bluuebunny/crossref_metadata_2025 huggingface dataset:
T2‐weighted cardiovascular magnetic resonance imaging
Authors: Abdel‐Aty Hassan , Simonetti Orlando , Friedrich Matthias G.
Published: August 2007

Technical advances in T2‐weighted cardiovascular MR (CMR) imaging allow for accurate identification and quantification of tissue injuries that alter myocardial T2 relaxation. Of these, myocardial edema is of special relevance. Increased myocardial water content is an important feature of ischemic as well as nonischemic cardiomyopathies, which are often associated with acute myocardial inflammation. In this article, we review technical considerations and discuss clinical indications of myocardial T2‐weighted imaging. J. Magn. Reson. Imaging 2007;26:452–459. © 2007 Wiley‐Liss, Inc.
Two‐dimensional fast imaging employing steady‐state acquisition (FIESTA) cine acquisition of fetal non–central nervous system abnormalities
Authors: Shen Shu‐Huei , Guo Wan‐Yuo , Hung Jeng‐Hsiu
Published: August 2007

Purpose

To evaluate the value of two‐dimensional fast imaging employing steady‐state acquisition (2D FIESTA) cine MR with parallel imaging techniques in the diagnosis of fetal non–central nervous system (CNS) anomalies.

Materials and Methods

A total of 28 pregnant women were referred for further MR evaluation on fetuses after abnormal sonographic results. A total of 33 fetal MR examinations were performed by a 1.5T MR scanner with eight‐channel phase‐arrayed body coils. Single‐shot fast spin‐echo (SSFSE®, GE) of three orthogonal planes and 2D FIESTA for cine fetal MR of three sagittal planes (midsagittal and 10 mm off midline on left and right) were routinely acquired. Additional planes on target organs with variable imaging frames were added if indicated.

Results

Nine of the 33 examinations (9/33; 27.3%) had motion artifacts obscuring the detail in SSFSE imaging; 2D FIESTA imaging provided motion‐artifact‐free imaging in all of them. Cine 2D FIESTA imaging provided additional information on the visceral peristalsis. The information helped in differentiating dilated gastrointestinal (GI) tract from other intraabdominal cystic lesions and in confirming the nature and level of GI tract obstruction.

Conclusion

With sub‐half‐second temporal resolution of the 2D FIESTA sequences, fetal movement is no longer problematic. In addition to the anatomical information also provided by conventional SSFSE sequences, 2D FIESTA demonstrates information on motility and peristalsis of hollow organs and helps the diagnosis of fetal visceral anomalies. J. Magn. Reson. Imaging 2007;26:672–677. © 2007 Wiley‐Liss, Inc.
Physiological changes of the human uterine myometrium during menstrual cycle: Preliminary evaluation using BOLD MR imaging
Authors: Kido Aki , Koyama Takashi , Kataoka Masako , Yamamoto Akira , Saga Tsuneo , Turner Robert , Togashi Kaori
Published: August 2007

Purpose

To investigate the T2* values within the junctional zone and outer uterine myometrium and their changes during the menstrual cycle, and thus to evaluate their physiologic changes on blood oxygenation level‐dependent (BOLD) magnetic resonance (MR) imaging.

Materials and Methods

Single‐shot echo‐planar imaging (EPI) was used to acquire T2*‐weighted images (TR/TE = 1000 msec/23–150 msec) from 15 healthy females with a 1.5‐T magnet. T2* values of both junctional zone and outer uterine myometrium were measured within a single breathhold and during three menstrual cycle phases (menstrual, periovulatory, and luteal phase). Signal intensities of uterine myometrium on T2‐weighted images were also evaluated.

Results

T2* could successfully be calculated in 13 subjects. T2* values for the junctional zone were significantly lower than those of the outer myometrium at every phase(P < 0.001), and T2* values of both junctional zone (P < 0.05) and outer (P < 0.01). Myometrium in the menstrual phase was significantly lower than those in the other phases. On T2‐weighted images, the signal intensity of the junctional zone was significantly lower than outer myometrium in every phase (P < 0.01), but there was no significant difference among menstrual cycle phases in both layers (P > 0.05).

Conclusion

This preliminary study suggested that menstrual cycle changes of the uterine myometrium were shown by BOLD imaging. BOLD MR imaging may be an potential modality to investigate physiologic changes of the uterine myometrium during the menstrual cycle. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Manganese dipyridoxyl‐diphosphate (MnDPDP) as a viability marker in patients with myocardial infarction
Authors: Skjold Arne , Amundsen Brage H. , Wiseth Rune , Støylen Asbjørn , Haraldseth Olav , Larsson Henrik B.W. , Jynge Per
Published: August 2007

Purpose

To evaluate contrast accumulation in left ventricular (LV) myocardium after manganese dipyridoxyl‐diphosphate (MnDPDP) administration in patients with recent first time myocardial infarction.

Materials and Methods

MnDPDP (5 μmol/kg) was administered to 10 patients with recent myocardial infarction (three to 12 weeks). One slice of interest (SOI) likely to traverse the infarction was chosen, and sectorial pre‐ and postcontrast longitudinal relaxivity rates (R1) and signal changes during infusion were estimated with a fast gradient echo sequence. LV volume and wall thickening were measured in short‐axis cine recordings. Infarct localization from R1 and wall thickening data were compared by vector analyses.

Results

Reduced wall thickening was associated with reduced precontrast R1 and reduced contrast enhancement. Both remote and infarcted regions showed rapid initial contrast accumulation. In remote regions, this was followed by a continuing slow increase. Mean precontrast R1 was 0.87 ± 0.06 second–1 in infarcted regions and 0.96 ± 0.03 second–1 in remote regions (P < 0.001). Mean R1 change over one hour was 0.24 ± 0.07 second–1 in infarcted regions and 0.38 ± 0.03 second–1 in remote regions (P < 0.0001).

Conclusion

Remote regions showed larger increases in R1 than infarcted regions. This is most likely due to selective and slow Mn accumulation in viable myocytes. J. Magn. Reson. Imaging 2007;26:720–727. © 2007 Wiley‐Liss, Inc.
Transperineal prostate biopsy under magnetic resonance image guidance: A needle placement accuracy study
Authors: Blumenfeld Philip , Hata Nobuhiko , DiMaio Simon , Zou Kelly , Haker Steven , Fichtinger Gabor , Tempany Clare M.C.
Published: August 2007

Purpose

To quantify needle placement accuracy of magnetic resonance image (MRI)‐guided core needle biopsy of the prostate.

Materials and Methods

A total of 10 biopsies were performed with 18‐gauge (G) core biopsy needle via a percutaneous transperineal approach. Needle placement error was assessed by comparing the coordinates of preplanned targets with the needle tip measured from the intraprocedural coherent gradient echo images. The source of these errors was subsequently investigated by measuring displacement caused by needle deflection and needle susceptibility artifact shift in controlled phantom studies. Needle placement error due to misalignment of the needle template guide was also evaluated.

Results

The mean and standard deviation (SD) of errors in targeted biopsies was 6.5 ± 3.5 mm. Phantom experiments showed significant placement error due to needle deflection with a needle with an asymmetrically beveled tip (3.2–8.7 mm depending on tissue type) but significantly smaller error with a symmetrical bevel (0.6–1.1 mm). Needle susceptibility artifacts observed a shift of 1.6 ± 0.4 mm from the true needle axis. Misalignment of the needle template guide contributed an error of 1.5 ± 0.3 mm.

Conclusion

Needle placement error was clinically significant in MRI‐guided biopsy for diagnosis of prostate cancer. Needle placement error due to needle deflection was the most significant cause of error, especially for needles with an asymmetrical bevel. J. Magn. Reson. Imaging 2007;26:688–694. © 2007 Wiley‐Liss, Inc.
Thigh muscle stiffness assessed with magnetic resonance elastography in hyperthyroid patients before and after medical treatment
Authors: Bensamoun Sabine F. , Ringleb Stacie I. , Chen Qingshan , Ehman Richard L. , An Kai‐Nan , Brennan Michael
Published: August 2007

Purpose

To measure the stiffness of the vastus medialis (VM) in hyperthyroid patients before and after treatment.

Materials and Methods

A total of five healthy euthyroid patients and five hyperthyroid patients were tested using magnetic resonance elastography (MRE), which involves the induction of shear waves in the thigh muscles using a pneumatic driver at 90 Hz.

Results

Among the pretreatment hyperthyroid cohort a lower stiffness was found when the muscle was relaxed (2.11 ± 0.61 kPa) compared the stiffness following treatment of hyperthyroidism (5.52 ± 1.52 kPa), which was accompanied by an improvement in the contractile function of the VM. Pretreatment muscle stiffness was also less than that of age matched healthy volunteers (4.56 ± 0.40 kPa). The behavior of the waves was sensitive to the stage of this myopathy and to the amount of free thyroxine (FT4).

Conclusion

The MRE technique provides a new tool to gain new insights into pathophysiology of thyroid associated and other muscle diseases and their response to treatment. J. Magn. Reson. Imaging 2007;26:708–713. © 2007 Wiley‐Liss, Inc.
Application of voxelwise analysis in the detection of regions of reduced fractional anisotropy in multiple sclerosis patients
Authors: Patel Sunil A. , Hum Barbara A. , Gonzalez Carlos F. , Schwartzman Robert J. , Faro Scott H. , Mohamed Feroze B.
Published: August 2007

Purpose

To investigate the utility of voxelwise analysis in the detection of lesions in the normal appearing white matter (NAWM) of individual multiple sclerosis (MS) patients.

Materials and Methods

Diffusion tensor imaging (DTI) was performed on 10 normal controls and six patients with MS lesions. The fractional anisotropy (FA) maps derived from the diffusion‐weighted images were then spatially normalized (via an affine transformation) into Montreal Neurological Institute (MNI) space, and the normalized FA map of each of the patients was compared voxelwise with the normalized FA maps of the group of normals in a one‐sample t‐test (P = 0.0001). Two independent board‐certified neuroradiologists reviewed the data.

Results

In the patient data for all six cases, the two reviewers determined detection sensitivities of 72% and 96% for the voxelwise technique based on known fluid‐attenuated inversion‐recovery (FLAIR) lesions. In addition, between the two reviewers, nine NAWM regions exhibiting FA reductions were identified in the six patients. However, numerous regions of abnormal FA were detected that were attributed to poor intersubject image registration.

Conclusion

Voxelwise analysis of spatially normalized FA maps has the potential to identify regions of FA reduction in lesions and in the NAWM of individual MS patients in a rapid and reproducible fashion. J. Magn. Reson. Imaging 2007;26:552–556. © 2007 Wiley‐Liss, Inc.
Improved bulk myocardial motion suppression for navigator‐gated coronary magnetic resonance imaging
Authors: Jahnke Cosima , Nehrke Kay , Paetsch Ingo , Schnackenburg Bernhard , Gebker Rolf , Fleck Eckart , Nagel Eike
Published: August 2007

Purpose

To evaluate the impact of a new, cross‐correlation based method for compensation of respiratory induced motion of the heart using an individually adapted three‐dimensional (3D) translation or affine transformation approach.

Materials and Methods

A total of 32 patients underwent a routine cardiac MR examination. In each patient, a calibration scan was performed during free‐breathing to register breathing‐related motion within a 3D ellipsoid registration kernel covering the entire heart. Three navigators were employed for all three spatial dimensions (feet‐head, anterior‐posterior, and left‐right) and the optimal translatory correction factors for each spatial dimension were determined. In addition, the cross‐correlations for different motion models (no compensation, fixed 1D‐translation, adapted 3D‐translation, and affine transformation) were calculated.

Results

The mean correction factor for the feet‐head direction was 0.45 ± 0.13. Though the mean correction factors for the anterior‐posterior and left‐right direction were nearly zero (–0.01 ± 0.08 and 0.02 ± 0.09, respectively), the correction factors exceeded the amount of 0.1 in 12 (19%) and in 19 patients (30%), respectively. All motion compensation models showed significantly higher cross‐correlations when compared to “no compensation” (P < 0.05). In particular, the affine transformation algorithm achieved the highest cross‐correlation values (88.3 ± 5.1%) with a significant increase compared to fixed 1D translation (84.7 ± 6.5%, P < 0.05).

Conclusion

A considerable number of patients demonstrated relevant breathing‐related movement of the heart in the anterior‐posterior or left‐right direction in addition to the predominant breathing‐related movement in the feet‐head direction. Thus, it is recommended to compensate for all three spatial dimensions. The affine transformation algorithm combined with three navigators significantly improved breathing‐related cardiac motion compensation when compared to the conventionally applied 1D translation with a fixed correction factor. J. Magn. Reson. Imaging 2007;26:780–786. © 2007 Wiley‐Liss, Inc.
Reproducibility of wall shear stress assessment with the paraboloid method in the internal carotid artery with velocity encoded MRI in healthy young individuals
Authors: Box Frieke M.A. , van der Geest Rob J. , van der Grond Jeroen , van Osch Matthias J.P. , Zwinderman Aeilko H. , Palm‐Meinders Inge H. , Doornbos Joost , Blauw Gerard‐Jan , van Buchem Mark A. , Reiber Johan H.C.
Published: August 2007

Purpose

To verify whether wall shear stress (WSS) can be assessed in a reproducible manner using automatic model‐based segmentation of phase‐contrast MR images by determination of flow volume and maximum flow velocity (Vmax) in cross‐sections of these vessels.

Materials and Methods

The approach is based on fitting a 3D paraboloid to the actual velocity profiles and on determining Vmax. WSS was measured in the internal carotid arteries of two groups of healthy young volunteers. The reproducibility of rescanning and repositioning was studied in the first group. In the second group a 1‐week and a 1‐month interval was investigated. Reproducibility was calculated by the intraclass correlation (ICC).

Results

The flow volume, Vmax, and WSS averaged over the cardiac cycle were found to be 287.8 ± 29.7 mL/min, 37.0 ± 4.6 cm/s, and 1.13 ± 0.16 Pa, respectively. The diastolic WSS varied between 1.00 ± 0.21 Pa without averaging to 0.88 ± 0.16 Pa with temporal and spatial averaging. Systolic WSS was 1.67 ± 0.33 Pa without averaging and 1.67 ± 0.25 Pa with averaging. ICC varied between 0.58 and 0.87 without averaging and between 0.75 and 0.90 with averaging for WSS.

Conclusion

WSS in MR images of the internal carotid artery can be assessed semiautomatically with good to excellent reproducibility without inter‐ or intraobserver variability using model‐based postprocessing. J. Magn. Reson. Imaging 2007;26:598–605. © 2007 Wiley‐Liss, Inc.
Negative electrospray ionization tandem mass spectrometric investigation of ent‐kaurane diterpenoids from the genus Isodon
Authors: Zhou Yan , Huang Sheng‐Xiong , Li Li‐Mei , Yang Jing , Liu Xin , Peng Shu‐Lin , Ding Li‐Sheng , Sun Han‐Dong
Published: August 2007

ent‐Kaurane diterpenoids are a class of natural compounds isolated from genus Isodon, which have been found to have important bioactivities. Negative electrospray ionization tandem mass spectrometry ((−)ESI‐MSn) was used to investigate the fragmentation pattern of C‐20‐nonoxygenated ent‐kauranes and two subtypes of C‐20‐oxygenated ent‐kauranes by using an ion trap instrument and accurate mass measurement on an ESI‐Q‐time‐of‐flight (TOF) mass spectrometer. The analysis revealed that loss of CH2O or CO2 is the predominant process for 7, 20‐epoxy and 7, 20 : 14, 20‐diepoxy subgroup of C‐20‐oxygenated ent‐kauranes. In addition, compounds of C‐20‐nonoxygenated ent‐kauranes with a conserved core structure but different substituent groups, such as a hydroxyl, aldehyde, carboxyl, and acetyl moiety, resulted in diagnostic product ions through losses of H2O, CO, CO2, and AcOH, respectively. This work clearly demonstrates the utility of tandem mass spectrometry for studies on the rationalization of the diagnostic fragmentation of a series of compounds from two main types of the ent‐kaurane diterpenoids. Copyright © 2007 John Wiley & Sons, Ltd.
Ranking the AR4 climate models over the Murray‐Darling Basin using simulated maximum temperature, minimum temperature and precipitation
Authors: Maxino C. C. , McAvaney B. J. , Pitman A. J. , Perkins S. E.
Published: August 2007

We assess the capacity of models submitted for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4), to simulate the maximum and minimum temperatures and precipitation over the Murray‐Darling Basin (Australia). We use daily data from the AR4 to calculate the mean of these three quantities, but we also derive probability density functions (PDFs) for each variable. We quantify the skill of each climate model to simulate the probability density function as a basis of assessing those models with significant capacity over the basin. We show that Commonwealth Scientific and Industrial Research Organization (CSIRO), Insitut Pierre Simon Laplace (IPSL), and MIROC‐m capture the observed PDFs of maximum and minimum temperature and precipitation relatively well. Other models capture one or two of these variables well but show limitations, or could not be assessed, in a third. We, therefore, recommend these three models to users of model results, but note that this recommendation is limited to this basin. However, our methodology provides quite a straightforward and quantitatively based means to choose climate models for impact assessment in any data‐rich region. Specifically, we note that to demonstrate skill in simulating the daily derived PDFs is far more challenging than just simulating the mean (as a model can simulate the mean well by averaging large biases of opposite sign). Our method therefore provides a more robust foundation for using a model in impacts assessment. Copyright © 2007 Royal Meteorological Society
Isolation and characterization of connective tissue progenitor cells derived from human fracture‐induced hemarthrosis in vitro
Authors: Lee Sang Yang , Miwa Masahiko , Sakai Yoshitada , Kuroda Ryosuke , Oe Keisuke , Niikura Takahiro , Matsumoto Tomoyuki , Fujioka Hiroyuki , Doita Minoru , Kurosaka Masahiro
Published: August 2007

In our search for alternative sources of connective tissue progenitor cells that can be obtained with minimal invasion, we studied human intraarticular fracture‐induced hemarthrosis of the knee and attempted to isolate connective tissue progenitors from the hemarthrosis. Hemarthrosis was aspirated from the knee joints of 13 patients suffering from intraarticular osteochondral fractures of the knee. Mononuclear cells were isolated from the aspirated hemarthrosis by density gradient separation, and cultured. We were able to obtain fibroblastic adherent cells from the mononuclear cell fractions. Flow cytometry analysis after in vitro expansion on tissue culture plastic revealed that the fibroblastic cells were positive for CD29, CD44, CD105, and CD166, and negative for CD14, CD34, CD45, and CD133. These cells could differentiate in vitro into osteogenic, chondrogenic, and adipogenic cells in the presence of lineage‐specific induction factors. These results demonstrate that human intraarticular fracture‐induced knee hemarthrosis contains connective tissue progenitor cells with morphologic features, immunophenotypic markers, and differentiation potential that are similar to bone marrow stromal cells. This suggests that hemarthrosis, which is easy to harvest without unnecessary invasion to the patient, has possible future clinical applications such as in tissue‐engineered therapies for severe osteochondral defects, posttraumatic osteoarthritis, and delayed fracture unions or nonunions. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:190–199, 2008
Static knee alignment is associated with the risk of unicompartmental knee cartilage defects
Authors: Janakiramanan Neela , Teichtahl Andrew J. , Wluka Anita E. , Ding Changhai , Jones Graeme , Davis Susan R. , Cicuttini Flavia M.
Published: August 2007

Although knee malalignment is a risk factor for the progression of unicompartmental knee osteoarthritis (OA), it is unclear how this relationship is mediated. Cartilage defects are known to predate cartilage loss and the onset of knee OA, and it may be that knee malalignment increases the risk of unicompartmental knee cartilage defects. Knee radiographs and MRI were performed on a total of 202 subjects, 36.6% of whom had radiographic knee OA, to determine the relationship between static knee alignment and knee cartilage defects. Analyses were performed for the entire cohort, as well as for healthy and OA subgroups. For every 1° increase in a valgus direction, there was an associated reduced risk of the presence of cartilage defects in the medial compartment of subjects with knee OA (p = 0.02), healthy subjects (p = 0.002), and the combined (p < 0.001) group. Moreover, for every 1° increase in a valgus direction, there was an associated increased risk of the presence of lateral cartilage defects in the OA group (p = 0.006), although the relationship between change toward genu valgum and lateral compartment cartilage defects did not persist for the healthy group (p = 0.16). This cross‐sectional study has demonstrated that knee alignment is associated with the risk for compartment specific knee cartilage defects in both healthy and arthritic people. Given that the natural history of cartilage volume reduction appears to be predated by the presence of cartilage defects, whether knee alignment affects the longitudinal progression from cartilage defects to cartilage loss requires further examination. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:225–230, 2008
Characterization of bixin by LC‐MS and LC‐NMR
Authors: Rehbein Jens , Dietrich Benjamin , Grynbaum Marc David , Hentschel Petra , Holtin Karsten , Kuehnle Maximilian , Schuler Paul , Bayer Marc , Albert Klaus
Published: August 2007

An overview upon modern analytical techniques for the isolation, separation, and structural identification of the essential bioactive carotenoid bixin is given. Isolation from biological matrices is performed by matrix solid phase dispersion (MSPD). The extract is separated with shape‐selective C30 columns. Structural assignment of the separated compounds is done by online LC‐MS and capillary HPLC‐NMR.
Comparison of continuous‐flow microextraction and static liquid‐phase microextraction for the determination of p‐toluidine in Chlamydomonas reinhardtii
Authors: Liu Xiujuan , Chen Xiaowen , Yang Shao , Wang Xuedong
Published: August 2007

In this study, two microextraction methods, viz. continuous‐flow microextraction (CFME) and static liquid‐phase microextraction (s‐LPME), were optimized and compared for the determination of p‐toluidine in water and Chlamydomonas reinhardtii samples. The calibration curve for p‐toluidine was linear in the concentration range of 0.01–5 μg/mL, and the squared regression coefficients (r2) for the lines were up to 0.999 for both CFME and s‐LPME treatments. Detection limits in CFME and s‐LPME were 8.2 ng/mL and 4.9 ng/mL, based on a signal‐to‐noise (S/N) ratio of 3, respectively. The precision was tested, in five replicates, by analysis of a 100‐ng/mL standard solution of p‐toluidine and the relative standard deviations were 5.43 and 3.08% for CFME and s‐LPME, respectively. The concentration factors were 5.5 and 14.4 for CFME and s‐LPME, respectively. s‐LPME has a higher extraction efficiency, lower detection limit, and higher concentration factor than that of CFME. Additionally, the s‐LPME method is precise and reproducible, and requires only a 3.0‐μL microdrop of extraction solvent. Therefore, this procedure is more convenient in use, and viable for qualitative and quantitative analysis of p‐toluidine in water and biota samples.
Separation and evaluation of free radical‐scavenging activity of phenol components of green, brown, and black leaves of Bergenia crassifolia by using HPTLC‐DPPH• method
Authors: Pozharitskaya Olga N. , Ivanova Svetlana A. , Shikov Alexander N. , Makarov Valery G. , Galambosi Bertalan
Published: August 2007

A new procedure has been developed to separate and quantify the free radical‐scavenging activity of individual compounds from green, brown, and black leaves of Bergenia crassifolia based on the combination of high performance TLC (HPTLC) with a diode array detector (DAD) and postchromatographic 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH•) derivatization. Free gallic and ellagic acids, arbutin, hydroquinone, and bergenin in the B. crassifolia leaves' extracts were separated by HPTLC and identified. All compounds of the extract excluding bergenin were capable of scavenging DPPH∗︁ radicals. From the estimated ID50 values, it can be seen that the increasing order of activity was gallic acid > arbutin > ellagic acid > hydroquinone > ascorbic acid. The antiradical activity of leaves of B. crassifolia is probably associated to the presence of phenol.
Analysis of adenosine by RP‐HPLC method and its application to the study of adenosine kinase kinetics
Authors: Marin Rodrigo Miguel , Franchini Kleber Gomes , Rocco Silvana Aparecida
Published: August 2007

An RP‐HPLC method for the analysis of adenosine (ADO) has been developed and validated. In the present study, we report an RP‐HPLC‐based method with modifications of mobile phase and shorter retention time that substantially improved the efficiency of ADO analysis. The HPLC separation of the ADO was achieved on a C18 column, using a mobile phase consisting of water, containing 7% v/v ACN, at a flow rate of 0.8 mL/min. The column effluent was monitored by UV detection at 260 nm. A linear response was achieved over the concentration range of 0.25–100.00 μmol/L. The analytical method inter‐ and intra‐run accuracy and precision were better than ± 15%. The LOQ was 0.25 μmol/L, with ADO detection in the range of 6.25 pmol per sample. The method has been applied to the study of adenosine kinase (AK) kinetics.
Effects of microtopography and erosion on seedling colonisation and survival in the volcano Usu, northern Japan, after the 1977–78 eruptions
Authors: Tsuyuzaki S. , Haruki M.
Published: August 2007

The effects of microtopographical characteristics of the thick accumulation of ash and pumice, which were produced from 1977–78 eruptions, on seedling emergence and survival were monitored on the volcano Usu, northern Japan, 10 years after the eruptions. The characteristics included microtopography, texture of volcanic deposits on ground surface, volcanic‐deposit movements, water content on ground surface and chemical nature of volcanic deposits (ignition loss, P, K and pH). Polygonum sachalinense showed a higher seed germination percentage on finer‐particle ground surface under lab conditions, and Petasites japonicus var. giganteus germinated well on the ground surface with any particle sizes. However, in the field, the seedling densities of those two species and Anaphalis margaritacea var. angustior (three dominant species in this region) were higher on the sites with coarse particles and/or the rill inside the crater basin. The seedling germination timing and space overlapped among these species in the field. Those facts suggested that the seedling colonisation pattern was influenced more by the topographical characteristics of ground surface rather than the germination abilities. The amount of organic matter in the volcanic deposits was very low, even 11 years after the eruptions, and was not related to microtopography, suggesting that the effects of organic matter on seedling emergence did not differ along microtopographical characteristics. Inside of rills, higher water content seemed to be more advantageous for seed germination of those species. Volcanic deposits were physically stable in summer, but were heavily eroded after winter due to snowmelt. Most seedlings did not overwinter in the inside of rills with pumice where the volcanic deposits eroded intensively, indicating that the patterns of land degradation by melting snow should be mentioned carefully even with narrow scale. Copyright © 2007 John Wiley & Sons, Ltd.
Oxidation protective coatings for γ‐TiAl – recent trends
Authors: Fröhlich M. , Ebach‐Stahl A. , Braun R. , Leyens C.
Published: August 2007

Engine designers show continued interest in γ‐TiAl based titanium aluminides as light–weight structural materials to be used at moderately elevated temperatures. Although alloy development has made significant progress in terms of mechanical properties and environmental resistance, protective coatings have been developed that help to extend the lifetime of these alloys significantly. The major challenge of coating development is to prevent the formation of fast growing titania. Furthermore, changes of coating chemistries at high temperatures have to be considered in order to avoid rapid degradation of the coatings due to interdiffusion between substrate and coating.

The paper describes recent work of the authors on different coatings produced by means of magnetron sputter technique. Thin ceramic Ti‐Al‐Cr‐Y‐N layers tested at 900 °C exhibited poor oxidation resistance. In contrast, intermetallic Ti‐Al‐Cr, Si‐based and aluminum rich Ti‐Al coatings were tested at exposure temperatures up to 950 °C for 1000h resulting in reasonable and partially excellent oxidation behaviour.
Environmentally assisted cracking of aluminium alloys
Authors: Braun R.
Published: August 2007

A short review of the stress corrosion cracking (SCC) behaviour of aluminium alloys is given. Mechanisms of environmentally assisted cracking are outlined. For aluminium alloys, in which stress corrosion cracks propagate predominantly along grain boundaries, anodic dissolution and hydrogen embrittlement have been proposed. Transgranular stress corrosion cracking occurring at severe loading conditions has found particular interest concerning localised corrosion‐deformation interactions. Accelerated test methods for assessing the SCC behaviour are described, including the slow strain rate testing technique and the breaking load method. Results of recent studies on environmentally assisted cracking of aluminium alloys are summarised. Most of the work published in the last two decades has been on aluminium‐lithium based alloys and improved high strength Al‐Zn‐Mg‐Cu alloys in corrosion resistant retrogressed and re‐aged tempers.
Faser‐ und drahtverstärkte Kupferlegierungen als Wärmesenke für Fusionsreaktoren
Authors: Peters P. W. M. , Hemptenmacher J. , Schurmann H.
Published: August 2007

Die CuCr1Zr‐Legierung wird wegen ihrer mechanischen Eigenschaften und Leitfähigkeit (310–330 W/m/K bei 20 °C) in bestehenden und zukünftigen experimentellen Fusionsreaktoren (wie z.B. ITER) als Wärmesenke eingesetzt. Diese warmaushärtbare Legierung ist wegen der Alterung nur bis zu Temperaturen von 450 °C einsetzbar. Eine Möglichkeit die Einsatztemperatur zu erhöhen (angestrebt wird 550 °C) besteht in einer Verstärkung mit SiC‐Fasern oder W‐Drähten. Mit Hilfe von mit der CuCr1Zr‐Legierung beschichteten SiC (SCS‐6)‐Fasern und W‐Drähten (beide mit einem Durchmesser von ∼150 μm) wurden Cu‐MMCs (Kupfer‐Metallmatrix‐Verbundwerkstoffe) hergestellt und deren Eigenschaften (Grenzflächeneigenschaften, Festigkeit, thermische Leitfähigkeit) ermittelt. Nach der Konsolidierung durch Heiß‐Isostatisches‐Pressen ist die Kupfermatrix gealtert, so dass eine zusätzliche Warmaushärtung notwendig ist, um optimale Verbundeigenschaften zu realisieren. Die Festigkeit der verschiedenen Cu‐MMCs wurden in Abhängigkeit des Volumenanteils der Verstärkungselemente bestimmt. Die Zugfestigkeit steigt mit zunehmendem Volumenanteil der Fasern oder Drähte und erreicht z. B. eine Zugfestigkeit von 1000 MPa bei einem Faservolumenanteil von 24 % oder Drahtvolumenanteil von 27 %. Wärmeleitfähigkeitsmessungen, mit Hilfe einer Laserflash‐Anlage durchgeführt, zeigen, dass die thermische Leitfähigkeit mit zunehmendem Faservolumenanteil abnimmt (sie beträgt z. B. 200 W/m/K bei einem SiC‐Faservolumenanteil von 30 %). Die W‐drahtverstärkte CuCr1Zr‐Legierung wird auf Grund der besseren Leitfähigkeit und Grenzflächeneigenschaften ausgewählt, um das Potential von Cu‐MMCs für Wärmesenken in einer ersten Entwurfstudie am Beispiel unterschiedlicher Divertorbautypen abzuschätzen.
Statistical framework and noise sensitivity of the amplitude radial correlation contrast method
Authors: Kipervaser Zeev Gideon , Pelled Galit , Goelman Gadi
Published: August 2007

A statistical framework for the amplitude radial correlation contrast (RCC) method, which integrates a conventional pixel threshold approach with cluster‐size statistics, is presented. The RCC method uses functional MRI (fMRI) data to group neighboring voxels in terms of their degree of temporal cross correlation and compares coherences in different brain states (e.g., stimulation OFF vs. ON). By defining the RCC correlation map as the difference between two RCC images, the map distribution of two OFF states is shown to be normal, enabling the definition of the pixel cutoff. The empirical cluster‐size null distribution obtained after the application of the pixel cutoff is used to define a cluster‐size cutoff that allows 5% false positives. Assuming that the fMRI signal equals the task‐induced response plus noise, an analytical expression of amplitude‐RCC dependency on noise is obtained and used to define the pixel threshold. In vivo and ex vivo data obtained during rat forepaw electric stimulation are used to fine‐tune this threshold. Calculating the spatial coherences within in vivo and ex vivo images shows enhanced coherence in the in vivo data, but no dependency on the anesthesia method, magnetic field strength, or depth of anesthesia, strengthening the generality of the proposed cutoffs. Magn Reson Med 58:554–561, 2007. © 2007 Wiley‐Liss, Inc.
Optimized balanced steady‐state free precession magnetization transfer imaging
Authors: Bieri O. , Scheffler K.
Published: August 2007

Balanced steady‐state free precession (bSSFP) suffers from a considerable signal loss in tissues. This apparent signal reduction originates from magnetization transfer (MT) and may be reduced by an increase in repetition time or by a reduction in flip angle. In this work, MT effects in bSSFP are modulated by a modification of the bSSFP sequence scheme. Strong signal attenuations are achieved with short radio frequency (RF) pulses in combination with short repetition times, whereas near full, i.e., MT‐free, bSSFP signal is obtained by a considerable prolongation of the RF pulse duration. Similar to standard methods, the MT ratio (MTR) in bSSFP depends on several sequence parameters. Optimized bSSFP protocol settings are derived that can be applied to various tissues yielding maximal sensitivity to MT while minimizing contribution from other impurities, such as off‐resonances. Evaluation of MT in human brain using such optimized bSSFP protocols shows high correlation with MTR values from commonly used gradient echo (GRE) sequences. In summary, a novel method to generate MTR maps using bSSFP image acquisitions is presented and factors that optimize and influence this contrast are discussed. Magn Reson Med 58:511–518, 2007. © 2007 Wiley‐Liss, Inc.
Oxygenation and hematocrit dependence of transverse relaxation rates of blood at 3T
Authors: Zhao Jason M. , Clingman Chekesha S. , Närväinen M. Johanna , Kauppinen Risto A. , van Zijl Peter C.M.
Published: August 2007

Knowledge of the transverse relaxation rates R2 and R of blood is relevant for quantitative assessment of functional MRI (fMRI) results, including calibration of blood oxygenation and measurement of tissue oxygen extraction fractions (OEFs). In a temperature controlled circulation system, these rates were measured for blood in vitro at 3T under conditions akin to the physiological state. Single spin echo (SE) and gradient echo (GRE) sequences were used to determine R2 and R, respectively. Both rates varied quadratically with deoxygenation, and changes in R were found to be due predominantly to changes in R2. These data were used to estimate intravascular blood oxygenation level dependent (BOLD) contributions during visual activation. Due to the large R in venous blood, intravascular SE BOLD signal changes were larger than GRE effects at echo times above 30 ms. When including extravascular effects to estimate the total BOLD effect, GRE BOLD dominated due to the large tissue volume fraction. Magn Reson Med 58:592–596, 2007. © 2007 Wiley‐Liss, Inc.
Assessing atrophy of the major white matter fiber bundles of the brain from diffusion tensor MRI data
Authors: Pagani Elisabetta , Horsfield Mark A. , Rocca Maria A. , Filippi Massimo
Published: August 2007

Brain atrophy is a typical feature of many neurological conditions. Therefore, quantitative evaluation and spatial characterization of atrophy are potentially useful for monitoring the evolution of central nervous system (CNS) disorders. In this study, a method for measuring atrophy of the major white matter (WM) fiber bundles in the brain using diffusion tensor (DT) MRI data is developed. To this end, an atlas was created from sets of diffusion anisotropy images from normal subjects, and the deformations necessary to match single subject anisotropy images to this atlas were then computed. Because diffusion anisotropy images were used, this approach should be sensitive to fiber bundle volume changes in the same way that using T1‐weighted images allows gray matter volume changes to be measured. The Jacobian determinant of the deformation field for each subject was then used as a measure of contraction or expansion of the tissue at each image voxel. An overview of the nonlinear registration problem is given; then an optimization of the parameters for the chosen algorithm is performed and the method for producing the atlas is described. The effectiveness of the method was then tested on data from five patients with multiple sclerosis (MS) and two patients with amyotrophic lateral sclerosis (ALS). Magn Reson Med 58:527–534, 2007. © 2007 Wiley‐Liss, Inc.
Feasibility of multiple‐mouse dynamic contrast‐enhanced MRI
Authors: Ramirez Marc S. , Ragan Dustin K. , Kundra Vikas , Bankson James A.
Published: August 2007

Dynamic contrast‐enhanced (DCE‐) MRI is often used to evaluate the response to experimental antiangiogenic therapies in small animal models of cancer. Unfortunately, DCE‐MRI studies often require a substantial investment of both time and money to achieve the desired level of statistical significance. Multiple‐mouse MRI has previously been used to improve imaging efficiency, but its feasibility for DCE‐MRI has not been investigated. The purpose of this work was to determine if multiple‐mouse DCE‐MRI is feasible when using gadolinium‐based contrast agents with a low molecular weight. A population of tumor‐bearing mice was scanned using two four‐element arrays and a single‐coil configuration on a 4.7T, 40 cm bore Bruker Biospec MRI scanner. Pharmacokinetic parameters were calculated and compared to determine if a significant difference between methodologies existed. With both four‐animal imaging configurations, animal throughput accelerations of just less than three were achieved and quantitative data were not significantly different than from single‐animal acquisitions. Magn Reson Med 58:610–615, 2007. © 2007 Wiley‐Liss, Inc.
Quantifying the blood oxygenation level dependent effect in cerebral blood volume–weighted functional MRI at 9.4T
Authors: Lu Hanbing , Scholl Clara A. , Zuo Yantao , Stein Elliot A. , Yang Yihong
Published: August 2007

In cerebral blood volume (CBV)‐weighted functional MRI (fMRI) employing superparamagnetic contrast agent, iron dose and blood oxygenation level dependent (BOLD) contamination are two important issues for experimental design and CBV quantification. Both BOLD and CBV‐weighted fMRI are based upon the susceptibility effect, to which spin‐echo and gradient‐echo sequences have different sensitivities. In the present study, CBV‐weighted fMRI was conducted using spin‐echo and gradient‐echo sequences at 9.4T by systematically changing the doses of contrast agent. Results suggest that BOLD contamination is a significant component in CBV‐weighted fMRI at high field, particularly when relatively low dose of contrast agent is administered. A mathematical model was developed to quantify the extravascular (EV) BOLD effect. With a TE of 35 ms, the EV BOLD effect was estimated to account for 76 ± 12% of the observed spin‐echo fMRI signal at 9.4T. These data suggest that correcting BOLD effect may be necessary for accurately quantifying activation‐induced CBV changes at high field. Magn Reson Med 58:616–621, 2007. © 2007 Wiley‐Liss, Inc.
Unique patterns of diffusion directionality in rat brain tumors revealed by high‐resolution diffusion tensor MRI
Authors: Zhang Jiangyang , van Zijl Peter C.M. , Laterra John , Salhotra Amandeep , Lal Bachchu , Mori Susumu , Zhou Jinyuan
Published: August 2007

Diffusion tensor imaging (DTI) is a new technique that uses the microscopic motion of water molecules to probe tissue 3D microstructures. In this study, high‐resolution DTI was performed on rats bearing intracranial 9L gliosarcoma, F98 glioma, and human glioblastoma. It was found that the tumors consisted of central zones with low diffusion anisotropy and peripheral structures (rim) with high diffusion anisotropy. In the rims, water diffusion directionality formed a circular pattern for the 9L and F98 tumors, and a radial pattern for the human glioblastoma xenografts. These well‐organized diffusion patterns appeared at an early stage postimplantation and continued to exist with tumor growth in all three models. High‐resolution ex vivo imaging and histology confirmed the in vivo findings. These distinct patterns, undetectable with conventional MRI, may reflect tumor organization and growth patterns at the cellular level. Magn Reson Med 58:454–462, 2007. © 2007 Wiley‐Liss, Inc.
Severe Guillain–Barré syndrome associated with chromosome 17p11.2‐12 duplication
Authors: Münch Christoph , Epplen Jörg T. , Meins Moritz , Meyer Robert , Weber Jörg R. , Meyer Thomas
Published: August 2007

We report a patient with Guillain–Barré syndrome (GBS), characterized by severe tetraparesis, bulbar syndrome, and ophthalmoparesis. The nadir was reached within 1 day, followed by respiratory insufficiency requiring mechanical ventilation. Molecular analysis revealed a duplication at chromosome 17p11.2‐12, which is a known genetic cause of Charcot–Marie–Tooth disease type 1A (CMT1A). We suggest that this genotype may comprise a previously unrecognized genetic risk factor for GBS. Muscle Nerve, 2007
Diagnostic validity of epidermal nerve fiber densities in painful sensory neuropathies
Authors: Vlčková‐Moravcová Eva , Bednařík Josef , Dušek Ladislav , Toyka Klaus V. , Sommer Claudia
Published: August 2007

In this prospective study, intraepidermal nerve fiber densities (IENFD) and subepidermal nerve plexus densities (SENPD) were quantified by immunostaining in skin punch biopsies from the distal calf in 99 patients with clinical symptoms of painful sensory neuropathy and from 37 age‐matched healthy volunteers. The clinical diagnosis was based on history and abnormal thermal thresholds on quantitative sensory testing (QST). In patients with neuropathy, IENFD and SENPD were reduced to about 50% of controls. Elevated warm detection thresholds on QST correlated with IENFD but not with SENPD. Using receiver‐operating characteristic (ROC) curve analysis of IENFD values, the diagnostic sensitivity for detecting neuropathy was 0.80 and the specificity 0.82. For SENPD, sensitivity was 0.81 and specificity 0.88. With ROC analysis of both IENFD and SENPD together, the diagnostic sensitivity was further improved to 0.92. The combined examination of IENFD and SENPD is a highly sensitive and specific diagnostic tool in patients suspected to suffer from painful sensory neuropathies but with normal values on clinical neurophysiological studies. Muscle Nerve, 2007
An Italian family with inclusion‐body myopathy and frontotemporal dementia due to mutation in the VCP gene
Authors: Gidaro Teresa , Modoni Anna , Sabatelli Mario , Tasca Giorgio , Broccolini Aldobrando , Mirabella Massimiliano
Published: August 2007

Mutations of the valosin‐containing protein gene (VCP) are responsible for autosomal‐dominant hereditary inclusion‐body myopathy associated with frontotemporal dementia and Paget's disease of bone. We identified the p.R155C missense mutation in the VCP gene segregating in an Italian family with three affected siblings, two of whom had a progressive myopathy associated with dementia, whereas one exhibited a progressive myopathy and preclinical signs of Paget's disease of bone. Our study demonstrates that VCP mutations are found in patients of Italian background and may lead to a variable clinical phenotype even within the same kinship. Muscle Nerve, 2007
Decrease in peripheral muscle strength and ankle dorsiflexion as long‐term side effects of treatment for childhood cancer
Authors: Hartman Annelies , van den Bos Cor , Stijnen Theo , Pieters Rob
Published: August 2007

Background

This study investigated muscle strength, passive ankle dorsiflexion, and their association with motor performance in children after treatment for acute lymphoblastic leukemia, Wilms tumor, B‐non‐Hodgkin lymphoma, and malignant mesenchymal tumors.

Procedure

Muscle strength was assessed with a hand‐held dynamometer and ankle dorsiflexion with a goniometer in 92 and 64 survivors, respectively. Motor performance was measured with the Movement Assessment Battery for Children (movement‐ABC). Age at testing: 6.1–12.9 years. Mean time since completing treatment: 3.3 years. Results were compared to 155 healthy controls.

Results

Muscle strength of the survivors was reduced in ankle dorsiflexors on both sides (P < 0.001), wrist dorsiflexors on the non‐dominant side (P < 0.001), and pinch grip on the non‐dominant (P = 0.001) and dominant side (P = 0.01). Passive ankle dorsiflexion of the survivors was significantly less on both sides (P < 0.01). Movement‐ABC percentile score was affected by pinch grip strength on the non‐dominant (P < 0.004), and dominant side (P = 0.024) but not by strength of other muscle groups or by passive ankle dorsiflexion.

Conclusion

Peripheral muscle strength and ankle dorsiflexion are reduced in the long‐term in children treated for cancer with chemotherapy. However, neither decreased muscle strength nor reduced ankle dorsiflexion could completely explain reduced scores on the movement‐ABC. Pediatr Blood Cancer. Pediatr Blood Cancer 2008;50:833–837. © 2007 Wiley‐Liss, Inc.
Comment on Anderson and Ones (2008)
Authors: Goldberg Lewis R. , Lee Kibeom , Ashton Michael C.
Published: August 2007

The ‘erratum and addendum’ by Anderson and Ones (2008) does not state unambiguously that participants' Hogan Personality Inventory (HPI) scale scores were incorrectly matched with their scores on the other inventories' scales, nor does it mention the existence of other errors in the scoring of the Occupational Personality Questionnaire (OPQ) and Business Personality Indicator (BPI) scales. We demonstrate these errors and we recommend the retraction of the articles by Anderson and Ones (2003) and Ones and Anderson (2002). Copyright © 2007 John Wiley & Sons, Ltd.