bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex Immune Cell Interplay in the Gamma Interferon Response during Toxoplasma gondii Infection
Authors: Sturge Carolyn R. , Yarovinsky Felix
Published: May 2014

Toxoplasma gondiiis an obligate intracellular parasite of clinical importance, especially in immunocompromised patients. Investigations into the immune response to the parasite found that T cells are the primary effector cells regulating gamma interferon (IFN-γ)-mediated host resistance. However, recent studies have revealed a critical role for the innate immune system in mediating host defense independently of the T cell responses to the parasite. This body of knowledge is put into perspective by the unifying theme that immunity to the protozoan parasite requires a strong IFN-γ host response. In the following review, we discuss the role of IFN-γ-producing cells and the signals that regulate IFN-γ production duringT. gondiiinfection.
Plasmid CDS5 Influences Infectivity and Virulence in a Mouse Model of Chlamydia trachomatis Urogenital Infection
Authors: Ramsey K. H. , Schripsema J. H. , Smith B. J. , Wang Y. , Jham B. C. , O'Hagan K. P. , Thomson N. R. , Murthy A. K. , Skilton R. J. , Chu P. , Clarke I. N.
Published: May 2014

The native plasmid of both
Chlamydia muridarum
and
Chlamydia trachomatis
has been shown to control virulence and infectivity in mice and in lower primates. We recently described the development of a plasmid-based genetic transformation protocol for
Chlamydia trachomatis
that for the first time provides a platform for the molecular dissection of the function of the chlamydial plasmid and its individual genes or coding sequences (CDS). In the present study, we transformed a plasmid-free lymphogranuloma venereum isolate of
C. trachomatis
, serovar L2, with either the original shuttle vector (pGFP::SW2) or a derivative of pGFP::SW2 carrying a deletion of the plasmid CDS5 gene (pCDS5KO). Female mice were inoculated with these strains either intravaginally or transcervically. We found that transformation of the plasmid-free isolate with the intact pGFP::SW2 vector significantly enhanced infectivity and induction of host inflammatory responses compared to the plasmid-free parental isolate. Transformation with pCDS5KO resulted in infection courses and inflammatory responses not significantly different from those observed in mice infected with the plasmid-free isolate. These results indicate a critical role of plasmid CDS5 in
in vivo
fitness and in induction of inflammatory responses. To our knowledge, these are the first
in vivo
observations ascribing infectivity and virulence to a specific plasmid gene.
IraL Is an RssB Anti-adaptor That Stabilizes RpoS during Logarithmic Phase Growth in Escherichia coli and
Shigella
Authors: Hryckowian Andrew J. , Battesti Aurelia , Lemke Justin J. , Meyer Zachary C. , Welch Rodney A.
Published: May 2014

RpoS (σ
S
), the general stress response sigma factor, directs the expression of genes under a variety of stressful conditions. Control of the cellular σ
S
concentration is critical for appropriately scaled σ
S
-dependent gene expression. One way to maintain appropriate levels of σ
S
is to regulate its stability. Indeed, σ
S
degradation is catalyzed by the ClpXP protease and the recognition of σ
S
by ClpXP depends on the adaptor protein RssB. Three anti-adaptors (IraD, IraM, and IraP) exist in
Escherichia coli
K-12; each interacts with RssB and
i
nhibits
R
ssB
a
ctivity under different stress conditions, thereby stabilizing σ
S
. Unlike K-12, some
E. coli
isolates, including uropathogenic
E. coli
strain CFT073, show comparable cellular levels of σ
S
during the logarithmic and stationary growth phases, suggesting that there are differences in the regulation of σ
S
levels among
E. coli
strains. Here, we describe IraL, an RssB anti-adaptor that stabilizes σ
S
during logarithmic phase growth in CFT073 and other
E. coli
and
Shigella
strains. By immunoblot analyses, we show that IraL affects the levels and stability of σ
S
during logarithmic phase growth. By computational and PCR-based analyses, we reveal that
iraL
is found in many
E. coli
pathotypes but not in laboratory-adapted strains. Finally, by bacterial two-hybrid and copurification analyses, we demonstrate that IraL interacts with RssB by a mechanism distinct from that used by other characterized anti-adaptors. We introduce a fourth RssB anti-adaptor found in
E. coli
species and suggest that differences in the regulation of σ
S
levels may contribute to host and niche specificity in pathogenic and nonpathogenic
E. coli
strains.

IMPORTANCE
Bacteria must cope with a variety of environmental conditions in order to survive. RpoS (σ
S
), the general stress response sigma factor, directs the expression of many genes under stressful conditions in both pathogenic and nonpathogenic
Escherichia coli
strains. The regulation of σ
S
levels and activity allows appropriately scaled σ
S
-dependent gene expression. Here, we describe IraL, an RssB anti-adaptor that, unlike previously described anti-adaptors, stabilizes σ
S
during the logarithmic growth phase in the absence of additional stress. We also demonstrate that
iraL
is found in a large number of
E. coli
and
Shigella
isolates. These data suggest that strains containing
iraL
are able to initiate σ
S
-dependent gene expression under conditions under which strains without
iraL
cannot. Therefore, IraL-mediated σ
S
stabilization may contribute to host and niche specificity in
E. coli
.
Spatial-Temporal Survey and Occupancy-Abundance Modeling To Predict Bacterial Community Dynamics in the Drinking Water Microbiome
Authors: Pinto Ameet J. , Schroeder Joanna , Lunn Mary , Sloan William , Raskin Lutgarde
Published: May 2014

Bacterial communities migrate continuously from the drinking water treatment plant through the drinking water distribution system and into our built environment. Understanding bacterial dynamics in the distribution system is critical to ensuring that safe drinking water is being supplied to customers. We present a 15-month survey of bacterial community dynamics in the drinking water system of Ann Arbor, MI. By sampling the water leaving the treatment plant and at nine points in the distribution system, we show that the bacterial community spatial dynamics of distance decay and dispersivity conform to the layout of the drinking water distribution system. However, the patterns in spatial dynamics were weaker than those for the temporal trends, which exhibited seasonal cycling correlating with temperature and source water use patterns and also demonstrated reproducibility on an annual time scale. The temporal trends were driven by two seasonal bacterial clusters consisting of multiple taxa with different networks of association within the larger drinking water bacterial community. Finally, we show that the Ann Arbor data set robustly conforms to previously described interspecific occupancy abundance models that link the relative abundance of a taxon to the frequency of its detection. Relying on these insights, we propose a predictive framework for microbial management in drinking water systems. Further, we recommend that long-term microbial observatories that collect high-resolution, spatially distributed, multiyear time series of community composition and environmental variables be established to enable the development and testing of the predictive framework.

IMPORTANCE
Safe and regulation-compliant drinking water may contain up to millions of microorganisms per liter, representing phylogenetically diverse groups of bacteria, archaea, and eukarya that affect public health, water infrastructure, and the aesthetic quality of water. The ability to predict the dynamics of the drinking water microbiome will ensure that microbial contamination risks can be better managed. Through a spatial-temporal survey of drinking water bacterial communities, we present novel insights into their spatial and temporal community dynamics and recommend steps to link these insights in a predictive framework for microbial management of drinking water systems. Such a predictive framework will not only help to eliminate microbial risks but also help to modify existing water quality monitoring efforts and make them more resource efficient. Further, a predictive framework for microbial management will be critical if we are to fully anticipate the risks and benefits of the beneficial manipulation of the drinking water microbiome.
Jejunal intussusception: a rare cause of an acute abdomen in adults
Authors: Patel Sonali , Eagles Natasha , Thomas Peter
Published: May 2014

Abdominal pain secondary to intussusception is a common presentation in the paediatric population but rare in adults. Diagnosis is often difficult due to non-specific signs and symptoms. Adult intussusception presents more insidiously with intermittent abdominal pain and signs and symptoms of an acute abdomen are rare. In children, the aetiological factor is usually idiopathic, whereas intussusception in adults is more commonly due to an underlying pathology giving rise to a lead point. Consequently the treatment of choice is different—while it is supportive in children, surgical management is typically indicated in adults. In addition, the causes of a lead point precipitating adult intussusception are different depending on whether they arise from the small or large bowel. This report presents a case of jejunal intussusception in a 30-year-old man with a characteristic CT scan who required exploratory laparotomy and small bowel resection.
Acrocyanosis in a young adult: a rare presentation of extra-adrenal pheochromocytoma
Authors: Kumar Prabhat , Ghosh Soumik , Tanwar Hitendra Singh , Gupta Ashish Kumar
Published: May 2014

Extra-adrenal pheochromocytomas (EAPs) are rare catecholamine-secreting tumours. The patient commonly present with headache, palpitation, anxiety, diaphoresis, raised blood pressure and heart rate which can be sustained or episodic and less commonly Raynaud's phenomenon. We present a case of an adult woman who presented with unilateral upper limb acrocyanosis and hypertension which was secondary to EAP and resolved completely after surgical removal of the tumour.
Recycling of jejunal effluent to enable enteral nutrition in short bowel syndrome
Authors: McCain Stephen , McCain Scott , Harris Andrew , McCallion Kevin
Published: May 2014

A 41-year-old woman developed severe abdominal pain, distension and faeculent vomiting. CT of abdomen and pelvis revealed small bowel malrotation with a right paraduodenal hernia. At emergency laparotomy, a right paraduodenal hernia containing jejunum and ileum was identified. She had a viable duodenum with 50 cm of ischaemic proximal jejunum which was exteriorised as an end jejunostomy; 180 cm of infarcted jejunum and ileum was resected. The proximal end of 150 cm of healthy ileum was exteriorised as a closed mucous fistula and 50 cm distally a feeding ileostomy was constructed. On day 5 postoperatively, jejunal effluent began to be recycled via her feeding ileostomy and she never required parenteral nutrition. Despite having only 50 cm of jejunum proximal to her stoma, recycling of effluent enabled her electrolytes to remain normal. She put on weight postoperatively and proceeded to closure of her stomas at 6 months, not requiring laparotomy.
Ovarian carcinoid presenting with right heart failure
Authors: Damen Nikki
Published: May 2014

A 69-year-old woman presented with a pelvic mass as well as a 6-month history of progressive bilateral peripheral oedema with more recent breathlessness and abdominal distension. She was found to have significant right heart failure (RHF) which was extensively investigated. No significant lung disease or pulmonary embolism was identified to explain the findings. Severe tricuspid incompetence was thus thought to be secondary to the systemic effects of a carcinoid tumour, confirmed to be ovarian in origin (on positron emission tomography/CT scan and histopathology). Prior to major pelvic surgery for removal of the ovarian mass, she underwent tricuspid and pulmonary valve replacement surgery due to the deteriorating right heart function. She had an uneventful recovery after both operations and continues to be followed up closely with serial ovarian and carcinoid tumour markers.
Macroscopic conductivity of free fermions in disordered media
Authors: Bru J.-B. , de Siqueira Pedra W. , Hertling C.
Published: May 2014

We conclude our analysis of the linear response of charge transport in lattice systems of free fermions subjected to a random potential by deriving general mathematical properties of its conductivity at the macroscopic scale. The present paper belongs to a succession of studies on Ohm and Joule's laws from a thermodynamic viewpoint starting with [1-3]. We show, in particular, the existence and finiteness of the conductivity measure μΣ for macroscopic scales. Then we prove that, similar to the conductivity measure associated to Drude's model, μΣ converges in the weak*-topology to the trivial measure in the case of perfect insulators (strong disorder, complete localization), whereas in the limit of perfect conductors (absence of disorder) it converges to an atomic measure concentrated at frequency ν = 0. However, the AC-conductivity μΣ|ℝ\{0} does not vanish in general: We show that μΣ(ℝ\{0}) > 0, at least for large temperatures and a certain regime of small disorder.
The Borexino purification system
Authors: Benziger Jay
Published: May 2014

Purification of 278 tons of liquid scintillator and 889 tons of buffer shielding for the Borexino solar neutrino detector is performed with a system of combined distillation, water extraction, gas stripping and filtration. The purification system removed K , U and Th by distillation of the pseudocumene solvent and the PPO fluor. Noble gases, Rn , Kr and Ar were removed by gas stripping. Distillation was also employed to remove optical impurities and reduce the attenuation of scintillation light. The success of the purification system has facilitated the first time real time detection of low energy solar neutrinos.
D-brane on Poisson manifold and generalized geometry
Authors: Asakawa Tsuguhiko , Muraki Hisayoshi , Watamura Satoshi
Published: May 2014

The properties of the D-brane fluctuations are investigated using the two types of deformation of the Dirac structure, based on the B-transformation and the β-transformation, respectively. The former gives the standard gauge theory with two-form field strength. The latter gives a nonstandard gauge theory on the Poisson manifold with bivector field strength and the vector field as a gauge potential, where the gauge symmetry is a diffeomorphism generated by the Hamiltonian vector field. The map between the two gauge theories is also constructed with the help of Moser's Lemma and the Magnus expansion. We also investigate the relation to the gauge theory on the noncommutative D-branes.
Dynamics of Memristor Circuits
Authors: Itoh Makoto , Chua Leon O.
Published: May 2014

In this paper, we show that Hamilton's equations can be recast into the equations of dissipative memristor circuits. In these memristor circuits, the Hamiltonians can be obtained from the principles of conservation of "charge" and "flux", or the principles of conservation of "energy". Furthermore, the dynamics of memristor circuits can be recast into the dynamics of "ideal memristor" circuits. We also show that nonlinear capacitors are transformed into nonideal memristors if an exponential coordinate transformation is applied. Furthermore, we show that the zero-crossing phenomenon does not occur in some memristor circuits because the trajectories do not intersect the i = 0 axis. We next show that nonlinear circuits can be realized with fewer elements if we use memristors. For example, Van der Pol oscillator can be realized by only two elements: an inductor and a memristor. Chua's circuit can be realized by only three elements: an inductor, a capacitor, and a voltage-controlled memristor. Finally, we show an example of two-cell memristor CNNs. In this system, the neuron's activity depends partly on the supplied currents of the memristors.
Bifurcation Analysis of an SIV Epidemic Model with the Saturated Incidence Rate
Authors: Xue Yakui , Tang Xiaoming , Yuan Xinpeng
Published: May 2014

In this paper, an SIV epidemic model with the saturated incidence rate is investigated, considering the factors of population dynamics such as the constant recruitment of population, the natural morality and vaccination strategy. By carrying out the bifurcation analysis of the model, it is shown that numerous kinds of bifurcation occur for the model, such as Hopf bifurcation and Bogdanov–Takens bifurcation. The main results are illustrated by numerical simulations.
Chaotic Dynamics of an Axially Accelerating Viscoelastic Beam in the Supercritical Regime
Authors: Ding Hu , Yan Qiao-Yun , Zu Jean W.
Published: May 2014

This paper focuses on the bifurcation and chaos of an axially accelerating viscoelastic beam in the supercritical regime. For the first time, the nonlinear dynamics of the system under consideration are studied via the high-order Galerkin truncation as well as the differential and integral quadrature method (DQM & IQM). The speed of the axially moving beam is assumed to be comprised of a constant mean value along with harmonic fluctuations. The transverse vibrations of the beam are governed by a nonlinear integro-partial-differential equation, which includes the finite axial support rigidity and the longitudinally varying tension due to the axial acceleration. The Galerkin truncation and the DQM & IQM are, respectively, applied to reduce the equation into a set of ordinary differential equations. Furthermore, the time history of the axially moving beam is numerically solved based on the fourth-order Runge–Kutta time discretization. Based on the numerical solutions, the phase portrait, the bifurcation diagrams and the initial value sensitivity are presented to identify the dynamical behaviors. Based on the nonlinear dynamics, the effects of the truncation terms of the Galerkin method, such as 2-term, 4-term, and 6-term, are studied by comparison with DQM & IQM.
Multipulse Chaotic Dynamics for Nonautonomous Nonlinear Systems and Application to a FGM Plate
Authors: Zhang Junhua , Zhang Wei , Hao Yuxin
Published: May 2014

The extended Melnikov method is improved to investigate the nonautonomous nonlinear dynamical system in Cartesian coordinate. The multipulse chaotic dynamics of a simply supported functionally graded materials (FGM) rectangular plate subjected to transversal and in-plane excitations is investigated in this paper for the first time. The formulas of the FGM rectangular plate are two-degree-of-freedom nonautonomous nonlinear system with coupling of nonlinear terms including several square and cubic terms. The extended Melnikov method is improved to enable us to analyze directly the nonautonomous nonlinear dynamical system of the simply-supported FGM rectangular plate. The results obtained here indicate that multipulse chaotic motions can occur in the simply-supported FGM rectangular plate. Numerical simulation is also employed to find the multipulse chaotic motions of the simply-supported FGM rectangular plate.
The Combined Effect of Dynamic Chemical and Electrical Synapses in Time-Delay-Induced Phase-Transition to Synchrony in Coupled Bursting Neurons
Authors: Megam Ngouonkadi E. B. , Fotsin Hilaire B. , Louodop Fotso P. H.
Published: May 2014

In this paper, we study the combined effect of dynamic chemical and electrical synapses in time-delay-induced phase-transition to synchrony in coupled bursting neurons. Time-delay in coupled nonlinear oscillators or in a network of coupled nonlinear oscillators has been found to be responsible for striking dynamical behaviors such as phase-flip-transitions. These phenomena lead to synchrony or out of synchrony in different oscillators of the system. Here, we show that synaptic parameters, more precisely the neurotransmitters binding time constant influences the phase-flip-transitions of the system. We discuss how the system goes to the phase-flip-transitions when both electrical and dynamic chemical synapses are taken into account. The fourth-order Hindmarsh–Rose neuronal oscillator is considered here for the study of these transitions. A discussion on the importance of these results in brain researches is given, particularly to understand the collective dynamics of bursting neurons.
Constructing a Novel No-Equilibrium Chaotic System
Authors: Pham Viet-Thanh , Volos Christos , Jafari Sajad , Wei Zhouchao , Wang Xiong
Published: May 2014

This paper introduces a new no-equilibrium chaotic system that is constructed by adding a tiny perturbation to a simple chaotic flow having a line equilibrium. The dynamics of the proposed system are investigated through Lyapunov exponents, bifurcation diagram, Poincaré map and period-doubling route to chaos. A circuit realization is also represented. Moreover, two other new chaotic systems without equilibria are also proposed by applying the presented methodology.
Representation of Medical Guidelines with a Computer Interpretable Model
Authors: Simalatsar Alena , You Wenqi , Gotta Verena , Widmer Nicolas , De Micheli Giovanni
Published: May 2014

Nowadays medical software is tightly coupled with medical devices that perform patient state monitoring and lately even some basic treatment procedures. Medical guidelines (GLs) can be seen as specification of a medical system which requires their computer-interpretable representation of medical GLs. Until now most of the medical GLs are often represented in a textual format and therefore often suffer from such structural problems as incompleteness, inconsistencies, ambiguity and redundancy, which makes the translation process to the machine-interpretable language more complicated. Computer-based interpretation of GLs can improve the quality of protocols as well as the quality of medical service. Several GLs formal representation methods have been presented recently. Only some of them enable automatic formal verification by introducing an additional translation path to the existing model checking environments. However, if a verified property fails it is difficult to trace back the result needed to change the model. Moreover, these formalisms provide the notion of time mostly in terms of actions order. In this paper we preset the application of a well-know formal behaviour representation approach of embedded systems design domain to medical GLs interpretation. We use Timed Automata extended with Tasks (TAT) and TIMES toolbox to represent medical GLs as a system behaviour in a computer interpretable form. We discuss the verification issues with the help of the anticancer drug imatinib case study.
Kernel Sparse Models for Automated Tumor Segmentation
Authors: Thiagarajan Jayaraman J. , Ramamurthy Karthikeyan Natesan , Rajan Deepta , Spanias Andreas , Puri Anup , Frakes David
Published: May 2014

In this paper, we propose sparse coding-based approaches for segmentation of tumor regions from magnetic resonance (MR) images. Sparse coding with data-adapted dictionaries has been successfully employed in several image recovery and vision problems. The proposed approaches obtain sparse codes for each pixel in brain MR images considering their intensity values and location information. Since it is trivial to obtain pixel-wise sparse codes, and combining multiple features in the sparse coding setup is not straight-forward, we propose to perform sparse coding in a high-dimensional feature space where non-linear similarities can be effectively modeled. We use the training data from expert-segmented images to obtain kernel dictionaries with the kernel K-lines clustering procedure. For a test image, sparse codes are computed with these kernel dictionaries, and they are used to identify the tumor regions. This approach is completely automated, and does not require user intervention to initialize the tumor regions in a test image. Furthermore, a low complexity segmentation approach based on kernel sparse codes, which allows the user to initialize the tumor region, is also presented. Results obtained with both the proposed approaches are validated against manual segmentation by an expert radiologist, and it is shown that proposed methods lead to accurate tumor identification.
Francium trapping at the INFN-LNL facility
Authors: Mariotti E. , Khanbekyan A. , Marinelli C. , Marmugi L. , Moi L. , Corradi L. , Dainelli A. , Calabrese R. , Mazzocca G. , Tomassetti L.
Published: May 2014

A brief review of the Francium trapping experiments at the INFN-LNL facility is presented in the wide context of Atomic Parity-Nonconservation (APNC), which, as long as acquiring more precise and new spectroscopic data on the Francium isotopes, is the ultimate goal of the experiment. Due to its instability, Francium atoms must be produced continuously by a nuclear fusion–evaporation reaction into a heated Gold target hit by a beam of accelerated oxygen ions. Francium is then extracted in the ionic form and guided by an electrostatic line to the actual science chamber, where the ions are neutralized. Atoms are then cooled down and trapped in a Magneto-Optical Trap (MOT) to ensure both the availability of a sufficiently populated and stable atomic sample and to eliminate the Doppler broadening which would affect the precision of the measurements. A review of the recent improvements to the experimental apparatus and to the detection techniques that led to a sensitivity better than five atoms is presented. The final part of this paper deals with a summary of the recent results obtained by our collaboration and a short outlook for the immediate future.
Surface Wave-Based Health Monitoring Method for a Sheet Pile Quay Wall
Authors: Ichii Koji , Kitade Keisuke , Kawano Mayumi , Taguchi Ikuo
Published: May 2014

Port structures such as pile supported piers and quay walls generally face severe conditions, and deterioration of port structures is often observed. For an example, at a sheet pile quay wall, sheet pile is a structural component which is easily deteriorated by corrosion. As a result of deterioration of sheet pile, the backfilled soil would be washed out due to the tidal action. Suffusion, the phenomena of the washed out of fine particles and loosening of soil layer, is a problem to be considered in the maintenance of a quay wall. Therefore, a health monitoring method for the backfill of a sheet pile quay wall is necessary. In this study, the applicability of a surface-wave method for health monitoring of a sheet pile quay wall was examined. First, the variation of shear wave velocity in the ground due to suffusion and variation in water content is measured from bender element tests. Then, 2D finite element method (FEM) dynamic analysis was conducted to simulate a surface-wave measurement on a sheet pile quay wall. From the result of the analysis, the estimated shear wave velocity profile based on surface-wave method agrees fairly well with the assumed soil profile. Finally, surface-waves were measured at a sheet pile quay wall, and the measured results were compared with the result of Swedish weight sounding test at the site. Furthermore, the difference between the shear wave velocity profiles at ebb tide and that at high tide was successfully measured by the surface-wave method. Thus, the applicability of the surface-wave method for a sheet pile quay wall is demonstrated in this study.
Tests on Cracked Steel Plates with Different Damage Levels Strengthened by CFRP Laminates
Authors: Yu Qian-Qian , Zhao Xiao-Ling , Al-Mahaidi Riadh , Xiao Zhi-Gang , Chen Tao , Gu Xiang-Lin
Published: May 2014

Strengthening steel structures using carbon fiber reinforced polymer (CFRP) materials has attracted much attention in recent years owing to their potential for fatigue crack repair and their convenience in construction. However, little is known about the efficiency of this strengthening method when applied to steel plates at different crack propagation stages. An experimental study was carried out on notched steel plates strengthened using CFRP laminates. 20 specimens were tested to evaluate the fatigue performance of the strengthened steel plates with emphasis on various degrees of initial damage, simulated by different lengths of slots, including 2%, 10%, 20%, 30% and 40% of the plate width. The effects of the retrofitted configuration and CFRP stiffness were also investigated. The "beach marking" technique and crack propagation gauges were adopted to monitor the fatigue crack propagation. The experimental results were very encouraging, demonstrating that the CFRP patches could effectively slow crack growth and extend fatigue life, regardless of the initial damage levels. More effective strengthening was found by using ultra-high modulus CFRP laminates, covering the initial cracks with CFRP and repairing at an earlier stage (i.e. smaller damage level).
STRUCTURAL INTEGRITY OF SINGLE BIS(PHTHALOCYANINATO)-NEODYMIUM(III) MOLECULES ON METAL SURFACES WITH DIFFERENT REACTIVITY
Authors: FAHRENDORF SARAH , MATTHES FRANK , BÜRGLER DANIEL E. , SCHNEIDER CLAUS M. , ATODIRESEI NICOLAE , CACIUC VASILE , BLÜGEL STEFAN , BESSON CLAIRE , KÖGERLER PAUL
Published: May 2014

Magnetic molecules are auspicious candidates to act as functional units in molecular spintronics. Integrating molecules into a device environment providing mechanical support and electrical contacts requires their deposition as intact entities onto substrates. Thermal sublimation is a very clean deposition process that, however, thermally decomposes molecules of insufficient stability leading to the deposition of molecular fragments. Here, we show that the molecule-surface interaction of chemisorbed molecules affects the intramolecular bonding and can lead depending on the surface reactivity to either molecular decomposition or enhanced stability. We study the integrity of single bis(phthalocyaninato)-neodymium(III) molecules ( NdPc 2) deposited by sublimation on differently reactive surfaces, namely Au (111), Cu (100), and two atomic layers of Fe on W (110), on the single molecular level by scanning tunneling microscopy (STM) and spectroscopy. We find a strongly substrate-dependent tendency of the NdPc 2 molecules to decompose into two Pc molecules. Surprisingly, the most reactive Fe / W (110) surface shows the lowest molecular decomposition probability, whereas there are no intact NdPc 2 molecules at all on the least reactive Au (111) surface. We attribute these findings to substrate-dependent partial charge transfer from the substrate to the Pc ligands of the molecule, which strengthens the intramolecular bonding mediated predominantly by electrostatic interaction.
Hepatic glucose uptake and disposition during short-term high-fat vs. high-fructose feeding
Authors: Coate Katie C. , Kraft Guillaume , Moore Mary Courtney , Smith Marta S. , Ramnanan Christopher , Irimia Jose M. , Roach Peter J. , Farmer Ben , Neal Doss W. , Williams Phil , Cherrington Alan D.
Published: May 2014

In dogs consuming a high-fat and -fructose diet (52 and 17% of total energy, respectively) for 4 wk, hepatic glucose uptake (HGU) in response to hyperinsulinemia, hyperglycemia, and portal glucose delivery is markedly blunted with reduction in glucokinase (GK) protein and glycogen synthase (GS) activity. The present study compared the impact of selective increases in dietary fat and fructose on liver glucose metabolism. Dogs consumed weight-maintaining chow (CTR) or hypercaloric high-fat (HFA) or high-fructose (HFR) diets diet for 4 wk before undergoing clamp studies with infusion of somatostatin and intraportal insulin (3–4 times basal) and glucagon (basal). The hepatic glucose load (HGL) was doubled during the clamp using peripheral vein (Pe) glucose infusion in the first 90 min (P1) and portal vein (4 mg·kg−1·min−1) plus Pe glucose infusion during the final 90 min (P2). During P2, HGU was 2.8 ± 0.2, 1.0 ± 0.2, and 0.8 ± 0.2 mg·kg−1·min−1in CTR, HFA, and HFR, respectively ( P < 0.05 for HFA and HFR vs. CTR). Compared with CTR, hepatic GK protein and catalytic activity were reduced ( P < 0.05) 35 and 56%, respectively, in HFA, and 53 and 74%, respectively, in HFR. Liver glycogen concentrations were 20 and 38% lower in HFA and HFR than CTR ( P < 0.05). Hepatic Akt phosphorylation was decreased ( P < 0.05) in HFA (21%) but not HFR. Thus, HFR impaired hepatic GK and glycogen more than HFA, whereas HFA reduced insulin signaling more than HFR. HFA and HFR effects were not additive, suggesting that they act via the same mechanism or their effects converge at a saturable step.
Mechanisms for the adverse effects of late gestational increases in maternal cortisol on the heart revealed by transcriptomic analyses of the fetal septum
Authors: Richards Elaine M. , Wood Charles E. , Rabaglino Maria Belen , Antolic Andrew , Keller-Wood Maureen
Published: May 2014

We have previously shown in sheep that 10 days of modest chronic increase in maternal cortisol resulting from maternal infusion of cortisol (1 mg/kg/day) caused fetal heart enlargement and Purkinje cell apoptosis. In subsequent studies we extended the cortisol infusion to term, finding a dramatic incidence of stillbirth in the pregnancies with chronically increased cortisol. To investigate effects of maternal cortisol on the heart, we performed transcriptomic analyses on the septa using ovine microarrays and Webgestalt and Cytoscape programs for pathway inference. Analyses of the transcriptomic effects of maternal cortisol infusion for 10 days (130 day cortisol vs 130 day control), or ∼25 days (140 day cortisol vs 140 day control) and of normal maturation (140 day control vs 130 day control) were performed. Gene ontology terms related to immune function and cytokine actions were significantly overrepresented as genes altered by both cortisol and maturation in the septa. After 10 days of cortisol, growth factor and muscle cell apoptosis pathways were significantly overrepresented, consistent with our previous histologic findings. In the term fetuses (∼25 days of cortisol) nutrient pathways were significantly overrepresented, consistent with altered metabolism and reduced mitochondria. Analysis of mitochondrial number by mitochondrial DNA expression confirmed a significant decrease in mitochondria. The metabolic pathways modeled as altered by cortisol treatment to term were different from those modeled during maturation of the heart to term, and thus changes in gene expression in these metabolic pathways may be indicative of the fetal heart pathophysiologies seen in pregnancies complicated by stillbirth, including gestational diabetes, Cushing's disease and chronic stress.
Improving the Osteoblast Cell Adhesion on Electron Beam Controlled TiO2 Nanotubes
Authors: Yoon Sung Wook , Shim Hyun Ju , Shim In-Bo
Published: May 2014

Here we investigate the osteogenesis and synostosis processes on the surface‐modified TiO2 nanotubes via electron beam irradiation. The TiO2 nanotubes studied were synthesized by anodization process under different anodizing voltage. For the anodization voltage of 15, 20, and 25 V, TiO2 nanotubes with diameters of 59, 82, and 105 nm and length of 115, 276, and 310 nm were obtained, respectively. MC3T3‐E1 osteoblast cell line was incubated on the TiO2 nanotubes to monitor the change in the cell adhesion before and after the electron beam irradiation. We observe that the electron beam irradiation affects the number of surviving osteoblast cells as well as the cultivation time. In particular, the high adhesion rate of 155% was obtained when the osteoblast cells were cultivated for 2 hours on the TiO2 nanotube, anodized under 20 V, and irradiated with 5,000 kGy of electron beam.
Studies on the Identification of Constituents in Ethanol Extract of Radix Glycyrrhizae and Their Anti-Primary Hepatoma Cell Susceptibility
Authors: Liu Jie
Published: May 2014

The objective of this paper is to study the chemical constituents of Radix Glycyrrhizae and to apply the resulting natural products in the study of drug susceptibility of hepatoma cells so as to provide a scientific basis for quality standards and clinical application of medicinal Radix Glycyrrhizae. Chromatographic materials were used for isolation and purification; structural identification was performed based on physicochemical properties and spectral data. MTT colorimetry was used to detect the proliferation inhibition rate against primary hepatoma cells by natural products, and flow cytometry was used to detect the changes in cell cycle progression. Five compounds were isolated and identified, namely, liquiritigenin (1), liquiritin (2), isoliquiritigenin (3), betulinic acid (4), and oleanolic acid (5). In the study, 5-FU (5-fluorouracil) is used as a positive control to the hepatoma cells. Primary hepatoma cells were highly susceptible to 5-FU and liquiritigenin, both of which markedly inhibited the proliferation of hepatoma cells; flow cytometry results showed an increase in G0/G1 phase cells, a decrease in S phase cells, and a relative increase in G2/M phase cells. Primary hepatoma cells are highly susceptible to liquiritigenin, a natural product; the testing of tumor cell susceptibility is of important significance to the improvement of therapeutic effect of cancer.
Design of Heat Exchanger for Ericsson-Brayton Piston Engine
Authors: Durcansky Peter , Papucik Stefan , Jandacka Jozef , Holubcik Michal , Nosek Radovan
Published: May 2014

Combined power generation or cogeneration is a highly effective technology that produces heat and electricity in one device more efficiently than separate production. Overall effectiveness is growing by use of combined technologies of energy extraction, taking heat from flue gases and coolants of machines. Another problem is the dependence of such devices on fossil fuels as fuel. For the combustion turbine is mostly used as fuel natural gas, kerosene and as fuel for heating power plants is mostly used coal. It is therefore necessary to seek for compensation today, which confirms the assumption in the future. At first glance, the obvious efforts are to restrict the use of largely oil and change the type of energy used in transport. Another significant change is the increase in renewable energy—energy that is produced from renewable sources. Among machines gaining energy by unconventional way belong mainly the steam engine, Stirling engine, and Ericsson engine. In these machines, the energy is obtained by external combustion and engine performs work in a medium that receives and transmits energy from combustion or flue gases indirectly. The paper deals with the principle of hot-air engines, and their use in combined heat and electricity production from biomass and with heat exchangers as primary energy transforming element.
Cuckoo Search with Lévy Flights for Weighted Bayesian Energy Functional Optimization in Global-Support Curve Data Fitting
Authors: Gálvez Akemi , Iglesias Andrés , Cabellos Luis
Published: May 2014

The problem of data fitting is very important in many theoretical and applied fields. In this paper, we consider the problem of optimizing a weighted Bayesian energy functional for data fitting by using global-support approximating curves. By global-support curves we mean curves expressed as a linear combination of basis functions whose support is the whole domain of the problem, as opposed to other common approaches in CAD/CAM and computer graphics driven by piecewise functions (such as B-splines and NURBS) that provide local control of the shape of the curve. Our method applies a powerful nature-inspired metaheuristic algorithm calledcuckoo search, introduced recently to solve optimization problems. A major advantage of this method is its simplicity: cuckoo search requires only two parameters, many fewer than other metaheuristic approaches, so the parameter tuning becomes a very simple task. The paper shows that this new approach can be successfully used to solve our optimization problem. To check the performance of our approach, it has been applied to five illustrative examples of different types, including open and closed 2D and 3D curves that exhibit challenging features, such as cusps and self-intersections. Our results show that the method performs pretty well, being able to solve our minimization problem in an astonishingly straightforward way.
The Hahn-Banach Extension Theorem for Fuzzy Normed Spaces Revisited
Authors: Alegre Carmen , Romaguera Salvador
Published: May 2014

This paper deals with fuzzy normed spaces in the sense of Cheng and Mordeson. We characterize fuzzy norms in terms of ascending and separating families of seminorms and prove an extension theorem for continuous linear functionals on a fuzzy normed space. Our result generalizes the classical Hahn-Banach extension theorem for normed spaces.
Glioprotective Effects of Ashwagandha Leaf Extract against Lead Induced Toxicity
Authors: Kumar Praveen , Singh Raghavendra , Nazmi Arshed , Lakhanpal Dinesh , Kataria Hardeep , Kaur Gurcharan
Published: May 2014

Withania somnifera(Ashwagandha), also known as Indian Ginseng, is a well-known Indian medicinal plant due to its antioxidative, antistress, antigenotoxic, and immunomodulatory properties. The present study was designed to assess and establish the cytoprotective potential of Ashwagandha leaf aqueous extract against lead induced toxicity. Pretreatment of C6 cells with 0.1% Ashwagandha extract showed cytoprotection against 25 μM to 400μM concentration of lead nitrate. Further pretreatment with Ashwagandha extract to lead nitrate exposed cells (200 μM) resulted in normalization of glial fibrillary acidic protein (GFAP) expression as well as heat shock protein (HSP70), mortalin, and neural cell adhesion molecule (NCAM) expression. Further, the cytoprotective efficacy of Ashwagandha extract was studiedin vivo. Administration of Ashwagandha extract provided significant protection to lead induced altered antioxidant defense that may significantly compromise normal cellular function. Ashwagandha also provided a significant protection to lipid peroxidation (LPx) levels, catalase, and superoxide dismutase (SOD) but not reduced glutathione (GSH) contents in brain tissue as well as peripheral organs, liver and kidney, suggesting its ability to act as a free radical scavenger protecting cells against toxic insult. These results, thus, suggest that Ashwagandha water extract may have the potential therapeutic implication against lead poisoning.
Effects and Mechanisms of Surface Topography on the Antiwear Properties of Molluscan Shells (Scapharca subcrenata) Using the Fluid-Solid Interaction Method
Authors: Tian Limei , Tian Ximei , Hu Guoliang , Wang Yinci , Ren Luquan
Published: May 2014

The surface topography (surface morphology and structure) of the leftScapharca subcrenatashell differs from that of its right shell. This phenomenon is closely related to antiwear capabilities. The objective of this study is to investigate the effects and mechanisms of surface topography on the antiwear properties ofScapharca subcrenatashells. Two models are constructed—a rib morphology model (RMM) and a coupled structure model (CSM)—to mimic the topographies of the right and left shells. The antiwear performance and mechanisms of the two models are studied using the fluid-solid interaction (FSI) method. The simulation results show that the antiwear capabilities of the CSM are superior to those of the RMM. The CSM is also more conducive to decreasing the impact velocity and energy of abrasive particles, reducing the probability of microcrack generation, extension, and desquamation. It can be deduced that in the real-world environment,Scapharca subcrenata’sleft shell sustains more friction than its right shell. Thus, the coupled structure of the left shell is the result of extensive evolution.
Molecular Testing for Fragile X: Analysis of 5062 Tests from 1105 Fragile X Families—Performed in 12 Clinical Laboratories in Spain
Authors: Tejada María-Isabel , Glover Guillermo , Martínez Francisco , Guitart Miriam , de Diego-Otero Yolanda , Fernández-Carvajal Isabel , Ramos Feliciano J. , Hernández-Chico Concepción , Pintado Elizabet , Rosell Jordi , Calvo María-Teresa , Ayuso Carmen , Ramos-Arroyo María-Antonia , Maortua Hiart , Milà Montserrat
Published: May 2014

Fragile X syndrome is the most common inherited form of intellectual disability. Here we report on a study based on a collaborative registry, involving 12 Spanish centres, of molecular diagnostic tests in 1105 fragile X families comprising 5062 individuals, of whom, 1655 carried a full mutation or were mosaic, three cases had deletions, 1840 had a premutation, and 102 had intermediate alleles. Two patients with the full mutation also had Klinefelter syndrome. We have used this registry to assess the risk of expansion from parents to children. From mothers with premutation, the overall rate of allele expansion to full mutation is 52.5%, and we found that this rate is higher for male than female offspring (63.6% versus 45.6%;P<0.001). Furthermore, in mothers with intermediate alleles (45–54 repeats), there were 10 cases of expansion to a premutation allele, and for the smallest premutation alleles (55–59 repeats), there was a 6.4% risk of expansion to a full mutation, with 56 repeats being the smallest allele that expanded to a full mutation allele in a single meiosis. Hence, in our series the risk for alleles of<59 repeats is somewhat higher than in other published series. These findings are important for genetic counselling.
Validation of Depth-Averaged Flow Model Using Flat-Bottomed Benchmark Problems
Authors: Seo Il Won , Kim Young Do , Song Chang Geun
Published: May 2014

In this study, a shallow water flow code was developed and tested against four benchmark problems of practical relevance. The results demonstrated that as the eddy viscosity increased, the velocity slope along the spanwise direction decreased, and the larger roughness coefficient induced a higher flow depth over the channel width. The mass conservation rate was determined to be 99.2%. This value was measured by the variation of the total volume of the fluid after a cylinder break. As the Re increased to 10,000 in the internal recirculating flow problem, the intensity of the primary vortex had a clear trend toward the theoretically infinite Re value of −1.886. The computed values of the supercritical flow evolved by the oblique hydraulic jump agreed well with the analytic solutions within an error bound of 0.2%. The present model adopts the nonconservative form of shallow water equations. These equations are weighted by the SU/PG scheme and integrated by a fully implicit method, which can reproduce physical problems with various properties. The model provides excellent results under various flow conditions, and the solutions of benchmark tests can present criteria for the evaluation of various algorithmic approaches.
The Flow Separation of Peristaltic Transport for Maxwell Fluid between Two Coaxial Tubes
Authors: Husseny S. Z. A. , Abd elmaboud Y. , Mekheimer Kh. S.
Published: May 2014

We study the peristaltic mechanism of an incompressible non-Newtonian biofluid (namely, Maxwell model) in the annular region between two coaxial tubes. The inner tube represents the endoscope tube. The system of the governing nonlinear PDE is solved by using the perturbation method to the first order in dimensionless wavenumber. The modified Newton-Raphson method is used to predict the flow separation points along the peristaltic wall and the endoscope tube. The results show that the presence of the endoscope (catheter) tube in the artery increases the pressure gradient and shear stress. Such a result seems too reasonable from the physical and medical point of view.