bluuebunny/crossref_metadata_2025 huggingface dataset:
NMR spectra, GIAO and charge density calculations of five‐membered aromatic heterocycles
Authors: Katritzky Alan R. , Akhmedov Novruz G. , Doskocz Jacek , Mohapatra Prabhu P. , Hall C. Dennis , Güven Alâattin
Published: May 2007

The B3LYP/6‐31 + G(d) molecular geometry optimized structures of 17 five‐membered heterocycles were employed together with the gauge including atomic orbitals (GIAO) density functional theory (DFT) method at the B3LYP/6‐31 + G(d,p), B3LYP/6‐311 + + G(d,p) and B3LYP/6‐311 + G(2d,p) levels of theory for the calculation of proton and carbon chemicals shifts and coupling constants. The method of geometry optimization for pyrrole (1), N‐methylpyrrole (2) and thiophene (7) using the larger 6‐311 + + G(d,p) basis sets at the B3LYP/6‐31 + G(d,p), B3LYP/6‐311 + + G(d,p), B3LYP/6‐31 + G(2d,p) and B3LYP/cc‐pVTZ levels of theory gave little difference between calculated and experimental values of coupling constants. In general, the 1H and 13C chemical shifts for all compounds are in good agreement with theoretical calculations using the smaller 6‐31 basis set. The values of nJHH(n = 3, 4, 5) and rmnJCH(n = 1, 2, 3, 4) were predicted well using the larger 6‐31 + G(d,p) and 6‐311 + + G(d,p) basis sets and at the B3LYP/6‐31 + G(d,p), B3LYP/6‐311 + + G(d,p), B3LYP/6‐31 + G(2d,2p) levels of theory. The computed atomic charges [Mülliken; Natural Bond Orbital Analysis (NBO); Merz‐Kollman (MK); CHELP and CHELPG] for the B3LYP/6‐311 + + G(d,p) geometry optimized structures of 1–17 were used to explore correlations with the experimental proton and carbon chemical shifts. Copyright © 2007 John Wiley & Sons, Ltd.
1H and 13C NMR assignments for two new angular furanocoumarin glycosides from Peucedanum praeruptorum
Authors: Chang Haitao , Okada Yoshihito , Okuyama Toru , Tu Pengfei
Published: May 2007

Two novel angular‐type furanocoumarin glycosides, peucedanoside A (1) and peucedanoside B (2), along with a known compound apterin (3), were isolated from the roots of Peucedanum praeruptorum Dunn. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments including DEPT, HSQC, HMBC and ROESY. Copyright © 2007 John Wiley & Sons, Ltd.
Passive catheter tracking during interventional MRI using hyperpolarized 13C
Authors: Magnusson Peter , Johansson Edvin , Månsson Sven , Petersson J. Stefan , Chai Chun‐Ming , Hansson Georg , Axelsson Oskar , Golman Klaes
Published: May 2007

Interventional procedures in MRI can be performed preclinically using active or passive catheter‐tracking methods. A novel passive nonproton technique is suggested that uses a catheter filled with a hyperpolarized 13C contrast agent. A prototype three‐lumen catheter was built with two closed lumens containing a flowing hyperpolarized 13C contrast agent. Entire‐length 13C catheter projection visualization could be performed in vivo with a catheter SNR of ∼80, one dual projection frame per ∼700 ms, and an in‐plane resolution of 2 × 2 mm2 while traveling through the aorta of a pig. The traveling path of the 13C catheter was visualized after back‐projection catheter reconstruction and after image fusion with an anatomical offline proton road map. Catheter length visualization was aided by an oblique planar visualization mode. The high catheter signal demonstrated, together with the entire catheter length visualization and high surrounding soft‐tissue contrast, warrants further development into a real‐time technique. Magn Reson Med 57:1140–1147, 2007. © 2007 Wiley‐Liss, Inc.
High‐field actively detuneable transverse electromagnetic (TEM) coil with low‐bias voltage for high‐power RF transmission
Authors: Avdievich Nikolai I. , Bradshaw Ken , Kuznetsov Andrey M. , Hetherington Hoby P.
Published: May 2007

The design and construction of a 4T (170 MHz) transverse electromagnetic (TEM) actively detuneable quadrature head coil is described. Conventional schemes for active detuning require high negative bias voltages (>300 V) to prevent leakage of RF pulses with amplitudes of 1–2 kW. To extend the power handling capacity and avoid the use of high DC bias voltages, we developed an alternate method of detuning the volume coil. In this method the PIN diodes in the detuning circuits are shorted when the RF volume coil is tuned, and negatively biased with –12 V when the coil is detuned. To preserve the high QU/QL ratio of the TEM coil, we modified the method of Nabetani and Watkins (Proceedings of the 13th Annual Meeting of ISMRM, Kyoto, Japan, 2004, abstract 1574) by utilizing a high‐impedance (∼200 Ω), lumped‐element, quarter‐wavelength transformer. A QU of 500 was achieved for the detuneable TEM, such that incorporation of the detuning network had minimal effect (<1 dB) on the performance of the coil in vivo. Magn Reson Med 57:1190–1195, 2007. © 2007 Wiley‐Liss, Inc.
Longitudinal gradient coil optimization in the presence of transient eddy currents
Authors: Trakic A. , Liu F. , Lopez H. Sanchez , Wang H. , Crozier S.
Published: May 2007

The switching of magnetic field gradient coils in magnetic resonance imaging (MRI) inevitably induces transient eddy currents in conducting system components, such as the cryostat vessel. These secondary currents degrade the spatial and temporal performance of the gradient coils, and compensation methods are commonly employed to correct for these distortions. This theoretical study shows that by incorporating the eddy currents into the coil optimization process, it is possible to modify a gradient coil design so that the fields created by the coil and the eddy currents combine together to generate a spatially homogeneous gradient that follows the input pulse. Shielded and unshielded longitudinal gradient coils are used to exemplify this novel approach. To assist in the evaluation of transient eddy currents induced within a realistic cryostat vessel, a low‐frequency finite‐difference time‐domain (FDTD) method using the total‐field scattered‐field (TFSF) scheme was performed. The simulations demonstrate the effectiveness of the proposed method for optimizing longitudinal gradient fields while taking into account the spatial and temporal behavior of the eddy currents. Magn Reson Med 57:1119–1130, 2007. © 2007 Wiley‐Liss, Inc.
Functional MRI impulse response for BOLD and CBV contrast in rat somatosensory cortex
Authors: Silva Afonso C. , Koretsky Alan P. , Duyn Jeff H.
Published: May 2007

The contrast mechanism in functional MRI (fMRI) results from several vascular processes with different time scales, thus establishing a finite temporal resolution to fMRI experiments. In this work we measured the blood oxygen level‐dependent (BOLD) and iron‐oxide‐derived cerebral blood volume (CBV) impulse response (IR) in a rat model of somatosensory brain activation at 11.7T. A binary m‐sequence probe method was used to obtain high‐sensitivity single‐pixel estimates of the IR, from which two parameters—the full width at half maximum (FWHM) and the time to peak (TTP)—were determined as indices of the temporal resolution of the hemodynamic response (HDR). The results (N = 11) show that the CBV IR (N = 5, subset) is significantly narrower (FWHM = 1.37 ± 0.11 s), and peaks earlier (TTP = 1.65 ± 0.15 s) than the BOLD IR (N = 11, FWHM = 1.92 ± 0.22 s and TTP = 2.18 ± 0.14 s, respectively). These findings indicate that neurovascular control mechanisms have a temporal resolution better than 1.5 s FWHM, and point to a substantial contribution to BOLD of the dispersive transit of oxygenated hemoglobin across the rat vasculature, bringing important implications for the ultimately attainable temporal resolution of fMRI. Magn Reson Med 57:1110–1118, 2007. © 2007 Wiley‐Liss, Inc.
Temporally constrained reconstruction of dynamic cardiac perfusion MRI
Authors: Adluru Ganesh , Awate Suyash P. , Tasdizen Tolga , Whitaker Ross T. , DiBella Edward V.R.
Published: May 2007

Dynamic contrast‐enhanced (DCE) MRI is a powerful technique to probe an area of interest in the body. Here a temporally constrained reconstruction (TCR) technique that requires less k‐space data over time to obtain good‐quality reconstructed images is proposed. This approach can be used to improve the spatial or temporal resolution, or increase the coverage of the object of interest. The method jointly reconstructs the space‐time data iteratively with a temporal constraint in order to resolve aliasing. The method was implemented and its feasibility tested on DCE myocardial perfusion data with little or no motion. The results obtained from sparse k‐space data using the TCR method were compared with results obtained with a sliding‐window (SW) method and from full data using the standard inverse Fourier transform (IFT) reconstruction. Acceleration factors of 5 (R = 5) were achieved without a significant loss in image quality. Mean improvements of 28 ± 4% in the signal‐to‐noise ratio (SNR) and 14 ± 4% in the contrast‐to‐noise ratio (CNR) were observed in the images reconstructed using the TCR method on sparse data (R = 5) compared to the standard IFT reconstructions from full data for the perfusion datasets. The method has the potential to improve dynamic myocardial perfusion imaging and also to reconstruct other sparse dynamic MR acquisitions. Magn Reson Med 57:1027–1036, 2007. © 2007 Wiley‐Liss, Inc.
Human brain‐structure resolved T2 relaxation times of proton metabolites at 3 tesla
Authors: Zaaraoui Wafaa , Fleysher Lazar , Fleysher Roman , Liu Songtao , Soher Brian J. , Gonen Oded
Published: May 2007

The transverse relaxation times, T2, of N‐acetylaspartate (NAA), total choline (Cho), and creatine (Cr) obtained at 3T in several human brain regions of eight healthy volunteers are reported. They were obtained simultaneously in 320 voxels with three‐dimensional (3D) proton MR spectroscopy (1H‐MRS) at 1 cm3 spatial resolution. A two‐point protocol, optimized for the least error per given time by adjusting both the echo delay (TEi) and number of averages, Ni, at each point, was used. Eight healthy subjects (four males and four females, age = 26 ± 2 years) underwent the hour‐long procedure of four 15‐min, 3D acquisitions (TE1 = 35 ms, N1 = 1; and TE2 = 285 ms, N2 = 3). The results reveal that across all subjects the NAA and Cr T2s in gray matter (GM) structures (226 ± 17 and 137 ± 12 ms, respectively) were 13–17% shorter than the corresponding T2s in white matter (WM; 264 ± 10 and 155 ± 7 ms, respectively). The T2s of Cho did not differ between GM and WM (207 ± 17 and 202 ± 8, respectively). For the purpose of metabolic quantification, these values justify to within ±10% the previous use of one T2 per metabolite for 1) the entire brain and 2) all subjects. These T2 values (which to our knowledge were obtained for the first time at this field, spatial resolution, coverage, and precision) are essential for reliable absolute metabolic quantification. Magn Reson Med 57:983–989, 2007. © 2007 Wiley‐Liss, Inc.
Uncertain policy for an uncertain world: The case of social security
Authors: Sabelhaus John , Topoleski Julie
Published: May 2007

Analysis and discussion of Social Security policy are usually based on expected fiscal and societal outcomes. However, future demographic and economic trends are uncertain, and thus ultimate outcomes for aggregate system financial flows and the distribution of taxes and benefits across generations are uncertain. This paper analyzes a state‐dependent approach to policy in which future Social Security benefit formulas are tied to realized economic and demographic outcomes over time. The results, based on a microsimulation model with stochastic capabilities, show the extent to which it is possible to systematically address uncertainty about system finances and distributional outcomes. © 2007 by the Association for Public Policy Analysis and Management
Microstructure and nematic transition in thermotropic liquid crystalline fibers and their single polymer composites
Authors: Cohen Estelle Kalfon , Marom Gad , Weinberg Amotz , Wachtel Ellen , Migliaresi Claudio , Pegoretti Alessandro
Published: May 2007

We describe a new single polymer composite (SPC) prepared from two liquid crystalline vectran fibers. Vectran M is the as‐spun fiber while vectran HS is the high‐strength version. A study of the morphology of the pristine materials shows that the two fibers have different crystal structures. The wide‐angle X‐ray diffraction (WAXD) data confirm the presence of the so‐called pseudo‐hexagonal (PH) unit cell in vectran M, while an orthorhombic structure is revealed in the vectran HS fibers. A transition to the nematic phase is observed by in situ X‐ray diffraction at ∼277°C for the M fibers and at ∼315°C for the HS fibers. During the compaction process, the orientation of the reinforcing fibers is well maintained and the transition to a nematic phase seems to be delayed by processing at high applied pressure. Concomitantly, vectran M loses its orientation and the transition to the nematic phase disappears. Copyright © 2007 John Wiley & Sons, Ltd.
Oncogenic role of JC virus in lung cancer
Authors: Zheng H , Aziz HO Abdel , Nakanishi Y , Masuda S , Saito H , Tsuneyama K , Takano Y
Published: May 2007

The JC virus (JCV) infects a large proportion of the population world wide and can cause progressive mulitifocal leucoencephalopathy in the context of immunodeficiency. Recent reports provide evidence that it may also be oncogenic. Here, JCV was examined by targeting its T‐antigen in lung carcinomas (n = 103) and normal lung tissues (n = 18) by nested‐PCR followed by Southern blot, real‐time PCR, immunohistochemistry, in situ hybridization and in situ PCR. Additionally, expression of Ki‐67, caspase‐3, β‐catenin, p53, and Rb was analysed by immunohistochemistry on tissue microarrays of lung carcinomas. Copy numbers of JCV were compared with clinicopathological features. Normal lung tissue was positive significantly less frequently, and contained a lower copy number of JCV than lung carcinomas (p < 0.05), and copies were lower in lung adenocarcinomas than in squamous, small or large cell carcinomas (p < 0.05). In situ PCR and immunolabelling revealed JCV positivity in the nuclei of lung carcinoma cells. The JCV copy number correlated closely with sex, and expression of Ki‐67 and membrane β‐catenin (p < 0.05), but not with age, tumour size, pleural invasion, lymph node metastasis, expression of caspase‐3, cytoplasmic β‐catenin, p53 or Rb, prognosis, smoking or cancer family history (p > 0.05). Age and UICC staging were independent prognostic factors for lung carcinoma patients. These data suggest that JCV may be involved in lung carcinogenesis, especially in tumour types other than adenocarcinoma. Lung carcinomas with higher JCV copy numbers display high proliferation and down‐regulation of cell adhesion mediated by membrane β‐catenin. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A prospective study on parental coping 4 months after termination of pregnancy for fetal anomalies
Authors: Korenromp M. J. , Page‐Christiaens G. C. M. L. , van den Bout J. , Mulder E. J. H. , Hunfeld J. A. M. , Potters C. M. A. A. , Erwich J. J. H. M. , van Binsbergen C. J. M. , Brons J. T. J. , Beekhuis J. R. , Omtzigt A. W. J. , Visser G. H. A.
Published: May 2007

Objective

To identify short‐term factors influencing psychological outcome of termination of pregnancy for fetal anomaly, in order to define those patients most vulnerable to psychopathology.

Study Design

A prospective cohort of 217 women and 169 men completed standardized questionnaires 4 months after termination. Psychological adjustment was measured by the Inventory of Complicated Grief (ICG), the Impact of Event Scale (IES), the Edinburgh Postnatal Depression Scale (EPDS), and the Symptom Checklist‐90 (SCL‐90).

Results

Women and men showed high levels of posttraumatic stress (PTS) symptoms (44 and 22%, respectively) and symptoms of depression (28 and 16%, respectively). Determinants of adverse psychological outcome were the following: high level of doubt in the decision period, inadequate partner support, low self‐efficacy, lower parental age, being religious, and advanced gestational age. Whether the condition was Down syndrome or another disability was irrelevant to the outcome. Termination did not have an important effect on future reproductive intentions. Only 2% of women and less than 1% of men regretted the decision to terminate.

Conclusion

Termination of pregnancy (TOP) for fetal anomaly affects parents deeply. Four months after termination a considerable part still suffers from posttraumatic stress symptoms and depressive feelings. Patients who are at high risk could benefit from intensified support. Copyright © 2007 John Wiley & Sons, Ltd.
Relaxation behavior of conductive carbon black reinforced EPDM microcellular vulcanizates
Authors: Mahapatra S.P. , Sridhar V. , Chaudhary R.N.P. , Tripathy D.K.
Published: May 2007

Dynamic mechanical analysis and dielectric relaxation spectra of conductive carbon black reinforced microcellular EPDM vulcanizates were used to study the relaxation behavior as a function of temperature (−90 to +100°C) and frequency (0.01–105Hz). The effect of filler and blowing agent loadings on dynamic mechanical and dielectric relaxation characteristics has been investigated. The effect of filler and blowing agent loadings on glass transition temperature was marginal for all the composites (Tgvalue was in the range of −39 to −35°C), which has been explained on the basis of relaxation dynamics of polymer chains in the vicinity of fillers. Strain‐dependent dynamical parameters were evaluated at dynamic strain amplitudes of 0.07–5%. The nonlinearity in storage modulus has been explained based on the concept of filler–polymer interaction and interaggregate attraction (filler networking) of carbon black. The variation in real and complex part of impedance with frequency has been studied as a function of filler and blowing agent loading. Additionally, the effect of crosslinking on the dielectric relaxation has also been reported. POLYM. ENG. SCI., 47:984–995, 2007. © 2007 Society of Plastics Engineers
Effects of polymerization medium on electrical conductivity and optical properties of organic semiconductor‐based polypyrrole
Authors: Yakuphanoglu Fahrettin , Aydin Mehmet Enver
Published: May 2007

The effects of tetrabutylammonium tetrafluoroborate (TBAFB), tetrabutylammonium hexafluorophosphate (TBAPF6), and paratoluene sulfonoicacid (PTSA) polymerization mediums on the electrical conductivity and optical properties of the polypyrrole (PPy) have been investigated. The electrical conductivity and optical properties of the samples polymerized in presence of TBAFB, TBAPF6, and PTSA organic salts change with medium of prepared polymer. The electrical conductivity of the TBAFB, PTSA, and TBAPF6 samples at 27°C were found to be 3.43 × 10−1, 4.48 × 10−2, and 1.60 × 10−4 (S/cm), respectively. The lowest optical band gap of the polymer was found to be 2.23 eV. The refractive index dispersion of the samples obeys single oscillator model. The obtained results suggest that polymerization medium changes electrical conductivity and optical properties of the PPy. POLYM. ENG. SCI., 47:1016–1020, 2007. © 2007 Society of Plastics Engineers
Study of melt compounding conditions and characterization of polyamide 6/metallocene ethylene‐polypropylene‐diene copolymer/maleated ethylene‐polypropylene‐diene copolymer blends reinforced with layered silicates
Authors: García‐López D. , López‐Quintana S. , Gobernado‐Mitre I. , Merino J.C. , Pastor J.M.
Published: May 2007

A low content of nanoclay (modified montmorillonite, MMT) was added to PA6/mEPDM/EPDM‐g‐MA blends via melt compounding in order to obtain three different nanoblends by two methods: (a) one‐step mixing in which the polymeric and the inorganic components were simultaneously introduced in the feed ports 1 and 2 of a corrotating twin‐screw extruder respectively; (b) two‐step mixing in which the PA6/mEPDM/EPDM‐g‐MA elastomeric blend was first obtained and in a second step the MMT was added at two different mixing speeds. The microscopic study and the mechanical characterization of the nanoblends showed a relationship between microstructure, processing conditions, and mechanical properties. A predominant reinforcement effect due to the presence of organoclays was observed. POLYM. ENG. SCI., 47:1033–1039, 2007. © 2007 Society of Plastics Engineers
Nonisothermal crystallization behavior and nucleation of LDPE/Al nano‐ and microcomposites
Authors: Huang Xingyi , Ke Qingquan , Kim Chonung , Zhong Hanfang , Wei Ping , Wang Genlin , Liu Fei , Jiang Pingkai
Published: May 2007

The nonisothermal crystallization and melting behavior of LDPE and LDPE/Al nano‐ and microcomposites prepared from melt compounding were studied using differential scanning calorimetry (DSC). The DSC results show that the Al nanoparticles can either facilitate or hinder the crystallization of LDPE, depending on the dispersion of the nanoparticles in LDPE. The well‐dispersed Al nanoparticles do not have nucleating effects and mainly act as obstacles in the crystallization process, but the agglomerates of Al nanoparticles can act as nucleating agents and slightly accelerate the crystallization process of LDPE. The Al microparticles have nucleating effect and facilitate the crystallization process of LDPE. The combined Avrami–Ozawa equation was used to describe the nonisothermal crystallization process. It was found that the combined Avrami–Ozawa method can successfully describe the nonisothermal crystallization process. The melting behavior indicates that the lamellar thickness distribution of the nanocomposites and microcomposites is not significantly changed in comparison with the neat LDPE. POLYM. ENG. SCI., 47:1052–1061, 2007. © 2007 Society of Plastics Engineers
High performance structured polymer barrier films obtained from compatibilized polypropylene/ethylene vinyl alcohol blends
Authors: Ait‐Kadi A. , Bousmina M. , Yousefi A.A. , Mighri F.
Published: May 2007

The effects of different functionalized polypropylene (PP) and diethyl maleate (DEM) combined with styrene–ethylene–butene–styrene copolymer (SEBS) on various properties of extruded‐stretched films of polypropylene/ethylene vinyl alcohol (PP/EVOH) blends were studied. The stretched films of the original PP/EVOH blends and those of the polymer‐g‐DEM modified blends showed lamellar‐type morphology, whereas their maleic anhydride (MAH) functionalized counterparts showed fibrillar morphology. Such peculiar morphology resulted in a dramatic decrease of oxygen permeability as compared with the unmodified or MAH modified PP/EVOH blends. These spectacular improvements in barrier properties were obtained without much altering thermal and mechanical properties of the blend. POLYM. ENG. SCI., 47:1114–1121, 2007. © 2007 Society of Plastics Engineers
Towards textile‐based fiber‐reinforced thermoplastic nanocomposites: Melt spun polypropylene‐montmorillonite nanocomposite fibers
Authors: Houphouët‐Boigny C. , Plummer C.J.G. , Wakeman M.D. , Månson J.‐A.E.
Published: May 2007

The present work is aimed at assessing the feasibility of integrating thermoplastic polypropylene nanocomposite matrices into conventional fiber‐reinforced composites based on hybrid textiles that incorporate both the matrix and glass‐fiber yarns, in order to reduce impregnation times. The focus is on the preparation and properties of the polypropylene nanocomposite fiber precursors and the implications for composite processing in general. However, preliminary results are also given that demonstrate satisfactory impregnation and consolidation of simple textiles produced byco‐weaving the nanocomposite yarns with glass‐fibers, given suitable processing conditions. POLYM. ENG. SCI., 47:1122–1132, 2007. © 2007 Society of Plastics Engineers
Control of polyaniline conductivity and contact angles by partial protonation
Authors: Blinova Natalia V , Stejskal Jaroslav , Trchová Miroslava , Prokeš Jan
Published: May 2007

Many studies require a specific value of conductivity when investigating conducting polymers. The conductivity of polyaniline can efficiently be controlled by partial protonation of the polyaniline base. Although this is a simple task in principle, practical guidelines are missing. In the present study, the changes in the conductivity of polyaniline base after immersion in aqueous solutions of various acids are reported. Polyaniline base has been reprotonated in aqueous solutions of picric, camphorsulfonic and phosphoric acids. The conductivity of partially reprotonated polyaniline varied between 10−9 and 100 S cm−1. The relation between the pH of a phosphoric acid solution, which was in equilibrium with polyaniline, and the conductivity σ is pH = 0.77 − 0.64 log(σ [S cm−1]). The wettability, i.e. water contact angles, can similarly be set by partial protonation to between 78° for polyaniline base and 44° for polyaniline reprotonated in 1 mol L−1 phosphoric acid. In solutions of picric acid, the transition from the non‐conducting to the conducting state occurs over a narrow range of acid concentrations, and the tuning of conductivity is consequently difficult. Phosphoric acid is well suited for the control of conductivity of polyaniline because of the moderate dependence of the conductivity on the acid concentration or pH. Copyright © 2007 Society of Chemical Industry
Electrospinning functional nanoscale fibers: a perspective for the future
Authors: Hunley Matthew T , Long Timothy E
Published: May 2007

Over the past decade, electrospinning has grown from a small niche process to a widely used fiber formation technique. Applying a strong electric potential on a polymer solution or melt produces nanoscale fibers. These nanofibers form non‐woven textile mats, oriented fibrous bundles and even three‐dimensional structured scaffolds, all with large surface areas and high porosity. Major applications of electrospun membranes include tissue engineering, controlled drug delivery, sensing, separations, filtration, catalysis and nanowires. This perspective article highlights many recent advances in electrospun fibers for functional applications, with an emphasis on the advantages and proposed technologies for these non‐woven fibrous scaffolds. Copyright © 2007 Society of Chemical Industry
Explaining inconsistent results in cancer quality of life studies: the role of the stress–response system
Authors: van de Wiel Harry , Geerts Erwin , Hoekstra‐Weebers Josette
Published: May 2007

This study tests the hypothesis that avoidance and intrusion play different roles in health‐related quality of life (QoL) in women who have undergone breast cancer surgery. We assessed QoL (RAND‐36), avoidance, intrusion, and total cancer‐related distress (Impact of Event Scale) in 83 women at 3, 6, 9, and 12 months after mastectomy. Social functioning and role limitations improved over time; physical functioning, general health, and mental health did not change; vitality initially improved followed by a decrease to a below initial level; physical pain initially improved followed by a decrease to an above initial level. Cancer‐related distress remained high during follow‐up. Individual variation in QoL as assessed across the four measurement times was associated with individual variation in intrusion but not with individual variation in avoidance. Baseline intrusion did not predict the subsequent course of QoL but high initial avoidance was associated with an unfavourable time course in physical functioning, social functioning, and general health. Hence, variation in intrusion over time explains variation in QoL while baseline avoidance predicts the subsequent course of QoL. The findings provide new insight into the relationship between the stress–response system in QoL and women with breast cancer. Copyright © 2007 John Wiley & Sons, Ltd.
Application of Seeding as a Process Actuator in a Model Predictive Control Framework for Fed‐Batch Crystallization of Ammonium Sulphate
Authors: Kalbasenka Alex N. , Spierings Lukas C. P. , Huesman Adrie E. M. , Kramer Herman J. M.
Published: May 2007

Seeding is discussed from the viewpoint of reproducible process actuation. Seeded experiments in a 75‐l Draft‐Tube (DT) crystallizer were performed in triplicate to verify reproducibility of the product characteristics. The seeded experiments displayed a significantly improved reproducibility of the results in comparison with the corresponding unseeded batches.

Narrow sieve fractions of ground seeds were utilized as a seeding material. The seeds were suspended in a saturated solution before being fed into the crystallizer. It was found that the Crystal Size Distribution (CSD) of crystals suspended in a saturated solution changed during the time of their residence in the seeding vessel. Images taken by the Scanning Electron Microscope (SEM) confirmed that the initial change in the median size was caused by the dissolution of fines. The dissolution was subsequently accompanied by the crystal growth and attrition. An optimal residence time was found.

Finally, the influence of the initial supersaturation, the seed load, and the seed size on the product quality was investigated. The experimental studies indicated that the initial supersaturation should be as high as possible yet not high enough to trigger primary nucleation. The lowest admissible sieve fraction and the corresponding minimal seed load were found. The conservatism of the used seeding model with respect to the minimal seed load was addressed.
Agglomerate TiO2 Aerosol Dynamics at High Concentrations
Authors: Heine Martin C. , Pratsinis Sotiris E.
Published: May 2007

Primary and agglomerate particle dynamics are investigated for aerosol synthesis of titania at high solids concentrations that are typically used for its industrial scale manufacture. Particle formation and growth are simulated accounting for chemical reaction, coagulation and sintering. Process conditions are chosen so that the resulting primary and hard‐agglomerate sizes are comparable with commercial product specifications. Neglecting aerosol polydispersity, the evolution of the diameter of primary particles, hard‐ and soft‐agglomerates along with the agglomerate effective volume fraction are investigated. During synthesis of nanostructured titania (e.g. for catalysts and cosmetics) the effective soft‐agglomerate volume fraction can exceed 30% within 100 s residence time indicating that a transition takes place from dilute to concentrated aerosol dynamics. At these conditions, classic Smoluchowski theory may no longer describe agglomerate coagulation and particles may affect fluid flow and heat transfer in industrial aerosol reactors. Furthermore, this could lead to restructuring and fragmentation of the product powder.
Mites for the control of pests in protected cultivation
Authors: Gerson Uri , Weintraub Phyllis G
Published: May 2007

The production of crops under protected conditions is increasing worldwide. Owing to growing consumer demands for healthy and green produce, and intensifying pesticide resistance, non‐chemical solutions—foremost among which is biological control—are being sought. The authors review recent advances related to the application of predatory mites for the control of greenhouse pests, and discuss interactions among acarine biocontrol agents (ABAs) and the effects of crop plants and new technologies on ABAs, such as artificial lighting, elevated carbon dioxide levels and genetically modified organisms. This is followed by a discussion of the problems associated with the search for and use of new ABAs, including management, the benefits of modelling and avenues of future research. Copyright © 2007 Society of Chemical Industry
Medicinal plants used by the people of Northeast India for curing malaria
Authors: Bora Utpal , Sahu Abhishek , Saikia Abinash Pratim , Ryakala Venkat Kishore , Goswami Pranab
Published: May 2007

The present study showed that the people of the Northeastern region of India use at least 65 plants belonging to 38 families to treat malaria. Different plant parts such as the leaf, root, bark and fruit and in some cases the whole plant were used for making the herbal preparations. All crude preparations were made using water as the medium. The preparations were orally administered either as a plant crude extract, juice and decoction or leaf infusion. Of the 65 plants, 21 were found to be used in the form of a decoction. The hard parts of the herbs such as the root and bark were taken in the form of a decoction. In some cases the ingredients of the herbal preparation also included honey or sugar. The present investigation also indicated that most of the preparations made for curing malaria were derived from single plant sources. Copyright © 2007 John Wiley & Sons, Ltd.
Statistical monitoring of nonlinear product and process quality profiles
Authors: Williams James D. , Woodall William H. , Birch Jeffrey B.
Published: May 2007

In many quality control applications, use of a single (or several distinct) quality characteristic(s) is insufficient to characterize the quality of a produced item. In an increasing number of cases, a response curve (profile) is required. Such profiles can frequently be modeled using linear or nonlinear regression models. In recent research others have developed multivariate T2 control charts and other methods for monitoring the coefficients in a simple linear regression model of a profile. However, little work has been done to address the monitoring of profiles that can be represented by a parametric nonlinear regression model. Here we extend the use of the T2 control chart to monitor the coefficients resulting from a parametric nonlinear regression model fit to profile data. We give three general approaches to the formulation of the T2 statistics and determination of the associated upper control limits for Phase I applications. We also consider the use of non‐parametric regression methods and the use of metrics to measure deviations from a baseline profile. These approaches are illustrated using the vertical board density profile data presented in Walker and Wright (Comparing curves using additive models. Journal of Quality Technology 2002; 34:118–129). Copyright © 2007 John Wiley & Sons, Ltd.
A systematic study of carboxylic acids in negative ion mode electrospray ionisation mass spectrometry providing a structural model for ion suppression
Authors: Clifford Mike N. , Lopez Violeta , Poquet Laure , Williamson Gary , Kuhnert Nikolai
Published: May 2007

We report a systematic investigation of the effects and structural requirements for ion suppression in negative ion mode electrospray ionisation mass spectrometry of a series of carboxylic acids and present a structural model rationalising ion suppression effects. Copyright © 2007 John Wiley & Sons, Ltd.
An electrospray ionisation tandem mass spectrometric investigation of selected psychoactive pharmaceuticals and its application in drug and metabolite profiling by liquid chromatography/electrospray ionisation tandem mass spectrometry
Authors: Doherty Bernadette , Rodriguez Virginia , Leslie Julian C. , McClean Stephen , Smyth W. Franklin
Published: May 2007

A tandem mass spectrometric investigation of the collision‐induced dissociation of five commonly prescribed psychoactive pharmaceuticals, risperidone, sertraline, paroxetine, trimipramine, and mirtazapine, and their metabolites has been carried out. Quadrupole ion trap mass spectrometry was employed to generate tandem mass spectrometric (MS/MS) data of the compounds under investigation and structural assignments of product ions were supported by quadrupole time‐of‐flight mass spectrometry. These fragmentation studies were then utilised in the development of a liquid chromatographic method to identify the drugs and their metabolites in human hair and saliva samples, thus providing relevant profiling information. Copyright © 2007 John Wiley & Sons, Ltd.
Continuous monitoring of long‐term outcomes with application to hip prostheses
Authors: Hardoon Sarah L. , Lewsey James D. , van der Meulen Jan H. P.
Published: May 2007

The CUSUM continuous monitoring method could be a valuable tool in evaluating the performance (revision experience) of prostheses used in hip replacement surgery. The dilemma when applying the CUSUM in this context is the choice of statistical model for the outcome (revision). The Bernoulli model is perhaps the most straightforward approach but the Poisson model is a plausible, and could be argued, preferable alternative for long‐term outcomes such as this, provided the rate of revision with time from surgery can be assumed to be constant. However, a rate (or hazard) varying according to the Weibull distribution appears to be a better representation of a prosthesis lifetime. We show how to adapt the Poisson approach to allow for the hazard to vary according to the Weibull model as well as other parametric survival models.
Application to data on a known poorly performing prosthesis shows both the Poisson and Weibull CUSUMs could have given early warning of the poor performance, with the Weibull chart alerting before the Poisson. Simulation work to investigate the robustness of the Poisson and Weibull CUSUM to departures from the underlying survival model highlights the need for correct specification of the model for the outcome. Copyright © 2007 John Wiley & Sons, Ltd.
An efficient and flexible toolkit for composing customized method dispatchers
Authors: Cunei A. , Vitek J.
Published: May 2007

The standard dispatching mechanisms built into programming languages sometimes fail to satisfy the needs of the programmer. In the case of Java, the need for more flexibility has led to the development of a number of tools, including visitors and multi‐method extensions, that each add some particular functionality, but lack the generality necessary to support user‐defined dispatching mechanisms. In this paper we advocate a more modular approach to dispatching, and we present a tool, PolyD, that allows the programmer to design custom dispatching strategies and to parametrize many aspects of the dispatching process. PolyD exhibits excellent performance and compares well against existing tools. Copyright © 2007 John Wiley & Sons, Ltd.
Simplifying dynamic programming via mode‐directed tabling
Authors: Guo Hai‐Feng , Gupta Gopal
Published: May 2007

In the dynamic programming paradigm the value of an optimal solution is recursively defined in terms of optimal solutions to subproblems. Such dynamic programming definitions can be tricky and error‐prone to specify. This paper presents an elegant method based on tabled logic programming (TLP) that simplifies the specification of such dynamic programming solutions. Our method introduces a new mode declaration for tabled predicates. The arguments of each tabled predicate are divided into indexed and non‐indexed arguments so that tabled predicates can be regarded as functions: indexed arguments represent input values and non‐indexed arguments represent output values. The non‐indexed arguments in a tabled predicate can be further declared to be aggregated, for example, the minimum, so that while generating answers, the global table will dynamically maintain the smallest value for that argument. This mode‐declaration scheme, coupled with recursion, provides an easy‐to‐use method for dynamic programming: there is no need to define the value of an optimal solution recursively, as the definition of a general solution suffices. The optimal value as well as its corresponding concrete solution can be derived implicitly and automatically using tabled logic programming systems. Our experimental results show that mode declarations improve performance in solving dynamic programming problems on TLP systems. Copyright © 2007 John Wiley & Sons, Ltd.
Metabolic footprinting as a tool for discriminating between brewing yeasts
Authors: Pope Georgina A. , MacKenzie Donald A. , Defernez Marianne , Aroso Miguel A. M. M. , Fuller Linda J. , Mellon Fred A. , Dunn Warwick B. , Brown Marie , Goodacre Royston , Kell Douglas B. , Marvin Marcus E. , Louis Edward J , Roberts Ian N.
Published: May 2007

The characterization of industrial yeast strains by examining their metabolic footprints (exometabolomes) was investigated and compared to genome‐based discriminatory methods. A group of nine industrial brewing yeasts was studied by comparing their metabolic footprints, genetic fingerprints and comparative genomic hybridization profiles. Metabolic footprinting was carried out by both direct injection mass spectrometry (DIMS) and gas chromatography time‐of‐flight mass spectrometry (GC–TOF–MS), with data analysed by principal components analysis (PCA) and canonical variates analysis (CVA). The genomic profiles of the nine yeasts were compared by PCR–restriction fragment length polymorphism (PCR–RFLP) analysis, genetic fingerprinting using amplified fragment length polymorphism (AFLP) analysis and microarray comparative genome hybridizations (CGH). Metabolomic and genomic analysis comparison of the nine brewing yeasts identified metabolomics as a powerful tool in separating genotypically and phenotypically similar strains. For some strains discrimination not achieved genomically was observed metabolomically. Copyright © 2007 John Wiley & Sons, Ltd.
Bimolecular fluorescence complementation analysis system for in vivo detection of protein–protein interaction in Saccharomyces cerevisiae
Authors: Sung Min‐Kyung , Huh Won‐Ki
Published: May 2007

The bimolecular fluorescence complementation (BiFC) assay has been widely accepted for studying in vivo detection of protein–protein interactions in several organisms. To facilitate the application of the BiFC assay to yeast research, we have created a series of plasmids that allow single‐step, PCR‐based C‐ or N‐terminal tagging of yeast proteins with yellow fluorescent protein fragments for BiFC assay. By examination of several interacting proteins (Sis1–Sis1, Net1–Sir2, Cet1–Cet1 and Pho2–Pho4), we demonstrate that the BiFC assay can be used to reliably analyse the occurrence and subcellular localization of protein–protein interactions in living yeast cells. The sequences for the described plasmids were submitted to the GenBank under Accession Nos: EF210802, pFA6a‐VN‐His3MX6; EF210803, pFA6a‐VC‐His3MX6; EF210804, pFA6a‐VN‐TRP1; EF210807, pFA6a‐VC‐TRP1; EF210808, pFA6a‐VN‐kanMX6; EF210809, pFA6a‐VC‐kanMX6; EF210810, pFA6a‐His3MX6‐PGAL1‐VN; EF210805, pFA6a‐His3MX6‐PGAL1‐VC; EF210806, pFA6a‐TRP1‐PGAL1‐VN; EF210811, pFA6a‐TRP1‐PGAL1‐VC; EF210812, pFA6a‐kanMX6‐PGAL1‐VN; EF210813, pFA6a‐kanMX6‐PGAL1‐VC; EF521883, pFA6a‐His3MX6‐PCET1‐VN; EF521884, pFA6a‐His3MX6‐PCET1‐VC; EF521885, pFA6a‐TRP1‐PCET1‐VN; EF521886, pFA6a‐TRP1‐PCET1‐VC; EF521887, pFA6a‐kanMX6‐PCET1‐VN; EF521888, pFA6a‐kanMX6‐PCET1‐VC. Copyright © 2007 John Wiley & Sons, Ltd.
Asymptotische Integration der Störungsdifferentialgleichung ebener laminarer Strömungen bei hohen Reynoldsschen Zahlen
Authors: Tollmien W.
Published: May 2007

Die Untersuchung der Stabilität einer Laminarströmung nach der Methode der kleinen Schwingungen führt auf eine gewöhnliche, nicht selbstadjungierte Differentialgleichung vierter Ordnung, die asymptotisch für große Reynoldssche Zahlen integriert werden soll. In Anlehnung an gebräuchliche Ansätze werden vier Näherungsintegrale dieser Differentialgleichung definiert und ihre Fehler sowie die ihrer Ableitungen asymptotisch abgeschätzt. Einige Bemerkungen zu dem Randwertproblem und zur Störungsdifferentialgleichung, falls die Grundströmung eine Grenzschichtströmung ist, werden angeschlossen.
Übergang zu Chaos in einfachen mechanischen Systemen
Authors: Lindtner E. , Seisl M. , Steindl A. , Troger H.
Published: May 2007

In dieser Arbeit wird chaotisches Systemverhalten im Sinne zeitlich irregulären Verhaltens unter Bewahrung einer geordneten räumlichen Struktur untersucht. Wegen des Fehlens eines generischen Übergangs von der geordneten Systembewegung zum chaotischen Bewegungszustand haben sich im wesentlichen folgende drei Szenarien zur Klassifikation der im Experiment gefundenen Phänomene ergeben: (i) Ruelle‐Takens‐Newhouse Szenario, (ii) Feigenbaum‐ oder Periodenverdopplungsszenario und (iii) der Pomeau‐Manneville‐ oder intermittierende Übergang. An zwei einfachen Beispielen wird gezeigt, daß alle drei angeführten Übergangsszenarien bei Variation geeigneter Parameter auftreten können.
On the Elastic‐plastic Shrink Fit Rotating with Supercritical Angular Speed
Authors: Gamer U. , Orčan Y.
Published: May 2007

Unter Zugrundelegung der Trescaschen Fließbedingung und der zugeordneten Fließregel wird die Verteilung von Spannungen und Verschiebung in der vollplastizierten Nabe eines rotierenden Preßverbandes untersucht. Das Nabenmaterial weist lineare Verfestigung auf. Bei der kritischen Winkelgeschwindigkeit kommt es zu einem Wechsel des Tresca‐Regimes.
Error Estimates of an Euler Method for a Quasistatic Elastic‐Visco‐Plastic Problem
Authors: Ionescu I. R.
Published: May 2007

An initial and boundary value problem for a rate type elastic‐visco‐plastic material is considered. An Euler method as well as internal and external approximation techniques are used in order to obtain the numerical solution of the problem. The error is estimated over a finite time interval. In the viscoelastic case the error is estimated over an infinite time interval provided that the time step is less than a critical value. A one dimensional numerical example is successfully integrated using this numerical approach and a finite element technique.
Noise Induced Rotation
Authors: Wihstutz V.
Published: May 2007

We investigate the impact of noisy restoring force on the damped linear oscillator z̈ + 2βż + cz = 0, when interplaying with the damping. Besides describing the strength of destabilizing and stabilizing noise effects, we show the phenomenon of noise induced oscillation (or rotation) and estimate its strength.
Entwurf eines nichtlinearen Laufmustergenerators
Authors: Frik M. , Ahanikamangar M.
Published: May 2007

Es wird eine Methode zum Entwurf eines Laufmustergenerators vorgestellt, der bei Gehmaschinen zur Realisierung von Gehbewegungen verwendet werden kann. Der Laufmustergenerator wird modular aus gekoppelten Van der Pol Schwingern aufgebaut, deren Schwingungen den Bewegungen der einzelnen Glieder des Gehapparates entsprechen. Die Parameter und Koppelkoeffizienten werden so bestimmt, daß die rhythmischen, synchronisierten Bewegungen, die der gewünschten Gangart entsprechen, entstehen.
Periodic Solutions of a Pendulum‐like Integrodifferential Equation with Infinite Retardation Describing Josephson Tunneling
Authors: Zurbrügg Ch.
Published: May 2007

Wenn man die Dynamik eines stromgesteuerten Josephson‐Tunnel‐Kontaktes auf der Basis der Werthamertheorie beschreibt, ergibt sich eine autonome Integrodifferentialgleichung mit unendlicher Retardierung, die man als verallgemeinerte Pendelgleichung ansehen kann. In dieser Arbeit wird ein Beweis für die Existenz von periodischen Lösungen zweiter Art (Rotationslösungen) vorgestellt. Der Beweis beruht auf einem Lerary‐Schauder Argument. Weiter wird ein spezieller Fall der nichtautonomen Gleichung behandelt. Die Arbeit enthält auch Ergebnisse numerischer Berechnungen der Rotationslösungen.
Histogramme, Orientierungsdichtefunktionen und ihre Darstellung durch eine tensorielle Form der Fourierreihe
Authors: Seibert D.
Published: May 2007

Die Orientierung innerer Werkstoffstrukturen, wie etwa Fasern in Verbundwerkstoffen, kann durch Histogramme und Orientierungsdichtefunktionen (ODF) beschrieben werden. ODF sind auf dem Einheitskreis oder der Einheitskugel definierte, reellwertige Funktionen und können durch Fourierreihen dargestellt werden. In diesem Aufsatz wird Onats Arbeit [3] über vom Koordinatensystem unabhängige Fourierreihen, deren Fourierkoeffizienten und Basisfunktionen irreduzible Tensoren sind, vervollständigt.
Über die Sensibilität von Eigenwerten und Eigenvektoren
Authors: Kuhnert F
Published: May 2007

Betrachtet werden allgemeine Eigenwertaufgaben mit parameterabhängigen Matrizen. Sensibilitätsanalyse bedeutet Untersuchung des Einflusses dieser Parameter auf die Eigendaten. Für die Eigenwerte werden lineare und quadratische Glieder angegeben. Untersucht werden auch iterative Verfahren für inverse Aufgaben, die entstehen, wenn einzelne Eigenwerte vorgegeben werden und die entsprechenden Parameter zu identifizieren sind.