bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperation between antioxidants and 1,25‐dihydroxyvitamin D3 in induction of leukemia HL60 cell differentiation through the JNK/AP‐1/Egr‐1 pathway
Authors: Wang Qing , Salman Hagar , Danilenko Michael , Studzinski George P. 
Published: March 2005

AbstractVitamin D derivatives have demonstrated anti‐cancer activity, but their clinical use is precluded by hypercalcemia. Previously, we found that carnosic acid potentiates differentiation of human leukemia cells induced by low concentrations of 1alpha,25‐dihydroxyvitamin D3 (1,25D3). In this study, we investigated if this effect is a general property of antioxidants, and whether there is a common mechanism whereby antioxidants potentiate monocytic differentiation. We found that all antioxidants tested enhanced differentiation‐related cell cycle arrest induced by a low (1 nM) concentration of 1,25D3. Addition of antioxidants to 1,25D3 activated the JNK pathway as indicated by increased phosphorylation of c‐jun and ATF‐2, although each compound alone had a minimal effect. Antioxidants also enhanced the 1,25D3‐induced AP‐1 DNA binding and transactivation ability. Expression of Egr‐1 and c‐fos was increased by combinations of antioxidants and 1,25D3, in parallel with the activation of the JNK pathway. The potentiation of differentiation by antioxidants was inhibited by JNK inhibitor SP600125 and a dominant negative JNK 1/2 construct, and Egr‐1 and c‐fos expression was proportionally decreased, suggesting that JNK pathway regulates these transcription factors. While potentiating the prodifferentiation effect of 1,25D3, antioxidants did not promote the elevation of basal levels of intracellular calcium by 1,25D3. The results indicate that JNK‐AP1 pathway has an important role in the potentiation of 1,25D3‐induced differentiation by antioxidants, and regulates expression of Egr‐1 and c‐fos. Combinations of antioxidants with 1,25D3 should be further evaluated for use in cancer chemoprevention and therapy. © 2005 Wiley‐Liss, Inc.
Nowhere zero 4‐flow in regular matroids
Authors: Lai Hong‐Jian , Li Xiangwen , Poon Hoifung 
Published: March 2005

AbstractJensen and Toft 8 conjectured that every 2‐edge‐connected graph without a K5‐minor has a nowhere zero 4‐flow. Walton and Welsh 19 proved that if a coloopless regular matroid M does not have a minor in {M(K3,3), M*(K5)}, then M admits a nowhere zero 4‐flow. In this note, we prove that if a coloopless regular matroid M does not have a minor in {M(K5), M*(K5)}, then M admits a nowhere zero 4‐flow. Our result implies the Jensen and Toft conjecture. © 2005 Wiley Periodicals, Inc. J Graph Theory
Late Pleistocene Palaeoenvironments of the Southern Lake Agassiz Basin, USA
Authors: Yansa Catherine H. , Ashworth Allan C. 
Published: March 2005

AbstractMacroscopic plant remains, pollen, insect and mollusc fossils recovered from a cut bank on the Red River in North Dakota, USA, provide evidence that an extensive wetland occupied the southern basin of Lake Agassiz from 10 230 to 9900 14C yr BP. Marsh‐dwelling plants and invertebrates had colonised the surface of a prograding delta during the low‐water Moorhead Phase of Lake Agassiz. A species of Salix (willow) was abundant along distributary channels, and stands of Populus tremuloides (aspen), Ulmus sp. (elm), Betula sp. (birch), and Picea sp. (spruce) grew on the better‐drained sand bars and beach ridges. Most of the species of plants, insects, and molluscs represented as fossils are within their existing geographic ranges. Based on a few species with more northerly distributions, mean summer temperature may have been about 1–2°C lower than the present day. No change in species composition occurred in the transition from the Younger Dryas to Preboreal. At the time that the wetland existed, Lake Agassiz was draining either eastward to the North Atlantic Ocean or northwestward to the Arctic Ocean. The wetland was drowned during the Emerson Phase transgression that resulted in meltwater draining southward to the Gulf of Mexico after 9900 14C yr BP. Copyright © 2005 John Wiley & Sons, Ltd.
An earth systems approach to understanding the tectonic and cultural landscapes of linked marine embayments: Avon‐Heathcote Estuary (Ihutai) and Lake Ellesmere (Waihora), New Zealand
Authors: McFadgen Bruce G. , Goff James R. 
Published: March 2005

AbstractAn earth systems study of the Avon‐Heathcote Estuary (Ihutai), New Zealand, shows that tectonic activity has a marked direct and indirect control upon its geomorphology and human settlement in the area. We discuss the Late Holocene history of the embayment in relation to large earthquakes and their after‐effects. Of particular note is the rapid fluvial transfer of sand to the coast causing dune formation and a more delayed pulse of coarser sediment causing channel avulsion of the Waimakariri River. While dune system development seems to occur soon after tectonic activity, river channel avulsion, spit/barrier formation and ongoing geomorphological changes may well relate to periods of tectonic activity that occurred 100–200 years previously. The interaction between these two sediment delivery systems causes significant, and often rapid, changes to coastal geomorphology and ecosystems that have serious implications for human populations living at or near the coast. We show a more region‐wide picture of the direct and indirect effects of tectonic activity, by comparing two embayments that represent coastal points of entry at opposite ends of the Waimakariri River floodplain: the Avon‐Heathcote Estuary (Ihutai) and Lake Ellesmere (Waihora). Copyright © 2005 John Wiley & Sons, Ltd.
Volcanic ash layers from the Last Glacial Termination in the NGRIP ice core
Authors: Mortensen Anette K. , Bigler Matthias , Grönvold Karl , Steffensen Jørgen P. , Johnsen Sigfús J. 
Published: March 2005

AbstractThe tephrochronological record of the 1400–1640 m depth (∼10 000–16 000 calendar ice core years before present) of the NGRIP ice core has been established by particle screening of selected samples. Ash was identified in 20 samples. Correlation with ice, marine and terrestrial records from volcanic source regions in the northern hemisphere positively identifies the Saksunarvatn Ash and the Vedde Ash (Ash Zone 1). Major element chemistry of the remaining identified ash layers mainly points towards an Icelandic origin. This tephrochronological record provides new important marker horizons for correlating the timing of the climatic changes associated with the Last Glacial Termination within the North Atlantic region, as well as outlining more details concerning the frequency and composition of volcanic eruptions occurring at this deglaciation. Copyright © 2005 John Wiley & Sons, Ltd.
Pleistocene geochronologies for fluvial sedimentary sequences: an archaeologist's perspective
Authors: Hosfield R. T. , Chambers J. C. 
Published: March 2005

AbstractCurrent models of Pleistocene fluvial system development and dynamics are assessed from the perspective of European Lower and Middle Palaeolithic stone tool assemblages recovered from fluvial secondary contexts. Fluvial activity is reviewed both in terms of Milankovitch‐scale processes across the glacial/interglacial cycles of the Middle and Late Pleistocene, and in response to sub‐Milankovitch scale, high‐frequency, low‐magnitude climatic oscillations. The chronological magnitude of individual phases of fluvial activity is explored in terms of radiocarbon‐dated sequences from the Late Glacial and early Holocene periods.It is apparent that fluvial activity is associated with periods of climatic transition, both high and low magnitude, although system response is far more universal in the case of the high magnitude glacial/interglacial transitions. Current geochronological tools do not permit the development of high‐resolution sequences for Middle Pleistocene sediments, while localised erosion and variable system responses do not facilitate direct comparison with the ice core records. However, Late Glacial and early Holocene sequences indicate that individual fluvial activity phases are relatively brief in duration (e.g. 102 and 103 yr). From an archaeological perspective, secondary context assemblages can only be interpreted in terms of a floating geochronology, although the data also permit a reinvestigation of the problems of artefact reworking. Copyright © 2005 John Wiley & Sons, Ltd.
Getting it together: The leadership challenge of mergers and acquisitions
Authors: Stahl Günter K. 
Published: March 2005

AbstractMergers, acquisitions, and strategic alliances are supposed to create new, stronger organizations, but history shows that such combinations often fall far short of expectations. Cross‐border integrations, such as those between Western and Eastern companies, are particularly difficult to manage. Here the CEOs of two multinational firms that have been there talk about the factors that set winning corporate combinations apart from the rest.
Three‐Dimensionally Ordered Macroporous Syndiotactic Polystyrene: Preparation and Characterization
Authors: Yan Weidong , Li Haiqing , Shen Xiaoli 
Published: March 2005

AbstractSummary: Three‐dimensionally ordered macroporous (3DOM) syndiotactic polystyrenes with pore size in the range of 71–286 nm were fabricated by means of silica templates using (dbm)2Ti(OPh)2/MAO catalytic system. The resulting materials were characterized by NMR, SEM, powder X‐ray diffraction, GPC and DSC. The results indicated that the 3DOM syndiotactic polystyrenes were highly syndiotactic, and the pore contraction increased when the average pore diameter decreased. Compared with bulk syndiotactic polystyrenes, 3DOM syndiotactic polystyrene possessed lower molecular weight, narrower molecular weight distribution, and lower crystallinity and melting temperature.SEM image of 3DOM syndiotactic polystyrene, the inset shows the detail of the cavities.imageSEM image of 3DOM syndiotactic polystyrene, the inset shows the detail of the cavities.
Formaldehyde‐Free Wood Adhesives from Decayed Wood
Authors: Li Kaichang , Geng Xinglian 
Published: March 2005

AbstractSummary: Extensive studies using mussel adhesive protein as a formaldehyde‐free, strong, and water‐resistant adhesive model revealed that a combination of a polymer with catechol moieties and a polymer with amino groups could serve as a strong and water‐resistant wood adhesive. This study demonstrated that the treatment of abundant and readily available brown‐rot‐fungus‐decayed wood with NaBH4 followed by mixing with polyethylenimine resulted in a formaldehyde‐free, strong, and water‐resistant wood adhesive.Lignin is demethylated by brown‐rot fungi and then reduced using NaBH4.imageLignin is demethylated by brown‐rot fungi and then reduced using NaBH4.
Chiral Crystal Structure of Racemic Binaphthyl Poly(ether ketone) Macrocycles
Authors: Wang Xing , Liu Na , Cao Hui , Liu Wei , Chen Chunhai , Zhang Wanjin , Wei Yen 
Published: March 2005

AbstractSummary: The crystal structure of rigid, hollow, racemic binaphthyl poly(ether ketone) macrocycles has been elucidated by single crystal X‐ray analysis. Multitudinal interactions were identified within the chiral space group P212121. The structural analysis revealed that this macrocyclic compound contains an elliptic chiral cavity with a size of 9.80 × 5.18 Å, which is similar to that of cyclodextrins. The knowledge about the interaction sites and the structure of the binaphthyl‐based macrocycle provides a unique opportunity to understand its molecular or chiral recognition properties.Space‐filling representation of the single (R)‐macrocycle.imageSpace‐filling representation of the single (R)‐macrocycle.
Solid‐State 1H NMR Studies of Degradable Poly(ethylene oxide) Based Hydrogels
Authors: Naraghi Kaynoush , Meurer Bernard , Lutz Pierre J. 
Published: March 2005

AbstractSummary: Hydrogels, the elastic chains of which are constituted of a short central poly(1,3‐dioxolane) (PDXL) block surrounded by two hydrophilic poly(ethylene oxide) (PEO) blocks, were obtained by free radical homopolymerization of α,ω–methacryloyloxy PEO‐block‐1,3‐PDXL‐block‐PEO macromonomers. The central PDXL block is known to be sensitive to acidic degradation due to the presence of acetal groups. Once swollen to equilibrium, these hydrogels were characterized for their equilibrium swelling degree and their mechanical properties and network degradation studies were carried out.Representation proposed for the breaking of a PEO‐block‐PDXL‐block‐PEO block copolymer.imageRepresentation proposed for the breaking of a PEO‐block‐PDXL‐block‐PEO block copolymer.
E1A‐F is overexpressed early in human colorectal neoplasia and associated with cyclooxygenase‐2 and matrix metalloproteinase‐7
Authors: Boedefeld William M. , Soong Richie , Weiss Heidi , Diasio Robert B. , Urist Marshall M. , Bland Kirby I. , Heslin Martin J. 
Published: March 2005

AbstractStudies suggest the expression of cyclooxygenase‐2 (COX‐2) and matrilysin (MMP‐7) increase in the early stages of colorectal carcinogenesis, however their interaction with other molecular markers is poorly understood. Results from cell line studies and mouse models suggest polyomavirus enhancer activator 3 (PEA3) may play a role in the activation of COX‐2 and MMP‐7 promoters. However, the role of E1A‐F, the human homolog of murine PEA3, in colorectal cancer (CRC) development has not been elucidated. In this study, we used real‐time reverse transcription (RT)‐polymerase chain reaction (PCR) to measure the levels of E1A‐F, COX‐2, and MMP‐7 in matched normal mucosa, adenomas, and/or carcinomas from 128 patients. Our results demonstrate significant overexpression of E1A‐F and MMP‐7 in adenomas and E1A‐F, COX‐2, and MMP‐7 in carcinomas. In carcinomas, E1A‐F expression was significantly associated with both COX‐2 and MMP‐7 overexpression. These results suggest E1A‐F is overexpressed in early stages of human CRC development and may be an important factor in the overexpression of COX‐2 and MMP‐7. © 2005 Wiley‐Liss, Inc.
Ka‐band 1‐W PHEMT MMIC power amplifiers on 2mil‐thick GaAs substrates
Authors: Huang C. W. , Chang S. J. , Wu W. , Wu C. L. , Chang C. S. 
Published: March 2005

AbstractA fully matched Ka‐band wideband pseudomorphic high‐electron‐mobility transistor (PHEMT) 1‐W monolithic millimeter‐wave integrated circuit (MMIC) high‐power amplifier (HPA) without any external circuit is developed. The two‐stage HPAs are prepared on 2‐mil GaAs substrates with a small chip size of 3.46 × 2.9 mm. At least 10‐dB small‐signal gain, 29.5 dBmP−1dB, 31‐dBmPsat, and better than 12‐dB output return loss. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 181–185, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20764
Convergence of Gaussian‐beam modes in corrugated conical horns
Authors: Martín‐Jiménez F. , García E. , O'Sullivan C. , De Haro L. , López Fernández J. A. , Tercero F. , Sierra‐Castañer M. , Martín‐Pintado J. 
Published: March 2005

AbstractGaussian beam‐mode expansion with only the fundamental mode does not work properly when the angular region of interest is wide. It is necessary to use higher‐order mode for the expansion. A study of the convergence of these higher order modes is presented for the case of a corrugated conical horn. Conclusions about the number of modes necessary for good accuracy are given. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 199–203, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20769
Contrast‐enhanced MRI with new biodegradable macromolecular Gd(III) complexes in tumor‐bearing mice
Authors: Zong Yuda , Wang Xinghe , Goodrich K. Craig , Mohs Aaron M. , Parker Dennis L. , Lu Zheng‐Rong 
Published: March 2005

AbstractThe structures of polydisulfide‐based biodegradable macromolecular Gd(III) complexes were modified to improve their in vivo retention time and MRI contrast enhancement. Steric hindrance was introduced around the disulfide bonds to control their access to free thiols in order to alter the degradation rate of the copolymers. Two new macromolecular agents, (Gd‐DTPA)‐cystine copolymers (GDCP) and (Gd‐DTPA)‐cystine diethyl ester copolymers (GDCEP), were prepared. Both agents were readily degraded in vitro and in vivo by the disulfide‐thiol exchange reaction, but at a slow rate. The introduction of COOH and COOEt groups slowed down the degradation of the copolymers in the incubation with 15 μM cysteine. Metabolic degradation products were identified by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry in the urine samples from rats injected with the agents. The T1 relaxivity (r1) was 5.43 mM−1s−1 for GDCP, and 5.86 mM−1s−1 for GDCEP, respectively, at 3T. MRI contrast enhancement of both agents was studied in nude mice bearing MDA‐BM‐231 human breast carcinoma xenografts, on a Siemens Trio 3T scanner. The modified agents resulted in more significant contrast enhancement in the blood pool and tumor periphery than (Gd‐DTPA)‐cystamine copolymers (GDCC) and a low‐molecular‐weight control agent, Gd‐(DTPA‐BMA), at a dose of 0.1 mmol‐Gd/kg. The results demonstrate that the structural modification of the biodegradable macromolecular Gd(III) complexes resulted in a relatively slow degradation of the macromolecules and significantly improved in vivo contrast enhancement. The modified agents show promise for use in investigations of blood pool and cancer by contrast‐enhanced (CE) MRI. Magn Reson Med 53:835–842, 2005. © 2005 Wiley‐Liss, Inc.
Magnetic resonance imaging of inflammation with a specific selectin‐targeted contrast agent
Authors: Boutry Sébastien , Burtea Carmen , Laurent Sophie , Toubeau Gérard , Vander Elst Luce , Muller Robert N. 
Published: March 2005

AbstractE‐selectin‐targeted contrast enhancement of blood vessels in inflamed tissues was investigated with a new contrast agent, Gd‐DTPA‐B(sLex)A, which was recently obtained by grafting a synthetic mimetic of sialyl‐Lewisx, an E‐selectin ligand, onto Gd‐DTPA. The pharmacokinetics, biodistribution, and potential to image inflammation by MRI of this E‐selectin‐targeted contrast agent were evaluated. The inhibition (by 15–34%) produced by Gd‐DTPA‐B(sLex)A on Sialyl Lex‐PAA‐biotin binding to E‐selectin confirmed the specific interaction of the new contrast agent with this adhesion molecule. Gd‐DTPA‐B(sLex)A was tested at a dose of 0.1 mmol/kg b.w. on mice and rats in a fulminant hepatitis model induced by the co‐administration of D‐galactosamine and E. coli lipopolysaccharide. A significant and prolonged contrast enhancement between blood vessels and liver parenchyma was obtained in pathological conditions, which attests to the specificity of the agent for E‐selectin. The prolonged vascular residence (48.9 min in hepatitis vs. 29.8 min in healthy animals), as evidenced by the pharmacokinetic characterization, suggests that Gd‐DTPA‐B(sLex)A interacts with the specific receptors expressed during inflammation. The biodistribution of the compound indicates its retention in inflamed liver by both specific mechanisms and nonspecific accumulation due to the necrotic lesions. The same mechanisms are invoked to account for its retention in the spleen. Magn Reson Med 53:800–807, 2005. © 2005 Wiley‐Liss, Inc.
Numerical solution of the Bloch equations provides insights into the optimum design of PARACEST agents for MRI
Authors: Woessner Donald E. , Zhang Shanrong , Merritt Matthew E. , Sherry A. Dean 
Published: March 2005

AbstractParamagnetic lanthanide complexes that display unusually slow water exchange between an inner sphere coordination site and bulk water may serve as a new class of MRI contrast agents with the use of chemical exchange saturation transfer (CEST) techniques. To aid in the design of paramagnetic CEST agents for reporting important biological indices in MRI measurements, we formulated a theoretical framework based on the modified Bloch equations that relates the chemical properties of a CEST agent (e.g., water exchange rates and bound water chemical shifts) and various NMR parameters (e.g., relaxation rates and applied B1 field) to the measured CEST effect. Numerical solutions of this formulation for complex exchanging systems were readily obtained without algebraic manipulation or simplification. For paramagnetic CEST agents of the type used here, the CEST effect is relatively insensitive to the bound proton relaxation times, but requires a sufficiently large applied B1 field to highly saturate the Ln3+‐bound water protons. This in turn requires paramagnetic complexes with large Ln3+‐bound water chemical shifts to avoid direct excitation of the exchanging bulk water protons. Although increasing the exchange rate of the bound protons enhances the CEST effect, this also causes exchange broadening and increases the B1 required for saturation. For a given B1, there is an optimal exchange rate that results in a maximal CEST effect. This numerical approach, which was formulated for a three‐pool case, was incorporated into a MATLAB nonlinear least‐square optimization routine, and the results were in excellent agreement with experimental Z‐spectra obtained with an aqueous solution of a paramagnetic CEST agent containing two different types of bound protons (bound water and amide protons). Magn Reson Med 53:790–799, 2005. © 2005 Wiley‐Liss, Inc.
Addressing efficiency and residual magnetization cross talk in multi‐slice 2D steady‐state free precession imaging of the heart
Authors: Slavin Glenn S. , Rettmann Dan W. 
Published: March 2005

AbstractThis work presents an efficient method for achieving steady state in multi‐slice 2D balanced steady‐state free precession (SSFP) imaging of cardiac function. With current techniques, data acquisition for each slice is preceded by one or two heartbeats of dummy excitations. Depending on the number of heartbeats required for data acquisition, these dummy heartbeats can represent a large fraction of the total imaging time. As described here, FIESTA‐SP (FIESTA with steady‐state preparation) increases the imaging efficiency to nearly 100% by eliminating dummy heartbeats. Steady state for each slice is achieved using a linear flip angle series of excitations during the first cardiac phase of the first heartbeat for each slice. Because imaging proceeds immediately from one slice to the next, a heretofore‐unseen issue arises where residual magnetization from each slice contaminates subsequent acquisitions. Accelerating the approach to steady state for each slice and eliminating slice cross talk are important for both multi‐slice and interactive real‐time imaging. Magn Reson Med 53:965–969, 2005. © 2005 Wiley‐Liss, Inc.
Generalized scalar measures for diffusion MRI using trace, variance, and entropy
Authors: Özarslan Evren , Vemuri Baba C. , Mareci Thomas H. 
Published: March 2005

AbstractThis paper details the derivation of rotationally invariant scalar measures from higher‐rank diffusion tensors (DTs) and functions defined on a unit sphere. This was accomplished with the use of an expression that generalizes the evaluation of the trace operator to tensors of arbitrary rank, and even to functions whose domains are the unit sphere. It is shown that the mean diffusivity is invariant to the selection of tensor rank for the model used. However, this rank invariance does not apply to the anisotropy measures. Therefore, a variance‐based, general anisotropy measure is proposed. Also an information theoretical parametrization of anisotropy is introduced that is frequently more consistent with the meaning attributed to anisotropy. We accomplished this by associating anisotropy with the amount of orientational information present in the data, regardless of the imaging technique used. Using a simplified model of fibrous tissue, we simulated anisotropy values with varying orientational complexity and tensor models. Simulations suggested that a lower‐rank tensor model may produce artificially low anisotropy values in voxels with complex structure. This was confirmed with a spin‐echo experiment performed on an excised rat brain. Magn Reson Med 53:866–876, 2005. © 2005 Wiley‐Liss, Inc.