bluuebunny/crossref_metadata_2025 huggingface dataset:
UWB antenna size reduction methods using fractal, matrix, and serrated structures
Authors: Bounif Anis , Desmarais Alexandre , Nabki Frederic , Deslandes Dominic
Published: June 2014

Four ultrawideband monopole antennas exploiting periodicity to reduce their size are presented. Experimental results are also discussed for these antennas. The first antenna uses a fractal topology based on a hexagonal pattern. It achieves a bandwidth of 8.85 GHz from 3.65 to 12.5 GHz with a 14 × 16.52 mm2 footprint. The second antenna uses an electric‐magnetic‐electric matrix and provides a 7 GHz bandwidth from 3.5 to 10.5 GHz with a 14 × 15.9 mm2 footprint. Two antennas based on a serrated structure which reduces the surface up to 15% are also presented with dimensions of 15 × 16.3 mm2: the first one covers a bandwidth of 3.5 to 11.73 GHz, whereas the second adds a notch between 5.15 to 5.825 GHz to reject the wireless LAN band. All these antennas can be incorporated into very small communication modules while maintaining excellent performances with a return loss below −10 dB and with a good multidirectional radiation pattern. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2038–2044, 2014
Analysis of lumped element periodically loaded vertical wire grid frequency selective surfaces
Authors: Mias Christos , Freni Angelo
Published: June 2014

We report how the Wait's formulation for periodically loaded wire grids can be used to analyze bandstop lumped element periodically loaded vertical wire grid frequency selective surfaces. In particular, a novel exact analytical expression for the harmonic currents is derived in the case of a lumped element of infinitesimal length. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2075–2078, 2014
How nonreciprocal is an effective permittivity matrix?
Authors: Valagiannopoulos Constantinos A.
Published: June 2014

The property of nonreciprocity in electromagnetic structures is a pivotal feature when designing useful devices such as directional phase shifters, circulators, isolators, and gyrators. The performance of these components is judged by the “nonreciprocity index,” indicating the degree of nonreciprocity. In this work, we consider a slab filled with a homogeneous anisotropic medium with an arbitrary and full permittivity matrix. The scattering parameters of the formulated four‐port network are analytically evaluated and a “nonreciprocity index” is defined. The variations of this function with respect to the complex elements of the effective permittivity matrix are shown and general conclusions are drawn. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2018–2021, 2014
A high gain broadband circular patch antenna with spiral‐shaped slot‐loaded modified ground plane
Authors: Mondal Kalyan , Sarkar Partha P.
Published: June 2014

A high gain broadband circular microstrip patch antenna with spiral shape slot‐loaded square ground plane is presented. The effects of introduction of spiral shaped slots of the square ground plane on different parameters of the antenna are studied. Maximum impedance bandwidth of 123% is obtained with modified square ground plane of size 60 × 60 mm. Highest gain achieved is 6 dBi. Simultaneously, the antenna also exhibits a compactness of 93%. The simulated results are confirmed experimentally. The proposed antenna is simple in structure and may be widely used in wireless communications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2044–2046, 2014
A compact antenna for 4G mobile handset
Authors: Jiu‐Sheng Li , Di Wu
Published: June 2014

In this article, we propose a compact antenna using S‐shaped shorted strip and inverted L‐shaped shorted strip for 4G mobile handset. The measured impedance bandwidth defined by VSWR < 3 of 750 MHz (0.66–0.81 GHz), 2.6 GHz (2.25–2.85 GHz) and 3.5 GHz (3.28–3.97 GHz) are obtained, with the peak gains of 3.0/4.7/3.6 dBi. The presented antenna has a small size of only 21 × 15 mm2 and demonstrates omnidirectional radiation patterns, which show good performance for 4G application. The measured results are in agreement with the simulation. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2199–2203, 2014
Gain enhancement and broadband using helical resonating metamaterial superstrate in stacked microstrip patch antenna
Authors: Mendhe Shridhar E. , Kosta Y. P.
Published: June 2014

Metamaterial superstrate performs unique electromagnetic properties which are used in antenna design. In this article, a novel design of stacked with parasitic element multilayer rectangular microstrip patch antenna using single layer single turn helical resonator based on metamaterial superstrate is presented. The return loss, smith chart, impedance, radiation pattern, gain, VSWR, and directivity of such an antenna are studied. The possibility of increasing bandwidth, gain and directivity of the printed patch antenna using metamaterial superstrate is examined and verified with the realized antenna. The analysis of reduction in the size of helical resonator is given and it is found that maximum reduction in size is obtained at a metallic fill ratio of 0.2. The stacked antenna is realized and successfully tested and verified measured results with the simulated results. Investigation is performed related to gain enhance using metamaterial. Percentage bandwidth of antenna is approximately 64.84% with constant gain in specified bandwidth with good cross‐polarization. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1978–1982, 2014
Polarization properties of a 2‐D split ring resonator and rod type metamaterial lens
Authors: McGillivray Duncan A. , Cravey Robin L. , Dudley Kenneth L. , Vedeler Erik , Gupta Mool C.
Published: June 2014

The polarization state of microwave (MW) radiation transmitted through a 2‐D split ring resonator and rod metamaterial (MTM) lens is investigated. At a resonance frequency of 3.63 GHz, the 2‐D lens modifies the polarization state of the incident radiation. For Ey incident polarization, the transmitted wave exhibits elliptical polarization as well as a tilt in the principal axis. The ellipticity is dependent on the incident polarization angle. A Ex polarized incident MW is unaffected. Transformation of polarization properties plays an important role for manipulation and control of MW radiation, impacting existing applications and providing opportunities for novel MTMs‐based sensors and other applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2146–2150, 2014
Comparison of two triple‐fiber sensor designs for small distance measurements
Authors: Golnabi H.
Published: June 2014

Operation of two different optical fiber sensor designs for distance measurements with a good sensitivity, resolution, and wide dynamic range is reported. Design is based on the intensity modulation due to reflectance measurement from a target surface. Two reported designs are fabricated with a triple‐fiber assembly, in which one uses a double‐transmitter, while another one uses a double‐receiver fiber design. Reflection signals from different targets are tested with these sensors and results for the mirror and A4 paper surfaces are described. The response curve for both experiments starts from a near zero level, shows a maximum at a certain distance and gradually drops to the background voltage level. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1997–2001, 2014
Design of a broadband planar monopole MIMO antenna
Authors: Kazim Jalil ur Rehman , Ahmad Salman , Ali Usman , Owais Owais
Published: June 2014

A broadband multiple‐input multiple‐output antenna with a size of 60 × 120 × 1.6 mm is presented for the smart phones. Enhanced performance of the antenna is achieved by utilizing dual radiator chopping and ground plane slitting. Supplemental L‐shaped meandered ground structure over the top of radiator was added to enhance the performance in the lower frequency band. The proposed antenna covers two frequency bands for return loss <−6 dB, that is, 0.8–0.96 and 1.7–2.7 GHz, respectively, specified for mobile phone operation. The antenna is fabricated and measured results are obtained for return loss, isolation, envelope correlation, and radiation pattern. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1994–1997, 2014
A study of the impedance and pattern bandwidths of aperture‐coupled cylindrical dielectric resonator antennas
Authors: Huynh Adam P. , Jackson David R. , Long Stuart A. , Wilton Donald R.
Published: June 2014

Aperture‐coupled cylindrical dielectric resonator antennas (DRAs) fed by a microstrip line are investigated by varying their aspect ratio and permittivity to maximize their impedance bandwidth, while maintaining an acceptable radiation pattern. Although the maximum impedance bandwidth attainable by an aperture‐coupled DRA is comparable to that of a probe‐fed one (40% vs. 45%), the maximum combined bandwidth (which also accounts for the pattern shape) is smaller—about 30% versus 45%. The study reveals a very important conclusion: while a probe feed is good for obtaining broadband DRAs that are tall or pencil‐like, an aperture‐coupled feed is more suitable for applications that require low‐profile or pancake‐like broadband DRAs. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2129–2132, 2014
Magnetization transfer from inhomogeneously broadened lines (ihMT): Experimental optimization of saturation parameters for human brain imaging at 1.5 Tesla
Authors: Girard Olivier M. , Prevost Valentin H. , Varma Gopal , Cozzone Patrick J. , Alsop David C. , Duhamel Guillaume
Published: June 2014

Purpose

Recently a new MR endogenous contrast mechanism was reported. It allows specifically imaging the magnetization transfer (MT) effect arising from inhomogeneously broadened components of the NMR spectrum, and was hence dubbed ihMT. Such unique NMR lineshape properties are presumably occurring in myelin because of its specifically ordered, multilayered sheath structure. Here, optimization of a pulsed ihMT preparation module is presented to provide guidance for future studies and improve the understanding of underlying contrast mechanisms.

Methods

This study was performed at 1.5 Tesla on healthy volunteers. A pulsed ihMT preparation was implemented in combination with a HASTE readout module. The pulse width, interpulse repetition time, total saturation duration and RF saturation power were considered for optimization of the ihMT sensitivity and contrast.

Results

An optimal configuration of the preparation module was derived, leading to 10% ihMT signal in internal capsule (relative to unsaturated data) and around 200% signal increase relative to gray matter, i.e., approximately 10‐fold superior contrast compared with conventional MT ratios, measured under similar experimental conditions.

Conclusion

Overall the ihMT sequence was robust, sensitive and very specific for white matter. These findings suggest great potential for assessing brain myelination and for better characterization of myelin related disorders. Magn Reson Med 73:2111–2121, 2015. © 2014 Wiley Periodicals, Inc.
Pattern difference of dissociated hand muscle atrophy in amyotrophic lateral sclerosis and variants
Authors: Kim Jee‐Eun , Hong Yoon‐Ho , Lee Joon‐Hyung , Ahn Suk‐Won , Kim Sung‐Min , Park Kyung‐Seok , Sung Jung‐Joon , Lee Kwang‐Woo , Seong Seung‐Yong
Published: June 2014

Introduction: Split hand is considered to be a specific feature of amyotrophic lateral sclerosis (ALS). Methods: We evaluated the pattern difference of intrinsic hand muscles of upper limb‐onset ALS (UL‐ALS), upper limb‐onset progressive muscular atrophy (UL‐PMA), brachial amyotrophic diplegia (BAD), and Hirayama disease (HD) by measuring objective electrophysiological markers. Results: The abductor digiti minimi (ADM)/abductor pollicis brevis (APB) compound muscle action potential (CMAP) amplitude ratio was significantly higher in UL‐ALS than other variants, but a considerable proportion of UL‐ALS cases had an amplitude ratio in the range of other variants. Absent APB CMAP and abnormally high ADM/APB CMAP amplitude ratio (≥4) occurred only with UL‐ALS. Conversely, an absent ADM CMAP was identified only in UL‐PMA and BAD. Conclusions: The absolute ADM/APB CMAP amplitude ratio was not specific for ALS; however, several findings from simple electrophysiological measurements may help predict prognosis in patients with motor neuron diseases and may be early diagnostic markers for ALS. Muscle Nerve 51: 333–337, 2015
Mean‐strain eight‐node hexahedron with stabilization by energy sampling
Authors: Krysl Petr
Published: June 2014

A method for stabilizing the mean‐strain hexahedron is described that differs from the currently known approaches. For simplicity, the developments are limited to linear elasticity but with an arbitrarily anisotropic elasticity matrix. The technique relies on a sampling of the stabilization energy using two quadrature rules, the mean‐strain quadrature and the full Gaussian integration rule. The use of two quadrature rules is shown to guarantee consistency and stability. The stabilization energy is assumed to be generated by a modified constitutive matrix based on the spectral decomposition. The spectral decomposition of the constitutive matrix identifies the stiff and flexible modes of deformation. The stiff modes of deformation are only sampled by the mean‐strain integration, which eliminates volumetric locking for isotropic materials as well as locking due to strongly anisotropic material properties. The accuracy and convergence characteristics of the present formulations compare favorably with the capabilities of mean‐strain and other high‐performance hexahedral elements as implemented in ABAQUS. Copyright © 2014 John Wiley & Sons, Ltd.
Improved fractional step method for simulating fluid‐structure interaction using the PFEM
Authors: Zhu Minjie , Scott Michael H.
Published: June 2014

Numerical difficulties are present in the particle finite element method even though it has been shown to be a powerful and effective approach to simulating fluid‐structure interaction. To overcome problems of mass loss on the free surface and the added‐mass effect, an improved fractional step method (FSM) that handles added‐mass terms in a mathematically exact way is developed. A further benefit is that no assumptions regarding the structural response are made in handling added‐mass terms, thus it is straightforward to incorporate material nonlinearity in fluid‐structure interaction (FSI) under this approach. Patch tests and comparisons with experimental data are presented in order to verify and validate the improved FSM for FSI applications. The computational cost of this approach is shown to be negligible compared with the other aspects of the FSM, particularly when the size of the structure and the fluid‐structure interface is small relative to the volume of fluid. Copyright © 2014 John Wiley & Sons, Ltd.
Human Response to Climate Change during the Umm an‐Nar/Wadi Suq Transition in the United Arab Emirates
Authors: Gregoricka L. A.
Published: June 2014

Stable oxygen isotope ratios in archaeological human dental enamel represent an under‐utilised tool in the examination of changing climatic patterns in the ancient world. In the Oman Peninsula at the end of the third millennium bc, rapid aridification was accompanied by a breakdown in interregional trade relations; however, the human response to these changes is poorly understood. At the Bronze Age necropolis at Shimal in the United Arab Emirates, dental enamel from individuals interred in both Umm an‐Nar (ca 2700–2000 bc) and Wadi Suq (ca 2000–1300 bc) tombs underwent oxygen, strontium and carbon isotope analyses to examine how local inhabitants of southeastern Arabia responded to both environmental and socioeconomic change. While individuals from Shimal exhibit a clear shift in mean δ18Oc(VPDB) values from the Umm an‐Nar (−3.5 ± 0.6‰, 1σ) to the Wadi Suq (−2.4 ± 0.9‰, 1σ), corresponding 87Sr/86Sr and δ13Cap signatures display homogeneity indicative of continuity in Bronze Age lifeways. Together, these data highlight the ability of local communities to successfully adapt to their changing environs (in lieu of societal collapse or a shift to a more mobile lifestyle) in an effort to maintain their way of life. Copyright © 2014 John Wiley & Sons, Ltd.
Temperature and environment dependent dynamic properties of a dendritic polyglycerol sulfate
Authors: Boreham Alexander , Brodwolf Robert , Pfaff Marcus , Kim Tai‐Yang , Schlieter Thomas , Mundhenk Lars , Gruber Achim D. , Gröger Dominic , Licha Kai , Haag Rainer , Alexiev Ulrike
Published: June 2014

Structural changes within dendritic polymer scaffolds may influence the polymer's behavior in biological relevant systems such as tissues and cells. A dendritic polyglycerol sulfate (dPGS) was recently found to act as an inhibitor of inflammatory processes. Here, we investigated the molecular dynamics and environmental sensitivity of dPGS using an indocarbocyanine (ICC) labeled variant (dPGS‐ICC). The environmental sensitivity was demonstrated by UV/Vis and fluorescence spectroscopic characterization of dPGS‐ICC in different solvents. In particular, fluorescence lifetime measurements revealed additional information on the local dye environment that manifest themselves in characteristic fluorescence lifetime signatures depending on the solvent. Furthermore, the interaction of dPGS‐ICC with a model cell system—giant unilamellar vesicles (GUVs)—was studied with fluorescence lifetime imaging microscopy. We observed that dPGS‐ICC is enriched in the membrane but does not penetrate into the lumen of the GUV. The characteristic lifetime signature of dPGS‐ICC within the lipid membrane (τmean = 1.6 ns) was clearly different from that obtained for dPGS‐ICC in aqueous solution (τmean = 0.42 ns) and can thus be employed to dissect differential interactions of dPGS in tissue. By using time‐resolved fluorescence depolarization, we further showed that the size of dPGS shrinks by nearly 50% above 30 °C. These results contribute to a further understanding of dPGS structure and dynamics and may help to provide tailor‐made polymer architectures for biomedical applications. Copyright © 2014 John Wiley & Sons, Ltd.
Separation of greenhouse gases from gas mixtures using nanoporous polymeric membranes
Authors: Mohammadi Mehrnoush , Shirazian Saeed , Asadollahzadeh Mehdi , Jamshidy Ladan , Hemmati Alireza
Published: June 2014

Removal of greenhouse gases from gas streams using porous membranes was carried out in this work. Theoretical studies were performed in terms of mathematical modeling and numerical simulation of CO2 capture in a flat‐sheet membrane contactor. Numerical simulation was performed using computational fluid dynamics (CFD) of mass and momentum transfer in the membrane module for laminar flow conditions. Physical absorption was considered in the simulations for absorption of CO2 in pure water. CO2 concentration distribution in the membrane module was determined through numerical solution of continuity equation coupled with the Navier‐Stokes equations. The modeling predictions indicated that the CO2 concentration difference is not appreciable in the membrane direction. Moreover, velocity distribution was determined in the liquid side of membrane contactor. CFD also represents a design and optimization tool for membrane gas separation processes. POLYM. ENG. SCI., 55:975–980, 2015. © 2014 Society of Plastics Engineers
Validation of a Patient‐Level Medication Regimen Complexity Index as a Possible Tool to Identify Patients for Medication Therapy Management Intervention
Authors: Hirsch Jan D. , Metz Kelli R. , Hosokawa Patrick W , Libby Anne M.
Published: June 2014

Background

The Medication Regimen Complexity Index (MRCI) is a 65‐item instrument that can be used to quantify medication regimen complexity at the patient level, capturing all prescribed and over‐the‐counter medications. Although the MRCI has been used in several studies, the narrow scope of the initial validation limits application at a population or clinical practice level.

Purpose

To conduct a MRCI validation pertinent to the desired clinical use to identify patients for medication therapy management interventions.

Methods

An expert panel of clinical pharmacists ranked medication regimen complexity for two samples of cases: a single‐disease cohort (diabetes mellitus) and a multiple‐disease cohort (diabetes mellitus, hypertension, human immunodeficiency virus infection, geriatric depression). Cases for expert panel review were selected from 400 ambulatory clinic patients, and each case description included data that were available via claims or electronic medical records (EMRs). Construct validity was assessed using patient‐level MRCI scores, medication count, and additional patient data. Concordance was evaluated using weighted κ agreement statistic, and correlations were determined using Spearman rank‐order correlation coefficient (ρ) or Kendall τ.

Results

Moderate to good concordance between patient‐level MRCI scores and expert medication regimen complexity ranking was observed (claims data, consensus ranking: single‐disease cohort 0.55, multiple disease cohort 0.63). In contrast, only fair to moderate concordance was observed for medication count (single‐disease cohort 0.33, multiple‐disease cohort 0.48). Adding more‐detailed administration directions from EMR data did not improve concordance. MRCI convergent validity was supported by strong correlations with medication count (all cohorts 0.90) and moderate correlations with morbidity measures (e.g., all cohorts; number of comorbidities 0.46, Chronic Disease Score 0.46). Nonsignificant correlation of MRCI scores with age and gender (all cohorts 0.08 and 0.06, respectively) supported MRCI divergent validity.

Limitations

This study used cross‐sectional, retrospective patient data for a small number of patients and clinical pharmacists from only two universities; therefore, results may have limited generalizability.

Conclusions

The patient‐level MRCI is a valid tool for assessing medication regimen complexity that can be applied by using data commonly found in claims and EMR databases and could be useful to identify patients who may benefit from medication therapy management.
Life at the border: Adaptation of proteins to anisotropic membrane environment
Authors: Pogozheva Irina D. , Mosberg Henry I. , Lomize Andrei L.
Published: June 2014

This review discusses main features of transmembrane (TM) proteins which distinguish them from water‐soluble proteins and allow their adaptation to the anisotropic membrane environment. We overview the structural limitations on membrane protein architecture, spatial arrangement of proteins in membranes and their intrinsic hydrophobic thickness, co‐translational and post‐translational folding and insertion into lipid bilayers, topogenesis, high propensity to form oligomers, and large‐scale conformational transitions during membrane insertion and transport function. Special attention is paid to the polarity of TM protein surfaces described by profiles of dipolarity/polarizability and hydrogen‐bonding capacity parameters that match polarity of the lipid environment. Analysis of distributions of Trp resides on surfaces of TM proteins from different biological membranes indicates that interfacial membrane regions with preferential accumulation of Trp indole rings correspond to the outer part of the lipid acyl chain region—between double bonds and carbonyl groups of lipids. These “midpolar” regions are not always symmetric in proteins from natural membranes. We also examined the hydrophobic effect that drives insertion of proteins into lipid bilayer and different free energy contributions to TM protein stability, including attractive van der Waals forces and hydrogen bonds, side‐chain conformational entropy, the hydrophobic mismatch, membrane deformations, and specific protein–lipid binding.
Monitoring Process Variability for Stationary Process Data
Authors: Zhang Nien Fan , Pintar Adam L.
Published: June 2014

Processes that arise naturally, for example, from manufacturing or the environment, often exhibit complicated autocorrelation structures. When monitoring such a process for changes in variance, accounting for that structure is critical. While charts for monitoring the variance of processes of independent observations and some specific autocorrelated processes have been proposed in the past, the chart presented in this article can handle a general stationary process. The performance of the proposed chart was examined through simulations for the first‐order autoregressive and first‐order autoregressive‐moving average processes and demonstrated with examples. Copyright © 2014 John Wiley & Sons, Ltd.
Exploration of polyamide structure–property relationships by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Barrère Caroline , Rejaibi Majed , Curat Aurélien , Hubert‐Roux Marie , Lavanant Hélène , Afonso Carlos , Kebir Nasreddine , Desilles Nicolas , Lecamp Laurence , Burel Fabrice , Loutelier‐Bourhis Corinne
Published: June 2014

RATIONALE

Polyamides (PA) are among the most used classes of polymers because of their attractive properties. Depending on the nature and proportion of the co‐monomers used for their synthesis, they can exhibit a very large range of melting temperatures (Tm). This study aims at the correlation of data from mass spectrometry (MS) with differential scanning calorimetry (DSC) and X‐ray diffraction analyses to relate molecular structure to physical properties such as melting temperature, enthalpy change and crystallinity rate.

METHODS

Six different PA copolymers with molecular weights around 3500 g mol–1 were synthesized with varying proportions of different co‐monomers (amino‐acid AB/di‐amine AA/di‐acid BB). Their melting temperature, enthalpy change and crystallinity rate were measured by DSC and X‐ray diffraction. Their structural characterization was carried out by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS). Because of the poor solubility of PA, a solvent‐free sample preparation strategy was used with 2,5‐dihydroxybenzoic acid (2,5‐DHB) as the matrix and sodium iodide as the cationizing agent.

RESULTS

The different proportions of the repeating unit types led to the formation of PA with melting temperatures ranging from 115°C to 185°C. The structural characterization of these samples by MALDI‐TOF‐MS revealed a collection of different ion distributions with different sequences of repeating units (AA, BB; AB/AA, BB and AB) in different proportions according to the mixture of monomers used in the synthesis. The relative intensities of these ion distributions were related to sample complexity and structure. They were correlated to DSC and X‐ray results, to explain the observed physical properties.

CONCLUSIONS

The structural information obtained by MALDI‐TOF‐MS provided a better understanding of the variation of the PA melting temperature and established a structure‐properties relationship. This work will allow future PA designs to be monitored. Copyright © 2014 John Wiley & Sons, Ltd.
Transmission geometry laser ablation into a non‐contact liquid vortex capture probe for mass spectrometry imaging
Authors: Ovchinnikova Olga S. , Bhandari Deepak , Lorenz Matthias , Van Berkel Gary J.
Published: June 2014

RATIONALE

Capture of material from a laser ablation plume into a continuous flow stream of solvent provides the means for uninterrupted sampling, transport and ionization of collected material for coupling with mass spectral analysis. Reported here is the use of vertically aligned transmission geometry laser ablation in combination with a new non‐contact liquid vortex capture probe coupled with electrospray ionization for spot sampling and chemical imaging with mass spectrometry.

METHODS

A vertically aligned continuous flow liquid vortex capture probe was positioned directly underneath a sample surface in a transmission geometry laser ablation (355 nm, 10 Hz, 7 ns pulse width) set up to capture into solution the ablated material. The outlet of the vortex probe was coupled to the Turbo V™ ion source of an AB SCIEX TripleTOF 5600+ mass spectrometer. System operation and performance metrics were tested using inked patterns and thin tissue sections. Glass slides and slides designed especially for laser capture microdissection, viz., DIRECTOR® slides and PEN 1.0 (polyethylene naphthalate) membrane slides, were used as sample substrates.

RESULTS

The estimated capture efficiency of laser‐ablated material was 24%, which was enabled by the use of a probe with large liquid surface area (~2.8 mm2) and with gravity to help direct ablated material vertically down towards the probe. The swirling vortex action of the liquid surface potentially enhanced capture and dissolution not only of particulates, but also of gaseous products of the laser ablation. The use of DIRECTOR® slides and PEN 1.0 (polyethylene naphthalate) membrane slides as sample substrates enabled effective ablation of a wide range of sample types (basic blue 7, polypropylene glycol, insulin and cyctochrome c) without photodamage using a UV laser. Imaging resolution of about 6 µm was demonstrated for stamped ink on DIRECTOR® slides based on the ability to distinguish features present both in the optical and in the chemical image. This imaging resolution was 20 times better than the previous best reported results with laser ablation/liquid sample capture mass spectrometry imaging. Using thin sections of brain tissue the chemical image of a selected lipid was obtained with an estimated imaging resolution of about 50 µm.

CONCLUSIONS

A vertically aligned, transmission geometry laser ablation liquid vortex capture probe, electrospray ionization mass spectrometry system provides an effective means for spatially resolved spot sampling and imaging with mass spectrometry. Published in 2014. This article is a U.S. Government work and is in the public domain in the USA.
Product ion distributions for the reactions of NO+ with some physiologically significant volatile organosulfur and organoselenium compounds obtained using a selective reagent ionization time‐of‐flight mass spectrometer
Authors: Mochalski Paweł , Unterkofler Karl , Španěl Patrik , Smith David , Amann Anton
Published: June 2014

RATIONALE

The reactions of NO+ with volatile organic compounds (VOCs) in Selective Reagent Ionization Time‐of‐Flight Mass Spectrometry (SRI‐TOF‐MS) reactors are relatively poorly known, inhibiting their use for trace gas analysis. The rationale for this product ion distribution study was to identify the major product ions of the reactions of NO+ ions with 13 organosulfur compounds and 2 organoselenium compounds in an SRI‐TOF‐MS instrument and thus to prepare the way for their analysis in exhaled breath, in skin emanations and in the headspace of urine, blood and cell and bacterial cultures.

METHODS

Product ion distributions have been investigated by a SRI‐TOF‐MS instrument at an E/N in the drift tube reactor of 130 Td for both dry air and humid air (4.9% absolute humidity) used as the matrix gas. The investigated species were five monosulfides (dimethyl sulfide, ethyl methyl sulfide, methyl propyl sulfide, allyl methyl sulfide and methyl 5‐methyl‐2‐furyl sulfide), dimethyl disulfide, dimethyl trisulfide, thiophene, 2‐methylthiophene, 3‐methylthiophene, methanethiol, allyl isothiocyanate, dimethyl sulfoxide, and two selenium compounds – dimethyl selenide and dimethyl diselenide.

RESULTS

Charge transfer was seen to be the dominant reaction mechanism in all reactions under study forming the M+ cations. For methanethiol and allyl isothiocyanate significant fractions were also observed of the stable adduct ions NO+M, formed by ion‐molecule association, and [M–H]+ ions, formed by hydride ion transfer. Several other minor product channels are seen for most reactions indicating that the nascent excited intermediate (NOM)+* adduct ions partially fragment along other channels, most commonly by the elimination of neutral CH3, CH4 and/or C2H4 species that are probably bound to an NO molecule. Humidity had little effect on the product ion distributions.

CONCLUSIONS

The findings of this study are of particular importance for data interpretation in studies of volatile organosulfur and volatile organoselenium compounds employing SRI‐TOF‐MS in the NO+ mode. © 2014 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.
Gas chromatography/isotope ratio mass spectrometry: Analysis of methanol, ethanol and acetic acid by direct injection of aqueous alcoholic and acetic acid samples
Authors: Ai Guomin , Sun Tong , Dong Xiuzhu
Published: June 2014

RATIONALE

Methanol, ethanol, and acetic acid are not easily extracted from aqueous samples and are susceptible to isotope fractionation in gas chromatography/isotope ratio mass spectrometry (GC/IRMS) analysis. Developing a direct dilution GC/IRMS method for aqueous samples, by adjusting the sample concentrations in common solvents to be similar to each other and using a fixed GC split ratio, is very convenient and important because any linearity effects caused by amount‐dependent isotope fractionation can be avoided.

METHODS

The suitability of acetonitrile and acetone solvents for the GC/IRMS analysis of pure methanol, ethanol and acetic acid, and commercial liquor and vinegar samples was evaluated using n‐hexane and water as control solvents. All the solvents including water were separated from the analyte on a HP‐INNOWAX column and were diverted away from the combustion interface. The influence of liquor matrix on the ethanol GC/IRMS analyses was evaluated by adding pure ethanol to liquor samples.

RESULTS

Acetonitrile and acetone gave similar δ13C values for pure ethanol and pure acetic acid to those obtained in water and n‐hexane, and also gave similar δ13C values of ethanol in liquor and acetic acid in white vinegar to that obtained in water. For methanol analysis, acetonitrile and refined acetone gave similar δ13C values to that obtained in water, but n‐hexane was not a suitable solvent. In addition, isotopic fractionation caused by solvent and solute interactions was observed.

CONCLUSIONS

We recommend using acetonitrile for the GC/IRMS analysis of aqueous alcoholic samples, and acetone for the analysis of aqueous acetic acid samples. This direct dilution method can provide high accurate and precise GC/IRMS analysis of the relative changes in δ13C values of methanol, ethanol, and acetic acid. Copyright © 2014 John Wiley & Sons, Ltd.
Temporal and spatial analysis of enteric nervous system regeneration in the sea cucumber Holothuria glaberrima
Authors: Tossas Karen , Qi‐Huang Sunny , Cuyar Eugenia , García‐Arrarás Jose E.
Published: June 2014

There is limited information on the regeneration of the enteric nervous system (ENS) following major reconstruction of the digestive tract. We have studied ENS regeneration in the sea cucumber Holothuria glaberrima which undergoes an organogenic process forming a new digestive tract at the tip of the mesentery. Our results show that (1) a degeneration of nerve fibers occurs early in the regeneration process, prior to eventual regeneration; (2) nerve fibers that innervate the regenerating intestine are of extrinsic and intrinsic origin; (3) innervation by extrinsic fibers occurs in a gradient that begins in the proximal area of the regenerate; (4) late events include the appearance of nerve fibers that project from the serosa into the connective tissue and of nerve bundles in the mesothelial layer; (5) neurons and neuroendocrine cells appear early following the formation of the epithelial layers. Our results provide not only a comparative biological approach to study ENS regeneration but also an alternative point of view for the study of enteric neuropathologies and for the innervation of organs made in vitro.
Estimating cancer incidence using a Bayesian back‐calculation approach
Authors: Ventura Leonardo , Mezzetti Maura
Published: June 2014

We propose a Bayesian hierarchical model for the calculation of incidence counts from mortality data by a convolution equation that expresses mortality through its relationship with incidence and the survival probability density. The basic idea is to use mortality data together with an estimate of the survival distribution from cancer incidence to cancer mortality to reconstruct the numbers of individuals who constitute previously incident cases that give rise to the observed pattern of cancer mortality. This model is novel because it takes into account the uncertainty from the survival distribution; thus, a Bayesian‐mixture cure model for survival is introduced. Furthermore, projections are obtained starting from a Bayesian age‐period‐cohort model. The main advantage of the proposed approach is its consideration of the three components of the model: the convolution equation, the survival mixture cure model and the age‐period‐cohort projection within a directed acyclic graph model. Furthermore, the estimation are obtained through the Gibbs sampler. We applied the model to cases of women with stomach cancer using six age classes [15–45], [45–55], [55–65], [65–75], [75–85] and [85–95] and validated it by using data from the Tuscany Cancer Registry. The model proposed and the program implemented are convenient because they allow different cancer disease to be analysed because the survival time is modelled by flexible distributions that are able to describe different trends. Copyright © 2014 John Wiley & Sons, Ltd.
Automatic optimization of piled raft design based on branch and bound method
Authors: Sales Maurício M. , Lima Bruno S. , Almeida Sylvia Regina M. , Farias Márcio M.
Published: June 2014

Piled rafts are foundation systems that combine a shallow raft with the minimum number of piles beneath the raft, in order to achieve the necessary bearing capacity and the acceptable settlement restrictions. Its use is increasing in many countries, especially in skyscrapers in Europe and Asia, for which the foundation design can result in hundreds of piles due to the high load magnitude. However, controlling the most influencing variables on the foundation behaviour, while achieving an acceptable cost, is a challenge for designers. This paper presents an optimization procedure to determine the best raft thickness, number of piles and their location. The branch and bound optimization method was combined with a specific computational programme for piled raft analysis (GARP) providing an automatic technique to obtain the lower cost design. A building in Brazil and theoretical examples of a piled raft with different load sets are presented and analysed using this numerical approach. The results show that the presented automatic procedure provides interesting solutions, economically enhancing the design of piled raft foundation systems. The optimization process provides arrangements using lower number of piles while satisfying the constraints in both analysed cases. Copyright © 2014 John Wiley & Sons, Ltd.
Building Greater Sustainability in Supply Chains
Authors: Kashmanian Richard M. , Moore Justin R.
Published: June 2014

Challenges companies face and tools they use to identify and reduce their environmental footprints across their supply chains
EU governance for research and training in nuclear fission: from knowledge creation to competence building
Authors: Van Goethem Georges
Published: June 2014

In a rapidly changing world, research and training (R&T) in nuclear fission and radiation protection is faced with a number of scientific‐technological and sociopolitical challenges that require a new type of governance. In the European Union (EU), those challenges are, for example, technological developments aimed at optimizing the role of nuclear fission in the energy mix and the related processes for knowledge creation and competence building.

The main stakeholders of Euratom R&T programmes have developed a common approach regarding the needs, vision, and implementation instruments. Focussing on education and training (E&T), the common approach of the nuclear fission stakeholders can be summarized as follows:

Analysis of the needs of society and industry: e.g., what kind of knowledge, skills, and competences should be taught to continuously improve safety (technology and culture)?

Convergence toward a common vision: e.g., toward a new governance for Euratom aiming to develop scientific and organizational excellence in all parts of the EU.

Development of common instruments: e.g., synergy of national and Euratom E&T programmes for lifelong learning and cross‐border mobility (freedom of establishment).

The above approach is aligned with the Europe 2020 strategy for smart, sustainable and inclusive growth. It is shown how a new European governance structure is developing, based on improved participation, openness, accountability, effectiveness, and coherence. As a result, a new way of ‘developing/teaching science’ is proposed, closer to the end users, with the ultimate aim to develop robust, equitable, and socially acceptable energy systems. WIREs Energy Environ 2014, 3:604–617. doi: 10.1002/wene.126

This article is categorized under:

Nuclear Power > Science and Materials
Clinical Strategy for the Reconstruction of Middle Hepatic Vein Tributaries in Right Liver Living Donor Liver Transplantation
Authors: Chan Kun‐Ming , Cheng Chih‐Hsien , Wu Tsung‐Han , Wu Ting‐Jung , Chou Hong‐Shiue , Lee Ching‐Sung , Lee Wei‐Chen
Published: June 2014

Background

Venous drainage of the right paramedian sector (segments V and VIII), which is mainly via the middle hepatic vein (MHV), remains the major concern when using a right liver graft in living donor liver transplantation (LDLT). We herein describe our approach to decision making in the reconstruction of MHV tributaries in LDLT using a right liver graft without the MHV trunk.

Methods

A total of 77 consecutive right liver LDLTs were performed between January 2011 and December 2012. The MHV trunk was not taken with the graft, and all MHV tributaries were ligated during donor hepatectomy. The right liver graft was subsequently assessed on the back table for congestion in the right paramedian sector as an indicator for the need to reconstruct MHV tributaries.

Results

Based on the algorithm, reconstruction of MHV tributaries was performed in 18 patients (23.4 %). Although a mild degree of congestion in the right paramedian sector was noted in a few liver grafts without venous reconstruction, this congestion was well tolerated by recipients and was not visible afterward. The recipients’ outcomes were similar in groups with and without venous reconstruction, and the 1‐year survival rates were 83.3 and 86.2 %, respectively.

Conclusion

A right liver graft without the MHV trunk can be successfully performed in LDLT with a satisfactory outcome. However, these experiences show that this approach might be safely applied as a strategy for determining the necessity of reconstruction of MHV tributaries in a right liver graft without the MHV trunk in LDLT.
A Protective Factors Model for Alcohol Abuse and Suicide Prevention Among Alaska Native Youth
Authors: Allen James , Mohatt Gerald V. , Fok Carlotta Ching Ting , Henry David , Burkett Rebekah
Published: June 2014

This study provides an empirical test of a culturally grounded theoretical model for prevention of alcohol abuse and suicide risk with Alaska Native youth, using a promising set of culturally appropriate measures for the study of the process of change and outcome. This model is derived from qualitative work that generated an heuristic model of protective factors from alcohol (Allen et al. in J Prev Interv Commun 32:41–59, 2006; Mohatt et al. in Am J Commun Psychol 33:263–273, 2004a; Harm Reduct 1, 2004b). Participants included 413 rural Alaska Native youth ages 12–18 who assisted in testing a predictive model of Reasons for Life and Reflective Processes about alcohol abuse consequences as co‐occurring outcomes. Specific individual, family, peer, and community level protective factor variables predicted these outcomes. Results suggest prominent roles for these predictor variables as intermediate prevention strategy target variables in a theoretical model for a multilevel intervention. The model guides understanding of underlying change processes in an intervention to increase the ultimate outcome variables of Reasons for Life and Reflective Processes regarding the consequences of alcohol abuse.
Geochemical and Mineralogical Studies of Chlorine-rich Amphibole and Biotite from the 2.5 Ga Mid-crustal Basement Beneath the 1993 Killari Earthquake Region, Maharashtra: Evidence for Mantle Metasomatism Beneath the Deccan Trap
Authors: Pandey O.P. , Tripathi Priyanka , Parthasarathy G. , Rajagopalan V. , Sreedhar B.
Published: June 2014

Fluid driven metasomatism and mass transfer from the earth’s mantle have played an important role in the evolution of the lower continental crust in many geodynamically active areas. The epicentral region of the disastrous 1993 Killari earthquake (M 6.2), concealed below a thick suite of Deccan volcanics in central India, appear to be one such region. In connection with the study of seismotectonics of the earthquake prone Deccan volcanic region, we have carried out systematic and detailed geochemical and mineralogical investigation on core samples from the basement, obtained from the 617m deep KLR-1 borehole, drilled in the epicentral region of Killari. Our investigations indicate that the basement, concealed below 338m thick Deccan volcanics, is made up of CO2, Cl, FeO and CaO-rich, high density (2.82 g/cm3) - high velocity (avg. Vp: 6.2 km/s) moderately retrogressed upper amphibolite to granulite facies mid crustal rocks, which were subjected to pervasive Ca-metasomatism due to infiltration of mantle fluids. Granitic-gneissic layer, typical of the upper crust, seems to be totally absent from this earthquake region. Chondrite normalized trace and rare earth elemental patterns display negative Eu anomalies together with LILE enrichment. Similarly, spider diagrams for incompatible elements show depletion in Zr, Hf, Y, Ta and Nb relative to the primitive mantle, indicating possible alterations of such relatively immobile elements at relatively high temperatures. Selective enrichment is also observed in transitional elements like Cu and Zn, indicating the possible role of chlorine in metal transport. The present study suggests that regional metasomatism beneath the Deccan Traps, which apparently alters the basic fabric of the rock during recrystallisation and makes it weak, may have a link with the nucleation of large earthquakes.
Soil Loss Estimation by Field Measurements in the Badlands along Pravara River (Western India)
Authors: Joshi Veena U.
Published: June 2014

Nearly 4 million hectares of land in India is affected by rill and gully erosion. It is a severe form of soil erosion rendering vast tracts of lands into wastelands giving rise to the formation of badlands. Rate of land degradation through gullying is triggered recently due to the ill-advised landuse practices all over the country. The study area represents one such badland locality along the banks of Pravara river and two of its tributaries in the Deccan trap region, Maharashtra. The area is extensively reclaimed in the last two decades for agricultural practices. The rates in the cross profile changes as well as land lowering were measured with the help of a self fabricated micro-profilometer and erosion pin method. Five first order gullies were monitored using the micro-profilometer. Results of the micro-profilometer technique reveal considerable changes in the cross-sectional areas of individual gullies in this area, which shows the dynamic soil removal mechanism operating in this region. In addition to this, two well developed gully catchments were surveyed using a theodolite and erosion pins were installed in these basins in May 2007. After one year, the exposed pinheads were measured and net gain and net loss in the volume of the sediments were calculated for both the basins. The same practice continued in May 2009. After two years of monitoring the sediment yields were calculated. Average of these two years indicates an annual sediment yield of 1.79 kg/m2 for sample basin 1 and 0.76 kg/m2 for sample basin 2. The calculated yield was compared with the threshold values of soil tolerance limits and it was found that the area has crossed the threshold limit of soil tolerance.