bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeting integrins and enhanced permeability and retention (EPR) effect for optical imaging of oral cancer
Authors: Keereweer Stijn , Mol Isabel M. , Kerrebijn Jeroen D.F. , Van Driel Pieter B.A.A. , Xie Bangwen , Baatenburg de Jong Robert J. , Vahrmeijer Alexander L. , Löwik Clemens W.G.M.
Published: September 2011

Background and Objectives

Near‐infrared (NIR) fluorescence optical imaging is a promising technique to assess the tumor margins during cancer surgery. This technique requires targeting by specific fluorescence agents to differentiate tumor from normal surrounding tissue. We assessed the feasibility of cancer detection using NIR fluorescence agents that target either αvβ3 integrins or the enhanced permeability and retention (EPR) effect in an orthotopic mouse model of oral cancer.

Methods

Binding of the integrin‐targeted agent to tumor cells was assessed in vitro. Oral cancer was induced in 6 BALB/c nu/nu mice by submucosal inoculation of human OSC19‐luc cells into the tongue. Tumor growth was followed with bioluminescence imaging. A combination of agents targeting integrins or EPR effect was injected followed by fluorescence imaging in vivo and ex vivo after resection of the tongues.

Results

Oral cancer was clearly demarcated in vitro; in vivo; and on histological analysis with sufficient tumor‐to‐background ratios of the contrast agents.

Conclusion

This study demonstrates the feasibility of optical imaging of oral squamous cell carcinoma based on targeting of αvβ3 integrins and the EPR effect. Once these NIR fluorescence agents become available for clinical testing, optical image‐guided surgery could reduce residual disease after oral cancer surgery. J. Surg. Oncol. 2012; 105:714–718. © 2011 Wiley Periodicals, Inc.
Effects of fire and grazing on grasshopper sparrow nest survival
Authors: Hovick Torre J. , Miller James R. , Dinsmore Stephen J. , Engle David M. , Debinski Diane M. , Fuhlendorf Samuel D.
Published: September 2011

Patch‐burn grazing is a management framework designed to promote heterogeneity in grasslands, creating more diverse grassland structure to accommodate the habitat requirements of many grassland species, particularly grassland birds. Published studies on the effects of patch‐burn grazing on passerines have been conducted on relatively large (430–980 ha pastures), contiguous grasslands, and only 1 of these studies has investigated the reproductive success of grassland birds. We assessed the effects of the patch‐burn grazing and a more traditional treatment on the nesting ecology of grasshopper sparrows (Ammodramus savannarum) in small (<37 ha pastures) grasslands located in southern Iowa from May to August of 2008 and 2009. The study pastures were grazed from May to September and prescribed burns were conducted in the spring. We investigated the effects of treatments on clutch size and modeled grasshopper sparrow nest survival as a function of multiple biological and ecological factors. We found no difference in clutch size between treatments; however, we did find a reduction in clutch size for nests that were parasitized by brown‐headed cowbirds (Molothrus ater). Constant daily survival rates were greater in patch‐burn grazed pastures than in grazed‐and‐burned pastures (patch‐burn grazed rate ${\bar {x}} = 0.930$ and grazed‐and‐burned rate ${\bar {x}} = 0.907$). Competitive survival models included year, stage of nest, nest age, and cool‐season grass (csg) abundance within 5 m of the nest. Overall, csg abundance had the greatest effect on survival and had a negative influence. Although survival rates were highest in patch‐burn grazed pastures, multiple factors influenced grasshopper sparrow survival. Nest survival rates for both treatments were relatively low, and variables other than treatment were more instrumental in predicting grasshopper sparrow survival. We recommend decreasing overall vegetation cover if increasing nesting habitat for grasshopper sparrows is a management goal. In addition, we recommend further investigation of heterogeneity management in fragmented landscapes to better understand how it affects biodiversity in relatively small management units that typify grassland habitats in the Midwest. © 2011 The Wildlife Society.
Nanocarriers for Cytoplasmic Delivery: Cellular Uptake and Intracellular Fate of Chitosan and Hyaluronic Acid‐Coated Chitosan Nanoparticles in a Phagocytic Cell Model
Authors: Zaki Noha M. , Nasti Alessandro , Tirelli Nicola
Published: September 2011

The cellular uptake of hyaluronic‐acid‐coated, negatively charged chitosan/triphosphate nanoparticles and that of uncoated, positively charged ones is investigated by studying cellular localization, uptake kinetics and mechanism of internalization in J774.2 macrophages, using non‐phagocytic L929 fibroblasts as a control for uncoated nanoparticles. Both kinds of nanoparticles undergo endosomal escape and adopt a similar clathrin‐based endocytic mechanism. The surface decoration with HA profoundly influences the kinetics of cellular uptake, with an at least two orders of magnitude slower kinetics, but also the nature of the binding on the cellular surface.

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Shifting From Ziegler–Natta to Philips‐Type Catalyst? A Simple and Safe Access to Reduced Titanium Systems for Ethylene Polymerization
Authors: Popoff Nicolas , Espinas Jeff , Gouré Eric , Boyron Olivier , Le Roux Erwan , Basset Jean‐Marie , Gauvin Régis M. , De Mallmann Aimery , Taoufik Mostafa
Published: September 2011

Silica‐supported titanium(IV) chloride is readily reduced by Mashima and co‐workers' reagent (1‐methyl‐3,6‐bis(trimethylsilyl)‐1,4‐cyclohexadiene) to afford materials active in ethylene polymerisation without need of aluminum alkyl cocatalyst.
Hierarchical Organization of Cartilage Proteoglycans
Authors: Horkay Ferenc , Basser Peter J. , Hecht Anne‐Marie , Geissler Erik
Published: September 2011

The hierarchical organization of cartilage proteoglycans is investigated on different length and time scales using osmotic pressure measurements, small angle neutron scattering (SANS), small angle X‐ray scattering (SAXS), static and dynamic light scattering and neutron spin echo techniques. Osmotic pressure measurements reveal association of aggrecan bottlebrushes into microgel‐like assemblies. SAXS, SANS and light scattering results indicate weak interpenetration between neighboring aggrecan molecules. As opposed to DNA and many synthetic polyelectrolytes, which display great sensitivity to ion valence, aggrecan exhibits exceptional insensitivity to calcium ions in the physiological ion concentration range and beyond. This property allows aggrecan to play a role of ion reservoir that can mediate calcium metabolism in cartilage and bone.
Studies of the So‐Called Jamming Phenomenon in Filled Rubbers Using Dynamical‐Mechanical Experiments
Authors: Richter Sven , Kreyenschulte Hermann , Saphiannikova Marina , Götze Thomas , Heinrich Gert
Published: September 2011

In the past, several models have been proposed to describe the so‐called jamming on filled rubbers. We carefully repeated such experiments on carbon black filled EPDM systems and found that the interpretation given in the literature is not transferable to our systems. Therefore, one has to be very careful in using these universal criteria to describe such dynamic‐mechanical transitions on filled polymer systems.

Furthermore, we present an improved multi‐stage agglomeration model to describe the flocculation process in filled elastomer systems.
Construction of Crosslink‐System‐Materials Utilizing Designed Network‐Polymer‐Precursor Modules
Authors: Matsumoto Akira
Published: September 2011

For a long time, we have been concerned with the elucidation of network formation mechanism of free‐radical crosslinking (co)polymerization of multivinyl monomers. We have pursued two extreme network structures formation such as ideal and nanogel‐like NPP formation. During the course of these investigations, we recognized that a network polymer may be reconsidered as a crosslink‐system‐material (CSM) or a giant system consisting of network polymer precursor (NPP) modules. The network polymer is not a giant molecule as a smallest unit of matter which could behave as one molecule. According to this definition, our subject may be changed from the molecular design of network polymer to the molecular design of NPP based on the free‐radical crosslinking multivinyl polymerization mechanism. Then, we could construct a variety of CSMs utilizing designed NPP modules. A variety of CSM constructions are exemplified.
Visual misperceptions and hallucinations in Parkinson's disease: Dysfunction of attentional control networks?
Authors: Shine James M. , Halliday Glenda M. , Naismith Sharon L. , Lewis Simon J.G.
Published: September 2011

Visual misperceptions and hallucinations are a major cause of distress in patients with Parkinson's disease (PD), particularly in the advanced stages of the condition. Recent work has provided a framework for understanding the pathogenesis of these symptoms, implicating impairments from the retina to the integration of external information with preformed internal images. In this article, we propose a novel hypothesis that attempts to explain the presence of visual misperceptions and hallucinations in PD through the aberrant coordination of complimentary yet competing neural networks. We propose that hallucinations in PD reflect the relative inability to recruit activation in the dorsal attention network in the presence of an ambiguous percept, leading to overreliance on default mode network processing and salience arising from the ventral attention network. This inability is proposed to stem from improper function across cortical and subcortical structures secondary to the presence of Lewy body pathology. This hypothesis may be empirically tested by the use of targeted cognitive paradigms. In turn, this may assist our understanding of the pathophysiological mechanisms and cognitive processes contributing to visual misperceptions and hallucinations and ultimately may inform more effective treatment strategies for this troubling symptom. © 2011 Movement Disorder Society
Association of SNCA with Parkinson: Replication in the Harvard NeuroDiscovery Center Biomarker Study
Authors: Ding Hongliu , Sarokhan Alison K. , Roderick Sarah S. , Bakshi Rachit , Maher Nancy E. , Ashourian Paymon , Kan Caroline G. , Chang Sunny , Santarlasci Andrea , Swords Kyleen E. , Ravina Bernard M. , Hayes Michael T. , Sohur U. Shivraj , Wills Anne‐Marie , Flaherty Alice W. , Unni Vivek K. , Hung Albert Y. , Selkoe Dennis J. , Schwarzschild Michael A. , Schlossmacher Michael G. , Sudarsky Lewis R. , Growdon John H. , Ivinson Adrian J. , Hyman Bradley T. , Scherzer Clemens R.
Published: September 2011

Background:

Mutations in the α‐synuclein gene (SNCA) cause autosomal dominant forms of Parkinson's disease, but the substantial risk conferred by this locus to the common sporadic disease has only recently emerged from genome‐wide association studies.

Methods:

We genotyped a prioritized noncoding variant in SNCA intron 4 in 344 patients with Parkinson's disease and 275 controls from the longitudinal Harvard NeuroDiscovery Center Biomarker Study.

Results:

The common minor allele of rs2736990 was associated with elevated disease susceptibility (odds ratio, 1.40; P = .0032).

Conclusions:

This result increases confidence in the notion that in many clinically well‐characterized patients, genetic variation in SNCA contributes to “sporadic” disease. © 2011 Movement Disorder Society
Spatial location and strength of BOLD activation in high‐spatial‐resolution fMRI of the motor cortex: a comparison of spin echo and gradient echo fMRI at 7 T
Authors: Harmer J. , Sanchez‐Panchuelo R. M. , Bowtell R. , Francis S. T.
Published: September 2011

The increased blood oxygenation level‐dependent contrast‐to‐noise ratio at ultrahigh field (7 T) has been exploited in a comparison of the spatial location and strength of activation in high‐resolution (1.5 mm isotropic) gradient echo (GE) and spin echo (SE), echo planar imaging data acquired during the execution of a simple motor task in five subjects. SE data were acquired at six echo times from 30 to 55 ms. Excellent fat suppression was achieved in the SE echo planar images using slice‐selective gradient reversal. Threshold‐free cluster enhancement was used to define regions of interest (ROIs) containing voxels showing significant stimulus‐locked signal changes from the GE and average SE data. These were used to compare the signal changes and spatial locations of activated regions in SE and GE data. T2 and T2* values were measured, with means of 48.3 ± 1.1 ms and 36.5 ± 3.4 ms in the SE ROI. In addition, we identified a dark band in SE images of the motor cortex corresponding to a region in which T2 and T2* were significantly lower than in the surrounding grey matter. The fractional SE signal change in the ROI was found to vary linearly as a function of TE, with a slope that was dependent on the particular ROI assessed: the mean ΔR2 value was found to be 0.85 ± 0.11 s–1 for the SE ROI and −0.37 ± 0.05 s–1 for the GE ROI. The fractional signal change relative to the shortest TE revealed that the largest signal change occurred at a TE of 45 ms outside of the dark band. At this TE, the ratio of the fractional signal change in GE and SE data was found to be 0.48 ± 0.05. Phase maps produced from high‐resolution GE images spanning the right motor cortex were used to identify veins. The GE ROI was found to contain 18% more voxels overlying the venous mask than the SE ROI. Copyright © 2011 John Wiley & Sons, Ltd.
Phase contrast MRI is an early marker of micrometastatic breast cancer development in the rat brain
Authors: Budde Matthew D. , Gold Eric , Jordan E. Kay , Smith‐Brown Melissa , Frank Joseph A.
Published: September 2011

The early growth of micrometastatic breast cancer in the brain often occurs through vessel co‐option and is independent of angiogenesis. Remodeling of the existing vasculature is an important step in the evolution of co‐opting micrometastases into angiogenesis‐dependent solid tumor masses. The purpose of this study was to determine whether phase contrast MRI, an intrinsic source of contrast exquisitely sensitive to the magnetic susceptibility properties of deoxygenated hemoglobin, could detect vascular changes occurring independent of angiogenesis in a rat model of breast cancer metastases to the brain. Twelve nude rats were administered 106 MDA‐MB‐231BRL ‘brain‐seeking’ breast cancer cells through intracardiac injection. Serial, multiparametric MRI of the brain was performed weekly until metastatic disease was detected. The results demonstrated that images of the signal phase (area under the receiver operating characteristic curve, 0.97) were more sensitive than T2* gradient echo magnitude images (area under the receiver operating characteristic curve, 0.73) to metastatic brain lesions. The difference between the two techniques was probably the result of the confounding effects of edema on the magnitude of the signal. A region of interest analysis revealed that vascular abnormalities detected with phase contrast MRI preceded tumor permeability measured with contrast‐enhanced MRI by 1–2 weeks. Tumor size was correlated with permeability (R2 = 0.23, p < 0.01), but phase contrast was independent of tumor size (R2 = 0.03). Histopathologic analysis demonstrated that capillary endothelial cells co‐opted by tumor cells were significantly enlarged, but less dense, relative to the normal brain vasculature. Although co‐opted vessels were vascular endothelial growth factor‐negative, vessels within larger tumor masses were vascular endothelial growth factor‐positive. In conclusion, phase contrast MRI is believed to be sensitive to vascular remodeling in co‐opting brain tumor metastases independent of sprouting angiogenesis, and may therefore aid in preclinical studies of angiogenic‐independent tumors or in the monitoring of continued tumor growth following anti‐angiogenic therapy. Published 2011. This article is a US Government work and is in the public domain in the USA.
Noninvasive imaging identifies new roles for cyclooxygenase‐2 in choline and lipid metabolism of human breast cancer cells
Authors: Shah Tariq , Stasinopoulos Ioannis , Wildes Flonne , Kakkad Samata , Artemov Dmitri , Bhujwalla Zaver M.
Published: September 2011

The expression of cyclooxygenase‐2 (COX‐2) is observed in approximately 40% of breast cancers. A major product of the COX‐2‐catalyzed reaction, prostaglandin E2, is an inflammatory mediator that participates in several biological processes, and influences invasion, vascularization and metastasis. Using noninvasive MRI and MRS, we determined the effect of COX‐2 downregulation on the metabolism and invasion of intact poorly differentiated MDA‐MB‐231 human breast cancer cells stably expressing COX‐2 short hairpin RNA. Dynamic tracking of invasion, extracellular matrix degradation and metabolism was performed with an MRI‐ and MRS‐compatible cell perfusion assay under controlled conditions of pH, temperature and oxygenation over the course of 48 h. COX‐2‐silenced cells exhibited a significant decrease in invasion relative to parental cells that was consistent with the reduced expression of invasion‐associated matrix metalloproteinase genes and an increased level of the tissue inhibitor of metalloproteinase‐1. We identified, for the first time, a role for COX‐2 in mediating changes in choline phospholipid metabolism, and established that choline kinase expression is partly dependent on COX‐2 function. COX‐2 silencing resulted in a significant decrease in phosphocholine and total choline that was detected by MRS. In addition, a significant increase in lipids, as well as lipid droplet formation, was observed. COX‐2 silencing transformed parental cell metabolite patterns to those characteristic of less aggressive cancer cells. These new functional roles of COX‐2 may identify new biomarkers and new targets for use in combination with COX‐2 targeting to prevent invasion and metastasis. Copyright © 2011 John Wiley & Sons, Ltd.
Semantic context dissemination and service matchmaking in future network management
Authors: Famaey Jeroen , Latré Steven , Strassner John , Turck Filip De
Published: September 2011

The ever‐increasing size, complexity and heterogeneity of telecommunications networks necessitate the introduction of autonomic elements that assist providers in managing and configuring the network's resources. To tackle this increased complexity, it is expected that many specialized autonomic elements will take part in the management process. It becomes necessary for them to collaborate and communicate in order to achieve high‐level, human‐specified, management goals. Therefore, the need for a scalable mechanism to facilitate the interactions between autonomic elements has arisen. This article presents a communications bus, augmented with semantics through the use of ontologies and semantic reasoning, which governs the communication and collaboration between autonomic elements. It supports filtering of context based on meaning. Additionally, it facilitates matchmaking of autonomic element goals with management services using semantic definitions of their inputs, outputs, preconditions and effects. Furthermore, the delay introduced by semantic reasoning was evaluated through an implemented prototype and was shown to be limited to only a few milliseconds. Copyright © 2011 John Wiley & Sons, Ltd.
Developing planned giving at the Salvation Army Southern Territory
Authors: Sargeant Adrian , Hudson Jane
Published: September 2011

The Salvation Army operates internationally and is an evangelical part of the universal church, they provided help to over 30 million individuals in 2008. Their main focus is to build community, provide fellowship, rebuild lives, and provide comfort and support to those in need. They also provide disaster relief, drug and alcohol rehabilitation, and activities for the elderly, among many other social services. The international headquarters, the administration centre, is based in London. The Salvation Army USA, based in Virginia, has a national commander and national chief secretary who work to coordinate the national efforts. There are 4 geographical territories, south, east, west and central and each territory is a separately registered nonprofit entity. The southern territory is further divided into 9 divisions and has historically been very successful at planned giving fundraising. Planned giving success had been attributed to the territories personal approach. However, with the noticeable changes in the attitudes of seniors the planned giving has significantly declined in 2008/2009. Seniors, who had been considered the most suitable donor prospects had developed a sense of fear and distrust of the government and the banking system. They were resisting personal meetings with planned giving staff that had been so successful for the Salvation Army. As a consequence the planned giving strategy had to be adapted. Copyright © 2011 John Wiley & Sons, Ltd.
Using General Estimating Equations to Analyze Oral Health in the Moche Valley of Perú
Authors: Gagnon C. M. , Wiesen C.
Published: September 2011

This study introduces a new method for analyzing oral health indicators and thus reconstructing diet. To this end, we examined the dental remains of 173 individuals recovered from the site of Cerro Oreja in the Moche Valley of Perú, who lived during the Salinar (400–1 BC) or Gallinazo (AD 1–200) phases. The infectious and degenerative conditions analyzed include: dental caries, dental wear, dental abscess, antemortem tooth loss and dental calculus, all of which have been used to track dietary and thus subsistence‐related economic and sociopolitical changes. Data were analyzed using generalized estimating equations, an extension of generalized linear models. Significant changes in the frequency of occurrence of most dental conditions suggest that during the period of study, there was an increase in the consumption of agricultural products. However, these changes in oral health did not equally affect females and males. By the end of the Gallinazo phase, significant sex differences developed, with females more often affected by dental caries and males displaying greater mean molar wear scores. Copyright © 2011 John Wiley & Sons, Ltd.
COMPLEMENTARY ROLES? NGO–GOVERNMENT RELATIONS FOR COMMUNITY‐BASED SANITATION IN SOUTH ASIA
Authors: Sansom Kevin
Published: September 2011

Non‐governmental organisations (NGOs) and local governments differ in their ways of working and are subjected to very different conditioning factors. However, some NGOs engaged in community‐based sanitation are increasingly collaborating effectively with the local governments in South Asia. NGOs considered in this article have taken advantage of a more conducive environment to develop some well‐designed community‐based sanitation programmes in low‐income areas, in conjunction with the local government. Some NGOs have also participated in the development of government policies related to sanitation that have enabled the replication of their approaches. In making the transition from distrust between NGOs and local governments to working towards common ends, NGOs have demonstrated their comparative advantages and focused on developing productive relationships with both the local government and the communities in which they work. Copyright © 2011 John Wiley & Sons, Ltd.
FACTORS AFFECTING STATE–NON‐GOVERNMENTAL ORGANISATION RELATIONS IN SERVICE PROVISION: KEY THEMES FROM THE LITERATURE
Authors: Mcloughlin Claire
Published: September 2011

Collaboration between the state and the non‐governmental organisations (NGOs) in the provision of basic services is increasingly advocated in developing countries, yet there has been relatively little empirical research into the factors affecting the dynamics of these relationships. Much of the literature characterises state–NGO collaboration as fraught with inherent tensions, failing to live up to policy expectations and having negative implications for the non‐state sector's autonomy and identity. However, these effects are likely to be contingent on a range of structural ‘conditioning’ factors, including the history and institutional context of the relationship, the nature of the organisations themselves and the way the relationship is formally and informally organised. Recent research also recognises that actors can deploy a range of strategies to determine their room for manoeuvre and influence. The effects of the relationship on the actors' autonomy and identity and the balance of power that emerges between them may not therefore be straightforward, suggesting a need for more systematic research in this regard. Copyright © 2011 John Wiley & Sons, Ltd.
NEGOTIATING COLLABORATION IN PAKISTAN: EXPERTISE, NETWORKS AND COMMUNITY EMBEDDEDNESS
Authors: Bano Masooda
Published: September 2011

Despite growing emphasis within development policy on forging partnerships for development, very few development programmes designed to promote collaborative arrangements between state agencies and non‐governmental organisations (NGOs) to ensure the efficient service delivery of basic services to the poor succeed. Examining three cases of state–NGO collaboration in Pakistan, this article identified two NGO‐related factors as critical in helping create demand for their services within state agencies: (i) technical expertise and (ii) strong social and political networks. This article showed that attempts at collaboration are more likely to succeed if NGOs offer technically sound solutions to ensure efficient service delivery and have strong political and professional networks within the relevant state agencies to promote these solutions. Community‐embeddedness of the NGO can further help turn instances of collaboration into long‐term partnerships. Copyright © 2011 John Wiley & Sons, Ltd.
ANALYSING COLLABORATION BETWEEN NON‐GOVERNMENTAL SERVICE PROVIDERS AND GOVERNMENTS
Authors: Batley Richard , Rose Pauline
Published: September 2011

This article introduces a special issue on relations between governments and non‐government organisations (NGOs) that collaborate in improving public service provision in Bangladesh, India and Pakistan. NGOs are the focus because, although they are far from being the main non‐state service provider, they are the sector most likely to enter into collaboration with governments. However, such collaboration is often thought to lead to the loss of NGO autonomy and capacity for independent public action. This article analyses the factors that have led to the growth of NGO service provision and to the call for their partnership with the government. It then describes the theoretical approach and the research framework on which the special issue is based. The approach considers the institutional and organisational constraints to which NGOs subject themselves by entering into relations with governments and also their capacity for ‘strategic choice’ in the exercise of influence. Lastly, the article summarises the contributions to this special issue and relates them to the wider literature. Copyright © 2011 John Wiley & Sons, Ltd.
Ultrasonic characterization of phase morphology of high density polyethylene/polyamide 6 blend melts
Authors: Wang Shan , Lin Congmei , Sun Huimin , Chen Fan , Li Jiang , Guo Shaoyun
Published: September 2011

The high density polyethylene (HDPE) and polyamide 6 (PA6) blend melts with a droplet‐matrix microstructure were investigated using ultrasonic diagnosis system. The blend composition, as well as the particle size of the dispersed PA6 phase controlled by adding various amounts of the reactive compatibilizer HDPE grafted with maleic anhydride (HDPE‐g‐MAH), was, respectively, correlated with the ultrasonic velocity and attenuation. The results showed that ultrasonic velocity was insensitive to the particle size but varied linearly with the blend composition. However, the decrease of ultrasonic attenuation with the increasing content of HDPE‐g‐MAH suggested that the attenuation depended greatly on the particle size. Further investigations revealed that there was a good linear relationship between the excess attenuation and the size of the dispersed phase. Our results present that ultrasonic technique may be served as a promising technique for exploring phase morphology of polymer blends during processing. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Flammability of layered silicate epoxy nanocomposites combined with low‐melting inorganic ceepree glass
Authors: Wu Guang Mei , Schartel Bernhard , Kleemeier Malte , Hartwig Andreas
Published: September 2011

Tetraphenylphosphonium modified layered silicate epoxy nanocomposite (EP/TPPMMT) combined with low‐melting silicate glass, Ceepree (CP) is investigated by thermal analysis, flammability tests and cone calorimeter at different heat fluxes. Adding CP and TPPMMT does not change the pyrolysis apart from increasing inorganic residue. The total heat evolved (THE) is changed insignificantly, as neither relevant additional carbonaceous charring nor flame inhibition occurs. However, flame retardancy is clearly observed due to an inorganic‐carbonaceous surface protection layer. The peak heat released rate (PHRR) is reduced by around 32–42% when 5 wt% TPPMMT is added, and 51–63% when 10 wt% CP is added. PHRR reduction less than expected is observed when both additives are combined. The reduction is greater than that achieved by using TPPMMT but less than when only CP is used. The morphology of fire residue is investigated by scanning electron microscope on different length scales and turns out to be the key to understanding the efficiency of flame retardancy. The fire residue of EP/CP shows a layered structure, whereas separated columns limit the barrier properties for EP/5%TPPMMT on the micrometer scale. Columns dominating the fire residue structure of EP/5%TPPMMT/10%CP deteriorate the fire retardancy, whereas a more integral structure at the top of the residue causes the improvement over EP/5%TPPMMT. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Solid‐state dye‐sensitized and bulk heterojunction solar cells using TiO2 and ZnO nanostructures: recent progress and new concepts at the borderline
Authors: Bouclé Johann , Ackermann Jörg
Published: September 2011

In the field of photovoltaic energy conversion, hybrid inorganic/organic devices represent promising alternatives to standard photovoltaic systems in terms of exploiting the specific features of both organic semiconductors and inorganic nanomaterials. Two main categories of hybrid solar cells coexist today, both of which make much use of metal oxide nanostructures based on titanium dioxide (TiO2) and zinc oxide (ZnO) as electron transporters. These metal oxides are cheap to synthesise, are non‐toxic, are biocompatible and have suitable charge transport properties, all these features being necessary to demonstrate highly efficient solar cells at low cost. Historically, the first hybrid approach developed was the dye‐sensitized solar cell (DSSC) concept based on a nanostructured porous metal oxide electrode sensitized by a molecular dye. In particular, solid‐state hybrid DSSCs, which reduce the complexity of cell assembly, demonstrate very promising performance today. The second hybrid approach exploits the bulk heterojunction (BHJ) concept, where conjugated polymer/metal oxide interfaces are used to generate photocurrent. In this context, we review the recent progress and new concepts in the field of hybrid solid‐state DSSC and BHJ solar cells based on TiO2 and ZnO nanostructures, incorporating dyes and conjugated polymers. We point out the specificities in common hybrid device structures and give an overview on new concepts, which couple and exploit the main advantages of both DSSC and BHJ approaches. In particular, we show that there is a trend of convergence between both DSSC and BHJ approaches into mixed concepts at the borderline which may allow in the near future the development of hybrid devices for competitive photovoltaic energy conversion. Copyright © 2011 Society of Chemical Industry
A systematic investigation on the aromaticity and kinetic stability of fullerene C40 isomers
Authors: Kerim Ablikim
Published: September 2011

The aromatic character of fullerene C40 isomers was examined by the topological resonance energy and the percentage topological resonance energy models. It was found that they all are highly aromatized at the polyvalent anionic states. The nucleus‐independent chemical shifts at the cage center and the 2(N + 1)2 rule cannot be used as an indicator of the aromatic stabilization for C40 isomers and their molecular ions. In addition, we utilized the bond resonance energy model to estimate the kinetic stability of C40 isomers and their molecular ions. The results reveal that the kinetic stability of C40 isomers can be greatly enhanced at their polyvalent anionic states. Both the aromaticity and kinetic stability are closely related to the local structure and the cyclic motion of π electrons. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of helical poly(phenylacetylene)s bearing cinchona alkaloid pendants and their application to asymmetric organocatalysis
Authors: Miyake Garret M. , Iida Hiroki , Hu Hai‐Yu , Tang Zhenglin , Chen Eugene Y.‐X. , Yashima Eiji
Published: September 2011

Four novel dynamic helical poly(phenylacetylene)s bearing cinchona alkaloids as pendant groups were synthesized starting from the commercially available cinchona alkaloids, cinchonidine, cinchonine, quinine, and quinidine, by the polymerization of the corresponding phenylacetylene monomers with a rhodium catalyst. These polymers exhibited an induced circular dichroism (ICD) in the UV–visible region of the polymer backbones in solution, resulting from the preferred‐handed helical conformation induced by the optically active cinchona alkaloid pendants. In response to the solvent used, their Cotton effect patterns and intensities were significantly changed accompanied by the changes in their absorption spectra probably due to the changes in their helical conformations, such as the inversion of the helical sense or helical pitch of the polymers. When these helical polymers were used as polymeric organocatalysts for the asymmetric conjugated addition and Henry reactions, the optically active products with a modest enantiomeric excess were obtained whose enantioselectivities were comparable to those obtained with the corresponding cinchona alkaloid‐bound monomers as the catalysts. However, we observed a unique enhancement of the enantioselectivity and a reversal of the stereoselectivity for some helical polymers, suggesting the important role of the helical chirality during the asymmetric organocatalysis. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Crosslinked PDMS elastomers and coatings from the thermal curing of vinyl‐functionalized PDMS and a diazide aliphatic crosslinker
Authors: Damiron Denis , Okhay Nidhal , Akhrass Samer Al , Cassagnau Philippe , Drockenmuller Eric
Published: September 2011

The crosslinking of poly(dimethylsiloxane) elastomers and coatings by the thermal curing of poly(dimethylsiloxane‐co‐methylvinylsiloxane) and 1,12‐diazido‐dodecane was studied. This crosslinking pathway relies on the cycloaddition of azides and alkenes as well as the thermal generation of nitrene transient radicals, which react with alkenes, yielding respectively 1,2,3‐triazoline and aziridine crosslinking knots. The influence of temperature and the ratio of azide and vinyl functionalities has been investigated by rheological, swelling, and insoluble fraction measurements for materials crosslinked in bulk and by comparison of the thickness before and after extraction of the soluble materials by soxhlet extraction for the crosslinked coatings. The preparation of highly crosslinked PDMS‐based elastomers and coatings has been demonstrated, even if the fraction of elastically effective crosslinks in bulk remained below 160 mol/m3. Advantageously, this system does not require additional initiator or catalyst, is not sensitive to moisture or oxygen, and can be extended to a wide range of unsaturated polymers as well as different organic or inorganic solid substrates. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Plasma Surface Activation and TiN Coating of a TPV Substrate for Biomedical Applications
Authors: Lima Patricia , Pedrosa Paulo , Machado Ana Vera , Fonseca Carlos , Vaz Filipe
Published: September 2011

A thermoplastic vulcanizate (TPV) substrate was coated with a thin conductive film of titanium nitride (TiN), by dc reactive sputtering, aiming to develop polymer‐based electrodes for bio‐signal acquisition, namely for electroencephalographic (EEG) and electrocardiographic (ECG) applications. After the preparation process, TPVs were characterized in terms of their mechanical and surface properties. A detailed experimental protocol was followed in order to improve the adhesion of the film, consisting of a three‐stage plasma treatment in an argon atmosphere. The electrochemical properties of the coated samples were studied in synthetic sweat solutions by open circuit potential (OCP) measurements and electrochemical impedance spectroscopy (EIS). The results showed that the surface plasma treated TPV with a 60% EPDM and 40% PP composition coated with a nanometric TiN film exhibited good mechanical properties and electrochemical behavior, according to the main requirements of an electrode to be used in common EEG and ECG exams.

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Characterization of a Low‐pressure Inductively Coupled Plasma Discharge Sustained in Ar/O2/N2 Ternary Mixtures and Evaluation of its Effect on Erosion of Biological Samples
Authors: Kylián Ondřej , Denis Benjamin , Stapelmann Katharina , Ruiz Ana , Rauscher Hubert , Rossi Francois
Published: September 2011

Detailed characterization of a low‐pressure inductively coupled plasma discharge sustained in an Ar/O2/N2 ternary mixture is performed in this study. The main attention is devoted to the evaluation of the dependence of parameters important for treatment of biological samples (emission of UV radiation, plasma density, energy of charged particles, O atoms density, and substrate heating) on the working gas mixture composition. Subsequently, the capability of plasma sustained in ternary gas mixture to effectively etch biological contaminants is tested on examples of bacterial spores and poly‐L‐histidine.

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HBr Plasma Treatment Versus VUV Light Treatment to Improve 193 nm Photoresist Pattern Linewidth Roughness
Authors: Pargon Erwine , Azarnouche Laurent , Fouchier Marc , Menguelti Kevin , Tiron Raluca , Sourd Claire , Joubert Olivier
Published: September 2011

We have studied the impact of HBr plasma treatment and the role of the VUV light emitted by this plasma on the chemical modifications and resulting roughness of both blanket and patterned photoresists. The experimental results show that both treatments lead to similar resist bulk chemical modifications that result in a decrease of the resist glass transition temperature (Tg). This drop in Tg allows polymer chain rearrangement that favors surface roughness smoothening. The smoothening effect is mainly attributed to main chain scission induced by plasma VUV light. For increased VUV light exposure time, the crosslinking mechanism dominates over main chain scission and limits surface roughness smoothening. In the case of the HBr plasma treatment, the synergy between Bromine radicals and VUV light leads to the formation of dense graphitized layers on top and sidewalls surfaces of the resist pattern. The presence of a dense layer on the HBr cured resist sidewalls prevents from resist pattern reflowing but on the counter side leads to increased surface roughness and linewidth roughness compared to VUV light treatment.

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Prescribing antiemetics for patients with Parkinson's
Authors: Spencer Rachel , Serumaga Brian
Published: September 2011

In this series we present a number of prescribing safety indicators developed as part of an RCGP project.1 The evidence base behind each of the indicators is given along with information to illustrate their clinical significance. We provide a ‘real‐life’ audit based on the indicator to show how practices could begin to analyse their own prescribing data. Copyright © 2011 Wiley Interface Ltd
Resonance Raman spectroscopy of graphite and graphene
Authors: Zólyomi V. , Koltai J. , Kürti J.
Published: September 2011

We review the key aspects of Raman spectroscopy of graphite and graphene, focusing on the double resonant Raman modes such as the D, D* (also known as G' or 2D), and D' bands. We discuss the practical significance of Raman spectroscopy for the study of single‐ and multi‐layer graphene.
Analgesic and antiinflammatory activities of taxoids from Taxus wallichiana Zucc.
Authors: Qayum Mughal , Nisar Muhammad , Shah Muhammad Raza , Adhikari Achyut , Kaleem Waqar Ahmad , Khan Inamullah , Khan Nematullah , Gul Farah , Khan Ihsan Ali , Zia‐ul‐Haq M. , Khan Abad
Published: September 2011

A study was conducted to identify constituents that might be responsible for analgesic and antiinflammatory conditions. Tasumatrol B, 1,13‐diacetyl‐10‐deacetylbaccatin III (10‐DAD) and 4‐deacetylbaccatin III (4‐DAB) were isolated from the bark extract of Taxus wallichiana Zucc. All the compounds were assessed for analgesic and antiinflammatory activities using an acetic acid‐induced writhing model, a hot‐plate test, a carrageenan‐induced paw oedema model, a cotton‐pellet oedema model and in vitro lipoxygenase inhibitory assay. All the compounds, especially tasumatrol B, revealed significant analgesic activity in comparison to a saline group based on an acetic acid‐induced model. Similarly all of the test compounds, particularly tasumatrol B, showed significant antiinflammatory activity. However, all the compounds failed to exhibit any considerable activity in of the hot‐plate test and the in vitro lipoxygenase inhibitory assay. This study has highlighted the potential of tasumatrol B to be further explored as a new lead compound for the management of pain and inflammation, one that has been discovered by scientific validation of the traditional medicinal use of T. wallichiana Zucc. Copyright © 2011 John Wiley & Sons, Ltd.
Neuroprotective Effect of Rhizoma Atractylodis Macrocephalae Against Excitotoxicity‐induced Apoptosis in Cultured Cerebral Cortical Neurons
Authors: Gao Qun , Ji Zhi‐Hong , Yang Yang , Cheng Rui , Yu Xin‐Yu
Published: September 2011

Excitotoxicity has been implicated in neurological disorders. This study investigated the neuroprotective effect of the extract from Rhizoma Atractylodis macrocephalae on excitotoxicity‐induced neuronal apoptosis in primary cultured cerebral cortical neurons. Excitotoxicity was induced by exposure of cortical neurons to glutamate. Neuronal apoptosis and the protective effect of Rhizoma Atractylodis macrocephalae extract were examined by multi‐indices including cell viability assay, morphological features, DNA fragmentation and flow cytometric analysis. After exposure of cultured neurons to glutamate for 24 h, the neurons exhibited marked apoptotic‐like death. Co‐treatment of the neurons with glutamate and Rhizoma Atractylodis macrocephalae extract significantly elevated the cell viability, and reduced the number of apoptotic cells. These results demonstrate that Rhizoma Atractylodis macrocephalae is an effective neuroprotective agent against glutamate‐induced excitotoxicity and may have therapeutic potential in excitotoxicity‐mediated diseases. Copyright © 2011 John Wiley & Sons, Ltd.
Extruded Blends of Chitosan and Ethylene Copolymers for Antimicrobial Packaging
Authors: Massouda Debora Flanagan , Visioli Donna , Green Daniel A. , Joerger Rolf Dieter
Published: September 2011

Chitosan was melt‐processed with an ethylene methyl acrylate copolymer ionomer and with an ethylene vinyl acetate copolymer to create antimicrobial extruded films. The key to obtaining a successful antimicrobial blend was the use of solid chitosonium acetate that remained after evaporation of water from the chitosan solution. When solid free‐flowing powders of chitosonium acetate were formed by spray drying chitosan solutions, blended in an extruder (at 2.5% and 4% chitosan) with Elvax® 3175 ethylene vinyl acetate copolymer, and extruded through a film die onto a chill roll to form films, the films exhibited antimicrobial activity against Escherichia coli 25922, Salmonella enterica serovar Enteritidis NalR, and Listeria monocytogenes Scott A. The log10 reductions in CFU/ml after 24 h in a shake‐flask test were near 2 for films containing 4% chitosan. This melt‐blending/extrusion approach is expected to open applications for chitosan‐based antimicrobial packages and articles that were impossible or impractical with chitosan coatings. Copyright © 2011 John Wiley & Sons, Ltd.
Liquid chromatography/isotope ratio mass spectrometry measurement of δ13C of amino acids in plant proteins
Authors: Lynch Anthony H. , McCullagh James S. O. , Hedges Robert E. M.
Published: September 2011

In archaeological studies, the isotopic enrichment values of carbon and nitrogen in bone collagen give a degree of information on dietary composition. The isotopic enrichments of individual amino acids from bone collagen and dietary protein have the potential to provide more precise information about the components of diet. A limited amount of work has been done on this, although the reliability of these studies is potentially limited by fractionation arising through hydrolysis of whole plant tissue (where reaction between amino acids and carbohydrates may occur) and, for certain amino acids, the use of derivatives (particularly trifluoroacetyl derivatives) for gas chromatography/isotope ratio mass spectrometry (GC/IRMS) analysis. The present study takes the approach of extracting the protein components of plant tissues before hydrolysis and using liquid chromatography/isotope ratio mass spectrometry (LC/IRMS), which does not require derivatisation, for measurement of the isotopic enrichment of the amino acids. The protocol developed offers a methodology for consistent measurement of the δ13C values of amino acids, allowing isotopic differences between the individual amino acids from different plant tissues to be identified. In particular, there are highly significant differences between leaf and seed protein amino acids (leaf minus grain) in the cases of threonine (−4.1‰), aspartic acid (+3.5‰) and serine (−3.2‰). In addition to its intended application in archaeology, the technique will be of value in the fields of plant sciences, nutrition and environmental food‐web studies. Copyright © 2011 John Wiley & Sons, Ltd.
Considerations for quantification of lipids in nerve tissue using matrix‐assisted laser desorption/ionization mass spectrometric imaging
Authors: Landgraf Rachelle R. , Garrett Timothy J. , Prieto Conaway Maria C. , Calcutt Nigel A. , Stacpoole Peter W. , Yost Richard A.
Published: September 2011

Matrix‐assisted laser desorption/ionization (MALDI) mass spectrometric imaging is a technique that provides the ability to identify and characterize endogenous and exogenous compounds spatially within tissue with relatively little sample preparation. While it is a proven methodology for qualitative analysis, little has been reported for its utility in quantitative measurements. In the current work, inherent challenges in MALDI quantification are addressed. Signal response is monitored over successive analyses of a single tissue section to minimize error due to variability in the laser, matrix application, and sample inhomogeneity. Methods for the application of an internal standard to tissue sections are evaluated and used to quantify endogenous lipids in nerve tissue. A precision of 5% or less standard error was achieved, illustrating that MALDI imaging offers a reliable means of in situ quantification for microgram‐sized samples and requires minimal sample preparation. Copyright © 2011 John Wiley & Sons, Ltd.