bluuebunny/crossref_metadata_2025_split huggingface dataset:
New copolymer of poly(N‐vinylcarbazole) and poly(p‐phenylenevinylene) for optoelectronic devices
Authors: Mbarek Mohamed , Massuyeau Florian , Duvail Jean‐Luc , Wery Jany , Faulques Eric , Alimi Kamel 
Published: June 2013

ABSTRACTA novel diblock copolymer based on poly(N‐vinylcarbazole) PVK and poly(p‐phenylenevinylene) (PPV) precursor was synthesized by oxidative cross‐linking. The grafting of PPV with PVK moieties was elucidated by infrared absorption analysis. A structural study by X‐ray diffraction and a morphological study of the copolymer by scanning and transmission electron microscopy reveal a multiscale one‐dimensional self‐organization both at the molecular and at the sub‐micrometric level. The resulting copolymer exhibits original optical properties compared to those of PVK and PPV ones and presents an improved thermal behavior. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2839–2847, 2013
Pebax‐1657 nanocomposite membranes incorporated with nanoparticles/colloids/carbon nanotubes for CO2/N2 and CO2/H2 separation
Authors: Yu Bing , Cong Hailin , Li Zejing , Tang Jianguo , Zhao Xiu Song 
Published: June 2013

ABSTRACTPebax‐1657 is known as a promising polymeric membrane material for CO2/N2 and CO2/H2 separation. In order to further improve its gas separation performance and reinforce the membrane, different fillers including silica nanoparticles, polystyrene (PS) colloids, and carbon nanotubes (CNTs) were incorporated into the polymer matrix to form nanocomposite membranes. The nanocomposite membranes of Pebax‐1657/silica and Pebax‐1657/PS colloid had a decreased CO2 permeability and selectivity over N2 or H2 compared to the pure Pebax‐1657 membrane, while the Pebax‐1657/CNT nanocomposite membranes had an increased CO2 permeability, retaining similar CO2/N2 or CO2/H2 selectivity compared to the pure polymer membrane. The CO2 permeability increased with increasing CNT content and reached a maximum at 5 wt % CNTs. The CNT‐enhanced gas permeability was attributed to the increase in gas diffusivity. The tensile modulus of Pebax‐1657 increased 43% after adding 5 wt % single‐wall CNTs (SWNTs), and increased 24% after adding 5 wt % multi‐wall CNTs (MWNTs). Thus, it is feasible to add CNTs to Pebax‐1657 membranes for improved mechanical strength and gas separation performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2867–2876, 2013
Processing and characterization of supercritical CO2batch foamed poly(lactic acid)/poly(ethylene glycol) scaffold for tissue engineering application
Authors: Zhang Wenhao , Chen Binyi , Zhao Haibin , Yu Peng , Fu Dajiong , Wen Jinsong , Peng Xiangfang 
Published: June 2013

ABSTRACTBoth poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) are biodegradable polymers, blending PLA with PEG is expected to toughen PLA matrix while maintaining its biodegradability. In this study, PLA/PEG blends in different ratios were prepared through triple‐screw extruder, and the foaming behavior was investigated using supercritical carbon dioxide as physical blowing agent. The mechanical, thermal, rheological properties, and crystallization behavior were also studied. By the incorporation of PEG, the impact strength of the PLA/PEG blends improved by 98% with the specimens fractured in a ductile mode. The crystallization process of the blends was accelerated, and the crystallinity was significantly increased to 45.1%. The viscoelasticity of the PLA/PEG matrix was weakened, and the cells tended to break at the cell wall during cell expansion; thus, a highly interconnected structure with a maximum porosity of 82.3% was obtained. Moreover, the PLA/PEG blends exhibited higher cell densities and smaller cell size, compared to their neat counterparts. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3066–3073, 2013
Outdoor weathering of polyamide and polyester ropes used in fall arrest equipment
Authors: Arrieta Carlos , Dong Yingying , Lan André , Vu‐Khanh Toan 
Published: June 2013

ABSTRACTIn this work, the effect of natural climatic aging on two ropes made from polyamide 6 (PA6) and poly(ethylene terephthalate) (PET) was evaluated. Samples of rope from both materials underwent a continuous outdoor aging treatment spanning 6 months in Montreal's weather. Tensile tests carried out on aged PA6 ropes showed an increase in ultimate strain and a decrease in breaking force when compared with as‐received values, while PET ropes exhibited a slight increase in ultimate strain as their breaking force remained unchanged. FTIR analyses of aged PET samples revealed a new absorption band in the hydroxyl region ascribed to the OH stretching vibrations of carboxylic acid end groups. FTIR quantitative analyses of the absorption bands in the carbonyl region of aged PA6 spectra displayed an increase in intensity that indicates the occurrence of chemical degradation reactions. The degree of crystallinity of PA6, calculated from differential scanning calorimetry data, was found to increase after the weathering treatment, a result confirmed by X‐ray diffraction analyses. The higher crystalline fraction is believed to entail an increase in the density of PA6 fibers, which give rise to the length reduction seen in PA6 ropes after the aging treatment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3058–3065, 2013
Miscibility, water uptake, ion exchange capacity, conductivity and dielectric studies of poly(methyl methacrylate) and cellulose acetate blends
Authors: Jois H. S. Sreekantha , Bhat Denthaje Krishna 
Published: June 2013

ABSTRACTIn the last few decades, polymer blends with good miscibility and conductivity have been the focus of study for material scientists. Here, polymer blends of Poly(methyl methacrylate) (PMMA) and Cellulose acetate (CA) of varying blend compositions have been prepared by solution casting method and their miscibility, water uptake, ion exchange capacity (IEC) proton conductivity, and dielectric properties have been studied. Dimethyl formamide (DMF) was used as solvent. Fourier transform infrared spectra (FTIR) and Differential scanning calorimetry (DSC) measurements have been used to analyze the miscibility of the blends. Up to 50/50 PMMA/CA, water uptake showed an increasing trend and for other compositions the value decreased. Ion exchange capacity and conductivity of the blends decreased with increase in PMMA content of the blends. The variations in the blend properties have been attributed to the presence of specific interactions and exchangeable groups in the blend system. The proton conductivity of the blends is in the order of 10−3 S cm−1. Impedance analysis of the blends indicated the absence of any relaxation phenomenon in the blend system. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3074–3081, 2013
Effects of postcure temperature variation on hygrothermal‐mechanical properties of an out‐of‐autoclave polymer composite
Authors: Vo Tien , Vora Khalil , Minaie Bob 
Published: June 2013

ABSTRACTThe effects of cure temperature variation on the properties of an out‐of‐autoclave polymer composite manufactured using Cycom 5320 8HS prepreg were investigated using different postcure temperatures of a two‐stage cure cycle. In addition, the effects of adverse environmental conditions on the cure temperature variation were studied by conditioning the samples in an environmental chamber until they reached moisture equilibrium. The state of cure was obtained using a differential scanning calorimeter and dynamic mechanical analyzer. The mechanical properties were obtained using short‐beam shear (SBS) and combined loading compression (CLC) test methods. The state of cure obtained showed increases in total heat of reaction, degree of cure, and glass transition temperature as the postcure temperature increased. The SBS and CLC strengths showed an increasing trend as postcure temperature increased. Good correlations were obtained between the material's cure temperatures, state of cure, and mechanical properties for room temperature dry and hot wet conditions. The study showed that the state of cure can be used to define, monitor, and verify the cure quality. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3090–3097, 2013
Distribution and extirpation of pigs in Pacific Islands: a case study from Palau
Authors: Clark Geoffrey , Petchey Fiona , Hawkins Stuart , Reepmeyer Christian , Smith Ian , Masse W. Bruce 
Published: June 2013

AbstractNeolithic arrival in the Pacific involved, as in other parts of the world, the translocation of domesticated plants and animals by pottery‐making cultures in prehistory. Globally uncommon, though, was the abandonment of pottery on some islands and the extirpation of the pig (Sus scrofa/verrucosus) and dog (Canis familiaris) – the two largest mammalian quadrupeds introduced to Oceania – from the subsistence and cultural systems. This paper examines the extirpation of pigs from the Palau Islands as a case study to understand why an important domesticate has such an uneven prehistoric distribution. When suids are fed agricultural produce required to sustain the human population, it has been proposed that competition and extirpation will result, especially on small islands with limited arable land. However, pigs are considered problem animals in many environments because of the damage they cause to horticultural production, particularly the effects of free‐range pigs on gardens and plantations. It is suggested that extirpation and low‐level animal keeping are a response to the threat that pigs pose to plant food yields and social relations.
Somatic Hypermutations Confer Rheumatoid Factor Activity in Hepatitis C Virus–Associated Mixed Cryoglobulinemia
Authors: Charles Edgar D. , Orloff Michael I. M. , Nishiuchi Eiko , Marukian Svetlana , Rice Charles M. , Dustin Lynn B. 
Published: June 2013

ObjectiveHepatitis C virus (HCV) is the most frequent cause of mixed cryoglobulinemia (MC), which is characterized by endothelial deposition of rheumatoid factor (RF)–containing immune complexes and end‐organ vasculitis. MC is a lymphoproliferative disorder in which B cells express RF‐like Ig, yet its precise antigenic stimulus is unknown. We have proposed that IgG–HCV immune complexes stimulate B cell expansion and somatic hypermutation (SHM)–induced affinity maturation in part via engagement of an RF‐like B cell receptor. This study was undertaken to test the hypothesis that SHM augments RF activity.MethodsRFs cloned from single B cells from 4 patients with HCV‐associated MC (HCV‐MC) were expressed as IgM, IgG, or IgG Fab. Selected Ig were reverted to germline. RF activity of somatically mutated Ig and germline‐reverted Ig was determined by enzyme‐linked immunosorbent assay.ResultsIg with SHM had RF activity, with the preference for binding being highest for IgG1, followed by IgG2 and IgG4, and lowest for IgG3, where there was no detectable binding. In contrast, reverted germline IgG exhibited markedly diminished RF activity. Competition with 1 μg/ml of protein A abrogated RF activity, suggesting specificity for IgG Fc. Swapping of mutated heavy‐chain pairs and light‐chain pairs also abrogated RF activity, suggesting that context‐specific pairing of appropriate IgH and Igκ, in addition to SHM, is necessary for RF activity.ConclusionSHM significantly contributes to RF activity in HCV‐MC patients, suggesting that autoreactivity in these patients arises through antigen‐dependent SHM, as opposed to nondeletion of autoreactive germline Ig.
Error rating tool to identify and analyse technical errors and events in laparoscopic surgery
Authors: Bonrath E M , Zevin B , Dedy N J , Grantcharov T P 
Published: June 2013

Abstract

Background
Surgical error analysis is essential for investigating mechanisms of errors, events and adverse outcomes. Furthermore, it provides valuable information for formative feedback and quality control. The aim of the present study was to design and validate a technical error rating tool in laparoscopic surgery.

Methods
The framework consisted of nine task groups and four error modes. Unedited videos of laparoscopic Roux-en-Y gastric bypass procedures were rated and analysed. The Objective Structured Assessment of Technical Skill (OSATS) global rating scale was used to assess technical skills. The incidence of errors and of injuries (events) were the main outcome measures, and were used to calculate the reliability, and construct and concurrent validity of the instrument.

Results
Two observers analysed 25 procedures. Inter-rater reliability was high regarding total number of errors (intraclass correlation coefficient (ICC) 0·90) and events (ICC 0·85). The median (interquartile range) error rate was 35 (26–44) and the event rate 3 (2–3) per procedure. Error frequencies and OSATS scores correlated significantly in all operative steps (rs = − 0·75 to −0·40, P = &lt;0·001–0·046). Surgeons demonstrating high OSATS scores had lower median (i.q.r.) error rates than surgeons with low scores in three of four steps: measuring bowel (4 (2–7) versus 10 (9–11); P = 0·004), jejunojejunostomy formation (5 (2–6) versus 10 (9–11); P = 0·001) and pouch formation (4 (3–6) versus 9 (5–12); P = 0·004).

Conclusion
The proposed error rating tool allows an objective and reliable assessment of operative performance in laparoscopic gastric bypass procedures.
A baseline process for the production, recovery, and purification of bacterial influenza vaccine candidates
Authors: Sánchez‐Arreola Pamela B. , López‐Uriarte Salvador , Marichal‐Gallardo Pável A. , González‐Vázquez Juan C. , Pérez‐Chavarría Roberto , Soto‐Vázquez Pedro , López‐Pacheco Felipe , Ramírez‐Medrano Alicia , Rocha‐Pizaña María R. , Álvarez Mario M. 
Published: June 2013

The current commercial system for influenza vaccine production depends on the culture of virus in embryonated eggs—a strategy that is both costly and poorly scalable. Consequently, a sudden pandemic event with a demand for millions of vaccine doses in a short time could readily overwhelm the available world production capacity. In this communication, we present a process that uses Escherichia coli for scalable production of recombinant vaccine candidates against influenza. A monomeric and a dimeric fragment of hemagglutinin of the influenza A H1N1/2009 virus were successfully expressed in a BL21 (DE3) pLysS variety of C41 E. coli. We present results from batch processes where induction is made with isopropyl thiogalactoside and from fed‐batch experiments where expression is induced using lactose/glucose pulses. Concentrations in the range of 1.188–0.605 g/L of recombinant protein were observed in 2‐L stirred tank bioreactors. The genetic construct included an N‐terminal histidine tag sequence that facilitated recovery, purification, and proper refolding of the vaccine candidate by affinity chromatography in columns loaded with Ni+2. The proteins produced by this strategy selectively and specifically recognizes antibodies from patients diagnosed as positive to influenza A H1N1/2009. Overall protein recovery yields between 30.0 and 34.7% were typically observed. Based on these yields, a production of 4.6 × 103 doses L−3 day−1 is feasible. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:896–908, 2013
Sexual Abuse and Drug Abuse Among Homeless Children in Ahvaz, Iran
Authors: Baratvand Mahmood , Soodani Mansour , Zarei Eghbal , Asadollahi Abdolrahim 
Published: June 2013

This study conducted in the Ahvaz Correction Centre (ACC) in 2008 explored the relationship between variables such as drug abuse and sexual abuse and homelessness among children. The sample consisted of 28 children (mean age = 14.5 years) selected by snowball sampling. Data were collected by social workers practising in the ACC. The mean age of children beginning life on the streets was 11.71 years, and the group lived on the streets, on average, for 2.69 years. The group was held in the ACC, on average, for 11.68 months. Sexual abuse and drug abuse were common behaviours among the children, and robust relationships were found between these variables and age during the first experience of shelter‐seeking. The children had committed crimes such as pick‐pocketing, sexual abuse against other children, drug addiction and drug trafficking. It was found that many of their families had a history of conflict and/or divorce and most children had a family member with a criminal record. The children were also disadvantaged by a lack of education, with illiteracy common among them and their parents. A significant relationship was established between the children's family situation and the length of their detention (r = 0.47), while children who maintained links with their family members were less likely to return to crime after release from the centre. Copyright © 2013 John Wiley & Sons, Ltd.‘A history of conflict and/or divorce and most had a family member with a criminal record’Key Practitioner Messages

In this sample of street children in Iran, half had begun living on the streets before the age of 11 years.
A majority of the children had engaged in criminal behaviours, particularly the misuse of drugs.
Many of these children had either perpetrated or been victims of sexual abuse while living on the streets.
Criminality in the family of origin was a common finding.
A Langevin Canonical Approach to the Dynamics of Chiral Systems: Populations and Coherences
Authors: Peñate‐Rodríguez Helen Clara , Dorta‐Urra Anais , Bargueño Pedro , Rojas‐Lorenzo German , Miret‐Artés Salvador 
Published: June 2013

ABSTRACTA canonical framework for chiral two–level systems coupled to a bath of harmonic oscillators is developed to extract, from a stochastic dynamics, the thermodynamic equilibrium values of both the population difference and coherences. The incoherent and coherent tunneling regimes are analyzed for an Ohmic environment in terms of a critical temperature defined by the maximum of the heat capacity. The corresponding numerical results issued from solving a non‐linear coupled system of equations are fitted to approximate path–integral analytical expressions beyond the so‐called non‐interacting blip approximation in order to determine the different time scales governing both regimes. Chirality 25:514–520, 2013. © 2013 Wiley Periodicals, Inc.
Hilar interneuron vulnerability distinguishes aged rats with memory impairment
Authors: Spiegel Amy M. , Koh Ming Teng , Vogt Nicholas M. , Rapp Peter R. , Gallagher Michela 
Published: June 2013

ABSTRACTHippocampal interneuron populations are reportedly vulnerable to normal aging. The relationship between interneuron network integrity and age‐related memory impairment, however, has not been tested directly. That question was addressed in the present study using a well‐characterized model in which outbred, aged, male Long‐Evans rats exhibit a spectrum of individual differences in hippocampal‐dependent memory. Selected interneuron populations in the hippocampus were visualized for stereological quantification with a panel of immunocytochemical markers, including glutamic acid decarboxylase‐67 (GAD67), somatostatin, and neuropeptide Y. The overall pattern of results was that, although the numbers of GAD67‐ and somatostatin‐positive interneurons declined with age across multiple fields of the hippocampus, alterations specifically related to the cognitive outcome of aging were observed exclusively in the hilus of the dentate gyrus. Because the total number of NeuN‐immunoreactive hilar neurons was unaffected, the decline observed with other markers likely reflects a loss of target protein rather than neuron death. In support of that interpretation, treatment with the atypical antiepileptic levetiracetam at a low dose shown previously to improve behavioral performance fully restored hilar SOM expression in aged, memory‐impaired rats. Age‐related decreases in GAD67‐ and somatostatin‐immunoreactive neuron number beyond the hilus were regionally selective and spared the CA1 field of the hippocampus entirely. Together these findings confirm the vulnerability of hippocampal interneurons to normal aging and highlight that the integrity of a specific subpopulation in the hilus is coupled with age‐related memory impairment. J. Comp. Neurol. 521:3508‐3523, 2013. © 2013 Wiley Periodicals, Inc.
Anterior insular cortex and emotional awareness
Authors: Gu Xiaosi , Hof Patrick R. , Friston Karl J. , Fan Jin 
Published: June 2013

ABSTRACTThis paper reviews the foundation for a role of the human anterior insular cortex (AIC) in emotional awareness, defined as the conscious experience of emotions. We first introduce the neuroanatomical features of AIC and existing findings on emotional awareness. Using empathy, the awareness and understanding of other people's emotional states, as a test case, we then present evidence to demonstrate: 1) AIC and anterior cingulate cortex (ACC) are commonly coactivated as revealed by a meta‐analysis, 2) AIC is functionally dissociable from ACC, 3) AIC integrates stimulus‐driven and top‐down information, and 4) AIC is necessary for emotional awareness. We propose a model in which AIC serves two major functions: integrating bottom‐up interoceptive signals with top‐down predictions to generate a current awareness state and providing descending predictions to visceral systems that provide a point of reference for autonomic reflexes. We argue that AIC is critical and necessary for emotional awareness. J. Comp. Neurol. 521:3371‐3388, 2013. © 2013 Wiley Periodicals, Inc.
Functional allocation of synaptic contacts in microcircuits from rods via rod bipolar to AII amacrine cells in the mouse retina
Authors: Tsukamoto Yoshihiko , Omi Naoko 
Published: June 2013

ABSTRACTRetinal microcircuits for night vision at the absolute threshold are required to relay a single‐photon rod signal reliably to ganglion cells via rod bipolar (RB) cells and AII amacrine cells. To assess the noise reduction of intercellular signal transmission in this rod‐specific pathway, we quantified its synaptic connectivity by 3D reconstruction of a series of electron micrographs. In most cases (94%), each rod made ribbon synaptic contacts onto two adjacent RB cells. Conversely, each RB cell was contacted by 25 rods. Each RB axon terminal contacted four or five AII amacrine cells via 53 ribbon synapses. Thus, the signal from one rod may be represented as 106 replicates at two RB axons. Moreover, the two adjacent RB cells contacted two to four AII amacrine cells in common, where the signals relayed by two RB cells were reunited. In more detail, over 50% of each RB output was directed predominantly to a single, preferred AII amacrine cell, although each RB cell also separately contacted another one to three AII amacrine cells. Most of the replicate signals at two RB axons were collected on a few AII amacrine cells via reunions, dominant connections, and electrical coupling by AII–AII gap junctions. Thus the original signal may be reliably represented by signal amplification with focal accumulation without gathering unnecessary noise from a wide surrounding area. This allocation of RB–AII synaptic contacts may serve as the structural basis for the physiological properties of the AII single‐photon response that include high amplification, local adaptation, and regenerative acceleration. J. Comp. Neurol. 521:3541‐3555, 2013. © 2013 Wiley Periodicals, Inc.