bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac computed tomography compared to transthoracic echocardiography in the management of congenital heart disease
Authors: Beier Ulf H. , Jelnin Vladimir , Jain Supriya , Ruiz Carlos E.
Published: August 2006

Objectives: To compare cardiac CT and transthoracic echocardiography (TTE) as diagnostic utilities in congenital heart disease (CHD) and to determine their advantages and limitations. Background:TTE is widely used in the evaluation of CHD. Recent reports suggested an increasing role of CT. However, there are few quantitative data on its diagnostic accuracy. Methods:We investigated a total of 162 patients (51.24% male; mean age: 16.06 ±± 17.92) with congenital heart defects, who underwent electron beam CT (EBCT) and TTE between March 2002 and June 2005. We retrospectively analyzed a total of 667 findings, stratified for age and anatomic categories. Results: EBCT and TTE findings are concordant in patients below 1 year of age (85.43% agreement). EBCT had poor sensitivity and specificity in detecting anomalies of cardiac chambers (0.68, 0.58), but was useful for great arteries (0.91, 0.85). Furthermore, sensitivity and specificity were remarkably different in systemic venous return (0.93, 0.3) and coronary vessels (0.8, 0.33) because of “false positive” findings, which were later found to be most likely real findings not detectable by reference standard. The opposite was true for cardiac valves (0.66, 0.89) and septa (0.76, 0.91). Conclusions: EBCT delineates findings related to systemic venous return and coronary vessels well due to simultaneous visualization of complex anatomy. This advantage does not seem to apply in patients below 1 year of age with better acoustic windows. TTE was found more suitable for cardiac valves and septal defects because of the availability of flow imaging. © 2006 Wiley‐Liss, Inc.
Environmentally Friendly One‐Pot Synthesis of α‐Alkylated Nitriles Using Hydrotalcite‐Supported Metal Species as Multifunctional Solid Catalysts
Authors: Motokura Ken , Fujita Noriaki , Mori Kohsuke , Mizugaki Tomoo , Ebitani Kohki , Jitsukawa Koichiro , Kaneda Kiyotomi
Published: August 2006

A ruthenium‐grafted hydrotalcite (Ru/HT) and hydrotalcite‐supported palladium nanoparticles (Pdnano/HT) are easily prepared by treating basic layered double hydroxide, hydrotalcite (HT, Mg6Al2(OH)16CO3) with aqueous RuCl3⋅n H2O and K2[PdCl4] solutions, respectively, using surface impregnation methods. Analysis by means of X‐ray diffraction, and energy‐dispersive X‐ray, electron paramagnetic resonance, and X‐ray absorption fine structure spectroscopies proves that a monomeric RuIV species is grafted onto the surface of the HT. Meanwhile, after reduction of a surface‐isolated PdII species, highly dispersed Pd nanoclusters with a mean diameter of about 70 Å is observed on the Pdnano/HT surface by transmission electron microscopy analysis. These hydrotalcite‐supported metal catalysts can effectively promote α‐alkylation reactions of various nitriles with primary alcohols or carbonyl compounds through tandem reactions consisting of metal‐catalyzed oxidation and reduction, and an aldol reaction promoted by the base sites of the HT. In these catalytic α‐alkylations, homogeneous bases are unnecessary and the only by‐product is water. Additionally, these catalyst systems are applicable to one‐pot syntheses of glutaronitrile derivatives.
Regularity of the obstacle problem for a fractional power of the laplace operator
Authors: Silvestre Luis
Published: August 2006

Given a function φ and s ∈ (0, 1), we will study the solutions of the following obstacle problem:

u ≥ φ in ℝn,

(−▵)su ≥ 0 in ℝn,

(−▵)su(x) = 0 for those x such that u(x) > φ(x),

lim|x| → + ∞ u(x) = 0.

We show that when φ is C1, s or smoother, the solution u is in the space C1, α for
every α < s. In the case where the contact set {u = φ} is convex, we prove the
optimal regularity result u ∈ C1, s. When φ is only C1, β for a β < s, we prove
that our solution u is C1, α for every α < β. © 2006 Wiley Periodicals, Inc.
Linear matrix inequality representation of sets
Authors: Helton J. William , Vinnikov Victor
Published: August 2006

This article concerns the question, Which subsets of ℝm can be represented with linear matrix inequalities (LMIs)? This gives some perspective on the scope and limitations of one of the most powerful techniques commonly used in control theory. Also, before having much hope of representing engineering problems as LMIs by automatic methods, one needs a good idea of which problems can and cannot be represented by LMIs. Little is currently known about such problems. In this article we give a necessary condition that we call “rigid convexity,” which must hold for a set 𝒞 ⊆ ℝm in order for 𝒞 to have an LMI representation. Rigid convexity is proved to be necessary and sufficient when m = 2. This settles a question formally stated by Pablo Parrilo and Berndt Sturmfels in [15]. As shown by Lewis, Parillo, and Ramana [11], our main result also establishes (in the case of three variables) a 1958 conjecture by Peter Lax on hyperbolic polynomials. © 2006 Wiley Periodicals, Inc.
Petri net model of protocol conversion for CTF service: its universal coupling criteria and property analysis
Authors: Zhu Xiaomin , Liao Jianxin , Chen Junliang
Published: August 2006

Protocol conversion is a critical issue requiring much research attention. In this paper, the protocol conversion methodology proposed originally by Green is extended with the Petri nets theory to study application layer protocol conversion among more than two interfaces. The click‐to‐fax (CTF) service based on the Internet intelligent network (IIN) model is taken as an example to illustrate the extended part. A two‐step Petri net modelling method is proposed, which is easier compared to constructing the overall model directly in just one step. Universal coupling criteria of Petri net model of protocol conversion (PNPC) are abstracted. The PNPC of CTF service is analysed using analytical techniques of Petri nets, which are proved to be effective in finding and eliminating potential bugs. The necessity of the concept of service layer is also emphasized. Copyright © 2006 John Wiley & Sons, Ltd.
Fine‐needle aspiration of soft tissue leiomyosarcoma: An analysis of the most common cytologic findings and the value of ancillary techniques
Authors: Domanski Henryk A. , Åkerman Måns , Rissler Pehr , Gustafson Pelle
Published: August 2006

This study aims to determine the diagnostic accuracy of fine‐needle aspiration cytology (FNAC) of primary leiomyosarcoma (LMS) of soft tissue and to review diagnostic criteria and adjunctive methods, which can contribute to a confident diagnosis.

We evaluated the preoperative FNAC in 89 patients with primary LMS for the following: cytomorphology and correspondence of FNA to histological features of excised tumors and clinical data. In addition, the utility of adjunctive techniques was analyzed and other spindle‐cell lesions in the differential diagnoses were discussed.

An unequivocal, malignant diagnosis was rendered by FNAC in 78 cases; 74 tumors were diagnosed as sarcoma, of which 31 as LMS or suspicion of LMS. In addition, three smears were labeled as malignant tumor, one as carcinoma metastasis, and three as neurilemmoma. Seven aspirates were inconclusive and one insufficient. On reevaluation, the diagnostic smears in most cases contained tumor cell fascicles with an admixture of dispersed cells or stripped nuclei. The most common cells were spindle cells with elongated, blunt‐ended, segmented or fusiform nuclei, and round/polygonal cells, often with rounded or indented nuclei. In addition, 51 cases showed pleomorphic, often multinucleated cells. Osteoclasts, intranuclear vacuoles, and mitoses occurred in 14, 47, and 27 cases, respectively. Thus, most high‐grade LMSs have cytologic features that allow diagnosis of sarcoma. Ancillary studies can confirm the diagnosis of LMS and help in the correct interpretation of predominant spindle‐cell or epitheloid‐cell smears resembling neurilemoma or carcinoma, respectively. Diagn. Cytopathol. 2006;34:597–604. © 2006 Wiley–Liss, Inc.
Dlx5 and Dlx6 homeobox genes are required for specification of the mammalian vestibular apparatus
Authors: Robledo Raymond F. , Lufkin Thomas
Published: August 2006

The mammalian inner ear is a complex organ that develops from a surface ectoderm into distinct auditory and vestibular components. Congenital malformation of these two components resulting from single or multiple gene defects is a common clinical occurrence and is observed in patients with split hand/split foot malformation, a malformation which is phenocopied by Dlx5/6 null mice. Analysis of mice lacking Dlx5 and Dlx6 homeobox genes identified their restricted and combined expression in the otic epithelium as a crucial regulator of vestibular cell fates. Otic induction initiates without incident in Dlx5/6−/− embryos, but dorsal otic derivatives including the semicircular ducts, utricle, saccule, and endolymphatic duct fail to form. Dlx5 and Dlx6 seem to influence vestibular cell fates by restricting Pax2 and activating Gbx2 and Bmp4 expression domains. Given their proximity to the disease locus and the observed phenotype in Dlx5/6 null mice, Dlx5/6 are likely candidates to mediate the inner ear defects observed in patients with split hand/split foot malformation. genesis 44:425–437, 2006. © 2006 Wiley‐Liss, Inc.
Commentary on ‘Antibiotics for acute pyelonephritis in children’
Authors: Grimm Paul
Published: August 2006

This is a commentary on a Cochrane review, published in this issue of EBCH, first published as: Bloomfield P, Hodson EM, Craig JC. Antibiotics for acute pyelonephritis in children. Cochrane Database of Systematic Reviews 2005, Issue 1. Art. No.: CD003772. DOI: 10.1002/14651858.CD003772.pub2.

Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Characteristics and Key Findings Tables articles. Copyright © 2006 John Wiley & Sons, Ltd.
Characteristics and key findings for ‘Interventions to improve antibiotic prescribing practices in ambulatory care’
Authors: van Dalen Elvira , Offringa Martin , Kremer Leontien
Published: August 2006

These are the characteristics and key findings for a Cochrane review, published in this issue of EBCH, first published as: Arnold SR, Straus SE. Interventions to improve antibiotic prescribing practices in ambulatory care. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD003539. DOI: 10.1002/14651858.CD003539.pub2.

Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Expert Commentary articles. Copyright © 2006 John Wiley & Sons, Ltd.
Commentary on ‘Neuromuscular paralysis for newborn infants receiving mechanical ventilation’
Authors: Bellù R.
Published: August 2006

This is a commentary on a Cochrane review, published in this issue of EBCH, first published as: Cools F, Offringa M. Neuromuscular paralysis for newborn infants receiving mechanical ventilation. Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD002773. DOI: 10.1002/14651858.CD002773.pub2.

Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Characteristics and Key Findings Tables articles. Copyright © 2006 John Wiley & Sons, Ltd.
A wide‐field‐of‐view catadioptrical head‐mounted display
Authors: Nagahara Hajime , Yagi Yasushi , Yachida Masahiko
Published: August 2006

The head‐mounted display (HMD) has been used widely as a visual presentation device in virtual reality, composite reality, and telepresence. However, the HMDs which are on the market have only a very narrow angular field of view, which is less than 60°in the horizontal direction. This is very narrow compared to the human field of view and is far from generating a feeling of presence. The poor feeling of presence is considered to be a factor that degrades the sense of realism for the user and the operating efficiency in the virtual space. In this paper, we propose an HMD with a wide field of view based on a catadioptrical system composed of hyperboloidal and ellipsoidal mirrors. The proposed HMD achieves a horizontal view angle of 180°, which covers the human peripheral field of vision. This wide field of view gives the user a stronger feeling of reality and ambience. The proposed HMD has a binocular overlap area of 60°from the center, which helps to achieve stereoscopic vision by presenting parallax images. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 89(9): 33–43, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20304
Rapid CD40‐mediated rescue from CD95‐induced apoptosis requires TNFR‐associated factor‐6 and PI3K
Authors: Benson Rebecca J. , Hostager Bruce S. , Bishop Gail A.
Published: August 2006

The activation molecule CD40 and the death receptor CD95/Fas play important roles in regulating B cells so that effective antimicrobial immunity occurs without autoimmunity. CD40 signaling increases CD95 expression, sensitizing cells to apoptosis, but sustained CD40 signals rescue B cells from CD95 killing. Here we describe a mechanism of early CD40‐mediated rescue from CD95‐induced apoptosis in B cells. Maximal rescue was achieved when CD40 signals were given within 1–2 h of initiating CD95 apoptosis. CD40 signaling did not block association of Fas‐associated death domain‐containing protein with CD95, but decreased CD95‐induced activation of caspases 3 and 8. Rapid CD40 rescue did not require NF‐κB activation and was independent of de novo protein synthesis, but was dependent upon active PI3 K. Signaling via a CD40 mutant that does not bind TNFR‐associated factor (TRAF)1, TRAF2, and TRAF3 rescued B cells from CD95‐induced apoptosis. TRAF1/2/3‐independent rescue was confirmed in B cell lines made deficient in these TRAF molecules by gene targeting. In contrast, CD40 rescue was completely abrogated in TRAF6‐deficient B cells, which showed reduced activation of Akt in response to CD40 engagement. These results reveal a new rapid mechanism to balance B cell activation and apoptosis.
Regional wind fields and dunefield migration, southern Brazil
Authors: Hesp Patrick , Abreu de Castilhos Janete , Miot da Silva Graziela , Dillenburg Sergio , Martinho Caroline Thais , Aguiar Débora , Fornari Michele , Fornari Milene , Antunes Glauco
Published: August 2006

This paper examines a seemingly anomalous situation in southern Brazil where the dunefields on Santa Catarina Island (e.g. Joaquina Beach) migrate to the NNW, almost completely the opposite direction (c. 160) to the dunefields immediately to the south (e.g. Pinheira Beach), and some much further to the north (e.g. Cabo Frio) which migrate to the SSW. A variety of mechanisms are examined to explain the differences in dunefield migration including grain size variations, topographic effects on local winds, shoreline orientation, and regional wind field changes. The mean grain sizes of the two beaches, Pinheira and Joaquina, are not sufficiently different to restrict aeolian sediment transport in either place, nor to account for a lack of transport from the NNE to the SSW in the case of Joaquina. Some topographic steering of the wind is likely but could not account for the long‐term average difference in migration trends of the island dunefields compared to the mainland dunefields. While the orientation of the shoreline to prevailing winds is an important control on beach and dune sediment transport, it is not the dominant controlling mechanism. An analysis of the regional wind patterns demonstrates that there is a major shift in the regional wind field near the island such that the dominant island winds blow from the SW/SSW while those further south blow from the NE. It is concluded that this is the predominant reason for the divergence in the direction of migration of the dunefields. Copyright © 2006 John Wiley & Sons, Ltd.
Metabolite profile of sibutramine in human urine: a liquid chromatography‐electrospray ionization mass spectrometric study
Authors: Link Marek , Hakala Kati S. , Wsól Vladimír , Kostiainen Risto , Ketola Raimo A.
Published: August 2006

We present a detailed experimental approach to detection and subsequent structural characterization of unknown metabolites of sibutramine, using liquid chromatography‐mass spectrometric techniques. The full‐, precursor ion, and constant neutral loss scan modes of a triple quadrupole mass spectrometer were used for screening sibutramine metabolites in human urine. The structural assessment of unknown metabolites was based on MSn ion trap mass spectrometric analysis and comparison of MSn spectra between the standards and compounds detected. Two phase‐I (M1 and M2) and eight phase‐II (M3‐M6) metabolites of sibutramine were found in human urine. Metabolites M1 and M2, which were found as minor metabolites, originated from N‐demethylation of sibutramine. Carbamoyl glucuronides formed from metabolites M1, M2, and their hydroxylated analogs were the main metabolites of sibutramine and were characterized by tandem mass spectrometric analysis and by the chemical modification of their structure. We demonstrate the usefulness of the chemical derivatization approach for estimation of the site of glucuronidation and propose the formation of hydroxylated regioisomers of metabolites M4 and M6. Copyright © 2006 John Wiley & Sons, Ltd.
An assessment of the suitability of a plastic thermometer screen for climatic data collection
Authors: Perry M. C. , Prior M. J. , Parker D. E.
Published: August 2006

For over a century, wooden thermometer screens of the Stevenson design have been used in the meteorological station network administered by the UK Met Office. A screen is now being manufactured of the same dimensions but made from plastic. This requires minimal maintenance and has the potential for a much longer life than the wooden type. In order to determine whether a changeover to the plastic type would be acceptable for climatological applications, in particular for studies of climate change, a 12‐month trial was carried out at 3 contrasting UK locations. Temperature and relative humidity measurements were made at 1‐minute intervals in plastic and wooden trial screens installed at each site, as well as in the existing operational wooden screens. At the start of the trial, acceptance criteria based on Global Climate Observing System (GCOS) standards were set for mean and extreme temperature values. The temperature differences between the trial wooden and plastic screens were all found to be within these acceptance criteria. The largest differences occurred between pairs of wooden screens, not between wooden and plastic screens. Analysis of humidity differences between wooden and plastic screens did not yield clear results. To help understand the temperature and humidity differences, the screen data were analysed in terms of other current weather conditions, principally solar radiation and wind speed. We recommend that, in temperate climates, the plastic thermometer screen is a climatologically consistent alternative to the wooden design, requiring no adjustments to long‐term records. © Crown Copyright 2006. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd.
Plants, medicines and man
Authors: Fowler Michael W
Published: August 2006

Plants have long been a source of therapeutic agents used by man. Some 80% of the world's population still rely upon plants for primary health care; even today in Western medicine, and despite progress in synthetic chemistry, some 25% of prescription medicines are still derived either directly or indirectly from plants. The use of plants in medicines ranges from crude preparations or extracts, to refined extracts and single molecular species. In terms of categories of use this encompasses food supplements, herbal medicines, botanical drugs and prescription medicines. Increased interest in plants as a source of novel pharmacophores recognizes their chemical diversity and versatility, not matched by synthetic chemistry libraries. In spite of the surge of activity in synthetic chemistry over the last 20 years or so, almost half the some 850 small molecules introduced as drugs were derived from plant sources. Over 100 small molecules derived either directly or indirectly from plants are currently at some point in the clinical trials process. It is argued that the present use of plant‐derived drugs and remedies only scratches the surface of what is a major reservoir of untapped potential, the level of biological and chemical diversity possessed by plants having much to offer in the drive for novel therapeutic agents in the fight against disease. Additionally novel developments in plant biotechnology and molecular biology add further dimensions to the use of plants in the production of therapeutic agents. Copyright © 2006 Society of Chemical Industry
Light scattering effects of gold nanoparticles in cells:
FDTD modeling
Authors: Tanev S , Tuchin V V , Paddon P
Published: August 2006

The FDTD modeling approach is applied to study the
implementation of the optical immersion technique for the
visualization of single and multiple gold nanoparticles in
biological cells. To the best knowledge of authors, this is the
first research study discussing the gold nanoparticle effects on
the forward scattered light from biological cells at refractive
index matching conditions. The applicability and the potential of
the FDTD approach for studying gold nanoparticles enhanced
bio-imaging at optical immersion is demonstrated.
Deformation theorems on non‐metrizable vector spaces and applications to critical point theory
Authors: Bartsch Thomas , Ding Yanheng
Published: August 2006

Let E be a Banach space and Φ : E → ℝ a 𝒞1‐functional. Let 𝒫 be a family of semi‐norms on E which separates points and generates a (possibly non‐metrizable) topology 𝒯𝒫 on E weaker than the norm topology. This is a special case of a gage space, that is, a topological space where the topology is generated by a family of semi‐metrics. We develop some critical point theory for Φ : (E, 𝒫) → ℝ. In particular, we prove deformation lemmas where the deformations are continuous with respect to 𝒯𝒫. In applications this yields a gain in compactness when Φ does not satisfy the Palais–Smale condition because one can work with the weak topology.

We also prove some foundational results on gage spaces. In particular, we introduce the concept of Lipschitz continuity in this setting and prove the existence of Lipschitz continuous partitions of unity. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrospun Nanofibers Modified with Phospholipid Moieties for Enzyme Immobilization
Authors: Huang Xiao‐Jun , Xu Zhi‐Kang , Wan Ling‐Shu , Innocent Christophe , Seta Patrick
Published: August 2006

Summary: PANCMPCs containing phospholipid side moieties were electrospun into nanofibers with a mean diameter of 90 nm. Field emission SEM was used to characterize the morphologies of the nanofibers. These phospholipid‐modified nanofibers were explored as supports for enzyme immobilization due to the characteristics of excellent biocompatibility, high surface/volume ratio, and porosity, which were beneficial to the catalytic efficiency and activity of immobilized enzymes. Lipase from Candida rugosa was immobilized on these nanofibers by adsorption. Preliminary results indicated that the properties of the immobilized lipase on these phospholipid‐modified nanofibers were greatly promising.

Schematic representation of the structure and electrostatic properties of phospholipid‐modified nanofibers.

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Schematic representation of the structure and electrostatic properties of phospholipid‐modified nanofibers.
Mechanism of Dithiobenzoate‐Mediated RAFT Polymerization: A Missing Reaction Step
Authors: Buback Michael , Vana Philipp
Published: August 2006

Summary: The debate on the mechanism of dithiobenzoate‐mediated RAFT polymerization may be resolved by including the reaction between a propagating radical and the star‐shaped combination product from irreversible termination into the kinetic scheme. By this step, a highly reactive propagating radical and a not overly stable three‐arm star species are transformed into the resonance‐stabilized RAFT intermediate radical and a very stable polymer molecule. The time evolution of concentrations is discussed for the main‐equilibrium range of CDB‐mediated methyl acrylate polymerization.

Illustration of the novel understanding of the RAFT mechanism in dithiobenzoate‐mediated RAFT polymerization.

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Illustration of the novel understanding of the RAFT mechanism in dithiobenzoate‐mediated RAFT polymerization.
Developing new enrichment functions for crack simulation in orthotropic media by the extended finite element method
Authors: Asadpoure A. , Mohammadi S.
Published: August 2006

New enrichment functions are proposed for crack modelling in orthotropic media using the extended finite element method (XFEM). In this method, Heaviside and near‐tip functions are utilized in the framework of the partition of unity method for modelling discontinuities in the classical finite element method. In this procedure, by using meshless based ideas, elements containing a crack are not required to conform to crack edges. Therefore, mesh generation is directly performed ignoring the existence of any crack while the method remains capable of extending the crack without any remeshing requirement. Furthermore, the type of elements around the crack‐tip remains the same as other parts of the finite element model and the number of nodes and consequently degrees of freedom are reduced considerably in comparison to the classical finite element method. Mixed‐mode stress intensity factors (SIFs) are evaluated to determine the fracture properties of domain and to compare the proposed approach with other available methods. In this paper, the interaction integral (M‐integral) is adopted, which is considered as one of the most accurate numerical methods for calculating stress intensity factors. Copyright © 2006 John Wiley & Sons, Ltd.
Parallel universal approach to mesh motion and application to rotors in forward flight
Authors: Allen C. B.
Published: August 2006

Numerical simulation of unsteady flows including moving boundaries, whether rigid, prescribed, or deforming, requires the mesh to move/deform also. Many approaches to mesh motion have been considered, but the approach adopted often depends on both the meshing approach used and the proposed application. A universal approach to grid motion is presented here. The method developed has several important properties, the most significant of which is that the scheme requires no grid point connectivity information, i.e. each point can be moved totally independently to its neighbours. This has two major implications: first, it means the scheme is universal, i.e. applicable to any grid type, unstructured, hybrid or structured single‐ and multiblock. Second, and equally as important, is that the scheme is perfectly parallel, as no communication is required between points/blocks. Each block can be updated independently to its neighbours so there is no connectivity data required, and this also means the flow‐solver does not have to carry the grid motion parameterization data in memory. The scheme accounts for moving surface rotations as well as displacements, and this ensures grid quality is preserved by maintaining orthogonality. The method is applied to a four‐bladed lifting rotor in forward flight. This is a particularly challenging unsteady problem as there are multiple bodies in relative motion, each one with its own axis system, as each blade has a cyclic pitch variation. Grid quality is proven to be preserved even when a large deformation case is considered and, significantly, the scheme adds only around 1% to the cost of a flow solution real time step. Copyright © 2006 John Wiley & Sons, Ltd.
Etanercept for therapy‐resistant macrophage activation syndrome
Authors: Makay Balahan , Yılmaz Şebnem , Türkyılmaz Zeynep , Ünal Nurettin , Ören Hale , Ünsal Erbil
Published: August 2006

Macrophage activation syndrome (MAS) is a severe, potentially fatal complication of childhood rheumatic diseases, especially systemic onset juvenile idiopathic arthritis (SoJIA). We report a 4‐year‐old girl with probable SoJIA who presented with MAS. She did not respond to pulse methyl prednisolone and Cyclosporine A (CsA). She also failed to respond to intravenous immunoglobulin (IVIG) therapy. Etanercept was started, based on the observation of increased serum levels of tumor necrosis factor‐alpha (TNF‐α) in patients with MAS. Her condition improved following etanercept, suggesting that etanercept might have a therapeutic role in resistant MAS. Pediatr Blood Cancer 2008;50:419–421. © 2006 Wiley‐Liss, Inc.
Preparation and characterization of MPEG–PCL diblock copolymers with thermo‐responsive sol–gel–sol phase transition
Authors: Kim Moon Suk , Hyun Hoon , Seo Kwang Su , Cho Young Ho , Won Lee Jung , Rae Lee Chang , Khang Gilson , Lee Hai Bang
Published: August 2006

MPEG–PCL diblock copolymers consisting of methoxy polyethylene glycol (MPEG, 750 g/mol) and poly(ϵ‐caprolactone) (PCL) were synthesized by ring‐opening polymerization. Aqueous solutions of the synthesized diblock copolymers were prepared by dissolving the MPEG–PCL diblock copolymers at concentrations in the range of 0–20 wt %. When the PCL molecular weight was 3000 or greater, the polymer was only partially soluble in water. As the temperature was increased from room temperature, the diblock copolymer solutions showed two phase transitions: a sol‐to‐gel transition and a gel‐to‐sol transition. The sol‐to‐gel phase transition temperature decreased substantially with increasing PCL length. The sol–gel–sol transition with the increase in temperature was confirmed by monitoring the viscosity as a function of temperature. The temperature ranges of the phase transitions measured by the tilting method were in full agreement with those determined from the viscosity measurements. The maximum viscosity of the copolymer solution increased with increasing hydrophobicity of the diblock copolymer and with increasing copolymer concentration. X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses revealed that the diblock copolymers exhibited crystalline domains that favored the formation of an aggregated gel because of the tight aggregation and strong packing interactions between PCL blocks. Scanning electron micrographs of the diblock copolymer solutions in the sol state showed interconnected polyhedral pore structures, whereas those of the gel state revealed a fibrillar‐like morphology. Atomic force microscope (AFM) studies of the sol and gel surfaces showed that the sol surface was covered with fine globular particles, whereas the gel surface was covered with particles in micron‐scale irregular islets. These findings are consistent with uniform mixing of the diblock copolymer and water in the sol state, and aggregation of PCL blocks in the gel state. In conclusion, we confirm that the MPEG–PCL diblock copolymer solution exhibited a sol–gel–sol transition as a function of temperature. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5413–5423, 2006
The Use of an Exact Light‐Scattering Theory for Spheroidal TiO2 Pigment Particles
Authors: Jalava Juho‐Pertti
Published: August 2006

Titanium dioxide pigments are widely used, e.g., in paints, printing inks, plastics, and papers, because of the excellent and whiteness they provide. As is well known, the opacity and to it related optical properties depend on the pigment's crystal‐ and particle‐size distributions (CSD, PSD). Therefore, the process and quality control of the CSD and PSD are very essential. The development of a straightforward and sophisticated method for process and quality control is presented here. The principal component is a new determination method for the PSD based on an accurate theory of light scattering of spheroidal particles. In this new method, called the turbidity spectrum method (TSM), the whole turbidity spectrum is measured. This spectrum, which is due to the particle‐size distribution of the pigment particles, is then solved using the T‐matrix method by taking into account the shape of the particles. After that the CSD is extracted from the PSD. The T‐matrix method is one of the most powerful and widely used tools for the rigorous computing of electromagnetic scattering by non‐spherical particles. The repeatability of the mean PSD (∼200 nm) obtained by the TSM is excellent, with a standard deviation of 0.1 nm (0.05 %). Linear regression models based on TSM results were developed for undertone and tint‐reducing power, which are important optical parameters of the pigment. The excellent repeatability of the TSM results was necessary for the production of representative models.
NanoParticle Tracking Analysis – The Halo™ System
Authors: Malloy Andrew , Carr Bob
Published: August 2006

A new technique for nanoparticle sizing that allows visualisation of nanoscale particles in liquids on an individual basis is described. The technology comprises a metallised optical element illuminated by laser beam at the surface of which nanoscale particles in suspension can be directly visualised, sized and counted in real time using only a conventional optical microscope fitted with a low cost camera and a dedicated analytical software package.
The identification of dispersive and non‐dispersive intermediate frequency modes of HiPco single walled carbon nanotubes by in situ Raman spectroelectrochemistry
Authors: Kalbac Martin , Kavan Ladislav , Zukalova Marketa , Dunsch Lothar
Published: August 2006

The intermediate frequency modes (IFM) of HiPco single walled carbon nanotubes (SWCNT) were analyzed by in situ Raman spectroelectrochemistry. We demonstrate that dispersive and non‐dispersive IFM features show a different dependence on electrochemical charging. While during p ‐doping the dispersive IFM features exhibit much stronger shift than non‐dispersive IFM ones, during n ‐doping an opposite effect was observed. Therefore we propose the application of the Raman spectroelectrochemical method for the identification of dispersive and non‐dispersive features using only one laser energy excitation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isotope abundance analysis methods and software for improved sample identification with supersonic gas chromatography/mass spectrometry
Authors: Alon Tal , Amirav Aviv
Published: August 2006

We present newly developed isotope abundance analysis (IAA) methods and software which are used to derive elemental formula information from experimental mass spectral data of molecular ion isotopomeric abundances. The software, using a novel method, can also be used to automatically confirm or reject NIST library search results, thereby significantly improving the confidence level in sample identifications. In the case of IAA confirmation of the NIST library results, sample identification is unambiguous, since the confirmation is achieved by two independent sets of data and analytical methods. In the case of a rejection, such as when the molecule is not included in the library's databases, the IAA software independently provides a list of elemental formulae with declining order of matching to the isotopomeric experimental data, in a similar way to accurate mass measurements with costly instruments. IAA is ideally applicable to gas chromatography/mass spectrometry (GC/MS) (and liquid chromatography/electron ionization mass spectrometry (LC/EI‐MS)) with a supersonic molecular beam (SMB) since it requires a trustworthy and highly abundant true molecular ion that is unique to the SMB‐MS systems, plus the absence of self chemical ionization and vacuum background noise, again unique features of GC/SMB‐MS. The various features of the IAA methods and software are described, their performance is demonstrated with the analysis of experimental GC‐SMB‐MS data and the IAA concept is compared with accurate mass alternatives. The combination of IAA and GC/SMB‐MS is believed to be superior to accurate mass GC/MS in view of the general availability of trustworthy molecular ions for an extended range of compounds. Copyright © 2006 John Wiley & Sons, Ltd.
Comparison of satellite and cellular architectures for downlink broadcast data transmission
Authors: Sridhar Adarsh , Ephremides Anthony
Published: August 2006

Traditional voice and video‐oriented networks such as the cellular and satellite networks are being increasingly used to carry data traffic. We endeavour to compare the downlink broadcast performance of the two architectures against each other on the basis of energy consumption, end‐to‐end delay and maximum stable throughput. The architectures are modelled as systems of Geo/G/1 queues. Queuing theory arguments and then sample‐path based comparisons are used to show that the satellite architecture while being more energy‐efficient has a higher delay and a lower maximum throughput. The variation of energy and delay with the total number of receiver nodes is also studied. Copyright © 2006 John Wiley & Sons, Ltd.
Submarine venting of liquid carbon dioxide on a Mariana Arc volcano
Authors: Lupton John , Butterfield David , Lilley Marvin , Evans Leigh , Nakamura Ko‐ichi , Chadwick William , Resing Joseph , Embley Robert , Olson Eric , Proskurowski Giora , Baker Edward , de Ronde Cornel , Roe Kevin , Greene Ronald , Lebon Geoff , Young Conrad
Published: August 2006

Although CO2 is generally the most abundant dissolved gas found in submarine hydrothermal fluids, it is rarely found in the form of CO2 liquid. Here we report the discovery of an unusual CO2‐rich hydrothermal system at 1600‐m depth near the summit of NW Eifuku, a small submarine volcano in the northern Mariana Arc. The site, named Champagne, was found to be discharging two distinct fluids from the same vent field: a 103°C gas‐rich hydrothermal fluid and cold (<4°C) droplets composed mainly of liquid CO2. The hot vent fluid contained up to 2.7 moles/kg CO2, the highest ever reported for submarine hydrothermal fluids. The liquid droplets were composed of ∼98% CO2, ∼1% H2S, with only trace amounts of CH4 and H2. Surveys of the overlying water column plumes indicated that the vent fluid and buoyant CO2 droplets ascended <200 m before dispersing into the ocean. Submarine venting of liquid CO2 has been previously observed at only one other locality, in the Okinawa Trough back‐arc basin (Sakai et al., 1990a), a geologic setting much different from NW Eifuku, which is a young arc volcano. The discovery of such a high CO2 flux at the Champagne site, estimated to be about 0.1% of the global MOR carbon flux, suggests that submarine arc volcanoes may play a larger role in oceanic carbon cycling than previously realized. The Champagne field may also prove to be a valuable natural laboratory for studying the effects of high CO2 concentrations on marine ecosystems.
Longitudinal flow evolution and turbulence structure of dynamically similar, sustained, saline density and turbidity currents
Authors: Gray T. E. , Alexander Jan , Leeder Mike R.
Published: August 2006

Experimental results are presented concerning flow evolution and turbulence structure of sustained saline and turbidity flows generated on 0°, 3°, 6°, and 9° sloping ramps that terminate abruptly onto a horizontal floor. Two‐component velocity and current density were measured with an ultrasonic Doppler velocity profiler and siphon sampler on the slope, just beyond the slope break and downstream on the horizontal floor. Three main factors influence longitudinal flow evolution and turbulence structure: sediment transport and sedimentation, slope angle, and the presence of a slope break. These controls interact differently depending on flow type. Sediment transport is accompanied by an inertial fluid reaction that enhances Reynolds stresses in turbidity flows. Thus turbidity flows mix more vigorously than equivalent saline density flows. For saline flows, turbulent kinetic energy is dependent on slope, and rapid deceleration occurs on the horizontal floor. For turbidity flows, normalized turbulent kinetic energy increases downstream, and mean streamwise deceleration is reduced compared with saline flows. The slope break causes mean bed‐normal velocity of turbidity flows to become negative and have a gentler gradient compared with other locations. A reduction of peak Reynolds normal stress in the bed‐normal direction is accompanied by an increase in turbulent accelerations across the rest of the flow thickness. Thus the presence of particles acts to increase Reynolds normal stresses independently of gradients of mean velocity, and sediment transport increases across the break in slope. The experiments illustrate that saline density currents may not be good dynamic analogues for natural turbidity currents.
Switch‐off of a major enhanced ice flow unit in East Antarctica
Authors: Rippin David M. , Siegert Martin J. , Bamber Jonathan L. , Vaughan David G. , Corr Hugh F. J.
Published: August 2006

The East Antarctic Ice Sheet (EAIS) is the largest reservoir of ice on the planet by an order of magnitude. Compared with the West Antarctic Ice Sheet (WAIS), it is traditionally considered to be relatively stable, with only minor adjustments to its configuration over glacial‐interglacial cycles. Here, we present the results of a radio‐echo sounding survey from Coats Land, East Antarctica, which suggests that parts of the EAIS outlet drainage system may have changed significantly since the Last Glacial Maximum. We have identified an enhanced flow unit from buckled internal layering and smooth bed morphology that is no longer active. We believe this feature to have shut down at some point since the Last Glacial Maximum, ∼20 ka BP.
Accelerated melting of Himalayan snow and ice triggers pronounced changes in a valley peatland from northern India
Authors: Rühland Kathleen , Phadtare Netajirao R. , Pant Rajendra K. , Sangode Satish J. , Smol John P.
Published: August 2006

The Himalayan region of northern India depends on monsoon rains, together with snow and glacial melt, to supply life‐sustaining water to one of the world's most densely populated areas. Here we provide high‐resolution pollen and diatom evidence from a peat deposit in the Pinder Valley that shows a synchronous and abrupt ecosystem turnover toward a wetter state in the last two centuries that exceeded changes recorded over the last three millennia. Contrary to expectations, there was no relationship between recent proxy changes and summer monsoon precipitation. Strong relationships, however, were found with winter climate data. We link this recent unprecedented wetness to marked warming at higher elevations resulting in increased seasonal runoff and associated climatic feedbacks in this snow and ice‐melt dominated region. In contrast to the expected desiccation and decomposition of most peat systems with warming, this site has instead become the wettest in its ca. 3500‐year history.
Nonlinear Neurovascular Coupling in Rat Sensory Cortex by Activation of Transcallosal Fibers
Authors: Hoffmeyer Henrik W , Enager Pia , Thomsen Kirsten J , Lauritzen Martin J
Published: August 2006

Functional neuroimaging and normal brain function rely on the robust coupling between neural activity and cerebral blood flow (CBF), that is neurovascular coupling. We examined neurovascular coupling in rat sensory cortex in response to direct stimulation of transcallosal pathways, which allows examination of brain regions inaccessible to peripheral stimulation techniques. Using laser-Doppler flowmetry to record CBF and electrophysiologic recordings of local field potentials (LFPs), we show an exponential relation between CBF responses and summed LFP amplitudes. Hemodynamic responses were dependent on glutamate receptor activation. CNQX, an AMPA receptor blocker, strongly attenuated evoked CBF responses and LFP amplitudes at all stimulation frequencies. In comparison, N-methyl d-aspartate (NMDA) receptor blockade by MK801 attenuated CBF responses at high (>7 Hz) but not low (<7 Hz) stimulation frequencies, without affecting evoked LFP amplitudes. This shows the limitation of using LFP amplitudes as indicators of synaptic activity. 7-Nitroindazole, a neuronal nitric oxide synthase inhibitor, and indomethacin, a nonspecific cyclooxygenase inhibitor, attenuated the hemodynamic responses by 50%±1% and 48%±1%, respectively, without affecting LFP amplitudes. The data suggest that preserved activity of both AMPA and NMDA receptors is necessary for the full CBF response evoked by stimulation of rodent interhemispheric connections. AMPA receptor activation gives rise to a measurable LFP, but NMDA receptor activation does not. The lack of a measurable LFP from neural processes that contribute importantly to CBF may explain some of the difficulties in transforming extracellular current or voltage measurements to a hemodynamic response.
Stroke-Evoked Angiogenesis Results in a Transient Population of Microvessels
Authors: Yu Sung Wook , Friedman Beth , Cheng Qun , Lyden Patrick D
Published: August 2006

The role of angiogenesis after stroke is unclear; if angiogenesis supports long-term recovery of blood flow, then microvessel hyperdensity consequent to angiogenesis should persist in infarcted cortex. Here, we assess the long-term stability of ischemia-induced microvessels after 2-h transient rat middle cerebral artery occlusion (tMCAo) followed by 30, 90, or 165 days of reperfusion. Stereological measures of microvessel density were taken adjacent to and within cortical cysts. Vascular permeability was documented by extravasation of immunoglobulin (IgG) and of fluorescein-dextran. After 30 days reperfusion, a significantly increased microvessel volume density ( VV) was restricted to the inner margin of cystic infarcts as compared with the region external to the infarct or contralateral control cortex (F = 42.675, P < 0.001). The hyperdense ischemic vasculature was abnormally leaky to IgG and fluorescein-dextran. Between 30 and 90 days of reperfusion, this vessel hyperdensity regressed significantly and then regressed further but less drastically between 90 and 165 days. Phagocytic macrophages were restricted to the infarct and dynamic changes in their number correlated with microvessel regression. Additional ED-1 labeled inflammatory cells were widely distributed inside and external to the infarct, even after 165 days of reperfusion. These data show that ischemia evoked angiogenesis results, at least in part, in transient populations of leaky microvessels and phagocytic macrophages. This suggests that a major role of this angiogenesis is for the removal of necrotic brain tissue.
Cobalt-substituted SnO2 thin films: A transparent ferromagnetic semiconductor
Authors: Gopinadhan K. , Pandya Dinesh K. , Kashyap Subhash C. , Chaudhary Sujeet
Published: August 2006

A maximum room temperature ferromagnetic moment of 0.47μB∕Co ion has been observed in Sn0.9Co0.1O2−δ films grown by spray pyrolysis. The films have high conductivity (∼150Ω−1cm−1) and ∼70% transmittance in the visible region. A systematic variation of saturation magnetization, carrier concentration, electrical conductivity, and optical transmission edge in Sn1−xCoxO2−δ(0.05⩽x⩽0.15) films is correlated with the change in Co concentration, and a carrier mediated Ruderman-Kittel-Kasuya-Yoshida interaction has been proposed as the most probable mechanism for the ferromagnetic ordering. The maximum blueshift in the transmission edge by ∼215meV (at x=0.10) is attributed to the extra carriers generated by Co substitution.