bluuebunny/crossref_metadata_2025 huggingface dataset:
Top‐down approach to studying biological components using ToF‐SIMS
Authors: Piwowar Alan , Fletcher John , Lockyer Nicholas , Vickerman John
Published: May 2010

We present in this article a novel approach to identifying subcellular components from spectral images collected with ToF‐SIMS. The method utilizes a separation technique to isolate and enrich cellular fractions which are then examined with ToF‐SIMS to identify peak or peak ratio markers to assign reference spectra. The ultimate aim of the project is to utilize these reference spectra to identify cellular components from spectral images. We present data from three such extracts (nuclei, cytosol and membrane‐bound organelles) which confirms that characteristic spectral differences do exist between these systems. These results indicate that such a ‘top‐down’ approach to subcellular analysis can aid cellular imaging with ToF‐SIMS. Copyright © 2010 John Wiley & Sons, Ltd.
Sputtered molecular fluoride anions: HfFn− and WFn−
Authors: Gnaser Hubert , Golser Robin
Published: May 2010

The emission of negatively charged HfFn− (n ≤ 5) and WFn− (n ≤ 7) molecular ions sputtered from a mixed HfWPbF2 fluoride sample by a 13 keV Cs+ ion beam was studied. The emitted ions were detected in a high‐sensitivity double‐focusing secondary ion mass spectrometer. In the HfFn− and WFn− series, HfF5− and WF6− are the anions formed most abundantly, with their ratio amounting to HfF5−/WF6−∼6, whereas HfF5−/WF5−∼18. In particular, the rather high yield of the HfF5− anion could be essential for the sensitive detection of live 182Hf, a radionuclide (half‐live ∼9 million years) that might originate from stellar events in the vicinity of the Earth. Generally, these high ion yields appear to correspond with a high electron affinity of the respective molecule. In addition, their formation may be affected by the atomic composition at the sputtering site. Because their constituents originate from (initially) separated sources (the individual Hf, W and PbF2 particles), the production of the HfFn− and WFn− molecular anions is envisaged to require an extensive mixing between these different reservoirs during sputtering. Furthermore, the energy distributions of these molecular anion species indicate that they are released from the surface via a collision cascade that also leads to the occurrence of fragmentation processes in the emission event. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of thin oxide film on protein sample measurement with TOF‐SIMS
Authors: Aoyagi Satoka , Inoue Masae , Mitsuoka Takuya
Published: May 2010

Recently, the biomaterial field has become one of the most important applications of time of flight (TOF) SIMS time‐of‐flight secondary ion mass specmetry (TOF‐SIMS). Although TOF‐SIMS can be applied to insulating samples, electrically conductive substrates such as Si, Au plates and indium‐tin oxide (ITO) glass plates are more useful to detect fragment ions from biomaterials. ITO glass and silicon substrates are often employed for the preparation of biomaterial samples instead of glass plates. In this study, an ITO glass plate and silicon plates with various thicknesses of silicon oxide thin film were compared to investigate the most suitable sample preparation conditions for evaluating protein samples using TOF‐SIMS. Four kinds of substrates, an ITO glass plate, a silicon plate, a silicon plate with an oxide film of 50 nm, and another of 250 nm, were employed as substrates to adsorb a model protein, egg white lysozyme. Each sample was measured five times with TOF‐SIMS with a gallium ion source under static conditions. The TOF‐SIMS spectra of each sample were compared to evaluate the effect of thin oxide films on protein measurement with TOF‐SIMS. The specific peaks of each sample related to lysozyme in the positive ion spectra were selected in comparison to their control samples. As a result, TOF‐SIMS spectra of the silicon plate with a 50 nm silicon oxide film showed the most specific peaks related to lysozyme. In addition, TOF‐SIMS spectra of the ITO sample showed many peaks of fragment ions related to lysozyme in a high‐mass range at which the other samples do not show adequate peaks. Thus, both substrates with the oxide films, silicon oxide and ITO, displayed better results than the silicon plate sample. Copyright © 2010 John Wiley & Sons, Ltd.
Development of a TOF‐SIMS technology as a predictive tool for the needs of the mineral processing industry
Authors: Hart Brian R. , Dimov Stamen S. , Smart Roger St. C.
Published: May 2010

Recently, upgrades towards a semiquantitative approach to mineral processing applications using the time of flight (TOF) SIMS (TOF‐SIMS) technique have been developed and implemented. Secondary ion yield at specific instrument parameters for matrix elements in the predominant ore minerals and their comparative normalization factors have been determined. Surface loading quantification for Cu on a variety of ore minerals has shown that signal intensity variability is related to the substrate matrix. Relative sensitivity factors for component loading have been determined and calibration curves for Cu loading on mineral surfaces have established with lower limits of detection in the range of 10 ppm.

Given the new semiquantitative approach for surface characterization of minerals, a new test was developed to be used as a predictive tool in mineral flotation separation. The test protocol involved a two‐chamber ball mill where Cu transfer between the pulp and specimen surface was measured by the semiquantitative TOF‐SIMS approach. The test was applied to 13 ores. The reported experimental data on these ores demonstrated the ability of this technique to differentiate Cu transfer over a large dynamic range. The data also demonstrated that the surface loading of Cu on pyrite can be correlated, in some cases, with mineralogy. In others, however, the surface Cu loading observed is not congruent with the mineralogical assessment of the ore sample, but still linked with flotation behavior. This shows that the test could be used with mineralogy to better benchmark a sample before embarking on a flotation flowsheet development programme. Copyright © 2010 John Wiley & Sons, Ltd.
Speciation and quantification of surface gold in carbonaceous matter by TOF‐SIMS: a new approach in characterizing losses during the gold recovery process
Authors: Dimov S. S. , Hart B. R.
Published: May 2010

An increasing number of low‐grade gold ore deposits are characterized by the presence of gold as solid solution into the mineral matrix of sulphide minerals which is not directly amenable to gold cyanidation. In order to liberate this submicroscopic gold the ore has to be oxidized before being subjected to gold cyanidation and exctraction. This is mainly done by autoclave pressure oxidation (AC POX) or roasting, two major technologies used by the mining industry. Very often, these ores contain an active carbonaceous compound which has the ability to adsorb, or preg‐rob gold from the cyanide solution. Gold recovery can be adversely affected by preg‐robbing on inherent carbonaceous material during autoclave pressure oxidation of sulphide ores.

The time of flight (TOF) SIMS (TOF‐SIMS) technique has been applied for direct determination of gold species on individual carbonaceous particulates from AC POX stream samples. The speciation of the gold preg‐robbed on carbonaceous matter from CIL tail sample showed presence of both metallic gold and Au(CN)2 compound. Direct quantification of the metallic and compound gold provided an estimate for the fraction of gold losses due to preg‐robbing in carbonaceous matter. Copyright © 2010 John Wiley & Sons, Ltd.
Predictors of subjective ratings of stressor severity: the effects of current mood and neuroticism
Authors: Espejo Emmanuel P. , Ferriter Caitlin T. , Hazel Nicholas A. , Keenan‐Miller Danielle , Hoffman Lindsay R. , Hammen Constance
Published: May 2010

Respondent‐based or subjective, ratings of stressor severity are posited to be influenced by systematic biases related to current mood and trait neuroticism which may confound associations between environmental stressors and psychological outcomes. The current study examined the effects of current mood state and neuroticism on subjective ratings of severity for real‐life stressors in a sample of 76 (30 males) undergraduates. Subjective ratings of stressor severity were collected in the context of an interview‐based stress assessment and were assessed on two separate occasions. Changes in mood state across the two assessments did not correspond with changes in subjective ratings of stressor severity. Neuroticism independently predicted subjective ratings of stressor severity, as did female gender and investigator‐based ratings of objective stressor severity. In addition, there was evidence to suggest that neuroticism fully accounted for observed associations between current mood state and subjective ratings of stressor severity. The findings are discussed with regard to the potential confounding influence of neuroticism in studies that rely on respondent‐based ratings of stressor severity in predicting psychological outcomes. Copyright © 2010 John Wiley & Sons, Ltd.
Absence of direct effects on the dopamine D2 receptor by mGluR2/3‐selective receptor agonists LY 354,740 and LY 379,268
Authors: Zysk John R. , Widzowski Dan , Sygowski Linda A. , Knappenberger Katharine S. , Spear Nathan , Elmore Charles S. , Dorff Peter , Liu Hongyan , Doherty James , Chhajlani Vijay
Published: May 2010

We previously reported the absence of high‐affinity binding of the group II metabotropic glutamate receptor agonists LY 354,740 and LY 379,268 to the D2L dopamine receptor. A rebuttal to our findings has since been reported (seeIntroductionsection); this study represents our response. Analysis by LCMS of LY 354,740 and LY 379,268 used in this study revealed the correct molecular mass for these compounds. Both LY 354,740 and LY 379,268 exhibited potent agonist activity for mGluR2in the35S‐GTPγS assay. Functionally, neither compound displayed antagonist activity in the GTPγS assay with recombinant D2. At concentrations up to 10 μM, both compounds failed to displace [3H]‐raclopride, [3H]‐PHNO, or [3H]‐domperidone in filter‐binding assays under isotonic (120 mM NaCl orN‐methyl glucamine) or low‐ionic strength (no NaCl orN‐methyl glucamine) conditions. Some displacement of [3H]‐domperidone (20–40%) was observed at 30 μM of LY 354,740 under low‐ionic strength and under isotonic conditions in the absence of NaCl. No displacement of [3H]‐domperidone was detected in a two site model at lower (<100 nM) concentrations of either compound. Moreover, no D2activity was observed for LY 354,740 or LY 379,268 in the CellKey™ (cellular dielectric spectroscopy) assay. In this communication, we discuss the possible reasons for differences in our study and the previously published work and implications of these studies for mechanisms of antipsychotic action. Synapse 65:64–68, 2011. © 2010 Wiley‐Liss, Inc.
Hysterectomy or a minimal invasive alternative? A systematic review on quality of life and satisfaction
Authors: Brölmann H. A. M. , BijdeVaate A. J. , Vonk Noordegraaf A. , Janssen P. F. , Huirne J. A. F.
Published: May 2010

Nowadays, an increasing number of minimal invasive treatment alternatives to hysterectomy may be offered to the patient. In determining the appropriate treatment option, the patient has a distinct dilemma if a minimal invasive treatment with lesser effect than hysterectomy should be chosen or if a hysterectomy should be chosen which is a major surgery and requires longer recovery than the minimal invasive alternative. Quality-of-life (QoL) questionnaires that take subjective health perception into account are currently used to assess the treatment effects. The objective of this literature study is to determine and discuss the role of QoL as an outcome in randomized controlled trials (RCT) or systematic reviews of RCTs that study the treatment effect of hysterectomy compared to that of minimal invasive alternatives. A systematic literature search was performed in the PubMed database and in the Cochrane database to find randomized trials and systematic reviews of randomized trials, comparing hysterectomy with minimal invasive or conservative treatment options with sufficient follow-up using satisfaction, health status, and quality of life as outcomes. The results were based on nine randomized trials and two systematic reviews. The differences are mostly in favor of hysterectomy. In two out of four studied treatment alternatives, the satisfaction or health status is different in favor of hysterectomy while the QoL is equivalent. After 2 years of follow-up, differences between both groups have disappeared, possibly because of the crossover effect. Possible reasons for the lesser response of QoL compared to satisfaction or health status are discussed. The fundamental question if patients have a better quality of life at all times if they choose for a minimal invasive alternative of hysterectomy remains unresolved. Information, individualization, and freedom of choice before surgery probably best serve the sense of well being and quality of life thereafter.
Chopin’s Deadly Awakening—An Analysis of the Women Characters in The Awakening
Authors: Xueling WU
Published: May 2010

Chopin gives us answer through her treatment with the three women characters in The Awakening. Like a new-born child, Edna begins to explore her real identity in the new world after she awakens from a long sleep. She does not realize that she has no power to motivate man to help her achieve her dream. The other female character worth mentioning is Adele—a seemingly perfect woman in that society. The next female character is Mademoiselle Reisz. She is an independent artist-woman. All of the three women just reflect Chopin’s awakening of women’s social identity and her confusion with the choice of life. That is also why Chopin just leaves us an open ending in this novel. All of the three women just reflect Chopin’s awakening of women’s social identity and her confusion with the choice of life. That is also why Chopin just leaves us an open ending in this novel.
Drogenkonsum von Studierenden – Ergebnisse des Gesundheitssurveys NRW
Authors: Helmer Stefanie , Mikolajczyk Rafael , Meier Sabine , Krämer Alexander
Published: May 2010

Einleitung

Der Studienbeginn leitet eine neue Lebensphase ein: neue Freiheiten, neue Pflichten und neue Lebensstilentscheidungen. Die Daten des Gesundheitssurvey für Studierende in NRW zeigen, dass Studierende beiderlei Geschlechts ähnlich viel rauchen, aber weniger als gleichaltrige Studierende, die vor zehn Jahren befragt wurden. Darüber hinaus zeigen die Daten des Surveys, dass männliche Studierende häufiger und exzessiver Alkohol trinken und einen höheren Konsum von Marihuana aufweisen, als die weiblichen Studierenden.
Sucht und Armut: epidemiologische Zusammenhänge und präventive Ansätze
Authors: Henkel Dieter
Published: May 2010

Einleitung

In Deutschland leben 15% der Bevölkerung in Einkommensarmut. Berichtet wird darüber, wie stark Suchtprobleme (Tabak, Alkohol, illegale Drogen) in der Armutsbevölkerung verbreitet sind, und welche armutsbezogenen suchtpräventiven Ansätze möglich wären.
Bioavailability of strawberry antioxidants in human subjects
Authors: Azzini Elena , Vitaglione Paola , Intorre Federica , Napolitano Aurora , Durazzo Alessandra , Foddai Maria S. , Fumagalli Alessandro , Catasta Giovina , Rossi Laura , Venneria Eugenia , Raguzzini Anna , Palomba Lara , Fogliano Vincenzo , Maiani Giuseppe
Published: May 2010

Strawberries contain many antioxidant phytochemicals such as vitamin C, carotenoids and phenolic compounds including anthocyanins (ACN). In the present study, antioxidant composition of fresh strawberries (FS) and stored strawberries (SS) and the bioavailability of the main strawberry bioactive compounds were determined in human subjects. Thirteen healthy volunteers consumed 300 g of FS and SS on two separate occasions. Blood, before and at different time points from meal consumption, as well as 24 h urine, was collected, and parent compounds and metabolites of the different compounds were determined by HPLC or LC/MS/MS. A reduction in α-carotene plasma concentrationsv.baseline values was recorded after the consumption of FS, although the amount of this carotenoid was higher in the SS. On the contrary, a significant increase of plasma vitamin C after 2, 3 and 5 h (P < 0·05) of FS and SS consumption was recorded. No quercetin and ACN were found in plasma, while coumaric acid, 4-hydroxybenzoic acid (4HBA, 56 and 54 % of pelargonidin-3-glucoside (Pel-glc) ingested with FS and SS, respectively) and protocatechuic acid (59 and 34 % of cyanidin-3-glucoside ingested with FS and SS, respectively) over 8 h from strawberry consumption were retrieved in the plasma. Pelargonidin glucuronide, pelargonidin glucoside and pelargonidin aglycone peaked in urine within 2 h of strawberry consumption, and the 24 h amount excreted was always approximately 0·9 % of the Pel-glc dose ingested. The data indicated that the content of phytochemicals in strawberries may influence the bioavailability of individual compounds. Furthermore, in the present study, the metabolism of Pel-glc was elucidated, and, for the first time, 4HBA was suggested to be a major human metabolite of Pel-glc.
Direct verification of the lubrication force on a sphere travelling through a viscous film upon approach to a solid wall
Authors: MARSTON J. O. , YONG W. , THORODDSEN S. T.
Published: May 2010

Experiments were performed to observe the motion of a solid sphere approaching a solid wall through a thin layer of a viscous liquid. We focus mainly on cases where the ratio of the film thickness, δ, to the sphere diameter, D, is in the range 0.03 < δ/D < 0.09 and the Stokes number, St, a measure of the sphere inertia to viscous forces, is below a critical level Stc so that the spheres do not rebound and escape from the liquid layer. This provides us with the scope to verify the force acting on the sphere, derived from lubrication theory. Using high-speed video imaging we show, for the first time, that the equations of motion based on the lubrication approximation correctly describe the deceleration of the sphere when St < Stc. Furthermore, we show that the penetration depth at which the sphere motion is first arrested by the viscous force, which decreases with increasing Stokes number, matches well with theoretical predictions. An example for a shear-thinning liquid is also presented, showing that this simple set-up may be used to deduce the short-time dynamical behaviour of non-Newtonian liquids.
Refining strategic culture: return of the second generation
Authors: LOCK EDWARD
Published: May 2010

This article seeks to refine the concept of ‘strategic culture’ and to highlight some appropriate methods of analysis through which this concept might be applied in empirical studies. In doing so, I seek to synthesise a much ignored element of strategic culture literature – Bradley Klein's ‘second generation’ approach – with insights drawn from contemporary critical constructivist theory. The resulting conception of strategic culture presents a less deterministic account of culture than that found in much existing literature regarding. It also provides far greater critical potential with regard to the analysis of the strategic practices of states and other actors. More generally, this conception of strategic culture leads us to ask how strategic culture serves to constitute certain strategic behaviour as meaningful but also how strategic behaviour serves to constitute the identity of those actors that engage in such behaviour.
Performing Schengen: myths, rituals and the making of European territoriality beyond Europe
Authors: ZAIOTTI RUBEN
Published: May 2010

Myth-making has historically been an essential component of the modern state's quest for territorial control and legitimacy. As a sui generis post-national political entity in search for identity and recognition, the European Union (EU) seems to mimicking its more established national counterpart. By formulating and reproducing a narrative that hails Europe's border control regime (‘Schengen’) as a success story of European integration and by deploying evocative imagery at Europe's common borders, the EU is in fact trying to establish itself as an integral part of the European political landscape. This article argues that what we are witnessing today in Europe is indeed the emergence of the ‘myth of Schengen’; however, the regime's mythopoiesis goes beyond the EU's official narrative and symbolic representations. To capture the full range of actors, locations and activities involved in the establishment and reproduction of this post-national myth, it is necessary to shift the attention to the performative dimension of this process. To support this argument, the article relies on the insights of anthropological and sociological works that have emphasised the role of rituality and performativity in constituting social structures and identities. These insights are then applied to examine the rituals and performances characterising four cases of ‘unofficial’ Schengen myth-making beyond Europe: a hotel in Beijing, street kids in Kinshasa, a British music band, and a group of Eastern European artists.
On some rigidity results of hypersurfaces in a sphere
Authors: Cheng Qing-Ming , Li Haizhong , Wei Guoxin
Published: May 2010

We study the weak stability index of an immersion ϕ: M → Sn+1 (1) ⊂ Rn+2 of an n-dimensional compact Riemannian manifold. We prove that the weak stability index of a compact hypersurface M with constant scalar curvature in Sn+1 (1), which is not totally umbilical, is greater than or equal to n + 2 if the mean curvature H1 and H3 are constant, and that the equality holds if and only if M is $\smash{S^m(c)\times S^{n-m}(\sqrt{1-c^2})}$. As an application, we show that the weak stability index of an n-dimensional compact hypersurface with constant scalar curvature in Sn+1 (1), which is neither totally umbilical nor a Clifford hypersurface, is greater than or equal to 2n + 4 if the mean curvature H1 and H3 are constant.
Quasi-completely continuous multilinear operators
Authors: Peralta Antonio M. , Villanueva Ignacio , Wright J. D. Maitland , Ylinen Kari
Published: May 2010

We introduce the concept of quasi-completely continuous multilinear operators and use this concept to characterize, for a wide class of Banach spaces X1, …, Xk, the multilinear operators T : X1 × … × Xk → X with an X-valued Aron–Berner extension.
Homogenization of a class of quasilinear elliptic equations with non-standard growth in high-contrast media
Authors: Choquet C. , Pankratov L.
Published: May 2010

We study the asymptotic behaviour of solutions to a quasilinear equation with high-contrast coefficients. The energy formulation of the problem leads to work with variable exponent Lebesgue spaces Lpε (·) in a domain Ω with a complex microstructure depending on a small parameter ε. Assuming only that the functions pε converge uniformly to a limit function p0 and that p0 satisfy certain logarithmic uniform continuity conditions, we rigorously derive the corresponding homogenized problem which is completely described in terms of local energy characteristics of the original domain. In the framework of our method we do not have to specify the geometrical structure Ω. We illustrate our result with periodical examples, extending, in particular, the classical extension results to variable exponent Sobolev spaces.
Comparison of four reliability surrogate measures for water distribution systems design
Authors: Raad D. N. , Sinske A. N. , van Vuuren J. H.
Published: May 2010

Water distribution system (WDS) design naturally involves a trade‐off between the cost and reliability or robustness of a design. Traditionally, WDS reliability quantification schemes have employed graph theoretic techniques or probabilistic schemes such as Monte Carlo simulation. In recent decades there has been increased interest in the application of so‐called reliability surrogate measures, such as flow entropy, the resilience index, and network resilience, because of their ease of use and dramatically reduced computational burden. In this paper, these surrogate measures (as well as a mixed reliability surrogate) are employed in the multiobjective evolutionary design of a set of WDS benchmarks from the literature. The resulting Pareto‐optimal sets in cost‐reliability space for each surrogate measure are analyzed in terms of their ability to handle demand uncertainty and pipe failure, and a regression analysis is conducted in order to determine whether the surrogate measures are correlated to stochastic reliability and failure reliability as expressed by demand satisfaction measures. It is found that the resilience index demonstrates the best performance under pure stochastic demand variation. However, it lags when compared to the network resilience and mixed reliability measures in terms of reliability under pipe failure conditions. These are recommended as the most practical reliability surrogate measures for use in general WDS design, since they also produce designs that minimize size discontinuities between adjacent pipes. Flow entropy performs relatively poorly in terms of correlation to both stochastic reliability and failure reliability.
Energy transfer mechanisms in Yb3+ doped YVO4 near-infrared downconversion phosphor
Authors: Wei XianTao , Huang Shan , Chen YongHu , Guo ChangXin , Yin Min , Xu Wu
Published: May 2010

Upon ultraviolet (UV) light excitation, an intense near-infrared (NIR) emission of Yb3+ (F25/2→F27/2) around 980 nm is observed in YVO4:Yb3+ phosphors. Owing to host absorption of YVO4, a broad excitation band ranging from 250 to 350 nm is recorded when the Yb3+ emission was monitored, which suggests an efficient energy transfer from host to Yb3+ ions. The Yb3+ concentration dependence of the visible vanadate emission as well as the Yb3+ emission is investigated. The decay curve of vanadate emission is measured under the excitation of a 266 nm pulsed laser. The decay time of the vanadate emission at 500 nm is remarkably reduced by introducing Yb3+ ions, further verifying that the energy transfer from the vanadate host to the Yb3+ ions is very efficient. Cooperative energy transfer (CET) is discussed as a possible mechanism for the NIR emission. The YVO4:Yb3+ phosphor can convert each UV photon into two NIR photons via CET, which has potential application in the high efficiency silicon-based solar cells.
Theory of the optical spatial separation of racemic mixtures of chiral molecules
Authors: Li Xuan , Shapiro Moshe
Published: May 2010

We propose a practical way of spatially separating a (“racemic”) mixture of left-handed (L) and right-handed (R) chiral molecules using optically induced forces. The enantioselectivity of the method emanates from the sign difference between the n↔m electric-dipole matrix elements of enantiomers of opposite handedness, and the, uniquely chiral, “cyclic adiabatic passage” laser configuration. The combination of these two factors is shown to cause considerable differences in the magnitude and direction of the optically induced forces as felt by enantiomers of opposite handedness. Two arrangements, tested by performing quantum wave packet propagation and classical trajectories, are suggested. Both arrangements involve the intracavity interaction of the racemic mixture with three, partially overlapping, cw laser beams. The first arrangement is composed of trapped molecules at 1 mK interacting with standing wave lasers. The second configuration uses a tightly skimmed molecular beam of a racemic mixture, forming one arm of a four-sided cavity, intersecting at a small angle the three laser beams.
Plasmonic mid-infrared beam steering
Authors: Adams D. C. , Thongrattanasiri S. , Ribaudo T. , Podolskiy V. A. , Wasserman D.
Published: May 2010

We present a metal/semiconductor beam steering device for use in the mid-infrared wavelength range. We demonstrate how changing the frequency of the incident light results in a smoothly varying shift in the angular distribution of the transmitted beam, and we present an analysis of the beam profile for a number of different wavelengths. Finally we verify that a similar steering effect is achieved with fixed frequency incident light and a modification of the permittivity of the semiconductor substrate, ultimately resulting in a 3° shift in the transmitted beam angle for minimal shifts in the semiconductor permittivity.
Vibrational Förster transfer to hydrated protons
Authors: Timmer R. L. A. , Tielrooij K. J. , Bakker H. J.
Published: May 2010

We have studied the influence of excess protons on the vibrational energy relaxation of the O–H and O–D stretching modes in water using femtosecond pump-probe spectroscopy. Without excess protons, we observe exponential decays with time constants of 1.7 and 4.3 ps for the bulk and anion bound O–D stretch vibrations. The addition of protons introduces a new energy relaxation pathway, which leads to an increasingly nonexponential decay of the O–D stretch vibration. This new pathway is attributed to a distance-dependent long range dipole-dipole (Förster) interaction between the O–D stretching vibration and modes associated with dissolved protons. The high efficiency of hydrated protons as receptors of vibrational energy follows from the very large absorption cross section and broad bandwidth of protons in water. For a proton concentration of 1M we find that Förster energy transfer occurs over an average distance of 4.5 Å, which corresponds to a separation of about two water molecules.
Mechanism of surface leakage of nanoscale Schottky contacts between ErSi2 nanoislands and Si(001)
Authors: Song J. Q. , Ding T. , Cai Q.
Published: May 2010

The surface leakage mechanism of nanoscale Schottky contacts between epitaxially grown ErSi2 nanoislands and p-Si(100) is investigated by using controlled surface adsorption of O2 and NH3. The surface leakage conduction is found to play a dominant role in the electrical transport of the nanocontacts. Interestingly, the surface leakage current increases linearly with reverse bias but it increases exponentially with forward bias. This behavior can be explained using surface-state conduction with reverse bias and low surface barrier region with forward bias.
Synthesis of N-Propargyl Iminosugar Scaffolds for Compound Library Generation using Click Chemistry
Authors: Wilkinson Brendan L. , Bornaghi Laurent F. , Lopez Marie , Healy Peter C. , Poulsen Sally-Ann , Houston Todd A.
Published: May 2010

We have developed an efficient synthesis of N-propargyl iminosugars for use in diversity-oriented library development. Through a common, crystalline intermediate both piperidine and azepane scaffolds can be prepared with an alkyne functional group, allowing for further elaboration through reaction with azides.
Carbon-Supported Nickel Nanoparticles from a Wood Sample of the Tree Sebertia acuminata Pierre ex. Baillon
Authors: Lerch Martin , Ressler Thorsten , Krumeich Frank , Cosson Jean-Pierre , Hnawia Edouard , Grohmann Andreas
Published: May 2010

A wood sample of the nickel hyperaccumulator tree Sebertia acuminata Pierre ex. Baillon was pyrolyzed in an inert atmosphere to produce a charcoal-like material containing nanoparticulate nickel. Its overall nickel content was determined to be ~7 wt-% by wet chemical analysis (acid digestion, inductively coupled plasma optical emission spectroscopy). Depending on the conditions of pyrolysis (5 h at 800°C; or 5 h at 800°C followed by 7 h at 900°C), the average crystallite sizes were ~7 and 42 nm, respectively, as determined by X-ray powder diffraction (XRD) and electron microscopy (scanning, scanning transmission, and transmission). Furthermore, high resolution transmission electron microscopy images reveal that the Ni particles are, in some cases, encapsulated with graphitic carbon layers of varying thickness. Scanning electron microscopy results indicate for the most part, a preservation of the wood framework and a remarkably uniform distribution of the nickel nanoparticles in the vessels of the xylem. XRD and X-ray absorption fine structure analysis reveal the presence of NiO besides Ni.
Structure and Activity of the Leaf-Specific Cyclotide vhl-2
Authors: Daly Norelle L. , Chen Bin , Nguyencong Philip , Craik David J.
Published: May 2010

Cyclotides are plant-derived macrocyclic peptides with potential applications in the pharmaceutical and agricultural industries. In addition to their presumed natural function as host-defence peptides arising from their insecticidal activity, their other biological activities include antimicrobial, haemolytic, and cytotoxic activities, but at present, only limited information is available on the structural and chemical features that are important for these various activities. In the current study, we determined the three-dimensional structure of vhl-2, a leaf-specific cyclotide. Although the characteristic cyclic cystine knot fold of other cyclotides is maintained in vhl-2, it has more potent haemolytic activity than well-characterized cyclotides such as kalata B1 and kalata B8. Analysis of surface hydrophobicity and haemolytic activity for a range of cyclotides indicates a correlation between them, with increasing hydrophobicity resulting in increased haemolytic activity. This correlation is consistent with membrane binding being a vital step in mediating the various cytotoxic activities of cyclotides. The gene sequence for vhl-2 was determined and indicates that vhl-2 is processed from a multidomain precursor protein that also encodes the cyclotide cycloviolacin H3.
Microencapsulated Palladium Catalysts: Pd EnCatTM
Authors: Barros José C.
Published: May 2010

In this manuscript some applications of microencapsulated palladium catalysts – Pd EnCatTM – are reviewed. These new catalysts are highly active, stable, easy recoverable, and could be employed in C–C coupling, hydrogenation, ring opening of epoxides between others.
Acid-Catalyzed Reactions of 3-Substituted-4,6-dimethoxyindoles with Ketones
Authors: Wood Kasey , Black David StC. , Kumar Naresh
Published: May 2010

Activated 3-substituted-4,6-dimethoxyindoles undergo acid catalyzed condensation with acetone and acetophenones in the presence of hydrochloric acid to give pyrrolo[a]indoles. Mixed pyrrolo[a]indoles can similarly be formed using a 1:1 mixture of two indoles. The reaction was found to be sensitive to acidity, with a 3:2 spiro condensation product being preferentially formed in the presence of p-toluenesulfonic acid.
Highlights of the 2009 New South Wales Southern Highlands Conference on Heterocyclic Chemistry
Authors: Read Roger W.
Published: May 2010

Meetings that foster interaction between academic and industrial researchers, both operating at the forefront of science, serve to stimulate ideas and allow partnerships to develop. The Southern Highlands Conference brings together experts in the field of heterocyclic chemistry and, in this issue, some of the most recent advances are highlighted (The figure shows 2009 Conference student speakers with President Barbara Messerle).
Can Mechanisms Really Replace Laws of Nature?
Authors: Leuridan Bert
Published: May 2010

Today, mechanisms and mechanistic explanation are very popular in philosophy of science and are deemed a welcome alternative to laws of nature and deductive-nomological explanation. Starting from Mitchell's pragmatic notion of laws, I cast doubt on their status as a genuine alternative. I argue that (1) all complex-systems mechanisms ontologically must rely on stable regularities, while (2) the reverse need not hold. Analogously, (3) models of mechanisms must incorporate pragmatic laws, while (4) such laws themselves need not always refer to underlying mechanisms. Finally, I show that Mitchell's account is more encompassing than the mechanistic account.
Carnap, the Principle of Tolerance, and Empiricism
Authors: Hudson Robert
Published: May 2010

Kurt Gödel criticizes Rudolf Carnap's conventionalism on the grounds that it relies on an empiricist admissibility condition, which, if applied, runs afoul of his second incompleteness theorem. Thomas Ricketts and Michael Friedman respond to Gödel's critique by denying that Carnap is committed to Gödel's admissibility criterion; in effect, they are denying that Carnap is committed to any empirical constraint in the application of his principle of tolerance. I argue in response that Carnap is indeed committed to an empirical requirement vis-à-vis tolerance, a fact that becomes clear upon closer scrutiny of Carnap's relevant writings.
Quorum sensing in bacterial virulence
Authors: Antunes L. Caetano M. , Ferreira Rosana B. R. , Buckner Michelle M. C. , Finlay B. Brett
Published: May 2010

Bacteria communicate through the production of diffusible signal molecules termed autoinducers. The molecules are produced at basal levels and accumulate during growth. Once a critical concentration has been reached, autoinducers can activate or repress a number of target genes. Because the control of gene expression by autoinducers is cell-density-dependent, this phenomenon has been called quorum sensing. Quorum sensing controls virulence gene expression in numerous micro-organisms. In some cases, this phenomenon has proven relevant for bacterial virulencein vivo. In this article, we provide a few examples to illustrate how quorum sensing can act to control bacterial virulence in a multitude of ways. Several classes of autoinducers have been described to date and we present examples of how each of the major types of autoinducer can be involved in bacterial virulence. As quorum sensing controls virulence, it has been considered an attractive target for the development of new therapeutic strategies. We discuss some of the new strategies to combat bacterial virulence based on the inhibition of bacterial quorum sensing systems.
VASCULAR-RELATED NAC-DOMAIN6 and VASCULAR-RELATED NAC-DOMAIN7 Effectively Induce Transdifferentiation into Xylem Vessel Elements under Control of an Induction System
Authors: Yamaguchi Masatoshi , Goué Nadia , Igarashi Hisako , Ohtani Misato , Nakano Yoshimi , Mortimer Jennifer C. , Nishikubo Nobuyuki , Kubo Minoru , Katayama Yoshihiro , Kakegawa Koichi , Dupree Paul , Demura Taku
Published: May 2010

We previously showed that the VASCULAR-RELATED NAC-DOMAIN6 (VND6) and VND7 genes, which encode NAM/ATAF/CUC domain protein transcription factors, act as key regulators of xylem vessel differentiation. Here, we report a glucocorticoid-mediated posttranslational induction system of VND6 and VND7. In this system, VND6 or VND7 is expressed as a fused protein with the activation domain of the herpes virus VP16 protein and hormone-binding domain of the animal glucocorticoid receptor, and the protein's activity is induced by treatment with dexamethasone (DEX), a glucocorticoid derivative. Upon DEX treatment, transgenic Arabidopsis (Arabidopsis thaliana) plants carrying the chimeric gene exhibited transdifferentiation of various types of cells into xylem vessel elements, and the plants died. Many genes involved in xylem vessel differentiation, such as secondary wall biosynthesis and programmed cell death, were up-regulated in these plants after DEX treatment. Chemical analysis showed that xylan, a major hemicellulose component of the dicot secondary cell wall, was increased in the transgenic plants after DEX treatment. This induction system worked in poplar (Populus tremula × tremuloides) trees and in suspension cultures of cells from Arabidopsis and tobacco (Nicotiana tabacum); more than 90% of the tobacco BY-2 cells expressing VND7-VP16-GR transdifferentiated into xylem vessel elements after DEX treatment. These data demonstrate that the induction systems controlling VND6 and VND7 activities can be used as powerful tools for understanding xylem cell differentiation.
The dual-space resolution bias correction algorithm: applications to powder data
Authors: Altomare Angela , Cuocci Corrado , Giacovazzo Carmelo , Moliterni Anna , Rizzi Rosanna
Published: May 2010

A reciprocal-space resolution bias correction algorithm has been recently suggested, providing suitable corrections for the classical atomic scattering factors. The Fourier maps calculated by using as coefficients the structure factors obtained by the modified scattering factors proved to be less resolution biased. In this paper the correction has been generalized in order to apply it to the experimental structure factor moduli; in this way more useful electron density maps may be calculated. In a less recent paper a direct-space resolution bias correction algorithm was devised and tested on a large set of powder patterns; the algorithm implies the modification of the electron density maps to reduce the truncation errors in the Fourier syntheses. In the present paper direct and reciprocal resolution bias correction algorithms are combined into the dual-space resolution bias correction algorithm. The usefulness of the new algorithm is checked on a set of powder patterns.
A single centre experience in circumcision of haemophilia patients: Izmir protocol
Authors: YILMAZ D. , AKIN M. , AY Y. , BALKAN C. , ÇELIK A. , ERGÜN O. , KAVAKLI K.
Published: May 2010

Summary.  Haemophiliacs and their families consider that circumcision is a very important step to become a member of society and it is a social obligation for men in Turkey. Although bleeding risk is high, almost all haemophiliacs would like to be circumcised in Turkish society. The aim of this study was to evaluate our experience in circumcision of haemophilia patients and define efficacy, safety and complication rates of our protocol, called ‘Izmir protocol’. In this study, we retrospectively reviewed medical records of 50 patients with haemophilia who underwent circumcision at our hospital according to Izmir protocol between 1996 and 2009. Oral tranexamic acid and fibrin glue were used in all children. One hour before the operation, first dose of factor concentrate was given. After reaching a plasma factor level of around 90–100%, the prepuce was incised circumferentially and excised using Gomco clamp or open technique under general anaesthesia. Intermittent injections of factor concentrate were given every 12 for 48 h. While the first two doses were given at higher amount to achieve or continue plasma factor level at 90–100%, in the last three doses, the aim was to maintain the plasma factor level at 50–60%. Forty‐eight hours after the circumcision, patients were discharged. Three patients (6%) showed bleeding complication and all were resolved easily. All had at least one excuse from the protocol (Lower doses of factor concentrates was used in 2, tranexamic acid was not used in 2). Izmir protocol is safe, cheap and easy to carry out.
A predictive model for detection ofAgrilus planipennis(Col., Buprestidae) larvae in girdled ash (Fraxinusspp.)
Authors: Marshall J. M. , Storer A. J. , Fraser I. , Mastro V. C.
Published: May 2010

Agrilus planipennis(emerald ash borer, Coleoptera: Buprestidae) is a pest of ash (Fraxinusspp.) in North America and has caused mortality of ash throughout its introduced range. One technique used for detection ofA. planipennisis the establishment and peeling of girdled trap trees. In an effort to reduce the search effort and target detection survey efforts within ash trap trees, a predictive model was created using data from 2007 and validated using data from 2008. In 2007 and 2008, ash trap trees were established, harvested, peeled and inspected forA. planipennislarvae. Gaussian curves were fit to describe the relationship between stem diameter and relative proportion and frequency of larvae. The observed and predicted 2008 relative proportion and frequency of larvae did not differ in paired t‐tests. Within the relative proportion and frequency Gaussian models, the curves peaked at approximately 10 cm diameter signifying the greatest proportion and frequency ofA. planipennislarvae occurred at 10 cm stem diameter. This peak was then bracketed by 2 cm on each side creating a target stem section with a top diameter of 8 cm and a bottom diameter of 12 cm. A simple linear regression was fit to describe the relationship between the larvae count within the targeted 8–12 cm section of tree and the larvae per cm3of phloem per tree for 2007. The observed and predicted 2008 larvae per cm3did not differ in a paired t‐test. Targeting the 8–12 cm diameter section of the trap tree stem will reduce the amount of the tree peeled to less than 45% with more than 50% ofA. planipennislarvae within the tree encountered in this targeted section. This reduction in the amount of tree peeled will greatly increase the number of trees and area surveyed forA. planipennisdetection and population delimiting surveys.
The effects of multiple overloads and absorbed hydrogen on the fatigue strength of notched steel specimens
Authors: KONDO Y. , YAMANOUCHI T.
Published: May 2010

It is well known that earthquakes can damage structures and machinery. After an earthquake, those components, which have been obviously damaged are scrapped and replaced, and most of the components which have not been obviously damaged will continue to be used even after earthquakes. However, as will be shown, the earthquake may have severely impaired the fatigue strength of such components by introducing unfavourable residual stresses and short cracks at stress raisers. In addition, if such components should contain hydrogen, an increasingly possible scenario for the hydrogen economy in the future, then it is shown that the loss of fatigue strength can be even greater. This paper explores the extent of fatigue degradation due to overloads and to absorbed hydrogen. It was shown that generation of small crack and tensile residual stress imposed by overloads caused substantial decrease of residual fatigue strength compared with that in the initial state. It was also shown that hydrogen enhanced more reduction. Hydrogen enhanced reduction in two ways. The crack generated by overloads grew deeper in hydrogen charged material. In addition to this, the reduction of ΔKth also occurred in hydrogen charged material. These two factors worked together to reduce the residual fatigue strength after multiple overloads.
Biogeochemical controls on microbial diversity in seafloor sulphidic sediments
Authors: MÜLLER M. , HANDLEY K. M. , LLOYD J. , PANCOST R. D. , MILLS R. A.
Published: May 2010

The ultimate fate of hydrothermal sulphides on the seafloor depends on the nature and rate of abiotic and microbially catalysed reactions where sulphide minerals are exposed to oxic seawater. This study combines organic and inorganic geochemical with microbiological measurements across a suboxic transition zone of highly altered sulphidic sediments from the Trans‐Atlantic Geotransverse hydrothermal field to characterize the reaction products and microbial communities present. There is distinct biogeochemical zonation apparent within the sediment sequence from oxic surface layers through a suboxic transition zone into the sulphide material. The microbial communities in the sediment differ significantly between the biogeochemical horizons sampled, with the identified microbes inferred to be associated with Fe and S redox cycling. In particular, Marinobacter species, organisms associated with circumneutral Fe oxidation, are dominant in a sulphide lens present in the lower core. The dominance of Marinobacter‐related sequences within the relict sulphide lens implies that these organisms play an important role in the alteration of sulphides at the seafloor once active venting has ceased.