bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implementation of an in‐field CMOS frequency division multiplexer for 9.4 T magnetic resonance applications
Authors: Jouda Mazin , Gruschke Oliver G. , Korvink Jan G. 
Published: November 2014

SummaryThis paper introduces the implementation of an application‐specific complementary metal oxide semiconductor frequency division multiplexer as a novel solution to interface magnetic resonance (MR) phased arrays of micro‐detectors to an image‐processing unit, thus reducing the complexity and space issues associated with MR detector arrays. The frequency multiplexer, in a compact 3 × 4 mm silicon die, is designed to operate at 400 MHz, which is the Larmor frequency of 1H protons in a 9.4‐T MR imaging system. The system implements eight channels, where each channel consists of a low‐noise amplifier, a frequency mixer, and a band‐pass filter. The maximum gain of an individual channel after the band‐pass filter stage is 38 dB. The suppression of the local oscillator ranges from 40 to −51 dB, and the maximum coupling between channels is −39 dB. The input dynamic range of an individual channel is 8 mV. Each channel consumes 54 mA from a 3.3‐V source. The chip operates without errors within a high 9.4‐T magnetic field. Copyright © 2014 John Wiley & Sons, Ltd.
The prognostic significance of atrial fibrillation in heart failure with a preserved and reduced left ventricular function: insights from a meta‐analysis
Authors: Cheng Min , Lu Xiangfeng , Huang Jianfeng , Zhang Jian , Zhang Shu , Gu Dongfeng 
Published: November 2014

BackgroundThe prognostic significance of atrial fibrillation (AF) in patients with heart failure remains inconclusive.AimsTo perform a meta‐analysis of the published data to study the prognostic significance of AF in heart failure patients and to determine whether this relates to the presence of preserved or reduced left ventricular systolic function.Methods and resultsWe searched the MEDLINE (from inception to May 2014) supplemented by manual searches of references of relevant retrieved articles. Randomized clinic trials and observational studies were included with hazard ratios (HRs) of AF for mortality in chronic heart failure patients. The search strategy yielded 20 studies that met our eligibility criteria. A total of 61 240 AF patients in 152 306 heart failure participants were included, with 39 879 deaths occurring during follow‐up. Pooled HRs for AF in mortality in heart failure was 1.17 (95% confidence intervals: 1.11–1.23) using random‐effect model (I2 = 44.5%). There was a significant difference of combined HRs between heart failure patients with preserved and reduced left ventricular ejection fraction (LVEF) in separate analysis. Sensitivity analysis supported the consistence of the results.ConclusionsAtrial fibrillation is significantly associated with increased mortality in heart failure patients. The prognostic significance of AF may be different between heart failure with preserved and reduced LVEF, and AF is associated with poorer prognosis in heart failure patients with preserved LVEF.
Theoretical Search for an Iron‐Based Magnetic Superhalogen with Halogen or Interhalogen as Ligand
Authors: Ding Li‐Ping , Kuang Xiao‐Yu , Shao Peng 
Published: November 2014

AbstractBy using density functional theory, we have investigated the geometrical structures, electrophilic properties, magnetic properties, and fragmentation channels of FeXn (X = Cl, Br; n = 1–6) clusters as well as the “mixed species” that contain interhalogen compounds. Our main objectives are to design new iron‐based magnetic superhalogens and to explore whether the interhalogen compounds are suitable for the superhalogen ligand. By calculating their adiabatic electron affinities (AEAs) and vertical detachment energies (VDEs), we found that both FeCln and FeBrn can be classified as superhalogens for n ≥ 3. Among mixed species, FeClF3, FeBrF3, FeClF5, and FeBrF5 are superhalogens, but their AEA values are still smaller than those of the correspondingly sized FeFn clusters. Their superhalogen properties are further supported by the natural population analysis (NPA) charge distribution and the HOMO of anions. However, in mixed species, the extra electron and HOMO do not uniformly delocalize over the different halogen atoms. This might be the reason why FeXYn possesses relatively small AEA values. In addition, we also studied the superhalogen salts formed with these superhalogen anions and Na+, which greatly enhance the reliability of our obtained superhalogens.
Rapid Synthesis of Unsymmetrical Sulforhodamines Through Nucleophilic Amination of a Monobrominated Sulfoxanthene Dye
Authors: Chevalier Arnaud , Renault Kevin , Boschetti Frédéric , Renard Pierre‐Yves , Romieu Anthony 
Published: November 2014

AbstractA transition‐metal‐free method for the synthesis of N‐substituted unsymmetrical sulforhodamine fluorophores from an unusual monobrominated sulfoxanthene dye and primary or secondary amines by direct SNAr‐type reactions is presented. The simplicity and effectiveness of this “postamination” procedure were demonstrated through the rapid preparation of a library of multifunctional red‐emitting rhodamine analogues. Some of these analogues are equipped with a reactive handle and retain the two water‐solubilizing sulfonic acid moieties of the starting halogenated derivative; this makes them ideal candidates for biolabeling applications. The potential utility of this expeditious strategy to finely tune the photophysical (Stokes shift) and physicochemical properties (amphiphilic character and water solubility) of the sulforhodamine scaffold was also demonstrated through the appendage of a fluorescent amine to create a fluorescence resonance energy transfer (FRET) pair, a long‐chain amine, and tetraazamacrocycles derived from cyclen.
The First Bidirectional [4+2] Cycloadditions of Benzo[1,2:4,5]dicyclobutenes: Synthesis of Benzo[1,2‐f:4,5‐f′]diisoindole‐1,3,7,9‐tetraones
Authors: Abdelhamid Ismail Abdelshafy , Butenschön Holger 
Published: November 2014

AbstractBidirectional reactions are an efficient tool for the synthesis of larger, often symmetric compounds. Whereas the ring opening of benzocyclobutene derivatives with subsequent cycloaddition of the ortho‐quinodimethanes formed has been used extensively for the syntheses of various classes of compounds such as steroids, acenes, and natural as well as synthetic oligocycles including heterocyclic systems, the respective bidirectional reactions have barely been explored. Here, the first bidirectional cycloadditions starting from benzo[1,2:4,5]dicyclobutene derivatives are presented using N‐methylmaleinimide as the dienophile. The benzo[1,2:4,5]dicyclobutene derivatives used have in common that they are dimethylacetals of the respective diones. As a consequence, the cycloadducts easily undergo elimination of methanol. Subsequent dehydrogenations generate the aromatic anthracene systems, which are part of the benzo[1,2‐f:4,5‐f′]diisoindole‐1,3,7,9‐tetraone derivatives formed as the final products.
Gaze behaviour when monitoring pain faces: An eye‐tracking study
Authors: Priebe J.A. , Messingschlager M. , Lautenbacher S. 
Published: November 2014

AbstractBackgroundThe vigilance‐(attentional) avoidance hypothesis (VAH) developed for explaining phobic reactions describes an early attentional bias towards a feared stimulus followed by attentional avoidance of this stimulus. Such a pattern of attentional shifts might also be found when processing of pain‐related stimuli is required. The purpose of the present study was to test the VAH for pain‐associated stimuli, i.e., faces displaying pain, using the method of eye‐tracking in a pain‐free sample.MethodsForty‐eight healthy participants observed pictures of faces displaying pain and other emotions (anger, joy), presented concurrently with neutral faces, while their gaze behaviours were recorded continuously.ResultsAnalysis of the time course of fixation durations revealed a distinct pattern for pain faces. Participants gazed at pain faces longer than at neutral faces at the beginning (up to 1000 ms) but reduced preference for pain faces increasingly thereafter (up to 2000 ms); this decline in vigilance did not occur for anger and joy faces. Strong fear of pain (Fear of Pain Questionnaire) tended to increase attentional preference for negative faces (pain, anger), a finding, which however did not reach significance.ConclusionsWe assume that initial vigilance for pain‐associated stimuli might reflect an adaptive reaction to detect a potentially harmful stimulus. Subsequently, the pain‐associated stimulus might be less attended for the purpose of mood regulation when all clear is given in this situation.
CGRP receptor blockade by MK‐8825 alleviates allodynia in infraorbital nerve‐ligated rats
Authors: Michot B. , Kayser V. , Hamon M. , Bourgoin S. 
Published: November 2014

AbstractBackgroundPrevious data showed that, in rats, anti‐migraine drugs (triptans, olcegepant) significantly reduced mechanical allodynia induced by infraorbital nerve (ION) ligation but not that evoked by sciatic nerve (SN) ligation. Whether this also occurs with MK‐8825, a novel anti‐migraine drug also acting through CGRP receptor blockade (but chemically unrelated to olcegepant) was tested in the present study, which also investigated possible anti‐neuroinflammatory effects of this drug.MethodsAdult male Sprague‐Dawley rats underwent unilateral chronic constriction injury (CCI) to either the ION or the SN, and mechanical allodynia was assessed 2 weeks later within the ipsilateral vibrissae territory or hindpaw, respectively. Transcripts of neuroinflammatory markers were quantified by real‐time quantitative RT‐PCR in ipsilateral trigeminal ganglion and spinal trigeminal nucleus in CCI‐ION rats.ResultsAcute as well as repeated (for 4 days) administration of MK‐8825 (30–100 mg/kg, i.p.) significantly reduced CCI‐ION‐induced mechanical allodynia but was ineffective in CCI‐SN rats. CCI‐ION was associated with marked up‐regulation of neuronal and glial inflammatory markers (ATF3, IL6, iNOS, COX2) in ipsilateral trigeminal ganglion but not spinal trigeminal nucleus. MK‐8825‐induced inhibition of iNOS mRNA up‐regulation probably underlay its anti‐allodynic effect because pharmacological blockade of iNOS by AMT (6 mg/kg, s.c.) mimicked this effect.ConclusionsThese data further support the idea that CGRP receptor blockade might be a valuable approach to alleviate trigeminal, but not spinal, neuropathic pain through, at least partly, an inhibitory effect on neuropathic pain‐associated increase in NO production in trigeminal ganglion.
Environmental contaminants and chromosomal damage associated with beak deformities in a resident North American passerine
Authors: Handel Colleen M. , Van Hemert Caroline 
Published: November 2014

Abstract

A large cluster of beak abnormalities among black-capped chickadees (Poecile atricapillus) in Alaska raised concern about underlying environmental factors in this region. Metals and trace elements, organochlorine pesticides, polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-dioxins and polychlorinated dibenzofurans (PCDD-Fs) were analyzed in adults, nestlings, and eggs of the affected population; local bird seed was also tested for organochlorine pesticides. The results offered no support for the hypothesis that selenium or any other inorganic element was responsible for beak deformities among chickadees, but some evidence that organochlorine compounds may be contributing factors. Adults with beak deformities had an elevated level of chromosomal damage, which was correlated with lipid level and concentrations of several organochlorine compounds. Multivariate analyses of pesticides and PCBs did not distinguish abnormal from normal adults, but subsequent univariate analysis demonstrated higher concentrations of heptachlor epoxide and PCB-123 in abnormal adults. Concentrations of all organochlorine compounds were low, and none is known to cause beak or keratin abnormalities. Patterns of PCB congener concentrations differed between nestlings with normal and abnormal parents. Eggs from clutches with low hatchability had higher concentrations of hexachlorobenzene and PCDD-Fs than those with high hatching success, and hexachlorobenzene was found in seeds. Additional testing for PCDD-Fs, polycyclic aromatic hydrocarbons, and other emerging contaminants, including brominated compounds, is needed to rule out environmental contaminants as a cause of beak deformities in chickadees in Alaska. Environ Toxicol Chem 2014;9999:1–14. Published 2014 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Oxidation Catalysis by Rationally Designed Artificial Metalloenzymes
Authors: Marchi‐Delapierre Caroline , Rondot Laurianne , Cavazza Christine , Ménage Stéphane 
Published: November 2014

AbstractThe principle of enzyme mimics has been raised to its pinnacle by the design of hybrids made from inorganic complexes embedded into biomolecules. The present review focuses on the design of artificial metalloenzymes for oxidation reactions by oxygen transfer reactions, with a special focus on proteins anchoring inorganic complexes or metal ions via supramolecular interactions. Such reactions are of great interest for the organic synthesis of building blocks. In the first part, following an overview of the different design of artificial enzymes, the review presents contributions to the rational design of efficient hybrid biocatalysts via supramolecular host/guest approaches, based on the nature of the inorganic complex and the nature of the protein, with special attention to the substrate binding. In the second part, the original purpose of artificial metalloenzymes has been twisted to enable the observation of transient intermediates, to decipher metal‐based oxidation mechanisms. The host protein crystals have been used as crystalline molecular‐scale vessels, within which inorganic catalytic reactions have been followed, thanks to X‐ray crystallography. These hybrids should be an alternative to enzymes for sustainable chemistry.
Risk Management in a Complex Development Environment: An Example
Authors: Nolte Jerry , Damsky Mike 
Published: November 2014

AbstractRisk management is a hot topic that most Systems Engineers consider important, however, many differ in the strategy of implementation. Most Systems Engineers use different ad hoc methods, based on their own experience, along with structured methodologies to implement risk management This paper describes a general structure for risk management in a development environment. The paper also describes the implementation of this general risk management plan for a specific development project extended over two years. The paper presents the lessons learned on doing risk management for this project along with a strategy for implementing risk management on future problems.
TRACEABILITY FOR COMPLEX SYSTEMS ENGINEERING
Authors: White Stephanie 
Published: November 2014

AbstractImproved requirements traceability would result in significant cost savings since more requirements problems are due to failures in requirements management than failures in technical functions. Without adequate requirements traceability, errors are found late in system development and are expensive to repair.Our research identifies problems with industry's capability to trace product and process information, and offers some solutions1. We have defined a unique method, Concurrent Stimulus‐Response Threads (CSRT), that traces complex system behavior. Based on CSRT and Entity‐Relationship modeling, we make recommendations that will improve traceability in two requirements methods, Requirements Driven Design (RDD), and Real‐Time Structured Analysis (RT‐SA).
REQUIREMENTS MANAGEMENT: DOORS TO THE BATTLEFIELD OF THE FUTURE
Authors: Rundlet Nancy , Miller William D. 
Published: November 2014

AbstractThe integration of systems to create a stable, robustsystem of systemsposes challenges to systems engineering management when the individual systems already exist, are numerous and rapidly evolving. The Dynamic Object Oriented Requirements System (DOORSTM) introduces advanced object‐oriented techniques to manage the complexity of large numbers of inter‐linked requirements. DOORS provides an easy‐to‐use, online environment. Different on‐line views of the project status are available in both text and hierarchical graphical formats by filtering and sorting on the attributes of the objects. This object‐oriented approach to requirements management is extended to provide agroupwaresystems engineering management environment in support of the U.S. Army's program todigitizethe battlefield of the future. The Army's intent is to improve their comparative advantage in combat effectiveness over that of potential adversaries. The magnitude and complexity of the effort to manage the project compared to classical requirements management methodologies and tools are discussed.
RE‐VIEWS A REQUIREMENTS STRUCTURE AND VIEWS
Authors: Edwards Michael , White Stephanie 
Published: November 2014

AbstractNumerous stakeholders collaborate to develop the system requirements for a complex system. They conceive needs, evaluate risk, cost and benefits, identify tradeoffs, and negotiate priorities over a considerable period of time. Government and industry need a structured approach to requirements elicitation that completely captures stakeholder requirements and supports necessary analysis, tradeoffs, and negotiation. Automated support for this collaborative process is a long term goal of our research 1. Our initial goal is to develop a firm foundation for capturing requirements and supporting different views. This paper discusses the need for a structure that supports requirements capture and the advantages of such a structure, identifies problems in developing a structure, and provides a high level description of information that should be captured.
REQUIREMENTS MANAGEMENT IMPLEMENTATION ROADBLOCKS
Authors: Simon Beth E. 
Published: November 2014

ABSTRACTIn trying to implement requirements management on a project, several roadblocks may be encountered. By knowing the difficulties others have encountered, you will be able to anticipate the roadblocks and plan how to deal with them. This paper is part of a series being developed by the NCOSE Requirements Management Implementation Subcommittee of the Requirements Management Committee. Follow on papers will focus on solutions to the problems outlined.
Structured Requirements and a Systems Engineering Environment
Authors: Stevens Richard 
Published: November 2014

AbstractA requirements management system forms the natural framework for a systems engineering environment (SEE). Requirements control the whole system, and cover the whole lifecycle. Requirements are the means of communication between systems engineers and all the specialist disciplines. A SEE based on requirements allows control at any required level of detail. This approach allows an incremental approach to developing a complete project toolset. This paper defines a SEE, in relationship to a commercial requirements management tool, DOORS.Systems engineering covers systems‐level tasks, such as the creation of requirements, technical management, and verification management. Tools used for specialist tasks remain outside the SEE although it will need to communicate with those.
GENERATING OPERATIONS BASED REQUIREMENTS
Authors: DeFoe Joseph C. , McAuley James E. 
Published: November 2014

AbstractThis paper presents a process for generating capability requirements based upon intended/needed operations and mission objectives. The process addresses the uncertainties associated with:
Understanding the customer/user problem
Selecting analysis and documentation methods best suited to the problem.
The uncertainty associated with the customer/user problem is addressed by having the process stringently separate the analysis phase from the requirements (“shall”) statements documentation phase.The uncertainty associated with analysis and documentation methods is addressed by having the process include an early phase in which one typical capability is analyzed in depth and then abstracted into requirements statements. The objective is to select and tailor methods prior to addressing the full range of capabilities that need to be specified.This paper also identifies the value that the current system modeling methods bring to the process.
BREATHING SE LIFE INTO EXISTING DOD PROGRAMS
Authors: Kepchar Kenneth J. 
Published: November 2014

AbstractThe mid‐stream integration of a formal Requirements Management (RM) process into an existing Department of Defense (DOD) program with a traditional approach to design&development poses special challenges. A number of compromises are necessary to avoid disrupting the design processes that are in place and functioning on the program, while changing the traditional view of the design community on identifying and verifying proper implementation of requirements. Experience on a follow‐on development program, the F/A‐18E/F, illustrates some of the benefits and difficulties involved.
Strategies For Sustaining Competitive Advantage Through Product Development: A System Engineering Framework
Authors: Sherry Lance 
Published: November 2014

AbstractCompetitive advantage in an industry can be achieved by strategically entering a marketplace at the right time with a product that has the appropriate cost and operational capability to match the needs and maturity of the marketplace. In products (such as software‐based products) where the cost and time‐to‐market are primarily a function of the “intellectual” engineering process, the product development function is the source of competitive advantage.This paper introduces a system engineering framework that describes the relationship between product operational capability, development cost, and development cycle‐time (time‐to‐market). Analysis of this relationship yields four strategies for achieving and sustaining competitive advantage through product development.
RAPID PROTOTYPING IN REQUIREMENTS SPECIFICATION PHASE OF SOFTWARE SYSTEMS
Authors: Ghajar‐Dowlatshahi Jahangir , Vernekar Ashok 
Published: November 2014

AbstractEnd‐user involvement in the requirement specification phase is essential for the success of a software product. Software developers and architects must be able to easily and accurately translate the requirements to software codes; visualize interdependencies among different functions, objects and rules; and understand system limitations.Using the rapid prototyping technique in the requirement analysis and specification phase is one way of achieving the goals of high quality software, lower development cost, on‐time delivery and user satisfaction.This paper discusses the use of the rapid prototyping technique in the requirements phase of a software development cycle. It describes the advantages of using prototyping in all applications, especially in the design and development of systems which have complex user interfaces. The paper explores the user‐centered approach in relation to the rapid prototyping technique.The rapid prototyping technique has been successfully used in several AT&T software projects. This paper also includes the authors' experiences in applying the technique to software projects.