bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology and mosaics of melanopsin‐expressing retinal ganglion cell types in mice
Authors: Berson David M. , Castrucci Ana Maria , Provencio Ignacio
Published: April 2010

Melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells (ipRGCs). Melanopsin immunoreactivity reveals two dendritic plexuses within the inner plexiform layer (IPL) and morphologically heterogeneous retinal ganglion cells. Using enhanced immunohistochemistry, we provide a fuller description of murine cell types expressing melanopsin, their contribution to the plexuses of melanopsin dendrites, and mosaics formed by each type. M1 cells, corresponding to the originally described ganglion‐cell photoreceptors, occupy the ganglion cell or inner nuclear layers. Their large, sparsely branched arbors (mean diameter 275 μm) monostratify at the outer limit of the OFF sublayer. M2 cells also have large, monostratified dendritic arbors (mean diameter 310 μm), but ramify in the inner third of the IPL, within the ON sublayer. There are ≈900 M1 cells and 800 M2 cells per retina; each type comprises roughly 1–2% of all ganglion cells. The cell bodies of M1 cells are slightly smaller than those of M2 cells (mean diameters: 13 μm for M1, 15 μm for M2). Dendritic field overlap is extensive within each type (coverage factors ≈3.8 for M1 and 2.5 for M2 cells). Rare bistratified cells deploy terminal dendrites within both melanopsin‐immunoreactive plexuses. Because these are too sparsely distributed to permit complete retinal tiling, they lack a key feature of true ganglion cell types and may be anomalous hybrids of the M1 and M2 types. Finally, we observed weak melanopsin immunoreactivity in other ganglion cells, mostly with large somata, that may constitute one or more additional types of melanopsin‐expressing cells. J. Comp. Neurol. 518:2405–2422, 2010. © 2010 Wiley‐Liss, Inc.
A coupling system for connecting switch mode inverters to magnetic loops
Authors: Theodoridis Michael P. , Mollov Stefan V.
Published: April 2010

This paper presents the analysis and design of a coupling system that allows magnetic loops to be connected efficiently to switch mode (SM) inverters. The coupling method involved has been traditionally used with linear amplifiers and transmission lines. The objective of this work is to develop a design procedure that is suitable for SM inverters. A detailed analysis is carried out on this coupling method and a design procedure is presented with an aim to optimize the operation of the inverter. The design procedure was used to build a 13.56 MHz prototype, the measurements from which they align very well with the theoretical predictions. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis and design of a two‐transformer active‐clamping forward converter with parallel‐connected current doubler rectifiers
Authors: Lo Yu‐Kang , Lin Chung‐Yi , Lin Jing‐Yuan , Chiu Huang‐Jen
Published: April 2010

A new two‐transformer active‐clamping forward converter with parallel‐connected current doubler rectifiers (CDRs) is proposed in this paper. The presented DC–DC converter is mainly composed of two active‐clamping forward converters with secondary CDRs. Only two switches are required and each one is the auxiliary switch for the other. The circuit complexity and cost are thus reduced. The leakage inductance of the transformer or an additional resonant inductance is employed to achieve zero‐voltage‐switching (ZVS) during the dead times. Two CDRs at the secondary side are connected in parallel to reduce the current stresses of the secondary windings and the ripple current at the output side. Accordingly, the smaller output chokes and capacitors decrease the converter volume and increase the power density. Detailed analysis and design of the presented two‐transformer active‐clamping forward converter are described. Experimental results are recorded for a prototype converter with a DC input voltage of 130−−180V, an output voltage of 5 V and an output current of 40 A, operating at a switching frequency of 100 kHz. Copyright © 2010 John Wiley & Sons, Ltd.
Improving Networks‐on‐Chip performability: A topology‐based approach
Authors: Elmiligi Haytham , Morgan Ahmed A. , El‐Kharashi M. Watheq , Gebali Fayez
Published: April 2010

The performability metric is commonly used in Networks‐on‐Chip (NoC)‐based systems to represent their abilities to successfully complete specific tasks in finite time intervals. In this paper, we present a novel topology‐based performability model for NoC‐based systems. The model is used to evaluate the performability of NoC‐based systems at early design phases. A comparative study of nine commonly used network architectures is performed using the proposed model. The purpose of the study is to explore the impact of the network topology on the performability of NoC‐based systems. Using the output from this study, a new methodology is proposed to improve the performability of a given application at early design phases. In this methodology, a joint consideration of five design parameters (network topology, target application traffic distribution, mapping of processing elements, noise power, and voltage swing) is carried out. Using the proposed methodology, designers can select the optimal topology for a given application that maximizes system performability. The effectiveness of the proposed methodology in determining the optimal topology is verified by experimental work and validated through a case study of a video application. Copyright © 2010 John Wiley & Sons, Ltd.
On the input common‐mode voltage range of CMOS bulk‐driven input stages
Authors: Carrillo Juan M. , Torelli Guido , Domínguez Miguel A. , Duque‐Carrillo J. Francisco
Published: April 2010

In this paper the response of a bulk‐driven MOS Metal‐Oxide‐Semiconductor input stage over the input common‐mode voltage range is discussed and experimentally evaluated. In particular, the behavior of the effective input transconductance and the input current is studied for different gate bias voltages of the input transistors. A comparison between simulated and measured results, in standard 0.35‐µm CMOS Complementary Metal‐Oxide‐Semiconductor technology, demonstrates that the model of the MOS transistors is not sufficiently accurate for devices operating under forward bias conditions of their source‐bulkpnjunction. Therefore, the fabrication and the experimental evaluation of any solution based on this approach are highly recommended. A technique to automatically control the gate bias voltage of a bulk‐driven differential pair is proposed to optimize the design tradeoff between the effective input transconductance and the input current. The proposed input stage was integrated as a standalone block and was also included in a 1.5‐V second‐order operational transconductance amplifier (OTA)‐Clowpass filter. Experimental results validate the effectiveness of the approach. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐switch flyback PWM DC–DC converter in discontinuous‐conduction mode
Authors: Murthy‐Bellur Dakshina , Kazimierczuk Marian K.
Published: April 2010

The two‐switch flyback DC–DC converter is an extended version of the conventional single‐switch flyback converter. An additional switch and two clamping diodes serve as a simple, but an effective way to limit the switch overvoltages, which occur in the conventional single‐switch flyback converter due to the ringing of the resonant circuit formed by the transformer leakage inductance and the transistor output capacitance. The clamping diodes in the two‐switch flyback topology clamp the maximum voltage across each switch equal to the DC input voltage. This paper presents a detailed analysis and design procedure of the diode‐clamped two‐switch flyback converter operated in discontinuous‐conduction mode (DCM). A comparison of power losses of the two‐switch and the single‐switch flyback converters is given. The two‐switch flyback converter was bread‐boarded to validate the theoretical analysis. Experimental results from a 20‐V/30‐W, 100‐kHz laboratory prototype verified that the maximum switch voltage is limited to the DC input voltage. Copyright © 2010 John Wiley & Sons, Ltd.
A new hyperchaotic Lorenz‐type system: Generation, analysis, and implementation
Authors: Li Yuxia , Liu Xuezhen , Chen Guanrong , Liao Xiaoxin
Published: April 2010

A new four‐dimensional continuous‐time autonomous hyperchaotic Lorenz‐type system is introduced and analyzed. This hyperchaotic system is not only visualized by computer simulation but also verified with bifurcation analysis and realized with an electronic circuit. Moreover, explicit formulae for estimating the ultimate bound and positive invariant set of the system are derived by constructing a family of generalized Lyapunov functions. The findings and results of this paper have good potential in control and synchronization of hyperchaos and their engineering applications. Copyright © 2010 John Wiley & Sons, Ltd.
A flexible current‐mode classifier circuit and its applications
Authors: Yıldız Merih , Minaei Shahram , Göknar İzzet Cem
Published: April 2010

In this paper a new CMOS classifier circuit is presented, simulated, and compared with other recently introduced circuits. The proposed CMOS circuit operates in current‐mode and can classify several types of data. The architecture is designed using two threshold circuits and a subtraction circuit. Among many possible applications of the classifier circuit, template‐based pattern classification, namely template matching and character recognition with corruption, and in another direction its use as a quantizer are given. Using 0.35‐ µm AMS technology parameters, SPICE simulations as well as hard realization results for the classifier and application circuits are included; detailed Monte Carlo analyses to assess parameter mismatch effects are also performed. Copyright © 2010 John Wiley & Sons, Ltd.
Asynchronous cellular logic network as a co‐processor for a general‐purpose massively parallel array
Authors: Lopich Alexey , Dudek Piotr
Published: April 2010

This paper demonstrates an implementation of an asynchronous cellular processor array that facilitates binary trigger‐wave propagations, extensively used in various image‐processing algorithms. The circuit operates in a continuous‐time mode, achieving high operational performance and low‐power consumption. An integrated circuit with proof‐of‐concept array of 24×60 cells has been fabricated in a 0.35µm three‐metal CMOS process and tested. Occupying only 16×8µm2the binary wave‐propagation cell is designed to be used as a co‐processor in general‐purpose processor‐per‐pixel arrays intended for focal‐plane image processing. The results of global operations such as object reconstruction and hole filling are presented. Copyright © 2010 John Wiley & Sons, Ltd.
All‐pass filters using DDCC‐ and MOSFET‐based electronic resistor
Authors: Metin Bilgin , Pal Kirat , Cicekoglu Oguzhan
Published: April 2010

The main motivation in this paper is to draw attention to the tunability and input‐signal amplitude limitations when a nonlinear device is used as a resistor. For this purpose, two first‐order all‐pass filters are proposed using differential difference current conveyor (DDCC), a capacitor and a resistor without element‐matching restriction. These all‐pass filter circuits can be made electronically tunable with electronic resistors. Tunability and input‐signal amplitude limitations of the proposed circuits due to the operational restrictions of the electronic resistors are examined. PSPICE simulations confirm the validity and the practical utility of the proposed circuits. Copyright © 2010 John Wiley & Sons, Ltd.
Steady‐state analysis of a novel ZVT interleaved boost converter
Authors: Genc Naci , Iskender Ires
Published: April 2010

In this paper, a novel soft‐switched interleaved boost converter composed of two‐cell boost conversion units and an auxiliary circuit is proposed and investigated. The proposed auxiliary circuit is implemented using only one auxiliary switch and a minimum number of passive components without an effective increase in the cost and the complexity of the converter. The main advantage of this auxiliary circuit is that it not only provides zero‐voltage‐transition (ZVT) for the main switches but also provides soft switching for the auxiliary switch and diodes. Though all semiconductor devices operate under soft switching, they do not have any additional voltage and current stresses. The proposed converter operates successfully in soft‐switching operation mode for a wide range of input voltage level and the load. In addition, it has advantages such as fewer structure complications, lower cost and ease of control. Since the two‐cell interleaved boost units are identical, operational analysis and design for the converter module become quite simple. In this study, the detailed steady‐state theoretical analysis of the proposed converter is presented, which is verified exactly by simulation and experiments carried out on a prototype of a 120 W and 50 kHz/cell interleaved boost converter. The practical results confirm the results obtained from theoretical analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Unsymmetrically Substituted Butenynyl‐Iron(II) Complexes
Authors: Field Leslie D. , Magill Alison M. , Pike Stuart R. , Turnbull Anthony J. , Dalgarno Scott J. , Turner Peter , Willis Anthony C.
Published: April 2010

The preparation and characterisation of iron(II) complexes bearing unsymmetrically 1,4‐disubstituted η3‐butenynyl ligands, cis‐[Fe(C(C≡CR)=C(H)R′)(dmpe)2][PF6] (e.g. R = tBu, R′ = Ph 2e; R = Ph, R′ = tBu 2e′) are reported. The complexes were obtained as a mixture by protonation and rearrangement of the bis(acetylido)iron(II) complex trans‐Fe(CCPh)(CCtBu)(dmpe)2. The complexes 2e and 2e′ were separated by crystallisation and were both characterised crystallographically. In addition, a number of complexes with symmetrically 1,4‐disubstituted butenynyl ligands cis‐[Fe(C(C≡CR)=C(H)R)(dmpe)2][PF6] (R = p‐C6H4‐OMe 2a; p‐C6H4‐Me 2b. C6H3‐3,5‐(CF3)2 2c; 1‐adamantyl 2d) were synthesised by protonation and rearrangement of the corresponding bis(acetylido)iron(II) complexes.
Cysteine‐Based Mannoside Glycoclusters: Synthetic Routes and Antiadhesive Properties
Authors: Schierholt Alexander , Hartmann Mirja , Schwekendiek Kirsten , Lindhorst Thisbe K.
Published: April 2010

Clustermannosides of different valency were synthesised based on cysteine. By employing the orthogonally protected amino acid as scaffold molecule, a variety of structurally varied products can be obtained according to different synthetic routes. Testing of the prepared glycoclusters as inhibitors of type 1 fimbriae mediated bacterial adhesion is reported, giving hints about the influence of sugar valency, sugar scaffolding, and the nature of the glycosidic aglycon in this testing system.
1q12 chromosome translocations form aberrant heterochromatic foci associated with changes in nuclear architecture and gene expression in B cell lymphoma
Authors: Fournier Alexandra , McLeer‐Florin Anne , Lefebvre Christine , Duley Samuel , Barki Leila , Ribeyron Juliana , Alboukadel Kassambara , Hamaidia Sieme , Granjon Aurélie , Gressin Rémy , Lajmanovich Alicia , Bonnefoix Thierry , Chauvelier Stéphanie , Debernardi Alexandra , Rousseaux Sophie , de Fraipont Florence , Figeac Martin , Kerckaert Jean‐Pierre , De Vos John , Usson Yves , Delaval Katia , Grichine Alexei , Vourc'h Claire , Khochbin Saadi , Feil Robert , Leroux Dominique , Callanan Mary B.
Published: April 2010

Epigenetic perturbations are increasingly described in cancer cells where they are thought to contribute to deregulated gene expression and genome instability. Here, we report the first evidence that a distinct category of chromosomal translocations observed in human tumours—those targeting 1q12 satellite DNA—can directly mediate such perturbations by promoting the formation of aberrant heterochromatic foci (aHCF). By detailed investigations of a 1q12 translocation to chromosome 2p, in a case of human B cell lymphoma, aberrant aHCF were shown to be localized to the nuclear periphery and to arise as a consequence of long range ‘pairing’ between the translocated 1q12 and chromosome 2 centromeric regions. Remarkably, adjacent 2p sequences showed increased levels of repressive histone modifications, including H4K20me3 and H3K9me3, and were bound by HP1. aHCF were associated to aberrant spatial localization and deregulated expression of a novel 2p gene (GMCL1) that was found to have prognostic impact in diffuse large B cell lymphoma. Thus constitutive heterochromatin rearrangements can contribute to tumourigenesis by perturbing gene expression via long range epigenetic mechanisms.
Rapid targeted mutational analysis of human tumours: a clinical platform to guide personalized cancer medicine
Authors: Dias‐Santagata Dora , Akhavanfard Sara , David Serena S. , Vernovsky Kathy , Kuhlmann Georgiana , Boisvert Susan L. , Stubbs Hannah , McDermott Ultan , Settleman Jeffrey , Kwak Eunice L. , Clark Jeffrey W. , Isakoff Steven J. , Sequist Lecia V. , Engelman Jeffrey A. , Lynch Thomas J. , Haber Daniel A. , Louis David N. , Ellisen Leif W. , Borger Darrell R. , Iafrate A. John
Published: April 2010

Targeted cancer therapy requires the rapid and accurate identification of genetic abnormalities predictive of therapeutic response. We sought to develop a high‐throughput genotyping platform that would allow prospective patient selection to the best available therapies, and that could readily and inexpensively be adopted by most clinical laboratories. We developed a highly sensitive multiplexed clinical assay that performs very well with nucleic acid derived from formalin fixation and paraffin embedding (FFPE) tissue, and tests for 120 previously described mutations in 13 cancer genes. Genetic profiling of 250 primary tumours was consistent with the documented oncogene mutational spectrum and identified rare events in some cancer types. The assay is currently being used for clinical testing of tumour samples and contributing to cancer patient management. This work therefore establishes a platform for real‐time targeted genotyping that can be widely adopted. We expect that efforts like this one will play an increasingly important role in cancer management.

See accompanying article: 10.1002/emmm.201000071
Soybean peroxidase‐catalyzed treatment and removal of BPA and bisphenol derivatives from aqueous solutions
Authors: Watanabe Chisato , Kashiwada Ayumi , Matsuda Kiyomi , Yamada Kazunori
Published: April 2010

The systematic studies were carried out to determine the optimum process parameters, such as the hydrogen peroxide (H2O2) concentration, concentration and molar mass of poly(ethylene glycol) (PEG) as an additive, pH value, temperature, and enzyme dose for treatment of bisphenol A (BPA) with soybean peroxidase (SBP). The SBP‐catalyzed treatment of BPA was effectively enhanced by adding PEG in the presence of H2O2. BPA was completely treated by SBP of 0.50 U/cm3 and water‐insoluble oligomers were generated. The optimum conditions for SBP‐catalyzed treatment of BPA at 0.3 mM were determined to be 0.3 mM of H2O2 and 0.10 mg/cm3 of PEG with molar mass of 1.0 × 104 g/mol in a pH 7.0 buffer at 30°C. A variety of bisphenol derivatives were completely or effectively treated by SBP under the optimum conditions determined for treatment of BPA, although the SBP dose was further increased as necessary for some of them. The aggregation of water‐insoluble oligomers generated was enhanced by decreasing the pH values of the solutions to 4.0 with HCl after the enzymatic treatment, and BPA and bisphenol derivatives were removed from aqueous solutions by filtering off the oligomer precipitates. © 2010 American Institute of Chemical Engineers Environ Prog, 2011
Optimum design and experimental study of multiple tuned mass dampers with limited stroke
Authors: Lin Chi‐Chang , Wang Jer‐Fu , Lien Chien‐Hsun , Chiang Hung‐Wei , Lin Chih‐Shiuan
Published: April 2010

This paper develops a two‐stage optimum design procedure for multiple tuned mass dampers (MTMD) to reduce structural dynamic responses with the limitation of MTMD's stroke. A new performance index, which is a linear combination of structural response ratio and MTMD stroke ratio by a weighting factor α, is proposed; α is in the range from 0 to 1.0. The larger the α, the more important the stroke. The case of α=1.0 indicates that MTMD is locked. The analytical results show that the MTMD's stroke can be significantly suppressed with little sacrifice of structural control effectiveness when an appropriate α is selected. To verify the design algorithm, a 360 kg‐MTMD composed of five TMD units arranged in parallel was fabricated. Shaking table tests of a large‐scale three‐story building with and without the MTMD under earthquake excitations were conducted at the National Center for Research on Earthquake Engineering (NCREE) in Taiwan. The experimental results show that MTMD is not only effective in mitigating the building responses but also is successful in suppressing its stroke. Copyright © 2010 John Wiley & Sons, Ltd.
Performance of clay masonry veneer in wood‐stud walls subjected to out‐of‐plane seismic loads
Authors: Okail Hussein O. , Shing P. Benson , Klingner Richard E. , McGinley William M.
Published: April 2010

This paper presents the findings of shaking‐table experiments conducted to examine the out‐of‐plane seismic performance of masonry veneer walls. Seven wall assemblies were tested, each consisting of a clay masonry veneer anchored to a wood‐stud backing. Design variables include the type of veneer ties, tie spacing, and presence or absence of mortar joint reinforcement and window opening. The walls were designed and constructed in accordance with current US code provisions. Results of the experiments show that failure of the corrugated ties is governed by pullout of the nails from the wood studs, while failure of the rigid ties is governed by detachment from the mortar joints or pull‐through of the screw heads through fastener holes. Both types of ties show satisfactory performance under ground motions corresponding to Design Basis and Maximum Considered Earthquakes representative of Seismic Design Category E. Although the rigid ties were stronger than the corrugated ties, they had wider vertical spacing and failed at a slightly higher seismic load. Observed extraction capacities of the nails show high variability, which merits attention. Joint reinforcement did not show any noticeable effect on the out‐of‐plane behavior of the veneer. Results of an analytical study have shown that the detachment of a veneer from the backing system is preceded by veneer cracking, which influences the distribution of tie forces, and that the vertical tie spacing influences the cracking load for the veneer. Copyright © 2010 John Wiley & Sons, Ltd.
Anorexia nervosa: Towards an integrative neuroscience model
Authors: Hatch A. , Madden S. , Kohn M. , Clarke S. , Touyz S. , Williams L. M.
Published: April 2010

We reviewed the evidence for emotion‐related disturbances in anorexia nervosa (AN) from behavioural, cognitive, biological and genetic domains of study. These domains were brought together within the framework of an integrative neuroscience model that emphasizes the role of emotion and feeling and their regulation, in brain organization. PsychInfo and Medline searches were performed to identify published peer‐reviewed papers on AN within each domain. This review revealed evidence for ‘Emotion’, ‘Thinking and Feeling’ and ‘Self‐regulation’ disturbances in AN that span non‐conscious to conscious processes. An integrative neuroscience framework was then applied to develop a model of AN, from which hypotheses for empirical investigation are generated. We propose that AN reflects a core disturbance in emotion at the earliest time stage of information processing with subsequent effects on the later stages of thinking, feeling and self‐regulation. Copyright © 2010 John Wiley & Sons, Ltd and Eating Disorders Association.
Differences in sensitivity but not selectivity of xenoestrogen binding to alligator versus human estrogen receptor alpha
Authors: Rider Cynthia V. , Hartig Phillip C. , Cardon Mary C. , Lambright Christy R. , Bobseine Kathy L. , Guillette Louis J. , Gray L. Earl , Wilson Vickie S.
Published: April 2010

Reproductive abnormalities in alligators exposed to contaminants in Lake Apopka, Florida, USA represent a clear example of endocrine disruption in wildlife. Several of these contaminants that are not able to bind to mammalian estrogen receptors (such as atrazine and cyanazine) have previously been reported to bind to the alligator estrogen receptor from oviductal tissue. Binding of known Lake Apopka contaminants to full length estrogen receptors alpha from human (hERα) and alligator (aERα) was assessed in a side-by-side comparison within the same assay system. Baculovirus-expressed recombinant hERα and aERα were used in a competitive binding assay. Atrazine and cyanazine were not able to bind to either receptor. p,p′-Dicofol was able to bind to aERα with a concentration inhibiting 50% of binding (IC50) of 4 µM, while only partially displacing 17β-estradiol (E2) from hERα and yielding a projected IC50 of 45 µM. Chemicals that only partially displaced E2 from either receptor, including some dichlorodiphenyltrichloroethane (DDT) metabolites and trans-nonachlor, appeared to have higher affinity for aERα than hERα. p,p′-Dicofol-mediated transcriptional activation through aERα and hERα was assessed to further explore the preferential binding of p,p′-dicofol to aERα over hERα. p,p′-Dicofol was able to stimulate transcriptional activation in a similar manner with both receptors. However, the in vitro results obtained with p,p′-dicofol were not reflected in an in vivo mammalian model, where Kelthane™ (mixed o,p′- and p,p′-dicofol isomers) did not elicit estrogenic effects. In conclusion, although there was no evidence of exclusively species-specific estrogen receptor binders, some xenoestrogens, especially p,p′-dicofol, had a higher affinity for aERα than for hERα. Environ. Toxicol. Chem. 2010;29:2064–2071. © 2010 SETAC
Comparison of metal concentrations inCorbicula flumineaandElliptio hopetonensisin the Altamaha River system, Georgia, USA
Authors: Shoults-Wilson W. Aaron , Unrine Jason M. , Rickard James , Black Marsha C.
Published: April 2010

The present study evaluated the use of the invasive clam Corbicula fluminea as a surrogate for metal accumulation in native mussels. The tissue concentrations of As, Cd, Cu, Hg, Mn, Ni, Pb, and Zn were analyzed in Corbicula and a native Unionid mussel species (Elliptio hopetonensis) collected from 13 sites in the Altamaha River system (GA, USA). Corbicula accumulated greater concentrations of As, Cd, Cu, Hg, and Ni when compared to E. hopetonensis at the same sites. The reverse was true for the metals Mn and Zn, with E. hopetonensis accumulating greater concentrations than Corbicula. Concentrations of As, Cd, Cu, Hg, and Pb were found to be significantly (α = 0.05) positively correlated between the two species. Greater water alkalinity and hardness tended to negatively correlate with metal accumulation, while organism size tended to correlate positively with tissue concentrations. Tissue Cd, Cu, and Pb concentrations demonstrated a correlation between bivalve tissues and concentrations of those metals in fine sediments. These correlations were significant (α = 0.05) for Cd and Cu concentrations in Corbicula and Pb concentrations in E. hopetonensis. The present findings support the hypothesis that bioaccumulation of some metals by Corbicula can be used to approximate levels accumulated by co-occurring native mussel species. Environ. Toxicol. Chem. 2010;29:2026–2033. © 2010 SETAC
Rhizotoxic effects of silver in cowpea seedlings
Authors: Blamey F. Pax C. , Kopittke Peter M. , Wehr J. Bernhard , Kinraide Thomas B. , Menzies Neal W.
Published: April 2010

Silver (Ag) is highly toxic to aquatic organisms, including algae, invertebrate animals, and fish, but little information exists on Ag rhizotoxicity in higher plants. In two solution culture experiments with approximately 1,000 µM Ca(NO3)2 and 5 µM H3BO3 (pH 5.4), 20 to 80% of added Ag (≤2 µM) was lost from solution within approximately 30 min, with a further decrease after 48 h root growth. Using measured Ag concentrations at the start of the experiments, the median effective concentration (EC50) for root elongation rate of cowpea (Vigna unguiculata [L.] Walp. cv. Caloona) was 0.010 µM Ag in the first 4 h of exposure (0.021 µM in the first 8 h). This demonstrates that Ag (as Ag+) is rapidly rhizotoxic to cowpea seedlings at concentrations similar to those that are toxic to freshwater biota. Rupturing of rhizodermal and outer cortical layers was evident after 48 h with 0.13 to 0.57 µM Ag initially in solution, being most severe at 0.13 or 0.25 µM Ag. An additional experiment showed that ruptures were first evident after 20 h exposure to 0.17 µM Ag, with increased severity of rupturing over time. The rhizotoxic effects of Ag are similar to those of some other trace metals (e.g., Cu, Al, La) that bind strongly to hard ligands and weakly to soft ligands. The similarity of rupturing effects, despite the difference in strong binding to soft ligands by Ag and to hard ligands by the other metals, suggests a distinctive metabolic effect of Ag that binds only weakly to hard ligands. Environ. Toxicol. Chem. 2010;29:2072–2078. © 2010 SETAC
The effect of fire‐retardant additives and a surface insulative fabric on fire performance and mechanical property retention of polyester composites
Authors: Kandare Everson , Chukwunonso Anajemba K. , Kandola Baljinder K.
Published: April 2010

This study investigates the simultaneous use of conventional fire‐retardant additives and an insulative intumescent thermal barrier/mat to improve the fire performance and mechanical property retention of glass‐fibre‐reinforced polyester (GRP) composites. Significant reductions in the peak heat release rate (PHRR) and total heat release (THR) were observed from measured cone calorimetric data following the addition of nitrogen, phosphorous, halogen containing and hydroxylated fire‐retardant additives. Some fire‐retarded glass‐fibre‐reinforced composites further protected by an intumescent mat containing silicate fibres, expandable graphite and borosilicate glass bound together by an organic matrix show further reductions in PHRR. Despite improving the fire retardancy of the composites, the presence of fire‐retardant additives alone does not improve flexural modulus retention following exposure to a heat source. However, the introduction of a ‘passive’ fire proofing insulative fabric enhances fire performance while preserving the mechanical properties of composites exposed to high heat fluxes or fires. Copyright © 2010 John Wiley & Sons, Ltd.
Hazards of combustion products: Toxicity, opacity, corrosivity, and heat release: The experts' views on capability and issues
Authors: Gann Richard G. , Babrauskas Vytenis , Grayson Stephen J. , Marsh Nathan D.
Published: April 2010

The science of understanding how fires burn and how heat smoke and gases are generated and affect people has progressed substantially in the last half century. The principles of facility design for life safety in fires have reached a degree of maturity. Standards and code provisions for fire detection, suppression and control have become the norm. Real‐scale (or nearly real‐scale) test methods for the flammability of furnishings and interior finish have been established. In addition, some tests have been developed that measure the results of the burning of a small sample from the finished product. Yet, while there have been numerous small‐scale apparatuses developed for assessing the generation of heat, toxic gases, and visible or corrosive smoke, these facets of life and property safety have not found widespread inclusion in building and fire codes. There has been an invigorated effort in ISO TC92 SC3, Fire Threat to People and the Environment, to develop a coherent and comprehensive set of fire safety standards and guidance documents for life safety. Smaller efforts are ongoing within some national and regional standards bodies. In November 2008, experts in this field gathered at The Royal Society in London to hear papers that captured the state of the art and to discuss where we might go from here. This paper summarizes the papers and the discussion from that meeting. Copyright © 2010 John Wiley & Sons, Ltd.
Frequent epigenetic inactivation of Myocardin in human nasopharyngeal carcinoma
Authors: Chen Fu , Mo Yingxi , Ding Hao , Xiao Xue , Wang Shu Yi , Huang Guangwu , Zhang Zhe , Wang Sheng Zi
Published: April 2010

Background

Epigenetic silencing of tumor suppressor genes plays an important role in nasopharyngeal carcinoma (NPC) tumorigenesis. In the present study, we explore a novel target gene of epigenetic silencing in NPC, Myocardin, which is inactivated by promoter hypermethylation.

Methods

Transcriptional expression levels of Myocardin were evaluated by reverse transcription–polymerase chain reaction (RT‐PCR). Methylation status was addressed by methylation‐specific PCR and bisulfite genomic sequencing.

Results

Myocardin mRNA expression was inactivated in 4 of 5 NPC cell lines. Myocardin was aberrantly methylated in 4 of 5 NPC cell lines (80%) and in 48 of 65 NPC primary tumors (73.8%, but not in any of the 12 normal nasopharyngeal tissues tested. Myocardin expression could be reactivated in NPC cells after treatment with the demethylating agent 5‐aza‐2′‐deoxycytidine (5‐aza‐dC).

Conclusions

Epigenetic inactivation of Myocardin is a frequent and tumor‐specific event in NPC. Our findings suggest that Myocardin is a candidate tumor suppressor gene in NPC. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Intensity‐modulated radiotherapy for locally advanced cancers of the larynx and hypopharynx
Authors: Daly Megan E. , Le Quynh‐Thu , Jain Anshu K. , Maxim Peter G. , Hsu Annie , Loo Billy W. , Kaplan Michael J. , Fischbein Nancy J. , Colevas A. Dimitrios , Pinto Harlan , Chang Daniel T.
Published: April 2010

Background

Limited data evaluate intensity‐modulated radiotherapy (IMRT) for cancers of the hypopharynx and larynx. We report clinical outcomes and failure patterns for these patients.

Methods

Between September 2001 and December 2007, 42 patients with squamous cell carcinoma (SCC) of the hypopharynx (n = 23) and larynx (n = 19) underwent IMRT, 11 postoperatively and 31 definitively. Thirty‐six received systemic therapy. Median follow‐up was 30 months among surviving patients.

Results

Three local failures occurred within the high‐dose region and 3 occurred in regional nodes. Seven patients developed distant metastasis as the initial failure. Three‐year actuarial estimates of locoregional control, freedom from distant metastasis, and overall survival rates were, respectively, 80%, 72%, and 46%.

Conclusions

IMRT provides good locoregional control for SCC of the hypopharynx and larynx compared with historical controls. Locoregional relapses occurred in the high‐dose volumes, suggesting adequate target volume delineation. Hypopharyngeal tumors, which fare worse than laryngeal tumors, warrant investigation of more aggressive treatment. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Percutaneous treatment of facial venous malformations: A matched comparison of alcohol and bleomycin sclerotherapy
Authors: Spence Jessica , Krings Timo , TerBrugge Karel G. , Agid Ronit
Published: April 2010

Background

Venous malformations (VMs) are common vascular anomalies; 40% are found in the head and neck. Percutaneous sclerotherapy is 1 treatment of choice.

Methods

In all, 17 patients with facial VMs were treated by percutaneous sclerotherapy using alcohol and individually matched to lesions treated with bleomycin. Treatment details and outcomes were compared. The average numbers of sessions were 1.7 for alcohol and 3.4 for bleomycin. Average dose administered was 8.1 cm3 alcohol and 9.1 units bleomycin.

Results

Of those treated with alcohol, 2 developed adverse effects and 7 developed complications. None treated with bleomycin developed adverse effects or complications. All patients treated with alcohol improved clinically. In all, 15 patients treated with bleomycin improved after treatment and 2 were unchanged.

Conclusions

Alcohol has a slightly higher success rate and requires fewer treatment sessions. Bleomycin has a lower complication rate and less postprocedural swelling. Bleomycin treatment may be better tolerated and is thus preferred over alcohol sclerotherapy. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Genomic profiling of sinonasal squamous cell carcinoma
Authors: López Fernando , Llorente José L. , García‐Inclán Cristina , Alonso‐Guervós Marta , Cuesta‐Albalad Mari Paz , Fresno Manuel Florentino , Álvarez‐Marcos César , Suárez Carlos , Hermsen Mario A.
Published: April 2010

Background

Sinonasal squamous cell carcinomas (SCCs) are rare tumors with no etiologic link to tobacco and alcohol, as opposed to other SCCs of the head and neck (HNSCC). Little is known about the genetic changes in sinonasal SCC.

Methods

DNA copy number changes of sinonasal SCC were analyzed by multiplex ligation‐dependent probe amplification (MLPA) and microarray comparative genomic hybridization (maCGH), and results were related to clinicopathologic features.

Results

Copy number losses most frequently included genes at 9p21, 13q14, 17p13, 17q21, and 18q11. Frequent gains were observed on 8q24, 11q13, 17q12, 19p13, and 20q11–q13.

Conclusion

The genomic profile of sinonasal SCC showed a number of chromosomal regions with copy number changes similar to those known in HNSCC, in spite of the differences in etiology. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Association between bisphosphonates and jaw osteonecrosis: A study in Wistar rats
Authors: Maahs Marcia P. , Azambuja Alan A. , Campos Maria M. , Salum Fernanda G. , Cherubini Karen
Published: April 2010

Background

This work aimed at determining whether bisphosphonate therapy produces a sufficient condition for jaw osteonecrosis after tooth extraction.

Methods

Rats were allocated into 3 groups: (1) 11 rats treated with alendronate, (2) 10 rats treated with zoledronic acid, and (3) 10 control rats. The animals were subjected to tooth extractions, and at the end of bisphosphonate therapy, they were humanely killed. Histologic sections of the surgical site were processed and analyzed.

Results

The zoledronic acid group showed higher incidences of osteonecrosis, inflammatory infiltrate, and microorganisms. There was no significant difference for epithelial or connective tissue, root fragments, vital bone, and positive staining for vascular endothelial growth factor (VEGF) among the groups.

Conclusion

Zoledronic acid is associated with jaw osteonecrosis, whereas alendronate did not produce a condition sufficient for osteonecrosis after tooth extraction. Neither zoledronic acid nor alendronate was associated with a reduced immunohistochemical expression of VEGF in vital bone at the tooth extraction site. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Meeting the challenge of identifying persistent pollutants at the state level
Authors: Hope Bruce K , Stone David , Fuji Taku , Gensemer Robert W , Jenkins Jeffrey
Published: April 2010

In 2007, the State of Oregon enacted legislation aimed at identifying persistent pollutants that could pose a threat to waters of the State and then reducing their discharge by means of a comprehensive pollution prevention program. This legislation defined a persistent pollutant as one that is toxic and persistent or bioaccumulative; a broad definition that required evaluation of an extensive number and variety of chemicals. The Oregon Department of Environmental Quality, in consultation with a science workgroup, implemented a 12-step process for identifying and prioritizing persistent pollutants consistent with this definition. This process is characterized by (a) maximum overall transparency in its conduct, including extensive public involvement, (b) 3 levels of objective and predefined criteria for categorization of a chemical as a persistent pollutant, (c) full disclosure of values and sources for all physicochemical data used for comparison with these criteria, and (d) clear acknowledgement when a chemical was identified as a persistent pollutant for reasons other than these criteria alone. This process was used to identify those chemicals relevant as persistent pollutants and to then prioritize them in terms of their relative ability to adversely impact waters of the state, with special emphasis on impacts to aquatic receptors. An initial list of 2130 chemicals was compiled from existing lists. Criteria for toxicity, persistence, and bioaccumulative potential were defined and then used with 2 different chemical property evaluation models (PBT Profiler and EPISuite) to produce a final list of 118 chemicals. The final list includes several legacy pollutants but also contains numerous current-use pharmaceuticals, personal care products, and pesticides, approximately half of which appear only once or not at all on lists compiled by others. Although it drew from the experience of others, assembling this list proved to be an exemplar of science in the service of policy. Integr Environ Assess Manag 2010;6:735–748. © 2010 SETAC
Acute atrazine exposure disrupts matrix metalloproteinases and retinoid signaling during organ morphogenesis in Xenopus laevis
Authors: Lenkowski Jenny R. , McLaughlin Kelly A.
Published: April 2010

Exposure to the herbicide atrazine disrupts many developmental processes in non‐target animals. Atrazine exposure during organ morphogenesis in amphibians results in dramatic malformations; the mechanism by which this happens has not been described. We have taken a candidate gene approach to explore two possible mechanisms by which acute atrazine exposure causes extensive malformations in several tissues in Xenopus laevis tadpoles. Using a static renewal system, we exposed tadpoles to atrazine for 6–48 h during organ morphogenesis (Nieuwkoop and Faber stage 42). We observed degradation of cranial cartilage and differentiated muscle in the head, gut and somites of exposed tadpoles. Additionally, transcript levels of matrix metalloproteinases (MMPs), specifically both MMP9TH and MMP18, increased in atrazine‐exposed tadpoles in a dose–response test, and MMP18 increased as early as 6 h after exposure began. Gelatinase MMP activity was also altered by atrazine exposure, indicating that atrazine disrupts gene function at the level of transcription and protein activity. Furthermore, transcript levels of the enzyme Xcyp26, an enzyme in the retinoic acid signaling pathway, significantly decreased in the intestines of tadpoles exposed to 10 or 35 mg l−1 atrazine for 48 h. Our results suggest two mechanisms by which atrazine can disrupt tissue morphogenesis: through misregulation of MMPs that are critical in extracellular matrix remodeling throughout development and the disruption of retinoic acid signaling. This study begins to describe conserved vertebrate developmental processes that are disrupted by atrazine exposure. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of orthopedic polymer particles on chemotaxis of macrophages and mesenchymal stem cells
Authors: Huang Zhinong , Ma Ting , Ren Pei‐Gen , Smith R. Lane , Goodman Stuart B.
Published: April 2010

Wear particles generated from total joint arthroplasty (TJA) stimulate macrophages to release chemokines. The role of chemokines released from wear particle‐stimulated macrophages on the migration of macrophages and osteoprogenitor cells in vitro has not been elucidated. In this study, we challenged murine macrophages (RAW 264.7) with clinically relevant polymethyl methacrylate (PMMA, 1‐10 μm) and ultra high molecular weight polyethylene (UHMWPE, 2‐3 μm) particles. The chemotactic effects of the conditioned media (CM) were tested in vitro using human macrophages (THP‐1) and human mesenchymal stem cells (MSCs) as the migrating cells. CM collected from both particle types had a chemotactic effect on human macrophages, which could be eliminated by monocyte chemotactic protein‐1 (MCP‐1) neutralizing antibody. Blocking the CCR1 receptor eliminated the chemotactic effect, while CCR2 antibody only partially decreased THP‐1 cell migration. CM from PMMA but not UHMWPE‐exposed macrophages led to chemotaxis of MSCs; this effect could be eliminated by macrophage inflammatory protein‐1 alpha (MIP‐1α) neutralizing antibody. Neither CCR1 nor CCR2 blocking antibodies showed an effect on the migration of MSCs. Chemokines released by macrophages stimulated by wear particles can have an effect on the migration of macrophages and MSCs. This effect seems to be dependent on the particle type, and may be modulated by MCP‐1 and MIP‐1α, however, more than one chemokine may be necessary for chemotaxis. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
PML down‐regulation in soft tissue sarcomas
Authors: Vincenzi Bruno , Perrone Giuseppe , Santini Daniele , Grosso Federica , Silletta Marianna , Frezza Annamaria , Rossi Sabrina , Russo Antonio , Rabitti Carla , Gebbia Nicola , Badalamenti Giuseppe , Casali Paolo , Muda Andrea Onetti , dei Tos Angelo Paolo , Tonini Giuseppe
Published: April 2010

To date, little is known concerning the promyelocytic leukemia gene (PML) status in tumors of different origin, and its expression has never been evaluated in soft tissue sarcoma. The aim of the present study is focused on the identification of differences in terms of PML protein expression between different types of soft tissue sarcoma and the corresponding normal surrounding tissue. PML protein expression has been assessed by immunohistochemistry in six different histologic types of soft tissue sarcoma (synovial sarcoma, myofibroblastic sarcoma, angiosarcoma, liposarcoma, pleomorphic sarcoma, and leiomyosarcoma) and in the corresponding normal surrounding tissue. PML resulted significantly down‐regulated in synovial sarcoma and in myofibroblastic sarcoma specimens. Also in angiosarcoma samples a significative difference in PML expression in comparison with normal specimens has been detected. Interestingly PML protein detection showed a different pattern of expression in the three liposarcoma histology types compared with corresponding nontumoral tissues. In particular PML protein resulted significantly down‐regulated in myxoid liposarcoma and in dedifferentiated liposarcoma. On the contrary no statistically significant difference was observed in pleomorphic liposarcoma compared to normal tissue specimens. Further investigations are needed to confirm these data and to assess the possible value of PML expression as a prognostic factor in these extremely aggressive diseases. J. Cell. Physiol. 224: 644–648, 2010. © 2010 Wiley‐Liss, Inc.
Eco‐friendly, solvent‐free novel one‐pot, three‐component synthesis of quinazolinones at ambient temperature catalyzed by silica gel‐supported phosphomolybdic acid
Authors: Sabitha Gowravaram , Reddy N. Mallikarjuna , Prasad M. Nagendra , Raja G. S. K. , Yadav J. S.
Published: April 2010

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Silica gel supported Phosphomolybdic acid (PMA.SiO2) catalyzes efficiently the one‐pot three‐component coupling reaction of anthranilic acid, orthoesters, and amines at room temperature to afford 4(3H)‐Quinazolinones in high to excellent yields under solvent‐free conditions. The supported catalyst can be recovered and reused. J. Heterocyclic Chem., (2010).