bluuebunny/crossref_metadata_2025 huggingface dataset:
Criteria for neuropathic abnormality in quantitative anal sphincter electromyography
Authors: Podnar Simon
Published: September 2004

For the external anal sphincter muscle, both normative values and an optimal set of motor unit potential (MUP) parameters have been defined. However, criteria for the diagnosis of neuropathic conditions have not yet been validated. Therefore, in this study, sensitivity was examined in 86 patients with cauda equina lesions (227 muscles), and specificity in 77 controls (119 muscles), using multi‐MUP analysis. Six previously defined diagnostic criteria (mean values and outliers for MUP area, duration, and number of turns) were used. An increase in the number of diagnostic criteria required for muscle abnormality (two and three instead of one), and the application of more stringent normative limits resulted in a progressive increase in specificity from 74% to 99% (controls), and a decrease in sensitivity from 70% to 21% (patients). The data suggest that no single cut‐off diagnostic criterion has both satisfactory sensitivity and specificity. Introduction of the diagnostic categories of “possible,” “probable,” and “definite” neuropathic abnormalities into quantitative electromyographic analysis is proposed. Muscle Nerve, 2004
Differences between young and older women in maximal force, force fluctuations, and surface emg during isometric knee extension and elbow flexion
Authors: Bazzucchi Ilenia , Felici Francesco , Macaluso Andrea , De Vito Giuseppe
Published: September 2004

The loss of muscle strength with aging appears to be greater in the lower than upper limbs, but strength and its neural control have never been compared in the same population of individuals in both upper and lower limbs. The aim of this study was to investigate differences between eight young (20–31 years) and eight older (68–76 years) healthy women in maximal voluntary contraction (MVC), force fluctuations, median frequency (MDF) of the surface electromyogram (sEMG), and muscle fiber conduction velocity (MFCV) during sustained isometric elbow flexion (EF) and knee extension (KE), performed at moderate to high force intensity. Older women showed larger fluctuations of force with endurance and changes in sEMG pointing to less fatigue, especially at high level of force, with no differences between upper and lower extremities. This may have significant implications in the design of rehabilitation programs directed to this population. Muscle Nerve, 2004
Involvement of skeletal muscle in dialysis‐associated systemic fibrosis (nephrogenic fibrosing dermopathy)
Authors: Levine Joshua M. , Taylor Robert A. , Elman Lauren B. , Bird Shawn J. , Lavi Ehud , Stolzenberg Ethan D. , McGarvey Michael L. , Asbury Arthur K. , Jimenez Sergio A.
Published: September 2004

Nephrogenic fibrosing dermopathy (NFD), a newly recognized scleroderma‐like disease, was originally described as a purely cutaneous disorder. More widespread involvement, including fibrosis of pulmonary and cardiac tissues, has been documented only recently, and it has been suggested that a more appropriate designation is dialysis‐associated systemic fibrosis. We report five cases of this novel disorder, spanning a spectrum of primarily skin to primarily muscle involvement. Clinical, radiological, electrophysiological, and pathological studies revealed moderate to severe fibrosis of striated muscles. All patients had end‐stage renal failure on chronic dialysis, subacute to chronic hardening of the skin and muscles, restriction of limb movements with joint contractures, but normal to only mildly weak muscle strength. Limitation of movements was caused predominantly by skin tightness and induration, and by joint contractures rather than muscle weakness. Computerized tomography showed fibrosis of the fascia and muscles in the most severely affected patients, and electromyography showed mild to severe myopathic changes. Histopathology of affected muscles revealed a spectrum of mild to severe fibrosis, degenerating fibers, and chronic inflammatory cells. These results further support the contention that NFD is not a purely cutaneous disease, but is part of a larger systemic fibrotic process that may involve muscles. Muscle Nerve, 2004
Radio frequency continuous‐wave and time‐domain EPR imaging and Overhauser‐enhanced magnetic resonance imaging of small animals: instrumental developments and comparison of relative merits for functional imaging
Authors: Subramanian Sankaran , Matsumoto Ken‐ichiro , Mitchell James B. , Krishna Murali C.
Published: September 2004

Electron paramagnetic resonance (EPR) imaging in the continuous wave (CW) and time‐domain modes, as well as Overhauser‐enhanced magnetic resonance imagingin vivois described. The review is based mainly on the CW and time‐domain EPR instrumentation at 300 MHz developed in our laboratory, and the relative merits of these methods for functionalin vivoimaging of small animals to assess hypoxia and tissue redox status are described. Overhauser imaging of small animals at magnetic fields in the range 10–15 mT that is being carried out in our laboratory for tumor imaging and the evaluation of tumor hypoxia based on quantitative evaluation of Overhauser enhancement is also described. Alternate approaches to spectral–spatial imaging using the transverse decay constants to inferin situline widths and hencein vivopO2using CW and time‐domain EPR imaging are also discussed. The nature of the spin probes used, the quality of the images obtained in all the three methods, the achievable resolution, limitations and possible future directions in small animal functional imaging with these modalities are summarized. Copyright © 2004 John Wiley & Sons, Ltd.
Application of in vivo EPR in brain research: monitoring tissue oxygenation, blood flow, and oxidative stress
Authors: Liu Shimin , Timmins Graham S. , Shi Honglian , Gasparovic Charles M. , Liu Ke Jian
Published: September 2004

Although oxygen levels are critical to tissue survival, monitoring tissue oxygen levels in vivo, in real time, remains a technical challenge. This is especially so for repetitive measurements in non‐superficial tissue. There currently exist several techniques that can be utilized for tissue oxygen measurement, but technical difficulties have limited their usefulness and general application. Here we describe a relatively new method, electron paramagnetic resonance (EPR) oximetry, for in vivo measurement of brain tissue oxygen, as well as information on blood flow and oxidative stress. In this paper we report experiments designed to assess and illustrate the effectiveness of this new method. Using the unique capability of this approach, we have measured both absolute values and temporal changes of pO2 in ischemic penumbra and core during cerebral ischemia and reperfusion in a rat model. EPR oximetry with particulate probe sensitively reflected differential changes in oxygenation in the core and penumbra during ischemia, reperfusion and also hyperoxic conditions. Simultaneous two‐site detection with particulate probes was also obtained with good spatial resolution. Additionally, EPR measurement of oxidative stress, EPR imaging of brain with nitroxide and triarylmethyl soluble probes are also described. These results demonstrate that EPR oximetry with particulate probe can provide accurate and reproducible measurements of localized pO2 in the brain, and it is a versatile and useful method in the measurement of tissue pO2 under a variety of physiological and pathophysiological conditions. Copyright © 2004 John Wiley & Sons, Ltd.
Development and evaluation of biocompatible inks for the local measurement of oxygen using in vivo EPR
Authors: Charlier Nicolas , Beghein Nelson , Gallez Bernard
Published: September 2004

In vivo EPR oximetry is a powerful minimally invasive method that allows the measurement of oxygen in tissues through the use of a paramagnetic probe. In the present study, we investigated new strategies for preparing biocompatible inks containing carbon black particles (Printex U), which could be used as oxygen sensors. The carbon black particles were dispersed in solutions of biocompatible polymers of carboxy methyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC) or polyvinyl pyrrolidone (PVP). A total of 12 polymers with different molecular weights were tested. A physico‐chemical characterization of the inks was carried out to assess the sedimentation of the particles, the rheological behavior of these inks, and the relative diffusion of the inks. The preparations with CMC and PVP had the highest viscosity and stability. The presence of the polymers did not modify the calibration curves (EPR linewidth as a function of the pO2) of the carbon black. In vivo, the oxygen sensors were stable for at least one month in muscles as the EPR linewidth remained fully sensitive to induced ischemia or carbogen challenge. The calibration curve was not modified after this period of implantation. A first study of biocompatibility was carried out in vitro (hemolysis and cytotoxicity assay) and in vivo (histological examination). No sign of toxicity was observed using these inks. These preparations are good candidates for future in vivo studies including clinical trials. Copyright © 2004 John Wiley & Sons, Ltd.
Cardiac applications of EPR imaging
Authors: Kuppusamy Periannan , Zweier Jay L.
Published: September 2004

This review summarizes the development and application of a variety of EPR imaging modalities including spatial, spectral–spatial (spectroscopic), gated‐imaging and oxygen mapping to cardiovascular studies. It has been hypothesized that free radical metabolism, oxygenation and nitric oxide generation in biological organs such as the heart may vary over the spatially defined tissue structure. We have developed instrumentation optimized for 3D spatial and 3D or 4D spectral–spatial imaging of free radicals at 1.2 GHz. Using this instrumentation high quality 3D spectral–spatial imaging of nitroxyl (nitroxide) metabolism was performed, as well as spatially localized measurements of oxygen concentrations, based on the oxygen‐dependent line‐broadening of the EPR spectrum. Both exogenously infused probes and endogenous radicals were used to obtain the images. It is demonstrated that the EPR imaging is a powerful tool which can provide unique information regarding the spatial localization of free radicals, oxygen and nitric oxide in biological organs and tissues. Copyright © 2004 John Wiley & Sons, Ltd.
In vivo EPR: when, how and why?
Authors: Gallez Bernard , Swartz Harold M.
Published: September 2004

This special issue is aimed at providing the readers of this journal with an indication of the exciting and important areas in which in vivo electron paramagnetic resonance (EPR) [or equivalently electron spin resonance (ESR)] is making contributions to experimental progress and to provide perspectives on future developments, including the potential for in vivo EPR to be an important new clinical tool. There also are many situations where the combination of in vivo EPR with NMR may be very synergistic. EPR (ESR) is a magnetic resonance‐based technique that detects species with unpaired electrons. The technique has become a major tool in diverse fields ranging from biology and chemistry to solid‐state physics. In the last few years, many publications have demonstrated that EPR measurements in living animals (in vivo EPR) can provide very significant new insights to physiology, pathophysiology and pharmacology. The most successful applications of in vivo EPR have been non‐invasive measurements of oxygen, nitric oxide, bioradicals, pH and redox state, with applications in oncology, cardiology, neuroscience and toxicology. EPR also appears to be the method of choice for measuring radiation dose retrospectively, including the potential to do this in vivo in human subjects. While far from comprehensive, the reviews, original contributions and viewpoints provided in this issue by several leaders in the field of in vivo EPR should provide the readers with confirmation that in vivo EPR is an exciting field that is likely to provide very valuable complementary information for many NMR‐based studies in experimental animals and, probably, also for clinical studies. Copyright © 2004 John Wiley & Sons, Ltd.
Constant amplitude of postsynaptic responses for single presynaptic action potentials but not bursting input during growth of an identified neuromuscular junction in the lobster, Homarus americanus
Authors: Pulver Stefan R. , Bucher Dirk , Simon David J. , Marder Eve
Published: September 2004

As lobsters grow from early juveniles to adults their body size increases more than 20‐fold, raising the question of how function is maintained during these ongoing changes in size. To address this question we studied the pyloric 1 (p1) muscle of the stomach of the lobster, Homarus americanus. The p1 muscle receives multiterminal innervation from one motor neuron, the lateral pyloric neuron of the stomatogastric ganglion. Staining with antibodies raised against synaptotagmin showed that as the muscle fibers increased in length, the spacing between the terminal innervation increased proportionally, so the number of synaptic contact regions/muscle fiber did not change. Muscle fibers were electrically coupled in both juveniles and adults. The amplitude of single intracellularly recorded excitatory junctional potentials evoked by motor nerve stimulation was the same in both juveniles and adults. Nonetheless, the peak depolarizations reached in response to ongoing pyloric rhythm activity or in response to high‐frequency trains of stimuli similar to those produced during the pyloric rhythm were approximately twofold larger in juveniles than in adults. This suggests that homeostatic regulation of synaptic connections may operate at the level of the amplitude of the single synaptic potential rather than on the summed depolarization evoked during strong rhythmic activity. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2005
Complementary neural systems for the experience‐dependent integration of mate‐choice cues in European starlings
Authors: Sockman Keith W. , Gentner Timothy Q. , Ball Gregory F.
Published: September 2004

Choice of a particular mate phenotype may arise out of experience with the very phenotypes under consideration. Female European starlings (Sturnus vulgaris) prefer males that sing predominantly long‐bout songs over males that sing predominantly short‐bout songs, and thus, song‐bout length is a phenotypic parameter instrumental in releasing the female's mate choice. The preferred long‐bout songs induce higher expression of the immediate early gene (IEG) ZENK in the female auditory telencephalon than short‐bout songs do, but this sensitivity to song length depends on the female's recent song experience. Here, we compared the experience‐dependent modulation of ZENK with that of another IEG, FOS, and report that ZENK and FOS expression in the caudomedial mesopallium and caudomedial nidopallium show different modulation properties that complement natural variation in song‐bout length. As reported previously, ZENK expression was greater in response to novel long‐bout than to novel short‐bout songs following a 1‐week experience with long‐bout but not short‐bout songs. In contrast, FOS expression was greater in response to novel long‐bout than to novel short‐bout songs following a 1‐week experience with short‐bout but not long‐bout songs. Thus, the ZENK and FOS signaling pathways are made sensitive to variation in song length by experiences with songs at opposite ends of the starling song‐variation continuum, suggesting the presence of complementary neural systems made sensitive in register with the natural axis of phenotypic variation fundamental to the female's mate choice. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2005
Thermosensation and pain
Authors: Tominaga Makoto , Caterina Michael J.
Published: September 2004

We feel a wide range of temperatures spanning from cold to heat. Within this range, temperatures over about 43°C and below about 15°C evoke not only a thermal sensation, but also a feeling of pain. In mammals, six thermosensitive ion channels have been reported, all of which belong to the TRP (transient receptor potential) superfamily. These include TRPV1 (VR1), TRPV2 (VRL‐1), TRPV3, TRPV4, TRPM8 (CMR1), and TRPA1 (ANKTM1). These channels exhibit distinct thermal activation thresholds (>43°C for TRPV1, >52°C for TRPV2, >∼34–38°C for TRPV3, >∼27–35°C for TRPV4, <∼25–28°C for TRPM8 and <17°C for TRPA1), and are expressed in primary sensory neurons as well as other tissues. The involvement of TRPV1 in thermal nociception has been demonstrated by multiple methods, including the analysis of TRPV1‐deficient mice. TRPV2, TRPM8, and TRPA1 are also very likely to be involved in thermal nociception, because their activation thresholds are within the noxious range of temperatures. © 2004 Wiley Periodicals, Inc. J Neurobiol 61: 3–12, 2004
Posttranslational mechanisms of peripheral sensitization
Authors: Bhave Gautam , Gereau Robert W.
Published: September 2004

The sensation of pain can be dramatically altered in response to injury or disease. This sensitization can occur at the level of the primary sensory neuron, and can be mediated by multiple biochemical mechanisms, including, but not limited to, changes in gene transcription, changes in translation, stability, or subcellular localization of translated proteins, and posttranslational modifications. This review focuses on posttranslational modifications to ion channels expressed in primary sensory neurons that form the machinery driving peripheral sensitization and pain hypersensitivity. Studies published to date show strong evidence for modulation of ion channels involved in transduction and transmission of nociceptive inputs coincident with biophysical and behavioral sensitization. The roles of phosphorylation and oxidation/reduction reactions of voltage‐dependent sodium, potassium, and calcium channels are discussed, as well as phosphorylation‐mediated modulation of sensory transduction channels. © 2004 Wiley Periodicals, Inc. J Neurobiol 61: 88–106, 2004
Jacobi–Davidson methods for cubic eigenvalue problems
Authors: Hwang Tsung‐Min , Lin Wen‐Wei , Liu Jinn‐Liang , Wang Weichung
Published: September 2004

Several Jacobi–Davidson type methods are proposed for computing interior eigenpairs of large‐scale cubic eigenvalue problems. To successively compute the eigenpairs, a novel explicit non‐equivalence deflation method with low‐rank updates is developed and analysed. Various techniques such as locking, search direction transformation, restarting, and preconditioning are incorporated into the methods to improve stability and efficiency. A semiconductor quantum dot model is given as an example to illustrate the cubic nature of the eigenvalue system resulting from the finite difference approximation. Numerical results of this model are given to demonstrate the convergence and effectiveness of the methods. Comparison results are also provided to indicate advantages and disadvantages among the various methods. Copyright © 2004 John Wiley & Sons, Ltd.
Outcomes of a program to enhance exercise self‐efficacy and improve fitness in black and hispanic college‐age women
Authors: D'Alonzo Karen T. , Stevenson Joanne S. , Davis Shala E.
Published: September 2004

A quasi‐experimental design was used to test the outcomes of an exercise program directed towards Black and Hispanic college‐age women. Forty‐four women (36 Black, 7 Hispanic, and 1 Black/Hispanic) attended exercise classes three times per week for 16 weeks. At program completion, women were classified as either high attendees (n = 26) or low attendees (n = 18). Compared to low attendees, the high attendees had significantly higher exercise self‐efficacy (p < .001), perceived benefits and barriers (p = .004), aerobic fitness, flexibility, muscle strength, and percentage of body fat (all p < .001). Daily activity levels improved significantly in the high attendance group following the program (p < .001) and at 8 weeks post‐program completion (p = .01). © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:357–369, 2004
Sonographic biometrical range of external genitalia differentiation in the first trimester of pregnancy: analysis of 2593 cases
Authors: Mazza V. , Di Monte I. , Pati M. , Contu G. , Ottolenghi C. , Forabosco A. , Volpe A.
Published: September 2004

Objectives

The aim of this study was to establish the accuracy of fetal gender assignment by sonography in the biometrical range of 18 to 29 mm of biparietal diameter (BPD).

Methods

Transvaginal and/or transabdominal sonography was used to detect the sagittal sign as a marker of fetal gender in 2593 fetuses with BPD between 18 and 29 mm. The results of sonographic examination were compared with the gender at birth or with karyotype obtained from amniotic fluid cells or chorionic villus sampling.

Results

Fetal gender assignment was feasible in 2374 of 2593 cases (91%). Of the 2188 fetuses with known fetal sex outcome, 1025 were males and 1157 were females, and 6 had genital anomalies. In fetuses without genital anomalies, an accuracy rate of 100% was achieved at a BPD of ≥24 mm. The results of the six cases with genital malformations were considered separately.

Conclusion

Sonography is a reliable method for the study of the morphological development of the external genitalia in fetuses ‘in vivo’; it is possible to assign fetal gender in 95 to 99% starting at a BPD of 20 mm and to achieve an accuracy rate of 99 to 100% from a BPD of 22 mm, but fetal sex assignment should not be undertaken below a BPD of 22 mm, and especially not in cases where fetal sexing affects pregnancy management. Copyright © 2004 John Wiley & Sons, Ltd.
β‐globin DNA in maternal plasma as a molecular marker of pre‐eclampsia
Authors: Sekizawa Akihiko , Farina Antonio , Koide Keiko , Iwasaki Mariko , Honma Susumi , Ichizuka Kiyotake , Saito Hiroshi , Okai Takashi
Published: September 2004

Objectives

Levels of cell‐free foetal DNA in maternal plasma are higher in the presence of clinical features of pre‐eclampsia (PE). However, currently, this method is informative only in women bearing a male foetus, by amplification of Y‐specific sequences. In the present study, we overcame this limitation by examining quantitative distribution of β‐globin, a foetal gender–independent DNA marker.

Methods

We quantified β‐globin concentrations in the plasma of 207 pregnant women: control group, 164 subjects; affected group, 43 women affected by PE (n = 43). β‐globin concentrations were converted into multiples of the median of the controls (MoM), in order to assess the possible different distribution of β‐globin MoM in cases and controls.

Results

Adjusted MoM values were as follows: controls, 1.00 ± 0.71; affected group 4.03 ± 3.77 (p‐value < 0.001). Among the PE affected cases, MoM β‐globin values of cases with foetal growth restriction (FGR) were almost twice as great as those cases without FGR (p‐value = 0.003).

Conclusion

β‐globin levels are higher in the plasma of pregnant women with PE, especially in those cases complicated with FGR, and do not depend on foetal gender. Such a molecular marker can potentially be used in evaluating the pathophysiological severity of PE. Copyright © 2004 John Wiley & Sons, Ltd.
The role of scientific evidence of risks and benefits in determining risk management policies for medications
Authors: Andrews Elizabeth , Dombeck Michael
Published: September 2004

Recent changes in the regulatory environment have called attention to the need for and potential benefits of greater and more detailed evidence to inform decisions based on the risk–benefit profile of medications. Nevertheless, access to potentially beneficial therapies continues to be impeded by a lack of sufficient information that could help optimize benefits and minimize risks of treatments for patients. Over‐reliance on pre‐marketing clinical trials and the FDA's spontaneous reporting adverse event system to support regulatory decisions has sustained an information void. Clinical trials are the gold standard for demonstrating efficacy, but they cannot fully predict safety when drugs are used in the real world. Spontaneous reporting can identify new signals, but cannot quantify those signals or place them in appropriate clinical context. In the face of new safety signals, absence of better information on how medications are used and how they perform in the real world setting, regulators are often limited to either continuing drug marketing without significant changes or withdrawing a medication from the market. Experience shows that information collected proactively, to better understand the background risks associated with the underlying disease and to better quantify the product risks, can influence these decisions to include a wider range of options regarding a product's availability, labeling and additional risk management strategies. This article presents several case studies of medications, including those in which insufficient data were available to address important safety signals and decisions were made to withdraw products, as well as those in which epidemiologic data were available to provide reassurance of product safety and allow continued product use, even though some may be marketed with additional risk management programs. More extensive and earlier epidemiologic assessment of risks and benefits of new products will create a new standard of evidence for industry and regulators and is likely to result in more effective and balanced regulatory actions, thereby affording better care for patients. Copyright © 2003 John Wiley & Sons, Ltd.
Dimerization mechanisms of heterocyclic carbenes
Authors: Graham David C. , Cavell Kingsley J. , Yates Brian F.
Published: September 2004

The dimerization reactions of a series of heterocyclic carbenes based on the 1,3‐dimethylimidazol‐2‐ylidene template were studied extensively using molecular orbital calculations. The carbenes studied were the 1,3‐XY five‐membered ring heterocyclic carbenes with all 10 possible combinations of X,Y = NCH3, PCH3, O and S. Two different mechanisms for dimerization were studied: a direct carbene plus carbene dimerization reaction and a proton‐catalysed dimerization. The parent carbene with XY = NN is found to be kinetically and thermodynamically stable under both mechanisms, whereas XY = NS is predicted to be kinetically stable under aprotic conditions. All remaining carbenes were predicted to be not particularly stable towards dimerization. Indirect schemes for calculating the stability of carbenes towards dimerization were found to give good estimates of the enthalpy of dimerization, but do not take into account the activation barriers. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of core‐shell poly(divinylbenzene) microspheres via reversible addition fragmentation chain transfer graft polymerization of styrene
Authors: Barner Leonie , Li Chao'En , Hao Xiaojuan , Stenzel Martina H. , Barner‐Kowollik Christopher , Davis Thomas P.
Published: September 2004

Styrene has been grafted from crosslinked poly(divinylbenzene) core microspheres by both reversible addition fragmentation chain transfer (RAFT) polymerization and conventional free radical polymerization. The core microspheres were prepared by precipitation polymerization. Crosslinked poly(DVB) core microspheres containing double bonds on the particle surface can be used directly to graft polymers from the surface by RAFT without prior modification of the core microspheres. The RAFT agent 1‐phenylethyl dithiobenzoate (PEDB) was used: Particle sizes increased from 2 μm up to 3.06 μm, and the particle weight increased by up to 6.5%. PEDB controls the particle weight gain, the particle volume, and the molecular weight of the soluble polymer. PEDB was also used to synthesize core poly(DVB) RAFT microspheres that contain residual RAFT end groups on the surface and within the particle. Styrene was subsequently grafted from the surface of these core poly(DVB) RAFT microspheres. The generated microspheres were characterized by 1H‐NMR spectroscopy, focused ion beam (FIB) milling, Coulter particle sizing, and size exclusion chromatography. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5067–5076, 2004
Selectivity in anionic and cationic ring‐opening polymerizations of tetramethyl‐1‐(3′‐trifluoromethylphenyl)‐1‐phenylcyclotrisiloxane and tetramethyl‐1‐[3′,5′‐bis(trifluoromethyl)phenyl]‐1‐phenylcyclotrisiloxane
Authors: Gädda Thomas M. , Nelson Allison K. , Weber William P.
Published: September 2004

Anionic and cationic ring‐opening polymerizations of two novel cyclotrisiloxanes, tetramethyl‐1‐(3′‐trifluoromethylphenyl)‐1‐phenylcyclotrisiloxane (I) and tetramethyl‐1‐[3′,5′‐bis(trifluoromethyl)phenyl]‐1‐phenylcyclotrisiloxane (II), are reported. Anionic ring‐opening polymerization of I or II leads to copolymers with highly regular microstructures. Copolymers obtained by cationic polymerizations of I or II, initiated by triflic acid, have less regular microstructures characteristic of chemoselective polymerization processes. The composition and microstructure of copolymers have been characterized by 1H and 29Si‐NMR, the molecular weight distributions by GPC, and the thermal properties by DSC and TGA. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5235–5243, 2004
Oxygen permeability in blends of a vinyl alcohol/ethylene copolymer and a metallocenic ethylene/1‐octene copolymer
Authors: Laguna M. F. , Cerrada M. L. , Benavente R. , Pérez E.
Published: September 2004

This work describes the preparation, characterization, and evaluation of the oxygen permeability of blends based on a polyolefin synthesized with a metallocene catalyst (ethylene/1‐octene copolymer) and a vinyl alcohol/ethylene copolymer in an attempt to establish the corresponding relationships between the composition, morphology, and transport properties to design materials with optimized and enhanced agricultural and food packaging performances. Moreover, microhardness measurements have been used to analyze the mechanical response of these blends and to obtain information about the dispersion of the two immiscible components within the blends. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3766–3774, 2004
A Grand Canonical Monte Carlo Study of Adsorption and Capillary Phenomena in Nanopores of Various Morphologies and Topologies: Testing the BET and BJH Characterization Methods
Authors: Coasne Benoit , Gubbins Keith E. , Pellenq Roland J.‐M.
Published: September 2004

We report a Grand Canonical Monte Carlo simulation study of Ar adsorption at 77 K in silica nanopores having various morphologies/topologies. Both the morphological and topological disorders are shown to significantly affect the capillary condensation phenomenon. In the case of an ellipsoidal pore, we observe that the filling mechanism is similar to that of a cylindrical pore having the same section area but with a lower condensation pressure. We show that the adsorption/desorption hysteresis loop is asymmetrical for the pore with constrictions while it is symmetrical for the regular cylindrical pore. Moreover, the Ar adsorption isotherm for the constricted pore reproduces the main features of that for the fully disordered Vycor‐like porous matrix. The results for the different pore geometries (having no direct interface with the gas reservoir) indicate that the desorption occurs through cavitation at a pressure driven by the smallest void size. We also consider the validity of the BET and BJH methods for the different porous matrices. Except for the Vycor‐like matrix, the BET surface assessed from Ar adsorption isotherm at 77 K always significantly overestimates the intrinsic surface of the pore (even for a planar surface). The disagreement between the BET surface and the geometrical surface is found to increase as the confinement increases (cylindrical pore) and/or the shape of the pore becomes asymmetrical (ellipsoidal pore). Interestingly, the best agreement between the BET and the geometrical surface is found in the case of the pore with a constriction, i.e. a system that exhibits a surface with both negative and positive curvature regions. This idea is supported by the results for the Vycor‐like matrix, which has a distorted surface (many negative curvature regions combined with positive curvature regions): for this disordered porous matrix, the BET surface is found to underestimate the intrinsic surface. Finally, we show that the pore size determined using the BJH method always underestimates the pore size, in agreement with previous experimental and simulation studies.
Peptides containing 4‐amino‐1,2‐dithiolane‐4‐carboxylic acid (Adt): conformation of Boc‐Adt‐Adt‐NHMe and NH ⃛S interactions
Authors: Morera Enrico , Nalli Marianna , Mollica Adriano , Paglialunga Paradisi Mario , Aschi Massimiliano , Gavuzzo Enrico , Mazza Fernando , Lucente Gino
Published: September 2004

To study the conformational preferences induced by the insertion of the 4‐amino‐1,2‐dithiolane‐4‐carboxylic acid (Adt) residue into a peptide backbone, the achiral N‐protected dipeptide methylamide Boc‐Adt‐Adt‐NHMe (1) was synthesized and its crystal state and solution conformation studied and compared with that exhibited by its carba‐analogue Boc‐Ac5c‐Ac5c‐NHMe containing two residues of 1‐aminocyclopentane‐1‐carboxylic acid (Ac5c). Compound 1 in the crystal adopts a type‐III β‐turn conformation and an analogous structure is that preferred in chloroform solution as established by 1H‐NMR and NOE information. In the crystal packing three different Adt rings form a cavity and the involved sulphur atoms give rise to unusual multiple interactions with one NH group. The chemical nature of these intermolecular and intramolecular main‐chain ⃛side‐chain NH ⃛S interactions are discussed in terms of quantum chemical calculations. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Optical and electrical properties of ZnO doped with nitrogen
Authors: Kang Seungmo , Shin Kyoungchul , Prabakar Kandasamy , Lee Chongmu
Published: September 2004

Ultraviolet (UV) and visible photoluminescence (PL) has been achieved at room temperature from ZnO films deposited on the sapphire substrate by RF‐magnetron sputtering. The electrical and optical properties of as‐deposited and annealed films were investigated as a function of N2O/Ar gas flow ratio. All the ZnO films deposited by sputtering show a typical hexagonal wurtzite crystallographic orientation with a c‐axis perpendicular to the substrate surface. The growth rate decreases with the increase of the gas flow ratio. The high carrier mobility and low resistivity films were prepared at a N2O/Ar gas flow ratio of 0.33. The most intense UV and week blue luminescence was observed for the as‐deposited films. A strong blue luminescence emission due to oxygen vacancies was obtained from the films annealed at 1000 °C. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Approximate Reliability and Availability Models for High Availability and Fault‐tolerant Systems with Repair
Authors: Bowles John B. , Dobbins J. Gregory
Published: September 2004

Systems designed for high availability and fault tolerance are often configured as a series combination of redundant subsystems. When a unit of a subsystem fails, the system remains operational while the failed unit is repaired; however, if too many units in a subsystem fail concurrently, the system fails. Under conditions usually met in practical situations, we show that the reliability and availability of such systems can be accurately modeled by representing each redundant subsystem with a constant, ‘effective’ failure rate equal to the inverse of the subsystem mean‐time‐to‐failure (MTTF). The approximation model is surprisingly accurate, with an error on the order of the square of the ratio mean‐time‐to‐repair to mean‐time‐to‐failure (MTTR/MTTF), and it has wide applicability for commercial, high‐availability and fault‐tolerant computer systems. The effective subsystem failure rates can be used to: (1) evaluate the system and subsystem reliability and availability; (2) estimate the system MTTF; and (3) provide a basis for the iterative analysis of large complex systems. Some observations from renewal theory suggest that the approximate models can be used even when the unit failure rates are not constant and when the redundant units are not homogeneous. Copyright © 2004 John Wiley & Sons, Ltd.
Confined systems and the modified virial theorem from semiclassical considerations
Authors: Mukhopadhyay S. , Bhattacharyya K.
Published: September 2004

We show that two simple semiclassical strategies, one based on the Wilson–Sommerfeld rule and the other on the uncertainty principle, yield the exact modified form of the virial theorem for confined systems. An alternative, easier quantum mechanical route to arrive at this result is also sketched. Pilot calculations on confined oscillators reveal decisive trends. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Method development for the quantitation of ABT‐578 in rabbit artery tissue by 96‐well liquid‐liquid extraction and liquid chromatography/tandem mass spectrometric detection
Authors: Ji Qin C. , Zhang Jun , Rodila Ramona , Watson Pamela , El‐Shourbagy Tawakol
Published: September 2004

Quantitative determination of drug concentrations in tissue samples can provide critical information for drug metabolism, kinetics, and toxicity evaluations. For analysis of tissue samples using liquid chromatography/tandem mass spectrometric (LC/MS/MS) detection, homogenization is a critical step in achieving good assay performance. Assay performance can be closely evaluated by spiking the drug directly into tissue samples prior to homogenization. It is especially important to include this assay evaluation for the analysis of artery tissue samples because artery tissue is very elastic, making it quite a challenge to develop an effective procedure for homogenization. An LC/MS/MS assay in 96‐well format using liquid‐liquid extraction was developed for analyzing ABT‐578 in rabbit artery samples. Tissue quality control samples were prepared by spiking ABT‐578 stock solutions directly into the tissue before homogenization. The usage of the tissue control samples gives a thorough evaluation of the sample preparation process that includes both homogenization and sample extraction. A 20% blood in saline solution was used as a homogenization solution. Calibration standards were made by spiking ABT‐578 into rabbit whole blood. Blood quality control samples were also prepared by spiking ABT‐578 into rabbit whole blood. These blood QC samples were used to confirm the validity of the calibration curve. A lower limit of quantitation of 0.050 ng/mL was achieved. The linear dynamic range of blood standards was from 0.050–30.3 ng/mL with the correlation coefficient (r) ranging from 0.9969–0.9996. Overall %CV was between 1.3 and 7.0%, and analytical recovery was between 98.2 and 105.8% for blood QC samples. The %CVs for tissue QC samples were between 6.7 and 13.0%, and analytical recovery after correction was between 93.5 and 114.3%. Copyright © 2004 John Wiley & Sons, Ltd.
Atmospheric‐pressure Penning ionization mass spectrometry
Authors: Hiraoka Kenzo , Fujimaki Susumu , Kambara Shizuka , Furuya Hiroko , Okazaki Shigemitsu
Published: September 2004

A preliminary study on the atmospheric‐pressure Penning ionization (APPeI) of gaseous organic compounds with Ar* has been made. The metastable argon atoms (Ar*: 11.55 eV for 3P2 and 11.72 eV for 3P0) were generated by the negative‐mode corona discharge of atmospheric‐pressure argon gas. By applying a high positive voltage (+500 to +1000 V) to the stainless steel capillary for the sample introduction (0.1 mm i.d., 0.3 mm o.d.), strong ion signals could be obtained. The ions formed were sampled through an orifice into the vacuum and mass‐analyzed by an orthogonal time‐of‐flight mass spectrometer. The major ions formed by APPeI are found to be molecular‐related ions for alkanes, aromatics, and oxygen‐containing compounds. Because only the molecules with ionization energies less than the internal energy of Ar* are ionized, the present method will be a selective and highly sensitive interface for gas chromatography/mass spectrometry. Copyright © 2004 John Wiley & Sons, Ltd.
Development of a gas chromatography/ion trap mass spectrometry based method for the quantification of polybrominated diphenyl ethers and polychlorinated biphenyls in adipose tissue
Authors: Naert Caroline , Saeger Sarah De , Van Peteghem Carlos
Published: September 2004

A combined gas chromatographic mass spectrometric (GC/MS/MS) method for the determination of seven polybrominated diphenyl ethers (PBDEs) and seven marker polychlorinated biphenyls (PCBs) in adipose tissue has been developed. Adipose tissue was melted and filtered through anhydrous sodium sulphate to obtain pure fat. Clean‐up was performed using a glass column containing acidified silica, deactivated alumina and anhydrous sodium sulphate. Polybrominated biphenyl (PBB) 155 and Mirex were added as internal standards for PBDEs and PCBs, respectively. Injection standards, PBB 103 and PCB 143, for PBDEs and PCBs, respectively, were added before analysis with GC/MS/MS. The developed GC/MS/MS method has the advantage of being more selective than single MS methods because matrix effects are largely eliminated. Validation of this method was conducted according to Commission Decision 2002/657/EC. Decision limits for PBDEs and PCBs ranged from 0.06–0.15 ng g−1 and from 0.35–1.22 ng g−1, respectively. Detection capabilities were all between 0.23–0.55 ng g−1 for PBDEs and between 0.98–2.29 ng g−1 for PCBs. Precision, recovery, bias and selectivity were tested, with satisfactory results. Copyright © 2004 John Wiley & Sons, Ltd.
Formation of a geometric pattern with a mobile wireless sensor network
Authors: Lee Justin , Venkatesh Svetha , Kumar Mohan
Published: September 2004

Mobile wireless sensor networks (MWSNs)will enable information systems to gather detailed information about the environment on an unprecedented scale. These self‐organizing, distributed networks of sensors, processors, and actuators that are capable of movement have a broad range of potential applications, including military reconnaissance, surveillance, planetary exploration, and geophysical mapping. In many of the foreseen applications, the MWSN will need toforma geometric pattern without assistance from the user. In military reconnaissance, for example, the nodes will be dropped onto the battlefield from a plane and land at random positions. The nodes will be expected to arrange themselves into a predetermined formation in order to perform a specific task. Thus, we present algorithms for forming a line, circle, and regular polygon from a given set of random positions. The algorithms are distributed and use no communication between the nodes to minimize energy consumption. Unlike past studies of geometric problems where algorithms are either tested in simulations where each node has global knowledge of all the other nodes or implemented on a small number of robots, the robustness of our algorithms has been studied with simulations that model the sensor system in detail. The simulations demonstrate that the algorithms are robust against random errors in the sensors and actuators. © 2004 Wiley Periodicals, Inc.
Optimal path planning of mobile robots for sample collection
Authors: Cardema J. C. , Wang P. K. C. , Rodriguez G.
Published: September 2004

In this paper, the problem of path planning for sample collection using single or multiple mobile robots such as Mars rovers is formulated as a mathematical optimization problem involving a performance metric based on the scientific values of the collected rock and soil samples. The posed optimization problem is NP‐hard and more complex than the well‐known Traveling Salesman Problem. Algorithms are proposed for obtaining near‐optimal solutions for both single and multiple robots. Their application is illustrated using real Mars surface data. The dependence of the optimal performance on the number of mobile robots is studied numerically. © 2004 Wiley Periodicals, Inc.
Men's studies as a foundation for student development work with college men
Authors: Capraro Rocco L.
Published: September 2004

This chapter surveys the history and theory of men's studies, a field concerned primarily with masculinity and other aspects of men's experience and identity. It argues that men's studies would be an ideal foundation for our work with college men and offers guidelines for programs for men.
Men, spirituality, and the collegiate experience
Authors: Longwood W. Merle , Muesse Mark W. , Schipper William
Published: September 2004

Innovative programs in male spirituality can help college men challenge conventional masculine gender roles and envision creative ways of being men.
Versuche an Verbindungen für Glaskonstruktionen
Authors: Stutzki Christian , Vande Zande Brian J. , Stahl Douglas
Published: September 2004

Dieser Beitrag beschreibt einige Versuchsreihen zur Bestimmung der Tragfähigkeit von Verbindungen im konstruktiven Glasbau. Zwei Typen von Verbindungen werden beschrieben, Reibverbindungen und Lochleibungsverbindungen, und die Ergebnisse der Versuche werden dargestellt und diskutiert. Das Ziel der hier beschriebenen Versuche ist, im Sinne von Pilotversuchen einige Daten für die Bemessung von Verbindungen mit Glasbauteilen zu erhalten, um Berechnungen und Annahmen über diese Verbindungen zu verifizieren. Außerdem bringen diese Versuche eine Reihe wichtiger Erkenntnisse, vor allem über notwendige Qualitätskontrollen bei der Anwendung solcher Anschlüsse in der Praxis.
Experimental evaluation of the tolerance for control‐flow test criteria
Authors: Kapoor Kalpesh , Bowen Jonathan P.
Published: September 2004

Fault‐detection effectiveness of coverage criteria has remained one of the controversial issues in recent years. In order to detect a fault, a test set must execute the faulty statement, cause infection of the data state and then propagate the faulty data state to bring about a failure. This paper sheds some light on the earlier contradictory results by investigating the infection aspect of coverage criteria.

For a given test criterion, the number of test sets satisfying the criterion may be very large, with varying fault‐detection effectiveness. In a recent work the measure of variation in effectiveness of a test criterion was defined as ‘tolerance’. This paper presents an experimental evaluation of tolerance for control‐flow test criteria by exhaustive test set generation, wherever possible. The approach used here is complementary to earlier empirical studies that adopted analysis of some test sets using random selection techniques. Four industrially used control‐flow testing criteria, Condition Coverage (CC), Decision Condition Coverage (DCC), Full Predicate Coverage (FPC) and Modified Condition Decision Coverage (MCDC) have been analysed against four types of faults. A new test criterion, Reinforced Condition Decision Coverage (RCDC), is also analysed and compared. Copyright © 2004 John Wiley & Sons, Ltd.