bluuebunny/crossref_metadata_2025 huggingface dataset:
Changing body temperature affects the T signal in the rat brain and reveals hypothalamic activity
Authors: Vanhoutte G. , Verhoye M. , Van der Linden A.
Published: April 2006

This study was designed to determine brain activity in the hypothalamus—in particular the thermoregulatory function of the hypothalamic preoptic area (PO). We experimentally changed the body temperature in rats within the physiological range (37–39°C) and monitored changes in blood oxygenation level‐dependent (BOLD) MR signal. To explore PO activity we had to deal with general signal changes caused by temperature‐dependent alterations in the affinity of oxygen for hemoglobin, which contributes to BOLD contrast because it is partly sensitive to the amount of paramagnetic deoxyhemoglobin in the voxel. To reduce these overall temperature‐induced effects, we corrected the BOLD data using brain‐specific correction algorithms. The results showed activity of the PO during body warming from 38°C to 39°C, supported by an increased BOLD signal after correction. This is the first fMRI study on the autonomous nervous system in which hypothalamic activity elicited by changes in the internal environment (body temperature) was monitored. In this study we also demonstrate 1) that any fMRI study of anesthetized small animals should guard against background BOLD signal drift, since animals are vulnerable to body temperature fluctuations; and 2) the existence of a link between PO activity and the sympathetically‐mediated opening of the arteriovenous anastomoses in a parallel study on the rat tail, a peripheral thermoregulatory organ. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Quantitative lung perfusion mapping at 0.2 T using FAIR True‐FISP MRI
Authors: Martirosian Petros , Boss Andreas , Fenchel Michael , Deimling Michael , Schäfer Jürgen , Claussen Claus D. , Schick Fritz
Published: April 2006

Perfusion measurements in lung tissue using arterial spin labeling (ASL) techniques are hampered by strong microscopic field gradients induced by susceptibility differences between the alveolar air and the lung parenchyma. A true fast imaging with steady precession (True‐FISP) sequence was adapted for applications in flow‐sensitive alternating inversion recovery (FAIR) lung perfusion imaging at 0.2 Tesla and 1.5 Tesla. Conditions of microscopic static field distribution were assessed in four healthy volunteers at both field strengths using multiecho gradient‐echo sequences. The full width at half maximum (FWHM) values of the frequency distribution for 180–277 Hz at 1.5 Tesla were more than threefold higher compared to 39–109 Hz at 0.2 Tesla. The influence of microscopic field inhomogeneities on the True‐FISP signal yield was simulated numerically. Conditions allowed for the development of a FAIR True‐FISP sequence for lung perfusion measurement at 0.2 Tesla, whereas at 1.5 Tesla microscopic field inhomogeneities appeared too distinct. Perfusion measurements of lung tissue were performed on eight healthy volunteers and two patients at 0.2 Tesla using the optimized FAIR True‐FISP sequence. The average perfusion rates in peripheral lung regions in transverse, sagittal, and coronal slices of the left/right lung were 418/400, 398/416, and 370/368 ml/100 g/min, respectively. This work suggests that FAIR True‐FISP sequences can be considered appropriate for noninvasive lung perfusion examinations at low field strength. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Continuously moving table 3D MRI with lateral frequency‐encoding direction
Authors: Aldefeld Bernd , Börnert Peter , Keupp Jochen
Published: April 2006

A method is presented for 3D MRI in an extended field of view (FOV) based on continuous motion of the patient table and an efficient acquisition scheme. A gradient‐echo MR pulse sequence is applied with lateral (left–right (L/R)) frequency‐encoding direction and slab selection along the direction of motion. Compensation for the table motion is achieved by a combination of slab tracking and data alignment in hybrid space. The method allows fast k‐space coverage to be achieved, especially when a short sampling FOV is chosen along the direction of table motion, as is desirable for good image quality. The method can be incorporated into different acquisitions schemes, including segmented k‐space scanning, which allows for contrast variation with the use of magnetization preparation. Head‐to‐toe images of volunteers were obtained with good quality using 3D spoiled gradient‐echo sequences. As an example of magnetization‐prepared imaging, fat/water separated images were acquired using chemical shift selective (CHESS) presaturation pulses. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Partial‐k‐space acquisition method for improved SNR efficiency and temporal resolution in 3D fMRI
Authors: Hu Y. , Glover G.H.
Published: April 2006

Previous studies have shown the relative importance of physiological noise and thermal noise in 2D MR images. Since physiological noise is proportional to the signal, it can be the dominant component at the center of k‐space. In this study we demonstrate that the signal‐to‐noise ratio (SNR) efficiency and temporal resolution for 3D functional MRI (fMRI) are increased by the use of a partial‐k‐space acquisition method. In partial‐k‐space methods, the high‐spatial‐frequency components are doubled in amplitude during reconstruction, resulting in twice as much noise from those components. However, in sum these contributions are relatively small compared to those at the low spatial frequencies, where physiological noise is dominant. Therefore, the effect on the final MR images is almost negligible due to the square summation rule. Thus, the partial‐k‐space 3D method sacrifices much less SNR than is expected from the thermal noise model, and the SNR efficiency is increased compared to a full‐k‐space acquisition since more time frames can be collected for the same scan time. Accordingly, the temporal resolution can be increased in 3D acquisitions because only partial coverage of k‐space is necessary. Experimental results confirm that more activation with a higher average t‐score is detected by this method. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Respiration‐induced B0field fluctuation compensation in balanced SSFP: Real‐time approach for transition‐band SSFP fMRI
Authors: Lee Jongho , Santos Juan M. , Conolly Steven M. , Miller Karla L. , Hargreaves Brian A. , Pauly John M.
Published: April 2006

In functional MRI (fMRI) the resonance frequency shift induced from respiration is a major source of physiological noise. In transition‐band SSFP fMRI the respiration‐induced resonance offset not only increases noise interference, it also shifts the activation band. This leads to a reduction in the contrast‐to‐noise ratio (CNR) and the potential for varying contrast levels during the experiment. A novel real‐time method that compensates for the respiration‐induced resonance offset frequency is presented. This method utilizes free induction decay (FID) phase information to measure the resonance offset. For compensation, one can update the resonant frequency in real time by changing the transmit RF pulse and receiver phases to track the measured offset. The results show decreased signal power in the respiration frequency band and increased numbers of activated voxels with higher Z‐scores compared to uncompensated experiments. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Simultaneous outer volume and blood suppression by quadruple inversion‐recovery
Authors: Yarnykh Vasily L. , Yuan Chun
Published: April 2006

A new method has been developed for reduced field‐of‐view (FOV) imaging with simultaneous blood suppression. This method combines suppression of signals from the outer volume and inflowing blood by using a small‐FOV quadruple inversion‐recovery (SFQIR) preparative pulse sequence consisting of two double‐inversion pulse pairs separated by appropriate delays. Within each pair, inversion pulses are successively applied to the imaged slice and the slab orthogonal to the imaging plane with the thickness equal to the FOV size in the phase‐encoding direction. Each double inversion results in the reinversion of the magnetization in the central part of the FOV, while the outer areas of the FOV and inflowing blood remain inverted. The SFQIR module was implemented for single‐ and multislice acquisition with a fast spin‐echo readout sequence. Based on a theoretical model of the signal, the timing parameters of the sequence corresponding to the maximal suppression efficiency can be found by minimizing the variation of the normalized signal over the entire range of T1's that occur in tissues. The method was tested for black‐blood imaging of the aorta and carotid arteries, and the results demonstrated its ability to eliminate motion and flow artifacts, reduce scan time, and improve spatial resolution. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Combo acquisitions: Balancing scan time reduction and image quality
Authors: Mekle Ralf , Wu Ed X. , Meckel Stephan , Wetzel Stephan G. , Scheffler Klaus
Published: April 2006

Recently a new technique for the combined acquisition of multicontrast images, termed “combo acquisition,” was introduced. In combo acquisitions, the three concepts of 1) variable acquisition parameters, 2) k‐space data sharing, and 3) multicontrast imaging are systematically integrated to reduce MRI scan time and improve data utilization in a clinical setting. In this study, two‐contrast and three‐contrast spin‐echo (SE) and turbo spin‐echo (TSE) combo acquisition protocols that were designed and optimized in simulation experiments were implemented on a 1.5 T clinical scanner. Phantom and human brain data from volunteers and patients were acquired. Scan time reductions of 25–52% were achieved compared to standard acquisitions, largely confirming the simulation results. We evaluated the resulting images by quantitatively analyzing the preservation of contrast and the signal‐to‐noise ratio (SNR). In addition, data sets for 10 clinical cases obtained with TSE combo and corresponding standard acquisitions were graded by two experienced neuroradiologists in terms of the level of artifacts and image quality for comparison. Only minor image degradation with the combo scans was observed, indicating an inherent trade‐off between scan time reduction and image quality. The specific aspects of combo acquisitions with respect to motion, flow, and k‐space data weighting are discussed. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Liposome‐enhanced MRI of neointimal lesions in the ApoE‐KO mouse
Authors: Mulder Willem J.M. , Douma Kim , Koning Gerben A. , van Zandvoort Marc A. , Lutgens Esther , Daemen Mat J. , Nicolay Klaas , Strijkers Gustav J.
Published: April 2006

Conventional high‐resolution MRI is capable of detecting lipid‐rich atherosclerotic plaques in both human atherosclerosis and animal models of atherosclerosis. In this study we induced neointimal lesions in ApoE‐KO mice by placing a constrictive collar around the right carotid artery. The model was imaged with conventional multispectral MRI, and the thickened wall could not be distinguished from surrounding tissue. We then tested paramagnetic liposomes (mean size = 90 nm) for their ability to improve MRI visualization of induced thickening, using Gd‐DTPA as a control. T1‐weighted (T1‐w), black‐blood MRI of the neck area of the mice was performed before and 15 min, 45 min, and 24 hr after intravenous injection of either paramagnetic liposomes or Gd‐DTPA. The collared vessel wall of mice that were injected with liposomes showed a pronounced signal enhancement of ∼100% immediately after injection, which was sustained largely until 24 hr postinjection. In contrast, the vessel wall of all controls (left carotid artery and animals injected with Gd‐DTPA) did not show significant contrast enhancement at those time points. This study demonstrates that intimal thickening in ApoE‐KO mice can be effectively detected by contrast‐enhanced (CE)‐MRI upon injection of paramagnetic liposomes. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Measurement of kinetic parameters in skeletal muscle by magnetic resonance imaging with an intravascular agent
Authors: Faranesh Anthony Z. , Kraitchman Dara L. , McVeigh Elliot R.
Published: April 2006

The purpose of this work was to investigate the use of an intravascular contrast agent to determine perfusion kinetics in skeletal muscle. A two‐compartment kinetic model was used to represent the flux of contrast agent between the intravascular space and extravascular extracellular space (EES). The relationship between the image signal‐to‐noise ratio (SNR) and errors in estimating permeability surface area product (Ktrans), interstitial volume (ve), and plasma volume (vp) for linear and nonlinear curve‐fitting methods was estimated from Monte Carlo simulations. Similar results were obtained for both methods. For an image SNR of 60, the estimated errors in these parameters were 10%, 22%, and 17%, respectively. In vivo experiments were conducted in rabbits to examine physiological differences between these parameters in the soleus (SOL) and tibialis anterior (TA) muscles in the hind limb. Values for Ktrans were significantly higher in the SOL (3.2 ± 0.9 vs. 2.0 ± 0.5 × 10–3 min–1), as were values for vp (3.4 ± 0.8 vs. 2.1 ± 0.7%). Differences in ve for the two muscles (8.7 ± 2.2 vs. 8.5 ± 1.6%) were not found to be significant. These results demonstrate that relevant physiological metrics can be calculated in skeletal muscle using MRI with an intravascular contrast agent. Magn Reson Med, 2006. Published 2006 Wiley‐Liss, Inc.
Toward quantitative short‐echo‐time in vivo proton MR spectroscopy without water suppression
Authors: Dong Zhengchao , Dreher Wolfgang , Leibfritz Dieter
Published: April 2006

A methodological development for quantitative short‐echo‐time (TE) in vivo proton MR spectroscopy (MRS) without water suppression (WS) is described that integrates experimental and software approaches. Experimental approaches were used to eliminate frequency modulation sidebands and first‐order phase errors. The dominant water signal was modeled and extracted by the matrix pencil method (MPM) and was used as an internal reference for absolute metabolite quantification. Spectral fitting was performed by combining the baseline characterization by a wavelet transform (WT)‐based technique and time‐domain (TD) parametric spectral analysis using full prior knowledge of the metabolite model spectra. The model spectra were obtained by spectral simulation instead of in vitro measurements. The performance of the methodology was evaluated by Monte Carlo (MC) studies, phantom measurements, and in vivo measurements on rat brains. More than 10 metabolites were quantified from spectra measured at TE = 20 ms on a 4.7 T system. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Selective and nonselective benzodiazepine agonists have different effects on motor cortex excitability
Authors: Mohammadi Bahram , Krampfl Klaus , Petri Susanne , Bogdanova Dessislava , Kossev Andon , Bufler Johannes , Dengler Reinhard
Published: April 2006

Transcranial magnetic stimulation (TMS) is a useful method to study pharmacological effects on motor cortex excitability. Zolpidem is a selective agonist of the benzodiazepine receptor subtype BZ1and has a distinct pharmacological profile compared to diazepam. To study the different effects of these two drugs on the cortical inhibitory system, TMS was performed before and after administration of a single oral dose of zolpidem (10 mg) and diazepam (5 mg) in six healthy volunteers. TMS tests included the determination of resting and active motor threshold (MT) and measurements of the amplitudes of motor evoked potentials, intracortical facilitation (ICF), short‐latency intracortical inhibition (SICI), and long‐latency intracortical inhibition (LICI), and determination of the cortical silent period (CSP). Both drugs were without effect on the active or resting MT and decreased the ICF. Prolongation of the CSP and enhancement of LICI only in the presence of zolpidem point to a specific BZ1‐related mechanism underlying the long‐lasting component of cortical inhibition. This selective modulation of the CSP and the LICI points to a specific role of BZ1receptors in the control of inhibitory neuronal loops within the primary motor cortex. Muscle Nerve, 2006
Fully sequential indifference‐zone selection procedures with variance‐dependent sampling
Authors: Jeff Hong L.
Published: April 2006

Fully sequential indifference‐zone selection procedures have been proposed in the simulation literature to select the system with the best mean performance from a group of simulated systems. However, the existing sequential indifference‐zone procedures allocate an equal number of samples to the two systems in comparison even if their variances are drastically different. In this paper we propose new fully sequential indifference‐zone procedures that allocate samples according to the variances. We show that the procedures work better than several existing sequential indifference‐zone procedures when variances of the systems are different. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
On‐line parameter estimation for a partially observable system subject to random failure
Authors: Lin Daming , Makis Viliam
Published: April 2006

In this paper, we study the on‐line parameter estimation problem for a partially observable system subject to deterioration and random failure. The state of the system evolves according to a continuous time homogeneous Markov process with a finite state space. The system state is not observable, except for the failure state. The information related to the system state is available at discrete times through inspections. A recursive maximum likelihood (RML) algorithm is proposed for the on‐line parameter estimation of the model. The RML algorithm proposed in the paper is considerably faster and easier to apply than other RML algorithms in the literature, because it does not require projection into the constraint domain and calculation of the gradient on the surface of the constraint manifolds. The algorithm is illustrated by an example using real vibration data. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Late effects risk profiles using the long‐term follow‐up guidelines in Identical Twin Survivors of Acute Lymphoblastic Leukemia1
Authors: Howell Della L. , Lew Glen , Comeaux Laura G. , Meacham Lillian R.
Published: April 2006

As the number of pediatric cancer survivors increases, the cost of cure (i.e., late effects) needs to be measured through a consistent mechanism. Through the use of the Children's Oncology Group's (COG) Long‐Term Follow‐Up (LTFU) guidelines, individualized risk profiles can be discerned for each off‐therapy patient. These guidelines were used to compare and contrast risk profiles for identical twin females treated for acute lymphoblastic leukemia (ALL). The first twin was treated for high‐risk leukemia and the second for standard‐risk leukemia, each with different ALL protocols. Timely use of the LTFU guidelines has aided in identifying and treating their adverse late effects. Pediatr Blood Cancer 2007;49:349–352. © 2006 Wiley‐Liss, Inc.
Ceftriaxone induced hemolysis complicated by acute renal failure
Authors: Kapur Gaurav , Valentini Rudolph P. , Mattoo Tej K. , Warrier Indira , Imam Abubakr A.
Published: April 2006

Over the last decade, second and third generation cephalosporins have been the most common drugs causing hemolytic anemia (HA). Of these cases, 20% have been attributed to ceftriaxone. The clinical presentation of ceftriaxone‐induced HA is usually abrupt with sudden onset of pallor, tachypnea, cardio‐respiratory arrest and shock. Acute renal failure (ARF) has been reported in 41% of such cases with a high fatality rate. We report a pediatric patient with ARF complicating ceftriaxone‐induced HA who survived. Ceftriaxone is a commonly used drug, and early recognition of HA and institution of supportive care, including dialysis is likely to improve the outcome. Pediatr Blood Cancer 2008;50:139–142. © 2006 Wiley‐Liss, Inc.
QCT versus DXA in 320 survivors of childhood cancer: Association of BMD with fracture history
Authors: Kaste Sue C. , Tong Xin , Hendrick Jennifer M. , Karimova Evguenia J. , Srivastava Deo Kumar , Tylavsky Frances A. , Snider Terry L. , Carbone Laura D.
Published: April 2006

Purpose

To assess agreement on diagnosis of diminished bone mineral density (BMD) and correlation between BMD values obtained by dual‐energy X‐ray absorptiometry (DXA) and quantitative computed tomography (QCT) in childhood cancer survivors.

Patients and Methods

We retrospectively reviewed lumbar spine QCT and DXA studies for BMD in patients who underwent both imaging studies within a 24‐hr period. We determined correlation between BMD values and agreement on diagnosis of diminished BMD obtained by both modalities. Diminished BMD was defined as two or more SDs below mean for age‐ and gender‐matched reference values. We evaluated the relationship of BMD values determined by each modality to self‐reported fracture history in the 160 (50%) patients with available reports.

Results

Of 320 patients, 56% (178) were male; 87% (277) were white. Median age was 16.4 (range, 5.1–36.0) years. Median BMD Z‐score was −1.43 (range, −5.96 to 3.20) by QCT and −1.30 (range, −5.50 to 2.80) by DXA. Correlation between QCT‐ and DXA‐determined BMD values was significant but low, and agreement on diminished BMD was fair (κ = 0.32). There was no association between BMD measured by either QCT or DXA and self‐reported traumatic fracture history. Male gender was associated with doubling the traumatic fracture risk (P = 0.0499).

Conclusions

Quantitative computed tomography and DXA may give discrepant results when used to assess bone health in childhood cancer survivors, especially in those of non‐white race. This inconsistency in indicators of BMD deficiency may complicate clinical decision‐making. Consecutive use of a single modality is recommended to provide reliable longitudinal information. © 2006 Wiley‐Liss, Inc.
Interview of patients by pharmacists contributes significantly to the identification of drug‐related problems (DRPs)
Authors: Viktil Kirsten K. , Blix Hege Salvesen , Moger Tron A , Reikvam Aasmund
Published: April 2006

Purpose

To investigate whether pharmacist interviews of hospitalised patients about their medication would result in identification of more drug‐related problems (DRPs) than those found by usual care procedures and further to characterise the DRPs revealed at the interviews.

Methods

Patients from five internal medicine and two rheumatology departments in four hospitals in Norway were prospectively included in the study. Clinical pharmacists assessed DRPs by reviewing medical records and by participating in multidisciplinary team discussions. Drugs used, medical history, laboratory data and clinical/pharmacological risk factors were recorded (usual care procedure). A proportion of patients were randomly selected for interview with pharmacists. A quality team assessed the clinical significance of the DRPs.

Results

Seven hundred and twenty seven patients were included. Significantly more DRPs were found in the interview group (96 patients), an average of 4.4 DRPs per patient as compared to 2.4 DRPs in the non‐interview group (631 patients) (p < 0.01). Of a total of 431 DRPs recorded in the interview group, 168 DRPs (39.9%) were disclosed through interviews. ‘Need for additional drug’, ‘medical chart error’, ‘patient adherence’ and ‘need for patient education’ were significantly more often recorded in this group. The quality team assessed 63% of the DRPs revealed in the interviews to be of major clinical significance.

Conclusion

Significantly more DRPs were identified among the patients who were interviewed compared to those patients having only usual care examination. A high proportion of the DRPs identified in the interviews were of major clinical significance. The clinical pharmacists, with their way of interviewing, seem to fill a gap, ensuring that significant DRPs do not escape detection. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of epoxy resin‐modified zinc‐ion‐coated nanosilica on structural, thermal and dynamic mechanical properties of propylene‐ethylene copolymer
Authors: Reddy Chaganti Srinivasa , Das Chapal Kumar
Published: April 2006

This paper reports a comparative study of propylene–ethylene copolymer (EP) nanocomposites synthesized using zinc‐ion (Zn2+)‐coated nanosilica (ZNS) and the diglycidyl ether of bisphenol‐A (DGEBA, an epoxy resin)‐modified zinc‐ion‐coated nanosilica (EZNS) as nanofillers. These nanocomposites were prepared using the ‘melt mixing’ method at a constant loading level of 2.5 wt%. This loading level is much lower than that used for fillers in conventional composites. The EP nanocomposites were characterized using wide‐angle X‐ray diffractometer (WAXD), a thermo gravimetric analyzer (TGA), a differential scanning calorimeter (DSC), a dynamic mechanical analyzer (DMA) and scanning electron microscopy (SEM). DMA results showed a higher storage modulus for EP‐epoxy‐modified Zn2+‐coated nanosilica nanocomposite (EP‐EZNS) with respect to EP and EP‐Zn2+‐coated nanosilica nanocomposite (EP‐ZNS). In addition, TGA thermograms showed an increase in degradation temperature of EP in the presence of EZNS. Copyright © 2006 Society of Chemical Industry
Dendrimers based on [1,3,5]‐triazines
Authors: Steffensen Mackay B. , Hollink Emily , Kuschel Frank , Bauer Monika , Simanek Eric E.
Published: April 2006

A comprehensive and chronological account of dendrimers based on [1,3,5]‐triazines is provided. Synthetic strategies to install the triazine through cycloaddition, cyclotrimerization, and nucleophilic aromatic substitution of cyanuric chloride are discussed. Motivations and applications of these architectures are surveyed, including the preparation of supramolecular assemblies in the solution and solid states and their use in medicines, advanced materials, and separations when anchored to solid supports. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3411–3433, 2006
Synthesis, characterization, and proton‐conducting properties of organic–inorganic hybrid membranes based on polysiloxane zwitterionomer
Authors: Liang Wuu‐Jyh , Wu Chien‐Pang , Hsu Chang‐Yu , Kuo Ping‐Lin
Published: April 2006

The synthesis and characterization of a series of zwitterionic hybrid membranes based on a zwitterionic siloxane precursor (ZS) are described. Flexible, transparent, optically homogeneous films were prepared. With the further incorporation of poly(ethylene glycol) (PEG), the hybrid films became more flexible but translucent. The structure of the inorganic sides was probed with solid‐state 29Si NMR spectroscopy, and the organic sides and the chemical process involved were characterized with solid‐state 13C cross‐polarization/magic‐angle spinning NMR. A higher content of ZS led to higher proton conductivity of the hybrid electrolytes. Moreover, the proton conductivity was enhanced by the addition of the plasticizing component of PEG to the hybrid matrix; this was ascribed to the increased water uptake and free volume of the hybrid matrix and the dissociation of sulfonic acid groups. The proton conductivity of these hybrid membranes could be increased up to 3.5 × 10−2 S/cm by the temperature and relative humidity being increased to 85 °C and 95%, respectively. The proton‐conduction behavior of these hybrid membranes is also briefly discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3444–3453, 2006
Atom transfer radical polymerization directly from poly(vinylidene fluoride): Surface and antifouling properties
Authors: Chen Yiwang , Liu Dongmei , Deng Qilan , He Xiaohui , Wang Xiaofeng
Published: April 2006

The direct preparation of grafting polymer brushes from commercial poly (vinylidene fluoride) (PVDF) films with surface‐initiated atom transfer radical polymerization (ATRP) is demonstrated. The direct initiation of the secondary fluorinated site of PVDF facilitated grafting of the hydrophilic monomers from the PVDF surface. Homopolymer brushes of 2‐(N,N‐dimethylamino)ethyl methacrylate (DMAEMA) and poly (ethylene glycol) monomethacrylate (PEGMA) were prepared by ATRP from the PVDF surface. The chemical composition and surface topography of the graft‐functionalized PVDF surfaces were characterized by X‐ray photoelectron spectroscopy, attenuated total reflectance/Fourier transform infrared spectroscopy, and atomic force microscopy. A kinetic study revealed a linear increase in the graft concentration of poly[2‐(N,N‐dimethylamino)ethyl methacrylate] (PDMAEMA) and poly[poly(ethylene glycol) monomethacrylate] (PPEGMA) with the reaction time, indicating that the chain growth from the surface was consistent with a controlled or living process. The living chain ends were used as macroinitiators for the synthesis of diblock copolymer brushes. The water contact angles on PVDF films were reduced by the surface grafting of DMAEMA and PEGMA. Protein adsorption experiments revealed a substantial antifouling property of PPEGMA‐grafted PVDF films and PDMAEMA‐grafted PVDF films in comparison with the pristine PVDF surface. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3434–3443, 2006
A qualitative study of factors affecting chemotherapy use in older women with breast cancer: barriers, promoters, and implications for intervention
Authors: Kreling Barbara , Figueiredo Melissa I. , Sheppard Vanessa L. , Mandelblatt Jeanne S.
Published: April 2006

Study objective: The incidence of breast cancer increases with advancing age and yet women 65 and older (hereinafter referred to as ‘older’ women) do not always receive the most intensive treatments, such as adjuvant chemotherapy. The causes of underutilization of chemotherapy in this age group are poorly delineated. The purpose of the study was to explore older breast cancer patients' attitudes towards chemotherapy and factors that influenced their decisions to use or not use this treatment modality.

Design: Qualitative methods were used to conduct race/ethnicity‐specific focus groups. A thematic analysis was performed using NVIVO.

Setting and Participants: Drawn from the Washington, DC area, participants were 34 ethnically diverse older breast cancer survivors (18 Caucasians, 10 African‐Americans, and 6 Latinas). Focus groups were conducted in a local church; a senior center, and the Lombardi Cancer Center.

Main Results: Results showed that many women felt they had no ‘choice’ and did what the doctor told them to do. For those who reported participation in the decision, time spent exchanging information with the woman's physician and the inclusion of family members promoted perceptions of optimum decision‐making leading to the use of chemotherapy. Two barriers to using chemotherapy were negative expectations about side effects and lack of information specific to the woman's individuals' circumstances. Women of color reported less physician communication and information, in part due to language difficulties and perceived bias; these factors acted as barriers to chemotherapy.

Conclusion: Physicians could provide specific and limited information to patients and family members to promote realistic expectations and optimum decisions about chemotherapy, given the risks involved in this treatment modality. Interventions should be developed and tested to enhance communication that is sensitive to older women's culture, family structure, illness experiences, preferences, and expectations. Copyright © 2006 John Wiley & Sons, Ltd.
Appraisals and coping in people living with cancer: a meta‐analysis
Authors: Franks Heather M. , Roesch Scott C.
Published: April 2006

The present meta‐analysis examined the relationship between primary appraisal dimensions and coping strategies in people with cancer. Primary appraisals were operationalized as appraisals of threat, challenge, and harm/loss. Coping was operationalized according to two coping taxonomies: the first based on coping efforts to manage the stressor itself and/or the distressful feelings associated with it (problem‐ or emotion‐focused coping, respectively) and the second based on the general orientation of the coping efforts (approach or avoidance coping). Appraisals of threat were (counter‐intuitively) related to use of problem‐focused coping (r=0.20); appraisals of harm and/or loss were related to avoidance coping (r=0.23); and appraisals of challenge were related to both problem‐focused (r=0.15) and approach coping (r=0.14). These findings suggest that individuals with cancer who appraise their illness as a threat are likely to use more problem‐focused coping strategies. Individuals who appraise their cancer as a harm/loss, however, are likely to use more avoidance coping strategies. And finally, those who appraise their cancer as a challenge are likely to use approach coping strategies. Factors found to moderate the relationship between appraisals and coping included age of the participant, time since diagnosis, and type of cancer. Copyright © 2006 John Wiley & Sons, Ltd.
Metrafenone: studies on the mode of action of a novel cereal powdery mildew fungicide
Authors: Opalski Krystina S , Tresch Stefan , Kogel Karl‐Heinz , Grossmann Klaus , Köhle Harald , Hückelhoven Ralph
Published: April 2006

Powdery mildew fungi are among the major pathogens causing diseases of cereals in the world. The mode of action of a novel systemic benzophenone fungicide, metrafenone, which is based on a precursor that is discussed in the preceding paper, has been analysed on the powdery mildew fungi of barley (Blumeria graminis Speer f. sp. hordei Marchal) and wheat (Blumeria graminis Speer f. sp. tritici Marchal). Preventive treatments reduced germination and blocked development beyond formation of appressoria, which penetrated less often. Moreover, metrafenone turned out to be an efficient curative fungicide, which rapidly affected fungal survival at low concentrations. The fungicide induced swelling, bursting and collapse of hyphal tips, resulting in the release of globules of cytoplasm. Bifurcation of hyphal tips, secondary appressoria and hyperbranching were also frequently observed. A histochemical analysis showed that metrafenone caused disruption of the apical actin cap and apical vesicle transport as well as weakening of the cell wall at hyphal tips. Finally, metrafenone strongly reduced sporulation. Reduced sporulation was associated with malformation of conidiophores that showed irregular septation, multinucleate cells and delocalisation of actin. Microtubules appeared to be only secondarily affected in metrafenone‐treated B. graminis. The results suggest that the mode of action of metrafenone interferes with hyphal morphogenesis, polarised hyphal growth and the establishment and maintenance of cell polarity. Metrafenone likely disturbs a pathway regulating organisation of the actin cytoskeleton. Copyright © 2006 Society of Chemical Industry
Persistence and efficacy of two diatomaceous earth formulations and a mixture of diatomaceous earth with natural pyrethrum against Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) on wheat and maize
Authors: Vayias Basileios J , Athanassiou Christos G , Kavallieratos Nickolas G , Tsesmeli Catherine D , Th Buchelos Constantin
Published: April 2006

Laboratory tests were conducted to assess the insecticidal and residual effects of three diatomaceous earth (DE) formulations, Insecto®, PyriSec® and SilicoSec®, against Tribolium confusum Jacquelin du Val on wheat and maize. Quantities of wheat and maize were treated with the above formulations at 500, 1000 and 1500 mg kg−1 and stored at 25 °C and 55% relative humidity (RH). Samples were taken on the day of storage and every 30 days until completion of a 360 day period of storage. Adults of T. confusum were exposed to these samples at 25 °C and 55% RH and the mortality was measured after 24 and 48 h and 7 and 14 days of exposure. Adult mortality was higher on wheat than on maize. At the beginning of the storage period, mortalities after 14 day exposure on maize treated with the highest rate were 60, 63 and 81% for Insecto®, PyriSec® and SilicoSec® respectively, while on wheat the mortality was 100% for all DEs. On the same commodities 360 days after treatment the respective mortality figures for wheat were 99, 98 and 100%, while in the case of maize they did not exceed 7%. Generally, mortality at exposures ≤48 h decreased with increasing storage time. Furthermore, although mortality on wheat increased with dose, the increase in DE dose from 1000 to 1500 mg kg−1 resulted in only a small increase in mortality. Thus a DE treatment of 1000 mg kg−1 was shown to provide long‐term protection of wheat against T. confusum, although higher DE application rates and exposure intervals are needed for a satisfactory level of protection of maize against this pest. Copyright © 2006 Society of Chemical Industry
A study on the molecular mechanism of resistance to amicarthiazol in Xanthomonas campestris pv. citri
Authors: Li Jun , Zhou Mingguo , Li Hongxia , Chen Changjun , Wang Jianxing , Zhang Yujun
Published: April 2006

Three amicarthiazol‐resistant mutants (Xuv10, Xuv20 and Xuv40) were obtained by UV induction and used in this study. Minimal inhibition concentrations (MICs) of amicarthiazol against the growth of mutants and wild‐type isolate were 400 and 100 µg ml−1 respectively. Inhibition by amicarthiazol of succinate dehydrogenase (SDH) activities of Xanthomonas campestris pv. citri (Hasse) Dye wild‐type isolate (Xcc) and three resistant mutants derived from this isolate were assayed using triphenyltetrazolium chloride (TTC). The SDH activities of these mutants were significantly lower than that of Xcc. The complete nucleotide sequences of four subunits (SdhA, SdhB, SdhC and SdhD) of succinate‐ubiquinone oxidoreductase (SQR) were cloned by polymerase chain reaction (PCR) amplification. An amino acid mutation (His229→ Leu229) in sdhB was found to confer resistance of X. campestris pv. citri to amicarthiazol. It is suggested that this mutation alters the SDH complex in some way that prevents binding of amicarthiazol. Copyright © 2006 Society of Chemical Industry
The effects of kaolin particle film on Plutella xylostella behaviour and development
Authors: Barker Jenny E , Fulton Alison , Evans K Andrew , Powell Glen
Published: April 2006

Studies were conducted to evaluate the effect of a kaolin‐based particle film against the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). The effect of the particle film on development, survival and host plant selection was tested on calabrese seedlings, Brassica oleracea italica Plenck cv. Fiesta F1, under controlled environmental conditions in the laboratory. Survival to adulthood was significantly reduced and development time increased on kaolin‐treated compared with water‐treated host plants. The hatch rate of neonate P. xylostella larvae from eggs laid on an artificial substrate was unaffected by the particle film applied after oviposition. Experiments showed that, when given the choice, significantly fewer larvae first made contact with the kaolin‐treated compared with the water‐treated plant material and that after 24 h there were still significantly fewer larvae present on kaolin‐treated leaves. Adult females, however, deposited more eggs on host plants coated with the kaolin particle film. As part of this series of experiments the water control treatment was compared with plant material which had been sprayed with kaolin on the upper surface only and on both leaf surfaces. In general, any observed treatment effect was enhanced with an increase in the particle film coverage. The results warrant the extension of investigations of kaolin‐based particle films to field‐based P. xylostella management strategies. Copyright © 2006 Society of Chemical Industry
Study on optical properties of La3Ga5SiO14 crystals by interferometry of polarized light
Authors: Qi Haifeng , Wei Aijian , Wang Qingpu , Yuan Duorong
Published: April 2006

The birefringence and optical activity of La3Ga5SiO14 crystal were studied by interferometry of polarized light. The corresponding characteristic parameters were calculated from the transmittance spectra with different orientational configuration between parallel polarisers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Focusing slabs made of negative index materials based on inhomogeneous dielectric rods
Authors: Sergentu V. V. , Ursaki V. V. , Tiginyanu I. M. , Foca E. , Föll H. , Boyd Robert W.
Published: April 2006

We show the advantages of using inhomogeneous dielectric rods to design photonic crystals that behave as materials with negative refractive index. We found that the analysis of light scattering properties of inhomogeneous dielectric rods allows one to estimate the interval of frequencies where a photonic crystal exhibits negative refractive index. A triangular‐lattice photonic crystal – assembled from multilayer dielectric rods designed to approximate a fish‐eye profile – is shown to exhibit negative refractive index and good focusing properties at frequencies where the fish‐eye dielectric rods scatter the light like a medium with negative refractive index. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Process Optimization via Robust Parameter Design when Categorical Noise Factors are Present
Authors: Robinson Timothy J. , Brenneman William A. , Myers William R.
Published: April 2006

When categorical noise variables are present in the Robust Parameter Design (RPD) context, it is possible to reduce process variance by not only manipulating the levels of the control factors but also by adjusting the proportions associated with the levels of the categorical noise factor(s). When no adjustment factors exist or when the adjustment factors are unable to bring the process mean close to target, a popular approach for determining optimal operating conditions is to find the levels of the control factors that minimize the estimated mean squared error of the response. Although this approach is effective, engineers may have a difficult time translating mean squared error into quality. We propose the use of a parts per million defective objective function. Furthermore, we point out that in many situations the levels of the control factors are not equally desirable due to cost and/or time issues. We have termed these types factors non‐uniform control factors. We propose the use of desirability functions to determine optimal operating conditions when non‐uniform control factors are present and illustrate this methodology with an example from industry. Copyright © 2006 John Wiley & Sons, Ltd.
A QSAR Study of Avian Oral Toxicity using Support Vector Machines and Genetic Algorithms
Authors: Mazzatorta Paolo , Cronin Mark T. D. , Benfenati Emilio
Published: April 2006

This paper presents a study conducted on 116 pesticides to investigate the underlying relationship between structural properties and avian oral toxicity. Data were collected from several sources and screened to ensure quality and consistency. Physico‐chemical and structural descriptors were obtained for the pesticides using the OpenMolGRID system. The resulting dataset was mined using principal component analysis (PCA), genetic algorithms (GA) and other classification algorithms. The final model was obtained using a support vector machine (SVM) combined with genetic algorithms for feature selection. It has good predictive ability (the error rate of the training set=0.021, the error rate of the validation set=0.158). Analysis of the descriptors indicates the prominent role of the interaction of pesticides with macromolecules and/or proteins in the mechanism of action.
Aromaticity‐induced changes in electronic properties of size‐expanded DNA bases: Case of xC
Authors: Fuentes‐Cabrera Miguel , Lipkowski Pawel , Huertas Oscar , Sumpter Bobby G. , Orozco Modesto , Luque F. Javier , Wells Jack C. , Leszczynski Jerzy
Published: April 2006

Size‐expanded DNA bases are analogues of natural bases that can be described as a synthesis between benzene and a natural base. Size‐expanded bases have been combined with natural bases to form xDNA and yDNA, a new class of synthetic nucleic acids. We are interested in xDNA and yDNA because they might function as molecular wires. Recently, we also became intrigued by the possibility of altering the electronic conductivity of xDNA and yDNA by means of structural changes in the constituent bases. This possibility appeared after we noticed that the highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gap of the base yG can be increased dramatically, ∼0.73 eV, by changing the aromaticity of its benzene ring. Therefore, if one is able to alter the HOMO–LUMO gap of size‐expanded bases, it should be possible to change the electronic conductivity of xDNAs and yDNAs as well. In the present work, we extend our study on aromaticity‐induced changes on the electronic properties of size‐expanded bases by investigating the HOMO–LUMO gap of all possible tautomers of xC. We have found that, as for yG, the HOMO–LUMO gap of xC can be modified by ∼ 0.74 eV, and that this can be accomplished by changing the aromaticity of its benzene ring. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Long‐term outcome and neuroradiological findings of 31 patients with 6‐pyruvoyltetrahydropterin synthase deficiency
Authors: Wang L. , Yu W.‐M. , He C. , Chang M. , Shen M. , Zhou Z. , Zhang Z. , Shen S. , Liu T.‐T. , Hsiao K.‐J.
Published: April 2006

Tetrahydrobiopterin (BH4) deficiency is an autosomal recessive disorder caused by enzyme defects in the biosynthesis or recycling of BH4. Patients with BH4 deficiency present with severe neurological signs and symptoms and .require a different treatment from classical phenylketonuria. During the last 12 years, 31 cases of BH4 deficiency were identified in our department. They were all classified as 6‐pyruvoyl‐tetrahydropterin synthase (PTPS) deficiency. They were diagnosed at the ages of 2.5–48 months and treated with BH4, L‐dopa and 5‐hydroxytryptophan immediately after diagnosis. The average development quotients (DQ) at diagnosis and after treatment for more than 3 years were 53± 16, and 78± 15, respectively. A significant negative correlation was observed between the level of the DQ and the age at which treatment was commenced (r = −0.751, p = 0.002). Developmental profiles were uneven. Language, adaptability and at later age mathematics were particularly weak areas. Only two patients achieved a good performance in mathematics. Eleven patients who were treated with drugs from ages of 2.9–48 months had neuroradiological scanning. Computed tomography disclosed calcification in lentiform nuclei in one patient and magnetic resonance imaging disclosed delayed myelination and abnormal high intensity signal in cerebral white matter in all of them. Even though most of abnormalities were reversible, small patchy or spotted areas were still present on these regions after treatment for 10–46 months. In summary, our study supports the substantial efficacy of the current therapeutic approach in PTPS deficiency of normalizing amine neurotransmitters with three drugs as early as possible. For the first time, calcifications could be detected in patients with PTPS deficiency. Abnormalities in white matter on magnetic resonance imaging were not related to clinical manifestations and most were reversible.
Severe normotensive metabolic alkalosis in a 2‐month‐old boy with hyperekplexia
Authors: Schlapbach L. J. , Sozzo A. , Ramelli G. , Bianchetti M. G.
Published: April 2006

A 2‐month‐old infant with hereditary hyperekplexia, umbilical and bilateral inguinal hernias and history of poor feeding was noted to have severe normotensive metabolic alkalosis: sodium 132 mmol/L, potassium 3.4 mmol/L, chloride 77 mmol/L, pH 7.55, carbon dioxide tension 56.3 mmHg and bicarbonate 48.0 mmol/L. After parenteral rehydration and treatment with clonazepam, laboratory parameters normalized.