bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical Evaluation of Gas Turbine Blades Run 53,000 Hours After Repair
Authors: Pearman Stephen C. , Thiellier J. H. P.
Published: April 2015

This paper describes the complete evaluation of GE MS 5001 first stage turbine buckets run for 53,000 hours following repair and coating. The IN738 buckets were repaired and coated with a platinum aluminide coating1 in late 1977 and then run in base load operation by Akzo Zout Chemie. When the buckets were removed from service, several buckets were selected for evaluation, while the balance were again repaired and returned to service. Metallurgical and chemical analysis of the base metal and coating and mechanical property tests were conducted on an engine run part. These test results are reported as well as results on other engine run parts that have been subjected to a standard heat treatment or Hot Isostatic Pressing plus standard heat treatment prior to testing.
The Effect of Heat Transfer on Gas Turbine Transients
Authors: Pilidis P. , MacCallum N. R. L.
Published: April 2015

This paper describes how allowance for the thermal effects of non-adiabatic flow, altered boundary layer development, changes in tip clearances and changes in seal clearances have been incorporated into a general gas turbine transient program. These non-adiabatic effects have been investigated, modelling a two-spool bypass engine. The model has predicted events that occur in practice and also indicates which of the parameters are the most influential in the alteration of transient performance.
Small Gas Turbines for US Army Auxiliary Power Systems
Authors: Mercure Robert A.
Published: April 2015

Gas turbine driven Auxiliary Power Units (APU) have been used in both military and commercial aviation support systems for more than 30 years. APUs installed on-board aircraft provide electrical, hydraulic and pneumatic power to assist and support the vehicle and the main propulsion systems. Ground carts provide similiar functions for mission preparation and maintenance as well as mobile electric power. Other applications include tracked combat vehicles and ground shelter units.

The primary attributes of the gas turbine have given it a solid foothold in the aircraft APU market. Non-aviation applications, however, have been limited because of the turbine’s high acquisition cost and high fuel consumption relative to other available engines. Reducing specific fuel consumption is not as inherently valuable as reducing cost and increasing reliability since engine acquisition and maintenance costs of APUs dominate life cycle costs.
The AVCO-Lycoming TF15: A Regenerative Marine Gas Turbine
Authors: Lauriat T. B.
Published: April 2015

The paper will describe the engine and its derivation from the AGT1500 automotive gas turbine. Changes and variations of the AGT-1500 control system to accommodate the requirements of marine propulsion will be described. Some of the proposed propulsion system schemes will also be discussed.
The GTCP36-300, a Gas Turbine Auxiliary Power Unit for Advanced Technology Transport Aircraft
Authors: Stohlgren L. M. , Werner Lutz D.
Published: April 2015

The Garrett GTCP36-300 Series Auxiliary Power Unit is being developed for use on advanced technology transport aircraft in the 150-passenger size class. The first application will be the Airbus Industries A320 Aircraft. The APU uses a 6:1 pressure ratio, single-stage compressor and turbine, driving a single-stage load compressor and accessory gearbox. The 480 horsepower APU delivers compressed air to the aircraft pneumatic system and drives a customer furnished 90 kva, 24,000 rpm electrical generator. State-of-the-art aerodynamics, materials, and digital electronics are used to give the user-airlines an APU delivering maximum performance with minimum envelope, weight, and cost of ownership.
Experimental Investigations of a Gas Turbine as an Object of Speed and Temperature Control
Authors: Perycz S. , Dzida M.
Published: April 2015

The examinations of the stationary and frequency characteristics of the two-shaft aviation type gas turbine are described in this paper.
Simulation of the Heat Transfer in a Gas Turbine Combustor Fueled With Coal-Water Mixture: Part 1 — Model Development and Verification
Authors: Farag Ihab H. , Vaillancourt Joseph
Published: April 2015

It is possible to disperse high concentrations of finely pulverized beneficiated coal in water to produce a stable coal-water slurry fuel (CWF). One of the potential applications of CWF is as a fuel in gas turbines. This represents a relatively novel, developing technology. Coal beneficiation to the level needed for gas turbine application (< 1 percent ash) requires fine grinding of the coal particles to less than 15 μm necessitating increase in water content of the slurry to avoid increased CWS viscosity due to the finer particles. The gas turbine cycle is capable of accommodating an increased water content of the fuel without a significant loss in efficiency.

The objective of the present study is to develop and verify a computer model to simulate the heat transfer processes taking place in a gas turbine combustor (GTC) burning a CWF. The model predicts the species and the temperature distribution throughout the GTC, the heat flux patterns and the contribution of both convection and radiation to the total heat transfer rate.

Model verification includes cases of cold flow without combustion, combustion without heat release, combustion without convection and/or radiation, verification of exchange areas and an overall energy balance check.
Electricity From Coal: The British Gas/Lurgi Gasification for Combined Cycle Power Generation
Authors: Vierrath Helmut E. , Herbert Peter K. , Greil Claus F. , Thompson Brian H.
Published: April 2015

It is widely accepted that coal gasification combined-cycle plants represent an environmentally superior alternative to conventional coal fired power plants with flue gas desulfurization. Purpose of this paper is to show that technology is available for all steps required to convert coal to electricity, including treatment of waste streams. Based on examples for power plants in the 200–800 MW range using current and as well as advanced gas turbines, it is shown that under both European and US-conditions cost of electricity from this (new) route of coal based power generation is certainly no higher — and probably even lower — than from conventional PC (pulverized coal) power plants equipped with equivalent environmental control technology. Thus, this technology is likely to be a prime contributor when it comes to enhance environmental acceptability of power plants in general, and to help solve the acid rain problem in particular.

In addition the versatility of the proposed technology for repowering, decentralized application and district heat system is explained.
Calculation Procedure for Steam Injected Gas Turbine Cycles With Autonomous Distilled Water Production
Authors: Cerri Giovanni , Arsuffi Giacomo
Published: April 2015

Basic thermodynamic calculations of mixed gas-steam cycles combined with water distillation processes are covered in the paper.

The mixed gas-steam cycle is made up of a conventional gas turbine with a heat recovery section for producing the injected steam from high salinity water.

The heat recovery section is composed of a boiler and a water desalination plant and uses exhaust gas heat.

Water distillation stage number (SN) and total heat transfer area parameter (SR) are important for plant performance. Overall mixed cycle calculations are shown together with main results.

It is suggested that gas turbine manufacturers should design and develop combustion chambers and turbines for the gas-steam mixture flow to match the compressors available today and so enhance the performances which can be obtained from present gas-turbine technology.
Laser Cladding of Gas Turbine Components
Authors: Eboo G. M. , Blake A. G.
Published: April 2015

Using dynamic powder feed it is now possible to laser hardface many low grade metallic materials with high grade alloy, ceramic, and superalloy coatings. A wide variety of components from pump housings, turbine blades, oil field drilling equipment to automobile and construction equipment can be laser hardfaced with superior metallurgical results and cost savings. This paper examines laser dynamic powder feed technology applied to gas turbine and other industrial components.
Development of a New Hot Gas Double Axial Valve and Design Concept for a Coaxial Valve
Authors: Kruschik J.
Published: April 2015

The hot gas double axial valve is a newly developed shut-off valve for high temperature and high pressure helium, which can be used in the new generation of helium cooled nuclear plants, including the modular reactor. It is the safety shut-off valve in the secondary circuit after the heat-exchanger. At first it will be used in the German project PNP (nuclear process heat for the gasification of coal), but it can also be used for the other high temperature systems such as the closed cycle nuclear gas turbine, chemical plants or for industrial processes. Its state of development, test results, and the present prototype design are discussed.

A further concept for a coaxial valve will be shown, which may be of interest for certain types of modular reactors and also for closed cycle nuclear gas turbines.
Life Cycle Cost Methodology for Preliminary Design Evaluation
Authors: Reed Edward J.
Published: April 2015

A major portion of the Life Cycle Cost (LCC) of a modern high technology weapon system is determined by design decisions made very early in the development process. Many of these decisions affect the design so fundamentally that later changes become impractical. Although a computerized weapon system LCC methodology has been developed at Pratt & Whitney to evaluate engine trades, its complexity limits its usefulness during preliminary design when the largest number of decisions must be made. This paper describes a technique used to provide a simplified version of this methodology to design engineers to conduct configuration/cost/performance trades. By supplying the designer with a simple, effective evaluation tool, LCC becomes an integral part of the design system from the beginning.
Validation of Viscous and Inviscid Computational Methods for Turbomachinery Components
Authors: Povinelli Louis A.
Published: April 2015

An assessment of several three-dimensional computer codes used at the NASA Lewis Research Center is presented. Four flow situations are examined, for which both experimental data and computational results are available. The four flows form a basis for the evaluation of the computational procedures. It was concluded that transonic rotor flow at peak efficiency conditions may be calculated with a reasonable degree of accuracy, whereas, off-design conditions are not accurately determined. Duct flows and turbine cascade flows may also be computed with reasonable accuracy whereas radial inflow turbine flow remains a challenging problem.
Correlation of Structural Ceramic Time Dependent Failure Data
Authors: Swank Lewis R.
Published: April 2015

Today there is a rapidly growing interest in the use of ceramics for structural applications. In applying structural ceramics it is necessary to estimate the time dependent failure behavior of the material. An analytical method is required to utilize flexural fast fracture and stress rupture data to predict the time dependent behavior of complex structures. This paper proposes an empirical equation to correlate the data. The proposed equation is applied to flexural and spin disk data. The flexural data correlate reasonably well. The spin disk data correlate well if the assumption is made that the stress in the flexural stress rupture specimens of the data base are those of steady state creep.
Steam Injected Gas Turbine Integrated With a Self-Production Demineralized Water Thermal Plant
Authors: Cerri Giovanni , Arsuffi Giacomo
Published: April 2015

A simple steam injected gas turbine cycle equipped with an exhaust heat recovery section is analyzed. The heat recovery section consists of a waste heat boiler which produces the steam to be injected into the combustion chamber and a self-production demineralized water plant based on a distillation process. This plant supplies the pure water needed in the mixed steam-gas cycle.

Desalination plant requirements are investigated and heat consumption for producing distilled water is given.

Overall steam-gas turbine cycle performance and feasibility of desalting plants are investigated in a firing temperature range from 1000.°C to 1400.°C for various compressor pressure and steam-to-air injection ratios. An example is reported.
Turbulence Measurements in a Straight Walled Two Dimensional Diffuser
Authors: Mobarak A. , Fouad M. A. , Metwally M. A.
Published: April 2015

Turbulent flow field of a straight walled two dimensional diffuser Is experimentally studied using a hot wire anemometer (X-probe type). The diffuser flow Is tested at the optimum angle corresponding to maximum pressure recovery and consequently at conditions of attached flow. Diffuser side walls are made of different materials to study the effect of wall roughness. Measurements of static pressure, flow velocity, turbulence intensity and turbulent shear stress are carried out at six cross-sections distributed along the axial length of the diffuser. At each cross-section measurements were taken at nine planes distributed along the diffuser width between the parallel walls. Variations of boundary layer displacement thicknesses are studied through their relations to turbulence intensity. The present detailed experimental results are intended as an input to a turbulence model for prediction of diffuser flow.
Shock-Expansion Wave Engines — New Directions for Power Production
Authors: Weber H. E.
Published: April 2015

For decades large amounts of money and effort have been spent on conventional turbomachinery development. Initially improvements in performance were rapid. However, in the last two decades better performance of these machines has slowed considerably. Compressor efficiencies have been near their present limits of 88% to 92% for many years. High pressure ratios required of high performance engines are not efficiently produced in the conventional turbomachines. High pressure ratios for high cycle efficiency require many stages of conventional compression. Compressors, especially in small turbomachines, decrease in efficiency as the number of stages increase due to the large amounts of surface area and relatively large leakage passages in the higher pressure stages.

The requirement for many stages of conventional compression also results in heavy machines. If high compressor pressure cannot be attained the turbine exhaust gas temperature may be considerably above the compressor discharge temperature; a regenerator or recuperator is then required for acceptable cycle efficiency. This results in considerable complication and high engine weight.

Maximum turbine inlet temperatures in conventional machines have also been near their limit for many years. High temperatures and high pressures required for light weight, high efficiency machines are inconsistent with the requirements for high strength materials. To increase permissable turbine inlet temperatures compressor discharge air is used for blade cooling. Use of this air soon reaches its limit because the high pressure cooling air is then not available for power production. Engine power and cycle efficiency begins to decrease and a limit on turbine inlet temperature results.

Consequently, new concepts in power and thrust production are required. One class of machines which may alleviate many of the above described problems are the wave rotors or engines (1 thru 15). These operate with time dependent flow in the moving rotor blade passages and steady flow in the stator parts.
Determination of Convective Diffusion Heat/Mass Transfer Rates to Burner Rig Test Targets Comparable in Size to Cross-Stream Jet Diameter
Authors: Gökoğlu Süleyman A. , Santoro Gilbert J.
Published: April 2015

Two sets of experiments have been performed to be able to predict the convective diffusion heat/mass transfer rates to a cylindrical target whose height and diameter are comparable to, but less than, the diameter of the circular cross-stream jet, thereby simulating the same geometric configuration as a typical burner rig test specimen located in the cross-stream of the combustor exit nozzle. The first set exploits the naphthalene sublimation technique to determine the heat/mass transfer coefficient under isothermal conditions for various flow rates (Reynolds numbers). The second set, conducted at various combustion temperatures and Reynolds numbers, utilizes the temperature variation along the surface of the above-mentioned target under steady-state conditions to estimate the effect of cooling (dilution) due to the entrainment of stagnant room temperature air. The experimental information obtained is used to predict high temperature, high velocity corrosive salt vapor deposition rates in burner rigs on collectors that are geometrically the same. The agreement with preliminary data obtained from Na2S04 vapor deposition experiments is found to be excellent.
Selective Catalytic Reduction Impact on Heat Recovery Steam Generator Design and Operation
Authors: Davis James S. , Duponteil G. C.
Published: April 2015

Selective Catalytic Reduction (SCR) is a post-combustion method to reduce the oxides of nitrogen (NOx), present in flue gases such as gas turbine exhaust streams, to N2 and water. It involves the injection of ammonia and the use of a catalyst module to promote the reaction to obtain high efficiency (60–86+%) NOx reduction.

Several operating parameters can influence catalyst performance to include temperature, gas flow distribution, presence of sulfur compounds and catalyst age. This paper examines the impact of a SCR integration in a gas turbine heat recovery steam generator (HRSG) design/operation. Limitations on HRSG load and following capabilities, effect on capital cost and overall performance and current SCR system experience represent a number of areas that are examined.
Analysis and Optimization of a Compressed Air Energy Storage System in Aquifer
Authors: Vadasz Peter , Weiner Dan
Published: April 2015

This paper discusses the thermo-economic analysis and optimization of a constant pressure Compressed Air Energy Storage system, in aquifer, subjected to an exogenous, periodic electricity price function of the interconnection. The target function considered is the net benefit of the plant. It is related to the fundamental planning parameters of the system like the compressor pressure ratio, the maximum temperature ratio, the charging-discharging duration ratio and the plant capacity factor. The results of the analysis permit to obtain the optimal values of the fundamental parameters to be used in the planning process.
Ni-induced graphitization for enhanced long-term stability of ohmic contact to polycrystalline 3C-SiC
Authors: Chen Shuo , Luna Lunet E. , You Zheng , Carraro Carlo , Maboudian Roya
Published: April 2015

Stable metal contacts for SiC-based devices are required for high temperature microelectronics and microsensor devices. Ni-induced nanocrystalline graphitic carbon is introduced between Pt/Ti and n-type polycrystalline 3C-SiC as a means of forming contacts that are stable at high temperature. With the addition of an alumina protection layer, this metallization scheme is further improved and can maintain low contact resistivity after 500 h at 450 °C in air. The role of the graphitic layer in both the formation and long-term stability of the contact is investigated. Although the formation of an ohmic contact between Pt/Ti and polycrystalline 3C-SiC does not require the graphitic carbon, this interfacial layer is necessary for maintaining low contact resistivity during long-term exposure to elevated temperature.
Investigating the effect of thermal annealing on dc performance of off-state drain-voltage step-stressed AlGaN/GaN high electron mobility transistors
Authors: Kim Byung-Jae , Ahn Shihyun , Hwang Ya-Hsi , Ren Fan , Pearton Stephen J. , Kim Jihyun , Zhang Ming-Lan
Published: April 2015

The effects of a thermal annealing process on the dc performance of off-state, drain-voltage step-stressed AlGaN/GaN high electron mobility transistors (HEMTs) were investigated. After stress, the reverse bias gate leakage current increased from 7 × 10−3 to 1.96 × 10−1 mA/mm and drain current on–off ratio decreased from 1.9 × 105 to 4.52 × 103. These degradations were completely recovered after a thermal annealing at 450 °C for 10 min. Temperature-dependent drain-current subthreshold swing measurements were employed to estimate the trap densities located in the AlGaN barrier layer near-surface region of the HEMTs before and after off-state drain-voltage step-stressing and also following subsequent thermal annealing. Off-state step-stressing produced a significant increase of trap density from 2.15 × 1012 to 1.63 × 1013/cm2 V. This was reduced to 5.21 × 1012/cm2 V after thermal annealing. These results show that simple thermal annealing can recover much of the degradation caused by step-stressing below the threshold for permanent damage.
Ebola and beyond
Authors: Lipsitch Marc , Eyal Nir , Halloran M. Elizabeth , Hernán Miguel A. , Longini Ira M. , Perencevich Eli N. , Grais Rebecca F.
Published: April 2015

Recent experiences in confronting the Ebola epidemic suggest principles for vaccine efficacy trials in challenging environments
Neoantigens in cancer immunotherapy
Authors: Schumacher Ton N. , Schreiber Robert D.
Published: April 2015

The clinical relevance of T cells in the control of a diverse set of human cancers is now beyond doubt. However, the nature of the antigens that allow the immune system to distinguish cancer cells from noncancer cells has long remained obscure. Recent technological innovations have made it possible to dissect the immune response to patient-specific neoantigens that arise as a consequence of tumor-specific mutations, and emerging data suggest that recognition of such neoantigens is a major factor in the activity of clinical immunotherapies. These observations indicate that neoantigen load may form a biomarker in cancer immunotherapy and provide an incentive for the development of novel therapeutic approaches that selectively enhance T cell reactivity against this class of antigens.
T cell exclusion, immune privilege, and the tumor microenvironment
Authors: Joyce Johanna A. , Fearon Douglas T.
Published: April 2015

Effective immunotherapy promotes the killing of cancer cells by cytotoxic T cells. This requires not only that cancer-specific T cells be generated, but also that these T cells physically contact cancer cells. The coexistence in some patients of cancer cells and T cells that recognize them indicates that tumors may exhibit the phenomenon of immune privilege, in which immunogenic tissue is protected from immune attack. Here, we review the evidence that stromal cells of the tumor microenvironment mediate this restriction by excluding T cells from the vicinity of cancer cells. Overcoming this T cell checkpoint may thus enable optimal immunotherapy.
Observing the onset of outflow collimation in a massive protostar
Authors: Carrasco-González C. , Torrelles J. M. , Cantó J. , Curiel S. , Surcis G. , Vlemmings W. H. T. , van Langevelde H. J. , Goddi C. , Anglada G. , Kim S.-W. , Kim J.-S. , Gómez J. F.
Published: April 2015

Young stars grow up and narrow their focus

Stars are thought to grow by gathering spirals of material from a disk. If this is the case, to balance angular momentum, gas should flow out rapidly along the disk's rotation axis. Carrasco-Gonzalez
et al.
now seem to have glimpsed the “before” and “after” stages of the onset of such an outflow, over the course of just 18 years (see the Perspective by Hoare). Radio monitoring of the massive protostar W75N(B)-VLA2 reveals a transition from a spherical wind to a collimated one, giving critical insight into what happens as a massive star forms.

Science
, this issue p.
114
; see also p.
44
Defining the epoch we live in
Authors: Ruddiman William F. , Ellis Erle C. , Kaplan Jed O. , Fuller Dorian Q.
Published: April 2015

Is a formally designated “Anthropocene” a good idea?
Development and Application of a gp60-Based Typing Assay for Cryptosporidium viatorum
Authors: Stensvold C. R. , Elwin K. , Winiecka-Krusnell J. , Chalmers R. M. , Xiao L. , Lebbad M.
Published: April 2015

The apicomplexan intestinal parasites of the genus
Cryptosporidium
take a major toll on human and animal health and are frequent causes of waterborne outbreaks. Several species and genotypes can infect humans, including
Cryptosporidium viatorum
, which, to date, has only been found in humans. Molecular characterization of
Cryptosporidium
spp., critical to epidemiological analyses, is commonly based on gp60 gene analysis, which appears to require bespoke species- or group-specific PCR primers due to extensive genetic diversity across the genus. In this study, we amplified, sequenced, and characterized the gp60 gene of
C. viatorum
for the first time. Moreover, we developed and validated a gp60 typing assay for this species and applied it to 27 isolates originating from Asia, Africa, and Central America. A single subtype family, XVa, was identified containing multiple alleles.
First Case Report of Campylobacter volucris Bacteremia in an Immunocompromised Patient
Authors: Kweon Oh Joo , Lim Yong Kwan , Yoo Byeongpil , Kim Hye Ryoun , Kim Tae-Hyoung , Lee Mi-Kyung
Published: April 2015

We report a case of
Campylobacter volucris
bacteremia in an immunocompromised patient with polycythemia vera and alcoholic liver cirrhosis. To our knowledge, this is the first case report in which this organism has been isolated from a human clinical specimen.
Simian Immunodeficiency Virus SIVsab Infection of Rhesus Macaques as a Model of Complete Immunological Suppression with Persistent Reservoirs of Replication-Competent Virus: Implications for Cure Research
Authors: Ma Dongzhu , Xu Cuiling , Cillo Anthony R. , Policicchio Benjamin , Kristoff Jan , Haret-Richter George , Mellors John W. , Pandrea Ivona , Apetrei Cristian
Published: April 2015

Simian immunodeficiency virus SIVsab infection is completely controlled in rhesus macaques (RMs) through functional immune responses. We report that in SIVsab-infected RMs, (i) viral replication is controlled to <0 to 3 copies/ml, (ii) about one-third of the virus strains in reservoirs are replication incompetent, and (iii) rebounding virus after CD8
+
cell depletion is replication competent and genetically similar to the original virus stock, suggesting early reservoir seeding. This model permits assessment of strategies aimed at depleting the reservoir without multidrug antiretroviral therapy.
Crystal Structures of Yeast-Produced Enterovirus 71 and Enterovirus 71/Coxsackievirus A16 Chimeric Virus-Like Particles Provide the Structural Basis for Novel Vaccine Design against Hand-Foot-and-Mouth Disease
Authors: Lyu Ke , He Ya-Ling , Li Hao-Yang , Chen Rong
Published: April 2015

Human enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the two major causative agents for hand-foot-and-mouth disease (HFMD). Previously, we demonstrated that a virus-like particle (VLP) for EV71 produced from
Saccharomyces cerevisiae
is a potential vaccine candidate against EV71 infection, and an EV71/CVA16 chimeric VLP can elicit protective immune responses against both virus infections. Here, we presented the crystal structures of both VLPs, showing that both the linear and conformational neutralization epitopes identified in EV71 are mostly preserved on both VLPs. The replacement of only 4 residues in the VP1 GH loop converted strongly negatively charged surface patches formed by portions of the SP70 epitope in EV71 VLP into a relatively neutral surface in the chimeric VLP, which likely accounted for the additional neutralization capability of the chimeric VLP against CVA16 infection. Such local variations in the amino acid sequences and the surface charge potential are also present in different types of polioviruses. In comparison to EV71 VLP, the chimeric VLP exhibits structural changes at the local site of amino acid replacement and the surface loops of all capsid proteins. This is consistent with the observation that the VP1 GH loop located near the pseudo-3-fold junction is involved in extensive interactions with other capsid regions. Furthermore, portions of VP0 and VP1 in EV71 VLP are at least transiently exposed, revealing the structural flexibility of the VLP. Together, our structural analysis provided insights into the structural basis of enterovirus neutralization and novel vaccine design against HFMD and other enterovirus-associated diseases.

IMPORTANCE
Our previous studies demonstrated that the enterovirus 71 (EV71) virus-like particle (VLP) produced from yeast is a vaccine candidate against EV71 infection and that a chimeric EV71/coxsackievirus A16 (CVA16) VLP with the replacement of 4 amino acids in the VP1 GH loop can confer protection against both EV71 and CVA16 infections. This study reported the crystal structures of both the EV71 VLP and the chimeric EV71/CVA16 VLP and revealed that the major neutralization epitopes of EV71 are mostly preserved in both VLPs. In addition, the mutated VP1 GH loop in the chimeric VLP is well exposed on the particle surface and exhibits a surface charge potential different from that contributed by the original VP1 GH loop in EV71 VLP. Together, this study provided insights into the structural basis of enterovirus neutralization and evidence that the yeast-produced VLPs can be developed into novel vaccines against hand-foot-and-mouth disease (HFMD) and other enterovirus-associated diseases.
Regulation of Bacterial Virulence by Csr (Rsm) Systems
Authors: Vakulskas Christopher A. , Potts Anastasia H. , Babitzke Paul , Ahmer Brian M. M. , Romeo Tony
Published: April 2015

Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5′ untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens.
Eosinophilic ulcer of the tongue: a rare and confusing clinical entity
Authors: Lingaraju Naresh , Besagarahally Gaddelingiah Yogesh , Shivalingu Mahesh Mysore , Khanum Nishath
Published: April 2015

Eosinophilic ulcers are rare, benign, reactive and often self-limiting lesions of the oral cavity. Although the aetiology is not clear, trauma is believed to play a role in their development. Clinically, the lesion manifests as an isolated ulcer, with raised, indurated borders and a yellow fibrinous floor; because of its long duration it often leads to the suspicion of squamous cell carcinoma. Although the ulcer is benign in nature, a biopsy is necessary to rule out malignancy. Histopathologically, the ulcer is characterised by the presence of dense inflammatory infiltrate extending into the deeper muscle layers with sheets of lymphocytes intermixed with eosinophils. This is a case report of a 65-year-old woman with an eosinophilic ulcer on the lateral border of the tongue. The ulcer healed rapidly after an incisional biopsy and topical steroid application. The final diagnosis was achieved following clinical and histopathological examination.
A novel antidoping and medical care delivery model at the 2nd Summer Youth Olympic Games (2014), Nanjing China
Authors: Mountjoy Margo , Akef Najla , Budgett Richard , Greinig Susan , Li Guoping , Manikavasagam Jegathesan , Soligard Torbjorn , Haiming Xai , Yang Xiaoye
Published: April 2015

Background

Antidoping and medical care delivery programmes are required at all large international multisport events.

Objective

To document and critique the novel antidoping and medical care delivery models implemented at the 2nd Summer Youth Olympic Games, Nanjing 2014.

Methods

The International Olympic Committee implemented two new models of delivery of antidoping and medical care at the YOG. A review of these models as well as the public health programme and two health educational initiatives in the Cultural and Educational Program was undertaken by the International Olympic Committee.

Results

The implementation of the new antidoping model was feasible in the setting of the YOG. The antidoping rules and regulations of the International Olympic Committee were respected. This model enhanced the educational initiative and provided financial as well as human resource savings. The execution of the hospital-based venue model of medical care delivery at the YOG was also feasible in this setting. This model provided a practical infrastructure for the delivery of medical care at multisport events with the goal of providing optimum athlete healthcare. A public health prevention programme was implemented and no public health risks were encountered by the participants or the Nanjing citizens during the YOG. Finally, the implementation of the athlete health educational programmes within the Cultural and Educational Program provided athletes with an opportunity to improve their health and performance.

Conclusions

To achieve the goal of protecting athlete health, and of employing effective doping control and education, new alternate models of antidoping and medical care delivery can be implemented.
Pharmacist-led management of chronic pain in primary care: costs and benefits in a pilot randomised controlled trial
Authors: Neilson Aileen R , Bruhn Hanne , Bond Christine M , Elliott Alison M , Smith Blair H , Hannaford Philip C , Holland Richard , Lee Amanda J , Watson Margaret , Wright David , McNamee Paul
Published: April 2015

Objectives

To explore differences in mean costs (from a UK National Health Service perspective) and effects of pharmacist-led management of chronic pain in primary care evaluated in a pilot randomised controlled trial (RCT), and to estimate optimal sample size for a definitive RCT.

Design

Regression analysis of costs and effects, using intention-to-treat and expected value of sample information analysis (EVSI).

Setting

Six general practices: Grampian (3); East Anglia (3).

Participants

125 patients with complete resource use and short form-six-dimension questionnaire (SF-6D) data at baseline, 3 months and 6 months.

Interventions

Patients were randomised to either pharmacist medication review with face-to-face pharmacist prescribing or pharmacist medication review with feedback to general practitioner or treatment as usual (TAU).

Main outcome measures

Differences in mean total costs and effects measured as quality-adjusted life years (QALYs) at 6 months and EVSI for sample size calculation.

Results

Unadjusted total mean costs per patient were £452 for prescribing (SD: £466), £570 for review (SD: £527) and £668 for TAU (SD: £1333). After controlling for baseline costs, the adjusted mean cost differences per patient relative to TAU were £77 for prescribing (95% CI −82 to 237) and £54 for review (95% CI −103 to 212). Unadjusted mean QALYs were 0.3213 for prescribing (SD: 0.0659), 0.3161 for review (SD: 0.0684) and 0.3079 for TAU (SD: 0.0606). Relative to TAU, the adjusted mean differences were 0.0069 for prescribing (95% CI −0.0091 to 0.0229) and 0.0097 for review (95% CI −0.0054 to 0.0248). The EVSI suggested the optimal future trial size was between 460 and 690, and between 540 and 780 patients per arm using a threshold of £30 000 and £20 000 per QALY gained, respectively.

Conclusions

Compared with TAU, pharmacist-led interventions for chronic pain appear more costly and provide similar QALYs. However, these estimates are imprecise due to the small size of the pilot trial. The EVSI indicates that a larger trial is necessary to obtain more precise estimates of differences in mean effects and costs between treatment groups.

Trial registration number

ISRCTN06131530.
Measuring client satisfaction
Authors: Bains Bal
Published: April 2015

Customer satisfaction and loyalty are essential for retaining pet owners and running a profitable veterinary practice. However, without proper survey methods it can be difficult to obtain accurate client feedback. Bal Bains discusses different ways of finding out how clients rate a practice and how that information can be used to advantage. He also discusses some of the results from practice survey data collected by the Zoetis business consulting team.
Renal diets in cats with chronic kidney disease
Authors: Dean Rachel , Downes Martin
Published: April 2015

BestBETs for Vets are generated by the Centre for Evidence‐based Veterinary Medicine at the University of Nottingham to help answer specific questions and assist in clinical decision making. Although evidence is often limited, they aim to find, present and draw conclusions from the best available evidence, using a standardised framework. A more detailed description of how BestBETs for Vets are produced is published on pp 354‐356 of this issue of Veterinary Record
Learning in the third dimension
Authors: Boyd Sharon , Clarkson Eoghan , Mather Brian
Published: April 2015

Sharon Boyd, Eoghan Clarkson and Brian Mather explain how the Royal (Dick) School of Veterinary Studies is using the latest 3D modelling techniques to help students develop their clinical skills
The effects of cranial cooling during recovery on subsequent uncompensable heat stress tolerance
Authors: Wallace Phillip J. , Masbou Anaïs T. , Petersen Stewart R. , Cheung Stephen S.
Published: April 2015

This study compared cranial (CC) with passive (CON) cooling during recovery on tolerance to subsequent exercise while wearing firefighting protective ensemble and self-contained breathing apparatus in a hot-humid environment. Eleven males (mean ± SD; age, 30.9 ± 9.2 years; peak oxygen consumption, 49.5 ± 5.1 mL·kg−1·min−1) performed 2 × 20 min treadmill walks (5.6 km·h−1, 4% incline) in 35 °C and 60% relative humidity. During a 20-min recovery (rest), participants sat and removed gloves, helmets, and flash hoods but otherwise remained encapsulated. A close-fitting liquid-perfused hood pumped 13 °C water at ∼500 mL·min−1through the head and neck (CC) or no cooling hood was worn (CON). During rest, neck temperature was lower in CC compared with CON from 4 min (CC: 35.73 ± 3.28 °C, CON: 37.66 ± 1.35 °C, p = 0.025) until the end (CC: 33.06 ± 4.70 °C, CON: 36.85 ± 1.63 °C, p = 0.014). Rectal temperature rose in both CC (0.11 ± 0.19 °C) and CON (0.26 ± 0.15 °C) during rest, with nonsignificant interaction between conditions (p = 0.076). Perceived thermal stress was lower (p = 0.006) from 5 min of CC (median: 3 (quartile 1: 3, quartile 3: 4)) until the end of rest compared with CON (median: 4 (quartile 1: 4, quartile 3: 4)). However, there were no significant differences (p = 0.906) in tolerance times during the second exercise between CC (16.55 ± 1.14 min) and CON (16.60 ± 1.31 min), nor were there any difference in rectal temperature at the start (CC: 38.30 ± 0.40 °C, CON: 38.40 ± 0.16 °C, p = 0.496) or at the end (CC: 38.82 ± 0.23 °C, CON: 39.07 ± 0.22 °C, p = 0.173). With high ambient heat and encapsulation, cranial and neck cooling during recovery decreases physiological strain and perceived thermal stress, but is ineffective in improving subsequent uncompensable heat stress tolerance.
Fishing suitability maps: helping fishermen reduce discards
Authors: Vilela Raúl , Bellido Jose María
Published: April 2015

Discards poses a serious problem for the productivity and sustainability of European fisheries and thus is an important fisheries and ecological management issue to be solved. In this paper we present a statistical tool, based on the random forest technique, that aims to reduce the negative ecological impact of fishing by providing fishermen with near-real-time maps of a fishing suitability index based on haul-by-haul catch and discard rates, indicating the most suitable areas for fishing. These easy-to-interpret maps are to be accessible to users via an online geoportal. Observer data from the Spanish discard sampling program from 2004 to 2008 for several species caught in the Cantabrian Sea (ICES area VIIIc) were used to illustrate the random forest approach. Results in the case study varied among species and seasons, with better results achieved for balanced datasets, such as those for economically valuable target species with segregated life stages. We discuss how this online tool could be useful for fisheries management, particularly in the context of the European Common Fisheries Policy reform and the discard ban on commercial species.
Telmisartan reduces atrial arrhythmia susceptibility through the regulation of RAS–ERK and PI3K–Akt–eNOS pathways in spontaneously hypertensive rats
Authors: Wang Wei-wei , Zhang Fei-long , Chen Jian-hua , Chen Xue-hai , Fu Fa-yuan , Tang Mi-rong , Chen Liang-long
Published: April 2015

Telmisartan is an angiotensin II receptor blocker that displays unique PPAR-γ modulating activity. PPAR-γ agonists have been shown to decrease susceptibility to atrial fibrillation through their antioxidant and antiapoptotic effects. The aim of this study was to determine whether telmisartan would have a greater effect on susceptibility to atrial arrhythmia in a hypertensive rat model than valsartan, which is a traditional angiotensin II receptor blocker. In this study, spontaneously hypertensive rats were treated with 10 mg·(kg body mass)–1·d–1telmisartan (TEL group), 10 mg·(kg body mass)–1·d–1valsartan (VAL group), or vehicle (saline; SHR group) for 4 weeks. Age-matched Wistar–Kyoto rats (WKY) were used as normotensive controls. After 4 weeks of treatment, we performed echocardiographic assessment, electrophysiological analysis, histological evaluation, and Western blot analysis. Telmisartan decreased systolic blood pressure to a similar extent as valsartan. Relative to the WKY controls, atrial arrhythmia susceptibility was significantly increased in the SHR group, and was significantly decreased by both telmisartan and valsartan, albeit to a greater extent with telmisartan. Arrhythmogenic atrial remodeling, including enlargement of the left atrium, myocyte hypertrophy, interstitial fibrosis, and myocyte apoptosis, was observed in the SHR group, and was accompanied by activated RAS–ERK signaling and suppressed PI3K–Akt–eNOS signaling. The results suggest that telmisartan reduced susceptibility to atrial arrhythmia to a greater extent than valsartan, ameliorated atrial remodeling, and reversed imbalances in the RAS–ERK and PI3K–Akt–eNOS pathways.
Endogenous adenosine release is involved in the control of heart rate in rats
Authors: Jammes Yves , Joulia Fabrice , Steinberg Jean Guillaume , Ravailhe Sylvie , Delpierre Stéphane , Condo Jocelyne , Guieu Regis , Delliaux Stéphane
Published: April 2015

Intravenous (i.v.) injections of adenosine exert marked effects on heart rate (HR) and arterial blood pressure (BP), but the role of an endogenous adenosine release by vagal stimulation has not been evaluated. In anaesthetized rats, we examined HR and BP changes induced by 1 min electrical vagal stimulation in the control condition, and then after i.v. injections of (i) atropine, (ii) propranolol, (iii) caffeine, (iv) 8 cyclopentyl-1,3-dipropylxanthine (DPCPX), or (v) dipyridamole to increase the plasma concentration of adenosine (APC). APC was measured by chromatography in the arterial blood before and at the end of vagal stimulation. The decrease in HR in the controls during vagal stimulation was markedly attenuated, but persisted after i.v. injections of atropine and propranolol. When first administered, DPCPX modestly but significantly reduced the HR response to vagal stimulation, but this disappeared after i.v. caffeine administration. Both the HR and BP responses were significantly accentuated after i.v. injection of dipyridamole. Vagal stimulation induced a significant increase in APC, proportional to the magnitude of HR decrease. Our data suggest that the inhibitory effects of electrical vagal stimulations on HR and BP were partly mediated through the activation of A1 and A2 receptors by an endogenous adenosine release. Our experimental data could help to understand the effects of ischemic preconditioning, which are partially mediated by adenosine.
Self-interacting mass-dimension one fields for any spin
Authors: Lee Cheng-Yang
Published: April 2015

According to Ahluwalia and Grumiller, massive spin-half fields of mass-dimension one can be constructed using the eigenspinors of the charge-conjugation operator (Elko) as expansion coefficients. In this paper, we generalize their result by constructing quantum fields from higher-spin Elko. The kinematics of these fields are thoroughly investigated. Starting with the field operators, their propagators and Hamiltonians are derived. These fields satisfy the higher-spin generalization of the Klein–Gordon but not the Dirac equation. Independent of the spin, they are all of mass-dimension one and are thus endowed with renormalizable self-interactions. These fields violate Lorentz symmetry. The violation can be characterized by a non-Lorentz-covariant term that appears in the Elko spin-sums. This term provides a decomposition of the generalized higher-spin Dirac operator in the momentum space thus suggesting a possible connection between the mass-dimension one fields and the Lorentz-invariant fields.
A study on the effect of halloysite nanoparticle addition on the strength of glass fiber reinforced plastic
Authors: Kim Yun-Hae , Park Soo-Jeong , Lee Jin-Woo , Moon Kyung-Man
Published: April 2015

Halloysite nanotube, which has been used in the polymer, has been spotlighted as a useful functional materials in the improvement of mechanical properties. In the current study, we established the optimal nanoparticle dispersion and analyzed the mechanical characteristics and the behavior of composites reinforced by HNTs have been synthesized by dispersing HNTs to the unsaturated polyester resin (UPR) and their mechanical characteristics, especially the tensile strength, interlaminar shear strength have been analyzed. Additionally, the reinforcement effect and its variation according to the amount of HNTs was also studied.
Failure strain prediction of an arctic class marine steel (EH36) in average stress triaxiality regime
Authors: Choung Joonmo , Yoon Sung-Won , Park Sung-Ju
Published: April 2015

This paper introduces a procedure to predict failure strain for an arctic class marine structural steel, EH36. Based on previous results,1-4 this paper explains formulation procedure for a failure strain curve of the EH36 in medium-low and high average stress triaxiality zones by performing tensile tests for round and flat specimens with various notches. Verification of the validity of the failure strain envelope using user-defined subroutine imbedded in commercial finite element code Abaqus/Explicit is also described. The failure strain envelope provides relatively accurate simulation results by comparing tensile test results of asymmetric notch structures with fracture simulations using the user-defined subroutine.