bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Cryptosporidium parvum oocyst transport in porous media
Authors: Kim Song‐Bae , Corapcioglu M. Yavuz 
Published: July 2004

AbstractCryptosporidium parvum is a protozoan parasite, transmitted through aqueous environments in the form of an oocyst. In this study, a transport model into which sorption, filtration and inactivation mechanisms are incorporated is applied to simulate laboratory column data, and the suitability of a kinetic model to describe the C. parvum oocyst transport and removal in porous media is compared with an equilibrium model. The kinetic model is applied to simulate previous column experimental data and successfully simulates the concentration peak; the late time tailing effect appeared in the breakthrough curves, indicating that the kinetic model is more suitable than the equilibrium one at simulating the fate and transport of the oocysts in porous media. Simulation illustrates that sorption causes retardation along with a tailing in the breakthrough curve. Additionally, filtration acts as a major mechanism of removing the oocysts from the aqueous phase, whereas the role of inactivation in reducing the viable oocyst concentration is minimal. Copyright © 2004 John Wiley & Sons, Ltd.
Active microwave remote sensing for soil moisture measurement: a field evaluation using ERS‐2
Authors: Walker Jeffrey P. , Houser Paul R. , Willgoose Garry R. 
Published: July 2004

AbstractActive microwave remote sensing observations of backscattering, such as C‐band vertically polarized synthetic aperture radar (SAR) observations from the second European remote sensing (ERS‐2) satellite, have the potential to measure moisture content in a near‐surface layer of soil. However, SAR backscattering observations are highly dependent on topography, soil texture, surface roughness and soil moisture, meaning that soil moisture inversion from single frequency and polarization SAR observations is difficult. In this paper, the potential for measuring near‐surface soil moisture with the ERS‐2 satellite is explored by comparing model estimates of backscattering with ERS‐2 SAR observations. This comparison was made for two ERS‐2 overpasses coincident with near‐surface soil moisture measurements in a 6 ha catchment using 15‐cm time domain reflectometry probes on a 20 m grid. In addition, 1‐cm soil moisture data were obtained from a calibrated soil moisture model. Using state‐of‐the‐art theoretical, semi‐empirical and empirical backscattering models, it was found that using measured soil moisture and roughness data there were root mean square (RMS) errors from 3·5 to 8·5 dB andr2values from 0·00 to 0·25, depending on the backscattering model and degree of filtering. Using model soil moisture in place of measured soil moisture reduced RMS errors slightly (0·5 to 2 dB) but did not improver2values. Likewise, using the first day of ERS‐2 backscattering and soil moisture data to solve for RMS surface roughness reduced RMS errors in backscattering for the second day to between 0·9 and 2·8 dB, but did not improver2values. Moreover, RMS differences were as large as 3·7 dB andr2values as low as 0·53 between the various backscattering models, even when using the same data as input. These results suggest that more research is required to improve the agreement between backscattering models, and that ERS‐2 SAR data may be useful for estimating fields‐scale average soil moisture but not variations at the hillslope scale. Copyright © 2004 John Wiley & Sons, Ltd.
Infiltration and solute transport under a seasonal wetland: bromide tracer experiments in Saskatoon, Canada
Authors: Parsons David F. , Hayashi Masaki , van der Kamp Garth 
Published: July 2004

AbstractIn the northern glaciated plain of North America, the duration of surface water in seasonal wetlands is strongly influenced by the rate of infiltration and evaporation. Infiltration also plays important roles in nutrient exchange at the sediment–water interface and groundwater recharge under wetlands. A whole‐wetland bromide tracer experiment was conducted in Saskatchewan, Canada to evaluate infiltration and solute transport processes. Bromide concentrations of surface water, groundwater, sediment pore water and plant tissues were monitored as the pond water‐level gradually dropped until there was no surface water. Hydraulic head gradients showed strong lateral flow from under the wetland to the treed riparian zone during the growing season. The bromide mass balance analysis showed that in early spring, almost 50% of water loss from the wetland was by infiltration, and it increased to about 70% in summer as plants in and around the wetland started to transpire more actively. The infiltration contributed to recharging the shallow, local groundwater under the wetland, but much of it was taken up by trees without recharging the deeper groundwater system. Emergent plants growing in the wetlands incorporated some bromide, but overall uptake of bromide by vegetation was less than 10% of the amount initially released. After one summer, most of the subsurface bromide was found within 40–80 cm of the soil surface. However, some bromide penetrated as deep as 2–3 m, presumably owing to preferential flow pathways provided by root holes or fractures. Copyright © 2004 Crown in the Right of Canada. Published by John Wiley & Sons, Ltd.
Antigenicity and immunogenicity of collagen
Authors: Lynn A.K. , Yannas I.V. , Bonfield W. 
Published: July 2004

AbstractPertinent issues of collagen antigenicity and immunogenicity are concisely reviewed as they relate to the design and application of biomedical devices. A brief discussion of the fundamental concepts of collagen immunochemistry is presented, with a subsequent review of documented clinical responses to devices containing reconstituted soluble or solubilized collagen. The significance of atelocollagen, concerns regarding collagen‐induced autoimmunity, and other relevant topics are also addressed in the context of current understanding of the human immune response to collagen. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 343–354, 2004
Simplified synthesis of 1,1′[14C]‐methylene‐di (2‐naphthol). A radiochemical and kinetic approach
Authors: Angelini Giancarlo , Ursini Ornella , Minetti Patrizia , Celona Diana , De Angelis Francesco 
Published: July 2004

AbstractThe synthesis of the 1,1′[14C]‐methylene‐di‐(2‐naphthol) 2, as the radiolabeled probe of a possible interaction between the β‐amyloid fibrils and the di‐naphthol mojety in the Alzheimer's disease, is reported. Very simple radiochemical procedure, starting from [14C]paraformaldehyde, produced 8.66 MBq of compound 2 at the specific radioactivity of 1.22 TBq/mol. A mechanistic and kinetic approach allowed the comprehension of the right experimental conditions. The stability of compound 2 in acetonitrile solution was investigated, denoting a significative decomposition process through the transient formation of the 1,2‐naphthyne intermediate. Copyright © 2004 John Wiley & Sons, Ltd.
A method for the synthesis of 2‐amino‐4‐fluoro‐bicyclo[3.1.0]hexane‐2,6‐dicarboxylic acid‐[3H2]
Authors: Kuo Fengjiun , Kulanthaivel Palaniappan , Rener Gregory A. , Yi Ping , Wheeler William J. 
Published: July 2004

AbstractA process for double deuterium labeling of an alcohol was developed. The process was utilized in the subsequent tritium labeling of a secondary alcohol with high specific activity (24 Ci/mmol) by reduction of the corresponding ketone using sodium borotritide. The starting ketone was first brominated with pyridinium tribromide; the resulting alpha bromoketone was then reduced in THF/alcohol in the presence of Ni(OAc)2. The alcohol was then converted to 2‐amino‐4‐fluorobicyclo[3.1.0]hexane‐2,6‐dicarboxylic acid‐[3H2], an mGluR agonist. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of the carbon‐14 labeled isotopomers of (R)‐N‐methyl‐3‐[2‐methylphenoxyl]‐benzenepropanamine hydrochloride (atomoxetine hydrochloride, LY139603), and two of its metabolites
Authors: Kuo Fengjiun , Clodfelter Dean K. , Wheeler William J. 
Published: July 2004

AbstractCarbon‐14 labeled StraterraTM (Atomoxetine HCl, LY139603, (‐)‐N‐methyl‐3‐(2‐methylphenoxy)‐benzenepropanamine hydrochloride), a potent inhibitor of the presynaptic norepinephrine transporter, and two of its major metabolites were synthesized. The key component, S‐(+)‐3‐chloro‐l‐phenyl‐l‐propanol‐[1‐14C] was synthesized by Stille coupling of benzoyl chloride‐[carbonyl‐14C] with vinyl tri‐n‐butylstannane, followed by HCl addition to the vinyl ketone, and asymmetric reduction of the ketone by Corey's CBS reagent. Mitsunobu reaction of this S‐(+)‐3‐chloro‐l‐phenyl‐l‐propanol‐[1‐14C] with various phenol derivatives, followed by converting the chloride to amines, gave desired products. Copyright © 2004 John Wiley & Sons, Ltd.
Request form history, clinical indication, and yield of brain magnetic resonance studies
Authors: Pack Jason R. , Yuh William T.C. , Sonnad J.R. , Maley Joan E. , Petropoulou Kalliopi , Wegner Kenneth F. , Loftus Christopher M. , Mayr Nina A. , Whitehead Donald P. , Maier Gerald J. 
Published: July 2004

AbstractPurposeTo investigate whether improved clinical history allows the radiologist to better predict the pretest probability of obtaining a positive or negative result from a magnetic resonance (MR) examination.Materials and MethodsSix neuroradiologists prospectively reviewed 100 consecutive requests for brain MR examinations and sequentially assessed 1) quality of written history, 2) degree of indication for requested study, and 3) any pertinent new information found during chart review that may have altered the degree of indication. MR yield was correlated with the degree of indication assessed before and after chart review.ResultsMost request form histories were judged as poor (63%), and chart review reduced the overall indications for MR examinations, as there was a tendency for high‐indication requests to migrate to the low‐indication category. Based on request form history alone, the yields for low‐ and high‐indication studies were 13% and 37%, respectively. Correlations between MR yield and indication after chart review improved significantly (P < 0.05) with 2% and 61% for low and high indications, respectively. Sensitivity and specificity for a positive MR yield were 71% and 62%, respectively, for the indication judged by the request history alone, and 96% and 80%, respectively, after chart review. Positive and negative prediction rates were 37% and 87%, respectively, for the indication judged by the request history alone, and 61% and 98%, respectively, for the indication judged after chart review.ConclusionBased on our limited data, most request form histories were inadequate, and essential information available in the chart before MR examinations was frequently missing from the request forms. When adequate information was provided, the indication for the studies as judged by the radiologists predicted the MR yield more accurately, particularly for those requests with low indication. Therefore, our study suggests that MR imaging (MRI) may be used more effectively when pertinent clinical history is available. However, our study is limited and further studies are needed to confirm our results. J. Magn. Reson. Imaging 2004;20:228–232. © 2004 Wiley‐Liss, Inc.
Development of brain infarct volume as assessed by magnetic resonance imaging (MRI): Follow‐up of diffusion‐weighted MRI lesions
Authors: Ritzl Afra , Meisel Stephanie , Wittsack Hans‐Jörg , Fink Gereon R. , Siebler Mario , Mödder Ulrich , Seitz Rüdiger J. 
Published: July 2004

AbstractPurposeTo investigate the development of ischemic brain lesions, as present in the acute stroke phase, by diffusion‐weighted magnetic resonance imaging (DWI), and in the subacute and chronic phases until up to four months after stroke, in fluid‐attenuated inversion recovery (FLAIR)‐ and T2‐weighted (T2W) magnetic resonance (MR) images.Materials and MethodsTwelve consecutive patients with their first middle cerebral artery (MCA) infarction were included. Lesion volumes were assessed on T2W images recorded with a turbo spin echo (TSE) and on images recorded with the FLAIR sequence on average on day 8 and after about four months. They were compared with acute lesion volumes in perfusion and DWI images taken within 24 hours of stroke onset.ResultsOn day 8, lesion volumes in images obtained with FLAIR exceeded the acute infarct volumes in DWI. The chronic lesion volumes were almost identical in T2W and FLAIR images but significantly reduced compared with the acute DWI lesions. The lesion volumes assessed on DWI images correlated highly with the lesions in the images obtained with TSE or FLAIR, as did the lesions in the images obtained with FLAIR and TSE. The secondary lesion shrinkage was accompanied by ventricular enlargement and perilesional sulcal widening, as most clearly visible in the images obtained with FLAIR.ConclusionOur results show that the acute DWI lesions are highly predictive for the infarct lesion in the chronic stage after stroke despite a dynamic lesion evolution most evident in MR images obtained with FLAIR. J. Magn. Reson. Imaging 2004;20:201–207. © 2004 Wiley‐Liss, Inc.
Improved three‐dimensional free‐breathing coronary magnetic resonance angiography using gadocoletic acid (B‐22956) for intravascular contrast enhancement
Authors: Paetsch Ingo , Huber Michael E. , Bornstedt Axel , Schnackenburg Bernhard , Boesiger Peter , Stuber Matthias , Fleck Eckart , Cavagna Friedrich , Nagel Eike 
Published: July 2004

AbstractPurposeTo evaluate gadocoletic acid (B‐22956), a gadolinium‐based paramagnetic blood pool agent, for contrast‐enhanced coronary magnetic resonance angiography (MRA) in a Phase I clinical trial, and to compare the findings with those obtained using a standard noncontrast T2 preparation sequence.Materials and MethodsThe left coronary system was imaged in 12 healthy volunteers before B‐22956 application and 5 (N = 11) and 45 (N = 7) minutes after application of 0.075 mmol/kg of body weight (BW) of B‐22956. Additionally, imaging of the right coronary system was performed 23 minutes after B‐22956 application (N = 6). A three‐dimensional gradient echo sequence with T2 preparation (precontrast) or inversion recovery (IR) pulse (postcontrast) with real‐time navigator correction was used. Assessment of the left and right coronary systems was performed qualitatively (a 4‐point visual score for image quality) and quantitatively in terms of signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), vessel sharpness, visible vessel length, maximal luminal diameter, and the number of visible side branches.ResultsSignificant (P < 0.01) increases in SNR (+42%) and CNR (+86%) were noted five minutes after B‐22956 application, compared to precontrast T2 preparation values. A significant increase in CNR (+40%, P < 0.05) was also noted 45 minutes postcontrast. Vessels (left anterior descending artery (LAD), left coronary circumflex (LCx), and right coronary artery (RCA)) were also significantly (P < 0.05) sharper on postcontrast images. Significant increases in vessel length were noted for the LAD (P < 0.05) and LCx and RCA (both P < 0.01), while significantly more side branches were noted for the LAD and RCA (both P < 0.05) when compared to precontrast T2 preparation values.ConclusionThe use of the intravascular contrast agent B‐22956 substantially improves both objective and subjective parameters of image quality on high‐resolution three‐dimensional coronary MRA. The increase in SNR, CNR, and vessel sharpness minimizes current limitations of coronary artery visualization with high‐resolution coronary MRA. J. Magn. Reson. Imaging 2004;20:288–293. © 2004 Wiley‐Liss, Inc.
Nodule‐in‐nodule appearance of hepatocellular carcinomas: Comparison of gadolinium‐enhanced and ferumoxides‐enhanced magnetic resonance imaging
Authors: Goshima Satoshi , Kanematsu Masayuki , Matsuo Masayuki , Kondo Hiroshi , Kato Hiroki , Yokoyama Ryujiro , Hoshi Hiroaki , Moriyama Noriyuki 
Published: July 2004

AbstractPurposeTo perform comparison of gadolinium‐enhanced and ferumoxides‐enhanced magnetic resonance imaging (MRI) in the detection of nodule‐in‐nodule appearance of hepatocellular carcinomas (HCCs).Materials and MethodsDuring a recent 45‐month period, we had eight patients (five men and three women; age range, 63–84 years; mean, 71 years) with HCCs with nodule‐in‐nodule appearance who underwent gadolinium‐enhanced MRI, ferumoxides‐enhanced MRI, and computed tomography during arterial portography (CTAP) and computed tomography during hepatic arteriography (CTHA), combined and separately, within an interval of two weeks. Two blinded radiologists in consensus retrospectively evaluated three sets of sequences: unenhanced T1‐ and T2‐weighted MR, gadolinium‐enhanced MR, and ferumoxides‐enhanced MR images in random order of patients and imaging sequences. The depiction degree of nodule‐in‐nodule appearance of HCC was evaluated in a semiquantitative fashion. The sensitivities of unenhanced T1‐ and T2‐weighted, gadolinium‐enhanced, and ferumoxides‐enhanced MR images were compared with McNemar's test.ResultsThe eight HCCs with nodule‐in‐nodule appearance ranged in size from 16–26 mm (mean, 20.0 ± 4.0 mm), and there existed nine internal HCC foci ranging in size from 5–14 mm (mean, 7.9 ± 3.5 mm). On gadolinium‐enhanced MR images, the nodule‐in‐nodule appearance of HCC was typically seen as hypervascular foci in an iso‐ or hypovascular area: the depiction degree of nodule‐in‐nodule appearance was distinct in two lesions, equivocal in three, and absent in three. On ferumoxides‐enhanced MR images, it was typically seen as hyperintense foci in a hypointense area: the depiction degree was distinct in four, moderate in one, and absent in three. The sensitivities for detection of nodule‐in‐nodule appearance were 25%, 25%, and 63% on T1‐ and T2‐weighted, gadolinium‐enhanced, and ferumoxides‐enhanced MR images, respectively, but there was no significant difference in sensitivity.ConclusionNodule‐in‐nodule appearance of HCCs can be seen on ferumoxides‐enhanced MR images, in some cases more clearly than on gadolinium‐enhanced MR images, particularly when the background nodule shows hyperintensity on precontrast T1‐weighted images. Ferumoxides‐enhanced MRI may be considered when development of malignant foci is suspected during routine examinations. J. Magn. Reson. Imaging 2004;20:250–255. © 2004 Wiley‐Liss, Inc.
Diffusion anisotropy in subcortical white matter and cortical gray matter: Changes with aging and the role of CSF‐suppression
Authors: Bhagat Yusuf A. , Beaulieu Christian 
Published: July 2004

AbstractPurposeTo determine the relevance of cerebrospinal fluid (CSF)‐suppression for the measurement of diffusion anisotropy in well‐localized areas of the brain, particularly the subcortical white matter (WM) within the gyri and cortical gray matter (GM), in young and elderly subjects, and to assess the changes of water diffusivity in the brain with normal aging.Materials and MethodsQuantitative measures of anisotropy in 26 regions, including subcortical WM (i.e., in the gyri), cortical GM, major deep WM, and deep GM regions of young (21–25 years, N = 8) and elderly (61–74 years, N = 10) normal volunteers, were assessed with CSF‐suppressed diffusion tensor imaging (DTI) relative to standard DTI.ResultsCSF‐suppressed DTI demonstrated significant increases in fractional anisotropy (FA) of 3–12% in the young and 2–14% in the elderly groups with the largest changes being in the subcortical WM of the gyri. Furthermore, FA decreased by 10–19% in the subcortical WM of the gyri of the elderly subjects relative to the young, primarily due to increases in the perpendicular diffusivity, λ3, with age.ConclusionCSF‐suppressed DTI yields more accurate measures of quantitative anisotropy in cortical and subcortical brain regions. Reductions of anisotropy with aging were predominantly observed in subcortical WM of the gyri. J. Magn. Reson. Imaging 2004;20:216–227. © 2004 Wiley‐Liss, Inc.
Evaluation of specific absorption rate as a dosimeter of MRI‐related implant heating
Authors: Baker Kenneth B. , Tkach Jean A. , Nyenhuis John A. , Phillips Michael , Shellock Frank G. , Gonzalez‐Martinez Jorge , Rezai Ali R. 
Published: July 2004

AbstractPurposeTo compare the magnetic resonance imaging (MRI)‐related heating per unit of whole body averaged specific absorption rate (SAR) of a conductive implant exposed to two different 1.5‐Tesla/64 MHz MR systems.Materials and MethodsTemperature changes at the electrode contacts of a deep brain stimulation lead were measured using fluoroptic thermometry. The leads were placed in a typical surgical implant configuration within a gel‐filled phantom of the human head and torso. MRI was performed using two different transmit/receive body coils on two different generation 1.5‐Tesla MR systems from the same manufacturer. Temperature changes were normalized to whole body averaged SAR values and compared between the two scanners.ResultsDepending on the landmark location, the normalized temperature change for the implant was significantly higher on one MR system compared to the other (P < 0.001).ConclusionThe findings revealed marked differences across two MR systems in the level of radiofrequency (RF)‐induced temperature changes per unit of whole body SAR for a conductive implant. Thus, these data suggest that using SAR to guide MR safety recommendations for neurostimulation systems or other similar implants across different MR systems is unreliable and, therefore, potentially dangerous. Better, more universal, measures are required in order to ensure patient safety. J. Magn. Reson. Imaging 2004;20:315–320. © 2004 Wiley‐Liss, Inc.
MRI of helium‐3 gas in healthy lungs: Posture related variations of alveolar size
Authors: Fichele Stanislao , Woodhouse Neil , Swift Andrew J. , Said Zead , Paley Martyn N.J. , Kasuboski Larry , Mills Gary H. , van Beek Edwin J.R. , Wild Jim M. 
Published: July 2004

AbstractPurposeTo probe the variation of alveolar size in healthy lung tissue as a function of posture using diffusion‐weighted helium‐3 hyperpolarized gas imaging.Materials and MethodsMeasurements of the helium‐3 apparent diffusion coefficient (ADC) were made on six healthy subjects. These were used to show the variation of alveolar size between the lowermost dependent regions of the lung compared to the uppermost regions of the lung in four postures: supine, prone, left‐lateral decubitus, and right‐lateral decubitus.ResultsThe distribution of acinar size in the lungs was found to be heterogeneous, and influenced by lung orientation. In nearly all postures, the ADC was significantly higher in the non‐dependent uppermost regions of the lung compared to the dependent lowermost regions of the lung; the greatest variation was found in the left‐lateral decubitus position. The difference in ADC between uppermost and lowermost regions was on average 0.012 cm2second−1, which represents 20% of the average ADC value for the whole lung. A systematic decrease in ADC from the apex of the lung to the base was also found, which corresponds to an inherent gradient in alveolar size.ConclusionThe posture dependent variations in ADC were attributed to compression of the parenchyma under its own weight and the mass of the heart. J. Magn. Reson. Imaging 2004;20:331–335. © 2004 Wiley‐Liss, Inc.