bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyester nanocomposite fibers with improved flame retardancy and thermal stability
Authors: Teli Mangesh D. , Kale Ravindra D. 
Published: March 2012

AbstractPolyester (PET) nanocomposite fibers were spun by adding master batches of linear low‐density polyethylene (LLDPE) loaded with Montmorillonite (MMT) nanoclay after compatibilizing the PET and LLDPE. The spun fibers showed increased thermal stability as well as flame retardancy, which increased progressively with the amount of nanoclay loaded into the fiber. There is slight decrease in tensile strength of the fiber accompanied by decrease in elongation % indicating addition of nanoclay makes the filaments stiffer. The onset of crystallization temperature occurred at higher temperature in case of composite fibers than on the neat PET fiber because of nucleating effect of nanoclay. The dyeability of the fibers was not affected and also had very little impact on the flame retardancy of the fiber. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Investigation on particular phase morphology of immiscible polyamide 12 and polystyrene blends prepared via anionic ring‐opening polymerization
Authors: Wu Bozhen , Xie Tingxiu , Yang Guisheng 
Published: March 2012

AbstractIn this article, the particular phase morphology of immiscible polyamide 12/polystyrene (PA12/PS) blends prepared via in situ anionic ring‐opening polymerization of laurolactam (LL) in the presence of polystyrene (PS) was investigated. Scanning electron microscopy (SEM) and Fourier Transform infrared Spectroscopy (FTIR) were used to analyze the morphology of the blends. The results show that the PS is dispersed as small droplets in the continuous matrix of PA12 when PS content is 5 wt%. However, when the PS content is higher than 10 wt%, two particular phase morphologies appeared. Firstly, dispersed PS‐rich particles with the spherical inclusions of PA12 can be found when PS content is between 10 and 15 wt%. Then the phase inversion occurred (the phase morphology of the PA12/PS blends changed from the PS dispersed/PA12 matrix to PA12 dispersed/PS matrix system) when PS content is 20 wt% or higher, which is unusual for polymer blends prepared via conventional methods such as mixing, hydrolytic polycondensation and so on. The formation of this particular phase morphology development was simply elucidated via a phase inversion mechanism. Furthermore, the stability of the phase morphology of the PA12/PS blends after annealing at 230°C was also investigated via SEM. POLYM. ENG. SCI., 52:1831–1838, 2012. © 2012 Society of Plastics Engineers
Fast and efficient manufacturing method of one‐ and two‐dimensional polyethylene terephthalate transmission diffraction gratings by direct laser interference patterning
Authors: Perez‐Hernandez Heidi , Lasagni Andrés F. 
Published: March 2012

AbstractOne‐ and two‐dimensional diffraction gratings were fabricated on commercial polyethylene terephthalate (PET) film by two beam direct laser interference patterning (DLIP) method using a pulse laser (10 ns) with a wavelength of 266 nm. The relative diffraction efficiency of the structured specimens (at 633 nm) in transmission mode was measured and correlated with the topological characteristics of the structured PET substrates. The obtained diffraction gratings made by DLIP show better or similar diffraction efficiencies when compared with the reported efficiency of gratings made by other methods (up to 42.5% for 1 μm arrays), and can be fabricated on large areas in very short processing times (up to 18 cm2/s). POLYM. ENG. SCI., 52:1903–1908, 2012. © 2012 Society of Plastics Engineers
Rubber modification of unsaturated polyester resin with core–shell rubber particles: Effect of shell composition
Authors: Ahmadi M. , Moghbeli M. R. , Shokrieh M. M. 
Published: March 2012

AbstractPoly(butyl acrylate)/poly(vinyl acetate‐co‐methyl methacrylate) PBA/P(VAc‐co‐MMA) core–shell rubber particles with various shell compositions, i.e., VAc/MMA weight ratios, were used to toughen unsaturated polyester. The morphology and surface‐free energy of the rubber particles were determined by transmission electron microscopy (TEM) and contact angle measurements, respectively. The effect of shell structure on the dispersion state of rubber particles inside the unsaturated polyester resin was studied by scanning electron microscopy and TEM. Increasing MMA units in the shell changed the particle dispersion state from small agglomerates or globally well‐dispersed particles to large aggregates in the cured‐resin matrix. For the blends that contain 5 wt% rubber, the highest un‐notched impact toughness, stress‐intensity factor (KIC), and fracture energy (GIC) were observed for the blend containing PVAc shell particles. The results showed that by increasing the particle level from 5 to 10 wt%, the highest KIC and GIC values were obtained for the blend containing rubber particles with VAc/MMA (80/20 wt/wt) copolymer shell. The crack‐tip damage zone in the neat and rubber‐modified unsaturated polyester resins was observed by means of transmission optical microscopy. In addition, using PVAc shell particles exhibited a minimum reduction in the volume shrinkage and tensile properties of the rubber‐modified resin. POLYM. ENG. SCI., 52:1928–1937, 2012. © 2012 Society of Plastics Engineers
Distinct work‐related, clinical and psychological factors predict return to work following treatment in four different cancer types
Authors: Cooper Alethea F. , Hankins Matthew , Rixon Lorna , Eaton Emma , Grunfeld Elizabeth A. 
Published: March 2012

AbstractObjectiveMany factors influence return to work (RTW) following cancer treatment. However specific factors affecting RTW across different cancer types are unclear. This study examined the role of clinical, sociodemographic, work and psychological factors in RTW following treatment for breast, gynaecological, head and neck, and urological cancer.MethodsA 12‐month prospective questionnaire study was conducted with 290 patients. Cox regression analyses were conducted to calculate hazard ratios (HR) for time to RTW.ResultsBetween 89–94% of cancer survivors returned to work. Breast cancer survivors took the longest to return (median 30 weeks), and urology cancer survivors returned the soonest (median 5 weeks). Earlier return among breast cancer survivors was predicted by a greater sense of control over their cancer at work (HR 1.2; 95% CI: 1.09–1.37) and by full‐time work (HR 2.1; CI: 1.24–3.4). Predictive of a longer return among gynaecological cancer survivors was a belief that cancer treatment may impair ability to work (HR 0.75; CI: 0.62–0.91). Among urological cancer survivors constipation was predictive of longer RTW (HR 0.99; CI: 0.97–1.00), whereas undertaking flexible working was predictive of returning sooner (HR 1.70; CI: 1.07–2.7). Head and neck cancer survivors who perceived greater negative consequences of their cancer took longer to return (HR 0.27; CI: 0.11–0.68). Those reporting better physical functioning returned sooner (HR1.04; CI: 1.01–1.08).ConclusionA different profile of predictive factors emerged for the four cancer types. In addition to optimal symptom management and workplace adaptations, the findings suggest that eliciting and challenging specific cancer and treatment‐related perceptions may facilitate RTW. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of point mutations on protein structure are nonexponentially distributed
Authors: Arodź Tomasz , Płonka Przemysław M. 
Published: March 2012

AbstractInspection of structure changes in proteins borne by altering their sequences brings understanding of physics, functioning and evolution of existing proteins, and helps engineer modified ones. On single amino acid substitutions, the most frequent mutation type, shifts in backbone conformation are typically small, raising doubts if and how such minor modifications could drive evolutionary divergence. Here, we report that the distribution of magnitudes of structure change on such substitutions is heavy‐tailed — whereas protein structures are robust to most substitutions, changes much larger than average occur with raised odds compared to what would be expected for exponential distribution with the same mean. This nonexponential behavior allows for reconciling the apparent contradiction between the observed conservation of protein structures and the substantial evolutionary plasticity implied in their diversity. The presence of the heavy tail in the distribution promotes structure divergence, facilitating exploration of new functionality, and conformations within folds, as well as exploration of structure space for new folds. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Sann: Solvent accessibility prediction of proteins by nearest neighbor method
Authors: Joo Keehyoung , Lee Sung Jong , Lee Jooyoung 
Published: March 2012

AbstractWe present a method to predict the solvent accessibility of proteins which is based on a nearest neighbor method applied to the sequence profiles. Using the method, continuous real‐value prediction as well as two‐state and three‐state discrete predictions can be obtained. The method utilizes the z‐score value of the distance measure in the feature vector space to estimate the relative contribution among the k‐nearest neighbors for prediction of the discrete and continuous solvent accessibility. The Solvent accessibility database is constructed from 5717 proteins extracted from PISCES culling server with the cutoff of 25% sequence identities. Using optimal parameters, the prediction accuracies (for discrete predictions) of 78.38% (two‐state prediction with the threshold of 25%), 65.1% (three‐state prediction with the thresholds of 9 and 36%), and the Pearson correlation coefficient (between the predicted and true RSA's for continuous prediction) of 0.676 are achieved An independent benchmark test was performed with the CASP8 targets where we find that the proposed method outperforms existing methods. The prediction accuracies are 80.89% (for two state prediction with the threshold of 25%), 67.58% (three‐state prediction), and the Pearson correlation coefficient of 0.727 (for continuous prediction) with mean absolute error of 0.148. We have also investigated the effect of increasing database sizes on the prediction accuracy, where additional improvement in the accuracy is observed as the database size increases. The SANN web server is available at http://lee.kias.re.kr/∼newton/sann/.Proteins 2012; © 2012 Wiley Periodicals, Inc.
Idealized numerical simulations of quasi‐stationary convective systems over the Northwestern Mediterranean complex terrain
Authors: Bresson E. , Ducrocq V. , Nuissier O. , Ricard D. , de Saint‐Aubin C. 
Published: March 2012

AbstractNorthwestern Mediterranean coastal regions are frequently affected by torrential rainfall associated with quasi‐stationary mesoscale convective systems (MCSs). The present work examines how the characteristics of a conditionally unstable flow impinging on the coastal complex terrain of the Northwestern Mediterranean can affect the location and intensity of quasi‐stationary MCSs. The study is based on idealized simulations, but including the major ingredients of Northwestern Mediterranean heavy precipitation events: a moist conditionally unstable marine flow of about 100 km width facing the true terrain, composed of the Massif Central surrounded by the Alps and the Pyrenees.We find that MCSs are located upstream of the mountain range with a slow flow, whereas with a rapid flow the heaviest precipitation is over the Massif Central slopes. In a similar way, when the lateral environment is drier the heaviest precipitation is located upstream whereas a humid environment favours precipitation over the slopes. The dominant lifting mechanism is strongly related to the location of the system: (1) direct orographic triggering for systems over mountain slopes and (2) cold‐pool triggering for upstream systems. In addition, the neighbouring mountains interplay through deflection of the flow and induced low‐level convergence favoured by slow or dry lateral environments and through cold‐pool blocking within valleys. Copyright © 2012 Royal Meteorological Society
Formation of Lipid Sheaths around Nanoparticle‐Supported Lipid Bilayers
Authors: Ahmed Selver , Savarala Sushma , Chen Yanjing , Bothun Geoffrey , Wunder Stephanie L. 
Published: March 2012

AbstractHigh‐surface‐area nanoparticles often cluster, with unknown effects on their cellular uptake and environmental impact. In the presence of vesicles or cell membranes, lipid adsorption can occur on the nanoparticles, resulting in the formation of supported lipid bilayers (SLBs), which tend to resist cellular uptake. When the amount of lipid available is in excess compared with that required to form a single‐SLB, large aggregates of SLBs enclosed by a close‐fitting lipid bilayer sheath are shown to form. The proposed mechanism for this process is one where small unilamellar vesicles (SUVs) adsorb to aggregates of SLBs just above the gel‐to‐liquid phase transition temperature, Tm, of the lipids (as observed by dynamic light scattering), and then fuse with each other (rather than to the underlying SLBs) upon cooling below Tm. The sacks of SLB nanoparticles that are formed are encapsulated by the contiguous close‐fitting lipid sheath, and precipitate below Tm, due to reduced hydration repulsion and the absence of undulation/protrusion forces for the lipids attached to the solid support. The single‐SLBs can be released above Tm, where these forces are restored by the free lipid vesicles. This mechanism may be useful for encapsulation/release of drugs/DNA, and has implications for the toxic effects of nanoparticles, which may be mitigated by lipid sequestration.
The Importance of Dehydration in Determining Ion Transport in Narrow Pores
Authors: Richards Laura A. , Schäfer Andrea I. , Richards Bryce S. , Corry Ben 
Published: March 2012

AbstractThe transport of hydrated ions through narrow pores is important for a number of processes such as the desalination and filtration of water and the conductance of ions through biological channels. Here, molecular dynamics simulations are used to systematically examine the transport of anionic drinking water contaminants (fluoride, chloride, nitrate, and nitrite) through pores ranging in effective radius from 2.8 to 6.5 Å to elucidate the role of hydration in excluding these species during nanofiltration. Bulk hydration properties (hydrated size and coordination number) are determined for comparison with the situations inside the pores. Free energy profiles for ion transport through the pores show energy barriers depend on pore size, ion type, and membrane surface charge and that the selectivity sequence can change depending on the pore size. Ion coordination numbers along the trajectory showed that partial dehydration of the transported ion is the main contribution to the energy barriers. Ion transport is greatly hindered when the effective pore radius is smaller than the hydrated radius, as the ion has to lose some associated water molecules to enter the pore. Small energy barriers are still observed when pore sizes are larger than the hydrated radius due to re‐orientation of the hydration shell or the loss of more distant water. These results demonstrate the importance of ion dehydration in transport through narrow pores, which increases the current level of mechanistic understanding of membrane‐based desalination and transport in biological channels.
Excessive Sodium Ions Delivered into Cells by Nanodiamonds: Implications for Tumor Therapy
Authors: Zhu Ying , Li Wenxin , Zhang Yu , Li Jing , Liang Le , Zhang Xiangzhi , Chen Nan , Sun Yanhong , Chen Wen , Tai Renzhong , Fan Chunhai , Huang Qing 
Published: March 2012

AbstractNanodiamonds (NDs) possess many excellent physical and chemical properties that make them attractive materials for applications in biomedicine. In this paper, the adsorption and delivery of a large amount of sodium ions into the cell interior by NDs in serum‐free medium is demonstrated. The excess sodium ions inside the cells induce osmotic stresses followed by cell swelling and an increase in the intracellular levels of calcium and reactive oxygen species (ROS), which leads to severe cellular damage. In complete culture medium, however, serum proteins wrapped around the NDs effectively prevent the sodium ions from adsorbing onto the NDs, and thus the NDs show no cytotoxicity. This work is the first to elaborate on the correlation between the sodium ions adsorbed on the nanomaterials and their bio‐effects. Excessive ions delivered into cells by NDs might have potential applications in tumor therapy.
Strength reduction factor demands for building structures under different seismic levels
Authors: Thuat Dinh Van 
Published: March 2012

SUMMARYDamage levels of building structures under a design earthquake are closely related to the assigned values of strength reduction factors. This paper is to investigate the strength reduction factor demands of building structures that were designed considering various earthquake ground intensity levels, soil ground types, and strength reduction factors. In the investigation, a huge number of rigorous nonlinear inelastic dynamic response analyses of various analytical models of five‐story and nine‐story frame structures were conducted under various generated ground motions with variations in phrase angles but identical response spectral acceleration amplitudes. Various scaled earthquake records were also considered for evidence of the investigation. The obtained results showed that when the same values of the strength reduction factors were used for determination of the design lateral seismic forces, the damage and reliability level demands of the structures designed for moderate seismic areas were much less than those for severe seismic ones. As a result, it is proposed that the strength reduction factor demands given in design codes can additionally be expressed in a linear relation of the maximum ground acceleration. Copyright © 2012 John Wiley & Sons, Ltd.
Monochromatic waves in saturated porous materials with anisotropic permeability
Authors: Wilmanski K. 
Published: March 2012

AbstractIn the paper we investigate the propagation conditions of monochromatic waves in a saturated poroelastic material described by a generalization of Biot's equations. This generalization concerns anisotropic properties of the permeability. Mechanical properties of the system are assumed to be described by isotropic constitutive relations but the permeability is given in terms of a tensor of tortuosity. In particular we analyze the propagation in one of the principal directions of this tensor. For this particular monochromatic wave we show the existence of the purely transversal wave. We prove the existence of two modes of such waves and investigate their behavior as functions of the frequency. A practical application in nondestructive testing of anisotropic materials is indicated.
Bending of a bi‐material cantilever beam, with consideration of the role of the interfacial shearing stress
Authors: Suhir E. , Nicolics J. 
Published: March 2012

AbstractA simple, easy‐to‐use and physically meaningful analytical (“mathematical”) model for the prediction of the interfacial shearing stress in, and the maximum bow of, a bi‐material cantilever beam is developed. The beam experiences bending under the action of a lateral concentrated force applied to its free end. It is shown that the effect of the longitudinal interfacial compliance of the beam should be considered for short beams with not‐very‐stiff interfaces.
Incidence of cervical intraepithelial neoplasia in a cohort of HIV‐infected women
Authors: Araújo Angela C.L. , Carvalho Nara O. , Teixeira Nara C. , Souza Tatiana T. , Murta Érica D. , Faria Iwens M. , Corrêa Christine M. , Lima Maria I.M. , del Castillo Dora M. , Melo Victor H. 
Published: March 2012

AbstractObjectiveTo assess cervical intraepithelial neoplasia (CIN) incidence in HIV‐positive women and the risk factors for these lesions.MethodsA retrospective and longitudinal cohort study was conducted from June 13, 1997, to December 18, 2009. At the first visit, the 348 participants had a normal cytologic finding but a negative Schiller test result, or an abnormal cytologic finding but no histologic diagnosis of CIN. Infection with HPV was detected by polymerase chain reaction. The main outcome measure was CIN incidence.ResultsDuring a mean follow‐up of 40 months, 47 women (13.5%) developed CIN, for an incidence of 4.1 cases per 100 person‐years of follow‐up. The HPV prevalence was 68.1%, 42 women (89.4%) developed CIN 1, and no invasive cervical cancers were identified. On multivariate analysis, women younger than 19 years at first sexual intercourse (RR, 2.6; 95% CI, 1.24–5.35) and women who had never used antiretrovirals or used them only during pregnancy (RR, 2.3; 95% CI, 1.31–4.19) were at higher risk for CIN.ConclusionThe CIN incidence was low despite the high HPV prevalence. Being younger than 19 years at first sexual intercourse and not using antiretroviral medications were found to be the main risk factors for CIN.
The effects of retail channel integration through the use of information technologies on firm performance
Authors: Oh Lih‐Bin , Teo Hock‐Hai , Sambamurthy Vallabh 
Published: March 2012

AbstractThe ability of information technologies (ITs) to integrate activities and offerings across multiple channels offers a promising opportunity for retail firms to enhance their relationship with their customers and firm performance. Consumers value the flexibility to learn about the available offerings, complete their orders and obtain customer service across different channels in a convenient and integrated manner. Therefore, the retail industry has begun to use IT extensively to automate and integrate business processes across their traditional and online channels. This study examines the impacts of the use of IT by retail firms in integrating channel activities for selling to customers. Our research model argues that retail channel integration through IT should enhance the efficiency and innovation of a retail firm. In turn, these improvements should enhance their overall performance. We also propose that the environmental dynamism would moderate the effects of improvements in efficiency and innovation on firm performance. We draw upon recent theories in organizational resource integration and organizational learning to develop our research model and hypotheses. Based on survey data from 125 multichannel retailers in Singapore, we find that retail channel integration through the use of IT allows firms to not only be efficient in delivering the current offerings, but also be innovative in creating future offerings. Further, we find that environmental dynamism does positively moderate the effects of innovation ability on performance. Our results provide managerial insights for firms involved in digital integration not only in the retail sector but also in other service industries. These findings could also serve as a foundation for further research on service operations management for firms with both physical and online operations.