bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Flaxseed Oil Fortified with Vitamin E and Phytosterols on Antioxidant Defense Capacities and Lipids Profile in Rats
Authors: Deng Qianchun , Yu Xiao , Xu Jiqu , Liu Changsheng , Huang Fenghong , Huang Qingde , Yang Jine
Published: June 2012

Abstract:  The main proposal of this study was to evaluate in vivo whether flaxseed oils fortified with micronutrients would have beneficial effects on lipid profile and antioxidant status in high‐fat fed rats. Male Wistar rats were fed synthetic diets containing 10% of flaxseed oil (FO), phytosterols (PS) fortified FO (PS‐FO), vitamin E (VE) fortified FO (VE‐FO), VE, and PS fortified FO (VE‐PS‐FO), respectively, for 4 wk. The results showed that VE fortified FO enhanced the enzymatic (SOD and GPX) and nonenzymatic (GSH and VE) antioxidant system, lowered the lipid peroxide (TBARS) concentration compared with FO (P < 0.05). And FO fortified with PS significantly reduced the plasma TG, TC and LDL‐C levels, and hepatic TG and TC levels of rats compared with FO (P < 0.05), but had no significant effect on antioxidant defense capacities. Combined addition of VE and PS in FO had a synergetic effect. These results indicated that flaxseed oils fortified micronutrients VE and PS may contribute to reduce the risk factors of cardiovascular disease (CVD) by improving plasma antioxidant defenses and lipids profiles.

Practical Application:  Flaxseed oil usually contains greater than 50% of alpha‐linolenic acid (ALA) and is a desire origin for n‐3 PUFA. But consuming high dose of n‐3 PUFA could lead to oxidative damage through free radical‐chain reaction in cellular and subcellular membranes. Our studies showed that a regular intake of VE and PS fortified flaxseed oils increased antioxidant defenses and ameliorated lipids profile in high‐fat fed rats, and these indicated that the flaxseed oil fortified with these micronutrients might reduce the incidence of CVD.
Flow cytometric detection of alpha‐1‐acid glycoprotein on feline circulating leucocytes
Authors: Paltrinieri S , Marchini I , Gelain ME
Published: June 2012

Objective

To assess whether alpha‐1‐acid glycoprotein (AGP) can be detected on the membrane of feline circulating leucocytes.

Design  The presence of AGP on circulating leucocytes was investigated in both clinically healthy cats and cats with different diseases. A group of feline coronavirus (FCoV)‐positive cats, comprising cats with feline infectious peritonitis (FIP) and cats not affected by FIP but seropositive for FCoV, were included in this study because the serum concentration of AGP increases during FCoV infection.

Procedure  Flow cytometry (using an anti‐feline AGP antibody), serum protein electrophoresis, routine haematology and measurement of the serum AGP concentration were performed using blood samples from 32 healthy cats (19 FCoV‐seropositive), 13 cats with FIP and 12 with other diseases (6 FCoV‐seropositive). The proportion of cats with AGP‐positive leucocytes in the different groups (e.g. controls vs sick; FIP vs other diseases, etc.) or in cats with different intensities of inflammatory response was compared using a Chi‐square test.

Results  AGP‐positive leucocytes were found in 23% of cats. Compared with controls, the proportion of patients with positive granulocytes and monocytes was higher among sick cats (especially cats with diseases other than FIP) and cats with high serum AGP concentration, but not in cats with leucocytosis or that were FCoV‐seropositive.

Conclusion  AGP‐positive leucocytes can be found in feline blood, especially during inflammation. Conversely, no association between AGP‐positive leucocytes and FIP was found. Further studies are needed to elucidate the mechanism responsible for this finding and its diagnostic role in cats with inflammation.
Blood Pressure Effects of Combined β‐Blocker and Angiotensin‐Converting Enzyme Inhibitor Therapy Compared With the Individual Agents: A Placebo‐Controlled Study With Nebivolol and Lisinopril
Authors: Weber Michael A. , Basile Jan , Stapff Manfred , Khan Barbara , Zhou Dongli
Published: June 2012

J Clin Hypertens (Greenwich). 2012; 14:588–592. © 2012 Wiley Periodicals, Inc.

Blood pressure (BP) reductions when combining blockers of the renin‐angiotensin system (RAS) and β‐blockers have generally not been shown to be greater than for individual agents, possibly because of overlapping mechanisms of action. The authors tested the additivity of the β‐blocker nebivolol, which has vasodilating activity, with the angiotensin‐converting enzyme inhibitor lisinopril in patients with stage 2 diastolic hypertension. The BP effects of placebo (n=93), nebivolol 5 mg to 20 mg daily (n=185), lisinopril 10 mg to 40 mg daily (n=189), and nebivolol 5 mg to 20 mg + lisinopril 10 mg to 40 mg (n=189) during 6 weeks of treatment were compared. The primary end point was change in diastolic BP (DBP). For the full cohort, baseline BP was 163.8/104.4 mm Hg, mean age was 49.2 years, 58% were men, 62% were white, and 34% were black. DBP fell by 17.2±10.2 mm Hg with the combination, greater than placebo (8.0±9.2, P<.0001), nebivolol (13.3±8.9, P=.0010), and lisinopril (12.0±9.8, P<.0001). For systolic BP, corresponding reductions were 19.2±19.8 mm Hg, 9.9±16.4 (P<.0001 vs combination), 14.4±14.1 (P=.0470), and 16.1±17.2 (P=.0704). Adverse event rates were similar in all groups. This study demonstrated the potential antihypertensive benefits of combining nebivolol with a RAS blocker.
Unterschiedliche Entwicklung der gesetzlichen Krankenversicherung in Japan und in der Republik Korea: Mehrkassensystem gegenüber Einheitskasse
Authors: Jeong Hyoung‐Sun , Niki Ryu
Published: June 2012

Auszug

Japan und die Republik Korea verwirklichten die allgemeine Krankenversicherung für ihre Bevölkerung 1961 beziehungsweise 1989. Derzeit betreibt Japan weiterhin ein soziales Krankenversicherungssystem mit einer Vielzahl von Kassen, während die Republik Korea zu einer integrierten Einheitskasse für die nationale Krankenversicherung übergegangen ist. Dieser Artikel analysiert den Einfluss der politischen Ökonomie auf die Entwicklung der grundsatzpolitischen Unterschiede zwischen diesen beiden Krankenversicherungssystemen nach dem Bismarck'schen Modell. Zu den Themen, auf die eingegangen wird, zählen etwa Unterschiede der politischen Macht, der politische Einfluss der Wirtschaft, die Frage, inwieweit sich eine regionale Autonomie entwickelt hat und regionale Besonderheiten beibehalten wurden, der Grad der politischen Demokratisierung, die Form der politischen Führung und das Ausmaß der Entwicklung des Krankenversicherungssystems. Aus den Erfahrungen beider Länder werden grundsatzpolitische Erkenntnisse abgeleitet.
Implizite Schulden von Rentenplänen des öffentlichen Sektors: Ein internationaler Vergleich
Authors: Ponds Eduard , Severinson Clara , Yermo Juan
Published: June 2012

Auszug

Die meisten Länder haben für die Angestellten des öffentlichen Sektors separate Rentenpläne. Die zukünftige Belastung des Staatshaushalts durch diese Rentenpläne kann beträchtlich sein, da der Staat gewöhnlich der größte Arbeitgeber ist, die Rentenversprechen im öffentlichen Sektor tendenziell relativ großzügig sind und zukünftige Zahlungen direkt aus Staatseinnahmen (Umlageverfahren) oder durch tendenziell unterfinanzierte kapitalgedeckte Rentenfondspläne bestritten werden müssen. Bei der Bewertung und Veröffentlichung dieser Rentenversprechen fehlt es in einigen Ländern an Transparenz, sodass möglicherweise enorme Haushaltsverpflichtungen an zukünftige Arbeitnehmergenerationen weitergegeben werden. Um die Haushaltsbelastungen durch die Rentenpläne des öffentlichen Sektors in den verschiedenen Ländern fair vergleichen zu können, empfiehlt dieser Artikel zwecks besserer Transparenz der öffentlichen Finanzen und zur Erleichterung der politischen Entscheidungsfindung, die ungedeckten Rentenverbindlichkeiten nach einem Standardansatz zu erfassen und zu veröffentlichen. Von einer Auswahl von Mitgliedsstaaten der Organisation für wirtschaftliche Zusammenarbeit und Entwicklung wird eine Schätzung der ungedeckten Verbindlichkeiten per Ende 2008 als beizulegende Zeitwerte (fair values) vorgelegt. Diese Haushaltsbelastung kann auch als beizulegender Zeitwert der impliziten Rentenschulden interpretiert werden.
La expansión de la cobertura del sistema argentino de pensiones: distribución del acceso y perspectivas para la universalización
Authors: Arza Camila
Published: June 2012

Uno de los desafíos centrales de la política social latinoamericana es garantizar seguridad social para toda la población en contextos de alta informalidad laboral. En la Argentina, un país pionero en el desarrollo de los sistemas de pensiones en la región, más de un tercio de las personas en edad jubilatoria carecían de beneficios en 2005. A partir de entonces la cobertura se expandió sustancialmente como resultado de la implementación de un programa que relajó los requisitos contributivos y otorgó beneficios a un gran número de adultos mayores que se hallaban fuera del sistema. Esta investigación analiza el impacto de este proceso sobre el nivel y distribución de la cobertura, identifica los cambios en los factores sociodemográficos asociados a la inclusión/exclusión del sistema previsional argentino, y discute los obstáculos que persisten para alcanzar una cobertura universal en el mediano y largo plazo.
La información individual para el cotizante: algunas recomendaciones para el caso español a partir de la experiencia internacional
Authors: Regúlez‐Castillo Marta , Vidal‐Meliá Carlos
Published: June 2012

Este artículo tiene por objetivo definir directrices básicas para facilitar el eventual diseño de un boletín de información que se enviaría a los cotizantes del sistema estatal de pensiones de España, en caso de adoptarse dicho instrumento. Inspirándonos de la experiencia internacional y de la investigación realizada en este ámbito por Jackson (2005), Larsson, Sundén y Settergren (2008) y Sundén (2009), investigamos el concepto de información individual sobre pensiones y determinamos sus principales características. Luego, describimos en detalle dos modelos de suministro de información individual sobre pensiones, el de los Estados Unidos y el de Suecia, haciendo hincapié en su estructura, en los aspectos mejorables y en sus limitaciones. Por último, presentamos algunas recomendaciones para el diseño del modelo español.
TAKING STOCK OF PHENOMENOLOGY FUTURES
Authors: GALLAGHER SHAUN
Published: June 2012

abstract

In this paper, I review recent contributions of phenomenology to a variety of disciplines, including the cognitive sciences and psychiatry, and explore (1) controversies about phenomenological methods and naturalization; (2) relations between phenomenology and the enactive and extended mind approaches; and (3) the promise of phenomenology for addressing a number of controversial philosophical issues.
Controller Design for Systems With Multipacket Transmissions
Authors: Guo Ge , Lu Zibao , Jin Hui
Published: June 2012

This paper investigates the problem of stability analysis and state-space-equation controller design for a type of nonlinear systems in which measurement data of the sensors and the control signals are communicated through independent communication channels via a multiple-packet transmission policy. The packet delays (and dropouts) at the sensors side and the actuators side are assumed to be different in properties and are treated separately. A framework of stability analysis and controller design under multiple-packet transmission policy is derived by simultaneous consideration of quantization effect, successive packet delays, dropouts, and noises. The main results are obtained by constructing a new Lyapunov functional and using a new tight bounding technique without introducing any free-weighting matrices. As a general tool for designing state-space-equation controllers for networked control systems, the presented method is less conservative with reduced number of variables and larger upper bounds of time-delays, which is shown by numerical examples.
Pressure Side and Cutback Trailing Edge Film Cooling in a Linear Nozzle Vane Cascade at Different Mach Numbers
Authors: Barigozzi Giovanna , Perdichizzi Antonio , Ravelli Silvia
Published: June 2012

Tests on a specifically designed linear nozzle guide vane cascade with trailing edge coolant ejection were carried out to investigate the influence of trailing edge bleeding on both aerodynamic and thermal performance. The cascade is composed of six vanes with a profile typical of a high pressure turbine stage. The trailing edge cooling features a pressure side cutback with film cooling slots, stiffened by evenly spaced ribs in an inline configuration. Cooling air is ejected not only through the slots but also through two rows of cooling holes placed on the pressure side, upstream of the cutback. The cascade was tested for different isentropic exit Mach numbers, ranging from M2is = 0.2 to M2is = 0.6, while varying the coolant to mainstream mass flow ratio MFR up to 2.8%. The momentum boundary layer behavior at a location close to the trailing edge, on the pressure side, was assessed by means of laser Doppler measurements. Cases with and without coolant ejection allowed us to identify the contribution of the coolant to the off the wall velocity profile. Thermochromic liquid crystals (TLC) were used to map the adiabatic film cooling effectiveness on the pressure side cooled region. As expected, the cutback effect on cooling effectiveness, compared to the other cooling rows, was dominant.
Energy Optimal Control of Servo-Pneumatic Cylinders Through Nonlinear Static Feedback Linearization
Authors: Wang Jihong , Gordon Tim
Published: June 2012

Although pneumatic actuators are widely used in industry, they have two major weaknesses—nonlinearities associated with compressibility of air and low energy efficiency. The former limits its applicability whenever accurate positioning is required, and the latter has a negative impact on users through increased energy costs. This paper addresses these issues with the aim of developing a widely applicable servo control strategy, which combines improved tracking accuracy and energy efficiency. A detailed actuator system model is linearized through nonlinear input–output feedback linearization, and the energy optimal velocity profile is derived. Simulation and experimental studies indicate that energy efficiency improvements of 3–7% are possible, while tracking accuracy can be ensured. The method is suitable for real-time implementation and is cost effective; it requires the implementation of an improved velocity profile, while hardware components do not need to be altered.
Effects of Pin Detached Space on Heat Transfer and Pin-Fin Arrays
Authors: Siw Sin Chien , Chyu Minking K. , Shih Tom I.-P. , Alvin Mary Anne
Published: June 2012

Heat transfer and pressure characteristics in a rectangular channel with pin-fin arrays of partial detachment from one of the endwalls have been experimentally studied. The overall channel geometry (W = 76.2 mm, E = 25.4 mm) simulates an internal cooling passage of wide aspect ratio (3:1) in a gas turbine airfoil. With a given pin diameter, D = 6.35 mm = ¼E, three different pin-fin height-to-diameter ratios, H/D = 4, 3, and 2, were examined. Each of these three cases corresponds to a specific pin array geometry of detachment spacing (C) between the pin tip and one of the endwalls, i.e., C/D = 0, 1, 2, respectively. The Reynolds number, based on the hydraulic diameter of the unobstructed cross-section and the mean bulk velocity, ranges from 10,000 to 25,000. The experiment employs a hybrid technique based on transient liquid crystal imaging to obtain the distributions of the local heat transfer coefficient over all of the participating surfaces, including the endwalls and all the pin elements. Experimental results reveal that the presence of a detached space between the pin tip and the endwall has a significant effect on the convective heat transfer and pressure loss in the channel. The presence of pin-to-endwall spacing promotes wall-flow interaction, generates additional separated shear layers, and augments turbulent transport. In general, an increase in detached spacing, or C/D, leads to lower heat transfer enhancement and pressure drop. However, C/D = 1, i.e., H/D = 3, of a staggered array configuration exhibits the highest heat transfer enhancement, followed by the cases of C/D = 0 and C/D = 2, i.e., H/D = 4 or 2, respectively.
Phonon Transport Modeling Using Boltzmann Transport Equation With Anisotropic Relaxation Times
Authors: Ni Chunjian , Murthy Jayathi Y.
Published: June 2012

A sub-micron thermal transport model based on the phonon Boltzmann transport equation (BTE) is developed using anisotropic relaxation times. A previously-published model, the full-scattering model, developed by Wang, directly computes three-phonon scattering interactions by enforcing energy and momentum conservation. However, it is computationally very expensive because it requires the evaluation of millions of scattering interactions during the iterative numerical solution procedure. The anisotropic relaxation time model employs a single-mode relaxation time, but the relaxation time is derived from detailed consideration of three-phonon interactions satisfying conservation rules, and is a function of wave vector. The resulting model is significantly less expensive than the full-scattering model, but incorporates directional and dispersion behavior. A critical issue in the model development is the role of three-phonon normal (N) scattering processes. Following Callaway, the overall relaxation rate is modified to include the shift in the phonon distribution function due to N processes. The relaxation times so obtained are compared with the data extracted from equilibrium molecular dynamics simulations by Henry and Chen. The anisotropic relaxation time phonon BTE model is validated by comparing the predicted thermal conductivities of bulk silicon and silicon thin films with experimental measurements. The model is then used for simulating thermal transport in a silicon metal-oxide-semiconductor field effect transistor (MOSFET) and leads to results close to the full-scattering model, but uses much less computation time.
Determining Model Accuracy Requirements for Automotive Engine Coldstart Hydrocarbon Emissions Control
Authors: Azad Nasser L. , Sanketi Pannag R. , Hedrick J. Karl
Published: June 2012

In this work, a systematic method is introduced to determine the required accuracy of an automotive engine model used for real-time optimal control of coldstart hydrocarbon (HC) emissions. The engine model structure and development are briefly explained and the model predictions versus experimental results are presented. The control design problem is represented with a dynamic optimization formulation on the basis of the engine model and solved using the Pontryagin’s minimum principle (PMP). To relate the level of plant/model mismatch and the control performance degradation in practice, a sensitivity analysis using a computationally efficient method is employed. In this way, the sensitivities or the effects of small parameter variations on the optimal solution, which is the minimum of cumulative tailpipe HC emissions over the coldstart period, are calculated. There is a good agreement between the sensitivity analysis results and the experimental data. The sensitivities indicate the directions of the subsequent parameter estimation and model improvement tasks to enhance the control-relevant accuracy, and thus, the control performance. Furthermore, they provide some insights to simplify the engine model, which is critical for real-time implementation of the coldstart optimal control system.
Resonance Tracking of Continua Using Self-Sensing Actuators
Authors: Kern Dominik , Brack Tobias , Seemann Wolfgang
Published: June 2012

This paper proposes and develops an innovative method to solve the resonance tracking problem for actuator and sensor applications to obtain maximum power transmission or signal selectivity using a modified phase-locked loop (PLL). The tracking of a higher eigenfrequency is very useful in some cases, but it is more challenging than the excitation of the only eigenfrequency of a 1-DoF system. The resonances are identified through employing their characteristic phase difference. The conventional PLL was modified to track a certain phase difference without deviation. The closed loop is a nonlinear control system due to the conversion between harmonic signals and phase signals. However, a model simplification to linear elements allows the goal oriented determination of the controller parameters. The advantages of self-sensing in combination with resonance tracking are attractive for practical applications such as ultrasonic motors and compact force sensors. The conducted experiments approved the effectiveness of the resonant excitation of higher oscillation modes of continua using self-sensing actuators.
Nonlinear Estimation Techniques Applied on Target Tracking Problems
Authors: Gadsden Andrew , Habibi Saeid , Dunne Darcy , Kirubarajan T.
Published: June 2012

This paper discusses the application of four nonlinear estimation techniques on two benchmark target tracking problems. The first problem is a generic air traffic control (ATC) scenario, which involves nonlinear system equations with linear measurements. The second study is a classical ground surveillance problem, where a moving airborne platform with a sensor is used to track a moving target. The tracking scenario is set in two dimensions, with the measurement providing nonlinear bearing-only observations. These two target tracking problems provide a good benchmark for comparing the following nonlinear estimation techniques: the common extended and unscented Kalman filters (EKF/UKF), the particle filter (PF), and the relatively new smooth variable structure filter (SVSF). The results of applying the SVSF on the two target tracking problems demonstrate its stability and robustness. Both of these attributes make use of the SVSF advantageous over other popular methods. The filters performances are quantified in terms of robustness, resilience to poor initial conditions and measurement outliers, and tracking accuracy and computational complexity. The purpose of this paper is to demonstrate the effectiveness of applying the SVSF on nonlinear target tracking problems, which in the past have typically been solved by Kalman or particle filters.
Unsteady Wake and Coolant Density Effects on Turbine Blade Film Cooling Using Pressure Sensitive Paint Technique
Authors: Rallabandi Akhilesh P. , Li Shiou-Jiuan , Han Je-Chin
Published: June 2012

The effect of an unsteady stator wake (simulated by wake rods mounted on a spoke-wheel wake generator) on the modeled rotor blade is studied using the pressure sensitive paint (PSP) mass-transfer analogy method. Emphasis of the current study is on the midspan region of the blade. The flow is in the low Mach number (incompressible) regime. The suction (convex) side has simple angled cylindrical film-cooling holes; the pressure (concave) side has compound angled cylindrical film-cooling holes. The blade also has radial shower-head leading edge film-cooling holes. Strouhal numbers studied range from 0 to 0.36; the exit Reynolds number based on the axial chord is 530,000. Blowing ratios range from 0.5 to 2.0 on the suction side and 0.5 to 4.0 on the pressure side. Density ratios studied range from 1.0 to 2.5, to simulate actual engine conditions. The convex suction surface experiences film-cooling jet lift-off at higher blowing ratios, resulting in low effectiveness values. The film coolant is found to reattach downstream on the concave pressure surface, increasing effectiveness at higher blowing ratios. Results show deterioration in film-cooling effectiveness due to increased local turbulence caused by the unsteady wake, especially on the suction side. Results also show a monotonic increase in film-cooling effectiveness on increasing the coolant to mainstream density ratio.
Evaporation-assisted high-power impulse magnetron sputtering: The deposition of tungsten oxide as a case study
Authors: Hemberg Axel , Dauchot Jean-Pierre , Snyders Rony , Konstantinidis Stephanos
Published: June 2012

The deposition rate during the synthesis of tungsten trioxide thin films by reactive high-power impulse magnetron sputtering (HiPIMS) of a tungsten target increases, above the dc threshold, as a result of the appropriate combination of the target voltage, the pulse duration, and the amount of oxygen in the reactive atmosphere. This behavior is likely to be caused by the evaporation of the low melting point tungsten trioxide layer covering the metallic target in such working conditions. The HiPIMS process is therefore assisted by thermal evaporation of the target material.
In situ study of erosion and deposition of amorphous hydrogenated carbon films by exposure to a hydrogen atom beam
Authors: Markelj Sabina , Pelicon Primož , Čadež Iztok , Schwarz-Selinger Thomas , Jacob Wolfgang
Published: June 2012

This paper reports on the first dual-beam experiment employing a hydrogen atom beam for sample exposure and an ion beam for analysis, enabling in situ and real-time studies of hydrogen atom interaction with materials. The erosion of an amorphous hydrogenated carbon (a-C:H) layer by deuterium atoms at 580 K sample temperature was studied and the uptake of deuterium during the erosion process was measured in real time. The deuterium areal density increased at the beginning to 7.3 × 1015 D cm−2, but then stabilized at a constant value of 5.5 × 1015 D cm−2. Formation of a polymer-like deposit on an a-C:H layer held at room temperature and subjected to the deuterium atom beam was observed and also studied in situ. For both erosion and deposition studies an a-13C:H layer on top of an Si substrate was used as a sample, making the experiments isotopically fully specified and thereby differentiating the deposited from the original layer and the interacting D atoms from H atoms present in the layer and in the residual vacuum. From the deposition study it was shown that carbon in the deposited layer originates from carbon-carrying species in the background vacuum that interact with hydrogen atoms. The areal density of the carbon at the surface was determined from the energy shift of the Si edge in the Rutherford backscattering spectrum. The cross section for 7Li on D at 4.3 MeV Li ion energy and at a recoil angle of 30° was also determined to be (236 ± 16) × 10−27 cm2/sr. This is a factor of 3 ± 0.2 times higher than the Rutherford elastic cross section.
Characterization of geometrical factors for quantitative angle-resolved photoelectron spectroscopy
Authors: Martinez Eugenie , Herrera-Gomez Alberto , Allain Mickael , Renault Olivier , Faure Alain , Chabli Amal , Bertin Francois
Published: June 2012

For conventional angle-resolved x-ray photoelectron spectroscopy (ARXPS), the area under the core-level peaks depends mainly on the in-depth distribution of chemical species at the top surface of a specimen. But the x-ray photoelectron spectroscopy (XPS) intensity is also affected by tool-related geometrical factors such as the shape of the x-ray beam, the spectrometer analysis volume, and the manipulator rotation axis. Data analysis is therefore typically based on normalization with respect to the signal from the substrate. Here, we present an original method to perform quantitative ARXPS without normalization, involving evaluation of these geometrical factors. The method is illustrated for a multiprobe XPS system using a methodology based on a specific software (XPSGeometry®), but is a general process that can be adapted to all types of XPS equipment, even those not specifically designed for ARXPS. In that case, this method enables bringing the sample as close as possible to the manipulator axis of rotation in order to perform automatic acquisitions.
Labeling and Identification of Direct Kinase Substrates
Authors: Carlson Scott M. , White Forest M.
Published: June 2012

A strategy that uses analog-sensitive kinases enables the identification of low-abundance kinase substrates.
Matrix Rigidity Controls Endothelial Differentiation and Morphogenesis of Cardiac Precursors
Authors: Kshitiz  , Hubbi Maimon E. , Ahn Eun Hyun , Downey John , Afzal Junaid , Kim Deok-Ho , Rey Sergio , Chang Connie , Kundu Arnab , Semenza Gregg L. , Abraham Roselle M. , Levchenko Andre
Published: June 2012

Culturing cardiac precursors on a surface with the rigidity of heart tissue increases the yield of endothelial cells.
F-Box Proteins Elongate Translation During Stress Recovery
Authors: Meloche Sylvain , Roux Philippe P.
Published: June 2012

An inhibitor of protein synthesis is activated by DNA damage and degraded during recovery.
Dissecting Chitin Binding
Authors: Hines Pamela J.
Published: June 2012

Structural analysis shows how fungus-derived chitin dimerizes its receptor on target plants and triggers defense responses.
So Selective
Authors: Mueller Kristen L.
Published: June 2012

Restricted B cell signaling in the areas responsible for immune memory cell production promotes affinity maturation.
Saquinavir Inhibits Early Events Associated with Establishment of HIV-1 Infection: Potential Role for Protease Inhibitors in Prevention
Authors: Stefanidou Martha , Herrera Carolina , Armanasco Naomi , Shattock Robin J.
Published: June 2012

The maturation of newly formed human immunodeficiency virus type 1 (HIV-1) virions is a critical step for the establishment of productive infection. We investigated the potential of saquinavir (SQV), a protease inhibitor (PI) used in highly active antiretroviral therapy (HAART), as a candidate microbicide. SQV inhibited replication of clade B and clade C isolates in a dose-dependent manner in all cellular models tested: PM-1 CD4 T cells, peripheral blood mononuclear cells (PBMCs), monocyte-derived macrophages (MDMs), and immature monocyte-derived dendritic cells (iMDDCs). SQV also inhibited production of infectious virus in cervical, penile, and colorectal explants cocultured with T cells. Moreover, SQV demonstrated inhibitory potency againsttransinfection of T cells byin vitro-derived dendritic cells and by primary dendritic cells that emigrate from penile and cervical tissue explants. No cellular or tissue toxicity was detected in the presence of SQV, suggesting that this drug could be considered for development as a component of an effective microbicide, capable of blocking viral maturation and transmission of HIV-1 at mucosal surfaces.
Crystal Structure of the Mobile Metallo-β-Lactamase AIM-1 from Pseudomonas aeruginosa: Insights into Antibiotic Binding and the Role of Gln157
Authors: Leiros Hanna-Kirsti S. , Borra Pardha S. , Brandsdal Bjørn Olav , Edvardsen Kine Susann Waade , Spencer James , Walsh Timothy R. , Samuelsen Ørjan
Published: June 2012

Metallo-β-lactamase (MBL) genes confer resistance to virtually all β-lactam antibiotics and are rapidly disseminated by mobile genetic elements in Gram-negative bacteria. MBLs belong to three different subgroups, B1, B2, and B3, with the mobile MBLs largely confined to subgroup B1. The B3 MBLs are a divergent subgroup of predominantly chromosomally encoded enzymes. AIM-1 (
A
delaide
IM
ipenmase 1) from
Pseudomonas aeruginosa
was the first B3 MBL to be identified on a readily mobile genetic element. Here we present the crystal structure of AIM-1 and use
in silico
docking and quantum mechanics and molecular mechanics (QM/MM) calculations, together with site-directed mutagenesis, to investigate its interaction with β-lactams. AIM-1 adopts the characteristic αβ/βα sandwich fold of MBLs but differs from other B3 enzymes in the conformation of an active site loop (residues 156 to 162) which is involved both in disulfide bond formation and, we suggest, interaction with substrates. The structure, together with docking and QM/MM calculations, indicates that the AIM-1 substrate binding site is narrower and more restricted than those of other B3 MBLs, possibly explaining its higher catalytic efficiency. The location of Gln157 adjacent to the AIM-1 zinc center suggests a role in drug binding that is supported by our
in silico
studies. However, replacement of this residue by either Asn or Ala resulted in only modest reductions in AIM-1 activity against the majority of β-lactam substrates, indicating that this function is nonessential. Our study reveals AIM-1 to be a subclass B3 MBL with novel structural and mechanistic features.
First-in-Human Study of the Pharmacokinetics and Antiviral Activity of IDX375, a Novel Nonnucleoside Hepatitis C Virus Polymerase Inhibitor
Authors: de Bruijne J. , van de Wetering de Rooij J. , van Vliet A. A. , Zhou X. J. , Temam M. F. , Molles J. , Chen J. , Pietropaolo K. , Sullivan-Bólyai J. Z. , Mayers D. , Reesink H. W.
Published: June 2012

IDX375 is a potent and selective palm-binding nonnucleoside inhibitor of the hepatitis C virus (HCV) genotype 1 polymerase. This first-in-human study evaluated the safety, tolerability, and pharmacokinetics of IDX375 in healthy volunteers, as well as its antiviral activity in HCV-infected patients. IDX375, as a choline salt, was administered for 1 day to 40 healthy male volunteers (25- to 200-mg IDX375-equivalent single ascending doses and a 200-mg twice-daily [BID] dose) and three patients chronically infected with HCV genotype 1 (200 mg BID only). IDX375 was well absorbed and well tolerated by all of the study participants. A single-day 200-mg BID dose resulted in exposure-related anti-HCV activity with maximal 0.5 to 1.1 log
10
reductions in plasma HCV RNA. These observations support further clinical investigations of IDX375.
Plasmid-Mediated Quinolone Resistance in Extended-Spectrum-β-Lactamase- and AmpC β-Lactamase-Producing Serratia marcescens in China
Authors: Yang Hai-Fei , Cheng Jun , Hu Li-Fen , Ye Ying , Li Jia-Bin
Published: June 2012

We investigated the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants and examined the association of these determinants with extended-spectrum β-lactamases (ESBLs) and/or plasmid-mediated AmpC β-lactamases (pAmpCs) in
Serratia marcescens
isolates in China. In this study, the presence of PMQR determinants was significantly related to the coproduction of ESBLs and/or pAmpCs (CTX-M-14, SHV-5, DHA-1, and ACT-1), among which CTX-M-14 was the most common gene type.
Inhibition of Biofilm Formation by Esomeprazole in Pseudomonas aeruginosa and Staphylococcus aureus
Authors: Singh Vandana , Arora Vaneet , Alam M. Jahangir , Garey Kevin W.
Published: June 2012

Staphylococcus aureus
and
Pseudomonas aeruginosa
are common nosocomial pathogens responsible for biofilm-associated infections. Proton pump inhibitors (PPI), such as esomeprazole, may have novel antimicrobial properties. The objective of this study was to assess whether esomeprazole prevents sessile bacterial growth and biofilm formation and whether it may have synergistic killing effects with standard antibiotics. The antibiofilm activity of esomeprazole at 0.25 mM was tested against two strains each of
S. aureus
and
P. aeruginosa
. Bacterial biofilms were prepared using a commercially available 96-peg-plate Calgary biofilm device. Sessile bacterial CFU counts and biomass were assessed during 72 hours of esomeprazole exposure. The killing activities after an additional 24 hours of vancomycin (against
S. aureus
) and meropenem (against
P. aeruginosa
) treatment with or without preexposure to esomeprazole were also assessed by CFU and biomass analyses.
P. aeruginosa
and
S. aureus
strains exposed to esomeprazole displayed decreased sessile bacterial growth and biomass (
P
< 0.001, each parameter). After 72 h of exposure, there was a 1-log
10
decrease in the CFU/ml of esomeprazole-exposed
P. aeruginosa
and
S. aureus
strains compared to controls (
P
< 0.001). After 72 h of exposure, measured absorbance was 100% greater in
P. aeruginosa
control strains than in esomeprazole-exposed strains (
P
< 0.001). Increased killing and decreased biomass were observed for esomeprazole-treated bacteria compared to untreated controls exposed to conventional antibiotics (
P
< 0.001, each parameter). Reduced biofilm growth after 24 h was visibly apparent by light micrographs for
P. aeruginosa
and
S. aureus
isolates exposed to esomeprazole compared to untreated controls. In conclusion, esomeprazole demonstrated an antibiofilm effect against biofilm-producing
S. aureus
and
P. aeruginosa
.
Effect of Sodium Fluoride, Ampicillin, and Chlorhexidine on Streptococcus mutans Biofilm Detachment
Authors: Liu Jia , Ling Jun-Qi , Zhang Kai , Huo Li-Jun , Ning Yang
Published: June 2012

We examined the effect of three clinically used antimicrobials on
Streptococcus mutans
UA159 biofilm detachment under flow conditions. Sodium fluoride (NaF) and chlorhexidine at MIC levels promoted biofilm detachment and inhibited detachment when concentrations were higher than the MIC and reduced detached-cell viability only at high concentrations. Ampicillin at all concentrations tested inhibited detachment and reduced the percentage of viable biofilm-detached cells. All the three antimicrobial treatments reduced biofilm live/dead cell ratios.
Dose-Ranging Comparison of Rifampin and Rifapentine in Two Pathologically Distinct Murine Models of Tuberculosis
Authors: Rosenthal Ian M. , Tasneen Rokeya , Peloquin Charles A. , Zhang Ming , Almeida Deepak , Mdluli Khisimuzi E. , Karakousis Petros C. , Grosset Jacques H. , Nuermberger Eric L.
Published: June 2012

In previous experiments, replacing the 10-mg/kg of body weight daily dose of rifampin with 7.5 to 10 mg/kg of rifapentine in combinations containing isoniazid and pyrazinamide reduced the duration of treatment needed to cure tuberculosis in BALB/c mice by approximately 50% due to rifapentine's more potent activity and greater drug exposures obtained. In the present study, we performed dose-ranging comparisons of the bactericidal and sterilizing activities of rifampin and rifapentine, alone and in combination with isoniazid and pyrazinamide with or without ethambutol, in BALB/c mice and in C3HeB/FeJ mice, which develop necrotic lung granulomas after infection with
Mycobacterium tuberculosis
. Each rifamycin demonstrated a significant increase in sterilizing activity with increasing dose. Rifapentine was roughly 4 times more potent in both mouse strains. These results reinforce the rationale for ongoing clinical trials to ascertain the highest well-tolerated doses of rifampin and rifapentine. This study also provides an important benchmark for the efficacy of the first-line regimen in C3HeB/FeJ mice, a strain in which the lung lesions observed after
M. tuberculosis
infection may better represent the pathology of human tuberculosis.
Decreased Expression of Type 1 Fimbriae by apstMutant of Uropathogenic Escherichia coli Reduces Urinary Tract Infection
Authors: Crépin Sébastien , Houle Sébastien , Charbonneau Marie-Ève , Mourez Michaël , Harel Josée , Dozois Charles M.
Published: June 2012

ThepstSCAB-phoUoperon encodes the phosphate-specific transport system (Pst). Loss of Pst constitutively activates the Pho regulon and decreases bacterial virulence. However, specific mechanisms underlying decreased bacterial virulence through inactivation of Pst are poorly understood. In uropathogenicEscherichia coli(UPEC) strain CFT073, inactivation ofpstdecreased urinary tract colonization in CBA/J mice. Thepstmutant was deficient in production of type 1 fimbriae and showed decreased expression of thefimAstructural gene which correlated with differential expression of thefimB,fimE,ipuA, andipbAgenes, encoding recombinases, mediating inversion of thefimpromoter. The role offimdownregulation in attenuation of thepstmutant was confirmed using afimphase-locked-on derivative, which demonstrated a significant gain in virulence. In addition, thepstmutant was less able to invade human bladder epithelial cells. Since type 1 fimbriae contribute to UPEC virulence by promoting colonization and invasion of bladder cells, the reduced bladder colonization by thepstmutant is predominantly attributed to downregulation of these fimbriae. Elucidation of mechanisms mediating the control of type 1 fimbriae through activation of the Pho regulon in UPEC may open new avenues for therapeutics or prophylactics against urinary tract infections.
Distinguishing the Contribution of Type 1 Pili from That of Other QseB-Misregulated Factors when QseC Is Absent during Urinary Tract Infection
Authors: Kostakioti Maria , Hadjifrangiskou Maria , Cusumano Corinne K. , Hannan Thomas J. , Janetka James W. , Hultgren Scott J.
Published: June 2012

Urinary tract infections (UTI), primarily caused by uropathogenicEscherichia coli(UPEC), are one of the leading bacterial infections due to their high frequency and rate of recurrence. Both type 1 pilus adhesive organelles (fim) and the QseC sensor kinase have been implicated in UPEC virulence during UTI and have been individually reported to be promising drug targets. Deletion ofqseCleads to pleiotropic effects due to unregulated activation of the cognate response regulator QseB, influencing conserved metabolic processes and diminishing expression of virulence genes, including type 1 pili. Here, we discern the type 1 pilus-dependent and -independent effects that contribute to the virulence attenuation of a UPECqseCdeletion mutant in a murine model of experimental UTI. We show that although a ΔqseCmutant restored for type 1 pilus expression regains the ability to colonize the host and initiate acute infection up to 16 h postinfection, it is rapidly outcompeted during acute infection when coinoculated with a wild-type strain. As a result, this strain has a diminished capacity to establish chronic infection. A prophylactic oral dose of a FimH small-molecular-weight antagonist (ZFH-02056) further reduced the ability of theqseCmutant to establish chronic infection. Thus, loss of QseC significantly enhances the efficacy of ZFH-02056. Collectively, our work indicates that type 1 pili and QseC become critical in different infection stages, and that dual targeting of these factors has an additive effect on ablating UPEC virulence.
Unique Biological Activity of Botulinum D/C Mosaic Neurotoxin in Murine Species
Authors: Nakamura Keiji , Kohda Tomoko , Shibata Yuto , Tsukamoto Kentaro , Arimitsu Hideyuki , Hayashi Mitsunori , Mukamoto Masafumi , Sasakawa Nobuyuki , Kozaki Shunji
Published: June 2012

Clostridium botulinum
types C and D cause animal botulism by the production of serotype-specific or mosaic botulinum neurotoxin (BoNT). The D/C mosaic BoNT (BoNT/DC), which is produced by the isolate from bovine botulism in Japan, exhibits the highest toxicity to mice among all BoNTs. In contrast, rats appeared to be very resistant to BoNT/DC in type C and D BoNTs and their mosaic BoNTs. We attempted to characterize the enzymatic and receptor-binding activities of BoNT/DC by comparison with those of type C and D BoNTs (BoNT/C and BoNT/D). BoNT/DC and D showed similar toxic effects on cerebellar granule cells (CGCs) derived from the mouse, but the former showed less toxicity to rat CGCs. In recombinant murine-derived vesicle-associated membrane protein (VAMP), the enzymatic activities of both BoNTs to rat isoform 1 VAMP (VAMP1) were lower than those to the other VAMP homologues. We then examined the physiological significance of gangliosides as the binding components for types C and D, and mosaic BoNTs. BoNT/DC and C were found to cleave an intracellular substrate of PC12 cells upon the exogenous addition of GM1a and GT1b gangliosides, respectively, suggesting that each BoNT recognizes a different ganglioside moiety. The effect of BoNT/DC on glutamate release from CGCs was prevented by cholera toxin B-subunit (CTB) but not by a site-directed mutant of CTB that did not bind to GM1a. Bovine adrenal chromaffin cells appeared to be more sensitive to BoNT/DC than to BoNT/C and D. These results suggest that a unique mechanism of receptor binding of BoNT/DC may differentially regulate its biological activities in animals.
Staphylococcal Superantigen-Like Protein 3 Binds to the Toll-Like Receptor 2 Extracellular Domain and Inhibits Cytokine Production Induced by Staphylococcus aureus, Cell Wall Component, or Lipopeptides in Murine Macrophages
Authors: Yokoyama Ryosuke , Itoh Saotomo , Kamoshida Go , Takii Takemasa , Fujii Satoshi , Tsuji Tsutomu , Onozaki Kikuo
Published: June 2012

Staphylococcal superantigen-like proteins (SSLs) are a family of exoproteins sharing structural similarity with superantigens, but no superantigenic activity. Corresponding host target proteins or receptors against a portion of SSLs in the family have been identified. In this study, we show that SSL3 specifically binds to Toll-like receptor 2 (TLR2) and inhibits the stimulation of macrophages by TLR2 ligands. An approximately 100-kDa protein was recovered by using recombinant His-tagged SSL3-conjugated Sepharose from the lysate of porcine spleen, and the protein was identified as porcine TLR2 by peptide mass fingerprinting analysis. The SSL3-conjugated Sepharose recovered human and mouse TLR2 but not TLR4 from human neutrophils and mouse macrophage RAW 264.7 cells, as well as a recombinant TLR2 extracellular domain chimera protein. The production levels of interleukin 12 (IL-12) from mouse macrophages treated with heat-killedStaphylococcus aureusand of tumor necrosis factor alpha (TNF-α) from RAW 264.7 cells induced by peptidoglycan or lipopeptide TLR2 ligands were strongly suppressed in the presence of SSL3. The mutation of consensus sialic acid-containing glycan-binding residues in SSL3 did not abrogate the binding ability to TLR2 or inhibitory activity on TLR2, indicating that the interaction of SSL3 with TLR2 was independent of the sialic acid-containing glycan-binding residues. These findings demonstrate that SSL3 is able to bind the extracellular domain of TLR2 and interfere with TLR2 function. The present study provides a novel mechanism of SSL3 in immune evasion ofS. aureusvia interfering with its recognition by innate immune cells.
Alveolar Macrophages in Neonatal Mice Are Inherently Unresponsive to Pneumocystis murina Infection
Authors: Kurkjian Cathryn , Hollifield Melissa , Lines J. Louise , Rogosky Amy , Empey Kerry M. , Qureshi Mahboob , Brown Stephen A. , Garvy Beth A.
Published: June 2012

Pneumocystispneumonia was first diagnosed in malnourished children and has more recently been found in children with upper respiratory symptoms. We previously reported that there is a significant delay in the immune response in newborn mice infected withPneumocystiscompared to adults (Garvy BA, Harmsen AG, Infect. Immun. 64:3987–3992, 1996, and Garvy BA, Qureshi M, J. Immunol. 165:6480–6486, 2000). This delay is characterized by the failure of neonatal lungs to upregulate proinflammatory cytokines and attract T cells into the alveoli. Here, we report that regardless of the age at which we infected the mice, they failed to mount an inflammatory response in the alveolar spaces until they were 21 days of age or older. Anti-inflammatory cytokines had some role in dampening inflammation, since interleukin-10 (IL-10)-deficient pups clearedPneumocystisfaster than wild-type pups and the neutralization of transforming growth factor beta (TGF-β) with specific antibody enhanced T cell migration into the lungs at later time points. However, the clearance kinetics were similar to those of control pups, suggesting that there is an intrinsic deficiency in the ability of innate immunity to controlPneumocystis. We found, using an adoptive transfer strategy, that the lung environment contributes to association ofPneumocystisorganisms with alveolar macrophages, implying no intrinsic deficiency in the binding ofPneumocystisby neonatal macrophages. Using bothin vivoandin vitroassays, we found thatPneumocystisorganisms were less able to stimulate translocation of NF-κB to the nucleus of alveolar macrophages from neonatal mice. These data indicate that there is an early unresponsiveness of neonatal alveolar macrophages toPneumocystisinfection that is both intrinsic and related to the immunosuppressive environment found in neonatal lungs.