bluuebunny/crossref_metadata_2025_split huggingface dataset:
A combined fracture‐micromechanics model for tensile strain‐softening in brittle materials, based on propagation of interacting microcracks
Authors: Pichler Bernhard , Hellmich Christian , A. Mang Herbert 
Published: September 2006

AbstractStrain‐softening is the decline in stress at increasing strain. Although microcracking is a commonly accepted reason for strain‐softening, the majority of theoretical developments involve macroscopic damage evolution laws. To improve this situation, we propose a micromechanics‐based damage evolution law by combining (i) the propagation criterion for a single penny‐shaped crack embedded in an infinite matrix subjected to remote stresses (taken from linear‐elastic fracture mechanics) and (ii) stiffness estimates for representative material volumes comprising interacting microcracks (taken from continuum micromechanics). This combination allows for modelling tensile strain‐softening as a result of propagation of interacting microcracks, i.e. as a microstructural effect. The initial degree of damage, i.e. the initial microcrack size and the number of microcracks per unit volume, implies two different types of model‐predicted tensile strain‐softening behaviour under strain control: (i) continuous strain‐softening, which occurs in case of initial damage above a critical value, and (ii) an instantaneous stress drop at the peak load (‘snap‐back’), which occurs in case of initial damage below a critical value. Copyright © 2006 John Wiley & Sons, Ltd.
The in vitro effects of a bimodal contrast agent on cellular functions and relaxometry
Authors: Brekke Cecilie , Morgan Sarah C. , Lowe Andrew S. , Meade Thomas J. , Price Jack , Williams Steve C. R. , Modo Michel 
Published: September 2006

AbstractThe in vivo monitoring of cell survival and migration will be essential to the translation of cell‐based therapies from the laboratory to clinical studies. The pre‐labeling of cells with magnetic resonance imaging (MRI) contrast agents renders them visible in vivo for serial cellular imaging. However, little is known about the impact of the presence of these metal particles inside transplanted cells. The use of the bimodal contrast agent GRID made it possible to demonstrate by means of fluorescent microscopy and inductively coupled plasma mass spectrometry (ICP‐MS) that, after 16 h of incubation (without the use of a transfection agent), neural stem cells (NSCs) were saturated and no longer incorporated particles. With this maximal uptake, no significant effect on cell viability was observed. However, a significant decrease in proliferation was evident in cells that underwent 24 h of labeling. A significant increase in reactive oxygen species was observed for all GRID labeling, with a very significant increase with 24 h of labeling. GRID labeling did not affect cell motility in comparison with PKH26‐labeled NSCs in a glioma‐based migration assay and also allowed differentiation into all major cell types of the brain. GRID‐labeled cells induced a signal change of 47% on T2 measurements and allows a detection of cell clusters of ∼220 cells/µl. Further in vivo testing will be required to ensure that cell labeling with gadolinium‐based MRI contrast agents does not impair their ability to repair. Copyright © 2006 John Wiley & Sons, Ltd.
Quantitative MRI‐pathology correlations of brain white matter lesions developing in a non‐human primate model of multiple sclerosis
Authors: Blezer Erwin L. A. , Bauer Jan , Brok Herbert P. M. , Nicolay Klaas , 't Hart Bert A. 
Published: September 2006

AbstractExperimental autoimmune encephalomyelitis (EAE) induced with recombinant human myelin/oligodendrocyte glycoprotein in the common marmoset is a useful preclinical model of multiple sclerosis in which white matter lesions can be well visualized with MRI. In this study we characterized lesion progression with quantitative in vivo MRI (4.7 T; T1 relaxation time ± Gd‐DTPA; T2 relaxation time; magnetization transfer ratio, MTR, imaging) and correlated end stage MRI presentation with quantitative ex vivo MRI (formaldehyde fixed brains; T1 and T2 relaxation times; MTR) and histology. The histopathological characterization included axonal density measurements and the numeric quantification of infiltrated macrophages expressing markers for early active [luxol fast blue (LFB) or migration inhibition factor‐related protein‐14 positive] or late active/inactive [periodic acid Schiff (PAS) positive] demyelinating lesion. MRI experiments were done every two weeks until the monkeys were sacrificed with severe EAE‐related motor deficits. Compared with the normal appearing white matter, lesions showed an initial increase in T1 relaxation times, leakage of Gd‐DTPA and decrease in MTR values. The progressive enlargement of lesions was associated with stabilized T1 values, while T2 initially increased and stabilized thereafter and MTR remained decreased. Gd‐DTPA leakage was highly variable throughout the experiment. MRI characteristics of the cortex and (normal appearing) white matter did not change during the experiment. We observed that in vivo MTR values correlated positively with the number of early active (LFB+) and negatively with late active (PAS+) macrophages. Ex vivo MTR and relaxation times correlated positively with the number of PAS‐positive macrophages. None of the investigated MRI parameters correlated with axonal density. Copyright © 2006 John Wiley & Sons, Ltd.
Ethylene–propylene copolymerization with bis(β‐enaminoketonato) titanium complexes activated with modified methylaluminoxane
Authors: Tang Li‐Ming , Li Yan‐Guo , Ye Wei‐Ping , Li Yue‐Sheng 
Published: September 2006

AbstractEthylene–propylene copolymerization, using [(Ph)NC(R2)CHC(R1)O]2TiCl2 (R1 = CF3, Ph, or t‐Bu; R2 = CH3 or CF3) titanium complexes activated with modified methylaluminoxane as a cocatalyst, was investigated. High‐molecular‐weight ethylene–propylene copolymers with relatively narrow molecular weight distributions and a broad range of chemical compositions were obtained. Substituents R1 and R2 influenced the copolymerization behavior, including the copolymerization activity, methylene sequence distribution, molecular weight, and polydispersity. With small steric hindrance at R1 and R2, one complex (R1 = CF3; R2 = CH3) displayed high catalytic activity and produced copolymers with high propylene incorporation but low molecular weight. The microstructures of the copolymers were analyzed with 13C NMR to determine the methylene sequence distribution and number‐average sequence lengths of uninterrupted methylene carbons. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5846–5854, 2006
Conjugated dendrimers with triazine peripheries and a distyrylanthracene core
Authors: Kim Chae Kyu , Song Eun Seok , Kim Hyung Joo , Park Chiyoung , Kim Jai Kyeong , Kim Young Chul , Yu Jae Woong , Kim Chulhee 
Published: September 2006

AbstractWe describe the synthesis and luminescence characterization of conjugated dendrimers with triazine peripheries and a distyrylanthracene core that are suitable for electroluminescence applications. The dendrimers consist of dendritic triazine wedges with high electron affinity, stilbene branches, and a distyrylanthracene core as an emitting moiety. The dendrimers have lowest unoccupied molecular orbital values of about −2.7 eV. Photoluminescence studies have indicated that a cascade energy transfer occurs from the triazine wedges to the stilbene bridges and finally to the distyrylanthracene core. Thus, the emission wavelength is determined by the distyrylanthracene core unit. The energy‐transfer efficiency of the distyrylanthracene‐cored dendrimers is about 47 and 20% for the first and second generations, respectively. A preliminary electroluminescence property investigation has also been conducted. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5855–5862, 2006
Construction of diads and triads copolymer systems containing perylene, porphyrin, and/or fullerene blocks
Authors: Wang Ning , Lu Fushen , Huang Changshui , Li Yuliang , Yuan Mingjian , Liu Xiaofeng , Liu Huibiao , Gan Liangbing , Jiang Li , Zhu Daoben 
Published: September 2006

AbstractA series of conjugated copolymers containing perylene, porphyrin, and/or fullerene units on the main chain have been synthesized. The structures and photophysical properties of polymers were characterized by FTIR, NMR, UV–vis, and fluorescence spectroscopy, gel permeation chromatography, and cyclic voltammetry. The photoinduced charge transfer properties of the films were also measured by a three‐electrode cell technique. A rapid, steady, and reproducible cathodic photocurrent response for each polymer was produced when the film was irradiated by a white light. The SEM and TEM images displayed the aggregation superstructures of the polymers. In chloroform, polySPeZnP2F could form a large quantity of spherical nanoparticles. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5863–5874, 2006
Synthesis of new thermosetting poly(2,6‐dimethyl‐1,4‐phenylene oxide)s containing epoxide pendant groups
Authors: Huang Chih‐Chiao , Yang Ming‐Syun , Liang Mong 
Published: September 2006

AbstractA new class of thermosetting poly(2,6‐dimethyl‐1,4‐phenylene oxide)s containing pendant epoxide groups were synthesized and characterized. These new epoxy polymers were prepared through the bromination of poly(2,6‐dimethyl‐1,4‐phenylene oxide) in halogenated aromatic hydrocarbons followed by a Wittig reaction to yield vinyl‐substituted polymer derivatives. The treatment of the vinyl‐substituted polymers with m‐chloroperbenzoic acid led to the formation of epoxidized poly(2,6‐dimethyl‐1,4‐phenylene oxide) with variable pendant ratios, and the structures and properties were studied with nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The ratios of pendant functional groups were tailored for the polymer properties, and the results showed that the glass‐transition temperatures increased as the benzylic protons were replaced by bromo‐, vinyl‐, or epoxide‐functional groups, whereas the thermal stability decreased in comparison with the original polymer. Within a molar fraction of 20–50%, the degree of functionalization had little effect on the glass‐transition temperature; however, it correlated inversely with the thermal stability of each functionalized polymer. The thermal curing behavior of the epoxide‐functionalized polymer was enhanced by the increment of the pendant functionality, which resulted in a significant increase in the glass‐transition temperature as well as the thermal stability after the curing reaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5875–5886, 2006
Starch‐graft‐copolymer latexes initiated and stabilized by ozonolyzed amylopectin
Authors: De Bruyn Hank , Sprong Ewan , Gaborieau Marianne , David Ghislain , Roper John A. , Gilbert Robert G. 
Published: September 2006

AbstractA method is presented for synthesizing surfactant‐free latexes comprising a starch‐graft‐vinyl polymer, (1) starting with a suspension of the highly branched starch amylopectin, either native or degraded, (2) then using ozonolysis to create free‐radical initiation sites on this amylopectin scaffold, and (3) finally adding the monomer and inducing polymerization. The ozone simultaneously thins the starch and creates initiating/grafting sites on the starch, from which starch‐graft‐copolymer latexes can be grown. The encapsulation of starch inside the hydrophobic polymer particles created by a heterogeneous free‐radical polymerization process is demonstrated with energy‐dispersive spectroscopy; this is the first time that the particle morphology of such a latex has been so characterized. The data unambiguously prove that low‐molar‐mass degraded starch can be encapsulated within a latex particle. The underlying mechanisms have been explored, and data quantifying the rates of production of hydroperoxides by ozone, the thermal decomposition of the starch hydroperoxides so formed, and the degradation of amylopectin by ozone are reported. The activation energy for the thermal decomposition of the starch macroinitiator, determined in this work to be 125 ± 8 kJ mol−1, is consistent with the proposition that the initiating species are mainly hydroperoxides. Colloidally stable poly(styrene‐co‐n‐butyl acrylate) latexes based on high‐molar‐mass amylopectin have been developed. These are stable against electrolytes (several months in 4 mol L−1 NaCl), with 20% of the starch effectively grafted to the particles. Films cast from such latexes are more pliable than starch films and are readily redispersed in water. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5832–5845, 2006
Compactifications of the heterotic string with unitary bundles
Authors: Weigand T. 
Published: September 2006

AbstractWe describe a large new class of four‐dimensional supersymmetric string vacua defined as compactifications of the E8 × E8 and the SO(32) heterotic string on smooth Calabi‐Yau threefolds with unitary gauge bundles and heterotic five‐branes. The conventional gauge symmetry breaking via Wilson lines is replaced by the embedding of non‐flat line bundles into the ten‐dimensional gauge group, thus opening up the way for phenomenologically interesting string compactifications on simply connected manifolds. After a detailed analysis of the four‐dimensional effective theory we exemplify the general framework by means of a couple of explicit examples involving the spectral cover construction of stable holomorphic bundles. As for the SO(32) heterotic string, the resulting vacua can be viewed, in the S‐dual Type I picture, as a generalisation of magnetized D9/D5‐brane models. In the case of the E8 × E8 string, we find a natural way to construct realistic MSSM‐like models, either directly or via a flipped SU(5) GUT scenario.
Relief system's last line of defense, only line of defense?
Authors: Melhem G.A. 
Published: September 2006

AbstractA relief system is often referred to as the “last line of defense.” However, it should not be the “only line of defense.”This article provides an expert perspective and interpretation of today's legal climate with respect to projects involving pressure‐relief systems for reactive chemicals. A case study involving the storage of uninhibited butadiene is used to illustrate key concepts and recommendations. Recognized and generally accepted good engineering practices (RAGAGEP) are cited to illustrate the importance of using layers of protection. In other words, a pressure‐relief system should not be the only layer of protection, especially for reactive chemicals. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006
Managing on stream leak repairs
Authors: Wilson Jesse , Frazier Mark 
Published: September 2006

AbstractThe purpose of a fabricated equipment mechanical integrity program is to ensure the reliable containment of process contents. An on stream leak of a pressure vessel, piping circuit, tank, or other piece of process equipment represents a failure of the mechanical integrity program, which could negatively impact the safety, reliability, and environmental performance of a process unit. This mechanical integrity failure and its potential consequences can be mitigated, however, if an “On Stream Leak Repair” (OSLR) can be accomplished in a safe and reliable manner. This article addresses the typical hazards associated with OSLRs and offers some practical advice as to how to manage their implementation and verify their eventual removal. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006
Comparison of Three Rewarming Methods in a Postanesthesia Care Unit
Authors: Hershey June , Valenciano Cora , Bookbinder Marilyn 
Published: August 2006

ABSTRACTPostoperative hypothermia is problematic because patients in postanesthesia care units (PACUs) often feel very cold, and unrecognized or prolonged postoperative hypothermia can aggravate patients' underlying cardiovascular disorders. The researchers compared three methods of rewarming PACU patients who had undergone laparotomy procedures. Patients were assigned randomly to three groups. Each patient in group one received the standard PACU rewarming intervention (ie, two warmed thermal blankets and a hospital bedspread). Each patient in group two received the standard PACU rewarming intervention plus a reflective blanket. Each patient in group three received the standard PACU rewarming intervention plus a reflective blanket and a reflective head covering. Nurses measured patients' vital signs on admission to the PACU and every 15 minutes thereafter until patients' sublingual temperatures reached 36°C (96.8°F). No significant temperature differences occurred among patients in the three groups, but an inverse relationship existed between patients' PACU admission temperatures and the time they required to reach normothermia. AORN J 65 (March 1997) 597–601.
Project Alpha Provides Opportunities to Promote Perioperative Nursing
Authors: Graybill‐D'Ercole Patricia A. 
Published: August 2006

ABSTRACTThis article provides an overview of AORN's Project Alpha and identifies multiple opportunities for RNs to promote the nursing profession and the perioperative nursing specialty. Individual and group Project Alpha activities can be used to enhance the education of health care consumers and other professionals about the essential role of perioperative nurses in the care of patients undergoing operative and other invasive procedures. The author suggests innovative strategies for AORN members to use in planning Project Alpha activities. AORN J 64 (Nov 1996) 781–785.
DURABLE EMPIRE: STATE VIRTUOSITY AND SOCIAL ACCOMMODATION IN THE OTTOMAN MEDITERRANEAN
Authors: DOUMANIS NICHOLAS 
Published: September 2006

Subjects of the sultan: culture and daily life in the Ottoman empire. By Suraiya Faroqhi. London: I. B. Tauris, 2000. Pp. x+358. ISBN 1-86064-289-6. £35.00.The Ottoman empire and early modern Europe. By Daniel Goffman. Cambridge: Cambridge University Press, 2002. Pp. xvi+273. ISBN 0-5214-59087. £15.99.A shared world: Christians and Muslims in the early modern Mediterranean. By Molly Greene. Princeton, NJ: Princeton University Press, 2000. Pp. xiv+228. ISBN 0-619-00898-1. $29.50.Christians and Jews in the Ottoman Arab world: the roots of sectarianism. By Bruce Masters. Cambridge: Cambridge University Press, 2001. Pp. xiv+222. ISBN 0-521-803330. £48.00.Consumption studies and the history of the Ottoman empire, 1560–1922: an introduction. Edited by Donald Quataert. Albany, NY: State University of New York Press, 2000. Pp. vii+358. ISBN 0-7914-4431-7. $25.50.The Ottoman empire, 1700–1922. Second edition. By Donald Quataert. Cambridge: Cambridge University Press, 2005. Pp. xxii+212. ISBN 0-521-839106. £40.00.Since Edward Said first launched his devastating critique of western scholarship on the Islamic world, it has been almost impossible to think of Orientalism as anything other than a euphemism for the systematic distortion of an exotic Other. That imaginings of a fanciful ‘Orient’ are now recognized as providing acute expositions of western pathologies, of references to deep-seated desires and anxieties so disturbing that they only reveal themselves in alterities, goes some way towards explaining the sheer bulk of interdisciplinary publications that have been directly inspired by Said's Orientalism.1 As reflexive phenomena, however, such publications have even less to say about the real ‘Orient’. Rather, the historical reconstruction of Orientalism's ostensible subject has been left to a separate and less conspicuous stream of scholarship that is characterized by painstaking archival research.
Magnetic resonance signal, rather than tendon volume, correlates to pain and functional impairment in chronic achilles tendinopathy
Authors: Gärdin A. , Bruno J. , Movin T. , Kristoffersen-Wiberg M. , Shalabi A. 
Published: September 2006

Purpose: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment. Material and Methods: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37–71 years). All patients suffered from pain in the mid-portion of the Achilles tendon. Intratendinous signal was calculated from five different sagittal sequences, using a computerized 3D seed-growing technique. Pain and functional impairment were evaluated using a questionnaire completed by patients. Results: Severity of pain and functional impairment correlated to increased mean intratendinous signal in the painful tendon in all MR sequences ( P<0.05, median r = 0.38, range 0.28–0.43 for pain; P<0.05, median r = 0.48, range 0.29–0.49 for functional impairment). However, tendon volume did not correlate to pain or functional impairment ( P>0.05). Difference in mean intratendinous signal between symptomatic and contralateral asymptomatic tendons was highly significant in all sequences ( P<0.05) except on T2-weighted images ( P = 0.6). Conclusion: Severity of pain and disability correlated to increased MR signal rather than to tendon volume in patients with unilateral mid-portion chronic Achilles tendinopathy.
Effects of three different swallow maneuvers analyzed by videomanometry
Authors: Bodén K. , Hallgren Å. , Witt Hedström H. 
Published: September 2006

Purpose: To evaluate the manometric effects of three different swallow maneuvers on healthy volunteers. Material and Methods: Ten healthy volunteers with no history of swallowing complaints were evaluated with simultaneous videoradiography and pharyngeal manometry (videomanometry). Three different swallow maneuvers were evaluated (supraglottic swallow, super-supraglottic swallow, and Mendelsohn's maneuver) and seven manometric and two videoradiographic variables were analyzed. Results: The supraglottic swallow showed a significantly weaker peak contraction of the upper esophageal sphincter (UES). The super-supraglottic swallow had a significantly higher UES relaxation pressure and the Mendelsohn maneuver a significantly higher UES peak contraction. With the Mendelsohn maneuver, there was also a significantly longer duration of the pharyngeal contraction and a significantly weaker UES peak contraction. Both the super-supraglottic and the Mendelsohn maneuver had a significantly longer bolus transit time. Conclusion: Our study did not show any significant difference in the relaxation duration of any of the swallowing maneuvers compared to a control swallow. With the Mendelsohn maneuver, we found that both the pharyngeal peak contraction and contraction duration were increased, which might result in an improved propulsion of bolus into the esophagus.