bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced Small Modular Reactor Probabilistic Risk Assessment Framework
Authors: Smith Curtis
Published: July 2014

A key area of the Small Modular Reactor (SMR) Probabilistic Risk Assessment (PRA) use is in the development of methodologies and tools that will be used to predict the safety, security, safeguards, performance, and deployment viability of SMR systems starting in the design process through the operation phase. Recently, the Idaho National Laboratory (INL) set out to develop quantitative methods and tools and the associated analysis framework for assessing a variety of SMR risks. Development and implementation of SMR-focused safety assessment methods may require new analytic methods or adaptation of traditional methods to the advanced design and operational features of SMRs. The development of SMR-specific safety models for margin determination will provide a safety case that describes potential accidents, design options (including postulated controls), and supports licensing activities by providing a technical basis for the safety envelope. INL has proposed an approach to expand and advance the state-of-the-practice in PRA. Specifically we will develop a framework for applying modern computational tools to create advanced risk-based methods for identifying design vulnerabilities in SMRs. This framework will require the fusion of state-of-the-art PRA methods, advanced 3D visualization methods, and highperformance optimization. The approach has several defining attributes focused within three general areas:

1. Models – A single 3D representation of all key systems, structures, and components (SSCs) will be defined for a particular facility. We will be able to simulate — by understanding how each SSC interacts with other parts of the facility — the hazard-induced susceptibilities of each SSC.

2. Phenomena – An approach to effectively representing hazards and their effect on physical behavior at a facility will need to be determined. In many cases, multiple models of a specific phenomenon may be available, but this ensemble of models will need to be intelligently managed.

3. Integration – Any advanced risk-informed decision support approach will rely on a variety of probabilistic and mechanistic information. The safety, security, and economic drivers will need to be integrated in order to determine the effectiveness of proposed mitigation strategies. We will need to be able to manage all (important) hazards for all (important) scenarios all of the time the facility is in operation.

The focus of the paper will be on discussing the features of the proposed advanced SMR PRA Framework and providing an status update of the development activities.
The Mitsubishi Small Module High Temperature Gas-Cooled Reactor “MHR-50/100is” — Present Design Status and Its Prospect for Commercialization
Authors: Minatsuki Isao , Mizokami Yorikata , Kunitomi Kazuhiko
Published: July 2014

Mitsubishi Heavy Industries, Ltd. (MHI) has been carrying on development of a SMR for global strategic business and a conceptual design study of HTGR, namely MHR-50/100is having a high inherent safety and a high economical advantage for commercialization with supporting by Japan Atomic Energy Agency (JAEA). To begin with, a design philosophy of the MHR-50/100is had been set and the next phase, a conceptual design including plant dynamics analysis to investigate operational function and plant controllable performance had been carried out. It has been improved to establish higher safety level to meet the safety requirements after TEPCO’s Fukushima Daiichi Accident on March 11, 2011 in Japan.

A market research and a financial analysis to review a feasibility of nuclear business have been studied. Consequently, it has concluded that the large market and the business potential will be prospected. We envisioned that it is effective for acceleration of MHR-50/100is utilization to show wider application of the nuclear energy in general industry as well as electricity generation. In the study cooperative with these users, we have studied on a practical applicability of MHR-50/100is in a typical general industry. A concept of the heat utilization plant consisting of the MHR-50/100is and hydrogen production plant has been developed; a safety concern has been evaluated. This paper reports a summary of a series of the conceptual design studies, and the various evaluation analyses in which we investigated a technical feasibility and a business potential of MHR-50/100is.
Changes to Sustainability of Uranium Carbide Fuel for a Long-Burn Fast Reactor Core
Authors: Choi Hangbok , Stone Joshua
Published: July 2014

Advanced reactor concepts such as Generation-IV (Gen-IV) have been studied to fulfill the ambitious long term goals of developing a safe, sustainable, reliable, proliferation-resistant and economic nuclear energy system. The gas-cooled fast reactor (GFR) is a Gen-IV candidate for which a carbide fuel (UC, (U,Pu)C, ThC) has desirable properties in a fuel system using ceramic (SiC) cladding. This study reviews advanced fuel concepts and associated fabrication methods for a GFR, followed by available carbide fuel property data, update of fuel performance code, and assessment of the fuel performance analysis model based on irradiation test results in the Fast Flux Test Facility. The purpose of this study is to develop a fuel performance code for the design and analysis of carbide fuel and to verify the implementation of fuel property models using earlier fuel irradiation tests jointly conducted by US and Switzerland. The comparison of carbide fuel simulation results to the experimental data shows differences in the prediction of fuel temperature and swelling. Considering the limitation and uncertainty of the existing material property data, the results obtained from the updated fuel performance code indicate that more work is required to adjust and update some of the carbide fuel material property models. In the future, the coolant model will also be updated for the flexibility of code application to various advanced fuel analyses. In the long term, the code will be used for the evaluation of advanced carbide fuel with ceramic cladding and the simulation of carbide fuel irradiation tests.
Flow Accelerated Corrosion — Detection and Mitigation
Authors: Kelley Aaron D.
Published: July 2014

Flow Accelerated Corrosion (FAC) has plagued the nuclear and fossil power industry with piping and components failures for over 40 years. Two-phase FAC has been recognized since about 1970, while single phase FAC has been acknowledged since the mid-1980s. U.S. and international utilities, as well as fossil utilities, recognize FAC as a major contributor to piping and component degradation.
Sensors for Small Modular Reactors Powered by Thermoelectric Generators
Authors: Tewolde Mahder , Lin Chih Chieh , Tao He , Chen Hanfei , Fu Gaosheng , Liu Di , Zhang Tao , Benjamin David , Zuo Lei , Hwang David , Longtin Jon
Published: July 2014

The aim of this work is to develop thermoelectrically powered sensing and actuating devices for normal and off-normal conditions in Small Modular Reactors (SMRs). This is realized using thermoelectric generators (TEGs) placed on key reactor components such as pipes, pump housings, heat exchangers or reactor vessels to capture waste heat and produce usable electric power. The electrical power generated is used to drive sensors, signal conditioning, and wireless communication to relay critical plant information to operators and emergency crew. Surplus power can be stored in batteries and/or super capacitors for actuation and other high-current, short-duration power needs. A review of key SMR reactor types and candidate locations for installing these devices is presented. The design and manufacturing process of an integrated TEG assembly that attaches to a schedule 40 steam pipe and preliminary test data of the system from an installation performed on a conventionally-fueled cogeneration power plant located on site are presented. The nominal pipe temperature is 350°C, and the assembly is designed to reduce the temperature to 230°C on the hot side of the TEG. A cold side temperature of 70°C was obtained using a large heat sink cooled by natural convection to the ambient. Designs for an enclosure system are also presented to protect the electrical components from fire and radiation.
Preliminary Evaluation of Core Compaction Phenomenon: Methodological Approach
Authors: Lo Frano Rosa , Pugliese Giovanni , Grasso Giacomo , Forasassi Giuseppe
Published: July 2014

Nuclear reactors have to be maintained in a critical state so as to keep the chain fission process stationary and under control. Nuclear stability considerations dictate that the geometry of the core be closely controlled at all times: therefore any modification of it must be predictable, compatible with the requirements of the interfacing reactor systems and safely manageable by (intrinsic and engineered) control mechanisms.

This study deals with the evaluation of the deformation of core (and restraint system) geometry due to dynamic perturbations. This deformation may determine, at large or small extent, an assembly compaction, that is generally characterized by a radial inward displacement and, eventually, results in an insertion of reactivity.

To the aim it is of meaningful importance to set up and develop an overall and reliable methodological approach to be used in designing the core system (all structures and components characterizing the core region) and evaluating its performance under operation and accident condition. In particular a LMR reactor configuration similar to the Advanced Lead-cooled Fast Reactor European Demonstrator - ALFRED (300 MWth) has been considered.

The assessment of the dynamic behaviour of a LMR core is particularly needed for seismic design purposes: these solicitations could deform the core system and fuel assembly. A preliminary finite element model, in which all the core sub-assemblies were represented as masses distributed on the supporting plate, was carried out in order to investigate the dynamic response of the structures once confidence was established by sensitivity analyses of size and type of the adopted elements.

The preliminary results indicate that the core region is undergoing local deformations (of about 3 cm) that could influence the normal reactor operation. Although any deformation influences the normal reactor operation, it is expected that the reactivity specifically related to this deformation will not pose concerns to the safe manageability of the associated abnormal operation.
Development of Operational Concepts for Advanced SMRs: The Role of Cognitive Systems Engineering
Authors: Hugo Jacques V. , Gertman David I.
Published: July 2014

Advanced small modular reactors (AdvSMRs) will use advanced digital instrumentation and control systems, and make greater use of automation. These advances not only pose technical and operational challenges, but will inevitably have an effect on the operating and maintenance cost of new plants. However, there is much uncertainty about the impact of AdvSMR designs on operational and human factors considerations, such as workload, situation awareness, human reliability, staffing levels, and the appropriate allocation of functions between the crew and various automated plant systems. Existing human factors and systems engineering design standards and methodologies are not current in terms of human interaction requirements for dynamic automated systems and are no longer suitable for the analysis of evolving operational concepts. New models and guidance for operational concepts for complex socio-technical systems need to adopt a state-of-the-art approach such as Cognitive Systems Engineering (CSE) that gives due consideration to the role of personnel. The approach described here helps to identify and evaluate human challenges related to non-traditional operational concepts. A framework for defining operational strategies was developed based on an analysis of the Experimental Breeder Reactor-II (EBR-II), a small (20MWe) sodium-cooled reactor that was successfully operated for thirty years. Insights from the application of the systematic application of the methodology and its utility are reviewed and arguments for the formal adoption of CSE as a value-added part of the Systems Engineering process are presented.
Dynamic Simulation of Small Modular Reactors Using Modelica
Authors: Qualls Lou , Hale Richard , Cetiner Sacit , Fugate David , Batteh John , Tiller Michael
Published: July 2014

Small modular reactors (SMRs) offer potential for addressing the nation’s long-term energy needs. However, the project design cycle for new reactor concepts is lengthy. As part of the Department of Energy’s Advanced SMR research and development program, Oak Ridge National Laboratory (ORNL) is developing a Dynamic System Modeling Tool (MoDSIM) to facilitate rapid instrumentation and controls studies of SMR concepts.

Traditional nuclear reactor design makes use of verified and validated codes to meet the strict quality assurance requirements of the licensing process for the Nuclear Regulatory Commission. However, there are significant engineering analyses and high-level decisions required prior to the rigorous design phase. These analyses typically do not require high-fidelity codes. Different organizations and researchers may examine various plant configuration options prior to formal design activities. Engineers and managers must continuously make down-selection decisions regarding potential reactor architectures and subsystems. Traditionally, the modeling of these complex systems has been based on legacy models. Considerable time and effort are necessary to understand and manipulate these legacy models. For trade-space studies, two developments in the model-based systems engineering space represent a significant advancement in the ability of engineering tools to meet these demands. The first is Modelica: a nonproprietary, equation-based, object-oriented modeling language for cyber-physical systems. The second is the Functional Mockup Interface: a standardized, open interface for model exchange, simulation, and deployment.

ORNL’s MoDSIM tool makes use of these developments and is intended to provide a flexible and robust dynamic system-modeling environment for SMRs. This includes single or multiple reactors, perhaps sharing common resources, or producing both electricity and process heat for local consumption or feeding a regional grid. MoDSIM uses the open-source modeling language (Modelica) and incorporates a user interface, coupled dynamic models, and analysis capabilities that will enable non-expert modelers to perform sophisticated end-to-end system simulations of both neutronic and thermal-hydraulic models. This approach enables open-source and crowd-source-type collaborations for model development of SMRs in an approach similar to open-source and open-design techniques currently used for software production and complex system design. As part of the tool development, an example SMR was chosen (advanced liquid metal reactor [ALMR]) and the ALMR models developed and interface tools demonstrated. For initial verification purposes, the results from these Modelica simulations are compared with the results documented for the earlier ALMR power-reactor innovative small-module concept. These results, as well as initial demonstrations of the tool for different control strategies, are presented in this paper.
Johnson Noise Thermometry for Drift-Free Measurements
Authors: Britton Charles , Bull Ezell N. Dianne , Roberts Michael , Holcomb David , Wood Richard
Published: July 2014

Temperature is a key process variable at any nuclear power plant (NPP). The harsh reactor environment causes all sensor properties to drift over time. At the higher temperatures of advanced NPPs the drift occurs more rapidly. Johnson noise is a fundamental expression of temperature and as such is immune to drift in a sensor’s physical condition. In and near the core, only Johnson noise thermometry (JNT) and radiation pyrometry offer the possibility for long-term, high-accuracy temperature measurement due to their fundamental natures. Small Modular Reactors (SMRs) place a higher value on long-term stability in their temperature measurements in that they produce less power per reactor core and thus cannot afford as much instrument recalibration labor as their larger brethren. The purpose of the current ORNL-led project, conducted under the Instrumentation, Controls, and Human-Machine Interface (ICHMI) research pathway of the U.S. Department of Energy (DOE) Advanced SMR Research and Development (R&D) program, is to develop and demonstrate a drift free Johnson noise-based thermometer suitable for deployment near core in advanced SMR plants.
Echography of young stars reveals their evolution
Authors: Zwintz K. , Fossati L. , Ryabchikova T. , Guenther D. , Aerts C. , Barnes T. G. , Themeßl N. , Lorenz D. , Cameron C. , Kuschnig R. , Pollack-Drs S. , Moravveji E. , Baglin A. , Matthews J. M. , Moffat A. F. J. , Poretti E. , Rainer M. , Rucinski S. M. , Sasselov D. , Weiss W. W.
Published: July 2014

A finger on the pulse of young stars

Adolescent stars quiver and quake before the onset of nuclear fusion in their cores. Zwintz
et al.
confirm theoretical predictions that the frequency of the seismic oscillations in a given star is tied to its evolutionary status (see the Perspective by Stahler and Palla). As the protostar evolves and contracts, growing hotter and denser, it pulsates faster. Though previously applied only to aging stars, asteroseismology now offers a powerful tool for discerning the ages of very young stars. The relative timing of star formation within young clusters especially benefits from this refinement, as stars there are often tagged with one blanket age.

Science
, this issue p.
550
; see also p.
514
Draft Genome Sequence of Escherichia coli MS499, Isolated from the Infected Uterus of a Postpartum Cow with Metritis
Authors: Goldstone Robert J. , Talbot Richard , Schuberth Hans-Joachim , Sandra Olivier , Sheldon I. Martin , Smith David G. E.
Published: July 2014

Specific
Escherichia coli
strains associated with bovine postpartum uterine infection have recently been described. Many recognized virulence factors are absent in these strains; therefore, to define a prototypic strain, we report here the genome sequence of
E. coli
isolate MS499 from a cow with the postpartum disease metritis.
Draft Genome Sequence of Vibrio fortis Dalian14 Isolated from Diseased Sea Urchin (
Strongylocentrotus intermedius
)
Authors: Ding Jun , Dou Yan , Wang Yinan , Chang Yaqing
Published: July 2014

Here, we report the draft genome sequence of
Vibrio fortis
Dalian14 isolated from diseased sea urchin (
Strongylocentrotus intermedius
) during disease outbreaks in North China. The availability of this genome sequence will facilitate the study of the mechanisms of pathogenicity and evolution of
Vibrio
species.
Draft Genome Sequence of Marine Actinomycete
Streptomyces
sp. Strain NTK 937, Producer of the Benzoxazole Antibiotic Caboxamycin
Authors: Olano Carlos , Cano-Prieto Carolina , Losada Armando A. , Bull Alan T. , Goodfellow Michael , Fiedler Hans-Peter , Méndez Carmen , Salas José A.
Published: July 2014

Streptomyces
sp. strain NTK 937 is the producer of the benzoxazole antibiotic caboxamycin, which has been shown to exert inhibitory activity against Gram-positive bacteria, cytotoxic activity against several human tumor cell lines, and inhibition of the enzyme phosphodiesterase. In this genome announcement, we present a draft genome sequence of
Streptomyces
sp. NTK 937 in which we identified at least 35 putative secondary metabolite biosynthetic gene clusters.
Complete Genome Sequence of the Bovine Mastitis Pathogen Mycoplasma californicum Strain ST-6T(ATCC 33461T)
Authors: Calcutt Michael J. , Foecking Mark F. , Fox Lawrence K.
Published: July 2014

Mycoplasma californicumis one of several mycoplasmal species associated with bovine mastitis. The complete genome sequence of 793,841 bp has been determined and annotated for theM. californicumST-6 type strain, providing a resource for the identification of surface antigens and putative pathoadaptive features.
Draft Genome Sequence of the Oleaginous Yeast Yarrowia lipolytica PO1f, a Commonly Used Metabolic Engineering Host
Authors: Liu Leqian , Alper Hal S.
Published: July 2014

The draft genome sequence of the oleaginous yeast
Yarrowia lipolytica
stain PO1f, a commonly used metabolic engineering host, is presented here. The approximately 20.3-Mb genome sequence of PO1f will greatly facilitate research efforts in metabolic engineering of
Yarrowia lipolytica
for value-added chemical production.
Ehlers–Danlos syndrome: how to diagnose and when to perform genetic tests
Authors: Sobey Glenda
Published: July 2014

The term Ehlers–Danlos syndrome (EDS) encompasses a group of inherited connective tissue disorders. The manifestations of EDS can be seen in skin, joints, blood vessels and internal organs and vary from mild to severe and life threatening. Each subtype is a separate and different condition. The genetic basis of many subtypes has now been elucidated, confirming heterogeneity. An awareness of the different conditions within this group is the starting point towards accurate diagnosis. Accurate elicitation of history and clinical signs is vital in selecting the correct confirmatory investigation. Skin biopsy with electron microscopy can be helpful in the decision process of whether and when to perform genetic testing. Correct diagnosis within the EDSs allows targeted management, family screening and prenatal diagnosis.
Accessory diaphragm associated with non-immune hydrops fetalis
Authors: Priyadarshi Archana , Sugo Ella , Challis Daniel , Bolisetty Srinivas
Published: July 2014

An accessory diaphragm, also known as diaphragmatic duplication, is a congenital anomaly in which there is a fibromuscular membrane on top of the normally formed diaphragm dividing the hemithorax into two compartments trapping part of the pulmonary parenchyma. It is a very rare anomaly with less than 40 cases reported in the literature, of which only five were diagnosed in the newborn period, with no reports on any clinical clues for the antenatal diagnosis of this condition. We describe a case of congenital accessory diaphragm presenting in the antenatal period as hydrops fetalis. We also describe the radiological features of this rare anomaly on the antenatal fetal ultrasound.
The effect of slow spaced eating on hunger and satiety in overweight and obese patients with type 2 diabetes mellitus
Authors: Angelopoulos Theodoros , Kokkinos Alexander , Liaskos Christos , Tentolouris Nicholas , Alexiadou Kleopatra , Miras Alexander Dimitri , Mourouzis Iordanis , Perrea Despoina , Pantos Constantinos , Katsilambros Nicholas , Bloom Stephen R , le Roux Carel Wynard
Published: July 2014

Background

Slow spaced eating is associated with improved satiety and gut hormone responses in normal-weight participants. This crossover study compared the effect of slow and rapid eating patterns on hunger, fullness, glucose, insulin, and the appetite-related gut hormones peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and ghrelin in overweight and obese participants with type 2 diabetes mellitus (T2DM).

Methods

20 overweight and obese participants with T2DM on metformin were recruited. A test meal of 300 mL ice-cream was consumed in random order in two different sessions by each participant; meal duration was 5 or 30 min. Fullness and hunger as assessed by visual analog scales (VAS), and glucose, insulin, PYY, GLP-1, and ghrelin were measured at baseline and at 30 min intervals after meal termination for 3 h.

Results

Fullness VAS ratings were significantly higher at the 90’, 120’, 150’, and 180’ time points and hunger ratings were lower at 90’, 150’, and 180’ for the 30 min meal. The area under the curve (AUC) for fullness was higher after the 30 min meal than after the 5 min meal (11 943.7±541.2 vs 10 901.0±568.8 mm min, p=0.003) whereas the hunger AUC was lower (4442.9±328 vs 4966.7±347.5 mm min, p=0.012). There were no differences in glucose, insulin, PYY, GLP-1, and ghrelin responses.

Conclusions

Slow spaced eating increased fullness and decreased hunger ratings in overweight and obese participants with T2DM, without the improvement in gut hormone responses found in normal-weight participants. Slow spaced eating may be a useful prevention strategy, but might also help curb food intake in those already suffering from obesity and diabetes.
The influence of smoking and impaired glucose homoeostasis on the outcome in patients presenting with an acute coronary syndrome: a cross-sectional study
Authors: Odeberg Jacob , Freitag Michael , Forssell Henrik , Vaara Ivar , Persson Marie-Louise , Odeberg Håkan , Halling Anders , Råstam Lennart , Lindblad Ulf
Published: July 2014

Objectives

Smoking, diabetes, male sex, hypercholesterolaemia and hypertension are well-established risk factors for the development of coronary artery disease (CAD). However, less is known about their role in influencing the outcome in the event of an acute coronary syndrome (ACS). The aim of this study was to determine if these risk factors are associated specifically with acute myocardial infarction (MI) or unstable angina (UA) in patients with suspected ACS.

Design

Cross-sectional study.

Setting

Patients admitted to the coronary care unit, via the emergency room, at a central county hospital over a 4-year period (1992–1996).

Participants

From 5292 patients admitted to the coronary care unit, 908 patients aged 30–74 years were selected, who at discharge had received the diagnosis of either MI (527) or UA (381). A control group consisted of 948 patients aged 30–74 years in whom a diagnosis of ACS was excluded.

Main outcome measures

MI or UA.

Results

Current smoking (OR 2.42 (1.61 to 3.62)), impaired glucose homoeostasis defined as glycated haemoglobin ≥5.5% + blood glucose ≥7.5 mM (OR 1.78 (1.19 to 2.67)) and male sex (OR 1.71 (1.21 to 2.40)) were significant factors predisposing to MI over UA, in the event of an ACS. Compared with the non-ACS group, impaired glucose homoeostasis, male sex, cholesterol level and age were significantly associated with development of an ACS (MI and UA). Interestingly, smoking was significantly associated with MI (OR 2.00 (1.32 to 3.02)), but not UA.

Conclusions

Smoking or impaired glucose homoeostasis is an acquired risk factor for a severe ACS outcome in patients with CAD. Importantly, smoking was not associated with UA, suggesting that it is not a risk factor for all clinical manifestations of CAD, but its influence is important mainly in the acute stages of ACS. Thus, on a diagnosis of CAD, the cessation of smoking and management of glucose homoeostasis are of upmost importance to avoid severe subsequent ACS consequences.
Association of early childhood abdominal circumference and weight gain with blood pressure at 36 months of age: secondary analysis of data from a prospective cohort study
Authors: Nowson Caryl A , Crozier Sarah R , Robinson Siân M , Godfrey Keith M , Lawrence Wendy T , Law Catherine M , Cooper Cyrus , Inskip Hazel M
Published: July 2014

Objectives

To assess whether changes in measures of fat distribution and body size during early life are associated with blood pressure at 36 months of age.

Design

Analysis of data collected from a prospective cohort study.

Setting

Community-based investigation in Southampton, UK.

Participants

761 children with valid blood pressure measurements, born to women participating in the Southampton Women’s Survey.

Primary and secondary outcome measures

Anthropometric measurements were collected at 0, 6, 12, 24 and 36 months and conditional changes between the time points calculated. Blood pressure was measured at 36 months. Factors possibly influencing the blood pressure were assessed using linear regression. All independent variables of interest and confounding variables were included in stepwise multiple regression to identify the model that best predicted blood pressure at 36 months.

Results

Greater conditional gains in abdominal circumference (AC) between 0–6 and 24–36 months were associated with higher systolic and diastolic blood pressures at 36 months (p<0.001). Subscapular skinfold and height gains were weakly associated with higher blood pressures, while greater weight gains between 0–6, 12–24 and 24–36 months were more strongly associated, but the dominant influences were AC gains, particularly from 0–6 to 24–36 months. Thus one SD score increases in AC between 0–6 and 24–36 months were associated with 1.59 mm Hg (95% CI 0.97 to 2.21) and 1.84 mm Hg (1.24 to 2.46) higher systolic blood pressures, respectively, and 1.04 mm Hg (0.57 to 1.51) and 1.02 mm Hg (0.56, 1.48) higher diastolic pressures, respectively.

Conclusions

Conditional gains in abdominal circumference, particularly within 6 months of birth and in the year preceding measurement, were more positively associated with blood pressure at 36 months than gains in other anthropometric measures. Above-average AC gains in early childhood may contribute to adult hypertension and increased cardiovascular disease risk.
Protocol for a randomised controlled trial of VAsopressin versus Noradrenaline as Initial therapy in Septic sHock (VANISH)
Authors: Gordon Anthony C , Mason Alexina J , Perkins Gavin D , Ashby Deborah , Brett Stephen J
Published: July 2014

Introduction

Vasopressin is an alternative vasopressor in the management of septic shock. It spares catecholamine use but whether it improves outcome remains uncertain. Current evidence suggests that it may be most effective if used early and possibly in conjunction with corticosteroids. This trial will compare vasopressin to noradrenaline as initial vasopressor in the management of adult septic shock and investigate whether there is an interaction of vasopressin with corticosteroids.

Methods and analysis

This is a multicentre, factorial (2×2), randomised, double-blind, placebo-controlled trial. 412 patients will be recruited from multiple UK intensive care units and randomised to receive vasopressin (0–0.06 U/min) or noradrenaline (0–12 µg/min) as a continuous intravenous infusion as initial vasopressor therapy. If maximum infusion rates of this first study drug are reached, the patient will be treated with either hydrocortisone (initially 50 mg intravenous bolus six-hourly) or placebo, before additional open-label catecholamine vasopressors are prescribed. The primary outcome of the trial will be the difference in renal failure-free days between treatment groups. Secondary outcomes include need for renal replacement therapy, survival rates, other organ failures and resource utilisation.

Ethics and dissemination

The trial protocol and information sheets have received a favourable opinion from the Oxford A Research Ethics Committee (12/SC/0014). There is an independent Data Monitoring and Ethics Committee and independent membership of the Trial Steering Committee including patient and public involvement. The trial results will be published in peer-reviewed journals and presented at national and international scientific meetings.

Trial registration number:

ISRCTN 20769191 and EudraCT 2011-005363-24.
Solutions to the modified Korteweg–de Vries equation
Authors: Zhang Da-Jun , Zhao Song-Lin , Sun Ying-Ying , Zhou Jing
Published: July 2014

This is a continuation of [Notes on solutions in Wronskian form to soliton equations: Korteweg–de Vries-type, arXiv:nlin.SI/0603008]. In the present paper, we review solutions to the modified Korteweg–de Vries equation in terms of Wronskians. The Wronskian entry vector needs to satisfy a matrix differential equation set which contains complex operation. This fact makes the analysis of the modified Korteweg–de Vries to be different from the case of the Korteweg–de Vries equation. To derive complete solution expressions for the matrix differential equation set, we introduce an auxiliary matrix to deal with the complex operation. As a result, the obtained solutions to the modified Korteweg–de Vries equation are categorized into two types: solitons and breathers, together with their limit cases. Besides, we give rational solutions to the modified Korteweg–de Vries equation in Wronskian form. This is derived with the help of a Galilean transformed version of the modified Korteweg–de Vries equation. Finally, typical dynamics of the obtained solutions are analyzed and illustrated. We also list out the obtained solutions and their corresponding basic Wronskian vectors in the conclusion part.
Nonlinear Energy Harvesting from Random Narrow-Band Excitations
Authors: Khovanova Natalia , Khovanov Igor , Davletzhanova Zarina
Published: July 2014

The efficiency of linear and nonlinear harvesters with different types of nonlinearity is compared. Narrow band ambient vibrations are modeled by harmonic Gaussian noise. We show that the performance of nonlinear harvesters strongly depends on both the form of nonlinearity and the properties of the noise. Particular forms of nonlinearities which can produce a better than linear response are identified, and these depend on the spectral width of the harmonic noise.
Developing a Train Noise Index for Noise Pollution Assessment of Inter-Urban Trains
Authors: Monazzam Mohammad Reza , Nasserpour Mahsa , Naderzadeh Mahdieh , Pouragha Hamid Reza , Izadpanah Faezeh , Zaredar Narges , Meshkani Mohsen
Published: July 2014

In many countries, railway is considered as the second source of ambient noise pollution, just after the noise from urban traffic. It is out of the question that the train noise is very annoying for the inhabitants in surrounding areas. The present study assessed noise pollution caused by passing inter-urban trains in southern Tehran using sound statistical parameters. In order to assess train noise pollution of areas surrounding the inter-urban railroads including residential and industrial places, as well as healthcare centers, a total number of 99 measurement stations were selected. To that end, the instruction present by EPA was followed up to measure maximum, minimum and equivalent sound level using sound level meter of TES 1358 type. Finally, a train noise index (TRNI) was derived from the relevant equations and field measurements. The obtained results revealed that the equivalent sound level was equal to 77.21 dB throughout the axis Tehran–Khorasan and 74.38 dB within the axis Tehran–Azerbaijan at all intervals of 15, 25, 50, 100 and 200 m from the railway. The investigations also suggested that with increasing distance from 15 to 200 m, the daily equivalent sound level decreases around 12.55 and 17.73 dB in axes Tehran–Khorasan and Tehran–Azerbaijan, respectively. The TRNI was also decreased equal to 18 and 16.53 dB in the axes Tehran–Khorasan and Tehran–Azerbaijan, severally. Involving multiple criteria including maximum, minimum and equivalent sound level, the TRNI is much more accurate than mere equivalent sound level so it would be more appropriate tool for noise pollution assessment.
Using Physics to Diagnose Cancer
Authors: James Veronica J.
Published: July 2014

This discussion about diagnostic tests for cancer incorporates a powerful branch of Physics namely X-ray diffraction. Although this technique was used to solve the DNA structure using the X-ray diffraction pictures of Rosalind Franklin,1 and the structure of vitamin B12 by Dorothy Hodgkin2 and hosts of other medical related structures, it is poorly understood by the general medical profession and the community at large. To the nonphysicist the patterns appear to have no relation to the results produced. It might as well be written in Greek. The well-known quote of Poincaré, the famous French mathematician and scientist, in 1885 comes to mind: "Science is built up with facts as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house."

In order therefore to build a true understanding of this powerful technique it is necessary to build a firm understanding of the basic facts about this technique, so that the final results will be clear to all, as they will be held up by a firm house of knowledge. So let us take up the first stone.
Conjecture on the Lateral Growth of Type I Collagen Fibrils
Authors: Charvolin Jean , Sadoc Jean-François
Published: July 2014

Type I collagen fibrils have circular cross sections with radii mostly distributed in between 50 and 100 nm and are characterized by an axial banding pattern with a period of 67 nm. The constituent long molecules of those fibrils, the so-called triple helices, are densely packed but their nature is such that their assembly must conciliate two conflicting requirements. One is a double-twist around the axis of the fibril induced by their chirality and the other is a periodic layered organization, corresponding to the axial banding, built by specific lateral interactions. We examine here how such a conflict could contribute to the control of the radius of a fibril. We develop our analysis with the help of two geometrical archetypes: the Hopf fibration and the algorithm of phyllotaxis. The first one provides an ideal template for a twisted bundle of fibres and the second ensures the best homogeneity and local isotropy possible for a twisted dense packing with circular symmetry. This approach shows that, as the radius of a fibril with constant double-twist increases, the periodic layered organization can not be preserved without moving from planar to helicoidal configurations. Such changes of configurations are indeed made possible by the edge dislocations naturally present in the phyllotactic pattern. The distribution of those defects is such that the lateral growth of a fibril should stay limited in the observed range. Because of our limited knowledge about the elastic constants involved, this purely geometrical development stays at a quite conjectural level.
SPIN RELAXATION IN InP AND STRAINED InP NANOWIRES
Authors: SALIMATH AKSHAYKUMAR , GHOSH BAHNIMAN
Published: July 2014

In this paper, we employ semiclassical Monte Carlo approach to study spin polarized transport in InP and strained InP nanowires on GaAs substrate. Due to higher spin relaxation lengths, InP is being researched as suitable III–V material for spintronics related applications. Spin relaxation in InP channel is as a result of D'yakonov–Perel (DP) relaxation and Elliott–Yafet (EY) relaxation. We have considered injection polarization along z-direction and the magnitude of ensemble averaged spin variation is studied along the x-direction i.e., along transport direction. The effect of strain on various scattering rates and spin relaxation length is studied. We then present the effect of variation of nanowire width on spin relaxation length for the case of both strained and unstrained InP nanowire. The wire cross-section is varied between 4 × 4 nm2 and 10 × 10 nm2.
Changes in glucose-6-phosphate dehydrogenase expression results in altered behavior of HBV-associated liver cancer cells
Authors: Hu Huaidong , Ding Xiangchun , Yang Yixuan , Zhang Hongmin , Li Hong , Tong Shiwen , An Xuan , Zhong Qing , Liu Xiaoyan , Ma Lina , Liu Qing , Liu Bin , Lu Zhenhui , Zhang Dazhi , Hu Peng , Ren Hong
Published: July 2014

Hepatocellular carcinoma (HCC) is regarded as a major global health care issue, and chronic hepatitis B virus (HBV) infection is considered to be involved in pathogenesis of HCC. To increase knowledge of HCC pathogenesis, as well as discover potential novel molecules for anti-cancer therapy, mass spectrometry and isobaric tag for relative and absolute quantitation (iTARQ) were employed. The differences between nine HBV-related HCC and adjacent non-HCC tissue specimens were studied. In total, 222 proteins were analyzed for differential expression in the two types of samples. Among these proteins, several were further confirmed by immunohistochemical, immunoblotting, and real-time RT-PCR analysis. RNA interference induced downregulation of glucose-6-phosphate dehydrogenase (G6PD) and decreased HBV replication by fivefold by the IFN pathway. Decreased G6PD expression resulted in decreased hepatoma cell migration and invasion in cell culture. In summary, the investigation provides new information on pathogenesis of HBV infection and suggests G6PD as a novel anti-HCC target. G6PD suppression may contribute to treatment strategies for inhibiting tumor progression.
Myoarchitectural and functional alterations in rabbit external anal sphincter muscle following experimental surgical trauma
Authors: Raj Rajasekaran M. , Sinha Shantanu , Seo Youngjin , Salehi Mitra , Bhargava Valmik , Mittal Ravinder K.
Published: July 2014

Obstetrical trauma to external anal sphincter (EAS) is extremely common; however, its role in the development of anal incontinence is not clear. We examined the regenerative process and functional impact of experimental surgical trauma to EAS muscle in an animal model. Surgical myotomy, a craniocaudal incision extending along the entire length and thickness of the EAS, was performed in rabbits. Animals were allowed to recover, and anal pressures were recorded at weekly intervals for 12 wk using a custom-designed probe system to determine the length-tension property of EAS muscle. Animals were killed at predetermined time intervals, and the anal canal was harvested for histochemical studies (for determination of muscle/connective tissue/collagen) and sarcomere length measurement. In addition, magnetic resonance diffusion tensor imaging (MR-DTI) and fiber tracking was performed to determine myoarchitectural changes in the EAS. Myotomy of the EAS muscle resulted in significant impairment of its length-tension property that showed only partial recovery during the 12-wk study period. Histology revealed marked increase in the fibrosis (connective tissue = 69% following myotomy vs. 28% in controls) at 3 wk, which persisted at 12 wk. Immunostaining studies confirmed deposition of collagen in the fibrotic tissue. There was no change in the sarcomere length following myotomy. MR-DTI studies revealed disorganized muscle fiber orientation in the regenerating muscle. We conclude that, following experimental injury, the EAS muscle heals with an increase in the collagen content and loss of normal myoarchitecture, which we suspect is the cause of impaired EAS function.
Sympathoexcitation and pressor responses induced by ethanol in the central nucleus of amygdala involves activation of NMDA receptors in rats
Authors: Chapp Andrew D. , Gui Le , Huber Michael J. , Liu Jinling , Larson Robert A. , Zhu Jianhua , Carter Jason R. , Chen Qing-Hui
Published: July 2014

The central nervous system plays an important role in regulating sympathetic outflow and arterial pressure in response to ethanol exposure. However, the underlying neural mechanisms have not been fully understood. In the present study, we tested the hypothesis that injection of ethanol in the central nucleus of the amygdala (CeA) increases sympathetic outflow, which may require the activation of local ionotropic excitatory amino acid receptors. In anesthetized rats, CeA injection of ethanol (0, 0.17, and 1.7 μmol) increased splanchnic sympathetic nerve activity (SSNA), lumbar sympathetic nerve activity (LSNA), and mean arterial pressure (MAP) in a dose-dependent manner. A cocktail containing ethanol (1.7 μmol) and kynurenate (KYN), an ionotropic excitatory amino acid receptor blocker, showed significantly blunted sympathoexcitatory and pressor responses compared with those elicited by CeA-injected ethanol alone ( P < 0.01). A cocktail containing ethanol and d-2-amino-5-phosphonovalerate, an N-methyl-d-aspartate (NMDA) receptor antagonist, elicited attenuated sympathoexcitatory and pressor responses that were significantly less than ethanol alone ( P < 0.01). In addition, CeA injection of acetate (0.20 μmol, n = 7), an ethanol metabolite, consistently elicited sympathoexcitatory and pressor responses, which were effectively blocked by d-2-amino-5-phosphonovalerate ( n = 9, P < 0.05). Inhibition of neuronal activity of the rostral ventrolateral medulla (RVLM) with KYN significantly ( P < 0.01) attenuated sympathoexcitatory responses elicited by CeA-injected ethanol. Double labeling of immune fluorescence showed NMDA NR1 receptor expression in CeA neurons projecting to the RVLM. We conclude that ethanol and acetate increase sympathetic outflow and arterial pressure, which may involve the activation of NMDA receptors in CeA neurons projecting to the RVLM.
Comparison of arterial pressure and plasma ANG II responses to three methods of subcutaneous ANG II administration
Authors: Kuroki Marcos T. , Fink Gregory D. , Osborn John W.
Published: July 2014

Angiotensin II (ANG II)-induced hypertension is a commonly studied model of experimental hypertension, particularly in rodents, and is often generated by subcutaneous delivery of ANG II using Alzet osmotic minipumps chronically implanted under the skin. We have observed that, in a subset of animals subjected to this protocol, mean arterial pressure (MAP) begins to decline gradually starting the second week of ANG II infusion, resulting in a blunting of the slow pressor response and reduced final MAP. We hypothesized that this variability in the slow pressor response to ANG II was mainly due to factors unique to Alzet pumps. To test this, we compared the pressure profile and changes in plasma ANG II levels during subcutaneous ANG II administration (150 ng·kg−1·min−1) using either Alzet minipumps, iPrecio implantable pumps, or a Harvard external infusion pump. At the end of 14 days of ANG II, MAP was highest in the iPrecio group (156 ± 3 mmHg) followed by Harvard (140 ± 3 mmHg) and Alzet (122 ± 3 mmHg) groups. The rate of the slow pressor response, measured as daily increases in pressure averaged over days 2–14 of ANG II, was similar between iPrecio and Harvard groups (2.7 ± 0.4 and 2.2 ± 0.4 mmHg/day) but was significantly blunted in the Alzet group (0.4 ± 0.4 mmHg/day) due to a gradual decline in MAP in a subset of rats. We also found differences in the temporal profile of plasma ANG II between infusion groups. We conclude that the gradual decline in MAP observed in a subset of rats during ANG II infusion using Alzet pumps is mainly due to pump-dependent factors when applied in this particular context.
Atg7 deficiency impairs host defense against Klebsiella pneumoniae by impacting bacterial clearance, survival and inflammatory responses in mice
Authors: Ye Yan , Li Xuefeng , Wang Wenxue , Ouedraogo Kiswendsida Claude , Li Yi , Gan Changpei , Tan Shirui , Zhou Xikun , Wu Min
Published: July 2014

Klebsiella pneumoniae (Kp) is a Gram-negative bacterium that can cause serious infections in humans. Autophagy-related gene 7 (Atg7) has been implicated in certain bacterial infections; however, the role of Atg7 in macrophage-mediated immunity against Kp infection has not been elucidated. Here we showed that Atg7 expression was significantly increased in murine alveolar macrophages (MH-S) upon Kp infection, indicating that Atg7 participated in host defense. Knocking down Atg7 with small-interfering RNA increased bacterial burdens in MH-S cells. Using cell biology assays and whole animal imaging analysis, we found that compared with wild-type mice atg7 knockout (KO) mice exhibited increased susceptibility to Kp infection, with decreased survival rates, decreased bacterial clearance, and intensified lung injury. Moreover, Kp infection induced excessive proinflammatory cytokines and superoxide in the lung of atg7 KO mice. Similarly, silencing Atg7 in MH-S cells markedly increased expression levels of proinflammatory cytokines. Collectively, these findings reveal that Atg7 offers critical resistance to Kp infection by modulating both systemic and local production of proinflammatory cytokines.