bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucleotide variants within the IQGAP1 gene in diffuse‐type gastric cancers
Authors: Morris Leah E. , Bloom George S. , Frierson Henry F. , Powell Steven M. 
Published: December 2004

AbstractIQGAP1 is recognized as a negative regulator of cell–cell adhesion at adherens junctions in several cell types, including gastric mucosal cells. The histopathologic appearance of diffuse gastric carcinoma is defined by non‐ or poorly cohesive tumor cells, indicating abnormal intercellular adhesion. Hence, we screened 38 gastric cancers for activating point mutations in IQGAP1. In 2 of the 33 diffuse gastric cancers, there was a missense nucleotide change predicted to alter the amino acid sequence in the GAP‐related domain, which includes part of the binding site for the activated small G proteins Cdc42 and Rac1. Many intronic IQGAP1 gene changes were observed, and several occurred more frequently in diffuse‐type gastric cancers than in intestinal‐type gastric cancers. A highly variable pentanucleotide repeat was identified in the final intron of IQGAP1. The most expanded six‐repeat sequence was present exclusively in diffuse‐type gastric cancers. Additionally, 19 diffuse cases and two intestinal cases exhibited silent coding region nucleotide alterations. Taken together, our results suggest that IQGAP1 coding sequence mutations are not a frequent event in gastric cancer, but do occur in a subset of diffuse‐type gastric carcinomas. Additional studies analyzing other proteins involved in cell adhesion may lead to a better molecular understanding of the histopathologic appearance of diffuse gastric cancers. © 2004 Wiley‐Liss, Inc.
Performance of steady‐state free precession for imaging carotid artery disease
Authors: Zavodni Anna E. , Emery Derek J. , Wilman Alan H. 
Published: December 2004

AbstractPurposeTo evaluate steady‐state free precession (SSFP) for diagnosing carotid artery disease.Materials and MethodsFollowing bilateral x‐ray angiography, seven patients with suspected carotid artery disease were imaged with SSFP, black blood fast spin echo (BB FSE), and time‐of‐flight MR angiography (TOF MRA). The techniques were compared for characterizing the vessel lumen. Flow phantom experiments were also performed, using speeds of 0 to 40 cm/second, to further evaluate the merits of each MR technique.ResultsIn the patient studies, of the 14 arteries available, a correct grading of stenosis was possible with SSFP in 9 of 14, FSE in 12 of 14, and TOF in 13 of 14, assuming x‐ray angiography as the gold standard. The SSFP technique was the least reliable and had severe artifacts in 5 of 14 arteries, making these images nondiagnostic. The flow phantom demonstrated that although the SSFP technique performs well under slow or no flow, it breaks down at higher flow levels.ConclusionThe continuous SSFP sequence used here was not reliable for imaging carotid artery disease owing to artifact in many cases. Nevertheless, the high speed of this SSFP technique does allow it to serve as a rapid scouting method prior to a more detailed evaluation with other MRI methods. J. Magn. Reson. Imaging 2005;21:86–90. © 2004 Wiley‐Liss, Inc.
Differentiation between hepatic cyst and hemangioma: Additive value of breath‐hold, multisection fluid‐attenuated inversion‐recovery magnetic resonance imaging using half‐Fourier acquisition single‐shot turbo‐spin‐echo sequence
Authors: Sasaki Katsumi , Ito Katsuyoshi , Koike Shinji , Fujita Takeshi , Okazaki Hajime , Matsunaga Naofumi 
Published: December 2004

AbstractPurposeTo evaluate the additive value of breath‐hold, multisection fluid‐attenuated inversion‐recovery (FLAIR) magnetic resonance imaging (MRI) using half‐Fourier acquisition single‐shot turbo‐spin‐echo (HASTE) sequence as supplements to moderately and heavily T2‐weighted fast‐spin‐echo (FSE) sequences in differentiating hepatic cyst from hemangioma.Materials and MethodsA total of 183 lesions (127 hepatic cysts, 56 hepatic hemangiomas) in 117 patients were evaluated in this study. Three radiologists independently reviewed FLAIR MR images using a HASTE sequence and T2‐weighted FSE MR images. Each radiologist used a five‐point scale to rate his confidence in determination of hepatic cyst and hemangioma.ResultsAll three reviewers were significantly better able to differentiate hepatic cyst from hepatic hemangioma with the combination of FLAIR imaging using HASTE and moderately and heavily T2‐weighted FSE images (area under the receiver operating characteristic (ROC) curve, 0.99 for each reader) than with moderately and heavily T2‐weighted FSE images alone (0.82–0.93; P < 0.05). FLAIR‐HASTE imaging in addition to T2‐weighted FSE sequences improved the diagnostic performance, including the sensitivity, specificity, accuracy, and confident diagnosis in the differentiation between hepatic hemangiomas and cysts.ConclusionFLAIR‐HASTE imaging is useful for distinguishing hepatic hemangioma from hepatic cyst without the use of contrast‐enhanced MR images. J. Magn. Reson. Imaging 2005;21:29–36. © 2004 Wiley‐Liss, Inc.
Wash‐in kinetics for gadolinium‐enhanced magnetic resonance imaging of carotid atheroma
Authors: Wasserman Bruce A. , Casal Suzette G. , Astor Brad C. , Aletras Anthony H. , Arai Andrew E. 
Published: December 2004

AbstractPurposeTo determine the wash‐in kinetics of intravenous gadolinium into the fibrous cap and lipid core of carotid atheroma, and identify the time following gadolinium administration that maximizes contrast between the cap and core.Materials and MethodsSeven subjects with carotid artery stenosis were studied. Magnetic resonance (MR) images of the atheroma were acquired using a single‐inversion‐recovery fast‐spin‐echo (IR FSE) sequence, which was serially repeated during the first 30 minutes following intravenous gadolinium administration. Postcontrast time was divided into three intervals: <10, 11–20, and >21 minutes. Adjusted signal intensity (SI), signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) values for postcontrast images were compared to adjusted precontrast values.ResultsThe mean SNRs of the cap and core were significantly elevated in each postcontrast interval compared with mean precontrast values. The CNRs of the cap vs. the core increased by 19.8% (3.03 to 4.14, P = 0.03) in the first 10 minutes following gadolinium administration, and remained elevated over the next two intervals with a slight decrease in the final interval.ConclusionIncreased signal and contrast between the cap and core can be achieved by imaging up to 30 minutes following gadolinium administration, with peak enhancement occurring in the first 10 minutes. J. Magn. Reson. Imaging 2005;21:91–95. © 2004 Wiley‐Liss, Inc.
Combined tag tracking and strain reconstruction from tagged cardiac MR images without user‐defined myocardial contours
Authors: Deng Xiang , Denney Thomas S. 
Published: December 2004

AbstractPurposeTo develop an unsupervised method for measuring quantitative three‐dimensional regional strain in the left ventricular wall from tagged cardiac MR images.Materials and MethodsA total of 10 normal human volunteers and eight patients with myocardial infarction were imaged using a parallel tagged imaging protocol. Each study was analyzed using the combined tag tracking and strain reconstruction (COTTER) algorithm. In contrast to existing techniques, which first track tag lines independently in each slice, then reconstruct myocardial deformation, the COTTER algorithm fits a three‐dimensional cardiac deformation model directly to the image data. This approach ensures that tag line positions identified in the image data are consistent from slice to slice. A total of 10 imaging studies (six normals, four patients) were used to optimize parameters of the COTTER algorithm.ResultsIn the remaining eight imaging studies, the root‐mean‐square difference between tags tracked by COTTER and user‐supervised analysis was 0.66 pixels at end‐systole. The correlation coefficient between circumferential shortening strains at end‐systole computed by COTTER and user‐supervised analysis was 0.84 (P < 0.005) at the midwall.ConclusionThe COTTER algorithm can compute accurate measurements of three‐dimensional regional strain without user supervision. J. Magn. Reson. Imaging 2005;21:12–22. © 2004 Wiley‐Liss, Inc.
First‐pass contrast‐enhanced magnetic resonance angiography in humans using ferumoxytol, a novel ultrasmall superparamagnetic iron oxide (USPIO)‐based blood pool agent
Authors: Li Wei , Tutton Sean , Vu Anthony T. , Pierchala Linda , Li Belinda S.Y. , Lewis Jerome M. , Prasad Pottumarthi V. , Edelman Robert R. 
Published: December 2004

AbstractPurposeTo evaluate the feasibility of first‐pass contrast‐enhanced magnetic resonance angiography (MRA) using ferumoxytol in humans.Materials and MethodsFirst‐pass and equilibrium phase MRA were performed using ferumoxytol in one healthy volunteer and 11 patients with a fast three‐dimensional spoiled gradient recalled (SPGR) pulse sequence. The examined vessels included carotid arteries, thoracic aorta, abdominal aorta, and peripheral arteries. A dose of either 71.6 μmol Fe/kg (n = 9), or 35.8 μmol Fe/kg (n = 3) was used. Based on a phantom study, the agent with initial concentration of 537.2 μmol Fe/mL was diluted by either four‐fold (134.3 μmol Fe/mL) or eight‐fold (67.1 μmol Fe/mL) for first‐pass MRA.ResultsAll subjects completed their studies without adverse events. First‐pass MRA showed selective arterial enhancement, with both arterial and venous enhancement on delayed acquisitions. Selective venous enhancement could be obtained by subtraction of arterial phase images from equilibrium phase images. The findings in ferumoxytol MRA were consistent with the results of original vascular tests.ConclusionOur preliminary experience supports the feasibility of first‐pass MRA with ferumoxytol. Satisfactory arterial enhancement during first‐pass imaging is obtained with injection of diluted contrast agent. With ferumoxytol, arteries and veins can be selectively depicted in a single exam. J. Magn. Reson. Imaging 2005;21:46–52. © 2004 Wiley‐Liss, Inc.
Prevention of third molar tooth development in neonate rat with a long pulse diode laser
Authors: Silvestri Anthony R. , Mirkov Mirko G. , Connolly Raymond J. 
Published: December 2004

AbstractBackground and ObjectivesThird molars (wisdom teeth) in humans have limited functional value and cause a high frequency of morbidity. A window of opportunity exists to stop their development. The purpose of this study is to evaluate whether a long pulse diode laser can selectively prevent third molar development in a rat animal model.Study Design/Materials and MethodsThe study calculated theoretical diode laser parameters and irradiated 2‐ to 4‐day‐old rat pups in the posterior aspects of the oral cavity near the time of tooth bud initiation. Rats were sacrificed at 35–50 days and examined intraorally and radiographically for third molar development. Control and treated sides were compared histologically.ResultsNearly half of the maxillary third molars and 80% of the mandibular third molars were selectively prevented from developing using a 20 W diode laser with infrequent, minor adverse effects on maxillary jaw growth.ConclusionsThis study confirms the hypothesis that controlled, non‐invasive laser treatment delivered on the surface of the oral mucosa near the site of tooth bud formation can selectively achieve third molar agenesis. It also offers hope that further innovative studies may bring about a safe, non‐invasive laser treatment to selectively prevent third molar development in humans. Lasers Surg. Med. 35:385–391, 2004. © 2004 Wiley‐Liss, Inc.
Low level laser irradiation stimulates mitochondrial membrane potential and disperses subnuclear promyelocytic leukemia protein
Authors: Gavish Lilach , Asher Yael , Becker Yechiel , Kleinman Yosef 
Published: December 2004

AbstractBackground and ObjectivesLow level laser irradiation (LLLI) is used to promote wound healing. Molecularly it is known to stimulate mitochondrial membrane potential (MMP), cytokine secretion, and cell proliferation. This study was designed to determine the influence of LLLI on the kinetics of MMP stimulation and decay, specific cytokine gene expression, and subcellular localization of promyelocytic leukemia (PML) protein on HaCaT human keratinocytes.Study Design/Material and MethodsThe cells were irradiated by a 780 nm titanium–sapphire (Ti–Sa) laser with 2 J/cm2 energy density. MMP was monitored with Mitotracker, a mitochondrial voltage‐sensitive fluorescent dye. Cytokine gene expression was carried out using semi‐quantitative‐reverse transcription polymerase chain reaction. Subcellular localization of PML protein, a cell‐cycle checkpoint protein, was determined using immunofluorescent staining.ResultsThe fluorescence intensity of MMP was increased immediately after the end of LLLI by 148 ± 6% over control (P<0.001). Subsequently it decayed, reaching 51 ± 14% of the control level (P < 0.01) within 200 minutes. This decay was characterized by an exponential curve (R = 0.96) with a lifetime of 79 ± 36 minutes (P < 0.05). Following irradiation, the expression of interleukin‐1α, interleukin‐6, and keratinocyte growth factor (KGF) genes were transiently upregulated; but the expression of the proinflammatory gene interleukin‐1β, was suppressed. The subnuclear distribution of PML was altered from discrete domains to its dispersed form within less than 1 hour after LLLI.ConclusionsThese changes reflect a biostimulative boost that causes a shift of the cell from a quiescent to an activated stage in the cell cycle heralding proliferation and suppression of inflammation. Further characterization of MMP kinetics may provide a quantitative basis for assessment of the effect of LLLI in the clinical setting. Lasers Surg. Med. 35:369–376, 2004. © 2004 Wiley‐Liss, Inc.
Examination of candidate genes in language disorder: A model of genetic association for treatment studies
Authors: Haines Jonathan , Camarata Stephen 
Published: December 2004

AbstractThe purpose of this review is to provide a model for studying genetic association of response to intervention in child language disorders. In addition to a theoretical overview and review of different approaches to studying candidate genes, a specific methodology for completing this type of analysis is presented. The goal of the analysis is to provide detail beyond simple broad phenotyping for affected and nonaffected individuals and to take advantage of data yielded from concise behavioral phenotyping often available in treatment studies. © 2004 Wiley‐Liss, Inc. MRDD Research Reviews 2004;10:208–217.
Morphology of poly(p‐oxybenzoyl) prepared in perfluoropolyether
Authors: Kimura Kunio , Ohmori Hideki , Uchida Tetsuya , Yamashita Yuhiko 
Published: December 2004

AbstractSolvent effect on the morphology of poly(p‐oxybenzoyl) (POB) prepared by the reaction‐induced phase separation of oligomers was examined by the polymerization of p‐acetoxybenzoic acid in perfluoropolyether AflunoxTM (AFL2507 and AFL606). Polymerization was carried out at 320°C for 6 hr. POB microspheres were formed in AFL2507 by the liquid–liquid phase separation of oligomers due to the low miscibility of oligomers in AFL2507. The molecular weight of the solvent influenced the morphology, and the polymerization in AFL606 of which the molecular weight was lower than AFL2507 yielded whiskers formed by crystallization of oligomers induced by the increase in miscibility compared with that in AFL2507. The solvent structure and its molecular weight influenced the miscibility of oligomers and ultimately controlled the morphology from whisker to microsphere. Copyright © 2004 John Wiley & Sons, Ltd.
Adhesion of an aromatic thermosetting copolyester with copper foils
Authors: Huang Yongqing , McCormick John J. , Economy James 
Published: December 2004

AbstractCopper foils have been widely used in microelectronic devices. Adequate adhesion between copper foils to various substrates, such as Si, SiO2, polyimide, is crucial to high performance of these devices. The adhesion between a new high temperature adhesive, aromatic thermosetting copolyester (ATSP), and various copper foils, namely, zinc(Zn)‐coated copper foil, copper foil and nickel (Ni)‐coated copper foil was characterized by a 90° peel strength test. It was found that the peel strength of Zn‐coated copper foil to ATSP was 1050 N/m, which was more than three times higher than copper foil and five times that of Ni‐coated copper foil. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS) studies indicated that this higher adhesion results from the stronger mechanical interlocking due to the rougher surface of Zn‐coated copper foil, and from chemical reactions at the interface which occur during the curing process of ATSP on the Zn‐coated copper surface. In contract to the adhesive failure at the ATSP/Cu and ATSP/Ni interfaces, the failure mechanism of ATSP/Zn is both cohesive and adhesive. Copyright © 2004 John Wiley & Sons, Ltd.
Surface tailoring of an ethylene propylene diene elastomeric terpolymer via plasma‐polymerized coating of tetramethyldisiloxane
Authors: Tran Nguyen D , Choudhury Namita R , Dutta Naba K 
Published: December 2004

AbstractIn the research presented here, we explore the use of a low‐energy plasma to deposit thin silicone polymer films using tetramethyldisiloxane (TMDSO) (H(CH3)2SiOSi(CH3)2H) on the surface of an ethylene propylene diene elastomeric terpolymer (EPDM) in order to enhance the surface hydrophobicity, lower the surface energy and improve the degradation/wear characteristics. The processing conditions were varied over a wide range of treatment times and discharge powers to control the physical characteristics, thickness, morphology and chemical structure of the plasma polymer films. Scanning electron microscopy (SEM) shows that pore‐free homogeneous plasma polymer thin films of granular microstructure composed of small grains are formed and that the morphology of the granular structure depends on the plasma processing conditions, such as plasma power and time of deposition. The thicknesses of the coatings were determined using SEM, which confirmed that the thicknesses of the deposited plasma‐polymer films could be precisely controlled by the plasma parameters. The kinetics of plasma‐polymer film deposition were also evaluated. Contact angle measurements of different solvent droplets on the coatings were used to calculate the surface energies of the coatings. These coatings appeared to be hydrophobic and had low surface energies. X‐ray photoelectron spectroscopy (XPS) and photoacoustic Fourier‐transform infrared (PA‐FT‐IR) spectroscopy were used to investigate the detailed chemical structures of the deposited films. The optimum plasma processing conditions to achieve the desired thin plasma polymer coatings are discussed in the light of the chemistry that takes place at the interfaces. Copyright © 2004 Society of Chemical Industry
Morphology and properties of poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐para‐phenylene vinylene]/silica nanoparticle hybrid films
Authors: Yu Yang‐Yen , Chen Wen‐Chang 
Published: December 2004

AbstractPoly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐para‐phenylene vinylene] (MEH‐PPV)/silica nanoparticle hybrid films were prepared and characterised. Three kinds of materials were compared: parent MEH‐PPV, MEH‐PPV/silica (hybrid A films), and MEH‐PPV/coupling agent MSMA/silica (hybrid B films), in which MSMA is 3‐(trimethoxysilyl) propyl methacrylate. It was found that the hybrid B films could significantly prevent macrophase separation, as evidenced by scanning electron and fluorescence microscopy. Furthermore, the thermal characteristics of the hybrid films were largely improved in comparison with the parent MEH‐PPV. The UV‐visible absorption spectra suggested that the incorporation of MSMA‐modified silica into MEH‐PPV could confine the polymer chain between nanoparticles and thus increase the conjugation length. The photoluminescence (PL) studies also indicated enhancement of the PL intensity and quantum efficiency by incorporating just 2 wt% of MSMA‐modified silica into MEH‐PPV. However, hybrid A films did not show such enhancement of optoelectronic properties as the hybrid B films. The present study suggests the importance of the interface between the luminescent organic polymers and the inorganic silica on morphology and optoelectronic properties. Copyright © 2004 Society of Chemical Industry
Homolytic bond dissociation energies of 4‐substituted bicyclo[2.2.2]octanyl compounds: inductive/field effects on the stabilities of organic radicals
Authors: Fu Yao , Liu Lei , Liu Rui , Guo Qing‐Xiang 
Published: December 2004

AbstractThe inductive/field effects on homolytic bond dissociation energies (BDEs) were studied for the first time using substituted 4‐X‐bicyclo[2.2.2]octane‐Y—Z systems. A variety of very different chemical bonds (i.e. Z—Y: Z = CH2, NH, O, SiH2, PH, S; Y = H, F, Li) were considered, and popular substituents including H, CH3, F, OH, NH2, SH, CN and NO2 were utilized. High‐quality BDE values were obtained for the first time for many bicyclo[2.2.2]octane systems from carefully calibrated G3B3/B3LYP calculations. Significant effects of the substituents at the 4‐position of bicyclooctane were found for the Z—Y BDEs of bicyclooctanyl‐Z—Y systems. Nice Hammett‐type correlations were obtained for these substituent effects using the inductive/field F constants. It was found that the reaction constants (i.e. ρ values) of the Hammett correlations varied dramatically from −1.96 to +23.01 kJ mol−1 for different Z—Y systems: The ρ values for the Z—H BDEs were about ∼1.0–5.0 kJ mol−1; the ρ values for the Z—F BDEs were about −2.0 to −1.0 kJ mol−1; the ρ values for the Z—Li BDEs were ∼13.0–23.0 kJ mol−1. The substituent effects on both the stability of the parent molecules before homolysis and the stability of the radical products after homolysis were demonstrated to be important for the BDEs. It was shown that the inductive/field substituent effects on BDEs could not be explained by the electronegativity or bond polarity theories. Nevertheless, we developed a theoretical model on the basis of the classic electrostatic theories for the inductive/field effects. This model successfully explained the intriguing inductive/field substituent effects on BDEs. Copyright © 2004 John Wiley & Sons, Ltd.
Kinetics of the homogeneous, unimolecular elimination reactions of ethyl oxamate, ethyl N,N‐dimethyloxamate and ethyl oxanilate in the gas phase
Authors: Chacin Esker V. , Tosta María , Herize Armando , Domínguez Rosa M. , Alvarado Ysaias , Chuchani Gabriel 
Published: December 2004

AbstractThe gas‐phase elimination kinetics of the title compounds were determined over the temperature range 350–430°C and pressure range 35–240 Torr (1 Torr = 133.3 Pa). The reactions, which were carried out in a static reactor system, seasoned with allyl bromide and in the presence of a free radical inhibitor, are homogeneous, unimolecular and obey a first‐order rate law. The temperature dependences of the overall rate coefficients are given by the following Arrhenius equations: for ethyl oxamate, log [k1 (s−1)] = (13.28 ± 0.20) – (203.7 ± 2.5) kJ mol−1 (2.303RT)−1, for ethyl N,N‐dimethyloxamate, log [k1 (s−1)] = (13.06 ± 0.34) – (206.8 ± 4.4) kJ mol−1(2.303RT)−1, and for ethyl oxanilate, log [k1 (s−1)]= (13.86 ± 0.12)–(207.4 ± 1.5) kJ mol−1(2.303RT)−1. The overall rates, the partial rates and the kinetic and thermodynamic parameters of these eliminations are presented and discussed. These reactions appear to proceed through moderately polar cyclic transition states. Copyright © 2004 John Wiley & Sons, Ltd.