bluuebunny/crossref_metadata_2025 huggingface dataset:
Strong associations of short-chain perfluoroalkyl acids with serum albumin and investigation of binding mechanisms
Authors: Bischel Heather N , MacManus-Spencer Laura A , Zhang Chaojie , Luthy Richard G
Published: August 2011

Interactions of perfluoroalkyl acids (PFAAs) with tissue and serum proteins likely contribute to their tissue distribution and bioaccumulation patterns. Protein–water distribution coefficients (KPW) based on ligand associations with bovine serum albumin (BSA) as a model protein were recently proposed as biologically relevant parameters to describe the environmental behavior of PFAAs, yet empirical data on such protein binding behavior are limited. In the present study, associations of perfluoroalkyl carboxylates (PFCAs) with two to 12 carbons (C2–C12) and perfluoroalkyl sulfonates with four to eight carbons (C4, C6, and C8) with BSA are evaluated at low PFAA:albumin mole ratios and various solution conditions using equilibrium dialysis, nanoelectrospray ionization mass spectrometry, and fluorescence spectroscopy. Log KPW values for C4 to C12 PFAAs range from 3.3 to 4.3. Affinity for BSA increases with PFAA hydrophobicity but decreases from the C8 to C12 PFCAs, likely due to steric hindrances associated with longer and more rigid perfluoroalkyl chains. The C4-sulfonate exhibits increased affinity relative to the equivalent chain-length PFCA. Fluorescence titrations support evidence that an observed dependence of PFAA-BSA binding on pH is attributable to conformational changes in the protein. Association constants determined for perfluorobutanesulfonate and perfluoropentanoate with BSA are on the order of those for long-chain PFAAs (Ka∼106/M), suggesting that physiological implications of strong binding to albumin may be important for short-chain PFAAs. Environ. Toxicol. Chem. 2011;30:2423–2430. © 2011 SETAC
Multicultural social policy and community participation in health: new opportunities and challenges for indigenous people
Authors: Torri Maria Costanza
Published: August 2011

Community participation in local health has assumed a central role in the reforms of public healthcare, being increasingly associated with the issue of decentralization of the health system. The aim of this paper is to raise questions regarding the structural approaches to multicultural social policy in Chile and to analyze the results of its implementation. The article analyzes the case study of Makewe Hospital, one of the pioneering experiences of intercultural health initiative in Chile. The Makewe Hospital, which involves the indigenous community of the Mapuche, provides interesting insights to understand the dynamics of multicultural social policy and presents an example of a successful initiative that has succeeded in involving local communities in multicultural health policy. This case study discusses the effectiveness of grassroots participation in multicultural healthcare provision and presents the main strengths and challenges for the replicability of this experience in other settings. Copyright © 2011 John Wiley & Sons, Ltd.
Root‐zone temperature and nitrogen affect the yield and secondary metabolite concentration of fall‐ and spring‐grown, high‐density leaf lettuce
Authors: Bumgarner Natalie R , Scheerens Joseph C , Mullen Robert W , Bennett Mark A , Ling Peter P , Kleinhenz Matthew D
Published: August 2011

BACKGROUND: Understanding the effects of temperature and nitrogen levels on key variables, particularly under field conditions during cool seasons of temperate climates, is important. Here, we document the impact of root‐zone heating and nitrogen (N) fertility on the accumulation and composition of fall‐ and spring‐grown lettuce biomass. A novel, scalable field system was employed.

RESULTS: Direct‐seeded plots containing a uniform, semi‐solid, and nearly stable rooting medium were established outdoors in 2009 and 2010; each contained one of eight combinations of root‐zone heating (−/+) and N fertility (0, 72, 144, and 576 mg day−1). Root‐zone heating increased but withholding N decreased biomass accumulation in both years. Low N supplies were also associated with greater anthocyanin and total antioxidant power but lower N and phosphorus levels. Tissue chlorophyll a and vitamin C levels tracked root‐zone temperature and N fertility more closely in 2009 and 2010, respectively.

CONCLUSIONS: Experimentally imposed root‐zone temperature and N levels influenced the amount and properties of fall‐ and spring‐grown lettuce tissue. Ambient conditions, however, dictated which of these factors exerted the greatest effect on the variables measured. Collectively, the results point to the potential for gains in system sustainability and productivity, including with respect to supplying human nutritional units. Copyright © 2011 Society of Chemical Industry
Does neoadjuvant chemotherapy reveal disease precluding surgical treatment of initially resectable colorectal cancer liver metastases?
Authors: Reddy Srinevas K. , Tsung Allan , Marsh James Wallis , Geller David A.
Published: August 2011

Background

The objective of this study is to determine whether neoadjuvant chemotherapy reveals occult disease precluding surgical extirpation of initially resectable colorectal cancer liver metastases (CRCLM).

Methods

Demographics, clinicopathologic tumor characteristics, treatments, and post‐operative outcomes of patients aged 18–80 years, with one to four initially resectable CRCLM, and without concurrent extra‐hepatic (EHMD) or previous metastatic disease were reviewed.

Results

Two hundred and two patients evaluated from 2000 to 2010 met study criteria; 88 (43.6%) were given neoadjuvant chemotherapy. Patients treated with neoadjuvant chemotherapy were younger (median 58 years vs. 65 years, P = 0.0096), had shorter disease free interval from resection of primary tumor to CRCLM diagnosis (median 0 months vs. 12 months, P < 0.0001), and had more CRCLM (median 1 [1–3] vs. 1 [1–2], P = 0.0096) compared to untreated counterparts. There were no differences in rates of concurrent EHMD noted intra‐operatively and not on pre‐operative imaging (4.5% vs. 3.5%, P = 0.7290), greater intra‐operatively observed CRCLM compared to pre‐operative imaging (25.3% vs. 17.5%, P = 0.2449), hepatic resection and/or ablation (97.7% vs. 100.0%, P = 0.9853), or 6‐month disease recurrence after surgical treatment (25.6% vs. 14.9%, P = 0.0882). Only two (2.3%) patients treated with neoadjuvant chemotherapy had disease progression precluding surgical extirpation.

Conclusions

Neoadjuvant chemotherapy for initially resectable CRCLM does not reveal occult disease precluding surgical treatment. J. Surg. Oncol. 2012; 105:55–59. © 2011 Wiley Periodicals, Inc.
The prognostic value of grade of regression and oncocytic change in rectal adenocarcinoma treated with neo‐adjuvant chemoradiotherapy
Authors: Roy Paromita , Serra Stefano , Kennedy Erin , Chetty Runjan
Published: August 2011

Background

Pathological staging and regression grading may affect the clinical outcome in rectal carcinoma patients treated with neoadjuvant chemoradiation (NACRT). Oncocytic change (OC) has also been described in the residual tumor. This study assesses the correlation of degree of pathological response and OC with clinical outcome.

Methods

Seventy‐five cases of rectal adenocarcinoma undergoing NACRT followed by surgery were retrospectively analyzed for preoperative and post‐operative staging, degree of tumor response to NACRT using the Dworak Regression score (DR) and Tumor Regression Grading (TRG) systems, as well as the proportion of cells showing OC. These parameters were correlated with overall survival (OS) and disease‐free survival (DFS).

Results

Significant correlation was found between post‐operative T and N stage and OS (P = 0.005 and 0.002, respectively); and post‐operative and preoperative T stage with DFS (P = 0.002 and 0.02, respectively). Grouping patients by TRG scores (TRG1‐3 vs TRG4‐5) also proved to be a significant independent prognosticator for DFS (P < 0.001). The DR score groups and OC (<35% vs. >35%) were not statistically significant predictors of clinical outcome.

Conclusions

Post‐NACRT T and N staging and the TRG system are important prognostic indicators. The presence and extent of OC needs to be better understood and further investigated. J. Surg. Oncol. 2012; 105:130–134. © 2011 Wiley Periodicals, Inc.
Responsive Poly(acrylic acid) and Poly(N‐isopropylacrylamide) Monoliths by High Internal Phase Emulsion (HIPE) Templating
Authors: Kovačič Sebastijan , Jeřabek Karel , Krajnc Peter
Published: August 2011

High internal phase emulsions are used to prepare cross‐linked polystyrene/poly(acrylic acid) (PS/PAA) and polystyrene/poly(N‐isopropyl acrylamide) (PS/PNIPAM) monoliths with a polystyrene scaffold and acrylic domains inside the cavities of the scaffold. Acrylic acid or NIPAM are included in the aqueous phase of a high internal phase emulsion, while the oil phase includes styrene. Polymerisation of such high internal phase emulsions (HIPEs) yields macroporous polymers (polyHIPEs) with a scaffold composed of cross‐linked polystyrene and domains of cross‐linked poly(acrylic acid) or cross‐linked poly(NIPAM) positioned inside the cavities of the polystyrene skeleton. Monolithic discs are shaped from PS/PAA and PS/PNIPAM polyHIPEs in order to study the dependence of flow resistance through the discs in relation to pH or temperature changes. The amount of acrylic component in the aqueous phase and the degree of cross‐linking prove to be the most influential on the pressure drops of columns with monolithic discs. The temperature influences the resistance properties in the case of PS/PNIPAM material. Inverse size exclusion chromatography experiments confirm the pH dependent structure of the polymeric monoliths.

magnified image
Dual Aggregation Behavior of Porphyrin‐Cored Thiophene Dendrimers
Authors: Deng Suxiang , Advincula Rigoberto C.
Published: August 2011

Two porphyrin‐cored thiophene dendrimers T(3T)P and T(7T)P have been successfully synthesized and characterized by UV‐vis and fluorescence measurements. The self‐assembly of these two water‐insoluble free base porphyrins to form both intrinsic H‐ and J‐aggregates has been reported for the first time. This intrinsic behavior is in contrast to the use of surfactants, dyes, and metal ions to induce aggregation behavior on most porphyrin systems. This work emphasizes the importance of controlling the size, solvent, and extent of conjugation of polythiophene dendron groups in porphyrin systems. These materials may yet be applied to polythiophene or porphyrin blend system in energy conversion devices with the light‐harvesting properties of the polythiophene dendrons.

magnified image
Horseradish Peroxidase as a Catalyst for Atom Transfer Radical Polymerization
Authors: Sigg Severin J. , Seidi Farzad , Renggli Kasper , Silva Tilana B. , Kali Gergely , Bruns Nico
Published: August 2011

The hemoprotein horseradish peroxidase (HRP) catalyzes the polymerization of N‐isopropylacrylamide with an alkyl bromide initiator under conditions of activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) in the absence of any peroxide. This is a novel activity of HRP, which we propose to name ATRPase activity. Bromine‐terminated polymers with polydispersity indices (PDIs) as low as 1.44 are obtained. The polymerization follows first order kinetics, but the evolution of molecular weight and the PDI upon increasing conversion deviate from the results expected for an ATRP mechanism. Conversion, $\overline {M} _{{\rm n}} $ and PDI depend on the pH and on the concentration of the reducing agent, sodium ascorbate. HRP is stable during the polymerization and does not unfold or form conjugates.

magnified image
Entry in Emulsion Copolymerization: Can the Existing Models be Verified?
Authors: Daswani Pooja , van Herk Alex
Published: August 2011

Various models have been proposed in order to understand different physical and chemical events taking place during emulsion copolymerization. One of the important processes involved is the entry of radicals into particles, which is often described using the model of Maxwell and Morrison. For emulsion homopolymerization, experimental data partly support this model, while for emulsion copolymerization not many experimental data are available. Here, the different models that have been established over the past decades are reviewed with an emphasis on the propagational mechanisms involved during the entry of oligomeric radicals into latex particles in emulsion homopolymerization. An answer is given to the title question: “Can the existing models be verified?”.

magnified image
Residence Time Distribution Study of a Living/Controlled Radical Miniemulsion Polymerization System in a Continuous Tubular Reactor
Authors: Enright Thomas E. , Cunningham Michael F.
Published: August 2011

Residence time distribution (RTD) studies were done to determine the flow characteristics in a continuous tubular reactor. Pulse tracer experiments were done at different flow rates and temperatures, and a comparison was made between a homogeneous aqueous salt mixture versus a heterogeneous miniemulsion mixture. The heterogeneous system was studied under two different conditions, one with a monomer‐in‐water droplet dispersion and one with fully formed polymer particles dispersed in water. There were differences observed between all of the systems tested and none of them matched an ideal plug flow condition. The reactor contains stagnant zones of varying volume and tracer spreading was observed in all cases. The dispersion model was found to model the system quite well in most cases.

magnified image
Simplified quantification of labile proton concentration‐weighted chemical exchange rate (kws) with RF saturation time dependent ratiometric analysis (QUESTRA): Normalization of relaxation and RF irradiation spillover effects for improved quantitative chemical exchange saturation transfer (CEST) MRI
Authors: Sun Phillip Zhe
Published: August 2011

Chemical exchange saturation transfer MRI is an emerging imaging technique capable of detecting dilute proteins/peptides and microenvironmental properties, with promising in vivo applications. However, chemical exchange saturation transfer MRI contrast is complex, varying not only with the labile proton concentration and exchange rate, but also with experimental conditions such as field strength and radiofrequency (RF) irradiation scheme. Furthermore, the optimal RF irradiation power depends on the exchange rate, which must be estimated in order to optimize the chemical exchange saturation transfer MRI experiments. Although methods including numerical fitting with modified Bloch‐McConnell equations, quantification of exchange rate with RF saturation time and power (QUEST and QUESP), have been proposed to address this relationship, they require multiple‐parameter non‐linear fitting and accurate relaxation measurement. Our work extended the QUEST algorithm with ratiometric analysis (QUESTRA) that normalizes the magnetization transfer ratio at labile and reference frequencies, which effectively eliminates the confounding relaxation and RF spillover effects. Specifically, the QUESTRA contrast approaches its steady state mono‐exponentially at a rate determined by the reverse exchange rate (kws), with little dependence on bulk water T1, T2, RF power and chemical shift. The proposed algorithm was confirmed numerically, and validated experimentally using a tissue‐like phantom of serially titrated pH compartments. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
K‐space filter deconvolution and flip angle self‐calibration in 2D radial hyperpolarised 3He lung MRI
Authors: Marshall Helen , Ajraoui Salma , Deppe Martin H. , Parra‐Robles Juan , Wild Jim M.
Published: August 2011

In hyperpolarised 3He lung MRI with constant flip angles, the transverse magnetisation decays with each RF excitation imposing a k‐space filter on the acquired data. For radial data acquired in an angularly‐sequential order, this filter causes streaking, angular shading and loss of spatial resolution in the images. The main aim of this work was to reduce the effects of the RF depletion k‐space filter in radial acquisitions. Two approaches are presented; (i) retrospective deconvolution of the k‐space filter for sequentially‐acquired data and (ii) golden angle acquisition order. Radial trajectories sample the centre of k‐space with every projection, thereby self‐tracking signal decay. The inverse of the signal decay function was used to retrospectively deconvolve RF depolarisation k‐space filter effects and the method was demonstrated in 2D radial imaging in phantoms and human lungs. A golden angle radial acquisition was shown to effectively suppress artefacts caused by the RF depletion k‐space filter. In addition, the average flip angle per slice was calculated from the signal decay and the values were found to correspond with conventional flip angle maps, providing a means of flip angle self‐calibration. Copyright © 2011 John Wiley & Sons, Ltd.
The thin‐layer method in a cross‐anisotropic 3D space
Authors: de Oliveira Barbosa João Manuel , Kausel Eduardo
Published: August 2011

This article presents a generalization of the thin‐layer method to three dimensions, a tool that allows assessing layered media subjected to loads eliciting nonsymmetrical wave fields. It is based on a formulation that fully couples the three components of motion, and allows finding effective solutions to either stationary or moving loads of arbitrary shape that act on (or within) horizontally layered media. In particular, it is an ideal tool for finding analytical solutions to the so‐called 2.5D problem, which entails loads with arbitrary distribution in one horizontal coordinate direction together with a harmonic (sinusoidal) variation in the other. Inasmuch as the Green's functions for the latter case are found explicitly in the spatial domain without recourse to numerical integration, it allows using such functions — most likely in the context of the boundary element method — as fundamental solutions for problems of soil–structure interaction where the structure is invariant in one horizontal direction, such as a railroad track resting on an embankment. The method entails solving at each frequency of interest two uncoupled eigenvalue problems for generalized SH and SVP waves (i.e. horizontally and vertically polarized shear and pressure waves), after which the fundamental solutions are obtained in closed‐form at any desired point in space. Inasmuch as the proposed technique dispenses with at least one of the two inverse Fourier transforms into the spatial domain, in due time the methodology presented is likely to become the preferred tool for a wide class of problems. The technique is first benchmarked against the known solution for a point load and then applied to a rectangular and triangular load distribution. Copyright © 2011 John Wiley & Sons, Ltd.
Polyarc discrete element for efficiently simulating arbitrarily shaped 2D particles
Authors: Fu Pengcheng , Walton Otis R. , Harvey John T.
Published: August 2011

A new two‐dimensional discrete element type, termed the ‘polyarc’ element is presented in this paper. Compared to other discrete element types, the new element is capable of representing any two‐dimensional convex particle shape with arbitrary angularity and elongation using a small number of shape parameters. Contact resolution between polyarc elements, which is the most computation‐extensive task in DEM simulation only involves simple closed‐form solutions. Two undesirable contact scenarios common for polygon elements can be avoided by the polyarc element, so the contact resolution algorithm for polyarc elements is simpler than that for polygon elements. The extra flexibility in particle shape representation induces little or no additional computational cost. The key algorithmic aspects of the new element, including the particle shape representation scheme, the quick neighbor search algorithm, the contact resolution algorithm, and the contact law are presented. The recommended contact law for the polyarc model was formulated on the basis of an evaluation of various contact law schemes for polygon type discrete elements. The capability and efficiency of the new element type were demonstrated through an investigation of strength anisotropy of a virtual sand consisting of a random mix of angular and smooth elongated particles subjected to biaxial compression tests. Copyright © 2011 John Wiley & Sons, Ltd.
Boundary element formulation for plane problems in couple stress elasticity
Authors: Hadjesfandiari A. R. , Dargush G. F.
Published: August 2011

Couple‐stresses are introduced to account for the microstructure of a material within the framework of continuum mechanics. Linear isotropic versions of such materials possess a characteristic material length l that becomes increasingly important as problem dimensions shrink to that level (e.g., as the radius a of a critical hole reduces to a size comparable to l). Consequently, this size‐dependent elastic theory is essential to understand the behavior at micro‐ and nano‐scales and to bridge the atomistic and classical continuum theories. Here we develop an integral representation for two‐dimensional boundary value problems in the newly established fully determinate theory of isotropic couple stress elastic media. The resulting boundary‐only formulation involves displacements, rotations, force‐tractions and moment‐tractions as primary variables. Details on the corresponding numerical implementation within a boundary element method are then provided, with emphasis on kernel singularities and numerical quadrature. Afterwards the new formulation is applied to several computational examples to validate the approach and to explore the consequences of size‐dependent couple stress elasticity. Copyright © 2011 John Wiley & Sons, Ltd.
Multiscale prediction of mechanical behavior of ferrite–pearlite steel with numerical material testing
Authors: Watanabe I. , Setoyama D. , Nagasako N. , Iwata N. , Nakanishi K.
Published: August 2011

Multiscale mechanical behaviors of ferrite–pearlite steel were predicted using numerical material testing (NMT) based on the finite element method. The microstructure of ferrite–pearlite steel is regarded as a two‐component aggregate of ferrite crystal grains and pearlite colonies. In NMT, the macroscopic stress–strain curve and the deformation state of the microstructure were examined by means of a two‐scale finite element analysis method based on the framework of the mathematical homogenization theory. The microstructure of ferrite–pearlite steel was modeled with finite elements, and constitutive models for ferrite crystal grains and pearlite colonies were prepared to describe their anisotropic mechanical behavior at the microscale level. While the anisotropic linear elasticity and the single crystal plasticity based on representative characteristic length have been employed for the ferrite crystal grains, the constitutive model of a pearlite colony was newly developed in this study. For that reason, the constitutive behavior of the pearlite colony was investigated using NMT on a smaller scale than the scale of the ferrite–pearlite microstructure, with the microstructure of the pearlite colony modeled as a lamellar structure of ferrite and cementite phases with finite elements. On the basis of the numerical results, the anisotropic constitutive model of the pearlite colony was formulated based on the normal vector of the lamella. The components of the anisotropic elasticity were estimated with NMT based on the finite element method, where the elasticity of the cementite phase was numerically evaluated with a first‐principles calculation. Also, an anisotropic plastic constitutive model for the pearlite colony was formulated with two‐surface plasticity consisting of yield functions for the interlamellar shear mode and yielding of the overall lamellar structure. After addressing the microscopic modeling of ferrite–pearlite steel, NMT was performed with the finite element models of the ferrite–pearlite microstructure and with the microscopic constitutive models for each of the components. Finally, the results were compared with the corresponding experimental results on both the macroscopic response and the microscopic deformation state to ascertain the validity of the numerical modeling. Copyright © 2011 John Wiley & Sons, Ltd.
Dental Health of Free Blacks in New York State during the Mid‐19th Century
Authors: Nystrom K. C.
Published: August 2011

The current research will examine the frequency of carious teeth, periapical abscesses and ante‐mortem tooth loss in the Newburgh Colored Burial Ground (1830–1870), a free black cemetery in Newburgh, New York. The Newburgh material is compared with skeletal samples from the New York African Burial Ground, New York State almshouses, a free black cemetery from Philadelphia and middle‐class/upper‐class European cemeteries. Although previous research suggests that dental health became worse throughout the 19th century, there is no consistent pattern between the 17th‐century and 18th‐century skeletal sample of enslaved blacks from New York City and 19th‐century free blacks from Newburgh and Philadelphia. The frequency of dental caries does increase through time but the other indicators change little (equal or fewer ante‐mortem tooth loss) or suggest an improvement in dental health (fewer periapical abscesses) through time. Relative to contemporaneous populations, the individuals from Newburgh appear much more similar in terms of dental health to upper‐class and middle‐class European groups than to the other marginalised groups considered in this research. The impact of the economic, political and social changes that accompanied the Industrial Revolution and their potential impact on dental health are considered. Copyright © 2011 John Wiley & Sons, Ltd.
Mandibular Fracture and Dislocation in a Case Study from the Jewish Cemetery of Lucena (CÓRDOBA), in South Iberian Peninsula (8th–12th ad)
Authors: De Luca S. , Viciano J. , Irurita J. , López‐Lázaro S. , Cameriere R. , Botella D.
Published: August 2011

The skeletal remains of an adult female have been exhumed in an 11th century tomb in the mediaeval Jewish cemetery of Ronda Sur, in the city of Lucena (Córdoba, Spain). Examination of the skull and mandible revealed evidences of bilateral condylar fracture and dislocation. Lesions were observed macroscopically and radiology was used as a complementary method of scrutiny, especially in cases of unclear observation. Irregular morphology of the condyles and coronoid processes, shallow glenoid fossa, altered and abnormal joint surfaces anterior to the glenoid fossa, and reduced height of both ascending rami were observed. Ante‐mortem tooth loss, slight wear of occlusal surface and asymmetrical occlusal deposit of dental calculus were found. Radiologically, degenerative changes in the condyles and reparative bone in both coronoid processes have been identified. Dislocation of the condyles and lack of adequate treatment probably led to disruption of masticatory patterns and related structures, such as muscle attachments, articular disc and ligaments. Bilateral remodelled fracture and the altered appearance of the joint structures could probably mean that the individual survived the injury by several years. This type of fracture could be the consequence of direct blow to the mental or submental region that was transmitted in a direction that raised the mandible, causing the condylar head to collide directly with the mandibular fossa. Very few mandibular fractures in ancient skulls have been described in Spain, and this case is the first example found in a Spanish archaeological skeletal assemblage. Copyright © 2011 John Wiley & Sons, Ltd.
The alternative lengthening of telomeres pathway may operate in non‐neoplastic human cells
Authors: Slatter Tania L , Tan Xin , Yuen Yi Ching , Gunningham Sarah , Ma Sally SiYan , Daly Erin , Packer Stephen , Devenish Celia , Royds Janice A , Hung Noelyn A
Published: August 2011

The alternative lengthening of telomeres (ALT) mechanism represents an alternative to the enzyme telomerase in the maintenance of mammalian telomeres in 25–60% of sarcomas and a minority of carcinomas (about 5–15%). ALT‐positive cells are distinguished by long and heterogeneous telomere length distributions by terminal restriction fragment (TRF) Southern blotting. Another diagnostic marker of ALT is discrete nuclear co‐localized signals of telomeric DNA and the promyelocytic leukaemia protein (PML), referred to as ALT‐associated PML bodies (APBs). Recently, we detected smaller sized co‐localized PML and telomere DNA (APB‐like) bodies in endothelial cells adjacent to astrocytoma tumour cells in situ. In this study, we examined a wide variety of non‐neoplastic tissues, and report that co‐localized signals of PML and telomere DNA are present in endothelial, stromal, and some epithelial cells. Co‐localized signals of PML and telomere DNA showed an increased frequency in non‐neoplastic cells with DNA damage. These results suggest that a mechanism similar to that in ALT‐positive tumours also operates in non‐neoplastic cells, which may be activated by DNA damage. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Sphingosine‐1‐phosphate signalling induces the production of Lcn‐2 by macrophages to promote kidney regeneration
Authors: Sola Anna , Weigert Andreas , Jung Michaela , Vinuesa Eugenia , Brecht Kerstin , Weis Nicole , Brüne Bernhard , Borregaard Niels , Hotter Georgina
Published: August 2011

Inflammatory reactions are initiated to eliminate pathogens, but also to promote repair of damaged tissue after acute inflammation is terminated. In this regard, macrophages play a prominent role during induction as well as resolution of inflammation and injury in various organs including the kidney. The present study describes a mechanism for renal tissue regeneration after ischaemia/reperfusion injury. Following injury, apoptotic cell‐derived sphingosine‐1‐phosphate (S1P) or exogenously administered sphingosine analogue FTY720 activates macrophages to support the proliferation and healing of renal epithelium, once inflammatory conditions are terminated. Both suppression of inflammation and renal regeneration might require S1P receptor 3 (S1P3) signalling and downstream release of neutrophil gelatinase‐associated lipocalin (NGAL/Lcn‐2) from macrophages. Overall, our data point to a macrophage‐dependent S1P‐S1P3‐Lcn‐2 axis that might be beneficial for restoration of kidney function after an ischaemic insult. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Helichrysum monizii Lowe: Phenolic Composition and Antioxidant Potential
Authors: Gouveia Sandra , Castilho Paula C.
Published: August 2011

Introduction

In Madeira Archipelago there are four endemic Helichyrsum species and three of them are used in the traditional medicine. Helichrysum monizii is a rare endemism with very scarce information available concerning its uses in the local traditional medicine.

Objective

The aim of this work was to study for the first time Helichrysum monizii in terms of its antioxidant capacity and the identification of the phenolic compounds to which that activity is due.

Methodology

Three different methods of extraction were performed and total phenolic and flavonoid contents of extracts were correlated to radical scavenging and antioxidant capacity by DPPH, ABTS, FRAP and β‐carotene assays. An HPLC‐DAD‐ESI/MSn method was employed for the separation and identification of the phenolic and flavonoid components.

Results

The results revealed a high antioxidant potential mainly related to the phenolic profile of the plant. Polar components of methanol extracts of Helichrsyum monizii were detected by a high‐performance liquid chromatography/electrospray ionisation tandem mass spectrometry (HPLC‐DAD‐ESI/MSn) method. Thirty‐three compounds were identified and 19 of them were identified as quinic acid derivatives.

Conclusions

The high antioxidant potential Helichrysum monizii was for the first time established. Dicaffeoylquinic acids are the main responsible for that activity. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation, structure and properties of thermoplastic olefin nanocomposites containing functionalized carbon nanotubes
Authors: Li Chaoqun , Zhao Qinna , Deng Hua , Chen Chen , Wang Ke , Zhang Qin , Chen Feng , Fu Qiang
Published: August 2011

The morphology and properties of multiwalled carbon nanotube modified polypropylene (PP)/ethylene–octene copolymer blends were studied. Polypropylene chains are covalently grafted onto the surface of carbon nanotubes (CNTs) in order to improve their interaction with the polymer matrix. It is observed that functionalization of CNTs improves their dispersion and increases the interfacial bonding between CNTs and polymer matrix. The functionalized CNTs are selectively distributed in the continuous polypropylene phase. The size of the dispersed elastomer phase decreases after the addition of CNTs. Functionalized CNTs act as a nucleating agent and increase the crystallinity of the polypropylene. More importantly, an important increase in impact strength, stiffness and toughness can be achieved through introducing functionalized CNTs. Copyright © 2011 Society of Chemical Industry
Functionality of peripheral side chain for enhanced performance of conjugated polymer—F8BT as an example
Authors: Dong Wenyue , Xue Shanfeng , Lu Ping , Deng Jian , Zhao Donglin , Gu Cheng , Ma Yuguang
Published: August 2011

A series of F8BT‐based copolymers (PCFBTs) with functional peripheral side chains were designed and synthesized. The complementation of side chain with polymer backbone in electronic and optical properties was realized. Electron‐riched carbazole moieties on the peripheral side chains of fluorene unit significantly reduce the first oxidation potential and increase the highest occupied molecular orbital energy levels of PCFBTs. Increase of hole injection and transport ability was achieved in PCFBTs. Among them, PCFBT shows a maximum luminous efficiency of 0.7 cd/A and a turn‐on voltage of 3.0 V in the single‐layered device, which are better than F8BT without the carbazole moieties (0.1 cd/A, 3.8 V). The radios of fluorene and benzothiadiazole (BTz) unit in polymers were adjusted to balance the electron and hole transport, and PCFBT0.2 (BTz:fluorene = 2:8) exhibits 13 times higher maximum luminous efficiency (10.8 cd/A) than F8BT (0.8 cd/A) in a double‐layered device. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effect of water addition on the cure kinetics of an epoxy‐amine thermoset
Authors: Choi Sungwon , Janisse Andrew P. , Liu Changhua , Douglas Elliot P.
Published: August 2011

In this study, the effect of water addition on cure kinetics in an epoxy‐amine thermoset was investigated. Near FTIR spectra demonstrated that a small amount of water addition significantly accelerated the cure reaction in terms of epoxide conversion, with water acting as a catalyst for the reaction. Use of a modified mechanistic model allowed direct comparison of the effect of hydroxyl groups generated from water addition to those generated from the polymer chain. The comparison of those kinetic parameters shows that the two effects are very close, in which difference in the logarithmic value of the reaction constant is less than one order of magnitude over all the reaction conditions. The kinetic study also confirmed a strong negative substitution effect for this system. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Phase transformations in MgTbNd alloy
Authors: Smola Bohumil , Stulíková Ivana , Černá Jaroslava , Čížek Jakub , Vlach Martin
Published: August 2011

Precipitation in the MgTbNd alloy with ∼4 wt.%Tb and ∼2 wt.%Nd solution treated at 500 °C/4 h was studied by means of differential scanning calorimetry (DSC) with linear heating rates 1–20 K/min. Electrical resistivity measurements at 78 K, positron annihilation spectroscopy (PAS), and transmission electron microscopy (TEM) were performed on the specimens isochronally annealed in steps 20 K/20 min or 30 K/30 min. Microhardness HV0.1 annealing curves for various isochronal heating programs corresponding to linear heating rates 0.5–10 K/min revealed hardening caused by individual precipitation processes. The precipitation sequence includes successively DO19 clusters, DO19 particles, extremely small particles of the cbco phase, β1 phase with fcc structure, β phase of Mg5(Tb,Nd) type, and β phase of Mg41(Tb,Nd)5 type. All the particles except the last one have a plate‐shape oriented in the Mg matrix in a triangular arrangement. Activation energies of the individual precipitation processes were determined from calorimetric measurements. The results of the PAS and electrical measurements correspond well to the DSC results as well as to the hardening caused by the β1 phase particles.
Advances and applications in the FIREBALLab initio tight‐binding molecular‐dynamics formalism
Authors: Lewis James P. , Jelínek Pavel , Ortega José , Demkov Alexander A. , Trabada Daniel G. , Haycock Barry , Wang Hao , Adams Gary , Tomfohr John K. , Abad Enrique , Wang Hong , Drabold David A.
Published: August 2011

One of the outstanding advancements in electronic‐structure density‐functional methods is the Sankey–Niklewski (SN) approach [Sankey and Niklewski, Phys. Rev. B 40, 3979 (1989)]; a method for computing total energies and forces, within an ab initio tight‐binding formalism. Over the past two decades, several improvements to the method have been proposed and utilized to calculate materials ranging from biomolecules to semiconductors. In particular, the improved method (called FIREBALL) uses separable pseudopotentials and goes beyond the minimal sp3 basis set of the SN method, allowing for double numerical (DN) basis sets with the addition of polarization orbitals and d‐orbitals to the basis set. Herein, we report a review of the method, some improved theoretical developments, and some recent application to a variety of systems.
Antioxidant Properties of Selected Plant Extracts and Application in Packaging as Antioxidant Cellulose‐Based Films for Vegetable Oil
Authors: Phoopuritham Panchuti , Thongngam Masubon , Yoksan Rangrong , Suppakul Panuwat
Published: August 2011

Selected plant extracts including cinnamon, clove, ginger, green tea and thyme were investigated for their antioxidant activity by using both β‐carotene‐linoleate bleaching agar well diffusion and β‐carotene‐linoleate bleaching broth assays, and for radical scavenging activity against free radicals using a 2,2‐diphenyl‐1‐picrylhydrazyl assay. Undiluted plant extracts (except ginger oil) showed a yellow zone of β‐carotene ranging from 15.3 to 38.2 mm in diameter. At a concentration of 50 μL mL‐1, thyme yielded the highest antioxidant activity (260%), followed by ginger (254%), cinnamon (108%), clove (106%) and green tea (101%), respectively. Conversely, at a plant extract concentration of 0.39 μL mL‐1 solution in ethanol, green tea yielded the highest radical scavenging activity (94.3%), followed by clove (93.4%), cinnamon (91.1%), thyme (30.4%) and ginger (8.29%), respectively. The minimum oxidative bleaching inhibitory concentrations (MOBICs) of these plant extracts were determined using a β‐carotene‐linoleate bleaching broth dilution assay ranging from 0.195 to 50 μL mL‐1. The MOBICs of plant extracts in a range of 0.195–1.56 μL mL‐1 could reveal an ability to inhibit the oxidation of β‐carotene‐linoleate broth. Cellulose‐based film containing cinnamon, clove or green tea showed positive activity against β‐carotene‐linoleate oxidation and 2,2‐diphenyl‐1‐picrylhydrazyl radicals. Protective effects of plant extracts incorporated in cellulose‐based pouches in stabilizing soybean oil were tested by measuring their peroxide values and free fatty acid contents during accelerated storage. Green tea‐incorporated cellulose‐based pouches exhibited stronger antioxidant properties in soybean oil than do butylated hydroxyanisole‐incorporated cellulose‐based pouches. This study showed the potential use of plant extracts as antioxidants for food packaging application. Copyright © 2011 John Wiley & Sons, Ltd.
The TKE budget in the convective Martian planetary boundary layer
Authors: Martínez G. M. , Valero F. , Vázquez L.
Published: August 2011

The turbulent kinetic energy (TKE) budget has been obtained for the first time from ground‐based data on Mars, both for the unstable surface layer (SL) and for the convectively driven mixed layer (CML). Values for storage, buoyancy, shear, vertical turbulent transport, dissipation, and an imbalance term accounting for the rest of the TKE budget have been determined and weighted for significance.

These results have been derived from ground‐based measurements made by Viking Lander 1 (VL1) on Sol 28, Viking Lander 2 (VL2) on Sol 20, and Pathfinder (PF) on Sol 25, and through an adaptation to Mars of terrestrial similarity theory, which constitutes a new approach to the study of the TKE budget on Mars.

Shear is the main TKE generator in the unstable SL for VL1 Sol 28 and PF Sol 25. It is narrowly exceeded by dissipation, the main mechanism removing TKE. Both terms present values ∼10−1m2s−3. Buoyancy generates TKE, though it plays a minor role (∼10−2m2s−3). Vertical turbulent transport balances buoyancy, removing TKE from the SL by sending it upwards. The imbalance term represents 30% of the main mechanisms, while storage plays an insignificant role (∼10−5m2s−3). The SL TKE budget for VL2 Sol 20 presents a different behaviour instead, with the imbalance term becoming the main TKE generator, likely due to the anomalous atmospheric conditions existing during this Sol.

Buoyancy and dissipation play the major roles generating and removing TKE in the CML for the three Sols under study, respectively, both showing values around 5×10−3m2s−3. Vertical turbulent transport plays a minor role (∼10−4m2s−3), and so does the imbalance term, with values about 25% of buoyancy or dissipation. Finally, shear and storage terms are negligible, presenting values ∼10−6 and ∼10−5m2s−3, respectively. Copyright © 2011 Royal Meteorological Society
Application of an adaptive radiative transfer scheme in a mesoscale numerical weather prediction model
Authors: Schomburg A. , Venema V. , Ament F. , Simmer C.
Published: August 2011

The computational burden of radiative transfer parametrization is considerable, and hence operational atmospheric models use various sampling, coarsening and interpolation techniques to reduce this load; this, however, introduces new errors. An adaptive radiative transfer scheme takes advantage of the spatial and temporal correlations in the optical characteristics of the atmosphere to make the parametrization computationally more efficient. The adaptive scheme employed here generalizes the accurate radiation computations made in a fraction of the spatial and temporal space to the rest of the field. In this study, a previously developed scheme has been extended to atmospheric heating rates and implemented in the numerical weather prediction model COSMO. The performance of the adaptive scheme is compared with the performance of the currently operational COSMO‐DE radiation configuration, in which radiation computations are performed quarter‐hourly on 2 × 2 averaged atmospheric columns. The reference for both schemes is a set of frequent radiation computations for the full grid. We show that the adaptive scheme is able to reduce the sampling errors in the radiation surface fluxes by 15–25% and to conserve the spatial variability, in contrast to the operational scheme. Deviations in the heating‐rate profiles are reduced for larger averaging scales. Physical relationships between the radiative quantities and cloud water or rain rates are better captured. We demonstrate that these improvements also lead to improvements with respect to the dynamical development of the model simulation, showing a smaller divergence from the reference model run. Copyright © 2011 Royal Meteorological Society
EFFECTS OF PASSAGE BARRIERS ON DEMOGRAPHICS AND STABILITY PROPERTIES OF A VIRTUAL TROUT POPULATION
Authors: Harvey B. C. , Railsback S. F.
Published: August 2011

Habitat fragmentation is widely assumed to have negative effects on populations and communities, but some effects of fragmentation are subtle, difficult to measure and not always negative. For stream fish, barriers to upstream passage, such as waterfalls or culverts with perched outlets, are a common cause of fragmentation. We explored the effects of barriers on a virtual stream trout population occupying a network of reaches in the inSTREAM individual‐based trout population model. The model includes daily habitat selection by individual fish, with barriers represented by assuming trout cannot move upstream past a barrier and move downstream over a barrier only if habitat above it offers low potential fitness. In 78‐year simulations of a resident trout population occupying the stream network of a 25‐km2 catchment, we varied barrier density and observed effects on population stability properties and demographics. Increasing barrier density decreased subpopulation persistence in first‐order tributaries but not larger streams. Barriers at tributary mouths reduced the population's resistance to extreme flows, but additional barriers caused no further loss of resistance. Barriers reduced overall abundance and biomass at intermediate and high densities and caused a small but surprising increase in biomass at low density. In comparison with fish in the remainder of the network, fish in isolated first‐order tributaries had higher survival early in life, smaller sizes at age and reproduced as smaller, younger individuals. Fish that passed over barriers contributed relatively little to downstream populations but, had they not moved, would have increased persistence and abundance of the tributaries they moved from. Relationships such as these would be very difficult to elucidate without a model representing individual behaviour. Copyright © 2011 John Wiley & Sons, Ltd.
Atomic force microscopy of microwear traces on Mousterian tools from Myshtylagty Lagat (Weasel Cave), Russia
Authors: Faulks Nathan R. , Kimball Larry R. , Hidjrati Nazim , Coffey Tonya S.
Published: August 2011

Since durable technology emerged between 3.4 and 3.2 million years ago, stone tools served as a major material means that hominins used to survive. Determining how different lithic tools functioned is a principal question in human evolution. The main experimentally based approach to the functional study of lithic technology uses stereo and incident‐light microscopy, and is known as the Keeley Method. Although this method has demonstrated success in linking the morphology of microwear traces on flint tools to the function of the tool, there is no agreed upon model of how these microwear polishes form. At the same time, the characterization of these polishes has been a largely qualitative process. Herein, we use the atomic force microscope (AFM) to scan microwear traces on Middle Palaeolithic (Mousterian) tools from Weasel Cave, Russia to show quantitative data and small scale features of microwear polishes interpreted (using the Keeley Method) as due to contact with meat, fresh hide, dry hide, bone, wood, and hafting. These results follow those of to the previous AFM study on the experimental tools, namely that the meat and dry hide polishes are the least developed polishes with smaller changes in roughness and that the bone polish and wood polishes are more highly developed polishes and exhibit larger changes in roughness. SCANNING 33: 304–315, 2011. © 2011 Wiley Periodicals, Inc.