bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorine‐19 MRI for visualization and quantification of cell migration in a diabetes model
Authors: Srinivas Mangala , Morel Penelope A. , Ernst Lauren A. , Laidlaw David H. , Ahrens Eric T. 
Published: September 2007

AbstractThis article describes an in vivo imaging method for visualizing and quantifying a specific cell population. Cells are labeled ex vivo with a perfluoropolyether nanoparticle tracer agent and then detected in vivo using 19F MRI following cell transfer. 19F MRI selectively visualizes only the labeled cells with no background, and a conventional 1H image taken in the same imaging session provides anatomical context. Using the nonobese diabetic mouse, an established model of type 1 diabetes, 19F MRI data were acquired showing the early homing behavior of diabetogenic T cells to the pancreas. A computational algorithm provided T cell counts in the pancreas. Approximately 2% of the transferred cells homed to the pancreas after 48 hr. The technique allows for both unambiguous detection of labeled cells and quantification directly from the in vivo images. The in vivo quantification and cell trafficking patterns were verified using 19F spectroscopy and fluorescence microscopy in excised pancreata. The labeling procedure did not affect T‐cell migration in vivo. This imaging platform is applicable to many cell types and disease models and can potentially be used for monitoring the trafficking of cellular therapeutics. Magn Reson Med 58:725–734, 2007. © 2007 Wiley‐Liss, Inc.
Quantitative description of the asymmetry in magnetization transfer effects around the water resonance in the human brain
Authors: Hua Jun , Jones Craig K. , Blakeley Jaishri , Smith Seth A. , van Zijl Peter C.M. , Zhou Jinyuan 
Published: September 2007

AbstractMagnetization transfer (MT) imaging provides a unique method of tissue characterization by capitalizing on the interaction between solid‐like tissue components and bulk water. We used a continuous‐wave (CW) MT pulse sequence with low irradiation power to study healthy human brains in vivo at 3 T and quantified the asymmetry of the MT effects with respect to the water proton frequency. This asymmetry was found to be a difference of approximately a few percent from the water signal intensity, depending on both the RF irradiation power and the frequency offset. The experimental results could be quantitatively described by a modified two‐pool MT model extended with a shift contribution for the semisolid pool with respect to water. For white matter, this shift was fitted to be 2.34 ± 0.17 ppm (N = 5) upfield from the water signal. Magn Reson Med 58:786–793, 2007. © 2007 Wiley‐Liss, Inc.
TEM transmission line coil with double nuclear capability
Authors: Erickson Matthew G. , Kurpad Krishna N. , Holmes James H. , Fain Sean B. 
Published: September 2007

AbstractMR imaging and spectroscopy requires RF fields of high homogeneity. Quadrature volume coils meeting this requirement include the birdcage coil and the TEM resonator. We describe here a quadrature volume coil designed around a modified coaxial transmission line in which multiple inner conductors are arrayed on a circular perimeter and surrounded by a common shield. Current antinodes are established at appropriate points on the inner conductors by series transmission line stubs, either open circuit or short circuit, which terminate the line. Quadrature phasing is generated by a novel circuit constructed from a pair of high‐performance current baluns and a commercial quadrature hybrid. The coil is a “pure” TEM coil as it is simply a resonant transmission line. There is no mode structure to consider. The construction of a prototype quadrature four‐element coil is described and preliminary test results from this coil in a 4.7T horizontal bore magnet are reported. A related double nuclear coil design for 3He and 1H in which two linear transmission line coils are arrayed on a circular perimeter and simultaneously tuned and matched to their respective frequencies is also described. Preliminary tests from this coil in a 1.5T clinical scanner are reported. Magn Reson Med 58:800–807, 2007. © 2007 Wiley‐Liss, Inc.
Functional contrast based on intermolecular double‐quantum coherences: Influence of the correlation distance
Authors: Schäfer Andreas , Möller Harald E. 
Published: September 2007

AbstractA functional MRI (fMRI) study with visual stimulation of healthy subjects was performed at 3T exploiting intermolecular double‐quantum coherences. The correlation distance, dc, was varied between 60 and 300 μm for different evolution times, τ. Robust activation was obtained in all experiments with average signal changes (ΔS2) = 8.4 ± 0.7% and 9.4 ± 0.8% for τ = 15 and 20 ms, respectively) exceeding those normally associated with conventional blood oxygen level‐dependent (BOLD) fMRI. Relaxation‐rate changes (ΔR2 = 0.33 ± 0.36 s−1 and ΔR2* = 0.77 ± 0.54 s−1) were similar to those commonly obtained for the extravascular BOLD effect. The number of activated voxels increased with increasing dc until a plateau was reached at ≈120 μm. Similar trends were observed for the activation‐induced percent signal change and for the maximal Z‐scores. These effects were quantitatively explained by a reduced sensitivity at short dc due to increasing signal attenuation related to diffusion and an increasing amount of signal fluctuations in the fMRI time series due to imperfect suppression of unwanted coherence pathways. Consistent indications of a preferential selection of susceptibility changes in blood vessels of a particular size were not obtained. Magn Reson Med 58:696–704, 2007. © 2007 Wiley‐Liss, Inc.
Elimination of spatial interference in PRESS‐localized editing spectroscopy
Authors: Kaiser Lana G. , Young Karl , Matson Gerald B. 
Published: September 2007

AbstractUnambiguous detection of γ‐amino butyric acid (GABA) in the human brain is hindered by low concentration and spectral overlap with other metabolites. The popular MEGA‐PRESS (PRESS: point‐resolved spectroscopic sequence) method allows spectral separation of GABA from other metabolites, but suffers from a significant signal‐to‐noise ratio (SNR) reduction due to the 4‐compartment artifact. An alternative PRESS localization technique (PRESS+4) was investigated and compared to MEGA‐PRESS using numerical simulations, phantom, and in vivo experiments. It was shown that while the MEGA‐PRESS method suffers significant signal loss (≈20% for the difference spectrum), GABA signal intensity in PRESS+4 is reduced by only 2% compared to the nonlocalized condition at 4T. The improved method retains important features of the popular MEGA‐PRESS such as additional water suppression and macromolecular elimination as demonstrated in human brain experiments. This method is not limited to GABA J‐difference editing, but can be applied in any PRESS‐based experiments. It should prove particularly useful at higher field, where the 4‐compartment artifact is especially detrimental. Magn Reson Med 58:813–818, 2007. © 2007 Wiley‐Liss, Inc.
A convex optimization procedure to compute ℋ︁2and ℋ︁∞norms for uncertain linear systems in polytopic domains
Authors: Oliveira Ricardo C. L. F. , Peres Pedro L. D. 
Published: September 2007

AbstractIn this paper, a convergent numerical procedure to compute ℋ︁2and ℋ︁∞norms of uncertain time‐invariant linear systems in polytopic domains is proposed. The norms are characterized by means of homogeneous polynomially parameter‐dependent Lyapunov functions of arbitrary degreegsolving parameter‐dependent linear matrix inequalities. Using an extension of Pólya's Theorem to the case of matrix‐valued polynomials, a sequence of linear matrix inequalities is constructed in terms of an integerdproviding a Lyapunov solution for a given degreegand guaranteed ℋ︁2and ℋ︁∞costs whenever such a solution exists. As the degree of the homogeneous polynomial matrices increases, the guaranteed costs tend to the worst‐case norm evaluations in the polytope. Both continuous‐ and discrete‐time uncertain systems are investigated, as illustrated by numerical examples that include comparisons with other techniques from the literature. Copyright © 2007 John Wiley & Sons, Ltd.
Use of benzodiazepines and benzodiazepine receptor agonists during pregnancy: neonatal outcome and congenital malformations
Authors: Wikner Birgitta Norstedt , Stiller Carl‐Olav , Bergman Ulf , Asker Charlotte , Källén Bengt 
Published: September 2007

AbstractBackgroundExposure to Benzodiazepines (BZD) during foetal life has been suggested to contribute to neonatal morbidity and some congenital malformations, for example, orofacial clefts. Here we aimed to study the neonatal outcome and congenital malformations in neonates whose mothers reported use of BZD and/or hypnotic benzodiazepine receptor agonists (HBRA) during pregnancy.MethodsIn the Swedish Medical Birth Register we identified 1979 infants whose mothers (n = 1944) reported use of BZD and/or HBRA in early pregnancy. An additional 401 infants were studied, born to 390 mothers who were prescribed such drugs during late pregnancy. Neonatal outcome including congenital malformations after exposure was compared with that of all births (n = 873 879).ResultsAn increased risk for preterm birth and low birth weight was detected in the exposed population. The rate of relatively major congenital malformations was moderately increased among infants exposed in early pregnancy (adjusted OR = 1.24, 95%CI 1.00–1.55), not explained by known teratogenic maternal co‐medication. A higher than expected number of infants with pylorostenosis or alimentary tract atresia (especially small gut) was found. This was, however, based on only seven infants for each group of malformation without association to any specific BZD or HBRA. The earlier proposed increased risk for orofacial clefts was not confirmed in our study.ConclusionsMaternal use of BZD and/or HBRA may increase the risk for preterm birth and low birth weight and cause neonatal symptoms, but does not appear to have a strong teratogenic potential. The tentative association with pylorostenosis and alimentary tract atresia needs confirmation. Copyright © 2007 John Wiley & Sons, Ltd.
From carbon nanotube coatings to high‐performance polymer nanocomposites
Authors: Bredeau Stéphane , Peeterbroeck Sophie , Bonduel Daniel , Alexandre Michaël , Dubois Philippe 
Published: September 2007

AbstractSince their discovery at the beginning of the 1990s, carbon nanotubes (CNTs) have been the focus of considerable research by both academia and industry due to their remarkable and unique electronic and mechanical properties. Among numerous potential applications of CNTs, their use as reinforcing materials for polymers has recently received considerable attention since their exceptional mechanical properties, combined with their low density, offer tremendous opportunities for the development of fundamentally new material systems. However, the key challenge remains to reach a high level of nanoparticle dissociation (i.e. to break down the cohesion of aggregated CNTs) as well as a fine dispersion upon melt blending within the selected matrices. Therefore, this contribution aims at reviewing the exceptional efficiency of CNT coating by a thin layer of polymer as obtained by an in situ polymerization process catalysed directly from the nanofiller surface, known as the ‘polymerization‐filling technique’. This process allows for complete destructuring of the native filler aggregates. Interestingly enough, such surface‐coated carbon nanotubes can be added as ‘masterbatch’ in commercial polymeric matrices leading to the production of polymer nanocomposites displaying much better thermomechanical, flame retardant and electrical conductive properties even at very low filler loading. Copyright © 2007 Society of Chemical Industry
Sputum antibiotic concentrations: Implications for treatment of cystic fibrosis lung infection
Authors: Moriarty T.F. , McElnay J.C. , Elborn J.S. , Tunney M.M. 
Published: September 2007

AbstractBackgroundThe success of antibiotic therapy may be predicted based on the achievement of pharmacodynamic indices (PDIs), which are determined by the susceptibility of the infecting bacteria and the concentrations of antibiotics achieved at the site of infection. The aim of this study was to determine whether PDIs associated with clinical effectiveness for ceftazidime and tobramycin were achieved at the site of infection in the lungs of cystic fibrosis (CF) patients following intravenous administration during treatment of an acute exacerbation.MethodsSerum and sputum samples were collected from 14 CF patients and the concentration of both antibiotics in the samples determined. The susceptibility of bacteria cultured from sputum samples to both antibiotics alone and in combination was also determined.ResultsA total of 22 Pseudomonas aeruginosa isolates and 4 Burkholderia cepacia complex isolates were cultured from sputum samples with 55% and 4% of isolates susceptible to ceftazidime and tobramycin, respectively. Target PDIs for ceftazidime and tobramycin, an AUC/MIC ratio of 100 and a Cmax/MIC ratio of 10, respectively, were not achieved in serum or sputum simultaneously or even individually for any patient. Although the combination of ceftazidime and tobramycin was synergistic against 20 of the 26 isolates cultured, the concentrations of both antibiotics required for synergy were achieved simultaneously in only 38% of serum and 14% of sputum samples.ConclusionKey PDIs associated with clinical effectiveness for ceftazidime and tobramycin were not achieved at the site of infection in the lungs of CF patients. 2007;42:1008–1017. © 2007 Wiley‐Liss, Inc.
Alterations in cGMP, soluble guanylate cyclase, phosphodiesterase 5, and B‐type natriuretic peptide induced by chronic increased pulmonary blood flow in lambs
Authors: Oishi Peter , Sharma Shruti , Grobe Albert , Azakie Anthony , Harmon Cynthia , Johengen Michael J. , Hsu Jong‐Hau , Fratz Sohrab , Black Stephen M. , Fineman Jeffrey R. 
Published: September 2007

AbstractObjectiveThe objective of the study was to determine alterations in cGMP, soluble guanylate cyclase (sGC), phosphodiesterase type 5 (PDE5), and B‐type natriuretic peptide (BNP), in an animal model of a congenital cardiac defect with increased pulmonary blood flow.DesignProspective, comparative, experimental study.SubjectsLambs, from birth until 8 weeks of age.MethodologyLate gestation fetal lambs underwent in utero placement of an 8 mm aortopulmonary vascular graft (shunt). In shunted and normal age‐matched control lambs, at 2, 4, and 8 weeks of age, cGMP and BNP levels were measured, and sGC subunit and PDE5 protein expression were determined by Western blot analysis and immunohistochemistry.ResultsIn shunted lambs, tissue and plasma cGMP levels were greater than normal throughout the 8‐week study period (P < 0.05). sGCα protein was greater at 2 and 4 weeks (P < 0.05), and sGCβ and PDE5 protein were greater at 4 weeks in shunted lambs (P < 0.05). Plasma BNP levels did not change in normal lambs but increased in shunted lambs by 8 weeks of age (P < 0.05). BNP levels were greater in shunted lambs than normal at 4 and 8 weeks (P < 0.05).ConclusionsAlterations in sGC subunit protein expression during the first post‐natal month, and increased BNP levels during the second post‐natal month contribute to elevations in plasma and lung tissue cGMP in lambs with increased pulmonary blood flow. 2007;42:1057–1071. © 2007 Wiley‐Liss, Inc.
Defect formation in GaN grown on vicinal 4H‐SiC (0001) substrates
Authors: Rudziński M. , Jezierska E. , Weyher J. L. , Macht L. , Hageman P. R. , Borysiuk J. , Rödle T. C. , Jos H. F. F. , Larsen P. K. 
Published: September 2007

AbstractWe report a comparative study of wurtzite GaN epilayers prepared by Metal Organic Chemical Vapor Deposition on 4H‐SiC substrates of orientation vicinal to the (0001) (misorientation 0°, 3.4°, and 8°). Structural analysis using X‐ray diffraction, defect‐selective etching methods, and (High Resolution‐) Transmission Electron Microscopy provides direct evidence for a higher number of defects in GaN epilayers grown on the 8° misoriented substrate compared to the 3.4° and 0° misoriented substrates. We found strong differences in morphology of the GaN epilayers and in type and density of the defects formed during growth on both vicinal and nominally exact oriented SiC substrates. The formation of clusters of defects and the non‐uniform distribution of strain, resulting in preferential cracking of the GaN films along the [11$ \bar 2 $0] direction, are both results of growth on misoriented substrates. Based on experimental results, the growth mechanism is discussed and a model explaining the defect formation is proposed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ammoniated solvation of excess electrons on molecular surfaces
Authors: Jalbout Abraham F. 
Published: September 2007

AbstractAs previously asserted, we have proposed a set of hypothetical molecular surfaces that possessed an extended hydrogen‐bonded network on one of the sides and hydrogen atoms on the opposite side. The uneven distribution of the OH groups (which increases the total dipole moment of the system) coupled to the partial positive charge of the hydrogen atoms creates charge pockets capable of trapping excess electrons. In this work we consider the ability of ammonia (NH3) in solvating excess electrons in charge pockets on molecular surfaces. The anions are stable with respect to vertical electron detachment, and serve as another example by which electrons can be solvated on molecular surfaces. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Trapping excess electrons in charge pockets on molecular surfaces in an argon matrix
Authors: Jalbout Abraham F. 
Published: September 2007

AbstractRecently, we have proposed a series of hydrocarbon molecular surfaces (A.F. Jalbout, L. Adamowicz, Mol Phys 2006, 19, 3101), which had a hydrogen bonded network of OH groups on one side of the surface and hydrogen atoms on the opposite side. The addition of these OH groups increases the dipole moment of the system allowing for excess electrons to attach to the surface in dipole‐bound (DB) anion states. We have used this principle to study the interaction of the DB anions formed from the surfaces and an argon atom. The resulting anions are shown to be stable with respect to electron detachment. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Formation of simple organic molecules in the interstellar medium
Authors: Jalbout Abraham F. , Contreras‐Torres Flavio F. , De Leon Aned 
Published: September 2007

AbstractIn this work we present a methodology for the synthesis of simple molecules from basic formaldehyde (H2CO) precursors. We have approached this challenging problem by considering a basic dimerization scheme that eventually leads to diose and methyl formate, using an HCO+ proton source. This species was chosen due to its ample abundance in the atmosphere. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Correction
Authors: Shinomoto Shigeru , Koyama Shinkuke 
Published: September 2007

Abstract‘A solution to the controversy between rate and temporal coding’ by Shigeru Shinomoto and Shinsuke Koyama (Statistics in Medicine, this issue. DOI: 10.1002/SIM.2932). The authors would like to correct Figure 1, for which the wrong rasters were put in (a), (b) and (c), and present here the corrected figure.
1. Corrected figure.magnified image1. Corrected figure.
Pelvic arterial pseudoaneurysm—a rare complication of Cesarean section: diagnosis and novel treatment
Authors: Kovo M. , Behar D. J. , Friedman V. , Malinger G. 
Published: September 2007

AbstractAn uncommon cause of delayed postpartum hemorrhage is a pseudoaneurysm of the uterine artery. Pelvic arterial pseudoaneurysm is generally treated by laparotomy and hemostatic sutures or by uterine artery embolization. We describe two cases of late postpartum hemorrhage following Cesarean section, attributed to pelvic arterial pseudoaneurysm, that were successfully treated by direct thrombin injection under ultrasound guidance. Percutaneous or transvaginal ultrasound‐guided direct thrombin injection is a simple procedure that does not require any sophisticated surgical or radiological equipment. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Uterine artery Doppler at 11 + 0 to 13 + 6 weeks in the prediction of pre‐eclampsia
Authors: Plasencia W. , Maiz N. , Bonino S. , Kaihura C. , Nicolaides K. H. 
Published: September 2007

AbstractObjectiveTo determine the performance of screening for pre‐eclampsia (PET) by maternal characteristics and uterine artery pulsatility index (PI) at 11 + 0 to 13 + 6 weeks' gestation.MethodsIn women with singleton pregnancies attending for routine care at 11 + 0 to 13 + 6 weeks' gestation we recorded maternal variables and measured the uterine artery PI. We identified 107 cases that subsequently developed PET and 5041 that were unaffected by PET, gestational hypertension or delivery of newborns with birth weight below the 10th centile. A multivariate Gaussian model was fitted to the distribution of log multiples of the median (MoM) PI in the PET and unaffected groups. Likelihood ratios for log MoM PI were computed and used together with maternal variables to produce patient‐specific risks for each case. Predicted detection rates (DR) and false‐positive rates (FPR) were calculated by taking the proportions with risks above a given risk threshold.ResultsIn the unaffected group log MoM PI was influenced by maternal ethnic origin, body mass index, previous history of PET and fetal crown–rump length. In the prediction of PET significant contributions were provided by log MoM PI, ethnic origin, body mass index and previous and family history of PET. For an FPR of 10% the DRs of all PET and PET leading to delivery before 34 weeks' gestation by log MoM PI and maternal variables were 61.7% and 81.8%, respectively.ConclusionMaternal variables together with uterine artery PI at 11 + 0 to 13 + 6 weeks' gestation provide sensitive prediction of the development of PET, especially of severe early‐onset PET. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Studies of the refractive indices of binary wax mixtures
Authors: Concetta Waller Sister M. , Angelice Seibert Sister M. 
Published: September 2007

SummaryThe greatest deviations in refractive index from ideal behavior of the binary wax mixtures are obtained with mixtures of vegetable waxes. These are waxes with higher unsaturation, waxes containing a higher percentage of hydroxy esters, and waxes containing glycerides or combinations of these.Melting points and refractive indices at the melting points can be determined simultaneously with the Abbe‐56 refractometer.
Large euenantiornithine birds from the Cretaceous of southern France, North America and Argentina
Authors: WALKER C. A. , BUFFETAUT E. , DYKE G. J. 
Published: September 2007

AbstractWe review historical approaches to the systematics of Enantiornithes, the dominant birds of the second half of the Mesozoic, and describe the forelimb remains of a new Cretaceous euenantiornithine. This taxon is known on the basis of fossil specimens collected from southern France, Argentina and the United States; such a wide geographical distribution is uncharacteristic for Enantiornithes as most taxa are known from single localities. Fossils from the Massecaps locality close to the village of Cruzy (Hérault, southern France), in combination with elements from New Mexico (USA) and from the Argentine locality of El Brete (Salta Province) testify to the global distribution of large flighted euenantiornithine birds in the Late Cretaceous. We discuss the systematics and taxonomy of additional isolated bones of Enantiornithes that were collected from the Argentine El Brete locality in the 1970s; the presence of these flying birds in Cretaceous rocks on both sides of the equator, in both northern and southern hemispheres, further demonstrates the ubiquity of this avian lineage by the latter stages of the Mesozoic.