bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility analysis of early temporal kinetics as a surrogate marker for breast tumor type, grade, and aggressiveness
Authors: Heacock Laura , Lewin Alana A. , Gao Yiming , Babb James S. , Heller Samantha L. , Melsaether Amy N. , Bagadiya Neeti , Kim Sungheon G. , Moy Linda
Published: November 2017

Background

Screening breast MRI has been shown to preferentially detect high‐grade ductal carcinoma in situ (DCIS) and invasive carcinoma, likely due to increased angiogenesis resulting in early initial uptake of contrast. As interest grows in abbreviated screening breast MRI (AB‐MRI), markers of early contrast washin that can predict tumor grade and potential aggressiveness are of clinical interest.

Purpose

To evaluate the feasibility of using the initial enhancement ratio (IER) as a surrogate marker for tumor grade, hormone receptor status, and prognostic markers, as an initial step to being incorporated into AB‐MRI.

Study Type

Retrospective.

Subjects

In all, 162 women (mean 55.0 years, range 32.8–87.7 years) with 187 malignancies imaged January 2012–November 2015.

Field Strength/Sequence

Images were acquired at 3.0T with a T1‐weighted gradient echo fat‐suppressed‐volume interpolated breath‐hold sequence.

Assessment

Subjects underwent dynamic contrast‐enhanced breast MRI with a 7‐channel breast coil. IER (% signal increase over baseline at the first postcontrast acquisition) was assessed and correlated with background parenchymal enhancement, washout curves, stage, and final pathology.

Statistical Tests

Chi‐square test, Spearman rank correlation, Mann–Whitney U‐tests, Bland–Altman analysis, and receiver operating characteristic curve analysis.

Results

IER was higher for invasive cancer than for DCIS (R1/R2, P < 0.001). IER increased with tumor grade (R1: r = 0.56, P < 0.001, R2: r = 0.50, P < 0.001), as ki‐67 increased (R1: r = 0.35, P < 0.001; R2 r = 0.35, P < 0.001), and for node‐positive disease (R1/R2, P = 0.001). IER was higher for human epidermal growth factor receptor two‐positive and triple negative cancers than for estrogen receptor‐positive / progesterone receptor‐positive tumors (R1 P < 0.001–0.002; R2 P = 0.0.001–0.011). IER had higher sensitivity (80.6% vs. 75.5%) and specificity (55.8% vs. 48.1%) than washout curves for positive nodes, higher specificity (48.1% vs. 36.5%) and positive predictive value (70.2% vs. 66.7%) for high ki‐67, and excellent interobserver agreement (intraclass correlation coefficient = 0.82).

Data Conclusion

IER, a measurement of early contrast washin, is associated with higher‐grade malignancies and tumor aggressiveness and might be potentially incorporated into an AB‐MRI protocol.

Level of Evidence: 3

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;47:1692–1700.
The drivers of variability in UK extreme rainfall
Authors: Brown Simon J.
Published: November 2017

The effect of large‐scale modes of climate variability on extreme UK daily rainfall, together with potential trends is investigated with non‐stationary extreme value analysis. Extreme rainfall is identified from 25 km gridded observations spanning 1958–2012 and to which generalized extreme value (GEV) distributions are fitted. The GEV location and scale parameters are assessed for their dependence on indices of the El Niño‐Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation (NAO) and Atlantic Multi‐decadal Oscillation (AMO), together with any evidence of trend. The influence of indices and trend are assessed individually and in combination, for individual months and 3‐month rolling seasons. To improve signal‐to‐noise ratio all data below 200 m elevation is pooled. The NAO is found to have the greatest impact with positive NAO reducing the likelihood of extreme rainfall from spring to autumn, but increasing it in winter. London's 50 year return level for JJA (DJF) ranges from 34(26) mm day−1at maximum NAO to 51(24) mm day−1for minimum NAO over the observed period. A weak ENSO influence is only found for early winter (NDJ) and no influence detected for PDO or AMO. Trends towards more extreme rainfall were found for OND and DJF; however, the inclusion of NAO resulted in reduced magnitude and significance for DJF trends. Robust trends were found for the winter half year irrespective of NAO influence, with London's 50‐year return level increasing by 6%. Extreme rainfall changes associated with NAO are consistent with NAO driven changes in extra‐tropical cyclones. Positive NAO non‐winter months have fewer less intense storms crossing the UK in contrast to winter where they are more frequent and intense. The speed of storms is also higher during positive NAO winters which can mitigate increases in the rarest events.
Peritraumatic Assessment of Autobiographical Memory After Exposure to a Traumatic Event
Authors: Billoux Sophie , Voltzenlogel Virginie , Telmon Norbert , Birmes Philippe , Arbus Christophe
Published: November 2017

Posttraumatic stress disorder (PTSD) is commonly acknowledged to be associated with reduced specificity of autobiographical memory (AM). However, very few studies have assessed AM in the peritraumatic phase. The aim of the present study was to examine whether the AM impairment reported in PTSD is present a few days after a traumatic event. We assessed AM in 41 participants who had recently been exposed to trauma, and 34 controls who had never experienced a traumatic situation. The trauma‐exposed participants also completed the Impact of Event Scale‐R (IES‐R), the Inventory of Peritraumatic Distress, and the Peritraumatic Dissociative Experiences Questionnaire. Results showed that autobiographical memories cued by negative words were significantly less specific in the group of trauma‐exposed participants than in the control group (p = .008; d = 0.40). Thus, mild AM impairment was already present three days after trauma exposure, long before acute PTSD set in.
Crops and livestock under the sun: Obstacles to rural livelihood adaptations to hotter 21st century temperatures in eastern Senegal
Authors: Brottem Leif , Brooks Bonnie
Published: November 2017

This article evaluates the proposition that farmers in dryland West Africa will be compelled by midcentury to shift household resources from crop to livestock production due to changing climate conditions. The article investigates the prospects for such a livelihood transition in the semiarid part of eastern Senegal, where downscaled statistical models indicate temperature increases of at least 2°, that will have substantially negative impacts on crop yields. Based on survey of 448 households and focus groups conducted across an eco‐climatological transect, the article presents evidence that this livelihood transition is already underway in many households but is increasingly out of reach for others. It uses statistical and qualitative analysis to argue that the most vulnerable households—crop‐dependent smallholders in the geographic area where the livelihood shift is most needed—are the least prepared for it. The article shows that land degradation is both an additional cause of the transition and an obstacle to it. Soil exhaustion, made worse by the lack of opportunities to procure chemical fertilizer, is compelling many to seek to increase their livestock holdings. This strategy is constrained by rangeland degradation, which, made worse by expanding agriculture, reduces the viability of the transition for all but the wealthiest households. Households rely on migration to compensate for shortfalls in production, but this option is becoming closed off to those households who do not already have a member abroad. This is shown to raise the vulnerability of households who rely on a degraded resource base for their livelihoods.
Clinical feasibility study of protrach dualcare a new speaking valve with heat and moisture exchanger for tracheotomized patients
Authors: de Kleijn B.J. , van As‐Brooks C.J. , Wedman J. , van der Laan B.F.A.M.
Published: November 2017

Objective

The aim of this study was to evaluate the clinical feasibility of the ProTrach DualCare (Atos Medical, Hörby, Sweden), a device combining a hands‐free speaking valve and a Heat and Moisture Exchanger (HME) for tracheotomized patients.

Study Design

A non‐randomized, prospective single center feasibility study.

Methods

Sixteen adult tracheotomized patients were included. Participants were asked to test the DualCare for two weeks while continuing their normal activities. After these two weeks, participants could choose whether or not to take part in the long‐term evaluation. The EuroQOL‐5D, Borg scale and questionnaires on speaking, pulmonary function and patient preference were used. During the long‐term evaluation, a minor redesign was implemented and all participants were asked to test the new device again for one week, with a potential long‐term evaluation. Eleven decided to participate.

Results

The device was well‐tolerated. Speaking noise was reduced (p = 0.020) and speech was considered to sound more natural compared to previously used devices according to the users (p = 0.020). Overall 11 participants preferred the DualCare to their standard device. No serious adverse events were reported.

Conclusion

Overall, 11 of 16 participants preferred the DualCare to their standard speaking valve or HME. Users of the DualCare were able to use hands free speech with the benefits of an HME and the device was considered clinically feasible and has the potential to improve quality of life of tracheotomized patients.

Level of Evidence

2b
Evaluation of linear autoregressive models for estimation of energy spectra in gappy turbulent velocity data
Authors: Lai Chris C. K. , Socolofsky Scott A.
Published: November 2017

This paper deals with the problem of data interpolation in velocity time series measured by acoustic Doppler velocimeters and acoustic Doppler current profilers; the gap‐filled data are often used to determine turbulent kinetic energy (TKE) dissipation using Kolmogorov's inertial subrange scaling. For the latter to estimate dissipation accurately, it is important that the interpolation scheme preserves the attributes, both spectral slope and component magnitudes, of the true energy spectrum. We show that this goal can be achieved using the simple zeroth‐order sample and hold interpolation in situations where isolated data gaps, having durations shorter than the integral time scale of flow, occur. Its success is explained using the framework of stochastic autoregressive (AR) processes, which we also compare to the Langevin equation for the Lagrangian velocity of a turbulent flow field. We also demonstrate that linear interpolation is not appropriate because it can be interpreted as a nonstationary second order AR process, leading to erroneous conclusions for spectral slope and magnitude. When data dropouts occur in clusters, i.e., of durations longer than the integral time scale, we propose to use the first order AR process, of which sample and hold is its limiting case, for interpolation. The effectiveness of our proposal is tested and demonstrated with synthetic time series having a range of spectral slopes, from −7/6 to −8/3, and with experimental data measured in a turbulent channel flow. A comparison is also made with the more sophisticated proper orthogonal decomposition‐based interpolation. The paper ends with a step‐by‐step procedure on using the proposed method in applications.
Differential effects of solid‐phase extraction resins on the measurement of dissolved lignin‐phenols and organic matter composition in natural waters
Authors: Arellano Ana R. , Bianchi Thomas S. , Hutchings Jack A. , Shields Michael R. , Cui Xingqian
Published: November 2017

Compositional changes in dissolved organic matter (DOM) matrix via solid phase extraction (SPE) remain under‐constrained due to disproportional extraction of specific groups of compounds. This study elucidates changes in the composition of DOM via SPE by presenting an intercomparison of recovery efficiencies of dissolved lignin phenol standards using three SPE cartridges (C‐18, PPL and HLB) and an intercomparison of free‐lignin phenols and lignin‐oxidized products (LOPs) (via SPE) for two end‐members (river and coastal) in the Suwannee River, Cedar Key, Florida. A comparison was also made between DOC and dissolved lignin recovery rates, fluorescence intensity, EEMs indices, spectral slope (SR) and specific UV absorbance at 254 nm (SUVA254) for the river end‐members. Isolates harbored lower fluorescence intensities, lower EEMs index values, lower aromatic indices and higher spectral slopes indicating changes in both concentration and composition after SPE. Our results highlight that fractionation is occurring during SPE for lignin‐phenol standards, LOPs, and DOM. Riverine end‐member DOC extraction efficiencies and dissolved lignin (Σ8) recoveries were 46–60% and 41–48%, respectively, while coastal end‐member DOC efficiencies were lower and ranged from to 41% to 47%. In terms of DOC recovery, PPL was the best for river (60%) and coastal (47%), while in terms of LOP recovery, the three cartridges gave comparable results for dissolved lignin and one cartridge type is not necessarily better than the others for coastal samples.
Spectrophotometric pH measurements in the presence of dissolved organic matter and hydrogen sulfide
Authors: Müller Jens Daniel , Schneider Bernd , Aßmann Steffen , Rehder Gregor
Published: November 2017

Spectrophotometric pH measurements were first introduced for oceanic environments and they facilitated the determination of the marine CO2 system, including the direct observation of Ocean Acidification. Extended characterizations of the indicator dye m‐Cresol purple over the past two decades enabled the application of this method to natural waters ranging from brines to freshwaters. However, the required determination of the dye's dissociation constants and absorbance properties were exclusively performed in buffer solutions prepared with artificial seawater. Potential perturbations by substances that occur in natural waters, but are not included in the buffer solutions, have never been tested. Therefore, we studied the impact of elevated amounts of dissolved organic matter (DOM) and hydrogen sulfide (H2S) on spectrophotometric pH measurements. We did not observe an impact on spectrophotometric pH measurements by H2S concentrations up to 400 μmol kg−1, which reflect high levels such as those reported from the Black Sea. Likewise, natural DOM did not interfere with the spectrophotometric measurements at concentrations typical for oceanic environments and large estuarine systems. However, strongly colored river waters can cause spectral disturbances resulting in calculated pH values that are up to tenths of pH units too low. To circumvent such disturbances, we recommend using intense light sources, a shorter cuvette length or spectrophotometrically calibrated glass electrodes when performing spectrophotometric measurements under critical conditions.
A novel ammonium‐free seawater preparation method for determination of trace quantities of ammonium in seawater
Authors: Zhu Yong , Yuan Dongxing , Chen Jianfang , Lin Kunning , Huang Yongming
Published: November 2017

A novel method for preparation of ammonium‐free seawater, which is used as a carrier solution and matrix for standard solutions, was designed. These standard solutions are used for calibration curve in flow analysis to detect trace quantities of ammonium in seawater. The system, which consisted of only a peristaltic pump and a hydrophilic‐lipophilic balance (HLB) cartridge, was simple, convenient, and easy to operate. The original seawater used in the method could be collected from the coastal regions. And appropriate quantities of o‐phthaldialdehyde (OPA) and sulfite solution were added to the original seawater (The molar proportions of ammonium : OPA : sulfite were 1 : 200 : 80). After allowing it to set for more than 16 h, the seawater was pumped through the HLB cartridge. The reaction product of ammonium (present in the matrix), OPA and sulfite was retained by the HLB column and the solution coming out of the cartridge was ammonium‐free seawater. The ammonium in the original seawater was efficiently removed and also its concentration in the ammonium‐free seawater prepared by this method was much lower than that of the seawater collected from the surface of the South China Sea. The difference in the salinity of the seawater before and after the process was negligible, and also the pH was slightly increased. Moreover, ammonium‐free seawater could be prepared whenever required, and contamination due to transportation and storage could be prevented.
Electromagnetic induction corrosion control technology (EICCT)
Authors: Macdonald Digby D. , Lewis Michael , McLafferty Jason , Maya‐Visuet Enrique , Peek Randy
Published: November 2017

Over the past several years, a new corrosion control technology has been developed for protecting damaged, painted galvanized, and galvannealed surfaces in contact with ambient aqueous environments. This technology, which we call electromagnetically induced corrosion control technology (EICCT), is an electronic technology that is based upon coupling surface currents into the metal structure to be protected. Electromagnetic induction experiments have demonstrated that the induced current is spread across the surfaces of complex shapes, such as an automobile body, as required by Maxwell's equations, so that induction at a single point is effective in protecting a whole, complex‐shaped surface, that the power consumption is very low, and possibly that the induced signal may be tailored to optimize the efficacy. The observed efficacy is attributed to inhibition of zinc passivation as directly indicated by the coupling current. Efficacy is also indicated by inhibition of rusting at scribes in painted panels. It is important to emphasize that the technique is not a classical, impressed current cathodic protection (ICCP) system.
Effects of non‐isothermal aging process on mechanical properties and corrosion resistance of Al–Mg–Si aluminum alloy
Authors: Zhu Yuan , Ji Qing Qing , Jin Man
Published: November 2017

Effects of non‐isothermal aging treatment on mechanical properties and corrosion resistance of Al–Mg–Si aluminum alloy were investigated by hardness test, tensile test, intergranular corrosion test, and TEM observation. The results suggested that the NIA process (heating from 30 °C to 190 °C at 20 °C/h) is capable of enduing higher mechanical performances and comparable corrosion resistance to Al–Mg–Si alloys, as compared with that of the T73 condition. The different evolution of precipitates in intra‐grain and grain boundary is supposed to explain the various mechanical performances and corrosion resistance.
Evaluation of cavitation erosion resistance of copper alloy in different liquid media
Authors: Liu Haixia , Zhang Tao , Kang Can
Published: November 2017

To evaluate the influence of liquid property on cavitation erosion resistance of the copper alloy, an experimental investigation is performed with the ultrasonic vibratory apparatus. Liquid media of deionized water, tap water, and 3.5 wt.% NaCl solution are selected. The cumulative mass loss rate and microhardness are measured and surface morphology observed at different erosion time. The results show that the cumulative mass loss increases consistently with the erosion time, and the highest cumulative mass loss rate is witnessed in tap water. The erosion time at which the maximum cumulative mass loss rate is reached is the shortest with the 3.5 wt.% NaCl solution. Surface morphology testifies the rapid evolution of small cavitation erosion pits into large eroded area in the specimen surface submerged in the deionized water and tap water. In comparison, the specimen surface in the 3.5 wt.% NaCl solution is featured by insignificant cavitation erosion, and plastic deformation remains predominant for a long erosion time. The initiation and development of micro‐cracks are remarkable in tap water. In the 3.5 wt.% NaCl solution, the progression of cavitation erosion is mitigated relative to the other two cases, and cavitation erosion pits remain the predominant constituents of the erosion pattern as the erosion time increases. The hardening layer is found beneath the specimen surface, and the 3.5 wt.% NaCl solution is responsible for the thickest hardening layer. As cavitation erosion develops, the softening phenomenon is salient with consistent flaking off of surface layers.
Passivity and its breakdown on low temperature plasma carburized AISI 204Cu stainless steel in chloride‐containing solution
Authors: Rosalbino Francesco , Scavino Giorgio , Ubertalli Graziano
Published: November 2017

The passivity and passivity breakdown of low temperature plasma carburized AISI 204Cu stainless steel were studied in borate buffer solution (pH 8.4) in the absence and presence of 150 mM KCl, performing potentiodynamic polarization, potentiostatic transients, and electrochemical impedance spectroscopy (EIS) measurements complemented with scanning electron microscopy (SEM). In the absence of chloride ions, the surface treatment exercise a beneficial role in the passivating characteristics of AISI 204Cu. Plasma carburizing significantly modifies the electrochemical response of 204Cu steel resulting in a more stable passive film. In the presence of chloride ions, both the untreated and plasma carburized specimen experience localized corrosion (pitting). However, plasma carburizing increases the breakdown potential and the extent of passivation domain, indicating improved resistance to initiation of pitting corrosion. Furthermore, EIS measurements performed at the breakdown state evidenced higher Rct and lower depression angle values for the carburized specimen compared to the untreated alloy, confirming its better localized corrosion behavior. The high amount of interstitial carbon is believed to be responsible for the enhanced protective function of passive film which exerts an effective inhibiting action towards the localized corrosion process.
SLC34A2 regulates miR‐25‐Gsk3β signaling pathway to affect tumor progression in gastric cancer stem cell‐like cells
Authors: Zhang Lanfang , Guo Xiaohe , Zhang Lili , Yang Fang , Qin Lei , Zhang Dezhong , Qin Yongmei
Published: November 2017

A novel paradigm in tumor biology suggests that gastric cancer progression is driven by gastric cancer stem cell‐like cells (GCSCs), but molecular mechanisms regulating tumorigenic and self‐renewal potential of GCSCs are still unclear. Here, we aim to investigate biological function of SLC34A2 in regulating sphere formation and tumorigenicity (both are the hallmark of CSCs) of GCSCs and its underlying mechanisms. Our findings testified that CD44+ cells which were derived from fresh primary gastric cancer samples and cell lines displayed stem cell‐like features. Significantly, SLC34A2 is increased in CD44+ GCSCs compared with those in adherent counterpart from CD44+ GCSCs. On clinic, SLC34A2 is overexpressed in primary tumor tissues compared with adjacent counterparts. We showed that SLC34A2 regulated sphere formation and self‐renewal properties of CD44+ GCSCs in vitro and in vivo. Mechanistic investigations revealed that Gsk3β was the most strikingly up‐regulated gene in response to SLC34A2 knockdown in GCSCs and Wnt/β‐cantenin signaling was required for SLC34A2‐mediated sphere formation. Furthermore, SLC34A2 directly binds specific sites in the miR‐25 promoter region and that the promoter activity is decreased after the mutation of putative SLC34A2‐binding sites, indicating that SLC34A2 is required for the transcriptional induction of miR‐25. Meanwhile, luciferase assays showed that miR‐25 directly targeted Gsk3β in CD44+ GCSCs. Overall, our findings define a SLC34A2‐miR‐25‐Gsk3β pathway in the regulation of GCSCs features and gastric cancer progression, with potential therapeutic applications in blocking their progression.
Sequential product positioning in the presence of an asymmetric network externality intensity
Authors: Saito Ryoichi , Matsubayashi Nobuo
Published: November 2017

In this study, we analyze the sequential decisions on product positioning of two firms in the presence of network externalities. One commonly accepted phenomena in a market where a network externality arises is the first‐mover advantage, in which the first entrant into a market can earn a higher profit than later entrants. However, in some recent online services markets, we see that the second mover earns a higher profit than the first mover. This occurs because the second mover strengthens its variety of available functions and services markedly, thereby facilitating consumers' work and communication with its main product, which we call network externality intensity. Based on this observation, we analyze sequential positioning in Hotelling's framework by incorporating an asymmetric network externality intensity between firms. We show that unlike the results of previous related studies, both first‐ and second‐mover advantages can appear in the equilibrium depending on the relationship of the network externality intensity between firms; further, they do not change monotonically with the level of network externality intensity.
Nonlinear evolutionary systems driven by quasi‐hemivariational inequalities
Authors: Liu Zhenhai , Motreanu Dumitru , Zeng Shengda
Published: November 2017

This paper is devoted to the study of the differential systems in arbitrary Banach spaces that are obtained by mixing nonlinear evolutionary equations and generalized quasi‐hemivariational inequalities (EEQHVI). We start by showing that the solution set of the quasi‐hemivariational inequality associated to problem EEQHVI is nonempty, closed, and convex. Furthermore, we establish upper semicontinuity and measurability properties for this solution set. Then, based on them, we prove the existence of solutions for problem EEQHVI and the compactness of the set of corresponding trajectories of EEQHVI. These statements extend previous results in several directions, for instance, by dropping the boundedness requirement for the set of constraints and substantially relaxing monotonicity hypotheses.
Blow‐up analysis for a class of nonlinear reaction diffusion equations with Robin boundary conditions
Authors: Ding Juntang , Shen Xuhui
Published: November 2017

This paper is devoted to the study of the blow‐up phenomena of following nonlinear reaction diffusion equations with Robin boundary conditions:

urn:x-wiley:mma:media:mma4697:mma4697-math-0001

Here,
is a bounded convex domain with smooth boundary. With the aid of a differential inequality technique and maximum principles, we establish a blow‐up or non–blow‐up criterion under some appropriate assumptions on the functions f,g,ρ,k, and u0. Moreover, we dedicate an upper bound and a lower bound for the blow‐up time when blowup occurs.
Technical Note: Solving the “Chinese postman problem” for effective contour deformation
Authors: Wang Jingqian , Zhang Yongbin , Zhang Lifei , Dong Lei , Balter Peter A. , Court Laurence E. , Yang Jinzhong
Published: November 2017

Purpose

To develop a practical approach for accurate contour deformation when deformable image registration (DIR) is used for atlas‐based segmentation or contour propagation in image‐guided radiotherapy.

Methods

We developed a contour deformation approach based on 3D mesh operations. The 2D contours represented by a series of points in each slice were first converted to a 3D triangular mesh, which was deformed by the deformation vectors resulting from DIR. A set of parallel 2D planes then cut through the deformed 3D mesh, generating unordered points and line segments, to be reorganized into a set of 2D contour points. The reorganization problem was equivalent to solving the “Chinese postman problem” (CPP) by traversing a graph built from the unordered points with the least cost. Alternatively, deformation could be applied to a binary image converted from the original contours. The deformed binary image was then converted back into contours at the CT slice locations. We validated the mesh‐based contour deformation approach using lung and heart contours from 10 patients with thoracic cancer.

Results

DIR could change the 3D mesh considerably, complicating 2D contour representations after deformation. CPP could effectively reorganize the points in 2D planes regardless of how complicated the 2D contours were. Among the 10 patients, the Dice similarity coefficient between the mesh‐based contour and binary image‐based contour was 97.6% ± 0.3% for lung and 97.5% ± 0.7% for heart, and the Hausdoroff distance between them was 19.8 ± 5.1 mm for lung and 6.1 ± 2.2 mm for heart. Subjective evaluation showed that the mesh‐based approach could keep fine details, especially for the lung. The image‐based approach seemed to overprocess contours and suffered from image resolution limits.

Conclusion

We developed a practical approach for accurate contour deformation and demonstrated its effectiveness for both clinical and research applications.
Technical Note: Defining cyclotron‐based clinical scanning proton machines in a FLUKA Monte Carlo system
Authors: Fiorini Francesca , Schreuder Niek , Van den Heuvel Frank
Published: November 2017

Purpose

Cyclotron‐based pencil beam scanning (PBS) proton machines represent nowadays the majority and most affordable choice for proton therapy facilities, however, their representation in Monte Carlo (MC) codes is more complex than passively scattered proton system‐ or synchrotron‐based PBS machines. This is because degraders are used to decrease the energy from the cyclotron maximum energy to the desired energy, resulting in a unique spot size, divergence, and energy spread depending on the amount of degradation. This manuscript outlines a generalized methodology to characterize a cyclotron‐based PBS machine in a general‐purpose MC code. The code can then be used to generate clinically relevant plans starting from commercial TPS plans.

Methods

The described beam is produced at the Provision Proton Therapy Center (Knoxville, TN, USA) using a cyclotron‐based IBA Proteus Plus equipment. We characterized the Provision beam in the MC FLUKA using the experimental commissioning data. The code was then validated using experimental data in water phantoms for single pencil beams and larger irregular fields. Comparisons with RayStation TPS plans are also presented.

Results

Comparisons of experimental, simulated, and planned dose depositions in water plans show that same doses are calculated by both programs inside the target areas, while penumbrae differences are found at the field edges. These differences are lower for the MC, with a γ(3%–3 mm) index never below 95%.

Conclusions

Extensive explanations on how MC codes can be adapted to simulate cyclotron‐based scanning proton machines are given with the aim of using the MC as a TPS verification tool to check and improve clinical plans. For all the tested cases, we showed that dose differences with experimental data are lower for the MC than TPS, implying that the created FLUKA beam model is better able to describe the experimental beam.
RECORDS: improved Reporting of montE CarlO RaDiation transport Studies: Report of the AAPM Research Committee Task Group 268
Authors: Sechopoulos Ioannis , Rogers D. W. O. , Bazalova‐Carter Magdalena , Bolch Wesley E. , Heath Emily C. , McNitt‐Gray Michael F. , Sempau Josep , Williamson Jeffrey F.
Published: November 2017

Studies involving Monte Carlo simulations are common in both diagnostic and therapy medical physics research, as well as other fields of basic and applied science. As with all experimental studies, the conditions and parameters used for Monte Carlo simulations impact their scope, validity, limitations, and generalizability. Unfortunately, many published peer‐reviewed articles involving Monte Carlo simulations do not provide the level of detail needed for the reader to be able to properly assess the quality of the simulations. The American Association of Physicists in Medicine Task Group #268 developed guidelines to improve reporting of Monte Carlo studies in medical physics research. By following these guidelines, manuscripts submitted for peer‐review will include a level of relevant detail that will increase the transparency, the ability to reproduce results, and the overall scientific value of these studies. The guidelines include a checklist of the items that should be included in the Methods, Results, and Discussion sections of manuscripts submitted for peer‐review. These guidelines do not attempt to replace the journal reviewer, but rather to be a tool during the writing and review process. Given the varied nature of Monte Carlo studies, it is up to the authors and the reviewers to use this checklist appropriately, being conscious of how the different items apply to each particular scenario. It is envisioned that this list will be useful both for authors and for reviewers, to help ensure the adequate description of Monte Carlo studies in the medical physics literature.
Continuous Automated Model EvaluatiOn (CAMEO) complementing the critical assessment of structure prediction in CASP12
Authors: Haas Jürgen , Barbato Alessandro , Behringer Dario , Studer Gabriel , Roth Steven , Bertoni Martino , Mostaguir Khaled , Gumienny Rafal , Schwede Torsten
Published: November 2017

Every second year, the community experiment “Critical Assessment of Techniques for Structure Prediction” (CASP) is conducting an independent blind assessment of structure prediction methods, providing a framework for comparing the performance of different approaches and discussing the latest developments in the field. Yet, developers of automated computational modeling methods clearly benefit from more frequent evaluations based on larger sets of data. The “Continuous Automated Model EvaluatiOn (CAMEO)” platform complements the CASP experiment by conducting fully automated blind prediction assessments based on the weekly pre‐release of sequences of those structures, which are going to be published in the next release of the PDB Protein Data Bank. CAMEO publishes weekly benchmarking results based on models collected during a 4‐day prediction window, on average assessing ca. 100 targets during a time frame of 5 weeks. CAMEO benchmarking data is generated consistently for all participating methods at the same point in time, enabling developers to benchmark and cross‐validate their method's performance, and directly refer to the benchmarking results in publications. In order to facilitate server development and promote shorter release cycles, CAMEO sends weekly email with submission statistics and low performance warnings. Many participants of CASP have successfully employed CAMEO when preparing their methods for upcoming community experiments. CAMEO offers a variety of scores to allow benchmarking diverse aspects of structure prediction methods. By introducing new scoring schemes, CAMEO facilitates new development in areas of active research, for example, modeling quaternary structure, complexes, or ligand binding sites.
Model‐Based Reverse Translation Between Veterinary and Human Medicine: The One Health Initiative
Authors: Schneider Benjamin , Balbas‐Martinez Violeta , Jergens Albert E. , Troconiz Inaki F. , Allenspach Karin , Mochel Jonathan P.
Published: November 2017

There is growing concern about the limitations of rodent models with regard to recapitulation of human disease pathogenesis. Computational modeling of data from humans and animals sharing similar diseases provides an opportunity for parallel drug development in human and veterinary medicine. This “reverse translational” approach needs to be supported by continuing efforts to refine the in silico tools that allow extrapolation of results between species.
The Giant Elastocaloric Effect in a Cu–Zn–Al Shape‐Memory Alloy: a Calorimetric Study
Authors: Gràcia‐Condal Adrià , Stern‐Taulats Enric , Planes Antoni , Vives Eduard , Mañosa Lluís
Published: November 2017

We study the giant elastocaloric effect in a Cu–Zn–Al shape‐memory alloy by means of simultaneous calorimetry and dilatometry measurements under applied uniaxial compression which have been carried out with a bespoke experimental setup. The output data allow a unique quasidirect and indirect characterization of the thermal response that provides accurate ΔS and ΔT values. We report a large thermal response of |ΔS| = 22 J K kg−1, |ΔT| = 12.3 K, and RC = 325 K kg−1 driven by moderate uniaxial compression changes of 32.2 MPa, which is comparable with the performance of the best magnetocaloric materials. In view of the hysteresis effects, the thermal response is predicted to exhibit reversible values for |Δσ| = 32 MPa.
Identification, characterization and distribution of terpene indole alkaloids in ethanolic extracts of Catharanthus roseus using high‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry and the study of their geographical variation
Authors: Kumar Sunil , Bajpai Vikas , Singh Awantika , Kumar Brijesh
Published: November 2017

Rationale

Catharanthus roseus is a well‐known dicotyledonous medicinal plant containing diverse classes of bioactive terpene indole alkaloids (TIAs), in particular the anticancer agents vinblastine and vincristine. In view of the commercial importance of these compounds there is an urgent need to develop an accurate and reliable method for the screening of TIAs from C. roseus.

Methods

A method for the separation and characterization of these compounds was developed using high‐performance liquid chromatography coupled with positive electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (HPLC/ESI‐QTOF‐MS/MS). Chromatographic separation of TIAs was carried out using a Thermo Betasil C8 column (250 mm × 4.5 mm, 5 μm) at 25°C using 0.1% formic acid in water and acetonitrile.

Results

Diagnostic fragmentation pathways for vinpocetine, vindesine, catharanthine, vinblastine, vindoline and vincristine were established on the basis of their product ions. A total of 72 TIAs were detected of which 11 were unambiguously identified by comparison with their standards, and the remaining 61 were tentatively identified. The geographical distribution of the TIAs in ethanolic extracts of 30 samples of C. roseus collected from five states of India was studied using principal component analysis (PCA).

Conclusions

The developed analytical method together with diagnostic fragment patterns were used to rapidly and effectively identify targeted and untargeted TIAs in C. roseus. A PCA study of the results obtained was used to discriminate among the C. roseus samples.
Nanostructured Host Materials for Trapping Sulfur in Rechargeable Li–S Batteries: Structure Design and Interfacial Chemistry
Authors: Zhang Jun , Huang Hui , Bae Jiwoong , Chung Sheng‐Heng , Zhang Wenkui , Manthiram Arumugam , Yu Guihua
Published: November 2017

Lithium–sulfur (Li–S) batteries are considered as a promising candidate for next‐generation energy‐storage devices due to their high energy density, low cost, and ecofriendliness. However, the practical application of Li–S batteries faces challenges arising from the cathode, the electrolyte, and the anode, including the intrinsically low conductivity of sulfur and lithium sulfide (Li2S), the high solubility of polysulfides in the electrolytes commonly used, and the dendrite growth of metallic lithium anodes. In recent years, much effort has been made to improve the performance of Li–S batteries by modifying the cathode, host material, binder, electrolyte, membrane, anode, and cell configuration. Here, the focus is on the cathode aspect, and the design and surface modification of nanostructured host materials for sulfur and Li2S are investigated in detail.
Effect of Dry Heat Treatment With Xanthan Gum on Physicochemical Properties of Different Amylose Rice Starches
Authors: Su Jian , Chotineeranat Sunee , Laoka Bhakkhawat , Chatakanonda Pathama , Vanichsriratana Wirat , Sriroth Klanarong , Piyachomkwan Kuakoon
Published: November 2017

High amylose (HA), medium amylose (MA), low amylose (LA) (amylose content = 37.85, 27.55, and 9.98%, respectively) rice starches are modified by dry heat treatment (130 °C) with xanthan gum (X). The physicochemical properties of dry heated xanthan‐rice starch samples (modified sample: HAX‐130, MAX‐130, and LAX‐130) are investigated and compared with native rice starches (HA, MA, and LA) and two controls including dry heated rice starch samples (control I: HA‐130, MA‐130, and LA‐130); xanthan‐rice starch mixed samples (control II: HAX, MAX, and LAX). Granule swelling of dry heated xanthan‐rice starch samples is restricted, and upon complete gelatinization, their granules’ edge still maintained visible when observed by means of hot‐stage microscopy. Furthermore, morphological analysis of modified samples exhibited that xanthan gum, visualized by methylene blue staining, is anchored to swollen granules and not dispersed upon cooking, which suggested that some interactions between xanthan gum and starch molecules induced by dry heat treatment. A relatively lower breakdown viscosity and higher final viscosity are obtained for dry heated xanthan‐rice starch samples, which implied that granule rigidity of native rice starches is improved by dry heat treatment with xanthan gum. Rheological analysis also demonstrated that storage modulus of modified samples, in particular low amylose rice starch (G′ = 70.7 and 528.3 Pa, at 95 °C for LA and LAX‐130, respectively), are significantly improved. This also could be another evidence for proving the modification of native rice starches happened upon dry heat treatment with xanthan gum.
Acetylated Starch‐Based Nanoparticles: Synthesis, Characterization, and Studies of Interaction With Antioxidants
Authors: de Oliveira Natalia R. , Fornaciari Barbara , Mali Suzana , Carvalho Gizilene M.
Published: November 2017

Acetylated starch‐based (cassava and oxidized starch) nanoparticles are prepared by nanoprecipitation method using water as non‐solvent. Analyses of scanning electron microscopy (SEM) shows that nanoparticles (NPs) are obtained in spherical shape with average sizes between 500 and 900 nm. The crystallinity of the samples is determined by means of Fourier Transform Infrared Spectroscopy (FTIR) and wide‐angle X‐ray diffraction (WAXD), which demonstrated that the produced NPs has lower crystallinity than their respective acetates. The incorporation of antioxidants (gallic acid [GA] and butylated hydroxytoluene [BHT)]) into the NPs is also evaluated, where a 90% incorporation was obtained for BHT while the incorporation for GA is only 10%. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) are performed in order to investigate thermal stability and interaction of antioxidants (AOs) with NPs. The glass transition temperature (Tg) of the NPs incorporated with BHT and GA are higher than that of pure NPs, indicating that the presence of AOs restricted the mobility of starch acetate chains. Kinetic degradation parameters are obtained by Horowitz and Metzger method. The results show that the incorporation of BHT increases the activation energy value for NPs. The interaction between BHT and starch acetate protects the AO from degradation process, thus increasing the thermal stability of NPs.
Thermo‐mechanical response of concrete sandwich panels reinforced with glass fiber reinforced polymer bars
Authors: Schmitt Andreas , Carvelli Valter , Haffke Marcin M. , Pahn Matthias
Published: November 2017

The thermo‐mechanical behavior of sandwich panels was experimentally investigated. The panels featured two external concrete layers reinforced with glass fiber reinforced polymer rebars (GFRP) and an internal expanded polystyrene insulation layer. These are typical for low load bearing and thermally insulated panels in façade claddings. To assess the suitability of the internal GFRP reinforcement, the heating condition was such that rebars in one concrete layer were exposed to temperatures higher than the glass transition temperature of the resins. Such extreme condition allowed verifying the retention of the mechanical behavior, in terms of deformability and load‐carrying capacity, with bending tests of unheated and heated panels. As main outcome, the elevated temperature produced significant modification of the insulation layer, considerable reduction of global stiffness and load‐carrying capacity, while GFRP bars were not apparently modified.
The Complexity of Datafication: Putting Digital Traces in Context
Authors: Breiter Andreas , Hepp Andreas
Published: November 2017

This chapter deepens the discussion on the problem of contextualizing digital traces. First, digital traces are reflected as a phenomenon of media-related complexity more generally. Secondly, the example of data from learning management systems is taken to discuss possible strategies of how to put such automatically generated data into context by the use of qualitative methods that become triangulated. On such a basis, some conclusions are drawn about the future challenges of this kind of research. Overall, this chapter can only argue in an exemplary way, taking a specific and thus limited case of analysis. But such detailed discussion makes it possible to outline different options for future methodological developments in media and communication research.
Communicative Figurations of Expertization: DIY_MAKER and Multi-Player Online Gaming (MOG) as Cultures of Amateur Learning
Authors: Wolf Karsten D. , Wudarski Urszula
Published: November 2017

This chapter explores the question of whether a changing media environment in times of deep mediatization opens up informal expertise development for a new culture of learning. It builds upon a theory of autodidaxy and prior research on the role of media in processes of expertise acquisition. In two learning domains that are open to autodidactical learning (DIY_MAKER and multiplayer online gaming), data was collected in a multi-site study based on interviews, observations and netnographic analysis to reconstruct communicative figurations of expertise development and compare them across different learning domains. It can be shown that the learning domain’s media ensembles both share and differ in respect of their media usage. While mainstream media such as Facebook or YouTube are part of both ensembles, each learning domain’s very specific media types are described. In the analysis of constellations of actors, a ‘learning arena’ and a ‘commercialization arena’ can be identified in both domains. In DIY_MAKER, a central arena for informal learning is sharing/community, while in Multiplayer Online Gaming we find a meta-game arena. Both maps of media ensembles and constellations of actors are helpful in grasping the complexity of communicative practices and the role of media for expertise acquisition in the two learning domains. The research clearly shows the specific learning-domain characteristics of communicative figurations of learning.
The Communicative Construction of Space-Related Identities. Hamburg and Leipzig Between the Local and the Global
Authors: Robel Yvonne , Marszolek Inge
Published: November 2017

The chapter analyzes the communicative construction of space-related identities in mass communication from a historical point of view. Focusing on the 1950s, it deals with the medial construction of space-related identities in Hamburg and Leipzig. The main question is how the changing cities’ media ensembles relate to the transformations in urban collectivity building. Elaborating to what extent the local in Hamburg and Leipzig was constantly constructed by discourses on the global, we argue that the constructions of global images are very stable umbrella notions, even though the changing media ensembles and the worsening Cold War during the 1950s had some impact on gradually emerging new formations of space-related identities. Finally, the chapter discusses the idea of an entangled perspective, which could enrich the historical view of communicative figurations.