bluuebunny/crossref_metadata_2025 huggingface dataset:
Breath‐holding in healthy and pulmonary‐compromised populations: Effects of hyperventilation and oxygen inspiration
Authors: Marks Burton , Mitchell Donald G. , Simelaro John P.
Published: March 2007

Suspension of respiration during end‐expiration often is recommended to minimize body organ displacement between sequential image acquisitions. The purpose of this report is to evaluate techniques for end‐expiratory breath‐holding applicable to a pulmonary‐compromised population. Eighty‐seven consecutive outpatients with chronic pulmonary diseases and 31 healthy nonsmoking volunteers were recruited for the study. All subjects were asked to hold their breath in end‐expiration while in the supine position (29 after breathing room air, 29 after hyperventilating room air for six breaths, and 29 after breathing O2 from a portable oxygen tank via nasal cannula until pulse‐oximeter readings stabilized or reached 100%). Each volunteer was tested with all three methods. The mean length of time for a breath‐hold on room air without hyperventilation was 9.2 seconds for the patients and 31.7 seconds for the volunteers. A breath‐hold after hyperventilation of room air was timed at 12.3 seconds for the patients and 41.2 seconds for the volunteers, and after O2 administration, the breath‐hold was 22.4 seconds for the patients and 60.9 seconds for the volunteers. No adverse effects occurred. The pulmonary‐compromised patient can suspend respiration most successfully after O2 administration (P < .0001), whereas hyperventilation seems to be less beneficial. Nonpulmonary‐compromised volunteers can hold their breath for longer periods of time.
MRI acoustic noise: Sound pressure and frequency analysis
Authors: Counter S. Allen , Olofsson Ake , Grahn H. F. , Borg Erik
Published: March 2007

The large gradient colls used in MRI generate, simultaneously with the pulsed radiofrequency (RF) wave, acoustic noise of high intensity that has raised concern regarding hearing safety. The sound pressure levels (SPLs) and power spectra of MRI acoustic noise were measured at the position of the human head in the isocenter of five MRI systems and with 10 different pulse sequences used in clinical MR scanning. Each protocol, including magnetization‐prepared rapid gradient echo (MP‐RAGE; 113 dB SPL linear), fast gradient echo turbo (114 dB SPL linear), and spin echo Tl/2 mm (117 dB SPL linear), was found to have the high SPLs, rapid pulse rates, amplitude‐modulated pulse envelopes, and multi‐peaked spectra. Slice thickness and SPL were inversely related, and Tl‐weighted images generated more intense acoustic noise than the proton‐dense T2‐weighted measures. The unflltered linear peak values provided more accurate measurements of the SPL and spectral content of the MRI acoustic noise than the commonly used dB A‐weighted scale, which filters out the predominant low frequency components. Fourier analysis revealed predominantly low frequency energy peaks ranging from .05 to approximately.
Contrast‐enhanced, k‐space‐centered, breath‐hold MR angiography of the renal arteries and the abdominal aorta
Authors: Steffens Johann‐C. , Link Johann , Grässner Joachim , Mueller‐Huelsbeck Stefan , Brinkmann Gisbert , Reuter Michael , Heller Martin
Published: March 2007

The purpose of this study was to evaluate the capability of contrast‐enhanced breath‐hold fast imaging with steady‐state precession (FISP) three‐dimensional MR angiography (MRA) to detect stenotic lesions of the abdominal aorta, the renal arteries, and the iliac arteries by using a k‐space‐centered 20‐ml gadolinium‐diethylene pentaacetic acid (Gd‐DTPA) bolus. Fifty patients were studied before conventional x‐ray angiography. Contrast‐enhanced breath‐hold FISP three‐dimensional MRA was applied in the coronal view, centered at the renal arteries. Twenty ml of Gd‐DTPA was used in all subjects. A test bolus was applied to determine the injection time for the k‐space‐centered bolus injection. Of 300 segments, 284 segments were classified correctly, 11 were overestimated, and five were underestimated. Sensitivity was 98%, specificity was 96%, positive predictive value was 96%, negative predictive value was 98%, and accuracy was 97%. Of the 50 patients studied, 43 were staged correctly. No venous overlay was seen in 31 patients; partial overlay was seen in 16 patients, and venous structure overlay obscuring arterial anatomy was found in two patients. Six of nine accessory renal arteries could be identified by MRA. Intraobserver variability was .94. This study has shown the ability of contrast‐enhanced breath‐hold FISP three‐dimensional MRA to detect and grade vascular lesions in the abdominal aorta and the renal arteries. The method may serve as a screening tool in the future.
MR navigator‐echo monitoring of temporal changes in diaphragm position: Implications for MR coronary angiography
Authors: Taylor Andrew M. , Jhooti Permi , Wiesmann Frank , Keegan Jennifer , Firmin David N. , Pennell Dudley J.
Published: March 2007

Temporal changes in respiration could influence navigator‐echo (NE)‐gated MR coronary angiography (MRCA), but systematic investigation of the effects of such variations and how to limit them has not been performed. We addressed these issues by studying the influence of time in the magnet on diaphragm position and respiratory patterns using NE diaphragm monitoring in volunteers and a phantom model. NE diaphragm monitoring was performed at .5 T in 10 subjects over a total period of 35 minutes. The end‐expiratory position was sustained for longer (1.1 vs .4 seconds, P < .001) and with greater position stability (SD 1.9 vs 5.9 mm, P = .01) than the end‐inspiratory position. Drift of the end‐expiratory position occurred over time, causing a fall in scan efficiency (44–28%, P = .01). Up‐drift of the end‐expiratory position was most common. Loss of scan efficiency was worse with up‐drift because of loss of the end‐expiratory pause from the NE window (up‐drift 10% mm−1, down‐drift 7% mm−1, both P = .03). Scan efficiency also was reduced during sleep (to a nadir of 0%), secondary to loss of the end‐expiratory pause, periodic breathing with oscillating end‐expiratory position, and periods of apnea. The phantom model used actual diaphragm traces to evaluate the artifact resulting from diaphragm motion during acquisition. Artifact was considerably reduced by NE adaptive motion correction compared with NE gating alone (ghosting ratio 2.0 vs 2.8, P < .01). Artifact also was significantly reduced with up‐drift if scan efficiency was maintained above 35% (P = .05). For optimal NE‐gated MRCA, the following features are important: the NE window should be placed around the end‐expiratory position; subjects should not sleep; scan efficiency should be monitored and the NE window should be repositioned if scan efficiency falls below 35%; and adaptive motion correction should be used.
Flow‐independent angiography for peripheral vascular disease: Initial in‐vivo results
Authors: Gronas Rolf , Kalman Peter G. , Kucey Daryl S. , Wright Graham A.
Published: March 2007

Flow‐independent angiography (FIA), an approach that isolates arterial blood using MR relaxation characteristics rather than flow effects, was evaluated for application in peripheral vascular disease (PVD). First, pilot studies were conducted in which FIA coronal projection images were obtained from controls and symptomatic patients with PVD to assess clinical utility. All control images corresponded to the expected leg arterial anatomy with little interference from deep veins (one of five) and muscle (zero of five). Superficial venous signal was less well suppressed in comparison to deep veins (four of five). Images of symptomatic patients were less consistent with difficulty suppressing muscle and deep venous signal in some cases and edema when present. We then compared T2 values for muscle (T2m, tibialis anterior), arterial blood (femoral and popliteal arteries), and venous blood (femoral, popliteal, and saphenous veins) in controls (n = 8) and symptomatic patients with intermittent claudication (n = 5) or ischemic rest pain (n = 7). Changes in T2 measurements of various tissues accounted for poorer contrast in symptomatic patients. Patients with ischemic rest pain had significantly higher T2m compared with controls (T2m = 39.3 ± 2.1 (1 standard error of the mean [SEM]) versus 30.9 ± .4, P < .01). For all measurements, other than saphenous vein, variances were greater in symptomatic patients. To realize the inherent advantages of FIA for this clinical application, additional work on suppression of signals from muscle, veins, and edema is required. One promising approach involves shifting from projection images to three‐dimensional acquisitions for improved tissue suppression.
Proximal coronary artery stenosis: Three‐dimensional MRI with fat saturation and navigator echo
Authors: Müller Markus F. , Fleisch Martin , Kroeker Randall , Chatterjee Tushar , Meier Bernhard , Vock Peter
Published: March 2007

The purpose of this study was to compare the diagnostic value of MR angiography (MRA) with conventional contrast angiography in coronary artery disease. Thirty‐five patients underwent MRA and coronary angiography within 4 hours. Of these, three patients were investigated twice: once before and once after balloon angioplasty. The pulse sequence was a cardiac‐triggered, single‐slab, three‐dimensional gradient‐echo sequence, employing a spin‐echo navigator echo measurement to track the variation of the diaphragm during the scan. The following segments of the coronary arteries were included in this prospective study: left main coronary artery, proximal and middle left anterior descending, proximal and middle left circumflex, proximal and middle right coronary artery, and intermediate branch, if present. In total, 176 segments were classified as normal or having a stenosis of less than 50% and as having a stenosis of more than 50%. Five patients were excluded because of lack of cooperation. Over all, 45 of 54 stenoses were detected and interpretable by MRA. Sensitivity, specificity, and positive and negative predictive values of MRA for detecting significant stenoses were 83%, 94%, 87%, and 93%, respectively. MRA identified significant stenoses within the major coronary arteries with a high degree of accuracy. Sensitivity and specificity are higher compared with exercise tests or scintigraphy or top of the precise localization.
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

Noninvasive 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

We 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

The 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

We 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

To 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

A 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

Integrating 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

The 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

Even 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

The 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

The 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

Solvation 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.
Spectral transformation of megawatt femtosecond optical pulses in large-mode-area high-index-step photonic-crystal fibers
Authors: Mitrokhin V P , Ivanov A A , Fedotov A B , Alfimov M V , Dukel'skii K V , Khokhlov A V , Shevandin V S , Kondrat'ev Yu N , Podshivalov A A , Zheltikov A M
Published: March 2007

An assortment of photonic-crystal fibers with a core area varying from 20 to 50 μm2 is used to demonstrate efficient frequency conversion of megawatt femtosecond Cr:forsterite laser pulses with a central wavelength of 1.24 μm into the visible and infrared spectral ranges. Supercontinuum radiation with a spectrum spanning from 500 to 1800 nm and total output energy of hundreds of nanojoules is observed at the fiber output.
Stable acousto-optics Q-switched Nd:YVO4 laser at 500 kHz
Authors: He F , Huang L , Gong M , Liu Q , Yan X
Published: March 2007

Up to 1 MHz acousto-optics Q-switching operation was obtained in a grazing-incidence Nd:YVO4 laser. At 500 kHz repetition rate, 17.7 W of output power was obtained with 38 W of pump power when 32.4% transmissivity output coupler was used. The beam quality factors were measured as M
2
x < 4 in the x-axis direction and M
2
y < 2 in the y-axis direction. For high sable acousto-optics pulse operation, 5% transmissivity output coupler was used and 9.15 W of output power was obtained at 38 W of pump power. The peak-to-peak instability of pulse amplitude was less than ±3.3% at 489.6 kHz repetition rate.
Structure Design of Multifunctional Furoate and Pyroglutamate Esters of Dextran by Polymer‐Analogous Reactions
Authors: Hornig Stephanie , Liebert Tim , Heinze Thomas
Published: March 2007

Well‐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.

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New Solvents for Cellulose: Dimethyl Sulfoxide/Ammonium Fluorides
Authors: Köhler Sarah , Heinze Thomas
Published: March 2007

New 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.

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A note on similarity solutions for boundary layer flows with prescribed heat flux
Authors: Tsai Je‐Chiang , Wang Ching‐An
Published: March 2007

We 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

This 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

Force 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
Genetics of inclusion‐body myositis
Authors: Needham M. , Mastaglia F.L. , Garlepp M.J.
Published: March 2007

Sporadic inclusion‐body myositis (sIBM) is the most common acquired muscle disease in Caucasians over the age of 50 years. Pathologically it is marked by inflammatory, degenerative, and mitochondrial changes that interact in a yet‐unknown way to cause progressive muscle degeneration and weakness. The cause of the disease is unknown, but it is thought to involve a complex interplay between environmental factors, genetic susceptibility, and aging. The strongest evidence for genetic susceptibility comes from studies of the major histocompatibility complex (MHC), where different combinations of alleles have been associated with sIBM in different ethnic groups. The rare occurrence of familial cases of inclusion‐body myositis (fIBM) adds additional evidence for genetic susceptibility. Other candidate genes such as those encoding some of the proteins accumulating in muscle fibers have been investigated, with negative results. The increased understanding of related disorders, the hereditary inclusion‐body myopathies (hIBM), may also provide clues to the underlying pathogenesis of sIBM, but to date there is no indication that the genes responsible for these conditions are involved in sIBM. This review summarizes current understanding of the contribution of genetic susceptibility factors to the development of sIBM. Muscle Nerve, 2007
Pitfalls in the electrodiagnostic studies of sacral plexopathies
Authors: Tavee Jinny , Mays Maryann , Wilbourn Asa J.
Published: March 2007

This retrospective review characterizes the electrodiagnostic (EDX) features and etiologies of sacral plexopathies (SPs) and discusses difficulties in their identification. The EDX findings of 171 clinically suspected SPs were reviewed using the following criteria: reduced/absent sensory nerve action potentials (SNAPs) of the sural or superficial peroneal nerve, denervation of plexus‐innervated muscles, and the absence of paraspinal denervation. Sixty cases localized unequivocally to the sacral plexus. The majority were cancer‐related, followed by traumatic, idiopathic, and iatrogenic causes. Final diagnoses in the remaining 111 cases were indeterminate. Lesions localized to either the plexus or L4–5, S1 roots in 52 cases, the plexus or sciatic nerve in 32 cases, and were equally compatible with an SP, sciatic neuropathy, or radiculopathy in 27 cases. Findings in the EDX evaluation of SPs are often complex and difficult to localize to a specific site due to multiple complicating factors. Frequently, SPs cannot be diagnosed definitively by EDX assessment alone. Muscle Nerve, 2007
Client experiences in work rehabilitation in Sweden: a one‐year follow‐up study
Authors: Wallstedt‐Paulsson Eva , Erlandsson Lena‐Karin , Eklund Mona
Published: March 2007

This study, carried out in a work rehabilitation unit in Sweden, investigated how clients perceived their work experiences after a one‐year follow up. A semi‐structured interview was administered to 14 former clients and a content analysis was applied. Seven categories were derived from the results: ‘Expectations of the rehabilitation process’; ‘Social relationships’; ‘Client influences on the rehabilitation process’; ‘Occupations engaged in during the rehabilitation programme’; ‘Perceived outcome’; ‘Current occupations’; and ‘Future aspirations’. The dominating expectations were to find a job, with an overall desire for change. The social relationships with the staff and other clients were of great importance. The positive outcome of the rehabilitation was described as feeling better or having new skills. The perceived negative outcome was that the rehabilitation programme had not turned out as the client expected. The clients reported varying daily occupations after the rehabilitation experience and a majority were contented and optimistic about their future. The main conclusions of the study are that when planning a work rehabilitation programme, efforts have to be made to examine clients' interests and skills, and to develop a dialogue between clients and staff. Further research is needed to evaluate the work rehabilitation experience from the clients' perspective. Copyright © 2007 John Wiley & Sons. Ltd.
Treatment of pediatric non‐Hodgkin lymphoma in Hungary: 15 years experience with NHL‐BFM 90 and 95 protocols
Authors: Müller Judit , Csóka Monika , Jakab Zsuzsanna , Ponyi Andrea , Erlaky Hajna , Kovács Gábor
Published: March 2007

Retrospective analysis was performed to assess the survival‐rates of children with non‐Hodgkin lymphoma (NHL), treated according to the NHL‐BFM (Berlin‐Frankfurt‐Münster)‐90 and ‐95 protocols between 1990 and 2004 in Hungary, and to compare our data with the international results. Ninety‐one patients had non‐B‐NHL, 108 B‐NHL, and 31 ALCL. Complete remission rate was 89%, while 12% relapsed later. The 5‐year‐overall‐survival was 78% and the event‐free survival was 75%. These results are lower than those reported by the BFM study group, but comparable from other European centers. In the last 5 years, the results showed 10% improvement and death during induction was reduced from 10 to 3%. Pediatr Blood Cancer 2008;50:633–635. © 2007 Wiley‐Liss, Inc.
Early‐onset sarcoidosis mimicking refractory cutaneous histiocytosis
Authors: Ohga Shouichi , Ichino Kiyomi , Urabe Kazunori , Ishimura Masataka , Takada Hidetoshi , Nishikomori Ryuta , Furue Masutaka , Hara Toshiro
Published: March 2007

A 10‐year‐old female was diagnosed as having early‐onset sarcoidosis (EOS) after a prolonged skin disease. A granuloma emerged on the face at age 2 and massive lesions extended to the rest of the body. Repeated biopsies indicated histiocytic proliferation. At age 7, fever, disseminated macular eruptions, and multinucleated giant cells in the bone marrow prompted vinblastine and prednisolone therapy. Five months after stopping therapy, hypercalcemic crisis occurred along with fever, cytopenias, and interferon‐γ‐nemia indicating a macrophage activation syndrome. A biopsy of nodules confirmed the diagnosis of sarcoidosis. The atypical EOS should be differentiated from histiocytosis. Pediatr Blood Cancer 2008;50:723–726. © 2007 Wiley‐Liss, Inc.
Immune response to conjugated meningococcal C vaccine in pediatric oncology patients
Authors: Yu Joyce W. , Borkowski Astrid , Danzig Lisa , Reiter Stephanie , Kavan Peter , Mazer Bruce D.
Published: March 2007

Background

Following outbreaks of meningococcal disease in Quebec in 1991–1993 and 2000–2001, a mass vaccination campaign was performed. In 2001–2002, children aged 2 months to 20 years were immunized with the Meningococcal CRM197 vaccine (Menjugate™). We examined the response of pediatric oncology patients during or following maintenance chemotherapy and post‐bone‐marrow transplantation to Meningococcal C vaccine.

Procedure

This was an open label descriptive study of a cohort of patients from the oncology clinic at the Montreal Children's Hospital. A positive vaccine response was defined as a fourfold increase in specific IgG from baseline and a bactericidal assay using human complement (hBCA) titer >1:4.

Results

Of the 25 patients with ALL, 13 had a serologic response (average 60‐fold increase). The serologic responders had a higher mean B cell count (0.262) compared to non‐responders 0.068 × 10.9/L [t(23) = 2.843 (P < 0.05)]. Eleven of the 12 non‐responders and 4 of the responders were on maintenance chemotherapy. In addition, two of the five patients post‐bone‐marrow transplant, responded. Fifteen of the 34 patients (44%) had an adequate hBCA response (mean titer 61). The group included 14/18 serologic responders with hBCA response (P < 0.001) and 16/17 non‐serologic responders with no hBCA response (P < 0.001).

Conclusions

Meningococcal C‐conjugate vaccine produced variable responses in children with common cancers. Proximity to chemotherapy and total B cell number may help predict likelihood of response. Pediatr Blood Cancer 2007;49:918–923. © 2007 Wiley‐Liss, Inc.
Complementary and alternative therapy use in adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study
Authors: Mertens Ann C. , Sencer Susan , Myers Cynthia D. , Recklitis Christopher , Kadan‐Lottick Nina , Whitton John , Marina Neyssa , Robison Leslie L. , Zeltzer Lonnie
Published: March 2007

Background

Little information is available on the use of complementary and alternative medicine (CAM) in long‐term survivors of childhood and adolescent cancer.

Procedure

The Childhood Cancer Survivor Study (CCSS) is a resource evaluating the long‐term effects of cancer and associated therapies in 5‐year survivors of childhood and adolescent cancer diagnosed between 1970 and 1986 before the age of 21 years. A survey of CAM use during the previous year was distributed in 2000–2001 and completed by 9,984 survivors and 2,474 sibling controls.

Results

CAM use reporting was similar in cases (39.4%) and siblings (41.1%). Compared to female siblings, female survivors were more likely to use biofeedback (odds ratio (OR) = 3.3; 95% CI = 1.0–10.8) and hypnosis/guided imagery (OR = 3.2; 95% CI = 1.6–6.8); male survivors were more likely than male siblings to use herbal remedies (OR = 1.3; 95% CI = 1.1–1.6). Factors associated with CAM use in survivors included elevated scores on the brief symptom inventory (BSI)‐18 (OR = 1.6; 95% CI = 1.3–1.9), prolonged pain (OR  = 1.5; 95% CI = 1.3–1.7), and having seen a physician in the past 2 years (OR = 1.6; 95% CI = 1.4–1.8). Survivors reporting low alcohol intake and excellent or good general health reported lower levels of CAM use (OR = 0.7; 95% CI = 0.7–0.8 and OR = 0.8; 95% CI = 0.7–0.9, respectively).

Conclusions

Survivors have a similar reported use of CAM compared to a sibling cohort. However, our data suggest that survivors turn to CAM for specific symptoms related to previous diagnosis and treatment. Future research is needed to determine whether CAM use reflects unmet health needs in this population. Pediatr Blood Cancer 2008;50:90–97. © 2007 Wiley‐Liss, Inc.
Evidence of population mixing based on the geographical distribution of childhood leukemia in Ohio
Authors: Clark Brenda R. , Ferketich Amy K. , Fisher James L. , Ruymann Frederick B. , Harris Randall E. , Wilkins John R.
Published: March 2007

Background

This ecologic study examined the geographic distribution of childhood leukemias in Ohio, 1996–2000, among children aged 0–19 for evidence that population mixing may be a factor.

Procedure

(1) State incidence rates were compared to Surveillance, Epidemiology and End Results (SEER) rates for each year and for the 5‐year period, 1996–2000; (2) incidence rates for each of Ohio's 88 counties were compared to statewide rates; and (3) county incidence rates were compared based on population density, population growth, and rural/urban locale. SEER*Stat version 5.0 was used to derive age‐specific and 0–19 age‐adjusted rates. Expected values, standardized incidence ratios (SIRs), and Poisson P‐values were calculated with Excel using the indirect method of standardization.

Results

Of the 585 cases, 73.3% were acute lymphocytic leukemia (ALL), 16.6% acute myelogenous leukemia (AML), 3.2% acute monocytic leukemia (AMoL), and 2.6% chronic myelogenous leukemia (CML). Rates for total leukemia burden were significantly below national levels for all races (P = 0.00001), likely due to poor ascertainment of cases. Yearly incidence rates for 1996–2000 were stable for ALL and AML; CML rates declined over the period. Based on 2000 Census and intercensal population estimates for 1996–2000, statistically higher rates for ALL were noted for counties experiencing >10% population change 1990–2000 (P < 0.05), especially for ages 1–4 (P < 0.03) in counties with 10–20% growth. Counties 67.9–99.2% urban experienced fewer than expected cases of AML + AMoL (P < 0.06).

Conclusion

Data support Kinlen's theory of population mixing and warrant further studies in Ohio, the US and other countries. Pediatr Blood Cancer 2007;49:797–802. © 2007 Wiley‐Liss, Inc.
The balance between durability, reliability, and affordability in structural composites manufacturing
Authors: Cabrera‐Ríos Mauricio , Castro José M.
Published: March 2007

Fiber reinforced structural composites will play a key role in the development of the next generation of transportation vehicles (passenger cars, vans, light trucks, and heavy trucks) because of their high strength‐to‐weight and stiffness‐to‐weight ratio compared with metals. An integrated assessment of the durability, reliability, and affordability of these materials is critical to facilitate the inclusion of these materials into new designs. The result of this assessment should provide information to find the balance between the three performance measures. This paper describes a method to develop this assessment in the fabrication of sheet molding compound (SMC) parts, and discusses the concept of Preform Insert Assembly (PIA) for improved affordability in the manufacturing of composite parts. POLYM. COMPOS., 28:233–240, 2007. © 2007 Society of Plastics Engineers