bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective sampling of electron energy distributions using higher order sampling and spline function
Authors: Kimura Taro , Satoh Kohki , Itoh Hidenori
Published: November 2011

A novel method for sampling an electron energy distribution with good statistics in Monte Carlo simulations (MCS) using Higher Order Sampling and a spline function is developed. The electron energy distributions f(ϵ) obtained by the developed method are in excellent agreement with those obtained by conventional sampling methods in equilibrium and nonequilibrium regions. The sampling method is extended to two dimensional, and applied to the sampling of the spatial variation of the energy distribution f(ϵ, x) in a steady‐state Townsend experiment. The obtained energy distributions are in good agreement with those resulting from the conventional method. We found that the traced electron number in an MCS can be reduced to one‐tenth of the conventional method by using the developed sampling method. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(12): 22–28, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10349
Aza‐Diels–Alder reaction between cyclopentadiene and protonated N‐phenylethyliminoacetates of 8‐phenylmenthol and 8‐phenylneomenthol: a density functional theory study
Authors: Miranda Margarida S. , Rodríguez‐Borges José E. , Esteves da Silva Joaquim C. G. , García‐Mera Xerardo
Published: November 2011

The cycloaddition between glyoxylate imines possessing two chiral auxiliaries, N‐(R)‐ or N‐(S)‐1‐phenylethyl and 8‐phenylmenthyl or 8‐phenylneomenthyl, and cyclopentadiene is described. Computational calculations using density functional theory with the Becke, three‐parameter, Lee–Yang–Parr functional and the 6‐31G(d) basis set were performed to better understand the highly diastereoselective mechanism and the exo‐selectivity observed experimentally for these ionic aza‐Diels–Alder reactions. Copyright © 2011 John Wiley & Sons, Ltd.
Thermolysis kinetics of diethyl 2,3‐dicyano‐2,3‐di(p‐substituted phenyl)succinates
Authors: Qi Chenze , Shao Linjun , Lu Yueqing , Wang Chen , Zhang Xian‐Man
Published: November 2011

An experimental approach was developed to determine the intrinsic thermolysis rate constants of the central carbon–carbon bond during the dl/meso isomerization of diethyl 2,3‐dicyano‐2,3‐di(p‐substituted phenyl)succinates (G=H, Me, OMe, Cl, and NO2) at temperatures ranging from 80 to 120 °C. The obtained rate constants are significantly affected by the polarity of the para substituents, in sharp contrast to their negligible effects on the dl/meso isomerization equilibrium constants. Moreover, the substituent effects on the activation enthalpies can be linearly correlated with the Hammett substituent resonance constants and the homolytic dissociation enthalpies (bond dissociation energies) of the benzylic C–H bonds of ethyl 2‐cyano‐2‐(p‐substituted phenyl)acetates. Copyright © 2011 John Wiley & Sons, Ltd.
The integrated effects of temperature and stress on the formation of carbon linear atomic chains from graphene nanoribbons
Authors: Zhu Jianwei , Shi Daning
Published: November 2011

In situ experiments for graphene nanoribbons (GNRs) under electron beam irradiation show their thinning process. In particular, carbon linear atomic chains (LACs) were observed with high resolution transmission electron microscopy. In order to further understand the structural evolution and breaking mechanisms under stress and a wide range of temperatures that are yet to be fully explored by experiments, we use a molecular dynamics (MD) method to simulate the mechanical properties of GNRs. At high temperatures, our simulations produce non-hexagons and long LACs, whose main features are similar to the experimental results. We show how defects lead to the formation of definitely stable LACs, while at low temperatures, tensile deformation modes become brittle due to localized defects, which are attributed to insufficient thermal energy. In the simulation of zigzag GNRs at high temperatures, we unexpectedly obtained a fracture of the armchair-zigzag bridge connected by non-hexagons. These results offer insights for nanoelectronic device fabrication through a stress-temperature-controlled procedure on GNRs.
Discrete microfluidics transfer across capillaries using liquid bridge stability
Authors: Kok Keung Lye Jonathan , Wah Ng Tuck , Yeong Liang Ling William
Published: November 2011

Discrete microfluidics offers distinct advantages over continuous microfluidics since the need for flow presents significant problems. Here, we demonstrate a method of achieving the gentle transfer of liquid samples between two capillaries with the use of air actuation which limits flow and is amenable to automation. Since the stability of liquid bridges is in operation, there is a relationship established between the gap distance and the liquid volume, thereby resulting in three physical response types that were identified. Only one of these allows for efficient liquid transfer. We advance a model for the optimal gap distance and show that it is in good agreement with the experimental data. During the process of liquid transfer, favorable mixing is also achieved.
Modeling of time-resolved coupled radiative and conductive heat transfer in multilayer semitransparent materials up to very high temperatures
Authors: Niezgoda M. , Rochais D. , Enguehard F. , Echegut P. , Rousseau B.
Published: November 2011

This paper presents an original modeling approach that enables the calculation of the temperature field within multilayer materials submitted to the flash method. The model takes into account the time-resolved coupled conducto-radiative heat transfer and the temperature of experiments. The compound can be subdivided into as many layers as desired, and their thicknesses and relevant physical properties can be chosen arbitrarily. Unconventional experimental thermograms can be reproduced faithfully by the calculations. This model, thus, makes it possible to correctly estimate the effective thermal diffusivity of semitransparent materials, thereby providing a deeper insight into the analysis of the physical phenomena involved.
Expression and mutational status of RON in neoplastic lesions of the breast: analysis of MSP/RON signaling in ductal carcinoma in situ and invasive ductal carcinoma
Authors: REN XIAOLIANG , DAA TSUTOMU , YADA NAOMI , KASHIMA KENJI , FUJITOMI YUTAKA , YOKOYAMA SHIGEO
Published: November 2011

Ren XL, Daa T, Yada N, Kashima K, Fujitomi Y, Yokoyama S. Expression and mutational status of RON in neoplastic lesions of the breast: analysis of MSP/RON signaling in ductal carcinoma in situ and invasive ductal carcinoma. APMIS 2012; 120: 358–67.

Recepteur d’origine nantais (RON) is a receptor tyrosine kinase closely related to MET and involved in tumorigenesis. We investigated the roles of aberrations in RON and its ligand, macrophage‐stimulating protein (MSP), in invasive ductal carcinoma (IDC, n = 81), ductal carcinoma in situ (DCIS, n = 26), and in benign lesions (n = 20) of mammary gland. Expression of RON and MSP was evaluated by immunohistochemistry and the mutational status of a region containing the proteolytic cleavage site in exon 1 and each exon of the kinase domain (exon 14–20) of RON was screened by polymerase chain reaction‐single strand conformational polymorphism (PCR‐SSCP) analysis. The proportion of cases positive for RON expression was significantly different between malignant [86% (92/107)] and benign [40% (8/20)] lesions. RON expression was positive in both IDC and DCIS [90% (73/81) and 73% (19/26), respectively], whereas MSP expression was present in 54% (44/81) of IDC and absent in DCIS. RON expression correlated significantly with the histological grade of DCIS. No mutations were detected in the examined regions of RON in breast cancer samples as confirmed by PCR‐SSCP. The findings suggest the involvement of RON expression in the development of breast cancer, and that an autocrine/paracrine loop of RON seems to affect tumor invasiveness.
Synchronization of a Single-phase Photovoltaic Generator With the Low-Voltage Utility Grid
Authors: Anani Nader , Al-Kharji Omar , Ponnapalli Prasad , Al-Araji Saleh , Al-Qutayri Mahmoud
Published: November 2011

The increased generation of electrical energy from renewable sources and its integration into the low voltage grid have necessitated regulations governing the connection of renewable energy generators to the grid. This was deemed necessary to preserve the integrity and the correct operation of the grid. This paper presents a new architecture of a hybrid phase lock loop circuit topology for synchronizing a single-phase inverter fed from a renewable energy source such as a photovoltaic (PV) generator to the low voltage grid. The system uses a digital phase lock loop (DPLL) architecture, which is based on the arctan phase detector, driving a phase lock loop (PLL) to synchronize a PV inverter with the grid. The proposed system has been tested by simulation using simulink/matlab. The test results demonstrate the ability of the system to synchronize a PV inverter with the grid and to re-establish synchronization following a sudden perturbation in the grid voltage such as a single or a multistep change in phase. The system is digital and can be readily implemented using an FPGA (field programmable gate array) and hence can be easily embedded in a home or small scale single-phase PV inverter.
Biochemical Disclosure of the Mycolate Outer Membrane of Corynebacterium glutamicum
Authors: Marchand Christophe H. , Salmeron Christophe , Bou Raad Roland , Méniche Xavier , Chami Mohamed , Masi Muriel , Blanot Didier , Daffé Mamadou , Tropis Marielle , Huc Emilie , Le Maréchal Pierre , Decottignies Paulette , Bayan Nicolas
Published: November 2011

Corynebacterineae
is a specific suborder of Gram-positive bacteria that includes
Mycobacterium tuberculosis
and
Corynebacterium glutamicum
. The cell wall of these bacteria is composed of a heteropolymer of peptidoglycan (PG) linked to arabinogalactan (AG), which in turn is covalently associated with an atypical outer membrane, here called mycomembrane (M). The latter structure has been visualized by cryo-electron microscopy of vitreous sections, but its biochemical composition is still poorly defined, thereby hampering the elucidation of its physiological function. In this report, we show for the first time that the mycomembrane-linked heteropolymer of PG and AG (M-AG-PG) of
C. glutamicum
can be physically separated from the inner membrane on a flotation density gradient. Analysis of purified M-AG-PG showed that the lipids that composed the mycomembrane consisted almost exclusively of mycolic acid derivatives, with only a tiny amount, if any, of phospholipids and lipomannans, which were found with the characteristic lipoarabinomannans in the plasma membrane. Proteins associated with or inserted in the mycomembrane were extracted from M-AG-PG with lauryl-dimethylamine-oxide (LDAO), loaded on an SDS-PAGE gel, and analyzed by tandem mass spectrometry or by Western blotting. Sixty-eight different proteins were identified, 19 of which were also found in mycomembrane fragments released by the terminal-arabinosyl-transferase-defective Δ
AftB
strain. Almost all of them are predicted to contain a signal sequence and to adopt the characteristic β-barrel structure of Gram-negative outer membrane proteins. These presumed mycomembrane proteins include the already-known pore-forming proteins (PorA and PorB), 5 mycoloyltransferases (cMytA, cMytB, cMytC, cMytD, and cMytF), several lipoproteins, and unknown proteins typified by a putative C-terminal hydrophobic anchor.
HIV-1 Nef compensates for disorganization of the immunological synapse by inducing trans-Golgi network–associated Lck signaling
Authors: Pan Xiaoyu , Rudolph Jochen M. , Abraham Libin , Habermann Anja , Haller Claudia , Krijnse-Locker Jacomine , Fackler Oliver T.
Published: November 2011

The Nef protein of HIV-1 facilitates viral replication and disease progression in vivo. Nef disturbs the organization of immunological synapses between infected CD4+ T lymphocytes and antigen-presenting B-lymphocytes to interfere with TCR proximal signaling. Paradoxically, Nef enhances distal TCR signaling in infected CD4+ T lymphocytes, an effect thought to be involved in its role in AIDS pathogenesis. Using quantitative confocal microscopy and cell fractionation of Nef-expressing cells and HIV-1–infected primary human T lymphocytes, we found that Nef induces intracellular compartmentalization of TCR signaling to adjust TCR responses to antigenic stimulation. Nef reroutes kinase-active pools of the TCR signaling master switch Lck away from the plasma membrane (PM) to the trans-Golgi network (TGN), thereby preventing the recruitment of active Lck to the immunological synapse after TCR engagement and limiting signal initiation at the PM. Instead, Nef triggers Lck-dependent activation of TGN-associated Ras-Erk signaling to promote the production of the T lymphocyte survival factor IL-2 and to enhance virus spread. Overexpression of the Lck PM transporter Unc119 restores Nef-induced subversions of Lck trafficking and TCR signaling. Nef therefore hijacks Lck sorting to selectively activate TGN-associated arms of compartmentalized TCR signaling. By tailoring T-lymphocyte responses to antigenic stimulation, Nef optimizes the environment for HIV-1 replication.
Development of a Risk-Stratification Tool for Medical Child Abuse in Failure to Thrive
Authors: Mash Constance , Frazier Thomas , Nowacki Amy , Worley Sarah , Goldfarb Johanna
Published: November 2011

OBJECTIVE:

To develop a risk-stratification tool to help identify medical child abuse (MCA) in children evaluated for failure to thrive (FTT).

PATIENTS AND METHODS:

In this case-control study, the control group consisted of children who were seen in the pediatric gastroenterology department and diagnosed with FTT before the age of 5 years between 2000 and 2010. Cases were distinguished by having also been referred to the Child Advocacy Committee at the Cleveland Clinic Foundation (CCF) and/or reported to the Department of Child and Family Services by the CCF as a possible case of MCA. We used retrospective chart review to compare 17 cases of MCA with 68 controls. Classification-tree analysis was used to generate the risk-stratification tool.

RESULTS:

A risk-stratification tool, in the form of a classification tree, was developed and incorporated the following individual risk indicators: (1) ≥5 organ systems involved; (2) absence of serious congenital anomaly or confirmed genetic disorder; (3) ≥5 reported allergies; and (4) refusal of services from a multidisciplinary feeding team. Overall, the classification tree had a sensitivity of 100% and a specificity of 96%.

CONCLUSIONS:

The results of this study suggest that a diagnosis of MCA may be suspected in children with FTT on the basis of features in the initial presentation and clinical course. Using the proposed risk-stratification tool that incorporates these features might assist in earlier identification of medically abused children and reduce morbidity and mortality.
Direct Electrochemistry of Hemoglobin Based on Fe3O4@SiO2 Nanoparticles Modified Electrode
Authors: Cui Rongjing , Yin Fan , Zhou Lijuan , Pan Hongcheng
Published: November 2011

A biosensor based on hemoglobin‐Fe3O4@SiO2 nanoparticle bioconjunctions modified indium‐tin‐oxide (Hb/Fe3O4@SiO2/ITO) electrode was fabricated to determine the concentration of H2O2. UV‐vis absorption spectra, fourier transform infrared (FT‐IR) spectroscopy, cyclic voltammetry (CV) and high‐resolution transmission electron microscopy (HRTEM) were used to characterize the bioconjunction of Fe3O4@SiO2 with Hb. Experimental results demonstrate that the immobilized Hb on the Fe3O4@SiO2 matrix retained its native structure well. In addition, Fe3O4@SiO2 nanoparticles (NPs) are very effective in facilitating electron transfer of the immobilized enzyme, which can be attributed to the unique nanostructure and larger surface area of the Fe3O4@SiO2 NPs. The biosensor displayed good performance for the detection of H2O2 with a wide linear range from 2.03×10−6 to 4.05×10−3 mol/L and a detection limit of 0.32 µmol/L. The resulting biosensor exhibited fast amperometric response, good stability, reproducibility, and selectivity to H2O2.
Maternal use of antibiotics and the risk of orofacial clefts: a nationwide cohort study
Authors: Mølgaard‐Nielsen Ditte , Hviid Anders
Published: November 2011

Purpose

To study the association between antibiotic use in early pregnancy and the risk of isolated orofacial clefts.

Methods

We conducted a cohort study of 806 011 live births in Denmark from 1996 through September 2008. Individual‐level information on prescribed antibiotics during pregnancy, orofacial cleft diagnosis, and possible confounders were ascertained from nationwide health registries. The main outcome measure was prevalence odds ratios (PORs) of orofacial clefts by exposure to antibiotics.

Results

Maternal use of any antibiotics in early pregnancy was not associated with an increased risk of cleft lip with or without cleft palate (CL/P) (POR, 1.08; 95%CI, 0.89–1.30) or cleft palate alone (CP) (POR, 1.14; 95%CI, 0.86–1.51). Further analyses of specific classes showed an increased risk of CL/P associated with 2nd month use of doxycycline/tetracycline (2 exposed cases; POR, 7.30; 95%CI, 1.81–29.46) and sulfamethizole (18 exposed cases; POR, 1.76; 95%CI, 1.10–2.81). An increased risk of CP was seen for first trimester use of trimethoprim (2 exposed cases; POR, 14.29; 95%CI, 3.46–59.05) and 3rd month use of pivmecillinam (9 exposed cases; POR, 2.34; 95%CI, 1.20–4.54).

Conclusion

Antibiotic use in early pregnancy was not a major risk factor for isolated orofacial clefts in our study. Some classes of antibiotics used in the critical period for development of CL/P and CP may increase the risk; however, other factors such as indications for use and chance may explain these findings. Copyright © 2011 John Wiley & Sons, Ltd.
Intrinsic defects and electronic conductivity of TaON: First-principles insights
Authors: Chen Shiyou , Wang Lin-Wang
Published: November 2011

Using hybrid functional calculations we show that TaON has different defect properties from the binary tantalum oxide and nitride: (i) instead of O or N vacancies or Ta interstitials, the ON antisite is the dominant defect, which determines its intrinsic n-type conductivity and the p-type doping difficulty; (ii) the ON antisite has a shallower donor level than O or N vacancies, with a delocalized distribution composed mainly of the Ta 5d orbitals, which gives rise to better electronic conductivity in the oxynitride than in the oxide and nitride. The phase stability analysis reveals that further oxidation of TaON is possible when the oxygen chemical potential is high (O rich); thus, a low oxygen partial pressure is required to synthesize stoichiometric TaON samples.
Effects of predator species, vegetation and prey assemblage on prey preferences of predators with emphasis on vulnerability of age‐0 common carp
Authors: WEBER M. J. , BROWN M. L.
Published: November 2011

Abstract  Predation is an important force structuring aquatic communities, but predator–prey interactions are complex and regulated by multiple factors. Invasive fishes may interact with native fishes to alter predator–prey preferences and community dynamics. For example, common carp, Cyprinus carpio L., is an invasive species that can become abundant and negatively affect aquatic ecosystems. Juvenile common carp are occasionally found in predator diets, but predator preferences for common carp compared with alternative prey remains unknown. Prey selection and feeding behaviour of five piscivores (flathead catfish, Pylodictis olivaris (Rafinesque); largemouth bass, Micropterus salmoides (Lacepède); smallmouth bass, M. dolomieu Lacepède; walleye, Sander vitreus (Mitchill); and northern pike, Esox lucius L.) foraging on juvenile common carp and two alternative prey (fathead minnow, Pimephales promelas Rafinesque, and yellow perch, Perca flavescens Mitchill) at variable densities and habitats were evaluated. Common carp and fathead minnow were generally selected for or neutrally selected across predator species, habitat types and prey assemblages. By contrast, yellow perch was generally selected against. Common carp were easily captured but difficult to manipulate and ingest compared with other prey. These results reveal that common carp are vulnerable to a variety of predators, suggesting control of this detrimental invader may be possible through biomanipulation.
Atomic layer deposition of Al2O3 on V2O5 xerogel film for enhanced lithium-ion intercalation stability
Authors: Liu Dawei , Liu Yanyi , Candelaria Stephanie L. , Cao Guozhong , Liu Jun , Jeong Yoon-Ha
Published: November 2011

V2O5 xerogel films were fabricated by casting V2O5 sols onto fluorine-doped tin oxide glass substrates at room temperature. Five, ten and twenty atomic layers of Al2O3 were grown onto as-fabricated films respectively. The bare film and Al2O3-deposited films all exhibited hydrous V2O5 phase only. Electrochemical impedance spectroscopy study revealed increased surface charge-transfer resistance of V2O5 films as more Al2O3 atomic layers were deposited. Lithium-ion intercalation tests at 600 mAg−1 showed that bare V2O5 xerogel film possessed high initial discharge capacity of 219 mAhg−1 but suffered from severe capacity degradation, i.e., having only 136 mAhg−1 after 50 cycles. After deposition of ten atomic layers of Al2O3, the initial discharge capacity was 195 mAhg−1 but increased over cycles before stabilizing; after 50 cycles, the discharge capacity was as high as 225 mAhg−1. The noticeably improved cyclic stability of Al2O3-deposited V2O5 xerogel film could be attributed to the improved surface chemistry and enhanced mechanical strength. During repeated lithium-ion intercalation/de-intercalation, atomic layers of Al2O3 which were coated onto V2O5 surface could prevent V2O5 electrode dissolution into electrolyte by reducing direct contact between active electrode and electrolyte while at the same time acting as binder to maintain good mechanical contact between nanoparticles inside the film.
The Impacts of Hg(II) Tightly Binding on the Alzheimer’s Tau Construct R3: Misfolding and Aggregation
Authors: Yang Dan-Jing , Shi Shuo , Yao Tian-Ming , Ji Liang-Nian
Published: November 2011

Mercury, a known neurotoxin, is increasingly believed to be relevant to trigger the pathological positive feedback circle of Alzheimer’s disease (AD). In this study, we originally set out to determine the possible mechanisms for Hg(II)-stimulated fibrillation of R3, which is pivotal to the biochemical properties of full tau protein. In an isothermal titration calorimetry experiment, we demonstrate that R3 shows high affinity to Hg(II), and it yields two types of coordination intermediates in the Hg(II)–R3 binding process. The exceptionally large magnitude of heat release suggests that the most possible coordinating site is the thiol group of cysteine residue (Cys322). By circular dichroism spectrum, we reveal that the coordination of Hg(II) significantly alters the conformation of natively unstructured R3, specifically from random coil to β-turn structure. Furthermore, we find that the tight binding of Hg(II) exerts a pronounced acceleration of the heparin-induced aggregation of R3, giving relatively more R3 filaments, by ThS fluorescence assay and electron microscopy. This investigation could help us to understand the detailed mechanism of misfolding development and self-aggregation of the tau protein from a toxicological perspective of metal ion to AD.
Theoretical Study of the Intramolecular Proton Transfer in the Tautomers of Cytosine Assisted by Water
Authors: Zheng Haitao , Zhao Dongxia , Yang Zhongzhi
Published: November 2011

Ab initio MP2 and DFT studies on the tautomers of cytosine and the related hydrated tautomers have been carried out. The ground‐state structures of four tautomers of cytosine and related transition states were fully optimized. The vibrational frequency analysis was performed on all the optimized structures. Detailed intrinsic reaction coordinate (IRC) calculations were carried out to guarantee the optimized transition‐state structures being connected to the related tautomers. We obtained the relative stability order for the tautomers of cytosine and the related hydrated tautomers. In the isolated and hydrated condition, the bond types of C(2)O(7) and C(4)N(8) greatly affect the stability of the cytosine tautomers. Moreover, we have explored the influence of the water molecules on the intramolecular proton transfer between the keto and enol forms of the cytosine tautomers. The first water molecule obviously decreases the isomerization activation energy for the monohydrated cytosine tautomers. It is shown that the isomerization energy barrier changes only a little when the second and third water molecules are added in the reaction loop. The solvent effects have an obvious influence on the proton‐transfer barrier of the isolated cytosine. However, the solvent effects seem to be insignificant for the isomerization energy barriers of the monohydrated, dihydrated and trihydrated cytosine. The water molecule in these complexes can be looked on as the explicit water. Therefore, the explicit water model may be more credible to explore the intramolecular proton transfer, in comparison with the PCM which is the implicit water model.
Molecular lesions in childhood and adult acute megakaryoblastic leukaemia
Authors: Hama Asahito , Muramatsu Hideki , Makishima Hideki , Sugimoto Yuka , Szpurka Hadrian , Jasek Monika , O’Keefe Christine , Takahashi Yoshiyuki , Sakaguchi Hirotoshi , Doisaki Sayoko , Shimada Akira , Watanabe Nobuhiro , Kato Koji , Kiyoi Hitoshi , Naoe Tomoki , Kojima Seiji , Maciejewski Jaroslaw P.
Published: November 2011

While acute megakaryoblastic leukaemia (AMKL) occurs in children with (DS‐AMKL) and without (paediatric non‐DS‐AMKL) Down syndrome, it can also affect adults without DS (adult non‐DS‐AMKL). We have analysed these subgroups of patients (11 children with DS‐AMKL, 12 children and four adults with non‐DS‐AMKL) for the presence of molecular lesions, including mutations and chromosomal abnormalities studied by sequencing and single nucleotide polymorphism array‐based karyotyping, respectively. In children, AMKL was associated with trisomy 21 (somatic in non‐DS‐AMKL), while numerical aberrations of chromosome 21 were only rarely associated with adult AMKL. DS‐AMKL was also associated with recurrent somatic gains of 1q (4/11 DS‐AMKL patients). In contrast to trisomy 21 and gains of 1q, other additional chromosomal lesions were evenly distributed between children and adults with AMKL. A mutational screen found GATA1 mutations in 11/12 DS‐AMKL, but mutations were rare in paediatric non‐DS‐AMKL (1/12) and adult AMKL (0/4). JAK3 (1/11), JAK2 (1/11), and TP53 mutations (1/11) were found only in patients with DS‐AMKL. ASXL1, IDH1/2, DNMT3A, RUNX1 and CBL mutations were not found in any of the patient group studied, while NRAS mutation was identified in two patients with paediatric non‐DS‐AMKL.
How Do I Remember That I Know You Know That I Know?
Authors: Rubin Rachael D. , Brown-Schmidt Sarah , Duff Melissa C. , Tranel Daniel , Cohen Neal J.
Published: November 2011

Communication is aided greatly when speakers and listeners take advantage of mutually shared knowledge (i.e., common ground). How such information is represented in memory is not well known. Using a neuropsychological-psycholinguistic approach to real-time language understanding, we investigated the ability to form and use common ground during conversation in memory-impaired participants with hippocampal amnesia. Analyses of amnesics’ eye fixations as they interpreted their partner’s utterances about a set of objects demonstrated successful use of common ground when the amnesics had immediate access to common-ground information, but dramatic failures when they did not. These findings indicate a clear role for declarative memory in maintenance of common-ground representations. Even when amnesics were successful, however, the eye movement record revealed subtle deficits in resolving potential ambiguity among competing intended referents; this finding suggests that declarative memory may be critical to more basic aspects of the on-line resolution of linguistic ambiguity.
Simulation of passenger car synchronizer ring movement during rattling
Authors: Fietkau P , Baumann A , Bertsche B
Published: November 2011

This article presents a model for the calculation of the hydrodynamic forces and vibration behaviour of a passenger car synchronizer ring during rattling, i.e. a ring which is excited by rotational speed irregularities and therefore moves within its functional clearance. The hydrodynamic forces are calculated on basis of the Reynolds equation for thin fluid films. An analytical solution and a numerical one of the Reynolds equation are presented for both dry and mixed frictions. The oil-slung-out effect in the synchronizer ring gap is also taken into account in the solution. For the simulation, a multi-body system of the gearbox inner parts and a finite element model of the gearbox housing have been developed. The simulation results show the synchronizer ring movement, oil film thickness, and oil pressure distribution at different torsional excitation levels. The influence of different oil viscosities, the maximum oil film thickness, and wear of the synchronizer ring friction lining is investigated in parameter studies. Finally, the simulation results are validated by experimental measurements on an automotive transmission rattle test bench with a single-stage gearbox. The measurement results show that the developed model is capable of representing the principal characteristics of a synchronizer ring during rattling.
A New Reliable and Valid Tool for Measuring Implicit Self-Esteem
Authors: Krause S. , Back M. D. , Egloff B. , Schmukle S. C.
Published: November 2011

We investigated the reliability and predictive validity of a new response-window affective priming task (RW-APT) for the measurement of implicit self-esteem. Participants (N = 96) were administered the self-esteem RW-APT and filled out two measures of explicit self-esteem. To investigate the effect of explicit and implicit self-esteem on reactions to failure, we applied an anagram task in which participants received anagrams that were more difficult than expected. Three self-esteem criteria were obtained: pretask expectancy bias, perceived performance bias, and posttask expectancy bias. As hypothesized, explicit self-esteem and implicit self-esteem measures independently predicted all validity criteria. Taken together, the results show that RW-APT is a reliable and valid measure that might be an important addition to established measures of self-esteem.
Pulmonary system limitations to endurance exercise performance in humans
Authors: Amann Markus
Published: November 2011

Accumulating evidence over the past 25 years depicts the healthy pulmonary system as a limiting factor of whole‐body endurance exercise performance. This brief overview emphasizes three respiratory system‐related mechanisms which impair O2 transport to the locomotor musculature [arterial O2 content (
) × leg blood flow (
)], i.e. the key determinant of an individual's aerobic capacity and ability to resist fatigue. First, the respiratory system often fails to prevent arterial desaturation substantially below resting values and thus compromises
. Especially susceptible to this threat to convective O2 transport are well‐trained endurance athletes characterized by high metabolic and ventilatory demands and, probably due to anatomical and morphological gender differences, active women. Second, fatiguing respiratory muscle work (Wresp) associated with strenuous exercise elicits sympathetically mediated vasoconstriction in limb‐muscle vasculature, which compromises
. This impact on limb O2 transport is independent of fitness level and affects all individuals, but only during sustained, high‐intensity endurance exercise performed above ∼85% maximal oxygen uptake. Third, excessive fluctuations in intrathoracic pressures accompanying Wresp can limit cardiac output and therefore
. Exposure to altitude exacerbates the respiratory system limitations observed at sea level, further reducing
and substantially increasing exercise‐induced Wresp. Taken together, the intact pulmonary system of healthy endurance athletes impairs locomotor muscle O2 transport during strenuous exercise by failing to ensure optimal arterial oxygenation and compromising
. This respiratory system‐related impact exacerbates the exercise‐induced development of fatigue and compromises endurance performance.
Measurement and simulation of myoplasmic calcium transients in mouse slow‐twitch muscle fibres
Authors: Hollingworth Stephen , Kim Michele M. , Baylor Stephen M.
Published: November 2011

Non‐technical summary  In voluntary muscle cells, the change in the intracellular concentration of calcium ions (Δ[Ca2+]) controls the contractile cycle by controlling the binding of Ca2+ to the ‘regulatory’ sites on the troponin molecules attached to the myofilaments. Δ[Ca2+] is difficult to measure under physiological conditions, as indicated by the discrepancies in results from recent studies of Δ[Ca2+] on mouse slow‐twitch muscle fibres. Here we examine some of the reasons underlying these discrepancies and argue that measurements made with membrane‐impermeant Ca2+ indicators that are micro‐injected into intact fibres are more accurate than those made with indicators introduced into enzyme‐dissociated fibres by diffusion (“AM loading”). Using a computational model, we have analysed the Δ[Ca2+] measurements to estimate the kinetic rate constants that govern the reaction of Ca2+ with the troponin regulatory sites. To our knowledge, this is the first time such estimates have been deduced from physiological measurements in living slow‐twitch muscle fibres.
Low frequency tantalum electromechanical systems for biomimetical applications
Authors: Latif Rhonira , Mastropaolo Enrico , Bunting Andrew , Cheung Rebecca , Koickal Thomas , Hamilton Alister , Newton Michael , Smith Leslie
Published: November 2011

The integration of p-channel metal-oxide-semiconductor transistors and tantalum bridge structures for the fabrication of resonant gate transistors (RGTs) that operate in the audible frequency range has been developed. Resonant gate transistors with channel length of 15 μm and clamped-clamped tantalum bridges of 0.5 mm to 1.6 mm in length have been fabricated. The measured first modal frequency of the bridges has been found to be higher than the expected theoretical value. From the experimental and theoretical analysis of the first three modes, the stress in the bridges has been extracted and found to be tensile with values of 3 MPa – 10 MPa. Finite element simulation has validated the extracted stress and the mode shapes of the tantalum bridges. The modulation of conductance in the channel region between the source and drain by the tantalum bridge of the RGT has been demonstrated. The threshold voltage and transconductance of the fabricated p-channel RGT have been measured to be −37 V and 6.84 μS, respectively.
Continuous atomic layer deposition: Explanation for anomalous growth rate effects
Authors: Maydannik Philipp S. , Kaariainen Tommi O. , Cameron David. C.
Published: November 2011

Spatial atomic layer deposition (ALD) on moving substrates has recently been the subject of increasing interest and development. Recent results of deposition on flexible substrates in a cylindrical rotating continuous ALD system showed that in certain regions of operation, deviations from ideal ALD behavior occurred showing excess deposition during the trimethylaluminium (TMA)/water process for aluminum oxide. It was speculated that this was due to boundary layer gas entrainment at the surface of the moving substrate and consequent drag-through of precursors between the different precursor vapor zones. In this paper a study has been made of these gas entrainment effects by using helium as a tracer gas to determine how the transport between zones takes place. A simple model of the process based on physical principles has been constructed which replicates the observed helium transport behavior in the boundary layer. Based on this, it has been shown that gas entrainment is not the reason for the anomalous excess growth in this system. As an alternative explanation, adsorption of excess water molecules on the substrate surface and their carry over to the TMA zone has been proposed as the cause of the anomalous growth. A physical model for this process has been constructed and it has been shown that simulations based on this model reproduce the observed behavior over a range of substrate temperatures.
HopX1 in Erwinia amylovora Functions as an Avirulence Protein in Apple and Is Regulated by HrpL
Authors: Bocsanczy A. M. , Schneider D. J. , DeClerck G. A. , Cartinhour S. , Beer S. V.
Published: November 2011

Fire blight is a devastating disease of rosaceous plants caused by the Gram-negative bacterium
Erwinia amylovora
. This pathogen delivers virulence proteins into host cells utilizing the type III secretion system (T3SS). Expression of the T3SS and of translocated and secreted substrates is activated by the alternative sigma factor HrpL, which recognizes
hrp
box promoters upstream of regulated genes. A collection of hidden Markov model (HMM) profiles was used to identify putative
hrp
boxes in the genome sequence of Ea273, a highly virulent strain of
E. amylovora
. Among potential virulence factors preceded by putative
hrp
boxes, two genes previously known as Eop3 and Eop2 were characterized. The presence of functionally active
hrp
boxes upstream of these two genes was confirmed by β-glucuronidase (GUS) assays. Deletion mutants of the latter candidate genes, renamed

hopX1
Ea

and

hopAK1
Ea

, respectively, did not differ in virulence from the wild-type strain when assayed in pear fruit and apple shoots. The

hopX1
Ea

deletion mutant of Ea273, complemented with a plasmid overexpressing

hopX1
E

a
, suppressed the development of the hypersensitivity response (HR) when inoculated into
Nicotiana benthamiana
; however, it contributed to HR in
Nicotiana tabacum
and significantly reduced the progress of disease in apple shoots, suggesting that HopX1
Ea
may act as an avirulence protein in apple shoots.
Effects of Cortex Peptidoglycan Structure and Cortex Hydrolysis on the Kinetics of Ca
2+
-Dipicolinic Acid Release during Bacillus subtilis Spore Germination
Authors: Zhang Pengfei , Thomas Stacy , Li Yong-qing , Setlow Peter
Published: November 2011

The kinetic parameters of the release of Ca
2+
-dipicolinic acid (CaDPA) during germination of spore populations and multiple individual spores of
Bacillus subtilis
strains with major alterations in the structure of the spore peptidoglycan (PG) cortex or lacking one or both of the two redundant enzymes involved in cortex hydrolysis (cortex-lytic enzymes [CLEs]) were determined. The lack of the CLE CwlJ greatly slowed CaDPA release with a germinant receptor (GR)-dependent germinant,
l
-valine, or a non-GR-dependent germinant, dodecylamine. The absence of the cortex-specific PG modification muramic acid–δ-lactam also increased the time needed for full CaDPA release during germination with both types of germinants. In contrast, increased cortex PG cross-linking was associated with faster times for initiation of CaDPA release with both
l
-valine and dodecylamine but not with faster CaDPA release once this release had been initiated. These data suggest that the precise structure of the spore cortex plays a significant role in determining the timing and the rate of CaDPA release during
B. subtilis
spore germination and, further, that this effect is independent of effects of GRs.
Biomarkers and Cardiovascular Risk Assessment for Primary Prevention: An Update
Authors: Gilstrap Lauren G , Wang Thomas J
Published: November 2011

BACKGROUND

Interest in cardiovascular biomarkers in primary prevention has increased dramatically in the past decade. This increase has been fueled by an improved understanding of cardiovascular pathophysiology, as well as novel technologies for biomarker identification.

CONTENT

In this review we provide a brief overview of recent concepts in the evaluation of screening biomarkers, because biomarkers may behave differently when used for screening as opposed to diagnosis or disease staging. The following specific biomarker examples are then discussed, with a focus on data from primary prevention studies: high-sensitivity C-reactive protein, B-type natriuretic peptide, lipoprotein-associated phospholipase A2, and high-sensitivity troponin T. The article concludes by addressing novel platforms for biomarker discovery, reviewing recent examples from the field of metabolomics.

An ongoing challenge is to develop screening strategies that can identify individuals at risk for cardiovascular events well before symptoms appear. For this purpose, the measurement of soluble biomarkers could be an important adjunct to traditional cardiovascular risk assessment. Recent studies highlight both the strengths and limitations of “novel” circulating biomarkers, and suggest that substantial work is still needed to identify biomarkers that are sufficiently accurate and cost-effective for routine use in primary prevention.
QTc Values Among Children and Adolescents Presenting to the Emergency Department
Authors: Van Dorn Charlotte S. , Johnson Jonathan N. , Taggart Nathaniel W. , Thorkelson Lois , Ackerman Michael J.
Published: November 2011

OBJECTIVE:

Long-QT syndrome (LQTS) is both underdiagnosed and overdiagnosed. Many patients are incorrectly diagnosed as having LQTS after presenting to an emergency department (ED) with presyncope/syncope and demonstrating “borderline” QT-interval prolongation (QTc ≥ 440 milliseconds) in a sentinel ED-obtained electrocardiogram (ECG). We sought to evaluate the distribution and clinical significance of QT intervals in the ED.

METHODS:

We retrospectively reviewed data for all patients 22 years of age or younger (N = 626; 369 females; age, mean ± SD: 17 ± 5 years) who had ECGs obtained in our ED between July 1, 2007, and June 30, 2008. A total of 223 patients were excluded because of known structural heart disease, arrhythmias, electrolyte abnormalities, or exposure to QT-interval–prolonging medications.

RESULTS:

The average QTc was 428 ± 28 milliseconds (range: 344–566 milliseconds), and approximately one-third of patients had QTc values of ≥440 milliseconds (females: 41%; males: 21%). Overall, 104 patients presented with presyncope/syncope, of whom 14 (13%) had follow-up ECGs. On follow-up, these patients demonstrated significant decreases in QTc values of 33 ± 43 milliseconds (P < .04). Only 8 (31%) of 26 patients with presyncope/syncope with borderline QT values had follow-up ECGs performed, in 5 of which the QTc values were decreased significantly. No patients ultimately received LQTS diagnoses.

CONCLUSIONS:

In the ED setting, approximately one-third of pediatric patients exhibited QTc values of ≥440 milliseconds and had significant normalization of QTc values in follow-up evaluations. First-time ECGs obtained after a syncopal episode must be interpreted with caution, particularly in the context of so-called borderline QT intervals.
Psychiatric and Medical Comorbidity and Quality of Life Outcomes in Childhood-Onset Epilepsy
Authors: Baca Christine B. , Vickrey Barbara G. , Caplan Rochelle , Vassar Stefanie D. , Berg Anne T.
Published: November 2011

OBJECTIVE:

We compared associations of epilepsy remission status and severity as well as psychiatric and other comorbidities with child and parent-proxy reports of health-related quality of life (HRQoL) in adolescents previously diagnosed with epilepsy.

METHODS:

In a prospective, community-based study of newly diagnosed childhood epilepsy, HRQoL of 277 children was assessed 8 to 9 years after diagnosis by using child and parent-proxy versions of the Child Health Questionnaire (CHQ). Multiple linear regression models adjusted for age and gender were used to compare associations of epilepsy remission and “complicated” epilepsy (secondary to an underlying neurologic insult or epileptic encephalopathy) status and psychiatric and other comorbidities with HRQoL.

RESULTS:

Mean age of epilepsy onset was 4.4 years (SD: 2.6). At the 9-year reassessment, children were, on average, 13.0 years old (SD: 2.6); 64% were seizure-free for 5 years, 31% were taking antiepileptic drugs, and 19% had a complicated epilepsy. Prevalence of comorbidities at follow-up were 26% psychiatric diagnosis; 39% neurodevelopmental spectrum disorder (NDSD); 24% chronic medical illness; and 15% migraine. In multivariable analysis, having a psychiatric disorder was broadly associated with child (6 of 11 scales) and parent-proxy (7 of 12 scales) HRQoL (P ≤ .0125). Five-year remission and complicated epilepsy status had few or no associations with HRQoL. Although parent-proxy HRQoL was strongly associated with NDSD (6 of 11 scales), child-reported HRQoL was not (2 of 11 scales).

CONCLUSIONS:

Psychiatric comorbidities are strongly associated with long-term HRQoL in childhood-onset epilepsy, which suggests that comprehensive epilepsy care must include screening and treatment for these conditions, even if seizures remit.
Sirtuin 1–Mediated Cellular Metabolic Memory of High Glucose Via the LKB1/AMPK/ROS Pathway and Therapeutic Effects of Metformin
Authors: Zheng Zhi , Chen Haibing , Li Jun , Li Tao , Zheng Bingqing , Zheng Ying , Jin Huiyi , He Ying , Gu Qing , Xu Xun
Published: November 2011

Cellular metabolic memory occurs in diabetic microvascular and macrovascular complications, but the underlying mechanisms remain unclear. Here, we investigate the role of sirtuin 1 (SIRT1) and metformin in this phenomenon. In bovine retinal capillary endothelial cells (BRECs) and retinas of diabetic rats, the inflammatory gene, nuclear factor-κB (NF-κB), and the proapoptotic gene, Bax, induced by hyperglycemia, remained elevated after returning to normoglycemia. BRECs with small interfering RNA–mediated SIRT1 knockdown had increased sensitivity to hyperglycemia stress, whereas SIRT1 overexpression or activation by metformin inhibited the increase of mitochondrial reactive oxygen species–mediated glyceraldehyde-3-phosphate dehydrogenase by poly (ADP-ribose) polymerase (PARP) activity through the upregulation of liver kinase B1/AMP-activated protein kinase (LKB1/AMPK), ultimately suppressing NF-κB and Bax expression. Furthermore, we showed that hyperglycemia led to PARP activation, which in turn may have downregulated SIRT1. Of importance, this study also demonstrated that metformin suppressed the “memory” of hyperglycemia stress in the diabetic retinas, which may be involved in the SIRT1/LKB1/AMPK pathway. Our data suggest that SIRT1 is a potential therapeutic target for the treatment of the cellular metabolic memory, and the use of metformin specifically for such therapy may be a new avenue of investigation in the diabetes field.