W. , van Buchem Mark A. , Webb Andrew G. , van Osch Matthias J. P. 
Published: May 2010

AbstractIn dynamic susceptibility contrast perfusion MRI, arterial input function (AIF) measurements using the phase of the MR signal are traditionally performed inside an artery. However, phase‐based AIF selection is also feasible in tissue surrounding an artery such as the middle cerebral artery, which runs approximately perpendicular to B0 since contrast agents also induce local field changes in tissue surrounding the artery. The aim of this study was to investigate whether phase‐based AIF selection is better performed in tissue just outside the middle cerebral artery than inside the artery. Additionally, phase‐based AIF selection was compared to magnitude‐based AIF selection. Both issues were studied theoretically and using numerical simulations, producing results that were validated using phantom experiments. Finally, an in vivo experiment was performed to illustrate the feasibility of phase‐based AIF selection. Three main findings are presented: first, phase‐based AIF selections are better made in tissue outside the middle cerebral artery, rather than within the middle cerebral artery, since in the latter approach partial‐volume effects affect the shape of the estimated AIF. Second, optimal locations for phase‐based AIF selection are similar for different clinical dynamic susceptibility contrast MRI sequences. Third, phase‐based AIF selection allows more locations in tissue to be chosen that show the correct AIF than does magnitude‐based AIF selection. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Optimized inversion recovery sequences for quantitative T1 and magnetization transfer imaging
Authors: Li Ke , Zu Zhongliang , Xu Junzhong , Janve Vaibhav A. , Gore John C. , Does Mark D. , Gochberg Daniel F. 
Published: May 2010

AbstractInversion recovery sequences that vary the inversion time (ti) have been employed to determine T1 and, more recently, quantitative magnetization transfer parameters. Specifically, in previous work, the inversion recovery pulse sequences varied ti only while maintaining a constant delay (td) between repetitions. T1 values were determined by fitting to a single exponential function, and quantitative magnetization transfer parameters were then determined by fitting to a biexponential function with an approximate solution. In the current study, new protocols are employed, which vary both ti and td and fit the data with minimal approximations. Cramer‐Rao lower bounds are calculated to search for acquisition schemes that will maximize the precision efficiencies of T1 and quantitative magnetization transfer parameters. This approach is supported by Monte Carlo simulations. The optimal T1 schemes are verified by measurements on MnCl2 samples. The optimal quantitative magnetization transfer schemes are confirmed by measurements on a series of cross‐linked bovine serum albumin phantoms of varying concentrations. The effects of varying the number of sampling data points are also explored, and a rapid acquisition scheme is demonstrated in vivo. These new optimized quantitative imaging methods provide an improved means for determining T1 and magnetization transfer parameter values compared to previous inversion recovery based methods. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
3D undersampled golden‐radial phase encoding for DCE‐MRA using inherently regularized iterative SENSE
Authors: Prieto Claudia , Uribe Sergio , Razavi Reza , Atkinson David , Schaeffter Tobias 
Published: May 2010

AbstractOne of the current limitations of dynamic contrast‐enhanced MR angiography is the requirement of both high spatial and high temporal resolution. Several undersampling techniques have been proposed to overcome this problem. However, in most of these methods the tradeoff between spatial and temporal resolution is constant for all the time frames and needs to be specified prior to data collection. This is not optimal for dynamic contrast‐enhanced MR angiography where the dynamics of the process are difficult to predict and the image quality requirements are changing during the bolus passage. Here, we propose a new highly undersampled approach that allows the retrospective adaptation of the spatial and temporal resolution. The method combines a three‐dimensional radial phase encoding trajectory with the golden angle profile order and non‐Cartesian Sensitivity Encoding (SENSE) reconstruction. Different regularization images, obtained from the same acquired data, are used to stabilize the non‐Cartesian SENSE reconstruction for the different phases of the bolus passage. The feasibility of the proposed method was demonstrated on a numerical phantom and in three‐dimensional intracranial dynamic contrast‐enhanced MR angiography of healthy volunteers. The acquired data were reconstructed retrospectively with temporal resolutions from 1.2 sec to 8.1 sec, providing a good depiction of small vessels, as well as distinction of different temporal phases. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
GRAPPA operator for wider radial bands (GROWL) with optimally regularized self‐calibration
Authors: Lin Wei , Huang Feng , Li Yu , Reykowski Arne 
Published: May 2010

AbstractA self‐calibrated parallel imaging reconstruction method is proposed for azimuthally undersampled radial dataset. A generalized auto‐calibrating partially parallel acquisition (GRAPPA) operator is used to widen each radial view into a band consisting of several parallel lines, followed by a standard regridding procedure. Self‐calibration is achieved by regridding the central k‐space region, where Nyquist criterion is satisfied, to a rotated Cartesian grid. During the calibration process, an optimal Tikhonov regularization factor is introduced to reduce the error caused by the small k‐space area of the self‐calibration region. The method was applied to phantom and in vivo datasets acquired with an eight‐element coil array, using 32‐64 radial views with 256 readout samples. When compared with previous radial parallel imaging techniques, GRAPPA operator for wider radial bands (GROWL) provides a significant speed advantage since calibration is carried out using the fully sampled k‐space center. A further advantage of GROWL is its applicability to arbitrary‐view angle ordering schemes. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
23Na and 2H magnetic resonance studies of osteoarthritic and osteoporotic articular cartilage
Authors: Keinan‐Adamsky Keren , Shinar Haddasah , Shabat Shay , Brin Yaron S. , Nyska Meir , Navon Gil 
Published: May 2010

AbstractIn this study, the short component of the 23Na T2 (T2f) and the 23Na and 2H quadrupolar interactions (νQ) were measured in bone‐cartilage samples of osteoarthritic (OA) and osteoporotic (OP) patients. 23Na νQ was found to increase in osteoarthritic articular cartilage relative to controls. Similar results were found in bovine cartilage following proteoglycan (PG) depletion, a condition that prevails in osteoarthritis. 23Na νQ and 1/T2f for articular cartilage obtained from osteoporotic patients were significantly larger than for control and osteoarthritic cartilage. Decalcification of both human and bovine articular cartilage resulted in an increase of 23Na νQ and 1/T2f, showing the same trend as the osteoporotic samples. Differences in the ratio of the intensity of the large 2H splitting to that of the small one in the calcified zone were also observed. In osteoporosis, this ratio was twice as large as that obtained for both control and osteoarthritic samples. The 2H and 23Na results can be interpreted as due to sodium ions and water molecules filling the void created by the calcium depletion and to calcium ions being located in close association with the collagen fibers. To the best of our knowledge, this is the first study reporting differences of NMR parameters in cartilage of osteoporotic patients. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Stabilization of jump linear systems with mode‐dependent time‐varying delays
Authors: Zhao Xudong , Zeng Qingshuang 
Published: May 2010

AbstractThis paper deals with the stabilization problems for a class of Markovian jump systems with time delays which are time varying and depending on system mode. Following the recent study on the class of systems, improved sufficient condition for stochastic stability of the underlying systems is derived by constructing a different Lyapunov–Krasovskii functional. Basing on this new criterion, a stabilization algorithm through memory state feedback controller is designed. Illustrative numerical examples are provided to demonstrate the effectiveness of the proposed approaches. Copyright © 2010 John Wiley & Sons, Ltd.
Intracavitary cisplatin therapy for pediatric malignancies
Authors: Katzenstein Howard M. , Petricca Sarah , Ricketts Richard , Wasilewski‐Masker Karen , Powell Christie , Rapkin Louis , George Bradley , Woods William G. , Olson Thomas A. 
Published: May 2010

AbstractBackgroundLocal control is essential for the successful treatment of pediatric solid tumors. Complete excision is often not possible and local control therapies are limited. Intracavitary cisplatin (IC‐CDDP) may be utilized to supplement local control. The aim of the study was to determine the toxicity and efficacy of locally instilled intracavitary cisplatin in patients with recurrent tumors in closed body cavities.ProcedureFrom 2001 to 2009, 12 patients (1–20 years) with recurrent or unresectable malignant tumors were treated with IC‐CDDP. Nine had pulmonary lesions. Three patients had abdominal tumors. CDDP (200 mg/m2) was instilled by chest tube or Tenckhoff catheter. Patients were shifted every 15–30 min to allow distribution. After 4 hr, residual was drained by gravity. In 10/13 courses, sodium thiosulfate (STS) was administered to prevent nephrotoxicity. Three other patients received amifostine.ResultsMalignant pleural effusions resolved in 5/7 patients. This response was temporary in three patients. No patients had ascites prior to treatment. Three patients are alive and disease‐free, 18 months, 4 years, and 6 years from treatment. They also had surgery and chemotherapy. Transient renal toxicity was noted in most patients. One patient, treated with amifostine, had persistent renal dysfunction.ConclusionsIC‐CDDP was effective in treating malignant pleural effusions and may be a palliative option for refractory disease. Long‐term survival was achieved in two patients, treated at first diagnosis. The benefit of IC‐CDDP in these patients is difficult to assess. Renal dysfunction is usually mild, and typically resolves, but warrants preventive measures with IC‐CDDP therapy. Pediatr Blood Cancer. 2010;55:452–456. © 2010 Wiley‐Liss, Inc.
Impact of continuous renal replacement therapy on oxygenation in children with acute lung injury after allogeneic hematopoietic stem cell transplantation
Authors: Elbahlawan Lama , West Nancy K. , Avent Yvonne , Cheng Cheng , Liu Wei , Barfield Raymond C. , Jones Deborah P. , Rajasekaran Surender , Morrison R. Ray 
Published: May 2010

AbstractBackgroundAcute lung injury (ALI) continues to carry a high mortality rate in children after allogeneic hematopoietic stem cell transplant (HSCT). Continuous renal replacement therapy (CRRT) is often used for these patients for various indications including renal failure and fluid overload, and may have a beneficial effect on oxygenation and survival. Therefore, we sought to determine the effect of CRRT on oxygenation in mechanically ventilated pediatric allogeneic HSCT patients with ALI, and to document survival to intensive care unit discharge in this at‐risk population receiving both mechanical ventilation and CRRT.ProcedureRetrospective analysis of a pediatric allogeneic HSCT cohort admitted to intensive care unit of a single pediatric oncology center from 1994 to 2006 who received CRRT during a course of mechanical ventilation for ALI.ResultsThirty post‐HSCT mechanically ventilated children with ALI who underwent CRRT were included. There was a significant improvement in PaO2/FiO2 with median increase of 31 and 43 in the 24 and 48 hr intervals after initiation of CRRT compared with the 24 hr interval before CRRT (P = 0.0008 and 0.0062, respectively). This improvement in PaO2/FiO2 correlated significantly with reduction of fluid balance achieved after initiation of CRRT (P = 0.0001). There was a trend not reaching statistical significance in improvement in mean airway pressure 48 hr after CRRT in survivors compared to non‐survivors.ConclusionsCRRT improved oxygenation in mechanically ventilated pediatric allogeneic HSCT patients with ALI. Pediatr Blood Cancer. 2010;55:540–545. © 2010 Wiley‐Liss, Inc.