bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of LMX‐1A as a metastasis suppressor in cervical cancer
Authors: Liu Chin‐Yu , Chao Tai‐Kuang , Su Po‐Hsuan , Lee Hsin‐Yi , Shih Yu‐Lueng , Su Her‐Young , Chu Tang‐Yuan , Yu Mu‐Hsien , Lin Ya‐Wen , Lai Hung‐Cheng
Published: June 2009

DNA methylation is important in cancer development and is a promising biomarker for cancer detection. An epigenomic approach used in our previous work showed that LMX‐1A is methylation‐silenced in cervical cancer. LMX‐1A, a LIM‐homeobox gene, is known to participate in developmental events; however, there are at present no data on the role of LMX‐1A in cancers. In this study, we characterized the function of this transcription factor by examining cell lines, animal models and human cervical neoplastic tissues, and found that over‐expression of LMX‐1A does not affect cell proliferation or the cell cycle of cervical cancer cell lines but significantly inhibits colony formation and invasion in vitro. Analysis of changes in epithelial–mesenchymal transition (EMT) markers, such as CDH1, CDH2, VIMENTIN, SNAIL, SLUG and TWIST, revealed involvement of the EMT in LMX‐1A‐mediated cancer invasion; this result was validated in a stable transfectant over‐expressing LMX‐1A with RNA interference. Xenograft studies using immunocompromised mice confirmed the suppressor effects of LMX‐1A on tumour formation and distant metastasis in cervical cancer cell lines. LMX‐1A immunohistochemical staining of tissue arrays containing the full spectrum of cervical neoplasms, including normal cervix, low‐grade cervical intra‐epithelial neoplasia (CIN), high‐grade CIN, locally invasive and distant metastatic cancers, demonstrated the critical role of LMX‐1A in invasion and metastasis. Furthermore, we found by analysing TGFβ–BMP signalling that BMP4 and BMP6 are down‐regulated by LMX‐1A. The results of this study suggest that LMX‐1A suppresses cancer invasion and metastasis in cervical cancer through an incomplete EMT. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Direct analysis of curcumin in turmeric by DART‐MS
Authors: Kim Hye Jin , Jang Young Pyo
Published: June 2009

Introduction

The new ion source technique, direct analysis in real time (DART) atmospheric pressure ionisation, allows high resolution mass measurements of gas, liquid and solid samples. As DART‐MS produces [M + H]+ molecular ions of most compounds, relatively simple and clear mass spectra are obtained even of multi‐component samples. In order to take advantage of the capacity of DART‐MS for the real time analysis of individual compounds in natural raw materials, a pilot study was performed using the well‐known antioxidant botanical drug, turmeric.

Objective

To establish the analysis methods of curcumin and its derivatives from various types of samples with DART‐MS and compare the efficiency of the method with traditional HPLC method.

Results

Different curcuminoids were successfully detected directly from the raw particles of Curcuma longa. When a turmeric extract was separated on a TLC plate, each band produced molecular ion peaks corresponding to curcumin, demethoxycurcumin and bisdemethoxycurcumin. Molecular ions of curcuminoids in turmeric‐containing beverages and curry powder were also efficiently detected. In addition to high efficiency of qualitative analysis, the evaluation of its linearity showed that DART‐MS can be applied for semi‐quantitative determinations of curcumin over a large range (5–100 µg/mL).

Conclusion

A simple chemical profiling and semi‐quantitative method for natural products using DART‐MS might be applied to diverse field related quality control of medicinal plants or food ingredients. Copyright © 2009 John Wiley & Sons, Ltd.
Aqueous self‐condensing atom transfer radical copolymerization of a water‐soluble inimer with cationic comonomer to prepare hyperbranched cationic polyelectrolytes
Authors: Gao Jun , Kong Lizhi , Wang Cui , Zhai Guangqun , Ren Qiang , Jiang Bibiao
Published: June 2009

BACKGROUND: Although several methods have been reported for the preparation of hyperbranched cationic polyelectrolytes (HCPs), their applicability is limited. A convenient, facile strategy based on atom transfer radical polymerization (ATRP) of N,N‐dimethyl‐N‐(2‐methacryloyloxy)ethyl(2‐bromoisobutyryloxy)ethylammonium bromide (DMEAB) with N,N‐dimethyl‐N‐ethyl‐N‐methacryloyloxyethylammonium bromide (DEMAB) is therefore proposed to prepare their hyperbranched copolymer (PDEMAB).

RESULTS: NMR spectroscopy was used to confirm the hyperbranched architecture and to estimate the number‐average degree of polymerization (DPn) of the hyperbranched PDEMAB. A kinetic study showed that DPn of the hyperbranched PDEMAB increased very slowly in the initial stage, but increased in an exponential manner during the later phase. When a lower [DEMAB]:[DMEAB] ratio was used, DPn increased much faster than when a higher ratio was used. The CuBr/2,2′‐bipyridine complex showed good catalytic activity while FeCl2/aliphatic multi‐amine complexes led to crosslinking. For the viscometry of the aqueous solution, although c1/2 − (ηsp/c)−1 fitted well, the Füoss equation might not be applicable for HCPs. A rheological study showed that the HCPs exhibited an extremely low viscosifying effect, in contrast to their linear analogues.

CONCLUSION: The aqueous self‐condensing ATRP of DMEAB with DEMAB (and other counterparts) readily led to HCPs. Such a strategy could also be extended to other monomers such as vinylpyridine and vinylimidazole. Copyright © 2009 Society of Chemical Industry
Rondine® PV concentrators: Field results and developments
Authors: Antonini A. , Butturi M. A. , Di Benedetto P. , Uderzo D. , Zurru P. , Milan E. , Stefancich M. , Armani M. , Parretta A. , Baggio N.
Published: June 2009

In this work the experimental results of a new PV concentrator (named Rondine®) are presented. This concentrating module has a medium concentration level (∼25×) and employs silicon solar cells. The tests have been carried out in Italy and the energy production of a prototype module is compared with that produced from a tracking flat plate crystalline PV panel. The non‐imaging optics of the concentrator allows for larger angular acceptance with respect to many solar concentrators, giving us the possibility to employ trackers for standard PV modules. The first results of complete systems of 3·9 and 4·8 kW of peak power installed in summer 2008 are presented here. Copyright © 2009 John Wiley & Sons, Ltd.
5% Efficient evaporated solid‐phase crystallised polycrystalline silicon thin‐film solar cells
Authors: Kunz O. , Ouyang Z. , Varlamov S. , Aberle A. G.
Published: June 2009

The first energy conversion efficiencies of over 5% are reported for evaporated solid‐phase crystallised (SPC) polycrystalline silicon thin‐film solar cells. All cells have a size of 2 cm2 and are formed on planar glass superstrates. Back surface reflectance is provided by a simple coating with commercial white paint. The best cells have short‐circuit current densities of about 19 mA/cm2 and external quantum efficiencies peaking at above 80%. The diffusion length in the base of the solar cells is larger than the base thickness, providing significant room for further efficiency improvements via an increased thickness of the base layer. Additional improvements are expected via the use of textured glass sheets, boosting the light trapping capabilities of the cells. Copyright © 2009 John Wiley & Sons, Ltd.
Positive Ion Mass Spectrometry during an Atmospheric Pressure Plasma Treatment of Polymers
Authors: Beck Alison J. , Aranda Gonzalvo Yolanda , Pilkington Antony , Yerokhin Aleksey , Matthews Allan
Published: June 2009

A low power atmospheric pressure helium plasma torch was used to modify the surface chemistry of poly(α‐methylstyrene), polystyrene, poly(propylene) and polyethylene. Mass spectra of the positive ions present in the plasma during the treatment revealed dominant ions with structures that reflected the structure of the polymer, e.g. C6H5CnH2n containing a phenyl group in the aromatic polymers and hydrocarbon structures CnH2n ± 1 up to n = 14 for poly(propylene). Ions up to m/z 300 were detected. X‐ray photoelectron spectroscopy showed that this treatment introduced oxygen‐containing functional groups into the surface of the polymers.

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Fundamental and Innovations in Plasma Assisted Diffusion of Nitrogen and Carbon in Austenitic Stainless Steels and Related Alloys
Authors: Czerwiec Thierry , He Huan , Marcos Grégory , Thiriet Tony , Weber Sylvain , Michel Henri
Published: June 2009

An improvement of the surface properties of austenitic stainless steels and nickel‐based alloys is obtained by low temperature plasma assisted nitriding (PAN), plasma assisted carburizing (PAC) and plasma assisted nitrocarburizing (PANC). At low temperature, PAN treatment produces a peculiar phase usually called expanded austenite, S phase, m phase or γN phase. Replacing nitrogen by hydrocarbon for conducting a low temperature PAC gives a carburized layer containing the carbon expanded austenite phase (γC). These two phases can simultaneously be obtained by combining hydrocarbon and nitrogen in the gas phase through a low temperature PANC. Several fundamental aspects concerning the expanded austenite phases are presented in this paper.

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Effect of High Ion Irradiation on the Structure, Properties and High Temperature Tribology of Nanoscale CrAlYN/CrN Multilayer Coating Deposited by HIPIMS‐HIPIMS Technique
Authors: Hovsepian Papken Eh. , Ehiasarian Arutiun P. , Purandare Yashodhan P. , Braun Reinhold , Ross Ian M.
Published: June 2009

The high degree of ionisation of the sputtered particles in High power impulse magnetron sputtering (HIPIMS) discharge was utilised to deposit very dense nanoscale multilayer CrAlYN/CrN coatings. These newly developed coatings are designed to meet the demands for high oxidation and wear resistant coatings of light weight materials such as γ‐TiAl alloys for future applications in aerospace and automotive engines. The coatings were produced by a HIPIMS‐HIPIMS methodology in which HIPIMS was employed for adhesion enhancement surface pre‐treatment as well as for coating deposition in combination with standard unbalanced magnetron sputtering (UBM). TEM studies revealed extremely sharp interfaces between the individual layers in the nanolaminated material and almost no layer waviness. The coatings exhibited low friction and wear coefficients (Kc) at ambient and elevated temperatures of 300 and 650 °C. Quasi‐isothermal oxidation tests carried out at 850 °C for exposure time of 2 000 h exhibited a lower mass gain of HIPIMS‐HIPIMS coatings by a factor of 2 and 6 as compared to the HIPIMS/UBM deposited coatings and uncoated γ‐TiAl substrate respectively.
The Influence of the Coating Thickness on the Phase and Element Composition of a ‘Ti Coating/Steel’ System Surface Layer Treated by a Compression Plasma Flow
Authors: Cherenda Nikolai N. , Uglov Vladimir V. , Poluyanova Marina G. , Astashynski Valentin M. , Kuzmitski Anton M. , Pogrebnjak Alexander D. , Stritzker Bernd
Published: June 2009

The phase and element composition, microhardness of a ‘Ti/steel’ system mixed under the action of compression plasma flows have been investigated in this work. Non‐Rutherford backscattering, X‐ray diffraction, scanning electron microscopy and Vickers microhardness measurements were used for samples characterization. The findings showed that the change of the coating thickness in the range of 0.5–5 µm resulted in the Ti concentration change in the mixed layer from 4 to 30 at.‐%. The increase of the titanium content was accompanied by the formation of a supersaturated α‐Fe(Ti) solid solution, Fe2Ti and TiN. The phase composition changes and quenching effect led to the surface layer microhardness increase.
Deposition of Barrier Layers for Thin Film Solar Cells Assisted by Bipolar Substrate Biasing
Authors: Häberle Evelyn , Kopecki Jochen , Schulz Andreas , Walker Matthias , Stroth Ulrich
Published: June 2009

For the development of diffusion and insulation barriers for thin film solar cells on unpolished steel with a rough surface as substrate, investigations of the shape of deposited SiOx layers in dependence on an applied substrate biasing are carried out. Si‐wafers with a well‐defined surface structure in the range of micrometre are used as ‘model’ substrate. As a result, the deposition in the indentations of this surface is much higher in the case of a biased substrate. To determine the influence of the bias on the molecular structure, first investigations of the deposited layer without an applied bias are performed with in situ Fourier Transform InfraRed (FTIR) spectroscopy. Hence the molecular composition of the films is monitored during the deposition. In these spectra the Berreman effect occurs and is analysed.
Comparison Between Non‐equilibrium Atmospheric‐Pressure and Low‐Pressure Plasma Treatments of Poly(styrene–butadiene–styrene) Elastomers
Authors: Tyczkowski Jacek , Zieliński Jakub , Kopa Agnieszka , Krawczyk Iwona , Woźniak Bogusław
Published: June 2009

Low‐pressure plasma generated in a typical parallel plate reactor and atmospheric pressure plasma produced by a plasma needle were utilized to modify the surface of poly(styrene–butadiene–styrene) (SBS) elastomers. An RF discharge (13.56 MHz) in helium was used in the both cases. The SBS surfaces were investigated by T‐peel tests, contact‐angle measurements, and IRS–FTIR spectroscopy. It has been found that such plasma treatments drastically improve the strength of adhesive‐bonded joints between the SBS surfaces and polyurethane adhesives, however, the plasma needle operation has turned out to be more effective. The molecular processes proceeding on the SBS surfaces have been briefly discussed.
Atmospheric Pressure Plasma Deposition of Adhesion Promotion Layers on Aluminium
Authors: Bringmann Philipp , Rohr Oliver , Gammel Franz J. , Jansen Irene
Published: June 2009

The paper presents investigations on the deposition of plasma polymerised films at atmospheric pressure as a pretreatment for painting and adhesive bonding of aircraft aluminium structures. Two different plasma jet sources are employed, one based on a controlled arc discharge and air as process gas, and another based on a dielectric barrier discharge (DBD) and He as plasma gas. The organosilicon precursors HMDSO, TEOS and OMCTS are used with both plasma sources. Deposition in the arc discharge plasma jet leads to almost carbon‐free silica coatings, whereas coatings deposited with the DBD jet source contain a high amount of carbon, varying with precursor type. The obtained results of corrosion investigations and adhesion tests are promising, as some representative aircraft industry requirements could be achieved. However, the investigations show a strong dependency on the used precursor and type of polymer (paint or adhesive) applied on the plasma polymerised film.
The Influence of Process Parameters on Chemistry, Roughness and Morphology of Siloxane Films Deposited by an Atmospheric Plasma Jet System
Authors: Ramamoorthy Amsarani , Rahman Mahfujur , Mooney Damian A. , Don MacElroy James M. , Dowling Denis P.
Published: June 2009

Siloxane coatings were deposited onto Vycor™ glass and silicon substrates from a tetraethyl orthosilicate (TEOS) precursor using the PlasmaStream™ atmospheric plasma jet system. The TEOS precursor was nebulized into He/O2 plasma and the coating growth rate was controlled by the number of passes of the jet over the ceramic substrates. The system process parameters were systematically varied to study their influence on the coating properties. The chemical properties, surface roughness, and morphology of the 1–200 nm thick coatings were studied as a function of both applied plasma power and TEOS flow rate. The deposited coatings were examined using ellipsometry, contact angle measurement, optical profilometry, Fourier transform infrared spectroscopy (FT‐IR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM).
Depositon of Dielectric Films with Inductively Coupled Plasma‐CVD in Dependence on Pressure and Two RF‐Power‐Sources
Authors: Jatta Sandro , Haberle Klaus , Klein Andreas , Schafranek Robert , Koegel Benjamin , Meissner Peter
Published: June 2009

This paper presents the investigations of thin dielectric silicon oxide (SiOx) and silicon nitride (SiNx) films deposited below 100 °C by a plasma enhanced chemical vapour deposition (PECVD) using an inductively coupled plasma (ICP)‐source. The influence of the deposition pressure and the applied RF‐power to the plasma from the ICP‐source and a second RF‐power at substrate electrode on the characteristics of the deposited films are studied. The investigated characteristics are refractive index R.I. at 632 nm, deposition rate Rdep, stress σ and etching rate Retch in buffered hydrofluoric acid (BHF). Measurements from electron spectroscopy for chemical analysis (ESCA) support the investigations. The results are discussed and compared with other PECVD deposition methods. A significant influence of the RF‐generator connected to substrate electrode on etching rate and hence on film quality is identified for SiOx but the converse effect is identified for SiNx‐films.
Angularly and Spatially Resolved Measurements of the Energy Flux in an RF Plasma Using a Thermal Probe
Authors: Wolter Matthias , Stahl Marc , Kersten Holger
Published: June 2009

The total energy flux for an RF plasma (13.56 MHz) has been measured by means of a simple thermal probe. The procedure is based on the measurement of time dependent changes of the probe temperature during the plasma process. A substrate dummy which is thermally isolated and inserted into the plasma at substrate position served as thermal probe which can be moved in vertical and horizontal directions in order to measure the different energy fluxes and their distribution in the reactor vessel. The knowledge of the spatial distribution is important, for example, for coating or sputtering processes. Different contributions to the total energy flux are identified by different orientations of the thermal probe, e.g., if the probe is facing the RF electrode the energy flux is much higher than in the opposite direction. This difference can be addressed to an additional energetic contribution due to secondary electron emission from the powered RF electrode.
Multilayer Diffusion Barrier Coatings on Poly(propylene) with Improved Temperature Durability
Authors: Körner Lutz , Sonnenfeld Axel , Rudolf von Rohr Philipp
Published: June 2009

The improvement of temperature durability for autoclaving of silicon oxide (SiOx) diffusion barrier coatings on poly(propylene) (PP) by deposition of thin amorphous hydrogenated carbon‐nitrogen (a‐C:N:H) intermediate layers was investigated. Attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy revealed terminating amino and nitrile groups responsible for low compressive stress in a‐C:N:H. Uniaxial tensile tests showed a higher crack onset strain (COS) for a‐C:N:H of 2.7% compared to 0.7% for SiOx. Best temperature durability was achieved by a three‐layer coating from a‐C:N:H, an intermediate layer deposited by a mixture of N2, C2H2, hexamethyldisiloxane (HMDSO), and a SiOx layer. The oxygen transmission rate (OTR) was only increased from 6 to 22 cm3·m−2·d−1·bar−1 after exposure to 140 °C for 30 min, whereas for single SiOx barrier coatings, severe loss of barrier properties of 1 040 cm3·m−2·d−1·bar−1 was evidenced due to the formation of cracks.
1‐D Self‐consistent Fluid Modelling of the Pulsed Magnetron Discharge
Authors: Thomason Philip , Browning Philippa , Bradley James
Published: June 2009

A 1‐D fluid code simulation of the region above the racetrack in a magnetron discharge has been developed to yield predictions for the temporal evolution of the axial plasma parameters during pulsed DC operation. To take into account anomalous cross‐field diffusion transport rates, an effective magnetic field profile has been calculated based on the real experimental values, to yield ratios in the effective electron gyro and collision frequencies comparable with Bohm diffusion. Pulse frequencies from 100 to 500 kHz are considered, with gas pressures ranging from 0.25 to 0.65 Pa. The model results for the plasma potential, electron and ion densities, during the pulse cycle agree well with experimental measurements made in the Liverpool magnetron using time‐resolved Langmuir and emissive probes. In the bulk plasma, the predictions for electron temperature are close to the measured values; however, in the sheath region they are artificially high due to the model assumption that only Maxwellian distributed electrons exist in all regions of the discharge. This inadequacy in the model and the methods to improve has been discussed. Results for DC magnetrons are also shown.
Chemically Directed Assembling of Functionalized Luminescent Nanocrystals onto Plasma Modified Substrates Towards Sensing and Optoelectronic Applications
Authors: Sardella Eloisa , Liuzzi Francesco D. , Comparelli Roberto , Depalo Nicoletta , Striccoli Marinella , Curri M. Lucia , Agostiano Angela , Favia P. , d'Agostino Riccardo
Published: June 2009

In this work semiconductor nanocrystals (NCs) were assembled by means of a layer‐by‐layer procedure, by properly combining RF (13.56 MHz) glow discharge‐assisted processes with wet chemistry approaches. Colloidal core shell type NCs formed by CdSe coated with an epitaxial layer of ZnS (CdSe@ZnS) were then assembled, from aqueous solution, onto the plasma modified materials. The obtained results show that spatially resolved NC assembling can be successfully achieved on micro‐structured domains obtained by means of plasma assisted processes. Layers of functionalized NCs are thus demonstrated to be materials that can be effectively integrated into devices for application in photovoltaics, electronic nano‐devices and biological sensors.
Effects of spinosad on Helicoverpa armigera (Lepidoptera: Noctuidae) from China: tolerance status, synergism and enzymatic responses
Authors: Wang Dong , Qiu Xinghui , Ren Xuexiang , Zhang Wencheng , Wang Kaiyun
Published: June 2009

BACKGROUND: Spinosad is increasingly used in pest management programmes, and resistance to it has been detected in recent years. However, there is no report on the susceptibilities of field populations of Helicoverpa armigera (Hübner) from China. Furthermore, the impact of spinosad on metabolic enzymes in this pest remains unknown.

RESULTS: Four populations of H. armigera from different locations in China displayed less than 6.5‐fold difference in LC50 to spinosad, the highest being in the Xinjiang population, followed by Xiajin, Taian and Hubei populations, while there was no significant difference at LC99 level among the four populations. The toxicity of spinosad could be synergised by piperonyl butoxide (PBO) and triphenylphosphate (TPP), but not by diethyl maleate (DEM). Spinosad exposure for 48 h significantly increased the activities of p‐nitroanisole O‐demethylase (ODM), while no significant changes in glutathione‐S‐transferase (GST) and carboxyl esterase (CarE) were observed.

CONCLUSION: Field populations of H. armigera from China displayed marginally different susceptibilities to spinosad and had a relatively low LC50. Cytochrome P450 monooxygenase might be involved in the metabolism of, and hence resistance to, spinosad in this pest in China. Copyright © 2009 Society of Chemical Industry
Formation of extended defects in 4H‐SiC epitaxial growth and development of a fast growth technique
Authors: Tsuchida Hidekazu , Ito Masahiko , Kamata Isaho , Nagano Masahiro
Published: June 2009

This paper surveys extended defects in 4H‐SiC epilayers and reports recent results concerning fast epitaxial growth. Synchrotron X‐ray topography, transmission electron microscopy, Nomarski optical microscopy and defect selective etching analysis are applied to investigate the nucleation and propagation of carrot defects, basal plane Frank‐type defects, polytype inclusions and basal plane dislocations (BPDs) in 4H‐SiC epitaxial growth. In the development of the 4H‐SiC fast epitaxial growth technique, a very high growth rate of up to 250 μm/h is obtained in a newly developed vertical hot‐wall‐type reactor under low system pressure using a H2 + SiH4 + C3H8 system. Good thickness and impurity doping uniformity are also obtained simultaneously over a large area, with the retention of a high growth rate. A 4H‐SiC epilayer virtually free from BPDs is obtained on a 4° off Si‐face substrate. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of defect evolution in multi‐energy helium implanted monocrystalline and polycrystalline silicon
Authors: Abrams K. J. , Donnelly S. E. , Beaufort M.‐F. , Terry J. , Haworth L. I. , Alquier D.
Published: June 2009

Upon implantation, He ions interact with radiation damage in metals and semiconductors to form bubbles (V. Raineri, Phys. Rev. B 2, 937 (2000) [1]). As far as Si is concerned, recent literature contains much information on the effects of ion implantation, defect formation and the transport of point defects in He‐irradiated crystalline silicon (c‐Si) whereas little information exists on the effects of He implantation on polycrystalline Si (poly‐Si). This paper reports on a systematic comparison of the effects of He implantation on c‐Si and poly‐Si. Interesting and significant differences were observed in the defect morphology in the two cases. Results on the differences between the two materials are presented and discussed in terms of the role that grain boundaries in poly‐Si play in trapping interstitials and the effects that this may have on the overall defect morphology. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extended defects generated in the slip plane by moving dislocation in diamond lattice crystals: morphology and properties
Authors: Eremenko V. , Demenet J.‐L. , Rabier J.
Published: June 2009

An analysis of the morphology of the extended defects revealed behind dislocation in the slip plane of silicon is presented. These extended defects show an electrical activity contradictorily to dislocations themselves; this is confirmed by Electron Induced Surface Potential (EISP) measurements. It is shown, that the generation of these extended defects is a common phenomenon for diamond lattice materials. The defects generation which has to be elucidated is considered to be relevant to a dynamical dislocation core structure during the plastic deformation of semiconductor materials with covalent lattice. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localisation and identification of recombination‐active extended defects in crystalline silicon by means of focused ion‐beam preparation and transmission electron microscopy
Authors: Stolze L. , Saring P. , Rudolf C. , Seibt M.
Published: June 2009

This paper reports on the localisation of extended defects related to the co‐precipitation of transition metal impurities in silicon and their preparation for subsequent analysis using techniques of transmission electron microscopy (TEM). Two approaches are described, i.e. (i) localisation of recombination‐active defects by light‐beam induced current followed by preferential chemical etching and TEM sample preparation using focused‐ion beam (FIB), and (ii) the replacement of the chemical etching by in situ Ga+ irradiation in the FIB system. The former technique is successfully applied to copper‐rich precipitate colonies in silicon whereas the latter proofs to be the superior approach for nickel‐rich particles. Structural and chemical analyses using TEM techniques are described for both cases (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic effects and ring strain influences on the electron uptake by selenium‐containing bonds
Authors: Dumont Élise , Loos Pierre‐François , Laurent Adèle D. , Assfeld Xavier
Published: June 2009

The gas‐phase electron attachment of thiaselena and diselena derivatives is investigated on model organic systems by ab initio calculations (level of theory MP2/DZP++). Electronic contributions favor the one‐electron addition on selenium‐containing compounds, with adiabatic electron affinities of 0.03, 0.24, and 0.43 eV, respectively, for dimethyldisulfide, dimethylselenenylsulfide, and dimethyldiselenide. This ensures the possibility of an excess electron binding on SeS and SeSe linkages. The so‐formed radical anionic intermediates present a three‐electrons two‐centers 2c3e bond, whose nature is confirmed by Mulliken spin densities and NBO analysis. They are stable towards dissociation, with a low barrier evaluated between about 25–60 kJ/mol. Cyclization strongly enhances dichalcogen propensity to fix an excess electron. Adiabatic electron affinities of a series of 1,2‐thiaselena‐cycloalkanes and 1,2‐diselena‐cycloalkanes are positive and range from 0.24 to 1.30 eV. This can be traced back to the release of ring strain energy upon one‐electron addition: this geometrical effect is nevertheless less marked than for disulfide analogs. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Nuclear quantum effects on the He2H+ complex with the nuclear molecular orbital approach
Authors: González Sergio A. , Reyes Andrés
Published: June 2009

The nuclear quantum effects (NQE) on the geometries and energies of the HeH+ and He2H+ complexes and their hydrogen isotopologues are investigated with the recently developed APMO/MP2 code. This code implements the Nuclear Molecular Orbital Approach (NMO) at a MP2 level of theory for electrons and quantum nuclei. In a first investigation of NQE on HeH+, we have observed a reduction in the bond distance as the mass of the hydrogen isotope is increased. Our calculated bond distances are in good agreement with experiment. We have also studied the H/D/T isotope effects on the geometry, total energy and stabilization energy of HeHHe+. We have also determined the relation between nuclear mass and delocalization and found that the lighter the nucleus the more delocalized it is. Our results demonstrate the importance of including nuclear quantum effects in these systems. To our knowledge, these are the first reported results on isotope effects on the HeH+ and He2H+ complexes using a NMO method. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Random dense bipartite graphs and directed graphs with specified degrees
Authors: Greenhill Catherine , McKay Brendan D.
Published: June 2009

Let s and t be vectors of positive integers with the same sum. We study the uniform distribution on the space of simple bipartite graphs with degree sequence s in one part and t in the other; equivalently, binary matrices with row sums s and column sums t. In particular, we find precise formulae for the probabilities that a given bipartite graph is edge‐disjoint from, a subgraph of, or an induced subgraph of a random graph in the class. We also give similar formulae for the uniform distribution on the set of simple directed graphs with out‐degrees s and in‐degrees t. In each case, the graphs or digraphs are required to be sufficiently dense, with the degrees varying within certain limits, and the subgraphs are required to be sufficiently sparse. Previous results were restricted to spaces of sparse graphs. Our theorems are based on an enumeration of bipartite graphs avoiding a given set of edges, proved by multidimensional complex integration. As a sample application, we determine the expected permanent of a random binary matrix with row sums s and column sums t. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Review of statistical analyses in drug discovery and chemogenomics
Authors: Liu Yushi , Verducci Joseph S.
Published: June 2009

A review of the basic organizational structure of chemogenomics outlines how chemoinformatics, combinational and medicinal chemistry integrate with microarray methods and systems biology to discover new drugs. Key statistical issues include investigations of quantitative structural activity relationships (QSARs), the role of compound similarity in constructing experimental designs, and techniques for getting reliable and accurate measures of genomic response. Four current areas of research are highlighted: correlational analyses, integration of non‐coding RNA signals into modeling, connectivity maps, and yeast deletion libraries. Copyright © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 2: 88‐102, 2009
Mistakes encountered during automatic peak identification of minor and trace constituents in electron‐excited energy dispersive X‐ray microanalysis
Authors: Newbury Dale E.
Published: June 2009

Automated peak identification in electron beam‐excited X‐ray microanalysis with energy dispersive X‐ray spectrometry has been shown to be subject to occasional mistakes even on well‐separated, high‐intensity peaks arising from major constituents (arbitrarily defined as a concentration, C, which exceeds a mass fraction of 0.1). The peak identification problem becomes even more problematic for constituents present at minor (0.01≤C≤0.1) and trace (C<0.01) levels. “Problem elements” subject to misidentification as major constituents are even more vulnerable to misidentification when present at low concentrations in the minor and trace ranges. Additional misidentifications attributed to trace elements include minor X‐ray family members associated with major constituents but not assigned properly, escape and coincidence peaks associated with major constituents, and false peaks owing to chance groupings of counts in spectra with poor counting statistics. A strategy for robust identification of minor and trace elements can be based on application of automatic peak identification with careful inspection of the results followed by multiple linear least‐squares peak fitting with complete peak references to systematically remove each identified major element from the spectrum before attempting to assign remaining peaks to minor and trace constituents. SCANNING 31: 91–101, 2009. Published by Wiley Periodicals, Inc.
Density‐adaptive network reprogramming protocol for wireless sensor networks
Authors: Cho Sungkyu , Shin Hyojeong , Han Seungjae , Cha Hojung , Ha Rhan
Published: June 2009

Network reprogramming is a process used to update program codes of sensor nodes that are already deployed. To deal with potentially unstable link conditions of wireless sensor networks, the epidemic approach based on 3‐way advertise‐request‐data handshaking is preferred for network reprogramming. Existing epidemic protocols, however, require a long completion period and high traffic overhead in high‐density networks, mainly due to the hidden terminal problem. In this paper, we address this problem by dynamically adjusting the frequency of advertisement messages in terms of the density of sensor nodes, which is the number of sensor nodes in a certain area. We compare the performance of the proposed scheme, called DANP (Density‐Adaptive Network Reprogramming Protocol), with a well‐known epidemic protocol, Deluge. Simulations indicate that, in the grid topologies, DANP outperforms Deluge by about 30% in terms of the completion time and about 50% in terms of the traffic overhead. Significant performance gain is observed in random topologies as well. The performance of DANP is further confirmed via measurements in an experimental test bed. Copyright © 2009 John Wiley & Sons, Ltd.
A network coding based interference cancelation scheme for wireless ad hoc networks
Authors: Chen Chen , Bai Lin , Cai Kai , He Jianhua , Xiang Haige
Published: June 2009

The performance of wireless networks is limited by multiple access interference (MAI) in the traditional communication approach where the interfered signals of the concurrent transmissions are treated as noise. In this paper, we treat the interfered signals from a new perspective on the basis of additive electromagnetic (EM) waves and propose a network coding based interference cancelation (NCIC) scheme. In the proposed scheme, adjacent nodes can transmit simultaneously with careful scheduling; therefore, network performance will not be limited by the MAI. Additionally we design a space segmentation method for general wireless ad hoc networks, which organizes network into clusters with regular shapes (e.g., square and hexagon) to reduce the number of relay nodes. The segmentation method works with the scheduling scheme and can help achieve better scalability and reduced complexity. We derive accurate analytic models for the probability of connectivity between two adjacent cluster heads which is important for successful information relay. We proved that with the proposed NCIC scheme, the transmission efficiency can be improved by at least 50% for general wireless networks as compared to the traditional interference avoidance schemes. Numeric results also show the space segmentation is feasible and effective. Finally we propose and discuss a method to implement the NCIC scheme in a practical orthogonal frequency division multiplexing (OFDM) communications networks. Copyright © 2009 John Wiley & Sons, Ltd.
Endoscopic Total Parathyroidectomy and Partial Parathyroid Tissue Autotransplantation for Patients with Secondary Hyperparathyroidism: A New Surgical Approach
Authors: Sun Yueming , Cai Huihua , Bai Jianfeng , Zhao Hanlin , Miao Yi
Published: June 2009

Background

Secondary hyperparathyroidism (SHPT) (i.e., renal hyperparathyroidism) is one of the most serious complications in long‐term hemodialysis patients. The purpose of this retrospective study was to explore the feasibility of a new surgical approach—endoscopic total parathyroidectomy with autotransplantation (ETP+AT)—and evaluate its practical application for patients with SHPT.

Methods

The study included 34 SHPT patients who underwent ETP+AT from among 67 cases at the Department of Minimally Invasive Surgery, the First Affiliated Hospital of Nanjing Medical University over a 3‐year period. The other 33 patients underwent traditional total parathyroidectomy with autotransplantation (TP+AT). Two criteria were used as indications to perform ETP+AT in SHPT patients. The first was a high serum parathyroid hormone level (PTH >800 pg/ml) associated with hypercalcemia and/or hyperphosphatemia that which were refractory to medical treatment. The second criterion was the presence of clinical symptoms including pruritus, bone and joint pain, muscle weakness, progression of soft tissue calcification, and spontaneous fractures. Ultrasonography, 99mTc sestamibi scans, and computed tomography were used to evaluate the thyroid and parathyroid glands.

Results

There was no surgery‐related mortality among any of the patients with ETP+AT. One patient underwent conventional neck exploration because of bleeding and injury of a unilateral recurrent laryngeal nerve after the operation. Preoperative symptoms were alleviated, and the serum PTH and alkaline phosphatase levels, hyperphosphatemia, and hypercalcemia were improved or normalized in most patients. Recurrence was observed in one patient with a sixth parathyroid gland behind his thyroid, and the patient required a second operation. Hypoparathyroidism was not found after the operation. The clinical data were compared between ETP+AT and TP+AT.

Conclusions

ETP+AT is a safe option for the treatment of SHPT with low morbidity and mortality, shorter hospital stay and low recurrence rate. It is important to avoid intraoperative bleeding, identify all parathyroid glands during the surgery, and choose adequate parathyroid tissues for autografting.
Prophylactic Thoracic Duct Mass Ligation Prevents Chylothorax After Transthoracic Esophagectomy for Cancer
Authors: Cagol Matteo , Ruol Alberto , Castoro Carlo , Alfieri Rita , Michieletto Silvia , Ancona Ermanno
Published: June 2009

Background

Chylothorax after transthoracic esophagectomy for cancer is an uncommon but potentially life‐threatening postoperative complication. It has been reported that preventive thoracic duct ligation can reduce the incidence of postoperative chylothorax after esophagectomy for cancer. In this prospective series, we evaluated the results of preventive intraoperative thoracic duct mass ligation in patients who underwent transthoracic esophagectomy for cancer.

Methods

From 2001 to 2006, 323 patients underwent transthoracic esophagectomy for cancer and duct ligation during the operation was routinely performed.

Results

No intraoperative or postoperative complications directly related to the procedure were recorded. No postoperative chylothorax was observed.

Conclusions

In this series, the technique of intraoperative thoracic duct mass ligation proved to be safe and effectively prevented postoperative chylothorax in patients who underwent transthoracic esophagectomy for cancer.
Sense of Community in Hong Kong: Relations with Community‐Level Characteristics and Residents’ Well‐Being
Authors: Mak Winnie W. S. , Cheung Rebecca Y. M. , Law Lawrence S. C.
Published: June 2009

Sense of community (SOC) has been one of the most studied topics in community psychology. However, no empirical study to date has investigated SOC in Hong Kong and its relations with community characteristics and residents’ psychological well‐being. A representative sample of 941 Hong Kong Chinese based on a randomized household survey was conducted in all 18 districts in Hong Kong. Results of hierarchical linear modeling indicated that SOC was not associated with sociodemographic indicators on both the individual‐level (i.e., gender, age, family income, education level, type of residence, and area‐to‐capita ratio of residence) and the community‐level (i.e., proportion of individuals with tertiary education, median family income, ownership of residence, population density, and resident stability). SOC was negatively related to daily hassles and positively with social support and quality of life. Conceptualization of SOC in Hong Kong was discussed.
Participatory Research in Systems of Care for Children's Mental Health
Authors: Pullmann Michael D.
Published: June 2009

The children's system of care initiative in the United States requires the participation of caregivers of children with emotional or behavioral problems in conducting research and evaluation. This entails a restructuring of traditional power dynamics among families served by the community mental health system and other system stakeholders, including researchers. However, evidence indicates that system of care research may not currently embrace the different types of knowledge possessed by caregivers and may be frustrated by traditional power hierarchies, resulting in research findings that are not useful for the community. In this paper I examine a framework for power and knowledge and examine how, when viewed through this framework, participatory research in the system of care initiative thus far may be less than authentic. I conclude with improvements suggested by the framework that are expected to shift power to caregivers and result in more useful, actionable research findings for the community.
Vertical heterogeneity of a forest floor invertebrate food web as indicated by stable‐isotope analysis
Authors: Okuzaki Yutaka , Tayasu Ichiro , Okuda Noboru , Sota Teiji
Published: June 2009

Diverse populations of invertebrates constitute the food web in detritus layers of a forest floor. Heterogeneity in trophic interactions within such a species‐rich community food web may affect the dynamic properties of biological communities such as stability. To examine the vertical heterogeneity in trophic interactions among invertebrates in litter and humus layers, we studied differences in species composition and variations in carbon and nitrogen stable‐isotope ratios (δ13C and δ15N) using community‐wide metrics of the forest floors of temperate broadleaf forests in Japan. The species composition differed between the two layers, and the invertebrates in the litter layer were generally larger than those in the humus layer, suggesting that these layers harbored separate food webs based on different basal resources. However, the δ13C of invertebrates, an indicator of differences in the basal resources of community food webs, did not provide evidence for separate food webs between layers even though plant‐derived organic matter showed differences in stable‐isotope ratios according to decomposition state. The minimum δ15N of invertebrates also did not differ between layers, suggesting sharing of food by detritivores from the two layers at lower trophic levels. The maximum and range of δ15N were greater in the humus layer, suggesting more trophic transfers (probably involving microorganisms) than in the litter layer and providing circumstantial evidence for weak trophic interactions between layers at higher trophic levels. Thus, the invertebrate community food web was not clearly compartmentalized between the detrital layers but still showed a conspicuous spatial (vertical) heterogeneity in trophic interactions.
Scoliosis in a Case of Schinzel–Giedion Syndrome
Authors: Sharma Amit K. , Gonzales Joseph A.
Published: June 2009

Schinzel–Giedion syndrome (SGS) is a rare disorder characterized by midface retraction, hypertrichosis, and multiple skeletal anomalies with severe mental retardation. Various skeletal manifestations of the disease have been previously described. We present the first case of SGS developing scoliosis. The patient presented with scoliosis at the age of 8 years which rapidly progressed to severe thoraco-lumbar scoliosis. Survival beyond 2 years is rare in this syndrome. The objective of this report is to describe the possibility of development of scoliosis in SGS due to the neuromuscular nature of the syndrome, especially in long survivors.
Enhanced Microwave Absorption Properties of Intrinsically Core/shell Structured La0.6Sr0.4MnO3Nanoparticles
Authors: Cheng Y. L. , Dai J. M. , Zhu X. B. , Wu D. J. , Yang Z. R. , Sun Y. P.
Published: June 2009

The intrinsically core/shell structured La0.6Sr0.4MnO3nanoparticles with amorphous shells and ferromagnetic cores have been prepared. The magnetic, dielectric and microwave absorption properties are investigated in the frequency range from 1 to 12 GHz. An optimal reflection loss of −41.1 dB is reached at 8.2 GHz with a matching thickness of 2.2 mm, the bandwidth with a reflection loss less than −10 dB is obtained in the 5.5–11.3 GHz range for absorber thicknesses of 1.5–2.5 mm. The excellent microwave absorption properties are a consequence of the better electromagnetic matching due to the existence of the protective amorphous shells, the ferromagnetic cores, as well as the particular core/shell microstructure. As a result, the La0.6Sr0.4MnO3nanoparticles with amorphous shells and ferromagnetic cores may become attractive candidates for the new types of electromagnetic wave absorption materials.
Representation Rethought: On Trustees, Delegates, and Gyroscopes in the Study of Political Representation and Democracy
Authors: REHFELD ANDREW
Published: June 2009

The trustee/delegate problem purportedly expresses how closely a representative's votes in the legislature should correspond to their constituents' preferences. In this article, I argue that the usual formulation of this debate collapses three distinctions—aims, source of judgment, andresponsiveness—and thus obscures the underlying complexity of the phenomenon. Given its tripartite formulation, the collapse of these distinctions into a binary “trustee/delegate” formulation obscures a more complex political landscape with eight—rather than two—ideal types. Furthermore, once unpacked, we can see that the distinctions operate entirely independent of the location of authority, leading to the seemingly paradoxicalinstructedtrustees andindependentdelegates. I also claim that the three distinctions apply to any decision maker, and thus, the attribution of this problem as distinctive of democratic political representation is an important overstatement. The article thus contributes to a more general theory of political representation that can be applied in nonelectoral and nondemocratic contexts increasingly relevant to global politics.