bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid‐state 14N MAS NMR of ammonium ions as a spy to structural insights for ammonium salts
Authors: Jakobsen Hans J. , Hove Anders R. , Hazell Rita G. , Bildsøe Henrik , Skibsted Jørgen 
Published: February 2006

AbstractThe high resolution offered by magic‐angle spinning (MAS), when compared to the static condition in solid‐state NMR of powders, has been used to full advantage in a 14N MAS NMR study of some ammonium salts: CH3NH3Cl, (NH4)2(COO)2·H2O, (CH3)3(C6H5CH2)NCl, (CH3)3(C6H5)NI, [(n‐C4H9)4N]2Mo2O7, (NH4)2HPO4, and NH4H2PO4. It is shown that the high‐quality 14N MAS NMR spectra, which can be obtained for these salts, allow determination of the 14N quadrupole coupling parameters, i.e. CQ (the quadrupole coupling constant) and ηQ (the asymmetry parameter), with very high precision. In particular, it is shown that precise CQ, ηQ parameters can be determined for at least two different 14N sites in case the individual spinning‐sideband (ssb) intensities arise from a single manifold of ssbs, i.e. the ssbs for the two sites cannot be resolved. This feature of 14N MAS NMR, which is the first demonstration for manifolds of ssb in MAS NMR without the potential information from a central transition, becomes especially useful at the slow spinning frequencies (νr = 1000–1500 Hz) applied to some of the ammonium salts studied here. The detection of the number of sites has been confirmed by the corresponding crystal structures determined from single‐crystal X‐ray diffraction (XRD), either in this work for the unknown structure of benzyl trimethylammonium chloride or from reports in the literature. The magnitudes of the 14N quadrupole coupling constants for the ammonium salts studied here are in the range from CQ ∼ 20 kHz to 1 MHz while the asymmetry parameters span the full range 0 ≤ ηQ ≤ 1. Clearly, the 14N quadrupole coupling parameters (CQ, ηQ) for ammonium ions appear highly sensitive toward crystal structure and therefore appreciably more informative for the characterization of ammonium salts in comparison to the isotropic 14N (or 15N) chemical shifts. Copyright © 2006 John Wiley & Sons, Ltd.
FGF Ligand Family mRNA Expression Profile for Mouse Preimplantation Embryos, Early Gestation Human Placenta, and Mouse Trophoblast Stem Cells
Authors: Zhong W. , Wang Q.T. , Sun T. , Wang F. , Liu J. , Leach R. , Johnson A. , Puscheck E.E. , Rappolee D.A. 
Published: February 2006

AbstractSignaling by fibroblast growth factor (FGF) is essential is for trophoblast stem (TS) cells and preimplantation embryos. FGF4 provides essential signaling, but the expression of the complete set of 23 FGF family members has not been analyzed. Here, semi‐quantitative RT‐PCR and microarray analyses were used to define expression of all FGF ligand mRNA. RT‐PCR was done for developmentally important FGF subfamilies, FGF10/FGF22 and FGF8/FGF17/FGF18 as well as FGF11. FGF4 and FGF18 are detected at highest levels by RT‐PCR and microarrays. FGF10 was detected at low levels in both assays. FGF11 was detected at moderate levels by microarray, but not by RT‐PCR. FGF17 was detected at low levels by array and moderate levels by RT‐PCR. FGF8 and FGF22 were detected by RT‐PCR, but not by microarrays during late cleavage divisions. FGF8, FGF5, and FGF9 were detected in the oocyte by microarray. FGF2, FGF3, and FGF7 were not detected by RT‐PCR or microarrays and FGF13, FGF14, and FGF23 were not detected by microarray. Since a major role of FGF is to maintain TS cells, we tested human and mouse placental cell lines and early gestation human placenta for expression of FGF ligands. Expression in mouse TS cells was compared with preimplantation embryos, and human placental cell line expression was compared with human placenta, to infer which ligands are expressed in placental lineage vs. other cell lineages. The data suggest that human and mouse placenta share FGF18 and its high expression suggests preimplantation and early placental function. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Improved neuronal tract tracing using manganese enhanced magnetic resonance imaging with fast T1 mapping
Authors: Chuang Kai‐Hsiang , Koretsky Alan 
Published: February 2006

AbstractThere has been growing interest in using manganese‐enhanced MRI (MEMRI) to detect neuronal activation, neural architecture, and neuronal connections. Usually Mn2+ produces a very wide range of T1 change. In particular, in neuronal tract tracing experiments the site of Mn2+ injection can have very short T1 while distant regions have small T1 reductions, primarily due to dilution of Mn2+. Most MEMRI studies use T1‐weighted sequences, which can only give optimal contrast for a narrow range of T1 changes. To improve sensitivity to the full extent of Mn2+ concentrations and to optimize detection of low concentrations of Mn2+, a fast T1 mapping sequence based on the Look and Locker technique was implemented. Phantom studies demonstrated less than 6.5% error in T1 compared to more conventional T1 measurements. Using center‐out segmented EPI, whole‐brain 3D T1 maps with 200‐μm isotropic resolution were obtained in 2 h from rat brain. Mn2+ transport from the rat olfactory bulb through appropriate brain structures could be detected to the amygdala in individual animals. The method reliably detected less than 7% reductions in T1. With this quantitative imaging it should be possible to study more extensive pathways using MEMRI and decrease the dose of Mn2+ used. Magn Reson Med, 2006. Published 2006 Wiley‐Liss, Inc.
Passive staining: A novel ex vivo MRI protocol to detect amyloid deposits in mouse models of Alzheimer's disease
Authors: Dhenain Marc , Delatour Benoît , Walczak Christine , Volk Andreas 
Published: February 2006

AbstractAmyloid plaques are one of the hallmarks of Alzheimer's disease (AD). This study evaluated a novel μMRI strategy based on “passive staining” of brain samples by gadoteric acid. The protocol was tested at 4.7T on control animals and APP/PS1 mice modeling AD lesions. T1 was strongly decreased in passively stained brains. On high‐resolution 3D gradient echo images, the contrast between the cortex and subcortical structures was highly improved due to a T2* effect. The brains of APP/PS1 mice revealed plaques as hypointense spots. They appeared larger in long compared to short TE images. This suggests that, after passive staining, plaques caused a susceptibility effect. This easily performed protocol is a complementary method to classic histology to detect the 3D location of plaques. It may also be used for the validation of in vivo MRI protocols for plaque detection by facilitating registration with histology via post mortem MRI. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Bunched phase encoding (BPE): A new fast data acquisition method in MRI
Authors: Moriguchi Hisamoto , Duerk Jeffrey L. 
Published: February 2006

AbstractA new fast data acquisition method, “Bunched Phase Encoding” (BPE), is presented. In conventional rectilinear data acquisition, only a readout gradient (and no phase encoding gradient) is applied when k‐space data are acquired. Reduction of the number of phase encoding lines by increasing the phase encoding step size often leads to aliasing artifacts. Papoulis's generalized sampling theory asserts that in some cases aliasing artifact‐free signals can be reconstructed even if the Nyquist criterion is violated in some regions of the Fourier domain. In this study, Papoulis's theoretical construct is exploited to reduce the number of acquired phase encoding lines. To achieve this, k‐space data are sampled along a “zigzag” trajectory during each readout; samples are acquired at a sampling frequency higher than that of the normal rectilinear acquisition. The total number of TR cycles and, hence, the total scan time can be reduced. The resultant signal‐to‐noise ratio (SNR) often varies across the reconstructed image when using the BPE technique, and the image SNR depends on the reconstruction method. This work is comparable to a gradient based version of parallel imaging. Evidence suggests it may serve as the basis for new opportunities for fast data acquisition in MRI. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Effects of d.c. potential patterns on the performance of ion‐exchange polymer based molecular actuators
Authors: Shoji Eiichi , Hirayama Daisuke , Kusakabe Masahiro , Inoue Tamotsu 
Published: February 2006

AbstractThe dynamic performance (i.e. displacement, current, velocity, and force) of ion‐exchange polymer based actuators (the Nafion™/platinum electrodes) have been examined by developing instrumentation. The CCD imaging technique was examined to evaluate the displacement under the various d.c. potential patterns. Two different d.c. potential patterns with or without a rest were applied to the electrodes at 0.1 Hz. It was better to take a rest at 0 V for the polarization back and forth between +2 and −2 V to give lower current consumption and longer displacement. The actuator produced the force of ca. 0.95 g at 3.25 V in air. The result also demonstrated that higher overpotential has to be avoided to maintain the maximum force. The generative force is in inverse proportion to the length of the actuators. The dimension of the film strongly governs the force production and its performance. Copyright © 2006 John Wiley & Sons, Ltd.
Polarization processes in electrorheological fluids based on conductive polymers
Authors: Krztoń‐Maziopa A. , Ciszewska M. , Płocharski J. 
Published: February 2006

AbstractElectrorheological (ER) fluids are composed of dielectric particles dispersed in an inert liquid of low electric permittivity. Upon the application of an electric field ER fluids rapidly solidify, or increase their viscosity. Characteristic increase of the viscosity of ER fluids is due to the formation of particle chains that bridge the electrodes. This process is greatly affected by polarization processes within the solid phase and at the surface of the grains. These phenomena are governed by dopants, functional groups, structure of the solid particles and the solid/liquid interface. To find relations between parameters of the ER effect and material properties of components of ER fluids, two main types of the materials were investigated: conjugated polymers [polyphenylene (PPP), pyrolyzed polyacrylonitrile (PAN) and polythiophene] and solid electrolytes based on polyacrylonitrile complexed with inorganic salts. It was found that the ER activity resulted from surface polarization processes due to the presence of polar species (PAN) or bulk polarization related to mobile ions (PPP). Polythiophene, despite the presence of a conjugated system of multiple bonds, showed only residual ER effect. Solid electrolyte‐based fluids exhibited relatively high activity originated from ionic polarization. Copyright © 2006 John Wiley & Sons, Ltd.
Mechanism of Romascone® release from hydrolyzed vinyl acetate nanoparticles: thermogravimetric method
Authors: Ouali L. , Léon G. , Normand V. , Johnsen H. , Dyrli A. , Schmid R. , Benczedi D. 
Published: February 2006

AbstractThe evaporation kinetics of pure Romascone® (methyl 2,2‐dimethyl‐6‐methylene‐1‐cyclohexanecarboxylate) and Romascone® when mixed with vinyl acetate (VAc) nanoparticles have been determined by using thermogravimetric analysis. For pure Romascone®, the evaporation rate follows an Arrhenius dependence with temperature. When Romascone® is mixed with VAc nanoparticles, two evaporation mechanisms are identified depending on the presence of comonomer and crosslinking degree. (a) Evaporation limited by the presence of non‐interactive nanoparticles. The evaporation rate is governed by the evolution of the equilibrium vapor pressure that depends on the volume fraction of volatile molecules. (b) Evaporation limited by the diffusion of volatile molecules through a polymeric particle wall.Since the diffusion depends on the physical state or structure of the polymeric nanoparticle phase, the volume fraction of volatile molecules is a determinant parameter. Furthermore, a sudden modification in the evolution of the diffusion coefficient with volatile volume fraction gives rise to discussion on phase transition. Copyright © 2006 John Wiley & Sons, Ltd.
Electrorheological effect in hybrid fluids with liquid crystalline additives
Authors: Ciszewska M. , Krztoń‐Maziopa A. , Płocharski J. 
Published: February 2006

AbstractConventional electrorheological (ER) fluids consist of electrically polarizable particles dispersed in an inert insulating liquid. They are characterized by a development of a yield stress upon application of an external electric field. They resemble Bingham fluids with yield stress value depending on electric field. A viscosity increase in the presence of an electric field has been also found in homogeneous solutions of liquid crystalline polymers with no yield stress observed. In this study these two types of fluids and combined dispersions of the solid particles in the liquid crystalline matrix were investigated. A lyotropic liquid crystalline polymer—poly(n‐hexyl isocyanate) (PHIC)—dissolved in xylene was chosen as the active matrix. The dispersed solid phase was comprised of two kinds of polymers: pyrolyzed polyacrylonitryle (PAN) showing electron conductivity, and PAN doped with two salts (KSCN, NaSCN), resulting in ionic conductivity. The rheological measurements under an electric field were performed. The pristine xylene solution of PHIC was characterized first as well as the 15% m/m dispersions of PAN powders in silicone oil. Then the dispersions in the liquid crystalline matrix were investigated showing a strong ER effect whose magnitude was considerably enhanced in comparison to both ER active components measured separately. Copyright © 2006 John Wiley & Sons, Ltd.
Regulated release of VWF and FVIII and the biologic implications
Authors: Haberichter S.L. , Shi Q. , Montgomery R.R. 
Published: February 2006

Abstractvon Willebrand factor (VWF) performs a critical function in platelet binding at the site of vascular injury and also serves as the carrier protein for coagulation factor FVIII (FVIII), protecting it from proteolytic degradation in plasma. Both proteins undergo rapid, regulated release in response to DDAVP administration in patients with mild hemophilia A or von Wille‐brand disease. Here, we attempt to summarize our current understanding of the establishment of the regulated storage pool of VWF and FVIII. The data presented indicate that regulated secretion of both proteins occurs only if there is endogenous synthesis of FVIII together with VWF. © 2006 Wiley‐Liss, Inc.
Central nervous system‐related permanent consequences in patients with Langerhans cell histiocytosis
Authors: Mittheisz Edda , Seidl Rainer , Prayer Daniela , Waldenmair Marion , Neophytou Birgit , Pötschger Ulrike , Minkov Milen , Steiner Manuel , Prosch Helmut , Wnorowski Martha , Gadner Helmut , Grois Nicole 
Published: February 2006

AbstractBackgroundPermanent consequences in Langerhans cell histiocytosis (LCH) are irreversible late sequelae related to the disease that may severely impair the quality of life of survivors. The frequency and pattern of permanent consequences affecting the central nervous system (CNS) remains to be determined.ProcedureIn this single center study, 25 LCH patients observed for a median time of 10 years 3 months underwent a uniform thorough follow‐up program including neuropsychological testing and electrophysiological evaluation.ResultsOverall permanent consequences were seen in 9 of 25 patients. Intracranial abnormalities were the most frequent including diabetes insipidus (DI) in seven patients, anterior pituitary deficiencies in five patients, and neurodegenerative CNS disease in five patients. No patient had overt neurological symptoms upon neurological evaluation, but psychological testing revealed subtle deficits in short‐term auditory memory (STAM) in 14 patients. Brain stem evoked potentials showed abnormalities in four of nine tested patients, all of these four had neurodegeneration on MRI.ConclusionPsychoneuroendocrine sequelae were found in an unexpectedly high number of patients in this single center study. Long‐term follow‐up focusing on such sequelae are important in LCH survivors, in order to detect early deficits, to monitor the evolution of the disease, and to provide specific support. Pediatr Blood Cancer 2007;48:50–56. © 2006 Wiley‐Liss, Inc.
Adolescents with acute lymphoblastic leukaemia: Emerging from the shadow of paediatric and adult treatment protocols
Authors: Ramanujachar Ramya , Richards Sue , Hann Ian , Webb David 
Published: February 2006

AbstractAdolescents and young adults (AYA) with acute lymphoblastic leukaemia (ALL) constitute a distinct population from children and older adults. Based on patterns of referral, they may be treated by either paediatric or adult oncologists. As a group, AYA with ALL have a worse survival and event‐free survival (EFS) compared to that achieved by younger children. A systematic review of all published clinical trials, which provide data on treatment and outcome of adolescents with ALL, has been summarised in an effort to determine whether they should be treated on paediatric or adult type protocols. Adolescents appear to have a consistent survival advantage when treated on paediatric regimens. Pediatric Blood Cancer 2006;47:748–756. © 2006 Wiley‐Liss, Inc.
Secondary pseudotumor cerebri in pediatric oncology and hematology: An unpredictable condition of varying etiology
Authors: Distelmaier Felix , Göbel Ulrich , Vandemeulebroecke Nicola , Mayatepek Ertan , Rosenbaum Thorsten , Laws Hans‐Jürgen 
Published: February 2006

AbstractSecondary pseudotumor cerebri (PTC) in pediatric oncology and hematology is an unpredictable and under‐recognized condition. It is characterized by increased cerebrospinal fluid (CSF) pressure of more than 25 cm H2O in the absence of underlying structural causes. Numerous conditions and medications have been implicated in the etiology of secondary PTC. Patients may suffer from incapacitating headaches and permanent visual loss, if they are not managed properly. We retrospectively analyzed the records of eight children, diagnosed with secondary PTC with an underlying hematological or oncological disease. Our study highlights the clinical features, contributing factors, and treatment options of this syndrome in children. Pediatr Blood Cancer 2007;49:1029–1033. © 2006 Wiley‐Liss, Inc.
Prenatal counselling of small bowel atresia:watch the fluid!
Authors: Iacobelli Barbara D. , Zaccara Antonio , Spirydakis Ioannis , Giorlandino Claudio , Capolupo Irma , Nahom Antonella , Bagolan Pietro 
Published: February 2006

AbstractObjectiveTo evaluate polyhydramnios as a sign of extreme disproportion of atretic segments in small bowel atresia (SBA).MethodsTwenty‐eight patients with a prenatal diagnosis (PD) of SBA undergoing neonatal surgical treatment were reviewed retrospectively. Parameters recorded were gestational age, birth weight, surgical procedure, rate of complications, parenteral nutrition (PN) days and length of stay (LOS). Patients were divided into two groups: Group A with delayed anastomosis and Group B with direct anastomosis.ResultsSeventeen subjects were in Group A while 11 were in Group B. The two groups did not differ with regard to gestational age at diagnosis, birth weight and obstetrical management. Polyhydramnios was present in both Group A (64.7%) and Group B (9%) (p < 0.05). Patients in Group A needed a longer period on PN, had a longer LOS and exhibited significantly higher rates of complication.ConclusionIn the absence of other malformations, association of dilated bowel loops and polyhydramnios is highly predictive of severe SBA, which can in no instance be amenable to one‐stage reconstruction. Because of its consequences on postnatal treatment, such information should be conveyed to the prospective parents at the time of counselling. Copyright © 2006 John Wiley & Sons, Ltd.
Laboratory monitoring of potassium and creatinine in ambulatory patients receiving angiotensin converting enzyme inhibitors and angiotensin receptor blockers
Authors: Raebel Marsha A. , McClure David L. , Simon Steven R. , Chan K. Arnold , Feldstein Adrianne , Andrade Susan E. , Lafata Jennifer Elston , Roblin Douglas , Davis Robert L. , Gunter Margaret J. , Platt Richard 
Published: February 2006

AbstractPurposeSerum potassium and creatinine monitoring is recommended for patients prescribed angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB). Much has been written about hyperkalemia associated with these drugs; little is known about laboratory monitoring patterns. The purpose of this retrospective cohort study was to assess creatinine and potassium monitoring and characteristics associated with monitoring among patients dispensed ACEi or ARB.MethodsThis study was conducted in 10 United States health maintenance organizations. Study patients (n = 52 906) were aged 18 or older with dispensings of ACEi or ARB for at least 1 year. Serum potassium and creatinine monitoring were assessed from administrative data and medical records.ResultsMore than two‐thirds (68.4%) of patients received laboratory monitoring. Likelihood of monitoring increased with age (adjusted odds ratio [OR] 2.10; 95% confidence interval [95%CI] 1.93, 2.28 [individuals ≥ 80 compared to <50 years]), >9 outpatient visits (OR 1.46; 95%CI 1.39, 1.54), hospitalization (OR 1.15; 95%CI 1.06, 1.25), concomitant medications (potassium [OR 2.01; 95%CI 1.84, 2.20], diuretics [OR 1.54; 95%CI 1.47, 1.61], digoxin [OR 1.15; 95%CI 1.01, 1.30]), and comorbidities (diabetes [OR 1.68; 95%CI 1.61, 1.75], heart failure [OR 1.73; 95%CI 1.57, 1.90], chronic kidney disease [OR 2.95; 95%CI 2.48. 3.51]).ConclusionsNearly one‐third of patients dispensed ACEi or ARB did not undergo laboratory monitoring at least yearly. Though patients at increased risk of hyperkalemia were more likely to be monitored, many remained unmonitored. Copyright © 2006 John Wiley & Sons, Ltd.
Comparative proteome approach to characterize the high‐pressure stress response of Lactobacillus sanfranciscensis DSM 20451T
Authors: Hörmann Sebastian , Scheyhing Carsten , Behr Jürgen , Pavlovic Melanie , Ehrmann Matthias , Vogel Rudi F. 
Published: February 2006

AbstractHigh hydrostatic pressure (HHP) exerts diverse effects on microorganisms, leading to stress response and cell death. While inactivation of microorganisms by lethal HHP is well investigated in the context of food preservation and the hygienic safety of minimal food processes, sublethal HHP stress response and its effect on adaptation and cross‐protection is less understood. In this study, the HHP stress response of Lactobacillus sanfranciscensis was characterized and compared with cold, heat, salt, acid and starvation stress at the proteome level by using 2‐DE so as to provide insight into general versus specific stress responses. Sixteen proteins were found to be affected by HHP and were identified by using N‐terminal amino acid sequencing and MS. Only one slightly increased protein was specific to the HHP response and showed homology to a clp protease. The other proteins were influenced by most of the investigated stresses in a similar way as HHP. The highest similarity in the HHP proteome was found to be with cold‐ and NaCl‐stressed cells, with 11 overlapping proteins. At the proteome level, L. sanfranciscensis appears to use overlapping subsets of stress‐inducible proteins rather than stereotype responses. Our data suggest that a specific pressure response does not exist in this bacteria.