bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative cerebral perfusion using dynamic susceptibility contrast MRI: Evaluation of reproducibility and age‐ and gender‐dependence with fully automatic image postprocessing algorithm
Authors: Shin Wanyong , Horowitz Sandra , Ragin Ann , Chen Yufen , Walker Matthew , Carroll Timothy J. 
Published: October 2007

AbstractA novel approach for quantifying cerebral blood flow (CBF) is proposed that combines the bookend technique of calculating cerebral perfusion with an automatic postprocessing algorithm. The reproducibility of the quantitative CBF (qCBF) measurement in healthy controls (N = 8) showed a higher intraclass correlation coefficient (ICC) and lower coefficient of variation (COV) when calculated with automatic analysis (ICC/COV = 0.90/0.09) than when compared to conventional manual analysis (ICC/COV = 0.58/0.19). Also, the reproducibility in patients (N = 25) was successfully evaluated with the automatic analysis (ICC/COV = 0.81/0.14). In 175 consecutive clinical scans, we found 3.0% and 7.4% of qCBF decrease per decade in white matter (WM) (21.5 ± 6.66 ml/100 g‐min) and gray matter (GM) (49.6 ± 16.2 ml/100 g‐min), respectively. Cerebral blood volume (CBV) showed a significant 3.7% decrease per decade in GM (3.00 ± 0.94 ml/100 g) but not in WM (1.69 ± 0.40 ml/100 g). Mean transit time (MTT) increased by 1.9% and 3.8% per decade in WM (5.04 ± 0.88 s) and GM (4.14 ± 0.80 s), respectively. qCBF and MTT values between males (N = 85) and females (N = 90) were significantly different in GM. Women showed 11% higher qCBF as well as a higher decrease in qCBF with increasing age than men in the whole brain (WB). Our results supported the notion that population average empirical quantification of cerebral perfusion is subject to individual variation as well as age‐ and gender‐dependent variability. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Non‐Cartesian data reconstruction using GRAPPA operator gridding (GROG)
Authors: Seiberlich Nicole , Breuer Felix A. , Blaimer Martin , Barkauskas Kestutis , Jakob Peter M. , Griswold Mark A. 
Published: October 2007

AbstractA novel approach that uses the concepts of parallel imaging to grid data sampled along a non‐Cartesian trajectory using GRAPPA operator gridding (GROG) is described. GROG shifts any acquired data point to its nearest Cartesian location, thereby converting non‐Cartesian to Cartesian data. Unlike other parallel imaging methods, GROG synthesizes the net weight for a shift in any direction from a single basis set of weights along the logical k‐space directions. Given the vastly reduced size of the basis set, GROG calibration and reconstruction requires fewer operations and less calibration data than other parallel imaging methods for gridding. Instead of calculating and applying a density compensation function (DCF), GROG requires only local averaging, as the reconstructed points fall upon the Cartesian grid. Simulations are performed to demonstrate that the root mean square error (RMSE) values of images gridded with GROG are similar to those for images gridded using the gold‐standard convolution gridding. Finally, GROG is compared to the convolution gridding technique using data sampled along radial, spiral, rosette, and BLADE (a.k.a. periodically rotated overlapping parallel lines with enhanced reconstruction [PROPELLER]) trajectories. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Distance‐two interpolation for parallel algebraic multigrid
Authors: De Sterck Hans , Falgout Robert D. , Nolting Joshua W. , Yang Ulrike Meier 
Published: October 2007

AbstractAlgebraic multigrid (AMG) is one of the most efficient and scalable parallel algorithms for solving sparse linear systems on unstructured grids. However, for large 3D problems, the coarse grids that are normally used in AMG often lead to growing complexity in terms of memory use and execution time per AMG V‐cycle. Sparser coarse grids, such as those obtained by the parallel modified independent set (PMIS) coarsening algorithm, remedy this complexity growth but lead to nonscalable AMG convergence factors when traditional distance‐one interpolation methods are used. In this paper, we study the scalability of AMG methods that combine PMIS coarse grids with long‐distance interpolation methods. AMG performance and scalability are compared for previously introduced interpolation methods as well as new variants of them for a variety of relevant test problems on parallel computers. It is shown that the increased interpolation accuracy largely restores the scalability of AMG convergence factors for PMIS‐coarsened grids, and in combination with complexity reducing methods, such as interpolation truncation, one obtains a class of parallel AMG methods that enjoy excellent scalability properties on large parallel computers. Copyright © 2007 John Wiley & Sons, Ltd.
Fetal cardiac stroke volume determination by four‐dimensional ultrasound with spatio‐temporal image correlation compared with two‐dimensional and Doppler ultrasonography
Authors: Rizzo Giuseppe , Capponi Alessandra , Cavicchioni Ottavia , Vendola Marianne , Arduini Domenico 
Published: October 2007

AbstractObjectiveTo assess the agreement of stroke volume (SV) measured with two‐dimensional (2D) ultrasonography with Doppler capability (vs) four‐dimensional (4D) with spatiotemporal image correlation (STIC) in normal and growth restricted fetuses.Methods2D Doppler and 4D STIC were used to measure SV of 40 normal fetuses at 20 to 22 and 28 to 32 weeks, and 16 growth‐restricted fetuses at 26 to 34 weeks of gestation. Intraclass correlation was used to evaluate the agreement between left and right SV obtained by the two techniques, and proportionate Bland–Altman plots constructed. The time necessary to obtain SV was analyzed.ResultsThe intraclass correlation coefficient between 2D Doppler and 4D STIC measurements for the left ventricle were 0.977 and 0.980 for the right ventricle. The proportionate limits of agreement between the two methods were 18.7 to 23.9% for the left ventricle and − 20.9 to 21.7% for the right ventricle. The time necessary to measure SV was significantly shorter with 4D STIC (3.1 (vs) 7.9 min p < 0.0001) than with 2D Doppler.ConclusionsThere is a good agreement between SV measured either by 2D Doppler or by 4D STIC. The 4D STIC represents a simple and rapid technique to estimate fetal SV and promises to become the method of choice. Copyright © 2007 John Wiley & Sons, Ltd.
Maternal urine for prenatal diagnosis—an analysis of cell‐free fetal DNA in maternal urine and plasma in the third trimester
Authors: Majer Sandra , Bauer Margit , Magnet Eva , Strele Andrea , Giegerl Elisabeth , Eder Martina , Lang Uwe , Pertl Barbara 
Published: October 2007

AbstractObjectivesThe aim of the study was the detection, quantification and correlation of cell‐free fetal (cff) DNA in maternal urine and plasma in normal and complicated pregnancies during the third trimester.MethodsOne hundred and fifty‐one urine and plasma samples obtained from 96 women carrying male fetuses, and 55 carrying female fetuses were collected and analyzed for cff‐DNA using fluorescent PCR and quantitative real‐time PCR. DNA was extracted from 1 mL maternal urine and analyzed with two different primer sets (SRY and DYS‐14). The concentrations of cff and total DNA in maternal plasma were correlated with maternal and obstetric parameters using appropriate correlation analyses.ResultsY‐chromosome‐specific sequences were detected in 31 of 96 (32.3%) urine samples collected from women pregnant with male fetuses using DYS‐14 and in 6 of 96 (6.3%) urine samples using SRY as primers using real‐time PCR. All 96 plasma samples obtained from women carrying male fetuses were positive for cff‐DNA using real‐time PCR. Cff‐DNA exhibited a correlation with gestational age (R = 0.244; P = 0.018) and an inverse correlation with the latency between blood collection and birth (R = − 0.218; P = 0.036). Total DNA showed a correlation with placental weight (R = 0.182; P = 0.034) and pregnancy‐associated complications (R = 0.280; P < 0.001).ConclusionOur data confirm that cff‐DNA is cleared by the kidneys in detectable amounts, but due to its low concentration or problematic detection in maternal urine this source seems inappropriate for noninvasive prenatal diagnosis. Copyright © 2007 John Wiley & Sons, Ltd.
Controlling numbers and sizes of beads in electrospun nanofibers
Authors: Liu Yong , He Ji‐Huan , Yu Jian‐yong , Zeng Hong‐mei 
Published: October 2007

AbstractBACKGROUND: Electrospinning is a powerful and effective method to produce nanofibers. Beads have been observed widely in electrospun products, but effects of solvents, weight concentrations and salt additives on the number and morphology of beads in the electrospinning process have not been systematically studied.RESULTS: Both theoretical analysis and experimental results show that beads strongly depend upon solvents, weight concentrations and salt additives. Either a suitable weight concentration or a suitable salt additive can completely prevent the occurrence of beads in the electrospinning process; solvents can affect the number of beads and the morphology of electrospun fibers.CONCLUSION: Beads are mainly caused by lower surface tension. With a higher surface tension, the size and number of beads in electrospun products are smaller and fewer, respectively. Copyright © 2007 Society of Chemical Industry
Identification of putative serum glycoprotein biomarkers for human lung adenocarcinoma by multilectin affinity chromatography and LC‐MS/MS
Authors: Heo Sun‐Hee , Lee Seung‐Jin , Ryoo Hyun‐Mo , Park Jae‐Yong , Cho Je‐Yoel 
Published: October 2007

AbstractGlycoproteins in human serum play fundamental roles in many biological processes, and also have clinical value as biomarkers for disease progression and treatment. In this study, we isolated glycoproteins from the sera of three healthy individuals and three lung adenocarcinoma patients using multilectin affinity chromatography. The recovered glycoproteins were subjected to treatment with peptide‐N‐glycosidase F (PNGase F) and in‐gel digestion by trypsin. Tryptic peptides were analyzed by nano‐LC coupled to ESI‐MS/MS and the MS/MS spectra were processed by Bioworks 3.2 and an in‐house bioinformatics tool, ProtAn. Approximately 90% of the proteins identified contained more than one potential glycosylation site. Comparison of the serum glycoproteome of healthy and adenocarcinoma individuals revealed 38 cancer‐selective proteins. Among them, 60% have previously been reported as low abundance proteins in human sera. We identified several cancer‐selective proteins that have been previously characterized as potential indicators of lung cancer in serum or plasma, including haptoglobin (HP), inter‐α‐trypsin inhibitor heavy chain 4 (ITI‐H4), complement C3 precursor, and leucine‐rich α‐2‐glycoprotein. In addition, plasma kallikrein (KLKB1) and inter‐α‐trypsin inhibitor heavy chain 3 (ITI‐H3) were identified as being potentially elevated in the lung cancer group, and were validated by Western blot analysis. Furthermore, ∼18 kDa plasma kallirein protein fragment was detected at high levels in 25 out of 28 adenocarcinoma patients, while one of the eight normal individuals showed moderate positive. The results suggest that KLKB1 represents a potential candidate serum biomarker of lung cancer.
Cystic fibrosis in India
Authors: Kabra S.K. , Kabra M. , Lodha R. , Shastri S. 
Published: October 2007

AbstractCystic fibrosis (CF) was considered to be non‐existent in Indian subcontinent. Reports in last one decade have suggested that cystic fibrosis occurs in India but its precise magnitude is not known. Studies on migrant Indian population in United States and United Kingdom estimate frequency of CF as 1:10,000 to 1:40,000. The clinical features are similar to that reported in Caucasian population. CF in Indian children is usually diagnosed late and in advanced stage. Children are more malnourished and may have clinically evident deficiency of fat soluble vitamins. The frequency of clubbing, colonization with Pseudomonas, and laboratory evidence of pseudo‐Bartter syndrome is relatively more at the time of diagnosis. Diagnostic facilities in form of sweat chloride estimation and genetic studies are not available readily. Mutation profile is different. The frequency of common mutation F508del in Indian children is between 19% and 34%. Other mutations are heterogeneous. Management of CF in India is difficult due to less number of trained manpower, limited availability, and high cost of pharmacologic agents. The determinants of early death include: severe malnutrition and colonization with Pseudomonas at the time of diagnosis, more than four episodes of lower respiratory infection per year and age of onset of symptoms before 2 months of age. To conclude, CF does occur in India; however, precise magnitude of problem is not known. There is need to create awareness amongst pediatricians, developing diagnostic facilities, and management protocols based on locally available resources. Pediatr Pulmonol. 2007; 42:1087–1094. © 2007 Wiley‐Liss, Inc.
Partial splenectomy for portal hypertension in cystic fibrosis related liver disease
Authors: Louis Dominique , Duc Mai Linh Pham , Reix Philippe , Chazalette Jean‐Pierre , Durieu Isabelle , Feigelson Jean , Bellon Gabriel 
Published: October 2007

AbstractAimsTo review the middle‐ and long‐term effects of partial splenectomy (PS) on portal hypertension (PHT) and its complications in patients with cystic fibrosis (CF) related liver disease risky PHT.MethodOver a 20 years period, 19 patients aged 7–23 years underwent partial PS for massive splenomegaly, hypersplenism, and / or severe PHT.ResultsIn all but three cases, PHT and hypersplenism have improved for long periods. Noticeable improvement of hepatic tests occurred simultaneously. In all patients PS resolved abdominal discomfort. Fifteen patients are alive and a stabilization of the liver disease occurred with a follow‐up of 1–20 years (mean 7.9). One patient died following respiratory insufficiency 10 years after PS although PHT was stable. Manifestations recurred in 2 patients 5 and 6 years after PS. In two patients, the course of the disease evolved to hepatic insufficiency without recurrence of PHT 3 and 8 years after PS. PS did not give the expected results in three cases only, in which PHT was not modified or reoccurred during the following year. No severe complication was observed. Early (three patients) or late (one patient) eventration required surgical procedure.ConclusionsOur results show that PS is a reliable and well‐tolerated technique. Therefore, it is a therapeutic option for the management of PHT in CF patients with a preserved liver function. It can prevent and significantly delay a liver transplantation and its constraints. Pediatr Pulmonol. 2007; 42:1173–1180. © 2007 Wiley‐Liss, Inc.
Controlled‐ventilation volumetric CT scan in the evaluation of acquired pulmonary lobar emphysema: A case report
Authors: Khan Salman , Kurland Geoffrey , Newman Beverley 
Published: October 2007

AbstractAcquired lobar emphysema (ALE), a clinical entity often associated with bronchopulmonary dysplasia (BPD) in premature infants, carries significant morbidity and mortality. Because of compression of adjacent lung tissue and poor response to medical therapy, patients may require surgical resection of the hyperinflated region of lung. The decision of proceed to surgery is often problematic, relying upon standard chest radiographs, ventilation‐perfusion scans, and high resolution CT (HRCT) scans. We report the use of controlled volume HRCT with breath‐holding at TLC and FRC in an infant with severe BPD and ALE. Using reconstruction software, we could estimate total lung volume as well as the volume of the lobe affected by ALE at both lung volumes, permitting the determination of the degree of air trapping. This is turn afforded us confirmatory data of the extent of the affected lung, justifying surgical removal. Pediatr Pulmonol. 2007;42:1222–1228. © 2007 Wiley‐Liss, Inc.
Superfocusing of optical beams below the diffraction limit by media with negative refraction
Authors: Husakou A. , Herrmann J. 
Published: October 2007

AbstractUsual optical elements cannot focus a light beam to a spot with diameter smaller than half of the wavelength of the light; however overcoming this limit is of great importance in several high‐tech applications such as optical lithography, magneto‐optical data storage, and numerous other fields of science and industry. Here we show that it is possible to focus light to spots below the diffraction limit (superfocusing) by the combination of two main elements: one which creates weak near‐field evanescent components of the beam, and one which amplifies these evanescent fields, such as a slab of a photonic crystal with negative refraction. For the creation of seed evanescent components a wavelength‐scale aperture can be used. For superfocusing of scanning beams a light‐controlled saturable absorber or a nonlinear material with a Kerr‐type nonlinearity enables focusing of beams without spatial near‐field control to spots in the range of 0.2λ. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and application of functionalized photonic crystal fibres
Authors: Bartelt H. , Kirchhof J. , Kobelke J. , Schuster K. , Schwuchow A. , Mörl K. , Röpke U. , Leppert J. , Lehmann H. , Smolka S. , Barth M. , Benson O. , Taccheo S. , D'Andrea C. 
Published: October 2007

AbstractThe concept of microstructured and photonic band gap fibres opens a wide range of flexibility to introduce specific functionality in fibre light guiding properties and to adapt optical fibres to specific applications. In addition to flexible structural parameters, the use of specific material properties further increases the design freedom in optical fibres. In order to demonstrate the wide functional capabilities of such fibres, we have investigated different index guiding and photonic band gap fibres made from pure and modified silica and from non‐silica materials. The main interest in the use of different materials than the well‐known high‐purity silica is to utilize special optical properties such as high nonlinearity, specific dispersion or extended infrared transmission windows. A main challenge for such unconventional materials is to transfer the excellent properties of silica‐based photonic crystal fibres, like low spectral loss or good durability, to the modified or non‐silica materials. The preparation of modified silica‐based photonic crystal fibres was implemented by the MCVD doping process or by the use of high‐melting lanthanium or lead silicate special glasses. Highly germanium‐doped silica rods were used for the preparation of index guiding and for band gap guiding fibres. The prepared fibres were investigated in their mode propagation properties and compared to model calculations. Application examples are presented for spectral fibre sensing and for supercontinuum generation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of disordered metallic photonic crystal slabs
Authors: Nau D. , Schönhardt A. , Christ A. , Zentgraf T. , Bauer Ch. , Kuhl J. , Giessen H. 
Published: October 2007

AbstractWe give an overview about the optical properties of disordered metallic photonic crystal slabs. Different disorder models with different next‐neighbor correlations are artificially introduced into the samples, and their influence on the samples' transmission and bandstructure are examined. We found that uncorrelated disorder reduces the amplitude of spectral features and the width of the stop‐bands in the bandstructure. Correlated disorder additionally excites multiple resonances, resulting in broadened resonances and a destroyed bandstructure even at moderate disorder. Numerical results are presented that allow to fully interpret the experimental observations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Negative permeability around 630 nm in nanofabricated vertical meander metamaterials
Authors: Schweizer Heinz , Fu Liwei , Gräbeldinger Hedwig , Guo Hongcang , Liu Na , Kaiser Stefan , Giessen Harald 
Published: October 2007

AbstractWe demonstrate a new design of a 3‐dimensional meander structure that exhibits negative permeability with a broad bandwidth between 550 nm and 665 nm. The structural design allows for full coupling of the magnetic field component at all angles of incidence. We compare our structure with other metamaterial structures with respect to the series capacitance contributions of the different metamaterials. The investigation of optical metamaterials is carried out combining transmission line analysis with numerical simulations of Maxwell's equations. The analysis is demonstrated for typical split ring structures and the novel 3D meander metamaterial structures. Comparing the resulting scattering parameter spectra as well as the retrieved effective material parameters, we find that transmission line description remains valid for metamaterials at optical frequencies. We find in addition that the longitudinal capacitance is the decisive parameter to achieve negative permeability with a broad bandwidth at optical frequencies. For experimental verification we manufactured split‐ring resonator structures and meander metamaterial structures with linewidths down to 30 nm, element sizes down to 100 nm, and periods between 200 nm and 350 nm. For meander metamaterial structures a permeability value of –1 was achieved within a bandwidth of 50 nm centered at 630 nm. The largest absolute value of –4.5 was achieved at 650 nm. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations on the generation of photonic crystals using two‐photon polymerization (2PP) of inorganic–organic hybrid polymers with ultra‐short laser pulses
Authors: Houbertz R. , Declerck P. , Passinger S. , Ovsianikov A. , Serbin J. , Chichkov B. N. 
Published: October 2007

AbstractOptical devices with micro‐ and nanooptical elements using polymers and, in particular nano‐scaled organic–inorganic hybrid materials such as ORMOCER®s, will be beyond of the next generation of optical components. For the generation of photonic elements, 3D photonic bandgap materials have been proposed as the basis of many devices. In order to create complete 3D photonic bandgaps, materials enabling high refractive index contrast are needed. Combining suitable materials with highly sophisticated processing methods such as two‐photon polymerization (2PP) using femtosecond lasers is a step towards novel photonic elements. The materials and the patterning process will be discussed with respect these applications. In order to demonstrate the potential of the 2PP method, different classes of materials are investigated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of photonic/plasmonic structures in nanocomposite glass
Authors: Graener H. , Abdolvand A. , Wackerow S. , Kiriyenko O. , Hergert W. 
Published: October 2007

AbstractGlass containing metallic nanoparticles shows unique optical properties and is therefore a promising material for various photonic applications. It is demonstrated, how such material can be structured using external electric fields. The optical properties of such photonic structures are investigated. Prior to the theoretical design of photonic structures in such a glass a critical investigation of the dielectric properties is necessary. A comparison of the effective medium theory and finite element calculations is given. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)