bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas permeation and positron annihilation lifetime spectroscopy of poly(ether imide)s with varying ether
Authors: Pethrick R. A. , Santamaria‐Mendia F.
Published: January 2016

A series of poly(ether imide)s are investigated using positron annihilation lifetime spectra [PALS] and gas permeation measurements. The glass transition temperature Tg, determined by differential scanning calorimetry, does not correlate with the void sizes calculated from density or determined by PALS, implying that in these materials polymer−polymer chain interactions and not free volume has a dominant role in determining the overall chain dynamics. Significant differences observed in the permeability process with respect to carbon dioxide and nitrogen, highlight the role of polar interactions between the diffusing gas molecule and the polymer matrix on the transport processes. Diffusion coefficients do not change in a simple manner with void size. The solubility parameters vary across the series of materials and produce a small variation in the solubility coefficients for nitrogen and argon, but significantly differences were observed for carbon dioxide, reflecting the influence of polar interactions plasticizing the matrix. This study indicates that whilst the void structure is important in influencing gas transport, chain–chain interactions are controlling many of the higher temperature physical properties of these polymers. High values of selectivity between carbon dioxide and nitrogen were observed indicating that these materials have potential applications as gas separation membranes. POLYM. ENG. SCI., 56:427–434, 2016. © 2016 Society of Plastics Engineers
Dielectric and conductivity relaxation in poly(3,4‐ethylenedioxythiophene) nanotubes
Authors: Chutia Paragjyoti , Kumar Ashok
Published: January 2016

The charge carriers relaxation dynamics in synthesized poly(3,4‐ethylenedioxythiophene) nanotubes has been investigated as a function of frequency and temperature through the framework of dielectric permittivity, modulus formalism and impedance formalism. The fitting of experimental data of real part of dielectric permittivity and imaginary part of modulus with Havriliak‐Negami equation and Bergman modified Kohlrausch‐Williams‐Watts function indicates the presence of non‐Debye type relaxation process in the synthesized poly(3,4‐ethylenedioxythiophene) nanotubes. The scaling of imaginary part of modulus and impedance formalisms have been performed to understand the charge carrier relaxation dynamics in the synthesized samples, which suggests the presence of time temperature superposition principle in the nanotubes. The red shifting of the band from 1440 cm−1 to 1430 cm−1 in micro‐Raman spectra indicates the conformational transition from benzenoid to quinoid structure with increasing dopant concentration. The linear increase of imaginary part of dielectric permittivity with decreasing frequency is ascribed to the higher contribution from dc conductivity as compared to that from the electrode polarization effects. POLYM. ENG. SCI., 56:448–457, 2016. © 2016 Society of Plastics Engineers
Characterization of the Thermal Response of Munitions in Storage Exposed to Real and Arbitrary Weather Conditions
Authors: Blecker Ken , Hadim Hamid
Published: January 2016

The objective of this investigation is to characterize the thermal response of stored munitions exposed to real weather conditions in order to validate current test procedures as well as develop the ability to provide an estimate of the thermal exposure over the lifecycle of a munition. Currently, the thermal history of munitions in storage cannot be determined without continuous monitoring of individual items and there is no method to provide a detailed estimate of the exposure by analyzing existing data when continuous data was not collected. This work describes the experimental and initial numerical investigations of instrumented munitions in storage to characterize their thermal response. The numerical model has the capability to validate broad trends observed from the experimental data. For this investigation, data is being collected through field experiments of inert munitions instrumented with thermocouples that are collocated near a weather station. Data from field experiments are used to develop and validate the numerical model. The numerical model will save time and resources in future investigations of the thermal exposure of munitions in storage as well as advance the understanding of the implications of selecting a long term storage environment. At a fundamental research level, this work contributes to the advances in combined heat transfer by natural convection and radiation inside a 3D enclosure combined with external forced convection and radiation. The numerical model includes several features including heat transfer to the enclosure by solar radiation, conduction, and forced convection, heat transfer between the enclosure container walls and the projectiles by radiation, conduction, and natural convection, heat transfer within the projectile by conduction, distributed thermal energy storage in projectiles, and transient temperature boundary condition at the enclosure walls.
Thermoanalytical Investigation of Some Binary Pyrotechnic Mixtures of Ammonium Azide as Chemical Gas Generating Systems
Authors: Hosseini Seyed Ghorban , Eslami Abbas
Published: January 2016

The conventional NaN3/oxidants gas generator pyrotechnic mixtures suffer from leaving undesirable solid residues. The presented investigation aimed to overcome this problem through mixing of NH4N3 particles with some metallic components, and to introduce some new gas generator pyrotechnic mixtures. In this work, volatile ammonium azide particles were initially stabilized via microencapsulation technique, and blended with Zr, Ti, ZrH2, and TiH2 powders to produce different gas generation mixtures. Thermal properties and kinetic parameters of these pyrotechnic mixtures were investigated by using thermal analysis (TG/DTA and DSC) techniques. The apparent activation energy (E), ΔG#, ΔH#, ΔS#, and critical ignition temperature (Tb) of the ignition processes of the mixtures were obtained from the DSC experiments. Among the investigated mixtures, NH4N3/ZrH2 composition was found to show desirable efficiency, and also it can be considered as a safe pyrotechnic composition for gas generation property, due to its moderate ignition temperature.
Effects of Aluminum Content on TNT Detonation and Aluminum Combustion using Electrical Conductivity Measurements
Authors: Zhou Zhen Qing , Nie Jian Xing , Zeng Liang , Jin Zhao Xin , Jiao Qing Jie
Published: January 2016

To improve the understanding how aluminum contributes in non‐ideal explosive mixtures, cast‐cured formulations were analyzed in a series of electrical conductivity experiments. Five types of TNT‐based aluminized explosives, with aluminum mass fractions from 0 % to 20 % were considered in this study. The electrical conductivity of the detonation products in aluminized explosives was measured using an improved conductivity measurement method. The conductivity measurement results show that the detonation process of TNT‐based aluminized explosives can be divided into two stages: the first stage is the detonation reaction of TNT, and the second stage is the combustion reaction of aluminum with the detonation products. In the first stage, the duration of the TNT detonation increases with increased aluminum content; examination of the peak conductivities of the explosives with various aluminum contents indicated that a higher aluminum content is associated with a lower peak conductivity. Additionally, the ignition time of Al in the second stage is also determined. This work not only presents a means for studying the detonation process of aluminized explosives at 0–2.21 μs, but it also verified the relationship between the aluminum content and electrical conductivity in detonation products.
Characterization of Granular and Polymer‐Embedded RDX Grades: Floret Tests
Authors: van der Heijden Antoine E. D. M. , Bouma Richard H. B.
Published: January 2016

In an attempt to further contribute to the characterization of explosive compositions, small scale Floret tests were performed using four RDX grades, differing in product quality. A Floret test provides a measure – by indentation of a copper block – of detonation spreading or the initiability and shock wave divergence and is applied in particular to explosives used in initiation trains. Both as‐received RDX and PBXs (based on the AFX‐757 composition, a hard target penetrator explosive) containing these RDX grades were tested in the Floret test set‐up. It was found that the Floret test method, when applied to granular, as‐received RDX, was not able to discriminate between the overall RDX product qualities on the basis of the resulting volume of the indentation in the copper block. For the Floret test data of the PBX samples, a division into two parts, where one of the RDX lots shows a lower dent volume compared to the other RDX lots tested. Based on the results presented in this paper with granular RDX and a PBX composition and earlier results with a different type of PBX (based on PBXN‐109, an insensitive high explosive used in a wide range of munitions), the Floret test could be developed into a screening test for shock sensitivity and product quality, without the need for complex and large volume casting of specific PBX compositions.
Synthesis of CL‐20 by a Greener Method Using Nitroguanidine/HNO3
Authors: Bayat Yadollah , Hajighasemali Fatemeh
Published: January 2016

CL‐20 is a nitramine applied in both explosives and propellants. The traditional nitrolysis of tetraacetyldibenzylhexaazaisowurtzitane (TADB), as the key precursor for the synthesis of CL‐20, requires the use of N2O4/HNO3/H2SO4 (so‐called mixed acid) which has its drawbacks, especially at industrial scales. Herein, the nitrolysis of TADB with a one pot method was investigated using nitroguanidine (NQ) and guanidinium nitrate (GN)/HNO3 as new system for the synthesis of CL‐20. Positive features of these nitro‐debenzylation/nitro‐deacetylation methods include lack of mixed acids, simple work‐up and less hazardous reagents. The maximum yield of reaction (72 %) was obtained under optimized conditions (NQ (3.48 mmol) and TADB (0.58 mmol) in 98 % HNO3 (5 mL) at 85 °C and 24 h).
Comparison of the peptide binding preferences of three closely related TRAF paralogs: TRAF2, TRAF3, and TRAF5
Authors: Foight Glenna Wink , Keating Amy E.
Published: January 2016

Tumor necrosis factor receptor‐associated factors (TRAFs) constitute a family of adapter proteins that act in numerous signaling pathways important in human biology and disease. The MATH domain of TRAF proteins binds peptides found in the cytoplasmic domains of signaling receptors, thereby connecting extracellular signals to downstream effectors. Beyond several very general motifs, the peptide binding preferences of TRAFs have not been extensively characterized, and differences between the binding preferences of TRAF paralogs are poorly understood. Here we report a screening system that we established to explore TRAF peptide‐binding specificity using deep mutational scanning of TRAF‐peptide ligands. We displayed single‐ and double‐mutant peptide libraries based on the TRAF‐binding sites of CD40 or TANK on the surface of Escherichia coli and screened them for binding to TRAF2, TRAF3, and TRAF5. Enrichment analysis of the library sequencing results showed differences in the permitted substitution patterns in the TANK versus CD40 backgrounds. The three TRAF proteins also demonstrated different preferences for binding to members of the CD40 library, and three peptides from that library that were analyzed individually showed striking differences in affinity for the three TRAFs. These results illustrate a previously unappreciated level of binding specificity between these close paralogs and demonstrate that established motifs are overly simplistic. The results from this work begin to outline differences between TRAF family members, and the experimental approach established herein will enable future efforts to investigate and redesign TRAF peptide‐binding specificity.
The typical‐state paradox: diagnosing horizons with complexity
Authors: Susskind Leonard
Published: January 2016

The concept of transparent and opaque horizons is defined. One example of opaqueness is the presence of a firewall. Two apparently contradictory statements are reconciled: The overwhelming number of black hole states have opaque horizons; and: All black holes formed by natural processes have transparent horizons. A diagnostic is proposed for transparency, namely that the computational complexity of the state be increasing with time. It is shown that opaque horizons are extremely unstable and that the slightest perturbation will make them transparent within a scrambling time.
Computational complexity and black hole horizons
Authors: Susskind Leonard
Published: January 2016

Computational complexity is essential to understanding the properties of black hole horizons. The problem of Alice creating a firewall behind the horizon of Bob's black hole is a problem of computational complexity. In general we find that while creating firewalls is possible, it is extremely difficult and probably impossible for black holes that form in sudden collapse, and then evaporate. On the other hand if the radiation is bottled up then after an exponentially long period of time firewalls may be common. It is possible that gravity will provide tools to study problems of complexity; especially the range of complexity between scrambling and exponential complexity.
Non‐Thermal Corrections to Hawking Radiation Versus the Information Paradox**
Authors: Dvali Gia
Published: January 2016

We provide a model‐independent argument indicating that for a black hole of entropy N the non‐thermal deviations from Hawking radiation, per each emission time, are of order , as opposed to . This fact abolishes the standard a priory basis for the information paradox.
Entanglement entropy in a holographic Kondo model
Authors: Erdmenger Johanna , Flory Mario , Hoyos Carlos , Newrzella Max‐Niklas , Wu Jackson M. S.
Published: January 2016

We calculate entanglement and impurity entropies in a recent holographic model of a magnetic impurity interacting with a strongly coupled system. There is an RG flow to an IR fixed point where the impurity is screened, leading to a decrease in impurity degrees of freedom. This information loss corresponds to a volume decrease in our dual gravity model, which consists of a codimension one hypersurface embedded in a BTZ black hole background in three dimensions. There are matter fields defined on this hypersurface which are dual to Kondo field theory operators. In the large N limit, the formation of the Kondo cloud corresponds to the condensation of a scalar field. The entropy is calculated according to the Ryu‐Takayanagi prescription. This requires to determine the backreaction of the hypersurface on the BTZ geometry, which is achieved by solving the Israel junction conditions. We find that the larger the scalar condensate gets, the more the volume of constant time slices in the bulk is reduced, shortening the bulk geodesics and reducing the impurity entropy. This provides a new non‐trivial example of an RG flow satisfying the g‐theorem. Moreover, we find explicit expressions for the impurity entropy which are in agreement with previous field theory results for free electrons. This demonstrates the universality of perturbing about an IR fixed point.
Injection in light beam induced current systems: An analytical model
Authors: Micard Gabriel , Hahn Giso , Terheiden Barbara
Published: January 2016

In LBIC systems, the evaluation of the injection level is necessary when operating in low injection for defect recombination studies or in defined standard illumination conditions (one or several suns for concentrator applications) for quantum efficiency evaluation. We demonstrate in this contribution that evaluating the laser beam induced injection based on uniform illumination condition can lead to several decades of error because of the lateral carrier diffusion. Based on a parallel beam approximation, we propose here an analytical model to evaluate the maximum of injection of a laser with its parametrization valid for most LBIC system settings and material quality. State of the art high resolution LBIC (HR‐LBIC) systems have so sharply focused laser beams that the beam divergence cannot be neglected anymore in the injection calculation. Although providing a quantitative criterion to determine whether the beam divergence can be neglected, we provide a more advanced model for describing the injection of the laser that includes beam divergence.
Enhanced stability of P3HT/poly‐crystalline Si thin film hybrid solar cells
Authors: Zellmeier M. , Kühnapfel S. , Rech B. , Nickel N. H. , Rappich J.
Published: January 2016

Hybrid solar cells have been fabricated from solution processing of poly‐(3‐hexylthiophen‐2,5‐diyl) onto planar poly‐crystalline thin film silicon (poly‐Si) absorbers on glass. The poly‐Si layers were prepared by laser crystallization. Methyl passivation of the poly‐Si surface by a one‐step grafting process via methyl‐Grignard enabled open circuit voltages of up to 552 mV and an overall power conversion efficiency of 6.6% for this device type. The solar cell exhibited significant advantages compared to the wafer‐based counterparts. The inverted device structure of the thin film cell lead to an enhancement of the quantum efficiency since the back side contacted cell had less light absorption and reflection losses due to the gold layer which was used as front contact for the c‐Si‐based hybrid solar cell. As a result, a photo current of 24.3 mA cm−2 was obtained for a 10 μm thin poly‐Si layer on glass. Furthermore, the inverted device structure showed a pronounced increase in stability due to the much thicker gold back contact that reduces the diffusion of water and oxygen toward the polymer layer. After 3 months in ambient air, this type of solar cell operated with 86% of its initial efficiency.
Study on the crystallization behavior of nitrogen‐doped SbSe films for PCRAM applications
Authors: Park Jun Hyuk , Jeong Jin Hwan , Choi Doo Jin
Published: January 2016

In this paper, the crystallization behavior of nitrogen‐doped SbSe films was investigated as a function of nitrogen content. We found that the SET resistance and crystallization temperature of nitrogen‐doped SbSe films were higher than those of un‐doped SbSe films. Moreover, the crystallinity and average grain area decreased with increasing nitrogen content because of the formation of nitrides, which disturbed crystal growth. Theoretical modeling was conducted to verify the effects of nitrogen doping, and the results were in good agreement with the experimental results. Through the optical band gap measurement, we found that nitrogen doping is an effective method for improving amorphous stability and reducing RESET current. In addition, the newly formed nitrides improved the chemical composition stability by suppressing element loss. After optimizing the nitrogen contents, nitrogen‐doped SbSe films are expected to be promising materials for PCRAM applications.
Assessing of Flexible Packaging Integrity: Using the Aerosolization Bacteria
Authors: Moghimi Nastaran , Kim Sun‐Jong , Park Su‐il
Published: January 2016

Package integrity is a critical factor to ensure that product sterility is maintained over its entire shelf life. An exposure chamber method was developed to determine the integrity of flexible packaging systems, i.e. flexible multilayer linear low‐density polyethylene/nylon pouches with a 100, 50, 25 or 15 µm micro‐channel with 5 mm length defect in the sealing area. Viable cells ofStaphylococcus aureusandEscherichia colihave been utilized as model organisms. The aerosol was generated by a nebulizer, about 2.0 × 107 CFU m−3concentration inside the test chamber. The results demonstrated that defect pouches with a 100, 50 or 25 µm channel leakage exposed to microbiologically challenging conditions could not maintain the sterility of their contents. Micro‐channels with 15 µm diameter can be detected as the critical micro‐channel dimension for bacterial penetration for flexible pouches. Copyright © 2016 John Wiley & Sons, Ltd.
The Climate‐system Historical Forecast Project: do stratosphere‐resolving models make better seasonal climate predictions in boreal winter?
Authors: Butler Amy H. , Arribas Alberto , Athanassiadou Maria , Baehr Johanna , Calvo Natalia , Charlton‐Perez Andrew , Déqué Michel , Domeisen Daniela I. V. , Fröhlich Kristina , Hendon Harry , Imada Yukiko , Ishii Masayoshi , Iza Maddalen , Karpechko Alexey Yu. , Kumar Arun , MacLachlan Craig , Merryfield William J. , Müller Wolfgang A. , O'Neill Alan , Scaife Adam A. , Scinocca John , Sigmond Michael , Stockdale Timothy N. , Yasuda Tamaki
Published: January 2016

Using an international, multi‐model suite of historical forecasts from the World Climate Research Programme (WCRP) Climate‐system Historical Forecast Project (CHFP), we compare the seasonal prediction skill in boreal wintertime between models that resolve the stratosphere and its dynamics (‘high‐top’) and models that do not (‘low‐top’). We evaluate hindcasts that are initialized in November, and examine the model biases in the stratosphere and how they relate to boreal wintertime (December–March) seasonal forecast skill. We are unable to detect more skill in the high‐top ensemble‐mean than the low‐top ensemble‐mean in forecasting the wintertime North Atlantic Oscillation, but model performance varies widely. Increasing the ensemble size clearly increases the skill for a given model. We then examine two major processes involving stratosphere–troposphere interactions (the El Niño/Southern Oscillation (ENSO) and the Quasi‐Biennial Oscillation (QBO)) and how they relate to predictive skill on intraseasonal to seasonal time‐scales, particularly over the North Atlantic and Eurasia regions. High‐top models tend to have a more realistic stratospheric response to El Niño and the QBO compared to low‐top models. Enhanced conditional wintertime skill over high latitudes and the North Atlantic region during winters with El Niño conditions suggests a possible role for a stratospheric pathway.
Euler equation for descriptors of the spherically symmetric coulomb systems
Authors: Nagy Ágnes
Published: January 2016

Euler equations for a family of descriptors of the spherically symmetric Coulomb systems are derived and discussed. Generalized Weizsäcker and Pauli energies and potentials are introduced. © 2016 Wiley Periodicals, Inc.
Monitoring structural evolution of organosilicate species during sol–gel processes by electrospray ionization mass spectrometry
Authors: Li Jun , Chen Lei
Published: January 2016

Rationale

Electrospray ionization mass spectrometry (ESI‐MS) has been employed to study species distribution in controlled acid‐catalyzed hydrolysis and condensation of (3‐chloropropyl)trimethoxysilane (CPTMS), which is frequently used in the synthesis of hybrid silica‐based materials.

Methods

The conditions of analysis for reaction products, i.e. organosilicate oligomers, were optimized by using various capillary temperatures and solute concentrations. The structures of organosilicate oligomers were shown to vary with reaction duration and the molar ratio of water to siloxane (r), with multiple types of oligomers attributed to linear, cyclic and hydroxylated species.

Results

The evolution of oligomeric structures was elucidated from the ESI‐MS spectra. The number and intensity of cyclic oligomers increase with an increase in the r‐value or reaction length, at the expense of linear species, indicating the trend to formation of cross‐linked polysiloxane structures.

Conclusions

Overall, this work demonstrates that ESI‐MS is an indispensable tool for the comprehensive characterization of the correlation between properties and structure of hybrid silica‐based materials. Copyright © 2016 John Wiley & Sons, Ltd.
Rapid detection of water buffalo ricotta adulteration or contamination by matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry
Authors: Russo Rosita , Rega Camilla , Chambery Angela
Published: January 2016

Rationale

The improvement and development of novel technologies and analytical tools are an important first line of defence for both detecting and deterring food frauds. In order to protect the authenticity of traditional foods and safeguard geographical indications and traditional specialities at European level, Protected Designation of Origin (PDO) legislation has been introduced as a guarantee of quality (Council Regulation ECC 2081/92). Dairy products, especially those certified as PDO products, are amongst the most common targets of fraudulent activities. Recently, the buffalo ricotta, a dairy product exclusively made with buffalo milk and produced in the same geographical area of most widely known buffalo mozzarella, has gained PDO recognition.

Methods

In the present work, a fast and simple matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS)‐based methodology has been developed for detecting the adulteration or contamination of buffalo ricotta with bovine milk.

Results

We optimized a fast procedure for digesting milk proteins and identified a novel specific proteotypic marker, corresponding to region 149‐162 of β‐lactoglobulin, as highly diagnostic for the presence of cow milk within ricotta matrices.

Conclusions

By exploiting the advantages of MALDI‐TOFMS, the proposed methodology represents a useful tool for the assessment of buffalo ricotta authenticity and to guarantee the PDO certification against frauds. Copyright © 2016 John Wiley & Sons, Ltd.
Deamidation reactions of protonated asparagine and glutamine investigated by ion spectroscopy
Authors: Kempkes Lisanne J. M. , Martens Jonathan K. , Grzetic Josipa , Berden Giel , Oomens Jos
Published: January 2016

Rationale

Deamidation of Asn and Gln residues is a primary route for spontaneous post‐translational protein modification. Several structures have been proposed for the deamidation products of the protonated amino acids. Here we verify these structures by ion spectroscopy, as well as the structures of parallel and sequential fragmentation products.

Methods

Infrared ion spectroscopy using the free electron laser FELIX has been applied to the reaction products from deamidation of protonated glutamine and asparagine in a tandem mass spectrometer. IR spectra were recorded over the 800–1900 cm−1 spectral range by infrared multiple‐photon dissociation (IRMPD) spectroscopy. Molecular structures of the fragment ions are derived from comparison of the experimental spectra with spectra predicted for different candidate structures by density functional theory (DFT) calculations.

Results

[AsnH+ – NH3]+ is found to possess a 3‐aminosuccinic anhydride structure protonated on the amino group. The dissociation reaction involving loss of H2O and CO forms a linear immonium ion. For [GlnH+–NH3]+, the N‐terminal nitrogen acts as the nucleophile leading to an oxo‐proline product ion structure. For [GlnH+–NH3]+, a sequential loss of [CO + H2O] is found, leading to a pyrolidone‐like structure. We also confirm by IR spectroscopy that dehydration of protonated aspartic acid (AspH+) and glutamic acid (GluH+) leads to identical structures as to those found for the loss of NH3 from AsnH+ and GlnH+.

Conclusions

The structure determined for AsnH+ is in agreement with the suggested structure derived from measured and computed activation energies. IR ion spectra for the NH3‐loss product from GlnH+ establish that a different reaction mechanism occurs for this species as compared to AsnH+. For both amino acids, loss of NH3 occurs from the side chain. Copyright © 2016 John Wiley & Sons, Ltd.
Fukushima Daiichi reactor source term attribution using cesium isotope ratios from contaminated environmental samples
Authors: Snow Mathew S. , Snyder Darin C. , Delmore James E.
Published: January 2016

Rationale

Source term attribution of environmental contamination following the Fukushima Daiichi Nuclear Power Plant (FDNPP) disaster is complicated by a large number of possible similar emission source terms (e.g. FDNPP reactor cores 1–3 and spent fuel ponds 1–4). Cesium isotopic analyses can be utilized to discriminate between environmental contamination from different FDNPP source terms and, if samples are sufficiently temporally resolved, potentially provide insights into the extent of reactor core damage at a given time.

Methods

Rice, soil, mushroom, and soybean samples taken 100–250 km from the FDNPP site were dissolved using microwave digestion. Radiocesium was extracted and purified using two sequential ammonium molybdophosphate‐polyacrylonitrile columns, following which 135Cs/137Cs isotope ratios were measured using thermal ionization mass spectrometry (TIMS). Results were compared with data reported previously from locations to the northwest of FDNPP and 30 km to the south of FDNPP.

Results

135Cs/137Cs isotope ratios from samples 100–250 km to the southwest of the FDNPP site show a consistent value of 0.376 ± 0.008. 135Cs/137Cs versus 134Cs/137Cs correlation plots suggest that radiocesium to the southwest is derived from a mixture of FDNPP reactor cores 1, 2, and 3. Conclusions from the cesium isotopic data are in agreement with those derived independently based upon the event chronology combined with meteorological conditions at the time of the disaster.

Conclusions

Cesium isotopic analyses provide a powerful tool for source term discrimination of environmental radiocesium contamination at the FDNPP site. For higher precision source term attribution and forensic determination of the FDNPP core conditions based upon cesium, analyses of a larger number of samples from locations to the north and south of the FDNPP site (particularly time‐resolved air filter samples) are needed. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.
Analysis of nitrogen‐based explosives with desorption atmospheric pressure photoionization mass spectrometry
Authors: Kauppila T. J. , Flink A. , Pukkila J. , Ketola R. A.
Published: January 2016

Rationale

Fast methods that allow the in situ analysis of explosives from a variety of surfaces are needed in crime scene investigations and home‐land security. Here, the feasibility of the ambient mass spectrometry technique desorption atmospheric pressure photoionization (DAPPI) in the analysis of the most common nitrogen‐based explosives is studied.

Methods

DAPPI and desorption electrospray ionization (DESI) were compared in the direct analysis of trinitrotoluene (TNT), trinitrophenol (picric acid), octogen (HMX), cyclonite (RDX), pentaerythritol tetranitrate (PETN), and nitroglycerin (NG). The effect of different additives in DAPPI dopant and in DESI spray solvent on the ionization efficiency was tested, as well as the suitability of DAPPI to detect explosives from a variety of surfaces.

Results

The analytes showed ions only in negative ion mode. With negative DAPPI, TNT and picric acid formed deprotonated molecules with all dopant systems, while RDX, HMX, PETN and NG were ionized by adduct formation. The formation of adducts was enhanced by addition of chloroform, formic acid, acetic acid or nitric acid to the DAPPI dopant. DAPPI was more sensitive than DESI for TNT, while DESI was more sensitive for HMX and picric acid.

Conclusions

DAPPI could become an important method for the direct analysis of nitroaromatics from a variety of surfaces. For compounds that are thermally labile, or that have very low vapor pressure, however, DESI is better suited. Copyright © 2016 John Wiley & Sons, Ltd.
Invasive tracheobronchial aspergillosis progressing from bronchial to diffuse lung parenchymal lesions
Authors: Ohta Hiromitsu , Yamazaki Susumu , Miura You , Kanazawa Minoru , Sakai Fumikazu , Nagata Makoto
Published: January 2016

Invasive tracheobronchial aspergillosis that is entirely limited or predominantly confined to tracheobronchial lesions is a relatively rare form of invasive pulmonary aspergillosis. Extended parenchymal opacities that are radiological manifestations of invasive aspergillosis sometimes occur following invasive tracheobronchial aspergillosis. However, it remains unclear whether or not invasive tracheobronchial aspergillosis is the initial stage of invasive pulmonary aspergillosis. A 61‐year‐old woman was admitted because of severe diarrhea and dehydration. Three days after admission, she complained of dyspnea. A computed tomography (CT) scan of the chest showed bronchial wall thickening. She developed respiratory failure despite antibiotic therapy. A CT scan showed obstructions of bronchial lumens and bronchiectasis in the right upper lobe. Aspergillus fumigatus was identified from samples obtained in bronchoscopic examination. Bronchial lesions rapidly progressed to be extended. Aspergillus infection with multiple parenchymal opacities was observed on CT scan. She responded to treatment with antifungal drugs.
Effects of hydrocolloids on acorn starch physical properties
Authors: Saleh Mohammed , Ajo Radwan , Al‐Ismail Khalid , Ondier George
Published: January 2016

The effect of hydrocolloids (arabic gum, carrageenan, carboxymethyl cellulose, and xanthan gum) on the physical properties of acorn starch was investigated. First order mixture response surface model was used and the effects of 1% hydrocolloids on acorn starch water holding capacity, starch solution viscosity, gel strength, freeze–thaw stability, and pasting properties were evaluated. Contributions of each hydrocolloid on determining acorn starch functionality were also calculated. Hydrocolloid combinations significantly (p < 0.05) decrease acorn starch water holding capacity held at 23.3°C from 213.6% of 100% starch to less than 208.3% with minor exceptions. The increase in holding temperature, however, increased water holding capacity (WHC) irrespective of the hydrocolloids set used. The flow behavior indices of treatments ranged from 0.43 to 0.99 and were significantly (p < 0.05) greater than that of pure acorn starch (i.e., 0.66) for most treatments. The consistency coefficient of treatments were significantly (p < 0.05) greater than that of the control and were best fit for the shear‐thickening model. Significant (p < 0.05) improvement in gel strength and decrease in freeze–thaw stability of treatments compared to the control was also reported. The pasting properties of treatments increased with the use of hydrocolloids, thus showing the significant role of hydrocolloids in dictating the pasting characteristics of the acorn–hydrocolloids interaction.
Recognize strategies for killing change, use them to your advantage to create change
Authors: Hope Joan
Published: January 2016

HOLLYWOOD, FLA. — If you've ever tried to lead change on campus, you probably encountered resistance. Faculty members are the experts in their fields, and many think their expertise carries over to other areas, said Loralyn Taylor, Ph.D., director of analytics for student success initiatives at Ohio University. Faculty members function as individuals rather than members of a team. And to the extent they see themselves as part of a team, they identify more with their discipline than with their department and more with their department than with the university.
Use Bloom's Taxonomy to assess levels of learning
Authors: Rainsberger Richard
Published: January 2016

OK, you've developed a great FERPA Basics training program. The question now becomes: Have you succeeded in transferring the knowledge to your participants so that they not only know what FERPA is about but can actually use what they've learned in their professional lives on campus? In other words, do they know how to make FERPA‐compliant decisions?
Two‐dimensional visualization and measurement of the fetal optic chiasm: improving counseling for antenatal diagnosis of agenesis of the septum pellucidum
Authors: Viñals F. , Ruiz P. , Correa F. , Gonçalves Pereira P.
Published: January 2016

Objective

To develop an objective method for visualizing and measuring the fetal optic chiasm (OC) using transvaginal two‐dimensional (2D) ultrasound in the coronal plane and to report measurements in fetuses with agenesis of the septum pellucidum (SP).

Methods

This was a prospective cross‐sectional study of 115 morphologically normal fetuses in low‐risk pregnancies, between 21 and 30 weeks' gestation. The OC was measured in a coronal plane at the level of the third ventricle and was seen as a horizontally aligned dumbbell‐shaped structure of moderate echogenicity. In addition, OC measurements from eight fetuses with agenesis of the SP and complete follow‐up were compared with the reference range.

Results

OC measurements were obtained in 110/115 normal fetuses and showed that OC increases linearly with gestational age. Our method of measurement demonstrated good intraobserver repeatability and excellent interobserver reproducibility. Among the eight fetuses with agenesis of the SP, five had normal OC measurements and five had normal vision postnatally. Pregnancy continued to term in all cases and the follow‐up period varied from 6 months to 7 years.

Conclusion

Our study demonstrates that it is possible to visualize and measure the OC directly on a 2D ultrasound coronal plane. In fetuses with agenesis of the SP, the morphology and width of the OC visual pathway could prove a relevant tool for assessing its development. It would also help in the difficult task of providing antenatal counseling when faced with the diagnosis of agenesis of the SP. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Fetal growth is associated with first‐trimester maternal vascular function
Authors: Iacobaeus C. , Kahan T. , Jörneskog G. , Bremme K. , Thorsell M. , Andolf E.
Published: January 2016

Objective

To investigate the relationship between maternal endothelial function in the first trimester, assessed in both the brachial artery and the forearm skin microcirculation, and fetal growth.

Methods

Vascular function was assessed in 56 pregnant women during gestational weeks 11–14. Vascular reactivity in the brachial artery was evaluated by postischemic hyperemia‐induced flow‐mediated vasodilatation (FMD) and by vasodilatation following administration of sublingual glyceryl trinitrate (GTN). Forearm skin microcirculation was investigated by laser Doppler perfusion imaging during iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to assess endothelium‐dependent and ‐independent microvascular vasodilatation, respectively. Fetal growth was measured at study inclusion and birth‐weight centile was calculated after delivery.

Results

FMD and GTN‐induced vasodilatation were both associated with birth‐weight centile. On multivariate analysis (adjusted for brachial artery diameter at rest, blood pressure, maternal age and heart rate), for FMD β = 1.7 (95% CI, 0.06–3.34), r2 = 0.26 and P = 0.042, and for GTN‐induced vasodilatation β = 2.6 (95% CI, 0.44–4.68), r2 = 0.15 and P = 0.02. Endothelium‐dependent and ‐independent microvascular reactivity were also associated with birth‐weight centile: for ACh β = 7.82 (95% CI, 1.81–13.83), r2 = 0.12 and P = 0.029, and for SNP β = 6.27 (95% CI, 1.20–11.34), r2 = 0.11 and P = 0.016.

Conclusion

First‐trimester maternal vascular dilatation capacity (rather than endothelial function alone) is associated with fetal growth. These findings were consistent in both the brachial artery and the forearm skin microcirculation. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Managing pregnancy of unknown location based on initial serum progesterone and serial serum hCG levels: development and validation of a two‐step triage protocol
Authors: Van Calster B. , Bobdiwala S. , Guha S. , Van Hoorde K. , Al‐Memar M. , Harvey R. , Farren J. , Kirk E. , Condous G. , Sur S. , Stalder C. , Timmerman D. , Bourne T.
Published: January 2016

Objectives

A uniform rationalized management protocol for pregnancies of unknown location (PUL) is lacking. We developed a two‐step triage protocol to select PUL at high risk of ectopic pregnancy (EP), based on serum progesterone level at presentation (step 1) and the serum human chorionic gonadotropin (hCG) ratio, defined as the ratio of hCG at 48 h to hCG at presentation (step 2).

Methods

This was a cohort study of 2753 PUL (301 EP), involving a secondary analysis of prospectively and consecutively collected PUL data from two London‐based university teaching hospitals. Using a chronological split we used 1449 PUL for development and 1304 for validation. We aimed to assign PUL as low risk with high confidence (high negative predictive value (NPV)) while classifying most EP as high risk (high sensitivity). The first triage step assigned PUL as low risk using a threshold of serum progesterone at presentation. The remaining PUL were triaged using a novel logistic regression risk model based on hCG ratio and initial serum progesterone (second step), defining low risk as an estimated EP risk of < 5%.

Results

On validation, initial serum progesterone ≤ 2 nmol/L (step 1) classified 16.1% PUL as low risk. Second‐step classification with the risk model selected an additional 46.0% of all PUL as low risk. Overall, the two‐step protocol classified 62.1% of PUL as low risk, with an NPV of 98.6% and a sensitivity of 92.0%. When the risk model was used in isolation (i.e. without the first step), 60.5% of PUL were classified as low risk with 99.1% NPV and 94.9% sensitivity.

Conclusion

PUL can be classified efficiently into being either high or low risk for complications using a two‐step protocol involving initial progesterone and hCG levels and the hCG ratio. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Evaluation of the kinetics of anti‐NP and anti‐HA antibody after infection of Pekin ducks with low pathogenic avian influenza virus
Authors: Marché Sylvie , van den Berg Thierry , Lambrecht Bénédicte
Published: January 2016

Serological monitoring is a feature of surveillance programmes for the detection of the circulation of notifiable low pathogenic avian influenza (LPAI) viruses in commercial poultry holdings. Commercial multispecies nucleoprotein (NP) enzyme‐linked immunosorbent assays (ELISAs) have been replacing the haemagglutination inhibition (HI) test as pre‐screening tools. Few comparative studies have been conducted to test sera from domestic ducks for diagnostic purposes. Therefore, we evaluated the correlation between commercial NP ELISAs and the HI test. Anti‐NP and anti‐haemagglutinin (HA) antibodies were measured in sera from domestic ducks that had undergone serological screening and from juvenile domestic Pekin ducks that were experimentally infected with LPAI viruses. The findings highlight an absence of a correlation between NP ELISA and HI results with both field and experimental duck sera. Dissimilar kinetics of the antibodies detected during the follow‐up evaluation of the humoral immune responses in experimentally infected ducks may explain this lack of correlation. Indeed, anti‐NP titres decreased over time, whereas anti‐HA titres remained unchanged after inoculation with the H3N1 LPAI virus isolated from domestic duck or the H7N1 LPAI virus isolated from chicken. Despite these differences, the NP ELISA may serve as a valid pre‐screening tool to detect circulating LPAI viruses in domestic duck populations at the flock level.
Management of antithrombotic therapy during cardiac implantable device surgery
Authors: AlTurki Ahmed , Proietti Riccardo , Birnie David H. , Essebag Vidal
Published: January 2016

Anticoagulants are commonly used drugs that are frequently encountered during device placement. Deciding when to halt or continue the use of anticoagulants is a balance between the risks of thromboembolism versus bleeding. Patients taking warfarin with a high risk of thromboembolism should continue to take their warfarin without interruption during device placement while ensuring their international normalized ratio remains below 3. For patients who are taking warfarin and have low risk of thromboembolism, either interrupted or continued warfarin may be used, with no evidence to clearly support either strategy. There is little evidence to support continuing direct acting oral anticoagulants (DOACs) for device implantation. The timing of halting these medications depends largely on renal function. If bleeding occurs, warfarin's anticoagulation effect is reversible with vitamin K and activated prothrombin complex concentrate. There are no DOAC reversal agents currently available, but some are under development. Regarding antiplatelet agents, aspirin alone can be safely continued while clopidogrel alone may also be continued, but with a slightly higher bleeding risk. Dual antiplatelet therapy for bare‐metal stent/drug‐eluting stent implanted within 4 weeks/6 months, respectively, should be continued due to high risk of stent thrombosis; however, if they are implanted after this period, then clopidogrel can be halted 5 days before the procedure and resumed soon after, while aspirin is continued. If the patient is taking both aspirin and warfarin, aspirin should be halted 5 days prior to the procedure, while warfarin is continued.
Targeting translation: eIF4E as an emerging anticancer drug target
Authors: Lu Chunwan , Makala Levi , Wu Daqing , Cai Yafei
Published: January 2016

The translation initiation factor eIF4E mediates a rate-limiting process that drives selective translation of many oncongenic proteins such as cyclin D1, survivin and VEGF, thereby contributing to tumour growth, metastasis and therapy resistance. As an essential regulatory hub in cancer signalling network, many oncogenic signalling pathways appear to converge on eIF4E. Therefore, targeting eIF4E-mediated cap-dependent translation is considered a promising anticancer strategy. This paper reviews the strategies that can be used to target eIF4E, highlighting agents that target eIF4E activity at each distinct level.
Potential Misclassification of Urinary Tract–Related Bacteremia Upon Applying the 2015 Catheter-Associated Urinary Tract Infection Surveillance Definition From the National Healthcare Safety Network
Authors: Greene M. Todd , Ratz David , Meddings Jennifer , Fakih Mohamad G. , Saint Sanjay
Published: January 2016

The Centers for Disease Control and Prevention recently updated the surveillance definition of catheter-associated urinary tract infection to include only urine culture bacteria of at least 1×105 colony-forming units/mL. Our findings suggest that the new surveillance definition may fail to capture clinically meaningful catheter-associated urinary tract infections.

Infect. Control Hosp. Epidemiol. 2016;37(4):469–471
The effectiveness of cognitive behavioural therapy for pain in childhood and adolescence: a meta-analytic review
Authors: Lonergan A.
Published: January 2016

Objectives

A variety of chronic painful conditions are present in the paediatric population. Patients with chronic pain often experience considerable scepticism and avoidance by health care providers. This meta-analytic review aimed to utilise well-designed studies, in examining the effectiveness of cognitive behavioural therapy (CBT) in the treatment of chronic pain in children and adolescents.

Methods

Nine randomized controlled trial studies examining CBT for chronic pain were reviewed. Outcome measures were child reported pain intensity, pain duration and functional disability.

Results

CBT had a large effect on pain intensity for recurrent abdominal pain (RAP), a small effect on headaches, and a medium effect on fibromyalgia. CBT had a medium effect on pain duration across pain types. CBT had a large effect on functional disability for RAP, a small effect on fibromyalgia and a moderate effect on headaches. Findings are limited by the small number of studies and varied control conditions.

Conclusions

CBT may be effective in reducing child reported pain symptomology. Future studies using a larger sample and examining the differential impact of varied control conditions are needed.