bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gadolinium‐based contrast agents and their potential role in the pathogenesis of nephrogenic systemic fibrosis: The role of excess ligand
Authors: Sieber Martin A. , Lengsfeld Philipp , Walter Jakob , Schirmer Heiko , Frenzel Thomas , Siegmund Fred , Weinmann Hanns‐Joachim , Pietsch Hubertus 
Published: April 2008

AbstractPurposeTo investigate the role of excess ligand present in gadolinium (Gd) ‐based contrast agents in the development of nephrogenic systemic fibrosis (NSF). Using a dosing regimen to simulate the exposure seen in patients with severe renal impairment, we investigated the effect of excess ligand on Gd‐deposition and the depletion of endogenous ions.Materials and MethodsGadodiamide and gadoversetamide were formulated with 0%, 5%, and 10% excess ligand. Forty‐two, healthy, male Hannover Wistar rats received daily intravenous injections of each formulation over a period of 20 days. At the end of the study, histopathological analysis of the skin was performed and the concentrations of Gd, Zn, and Cu were measured in several tissues. The levels of Zn in the urine were also measured.ResultsThe most severe skin lesions were observed after injection of formulations containing 0% free ligand and in those animals with the highest Gd concentrations in the skin. There were no significant reductions in the levels of Zn or Cu observed in the skin; however, the levels of Zn in the urine were elevated following administration of formulations with the highest amount of excess ligand.ConclusionOur findings suggest that there is an inverse correlation between the amount of excess ligand present in Gd‐containing contrast agents and the amount of Gd in the tissue, and further underline the importance of the inherent stability of these agents in the development of NSF. J. Magn. Reson. Imaging 2008;27:955–962. © 2008 Wiley‐Liss, Inc.
Local fuel concentration measurements for mixture formation diagnostics using diffraction by laser‐induced gratings in comparison to spontaneous Raman scattering
Authors: Kiefer J. , Kozlov D. N. , Seeger T. , Leipertz A. 
Published: April 2008

AbstractThe potential of the laser‐induced gratings (LIGs) technique for the determination of fuel concentrations is investigated in comparison to the well‐established spontaneous Raman scattering (SRS) technique. At pulse‐repetitive excitation, the temporal shape of the LIG signals, containing non‐resonant electrostrictive and resonant thermal contributions, as well as the Raman spectra were recorded in single‐shot and accumulation modes. The measurements were performed in a laboratory system: in mixtures of propane as a fuel with nitrogen and air under stationary conditions in order to provide calibration data and to investigate the single‐shot precision of measurements; and in the course of pulsed injection of gaseous propane into air at elevated pressures and temperatures. In the latter case, parameters of the experiment such as temperature, amount of injected gas and pressure were adjusted to be close to conditions of practical interest existing in real engines with direct injection (DI). The temporal variation of local propane concentration was tracked after the start of the injection pulse. Various approaches to the fast evaluation of the temporal shape of the measured LIG signals were tested, and their applicability in different ranges of propane concentrations, as well as single‐shot measurement precision, were investigated. The results of employing the LIG technique were compared to those provided by the evaluation of the ratio of the integrated line intensities in the recorded SRS spectra. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of pressure toasting on in situ degradability and intestinal protein and protein‐free organic matter digestibility of rapeseed
Authors: Azarfar Arash , Ferreira Claudio S , Goelema Jacob O , Van der Poel Antonius FB 
Published: April 2008

AbstractBACKGROUND: Rapeseed is a protein supplement that contains up to 40% crude protein (CP) on a dry matter (DM) basis, but a large part of its protein can be easily degraded in the rumen. Therefore, before inclusion in ruminant's diet, the extent of its protein degradation in the rumen must be reduced without altering its intestinal digestibility. A study was conducted to investigate the effects of pressure toasting (T, 130 °C) at two residence times (1.5 and 10 min) alone or in combination with soaking in water (ST, 4 h) on ruminal degradability and intestinal digestibility of CP and protein‐free organic matter (PFOM) in whole full‐fat rapeseed.RESULTS: Regardless of the processing time (1.5 or 10 min), T significantly (P < 0.05) increased the fraction of undegraded intake protein (UIP) compared to the untreated rapeseed samples. Soaking prior to further toasting did not improve the rumen degradation characteristics of rapeseed CP. Compared to the untreated rapeseed samples, both T and ST significantly (P < 0.0001) improved the true protein digested in the small intestine (DVE) and degraded protein balance (OEB), effects that were more evident in samples heated for 10 min. Soaking prior to pressure toasting, however, did not further improve the DVE or OEB in the rapeseed samples in comparison with T treatment.CONCLUSIONS: It was concluded that ruminal protein degradability of rapeseed decreased after pressure toasting, without seriously affecting its intestinal digestibility. Copyright © 2008 Society of Chemical Industry
Application of surface response methodology to optimize hydrolysis of wheat gluten and characterization of selected hydrolysate fractions
Authors: Drago Silvina R , González Rolando J , Añón María C 
Published: April 2008

AbstractBACKGROUND: The aim of this work was to optimize the hydrolysis experimental conditions to obtain wheat gluten hydrolysates and to characterize fractions from hydrolysates with different hydrolysis degrees in order to develop protein functional ingredients. Surface response methodology was used to analyze the effect of reaction factors on the degree of hydrolysis to assess the conditions for maximum fungal protease enzyme activity. Hydrolysates having three different trichloroacetic acid indices (TCAI) were prepared. Soluble fractions at pH 4, 6.5 and 9 from these hydrolysates were characterized by electrophoresis, reverse‐phase high‐performance liquid chromatography, free amino group content and peptide chain length.RESULTS: Temperature and pH ranges for highest enzyme activity at 2.5 h were 54–58 °C and 4.2–4.4, respectively. Hydrolysate fraction composition differs according to the hydrolysis degree and extracting pH, the difference being more pronounced at low TCAI. Hydrolysate having 32% TCAI is composed of peptides whose size is lower than 18.5 kDa, with an average peptide chain length of 14 amino acid residues.CONCLUSION: The combination of hydrolysis degree and pH of extraction allows fractions of different peptide composition to be obtained, which could be taken into account when trying to find a defined composition related to determined functional characteristics. Copyright © 2008 Society of Chemical Industry
Impact of type of liver resection on the outcome of colorectal liver metastases: A case‐matched analysis
Authors: Guzzetti Eleonora , Pulitanò Carlo , Catena Marco , Arru Marcella , Ratti Francesca , Finazzi Renato , Aldrighetti Luca , Ferla Gianfranco 
Published: April 2008

AbstractBackgroundWedge resection (WR) for colorectal liver metastases (CLM) has become more common in an attempt to preserve liver parenchyma. However, some investigator have reported that WR is associated with a higher incidence of positive margin and an inferior survival compared with anatomic resection (AR) 1.ObjectivesThis study evaluated survival, margin status, and pattern of recurrence of patients with CLM treated with WR or AR.MethodsWe identified 208 consecutive patients, in a single institutional database from 1995 to 2004, who underwent either WR or AR. WR was defined as a nonanatomic resection and AR was defined as single resection of one or two liver segments. Patients with combined WR–AR and patients requiring resection of more than two segments or radiofrequency ablation were excluded from the analysis.ResultsOne hundred six patients underwent WR and 102 patients had AR. There were no differences in the rate of positive surgical margin (P = 0.146), overall recurrence rates (P = 0.211), and patterns of recurrence between the two groups (P = 0.468). The median survival was 32 months for WR and 42 for AR, with 5‐year survival rates of 29% and 27% respectively, with no significant difference (P = 0.308). Morbidity was similar between the two groups.ConclusionsWR is a safe procedure and does not disadvantage the patients in terms of tumor recurrence and overall survival. J. Surg. Oncol. 2008;97:503–507. © 2008 Wiley‐Liss, Inc.
A fast elastostatic solver based on fast Fourier transform on multipoles (FFTM)
Authors: He Xuefei , Lim Kian Meng , Lim Siak Piang 
Published: April 2008

AbstractIn this paper, we present a fast algorithm to solve elasticity problems, governed by the Navier equation, using the boundary element method (BEM). This fast algorithm is based on the fast Fourier transform on multipoles (FFTM) method that has been developed for the Laplace equation. The FFTM method uses multipole moments and their kernel functions, together with the fast Fourier transform (FFT), to accelerate the far field computation. The memory requirement of the original FFTM tends to be high, especially when the method is extended to the Navier equation that involves vector quantities. In this paper, we used a compact representation of the translation matrices for the Navier equation based on solid harmonics. This reduces the memory usage significantly, allowing large elasticity problems to be solved efficiently. The improved FFTM is compared with the commonly used FMM, revealing that the FFTM requires shorter computational time but more memory than the FMM to achieve comparable accuracy. Finally, the method is applied to calculate the effective Young's modulus of a material containing numerous voids of various shapes, sizes and orientations. Copyright © 2008 John Wiley & Sons, Ltd.
Strength of short fiber reinforced polymers: Effect of fiber length distribution
Authors: Aykol Muratahan , Isitman Nihat Ali , Firlar Emre , Kaynak Cevdet 
Published: April 2008

AbstractIn this study, the prediction of mechanical strength of short fiber reinforced plastics (SFRPs) is made possible by obtaining a Fiber Length Distribution (FLD) efficiency factor, ηFLD, from the formerly known twofold discrete strengthening equation of Kelly–Tyson. The unified parameter ηFLD is developed involving both the effects of fiber breakage and resulting distribution, fiber volume fraction and fiber and interface properties, so that they can be incorporated into modified rule of mixtures (MROM). This procedure helps to clarify the experimentally observed loss in strengthening rate with increasing fiber fraction. By adapting a few experimentally determined distributions to a Weibull type function, the analytical solutions described in this study establish the exploration of the strength of SFRPs in the entire fiber content range or can reveal the interfacial bond strength. After investigating the effects of fiber and interface parameters on strengthening efficiency, it is found that common fiber‐matrix combinations possessing intermediate critical fiber lengths show a significant decrease in strengthening efficiency with increasing fiber content at low fiber loadings. On the contrary, higher and lower critical fiber lengths yield less significant losses. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Conservative management of emphysematous pyelonephritis in type 1 diabetes
Authors: Mckenna C , Ripley D , Pearson A , Leslie PJ 
Published: April 2008

AbstractEmphysematous pyelonephritis (EPN) is a rare but life threatening infection of the renal parenchyma, which is strongly associated with diabetes. Here we present a case of class 3B EPN that highlights the characteristic radiological findings as well as the successful use of conservative treatment. Copyright © 2008 John Wiley & Sons.
Prevalence and characteristics of anaemia in diabetes
Authors: Adetunji OR , Mani H , Olujohungbe A , Ronald J , Morgan C , Gill Gv 
Published: April 2008

AbstractThere are an increasing number of patients with diabetes who have been found to be anaemic without underlying evidence of chronic renal disease. The cause of this anaemia is mainly unknown. This study set out to determine the prevalence and characteristics of anaemia in our local diabetes population.Five hundred and thirty‐one patients attending the diabetes outpatient department were consecutively screened for anaemia with a full blood count after written informed consent was taken. Anaemia was defined by World Health Organization criteria (<13g/dl for men, and <12g/dl for women). The urinary albumin–creatinine ratio, serum creatinine and estimated glomerular filtration rate were determined.Of the 531 screened, anaemia was present in 134 (25%) patients. Only 26 (19%) of those with anaemia had previously known nephropathy and 16 (12%) had microcytic anaemia. The majority of the anaemic population were previously undetected with no obvious cause for the anaemia.Anaemia was common in the study population. Screening routinely for anaemia at annual diabetes follow‐up clinics may be a cheap and effective way of identifying patients at risk of impaired quality of life and increased cardiovascular risk. Copyright © 2008 John Wiley & Sons.
Comparative proteomic analysis of mouse livers from embryo to adult reveals an association with progression of hepatocellular carcinoma
Authors: Lee Nikki P. Y. , Leung Kar‐wai , Cheung Nicole , Lam Brian Y. , Xu Michelle Z. , Sham Pak C. , Lau George K. , Poon Ronnie T. P. , Fan Sheung Tat , Luk John M. 
Published: April 2008

AbstractTo identify potential oncofetal biomarkers that distinguish hepatocellular carcinoma (HCC) from healthy liver tissues, we compared and analyzed the proteomic profiles of mouse livers at different developmental stages. Fetal (E13.5, E16.5), newborn (NB), postnatal (3‐week) and adult (3‐month) livers were isolated and profiled by 2‐D PAGE. Statistical analysis using linear regression and false discovery rate (FDR) revealed that 361 protein spots showed significant changes. Unsupervised hierarchical tree analysis segregated the proteins into fetal, NB, and postnatal‐adult clusters. Distinctive protein markers were identified by MALDI‐TOF/MS and the corresponding mRNA profiles were further determined by Q‐PCR. Fetal markers (hPCNA, hHSP7C, hHEM6) and postnatal‐adult markers (hARGI1, hASSY, hBHMT, hFABPL) were selected for testing against a panel of seven human hepatocyte/HCC cell lines and 59 clinical specimens. The fetal proteins were found to be overexpressed in the metastatic HCC cell lines and the tumor tissues, whereas the postnatal‐adult proteins were expressed in non‐tumor tissues and normal hepatocytes. This “Ying‐Yang” pattern, as orchestrated by distinct fetal and adult markers, is hypothesized to indicate the progressive change of the liver from a growing, less‐differentiated organ into a functional metabolic center. Thus, embryogenesis and tumorigenesis share certain oncofetal markers and adult “hepatic” phenotypes are lost in HCC.
Low frequency noise in Co/Al2O3〈Si〉/Py magnetic tunnel junctions
Authors: Guerrero R. , Aliev F. G. , Villar R. , Santos T. , Moodera J. 
Published: April 2008

AbstractLow frequency noise and dynamic tunneling resistance have been studied in Co(80 Å)/Al2O3(12 Å)/Py(100 Å) magnetic tunnel junctions (MTJs) with and without asymmetric Si doping of the insulating barrier (Si ≤ 1.8 Å). Variation of the dynamic resistance and tunneling resistance with Si doping and applied bias in these MTJs indicate a transition from the Si‐doped regime to Si cluster formation above a δ ‐layer thickness of about 1.2 Å, close to 1 monolayer coverage. The measurements show anomalously strong enhancements of the low frequency noise for Si thickness above 1.2 Å, mainly due to the appearance of random telegraph noise. A simple model, which considers suppression of Coulomb blockade in the array of Si dots, opening two‐step tunnel channels, qualitatively explains the variation of both conductivity and noise with Si content. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
XMCD studies of Cox Pt100–x nanoparticles prepared by vapour deposition and chemical synthesis
Authors: Imperia P. , Glaser L. , Martins M. , Andreazza P. , Penuelas J. , Alessandrovic V. , Weller H. , Andreazza‐Vignolle C. , Wurth W. 
Published: April 2008

AbstractAn almost linear relation between the Pt amount and the orbital to spin moment ratio (μl/μs) has been found in Cox Pt100–x nanoparticles prepared by vapour deposition and possessing a well defined chemically disordered crystallographic structure. X‐ray magnetic circular dichroism (XMCD) measurements done at the L2,3Co edges show that a 4.0 nm, x = 100 Co reference sample has a ratio μl/μs = 0.097, comparable to values found for Co thin layers. An increase of the amount of Pt increases the μl/μs value: μl/μs = 0.11 for x = 78, μl/μs = 0.12 when x = 74 and finally, for x = 38 it becomes μl/μs = 0.140. Nanoparticles prepared by chemical synthesis with size proportional to changes of the stoichiometric ratio, from Co25Pt75 to Co50Pt50, show values of the orbital to spin moment ratio compatible with the trend found for the former ones. The samples prepared by chemical synthesis in a diameter range from 4 nm to 8 nm are characterized by a sharp size distribution of 10%. In contrast to the in situ prepared nanoparticles that are oxide free, however, they show a varying degree of surface oxidation depending on the ambient conditions they are exposed to. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MBE growth of AlN/GaN‐based photovoltaic intersubband photodetectors
Authors: Monroy E. , Guillot F. , Baumann E. , Giorgetta F. R. , Hofstetter D. 
Published: April 2008

AbstractWe report on the molecular‐beam epitaxial growth, fabrication and characterization of AlN/GaN photovoltaic quantum well infrared photodetectors operating at 1.55 µm. Devices display a spectrally‐narrow photovoltaic response to p‐polarized light in the near infrared at room temperature. We have analysed the effect of the growth temperature, quantum well thickness, and number of periods in the active region, concluding that responsivity is enhanced by growing at relatively low temperature and by increasing the number of quantum wells. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low noise characteristics of AlGaInN‐based self‐pulsating laser diodes
Authors: Obata T. , Kitajima N. , Ohta M. , Ichinokura H. , Kuramoto M. 
Published: April 2008

AbstractWe have successfully realized practical self‐pulsating laser diodes (SP‐LDs) based on AlGaInN systems that exhibit low noise characteristics even with an optical feedback of 1% at a high temperature of 75 °C. Our fabricated SP‐LD employs a saturable absorber layer (SAL). We adopt new approaches to realize practical SP operation; specifically, (i) we inserted an AlGaN layer between the active layer and the SAL in order to reduce the threshold current, and (ii) we intentionally introduced reactive ion etching (RIE) damage to the SAL in order to reduce the carrier lifetime in the SAL by controlling the distance between the SAL and the dry‐etched surface. The threshold currents for the fabricated SP‐LD at 25 °C and 75 °C were 38.8 mA and 54.4 mA, respectively. We also demonstrated that it is possible to suppress the relative intensity noise (RIN < –125 dB/Hz) even under the conditions of high temperature (75 °C) and an optical feedback of 1%. These results indicate that practical SP‐LDs for use in optical storage devices can be realized by inducing dry etching damage in the SAL. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum dots excited InGaN/GaN phosphor‐free white LEDs
Authors: Chua S. J. , Soh C. B. , Liu W. , Teng J. H. , Ang S. S. , Teo S. L. 
Published: April 2008

AbstractCommercial GaN based white LEDs have been fabricated using phosphor coating of blue LEDs. We report on the growth of InGaN/GaN based white LEDs using In‐rich InGaN quantum dots incorporated in the MQW layers. The photoluminescence spectrum of the MQWs shows a broad emission spectrum covering 400 to 700 nm. Cross‐section TEM shows the existence of pyramidal shaped quantum‐like structures with size of 1.5‐2.0 nm embedded in the InGaN well. To prevent the out‐diffusion of these InGaN quantum dots in the well layer during thermal activation of p‐GaN, a small amount of Indium was introduced into the p‐GaN and the temperature was kept below 800 °C for p‐InGaN epilayer growth. I‐V measurement of the white LEDs gives a forward voltage of 5.2 V for a current of IF ∼20mA. The chromaticity coordinate ranges from 0.28 < x,y < 0.34 with a colour temperature of ∼6000 K. The internal quantum efficiency was separately determined to be in excess of 50%. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates
Authors: Ive T. , Ben‐Yaacov T. , Asamizu H. , Van de Walle C. G. , Mishra U. , DenBaars S. P. , Speck J. S. 
Published: April 2008

AbstractWe studied the properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates. A two‐step growth procedure was used where a buffer layer was first deposited at 400 °C before the temperature was increased to 900 °C for the deposition of the epitaxial layer. Atomic force microscopy revealed locally straight steps on a 20 × 20 mm2 scan area. This indicates a step‐flow growth mode. The root‐mean‐square roughness was 2.6 nm. The surface exhibited hexagonal pits. The pit density was 7.5 × 105–2.1 × 108 cm–2. The full width at half maximums of w‐scans for the symmetric (0002) and the skew‐symmetric (20$ \bar 2 $1) reflections were 0.091° and 0.159°, respectively. The ZnO films were fully relaxed as revealed by reciprocal space maps for the (10$ \bar 1 $5) reflection. Gallium doped n‐type ZnO layers were deposited on (In,Ga)N light emitting diodes as transparent contacts. The electron concentration was 9.4 × 1019 cm–3 and the sheet resistance 45 W/sq. The resistivity and the mobility was 1.5 × 10–3 Wcm and 43 cm2/(Vs), respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of deep level incorporation in ammonia and rf‐plasma assisted molecular beam epitaxy n‐GaN films
Authors: Arehart A. R. , Corrion A. , Poblenz C. , Speck J. S. , Mishra U. K. , DenBaars S. P. , Ringel S. A. 
Published: April 2008

AbstractThe use of rf‐plasma and ammonia nitrogen sources for growth of GaN films by molecular beam epitaxy (MBE) are compared in terms of defect incorporation using deep level optical spectroscopy (DLOS) and deep level transient spectroscopy (DLTS). To better improve the understanding of ammonia‐based MBE growth of GaN and potential defect sources as opposed to the more studied plasma source‐based MBE‐grown material several V/III ratios were also investigated, which were generated via systematic adjustment of the ammonia flow rates during growth. The DLOS spectra, comparing deep traps within the n‐GaN grown using N‐plasma and ammonia sources, reveal the presence of the same deep levels due to background carbon and gallium vacancies, with energy levels at EC‐3.28, EC‐2.62, and EC‐1.28. The DLTS results of the N‐plasma and ammonia‐based MBE samples show two similarly dominant electron traps at EC‐0.60, and EC‐0.24 in each sample. Measurements made as a function of V/III flux ratio for ammonia‐based MBE growth indicate a large dependence of the EC‐0.24 eV trap concentration on growth flux ratio, which is significant for guiding continued optimization of this promising MBE growth method for GaN devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)