bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of hemoglobin vesicles, cellular‐type artificial oxygen carriers, on human umbilical cord blood hematopoietic progenitor cellsin vitro
Authors: Yamaguchi Miki , Fujihara Mitsuhiro , Wakamoto Shinobu , Sakai Hiromi , Takeoka Shinji , Tsuchida Eishun , Azuma Hiroshi , Ikeda Hisami 
Published: February 2008

AbstractHemoglobin vesicles (HbVs), liposomal oxygen carriers containing human hemoglobin, are candidates for development as clinically useful blood substitutes. Although HbVs are shown to distribute transiently into the bone marrow in animal models, the influence of HbVs on human hematopoietic stem/progenitor cells has not yet been studied. Therefore, we investigated the influence of HbVs at a concentration of up to 3 vol/vol % on the clonogenic activity (in semisolid culture) and proliferative activity (in liquid culture) of human hematopoietic progenitor cells derived from umbilical cord blood (CB)in vitro. Continuous exposure of CB mononuclear cells to HbVs tended to decrease the number and size of mature‐committed colonies and most notably reduced the number of colonies of high‐proliferative potential colony‐forming cells (HPP‐CFC). In contrast, exposure to HbVs for 20 h or 3 days, which is more relevant to the clinical setting, had no effect on the number of mature‐committed colonies and only modestly decreased the number of HPP‐CFC. Continuous exposure (10 days) to HbVs significantly suppressed the cellular proliferation and differentiation of both the erythroid and myeloid lineages in liquid culture. Again, short exposure (20 h or 3 days) did not affect these parameters. Thus, our results show that HbVs, under conditions relevant to the clinical setting, have no adverse effect on human CB hematopoietic progenitor activityin vitro. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Doppler sonography of the superior mesenteric artery in children with recurrent abdominal pain
Authors: Koktener Asli , Yilmaz Ayse Esra , Catal Ferat , Eminoglu Sancar 
Published: February 2008

AbstractPurpose.Abdominal pain is one of the most common conditions in childhood and adolescence. The aim of this study was to evaluate the superior mesenteric artery (SMA) Doppler findings in children with recurrent abdominal pain.Method.Duplex Doppler sonographic measurements were performed in 20 patients with recurrent abdominal pain and in 34 controls.Results.The mean blood flow velocities, blood flow volume, and diameter of the SMA were significantly lower in patients with recurrent abdominal pain than in controls.Conclusion.Insufficient development and/or vasoconstriction of the SMA vascular bed may be involved in recurrent abdominal pain, but further studies on larger groups are needed to test this hypothesis. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
Quasi‐one‐dimensional systems: fluctuations, transport and interplay
Authors: Plyukhin A. V. 
Published: February 2008

AbstractIn a one dimensional lattice thermal fluctuations destroy the long‐range order making particles of the lattice move on a scale much larger than the lattice spacing. We discuss the assumption that this motion may be responsible for the transport of localized electrons in a system of weakly coupled chains. The model with diffusing localization sites gives a temperature‐independent mobility with a crossover to an activated dependence at high temperature. This prediction is consistent with and might account for experimental results on discotic liquid crystals and certain biopolymers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Models for transport properties of polymer thin films
Authors: Rentzsch R. , Ionov A. N. 
Published: February 2008

AbstractWe have observed that thin films of different undoped non‐conjugated polymers exhibit high conductivity in metal–polymer–metal (M‐P‐M) structures. Below the critical temperature, Tc of the superconductivity of the contacts, a supercurrent in superconductor–polymer–superconductor (S‐P‐S) structures was obtained. Investigations of the current‐voltage characteristics as a function of contact diameter at different locations on the polymer showed that only in some small channels does a high conductivity appear, whereas at other places a reversible on/off switching was obtained. We postulate that the conductivity effect is connected with the phenomenon of electrification. The electrons or holes are supplied by the electrodes which are in contact with the polymer. These injected charge carriers accumulate in localised states on different locations in the polymer matrix. As a result, a large inner electrical field appears in the polymer giving rise to local changes between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). In the high field region the forbidden gap can vanish, resulting in small channels with a high “metallic‐like” conductivity of the polymer. At present, there exists no theory explaining all the peculiarities of the electrical transport observed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of electronic correlations on the frequency‐dependent hopping transport in Si:P
Authors: Ritz Elvira , Dressel Martin 
Published: February 2008

AbstractAt low energy scales charge transport in the insulating Si:P is dominated by activated hopping between the localized donor electron states. Thus, theoretical models for a disordered system with electron‐electron interaction are appropriate to interpret the electric conductivity spectra.With a newly developed technique we have measured the complex broadband microwave conductivity of Si:P from 100 MHz to 5 GHz in a broad range of phosphorus concentration n /nc from 0.56 to 0.95 relative to the critical value nc = 3:5 × 1018 cm–3 corresponding to the metal‐insulator transition driven by doping.At our base temperature of T = 1.1 K the samples are in the zero‐phonon regime where they show a super‐linear frequency dependence of the conductivity indicating the influence of the Coulomb gap in the density of the impurity states. At higher doping n → nc , an abrupt drop in the conductivity power law σ1(ω) ∼ ωα is observed. The dielectric function ε1 increases upon doping following a power law in (1 – n /nc ). Dynamic response at elevated temperatures has also been investigated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Specific features of the low‐temperature microwave magnetoresistance in nondegenerate p‐Ge
Authors: Veinger A. I. , Zabrodskii A. G. , Tisnek T. V. , Goloshchapov S. I. 
Published: February 2008

AbstractLow‐temperature microwave magnetoristance in lightly doped (nondegenerate) p‐Ge has been studied using the method of electron spin resonance (ESR) by recording the derivative of the microwave absorption with respect to magnetic field. An improvement of the experimental procedure made it possible to precisely determine the position of the zero magnetic field in the field dependence of the derivative and to obtain, by integrating this dependence, the field dependence of the microwave conductivity in the temperature range 10–120 K. A positive magnetoconductance (negative magnetoresistance) and separate manifestation of the magnetoresistances and different temperature dependences of magnetoconductance for light and heavy holes are observed in p‐Ge in weak fields. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Path coupling using stopping times and counting independent sets and colorings in hypergraphs
Authors: Bordewich Magnus , Dyer Martin , Karpinski Marek 
Published: February 2008

AbstractWe analyse the mixing time of Markov chains using path coupling with stopping times. We apply this approach to two hypergraph problems. We show that the Glauber dynamics for independent sets in a hypergraph mixes rapidly as long as the maximum degree Δ of a vertex and the minimum size m of an edge satisfy m ≥ 2Δ + 1. We also show that the Glauber dynamics for proper q‐colorings of a hypergraph mixes rapidly if m ≥ 4 and q > Δ, and if m = 3 and q ≥ 1.65Δ. We give related results on the hardness of exact and approximate counting for both problems. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Ersatz der Rechenbrücke des denkmalgeschützten Rheinkraftwerks Eglisau
Authors: Zerjeski Bernhard , Graf Ernst , Hardock Dieter , Mensinger Martin 
Published: February 2008

AbstractDie neue Außenrechenbrücke am denkmalgeschützten Rheinkraftwerk Eglisau in der Schweiz befindet sich zur Zeit im Bau. Das sechsfeldrige Bauwerk ersetzt die vorhandene ca. 156 m lange Brücke. Während des Baus der Unterwasserpfeiler und der Montage der neuen Brücke soll der Außenrechen möglichst übergangslos von der bestehenden Konstruktion aus gereinigt werden. Die Stromproduktion des Kraftwerks muss während der gesamten Bauzeit und des Querverschubs der Brücke aufrechterhalten werden. Der vorliegende Aufsatz beschreibt die statischen, konstruktiven und montagetechnischen Besonderheiten des zum Teil im Wasser liegenden Bauwerks.
Is three‐dimensional power Doppler ultrasound useful in the assessment of placental perfusion in normal and growth‐restricted pregnancies?
Authors: Guiot C. , Gaglioti P. , Oberto M. , Piccoli E. , Rosato R. , Todros T. 
Published: February 2008

AbstractObjectivesTo investigate three‐dimensional (3D) power Doppler ultrasound indices in the assessment of placental perfusion and their relationship to gestational age (GA), placental position and umbilical artery Doppler flow velocity waveform (FVW) patterns in normal and intrauterine growth‐restricted (IUGR) pregnancies.MethodsForty‐five pregnant women at 23–37 weeks' gestation were studied, of whom 30 had IUGR and 15 were controls. Nine of the IUGR group had normal umbilical FVWs (NED), nine had abnormal patterns but positive end‐diastolic velocities (PED) and 12 had absent or reversed end‐diastolic velocities (AED). Placental position was assessed as being posterior, anterior or lateral. 3D power Doppler indices related to placental perfusion (vascularization index (VI), vascularization flow index (VFI) and flow index (FI)) were obtained from five different sampling sites in each placenta.ResultsVI, VFI and FI were not significantly dependent on GA or placental position. VI and VFI were significantly lower in PED and AED cases compared with controls, while FI was reduced in the AED group only. VI and VFI showed high variability between different sampling sites within each placenta, while the variability of FI was much lower.Conclusions3D power Doppler sonography can provide new insights into placental pathophysiology. FI, which identifies the most severe cases of placental impairment, appears to be the most reliable index because of its low intraplacental variability. Further studies are needed to verify its accuracy when applied in clinical practice as a substitute for or an adjunct to umbilical artery Doppler studies. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
The use of inversion mode and 3D manual segmentation in volume measurement of fetal fluid‐filled structures: comparison with Virtual Organ Computer‐aided AnaLysis (VOCAL™)
Authors: Kusanovic J. P. , Nien J. K. , Gonçalves L. F. , Espinoza J. , Lee W. , Balasubramaniam M. , Soto E. , Erez O. , Romero R. 
Published: February 2008

AbstractObjectiveVolume measurements by three‐dimensional (3D) ultrasonography are considered more accurate than those performed by two‐dimensional (2D) ultrasonography. The purpose of this study was to compare the agreement of three techniques, as well as the inter‐ and intraobserver agreements for volume measurements of fetal fluid‐filled structures.MethodsFifty 3D volume datasets of fetal stomachs and bladders were explored. Volume measurements were performed independently by two observers using: (1) Virtual Organ Computer‐aided AnaLysis (VOCAL™); (2) inversion mode; and (3) ‘manual segmentation’. Reliability was evaluated using intraclass correlation coefficient (ICC), and Bland–Altman plots were generated to examine bias and agreement. The time required to complete the measurements was compared using Student's t‐test or the Wilcoxon Signed Rank Test, and P‐values < 0.025 or < 0.05 were considered statistically significant.ResultsAll volume datasets could be measured using the three techniques. A high degree of reliability was observed between: (1) VOCAL and inversion mode (ICC, 0.995; 95% CI, 0.992–0.997); (2) VOCAL and manual segmentation (ICC, 0.997; 95% CI, 0.995–0.998); and (3) inversion mode and manual segmentation (ICC, 0.995; 95% CI, 0.992–0.997). There was good agreement between VOCAL and inversion mode (mean, − 2.4%; 95% limits of agreement, − 20.1 to 15.3%), VOCAL and manual segmentation (mean, − 8.3%; 95% limits of agreement, − 28.8 to 12.2%) as well as between inversion mode and manual segmentation (mean, 5.9%, 95% limits of agreement: − 14.3 to 26%). Manual segmentation and inversion mode measurements were obtained significantly faster than those by VOCAL.ConclusionsVolume measurements of fetal fluid‐filled structures of relatively regular shape with inversion mode and manual segmentation are feasible. Both techniques have good agreement with VOCAL and are significantly faster than VOCAL. Inversion mode is a reliable method for volume calculations of fluid‐filled organs, whereas manual segmentation can be used when volume measurements by VOCAL or inversion mode are technically difficult to obtain, such as solid structures with poorly defined borders as the volume dataset is rotated, like the uterine cervix. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Establishment of a national database to link epidemiological and molecular data from norovirus outbreaks in Ireland
Authors: KELLY S. , FOLEY B. , DUNFORD L. , COUGHLAN S. , TUITE G. , DUFFY M. , MITCHELL S. , SMYTH B. , O'NEILL H. , McKEOWN P. , HALL W. , LYNCH M. 
Published: February 2008

SUMMARYA prospective study of norovirus outbreaks in Ireland was carried out over a 1-year period from 1 October 2004 to 30 September 2005. Epidemiological and molecular data on norovirus outbreaks in the Republic of Ireland (ROI) and Northern Ireland (NI) were collected and combined in real time in a common database. Most reported outbreaks occurred in hospitals and residential institutions and person-to-person spread was the predominant mode of transmission. The predominant circulating norovirus strain was the GII.4-2004 strain with a small number of outbreaks due to GII.2. This study represents the first time that enhanced epidemiological and virological data on norovirus outbreaks in Ireland have been described. The link established between the epidemiological and virological institutions during the course of this study has been continued and the data is being used as a source of data for the Foodborne Viruses in Europe Network (DIVINE-NET).
Fault stability inferred from granite sliding experiments at hydrothermal conditions
Authors: Blanpied M. L. , Lockner D. A. , Byerlee J. D. 
Published: February 2008

Seismicity on crustal faults is concentrated in the depth interval 1–3 to 12–15km. Tse and Rice (1986) suggested that the lower bound on seismicity is due to a switch with increasing temperature from velocity weakening (destabilizing) to velocity strengthening (stabilizing) friction. They inferred this transition from friction data for dry granite; however, pore fluids exist at elevated temperatures throughout the crust, and may strongly influence strength and sliding behavior. We present new data from sliding experiments on granite at elevated T (23° to 600°) plus elevated PH2O (100 MPa),Our results show velocity strengthening at room temperature, but velocity weakening from 100° to 350°C (except at 250°). From 350° to 600° there are systematic trends from velocity weakening to strong velocity strengthening, and from high to low friction; neither trend was seen in tests on dry granite. The velocity dependence data imply the potential for unstable slip in the interval 100° to 350°. Using a geotherm to map temperature to depth, this interval closely matches the observed earthquake distribution.
Evidence for vertical movement of fluids, Gulf Coast sedimentary basin
Authors: Land Lynton S. 
Published: February 2008

Sediments between 10 and 15 km thick have prograded approximately 400 km into the small oceanic basin which formed along the southern margin of North America subsequent to early Mesozoic rifting. Redistribution of mass during burial diagenesis, and the chemistry of present‐day formation waters in Jurassic through Pleistocene formations document local kilometer‐scale, and in cases basin‐scale vertical fluid transport within the sedimentary wedge.Fluid flow is in part driven by porosity reduction which takes place by both physical and chemical processes during burial. Vertical and horizontal transport also occurs as the result of thermally‐and salinity‐generated buoyancy effects. Input of fluids into the sedimentary wedge from the underlying crust is predicted, but not documented.
Meltwater and Deglaciation, SE Baffin Shelf (NE Margin Laurentide Ice Sheet) Between 13.5 and 7 KA: From O and C Stable Isotopic Data
Authors: Andrews J. T. , Erlenkeuser H. , Evans L. W. , Briggs W. M. , Jull A. J. T. 
Published: February 2008

Stable isotopic values on planktonic foraminifera in a suite of cores from basins across the SE Baffin Shelf are used to extract a record of meltwater events during Termination I deglaciation. Resolution and Hatton basins lie on the SE Baffin Shelf at water depths > 500 m, seaward of major conduits for ice drainage from the eastern sector of the Laurentide Ice Sheet (LIS). Accelerator mass spectrometry 14C dates are used to constrain our chronology of events in ten cores. In Resolution Basin, three cores have 14C AMS dates on foraminifera of > 20 ka at their bases; whereas Hatton Basin cores terminate in sediments < 13 kyr. Sedimentation rates varied between 0.1 to 4.5 m/ka. Stable oxygen and carbon isotopic ratios were obtained on 146 samples of the planktonic foraminifera Neogloboquadrina pachyderma (Ehrenberg) sinistral, from seven of the ten cores. No evidence was found to indicate that test morphology or size affected ∂18O. Between 7 and 13.5 ka the surface water on the shelf was on average 1 ‰ lower than the open ocean signal. Significant temporal variations were found in both ∂18O and ∂13C. Evidence for significant low ∂18O events occurred between 13 and 8 ka. The ∂13C record from the planktonic foraminifera suggests a threefold division of events between 13 and 7 ka, with positive values between 10.8 and 13.0 ka, negative values between 9 and 10.8 ka, and positive values from 7 to 9 ka. The ∂18O data suggest the presence of meltwater on the shelf some 3,000 years prior to the first late glacial dates on terrestrial deglaciation (at circa 10.4 ka).“Hudson Strait must be the real key to the importance of the calving process during deglaciation, because it is potentially the largest marine outlet for the Laurentide Ice Sheet and because it leads into the very center of the ice sheet.....the rates of calving through Hudson Strait during the period of initial ∂18O rise unfortunately are unknown.”W. F. Ruddiman (1987, p. 151)
The recent warming in eastern Minnesota shown by ground temperatures
Authors: Baker Donald G. , Ruschy David L. 
Published: February 2008

Soil and ground (here defined as beyond the depth of weathering or soil) temperatures can be superior to surface temperatures as indicators of climatic trends, because the “noise” common to the latter has been effectively reduced or removed. As a result, the 12.8 m ground temperatures recorded routinely at the University of Minnesota St. Paul campus climatological observatory since 1963 can provide valuable information on climatic trends.The observatory, located in the midst of land that has been in agricultural test plots since 1885, was instrumented with copper‐constantan thermocouples buried at various depths in the soil and ground. The two air temperature measurements, with which the 12.8 m ground temperature is compared, are made with maximum and minimum glass thermometers housed in standard temperature shelters.The mean air temperature increases of 0.049°C and 0.035°C per year, 1963–1990, at the observatory and the nearby Eastern Minnesota station, respectively, compare favorably with the 12.8 m ground temperature mean increase of 0.041°C per year. Due to the brevity of the record and to its approximate coincidence with the most recent northern hemisphere warming period, the extrapolation of these rates beyond the record period must be done with care.
Development, persistence, and variability of upwelling filaments off the Atlantic coast of the Iberian Peninsula
Authors: Haynes R. , Barton E. D. , Pilling I. 
Published: February 2008

The development, persistence, and variability of upwelling filaments off the Atlantic coast of the Iberian Peninsula are examined by means of advanced very high resolution radiometer infrared imagery observed between 1982 and 1990. These observations indicate that the regime is broadly similar to that observed in the California Current system and is closely related to the large scale wind climatology of the subtropical gyre. Upwelling generally starts in late May or early June and persists until late September or early October. In May or June, a narrow band of cold water of quite uniform width is observed along much of the west coast of the Iberian Peninsula. This band has a “fringed” appearance; that is it consists of many narrow “fingers” of cool water extending 20–30 km offshore. The major filament structures generally do not begin to form until late July or August. The filaments appear first as bulges in the upwelling front. These bulges grow offshore to form filaments that reach their maximum length (200–250 km) in September. The lengths of the filaments gradually decrease until the filaments become relatively rare in late October.Typically, five or six fully developed filaments are observed off the Iberian Peninsula late in the upwelling season. Most of these are associated with major topographic features of the region, in particular the large capes which are common to the north and south of the peninsula. It is therefore postulated that the dominant dynamical processes related to filament formation off Iberia is topographic forcing. The exceptions are two major filaments commonly observed along the more regular coastline of northern Portugal. It is hypothesized that these filaments are formed by flow instabilities resulting in meandering of the southward flowing jet. These instabilities may possibly be initiated by the large capes of northern Spain.
Decomposition of N2O over particulate matter
Authors: Rebbert Richard E. , Ausloos Pierre 
Published: February 2008

Nitrous oxide is shown to undergo both a thermal and a photochemical decomposition at 296 K when it is adsorbed on various dry sands. The photochemical process occurs with light of wavelengths greater than 280 nm where gaseous N2O does not absorb. At low pressures (<0.1 torr) the half‐life for the thermal decomposition of nitrous oxide to nitrogen when placed in contact with ∼5 gms of heat treated Tunisian sand in a one‐liter vessel was 350 ± 35 days. Under certain photolytic conditions this half‐life was reduced. The efficiency of the photolytic process for a particular sand depends on the pressure (fraction of surface covered) and on the wave‐length of light. For Tunisian sand at 1.1 torr and with the full mercury arc (>280 nm), the destruction efficiency is ∼2 × 10−5 molecules/incident photon.These results indicate that particulate matter in the troposphere may be responsible for the decomposition of nitrous oxide and hence act as an atmospheric sink for N2O. However, moisture causes a drastic reduction in the number of molecules dissociated per incident photon.