bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo bone and cartilage MRI using fully‐balanced steady‐state free‐precession at 7 tesla
Authors: Krug Roland , Carballido‐Gamio Julio , Banerjee Suchandrima , Stahl Robert , Carvajal Lucas , Xu Duan , Vigneron Dan , Kelley Douglas A.C. , Link Thomas M. , Majumdar Sharmila 
Published: October 2007

AbstractThe purpose of this work was to investigated the feasibility of fully‐balanced steady‐state free‐precession (bSSFP) pulse sequence for trabecular bone and knee cartilage imaging in vivo using ultra‐high‐field (UHF) MRI at 7T in comparison with pulse sequences previously used at 3T. We showed that bSSFP and spin‐echo imaging is possible at higher field strengths within 3.2 W/kg specific absorption rate (SAR) constraints. All pulse sequences were numerically optimized based on measured tissue relaxation parameters from six healthy volunteers (T1 = 820 ± 128 ms, T2 = 43.5 ± 3 ms for bone marrow and T1 = 1745 ± 104 ms and T2 = 30 ± 4 ms for cartilage). From simulations of the Bloch equation, a signal‐to‐noise ratio (SNR) increase of more than 1.9 was predicted. Cartilage SNR of bSSFP was 2.4 times higher at 7T (51.3 ± 4.3) compared with 3T (21.3 ± 3.3). Bone SNR increased from 11.8 ± 2.0 to 13.2 ± 2.5 at the higher field strength. We concluded that there is SNR benefit and great potential for bone and cartilage imaging at higher field strength. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Short‐TE localised 1H MRS of the human brain at 3 T: quantification of the metabolite signals using two approaches to account for macromolecular signal contributions
Authors: Gottschalk Michael , Lamalle Laurent , Segebarth Christoph 
Published: October 2007

AbstractThe goal of this study was to validate metabolite quantification at short TE, with particular focus on how to best account for the macromolecular signal contribution. A robust, short‐TE PRESS protocol is presented, which allows reliable quantification, in vivo, of metabolite signals at 3 T in human brain. Water suppression was adapted to the experimental conditions at 3 T. Metabolite signal from the parietal white matter was quantified in the time domain using QUEST (jMRUI). The increased macromolecular signal contribution at short TE was dealt with by two approaches, based on either metabolite nulling or initial signal truncation. A detailed comparison of the two approaches was made. The first used a metabolite‐nulled signal, measured either individually or averaged over different subjects. The second used the total signal, metabolites and macromolecules, from a single scan. The two approaches gave similar quantification results in terms of metabolite concentrations, but differed in their precision and the number of metabolites quantified reliably. With an average metabolite‐nulled baseline, a set of seven metabolites could be reliably quantified in parietal white matter under these experimental conditions: N‐acetylaspartate, myo‐inositol, glucose, glutamate, glutathione, creatine and choline. When initial signal truncation was used, glucose was removed from this set. The short TE (10–11 ms) facilitated quantification of glutamate. The reliable quantification of N‐acetylaspartyl glutamate at 3 T proved very difficult. Copyright © 2007 John Wiley & Sons, Ltd.
Bevacizumab gegen Dickdarmkarzinom. Angiogenese‐Hemmung in der Krebstherapie
Authors: Fieth Christian , Kebig Anna , Mohr Klaus 
Published: October 2007

AbstractAus medizinischer Sicht ist eine zusätzliche Therapie mit dem Angiogenese‐Hemmstoff Bevacizumab in der Chemotherapie des kolorektalen Karzinoms wirksam, da die Zulassungsstudie eine signifikant längere Überlebensdauer und Zeit bis zur Tumorprogression ergab. Pharmakoökonomisch ist zu beachten, dass zusätzliche Therapiekosten von ca. 4000 R pro Monat anfallen. Kürzlich wurde Bevacizumab für die Kombinationstherapie des Mammakarzinoms zugelassen. Derzeit laufen Studien, in denen untersucht wird, ob Bevacizumab auch bei anderen Karzinomerkrankungen, wie z.B. dem metastasierten Nierenzellkarzinom und Pankreaskarzinom, wirksam ist. In den USA ist der Antikörper bereits zur Primärtherapie des metastasierten nichtkleinzelligen Bronchialkarzinoms zugelassen.Bevacizumab wird ohne Zulassung bei der feuchten altersbedingten Makuladegeneration (AMD) eingesetzt. Aus Bevacizumab ist das Antikörperfragment Ranibizumab hervorgegangen, welches zur Behandlung der feuchten Form der altersbedingten Makuladegeneration zugelassen ist (siehe Beitrag zu Ranibizumab von Mohr‐Andrä & Mohr in diesem Heft).
Frequency dependence of hysteresis associated with the electromechanical performance of PVDF film
Authors: Hughes O. Richard 
Published: October 2007

AbstractThe thickness strains, the electric displacements, and the hysteresis exhibited by poly(vinylidene fluoride) films under sinusoidal applied electric fields were measured over a range of frequencies from 0.05 to 100 Hz. The loops of strain‐ and electric displacement versus electric field exhibit a shape and hysteresis that undergoes a continuous and reversible change with frequency. At lower frequencies (<5 Hz), the shape and large hysteresis are characteristic of a ferroelectric with degrees of remanent polarization. At higher frequencies (>5 Hz), the shape and slight hysteresis of the loops are representative of a nonremanently polarized ferroelectric. This dependence of shape and hysteresis on frequency is attributed to the difference in rates between the rapid rate by which the polarization of domains of aligned dipoles is reversed in a periodic field and the slower rate by which the polarization is made remanent. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3207–3214, 2007
Have men been overlooked? A comparison of young men and women's experiences of chemotherapy‐induced alopecia
Authors: Hilton Shona , Hunt Kate , Emslie Carol , Salinas Maria , Ziebland Sue 
Published: October 2007

Abstract
Objective: The objective of this study is to compare men and women's accounts of chemotherapy‐induced alopecia.Design: Secondary analysis of narrative interview data.Participants: Thirty‐seven people aged 18–38 years, including 11 men and 8 women who had experienced hair loss, interviewed between 2000 and 2005.Setting: Participants were recruited throughout the United Kingdom.Results: Hair loss made many men and women acutely aware of their vulnerability and visibility as a ‘cancer patient’. Both men and women described a sense of strangeness or shock when they lost their hair and experienced various negative reactions when people assumed their hairless appearance was a lifestyle choice. The most striking contrast in men's and women's accounts was that women spoke solely of the loss of hair from the head and face above the eye line, and men spoke about losing hair from wider body surfaces. Only women mentioned being encouraged by others to disguise or to prevent hair loss. The results are discussed in relation to gendered assumptions about the distribution of body hair.Conclusions: Contrary to prevailing assumptions, both women and men described negative (and often similar) feelings about hair loss. Understanding these experiences can help professionals better equip their patients to deal with this aspect of their treatment. Copyright © 2007 John Wiley & Sons, Ltd.
Being the next of kin of a person with a low‐grade glioma
Authors: Edvardsson Tanja , Ahlström Gerd 
Published: October 2007

AbstractThere is a paucity of knowledge for health‐care professionals who come into contact with next of kin of persons diagnosed with low‐grade gliomas. Therefore, the aim of this study was to explore the experience of being the next of kin of an adult person diagnosed with a low‐grade glioma.Twenty‐eight next of kin of persons with a low‐grade glioma were interviewed. The data were subjected to qualitative content analysis. A quantitative data analysis was added to explore how the themes from the qualitative analysis occurred among different next of kin.Four main themes emerged: Extremely stressful emotions, Being invisible and neglected, Changed relations and roles, and Enabling strength in everyday life. The first of these occurred mainly in the early period of illness. This theme was especially predominant in the case of the patient's parents. The theme of Changed relations and roles occurred more often among next of kin some years after the person's diagnosis. The most statements occurred in all four themes were by female next of kin.Many next of kin requested emotional support for themselves and indicated that it is important that health‐care staff should not forget them. Copyright © 2007 John Wiley & Sons, Ltd.
Predictors of employment and lost hours from work in cancer caregivers
Authors: Sherwood Paula R. , Donovan Heidi S. , Given Charles W. , Lu Xiaoli , Given Barbara A. , Hricik Allison , Bradley Sarah 
Published: October 2007

AbstractThis cross‐sectional, descriptive study identified variables associated with caregivers who (1) were employed and (2) reported lost hours from work due to care demands. Family caregivers (N=80) of persons with a primary malignant brain tumor participated in a 45–60 min telephone interview, answering questions regarding the impact of providing care on their emotional health and employment status. Younger caregivers were more likely to be employed. Caregivers were more likely to report lost hours from work when care recipients required assistance with Instrumental Activities of Daily Living (IADLs) and were closer to the time of diagnosis. Data suggest that interventions to assist caregivers in maintaining employment should target caregivers of persons with limitations in physical function and should include strategies to coordinate care to assist with IADLs. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of protein dynamics from residual dipolar couplings using the three dimensional Gaussian axial fluctuation model
Authors: Bouvignies Guillaume , Markwick Phineus R. L. , Blackledge Martin 
Published: October 2007

AbstractResidual dipolar couplings are potentially very powerful probes of slower protein motions, providing access to dynamic events occurring on functionally important timescales up to the millisecond. One recent approach uses the three dimensional Gaussian Axial Fluctuation model (3D GAF) to determine the major directional modes and associated amplitudes of motions along the peptide chain. In this study we have used standard and accelerated molecular dynamics simulations to determine the accuracy of 3D GAF‐based approaches in characterizing the nature and extent of local molecular motions. We compare modes determined directly from the trajectories with motional parameterization derived from RDCs simulated from the same trajectories. Three approaches are tested, that either suppose a known three‐dimensional structure, simultaneously determine backbone structure and dynamics, or determine dynamic modes in the absence of a structural model. The results demonstrate the robustness of the 3D GAF analysis even in the presence of large‐scale motions, and illustrate the remarkably quantitative nature of the extracted amplitudes. These observations suggest that the approach can be generally used for the study of functionally interesting biomolecular motions. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Residue conservation in viral capsid assembly
Authors: Bahadur Ranjit P. , Janin Joël 
Published: October 2007

AbstractTo evaluate the evolutionary constraints placed on viral proteins by the structure and assembly of the capsid, we calculate Shannon entropies in the aligned sequences of 45 polypeptide chains in 32 icosahedral viruses, and relate these entropies to the residue location in the three‐dimensional structure of the capsids. Three categories of residues have entropies lower than the chain average implying that they are better conserved than average: residues that are buried within a subunit (the protein core), residues that contain atoms buried at an interface between subunits (the interface core), and residues that contribute to several such interfaces. The interface core is also conserved in homomeric proteins and in transient protein–protein complexes, which have only one interface whereas capsids have many. In capsids, the subunit interfaces implicate most of the polypeptide chain: on average, 66% of the capsid residues are at an interface, 34% at more than one, and 47% at the interface core. Nevertheless, we observe that the degree of residue conservation can vary widely between interfaces within a capsid and between regions within an interface. The interfaces and regions of interfaces that show a low sequence variability are likely to play major roles in the self‐assembly of the capsid, with implications on its mechanism that we discuss taking adeno‐associated virus as an example. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Structure of the Drosophila nucleosome core particle highlights evolutionary constraints on the H2A‐H2B histone dimer
Authors: Clapier Cedric R. , Chakravarthy Srinivas , Petosa Carlo , Fernández‐Tornero Carlos , Luger Karolin , Müller Christoph W. 
Published: October 2007

AbstractWe determined the 2.45 Å crystal structure of the nucleosome core particle from Drosophila melanogaster and compared it to that of Xenopus laevis bound to the identical 147 base‐pair DNA fragment derived from human α‐satellite DNA. Differences between the two structures primarily reflect 16 amino acid substitutions between species, 15 of which are in histones H2A and H2B. Four of these involve histone tail residues, resulting in subtly altered protein–DNA interactions that exemplify the structural plasticity of these tails. Of the 12 substitutions occurring within the histone core regions, five involve small, solvent‐exposed residues not involved in intraparticle interactions. The remaining seven involve buried hydrophobic residues, and appear to have coevolved so as to preserve the volume of side chains within the H2A hydrophobic core and H2A‐H2B dimer interface. Thus, apart from variations in the histone tails, amino acid substitutions that differentiate Drosophila from Xenopus histones occur in mutually compensatory combinations. This highlights the tight evolutionary constraints exerted on histones since the vertebrate and invertebrate lineages diverged. Proteins 2008. © 2007 Wiley‐Liss, Inc.
N‐linked glycans of the human insulin receptor and their distribution over the crystal structure
Authors: Sparrow Lindsay G. , Lawrence Michael C. , Gorman Jeffrey J. , Strike Phillip M. , Robinson Christine P. , McKern Neil M. , Ward Colin W. 
Published: October 2007

AbstractThe human insulin receptor (IR) homodimer is heavily glycosylated and contains a total of 19 predicted N‐linked glycosylation sites in each monomer. The recent crystal structure of the IR ectodomain shows electron density consistent with N‐linked glycosylation at the majority of sites present in the construct. Here, we describe a refined structure of the IR ectodomain that incorporates all of the N‐linked glycans and reveals the extent to which the attached glycans mask the surface of the IR dimer from interaction with antibodies or other potential therapeutic binding proteins. The usefulness of Fab complexation in the crystallization of heavily glycosylated proteins is also discussed. The compositions of the glycans on IR expressed in CHO‐K1 cells and the glycosylation deficient Lec8 cell line were determined by protease digestion, glycopeptide purification, amino acid sequence analysis, and mass spectrometry. Collectively the data reveal: multiple species of complex glycan at residues 25, 255, 295, 418, 606, 624, 742, 755, and 893 (IR‐B numbering); multiple species of high‐mannose glycan at residues 111 and 514; a single species of complex glycan at residue 671; and a single species of high‐mannose glycan at residue 215. Residue 16 exhibited a mixture of complex, hybrid, and high‐mannose glycan species. Of the remaining five predicted N‐linked sites, those at residues 397 and 906 were confirmed by amino acid sequencing to be glycosylated, while that at residue 78 and the atypical (NKC) site at residue 282 were not glycosylated. The peptide containing the final site at residue 337 was not recovered but is seen to be glycosylated in the electron density maps of the IR ectodomain. The model of the fully glycosylated IR reveals that the sites carrying high‐mannose glycans lie at positions of relatively low steric accessibility. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Examples of Charging Effects on the Spectral Quality of X‐ray Microanalysis on a Glass Sample Using the Variable Pressure Scanning Electron Microscope
Authors: Le Berre J. F. , Demers H. , Demopoulos G. P. , Gauvin R. 
Published: October 2007

AbstractThe performance of X‐ray microanalysis in the variable pressure or environmental scanning electron microscope (VP‐SEM or ESEM®) is limited by skirting. Under certain conditions, charging effects can occur and change the X‐ray emission, which affects the X‐ray microanalysis. The conventional way to evaluate charging is to calculate the Duane‐Hunt limit by fitting the X‐ray intensity region located below the energy cut‐off. Nevertheless, this method appears to have serious limitations for instance in the case of strong insulators. A perfect example of this limitation is to study the evolution of composition of an alkali glass with time. This paper reports on the evolution of the sodium X‐ray intensity with time depending on accelerating voltage, pressure and presence of a surface coating. For certain conditions, a decrease of sodium X‐ray intensity with time was observed but for other conditions the reverse behavior was noticed. The increase of sodium X‐ray intensity with time was obtained when the force created by the surface electrons was stronger than the force generated by electrons trapped in the interaction volume, whereas the decrease of sodium X‐ray intensity occurred when the force generated by electrons trapped in the interaction volume was the stronger. The variations of sodium X‐ray intensity were also compared to the variation of the Duane‐‐Hunt limit, the determination of which is studied in detail in this article. SCANNING 29: 270–271, 2007. © 2007 Wiley Periodicals, Inc.
Sample size calculations in the presence of competing risks
Authors: Latouche A. , Porcher R. 
Published: October 2007

AbstractRecently, with the growth of statistical developments for competing risks analysis, some methods have been proposed to compute sample size in this context. These methods differ from a modelling approach: one is based on the Cox regression model for the cause‐specific hazard, while another relies on the Fine and Gray regression model for the subdistribution hazard of a competing risk. In this work, we compare these approaches, derive a new sample size for comparing cumulative incidence functions when the hazards are not proportional (either cause‐specific or subdistribution) and give practical advices to choose the approach best suited for the study question. Copyright © 2007 John Wiley & Sons, Ltd.
Automated discovery of state transitions and their functions in source code
Authors: Walkinshaw Neil , Bogdanov Kirill , Ali Shaukat , Holcombe Mike 
Published: October 2007

AbstractFinite‐state machine specifications form the basis for a number of rigorous state‐based testing techniques and can help to understand program behaviour. Unfortunately they are rarely maintained during software development, which means that these benefits can rarely be fully exploited. This paper describes a technique that, given a set of states that are of interest to a developer, uses symbolic execution to reverse‐engineer state transitions from source code. A particularly novel aspect of our approach is that, besides determining whether or not a state transition can take place, it also identifies the paths through the source code that govern a transition. The technique has been implemented as a prototype, enabling its preliminary evaluation with respect to real software systems. Copyright © 2007 John Wiley & Sons, Ltd.
Continuous nicotine administration produces selective, age‐dependent structural alteration of pyramidal neurons from prelimbic cortex
Authors: Bergstrom Hadley C. , McDonald Craig G. , French Helen T. , Smith Robert F. 
Published: October 2007

AbstractEmerging evidence indicates that adolescence represents a developmental window of enhanced nicotine‐induced neuroplasticity in rat forebrain. However, whether nicotine produces age‐dependent structural alteration of neurons from medial prefrontal cortex remains to be determined. We characterized the dendritic morphology of layer V pyramidal neurons from prelimbic cortex following adolescent (P29‐43) or adult (P80‐94) nicotine pretreatment. Nicotine administration was via osmotic pump [initial dose 2.0 mg/(kg day), free base]. Five weeks after drug administration concluded, brains were processed for Golgi‐Cox staining and pyramidal neurons digitally reconstructed for morphometric analysis. Overall, nicotine pretreatment produced increased basilar, but not apical, dendritic length of pyramidal cells, a finding consistent with previous work using adult animals. Given the compelling evidence for morphologically distinct functional subtypes of cortical pyramidal neurons, we endeavored to determine whether nicotine‐induced dendritic alteration was specific to putative structural subtypes. Neurons were segregated into two groups based on the extent of dendritic arbor at the distal portion of the apical tree (i.e., the apical tuft). The size of the apical tuft was quantitatively determined using principal component analysis. Cells with small and elaborate apical tufts were classified as simple and complex, respectively. We found that adult nicotine pretreatment produced increased basilar dendritic length and branch number in simple but not complex pyramidal cells. In contrast, adolescent nicotine pretreatment produced a modest but significant increase in basilar dendritic length in complex but not simple cells. These data suggest that nicotine alters dendritic morphology of specific subpopulations of pyramidal neurons and that the subpopulation affected is dependent on the age of drug exposure. Synapse 62:31–39, 2008. © 2007 Wiley‐Liss, Inc.
Minimally Invasive Ablative Therapies for Invasive Breast Carcinomas: An Overview of Current Literature
Authors: van Esser Stijn , van den Bosch Maurice A. A. J. , van Diest Paul J. , Mali Willem Th. M. , Borel Rinkes Inne H. M. , van Hillegersberg Richard 
Published: October 2007

AbstractBackgroundMinimally invasive treatment may be an alternative to breast‐conserving surgery.MethodsA structured PubMed, Embase, Cochrane, and Web of Science search was performed. Endpoints studied were feasibility, completeness of ablation, timing of the sentinel node biopsy (SNB), imaging modalities, and treatment‐related complications.ResultsA total of 24 articles were retrieved, and the level of evidence varied (2B‐4). Mainly phase II studies with a treat‐and‐resect protocol were analyzed. Up to 100% completeness of ablation was reported for radiofrequency ablation (RFA), cryosurgery, and focused ultrasound (FUS). The oncologic results need further evaluation. Dynamic contrast enhanced MRI seems to be the best method for monitoring treatment response (77% sensitivity, 100% specificity). Ultrasound is suitable for guiding probes into the tumor. There is no consensus on the timing of the SNB.ConclusionsAll studies on minimally invasive ablative modalities published so far show that these techniques are feasible and safe. At this stage only T1 tumors should be ablated in a clinical trial setting; it is unclear which of the modalities is most suitable.