bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of perfusion fMRI using a numerical model of arterial spin labeling that accounts for dynamic transit time effects
Authors: Hernandez‐Garcia Luis , Lee Gregory R. , Vazquez Alberto L. , Yip Chun‐Yu , Noll Douglas C. 
Published: September 2005

AbstractA new approach to modeling the signal observed in arterial spin labeling (ASL) experiments during changing perfusion conditions is presented in this article. The new model uses numerical methods to extend first‐order kinetic principles to include the changes in arrival time of the arterial tag that occur during neuronal activation. Estimation of the perfusion function from the ASL signal using this model is also demonstrated. The estimation algorithm uses a roughness penalty as well as prior information. The approach is demonstrated in numerical simulations and human experiments. The approach presented here is particularly suitable for fast ASL acquisition schemes, such as turbo continuous ASL (Turbo‐CASL), which allows subtraction pairs to be acquired in less than 3 s but is sensitive to arrival time changes. This modeling approach can also be extended to other acquisition schemes. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Paramagnetic viral nanoparticles as potential high‐relaxivity magnetic resonance contrast agents
Authors: Allen Mark , Bulte Jeff W. M. , Liepold Lars , Basu Gautam , Zywicke Holly A. , Frank Joseph A. , Young Mark , Douglas Trevor 
Published: September 2005

AbstractIn order to compensate for the inherent high threshold of detectability of MR contrast agents, there has been an active interest in the development of paramagnetic nanoparticles incorporating high payloads of Gd3+ with high molecular relaxivities. Toward this end, the protein cage of Cowpea chlorotic mottle virus (CCMV), having 180 metal binding sites, is being explored. In vivo CCMV binds Ca2+ at specific metal binding sites; however, Gd3+ can also bind at these sites. Using fluorescence resonance energy transfer we have characterized the binding affinity of Gd3+ to the metal binding sites by competition experiments with Tb3+. The measured dissociation constant (Kd) for Gd3+ bound to the virus is 31 μM. The T1 and T2 relaxivities of solvent water protons in the presence of Gd3+‐bound CCMV were 202 and 376 mM−1 s−1, respectively, at 61 MHz Larmor frequency. The unusually high relaxivity values of the Gd3+–CCMV are largely a result of the nanoparticle virus size and the large number of Gd3+ ions bound to the virus. These preliminary results should encourage further investigations into the use of viral protein cages as a new platform for MR contrast agents. Magn Reson Med, 2005. Published 2005 Wiley‐Liss, Inc.
S5FP: Spectrally selective suppression with steady state free precession†
Authors: Derbyshire J. A. , Herzka D. A. , McVeigh E. R. 
Published: September 2005

AbstractA method is presented that employs the inherent spectral selectivity of the Steady‐State Free Precession (SSFP) pulse sequence to provide a spectral band of suppression. At TE = TR/2, SSFP partitions the magnetization into two phase‐opposed spectral components. Z‐storing one of these components simultaneously further excites the other, which is then suppressed by gradient crushing and RF spoiling. The Spectrally Selective Suppression with SSFP (S5FP) method is shown to provide significant attenuation of fat signals, while the water signals are essentially unaffected and provide the normal SSFP contrast. Fat suppression is achieved with relatively little temporal overhead (less than 10% reduction in temporal resolution). S5FP was validated using simulations, phantoms, and human studies. Magn Reson Med, 2005. Published 2005 Wiley‐Liss, Inc.
Two‐dimensional, J‐resolved spectroscopic imaging of GABA at 4 Tesla in the human brain
Authors: Jensen J. Eric , Frederick Blaise deB. , Wang Liqun , Brown John , Renshaw Perry F. 
Published: September 2005

AbstractA method for measuring brain gamma‐amino butyric acid (GABA) levels is presented that combines 2D J‐resolved magnetic resonance spectroscopy (J‐MRS) techniques with chemical‐shift imaging (2D‐JMRSI) at 4 Tesla (T). The results of phantom and in vivo experiments agree well in demonstrating that the 2CH2 GABA resonance situated at 2.97 ppm can be resolved from the neighboring creatine (Cr) resonance at 3.03 ppm and quantified. Single‐voxel, J‐resolved standard and metabolite‐nulled in vivo experiments on six healthy subjects reveal a broad component from the underlying macromolecules (MM) that resonates at and around 3.00 ppm, which is estimated to contribute approximately 15% to the J‐resolved GABA resonance in this large voxel at a repetition time (TR) of 4.5 s. With our 2D‐JMSRI at 1.25 s TR, the macromolecule resonance contribution to our GABA measurements is approximated to be 12%. Six healthy human subjects underwent scanning at 4T with this sequence, yielding a global brain GABA concentration of 0.76 ± 0.20 mM after correction for 12% macromolecule contribution. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Biological correlates of diffusivity in brain abscess
Authors: Mishra Asht M. , Gupta Rakesh K. , Saksena Sona , Prasad Kashi N. , Pandey Chandra M. , Rathore Divya , Purwar Ankur , Rathore Ram K.S. , Husain Nuzhat , Jha Deepak K. , Jaggi Ramandeep S. , Husain Mazhar 
Published: September 2005

AbstractRestricted diffusion in brain abscess is assumed to be due to a combination of inflammatory cells, necrotic debris, viscosity, and macromolecules present in the pus. We performed diffusion‐weighted imaging (DWI) on 41 patients with proven brain abscesses (36 pyogenic and five tuberculous), and correlated the apparent diffusion coefficient (ADC) from the abscess cavity with viable cell density, viscosity, and extracellular‐protein content quantified from the pus. On the basis of the correlation between cell density and ADC in animal tumor models and human tumors in the literature, we assumed that the restricted ADC represents the cellular portion in the abscess cavity. We calculated restricted and unrestricted lesion volumes, and modeled cell density over the restricted area with viable cell density per mm3 obtained from the pus. The mean restricted ADC in the cavity (0.65 ± 0.01 × 10–3 mm2/s) correlated inversely with restricted cell density in both the pyogenic (r = −0.90, P = <0.05) and tuberculous (0.60 ± 0.04 × 10–3 mm2/s, r = −0.94, P = <0.05) abscesses. We conclude that viable cell density is the main biological parameter responsible for restricted diffusion in brain abscess, and it is not influenced by the etiological agents responsible for its causation. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
How to investigate oxygen supply, uptake, and utilization simultaneously by interleaved NMR imaging and spectroscopy of the skeletal muscle
Authors: Carlier P. G , Brillault‐Salvat C. , Giacomini E. , Wary C. , Bloch G. 
Published: September 2005

AbstractHuman skeletal muscle perfusion, oxygenation, and high‐energy phosphate distribution were measured simultaneously by interleaved 1H and 31P NMR spectroscopy and 1H NMR imaging in vivo. From these parameters, arterial oxygen supply (DO2), muscle reoxygenation rate, mitochondrial ATP production, and O2 consumption (VO2) were deduced at the recovery phase of a short ischemic exercise bout. In addition, by using a reformulation of the mass conservation law, muscle maximum O2 extraction was calculated from these parameters. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
New insights into the mechanisms of signal formation in RF‐spoiled gradient echo sequences
Authors: Denolin Vincent , Azizieh Céline , Metens Thierry 
Published: September 2005

AbstractRF spoiling is a well established method to produce T1‐weighted images with short repetition‐time gradient‐echo sequences, by eliminating coherent transverse magnetization with appropriate RF phase modulation. This paper presents 2 novel approaches to describe signal formation in such sequences. Both methods rely on the formulation of RF spoiling as a linear increase of the precession angle between RF pulses, which is an alternative to the commonly used quadratic pulse phase scheme. The first technique demonstrates that a steady state signal can be obtained by integrating over all precession angles within the voxel, in spite of the lack of a genuine steady‐state for separate isochromats. This clear mathematical framework allows a straightforward incorporation of off‐resonance effects and detector phase settings. Moreover, it naturally introduces the need for a large net gradient area per repetition interval. In the second step, a modified partition method including RF spoiling is developed to obtain explicit expressions for all signal components. This provides a physical interpretation of the deviations from ideal spoiling behavior in FLASH and echo‐shifted sequences. The results of the partition method in the small flip angle regime are compared with numerical simulations based on a Fourier decomposition of magnetization states. Measurements performed with in vitro solutions were in good agreement with numerical simulations at short relaxation times (T1/TR = 32 and T2/TR = 4); larger deviations occurred at long relaxation times (T1/TR = 114 and T2/TR = 82). Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Immediate early gene activity in song control nuclei and brain areas regulating motivation relates positively to singing behavior during, but not outside of, a breeding context
Authors: Heimovics Sarah A. , Riters Lauren V. 
Published: September 2005

AbstractIn some species, such as songbirds, much is known about how the brain regulates vocal learning, production, and perception. What remains a mystery is what regulates the motivation to communicate. European starlings (Sturnus vulgaris)sing throughout most of the year, but the social and environmental factors that motivate singing behavior differ seasonally. Male song is highly sexually motivated during, but not outside of, the breeding season. Brain areas outside the song control system, such as the medial preoptic nucleus (POM) and ventral tegmental area (VTA), have been implicated in regulating sexually motivated behaviors in birds, including song. The present study was designed to explore whether these regions, as well as three song control nuclei [area X, the high vocal center (HVC), and the robust nucleus of the arcopallium (RA)], might be involved differentially in song produced within compared to outside of a breeding context. We recorded the behavioral responses of breeding and nonbreeding condition male starlings to the introduction of a female conspecific. Males did not show context‐dependent differences in the overall amount of song sung. However, immunocytochemistry for the protein product of the immediate early gene cFOS revealed a positive linear relationship between the total amount of songs sung and number of cFOS‐labeled cells in POM, VTA, HVC, and RA for birds singing during, but not outside of, a breeding context. These results suggest that these regions differentially regulate male song production depending on reproductive context. Overall the data support the hypothesis that the POM and VTA interact with the song control system, specifically HVC and RA, to regulate sexually motivated vocal communication in songbirds. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Health‐related quality of life of children and adolescents prior to hematopoietic progenitor cell transplantation: Diagnosis and age effects
Authors: Barrera Maru , Gee Carolyn , Andrews Gail S. , Armstrong Christine A. , Saunders Fred E. 
Published: September 2005

AbstractBackgroundThe health‐related quality of life (HRQOL) may vary among children before undergoing hematopoietic progenitor cell transplantation (HPCT). This study examined the HRQOL of children scheduled for HPCT, the effects of diagnosis and age on HRQOL, and the convergent validity of one generic and two disease‐specific measures of HRQOL.ProcedureThe sample consisted of 111 children (mean age = 10.4 years) diagnosed with acute lymphoblastic leukemia (ALL; 22%), other leukemias (26%), neuroblastoma (19%), other solid tumors (18%), and hematologic disorders (15%). Convergence validity was tested with 67 children (mean age = 10.3 years) who had an equivalent distribution of diagnoses except for neuroblastoma (12%). The Child Health Questionnaire (CHQ), a generic measure, and the Pediatric Oncology Quality of Life Scale (POQOL) and the Play Performance Scale (PPS), disease‐specific measures, were completed by one parent prior to HPCT.ResultsCompared to the norms for healthy children, the CHQ Physical summary scores for every diagnostic subgroup and the CHQ Psychosocial summary scores for ALL were poorer. Compared to the cancer norms for Total POQOL and PPS scores, scores for ALL and neuroblastoma were the poorest. These measures also revealed that adolescents' HRQOL was perceived to be worse than children's. Total POQOL scores showed strong convergent validity with CHQ Physical and Psychosocial scores and moderate convergent validity with the PPS scores.ConclusionsBased on parental reports, children treated for ALL and neuroblastoma appear to be at the greatest risk for poor HRQOL before undergoing HPCT, and adolescents seem to be more compromised than younger children, based on parental reports. The POQOL measure seems to be the best predictor of HRQOL. These results have clinical implications for the care of children undergoing HPCT. Pediatr Blood Cancer 2006;47:320–326. © 2005 Wiley‐Liss, Inc.
Characterization of the human blood plasma proteome
Authors: Shen Yufeng , Kim Jeongkwon , Strittmatter Eric F. , Jacobs Jon M. , Camp David G. , Fang Ruihua , Tolié Nikola , Moore Ronald J. , Smith Richard D. 
Published: September 2005

AbstractWe describe methods for broad characterization of the human plasma proteome. The combination of stepwise immunoglobulin G (IgG) and albumin protein depletion by affinity chromatography and ultrahigh‐efficiency capillary liquid chromatography separations coupled to ion trap‐tandem mass spectrometry enabled identification of 2392 proteins from a single plasma sample with an estimated confidence level of > 94%, and an additional 2198 proteins with an estimated confidence level of 80%. The relative abundances of the identified proteins span a range of over eight orders of magnitude in concentration (< 30 pg/mL to ∼30 mg/mL), facilitated by the attomole‐level sensitivity of the analysis methods. More than 80% of the observed proteins demonstrate interactions with IgG and/or albumin, and the human plasma protein loss in the affinity chromatography/strong cation exchange/reversed‐phase liquid chromatography‐tandem mass spectrometry methodology was investigated in detail. The results of this study provide a basis for a wide range of plasma proteomics studies, including broad quantitation of relative abundances in comparative studies of the identification of novel protein disease markers, as well as further studies of protein‐protein interactions.
Poly(silarylene–siloxane)polyimides from allyl‐terminated oligoimides and hydride‐functional silarylene–siloxanes via hydrosilylation polymerization
Authors: Homrighausen Craig L. , Kennedy Brent J. , Schutte Erick J. 
Published: September 2005

AbstractThis research was focused on the design and execution of new synthetic routes to low‐temperature‐curable poly(silarylene–siloxane)polyimides. The synthesis of individual oligoimide and silarylene–siloxane blocks was followed by hydrosilylation polymerization to produce crosslinked copolymers. The silarylene–siloxane and polyimide blocks were structurally characterized by IR and 1H NMR spectroscopy and size exclusion chromatography. The high‐temperature resistance of the copolymers was evaluated through the measurement of heat distortion temperatures (THD's) via thermomechanical analysis and by the determination of the weight loss at elevated temperatures via thermogravimetric analysis. Glass‐transition temperatures (Tg's) of the silarylene–siloxane segments were measured by differential scanning calorimetry. Hydrosilylation curing was conducted at 60 °C in the presence of chloroplatinic acid (H2PtCl6). The copolymers displayed both high‐temperature resistance and low‐temperature flexibility. We observed Tg of the silarylene–siloxane segment as low as −77 °C and THD of the polyimide segment as high as 323 °C. The influence of various oligoimide molecular weights on the properties of copolymers containing the same silarylene–siloxane was examined. The effect of various silarylene–siloxane molecular weights on the properties of copolymers containing the same oligoimide was also examined. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4922–4932, 2005
Determinants of colorectal cancer screening behavior among Chinese Americans
Authors: Teng Ellen J. , Friedman Lois C. , Green Charles E. 
Published: September 2005

AbstractColorectal cancer (CRC) is the most commonly diagnosed cancer among Chinese Americans and is the third leading cause of cancer death in this population. The objectives of this study were to determine the rates of CRC screening (via fecal occult blood test (FOBT), flexible sigmoidoscopy (FSIG), and colonoscopy) among Chinese Americans and predictors of utilizing these screening procedures. Participants (N=206) completed a self‐administered questionnaire assessing cancer screening behaviors and beliefs about perceived risk of developing cancer and treatment efficacy. A series of logistic regressions indicated that physician recommendation to obtain CRC screening significantly predicted whether Chinese Americans undergo FOBT, FSIG, or colonoscopy screening (p<0.001). Acculturation and perceived risk of developing CRC did not predict obtaining any of the screening procedures. FOBT was the most commonly reported screening method used by respondents (65%), followed by FSIG (54%) and colonoscopy (49%). These findings highlight the need to make physicians more aware of the impact their recommendations have in determining CRC screening behavior among Chinese Americans. Copyright © 2005 John Wiley & Sons, Ltd.
Patient delay in oral cancer: a qualitative study of patients' experiences
Authors: Scott S.E. , Grunfeld E.A. , Main J. , McGurk M. 
Published: September 2005

AbstractUp to 30% of patients delay seeking the advice of a healthcare professional after self‐discovery of symptom(s) of oral cancer. Reasons for this patient delay are poorly understood. The aim of the present study was to explore patients' initial experiences and reactions to developing symptoms of oral cancer, and to identify factors influencing their decision to consult a health care professional.In‐depth semi‐structured interviews were conducted with 17 consecutive patients who had received a diagnosis of oral squamous cell carcinoma, but had yet to start treatment. Participants were asked about their beliefs about their symptoms over the course of the disease and their decision to seek help. The tape‐recorded interviews were transcribed verbatim and analysed using ‘Framework analysis’.Oral symptoms were rarely attributed to cancer and were frequently interpreted as minor oral conditions. As a result of these beliefs, patients tended to postpone seeking help or fail to be concerned over their symptoms. Prior to seeking help, patients responded to symptoms by using self‐medication, changing the way they ate and disclosing their discovery of symptoms to friends or family. Problems with access to healthcare professionals and patients' social responsibilities acted as barriers to prompt help‐seeking.This study has documented that an individual's interpretation of oral cancer symptoms may be misguided and this can adversely affect subsequent help‐seeking behaviour. Copyright © 2005 John Wiley & Sons, Ltd.
Can agrobiont spiders (Araneae) avoid a surface with pesticide residues?
Authors: Pekár Stano , Haddad Charles R 
Published: September 2005

AbstractIntegrated pest management includes the use of various pesticides that can have a detrimental effect on spiders. A pesticide can express its activity directly or via residues. Most of the attention paid to the impact of pesticides on spiders has investigated the effects of direct exposure. Our aim in this study was to investigate the residual activity (repellency and toxicity) of selected pesticides on six principal species of spider occurring in an apple orchard. Four of these species (Clubiona spp., Pardosa spp., Philodromus spp., Xysticus spp.) are hunting spiders, and two species (Dictyna spp., Theridion spp.) are web‐building. We were interested to see whether these spiders could avoid a surface with residues and to examine their susceptibilities to fresh and 1‐day‐old residues. For this purpose we conducted laboratory experiments using three types of pesticide, an organophosphate, phosalone (Zolone), a pyrethroid, permethrin (Ambush) and Bacillus thuringiensis (Bt; Novodor), which were applied to paper discs or branches. Spiders could choose to stay on any treated paper/branch within a dish. Except for Theridion spp., all species were repelled by fresh residues but not by 1‐day‐old residues. Clubiona spp., Dictyna spp., Pardosa spp. and Xysticus spp were repelled by phosalone and permethrin residues only, whereas Philodromus spp. specimens were repelled also by Bt residues. Theridion spp. avoided contact with residues by making a web on any available branch. Regarding toxicity, neither fresh nor 1‐day‐old residues of phosalone or Bt caused significant mortality to any spider species. In contrast, both fresh and 1‐day‐old residues of permethrin caused significant mortality to all species except for Theridion spp. In conclusion, spiders can recognise and avoid only fresh residues, although older residues might still be toxic to them. Copyright © 2005 Society of Chemical Industry
Development and reproduction of Adalia bipunctata (Coleoptera: Coccinellidae) on eggs of Ephestia kuehniella (Lepidoptera: Phycitidae) and pollen
Authors: De Clercq Patrick , Bonte Maarten , Van Speybroeck Kenny , Bolckmans Karel , Deforce Koen 
Published: September 2005

AbstractDue to growing criticism over the use of non‐indigenous coccinellids, the two‐spot ladybird, Adalia bipunctata (L.), has enjoyed increasing attention for aphid biocontrol in Europe. In the current study, eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, whether or not supplemented with bee pollen, were evaluated as a factitious food for larvae and adults of A. bipunctata. The predator showed slower larval development and lower survival when reared on live pea aphids, Acyrthosiphon pisum (Harris), than on E. kuehniella eggs. Survival on gamma‐irradiated eggs of E. kuehniella was superior to that on frozen flour moth eggs, but other developmental characteristics were similar. Adults of A. bipunctata reared on Ac. pisum were only half as fecund as those offered irradiated or frozen E. kuehniella eggs, but egg hatch was markedly better on live aphids than on flour moth eggs (61 versus 20–27%, respectively). However, when a diet of flour moth eggs was supplemented with frozen moist bee pollen, egg hatch of A. bipunctata was equally as good as on live aphids. Supplementing flour moth eggs with dry pollen did not yield satisfactory results. Only 10% of larvae reached adulthood on moist bee pollen alone and resulting adults weighed less than half as much as those obtained on flour moth eggs. Our findings indicate that A. bipunctata is able to compensate for a suboptimal diet of animal prey by supplementary feeding on flower pollen. It is concluded that pollinivory may be a crucial trait for both the rearing of this natural enemy and its use in biological control programmes. Copyright © 2005 Society of Chemical Industry