bluuebunny/crossref_metadata_2025 huggingface dataset:
Human influenza virus infection and apoptosis induction in human vascular endothelial cells
Authors: Sumikoshi Makoto , Hashimoto Koichi , Kawasaki Yukihiko , Sakuma Hiroko , Suzutani Tatsuo , Suzuki Hitoshi , Hosoya Mitsuaki
Published: April 2008

Acute encephalopathy accompanying influenza virus infection results in brain and systemic organ failure mainly through vasogenic edema with high levels of inflammatory cytokines, such as blood tumor necrosis factor (TNF)‐α and interleukin (IL)‐6, as well as the cytochrome c apoptosis marker. A highly virulent strain of avian influenza virus causes fatal infection in chickens by infecting vascular endothelial cells in systemic organs, inducing apoptosis therein. To verify the possibility of apoptosis induction by human influenza virus in infected human vascular endothelial cells, purified influenza virus‐infected human umbilical vein endothelial cells (HUVECs) were examined using a tissue culture method. When pre‐treated with TNF‐α, influenza virus (Philippine strain, H3N2) promoted TNF‐α induced apoptosis of HUVECs. Viral replication was confirmed in HUVECs infected with the Philippine strain in the absence of TNF‐α by measurement of the amount of infective virus in the culture supernatant using the tissue culture infectious dose (TCID) method, immunohistochemistry and real‐time PCR. The number of influenza virus genomes in the infected HUVECs at 24 hr post‐infection increased about fivefold compared to that just after virus adsorption. Many TUNEL‐positive influenza virus‐infected HUVECs were observed using the TUNEL method. Furthermore, cleaved caspase 3 was also detected in influenza virus‐infected cells by immunofluorescence staining. These results demonstrated that human influenza virus can infect and replicate in human vascular endothelial cells and induce apoptosis therein. J. Med. Virol. 80:1072–1078, 2008. © 2008 Wiley‐Liss, Inc.
Lack of protein expression of the simian virus 40 large T antigen in human lymphomas
Authors: Went Philip , Seemayer Christian A. , Pileri Stefano , Maurer Robert , Tzankov Alexandar , Dirnhofer Stephan
Published: April 2008

Several studies have detected Simian virus 40 (SV40) deoxyribonucleic acid sequences in human tumor tissues, including lymphomas, mainly by the polymerase chain reaction, but these data were not confirmed by subsequent investigations. Regional differences in the distribution of the SV40 and/or technical difficulties have been taken into account to explain these divergent results, but because only a few such studies dealt with the expression of SV40 proteins in tumor tissues, we investigated the expression of the SV40 large T antigen in human lymphomas by immunohistochemistry. Tissue microarrays containing Non‐Hodgkin's‐lymphomas and Hodgkin's‐lymphomas were constructed utilizing archival samples encompassing the years 1974–2001 from Italian, Swiss and Austrian patients. Expression of the SV40 large T antigen was analysed by highly specific and sensitive immunohistochemistry using a mouse monoclonal antibody. Protein expression of the large T antigen was not detected in 655 Non‐Hodgkin's‐lymphomas or in 337 Hodgkin's‐ lymphomas. The results suggest the absence of an association between SV40 large T antigen and human lymphomas. J. Med. Virol. 80:1112–1115, 2008. © 2008 Wiley‐Liss, Inc.
Potential of HILIC‐MS in quantitative bioanalysis of drugs and drug metabolites
Authors: Hsieh Yunsheng
Published: April 2008

One fundamental requirement for many lead optimization processes is the need for bioanalytical support within pharmaceutical drug discovery and development. Currently, most bioanalytical methods for pharmaceutical analysis employ HPLC coupled with MS/MS. The combination of HPLC and MS/MS detection frequently offers the complete resolution of the dosed compounds from their metabolites and the endogenous interferences to avoid extra efforts for chemical separation and sample clean‐up procedures resulting in higher‐throughput assays for a series of new chemical entities (NCEs). Hydrophilic interaction chromatography (HILIC) has been demonstrated to be a powerful technique for the retention of polar analytes offering a difference in selectivity compared to traditional RP chromatography. This review summarizes the HILIC‐MS/MS methods for the trace quantitative determinations of the drug compounds and their metabolites to support both in vitro and in vivo experiments. The challenges on performing HILIC‐MS/MS assays such as matrix ionization suppression and the potential for endogenous interferences are also presented.
Evaluation of hydrophilic interaction chromatography versus reversed‐phase chromatography in a plant metabolomics perspective
Authors: t'Kindt Ruben , Storme Michael , Deforce Dieter , Van Bocxlaer Jan
Published: April 2008

The metabolomics goal, the unbiased relative quantification of all metabolites in a biological system, still lacks a universal analytical approach. In the LC‐MS line of approach, one of the major problems encountered is the polar nature of a large group of (plant) metabolites. Here, we investigate the potential of hydrophilic interaction chromatography (HILIC) and compare its qualities with extended polarity RP chromatography. Two opposite LC phase compositions (Atlantis dC18 vs. TSKgel Amide‐80) are compared in a plant metabolomics setting. Both performed equally well with regard to retentive capacities, but variation in peak area was about 5% higher for the HILIC approach. Focussing on matrix effects (ME) on the other hand, it was observed that this well‐known problem in RP LC‐MS metabolomics was not reduced on using hydrophilic interaction chromatography.
Development of retention prediction models for adrenoreceptor agonists and antagonists on a polyvinyl alcohol‐bonded stationary phase in hydrophilic interaction chromatography
Authors: Quiming Noel S. , Denola Nerissa L. , Samsuri Shahril Reza Bin , Saito Yoshihiro , Jinno Kiyokatsu
Published: April 2008

Retention prediction models based on multiple linear regression (MLR) and artificial neural network (ANN) for adrenoreceptor agonists and antagonists chromatographed on a polyvinyl alcohol‐bonded stationary phase under hydrophilic interaction chromatography were described. The models showed the combined effects of solute structure and mobile phase composition on the retention behavior of the analytes. Using stepwise MLR, the retentions of the studied compounds were satisfactorily described by a five‐predictor model; the predictors being the %ACN, the logarithm of the partition coefficient (log D), the number of hydrogen bond donors (HBD), the desolvation energy for octanol (FOct), and the total absolute atomic charge (TAAC). The inclusion of the solute‐related descriptors suggested that hydrophilic interactions such as hydrogen bonding and also ionic interactions are possible mechanisms by which analytes are retained on the studied system. ANN prediction models were also derived using the predictors derived from MLR as inputs and log k as outputs. The best network architectures were found to be 5‐3‐1 for the datasets at pH 3.0 and 4.0, and 5‐4‐1 for the dataset at pH 5.0. The optimized ANNs showed better predictive properties than the MLR models for both training and test sets under all pH conditions.
The application of novel 1.7 μm ethylene bridged hybrid particles for hydrophilic interaction chromatography
Authors: Grumbach Eric S. , Diehl Diane M. , Neue Uwe D.
Published: April 2008

An un‐derivatized 1.7 μm ethylene bridged hybrid (BEH) particle was evaluated for its utility in retaining polar species in hydrophilic interaction chromatography (HILIC), and was compared to a 3 μm un‐derivatized silica material. Retentivity as a function of mobile phase pH, polar modifier and ACN content was examined. Also, the efficiency of the two particle substrates was compared by plotting HETP vs. linear velocity. Improved chemical resistance of the un‐derivatized BEH particle was compared to un‐derivatized silica at pH 5, demonstrating no performance deterioration over the course of 2000 injections for the BEH particle, while the silica particle deteriorated rapidly after 800 injections. Lastly, ESI‐MS sensitivity as a function of particle size and separation mode was demonstrated. A 2.2 to 4.7‐times higher ESI‐MS response was observed on the 1.7 μm particle compared to the 3 μm particle, whereas a 5.6 to 8.8‐times higher ESI‐MS response was observed using HILIC as when compared to traditional RP chromatography.
Design of GRIN optical components for coupling and interconnects
Authors: Gomez‐Reino C. , Perez M.V. , Bao C. , Flores‐Arias M.T.
Published: April 2008

This paper reviews the design of some optical systems for coupling and interconnection by GRIN components. The optical systems designed with these components are based on imaging and transforming properties of such components to carry out specific functions. First of all, a brief description of light propagation through GRIN materials will be given. After that, a device to couple light by a GRIN fiber lens into fibers of different core sizes with low loss is described. The coupling efficiency as well as the coupling loss are studied versus variation of the GRIN fiber lens length and the refractive‐index profile of the coupler. The design of crossover and parallel interconnects by using a GRIN planar structure will be presented. The optical analysis includes the PSF for describing the performance of the device and the SBP for estimating the numbers of channels that can be handled. The dependence of the number of channels on the wavelength of light and the transverse aperture of the planar interconnect is shown.
Adaptive 4D MR imaging using navigator‐based respiratory signal for MRI‐guided therapy
Authors: Tokuda Junichi , Morikawa Shigehiro , Haque Hasnine A. , Tsukamoto Tetsuji , Matsumiya Kiyoshi , Liao Hongen , Masamune Ken , Dohi Takeyoshi
Published: April 2008

For real‐time 3D visualization of respiratory organ motion for MRI‐guided therapy, a new adaptive 4D MR imaging method based on navigator echo and multiple gating windows was developed. This method was designed to acquire a time series of volumetric 3D images of a cyclically moving organ, enabling therapy to be guided by synchronizing the 4D image with the actual organ motion in real time. The proposed method was implemented in an open‐configuration 0.5T clinical MR scanner. To evaluate the feasibility and determine optimal imaging conditions, studies were conducted with a phantom, volunteers, and a patient. In the phantom study the root mean square (RMS) position error in the 4D image of the cyclically moving phantom was 1.9 mm and the imaging time was ≈10 min when the 4D image had six frames. In the patient study, 4D images were successfully acquired under clinical conditions and a liver tumor was discriminated in the series of frames. The image quality was affected by the relations among the encoding direction, the slice orientation, and the direction of motion of the target organ. In conclusion, this study has shown that the proposed method is feasible and capable of providing a real‐time dynamic 3D atlas for surgical navigation with sufficient accuracy and image quality. Magn Reson Med 59:1051–1061, 2008. © 2008 Wiley‐Liss, Inc.
Multishot diffusion‐weighted SPLICE PROPELLER MRI of the abdomen
Authors: Deng Jie , Omary Reed A. , Larson Andrew C.
Published: April 2008

Multishot FSE (fast spin echo)‐based diffusion‐weighted (DW)‐PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) MRI offers the potential to reduce susceptibility artifacts associated with single‐shot DW‐EPI (echo‐planar imaging) approaches. However, DW‐PROPELLER in the abdomen is challenging due to the large field‐of‐view and respiratory motion during DW preparation. Incoherent signal phase due to motion will violate the Carr‐Purcell‐Meiboom‐Gill (CPMG) conditions, leading to destructive interference between spin echo and stimulated echo signals and consequent signal cancellation. The SPLICE (split‐echo acquisition of FSE signals) technique can mitigate non‐CPMG artifacts in FSE‐based sequences. For SPLICE, spin echo and stimulated echo are separated by using imbalanced readout gradients and extended acquisition window. Two signal families each with coherent phase properties are acquired at different intervals within the readout window. Separate reconstruction of these two signal families can avoid destructive phase interference. Phantom studies were performed to validate signal phase properties with different initial magnetization phases. This study evaluated the feasibility of combining SPLICE and PROPELLER for DW imaging of the abdomen. It is demonstrated that DW‐SPLICE‐PROPELLER can effectively mitigate non‐CPMG artifacts and improve DW image quality and apparent diffusion coefficient (ADC) map homogeneity. Magn Reson Med 59:947–953, 2008. © 2008 Wiley‐Liss, Inc.
Fat suppression for 1H MRSI at 7T using spectrally selective adiabatic inversion recovery
Authors: Balchandani Priti , Spielman Daniel
Published: April 2008

Proton magnetic resonance spectroscopic imaging (1H MRSI) at 7T offers many advantages, including increased SNR and spectral resolution. However, technical difficulties associated with operating at high fields, such as increased B1 and B0 inhomogeneity, severe chemical shift localization error, and converging T1 values, make the suppression of the broad lipid peaks which can obscure targeted metabolite signals, particularly challenging. Conventional short tau inversion recovery can successfully suppress fat without restricting the selected volume, but only with significant metabolite signal loss. In this work, we have designed two new pulses for frequency‐selective inversion recovery that achieve B1‐insensitive fat suppression without degrading the signal from the major metabolites of interest. The first is a spectrally selective adiabatic pulse to be used in a volumetric 1H MRSI sequence and the second is a spatial‐spectral adiabatic pulse geared toward multi‐slice 1H MRSI. Partial interior volume selection may be used in addition to the pulses, to exclude areas with severe B0 inhomogeneity. Some differences in the spectral profile as well as degree of suppression make each pulse valuable for different applications. 7T phantom and in vivo data show that both pulses significantly suppress fat, while leaving most of the metabolite signal intact. Magn Reson Med 59:980–988, 2008. © 2008 Wiley‐Liss, Inc.
Slice‐selective tunable‐flip adiabatic low peak‐power excitation pulse
Authors: Balchandani Priti , Pauly John , Spielman Daniel
Published: April 2008

Adiabatic pulses are useful in achieving uniform excitation profiles in the presence of B1‐inhomogeneity. At higher fields, this inhomogeneity becomes more severe, further amplifying the need for B1‐insensitive excitation. Although gradient modulation techniques for slice‐selective adiabatic excitation have been introduced, a pulse that falls within the gradient and RF amplifier limits for most commercial human scanners is currently unavailable. In this work, we present an alternative gradient modulated approach for pulse design that achieves adiabatic slice selection with significantly lower RF peak power requirements. The resulting Slice‐selective Tunable‐flip AdiaBatic Low peak‐power Excitation (STABLE) pulse consists of an oscillating gradient in conjunction with a BIR‐4‐like RF envelope that is sampled by many short spatial subpulses to achieve spatial selectivity. Simulations show that the expected spatial profile as well as the off‐resonance behavior of the pulse remain invariant for a range of B1 values. Phantom and in vivo results demonstrate the adiabaticity and slice selectivity of the STABLE pulse. Magn Reson Med 59:1072–1078, 2008. © 2008 Wiley‐Liss, Inc.
Single‐step nonlinear diffusion tensor estimation in the presence of microscopic and macroscopic motion
Authors: Aksoy Murat , Liu Chunlei , Moseley Michael E. , Bammer Roland
Published: April 2008

Patient motion can cause serious artifacts in diffusion tensor imaging (DTI), diminishing the reliability of the estimated diffusion tensor information. Studies in this field have so far been limited mainly to the correction of miniscule physiological motion. In order to correct for gross patient motion it is not sufficient to correct for misregistration between successive shots; the change in the diffusion‐encoding direction must also be accounted for. This becomes particularly important for multishot sequences, whereby—in the presence of motion—each shot is encoded with a different diffusion weighting. In this study a general mathematical framework to correct for gross patient motion present in a multishot and multicoil DTI scan is presented. A signal model is presented that includes the effect of rotational and translational motion in the patient frame of reference. This model was used to create a nonlinear least‐squares formulation, from which the diffusion tensors were obtained using a nonlinear conjugate gradient algorithm. Applications to both phantom simulations and in vivo studies showed that in the case of gross motion the proposed algorithm performs superiorly compared to conventional methods used for tensor estimation. Magn Reson Med 59:1138–1150, 2008. © 2008 Wiley‐Liss, Inc.
3D RINEPT {1H}‐31P CSI: A feasible approach for the study of membrane turnover in the human brain
Authors: Wokrina Tim , Ulrich Marco , Weber‐Fahr Wolfgang , Ende Gabriele
Published: April 2008

A fast, full 3D elliptical k‐space encoding phosphorous‐31 (31P) chemical shift imaging sequence, incorporating heteronuclear polarization transfer editing (RINEPT), was established. RINEPT literally requires simultaneous pulses at the frequencies of both the sensitive and the insensitive nuclei, but only a few MR imaging systems feature a second independent transmit channel. In this study, possible signal degradation of a sequential sequence design on systems featuring a single transmit channel was investigated with spin density matrix calculations and phantom measurements. In addition, metabolite signal intensities were determined in vivo as a function of echo and repetition times. The results enable optimization of the signal‐to‐noise ratio of one or more metabolites of interest. The results convincingly show that the optimized RINEPT sequence is useful in clinical routine 31PMRS protocols and provides spectra of excellent quality for the study of cell membrane phospholipid turnover in the human brain even at a low field strength of 1.5T. The 3D sequence design allows covering the whole brain in a single measurement, while scan times are compliant with clinical routine protocols. Magn Reson Med 59:999–1004, 2008. © 2008 Wiley‐Liss, Inc.
Uniform asymptotic Green's functions for efficient modeling of cracks in elastic layers with relative shear deformation controlled by linear springs
Authors: Peirce Anthony P. , Gu Hongren , Siebrits Eduard
Published: April 2008

We present a uniform asymptotic solution (UAS) for a displacement discontinuity (DD) that lies within the middle layer of a three‐layer elastic medium in which relative shear deformation between parallel interfaces is controlled by linear springs. The DD is assumed to be normal to the two interfaces between the elastic media. Using the Fourier transform method we construct a leading term in the asymptotic expansion for the spectral coefficient functions for a DD in a three‐layer‐spring medium. Although a closed‐form solution will require a solution in terms of an infinite series, we demonstrate how this UAS can be used to construct highly efficient and accurate solutions even in the case in which the DD actually touches the interface. We compare the results using the Green's function UAS solution for a crack crossing a soft interface with results obtained using a multi‐layer boundary element method. We also present results from an implementation of the UAS Green's function approach in a pseudo‐3D hydraulic fracturing simulator to analyze the effect of interface shear deformation on the fracture propagation process. These results are compared with field measurements. Copyright © 2008 John Wiley & Sons, Ltd.
A hypoplastic model for mechanical response of unsaturated soils
Authors: Mašín David , Khalili Nasser
Published: April 2008

A new constitutive model is developed for the mechanical behaviour of unsaturated soils based on the theory of hypoplasticity and the effective stress principle. The governing constitutive relations are presented and their application is demonstrated using several experimental data from the literature. Attention is given to the stiffening effect of suction on the mechanical response of unsaturated soils and the phenomenon of wetting‐induced collapse. All model parameters have direct physical interpretation, procedures for their quantification from test data are highlighted. Quantitative predictions of the model are presented for wetting, drying and constant suction tests. Copyright © 2008 John Wiley & Sons, Ltd.
Explanation for micromorphologies around broken fibers in fiber‐reinforced composites
Authors: Li Hongzhou , Jia Yuxi , Luan Shifang , Xiang Qian , Han Charles C. , Mamtimin Geni , Han Yanchun , An Lijia
Published: April 2008

Experimental observations on micromorphologies around broken fibers in glass‐fiber‐reinforced epoxy matrix composites reveal different kinds of highly oriented patches at the circumambience of broken fibers, whereas the bulk of the matrix has been observed to be largely isotropic. These patches are interpreted to correlated areas where the stress gradients of the matrix are formed after fiber breaking, but the underlying cause for the orientation is still unknown. The authors have modified an embedded cell model to explain the experimental phenomena. The finite element simulation indicates that the surfaces around broken fibers display a change from an extension micromorphology to a mixed tension and shear micromorphology with the increase of applied strain. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Hygrothermal degradation of the composite laminates from woven carbon/SC‐15 epoxy resin and woven glass/SC‐15 epoxy resin
Authors: Jana R.N. , Bhunia H.
Published: April 2008

The degradation mechanism for hygrothermal aging of woven carbon‐epoxy and woven glass‐epoxy composite laminates was investigated in the micro‐scale. Interlaminar shear and cross laminar flexural tests were performed on notched and unnotched specimens to know the mechanical performance of the composite laminates. The Interlaminar Shear Stress (ISS) for both the composites was also evaluated and correlated with the number of hygrothermal cycles. Four‐point bending and tensile or compression shear loading configurations were also used. The stress at the onset of delamination (Delamination Damage Tolerance, DDT) was identified from the load‐deflection curve of the flexural specimens and correlated with the number of hygrothermal cycles. It was found that both the ISS and DDT decrease with the exposure time. Dimensional stability was almost unchanged throughout the aging process, although there was a very little moisture absorption (∼1.3%) in glass‐epoxy and carbon‐epoxy composite laminates. SEM photomicrographs of the delaminated surface show that failure occurs suddenly in a macroscopically brittle mode by crack initiation and propagation method. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers.
Epoxy resin/plasticized carbon black composites. Part II. Correlation among network structure and mechanical properties
Authors: Abdel‐Aal N. , El‐Tantawy Farid , Al‐Hajry A. , Bououdina M.
Published: April 2008

The network structure, mechanical properties, and thermal gravimetric of epoxy resin filled with plasticized carbon black (CB) have been studied. The effect of CB concentration on composite morphology as well as cross linking density (n), volume fraction of resin (Vr), degree of crystallinity (Xc), mean gap among conductive particles (g), aspect ratio (F), and mechanical property such as modulus of elasticity (Ym), hardness (HA), and elongation at break (EB) have been examined and correlated to establish structure–property relationships. According to the thermal gravimetric analysis, the thermal decomposition of the composite took place at a slightly higher temperature than that of green epoxy. It proved that the inclusion of plasticized CB improves the quality of the network structure and enhances the mechanical properties of the composites. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers.
The safety of rosuvastatin in comparison with other statins in over 25 000 statin users in the Saskatchewan Health Databases
Authors: García‐Rodríguez Luis Alberto , González‐Pérez Antonio , Stang Mary Rose , Wallander Mari‐Ann , Johansson Saga
Published: April 2008

Purpose

To compare mortality and the incidence of hospitalization for myopathy, rhabdomyolysis, acute renal failure and acute liver injury in patients receiving rosuvastatin and those taking other statins.

Methods

Patients prescribed a statin that they had not used before were selected from the Saskatchewan Health Databases (SHD) and followed up from 1 July 2003 until 31 March 2005.

Results

We studied 10 384 patients on rosuvastatin and 14 854 taking other statins. Two cases of myopathy were identified (one on rosuvastatin, one on another statin). The relative risk (RR) of myopathy in patients currently taking rosuvastatin compared with other statins was 1.31 (95% confidence interval [CI]: 0.13–13.41). Two cases of rhabdomyolysis were detected among current rosuvastatin users (incidence: 2.9 [95% CI: 0.8–10.7] per 10 000 person‐years). No cases of acute liver injury occurred among rosuvastatin patients. Seventeen cases of acute renal failure were identified (five among rosuvastatin users, 12 taking other statins). The RR of acute renal failure in current rosuvastatin users compared with other statins was 0.49 (95% CI: 0.16–1.50).

We identified 285 deaths during the study period (87 among rosuvastatin users, 198 taking other statins). The RR of death in current rosuvastatin users compared with other statins was 0.42 (95% CI: 0.32–0.57).

Conclusions

We found no evidence that patients prescribed rosuvastatin were at greater risk of the study outcomes than patients prescribed other statins. There was no evidence of increased mortality among patients taking rosuvastatin, even after allowing for age, sex and prior statin use. Copyright © 2008 John Wiley & Sons, Ltd.
The safety of rosuvastatin in comparison with other statins in over 100 000 statin users in UK primary care
Authors: García‐Rodríguez Luis Alberto , Massó‐González Elvira Luján , Wallander Mari‐Ann , Johansson Saga
Published: April 2008

Purpose

To compare mortality and the incidence of hospitalization for myopathy, rhabdomyolysis, acute renal failure and acute liver injury in patients receiving rosuvastatin and those taking other statins.

Methods

Patients prescribed a statin that they had not used before were selected from the UK General Practice Research Database (GPRD) and followed up from 1 April 2003 to 31 December 2005.

Results

We studied 10 289 patients on rosuvastatin and 117 102 taking other statins. No cases of myopathy, rhabdomyolysis or acute liver injury occurred among rosuvastatin users. In those taking statins other than rosuvastatin, the incidence of myopathy was 0.4 (95% confidence interval (CI): 0.1–0.9), of rhabdomyolysis was 0.4 (95%CI: 0.1–0.9) and of acute liver injury was 0.4 (95%CI: 0.2–1.0), per 10 000 person‐years. Fourteen cases of acute renal failure were identified (two among rosuvastatin users and 12 among other statin users). Among current users, the relative risk (RR) of acute renal failure in rosuvastatin users compared with other statin users was 1.16 (95%CI: 0.15–9.03).

We identified 3232 deaths during the study period (173 in the rosuvastatin‐treated group and 3059 in the other statin group). The RR of death associated with current use of rosuvastatin compared with other statins was 0.55 (95%CI: 0.44–0.68).

Conclusions

We found no evidence that patients prescribed rosuvastatin were at greater risk of these outcomes than patients prescribed other statins. There was no evidence of increased mortality among patients taking rosuvastatin, even after allowing for age, sex and prior statin use. Copyright © 2008 John Wiley & Sons, Ltd.
A fluorescence approach of the gamma radiation effects on gramicidin A inserted in liposomes
Authors: Nae Maria , Gazdaru Doina , Acasandrei Adriana , Georgescu Rodica , Macri Beatrice Mihaela , Radu Mihai
Published: April 2008

The fluorescence of tryptophan residues of gramicidin A (gA), bound to phosphatidylcholine liposomes contains valuable information about local changes in the environment of the molecule induced by gamma radiation. With this work, we aim to demonstrate that the gamma radiation effect on the peptide involves the action of free radicals, derived from water radiolysis and the process of lipid peroxidation. Basically, the methodology consists of the analysis of UV and fluorescence emission spectra of the peptide liposome complexes under control conditions and upon gamma irradiation. Free radical production was impaired by the removal of molecular oxygen or the presence of ethanol in the liposome suspension. The intensity of the tryptophan fluorescence was recorded as a function of the gamma radiation dose in the range of 0–250 Gy and the data were fitted with a single decay exponential function containing an additional constant term (named residual fluorescence). The correlation between the decrease in tryptophan fluorescence emission (Dc = 80 ± 10 Gy) and increase in gamma radiation dose indicates the partial damage of the tryptophan side chains of gA. O2 removal or ethanol addition partially reduced the decay of the tryptophan fluorescence emission involving an indirect action of gamma radiation via a water radiolysis mechanism. The residual fluorescence emission (A0) increases in O2‐free buffer (98 ± 13) and in 10% ethanol‐containing buffer (74 ± 34) compared to control conditions (23 ± 5). Varying the dose rate between 1–10 Gy/min at a constant dose of 50 Gy, an inverse dose‐rate effect was observed. Thus, our study provides evidence for the lipid peroxidation effect on the tryptophan fluorescence. In conclusion, this article sustains the hypothesis of the connection between the lipid peroxidation and structural changes of membrane proteins induced by gamma radiation. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
A lactoferrin‐derived peptide with cationic residues concentrated in a region of its helical structure induces necrotic cell death in a leukemic cell line (HL‐60)
Authors: Onishi Junko , Roy Molay Kumar , Juneja Lekh Raj , Watanabe Yasuo , Tamai Youichi
Published: April 2008

Model studies have shown that peptides derived from the N‐terminal region of bovine lactoferrin (Lf‐B) exhibit antitumor activity against certain cell lines. This activity is due primarily to the peptides' apoptogenic effect. Several reports indicate that cationic residues clustered in two regions of the peptide sequence can be shuffled into one region and thereby increase cytotoxic activity, although the mechanism of this enhanced cytotoxic effect has not been clarified. In this paper, we considered several parameters that determine the mode of cell death after exposure to a native Lf‐B derived peptide (Pep1, residues 17–34), and a modified peptide (mPep1) wherein the cationic residues of Pep1 are clustered in a single region of its helical structure. We found that the cytotoxic activity of mPep1 was about 9.6 fold‐higher than that of Pep1 against HL‐60 cells, as determined by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐5(3‐carboxymethonyphenol)‐2‐(4‐sulfophenyl)‐2 H‐tetrazolium (MTS) assay. In investigating the expression of phosphatidylserine, we observed that the native peptide (Pep1) caused both apoptotic cell death and necrotic cell death, depending on the concentration of the peptide. In contrast, the action of mPep1 was exclusively characteristic of necrotic cell death. This observation was further confirmed by agarose gel electrophoresis, in which clear ladder‐like DNA bands were observed from cells exposed to Pep1, whereas DNA from cells treated with mPep1 produced a smeared pattern. We extended the study by investigating the release of mitochondrial cytochrome c into the cytosol, and the activation of caspase‐3; both peptides caused the release of cytochrome c into the cytosol, and the activation of caspase‐3.

These results suggest that Pep1 may kill cancer cells by activating an apoptosis‐inducing pathway, whereas mPep1 causes necrotic cell death by destroying cellular membrane structure notwithstanding sharing some cellular events with apoptotic cell death. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Cryogenic characteristics of sub‐100‐nm‐gate AlGaN/GaN MIS‐HEMTs
Authors: Endoh Akira , Watanabe Issei , Yamashita Yoshimi , Mimura Takashi , Matsui Toshiaki
Published: April 2008

We measured DC and RF characteristics at 300 and 16 K of sub‐100‐nm‐gate AlGaN/GaN metal‐insulator‐semiconductor (MIS) high electron mobility transistors (HEMTs) that had SiN/SiO2/SiN triple‐layer insulators. The drain‐source current and the maximum transconductance increased as expected. We observed an increase of 14 to 28% in the value of cutoff frequency fT at 16 K over that at 300 K. At 16 K, we obtained a maximum fT of 176 GHz at a gate length Lg of 45 nm. We estimated the average electron velocity under the gate by a transit time analysis. The average velocities were 2.2 × 107 cm/s at 300 K and 2.7 × 107 cm/s at 16 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electroluminescence characteristics of GaN HEMT at off‐state
Authors: Chen H. , Lai Z. , Kung S. , Penner R. , Li G. P.
Published: April 2008

Two types of light emission characteristics at the off‐state breakdown of GaN HEMTs were observed and investigated. One of them showed a yellow band electroluminescence characteristic at room temperature, which might be attributed to the same origin of yellow luminescence (YL) defects. The electric field dependence of this YL‐like light emission was found to be more sensitive than the other type. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biexciton recombination in high quality GaN/AlGaN quantum wells
Authors: Stokker‐Cheregi F. , Vinattieri A. , Feltin E. , Simeonov D. , Carlin J.‐F. , Butté R. , Grandjean N. , Gurioli M.
Published: April 2008

We report on a clear experimental demonstration of the presence of biexciton recombination in high quality GaN/AlGaN quantum wells, thus opening the way to relevant improvements of the performances of GaN based devices. The samples have been grown by metalorganic vapor phase epitaxy optimizing the deposition conditions to strongly reduce the Al fluctuations in the barriers. This leads to a photoluminescence broadening of only 5 meV at a temperature of 10 K for an Al content in the barriers of 5%. The biexciton binding energy if found to be of the order of 9 meV. The recombination kinetics show that the exciton and biexciton components are not thermalized at low temperature allowing to extract the intrinsic lifetimes of the two components. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and transport properties of InN grown on GaN by MBE
Authors: Wang Kejia (Albert) , Kosel Thomas , Jena Debdeep
Published: April 2008

In this work, the growth of InN on GaN substrates by molecular beam epitaxy and the structural and electrical characterization are presented. The quality of InN is found to be a sensitive function of the III/V flux ratio and the substrate temperature. The structural quality of InN is characterized by X‐ray diffraction, and the transport property is characterized by Hall effect measurements. An optimum growth window to obtain high structural quality InN with high electron mobility is observed. A strong correlation between the structural quality and the measured Hall mobility is shown. Transmission electron microscope study of InN shows high dislocation density (∼2 × 1011 cm–2 at 200 nm from the InN/GaN interface), which is the limiting factor for the transport property in InN. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of rare earth point defects in GaN
Authors: Sanna Simone , Hourahine B. , Frauenheim Th. , Gerstmann U.
Published: April 2008

The behavior of rare earth dopants in GaN was investigated by means of theoretical techniques. The Density Functional based Tight‐Binding method (DFTB) has been extended to include orbital dependent potentials (LDA+U and SIC‐like) in attempt to model the 4f states of lanthanide impurities within a realistic crystal model. We present results of an investigation into the structural and and energetic properties of rare earth (Eu, Er and Tm) point defects in GaN. Lanthanide ions (either isolated or complexed with GaN native defects) prefer the Ga‐site. Among the investigated defects the REGaVN pairs are the most promising candidates as luminescent centers, while interstitial lanthanides are found not to be compatible with the observed luminescence. Differences in the behavior of the single lanthanide ions are explained in terms of different 4f ‐shell occupation and ion size. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How to optimize a CH cleavage with a mononuclear copper–dioxygen adduct?
Authors: De La Lande A. , Gérard H. , Parisel O.
Published: April 2008

We here report the investigations on the role of the charge transfer (CT) from copper toward dioxygen on the activation barrier of the CH bond breaking in a model [Cu(trenCH3)(O2)]+ adduct. By playing on the donating capability of the trenCH3 ligand, by means of a supplementary pseudopotential applied on the apical nitrogen atom, the existence of an optimum CT to achieve the rupture of the CH bond is revealed. When considering the dioxygen/superoxide/peroxide range in its whole, it appears that both dioxygen‐ and peroxide‐type complexes are poor oxidant toward the CH bond. At variance, superoxide dominant complexes are confirmed to be better suited for a reactive purpose. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Competitive coordination between lead and oligoelements with respect to some therapeutic heavy‐metal chelators
Authors: Gourlaouen C. , Parisel O.
Published: April 2008

The competitive complexation of Ca2+, Fe2+, Cu2+, Zn2+, and Pb2+ toward ethylene diamine tetraacetate (EDTA), dimercaprol and D‐penicillamine, three liganding agents commonly used in chelation therapy against heavy metal, especially lead, poisonings is examined by means of B3LYP calculations, natural population analyses, and the topological analysis of the electron localization function. It is shown that Pb2+ can displace any of Ca2+, Fe2+, Cu2+, or Zn2+ chelated by any of dimercaprol or D‐penicillamine, but can only displace Ca2+ if EDTA is concerned. The first two chelators thus appear as better entities than EDTA to be used in chelation therapy, where in vivo selective complexation is essential. Moreover, the comparison of the bonding characteristics of Pb2+ with those of the other cations allows deriving three features to be taken into account in designing new chelators expecting to have an increased selectivity toward this cation. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Feedback–feedforward individual pitch control for wind turbine load reduction
Authors: Selvam K. , Kanev S. , van Wingerden J. W. , van Engelen T. , Verhaegen M.
Published: April 2008

This paper focuses on the problem of wind turbine fatigue load reduction by means of individual pitch control (IPC). The control approach has a two‐degree‐of‐freedom structure, consisting of an optimal multivariable LQG controller and a feedforward disturbance rejection controller based on estimated wind speed signals. To make the control design problem time invariant, all signals are transformed to the non‐rotating reference frame using the Coleman transformation. In the Coleman domain, the LQG control objective is minimization of the rotor tilt and yaw moments, whereas the feedforward controller tries to achieve even further improvement by rejecting the influence of the low‐frequency components of the wind on the rotor moments. To this end, the tilt‐ and yaw‐oriented components of the blade‐effective wind speeds are approximated using stochastic random walk models, the states of which are then augmented with the turbine states and estimated using a Kalman filter. The effects of these (estimated) disturbances on the controlled outputs are then reduced using stable dynamic model inversion. The approach is tested and compared with the conventional IPC method in simulation studies with models of different complexities. The results demonstrate very good load reduction at not only low frequencies (1p blade fatigue load reduction) but also at the 3p frequency, giving rise to fatigue load reduction of the non‐rotating turbine components. Copyright © 2008 John Wiley & Sons, Ltd.
Correction
Authors: Borghi Elaine
Published: April 2008

‘Construction of the World Health Organization child growth standards: selection of methods for attained growth curves’ by Borghi E, de Onis M, Garza C, Van den Broeck J, Frongillo EA, Grummer‐Strawn L, Van Buuren S, Pan H, Molinari L, Martorell R, Onyango AW, Martines JC, for the WHO Multicentre Growth Reference Study Group (Statistics in Medicine 2006; 25:247–265).

The correct reference for citation [59] was supposed to be [59] Dunn PK, Smyth GK. Randomized quantile residuals. Journal of Computational and Graphical Statistics 1996; 5(3):236–244.

The authors offer their apologies to the authors of the cited paper and readers.
Reduced‐rank proportional hazards regression and simulation‐based prediction for multi‐state models
Authors: Fiocco Marta , Putter Hein , van Houwelingen Hans C.
Published: April 2008

In this paper we address two issues arising in multi‐state models with covariates. The first issue deals with how to obtain parsimony in the modeling of the effect of covariates. The standard way of incorporating covariates in multi‐state models is by considering the transitions as separate building blocks, and modeling the effect of covariates for each transition separately, usually through a proportional hazards model for the transition hazard. This typically leads to a large number of regression coefficients to be estimated, and there is a real danger of over‐fitting, especially when transitions with few events are present. We extend the reduced‐rank ideas, proposed earlier in the context of competing risks, to multi‐state models, in order to deal with this issue.

The second issue addressed in this paper was motivated by the wish to obtain standard errors of the regression coefficients of the reduced‐rank model. We propose a model‐based resampling technique, based on repeatedly sampling trajectories through the multi‐state model. The same ideas are also used for the estimation of prediction probabilities in general multi‐state models and associated standard errors.

We use data from the European Group for Blood and Marrow Transplantation to illustrate our techniques. Copyright © 2008 John Wiley & Sons, Ltd.
Heat‐Moisture Treatment and Enzymatic Digestibility of Peruvian Carrot, Sweet Potato and Ginger Starches
Authors: Vieira Fabiana C. , Sarmento Silene B. S.
Published: April 2008

The aim of this work was to study the effects of heat‐moisture treatment (27% moisture, 100°C, 16 h) and of enzymatic digestion (alpha‐amylase and glucoamylase) on the properties of sweet potato (SP), Peruvian carrot (PC) and ginger (G) starches. The structural modification with heat‐moisture treatment (HMT) affected crystallinity, enzyme susceptibility and viscosity profile. The changes in PC starch were the most pronounced, with a strong decrease of relative crystallinity (from 0.31 to 0.21) and a shift of X‐ray pattern from B‐ to A‐type. HMT of SP and G starch did not change the X‐ray pattern (A‐type). The relative crystallinity of these starches changed only slightly, from 0.32 to 0.29 (SP) and from 0.33 to 0.32 (G). The extent of these structural changes (PC > SP > G) altered the susceptibility of the starches to enzymatic attack, but not in same order (PC > G > SP). HMT increased the starches digestion, probably due to rearrangement of disrupted crystallites, increasing accessible areas to attack of enzymes. The viscosity profiles and values changed significantly with HMT, resulting in higher pasting temperatures, decrease of viscosity values and no breakdown, i.e., stability at high temperatures and shear rates. Changes in pasting properties appeared to be more significant for PC and SP starch, whereas the changes for G starch were small. Setback was minimized following HMT in SP and G starches.
Effect of Glycerol on Water Vapor Sorption and Mechanical Properties of Starch/Clay Composite Films
Authors: Yu Jian‐hua , Wang Jia‐li , Wu Xiao , Zhu Pu‐xin
Published: April 2008

Plasticized starch/clay composite films were prepared by casting aqueous solutions containing oxidized corn starch, different concentrations of glycerol as a plasticizer and 5% clay (sodium montmorillonite, Na+‐MMT) on the basis of dry starch. The water‐binding properties of the composite films were evaluated by water vapor sorption isotherms at room temperature and various relative humidities (RHs). Mechanical properties and abrasion resistance were also analyzed for the films with varying glycerol contents at 68% RH and room temperature. Changes in water sorption isotherms suggested that glycerol interacted with both water and starch in a complicated way. A saturation phenomenon of glycerol, depending on RH, was observed based on the isotherms. Above this saturation content, phase separation of the system occurred with the appearance of free glycerol. According to mechanical performance and abrasion resistance, as well as water vapor sorption of the starch blend films, the three‐stage transition was presented to be related to the state of glycerol in the blend system, i.e. adsorption of glycerol onto H‐bonding sites of starch, supersaturation of glycerol as plasticizer and further supersaturation of glycerol. Only above the supersaturation content can glycerol play a plasticizer role in starch‐based composites.
MARS: a multiple access scheme with sender driven and reception first for smart antenna inad hocnetworks
Authors: Lai Wei Kuang , Tseng Kuo‐Shu , Chen Jiunn‐Ching
Published: April 2008

The deployment of directional antennas offers many advantages, such as transmission range extension, co‐channel interference reducing, the increasing of spatial reuse degree, throughput improving of networks, and transmission power saving. Hence, manyad hocMAC protocols with directional antennas have been proposed. However, these protocols do not provide significant improvement of network performance due to the lack of supporting multiple transmissions and receptions simultaneously. With the adaptive beam‐forming system (Smart Antenna), a newly designed MAC protocol (MARS) that enables nodes with multiple transmissions and receptions is proposed. Simulation results show that our MARS do exploit the advantage of space division multiple access. In terms of total number of data forward and complete sessions in bottleneck nodes, MARS achieves three times better than Novel and nine times better than IEEE 802.11. In addition, the end‐to‐end delay keeps very short. Copyright © 2008 John Wiley & Sons, Ltd.