bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional delayed gadolinium‐enhanced MRI of cartilage (dGEMRIC) at 1.5T and 3.0T
Authors: McKenzie Charles A. , Williams Ashley , Prasad Pottumarthi V. , Burstein Deborah 
Published: August 2006

AbstractPurposeTo implement and validate a three‐dimensional (3D) T1 measurement technique that is suitable for delayed gadolinium (Gd)‐enhanced MRI of cartilage (dGEMRIC) and can be easily implemented with clinically available pulse sequences at 1.5T and 3.0T.Materials and MethodsA 3D inversion‐recovery prepared spoiled gradient‐echo (IR‐SPGR) imaging pulse sequence with variable TR was used to implement a 3D T1 measurement protocol. The 3D T1 measurements were validated against a gold‐standard single‐slice 2D IR T1 measurement protocol in both phantoms and in vivo, in both asymptomatic volunteers and volunteers with osteoarthritis (OA).ResultsT1 measurements in phantoms showed a statistically significant correlation between the 2D and 3D measurements at 1.5T (R2 = 0.993, P < 0.001) and 3.0T (R2 = 0.996, P < 0.001). In vivo application demonstrated the feasibility of using this 3D IR‐SPGR sequence to evaluate the molecular status of articular cartilage throughout the knee joint with 0.63 × 0.63 × 3.0 mm spatial resolution within a 20‐minute acquisition, even with the measurement parameters set for the higher T1(Gd) of cartilage at 3T (range = 400–900 msec mean T1 within a region of interest (ROI) in cartilage, compared to 200–600 msec mean T1 at 1.5T).ConclusionThis 3D T1 measurement protocol may prove useful for the evaluation and follow‐up of cartilage dGEMRIC indices in clinical studies of OA. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
In vivo cardiovascular catheterization under real‐time MRI guidance
Authors: Zhang Shaoxiong , Rafie Shervin , Chen Yiping , Hillenbrand Claudia M. , Wacker Frank K. , Duerk Jeffrey L. , Lewin Jonathan S. 
Published: August 2006

AbstractPurposeTo test the hypothesis that cardiac and coronary catheterization can be successfully performed under real‐time MR guidance using a conventional x‐ray angiographic catheter.Materials and MethodsCardiac and coronary catheterization was conducted on eight farm pigs using a real‐time True FISP sequence. A pigtail catheter was used for both left‐ and right‐heart catheterizations performed on all eight animals, while an Amplatz or Judkins catheter was used for the right coronary catheterization that was attempted on five animals. The intravascular devices were visualized by means of their native susceptibility artifacts. For right coronary artery catheterizations, 25% diluted gadolinium (Gd) contrast material was injected to confirm engagement of the right coronary artery.ResultsCardiac catheterization of both the right‐ and left‐heart chambers was successfully performed in all eight pigs. In addition, right coronary catheterization was successfully completed in four of the five pigs in which it was attempted. The procedure time for cardiac catheterization was one minute, while the time range required for coronary catheterization was 32–91 minutes.ConclusionThis work demonstrates that MRI‐guided cardiac catheterization using conventional X‐ray angiographic catheters is feasible; however, coronary catheterization with this passive‐tracking technique is limited. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Detection of change in CNS involvement in neuropsychiatric SLE: A magnetization transfer study
Authors: Emmer Bart J. , Steens Stefan C.A. , Steup‐Beekman Gerda M. , van der Grond J. , Admiraal‐Behloul Faiza , Olofsen Hans , Bosma Gerlof P.Th. , Ouwendijk Wiljan J.N. , Huizinga Tom W.J. , van Buchem Mark A. 
Published: August 2006

AbstractPurposeTo assess whether magnetization transfer imaging (MTI) parameters change in correspondence with clinical changes in NPSLE patients.Materials and MethodsNineteen female patients (mean age = 37.5 years, range = 19–64) underwent MTI on at least two separate occasions (mean time between scans = 25.4 months, range = 5.4–52.3 months). Twenty‐four pairs of scans of 19 patients were available. Each patient's clinical course was classified as improved, stable, or deteriorated. Whole‐brain magnetization transfer ratio (MTR) histograms were generated. The peak height of these histograms was used as an estimate of parenchymal integrity. Based on the change in clinical status, paired examinations were grouped and tested for significant differences between the first and second examinations using paired‐samples t‐tests.ResultsFour patients clinically deteriorated, all patients showed a significant peak height decrease (mean decrease = 8.6%, P = 0.02), and in 14 patients with stable disease the peak height did not change significantly (mean increase = 0.4%). Six patients clinically improved, and all showed a significant relative peak height increase (mean increase = 12.0%, P = 0.02).ConclusionThe peak height of whole‐brain MTR histograms corresponds to changes in the clinical status of individual NPSLE patients. This suggests that MTI can be a valuable tool in the clinical assessment of such patients. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Human embryonic stem cell‐derived neural precursors develop into neurons and integrate into the host brain
Authors: Guillaume Daniel J. , Johnson M. Austin , Li Xue‐Jun , Zhang Su‐Chun 
Published: August 2006

AbstractWhether and how in‐vitro‐produced human neural precursors mature and integrate into the brain are crucial to the utility of human embryonic stem (hES) cells in treating neurological disorders. After transplantation into the ventricles of neonatal immune‐deficient mice, hES‐cell‐derived neural precursors stopped expressing the cell division marker Ki67, except in neurogenic areas, and differentiated into neurons and then glia in a temporal course intrinsic to that of human cells regardless of location. The human cells located in the gray matter became neurons in the olfactory bulb and striatum, whereas those in the white matter produced exclusively glia. Importantly, the grafted human cells formed synapses. Thus, the in‐vitro‐produced human neural precursors follow their intrinsic temporal program to produce neurons and glia and, in response to environmental signals, generate cells appropriate to their target regions and integrate into the brain. © 2006 Wiley‐Liss, Inc.
Pituitary adenylate cyclase‐activating polypeptide regulates forebrain neural stem cells and neurogenesis in vitro and in vivo
Authors: Ohta Shigeki , Gregg Christopher , Weiss Samuel 
Published: August 2006

AbstractRecent studies suggest that adult neurogenesis can contribute significantly to recovery from brain damage. As a result, there is strong interest in the field in identifying potentially therapeutic factors capable of promoting increased expansion of endogenous neural stem cell (NSC) populations and increased neurogenesis. In the present study, we have investigated the effects of PACAP on the NSC populations of the embryonic and adult forebrain. Our results demonstrate that the PACAP receptor, PAC1‐R, is expressed by both embryonic and adult NSCs. The activation of PACAP signaling in vitro enhanced NSC proliferation/survival through a protein kinase A (PKA)‐independent mechanism. In contrast, PACAP promoted NSC self‐renewal and neurogenesis through a mechanism dependent on PKA activation. Finally, we determined that the intracerebroventricular infusion of PACAP into the adult forebrain was sufficient to increase neurogenesis significantly in both the hippocampus and the subventricular zone. These results demonstrate PACAP is unique in that it is capable of promoting NSC proliferation/survival, self‐renewal, and neurogenesis and, therefore, may be ideal for promoting the endogenous regeneration of damaged brain tissue. © 2006 Wiley‐Liss, Inc.
Functional magnetic resonance imaging in rodents: Methodology and application to spinal cord injury
Authors: Ramu Jaivijay , Bockhorst Kurt H. , Mogatadakala Kishore V. , Narayana Ponnada A. 
Published: August 2006

AbstractFunctional MRI (fMRI) on spinal cord‐injured rodents at 4 and 8 weeks post injury (PI) is described. The paradigm for fMRI, based on electrical stimulation of rat paws, was automated using an in‐house designed microprocessor‐based controller that was interfaced to a stimulator. The MR images were spatially normalized to the Paxinos and Watson atlas using publicly available digital images of the cryosections. In normal uninjured animals, the activation was confined to the contralateral somatosensory cortex. In contrast, in injured animals, extensive activation, which included structures such as ipsilateral cortex, thalamus, hippocampus, and the caudate putamen, was observed at 4 and 8 weeks PI. Quantitative cluster analysis was carried out to calculate the volumes and centers of activation in individual brain structures. Based on this analysis, significant increase in activation between 4 and 8 weeks was observed only in the ipsilateral caudate putamen and thalamus. These studies suggest extensive and ongoing brain reorganization in spinal cord‐injured animals. © 2006 Wiley‐Liss, Inc.
Fucosyl‐GM1 expression and amyloid‐β protein accumulation in PC12 cells
Authors: Yanagisawa Makoto , Ariga Toshio , Yu Robert K. 
Published: August 2006

AbstractGangliosides, sialic acid‐containing glycosphingolipids, are ubiquitously expressed in all eukaryotic cells and are localized primarily in the plasma membrane. For a rat pheochromocytoma cell line, PC12, which has been used frequently as a model for investigating events leading to neuronal differentiation, it is generally thought that GM1 is a major ganglioside, based on reactivity with the probe cholera toxin B subunit (Ctxb). From a series of biochemical studies, however, it has been reported that no GM1 is expressed in PC12 cells. In this study, we have reevaluated GM1 expression and Ctxb reactivity in PC12 cells and a subcloned line, PC12D cells. Flow cytometric analysis with Ctxb revealed that about 30–50% of PC12 cells were reactive with Ctxb. However, a detailed biochemical analysis showed that PC12 cells express abundantly a different ganglioside, fucosyl‐GM1, instead of GM1, and the reactivity of Ctxb in the PC12 cells actually arose from its interaction with fucosyl‐GM1, which also interacts with this ligand. Because it has been claimed that amyloid‐β protein (Aβ) interacts with GM1 in PC12 cells to provide “seeding” for amyloid to accumulate, we further evaluated this possibility and found that Aβ is mostly likely interacting with fucosyl‐GM1 in this cell line. Our data thus suggest that a specific interaction may occur between Aβ and fucosyl‐GM1 for the accumulation of amyloid in PC12 cells. © 2006 Wiley‐Liss, Inc.
Decline of striatal dopamine release in parkin‐deficient mice shown by ex vivo autoradiography
Authors: Sato Shigeto , Chiba Tomoki , Nishiyama Shingo , Kakiuchi Takeharu , Tsukada Hideo , Hatano Taku , Fukuda Takahiro , Yasoshima Yasunobu , Kai Nobuyuki , Kobayashi Kazuto , Mizuno Yoshikuni , Tanaka Keiji , Hattori Nobutaka 
Published: August 2006

AbstractParkin is the causal gene of autosomal recessive juvenile parkinsonism (AR‐JP). Dopamine (DA) metabolism has been linked to Parkinson's disease (PD). To understand the pathogenesis of AR‐JP, we generated parkin‐deficient mice to assess the status of DA signaling pathway and examine DA release and DA receptor by ex vivo autoradiography. Ex vivo autoradiography using [11C]raclopride showed a clear decrease in endogenous DA release after methamphetamine challenge in parkin‐deficient mice. Furthermore, parkin deficiency was associated with considerable upregulation of DA (D1 and D2) receptor binding in vivo in the striatum and increased DA levels in the midbrain. Our results suggest that dopaminergic neurons could behave abnormally before neuronal death. © 2006 Wiley‐Liss, Inc.
Altered gene activity correlated with long‐term memory formation of conditioned taste aversion in Lymnaea
Authors: Azami Sachiyo , Wagatsuma Akiko , Sadamoto Hisayo , Hatakeyama Dai , Usami Takeshi , Fujie Manabu , Koyanagi Ryo , Azumi Kaoru , Fujito Yutaka , Lukowiak Ken , Ito Etsuro 
Published: August 2006

AbstractThe pond snail Lymnaea stagnalis is capable of learning conditioned taste aversion (CTA) and then consolidating that learning into long‐term memory (LTM) that persists for at least 1 month. LTM requires de novo protein synthesis and altered gene activity. Changes in gene activity in Lymnaea that are correlated with, much less causative, memory formation have not yet been identified. As a first step toward rectifying this situation, we constructed a cDNA microarray with mRNAs extracted from the central nervous system (CNS) of Lymnaea. We then, using this microarray assay, identified genes whose activity either increased or decreased following CTA memory consolidation. We also identified genes whose expression levels were altered after inhibition of the cyclic AMP response element‐binding protein (CREB) that is hypothesized to be a key transcription factor for CTA memory. We found that the molluscan insulin‐related peptide II (MIP II) was up‐regulated during CTA‐LTM, whereas the gene encoding pedal peptide preprohormone (Pep) was down‐regulated by CREB2 RNA interference. We next examined mRNAs of MIP II and Pep using real‐time RT‐PCR with SYBR Green. The MIP II mRNA level in the CNS of snails exhibiting “good” memory for CTA was confirmed to be significantly higher than that from the CNS of snails exhibiting “poor” memory. In contrast, there was no significant difference in expression levels of the Pep mRNA between “good” and “poor” performers. These data suggest that in Lymnaea MIP II may play a role in the consolidation process that forms LTM following CTA training. © 2006 Wiley‐Liss, Inc.
Raman spectra of apatites: La10−x Si6−y (Al,Fe)y O26±δ
Authors: Lucazeau G. , Sergent N. , Pagnier T. , Shaula A. , Kharton V. , Marques F. M. B. 
Published: August 2006

AbstractRaman spectra of eight polycrystalline apatites of the general formula La10−xSi6−yM′yO26 ± δ with M′ = Al or Fe were obtained at 300 K. Raman spectra of La10Si4Fe2O26 and La9.83Si4.5Al1.5O26 were investigated in the range 80–1000 K and 80–623 K, respectively. Tentative assignments of bands to stretching and bending modes of SiO4 tetrahedra and to M'O vibrations are proposed. Except for the two new bands, which appear around 700 cm−1 when Al is replaced by Fe, only some band broadenings and relative intensity changes are observed as a function of the rate of O5 or La vacancies. Most of the bands soften and broaden continuously when raising the temperature. This is an indication that the Al‐ and Fe‐substituted apatites do not undergo any structural change up to 1000 K. Above 1000 K, the broad and weak shoulder observed at 850 cm−1 for La10Si4Fe2O26 is replaced by a strong band at 868 cm−1, suggesting that SiO4 tetrahedra undergo a structural modification. All compounds show the same residual band broadening at 80 K. This suggests that there is a small rate of static disorder preferentially related to the solubility of Al and Fe in the Si sublattice rather than to other defects. Moreover, the observation of FeO modes indicates that the dynamics of the solid solution obeys the so‐called two‐mode behavior. The occurrence of FeO stretching vibrations 150 cm−1 lower than for those of SiO suggests that the coordination number of iron could be larger than 4, particularly for the Fe4+ species. Copyright © 2006 John Wiley & Sons, Ltd.
On the use of conducting polymers to improve the resistance against corrosion of paints based on polyurethane resins
Authors: Iribarren J. I. , Armelin E. , Liesa F. , Casanovas J. , Alemán C. 
Published: August 2006

AbstractThis work analyzes the physical properties of several paints and the resistance against corrosion that they impart after being modified by adding a conducting polymer. Five different formulations were selected: four polyurethane resins (two varnish and two aqueous based) and one multicomponent system containing polyester, melamine and cellulose acetobutyrate. The physical properties of the coatings were examined by FTIR, thermal analyses and viscosity measurements. Corrosion resistance of carbon steel coated with these paints was studied by means of accelerated laboratory tests. The results provided by the original formulations and those modified by adding 1 % w/w of polypyrrole or poly(3‐decylthiophene‐2,5‐diyl) regioregular were compared. Although the general behavior was irregular, showing dependence with the paint formulation, excellent results were achieved for an aqueous based polyurethane resin modified with polypyrrole. Accelerated immersion experiments in salt and acid solutions showed fast degradation of the film without conducting polymer, while the polymeric film with polypyrrole offered a higher resistance.
An EIS study of the effect of the pedant group in imidazolines as corrosion inhibitors for carbon steel in CO2 environments
Authors: Villamizar W. , Casales M. , Gonzales‐Rodriguez J. G. , Martinez L. 
Published: August 2006

AbstractElectrochemical impedance spectroscopy (EIS) measurements were carried out to study the corrosion inhibition of carbon steel in 3 % NaCl with and without diesel saturated with CO2 at 50 °C. The inhibitors examined were hydroxyethyl (HEI‐18), amino ethyl (AEI‐18), and amide ethyl imidazolines (AMEI‐18). When the oily phase, i.e diesel, is absent, the inhibition efficiency of the imidazolines is low, around 80 %. It was found, however, that the inhibition dramatically increased with the presence of the oily phase, because the imidazolines are able to act as both emulsifiers and corrosion inhibitors. Experimental results showed an increase in the film resistance (Rf), charge transfer resistance (Rct), capacitance of the film and the capacitance of the double layer values with the addition of inhibitor in presence of the oily phase also in several orders of magnitude. The most effective inhibitor in presence of diesel is a solution of AMEI‐18, as the oily phase is carried to the surface also. This is due to the presence of two large alkyl groups than the only chain present in the HEI‐18 and AEI‐18 imidazolines with better hydrophobic properties associated with the formation of a protective film that reduces drastically the corrosion process. The effects of the interaction of inhibitors with hydrocarbons and the correlation on the performance of inhibitor films have been examined.
Microbiological influence on the electro‐chemical potential of stainless steel
Authors: Gümpel P. , Arlt N. , Telegdi J. , Schiller D. , Moos O. 
Published: August 2006

AbstractThe microbiologically caused ennoblement appears in natural water on all stainless steels equally and can only be prevented by the use of biocides. Temperature and supply of nutrients have an influence on the increasing rate of the potential, as well as the presence of manganese ions in the water favors the potential rise. The final value of the potential is substantially regulated by the biological system and is independent of the steel composition. An endangerment of stainless steels by a selective corrosion attack e.g. pitting corrosion arises if the critical repassivation potential of the steel lies below the open‐circuit potential appearing in the natural system. This can be due to the alloy composition or due to process‐conditioned weakening of the passive layer, for example by annealing colors on and beside welded joints.
Single‐Step Magnetic Patterning of Iron Nanoparticles in a Semiconducting Polymer Matrix
Authors: Kumar Jitendra , Singh Rajiv K. , Samanta Satya B. , Rastogi Ramesh C. , Singh Ramadhar 
Published: August 2006

AbstractSummary: A cost‐effective chemical synthesis and single‐step magnetic patterning of iron nanoparticles (size ≈100 nm) in a semiconducting P3OT polymer matrix is reported wherein Fe nanostructures (≈150 ± 50 nm) are periodically aligned with π‐conjugated P3OT chains to form a nanomagnet‐semiconductor‐nanomagnet (Fe‐π‐Fe) structure. The resultant periodic patterning has been characterized by XRD, SEM and AFM techniques and is attributed to the intrinsic alignment of Fe at the nanometer‐scale level in a conjugated polymer matrix under the influence of a magnetic field. Such a P3OT/Fe matrix may find application in magnetic memory devices.AFM image in nanometers showing the periodic nanostructuring of P3OT‐Fe matrices when the P3OT‐Fe nanocomposite films were grown under an applied magnetic field.imageAFM image in nanometers showing the periodic nanostructuring of P3OT‐Fe matrices when the P3OT‐Fe nanocomposite films were grown under an applied magnetic field.
A small bandstop microstrip filter for UWB applications
Authors: Hong Seokjin , Lee Heejun , Park Hoon , Choi Jaehoon 
Published: August 2006

AbstractA small bandstop microstrip filter for ultra‐wideband application is proposed. The proposed filter combines the traditional short‐circuited stub highpass filter and the open‐circuited stub bandstop filter on the mitered 50‐Ω microstrip line. The distributed highpass filter scheme is applied to achieve highpass filtering characteristics over ultra‐wideband frequency band (3.1–10.6 GHz) and the open‐circuited stubs are used to obtain the band rejection function at Wireless Local Area Network frequency band. The measured results show that the proposed filter has a wide passband characteristic of 132.12% (2.16–10.57 GHz), with the return loss of less than −10 dB and 3‐dB stop band of 14.37% (5.17–5.97 GHz). The measured group delay is less than 0.65 ns within the passband except the rejection band. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2162–2165, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21887
Optimization of chromatic dispersion measurement technique using relative power of two beating frequencies
Authors: Abdul‐Rashid H. A. , Al‐Qdah M. T. , Chuah H. T. , Tayahi M. , Abdullah M. K. 
Published: August 2006

AbstractOptimization study of the Chromatic Dispersion measurement technique using relative power of two beating frequencies is presented in this paper. The performance of the CD measurement technique is studied in terms of the measurement range and sensitivity as the wavelength separation is varied. Based on the mathematical model and experimental results the technique sensitivity increases with wavelength separation. However, this increase in sensitivity is traded off with narrower measurement range. The measurement technique is optimized at 5.0 GHz wavelength separation with sensitivity of 0.009 (dB/ps/nm) and measurement range of 2500 (ps/nm). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2154–2156, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21893
A 3D hybrid implicit‐explicit FDTD scheme with weakly conditional stability
Authors: Chen Juan , Wang Jianguo 
Published: August 2006

AbstractIn this paper, the hybrid implicit–explicit finite‐difference time‐domain (HIE‐FDTD) algorithm for a two‐dimensional (2D) TE wave is extended to a full three‐dimensional (3D) wave. The weakly conditional stability is verified by numerical simulation results. Numerical formulations of the 3D HIE‐FDTD method are presented and simulation results are compared to those using the conventional 3D finite‐difference time‐domain method. High computation efficiency is obtained by introducing an unequal space increment in different dimensions in the HIE‐FDTD method. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2291–2294, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21898