bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cine MR fourier velocimetry of blood flow through cardiac valves: Comparison with doppler echocardiography
Authors: Mohiaddin Raad H. , Gatehouse Peter D. , Henien Michael , Firmin David N. 
Published: March 2007

AbstractNoninvasive measurement of blood flow velocity through the cardiac valves has important clinical applications. A wide variety of MR methods are available for flow measurement. The aim of this study was to investigate the ability of cine MR Fourier velocimetry to measure flow through healthy cardiac valves and to compare MR and Doppler peak velocity measurements. Ten healthy volunteers (age mean ± SD, 24 ± 4 years) without history of valvular disease were studied. Four of the subjects were females. In each subject, aortic, pulmonary, mitral, and tricuspid valves were evaluated with MR and Doppler imaging. A whole‐body mobile MR machine was used, operating at .5‐T with actively shielded magnetic field gradient coils on all three axes capable of 20 mT/m at a slew rate of 60 mT/m/msec. The heart rate during MR and Doppler studies was not significantly different. The mean difference between the two studies was 2 beats/min, with a 95% confidence interval of −22 beats/min, +25 beats/min. Peak systolic flow velocity in the aortic and pulmonary valves and peak diastolic flow velocity in the mitral and tricuspid valves measured with MRI and Doppler echocardiography correlated well. The mean difference between the two measurements (MR — Doppler) was 63 mm/sec, with a 95% confidence interval of −180 mm/sec, +310 mm/sec. The agreement between two observers interpreting the same MR velocity maps was close. The mean difference between their two measurements was 23 mm/sec, with a 95% confidence interval of −20 mm/sec, +60 mm/sec. There was no significant difference between MR and Doppler imaging or between the two MR observers. MR Fourier velocimetry has the necessary ease, reliability, and speed to measure blood flow through the cardiac valves, although measurement of late diastolic flow in the atrioventricular valves is limited. Measurement of peak blood velocity through the cardiac valves by this method showed satisfactory agreement with Doppler, but its clinical application for assessing diseased cardiac valves must be established.
MR velocity mapping of tricuspid flow: Correction for through‐plane motion
Authors: Kayser Hein W. M. , Stoel Berend C. , Van Der Wall Ernst E. , Van Geest Rob J. Der , De Roos Albert 
Published: March 2007

AbstractWe evaluated the effect of through‐plane motion on tricuspid flow measurements performed with MR velocity mapping in nine normal subjects and 15 patients with possible right ventricular (RV) disease. Eight parameters of RV diastolic function were derived from the tricuspid flow measurements, both before and after a correction for through‐plane motion. Measurements of E‐peak, A‐peak, and time‐to‐peak filling rate changed significantly after correction for through‐plane motion (P < .05). Tricuspid flow as a marker of RV diastolic function should be corrected for the effect of throughplane motion to improve functional evaluation of the RV.
Comparison of fat‐saturation fast spin echo versus conventional spin‐echo MRI in the detection of rotator cuff pathology
Authors: Needell Steven D. , Zlatkin Michael B. 
Published: March 2007

AbstractThe purpose of this study was to compare the diagnostic performance of fat‐saturation fast‐spin‐echo (FSE) T2‐weighted (T2W) sequences with conventional spin‐echo (CSE) T2W sequences in the detection of rotator cuff pathology using surgery as the reference standard. Oblique coronal dual‐echo CSE and FSE T2W images with fat saturation from 50 surgically confirmed MR shoulder examinations were acquired on a 1.5‐T MR scanner. Blinded MR readers retrospectively analyzed each imaging sequence separately and ultimately correlated both sequences together with findings at surgery. FSE was 100% sensitive and 94% specific in detection of full‐thickness tears (n = 19) and 73% sensitive and 97% specific in the detection of partial‐thickness rotator cuff tears (n = 13). There was no statistically significant difference in the performance of FSE with fat saturation compared with CSE. The two discrepancies between imaging sequences related to the extent of partial‐thickness tears. Our findings suggest that fat‐saturation FSE imaging can effectively replace CSE imaging in the evaluation of rotator cuff pathology.
Dynamic MRI of a hypovascularized liver tumor model: Comparison of a new blood pool contrast agent (24‐gadolinium‐DTPA‐cascade‐polymer) with gadopentetate dimeglumine
Authors: Tacke Josef , Adam Gerhard , Claßen Holger , Mühler Andreas , Prescher Andreas , Günther Rolf W. 
Published: March 2007

AbstractWe evaluated the enhancement properties of a new blood pool contrast agent (24‐gadolinium‐diethylene‐triamine pentaacetic acid [Gd‐DTPA]‐cascade‐polymer) in comparison with gadopentetate dimeglumine in 24 rabbits with an experimentally induced VX‐2 liver tumor. Dynamic MRI of the liver was performed before, immediately after, and within 15 seconds to 30 minutes after contrast agent administration. Relative signal intensities and contrast‐to‐noise ratios (CNRs) of both agents were evaluated. After blood pool agent administration, a significantly higher CNR between liver and tumor was observed within 2 to 30 minutes after injection as compared with the CNR after gadopentetate dimeglumine. Within 4 to 30 minutes after injection of gadopentetate dimeglumine, the relative signal intensities of tumor were significantly higher than after administration of the blood pool agent. In conclusion, the new blood pool contrast agent demonstrated a significantly better CNR of the experimental hypovascularized liver tumor than gadopentetate dimeglumine.
Experimental hepatic dysfunction: Evaluation by MRI with Gd‐EOB‐DTPA
Authors: Kim Tonsok , Murakami Takamichi , Hasuike Yasunori , Gotoh Mitsukazu , Kato Naoki , Takahashi Masaya , Miyazawa Tomoaki , Narumi Yoshifumi , Monden Morito , Nakamura Hironobu 
Published: March 2007

AbstractTo investigate the potential of gadolinium (Gd)‐ethoxybenzyl (EOB)‐diethylenetriamine‐pentaacetic acid (DTPA) for evaluating liver function, chemically induced hepatitis animal models were studied. The rats in group 1 underwent intraperitoneal administration of 2.0 ml/kg and those in group 2 underwent intraperitoneal administration of .5 ml/kg of 50% (V/V) carbon tetrachloride (CCl4) solution. The rats in group 3 served as controls. For rats of each group, the signal intensity of the liver was measured on T1‐weighted spin‐echo MR images acquired before and until 60 minutes after an intravenous injection of Gd‐EOB‐DTPA. The remaining rats in each group underwent indocyanine green test, serologic examination, or measurement of prothrombin time. Liver enhancement was compared with results of the other examinations. The degree of liver enhancement with Gd‐EOB‐DTPA was decreased and the washout of contrast was prolonged in the CCl4‐administered groups. In this animal model, both hepatic dysfunction and liver enhancement were dose‐dependent. MRI with Gd‐EOB‐DTPA has the potential to evaluate hepatic function.
Host country nationals as socializing agents: a social identity approach
Authors: Toh Soo Min , DeNisi Angelo S. 
Published: March 2007

AbstractA major challenge facing Multinational Enterprises (MNEs) is finding ways to increase the success rates of managers assigned overseas. Our paper draws upon social identity theory to develop a model that focuses on the role of host country nationals (HCNs) in determining the adjustment of expatriate managers. Specifically, our model proposes attributes of the expatriate and the HCN that can increase the salience of national identity and outgroup categorization of expatriates by the HCNs. We also suggest how outgroup categorization interacts with a number of situational factors to influence the role of HCNs as socializing agents for expatriate newcomers. Finally, we propose that the socializing behaviors HCNs may display or withhold from the expatriate will affect the adjustment of the expatriate. Our model highlights the often‐overlooked partners in the expatriate adjustment process and emphasizes the need for MNEs to be cognizant of the social dynamics between HCNs and expatriates in the host location. Copyright © 2007 John Wiley & Sons, Ltd.
A model of dual organizational identification in the context of the multinational enterprise
Authors: Vora Davina , Kostova Tatiana 
Published: March 2007

AbstractIntegrating organizational behavior research on Social Identity Theory (SIT), Self‐Categorization Theory (SCT), and organizational identification with international management research, we develop a model of dual organizational identification (DOI) for subsidiary managers in multinational enterprises (MNEs). We conceptualize the DOI construct in terms of relative magnitude and form and then present a model that specifies a set of contextual antecedents at the organizational and country levels of analysis as well as individual and organizational level consequences related to subsidiary manager role issues. Specifically, we suggest that type of MNE impacts the relative magnitude of DOI, while type of MNE, cultural distance, and institutional distance affect the form of DOI. In turn, relative magnitude of DOI is posited to impact fulfillment of subsidiary manager roles, subsidiary‐parent cooperation, and knowledge transfer. Form of DOI affects the experience of role conflict by subsidiary managers. We conclude with a discussion of the contribution of our model to the organizational behavior and international management literatures, its implications for research, and some possible theoretical extensions. Copyright © 2007 John Wiley & Sons, Ltd.
Sensitivity of Alpine snow cover to European temperature
Authors: Hantel Michael , Hirtl‐Wielke Lucia‐Maria 
Published: March 2007

AbstractThe number of days with snow cover at 268 Alpine climate stations in the winters of 1961–2000 has been investigated with respect to the mean winter temperature over Europe. The corresponding description, originally developed for Austria and recently applied to Switzerland, consists in fitting a logistic curve to the observed data. The slope of this curve, originally the hyperbolic tangent function, is interpreted as the sensitivity of the snow duration‐temperature relationship.Here we first demonstrate with a physical‐statistical model that the proper logistic curve is not the hyperbolic tangent, but the error function, generated through the pdf of the fluctuating temperature; the slope of this curve is inversely proportional to the standard deviation of temperature. Since the station temperature used for this local model is on a scale much too small for global climate models, we simulate, secondly, the temperature with the concept of the Alpine temperature: It is the spatial Taylor expansion of the seasonal European temperature in vertical and horizontal directions. This improved model yields, for the same Austrian and Swiss data, both a better fit and a slightly smaller sensitivity of the snow‐temperature curve than the original hyperbolic model.Thirdly we apply our improved model to a considerably larger Alpine data set comprising also data from France, Germany, Italy and Slovenia and find a sensitivity of about − 0.33 ( ± 0.03) per degree warming. It is representative for the entire Alpine region and corresponds to a maximum reduction of the snow cover of 30 days in winter at a height of 700 m for 1° European warming. The implication is that the relation between the natural fluctuations of winter snow duration and European temperature may be an estimate for a trend of snow duration in case of a future European temperature trend. Copyright © 2007 Royal Meteorological Society
Texas Children's Hospital makes leadership development a core business strategy
Authors: Aldred Linda 
Published: March 2007

AbstractEven an admirable culture can have its dark side, and convincing current leaders that leadership is the problem is a task best not taken lightly. Texas Children's Hospital rose to the challenge with creative ways for building an enduring commitment to change, and for infusing leadership development into leaders' psyches and practices. Guiding principles and success profiles now link mission and values with the day‐to‐day expectations for employees, and are fully integrated into measurement, performance management, and selection systems. Powerful new tools and resources are helping build leadership competencies at all levels. Lower turnover and greater employee satisfaction are just the first indicators of the success of the initiative. © 2007 Wiley Periodicals, Inc.
The twenty‐first century leader: Social artist, spiritual visionary, and cultural innovator
Authors: Karakas Fahri 
Published: March 2007

AbstractThe old leadership model is giving way to a new twenty‐first‐century paradigm for navigating in an age of uncertainty, complexity, interdependency, globalization, and accelerating change. Drawing from chaos theory, nonlinear dynamics, quantum mechanics, and other disciplines, the author sees the emergence of three new creative roles for leaders—social artist, spiritual visionary, and cultural innovator—which call for a new leadership mindset, and for tapping the powers of the heart. A new holistic skill set with eleven domains encompasses the values, perspectives, and competencies needed to lead organizations and employees to their full potential in the new century. © 2007 Wiley Periodicals, Inc.
Identification of berberine in ancient and historical textiles by surface‐enhanced Raman scattering
Authors: Leona Marco , Lombardi John R. 
Published: March 2007

AbstractThe highly fluorescent natural dye berberine can be easily identified in microscopic textile samples by surface‐enhanced Raman spectroscopy employing citrate‐reduced Ag colloid. The ordinary Raman (OR) and SERS spectra of berberine are presented and discussed in the light of a DFT calculation. Using FT‐Raman and FT‐SERS we could reliably compare relative intensity shifts and investigate the adsorption geometry of berberine on Ag nanoparticles. The significant enhancement in the FT‐SERS spectrum of the out‐of‐plane ring system bending deformation mode at 729 cm−1 relative to a group of in‐plane vibrations at around 1500 cm−1 was interpreted as evidence of a ‘flat‐on’ adsorption geometry. SERS was successfully used to identify berberine in silk fiber samples coated with colloidal Ag following a pretreatment with HCl vapor. The SERS method allowed us to detect berberine in a microscopic sample of a single silk fiber from a severely degraded and soiled 17th Century Chinese textile fragment. Copyright © 2007 John Wiley & Sons, Ltd.
Experimental and computational studies on the solvation of lithium tetrafluorobrate in dimethyl sulfoxide
Authors: Xuan Xiaopeng , Wang Jianji , Zhao Yang , Zhu Jianjun 
Published: March 2007

AbstractSolvation structures of the lithium cation and tetrafluorobrate anion in dimethyl sulfoxide (DMSO) were investigated by Raman spectroscopy and ab initio calculations at various salt concentrations. The SO and CS stretching bands were used to monitor the structural change of the solvation shell. It has been shown that the solvation number of Li+, calculated by the changes in intensities of the CS asymmetric and symmetric stretching bands, is consistent with the value predicted by ab initio calculations. The wavenumber shift of the CH stretching band is suggested to be the result of the anion solvation and the dissociation of the associated DMSO molecules. Copyright © 2007 John Wiley & Sons, Ltd.
Structure Design of Multifunctional Furoate and Pyroglutamate Esters of Dextran by Polymer‐Analogous Reactions
Authors: Hornig Stephanie , Liebert Tim , Heinze Thomas 
Published: March 2007

AbstractWell‐defined multifunctionalized dextran esters bearing photo‐crosslinkable and chiral groups as well as small alkyl moieties for the adjustment of the solubility were prepared from two dextran samples with different origin and molecular weight. The examination of side structures of the starting dextran was carried out by different one‐ and two‐dimensional NMR techniques. The main synthesis path via in situ activation of furan‐2‐carboxylic‐ and pyroglutamic acid with CDI under mild conditions gives highly functionalized dextran derivatives possessing a degree of polymerization in the range of the starting polysaccharide. The subsequent reaction with propionic anhydride leads to completely substituted, CHCl3 soluble derivatives useful for the determination of the particular degree of substitution. By variation of the molar ratios of polymer to reagent with photo‐crosslinkable‐ and chiral moieties during the reaction and even by subsequent peracylation, multifunctional dextran derivatives with adjustable properties like the hydrophilic/hydrophobic balance were obtained that may form biocompatible spherical nanoparticles.magnified image
New Solvents for Cellulose: Dimethyl Sulfoxide/Ammonium Fluorides
Authors: Köhler Sarah , Heinze Thomas 
Published: March 2007

AbstractNew solvents based on DMSO in combination with alkylammonium fluorides, in particular TBAF · 3H2O and BTMAF · H2O, were established as media for homogeneous functionalization of cellulose. Even DMSO in combination with freshly prepared, anhydrous TBAF, obtained by the reaction of tetrabutylammonium cyanide and hexafluorobenzene, dissolves cellulose. In contrast, a mixture of DMSO and tetramethylammonium fluoride does not dissolve cellulose. The solvents were characterized by capillary viscosity, which showed that a cellulose solution of DMSO/BTMAF · H2O possesses a lower viscosity at comparable cellulose concentrations compared with DMSO/TBAF · 3H2O. The determination of the degree of polymerization of the starting cellulose (microcrystalline cellulose, spruce sulfite pulp, and cotton linters), and of the regenerated samples, shows that degradation of the polymer depends on the dissolution time, temperature and on the ammonium fluoride used. The results of different homogeneous reactions including acylation and carbanilation of cellulose in the solvents were compared with those of the most‐commonly‐applied solvent N,N‐dimethylacetamide/LiCl. The products were characterized by elemental analysis, 1H‐ and 13C NMR spectroscopy (additionally after perpropionylation) and FTIR spectroscopy.magnified image
A note on similarity solutions for boundary layer flows with prescribed heat flux
Authors: Tsai Je‐Chiang , Wang Ching‐An 
Published: March 2007

AbstractWe study the third‐order nonlinear equation: f′′′ + (m + 2)ff′′ − (2m + 1)f′2 = 0 on (0, ∞), subject to the boundary conditions f(0) = − γ ∈ ℝ, f′(∞) = 0 and f′′(0) = −1. The problem arises in the study of similarity solutions for boundary layer flows with prescribed heat flux. We will address the following two open questions which were proposed by Brighi and Hoernel (Math. Methods Appl. Sci. 2005; 28: 479–503): The first one is the uniqueness of bounded solutions for $ m \in (-1, -{1\over2}) $ and γ>0, and the second one is the structure of solutions for $ m \in (-1, -{1\over2}) $ and γ⩾0. Copyright © 2007 John Wiley & Sons, Ltd.
Development and calcium level changes in pre‐implantation porcine nuclear transfer embryos activated with 6‐DMAP after fusion
Authors: Im Gi‐Sun , Samuel Melissa , Lai Liangxue , Hao Yanhong , Prather Randall S. 
Published: March 2007

AbstractThis study investigated the effect of treatment with 6‐dimethylaminopurine (6‐DMAP) following fusion on in vitro development of porcine nuclear transfer (NT) embryos. Frozen thawed ear skin cells were transferred into the perivitelline space of enucleated oocytes. Reconstructed oocytes were fused and activated with electric pulse in 0.3 M mannitol supplemented with either 0.1 or 1.0 mM CaCl2. In each calcium concentration, activated oocytes were divided into three groups. Two groups of them were exposed to either ionomycin (I + 6‐DMAP or 6‐DMAP alone. In experiment 2, fused NT embryos in 0.3 M mannitol containing 1.0 mM CaCl2 were exposed to 6‐DMAP either immediately or 20 min after fusion/activation. For 0.1 mM CaCl2, oocytes activated with either I + 6‐DMAP or 6‐DMAP alone showed a higher (P < 0.05) developmental rate to the blastocyst stage than those activated with an electric pulse alone (26.7 and 22.5 vs. 12.5%). For 1.0 mM CaCl2, oocytes activated with either I + 6‐DMAP or 6‐DMAP alone showed significantly higher (P < 0.05) developmental rate to the blastocyst stage (35.6 and 28.3 vs. 19.8%). Developmental rate to the blastocyst stage was (P < 0.05) increased in NT embryos activated with 6‐DMAP 20 min after fusion. 6‐DMAP made a higher and wider Ca2+ transient compared to that induced by electric pulses (Fig. 3). The fluctuation lasted during the time that oocytes were cultured in 6‐DMAP. Regardless of Ca2+ concentration in fusion medium, activation with 6‐DMAP following electric pulses supported more development of porcine NT embryos. Activation of NT embryos with 6‐DMAP after fusion in the presence of 1.0 mM CaCl2 could support better developmental rate to the blastocyst stage. Mol. Reprod. Dev. 74: 1158–1164, 2007. © 2007 Wiley‐Liss, Inc.
Modulation of muscle activity and force fluctuations in the plantarflexors after bedrest depends on knee position
Authors: Yoshitake Yasuhide , Kouzaki Motoki , Fukuoka Hideoki , Fukunaga Tetsuo , Shinohara Minoru 
Published: March 2007

AbstractForce fluctuations in leg muscles increase after bedrest, perhaps due to modulation of the neural strategy that is specific to a muscle or common to agonist muscles. The purpose of this study was to examine the modulation of muscle activity and force fluctuations during steady contractions with variable involvement of plantarflexor muscles after bedrest at knee‐flexed (FLX) and extended (EXT) positions. Before and after 20‐day bedrest, plantarflexion force and surface electromyogram (EMG) in the medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles were measured during steady isometric contractions in five young men. In EXT, power ≤10 HZ in the rectified EMG of MG increased significantly after bedrest. This low‐frequency modulation of muscle activity in MG accompanied a 29% increase in the standard deviation of force. There was no change in EMG in other muscles. In FLX, there was no adjustment in EMG or force fluctuations. These results suggest that low‐frequency modulation of MG plays a role in increasing force fluctuations during steady plantarflexion in EXT after bedrest. The findings indicate task/muscle specificity in the modulation of neural strategy during steady contractions after bedrest and underscore the importance of designing a specific training regimen targeted to particular tasks/muscles with regard to force fluctuations in multiple‐agonist systems. Muscle Nerve, 2007