bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeted inhibition of the EGFR pathways enhances Zn‐BC‐AM PDT‐induced apoptosis in well‐differentiated nasopharyngeal carcinoma cells
Authors: Koon Ho‐Kee , Chan Pui‐Shan , Wong Ricky Ngok‐Shun , Wu Zhen‐Guo , Lung Maria Li , Chang Chi‐Kwong , Mak Nai‐Ki
Published: October 2009

Epidermal growth factor receptor (EGFR), a receptor often expressed in nasopharyngeal carcinoma (NPC) cells, is one of the recently identified molecular targets in cancer treatment. In the present study, the effects of combined treatment of Zn‐BC‐AM PDT with an EGFR inhibitor AG1478 were investigated. Well‐differentiated NPC HK‐1 cells were subjected to PDT with 1 µM of Zn‐BC‐AM and were irradiated at a light dose of 1 J/cm2 in the presence or absence of EGFR inhibitor AG1478. Specific protein kinase inhibitors of downstream EGFR targets were also used in the investigation. EGFR, Akt, and ERK were found constitutively activated in HK‐1 cells and the activities could be inhibited by the EGFR inhibitor AG1478. A sub‐lethal concentration of AG1478 was found to further enhance the irreversible cell damage induced by Zn‐BC‐AM PDT in HK‐1 cells. Pre‐incubation of the cells with specific inhibitors of EGFR (AG1478), PI3k/Akt (LY294002), or MEK/ERK (PD98059) before light irradiation were found to enhance Zn‐BC‐AM PDT‐induced formation of apoptotic cells. The efficacy of Zn‐BC‐AM PDT can be increased through the inhibition of EGFR/PI3K/Akt and EGFR/MEK/ERK signaling pathways in NPC cells. Combination therapy with Zn‐BC‐AM PDT and EGFR inhibitors may further be developed for the treatment of advanced NPC. J. Cell. Biochem. 108: 1356–1363, 2009. © 2009 Wiley‐Liss, Inc.
Stability and individual change in depressive symptoms among mothers raising young children with ASD: maternal and child correlates
Authors: Carter Alice S. , Martínez‐Pedraza Frances de L. , Gray Sarah A. O.
Published: October 2009

Mothers raising children with Autism Spectrum Disorders (ASD) evidence elevated depressive symptoms, but symptom stability has not been examined. Mothers (N=143) of toddlers with ASD (77% boys) were enrolled and assessed when their children were 18 to 33 months old and followed annually for 2 years. Multilevel modeling revealed no significant change in group depressive symptom level, which was in the moderately elevated range (Intercept=13.67; SE=.96). In contrast, there was significant individual variation in change over time. Child problem behaviors and delayed competence, maternal anxiety symptoms and angry/hostile mood, low parenting efficacy and social supports, and coping styles were associated with depression severity. Only maternal anxiety and parenting efficacy predicted individual change. Many mothers do not appear to adapt, supporting the need for early intervention for maternal well‐being. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–11, 2009.
Energy transfer in master equation simulations: A new approach
Authors: Barker John R.
Published: October 2009

Collisional energy transfer plays a key role in recombination, unimolecular, and chemical activation reactions. For master equation simulations of such reaction systems, it is conventionally assumed that the rate constant for inelastic energy transfer collisions is independent of the excitation energy. However, numerical instabilities and nonphysical results are encountered when normalizing the collision step‐size distribution in the sparse density of states regime at low energies. It is argued here that the conventional assumption is not correct, and it is shown that the numerical problems and nonphysical results are eliminated by making a plausible assumption about the energy dependence of the rate coefficient for inelastic collisions. The new assumption produces a model that is more physically realistic for any reasonable choice of collision step‐size distribution, but more work remains to be done. The resulting numerical algorithm is stable and noniterative. Testing shows that overall accuracy in master equation simulations is better with this new approach than with the conventional one. This new approach is appropriate for all energy‐grained master equation formulations. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 748–763, 2009
Spectroscopic studies on the dynamics of charge‐transfer interaction of pantoprazole drug with DDQ and iodine
Authors: Pandeeswaran M. , El‐Mossalamy E. H. , Elango K. P.
Published: October 2009

Spectrophotometric method was used to study the kinetics of charge‐transfer (CT) complexes of pantoprazole with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and iodine. The reactions of DDQ and iodine with pantoprazole have been investigated in different solvents at three different temperatures. The products of the interactions have been isolated and characterized using UV–vis, GC‐MS, FT‐IR, and far‐IR spectral techniques. The rate of formation of the product has been measured and discussed as a function of solvents and temperature. The iodine complex indicates the formation of the tri‐iodide CT complex with a general formula [(PTZ)I]+I. The characteristic strong absorptions of I are observed around 360 and 290 nm in the electronic spectra, and the far‐IR spectrum exhibits three characteristic vibrations of I unit at 156, 112, and 69 cm−1 assigned to νas(I‐I), νs(I‐I), and δ(I), respectively. The activation parameters (ΔG#, ΔS#, and ΔH#) were obtained from the temperature dependence of the rate constants. The influence of relative permittivity of the medium on the rate indicated that the intermediate is more polar than the reactants, and this observation was further well supported by spectral studies. Based on the spectrokinetic results, plausible mechanisms for the interaction of the drug with the chosen acceptors, which proceed via the formation of CT complexes and its transformation into final products, have been proposed. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 787–799, 2009
Comparison of clinical outcomes of oral erythroleukoplakia treated with photodynamic therapy using either light‐emitting diode or laser light
Authors: Yu Chuan‐Hang , Lin Hung‐Pin , Chen Hsin‐Ming , Yang Hsiang , Wang Yi‐Ping , Chiang Chun‐Pin
Published: October 2009

Background and Objectives

Topical 5‐aminolevulinic acid‐mediated photodynamic therapy (topical ALA‐PDT) using a 635‐nm light‐emitting diode (LED) light is an effective treatment modality for oral verrucous hyperplasia. This study tested whether topical ALA‐PDT using either the LED or laser light was also an effective treatment modality for oral erythroleukoplakia (OEL) lesions.

Study Design/Materials and Methods

In this prospective but non‐randomized study, 20 OEL lesions were treated with topical ALA‐PDT using the 635‐nm LED light and 26 OEL lesions were treated with topical ALA‐PDT using the 635‐nm laser light. The difference in clinical outcomes was compared between the two groups by Fisher exact test.

Results

We found that the 20 LED light‐treated OEL lesions showed complete response (CR) in 17 and partial response (PR) in 3. The 17 CR OEL lesions required an average of 3.7 (range, 2–7) treatments of ALA‐PDT to achieve CR of the lesions. The 26 laser light‐treated OEL lesions showed CR in 25 and PR in 1. The 25 CR OEL lesions needed an average of 3.3 (range, 2–6) treatments of ALA‐PDT to achieve CR of the lesions. There was no significant difference in PDT outcomes between the 20 LED light‐treated and 26 laser light‐treated OEL lesions (P = 0.303). When the 42 CR OEL lesions were pooled together, we found that smaller lesions (greatest diameter <1.5 cm) and lesions with thinner surface keratin (keratin layer ≤30 µm) needed significantly fewer mean treatment number of PDT to achieve a CR than the larger lesions (P = 0.000) and lesions with thicker surface keratin (P = 0.000), respectively.

Conclusions

Topical ALA‐PDT using either the LED or laser light is an effective treatment modality for OEL lesions. There is no significant difference in clinical outcomes of OEL lesions treated with PDT using either the LED or laser light. Lasers Surg. Med. 41:628–633, 2009. © 2009 Wiley‐Liss, Inc.
Semi‐Automated method of analysis of horizontal histological sections of skin for objective evaluation of fractional devices
Authors: Zelickson Brian D. , Walgrave Susan E. , Al‐Arashi Munir Yahya H. , Altshuler Gregory B. , Yaroslavsky Ilya V. , Childs James J. , Cohen Rich H. , Erofeev Andrei V. , Depina Erminaldo F. , Smirnov Mikhail Z. , Kist David A. , Tabatadze David R.
Published: October 2009

Background and Objective

The treatment of skin with fractional devices creates columns of micro‐ablation or micro‐denaturation depending on the device. Since the geometric profiles of thermal damage depend on the treatment parameters or physical properties of the treated tissue, the size of these columns may vary from a few microns to a few millimeters. For objective evaluation of the damage profiles generated by fractional devices, this report describes an innovative and efficient method of processing and evaluating horizontal sections of skin using a novel software program.

Materials and Methods

Ex vivo porcine skin was treated with the Lux1540/10, Lux1540 Zoom and Lux2940 with 500 optics. Horizontal (radial) sections of biopsies were obtained and processed with H&E and NBTC staining. Digital images of the histologic sections were taken in either transmission or reflection illumination and were processed using the SAFHIR program.

Results

NBTC‐ and H&E‐stained horizontal sections of ex vivo skin treated with ablative and non‐ablative fractional devices were obtained. Geometric parameters, such as depth, diameter, and width of the coagulated layer (if applicable), and micro‐columns of thermal damage, were evaluated using the SAFHIR software. The feasibility of objective comparison of the performance of two different fractional devices was demonstrated.

Conclusion

The proposed methodology provides a comprehensive, objective, and efficient approach for the comparison of various fractional devices. Correlation of device settings with the objective dimensions of post‐treatment damage profiles serve as a powerful tool for the prediction and modulation of clinical response. Lasers Surg. Med. 41:634–642, 2009. © 2009 Wiley‐Liss, Inc.
Does display sensitivity influence motor latency determination?
Authors: Takahashi Nobushige , Robinson Lawrence R.
Published: October 2009

It is known that display sensitivity can affect onset latency measurement of compound muscle action potentials (CMAPs). We compared two display sensitivities with respect to intrarater and interrater reliability and measured to what degree display sensitivity influences the motor latency. We asked seven raters to mark the onset points of median CMAPs from 24 patients printed with display sensitivities of 5 mV/division and 0.5 mV/division on paper. The onset latencies were measured, and intraclass correlation coefficients (ICCs) were calculated. Most of the raters had excellent intrarater repeatability within a single sensitivity display setting. In contrast, the intrarater reliability using two different sensitivity settings was poor. ICCs calculated for interrater reliability were 0.93 at 0.5 mV/division and 0.91 at 5 mV/division. On average, the latencies measured at 5 mV/division were about 0.3 ms longer. We conclude that reliability of latency measurement is excellent at either sensitivity; however, it is important to use a consistent sensitivity in order to avoid making measuring errors. Muscle Nerve, 2009
Effects of CL316,243, a β3‐adrenoceptor agonist, and intravesical prostaglandin E2on the primary bladder afferent activity of the rat
Authors: Aizawa Naoki , Igawa Yasuhiko , Nishizawa Osamu , Wyndaele Jean‐Jacques
Published: October 2009

Aims

It has been suggested that β3‐adrenoceptor (β3‐AR) agonists affect not only the efferent but also the afferent pathways innervating the bladder. In addition, prostaglandin E2(PGE2) causes bladder hyperactivity in conscious rats. We investigated the direct effects of a β3‐AR agonist (CL316,243; CL) and PGE2on single fiber activities of the primary bladder afferent nerves.

Methods

Female Sprague–Dawley rats were used. Under urethane anesthesia, a single nerve fiber primarily originating from the bladder was identified by electrical stimulation of the left pelvic nerve and by bladder distention, and was divided by conduction velocity (2.5 m/sec) as Aδ‐fiber or C‐fiber. The afferent activity measurements with constant bladder filling were repeated three times and the third measurement served as the base‐line observation. Then, CL (10 µg/kg) or its vehicle was administrated intravenously. Thereafter, 10−4 M of PGE2or saline was instilled intravesically and another three cycles recorded.

Results

Forty‐three single afferent fibers (Aδ‐fibers: n = 20, C‐fibers: n = 23) were isolated from 34 rats. Intravenous administration of CL, but not vehicle, significantly decreased Aδ‐fiber, but not C‐fiber, activities in response to bladder filling with saline. Intravesical instillation of PGE2significantly increased C‐fiber activities, but not Aδ‐fiber activities. The PGE2‐induced increase in C‐fiber activities was inhibited by pretreatment with CL.

Conclusions

The present results clearly demonstrate that the β3‐AR agonist, CL316,243, can inhibit the mechanosensitive Aδ‐fibers, but not the C‐fibers, of the primary bladder afferents of the rat. In addition, the β3‐AR agonist can inhibit PGE2‐induced C‐fiber hyperactivity. Neurourol. Urodynam. 29:771–776, 2010. © 2010 Wiley‐Liss, Inc.
Project Management and High-Value Superyacht Projects: An Improvisational and Temporal Perspective
Authors: Leybourne Steve
Published: October 2009

This article considers specific elements of the project management of high-value deliverables in an under-researched sector. Specifically, it looks at ways in which change is accommodated in complex projects where scope, delivery, and cost are relatively inflexible. An emerging literature considers improvisational working within project-based work, which dilutes the “plan, then execute” paradigm that has shaped project work for some time. This research contributes to the temporal and rhythmic aspects of work in this area, linking with extant theory on, among other areas, punctuated equilibrium and organizational “rhythm,” and identifies parallels between improvised project work and established academic theory.
Hydrazine‐functionalized latexes
Authors: Costoyas Álvaro , Ramos Jose , Forcada Jacqueline
Published: October 2009

The noncommercial functional monomer 4‐vinylbenzyl hydrazine (VBH) was synthesized and subsequently copolymerized with styrene (St) by means of different batch and semicontinuous seeded emulsion polymerization processes, so as to obtain hydrazine‐functionalized nanoparticles. The effect of pH, surfactant and initiator amounts, ratio VBH/St, reaction temperature, and ratio acetone/water were studied. Due to the amphiphilic character of VBH at acid pH, the hydrazine groups of the functionalized comonomer were masked with acetone to form hydrazone groups. Secondary nucleations were avoided by using the protected VBH comonomer; however, a decreased radical efficiency achieving limited conversion was observed. Controlling the cationic initiator concentration, complete conversions together with the neat growth of the seed particles were obtained in the semicontinuous seeded emulsion polymerization of styrene and VBH protected with acetone. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6201–6213, 2009
Synthesis and characterization of photosensitive benzocyclobutene‐functionalized siloxane thermosets
Authors: Zuo Xiaobiao , Yu Ruilian , Shi Song , Feng Zhihai , Li Zhongping , Yang Shiyong , Fan Lin
Published: October 2009

Two methylphenylsiloxane monomers with crosslinkable benzocyclobutene functionalities at the terminal positions, 1,1,5,5‐dimethyldiphenyl‐1,1,5,5‐di[2′‐(4′‐benzocyclobutenyl)vinyl]‐3,3‐diphenyltrisiloxane (BCB‐1) and 1,1,3,3‐dimethyl‐diphenyl‐1,1,3,3‐di[2′‐(4′‐benzocyclobutenyl)vinyl]disiloxane (BCB‐2) were prepared and characterized. By heating the solution of BCB‐1 and BCB‐2 in mesitylene, two partially polymerized resins of BCB‐1B and BCB‐2B with high molecular weight were also achieved. The monomers and their oligomers fully cured at temperatures above 250 °C. Cured BCB‐1 and BCB‐2 exhibited high Tg (257 and 383 °C) and good thermal stability (T5% > 472 °C both in N2 and in air). They also demonstrated low dielectric constants (2.69 and 2.66), low dissipation factors (2.36 and 2.23), and low water absorptions (0.20% and 0.17%). Moreover, a negative photosensitive formulation derived from BCB‐1B in combination with 2,6‐bis(4‐azidobenzylidene)‐4‐methylcyclohexanone (BAC‐M) as a photosensitive agent has been developed. The photosensitive composition, BCB‐1B containing 5 wt % BAC‐M, showed a sensitivity of 550 mJ/cm2 and a contrast of 1.96 when it was exposed to a 365 nm light (i‐line) and developed with cyclohexanone at 25 °C. A fine negative image of 10 μm line‐and‐space pattern was also printed in a film which was exposed to 700 mJ/cm2 of i‐line by contact‐printing mode. The negative image can be maintained without any pattern deformation in the curing process. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6246–6258, 2009
Synthesis of novel fluorinated hyperbranched polyimides with excellent optical properties
Authors: Liu Yu , Zhang Yunhe , Guan Shaowei , Zhang Haibo , Yue Xigui , Jiang Zhenhua
Published: October 2009

Novel anhydride‐terminated fluorinated hyperbranched polyimides (FHBPIs) were successfully prepared by condensation of a triamine monomer, 1,3,5‐tris(2‐trifluoromethyl‐4‐aminopheoxy) benzene (TFAPOB), and various aromatic dianhydride monomers with different linear length. UV–vis spectra indicate high optical transparency of FHBPI films with a UV–vis absorption edge of 350–395 nm. FHBPIs show increased mechanical properties with the linear length of dianhydride monomer. Young's moduli of FHBPI range from 2.37 to 2.56 Gpa, similar to those of their linear analogs. These FHBPI films also present a minimum birefringence value as low as 0.0025 at 650 nm and have low optical absorption in the optical communication wavelengths of 1310 and 1550 nm. Rib‐type optical waveguide device fabricated by FHBPI‐4d demonstrated an obvious near‐field mode pattern of the waveguide. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6269–6279, 2009
Nonisothermal melt crystallization and subsequent melting behavior of biodegradable poly(hydroxybutyrate)/multiwalled carbon nanotubes nanocomposites
Authors: Xu Changling , Qiu Zhaobin
Published: October 2009

In this work, nonisothermal melt crystallization and subsequent melting behavior of poly(hydroxybutyrate) (PHB) and its nanocomposites at different multiwalled carbon nanotubes (MWCNTs) loadings were investigated. Increasing the MWCNTs loadings has enhanced the nonisothermal melt crystallization of PHB significantly in the nanocomposites when compared with that of the neat PHB; furthermore, increasing the cooling rates shift the crystallization exotherms to low temperature range for both neat PHB and its nanocomposites. Double melting behavior is found for both neat PHB and its nanocomposites crystallized nonisothermally from the melt, which is explained by the melting, recrystallization, and remelting model. Effects of the MWCNTs loadings, cooling rates, and heating rates on the subsequent melting behavior of PHB were studied in detail. It is found that increasing the MWCNTs loadings, decreasing the cooling rates, and increasing the heating rates would restrict the occurrence of the recrystallization of PHB in the nanocomposites. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2238–2246, 2009
Structure versus properties relationship of poly(lactic acid). I. Effect of crystallinity on barrier properties
Authors: Drieskens Marjoleine , Peeters Roos , Mullens Jules , Franco Dirk , Lemstra Pieter J. , Hristova‐Bogaerds Denka G.
Published: October 2009

Poly(lactic acid) is at present the most promising and commercially available bio‐based and biocompostable (bio)plastic. The properties of PLA, however, are rather poor, notably its low glass transition temperature Tg of ∼55 °C, its intrinsic low crystallization rate and the limited barrier properties with respect to water, oxygen and carbon dioxide in comparison with to oil‐based counterparts, notably polyesters (PET). In this manuscript we address the question of what could ultimately be achieved in terms of barrier properties when PLA is crystallized fully. In fact, this question is rather academic in view of the long crystallization/annealing times needed to obtain maximum crystallinity but serves the purpose of better understanding current limits and notably a better understanding of the role of crystallinity on the barrier properties. A correlation is made between crystallization, various morphological parameters and the barrier properties of PLA. Crystallization of PLA causes a decrease of the oxygen permeability, but not in linear proportion with the decrease in amorphous volume. We explain this in terms of influence of the space filling and the inner crystalline structure on gas transport properties. Furthermore we suggest that the presence of a rigid amorphous fraction with lower density can have strong impact on PLA gas permeability, in particular on the gas solubility coefficient of PLA. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2247–2258, 2009
Dielectric relaxations of chitosan: The effect of water on the α‐relaxation and the glass transition temperature
Authors: González‐Campos J. Betzabe , Prokhorov Evgen , Luna‐Bárcenas Gabriel , Fonseca‐García Abril , Sanchez Isaac C.
Published: October 2009

In this work thermal relaxations of chitosan are reported by using a novel methodology that includes subtraction of the dc conductivity contribution, the exclusion of contact and interfacial polarization effects, and obtaining a condition of minimum moisture content. When all these aspects are taken into account, two relaxations are clearly revealed in the low frequency side of the impedance data. We focus on the molecular motions in neutralized and non‐neutralized chitosan analyzed by dielectric spectroscopy in the temperature range from 25 to 250 °C. Low and high frequency relaxations were fitted with the Havriliak and Negami model in the 10−1 to 108 Hz frequency range. For the first time, the low frequency α‐relaxation associated with the glass‐rubber transition has been detected by this technique in both chitosan forms for moisture contents in the range 0.05 to 3 wt % (ca. 18–62 °C). A strong plasticizing effect of water on this primary α‐relaxation is observed by dielectric spectroscopy and is supported by dynamic mechanical analysis measurements. In the absence of water (<0.05 wt %) the α‐relaxation is obscured in the 20–70 °C temperature range by a superposition of two low frequency relaxation processes. The activation energy for the σ‐relaxation is about 80.0–89.0 kJ/mol and for β‐relaxation is about 46.0–48.5 kJ/mol and those values are in agreement with that previously reported by other authors. The non‐neutralized chitosan possess higher ion mobility than the neutralized one as determined by the frequency location of the σ‐relaxation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2259–2271, 2009
Predicting protein complex geometries with a neural network
Authors: Chae Myong‐Ho , Krull Florian , Lorenzen Stephan , Knapp Ernst‐Walter
Published: October 2009

A major challenge of the protein docking problem is to define scoring functions that can distinguish near‐native protein complex geometries from a large number of non‐native geometries (decoys) generated with noncomplexed protein structures (unbound docking). In this study, we have constructed a neural network that employs the information from atom‐pair distance distributions of a large number of decoys to predict protein complex geometries. We found that docking prediction can be significantly improved using two different types of polar hydrogen atoms. To train the neural network, 2000 near‐native decoys of even distance distribution were used for each of the 185 considered protein complexes. The neural network normalizes the information from different protein complexes using an additional protein complex identity input neuron for each complex. The parameters of the neural network were determined such that they mimic a scoring funnel in the neighborhood of the native complex structure. The neural network approach avoids the reference state problem, which occurs in deriving knowledge‐based energy functions for scoring. We show that a distance‐dependent atom pair potential performs much better than a simple atom‐pair contact potential. We have compared the performance of our scoring function with other empirical and knowledge‐based scoring functions such as ZDOCK 3.0, ZRANK, ITScore‐PP, EMPIRE, and RosettaDock. In spite of the simplicity of the method and its functional form, our neural network‐based scoring function achieves a reasonable performance in rigid‐body unbound docking of proteins. Proteins 2010. © 2009 Wiley‐Liss, Inc.
A review of demographic ageing in the UK: opportunities for rural research
Authors: Stockdale Aileen
Published: October 2009

Demographic ageing is a global phenomenon. UK policy and research have, until recently, focused on national trends and implications and largely viewed ageing as a ‘pensions and care’ problem. While other and more positive aspects are beginning to be acknowledged, regional, local, and rural impacts remain underinvestigated. This paper, by reviewing the literature from several disciplines and countries, introduces a series of research questions that could usefully inform future geographical inquiry. It argues that the nature, experiences, and consequences of demographic ageing will vary across space, stage in the life course and numerous aspects of our everyday lives. Our current knowledge and understanding are but the tip of the iceberg in terms of the research opportunities that lie ahead. Copyright © 2009 John Wiley & Sons, Ltd.
Paul trap for pure positron plasma – A prelude to electron–positron plasma in a laboratory
Authors: Bajpai M. , Lachhvani L. T. , Saxena Y. C.
Published: October 2009

A scheme to construct a Paul Trap to trap positrons and create ‘Pure Positron Plasma’ has been presented. Positrons from a sealed source (22Na) are moderated down to ∼ 2.5 eV with an energy spread of ≤1 eV with a pre‐treated 1 μm Tungsten moderator held at room temperature with a moderation efficiency ∼ 6 × 10–4 – 2 × 10–3. The energy of moderated positrons is further adjusted to about 42 eV by biasing the moderator before their entry in to the trap. Positrons entering the trap are cooled by a buffer gas (inelastic collisions with N2 or CO2) at low pressure, hence fall in the pseudo‐potential well. This trap will additionally be used as a test bed for future systems with the ability of confining both positrons and electrons simultaneously and to create electron‐positron plasma. In this paper, the physics design and estimations such as, the order of vacuum, geometry, stability parameters a, q (and hence RF voltage and frequency), pseudo‐potential well depths (Dρ, Dz) and space charge limited density of trapped positrons have been discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ionization of positronium (Ps) in collision with atom
Authors: Ray Hasi
Published: October 2009

The theoretical studies on ionization of positronium (Ps) and the phenomenon of exchange are of fundamental interests. Again the singly energy differetial cross section (SDCS) is more informative than the total ionization cross section (TCS). We present a brief comparativestudy on TCS and SDCS for Ps‐ionization in Ps‐H and Ps‐He collision to provide a very basic knowledge about the system (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron annihilation studies on the nature and thermal behaviour of irradiation induced defects in tungsten
Authors: Lhuillier P. E. , Barthe M. F. , Desgardin P. , Egger W. , Sperr P.
Published: October 2009

Positron Annihilation Lifetime Spectroscopy has been performed with a pulsed positron beam to investigate the nature and evolution of implantation‐induced defects created in the track region (TR) of 800 keV 3He ions at different fluences. At high fluence ‐ 5×1016 cm–2 ‐ lifetime decomposition exhibits a predominant (98%) positron lifetime of 200 ps which is attributed to irradiation induced monovacancy. The increasing average lifetime as a function of the post‐implantation annealing temperature has allowed to identify vacancy clustering due to vacancy migration (that occurs from 473 K). (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wide‐band phase locking of Josephson junctions in a resonator
Authors: Grib Alexander , Seidel Paul
Published: October 2009

We found that the chain of junctions acts both as the source of radiation and as a part of the superconducting resonator when the effective capacitance of the resonator is larger than the total capacitance of all junctions. At this condition junctions are synchronized in‐phase not only at the resonance steps but also in the whole hysteretic region of I –V characteristics below the resonant frequency. The maximal allowable spread of critical currents for this effect is about 5–10%. We analyzed the origin of the effect both numerically and by the method of slowly varying amplitudes.

magnified image

(© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal structure of the atmospheric boundary layer on Mars based on Mini‐TES observations
Authors: Sorbjan Zbigniew , Wolff Michael , Smith Michael D.
Published: October 2009

This paper presents and discusses the vertical profiles of the potential temperature in the Martian boundary layer. The profiles were remotely sensed from on‐board the Spirit Mars Exploration Rover during the first 702 sols of its operation in 2004–2005. The rover carried the Miniature Thermal Emission Spectrometer (Mini‐TES), which allowed it to retrieve temperature profiles up to a level 2 km above the ground surface. The data analysed here permit a reconstruction of the diurnal and seasonal structure of the lower part of the Martian convective boundary layer, an evaluation of the boundary layer depth, and a computation of the temperature heat flux. Copyright © 2009 Royal Meteorological Society
Facile Synthesis of Macrocellular Mesoporous Foamlike Ce–Sn Mixed Oxides with a Nanocrystalline Framework by Using Triblock Copolymer as the Single Template
Authors: Li Le‐Le , Xu Jun , Yuan Quan , Li Zhen‐Xing , Song Wei‐Guo , Yan Chun‐Hua
Published: October 2009

Macrocellular mesoporous foamlike cerium–tin mixed oxide materials with well‐defined porous structure and nanocrystalline frameworks are synthesized through a simple one‐step self‐assembly process using an amphiphilic triblock copolymer as the single template. The macrocellular pores are synthesized without the addition of any swelling agent or hazardous acids. The final mixed oxide possesses a hierarchically porous structure including macrocellular foam with ultralarge cell size, closed windows, and mesopores on the walls. This indicates that the porous structure can be notably stabilized and improved by the incorporation of Sn in the CeO2. The materials are expected to be good candidates in catalysis, since the hierarchical porosity enables high surface areas and hence more chemically active sites associated with the mesopores, combined with the high efficiency of mass transport from the macrocellular foam. The catalytic characteristics are discussed in relation to the architectures of the materials, and it is revealed that the macrocellular/mesoporous materials would be an efficient catalyst for CO oxidation.
Focusing Plasmons in Nanoslits for Surface‐Enhanced Raman Scattering
Authors: Chen Chang , Hutchison James Andell , Van Dorpe Pol , Kox Ronald , De Vlaminck Iwijn , Uji‐i Hiroshi , Hofkens Johan , Lagae Liesbet , Maes Guido , Borghs Gustaaf
Published: October 2009

The focusing of plasmons to obtain a strong and localized electromagnetic‐field enhancement for surface‐enhanced Raman scattering (SERS) is increasing the interest in using plasmonic devices as molecular sensors. In this Full Paper, we report the successful fabrication and demonstration of a solid‐state plasmonic nanoslit–cavity device equipped with nanoantennas on a freestanding thin silicon membrane as a substrate for SERS. Numerical calculations predict a strong and spatially localized enhancement of the optical field in the nanoslit (6 nm in width) upon irradiation. The predicted enhancement factor of SERS was 5.3 × 105, localized in an area of just 6 × 1.5 nm2. Raman spectroscopy and imaging confirm an enhancement factor of ≈106 for SERS from molecules chemisorbed at the nanoslit, and demonstrate the electromagnetic‐field‐enhancing function of the plasmonic nanoantennas. The freestanding membrane is open on both sides of the nanoslit, offering the potential for through‐slit molecular translocation studies, and opening bright new perspectives for SERS applications in real‐time (bio)chemical analysis.
Neubau der ÖBB‐Donaubrücke Tulln – ein innovatives Brückentragwerk
Authors: Dorrer Günther
Published: October 2009

104 Jahre nach ihrer Erbauung wurde die Eisenbahnbrücke der Österreichischen Bundesbahnen (ÖBB) über die Donau in Tulln einer Generalsanierung unterzogen. Als Tragsystem der neuen Brücke wurde eine Fachwerkverbundkonstruktion mit untenliegender Fahrbahn gewählt. Nach nur 16 Monaten Bauzeit konnte mit der Inbetriebnahme im Oktober 2009 ein Stück europäische Brückenbaugeschichte geschrieben werden. Für die Demontage der bestehenden Tragwerke und die Montage des neuen Tragwerks inklusive der Ausrüstung für den Bahnbetrieb stand eine 7‐monatige Streckensperre zur Verfügung. Die Herstellung des Ersatzneubaus des 440 m langen Brückentragwerks unter möglichst geringer Beeinträchtigung des Straßen‐, Bahn‐ und Schiffsverkehrs stellte höchste Anforderungen an den Bauherrn, die Planer und die ARGE Donaubrücke Tulln.

Errection of the ÖBB‐Donaubrücke Tulln – an innovative bridge construction.

104 years after being built, the railway bridge of the Österreichischen Bundesbahnen (ÖBB) across the Danube at Tulln, Austria, has been completely refurbished. The new bridge is based on a composite over‐deck truss construction. After a construction time of only 16 months, commissioning in October 2009 was the last step in a project that will make European bridge construction history. For the dismantling of the existing supporting structure and the assembly of the new one incl. the railway facilities, the railway line was blocked for 7 months. Replacing the 400‐m long supporting structure while keeping the effects on road, rail and shipping traffic to the lowest possible level put highest demands on owner, planners and ARGE Donaubrücke Tulln.
Ein “Overall‐Konzept” für die Querschnittstragfähigkeit im elasto‐plastischen Bereich
Authors: Kettler Markus , Greiner Richard
Published: October 2009

Es wird die bereits für andere Tragfähigkeitsprobleme von Bauteilen (Knicken, Beulen) entwickelte “Overall‐Methode” auf die Berechnung der Querschnittstragfähigkeit von Stahlprofilen angewendet. Dies führt zu einer neuen Berechnungsmethode, die den gesamten elasto‐plastischen Bereich ohne die Notwendigkeit einer Klasseneinteilung umfasst. Basierend auf zahlreichen Versuchen und Querschnittsberechnungen mittels geometrisch, materiell nichtlinearer Analysen mit Imperfektionen werden (analog den Knicklinien) Bemessungskurven für die Abminderungsfaktoren vorgeschlagen, die für bestimmte Querschnittstypen wie I‐beziehungsweise H‐Profile oder Rechteck‐Hohlprofile, einen einheitlichen Verlauf im elasto‐plastischen Bereich aufweisen.

An overall concept for the cross‐section resistance in the elasto‐plastic range.

The “overall method” which has been developed for other load carrying problems of steel members (e.g. lateral member buckling or buckling of shells) is applied to the calculation of the cross‐section resistance of steel members. This leads to a new procedure that covers the whole elasto‐plastic range without the need of cross‐section classification. Based on numerous experimental tests and numerical calculations (GMNIA) design curves for the reduction factors of I‐ and H‐shaped sections and RHS‐sections are proposed that show a consistent transition in the elasto‐plastic range.
Biegeknicken und Biegedrillknicken aus der Haupttragebene
Authors: Feldmann Markus , Naumes Johannes , Sedlacek Gerhard
Published: October 2009

Während im Eurocode 3 die Regeln für das Biegeknicken europäisch einheitlich sind, gibt es für die Regeln für das Biegedrillknicken eine Reihe von alternativen Vorschlägen, die von verschiedenen Autoren stammen, nicht konsistent sind und daher durch Öffnungsklauseln national entschieden werden können. In diesem Beitrag wird gezeigt, dass Biegeknicken und Biegedrillknicken eine gemeinsame mechanische Grundlage haben, die durch eine für beide Phänomene geltende Imperfektionsannahme und darauf aufbauend durch gleich formulierte Biegeknick‐ und Biegedrillknickkurven beschrieben werden kann. Damit entsteht ein in sich konsistentes klares und einfaches Nachweisverfahren, das durch Kalibration an Versuchsergebnissen nach EN 1990 zuverlässigkeitsmäßig überprüft wurde und in das Sicherheitssystem der Eurocodes passt. Das Verfahren eignet sich für numerische Verfahren und Handberechnungen und ermöglicht auch in einfacher Weise die Berücksichtigung von zusätzlicher Biege‐ und Torsionsbelastung in Biegeknick‐ und Biegedrillknickrichtung.

Flexural buckling and lateral torsional buckling out of the main plane.

Whereas design rules for flexural buckling in Eurocode 3 based on buckling curves are common for Europe, the design rules for lateral torsional buckling are not; there are various alternative proposals originating from various authors which are not consistent and therefore have been made subject to National decisions by opening notes. This paper demonstrates that flexural buckling and lateral torsional buckling have a common mechanical basis resulting in a single formula for equivalent geometrical imperfections and also in a single formula for flexural and lateral torsional buckling curves derived from these imperfections. In conclusion a consistent, clear and simple method for flexural and lateral torsional buckling assessment is obtained, the reliability of which could be proved to be in conformity with the safety requirement of the Eurocodes by test evaluations according to EN 1990. The method is applicable for numerical assessments (e.g. FEM) as well as for hand calculations and also allows to take additional loading in bending and torsion into account.
Generation of Parthenogenetic Induced Pluripotent Stem Cells from Parthenogenetic Neural Stem Cells
Authors: Do Jeong Tae , Joo Jin Young , Han Dong Wook , Araúzo-Bravo Marcos J. , Kim Min Jung , Greber Boris , Zaehres Holm , Sobek-Klocke Ingeborg , Chung Hyung Min , Schöler Hans R.
Published: October 2009

Somatic cells can achieve a pluripotent cell state in a process called pluripotential reprogramming. Multipotent stem cells can differentiate into cells of only one lineage, but pluripotent stem cells can give rise to cells of all three germ layers of an organism. In this study, we generated induced pluripotent stem (iPS) cells from bimaternal (uniparental) parthenogenetic neural stem cells (pNSCs) by transduction with either four (4F: Oct4, Klf4, Sox2, and c-Myc) or two (2F: Oct4 and Klf4) transcription factors. The resultant maternal iPS cells, which were reprogrammed directly from pNSCs, were capable of generating germ line-competent chimeras. Interestingly, analysis of global gene expression and imprinting status revealed that parthenogenetic iPS cells clustered closer to parthenogenetic ESCs than to female ESCs, with patterns that were clearly distinct from those of pNSCs.

Disclosure of potential conflicts of interest is found at the end of this article.
CD133 Expression Defines a Tumor Initiating Cell Population in Primary Human Ovarian Cancer
Authors: Curley Michael D. , Therrien Vanessa A. , Cummings Christine L. , Sergent Petra A. , Koulouris Carolyn R. , Friel Anne M. , Roberts Drucilla J. , Seiden Michael V. , Scadden David T. , Rueda Bo R. , Foster Rosemary
Published: October 2009

Evidence is accumulating that solid tumors contain a rare phenotypically distinct population of cells, termed cancer stem cells (CSC), which give rise to and maintain the bulk of the tumor. These CSC are thought to be resistant to current chemotherapeutic strategies due to their intrinsic stem-like properties and thus may provide the principal driving force behind recurrent tumor growth. Given the high frequency of recurrent metastasis associated with human ovarian cancer, we sought to determine whether primary human ovarian tumors contain populations of cells with enhanced tumor-initiating capacity, a characteristic of CSC. Using an in vivo serial transplantation model, we show that primary uncultured human ovarian tumors can be reliably propagated in NOD/SCID mice, generating heterogeneous tumors that maintain the histological integrity of the parental tumor. The observed frequency of tumor engraftment suggests only certain subpopulations of ovarian tumor cells have the capacity to recapitulate tumor growth. Further profiling of human ovarian tumors for expression of candidate CSC surface markers indicated consistent expression of CD133. To determine whether CD133 expression could define a tumor-initiating cell population in primary human ovarian tumors, fluorescence-activated cell sorting (FACS) methods were employed. Injection of sorted CD133+ and CD133− cell populations into NOD/SCID mice established that tumor-derived CD133+ cells have an increased tumorigenic capacity and are capable of recapitulating the original heterogeneous tumor. Our data indicate that CD133 expression defines a NOD/SCID tumor initiating subpopulation of cells in human ovarian cancer that may be an important target for new chemotherapeutic strategies aimed at eliminating ovarian cancer.

Disclosure of potential conflicts of interest is found at the end of this article.
QoS aware dynamic route optimization for Proxy Mobile IPv6 networks
Authors: Pragad A. Dev , Friderikos Vasilis , Pangalos Paul , Aghvami A. Hamid
Published: October 2009

Proxy Mobile IPv6 is a network based mobility management solution and was proposed to address the shortcomings of the existing set of mobility management protocols. The presence of local mobility anchors (LMA) in PMIPv6 networks can lead constrained routing and create areas of bottleneck. This is due to all traffic to the mobile nodes (MNs) in the PMIPv6 domain having to flow to and from the LMA. Future IP networks will support a wide variety of sessions ranging for high QoS Video conferencing to FTP and P2P download. Providing the same level of mobility support for all of these sessions can lead to the resources of LMA being drained. To avoid this, we propose the QoS aware Dynamic Route Optimization scheme where the network identifies the lower QoS sessions and establishes a binding update with the correspondant node (CN) rather than with the LMA. To achieve this a flow based binding approach is followed. The level of congestion in the network is also considered as part of the mechanism. To ensure optimal performance of the proposed mechanism, routing policies are proposed. Simulation results show considerable benefit to the network in terms of reduction in blocking probability as well as reduction in tunnelling overhead cost in comparisons to no route optimization (RO) and adaptive route optimization (ARO) being deployed in the PMIPv6 networks. Copyright © 2009 John Wiley & Sons, Ltd.
Studies on the coherence bandwidth of high‐frequency vehicular communication system with antenna array
Authors: Li Yanli , Duan Xiaohui , Ma Meng , Jiao Bingli
Published: October 2009

High‐frequency (HF) vehicular communication system works with the frequency‐selective fading channel, thereby the coherence bandwidth is limited due to the multipath time dispersive effect, which imposes the difficulty for achieving the high‐data rate transmission. The present paper investigates the antenna array technique for its ability in reducing the multipath delay spread of the ionosphere channel and, thus, increasing possibly the bandwidth of the HF system. To enable fast moving speed of the vehicular receiver, we propose to use single antenna at the receiver and the adaptive array at the transmitter. The adaptive beamforming is driven based on the protocol design and reciprocity principle of channel. In order to evaluate the performance of array system, a statistical HF double‐directional channel model, which includes angular information at both the transmitter and receiver, is presented. The explicit expressions are obtained for calculating the coherence bandwidth. The numerical results show the efficiency of this approach for mid‐latitude mid‐range channel. Copyright © 2009 John Wiley & Sons, Ltd.
Ce2Pt8P: A Phosphido‐platinide with Covalently Bonded Framework Polyanion
Authors: Chizhov Pavel S. , Prots Yurii , Antipov Evgeny V. , Grin Yuri
Published: October 2009

The cerium phosphido‐platinide Ce2Pt8P is synthesized by direct reaction of the elements. The crystal structure is considered as an intergrowth of structural segments with the compositions CePt5 (CaCu5‐like) and CePt3P (CePt3B‐like) along [010]. The Pt–Pt and Pt–P distances in the anionic framework are close to the ones found in CePt5 and CePt4P2. Analysis of the chemical bonding in real space reveals the presence of a Pt–P covalently‐bonded polyanion [Pt8P] (consisting of PtPt6 trigonal prisms and PPt5 tetragonal pyramids). Cerium cations are located in the voids of the polyanionic framework. Together with CePt5 (m = 0, n = 1), Ce2Pt8P (m = 1, n = 1) forms a homological series Cen+mPt5n+3mPm. The hypothetical “CePt3P” (m = 1, n = 0) with CePt3B‐type crystal structure is not known to date.
Silicon Encapsulated Carbon Nanotubes
Authors: Katar SriLakshmi , Labiosa AzlinBiaggi , Plaud Amairy E , Mosquera-Vargas Edgar , Fonseca Luis , Weiner Brad R , Morell Gerardo
Published: October 2009

A dual stage process of depositing bamboo-like carbon nanotubes (BCNTs) by hot filament chemical vapor deposition (HFCVD) and coating Si using Radio frequency sputtering (RFS) technique. The films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron field emission studies (EFE). SEM results suggest a dense network of homogeneous silicon-coated BCNTs. From the comprehensive analysis of the results provided by these techniques emerges the picture of Si encapsulated BCNTs.