bluuebunny/crossref_metadata_2025 huggingface dataset:
A Dimeric Magnesium(I) Compound as a Facile Two‐Center/Two‐Electron Reductant
Authors: Bonyhady Simon J. , Green Shaun P. , Jones Cameron , Nembenna Sharanappa , Stasch Andreas
Published: March 2009

The odd couple: A dimeric magnesium(I) complex acts as a facile and selective two‐center/two‐electron reductant towards a series of unsaturated substrates (see scheme; Ar=2,6‐iPr2C6H3, Ad=1‐adamantyl). The novel reduced or reductively coupled products obtained from these reductions suggest that magnesium(I) compounds may find wide use in organic and organometallic syntheses.

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Syntheses, Photophysics, and Application of Iridium(III) Phosphorescent Emitters for Highly Efficient, Long‐Life Organic Light‐Emitting Diodes
Authors: Lee Tsang‐Chi , Chang Chiung‐Fang , Chiu Yuan‐Chieh , Chi Yun , Chan Tzu‐Ying , Cheng Yi‐Ming , Lai Chin‐Hung , Chou Pi‐Tai , Lee Gene‐Hsiang , Chien Chen‐Han , Shu Ching‐Fong , Leonhardt Jens
Published: March 2009

Long live the OLED! Rational design and synthesis of IrIII complexes bearing two cyclometalated ligands (C N) and one 2‐(diphenylphosphino)phenolate chelate (P O) as well as the corresponding IrIII derivatives with only one (C N) ligand and two P O chelates are reported. According to the observed photophysical data, a P O ligand is found to be able to fine‐tune the light‐emitting electronic transition of these complexes.

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Rational design and synthesis of IrIII complexes (1–3) bearing two cyclometalated ligands (C^N) and one 2‐(diphenylphosphino)phenolate chelate (P^O) as well as the corresponding IrIII derivatives (4–6) with only one (C^N) ligand and two P^O chelates are reported, where (C^NH)=phenylpyridine (ppyH), 1‐phenylisoquinoline (piqH), and 4‐phenylquinazoline (nazoH). Single crystal X‐ray diffraction studies of 3 reveal a distorted octahedral coordination geometry, in which two nazo ligands adopt an eclipsed configuration, with the third P^O ligand located trans to the phenyl group of both nazo ligands, confirming the general skeletal pattern for 1–3. In sharp contrast, complex 4 reveals a trans‐disposition for the PPh2 groups, along with the phenolate groups residing opposite the unique cyclometalated ppy ligand, which is the representative structure for 4–6. These IrIII complexes exhibit green‐to‐red photoluminescence with moderate to high quantum efficiencies in the degassed fluid state and bright emission in the solid state. For 1–6, the resolved emission spectroscopy and relaxation dynamics are well rationalized by the computational approach. OLEDs fabricated using 12 wt. % of 3 doped in CBP and with BCP as hole blocking material, give bright electroluminescence with λmax=628 nm and CIExy coordinates (0.65, 0.34). The turn‐on voltage is 3.2 V, while the current efficiency and the power efficiency reach 11.2 cd A−1 and 4.5 lm W−1 at 20 mA cm−2. The maximum efficiency reaches 14.7 cd A−1and 6.8 lm W−1 upon switching to TPBI as hole blocking material. For evaluating device lifespan, the tested device incorporating CuPc as a passivation layer, 3 doped in CTP as an emitting layer, and BAlq as hole blocking material, shows a remarkably long lifetime up to 36 000 h at an initial luminance of 500 cd m−2.
Luminol‐dependent chemiluminescence of human phagocyte cell lines: comparison between DMSO differentiated PLB 985 and HL 60 cells
Authors: Ashkenazi Avraham , Marks Robert. S.
Published: March 2009

The human promyelocytic leukemia HL 60 and PLB 985 cell lines can differentiate into terminally mature neutrophil‐like cells via dimethyl sulfoxide (DMSO) induction. In this study the luminol‐dependent chemiluminescence (LCL) of both neutrophil‐like cells was analayzed and compared in response to phorbol myristate acetate (PMA) and opsonized zymosan (OZ) stimulants. It was shown that, like human blood neutrophils, both neutrophil‐like cells expressed high levels of CD11b, but unlike human blood neutrophils these cells almost lack LCL‐detectable intracellular oxidase activity. By studying the pattern of activation to OZ and PMA and priming with GM‐CSF, we concluded that there is no difference between the percentage of differentiation and function of DMSO‐induced HL 60 and PLB 985. However, the LCL capacity (area under the curve) of DMSO induced PLB 985 cells was higher than that of HL 60 cells in response to both PMA and OZ, which implies a higher capacity to generate reactive oxygen species in PLB 985 cells. Copyright © 2009 John Wiley & Sons, Ltd.
The influence of dioxygen on luminol chemiluminescence
Authors: Baj Stefan , Krawczyk Tomasz , Staszewska Karina
Published: March 2009

Assays of peroxy compounds are commonly performed after chromatographic separation of analysed mixtures. In high‐performance liquid chromatography (HPLC), solvent reservoirs are sparged by helium or inline vacuum‐degassed in order to control the compressibility of the solvents for efficient pumping. In this study, we investigated the influence of degassing the reaction solution on the light output of the hemin‐catalyzed luminol oxidation by various oxidants. We found that, when t‐butyl hydroperoxide, hydrogen peroxide, n‐butyl hydroperoxide, iodosobenzene and iodobenzene diacetate were used as oxidants, the luminol chemiluminescence was lowered by 50–70% compared with an equilibrated and degassed solution. The opposite effect was observed when dibenzoyl peroxide and 3‐chloroperoxybenzoic acid were used as oxidants, as the chemiluminescence increased by approximately 20–30%. The reduced chemiluminescence was explained based on the known role of dioxygen in luminol chemiluminescence. The enhancement of chemiluminescence was rationalized by suggesting an alternative mechanism of luminol oxidation valid for peroxyacids and diacyl peroxides in which the reaction of a peroxyacid anion with the diazaquinone led to light emission with a higher quantum yield than the usual path, which is suppressed by the removal of dioxygen from the reaction solution. Copyright © 2009 John Wiley & Sons, Ltd.
Prediction of ice content in biological model solutions when frozen under high pressure
Authors: Guignon B. , Aparicio C. , Otero L. , Sanz P. D.
Published: March 2009

High pressure is, at least, as effective as cryoprotective agents (CPAs) and are used for decreasing both homogenous nucleation and freezing temperatures. This fact gives rise to a great variety of possible cryopreservation processes under high pressure. They have not been optimized yet, since they are relatively recent and are mainly based on the pressure–temperature phase diagram of pure water. Very few phase diagrams of biological material are available under pressure. This is owing to the lack of suitable equipment and to the difficulties encountered in carrying out the measurements. Different aqueous solutions of salt and CPAs as biological models are studied in the range of 0°C down to ‐35°C, 0.1 up to 250 MPa, and 0–20% w/w total solute concentration. The phase transition curves of glycerol and of sodium chloride with either glycerol or sucrose in aqueous solutions are determined in a high hydrostatic pressure vessel. The experimental phase diagrams of binary solutions were well described by a third‐degree polynomial equation. It was also shown that Robinson and Stokes' equation at high pressure succeeds in predicting the phase diagrams of both binary and ternary solutions. The solute cryoconcentration and the ice content were calculated as a function of temperature and pressure conditions during the freezing of a binary solution. This information should provide a basis upon which high‐pressure cryopreservation processes may be performed and the damages derived from ice formation evaluated. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Release of Volatile Aldehydes by the Brown Algal Kelp Laminaria digitata in Response to Both Biotic and Abiotic Stress
Authors: Goulitquer Sophie , Ritter Andrés , Thomas François , Ferec Cyrille , Salaün Jean‐Pierre , Potin Philippe
Published: March 2009

With a little kelp from my friends: In response to biotic and abiotic stress, the brown algal kelp Laminaria digitata releases volatile fatty acid aldehydes under laboratory conditions and in its natural environment (red). In response to 4‐HHE treatment, L. digitata releases (13S)‐HOTrE (green). These results support the hypothesis that these compounds may mediate kelp responses to stress.

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Attosecond Quantum Stroboscope
Authors: Paulus Gerhard G. , Stania Gernot
Published: March 2009

Electron disco: A “quantum stroboscope” for capturing the electron motion on a subfemtosecond timescale for a particular class of problems is highlighted. The picture shows a diffraction pattern caused by wave packets obtained by synchronizing attosecond UV pulses to a near‐IR field and ionizing rare‐gas atoms.

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Cover Picture: Tuneable Control of Interfacial Rheology and Emulsion Coalescence (ChemPhysChem 5/2009)
Authors: Malcolm Andrew S. , Dexter Annette F. , Katakdhond Jayant A. , Karakashev Stoyan I. , Nguyen Anh V. , Middelberg Anton P. J.
Published: March 2009

The cover picture illustrates a microfluidic dodecane‐in‐water emulsion stabilized by the designed peptide surfactant AM1, which forms a cohesive interfacial layer through reversible interaction with ZnII. Deformed coagulated droplets are stabilized against coalescence in the presence of an elastic interfacial layer, but coalesce rapidly following ZnII chelation with EDTA. A. P. J. Middelberg et al show on page 778 that coalescence rate can be controlled by altering interfacial rheology and hence the dynamics of thin film rupture.

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On nonlinear preconditioners in Newton–Krylov methods for unsteady flows
Authors: Birken Philipp , Jameson Antony
Published: March 2009

The application of nonlinear schemes like dual time stepping as preconditioners in matrix‐free Newton–Krylov‐solvers is considered and analyzed, with a special emphasis on unsteady viscous flows. We provide a novel formulation of the left preconditioned operator that says it is in fact linear in the matrix‐free sense, but changes the Newton scheme. This allows to get some insight in the convergence properties of these schemes, which is demonstrated through numerical results. Copyright © 2009 John Wiley & Sons, Ltd.
An adaptive gradient smoothing method (GSM) for fluid dynamics problems
Authors: Xu George X. , Liu G. R. , Tani Atusi
Published: March 2009

In this paper, a novel adaptive gradient smoothing method (GSM) based on irregular cells and strong form of governing equations for fluid dynamics problems with arbitrary geometrical boundaries is presented. The spatial derivatives at a location of interest are consistently approximated by integrally averaging of gradients over a smoothing domain constructed around the location. Such a favorable GSM scheme corresponds to a compact stencil with positive coefficients of influence on regular cells. The error equidistribution strategy is adopted in the solution‐based adaptive GSM procedure, and adaptive grids are attained with the remeshing techniques and the advancing front method. In this paper, the adaptive GSM has been tested for solutions to both Poisson and Euler equations. The sensitivity of the GSM to the irregularity of the grid is examined in the solutions to the Poisson equation. We also investigate the effects of error indicators based on the first derivatives and second derivatives of density, respectively, to the solutions to the shock flow over the NACA0012 airfoil. The adaptive GSM effectively yields much more accurate results than the non‐adaptive GSM solver. The whole adaptive process is very stable and no spurious behaviors are observed in all testing cases. The cosmetic techniques for improving grid quality can effectively boost the accuracy of GSM solutions. It is also found that the adaptive GSM procedure using the second derivatives of density to estimate the error indicators can automatically and accurately resolve all key features occurring in the flow with discontinuities. Copyright © 2009 John Wiley & Sons, Ltd.
Detection of irregular, transient fMRI activity in normal controls using 2dTCA: Comparison to event‐related analysis using known timing
Authors: Morgan Victoria L. , Gore John C.
Published: March 2009

When events occur spontaneously during the acquisition of a series of images, traditional modeling methods for detecting functional MRI activation detection cannot be employed. The two‐dimensional temporal clustering algorithm, 2dTCA, has been shown to accurately detect random, transient activations in computer simulations without the use of known event timings. In this study we applied the 2dTCA technique to detect the timings and spatial locations of sparse, irregular, transient activations of the visual, auditory, and motor cortices in 12 normal controls. Experiments with one and two independent types of stimuli were employed. Event‐related activation using known timing was compared with event‐related activation using 2dTCA‐detected timing in individuals and across groups. The 2dTCA algorithm detected the activation from all presented stimuli in every subject. When compared with block‐design results using a measure of correlation between activation maps, no significant difference was found between the 2dTCA activation maps and the event‐related maps using known timing across all subjects. Therefore, 2dTCA has the potential to be an accurate and more practical method for detection of spontaneous, transient events using fMRI. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.
Grafting tomato plant on tobacco plant and its effect on tomato plant yield and nicotine content
Authors: Yasinok Aysegul E , Sahin Feride I , Eyidogan Fusun , Kuru Mustafa , Haberal Mehmet
Published: March 2009

BACKGROUND:Two different tomato scions, cv. Elazig and cv. Sweet (cherry) (Solanum lycopersicumL.) were self‐grafted and grafted onto tobacco root stock (Nicotiana tobacumL.). Then, grafted tomato plants were evaluated in terms of flower and fruit yield. Tobacco‐grafted tomato plant fruits were also evaluated for nicotine content.

RESULTS:Tobacco grafting had a positive effect on the tomato plant cultivation performance; the onset of flowering was almost 15 days earlier and the tomato flower and fruit yields increased in both tomato cultivars. Tobacco grafting resulted in 5.0% and 30.1% increase in total fruit weight for cv. Sweet and cv. Elazig, respectively. Because the level of nicotine was within acceptable ranges, tobacco‐grafted tomato fruits were considered to be safe for consumption. Self‐grafted tomato cultivars also had flowering time onsets almost 11 days earlier. However, self‐grafting caused 6.0% and 7.6% less total fruit yield per cv. Sweet and cv. Elazig, respectively.

CONCLUSION:In conclusion, our results show that tomato–tobacco grafting is a novel and promising technique for improvement of not only tomato plant performance and yield, but also that it can be employed to various tomato varieties. Copyright © 2009 Society of Chemical Industry
Outcomes of primary surgical treatment of T1 and T2 carcinomas of the oropharynx
Authors: Moncrieff Marc , Sandilla Jessica , Clark Jonathan , Clifford Anthony , Shannon Kerwin , Gao Kan , O'Brien Christopher
Published: March 2009

Objectives:

Oropharyngeal cancers represent 10%–15% of all head and neck cancers. At presentation 60%–70% will have advanced‐stage disease with a high incidence of neck metastases. Primary treatment employing radiotherapy, with or without chemotherapy, is widely prescribed. The aim of this study is to analyze the outcome of definitive surgical management of T1–T2 cancers of the oropharynx.

Methods:

We conducted a retrospective cohort study of patients treated at the Sydney Head and Neck Cancer Institute. Patients with previously untreated squamous cell carcinoma (SCC) of the oropharynx were included according to the TNM stage of the disease as follows: T1 or T2, any N‐stage, and M0. All patients underwent definitive primary surgical management. Primary analysis endpoints were locoregional control rates and disease‐specific survival.

Results:

Ninety‐two patients were identified, of which 26 were T1 and 66 were T2. Forty‐four patients had clinical neck disease, and 57 had postoperative radiotherapy. The results showed no significant difference between the T1 and T2 groups with respect to local control or treatment type; however, advanced‐stage neck disease was associated with a worse prognosis. The 5‐year disease‐specific survival was 83% and local control rate was 87%. Ultimately, 25 of the 92 patients had treatment failure (27%).

Conclusions:

Selected patients with early‐stage primary cancers of the oropharynx may be effectively treated with definitive primary surgery. Laryngoscope, 119:307–311, 2009
Lithotripsy for refractory pediatric sialolithiasis
Authors: McJunkin Jonathan , Milov Simon , Jeyakumar Anita
Published: March 2009

Symptomatic salivary stones in the middle or proximal parotid duct have traditionally been treated by gland excision, which is associated with a 3% to 27% risk to the facial nerve in the pediatric population. Minimally invasive approaches to the management of salivary duct calculi have been introduced over the last several years. Fluoroscopically guided basket retrieval, lithotripsy, and intraoral stone removal under general anesthesia have found favor with many surgeons. Our patient had extracorporeal lithotripsy to his parotid gland with complete disintegration of the stone. He has had no evidence of stone recurrence or further bouts of parotitis. Extracorporeal shock wave lithotripsy with or without duct dilation is an efficient technique for the therapy of sialolithiasis in selected patients, especially patients who are at higher risk from a surgical standpoint. Laryngoscope, 119:298–299, 2009
Luminescent and Ionochromic Polyiminofluorene with Conjugated Terpyridine Substituent Groups
Authors: Rabindranath Aravinda Raman , Maier Anna , Schäfer Mathias , Tieke Bernd
Published: March 2009

Poly(N‐(4‐(2,2′:6,2″‐terpyridyl)phenyl)imino‐2,7‐fluorenylene P1‐2 was prepared upon palladium‐catalyzed polycondensation of 2,7‐dibromo‐9,9‐di‐n‐hexylfluorene 1 and 4′‐(4‐aminophenyl)‐2,2′:6,2″‐terpyridine 2 with 80% yield. MALDI–TOF spectroscopy indicated a maximum degree of polymerization of 14, the most abundant species being the pentamer and the hexamer. P1‐2 is highly fluorescent in solution. The emission maximum in chloroform is 510 nm, and the quantum yield Φf is 55%. UV/Vis titration of P1‐2 with zinc acetate and iron(II) perchlorate indicates formation of metal–terpyridine (tpy) 1:2 (bis)complexes. Since formation of the (bis)complex is accompanied by cross‐linking, the polymer slowly precipitates, especially in non‐polar solvents. Comparative titration of monomer 2 with zinc acetate proceeds under sharp increase of photoluminescence intensity until a metal–tpy 2:1 ratio is reached. We assume the formation of two zinc (mono)complexes, one with the tpy and the other one with the amino group of 2. CV analysis of P1‐2 in acetonitrile indicates three quasi‐reversible oxidation processes with mid‐potentials of 0.45, 0.50 and 0.95 V versus SCE due to oxidation of the backbone nitrogen atoms, while the reduction at −2.6 V is irreversible. The strong ionochromism renders P1‐2 useful as highly sensitive and specific fluorimetric chemosensor.

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Dilatometry: A Tool to Measure the Influence of Cooling Rate and Pressure on the Phase Behavior of Nucleated Polypropylene
Authors: Housmans Jan‐Willem , Balzano Luigi , Adinolfi Monica , Peters Gerrit W. M. , Meijer Han E. H.
Published: March 2009

The pressure and cooling rate dependence of the phase diagram of isotactic polypropylene (iPP) with the nucleating agent 1,3:2,4‐bis(3,4‐dimethylbenzylidene)‐sorbitol (DMDBS) is investigated. A custom designed dilatometer is used to measure the specific volume of the blends for a wide range of cooling rates and elevated pressures. The crystallization line in the phase diagram shifts to higher temperatures with increase in the pressure and decrease in the cooling rate, independent of the concentration. The influence of cooling rate and pressure is related to the final morphology determined from X‐ray diffraction. Dilatometry can be used as an interesting alternative to extract information on the phase behavior and crystallinity, for conditions hard or not at all obtainable with standard techniques like DSC or SALS.

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Fluorene‐Based Copolymers Containing Dinaphtho‐s‐indacene as New Building Blocks for High‐Efficiency and Color‐Stable Blue LEDs
Authors: Guo Xin , Cheng Yanxiang , Xie Zhiyuan , Geng Yanhou , Wang Lixiang , Jing Xiabin , Wang Fosong
Published: March 2009

By incorporating a new building block, 7,7,15,15‐tetraoctyldinaphtho‐s‐indacene (NSI), into the backbone of poly(9,9‐dioctylfluorene) (PFO), a novel series of blue light‐emitting copolymers (PFO‐NSI) have been developed. The insertion of the NSI unit into the PFO backbone leads to the increase of local effective conjugation length, to form low‐energy fluorene–NSI–fluorene (FNF) segments that serve as exciton trapping sites, to which the energy transfers from the high‐energy PFO segments. This causes these copolymers to show red‐shifted emissions compared with PFO, with a high efficiency and good color stability and purity. The best device performance with a luminance efficiency of 3.43 cd · A−1, a maximum brightness of 6 539 cd · m−2, and CIE coordinates of (0.152, 0.164) was achieved.

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Propylene Polymerization Performance of Isolated and Aggregated Ti Species Studied Using a Well‐Designed TiCl3/MgCl2 Ziegler‐Natta Model Catalyst
Authors: Wada Toru , Taniike Toshiaki , Kouzai Iku , Takahashi Shougo , Terano Minoru
Published: March 2009

In propylene polymerization with MgCl2‐supported Ziegler‐Natta catalysts, it is known that the reduction of TiCl4 with alkylaluminum generates Ti3+ active species, and at the same time, leads to the growth of TiClx aggregates. In this study, the aggregation states of the Ti species were controlled by altering the Ti content in a TiCl3/MgCl2 model catalyst prepared from a TiCl3 · 3C5H5N complex. It is discovered that all the Ti species become isolated mononuclear with a highly aspecific feature below 0.1 wt.‐% of the Ti content, and that the isolated aspecific Ti species are more efficiently converted into highly isospecific ones by the addition of donors than active sites in aggregated Ti species.

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The Sod2 mutant mouse as a model for oxidative stress: A functional proteomics perspective
Authors: Lee Yie Hou , Lin Qingsong , Boelsterli Urs A. , Chung Maxey C.M.
Published: March 2009

Oxidative stress has been implicated in the pathogenesis of numerous human diseases and disorders, but the mechanistic basis often remains enigmatic. The Sod2 mutant mouse, which is sensitized to mitochondrial stress, is an ideal mutant model for studying the role of oxidative stress in a diverse range of complications arising from mitochondrial dysfunction and diminished antioxidant defense. To fully appreciate the widespread molecular consequences under increased oxidative stress, a systems approach utilizing proteomics is able to provide a global overview of the complex biological changes, which a targeted single biomolecular approach cannot address fully. This review focuses on the applications of mass spectrometry and functional proteomics in the Sod2 mouse. The combinatorial approach provides novel insights into the interplay of chemistry and biology, free radicals and proteins, thereby augmenting our understanding of how redox perturbations influence protein dynamics. Ultimately, this knowledge can lead to the development of free radical‐targeted therapies. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:179–196, 2010
Macromol. React. Eng. 2–3/2009
Authors: Yi Qingfeng , Fan Guoqiang , Wen Xiaojing , Dong Jin‐Yong , Han Charles C.
Published: March 2009

Back Cover: Cascade process, consisting of a metallocene‐type coordination polymerization and atom transfer radical polymerization, is described for preparation of isotactic polypropylene (i‐PP)‐based polar block copolymers. Further details can be found in the article by Q. Yi, G. Fan, X. Wen, J.‐Y. Dong,* C. C. Han on page 91.
Alterations to the protein profile of bladder carcinoma cell lines induced by plant extract MINA‐05 in vitro
Authors: Nguyen‐Khuong Terry , White Melanie Y. , Hung Tzong‐Tyng , Seeto Shona , Thomas Melissa L. , Fitzgerald Anna M. , Martucci Carlos E. , Luk Sharon , Pang Shiu‐Fu , Russell Pamela J. , Walsh Bradley J.
Published: March 2009

Bladder cancer (BLCa) is a severe urological cancer of both men and women that commonly recurs and once invasive, is difficult to treat. MINA‐05 (CK Life Sciences Int'l, Hong Kong) is a derivative of complex botanical extracts, shown to reduce cellular proliferation of bladder and prostate carcinomas. We tested the effects of MINA‐05 against human BLCa cell sublines, B8, B8‐RSP‐GCK, B8‐RSP‐LN and C3, from a transitional cell carcinoma, grade IV, to determine the molecular targets of treatment by observing the cellular protein profile. Cells were acclimatised for 48 h then treated for 72 h with concentrations of MINA‐05 reflecting ${1 \over 2}$ IC50, IC50 and 2×IC50 (n = 3) or with vehicle, (0.5% DMSO). Dose‐dependant changes in protein abundance were detected and characterised using 2‐dimensional electrophoresis and MS. We identified 10 proteins that underwent changes in abundance, pI and/or molecular mass in response to treatment. MINA‐05 was shown to influence proteins across numerous functional classes including cytoskeletal proteins, energy metabolism proteins, protein degradation proteins and tumour suppressors, suggesting a global impact on these cell lines. This study implies that the ability of MINA‐05 to retard cellular proliferation is attributed to its ability to alter cell cycling, metabolism, protein degradation and the cancer cell environment.
Proteomic analysis of low dose arsenic and ionizing radiation exposure on keratinocytes
Authors: Berglund Susanne R. , Santana Alison R. , Li Dan , Rice Robert H. , Rocke David M. , Goldberg Zelanna
Published: March 2009

Human exposure to arsenic and ionizing radiation (IR) occur environmentally at low levels. While the human health effects of arsenic and IR have been examined separately, there is little information regarding their combined effects at doses approaching environmental levels. Arsenic toxicity may be affected by concurrent IR especially given their known individual carcinogenic actions at higher doses. We found that keratinocytes responded to either low dose arsenic and/or low dose IR exposure, resulting in differential proteomic expression based on 2‐DE, immunoblotting and statistical analysis. Seven proteins were identified that passed a rigorous statistical screen for differential expression in 2‐DE and also passed a strict statistical screen for follow‐up immunoblotting. These included: α‐enolase, epidermal‐fatty acid binding protein, heat shock protein 27, histidine triad nucleotide‐binding protein 1, lactate dehydrogenase A, protein disulfide isomerase precursor, and S100A9. Four proteins had combined effects that were different than would be expected based on the response to either individual toxicant. These data demonstrate a possible reaction to the combined insult that is substantially different from that of either separate treatment. Several proteins had different responses than what has been seen from high dose exposures, adding to the growing literature suggesting that the cellular responses to low dose exposures are distinct.
Nitromatrix provides improved LC‐MALDI signals and more protein identifications
Authors: Kouvonen Petri , McDonnell Liam A. , Heeren Ron M. A. , Corthals Garry L.
Published: March 2009

The beneficial use of NC in MALDI‐MS has previously been reported to provide better S/N and reproducibility as well as less alkali metal adducts. We have therefore investigated if additional beneficial properties of NC also existed for commonly employed proteomics‐based LC‐MALDI procedures. Specifically we studied the effects of NC as a matrix cofactor for prestructured sample supports (AnchorChip plates), and compared the performance with several alternative sample preparation methods recently reported in the literature. The work reported here describes a new method of mixing the NC‐matrix solution with the LC‐eluent prior to sample deposition and shows that a mixture of CHCA and NC in a complex solvent offers superior analytical results in several ways: most striking is the higher signal intensity, and that the signals last much longer, due to the robustness of the matrix formulation. We have tested the use of the nitromatrix on a single LC‐MALDI preparation and found that at least ten reiterative analyses could be performed, resulting in total analysis times of more than 75 h (approximately 15 million laser shots). Consequently more than twice as many proteins could be identified than from a single analysis. This combination of longer, and stronger, MALDI signals provided an increase in the number of peptides, greater sequence coverage in MS/MS experiments and ultimately more confident peptide assignments.
Plasma‐Polymerization of HMDSO Using an Atmospheric Pressure Dielectric Barrier Discharge
Authors: Morent Rino , De Geyter Nathalie , Jacobs Tinneke , Van Vlierberghe Sandra , Dubruel Peter , Leys Christophe , Schacht Etienne
Published: March 2009

In this work, an atmospheric pressure glow‐like dielectric barrier discharge in argon with small admixtures of hexamethyldisiloxane (HMDSO) is employed for the deposition of thin polydimethylsiloxane (PDMS) films. The effect of discharge power and feed composition (monomer concentration) on film properties has been investigated by means of contact angle measurements, Fourier‐Transform Infrared Spectroscopy (FT‐IR), and Atomic Force Microscopy (AFM). The results are described by defining a W/FM value, where W is the discharge power, F the monomer flow rate, and M is the molecular weight of the monomer. This paper shows that the deposition rate and the chemical composition of the deposited films are strongly affected by the W/FM value at which plasma‐polymerization is performed.
Persistent proteomic alterations in the medial prefrontal cortex with abstinence from cocaine self‐administration
Authors: Lull Melinda E. , Erwin Mandi S. , Morgan Drake , Roberts David C. S. , Vrana Kent E. , Freeman Willard M.
Published: March 2009

Neuroproteomic studies of drug abuse offer the potential for a systems‐level understanding of addiction. Understanding cocaine‐responsive alterations in brain protein expression that persist even with extended abstinence may provide insight into relapse liability. In the current study, protein changes in the medial prefrontal cortex of cocaine self‐administering rats following 1 and 100 days of enforced abstinence were quantified by 2‐D DIGE. We have previously reported increased drug‐seeking and drug‐taking, as well as mRNA and epigenetic changes in this model even after 100 days of enforced abstinence. A number of statistically significant changes in proteins relating to synapse function and neuronal remodeling were evident, including neurofilament medium and Hsp73, which increased at 1 day of abstinence, but returned to normal levels following 100 days of abstinence. Dynamin‐1 and synaptosome‐associated protein 25 kDa (SNAP‐25) were unchanged at 1 day of abstinence, but were significantly decreased after 100 days. These data demonstrate that while some protein changes return to normal levels following enforced cocaine abstinence, a number remain or become altered after long periods, up to 100 days, of cocaine abstinence. Those protein expression changes that do not reset to pre‐cocaine exposure levels may contribute to the persistent relapse potential that occurs in response to cocaine abstinence.
Non‐DMS related ferromagnetism in transition metal doped zinc oxide
Authors: Potzger Kay , Zhou Shengqiang
Published: March 2009

We review pitfalls in recent efforts to make a conventional semiconductor, namely ZnO, ferromagnetic by means of doping with transition metal ions. Since the solubility of those elements is rather low, formation of secondary phases and the creation of defects upon low temperature processing can lead to unwanted magnetic effects. Among others, ion implantation is a method of doping, which is highly suited for the investigation of those effects. By focussing mainly on Fe, Co or Ni implanted ZnO single crystals we show that there are manifold sources for ferromagnetism in this material which can easily be confused with the formation of a ferromagnetic diluted magnetic semiconductor (DMS). We will focus on metallic as well as oxide precipitates and the difficulties of their identification. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Large predators and biogeochemical hotspots: brown bear (Ursus arctos) predation on salmon alters nitrogen cycling in riparian soils
Authors: Holtgrieve Gordon W. , Schindler Daniel E. , Jewett Peter K.
Published: March 2009

Two important themes in ecology include the understanding of how interactions among species control ecosystem processes, and how habitats can be connected through transfers of nutrients and energy by mobile organisms. An impressive example of both is the large influx of nutrients and organic matter that anadromous salmon supply to inland aquatic and terrestrial ecosystems and the role of predation by brown bears (Ursus arctos) in transferring these marine‐derived nutrients (MDN) from freshwater to riparian habitats. In spite of the recognition that salmon‐bear interactions likely play an important role in controlling the flux of MDN from aquatic to riparian habitats, few studies have linked bear predation on salmon to processes such as nitrogen (N) or carbon (C) cycling. We combine landscape‐level survey data and a replicated bear‐exclosure experiment to test how bear foraging on salmon affects nitrous oxide (N2O) flux, carbon dioxide (CO2) flux, and nutrient concentrations of riparian soils. Our results show that bears feeding on salmon increased soil ammonium (NH4+) concentrations three‐fold and N2O flux by 32‐fold. Soil CO2 flux, nitrate (NO3−), and N transformation differences were negligible in areas where bears fed on salmon. Reference areas without concentrated bear activity showed no detectable change in soil N cycling after the arrival of salmon to streams. Exclosure experiments showed that bear effects on soil nutrient cycles were transient, and soil N processing returned to background conditions within 1 year after bears were removed from the system. These results suggest that recipient ecosystems do not show uniform responses to MDN inputs and highlight the importance of large mobile consumers in generating landscape heterogeneity in nutrient cycles.
CYP46A1variants influence Alzheimer’s disease risk and brain cholesterol metabolism
Authors: Kölsch Heike , Lütjohann Dieter , Jessen Frank , Popp Julius , Hentschel Frank , Kelemen Peter , Schmitz Sandra , Maier Wolfgang , Heun Reinhard
Published: March 2009

Background

Cholesterol 24S-hydroxylase (CYP46) catalyzes the conversion of cholesterol to 24S-hydroxycholesterol, the primary cerebral cholesterol elimination product. Only few gene variations in CYP46 gene (CYP46A1) have been investigated for their relevance as genetic risk factors of Alzheimer’s disease (AD) and results are contradictory.

Methods

We performed a gene variability screening inCYP46A1and investigated the effect of gene variants on the risk of AD and on CSF levels of cholesterol and 24S-hydroxycholesterol.

Results

Two of the identified 16 SNPs inCYP46A1influenced AD risk in our study (rs7157609:p= 0.016; rs4900442:p= 0.019). The interaction term of both SNPs was also associated with an increased risk of AD (p= 0.006). Haplotypes including both SNPs were calculated and haplotype G–C was identified to influence the risk of AD (p= 0.005). AD patients and non-demented controls, who were carriers of the G–C haplotype, presented with reduced CSF levels of 24S-hydroxycholesterol (p= 0.001) and cholesterol (p< 0.001).

Conclusion

Our results suggest thatCYP46A1gene variations might act as risk factor for AD via an influence on brain cholesterol metabolism.
The Cambridge Companion to Orthodox Christian Theology
Authors: Theokritoff Elizabeth
Published: March 2009

Orthodox Christian theology is often presented as the direct inheritor of the doctrine and tradition of the early Church. But continuity with the past is only part of the truth; it would be false to conclude that the eastern section of the Christian Church is in any way static. Orthodoxy, building on its patristic foundations, has blossomed in the modern period. This volume focuses on the way Orthodox theological tradition is understood and lived today. It explores the Orthodox understanding of what theology is: an expression of the Church's life of prayer, both corporate and personal, from which it can never be separated. Besides discussing aspects of doctrine, the book portrays the main figures, themes and developments that have shaped Orthodox thought. There is particular focus on the Russian and Greek traditions, as well as the dynamic but less well-known Antiochian tradition and the Orthodox presence in the West.
Hydrodynamic theory of drift Kelvin–Helmholtz instabilities
Authors: Mikhailovskii A. B.
Published: March 2009

The hydrodynamic theory of drift Kelvin-Helmholtz instabilities is discussed. It is shown that the hydrodynamic approach gives, in the region of its applicability, the same results as the kinetic one. Previous studies on the hydrodynamic theory of drift Kelvin-Helmholtz instabilities are analysed. It is shown that certain parts of these studies are incorrect. Reasons for this are discussed.
Thermal conductivity in a laser-created plasma heated by inverse bremsstrahlung absorption
Authors: Balescu R.
Published: March 2009

The heat conductivity of a laser-created plasma heated by inverse bremsstrahlung absorption is investigated in the vicinity of a self-similar state (SSS), taken as reference state. Under certain conditions, the slowly varying macroscopic quantities obey true, local hydrodynamical equations and a well-defined, positive, heat conductivity exists. The latter is strongly time-dependent through the unperturbed temperature. Its value, compared to the classical heat conductivity at the same temperature, shows a reduction of about 20%. It is shown that, for high intensities and/or long wavelengths, the linear heat conduction theory necessarily breaks down, even if the temperature gradient is very small.
Wave propagation in the presence of a spatially uniform external periodic magnetic field in two-temperature plasma
Authors: Ghosh Sanjay Kumar
Published: March 2009

Starting from the two-fluid model hydrodynamic equations, a dispersion relation is obtained for wave propagation through a two-temperature plasma perpendicular to the direction of the spatially uniform external magnetic field B0cosω0t and several excitation conditions are deduced.
Stability of a positive column in the presence of an axial magnetic field
Authors: Uberoi Mahinder S. , Chow Chuen-Yen
Published: March 2009

Self-consistent infinitesimal perturbations of electron density and electric field are used to analyse the stability of the plasma. The axisymmetric perturbations are stable for any magnetic and electric field strengths. The non-axisymmetric perturbations with azimuthal modes m ≥ 1 and less than a certain integer are unstable for certain ranges of magnetic and electric fields. The mode m = 2 can be more unstable than the mode m = 1. Previous analysis by other authors was confined to the case m = 1 and the perturbations were not self-consistent. Our results differ significantly from the earlier results.
Decay of the lower-hybrid wave into an ion cyclotron mode and a whistler wave
Authors: Saxena M. K.
Published: March 2009

The electrostatic lower-hybrid wave is shown to decay parametrically into a whistler wave and a resonant ion cyclotron mode or an ion cyclotron quasi-mode or a reactive quasi-mode. The convective threshold powers for these decay instabilities are found to be much larger than presently available pump powers. These decay instabilities, however, are expected to play an important role in the saturation of the parametrically excited short-wavelength lower-hybrid waves having frequency close to ωlh.
Nonlinear transient signal propagation in homogeneous plasma
Authors: Jovanović D. , Pécseli H. L. , Thomsen K.
Published: March 2009

The nonlinear transient evolution of a suddenly applied monochromatic wave in a homogeneous plasma is considered, with particular emphasis on the magnetized case, where ordinary and extraordinary electromagnetic waves travelling normal to B are treated. Two important features are described. First, the penetration of the wave front is shown to be accompanied by ‘radiation’ of low-frequency waves, of which ion cyclotron and lower-hybrid waves are considered here. Next, the presence of a nonlinear, second-harmonic precursor is predicted, containing two natural modes of oscillation, one with exactly twice the frequency of the fundamental, and the other a slightly frequency-shifted contribution. The analysis is readily generalized to waves other than those considered here.
Constitutive relation for slowly varying warm plasmas
Authors: Suchy Kurt
Published: March 2009

Ohm's law for homogeneous warm plasmas not varying with time is generalized for plasmas with parameters slowly varying in space and time. The corresponding integral constitutive relation is derived.
A linear and quasi-linear investigation of the crossfield current-driven ion-acoustic instability
Authors: Bharuthram R. , Hellberg M. A.
Published: March 2009

The linear growth rate of the crossfield current-driven ion-acoustic instability is obtained for any equilibrium particle velocity distribution function of the type . Quasi-linear theory is then used to investigate the saturation of the instability. Several associated features, namely, particle diffusion in velocity space, anomalous resistivity, energy distribution and electron and ion heating rates are evaluated for a Maxwellian distribution. Finally, a brief comparison is made with the heating rates associated with the electron cyclotron drift instability.
Fast magnetic field-line reconnexion in a compressible fluid. Part 1. Coplanar field lines
Authors: Soward A. M. , Priest E. R.
Published: March 2009

The Petschek model for incompressible reconnexion has been put on a firm mathematical foundation in an earlier paper by Soward & Priest, who discovered a ‘local’ similarity solution for the process. The present paper extends that analysis to compressible reconnexion, in which the previous Alfvén waves are replaced by slow magneto-acoustic shocks of switch-off type. By contrast with a previous suggestion, it is found unnecessary to include intermediate waves standing ahead of the slow shocks. The maximum reconnexion rate is typically half of Petschek's stated value, though faster rates are achieved when the external gas pressure is sufficiently low.
Fast magnetic field-line reconnexion in a compressible fluid. Part 2. Skewed field lines
Authors: Soward A. M.
Published: March 2009

Petschek's model of compressible reconnexion developed in part 1 is extended to include an additional transverse magnetic field. Part of the incoming Poynting flux is degraded into kinetic energy at an intermediate wave (rotational) discontinuity. Yet more is degraded into heat and kinetic energy at a slow shock lying downstream of it. Everywhere downstream of the rotational discontinuity, the transverse magnetic field exceeds its upstream value. As a result, the total release of magnetic energy from the antiparallel components of the incoming magnetic field calculated in part 1 is decreased by a factor lying between a half and unity. The weak radial inhomogeneity exemplified by the ‘local’ similarity solution is determined by consideration of the fast and slow magneto-acoustic and Alfvén waves emitted at the neutral point. The Alfvén waves lead to a weak singularity in the vicinity of the rotational discontinuity, while a similar singularity is found in the vicinity of the outflow axis of symmetry associated with an entropy wave.
Generalized expressions for momentum and energy losses of charged particle beams in non-Maxwellian multi-species plasmas and spherical symmetry
Authors: Cuperman S. , Weiss I. , Dryer M.
Published: March 2009

Generalized expressions for the rates of change of the momentum, energy and thermal anisotropy of fast, charged particle beams interacting with non-Maxwellian multi-species plasmas are derived. The results hold for the case of spherically symmetric systems and, therefore, are relevant for inertial confinement fusion schemes driven by fast charged particle beams and for various astro-physical situations. The calculations are based on the Fokker-Planckformalism. The effects connected with the departures from the Maxwellian distribution functions are expressed in terms of their fifth moments, , which reflect the role of the non-Maxwellian tails. The familiar stopping power expression holding for Maxwellian targets is recovered as a particular case.
Energy transfer in magnetized plasmas
Authors: Nocera L.
Published: March 2009

An extension of the method of characteristics for parabolic equations is proposed that allows the integration of the energy equation for a static, heated and radiating, heat-conducting, optically thin plasma in a magnetic field. The invariance of all physical quantities is assumed, throughout the work, to occur along an arbitrary curvilinear direction. Finally, an example is presented to illustrate how the algorithm actually works.
The orbits of electrons and ions in a rotating magnetic field
Authors: Hugrass Waheed N. , Jones Ieuan R.
Published: March 2009

The motion of electrons and ions in a system which consists of a uniform rotating magnetic field and a steady uniform magnetic field which is aligned with the axis of rotation is re-examined. Stable orbits are identified and explicit expressions for these orbits are provided. The more realistic situation of motion in the non-uniform self-consistent fields appropriate to a cylindrical plasma equilibrium maintained by the rotating field is investigated. Again, stable orbits are found. The stability of orbits in this more complex situation is examined using an equivalent potential concept.
On reflexion and trapping of upper-hybrid waves
Authors: Mjølhus Einar
Published: March 2009

The theme of the paper is the relation between the so-called Z mode and the upper-hybrid wave in a magnetized plasma. First, certain problems as to reflexion and transmission of upper-hybrid waves at quasi cut-off (that is, cut-off predicted within electrostatic approximation) are stated and solved by singular perturbation technique. Then the theory is extended to a problem concerning generation and trapping of upper-hybrid waves in magnetic field aligned electron density irregularities. First a single density depression is considered, and then the formalism is further extended to a system of many parallel density depressions. The study was motivated by problems in the theory of artificial small-scale ionospheric irregularities occurring in radio wave experiments.
Magnetosonic wave propagation in the mode conversion regime
Authors: Lapierre Y.
Published: March 2009

The propagation of the fast magnetosonic wave is studied, taking into account the effect of the two-ion hybrid layer. Using a one-dimensional model, which includes density and magnetic field gradients, the wave equation is solved in the cold plasma approximation. The existence of radial eigenmodes confined between the two-ion hybrid layer and the low field side wall is predicted. Comparison with experimental data obtained on the TFR tokamak confirms the theoretical conclusions. Toroidal eigenmodes are observed even in the mode conversion regime when the antenna is on the low magnetic field side.