bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion of arterial input functions for dual pharmacokinetic modeling using Gd‐DTPA/MRI and 18F‐FDG/PET
Authors: Poulin Eric , Lebel Réjean , Croteau Etienne , Blanchette Marie , Tremblay Luc , Lecomte Roger , Bentourkia M'hamed , Lepage Martin 
Published: May 2012

AbstractReaching the full potential of magnetic resonance imaging (MRI)‐positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium‐diethylenetriaminepentaacetic acid (Gd‐DTPA) in MRI, into a 18F‐fluorodeoxyglucose (18F‐FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98‐Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (Ktrans), the extravascular–extracellular volume fraction (νe), and the blood volume fraction (νp) calculated with the Gd‐DTPA AIF and the Gd‐DTPA AIF converted from 18F‐FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with 18F‐FDG AIF and with 18F‐FDG AIF obtained from Gd‐DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI‐PET pharmacokinetic modeling in small animal models. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Stimulus duration and pain in nerve conduction studies
Authors: Tamura Akiko , Sonoo Masahiro , Hoshino Satoshi , Iwanami Tomoko , Shimada Hiroyuki , Miki Takami , Shimizu Teruo 
Published: May 2012

AbstractIntroduction: It is generally believed that a shorter stimulus duration is less painful in nerve conduction studies (NCS). We investigated whether a shorter duration stimulus is actually less painful when the same physiological effect, such as supramaximal stimulation, is achieved in motor NCS. Methods: The tibial nerve was stimulated at the ankle in 14 control subjects and the median nerve at the wrist in 20 subjects. Two stimulations of different durations were given blindly, and each subject was asked to report which was more painful. Results: A 0.2‐ms‐duration stimulus was significantly less painful than those with longer or shorter durations for the tibial nerve. For the median nerve, the 0.05‐ and 0.2‐ms durations were equally less painful than a 1‐ms‐duration stimulus. Conclusions: As a common duration for motor NCS, 0.2 ms seems appropriate, because the tibial nerve stimulation was more painful than the median nerve stimulation. Muscle Nerve, 2013
Limb‐girdle myasthenia with tubular aggregates associated with novel GFPT1 mutations
Authors: Huh So‐Young , Kim Hyang‐Sook , Jang Ho‐Jung , Park Yeong‐Eun , Kim Dae‐Seong 
Published: May 2012

AbstractIntroduction:Limb‐girdle myasthenia with tubular aggregates (LGM with TAs) is a subtype of congenital myasthenic syndrome caused by recessive mutations of glutamine–fructose‐6‐phosphate transaminase 1 (GFPT1).Methods:Clinical and neurophysiological assessment was made in a Korean boy who had proximal limb muscle weakness. Findings suggested a diagnosis of congenital myasthenic syndrome.Results:Muscle biopsy disclosed numerous TAs in muscle fibers, and DNA sequence analysis disclosed 2 novel missense mutations (p.E256Q and p.M499T) in GFPT1. Treatment with oral cholinesterase inhibitors produced a dramatic improvement in muscle strength.Conclusions:GFPT1 is the key enzyme in the hexosamine biosynthesis pathway, and mutations in GFPT1 cause defective glycosylation in the proteins of the neuromuscular junction. Identification of LGM with TAs among patients with congenital myasthenic syndrome is important because treatment with cholinesterase inhibitors can produce symptomatic improvement. Muscle Nerve 46: 599–602, 2012
Inventory pooling games for expensive, low‐demand spare parts
Authors: Karsten Frank , Slikker Marco , van Houtum Geert‐Jan 
Published: May 2012

AbstractWe consider several independent decision makers who stock expensive, low‐demand spare parts for their high‐tech machines. They can collaborate by full pooling of their inventories via free transshipments. We examine the stability of such pooling arrangements, and we address the issue of fairly distributing the collective holding and downtime costs over the participants, by applying concepts from cooperative game theory. We consider two settings: one where each party maintains a predetermined stocking level and one where base stock levels are optimized. For the setting with fixed stocking levels, we unravel the possibly conflicting effects of implementing a full pooling arrangement and study these effects separately to establish intuitive conditions for existence of a stable cost allocation. For the setting with optimized stocking levels, we provide a simple proportional rule that accomplishes a population monotonic allocation scheme if downtime costs are symmetric among participants. Although our whole analysis is motivated by spare parts applications, all results are also applicable to other pooled resource systems of which the steady‐state behavior is equivalent to that of an Erlang loss system. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
Satisfaction with life for patients undergoing hemodialysis and patients suffering from osteoarthritis
Authors: Laborde Joyce M. , Powers Marjorie J. 
Published: May 2012

AbstractTwo groups of chronically ill patients, alike in some respects of psychological stress and physical limitations but differing in degrees of physical threat to life because of treatment, were compared in terms of quality of life. Twenty patients undergoing hemodialysis at a satellite center and 20 patients with severe osteoarthritis receiving care at a hospital clinic, ranging in age from 40 to 60 years, were randomly selected and asked to rate themselves on Cantril's self‐anchoring scale in relation to past, present, and future life satisfaction. An ANOVA for simple main effects indicated that patients undergoing hemodialysis viewed present life satisfaction significantly higher, F = 4.81, p < .05, than did patients with arthritis. Expectation for greater life satisfaction tended to be slightly better for dialysis patients, but not significantly so; past life satisfaction was the same for both groups. Dialysis patients viewed their present life better than past life, whereas arthritis patients had the opposite viewpoint. The increased life satisfaction among dialysis patients may be the result of an increased sense of physical well‐being because of the dialysis procedure, and chronic pain may be a factor in the decreased life satisfaction among arthritis patients.
A critique of several conceptions of practice theory in nursing
Authors: Beckstrand Jan 
Published: May 2012

AbstractThe thesis of this article is that the Dickoff, James, and Wiedenbach (1968a, 1968b) conception of a practice theory is roughly equivalent to a plan of action. This idea is contrasted with other conceptions of a prescriptive practice theory, especially the set‐of‐rules conception described by Jacox (1974). The set‐of‐rules conception is shown to be untenable, and other conceptions of practice theory are shown to be nothing more than examples of established forms of knowledge.
The stress process in family caregivers of persons receiving chemotherapy
Authors: Schumacher Karen L. , Dodd Marylin J. , Paul Steven M. 
Published: May 2012

AbstractThe purpose of this analysis was to explore strain and depression among family caregivers of persons receiving chemotherapy for cancer using the Pearlin Stress Process Model. Seventy‐five family caregivers of persons receiving chemotherapy participated, completing the Caregiver Strain Index and the Depression Subscale of the Profile of Mood States within 3 weeks of the initiation of chemotherapy. Hierarchical regression analyses indicated that 44% of the variance in strain and 40% of the variance in depression were explained by the antecedent variables of caregiver age and gender, patient age and gender, patient functional status, the presence of recurrent disease, perceived efficacy of coping strategies, and perceived adequacy of social support. Further analysis aimed at delineating the mechanisms through which coping and social support operate in the model found no evidence for a moderating or stress‐buffering effect. However, coping mediated the relationship between strain and depression and social support mediated the relationship between functional status and depression.
Assessing Executive and Community Functioning Among Homeless Persons with Substance Use Disorders Using the Executive Function Performance Test
Authors: Raphael‐Greenfield Emily 
Published: May 2012

AbstractThis study investigates the utility of an occupational therapy assessment of executive and performance functioning and indicators of community adjustment among adults with histories of homelessness and substance abuse.A sample of 60 individuals living in a supported housing programme was interviewed about community living experiences and was assessed using the Executive Function Performance Test (EFPT). A descriptive and correlational study design was used.Measurable levels of cognitive and task impairment were documented, in older adults, non‐US citizens and those diagnosed with cognitive impairments. Those who had completed a supported education/employment programme (Total EFPT t = −2.83, 0.008) performed better as did those who were employed (Total EFPT t = −2.33, 0.03), met regularly with their case managers (cooking t = −2.07, 0.04), had hobbies (paying bills r = −0.31, 0.02) and had longer periods of abstinence (organization/planning t = −3.59, 0.001).Limitations of the study include the unanticipated need by the clients for additional translation services. Future directions include a randomized controlled intervention study using the EFPT. An implication of this study for occupational therapists working with homeless clients who abuse substances is the importance of assessing and treating their cognitive impairments as well as providing these services within housing first agencies. Copyright © 2012 John Wiley & Sons, Ltd.
Combination of nitroxide‐mediated polymerization and SET‐LRP for the synthesis of high molar mass branched and star‐branched poly(n‐butyl acrylate) characterized by size exclusion chromatography and rheology
Authors: Paillet Sabrina , Roncin Armelle , Clisson Gérald , Pembouong Gaëlle , Billon Laurent , Derail Christophe , Save Maud 
Published: May 2012

AbstractBranched and star‐branched polymers were successfully synthesized by the combination of two successive controlled radical polymerization methods. A series of linear and star poly(n‐butyl acrylate)‐co‐poly(2‐(2‐bromoisobutyryloxy) ethyl acrylate) statistical copolymers, P(nBA‐co‐BIEA)x, were first synthesized by nitroxide‐mediated polymerization (NMP at T > 100 °C). The subsequent polymerization of n‐butyl acrylate by single electron transfer‐living radical polymerization (SET‐LRP at T = 25 °C), initiated from the brominated sites of the P(nBA‐co‐BIEA)x copolymer, produced branched or star‐branched poly(n‐butyl acrylate) (PnBA). Both types of polymerizations (NMP and SET‐LRP) exhibited features of a controlled polymerization with linear evolutions of logarithmic conversion versus time and number‐average molar masses versus conversion for final Mn superior to 80,000 g mol−1. The branched and star‐branched architectures with high molar mass and low number of branches were fully characterized by size exclusion chromatography. The Mark–Houwink Sakurada relationship and the analysis of the contraction factor (g′ = ([η]branched/[η]linear)M) confirmed the elaboration of complex PnBA. The zero‐shear viscosities of the linear, star‐shaped, branched, and star‐branched polymers were compared. The modeling of the rheological properties confirmed the synthesis of the branched architectures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis and radical polymerization of styrene‐based monomer having a five‐membered cyclic carbonate structure
Authors: Miyata Takahiro , Matsumoto Kozo , Endo Takeshi , Yonemori Shigeaki , Watanabe Shoji 
Published: May 2012

AbstractA styrene‐based monomer having a five‐membered cyclic carbonate structure, 4‐vinylbenzyl 2,5‐dioxoran‐3‐ylmethyl ether (VBCE), was prepared by lithium bromide‐catalyzed addition of carbon dioxide to 4‐vinylbenxyl glycidyl ether (VBGE). Radical polymerization of the obtained VBCE was carried out using 2,2′‐azobisisobutyronitrile as an initiator. PolyVBCE with number‐averaged molecular weight higher than 13,800 was obtained by a solution polymerization in N,N‐dimethylformamide, N,N‐dimethylacetamide, dimethyl sulfoxide, and methyl ethyl ketone. The glass transition temperature and 5 wt % decomposition temperature of the polyVBCE were determined to be 52 and 305 °C by differential scanning calorimetry and thermal gravimetry analysis, respectively. It was confirmed that a polymer consisting of the same VBCE repeating unit can be also obtained via chemical modification of polyVBGE, that is, a lithium‐bromide‐catalyzed addition of carbon dioxide to a polyVBGE prepared from a radical polymerization of VBGE. Further copolymerization of VBCE with styrene gave the corresponding copolymer in a high yield. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Spiky nanostructured metal particles as filler of polymeric composites showing tunable electrical conductivity
Authors: Stassi Stefano , Canavese Giancarlo 
Published: May 2012

AbstractThis work presents a comprehensive investigation of the piezoresistive response of a composite material based on conductive nickel filler in a silicone‐insulating matrix. In the absence of a deformation, the prepared composite shows no electric conductivity, even though the metal particle content is well above the expected percolation threshold. Upon samples deformation (compressive or tensile stress), the composite exploits a variation of electrical resistance up to nine orders of magnitude. This huge variation can be explained with the quantum tunnelling mechanism where the probability of an electron to tunnel from a particle to the next one is exponentially proportional to the thickness of the insulating layer between them and strongly enhanced by the morphology of the nickel particles, showing spiky nanostructured tips. Two different conduction theoretical models are proposed and compared with the experimental results. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Improving the performance of established PSM programs
Authors: Klein James A. , Dharmavaram S. 
Published: May 2012

AbstractMany facilities have now implemented and maintained process safety management (PSM) programs for 20 years or more, but these facilities continue to have sometimes serious incidents and injuries suggesting a continuing need to improve their PSM performance. Of course, new requirements are often added to upgrade PSM programs, due to near‐miss learnings, audit findings, and new recommended and generally accepted good engineering practices, for example, but often overall performance improvements have not occurred or have not achieved the desired level of performance. How can significant performance improvements be obtained? Although performance issues at different facilities will certainly vary, this article provides several key approaches for improving overall PSM performance and for helping prevent injuries and incidents. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
Nernst coefficient and scattering parameter in PbTe films
Authors: Ariga Tomoki , Koyano Mikio , Ishida Akihiro 
Published: May 2012

AbstractFor the study of thermoelectric materials, it is important to determine the carrier‐scattering mechanisms. For this study, we investigated the carrier‐scattering mechanism in doped lead telluride (PbTe) by analyzing the electrical properties and the Nernst coefficient: ANe. The sign of the Nernst coefficient is related not to carrier types but the residual resistivity ratio (RRR). For a high‐RRR sample, the dominant carrier‐scattering mechanism is acoustic phonon scattering. However, the carrier‐scattering mechanism is complicated in low‐RRR samples. The large scattering parameters obtained from ANe indicate that the high‐energy conduction carriers are more difficult to scatter than are low‐energy carriers.
Evaluation of the bond polarizabilities of zincblende‐type semiconductors: Application to the Raman spectra of disordered GaSb/AlSb (001) superlattices
Authors: Berdekas D. , Ves S. 
Published: May 2012

AbstractWe derive expressions for the bond polarizability (BP) parameters involving only directly measurable quantities, such as dielectric and elasto‐optic constants of the bulk crystal and apply them to zincblende‐type crystals. The vibrational modes are calculated on the basis of an eleven (11) parameter rigid‐ion model approximation (RIM). Having estimated the BP parameters for GaSb and AlSb bulk crystals, we calculate the Raman spectra away of resonance conditions for the vibrations of perfect and disordered (GaSb)1/(AlSb)1 (001) superlattices (SL). The disordered SL is approximated with primitive cells much larger than the primitive cell of the perfect 1 × 1 SL. Furthermore, we show that disorder modifies the Raman spectra of the perfect SL by introducing asymmetry as well as by the formation of additional peaks in both the acoustic and optical range of the Raman spectra. Puzzlingly, even a small degree of disorder, results in a blueshift of all modes frequencies, especially the strongest optical ones.
Modeling molecular interactions by analytic potentials: Analytic perturbation treatment
Authors: Kryachko Eugene S. 
Published: May 2012

AbstractOne of the chief concepts of molecular interactions is the concept of the molecular potential. This work focuses on the class of so‐called spiked potentials. It is analytically demonstrated that despite the common belief that the traditional perturbation theory is not applicable to study the class of potentials combining the harmonic oscillator with a singular potential of the type λr−α, this work aims to propose and develop such treatment on the basis of the appropriate choice of the zero‐order exactly solvable Hamiltonian Ho = −(
$\hbar^2$/(2m))∇ + U2 where U2(r) = αr2 + β/r−2. © 2012 Wiley Periodicals, Inc.
Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high‐resolution mass spectrometry
Authors: Amad Salim Sioud, Ma'an , Al‐Talla Zeyad A. 
Published: May 2012

RATIONALETo enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water‐soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored.METHODSA multicomponent mixed dopant for non‐targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high‐resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated.RESULTSFourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2‐ to 10‐fold for the tested PAHs compared to those obtained with pure chlorobenzene.CONCLUSIONSA novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high‐resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/μL levels within a 5 min run time with high mass accuracy ≤4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.
Systematic evaluation of the root cause of non‐linearity in liquid chromatography/tandem mass spectrometry bioanalytical assays and strategy to predict and extend the linear standard curve range
Authors: Yuan Long , Zhang Duxi , Jemal Mohammed , Aubry Anne‐Francoise 
Published: May 2012

RATIONALEThe linear range of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) bioanalytical assay is typically about three orders of magnitude. A broader standard curve range is favored since it can significantly reduce the time, labor and potential errors related to sample dilution – one of the bottlenecks in sample analysis. Using quadratic regression to fit the standard curve can, to a certain degree, extend the dynamic range. However, the use of a quadratic regression is controversial, particularly in regulated bioanalysis.METHODSA number of compounds, with different physicochemical properties and ionization efficiencies, were evaluated to understand the cause of the non‐linear behavior of the standard curve.RESULTSThe standard curve behavior is primarily associated with the absolute analyte response but not the analyte concentration, the properties of the analyte, or the nature of the matrix when a stable‐isotope‐labeled internal standard (SIL‐IS) is used. For all the test compounds, a non‐linear curve was observed when signals exceeded a certain response, which depends on the detector used in the mass spectrometer. With typical API4000 instruments used for the experiments, this critical response level was determined to be ~1 E+6 counts per second (cps) and it was successfully used to predict the linear ranges for the test compounds. By simultaneously monitoring two selective reaction monitoring (SRM) channels of different intensity and using SIL‐IS, a linear range of five orders of magnitude was achieved.CONCLUSIONSIn this work, the root cause of the non‐linear behavior of the standard curve when using a SIL‐IS was investigated and identified. Based on the findings, an improved multiple SRM channels approach was proposed and successfully applied to obtain a linear dynamic range of five orders of magnitude for one test compound. This approach may work particularly well for LC/MS/MS bioanalytical assay of dried blood spot (DBS) samples, for which a direct dilution is cumbersome. Copyright © 2012 John Wiley & Sons, Ltd.
Cooperative control of dynamically decoupled systems via distributed model predictive control
Authors: Müller Matthias A. , Reble Marcus , Allgöwer Frank 
Published: May 2012

SUMMARYIn this paper, we propose a general framework for distributed model predictive control of discrete‐time nonlinear systems with decoupled dynamics but subject to coupled constraints and a common cooperative task. To ensure recursive feasibility and convergence to the desired cooperative goal, the systems optimize a local cost function in a sequential order, whereas only neighbor‐to‐neighbor communication is allowed. In contrast to most of the existing distributed model predictive control schemes in the literature, we do not necessarily consider the stabilization of an a priori known set point. Instead, also other cooperative control tasks such as consensus and synchronization problems can be handled within the proposed framework. In particular, one of our main contributions is to show how for the latter case the terminal cost functions and the terminal region can be suitably defined and computed. Furthermore, we illustrate our results with simulation examples. Copyright © 2012 John Wiley & Sons, Ltd.