bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization and costs of conventional and alternative pharmaceuticals in children: results from the German GINIplus and LISAplus birth cohort studies
Authors: Italia Salvatore , Batscheider Ariane , Heinrich Joachim , Wenig Christina , Bauer Carl Peter , Koletzko Sibylle , Lehmann Irina , Herbarth Olf , von Berg Andrea , Berdel Dietrich , Hoffmann Barbara , Schaaf Beate , Wolfenstetter Silke B.
Published: August 2012

Purpose

The socioeconomic determinants for drug utilization, especially in children, have not been investigated sufficiently so far. The study's aim was the estimation of prevalences and determinants of conventional, homeopathic and phytotherapeutic drugs and expenditures.

Methods

Population‐based data on drug utilization of 3,642 children in two German birth cohorts (GINIplus and LISAplus, 10‐year follow‐up) were collected using a self‐administered questionnaire. For analysis, the reported drugs (use within the last four weeks) were classified into the therapeutic categories of ‘conventional medicine’, ‘homeopathy’, ‘phytotherapy’ and ‘others’. Drug costs were estimated using pharmaceutical identification numbers.

Results

In all, 42.3% of the children reported drug use; 24.1% of the drugs were homeopathic and 11.5% were phytotherapeutic. The proportion of children who took at least one homeopathic remedy was 14.3%. Drugs prescribed by physicians were dominated by conventional medicine (76.5%), whereas in non‐prescribed drugs, both homeopathy and conventional medicine accounted for 37% each. Boys (OR = 0.78) used less homeopathy than girls. Income showed only a weak influence. Education had a strong effect on the use of phytotherapy such that children of mothers with higher school education (>10 years vs. <10 years) used more phytotherapy (OR = 2.01). If out‐of‐pocket payments arose (n = 613), the mean was €20. On average, total drug expenditures summed up to €39 in 4 weeks for drug users if only clearly identifiable prices for drugs were considered (58% of all data).

Conclusions

Utilization of homeopathy is common in children from the analyzed cohort. User profiles of homeopathy and phytotherapy differ from each other and should be analyzed separately. Copyright © 2012 John Wiley & Sons, Ltd.
Exploration of the active site of Escherichia coli cystathionine γ‐synthase
Authors: Jaworski Allison F. , Lodha Pratik H. , Manders Adrienne L. , Aitken Susan M.
Published: August 2012

Cystathionine γ‐synthase (CGS) catalyzes the condensation of O‐succinyl‐L‐homoserine (L‐OSHS) and L‐cysteine (L‐Cys), to produce L‐cystathionine (L‐Cth) and succinate, in the first step of the bacterial transsulfuration pathway. In the absence of L‐Cys, the enzyme catalyzes the futile α,γ‐elimination of L‐OSHS, yielding succinate, α‐ketobutyrate, and ammonia. A series of 16 site‐directed variants of Escherichia coli CGS (eCGS) was constructed to probe the roles of active‐site residues D45, Y46, R48, R49, Y101, R106, N227, E325, S326, and R361. The effects of these substitutions on the catalytic efficiency of the α,γ‐elimination reaction range from a reduction of only ∼2‐fold for R49K and the E325A,Q variants to 310‐ and 760‐fold for R361K and R48K, respectively. A similar trend is observed for the kcat/K of the physiological, α,γ‐replacement reaction. The results of this study suggest that the arginine residues at positions 48, 106 and 361 of eCGS, conserved in bacterial CGS sequences, tether the distal and α‐carboxylate moieties, respectively, of the L‐OSHS substrate. In contrast, with the exception of the 13‐fold increase observed for R106A, the K is not markedly affected by the site‐directed replacement of the residues investigated. The decrease in kcat observed for the S326A variant reflects the role of this residue in tethering the side chain of K198, the catalytic base. Although no structures exist of eCGS bound to active‐site ligands, the roles of individual residues is consistent with the structures inhibitor complexes of related enzymes. Substitution of D45, E325, or Y101 enables a minor transamination activity for the substrate L‐Ala.
The University of Pennsylvania MAGIC 2010 multi‐robot unmanned vehicle system
Authors: Butzke J. , Daniilidis K. , Kushleyev A. , Lee D. D. , Likhachev M. , Phillips C. , Phillips M.
Published: August 2012

In this report, we describe the technical approach and algorithms that have been used by the University of Pennsylvania in the MAGIC 2010 competition. We have constructed and deployed a multi‐vehicle robot team, consisting of intelligent sensor and disrupter unmanned ground vehicles that can survey, map, recognize, and respond to threats in a dynamic urban environment with minimal human guidance. The custom hardware systems consist of robust and complementary sensors, integrated electronics, computation, and highly capable propulsion and actuation. The mapping, navigation, and planning software is organized hierarchically, allowing autonomous decisions to be made by the robots while enabling human operators to interact with the robot team in an efficient and strategic manner. The ground control station integrates information coming from the robots as well as metadata feeds to focus the attention of the operators and respond rapidly to emerging threats. These systems were developed and tested by the UPenn team to complete two phases of the MAGIC 2010 challenge in a safe and timely manner. © 2012 Wiley Periodicals, Inc.
Degradation of deep ultraviolet photoresist by As‐implantation studied by Ar‐cluster beam profiling
Authors: Conard T. , Franquet A. , Tsvetanova D. , Mouhib T. , Vandervorst W.
Published: August 2012

Wet processes are gaining a renewed interest for removal of high‐dose ion‐implanted photoresist (II‐PR) in front‐end‐of‐line semiconductor manufacturing because of their excellent selectivity towards the wafer substrate and gate materials. The selection of wet chemistries is supported by an insight into the resist degradation by ion implantation. TOF‐SIMS has been applied for characterization of the chemical changes in 248 nm deep UV photoresist after arsenic implantation. The cross‐linking of the resist is dominant, especially for high doses and energies. It leads to significant depletion of hydrogen and formation of carbon macroradicals that recombine to form C‐C cross‐linked crust. A series of implanted samples were depth profiled using O2, Cs, C60 and an Ar‐cluster beam as sputter species in order to analyze the chemical modifications inside the crust layer. Whereas in the implanted region, no sputter conditions providing molecular information have yet been identified, in the non‐implanted region, many molecular ions are identified when profiling using Ar‐clusters as sputter ions. Neither O2, Cs nor C60 sputtering would lead to molecular information in this region either. In particular with Ar‐clusters, very large differences in sputter rates have also been observed between the implanted and non‐implanted region, as well as a significant matrix effect in the implanted region. These differences are linked to the level of cross‐linking present in the crust layer. Copyright © 2012 John Wiley & Sons, Ltd.
Oxygen transport in electroceramics investigated by electrochemical 18O/16O isotope exchange and ToF‐SIMS
Authors: Langer‐Hansel K. , Schintlmeister A. , Fleig J. , Hutter H.
Published: August 2012

In this contribution 18O tracer diffusion experiments were carried out on electroceramics and analysed by time‐of‐flight secondary‐ion mass spectrometry. For the analysis, different operation modes of the Bi liquid metal ion gun were compared with respect to signal intensity, lateral resolution and mass resolution. Procedures for obtaining a basic estimation of the 18O fraction are given. It is shown that high target current, i.e. high number of primary ions, increases the accuracy and the precision of the determination of the 18O fraction if the observed count rate of the 16O signal is lower than 0.95 cts/shot. As an example, 18O diffusion profiles at the surface of a ZrO2:9.5mol%Y2O3 single crystals are shown. Copyright © 2012 John Wiley & Sons, Ltd.
Supersymmetry breaking induced by radiative corrections
Authors: Bajc Borut , Lavignac Stéphane , Mede Timon
Published: August 2012

Abstract

We show that simultaneous gauge and supersymmetry breaking can be induced by radiative corrections, à la Coleman-Weinberg. When a certain correlation among the superpotential parameters is present, a local supersymmetry-breaking minimum is induced in the effective potential of a gauge non-singlet field, in a region where the tree-level potential is almost flat. Supersymmetry breaking is then transmitted to the MSSM through gauge and chiral messenger loops, thus avoiding the suppression of gaugino masses characteristic of direct gauge mediation models. The use of a single field ensures that no dangerous tachyonic scalar masses are generated at the one-loop level. We illustrate this mechanism with an explicit example based on an SU(5) model with a single adjoint. An interesting feature of the scenario is that the GUT scale is increased with respect to standard unification, thus allowing for a larger colour Higgs triplet mass, as preferred by the experimental lower bound on the proton lifetime.
Bianchi attractors: a classification of extremal black brane geometries
Authors: Iizuka Norihiro , Kachru Shamit , Kundu Nilay , Narayan Prithvi , Sircar Nilanjan , Trivedi Sandip P.
Published: August 2012

Abstract

Extremal black branes are of interest because they correspond to the ground states of field theories at finite charge density in gauge/gravity duality. The geometry of such a brane need not be translationally invariant in the spatial directions along which it extends. A less restrictive requirement is that of homogeneity, which still allows points along the spatial directions to be related to each other by symmetries. In this paper, we find large new classes of homogeneous but anisotropic extremal black brane horizons, which could naturally arise in gauge/gravity dual pairs. In 4+1 dimensional spacetime, we show that such homogeneous black brane solutions are classified by the Bianchi classification, which is well known in the study of cosmology, and fall into nine classes. In a system of Einstein gravity with negative cosmological term coupled to one or two massive Abelian gauge fields, we find solutions with an additional scaling symmetry, which could correspond to the near-horizon geometries of such extremal black branes. These solutions realize many of the Bianchi classes. In one case, we construct the complete extremal solution which asymptotes to AdS space.
Reach the bottom line of the sbottom search
Authors: Álvarez Ezequiel , Bai Yang
Published: August 2012

Abstract

We propose a new search strategy for directly-produced sbottoms at the LHC with a small mass splitting between the sbottom and its decayed stable neutralino. Our search strategy is based on boosting sbottoms through an energetic initial state radiation jet. In the final state, we require a large missing transverse energy and one or two b-jets besides the initial state radiation jet. We also define a few kinematic variables to further increase the discovery reach. For the case that the sbottom mainly decays into the bottom quark and the stable neutralino, we have found that even for a mass splitting as small as 10 GeV sbottoms with masses up to around 400 GeV can be excluded at the 95 % confidence level with 20 inverse femtobarn data at the 8 TeV LHC.
Green bundles, Lyapunov exponents and regularity along the supports of the minimizing measures
Authors: Arnaud M.-C.
Published: August 2012

In this article, we study the minimizing measures of the Tonelli Hamiltonians. More precisely, we study the relationships between the so-called Green bundles and various notions as:

In particular, we deduce that the support of every minimizing measure

μ

, all of whose Lyapunov exponents are zero, is

C^{1}

-regular

μ

-almost everywhere.

Dans cet article, on étudie les mesures minimisantes de Hamiltoniens de Tonelli. Plus précisément, on explique quelles relations existent entre les fibrés de Green et différentes notions comme :

On en déduit par exemple que si tous les exposants de Lyapunov dʼune mesure minimisante

μ

sont nuls, alors le support de cette mesure est

C^{1}

-régulier en

μ

-presque tout point.
Pulsating fronts for nonlocal dispersion and KPP nonlinearity
Authors: Dávila Juan , Martínez Salomé , Coville Jérôme
Published: August 2012

In this paper we are interested in propagation phenomena for nonlocal reaction–diffusion equations of the type:

\frac{\partial u}{\partial t} = J\ast u−u + f(x,u)\:t \in \mathbb{R},\:x \in \mathbb{R}^{N},

where

J

is a probability density and

f

is a KPP nonlinearity periodic in the

x

variables. Under suitable assumptions we establish the existence of pulsating fronts describing the invasion of the

0

state by a heterogeneous state. We also give a variational characterization of the minimal speed of such pulsating fronts and exponential bounds on the asymptotic behavior of the solution.
Occupational risks of esophageal cancer in Taiwanese men
Authors: Huang Shih‐Hui , Wu I‐Chen , Wu Deng‐Chyang , Wu Chun‐Chieh , Yang Jeng‐Fu , Chen Yu‐Kuei , Chai Chee‐Yin , Chiu Yu‐Wen , Huang Chia‐Tsuan , Lee Tzu‐Chi , Wu Ming‐Tsang
Published: August 2012

This study aims to explore whether certain occupations were associated with the risk of esophageal squamous cell carcinoma (ESCC) in Taiwan. In a hospital‐based case‐control study, we collected 326 newly diagnosed ESCC patients and 386 age‐matched controls (the ratio of case patients: controls = 1:1–2). All respondents completed a questionnaire, including 33 occupations in which environments potential exposure to cancer‐related hazards are present. Workers with dust and metal exposure were categorized into Groups A and B, respectively. Relative risks for ESCC were estimated by odds ratios adjusting for covariates (AOR). Compared with the controls, farmer/gardener (AOR = 2.08, 95% CI = 1.02–4.24) and workers in Group A (AOR = 2.80, 95% CI = 1.21–6.47) had significantly higher risk for developing ESCC. A tendency of increased risk was also found in workers in group B (OR = 5.72 95% CI = 2.33–14.03), but such association was not significant after adjusting for other covariates (AOR = 1.57, 95% CI = 0.54–6.61). Our results suggested that farmer/gardener and workers with exposure to dust had a significant excess risk of ESCC. This study added further evidence to the current knowledge that occupational hazards are important in the development of ESCC.
ON A WEAKLY UNIFORMLY ROTUND DUAL OF A BANACH SPACE
Authors: GILES J. R.
Published: August 2012

Every Banach space with separable second dual can be equivalently renormed to have weakly uniformly rotund dual. Under certain embedding conditions a Banach space with weakly uniformly rotund dual is reflexive.
High intakes of protein and processed meat associate with increased incidence of type 2 diabetes
Authors: Ericson Ulrika , Sonestedt Emily , Gullberg Bo , Hellstrand Sophie , Hindy George , Wirfält Elisabet , Orho-Melander Marju
Published: August 2012

Diets high in protein have shown positive effects on short-term weight reduction and glycaemic control. However, the understanding of how dietary macronutrient composition relates to long-term risk of type 2 diabetes is limited. The aim of the present study was to examine intakes of macronutrients, fibre and protein sources in relation to incident type 2 diabetes. In total, 27 140 individuals, aged 45–74 years, from the population-based Malmö Diet and Cancer cohort, were included. Dietary data were collected with a modified diet history method, including registration of cooked meals. During 12 years of follow-up, 1709 incident type 2 diabetes cases were identified. High protein intake was associated with increased risk of type 2 diabetes (hazard ratio (HR) 1·27 for highest compared with lowest quintile; 95 % CI 1·08, 1·49; P for trend = 0·01). When protein consumption increased by 5 % of energy at the expense of carbohydrates (HR 1·20; 95 % CI 1·09, 1·33) or fat (HR 1·21; 95 % CI 1·09, 1·33), increased diabetes risk was observed. Intakes in the highest quintiles of processed meat (HR 1·16; 95 % CI 1·00, 1·36; P for trend = 0·01) and eggs (HR 1·21; 95 % CI 1·04, 1·41; P for trend = 0·02) were associated with increased risk. Intake of fibre-rich bread and cereals was inversely associated with type 2 diabetes (HR 0·84; 95 % CI 0·73, 0·98; P for trend = 0·004). In conclusion, results from the present large population-based prospective study indicate that high protein intake is associated with increased risk of type 2 diabetes. Replacing protein with carbohydrates may be favourable, especially if fibre-rich breads and cereals are chosen as carbohydrate sources.
Thermonuclear burn of DT and DD fuels using three-temperature model: Non-equilibrium effects
Authors: Nayak Bishnupriya , Menon S.V.G.
Published: August 2012

Conditions for thermonuclear ignition are determined by three parameters: fuel density, temperature and hot-spot size. A simple three temperature model is developed to calculate the critical burn-up parameter or the minimum ρR product. Extensive results obtained are compared with earlier one temperature model for DT and DD fuels. While the two approaches are found to provide similar results for DT fuel except at low temperature regime (~10 keV), three temperature modeling is found to be necessary for DD fuel. This is argued to be due to the lower fusion reactivity and energy production in DD reactions.
Single Institutional Experience of Electron Conformal Therapy (ECT) and Modulated Electron Therapy (MET) for Post-mastectomy Chest Wall Irradiation
Authors: Tunio Mutahir , Ahmed Zaeem , Zameer Asad , Ali Shoukat , Awan Kamran A. , Khan Basit
Published: August 2012

Objective: Two opposed tangential photon beams followed by scar boost with electrons is a common technique for post-mastectomy radiotherapy to the chest wall. However with current advances in x-rays (conformal and intensity modulated radiotherapy), the electrons have gained less attention; and most of the centres are using the conventional electron therapy techniques. Here we share our experience of electron conformal therapy (ECT) and modulated electron therapy (MET) for post-mastectomy scar boost.

Materials and methods: For post-mastectomy chest wall irradiation, 25 patients were treated with ECT and MET in five steps (a) virtual simulation and image acquisition using CT scanner Siemens® followed by (b) data transfer to Coherence Siemens® for contouring of skin, clinical target volume (CTV), planning target volume (PTV) and organs at risk (OARs), followed by (c) forward and reverse planning applying segmented fields using Prowess Panther treatment planning system (TPS) Siemens® and shaping of fields on beam’s eye view (BEV), (d) data transfer to computer assisted fabrication device (Autimo 2D) for lead cut outs and wax blocks and finally (e) quality assurance (QA) and modified treatment delivery.

Results: Apart from energy selection and tumor delineation, the ECT and MET showed maximal sparing of OARs (< 70% of prescribed dose), and improved dose conformity compared to single energy single field plans. Phantom and in vivo dosimetric measurements showed excellent agreement with calculated doses with difference ±2%. Conformity improved little beyond allowing three energies due to energy overlap and field-size constraints and conformity improvement was found at the expanse of dose heterogeneity within the PTV.

Conclusions: ECT and MET is time saving and can be utilised for treating superficial targets to improve the treatment outcome and with better QA; however, efforts are required to design commercially available eMLC (electron multileaf collimators) in modern linear accelerators.
Negative Priming Persists in the Absence of Response-Retrieval
Authors: Ihrke Matthias , Behrendt Jörg , Schrobsdorff Hecke , Visser Ingmar , Hasselhorn Marcus
Published: August 2012

The hypothesis that retrieval of the prime response is responsible for the negative priming (NP) effect has gained popularity in recent studies of visual identity NP. In the current study we report an experiment in which we aimed to remove the response from the prime memory trace by means of spatio-temporal separation. Compared to an identical experiment without this separation ( Ihrke et al., 2011 ), we find that the response-retrieval-specific interaction is absent indicating that the separation was successful in preventing response-retrieval. Still, both negative and positive priming are present as main effects which show that processes other than response-retrieval can produce NP. In addition, based on recordings of the eye-movements during task processing, we localize the NP effect in a target-selection process while positive priming manifests in facilitated response-selection. Our results are in line with a multiple-route view of NP.
Seasonal inflow of warm water onto the southern Weddell Sea continental shelf, Antarctica
Authors: Årthun Marius , Nicholls Keith W. , Makinson Keith , Fedak Michael A. , Boehme Lars
Published: August 2012

To capture the austral summer to winter transition in water mass properties over the southern Weddell Sea continental shelf and slope region, 19 Weddell seals were tagged with miniaturized conductivity–temperature–depth sensors in February 2011. During the following 8 months the instruments yielded about 9000 temperature–salinity profiles from a previously undersampled area. This allows, for the first time, a description of the seasonality of warm water intrusions onto the shelf, as well as its southward extent towards the Filchner Ice Shelf. A temperature section across the Filchner Depression and eastern shelf shows a pronounced decrease in warm water inflow from summer to winter, further supported by an almost 3–year long time series from a shelf–break mooring. The seasonal variability is related to the surface wind stress and an associated deepening of the off‐shelf core of Warm Deep Water.
Wave‐driven sea level anomalies at the Midway tide gauge as an index of North Pacific storminess over the past 60 years
Authors: Aucan J. , Hoeke R. , Merrifield M. A.
Published: August 2012

Sixty years of sea‐level data collected in the interior lagoon of Midway Atoll in the northern Hawaiian Islands are used to examine short‐term (<2 days), high amplitude (up to 1 m) sea level anomaly (SLA) events that occur during the winter months. A combination of wind and wave model hindcasts, satellite altimetry product and in‐situ water level data confirms that these high SLA events are driven primarily by the arrival of energetic swell waves generated by storms in the North Pacific as breaking waves on the northwest side of the atoll lead to the setup of the lagoon. The number of high SLA events recorded in Midway during each winter season correlates well with the storminess in the Central North Pacific, defined as the mean seasonal wave height. This leads us to conclude that the seasonal number of high SLA events measured at this specific tide gauge in Midway can be used as an index of storminess in the Central North Pacific over climatic time‐scales. Our Midway‐based index of storminess correlates well with the Pacific Decadal Oscillation (PDO) index, and its observed increase over the past 60 years is attributed to variability associated with the PDO rather than a long‐term trend.
Environmental factors influential to the duration and intensity of tornadoes in simulated supercells
Authors: Naylor Jason , Gilmore Matthew S.
Published: August 2012

Simulations were performed using an idealized cloud model to investigate the environmental conditions influential to tornado duration and intensity. The results from twenty‐one tornadic simulations are presented—far more than any previous study. The results show a nearly linear relationship between storm relative environmental helicity (SREH) and simulated tornado duration. A multiple linear regression analysis was performed showing that, in addition to SREH, convective available potential energy (CAPE), convective inhibition (CIN), and precipitable water (Pwat) are useful predictor variables for simulated tornado duration. Similar results were found for simulated tornado intensity, as represented by the maximum central pressure drop.
Triggering of tremors and slow slip event in Guerrero, Mexico, by the 2010 Mw 8.8 Maule, Chile, earthquake
Authors: Zigone Dimitri , Rivet Diane , Radiguet Mathilde , Campillo Michel , Voisin Christophe , Cotte Nathalie , Walpersdorf Andrea , Shapiro Nikolai M. , Cougoulat Glenn , Roux Philippe , Kostoglodov Vladimir , Husker Allen , Payero Juan S.
Published: August 2012

We investigate the triggering of seismic tremor and slow slip event in Guerrero (Mexico) by the February 27, 2010 Maule earthquake (Mw 8.8). Triggered tremors start with the arrival of S wave generated by the Maule earthquake, and keep occurring during the passing of ScS, SS, Love and Rayleigh waves. The Rayleigh wave dispersion curve footprints the high frequency energy envelope of the triggered tremor, indicating a strong modulation of the source of tremors by the passing surface wave. This correlation and modulation by the passing waves is progressively lost with time over a few hours. The tremor activity continues during the weeks/months after the earthquake. GPS time series suggest that the second sub‐event of the 2009–2010 SSE in Guerrero is actually triggered by the Maule earthquake. The southward displacement of the GPS stations starts coincidently with the earthquake and tremors. The long duration of tremors indicate a continuing deformation process at depth, which we propose to be the second sub‐event of the 2009–2010 SSE. We show a quasi‐systematic correlation between surface displacement rate measured by GPS and tremor activity, suggesting that the NVT are controlled by the variations in the slip history of the SSE. This study shows that two types of tremors emerge: (1) Those directly triggered by the passing waves and (2) those triggered by the stress variations associated with slow slip. This indicates the prominent role of aseismic creep in the Mexican subduction zone response to a large teleseismic earthquake, possibly leading to large‐scale stress redistribution.
Determination of the Earth's pole tide Love number k2 from observations of polar motion using an adaptive Kalman filter approach
Authors: Seitz F. , Kirschner S. , Neubersch D.
Published: August 2012

The geophysical interpretation of observed time series of Earth rotation parameters (ERP) is commonly based on numerical models that describe and balance variations of angular momentum in various subsystems of the Earth. Naturally, models are dependent on geometrical, rheological and physical parameters. Many of these are weakly determined from other models or observations. In our study we present an adaptive Kalman filter approach for the improvement of parameters of the dynamic Earth system model DyMEG which acts as a simulator of ERP. In particular we focus on the improvement of the pole tide Love number k2. In the frame of a sensitivity analysis k2 has been identified as one of the most crucial parameters of DyMEG since it directly influences the modeled Chandler oscillation. At the same time k2 is one of the most uncertain parameters in the model. Our simulations with DyMEG cover a period of 60 years after which a steady state of k2 is reached. The estimate for k2, accounting for the anelastic response of the Earth's mantle and the ocean, is 0.3531 + 0.0030i. We demonstrate that the application of the improved parameter k2 in DyMEG leads to significantly better results for polar motion than the original value taken from the Conventions of the International Earth Rotation and Reference Systems Service (IERS).
Transport of Biogenic Amine Neurotransmitters at the Mouse Blood–Retina and Blood–Brain Barriers by Uptake1 and Uptake2
Authors: André Pascal , Saubaméa Bruno , Cochois-Guégan Véronique , Marie-Claire Cynthia , Cattelotte Julie , Smirnova Maria , Schinkel Alfred H , Scherrmann Jean-Michel , Cisternino Salvatore
Published: August 2012

Uptake1 and uptake2 transporters are involved in the extracellular clearance of biogenic amine neurotransmitters at synaptic clefts. We looked for them at the blood–brain barrier (BBB) and blood–retina barriers (BRB), where they could be involved in regulating the neurotransmitter concentration and modulate/terminate receptor-mediated effects within the neurovascular unit (NVU). Uptake2 (Oct1-3/Slc22a1-3, Pmat/Slc29a4) and Mate1/Slc47a1 transporters are also involved in the transport of xenobiotics. We used in situ carotid perfusion of prototypic substrates like [3H]-1-methyl-4-phenylpyridinium ([3H]-MPP+), [3H]-histamine, [3H]-serotonin, and [3H]-dopamine, changes in ionic composition and genetic deletion of Oct1-3 carriers to detect uptake1 and uptake2 at the BBB and BRB. We showed that uptake1 and uptake2 are involved in the transport of [3H]-dopamine and [3H]-MPP+ at the blood luminal BRB, but not at the BBB. These functional studies, together with quantitative RT-PCR and confocal imaging, suggest that the mouse BBB lacks uptake1 (Net/Slc6a2, Dat/Slc6a3, Sert/Slc6a4), uptake2, and Mate1 on both the luminal and abluminal sides. However, we found evidence for functional Net and Oct1 transporters at the luminal BRB. These heterogeneous transport properties of the brain and retina NVUs suggest that the BBB helps protect the brain against biogenic amine neurotransmitters in the plasma while the BRB has more of a metabolic/endocrine role.
Hsp90 rescues PTK6 from proteasomal degradation in breast cancer cells
Authors: Kang Shin-Ae , Cho Hyun-Soo , Yoon Jong Bok , Chung In Kwon , Lee Seung-Taek
Published: August 2012

PTK6 [protein tyrosine kinase 6; also known as Brk (breast tumour kinase)] is a non-receptor tyrosine kinase, closely related to Src, but evolutionarily distinct, that is up-regulated in various cancers, including breast cancer. Hsp90 (heat-shock protein 90) was identified as a PTK6-interacting protein in HEK (human embryonic kidney)-293 cells overexpressing PTK6. Hsp90 interacted with the PTK6 tyrosine kinase catalytic domain, but catalytic activity was not required for the interaction. Geldanamycin, an Hsp90 inhibitor, significantly decreased the PTK6 protein level through proteasome-dependent degradation, but did not affect the level of Src. Geldanamycin treatment also decreased phosphorylation of PTK6 substrates due to reduced amounts of PTK6. Moreover, overexpression of CHIP [C-terminus of Hsc70 (heat-shock cognate 70)-interacting protein], a chaperone-dependent E3 ligase, enhanced proteosomal degradation of PTK6. Geldanamycin increased the interaction of PTK6 with CHIP, but decreased the interaction of PTK6 with Hsp90. We also found that endogenous PTK6 associated with Hsp90 and geldanamycin decreased expression of endogenous PTK6 in breast carcinoma cells. Finally, we report that silencing endogenous CHIP expression in breast carcinoma cells inhibited geldanamycin-induced PTK6 reduction. These results demonstrate that Hsp90 plays an essential role in regulating PTK6 stability and suggest that Hsp90 inhibitors may be useful as therapeutic drugs for PTK6-positive cancers, including breast cancer.
Mapping the N-glycome of human von Willebrand factor
Authors: Canis Kevin , McKinnon Thomas A. J. , Nowak Agata , Haslam Stuart M. , Panico Maria , Morris Howard R. , Laffan Mike A. , Dell Anne
Published: August 2012

vWF (von Willebrand factor) is a key component for maintenance of normal haemostasis, acting as the carrier protein of the coagulant Factor VIII and mediating platelet adhesion at sites of vascular injury. There is ample evidence that vWF glycan moieties are crucial determinants of its expression and function. Of particular clinical interest, ABH antigens influence vWF plasma levels according to the blood group of individuals, although the molecular mechanism underlying this phenomenon remains incompletely understood. The present paper reports analyses of the human plasma vWF N-glycan population using advanced MS. Glycomics analyses revealed approximately 100 distinct N-glycan compositions and identified a variety of structural features, including lactosaminic extensions, ABH antigens and sulfated antennae, as well as bisecting and terminal GlcNAc residues. We estimate that some 300 N-glycan structures are carried by human vWF. Glycoproteomics analyses mapped ten of the consensus sites known to carry N-glycans. Glycan populations were found to be distinct, although many structural features were shared across all sites. Notably, the H antigen is not restricted to particular N-glycosylation sites. Also, the Asn2635 site, previously designated as unoccupied, was found to be highly glycosylated. The delineation of such varied glycan populations in conjunction with current models explaining vWF activity will facilitate research aimed at providing a better understanding of the influence of glycosylation on vWF function.
Recirculation zone dynamics of a transversely excited swirl flow and flame
Authors: O’Connor Jacqueline , Lieuwen Tim
Published: August 2012

This work investigates the response of the vortex breakdown region of a swirling, annular jet to transverse acoustic excitation for both non-reacting and reacting flows. This swirling flow field consists of a central vortex breakdown region, two shear layers, and an annular fluid jet. The vortex breakdown bubble, a region of highly turbulent recirculating flow in the center of the flowfield, is the result of a global instability of the swirling jet. Additionally, the two shear layers originating from the inner and outer edge of the annular nozzle are convectively unstable and rollup due to the Kelvin-Helmholtz instability. Unlike the convectively unstable shear layers that respond in a monotonic manner to acoustic forcing, the recirculation zone exhibits a range of response characteristics, ranging from minimal response to exhibiting abrupt bifurcations at large forcing amplitudes. In this study, the response of the time-average and fluctuating recirculation zone is measured as a function of forcing frequency, amplitude, and symmetry. The time-average flow field is shown to exhibit both monotonically varying and abrupt bifurcation features as acoustic forcing amplitude is increased. The unsteady motion in the recirculation zone is dominated by the low frequency precession of the vortex breakdown bubble. In the unforced flow, the azimuthal m = −2 and m = −1 modes (i.e., disturbances rotating in the same direction as the swirl flow) dominate the velocity disturbance field. These modes correspond to large scale deformation of the jet column and two small-scale precessing vortical structures in the recirculation zone, respectively. The presence of high amplitude acoustic forcing changes the relative amplitude of these two modes, as well as the character of the self-excited motion. For the reacting flow problem, we argue that the direct effect of these recirculation zone fluctuations on the flame response to flow forcing is not significant. Rather, flame wrinkling in response to flow forcing is dominated by shear layer disturbances. Recirculation zone dynamics primarily influence the time-average flame features (such as spreading angle). These influences on the flame response are indirect, as they control the transfer function relating shear layer fluctuations and the resulting flame response.
Mitigation of preferential concentration of small inertial particles in stationary isotropic turbulence using electrical and gravitational body forces
Authors: Karnik Aditya U. , Shrimpton John S.
Published: August 2012

Particles with a certain range of Stokes numbers preferentially concentrate due to action of turbulent motion and body forces such as gravity are known to influence this process. The effect of electric charge, residing on particles, upon the phenomenon of preferential concentration is investigated. We use direct numerical simulations of one-way coupled stationary isotropic turbulence over a range of particle Stokes numbers, fluid Taylor Reynolds numbers, and electrical and gravitational particle body force magnitudes, the latter characterized by non-dimensional settling velocities, $v_c^*$vc* and $v_g^*$vg*, respectively. In contrast to the gravitational body force, the electrical analogue, acting on an electrically charged particle, is generated by an electric field, which is in turn a function of the degree of preferential concentration. Thus, the electrical body force is created by, and mitigates, preferential concentration. In the absence of gravity, it is estimated that $v_c^*$vc* ≈ 1.0 is sufficient to homogenise a preferentially concentrated particle distribution. It is seen that charging drastically reduces the radial distribution function values at Kolmogorov scale separations, which gravitational force does not. This implies that charging the particles is an efficient means to destroy small clusters of particles. On incorporating the gravitational force, the amount of charge required to homogenise the particle distribution is reduced. It is estimated that $v_c^*$vc* ≈ 0.6 is sufficient to homogenise particle distribution at $v_g^*$vg* = 2.0. This estimation is corroborated by several different indicators of preferential concentration, and the results also agree reasonably well with corresponding experiments reported in literature. Calculations also suggest that sprays generated by practical charge injection atomizers would benefit from this electrical dispersion effect.
How to recover Marcus theory with fewest switches surface hopping: Add just a touch of decoherence
Authors: Landry Brian R. , Subotnik Joseph E.
Published: August 2012

We present a slightly improved version of our augmented fewest switches surface hopping (A-FSSH) algorithm and apply it to the calculation of transition rates between diabatic electronic states within the spin-boson model. We compare A-FSSH rates with (i) Marcus rates from the golden rule, (ii) Tully-style FSSH rates, and (iii) FSSH rates using a simple, intuitive decoherence criterion. We show that unlike FSSH, A-FSSH recovers the correct scaling with diabatic coupling (quadratic in V) as well as the lack of dependence on harmonic frequency ω for small enough values of ω and large enough temperatures.
First-principles theoretical analysis of transition-metal doping of ZnSe quantum dots
Authors: Singh Tejinder , Mountziaris T. J. , Maroudas Dimitrios
Published: August 2012

We present a systematic analysis of the underlying mechanism of transition-metal doping in ZnSe nanocrystals, using first-principles density functional theory calculations. Our analysis focuses on the adsorption and surface segregation of Mn dopants on ZnSe nanocrystal surface facets. We find that the chemical potentials of the growth precursor species determine the surface structure and morphology of the nanocrystals. We report binding energies for Mn adsorption onto ZnSe surfaces and find that all the anion-rich surfaces contribute toward dopant adsorption onto ZnSe nanocrystal surface facets. Beyond a critical value of dopant surface coverage, these adsorbed dopants may induce structural transitions in low-Miller-index surface facets, resulting in morphological transitions of the ZnSe nanocrystals. In addition, the dopant binding-energy dependence on the dopant surface concentration explains the doping difficulties during nanocrystal growth. Finally, we report surface segregation energy profiles for Mn dopant segregation on low-Miller-index ZnSe nanocrystal surface facets. We find that, under conditions that render ZnSe(001)-(2 × 1) as the dominant dopable surface of ZnSe nanocrystals, Mn dopants do not have a tendency to segregate on this surface; this guarantees that the dopants remain incorporated into the core regions of the nanocrystal instead of escaping to the surface.
Room temperature electromechanical and magnetic investigations of ferroelectric Aurivillius phase Bi5Ti3(FexMn1−x)O15 (x = 1 and 0.7) chemical solution deposited thin films
Authors: Keeney Lynette , Groh Claudia , Kulkarni Santosh , Roy Saibal , Pemble Martyn E. , Whatmore Roger W.
Published: August 2012

Aurivillius phase thin films of Bi5Ti3(FexMn1−x)O15 with x = 1 (Bi5Ti3FeO15) and 0.7 (Bi5Ti3Fe0.7Mn0.3O15) on SiO2-Si(100) and Pt/Ti/SiO2-Si substrates were fabricated by chemical solution deposition. The method was optimized in order to suppress formation of pyrochlore phase Bi2Ti2O7 and improve crystallinity. The structural properties of the films were examined by x-ray diffraction, scanning electron microscopy, and atomic force microscopy. Optimum crystallinity and pyrochlore phase suppression was achieved by the addition of 15 to 25 mol. % excess bismuth to the sols. Based on this study, 17.5 mol. % excess bismuth was used in the preparation of Bi2Ti2O7-free films of Bi5Ti3FeO15 on SrTiO3(100) and NdGaO3(001) substrates, confirming the suppression of pyrochlore phase using this excess of bismuth. Thirty percent of the Fe3+ ions in Bi5Ti3FeO15 was substituted with Mn3+ ions to form Bi2Ti2O7-free thin films of Bi5Ti3Fe0.7Mn0.3O15 on Pt/Ti/SiO2-Si, SiO2-Si(100), SrTiO3(100), and NdGaO3(001) substrates. Bi5Ti3FeO15 and Bi5Ti3Fe0.7Mn0.3O15 thin films on Pt/Ti/SiO2-Si and SiO2-Si(100) substrates were achieved with a higher degree of a-axis orientation compared with the films on SrTiO3(100) and NdGaO3(001) substrates. Room temperature electromechanical and magnetic properties of the thin films were investigated in order to assess the potential of these materials for piezoelectric, ferroelectric, and multiferroic applications. Vertical piezoresponse force microscopy measurements of the films demonstrate that Bi5Ti3FeO15 and Bi5Ti3Fe0.7Mn0.3O15 thin films are piezoelectric at room temperature. Room temperature switching spectroscopy-piezoresponse force microscopy measurements in the presence and absence of an applied bias demonstrate local ferroelectric switching behaviour (180°) in the films. Superconducting quantum interference device magnetometry measurements do not show any room temperature ferromagnetic hysteresis down to an upper detection limit of 2.53 × 10−3 emu; and it is concluded, therefore, that such films are not mutiferroic at room temperature. Piezoresponse force microscopy lithography images of Bi5Ti3Fe0.7Mn0.3O15 thin films are presented.
Crystal structure and electronic structure of quaternary semiconductors Cu2ZnTiSe4 and Cu2ZnTiS4 for solar cell absorber
Authors: Wang Xiaofeng , Li Junjie , Zhao Zhenjie , Huang Sumei , Xie Wenhui
Published: August 2012

We design two new I2-II-IV-VI4 quaternary semiconductors Cu2ZnTiSe4 and Cu2ZnTiS4, and study the crystal and electronic structure by employing first-principles electronic structure calculations. Among the considered crystal structures, it is confirmed that the band gaps of Cu2ZnTiSe4 and Cu2ZnTiS4 originate from the full occupied Cu 3d valence band and unoccupied Ti 3d conducting band, and kesterite structure should be the ground state. Furthermore, our calculations indicate that Cu2ZnTiSe4 and Cu2ZnTiS4 have comparable band gaps with Cu2ZnTSe4 and Cu2ZnTS4, but almost twice larger absorption coefficient α(ω). Thus, the materials are expected to be candidate materials for solar cell absorber.
Frequency multiplexed superconducting quantum interference device readout of large bolometer arrays for cosmic microwave background measurements
Authors: Dobbs M. A. , Lueker M. , Aird K. A. , Bender A. N. , Benson B. A. , Bleem L. E. , Carlstrom J. E. , Chang C. L. , Cho H.-M. , Clarke J. , Crawford T. M. , Crites A. T. , Flanigan D. I. , de Haan T. , George E. M. , Halverson N. W. , Holzapfel W. L. , Hrubes J. D. , Johnson B. R. , Joseph J. , Keisler R. , Kennedy J. , Kermish Z. , Lanting T. M. , Lee A. T. , Leitch E. M. , Luong-Van D. , McMahon J. J. , Mehl J. , Meyer S. S. , Montroy T. E. , Padin S. , Plagge T. , Pryke C. , Richards P. L. , Ruhl J. E. , Schaffer K. K. , Schwan D. , Shirokoff E. , Spieler H. G. , Staniszewski Z. , Stark A. A. , Vanderlinde K. , Vieira J. D. , Vu C. , Westbrook B. , Williamson R.
Published: August 2012

A technological milestone for experiments employing transition edge sensor bolometers operating at sub-Kelvin temperature is the deployment of detector arrays with 100s–1000s of bolometers. One key technology for such arrays is readout multiplexing: the ability to read out many sensors simultaneously on the same set of wires. This paper describes a frequency-domain multiplexed readout system which has been developed for and deployed on the APEX-SZ and South Pole Telescope millimeter wavelength receivers. In this system, the detector array is divided into modules of seven detectors, and each bolometer within the module is biased with a unique ∼MHz sinusoidal carrier such that the individual bolometer signals are well separated in frequency space. The currents from all bolometers in a module are summed together and pre-amplified with superconducting quantum interference devices operating at 4 K. Room temperature electronics demodulate the carriers to recover the bolometer signals, which are digitized separately and stored to disk. This readout system contributes little noise relative to the detectors themselves, is remarkably insensitive to unwanted microphonic excitations, and provides a technology pathway to multiplexing larger numbers of sensors.
Pt3 and Pt4 clusters on graphene monolayers supported on a Ni(111) substrate: Relativistic density-functional calculations
Authors: Błoński Piotr , Hafner Jürgen
Published: August 2012

Density-functional theory including spin-orbit coupling and corrections for dispersion forces has been used to investigate the structural and magnetic properties of Pt3 and Pt4 clusters deposited on a graphene layer supported on a Ni(111) substrate. It is shown that the strong interaction of the Pt atoms with the Ni-supported graphene stabilizes a flat triangular and a slightly bent rhombic structure of the clusters. Pt atoms are located nearly on top of the C atoms of the graphene layer, slightly shifted towards the bridge positions because the Pt–Pt distances are larger than the C–C distances of the graphene sheet lattice-matched to the Ni support. The strong interaction with the substrate leads to a substantial reduction of both the spin and orbital moments of the Pt atoms, not only compared to the clusters in the gas-phase, but also compared to those adsorbed on a freestanding graphene layer. The trends in the magnetic moments and in the magnetic anisotropy of the cluster/substrate complex have been analyzed and it is demonstrated that the anisotropy is dominated by the Ni support.
Strong stretching theory for diblock copolymers in thin films under application of electric fields
Authors: Harrach Michael F. , Heckmann Marianne , Drossel Barbara
Published: August 2012

We investigate the microphases of asymmetric AB diblock copolymers confined to thin films in the strong segregation limit under the application of electric fields. We evaluate the free energy of a given set of possible phases and present phase diagrams for diblock copolymers with a cylindrical bulk phase in dependence of the film thickness and the attraction between the confining walls and the A or B monomers. This is done for different field strengths and volume fractions. We find that with increasing field strength structures show a preference for alignment with the field. The alignment is stronger when the permittivity of the minority monomer is larger than that of the majority monomer. Depending on the strength of the wall potential and the film thickness, the walls can become completely wetted by the minority monomer.