bluuebunny/crossref_metadata_2025_split huggingface dataset:
Virtual frequency encoding: Achieving symmetry in k‐space
Authors: Hinks R. Scott , Derbyshire J. Andrew , Leroux Patrick L. 
Published: March 2007

AbstractChemical shift artifacts and other off‐resonance spatial shifts in 2DFT MRI arise from the linear time dependence in the k‐space data in the readout direction. Introduction of a view‐dependent time shift of the readout window adds a time dependence to the phase‐encoding direction and results in a virtual frequency‐encoding direction that is a linear combination of the phase‐encode and readout axes. By this method, the readout and phase‐encode directions can be made identical in their sensitivity to off‐resonance effects and can be arbitrarily swapped with no change in chemical shift or inhomogeneity effects, improving previously reported methods that swap these axes for signal averaging or reduction of motion artifacts.
Evaluation of extra‐ and intracellular apparent diffusion in normal and globally ischemic rat brain via 19F NMR
Authors: Duong Timothy Q. , Ackerman Joseph J. H. , Ying Howard S. , Neil Jeffrey J. 
Published: March 2007

AbstractThe biophysical mechanism(s) underlying diffusion‐weighted MRI contrast following brain injury remains to be elucidated. Although it is generally accepted that water apparent diffusion coefficient (ADC) decreases after brain injury, it is unknown whether this is associated with a decrease in intracellular or extracellular water displacement, or both. To address this question, 2‐[19F]luoro‐2‐deoxyglucose‐6‐phosphate (2FDG‐6P) was employed as a compartment‐specific marker in normal and globally ischemic rat brain. Through judicious choice of routes of administration, 2FDG‐6P was confined to the intra‐ or extracellular space. There was no statistical difference between intra‐ and extracellular 2FDG‐6P ADCs in normal or in globally ischemic brain (P > 0.16), suggesting that water ADCs in both compartments are similar. However, ischemia did result in a 40% ADC decrease in both compartments (P < 0.001). Assuming that 2FDGbP reflects water motion, this study shows that water ADC decreases in both spaces after ischemia, with the reduction of intracellular water motion being the primary source of diffusion‐weighted contrast.
An optimal and efficient new gridding algorithm using singular value decomposition
Authors: Rosenfeld Daniel 
Published: March 2007

AbstractThe problem of handling data that falls on a nonequally spaced grid occurs in numerous fields of science, ranging from radio‐astronomy to medical imaging. In MRI, this condition arises when sampling under time‐varying gradients in sequences such as echo‐planar imaging (EPI), spiral scans, or radial scans. The technique currently being used to interpolate the nonuniform samples onto a Cartesian grid is called the gridding algorithm. In this paper, a new method for uniform resampling is presented that is both optimal and efficient. It is first shown that the resampling problem can be formulated as a problem of solving a set of linear equations Ax = b, where x and b are vectors of the uniform and nonuniform samples, respectively, and A is a matrix of the sinc interpolation coefficients. In a procedure called Uniform Re‐Sampling (URS), this set of equations is given an optimal solution using the pseudoinverse matrix which is computed using singular value decomposition (SVD). In large problems, this solution is neither practical nor computationally efficient. Another method is presented, called the Block Uniform Re‐Sampling (BURS) algorithm, which decomposes the problem into solving a small set of linear equations for each uniform grid point. These equations are a subset of the original equations Ax = b and are once again solved using SVD. The final result is both optimal and computationally efficient. The results of the new method are compared with those obtained using the conventional gridding algorithm via simulations.
In vivo proton magnetic resonance spectroscopy of the medial temporal lobes of subjects with combat‐related posttraumatic stress disorder
Authors: Freeman Thomas W. , Cardwell David , Karson Craig N. , Komoroski Richard A. 
Published: March 2007

AbstractRecent findings using volumetric MRI techniques have revealed that patients with combat‐related and noncombat‐re‐lated posttraumatic stress disorder (PTSD) have reductions in right hippocampal volume. Twenty‐one veterans with PTSD and eight age‐matched control veterans were studied using proton magnetic resonance spectroscopy to test the hypothesis that the N‐acetyl‐L‐aspartic acidkreatine (NAAICr) ratio would be decreased in the right medial temporal lobe structures of patients with PTSD compared to controls. Patients with PTSD displayed significantly lower NAA/Cr ratio for the right medial temporal lobe relative to the left (P ⩽ 0.011). Patients with PTSD also had lower NNCr in right medial temporal lobe (P ⩽ O.013) and lower choline/Cr in left medial temporal lobe (P ⩽ 0.030) compared to control subjects. Because NAA is regarded as an indicator of neuronal density, this finding suggests that the neuronal density of right‐sided medial temporal structures in patients with combat‐related PTSD may be decreased.
A systematic study of the lactate lineshape in PRESS‐localized proton spectroscopy
Authors: Marshall Ian , Wild James 
Published: March 2007

AbstractJ‐coupled resonances such as lactate exhibit complex behavior in PRESS‐localized spectroscopy. Polarization transfer effects due to nonideal slice profiles can lead to substantial errors in quantification unless recognized. In this work, it is shown how these effects can be predicted in a systematic way given the sequence timing and the RF pulse envelopes. Experimental results are presented to highlight the problems of working at the popular echo time of 2/J.
Monitoring transplanted human mesenchymal stem cells in rat and rabbit bladders using molecular magnetic resonance imaging
Authors: Song Yun Seob , Ku Ja Hyeon 
Published: March 2007

AbstractAimsThis study investigated whether superparamagnetic iron oxide (SPIO)‐labeled human mesenchymal stem cells (hMSCs) may be monitored non‐invasively by in vivo magnetic resonance (MR) imaging with conventional 1.5‐T system examinations in the bladders of rats and rabbits.MethodsSPIO were transferred to hMSCs, using GenePORTER. After SPIO‐labeled hMSCs were transplanted into the animal bladders, serial T2‐weighted MR images and histological examinations were performed over a 4‐week period.ResultshMSCs loaded with SPIO, compared to unlabeled cells, showed similar viability. SPIO‐labeled hMSCs underwent normal chondrogenic, adipogenic, and osteogenic differentiation. For SPIO‐labeled hMSCs concentrations that were greater than 1 × 105, in vitro MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO‐labeled hMSCs in rat and rabbit bladders were decreased and confined locally. After injection of SPIO‐labeled hMSCs into the bladder, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks post‐injection. The presence of iron was confirmed with Prussian blue staining in histological sections.ConclusionsOur findings suggest that hMSCs in animal bladders can be monitored non‐invasively with conventional MR imaging. Neurourol. Urodynam. 26:584–593, 2007. © 2007 Wiley‐Liss, Inc.
Overactive bladder in diabetes: A peripheral or central mechanism?
Authors: Yamaguchi Chiharu , Sakakibara Ryuji , Uchiyama Tomoyuki , Yamamoto Tatsuya , Ito Takashi , Liu Zhi , Awa Yusuke , Yamamoto Kaori , Nomura Fumio , Yamanishi Tomonori , Hattori Takamichi 
Published: March 2007

AbstractAimsTo study diabetic cystopathy with reference to overactive bladder (OAB).MethodsWe retrospectively analyzed diabetic cystopathy in our digitized database that comprised 2300 case records, including data from a lower urinary tract symptoms questionnaire, data from a urodynamic study, and data from neurological examinations.ResultsDiabetic cystopathy was seen in 4% of cases (84 cases): 58 males, 26 females; mean age, 60.8 years; duration of diabetes, 143.5 months; HbA1C, 7.7 %. In addition to large post‐void residual and decreased sensation, OAB, detrusor overactivity (DO), and increased bladder sensation were seen in 55%, 42%, and 14%, respectively. The frequency of DO in patients with increased bladder sensation was 58%. DO increased with age, but not with the duration of diabetes. A brain MRI was performed in 32 cases. The frequency of multiple cerebral infarction (MCI) in patients with DO was 76.5%. The remaining 23.5% of patients with DO had no MCI, and the remaining 42% with increased bladder sensation had no DO.ConclusionsOAB commonly occurs in diabetic cystopathy. Both central and peripheral mechanisms are involved, e.g., MCI due to diabetic cerebral vasculopathy for the DO, and, to a lesser extent, peripheral nerve irritation for the DO and increased bladder sensation. Neurourol. Urodynam. 26:807–813, 2007. © 2007 Wiley‐Liss, Inc.
Test‐retest reliability of an instrumented speculum for measuring vaginal closure force
Authors: Miller J.M. , Ashton‐Miller J.A. , Perruchini D. , DeLancey J.O.L. 
Published: March 2007

AbstractAims:The study aimed to: a) determine reliability of an instrumented speculum designed for measuring intravaginal closure pressure, and b) compare findings with a comparable device reported in the literature. The goal of these new devices is to reduce subjectivity, improve precision, and acknowledge reliability issues in quantifying levator ani closure force acting on the vagina.Methods:The instrumented speculum consisted of two parallel aluminum bills, similar in size to a Peterson speculum. Strain gages located near the root of each bill measure the magnitude of force exerted in the distal vagina. A contraction of the “U‐shaped” levator ani muscle closes the levator hiatus with resultant reaction force measured by the speculum in the mid‐sagittal plane. We tested the device in twelve nulliparous women making repeated measures within and across 3 different visit days. All measures were made by the same investigator.Results:Same day measures were repeatable within ±3.8 N by the third visit, with lesser repeatability on the 1st and 2nd visit days. Across days, repeatability was improved by Visits 2 and 3 with a coefficient of repeatability between those days of ±5.5 N. Better repeatability was obtained using averaged scores rather than ‘best effort’ ; but average scores can underestimate best effort.Conclusion:Reasonable within‐visit repeatability was found. Across‐visit repeatability is consistent with the known difficulty that women have in maximally isolating and activating their levator ani muscles. The results corroborate the repeatability results of Dumoulin et al. [2004] using a similar type of dynamometer. Neurourol. Urodynam. 26:858–863, 2007. © 2007 Wiley‐Liss, Inc.
Metaheuristics for the vehicle routing problem with loading constraints
Authors: Doerner Karl F. , Fuellerer Guenther , Hartl Richard F. , Gronalt Manfred , Iori Manuel 
Published: March 2007

AbstractWe consider a combination of the capacitated vehicle routing problem and a class of additional loading constraints involving a parallel machine scheduling problem. The work is motivated by a real‐world transportation problem occurring to a wood‐products retailer, which delivers its products to a number of customers in a specific region. We solve the problem by means of two different metaheuristics algorithms: a Tabu Search and an Ant Colony Optimization. Extensive computational results are given for both algorithms, on instances derived from the vehicle routing literature and on real‐world instances. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(4), 294–307 2007
Singular linear systems with delay: ℋ︁∞stabilization
Authors: Boukas E. K. 
Published: March 2007

AbstractThis paper deals with the class of continuous‐time singular linear systems with time‐delay in the state vector. The stabilization problem of this class of systems using a state feedback controller is tackled. New delay‐dependent sufficient conditions on ℋ︁∞stabilization are developed. A design algorithm for a memoryless state feedback controller which guarantees that the closed‐loop dynamics will be regular, impulse‐free and stable with γ‐disturbance rejection is proposed. It is shown that the addressed problem can be solved if the corresponding developed linear matrix inequalities (LMIs) with some constraints are feasible. A numerical example is employed to show the usefulness of the proposed results. Copyright © 2007 John Wiley & Sons, Ltd.
Optimal control problems for anti‐periodic quasi‐linear hemivariational inequalities
Authors: Park Jong Yeoul , Park Sun Hye 
Published: March 2007

AbstractIn this paper, we prove the existence of anti‐periodic solutions to a hyperbolic quasi‐linear hemivariational inequalities by using the Faedo–Galerkin method. Then, we investigate optimal control problems governed by the inequalities. Copyright © 2007 John Wiley & Sons, Ltd.
Genetic variation in hepatic glucose‐6‐phosphatase system genes in cases of sudden infant death syndrome
Authors: Forsyth L , Scott HM , Howatson A , Busuttil A , Hume R , Burchell A 
Published: March 2007

AbstractGenetic deficiencies of the hepatic glucose‐6‐phosphatase system, either of the enzyme (G6PC1) or of the glucose‐6‐phosphate transporter (G6PT1), result in fasting hypoglycaemia. Low hepatic G6PC1 activities were previously reported in a few term sudden infant death syndrome (SIDS) infants and assumed to be due to G6PC1 genetic deficiencies. In preterm infants, failures of postnatal activation of G6PC1 expression suggest disordered development as a novel cause of decreased G6PC1 activity in SIDS. G6PC1 and G6PT1 functional and mutational analysis was investigated in SIDS and non‐SIDS infants. G6PC1 hepatic activity was abnormally low in 98 SIDS (preterm, n = 13; term, n = 85), and non‐SIDS preterm infants (n = 35) compared to term non‐SIDS infants (n = 29) and adults (n = 9). Mean glycogen levels were elevated, except in term non‐SIDS infants. A novel G6PT1 promoter polymorphism, 259C → T was found; the − 259*T allele frequency was greater in term SIDS infants (n = 140) than in term control infants (n = 119) and preterm SIDS infants (n = 30). Heterozygous and homozygous prevalence of 259C → T was 38.6% and 7.1%, respectively, in term SIDS infants. In cell‐based expression systems, the presence of − 259T in the promoter decreased basal luciferase activity by 3.2‐fold compared to − 259C. Glucose‐6‐phosphatase latency in hepatic microsomes was elevated (indicating decreased G6PT1 function) in heterozygous and homozygous − 259T states. Delayed postnatal appearance of hepatic glucose‐6‐phosphatase in infants makes them vulnerable to hypoglycaemic episodes and this may occur in some SIDS infants. However, SIDS may be an association of more complex phenotypes in which several genes interact with multiple environmental factors. A UK‐wide DNA Biobank of samples from all infant deaths, with an accompanying epidemiological database, should be established by pathologists to allow cumulative data to be collected from multiple genetic investigations on the same large cohort of samples, with the aim of selection of the best combination of genetic markers to predict unexpected infant death. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Molecular dynamics simulations to compute diffusion coefficients of gases into polydimethylsiloxane and poly{(1,5‐ naphthalene)‐co‐[1,4‐durene‐2,2′‐bis(3,4‐dicarboxyl phenyl)hexafluoropropane diimide]}
Authors: Jawalkar Sheetal S , Aminabhavi Tejraj M 
Published: March 2007

AbstractDiffusion coefficients of N2, O2, CO2 and CH4 at 298 K in polydimethylsiloxane (PDMS) and poly{[(1,5‐naphthalene)‐co‐[1,4‐durene‐2,2′‐bis(3,4‐dicarboxyl phenyl)hexafluoropropane diimide]} (6FDA‐1,5‐NDA) polymers have been estimated using molecular dynamics (MD) simulations. Estimated diffusion coefficients in PDMS decrease systematically with increasing size of the penetrant gas molecules following the experimental observations. For 6FDA‐1,5‐NDA polymer, diffusion coefficients decrease in the same order of magnitude, but differ in their sequential order, due to varying side group interactions of the polymer with the gaseous molecules. Cohesive energy density, solubility parameter and free volume of the polymers were determined using MD simulations. Reliability and accuracy of the simulations have been tested typically with the computed values of the diffusion coefficient of O2 in PDMS polymer, which compare well with the literature data. X‐ray scattering profiles of 6FDA‐1,5‐NDA have been generated to understand the interrelationship between the morphology and diffusion coefficients. The radial distribution function was evaluated to find the contribution of atoms that are important in understanding the molecular interactions during gas diffusion in polymers. Copyright © 2007 Society of Chemical Industry
Polyelectrolyte complexes based on chitosan and poly(L‐glutamic acid)
Authors: Yin Jingbo , Dai Zhengzhan , Yan Shifeng , Cao Tian , Ma Jia , Chen Xuesi 
Published: March 2007

AbstractPolyelectrolyte complexes (PECs) were prepared by mixing aqueous solutions of chitosan (CS) and poly(L‐glutamic acid) (PLGA) at various pH. It was found that the stoichiometry of the PECs depends on pH. An investigation of the PECs using Fourier transform infrared spectroscopy proved that the formation of the complexes is due to electrostatic interaction between NH3+ groups of CS and COO− groups of PLGA. The solid PECs were characterized using wide‐angle X‐ray diffraction, which suggested that a strong interaction occurs between the two polymers at pH = 4 or 5 and relatively weak interaction at pH = 3. These results were further confirmed by thermogravimetric analysis data. Transmission electron microscopy showed that the complexes have a spherical shape. The effect of ionic strength on the size of the PECs was also studied using dynamic light scattering. It was found that the size of the PECs is dependent on pH. Copyright © 2007 Society of Chemical Industry
Proteomic characterization of copper stress response in Cannabis sativa roots
Authors: Bona Elisa , Marsano Francesco , Cavaletto Maria , Berta Graziella 
Published: March 2007

AbstractCannabis sativa is an annual herb with very high biomass and capability to absorb and accumulate heavy metals in roots and shoots; it is therefore a good candidate for phytoremediation of soils contaminated with metals. Copper is an essential micronutrient for all living organisms, it participates as an important redox component in cellular electron transport chains; but is extremely toxic to plants at high concentrations. The aim of this work was to investigate copper effects on the root proteome of C. sativa, whose genome is still unsequenced. Copper stress induced the suppression of two proteins, the down‐regulation of seven proteins, while five proteins were up‐regulated. The resulting differences in protein expression pattern were indicative of a plant adaptation to chronic stress and were directed to the reestablishment of the cellular and redox homeostasis.
A comprehensive proteome map of the lipid‐requiring nosocomial pathogen Corynebacterium jeikeium K411
Authors: Hansmeier Nicole , Chao Tzu‐Chiao , Daschkey Svenja , Müsken Mathias , Kalinowski Jörn , Pühler Alfred , Tauch Andreas 
Published: March 2007

AbstractCorynebacterium jeikeium is a lipid‐requiring pathogen that is considered as part of the normal microflora of the human skin and associated with severe nosocomial infections. Systematic reference maps of the cytoplasmic, cell surface‐associated, and extracellular proteome fractions of the clinical isolate C. jeikeium K411 were examined by 2‐DE coupled with MALDI‐TOF MS. A sum total of 555 protein spots were identified by PMF, corresponding to 358 different proteins that were classified into functional categories and integrated into metabolic pathways. The majority of the proteins were linked to housekeeping functions in energy production and translation and to physiological processes in amino acid, carbohydrate, nucleotide, and lipid metabolism. A complete enzymatic machinery necessary to utilize exogenous fatty acids by β‐oxidation was detected in the cytoplasmic proteome fraction. In addition, several predicted virulence factors of C. jeikeium K411 were identified in the cell surface‐associated and extracellular subproteome, including the cell surface proteins SurA and SurB, the surface‐anchored pilus subunits SapA and SapB, the surface‐anchored collagen adhesin CbpA, the cholesterol esterase Che, and the acid phosphatase AcpA.
New polyphenylene‐ and polyphenylenevinylene‐based copolymers containing triarylpyrazoline units in the main chains
Authors: Peng Qiang , Li Mingjun , Tang Xinghua , Lu Shiqiang , Peng Junbiao , Cao Yong 
Published: March 2007

AbstractTwo novel polyphenylene and polyphenylenevinylene copolymers containing triarylpyrazoline units in the main chains were synthesized and characterized. The resulting copolymers were amorphous and showed excellent solubility in common organic solvents, such as dichloromethane, chloroform, 1,2‐dichloroethane, chlorobenzene, toluene, and THF. The polymers possessed good thermal stability with glass transition temperatures of 82 and 96 °C and decomposition onset temperatures of 295 and 309 °C, respectively. They exhibited good photoluminescence properties with high photoluminescence efficiencies. Double‐layered light‐emitting‐diode devices with an indium tin oxide/Poly(3,4‐ethylenedioxythiophene)/polymer/Ba/Al configuration could emit strong green light with external quantum efficiencies of0.53 and 0.92%. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1632–1640, 2007
Novel tobramycin inhalation powder in cystic fibrosis subjects: Pharmacokinetics and safety
Authors: Geller David E. , Konstan Michael W. , Smith Jeffrey , Noonberg Sarah B. , Conrad Carol 
Published: March 2007

AbstractAerosolized antibiotics are associated with a high treatment burden that can result in non‐adherence to chronic therapy. We evaluated the pharmacokinetics (PK) and safety of tobramycin inhalation powder (TIP), a novel dry‐powder formulation designed to deliver a high payload of tobramycin topically to the lungs for management of chronic Pseudomonas aeruginosa infections. This was a multi‐center, open‐label, sequential‐cohort, single‐dose, dose‐escalation study using the standard 300 mg dose of tobramycin solution for inhalation (TSI) as an active control. Subjects were randomized to TIP or TSI in a 3:1 ratio in each of five cohorts. Measurements included serum and sputum tobramycin concentrations, administration time, serum chemistries, acute change in lung function, and adverse events (AEs). Out of 90 randomized subjects, 86 had data for safety analysis; and 84 had data for PK analysis. Serum tobramycin PK profiles were similar for TIP and TSI. Four capsules of 28 mg TIP (total tobramycin dose 112 mg) produced comparable systemic exposure to 300 mg TSI, in less than one‐third the administration time. The most common AEs associated with TIP were cough (20%) and dysgeusia (17%). TIP allows for faster and more efficient pulmonary delivery of tobramycin than TSI and has a safety profile that supports continued clinical investigation. The increased rate of local respiratory tract irritation noted with TIP is not unexpected with a high‐payload powder formulation. The development of dry powder inhaled antibiotics may represent an important advance in the treatment of chronic lung infections. Pediatr Pulmonol. 2007; 42:307–313. © 2007 Wiley‐Liss, Inc.