bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of Optically Active Nanoparticles by Emulsification of Preformed Helical Polymers
Authors: Zhang Yuanyuan , Luo Xiaofeng , Deng Jianping , Yang Wantai 
Published: December 2010

AbstractThe preparation of nanoparticles consisting of chiral helical substituted polyacetylenes via emulsification of the preformed polymers is reported. Two types of helically substituted acetylenes were examined as model polymers: two chiral poly(N‐propargylamide)s and two achiral poly(N‐propargylamide)s. The four polymers were emulsified with SDS as emulsifier to form nanoparticles. The particle size can be modulated by varying the SDS concentration. A comparison between nanoparticle emulsion and the corresponding polymer solution demonstrated obvious blue shifts in the CD spectra of nanoparticle emulsions made from helical polymers with relatively not‐so‐bulky pendent groups, for which the possible mechanism was proposed. magnified image
Imaging lung microstructure in mice with hyperpolarized 3He diffusion MRI
Authors: Wang Wei , Nguyen Nguyet M. , Yablonskiy Dmitriy A. , Sukstanskii Alexander L. , Osmanagic Emir , Atkinson Jeffrey J. , Conradi Mark S. , Woods Jason C. 
Published: December 2010

AbstractQuantitative measurement of lung microstructure is of great significance in assessment of pulmonary disease, particularly in the earliest stages. The technique for MRI‐based 3He lung morphometry was previously developed and validated for human lungs, and was recently extended to ex vivo mouse lungs. The technique yields accurate, quantitative information about the microstructure and geometry of acinar airways. In this study, the 3He lung morphometry technique is successfully implemented for in vivo studies of mice. Results indicate excellent agreement between in vivo morphometry via 3He MRI and microscopic morphometry after sacrifice. This opens up new avenues for application of the technique as a precise, noninvasive, in vivo biomarker of changes in lung microstructure, within various mouse models of lung disease. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Novel 16‐channel receive coil array for accelerated upper airway MRI at 3 Tesla
Authors: Kim Yoon‐Chul , Hayes Cecil E. , Narayanan Shrikanth S. , Nayak Krishna S. 
Published: December 2010

AbstractUpper airway MRI can provide a noninvasive assessment of speech and swallowing disorders and sleep apnea. Recent work has demonstrated the value of high‐resolution three‐dimensional imaging and dynamic two‐dimensional imaging and the importance of further improvements in spatio‐temporal resolution. The purpose of the study was to describe a novel 16‐channel 3 Tesla receive coil that is highly sensitive to the human upper airway and investigate the performance of accelerated upper airway MRI with the coil. In three‐dimensional imaging of the upper airway during static posture, 6‐fold acceleration is demonstrated using parallel imaging, potentially leading to capturing a whole three‐dimensional vocal tract with 1.25 mm isotropic resolution within 9 sec of sustained sound production. Midsagittal spiral parallel imaging of vocal tract dynamics during natural speech production is demonstrated with 2 × 2 mm2 in‐plane spatial and 84 ms temporal resolution. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Iron quantification of microbleeds in postmortem brain
Authors: McAuley Grant , Schrag Matthew , Barnes Samuel , Obenaus Andre , Dickson April , Holshouser Barbara , Kirsch Wolff 
Published: December 2010

AbstractBrain microbleeds (BMB) are associated with chronic and acute cerebrovascular disease and present a source of pathologic iron to the brain proportional to extravasated blood. Therefore, BMB iron content is potentially a valuable biomarker. We tested noninvasive phase image methods to quantify iron content and estimate true source diameter (i.e., unobscured by the blooming effect) of BMB in postmortem human tissue. Tissue slices containing BMB were imaged using a susceptibility weighted imaging protocol at 11.7T. BMB lesions were assayed for iron content using atomic absorption spectrometry. Measurements of geometric features in phase images were related to lesion iron content and source diameter using a mathematical model. BMB diameter was estimated by image feature geometry alone without explicit relation to the magnetic susceptibility. A strong linear relationship (R2 = 0.984, P < 0.001) predicted by theory was observed in the experimental data, presenting a tentative standardization curve where BMB iron content in similar tissues could be calculated. In addition, we report BMB iron mass measurements, as well as upper bound diameter and lower bound iron concentration estimates. Our methods potentially allows the calculation of brain iron load indices based on BMB iron content and classification of BMB by size unobscured by the blooming effect. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Enhancing toughness of low‐density polyethylene filaments through infusion of multiwalled carbon nanotubes and ultrahigh molecular weight polyethylene
Authors: Khan Mujibur R. , Mahfuz Hassan , Leventouri Theodora , Rangari Vijaya K. , Kyriacou Andreas 
Published: December 2010

AbstractWe report enhancement in fracture strain and toughness of low‐density polyethylene by infusing multiwalled carbon nanotubes (MWCNT) and a second‐phase polymer; ultrahigh molecular weight polyethylene (UHMWPE). Infusion of MWCNT improved strength and modulus by about 23 and 57%, respectively, but reduced fracture strain (∼45%) and toughness (∼36%). UHMWPE was then dispersed as a minor phase, and the resulting nanocomposites showed a 55% increase in toughness without any loss of strength or modulus. The loading of MWCNT and UHMWPE was 2 and 8% by weight, respectively. Nanocomposites were in the form of filaments and were extruded through a melt extrusion process. Differential scanning calorimetry and X‐ray diffraction studies revealed increase in crystallinity and crystallite size. Scanning electron microscope micrographs showed sliding of polymer interfaces and changes in fracture process. Strain hardening experiments also showed improvement in strength and modulus but reduction in toughness. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
Synthesis of amphiphilic polyacetal by polycondensation of aldehyde and polyethylene glycol as an acid‐labile polymer for controlled release of aldehyde
Authors: Wang Yanmei , Morinaga Hisatoyo , Sudo Atsushi , Endo Takeshi 
Published: December 2010

AbstractA new acid‐labile polymer having acetal moieties in the main chain was synthesized by polycondensation of poly (ethylene glycol) (PEG) and lilial, an aldehyde widely used in fragrance applications. The hydrophobicity of the resulting acetal moiety and the hydrophilicity of the PEG chain allowed the polyacetal to exhibit amphiphilicity. The polyacetal derived from PEG having weight average molecular weight (Mw) of 1000 (PEG1000) was soluble in water and self‐associated to form associates in water. The polyacetals were hydrolyzed in acidic aqueous solutions to release hydrophobic lilial from the systems. The release rate of aldehyde from the polyacetal derived from PEG1000 was higher than that from the polyacetal derived from PEG having Mw of 400 (PEG400). These results supported that the release rate of lilial can be controlled by the chain length of PEG, on which hydrophilicity of polyacetal depends. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Poly(ε‐caprolactone)‐based shape memory polymers with variable polydimethylsiloxane soft segment lengths
Authors: Zhang Dawei , Giese Melissa L. , Prukop Stacy L. , Grunlan Melissa A. 
Published: December 2010

AbstractThermoresponsive shape memory polymers (SMPs) are stimuli‐responsive materials that return to their permanent shape from a temporary shape in response to heating. The design of new SMPs which obtain a broader range of properties including mechanical behavior is critical to realize their potential in biomedical as well as industrial and aerospace applications. To tailor the properties of SMPs, “AB networks” comprised of two distinct polymer components have been investigated but are overwhelmingly limited to those in which both components are organic. In this work, we prepared inorganic‐organic SMPs comprised of inorganic polydimethylsiloxane (PDMS) segments of varying lengths and organic poly(ε‐caprolactone) (PCL) segments. PDMS has a particularly low Tg (−125 °C) which makes it a particularly effective soft segment to tailor the mechanical properties of PCL‐based SMPs. The SMPs were prepared via the rapid photocure of solutions of diacrylated PCL40‐block‐PDMSm‐block‐PCL40 macromers (m = 20, 37, 66, and 130). The resulting inorganic‐organic SMP networks exhibited excellent shape fixity and recovery. By changing the PDMS segment length, the thermal, mechanical, and surface properties were systematically altered. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Influence of Argon and Nitrogen Admixture in HMDSO/O2 Plasmas onto Powder Formation
Authors: Ricci Marina , Dorier Jean‐Luc , Hollenstein Christoph , Fayet Pierre 
Published: December 2010

AbstractIn situ Fourier transform infrared spectroscopy was used to study the powder formation of hexamethyldisiloxane/O2 plasmas. The spectra show that oxygen plays an important role at the beginning of the process. A large amount of oxygen is responsible for intense powder formation. The admixture of inert or non‐reactant gases, such as Ar or N2, into the plasma promotes polymerization of the monomer. The formation of the particulates, the evolution of their size, and chemical characteristics give evidence of a multistep growth process. The size, as well as the production rate, undergoes a reduction once the Ar or N2 amount is increased in the plasma admixture. magnified image
Atmospheric Pressure Plasma Technology: a Straightforward Deposition of Antibacterial Coatings
Authors: Sarghini S. , Paulussen S. , Terryn H. 
Published: December 2010

AbstractBacterial adhesion and proliferation is a widespread problem following an increasing trend. In this paper, antibacterial coatings were deposited on stainless steel substrates by means of atmospheric pressure plasma technology. Butylamine and 3‐(trimethoxysilyl)‐propyldimethyoctadecylammonium chloride (ODAMO) were used as precursors. The influence of the plasma parameters was investigated by variation of the power input levels and operation under different carrier gases. Characterization of the coating was carried out using contact angle measurement, atomic force microscopy (AFM), field emission scanning electron microscopy (FE‐SEM), and X‐ray photoelectron spectroscopy (XPS). Carrier gas change affected the chemical composition and the surface energy of ODAMO based coating. Moreover, bactericidal activity is decreasing with increase of the plasma power input. Hydrophilic and smooth ODAMO based plasma coating presented the best antibacterial performance. Deposited layers demonstrated up to a log 6 reduction against E. coli after 24 h incubation. Butylamine‐based plasma coatings presented a limited antibacterial effect and the influence of the plasma parameters was not detected. magnified image
Complex networks as a unified framework for descriptive analysis and predictive modeling in climate science
Authors: Steinhaeuser Karsten , Chawla Nitesh V. , Ganguly Auroop R. 
Published: December 2010

AbstractThe analysis of climate data has relied heavily on hypothesis‐driven statistical methods, while projections of future climate are based primarily on physics‐based computational models. However, in recent years a wealth of new datasets has become available. Therefore, we take a more data‐centric approach and propose a unified framework for studying climate, with an aim toward characterizing observed phenomena as well as discovering new knowledge in climate science. Specifically, we posit that complex networks are well suited for both descriptive analysis and predictive modeling tasks. We show that the structural properties of ‘climate networks’ have useful interpretation within the domain. Further, we extract clusters from these networks and demonstrate their predictive power as climate indices. Our experimental results establish that the network clusters are statistically significantly better predictors than clusters derived using a more traditional clustering approach. Using complex networks as data representation thus enables the unique opportunity for descriptive and predictive modeling to inform each other. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 497–511, 2011
Characterization of the TRIP/TWIP effect in austenitic stainless steels using Stress‐Temperature‐Transformation (STT) and Deformation‐Temperature‐Transformation (DTT) Diagrams
Authors: Kovalev A. , Jahn A. , Weiß A. , Scheller P. R. 
Published: December 2010

AbstractStress‐Temperature‐Transformation (STT) and Deformation‐Temperature‐Transformation (DTT) diagrams are suitable to characterize the TRIP (transformation‐induced plasticity) and TWIP (twinning‐induced plasticity) effect in steels. The triggering stresses for the deformation‐induced microstructure transformation processes, the characteristic temperatures, the yield stress and the strength of the steel are plotted in the STT diagram as functions of temperature. The elongation values of the austenite, the strain‐induced twins and martensite formations are shown on the DTT diagram.The systematics of STT and DTT diagrams and the method for their development are described. Especially, the correlations between the STT and DTT diagrams and the thermodynamics are explained in the present paper. The developed STT and DTT diagrams for a novel austenitic Cr‐Mn‐Ni (16%Cr, 6% Mn, 6% Ni) as‐cast steel and austenitic steel AISI 304 are presented. The Cr‐Mn‐Ni steel shows a deformation‐induced α′‐martensite and twin formation. In contrast, the AISI 304 shows a deformation‐induced ε‐ and α′‐martensite formation. The differences between both steel grades are based on thermodynamic pre‐conditions.Therefore the thermodynamic stability conditions of the phases and the kinetics of stress and deformation‐induced martensite and the twins formation are reflected in the developed STT and DTT diagrams.
An active role for splicing in 3′‐end formation
Authors: Martinson Harold G. 
Published: December 2010

AbstractWhen intron‐defined splicing was replaced by exon‐defined splicing in the evolution of higher eukaryotes, the splicing apparatus had to rely on the cleavage/polyadenylation (CP) apparatus for help in defining the 3′‐terminal exon. The 3′‐terminal exon‐definition complex that resulted consists of splicing factors on the upstream 3′ splice site (ss) interacting with CP factors on the downstream poly(A) signal. A speculative model for assembly of this processing complex proposes several discrete steps. First, the splicing factor, U2AF65, interacts with the CP factor, CFIm. Then, CFIm is displaced from U2AF65 by the poly(A) polymerase during a remodeling step. Finally, the U2 snRNP interacts with CPSF in a step resembling spliceosomal A‐complex formation. The result is mutual enhancement of both splicing and CP for the exon. In contrast, when the poly(A) signal is preceded by a 5′ rather than a 3′ ss, competition replaces cooperation. Thus, a poly(A) site in an intron must compete with the upstream 5′ ss for pairing with the 3′ ss further upstream, across the presumptive exon. If the poly(A) site wins the competition, a terminal exon is defined. But if the 5′ ss wins (by defining the upstream exon as internal, followed by pairing with a 3′ ss across the downstream intron), then the poly(A) site is suppressed. The U1 snRNP obviously participates in this competition through its role in splice site pairing. However, the U1 snRNP can also bind elsewhere in the transcript, apart from splice sites, to regulate CP by direct interaction with the CP factors. WIREs RNA 2011 2 459–470 DOI: 10.1002/wrna.68This article is categorized under:

RNA Processing > 3' End Processing
Analysis of a pre‐stressed bi‐material accelerated‐life‐test (ALT) specimen
Authors: Suhir E. 
Published: December 2010

AbstractApplication of mechanical pre‐stressing could be an effective means for achieving a failure‐mode‐shift‐free “destructive ALT effect” in electronic and photonic devices and micro‐electro‐mechanical systems (MEMS). A simple, physically meaningful and easy‐to‐use analytical (“mathematical”) predictive model has been developed to assess the magnitude and the distribution of stresses in a bi‐material assembly subjected to the combined action of thermally induced (considered by the ALT design) and external (“mechanical”) pre‐stressing. Such a compressive pre‐stressing is applied to the assembly component that is expected to experience thermal compression. The model is an extension and a modification of the author's 1986 and 1989 “bi‐metal thermostat” models suggested as a generalization of the 1925 Timoshenko's theory.
Formalizing a hierarchical file system
Authors: Hesselink Wim H. , Lali Muhammad Ikram 
Published: December 2010

Abstract
An abstract file system is defined here as a partial function from (absolute) paths to data. Such a file system determines the set of valid paths. It allows the file system to be read and written at a valid path, and it allows the system to be modified by the Unix operations for creation, removal, and moving of files and directories. We present abstract definitions (axioms) for these operations. This specification is refined towards a pointer implementation. The challenge is to have a natural abstraction function from the implementation to the specification, to define operations on the concrete store that behave exactly in the same way as the corresponding functions on the abstract store, and to prove these facts. To mitigate the problems attached to partial functions, we do this in two steps: first a refinement towards a pointer implementation with total functions, followed by one that allows partial functions. These two refinements are proved correct by means of a number of invariants. Indeed, the insights gained consist, on the one hand, of the invariants of the pointer implementation that are needed for the refinement functions, and on the other hand of the precise enabling conditions of the operations on the different levels of abstraction. Each of the three specification levels is enriched with a permission system for reading, writing, or executing, and the refinement relations between these permission systems are explored. Files and directories are distinguished from the outset, but this rarely affects our part of the specifications. All results have been verified with the proof assistant PVS, in particular, that the invariants are preserved by the operations, and that, where the invariants hold, the operations commute with the refinement functions.
Cancer‐related fatigue: the impact of skeletal muscle mass and strength in patients with advanced cancer
Authors: Kilgour Robert D. , Vigano Antonio , Trutschnigg Barbara , Hornby Laura , Lucar Enriqueta , Bacon Simon L. , Morais José A. 
Published: December 2010

BackgroundAlthough exertional fatigue is directly and negatively related to skeletal muscle mass and strength, it is currently unknown if these variables are associated with cancer‐related fatigue (CRF). Therefore, the purpose of this study was to determine if CRF is associated with measures of appendicular lean muscle mass and strength in advanced cancer patients (ACP).Methods and resultsEighty‐four patients (48 men, 36 women aged 61.6 ± 13.2 year) newly diagnosed (≤6 months) with inoperable (Stages III–IV) gastrointestinal or non‐small cell lung cancer participated in this study. All patients completed the Brief Fatigue Inventory (BFI). Handgrip (HGS) and quadriceps (QS) strength were assessed using isometric and isokinetic dynamometry, respectively. Skeletal muscle mass index (SMMI) was calculated from the appendicular lean mass measured via dual‐energy X‐ray absorptiometry divided by body height squared. Univariate analysis showed BFI to be significantly associated with body mass index, weight loss, anemia, hypoalbuminemia, activity level, pain, depression, and sarcopenia along with SMMI, HGS, and QS. HGS (r = −0.34; p = 0.018), QS (r = −0.39; p = 0.024), and SMMI (r = −0.60; p < 0.001) were negatively correlated with BFI total scores in men but not in women. When adjusted for sex, age, diagnosis, survival, along with the above characteristics, multivariate analyses showed that BFI scores were negatively associated with HGS (B = −0.90; 95% CI −1.5:−0.3), QS (−0.2; −0.3:−0.01), and SMMI (−7.5; −13.0:−2.0). There was a significant sex × SMMI interaction (10.8; 1.2:20.5), where BFI decreased with increasing SMMI in men, but did not change with SMMI in women.ConclusionThese results suggest that in ACP, CRF is related to muscle mass and strength, which may provide targets for future interventions.
Agreement between parent‐ and self‐reports of Algerian adolescents’ behavioral and emotional problems
Authors: Petot Djaouida , Rescorla Leslie , Petot Jean‐Michel 
Published: December 2010

ABSTRACTThe present study examined agreement between scores obtained from self‐reports of behavioral and emotional problems obtained from 513 Algerian adolescents on the Youth Self‐Report (YSR) with scores obtained from reports provided by their parents on the Child Behavior Checklist (CBCL). The correlations between self‐ and parent‐report were larger than those observed in many other cultures (e.g., intraclass correlation coefficient = 0.60 and Pearson r = 0.65 for Total Problems). On the whole, cross‐informant agreement did not vary significantly as a function of problem type, identity of the parental informant, gender and age of the adolescent. Similar to all studied cultures, adolescents on average reported more problems than their parents reported about them, but the discrepancies were smaller than in all previous societies. Mean YSR/CBCL score discrepancies indicated higher YSR scores for several scales, but variability across dyads was large, and many dyads showed the opposite pattern.
Risk factors of sciatic pain: A prospective study among middle—aged employees
Authors: Kääriäl Sanna , Leino‐Arjasl Päivi , Rahkonenl Ossi , Lahtil Jouni , Lahelmal Eero , Laaksonenl Mikko 
Published: December 2010

AbstractObjective: To study the effects of occupational class, physical and psychosocial working conditions, health behaviours, and pain in the low back and the neck on sciatic pain among middle‐aged employees.Methods: The participants were municipal employees without previous sciatica, aged 40, 45, 50, 55, and 60 years at baseline (n =5261, 80% women). Sciatica was defined as low back pain radiating to the calf or the foot. Data on occupational class, physical and psychosocial working conditions, body mass index, smoking, leisure‐time physical activity, neck pain, local low back pain, and sciatica were obtained from baseline questionnaire surveys in 2000–2002. The question on sciatica was repeated in a follow‐up survey in 2007. Logistic regression analysis was used.Results: In women, manual occupational class (OR 1.3; 95% CI 1.0–1.6 compared with managers/professionals), overweight (1.3; 1.1–1.5), obesity (1.4; 1.1–1.7), smoking (1.5; 1.2–1.7), low leisure‐time physical activity (1.3; 1.0–1.7), previous acute (1.5; 1.3–1.7) and chronic (1.5; 1.1–2.0) local low back pain, and acute (1.20; 1.0–1.4) and chronic (1.5;1.2–1.9) neck pain predicted the onset of sciatica in a multivariable model. In men, semi‐professionals (1.5; 1.1–2.1) and manual workers (2.0; 1.4–2.8) had an increased risk compared with managers/professionals; also acute (1.5; 1.2–2.0) and chronic (2.1; 1.2–3.9) local low back pain predicted sciatica.Conclusions: Manual occupational class in both genders and semi‐professional occupations in men, unhealthy behaviours and previous pain both in the neck and the lower back predicted sciatica, while physical and psychosocial working conditions had no independent effect.